Computer Science Journal (AGH University of Science and Technology, Krakow)
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USING BOINC DESKTOP GRID TO SOLVE LARGE SCALE SAT PROBLEMS
Get PDFMany practically important combinatorial problems can be efficiently reducedto a problem of Boolean satisfiability (SAT). Therefore, the implementation ofdistributed algorithms for solving SAT problems is of great importance. In thisarticle we describe a technology for organizing desktop grid, which is meantfor solving SAT problems. This technology was implemented in the form ofa volunteer computing project SAT@home based on a popular BOINC platform
MANAGEMENT METHODS IN SLA-AWARE DISTRIBUTED STORAGE SYSTEMS
Get PDFTraditional data storage systems provide access to user’s data on the “besteffort” basis. While this paradigm is sufficient in many use cases it becomesan obstacle for applications with Quality of Service (QoS) constraints. ServiceLevel Agreement (SLA) is a part of the contract agreed between the serviceprovider and the client and contains a set of well defined QoS requirementsregarding the provided service and the penalties applied in case of violations.In the paper we propose a set of SLA parameters and QoS metrics relevantto data storage processes and the management methods necessary for avoidingSLA violations. A key assumption in the proposed approach is that the underlyingdistributed storage system does not provide functionality for resource orbandwidth reservation for a given client request
GPU ENHANCED SIMULATION OF ANGIOGENESIS
Get PDFIn the paper we present the use of graphic processor units to accelerate the most time-consuming stages of a simulation of angiogenesis and tumor growth. By the use of advanced CUDA mechanisms such as shared memory, textures and atomic operations, we managed to speed up the CUDA kernels by a factor of 57x. However, in our simulation we used the GPU as a co-processor and data from CPU was copied back and forth in each phase. It decreased the speedup of rewritten stages by 40%. We showed that the performance of the entire simulation can be improved by a factor of 10 up to 20
RECOVERY AND MIGRATION OF APPLICATION LOGIC FROM LEGACY SYSTEMS
Get PDFFuture Internet technologies necessitate dramatic changes in system design, deliveryand usage patterns. For many legacy applications it means that their furtherdevelopment and transition to the Internet becomes problematic or evenimpossible due to the obsolescence of technologies they use. Replacement ofthe old system with the new one, built from scratch, is usually economicallyunacceptable. Therefore, there is a call for methods and tools supportingthe automated migration of legacy systems into a new paradigm. This paperproposes a tool supported method for recovery and migration of applicationlogic information from legacy systems. The information extracted from a legacyapplication is stored in the form of precise requirement-level models enablingautomated transformation into a new system structure in a model-driven way.Evaluation of the approach is based on a case study legacy system
CONSIDERATION OF THE SPECIFICS OF UNDERSTANDING TEXTUAL COMMUNIQU´ES IN DESIGNING DIALOGUES WITH A USER OF AN INFORMATION SYSTEM
Get PDFThe paper presents a proposal to take into account the language comprehensionparadigm in an attempt to improve the design methodology of human-computerdialogues. It is assumed that the user treats a system as a subject, i.e. perceivescommunication with the system as a kind of discourse and intuitively treats itas cognition of the world through a fixed image of objective linguistic signs. Dueto the fact that every end-user of a computer system has an individual linguisticcompetence, thesaurus, habits, previous experiences, one can never guaranteethat identical semantic references arise in a variety of audiences. The situationbecomes more stable if one considers the communication aspect of comprehensionon the basis of practice (familiarity of things). It may be expected thata qualified professional user will commit fewer errors, caused by a poor dialogueunderstanding while interacting with the system. Therefore, the main taskof a designer is to speed up and facilitate the learning process, which can beachieved by running the process of constructive rational understanding
INTERACTIVE CLOUD DATA FARMING ENVIRONMENT FOR MILITARY MISSION PLANNING SUPPORT
Get PDFIn a modern globalised world, military and peace keeping forces often face situations which require very subtle and well planned operations taking into account cultural and social aspects of a given region and its population as well as dynamic psychological awareness related to recent events which can have impact on the attitude of the civilians. The goal of the EUSAS project is to develop a prototype of a system enabling mission planning support and training capabilities for soldiers and police forces dealing with asymmetric threat situations, such as crowd control in urban territory. In this paper, we discuss the data-farming infrastructure developed for this project, allowing generation of large amount of data from agent based simulations for further analysis allowing soldier training and evaluation of possible outcomes of different rules of engagement
MONTE CARLO SIMULATIONS FOR THE CHERENKOV TELESCOPE ARRAY OBSERVATORY USING PL-GRID E-INFRASTRUCTURE
Get PDFThe paper presents Monte Carlo simulations carried out during the preparatory phase of the Cherenkov Telescope Array project. The aim of the project is to build the next generation observatory of very high energy gamma rays. During the preparatory phase there is a need to optimize and verify design concepts for various elements of the array. In this paper we describe the main components of the software being used for that purpose, their functions and requirements. Preliminary results of the optimization of the small telescope – one of the several kinds intended for the array, are presented
DISTRIBUTED WEB-SCALE INFRASTRUCTURE FOR CRAWLING, INDEXING AND SEARCH WITH SEMANTIC SUPPORT
Get PDFIn this paper, we describe our work in progress in the scope of web-scale informationextraction and information retrieval utilizing distributed computing. Wepresent a distributed architecture built on top of the MapReduce paradigm forinformation retrieval, information processing and intelligent search supportedby spatial capabilities. Proposed architecture is focused on crawling documentsin several different formats, information extraction, lightweight semantic annotationof the extracted information, indexing of extracted information andfinally on indexing of documents based on the geo-spatial information foundin a document. We demonstrate the architecture on two use cases, where thefirst is search in job offers retrieved from the LinkedIn portal and the second issearch in BBC news feeds and discuss several problems we had to face duringthe implementation. We also discuss spatial search applications for both casesbecause both LinkedIn job offer pages and BBC news feeds contain a lot of spatialinformation to extract and process
AN ANALYSIS OF METHODS FOR SHARING AN ELECTRONIC PLATFORM OF PUBLIC ADMINISTRATION SERVICES USING CLOUD COMPUTING AND SERVICE ORIENTED ARCHITECTURE
Get PDFThis paper presents a case study on how to design and implement a publicadministration services platform, using the SOA paradigm and cloud model forsharing among citizens belonging to particular districts and provinces, providingtight integration with an existing ePUAP system. The basic requirements,architecture and implementation of the platform are all discussed. Practicalevaluation of the solution is elaborated using real-case scenario of the BusinessProcess Management related activities
AN EVOLUTION PROCESS FOR SERVICE-ORIENTED SYSTEMS
Get PDFEvolution of service-oriented systems is quite a new research area, which becomesmore and more important as engineering challenges move from enablingservice-orientation onto the maintenance and evolution of already developedservice-oriented systems. However, the development of suitable evolution processesand methodologies is still an open research problem. The evolution processpresented in this paper has been designed to address the evolution of serviceorientedsystems, which are technically built out of a set of service compositions.The presented process comprises phases and tasks compliant with ISO 20000.The underlying model of service-oriented system consisting of business processesand corresponding service composition models has also been presented. A traceabilitymodel and tools supporting change impact analysis have also beenprovisioned for. Preliminary industrial validation indicates that the evolutionprocess should be easy to adapt by the industry