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what is electromagnetic bandgap structure
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Tunable electromagnetic bandgap structures based on ferroelectric or ferromagnetic thin films were also reported in literature [61]. To achieve tunable EBG performance ferroelectric capacitors are also considered [59] [62].ome alternatives exist to accomplish tuning of Electromagnetic bandgap materials: (1) Micromechanically or electrically modifying the device geometry and/or dielectric loading [59] [60]. (2) By creating some defects and (3) By using ferroelectric and ferromagnetic substrates [62].
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An electromagnetic pulse (EMP), also sometimes called a transient electromagnetic disturbance, is a short burst of electromagnetic energy.Such a pulse may occur in the form of a radiated, electric or magnetic field or a conducted electric current depending on the source, and may be natural or man-made.n EMP arises where the source emits a short-duration pulse of energy. The energy is usually broadband by nature, although it often excites a relatively narrow-band damped sine wave response in the victim. Some types are generated as repetitive and regular pulse trains.
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eng_Latn
| 5,200 |
define switchgear
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Wiktionary(0.00 / 0 votes)Rate this definition: switchgear(Noun) A switching/ interrupting device used in connection with generation, transmission, distribution and conversion of electric power for controling, metering protecting and regulating devices. 52G breaker is the unit main power output breaker.
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The switchgear on the low-voltage side of the transformers may be located in a building, with medium-voltage circuit breakers for distribution circuits, along with metering, control, and protection equipment.
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eng_Latn
| 5,201 |
what is a panel board
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A distribution board (also known as panelboard, breaker panel, or electric panel) is a component of an electricity supply system that divides an electrical power feed into subsidiary circuits, while providing a protective fuse or circuit breaker for each circuit in a common enclosure.
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Distribution board. A distribution board (also known as panelboard, breaker panel, or electric panel) is a component of an electricity supply system that divides an electrical power feed into subsidiary circuits, while providing a protective fuse or circuit breaker for each circuit in a common enclosure.
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eng_Latn
| 5,202 |
what is surge arrester
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A surge arrester is device that intercepts electrical surges and sends the spike to ground before it can hurt a connected device.These arresters are also known as surge protectors or lightning arresters, but there are some very small differences between these devices.his will stop the surge, but it also destroys the device. If the arrester is improperly installed, this fusion can cause more problems than the initial surge. The differences between a surge arrester, a surge protector and a lightning arrester are very minor.
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A surge protector (or surge suppressor) is an appliance/device designed to protect electrical devices from voltage spikes. A surge protector attempts to limit the voltage supplied to an electric device by either blocking or by shorting to ground any unwanted voltages above a safe threshold.
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eng_Latn
| 5,203 |
what does a switchgear do
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In an electric power system, switchgear is the combination of electrical disconnect switches, fuses or circuit breakers used to control, protect and isolate electrical equipment. Switchgear is used both to de-energize equipment to allow work to be done and to clear faults downstream.This type of equipment is directly linked to the reliability of the electricity supply. The very earliest central power stations used simple open knife switch, mounted on insulating panels of marble or asbestos. switchgear may be a simple open-air isolator switch or it may be insulated by some other substance. An effective although more costly form of switchgear is the gas-insulated switchgear (GIS), where the conductors and contacts are insulated by pressurized sulfur hexafluoride gas (SF 6).
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The IOGEAR 4x4 HDMI® Matrix switch connects up to 4 Full HD 1080p source devices with multi-channel digital audio and routes them to any of four connected HDMI displays with support for 3D.
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eng_Latn
| 5,204 |
what is an gfci
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GFCI (ground-fault circuit-interrupter) protection is required for many receptacles (outlets) throughout the house and outdoors. This protection can be provided either by a GFCI breaker or GFCI receptacles. There are advantages and disadvantages to each approach, depending on the installation.
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A ground fault circuit interrupter is an electrical device installed to protect against severe electric shocks. GFCIâs could also reduce electrocutions and minimize electrical burns and shock injuries. A GFCI, not to be confused with an AFCI, integrates a ground fault protection in receptacles where electrical equipment is near water or might be in contact with water. Ground fault circuit interrupter also detects ground faults and interrupts the flow of electric current.
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eng_Latn
| 5,205 |
why is it important to earth electrical devices
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The earth wire is a crucial part of the home electrical system and is designed to protect against electric shock. If faults occur in the electrical system, the electricity will flow to earth by the shortest and easiest path.
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Grounding. Grounding creates a low-resistance path from a tool to the earth to disperse unwanted current. When a short or lightning occurs, energy flows to the ground, protecting you from electrical shock, injury and death. Grounding is a secondary method of preventing electrical shock. Grounded electrical systems are usually connected to a grounding rod that is placed 6-8 feet deep into the earth.
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eng_Latn
| 5,206 |
what is stray capacitance
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Stray capacitance is unwanted and unintended capacitance in a circuit. This can be caused by long wires running parallel to each other or long component leads of components such as from capacitors or inductors.
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The farad (symbol: F) is the SI derived unit of electrical capacitance, the ability of a body to store an electrical charge. It is named after the English physicist Michael Faraday.
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eng_Latn
| 5,207 |
static derfinition
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Full Definition of STATIC. 1. : noise produced in a radio or television receiver by atmospheric or various natural or man-made electrical disturbances; also: the electrical disturbances producing this noise.
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Refer to ICG for qualifiers. In order to use static proximity feature you have to upload the database on the appliance. The custom database is stored in ns.conf, and a static third party database or the database of the appliance is stored in the /var/netscaler/locdb directory, by default.
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eng_Latn
| 5,208 |
what is electrical commissioning
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Electrical testing is typically defined at the equipment level and the systems level. The electrical commissioning professional is involved in the testing of the individual pieces of equipment (generator, ATS, etc.) and then the overall system.The complexity of essential system testing depends on the needs of the facility.ssential/standby power equipment and systems provide electrical power to a facility during a utility power outage or during a partial outage caused by tripping one or more circuit breakers in a facility.
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All electrical installations deteriorate with time and should be inspected and tested every 3 to 5 years for continued service. Such safety checks are commonly known as âperiodic inspectionâ or âdomestic electrical installation condition reportâ.A electrical inspection reports will: 1 Reveal if any of your electrical circuits or equipment are overloaded. 2 Find any potential electric shock risks and fire hazards.ll our engineers are either NICEIC (external link), ELECSA (external link) , or NAPIT (external link) registered and are fully qualified to carry out electrical certificates or domestic electrical installation condition reports.
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eng_Latn
| 5,209 |
simulation software of magnetic circuit
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There are a number of commercial packages you can use for such purposes. Comsol multiphysics simulation software is a general purpose physics modelling software package that I belive can deal with electromagnitism. The link to their website is http://www.uk.comsol.com. Ansys is another commercial vendor that provides a electromagnetic physics module. There website is http://www.ansys.com.
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Enterprise Dynamics® is a simulation software platform to design and implement simulation solutions in Industry, Logistics & Transport. View Profile. Enterprise Dynamics® is a simulation software platform to design and implement simulation solutions in Industry, Logistics & Transport.
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eng_Latn
| 5,210 |
what is a surge
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In general a surge is a transient wave of current, voltage or power in an electric circuit. In power systems in particular â and this is likely the most common context that we relate surges to â a surge, or transient, is a subcycle overvoltage with a duration of less than a half-cycle of the normal voltage waveform.urges are generally measured in microseconds. Every piece of electrical equipment is designed to operate at a specified nominal voltage such as 120 Vac, 240 Vac, 480 Vac, and so on.
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A surge protector (or surge suppressor) is an appliance/device designed to protect electrical devices from voltage spikes. A surge protector attempts to limit the voltage supplied to an electric device by either blocking or by shorting to ground any unwanted voltages above a safe threshold.
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eng_Latn
| 5,211 |
arc flash definition
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Part of the Data center management glossary: An arc flash is an undesired electric discharge that travels through the air between conductors or from a conductor to a ground. The resulting explosion can cause fires and serious harm to equipment and people.
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WHAT IS ARC FLASH. An Arc Flash is very simply, an electrical short circuit through air. Whether it occurs from phase to ground or phase to phase doesn't matter. What does matter is that enough energy is present to perpetuate the arc. Lightning is an example of arc flash as is an electric arc welding machine. The difference between them is that lightning discharges itself in a very short period of time whereas an arc welding machine sustains the arc indefinitely. Either way, you don't want to get too near either of them.
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eng_Latn
| 5,212 |
what is emc testing
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Electromagnetic compatibility (EMC) is the branch of electrical sciences which studies the unintentional generation, propagation and reception of electromagnetic energy with reference to the unwanted effects (electromagnetic interference, or EMI) that such energy may induce.hile electromagnetic interference (EMI) is a phenomenon-the radiation emitted and its effects-electromagnetic compatibility (EMC) is an equipment characteristic or property-not to behave unacceptably in the EMI environment.
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Of the several EMC immunity tests, some are continuous (usually modulated) waves and others are very short bursts (transient) phenomena. The continuous tests are applied to your product over a period of time (minutes to hours).
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eng_Latn
| 5,213 |
can an electrician move an electric meter
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Report Abuse. You need an electrician to move your meter base that is on the home owner not the power company. The power company is only responsible for the meter, not the base.Call some local electrical contractors that do residential wiring and get some estimates to move the meter base and the riser.eport Abuse. You need an electrician to move your meter base that is on the home owner not the power company. The power company is only responsible for the meter, not the base.
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Electric meters. 1 The National Electric Code requires an unobstructed working space that extends from the floor or ground to a minimum height of 6-feet, 6-inches. 2 For electrical equipment mounted higher than 6-feet, 6-inches, this space shall extend to the top of the equipment.
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eng_Latn
| 5,214 |
what is medium voltage
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The term medium voltage (MV) is often used in electric power distribution and utilization. Electric power transmission is often considered to be high voltage only, but some definitions extend MV into the lower levels of power transmission voltage.For power distribution and utilization, LV would be about 100V to 600 or 1000V.lectric power transmission is often considered to be high voltage only, but some definitions extend MV into the lower levels of power transmission voltage. For power distribution and utilization, LV would be about 100V to 600 or 1000V.
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Anything over 50 volts, AC or DC, is considered high voltage. DC is a two wire system, positive (red) and negative (black or yellow), but there can be a third wire, a green grounding wire or a grounding buss connected to the boat's ground. This is not normally a current carrying conductor.
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eng_Latn
| 5,215 |
how fast does a gfci work
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The electrical current may then take an alternative path to the ground through the user, resulting in serious injuries or death. The ground-fault circuit interrupter, or GFCI, is a fast-acting circuit breaker designed to shut off electric power in the event of a ground-fault within as little as 1/40 of a second. It works by comparing the amount of current going to and returning from equipment along the circuit conductors.
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A ground-fault circuit interrupter (GFCI) is the only protection device designed to protect people against electric shock from an electrical system. Because of this, we need to understand what a GFCI is, how it works, and what its limitations are. We need only to look to the NEC for the definition of a GFCI.
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eng_Latn
| 5,216 |
voltage interruption definition
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Voltage Interruptions. A voltage interruption is a large decrease in RMS voltage to less than a small percentile of the nominal voltage, or a complete loss of voltage. Voltage interruptions may come from accidents like faults and component malfunctions, or from scheduled downtime.hort voltage interruptions are typically the result of a malfunction of a switching device or a deliberate or inadvertent operation of a fuse, circuit breaker, or recloser in response to faults and disturbances.
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Essentially, this type of electrical stimulation employs what is referred to as a medium frequency alternating current (in the low kHz range - thousands of cycles a second), which is delivered in a pulsed (or burst or interrupted) output. The pulsing or bursting is at a 'low' frequency, and as a result, nerves will respond.
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eng_Latn
| 5,217 |
what is a afci device
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An arc fault circuit interrupter (AFCI) is a circuit breaker that breaks the circuit when it detects an electric arc in the circuit it protects to prevent electrical fires. An AFCI selectively distinguishes between a harmless arc (incidental to normal operation of switches, plugs, and brushed motors), and a potentially dangerous arc (that can occur, for example, in a lamp cord which has a broken conductor).
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AFCI and GFCI Protection. An AFCI can be used in conjunction with GFCI protection to provide both arcing fault protection as well as 5mA ground fault (people) protection. A common way to provide both types of protection is to use an AFCI circuit breaker and a GFCI receptacle.Q&A). Arc Fault Circuit Interrupters (AFCIs) are required by the National Electrical Code for certain electrical circuits in the home. Below are some frequently asked questions about AFCIs and the benefits of installing them in your home.
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eng_Latn
| 5,218 |
what is a bypass capacitor used for
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The function of the bypass capacitor is to dampen the AC, or the noise. Another term used for the bypass capacitor is a filter cap. In the chart on the left, you can see the what happens to a noisy voltage when a by-pass capacitor is installed.ou can see even with the bypass, the voltage does fluctuate, even though it is to a smaller degree. The key function of the bypass capacitor is to reduce the amount of ripple in a circuit. Too much ripple is bad, and can lead to failure of the circuit.
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1 This is what is called a Bypass Capacitor, because it conducts any changes in voltage to ground. 2 Bypass capacitors DO conduct current when some circuit tries to make the voltage change, such as changing currents drawn by Arduino chips on their circuit board. This is what is called a Bypass Capacitor, because it conducts any changes in voltage to ground. 2 Bypass capacitors DO conduct current when some circuit tries to make the voltage change, such as changing currents drawn by Arduino chips on their circuit board.
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eng_Latn
| 5,219 |
what type of protection does an rcd provide
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A residual current device (RCD) is a safety devicethat switches off electricity automatically if thereis a fault. RCDs are far more sensitive thannormal fuses and circuit-breakers and provideadditional protection against electric shock.Additional protection by means of an RCD canbe a lifesaver.An RCD constantly monitors theelectric current flowing along a circuit.n appliance can then be plugged intothe RCD. These are useful when neither fixed norsocket-outlet RCDs are available, but again theyprovide protection only to the person in contactwith the equipment, including the leads,plugged into the portable RCD.
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RCDs 1 1. What is an RCD and what does it do? An RCD is defined, in BS 7671, as: âA mechanical switching device orassociation of devices intended to causethe opening of the contacts when theresidual current attains a given valueunder specified conditionsâ.. Types of RCDs. RCD is the generic term for a device. that operates when the residual. current in the circuit reaches a. predetermined value. The list above indicates the different. types of RCD available, a description of. each device and examples of how the. device is used.
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eng_Latn
| 5,220 |
how do you find the strength of an electric field
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The electric field strength is inversely related to the square of the distance. So by whatever factor d changes by, the E value is altered in the inverse direction by the square of that factor. The specifics are as follows: a) d increases by a factor of 2; divide the original E by 4.
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Electric fields. 1 Electric fields arise from voltage. 2 Their strength is measured in Volts per metre (V/m) 3 An electric field can be present even when a device is switched off. 4 Field strength decreases with distance from the source. 5 Most building materials shield electric fields to some extent.
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eng_Latn
| 5,221 |
what kind of circuit tester for outlets
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Receptacle tester. A receptacle tester or outlet tester is a device used to verify that an AC wall outlet is wired properly. The tester itself is small device containing a power plug and several indicator lights.
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Quick Answer. A GFCI outlet, or ground-fault circuit interrupter, is an outlet that stops electricity from flowing through it if it detects a problem or a ground-fault. The outlet trips, the same as a breaker trips in an electrical panel, as a safety measure. Continue Reading.
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eng_Latn
| 5,222 |
what is a field strength meter
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Field strength meter is actually a simple receiver. After a tuner circuit, the signal is detected and fed to a microammeter, which is scaled in dBų. The frequency range of the tuner is usually within the terrestrial broadcasting bands.Some FS meters can also receive satellite (TVRO and RRO) frequencies.he relation between the electric field and the transmitted power [edit]. In ideal free space, the electric field strength produced by a transmitter with isotropic radiator is readily calculated.
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We thus define the electric field strength at a point in a field as: E = F/Q where E = electric field strength (N C -1). F = force on charge Q at that point if the field. Important notes: 1 The field strength is a property of the field and not the particular charge that is placed there.
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eng_Latn
| 5,223 |
define emic
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(Äâ²mÄk). adj. Of or relating to phenomena considered as meaningful structural units within a system such as a language or culture. [From (phon)emic .]. eâ²mi·cal·ly adv. (Ëi mɪk). adj.
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Electromagnetic interference. Electromagnetic interference (EMI), also called radio-frequency interference (RFI) when in the radio frequency spectrum, is a disturbance generated by an external source that affects an electrical circuit by electromagnetic induction, electrostatic coupling, or conduction.
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eng_Latn
| 5,224 |
how electricity is transmitted
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To say that you cannot transmit electricity wirelessly is completely wrong. You can actually transmit electricity through the air by magnetic field through a mechanism called â¦inductive coupling or resonance coupling over short distances. Over long distances, you can convert it to microwaves.
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Mains electricity. Mains electricity is the general-purpose alternating-current (AC) electric power supply. Mains electricity is the form of electrical power that is delivered to homes and businesses, and it is the form of electrical power that consumers use when they plug kitchen appliances, televisions and electric lamps into wall sockets. The two principal properties of the electric power supply, voltage and frequency, differ between regions.
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eng_Latn
| 5,225 |
what is an electrical acb
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Ideal Air Circuit Breaker Preference for an Air Circuit Breaker(ACB) can be assessed based onseveral parameters. With diverseapplications and system configurations,the features offered by the ACB haveto be really exhaustive.deal Air Circuit Breaker Preference for an Air Circuit Breaker(ACB) can be assessed based onseveral parameters. With diverseapplications and system configurations,the features offered by the ACB haveto be really exhaustive.
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printed circuit board (PCB) A printed circuit board (PCB) is the board base for physically supporting and wiring the surface-mounted and socketed components in most electronics.
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eng_Latn
| 5,226 |
define emission designator
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Revision as of 15:02, 23 September 2010. An emission designator is a code associated with a frequency that gives information about the frequency's bandwidth and the nature of the signal on the frequency. For scanner users, it can be useful for determining whether a frequency is analog or digital, and even whether the frequency transmits voice and/or data.
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Thermionic emission. Thermionic emission is the thermally induced flow of charge carriers from a surface or over a potential-energy barrier. This occurs because the thermal energy given to the carrier overcomes the work function of the material. The charge carriers can be electrons or ions, and in older literature are sometimes referred to as thermions. After emission, a charge that is equal in magnitude and opposite in sign to the total charge emitted is initially left behind in the emitting region. But if the em
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eng_Latn
| 5,227 |
what is a power surge protector
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A device that shields computer and other electronic devices from surges in electrical power, or transient voltage, that flow from the power supply. Standard American voltage for home and office buildings is 120 volts.ow it Works. A surge protector works by channeling the extra voltage into the outlet's grounding wire, preventing it from flowing through the electronic devices while at the same time allowing the normal voltage to continue along its path.
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Protecting equipment from power outages. Well, clearly a power surge protector didn't help you in this case. It's important to realize what a power surge protector does. It protects from exactly what the name implies-a surge of power. If the voltage for example (which would normally be 120 volts here in the United States) happened to shoot up to 160 or 240 or one of the other higher voltages, the surge protector should protect your equipment by shutting down.
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eng_Latn
| 5,228 |
what is earthing transformer
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Earthing transformers. Earthing transformers are classified as standard reactors. An earthing transformer (neutral coupler) is a three-phase transformer connected to the power system to provide a neutral connection for earthing, either directly or via impedance.The earthing transformers may in addition supply a local auxiliary load.The earthing transformer creates a neutral point for a network.n earthing transformer (neutral coupler) is a three-phase transformer connected to the power system to provide a neutral connection for earthing, either directly or via impedance.
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Ground (electricity) 1 A typical earthing electrode (left of gray pipe), consisting of a conductive rod driven into the ground, at a home in Australia. Most electrical codes specify that the insulation on protective earthing conductors must be a distinctive color (or color combination) not used for any other purpose.
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eng_Latn
| 5,229 |
what is a rife machine used for
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The Rife machine and other types of similar machines produce low energy waves. There is no evidence that the electrical energy the Rife machine produces can destroy cancer cells. A search on the internet brings up different prices for the machine from a few hundred pounds to a couple of thousand pounds.Supporters say there arenât any side effects.laims about the Rife machine. There are several websites claiming that the Rife machine can be used to treat a number of different conditions including cancer. Most of the claims on these websites are personal accounts. They donât have any scientific research to back them up.
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Another key use of ETFE is for the covering of electrical and fiber-optic wiring used in high-stress, low-fume-toxicity and high-reliability situations. Aircraft and spacecraft wiring are primary examples. Some small cross-section wires like the wire used for the wire-wrap technique are coated with ETFE.
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eng_Latn
| 5,230 |
what is the device designed to detect a difference in current between circuit wires (the inward and outward paths) called?
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Best Answer: A. GFCI is the correct answer. Ground Fault Circuit Interruptor: This will open the circuit when a difference in current is detected between the hot and neutral wires in a 120VAC (House current) circuit. B Circuit Breaker will only open the circuit on the hot side when a maximum current is reached. C. Blows open when a maximum current is reached in one line.
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A ground fault circuit interrupter (GFCI) or Residual Current Device (RCD) is a device that shuts off an electric power circuit when it detects that current is flowing along an unintended path, such as through water or a person.
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eng_Latn
| 5,231 |
what is the switchgear
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Leave a comment. Switchgear refers to electrical tool that regulates the flow of electricity within an electrical system. It is used by utility providers and hidden facilities alike for two reasons: to prevent overloads and short circuits, and to de-energize circuits for testing and maintenance.
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Definition of Switchgear. 1 A switchgear or electrical switchgear is a generic term which includes all the switching devices associated with mainly power system protection. It also includes all devices associated with control, metering and regulating of electrical power system.
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eng_Latn
| 5,232 |
what happens when a capacitor shorts
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When the switch is first closed, the voltage across the capacitor (which we were told was fully discharged) is zero volts; thus, it first behaves as though it were a short-circuit. Over time, the capacitor voltage will rise to equal battery voltage, ending in a condition where the capacitor behaves as an open-circuit.
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Shorts or faults can damage your toys and burn down your house. Circuit Protection on the low voltage side of transformers is the same as having breakers in the circuit box for your house wiring. There are many techniques for wiring a layout.
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eng_Latn
| 5,233 |
what is a substation inside a building
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Substations are normally outdoors and are enclosed by a wire fence. However in residential or high density areas, the substation may be indoors and housed inside a building to restrict the humming noise of the huge transformers. slide 2 of 6 View of a Substation
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The substation is protected from faults on feeder and tie lines by circuit breakers and/or reclosers located inside the substation. Most of the faults are permanent on an underground distribution system, thereby requiring a different protection approach.
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eng_Latn
| 5,234 |
do you physically have to go switch the outlet off or does it sense when it is no longer in use?
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Has a switch for off/on, just like you'd flick for a light switch... and the switch lights up green when on.
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The device either absorbs the surge and/or passes it to ground. Manufacturers don't provide this information with their product, but I would expect the whole-house variety to do both. To the extent that they pass it to ground they might need to take less of a self-sacrificing hit. If you want more technical information, I would suggest WikiPedia.com. But the technical details are unlikely to be useful in choosing among products.
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eng_Latn
| 5,235 |
Relationship between electromagnetic wave and photon What is the physical meaning of a single photon's frequency? When the fields cross zero, is there less probability of finding an photon there? What does the amplitude of the waves represent, if anything? And if the frequency has to do with probability, how to interpret circularly polarized light where there's no point that the magnetic and electric fields are both zero?
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What is the relation between electromagnetic wave and photon? At the end of this nice video (), she says that is a chain reaction of electric and magnetic fields creating each other so the chain of wave moves forward. I wonder where the is in this explanation. What is the relation between electromagnetic wave and photon?
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Connecting two Ethernet PHY without magnetics? In a (tentative) new design I want to connect two 100 Mbit/s Ethernet PHY similar to , separated by few inches on the same PCB, with same ground plane (but different power supplies). I have the choice of one of my PHY, but the other is embedded in an as-yet-unspecified PCIe to Ethernet IC (perhaps Gigabit but used in 100 Mbit/s mode), and it is critical that this PHY thinks there is a bona fide 100 Mbit/s Ethernet connection. I could use the following – Schematic created using but I would like to achieve the same without the magnetics, in order to save on cost, purchasing headaches, and if at all possible power consumption. I can imagine an RC network, perhaps as simple as in this , found thanks to a ; or maybe engineered with attenuation and lowpass, but that will not emulate the fact that with real magnetics, when there is a negative pulse on TX1P, there is a positive pulse on TX1M and RX2M. I am uncertain about if that would prevent some PHYs from working normally. Anything to suggest that one is confident will work for practically any PHY around?
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eng_Latn
| 5,236 |
I want to test a house next to a power line.....who should I call?
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You might start by contacting the power company. If you have concerns about eletromagnetic interference, they should be willing to help you.
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That's a complicated question and the answer depends on the authority of your local zoning board. Is the area in the city limits or the county? What kind of zoning authority exists for that area?\n\nUsually the zoning authority is comprised of local elected officials or those appointed by the elected officials. the best place to voice your compliant is with your county commission or town council (depending on who has juristiction of the area in question) Most County Commissions and Town/City Councils have opportunities for public comment during public meetings. \n\nIf this is a true problem that is being contributed to by elected officials - the true punishment comes on voting day when the voters voice their concerns.
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eng_Latn
| 5,237 |
is microwave a computer
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Yes, a microwave oven can interfere with electromagnetic equipment, like a computer. A microwave oven can also interfere with radio signals, like those used for wireless Inter ⦠net and cell phones.
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If youâre in the market for a new computer, itâs necessary to understand the function of a CPU. Also known as the Central Processing Unit or processor, the CPU is essentially the âbrainsâ of your computer. Without the CPU, you wouldnât be able to play games, type research papers, or surf the Internet. heatsink is the part of a computer designed to move heat away from a computer's central processing unit. The CPU is placed into a pre-configured slot in a motherboard and acts as the brain of any computer. The CPU is the brain of the computer. View slideshow of images above.
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eng_Latn
| 5,238 |
what is whole house surge protection
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Luckily, thereâs an easy and affordable way to avoid these kinds of losses â and it all starts with a whole house surge protector. Learn more about power surges and how whole house surge protectors can help protect your home and valuables below. What Are Power Surges? Weâve all experienced a power surge in our homes or somewhere else â but what exactly are power surges? And what causes them? Put simply, a power surge is a spike in an electrical current.
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Please check your local sales tax laws. Mount the T8061 Ethernet Surge Protector from Axis Communications to a wall with the included mount to protect your Ethernet lines and network devices from surges. Ideally mounted outside of the building, this surge protector is IP66- and NEMA-4X-rated for protection against dust, water, ice, and corrosion.
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eng_Latn
| 5,239 |
how to protect computer from blackouts
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Cram Quiz Answers. 1 B. The UPS is the only item listed that protects the computer from power outages like blackouts and brownouts. 2 B. A surge protector is the right solution at the right price. 3 C. A spike (or a surge) is an unexpected increase in voltage.
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Warnings. 1 While unplugging the CPU components, please keep your children and pets away from the area to avoid hazard of electrical shock. 2 The edges of metal panels in the CPU can cut your skin. 3 Wear safety goggles to protect your eyes while removing dust from the CPU components.
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eng_Latn
| 5,240 |
how does a surge protector work
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So how do surge protectors work? Basically, the electrical current flows from the wall to your surge protector and then to your electrical devices. When there is a surge, the extra voltage is diverted to the grounding wire inside the surge protector.
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Surge protectors act like an electrical sponge of sorts, absorbing excess voltage, thereby protecting the coach. RV surge protection should include the ability to completely shut off the incoming power before damaging transients can reach sensitive equipment.
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eng_Latn
| 5,241 |
A Measurement System for Capacitive PUF-Based Security Enclosures
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Fringe-Effect Capacitive Proximity Sensors for Tamper Proof Enclosures
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Modeling attacks on physical unclonable functions
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eng_Latn
| 5,242 |
Improving bug localization using structured information retrieval
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Scalable statistical bug isolation
|
Miniaturized Dual-Band Wilkinson Power Divider With Self-Compensation Structure
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eng_Latn
| 5,243 |
Power without wires
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Power transfer for a running automobile
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building blocks of an e - government : a framework .
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eng_Latn
| 5,244 |
what is an emergency generator system
|
Emergency power system. An emergency power system is an independent source of electrical power that supports important electrical systems on loss of normal power supply. A standby power system may include a standby generator, batteries and other apparatus.
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(Redirected from Emergency Communication System) An emergency communication system (ECS) is any system (typically, computer-based) that is organized for the primary purpose of supporting one-way and two-way communication of emergency messages between both individuals and groups of individuals.
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eng_Latn
| 5,245 |
electrical definition of iec
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The IEC is one of the bodies recognized by the World Trade Organization and entrusted by it for monitoring the national and regional organizations agreeing to use the IEC's international standards as the basis for national or regional standards as part of the WTO's Technical Barriers to Trade Agreement.
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(Aberdeen) LTD and will specialise in the supply of IEC control, automation and IECEx hazardous area electrical equipment, as well as the manufacturing of control panels and Low Voltage switchboards to the North American Market. AEL Specialist Electrical Distributors are Proud to Announce their ... by PR Newswire.
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eng_Latn
| 5,246 |
what is ev mode
|
Charge-depleting or EV mode refers to a mode of vehicle operation that is dependent on energy from the battery pack. Battery electric vehicles operate solely in this mode. Most plug-in hybrids operate in charge-depleting mode at startup, and switch to charge-sustaining mode after the battery has reached its minimum state of charge (SOC) threshold, exhausting the vehicle's all-electric range (AER).
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A transit mode that is an electric system of aerial cables with suspended powerless passenger vehicles. The vehicles are propelled by separate cables attached to the vehicle suspension system and powered by engines or motors at a central location not on-board the vehicle.
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eng_Latn
| 5,247 |
what states require use of the iecc?
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In Delaware, the IECC has been mandated by legislation as a statewide code. Division of Energy & Climate is responsible for adopting the code. office at (302)735-3480 for energy code questions and interpretations. enforcement issues, the local building department should be contacted.
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Only six states, Alabama, Florida, Kentucky, South Carolina, Tennessee and Virginia, still authorize use of the electric chair, according to the Death Penalty Information Center. The six states will electrocute only those inmates who request it, according to The Washington Post.
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eng_Latn
| 5,248 |
describe the electricity at work regulations 1989
|
Electricity at Work Regulations 1989. This legislation places legal implications on employers to ensure the safety of electrical devices in the workplace. The regulations dictate that all portable equipment must be inspected regularly and tested to ensure that it is safe for use.his legislation places legal implications on employers to ensure the safety of electrical devices in the workplace. The regulations dictate that all portable equipment must be inspected regularly and tested to ensure that it is safe for use.
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The purpose of these regulations is to require precautions to be taken against the risk of death or persoanl injury from electricity in work activities.The regulations impose duties on persons in respect of systems, electrical equipment and conductors and in respect of work activities on or near electrical equipment.cope of the Regulations. See also; 1 The Electricity at Work Regulations 1989 (EAW Regulations) came into force on 1 April 1990. 2 PAT: Hints and Tips.
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eng_Latn
| 5,249 |
what is fcu
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Call a qualified electrician. Fitting a FCU. There are three types of fused connection units: - unswitched, switched with flex outlet and switched without flex outlet. Fused connection units are used as a means of connecting permanent appliances such as cooker hoods to the electrical circuits of the house.
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Empower Federal Credit Union (FCU), a full-service financial institution with more than $1.3 billion in assets, has signed a multi-year agreement with Vantiv, Inc., a NAFCU Services Preferred Partner, to offer a complete suite of payment processing solutions and related services for new and existing members.
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eng_Latn
| 5,250 |
is a low voltage license needed in new mexico
|
Low-Voltage/Limited Energy License: A low-voltage special systems license is required to perform certain work under 50 volts.ow-Voltage/Limited Energy License: A low-voltage special systems license is required to perform certain work under 50 volts.
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What is Low Voltage? Many owner builders are unfamiliar with the term low voltage. It is electrical wiring and trim that does not carry the same current as the power outlets, fixtures and switches in a home. Items that are considered low voltage fall under less scrutiny during inspections because the open wire does not pose the same electrocution threat that a standard wire would. In most cases, the majority of the low volt installation will occur at the same time as the basic electrical. Other times, it will follow just after basic electrical. It can be done by a different crew of the same electrical company or a separate outfit that specializes in low voltage work.
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eng_Latn
| 5,251 |
plz help me any body?
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11 - A\n12 - None of them the symbol for current is I\nE = Energy\nR = Resistance\nC = Capacitance\n* = nothing
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use emule\nits a peer to peer software\ngo to google.com\ntype emule and download the software and install it restu will come to know its user friendly\ndirect link\nemuleproject.net
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eng_Latn
| 5,252 |
what is ip rating ip20
|
The IP Code, International Protection Marking, IEC standard 60529, sometimes interpreted as Ingress Protection Marking, classifies and rates the degree of protection provided against intrusion (body parts such as hands and fingers), dust, accidental contact, and water by mechanical casings and electrical enclosures.or example a particular cellular phone rated at IP58 is dust resistant and can be immersed in 1.5 meters of freshwater for up to 30 minutes. IP22 or 2X are typical minimum requirements for the design of electrical accessories for indoor use.
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IP (or Ingress Protection) ratings are defined in international standard EN 60529 (British BS EN 60529:1992, European IEC 60509:1989). They are used to define levels of sealing effectiveness of electrical enclosures against intrusion from foreign bodies (tools, dirt etc) and moisture.P (or Ingress Protection) ratings are defined in international standard EN 60529 (British BS EN 60529:1992, European IEC 60509:1989). They are used to define levels of sealing effectiveness of electrical enclosures against intrusion from foreign bodies (tools, dirt etc) and moisture.
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eng_Latn
| 5,253 |
what is a lineman job
|
An electrical lineman, commonly referred to as an outside lineman or simply a lineman, is an electrician who is trained to install, maintain and repair the high-power transmission and distribution lines and systems that deliver electric power from the generating source to the end user.
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Linemen also do work on traffic signals and street lights. The work is varied and exciting.The duties of an outside lineman are listed below. Tasks within each of the duties are included in the job description if they are performed by at least 10 percent of the journeymen surveyed.
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eng_Latn
| 5,254 |
functions of an electric lineman
|
Also referred to as: Lineman, Line Repairman Requirements and Responsibilities Constructs, maintains, and inspects transmission and distribution of electrical or power lines.
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Journeyman Lineman East Central Oklahoma Electric Cooperative (ECOEC) is currently accepting applications for a Journeyman Lineman. All qualified applicants will be considered. The job will be offered to the most qualified applicant, as determined by East Central Electric.
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eng_Latn
| 5,255 |
Can 2 level 6 lightning spell and 1 level 2 earthquake spell destroy 2 air defenses with a air sweeper placed between them?
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Can 2 level 6 lightning spell and 1 level 2 earthquake spell destroy 2 air defenses with a air sweeper placed between them in one straight line?
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How many power strips could you chain together with additional appliances plugged in along the way before you are in danger of dying?
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eng_Latn
| 5,256 |
Power allocation for multi-antenna systems with space-time block coding in the presence of estimation error and delayed feedback
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Performance analysis of Alamouti diversity with sub-optimum transmit antenna selection using delayed feedback
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Completely Stale Transmitter Channel State Information is Still Very Useful
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eng_Latn
| 5,257 |
Distributed space-time block codes (DSTBCs) from complex orthogonal designs (CODs) (both square and nonsquare), coordinate interleaved orthogonal designs (CIODs), and Clifford unitary weight designs (CUWDs) are known to lose their single-symbol ML decodable (SSD) property when used in two-hop wireless relay networks using amplify and forward protocol. For such networks, in this paper, three new classes of high rate, training-symbol embedded (TSE) SSD DSTBCs are constructed: TSE-CODs, TSE-CIODs, and TSE-CUWDs. The proposed codes include the training symbols inside the structure of the code which is shown to be the key point to obtain the SSD property along with the channel estimation capability. TSE-CODs are shown to offer full-diversity for arbitrary complex constellations and the constellations for which TSE-CIODs and TSE-CUWDs offer full-diversity are characterized. It is shown that DSTBCs from nonsquare TSE-CODs provide better rates (in symbols per channel use) when compared to the known SSD DSTBCs for relay networks. Important from the practical point of view, the proposed DSTBCs do not contain any zeros in their codewords and as a result, antennas of the relay nodes do not undergo a sequence of switch on/off transitions within every codeword, and, thus, avoid the antenna switching problem.
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We introduce space-time block coding, a new paradigm for communication over Rayleigh fading channels using multiple transmit antennas. Data is encoded using a space-time block code and the encoded data is split into n streams which are simultaneously transmitted using n transmit antennas. The received signal at each receive antenna is a linear superposition of the n transmitted signals perturbed by noise. Maximum-likelihood decoding is achieved in a simple way through decoupling of the signals transmitted from different antennas rather than joint detection. This uses the orthogonal structure of the space-time block code and gives a maximum-likelihood decoding algorithm which is based only on linear processing at the receiver. Space-time block codes are designed to achieve the maximum diversity order for a given number of transmit and receive antennas subject to the constraint of having a simple decoding algorithm. The classical mathematical framework of orthogonal designs is applied to construct space-time block codes. It is shown that space-time block codes constructed in this way only exist for few sporadic values of n. Subsequently, a generalization of orthogonal designs is shown to provide space-time block codes for both real and complex constellations for any number of transmit antennas. These codes achieve the maximum possible transmission rate for any number of transmit antennas using any arbitrary real constellation such as PAM. For an arbitrary complex constellation such as PSK and QAM, space-time block codes are designed that achieve 1/2 of the maximum possible transmission rate for any number of transmit antennas. For the specific cases of two, three, and four transmit antennas, space-time block codes are designed that achieve, respectively, all, 3/4, and 3/4 of maximum possible transmission rate using arbitrary complex constellations. The best tradeoff between the decoding delay and the number of transmit antennas is also computed and it is shown that many of the codes presented here are optimal in this sense as well.
|
The objective of this study is to find out the spatial and temporal variability of the dry and wet spells in Greece, during the period 1958–2007. The meteorological data with respect to daily precipitation totals were acquired from 27 meteorological stations of the Hellenic National Meteorological Service, which are uniformly distributed over the country. The dry spells concern consecutive dry days (CDD); the largest number of consecutive days with daily precipitation amount less than 1 mm, within a year. The wet spells concern consecutive wet days (CWD); the largest number of consecutive days with daily precipitation amount more than or equal to 1 mm, within a year, as defined by the Expert Team on Climate Change Detection and Indices (ETCCDI), jointly sponsored by the Commission for Climatology (CCl) of the World Meteorological Organization's (WMO) World Climate Data and Monitoring Programme (WCDMP), the Climate Variability and Predictability (CLIVAR) Programme of the World Climate Research Programme (WCRP) and the Joint WMO-IOC Technical Commission for Oceanography and Marine Meteorology (JCOMM). As results from the analysis, the spatial distributions of the mean annual CDD and the mean annual CWD along with their trends, within the examined period, are presented. The findings indicate that CDD obtain maxima in the Cyclades Islands and the southeastern Aegean Sea, while minima are found in the northwestern Greece. On the contrary, the longest CWD are observed in western Greece and western part of Crete Island and the shortest in the eastern continental Greece and in the majority of the Aegean Sea. On an annual basis, the temporal variability of CWD shows statistically significant (confidence level of 95%) negative trends, mainly in the western region of Greece, while insignificant positive trends for CDD appear almost all over the country with emphasis in the southeastern region. Finally, in order to interpret the drier and wetter periods within the examined period, the 850 hPa and the 500 hPa geopotential height (m) composites of the anomalies from 1958–1996 climatological normal (clino), are analysed using the National Centers for Environmental Prediction (NCEP) reanalysis data.
|
eng_Latn
| 5,258 |
Purpose Given that smoking affects body mass index (BMI) and survival, stratification by smoking status may be required to determine the true prognostic impact of BMI. Although obesity increases risk for developing esophageal adenocarcinoma (EAC), the prognostic influence of obesity and its potential modification by smoking status is unknown in this disease. Patients and Methods All patients (N = 778) underwent potentially curative esophagectomy. BMI was calculated using measured height and weight at surgery and categorized as obese (≥ 30 kg/m2), overweight (25 to 29.9 kg/m2), or normal (18.5 to 24.9 kg/m2). Cigarette smoking was categorized as never or ever. The association of BMI with disease-specific survival (DSS), disease-free survival (DFS), and overall survival (OS) was determined by Cox regression. Results Excess BMI was significantly associated with DSS in a manner that differed substantially by smoking status (P for interaction = .023). Among never smokers, obesity was significantly associated w...
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Background ::: Patients with overweight reportedly have more comorbidities, including diabetes mellitus and cardiovascular disease, and longer operating times as well as more blood loss during surgery compared with those with normal weight. However, the impact of overweight on the short-term outcome after transthoracic esophagectomy for patients with esophageal squamous cell carcinoma (ESCC) remains unclear. We hypothesized that overweight has a negative impact on short-term surgical outcomes after esophagectomy for patients with ESCC.
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In this article, we propose an improved multiple feedback successive interference cancellation (IMF-SIC) algorithm for symbol vector detection in multiple-input multiple-output (MIMO) spatial multiplexing systems. The multiple feedback (MF) strategy in successive interference cancellation (SIC) is based on the concept of shadow area constraint (SAC) where, if the decision falls in the shadow region multiple neighboring constellation points will be used in the decision feedback loop followed by the conventional SIC. The best candidate symbol from multiple neighboring symbols is selected using the maximum likelihood (ML) criteria. However, while deciding the best symbol from multiple neighboring symbols, the SAC condition may occur in subsequent layers which results in inaccurate decision. In order to overcome this limitation, in the proposed algorithm, SAC criteria is checked recursively for each layer. This results in successful mitigation of error propagation thus significantly improving the bit error rate (BER) performance. Further, we also propose an ordered IMF-SIC (OIMF-SIC) where we use log likelihood ratio (LLR) based dynamic ordering of the detection sequence. In OIMF-SIC, we use the term dynamic ordering in the sense that the detection order is updated after every successful decision. Simulation results show that the proposed algorithms outperform the existing detectors such as conventional SIC and MF-SIC in terms of BER, and achieves a near ML performance.
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eng_Latn
| 5,259 |
Performance Analysis of ZF and MMSE Algorithms for MIMO Systems
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In the paper we consider a method of efficiency improvement for Zero-Force (ZF) and Minimum Mean-Squared Error (MMSE) decision making algorithms in Multiple-Input Multiple-Output (MIMO) data transmission systems. A gain provided by the proposed approach is estimated for a few scenarios via simulations.
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Abstract In this paper, we consider the generalized Benjamin–Bona–Mahony (BBM) equation with a fractional order derivative in time. By introducing a weighted approach and basing on the L 2 - 1 σ formula, a linearized finite difference scheme is proposed to solve the nonlinear problem. The scheme is shown to be unconditionally convergent with second-order in time and space within maximum-norm estimate.
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kor_Hang
| 5,260 |
Synthesis and screening of small-molecule α-helix mimetic libraries targeting protein-protein interactions.
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α-Helices are the most common protein secondary structure and play a key role in mediating many protein-protein interactions (PPIs) by serving as recognition motifs. Given that aberrant α-helix-mediated PPIs are linked to various disease states, targeting such interactions with small-molecules represents an attractive strategy to develop therapeutic candidates for the related diseases. Over the last decade, significant efforts have been directed toward developing α-helix mimetic small-molecules that can modulate α-helix-mediated PPIs. In this review, we will highlight recent advances in the development of non-peptidic, small-molecule α-helix mimetics with a focus on library synthesis and screening methods to efficiently discover small-molecule α-helix mimetics.
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Pulse compression is a desirable approach to design pulses in jammed environment. It is important to have a phase coder sequence which has limited side-lobe level in correlation function, in phase coded pulse compression. This paper is discussing about the anti-jamming property of phase coded waveform which is coded with a sequence which has correlation function with limited side-lobe level. This sequence is constructed with minimizing the Integrated Side-lobe Level (ISL). After constructing this sequence it is used to modulate the pulse in jammed environments and its capability is measured in two different jamming scenarios called deceptive jammer and barrage jammer. It is observed that in barrage jammer scenario this phase coded waveform can resist very powerfully and in deceptive jammer scenario it can, too. In later scenario the anti-jamming capability of the waveform depends on the length of phase coder sequence.
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eng_Latn
| 5,261 |
Poly Si-Si interfacial oxide ball-up mechanism and its control for 0.8 mu m BiCMOS VLSIs
|
Three samples with different thicknesses of polysilicon-silicon interfacial oxide were prepared. The influence of the interfacial oxide on the electrical characteristics of 0.8- mu m BiCMOS VLSIs was studied. From the results, the maximum interfacial oxide thickness allowed for BiCMOS LSIs was determined. To control the interfacial oxide thickness, the ball-up mechanism was studied using HRXTEM combined with energy-dispersive X-ray spectroscopy measurements. The optimum heat treatment after emitter deposition to realize 0.5- mu m BiCMOS VLSI was also determined. >
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In practical systems, due to the time-varying radio channel, the channel state information (CSI) may not be known well at both transmitters and receivers. For most of the current multiuser multiple-input multiple-output (MIMO) schemes, they suffer a significant degression on the performance due to the mismatch between the true and estimated CSI. To alleviate the performance penalty, a robust downlink multiuser MIMO scheme is proposed in this paper by exploiting the channel mean and antenna correlation. These channel statistics are more stable than the imperfect CSI estimation in the time-varying radio channel, and they are used, in the proposed scheme, to minimize the total mean squared error under the sum power constraint. Simulation results demonstrate that the proposed scheme effectively mitigates the performance loss due to the CSI mismatch.
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eng_Latn
| 5,262 |
M-ary Detection and q-ary Decoding in Large-Scale MIMO: A Non-Binary Belief Propagation Approach
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Random-Restart Reactive Tabu Search Algorithm for Detection in Large-MIMO Systems
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Mdm2 promotes the rapid degradation of p53
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eng_Latn
| 5,263 |
Identification of Operators with Bandlimited Symbols
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A discrete model for the efficient analysis of time-varying narrowband communication channels
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Completely Stale Transmitter Channel State Information is Still Very Useful
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eng_Latn
| 5,264 |
Increasing data reuse of sparse algebra codes on simultaneous multithreading architectures
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An overview of the sparse basic linear algebra subprograms: The new standard from the BLAS technical forum
|
The Gaussian non-cooperative multiple access channel with Rayleigh fading
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eng_Latn
| 5,265 |
Power Control and Channel Training for MIMO Channels: A DMT Perspective
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Communication on the Grassmann Manifold: A Geometric Approach to the Noncoherent Multiple-Antenna Channel
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Mdm2 promotes the rapid degradation of p53
|
eng_Latn
| 5,266 |
Optical 2-dimensional multiple-broadcasting for massively parallel multicomputers
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Space multiplexing of waveguides in optically interconnected multiprocessor systems
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Multi-channel Opportunistic Access: A Case of Restless Bandits with Multiple Plays
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eng_Latn
| 5,267 |
ON LEFT α-MULTIPLIERS AND COMMUTATIVITY OF SEMIPRIME RINGS
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Identities with generalized derivations in semiprime rings
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Mimo Transceiver Design Via Majorization Theory
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yue_Hant
| 5,268 |
Two-User Gaussian Interference Channel with Finite Constellation Input and FDMA
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On the relay gain of the fading relay channel with finite input constellations
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Completely Stale Transmitter Channel State Information is Still Very Useful
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eng_Latn
| 5,269 |
On the design of bit-interleaved turbo-coded modulation
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Performance of bit-interleaved turbo-coded modulations on Rayleigh fading channels
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Performance of bit-interleaved turbo-coded modulations on Rayleigh fading channels
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eng_Latn
| 5,270 |
An Asymptotic Analysis of the MIMO BC under Linear Filtering
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The Impact of Frequency-Flat Fading on the Spectral Efficiency of CDMA
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On the Fundamental Limits of Recovering Tree Sparse Vectors From Noisy Linear Measurements
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eng_Latn
| 5,271 |
Per-cluster-prediction based sparse channel estimation for multicarrier underwater acoustic communications
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Adaptive Channel Estimation and Data Detection for Underwater Acoustic MIMO–OFDM Systems
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New simple and efficient heuristics for the uncapacitated single allocation hub location problem
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eng_Latn
| 5,272 |
Some Insights into MIMO Mutual Information: The High SNR Case
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The capacity of MIMO systems with increasing SNR by electromagnetic analysis
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Mdm2 promotes the rapid degradation of p53
|
kor_Hang
| 5,273 |
On the minimum side information of MIMO broadcast channel
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Multi-Antenna Downlink Channels with Limited Feedback and User Selection
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Completely Stale Transmitter Channel State Information is Still Very Useful
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eng_Latn
| 5,274 |
Abstraction and the CSP Phase Transition Boundary
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Eliminating Interchangeable Values in Constraint Satisfaction Problems
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Completely Stale Transmitter Channel State Information is Still Very Useful
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eng_Latn
| 5,275 |
Rate maximization in coupled MIMO systems: A generic algorithm for designing single-port matching networks
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Optimal Noise Matching for Mutually Coupled Arrays
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Achievable sum-rate analysis for massive MIMO systems with different array configurations
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eng_Latn
| 5,276 |
Turbo coding performance in OFDM packet transmission
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Joint coding-precoding with low-complexity turbo-decoding
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Blind channel estimation for precoded OFDM system
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eng_Latn
| 5,277 |
Capacity Analysis of Massive MIMO on High Altitude Platforms
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Achievable sum-rate analysis for massive MIMO systems with different array configurations
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Iterative overlap QRM-MLBD for single-carrier MIMO transmission without CP insertion
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eng_Latn
| 5,278 |
Statistical modeling of wind turbines' bi-static free-space scattering characteristics for UHF-band applications
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Wind farms' interference effects on the error performance of wireless line-of-sight communications using binary digital modulations
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Completely Stale Transmitter Channel State Information is Still Very Useful
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eng_Latn
| 5,279 |
Turbo joint source-channel coding of non-uniform memoryless sources in the bandwidth-limited regime
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Non-systematic turbo coding with unequal energy allocation for nonuniform memoryless sources
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Completely Stale Transmitter Channel State Information is Still Very Useful
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eng_Latn
| 5,280 |
A model for performance evaluation in M-QAM-OFDM schemes in prescence of nonlinear distortions
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A robust design of TC-OQAM schemes with nonlinear transmitters
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A robust design of TC-OQAM schemes with nonlinear transmitters
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eng_Latn
| 5,281 |
Prime sequences: quasi-optimal sequences for OR channel code division multiplexing
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Coherent optical pulse CDMA systems based on I-Q noncoherent demodulation of M-ary orthogonal signals
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Primordial non-Gaussianity in the large scale structure of the Universe
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eng_Latn
| 5,282 |
On the stochastic and deterministic behavior of mmWave channels
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Better than Rician: Modelling millimetre wave channels as Two-Wave with Diffuse Power
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Completely Stale Transmitter Channel State Information is Still Very Useful
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eng_Latn
| 5,283 |
An improved multi-branch residual network based on random multiplier and adaptive cosine learning rate method
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DBNet: A New Generalized Structure Efficient for Classification
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The Gaussian non-cooperative multiple access channel with Rayleigh fading
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eng_Latn
| 5,284 |
A Novel Space-Frequency Block Coding Scheme for SC-FDMA
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Optimal PAPR reduction scheme for MIMO SC-FDMA-performance evaluation study
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Completely Stale Transmitter Channel State Information is Still Very Useful
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eng_Latn
| 5,285 |
In this contribution we propose a new way to state and solve the channel equalization problem for an OFDM (orthogonal frequency division multiplexing) system, without the use of a guard interval. Therefore, the spectral efficiency is increased. The approach is based on the channel representation as a polynomial matrix. We develop a new decomposition of this matrix, which diagonalizes the channel matrix independently of the channel realization. It leads to a simple inversion of the channel matrix. The decomposition consists of forward and inverse DFTs and polynomial diagonal matrices. Further on, there is no restriction on the length of the channel impulse response
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Relying on basic tools such as eigensignals of linear time-invariant systems, linear and circular block convolution, and fast Fourier transforms (FFTs), this article develops a systematic discrete-time framework and designs novel systems for single- and multiuser wireless multicarrier communications-a field rich in signal processing challenges that holds great potential in various applications including audio/video broadcasting, cable television, modem design, multimedia services, mobile local area networks, and future-generation wideband cellular systems. Wireless multicarrier (MC) communication systems utilize multiple complex exponentials as information-bearing carriers. MC transmissions thus retain their shape and orthogonality when propagating through linear time-dispersive media, precisely as eigensignals do when they pass through linear time-invariant (LTI) systems.
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We characterize stability under composition, inversion, and solution of ordinary differential equations for ultradifferentiable classes, and prove that all these stability properties are equivalent.
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eng_Latn
| 5,286 |
An adaptive multiple input and multiple output (MIMO) system based on the unified belief propagation (BP) detection is proposed. A BP detector composed of a serial of component detectors is first presented. With a unified design of the BP detector, a multi-rate MIMO system adaptive to channel variations is then developed, which aims at achieving the maximal throughput performance. The usage of the unified BP detector eliminates the multiple detector modules at the receiver in conventional multi-mode adaptive MIMO systems. Further, the linear complexity to space time block length and parallel operation of the unified BP detection provide the advantages of low complexity, low detection delay and smooth switching between different data rates. With the average receiving signal-to-noise ratio (SNR) based switching mechanism, the proposed adaptive MIMO framework adaptively chooses the appropriate rate for the transmission. Simulation results are provided to show the BER and complexity performance of a specific BP detector as well as the throughput performance of the adaptive scheme.
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In this paper, we present a low-complexity algorithm for detection in high-rate, non-orthogonal space-time block coded (STBC) large-multiple-input multiple-output (MIMO) systems that achieve high spectral efficiencies of the order of tens of bps/Hz. We also present a training-based iterative detection/channel estimation scheme for such large STBC MIMO systems. Our simulation results show that excellent bit error rate and nearness-to-capacity performance are achieved by the proposed multistage likelihood ascent search (M-LAS) detector in conjunction with the proposed iterative detection/channel estimation scheme at low complexities. The fact that we could show such good results for large STBCs like 16×16 and 32×32 STBCs from Cyclic Division Algebras (CDA) operating at spectral efficiencies in excess of 20 bps/Hz (even after accounting for the overheads meant for pilot based training for channel estimation and turbo coding) establishes the effectiveness of the proposed detector and channel estimator. We decode perfect codes of large dimensions using the proposed detector. With the feasibility of such a low-complexity detection/channel estimation scheme, large-MIMO systems with tens of antennas operating at several tens of bps/Hz spectral efficiencies can become practical, enabling interesting high data rate wireless applications.
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We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero.
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eng_Latn
| 5,287 |
Outage probabilities and single-hop throughput are two important performance metrics that have been evaluated for certain specific types of wireless networks. However, there is a lack of comprehensive results for larger classes of networks, and there is no systematic approach that permits the convenient comparison of the performance of networks with different geometries and levels of randomness. The uncertainty cube is introduced to categorize the uncertainty present in a network. The three axes of the cube represent the three main potential sources of uncertainty in interference-limited networks: the node distribution, the channel gains (fading), and the channel access scheme (set of transmitting nodes). For the performance analysis, a new parameter, the so- called spatial contention, is defined. It measures the slope of the outage probability in an ALOHA network as a function of the transmit probability p at p = 0. Outage is defined as the event that the signal-to-interference ratio (SIR) is below a certain threshold in a given time slot. It is shown that the spatial contention is sufficient to characterize outage and throughput in large classes of wireless networks, corresponding to different positions on the uncertainty cube. Existing results are placed in this framework, and new ones are derived. Further, interpreting the outage probability as the SIR distribution, the ergodic capacity of unit-distance links is determined and compared to the throughput achievable for fixed (yet optimized) transmission rates.
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This paper deals with the distribution of cumulated instantaneous interference power in a Rayleigh fading channel for an infinite number of interfering stations, where each station transmits with a certain probability, independently of all others. If all distances are known, a necessary and sufficient condition is given for the corresponding distribution to be nondefective. Explicit formulae of density and distribution functions are obtained in the interesting special case that interfering stations are located on a linear grid. Moreover, the Laplace transform of cumulated power is investigated when the positions of stations follow a one- or two-dimensional Poisson process. It turns out that the corresponding distribution is defective for the two-dimensional models.
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ABSTRACTUNC-45A is an ubiquitously expressed protein highly conserved throughout evolution. Most of what we currently know about UNC-45A pertains to its role as a regulator of the actomyosin system...
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eng_Latn
| 5,288 |
In order to achieve a mutiscale representation and texture extraction for textured image, a hierarchical decomposition model is proposed in this paper. We firstly introduce the proposed model which is obtained by replacing the fixed scale parameter of the original decomposition with a varying sequence. And then, the existence and convergence of the hierarchical decomposition are proved. Furthermore, we show the nontrivial property of this hierarchical decomposition. Finally, we introduce a simple numerical method for the hierarchical decomposition, which utilizes gradient decent for energy minimization and finite difference for the associated gradient flow equations. Numerical results show that the proposed hierarchical decomposition is very appropriate for multiscale representation and texture extraction of textured image.
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This article is a companion paper of a previous work where we have developed the numerical analysis of a variational model first introduced by Rudin et al. and revisited by Meyer for removing the noise and capturing textures in an image. The basic idea in this model is to decompose an image f into two components (u + v) and then to search for (u,v) as a minimizer of an energy functional. The first component u belongs to BV and contains geometrical information, while the second one v is sought in a space G which contains signals with large oscillations, i.e. noise and textures. In Meyer carried out his study in the whole ℝ2 and his approach is rather built on harmonic analysis tools. We place ourselves in the case of a bounded set Ω of ℝ2 which is the proper setting for image processing and our approach is based upon functional analysis arguments. We define in this context the space G, give some of its properties, and then study in this continuous setting the energy functional which allows us to recover the components u and v. We present some numerical experiments to show the relevance of the model for image decomposition and for image denoising.
|
Despite the potential benefits of a maritime Internet of Things, a number of issues hinder its realization, including the need for wide area coverage and cost-effectiveness. Toward these needs, a model is first presented for uplink maritime radio communications that hierarchically employ Wi-Fi and cellular links for data transmission from marine user equipments (MUEs) on a ship to a cellular base station with distributed antennas (DAs) along a coastline. Then, the performances are evaluated given in terms of average data rate and outage probability in the hierarchical maritime radio networks. When evaluating the performances, heterogeneous channel characteristics of the hierarchical networks are taken into account in which Rayleigh fading is considered for the MUE-ship links, whereas shadowed-Rician fading is considered for the ship-DA links. Moreover, the effects due to various transmission errors that can be occurred at different communication layers are reflected in determining the quality of service (QoS) requirements of a ship. With the help of authors’ analysis, an antenna selection algorithm is proposed under which the minimum size of a service cloud can be found to support the QoS requirements of MUEs with a ship. The numerical evaluations demonstrate the validity of the proposed algorithm.
|
eng_Latn
| 5,289 |
By applying a rate-distortion approach, we investigate the relationship between the amount of overhead and the system performance from an information-theoretic point of view. Though the purpose of rate-distortion theory is to find a lower bound on lossy source coding problems, the concepts of distortion and rate can be extended to communication performance measures and the quality of feedback overhead, respectively. In this article, we study the overhead-performance tradeoff for a downlink MU-MISO channel system with limited feedback. The required feedback bits for characterizing the channel state information is represented as a function of tolerable rate loss. The proposed method to derive this tradeoff is valid for any number of transmit antennas and users, and can help in designing practical systems where the impact of channel feedback overhead cannot be neglected. Comparing the obtained rate-distortion curves with vector quantization, it can be concluded that, for each user, by feeding back different numbers of bits for different channel power gains, the optimal performance can be achieved.
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In MIMO downlink channels, the capacity is achieved by dirty paper coding (DPQ). However, DPC is difficult to implement in practical systems. This work investigates if, for a large number of users, simpler schemes can achieve the same performance. Specifically, we show that a zero-forcing beamforming (ZFBF) strategy, while generally suboptimal, can achieve the same asymptotic sum-rate capacity as that of DPC, as the number of users goes to infinity. In proving this asymptotic result, we propose an algorithm for determining which users should be active in ZFBF transmission. These users are semi-orthogonal to one another, and when fairness among users is required, can be grouped for simultaneous transmissions to enhance the throughput of fair schedulers. We provide numerical results to confirm the optimality of ZFBF and to compare its performance with that of various MIMO downlink strategies.
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We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero.
|
eng_Latn
| 5,290 |
This paper describes the recent progress of research and development on transmission technologies for Super Hi-Vision (SHV), which is the form of ultrahigh-definition television (UHDTV) with the highest resolution class. The paper covers the transmission systems for SHV program production and satellite broadcasting. For short-haul transmission, an optical digital interface for video equipment was developed. It wavelength-multiplexes eight 10-Gb/s optical signals. It was experimentally confirmed that the transmission distance was at least 2 km, and that a series connection of the interfaces did not severely deteriorate jitter performance. We are also developing a 120-GHz-band wireless contribution short-haul link consisting of three transmitter/receiver pairs. All three pairs transmit and receive a 10.3-Gb/s signal at the same frequency. Experiments showed that transmission with little crosstalk is possible over a distance of 1.25 km when the receiver spacing is 8 m. A long-haul optical contribution link that we developed can transmit a 24-Gb/s SHV signal over a distance of 260 km by using optical amplifiers and no electronic repeaters. An IP network would be a good choice for long-distance links such as an international live contribution link. Several live IP transmissions of compressed video were conducted. Satellite relay transmission and broadcasting technology is also being developed. In particular, we have developed a QPSK/8PSK wide-band modem that uses LDPC and BCH codes. The modem could transmit 251-Mb/s (QPSK) and 677-Mb/s (8PSK) signals and was used in a live SHV satellite-transmission experiment.
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In this paper, we propose a pilot aided carrier frequency offset (CFO) estimation schemes for the Faster-than Nyquist (FTN) transmission system. The FTN transmission would increase the data rate by overlapping the pulse closer than the Nyquist rate. For this reason, there have been some efforts to apply FTN theory to second generation of digital video broadcasting satellite (DVB-S2) standard. However, the FTN produce inter symbol interference (ISI), which would deteriorate the receive performance even in an additive white Gaussian noise (AWGN) channel. In addition, CFO that exist due to transmitter and receiver oscillator mismatch is a major concern in communication system. In this paper, we present the maximum likelihood (ML) CFO estimator for the FTN transmission system. The mean square error (MSE) performance of the CFO estimator utilizing DVB-S2 pilot block sequences is also presented. Through the Monte Calro simulation, the BER performance degradation due to CFO error is investigated both uncoded and coded FTN system.
|
We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero.
|
eng_Latn
| 5,291 |
This paper is concerned with m -ary communication channels (m \geq 2) having intersymbol interference between L time periods (L \geq 2) . Receiver structures are developed for making jointly optimum (minimum probability of error) decisions about L consecutive symbols on the basis of the complete message received. The decision statistics are computed by a sequential procedure, and the number of computations increases only linearly with the message length. The method can be applied to the general problem of making decisions about the states of a discrete-state Markov information source which is observable only through a channel with additive Gaussian or non-Gaussian noise.
|
In this paper, we design capacity-approaching codes for partial response channels. The codes are constructed as concatenations of inner trellis codes and outer low-density parity- check (LDPC) codes. Unlike previous constructions of trellis codes for partial response channels, we disregard any algebraic properties (e.g., the minimum distance or the run-length limit) in our design of the trellis code. Our design is purely probabilistic in that we construct the inner trellis code to mimic the transition probabilities of a Markov process that achieves a high (capacity-approaching) information rate. Hence, we name it a matched information rate (MIR) design. We provide a set of five design rules for constructions of capacity-approaching MIR inner trellis codes. We optimize the outer LDPC code using density evolution tools specially modified to fit the superchannel consisting of the inner MIR trellis code concatenated with the partial response channel. Using this strategy, we design degree sequences of irregular LDPC codes whose noise tolerance thresholds are only fractions of a decibel away from the capacity. Examples of code constructions are shown for channels both with and without spectral nulls.
|
We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero.
|
eng_Latn
| 5,292 |
We propose an approach for online kernel den- sity estimation (KDE) which enables building probability density functions from data by observing only a single data- point at a time. The method maintains a non-parametric model of the data itself and uses this model to calculate the corresponding KDE. We propose an new automatic band- width selection rule, which can be computed directly from the non-parametric model of the data. Low complexity of the modelismaintainedthroughanovelcompressionandrefine- ment scheme. We compare the online KDE to some state-of- the-art batch KDEs on examples of estimating distributions and on an example of classification. The results show that the online KDE generally achieves comparable performance to the batch approaches, while producing models with lower complexity and allowing online updating using only a single observation at a time.
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In this paper we analyze adaptive classification algorithm for digital amplitude-phase modulated signals in flat fading channel with non-Gaussian additive noise, representing possible interference in the channel besides thermal receiver noise. We represent additive noise via normal mixture model, which is able to model various interference scenarios by choosing specific mixture parameters. The adaptive classification algorithm based on application of recursive form of Expectation-Maximization (EM) algorithm for noise parameters estimation is proposed. It allows easy maximum-likelihood classification of the signal of interest using posterior probabilities computed in EM framework. This adaptive approach allows receiver classification algorithm to adapt to time-varying interference scenarios, since recursive form of EM algorithm updates mixture parameters estimates with every new sample obtained. In this paper we analyze the performance of our adaptive classification algorithm for a specific interference scenario expressed with particular interference mixture parameters. We compare its performance to classic optimal maximum-likelihood classification for Gaussian additive noise scenario, and also to algorithm with perfect knowledge of noise parameters.
|
We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero.
|
eng_Latn
| 5,293 |
A secure transmission scheme of anti-eavesdropping on the physical layer in simultaneous wireless information and power transfer (SWIPT) is proposed. Each node in the system is a single-antenna node. There are direct links between eavesdropping node and the source or relay node. The relay work in a full-duplex mode, which uses the amplify-and-forward method to forward the signal. Between the source and relay node is SWIPT mode. The relay collects energy from the received radio frequency (RF) signal and uses it for forwarding. The destination node is also a full-duplex node, sends artificial noise to perform cooperative interference while receiving information to intercept the eavesdropping node. Aiming at maximizing the secrecy rate of the system, the power splitting factor, signal and artificial noise power distribution factor are optimized when the relay adopts the power splitting method. Simulation results suggest that the use of power splitting way and cooperative interference scheme at destination can significantly improve the performance of system.
|
Simultaneous information and power transfer over the wireless channels potentially offers great convenience to mobile users. Yet practical receiver designs impose technical constraints on its hardware realization, as practical circuits for harvesting energy from radio signals are not yet able to decode the carried information directly. To make theoretical progress, we propose a general receiver operation, namely, dynamic power splitting (DPS), which splits the received signal with adjustable power ratio for energy harvesting and information decoding, separately. Three special cases of DPS, namely, time switching (TS), static power splitting (SPS) and on-off power splitting (OPS) are investigated. The TS and SPS schemes can be treated as special cases of OPS. Moreover, we propose two types of practical receiver architectures, namely, separated versus integrated information and energy receivers. The integrated receiver integrates the front-end components of the separated receiver, thus achieving a smaller form factor. The rate-energy tradeoff for the two architectures are characterized by a so-called rate-energy (R-E) region. The optimal transmission strategy is derived to achieve different rate-energy tradeoffs. With receiver circuit power consumption taken into account, it is shown that the OPS scheme is optimal for both receivers. For the ideal case when the receiver circuit does not consume power, the SPS scheme is optimal for both receivers. In addition, we study the performance for the two types of receivers under a realistic system setup that employs practical modulation. Our results provide useful insights to the optimal practical receiver design for simultaneous wireless information and power transfer (SWIPT).
|
We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero.
|
eng_Latn
| 5,294 |
In this paper, we address the problem of coordinated user scheduling for the downlink of a multi-cell distributed antenna system (DAS). With the practical assumption that only large-scale channel state information (CSI) is known at the transmitter, a low-complexity greedy scheduling scheme is proposed. In order to provide fairness among users, the proposed scheme adopts round-robin scheduling within each cell and optimizes the scheduling order for each cell to maximize the minimum ergodic capacity of the users. For each user, the selection transmission scheme (just the distributed antenna element (DAE) with the largest channel gain to the user is selected for transmission) is implemented and each selected DAE transmits with equal power. Simulation results demonstrate that the proposed greedy scheme promises much better performance than that without inter-cell coordination and its performance is quite close to the optimal one. Moreover, by simulations we find that the proposed scheme achieves nearly the same system ergodic sum capacity with the one targeted to maximize the system ergodic sum capacity.
|
We define a generalized distributed antenna system (GDAS) as one that has a total N distributed antenna ports scattered around the cell, each port having L micro-diversity antennas, and all NL antennas have a separate feeder to the base station where the signals are combined. We investigate the effect of macroscopic and microscopic diversity of the proposed system on outage SNR performance and compare with the conventional architectures through analysis and simulation under a composite fading channel. This composite channel approach addresses both macroscopic and microscopic fading, modeled as log-normal and Rayleigh, respectively. These comparative results demonstrate how overall performance is affected by system parameters such as propagation (path loss, shadowing intensity), GDAS parameters (N, L) and signal combining algorithm.
|
Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights.
|
eng_Latn
| 5,295 |
In some real surroundings, signal source localization can more adequately be accomplished with distributed source models. When the signal sources are distributed over an area, we cannot directly use well-known DOA estimation methods, because these methods are established based on the point source assumption. In this paper, we propose a two-dimensional distributed signal source model. Then, we address the estimation of the elevation and azimuth angles of distributed sources based on the proposed model.
|
We consider the challenging problem of joint angle estimation and signal reconstruction for coherently distributed (CD) sources in massive multiple-input–multiple-output (MIMO) systems employing uniform rectangular arrays. A simplified method inspired by the two-dimensional (2-D) unitary estimating signal parameters via rotational invariance technique (ESPRIT) is proposed to estimate both the central angle and the angular spread without the need for a spectrum peak search and covariance matrix matching process. We first approximate the 2-D generalized steering vector expressed as a Schur-Hadamard product by a pair of one-dimensional generalized steering vectors. Then, we obtain two approximate rotational invariance relationships with respect to the central angles of the CD sources using a linear approximation of the individual generalized steering vectors of the azimuth and elevation subarrays. With the aid of this approximate decomposition, a new unitary ESPRIT-inspired algorithm is conceived to automatically pair the 2-D central angle estimations and a novel method capable of bypassing the high-complexity search process is proposed for angular spread estimation. Furthermore, the closed-form approximate Cramer-Rao lower bounds are derived for the estimators of both the central angles and the angular spreads. The complexity of the proposed estimator is also analyzed. Additionally, the orthogonality of the generalized steering vectors is proved, which enables us to propose a low-complexity method to reconstruct the CD signal matrix by replacing the inversion operator with the conjugate transpose operator. The simulation results demonstrate the efficiency of our proposed approach.
|
We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero.
|
eng_Latn
| 5,296 |
This paper investigates the impact of primary transmissions on the performance of a dual-hop bidirectional cognitive radio system. The secondary users (SUs) communicate with each other in an underlay mode with the assistance of amplify-and-forward (AF) relays in the presence of primary users (PUs). Depending on whether there exists interference at the secondary transceivers, originating from the primary transmissions, or there is a possibility of employing the best relay selection technique at the secondary side, two operating cases are considered for the secondary network (SN). For both cases, tight lower bounds on the outage probability (OP) and the average symbol error probability (SEP) are derived in closed form. Moreover, a novel and general closed-form expression for the bit error rate (BER) of $M$ -ary square quadrature amplitude modulation (QAM) for both single- and multiple-relay systems, under additive white Gaussian noise (AWGN) when Gray coded bit mapping is employed, is presented. In addition, we provide an upper bound and closed-form approximate expression for the ergodic capacity (EC). Numerical results provide important insights into the impact of system parameters on performance; for instance, it is demonstrated that, in both cases, under consideration of power constraints on the secondary nodes as dictated by the underlay mode of operation, the SN always achieves the full diversity order similar to the noncognitive counterpart.
|
In this paper, we investigate the performance of cooperative amplify-and-forward (AF) multi-relay networks with relay selection strategy over independent and identically distributed (i.i.d.) Nakagami-m fading channels. In this system we study multiuser cooperative relaying to have a secure transmission from source to destination, since transmitted information may be wiretapped by multiple eavesdroppers. The secrecy outage probability is derived in closed-form using signal-to-noise-ratio statistics, while a useful expression is presented for the asymptotically low outage regime. Our results explicitly demonstrate significant improvement of the secrecy outage probability in the multi-relay scenario.
|
We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero.
|
eng_Latn
| 5,297 |
This work focuses on the fairness in the distribution of the achievable rate per user in a cellular environment where clusters of base stations coordinate their transmissions in the downlink. Block Diagonalization is employed within the cluster to remove interference among users while the interference coming from other clusters remains. The probability distribution of the achievable rate per user shows a perfect match with a Gamma distribution so that a characterization in terms of mean and variance can provide a useful tool for the design of the clusters and the implementation of fairness strategies in a coordinated base station network with Block Diagonalization.
|
A clustered base transceiver station (BTS) coordination strategy is proposed for a large cellular MIMO network, which includes full intra-cluster coordination to enhance the sum rate and limited inter-cluster coordination to reduce interference for the cluster edge users. Multi-cell block diagonalization is used to coordinate the transmissions across multiple BTSs in the same cluster. To satisfy per-BTS power constraints, three combined precoder and power allocation algorithms are proposed with different performance and complexity tradeoffs. For inter-cluster coordination, the coordination area is chosen to balance fairness for edge users and the achievable sum rate. It is shown that a small cluster size (about 7 cells) is sufficient to obtain most of the sum rate benefits from clustered coordination while greatly relieving channel feedback requirement. Simulations show that the proposed coordination strategy efficiently reduces interference and provides a considerable sum rate gain for cellular MIMO networks.
|
We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero.
|
eng_Latn
| 5,298 |
Type-II hybrid ARQ (HARQ) is extended to the nonbinary case, where a shortened half-rate RS code is used in the FEC subsystem instead of a binary BCH code. The RS code is a powerful burst-error-correction code and has the biggest minimum distance among all the codes with the same code length, thereby providing more flexible adaptation. The throughput, reliability, and delay of nonbinary type-II HARQ with M-ary PSK (MPSK) over Rician fading channels are analyzed. Binary HARQ is analyzed also for comparison. The analytical results show that nonbinary HARQ outperforms its binary counterpart with respect to throughput, reliability, and average delay, when the modulation scheme, and the error-detection and error-correction codes are selected properly.
|
This paper presents a new type of hybrid ARQ scheme for error control in data communication systems. The new scheme is based on the concept that the parity-check digits for error correction are sent to the receiver only when they are needed. Normally, data blocks with some parity-check bits for error detection are transmitted. When a data block D is detected in errors, the retransmissions are not simply repetitions of D , but alternate repetitions of a parity block P(D) and D . The parity block P(D) is formed based on D and a half-rate invertible code which is capable of correcting t or fewer errors and simultaneously detecting d (d > t) or fewer errors. When a parity block is received, it is used to recover the originally transmitted data block either by inversion or by decoding operation. The repetitions of the parity block P(D) and the data block D are alternately stored in the receiver buffer for error correction until D is recovered. We show that the proposed hybrid ARQ scheme provides both high system throughput and high system reliability. It is particularly attractive for error control in high-speed data communication systems with significant roundtrip delays, such as satellite channels.
|
Oxygen (O2) is the most abundant element in the Earth’s crust. The oxygen reduction reaction (ORR) is also the most important reaction in life processes such as biological respiration, and in energy converting systems such as fuel cells. ORR in aqueous solutions occurs mainly by two pathways: the direct 4-electron reduction pathway from O2 to H2O, and the 2-electron reduction pathway from O2 to hydrogen peroxide (H2O2). In non-aqueous aprotic solvents and/or in alkaline solutions, the 1-electron reduction pathway from O2 to superoxide (O2 -) can also occur.
|
eng_Latn
| 5,299 |
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