Spatial discretization of discrete dynamical systems

Investigates what can go wrong when dynamical systems are modelled with a computer. Number theoretic techniques were used to detail the effects "discretization" errors caused by computer round-off had on characteristics of a system. In particular, a relationship was established between the occurrence of long cycles in a system and the classical result known as Artin's conjecture. Algorithms were then developed which eliminated discretization errors.

The padding scheme for RSA signatures

The RSA scheme is used to sign messages; however, in order to avoid forgeries, a message can be padded with a fixed string of data P. De Jonge and Chaum showed in 1985 that forgeries can be constructed if the size of P (measured in bytes) is less than the size of N/3, where N is the RSA modulus. Girault and Misarsky then showed in 1997 that forgeries can be constructed if the size of P is less than the size of N/2. In 2001, Brier, Clavier, Coron and Naccache showed that forgeries can still be constructed when the size of P is less than two thirds the size of N. In this paper, we demonstrate that this padding scheme is always insecure; however, the complexity of actually finding a forgery is O(N). We then focus specifically on the next unsettled case, where P is less than 3/4 the size of N and show that finding a forgery is equivalent to solving a set of diophantine equations. While we are not able to solve these equations, this work may lead to a break-through by means of algebraic number theory techniques.

A constructivist framework for online collaborative learning:adult learning and collaborative learning theory

The purpose of this chapter is to review and discuss theoretical perspectives that help to frame collaborative learning online. The chapter investigates literature about the type of learning and behavior that are anticipated and researched among participants learning collaboratively and discusses how these attributes explain computer-supported collaborative learning. The literature about learning is influenced by perspectives from a number of fields, particularly philosophy, psychology, and sociology. This chapter describes some of these perspectives from the fields of cognitive psychology, adult learning, and collaborative group learning. Recent research into computer-supported collaborative learning that applies these theories will also be discussed.

Flow analysis based on a pulsed flow of solution: theory, instrumentation and applications

The increased demands placed on solution propulsion by programmed flow systems, such as sequential injection analysis, lab-on-value technology, bead injection and multi-commutation, has highlighted the inability of many conventional pumps to generate a smooth, consistent flow. A number of researchers have examined ways to overcome the inadvertent, uncontrolled pulsation caused by the mechanical action of peristaltic pumps. In contrast, we have developed instruments that exploit the characteristics of a reproducible pulsed flow of solution. In this paper, we discuss our instrumental approaches and some applications that have benefited from the use of a reproducible pulsed flow rather than the traditional linear flow approach. To place our approach in the context of the continuously developing field of flow analysis, an overview of other programmed flow systems is also presented.

Constructivism in environmental education: beyond conceptual change theory

Abstract constructivism, as a set of theories about how learners learn, has been an important discourse in the educational research literature for a number of years. Interestingly, it has been far more visible in science education research than in environmental education research. This article considers conceptual change theory within constructivism as a contested concept, outlines differing expressions of constructivism in science education and environmental education, and argues for approaches to environmental education that adopt socially constructivist perspectives with respect to the character of the subject matter content as well as to learners' apprehension of such content. In considering implications for research, this perspective is juxtaposed with a recent United States Education Act, which prescribes a far more objectivist approach to educational research and which serves as a reminder that research itself is a powerful factor in shaping how the nature of subject matter is constructed, learning and the implications of these for teaching practice.

A creative twist: management theory, creativity and the arts

For many theorists and practitioners in the area of organizational theory, HRM, marketing and other domains of organization studies, organizational creativity is something to be distilled and managed as an element of organizational performance. The article argues, however, that this process of appropriation from the creative arts is subject to a number of problematic transitions. The article's starting point is the notion of creativity itself. Within the creative arts, the question of what constitutes creativity and its relationship to artistic practice is subject to considerable debate. This debate centers on the question of whether creativity represents an essentialist and inexplicable (even spiritual) component of artistic practice or whether creativity is a trait of work and cannot be attributed as a unique aspect of art. The mantra of creativity provides nothing more than a means to control individuals and provide them with a false hope that contributing to the success of business will provide a means to self fulfillment.

Chaos theory and assessment of forest stakeholder attitudes towards Australian forest policy

The Regional Forest Agreement process has dominated Australian forest policy for the past decade. The RFA process set in place a mechanism by which benchmark conservation values were established for forest  ecosystems, whilst addressing the needs of the timber industry. The outcomes of a number of RFA's have been fraught with controversy. Key stakeholder groups have shown disagreement with processes and  outcomes of methods employed by government both in establishing conservation reserves and areas allocated to timber harvesting. This research uses non-linear techniques to examine the dynamical behavior in stakeholder responses and to identify patterns of behavior that may lead to prediction of stakeholder responses. The method developed in this research provides a bridge between social sciences and Chaos theory.¹

Shaming, shame and recidivism : a test of reintegrative shaming theory in the white-collar crime context

Despite the popularity of reintegrative shaming theory in the field of criminology, only a small number of studies purporting to test it have been published to date. The aim of the present study, therefore, is to provide an empirical test of Braithwaite's (1989; Braithwaite and Braithwaite 2001) theory of reintegrative shaming in the white-collar crime context. The data on which the study is based came from survey data collected from a group of 652 tax offenders. Consistent with predictions, it was found that feelings of reintegration/stigmatization experienced during an enforcement event were related to reoffending behaviour. Those taxpayers who felt that their enforcement experience had been reintegrative in nature were less likely to report having evaded their taxes two years later. Consistent with Braithwaite and Braithwaite's (2001) hypotheses, shame-related emotions were also found to partially mediate the effect of reintegration on subsequent offending behaviour. Implications for the effective regulation of white-collar offenders are discussed.

Postmodernist theory and its relationship to tourism research

This article highlights the theoretical notion of Postmodernism and attempts to place Tourism research into the postmodernism frame of reference. This is achieved by a brief description of the theory and further development in section two which reviews the challenges of postmodernism to research in the tourism field. There is then an endeavour to intertwine the constructs of postmodernist theory and to illustrate how it can relate to the tourism industry and in particular contemporary tourism. Indeed, we argue that even though a number of authors have begun to chart the sociological dimensions of post-modem tourism they have done so without highlighting the definitions and structure of postmodernist theory. Examples are given in order to support the theoretical approach to research which we suggest in this paper and every effort is undertaken in order to argue that postmodernist research in tourism can be beneficial and fruitful tor future directions. Consequently this article attempts to dispel some of the widespread bemusement concerning post-modem theories and post-modern tourism by reviewing some of the recent developments in the area and suggesting further research.

The welfare economics of measuring sustainability: a new approach based on social choice theory and systems analysis

This paper presents a new measure of sustainability within a welfare economics framework. Gross domestic product (GDP) can be used as an indicator of sustainability if the GDP estimates are undertaken within a cost-benefit analysis framework based on social choice perspectives. Sustainability is dependent on a healthy and functioning socio-economic and environmental (SEE) system. Economic development can damage the SEE system through resource degradation, over-harvesting and pollution. This paper addresses the tensions between economic development and sustainability by undertaking a number of SEE-based adjustments to GDP based on social choice perspectives in order to measure sustainability. These adjustments include the environmental and social costs caused by economic development such as water pollution, the depletion of non-renewable resources, and deforestation. Thailand is used as a case study for a 25 year period (1975-1999). The results show a divergence in terms of GDP per capita and the SEE-adjusted GDP per capita figure. The paper concludes that, with increasing environmental and social costs of economic development, pursuing such extreme high growth objectives without due environmental and social considerations can threaten present social welfare and future sustainability. Copyright © 2005 John Wiley & Sons, Ltd and ERP Environment.

Constructivism in environmental education beyond conceptual change theory

Constructivism, as a set of theories about how learners learn, has been an important discourse in the educational research literature for a number of years. Interestingly, it has been far more visible in science education research than in environmental education research. This article considers conceptual change theory within constructivism as a contested concept, outlines differing expressions of constructivism in science education and environmental education, and argues for approaches to environmental education that adopt socially constructivist perspectives with respect to the character of the subject matter content as well as to learners' apprehension of such content. In considering implications for research, this perspective is juxtaposed with a recent United States Education Act, which prescribes a far more objectivist approach to educational research and which serves as a reminder that research itself is a powerful factor in shaping how we construct the nature of subject matter, learning and the implications of these for teaching practice.

Using activity theory in researching young children's use of calculators

Constructivist and socio-cultural perspectives in mathematics education highlight the crucial role that activity plays in mathematical development and learning. Activity theory provides a socio-cultural lens to help analyse human behaviour, including that which occurs in classrooms. It provides a framework for co-ordinating constructivist and socio-cultural perspectives in mathematics learning. In this paper, we adopt Cole and Engeström's (1991) model of activity theory to examine the mediation offered by the calculator as a tool for creating and supporting learning processes of young children in the social environment of their classroom. By adopting this framework, data on young children's learning outcomes in number, when given free access to calculators, can be examined not only in terms of the mediating role of the calculator, but also within the broader context of the classroom community, the teachers' beliefs and intentions, and the classroom norms and the division of labour. Use of this model in a post hoc situation suggests that activity theory can play a significant role in the planning of future classroom research.

Environmental determinants of healthy eating : in need of theory and evidence

In order to promote healthful nutrition, insight is needed into the determinants of nutrition behaviours. Behavioural determinant research and behavioural nutrition interventions have focused mostly on individual-level motivational factors. It has been argued that the individual's socio-cultural and physical environments may be the main determinants of nutrition behaviours. However, the theoretical basis and empirical evidence for environmental determinants of nutrition behaviours are not strong. The present paper is a narrative review informed by a series of systematic reviews and recent original studies on associations between environmental factors and nutrition behaviours to provide an overview and discussion of the evidence for environmental correlates and predictors of nutrition behaviour. Although the number of studies on potential environmental determinants of nutrition behaviours has increased steeply over the last decades, they include only a few well-designed studies with validated measures and guided by sound theoretical frameworks. The preliminary evidence from the available systematic reviews indicates that socio-cultural environmental factors defining what is socially acceptable, desirable and appropriate to eat may be more important for healthful eating than physical environments that define the availability and accessibility of foods. It is concluded that there is a lack of well-designed studies on environmental determinants of healthful eating behaviours. Preliminary evidence indicates that social environmental factors may be more important than physical environmental factors for healthful eating. Better-designed studies are needed to further build evidence-based theory on environmental determinants to guide the development of interventions to promote healthful eating.

Small firm e-business adoption : a critical analysis of theory

Purpose – The paper critiques a range of theories and evaluates their ability to provide a lens for explaining the idiosyncratic nature of small firms and their e-business adoption decisions.

Design/methodology/approach – This literature review firstly summarises the existing research evidence that shows that small firms are idiosyncratic when it comes to e-business adoption. It then critiques theories commonly used in the literature in this field to examine the extent to which they take this small firm idiosyncrasy into account when explaining e-business adoption decisions.

Findings – The critical analysis shows that no commonly-used theory adequately explains small firm adoption of e-business because each omits important aspects of small firm idiosyncrasy. The analysis suggests that an integrated theoretical framework is needed. Preliminary ideas on this framework are provided.

Originality/value – Existing research generally applies a small number of selected theories and formulates research models of adoption factors. However, there is no systematic analysis of theories in this field and no consensus about theoretical frameworks. This paper addresses this limitation of the literature by critically evaluating the commonly used theories in terms of their individual suitability as lenses for explaining small firm e-business adoption.

Evidence for healthy cities : reflections on practice, method and theory

The European Healthy Cities project can be characterized as a social movement that employs an extremely wide range of political, social and behavioural interventions for the development and sustenance of urban population health. At all of these levels, the movement is inspired by ideological, theoretical and evidence-based perspectives. The result of this stance is a dynamic, complex and diverse landscape of initiatives, plans, programmes and actions. In quantitative terms (the number of WHO designated cities and associated cities and communities through national networks), ‘Healthy Cities’ can be regarded as an extraordinary accomplishment and a credit for both WHO and cities in the movement. In qualitative terms, however, critics of the movement have maintained that little evidence on its success and effectiveness has been generated. This critique finds its foundations in the mere perceptions of evidence, the politics of science and urban governance, and perspectives on the preferred or professed utilities of evidence-based health notions. The article reviews the nature of evidence and its interface with politics and governance. Applying a conceptual framework combining insights from knowledge utilization theory, theoretical perspectives on (health) policy development, theory-based evaluations and planned intervention approaches, it demonstrates that, although the evidence is overwhelming, there are barriers to the implementation of such evidence that should be further addressed by ‘Healthy Cities’.