VOLUME 25 NUMBER 2 2001

Abstracts:

OZ is a distance learning environment for lectures, seminaries, and exercises in computer science at Humboldt-University, where "OZ" means distributed in space (ortsverteilt) and independent of time (zeitversetzt).The focus is on computer-"exercises", which has certain implications on the technical setup: the back channel is very important and the teacher's presentation as well as the student's computer screens is visible on both places. Different modes of use are possible. Two rooms at different campuses of the university are connected by the universities internal high-bandwidth, but non-reserved, TCP/IP-connection. Each one is equipped with two data projectors, where one is used as white board mirroring the teacher's or a student's computer screen, while the other shows the teacher and the opposite room inhabitants. Each room has its own control computer that is also used for video or audio streaming. By the use of wireless connected laptops a comfortable degree of freedom for teachers and students is achieved. Despite this, we use low-cost hardware and standard software wherever possible. The audio-taped lectures are combined with the screen materials, mostly PowerPoint slides enhanced with QuickTime media, so that lectures as well as other stored materials are accessible via Internet. After more than two years of thorough experiments the installation has reached now a state where it is relatively stable, so that it is transferred now for regular use in our teaching activities. (pp. 149-153)

Keywords: e-Learning, tele-teaching, multimedia in teaching and learning

There is a growing expectation from distance learners that their learning and teaching environment will be on-line. Limitations on bandwidth to the home has so far constrained the richness of such environments. A hybrid solution to this problem combines the immediacy of the Internet with the versatility of DVD Technology. This versatility allows the disc-based material to be integrated with web based material or used off-line as a self-contained learning environment. All content which is not computer dependant such as audio-visual material, can be viewed with a domestic DVD player from the same DVD disc. (pp. 155-158)

Keywords: web based learning, DVD-ROM, connected DVD, distance education

Erkki Sutinen
ITN - Institutionen for Teknikoch Naturvetenskap, Campus Norrkoping, Linkopings Universitet, 60174 Norrkoping, Sweden Phone: $+$46 11 363 338, Fax: $+$46 11 36 32 70 E-mail: erksu@itn.liu.se

Heikki Topi
Dept. of Computer Information Systems, 403 Smith Technology Center, Bentley College, 175 Forest Street, Waltham, MA 02452, U.S.A. Phone: $+$1-781-891-2799, Fax: $+$1 781 891 2949 E-mail: htopi@bentley.edu

Marko Turpeinen
Alma Media Corporation, Etelaesplanadi 14, P.O. Box 140, FIN-00101 Helsinki, Finland Phone: $+$358 9 50771, Fax: $+$358 9 507 8555 E-mail: Marko.Turpeinen@almamedia.fi

As part of the Virtual University of Finland, the Connet framework offers undergraduate courses in Cognitive Science. The studies are mainly organized as web-based courses or collaborative student projects. In the basic studies component, a student completes four one credit methodology courses and chooses a related assignment worth three credits for one of them. One of the methodology courses is entitled Networks in Learning Organization. It will be delivered entirely on the web, and it also will serve as a pilot course to help design other methodology courses. This paper will first briefly discuss the theoretical foundations of learning organizations and organizational learning. Then, we will review the role of networks as the technological foundation of a learning organization and continue by discussing the use of educational technology to support organizational learning and learn about it. Finally, we will describe the structure and the methods of the course and present topics that form the starting point for the discourse within the course. (pp. 159-164)

Keywords: learning organizations, organizational learning, communication networks, virtual university

Sutinen Erkki
University of Joensuu, Department of Computer Science, P.O.Box 111, FIN-80101, Joensuu, Finland Phone: +385 13 251 7934, Fax: +385 13 251 7955 erkki.sutinen@cs.joensuu.fi

As part of the Finnish Virtual University, the universities in the east of Finland offer high school students an opportunity to obtain their first 15 university credits of Computer Science over the Web. At the University of Joensuu, the courses consist of three parts: General Introduction to Computers (three credits), Introduction to Computer Science (five credits), and Programming (seven credits). Instruction is almost entirely given over the Web. The students follow a schedule given in the web site, learn the related chapters from their textbooks, and return the exercises by strict deadlines.
The students live as far as a hundred kilometers away from the university, and their local high schools have not been able to hire any qualified programming teachers. We found a solution to this problem by organizing on-line teachers at the university to answer students' questions, and assigning tutors, who had hardly any experience in programming, to encourage the students at the local schools. To intensify the learning outcomes, we are planning to use three different learning tools in the web-based course environment: Excel, Jeliot and BlueJ. Each of them can be used for understanding a given program visually. In particular, the environments serve as virtual laboratories for real problems: the students can study their own programs.
At the University of Joensuu, the course started in August 2000. Out of the 80 enrolled students, more than 65 were active after the first three months. Altogether, the course will last for 16 months. Students' activity and commitment to their studies indicate that the approach chosen to teach programming has proved to be efficient. (pp.165-171)

Keywords: intoductory programming, virtual university, high school, distance education

Jan Rychlík
University of West Bohemia, Univerzitní 8, Plzeò, Èeská Republika Phone: +420 19 7421 417, Fax: +420 19 7421 419
rychlik@civ.zcu.cz

Petr Jiroušek
University of West Bohemia, Univerzitní 8, Plzeò, Èeská republika Phone: +420 19 7421 417, Fax: +420 19 7421 419
petr@civ.zcu.cz

The U.W.B. has developed an information and database system, supporting the internal Credit Accumulation and Transfer System (CATS). The system primarily supports an on-line student registration to courses within the framework of the existing timetable, and further provides a support for designing and filing study programmes, timetables, student records, agenda of admission and alumni etc. We give a survey of basic features of the system and of the history of its development and we present basic rules of the internal CATS that have to be followed by every institution that wants to adopt the system. The system has been already installed at 5 further Universities in the Czech Republic. (pp. 173-176)

Keywords: information systems, prototyping life cycle, credit transfer system, database, study agenda

This paper presents the French universities national data warehouse project, which was begun in 1999. The Source databases are the administrative systems, and the target data base, or, data warehouse, is designed to be the executive information system of the institution. Pilot universities in Amiens, Paris, Rennes, Strasbourg, and Versailles are presently testing the prototype. A first release will be done in 2002 for other interested institutions. (pp. 177-181)

Keywords: data warehouse, executive information system

Building a data warehouse for a large decentralized university such as the University of Ljubljana is an attractive challenge, but also a risky and demanding task. Experience has shown that projects attempting to integrate data are especially vulnerable to data quality issues. Therefore, before embarking on a data warehouse initiative a thorough quality assessment of the source data is necessary. We describe how the assessment criteria based on the Total Quality data Management Methodology were adapted to our specific needs and used to determine the quality of student records data at two member institutions, viz. the Faculty of Computer and Information Science, and the Faculty of Electrical Engineering. The most important results of the assessment are described and proposals are given for further activities. The assessment has shown that the student records data at the Faculty of Computer and Information Science and Faculty of Electrical Engineering are good enough to be used as source for the global warehouse at the university level after some data cleansing takes place. Additionally, special attention must be devoted to the integration of such data that are replicated at many individual departments (viz. employees, subjects taught, and students). Therefore, we propose that a unique coding scheme for all employees, students, and subjects taught be defined in the first step of the data warehouse design, and an ongoing data quality management process is established clearly defining the roles and responsibilities of all personnel involved. (pp. 183-188)

Keywords: data warehouse, information quality, total quality management, data quality assessment

We describe a high performance/low price "computer cluster" named Beowulf Cluster. This kind of device was initially developed by T. Sterling and D. Becker (N.A.S.A) and it is a kind of cluster built primarily out of commodity hardware components, running an OSS (Open Source Software) operating system like Linux or FreeBSD, interconnected by a private high-speed network, dedicated to running high-performance computing tasks. We will show several advantages of such a device, among them we can mention very high performance-price ratio, easy scalability, recycling possibilities of the hardware components and guarantee of usability/upgradeability in the medium and long-term future. All these advantages make it specially suitable for the university environment and, thus, we make a description about the implementation of a Beowulf Cluster using commodity equipment dedicated to run high-performance computing tasks at our university focusing on the different areas of application of this device that range from production of high quality multimedia content to applications in numerical simulation in engineering. (pp. 189-193)

Keywords: Cluster, OSS, Linux, High performance computing, computer commodities.

As multimedia applications are becoming more and more widespread, there is a need for video data to be transmitted over IP as well as ATM networks. While ATM with its Quality of Service features is able to provide adequate transmission guarantees for the strong timing and bandwidth constraints of video data, the transfer of video over IP networks is an issue wherever ATM is not available and applications are used that can tolerate longer delays and occasional impairments. The study evaluates a codec for teleconferencing and teleteaching applications over an IP network. A direct comparison is made to a MJPEG codec for similar applications over ATM with empirical measurements in a simple testbed. The main focus lies on the Quality of Service parameters delay, jitter and subjective picture quality. Network overload situations and realistic network behavior are simulated and their impact on picture quality is evaluated. (pp. 195-200)

Keywords: QoS, ATM, IP, Video Transmissions

With today's widespread availability of networked multimedia potentials embedded in an infrastructure of qualitative superior kind the distribution of professionally styled multimedia streams has fallen in the realm of possibility. This paper presents a prototypic environment - both model and runtime system - for processing composite media streams variably composed of multimedia data objects. The system consists of an intelligent media database, a Web-authoring tool, a time directed presentation stream and is based on a hypermedia data model of reusable object components. The plug-in free runtime system is designed as a pure JAVA implementation. Further educational applications of our architecture are presented, as well. (pp. 201-209)

Keywords: Synchronized Media, Hypermedia Modelling, Multimedia Database, Web-Authoring

Janne Kanner and Mika Kivilompolo
CSC - Scientific Computing Ltd., P.O. box 405, FIN - 02101 Espoo, Finland, janne.kanner@csc.fi, mika.kivilompolo@csc.fi

The FEIDHE project aims at specifying what it will take to implement a public key infrastructure (PKI) based identification system with smart cards in Finnish higher education. Main drivers of the project are data security, flexible use of electronic resources over the network and the national PKI initiative FINEID (Finnish Electronic Identification). The project is looking for a way to manage identification and authentication when accessing electronic resources and services over networks. (pp. 211-216)

Keywords: Security, PKI, smart cards, authentication

The University of Paisley, located in the South-West of Scotland operates across several campuses and has experienced many changes. These changes include the reorganization of academic structures, and a student population becoming more diverse. Linking all the campuses is a Wide Area Network which has been structured into four distinct layers for security purposes. The network infrastructure has been developed using a framework model to support the delivery of information systems services and intranet developments. These developments incorporate both access and security requirements. Initially, delivery and operation of various services was centralized, but gradually this has been changing with a move to more devolved operations as well as additional services coming on stream. This paper presents an example application that demonstrates the change in delivery of a service, partly as a response to organizational and resource issues. It also demonstrates the application of an information systems model allied to a technical model to help focus on requirements. (pp. 217-222)

Keywords: application, model, network, security

James M. Boyle
Technology Development Division, Argonne National Laboratory, Argonne, IL 60439, USA, boyle@anl.gov

The problem of allocating a finite number of hardware registers to evaluate arbitrarily complex arithmetic expressions arises in the implementation of programming language compilers. Traditionally, register allocation has been implemented by using graph-theoretic algorithms. In contrast, we discuss an approach based on direct algebraic manipulation of the expressions for which registers are to be allocated. These manipulations employ simple identities and canonical forms from "program algebra". The algebraic approach admits a straightforward implementation of the required identities as rewrite-rule program transformations. The use of canonical forms for the intermediate expressions makes it possible to apply the transformations automatically. The approach we describe offers a number of advantages. The algebraic approach is easy to understand, because expressions are manipulated directly instead of being converted to graphs. Moreover, the algebraic approach can implement efficient register-allocation strategies without sacrificing this understandability, through the use of suitably chosen intermediate canonical forms. Finally, the correctness of the algebraic approach is easy to prove, because the program transformations that perform the manipulations are based on identities from program algebra. (pp. 223-233)

Keywords: register allocation, code generation, program transformation, compilers, programming languages

We consider main properties of a neural field whose state is determined by a vector of some topological space (such as Banach or Hilbert ones). Dynamics of the field (time evolution of its state) is associated with information processing and mental phenomena. We formulate the learning problem for neural fields and offer several solutions that are generalizations of learning algorithms proposed for neural networks before. The state vector of a neural field is represented in a form like in quantum theories, which gives a clue to a kind of supersymmetry, viz symmetry between bosonic and fermionic modes of excitation of the neural field. An evolution equation for a field function is suggested. A minimal architecture of a cognitive system is proposed which comprises perceptual, lexical and semantic subsystems. It is suggested to treat the meaning of a piece of information as a code associated with a settled field function produced by a semantic neural network. (pp. 235-246)

Keywords: information encoding, information processing, neural field, neural network, mental phenomena, meaning of information, cognitive system, learning rule, neural-quantum similarity, supersymmetry, evolution equation

Mobile agents can be regarded as software components which can move from host to host to perform computations. Research over the past half-decade has found the mobile agent paradigm to be useful for many applications. This paper aims to show the broad applicability of mobile agents for enterprise distributed applications. It first provides an overview of mobile agent usage in three types of enterprise applications: intra-organizational, inter-organizational and customer-to-business, with focus on data management, distributed parallel processing, computer-supported collaborative work, virtual enterprises, and customer-facing systems. Then, we discuss issues and future work. (pp. 247-260)

Keywords: mobile agents, enterprise, distributed applications

Mario Paz
Dept of Civil Engineering, University of Louisville, Louisville, Kentucky USA

Russ Purvis
Department of Management, Clemson University, Clemson, South Carolina USA

We match a template depicting a "bull flag" 60-day price behavior to closing prices of the New York Stock Exchange Composite Index to detect buying opportunities at a 20 trading day horizon. The results of the experiment indicate that the technique is capable of achieving results which are superior to those attained by random choice. Statistical results are significant. The paper constitutes evidence that the stock markets are not efficient. (pp. 261-269)

Keywords: Stock market forecasting, pattern recognition, heuristics, financial decision support, efficient markets hypothesis, technical analysis

A digital neural network architecture is presented which is based on three-dimensional massively parallel opto-electronic circuits. A suitable optical interconnect system and the structure of the required electronic circuits is specified. For this system general formulas for the performance of such a neural network architecture are determined. A parameter study using current technological limitations and timing values from electronic implementation is carried out. Based on this analysis it is shown that this novel type of neuro-architecture that is using 3D massively parallel opto-electronic circuits shows performance rates of up to one magnitude higher than systems using digital neurochips based on fully electronic implementation. (pp. 271-278)

Keywords: digital neural networks, optoelectronics, hardware architecture

The versality of the compact disc (CD) has quickly become apparent to manufacturers and users alike. Exceeding the expectations of even its most ardent supporters, the CD holographic disc storage system has become one of the most successful consumer electronics products ever introduced. The phenomenal success of the audio CD on the eager worldwide marketplace has encouraged rapid development of CD technology and spawned entirely new high tech applications for the dimpled disc. The Mini Disc (MD), for instance, occupies about one--fourth the area of the standard CD--Digital Audio (CD--DA) format yet provides an identical playing time through efficient data reduction. The essence of digital audio lies in its numerical basis. It is the aim of the present paper to elaborate the mathematical principles underlying the audio CD as far as they are concerned to the format's electronic and holographic principles. (pp. 279-291)

Keywords: IT, CD