Bøger udgivet af Springer London

Sloshing causes liquid to fluctuate, making accurate level readings difficult to obtain in dynamic environments. The measurement system described uses a single-tube capacitive sensor to obtain an instantaneous level reading of the fluid surface, thereby accurately determining the fluid quantity in the presence of slosh. A neural network based classification technique has been applied to predict the actual quantity of the fluid contained in a tank under sloshing conditions.  In A neural network approach to fluid quantity measurement in dynamic environments, effects of temperature variations and contamination on the capacitive sensor are discussed, and the authors propose that these effects can also be eliminated with the proposed neural network based classification system. To examine the performance of the classification system, many field trials were carried out on a running vehicle at various tank volume levels that range from 5 L to 50 L. The effectiveness of signal enhancement on the neural network based signal classification system is also investigated. Results obtained from the investigation are compared with traditionally used statistical averaging methods, and proves that the neural network based measurement system can produce highly accurate fluid quantity measurements in a dynamic environment. Although in this case a capacitive sensor was used to demonstrate measurement system this methodology is valid for all types of electronic sensors. The approach demonstrated in A neural network approach to fluid quantity measurement in dynamic environments can be applied to a wide range of fluid quantity measurement applications in the automotive, naval and aviation industries to produce accurate fluid level readings. Students, lecturers, and experts will find the description of current research about accurate fluid level measurementin dynamic environments using neural network approach useful.

Modern power electronic converters are involved in a very broad spectrum of applications: switched-mode power supplies, electrical-machine-motion-control, active power filters, distributed power generation, flexible AC transmission systems, renewable energy conversion systems and vehicular technology, among them.Power Electronics Converters Modeling and Control teaches the reader how to analyze and model the behavior of converters and so to improve their design and control. Dealing with a set of confirmed algorithms specifically developed for use with power converters, this text is in two parts: models and control methods. The first is a detailed exposition of the most usual power converter models:* switched and averaged models;* small/large-signal models; and* time/frequency models.The second focuses on three groups of control methods:* linear control approaches normally associated with power converters;* resonant controllers because of their significance in grid-connected applications; and* nonlinear control methods including feedback linearization, stabilizing, passivity-based, and variable-structure control.Extensive case-study illustration and end-of-chapter exercises reinforce the study material.Power Electronics Converters Modeling and Control addresses the needs of graduate students interested in power electronics, providing a balanced understanding of theoretical ideas coupled with pragmatic tools based on control engineering practice in the field. Academics teaching power electronics will find this an attractive course text and the practical points make the book useful for self tuition by engineers and other practitioners wishing to bring their knowledge up to date.

Model Predictive Control is an important technique used in the process control industries. It has developed considerably in the last few years, because it is the most general way of posing the process control problem in the time domain. The Model Predictive Control formulation integrates optimal control, stochastic control, control of processes with dead time, multivariable control and future references. The finite control horizon makes it possible to handle constraints and non linear processes in general which are frequently found in industry. Focusing on implementation issues for Model Predictive Controllers in industry, it fills the gap between the empirical way practitioners use control algorithms and the sometimes abstractly formulated techniques developed by researchers. The text is firmly based on material from lectures given to senior undergraduate and graduate students and articles written by the authors.

This updated translation from the original German edition provides general background information on oceanology and ocean engineering is given, along with descriptions of drilling techniques, offshore structures and hydrocarbon production at sea. The main part of the book is concerned with the hydrostatic and hydrodynamic analysis of marine structures, followed by an evaluation of marine structure reliability. Environmental conditions affecting marine structures, wave statistics, and the application of reliability theory to code development are also discussed. Students and practising engineers who have an interest in the analysis of marine structures will find this book an invaluable reference.

Although most textbooks of neurology contain a certain amount of pathological informa- tion, neuropathology has often been treated in isolation. However, neuropathology has a close relationship to clinical neurology, neurosurgery and neuroradiology. Thus, advances in the rapidity and accuracy of pathological diagnosis have often led to changes in clinical management and, recently, improvements in clinical diagnosis, particularly CT scanning, have brought about a change in emphasis in the practice of neuropathology. In this textbook we have sought to present a widely based account of neuropathology in combination with information from clinical experience. We chose this approach in order to emphasize the close interrelation between clinician and pathologist. The book grew out of a course organised jointly by two neurologists and two neuropathologists from the Depart- ments of Neuropathology and Neurology of The London Hospital and The University of Southampton. It is hoped that the book will be useful not only to pathologists, neurologists, neurosurgeons, and neuroradiologists, but also to general physicians. In a period of rapid advance in knowledge it is important to recognise how changes in the clinical and laboratory disciplines overlap. In order to make the most of consultations with pathologist colleagues the clinician must know what skills and techniques are available in the laboratory, and similarly, the pathologist must keep abreast of changes in clinical practice. In the past the clinician and pathologist have often been slow to appreciate advances in each other's fields.

Many problems in operator theory lead to the consideration ofoperator equa- tions, either directly or via some reformulation. More often than not, how- ever, the underlying space is too 'small' to contain solutions of these equa- tions and thus it has to be 'enlarged' in some way. The Berberian-Quigley enlargement of a Banach space, which allows one to convert approximate into genuine eigenvectors, serves as a classical example. In the theory of operator algebras, a C*-algebra A that turns out to be small in this sense tradition- ally is enlarged to its (universal) enveloping von Neumann algebra A"e;. This works well since von Neumann algebras are in many respects richer and, from the Banach space point of view, A"e; is nothing other than the second dual space of A. Among the numerous fruitful applications of this principle is the well-known Kadison-Sakai theorem ensuring that every derivation 8 on a C*-algebra A becomes inner in A"e;, though 8 may not be inner in A. The transition from A to A"e; however is not an algebraic one (and cannot be since it is well known that the property of being a von Neumann algebra cannot be described purely algebraically). Hence, ifthe C*-algebra A is small in an algebraic sense, say simple, it may be inappropriate to move on to A"e;. In such a situation, A is typically enlarged by its multiplier algebra M(A).

New surgical techniques for the treatment of anal incontinence have given the increasing number of afflicted patients hope for a cure. Colorectal surgeons and more and more general surgeons are performing operations, yet until now they have not had a text that they can use as a reference work. The guidance and instruction that surgeons need are now available in this atlas. It describes every operation in technical detail, and the two-color illustrations clearly show the essential points of each procedure. The authors discuss thoroughly the indications for surgical treatment, its application to the individual patient, and post-operative care. The comprehensive scope of this book makes it a rich source of information for surgeons working outside highly specialized centers. For specialists, it is the only practical reference available on the subject.

James Stirling's "e;Methodus Differentialis"e; is one of the early classics of numerical analysis. It contains not only the results and ideas for which Stirling is chiefly remembered, for example, Stirling numbers and Stirling's asymptotic formula for factorials, but also a wealth of material on transformations of series and limiting processes. An impressive collection of examples illustrates the efficacy of Stirling's methods by means of numerical calculations, and some germs of later ideas, notably the Gamma function and asymptotic series, are also to be found. This volume presents a new translation of Stirling's text that features an extensive series of notes in which Stirling's results and calculations are analysed and historical background is provided. Ian Tweddle places the text in its contemporary context, but also relates the material to the interests of practising mathematicians today. Clear and accessible, this book will be of interest to mathematical historians, researchers and numerical analysts.

The series Advances in Industrial Control aims to report and encourage technology transfer in control engineering. The rapid development of control technology has an impact on all areas of the control discipline. New theory, new controllers, actuators, sensors, new industrial processes, computer methods, new applications, new philosophies . . . , new challenges. Much of this development work resides in industrial reports, feasibility study papers and the reports of advanced collaborative projects. The series otTers an opportunity for researchers to present an extended exposition of such new work in all aspects of industrial control for wider and rapid dissemination. The time for nonlinear control to enter routine application seems to be approaching. Nonlinear control has had a long gestation period but much ofthe past has been concerned with methods that involve formal nonlinear functional model representations. It seems more likely that the breakthough will come through the use of other more flexible and amenable nonlinear system modelling tools. This Advances in Industrial Control monograph by Guoping Liu gives an excellent introduction to the type of new nonlinear system modelling methods currently being developed and used. Neural networks appear prominent in these new modelling directions. The monograph presents a systematic development of this exciting subject. It opens with a useful tutorial introductory chapter on the various tools to be used. In subsequent chapters Doctor Liu leads the reader through identification, and then onto nonlinear control using nonlinear system neural network representations.

In the 1970's, James developped a ``characterictic-free'' approach to the representation theory of the symmetric group on n letters, where Specht modules and certain bilinear forms on them play a crucial role. In this framework, we obtain a natural parametrization of the irreducible representations, but it is a major open problem to find explicit formulae for their dimensions when the ground field has positive characteristic.In a wider context, this problem is a special case of the problem of determining the irreducible representations of Iwahori--Hecke algebras at roots of unity. These algebras arise naturally in the representation theory of finite groups of Lie type, but they can be defined abstractly, as certain deformations of group algebras of finite Coxeter groups where the deformation depends on one or several parameters. One of the main aims of this book is to classify the irreducible representations of these Iwahori-Hecke algebras algebras at roots of unity. For this purpose, we develop an analogue of James' ``characterictic-free'' approach to the representation theory of Iwahori-Hecke algebras in general. The framework is provided by the Kazhdan-Lusztig theory of cells and the Graham-Lehrer theory of cellular algebras. When working over a ground field of characteristic zero, we also determine the dimensions of the irreducible representations, either by purely combinatorial algorithms (for algebras of classical type) or by explicit computations and tables (for algebras of exceptional type). The methods rely in an essential way on the ideas and results originating with the Lascoux-Leclerc-Thibon conjecture, which links Iwahori-Hecke algebras at roots of unity with the theory of canonical and crystal bases for the Fock space representations of certain affine Lie algebras. Thus, the main results of this book are obtained by an interaction of several branches of mathematics: Fock spaces and affine Lie algebras, the combinatorics of crystal bases, the theory of Kazhdan-Lusztig bases and cells, and computational methods.

This work presents a data visualization technique that combines graph-based topology representation and dimensionality reduction methods to visualize the intrinsic data structure in a low-dimensional vector space. The application of graphs in clustering and visualization has several advantages. A graph of important edges (where edges characterize relations and weights represent similarities or distances) provides a compact representation of the entire complex data set. This text describes clustering and visualization methods that are able to utilize information hidden in these graphs, based on the synergistic combination of clustering, graph-theory, neural networks, data visualization, dimensionality reduction, fuzzy methods, and topology learning. The work contains numerous examples to aid in the understanding and implementation of the proposed algorithms, supported by a MATLAB toolbox available at an associated website.

Fuel cells are widely regarded as the future of the power and transportation industries. Intensive research in this area now requires new methods of fuel cell operation modeling and cell design. Typical mathematical models are based on the physical process description of fuel cells and require a detailed knowledge of the microscopic properties that govern both chemical and electrochemical reactions. Advanced Methods of Solid Oxide Fuel Cell Modeling proposes the alternative methodology of generalized artificial neural networks (ANN) solid oxide fuel cell (SOFC) modeling. Advanced Methods of Solid Oxide Fuel Cell Modeling provides a comprehensive description of modern fuel cell theory and a guide to the mathematical modeling of SOFCs, with particular emphasis on the use of ANNs. Up to now, most of the equations involved in SOFC models have required the addition of numerous factors that are difficult to determine. The artificial neural network (ANN) can be applied to simulate an object's behavior without an algorithmic solution, merely by utilizing available experimental data. The ANN methodology discussed in Advanced Methods of Solid Oxide Fuel Cell Modeling can be used by both researchers and professionals to optimize SOFC design. Readers will have access to detailed material on universal fuel cell modeling and design process optimization, and will also be able to discover comprehensive information on fuel cells and artificial intelligence theory.

Long regarded as the finest photographic lunar atlas available, The Hatfield Lunar Atlas is a model of accuracy and clarity. This new version updates some of the maps, names and technical data, but uses Commander Henry Hatfield's original - and unexcelled - photographic plates, taken with a purpose-built 30 cm reflector. The Atlas is divided into sixteen sections, each of which is made up of five or more photographic plates together with a map. Each map is based primarily of the facing plate. Where detail is lacking on this primary plate (particularly near the Moon's limb) supplementary detail is provided by one or more of the other plates in a particular section.

The main aim of this book is to develop the methods of Global Analysis and of Stochastic Analysis such that their combination allows one to have a more or less common treatment for areas of mathematical physics that traditionally are considered as quite distant from each other and requiring different methods of investigation. Among those areas we mention classical mechanics on non-linear configuration spaces, some problems of statistical and quantum physics, hydrodynamics, etc. The idea, yielding the unification of these topics, is based on the use of a geometrically invariant form of Newton's second law and its analogs (stochastic, set-valued, infinite-dimensional, etc.) as a fundamental equation of motion.

The Virasoro algebra is an infinite dimensional Lie algebra that plays an increasingly important role in mathematics and theoretical physics. This book describes some fundamental facts about the representation theory of the Virasoro algebra in a self-contained manner. Topics include the structure of Verma modules and Fock modules, the classification of (unitarizable) Harish-Chandra modules, tilting equivalence, and the rational vertex operator algebras associated to the so-called minimal series representations.Covering a wide range of material, this book has three appendices which provide background information required for some of the chapters. The authors organize fundamental results in a unified way and refine existing proofs. For instance in chapter three, a generalization of Jantzen filtration is reformulated in an algebraic manner, and geometric interpretation is provided. Statements, widely believed to be true, are collated, and results which are known but not verified are proven, such as the corrected structure theorem of Fock modules in chapter eight.This book will be of interest to a wide range of mathematicians and physicists from the level of graduate students to researchers.

- Following on from the 2000 edition of Jan De Witt's Elementa Curvarum Linearum, Liber Primus, this book provides the accompanying translation of the second volume of Elementa Curvarum Linearum (Foundations of Curved Lines). One of the first books to be published on Analytic Geometry, it was originally written in Latin by the Dutch statesman and mathematician Jan de Witt, soon after Descartes' invention of the subject. - Born in 1625, Jan de Witt served with distinction as Grand Pensionary of Holland for much of his adult life. In mathematics, he is best known for his work in actuarial mathematics as well as extensive contributions to analytic geometry.- Elementa Curvarum Linearum, Liber Secondus moves forward from the construction of the familiar conic sections covered in the Liber Primus, with a discussion of problems connected with their classification; given an equation, it covers how one can recover the standard form, and additionally how one can find the equation's geometric properties. - This volume, begun by Albert Grootendorst (1924-2004) and completed after his death by Jan Aarts, Reinie Ern and Miente Bakker, is supplemented by:- annotation explaining finer points of the translation;- extensive commentary on the mathematicsThese features make the work of Jan de Witt broadly accessible to today's mathematicians.

Deligne-Lusztig theory aims to study representations of finite reductive groups by means of geometric methods, and particularly l-adic cohomology. Many excellent texts present, with different goals and perspectives, this theory in the general setting. This book focuses on the smallest non-trivial example, namely the group SL2(Fq), which not only provides the simplicity required for a complete description of the theory, but also the richness needed for illustrating the most delicate aspects.The development of Deligne-Lusztig theory was inspired by Drinfeld's example in 1974, and Representations of SL2(Fq) is based upon this example, and extends it to modular representation theory. To this end, the author makes use of fundamental results of l-adic cohomology. In order to efficiently use this machinery, a precise study of the geometric properties of the action of SL2(Fq) on the Drinfeld curve is conducted, with particular attention to the construction of quotients by various finite groups.At the end of the text, a succinct overview (without proof) of Deligne-Lusztig theory is given, as well as links to examples demonstrated in the text. With the provision of both a gentle introduction and several recent materials (for instance, Rouquier's theorem on derived equivalences of geometric nature), this book will be of use to graduate and postgraduate students, as well as researchers and lecturers with an interest in Deligne-Lusztig theory.