Social utility Functions-part I: theory

The dominant approaches to utility-based multiagent decision theory rely on the premise of individual rationality-the doctrine that each individual is committed to achieving the best outcome for itself, regardless of the effect doing so has on others. This fundamentally asocial concept is the basis of conventional von Neumann-Morgenstern (vN-M) utilities but is inadequate to characterize truly cooperative artificial systems. Social utility functions differ from conventional vN-M utilities in that they are functions of multiple decision-maker preferences, rather than actions, and thus permit individuals to expand their spheres of interest beyond the self. A logical basis for coherent reasoning in multiagent environments must obey exactly the same desiderata as do multivariate probability functions. By taking a dual utilities approach (one to account for effectiveness and one to account for efficiency), a new game-theoretic structure, called satisficing games, provides a decision-making procedure that accounts for both individual and group interest and presents a framework for the design of sophisticated multiagent societies.     

Evaluation of three-level rectifiers for low-voltage utility applications

This paper evaluates the benefits of three-level topologies as alternatives to two-level topologies in low-voltage converters primarily operated in rectifier mode. The main evaluation aspects are input filter size, semiconductor losses, maximum switching frequency, part count, initial cost, and life cycle cost. Semiconductor loss characteristics of various three-level topologies are discussed. A detailed converter comparison is based on a 100-kW 400-V/sub rms/ rectifier using commercially available Si insulated gate bipolar transistor modules.     

Large static converters for industry and utility applications

The emergence of high-power semiconductor devices such as insulated-gate bipolar transistors (IGBTs) or injection-enhanced gate transistors (IEGTs) and gate-commutated turn-off (GCT) thyristors or integrated gate-commutated thyristors (IGCTs) enables large static converters to expand into utility and industry applications. For instance, a ±80 kV 50 MW HVDC transmission system based on a string of many IGBTs connected in series was commissioned in 1999. This paper describes the present status of large static converters, with focus on their applications to utility and industry. The applications discussed are: HVDC transmission system, UPFC, flywheel energy storage system, pumped hydro plant adjustable speed generator, active filters for power conditioning, and steel mill drives. The paper also describes their future prospects and directions in the 21st century, including the personal views and expectations of the author     

Viability of active EMI filters for utility applications

The application of active circuitry to increase the performance per size and cost of utility-side EMI filters is considered. The major problems are power line frequency (60 Hz) rejection and the compensation of the feedback loop, which is influenced by the wide-ranging utility impedance. While analysis and simulations show that these problems prevent the practical application of active filtering to power supplies switching at around 75 kHz, results at 450 kHz demonstrate potential for substantial improvement of EMI filters for switching frequencies of a few hundred kHz, although with the cost of a complex compensation     

Phased arrays-part II: implementations, applications, and futuretrends

In part I of this paper, we presented the basic architectures and theory for passive and active phased arrays. Here, we review array implementation, state-of-the-art applications, and identify future trends in phased-array technology     

A perceptually motivated three-component image model-part II:applications to image compression

For past I see ibid., vol.4, no.4, p.405 (1995). The use of the image model of Part I is investigated in the context of image compression. The model decomposes the image into a primary component that contains the strong edge information, a smooth component that represents the background slow-intensity variations, and a texture component that contains the textures. The primary component, which is known to be perceptually important, is encoded separately by encoding the intensity and geometric information of the strong edge brim contours. Two alternatives for coding the smooth and texture components are studied: entropy-coded adaptive DCT and entropy-coded subband coding. It is shown via simulations that the proposed schemes, which can be thought of as a hybrid of waveform coding and feature-based coding techniques, result in both subjective and objective performance improvements over several other image coding schemes and, in particular, over the JPEG continuous-tone image compression standard. These improvements are especially noticeable at low bit rates. Furthermore, it is shown that a perceptual tuning based on the contrast-sensitivity of the human visual system can be used in the DCT-based scheme, which in conjunction with the three-component model, leads to additional subjective performance improvements.     

Ferrites for linear applications II?Performance requirements

The final installment of this article focuses on the applications and performance requirements of soft ferrite materials. Basic devices employing ferrites include inductors for FDM filters, wide-band and pulse transformers, and high-frequency power transformers. In the typical modern television receiver a total of about 0.6 kg of ferrite cores is used in a variety of applications, such as line output transformers, deflection yokes, and convergence systems.     

Recollections of pre-world war II magnetrons and their applications

The magnetron development work at Westinghouse Research Laboratories in the years 1929 to 1934 and at RCA from 1934 to 1938 is described. The Westinghouse work led to internal-circuit magnetrons with powers on the order of 1W at 9-cm wavelength, and detectable power down to 1.6 cm. A complete microwave relay system using searchlight mirrors was built and demonstrated at the Chicago "Century of Progress" exhibition in 1933-1934. Later work at RCA was directed to longer wavelength in the 60-cm range, where powers of 100 W were obtained. These were CW tubes: the need for pulsed tubes for radar was never disclosed to the tube designers at that time.     

Premo: an emerging standard for multimedia presentation. II.Specification and applications

For pt.I see ibid., p.83-9, Fall, 1996. The article gives an overview of the Premo (Presentation Environment for Multimedia Objects) standard. The first part presented the motivation behind Premo's development and gave a general overview of the standard's technical content. The interested reader may also refer to the Premo document itself, as well as the various ISO documents and other publications. A World Wide Web site is presented which provides a good starting point to navigate through and access all available documents     

SMAQ: a measurement-based tool for traffic modeling and queuinganalysis. II. Network applications

For pt. I see ibid. p.56-65 (1998). SMAQ is a measurement-based tool for integration of traffic modeling and queuing analysis. It can be used in a variety of network design areas. For instance, it can be used as a traffic generator to generate various traces for network testing. It also provides numerical solutions of the queue length and loss rate performance for transport of multimedia traffic. Several application modules are built into the tool for the evaluation of statistical multiplexing, buffer dimensioning, and link bandwidth allocation. Other examples include the evaluation of traffic shaping, local-congestion control, and the modeling of wireless channel dynamics. As one will find, the SMAQ tool indeed provides a solution technique for network engineers to solve many of the current design issues     

Nonlinear electro-thermal modeling and field-simulation of OLEDs for lighting applications II: Luminosity and failure analysis

In recent years great effort has been put into development of lighting purpose Organic Light Emitting Diodes (OLEDs) worldwide. Among many concerns of developers is heat-removal from the thin film structure of the active layers of OLEDs which are typically realized on low thermal conductivity substrates such as glass or polymer foils. The other issue is to provide the OLEDs with transparent, yet high electrical conductivity electric power supply structure, therefore metallic shunting grids are added to the layer stack of OLEDs. These two major issues necessitate self-consistent electro-thermal simulation of large area OLEDs in which the temperature dependent I–V characteristics of the light emitting polymer layers are also considered. Our first article discussed the details of the algorithmic fundamentals of our nonlinear electro-thermal field solver. This second paper presents the new, temperature dependent radiance and luminance distribution map calculation extension of the algorithm. Using this feature the inhomogeneity of large area OLEDs in free convection environment can be estimated; such calculations for glass-based research OLED samples are also presented. Because of the operational degradation of the OLED, non-emissive “dark” spots can appear. Cause of these spots can be e.g. manufacturing problem, damage of the surface protection, etc. Electro-thermal and luminance simulation of this failure type is demonstrated and is compared with measured results. Thermal runaway as the possible physical phenomenon behind the appearances of dark spots is proved by simulations.     

The cumulant theory of cyclostationary time-series. II. Developmentand applications

For pt.I see ibid., vol.42, no.12, p.3387-3408 (1994). The development of the theory of nonlinear processing of cyclostationary time-series that is initiated in Part I is continued. A new type of cumulant for complex-valued variables is introduced and used to generalize the temporal and spectral moments and cumulants for cyclostationary time-series from real-valued to complex-valued time-series. The relations between the temporal and spectral moments and cumulants at the inputs and outputs of several signal processing operations are determined. Formulas for the temporal and spectral cumulants of complex-valued pulse-amplitude-modulated time-series are derived. Estimators for the temporal moments and cumulants and for the cyclic polyspectra are presented and their properties are discussed. The performance of these estimators is illustrated by several computer simulation examples for pulse-amplitude-modulated time-series. The theory is applied to the problems of weak-signal detection and interference-tolerant time-delay estimation     

The utility of performance measures: production manager'sperceptions

The utility of a set of 42 measures of subunit performance to 155 production managers is reported. The measures were derived from interviews conducted with practicing managers. The measures were rank ordered, based on their mean scores, and specific patterns arose from the mean orderings. The relative usefulness of these measures and the underlying types of information required for their construction can provide guidance to those engineers or production managers endeavoring to develop or improve an evaluation strategy for manufacturing subunits     

A physical compact model of DG MOSFET for mixed-signal circuit applications - part II: Parameter extraction

For pt. see ibid., vol. 50, no. 10, p. 2135 (2003). Based on the physical double-gate MOSFET model described in Part I, we present a systematic parameter extraction methodology that avoids parameter interdependence between different physical effects whenever possible. Several extraction schemes are compared for precise modeling of small-signal and large-signal characteristics. The physical model and the extraction methodology are verified through the reproduction of the simulated drain current, incremental drain resistance, and transconductance per unit current, which are parameters of particular interest to mixed-signal circuit designs.     

Data hiding in image and video .II. Designs and applications

For pt. I see ibid., vol.12, no.6, p.685-95 (2003). This paper applies the solutions to the fundamental issues addressed in Part I to specific design problems of embedding data in image and video. We apply multilevel embedding to allow the amount of embedded information that can be reliably extracted to be adaptive with respect to the actual noise conditions. When extending the multilevel embedding to video, we propose strategies for handling uneven embedding capacity from region to region within a frame as well as from frame to frame. We also embed control information to facilitate the accurate extraction of the user data payload and to combat such distortions as frame jitter. The proposed algorithm can be used for a variety of applications such as copy control, access control, robust annotation, and content-based authentication.     

Linear time-variant transformations of generalized almost-cyclostationary signals.II. Development and applications

For pt. I see ibid., vol.50, no.12, p.2947-61 (2000). In Part I, the problem of the linear time-variant (LTV) filtering is addressed in the fraction-of-time (FOT) probability framework. The adopted approach, which is an alternative to the classical stochastic one, provides a statistical characterization of the systems in terms of functions that can be estimated by a single time-series. The analysis is carried out with reference to the wide class of the generalized almost-cyclostationary (GACS) signals, which includes, as a special case, the class of the almost-cyclostationary (ACS) signals. Examples of applications and developments of the theory introduced in Part I are presented here in Part II. Specifically, the countability of the set of the output cycle frequencies is studied with reference to linear time-variant systems for both ACS and GACS not containing any ACS component input signals. Thus, the linear almost-periodically time-variant filtering and the product modulation are considered in detail. Moreover, several Doppler channel models are analyzed. In all these examples, it is shown that the FOT probability approach allows one to characterize the system and its output in terms of statistical functions that can be measured by a single time-series. Furthermore, the usefulness of considering the linear filtering problem within the class of the GACS signals is clarified, and several pitfalls arising from continuing to adopt for the observed time-series the ACS model when an increase in the data-record length makes the GACS model more appropriate are pointed out.     

Doubling the engineer's utility

The big challenge for military forces and their industrial supporters since the end of the cold war is how to convert technologies once viewed as exclusively military to serve civilian ends as well. The authors discuss a case of dual use in which a rigorous military method for designing complex computer systems appears suited to complicated civilian projects. The method is supported by a new language, CaRT-Spec, which is application independent and therefore suitable for both military and civilian applications