This book presents the established fundamentals in the area of active sound and vibration control (ASVC) as well as exploring the new and emerging technologies and techniques. There has been a considerable amount of effort devoted to the development and realisation of methodologies for the control of sound and vibration, and this book covers the latest theoretical, algorithmic and practical applications including: noise control in 3D propagation, adaptive algorithms, prediction, processing and tuning, neuro-active control, control of microvibrations, and noise reduction in locomotives and vehicles. Topics discussed include multichannel active noise control, adaptive harmonic control, model-free iterative tuning, model-based control design for active vibration control (AVC), ASVC using neural networks, genetic algorithms for ASVC systems, and active noise control (ANC) around the human head. The authors also discuss active control of microvibrations, vibration control of manipulators, and techniques of real-time processing. This book will be essential reading for electrical, mechanical and control engineers, designers and researchers, interested in noise and vibration control.
Adaptive arrays are a radical departure from conventional thinking in antenna design, offering substantial improvements in performance over fixed pattern antennas in environments that include severe interference and jamming. They achieve this because they are designed to steer nulls automatically at noise sources of unknown or variable direction and generally to modify their beampatterns to optimise performance. Adaptive array processing is applicable in most systems that exploit wave propagation; typical uses being radar, active and passive sonar, radio communication links, and radio monitoring.
Although sensors and hardware for different applications vary, the same optimality criteria are used throughout and similar algorithms may be employed. This book develops the concepts underlying the design of adaptive arrays from first principles and is directed at research workers and designers whose mathematical background requires refurbishment in the special techniques that have accumulated around the field, often to the obscuration of the simple basic ideas.
The topics treated include: single multiple null steering; derivation of the weighting coefficients in an array that maximises signal to noise ratio; online algorithms for achieving these coefficients using gradient methods based on correlators and coefficient peterbation; direct estimation of optimum coefficients by covariance matrix inversion and recursive techniques; prevention of null steering at the desired source and control over the main lobe shape; minimisation of the number of variable coefficients in suboptimal implementations.
Control often follows predictions: predictive control has been highly successful in producing robust and practical solutions in many real-life, real-time applications. Adaptive prediction covers a variety of ways of adding 'intelligence' to predictive control techniques. Many different groups, with widely varying disciplinary backgrounds and approaches, are tackling the same problem from different angles; these groups are sometimes unaware of alternative approaches from other disciplines.
This book attempts to give a unified and comprehensive coverage of the principles and methods that these groups have developed. It avoids basing its descriptions on very complex mathematical formulations but still gives a rigorous exposure to the subject, and illustrates the theory with many practical examples. It is chiefly aimed at students, researchers and practitioners, but will also be accessible to the non-specialist.
Adaptive Sampling with Mobile WSN develops algorithms for optimal estimation of environmental parametric fields. With a single mobile sensor, several approaches are presented to solve the problem of where to sample next to maximally and simultaneously reduce uncertainty in the field estimate and uncertainty in the localisation of the mobile sensor while respecting the dynamics of the time-varying field and the mobile sensor. A case study of mapping a forest fire is presented. Multiple static and mobile sensors are considered next, and distributed algorithms for adaptive sampling are developed resulting in the Distributed Federated Kalman Filter. However, with multiple resources a possibility of deadlock arises and a matrix-based discrete-event controller is used to implement a deadlock avoidance policy. Deadlock prevention in the presence of shared and routing resources is also considered. Finally, a simultaneous and adaptive localisation strategy is developed to simultaneously localise static and mobile sensors in the WSN in an adaptive manner. Experimental validation of several of these algorithms is discussed throughout the book.
This book presents the theory of adjoint sensitivity analysis for high frequency applications through time-domain electromagnetic simulations in MATLAB®. This theory enables the efficient estimation of the sensitivities of an arbitrary response with respect to all parameters in the considered problem. These sensitivities are required in many applications including gradient-based optimization, surrogate-based modeling, statistical analysis, and yield analysis.
Using the popular FDTD method, the book shows how wideband sensitivities can be efficiently estimated for different types of materials and structures, and includes plenty of well explained MATLAB® examples to help readers absorb the content more easily and to make the theory more understandable to the broadest possible audience. Topics covered include a review of FDTD and an introduction to adjoint sensitivity analysis; the adjoint variable method for frequency-independent constitutive parameters; sensitivity analysis for frequency-dependent objective functions; transient adjoint sensitivity analysis; adjoint sensitivity analysis with dispersive materials; adjoint sensitivity analysis of anisotropic structures; nonlinear adjoint sensitivity analysis; second-order adjoint sensitivities; and advanced topics.
This book provides a unified, practically-oriented treatment to many constrained control paradigms. Recently proposed control strategies are unified in a generalised framework to deal with different kinds of constraints. The book's solutions are based on reference conditioning ideas implemented by means of supervisory loops, and they are complementary to any other control technique used for the main control loop. Although design simplicity is a book priority, the use of well established sliding mode concepts for theoretical analysis make it also rigorous and self-contained.
The first part of the book focuses on providing a simple description of the method to deal with system constraints in SISO systems. It also illustrates the design and implementation of the developed techniques through several case studies. The second part is devoted to multivariable constrained control problems: improving system decoupling under different plant or controller constraints, and reducing the undesired effects caused by manual-automatic or controller switching. The key aim of this book is to reduce the gap between the available constrained control literature and industrial applications.
Historically, electromagnetics and complex circuit modelling existed as separate disciplines, each with their own tools, models and even languages. More recently, however, the emergence of very high-speed digital circuits and pressure on the telecommunications market to move towards microwave and millimetre wave bands are increasing the need to find ways to combine the two fields.
The consumer market demands low cost mass production devices operating at higher frequencies where the finite dimensions of the circuits with respect to wavelength can no longer be ignored. Similarly, integrated planar microwave circuits pose new modelling challenges, as neither conductors nor dielectrics can be considered as ideal at these frequencies and, consequently, most techniques and formulas developed over the past twenty years for dealing with ideal thin conductors no longer model the physical reality.
These challenges are the main subject of this book which investigates analytical techniques encompassing the linear modelling of passive and active - in particular FET - structures. This timely book was primarily conceived as a bridge between the mathematical abilities of the pure EM theorist and those of the FET circuit modeller. However the resulting text will be of equal benefit to researchers in microwave and millimetric components and as a textbook for specialised courses.
With contributions from leading names in the area, this book expands on several aspects of computational electromagnetics and advanced numerical techniques with cutting-edge applications, and proposes guidelines for the optimised design of several contemporary structures. As well as standard techniques, the authors cover many other time-domain schemes, including ADI, polynomial chaos, stochastic methods, enhanced curvilinear implementations and novel GPU/CUDA realisations. For researchers in electromagnetics and related areas.
The term 'advanced robotics' came in the 1980s to describe the application of advanced sensors and new developments in cognitive science and artificial intelligence to the traditional robot. Today, advanced robots have come far beyond the limitations of the crude 'pick-and-place' machines of the 1980s assembly line, and have a vast range of applications in manufacturing, construction and health care, as well as hostile environments such as space, underwater and nuclear applications.
This book provides an essential overview of developments in the basic technologies, looking at recent applications and highlighting a number of advanced concepts and procedures that may influence future developments. The emphasis is on developments in Europe, although the book is also relevant to activities in the USA, Japan and elsewhere. With such a wide and dynamic field, it does not attempt to provide a comprehensive guide; rather, it addresses many key elements of the technology to furnish a complete introduction for both postgraduate students and practising engineers attracted to the challenges of the domain.
Although existing nanometer CMOS technology is expected to remain dominant for the next decade, new non-classical devices are being developed as the potential replacements of silicon CMOS, in order to meet the ever-present demand for faster, smaller, more efficient integrate circuits.
Many new devices are based on novel emerging materials such as one-dimensional carbon nanotubes and two-dimensional graphene, non-graphene two-dimensional materials, and transition metal dichalcogenides. Such devices use on/off operations based on quantum mechanical current transport, and so their design and fabrication require an understanding of the electronic structures of materials and technologies. Moreover, new electronic design automation (EDA) tools and techniques need to be developed based on integrating devices from emerging novel material-based technologies.
The aim of this book is to explore the materials and design requirements of these emerging integrated circuit technologies, and to outline their prospective applications. It will be useful for academics and research scientists interested in future directions and developments in design, materials and applications of novel integrated circuit technologies, and for research and development professionals working at the cutting edge of integrated circuit development.
Advances in Cognitive Systems
Samia Nefti The Institution of Engineering and Technology, 2010 Library of Congress BF311.A317 2010 | Dewey Decimal 153
This book has been inspired by the portfolio of recent scientific outputs from a range of European and national research initiatives in cognitive science. It presents an overview of recent developments in cognition research and unites the various emerging research strands within a single text as a reference point for progress in the subject. It also provides guidance for new researchers on the breadth of the field and the interconnections between the various research strands identified here.
Advances in Cognitive Systems brings together a wide range of material from leading workers in the field as well as the outputs from research groups around the world, covering the two principal cognition paradigms of cognitivism and emergence. Furthermore, it suggests some interesting lines of thought about the challenges and opportunities for future work in the field and for promoting the various research agendas highlighted within. This compilation will be of interest not only to those working in the fields of computer science and AI but also to psychologists, neural scientists, researchers in information science, and engineers involved in the development of advanced robotics, mechatronic systems and HCI systems.
This title covers recent progress in advanced analytical and associated numerical methods applied to problems arising in all areas of electromagnetics. It focuses on applying advanced or novel mathematical techniques to produce analytical solutions or effective analytical-numerical methods for computational electromagnetics addressing more general problems. Each chapter outlines its topic; discusses its scientific context and importance; describes approaches and results; and ends by describing which techniques work best for different problems.
Microwave filters are the basic building blocks of communication systems. These filters, having reliable and scalable filter topologies with and without tunable properties, are capable of controlling different frequency bands as well as their fractional bandwidth to meet different system needs. There have been significant advances in the synthesis and physical realisation of microwave filter networks, and the design and applications for communication systems.
This edited book presents recent advances in planar filter design. It covers a wide range of different design types, technologies and applications for wireless, microwave, communications and radar systems.
Written by academic professionals from around the world, this book offers a global perspective on the latest developments in this area. Advances in Planar Filters Design is essential reading for R&D engineers, specialists, research students and academics working on the topic of RF/microwave filters and related system applications and other specialists in RF/microwave engineering.
Supported by 202 equations and 170 illustrations, Airborne Early Warning System Concepts is an invaluable reference tool for a wide audience. It will be a welcome library addition for the engineer, scientist, system integrator, user, designer, or manager with interest in AEW concepts. It is also suitable for students and professors of electrical and system engineering or military science. This comprehensive discussion of airborne early warning (AEW) system concepts encompasses a wide range of issues, including capabilities and limitations, developmental trends and opportunities for improvement. Consisting of contributions from experts in the field, the book is presented at varying levels of complexity, ranging from elementary to advanced. For the generalist, the text provides a fundamental understanding of the status of AEW concepts with the use of only elementary mathematics. For the specialist, there are separate chapters that emphasize key AEW radar issues.
The continuing growth in the size and complexity of VLSI devices requires a parallel development of well-designed, efficient CAD tools. The majority of commercially available tools are based on an algorithmic approach to the problem and there is a continuing research effort aimed at improving these. The sheer complexity of the problem has, however, led to an interest in examining the applicability of expert systems and other knowledge based techniques to certain problems in the area and a number of results are becoming available. The aim of this book is to sample the present state-of-the-art in CAD for VLSI and it covers both newly developed algorithms and applications of techniques from the artificial intelligence community. The editors believe it will prove of interest to all engineers concerned with the design and testing of integrated circuits and systems.
This book presents the basic principles of transistor circuit analysis, basic per-stage building blocks, and feedback. The content is restricted to quasi-static (low-frequency) considerations, to emphasize basic topological principles. The reader will be able to analyze and design multi-stage amplifiers with feedback, including calculation and specification of gain, input and output resistances, including the effects of transistor output resistance. Of note is the presentation of feedback analysis, a subject rarely covered by other books, with insights and from angles that will reduce to analysis by inspection for readers. Some circuit transformations outlined within are especially helpful in reducing circuits to simpler forms for analysis. They are usefully applied in considering transistor circuits for which collector-emitter (or drain-source) resistance is not negligible, another often omitted topic which this book details.
This second volume, Analog Circuit Design: Designing Dynamic Circuit Response, builds upon the first volume (Analog Circuit Design: Designing Amplifier Circuits) by extending coverage to include reactances and their time- and frequency-related behavioral consequences. Retaining a design-oriented analysis, this volume begins with circuit fundamentals involving capacitance and inductance and lays down the approach using s-domain analysis. Additional concepts and perspectives fill in the blanks left by textbooks in regards to circuit design. It simplifies dynamic circuit analysis by using the graphical methods of reactance plots. Methods of compensating amplifiers, including feedback amplifiers, are kept as simple as possible using reactance plots and s-domain transfer functions that mainly require algebraic skill.
The third volume, Analog Circuit Design: Designing High-Performance Amplifiers, applies the concepts from the first two volumes. It is an advanced treatment of amplifier design/analysis emphasizing both wideband and precision amplification. Topics include bandwidth extension, noise and distortion, effects of components, instrumentation and isolation, amplifiers, autocalibration, thermal effects, current-feedback amplifiers, multi-path schemes, feed forward, fT multipliers, buffers, voltage translators, Giulbert gain cells and multipliers.
The fourth volume in the set, Analog Circuit Design: Designing Waveform-Processing Circuits, builds on the previous 3 volumes and presents a variety of analog non-amplifier circuits, including voltage references, current sources, filters, hysteresis switches and oscilloscope trigger and sweep circuitry, function generation, absolute-value circuits, and peak detectors. Digitizing (ADCs and DACs) and sampling (including some switched-capacitor) circuits are explained, with theory required for design. Sampling theory is developed from both a frequency and time-domain viewpoint, with emphasis upon application to design.
State-of-the-art analogue integrated circuit design is receiving a tremendous boost from the development and application of current-mode approaches, which are rapidly superseding traditional voltage-mode techniques. This activity is linked to important advances in integrated circuit technologies, such as the 'true' complementary bipolar process; CMOS VLSI technology, which allows realisation of high-performance mixed analogue and digital circuits; and gallium arsenide processing, which has matured to a point where it can be used effectively in high-speed analogue circuit and system design. In this book, all three technologies are represented, with key building blocks, circuit designs and applications. Many very important, but recent, techniques are presented, including switched-current techniques for high-precision filtering and A/D and D/A conversion, current-based amplifying techniques, and neural networks. Translinear principles, current mirrors, and the current conveyor are also covered. This book draws together contributions from the world's most eminent analogue IC designers to provide, for the first time, a comprehensive text devoted to this important and exciting new area of analogue electronics.
The inexorable increase in levels of integration of electronic circuits has most often been exploited using digital signals. So much so that design engineers have sought to digitise analogue signals as early as possible in the signal processing chain, and performed digital processing wherever practicable.
However it is increasingly being accepted that such an approach is not appropriate for many applications, and that circuits which combine analogue and digital signals can provide superior solutions. There are at least three factors which support this trend. Firstly improved process technology giving better dimensional and parametric control and the availability of BiCMOS and CMOS processes able to support both analogue and digital components. Secondly the maturing of discrete time circuit techniques giving competitive high performance solutions. Thirdly the gain in terms of reliability and reduction in cost achieved by mixing analogue and digital signal processing and hence implementing 'systems' on a single substrate.
It is therefore timely that wide ranging books such as this one, on the subject of mixed analogue digital ASICs should appear. It comprises eighteen chapters contributed by leading academics and practising engineers in industry. The chapters are arranged in four sections: Processing technology; Circuit Techniques and Building Blocks; Design and Applications; and CAD and Supporting Tools.
As electronics continue to become faster, smaller and more efficient, development and research around clocking signals and circuits has accelerated to keep pace. This book bridges the gap between the classical theory of clocking circuits and recent technological advances, making it a useful guide for newcomers to the field, and offering an opportunity for established researchers to broaden and update their knowledge of current trends.
The book begins by introducing the theory of Fourier transform and power spectral density, then builds on this foundation in chapter 2 to define phase noise and jitter. Chapter 3 discusses the theory and primary implementation of CMOS oscillators, including LC oscillators and ring oscillators, and chapter 4 introduces techniques for analysing their phase noise and jitter. Chapters 5-7 cover conventional clocking circuits; phase-locked loop (PLL) and delay-locked loop (DLL), which suppress the phase noise of CMOS oscillators. The building blocks of conventional PLLs/DLLs are described, and the dynamics of the PLL/DLL negative feedback loop explored in depth, with practical design examples. Chapters 8-11 address state-of-the-art circuit techniques for phase noise suppression, presenting the principles and practical issues in circuit implementation of sub-sampling phase detection techniques, all-digital PLL/DLL, injection-locked oscillator, and clock multiplying DLL. Extensive survey and discussion on state-of-the-art clocking circuits and benchmarks are covered in an Appendix.
Reset control is concerned with how to reset a system when it is disturbed to overcome the inherent limitations of linear feedback control and to improve robustness. It has found applications in many practical systems including flexible mechanical systems, tapespeed control systems and high precision positioning systems.
This book provides an introduction to the theory of reset control, and draws on the authors' own research and others' to explore the application of reset control in a variety of settings, with an emphasis on hard disk drive servo systems.
Topics covered include the motivation and basic concepts of reset control systems; derivation of the describing function of reset systems; how the reset matrix affects the frequency domain property of a system; recent developments on stability analysis of reset control systems; robust stability of reset control systems with uncertainties; reset control systems with discrete-time reset conditions; optimal reset control design under fixed reset time instants; and reset control systems with conic jump sets.
This book is essential reading for researchers, postgraduates and advanced students in control theory, and for research-based engineers who are interested in the theory of hybrid control systems and their engineering applications.
Most antennas are assembled from conducting surfaces and wires. The usual approach to numerical analysis of such structures is to approximate them by small surface or wire elements, with simple current approximation over the elements (the so-called subdomain approach), which requires a large amount of computer storage. This book describes a novel general entire-domain method for the analysis of metallic antennas and scatterers which enables the solution of a very wide class of problems to be obtained using computers of relatively modest capability.
Antenna-design engineers, scientists and graduate students interested in the analysis and design of electrically small and medium-sized metallic antennas and scatterers will find in this book a self-contained and extremely powerful tool that circumvents most difficulties encountered in other available methods.
Radar interferometers provide a cost-effective radar architecture to achieve enhanced angle accuracy for enhanced target tracking. The objective of this book is to quantify interferometer angle estimation accuracy by developing a general understanding of various radar interferometer architectures and presenting a comprehensive understanding of the effects of radar-based measurement errors on angle-of-arrival estimation. As such this book is primarily directed toward tracking radars but will also discuss imaging applications as well.
The objective of this book is to introduce students and interested researchers to antenna design and analysis using the popular commercial electromagnetic software FEKO. This book, being tutorial in nature, is primarily intended for students working in the field of antenna analysis and design; however the wealth of hands-on design examples presented in this book along with simulation details, makes it a valuable reference for practicing engineers. The requirement for the readers of this book is to be familiar with the basics of antenna theory; however electrical engineering students taking an introductory course in antenna engineering can also benefit from this book as a supplementary text.
The key strengths of this book are as follows: First, the basics of antenna simulation will be presented in a detailed, understandable, and easy to follow procedure through study of the simplest types of radiators, i.e. dipole and loop antennas, in chapters 2 and 3. This will build the fundamental knowledge a student would need in order to utilize antenna simulation software in general. Second, comparison between theoretical analysis and full-wave simulation results of FEKO are given for a variety of antenna types, which will aid the readers with a better understanding of the theory, approximations and limitations in the theoretical analysis, and solution accuracy. Third, and of paramount importance, is the visualization of the antenna current distribution, radiation patterns, and other radiation characteristics that are made available through full-wave simulations using FEKO. A proper analysis of the radiation characteristics through these visualizations serves as a powerful educational tool to fully understand the radiation behaviour of antennas
This is a professional level, introductory text on antenna principles, design, analysis, and measurements. It is especially suitable for persons who wish to improve their knowledge of antenna principles, concept design, performance analyses, and measurements. It is not a cookbook-like catalog for antenna design, nor does its understanding require a familiarity with electromagnetic theory, sophisticated mathematics, or complex computer techniques. The 3rd Edition updates and expands the original text by Lamont Blake, which was prepared at the undergraduate engineering, science, or technology level. For providing technical depth at the senior and graduate university levels, additions to the original book include a greatly expanded Chapter 7 on Antennas with Special Properties, a brand new Chapter 8 on Electronically Steered Arrays, and a revised Chapter 9 on Measurements. Also new to this edition are numerous appendices to the updated text.
Two powerful techniques for the analysis of aperture antennas are now used. One is based on the convenient Fourier transform relationship between aperture field and far-field radiation pattern. Here this relationship is derived from the plane wave spectrum representation of the aperture fields. In the near field of the aperture, Fourier transforms become Fresnel transforms. Far-field patterns may be predicted from near-field measurements by treating the near field as the aperture plane. In its application this method is basically the Kirchhoff approximation of diffraction theory. It is accurate for the forward fields of large antennas but cannot provide the lateral and back radiation.
The other method is based on aperture edge diffraction and called the geometrical theory of diffraction. It is developed from an asymptotic approximation to rigorous diffraction theory. Inherently more accurate and more widely applicable, it is especially useful in the calculation of antenna radiation in the lateral and rear directions. However, at present it fails in some situations where the Kirchhoff method succeeds, for example the axial fields of paraboloidal reflectors. In this sense the two methods are complementary and often both are required in antenna analysis. Application of the two methods to the calculation of the pattern, gain and reflection coefficient of some common antenna types is shown and comparisons are made with experiment.
Dimensional analysis is an engineering tool that is widely applied to numerous engineering problems, but has only recently been applied to control theory and problems such as identification and model reduction, robust control, adaptive control, and PID control.
Application of Dimensional Analysis in Systems Modeling and Control Design provides an introduction to the fundamentals of dimensional analysis for control engineers, and shows how they can exploit the benefits of the technique to theoretical and practical control problems. Topics covered include dimensional analysis and dimensional similarity, dynamical systems dimensionless representation, dimensionless systems identification and model order reduction, homogeneity of PID tuning rules, dimensionless PID tuning rules comparison, dimensional analysis control fundamentals, control of dimensionally similar systems, and adaptive control in the presence of input saturation.
This new book from Richard Klemm, author of the highly successful Principles of Space-time Adaptive Processing (IEE,2002), examines the various applications of space-time adaptive processing including applications in OTH-radar, ground target tracking, STAP in real world clutter environments, jammer cancellation, superresolution, active sonar, seismics and communications. Including contributions from distinguished international authors, the book provides a unique overview of the field of space-time procesing. The book is divided in two parts; the first dealing with the classical adaptive suppression of airbourne and space based radar clutter and the second comprising of miscellaneous applications in other fields such as communications, underwater sound and seismics.
The book will be of interest to those working in the field of sensor signal processing and in particular postgraduate students, research scientists, system engineers, university teachers and research project managers.
Applied Control Theory
J.R. Leigh The Institution of Engineering and Technology, 1987 Library of Congress TJ213.L334 1987 | Dewey Decimal 629.8
'To the surprise of some undergraduates, processes do not carry labels marking their variables nor, alas, are they conveniently classified into linear, nonlinear, stochastic, etc., categories. The ability to come to terms with this situation is a prerequisite for anyone proposing to succeed in an industrial environment.' This quotation from Chapter 1 characterises the viewpoint of the book, which is concerned with the application of control theory to real problems in their industrial context.
The book is structured around the following beliefs:
(a) Economic aspects must be considered at an early stage of any project.
(b) Simple techniques and ready-made manufacturer's solutions should be applied wherever possible.
(c) More advanced techniques will be received enthusiastically in those applications where they can offer a genuine contribution.
(d) Control systems using distributed microprocessor power will have an impact that is difficult to exaggerate. Control engineers must become familiar with the concepts involved.
(e) Familiarity with a wide range of applications is indispensable in developing an efficient approach in the field of applied control theory.
This second edition includes new material and supporting references on:
programmable logic controllers
distributed computer control systems
The book should be accessible to a wide variety of engineers. Preferably they should have an elementary knowledge of automatic control theory.
Non-metallic materials and composites are now commonplace in modern vehicle construction, and the need to compute scattering and other electromagnetic phenomena in the presence of material structures has led to the development of new simulation techniques.
This book describes a variety of methods for the approximate simulation of material surfaces, and provides the first comprehensive treatment of boundary conditions in electromagnetics. The genesis and properties of impedance, resistive sheet, conductive sheet, generalised (or higher order) and absorbing (or non-reflecting) boundary conditions are discussed. Applications to diffraction by numerous canonical geometries and impedance (coated) structures are presented, and accuracy and uniqueness issues are also addressed, high frequency techniques such as the physical and geometrical theories of diffraction are introduced, and more than i 30 figures illustrate the results, many of which have not appeared previously in the literature.
Written by two of the authorities m the field, this graduate-level text should be of interest to all scientists and engineers concerned with the analytical and numerical solution of electromagnetic problems.
There have been significant developments in the field of numerical methods for diffraction problems in recent years, and as a result, it is now possible to perform computations with more than ten million unknowns. However, the importance of asymptotic methods should not be overlooked. Not only do they provide considerable physical insight into diffraction mechanisms, and can therefore aid the design of electromagnetic devices such as radar targets and antennas, some objects are still too large in terms of wavelengths to fall in the realm of numerical methods. Furthermore, very low Radar Cross Section objects are often difficult to compute using multiple methods. Finally, objects that are very large in terms of wavelength, but with complicated details, are still a challenge both for asymptotic and numerical methods. The best, but now widely explored, solution for these problems is to combine various methods in so called hybrid methods.
Asymptotic and Hybrid Methods in Electromagnetics is based on a short course, and presents recent developments in the field.
Unlike conventional synchronous circuits, asynchronous circuits are not coordinated by a clocking signal, but instead use handshaking protocols to control circuit behaviour. Asynchronous circuits have been found to offer several advantages, including high energy efficiency, flexible timing requirements, high modularity, low noise/EMI, and robustness to PVT variations. At the same time, growing pressures on the electronics industry for ever smaller, more efficient ICs are pushing the limits of conventional circuit technologies. These factors are spurring growing interest in asynchronous circuits amongst both the academic research and commercial R&D communities.
This book introduces a wide range of existing and potential applications for asynchronous circuits, each accompanied with the corresponding circuit design theory, sample circuit implementations, results, and analysis. It serves as an essential guide for academic researchers and students looking to broaden their thinking in advancing asynchronous applications and design methodologies, and provides practical advice to industrial engineers when considering the incorporation of asynchronous circuits in their own applications.
The need to enhance the safety and efficiency of aviation systems has escalated with increasing aviation activity and competitiveness around the world. Weather, which is one of the principal factors affecting aviation performance, is acquiring ever more importance as aviation is poised to shift to futuristic paradigms such as free flight. Advanced systems and approaches to the surveillance of weather and the resultant generation of highly processed, detailed, accurate and reliable weather data, are becoming integral parts of support systems for navigation and air traffic management.
This accessible multidisciplinary book touches on all of the important scientific and technological aspects of the aviation weather surveillance problem. The emphasis is balanced between physical and system concepts, as well as description of state-of-the art and future devices and software.
Among the subjects covered are:
wind shear and atmospheric turbulence
surveillance system requirements
Doppler weather radar
polarimetric weather radars
radiometric satellite observation
automated surveillance systems
integrated aviation weather systems
Aviation weather surveillance systems should be of interest not only to personnel directly handling aviation meteorological functions, but also to pilots, air traffic controllers, airline managers, civil aviation system planners and regulators, accident investigators and indeed anyone with a serious interest in aviation.