Monthly Archives: November 2007

Parallel-in to Serial-out Adapter Synthesis Using FPGA

Valentin Molloy, Plamen Tanov

Abstract: This paper discusses some aspects of the top-down design and implementation problem of a hardware adapter which has parallel inputs and serial output using FPGA (Field Programmable Gate Arrays). An attention is paid on the overall synthesis process, incl. the formal HDL descrip-tion, simulation issues, test-bench generation and implementation. We use Spartan-3E device and Xilinx development kit for preparing design. The paper addresses the main principles of design for such type of adapters, which could be very useful for people going to implement their designs over programmable logic devices and to take an advantage from the various design alternatives.

Keywords: behavioral simulation, PLD, FPGA design, parallel-to-serial adapter, VHDL, test bench

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A Comparison Study of OpenMP Loop Scheduling Methods on a Platform with Hyper-Threading Technology

Subhi Bahudaila

Abstract: The parallel programming standard OpenMP is efficiently applied on shared memory platform. Load-balancing of the iterations among logical processors in a platform with hyper-threading technology is described in this paper. The paper is aimed at statistical comparisons of the OpenMP loop scheduling methods with different parameters: critical path, number of threads and chunk sizes. Intel® Thread Profiler is used in order to read the utilization percentages of the hyper-threading platform. The impact of OpenMP loop scheduling methods on overhead, fully util-ized critical path, and an optimal thread numbers for both software and hardware threads are estimated.

 Keywords: OpenMP Loop Scheduling, Chunk size, Intel® VTune Thread Profiler, Hyperthreading Technology,

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An Evaluation of Structure-Preserving and Query-Biased Summaries in Web Search Tasks

Fatma Canan Pembe, Tunga Güngör

Abstract: Automatic summarization has started to receive increasing attention in recent years due to the increased amount of information available in electronic form. Especially, summarization tech-niques can be very useful in improving the effectiveness of information retrieval on the World Wide Web. However, currently available major search engines such as Google show only a limited ca-pability for summarization. We believe that text summarization with more sophisticated techniques can significantly improve the search experience of users. As a novel approach, we propose a query-biased summarization system which incorporates the structure of documents into the summaries. The system also makes use of natural language processing techniques in the summarization process. The effectiveness of the proposed system has been tested on a task-based evaluation.

Keywords: automatic summarization, human-computer interaction, information retrieval, natural language processing

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Managing Complexity in User Interface Development

Daniel Tiedge, Georg Paul

Abstract: As a result of altering expectations and demands on the software development process the optimization of this process is a matter of great importance. One of the challenges in this area is the management of complexity and the constant adoption regarding the changes in business and technical domains. The objective of this paper is to discuss these challenges in the area of user interface development. For this reason a formal language for describing interactive applica-tions is presented. This language will be used to manage the complexities by clearly separating the application functionality (business domain) from the user interface specifics (technical domain).

Keywords: user interface model, user interface development

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Development of an Image Processing Software

Baki Koyuncu, Erkan Bostancı

Abstract: A menu driven general purpose software package was developed to present various im-age processing tools such as filters and edge detection; image operations such as arithmetic and Boolean operations, Fourier Transform, convolution, correlation and 3D mesh generation. C++ Builder integrated development environment was utilized. All the functions of the IDE were em-ployed to implement a user-friendly menu.

Keywords: Image Processing, Edge Detection, Filters, 3D Mesh Plotting, Image Operations

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Concept Learning and Classification with Prime Implicants Applied to Numerical Domains

Zekie Shevked, Lyudmil Dakovski

Abstract: This paper investigates in extending an algorithm for learning from examples based on prime implicants. The examined algorithm represents sets of positive and negative training instances as logical functions in sum-of-minterms form. The goal is to find a more compact representation of classification function and use it for further prediction of unknown cases. This is accomplished by an innovatory strategy for logical function minimization. The method can be applied in every domain where observations might be described by attributes with nominal values (valued in a finite set). Here we extend this approach to handle numerical data too (valued in a linear interval).

Keywords: Concept Learning, Classification, Prime lmplicant, Numerical Data. 

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A Hardware Dual Watchdog Timer for Increasing the Reliability of Embedded Systems

George Popov

Abstract: The problem of safety has always played a pivotal role in the development of control systems in such application area as embedded systems. The watchdog’s principle is frequently used to guarantee safety for these systems. This paper affects a new concept that utilizes two hardware watchdog timers. There are given new formulas about reliability of watchdog controlled embedded systems.

Keywords: embedded system, contol system, reliability, safety, watchdog timer, microcontroller. safety, reliability, dependability

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Flat and Multithreaded Programming Models for Solving Linear Systems of Equations by Jacobi Method

Plamenka Borovska, Milena Lazarova

Abstract: The paper investigates the efficiency of parallel computations for solving linear systems of equations using Jacobi method. Parallel computational models are suggested based on the flat parallel programming model with message passing in distributed memory system and parallel programming model of multithreading in shared memory system. Parallel communications profiling is made and performance parameters are evaluated on the basis of experimental results. Scalability of the suggested parallel models is estimated in respect to both the size of parallel workload and the size of parallel system.

Key words: linear systems, Jacobi method, scalable parallel systems, multithreading, message passing, parallel performance.

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Domain Ontology of Computer Networks

Boriana Deliiska

Abstract: With the advent of the Semantic Web ontologies from theoretical studies are becoming a technology and key issue for intelligent applications building. They are reusable knowledge bases in given area, developed on controlled vocabulary, taxonomy and thesaurus in the area. In the article common classification, relationships and elements of ontologies are given. On the base of certain methods a thesaurus and taxonomy of domain ontology of computer networks are developed. The ontology is presented by OWL language i Protégé editor environment.

Keywords: domain ontology, ontology engineering, taxonomy, thesaurus, computer network

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