Projects of the Department of Computer Science 1994-98
 

 
 
University of Helsinki Department of Computer Science  
University of Helsinki
Department of Computer Science

Projects of the Department of Computer Science 1994-98

The research at the department has evolved over the years similarly to the international research trends in computer science. Early work in numerical analysis in the 1960's made room for work in programming languages and compilers in the 1970's. Since then the research has diversified and its volume has increased.

The main sources of research funding are the Academy of Finland, the Technology Development Centre of Finland (TEKES), the Ministery of Education and the European Union (EU) research programmes. All projects funded by TEKES also have partial funding by industrial partners.

The Department participates in the following two graduate schools that fund the research of some PhD students: The Helsinki Graduate School in Computer Science and Engineering (HeCSe; a joint school with the Helsinki University of Technology); the Graduate School in Computational Biology, Bioinformatics and Biometry (ComBi; a joint school with the University of Turku and the Center for Scientific Computing of Finland. The school is coordintaed by the Department and directed by Prof. Esko Ukkonen).

The department has three informal sections that are used in the planning of the curricula and in administration. The division is not strict, and several research projects span two sections. The sections cover roughly the following subject areas:

  1. General Computer Science (Prof. Esko Ukkonen, Prof. Henry Tirri, Prof. Matti Mäkelä): algorithms and data structures, computational complexity, computational geometry, machine learning, Bayesian networks, neural networks, computer graphics, numerical and symbolic computation, computational biology, geoinformatics, computationally intensive tasks, computer-aided instruction, computers in education
  2. Computer Software (Prof. Jukka Paakki, Prof. Kimmo Raatikainen, Prof. emer. Martti Tienari): programming languages, compilers, formal specification and verification, software engineering, distributed systems, computer networks, operating systems, performance evaluation
  3. Information Systems (Prof. Heikki Mannila, Prof. Seppo Sippu): databases, human-computer interfaces, computer supported co-operative work, information system design methodology, design of databases, text databases, object-oriented databases, logic databases, database structures and algorithms, document management, data mining and knowledge discovery, management of spatial data (GIS).
In the following, the research activities of each section of the department are reviewed.

General Computer Science

The main research areas in the section of general computer science are algorithms and data structures, machine learning, probabilistic reasoning, computations by complex dynamic systems (cellular automata and genetic algorithms) and computational biology. Algorithms, Data Structures and Complexity (Academy of Finland, 1983-, Ukkonen) is the area with the longest tradition. The work on string matching algorithms (Ukkonen, Tarhio) has been particularly successful. Theoretical work has often been conducted within the framework of systems research providing practical motivation for the problems studied. Currently, special emphasis is given to the research on algorithmic problems in computational biology and bioinformatics. A project on Algorithmic Methods of Biocomputing and Data Analysis (Academy of Finland, 1999-, Ukkonen) has just started.

The Complex Systems Computation Group (CoSCo, Tirri) studies computational issues related to complex systems focusing on prediction and model selection issues. Current work of the CoSCo group is concentrated on theory and applications of Bayesian (belief) networks, and related probabilistic model families, such as finite mixture models. The Computationally Intelligent Hybrid-Paradigm Environments project (HYPE/TEKES, 1995-98) studied hybrid systems integrating different modules such as neural networks, probabilistic models and genetic algorithms all aiming at solving a single problem. The general objective of the Computational Intelligence Techniques for Nonlinear Modelling in Social Sciences (NONE/Academy of Finland, 1998-99) project is to develop theoretically sound computational intelligence techniques for nonlinear modeling of data, and methodologies for applying them in the domain of educational data. The main objective of the PROMISE project (TEKES, 1998-99) is to study methods for applying probabilistic modeling techniques (Bayesian networks, finite mixture models) and stochastic optimization methods (simulated annealing, genetic algorithms) in constructing adaptive and intelligent systems.

The Machine Learning Group (Academy of Finland, 1994-, Mannila, Ukkonen) has studied different machine learning models and the complexity of learning tasks within these models as well as their applications, e.g., in biological sequence analysis and process industry. The aim of Neural and Computational Learning (NeuroCOLT Working Group/EU, 1994-2000, 10 sites, Ukkonen) is to develop a fundamental understanding of learning and of when and how it can be implemented algorithmically. Machine Learning Methods in Hydrological Modeling and Optimization (Academy of Finland, 1994-99, Ukkonen) applies machine learning methods in hydrological modeling (a joint project with the Finnish Environment Institute).

The Animation Aided Problem Solving (AAPS/Ministery of Education 1996-98, Tarhio) has studied program visualization, teaching algorithms by means of animation, and computer-supported concept mapping. The group has developed a Web-based system for fast generation of algorithm animations. The Survey of Information Technology in Human Services in Finland (SosKart/STAKES, 1998-99, Mäkelä) analyses and evaluates the state and the prospects of the information technology applications currently used in human services in Finland.

Computer Software

Our computer software research can be subdivided into two main areas: distributed systems and telecommunication software (Raatikainen, Tienari, Alanko) and programming languages and software engineering (Paakki). In some projects these two areas are intertwined.

The Modelling of Concurrency (MOCO/Academy of Finland, 1990-, Tienari, Kaivola) studies formal specification and verification of distributed systems, developing and using theories and software tools based on process algebras and temporal logics. The Open Distributed Computing Environments (ODCE, 1992-, Tienari, Raatikainen) group concentrates on open architecture models and platforms. First, the DRYAD project (TEKES, 1992-1996, Tienari) studied middleware support for federation of sovereign systems. Conceptual results were contributed to the Open Distributed Processing reference model standardized by ISO/ITU; experimental results included a prototype trader. A newer ODCE project is the CORBA-Based Framework for Telecommunications project (CORBA-FORTE/TEKES, 1998-1999, Tienari, Raatikainen) focuses on the performance and usability of the CORBA architecture in telecommunications systems.

Mobile Computing (MOWGLI/TEKES, 1993-99, Tienari, Raatikainen, Alanko) studies, designs and tests new data communication architectures for GSM-based mobile data services. The Service Machine Development for an Open Long-term Mobile and Fixed Network Environment project (DOLMEN/EU, 1995-98, 12 partners, Raatikainen) demonstrates, assesses and promotes a Service Architecture (called Open Service Architecture for a Mixed fixed and mobile environment - OSAM) that meets the requirements of open provision of communication services over both fixed and mobile heterogeneous and multi-provider telecommunications networks. The Adaption Agents for Nomadic Users project (MONADS/TEKES, 1998-, Raatikainen) examines adaptive agents for nomadic users. Mobile Intelligent Agents in Accounting, Charging and Personal Mobility Support (MONTAGE/EU, 1998-, 5 partners, Raatikainen) aims to research, evaluate and assess the impact of agent technology to the telecommunications world. A new project, Promoting Interoperability for Multimedia services in Europe (Prime/EU, 1999-2000, 8 partners, Raatikainen) has just started.

The research project Database Architecture For Intelligent Networks (Darfin/TEKES, 1993-95, Raatikainen), examined database architectures that can fulfill the requirements of Intelligent Networks (IN) and Telecommunication Management Networks (TMN). The research project Real-Time Object-Based Database Architecture for Intelligent Networks (RODAIN, 1996-, Raatikainen) continues the work done in the Darfin project. In the project the research group has designed and specified a real-time object-oriented database architecture for Intelligent Networks and implemented a simple prototype.

The worldwide development of the LINUX operating system was initiated and coordinated at our departent by Linus Torvads 1991-97. The work with Linux still continues here. The objective of the department in the High Performance Gigabit I2O Networking Software project (HPGIN/EU, 1998-2000, 3 partners, Raatikainen, Tienari) is to implement I2O extensions to the Linux standard network operating system and to add support for I2O compliant gigabit networking adapters.

The A Channel into Object-Oriented Protocol Design (Kannel/Academy of Finland, Paakki) project developed Kannel, an integrated language for the design and implementation of communication protocols. The Computer-Aided Software Maintenance (HyperSoft/TEKES, 1994-96, Paakki) project developed a tool supporting typical software maintenance tasks such as debugging, side-effect analysis, and regression testing. In another project, A Framework Editor for Java (FRED/TEKES, 1997-99, Paakki) the group developed a prototype CASE tool for the development of reusable application frameworks founded on design patterns. Object-based software architectures (Academy of Finland, 1999-2001, Paakki) is a new project studying software architectures.

The ESPRIT A Methodology-Based Workbench for KBS Life Cycle Support (VITAL/EU, 1990-95, 9 partners, Mannila, Tirri) designed and implemented a methodology-based workbench for KBS life cycle support.

Information Systems

In information systems the largest research project has concentrated on data mining (Mannila, Verkamo), also known as knowledge discovery in databases. The research is done in cooperation with the machine learning group, with statisticians, and with the appliers of the work. The research started in late 1980's in the context of developing tools for inferring integrity constraints from databases. Recent research results include efficient data mining methods for database re-engineering, methods for finding recurrent episodes within event sequences, and development of automatic tools for the simulation of complex statistical models. The Data mining in telecommunications project (TASA/TEKES, 1994-87, Mannila) has developed several new methods for extracting interesting information from large data sets. The From Data to Knowledge (FDK/Academy of Finland, 1996-99, Mannila, Toivonen, Ukkonen, Verkamo,) is a large umbrella project developing methods for knowledge discovery from large masses of data. The project combines and develops methods in computer science and statistics, and the methods are applied to epidemiology, biotechnology, environmental research and archaelogy. Knowledge Extraction for Statistical Offices (KESO/EU, 1995-98, 8 partners, Mannila, Verkamo) developed tools for knowledge discovery from large statistical data sets.

The Document Management (DocMan, Mannila, Kilpeläinen) research group studies the theory and application of structured documents. Former research projects include the sgrep project (1995) which designed and implemented a search tool for structured documents. Structured and Intelligent Documents (SID/TEKES 1995-98, Kilpeläinen) was a project within the DocMan group that studied and developed methods and tools for the realization of ''intelligent documents'' which would easily adapt to the needs of different users. A central goal application was document assembly, by which we mean computer supported compilation of new documents from existing text sources. The Intelligent Management Information Systems (ÄLYJO/TEKES 1997-99, Mannila) project studies information retrieval, computer-supported cooperative work and interactive communication in management information systems.

The Transaction Management Support for Cooperative Applications (TRANSCOOP/EU, 1995-97, 3 partners, Tirri) project studied design of cooperative systems including the description and formal specification of cooperative activities.