Numer czasopisma
Computer Science
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ISSN: 1508-2806
e-ISSN:
Data wydania
2013
Rocznik
Vol. 14
Numer
No. 4
Prawa dostępu
Dostęp: otwarty dostęp
Uwagi:
Prawa: CC BY 4.0 
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
FPGA-based DVCPRO HD decoder implementation using impulse C
(2013) Cichoń, Sławomir; Gorgoń, Marek
High-level languages (HLL) for defining hardware implementation are important in both academic and commercial research. Impulse C could be an example of such language. This environment provides a programming model and library of functions for parallel applications, targeting FPGA-based platforms with the ability to partition the algorithm between software and hardware. This article’s aim is to briefly describe DVCPRO HD, one of the intra-frame video-coding algorithms widely used in consumer equipment. DVCPRO HD is a DCT -based lossy video coding algorithm which uses variable-length coding (VLC) and run-length encoding (RLE) to achieve a 5:1 compression ratio. This paper presents DVCPRO HD video-coding-standard principles as well as decoder implementation working in real-time, compliant with the afore-mentioned standard and implemented in Impulse C. According to the authors’ knowledge, the presented solution is the first FPGA implementation of this coding standard which includes all three VLC stages of data re-arrangement. What is more, this is the first DVCPRO HD implementation which utilizes Impulse C.
Artykuł
Dostęp ograniczony
Preparation of control space for remeshing polygonal surfaces
(2013) Jurczyk, Tomasz; Głut, Barbara
The subject of the article concerns the issues of remeshing, transforming a polygonal mesh into a triangular mesh adapted to its surface. From the initial polygonal mesh, the curvature of surface and boundary is retrieved and used to calculate a metric tensor varying in three-dimensional space. In the proposed approach, the curvature is computed using local approximation of surfaces and curves on the basis of vertices of the polygonal mesh. An essential part of the presented remeshing procedure is a creation of a control space structure based on the retrieved discrete data. The subsequent process of remeshing is then supervised by the contents of this auxiliary structure. The article presents various aspects related to the procedure of initialization, creation, and adjustment of the control space structure.
Artykuł
Dostęp ograniczony
Evolutionary multi-agent systems in non-stationary environments
(2013) Kisiel-Dorohinicki, Marek
In this article, the performance of an evolutionary multi-agent system in dynamic optimization is evaluated in comparison to classical evolutionary algorithms. The starting point is a general introduction describing the background, structure and behavior of EMAS against classical evolutionary techniques. Then, the properties of energy-based selection are investigated to show how they may influence the diversity of the population in EMAS. The considerations are illustrated by experimental results based on the dynamic version of the well-known, high-dimensional Rastrigin function benchmark.
Artykuł
Dostęp ograniczony
Verification mechanism for lightweight component-based environment based on IoC container
(2013) Leszko, Rafał; Piętak, Kamil
This paper presents a concept of component verification framework dedicated to a particular lightweight component environment. The starting point of the paper constitutes a discussion about the significance of verification of syntax inconsistencies in software development. Next, the need of verification in service-oriented and component-based systems is presented, and various approaches of verification in existing component environments are explained. The main part of the paper introduces a concept of functional integrity of component-based systems that utilize verification mechanisms which check consistency between components. The proposed solution is built on a fine-grained component environment (close to classes similarly to the Spring Framework) realized in the AgE platform. Selected technical aspects of framework design illustrate the considerations of the paper.
Artykuł
Dostęp ograniczony
Grammar based multi-frontal solver for isogeometric analysis in 1D
(2013) Kuźnik, Krzysztof; Paszyński, Maciej; Calo, Victor Manuel
In this paper, we present a multi-frontal direct solver for one-dimensional isogeometric finite element method. The solver implementation is based on the graph grammar (GG) model. The GG model allows us to express the entire solver algorithm, including generation of frontal matrices, merging, and eliminations as a set of basic undividable tasks called graph grammar productions. Having the solver algorithm expressed as GG productions, we can find the partial order of execution and create a dependency graph, allowing for scheduling of tasks into shared memory parallel machine. We focus on the implementation of the solver with NVIDIA CUDA on the graphic processing unit (GPU). The solver has been tested for linear, quadratic, cubic, and higher-order B-splines, resulting in logarithmic scalability.
Artykuł
Dostęp ograniczony
On the evolution of migrating population with two competing species
(2013) Magdoń, Maria; Maksymowicz, Andrzej
A computer experiment study of population evolution and its dynamics is presented for two competing species (A and B) which share two habitats (1 and 2) of a limited environmental capacity. The Penna model of biological aging, based on the concept of defective mutation accumulation, was adopted for migrating population. In this paper, we assume and concentrate on the case when only one species (A) is mobile. For isolated habitats and for any initial population, we get at equilibrium spatial population distribution (A, B) in which A occupies location ’1’ only, while B-species is the ultimate winner in ’2’. This is achieved by suitable choice of model parameters so habitat ’1’ is more attractive for species ’A’ while location ’2’ is more advantageous to ’B’. However, population distribution begins to differ when migration between habitats is allowed. Initially stable distribution (A, B), becomes (A, A&B) with a mixed stationary population in location ’2’. For a higher migration rate, initial (A, B) distribution goes to (A, A) distribution, in which A species is dominant also in a less friendly habitat ’2’. However, a further increase in migration rate brings sequence (A, B) ? (B, B). In short, for sufficiently high mobility of A-species, they eliminate themselves. Other scenarios not discussed here were also studied. They offer a rich variety of different sequences of population distribution regarding their size as well as other characteristics.
Artykuł
Dostęp ograniczony
HP-HGS strategy for inverse AC/DC resistivity logging measurement simulations
(2013) Gajda-Zagórska, Ewa; Paszyński, Maciej; Schaefer, Robert; Pardo, David
In this paper, we present resistivity-logging-measurement simulation with the use of two types of borehole logging devices: those which operate with zero frequency (direct current, DC) and those with higher frequencies (alternate current, AC). We perform simulations of 3D resistivity measurements in deviated wells, with a sharp angle between the borehole and formation layers. We introduce a hierarchical adaptive genetic strategy hp ? HGS interfaced with an adaptive finite element method. We apply a strategy for the solution of the inverse problem, where we identify the resistivities of the formation layers based on a given measurement. We test the strategy on both direct and alternate current cases.
Artykuł
Dostęp ograniczony
Staged event-driven architecture as a micro-architecture of distributed and pluginable crawling platform
(2013) Siwik, Leszek; Włodarczyk, Kamil; Kluczny, Mateusz
Crawling systems available on the market are usually closed solutions dedicated to performing a particular kind of task. There is a meaningful group of users, however, which require an all–in–one studio, not only for executing and running Internet robots, but also for (graphical) (re)defining and (re)composing crawlers according to dynamically changing requirements and use–cases. The Cassiopeia framework addresses the above idea. The crucial aspect regarding its efficiency and scalability is concurrency model applied. One of the promising models is staged event–driven architecture providing some useful benefits, such as splitting an application into separate stages connected by events’ queues–which is interesting, taking into account Cassiopeia’s assumptions regarding crawler (re)composition. The goal of this paper is to present the idea and PoC implementation of the Cassiopeia framework, with special attention paid to its crucial architectural element, i.e., design, implementation, and application of staged event–driven architecture.
Artykuł
Dostęp ograniczony
Message-oriented communication for IPv6-enabled pervasive devices
(2013) Szydło, Tomasz; Suder, Paweł; Bibro, Jakub
An increasing number of electronic devices are being equipped with radio interfaces intended for communication with and control by other devices and applications. Wireless communication in this class of devices may be exposed to a number of situations that can occur, including limited energy resources, equipment failures, node mobility, and loss of communication between nodes. Ultimately, commonly-used standards and protocols for sharing services are not practical and do not take into account the occurrence of such problems. This paper presents a concept of communication that relies on the exchange of messages between wireless-pervasive devices commonly found in our environment.
Artykuł
Dostęp ograniczony
The comparison of parallel sorting algorithms implemented on different hardware platforms
(2013) Pietroń, Marcin; Wielgosz, Maciej; Wiatr, Kazimierz; Żurek, Dominik
Sorting is a common problem in computer science. There are a lot of well-known sorting algorithms created for sequential execution on a single processor. Recently, many-core and multi-core platforms have enabled the creation of wide parallel algorithms. We have standard processors that consist of multiple cores and hardware accelerators, like the GPU. Graphic cards, with their parallel architecture, provide new opportunities to speed up many algorithms. In this paper, we describe the results from the implementation of a few different parallel sorting algorithms on GPU cards and multi-core processors. Then, a hybrid algorithm will be presented, consisting of parts executed on both platforms (a standard CPU and GPU). In recent literature about the implementation of sorting algorithms in the GPU, a fair comparison between many core and multi-core platforms is lacking. In most cases, these describe the resulting time of sorting algorithm executions on the GPU platform and a single CPU core.