Catálogo de publicaciones - libros

In this paper, a software tool for enabling fuzzy query from a classical database is introduced. By using this tool, some fields (attribute) of a database table can be fuzzified and a supplementary database, which includes fuzzy values, is formed. Developed software tool is applied in a sample database including some fields about the students for the evaluation of scholarship application. It is concluded that, the fuzzy query method is more flexible and the results of such query are more predictive.

Modelling support for knowledge acquisition is a tool for modelling domain knowledge. However, during the implementation of the knowledge new knowledge is created. Event though this knowledge is found in the knowledge base, the model usually is not updated with the new knowledge and do, therefore, not contain all the knowledge in the system. This paper describes how different graphical models support the complex knowledge acquisition process of handling domain knowledge and how these models can be extended by modelling knowledge from rules in a knowledge base including probability. Thus, the models are designed from domain knowledge to create production rules but the models are also extended with new generated knowledge, i.e., generated rules. The paper also describes how different models can support the domain expert to grasp this new generated knowledge and to understand the uncertainty calculated from rules during consultation. To this objective, graphic representation and visualisation is used as modelling support through the use of diagrams of Unified Modelling Language (UML), which is used for modelling production rules. Presenting rules in a static model can make the contents more comprehensible and in a dynamic model can make the uncertainty more evident.

Usually the aim with knowledge management is to increase the profit, through capturing, storing, sharing, and utilising knowledge in an innovative way. Can knowledge management be of use in organisations as schools, where profit is of no interest? This article discusses the need for knowledge management from the perspectives of students, teachers and parents. In a case study master students in computer science developed knowledge-based systems for schools. These systems can be classified as support for (1) students’ learning, (2) students and teachers regarding well being, (3) teachers’ decision making. The conclusion is that intelligent systems, such as knowledge-based systems, could be used in schools, facilitating the knowledge management within the organisation.

In the last decades, there has been extensive use of hypermedia systems in education as a tool for enhancing learning and teaching strategies. But the result of researches shows that little research effort has been directed towards making the presentation and navigation of a hypermedia system more knowledge-based, i.e. driven by knowledge about the information contents [2]. One approach to achieve this is to extend the hypermedia system with techniques from knowledge-based systems. In a hypermedia system chunks of information, stored in nodes, are presented in a non-linear way, similar to the way the human brain process information. Therefore hypermedia systems can be seen as naturally augmenting human abilities to access and process information. Development of a knowledge based hypermedia system for learning is not just about designing a few screens and specifying their relationship. It is also about pedagogical support for learning. Therefore, in this paper some aspects that are important to consider when designing knowledge based hypermedia systems for learning have been addressed.

During the development of a software system, many errors, both physical and logical, sneak into the source code. However, the system’s ability to work properly depends on the ability to find these errors and get rid of them. To this objective, a controller is needed to find and eliminate both types of errors. In this paper, we suggest an approach to a semantic controller, including a syntactic check, by applying tags to production rules. The syntactic check of the controller takes care of the physical errors, and the semantic check takes care of the logical ones.

Knowledge management is used for handling knowledge and activities in real world context. However, knowledge management can also be used for the modelling of robot activities in a real world context. Although robot technology is still under development, Intelligent Service Robots are slowly becoming a reality. The programming of these robots to support a closer interaction with the users is a complex problem including the difficulty of correct modelling of the tasks of the robots. The need for close cooperation between user and robot adds extra complexity, compared to standard models for task modelling. In this paper we outline a representation scheme, Task Pattern Analysis (TAPAS), that is directed towards a notion of activities as rule-based behaviours. In task pattern analysis, the tasks are described in terms of Task Patterns, consisting of a frame rule, and Task Fragments, specifying and constraining the applicability of the rules.

A formal model of knowledge representation and reasoning for temporally rich domains is given in the paper. The model is based on the high-level Petri Nets, called the Petri Nets with Time Tokens (PNTT). The PNTT is the main building block of the knowledge representation scheme KRPNTT. The scheme integrates theory of the PNTT and Allen’s interval-based temporal logic. Reasoning process in the proposed scheme is It includes the ability to reason about time relations among actions and/or states, as well as planning in the temporally rich domains.

To specify, verify, and reason about various reciprocal relationships in a human society and/or a cyber space, we need a right fundamental logic system to provide us with a criterion of logical validity of reasoning as well as a representation and specification language. This paper proposes a new family of conservative extensions of relevant logic, named “reciprocal logic,” for specifying, verifying, and reasoning about reciprocal relationships. The paper shows that various reciprocal logics can be obtained by introducing predicates and related axioms about reciprocal relationships into strong relevant logics and spatial-temporal relevant logics. A case study is focused on trust relationships.

The integration of WLANs and CDMA networks has recently evolved into hot issue. We propose a vertical handoff algorithm between WLAN and CDMA network. A handoff initiation is decided by the received signal strength (RSS). To reduce the unnecessary handoff probability, we also consider a distance. As a mechanism of network selection, we propose a context based network selection algorithms between WLAN to CDMA network, based on wireless channel assignment such as dropping probability, blocking probability, GoS (Grade of Service), the number of handoff attempts. As a decision making criterion, velocity threshold is determined to optimize the system performance. The optimal velocity threshold is adjusted to assign available channels to the mobile stations. The proposed scheme is validated by computer simulation.

This paper presents the first mediated certificateless public key encryption and signature schemes. We also extend our schemes into hierarchical schemes. Our schemes does not suffer from the key escrow property that seems to be inherent in the mediated identity-based schemes. Key escrow is not always a good property for all applications because the exposure of a master key enable all the users’ private keys to be leaked. Our mediated certificateless public key encryption and hierarchical schemes also support role based access control (RBAC) without the key escrow to manage the access to resources of a system. We finally describe security of our schemes and compare our schemes with the mediated identity based schemes from efficiency points of view.