bluuebunny/crossref_metadata_2025_split huggingface dataset:
Introduction
Authors: Chapman Jonathan , Rowbottom Frederick 
Published: November 2023

Abstract
The logical approach to topos theory, working with a language for a topos, has been hampered by difficulties in tackling proofs involving a geometric morphism (the most important notion of morphism between topoi). This is unfortunate, since a topos gives a radical notion of ‘set’ (or at least, of higher-order logic) and this approach deals with it as such.
The relative Giraud theorem
Authors: Chapman Jonathan , Rowbottom Frederick 
Published: November 2023

Abstract
Giraud first proved the theorem, relative to Set (Grothendieck and Verdier (1972, IV.1.2)). See also Makkai and Reyes (1977, 1.4), Johnstone (1977, 0.45), Barr (1985, 6.8). Mitchell found an elementary description of the existence of a set of generators (cf. Fourman (1977), Fourman and Scott (1979)). Then Diaconescu gave a categorical proof of the Giraud theorem relative to an arbitrary base topos (cf. Diaconescu (1975) or Johnstone (1977, 4.46)). Our proof internalizes the one given in Chapman (1982, Chapter 3) (the general form of which is similar to Johnstone (1977, 0.45)). It is not necessary for the reader to have seen any of the above proofs, in order to follow ours.
Nonlinear Waves in Elastic Crystals
Authors: Maugin Gerard A 
Published: November 2023

Abstract
The mathematical modelling of changing structures in materials is of increasing importance to industry where applications of the theory are found in subjects as diverse as aerospace and medicine. This book deals with aspects of the nonlinear dynamics of deformable ordered solids (known as elastic crystals) where the nonlinear effects combine or compete with each other. Physical and mathematical models are discused and computational aspects are also included. Different models are considered - on discrete as well as continuum scales - applying heat, electricity, or magnetism to the crystal structure and these are analysed using the equations of rational mechanics. In this way the student is introduced to the important equations of nonlinear science that describe shock waves, solitons and chaos and also the non-exactly integrable systems or partial differential equations. A large number of problems and examples are included, many taken from recent research and involving both one-dimensional and two-dimensional problems as well as some coupled degress of freedom.
Different types of Crystals
Authors: Maugin Gerard A 
Published: November 2023

Abstract
This introductory chapter is descriptive in nature. It aims at defining all the ingredients of propagation of waves, which constitute the principal object of our study in this book.
The common, in fact exact, view is the following one. Materials are classified as gases, liquids and solids, depending upon their state of aggregation and their ability to deform and flow. Thus, the binding interactions and the configurations of constituents in the material and their observed dynamics typically characterize the classification of materials. Based on their structure, solids can be classified as monocrystalline, polycrystalline and amorphous-crystalline.
Nonlinear waves in elastic chains
Authors: Maugin Gerard A 
Published: November 2023

Abstract
Among the wave-like manifestations of nonlinearity one must distinguish between quasi-linear dynamical processes and the truly nonlinear ones. Harmonic generation, anisochronism, intermodulation, dynamic echo, acoustic mixing and parametric interactions belong to the first category, which is extensively dealt with in another treatise (Maugin et al., 1992b) Chapter 3 on elasticity and electroelasticity. Harmonic analysis, together with the notions of small amplitude and expansion in small parameters, remains a basic mathematical tool for these processes. The second class of processes essentially consists of shock waves, solitary waves and solitons.
Continuum theory for biaxial nematic liquid crystals
Authors: Leslie F M , Laverty J S , Carlsson T 
Published: November 2023

Abstract
This paper presents a formulation of continuum theory for biaxial nematic liquid crystals based upon balance laws for linear and angular momentum, and derives directly expressions for stress and couple stress. The theory so obtained is more general than the earlier theory by Saupe, having more terms in the viscous stress, but by determining conditions that this stress is derivable from a dissipation function, one recovers his version, this requiring four Onsager-Parodi relations.
A Schur-complement method for sparse quadratic programming
Authors: Gill Philip E , Murray Walter , Saunders Michael A , Wright Margaret H 
Published: November 2023

Abstract
In applying active-set methods to sparse quadratic programs, it is desirable to utilize existing sparse-matrix techniques. We describe a quadratic programming method based on the classical Schur complement. Its key feature is that much of the linear algebraic work associated with an entire sequence of iterations involves a fixed sparse factorization. Updates are performed at every iteration to the factorization of a smaller matrix, which may be treated as dense or sparse.
On the conditioning of parameter estimation problems
Authors: Varah James M 
Published: November 2023

Abstract
We examine the problem of determining numerical values for parameters appearing in differential equations modelling physical phenomena. There are several factors involved in the accuracy or sensitivity of the parameters; we attempt to separate these with the intention of identifying those associated with the model itself. We also indicate means of effectively computing these conditioning factors, so that proposed models can be properly evaluated. Finally, we briefly mention recent work on non-linear statistical effects, and attempt to bring this into the same context.
Experiments in tearing large sparse systems
Authors: Arioli Maria , Duff Iain S 
Published: November 2023

Abstract
If one removes some variables and equations from a large sparse system of linear equations, the resulting subsystem may have characteristics which render it amenable to rapid and economic solution. There are then various methods for obtaining a solution to the original system. This class of techniques is often termed ‘tearing’ and has been widely used in several application areas including linear programming, chem¬ ical engineering, and economic modelling.
Iterative refinement and reliable computing
Authors: Bjorck Ake 
Published: November 2023

Abstract
The classical use of iterative refinement is to compute highly accurate solutions to linear systems using residuals accumulated in double precision. The solution to be refined is assumed to have been computed by a backward stable algorithm. A different use of iterative refinement is to make an unstable algorithm numerically stable. In this case often a single step of refinement using single-precision residuals suffices. This contribution gives both a brief review of the early development and surveys more recent applications of iterative refinement of solutions to linear systems.
Products of nilpotent groups
Authors: Amberg Bernhard , Franciosi Silvana , Giovanni Francesco De 
Published: November 2023

Abstract
In the early 1950s finite products of two nilpotent groups were considered by several authors, and the conjecture arose that these groups were always soluble (Huppert 1953; Ito 1951; Szep 1951; Wielandt 1951). This seemed to be an unusually difficult problem, even for products of two abelian groups. However, in 1955 Ito, using a surprisingly short commutator calculation, obtained the following famous result, which even holds for arbitrary groups.
Linearized Oscillation Theory And Applications To Mathematical Biology
Authors: Györi I , Ladas G 
Published: November 2023

Abstract
In this chapter we shall develop and apply a linearized oscillation theory which, in a sense, parallels the so-called linearized stability theory of differential and difference equations. As in the case of stability theory, we prove that certain non-linear delay differential equations have the same oscillatory behaviour as an associated linear equation. The linearized oscillation theory has been motivated by applications.
Propositional Logic Programming
Authors: Mints G 
Published: November 2023

Abstract
We describe the application of propositional (mainly intuitionhtic and modal) logic in logic programming. Logic programming is understood here in the broad sense of non-procedural programming in terms of logical specifications (Tyugu 1986), so that the compilation of the result ing program (i.e., program synthesis) is performed essentially by means of automatic proof search in a suitable logical system. We review the logical features of the programming system PR1z developed at the Institute of Cybernetics of the Estonian Academy of Sciences. More detailed descriptions of the system architecture and proofs of some results can be found in Mints and Tyllgu (1982, 1987).
Error Tolerant Learning Systems
Authors: Sammutt C 
Published: November 2023

Abstract
We consider the task of a robot learning in a reactive environment by performing experiments. A reactive environment is one where changes occur in response to actions. Actors other than the learner may be present in the world. The robot performs experiment by modifying the environment and observing the outcome. These observations lead to a collection of concepts which constitute a theory of the behaviour of the environment, also called a world model. An experiment may either increase confidence in a theory or refute a theory, but it can never prove a theory. Therefore it is possible that the robot will develop an in accurate model of its world. This paper discusses a number of issues involved in finding and repairing faults in a world model. It also describes some preliminary results obtained from a learning program called CAP.
A Qualitative Way of Solving the Pole Balancing Problem
Authors: Makarovic A 
Published: November 2023

Abstract
A method is presented for designing a control rule for the well-known pole-cart system. Conventional techniques arc used to model the pole cart system by a set of differential equations. The high complexity of the model prohibits a direct derivation of the control rules. The model can be simplified by restructuring and approximating the equations. We allow very rough approximations, as long as the essence of the problem stays the same. Ultimately we get a very simple model. Designing a control rule for this model is an almost trivial problem.
Introduction
Authors: Hankin Chris 
Published: November 2023

Abstract
We informally introduce the A-calculus and introduce the reader to a number of concepts and techniques which will recur throughout the book. We start with a discussion of the role of functional abstraction in Computer Science; this leads naturally to an informal presentation of the A-calculus. The A-calculus is an example of a formal system; we include a brief introduction to formal systems. Our treatment of the material in this book is quite rigorous; we include proofs of most of the main results and where we do not, the reader is encouraged to provide them (in the exercises). The majority of proofs are inductive; we will introduce the different forms of inductive argument as required but we conclude this chapter with a revision of mathematical induction.
Notation and the Basic Theory
Authors: Hankin Chris 
Published: November 2023

Abstract
We now start our study of the A-calculus. First, we return to the question of notation and present an inductive definition of A-terms and some auxiliary notions such as free variables and subterms. Next, we present the theory. Central to the theory is the notion of substitution - the driving force behind function application - we next discuss a number of alternative approaches to defining substitution and consider some of the properties of substitution. The theory is a theory of equality between terms; as indicated in the last chapter, we are trying to capture intensional equality but we also show how the theory can be extended to capture extensional equality. Finally, we consider the consistency and “completeness” of the two theories presented. We will give an inductive definition of A-terms. This style of definition may be slightly unfamiliar to Computer Scientists so we start by illustrating the approach in the context of the (more familiar) propositional calculus.
Types
Authors: Hankin Chris 
Published: November 2023

Abstract
The type-free A-calculus has been presented as a prototypical functional programming language. While it is true that many of the issues that we have studied have direct relevance to programming practice, the theory fails to match the practice in a number of important ways. The majority of modern functional programming languages are typed. As a consequence, we can no longer construct certain terms which play a key part in the foregoing theory. In this chapter we present three typed calculi. First we consider the simply typed A-calculus; this calculus is derived from the typefree A-calculus in a fairly direct way but has a rather different character as a result of the typing. For example ,8-reduction in the typed A-calculus is strongly normalising.
Practical Issues
Authors: Hankin Chris 
Published: November 2023

Abstract
In this chapter we turn to more practical aspects of the A-calculus. One form of standard reduction sequence (see Chapter 3) is a leftmost sequence (reduce the leftmost redex at each stage); this is also called normal order reduction. Lazy evaluation systems use this reduction order (see later). A redex is outermost if it is not contained in any other redex, it is innermost if it does not contain any redexes. An alternative reduction strategy, called applicative order, is leftmost innermost. The features of the various evaluation strategies have been sloganised by Mycroft in terms of the way in which parameters are treated.
Software Metrics Reviewed
Authors: Laidler Keith J 
Published: November 2023

Abstract
This chapter reviews developments in the field of software metrics from the early 1970s to the present time. Metrics can be categorized according to the stage of software development with which they are associated. Thus we have code metrics, design metrics, and specification metrics. Although our primary interest in this book is with software designs, code measures will also be examined. The chapter indicates briefly that the area of software metrics is afflicted by a number of serious problems, a theme expanded upon in the following chapter. This chapter is a brief review of work carried out in the metrics area over the last three decades. In a number of ways both this chapter and Chapter 3, which describes three metrics in detail, present a rather bleak view of what is a potentially promising and important field of software engineering. There are several recurring themes in both the chapters. First, the majority of metrics are presented in such a fashion that it is unclear exactly what is being measured. Terms such as ‘complexity’ and ‘quality’ proliferate. As a direct result, empirical evaluations have interpreted metrics in widely differing ways. Divergent results have ensued for every metric evaluated above. Almost the only unifying feature has been the strong statistical associations with size metrics such as lines of code.*
An Approach To Metrics Modelling
Authors: Laidler Keith J 
Published: November 2023

Abstract
So far in this monograph we have described a number of serious problems that afflict the metrics area. Also, in the preceding chapter, we have examined some ways in which researchers have attempted to put the study of metrics on a more formal footing. This chapter first examines a promising recent approach to metrics development – the GQM method – and then outlines our approach to metrics development. This approach is based on adapting the axiomatic approach outlined in the preceding chapter and modifying the GQM method. We present a small, artificial example to describe the approach. There has been little effort directed towards development methods for software metrics, in part due to the belated realization of the problems involved in the field. Two of the few contributions of significance are the Goal – Question – Metric (GQM) paradigm of Victor Basil et al. and the constructive quality model (COQUAMO) methodology, which employs a similar hierarchic approach based around software quality factors, criteria and metrics. However, given the importance of the model for software measurement, GQM is only a partial methodology. In the final parts of this chapter we extend this metric development methodology so that it recognizes the central role of a model explicitly; and this is illustrated by a simple example. A fuller example is presented Chapter 6.
A Uni–Dimensional Model Of Design
Authors: Laidler Keith J 
Published: November 2023

Abstract
Synopsis In the absence of a clearly articulated model, software measurement is a fruitless exercise. In the preceding chapter we sought to remedy this situation by proposing a method to aid the development and evaluation of software metrics, together with their underlying models. This was illustrated by an extremely simple example. This chapter describes a larger software engineering problem for which we develop a model to relate software design to the quality factors of implementability, reliability, and maintainability. A formal model is developed and evaluated using the apparatus of the method outlined in the preceding chapter. Each step in the development of the model is outlined: problem identification, construction of an informal model, statement of the formal model, and axiomatization of the model. This is followed by theoretical and empirical validations. The chapter concludes that more than one model input – or multi–dimensional modelling – is necessary to improve the model performance and provide useful support for the software engineer carrying out design tasks. It is important to point out that in this chapter we are not attempting to promote one system design metric, but, rather, are using a particular metric as an example of the metric development process that was described in the preceding chapter.
A Multi–Dimensional Model Of Design
Authors: Laidler Keith J 
Published: November 2023

Abstract
This chapter mirrors the model development process in that it replaces the simpler model of software design described in the preceding chapter with a more sophisticated multi–dimensional model. We demonstrate our metrics development technique in deriving a metric associated with this model. A major conclusion that emerges from the chapter is that if software engineering models are to be useful, then they will require more sophistication than can be achieved by a single input or dimension. In particular, it shows that some of the weaknesses of the model of system architecture described in the preceding chapter may be overcome by extending it to incorporate a notion of module, or design component size. This permits the exploration of trade–offs between inter– and intra–modular information flows. The conclusion is drawn that the techniques employed in this and the preceding chapter enable more sophisticated and useful software models to be developed. However, this must build upon the foundation of theoretically clean and empirically observed relationships. Otherwise, our sophistication is entirely in vain.
Machine Intelligence 15
Authors: Furukawa K , Michie D , Muggleton S 
Published: November 2023

Abstract
This is the fifteenth volume in the Machine Intelligence series, founded in 1965 by Donald Michie, and includes papers by a number of eminent AI figures including John McCarthy, Alan Robinson, Robert Kowalski and Mike Genesereth. The book is centred on the theme of intelligent agents and covers a wide range of topics, including: - Representations of consciousness (John McCarthy, Stanford University and Donald Michie, Edinburgh University) - SoftBots (Bruce Blumberg, MIT Media Lab) - Parallel implementations of logic (Alan Robinson, Syracuse University) - Machine learning (Stephen Muggleton, Oxford University) - Machine vision (Andrew Blake, Oxford University) - Machine-based scientific discovery in molecular biology (Mike Sternberg, Imperial Cancer Research Fund).
Bioluminescence in the Appendicularia
Authors: Galt Charles P , Flood Per R 
Published: November 2023

Abstract
Bioluminescence is a conspicuous feature of many marine organisms, and among the pelagic Tunicata it is well documented in the Pyrosomida (section 1.2.2) and in certain oikopleurid Appendicularia, whose mucoid feeding houses emit light. Giglioli (1870), who reported multicoloured luminescence from the tail of unidentified species of appendicularians, probably actually observed iridescence from the caudal muscle bands, as there is no evidence of caudal luminescence or multiple wavelength emissions from a single animal. We owe to Hans Lohmann (1899a, 1933) the first reliable accounts of light production by appendicularian tunicates. He described brilliant greenish flashes emanating from the trunks of free-swimming Oikopleura albicans as they made contact with surfaces or were otherwise agitated. He further reported that during expansion of the house a brilliant light emanated continuously from the animal’s trunk, (he speculated that such luminescence would serve to deter predators during this vulnerable operation). The expanded house (as Lohmann observed) also produces light from unknown but consistently organized sources in response to agitation or prodding. Finally, Lohmann noted that even discarded houses emitted flashes upon stimulation. Lohmann suggested that light was produced by ‘fluorescent’ secretions from the oral glands and from parts of the oikoplast epithelium. Since other species, including members of the Fritillariidae, produced similar secretions, Lohmann (1933) supposed that all appendicularians were luminescent. Harvey (1952) concluded from Lohmann’s
Multiple-foundress associations in sweat bees
Authors: Packer Laurence 
Published: November 2023

Abstract
A sweat bee biologist writing about multiple foundress associations faces two main problems: the wide range of subtly different organizational patterns exhibited by such societies and the dearth of detailed information on the topic. Three additional difficulties apply to any explanations of sweat bee sociobiology aimed at a more general audience. First, it is difficult to apply standard terms such as ‘queen’ and ‘worker’ to individuals in many sweat bee societies. In most eusocial Hymenoptera the queen lays most, or all, of the eggs and is often easily distinguished from workers with the naked eye. In some sweat bees the queen may have higher egg production than individual workers only by living longer (Packer and Knerer 1986) and may only be distinguished from workers through long term behavioural observation or dissection (see Michener 1990). Second, the large amount of intraspecific (even intra-population) variation in social organization makes it hard to characterize individual species as exhibiting one particular named social category. An individual colony may switch from one type of social organization to another (even on to a third, or back to the first) during one season. Lastly, halictids are a taxonomically complex group and there is no general agreement as to their higher level classification. As a result, generic name changes are common and we do not have even an approximate phylogeny at the genus level upon which to base polarity decisions for behavioural characters.