The Statistics of Simulating Chaos

When simulating a dynamical system, the computation is actually of a spatially discretized system, because finite machine arithmetic replaces continuum state space. For chaotic dynamical systems, the discretized simulations often have collapsing effects, to a fixed point or to short cycles. Statistical properties of these phenomena can be modelled with random mappings with an absorbing centre. The model gives results which are very much in line with computational experiments. The effects are discussed with special reference to the family of mappings f (x)=1-|1-2x|,x [0,1],1,<,,<,. Computer experiments show close agreement with predictions of the model.     

Exposure to occupational violence and the buffering effects of intra-oranizational support

This paper presents a conceptually distinct analysis of the data first reported by Leather et al. Specifically, it investigates the effects of exposure to a variety of forms of work-related violence upon work attitudes and general well-being within a sample of UK public house licensees—individuals who manage public houses and hold the licence permitting the sale of alcoholic drinks on the premises. In addition, it examines the role of social support in moderating such effects. Based upon a sample of 242 licensees, it reports a consistent interaction between exposure to such violence and the availability of perceived intra-organizational support in determining the size of any negative effects upon individual well-being, job satisfaction and organizational commitment. It is argued that exposure to all forms of work-related violence, including intimidation, verbal abuse and threat, should be seen as a potential stressor within the work environment, the negative effects of which are buffered by perceived support from within the organization, but not by that perceived to be available from informal sources such as family and friends.     

Assembly Line Balancing Using Genetic Algorithms with Heuristic-Generated Initial Populations and Multiple Evaluation Criteria*

We use genetic algorithms (GA) to solve the assembly line balancing (ALB) problem. Inparticular, we show how this technique can be used to generate feasible line balances, improve upon solutions obtained by other heuristics reported in the literature, and utilizeany one or more evaluation criteria that can be expressed in functional form. The procedure is demonstrated with two examples: (1) intimating the improvement of heuristic-generated ALB solutions by including them in the GA initial population, and (2) the possibility of balancing assembly lines with multiple criteria and side constraints. These examples suggest that GA can be a powerful tool in ALB. To investigate the utility of GA on single-criterion problems, an experiment is conducted that compares both the GA approach and conventional heuristics. Results indicate that the GA solutions are significantly improved over the heuristic solutions under the conditions studied. It is also found that the presence of heuristic-generated conventional solutions in the GA initial population leads to statistically preferred results.     

Net migration and migration effectiveness: A comparison between Australia and the United Kingdom, 1976–96

This paper explores the impact of net migration in Australia and the United Kingdom using measures of migration effectiveness computed from period-age migration data for four consecutive five-year periods. Results reported in Part 1 of this paper (Stillwellet al. 2000) suggest that while the overall effectiveness of net migration at the scale of city regions has declined over the twenty-year period in both countries, important geographical variations are evident. Part 2 considers how patterns of migration effectiveness vary by age and presents a single classification of all the city regions on the basis of age-specific effectiveness. More detailed analysis includes spatial patterns for particular age groups and net migration profiles of selected regions. Cohort effects are shown to be important for explaining changes between time periods in these regions.     

A SIMULATION ANALYSIS OF THE JAPANESE JUST-IN-TIME TECHNIQUE (WITH KANBANS) FOR A MULTILINE,MULTISTAGE PRODUCTION SYSTEM

The Japanese “just-in-time with kanban” technique reduces in-process inventory to absolute minimal levels, in concert with the Japanese belief that inventory is an unnecessary evil. Due to the success of Japanese firms that employ this type of system, American firms would like to import this technique and emulate Japanese successes. But this Japanese success may be attributable not only to the just-in-time with kanban technique but also to the production environment in which the technique is employed. This paper simulates the just-in-time with kanban technique for a multiline, multistage production system in order to determine its adaptability to an American production environment that might include such characteristics as variable processing times, variable master production scheduling, and imbalances between production stages. The results have practical implications for those firms considering adoption of the Japanese technique.     

Total factor productivity and shareholder returns in banking

This paper examines shareholder value drivers in European banking focusing on the efficiency and productivity features of individual banks. In particular, we analyse the value relevance of bank cost efficiency and total factor productivity (TFP) (in all its components, including technological change, pure technical efficiency change and scale efficiency change) to see how these influence shareholder value creation in European banking. The paper focuses on the French, German, Italian and U.K. banking systems over the period 1995–2002 and includes both listed and non-listed banks. We find that TFP changes best explain variations in shareholder value (measured by market-adjusted returns, MAR, for listed banks and by the ratio of EVA_bkg to invested capital at time t−1 for non-listed banks). In both samples, we also find that technological change seems to be the most important component of TFP influencing shareholder value creation in European banking.     

Evaluating qualitative management research: Towards a contingent criteriology

The term qualitative management research embraces an array of non‐statistical research practices. Here it is argued that this diversity is an outcome of competing philosophical assumptions which produce distinctive research perspectives and legitimate the appropriation of different sets of evaluation criteria. Some confusion can arise when evaluation criteria constituted by particular philosophical conventions are universally applied to this heterogeneous management field. In order to avoid such misappropriation, this paper presents a first step towards a contingent criteriology located in a metatheoretical analysis of three modes of qualitative management research which are compared with the positivist mainstream to elaborate different forms of evaluation. It is argued that once armed with criteria that vary accordingly, evaluation can reflexively focus upon the extent to which any management research consistently embraces the particular methodological principles that are sanctioned by its a priori philosophical commitments.