Temat: problems - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Foundations of the theory of open waveguides
Autorzy:: Nosich, A.I.
Powiązania:: https://bibliotekanauki.pl/articles/308738.pdf
Data publikacji:: 2000
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: open waveguide theory
eigenvalue problems
Opis:: The theory of electromagnetic wave eigenmodes propagating on open dielectric and metallic waveguides has been reviewed. The main steps of different theoretical approaches to the problem are outlined and discussed. The unsolved problems and also directions of future development are pointed out.
Źródło:: Journal of Telecommunications and Information Technology; 2000, 1-2; 42-45
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Advanced Inversion Techniques for Ground Penetrating Radar
Autorzy:: Fedeli, A.
Pastorino, M.
Randazzo, A.
Powiązania:: https://bibliotekanauki.pl/articles/308896.pdf
Data publikacji:: 2017
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: electromagnetic scattering
Ground Penetrating Radar
inverse problems
Opis:: Ground Penetrating Radar (GPR) systems arenowadays standard inspection tools in several application areas, such as subsurface prospecting, civil engineering and cultural heritage monitoring. Usually, the raw output of GPR isprovided as a B-scan, which has to be further processed inorder to extract the needed information about the inspectedscene. In this framework, inversescattering-based approachesare gaining an ever-increasing interest, thanks to their capabilities of directly providing images of the physical and dielectricproperties of the investigated areas. In this paper, some advances in the development of such inversion techniques in theGPR field are revised and discussed.
Źródło:: Journal of Telecommunications and Information Technology; 2017, 3; 37-42
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: A proposition to exploit the partially linear structure of the nonlinear multicommodity flow optimization problem
Autorzy:: Białoń, P.M.
Powiązania:: https://bibliotekanauki.pl/articles/309255.pdf
Data publikacji:: 2002
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: multicommodity flow problem
projection methods
large nonlinear problems
Opis:: Optimization problems arising in telecommunications are often large-scale nonlinear problems. Usually their big size is generated mainly by their linear parts but the existence of small or medium nonlinear parts prevents us from directly tackling them with linear solvers, which are efficient. Instead, the author has proposed a method to decompose big nonlinear problems into nonlinear and linear parts. Its coordination procedure uses two auxiliary solvers: quadratic and pure nonlinear. The procedure falls in the class of projection methods. Special cuts proposed by the author allow to avoid an excessive zigzagging while not enormously increasing the complexity of both the parts. The validity of these cuts can be analyzed within the framework of obtuse cone model. Here the author summarizes the method and analyses its applicability to nonlinear multicommodity flow problems. The structure and particular sizes of this problem make the method useful. The considerations are illustrated by a numerical example with a multicommodity flow problem
Źródło:: Journal of Telecommunications and Information Technology; 2002, 3; 49-56
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: A note on the computation of ordered supported non-dominated solutions in the bi-criteria minimum spanning tree problems
Autorzy:: Silva, C. G.
Cli'maco, J. C. N.
Powiązania:: https://bibliotekanauki.pl/articles/308580.pdf
Data publikacji:: 2007
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: minimum spanning tree
supported non-dominated solutions
combinatorial problems
Opis:: This paper presents a new procedure for computing the set of supported non dominated solutions of bi-criteria minimum spanning tree problems in ordered manner. The procedure is based on the systematic detection of edges which must be replaced in one efficient solution to obtain the adjacent one, in the criteria space. This new approach avoids solving unnecessary problems and makes use of previous computations.
Źródło:: Journal of Telecommunications and Information Technology; 2007, 4; 11-15
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Military route planning in battlefield simulation: effectiveness problems and potential solutions
Autorzy:: Tarapata, Z.
Powiązania:: https://bibliotekanauki.pl/articles/309343.pdf
Data publikacji:: 2003
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: battlefield simulation
route planning
shortest paths
effectiveness problems
computational complexity
Opis:: Path searching is challenging problem in many domains such as simulation war games, robotics, military mission planning, computer generated forces (CGF), etc. Effectiveness problems in military route planning are related both with terrain modelling and path planning algorithms. These problems may be considered from the point of view of many criterions. It seems that two criterions are the most important: quality of terrain reflection in the terrain model and computational complexity of the on(off)-line path planning algorithm. The paper deals with two above indicated problems of route planning effectiveness. Comparison of approaches used in route planning is presented. The hybrid, terrain merging-based and partial path planning, approach for route planning in dynamically changed environment during simulation is described. It significantly increase effectiveness of route planning process. The computational complexity of the method is given and some discussion for using the method in the battlefield simulation is conducted. In order to estimate how many times faster we can compute problem for finding shortest path in network with n big squares (b-nodes) with relation to problem for finding shortest path in the network with V small squares (s-nodes) acceleration function is defined and optimized.
Źródło:: Journal of Telecommunications and Information Technology; 2003, 4; 47-56
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Network Dimensioning with Maximum Revenue Efficiency for the Fairness Index
Autorzy:: Zalewski, G.
Ogryczak, W.
Powiązania:: https://bibliotekanauki.pl/articles/307749.pdf
Data publikacji:: 2016
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: allocation problem
decision problems
dimensioning networks
fair-optimization
linear programming
maximization
multi-criteria
Opis:: Network dimensioning is a specific kind of the resource allocation problem. One of the tasks in the network optimization is to maximize the total flow on given pairs of nodes (so-called demands or paths between source and target). The task can be more complicated when different revenue/profit gained from each unit of traffic stream allocated on each demand is taken into account. When the total revenue is maximized the problem of starvation of less attractive paths can appear. Therefore, it is important to include some fairness criteria to preserve connections between all the demands on a given degree of quality, also for the least attractive paths. In this paper, a new bicriteria ratio optimization method which takes into account both, the revenue and the fairness is proposed. Mathematical model is built in a form of linear programming. The solutions are analyzed with some statistical measures to evaluate their quality, with respect to fairness and efficiency. In particular, the Gini’s coefficient is used for this purpose.
Źródło:: Journal of Telecommunications and Information Technology; 2016, 4; 15-21
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: New Developments in a Two-criteria Approach to Dynamic Power Management in Energy-aware Computer Networks
Autorzy:: Karbowski, A.
Jaskóła, P.
Powiązania:: https://bibliotekanauki.pl/articles/309427.pdf
Data publikacji:: 2016
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: data-intensive computing
energy-aware network
energy-aware routing
dynamic power management
MIQP problems
traffic engineering
Opis:: In the paper authors continue the development of a model of dynamic power management in energy-aware computer networks, where two criteria: energy consumption and the quality of service are considered. This approach is appropriate when the routing problem with fixed demands is inadmissible. The formulation introducing edge indices is modified and tests on problems of different sizes are performed.
Źródło:: Journal of Telecommunications and Information Technology; 2016, 2; 21-25
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Distortion and noise problems of subcarrier multiplexed optical systems
Autorzy:: Udvary, E.
Marozsák, T.
Powiązania:: https://bibliotekanauki.pl/articles/309132.pdf
Data publikacji:: 2001
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: łączność bezprzewodowa
komunikacja bezprzewodowa
szumy
zakłócenia
zniekształcenia
wireless communications
distortion and noise problems
subcarrier multiplexed optical subsystems
Opis:: In this paper investigation of subcarrier multiplexed optical subsystems for optically supported communication systems is presented. Noise and spurious free dynamic range are the main parameters, which are determined by the applied optical transmission. The frequency dependence of these parameters and optimal frequency chosen is presented.
Źródło:: Journal of Telecommunications and Information Technology; 2001, 4; 60-64
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Comparison of Selected Fair-optimization Methods for Flow Maximization between Given Pairs of Nodes in Telecommunications Network
Autorzy:: Zalewski, G.
Ogryczak, W.
Powiązania:: https://bibliotekanauki.pl/articles/308874.pdf
Data publikacji:: 2016
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: allocation problem
decision problems
fair-optimization
linear programming
multi-criteria
networks
ordered weighted averaging
OWA
reference point method
RPM
Opis:: Dimensioning of telecommunications networks requires the allocation of the ows (bandwidth) to given trac demands for the source-destination pairs of nodes. Unit ow allocated to the given demand is associated with revenue that may vary for dierent demands. Problem the decision-making basic algorithms to maximize the total revenue may lead to the solutions that are unacceptable, due to "starvation" or "locking" of some demand paths less attractive with respect to the total revenue. Therefore, the fair optimization approaches must be applied. In this paper, two fair optimization methods are analyzed: the method of ordered weighted average (OWA) and the reference point method (RPM). The study assumes that ows can be bifurcated thus realized in multiple path schemes. To implement optimization model the AMPL was used with general-purpose linear programming solvers. As an example of the data, the Polish backbone network was used.
Źródło:: Journal of Telecommunications and Information Technology; 2016, 3; 18-24
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: The Kummer confluent hypergeometric function and some of its applications in the theory of azimuthally magnetized circular ferrite waveguides
Autorzy:: Georgiev, G. N.
Georgieva-Grosse, M. N.
Powiązania:: https://bibliotekanauki.pl/articles/309046.pdf
Data publikacji:: 2005
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: microwave propagation in anisotropic media
microwave guides and components
ferrite phase shifters
switches
isolators
eigenvalue problems
function-theoretic and computational methods in electromagnetic theory
theoretical and numerical analysis of special functions
Opis:: Examples of the application of the confluent hypergeometric functions in miscellaneous areas of the theoretical physics are presented. It is suggested these functions to be utilized as a universal means for solution of a large number of problems, leading to: cylindrical, incomplete gamma, Coulomb wave, Airy, Kelvin, Bateman, Weber's parabolic cylinder, logarithmic-integral and exponential integral functions, generalized Laguerre, Poisson-Charlier and Hermit polynomials, integral sine and cosine, Fresnel and probability integrals, etc. (whose complete list is given), which are their special cases. The employment of such an approach would permit to develop general methods for integration of these tasks, to generalize results of different directions of physics and to find the common features of various phenomena, governed by equations, pertaining to the same family. Emphasis is placed here on the use of the Kummer function in the field of microwaves: the cases of normal and slow rotationally symmetric TE modes propagation in the azimuthally magnetized circular ferrite waveguide are considered. Lemmas on the properties of the argument, real and imaginary parts, and positive purely imaginary (real) zeros of the function mentioned in the complex (real) domain, of importance in the solution of boundary-value problem stated for normal (slow) waves, are substantiated analytically or numerically. A theorem for the identity of positive purely imaginary and real zeros of the complex respectively real Kummer function for certain parameters, is proved numerically. Tables and graphs support the results established. The terms for wave transmission are obtained as four bilaterally open intervals of variation of the quantities, specifying the fields. It turns out that the normal (slow) modes may exist in one (two) region(s). The theoretically predicted phase curves for the first waves of the two TE sets examined show that the structure explored is suitable for ferrite control components design.
Źródło:: Journal of Telecommunications and Information Technology; 2005, 3; 112-128
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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