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arxiv-5601 | 0811.4773 | Two-way source coding with a helper | <|reference_start|>Two-way source coding with a helper: Consider the two-way rate-distortion problem in which a helper sends a common limited-rate message to both users based on side information at its disposal. We characterize the region of achievable rates and distortions where a Markov form (Helper)-(User 1)-(User 2) holds. The main insight of the result is that in order to achieve the optimal rate, the helper may use a binning scheme, as in Wyner-Ziv, where the side information at the decoder is the "further" user, namely, User 2. We derive these regions explicitly for the Gaussian sources with square error distortion, analyze a trade-off between the rate from the helper and the rate from the source, and examine a special case where the helper has the freedom to send different messages, at different rates, to the encoder and the decoder.<|reference_end|> | arxiv | @article{permuter2008two-way,
title={Two-way source coding with a helper},
author={Haim Permuter, Yossi Steinberg and Tsachy Weissman},
journal={arXiv preprint arXiv:0811.4773},
year={2008},
archivePrefix={arXiv},
eprint={0811.4773},
primaryClass={cs.IT math.IT}
} | permuter2008two-way |
arxiv-5602 | 0812.0038 | Omnidirectional Relay in Wireless Networks | <|reference_start|>Omnidirectional Relay in Wireless Networks: For wireless networks with multiple sources, an omnidirectional relay scheme is developed, where each node can simultaneously relay different messages in different directions. This is accomplished by the decode-and-forward relay strategy, with each relay binning the multiple messages to be transmitted, in the same spirit of network coding. Specially for the all-source all-cast problem, where each node is an independent source to be transmitted to all the other nodes, this scheme completely eliminates interference in the whole network, and the signal transmitted by any node can be used by any other node. For networks with some kind of symmetry, assuming no beamforming is to be performed, this omnidirectional relay scheme is capable of achieving the maximum achievable rate.<|reference_end|> | arxiv | @article{xie2008omnidirectional,
title={Omnidirectional Relay in Wireless Networks},
author={Liang-Liang Xie},
journal={arXiv preprint arXiv:0812.0038},
year={2008},
archivePrefix={arXiv},
eprint={0812.0038},
primaryClass={cs.IT math.IT}
} | xie2008omnidirectional |
arxiv-5603 | 0812.0067 | Stable normal forms for polynomial system solving | <|reference_start|>Stable normal forms for polynomial system solving: This paper describes and analyzes a method for computing border bases of a zero-dimensional ideal $I$. The criterion used in the computation involves specific commutation polynomials and leads to an algorithm and an implementation extending the one provided in [MT'05]. This general border basis algorithm weakens the monomial ordering requirement for \grob bases computations. It is up to date the most general setting for representing quotient algebras, embedding into a single formalism Gr\"obner bases, Macaulay bases and new representation that do not fit into the previous categories. With this formalism we show how the syzygies of the border basis are generated by commutation relations. We also show that our construction of normal form is stable under small perturbations of the ideal, if the number of solutions remains constant. This new feature for a symbolic algorithm has a huge impact on the practical efficiency as it is illustrated by the experiments on classical benchmark polynomial systems, at the end of the paper.<|reference_end|> | arxiv | @article{mourrain2008stable,
title={Stable normal forms for polynomial system solving},
author={Bernard Mourrain (INRIA Sophia Antipolis), Philippe Tr'ebuchet (LIP6)},
journal={Theoretical Computer Science 409, 2 (2008) 229-240},
year={2008},
doi={10.1016/j.tcs.2008.09.004},
archivePrefix={arXiv},
eprint={0812.0067},
primaryClass={cs.SC}
} | mourrain2008stable |
arxiv-5604 | 0812.0070 | An Integrated Software-based Solution for Modular and Self-independent Networked Robot | <|reference_start|>An Integrated Software-based Solution for Modular and Self-independent Networked Robot: An integrated software-based solution for a modular and self-independent networked robot is introduced. The wirelessly operatable robot has been developed mainly for autonomous monitoring works with full control over web. The integrated software solution covers three components : a) the digital signal processing unit for data retrieval and monitoring system; b) the externally executable codes for control system; and c) the web programming for interfacing the end-users with the robot. It is argued that this integrated software-based approach is crucial to realize a flexible, modular and low development cost mobile monitoring apparatus.<|reference_end|> | arxiv | @article{firmansyah2008an,
title={An Integrated Software-based Solution for Modular and Self-independent
Networked Robot},
author={I. Firmansyah, Z. Akbar, B. Hermanto and L.T. Handoko},
journal={arXiv preprint arXiv:0812.0070},
year={2008},
doi={10.1109/ICARCV.2008.4795695},
number={FISIKALIPI-08078},
archivePrefix={arXiv},
eprint={0812.0070},
primaryClass={cs.RO}
} | firmansyah2008an |
arxiv-5605 | 0812.0088 | Moment matrices, trace matrices and the radical of ideals | <|reference_start|>Moment matrices, trace matrices and the radical of ideals: Let $f_1,...,f_s \in \mathbb{K}[x_1,...,x_m]$ be a system of polynomials generating a zero-dimensional ideal $\I$, where $\mathbb{K}$ is an arbitrary algebraically closed field. Assume that the factor algebra $\A=\mathbb{K}[x_1,...,x_m]/\I$ is Gorenstein and that we have a bound $\delta>0$ such that a basis for $\A$ can be computed from multiples of $f_1,...,f_s$ of degrees at most $\delta$. We propose a method using Sylvester or Macaulay type resultant matrices of $f_1,...,f_s$ and $J$, where $J$ is a polynomial of degree $\delta$ generalizing the Jacobian, to compute moment matrices, and in particular matrices of traces for $\A$. These matrices of traces in turn allow us to compute a system of multiplication matrices $\{M_{x_i}|i=1,...,m\}$ of the radical $\sqrt{\I}$, following the approach in the previous work by Janovitz-Freireich, R\'{o}nyai and Sz\'ant\'o. Additionally, we give bounds for $\delta$ for the case when $\I$ has finitely many projective roots in $\mathbb{P}^m_\CC$.<|reference_end|> | arxiv | @article{janovitz-freireich2008moment,
title={Moment matrices, trace matrices and the radical of ideals},
author={Itnuit Janovitz-Freireich, Agnes Szanto, Bernard Mourrain (INRIA
Sophia Antipolis), Lajos Ronyai},
journal={nternational Conference on Symbolic and Algebraic Computation
(2008) 125-132},
year={2008},
archivePrefix={arXiv},
eprint={0812.0088},
primaryClass={cs.SC}
} | janovitz-freireich2008moment |
arxiv-5606 | 0812.0146 | Lower Bounds on Performance of Metric Tree Indexing Schemes for Exact Similarity Search in High Dimensions | <|reference_start|>Lower Bounds on Performance of Metric Tree Indexing Schemes for Exact Similarity Search in High Dimensions: Within a mathematically rigorous model, we analyse the curse of dimensionality for deterministic exact similarity search in the context of popular indexing schemes: metric trees. The datasets $X$ are sampled randomly from a domain $\Omega$, equipped with a distance, $\rho$, and an underlying probability distribution, $\mu$. While performing an asymptotic analysis, we send the intrinsic dimension $d$ of $\Omega$ to infinity, and assume that the size of a dataset, $n$, grows superpolynomially yet subexponentially in $d$. Exact similarity search refers to finding the nearest neighbour in the dataset $X$ to a query point $\omega\in\Omega$, where the query points are subject to the same probability distribution $\mu$ as datapoints. Let $\mathscr F$ denote a class of all 1-Lipschitz functions on $\Omega$ that can be used as decision functions in constructing a hierarchical metric tree indexing scheme. Suppose the VC dimension of the class of all sets $\{\omega\colon f(\omega)\geq a\}$, $a\in\R$ is $o(n^{1/4}/\log^2n)$. (In view of a 1995 result of Goldberg and Jerrum, even a stronger complexity assumption $d^{O(1)}$ is reasonable.) We deduce the $\Omega(n^{1/4})$ lower bound on the expected average case performance of hierarchical metric-tree based indexing schemes for exact similarity search in $(\Omega,X)$. In paricular, this bound is superpolynomial in $d$.<|reference_end|> | arxiv | @article{pestov2008lower,
title={Lower Bounds on Performance of Metric Tree Indexing Schemes for Exact
Similarity Search in High Dimensions},
author={Vladimir Pestov},
journal={Algorithmica 66 (2013), 310-328},
year={2008},
archivePrefix={arXiv},
eprint={0812.0146},
primaryClass={cs.DS}
} | pestov2008lower |
arxiv-5607 | 0812.0192 | A Simple Performance Analysis of a Core Node in an Optical Burst Switched Network | <|reference_start|>A Simple Performance Analysis of a Core Node in an Optical Burst Switched Network: This paper has been withdrawn<|reference_end|> | arxiv | @article{morsy2008a,
title={A Simple Performance Analysis of a Core Node in an Optical Burst
Switched Network},
author={Mohamed H. S. Morsy, Mohammad Y. S. Sowailem and Hossam M. H. Shalaby},
journal={arXiv preprint arXiv:0812.0192},
year={2008},
archivePrefix={arXiv},
eprint={0812.0192},
primaryClass={cs.NI cs.PF}
} | morsy2008a |
arxiv-5608 | 0812.0193 | Contention Resolution in Optical Burst Switched Networks using Spectral- Amplitude-Coding Optical Code Division Multiple Access | <|reference_start|>Contention Resolution in Optical Burst Switched Networks using Spectral- Amplitude-Coding Optical Code Division Multiple Access: This paper has been withdrawn by the authors.<|reference_end|> | arxiv | @article{sowailem2008contention,
title={Contention Resolution in Optical Burst Switched Networks using Spectral-
Amplitude-Coding Optical Code Division Multiple Access},
author={Mohamed Y. S. Sowailem, Mohamed H. S. Morsy and Hossam M. H. Shalaby},
journal={arXiv preprint arXiv:0812.0193},
year={2008},
archivePrefix={arXiv},
eprint={0812.0193},
primaryClass={cs.NI}
} | sowailem2008contention |
arxiv-5609 | 0812.0197 | Zigzag Persistence | <|reference_start|>Zigzag Persistence: We describe a new methodology for studying persistence of topological features across a family of spaces or point-cloud data sets, called zigzag persistence. Building on classical results about quiver representations, zigzag persistence generalises the highly successful theory of persistent homology and addresses several situations which are not covered by that theory. In this paper we develop theoretical and algorithmic foundations with a view towards applications in topological statistics.<|reference_end|> | arxiv | @article{carlsson2008zigzag,
title={Zigzag Persistence},
author={Gunnar Carlsson, Vin de Silva},
journal={arXiv preprint arXiv:0812.0197},
year={2008},
archivePrefix={arXiv},
eprint={0812.0197},
primaryClass={cs.CG}
} | carlsson2008zigzag |
arxiv-5610 | 0812.0198 | Convergence to Equilibrium in Local Interaction Games and Ising Models | <|reference_start|>Convergence to Equilibrium in Local Interaction Games and Ising Models: Coordination games describe social or economic interactions in which the adoption of a common strategy has a higher payoff. They are classically used to model the spread of conventions, behaviors, and technologies in societies. Here we consider a two-strategies coordination game played asynchronously between the nodes of a network. Agents behave according to a noisy best-response dynamics. It is known that noise removes the degeneracy among equilibria: In the long run, the ``risk-dominant'' behavior spreads throughout the network. Here we consider the problem of computing the typical time scale for the spread of this behavior. In particular, we study its dependence on the network structure and derive a dichotomy between highly-connected, non-local graphs that show slow convergence, and poorly connected, low dimensional graphs that show fast convergence.<|reference_end|> | arxiv | @article{montanari2008convergence,
title={Convergence to Equilibrium in Local Interaction Games and Ising Models},
author={Andrea Montanari and Amin Saberi},
journal={arXiv preprint arXiv:0812.0198},
year={2008},
archivePrefix={arXiv},
eprint={0812.0198},
primaryClass={cs.GT}
} | montanari2008convergence |
arxiv-5611 | 0812.0209 | Optimal Tracking of Distributed Heavy Hitters and Quantiles | <|reference_start|>Optimal Tracking of Distributed Heavy Hitters and Quantiles: We consider the the problem of tracking heavy hitters and quantiles in the distributed streaming model. The heavy hitters and quantiles are two important statistics for characterizing a data distribution. Let $A$ be a multiset of elements, drawn from the universe $U=\{1,...,u\}$. For a given $0 \le \phi \le 1$, the $\phi$-heavy hitters are those elements of $A$ whose frequency in $A$ is at least $\phi |A|$; the $\phi$-quantile of $A$ is an element $x$ of $U$ such that at most $\phi|A|$ elements of $A$ are smaller than $A$ and at most $(1-\phi)|A|$ elements of $A$ are greater than $x$. Suppose the elements of $A$ are received at $k$ remote {\em sites} over time, and each of the sites has a two-way communication channel to a designated {\em coordinator}, whose goal is to track the set of $\phi$-heavy hitters and the $\phi$-quantile of $A$ approximately at all times with minimum communication. We give tracking algorithms with worst-case communication cost $O(k/\eps \cdot \log n)$ for both problems, where $n$ is the total number of items in $A$, and $\eps$ is the approximation error. This substantially improves upon the previous known algorithms. We also give matching lower bounds on the communication costs for both problems, showing that our algorithms are optimal. We also consider a more general version of the problem where we simultaneously track the $\phi$-quantiles for all $0 \le \phi \le 1$.<|reference_end|> | arxiv | @article{yi2008optimal,
title={Optimal Tracking of Distributed Heavy Hitters and Quantiles},
author={Ke Yi, Qin Zhang},
journal={arXiv preprint arXiv:0812.0209},
year={2008},
archivePrefix={arXiv},
eprint={0812.0209},
primaryClass={cs.DS}
} | yi2008optimal |
arxiv-5612 | 0812.0262 | An evaluation of Bradfordizing effects | <|reference_start|>An evaluation of Bradfordizing effects: The purpose of this paper is to apply and evaluate the bibliometric method Bradfordizing for information retrieval (IR) experiments. Bradfordizing is used for generating core document sets for subject-specific questions and to reorder result sets from distributed searches. The method will be applied and tested in a controlled scenario of scientific literature databases from social and political sciences, economics, psychology and medical science (SOLIS, SoLit, USB Koeln Opac, CSA Sociological Abstracts, World Affairs Online, Psyndex and Medline) and 164 standardized topics. An evaluation of the method and its effects is carried out in two laboratory-based information retrieval experiments (CLEF and KoMoHe) using a controlled document corpus and human relevance assessments. The results show that Bradfordizing is a very robust method for re-ranking the main document types (journal articles and monographs) in today's digital libraries (DL). The IR tests show that relevance distributions after re-ranking improve at a significant level if articles in the core are compared with articles in the succeeding zones. The items in the core are significantly more often assessed as relevant, than items in zone 2 (z2) or zone 3 (z3). The improvements between the zones are statistically significant based on the Wilcoxon signed-rank test and the paired T-Test.<|reference_end|> | arxiv | @article{mayr2008an,
title={An evaluation of Bradfordizing effects},
author={Philipp Mayr},
journal={arXiv preprint arXiv:0812.0262},
year={2008},
archivePrefix={arXiv},
eprint={0812.0262},
primaryClass={cs.DL}
} | mayr2008an |
arxiv-5613 | 0812.0283 | Dichotomy Results for Fixed Point Counting in Boolean Dynamical Systems | <|reference_start|>Dichotomy Results for Fixed Point Counting in Boolean Dynamical Systems: We present dichotomy theorems regarding the computational complexity of counting fixed points in boolean (discrete) dynamical systems, i.e., finite discrete dynamical systems over the domain {0,1}. For a class F of boolean functions and a class G of graphs, an (F,G)-system is a boolean dynamical system with local transitions functions lying in F and graphs in G. We show that, if local transition functions are given by lookup tables, then the following complexity classification holds: Let F be a class of boolean functions closed under superposition and let G be a graph class closed under taking minors. If F contains all min-functions, all max-functions, or all self-dual and monotone functions, and G contains all planar graphs, then it is #P-complete to compute the number of fixed points in an (F,G)-system; otherwise it is computable in polynomial time. We also prove a dichotomy theorem for the case that local transition functions are given by formulas (over logical bases). This theorem has a significantly more complicated structure than the theorem for lookup tables. A corresponding theorem for boolean circuits coincides with the theorem for formulas.<|reference_end|> | arxiv | @article{homan2008dichotomy,
title={Dichotomy Results for Fixed Point Counting in Boolean Dynamical Systems},
author={Christopher M. Homan and Sven Kosub},
journal={arXiv preprint arXiv:0812.0283},
year={2008},
number={revised version of TR No. TUM-I0706, Institut fuer Informatik, TU
Muenchen},
archivePrefix={arXiv},
eprint={0812.0283},
primaryClass={cs.CC cond-mat.dis-nn cs.DM nlin.AO nlin.CG}
} | homan2008dichotomy |
arxiv-5614 | 0812.0319 | Secrecy Capacity of a Class of Broadcast Channels with an Eavesdropper | <|reference_start|>Secrecy Capacity of a Class of Broadcast Channels with an Eavesdropper: We study the security of communication between a single transmitter and multiple receivers in a broadcast channel in the presence of an eavesdropper. We consider several special classes of channels. As the first model, we consider the degraded multi-receiver wiretap channel where the legitimate receivers exhibit a degradedness order while the eavesdropper is more noisy with respect to all legitimate receivers. We establish the secrecy capacity region of this channel model. Secondly, we consider the parallel multi-receiver wiretap channel with a less noisiness order in each sub-channel, where this order is not necessarily the same for all sub-channels. We establish the common message secrecy capacity and sum secrecy capacity of this channel. Thirdly, we study a special class of degraded parallel multi-receiver wiretap channels and provide a stronger result. In particular, we study the case with two sub-channels two users and one eavesdropper, where there is a degradedness order in each sub-channel such that in the first (resp. second) sub-channel the second (resp. first) receiver is degraded with respect to the first (resp. second) receiver, while the eavesdropper is degraded with respect to both legitimate receivers in both sub-channels. We determine the secrecy capacity region of this channel. Finally, we focus on a variant of this previous channel model where the transmitter can use only one of the sub-channels at any time. We characterize the secrecy capacity region of this channel as well.<|reference_end|> | arxiv | @article{ekrem2008secrecy,
title={Secrecy Capacity of a Class of Broadcast Channels with an Eavesdropper},
author={Ersen Ekrem and Sennur Ulukus},
journal={arXiv preprint arXiv:0812.0319},
year={2008},
archivePrefix={arXiv},
eprint={0812.0319},
primaryClass={cs.IT math.IT}
} | ekrem2008secrecy |
arxiv-5615 | 0812.0320 | Stackelberg Network Pricing is Hard to Approximate | <|reference_start|>Stackelberg Network Pricing is Hard to Approximate: In the Stackelberg Network Pricing problem, one has to assign tariffs to a certain subset of the arcs of a given transportation network. The aim is to maximize the amount paid by the user of the network, knowing that the user will take a shortest st-path once the tariffs are fixed. Roch, Savard, and Marcotte (Networks, Vol. 46(1), 57-67, 2005) proved that this problem is NP-hard, and gave an O(log m)-approximation algorithm, where m denote the number of arcs to be priced. In this note, we show that the problem is also APX-hard.<|reference_end|> | arxiv | @article{joret2008stackelberg,
title={Stackelberg Network Pricing is Hard to Approximate},
author={Gwena"el Joret},
journal={Networks, vol. 57, no. 2, pp. 117--120, 2011},
year={2008},
doi={10.1002/net.20391},
archivePrefix={arXiv},
eprint={0812.0320},
primaryClass={cs.DS cs.GT}
} | joret2008stackelberg |
arxiv-5616 | 0812.0329 | Block-Sparsity: Coherence and Efficient Recovery | <|reference_start|>Block-Sparsity: Coherence and Efficient Recovery: We consider compressed sensing of block-sparse signals, i.e., sparse signals that have nonzero coefficients occuring in clusters. Based on an uncertainty relation for block-sparse signals, we define a block-coherence measure and we show that a block-version of the orthogonal matching pursuit algorithm recovers block k-sparse signals in no more than k steps if the block-coherence is sufficiently small. The same condition on block-sparsity is shown to guarantee successful recovery through a mixed l2/l1 optimization approach. The significance of the results lies in the fact that making explicit use of block-sparsity can yield better reconstruction properties than treating the signal as being sparse in the conventional sense thereby ignoring the additional structure in the problem.<|reference_end|> | arxiv | @article{eldar2008block-sparsity:,
title={Block-Sparsity: Coherence and Efficient Recovery},
author={Yonina C. Eldar and Helmut Bolcskei},
journal={arXiv preprint arXiv:0812.0329},
year={2008},
archivePrefix={arXiv},
eprint={0812.0329},
primaryClass={cs.IT math.IT}
} | eldar2008block-sparsity: |
arxiv-5617 | 0812.0340 | A Matlab Implementation of a Flat Norm Motivated Polygonal Edge Matching Method using a Decomposition of Boundary into Four 1-Dimensional Currents | <|reference_start|>A Matlab Implementation of a Flat Norm Motivated Polygonal Edge Matching Method using a Decomposition of Boundary into Four 1-Dimensional Currents: We describe and provide code and examples for a polygonal edge matching method.<|reference_end|> | arxiv | @article{morgan2008a,
title={A Matlab Implementation of a Flat Norm Motivated Polygonal Edge Matching
Method using a Decomposition of Boundary into Four 1-Dimensional Currents},
author={Simon P. Morgan, Wotao Yin, Kevin R. Vixie},
journal={arXiv preprint arXiv:0812.0340},
year={2008},
archivePrefix={arXiv},
eprint={0812.0340},
primaryClass={cs.CV cs.CG}
} | morgan2008a |
arxiv-5618 | 0812.0372 | Non-degenerate colorings in the Brook's Theorem | <|reference_start|>Non-degenerate colorings in the Brook's Theorem: Let $c\geq 2$ and $p\geq c$ be two integers. We will call a proper coloring of the graph $G$ a \textit{$(c,p)$-nondegenerate}, if for any vertex of $G$ with degree at least $p$ there are at least $c$ vertices of different colors adjacent to it. In our work we prove the following result, which generalizes Brook's Theorem. Let $D\geq 3$ and $G$ be a graph without cliques on $D+1$ vertices and the degree of any vertex in this graph is not greater than $D$. Then for every integer $c\geq 2$ there is a proper $(c,p)$-nondegenerate vertex $D$-coloring of $G$, where $p=(c^3+8c^2+19c+6)(c+1).$ During the primary proof, some interesting corollaries are derived.<|reference_end|> | arxiv | @article{gravin2008non-degenerate,
title={Non-degenerate colorings in the Brook's Theorem},
author={Nikolay Gravin},
journal={Diskretnaya Matematika, 2009 N4 pp. 105-128},
year={2008},
doi={10.1515/DMA.2009.036},
number={MR2641023},
archivePrefix={arXiv},
eprint={0812.0372},
primaryClass={math.CO cs.DM}
} | gravin2008non-degenerate |
arxiv-5619 | 0812.0382 | k-means requires exponentially many iterations even in the plane | <|reference_start|>k-means requires exponentially many iterations even in the plane: The k-means algorithm is a well-known method for partitioning n points that lie in the d-dimensional space into k clusters. Its main features are simplicity and speed in practice. Theoretically, however, the best known upper bound on its running time (i.e. O(n^{kd})) can be exponential in the number of points. Recently, Arthur and Vassilvitskii [3] showed a super-polynomial worst-case analysis, improving the best known lower bound from \Omega(n) to 2^{\Omega(\sqrt{n})} with a construction in d=\Omega(\sqrt{n}) dimensions. In [3] they also conjectured the existence of superpolynomial lower bounds for any d >= 2. Our contribution is twofold: we prove this conjecture and we improve the lower bound, by presenting a simple construction in the plane that leads to the exponential lower bound 2^{\Omega(n)}.<|reference_end|> | arxiv | @article{vattani2008k-means,
title={k-means requires exponentially many iterations even in the plane},
author={Andrea Vattani},
journal={arXiv preprint arXiv:0812.0382},
year={2008},
archivePrefix={arXiv},
eprint={0812.0382},
primaryClass={cs.CG cs.DS cs.LG}
} | vattani2008k-means |
arxiv-5620 | 0812.0387 | Delaunay Triangulations in Linear Time? (Part I) | <|reference_start|>Delaunay Triangulations in Linear Time? (Part I): We present a new and simple randomized algorithm for constructing the Delaunay triangulation using nearest neighbor graphs for point location. Under suitable assumptions, it runs in linear expected time for points in the plane with polynomially bounded spread, i.e., if the ratio between the largest and smallest pointwise distance is polynomially bounded. This also holds for point sets with bounded spread in higher dimensions as long as the expected complexity of the Delaunay triangulation of a sample of the points is linear in the sample size.<|reference_end|> | arxiv | @article{buchin2008delaunay,
title={Delaunay Triangulations in Linear Time? (Part I)},
author={Kevin Buchin},
journal={arXiv preprint arXiv:0812.0387},
year={2008},
archivePrefix={arXiv},
eprint={0812.0387},
primaryClass={cs.CG cs.DS}
} | buchin2008delaunay |
arxiv-5621 | 0812.0389 | Approximation Algorithms for Bregman Co-clustering and Tensor Clustering | <|reference_start|>Approximation Algorithms for Bregman Co-clustering and Tensor Clustering: In the past few years powerful generalizations to the Euclidean k-means problem have been made, such as Bregman clustering [7], co-clustering (i.e., simultaneous clustering of rows and columns of an input matrix) [9,18], and tensor clustering [8,34]. Like k-means, these more general problems also suffer from the NP-hardness of the associated optimization. Researchers have developed approximation algorithms of varying degrees of sophistication for k-means, k-medians, and more recently also for Bregman clustering [2]. However, there seem to be no approximation algorithms for Bregman co- and tensor clustering. In this paper we derive the first (to our knowledge) guaranteed methods for these increasingly important clustering settings. Going beyond Bregman divergences, we also prove an approximation factor for tensor clustering with arbitrary separable metrics. Through extensive experiments we evaluate the characteristics of our method, and show that it also has practical impact.<|reference_end|> | arxiv | @article{jegelka2008approximation,
title={Approximation Algorithms for Bregman Co-clustering and Tensor Clustering},
author={Stefanie Jegelka, Suvrit Sra, Arindam Banerjee},
journal={short version in ALT 2009},
year={2008},
archivePrefix={arXiv},
eprint={0812.0389},
primaryClass={cs.DS cs.LG}
} | jegelka2008approximation |
arxiv-5622 | 0812.0438 | An Introduction to Knowledge Management | <|reference_start|>An Introduction to Knowledge Management: Knowledge has been lately recognized as one of the most important assets of organizations. Managing knowledge has grown to be imperative for the success of a company. This paper presents an overview of Knowledge Management and various aspects of secure knowledge management. A case study of knowledge management activities at Tata Steel is also discussed<|reference_end|> | arxiv | @article{thampi2008an,
title={An Introduction to Knowledge Management},
author={Sabu M. Thampi},
journal={arXiv preprint arXiv:0812.0438},
year={2008},
archivePrefix={arXiv},
eprint={0812.0438},
primaryClass={cs.DB cs.CR}
} | thampi2008an |
arxiv-5623 | 0812.0486 | On the computational complexity of solving stochastic mean-payoff games | <|reference_start|>On the computational complexity of solving stochastic mean-payoff games: We consider some well-known families of two-player, zero-sum, perfect information games that can be viewed as special cases of Shapley's stochastic games. We show that the following tasks are polynomial time equivalent: - Solving simple stochastic games. - Solving stochastic mean-payoff games with rewards and probabilities given in unary. - Solving stochastic mean-payoff games with rewards and probabilities given in binary.<|reference_end|> | arxiv | @article{gurvich2008on,
title={On the computational complexity of solving stochastic mean-payoff games},
author={Vladimir Gurvich and Peter Bro Miltersen},
journal={arXiv preprint arXiv:0812.0486},
year={2008},
archivePrefix={arXiv},
eprint={0812.0486},
primaryClass={cs.GT}
} | gurvich2008on |
arxiv-5624 | 0812.0492 | Trembling hand perfection is NP-hard | <|reference_start|>Trembling hand perfection is NP-hard: It is NP-hard to decide if a given pure-strategy Nash equilibrium of a given three-player game in strategic form with integer payoffs is trembling hand perfect.<|reference_end|> | arxiv | @article{miltersen2008trembling,
title={Trembling hand perfection is NP-hard},
author={Peter Bro Miltersen},
journal={arXiv preprint arXiv:0812.0492},
year={2008},
archivePrefix={arXiv},
eprint={0812.0492},
primaryClass={cs.GT}
} | miltersen2008trembling |
arxiv-5625 | 0812.0515 | A Relaying Incentive Scheme in Multihop Cellular Networks Based on Coalitional Game with Externalities | <|reference_start|>A Relaying Incentive Scheme in Multihop Cellular Networks Based on Coalitional Game with Externalities: Cooperative multihop communication can greatly increase network throughput, yet packet forwarding for other nodes involves opportunity and energy cost for relays. Thus one of the pre-requisite problems in the successful implementation of multihop transmission is how to foster cooperation among selfish nodes. Existing researches mainly adopt monetary stimulating. In this manuscript, we propose instead a simple and self-enforcing forwarding incentive scheme free of indirect monetary remunerating for asymmetric (uplink multihop, downlink single-hop) cellar network based on coalitional game theory, which comprises double compensation, namely, Inter- BEA, global stimulating policy allotting resources among relaying coalitions according to group size, and Intra-BEA, local compensating and allocating rule within coalitions. Firstly, given the global allotting policy, we introduce a fair allocation estimating approach which includes remunerating for relaying cost using Myerson value for partition function game, to enlighten the design of local allocating rules. Secondly, given the inter- and intra-BEA relay fostering approach, we check stability of coalition structures in terms of internal and external stability as well as inductive core. Theoretic analysis and numerical simulation show that our measure can provide communication opportunities for outer ring nodes and enlarge system coverage, while at the same time provide enough motivation with respect to resource allocation and energy saving for nodes in inner and middle ring to relay for own profits.<|reference_end|> | arxiv | @article{li2008a,
title={A Relaying Incentive Scheme in Multihop Cellular Networks Based on
Coalitional Game with Externalities},
author={Cuilian Li (1 and 2), Zhen Yang (1), Feng Tian (1) ((1) Nanjing
University of Posts & Telecommunications, (2) Zhejiang Wanli University)},
journal={arXiv preprint arXiv:0812.0515},
year={2008},
archivePrefix={arXiv},
eprint={0812.0515},
primaryClass={cs.GT}
} | li2008a |
arxiv-5626 | 0812.0564 | Provenance Traces | <|reference_start|>Provenance Traces: Provenance is information about the origin, derivation, ownership, or history of an object. It has recently been studied extensively in scientific databases and other settings due to its importance in helping scientists judge data validity, quality and integrity. However, most models of provenance have been stated as ad hoc definitions motivated by informal concepts such as "comes from", "influences", "produces", or "depends on". These models lack clear formalizations describing in what sense the definitions capture these intuitive concepts. This makes it difficult to compare approaches, evaluate their effectiveness, or argue about their validity. We introduce provenance traces, a general form of provenance for the nested relational calculus (NRC), a core database query language. Provenance traces can be thought of as concrete data structures representing the operational semantics derivation of a computation; they are related to the traces that have been used in self-adjusting computation, but differ in important respects. We define a tracing operational semantics for NRC queries that produces both an ordinary result and a trace of the execution. We show that three pre-existing forms of provenance for the NRC can be extracted from provenance traces. Moreover, traces satisfy two semantic guarantees: consistency, meaning that the traces describe what actually happened during execution, and fidelity, meaning that the traces "explain" how the expression would behave if the input were changed. These guarantees are much stronger than those contemplated for previous approaches to provenance; thus, provenance traces provide a general semantic foundation for comparing and unifying models of provenance in databases.<|reference_end|> | arxiv | @article{cheney2008provenance,
title={Provenance Traces},
author={James Cheney, Umut Acar, Amal Ahmed},
journal={arXiv preprint arXiv:0812.0564},
year={2008},
archivePrefix={arXiv},
eprint={0812.0564},
primaryClass={cs.PL cs.DB}
} | cheney2008provenance |
arxiv-5627 | 0812.0581 | Pushing BitTorrent Locality to the Limit | <|reference_start|>Pushing BitTorrent Locality to the Limit: Peer-to-peer (P2P) locality has recently raised a lot of interest in the community. Indeed, whereas P2P content distribution enables financial savings for the content providers, it dramatically increases the traffic on inter-ISP links. To solve this issue, the idea to keep a fraction of the P2P traffic local to each ISP was introduced a few years ago. Since then, P2P solutions exploiting locality have been introduced. However, several fundamental issues on locality still need to be explored. In particular, how far can we push locality, and what is, at the scale of the Internet, the reduction of traffic that can be achieved with locality? In this paper, we perform extensive experiments on a controlled environment with up to 10 000 BitTorrent clients to evaluate the impact of high locality on inter-ISP links traffic and peers download completion time. We introduce two simple mechanisms that make high locality possible in challenging scenarios and we show that we save up to several orders of magnitude inter-ISP traffic compared to traditional locality without adversely impacting peers download completion time. In addition, we crawled 214 443 torrents representing 6 113 224 unique peers spread among 9 605 ASes. We show that whereas the torrents we crawled generated 11.6 petabytes of inter-ISP traffic, our locality policy implemented for all torrents would have reduced the global inter-ISP traffic by 40%.<|reference_end|> | arxiv | @article{blond2008pushing,
title={Pushing BitTorrent Locality to the Limit},
author={Stevens Le Blond (INRIA Sophia Antipolis / INRIA Rh^one-Alpes),
Arnaud Legout (INRIA Sophia Antipolis / INRIA Rh^one-Alpes), Walid Dabbous
(INRIA Sophia Antipolis / INRIA Rh^one-Alpes)},
journal={arXiv preprint arXiv:0812.0581},
year={2008},
archivePrefix={arXiv},
eprint={0812.0581},
primaryClass={cs.NI}
} | blond2008pushing |
arxiv-5628 | 0812.0598 | Preference Games and Personalized Equilibria, with Applications to Fractional BGP | <|reference_start|>Preference Games and Personalized Equilibria, with Applications to Fractional BGP: We study the complexity of computing equilibria in two classes of network games based on flows - fractional BGP (Border Gateway Protocol) games and fractional BBC (Bounded Budget Connection) games. BGP is the glue that holds the Internet together and hence its stability, i.e. the equilibria of fractional BGP games (Haxell, Wilfong), is a matter of practical importance. BBC games (Laoutaris et al) follow in the tradition of the large body of work on network formation games and capture a variety of applications ranging from social networks and overlay networks to peer-to-peer networks. The central result of this paper is that there are no fully polynomial-time approximation schemes (unless PPAD is in FP) for computing equilibria in both fractional BGP games and fractional BBC games. We obtain this result by proving the hardness for a new and surprisingly simple game, the fractional preference game, which is reducible to both fractional BGP and BBC games. We define a new flow-based notion of equilibrium for matrix games -- personalized equilibria -- generalizing both fractional BBC and fractional BGP games. We prove not just the existence, but the existence of rational personalized equilibria for all matrix games, which implies the existence of rational equilibria for fractional BGP and BBC games. In particular, this provides an alternative proof and strengthening of the main result in [Haxell, Wilfong]. For k-player matrix games, where k = 2, we provide a combinatorial characterization leading to a polynomial-time algorithm for computing all personalized equilibria. For k >= 5, we prove that personalized equilibria are PPAD-hard to approximate in fully polynomial time. We believe that the concept of personalized equilibria has potential for real-world significance.<|reference_end|> | arxiv | @article{poplawski2008preference,
title={Preference Games and Personalized Equilibria, with Applications to
Fractional BGP},
author={Laura J. Poplawski, Rajmohan Rajaraman, Ravi Sundaram and Shang-Hua
Teng},
journal={arXiv preprint arXiv:0812.0598},
year={2008},
archivePrefix={arXiv},
eprint={0812.0598},
primaryClass={cs.GT cs.DS}
} | poplawski2008preference |
arxiv-5629 | 0812.0601 | Polynomial relations among principal minors of a 4x4-matrix | <|reference_start|>Polynomial relations among principal minors of a 4x4-matrix: The image of the principal minor map for n x n-matrices is shown to be closed. In the 19th century, Nansen and Muir studied the implicitization problem of finding all relations among principal minors when n=4. We complete their partial results by constructing explicit polynomials of degree 12 that scheme-theoretically define this affine variety and also its projective closure in $\PP^{15}$. The latter is the main component in the singular locus of the 2 x 2 x 2 x 2-hyperdeterminant.<|reference_end|> | arxiv | @article{lin2008polynomial,
title={Polynomial relations among principal minors of a 4x4-matrix},
author={Shaowei Lin, Bernd Sturmfels},
journal={arXiv preprint arXiv:0812.0601},
year={2008},
archivePrefix={arXiv},
eprint={0812.0601},
primaryClass={math.AG cs.SC math.AC}
} | lin2008polynomial |
arxiv-5630 | 0812.0607 | Dilation, smoothed distance, and minimization diagrams of convex functions | <|reference_start|>Dilation, smoothed distance, and minimization diagrams of convex functions: We study Voronoi diagrams for distance functions that add together two convex functions, each taking as its argument the difference between Cartesian coordinates of two planar points. When the functions do not grow too quickly, then the Voronoi diagram has linear complexity and can be constructed in near-linear randomized expected time. Additionally, the level sets of the distances from the sites form a family of pseudocircles in the plane, all cells in the Voronoi diagram are connected, and the set of bisectors separating any one cell in the diagram from each of the others forms an arrangement of pseudolines in the plane. We apply these results to the smoothed distance or biotope transform metric, a geometric analogue of the Jaccard distance whose Voronoi diagrams can be used to determine the dilation of a star network with a given hub. For sufficiently closely spaced points in the plane, the Voronoi diagram of smoothed distance has linear complexity and can be computed efficiently. We also experiment with a variant of Lloyd's algorithm, adapted to smoothed distance, to find uniformly spaced point samples with exponentially decreasing density around a given point.<|reference_end|> | arxiv | @article{dickerson2008dilation,,
title={Dilation, smoothed distance, and minimization diagrams of convex
functions},
author={Matthew Dickerson, David Eppstein, and Kevin A. Wortman},
journal={arXiv preprint arXiv:0812.0607},
year={2008},
archivePrefix={arXiv},
eprint={0812.0607},
primaryClass={cs.CG}
} | dickerson2008dilation, |
arxiv-5631 | 0812.0617 | The Capacity Region of the Cognitive Z-interference Channel with One Noiseless Component | <|reference_start|>The Capacity Region of the Cognitive Z-interference Channel with One Noiseless Component: We study the discrete memoryless Z-interference channel (ZIC) where the transmitter of the pair that suffers from interference is cognitive. We first provide upper and lower bounds on the capacity of this channel. We then show that, when the channel of the transmitter-receiver pair that does not face interference is noiseless, the two bounds coincide and therefore yield the capacity region. The obtained results imply that, unlike in the Gaussian cognitive ZIC, in the considered channel superposition encoding at the non-cognitive transmitter as well as Gel'fand-Pinsker encoding at the cognitive transmitter are needed in order to minimize the impact of interference. As a byproduct of the obtained capacity region, we obtain the capacity result for a generalized Gel'fand-Pinsker problem.<|reference_end|> | arxiv | @article{liu2008the,
title={The Capacity Region of the Cognitive Z-interference Channel with One
Noiseless Component},
author={Nan Liu, Ivana Maric, Andrea Goldsmith and Shlomo Shamai (Shitz)},
journal={arXiv preprint arXiv:0812.0617},
year={2008},
archivePrefix={arXiv},
eprint={0812.0617},
primaryClass={cs.IT math.IT}
} | liu2008the |
arxiv-5632 | 0812.0621 | Channel Estimation and Linear Precoding in Multiuser Multiple-Antenna TDD Systems | <|reference_start|>Channel Estimation and Linear Precoding in Multiuser Multiple-Antenna TDD Systems: Traditional approaches in the analysis of downlink systems decouple the precoding and the channel estimation problems. However, in cellular systems with mobile users, these two problems are in fact tightly coupled. In this paper, this coupling is explicitly studied by accounting for channel training overhead and estimation error while determining the overall system throughput. The paper studies the problem of utilizing imperfect channel estimates for efficient linear precoding and user selection. It presents precoding methods that take into account the degree of channel estimation error. Information-theoretic lower and upper bounds are derived to evaluate the performance of these precoding methods. In typical scenarios, these bounds are close.<|reference_end|> | arxiv | @article{jose2008channel,
title={Channel Estimation and Linear Precoding in Multiuser Multiple-Antenna
TDD Systems},
author={Jubin Jose, Alexei Ashikhmin, Phil Whiting, Sriram Vishwanath},
journal={IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 60, NO. 5, JUNE
2011},
year={2008},
doi={10.1109/TVT.2011.2146797},
archivePrefix={arXiv},
eprint={0812.0621},
primaryClass={cs.IT math.IT}
} | jose2008channel |
arxiv-5633 | 0812.0629 | Dynamic spectrum sharing game by lease | <|reference_start|>Dynamic spectrum sharing game by lease: We propose and analyze a dynamic implementation of the property-rights model of cognitive radio. A primary link has the possibility to lease the owned spectrum to a MAC network of secondary nodes, in exchange for cooperation in the form of distributed space-time coding (DSTC). The cooperation and competition between the primary and secondary network are cast in the framework of sequential game. On one hand, the primary link attempts to maximize its quality of service in terms of signal-to-interference-plus-noise ratio (SINR); on the other hand, nodes in the secondary network compete for transmission within the leased time-slot following a power control mechanism. We consider both a baseline model with complete information and a more practical version with incomplete information, using the backward induction approach for the former and providing approximate algorithm for the latter. Analysis and numerical results show that our models and algorithms provide a promising framework for fair and effective spectrum sharing, both between primary and secondary networks and among secondary nodes.<|reference_end|> | arxiv | @article{li2008dynamic,
title={Dynamic spectrum sharing game by lease},
author={Cuilian Li (1 and 2), Zhen Yang (1), Jun Li (2), Feng Tian (1) ((1)
Nanjing University of Posts & Telecommunications, (2) Zhejiang Wanli
University)},
journal={arXiv preprint arXiv:0812.0629},
year={2008},
archivePrefix={arXiv},
eprint={0812.0629},
primaryClass={cs.GT}
} | li2008dynamic |
arxiv-5634 | 0812.0635 | Analysis of Group Multiuser Detection Based on Coalitional Game | <|reference_start|>Analysis of Group Multiuser Detection Based on Coalitional Game: The issue of group-blind multiuser detection in MAC channel among wireless nodes in the environment of multiple networks coexisting and sharing spectrum is addressed under the Framework of coalitional game. We investigate the performance and stability of multiple access channel (MAC) with linear decorrelating multiuser detection under varying SNR, channel gains and coalitional structures, in which both single BS and multiple BSs cases were considered. The main results and conclusion are as follows: (1) the grand coalition is payoff maximizing under loose SNR; (2) it is in conformity with group and coalitional rationality forming coalition among nodes that have comparative channel gains.<|reference_end|> | arxiv | @article{li2008analysis,
title={Analysis of Group Multiuser Detection Based on Coalitional Game},
author={Cuilian Li (1 and 2), Zhen Yang (1) ((1) Nanjing University of Posts &
Telecommunications, (2) Zhejiang Wanli University)},
journal={arXiv preprint arXiv:0812.0635},
year={2008},
archivePrefix={arXiv},
eprint={0812.0635},
primaryClass={cs.GT}
} | li2008analysis |
arxiv-5635 | 0812.0659 | Probabilistic reasoning with answer sets | <|reference_start|>Probabilistic reasoning with answer sets: This paper develops a declarative language, P-log, that combines logical and probabilistic arguments in its reasoning. Answer Set Prolog is used as the logical foundation, while causal Bayes nets serve as a probabilistic foundation. We give several non-trivial examples and illustrate the use of P-log for knowledge representation and updating of knowledge. We argue that our approach to updates is more appealing than existing approaches. We give sufficiency conditions for the coherency of P-log programs and show that Bayes nets can be easily mapped to coherent P-log programs.<|reference_end|> | arxiv | @article{baral2008probabilistic,
title={Probabilistic reasoning with answer sets},
author={Chitta Baral, Michael Gelfond and Nelson Rushton},
journal={arXiv preprint arXiv:0812.0659},
year={2008},
archivePrefix={arXiv},
eprint={0812.0659},
primaryClass={cs.AI cs.LO}
} | baral2008probabilistic |
arxiv-5636 | 0812.0686 | Cryptanalysis of the RSA-CEGD protocol | <|reference_start|>Cryptanalysis of the RSA-CEGD protocol: Recently, Nenadi\'c et al. (2004) proposed the RSA-CEGD protocol for certified delivery of e-goods. This is a relatively complex scheme based on verifiable and recoverable encrypted signatures (VRES) to guarantee properties such as strong fairness and non-repudiation, among others. In this paper, we demonstrate how this protocol cannot achieve fairness by presenting a severe attack and also pointing out some other weaknesses.<|reference_end|> | arxiv | @article{tapiador2008cryptanalysis,
title={Cryptanalysis of the RSA-CEGD protocol},
author={Juan M. E. Tapiador, Almudena Alcaide, Julio C. Hernandez-Castro,
Arturo Ribagorda},
journal={arXiv preprint arXiv:0812.0686},
year={2008},
archivePrefix={arXiv},
eprint={0812.0686},
primaryClass={cs.CR}
} | tapiador2008cryptanalysis |
arxiv-5637 | 0812.0698 | Emergent Community Structure in Social Tagging Systems | <|reference_start|>Emergent Community Structure in Social Tagging Systems: A distributed classification paradigm known as collaborative tagging has been widely adopted in new Web applications designed to manage and share online resources. Users of these applications organize resources (Web pages, digital photographs, academic papers) by associating with them freely chosen text labels, or tags. Here we leverage the social aspects of collaborative tagging and introduce a notion of resource distance based on the collective tagging activity of users. We collect data from a popular system and perform experiments showing that our definition of distance can be used to build a weighted network of resources with a detectable community structure. We show that this community structure clearly exposes the semantic relations among resources. The communities of resources that we observe are a genuinely emergent feature, resulting from the uncoordinated activity of a large number of users, and their detection paves the way for mapping emergent semantics in social tagging systems.<|reference_end|> | arxiv | @article{cattuto2008emergent,
title={Emergent Community Structure in Social Tagging Systems},
author={Ciro Cattuto, Andrea Baldassarri, Vito D.P. Servedio, and Vittorio
Loreto},
journal={Advances in Complex Systems 11, 597 (2008)},
year={2008},
archivePrefix={arXiv},
eprint={0812.0698},
primaryClass={cs.IR cs.CY cs.HC}
} | cattuto2008emergent |
arxiv-5638 | 0812.0706 | Which notes are Vadi-Samvadi in Raga Rageshree? | <|reference_start|>Which notes are Vadi-Samvadi in Raga Rageshree?: The notes which play the most important and second most important roles in expressing a raga are called Vadi and Samvadi swars respectively in (North) Indian Classical music. Like Bageshree, Bhairavi, Shankara, Hamir and Kalingra, Rageshree is another controversial raga so far as the choice of Vadi-Samvadi selection is concerned where there are two different opinions. In the present work, a two minute vocal recording of raga Rageshree is subjected to a careful statistical analysis. Our analysis is broken into three phases: first half, middle half and last half. Under a multinomial model set up holding appreciably in the first two phases, only one opinion is found acceptable. In the last phase the distribution seems to be quasi multinomial, characterized by an unstable nature of relative occurrence of pitch of all the notes and although the note whose relative occurrence of pitch suddenly shoots is the Vadi swar selected from our analysis of the first two phases, we take it as an outlier demanding a separate treatment like any other in statistics. Selection of Vadi-Samvadi notes in a quasi-multinomial set up is still an open research problem. An interesting musical cocktail is proposed, however, embedding several ideas like melodic property of notes, note combinations and pitch movements between notes, using some weighted combination of psychological and statistical stability of notes along with watching carefully the sudden shoot of one or more notes whenever there is enough evidence that multinomial model has broken down.<|reference_end|> | arxiv | @article{chakraborty2008which,
title={Which notes are Vadi-Samvadi in Raga Rageshree?},
author={Soubhik Chakraborty, Rayalla Ranganayakulu, Shivee Chauhan, Sandeep
Singh Solanki and Kartik Mahto},
journal={arXiv preprint arXiv:0812.0706},
year={2008},
archivePrefix={arXiv},
eprint={0812.0706},
primaryClass={cs.SD}
} | chakraborty2008which |
arxiv-5639 | 0812.0736 | Fully distributed and fault tolerant task management based on diffusions | <|reference_start|>Fully distributed and fault tolerant task management based on diffusions: The task management is a critical component for the computational grids. The aim is to assign tasks on nodes according to a global scheduling policy and a view of local resources of nodes. A peer-to-peer approach for the task management involves a better scalability for the grid and a higher fault tolerance. But some mechanisms have to be proposed to avoid the computation of replicated tasks that can reduce the efficiency and increase the load of nodes. In the same way, these mechanisms have to limit the number of exchanged messages to avoid the overload of the network. In a previous paper, we have proposed two methods for the task management called active and passive. These methods are based on a random walk: they are fully distributed and fault tolerant. Each node owns a local tasks states set updated thanks to a random walk and each node is in charge of the local assignment. Here, we propose three methods to improve the efficiency of the active method. These new methods are based on a circulating word. The nodes local tasks states sets are updated thanks to periodical diffusions along trees built from the circulating word. Particularly, we show that these methods increase the efficiency of the active method: they produce less replicated tasks. These three methods are also fully distributed and fault tolerant. On the other way, the circulating word can be exploited for other applications like the resources management or the nodes synchronization.<|reference_end|> | arxiv | @article{bui2008fully,
title={Fully distributed and fault tolerant task management based on diffusions},
author={Alain Bui, Olivier Flauzac, Cyril Rabat},
journal={arXiv preprint arXiv:0812.0736},
year={2008},
archivePrefix={arXiv},
eprint={0812.0736},
primaryClass={cs.DC}
} | bui2008fully |
arxiv-5640 | 0812.0743 | A Novel Clustering Algorithm Based on Quantum Games | <|reference_start|>A Novel Clustering Algorithm Based on Quantum Games: Enormous successes have been made by quantum algorithms during the last decade. In this paper, we combine the quantum game with the problem of data clustering, and then develop a quantum-game-based clustering algorithm, in which data points in a dataset are considered as players who can make decisions and implement quantum strategies in quantum games. After each round of a quantum game, each player's expected payoff is calculated. Later, he uses a link-removing-and-rewiring (LRR) function to change his neighbors and adjust the strength of links connecting to them in order to maximize his payoff. Further, algorithms are discussed and analyzed in two cases of strategies, two payoff matrixes and two LRR functions. Consequently, the simulation results have demonstrated that data points in datasets are clustered reasonably and efficiently, and the clustering algorithms have fast rates of convergence. Moreover, the comparison with other algorithms also provides an indication of the effectiveness of the proposed approach.<|reference_end|> | arxiv | @article{li2008a,
title={A Novel Clustering Algorithm Based on Quantum Games},
author={Qiang Li, Yan He, Jing-ping Jiang},
journal={2009 J. Phys. A: Math. Theor. 42 445303},
year={2008},
doi={10.1088/1751-8113/42/44/445303},
archivePrefix={arXiv},
eprint={0812.0743},
primaryClass={cs.LG cs.AI cs.CV cs.GT cs.MA cs.NE quant-ph}
} | li2008a |
arxiv-5641 | 0812.0754 | Strong Spatial Mixing and Approximating Partition Functions of Two-State Spin Systems without Hard Constrains | <|reference_start|>Strong Spatial Mixing and Approximating Partition Functions of Two-State Spin Systems without Hard Constrains: We prove Gibbs distribution of two-state spin systems(also known as binary Markov random fields) without hard constrains on a tree exhibits strong spatial mixing(also known as strong correlation decay), under the assumption that, for arbitrary `external field', the absolute value of `inverse temperature' is small, or the `external field' is uniformly large or small. The first condition on `inverse temperature' is tight if the distribution is restricted to ferromagnetic or antiferromagnetic Ising models. Thanks to Weitz's self-avoiding tree, we extends the result for sparse on average graphs, which generalizes part of the recent work of Mossel and Sly\cite{MS08}, who proved the strong spatial mixing property for ferromagnetic Ising model. Our proof yields a different approach, carefully exploiting the monotonicity of local recursion. To our best knowledge, the second condition of `external field' for strong spatial mixing in this paper is first considered and stated in term of `maximum average degree' and `interaction energy'. As an application, we present an FPTAS for partition functions of two-state spin models without hard constrains under the above assumptions in a general family of graphs including interesting bounded degree graphs.<|reference_end|> | arxiv | @article{zhang2008strong,
title={Strong Spatial Mixing and Approximating Partition Functions of Two-State
Spin Systems without Hard Constrains},
author={Jinshan Zhang},
journal={arXiv preprint arXiv:0812.0754},
year={2008},
archivePrefix={arXiv},
eprint={0812.0754},
primaryClass={cs.DM cs.GR}
} | zhang2008strong |
arxiv-5642 | 0812.0759 | A new Contrast Based Image Fusion using Wavelet Packets | <|reference_start|>A new Contrast Based Image Fusion using Wavelet Packets: Image Fusion, a technique which combines complimentary information from different images of the same scene so that the fused image is more suitable for segmentation, feature extraction, object recognition and Human Visual System. In this paper, a simple yet efficient algorithm is presented based on contrast using wavelet packet decomposition. First, all the source images are decomposed into low and high frequency sub-bands and then fusion of high frequency sub-bands is done by the means of Directive Contrast. Now, inverse wavelet packet transform is performed to reconstruct the fused image. The performance of the algorithm is carried out by the comparison made between proposed and existing algorithm.<|reference_end|> | arxiv | @article{balasubramanian2008a,
title={A new Contrast Based Image Fusion using Wavelet Packets},
author={R. Balasubramanian, Gaurav Bhatnagar},
journal={Proc. of IEEE Conference on Applications of Intelligent Systems
(AIS 2008), March 13-15, 2008, Sonepat, India, pp. 141-145.
(ISBN:978-81-906531-0-7)},
year={2008},
archivePrefix={arXiv},
eprint={0812.0759},
primaryClass={cs.IT cs.MM math.IT}
} | balasubramanian2008a |
arxiv-5643 | 0812.0790 | Justifications for Logic Programs under Answer Set Semantics | <|reference_start|>Justifications for Logic Programs under Answer Set Semantics: The paper introduces the notion of off-line justification for Answer Set Programming (ASP). Justifications provide a graph-based explanation of the truth value of an atom w.r.t. a given answer set. The paper extends also this notion to provide justification of atoms during the computation of an answer set (on-line justification), and presents an integration of on-line justifications within the computation model of Smodels. Off-line and on-line justifications provide useful tools to enhance understanding of ASP, and they offer a basic data structure to support methodologies and tools for debugging answer set programs. A preliminary implementation has been developed in ASP-PROLOG. (To appear in Theory and Practice of Logic Programming (TPLP))<|reference_end|> | arxiv | @article{pontelli2008justifications,
title={Justifications for Logic Programs under Answer Set Semantics},
author={Enrico Pontelli, Tran Cao Son, and Omar Elkhatib},
journal={arXiv preprint arXiv:0812.0790},
year={2008},
archivePrefix={arXiv},
eprint={0812.0790},
primaryClass={cs.AI cs.PL}
} | pontelli2008justifications |
arxiv-5644 | 0812.0852 | Hierarchy and equivalence of multi-letter quantum finite automata | <|reference_start|>Hierarchy and equivalence of multi-letter quantum finite automata: Multi-letter {\it quantum finite automata} (QFAs) were a new one-way QFA model proposed recently by Belovs, Rosmanis, and Smotrovs (LNCS, Vol. 4588, Springer, Berlin, 2007, pp. 60-71), and they showed that multi-letter QFAs can accept with no error some regular languages ($(a+b)^{*}b$) that are unacceptable by the one-way QFAs. In this paper, we continue to study multi-letter QFAs. We mainly focus on two issues: (1) we show that $(k+1)$-letter QFAs are computationally more powerful than $k$-letter QFAs, that is, $(k+1)$-letter QFAs can accept some regular languages that are unacceptable by any $k$-letter QFA. A comparison with the one-way QFAs is made by some examples; (2) we prove that a $k_{1}$-letter QFA ${\cal A}_1$ and another $k_{2}$-letter QFA ${\cal A}_2$ are equivalent if and only if they are $(n_{1}+n_{2})^{4}+k-1$-equivalent, and the time complexity of determining the equivalence of two multi-letter QFAs using this method is $O(n^{12}+k^{2}n^{4}+kn^{8})$, where $n_{1}$ and $n_{2}$ are the numbers of states of ${\cal A}_{1}$ and ${\cal A}_{2}$, respectively, and $k=\max(k_{1},k_{2})$. Some other issues are addressed for further consideration.<|reference_end|> | arxiv | @article{qiu2008hierarchy,
title={Hierarchy and equivalence of multi-letter quantum finite automata},
author={Daowen Qiu, Sheng Yu},
journal={Theoretical Computer Science, 410 (30-32) (2009) 3006-3017.},
year={2008},
archivePrefix={arXiv},
eprint={0812.0852},
primaryClass={cs.CC}
} | qiu2008hierarchy |
arxiv-5645 | 0812.0872 | Rigid Components of Random Graphs | <|reference_start|>Rigid Components of Random Graphs: The planar rigidity problem asks, given a set of m pairwise distances among a set P of n unknown points, whether it is possible to reconstruct P, up to a finite set of possibilities (modulo rigid motions of the plane). The celebrated Maxwell-Laman Theorem from Rigidity Theory says that, generically, the rigidity problem has a combinatorial answer: the underlying combinatorial structure must contain a spanning minimally-rigid graph (Laman graph). In the case where the system is not rigid, its inclusion-wise maximal rigid substructures (rigid components) are also combinatorially characterized via the Maxwell-Laman theorem, and may be found efficiently. Physicists have used planar combinatorial rigidity has been used to study the phase transition between liquid and solid in network glasses. The approach has been to generate a graph via a stochastic process and then experimentally analyze its rigidity properties. Of particular interest is the size of the largest rigid components. In this paper, we study the emergence of rigid components in an Erdos-Renyi random graph G(n,p), using the parameterization p=c/n for a fixed constant c>0. Our first result is that for all c>0, almost surely all rigid components have size 2, 3 or Omega(n). We also show that for c>4, almost surely the largest rigid components have size at least n/10. While the G(n,p) model is simpler than those appearing in the physics literature, these results are the first of this type where the distribution is over all graphs on n vertices and the expected number of edges is O(n).<|reference_end|> | arxiv | @article{theran2008rigid,
title={Rigid Components of Random Graphs},
author={Louis Theran},
journal={arXiv preprint arXiv:0812.0872},
year={2008},
archivePrefix={arXiv},
eprint={0812.0872},
primaryClass={math.CO cs.CG}
} | theran2008rigid |
arxiv-5646 | 0812.0874 | Stroke Fragmentation based on Geometry Features and HMM | <|reference_start|>Stroke Fragmentation based on Geometry Features and HMM: Stroke fragmentation is one of the key steps in pen-based interaction. In this letter, we present a unified HMM-based stroke fragmentation technique that can do segment point location and primitive type determination simultaneously. The geometry features included are used to evaluate local features, and the HMM model is utilized to measure the global drawing context. Experiments prove that the model can efficiently represent smooth curves as well as strokes made up of arbitrary lines and circular arcs.<|reference_end|> | arxiv | @article{feng2008stroke,
title={Stroke Fragmentation based on Geometry Features and HMM},
author={Guihuan Feng (IRCCyN), Christian Viard-Gaudin (IRCCyN)},
journal={arXiv preprint arXiv:0812.0874},
year={2008},
archivePrefix={arXiv},
eprint={0812.0874},
primaryClass={cs.HC cs.CV}
} | feng2008stroke |
arxiv-5647 | 0812.0882 | Elagage d'un perceptron multicouches : utilisation de l'analyse de la variance de la sensibilit\'e des param\`etres | <|reference_start|>Elagage d'un perceptron multicouches : utilisation de l'analyse de la variance de la sensibilit\'e des param\`etres: The stucture determination of a neural network for the modelisation of a system remain the core of the problem. Within this framework, we propose a pruning algorithm of the network based on the use of the analysis of the sensitivity of the variance of all the parameters of the network. This algorithm will be tested on two examples of simulation and its performances will be compared with three other algorithms of pruning of the literature<|reference_end|> | arxiv | @article{thomas2008elagage,
title={Elagage d'un perceptron multicouches : utilisation de l'analyse de la
variance de la sensibilit\'e des param\`etres},
author={Philippe Thomas (CRAN), Andr'e Thomas (CRAN)},
journal={Conf\'erence Internationale Francophone d'Automatique CIFA'08,
Bucarest : Roumanie (2008)},
year={2008},
archivePrefix={arXiv},
eprint={0812.0882},
primaryClass={cs.NE}
} | thomas2008elagage |
arxiv-5648 | 0812.0885 | Elementary epistemological features of machine intelligence | <|reference_start|>Elementary epistemological features of machine intelligence: Theoretical analysis of machine intelligence (MI) is useful for defining a common platform in both theoretical and applied artificial intelligence (AI). The goal of this paper is to set canonical definitions that can assist pragmatic research in both strong and weak AI. Described epistemological features of machine intelligence include relationship between intelligent behavior, intelligent and unintelligent machine characteristics, observable and unobservable entities and classification of intelligence. The paper also establishes algebraic definitions of efficiency and accuracy of MI tests as their quality measure. The last part of the paper addresses the learning process with respect to the traditional epistemology and the epistemology of MI described here. The proposed views on MI positively correlate to the Hegelian monistic epistemology and contribute towards amalgamating idealistic deliberations with the AI theory, particularly in a local frame of reference.<|reference_end|> | arxiv | @article{horvat2008elementary,
title={Elementary epistemological features of machine intelligence},
author={Marko Horvat},
journal={arXiv preprint arXiv:0812.0885},
year={2008},
archivePrefix={arXiv},
eprint={0812.0885},
primaryClass={cs.AI}
} | horvat2008elementary |
arxiv-5649 | 0812.0893 | Linear-Time Algorithms for Geometric Graphs with Sublinearly Many Edge Crossings | <|reference_start|>Linear-Time Algorithms for Geometric Graphs with Sublinearly Many Edge Crossings: We provide linear-time algorithms for geometric graphs with sublinearly many crossings. That is, we provide algorithms running in O(n) time on connected geometric graphs having n vertices and k crossings, where k is smaller than n by an iterated logarithmic factor. Specific problems we study include Voronoi diagrams and single-source shortest paths. Our algorithms all run in linear time in the standard comparison-based computational model; hence, we make no assumptions about the distribution or bit complexities of edge weights, nor do we utilize unusual bit-level operations on memory words. Instead, our algorithms are based on a planarization method that "zeroes in" on edge crossings, together with methods for extending planar separator decompositions to geometric graphs with sublinearly many crossings. Incidentally, our planarization algorithm also solves an open computational geometry problem of Chazelle for triangulating a self-intersecting polygonal chain having n segments and k crossings in linear time, for the case when k is sublinear in n by an iterated logarithmic factor.<|reference_end|> | arxiv | @article{eppstein2008linear-time,
title={Linear-Time Algorithms for Geometric Graphs with Sublinearly Many Edge
Crossings},
author={David Eppstein, Michael T. Goodrich and Darren Strash},
journal={SIAM J. Computing 39(8): 3814-3829, 2010},
year={2008},
doi={10.1137/090759112},
archivePrefix={arXiv},
eprint={0812.0893},
primaryClass={cs.CG cs.DM cs.DS cs.GR}
} | eppstein2008linear-time |
arxiv-5650 | 0812.0904 | An Approximation of the Outage Probability for Multi-hop AF Fixed Gain Relay | <|reference_start|>An Approximation of the Outage Probability for Multi-hop AF Fixed Gain Relay: In this letter, we present a closed-form approximation of the outage probability for the multi-hop amplify-and-forward (AF) relaying systems with fixed gain in Rayleigh fading channel. The approximation is derived from the outage event for each hop. The simulation results show the tightness of the proposed approximation in low and high signal-to-noise ratio (SNR) region.<|reference_end|> | arxiv | @article{lee2008an,
title={An Approximation of the Outage Probability for Multi-hop AF Fixed Gain
Relay},
author={Jun Kyoung Lee, Janghoon Yang, Dong Ku Kim},
journal={arXiv preprint arXiv:0812.0904},
year={2008},
archivePrefix={arXiv},
eprint={0812.0904},
primaryClass={cs.PF}
} | lee2008an |
arxiv-5651 | 0812.0933 | Decision trees are PAC-learnable from most product distributions: a smoothed analysis | <|reference_start|>Decision trees are PAC-learnable from most product distributions: a smoothed analysis: We consider the problem of PAC-learning decision trees, i.e., learning a decision tree over the n-dimensional hypercube from independent random labeled examples. Despite significant effort, no polynomial-time algorithm is known for learning polynomial-sized decision trees (even trees of any super-constant size), even when examples are assumed to be drawn from the uniform distribution on {0,1}^n. We give an algorithm that learns arbitrary polynomial-sized decision trees for {\em most product distributions}. In particular, consider a random product distribution where the bias of each bit is chosen independently and uniformly from, say, [.49,.51]. Then with high probability over the parameters of the product distribution and the random examples drawn from it, the algorithm will learn any tree. More generally, in the spirit of smoothed analysis, we consider an arbitrary product distribution whose parameters are specified only up to a [-c,c] accuracy (perturbation), for an arbitrarily small positive constant c.<|reference_end|> | arxiv | @article{kalai2008decision,
title={Decision trees are PAC-learnable from most product distributions: a
smoothed analysis},
author={Adam Tauman Kalai and Shang-Hua Teng},
journal={arXiv preprint arXiv:0812.0933},
year={2008},
archivePrefix={arXiv},
eprint={0812.0933},
primaryClass={cs.LG cs.CC}
} | kalai2008decision |
arxiv-5652 | 0812.0956 | EcoTRADE - a multi player network game of a tradable permit market for biodiversity credits | <|reference_start|>EcoTRADE - a multi player network game of a tradable permit market for biodiversity credits: EcoTRADE is a multi player network game of a virtual biodiversity credit market. Each player controls the land use of a certain amount of parcels on a virtual landscape. The biodiversity credits of a particular parcel depend on neighboring parcels, which may be owned by other players. The game can be used to study the strategies of players in experiments or classroom games and also as a communication tool for stakeholders participating in credit markets that include spatially interdependent credits.<|reference_end|> | arxiv | @article{hartig2008ecotrade,
title={EcoTRADE - a multi player network game of a tradable permit market for
biodiversity credits},
author={Florian Hartig, Martin Horn, Martin Drechsler},
journal={Environmental Modelling & Software, 2010, 25, 1479-1480},
year={2008},
doi={10.1016/j.envsoft.2009.01.003},
archivePrefix={arXiv},
eprint={0812.0956},
primaryClass={cs.GT}
} | hartig2008ecotrade |
arxiv-5653 | 0812.0972 | Network Protection Codes: Providing Self-healing in Autonomic Networks Using Network Coding | <|reference_start|>Network Protection Codes: Providing Self-healing in Autonomic Networks Using Network Coding: Agile recovery from link failures in autonomic communication networks is essential to increase robustness, accessibility, and reliability of data transmission. However, this must be done with the least amount of protection resources, while using simple management plane functionality. Recently, network coding has been proposed as a solution to provide agile and cost efficient network self-healing against link failures, in a manner that does not require data rerouting, packet retransmission, or failure localization, hence leading to simple control and management planes. To achieve this, separate paths have to be provisioned to carry encoded packets, hence requiring either the addition of extra links, or reserving some of the resources for this purpose. In this paper we introduce autonomic self-healing strategies for autonomic networks in order to protect against link failures. The strategies are based on network coding and reduced capacity, which is a technique that we call network protection codes (NPC). In these strategies, an autonomic network is able to provide self-healing from various network failures affecting network operation. The techniques improve service and enhance reliability of autonomic communication. Network protection codes are extended to provide self-healing from multiple link failures in autonomic networks. We provide implementation aspects of the proposed strategies. We present bounds and network protection code constructions. Finally, we study the construction of such codes over the binary field. The paper also develops an Integer Linear Program formulation to evaluate the cost of provisioning connections using the proposed strategies.<|reference_end|> | arxiv | @article{aly2008network,
title={Network Protection Codes: Providing Self-healing in Autonomic Networks
Using Network Coding},
author={Salah A. Aly, Ahmed E. Kamal},
journal={arXiv preprint arXiv:0812.0972},
year={2008},
archivePrefix={arXiv},
eprint={0812.0972},
primaryClass={cs.NI cs.IT math.IT}
} | aly2008network |
arxiv-5654 | 0812.1012 | Adaptive Uncertainty Resolution in Bayesian Combinatorial Optimization Problems | <|reference_start|>Adaptive Uncertainty Resolution in Bayesian Combinatorial Optimization Problems: In several applications such as databases, planning, and sensor networks, parameters such as selectivity, load, or sensed values are known only with some associated uncertainty. The performance of such a system (as captured by some objective function over the parameters) is significantly improved if some of these parameters can be probed or observed. In a resource constrained situation, deciding which parameters to observe in order to optimize system performance itself becomes an interesting and important optimization problem. This general problem is the focus of this paper. One of the most important considerations in this framework is whether adaptivity is required for the observations. Adaptive observations introduce blocking or sequential operations in the system whereas non-adaptive observations can be performed in parallel. One of the important questions in this regard is to characterize the benefit of adaptivity for probes and observation. We present general techniques for designing constant factor approximations to the optimal observation schemes for several widely used scheduling and metric objective functions. We show a unifying technique that relates this optimization problem to the outlier version of the corresponding deterministic optimization. By making this connection, our technique shows constant factor upper bounds for the benefit of adaptivity of the observation schemes. We show that while probing yields significant improvement in the objective function, being adaptive about the probing is not beneficial beyond constant factors.<|reference_end|> | arxiv | @article{guha2008adaptive,
title={Adaptive Uncertainty Resolution in Bayesian Combinatorial Optimization
Problems},
author={Sudipto Guha and Kamesh Munagala},
journal={arXiv preprint arXiv:0812.1012},
year={2008},
archivePrefix={arXiv},
eprint={0812.1012},
primaryClass={cs.DS}
} | guha2008adaptive |
arxiv-5655 | 0812.1014 | Adaptive Spam Detection Inspired by a Cross-Regulation Model of Immune Dynamics: A Study of Concept Drift | <|reference_start|>Adaptive Spam Detection Inspired by a Cross-Regulation Model of Immune Dynamics: A Study of Concept Drift: This paper proposes a novel solution to spam detection inspired by a model of the adaptive immune system known as the crossregulation model. We report on the testing of a preliminary algorithm on six e-mail corpora. We also compare our results statically and dynamically with those obtained by the Naive Bayes classifier and another binary classification method we developed previously for biomedical text-mining applications. We show that the cross-regulation model is competitive against those and thus promising as a bio-inspired algorithm for spam detection in particular, and binary classification in general.<|reference_end|> | arxiv | @article{abi-haidar2008adaptive,
title={Adaptive Spam Detection Inspired by a Cross-Regulation Model of Immune
Dynamics: A Study of Concept Drift},
author={Alaa Abi-Haidar and Luis M. Rocha},
journal={Artificial Immune Systems: 7th International Conference, (ICARIS
2008). Bentley, Peter; Lee, Doheon; Jung, Sungwon (Eds.) Lecture Notes in
Computer Science. Springer-Verlag, 5132: 36-47},
year={2008},
doi={10.1007/978-3-540-85072-4_4},
archivePrefix={arXiv},
eprint={0812.1014},
primaryClass={cs.AI cs.IR nlin.AO}
} | abi-haidar2008adaptive |
arxiv-5656 | 0812.1029 | Uncovering protein interaction in abstracts and text using a novel linear model and word proximity networks | <|reference_start|>Uncovering protein interaction in abstracts and text using a novel linear model and word proximity networks: We participated in three of the protein-protein interaction subtasks of the Second BioCreative Challenge: classification of abstracts relevant for protein-protein interaction (IAS), discovery of protein pairs (IPS) and text passages characterizing protein interaction (ISS) in full text documents. We approached the abstract classification task with a novel, lightweight linear model inspired by spam-detection techniques, as well as an uncertainty-based integration scheme. We also used a Support Vector Machine and the Singular Value Decomposition on the same features for comparison purposes. Our approach to the full text subtasks (protein pair and passage identification) includes a feature expansion method based on word-proximity networks. Our approach to the abstract classification task (IAS) was among the top submissions for this task in terms of the measures of performance used in the challenge evaluation (accuracy, F-score and AUC). We also report on a web-tool we produced using our approach: the Protein Interaction Abstract Relevance Evaluator (PIARE). Our approach to the full text tasks resulted in one of the highest recall rates as well as mean reciprocal rank of correct passages. Our approach to abstract classification shows that a simple linear model, using relatively few features, is capable of generalizing and uncovering the conceptual nature of protein-protein interaction from the bibliome. Since the novel approach is based on a very lightweight linear model, it can be easily ported and applied to similar problems. In full text problems, the expansion of word features with word-proximity networks is shown to be useful, though the need for some improvements is discussed.<|reference_end|> | arxiv | @article{abi-haidar2008uncovering,
title={Uncovering protein interaction in abstracts and text using a novel
linear model and word proximity networks},
author={Alaa Abi-Haidar, Jasleen Kaur, Ana G. Maguitman, Predrag Radivojac,
Andreas Retchsteiner, Karin Verspoor, Zhiping Wang, Luis M. Rocha},
journal={Genome Biology 2008, 9(Suppl 2):S11},
year={2008},
doi={10.1186/gb-2008-9-s2-s11},
archivePrefix={arXiv},
eprint={0812.1029},
primaryClass={cs.IR cs.LG}
} | abi-haidar2008uncovering |
arxiv-5657 | 0812.1045 | Social networks that matter: Twitter under the microscope | <|reference_start|>Social networks that matter: Twitter under the microscope: Scholars, advertisers and political activists see massive online social networks as a representation of social interactions that can be used to study the propagation of ideas, social bond dynamics and viral marketing, among others. But the linked structures of social networks do not reveal actual interactions among people. Scarcity of attention and the daily rythms of life and work makes people default to interacting with those few that matter and that reciprocate their attention. A study of social interactions within Twitter reveals that the driver of usage is a sparse and hidden network of connections underlying the declared set of friends and followers.<|reference_end|> | arxiv | @article{huberman2008social,
title={Social networks that matter: Twitter under the microscope},
author={Bernardo A. Huberman, Daniel M. Romero, and Fang Wu},
journal={arXiv preprint arXiv:0812.1045},
year={2008},
archivePrefix={arXiv},
eprint={0812.1045},
primaryClass={cs.CY physics.soc-ph}
} | huberman2008social |
arxiv-5658 | 0812.1061 | Decidability of the Equivalence of Multi-Letter Quantum Finite Automata | <|reference_start|>Decidability of the Equivalence of Multi-Letter Quantum Finite Automata: Multi-letter {\it quantum finite automata} (QFAs) were a quantum variant of classical {\it one-way multi-head finite automata} (J. Hromkovi\v{c}, Acta Informatica 19 (1983) 377-384), and it has been shown that this new one-way QFAs (multi-letter QFAs) can accept with no error some regular languages $(a+b)^{*}b$ that are unacceptable by the previous one-way QFAs. In this paper, we study the decidability of the equivalence of multi-letter QFAs, and the main technical contributions are as follows: (1) We show that any two automata, a $k_{1}$-letter QFA ${\cal A}_1$ and a $k_{2}$-letter QFA ${\cal A}_2$, over the same input alphabet $\Sigma$ are equivalent if and only if they are $(n^2m^{k-1}-m^{k-1}+k)$-equivalent, where $m=|\Sigma|$ is the cardinality of $\Sigma$, $k=\max(k_{1},k_{2})$, and $n=n_{1}+n_{2}$, with $n_{1}$ and $n_{2}$ being the numbers of states of ${\cal A}_{1}$ and ${\cal A}_{2}$, respectively. When $k=1$, we obtain the decidability of equivalence of measure-once QFAs in the literature. It is worth mentioning that our technical method is essentially different from that for the decidability of the case of single input alphabet (i.e., $m=1$). (2) However, if we determine the equivalence of multi-letter QFAs by checking all strings of length not more than $ n^2m^{k-1}-m^{k-1}+k$, then the worst time complexity is exponential, i.e., $O(n^6m^{n^2m^{k-1}-m^{k-1}+2k-1})$. Therefore, we design a polynomial-time $O(m^{2k-1}n^{8}+km^kn^{6})$ algorithm for determining the equivalence of any two multi-letter QFAs. Here, the time complexity is concerning the number of states in the multi-letter QFAs, and $k$ is thought of as a constant.<|reference_end|> | arxiv | @article{qiu2008decidability,
title={Decidability of the Equivalence of Multi-Letter Quantum Finite Automata},
author={Daowen Qiu, Xiangfu Zou, Lvzhou Li, Paulo Mateus},
journal={arXiv preprint arXiv:0812.1061},
year={2008},
archivePrefix={arXiv},
eprint={0812.1061},
primaryClass={cs.FL cs.CC}
} | qiu2008decidability |
arxiv-5659 | 0812.1091 | Communicating the Difference of Correlated Gaussian Sources Over a MAC | <|reference_start|>Communicating the Difference of Correlated Gaussian Sources Over a MAC: This paper considers the problem of transmitting the difference of two jointly Gaussian sources over a two-user additive Gaussian noise multiple access channel (MAC). The goal is to recover this difference within an average mean squared error distortion criterion. Each transmitter has access to only one of the two Gaussian sources and is limited by an average power constraint. In this work, a lattice coding scheme that achieves a distortion within a constant of a distortion lower bound is presented if the signal to noise ratio (SNR) is greater than a threshold. Further, uncoded transmission is shown to be worse in performance to lattice coding methods. An alternative lattice coding scheme is presented that can potentially improve on the performance of uncoded transmission.<|reference_end|> | arxiv | @article{soundararajan2008communicating,
title={Communicating the Difference of Correlated Gaussian Sources Over a MAC},
author={Rajiv Soundararajan and Sriram Vishwanath},
journal={arXiv preprint arXiv:0812.1091},
year={2008},
archivePrefix={arXiv},
eprint={0812.1091},
primaryClass={cs.IT math.IT}
} | soundararajan2008communicating |
arxiv-5660 | 0812.1093 | Self-stabilizing K-out-of-L exclusion on tree network | <|reference_start|>Self-stabilizing K-out-of-L exclusion on tree network: In this paper, we address the problem of K-out-of-L exclusion, a generalization of the mutual exclusion problem, in which there are $\ell$ units of a shared resource, and any process can request up to $\mathtt k$ units ($1\leq\mathtt k\leq\ell$). We propose the first deterministic self-stabilizing distributed K-out-of-L exclusion protocol in message-passing systems for asynchronous oriented tree networks which assumes bounded local memory for each process.<|reference_end|> | arxiv | @article{datta2008self-stabilizing,
title={Self-stabilizing K-out-of-L exclusion on tree network},
author={Ajoy K. Datta (UNLV), St'ephane Devismes (VERIMAG - IMAG), Florian
Horn (LIAFA), Lawrence L. Larmore (UNLV)},
journal={arXiv preprint arXiv:0812.1093},
year={2008},
archivePrefix={arXiv},
eprint={0812.1093},
primaryClass={cs.NI}
} | datta2008self-stabilizing |
arxiv-5661 | 0812.1094 | S\'election de la structure d'un perceptron multicouches pour la r\'eduction dun mod\`ele de simulation d'une scierie | <|reference_start|>S\'election de la structure d'un perceptron multicouches pour la r\'eduction dun mod\`ele de simulation d'une scierie: Simulation is often used to evaluate the relevance of a Directing Program of Production (PDP) or to evaluate its impact on detailed sc\'enarii of scheduling. Within this framework, we propose to reduce the complexity of a model of simulation by exploiting a multilayer perceptron. A main phase of the modeling of one system using a multilayer perceptron remains the determination of the structure of the network. We propose to compare and use various pruning algorithms in order to determine the optimal structure of the network used to reduce the complexity of the model of simulation of our case of application: a sawmill.<|reference_end|> | arxiv | @article{thomas2008s\'election,
title={S\'election de la structure d'un perceptron multicouches pour la
r\'eduction dun mod\`ele de simulation d'une scierie},
author={Philippe Thomas (CRAN), Andr'e Thomas (CRAN)},
journal={Conf\'erence Internationale Francophone d'Automatique CIFA'08,
Bucarest : Roumanie (2008)},
year={2008},
archivePrefix={arXiv},
eprint={0812.1094},
primaryClass={cs.NE}
} | thomas2008s\'election |
arxiv-5662 | 0812.1119 | An analysis of a random algorithm for estimating all the matchings | <|reference_start|>An analysis of a random algorithm for estimating all the matchings: Counting the number of all the matchings on a bipartite graph has been transformed into calculating the permanent of a matrix obtained from the extended bipartite graph by Yan Huo, and Rasmussen presents a simple approach (RM) to approximate the permanent, which just yields a critical ratio O($n\omega(n)$) for almost all the 0-1 matrices, provided it's a simple promising practical way to compute this #P-complete problem. In this paper, the performance of this method will be shown when it's applied to compute all the matchings based on that transformation. The critical ratio will be proved to be very large with a certain probability, owning an increasing factor larger than any polynomial of $n$ even in the sense for almost all the 0-1 matrices. Hence, RM fails to work well when counting all the matchings via computing the permanent of the matrix. In other words, we must carefully utilize the known methods of estimating the permanent to count all the matchings through that transformation.<|reference_end|> | arxiv | @article{zhang2008an,
title={An analysis of a random algorithm for estimating all the matchings},
author={Jinshan Zhang},
journal={arXiv preprint arXiv:0812.1119},
year={2008},
archivePrefix={arXiv},
eprint={0812.1119},
primaryClass={cs.GR cs.AI}
} | zhang2008an |
arxiv-5663 | 0812.1123 | Improved Approximation for the Number of Hamiltonian Cycles in Dense Digraphs | <|reference_start|>Improved Approximation for the Number of Hamiltonian Cycles in Dense Digraphs: We propose an improved algorithm for counting the number of Hamiltonian cycles in a directed graph. The basic idea of the method is sequential acceptance/rejection, which is successfully used in approximating the number of perfect matchings in dense bipartite graphs. As a consequence, a new bound on the number of Hamiltonian cycles in a directed graph is proved, by using the ratio of the number of 1-factors. Based on this bound, we prove that our algorithm runs in expected time of $O(n^{8.5})$ for dense problems. This improves the Markov chain method, the most powerful existing method, a factor of at least $n^{4.5}(\log n)^{4}$ in running time. This class of dense problems is shown to be nontrivial in counting, in the sense that it is $#$P-Complete.<|reference_end|> | arxiv | @article{zhang2008improved,
title={Improved Approximation for the Number of Hamiltonian Cycles in Dense
Digraphs},
author={Jinshan Zhang},
journal={arXiv preprint arXiv:0812.1123},
year={2008},
archivePrefix={arXiv},
eprint={0812.1123},
primaryClass={cs.DS cs.DM}
} | zhang2008improved |
arxiv-5664 | 0812.1126 | Emerge-Sort: Converging to Ordered Sequences by Simple Local Operators | <|reference_start|>Emerge-Sort: Converging to Ordered Sequences by Simple Local Operators: In this paper we examine sorting on the assumption that we do not know in advance which way to sort a sequence of numbers and we set at work simple local comparison and swap operators whose repeating application ends up in sorted sequences. These are the basic elements of Emerge-Sort, our approach to self-organizing sorting, which we then validate experimentally across a range of samples. Observing an O(n2) run-time behaviour, we note that the n/logn delay coefficient that differentiates Emerge-Sort from the classical comparison based algorithms is an instantiation of the price of anarchy we pay for not imposing a sorting order and for letting that order emerge through the local interactions.<|reference_end|> | arxiv | @article{kalles2008emerge-sort:,
title={Emerge-Sort: Converging to Ordered Sequences by Simple Local Operators},
author={Dimitris Kalles, Alexis Kaporis},
journal={arXiv preprint arXiv:0812.1126},
year={2008},
archivePrefix={arXiv},
eprint={0812.1126},
primaryClass={cs.AI cs.DS}
} | kalles2008emerge-sort: |
arxiv-5665 | 0812.1155 | Complex Agent Networks explaining the HIV epidemic among homosexual men in Amsterdam | <|reference_start|>Complex Agent Networks explaining the HIV epidemic among homosexual men in Amsterdam: Simulating the evolution of the Human Immunodeficiency Virus (HIV) epidemic requires a detailed description of the population network, especially for small populations in which individuals can be represented in detail and accuracy. In this paper, we introduce the concept of a Complex Agent Network(CAN) to model the HIV epidemics by combining agent-based modelling and complex networks, in which agents represent individuals that have sexual interactions. The applicability of CANs is demonstrated by constructing and executing a detailed HIV epidemic model for men who have sex with men (MSM) in Amsterdam, including a distinction between steady and casual relationships. We focus on MSM contacts because they play an important role in HIV epidemics and have been tracked in Amsterdam for a long time. Our experiments show good correspondence between the historical data of the Amsterdam cohort and the simulation results.<|reference_end|> | arxiv | @article{mei2008complex,
title={Complex Agent Networks explaining the HIV epidemic among homosexual men
in Amsterdam},
author={Shan Mei, P.M.A Sloot, Rick Quax, Yifan Zhu, Weiping Wang},
journal={arXiv preprint arXiv:0812.1155},
year={2008},
archivePrefix={arXiv},
eprint={0812.1155},
primaryClass={cs.MA q-bio.PE}
} | mei2008complex |
arxiv-5666 | 0812.1194 | Adversarial Scheduling in Evolutionary Game Dynamics | <|reference_start|>Adversarial Scheduling in Evolutionary Game Dynamics: Consider a system in which players at nodes of an underlying graph G repeatedly play Prisoner's Dilemma against their neighbors. The players adapt their strategies based on the past behavior of their opponents by applying the so-called win-stay lose-shift strategy. This dynamics has been studied in (Kittock 94), (Dyer et al. 2002), (Mossel and Roch, 2006). With random scheduling, starting from any initial configuration with high probability the system reaches the unique fixed point in which all players cooperate. This paper investigates the validity of this result under various classes of adversarial schedulers. Our results can be sumarized as follows: 1. An adversarial scheduler that can select both participants to the game can preclude the system from reaching the unique fixed point on most graph topologies. 2. A nonadaptive scheduler that is only allowed to choose one of the participants is no more powerful than a random scheduler. With this restriction even an adaptive scheduler is not significantly more powerful than the random scheduler, provided it is "reasonably fair". The results exemplify the adversarial scheduling approach we propose as a foundational basis for the generative approach to social science (Epstein 2007).<|reference_end|> | arxiv | @article{istrate2008adversarial,
title={Adversarial Scheduling in Evolutionary Game Dynamics},
author={Gabriel Istrate, Madhav V. Marathe and S. S. Ravi},
journal={arXiv preprint arXiv:0812.1194},
year={2008},
archivePrefix={arXiv},
eprint={0812.1194},
primaryClass={cs.DM cs.GT}
} | istrate2008adversarial |
arxiv-5667 | 0812.1200 | Polynomial hierarchy, Betti numbers and a real analogue of Toda's theorem | <|reference_start|>Polynomial hierarchy, Betti numbers and a real analogue of Toda's theorem: Toda proved in 1989 that the (discrete) polynomial time hierarchy, $\mathbf{PH}$, is contained in the class $\mathbf{P}^{#\mathbf{P}}$, namely the class of languages that can be decided by a Turing machine in polynomial time given access to an oracle with the power to compute a function in the counting complexity class $#\mathbf{P}$. This result which illustrates the power of counting is considered to be a seminal result in computational complexity theory. An analogous result in the complexity theory over the reals (in the sense of Blum-Shub-Smale real machines) has been missing so far. In this paper we formulate and prove a real analogue of Toda's theorem. Unlike Toda's proof in the discrete case, which relied on sophisticated combinatorial arguments, our proof is topological in nature. As a consequence of our techniques we are also able to relate the computational hardness of two extremely well-studied problems in algorithmic semi-algebraic geometry -- namely the problem of deciding sentences in the first order theory of the reals with a constant number of quantifier alternations, and that of computing Betti numbers of semi-algebraic sets. We obtain a polynomial time reduction of the compact version of the first problem to the second. This latter result might be of independent interest to researchers in algorithmic semi-algebraic geometry.<|reference_end|> | arxiv | @article{basu2008polynomial,
title={Polynomial hierarchy, Betti numbers and a real analogue of Toda's
theorem},
author={Saugata Basu and Thierry Zell},
journal={Found. Comput. Math, 10:429-454, 2010},
year={2008},
archivePrefix={arXiv},
eprint={0812.1200},
primaryClass={cs.CC math.AT math.CO math.LO}
} | basu2008polynomial |
arxiv-5668 | 0812.1203 | An Efficient Adaptive Distributed Space-Time Coding Scheme for Cooperative Relaying | <|reference_start|>An Efficient Adaptive Distributed Space-Time Coding Scheme for Cooperative Relaying: A non-regenerative dual-hop wireless system based on a distributed space-time coding strategy is considered. It is assumed that each relay retransmits an appropriately scaled space-time coded version of its received signal. The main goal of this paper is to investigate a power allocation strategy in relay stations, which is based on minimizing the outage probability. In the high signal-to-noise ratio regime for the relay-destination link, it is shown that a threshold-based power allocation scheme (i.e., the relay remains silent if its channel gain with the source is less than a prespecified threshold) is optimum. Monte-Carlo simulations show that the derived on-off power allocation scheme performs close to optimum for finite signal-to-noise ratio values. Numerical results demonstrate a dramatic improvement in system performance as compared to the case that the relay stations forward their received signals with full power. In addition, a hybrid amplify-and-forward/detect-and-forward scheme is proposed for the case that the quality of the source-relay link is good. Finally, the robustness of the proposed scheme in the presence of channel estimation errors is numerically evaluated.<|reference_end|> | arxiv | @article{abouei2008an,
title={An Efficient Adaptive Distributed Space-Time Coding Scheme for
Cooperative Relaying},
author={Jamshid Abouei, Hossein Bagheri, and Amir K. Khandani},
journal={IEEE Transactions on Wireless Communications, vol. 8, no. 10, pp.
4957-4962, Oct. 2009},
year={2008},
doi={10.1109/TWC.2009.081615},
archivePrefix={arXiv},
eprint={0812.1203},
primaryClass={cs.IT math.IT}
} | abouei2008an |
arxiv-5669 | 0812.1218 | The Impact of New Technologies in Public Financial Management and Performance: Agenda for Public Financial Management Reformance in the Context of Global Best Practices | <|reference_start|>The Impact of New Technologies in Public Financial Management and Performance: Agenda for Public Financial Management Reformance in the Context of Global Best Practices: Information and Communication Technologies (ICT) has practically penetrated into all spheres of life. Therefore a closer look at the impact of ICT in public financial management and performance is highly justified. Public finance is defined as a field of economics concerned with paying for collective or governmental activities, and with the administration and design of those activities. Activities will be viewed as services or more precisely as public services. We believe that there is need to consider performance from the perspective of effective performance and the perceived performance. In fact the real or effective performance might not correspond to the perceived performance. A service can be considered from the perspective of the decision-maker, who in our case could be a government or a collectivity. ICT can be employed in the three phases that concern the decision-maker: design, implementation and evaluation. The beneficiaries of a service can employ ICT in any of the three phases - awareness, exploitation and assessment - for guarantying a high level of efficiency. Each phase in the environment of a service will be presented as well as illustrations of how ICT can be employed in order to improve the end-result of each one of them. We believe that a high efficiency of each phase will produce a high global efficiency. It should be noted however that the effectiveness of any system is highly dependent on the human engagement in the system. Therefore, the impact of ICT in public financial management will be felt only if the decision-makers and the end-users of the services engage themselves in the success of the system. Instead of giving a catalog of services, the focus has been on the model (or methodology) to adopt in designing services for which ICT could enhance the implementation.<|reference_end|> | arxiv | @article{david2008the,
title={The Impact of New Technologies in Public Financial Management and
Performance: Agenda for Public Financial Management Reformance in the Context
of Global Best Practices},
author={Amos David (LORIA)},
journal={6th Nigeria Development Forum Retreat (2008)},
year={2008},
archivePrefix={arXiv},
eprint={0812.1218},
primaryClass={cs.OH}
} | david2008the |
arxiv-5670 | 0812.1244 | Decomposition Principles and Online Learning in Cross-Layer Optimization for Delay-Sensitive Applications | <|reference_start|>Decomposition Principles and Online Learning in Cross-Layer Optimization for Delay-Sensitive Applications: In this paper, we propose a general cross-layer optimization framework in which we explicitly consider both the heterogeneous and dynamically changing characteristics of delay-sensitive applications and the underlying time-varying network conditions. We consider both the independently decodable data units (DUs, e.g. packets) and the interdependent DUs whose dependencies are captured by a directed acyclic graph (DAG). We first formulate the cross-layer design as a non-linear constrained optimization problem by assuming complete knowledge of the application characteristics and the underlying network conditions. The constrained cross-layer optimization is decomposed into several cross-layer optimization subproblems for each DU and two master problems. The proposed decomposition method determines the necessary message exchanges between layers for achieving the optimal cross-layer solution. However, the attributes (e.g. distortion impact, delay deadline etc) of future DUs as well as the network conditions are often unknown in the considered real-time applications. The impact of current cross-layer actions on the future DUs can be characterized by a state-value function in the Markov decision process (MDP) framework. Based on the dynamic programming solution to the MDP, we develop a low-complexity cross-layer optimization algorithm using online learning for each DU transmission. This online algorithm can be implemented in real-time in order to cope with unknown source characteristics, network dynamics and resource constraints. Our numerical results demonstrate the efficiency of the proposed online algorithm.<|reference_end|> | arxiv | @article{fu2008decomposition,
title={Decomposition Principles and Online Learning in Cross-Layer Optimization
for Delay-Sensitive Applications},
author={Fangwen Fu, Mihaela van der Schaar},
journal={arXiv preprint arXiv:0812.1244},
year={2008},
archivePrefix={arXiv},
eprint={0812.1244},
primaryClass={cs.MM cs.LG}
} | fu2008decomposition |
arxiv-5671 | 0812.1291 | Unary finite automata vs arithmetic progressions | <|reference_start|>Unary finite automata vs arithmetic progressions: We point out a subtle error in the proof of Chrobak's theorem that every unary NFA can be represented as a union of arithmetic progressions that is at most quadratically large. We propose a correction for this and show how Martinez's polynomial time algorithm, which realizes Chrobak's theorem, can be made correct accordingly. We also show that Martinez's algorithm cannot be improved to have logarithmic space, unless L = NL.<|reference_end|> | arxiv | @article{to2008unary,
title={Unary finite automata vs. arithmetic progressions},
author={Anthony Widjaja To},
journal={arXiv preprint arXiv:0812.1291},
year={2008},
archivePrefix={arXiv},
eprint={0812.1291},
primaryClass={cs.CC cs.LO}
} | to2008unary |
arxiv-5672 | 0812.1321 | Oscillations with TCP-like Flow Control in Networks of Queues | <|reference_start|>Oscillations with TCP-like Flow Control in Networks of Queues: We consider a set of flows passing through a set of servers. The injection rate into each flow is governed by a flow control that increases the injection rate when all the servers on the flow's path are empty and decreases the injection rate when some server is congested. We show that if each server's congestion is governed by the arriving traffic at the server then the system can *oscillate*. This is in contrast to previous work on flow control where congestion was modeled as a function of the flow injection rates and the system was shown to converge to a steady state that maximizes an overall network utility.<|reference_end|> | arxiv | @article{andrews2008oscillations,
title={Oscillations with TCP-like Flow Control in Networks of Queues},
author={Matthew Andrews and Aleksandrs Slivkins},
journal={arXiv preprint arXiv:0812.1321},
year={2008},
archivePrefix={arXiv},
eprint={0812.1321},
primaryClass={cs.NI cs.DS}
} | andrews2008oscillations |
arxiv-5673 | 0812.1340 | Obtaining Depth Maps From Color Images By Region Based Stereo Matching Algorithms | <|reference_start|>Obtaining Depth Maps From Color Images By Region Based Stereo Matching Algorithms: In the paper, region based stereo matching algorithms are developed for extraction depth information from two color stereo image pair. A filter eliminating unreliable disparity estimation was used for increasing reliability of the disparity map. Obtained results by algorithms were represented and compared.<|reference_end|> | arxiv | @article{alagoz2008obtaining,
title={Obtaining Depth Maps From Color Images By Region Based Stereo Matching
Algorithms},
author={B. Baykant Alagoz},
journal={OncuBilim Algorithm And Systems Labs. Vol.08, Art.No:04,(2008)},
year={2008},
archivePrefix={arXiv},
eprint={0812.1340},
primaryClass={cs.CV}
} | alagoz2008obtaining |
arxiv-5674 | 0812.1357 | A Novel Clustering Algorithm Based on Quantum Random Walk | <|reference_start|>A Novel Clustering Algorithm Based on Quantum Random Walk: The enormous successes have been made by quantum algorithms during the last decade. In this paper, we combine the quantum random walk (QRW) with the problem of data clustering, and develop two clustering algorithms based on the one dimensional QRW. Then, the probability distributions on the positions induced by QRW in these algorithms are investigated, which also indicates the possibility of obtaining better results. Consequently, the experimental results have demonstrated that data points in datasets are clustered reasonably and efficiently, and the clustering algorithms are of fast rates of convergence. Moreover, the comparison with other algorithms also provides an indication of the effectiveness of the proposed approach.<|reference_end|> | arxiv | @article{li2008a,
title={A Novel Clustering Algorithm Based on Quantum Random Walk},
author={Qiang Li, Yan He, Jing-ping Jiang},
journal={arXiv preprint arXiv:0812.1357},
year={2008},
archivePrefix={arXiv},
eprint={0812.1357},
primaryClass={cs.LG}
} | li2008a |
arxiv-5675 | 0812.1364 | Graph Polynomials: From Recursive Definitions To Subset Expansion Formulas | <|reference_start|>Graph Polynomials: From Recursive Definitions To Subset Expansion Formulas: Many graph polynomials, such as the Tutte polynomial, the interlace polynomial and the matching polynomial, have both a recursive definition and a defining subset expansion formula. In this paper we present a general, logic-based framework which gives a precise meaning to recursive definitions of graph polynomials. We then prove that in this framework every recursive definition of a graph polynomial can be converted into a subset expansion formula.<|reference_end|> | arxiv | @article{godlin2008graph,
title={Graph Polynomials: From Recursive Definitions To Subset Expansion
Formulas},
author={Benny Godlin, Emilia Katz, Johann A. Makowsky},
journal={Journal of Logic and Computation, Volume 22(2), (2012) Pages
237-265},
year={2008},
archivePrefix={arXiv},
eprint={0812.1364},
primaryClass={cs.LO cs.DM}
} | godlin2008graph |
arxiv-5676 | 0812.1379 | Distributed (Delta + 1)-coloring in linear (in Delta) time | <|reference_start|>Distributed (Delta + 1)-coloring in linear (in Delta) time: The distributed (Delta + 1)-coloring problem is one of most fundamental and well-studied problems of Distributed Algorithms. Starting with the work of Cole and Vishkin in 86, there was a long line of gradually improving algorithms published. The current state-of-the-art running time is O(Delta log Delta + log^* n), due to Kuhn and Wattenhofer, PODC'06. Linial (FOCS'87) has proved a lower bound of 1/2 \log^* n for the problem, and Szegedy and Vishwanathan (STOC'93) provided a heuristic argument that shows that algorithms from a wide family of locally iterative algorithms are unlikely to achieve running time smaller than \Theta(Delta log Delta). We present a deterministic (Delta + 1)-coloring distributed algorithm with running time O(Delta) + 1/2 log^* n. We also present a tradeoff between the running time and the number of colors, and devise an O(Delta * t)-coloring algorithm with running time O(Delta / t + \log^* n), for any parameter t, 1 < t < Delta^{1-epsilon}, for an arbitrarily small constant epsilon, 0 < epsilon < 1. On the way to this result we study a generalization of the notion of graph coloring, which is called defective coloring. In an m-defective p-coloring the vertices are colored with p colors so that each vertex has up to m neighbors with the same color. We show that an m-defective p-coloring with reasonably small m and p can be computed very efficiently. We also develop a technique to employ multiple defect colorings of various subgraphs of the original graph G for computing a (Delta+1)-coloring of G. We believe that these techniques are of independent interest.<|reference_end|> | arxiv | @article{barenboim2008distributed,
title={Distributed (Delta + 1)-coloring in linear (in Delta) time},
author={Leonid Barenboim and Michael Elkin},
journal={arXiv preprint arXiv:0812.1379},
year={2008},
archivePrefix={arXiv},
eprint={0812.1379},
primaryClass={cs.DC cs.NI}
} | barenboim2008distributed |
arxiv-5677 | 0812.1385 | An Extension of the Permutation Group Enumeration Technique (Collapse of the Polynomial Hierarchy: $\mathbfNP = P$) | <|reference_start|>An Extension of the Permutation Group Enumeration Technique (Collapse of the Polynomial Hierarchy: $\mathbfNP = P$): The distinguishing result of this paper is a $\mathbf{P}$-time enumerable partition of all the potential perfect matchings in a bipartite graph. This partition is a set of equivalence classes induced by the missing edges in the potential perfect matchings. We capture the behavior of these missing edges in a polynomially bounded representation of the exponentially many perfect matchings by a graph theoretic structure, called MinSet Sequence, where MinSet is a P-time enumerable structure derived from a graph theoretic counterpart of a generating set of the symmetric group. This leads to a polynomially bounded generating set of all the classes, enabling the enumeration of perfect matchings in polynomial time. The sequential time complexity of this $\mathbf{\#P}$-complete problem is shown to be $O(n^{45}\log n)$. And thus we prove a result even more surprising than $\mathbf{NP = P}$, that is, $\mathbf{\#P}=\mathbf{FP}$, where $\mathbf{FP}$ is the class of functions, $f: \{0, 1\}^* \rightarrow \mathbb{N} $, computable in polynomial time on a deterministic model of computation.<|reference_end|> | arxiv | @article{aslam2008an,
title={An Extension of the Permutation Group Enumeration Technique (Collapse of
the Polynomial Hierarchy: $\mathbf{NP = P}$)},
author={Javaid Aslam},
journal={arXiv preprint arXiv:0812.1385},
year={2008},
archivePrefix={arXiv},
eprint={0812.1385},
primaryClass={cs.CC cs.DS}
} | aslam2008an |
arxiv-5678 | 0812.1390 | Stability of Curvature Measures | <|reference_start|>Stability of Curvature Measures: We address the problem of curvature estimation from sampled compact sets. The main contribution is a stability result: we show that the gaussian, mean or anisotropic curvature measures of the offset of a compact set K with positive $\mu$-reach can be estimated by the same curvature measures of the offset of a compact set K' close to K in the Hausdorff sense. We show how these curvature measures can be computed for finite unions of balls. The curvature measures of the offset of a compact set with positive $\mu$-reach can thus be approximated by the curvature measures of the offset of a point-cloud sample. These results can also be interpreted as a framework for an effective and robust notion of curvature.<|reference_end|> | arxiv | @article{chazal2008stability,
title={Stability of Curvature Measures},
author={Fr'ed'eric Chazal (INRIA Sophia Antipolis, INRIA Sophia Antipolis /
INRIA Futurs), David Cohen-Steiner (INRIA Sophia Antipolis, INRIA Sophia
Antipolis / INRIA Futurs), Andr'e Lieutier (LJK), Boris Thibert (LJK, LMC -
IMAG)},
journal={arXiv preprint arXiv:0812.1390},
year={2008},
number={RR-6756},
archivePrefix={arXiv},
eprint={0812.1390},
primaryClass={cs.CG math.DG}
} | chazal2008stability |
arxiv-5679 | 0812.1394 | Conceptual approach through an annotation process for the representation and the information contents enhancement in economic intelligence (EI) | <|reference_start|>Conceptual approach through an annotation process for the representation and the information contents enhancement in economic intelligence (EI): In the era of the information society, the impact of the information systems on the economy of material and immaterial is certainly perceptible. With regards to the information resources of an organization, the annotation involved to enrich informational content, to track the intellectual activities on a document and to set the added value on information for the benefit of solving a decision-making problem in the context of economic intelligence. Our contribution is distinguished by the representation of an annotation process and its inherent concepts to lead the decisionmaker to an anticipated decision: the provision of relevant and annotated information. Such information in the system is made easy by taking into account the diversity of resources and those that are well annotated so formally and informally by the EI actors. A capital research framework consist of integrating in the decision-making process the annotator activity, the software agent (or the reasoning mechanisms) and the information resources enhancement.<|reference_end|> | arxiv | @article{sidhom2008conceptual,
title={Conceptual approach through an annotation process for the representation
and the information contents enhancement in economic intelligence (EI)},
author={Sahbi Sidhom (LORIA, Sii)},
journal={Journal of Global Management Research (2008) 15 pages},
year={2008},
archivePrefix={arXiv},
eprint={0812.1394},
primaryClass={cs.IR}
} | sidhom2008conceptual |
arxiv-5680 | 0812.1405 | Cognitive Coexistence between Infrastructure and Ad-hoc Systems | <|reference_start|>Cognitive Coexistence between Infrastructure and Ad-hoc Systems: The rapid proliferation of wireless systems makes interference management more and more important. This paper presents a novel cognitive coexistence framework, which enables an infrastructure system to reduce interference to ad-hoc or peer-to-peer communication links in close proximity. Motivated by the superior resources of the infrastructure system, we study how its centralized resource allocation can accommodate the ad-hoc links based on sensing and predicting their interference patterns. Based on an ON/OFF continuous-time Markov chain model, the optimal allocation of power and transmission time is formulated as a convex optimization problem and closed-form solutions are derived. The optimal scheduling is extended to the case where the infrastructure channel is random and rate constraints need only be met in the long-term average. Finally, the multi-terminal case is addressed and the problem of optimal sub-channel allocation discussed. Numerical performance analysis illustrates that utilizing the superior flexibility of the infrastructure links can effectively mitigate interference.<|reference_end|> | arxiv | @article{geirhofer2008cognitive,
title={Cognitive Coexistence between Infrastructure and Ad-hoc Systems},
author={Stefan Geirhofer, Lang Tong, and Brian M. Sadler},
journal={arXiv preprint arXiv:0812.1405},
year={2008},
archivePrefix={arXiv},
eprint={0812.1405},
primaryClass={cs.IT math.IT}
} | geirhofer2008cognitive |
arxiv-5681 | 0812.1462 | Logic programs with propositional connectives and aggregates | <|reference_start|>Logic programs with propositional connectives and aggregates: Answer set programming (ASP) is a logic programming paradigm that can be used to solve complex combinatorial search problems. Aggregates are an ASP construct that plays an important role in many applications. Defining a satisfactory semantics of aggregates turned out to be a difficult problem, and in this paper we propose a new approach, based on an analogy between aggregates and propositional connectives. First, we extend the definition of an answer set/stable model to cover arbitrary propositional theories; then we define aggregates on top of them both as primitive constructs and as abbreviations for formulas. Our definition of an aggregate combines expressiveness and simplicity, and it inherits many theorems about programs with nested expressions, such as theorems about strong equivalence and splitting.<|reference_end|> | arxiv | @article{ferraris2008logic,
title={Logic programs with propositional connectives and aggregates},
author={Paolo Ferraris},
journal={arXiv preprint arXiv:0812.1462},
year={2008},
archivePrefix={arXiv},
eprint={0812.1462},
primaryClass={cs.AI}
} | ferraris2008logic |
arxiv-5682 | 0812.1553 | Analysis of Energy Efficiency in Fading Channels under QoS Constraints | <|reference_start|>Analysis of Energy Efficiency in Fading Channels under QoS Constraints: Energy efficiency in fading channels in the presence of Quality of Service (QoS) constraints is studied. Effective capacity, which provides the maximum arrival rate that a wireless channel can sustain while satisfying statistical QoS constraints, is considered. Spectral efficiency--bit energy tradeoff is analyzed in the low-power and wideband regimes by employing the effective capacity formulation, rather than the Shannon capacity. Through this analysis, energy requirements under QoS constraints are identified. The analysis is conducted under two assumptions: perfect channel side information (CSI) available only at the receiver and perfect CSI available at both the receiver and transmitter. In particular, it is shown in the low-power regime that the minimum bit energy required under QoS constraints is the same as that attained when there are no such limitations. However, this performance is achieved as the transmitted power vanishes. Through the wideband slope analysis, the increased energy requirements at low but nonzero power levels in the presence of QoS constraints are determined. A similar analysis is also conducted in the wideband regime, and minimum bit energy and wideband slope expressions are obtained. In this regime, the required bit energy levels are found to be strictly greater than those achieved when Shannon capacity is considered. Overall, a characterization of the energy-bandwidth-delay tradeoff is provided.<|reference_end|> | arxiv | @article{gursoy2008analysis,
title={Analysis of Energy Efficiency in Fading Channels under QoS Constraints},
author={Mustafa Cenk Gursoy, Deli Qiao, and Senem Velipasalar},
journal={arXiv preprint arXiv:0812.1553},
year={2008},
archivePrefix={arXiv},
eprint={0812.1553},
primaryClass={cs.IT math.IT}
} | gursoy2008analysis |
arxiv-5683 | 0812.1554 | Molecular communication: Physically realistic models and achievable information rates | <|reference_start|>Molecular communication: Physically realistic models and achievable information rates: Molecular communication is a biologically-inspired method of communication with attractive properties for microscale and nanoscale devices. In molecular communication, messages are transmitted by releasing a pattern of molecules at a transmitter, which propagate through a fluid medium towards a receiver. In this paper, molecular communication is formulated as a mathematical communication problem in an information-theoretic context. Physically realistic models are obtained, with sufficient abstraction to allow manipulation by communication and information theorists. Although mutual information in these channels is intractable, we give sequences of upper and lower bounds on the mutual information which trade off complexity and performance, and present results to illustrate the feasibility of these bounds in estimating the true mutual information.<|reference_end|> | arxiv | @article{eckford2008molecular,
title={Molecular communication: Physically realistic models and achievable
information rates},
author={Andrew W. Eckford},
journal={arXiv preprint arXiv:0812.1554},
year={2008},
archivePrefix={arXiv},
eprint={0812.1554},
primaryClass={cs.IT math.IT}
} | eckford2008molecular |
arxiv-5684 | 0812.1557 | To Cooperate, or Not to Cooperate in Imperfectly-Known Fading Channels | <|reference_start|>To Cooperate, or Not to Cooperate in Imperfectly-Known Fading Channels: In this paper, communication over imperfectly-known fading channels with different degrees of cooperation is studied. The three-node relay channel is considered. It is assumed that communication starts with the network training phase in which the receivers estimate the fading coefficients of their respective channels. In the data transmission phase, amplify-and-forward and decode-and-forward relaying schemes are employed. For different cooperation protocols, achievable rate expressions are obtained. These achievable rate expressions are then used to find the optimal resource allocation strategies. In particular, the fraction of total time or bandwidth that needs to be allocated to the relay for best performance is identified. Under a total power constraint, optimal allocation of power between the source and relay is investigated. Finally, bit energy requirements in the low-power regime are studied.<|reference_end|> | arxiv | @article{zhang2008to,
title={To Cooperate, or Not to Cooperate in Imperfectly-Known Fading Channels},
author={Junwei Zhang and Mustafa Cenk Gursoy},
journal={arXiv preprint arXiv:0812.1557},
year={2008},
archivePrefix={arXiv},
eprint={0812.1557},
primaryClass={cs.IT math.IT}
} | zhang2008to |
arxiv-5685 | 0812.1558 | Pilot-Symbol-Assisted Communications with Noncausal and Causal Wiener Filters | <|reference_start|>Pilot-Symbol-Assisted Communications with Noncausal and Causal Wiener Filters: In this paper, pilot-assisted transmission over time-selective flat fading channels is studied. It is assumed that noncausal and causal Wiener filters are employed at the receiver to perform channel estimation with the aid of training symbols sent periodically by the transmitter. For both filters, the variances of estimate errors are obtained from the Doppler power spectrum of the channel. Subsequently, achievable rate expressions are provided. The training period, and data and training power allocations are jointly optimized by maximizing the achievable rate expressions. Numerical results are obtained by modeling the fading as a Gauss-Markov process. The achievable rates of causal and noncausal filtering approaches are compared. For the particular ranges of parameters considered in the paper, the performance loss incurred by using a causal filter as opposed to a noncausal filter is shown to be small. The impact of aliasing that occurs in the undersampled version of the channel Doppler spectrum due to fast fading is analyzed. Finally, energy-per-bit requirements are investigated in the presence of noncausal and causal Wiener filters.<|reference_end|> | arxiv | @article{akin2008pilot-symbol-assisted,
title={Pilot-Symbol-Assisted Communications with Noncausal and Causal Wiener
Filters},
author={Sami Akin and Mustafa Cenk Gursoy},
journal={arXiv preprint arXiv:0812.1558},
year={2008},
archivePrefix={arXiv},
eprint={0812.1558},
primaryClass={cs.IT math.IT}
} | akin2008pilot-symbol-assisted |
arxiv-5686 | 0812.1560 | Achievable Rates and Training Optimization for Fading Relay Channels with Memory | <|reference_start|>Achievable Rates and Training Optimization for Fading Relay Channels with Memory: In this paper, transmission over time-selective, flat fading relay channels is studied. It is assumed that channel fading coefficients are not known a priori. Transmission takes place in two phases: network training phase and data transmission phase. In the training phase, pilot symbols are sent and the receivers employ single-pilot MMSE estimation or noncausal Wiener filter to learn the channel. Amplify-and-Forward (AF) and Decode-and-Forward (DF) techniques are considered in the data transmission phase and achievable rate expressions are obtained. The training period, and data and training power allocations are jointly optimized by using the achievable rate expressions. Numerical results are obtained considering Gauss-Markov and lowpass fading models. Achievable rates are computed and energy-per-bit requirements are investigated. The optimal power distributions among pilot and data symbols are provided.<|reference_end|> | arxiv | @article{akin2008achievable,
title={Achievable Rates and Training Optimization for Fading Relay Channels
with Memory},
author={Sami Akin and Mustafa Cenk Gursoy},
journal={arXiv preprint arXiv:0812.1560},
year={2008},
archivePrefix={arXiv},
eprint={0812.1560},
primaryClass={cs.IT math.IT}
} | akin2008achievable |
arxiv-5687 | 0812.1587 | Fast phylogeny reconstruction through learning of ancestral sequences | <|reference_start|>Fast phylogeny reconstruction through learning of ancestral sequences: Given natural limitations on the length DNA sequences, designing phylogenetic reconstruction methods which are reliable under limited information is a crucial endeavor. There have been two approaches to this problem: reconstructing partial but reliable information about the tree (\cite{Mo07, DMR08,DHJ06,GMS08}), and reaching "deeper" in the tree through reconstruction of ancestral sequences. In the latter category, \cite{DMR06} settled an important conjecture of M.Steel, showing that, under the CFN model of evolution, all trees on $n$ leaves with edge lengths bounded by the Ising model phase transition can be recovered with high probability from genomes of length $O(\log n)$ with a polynomial time algorithm. Their methods had a running time of $O(n^{10})$. Here we enhance our methods from \cite{DHJ06} with the learning of ancestral sequences and provide an algorithm for reconstructing a sub-forest of the tree which is reliable given available data, without requiring a-priori known bounds on the edge lengths of the tree. Our methods are based on an intuitive minimum spanning tree approach and run in $O(n^3)$ time. For the case of full reconstruction of trees with edges under the phase transition, we maintain the same sequence length requirements as \cite{DMR06}, despite the considerably faster running time.<|reference_end|> | arxiv | @article{mihaescu2008fast,
title={Fast phylogeny reconstruction through learning of ancestral sequences},
author={Radu Mihaescu, Cameron Hill, Satish Rao},
journal={arXiv preprint arXiv:0812.1587},
year={2008},
archivePrefix={arXiv},
eprint={0812.1587},
primaryClass={cs.DS cs.DM}
} | mihaescu2008fast |
arxiv-5688 | 0812.1595 | A quasi-polynomial time approximation scheme for Euclidean capacitated vehicle routing | <|reference_start|>A quasi-polynomial time approximation scheme for Euclidean capacitated vehicle routing: In the capacitated vehicle routing problem, introduced by Dantzig and Ramser in 1959, we are given the locations of n customers and a depot, along with a vehicle of capacity k, and wish to find a minimum length collection of tours, each starting from the depot and visiting at most k customers, whose union covers all the customers. We give a quasi-polynomial time approximation scheme for the setting where the customers and the depot are on the plane, and distances are given by the Euclidean metric.<|reference_end|> | arxiv | @article{das2008a,
title={A quasi-polynomial time approximation scheme for Euclidean capacitated
vehicle routing},
author={Aparna Das, Claire Mathieu},
journal={arXiv preprint arXiv:0812.1595},
year={2008},
archivePrefix={arXiv},
eprint={0812.1595},
primaryClass={cs.DM cs.DS}
} | das2008a |
arxiv-5689 | 0812.1597 | Transmission Techniques for Relay-Interference Networks | <|reference_start|>Transmission Techniques for Relay-Interference Networks: In this paper we study the relay-interference wireless network, in which relay (helper) nodes are to facilitate competing information flows over a wireless network. We examine this in the context of a deterministic wireless interaction model, which eliminates the channel noise and focuses on the signal interactions. Using this model, we show that almost all the known schemes such as interference suppression, interference alignment and interference separation are necessary for relay-interference networks. In addition, we discover a new interference management technique, which we call interference neutralization, which allows for over-the-air interference removal, without the transmitters having complete access the interfering signals. We show that interference separation, suppression, and neutralization arise in a fundamental manner, since we show complete characterizations for special configurations of the relay-interference network.<|reference_end|> | arxiv | @article{mohajer2008transmission,
title={Transmission Techniques for Relay-Interference Networks},
author={Soheil Mohajer, Suhas N. Diggavi, Christina Fragouli, David N. C. Tse},
journal={arXiv preprint arXiv:0812.1597},
year={2008},
archivePrefix={arXiv},
eprint={0812.1597},
primaryClass={cs.IT math.IT}
} | mohajer2008transmission |
arxiv-5690 | 0812.1599 | Multi-Agent Reinforcement Learning and Genetic Policy Sharing | <|reference_start|>Multi-Agent Reinforcement Learning and Genetic Policy Sharing: The effects of policy sharing between agents in a multi-agent dynamical system has not been studied extensively. I simulate a system of agents optimizing the same task using reinforcement learning, to study the effects of different population densities and policy sharing. I demonstrate that sharing policies decreases the time to reach asymptotic behavior, and results in improved asymptotic behavior.<|reference_end|> | arxiv | @article{ellowitz2008multi-agent,
title={Multi-Agent Reinforcement Learning and Genetic Policy Sharing},
author={Jake Ellowitz},
journal={arXiv preprint arXiv:0812.1599},
year={2008},
archivePrefix={arXiv},
eprint={0812.1599},
primaryClass={cs.MA cs.AI}
} | ellowitz2008multi-agent |
arxiv-5691 | 0812.1601 | Scarf is Ppad-Complete | <|reference_start|>Scarf is Ppad-Complete: Scarf's lemma is one of the fundamental results in combinatorics, originally introduced to study the core of an N-person game. Over the last four decades, the usefulness of Scarf's lemma has been demonstrated in several important combinatorial problems seeking "stable" solutions. However, the complexity of the computational version of Scarf's lemma (SCARF) remained open. In this paper, we prove that SCARF is complete for the complexity class PPAD. This proves that SCARF is as hard as the computational versions of Brouwer's fixed point theorem and Sperner's lemma. Hence, there is no polynomial-time algorithm for SCARF unless PPAD \subseteq P. We also show that fractional stable paths problem and finding strong fractional kernels in digraphs are PPAD-hard.<|reference_end|> | arxiv | @article{kintali2008scarf,
title={Scarf is Ppad-Complete},
author={Shiva Kintali},
journal={arXiv preprint arXiv:0812.1601},
year={2008},
archivePrefix={arXiv},
eprint={0812.1601},
primaryClass={cs.CC}
} | kintali2008scarf |
arxiv-5692 | 0812.1628 | Two Dimensional Connectivity for Vehicular Ad-Hoc Networks | <|reference_start|>Two Dimensional Connectivity for Vehicular Ad-Hoc Networks: In this paper, we focus on two-dimensional connectivity in sparse vehicular ad hoc networks (VANETs). In this respect, we find thresholds for the arrival rates of vehicles at entrances of a block of streets such that the connectivity is guaranteed for any desired probability. To this end, we exploit a mobility model recently proposed for sparse VANETs, based on BCMP open queuing networks and solve the related traffic equations to find the traffic characteristics of each street and use the results to compute the exact probability of connectivity along these streets. Then, we use the results from percolation theory and the proposed fast algorithms for evaluation of bond percolation problem in a random graph corresponding to the block of the streets. We then find sufficiently accurate two dimensional connectivity-related parameters, such as the average number of intersections connected to each other and the size of the largest set of inter-connected intersections. We have also proposed lower bounds for the case of heterogeneous network with two transmission ranges. In the last part of the paper, we apply our method to several numerical examples and confirm our results by simulations.<|reference_end|> | arxiv | @article{farivar2008two,
title={Two Dimensional Connectivity for Vehicular Ad-Hoc Networks},
author={Masoud Farivar, Behzad Mehrdad, Farid Ashtiani},
journal={arXiv preprint arXiv:0812.1628},
year={2008},
archivePrefix={arXiv},
eprint={0812.1628},
primaryClass={cs.NI cs.DS}
} | farivar2008two |
arxiv-5693 | 0812.1629 | An application of the O'Nan-Scott theorem to the group generated by the round functions of an AES-like cipher | <|reference_start|>An application of the O'Nan-Scott theorem to the group generated by the round functions of an AES-like cipher: In a previous paper, we had proved that the permutation group generated by the round functions of an AES-like cipher is primitive. Here we apply the O'Nan Scott classification of primitive groups to prove that this group is the alternating group.<|reference_end|> | arxiv | @article{caranti2008an,
title={An application of the O'Nan-Scott theorem to the group generated by the
round functions of an AES-like cipher},
author={A. Caranti, F. Dalla Volta, M. Sala},
journal={Design, Codes and Cryptography, 2009, vol. 52, p. 293-301},
year={2008},
archivePrefix={arXiv},
eprint={0812.1629},
primaryClass={math.GR cs.IT math.IT}
} | caranti2008an |
arxiv-5694 | 0812.1633 | A simple asynchronous replica-exchange implementation | <|reference_start|>A simple asynchronous replica-exchange implementation: We discuss the possibility of implementing asynchronous replica-exchange (or parallel tempering) molecular dynamics. In our scheme, the exchange attempts are driven by asynchronous messages sent by one of the computing nodes, so that different replicas are allowed to perform a different number of time-steps between subsequent attempts. The implementation is simple and based on the message-passing interface (MPI). We illustrate the advantages of our scheme with respect to the standard synchronous algorithm and we benchmark it for a model Lennard-Jones liquid on an IBM-LS21 blade center cluster.<|reference_end|> | arxiv | @article{bussi2008a,
title={A simple asynchronous replica-exchange implementation},
author={Giovanni Bussi},
journal={G. Bussi, Nuovo Cimento Soc. Ital. Fis., C 32, 61 (2009)},
year={2008},
doi={10.1393/ncc/i2009-10369-8},
archivePrefix={arXiv},
eprint={0812.1633},
primaryClass={physics.comp-ph cs.DC}
} | bussi2008a |
arxiv-5695 | 0812.1647 | Polyomino-Based Digital Halftoning | <|reference_start|>Polyomino-Based Digital Halftoning: In this work, we present a new method for generating a threshold structure. This kind of structure can be advantageously used in various halftoning algorithms such as clustered-dot or dispersed-dot dithering, error diffusion with threshold modulation, etc. The proposed method is based on rectifiable polyominoes -- a non-periodic hierarchical structure, which tiles the Euclidean plane with no gaps. Each polyomino contains a fixed number of discrete threshold values. Thanks to its inherent non-periodic nature combined with off-line optimization of threshold values, our polyomino-based threshold structure shows blue-noise spectral properties. The halftone images produced with this threshold structure have high visual quality. Although the proposed method is general, and can be applied on any polyomino tiling, we consider one particular case: tiling with G-hexominoes. We compare our polyomino-based threshold structure with the best known state-of-the-art methods for generation threshold matrices, and conclude considerable improvement achieved with our method.<|reference_end|> | arxiv | @article{vanderhaeghe2008polyomino-based,
title={Polyomino-Based Digital Halftoning},
author={David Vanderhaeghe (INRIA Rh^one-Alpes / LJK Laboratoire Jean
Kuntzmann, LJK), Victor Ostromoukhov (DIRO)},
journal={IADIS International Conference on Computer Graphics and
Visualization 2008 (2008)},
year={2008},
archivePrefix={arXiv},
eprint={0812.1647},
primaryClass={cs.GR}
} | vanderhaeghe2008polyomino-based |
arxiv-5696 | 0812.1713 | Secret Communication with Feedback | <|reference_start|>Secret Communication with Feedback: Secure communication with feedback is studied. An achievability scheme in which the backward channel is used to generate a shared secret key is proposed. The scenario of binary symmetric forward and backward channels is considered, and a combination of the proposed scheme and Maurer's coding scheme is shown to achieve improved secrecy rates. The scenario of a Gaussian channel with perfect output feedback is also analyzed and the Schalkwijk-Kailath coding scheme is shown to achieve the secrecy capacity for this channel.<|reference_end|> | arxiv | @article{gunduz2008secret,
title={Secret Communication with Feedback},
author={Deniz Gunduz, D. Richard Brown III, H. Vincent Poor},
journal={arXiv preprint arXiv:0812.1713},
year={2008},
doi={10.1109/ISITA.2008.4895417},
archivePrefix={arXiv},
eprint={0812.1713},
primaryClass={cs.IT math.IT}
} | gunduz2008secret |
arxiv-5697 | 0812.1729 | The Wadge Hierarchy of Deterministic Tree Languages | <|reference_start|>The Wadge Hierarchy of Deterministic Tree Languages: We provide a complete description of the Wadge hierarchy for deterministically recognisable sets of infinite trees. In particular we give an elementary procedure to decide if one deterministic tree language is continuously reducible to another. This extends Wagner's results on the hierarchy of omega-regular languages of words to the case of trees.<|reference_end|> | arxiv | @article{murlak2008the,
title={The Wadge Hierarchy of Deterministic Tree Languages},
author={Filip Murlak},
journal={Logical Methods in Computer Science, Volume 4, Issue 4 (December
23, 2008) lmcs:994},
year={2008},
doi={10.2168/LMCS-4(4:15)2008},
archivePrefix={arXiv},
eprint={0812.1729},
primaryClass={cs.LO}
} | murlak2008the |
arxiv-5698 | 0812.1778 | The Impact of QoS Constraints on the Energy Efficiency of Fixed-Rate Wireless Transmissions | <|reference_start|>The Impact of QoS Constraints on the Energy Efficiency of Fixed-Rate Wireless Transmissions: Transmission over wireless fading channels under quality of service (QoS) constraints is studied when only the receiver has channel side information. Being unaware of the channel conditions, transmitter is assumed to send the information at a fixed rate. Under these assumptions, a two-state (ON-OFF) transmission model is adopted, where information is transmitted reliably at a fixed rate in the ON state while no reliable transmission occurs in the OFF state. QoS limitations are imposed as constraints on buffer violation probabilities, and effective capacity formulation is used to identify the maximum throughput that a wireless channel can sustain while satisfying statistical QoS constraints. Energy efficiency is investigated by obtaining the bit energy required at zero spectral efficiency and the wideband slope in both wideband and low-power regimes assuming that the receiver has perfect channel side information (CSI). In both wideband and low-power regimes, the increased energy requirements due to the presence of QoS constraints are quantified. Comparisons with variable-rate/fixed-power and variable-rate/variable-power cases are given. Energy efficiency is further analyzed in the presence of channel uncertainties. The optimal fraction of power allocated to training is identified under QoS constraints. It is proven that the minimum bit energy in the low-power regime is attained at a certain nonzero power level below which bit energy increases without bound with vanishing power.<|reference_end|> | arxiv | @article{qiao2008the,
title={The Impact of QoS Constraints on the Energy Efficiency of Fixed-Rate
Wireless Transmissions},
author={Deli Qiao, Mustafa Cenk Gursoy, and Senem Velipasalar},
journal={arXiv preprint arXiv:0812.1778},
year={2008},
archivePrefix={arXiv},
eprint={0812.1778},
primaryClass={cs.IT math.IT}
} | qiao2008the |
arxiv-5699 | 0812.1780 | On the Energy Efficiency of Orthogonal Signaling | <|reference_start|>On the Energy Efficiency of Orthogonal Signaling: In this paper, transmission over the additive white Gaussian noise (AWGN) channel, and coherent and noncoherent fading channels using M-ary orthogonal frequency-shift keying (FSK) or on-off frequency-shift keying (OOFSK) is considered. The receiver is assumed to perform hard-decision detection. In this setting, energy required to reliably send one bit of information is investigated. It is shown that for fixed M and duty cycle, bit energy requirements grow without bound as the signal-to-noise ratio (SNR) vanishes. The minimum bit energy values are numerically obtained for different values of M and the duty cycle. The impact of fading on the energy efficiency is identified. Requirements to approach the minimum bit energy of -1.59 dB are determined.<|reference_end|> | arxiv | @article{gursoy2008on,
title={On the Energy Efficiency of Orthogonal Signaling},
author={Mustafa Cenk Gursoy},
journal={arXiv preprint arXiv:0812.1780},
year={2008},
archivePrefix={arXiv},
eprint={0812.1780},
primaryClass={cs.IT math.IT}
} | gursoy2008on |
arxiv-5700 | 0812.1811 | Stability of graph communities across time scales | <|reference_start|>Stability of graph communities across time scales: The complexity of biological, social and engineering networks makes it desirable to find natural partitions into communities that can act as simplified descriptions and provide insight into the structure and function of the overall system. Although community detection methods abound, there is a lack of consensus on how to quantify and rank the quality of partitions. We show here that the quality of a partition can be measured in terms of its stability, defined in terms of the clustered autocovariance of a Markov process taking place on the graph. Because the stability has an intrinsic dependence on time scales of the graph, it allows us to compare and rank partitions at each time and also to establish the time spans over which partitions are optimal. Hence the Markov time acts effectively as an intrinsic resolution parameter that establishes a hierarchy of increasingly coarser clusterings. Within our framework we can then provide a unifying view of several standard partitioning measures: modularity and normalized cut size can be interpreted as one-step time measures, whereas Fiedler's spectral clustering emerges at long times. We apply our method to characterize the relevance and persistence of partitions over time for constructive and real networks, including hierarchical graphs and social networks. We also obtain reduced descriptions for atomic level protein structures over different time scales.<|reference_end|> | arxiv | @article{delvenne2008stability,
title={Stability of graph communities across time scales},
author={J.-C. Delvenne, S.N. Yaliraki, and M. Barahona},
journal={arXiv preprint arXiv:0812.1811},
year={2008},
archivePrefix={arXiv},
eprint={0812.1811},
primaryClass={physics.soc-ph cs.IR physics.data-an}
} | delvenne2008stability |
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