bluuebunny/crossref_metadata_2025_split huggingface dataset:
The environment: a political view
Authors: Heseltine Michael 
Published: November 2023

Abstract
The Rt. Hon. Michael Heseltine, MP, was elected to Parliament as Conservative member in 1966 and has held a seat ever since. He took his degree in Philosophy, Politics, and Economics at Oxford and entered politics from a background in business and publishing. In 1970 he became Parliamentary Under-Secretary of State at the Department of the Environment and following the defeat of the Conservative Party in the general election of October 1974 held the positions of Opposition Spokesman on Industry (until 1976) and the Environment (1976-1979). When the Conservatives under Mrs Thatcher were returned to office in 1979, Michael Heseltine returned to the Department of the Environment as Secretary of State; in 1983 he was appointed Secretary of State for Defence.
The dilemma of the Amazon rain forests: biological reserve or exploitable resource?
Authors: Prance Ghillean T 
Published: November 2023

Abstract
Professor Ghillean (lain) Prance was appointed Director of the Royal Botanic Gardens, Kew in 1988, after spending 25 years in the United States. He is one of the world’s foremost experts on the Amazon rainforests. After graduation and the award of a doctorate at Oxford University, Iain Prance went to New York on what was intended to be a temporary appointment at the New York Botanical Gardens; in the event, he stayed on to become, in 1968, Curator of Amazonian Botany. He was subsequently appointed Director of Research at the New York Botanical Gardens and then Director of its Institute of Economic Botany. He held Visiting Professorships at the City University of New York and at Yale University. He was Leader of the United States Amazonian Exploration Program for 20 years and visited the region on numerous occasions. He is the author of several books on botany and Amazonia.
Changing diseases in changing environments
Authors: May Robert 
Published: November 2023

Abstract
Death from infectious disease was a much more commonplace thing in Victorian Britain than it is today. Most readers of this book will be able to cast their minds back several generations in their own family history to recall how the large families of Victorian times typically lost several children before adulthood. Likewise, children often lost parents-not least that symbol of the Victorian Age, Prince Albert-to infectious diseases. Such events run through the literature of that age: Beth in Little Women, the eponymous and obnoxiously saintly Little Lord Fauntleroy, the Lady of the Camellias.
Operational principles of brushless servomotors
Authors: Uchiyama Shunichi 
Published: November 2023

Abstract
A brushless servomotor has been developed by using interdisciplinary mechatronics engineering. A mechanical switching device (commutator) is replaced by electronic circuits and controllers, resulting in a maintenance-free and high-performance servo drive. This chapter also describes various other kinds of technologies used in servomotor drive development. The brushless servomotor is an a.c. motor in all respects and is in fact called the a.c. servomotor. Combined with a dedicated control device, the performance of the brushless servomotor is found to be equal to or superior to the performance of the high-performance d.c. servomotor.
Brushless servomotor control
Authors: Dote Yasuhiko 
Published: November 2023

Abstract
‘To control’ is defined as ‘to manipulate an object so as to serve a certain purpose (so as to make it work as desired).’ In our case, the motor is called the controlled system, the physical quantities (voltage, current, frequency, torque, angular velocity, and angle) are called the controlled variables, the required manipulations are called the manipulated variables (armature current, and frequency), and the instruction to be given is called the control reference.
Measurement and evaluation of brushless servomotors
Authors: Ishimine Hitoshi 
Published: November 2023

Abstract
Servomotors are used for automatic controllers, especially for servo-mechanisms. They control the stopping position and the rotational speed. Therefore, users demand that servomotors rotate evenly over a wide range of speed without being influenced by the load, and that they follow up the command signals and respond quickly. The topics explained in this chapter are measurement and evaluation of the items to be considered in satisfying the users’ demands.
Introduction
Authors: Vas Peter 
Published: November 2023

Abstract
It is the purpose of the present book to describe various alternating current (a.c.) and direct current (d.c.) electrical machines and variable-speed drives, including some of the most recently introduced modern drives, and also to present a general theory which is applicable during steady-state and transient operation. For this purpose a very detailed physical and mathematical analysis is presented which relies mainly on space-vector theory but the relationship to other theories, including the matrix theory of the generalized machine theory, has been emphasized throughout the book. The book can be used without any prior knowledge of space-vector theory or other theories. To make the book self-contained, the fundamental principles of the various alternating current electrical machines and drives are also discussed; thus it can be used for complete and self-contained courses at different levels. Furthermore it can be used by researchers and other academics and members of the industry, and it has been one of the main intentions to develop the theory and equations in a user-oriented form. Thus, in many parts, the equations are given in their final (state-variable or analytical) forms, which can be directly used for computer simulations or for hand calculations. These also include the small-signal equations, which enable stability analysis to be performed.
Core Losses
Authors: Miller TJE , Rabinovici R 
Published: November 2023

Abstract
After copper losses, core losses are generally the second largest component of power loss or inefficiency in the brushless motor, although their significance may become overriding at very high speeds. They arise from the variation of magnetic flux-density throughout the core, particularly the stator core. This variation incurs hysteresis and eddy-current losses, (Chapter 16). Briefly summarizing, the hysteresis loss results from the “unwillingness” of the steel to change its magnetic state, and as the flux-density varies cyclically the magnetic state describes a locus in the B/H diagram: the energy loss per cyde is proportional to the enclosed area, so the average power loss due to hysteresis is proportional to the frequency of the variation in the magnetic field. Eddy-current loss is also caused by variations in flux-density, which induce current to flow in the stator steel at the same frequency as the variation in the magnetic field. The EMF which drives these currents is proportional to the peak magnetic field and to the frequency of variation, but the power loss is proportional to the square of the EMF and therefore also varies with the square of the peak flux-density and the frequency. Eddy-current losses can be reduced by using thinner lamination steels.
Cooling
Authors: Miller TJE 
Published: November 2023

Abstract
Heat transfer is as important as electromagnetic and mechanical design. The analysis of heat transfer and fluid flow in motors is actually more complex, more nonlinear, and more difficult than the electromagnetic behaviour. It is often dealt with by means of simplified equivalent circuits, and rarely receives the detailed analysis lavished on electromagnetic aspects. Perhaps there is some justification for using approximate methods for heat transfer, when exact methods are pursued for electromagnetic design. The electromagnetic design determines the geometry of laminations which are cut to fine tolerances. Their geometry and thickness, together with their material properties and the design of the windings, determine whether or not the motor will deliver the required torque. They also determine the precise voltages and currents that will be experienced by the power semiconductors in the controller.
Introduction
Authors: Vas Peter 
Published: November 2023

Abstract
In the present book, artificial-intelligence-based electrical machines and variable-speed drives are discussed. For this purpose, various static and adaptive fuzzy logic systems, unsupervised and supervised artificial neural networks, fuzzy-neural networks, and genetic-algorithm-assisted systems are considered. Artificial intelligence (AI) is used for various purposes, including simulation (in the steady state and transient state), identification, estimation, control, design, condition monitoring, and diagnosis. Great emphasis is laid on presenting detailed description of the various techniques. For this purpose and also to make the book self-contained, the fundamentals of the different AI-based techniques, which are also referred to as soft-computing techniques in the literature, are also discussed in detail and many worked-out examples are given. The book contains the most up-to-date and modern developments in the field.
Fuzzy-neural systems
Authors: Vas Peter 
Published: November 2023

Abstract
In Section 4.5 the main features of adaptive fuzzy-neural systems were discussed. It follows that a fuzzy-neural network has a structure resulting from the combination of a fuzzy system and a neural network. It is the goal of this network to perform a required non-linear mapping from input to output spaces by using a neural network integrated with a fuzzy system (fuzzy-neural network) whose parameters are adjusted to improve performance by using a learning algorithm. Usually the design methods are hybrid design methods, originating from both fuzzy system and neural system concepts. Some of the main features are: Main aspects of neural-fuzzy system integration: the most useful features of the two system should be combined; combination should be performed in such a way that resulting integrated system should be most efficient.
Artificial-intelligence-based steady-state and transient analysis of d.c. machines, estimators, control
Authors: Vas Peter 
Published: November 2023

Abstract
In the present chapter, first, the Al-based steady-state and transient analysis of d.c. machines is discussed. For this purpose ANNs and fuzzy-neural networks are used. This is followed by describing AI-based drives, e.g. d.c. drives with ANN speed estimators, d.c. drives with fuzzy controllers, d.c. drives with fuzzy-neural estimators, d.c. drives with neuro controllers (including combined controllers, e.g. where instead of using a separate speed and current controller, a single, ANN-based combined controller is used).Traditionally mathematical model-based analysis techniques have always been used for the steady-state and transient analysis of electrical machines and drives. There are many techniques, but they mainly differ in their complexity and the many assumptions used. In general, when generalized machine theory is used for transient analysis of a d.c. machine, the stator and rotor differential equations, together with the equation of motion, are used for simulation purposes. In a d.c. drive these equations are complemented by the equations governing the controllers and the converter. Thus, in general, a system of first-order non-linear differential equations is obtained, which can be solved by using a numerical technique (e.g. Runge-Kutta technique). However, it is also possible to perform the simulations by using neural networks, or fuzzy-neural networks, which do not require a mathematical model [Vas, 1998]. Such a system is not restricted by the many assumptions used in conventional electrical machine theories.
The organization of the book
Authors: d’Invemo Ray 
Published: November 2023

Abstract
There is little doubt that relativity theory captures the imagination. Nor is it surprising: the anti-intuitive properties of special relativity, the bizarre characteristics of black holes, the exciting prospect of gravitational wave detection and with it the advent of gravitational wave astronomy, and the sheer scope and nature of cosmology and its posing of ultimate questions; these and other issues combine to excite the minds of the inquisitive. Yet, if we are to look at these issues meaningfully, then we really require both physical insight and a sound mathematical foundation. The aim of this book is to help provide these. The book grew out of some notes I wrote in the mid-1970s to accompany a UK course on general relativity. Originally, the course was a third-year undergraduate option aimed at mathematicians and physicists. It subsequently grew to include M.Sc. students and some first-year Ph.D. students. Consequently, the notes, and with it the book, are pitched principally at the undergraduate level, but they contain sufficient depth and coverage to interest many students at the first-year graduate level. To help fulfil this dual purpose, I have indicated the more advanced sections (level-two material) by a grey shaded bar alongside the appropriate section. Level-one material is essential to the understanding of the book, whereas level two is enrichment material included for the more advanced student. To help put a bit more light and shade into the book, the more important equations and results are given in tint panels.
The K-calculus
Authors: d’Invemo Ray 
Published: November 2023

Abstract
Before we start, we should be clear what we are about. The essential activity of mathematical physics, or theoretical physics, is that of modelling or model building. The activity consists of constructing a mathematical model which we hope in some way captures the essentials of the phenomena we are investigating. I think we should never fail to be surprised that this turns out to be such a productive activity. After all, the first thing you notice about the world we inhabit is that it is an extremely complex place. The fact that so much of this rich structure can be captured by what are, in essence, a set of simple formulae is to me quite astonishing. Just think how simple Newton’s universal law of gravitation is; and yet it encompasses a whole spectrum of phenomena from a falling apple to the shape of a globular cluster of stars. As Einstein said, ‘The most incomprehensible thing about the world is that it is comprehensible.’
The energy-momentum tensor
Authors: d’Invemo Ray 
Published: November 2023

Abstract
Our programmer for this chapter is to look at the three most important energy—momentum tensors in general relativity, namely, the energy—momentum tensors for incoherent matter or dust, a perfect fluid, and the electromagnetic field. In passing, we shall encounter a tensor formulation of Maxwell’s equations governing the electromagnetic field. Again, our treatment will not be exhaustive or complete, but will be sufficient for generating the explicit expressions for the three tensors, and these expressions will be essentially all that we require in future chapters. We shall also look more carefully at the Newtonian limit and discuss the calculation for determining the coupling constant.
The structure of the field equations
Authors: d’Invemo Ray 
Published: November 2023

Abstract
1. The field equations are differential equations for determining the metric tensor gabfrom a given energy-momentum tensor Tab.Here, we are reading the equations from right to left. This is a Machian way of viewing the equations since one specifies a matter distribution and then solves the equations to ascertain the resulting geometry. It is also a natural way of looking at the Einstein-Maxwell equations, namely, what geometry corresponds to a given Maxwell tensor? The most important case of the equations is when Tab= 0, in which case we are concerned with finding vacuum solutions.
Experimental tests of general relativity
Authors: d’Invemo Ray 
Published: November 2023

Abstract
In this chapter, we shall consider the experimental status of general relativity. We shall see that the status is very different from that of special relativity, which has been subjected to a welter of different tests. Indeed, there are very few theories whose experimental footing has been so well established. In contrast, there are very few tests of the general theory. The main reason for this small number is that the gravitational fields experienced in our locality are very weak and their effects are not significantly different from the corresponding Newtonian ones. The extent to which the tests we have are actually tests of the particular set of field equations of general relativity as opposed to much weaker statements like the principle of equivalence is also arguable. The first tests of the theory were the three so-called ‘classical tests’ of general relativity, namely, the precession of the perihelion of Mercury, the bending of light, and the gravitational red shift. These tests have been augmented more recently by a fourth classical test, the delay of a light signal in a gravitational field.
Charged black holes
Authors: d’Invemo Ray 
Published: November 2023

Abstract
the Reissner-Nordstrom solution for a charged mass point. The importance of this solution is that its structure is in many ways similar to that of the more complicated Kerr solution describing rotating black holes which we shall meet in the next chapter. The approach we adopt is to look for a static, asymptotically flat, spherically symmetric solution of the Einstein-Maxwell field equations.
Rotating black holes
Authors: d’Invemo Ray 
Published: November 2023

Abstract
In this chapter, we shall investigate the Kerr solution which describes rotating black holes. It turns out to be a rather long process to solve Einstein’s vacuum equations directly for the Kerr solution. We shall, instead, describe a ‘trick’ of Newman and Janis for obtaining the Kerr solution from the Schwarzschild solution. This same trick can then be applied to the Reissner-Nordstrnm solution to obtain the Kerr-Newman solution, the most general solution for a charged rotating black hole. In order to discuss this approach, we start by introducing the very important idea of a null tetrad.
Plane gravitational waves
Authors: d’Invemo Ray 
Published: November 2023

Abstract
Our consideration of gravitational radiation or gravitational waves (gravity waves for short) starts from the pioneering work of Einstein and is based on the linearized form of the field equations. In this approximation, we shall see that plane wave solutions lead to the result that gravitational waves are transverse and possess two polarization states. Put another way, the gravitational field has two radiation degrees of freedom. In the linearized approximation of the field equations, general relativity is recast as a Lorentz-covariant theory. Considerable caution has to be exercised in doing this because there are associated with it a number of serious difficulties and limitations (the details of which are beyond the brief of this book), but nonetheless it does throw some important light on the general theory.
Radiation from an isolated source
Authors: d’Invemo Ray 
Published: November 2023

Abstract
The extent to which the results of the linearized theory can be trusted is not clear. The non-linearity of the gravitational field is one of its most characteristic properties, and it is likely that at least some of the crucial properties of the field should show themselves through the non-linear terms. Indeed, we have met exact solutions of the Einstein vacuum field equations corresponding to plane gravitational waves and we have seen that superposition of them leads to the creation of intrinsic singularities. This result is certainly absent in the linear case, so clearly there are differences. However, even these solutions are global vacuum solutions abstracted away from sources and as such are physically unrealistic, even if they may give us important information about how waves behave in asymptotic regions. What we would really like to do is to be able to investigate gravitational waves from bounded isolated sources, since then we would be in a position to discuss energy transfer and it is this which determines whether or not gravitational waves behave in the same way as other forms of radiation. Such a model system consists of an isolated bounded source (preferably possessing as much symmetry as possible, so that the field equations are easier to handle) which has been quiescent for a semi-infinite period, then radiates for a finite time, and afterwards becomes quiescent again. If the resulting waves are real physical waves, in that they carry energy, then we might expect the source to lose mass (and possibly other multipole moments may change) in the process.
Polynomials, stability, and matrix equations
Authors: Barnett Stephen 
Published: November 2023

Abstract
In Problem 4.8 it was seen how when the Laplace transform is applied to a set of constant-coefficient linear differential equations then the solution involves the characteristic polynomial of the system matrix. Readers familiar with the Laplace transform will be aware that any nth order linear differential equation can be transformed into a problem involving an nth degree polynomial; the same applies to linear difference equations when the z-transform is used (Ogata, 1987). In this chapter we show how properties of polynomials can be investigated using matrix techniques. In particular, it will be seen that the gaussian elimination procedure once again proves useful.
Polynomial and rational matrices
Authors: Barnett Stephen 
Published: November 2023

Abstract
11.15 which describe a certain simple dynamical model. Suppose that the initial conditions for 01, 81, 02, 82 are all zero. Applying the Laplace transform to these equations then produces The 2 x 2 matrix A(s) on the left in (12.2) is an example of a polynomial matrix, whose elements are themselves polynomials. As for a scalar polynomial, A(s) can be written in terms of powers of s:
Optimal control problems
Authors: Hocking Leslie M 
Published: November 2023

Abstract
All vehicles require controls if they are to function in a desired manner. These controls may, for example, steer the vehicle, accelerate it, or stop it. We can therefore think of the vehicle in two parts: the engine, body, and seats, and the controls: accelerator, brake and steering wheel. The controls may be activated by a driver in the vehicle or remotely by radio signals from outside. It is also possible for the controls to be worked automatically by a feedback device. There are two ways in which controls may be needed by a moving system. They are needed to move the system from an original state to a desired one, but they may also be needed for continuous operation in order to counter deviations from a desired path. For example, a ship may be set on a straight course, but without constant applications of touches on the rudder it will tend to wander from the desired bearing. This is because the system is unstable and unavoidable minute disturbances will produce a large drift from the correct course unless controls are applied.
The basic Pontryagin maximum principle
Authors: Hocking Leslie M 
Published: November 2023

Abstract
In this chapter we state the Pontryagin maximum principle (PMP) in its simplest form and use it to solve some simple examples. Extensions to a less restricted class of problems are discussed in Chapter 7, but the proof of the PMP is postponed to Chapter 9. Before giving the complete statement of the PMP, and in order to see clearly how the principle is applied, we look first at a very simple problem in detail and go through the steps required in using the PMP to obtain a solution. A system in unstable equilibrium is one in which any deviation from equilibrium increases if the system is left to itself. The application of a control aims to reduce the deviation to zero, but at some cost depending on the size of the control that has to be employed. Suppose the state of the system is given by a single state variable x1, with x1 = 0 in equilibrium.