Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "Walkowiak, K." wg kryterium: Autor

  Lista filtrów
Wyrównaj
Wyświetlanie 1-15 z 41
Tytuł:
A column generation technique for routing and spectrum allocation in cloud-ready survivable elastic optical networks
Autorzy:
Goścień, R.
Walkowiak, K.
Powiązania:
https://bibliotekanauki.pl/articles/330528.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
elastic optical network
anycast traffic
multicast traffic
network survivability
column generation technique
elastyczna sieć optyczna
sieć przełącznikowa
przeżywalność sieci
Opis:
Driven by increasing user requirements and expectations, the fast development of telecommunications networks brings new challenging optimization problems. One of them is routing and spectrum allocation (RSA) of three types of network flows (unicast, anycast, multicast) in elastic optical networks (EONs) implementing dedicated path protection (DPP). In the paper, we model this problem as integer linear programming (ILP) and we introduce two new optimization approaches—a dedicated heuristic algorithm and a column generation (CG)-based method. Then, relying on extensive simulations, we compare algorithm performance with reference methods and evaluate CG efficiency in detail. The results show that the proposed CG method significantly outperforms reference algorithms and achieves results very close to optimal ones (the average distance to optimal results was at most 2.1%).
Źródło:
International Journal of Applied Mathematics and Computer Science; 2017, 27, 3; 591-603
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An exact algorithm for design of content delivery networks in MPLS environment
Autorzy:
Walkowiak, K.
Powiązania:
https://bibliotekanauki.pl/articles/308183.pdf
Data publikacji:
2004
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
content delivery network
optimization
branch-and-cut algorithm
Opis:
Content delivery network (CDN) is an efficient and inexpensive method to improve Internet service quality. In this paper we formulate an optimisation problem of replica location in a CDN using MPLS techniques. A novelty, comparing to previous work on this subject, is modelling the network flow as connection-oriented and introduction of capacity constraint on network links to the problem. Since the considered optimisation problem is NP-complete, we propose and discuss exact algorithm based on the branch-and-cut and branch-and-bound methods. We present results of numerical experiments showing comparison of branch-and-cut and branch-and-bound methods.
Źródło:
Journal of Telecommunications and Information Technology; 2004, 2; 13-22
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ant Algorithm for Flow Assignment in Connection-oriented Networks
Autorzy:
Walkowiak, K.
Powiązania:
https://bibliotekanauki.pl/articles/911137.pdf
Data publikacji:
2005
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
algorytm mrówkowy
przypisanie przepływu
sieć komputerowa
ant algorithms
flow assignment
computer networks
Opis:
This work introduces ANB (Ant Algorithm for Non-Bifurcated Flows), a novel approach to capacitated static optimization of flows in connection-oriented computer networks. The problem considered arises naturally from several optimization problems that have recently received significant attention. The proposed ANB is an ant algorithm motivated by recent works on the application of the ant algorithm to solving various problems related to computer networks. However, few works concern the use of ant algorithms in the assignment of static flows in connection-oriented networks. We analyze the major characteristics of the ANB and try to explain its performance. We report results of many experiments over various networks.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2005, 15, 2; 205-220
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Anycasting in connection-oriented computer networks: Models, algorithms and results
Autorzy:
Walkowiak, K.
Powiązania:
https://bibliotekanauki.pl/articles/907768.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
sieć połączeniowa
optymalizacja
MPLS
odporność
anycasting
connection-oriented networks
optimization
survivability
Opis:
Our discussion in this article centers around various issues related to the use of anycasting in connection-oriented computer networks. Anycast is defined as a one-to-one-of-many transmission to deliver a packet to one of many hosts. Anycasting can be applied if the same content is replicated over many locations in the network. Examples of network techniques that apply anycasting are Content Delivery Networks (CDNs), Domain Name Service (DNS), Peer-to-Peer (P2P) systems. The role of anycasting is growing concurrently with the popularity of electronic music, movies, and other content required by Internet users. In this work we focus on the optimization of anycast flows in connection-oriented networks. We formulate a model of anycast connections and next propose a heuristic algorithm based on the Lagrangean relaxation aimed to optimize jointly routes for anycast and unicast connections. Results of numerical experiments are presented and evaluated. Finally, we analyze briefly problems related to anycasting in dynamic routing and multi-layer networks.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2010, 20, 1; 207-220
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative Morphological Analysis of Graphene on Copper Substrate obtained by CVD from a Liquid Precursor
Autorzy:
Weiss, M.
Walkowiak, M.
Wasiński, K.
Półrolniczak, P.
Kokocińska, B.
Strupiński, W.
Powiązania:
https://bibliotekanauki.pl/articles/1032380.pdf
Data publikacji:
2017-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
68.65.Pq
81.05.ue
Opis:
Graphene film has been produced on untreated Cu substrate by a chemical vapor deposition technique in ambient pressure with liquid ethanol serving as the carbon precursor. The obtained material has been subjected to morphological study, directly on Cu substrate, by means of optical microscopy, scanning electron microscopy, atomic force microscopy, and a detailed Raman analysis. As a benchmark material, graphene obtained on Cu by a conventional CVD from gaseous methane was used. This simple experimental setup has proved to enable obtaining large area graphene samples with nearly 100% substrate coverage and large domains of one carbon layer. As compared to graphene from gaseous precursor, the presented approach resulted in visibly more defects and impurities. These imperfections are due to more complex precursor molecular structure and lack of Cu pretreatment with hydrogen, the later cause being easy to eliminate in course of further optimization of the method. The described approach can be regarded as a viable, low-cost, and experimentally simple alternative for the existing techniques of producing large area graphene. By providing direct comparison with the conventional method, the paper's intention is to provide deeper insight and to fill gap in the understanding of mechanisms involved in graphene formation on copper.
Źródło:
Acta Physica Polonica A; 2017, 131, 6; 1497-1506
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of Evolutionary Algorithm and Heuristics for Flow Optimization in P2P Systems
Autorzy:
Kucharzak, M.
Siwek, A.
Walkowiak, K.
Powiązania:
https://bibliotekanauki.pl/articles/226952.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
P2P
flows
network optimization
Opis:
Nowadays, many Internet users make use of Peer-to-Peer (P2P) systems to download electronic content including music, movies, software, etc. Growing popularity in P2P based protocol implementations for file sharing purposes caused that the P2P traffic exceeds Web traffic and in accordance with to many statistics, P2P systems produce a more than 50% of the whole Internet traffic. Therefore, P2P systems provide remarkable income for Internet Service Providers (ISP). However, at the same time P2P systems generates many problems related to traffic engineering, optimization, network congestion. In this paper we focus on the problem of flow optimization in P2P file sharing systems. Corresponding to BitTorrent-based systems behaviour, the optimization of P2P flows is very complex and in this work we consider different heuristic strategies for content distribution and moreover we propose a new evolutionary algorithm (EA) for this problem. We compare results of the algorithms against optimal results yielded by CPLEX solver for networks including 10 peers and relation to random algorithm for 100-node systems. According to numerical experiments, the EA provides solutions close to optimal for small instances and all of the heuristics exhibit a superior performance over random search.
Źródło:
International Journal of Electronics and Telecommunications; 2010, 56, 2; 145-152
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comprehensive biological evaluation of biomaterials used in spinal surgery
Autorzy:
Komorowski, P.
Kamińska, M.
Jakubowski, W.
Szymański, W.
Walczyńska, M.
Siatkowska, M.
Działoszyńska, K.
Sokołowska, P.
Białkowska, K.
Wasiak, T.
Elgalal, M.
Makowski, K.
Kierzkowska, A.
Ciupik, L.
Walkowiak, B.
Powiązania:
https://bibliotekanauki.pl/articles/283763.pdf
Data publikacji:
2017
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
biomaterials
spinal surgery
biological tests
Źródło:
Engineering of Biomaterials; 2017, 20, no. 143 spec. iss.; 23
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design and manufacture of customized medical implants
Autorzy:
Elgalal, M.
Komorowski, P.
Makowski, K.
Styczyński, A.
Ulański, P.
Kubiak, T.
Sawicki, J.
Domżalski, M.
Walkowiak, B.
Powiązania:
https://bibliotekanauki.pl/articles/285113.pdf
Data publikacji:
2018
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
implants
patient anatomy
manufacturing
Źródło:
Engineering of Biomaterials; 2018, 21, 148; 36
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Environmentally friendly car plastics in automotive engineering. Part I
Ekologiczny samochód. Tworzywa sztuczne w technice motoryzacyjnej. Część 1
Autorzy:
Bielefeldt, K.
Papacz, W.
Walkowiak, J.
Powiązania:
https://bibliotekanauki.pl/articles/1365006.pdf
Data publikacji:
2011
Wydawca:
Sieć Badawcza Łukasiewicz. Przemysłowy Instytut Motoryzacji
Tematy:
części z tworzyw wzmocnionych i kompozytów
konstrukcje hybrydowe
materiały wzmacniające
samochód ekologiczny
technologie przetwórstwa tworzyw wzmocnionych i kompozytów
environmentally friendly car
hybrid structures
toughened plastic and composite parts
toughened plastics and composite materials processing technologies
toughening and reinforcing materials
Opis:
The possibilities to use polymer plastics in automotive engineering from the point of view of the manufacturing of an environmentally-friendly car have been presented in this paper. The general requirements to be met by such materials have been discussed and the possibilities of significant improvement of, inter alia, mechanical strength properties of polymer plastics by the use of appropriate additives, inclusive of carriers, have been indicated. The most frequently used plastics and numerous toughening materials have been mentioned. Many examples of the application of plastics toughened with the most recent materials, e.g. nanomaterials or, in consideration of the ecological aspect, natural fibres have been presented. The essence of the most modern technologies making it possible to manufacture vehicle components from plastics toughened with various carriers has also been described, which also covers the issue of hybrid structures.
W artykule przedstawiono możliwości stosowania tworzyw polimerowych w motoryzacji w aspekcie produkcji samochodu ekologicznego. Omówiono ogólne wymagania stawiane materiałom oraz wskazano możliwości znacznego zwiększenia między innymi właściwości wytrzymałościowych tworzyw polimerowych poprzez stosowanie odpowiednich dodatków, a w tym nośników. Wymieniono najczęściej stosowane tworzywa oraz liczne materiały wzmacniające. Przedstawiono liczne przykłady zastosowań tworzyw wzmocnionych najnowszymi materiałami, np. nanomateriały, jak i z uwagi na ekologiczny aspekt - włóknami naturalnymi. Opisano także istotę najnowszych technologii umożliwiających wytworzenie części samochodowych z tworzyw wzmocnionych różnymi nośnikami, w tym także w odniesieniu do konstrukcji hybrydowych.
Źródło:
Archiwum Motoryzacji; 2011, 2; 7-21
1234-754X
2084-476X
Pojawia się w:
Archiwum Motoryzacji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Environmentally friendly car reinforced plastics in automotive engineering structural design considerations. Part II
Ekologiczny samochód. Wzmocnione tworzywa sztuczne w technice motoryzacyjnej. Rozważania konstrukcyjne. Część 2
Autorzy:
Bielefeldt, K.
Papacz, W.
Walkowiak, J.
Powiązania:
https://bibliotekanauki.pl/articles/1365036.pdf
Data publikacji:
2011
Wydawca:
Sieć Badawcza Łukasiewicz. Przemysłowy Instytut Motoryzacji
Tematy:
kompozyty polimerowe
nadwozie pojazdu
resor kompozytowy
układ napędowy
composite leaf spring
polymer composite
power transmission system
vehicle body
Opis:
A review of applications of reinforced polymers and polymer composites to the construction of automotive vehicles has been presented. Particular attention has been paid to the heavily loaded parts and subassemblies. Various components of vehicle body and power transmission and suspension systems, as well as subassemblies situated in the engine compartment have been analysed. In each case, the structure of the part involved, the material type used, and the loads to be borne have been described. The parts to be analysed have been deliberately selected to show the technological progress that takes place in the application of reinforced plastics to the construction of load-bearing structures of modern vehicles. The paper has been provided with conclusions concerning the development trends and directions of further research in the field of the use of reinforced polymers for the construction of vital vehicle parts and subassemblies.
W artykule przedstawiono przegląd zastosowań polimerów wzmocnionych i kompozytów polimerowych w budowie pojazdów samochodowych. Szczególną uwagę zwrócono na części i podzespoły przenoszące duże obciążenia. Analizie poddano elementy nadwozia pojazdu, układu napędowego, zawieszenia oraz podzespoły komory silnika. Każdorazowo opisywano budowę podzespołu, rodzaj użytego do jego budowy materiału oraz obciążenia jakim jest poddawany. Części do analizy dobierano tak, aby pokazać postęp technologiczny jaki następuje w stosowaniu tworzyw wzmocnionych do budowy struktur nośnych współczesnych pojazdów. Artykuł zakończono wnioskami dotyczącymi tendencji rozwojowych oraz kierunków dalszych badań w obszarze stosowania polimerów wzmocnionych na odpowiedzialne podzespoły i części pojazdów.
Źródło:
Archiwum Motoryzacji; 2011, 4; 7-19
1234-754X
2084-476X
Pojawia się w:
Archiwum Motoryzacji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of Candida albicans adhesion on AlSl-316L and Ti6Al4V in changing environmental conditions
Autorzy:
Jastrzębska, A.
Jakubowski, W.
Jastrzębski, K.
Walkowiak, B.
Powiązania:
https://bibliotekanauki.pl/articles/286042.pdf
Data publikacji:
2017
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
biofilm
Candida albicans
glucose level
culture conditions
biomaterials
Opis:
Currently, studies on the formation of microbiological biofilm on biomaterial surfaces and medical devices have become an important aspect in medicine. In vivo studies of the biofilm development show a high correlation between the environmental factors and attachment of microorganisms to artificial surfaces. This paper is devoted to determining the impact of specific environmental stimuli and parameters of cultivation of Candida albicans yeasts on their adhesion to AISI-316L and Ti6Al4V substrates. Environmental parameters include variable glucose concentrations in YPG growth medium (0, 2, 4 and 10% wt.). Development of yeasts was also analyzed in terms of variable nutrients level i.e. transferring samples from medium with low nutrients level to other with higher glucose content. Another studied parameter was incubation time and how much fungal colonization varies during 24 and 48 h of incubation. For all samples, the number of both live and dead cells was taken into account. The results showed that with the increase in sugar content in culture media, biofilm development was observed, especially on AISI 316L surface. Also, significant changes in the number of adhered cells were observed with higher glucose concentration in medium after 24 h of incubation. Almost similar number of attached cells was observed for low glucose concentrations on both studied materials.
Źródło:
Engineering of Biomaterials; 2017, 20, 141; 2-7
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of methods for the detection of low-abundant snoRNA-derived small RNAs in Saccharomyces cerevisiae
Autorzy:
Walkowiak, M.
Mleczko, A.M.
Bakowska-Zywicka, K.
Powiązania:
https://bibliotekanauki.pl/articles/80556.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2016, 97, 1
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fuzzy approach to complex system analysis
Autorzy:
Mazurkiewicz, J.
Nowak, K.
Walkowiak, T.
Powiązania:
https://bibliotekanauki.pl/articles/2069196.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
dependability
modelling
complex systems
fuzzy logic
Opis:
The paper presents a new approach to reliability and functional analysis of sophisticated complex systems using fuzzy logic. We propose to use such methodology since dependability parameters of the system are mostly approximated by experts instead of classical sources of data. Presented approach show different idea – modeling system using the unified structure – in functional sense. We assess the reliability of the system by accumulated down time. Fuzzy logic based reliability analysis, as well as Computer Information System and Discrete Transport System modeling and simulation are presented. Moreover, results of numerical experiment performed on a test case scenario related to the economic and functional aspects using proposed methodology are given. Fuzzy approach allows reducing the problem of assumptions of reliability distributions and – this way – seems to be very interesting for real systems management and tuning.
Źródło:
Journal of Polish Safety and Reliability Association; 2012, 3, 2; 169--178
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Heuristic algorithms for optimization of task allocation and result distribution in peer-to-peer computing systems
Autorzy:
Chmaj, G.
Walkowiak, K.
Tarnawski, M.
Kucharzak, M.
Powiązania:
https://bibliotekanauki.pl/articles/330970.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
system obliczeniowy P2P
przetwarzanie rozproszone
optymalizacja
heurystyka
algorytm ewolucyjny
P2P computing system
distributed computing
optimization
heuristics
evolutionary algorithms
Opis:
Recently, distributed computing system have been gaining much attention due to a growing demand for various kinds of effective computations in both industry and academia. In this paper, we focus on Peer-to-Peer (P2P) computing systems, also called public-resource computing systems or global computing systems. P2P computing systems, contrary to grids, use personal computers and other relatively simple electronic equipment (e.g., the PlayStation console) to process sophisticated computational projects. A significant example of the P2P computing idea is the BOINC (Berkeley Open Infrastructure for Network Computing) project. To improve the performance of the computing system, we propose to use the P2P approach to distribute results of computational projects, i.e., results are transmitted in the system like in P2P file sharing systems (e.g., BitTorrent). In this work, we concentrate on offline optimization of the P2P computing system including two elements: scheduling of computations and data distribution. The objective is to minimize the system OPEX cost related to data processing and data transmission. We formulate an Integer Linear Problem (ILP) to model the system and apply this formulation to obtain optimal results using the CPLEX solver. Next, we propose two heuristic algorithms that provide results very close to an optimum and can be used for larger problem instances than those solvable by CPLEX or other ILP solvers.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2012, 22, 3; 733-748
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
ILP modeling of many-to-many replicated multimedia communication
Autorzy:
Walkowiak, K.
Bulira, D.
Careglio, D.
Powiązania:
https://bibliotekanauki.pl/articles/308697.pdf
Data publikacji:
2013
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
ILP modeling
many-to-many communication
network optimization
replica location
Opis:
On-line communication services were evolving from a simple text-based chats towards sophisticated videopresence appliances. The bandwidth consumption of those services is constantly growing due to the technology development and high user and business needs. That fact leads us to implement optimization mechanisms into the multimedia communication scenarios. In this paper, the authors concentrate on many-to-many (m2m) communication, that is mainly driven by the growing popularity of on-line conferences and telepresence applications. An overlay model where m2m flows are optimally established on top of a given set of network routes is formulated and a joint model where the network routes and the m2m flows are jointly optimized. In the models, the traffic traverses through replica servers, that are responsible for stream aggregation and compression. Models for both predefined replica locations and optimized server settlement are presented. Each model is being followed by a comprehensive description and is based on real teleconference systems.
Źródło:
Journal of Telecommunications and Information Technology; 2013, 3; 56-65
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 41

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies