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International Conference on Electric Utility Deregulation and Restructuring and Power Technologies (DRPT)

作者： D.W. Lane C.W. Richter G.B. Sheble Systems Engineering Program Iowa State University Ames IA USA Electrical and Computer Engineering Department Iowa State University Ames IA USA

Under deregulation, the formation of electricity markets is a topic of great interest in the power industry and in financial institutions worldwide. Using derivative financial instruments (including options) becomes important for hedging against uncertainty and managing risk-limiting exposure to adverse market conditions. Black and Scholes' equation is often used to value options, but its validity is questionable due to assumptions that may not hold for electricity, most notably the assumption of log-normally distributed prices for the underlying commodity. In this research, a put options market for electricity is modeled. Adaptive agents trade in this market to maximize profit. They are not forced to use an explicit economic or financial model (e.g., Black-Scholes) in their valuation. A genetic algorithm (GA) is used to find alternate valuations that are used to generate buy and sell signals. The results show that it is possible to evolve profitable valuations for use with buying and selling options in this simple model. Reasons for and implications of this finding (e.g., that Black-Scholes may not be a good method for pricing electricity derivatives) are discussed.

关键词： Cost accounting Electricity supply industry deregulation Electricity supply industry Power industry Instruments Uncertainty Financial management Risk management Equations Power system economics

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Convergence analysis of an oversampled subband adaptive filtering structure with local errors

Convergence analysis of an oversampled subband adaptive filt...

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IEEE International Symposium on Circuits and Systems (ISCAS)

作者： M.R. Petraglia R.G. Alves P.S.R. Diniz COPPE-Program of Electrical Engineering Federal University of Rio de Janeiro Rio de Janeiro Rio de Janeiro Brazil Department of Electrical and Computer Engineering Concordia University Montreal QUE Canada

Subband adaptive filtering has been recently studied by a large number of researchers. The main alternatives are structures with critical sampling and noncritical sampling, and structures that use local errors and global error in the adaptive algorithm. In this paper a theoretical convergence analysis for the case of an oversampled subband adaptive altering structure with local errors is presented. The convergence rate and misadjustment of the algorithm can be estimated from the results of this analysis. computer simulations are presented to illustrate the convergence behavior of the subband adaptive algorithm and to verify the theoretical results.

关键词： Convergence Adaptive filters Finite impulse response filter Filter bank computer errors Sampling methods Adaptive algorithm Algorithm design and analysis computer simulation Prototypes

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Spreadsheet model for MorphoSys RC array

Spreadsheet model for MorphoSys RC array

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IEEE International Conference on Electronics, Circuits and Systems (ICECS)

作者： H. Diab E. Abdennour N. Mansour Department of Electrical and Computer Eng'g Faculty of Engineering and Architecture American University of Beirut Beirut Lebanon Computer Science Program Lebanese American University Beirut Lebanon

ISBN: (纸本)0780365429

This paper introduces reconfigurable computing and MorphoSys, which is a reconfigurable system. It also explains the architecture of its reconfigurable hardware part. Then, it presents two spreadsheet models for the operation of this reconfigurable device. The first spreadsheet performs the modelling through formulas, while the second does it numerically. These spreadsheet models serve as design and debugging tools.

关键词： Registers Hardware computer architecture Application software Reduced instruction set computing Multiplexing Numerical models Debugging Application specific integrated circuits Parallel processing

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On the Perception of Transients: Applying Psychophysical Constraints to Improve Audio Analysis and Synthesis 26

On the Perception of Transients: Applying Psychophysical Con...

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26th International computer Music Conference, ICMC 2000

作者： Wakefield, Gregory H. Heller, Laurie M. Carney, Laurel H. Mellody, Maureen Department of Electrical Engineering and Computer Science University of Michigan Ann ArborMI48109 United States Naval Submarine Medical Research Laboratory GrotonCT06359 United States Hearing Research Center Dept. of Biomedical Engineering Boston University BostonMA02215 United States Applied Physics Program University of Michigan United States

In a psychophysical experiment, a wideband, 4-ms noise is compared with spectrally smoothed versions of the noise. To isolate on the magnitude spectrum, the phase spectrum is controlled by assigning the same random phase spectrum to both the original and smoothed signals. Depending on the choice of phase spectrum, discrimination thresholds for spectral shape vary from a maximum spectral deviation of 2-3 dB to as much as 25 dB. The exact source of this effect remains an open question. However, it suggests that not all transients require the same signal fidelity. Given a proper characterization of the perceptual response, it may be possible to reduce the size of the codebook required to maintain acceptable perceptual results. © 2000 ICMC. All Rights Reserved.

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Prediction of excess noise factor and frequency response for thin avalanche photodiodes

Prediction of excess noise factor and frequency response for...

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IEEE Photonics Conference (IPC)

作者： M.M. Hayat M.A. Saleh Ohhyun Kwon B.E.A. Saleh M.C. Teich Dept. of Electr. & Comput. Eng. Dayton Univ. OH USA Department of Electrical and Computer Engineering Boston University Boston MA USA Electro-Optics Program and the Department of Electrical and Computer Engineering University of Dayton Dayton OH USA

Summary form only given. Recent experimental measurements from InP and InAlAs avalanche photodiodes (APDs) with thin multiplication regions, collected by J.C. Campbell and collaborators at the University of Texas at Austin, show that, for a fixed gain the excess noise factor is significantly lower than that predicted by the conventional McIntyre theory. The observed dependence of the noise on the multiplication-region width cannot be explained using the conventional theory in which the excess noise factor is a function only of the mean gain and the ionization coefficient ratio. In the dead-space-multiplication theory (DSMT), a carrier must travel a certain distance, called the dead space, before gaining sufficient energy for impact ionisation to occur. Because this dead space regularizes the ionisation locations, the randomness of the avalanching mechanism is reduced. For thin multiplication-region APDs, this effect is proportionally higher and thus the noise is lower. We applied the DSMT to the experimental results for GaAs and AlGaAs and more recently for InP and InAlAs APDs. We were able to fit the ionization coefficients associated with devices of various thicknesses, as a function of the electric field, within the confines of a single exponential model.

关键词： Frequency response Avalanche photodiodes Ionization Indium phosphide Gallium arsenide Bandwidth Electronic mail Indium compounds Signal to noise ratio Space exploration

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Classification and estimation of ultrasound speckle noise with neural networks

Classification and estimation of ultrasound speckle noise wi...

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IEEE Symposium on Bioinformatics and Bioengineering (BIBE)

作者： M.P. Wachowiak A.S. Elmaghraby R. Smolikova J.M. Zurada Electrical and Computer Eng. Department University of Louisville Louisville KY USA Computer Science and Engineering Program University of Louisville Louisville KY USA Computer Eng. and Computer Science Department University of Louisville Louisville KY USA

Presents a neural-based approach to classifying and estimating the statistical parameters of speckle noise found in biomedical ultrasound images. Speckle noise, a very complex phenomenon, has been modeled in a variety of different ways: and there is currently no clear consensus as to its precise statistical characteristics. In this study, different neural network architectures are used to classify ultrasound images contaminated with three types of noise, based upon three one-parameter statistical distributions. At the same time: the parameter is estimated. It is expected that accurate characterization of ultrasound speckle noise will benefit existing post-processing methods, and may lead to new refinements in these techniques.

关键词： Ultrasonic imaging Speckle Neural networks Additive noise computer science Parameter estimation computer networks Statistical distributions Adaptive filters Biomedical computing

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A "power-mapping" variable-speed control technique for a constant-frequency conversion system powered by a IC engine and PM generator

A "power-mapping" variable-speed control technique for a con...

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Conference Record of the IEEE Industry Applications Society Annual Meeting (IAS)

作者： M.J. Ryan R.D. Lorenz GE Corporation Research and Development Power Controls Program Niskayuna NY USA Department of Electrical and Computer Engineering University of Wisconsin Madison Madison WI USA

A variable-speed power conversion system is considered where a permanent magnet generator (PMG) driven by an IC engine supplies power to an electronic inverter. The AC voltage from the PMG is typically diode-rectified into a DC link, which is utilized by the inverter to produce constant-frequency, constant-voltage output. These "electronic gensets" can be smaller, lighter and have higher performance than their fixed-speed counterparts with synchronous alternators under field control. Such attributes are attractive for mobile and stand-by power applications. The added flexibility of a variable-speed genset system must be met with suitable techniques for directing the speed at which the engine should operate for a given electrical load. Constraints on torque, speed, and DC link voltage must additionally be met. This paper reviews conventional methods, and presents a new technique utilizing the operating power of the system as an input to a power-speed "map" for the system to follow. Experimental results are included.

关键词： Electric variables control Engines Inverters Voltage Magnetic variables control Power conversion Permanent magnets Power generation Power supplies Diodes

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A Linear Matrix Inequality Approach to The Peak-to-Peak Guaranteed Cost Filtering Design

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IFAC Proceedings Volumes 2000年第14期33卷 29-34页

作者： Reinaldo M. Palhares Pedro L.D. Peres Jaime A. Ramírez Pontifical Catholic University of Minas Gerais Graduate Program in Electrical Engineering Av. Dom José Gaspar 500 Prédio 4 30535-610 Belo Horizonte MG Brazil School of Electrical and Computer Engineering University of Campinas CP 6101 13081-970 Campinas SP Brazil. Department of Electrical Engineering Federal University of Minas Gemis Av. Antônio Carlos 6627 31270-010 Belo Horizonte MG Brazil.

The problem of robust filtering design for uncertain linear systems with guaranteed peak-to-peak performance is addressed in this paper. The uncertain parameters are assumed to belong to convex bounded domains (i.e. polytope type uncertainty). The aim is to design a full-order stable linear filter that minimizes the worst-case peak value of the filtering error output signal with respect to all magnitude bounded noise inputs, in such way that the filtering error system remains robustly stable. The minimization provides an upper bound to the L ∞ induced gain ( ℓ ∞ for discrete-time systems) of the filtering error system. The conditions for the existence of such robust filter are provided in terms of linear matrix inequalities, allowing the use of standard convex optimization procedures to solve the problem. Both continuousand discrete-time systems are considered. The formulation presented is illustrated by examples.

关键词： Robust Estimation Filter Design Uncertain Linear Systems Peak-to-Peak Gain Linear Matrix Inequalities

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Biophysical and spectral characteristics of cool- and warm-season grasslands under three land management practices in Eastern Kansas

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Natural Resources Research 2000年第4期9卷 321-331页

作者： Guo, Xulin Price, Kevin P. Stiles, James M. Kansas Applied Remote Sensing Program (KARS) Department of Geography University of Kansas Lawrence KS 66045 2335 Irving Hill Road United States Radar Systems and Remote Sensing Laboratory (RSL) Department of Electrical Engineering and Computer Science University of Kansas Lawrence KS 66045 2335 Irving Hill Road United States Lawrence KS 66045 2335 Irving Hill Road United States

Grasslands are the largest of the Earth's four major vegetation types and are among the most agriculturally productive lands. Grassland management practices alter biophysical factors, such as plant species composition, soil structure and chemistry, and primary productivity. Large-scale changes in land management practices can have significant impacts on available natural resources, therefore impacting a regional socioeconomics. For these reasons, an improved understanding of the geographic distribution of changing land management practices and how these changes affect grassland biophysical characteristics of an area is critical to improve land use planning and practices. This study investigated the spectral characteristics, as measured using satellite remotely sensed data, of three land management practices [grazing, haying, and management under Conservation Reserve program (CRP)] on areas dominated by cool- and warm-season grasslands. The satellite imagery was acquired in May, July, and September in 1997 over Douglas County, Kansas. Biomass, vegetation cover, and species richness data were collected around the satellite overflight periods. Our results indicate that the biophysical characteristics and spectral reflectances are significantly different among the three management practices over cool- and warm-season grasslands. Interestingly, sites grazed by livestock had the highest species richness and the highest forb cover, although the total cover is almost the same as the other practices, and they have the highest near-infrared reflectance throughout the growing season. © 2000 International Association for Mathematical Geology.

关键词： Landsat Tallgrass prairie Thematic Mapper (TM)

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Optimizing dual threshold shocks with right- and left-ventricular electrodes: simulating defibrillation with a human thorax model

Optimizing dual threshold shocks with right- and left-ventri...

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Annual International Conference of the IEEE engineering in Medicine and Biology Society (EMBC)

作者： N.R. Kramer J.L. Manfra A.L. de Jongh S.J. Hahn B.H. KenKnight F.J. Claydon Joint Program in Biomedical Engineering University of Memphis and University of Tennessee Memphis TN USA Cardiac Rhythm Management Guidant Corporation Saint Paul MN USA Department of Electrical and Computer Engineering University of Houston Houston TX USA

ISBN: (纸本)0780364651

This research focuses on developing new implantable cardioverter defibrillator (ICD) dual lead configurations that reduce the defibrillation threshold (DFT) energy by delivering a second threshold shock in the area where the conventional shock's electric field is weakest. The objective of this study is to optimize electrode placements for lead systems including left-ventricular (LV) electrodes. A physiologically realistic 3D finite element model of the human thorax is employed to compute DFTs. The lead configurations investigated consist of a conventional lead system (TRIAD/sup TM/, Guidant Corporation) and additional LV shocking electrodes placed in the apical and basal portion of the posteriolateral coronary vein or directly within the TRIAD system's weak field region. The LV electrodes measure 50 mm in length and 1 mm in diameter. The computed DFT energy for the TRIAD is 6.2 J, falling within one standard deviation of the mean DFT reported in clinical studies using the TRIAD leads. LV leads located in the apical and basal portion of the posteriolateral coronary vein result in a DFT of 3.1 J, a 50% reduction from the TRIAD alone. LV leads placed in the anterior, middle, and posterior TRLAD weak field result in a DFT of 2.9 J, 2.7 J., and 3.5 J, respectively, corresponding to a 44-56% reduction in DFT from the TRIAD. The results indicate that an additional electrode placed in the proximity of the TRIAD weak field is just as effective in reducing DFTs as one placed directly within the weak field.

关键词： Electric shock Electrodes Defibrillation Humans Thorax Veins Cardiology Finite element methods Torso Biological system modeling

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