bluuebunny/crossref_metadata_2025_split huggingface dataset:
Computational Projective Geometry, 2
Authors: Kanatani Kenichi 
Published: November 2023

Abstract
Projective geometry in the form described in Chapter 2 does not involve any metrics (e.g., lengths and angles). It certainly suits the description of “parallelism” in 3-D scenes in terms of vanishing points and vanishing lines. However, “orthogonality” is also an important characteristic of 3-D scenes, since many man-made objects have rectangular shapes and orthogonal edges. In this chapter, we show that orthogonality in 3-D scenes can be described in terms of projective geometry if we introduce a special “conic” called the absolute conic. It is shown that the camera rotation transformation introduced in Section 2.3.1 is characterized as a collineation that preserves the absolute conic. It is also shown that the conjugacy with respect to the absolute conic can be interpreted as orthogonality in 3-D scenes. We then discuss two machine vision applications: camera calibration and 3-D road shape reconstruction, the latter being an important component of autonomously navigating land vehicles.
Torque control of switched reluctance motors
Authors: Vas Peter 
Published: November 2023

Abstract
In the present chapter, first the fundamentals of switched reluctance motor drives are discussed. This is then followed by a description of various position estimators which can be used in position-sensor less switched reluctance motor drives. Finally the two main possibilities for instantaneous torque-controlled switched reluctance motor drives are discussed. The first solution uses profiled stator currents, and thus the drive contains a current controller, but the second solution uses profiled stator flux linkages, and the drive scheme contains a stator flux-linkage controller. It is shown that the second scheme is simpler to implement. Both schemes can operate in a wide speed range and offer the potential of using switched reluctance motors in many applications, where so far only other types of motors have been used.
Introduction
Authors: Dote Yasuhiko , Hoft Richard G 
Published: November 2023

Abstract
In the field of computer integrated manufacturing (CIM), equipment such as computer numerically controlled (CNC) machine tools, industrial robots, etc., is being widely used to save energy, to implement automation, and to increase both production and the quality of products. This equipment which is used in common societal and industrial applications such as energy, environment, food, housing, and transportation, etc., is becoming more sophisticated day by day with the application of intelligent control techniques. Self-controlled AC drives and UPS systems which are typical products of power electronic systems are being employed as supporting tools to fulfill the above requirements.
Inverters
Authors: Dote Yasuhiko , Hoft Richard G 
Published: November 2023

Abstract
The semiconductor age began with the announcement by Bell Laboratories of the invention of the transistor in 1948 (the year that the second author earned his BSEE degree from Iowa State University in the USA). Bardeen, Brattain, and Shockley received the Nobel Prize for this most significant discovery. Silicon diodes soon became available to replace selenium and germanium diodes. General Electric in the USA introduced the silicon controlled rectifier (SCR) in 1957 and this gave great impetus to the development of semiconductor inverter and converter circuits. Reference [l] published in 1964 was the first modern book on inverters. Reference [2] is believed to be the first textbook written for use in senior and graduate level courses on power electronics, and [3] is a slightly updated version of [2]. Thyristor inverters are used widely in large motor drives, high-voltage DC systems, and in large battery storage systems to supply peak loads on utility systems.
Robust AC drive control
Authors: Dote Yasuhiko , Hoft Richard G 
Published: November 2023

Abstract
This chapter describes a simple gain scheduling robust controller whose parameters are continuously changed by fuzzy logic such that the controller makes the system respond quickly if the error e is large (SIN is large) and vice versa in order to obtain a robust controller which is insensitive to both plant noise and observation noise. Then, the controller is applied to speed control of an induction drive without a tachometer (sensor). Experiments show that the proposed controller is superior to both a sliding mode controller and a PID controller. This chapter also includes the stability analysis of the overall system.
The Materials Equations
Authors: Solymar L , Webb D J , Grunnet-Jepsen A 
Published: November 2023

Abstract
We have already discussed a simple model of charge transport in Section 1.3 and two somewhat more complicated models in Section 2.11 where we considered both electrons and holes. Our aim is now to present further models which were used at some time or other in the literature. The complications that come are quantitative rather than qualitative. One may have more species of impurities (or traps as they are often called) and more transitions between them, but each process can still be understood by a modest amount of solid state theory.
Multi-Wave Mixing
Authors: Solymar L , Webb D J , Grunnet-Jepsen A 
Published: November 2023

Abstract
In the preceding chapters we have seen that the interaction of two beams within a photorefractive medium involves a great deal of interesting physics and can result in optical amplification. As might be expected, the interaction of three or more waves in such a medium leads to additional surprising effects, perhaps the most remarkable of which is phase conjugation.
Spurious Beams
Authors: Solymar L , Webb D J , Grunnet-Jepsen A 
Published: November 2023

Abstract
A spurious beam may be defined as a beam which by certain simple considerations should not be there. For example, if we have one or more beams incident upon a piece of ordinary optical material (say, a window pane) the expectation is that apart from a small attenuation the beams will be unchanged. When it comes to photorefractive materials we know that the various beams may interact with each other and consequently their relative output intensities may change. But can the beams wander away from their original paths or, even worse, can new beams arise out of nothing? Yes, we have discussed such phenomena a number of times in this book: higher diffraction orders in Section 3.8, ring resonators in Section 3.11, the double phase conjugate mirror in Section 3.12, and a string of phase conjugate resonators in Section 7.6. And of course self-phase-conjugation of the types shown in Figs 7.15 and 7.18 are prime examples of beams appearing rather unexpectedly and following rather unconventional paths. So why do we need an extra chapter on spurious beams? The reason is that apart from the examples quoted, there are still plenty of configurations in a number of photorefractive materials which lead to the appearance of new beams and for which some classification is desirable.
General Introduction
Authors: Solymar L , Webb D J , Grunnet-Jepsen A 
Published: November 2023

Abstract
In this third section of the book, we address as best we can in the space available the enormous range of applications that have been proposed for photorefractive materials. We should start by saying exactly what we mean by applications. At the time of writing, whilst a few prototype devices have been produced that make use of some form of photorefractive signal processing element, these have almost all been constructed as technology demonstrators, and there is to our knowledge only one commercial product on the market (Rakuljic and Leyva 1993). Nevertheless, there is hope that with the rapid progress being made in photorefractive materials research it will not be long before other photorefractive devices do achieve commercial success.
Correlation And Associative Memories
Authors: Solymar L , Webb D J , Grunnet-Jepsen A 
Published: November 2023

Abstract
As we have already discussed, one of the main advantages of signal processing using non-linear optics as opposed to digital electronics is the ability to handle potentially large quantities of information in parallel. Image processing is an area that lends itself naturally to optical techniques, and in this field two of the most important operations that must be performed are those of convolution and especially correlation. In this chapter we shall see how these operations may be performed using non-linear optics and how the process of correlation may be used to realize an associative memory.
Performance prediction for switched reluctance motors (two-and three-dimensional)
Authors: Reece A B J , Preston T W 
Published: November 2023

Abstract
A common procedure is to neglect coupling between phases and to predict flux linkages with an excited phase as a function of angle and current. Circuit equations, which include a model of the converter, are then used to calculate the phase current and flux linkages as a function of time, assuming speed to be constant. The torque produced can be derived from rate of change of coenergy as described by Stephenson and Corda (1979).
Future developments
Authors: Reece A B J , Preston T W 
Published: November 2023

Abstract
Perhaps this account of the principles of finite clement modelling and the examples of its application in electrical power engineering suggests that the subject has reached a plateau in its ability to contribute to good design. There is no doubt that the technique is well established, but there is much development still going on, and new techniques are also pushing their way into engineering applications. Thus an attempt to look into the future seems justified, as a conclusion to this book. First however it may be of interest and value to review briefly the present situation and recall how this has been reached. This review will be very much a personal view, based on the authors’ involvement over some 30 years.
Time-domain Optics of Ultrashort Waveforms
Authors: Shyartsburg A B 
Published: November 2023

Abstract
Time domain transient electrodynamics of dispersive and glossy media form the subject of this book. This topic is associated with the unusual interactions between ultra-short transient signals and these media. Techniques based on such interactions find use in materials analysis, fractal communication, and energy transfer through dispersive and absorbing media, Traditional analytical techniques (Fourier based) break down in the extreme conditions encountered in these situations; Shvartsburg gives here other successful techniques and methods to allow scientists to analyse and model this behaviour.
Segmentation and Grouping
Authors: Rothwell Charles A 
Published: November 2023

Abstract
Segmentation is important because it provides the features required for shape description; these have to be localized and then represented in a suitable manner. This chapter describes the segmentation and grouping algorithms that are used by the two planar recognition systems described in the previous chapters that use the LEWIS architecture. All of the algorithms that will be described can be substituted directly into the architecture.
A horologist in the making
Authors: Woodward Philip 
Published: November 2023

Abstract
The detour through the arboretum gave us time to collect a fresh supply of conkers, but we had to judge things carefully if we were not to be late for school. An old gentleman taking his morning walk in the park might possess the time, but he could prove grumpy when accosted by a couple of seven-year-olds in caps. We would put on our humblest expressions and ask for ‘the right time, please’, a manoeuvre that could be self-defeating as it would take him an age to reach into his pocket, extract the watch and open it up. Gold hunters on chains were the watches we preferred, though it soon became obvious that the time we were given was unlikely to tally with the school clock. Indeed, watches never agreed with one another, and I was becoming obsessed with the desire to have my own ‘right time’, accurate to a minute. My father had said it could always be obtained at the Post Office, an observation firmly grounded in history but one that seemed to have little relevance to my immediate needs.
Silence for a cellist
Authors: Woodward Philip 
Published: November 2023

Abstract
The quiet clock I needed for the music room would be my first essay in purely mechanical clockwork, not counting the early Meccano effort, and for obvious reasons I wished to sidestep as many gears as I could. If an escapement could be designed in such a way that the escape wheel would turn in an hour instead of the more usual minute, it should be possible to make an eight-day clock with only a single gear mesh. The need for silence made me abandon the idea of a gravity escapement, and I began to think of Harrison’s grasshopper. Perhaps some similar principle could be used for intermittent impulsing.
The Shortt free pendulum
Authors: Woodward Philip 
Published: November 2023

Abstract
There is no such thing as a free pendulum, because a pendulum can never be totally isolated from its environment. If it could, its Q would be infinite and we would have perpetual motion. Freedom has always been an unattainable ideal, but the degree to which it has been approached is truly remarkable, so much so that the term free pendulum need hardly be regarded as a contradiction in terms. An earlier concept was that of detachment, which is more easily defined.
The Equatorial Ionosphere And Radio Communications
Authors: Reddy B Madhava 
Published: November 2023

Abstract
The primary objective of the international union of Radio Science (URSI) has always been stimulating research on radio and telecommunications. The physics and propagation aspects of ionosphere were kept integrated until the fifties largely by stalwarts like Appleton. But with the considerable expansion in ionospheric research, especially after the International Geophysical year (1957-58), it tended to split distinctly as the propagation and physical aspects diverged [Rishbeth, 1994].
Personal communication services - technology and health concerns: is there a common solution?
Authors: Smchly Maria A 
Published: November 2023

Abstract
With the expansion of current use and anticipated further increases in the use of cellular telephones and other personal communication services (PCS), there have been an interest and considerable research effort devoted co interactions between antennas on hand-sets and the human body. The motivation for research in this area is due to two factors. From the technology point of view, as many of the PCS devices are used close co the human body, the latter results in a deterioration of the antenna performance and may therefore either require operation with increased power or other means chat prevent the deterioration of communication. From the health point of view, concern arc expressed that the deposition of microwave power in some locations may be excessive and therefore lead to detrimental health effects.
Why use steam?
Authors: Semmens P W B , Goldfinch A J 
Published: November 2023

Abstract
Although every enthusiast knows what a steam locomotive is like, to be able to understand how it works in detail we must first look at its fundamental characteristics and the physical, chemical and engineering laws under which it operates.
A steam locomotive is a ‘heat engine’, which converts the chemical energy of the fuel it burns into useful work hauling trains. It does this by turning water into steam, which it uses as a working fluid to drive the pistons and coupled wheels. The important thing about the efficiency of this process is not the boiler pressure, of itself, but the temperature range over which this working fluid operates. Nor is the water/steam system the only one that could be used-indeed, because the steam in a locomotive’s cylinders is only slightly above its condensing temperature, the mean pressure as it expands is not as great as it would be with other working fluids.
Burning the fuel
Authors: Semmens P W B , Goldfinch A J 
Published: November 2023

Abstract
The steam locomotive was originally developed for the private railways in the coalfields of Britain, and, not surprisingly, coal was used as the source of heat. Almost immediately after public railways had subsequently started to spread across the country, legislation, in response to public opinion, required locomotives ‘to consume their own smoke’. Initially this was not easy to achieve with coal, and there was a wholesale switch to coke as a fuel. Coke had first been a byproduct of William Murdock’s process to produce gas for illumination purposes, which he had made by heating coal in a closed retort some three decades before the first practical steam locomotive appeared. The techniques were well developed by the time railways had to conform to the new legislation, and coke manufacture took place at numerous locomotive depots around the country.
Raising steam
Authors: Semmens P W B , Goldfinch A J 
Published: November 2023

Abstract
The boiler, usually constructed integrally with the firebox, is the largest single component of a steam locomotive, and dominates its appearance. However, it contains few moving parts, and from an engineering point of view is a relatively simple unit. It nevertheless requires conscientious servicing and maintenance, and a good grasp of its technology is vital for anyone wanting to understand all the workings of the steam locomotive. Diagrams showing longitudinal- and cross-sections of small and large locomotive boilers appear in Figs 3.1 and 3.2.
The locomotive as a vehicle
Authors: Semmens P W B , Goldfinch A J 
Published: November 2023

Abstract
To understand the problems of stability with steam locomotives, we must go back nearly 150 years before the construction of Rocket, to when Isaac Newton formulated his three ‘Laws of Motion’. Some of their implications have already been touched on earlier in this book, but it is now worth stating them formally, as follows:
Law 1 Every body continues in its state of rest or uniform motion in a straight line, unless impressed forces act upon it.
Law 2 The change in momentum per unit time is proportional to the impressed force, and takes place in the direction of the straight line along which the force acts.
Fuel fabrication
Authors: Marsh G , Eccles H 
Published: November 2023

Abstract
The two principal types of fuel in current use are based respectively on uranium metal and uranium oxide. (Thorium oxide can also be used but is not widely adopted, despite considerable interest on the part of the Indian nuclear industry where relative abundance and a desire for technological independence tend to counterbalance its disadvantages.) Metal can be used in the form of massive rods, which are conveniently handled individually. The oxide has a much lower conductivity; it is therefore formed into thinner rods or pinsand to avoid unnecessary handling operations within the reactor these are built up into clusters, assemblies, bundles, elements or sub-assemblies (the terminology varies according to the type of reactor, but with much the same meaning) which may each contain several hundred.
Power reactors
Authors: Hesketh K W 
Published: November 2023

Abstract
The nuclear fission reactor is the central element of the fuel cycle, generating the energy that is the primary aim of the industry. It is also the source of fission and transmutation products presenting opportunities and problems in succeeding stages. Various designs have been developed for central power generation and for more specialised applications; the purpose of this chapter is to describe the principles and main practical features of the more important types.
Transport and storage of irradiated fuel
Authors: Haslett D E 
Published: November 2023

Abstract
The storage and transport of irradiated nuclear fuel, although not strictly process stages in the cycle, are nevertheless essential links between those stages. As finally discharged from the reactor, fuel represents to the operating utility a liability requiring disposal, whether directly or through a reprocessing plant that can recover materials for re-use. Meanwhile it must be kept under conditions protecting public and work-force from its radioactivity, while preserving the integrity of its structure. The world stock of stored irradiated fuel in 1993 is estimated to have been 95 000 metric tons of heavy metal (MTHM), that is the amount of uranium plus plutonium.
Decommissioning nuclear facilities
Authors: Buck S 
Published: November 2023

Abstract
Nuclear facilities at the end of their useful lives cannot merely be abandoned. The site may be needed for other purposes, amenity must be preserved, and above all else, the public must be protected from any remaining hazards. Decommissioning is a major world-wide task: the IAEA has estimated that some 50 nuclear power plants and over 220 research reactors are already shut down, by the year 2000 a further 40 and 230 respectively will be at least 30 years old,la and supporting facilities, such as the successive British Magnox reprocessing plants, must eventually be included.
Inverse Problems Related To Fields From Localized Sources Over A Stratified Half-Space
Authors: He Sailing , Strom Staffan , Weston Vaughan H 
Published: November 2023

Abstract
Inverse problems involving a localized source over a stratified half-space are relevant in many different contexts, such as non-invasive investigations of subsurface physical properties by means of acoustic, electromagnetic or elastodynamic waves. In the present chapter the previous treatment is generalized inasmuch as instead of normally or obliquely incident plane waves, we now consider more general incident fields generated within a bounded region. The main assumption about the half-space to be investigated is the same as before, i.e., it is assumed to be plane-stratified. For these more general incident fields it is shown how the use of suitably defined moments of the fields and the reflection kernel can be used to solve inverse problems. In particular it is shown how the use of the zeroth, second and fourth moments of the three-dimensional fields reduce the inverse problem to a set of one-dimensional problems. When one has additional symmetry properties of the incident field, such as axial symmetry, it is shown how the inverse problem is reduced to a one-dimensional problem through the use of a Hankel transform. In this case an explicit form of the wave-splitting operator is found in the Hankel transformed space. The Green’s function formalism for this case is developed. The explicit form of the wave-splitting is also used to treat wave propagation in homogeneous plasmas, dispersive media and waveguides.
The spectral properties of equilibrium fluctuations
Authors: Scaife B K P 
Published: November 2023

Abstract
In our discussion of multipolar fluctuations in the previous chapter we were primarily concerned with ensemble averages of fluctuating quantities since we were interested in the magnitude of the fluctuations without any need to advert directly to their temporal behaviour. Here we shall examine the evolution in time of multipolar fluctuations by means of the autocorrelation function and the spectral density. The latter concept enables us to discuss some of the topics dealt with in the previous chapter from a different point of view.