This issue of Computer Science and Information Systems consists of 13 regular articles and two special sections: “Engineering of Computer Based Systems,” guest-edited by Bernard Schätz, which contains six articles that represent expanded versions of papers selected from the 19th Annual IEEE International Conference and Workshops on the Engineering of Computer Based Systems (ECBS), and “Information Technologies in Medicine and Rehabilitation,” guest-edited by Goran Devedžić, which brings forth four papers that describe new developments in the interdisciplinary field of biomedical engineering. We would like to use this opportunity to thank the guest editors, as well as article authors and reviewers, for helping to bring this diverse issue of ComSIS to our readers.

In the first regular article, “WebMonitoring Software System: Finite State Machines for Monitoring the Web,” Vesna Pajić et al. present a system based on finite-state machines that successfully solves two problems regarding information search on the Web: enabling effective complex search queries that transcend keywords, and accessing Web-page content that would otherwise be hidden due to crawling limitations and time lags.

Dušan Okanović et al., in “SLA-Driven Adaptive Monitoring of Distributed Applications for Performance Problem Localization,” describe DProf – an adaptive approach to application-level monitoring of software systems which allows changing the instrumentation of software operations in monitored distributed applications at runtime. This is achieved by specifying performance objectives in service level agreements (SLAs) and using call tree information to detect and localize problems in application performance.

“A Scalable Multiagent Platform for Large Systems” by Juan M. Alberola et al. introduces a new multi-agent platform developed at the level of the operating system, facilitating high efficiency and scalability to large populations of agents that require fast messaging services, agent group management, and security checks.

The article “Validation of Schema Mappings with Nested Queries” by Guillem Rull et al. tackles the problem of validating XML schema mappings, focusing on nested relational schemas. Validation is performed through reasoning on schemas and mapping definition, by encoding the given mapping scenario into flat database schema, and reformulating property checks as query satisfiability problems.

In “Accessibility Algorithm Based on Site Availability to Enhance Replica Selection in a Data Grid Environment,” Ayman Jaradat et al. present a replica selection algorithm for data grid environments that considers site availability in addition to data transfer time, providing better estimates of response time compared to existing approaches which do not take site availability into account.

Raka Jovanovic and Milan Tuba, in their article “Ant Colony Optimization Algorithm with Pheromone Correction Strategy for the Minimum Connected Dominating Set Problem,” give special attention to the initial condition of the colony optimization (ACO) algorithm for the minimum connected dominating set problem (MCDSP), also adding a pheromone correction strategy. The two innovations avoid entrapment in local optima, as well as reduce complexity of the ACO algorithm.

“Ontological Model of Legal Norms for Creating and Using Legislation,” by Stevan Gostojić, Branko Milosavljević and Zora Konjović, presents a formal model of legal norms modeled in OWL. Unlike existing approaches that model legal norms by formal logic, rules or ontologies, the approach presented in this article is intended for semiautomatic drafting and semantic retrieval and browsing of legislation.

George Lagogiannis, Nikos Lorentzos, and Alexander B. Sideridis, in “Indexing Moving Objects: A Real Time Approach,” tackle the problem of reducing the I/O bottleneck when indexing moving objects by minimizing the number of I/Os in such a way that queries concerning the present and past positions of the objects can be answered efficiently. The authors propose two approaches that achieve an asymptotically optimal number of such I/Os, based on the assumption that the primary memory suffices for storing the current positions of the objects.

In “Multi-sensor Data Fusion Based on Consistency Test and Sliding Window Variance Weighted Algorithm in Sensor Networks,” Jian Shu et al. tackle the problem of reduced accuracy of sensor data due to zero offset and decreased stability of wireless sensor networks by proposing an algorithm for detecting abnormal data based on consistency tests and sliding window variance. The article shows that amending or removing abnormal sensor data using the proposed method results in better precision compared to existing approaches.

Zhang Yong-Xin, Li Qing-Zhong and Peng Zhao-Hui, in “A Novel Method for Data Conflict Resolution using Multiple Rules,” examine the issue of conflict resolution during data integration by considering the interplay of data conflict resolution on different attributes, instead of focusing on resolving conflicts between single attributes. They propose a two-stage procedure based on Markov Logic Networks, and show that the proposed approach can significantly improve the accuracy of data conflict resolution in real-world scenarios.

The following three articles are significantly extended and improved versions of papers presented at the 5th International Conference on Information Technology (ICIT 2011) that underwent the regular submission and reviewing procedure.

The article “Ontology-Based Architecture with Recommendation Strategy in Java Tutoring System” by Boban Vesin et al. presents Protus 2.0, the new version of the tutoring system for learning basic concepts of Java programming language, focusing on its modular architecture where each Protus 2.0 component is represented by a specific ontology, and course personalization achieved through learner style identification and content recommendation.

“A Viewpoint of Tanzania E-Commerce and Implementation Barriers” by George S. Oreku, Fredrick J. Mtenzi and Al-Dahoud Ali discusses the prospects of e-commerce implementation, participation, motivation and opportunity in developing countries like Tanzania, with large domestic markets and potentials for the development of the agricultural sector. The paper concludes that Tanzanians have the ability to participate in e-commerce, but with the need for improving the national image by introducing trust and discipline.

Finally, Slavica Aleksić et al., in the article “A Design Specification and a Server Implementation of the Inverse Referential Integrity Constraints,” present an approach to the automated implementation of inverse referential integrity constraints (IRICs) within the SQL Generator tool developed as a part of the IIS*Studio development environment. The paper describes the algorithms for insertion, modification and deletion control, and illustrates them through an example of generated procedures/triggers.

Mirjana Ivanović

Managing Editor
Miloš Radovanović