Computer Science Journal (AGH University of Science and Technology, Krakow)
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USAGE OF DEDICATED DATA STRUCTURES FOR URL DATABASES IN A LARGE-SCALE CRAWLING
Get PDFThe article discuss usage of Berkeley DB data structures such as hash tables and b-trees forimplementation of a high performance URL database. The article presents a formal model fora data structures oriented URL database, which can be used as an alternative for a relationaloriented URL database
OPTIMIZATION OF TAU IDENTIFICATION IN ATLAS EXPERIMENT USING MULTIVARIATE TOOLS
Get PDFElementary particle physics experiments, which search for very rare processes, require theefficient analysis and selection algorithms able to separate a signal from the overwhelmingbackground. Four learning machine algorithms have been applied to identify τ leptons inthe ATLAS experiment: projective likelihood estimator (LL), Probability Density Estimatorwith Range Searches (PDE-RS), Neural Network, and the Support Vector Machine (SVM).All four methods have similar performance, which is significantly better than the baselinecut analysis. This indicates that the achieved background rejection is close to the maximal achievable performance
Verification mechanism for lightweight componenent-based environment based on IoC container
Get PDFThe paper presents a concept of component verification framework dedicated to a particular lightweight component environment. A starting point of the paper constitutes a discussion about significance of verification process of syntax inconsistencies in the software development. Next, the need of verification in service-oriented and component-based systems are presented and various approaches of verification in existing component environments are explained. The main part of the paper introduces a concept of a functional integrity of component-based systems that utilize verification mechanisms checking components consistency. The proposed solution is built on fine-grained component environment (close to classes similarly to the Spring Framework) realized in AgE platform. Selected technical aspects of the framework design illustrate the considerations of the paper
BUILDING SCIENCE GATEWAYS BY UTILIZING THE GENERIC WS-PGRADE/GUSE WORKFLOW SYSTEM
Get PDFEnabling scientists to use remote distributed infrastructures, parametrizeand execute common science-domain applications transparently is actual anda highly relevant field of distributed computing. For this purpose a general so-lution is the concept of Science Gateways. WS-PGRADE/gUSE system offersa transparent and web-based interface to access distributed resources (grids,clusters or clouds), extended by a powerful generic purpose workflow editorand enactment system, which can be used to compose scientific applicationsinto data-flow based workflow structures. It’s a generic web-based portal so-lution to organize scientific applications in a workflow structure and executethem on remote computational resources. As the portal defines nodes as black-box applications uploaded by the users, it does not provide any applicationspecific interface by default. In this paper we show what kind of tools, APIsand interfaces are available in WS-PGRADE/gUSE to customize it to have anapplication specific gateway
SUPPORT FOR DISTRIBUTED PROGRAMMING IN EXTREME STYLE
Get PDFThe basic limitation emerging from practising eXtreme Programming methodology is theconstraint of close physical proximity between the members of the collaborating team including customer. This became the main idea behind research on XP supporting environmentfor geographically distributed teams. This work presents basic assumptions, elaborated architecture and selected implementation issues for the system of this type. Deliberations aresupplied with the initial results of the verification of its usability based on the users tests
THE METHODOLOGY FOR DETECTING AND MANAGING THE ABUSE OF IT SYSTEMS
Get PDFThis paper focuses on the processes of dealing with security breaches which are becomingone of the most pressing problems in every organization whose systems are connected to theglobal web. The study presents the most widely used methodologies which were designed inorder to detect and react to security violations in a systematic and efficient way. Based onpresented methodologies, announced and supported by such credible organizations as SANS,NIST, CERT R or ISO, authors present their own methodology. It takes into account selectedaspects of these methodologies, with the purpose of creation a systematic and coherentapproach to the process of detecting and reacting to abuses in IT systems
ENHANCEMENTS OF FUZZY Q-LEARNING ALGORITHM
Get PDFFuzzy Q-Learning algorithm combines reinforcement learning techniques with fuzzy modelling. It provides a flexible solution for automatic discovery of rules for fuzzy systems inthe process of reinforcement learning. In this paper we propose several enhancements tothe original algorithm to make it more performant and more suitable for problems withcontinuous-input continuous-output space. Presented improvements involve generalizationof the set of possible rule conclusions. The aim is not only to automatically discover anappropriate rule-conclusions assignment, but also to automatically define the actual conclusions set given the all possible rules conclusions. To improve algorithm performance whendealing with environments with inertness, a special rule selection policy is proposed
COMPUTING RESOURCE AND WORK ALLOCATIONS USING SOCIAL PROFILES
Get PDFIf several distributed and disparate computer resources exist, many of whichhave been created for different and diverse reasons, and several large scale com-puting challenges also exist with similar diversity in their backgrounds, then oneproblem which arises in trying to assemble enough of these resources to addresssuch challenges is the need to align and accommodate the different motivationsand objectives which may lie behind the existence of both the resources andthe challenges. Software agents are offered as a mainstream technology formodelling the types of collaborations and relationships needed to do this. Asan initial step towards forming such relationships, agents need a mechanism toconsider social and economic backgrounds. This paper explores addressing so-cial and economic differences using a combination of textual descriptions knownas social profiles and search engine technology, both of which are integrated intoan agent technology
THE ATLAS EXPERIMENT ON-LINE MONITORING AND FILTERING AS AN EXAMPLE OF REAL-TIME APPLICATION
Get PDFThe ATLAS detector, recording LHC particles’ interactions, produces events with rate of40 MHz and size of 1.6 MB. The processes with new and interesting physics phenomena arevery rare, thus an efficient on-line filtering system (trigger) is necessary. The asynchronouspart of that system relays on few thousands of computing nodes running the filtering software.Applying refined filtering criteria results in increase of processing times what may lead tolack of processing resources installed on CERN site. We propose extension to this part ofthe system based on submission of the real-time filtering tasks into the Grid
SLA-ORIENTED SEMI-AUTOMATIC MANAGEMENT OF DATA STORAGE AND APPLICATIONS IN DISTRIBUTED ENVIRONMENTS
Get PDFIn this paper we describe a semi-automatic programming framework for supporting userswith managing the deployment of distributed applications along with storing large amountsof data in order to maintain Quality of Service in highly dynamic and distributed environments,e.g., Grid. The Polish national PL-GRID project aims to provide Polish science withboth hardware and software infrastructures which will allow scientists to perform complexsimulations and in-silico experiments on a scale greater than ever before. We highlight theissues and challenges related to data storage strategies that arise at the analysis stage ofuser requirements coming from different areas of science. Next we present a solution to thediscussed issues along with a description of sample usage scenarios. At the end we provideremarks on the current status of the implementation work and some results from the testsperformed