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S228843001530021X | In recent years, the automotive industry has known a remarkable development in order to satisfy the customer requirements. In this paper, we will study one of the components of the automotive which is the twist beam. The study is focused on the multicriteria design of the automotive twist beam undergoing linear elastic deformation (Hooke׳s law). Indeed, for the design of this automotive part, there are some criteria to be considered as the rigidity (stiffness) and the resistance to fatigue. Those two criteria are known to be conflicting, therefore, our aim is to identify the Pareto front of this problem. To do this, we used a Normal Boundary Intersection (NBI) algorithm coupling with a radial basis function (RBF) metamodel in order to reduce the high calculation time needed for solving the multicriteria design problem. Otherwise, we used the free form deformation (FFD) technique for the generation of the 3D shapes of the automotive part studied during the optimization process. | Computational design of an automotive twist beam |
S2288430015300233 | This paper proposes eight groups of twenty nine scoring criteria that can help designers and practitioners to compare and select an appropriate methodology for a certain problem in designing product service system (PSS). PSS has been researched for more than a decade and is now becoming more and more popular in academia as well as industry. Despite that fact, the adoption of PSS is still limited for its potential. One of the main reasons is that designing PSS itself is a challenge. Designers and developers face difficulties in choosing appropriate PSS design methodologies for their projects so that they can design effective PSS offerings. By proposing eight groups of twenty nine scoring criteria, this paper enables a “step by step” process to identify the most appropriate design methodology for a company’s PSS problem. An example is also introduced to illustrate the use of the proposed scoring criteria and provide a clear picture of how different design methodologies can be utilized at their best in terms of application. | Development of a novel set of criteria to select methodology for designing product service systems |
S2288430015300245 | Cutter-workpiece engagement (CWE) is the instantaneous contact geometry between the cutter and the in-process workpiece during machining. It plays an important role in machining process simulation and directly affects the calculation of the predicted cutting forces and torques. The difficulty and challenge of CWE determination come from the complexity due to the changing geometry of in-process workpiece and the curved tool path of cutter movement, especially for multi-axis milling. This paper presents a new method to determine the CWE for general milling processes. To fulfill the requirement of generality, which means for any cutter type, any in-process workpiece shape, and any tool path even with self-intersections, all the associated geometries are to be modeled as triangle meshes. The involved triangle-to-triangle intersection calculations are carried out by an effective method in order to realize the multiple subtraction Boolean operations between the tool and the workpiece mesh models and to determine the CWE. The presented method has been validated by a series of case studies of increasing machining complexity to demonstrate its applicability to general milling processes. | Cutter-workpiece engagement determination for general milling using triangle mesh modeling |
S228843001530035X | A designer is mainly supported by two essential factors in design decisions. These two factors are intelligence and experience aiding the designer by predicting the interconnection between the required design parameters. Through classification of product data and similarity recognition between new and existing designs, it is partially possible to replace the required experience for an inexperienced designer. Given this context, the current paper addresses a framework for recognition and flexible retrieval of similar models in product design. The idea is to establish an infrastructure for transferring design as well as the required PLM (Product Lifecycle Management) know-how to the design phase of product development in order to reduce the design time. Furthermore, such a method can be applied as a brainstorming method for a new and creative product development as well. The proposed framework has been tested and benchmarked while showing promising results. | A framework for similarity recognition of CAD models |
S2288430015300415 | Since 3D measurement technologies have been widely used in manufacturing industries edge detection in a depth image plays an important role in computer vision applications. In this paper, we have proposed an edge detection process in a depth image based on the image based smoothing and morphological operations. In this method we have used the principle of Median filtering, which has a renowned feature for edge preservation properties. The edge detection was done based on Canny Edge detection principle and was improvised with morphological operations, which are represented as combinations of erosion and dilation. Later, we compared our results with some existing methods and exhibited that this method produced better results. However, this method works in multiframe applications with effective framerates. Thus this technique will aid to detect edges robustly from depth images and contribute to promote applications in depth images such as object detection, object segmentation, etc. | Depth edge detection by image-based smoothing and morphological operations |
S2288430015300427 | Oval substrates are widely used in automobiles to reduce the exhaust emissions in Diesel oxidation Catalyst of CI engine. Because of constraints in space and packaging Oval substrate is preferred rather than round substrate. Obtaining the flow uniformity is very challenging in oval substrate comparing with round substrate. In this present work attempts are made to optimize the inlet cone design to achieve the optimal flow uniformity with the help of CATIA V5 which is 3D design tool and CFX which is 3D CFD tool. Initially length of inlet cone and mass flow rate of exhaust stream are analysed to understand the effects of flow uniformity and pressure drop. Then short straight cones and angled cones are designed. Angled cones have been designed by two methodologies. First methodology is rotating flow inlet plane along the substrate in shorter or longer axis. Second method is shifting the flow inlet plane along the longer axis. Large improvement in flow uniformity is observed when the flow inlet plane is shifted along the direction of longer axis by 10, 20 and 30mm away from geometrical centre. When the inlet plane is rotated again based on 30mm shifted geometry, significant improvement at rotation angle of 20° is observed. The flow uniformity is optimum when second shift is performed based on second rotation. This present work shows that for an oval substrate flow, uniformity index can be optimized when inlet cone is angled by rotation of flow inlet plane along axis of substrate. | Numerical optimization of flow uniformity inside an under body- oval substrate to improve emissions of IC engines |
S2288430015300439 | The symbiotic organisms search (SOS) algorithm is an effective metaheuristic developed in 2014, which mimics the symbiotic relationship among the living beings, such as mutualism, commensalism, and parasitism, to survive in the ecosystem. In this study, three modified versions of the SOS algorithm are proposed by introducing adaptive benefit factors in the basic SOS algorithm to improve its efficiency. The basic SOS algorithm only considers benefit factors, whereas the proposed variants of the SOS algorithm, consider effective combinations of adaptive benefit factors and benefit factors to study their competence to lay down a good balance between exploration and exploitation of the search space. The proposed algorithms are tested to suit its applications to the engineering structures subjected to dynamic excitation, which may lead to undesirable vibrations. Structure optimization problems become more challenging if the shape and size variables are taken into account along with the frequency. To check the feasibility and effectiveness of the proposed algorithms, six different planar and space trusses are subjected to experimental analysis. The results obtained using the proposed methods are compared with those obtained using other optimization methods well established in the literature. The results reveal that the adaptive SOS algorithm is more reliable and efficient than the basic SOS algorithm and other state-of-the-art algorithms. | Adaptive symbiotic organisms search (SOS) algorithm for structural design optimization |
S2288430015300488 | Optimization of hole-making operations in manufacturing industry plays a vital role. Tool travel and tool switch planning are the two major issues in hole-making operations. Many industrial applications such as moulds, dies, engine block, automotive parts etc. requires machining of large number of holes. Large number of machining operations like drilling, enlargement or tapping/reaming are required to achieve the final size of individual hole, which gives rise to number of possible sequences to complete hole-making operations on the part depending upon the location of hole and tool sequence to be followed. It is necessary to find the optimal sequence of operations which minimizes the total processing cost of hole-making operations. In this work, therefore an attempt is made to reduce the total processing cost of hole-making operations by applying relatively new optimization algorithms known as shuffled frog leaping algorithm and proposed modified shuffled frog leaping algorithm for the determination of optimal sequence of hole-making operations. An industrial application example of ejector plate of injection mould is considered in this work to demonstrate the proposed approach. The obtained results by the shuffled frog leaping algorithm and proposed modified shuffled frog leaping algorithm are compared with each other. It is seen from the obtained results that the results of proposed modified shuffled frog leaping algorithm are superior to those obtained using shuffled frog leaping algorithm. New position of frog Previous position of frog Random number values between 0 to 1 Position of best frog among the memeplexes Position of worst frog among the memeplexes Position of global best frog in search space which best among all frogs. Inertia weight Search acceleration factor with positive values Search acceleration factor with positive values The total holes to be machined in the part are the co-ordinates of point d are the co-ordinates of point e Non-productive tool travel time required for moving tool from the point d to the in rectilinear direction Tool type index in ascending order according to the tool diameters, d=1,…,D Hole index, e=1,…,E f=1,…,E ndex for the last tool to be used on hole e Combined tool and machining costs when tool type d is used on hole e. Cost per unit tool switch time Cost per unit non-productive traveling time he total operations required for hole d., d=1,2,…,D m 1+m 2+…+ m D , the total of operations in the part The tool required for operation e of hole d. The tool travel time for traveling from hole d to hole d’ The time required for switching the tool T d’e’ when tool T de is in spindle 1 if operation e of hole d is machined in position f of operation order, otherwise 0, where 1,2,…,D, e=1,2,…, m i , f=1,2,…, M 1 if T de ≠T d’e’ , otherwise 0 | Tool path planning of hole-making operations in ejector plate of injection mould using modified shuffled frog leaping algorithm |
S228843001530049X | In this paper we present an efficient technique for sketch-based 3D modeling using automatically extracted image features. Creating a 3D model often requires a drawing of irregular shapes composed of curved lines as a starting point but it is difficult to hand-draw such lines without introducing awkward bumps and edges along the lines. We propose an automatic alignment of a user?s hand-drawn sketch lines to the contour lines of an image, facilitating a considerable level of ease with which the user can carelessly continue sketching while the system intelligently snaps the sketch lines to a background image contour, no longer requiring the strenuous effort and stress of trying to make a perfect line during the modeling task. This interactive technique seamlessly combines the efficiency and perception of the human user with the accuracy of computational power, applied to the domain of 3D modeling where the utmost precision of on-screen drawing has been one of the hurdles of the task hitherto considered a job requiring a highly skilled and careful manipulation by the user. We provide several examples to demonstrate the accuracy and efficiency of the method with which complex shapes were achieved easily and quickly in the interactive outline drawing task. | Sketch-based 3D modeling by aligning outlines of an image |
S231471721630006X | Multiple watermarking is used to share the copyright of multiple users, increase robustness and high security. The proposed method is comparison of multiple-watermarking techniques based on Discrete Wavelet Transform and Singular Value Decomposition using Genetic algorithm. This research elaborates the three main categories of multiple watermarking techniques such as successive, segmented and composite watermarking. The experimental results show that the DWT-based watermarking algorithms possess multi-resolution description characteristics achieving imperceptibility. The SVD-based watermarking algorithms add the watermark information to the singular values of the diagonal matrix achieving robustness requirements. The optimization is to maximize the performance of peak signal to noise ratio and normalized correlation in multiple watermarking techniques using genetic algorithms. | Comparison of multiple watermarking techniques using genetic algorithms |
S2352220815000346 | In this work, we incorporate reversibility into structured communication-based programming, to allow parties of a session to automatically undo, in a rollback fashion, the effect of previously executed interactions. This permits to take different computation paths along the same session, as well as to revert the whole session and start a new one. Our aim is to define a theoretical basis for examining the interplay in concurrent systems between reversible computation and session-based interaction. We thus propose ReSπ a session-based variant of π-calculus using memory devices to keep track of the computation history of sessions in order to reverse it. We show how a session type discipline of π-calculus is extended to ReSπ, and illustrate its practical advantages for static verification of safe composition in communication-centric distributed software performing reversible computations. We also show how a fully reversible characterisation of the calculus extends to committable sessions, where computation can go forward and backward until the session is committed by means of a specific irreversible action. | Reversible session-based pi-calculus |
S2352220815000905 | Software product lines (SPLs) facilitate reuse and customization in software development by genuinely addressing the concept of variability. Product Line Calculus of Communicating Systems (PL-CCS) is a process calculus for behavioral modeling of SPLs, in which variability can be explicitly modeled by a binary variant operator. In this paper, we study different notions of behavioral equivalence for PL-CCS, based on Park and Milner's strong bisimilarity. These notions enable reasoning about the behavior of SPLs at different levels of abstraction. We study the compositionality property of these notions and the mutual relationship among them. We further show how the strengths of these notions can be consolidated in an equational reasoning method. Finally, we designate the notions of behavioral equivalence that are characterized by the property specification language for PL-CCS, called multi-valued modal μ-calculus. | Product line process theory |
S235222081500111X | A classical result in algebraic specification states that a total function defined on an initial algebra is a homomorphism if and only if the kernel of that function is a congruence. We expand on the discussion of that result from an earlier paper: extending it from total to partial functions, simplifying the proofs using relational calculus, and generalising the setting to regular categories. | Kernels, in a nutshell |
S2352220815001406 | The paper introduces a bi-intuitionistic modal logic, called BISKT, with two adjoint pairs of tense operators. The semantics of BISKT is defined using Kripke models in which the set of worlds carries a pre-order relation as well as an accessibility relation, and the two relations are linked by a stability condition. A special case of these models arises from graphs in which the worlds are interpreted as nodes and edges of graphs, and formulae represent subgraphs. The pre-order is the incidence structure of the graphs. We present a comprehensive study of the logic, giving decidability, complexity and correspondence results. We also show the logic has the effective finite model property. We present a sound, complete and terminating tableau calculus for the logic and use the MetTeL system to explore implementations of different versions of the calculus. An experimental evaluation gave good results for satisfiable problems using predecessor blocking. | A bi-intuitionistic modal logic: Foundations and automation |
S2352220815001534 | Psi-calculi constitute a parametric framework for nominal process calculi, where constraint based process calculi and process calculi for mobility can be defined as instances. We apply here the framework of psi-calculi to provide a foundation for the exploration of declarative event-based process calculi with support for run-time refinement. We first provide a representation of the model of finite prime event structures as an instance of psi-calculi and prove that the representation respects the semantics up to concurrency diamonds and action refinement. We then proceed to give a psi-calculi representation of Dynamic Condition Response Graphs, which conservatively extends prime event structures to allow finite representations of (omega) regular finite (and infinite) behaviours and have been shown to support run-time adaptation and refinement. We end by outlining the final aim of this research, which is to explore nominal calculi for declarative, run-time adaptable mobile processes with shared resources. | Declarative event based models of concurrency and refinement in psi-calculi |
S2352220816000031 | An important issue in concurrency is interference. This issue manifests itself in both shared-variable and communication-based concurrency — this paper focuses on the former case where interference is caused by the environment of a process changing the values of shared variables. Rely/guarantee approaches have been shown to be useful in specifying and reasoning compositionally about concurrent programs. This paper explores the use of a “possible values” notation for reasoning about variables whose values can be changed multiple times by interference. Apart from the value of this concept in providing clear specifications, it offers a principled way of avoiding the need for some auxiliary (or ghost) variables whose unwise use can destroy compositionality. | Possible values: Exploring a concept for concurrency |
S2352664515000164 | In this paper, a new method for the detection of switching time is proposed for discrete-time linear switched systems, whose switching mechanism is unknown. The switching instant estimation problem consists to predict the mode switching for discrete behavior from a finite set of input–output data. First, the proposed method use a clustering and classification approach define the number of submodels and the data repartition. Then, by the use of statistical learning approach, we define the linear boundary separator of each validity region. Finally, a technique of detection given an explicitly estimation of switching time. A numerical example was reported to evaluate the proposed method. | Classification and statistical learning for detecting of switching time for switched linear systems |
S2352664515000188 | Processing specifications is an issue of crucial importance when developing critical complex systems. In particular, establishing rigorous specifications broadly impacts the subsequent engineering phases. This paper discusses a refinement technique for processing informal specifications expressed in a literal shape, with the aim to generate formal specifications appropriate to automatic processing. The developed technique carries out an iterative process which relies on a set of basic refinement patterns that we have established, and ends up with a formalization step which actually generates logical CTL* formulas. Furthermore, the method implements traceability facilities, which allow for a tidy backtracking of the whole process. The concepts introduced to set up the various mechanisms are discussed and a case study featuring an embedded railway control system is used to illustrate our technique. | A pattern-based method for refining and formalizing informal specifications in critical control systems |
S235266451500019X | Several solutions have been proposed till date to achieve effective replication policies and admission control methods that can ensure a high Quality of Service (QoS) to Video on Demand (VoD) systems. In this paper, we have chosen to study admission control and a replication strategy in a video on demand system called Feedback Control Architecture for Distributed Multimedia Systems (FCA-DMS). The proposed approaches are founded on (i) the supervision and auto-adaptation of the system load, (ii) continued knowledge of the network and of the video servers’ workload, and (iii) the development of a dynamic replication strategy of segments for popular video, that remade to replica-placement problem by discussing the problem of the replicas number to create (Replication Degree). The workload of video servers and of network are calculated by a QoS controller. The proposed approach takes into account of replica detail and offers a replica removal policy to avoid waste and for a good management of storage space. The goal is to maintain an updated broad view of the system’s behaviour from the collected measurements to databases of available videos and databases of available video servers. To demonstrate the efficiency and feasibility of our approaches and validate the results obtained, we conducted a series of experiments based on a simulator that we implemented. | Effect of selective replication strategy and dynamic admission control to QoS management in video on demand systems |
S2352711015000126 | Applications are needed to map biodiversity from large-scale species occurrence datasets whilst seamlessly integrating with existing functions in R. Phylogenetic endemism (PE) is a biodiversity measure based on range-restricted phylogenetic diversity (PD). Current implementations use area of occupancy (AOO) or frequency to estimate the spatial range of branch-length (i.e. phylogenetic range-rarity), rather than extent of occurrence (EOO; i.e. georeferenced phylogenetic endemism), which is known to produce different range estimates. We present R functions to map PD or PE weighted by AOO or EOO (new georeferenced implementation), taking as inputs georeferenced species occurrences and a phylogeny. Non-parametric statistics distinguish PD/PE from trivial correlates of species richness and sampling intensity. The geographic restriction of biodiversity is of interest to the fields of biogeography and conservation biology [1,2], and in particular the historical development and conservation value of concentrations of endemic species [3,4]. Increasingly sophisticated and numerical methods have been developed to measure range-restricted biodiversity. For example, the sum of inverse range-sizes or ‘SIR’ [5,6] of a set of species in a community sample, is a numerically continuous alternative biodiversity measure to counts of species that have been categorically assigned as endemic to a pre-defined area. Rosauer et al. [7] extended the concept of SIR metrics to Faith’s phylogenetic diversity (PD), which is a measure of the evolutionary history represented among a set of species, calculated as the sum of the branch lengths of a phylogenetic tree containing species in a particular community sample [8–10]. This phylogenetic endemism [7] (PE) was defined as (1): PE = ∑ { c ∈ C } L c R c read as the sum of the lengths of each branch in a tree containing a community sample of species divided by the geographic range of each branch (i.e. based on the species terminating from that branch), where L is branch length, R is range size, C is the tree and c is a particular branch of the tree. While a number of methods exist for estimating range sizes [11,12], previously only the number of occupied map grid cells (based on recorded or modelled species occurrences) has been used to estimate ranges that weight this metric. Guerin et al. [13] showed that species ranges, and resulting SIR for map grid cells, estimated with alternative methods were poorly correlated. Specifically, the number of occupied cells (equivalent to frequency or area of occupancy—AOO) was not rank equivalent to measures of extent of occurrence (EOO), leading to recognition of different SIR measures, range-rarity richness (RRR) and georeferenced weighted endemism (GWE), respectively [5]. Since the concepts of range-restricted PD and SIR metrics are linked, we extend here the georeferenced implementation of SIR [13] to its PD equivalent and present new self-contained R [14] functions for calculating and mapping PD and PE, based on species records and relevant phylogenetic trees. The functions can calculate either the existing implementation of PE, where branch length is weighted by its spatial range in terms of the number of occupied grid cells (phylogenetic range-rarity; PRR), or our novel georeferenced implementation, where branch length is weighted by the ‘span’ of constituent species occurrences (georeferenced phylogenetic endemism; GPE). Alternatively, unweighted PD can be mapped. Non-parametric statistics are used to detect outlying grid cells (explained below). These functions address two gaps in current research software: (1) georeferenced calculation of EOO as a weight for calculating PE, to provide different information on the range-restriction of biodiversity than current AOO implementations; (2) functionality in the R environment to map biodiversity metrics including PD/PE from large-scale species occurrence datasets, and to seamlessly integrate inputs and outputs with existing analysis packages. The functions are currently used by loading source into R and calling the functions on simple input data. The functions are principally suited to mapping regional biodiversity to identify conservation priorities. An example of this application would be to convert georeferenced species inventory data into gridded biodiversity heat maps. The outputs are also useful for ecological models in situations where coarse resolution (i.e. map cells rather than field plots) is relevant, or that are based on existing regional inventory data. The existing implementation of PE (and other biodiversity metrics) is available within the perl-based ‘biodiverse’ software [15] with mapping functionality, as well as in the ‘phylo.endemism.R’ function of David Nipperess (released under the GNU GPL: http://davidnipperess.blogspot.com.au/2012/07/phyloendemism-r-function-for.html, accessed 4/2/2015), which calculates a numeric vector of PE for sites in an occurrence matrix but does not have mapping functionality. Our intention, therefore, is to provide a novel implementation with alternative branch weights and to make these functions available in the R environment with automated integration of point data with maps, without requiring sophisticated custom programming from the user. We modified coding for the conversion of phylogenetic data to matrix representation [16] from David Nipperess’ function, while all other coding is new. | Mapping phylogenetic endemism in R using georeferenced branch extents |
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