Embedding expert systems in semi-formal domains : examining the boundaries of the knowledge base

This thesis examines the use of expert systems in semi-formal domains. The research identifies the main problems with semi-formal domains and proposes and evaluates a number of different solutions to them. The thesis considers the traditional approach to developing expert systems, which sees domains as being formal, and notes that it continuously faces problems that result from informal features of the problem domain. To circumvent these difficulties experience or other subjective qualities are often used but they are not supported by the traditional approach to design. The thesis examines the formal approach and compares it with a semiformal approach to designing expert systems which is heavily influenced by the socio-technical view of information systems. From this basis it examines a number of problems that limit the construction and use of knowledge bases in semi-formal domains. These limitations arise from the nature of the problem being tackled, in particular problems of natural language communication and tacit knowledge and also from the character of computer technology and the role it plays. The thesis explores the possible mismatch between a human user and the machine and models the various types of confusion that arise. The thesis describes a number of practical solutions to overcome the problems identified. These solutions are implemented in an expert system shell (PESYS), developed as part of the research. The resulting solutions, based on non-linear documents and other software tools that open up the reasoning of the system, support users of expert systems in examining the boundaries of the knowledge base to help them avoid and overcome any confusion that has arisen. In this way users are encouraged to use their own skills and experiences in conjunction with an expert system to successfully exploit this technology in semi-formal domains

The Political Economy of Quality Measurement: A Case Study of the U.S. Slaughter Cattle Market

As agricultural products move from being economic commodities to quality-differentiated goods, price dispersion within specific markets increases and implicit subsidies from high quality producers to low quality producers are removed. This paper examines how these distributional effects can influence patterns of support and opposition to changes in marketing arrangements. The simple model developed is calibrated using data from the U.S. slaughter cattle market. Estimates of the economic impact on producers of measuring quality more accurately are found to be similar in size to previous estimates of market power price suppression in the market.quality, captive supplies, cattle, asymmetric information

Leaving the labour market later in life. How does it impact on mechanisms for health?

Objectives: Negative associations between non-employment and health among older people are well established and are potentially important for successful ageing. However, opportunities to improve health through re-employment or extending working lives are limited as later-life exits from employment are often unwanted and permanent. We aim to establish a greater understanding of the psychosocial mechanisms underlying non-employment and health associations in older people to identify modifiable pathways through which the negative impact of non-employment can be ameliorated. Methods: Using multilevel analysis of four waves of repeated panel data from a representative sample of 1551 older men and women reaching state retirement age in the West of Scotland from 1987/1988 to 2000/2004, we explored respondents' strength of agreement with 20 statements relating to their self-defined employment status, covering themes of functioning, social engagement, self-esteem, mental engagement, stress, and control and autonomy. Results: Compared with those in employment, respondents who were retired, unemployed, sick/disabled and home makers were more likely to agree that this resulted in poor social engagement, low self-esteem and, with the possible exception of retirees, reduced mental engagement. Associations were particularly marked among unemployed and sick/disabled respondents who also agreed that their status was a source of worry and prevented them from feeling in control. Conclusion: Older people who are not in employment are at higher risk of poor physical and mental health. Interventions targeting psychosocial mechanisms such as social and mental engagement and self-esteem offer potentially valuable opportunities to improve health outcomes and promote successful ageing

The impact of a natural time change on the convergence of the Crank-Nicolson scheme

We first analyse the effect of a square root transformation to the time variable on the convergence of the Crank-Nicolson scheme when applied to the solution of the heat equation with Dirac delta function initial conditions. In the original variables, the scheme is known to diverge as the time step is reduced with the ratio of the time step to space step held constant and the value of this ratio controls how fast the divergence occurs. After introducing the square root of time variable we prove that the numerical scheme for the transformed partial differential equation now always converges and that the ratio of the time step to space step controls the order of convergence, quadratic convergence being achieved for this ratio below a critical value. Numerical results indicate that the time change used with an appropriate value of this ratio also results in quadratic convergence for the calculation of the price, delta and gamma for standard European and American options without the need for Rannacher start-up steps

Data-handling considerations for advanced high-resolution multispectral scanners

Several scanner design parameters that greatly affect data rates were varied to determine overall effect on data rates. Bit rates were calculated for scanners with 10-, 15-, 20-, and 30-meter instantaneous fields of view; with 5, 7, and 10 channels; and with swath widths of 46.3, 92.6, 138.9, and 185.2 kilometers (25, 50, 75, and 100 nautical miles). The data were analyzed to determine whether they could be (1) recorded onboard the spacecraft with currently available equipment, (2) recorded onboard with the equipment proposed for the 1980-90 period, (3) transmitted to earth with current or proposed equipment; and (4) compressed and decompressed without significant degradation of classification accuracy. The effect of classifying 10-meter scanner data on the existing and the development pattern-recognition systems was examined

Opposition policies on identity cards

ID cards are a key point of difference between the main parties. Both the Liberal Democrats and the Conservatives have pledged to scrap them, while Labour will continue with their plans to introduce them. The LSE Identity Project has been following developments in the UK’s Identity Policy since the early days of the Identity Cards Bill in 2005. Here, Dr Edgar A. Whitley and Dr Gus Hosein from the LSE Identity Project analyse the Labour Party’s manifesto comment on identity cards

The political economy of quality measurement: a case study of the USA slaughter cattle market

As agricultural products move from being economic commodities to qualitydifferentiated goods, price dispersion within specific markets increases and implicit subsidies from high quality producers to low quality producers are removed. The present paper examines how these distributional effects can influence patterns of support and opposition to changes in marketing arrangements. The simple model developed is calibrated using data from the USA slaughter cattle market. Estimates of the impact on prices of measuring quality more accurately are found to be similar in size to previous estimates of market power price suppression in the market.Livestock Production/Industries,

Managing competences in entrepreneurial technology firms: a comparative institutional analysis of Germany, Sweden and the UK

Innovative firms face two major kinds of risks in developing new technologies: competence destruction and appropriability. High levels of technical uncertainty and radical changes in knowledge in some fields generate high technical failure risks and make it difficult to plan research and development programmes. They therefore encourage high levels of flexibility in acquiring and using skilled staff. Appropriability risks, on the other hand, encourage innovative firms to develop organisation-specific competences through investing in complementary assets, such as marketing and distribution capabilities, that involve longer-term employer-employee commitments to building complex organisations. These connections between technology risks and employment policies help to explain why different kinds of market economies with contrasting labour market institutions develop varied innovation patterns. This study focuses on subsectors of the computer software and biotechnology industries in three distinct Europea n countries, UK, Germany and Sweden, that vary in their level of technical change and appropriability.n/a

The Power of Debt: Identity and Collective Action in the Age of Finance

The Debt Collective is organized around the possibility for radical action within and against finance capitalism. In the wake of the 2008 financial crisis it was often hard to understand how finance intersected with the everyday lives of ordinary—and especially, poor—people. But in the years since, it has become increasingly clear that mass indebtedness—from the mortgage crisis to student debt, criminal “justice” fines and fees to municipal austerity—is a direct effect of the conflict between debt payments generating value as securitized investments (mortgage backed securities, municipal bond offerings) vs. their role in providing shelter, food, and the ability to merely get by. In the age of finance, debt has become an immersive, systemic problem; but it is one that, in its ubiquity, may hold the seeds of its own solutions. As oil tycoon JP Getty famously quipped: “If you owe the bank $100 that’s your problem. If you owe the bank$100 million, that’s the bank’s problem.” Student debt alone stands today at 1.5 trillion dollars. Together, arguably, we can be the banks’ problem. This is the provocation of the Debt Collective: how can we reframe debt from an issue of isolation and shame to a platform for collective action and political mobilization