Monthly Archives: May 2007

Aeronautical Data Networks: toward an all IP Solution

Betim Çiço, Lendina Smaja

Abstract. This paper gives an overview of communication systems and data applications used by civil aviation authorities for processing and exchange of flight data, radar data, metrological data and aeronautical in formation. Data networks in ground applications are treated in detail. By arguing several factors that has conditioned the evolution of aeronautical data networks, the necessity to adopt new technology is highlighted even though replacing legacy systems in safety critical systems proves to be very complex. Finally, he Aeronautical Telecommunication Network (ATN), that is an International Civil Aviation Organization (ICAO) undertaken initiative is used as reference example. ATN standards have been discussed based on lnternet Protocol Suite, since ATN implementation will be based on TCP/IP infrastructure.

Keywords.  data  communication,  voice  communication,  air  traffic  applications,  ATN,  lPv4, lPv6, ICAO standards.

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Towards combining rule-based and statistical part of speech tagging in agglutinative languages

Levent Altunyurt, Zihni Orhan, Tunga Gdngdr

Abstract:  We present a composite part of speech tagger for Turkish which combines the rule- based and statistical approaches. The tagger makes use of word frequencies and n-gram statistics from a corpus. We use the output of a morphological analyzer in order to get more accurate results and also to eliminate the sparse data problem. In addition, we employ  a  heuristics  about  the position of words in the sentences. Although the experiments have been performed on a very small corpus, the results have shown that the use of a composite approach and heuristics improves the accuracy of the tagger.

Keywords: agglutinative language, part of speech tagger, rule-based and statistical method

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Chessboard Application of 6 Axes Robot Arm by using Inverse Kinematics Equations

Baki Koyuncu, Mehmet Gtizel

Abstract: The inverse kinematics equations of 6 axes robot arm are used to move the end- effectors of a robot arm for target positioning. A chessboard example is presented as a robot arm application. A pc based software package is developed to control and simulate the Lynx 6 Robot arm for the chessboard application by using inverse kinematics  equations. Robot arm manipulated the magnetic chess pieces with an electromagnetic attachment by catching and dropping  them at the predetermined positions on the chess board.

Keywords: 6 axes robot arm, inverse kinematics, chessboard, electromagnets

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Model based Requirements Engineering for computer aided engineering systems in the Automotive Sector

Daniel Motus, Bjdrn Sommer, Lilli Schulz, Georg Paul

Abstract: The ongoing globalization and the permanent changing economical and technical environment for the  automotive  industries  demand  efficient  integrated  business  processes, methods and computer aided engineering systems.  Requirements  of  automotive  information systems therefore have to be described in the early  development  phase  of  each project,  since errors can be eliminated in later phases only with high expenditure of money and time. In addition crucial influence on the development of workflows and processes  can  be  exerted  in  the  early phase.  The  paper  describes  exemplarily  the  model-based  requirements  engineering  of   an automotive assembly planning information system  based  on  event-controlled  process  chains (EPC). The working plan as a description of assembly processes is to form the core of this system.

Key words: automotive, requirements engineering

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Problems of Parallel Sorting on Multicomputer Platform

Plamenka Borovska, Milena Lazarova

Abstract: The paper explores the efficiency of parallel sorting algorithms on multicomputer
platform. Parallel message passing bucket sort algorithm and parallel multithreading and hybrid
heap sort algorithms are investigated. Suggested parallel computational models are based on the
parallel programming paradigm “manager worker”. Speedup and efficiency as well as scalability in
respect to the size of the multicomputer and the size of the parallel workload and their impact on
the performance of the parallel system have been estimated on the basis of experimental results.

Key words: bucket sort, efficiency and speedup, heap sort, message passing, parallel sorting,
parallel programming paradigm, performance analysis, scalability

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Data Validation in Web Applications

Veska Gancheva

Abstract:The paper systematize common used strategies and approaches to data validation.
Some existing approaches are compare and their advantages and weakness are discusses.
Summaries and conclusions are making. The purpose is to make an attempt to suggest a new
approach for fully implementation of a data validation in order to realize a platform independent
easily extended and accessible modification system. Data validation approach separates the
implementation of common data validation reasoning code from the business rules and criteria data
used to validate user input. This approach provides a powerful and flexible way for application
developers to specify data validation in a manner that is secure and easy to manage, while
decoupling validation rules from the server-side business logic implementation.

Key words: Web based applications,  data validation, XML.

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Synthesis and studying topological structures of space switches for ATM computer networks

Petko Stoyanov

Abstract:The paper presents base type of ATM (Asynchronous Transfer Mode) space switches
The paper also presents some basic elements of the Generalized Nets theory – a formal
description of a transition, a definition of a generalized net and a set of functions determining its
operation. A generalized net switch model are designed including static structure, possible steps and
predicates for their realization. The paper also presents an approach for formal description new
topologies. The author studies the behavior of the models in all possible non-colliding situations and
ascertains its applicability.

Key words: ATM networks, ATM switches,  Generalized Nets.

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Database search improvement using fuzzy variables

Daniela Gotseva

Abstract. The report offers one method that gives the possibility to improve database (DB) SELECT capabilities using fuzzy variables into SQL queries. Different examples  and  fuzzy inference models are investigated to prove searching improvement. Adding  fuzzy  variables made DB query creation for the user easy and intuitive, because of using categories closer to him.

Key words.  database search, fuzzy variables, SQL

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