Wyniki wyszukiwania - BazTech

1

The Concept and Security Analysis of Wireless Sensor Network for Gas Lift in Oilwells

Bielecki B., Ksiezopolski B., Krajka A., Wierzbicki A.

Annales Universitatis Mariae Curie-Skłodowska. Sectio AI, Informatica

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2014

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Vol. 14, no. 2

76--85

EN

Pipelines, wellbores and ground installations are permanently controlled by sensors spread across the crucial points in the whole area. One of the most popular techniques to support proper oil drive in a wellbore is a Gas Lift. In this paper we present the concept of using wireless sensornetwork (WSN) in the oil and gas industry installations. Assuming that Gas Lift Valves (GLVs) in a wellbore annulus are sensor controlled, the proper amount of injected gas should be provided. In aground installation, the optimized amount of loaded gas is a key factor in the effcient oil production.This paper considers the basic foundations and security requirements of WSN dedicated to Gas Lift Installations. Possible attack scenarios and their influence on the production results are shown aswell.

2

On the modelling of Kerberos protocol in the Quality of Protection Modelling Language (QoP-ML)

Księżopolski B., Rusinek D., Wierzbicki A.

Annales Universitatis Mariae Curie-Skłodowska. Sectio AI, Informatica

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2012

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Vol. 12, no. 4

69--81

EN

The security modelling of IT systems is a very complicated task. One of the issues which must be analysed is the performance of IT systems. In many cases the guaranteed security level is too high in relation to the real threats. The overestimation of security measures can decrease system performance. The paper presents the analysis of Kerberos cryptographic protocol in terms of quality of protection performed by Quality of Protection Modelling Language (QoP-ML). The analysis concerns the availability attribute. In the article the Kerberos protocol was modelled and the QoP analysis of two selected versions was performed.

3

Mining online auction social networks for reputation and recommendation

Morzy M., Wierzbicki A., Papadopoulos A. N.

Control and Cybernetics

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2009

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Vol. 38, no 1

87-106

EN

Online auctions are quickly becoming one of the leading branches of e-commerce. Unfortunately, online auctions attract many fraudulent activities. Reputation systems are crucial for guaranteeing fairness of trade and reliability of service. Currently used reputation systems offer little protection from malevolent contractors. In this paper we present a new method for mining the reputation of sellers in online auctions. We devise two independent measures that assess reliability and questionability of sellers in parallel, leading to the concept of positive and negative reputation. To compute these measures we construct an S-graph which reflects the social linkage between sellers and buyers. We use both explicit and implicit feedbacks provided by auction participants, carefully identifying missing feedbacks that have been purposefully left out. Based on reputation estimates the community of online auction participants can detect misbehaving contractors and counteract fraud. Thus, the application of social information about reputation of contractors can be perceived as recommendations. Experimental evaluation of our proposal proves the feasibility and usefulness of the presented approach.

4

Rekrutacja kandydatów do Wyższej Szkoły Oficerskiej im. Tadeusza Kościuszki we Wrocławiu w latach 1994 - 2000

Wierzbicki A.

Zeszyty Naukowe / Wyższa Szkoła Oficerska Wojsk Lądowych im. gen. T. Kościuszki

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2007

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Nr 1

121-131

PL

W artykule przedstawiono wymagania stawiane współczesnym oficerom Sił Zbrojnych Rzeczpospolitej Polskiej. Przyblizono problematykę pozyskiwania i metody kwalifikowania kandydatów na zawodowych oficerów. Zaprezentowano wyniki badań empirycznych dotyczących kwalifikowania kandydatów do WySszej Szkoły Oficerskiej im. Tadeusza Kościuszki w przedziale czasowym od 1994 do 2000 r.

5

Fair and efficient network dimensioning with the reference point methodology

Goryczak W., Wierzbicki A., Milewski M.

Journal of Telecommunications and Information Technology

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2006

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nr 4

21-30

EN

The dimensioning of telecommunication networks that carry elastic traffic requires the fulfillment of two conflicting goals: maximizing the total network throughput and providing fairness to all flows. Fairness in telecommunication network design is usually provided using the so-called max-min fairness (MMF) approach. However, this approach maximizes the performance of the worst (most expensive) flows which may cause a large worsening of the overall throughput of the network. In this paper we show how the concepts of multiple criteria equitable optimization can be effectively used to generate various fair and efficient allocation schemes. We introduce a multiple criteria model equivalent to equitable optimization and we develop a corresponding reference point procedure for fair and efficient network dimensioning for elastic flows. The procedure is tested on a sample network dimensioning problem for elastic traffic and its abilities to model various preferences are demonstrated.

6

On multi-criteria approaches to bandwidth allocation

Ogryczak W., Wierzbicki A.

Control and Cybernetics

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2004

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Vol. 33, no 3

427-448

EN

Modern telecommunication networks face an increasing demand for services. Among these, an increasing number are services that can adapt to available bandwidth, and are therefore referred to as elastic traffic. Nominal network design for elastic traffic becomes increasingly significant. Typical resource allocation methods are concerned with the allocation of limited resources among competing activities so as to achieve the best overall performance of the system. In the network dimensioning problem for elastic traffic, one needs to allocate bandwidth to maximize service flows and simultaneously to reach a fair treatment of all the elastic services. Thus, both the overall efficiency (throughput) and the fairness (equity) among various services are important. In such applications, the so-called Max-Min Fairness (MMF) solution concept is widely used to formulate the resource allocation scheme. This approach guarantees fairness but may lead to significant losses in the overall throughput of the network. In this paper we show how the concepts of multiple criteria equitable optimization can be effectively used to generate various fair resource allocation schemes. We introduce a multiple criteria model ecluivalent to equitable optimization and we develop a corresponding reference point procedure to generate fair efficient bandwidth allocations. The procedure is tested on a sample network dimensioning problem and its abilities to model various preferences are demonstrated.

7

Rola telekomunikacji w kształtowaniu społeczeństwa informacyjnego

Wierzbicki A.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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2003

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nr 4

157-160

PL

Omówiono rolę telekomunikacji, technik informacyjnych i infrastruktury teleinformatycznej, zwanej też informacyjną, w procesie kształtowania się społeczeństwa informacyjnego i gospodarki opartej na wiedzy w Unii Europejskiej. Przedstawiono podejście strategiczne Unii Europejskiej do tych zagadnień, włącznie z wizją Ambient Intelligence nowej wielkiej generacji infrastruktury teleinformatycznej. Skoncentrowano się na strategii poakcesyjnej Polski w tym zakresie oraz omówiono specyficzne szanse Polski.

EN

Role of telecommunications, information technology and teleinformatic infrastructure, called also information infrastructure in development process of information society and knowledge-based economy in European Union is described. Strategic attitude of European Union to aforementioned issues including Ambient Intelligence 's vision of new generation teleinformatic infrastructures is presented. Post-accession strategy of Poland concerning this issues is presented more details and specific chances for Poland are discussed.

8

Fair resource allocation schemes and network dimensioning problems

Ogryczak W., Śliwiński T., Wierzbicki A.

Journal of Telecommunications and Information Technology

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2003

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nr 3

34-42

EN

Resource allocation problems are concerned with the allocation of limited resources among competing activities so as to achieve the best overall performances of the system but providing fair treatment of all the competitors. Telecommunication networks are facing the increasing demand for Internet services. Therefore, a problem of network dimensioning with elastic traffic arises which requires to allocate bandwidth to maximize service flows with fair treatment of all the services. In such applications, the so-called max-min fairness (MMF) solution concept is widely used to formulate the resource allocation scheme. This guarantees the fairness but may lead to significant losses in the overall throughput of the network. In this paper we show how multiple criteria optimization concepts can be used to generate various fair resource allocation schemes. The solution concepts are tested on the network dimensioning problem and their abilities to model various preferences are demonstrated.

9

Parallel approaches to parametric optimization and the convergence of interactive decision support

Wierzbicki A.

Control and Cybernetics

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2000

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Vol. 29, no 1

427-444

EN

In the perspective of parallel processing, a new sense of parametric optimization might be promoted. The paper shows that it, is possible to propose new parallel versions of basic optimization algorithms, as well as an advanced method of securing convergence in interactive mnltiobjective optimization and decision support, all based on a modified concept of parametric embedding. This general idea is exemplified for the case of the simplex algorithm of linear programming by a parameterized and coarse-grain parallel augmented simplex algorithm, where a linear optimization problem can be embedded into a multiple-ohjective family which introduces diversified directions of search cutting through the interior of the original admissible set. For the case of nonlinear programming, a parameterized and coarse-grain parallel variable metric pulsar algorithm is shortly presented, where parallel directional searches are combined with a parametrized variable metric to produce a pulsating, robust nonliear programming algorithm. These two examples concern very basic optimization tools ; at the other end of the spectrmn of optimization-related methods, a general method called outranking trials of securing convergence of interactive multiobjective optimization and decision suport is obtained through parameterizing an outranking relation and using basic properties of order-consistent achievement functions in reference point methodology for testing the existence of outranking points by parallel optimization runs. Thus, the paper presents the use of parallel processing to solve a wide range of modified parametric embedding problems related to optimization and decision support.

10

Polska na drodze do społeczeństwa informacyjnego w początku XXI wieku

Wierzbicki A.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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1998

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nr 4

221-228

PL

Przedstawiono wyzwania, związane z początkiem epoki cywilizacji informacyjnej oraz wnioski dotyczące polityki rozwojowej w Polsce, a zwłaszcza polityki badawczej w dziedzinie szeroko rozumianej telekomunikacji.

EN

The paper presents challenges resulting from the beginning of the era of information civilization and conclusions concerning the corresponding development strategy in Poland, in particular the necessary research strategy in the field of broadly understood telecommunicaion.