On Computer-Assisted Proofs in Ordinal Number Theory

Some basic theorems about ordinal numbers were proved using McCunes computer program OTTER, building on Quaifes modification of Gödels class theory. Our theorems are based on Isbells elegant definition of ordinals. Neither the axiom of regularity nor the axiom of choice is used.     

Obvious inferences

The notion of obvious inference in predicate logic is discussed from the viewpoint of proof-checker applications in logic and mathematics education. A class of inferences in predicate logic is defined and it is proposed to identify it with the class of obvious logical inferences. The definition is compared with other approaches. The algorithm for implementing the obviousness decision procedure follows directly from the definition.     

Applying Dialectic Agents to Argumentation in E-Commerce

Reaching an agreement or understanding through argumentation is an important aspect of decision making in a virtual society as well as in our real society. In this paper, we consider compromise (Aufheben) and concession (weaker Aufheben) as a simple form of Hegelian dialectical reasoning, which we think are desiderata to deliberate or cognitive agents. We then propose an argument-based agent system that allows for the issue modification among agents concerned during argumentation and reaching an agreement or understanding through argumentation with the dialectical reasoning capability. We illustrate its potential usefulness by showing applications to seller and buyer agents and traveling salesman agents in e-commerce.     

Online and multiplayer gaming — An overview

This paper gives a broad overview of the technology and market for on-line and multiplayer computer gaming. Some economic considerations and their influence on the choice of technologies are examined. Particular attention is given to the massively-multiplayer and persistent world type of games, and the special problems that arise in these environments. Lastly, some ongoing problems are investigated, particularly the thorny issue of cheating in multiplayer games.     

Validating the PSL/Sugar Semantics Using Automated Reasoning

The Accellera organisation selected Sugar, IBMs formal specification language, as the basis for a standard to drive assertion-based verification in the electronics industry. Sugar combines regular expressions, Linear Temporal Logic (LTL) and Computation Tree Logic (CTL) into a property language intended for both static verification (e.g. model checking) and dynamic verification (e.g. simulation). In 2003 Accellera decided to rename the evolving standard to Accellera Property Specification Language (or PSL for short). We motivate and describe a deep semantic embedding of PSL in the version of higher-order logic supported by the HOL 4 theorem-proving system. The main goal of this paper is to demonstrate that mechanised theorem proving can be a useful aid to the validation of the semantics of an industrial design language.     

A decision support tool for the diagnosis of breast cancer based upon Fuzzy ARTMAP

This paper presents research into the application of the fuzzy ARTMAP neural network model to the diagnosis of cancer from fine-needle aspirates of the breast. Trained fuzzy ARTMAP networks are differently pruned so as to maximise accuracy, sensitivity and specificity. The differently pruned networks are then employed in a cascade of networks intended to separate cases into certain and suspicious classes. This mimics the predictive behaviour of a human pathologist. The fuzzy ARTMAP model also provides symbolic rule extraction facilities and the validity of the derived rules for this domain is discussed. Additionally, results are provided showing the effects upon network performance of different input features and different observers. The implications of the findings are discussed.     

Creating Assemblies in Public Environments: Social Interaction,Interactive Exhibits and CSCW

This paper examines the use of a series of three low tech interactive assemblies that have been exhibited by the authors in a range of fairs, expositions and galleries. The paper does not present novel technical developments, but rather uses the low tech assemblies to help scope out the design space for CSCW in museums and galleries and to investigate the ways in which people collaboratively encounter and explore technological exhibits in museums and galleries. The bulk of the paper focuses on the analysis of the use of one interactive installation that was exhibited at the Sculpture, Objects and Functional Art (SOFA) Exposition in Chicago, USA. The study uses audio–visual recordings of interaction with and around the work to consider how people, in and through their interaction with others, make sense of an assembly of traditional objects and video technologies. The analysis focuses on the organised practices of assembly and how assembling the relationship between different parts of the work is interactionally accomplished. The analysis is then used to develop a series of design sensitivities to inform the development of technological assemblies to engender informal interaction and sociability in museums and galleries.     

Relationship analysis in requirements engineering

This research addresses a major shortcoming in todays requirements analysis techniques—the lack of a rigorous and comprehensive process to explicitly capture the relationship structure of the problem domain. Whereas other analysis techniques lightly address the relationship discovery process, relationship analysis (RA) is a systematic, domain-independent analysis technique focusing exclusively on a domains relationship structure. This paper describes RAs taxonomy of relationship types and corresponding brainstorming questions for eliciting the relationship structure from a domain expert. A preliminary case study analysis of online bookstores using RA as well as a formal experiment have both confirmed RAs effectiveness in helping the analyst produce significantly higher quality requirements. RA should become an invaluable tool for analysts, irrespective of the software engineering approach taken during systems analysis.     

Japanese educational and learning systems in the post-industrial society: A value chain of educational and learning systems

Japan's educational system has some major problems. The most important among these concerns is the basic concept of the educational process and the goal of education. The old concept of public educational systems has become outdated in today's Japanese society, although this concept had supported social and spiritual faith, economic success and selfless devotion to one's country for more than 100 years. Now, Japanese people need a new concept of the educational process and the goal of education for the twenty-first century. The paper proposes a value chain of educational and learning systems aimed at building a network consisting of multiple fields for fostering future human resources.     

Tracking Context Changes through Meta-Learning

The article deals with the problem of learning incrementally (on-line) in domains where the target concepts are context-dependent, so that changes in context can produce more or less radical changes in the associated concepts. In particular, we concentrate on a class of learning tasks where the domain provides explicit clues as to the current context (e.g., attributes with characteristic values). A general two-level learning model is presented that effectively adjusts to changing contexts by trying to detect (via meta-learning) contextual clues and using this information to focus the learning process. Context learning and detection occur during regular on-line learning, without separate training phases for context recognition. Two operational systems based on this model are presented that differ in the underlying learning algorithm and in the way they use contextual information: METAL(B) combines meta-learning with a Bayesian classifier, while METAL(IB) is based on an instance-based learning algorithm. Experiments with synthetic domains as well as a number of real-world problems show that the algorithms are robust in a variety of dimensions, and that meta-learning can produce substantial increases in accuracy over simple object-level learning in situations with changing contexts.     

‘Use’ discourses in system development: Can communication be improved?

This paper aims to provide a basis for renewed talk about use in computing. Four current discourse arenas are described. Different intentions manifest in each arena are linked to failures in translation, different terminologies crossing disciplinary and national boundaries non-reflexively. Analysis of transnational use discourse dynamics shows much miscommunication. Conflicts like that between the Scandinavian System Development School and the usability approach have less current salience. Renewing our talk about use is essential to a participatory politics of information technology and will lead to clearer perception of the implications of letting new systems becoming primary media of social interaction.     

Two and three-quarter dimensional meshing facilitators

This paper presents generated enhancements for robust two and three-quarter dimensional meshing, including: (1) automated interval assignment by integer programming for submapped surfaces and volumes, (2) surface submapping, and (3) volume submapping. An introduction to the simplex method, an optimization technique of integer programming, is presented. Simplification of complex geometry is required for the formulation of the integer programming problem. A method of i-j unfolding is defined which explains how irregular geometry can be realigned into a simplified form that is suitable for submap interval assignment solutions. Also presented is the processes by which submapping eliminates the decomposition of surface geometry, through a pseudodecomposition process, producing suitable mapped meshes. The process of submapping involves the creation of interpolated virtual edges, user defined vertex types and i-j-k space traversals. The creation of interpolated virtual edges is the method by which submapping automatically subdivides surface geometry. The interpolated virtual edge is formulated according to an interpolation scheme using the node discretization of curves on the surface. User defined vertex types allow direct user control of surface decomposition and interval assignment by modifying i-j-k space traversals. Volume submapping takes the geometry decomposition to a higher level by using mapped virtual surfaces to eliminate decomposition of complex volumes.     

Modular Control and Coordination of Discrete-Event Systems

In the supervisory control of discrete-event systems based on controllable languages, a standard way to handle state explosion in large systems is by modular supervision: either horizontal (decentralized) or vertical (hierarchical). However, unless all the relevant languages are prefix-closed, a well-known potential hazard with modularity is that of conflict. In decentralized control, modular supervisors that are individually nonblocking for the plant may nevertheless produce blocking, or even deadlock, when operating on-line concurrently. Similarly, a high-level hierarchical supervisor that predicts nonblocking at its aggregated level of abstraction may inadvertently admit blocking in a low-level implementation. In two previous papers, the authors showed that nonblocking hierarchical control can be guaranteed provided high-level aggregation is sufficiently fine; the appropriate conditions were formalized in terms of control structures and observers. In this paper we apply the same technique to decentralized control, when specifications are imposed on local models of the global process; in this way we remove the restriction in some earlier work that the plant and specification (marked) languages be prefix-closed. We then solve a more general problem of coordination: namely how to determine a high level coordinator that forestalls conflict in a decentralized architecture when it potentially arises, but is otherwise minimally intrusive on low-level control action. Coordination thus combines both vertical and horizontal modularity. The example of a simple production process is provided as a practical illustration. We conclude with an appraisal of the computational effort involved.     

Artificial morality and artificial law

The article investigates the interplay of moral rules in computer simulation. The investigation is based on two situations which are well-known to game theory: the prisoner's dilemma and the game of Chicken. The prisoner's dilemma can be taken to represent contractual situations, the game of Chicken represents a competitive situation on the one hand and the provision for a common good on the other. Unlike the rules usually used in game theory, each player knows the other's strategy. In that way, ever higher levels of reflection are reached reciprocally. Such strategies can be interpreted as moral rules.Artificial morality is related to the discipline of Artificial Life. As in artificial life, the use of genetic algorithms suggests itself. Rules of behaviour split and reunite as chromosome strings do.     

Toward Cultural Oncology: The Evolutionary Information Dynamics of Cancer

'Racial' disparities among cancers, particularly of the breast and prostate, are something of a mystery. For the US, in the face of slavery and its sequelae, centuries of interbreeding has greatly leavened genetic differences between Blacks and Whites, but marked contrasts in disease prevalence and progression persist. Adjustment for socioeconomic status and lifestyle, while statistically accounting for much of the variance in breast cancer, only begs the question of ultimate causality. Here we propose a more basic biological explanation that extends the theory of immune cognition to include an elaborate tumor control mechanism constituting the principal selection pressure acting on pathologically mutating cell clones. The interplay between them occurs in the context of an embedding, highly structured, system of culturally-specific psychosocial stress. A rate distortion argument finds that larger system able to literally write an image of itself onto the disease process, in terms of enhanced risk behaviour, accelerated mutation rate, and depressed mutation control. The dynamics are analogous to punctuated equilibrium in simple evolutionary systems, accounting for the staged nature of disease progression. We conclude that 'social exposures' are, for human populations, far more than incidental cofactors in cancer etiology. Rather, they are part of the basic biology of the disorder. The aphorism that culture is as much a part of human biology as the enamel on our teeth appears literally true at a fundamental cellular level.     

Negotiating Boundaries. Configuration Management in Software Development Teams

Using case-study material from threesmall software development teams, this paper analysesthe regionalisation of design spaces. Its mainpurpose is to understand problems and practices ofcooperative work in such spaces. Configurationmanagement is used to denote both a practice andsupporting software tools and their relationship. Amajor concern is how to develop practices and toolsthat support cooperation across multipleorganisational and social boundaries whilesimultaneously being respectful of regionalisations.     

Technology and prognostic predicaments

As societies become increasingly technologised, the need for careful and critical assessment rises. However, attempts to assess or normatively evaluate technological development invariably meet with an antinomy: both structurally and historically, technologies display multistable possibilities regarding uses, effects, side effects and other outcomes. Philosophers, usually expected to play applied ethics roles, often come to the scene after these effects are known. But others who participate at the research and development stages find even more difficulties with prognosis. Recent work on revenge effects (Tenner) and negative side effects (Kevles) are examined, as well as several cases of philosophers in R&D roles. After sketching the antinomy,I outline a heuristic pragmatics of prognosis that addresses this quandary.     

‘Systemic rationalization’ in Austria: Social and political mediation in technology use and work organization

The paper analyses restructuring processes occuring with the introduction of information technologies into firms in Austria and assesses how far the evidence lends support to the thesis of a fundamental change in rationalization patterns as postulated by continental industrial sociologists claiming the emergence of a novel type of systemic rationalization. Based on a research perspective putting emphasis on several levels of social mediation of technological change the broad conclusion is the following: there are clear indications of a novel systemic approach to rationalization but the associated forms of work organization show substantial variation. The analysis of the influence of national-level institutions, industry- and firm-specific conditions, and their role in micro-political processes of system and work design, points towards an underutilization of work humanization potentials and suggests an increase in skill supply as one of the possible intervention strategies.     

Application of the general elimination method in robot kinematics

A general method for solving the robot inverse kinematics problem is presented. The method is based upon the general elimination method to obtain the equivalent system of equations which are triangularized and the solutions of the inverse kinematics problem can be solved by backsubstitutions.     

A two-layer fuzzy pattern matching procedure for the evaluation of conditions involving vague quantifiers

In this note, we are interested in the evaluation of conditions of the form The value of attribute a for Q items of X is in F or more shortly Q items of X are F, where X is a set of items, Q denotes a possibly vague proportion (which may be linguistically expressed, e.g. most), F is a (possibly fuzzy) subset of the attribute domain of a. and where the available knowledge about the value a(x) of the attribute a for any item x may be imprecise or even vague. The evaluation is based on a fuzzy pattern matching procedure repeated two times. Such conditions may be encountered in queries addressed to an incomplete information data base or in the if-part of expert rules.