================================ VOLUME 17 NUMBER 3 NOVEMBER 1993 ================================ 1. AN $O(\sqrt{N})$ TOKEN BASED DISTRIBUTED MUTUAL EXCLUSION ALGORITHM Kia Makki, Department of Computer Science, University of Nevada, Las Vegas, Las Vegas, Nevada AND Niki Pissinou, Center For Advanced Computer Studies, University of Southwestern Louisiana, Lafayette, Louisiana AND Yelena Yesha, Computer Science Department, University of Maryland Baltimore County, Baltimore, Maryland pp. 221-231 keywords: distributed systems, distributed mutual exclusion, critical section, distributed algorithms, communication networks abstract: In this paper, we present a token based distributed mutual exclusion algorithm for a distributed computer system of $N$ sites. The proposed algorithm is based on timestamps and the theory of finite projective planes. It also makes use of a ``Token Queue'' which is part of the token and contains a list of all sites which are requesting the token. The algorithm is deadlock free, free from starvation, and requires no message exchange in the best case, and $4\sqrt{N}-2$ message exchanges in the worst case per critical section execution. ----------------------- 2. QUALITY OF DECISION RULES: EMPIRICAL AND STATISTICAL APPROACHES Ivan Bruha, McMaster University, Dept Computer Science and Systems, Hamilton, Ont., Canada L8S4K1, bruha@maccs.dcss.mcmaster.ca AND Sylva Ko\v{c}kov\'a, Institute of Computer Science, Czech Academy of Sciences, 18200 Praha 8, Czech Republic sylva@uivt1.uivt.cas.cs pp. 223-253 keywords: decision rule, rule quality, contingency table, measure of association, measure of agreement abstract: It is useful within certain classification procedures that each decision rule induced by a learning algorithm be associated with a numerical factor which can express its properties and characterize a measure of belief in correctness of the rule, its power, predictability, reliability, likelihood, etc. A collection of these properties is symbolized by a function commonly called the rule quality. The paper presents two approaches to the definition of the rule quality: empirical and statistical. Overview of several practical formulas of rule quality used in inductive learning algorithms are introduced and their characteristics compared. General characteristics of a function which may be used as rule quality are pointed out, namely its monotony towards the consistency and completeness of decision rules. Statistical tools such as contingency table, measure of association, measure of agreement are introduced as suitable vehicles for depicting a behaviour of a decision rule. ----------------------- 3. LOGOS OF THE INFORMATIONAL Anton P. \v{Z}eleznikar, Volari\v{c}eva ulica 8, 61111 Ljubljana, Slovenia, anton.p.zeleznikar@ijs.si pp. 245-266 keywords: axiom, definition, externalism, informational entity, informing, internalism, logic, metaphysicalism, parallelism, phenomenalism abstract: This paper is a preliminary study and presents a possibility how to begin the axiomatizing of the phenomenon that we call the informational and how to deduce still other axioms from the basic axiomatic viewpoint. If we solve the problem of an adequate formalization---introducing a symbolic and symbolically open language---the question of the logical consistency may still remain open. This situation may or may not represent an inadmissible position within different sciences. For after all, sciences have to deal with questions that rise the level of the traditional logical views and scientific disciplinability to a higher position of scientific cognition. Informational logic can offer a new and more critical view as it is customary in sciences rooting in classical logic. The logic of informational sets new standards that consider the active, also creative capabilities of informational entities in question. Decomposition and composition of entities in a parallel, spontaneous, circular, and intentional way can be the path on which parallelism, spontaneity, circularity, and intentionality become constructive capabilities of the informing of entities. ----------------------- 4. THE INFORMATION TECHNOLOGY (IT) FOR ENABLING DISABLED PEOPLE -- A STRATEGIC AGENDA -- On-Kwok Lai, Lecturer in Sociology, Department of Sociology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, Fax:(852) 858 7604, (852) 603 5213 pp. 267-276 keywords: Social Welfare, Health Promotion, Disabled People,Informational Society, Family, Community Network, S.E.Asia abstract: The agenda and strategy building for enabling the disabled and needy people via Information Technology (IT) will be the major health and welfare issue in both developing and developed countries in the coming century. This paper, based upon some comparative findings and projected scenarios in East Asian countries, tries to examine the feasibility of and argue for the IT enhanced enabling (disabled people) approach in health and welfare promotion. Part One of the paper examines, analytically and historically, the case of Asian experience in: (1) traditional forms of social response towards the disabled people, (2) modern organized form of social services for the disabled, and (3) the futuristic individually tailor-made services for the disabled via IT provision in different communities. In Part Two, findings and observations in the Asian context are outlined and discussed. Three major arena of possible integration between IT and disabled people are identified: within family system, in the functional (e.g. disabled) groups, and in the new form of community. Coupled with a discussion on the gender issues of the IT in health and welfare promotion, the respective specificity of the arena will be articulated. Also, the differential albeit inter-related rate and intensity of IT utilization in different arena will be examined. The related analyses, as argued in Part Three, indicate the feasibility of the informational based disabled community networking, in and through which the disabled can be integrated into normal life. But, the effectiveness of this approach is, articulated in the later part, contingent upon the variables embedded in the technology -namely, risks- and social structure. The paper ends with a set of agenda and policy-related strategies for enabling the disabled in the 1990s and beyond within the global context. ----------------------- 5. A COMBINED ALGORITHM FOR TESTING IMPLICATIONS OF FUNCTIONAL AND MULTIVALUED DEPENDENCIES Mirko Malekovi\'{c}, University of Zagreb, Faculty of Organization and Informatics, Pavlinska 2, 42000 Vara\v{z}din, Croatia pp. 277-283 keywords: algorithms, correctness, dependency theory, functional and multivalued dependencies, implication problem, informativeness, time complexity abstract: In this paper a combined algorithm for testing implication problem, F \models f, where F is a set of functional or multivalued dependencies, and f is a functional or multivalued dependency, is presented. The algorithm combines two well known algorithms. The first algorithm solves the implication problem F \models f, where F is a set of functional dependencies and f is a functional dependency (the algorithm is based on the closure of a set of attributes [Maier 83]). The other algorithm solves the problem F \models f, where F is a set of functional or multivalued dependencies and f is a functional or multivalued dependency (the algorithm is based on the dependency basis [Beeri 80]). The time complexity of the new algorithm is the same as one of the algorithm in [Beeri 80]. In addition, the new algorithm is more informative than the algorithms in [Maier 83] and [Beeri 80] in so far as the new algorithm includes the result explanations RE1 and RE2 that indicate how the imlication problem F \models f is solved; the algorithms in [Maier 83] and [Beeri 80] produce only the answer `Yes' or the answer `No'. Also, RE1 and RE2 contain the proof of the correctness of the new algorithm. ----------------------- 6. GLOBAL MODERNIZATION PLAN OF TELECOMMUNICATIONS, INFRASTRUCTURE AND SERVICES IN SLOVENIA (MTIS) (a technical paper) Gorazd Kandus, Institute Jo\v{z}ef Stefan, Jamova 39, Ljubljana, E-mail: gorazd.kandus@ijs.si Currently at FZI, Universit\"at Karlsruhe, Germany, as a Fellow of the Commission of the European Communities AND Iztok Tvrdy, ASTER d.o.o., Ljubljana, E-mail: iztok.tvrdy@aster.si pp. 297-331 keywords: telecommunications, services, informatics, infrastructure, strategy, national plan, Slovenia, MTIS abstract: Outline of the global modernization plan of information technology and telecommunications infrastructure in Slovenia (MTIS) is presented in the paper. The preparation of this plan has been based on reference documents, supplied by major actors, represented in the Commission for Policy and Strategy of further Telecommunications Development. Its objective is to activate the modernization process, that consists of principles, methodologies and development scenarios of all topics covered by MTIS. The operational plan with detailed analysis of investments, timing and responsibilities will be object of the further document, the Master Plan, which will be produced immediately after the approval of MTIS. MTIS has been primarily focused on the existing status of telecommunications infrastructure and services and on the innovation aspects of the unification of the telecommunications and information technology based on the convergency of needs of different sectors. With the respect to the development three fundamental scenarios, namely natural, accelerated and survival scenario have been presented. The accelerated scenario has been proposed to be brought into effect as soon as possible.