Program kolokvií s abstrakty pro semestr Jaro 1997

4. 3. 1997: Jiri Wiedermann, CSAV Praha; Cognitive computing - getting started
11. 3. 1997: Horst Reichl, TU Dresden; C0-induction
18. 3. 1997: Karel Pala, Faculty of Informatics, MU Brno; Morfologicky analyzator pro cestinu (korpusova aplikace)
25. 3. 1997: Michael Noelle, TU Hamburg-Harburg; Data distribution concepts for data parallel implementations; Abstract: Parallel distributed memory systems are increasingly used as scientific computing platforms since they provide high performance at relatively low hardware costs. The broad use of these systems depends mainly on the availability of software and the ease to generate solutions for new applications. For the exploitation of the high performance potential of distributed memory multiprocessor systems two programming paradigms, functional and data parallelism, are in the main focus of investigation and are widely used. In the talk data distributions concepts will be presented that offer a convenient, scalable and, portable facility to express data parallelism for a wide range of parallel systems and programming environments.
The impact of data distributions on parallel implementations may be described by three factors. Load balancing addresses the task of dividing the workload evenly among the processors. The minimization of communication requires to optimize the amount and the distance of data exchange between different processors at runtime. By overlapping computation and communication it is often possible to hide the communication latencies.
Data distributions suitable for parallel image processing and those defined by some of todays more popular parallel languages (HPF) and libraries (ScaLAPACK) will be analysed. The impact flexible data distributions have on parallel implementations are discussed.
2. 4. 1997: Petr Hajek, UIVP CSAV Praha; Deduktivni systemy fuzzy logiky; Abstract: Budou presentovany axiomaticke systemy nekonecnehodnotovych vyrokovych a predikatovych logik sloucicich jako formalni systemy fuzzy logiky. Zakladem je pojem spojite t-normy jakzto semantika fuzzy konjunkce. Predvedu jednak zakladni fuzzy logiku, korektni pro vsechny logiky dane t-normami, jednak tri specialni logiky dane tremi zakladnimi t-normami (Lukasiewiczova, Godelova a produktova). Budou prodiskutovany otazky uplne axiomatizovatelnosti, a vypocetni a aritmeticke slozitosti. V zaveru (nebo v uvodu) proberu nektere casto se opakujici otazky a pochybnosti tykajici se logik vagnosti.
8. 4. 1997: Georg Gottlob, TU Vienna; Revising and updating logical knowledge bases; Abstract: When knowledge is represented in logic, then a knowledge base corresponds to a logical theory. Since our knowledge about the world changes continuously, such knowledge bases must be revised and/or updated. This talk gives a survey on various methods that have been developed in Computer Science (in the fields of Databases and AI) for incorporating new information into a knowledge base even in case of inconsistencies. A taxonomy of the various approaches will be given, and three approaches will be discussed in detail. In particular, we will explain the difference between "revision" and "update". The complexity of knowledge base updates and revisions will also be discussed.
15. 4. 1997: Keith G. Jeffery, SERC, RAL, Oxon, UK; Databases and the web; Abstract: WWW is the mos significant information technology yet known. Its impact is enormous - both onprofessional and personal life. However, the web has been developed with little or no reference to theoretical computer science or best-practice engineering . This seminar discusses the end-user requirements, the features of the web and of database systems and discusses how the best features may be combined to provide acceptably engineered information systems.
22. 4. 1997: Frantisek Plasil, MFF KU Praha; Corba Architecture - Basic Principles; Abstract: The main intention of this talk is to provide the audience with the fundamental knowledge of Common Object Request Broker Architecture (CORBA) with an emphasis upon one of its basic components: CORBA Object Services (COSS). The brief history of CORBA development from CORBA 1.1 to CORBA 2.0 supporing interoperability features is given. Key concepts specified in CORBA 1.1 and CORBA 2.0 are reviewed: Interface Description Languge (IDL), client stub, server skeleton, Basic Object Adapter (BOA), Internet Inter-ORB Protocol (IIOP), request-level bridging and inline bridging. Based on OMG series of Requests for Proposal (RFP), the evolution of enlarging the family of CORBA Object Services is analyzed and commented.
29. 4. 1997: Jan Hajic, KU Praha; Lingvisticke anotace Ceskeho narodniho korpusu; Abstract: Cesky narodni korpus vznika jako kolekce ceskych psanych textu z nejruznejsich oblasti (zurnalistika, beletrie, dokumentaristika, efemera atd.). Tato kolekce je v zasade obrazem puvodniho textu, byt explicitne oznackovaneho (anotovaneho) na urovni slov, vet, odstavcu a dokumentu. Pro ucely lingvistickeho vyzkumu i aplikaci v oblasti zpracovani prirozeneho jazyka je vsak dulezite mit k dispozici co nejvice textu anotovanych nejen "technicky", ale i "lingvisticky". V projektu "Formalni reprezentace jazykovych struktur" pracujeme na trech urovnich takove anotace: morfologicke, analyticke a tektogramaticke. Morfologicka uroven pracuje s morfologickymi kategoriemi, jako napr. pad, cislo, rod, cas apod., avsak struktura vety se nezavadi -- jedna se o linearni posloupnost slov a jejich atributu. Na analyticke urovni, ktera se nejvice blizi povrchove syntaxi, jak ji zname z obvyklych gramatik, se zavadi zavislostni struktura a tzv. analyticke funkce (podmet, predikat, predmet, atribut, atd.). Pritom pocet uzlu zavislostniho stromu stale odpovida poctu slov ve vete. Na nejvyssi, tektogramaticke urovni se pracuje jiz s pojmy jazykoveho vyznamu, a zachycuji se i jevy na analyticke urovni nepritomne (elipsy, reference, aktualni cleneni). Vysledkem celeho projektu bude nejmene 0.5 mil. slov anotovanych na analyticke urovni, a mensi vzorek anotovany na tektogramaticke rovine.
6. 5. 1997: Bruno Buchberger, RISK Linz; The Theorema Projest: An overview; Abstract: The Theorema Project aims at integrating proving support into computer algebra systems. The emphasis is on proof generation for routine parts of proofs, structured proof presentation in natural language, and smooth interaction with the existing solving and computing facilities of computer algebra systems. Our present system frame is Mathematica 3.0.
We will first give an overview on the Theorema Project and then present more details about the following aspects of the system:
* A predicate logic prover that imitates the proof style of humans (in particular the proof style of the authors).
* A couple of of special provers for various "areas" of mathematics (at present, for equalities over natural numbers, lists, and polynomials), where an "area" is defined by a functor that generates the domains in the area. that are currently being developed. The main tool is simplification together with setting up the induction recursively over the universally quantified variables.
* Automatic generation of knowledge bases by using the information contained in the functors.
* Stuctured proof presentation in (technical) natural language by using the nested cells feature of Mathematica.
* Theory generation versus theorem proving.
The talk will be illustrated by demos.
13. 5. 1997: Rudolf Freund, TU Wien; Molecular computing with test tubes system; Abstract: Test tube systems were introduced as molecular computing devices used for solving specific practical problems. In test tube systems specific operations are applied to the objects in their components (test tubes) in a distributed and parallel manner; the results of these computations are redistributed according to specific input and/or output filters. Various different theoretical models were investigated, e.g. test tube systems based on the splicing operation as well as test tube systems based on the operations of cutting and recombination. Simple restricted types of filters already allow the generation of any arbitrary recusively enumerable language when using the splicing operation or the operations of cutting and recombination. The same results can be obtained when using no filters but controlled sequences of test tubes instead.
20. 5. 1997: Roland Vollmar, Universitaet Karlsruhe; On some physical restrictions of models of computation; Abstract: We start with the citation of results of Schorr. He introduced two obvious restrictions, namely a finite size of processing elements and a finite speed of signals, and derived bounds for a possible speed-up of parallel devices. As a third restriction we regard the energy consumption resp. the heat dissipation in three-dimensional devices. Different models are considered:
1. Heat dissipation proportional to the surface of the whole cube the machine is incorporated
2. Heat dissipation proportional to the surface of each subcube
3. Addition of wires saving energy costs for the transmission of information
It is shown that there exist problems which can be solved by the different models only in different times.
27. 5. 1997: Petr Stepanek, KU Praha; Deklarativni semantiky logickych programu; Abstract:Pro logicke programy a takzvany ``cisty'' Prolog bylo navrzeno nekolik semantik, ktere vychazeji ze semantiky logiky prvniho radu a zduraznuji deklarativni charakter logickych programu. Patrne nejznamejsi je semantika nejmensich Herbrandovych modelu (Van Emden, Kowalski (1976). Temer stejneho data je semantika nejmensiho termoveho modelu (Clark (1979) znama dnes spise jako C-semantika (Falaschi et al. (1993) a k novejsim patri takzvana S-semantika (Falaschi et al. (1989), ktera dobre popisuje i operacni semantiku logickych programu. Prave problemem vztahu deklarativni a operacni semantiky a dokazovanim castecne spravnosti programu se budeme zabyvati.
10. 6. 1997: Ivan Bruha, McMaster University, Hamilton, Canada; Unknown Attribute Value Processing in Rule-based Inductive Algorithms; Abstract: The genuine inductive machine learning algorithms lack the possibility of processing unknown (missing) attribute values in the input (training as well as testing) databases. The newer versions of such algorithms have incorporated procedures for unknown attribute value processing. The speaker of this talk has designed and implemented an inductive learning algorithm that is able to generate rules using the covering paradigm. He also embedded several routines for unknown attribute value processing. Besides that, the talk will introduce somea new trends in such a processing.
24. 6. 1997: V. A. Vasilenko, Novosibirsk; New achievements in algorithms and software in multidimensioanl and extra-multidimensional and extraMD approximations