NetNews Usenet Archive 1992 #19/NN_1992_19.iso/spool/comp/doc/techrepo/144

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From: [e-mail] (Erkki M{kinen)
Newsgroups: comp.doc.techreports
Subject: Tech. reports from Tampere
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Date: 27 Aug 92 08:11:02 GMT
Organization: University of Tampere, Finland
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UNIVERSITY OF TAMPERE
DEPARTMENT OF COMPUTER SCIENCE
P.O. Box  607
SF-33101  Tampere, Finland


Listed below are some of the latest technical reports of our department.
Single copies are available free of charge. Quantities are limited and
orders will be filled as long as reports are available.

A-1992-3 Kalervo Jarvelin and Timo Niemi, General value conversion and
aggregation operations: definition and integration with relational,
entity-based and deductive data retrieval techniques. July 1992.

Abstract. Existing DBMS's do not support sufficiently advanced information
retrieval in heterogeneous fact database environments. From the user
viewpoint this means that many information needs cannot be satisfied
solely by traditional fact database operations. Transitive computation,
multi-level aggregation and value conversion are frequently needed
together with traditional operations. The possibilities for providing
these capabilities in fact database management systems based on the
relational data model are considered in this paper.
  It is important that the extensions for advanced data retrieval are made
in a uniform way with other relational processing. This means that, on
one hand, new relational operations are developed, and on the other hand,
non-relational operations are integrated with relational processing via
predicates expressed within relational operations. In this paper,
relational algebra is extended by two generalized relational operations:
one for multi-level aggregation and the other for value conversion.
A set of non-relational operations (called deductive operations) for
performing transitive computation is also introduced. User's query
formulation can also be facilitated by providing him with an entity-based
data retrieval operation on a high abstraction level. Such a high-level
entity-based data retrieval operation is also introduced.
  The value conversion operation provides unit of measurement-related
transparency. It supports very versatile conversion (including conversion
of compound attributes) and checks automatically the derivability of
conversion requests. The conversion expressions require minimal information
from the user. The aggregation operation provides aggregation level
transparency. It supports, among others, multiple layered aggregation
levels and hierarchical reclassification of the classification attributes
determining the aggregation levels. In the data aggregation operation,
the functional dependencies between the source and result relations
are connected in a complex way. Both operations are defined in this
paper in an exact way so that they construct both the instances and
the schemas, including functional dependencies, of the result relations.
  Complex data retrieval requires that value conversion, aggreerations
and entity-based data retrieval operation are integrated with traditiontional
operations. In this paper, a query language for advanced information retrieval
consisting of these operations is developed. This language allows the
intermixing of these operations with each other without limiting the
nesting levels. Special attention is paid to the structures, primitives
and principles in terms of which the operations and the query language
can be implemented. All these aspects are defined formally, in a functional
way. In other words, the definition is independent of any programming
language. In addition, the concretization of these aspects in a prototype
system based on Prolog-language and a workstation environment are considered.

A-1992-2 Pertti Jarvinen, On purchasing process of a software package -
         how to teach it? April 1992.
Abstract. In the software industry there is a mass production of packages
for some well-defined purposes, as for text processing, network management,
book-keeping, budgeting etc. Different suppliers produce packages intended
for the similar tasks, and they have both the same and slightly differing
features. The proportional importance of software costs compared with hardware
costs is still increasing.  Hence, selection of the package is a problem
proper where particular knowledge and skills are needed.
  The course on "purchasing of a software package" was organized by
this author in two last springs in the University of Tampere. The course
was intended to students in computer science, but one third of the
participants were from other disciplines, called application sciences. This
fact gave an opportunity to form groups with three students, two from
computer science and one from application sciences. The latter person
played an important role, when a group defined its needs and requirements.
Each group had chance to define its purchasing order, i.e. a software
package to be purchased. Some of the orders were real ones and some others
tentative ones.
  The local software companies allowed the groups to visit and to
negotiate whether the package offered was suitable to the purposes defined
by the group. After collecting the data about candidate packages the student
groups made a comparison and then recommended one of the packages to be
purchased. The groups also considered the ready made contracts and planned
their proposals for changes and amendments to the conventional contracts.
  In this paper I shall describe the pros and cons of the approach
outlined above. I will also give short descriptions of the reports prepared
by the groups, actions to be taken and evaluation of various features of
the course. The students expressed their views on teaching and working
modes, on assessment of learning and on the whole approch. Students'
evaluation was rather positive. This strongly supports the approach
selected. The recommendations for improving our approach are minor and
concern such wishes as changing starting time (8 o'clock) and usage of
teaching material.

A-1992-1 Pertti Jarvinen, Impacts of electronic markets on work.
         January 1992.
Abstract. The domain of electronic markets are increasing in relation
to electronic hierarchies. Hence it is important to analyze possible
impacts of electronic markets on a human being at work. A man can be in
different positions concerning electronic markets: 1. a developer of an
inter-organizational information system (IOS), 2. a user (a seller or a
buyer) of electronic markets,  and 3. an object of markets, i.e. a
specialist whose services are sold on electronic markets.
  First, to construct the IOS a developer has to perform particular
tasks: requirements analysis, design, implementation and thereafter
often also maintenance. Second, a user of electronic markets can do
different things  depending on whether she/he is working in a producer
company, in a distributor firm, in a buyer company, in a network provider
company or in financial services. Third,  services offered by a human
being  on electronic markets should inform potential buyers about her
or his service. On the other hand a buyer must describe which kind of
service she or he needs.firm, in a buyer company, in a network provider
company or in financial services potential buyers about her or his service.
On the other hand a buyer must describe which kind of service she or he
needs.
  In the first position, the idea of the IOS means that the production/
consumption chain is lengthened. The developer of the IOS must master this
chain over two or more organizations. Hence, she or he must be more competent
than nowadays. Concerning the second position, a user of electronic markets,
by definition, will lose social contacts. Her variety to communicate will
diminish, because she or he must use the standardized product/service
description language and/or the information retrieval language at hand. In
the third position, the services offered by a certain expert must be described
as in detail as possible. But this creates a dilemma, if a task can be
described in elementary operations, it could be automated, i.e. the task
is no more necessarily performed by  a human being but by a computer or by
an automaton.

A-1991-9 Pentti Hietala and Jyrki Nummenmaa, MEDUSA - A multimodal database
         user interface with a computer supported learning aid. December
         1991.
Abstract. In this paper we introduce an approach and a corresponding
system combining facilities for natural language processing,
graphical query formulation, and knowledge-based user assistance
under a unified user interface. We discuss also our plans to
iteratively evaluate and improve the system through field evaluation
and data collected by the knowledge-based user assistant. Moreover,
our framework provides a fruitful environment for a more general
comparison and evaluation of different user interaction modalities to
be performed during the iterative evaluation process.

A-1991-4 Esa Helttula, Manipulating disjoint sets: algorithms, testing,
         and animation, June 1991.
Abstract. An analysis and an animation program of algorithms for the union-
find problem is presented. The analysis program can be used to graphically
compare the running times of different algorithms by counting the number
of basic operations and assigning costs for them. It can also be used to
study how the data structures of those algorithms change during execution.
All classic algorithms and some new variations are tested empirically. The
variations and some not optimal algorithms are found to outperform the
classic algorithms in some cases. The animation program gives the user the
possibility to try out different classic union-find algorithms and union-
find-deunion algorithms.

A-1991-3 Pertti Jarvinen, On approaches in information systems research,
         June 1991.
Abstract. The domain of information systems (IS) research is very wide.
The components of an IS and the main stages in the IS life cycle are
different by nature.
There are deterministically behaving hardware and software components.
The same cannot be said about users, i.e. about conscious human beings
having free will. The use and the maintenance of the information system
are not the only stages or processes concerned, but we are also interested
in how to design and implement a new information system. This means that
in addition to discovering a current reality we are also studying how to
construct a new reality. The one and same research approch is not valid
for doing research work concerning different components and processes.
In the recent research of central topics as: causality, determinism, dynamical
systems and theories of acts,  some fundamental similarities and
differences are found. In various taxonomies of IS research there are
different classifications of the legitimated approaches. A reader may
have difficulties to understand whether the difference between two
particular approaches is great or slight, and whether a certain approach
is applicable to a particular purpose. Based on those fundamental
similarities and differences of the central topics our aim is to show a) which
research approaches are in a certain sense "relatives" and which are not,
and b) which research approach is suitable for a particular purpose.
Approaches are broad-mindedly classified to four "families": Firstly, causal
models, statistics, field test and laboratory experiment seem to belong to
the category of theorem-proving causal approaches; secondly, case study,
action research, hermeneutics and phenomenology respectively to the category
of sensitive exploratory approaches catching a current reality. Thirdly,
we identify mathematical approaches containing e.g. formal methods and
cybernetics. Fourthly, there are also constructive approaches suitable
for studying how to construct a new reality. Hopefully these families or
groupings of research approaches might increase the awareness of
the applicability of a particular approach. This is very important in
the IS society emphasizing methodological pluralism. (Presented at the
IRIS'14 in Umea (Sweden), August 12-14,1991.)

A-1990-7 Erkki Makinen, Remarks on the assignment heuristic for drawing
bipartite graphs. August 1990.

A-1988-10 Hannu Kangassalo, COMIC -  A system for conceptual modelling and
information construction, December 1988.

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