bluuebunny/crossref_metadata_2025 huggingface dataset:
Strategies in problem solving
Authors: Tao Terence
Published: November 2023

Like and unlike the proverb above, the solution to a problem begins (and continues, and ends) with simple, logical steps. But as long as one steps in a firm, clear direction, with long strides and sharp vision, one would need far, far less than the millions of steps needed to journey a thousand miles. And mathematics, being abstract, has no physical constraints; one can always restart from scratch, try new avenues of attack, or backtrack at an instant’s notice. One does not always have these luxuries in other forms of problem-solving (e.g. trying to go home if you are lost).
Examples in number theory
Authors: Tao Terence
Published: November 2023

Number theory may not neccesarily be divine, but it still has an aura of mystique about it. Unlike algebra, which has as its backbone the laws of manipulating equations, number theory seems to derive its results from a source unknown. Take, for example, Lagrange’s theorem (first conjectured by Fermat) that every positive integer is a sum of four perfect squares (e.g. 30 42 32 22 12). Algebraically, we are talking about an extremely simple equation: but because we are restricted to the integers, the rules of algebra fail.
Minimal models
Authors: Félix Yves , Oprea John , Tanré Daniel
Published: November 2023

A minimal model is a particularly tractable kind of commutative differential graded algebra (cdga) that can be associated to any nice cdga or to any nice space. The word “minimal” emphasizes that, at least in many cases of interest, the model is calculable. The amazing feature of minimal models of spaces is their ability to algebraically encode all rational homotopy information about a space. This is, of course, why minimal models are important. This chapter includes definitions and the main properties of algebraic notions related to minimal models.
Geodesics
Authors: Félix Yves , Oprea John , Tanré Daniel
Published: November 2023

Let M be a smooth Riemannian manifold. The Riemannian structure of the manifold is reflected in the form its geodesics take. For instance, we see the symmetry of the sphere S  2 (with the Riemannian structure induced from R3) in the great circles that are its geodesics. Moreover, while the differential geometric structure of a physical system is detected by geodesics (e.g. in general relativity), the actual physical nature of such a system is seen in its motions. A beautiful result of Jacobi (see [216, Chapter 8] for instance) says that the Riemannian metric on the manifold of interest may be modified in a simple way so that the geometric and physical viewpoints agree; namely, the motions of the system are along geodesics with respect to the new metric.
Learning to Lobby the European Union: 20 Years of Change
Authors: Coen David , Richardson Jeremy
Published: November 2023

It is universally accepted that there has been a huge growth in European Union (EU) lobbying, at the EU and national levels, over the past two decades. There is now a dense EU interest group system and a concurrent explosion of EU interest groups studies (Mazey and Richardson 1993; Kohler-Koch and Eising 1999; Coen 2007; Beyer et al. 2008). However, while much progress has been made in collating interest group populations (Butt Philip 1989; Greenwood 1997, 2005; Berkhout and Lowery 2008), discussing mobilization strategies (Coen 1998; Beyers 2002; Eising 2004), and identifying access criteria to institutions (Bouwen 2002; Broscheid and Coen 2003), few studies have explained the full ‘EU lobbying footprint’ in a multilevel and institutional environment. This volume seeks to understand the role of interest groups in the policy process from agenda-setting to implementation.
Plane Autonomous Systems And Linearization
Authors: Jordan D W , Smith P
Published: November 2023

Chapter 1 describes the application of phase-plane methods to the equation x f (x, x) through the equivalent first-order system x y, y f (x, y). This approach permits a useful line of argument based on a mechanical interpretation of the original equation. Frequently, however, the appropriate formulation of mechanical, biological, and geometrical problems is not through a second-order equation at all, but directly as a more general type of first-order system of the form x X(x, y), y Y (x, y). The appearance of these equations is an invitation to construct a phase plane with x, y coordinates in which solutions are represented by curves
Perturbation Methods
Authors: Jordan D W , Smith P
Published: November 2023

This chapter describes techniques for obtaining approximations to periodic time solutions of nearly linear second-order differential equations subject to a harmonic forcing term, and to limit cycles of autonomous equations. The approximations take the form of an expansion in integer powers of a small parameter, having coefficients that are functions of time. There is some freedom in assigning the time-dependent coefficients; this is utilized to produce uniformly valid approximations under different circumstances, depending on the values of the main parameters of the equation. It is also shown how a homo-clinic path can be approximated by using similar methods. The processes reveal physical features having no analogue in linear theory, despite the fact that the equations considered have small nonlinearities.
The Beak of the Finch
Authors: Cronbach Lee
Published: November 2023

The finches of the Galápagos Islands are justifiably famous for inspiring Darwin’s theorizing about evolution. There are some nineteen sizable islands and dozens of smaller islets in the Galápagos archipelago. Each one has a slightly different flora, and therefore each presents a slightly different challenge for a small bird in search of dinner. What Darwin noticed in his time on the Galápagos was that the finches on different islands had slightly different beaks. Where there were large seeds to be cracked, beaks were thick and powerful. Where there were holes to be explored, beaks were thin and slender. Darwin’s explanation was that although the finches had all descended from a common ancestor, those
Wanderers
Authors: Nettle Daniel
Published: November 2023

Erica, at 55, is living a quiet life. Her pretty cottage in the downland of southern England stands in a little wooded valley, where, she tells me, deer and rabbits are her neighbours. At around 8am, she drives her little hatchback ten miles up the road to an office in another out-of-town location, which she shares with a couple of other journalists who work with her on her small magazine. She gets on well with her colleagues, but after work, her day is quiet; she drives back, with no rush-hour traffic to worry about, makes dinner, watches some television, and goes early to her bed, where she has, as she puts it ‘vivid, entertaining, cinematic and revealing dreams’.
Worriers
Authors: Nettle Daniel
Published: November 2023

Some people seem to get all the bad luck. Susan seems to have hit on a seam of bad men. As her high-school years in a London suburb drew to a close, she was pondering what to do with her life next. The teachers thought she was good enough—the brightest they had ever taught, in fact—to try the competitive entrance examination for Oxford University. However, not only would she not do this, but she would not even put in an application for a second-tier, or any other, university instead. She had a notion she would apply to Art School, but after making a fact-finding visit, she found the rate of attrition from the course too worrying.
Empathizers
Authors: Nettle Daniel
Published: November 2023

Suppose for a moment you have been lured into a laboratory by a psychologist. You are seated in a small cubicle, with a clear glass front. You are hungry. Just opposite you, the other side of a narrow corridor, is someone you know. He looks like he is in the same boat as you. In front of you are two levers. One of them, you have worked out, will bring a tray that is currently out of reach into your reach though a gap in the glass wall. On that tray is a glass of chilled water and something nice to eat. The second lever will also bring your tray into your reach, and additionally cause a similar tray to be moved into the reach of the man opposite.
Geometrical aspects of plane autonomous systems
Authors: Jordan D W , Smith P
Published: November 2023

3.1. (a) Surround the equilibrium point by a closed curve r (see Figure 3.1). Take any point P on r, and draw a vector S at P tangential to the phase path at P . Let Φ be the angle between a fixed direction and S measured counterclockwise as shown. As P makes one counter clockwise circuit of r, determine how the angle Φ changes as the direction of S changes. Any change will be a multiple of 2π . In this example Φ returns to its original value. Hence the index I 0.
Periodic solutions; averaging methods
Authors: Jordan D W , Smith P
Published: November 2023

The system (i) has one equilibrium point at the origin. From (ii) it can be seen that r = 1 is a phase path representing a periodic solution taken in the clockwise sense since θ˙ is negative. The path is a stable limit cycle since r > 0 for r < 1 and r < 0 for r > 1. The polar equations for the phase paths can be obtained by integrating which is the same equation as in (i). Therefore the phase diagram is the same as that shown in Figure 4.1 except that the direction of the phase paths is reversed.
Singular perturbation methods
Authors: Jordan D W , Smith P
Published: November 2023

How does the period obtained by the method of Problem 6.1 compare with that derived in Problem 1.34? In Problem 6.1 the initial condition given is x(0) = 1. This can be changed to a by the substitution of x = X/a into the differential equation in Problem 6.1, so that 6.3 Apply the method of Problem 6.1 to the equation ¨x +x = εx3+ε2αx5 with x(ε, 0) = 1,˙ x(ε, 0) = 0. Obtain the period to order ε3, and confirm that the period is correct for the pendulum when the right-hand side is the first two terms in the expansion of x − sin x. (Compare the result of Problem 1.33. To obtain the required equations simply add the appropriate term to the right-hand side of the equation for x2 in Example 6.1 in NODE.)
Liapunov methods for determining stability of the zero solution
Authors: Jordan D W , Smith P
Published: November 2023

10.1. In each case the origin is an equilibrium point of the autonomous system. where A, B and C (all different) are the principal moments of inertia, and (ω1, ω2, ω3) is the spin of the body in principal axes fixed in the body. Find all the states of steady spin of the body. is a Liapunov function for the case when A is the largest moment of inertia, so that this state is stable. Suggest a Liapunov function which will establish the stability of the case in which A is the smallest moment of inertia. Are these states asymptotically stable? Why would you expect V as given above to be a first integral of the Euler equations? Show that each of the terms in braces is such an integral Since ˙ V =0, then the level curves of V coincide with the solutions of the Euler equations. One conclusion is that the equilibrium states are not asymptotically stable. The second conclusion is that V must be composed of first integrals of the Euler equations in some manner.
Bifurcations and manifolds
Authors: Jordan D W , Smith P
Published: November 2023

The solutions are real for λ 3 and λ 1, and complex for 3 < λ < 1. The graphs of Re(m1) and Re(m2) against λ are shown in Figure 12.1. Noting the signs of m1 and m2, we can observe that the equilibrium point at the origin is: A bifurcation occurs at the parametric value λ 1 where, as λ increases, the equilibrium point changes from a stable node to an unstable saddle point. A homoclinic path (NODE, Section 3.6) is a phase path which joins an equilibrium point to itself in an autonomous system. Show that ˙x = y, ˙y = x − x2 has such a path and find its equation. Sketch the phase paths for the perturbed system ˙x = y+λx, ˙y = x−x2, for both λ > 0 and λ < 0. (The homoclinic saddle connection is destroyed by the perturbation; the system undergoes what is known as a homoclinic bifurcation (Section 3.6) at λ = 0.)
Geometric Mechanics and Symmetry
Authors: Holm Darryl D , Schmah Tanya , Stoica Cristina , Ellis David C P
Published: November 2023

Classical mechanics, one of the oldest branches of science, has undergone a long evolution, developing hand in hand with many areas of mathematics, including calculus, differential geometry, and the theory of Lie groups and Lie algebras. The modern formulations of Lagrangian and Hamiltonian mechanics, in the coordinate-free language of differential geometry, are elegant and general. They provide a unifying framework for many seemingly disparate physical systems, such as n-particle systems, rigid bodies, fluids and other continua, and electromagnetic and quantum systems. Geometric Mechanics and Symmetry is a friendly and fast-paced introduction to the geometric approach to classical mechanics, suitable for a one- or two- semester course for beginning graduate students or advanced undergraduates. It fills a gap between traditional classical mechanics texts and advanced modern mathematical treatments of the subject. After a summary of the necessary elements of calculus on smooth manifolds and basic Lie group theory, the main body of the text considers how symmetry reduction of Hamilton's principle allows one to derive and analyze the Euler-Poincaré equations for dynamics on Lie groups. Additional topics deal with rigid and pseudo-rigid bodies, the heavy top, shallow water waves, geophysical fluid dynamics and computational anatomy. The text ends with a discussion of the semidirect-product Euler-Poincaré reduction theorem for ideal fluid dynamics. A variety of examples and figures illustrate the material, while the many exercises, both solved and unsolved, make the book a valuable class text.
Bayesian Nonparametric Latent Feature Models
Authors: Ghahramani Zoubin , Griffiths Thomas L , Sollich Peter
Published: November 2023

We describe a flexible nonparametric approach to latent variable modelling in which the number of latent variables is unbounded. This approach is based on a probability distribution over equivalence classes of binary matrices with a finite number of rows, corresponding to the data points, and an unbounded number of columns, corresponding to the latent variables. Each data point can be associated with a subset of the possible latent variables, which we refer to as the latent features of that data point. The binary variables in the matrix indicate which latent feature is possessed by which data point, and there is a potentially infinite array of features. We derive the distribution over unbounded binary matrices by taking the limit of a distribution over N × K binary matrices as K → ∞ . We define a simple generative processes for this distribution which we call the Indian buffet process (IBP; Griffiths and Ghahramani, 2005, 2006) by analogy to the Chinese restaurant process (Aldous, 1985; Pitman, 2002). The IBP has a single hyperparameter which controls both the number of feature per object and the total number of features. We describe a two-parameter generalization of the IBP which has additional flexibility, independently controlling the number of features per object and the total number of features in the matrix. The use of this distribution as a prior in an infinite latent feature model is illustrated, and Markov chain Monte Carlo algorithms for inference are described.
Detecting Selection in DNA Sequences: Bayesian Modelling and Inference
Authors: Merl Daniel , Prado Raquel
Published: November 2023

Recent developments in Bayesian modelling of DNA sequence data for detecting natural selection at the amino acid level are presented. This article summarizes and discusses empirical model-based approaches. Key features of the modelling framework include the incorporation of biologically meaningful information via structured priors, posterior detection of sites under selection, and model validation via posterior predictive checks and/or estimation of gene and species trees. In addition, model selection is handled using a minimum posterior predictive loss criterion. The models presented here can incorporate relevant covariates such as amino acid properties, extending in this way previous approaches. Applications include the analysis of two DNA sequence alignments with different characteristics in terms of evolutionary divergences among the sequences: an abalone sperm lysin alignment with a strong underlying phylogenetic structure and a low divergence sequence alignment encoding the Apical Membrane Antigen-1 (AMA-1) in the P. falciparum human malaria parasite.
Comparing Normal Means: New Methods for an Old Problem*
Authors: Bernardo José M , Pérez Sergio
Published: November 2023

Comparing the means of two normal populations is a very old problem in mathematical statistics, but there is still no consensus about its most appropriate solution. In this paper we treat the problem of comparing two normal means as a Bayesian decision problem with only two alternatives: either to accept the hypothesis that the two means are equal, or to conclude that the observed data are, under the assumed model, incompatible with that hypothesis. The combined use of an information-theory based loss function, the intrinsic discrepancy (Bernardo and Rueda, 2002), and an objective prior function, the reference prior (Bernardo, 1979; Berger and Bernardo, 1992), produces a new solution to this old problem which, for the first time, has the invariance properties one should presumably require.
The Einstein-scalar field system
Authors: Rendall Alan D
Published: November 2023

The field theoretic matter model for which the most mathematical results are known for the Einstein-matter system is a massless linear scalar field solving the wave equation. The available results on this subject are surveyed in this chapter. This section is concerned with spherically symmetric solutions of the Einstein equations with vanishing cosmological constant coupled to a scalar field. This is the subject of a series of papers by Christodoulou whose motivation was to find a model for gravitational collapse which was as simple as possible.
Background Material
Authors: Joyce Dominic D
Published: November 2023

In this chapter we explain some background necessary for understanding the rest of the book. We shall assume that the reader is already familiar with the basic ideas of differential and Riemannian geometry (in particular, manifolds and submanifolds, tensors, and Riemannian metrics) and of algebraic topology (in particular, fundamental group, homology and cohomology). We start in 1.1 with a short introduction to exterior forms on manifolds, de Rham cohomology, and Hodge theory. These will be essential tools later in the book, and we discuss them out of completeness, and to fix notation.
Mirror Symmetry And The Syz Conjecture
Authors: Joyce Dominic D
Published: November 2023

Readers are warned that this is the most flawed and unsatisfactory chapter in the book, due partly to the incompetence of the author, and partly to the nature of the subject. String theory is a huge endeavour, and difficult for mathematicians to penetrate. Mirror symmetry is not a clean mathematical statement, but a swamp of complicated, continuously evolving conjectures, which are slowly being turned into theorems. Each field would take a book far longer than this to explain properly, such as Hori et al. [166] on mirror symmetry.
Hyperkähler And Quaternionic Kähler Manifolds
Authors: Joyce Dominic D
Published: November 2023

We begin in 10.1 with an introduction to hyperKähler geometry. Sections 10.2 and 10.3 describe examples of noncompact hyperKähler 4-manifolds, hyperKähler ALE spaces, and compact hyperKähler 4-manifolds, K3 surfaces. These are very well understood, by treating them as complex surfaces and using complex algebraic geometry, and we give a very precise description of the moduli space of hyperKähler structures on K3. Then 10.4 explains the theory of compact hyperKähler manifolds in higher dimensions. In comparison to Calabi–Yau manifolds, rather few examples are known.
The Need for Enlargement and Differences from Previous Accessions
Authors: Landaburu Eneko
Published: November 2023

The EU enlargement from fifteen to twenty-five members on 1 May 2004 is an unprecedented event due to its scope and its historical and symbolic impact.
From Helsinki to Seville, July 1999–June 2002
Authors: Christoffersen Poul Skytte
Published: November 2023

The year 1999 was important for the enlargement process in many respects: the financial framework for enlargement was agreed in Berlin in the early spring and the Union decided to tackle, as the next step, the institutional questions linked to enlargement.
Financing the Enlargement
Authors: Vassiliou George , Christoffersen Poul Skytte
Published: November 2023

Many generations of Europeans were dreaming to unite Europe; a dream that could not be realized as long as Europe was divided in two opposing blocs. In 1989 and 1990 the forceful division ended but huge social and economic differences remained between the ex-Warsaw Pact country members and the EU. Thus, the EU’s first task was to help the Central and Eastern European countries to overcome the neglect of many decades and promote the reform of their economies and civil society.
The Public’s Attitude to Enlargement
Authors: Vassiliou George
Published: November 2023

Generally speaking the prospect of EU enlargement from fifteen to twenty-five members was accepted by the EU public both in the fifteen member countries and the candidates as a fact. The issue did not create any great animosity but neither enthusiasm. From the moment the so-called Iron Curtain collapsed it was accepted as a sine que non that the EU would be enlarged. This feeling was strengthened with the incorporation of East Germany in the Federal Republic. From there on it was a matter of time as to when the various Central and Eastern European countries, in addition to Cyprus and Malta, would be invited to join. It is characteristic in this respect that during the whole period of the negotiations the media gave limited attention to the issues of enlargement while they pointed out various other issues with which the fifteen dealt at their summits.
Eradication of invasive species: progress and emerging issues in the 21st century
Authors: Parkes John P , Panetta F Dane
Published: November 2023

At an international conference on the eradication of invasive species, held in 2001, Simberloff (2002) noted some past successes in eradication—from the global eradication of smallpox (Fenner et al. 1988) to the many successful eradications of populations (mostly mammals) from small islands (e.g. Veitch and Bell 1990; Burbidge and Morris 2002). However, he cautioned that we needed to be more ambitious and aim higher if we are to prevent and reverse the growing threat of the homogenization of global biodiversity
Biological control of invasive species
Authors: Murphy Sean T , Evans Harry C
Published: November 2023

Concerns about the impact of invasive species on biodiversity have raised the profile of invasive species to that of an agent of major global threat and change. Thus the discussion on how to prevent and manage invasive species is no longer just an agricultural one. Biological control through the use of host-specific natural enemies, which has essentially been developed and moulded by the agricultural sector for over 100 years, has been seen by many in recent times as a potentially effective and environmentally benign tool, suitable for use against invasive species in natural ecosystems.
The space around us
Authors: Rizzolatti Giacomo , Sinigaglia Corrado , Anderson Frances
Published: November 2023

In the preceding Chapter, our analysis focussed on the cortical mechanisms which come into play when we grasp our cup of coffee. However, to actually grasp the cup, we have to reach it and to do this, we have to locate it. In other words, we have to assess its distance from those parts of our body which will be involved in the movement—in the case of our coffee cup, the arm. The act of directing the arm towards the cup requires the brain to undertake a series of processes ranging from coding the spatial relations between the limb and the cup to the transformation of this information into the appropriate motor commands.
One-Way Systems
Authors: Higgins Peter M
Published: November 2023

All networks we have looked at hitherto have represented mutual relationships such as friendship or a two-way physical connection. However one-way systems are common. And not only in road and other transport networks: in physical and physiological systems involving valves, such as radios and the workings of the heart, we see traffic flowing in one direction only.

These directed networks are pictured in much the same way as two-way ones but now the edges carry arrows indicating the direction of the relationship between the two nodes. One-way networks like this are known in the trade as digraphs. This term is short for directed graph because a general network is often called a graph in the world of mathematics. Although we have stuck with the word ‘network’ throughout, we will, out of convenience, use the word digraph for these one-way networks.
Protecting Privacy in Europe: Administrative Feedbacks and Regional Politics
Authors: ∗ Abraham Newman
Published: November 2023

Advanced industrial societies are awash in personal information. Bank records, credit card transactions, web clicks, mobile phone logs, fingerprints, and now even retina scans leave detailed trails of personal behavior. Governments and businesses use this information to increase efficiency, segment markets, and differentiate risk. At the same time, however, the proliferation of this data raises the specter that personal information will be used to discriminate against individuals and to support Orwellian state surveillance (Newman and Zysman 2006). Societies have responded differently to the privacy challenges raised, relying on quite different public policy solutions.
The Politics of Competition and Institutional Change in European Union: The First Fifty Years
Authors: Büthe Tim
Published: November 2023

Competition causes suppliers of goods and services to lower prices, raise quality, and innovate. It is crucial for maximizing social welfare in a market economy. Ironically, however, the market by itself does not guarantee competition, unless one makes heroic assumptions about the costlessness of market entry (North 1981; Neumann 2001: 5ff.). As Adam Smith famously warned, ‘people of the same trade seldom meet together ... but the conversation ends in a conspiracy against the public, or in some contrivance to raise prices’. Yet it is not just monopolies, cartels, and mergers that can inhibit competition. Government subsidies and special privileges may also distort the market—within a country and even abroad through trade. Competition thus is an inherently political issue, as well as an economic one.
Disciplinary challenges
Authors: Davis Mark A
Published: November 2023

In terms of the number of research papers published, the field of invasion biology has been experiencing exponential growth during the past several decades (see Fig. 1.1). It is difficult for any human enterprise, whether an organization, a discipline, a country, or a business, to grow very rapidly in a short time without experiencing some growing pains.
Numerical Methods
Authors: Xiong Jie
Published: November 2023

Explicit solutions to the filtering equations are rarely available. Thus, to solve the filtering problems, we have to resort to numerical approximations. In this chapter, we study the numerical solutions to the optimal filters using certain particle systems. The main idea is to represent the solution to a stochastic partial differential equation through a system of weighted particles whose locations and weights are governed by stochastic differential equations that can be solved numerically. In Section 8.1, we consider a direct Monte-Carlo method based on the weighted particle-system representation.
Introduction: Research Agendas and Strategies in the Study of Latin American Politics
Authors: Munck Gerardo L
Published: November 2023

Research on Latin American politics over the past four decades has made many important contributions to comparative politics, the field of political science dedicated to the generation of knowledge about politics around the world. This research has played a critical role in expanding the scope of comparative politics from its pre-World War II focus on the United States and large Western European countries. Indeed, the first attempts to generate theories about politics in ‘developing’ countries based on a close knowledge of such countries were due to work on Latin America. And the first systematic empirical studies of politics in developing countries were analyses of Latin American cases. Moreover, the study of Latin America, probably more so than any other major region of the world, has drawn on and spurred a cross-fertilization of ideas from various regions, linking thinking about ‘developed’ and developing countries and also about developing countries from different regions. In short, research on Latin American politics has been a key site for generating and testing theories about politics and, hence, a vital part of comparative politics.
The Study of Politics and Democracy: Touchstones of a Research Agenda
Authors: Munck Gerardo L
Published: November 2023

Latin American politics experienced a far-reaching process of democratization during the 1980s and 1990s. Dictators in South America were replaced by elected leaders starting in 1978 and, with the displacements of General Stroessner in Paraguay in 1989 and General Pinochet in Chile in 1990, a long and dark period of authoritarian and military rule in South America drew to a close. In Central America, democratization was initiated with the holding of elections in the early 1980s, and the process continued with the resolution of armed conflicts through the signing of peace accords, and the transformation of guerrilla organizations into political parties, during the late 1980s until the mid-1990s.
Predictive statistics 101
Authors: Anderson Raymond
Published: November 2023

Unfortunately for Mark Twain, statistics have become a driving force behind modern economics and business, even if many people share his views. Nonetheless, some understanding is required, even if it might bore some people to tears. What follows is a fairly comprehensive overview of topics to which entire textbooks are dedicated. The focus is on providing the non-statistician some understanding of the terms that are used. As a result, it is of a very high level, and looks at:
Data preparation
Authors: Anderson Raymond
Published: November 2023

This module’s focus has been on data and, so far, data considerations, data sources, scoring structure, and information sharing have been covered. This chapter covers data preparation, the first practical stage in the scorecard development process. It is a crucial stage, as any mistakes can have a severe impact upon the results and may be impossible––or very expensive––to redress. It is covered under the headings of:
Transformation
Authors: Anderson Raymond
Published: November 2023

When first presented with a dataset, many budding statisticians think that they are able to use the data directly, but this is unfortunately not the case. The first step is to analyse the data, and transform it into something usable. The following section on data transformation is covered under the headings of:
Reject inference
Authors: Anderson Raymond
Published: November 2023

When dealing with selection processes, statisticians are faced with a predicament. If scorecards are developed using historical performance, how can rejects with no performance be assessed? The problem is best, and often, illustrated by applicants with derogatory information on file, which violates policy reject rules, such as court judgments recorded on the credit bureaux. Some cases still make it past the gatekeeper, either because there is extra information not captured by the score, or the applicants try harder, because they have better knowledge of their own circumstances. Lenders can ‘cherry pick’, such that they get the best of the lot from the reject region.

Thus, some means of making educated guesses is required; of using available information to infer reject performance, for use in the final model. It is the next step after segmentation, and is applied to each of the resulting segments. This was one of the biggest puzzles in application scoring in the 1960s. Early developments were limited to known performance, but there was a perception that they were deficient in the cut-off region, where they were needed most. The best approach was random supplementation in that region, and it took several years to come up with some rudimentary solutions (Lewis 1992).
Validation
Authors: Anderson Raymond
Published: November 2023

It is important that we not let models make the decisions, that we keep in mind that they are just tools, because in many cases it is management experience—aided by models to be sure—that helps to limit losses.

Susan Schmidt Bies, Federal Reserve Governor; in Geneva, 7 December 2004.

This is now the home stretch, but some work still needs to be done regarding validation, and presentation of the scorecard for sign-off, which are not mutually exclusive. Best practice is independent scorecard validation, whether by a specialist team, internal audit, or external consultants, but developers must use many of the same frameworks to ensure business acceptance of the model, and to facilitate subsequent review. The primary issues are to ensure: (i) that the model meets business needs; (ii) regulatory compliance; and (iii) when errors are identified, the new knowledge can be used to improve the process. The first is most critical, as the costs of model risk and the resultant adverse selection can break the bank—literally. Management must make informed decisions, and if there is any cause for concern, it must be made known. Much of the model risk results from the use of theoretical and statistical tools by inexperienced modellers, and policies should be implemented to formalise the ‘who’ and ‘how’ of the validation process, which may vary in different circumstances. It is not solely a mathematical exercise, as judgment also plays a role. The major issues are:
Account management
Authors: Anderson Raymond
Published: November 2023

Once customers have taken up the product, lenders enter the realm of ‘account management’, which takes on different meanings depending upon the context in which it is used. In its truest sense, it covers all front- and back-office functions used to manage existing account relationships, including billing, payment processing, limit management, renewals, collections, recoveries, tracing, etc. Within the credit risk management cycle (CRMC) however, it refers more specifically to the management of non-delinquent accounts—collections and fraud excluded. The goals are to manage individuals’ appetites for credit, and to try to keep them coming back for more.
Fraud
Authors: Anderson Raymond
Published: November 2023

Credit evaluation is based on dealings with Joe Average, who even if financially challenged, is at least honest. Unfortunately, credit people and systems are ill-prepared for Joe Fraudster, who relies upon deception and trickery to part people from their loot. It has thus become best practice for lenders to have dedicated fraud teams within the business. Both credit and fraud are responsible for prevention and cure in their respective areas, but fraud has the added task of investigating suspects. The two areas could be likened to bobby-on-the-beat policing and detective work. Credit deals with losses resulting from bad decisions, domestic problems, unfore-seen circumstances, or perhaps even negligence—but the cases are relatively straightforward, and at least lenders stand a chance of getting the money back. In contrast, fraud deals with cases involving criminal intent that are difficult to identify, and where the funds are extremely difficult to recover—to the extent that it is best to write off fraud losses, once they are identified.
Regulatory concepts
Authors: Anderson Raymond
Published: November 2023

Corporate Governance is concerned with holding the balance between economic and social goals and between individual and communal goals. The corporate governance framework is there to encourage the efficient use of resources and equally to require accountability for the stewardship of those resources. The aim is to align as nearly as possible the interests of individuals, corporations and society.
Not a Chimp
Authors: Taylor Jeremy
Published: November 2023

Humans are primates, and our closest relatives are the other African apes - chimpanzees closest of all. With the mapping of the human genome, and that of the chimp, a direct comparison of the differences between the two, letter by letter along the billions of As, Gs, Cs, and Ts of the DNA code, has led to the widely vaunted claim that we differ from chimps by a mere 1.6% of our genetic code. A mere hair's breadth genetically! To a rather older tradition of anthropomorphizing chimps, trying to get them to speak, dressing them up for 'tea parties', was added the stamp of genetic confirmation. It also began an international race to find that handful of genes that make up the difference - the genes that make us uniquely human. But what does that 1.6% really mean? And should it really lead us to consider extending limited human rights to chimps, as some have suggested? Are we, after all, just chimps with a few genetic tweaks? Is our language and our technology just an extension of the grunts and ant-collecting sticks of chimps? In this book, Jeremy Taylor sketches the picture that is emerging from cutting edge research in genetics, animal behaviour, and other fields. The indications are that the so-called 1.6% is much larger and leads to profound differences between the two species. We shared a common ancestor with chimps some 6-7 million years ago, but we humans have been racing away ever since. One in ten of our genes, says Taylor, has undergone evolution in the past 40,000 years! Some of the changes that happened since we split from chimpanzees are to genes that control the way whole orchestras of other genes are switched on and off, and where. Taylor shows, using studies of certain genes now associated with speech and with brain development and activity, that the story looks to be much more complicated than we first thought. This rapidly changing and exciting field has recently discovered a host of genetic mechanisms that make us different from other apes. As Taylor points out, for too long we have let our sentimentality for chimps get in the way of our understanding. Chimps use tools, but so do crows. Certainly chimps are our closest genetic relatives. But relatively small differences in genetic code can lead to profound differences in cognition and behaviour. Our abilities give us the responsibility to protect and preserve the natural world, including endangered primates. But for the purposes of human society and human concepts such as rights, let's not pretend that chimps are humans uneducated and undressed. We've changed a lot in those 12 million years.
More Is Better
Authors: Taylor Jeremy
Published: November 2023

So far we have discovered that the simplistic idea that point mutations which cause substitutions of DNA bases—the classical ‘mutation followed by selection’ mechanism of evolution—is an inadequate explanation of human evolution and human–chimp differences. Already we have added gene expression and the loss of function of genes as two important further mechanisms of evolutionary change.
Clever Corvids
Authors: Taylor Jeremy
Published: November 2023

In the last chapter we tried to find a way out of an impasse generated by the very narrow, blinkered approach to comparative cognitive psychology that has placed undue emphasis on comparisons between chimpanzees and humans. Outside this chimp–human comparative world are a breed of comparative cognitive psychologists who despair of this myopic bias and have proved their point with compelling psychological research on birds, a group of animals far removed from humans and the rest of the primates because they diverged over 280 million years ago. Chief among these scientists are the husband-and-wife duo from the University of Cambridge, Dr Nathan Emery and Professor Nicola Clayton.
Inside The Brain—The Devil is in the Detail
Authors: Taylor Jeremy
Published: November 2023

Imagine you are standing with both your arms held out in front of you and slightly to the side, palms upward—a little like a human version of the scales of justice that adorn the roof of the Old Bailey law courts in London. On your left palm sits a human brain—careful now, it is heavy: at over 1300 grams it weighs as much as a litre bottle of wine. On your right palm sits the brain of a chimpanzee. At just over 400 grams it is less than a third the weight. If an anatomist had placed a chimpanzee’s tongue on your palm, instead of its brain, it would have weighed more! Now think for a moment about their owners.
Is there a dysexecutive syndrome?
Authors: Stuss, Donald T , Alexander Michael P
Published: November 2023

The role of the frontal lobes has often been described as a ‘paradox’ or a ‘riddle’. Ascribed to this region has been the loftiest of functions (e.g. executive; seat of wisdom); others contested that the frontal lobes played no special role. There has also been controversy about the unity or diversity of functions related to the frontal lobes. Based on the analysis of the effects of lesions of the frontal lobes, we propose that there are discrete categories of functions within the frontal lobes, of which ‘executive’ functioning is one.
A tale of two exposures
Authors: Thomas Duncan C
Published: November 2023

Throughout history, mankind has experienced numerous and diverse environmental challenges. Some life-threatening problems have doubtless influenced the course of human evolution. Others, less severe, have nevertheless afflicted us with disease or affected us in other ways. Some are natural: climate, the micro-cosmos that surrounds us; others manmade: the myriad forms of pollution of the air, water, soil. Some are highly localized (toxic waste disposal sites), some regional (air pollution), some truly global in extent (climate change, depletion of the ozone layer). And new environmental problems are continually appearing, like fallout from nuclear weapons testing or novel chemicals produced by technological progress.
Spatial models
Authors: Thomas Duncan C
Published: November 2023

Spatial models—and geographic maps in particular—have always played a central role in the “person, place, and time” triad of descriptive epidemiology. Nowhere is this better illustrated than in the pioneering work of John Snow (1855) on cholera (Figure 9.1) that led to the identification of the Broad Street pump as the source of the epidemic and his removal of the pump handle as arguably the most famous public health intervention of all time.
Measurement error and exposure models
Authors: Thomas Duncan C
Published: November 2023

Exposure assessment is often one of the biggest challenges in environmental epidemiology. The topic is complex and very specific to the particular factors under study; entire books have been written on the general principles (Checkoway et al. 1989; Armstrong et al. 1992; Steenland and Savitz 1997; Nieuwenhuijsen 2003) as well as specialized texts in specific fields (e.g., Till and Meyer 1983 for exposures to radiation). Rather than discuss exposure assessment methodology in detail here, we briefly review the various general types of methods that are used, so as to motivate a treatment of the problem from a statistical point of view. Thus, this chapter will discuss approaches to exposure modeling, the influence of uncertainties in exposure estimates on exposure–response relations, and methods of correction for them.
Accommodating Historically Oppressed Social Groups: Deliberative Democracy and the Politics of Reconciliation
Authors: Bashir Bashir
Published: November 2023

The past forty years have witnessed a dramatic change in the way many Western democracies deal with issues of ethnocultural diversity. In the past, these democracies typically adopted majoritarian models of democracy and difference-blind models of national citizenship. In these traditional models, ethnocultural diversity was often seen as a threat to political stability, and hence as something that should be relegated to the private sphere and not publicly supported in the form of minority rights or multiculturalism. As a result, immigrants, national minorities, and indigenous peoples were all subject to a range of policies intended either to assimilate or marginalize them. Today, however, many Western democracies have abandoned these exclusionary models, and shifted to-wards a more accommodating approach to diversity. In short, we have witnessed a clear shift from ‘assimilationist’ models that suppress diversity to ‘accommodationist’ models that recognize diversity.
Introduction
Authors: Brown Dana L , Woods Ngaire
Published: November 2023

As companies ‘go global’, they are increasingly using factories and facilities spread across the world. But who regulates their activities in far-flung corners of the world economy? In many sectors such as textiles and apparel, chemicals, and forestry, the answer is that companies regulate their own behavior through codes and standards which they agree among themselves. These codes have attracted a lot of attention by scholars who have carefully described and attested to the growth of self-regulation, detailing the number and content of codes of self-regulation and standards which have been promulgated in various sectors.
Do Voluntary Standards Work Among Corporations? The Experience of the Chemicals Industry
Authors: Lenox Michael
Published: November 2023

In an attempt to avoid costly government regulation and other liabilities as a result of environmental externalities, a growing number of firms have promoted industry self-regulation—the association of firms to voluntarily control their collective behavior. In the past twenty years, environmental self-regulatory programs have proliferated in both the USA and abroad (Nash and Ehrenfeld 1996). Growing environmental regulations in industrialized nations and increasing environmental activism of consumers and the public in general have driven many industries to look for alternative strategies to deal with stakeholders. Industries have attempted to avoid costly government regulation and to placate concerned stakeholders by promising to voluntarily reduce their environmental impacts.
Local Politics and the Regulation of Global Water Suppliers in South Africa
Authors: Morgan Bronwen
Published: November 2023

This chapter explores the changing incentives faced by global water companies in light of the political and legal struggle in South Africa over the growing trend of supplying urban drinking water on a commercial, for-profit basis.1 The inclusion of a chapter on water service delivery in this book reflects a remarkable shift over the past ten to fifteen years in the salience of private corporations with a global reach in the water sector. The delivery of domestic water services has historically been determinedly local, markedly regulated, and typically embedded in the public sector.
Wallace and the Species Concept of the Early Darwinians
Authors: Mallet James
Published: November 2023

One of the extraordinary features of modern evolutionary biology is an inability to agree on a common definition of species. This lack of agreement, together with changes in the species concepts of taxonomists, is leading to an unprecedented level of taxonomic instability. In a sense, this is perhaps less of a problem than it at first appears, since almost everyone in the debate agrees that species evolve from populations within species, and that speciation is liable to be gradual: there will thus always be intermediate stages that are hard to classify. But in some cases, disagreements spill over into human affairs and cause practical problems. This is especially true in conservation (Isaac et al. 2004; Meiri and Mace 2007).