Adjoint exactness

Plato's ideas and Aristotle's real types from the classical age, Nominalism and Realism of the mediaeval period and Whitehead's modern view of the world as pro- cess all come together in the formal representation by category theory of exactness in adjointness (a). Concepts of exactness and co-exactness arise naturally from ad- jointness and are needed in current global problems of science. If a right co-exact valued left-adjoint functor ( ) in a cartesian closed category has a right-adjoint left- exact functor ( ), then physical stability is satis ed if itself is also a right co-exact left-adjoint functor for the right-adjoint left exact functor ( ): a a . These concepts are discussed here with examples in nuclear fusion, in database interroga- tion and in the cosmological ne structure constant by the Frederick construction

State-of-the-art on evolution and reactivity

This report starts by, in Chapter 1, outlining aspects of querying and updating resources on the Web and on the Semantic Web, including the development of query and update languages to be carried out within the Rewerse project. From this outline, it becomes clear that several existing research areas and topics are of interest for this work in Rewerse. In the remainder of this report we further present state of the art surveys in a selection of such areas and topics. More precisely: in Chapter 2 we give an overview of logics for reasoning about state change and updates; Chapter 3 is devoted to briefly describing existing update languages for the Web, and also for updating logic programs; in Chapter 4 event-condition-action rules, both in the context of active database systems and in the context of semistructured data, are surveyed; in Chapter 5 we give an overview of some relevant rule-based agents frameworks

Intelligent Agents - a Tool for Modeling Intermediation and Negotiation Processes

Many contemporary problems as encountered in society and economy require advanced capabilities for evaluation of situations and alternatives and decision making, most of the time requiring intervention of human agents, experts in negotiation and intermediation. Moreover, many problems require the application of standard procedures and activities to carry out typical socio-economic processes (for example by employing standard auctions for procurement or supply of goods or convenient intermediation to access resources and information). This paper focuses on enhancing knowledge about intermediation and negotiation processes in order to improve quality of services and optimize performances of business agents, using new computational methods that combine formal methods with intelligent agents paradigm. Taking into account their modularity and extensibility, agent systems allow facile, standardized and seamless integration of negotiation protocols and strategies by employing declarative and formal representations specific to computer science.Business processes, Intelligent Agents, Intermediation and Negotiation, Formal Models.

In Search of the Market: Lessons from Analyzing Agricultural Transition in Central and Eastern Europe

Studies of the transition process remind us of Stiglitz's comparison between pathology and the economic analysis of institutions (1989): asking what went wrong and what did not is the essence of understanding the functioning of social systems. Thus, carefully conducted empirical studies of the transition process itself may yield elucidative results applicable not only to theory but also to institutional policy changes in transition. This paper presents the key findings of KATO, a comprehensive research project focussing on the transition process of agriculture in Central and Eastern Europe. From 1997 to 2000, the project empirically examined processes of liberalization and market development, privatization and property rights changes, as well as restructuring and path dependencies in three Central and Eastern Europe countries: Poland, the Czech Republic and Bulgaria. Conclusions on three analytical levels are drawn: (1) the empirical design for analyzing rapidly changing and evolving institutions in transition economies, (2) the suitability of different theoretical approaches for understanding transition, and (3) policy recommendations targeting better governance and an improved institutional framework.Agricultural and Food Policy,

IT governance in SMEs: trust or control?

It is believed by many scholars that a small and medium-sized enterprise (SME) cannot be seen through the lens of a large firm. Theories which explain IT governance in large organizations and methodologies used by practitioners can therefore not be extrapolated to SMEs, which have a completely different economic, cultural and managerial environment. SMEs suffer from resource poverty, have less IS experience and need more external support. SMEs largely contribute to the failure of many IS projects. We define an out-sourced information system failure (OISF) as a failure of IT governance in an SME environment and propose a structure for stating propositions derived from both agency theory and theory of trust. The theoretical question addressed in this paper is: how and why do OISFs occur in SMEs? We have chosen a qualitative and positivistic IS case study research strategy based on multiple cases. Eight cases of IS projects were selected. We found that trust is more important than control issues like output-based contracts and structured controls for eliminating opportunistic behaviour in SMEs. We conclude that the world of SMEs is significantly different from that of large companies. This necessitates extra care to be taken on the part of researchers and practitioners when designing artefacts for SMEs

Database Systems - Present and Future

The database systems have nowadays an increasingly important role in the knowledge-based society, in which computers have penetrated all fields of activity and the Internet tends to develop worldwide. In the current informatics context, the development of the applications with databases is the work of the specialists. Using databases, reach a database from various applications, and also some of related concepts, have become accessible to all categories of IT users. This paper aims to summarize the curricular area regarding the fundamental database systems issues, which are necessary in order to train specialists in economic informatics higher education. The database systems integrate and interfere with several informatics technologies and therefore are more difficult to understand and use. Thus, students should know already a set of minimum, mandatory concepts and their practical implementation: computer systems, programming techniques, programming languages, data structures. The article also presents the actual trends in the evolution of the database systems, in the context of economic informatics.database systems - DBS, database management systems – DBMS, database – DB, programming languages, data models, database design, relational database, object-oriented systems, distributed systems, advanced database systems

Recovery within long running transactions

As computer systems continue to grow in complexity, the possibilities of failure increase. At the same time, the increase in computer system pervasiveness in day-to-day activities brought along increased expectations on their reliability. This has led to the need for effective and automatic error recovery techniques to resolve failures. Transactions enable the handling of failure propagation over concurrent systems due to dependencies, restoring the system to the point before the failure occurred. However, in various settings, especially when interacting with the real world, reversal is not possible. The notion of compensations has been long advocated as a way of addressing this issue, through the specification of activities which can be executed to undo partial transactions. Still, there is no accepted standard theory; the literature offers a plethora of distinct formalisms and approaches. In this survey, we review the compensations from a theoretical point of view by: (i) giving a historic account of the evolution of compensating transactions; (ii) delineating and describing a number of design options involved; (iii) presenting a number of formalisms found in the literature, exposing similarities and differences; (iv) comparing formal notions of compensation correctness; (v) giving insights regarding the application of compensations in practice; and (vi) discussing current and future research trends in the area.peer-reviewe