Update of time-invalid information in Knowledge Bases through Mobile Agents

In this paper, we investigate the use of a mobile, autonomous agent to update knowledge bases containing statements that lose validity with time. This constitutes a key issue in terms of knowledge acquisition and representation, because dynamic data need to be constantly re-evaluated to allow reasoning. We focus on the way to represent the time- validity of statements in a knowledge base, and on the use of a mobile agent to update time-invalid statements while planning for “information freshness” as the main objective. We propose to use Semantic Web standards, namely the RDF model and the SPARQL query language, to represent time-validity of information and decide how long this will be considered valid. Using such a representation, a plan is created for the agent to update the knowledge, focusing mostly on guaranteeing the time-validity of the information collected. To show the feasibility of our approach and discuss its limitations, we test its implementation on scenarios in the working environment of our research lab, where an autonomous robot is used to sense temperature, humidity, wifi signal and number of people on demand, updating the knowledge base with time- valid information

Strategic Planning on the Local Level As a Factor of Rural Development in the Republic of Serbia

The policy of regional rural development has to be efficient. It must relay on so called “good governanceâ€. But in last few decades the results on this segment in the republic of Serbia couldn’t be qualified as significant. So the primary objective of the paper is focused on how to reverse the process of continued impoverishment of the local rural areas and create conditions for social, cultural, economic and environmentally sustainable development based on local initiative. In order to meet this objective, an attempt is made to define systematic, continuous and cyclic approach of setting up priorities and policies as a basic tool for strategic action planning on a local level (LSAP). Decentralization of the state, strengthening of local municipalities and participation of citizens are three processes which had to be articulated and which through their validity has to gain strength and importance in republic of Serbia. The paper can provisionally be divided into two parts. The first part encompasses the importance of local strategic planning as well as justification of theoretical approaches while the second part gives the bases for methodology of strategic action planning on the local level formulation. In such approach two basic preconditions of LSAP could be specified: adequate institutional base i.e. strong participation of local community and its main stakeholders like local government, citizens, NGO’s and others; as well as high level of professional knowledge which builds local stakeholders ability of planning. Introducing of the regional rural approach on the local level is connected with development of LSAP in three basic sectors: institutional – civil society, infrastructural and economic. Local community must be aware what does LSAP mean, why it is so important, what preconditions are important in its development, how it’s structure look like, how it has to be developed, and how to stimulate local initiative, participation, transparency and democracy to reach sustainability.

Introducing Dynamic Behavior in Amalgamated Knowledge Bases

The problem of integrating knowledge from multiple and heterogeneous sources is a fundamental issue in current information systems. In order to cope with this problem, the concept of mediator has been introduced as a software component providing intermediate services, linking data resources and application programs, and making transparent the heterogeneity of the underlying systems. In designing a mediator architecture, we believe that an important aspect is the definition of a formal framework by which one is able to model integration according to a declarative style. To this purpose, the use of a logical approach seems very promising. Another important aspect is the ability to model both static integration aspects, concerning query execution, and dynamic ones, concerning data updates and their propagation among the various data sources. Unfortunately, as far as we know, no formal proposals for logically modeling mediator architectures both from a static and dynamic point of view have already been developed. In this paper, we extend the framework for amalgamated knowledge bases, presented by Subrahmanian, to deal with dynamic aspects. The language we propose is based on the Active U-Datalog language, and extends it with annotated logic and amalgamation concepts. We model the sources of information and the mediator (also called supervisor) as Active U-Datalog deductive databases, thus modeling queries, transactions, and active rules, interpreted according to the PARK semantics. By using active rules, the system can efficiently perform update propagation among different databases. The result is a logical environment, integrating active and deductive rules, to perform queries and update propagation in an heterogeneous mediated framework.Comment: Other Keywords: Deductive databases; Heterogeneous databases; Active rules; Update

Time-Aware Probabilistic Knowledge Graphs

The emergence of open information extraction as a tool for constructing and expanding knowledge graphs has aided the growth of temporal data, for instance, YAGO, NELL and Wikidata. While YAGO and Wikidata maintain the valid time of facts, NELL records the time point at which a fact is retrieved from some Web corpora. Collectively, these knowledge graphs (KG) store facts extracted from Wikipedia and other sources. Due to the imprecise nature of the extraction tools that are used to build and expand KG, such as NELL, the facts in the KG are weighted (a confidence value representing the correctness of a fact). Additionally, NELL can be considered as a transaction time KG because every fact is associated with extraction date. On the other hand, YAGO and Wikidata use the valid time model because they maintain facts together with their validity time (temporal scope). In this paper, we propose a bitemporal model (that combines transaction and valid time models) for maintaining and querying bitemporal probabilistic knowledge graphs. We study coalescing and scalability of marginal and MAP inference. Moreover, we show that complexity of reasoning tasks in atemporal probabilistic KG carry over to the bitemporal setting. Finally, we report our evaluation results of the proposed model

Knowledge revision in systems based on an informed tree search strategy : application to cartographic generalisation

Many real world problems can be expressed as optimisation problems. Solving this kind of problems means to find, among all possible solutions, the one that maximises an evaluation function. One approach to solve this kind of problem is to use an informed search strategy. The principle of this kind of strategy is to use problem-specific knowledge beyond the definition of the problem itself to find solutions more efficiently than with an uninformed strategy. This kind of strategy demands to define problem-specific knowledge (heuristics). The efficiency and the effectiveness of systems based on it directly depend on the used knowledge quality. Unfortunately, acquiring and maintaining such knowledge can be fastidious. The objective of the work presented in this paper is to propose an automatic knowledge revision approach for systems based on an informed tree search strategy. Our approach consists in analysing the system execution logs and revising knowledge based on these logs by modelling the revision problem as a knowledge space exploration problem. We present an experiment we carried out in an application domain where informed search strategies are often used: cartographic generalisation.Comment: Knowledge Revision; Problem Solving; Informed Tree Search Strategy; Cartographic Generalisation., Paris : France (2008

Collective frames of reference, recognition, and managers' mental models of competition: a test in two industries

This work was supported by ESRC grant no. R000232883.Managers draw upon sources of collective knowledge to cognitively represent strategic issues. It has also be argued that cognition is embedded in social interaction, enabling managers to recognize of others’ cognitions. In two separate industries, this study found that the influences upon managers’ mental models of their competitive environment include industry membership, organizational membership, and management level. The results indicate further that recognition of others’ mental models may be more pronounced than cognitive similarity.School of Managemen

Knowledge Management and the Effectiveness of Innovation Outcomes: The Role of Cultural Barriers

In this paper we propose a conceptual model to test the moderating effect of cultural barriers on the link between knowledge strategies and innovation using healthcare organizations. In order to study the tie (knowledge-innovation) and the effects of the moderating variable (cultural barriers), the resource-based view is followed. It has been generally accepted that both explicit and tacit knowledge play a basic role in organizational innovation. However, there are few research works that study the relationship between knowledge management strategy and the effectiveness of the innovation process. On the other hand, the extant research on this relationship has yielded inconclusive results. Our paper revisits this research topic based on data of knowledge management strategy, Knowledge base, cultural barriers and innovation outcomes from a sample of Spanish hospitals

Qualitative conditions of scientometrics: the new challenges'

While scientometrics is now an established field, there are challenges. A closer look at how scientometricians aggregate building blocks into artfully made products, and point-represent these (e.g. as the map of field X) allows one to overcome the dependence on judgements of scientists for validation, and replace or complement these with intrinsic validation, based on quality checks of the several steps. Such quality checks require qualitative analysis of the domains being studied. Qualitative analysis is also necessary when noninstitutionalized domains and/or domains which do not emphasize texts are to be studied. A further challenge is to reflect on the effects of scientometrics on the development of science; indicators could lead to `induced¿ aggregation. The availability of scientometric tools and insights might allow scientists and science to become more reflexive