Showing papers by "University of Warwick published in 1994"

Partial Metric Topology

Abstract: Metric spaces are inevitably Hausdorff and so cannot, for example, be used to study non-Hausdorff topologies such as those required in the Tarskian approach to programming language semantics. This paper presents a symmetric generalised metric for such topologies, an approach which sheds new light on how metric tools such as Banach's Theorem can be extended to non-Hausdorff topologies.

A brief history of electronic noses

Abstract: The human nose is still the primaryinstrument' used to assess the smell or flavour of various industrial products today, despite considerable and sustained attempts to develop new electronic instrumentation capable of mimicking its remarkable ability In this paper we review the research effort that has been carried out over the past 25 years or so to create an electronic nose Indoing so, we first provide a definition for the term electronic nose, and then discuss some of the technologies that have been explored in what is essentially an intelligent chemical array sensor systemwe summarize the applications of electronic noses to date and suggest where future applications may lie

Cross-national Comparisons of the Variation in New Firm Formation Rates

Abstract: REYNOLDS P. D., STOREY D. J. and WESTHEAD P. (1994) Cross-national comparisons of the variation in new firm formation rates, Reg. Studies 28, 443–456. Births of new firms have been seen to be a major source of new employment creation in developed countries. In the European Community (EC), government policy for much of the 1980s focused upon encouraging the startup of new enterprises. This research examines birth rates of new firms by region in France, Germany (West), Italy, Ireland and the United Kingdom. Comparison is also made with similar studies which have been conducted in parallel for Sweden and the United States. The key findings of the study are twofold. First, the average new firm birth rates are roughly similar across countries and there are similar regional variations within all countries; the most fertile regions have annual new firm birth rates that are two to four times higher than the least fertile regions. Second, the underlying processes affecting new firm births at the regional level app...

Duality, Ambiguity and Flexibility: A Proceptual View of Simple Arithmetic

Abstract: In this paper we consider the duality between process and concept in mathematics, in particular using the same symbolism to represent both a process (such as the addition of two numbers 3+2) and the product of that process (the sum 3+2). The ambiguity of notation allows the successful thinker the flexibility in thought to move between the process to carry out a mathematical task and the concept to be mentally manipulated as part of a wider mental schema. We hypothesise that the successful mathematical thinker uses a mental structure which is an amalgam of process and concept which we call a procept. We give empirical evidence from simple arithmetic to show that this leads to a qualitatively different kind of mathematical thought between the more able and the less able, in which the less able are actually doing a more difficult form of mathematics, causing a divergence in performance between success and failure.

J-Holomorphic Curves and Quantum Cohomology

Abstract: Introduction Local behaviour Moduli spaces and transversality Compactness Compactification of moduli spaces Evaluation maps and transversality Gromov-Witten invariants Quantum cohomology Novikov rings and Calabi-Yau manifolds Floer homology Gluing Elliptic regularity Bibliography Indexes.

Ricin: structure, mode of action, and some current applications.

Abstract: Ricin is an abundant protein component of Ricinus communis seeds (castor beans) that is exquisitely toxic to mammalian cells. It consists of an enzymic polypeptide that catalyzes the N-glycosidic cleavage of a specific adenine residue from 28S ribosomal RNA, joined by a single disulfide bond to a galactose (cell)-binding lectin. The enzymatic activity renders ribosomes containing depurinated 28S RNA incapable of protein synthesis. The bipartite molecular structure of ricin allows it to bind to the mammalian cell surface, enter via endocytic uptake, and deliver the catalytically active polypeptide into the cell cytosol where it irreversibly inhibits protein synthesis causing cell death. Because of its cytotoxic potency, modified ricin is being used for the selective killing of unwanted cells and for the toxigenic ablation of cell lineages in transgenic organisms.

The Importance‐Performance Matrix as a Determinant of Improvement Priority

Abstract: A crucial stage in the formulation of operations strategy is the derivation of a ranked (or rated) list of competitive factors such as quality, flexibility, cost. This list is used either to infer an appropriate set of strategic operations decisions or alternatively it is used in conjunction with an independently derived list of the organization′s performance to prioritize each of the competitive factors. Martilla and James take the latter approach to derive an importance‐performance matrix. Examines how the matrix can be modified to reflect managers′ perceived relationships between “importance”, “performance” and “priority for improvement”. Reports two investigations, one dealing with operations improvement at the level of the whole operations function, the other at the level of the department or micro‐operation. Proposes a different zoning of the importance‐performance matrix from that used by Martilla and James.

Foreign direct investment and the risk of expropriation

Abstract: When an investor, for example a transnational corporation, invests abroad it runs the risk that its investment will be expropriated for the simple reason that international contracts are practically impossible to enforce. Any agreements or contracts then undertaken by the transnational company and the host country must be designed to be self-enforcing. It could be possible for the host country and the transnational corporation to find such self-enforcing agreements if there are future gains from trade. Thus although the host country might have a short-term incentive to expropriate, it has a long-term incentive to foster good relations with potential investors to attract more investment in the future. This conflict between short-term and long-term incentives determines the type of investment contracts agreed. This paper extends previous work on the general underprovision of investment when contracts are incomplete or only partially enforceable (see e.g. Grout (1984)) to a dynamic context. It is likewise shown that investment is initially underprovided but it increases over time and for certain parameter values it tends to the efficient level. The expected future discounted returns to the transnational company decline over time, extending Vernon's observation of the obsolescing bargain (Vernon (1971)). The model is also extended to allow for capital accumulation and consideration is given to renegotiation-proof contracts.

Face Perception in Children with Autism and Asperger's Syndrome

Abstract: Children with diagnoses of either autism or Asperger's syndrome were matched on measures of verbal mental age with nonautistic control children. They were tested on their abilities to process both facial and nonfacial stimuli. There were no significant differences between the low ability autistic and control groups, but the high ability autistic and Asperger's children performed significantly worse than controls across all tests. Group averages masked substantial individual variation. The results are seen as indicating a general perceptual deficit that is not specific to faces or emotions. This appears to be a common correlate of autism and Asperger's syndrome, rather than a core symptom.

Technology Diffusion and Public Policy

Abstract: A useful typology of technological change is provided by the Schumpeterian trilogy: invention (the generation of new ideas), innovation (the development of those ideas through to the first marketing or use of a technology) and diffusion (the spread of new technology across its potential market). Until recently, policy schemes in most OECD countries have tended to focus predominantly on the invention and innovation, or science and R&D, end of this technology spectrum (see e.g. Limpens et al., I 992). Although it is generally realised that it is the process of diffusion, or use of technology that creates productive potential and competitiveness, policy initiatives have largely bypassed opportunities to improve the diffusion process. If this may seem misplaced emphasis, it does in fact reflect the state of the academic literature which is wide ranging and extensive as it relates to policies on R&D, but small and fragmented as regards policies on diffusion. Currently a gradual reorientation of policy direction toward diffusion seems to be taking place. The US and UK governments, for example, have recently proposed major technology policy initiatives that, despite differences in emphasis, both stress the importance of creating an infrastructure conducive to a rapid spread of awareness and knowledge of innovations. We argue that, although sensible in themselves, such policies may be too limited in scope and that a broader policy stance may be needed. This paper has two main objectives. The first is to provide an overview of why policy intervention in the diffusion process may be desirable and what form it might take. This discussion is rather long, since to the best of our knowledge there is no published systematic synthesis of the diffusion policy literature (though see Stoneman (I987) for an earlier attempt). The second aim is to look at actual diffusion policies and their impacts. To make the task manageable we are restricting this paper to a discussion of the diffusion of new process technologies. Although similar issues apply to new consumer technologies these are not explicitly addressed. We also consider diffusion policy only within the context of a given institutional and macroeconomic environment. Although it may well be that the supply of skilled manpower, the nature of the capital market, animal spirits and entrepreneurship, fiscal and monetary policies will all impact upon the diffusion path, improvements in these areas will also impact upon a whole host of other aspects of the economy's performance. To use a plea for diffusion policy as a rationale for changes in such areas would be equivalent to the tail wagging the dog, and thus they fall outside the remit of this paper.

Modernism, Postmodernism and Organizational Analysis 4: The Contribution of Jürgen Habermas

Abstract: This article is the fourth in a series published by this journal on the relevance to organization studies of the postmodernism-modernism debate. It begins with a brief preface in which some recent developments in the field are placed in context and then goes on to analyze the work of Jurgen Habermas. As a 'critical modern ist' his ideas have a saliency for all those interested in defending organization theory from the charge that our discipline offers no means of preventing our involvement in the next Holocaust. If Habermas is the 'last modernist' then it may be that he represents one last chance for the discipline ... as we currently understand it.

Extensive sequence variation in the attachment (g) protein gene of avian pneumovirus : evidence for two distinct subgroups

Abstract: The putative attachment protein of the avian pneumovirus that causes turkey rhinotracheitis is, by analogy with mammalian pneumoviruses, expected to be the major antigenic determinant. We report the nucleotide sequence of the attachment (G) protein genes of five different continental European isolates and compare them with the previously published sequence of the G gene for the focal variant of a U.K. isolate. The nucleotide sequences and the predicted amino acid sequences indicate that there are at least two distinct subgroups, similar to the grouping described for human respiratory syncytial (RS) virus. The U.K. and French isolates form one group and the isolates from Spain, Italy and Hungary form a second. The two subgroups can be easily distinguished on the basis of restriction enzyme digestion of PCR-generated products representing the full-length gene. Within the subgroups the predicted G proteins were highly conserved (98.5 to 99.7% amino acid identity) compared to the levels of identity of RS virus G proteins in the same subgroup (80 to 95%). Between the avian pneumovirus subgroups described here there was an unexpected degree of divergence, the average amino acid identity between members of the two groups being only 38%. This compares with the 53% conservation seen between members of the RS virus subgroups A and B. Comparison of the predicted amino acid sequences showed that the G proteins of members of the two avian pneumovirus subgroups had similar structural features. All proteins had an amino-terminal membrane anchor and the positions of cysteine residues were highly conserved. The potential importance of the high level of variation between the two subgroups in terms of epidemiology of the disease is discussed.

Neural Networks, Decision Tree Induction and Discriminant Analysis: an Empirical Comparison

Abstract: This paper presents an empirical comparison of three classification methods: neural networks, decision tree induction and linear discriminant analysis. The comparison is based on seven datasets with different characteristics, four being real, and three artificially created. Analysis of variance was used to detect any significant differences between the performance of the methods. There is also some discussion of the problems involved with using neural networks and, in particular, on overfitting of the training data. A comparison between two methods to prevent overfitting is presented: finding the most appropriate network size, and the use of an independent validation set to determine when to stop training the network.

Innovation and export volumes and prices—a disaggregated study

Abstract: Competitiveness, trade performance, and employment DESPITE improvements in British economic performance in the mid-1980s the economy has subsequently experienced a recession of exceptional severity. During the later years of the boom the trade balance deteriorated sharply and in the subsequent slump the current account of the balance of payments has remained firmly in deficit. This poor trade performance reflects a continuation of long-run trends, which have often been attributed to a lack of 'non-price' competitiveness, deriving from insufficient innovation in the UK.

Dynamics and Evolution: Evolutionarily Stable Attractors, Invasion Exponents and Phenotype Dynamics

Abstract: We extend the ideas of evolutionary dynamics and stability to a very broad class of biological and other dynamical systems. We simultaneously develop the general mathematical theory and a discussion of some illustrative examples. After developing an appropriate formulation for the dynamics, we define the notion of an evolutionary stable attractor (ESA) and give some samples of ESAS with simple and complex dynamics. We discuss the relationship between our theory and that for ESSS in classical linear evolutionary game theory by considering some dynamical extensions. We then introduce and develop our main mathematical tool, the invasion exponent. This allows analytical and numerical analysis of relatively complex situations, such as the coevolution of multiple species with chaotic population dynamics. Using this, we introduce the notion of differential selective pressure which for generic systems is nonlinear and characterizes internal ESAS. We use this to analytically determine the ESAS in our previous examples. Then we introduce the phenotype dynamics which describe how a population with a distribution of phenotypes changes in time with or without mutations. We discuss the relation between the asymptotic states of this and the ESAS. Finally, we use our mathematical formulation to analyse a non-reproductive form of evolution in which various learning rules compete and evolve. We give a very tentative economic application which has interesting ESAS and phenotype dynamics.

Stop and chop phacoemulsification

Abstract: We present a method for phacoemulsification within the capsular bag in which sculpting is performed to provide space for nuclear manipulation and then the posterior plate is cracked into two halves. The nuclear rim is chopped into bite-size pieces for removal using a modified lens hook that is buried in the nuclear periphery and pulled toward the center. The procedure begins as a routine nuclear cracking technique and then stops. It continues as a chop technique.

Longest Common Subsequences

Abstract: The length of a longest common subsequence (LLCS) of two or more strings is a useful measure of their similarity. The LLCS of a pair of strings is related to the `edit distance'', or number of mutations/errors/editing steps required in passing from one string to the other. In this talk, we explore some of the combinatorial properties of the sub- and super-sequence relations, survey various algorithms for computing the LLCS, and introduce some results on the expected LLCS for pairs of random strings.

Strategic Planning and Financial Performance in UK SMEs: Does Formality Matter?

Abstract: SUMMARY The majority of the literature on corporate performance in SMEs has indicated that the absence of formal strategic planning (or inadequacies in its process) can be directly linked with failure, while its presence can be linked to success (Bracker and Pearson, 1986; Stoner, 1983). However, other empirical evidence fails to find a relationship (Robinson and Pearce, 1983). These differences are due to methodological and theoretical problems facing research in this domain. This paper attempts to improve on both issues. The hypothesis that ‘formal planning is not associated with better-than-average performance’ is tested on a sample of SMEs, controlled by sector, using a 5-year operating period. Five measures of financial performance are utilized, including both the arithmetic and geometric measurements of central tendency as appropriate. Moreover, perceptions of CEOs, rather than the aggregation of scale-based measurements of organizational variables, are used to prescribe the measure of formality used in the analysis.

The role of legal status in influencing bank financing and new firm growth

Abstract: This paper examines the characteristics of new firm founders who use loans and overdrafts from the clearing banks to finance initially their business. Bank lending to new firms appears unrelated to the personal characteristics of founders, but related to whether individuals provide personal savings and the legal status of the business. This contrasts with the factors which influence the growth of new firms. Here, the founder's age, employment status and birthplace are associated with larger firms. The only variable which appears to influence consistently both bank lending and the employment growth in firms is whether or not the business is a limited company.

What is Management? An Outline of a Metatheory

Abstract: SUMMARY Drawing on a realist ontology and epistemology, a metatheory of management is outlined in this paper as a way of (a) redescribing the nature of management, and (b) delineating the scope of application of various perspectives on management. Four perspectives are briefly reviewed, and the claim is put forward that each one of them deals with issues arising at a different ontological layer of management. Management is shown to consist of four layers with each one exhibiting its own characteristics and dynamics. Deeper theoretical descriptions penetrate deeper into the nature of management and capture new layers. The metatheoretical outline proposed here moves beyond the ‘either/or’ polarization that management literature has exhibited so far, namely conceiving management either as a collective institutional necessity or as a set of individual practices. Indeed, it is argued that management is both of these things plus a few more, and that an appreciation of its nature is possible within a realist ontology and epistemology.

Modern Techniques of Surface Science

Abstract: This book describes the physical basis and applications of all of the principal techniques, and most of the lesser techniques, used in surface science today. They are grouped according to the underlying physics and are described in eight chapters. The treatment of each technique is thorough, but an exhaustive survey characteristic of a scientific review is not attempted. The physics underlying each technique is described carefully, together with the kind of instrumentation used. The strengths and limitations of each technique are brought out through discussion of examples of applications and results, chosen mainly from studies of the physics and chemistry (including adsorption, crystallography and catalytic properties) of well-characterised surfaces.

New firm growth and bank financing

Abstract: This paper examines the extent to which Lucas' ideas on human capital and Jovanovic' theorising on “learning” can provide further insights into the development of small firms. It focuses exclusively upon newly established independent firms. Our evidence from two surveys is that bank lending to new firms is unrelated to many of the personal characteristics of founders which have been argued by other researchers to relate to small firm performance. Instead lending appears to be more related to whether or not the founder can or chooses to use personal savings, and the legal status of the business.

The Learning Organization: Adult Learning and Organizational Transformation

Abstract: SUMMARY The concept of the ‘learning organization’, with its roots in self-development and action-learning, has recently caught the imagination of many organizations and researchers. However, emerging definitions are creating ambiguity. There is, therefore, a need to add substance to them, and widen our understanding of what the concept means, by concentrating on what is meant by ‘learning’, and focusing on exactly how adults learn. Understanding and facilitating adult learning in organizations is, by and large, a confused activity that fails to connect with an individual's other experiences and needs, and with what modern psychology and research have to teach us. In particular, learning and skills need to be linked to the questioning of purpose and value in an organization.

Nonnormal del Pezzo Surfaces

Abstract: This paper studies reduced, connected, Gorenstein surfaces with ample-^", assumed to be reducible or nonnormal. The normalisation is a union of one or more standard surfaces (scrolls and Veronese surfaces), marked with a conic as double locus. The question is how to glue these together to get a Gorenstein scheme. In characteristic 0, the results amount to a classification of projective surfaces in the style of the 1880s. However, the methods involve a study of the dualising sheaf of a nonnormal variety in terms of Rosenlicht differentials, and there is a subtle pathology in characteristic p due to Mori and S. Goto.

Heat sink assembly for solid state devices

Abstract: A heat sink assembly (10) adapted for use with an electronic device package (24) such as a microprocessor having a grid array is shown having, in a first embodiment, a threaded base (34) of a finned heat sink (28) adapted to be received in a threaded bore (26) of an adaptor (12) which mounts onto the electronic device package (24). Desired thermal coupling is achieved by screwing down the heat sink (28) in biasing engagement with the package (24). Alternate embodiments show the heat sink (28) which has a snap on flange (20, 22) to attach the heat sink (28) to the adaptor (12) and the adaptor extending down to engage with the socket (60) in which the electronic device package (24) is installed.

Analysis of respiratory syncytial virus strain variation in successive epidemics in one city.

Abstract: The variability of respiratory syncytial virus isolates from five successive epidemics in an urban population was determined. A total of 187 isolates of respiratory syncytial virus from the southern part of Birmingham, United Kingdom, were classified into subgroups A and B and were then further assigned to genetic lineages. Allocation of isolates into lineages was achieved by reverse transcription of infected cell RNA and then PCR amplification of selected regions of the genome; PCR products were examined by restriction mapping or nucleotide sequencing of parts of the nucleoprotein gene, the small hydrophobic protein gene, and the attachment protein gene. Previous work has shown that estimations of genetic diversity by analysis of genes coding for proteins likely (attachment protein) and unlikely (nucleoprotein and small hydrophobic protein) to be under immune pressure gave concordant results. Six genetic lineages of subgroup A isolates have been defined by this procedure; these isolates differ by up to 20% in the amino acid sequences of their attachment proteins; likewise, subgroup B isolates can be divided into two categories by restriction mapping of parts of their nucleoprotein and attachment protein genes. The same genetic lineages appeared to be present worldwide during the same period. The analysis of isolates from successive epidemics showed that different lineages predominated in each epidemic and that not all lineages were present in every epidemic. Some lineages appeared to increase in numbers over several years and then decline, possibly indicating a buildup of resistance in the community to a particular genotype.