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CreatorTitleDescriptionSubjectDate
201 Furse, Cynthia M.MIMO transmission equationMultiple-input, multiple-output (MIMO) antenna systems such as the one depicted in Fig. 1 offer capacity benefits over their single-input, single-output (SISO) counterparts [1], thus attracting considerable current research. MIMO performance depends on a wide range of parameters [1] including radia...2008-07
202 Mathews, V. JohnAdaptive polynomial filtersWhile linear filter are useful in a large number of applications and relatively simple from conceptual and implementational view points. there are many practical situations that require nonlinear processing of the signals involved. This article explains adaptive nonlinear filters equipped with polyn...1991
203 Furse, Cynthia M.Faster than fourier: ultra-efficient time-to-frequency-domain conversions for FDTD simulationsThis tutorial compares several methods of converting from the time to the frequency domain for FDTD simulations. Applications include calculations of field or power distributions, antenna impedance, and radiation patterns. The traditional Fourier transform methods are compared to two methods based o...FDTD simulations; FDTD methods; Finite-difference time-domain; Computation time; Frequency domain analysis; Time domain analysis; Discrete Fourier transform2000-01-01
204 Mathews, V. JohnAn analytical model of the perceptual threshold function for multichannel image compressionABSTRACT The human observer is often the final judge of the quality of compressed images. One way to design a compression system that attempts to reduce or eliminate subjective distortions in the coded images is to incorporate a perceptual threshold function model into the compression system. The...1998
205 Mathews, V. JohnTracking analysis of the sign algorithm in nonstationary environmentsThis paper presents a tracking analysis of the adaptive filters equipped with the sign algorithm and operating in nonstationary environments. Under the assumption that the nonstationarity can be modeled using a random disturbance, it is shown that the long-term time average of the mean-absolute erro...1990
206 Stevens, KennethCAD directions for high performance asynchronous circuitsThis paper describes a novel methodology for high performance asynchronous design based on timed circuits and on CAD support for their synthesis using Relative Timing. This methodology was developed for a prototype iA32 instruction length decoding and steering unit called RAPPID ("Revolving Asynchro...1999
207 Stringfellow, Gerald B.; Williams, Clayton C.Atomic ordering of GaInP studied by Kelvin probe force microscopyThe atomic ordering of GaInP has been established and studied by a variety of methods, including transmission electron microscopy, cathodoluminescence, and photoluminescence. In this work, a Kelvin probe force microscope _x0002_KPFM_x0003_ has been employed to image several GaInP samples previous...Cathodoluminescence; Photoluminescence; Surface morphology1995
208 Mathews, V. JohnIdentification of nonlinear, memoryless systems using chebyshev nodesABSTRACT This paper describes an approach for identification of static nonlinearities from input-output measurements. The approach is based on minimax approximation of memoryless nonlinear systems using Chebyshev polynomials. For memoryless nonlinear systems that are finite and continuous with fini...2005
209 Mathews, V. JohnHowling suppression in hearing aids using least-squares estimation and perceptually motivated gain controlABSTRACT Howling is a significant problem even in digital hearing aids equipped with adaptive feedback cancellation. Among the many causes of howling is the inability of the adaptive filter to track rapid changes in the feedback path. Many systems use howling detectors to detect the start of howlin...2006
210 Stevens, KennethModeling and verifying circuits using generalized relative timingWe propose a novel technique for modeling and verifying timed circuits based on the notion of generalized relative timing. Generalized relative timing constraints can express not just a relative ordering between events, but also some forms of metric timing constraints. Circuits modeled using gener...2005
211 Stringfellow, Gerald B.Use of Nitrogen to disorder GaInPSignificant changes in microstructure, surface structure, and alloy composition have been observed in GaInP with the addition of nitrogen. These effects occur due to surface changes induced by small concentrations of nitrogen. Transmission electron microscopy and photoluminescence experiments indica...Nitrogen; Alloys; Transmission2004
212 Myers, Chris J.Verification of timed circuits with failure directed abstractionsThis paper presents a method to address state explosion in timed circuit verification by using abstraction directed by the failure model. This method allows us to decompose the verification problem into a set of subproblems, each of which proves that a specific failure condition does not occur. To...2003
213 Mathews, V. JohnA new model of perceptual threshold functions for application in image compression systemsThis paper discusses the development of a perceptual threshold model for the human visual system. The perceptual threshold functions describe the levels of distortions present at each location in an image that human observers can not detect. Models of perceptual threshold functions are useful in ima...1995
214 Stevens, KennethAlgorithms for MIS vector generation and pruningIgnoring the effect of simultaneous switching for logic gates causes silicon failures for high performance microprocessor designs. The main reason to omit this effect is the run time penalty and potential over-conservatism. Run times are directly proportional to the vector sizes. Efficient algorithm...2006
215 Stringfellow, Gerald B.Organometallic vapor phase epitaxial growth of AlGaInPAlx Ga,, In, _ x _ y P with x + y = 0.51, lattice matched to the GaAs substrate, has been grown by organometaUic vapor phase epitaxy. The simple, horizontal, IR heated system operates at atmospheric pressure using the reactants TMA1, TMGa, TMln, PH3, and K2. Alloys giving room temperature, band edge...Liquid phase epitaxial growth; LPE; Alloys; Surface morphology1985
216 Furse, Cynthia M.Statistical comparison of capacity predictions for realistic MIMO channelsThe impact of antenna polarization on channel capacity is explored in multiple-input, multiple-output (MIMO) systems. An idealized polarization model involving branch power rations (BPR's) and channel cross-coupling is incorporated into channel-specific capacity calculations. Results are compared f...2007-01-01
217 Myers, Chris J.; Stevens, KennethAn asynchronous instruction length decoderAbstract-This paper describes an investigation of potential advantages and pitfalls of applying an asynchronous design methodology to an advanced microprocessor architecture. A prototype complex instruction set length decoding and steering unit was implemented using self-timed circuits. [The Revolvi...2001
218 Stringfellow, Gerald B.Step structure and ordering in GaInPPresents information from an experiment on the step structure and ordering in GalnP. Information on the step spacing and degree of order in the epitaxial layers; Details on the experiment; Results from the experiment.Physics; Ordering; Steps1998
219 Stringfellow, Gerald B.Radiative pair transitions in p-type ZnSe:Cu crystalsShallow levels with an ionization energy of 0.012 eV play an important role in the photoelectronic properties of p-type ZnSe:Cu crystals. These levels exhibit the characteristics of the higher-lying member of an imperfection pair involved in luminescence emission, as well as of a trap determining lo...Ionization energy; Luminescence emission; Crystals1968
220 Stevens, KennethRadiation hardening by design of asynchronous logic for hostile environmentsA wide range of emerging applications is driving the development of wireless sensor node technology towards a monolithic system-on-a-chip implementation. Of particular interest are hostile environment scenarios where radiation and thermal extremes exist. Radiation hardening by design has been recogn...2009
221 Stevens, KennethScalable asynchronous hardware protocol verification for compositions with relative timingCorrect interaction of asynchronous hardware protocols requires verification. Performance and power of asynchronous hardware circuits and protocols can be vastly improved by modifying them with judicious application of timing constraints. A methodology is presented for verifying larger asynchronous ...2010
222 Mathews, V. JohnAn efficient algorithm for joint estimation of differential time delays and frequency offsetsABSTRACT This paper introduces an efficient algorithm that jointly estimates differential time delays and frequency offsets between two signals. The approach is a two-step procedure. First, the differential frequency offsets are estimated from measurement of the autocorrelation functions of the rec...1992
223 Harrison, Reid R.MDAC synapse for analog neural networksEfficient weight storage and multiplication are important design challenges which must be addressed in analog neural network implementations. Many schemes which treat storage and multiplication separately have been previously reported for implementation of synapses. We present a novel synapse c...Multiplying digital-to-analog converter; MDAC synapse; Analog neural networks2004-01-01
224 Furse, Cynthia M.Take a Stand: Speaking about RF SafetyTell your students at the beginning of the semester that they need to prepare a speech and deliver it before an off-campus audience, and they will not exactly be leaping out of their seats with joy. Remind them a week in advance that their speech is coming up, and you will inevitably have a student ...Radio frequency safety; RF safety2004-12
225 Myers, Chris J.Stochastic cycle period analysis in timed circuitsThis paper presents the stochastic cycle period as a performance metric for timed asynchronous circuits. The stochastic cycle period is a sum of weighted delays whose value represents the expected delay of a single cycle in the specification. Each weight denotes the amount of time a delay contribute...1999
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