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Wyniki wyszukiwania dla: METHOD OF LINES
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Method of lines for physiologically structured models with diffusion
PublikacjaWe deal with a size-structured model with diffusion. Partial differential equations are approximated by a large system of ordinary differential equations. Due to a maximum principle for this approximation method its solutions preserve positivity and boundedness. We formulate theorems on stability of the method of lines and provide suitable numerical experiments.
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Method of lines for Hamilton-Jacobi functional differential equations.
PublikacjaInitial boundary value problems for nonlinear first order partial functional differential equations are transformed by discretization in space variables into systems of ordinary functional differential equations. A method of quasi linearization is adopted. Suffcient conditions for the convergence of the method of lines and error estimates for approximate solutions are presented. The proof of the stability of the diffrential difference...
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Method of lines for nonlinear first order partial functional differential equations.
PublikacjaClassical solutions of initial problems for nonlinear functional differential equations of Hamilton--Jacobi type are approximated by solutions of associated differential difference systems. A method of quasilinearization is adopted. Sufficient conditions for the convergence of the method of lines and error estimates for approximate solutions are given. Nonlinear estimates of the Perron type with respect to functional variables...
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Generalized method of lines for nonlinear first order partial differential equations
PublikacjaKlasyczne rozwiązania zagadnień początkowych oraz początkowo brzegowych są przybliżane za pomocą rozwiązań równań różniczkowo różnicowych. Skonstruowana jest metoda prostych polegająca na dyskretyzacji wyjściowego równania względem zmiennych przestrzennych. Przedstawiony w pracy schemat bazuje na metodzie linearyzacji dla zagadnień nieliniowych. W pracy zastosowano metodę quasilinearyzacji polegającą na zamianie nieliniowego równania...
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Numerical method of lines for first order partial differential functional equations
PublikacjaUdowodniono zbieżność numerycznej metody prostych dla równań różniczkowofunkcyjnych o pochodnych cząstkowych pierwszego rzędu i ich rozwiązań klasycznych określonych na piramidzie Haara. Zastosowano metodę nierówności różniczkowych.
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Numerical method of lines for first order partial differential equations with deviated variables
PublikacjaPraca traktuje o przybliżaniu rozwiązań klasycznych równańróżniczkowo-funkcyjnych cząstkowych pierwszego rzędu rozwiązaniamiukładów quasiliniowych równań różnicowych. Nowe podejście dorozwiązywania równań nieliniowych zawdzięczamy metodziequasilinearyzacji dla zagadnień początkowo - brzegowych z odchylonymargumentem. Dla przyrostów pochodnych funkcji danej zakładamy nieliniowe oszacowanie typu Perrona. Załączone są wyniki eksperymentów...
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The iterative method in search for the state of equilibrium in anchor lines.
PublikacjaPrzedstawiono iteracyjną metodę rozwiązywania równań równowagi lin kotwicznych. Metoda jest szczególnie łatwa do zaprogramowania obliczeń numerycznych, ponieważ w każdym kroku iteracyjnym wymaga jedynie obliczania całek oznaczonych znanych funkcji. Wynikiem obliczeń są wartości sił podłużnych w linie i jej kształt, który na skutek oddziaływania prądu oceanicznego na linę może być krzywą przestrzenną. Przytoczone przykłady...
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Structural reliability of overhead power lines by means of Monte Carlo Method and RSM
PublikacjaThe article discusses the issue of reliability assessment of overhead power lines by means of both Monte Carlo Method and Response Surface Method. The suspension tower OS24 ON150+10 is considered, as the weakest element of the line. A comparison is made between deterministic and probabilistic approaches to wind and icing loading. The PDFs for wind and icing loads are proposed. Reliability is assessed for both critical atmospheric...
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Comments on ''An innovative fast powerful method for tackling electromagnetic eigenvalue problems for multistrip transmission lines''
PublikacjaPraca stanowi komentarz do publikacji Casanuevy i Garcii dotyczącej techniki szybkiego obliczania charakterystyk dyspersyjnych falowodów z niejednorodnym wypełnieniem. Zwrócono uwagę na niepotrzebną komplikację zagadnienia poprzez zastosowanie techniki rozkładu na wartości szczególne.
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GTM Method of Structural Studies Lecture and Laboratory
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THE APPLICATION EFFECTS OF CONTINUOUS SATELLITE MEASUREMENTS OF RAILWAY LINES
PublikacjaThe paper presents results of satel lite surveying of the railway's rout es, which have been conducted just after starting in Poland (in 2008) the Active Geodesy Network ASG-EU POS. Afterwards it was possible to effectively utilize the GNSS survey ing results for the inventory of the (exploring) railways in service. Already at the beginning of 2009, the research team from Gdansk University of Technology and Naval Academy in Gdynia,...
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Simulation of Signal Propagation Along Fractional-Order Transmission Lines
PublikacjaIn this paper, the simulation method of signal propagation along fractional-order (FO) transmission lines is presented. Initially, fractional calculus and the model of FO transmission line are introduced. Then, the algorithm allowing for simulation of the nonmonochromatic wave propagation along FO transmission lines is presented. It employs computations in the frequency domain, i.e., an analytical excitation is transformed to the...
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Calculations of Short-Circuit Current Flows in Earth Wires of HV Lines
PublikacjaThis paper presents a method which enables calculating flows of short-circuit currents in earth wires of high voltage transmission lines, and its implementation in the form of a computer programme. The algorithm enables performing calculations for a double-fed line and starconnected lines (three terminal lines). The developed programme enables verifying dimensioning of earth wires in the context of their short-circuit thermal withstand...
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Design of power cable lines partially exposed to direct solar radiation – special aspects
PublikacjaPower cable lines are usually buried in the ground. However, in some cases, their ending sections are mounted along the supports of overhead lines. This leads to a situation where the cables are exposed to direct solar radiation and, consequentially, overheat. The paper presents the advanced computer modelling of power cables’ heating, considering their insolation as well as the effect of wind. The temperature and current-carrying...
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Computer-Aided Calculations of Earth Potential Rise in High Voltage Overhead Lines
PublikacjaHigh voltage overhead power lines with earth wires comprise towers made of conductive material. Some towers are in locations where people can be expected to be either for a long time or for a short time but very frequently. Evaluation of shock hazard near such towers requires calculation of line-to-earth short-circuit current, earth current and especially earth potential rise. Number of towers in high voltage power lines can exceed...
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Experimental Comparison of Straight Lines and Polynomial Interpolation Modeling Methods in Ship Evolutionary Trajectory Planning Problem
PublikacjaPaper presents the application of evolutionary algorithms and polynomial interpolation in ship evolutionary trajectory planning method and its comparison to classic approach, where trajectory is modeled by straight lines. Evolutionary algorithms are group of methods that allows\ to find a collision free trajectory in real time, while polynomial interpolation allows to model smooth trajectory, which keeps continuity of velocity...
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Modelling of MV and HV Cable Lines
PublikacjaOverhead and cable lines are fundamental elements of power systems. Participation of cable lines is smaller and their percentage decreases as voltage is increased. HV cable lines are often built with the use of cables which are composed of coaxial metallic sheaths. Such cables are also often used in MV networks. The sheath may operate in different confgurations. In the case of Polish MV network the sheaths are earthed at both ends....
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EFFICIENT LINE DETECTION METHOD BASED ON 2D CONVOLUTION FILTER
PublikacjaThe article proposes an efficient line detection method using a 2D convolution filter. The proposed method was compared with the Hough transform, the most popular method of straight lines detection. The developed method is suitable for local detection of straight lines with a slope from -45˚ to 45˚. Also, it can be used for curve detection which shape is approximated with the short straight sections. The new method is characterized...
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Resonance problems in UHV transmission lines
PublikacjaThe paper presents resonance phenomena observed in 400 kV transmission lines in the Polish power system. Two events are analysed, when shunt reactors used for reactive power compensation, caused overvoltages and overcurrent protection tripping as a result of resonance. An oscillographic fault recordings from protection devices are compared to time domain simulation results. The obtained simulation results match fault recordings,...
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Ruling lines removal in handwritten documents
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Ferrite coupled slot lines circulator.
PublikacjaW oparciu o metodę rodzajów sprzężonych przeprowadzono analizę macierzy rozproszenia sekcji ferrytowych linii szczelinowych (FLS). W oparciu o uzyskane wyniki opracowano model cyrkulatora zaprojektowany w postaci kaskadowego połączenia sekcji FLS oraz szczelinowego rozgałęzienia typu T. Określono parametry rozproszenia układu, które zweryfikowano eksperymentalnie.
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Analysis of Corrugated Coaxial Line with the Use of Body of Revolution and Finite Element Method
PublikacjaA combination of the body-of-revolution and finite element methods is utilized to the analysis of coaxial lines with corrugated rod and wall. Both periodic and non-periodic structures can be investigated. As the structure is axially symmetrical the two dimensional scalar-vector finite element method can be used, which allows for the investigation of complex geometries and is computationally efficient. A generalized impedance matrix...
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Structural Health Monitoring of Overhead Power Transmission Lines
PublikacjaStructural Health Monitoring (SHM) is a novel and continuously developing branch of science and technology that draws attention of scientists all over the world. It creates opportunities to detect, localize and identify structural damage of various types such as: line breakage, permissible sag, bolt loosening, fatigue cracking or insulator contamination. On the other hand the methods used to estimate the remaining operational...
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Treatment of the three strip coplanar lines on the ferrite
PublikacjaW pracy przedstawiono badania koplanarnej linii paskowej złożonej z trzech pasków umieszczonych na podłużnie magnesowanym podłożu ferrytowym. W analizie badanej linii zastosowano metodę spektralną oraz metodę rodzajów sprzężonych. Współczynniki sprzężenia żyromagnetycznego oraz charakterystyki dyspersyjne zostały określone przy użyciu obu metod.
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On the characteristic impedance definition in microstrip and coplanar lines
PublikacjaW niniejszej pracy rozważono definicję impedancji charakterystycznej dla bezstratnych linii mikropaskowych i koplanarnych. Wykazano, że ze względu na znaczne wartości prądu przesunięcia związanego z podłużną składową pola elektrycznego, definicja impedancji staje się niejednoznaczna. W rezultacie może to przyczyniać się do istotnych błędów powstających już na etapie projektowania układów. Pokazano, iż efekt ten jest szczególnie...
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Stark effect of atomic helium singlet lines
PublikacjaWe present experimental and theoretical investigations of the He spectral series 2S1−nQ1 (n=3÷9, Q=S,P,D,…,n−1) and 2P1−nQ1 (n=3÷9, Q=S,P,D,…,n−1) in electric fields up to 1635 kV/cm. Apart from the allowed transitions with |ΔL|=1, the transitions with |ΔL|=0,2,3,…-without field strictly forbidden-were observed. Several He patterns become similar to hydrogen patterns, which means they are nearly symmetric and show in higher fields...
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Isolator using a ferrite-coupled-lines gyrator
PublikacjaPrzedstawiono koncepcję nowego typu gyratora wykonywanego poprzez zwarcie lub rozwarcie ferrytowych linii sprzężonych (FCL). Redukując w taki sposób macierz rozproszenia (S) sekcji FCL określono macierz S gyratora oraz procedurę jego projektowania. Poprzez odpowiednie wprowadzenie warstwy rezystywnej do układu gyratora zaprojektowano nowy układ isolatora typu FCL oraz podano metodykę jego projektowania. Koncepcje proponowanych...
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Analysis of measurement uncertainty for contact-less method used to measure the position of catenary contact wire, performed with the use of Monte Carlo method
PublikacjaCurrently the majority of main railway lines in Europe are electrified, and electric trains have the biggest share in the entire amount of rail transport. Reliability of electrified railways is closely related to the issue of supplying traction vehicles with energy. The problems connected with diagnostics of energy consumption node, namely the contact line and the current collector, are therefore of fundamental importance for maintaining...
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Isotope shifts of multipole lines of Pb I and Pb II
PublikacjaStudies of isotope shifts of three multipole lines between levels of the ground configuration 6s26p2 of Pb I, i.e.: 461.9 nm(1S0→3P1), 531.5 nm(1S0→3P2) and 733.2 nm(1D2→3P1), as well as 710.2 nm line (6s26p2P3∕2→6s26p2P1∕2) of Pb II are presented. We determined the isotope shifts between four stable isotopes: 204, 206, 207, 208. By the use of King plot analysis we were able to separate the mass and the field shifts. We found that...
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Cross-Bonding of MV Cable Lines for Energy Losses Decrease
PublikacjaCurrently, almost all medium voltage cable lines (MV) operate with the return wires earthed at both ends of the cable. Such a way of operation causes that during normal states of operation as well as during disturbances, e.g. short-circuits, in the return wires induce currents whose values mainly depend on the currents flowing in the phase wires. These currents in normal operating states are a source of additional energy losses...
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Hyperfine Structure Study of Several Lines of207Pb I
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The effectiveness of chemotherapy and electrochemotherapy on ovarian cell lines in vitro
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Impulse Measurements of Tower Earthings of Overhead Transmission Lines
PublikacjaPrzepisy wymagają okresowego badania uziemień słupów elektroenergetycznych linii przesyłowych. pomiary takie metodami klasycznymi niskiej częstotliwości wymagają odłączania uziomów od konstrukcji słupa, co wiąże się z wyłączaniem linii. wykorzstanie metody udarowej do oceny uziemień nie wymaga odłączania uziomów i może byc przeprowadzane podczas pracy linii.
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Modernization of tram lines with the use of railway design standards
PublikacjaThe article presents the main differences between the process of upgrading railway and tram routes. Geometrical layout designing is an issue of the interest. Railway designing rules that may be helpful in the design of the modernization are specified.
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Nonreciprocity of a ferrite coupled microstrip-slot lines junction
PublikacjaW oparciu o wyniki modelowania numerycznego zbadano efekty niewzajemne występujące w strukturze sekcji sprzężonych poprzez warstwę ferrytu linii mikropaskowej i szczelinowej. Wykazano występowanie zjawiska periodycznej transformacji energii rodzaju mikropaskowego w rodzaj szczelinowy i odwrotnie.
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The contactless method of chip-to-chip high-speed data transmission monitoring
PublikacjaThis paper presents a technique of decoupling differential signals transmitted in a pair of microstrip lines on a printed circuit board (PCB), using dedicated coupler for high speed data transmission monitoring in chip-to-chip interconnections. The coupler used for signal probing is overlayed on the pair of microstrip lines under test, and provides a signal to the next blocks of the measurement system without disturbing transmission...
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Verification of a Novel Method of Detecting Faults in Medium-Voltage Systems with Covered Conductors
PublikacjaThis paper describes the use of new methods of detecting faults in medium-voltage overhead lines built of covered conductors. The methods mainly address such faults as falling of a conductor, contacting a conductor with a tree branch, or falling a tree branch across three phases of a medium-voltage conductor. These faults cannot be detected by current digital relay protection systems. Therefore, a new system that can detect the...
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Investigation of multilayer three-strip coplanar lines with the ferrite material
PublikacjaW artykule opisano wyniki badań przeprowadzonych nad wielowarstwową linią koplanarną zawierającą trzy paski umieszczone na podłużnie magnesowanym ferrycie. Analiza opiera się o metodę rodzajów sprzężonych. Uzyskane rezultaty zostały zweryfikowane eksperymentalnie.
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Investigation of hyperfine structure of several major lines in PbI and PbII
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The Issues of Reactive Power Compensation in High-voltage Transmission Lines
PublikacjaThis paper discusses the selection of compensation shunt reactors for a double-circuit 400 kV transmission line using the example of the newly built Elk Bis – Alytus transmission line. The analysis takes into account various conditions of the power system. The published results relate to voltage levels in steady states and during switching processes and short circuits.
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Nonreciprocal Devices Utilizing Longitudinally Magnetized Ferrite Coupled Lines
PublikacjaThis chapter presents authors’ recent research on the nonreciprocal devices utilizing longitudinally magnetized ferrite coupled line (FCL) junction. The principle of operation of FCL junction is explained and the hybrid techniques of analysis are shown. Numerical and experimental results concerning the nonreciprocal devices utilizing the different configurations of FCL junctions are presented and discussed.
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Practical application of in motion charging: Trolleybuses service on bus lines
PublikacjaNight charging and fast charging are currently the two most common systems for charging electric buses. Despite the fact that numerous trial installations were started, neither of these two systems has obtained unqualified approval of the users. The alternative is to charge vehicles in motion (the so-called In Motion Charging), which combines the advantages of trolleybus transport and of electric buses: the main supply source are...
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Nonreciprocal components using junction of a ferrite coupled microstrip lines
PublikacjaW oparciu o wyniki modelowania numerycznego zbadano efekty niewzajemne występujące w złączach ferrytowych linii sprzężonych. Opracowano metodyki projektowania złączy w technice linii mikropaskowej dla realizacji ferrytowych układów niewzajemnych. Przeprowadzono symulację parametrów transmisyjnych szeregu układów niewzajemnych wykonanych techniką zintegrowaną.
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A new approach to cross-bonding in medium voltage cable lines
PublikacjaThe medium voltage underground cable sheaths are usually bonded and earthed in every substation on the cable route. This results in additional power losses in the sheaths. The paper presents an idea of reducing power losses caused by sheaths cross-bonding. The idea of sheaths cross-connecting only in selected MV/LV substations is given instead of a typical solution, where sheaths cross-bonding requires installing additional joints...
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An Analysis of Multistrip Line Configuration on Elliptical Cylinder
PublikacjaA configuration of multistrip lines mounted on a multilayer dielectric coated elliptic cylinder is investigated in this paper. A full-wave analysis and a moment-method calculation are employed. The analysis is carried out considering the expansion of the field as a series of Mathieu functions. Both open and shielded lines are considered in the analysis. Propagation coefficients and characteristic impedances are calculated for the...
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EHV transmission lines wires location on line operation issues - case studies
PublikacjaTransmission lines towers construction affects the line parameters and influences on its operation in the future. Misguided design of the tower can lead to serious problems such as overvoltages, electric arc extinction difficulties, voltage asymmetry, resonance phenomena or increasing of magnetic field near the line. The paper points out those threats on example of 400 kV double circuit overhead transmission line with shunt reactors....
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Revealing the epigenetic effect of temozolomide on glioblastoma cell lines in therapeutic conditions
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P04.06 Temozolomide influence on global DNA methylation in glioblastoma cell lines
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Hyperfine Structure Study of Several Lines of207Pb I – Part II
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The E2 admixtures in mixed forbidden lines of Bi I and Pb I
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