STENO:an expert system for medical diagnosis based on graphical models and model search

Causal probabilistic models have been suggested for representing diagnostic knowledge in expert systems. This paper describes the theoretical basis for and the implementation of an expert system based on causal probabilistic networks. The system includes model search for building the knowledge base, a shell for making the knowledge base available for users in consultation sessions, and a user interface. The system contains facilities for storing knowledge and propagating new knowledge, and mechanisms for building the knowledge base by semi-automated analysis of a large sparse contingency table. The contingency table contains data acquired for patients in the same diagnostic category as the intended application area of the expert system. The knowledge base of the expert system is created by combining expert knowledge and a statistical model search in a model conversion scheme based on a theory developed by Lauritzen & Spiegelhalter and using exact tests as suggested by Kreiner. The system is implemented on a PC and has been used to simulate the diagnostic value of additional clinical information for coronary artery disease patients under consideration for being referred to coronary arteriography.     

Knowledge transfer and R&D in pharmaceutical companies: A case study

This paper analyzes the consequences for the knowledge transfer and the organization of R&D of pharmaceutical companies after the acquisition of biotech companies. Based on four in-depth case studies, this paper comes to the conclusion that there is no systematic biotechnological know-how transfer from the biotech to the pharmaceutical company after the acquisition. Instead, the biotech companies remain independent and take over the role of centers of excellence for R&D within the pharmaceutical companies because that is the only way of preserving the innovative capabilities of the biotech company.     

Thresholds, productivity, and context: an experimental study on determinants of distributive behaviour

In our questionnaire experiment we confronted students of economics, law and medicine with distributive situations in different contexts characterised by two features inspired by medical decision problems: First, individual threshold values indicate minimal amounts needed by potential recipients of the given resource to obtain positive benefits. Second, recipients differ with respect to their ability to benefit from the given quantity, which indicates the productivity of the resource. Allocations offered in the questionnaire are theoretically grounded. However, respondents were also able to make their own proposals. Well-known allocation rules, but also new procedures, were witnessed. Two multistage principles were most prominent: After distributing all minimal amounts, in a second step one aims for resource-equality while the other principle in the second step demands the maximisation of the sum of payoffs. Besides threshold values and productivity, the acceptance of different principles also depended on the field of study, the degree of scarcity of the resources and the sequential order of situations.     

A structured procedure for materials planning during production transfer

This paper explores materials planning procedures to ensure the materials’ availability during production transfers. The paper defines a production transfer as the preparation, physical transfer and start-up of relocated production. A structured procedure of materials planning during production transfer is developed based on theory, and then validated and refined based on the analysis of four case studies. The paper shows that there is a need for a structured procedure of materials planning during production transfers. It also explains the importance of activities that create prerequisites for the materials’ availability during production transfer, such as updating and adapting documentation, planning and control systems, and describes the activities that ensure the materials’ availability, such as preventive and corrective actions. A valid estimation of the time needed to reach a steady state and a combination of several preventive actions improves the ability to ensure that materials are available. The cases showed differences across company size, because large companies took more and farther-reaching preventive actions.     

A multidimensional view on poverty in the European Union by partial order theory

Poverty can be seen as a multidimensional phenomenon described by a set of indicators, the poverty components. A one-dimensional measure of poverty serving as a ranking index can be obtained by combining the component indicators via aggregation techniques. Ranking indices are thought of as supporting political decisions. This paper proposes an alternative to aggregation based on simple concepts of partial order theory and illustrates the pros and cons of this approach taking as case study a multidimensional measure of poverty comprising three components – absolute poverty, relative poverty and income – computed for the European Union regions. The analysis enables one to highlight conflicts across the components with some regions detected as controversial, with, for example, low levels of relative poverty and high levels of monetary poverty. The partial order approach enables one to point to the regions with the most severe data conflicts and to the component indicators that cause these conflicts.     

Nonparametric Identification and Estimation of Nonadditive Hedonic Models

This paper studies the identification and estimation of preferences and technologies in equilibrium hedonic models. In it, we identify nonparametric structural relationships with nonadditive heterogeneity. We determine what features of hedonic models can be identified from equilibrium observations in a single market under weak assumptions about the available information. We then consider use of additional information about structural functions and heterogeneity distributions. Separability conditions facilitate identification of consumer marginal utility and firm marginal product functions. We also consider how identification is facilitated using multimarket data.