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Computer Science

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ISSN: 1508-2806
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Data wydania
2013
Rocznik
Vol. 14
Numer
No. 2
Prawa dostępu
Dostęp: otwarty dostęp
Uwagi:
Prawa: CC BY 4.0
Attribution 4.0 International
Uznanie autorstwa 4.0 Międzynarodowe (CC BY 4.0)

Strony
Opis
Rocznik czasopisma (rel.)
Rocznik czasopisma
Computer Science
Vol. 14 (2013)
Artykuły numeru (rel.)
Artykuł
Dostęp ograniczony
Data storage management using AI methods
(2013) Funika, Włodzimierz; Szura, Filip
Data management and monitoring is an important issue in scientific computation. Scientists want to access their data as quickly as possible. Some experiments need to store a lot of data which have to be secure. By saying this we mean that this data can not disappear or be damaged also the data storage should be as cheap as possible. In this paper we present an approach to the automation of monitoring and management of data storage. We introduce a knowledge based system which is able to manage data, i.e., make decisions on migrating data, replicating or removing it. We discuss some of the existing solutions which are popular on the market. In this paper we aim to present our system which uses such AI techniques like fuzzy logic or a rule-based expert system to deal with data storage management. We exploit in this system a cost model to analyze the proposed solutions. The operations performed by our system are aimed to optimize the usage of the monitored infrastructure.
Artykuł
Dostęp ograniczony
Unsupervised labeling of data for supervised learning and its application to medical claims prediction
(2013) Wojtusiak, Janusz; Ngufor, Che G.
The task identifying changes and irregularities in medical insurance claim payments is a difficult process of which the traditional practice involves querying historical claims databases and flagging potential claims as normal or abnormal. Because what is considered as normal payment is usually unknown and may change over time, abnormal payments often pass undetected, only to be discovered when the payment period has passed. This paper presents the problem of on-line unsupervised learning from data streams when the distribution that generates the data changes or drifts over time. Automated algorithms for detecting drifting concepts in a probability distribution of the data are presented. The idea behind the presented drift detection methods is to transform the distribution of the data within a sliding window into a more convenient distribution. Then, a test statistics p-value at a given significance level can be used to infer the drift rate, adjust the window size and decide on the status of the drift. The detected concepts drifts are used to label the data, for subsequent learning of classification models by a supervised learner. The algorithms were tested on several synthetic and real medical claims data sets.
Artykuł
Dostęp ograniczony
Web pages content analysis using browser-based volunteer computing
(2013) Turek, Wojciech; Nawarecki, Edward; Dobrowolski, Grzegorz; Krupa, Tomasz; Majewski, Przemysław
Existing solutions to the problem of finding valuable information on the Web suffers from several limitations like simplified query languages, out-of-date in- formation or arbitrary results sorting. In this paper a different approach to this problem is described. It is based on the idea of distributed processing of Web pages content. To provide sufficient performance, the idea of browser-based volunteer computing is utilized, which requires the implementation of text processing algorithms in JavaScript. In this paper the architecture of Web pages content analysis system is presented, details concerning the implementation of the system and the text processing algorithms are described and test results are provided.
Artykuł
Dostęp ograniczony
The application of a noise mapping tool deployed in grid infrastructure for creating noise maps of urban areas
(2013) Szczodrak, Maciej; Kotus, Józef; Czyżewski, Andrzej; Kostek, Bożena
The concept and implementation of the system for creating dynamic noise maps in PL-Grid infrastructure are presented. The methodology of dynamic acoustical map screating is introduced. The concept of noise mapping, based on noise source and propagation models, was developed and employed in the system. The details of incorporation of the system to the PL-Grid infrastructure are presented. The results of simulations performed by the system prototype are depicted. The results in the form of noise maps obtained by a system are compared with some other solutions in order to investigate accuracy.
Artykuł
Dostęp ograniczony
Accelerating SELECT WHERE and SELECT JOIN queries on a GPU
(2013) Pietroń, Marcin; Russek, Paweł; Wiatr, Kazimierz
This paper presents implementations of a few selected SQL operations using the CUDA programming framework on the GPU platform. Nowadays, the GPU’s parallel architectures give a high speed-up on certain problems. Therefore, the number of non-graphical problems that can be run and sped-up on the GPU still increases. Especially, there has been a lot of research in data mining on GPUs. In many cases it proves the advantage of offloading processing from the CPU to the GPU. At the beginning of our project we chose the set of SELECT WHERE and SELECT JOIN instructions as the most common operations used in databases. We parallelized these SQL operations using three main mechanisms in CUDA: thread group hierarchy, shared memories, and barrier synchronization. Our results show that the implemented highly parallel SELECT WHERE and SELECT JOIN operations on the GPU platform can be significantly faster than the sequential one in a database system run on the CPU.
Artykuł
Dostęp ograniczony
Extending the SHEBA Propagation Model to reduce parameter-related uncertainties
(2013) Pierantoni, Gabriele; Kenny, Eamonn; Pérez-Suárez, David; Coghlan, Brian A.; Gallagher, Peter T.
Heliophysics is the branch of physics that investigates the interactions and correlation of different events across the Solar System. The mathematical models that describe and predict how physical events move across the solar system (ie. Propagation Models ) are of great relevance. These models depend on parameters that users must set, hence the ability to correctly set the values is key to reliable simulations. Traditionally, parameter values can be inferred from data either at the source (the Sun) or arrival point (the target) or can be extrapolated from common knowledge of the event under investigation. Another way of setting parameters for Propagation Models is proposed here: instead of guessing a priori parameters from scientific data or common knowledge, the model is executed as a parameter-sweep job and selects a posteriori the parameters that yield results most compatible with the event data. In either case ( a priori and a posteriori ), the correct use of Propagation Models requires information to either select the parameters, validate the results, or both. In order to do so, it is necessary to access sources of information. For this task, the HELIO project proves very effective as it offers the most comprehensive integrated information system in this domain and provides access and coordination to services to mine and analyze data. HELIO also provides a Propagation Model called SHEBA, the extension of which is currently being developed within the SCI-BUS project (a coordinated effort for the development of a framework capable of offering to science gateways seamless access to major computing and data infrastructures).
Artykuł
Dostęp ograniczony
Computing resource and work allocations using social profiles
(2013) Lavin, Peter; Kenny, Eamonn; Coghlan, Brian A.
If several distributed and disparate computer resources exist, many of which have been created for different and diverse reasons, and several large scale computing challenges also exist with similar diversity in their backgrounds, then one problem which arises in trying to assemble enough of these resources to address such challenges is the need to align and accommodate the different motivations and objectives which may lie behind the existence of both the resources and the challenges. Software agents are offered as a mainstream technology for modelling the types of collaborations and relationships needed to do this. As an initial step towards forming such relationships, agents need a mechanism to consider social and economic backgrounds. This paper explores addressing social and economic differences using a combination of textual descriptions known as social profiles and search engine technology, both of which are integrated into an agent technology.
Artykuł
Dostęp ograniczony
WebALLTED - interdisciplinary modeling in grid and cloud
(2013) Zgurovs'kij, Mihajlo Zaharovič; Petrenko, Anatolij Ivanovič; Ladogubec', Volodimir Vasil'ovič; Fìnogenov, Oleksij Dmitrovič; Bulah, Bogdan Vìktorovìč
This paper presents a multi-layered architecture of computer simulation software capable of utilizing grid and cloud resources, characterized in that the functionality of the system is distributed according to a service-oriented approach, and the system supports the execution of custom user-defined computing scenarios in grid or in cloud (by web services orchestration with an adherence to existing standards) but hides the complexity of direct web services management from the user with the help of the abstract workflow model and a web-accessible problem solving environment with a graphical workflow editor.
Artykuł
Dostęp ograniczony
Building science gateways by utilizing the generic WS-PGRADE/gUSE workflow system
(2013) Balaskó, Ákos; Farkas, Zoltán; Kacsuk, Péter
Enabling scientists to use remote distributed infrastructures, parametrize and execute common science-domain applications transparently is actual and a highly relevant field of distributed computing. For this purpose a general solution is the concept of Science Gateways. WS-PGRADE/gUSE system offers a transparent and web-based interface to access distributed resources (grids, clusters or clouds), extended by a powerful generic purpose workflow editor and enactment system, which can be used to compose scientific applications into data-flow based workflow structures. It’s a generic web-based portal solution to organize scientific applications in a workflow structure and execute them on remote computational resources. As the portal defines nodes as black-box applications uploaded by the users, it does not provide any application specific interface by default. In this paper we show what kind of tools, APIs and interfaces are available in WS-PGRADE/gUSE to customize it to have an application specific gateway.
Artykuł
Dostęp ograniczony
Exploit relations between the word letters and their placement in the word for Arabic root extraction
(2013) Abu-Hawas, Fatima Y.
This paper presents a new root-extraction approach for Arabic words. The approach tries to assign for Arabic words a unique root without relying on a database of word roots, a list of word patterns or a list of all the prefixes and the suffixes of the Arabic words. Unlike most of Arabic rule-based stemmers, it tries to predict the root-letters positions one by one based on some rules and relations among the word letters and their placement in the word. This paper focuses on two parts of the approach. The first one introduces some rules to distinguish between the Arabic definite article and the permanent component that may found in any Arabic word. The second one classifies Arabic letters in to groups according to their positions in the word. The proposed approach is a system composed of several modules used to extract the word root. The approach has been evaluated using the Holy Quran words. The evaluation results show a promising root extraction algorithm.
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