Timetabling in constraint logic programming

In this paper we describe the timetabling problem and its solvability in a Constraint Logic Programming Language. A solution to the problem has been developed and implemented in ECLiPSe, since it deals with finite domains, it has well-defined interfaces between basic building blocks and supports good debugging facilities. The implemented timetable was based on the existing, currently used, timetables at the School of Informatics at out university. It integrates constraints concerning room and period availability

Service-oriented logic programming

We develop formal foundations for notions and mechanisms needed to support service-oriented computing. Our work builds on recent theoretical advancements in the algebraic structures that capture the way services are orchestrated and in the processes that formalize the discovery and binding of services to given client applications by means of logical representations of required and provided services. We show how the denotational and the operational semantics specific to conventional logic programming can be generalized using the theory of institutions to address both static and dynamic aspects of service-oriented computing. Our results rely upon a strong analogy between the discovery of a service that can be bound to an application and the search for a clause that can be used for computing an answer to a query; they explore the manner in which requests for external services can be described as service queries, and explain how the computation of their answers can be performed through service-oriented derivatives of unification and resolution, which characterize the binding of services and the reconfiguration of applications

Logical Foundations of Services

In this paper we consider a logical system of networks of processes that interact in an asynchronous manner by exchanging messages through communication channels. This provides a foundational algebraic framework for service-oriented computing that constitutes a primary factor in defining logical specifications of services, the way models of these specifications capture service orchestrations, and how properties of interaction-points, i.e. points through which such networks connect to one another, can be expressed. We formalise the resulting logic as a parameterised institution, which promotes the development of both declarative and operational semantics of services in a heterogeneous setting by means of logic-programming concepts

Entitlement, Rules, Coordination, Club, Market and Hierarchy - General Budget Support Practice and Theory: Implications

The paper discusses implications for practice and theory of the recently completed Joint Evaluation of General Budget Support 2004-06 based on case studies in Burkina Faso, Malawi, Mozambique, Nicaragua, Rwanda, Uganda and Vietnam. The paper first looks at the extent to which general budget support, on the evidence of the evaluation, stands up to common criticisms of the effects of aid on government in low income, aid dependent countries. Allowing for much caution owing to the short period of partnership general budget support (PGBS) programmes in some countries, the finding is that there are small but positive impacts (notably reducing unnecessary transaction costs and increasing discretion of government-thereby raising allocative and operational efficiency). Net benefits are generally greater where PGBS programmes are longer established. ...aid, budget support, entitlement, rules, club, market, coordination

Interpreting mega-development projects as territorial traps: the case of irrigation schemes on the shores of Lake Chad (Borno State, Nigeria)

From the colonial era up to the present, mega-irrigation projects for agriculture have played a key role in the production of state space in Sahelian Africa. Transferring a concept proposed by Agnew (1994) onto a different scale, it is possible to interpret these mega-projects as \u201cterritorial traps\u201d. In fact, they set up boundaries (physical, relational, cognitive and operative) that force evolutive trajectories of the areas involved along rigid pathways. In the aftermath of the systematic failure of the mega-projects, farmers are faced with constraints determined by the trap imposed, without having any of the promised benefits in terms of productive growth, i.e. income. In many situations, the farmers have identified \u201ca means of escape\u201d from these catastrophes by transgressing the boundaries imposed by the territorial traps and reintroducing parts of the infrastructure to a common use. The case study presented regards the irrigation mega-projects on the shores of Lake Chad, in Nigeria

STS in management education: connecting theory and practice

This paper explores the value of science and technology studies (STS) to management education. The work draws on an ethnographic study of second year management undergraduates studying decision making. The nature and delivery of the decision making module is outlined and the value of STS is demonstrated in terms of both teaching method and module content. Three particular STS contributions are identified and described: the social construction of technological systems; actor network theory; and ontological politics. Affordances and sensibilities are identified for each contribution and a discussion is developed that illustrates how these versions of STS are put to use in management education. It is concluded that STS has a pivotal role to play in critical management (education) and in the process offers opportunities for new forms of managin

Framework for constructing multimodal transport networks and routing using a graph database: A case study in London

Most prior multimodal transport networks have been organized as relational databases with multilayer structures to support transport management and routing; however, database expandability and update efficiency in new networks and timetables are low due to the strict database schemas. This study aimed to develop multimodal transport networks using a graph database that can accommodate efficient updates and extensions, high relation-based query performance, and flexible integration in multimodal routing. As a case study, a database was constructed for London transport networks, and routing tests were performed under various conditions. The constructed multimodal graph database showed stable performance in processing iterative queries, and efficient multi-stop routing was particularly enhanced. By applying the proposed framework, databases for multimodal routing can be readily constructed for other regions, while enabling responses to diversified routings, such as personalized routing through integration with various unstructured information, due to the flexible schema of the graph database

Automated generation of constructive ordering heuristics for educational timetabling

Construction heuristics play an important role in solving combinatorial optimization problems. These heuristics are usually used to create an initial solution to the problem which is improved using optimization techniques such as metaheuristics. For examination timetabling and university course timetabling problems essentially graph colouring heuristics have been used for this purpose. The process of deriving heuristics manually for educational timetabling is a time consuming task. Furthermore, according to the no free lunch theorem different heuristics will perform well for different problems and problem instances. Hence, automating the induction of construction heuristics will reduce the man hours involved in creating such heuristics, allow for the derivation of problem specific heuristics and possibly result in the derivation of heuristics that humans have not thought of. This paper presents generation construction hyper-heuristics for educational timetabling. The study investigates the automatic induction of two types of construction heuristics, namely, arithmetic heuristics and hierarchical heuristics. Genetic programming is used to evolve arithmetic heuristics. Genetic programming, genetic algorithms and the generation of random heuristic combinations is examined for the generation of hierarchical heuristics. The hyper-heuristics generating both types of heuristics are applied to the examination timetabling and the curriculum based university course timetabling problems. The evolved heuristics were found to perform much better than the existing graph colouring heuristics used for this domain. Furthermore, it was found that the while the arithmetic heuristics were more effective for the examination timetabling problem, the hierarchical heuristics produced better results than the arithmetic heuristics for the curriculum based course timetabling problem. Genetic algorithms proved to be the most effective at inducing hierarchical heuristics