Rozprawy doktorskie (dostęp otwarty)

Permanent URI for this collectionhttps://repo.agh.edu.pl/handle/AGH/43120

Zbiór rozpraw doktorskich bronionych w Akademii i gromadzonych w Bibliotece Głównej AGH jest wyjątkową kolekcją z dziedziny nauk inżynieryjno-technicznych, nierozerwalnie związaną z procesem naukowym i badawczym Uczelni i historią edukacji technicznej w Polsce. Kolekcji rozpraw liczącej obecnie ponad 6000 tytułów, dała początek praca inżyniera górnictwa, późniejszego profesora i Rektora Akademii Górniczo-Hutniczej Witolda Budryka pt. „Ruch podsadzki płynnej w rurociągach zamulaniowych”. W dniu 10 września 1928 r. Senat Uczelni nadał Witoldowi Budrykowi, jako pierwszemu w Polsce, tytuł doktora nauk technicznych z zakresu górnictwa. W kolekcji znajdują się między innymi prace profesorów: Andrzeja Bolewskiego, Henryka Góreckiego, Jerzego Grzymka, Franciszka Nadachowskiego. Wśród nich są rozprawy dostępne online w Repozytorium AGH oraz w sposób otwarty jedynie na terminalach komputerowych w Czytelni Oddziału Zbiorów Specjalnych BG AGH.

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Access status: Open Access ,
Określanie warunków elektrochemicznego otrzymywania $ZnSe$ z roztworów wodnych
(2003-03-11) (Data obrony: 2006) Kowalik, Remigiusz
Wydział Metali Nieżelaznych
The II-VI wide band-gap semiconductors are very interesting materials because of their potential application in electronic devices like electroluminescence diodes, lasers or light detectors. They can be used in producing data storage devices, display devices or multijunction solar cells. There are many methods for the preparation of these materials. Electrodeposition has been found to be a very good method to fabricate thin films of compound semiconductors. It is low-cost and simple method with many advantages as: possibility of a deposition on large surface areas (even irregular), and assures precise control of this process by adjusting several parameters. The main goal of this work is to analyze the mechanism and kinetics of the electrosynthesis of zinc selenide by electrochemical process from aqueous solution. The voltammetric, hydrodynamic and electrogravimetric measurements were carried out under following condition: concentration of $ZnSO_{4} \; \; 0,1-0,8 \; mol/dm^{3}, \; H_{2}SeO_{3} \; 0,001-0,008 \; mol/dm^{3}, \; pH=2$, temperature 25-75°C. Subsequently process of deposition was carry out under potentiostatic conditions. The influence of deposition potential, the composition and temperaturę of the electrolyte on the stoichiometry composition and morphology of the obtained deposits were examined.
Access status: Open Access ,
Poziomy teras fluwialnych jako zapis ewolucji dolin Kamienicy i Ochotnicy w Gorcach
(2004-03-29) (Data obrony: 2006) Olszak, Janusz
Wydział Geologii, Geofizyki i Ochrony Środowiska
Seven levels of fluvial terraces, of Pleistocene and Holocene age, are present in the Kamienica and Ochotnica valleys. The oldest terraces date from the Sanian 1 cold stage and they lie at the heights of up to 74 m above the present river channel. The fluvial terraces in the Kamienica and Ochotnica valleys record both, tectonic uplift and Pleistocene climatic oscillations. The presence of strath terraces, some of them of Holocene age, indicates permanent uplift of the area throughout the Quaternary. The valleys were deepening mainly during transitional glacial-interglacial periods, and less intensely during the interglacial-glacial transitions and interglacial periods. Aggradation took place in glacial and partly in interglacial periods. The valleys widened, with formation of the strath terraces, mainly during the interglacial periods. A general tendency to narrowing of the valley bottoms has prevailed since Mezopleistocene time, but not every phase in the evolution of the valleys resulted in narrower valleys bottoms. The average rate of incising for both valleys since middle Pleistocene was calculated at ca. 0.2 mm/year. The rate of incision was greatest at the transitional stages and in Eemian and Holocene. The valleys differed in the amount of incision at individual stages of their evolution and the most distinct difference is marked since the Eemian until now. In this time the lowest part Ochotnica Valley deepened more than twice the value for corresponding part of the Kamienica valley. This seems to be a result of different rates of neotectonic uplift.
Access status: Open Access ,
Własności magnetyczne układów niejednorodnych w modelu Isinga
(Data obrony: 2006) Kawecka-Magiera, Barbara
Wydział Fizyki i Informatyki Stosowanej
W pracy na temat "Własności magnetyczne układów niejednorodnych w modelu Isinga" prezentowane są obliczenia numeryczne niektórych parametrów magnetycznych, takich jak namagnesowanie, podatność i korelacje spinowospinowe, dla układów niejednorodnych opisanych za pomocą modelu Isinga. Przedmiotem pracy było opracowanie narzędzi programistycznych, przeznaczonych do badania charakterystyk w niejednorodnych układach magnetycznych, w oparciu o algorytm symulacji Monte Carlo, przetestowane programów z pomocą dostępnych danych eksperymentalnych i analitycznych i zastosowanie do badania magnetycznych własności układów o różnym stopniu i charakterze niejednorodności. Główne zagadnienia rozważane w pracy można przedstawić następująco: Wyznaczanie przebiegów korelacji spinowo-spinowych w funkcji temperatury dla dwuwymiarowego modelu Isinga i dla szkła spinowego. Wyliczanie zasięgu korelacji spinowo-spinowych w zależności od temperatury w cienkich warstwach magnetycznych. Badanie anizotropii funkcji korelacji w szkłach spinowych i w cienkich warstwach magnetycznych. Analiza wpływu warunków brzegowych na powierzchni cienkiej warstwy na kształt profilu namagnesowania wewnątrz próbki. Obliczenia podatności magnetycznej i magnetyzacji w szkłach spinowych z nieporządkiem węzłów. Badanie wpływu stopnia porządkowania atomowego i rozmiaru ziaren krystalicznych w układach nanokrystalicznych na podatność magnetyczną. Wykazanie możliwości powstania anizotropii jednozwrotowej w stopie podstawieniowym, wygrzewanym w polu magnetycznym.
Access status: Open Access ,
Techniki symulacji agentowej w zastosowaniu do badania procesów cieplnych
(2001-04-26) (Data obrony: 2006-09-26) Bieniasz, Sławomir
Wydział Elektrotechniki, Automatyki, Informatyki i Elektroniki
The subject of this research is the problems of dynamic, complex systems modeling, in which several processes proceeds at the same time and in the common environment. The essence of the proposed modeling method lies in mapping elementary processes and their interactions, leading to achieving summary effects, that result from concurrent realization of these processes. The suggested idea is based on using the agent approach, where individual agents conduct elementary component actions, giving a result in complex processes occurring in virtual world, represented by this model. The purpose of this work is proving that such approach enables approximate but adequate mapping of the real phenomena, and in consequence predicting their course and introduction of correcting actions (control). The domain of the phenomena being analyzed is thermal processes with a special consideration of the phenomena which appear during cooling and solidification of metal castings. However, the given method is recommendation of modeling and studying a wider class of complex dynamic systems.
Access status: Open Access ,
Mikrostruktura i właściwości biomateriałów tytanowych po obróbce powierzchniowej
(2002-06-24) (Data obrony: 2006-12-05) Biel, Magdalena
Wydział Inżynierii Metali i Informatyki Przemysłowej
The aim of the study was to determine the influence of surface treatment methods on mechanical and tribological properties of metallic materials applied in medicine. The investigation was performed on titanium and Ti6A17Nb alloy after nitridation under glow discharge and after duplex surface treatment. The last method combines nickel electroless chemical deposition with a glow discharge assisted plasma treatment. Complex, quantitative and qualitative analysis of nano/microstructure of formed layers and bulk materials was carried out. Advanced methods of analytical transmission electron microscopy and atomic force microscopy were applied. Influence of surface treatments on layers topography, microhardness, Young modulus and wear friction resistance was determined. Adhesion of formed layers to bulk materials was estimated as well. The results obtained showed that hard multilayers formed during nitridation under glow discharge and duplex surface treatment significantly improve microhardness and wear resistance of the investigated materials.
Access status: Open Access ,
Rachunek macierzy nad kratami
(2006-04-06) (Data obrony: 2007) Pękala, Barbara
Wydział Matematyki Stosowanej
The aim of the thesis ”Calculus of matrices over lattices” is an examination of binary operations in the family of matrices over a lattice. If leads to the generalization of results known for the Boolean matrices and matrices over the lattice ([0, 1], max, min). The main way of generalizations concerns distributive lattices (L,∨,∧) and semirings (L,∨,∧,∗) obtained in a lattice with an additional binary operation ∗. Some new results for the lattice ([0, 1], max, min) refer to the order equivalence of matrices and their powers. At the beginning, the properties lattice operations in the family of matrices and order equivalence for matrices are examined. Known results about lattices of matrices are generalized and shown in the uniform terminology of lattice calculus and ordered semigroups. Some matrix properties are preserved by lattice operations. A dependence between an ordinal equivalence relation and lattice operations or matrix properties is established. Next, the analysis of dependence between properties of a binary operation ∗ and properties of the sup −∗ composition is contained. Finally, convergence and periodicity of matrix sequences and some properties of the family of interval matrices are considered.
Access status: Open Access ,
Falkowe techniki przetwarzania sygnałów dyskretnych w systemach czasu rzeczywistego
(2001-12-20) (Data obrony: 2007) Półchłopek, Wojciech Tomasz
Wydział Elektrotechniki, Automatyki, Informatyki i Elektroniki
The main issue of the thesis is the development of effective methods implementing reversible integer to integer wavelet transforms (ITI) and their fast real-time signal processing applications. The new concept of the effective implementation of the ITI transform called "Fast Integer Arithmetic Wavelet Transform (FIAWT)" is presented together with its application to FPGA (DWT and undecimated DDWT). The application of the DDWT and FIAWT lifting scheme permitted an efficient implementation of the multistage prewhitening matched filters (and Wiener filters). The R&D activities for the Imaging Cosmic And Rare Underground Signals (ICARUS) particle physical experiment were connected with the development of the universal data compression and signal recognition algorithms. The implementation, mentioned above, is the full real-time realization of the concepts included in the thesis. The hardware-software applications, because of the effective compression algorithm, permitted very high compression ratios (600 times) in the ICARUS DAQ system.
Access status: Open Access ,
Opracowanie modelu matryc mikroelektrodowych oraz układu scalonego do elektrycznej stymulacji żywych sieci neuronowych
(2004-01-19) (Data obrony: 2007) Hottowy, Paweł
Wydział Fizyki i Informatyki Stosowanej
The aim of the thesis was to develop a model of an array of planar microelectrodes and to design an integrated curcuit to be used in the future system for simultaneous and independent stimulation and recording neuronal activity of hundreds cells. The first two chapters include discussion of neuronal cell operation and its interaction with a microelectrode, which enables to record the cell activity and to stimulate it electrically. Next, the microelectrode theory and results of impedance parametrization of the array are given. In chapter 4 the parameters of generated signals required for efficient and safe stimulation of alive tissue are discussed. In the following, the stimulation protocol leading to significant reduction the stimulation artifacts is proposed. In the last chapter the design of 64-channel integrated circuit for stimulation of neural cells and the results of its electrical tests are presented.
Access status: Open Access ,
Metoda bezpiecznego wyburzania kominów z zastosowaniem techniki strzelniczej
(2004-06-24) (Data obrony: 2007) Krzyworączka, Paweł
Wydział Górnictwa i Geoinżynierii
The present doctoral shows the complete method of directional knocking down factory chimneys with usage of blasting technique. The methodology was worked out by: The analysis of forces and moments of forces which are changing in time of chimneys overthrowing. This analysis foresees the movement of the chimney taking into account among other things, deviation of the chimney, wind and air resistances. The researches of the chimney concrete durability using non-destructive method, with usage of Schmidt hammer. The durability of concrete shell is the essential factor, having influence on the direction of chimney fall. The analysis of the stress which rises on the surface of resistance during striking down the chimney; this permits to foresee the prospective area of concrete crushing. It doctoral there were created two computer programmes: Schmidt for chimneys 1.0 and Chimney 2.0, which help with calculations. The execution the above mentioned researches and analyses permits to establish, if the planned technology and the direction of the chimney overthrowing are safe for surroundings. There were also presented additional solutions, including the innovatory technology of enlarging the durability of the surface of resistance.
Access status: Open Access ,
Właściwości częstotliwościowe transmultipleksacji obrazów
(2004-06-24) (Data obrony: 2007) Ciosmak, Józef
Wydział Elektrotechniki, Automatyki, Informatyki i Elektroniki
The dissertation presents issues of acoustic signals and monochromatic images transmultiplexation. It covered aspects of modelling the structures of 1-D and 2-D transmultiplexers. Special emphasis was put on the description of over- and subsampling, the design of transmultiplexer filter system and spectral analysis of composite (image) signal. The method of the design of filter system as the function of the delay was described on the basis of1-D transmultiplexer model. The presented filters satisfy the conditions of perfect reconstruction, regardless of the delay arbitrarily selected out of permitted delay range. The provided examples of filters were obtained both numerically and analytically. Systems of filters with integer and rational coefficients, which completely eliminate reconstruction errors, are of special interest. The means of 1-D transmultiplexers applications to the transmission of images with various ordering concepts were presented. The operation of such a system with classic groups of text images was examined. Frequency effects were particularly accounted for. hnage transmultiplexer model made entirely of 2-D elements was built. The model analysis was supplemented by a detailed description of the systems for 2-D over- and subsampling in the frequency domain and z-domain. The consequences of over- and subsampling were shown taking into account image rotation. The change in the location of original pixels was linked to Kronecker product. On the basis of 2-D transmultiplexer model, a new method for the determination of the set of inseparable 2-D filters, which make it possible to accurately reconstruct images from a composite image, was presented. The examples of such filters obtained with numerical computation for transmultiplexers of rectangular grid were given. It was found out that the minimal pixel shift in reconstructed images, caused by 2-D filtration is unitary in the direction of lines or columns, irrespective of the order of the filters designed. The concept of 2-D separable filter design out of 1-D filter bank with the use of Kronecker product was put forward and verified. It was proved that on the basis of the conditions of perfect image reconstruction it is possible to determine sets of integer 2-D transmultiplexers, which totally eliminate reconstruction errors. Moreover, the composite image spectrum occupies a broader frequency band that the input images band. It contains specific, rotational multiplication of transmitted image spectra produced by specified oversampling and 2-D filtration.
Access status: Open Access ,
Określenie energii udaru młotów hydraulicznych na podstawie pomiarów wybranych parametrów pracy
(2001-06-27) (Data obrony: 2007) Szykowny, Krzysztof
Wydział Inżynierii Mechanicznej i Robotyki
The doctor thesis is dedicated to the problem of the determination of the impact of hydraulic hammers, using the indirect method, basing on the measurements of hydraulic parameters. The introductory part of the thesis describes the construction and the principles of functioning as well as the rules of hydraulic hammer operation. The methods of determining the impact energy value were discussed, also the influence of the wear of hammer elements on the values and the runs of their external parameters were determined. A method to determine the hydraulic hammer impact energy was suggested basing on the measurements of the pressure values on hydraulic supply and outflow lines. A testing methodology to verify the method adopted was presented. The testing of the operational parameters of hydraulic hammers under difficult pit exploitation conditions was carried out, the elements of the measurement path were selected and verified as well as the measurement methodology was proposed. The comparison of measurement results made on a specialist diagnostic test bench (the design of the test bench was made by the AGH University of Science and Technology in Kraków with the co-operation of KGHM Polska Miedź S.A. using a strain gauge energy converter) with those performed at the mining pit bottom proved the validity of the assumptions adopted. The paper demonstrates a capability to make an engineering assessment of the hydraulic hammer under the conditions of the hydraulic hammer operation, i.e. at the mine pit bottom. The simple inspection and diagnostic procedure allows to avoid the cost related to the disassembly/assembly, transportation, use of the diagnostic test bench.
Access status: Open Access ,
Self-configurable service with elements of adaptability for monitoring of infrastructure and applications in a grid environment
(2005-09-29) (Data obrony: 2007) Bałos, Kazimierz
Wydział Elektrotechniki, Automatyki, Informatyki i Elektroniki
The dissertation proposes a concept a JIMS monitoring service, which is selfconfigurable, scalable, and equipped with elements of adaptability. The thesis is organised as follows. Chapter 1 contains the motivation for the dissertation, introduces key terms and contains the thesis statement. Chapter 2 is a critical survey of existing standards, technologies, and projects related to grid monitoring. Chapter 3 characterizes the grid as a whole, provides functional and non-functional requirements for the grid monitoring service and contains the thesis statement. The concept of the JIMS system, built according to the given requirements and assumptions, is described in Chapter 4. This chapter describes key solutions applied in the system, such as the component model and a uniform approach to resources representation, cluster- and grid-level self-configurability as well as elements of adaptability. The design and implementation details of this prototype are presented in Chapter 5. This chapter also introduces the concept of sensors for chosen elements of the grid infrastructure and middleware. Chapter 6 covers system evaluation and verification of results, where the author presents results of JIMS system usage in real grid installations and test results dealing with system intrusiveness, performance, and functionality. Chapter 7 presents results and summarizes the dissertation. The dissertation concludes with a list of common abbreviations, acronyms, definitions and indexed words, which should assist readers of this document.
Access status: Open Access ,
Ocena wpływu pozatorakalnych dróg oddechowych na oddechową impedancję wejścia
(2004-11-25) (Data obrony: 2007) Latawiec, Wojciech
Wydział Elektrotechniki, Automatyki, Informatyki i Elektroniki
During the assessment of resistive properties of the respiratory system it is adviced that the patent supports his/her cheeks with palms,. This is made to minimize the influence of extrathoracic airways on the measurements of input respiratory impedance (Zin). Upper airway impedance (Zuaw) can seriously influence the measurements of input impedance (and respiratory system impedance), and supporting the cheeks increases Zuaw, thus minimizing its influence on Zin measurements. Knowing Zuaw -makes possible the correction of Zin. To prove that thesis following actions were undertaken: Measurements of input impedance in different setting were made. A special mask has been designed to allow measurements with the helmet and cheeks supported, which allowed the calculation of Zuaw and its comparison to the impedance obtained during Valsalva maneuver with cheeks supported. Mean values of impedances Zuaw, ZuawSTP, Zval, ZvaISTP were used to ąuantify the influence of Zuaw on Zin. Models of Zuaw have been proposed, which yielded to assessment of extrathoracic airways properties and evaluation of the influence of supporting the cheeks on Zuaw models' parameters. A correction of Zin with the calculated values of Zuaw has been performed.
Access status: Open Access ,
Rekonstrukcja historii metamorfizmu skał grupy Isbjørnhamna z SW części Ziemi Wedel Jarlsberga na Spitsbergenie
(2004-11-08) (Data obrony: 2007) Majka, Jarosław
Wydział Geologii, Geofizyki i Ochrony Środowiska
The goal of this research was to quantify the age and P-T metamorphic conditions of the polymetamorphic Isbjørnhamna Group rocks from the SW part of Wedel Jarlsberg Land on Spitsbergen. Dated monazites (U-Th-total Pb method) and zircons (U-Pb method) yielded Neoproterozoic (ca. 640Ma) age of older metamorphic event. Compilation of the results of geothermobrometry (with use of garnet-biotite geothermometer and GASP geobarometer) and the KFMASH petrogenetic grid allow to estimate that, over mentioned metamorphic event took place under upper amphibolite facies conditions. The peak conditions were described as T= ca. 660ºCi P= ca.11kbar. Additionally it was assumed that younger metamorphic event took place under temperature lower then 350ºC (on the basis of chlorite geothermometer and thermochronology) and under calm tectonic conditions.
Access status: Open Access ,
Wymiana ciepła w procesach kucia swobodnego odkuwek
(2004-04-20) (Data obrony: 2007) Hadała, Beata
Wydział Inżynierii Metali i Informatyki Przemysłowej
Open die forging belongs to processes of the plastic working, in which heat transfer, characterized by the heat transfer coefficient between material being deformed and the anvil and the air, is a function of many variables. At doctor's thesis an attempt was made to determine the size of the heat transfer coefficient depending on size of the contact surface area between the forging and the anvil, degree of deformation, presence of primary scale, increase of the secondary scale during the forging operation, thermal resistance of anvil surface and temperature of material. The heat generation as a result of the work of the plastic strain was also taken into consideration. Thanks to applying numerical modeling, verified experimentally through thermovision measurements determining the forging surface temperature and temperature distribution in the cross section, value of heat transfer coefficient was determined. It ranges from 310 to 450 W / (m2 •K). A considerable influence was stated to its size depending on the thickness of the scale on the surface and the anvil. Also a slight influence of the contact surface between the forging and the anvil to the surface temperature of the forging was determined and no impact on the temperature field in the cross section of material. An also slight increase of the material temperature was observed in the consequence of plastic strain.
Access status: Open Access ,
Wpływ rozkładu właściwości fizycznych i geometrycznych ziaren na dokładność rozdziału w osadzarce na przykładzie węgla
(2004-06-24) (Data obrony: 2007) Surowiak, Agnieszka
Wydział Górnictwa i Geoinżynierii
To realize the main work purpose, which was the assessment of the influence of the particles physical and geometrical properties distribution on separation efficiency, the heuristic approach was applied. Basing on the probability theory relating to the random variables functions, the algorithm of calculation the distribution of irregular particles sedimentation velocity in sample was elaborated, which is the function of both physical and geometrical properties of the particle. By assuming that the vertical part of particle velocity in working cell of the jig can be described by Maxwell distribution function, the equation of separation curve was presented in the form of normal distribution function. Currently, it is only the physical warrant of applying the normal distribution function as the separation function. The given formulas were verified empirically on the basis of the sampling results of industrial jigging and measurements of the particle shape coefficients, as well of the projective diameter. From the separation curve equation, the functional form of probable dissipation dependence on the particle geometrical and physical properties, conditions of process conducting and specific capacity was derived. The evaluation of the influence of the particle physical and geometrical properties on separation efficiency was performed on the basis of the imperfection value and its correlation with particle sedimentation velocity.
Access status: Open Access ,
Wpływ dodatków $TiB_2$, $SiC$ oraz $WO_2$ na właściwości mechaniczne i elektryczne kompozytów typu srebro-ceramika
(2004-01-06) (Data obrony: 2007) Ciuman-Krzemień, Agata
Wydział Metali Nieżelaznych
Simply method of processing a secondary raw material containing silver into final product like silver-ceramics composite electrical contacts was elaborated. The recycling of silver from difficultly soluble AgCl by its direct reduction was investigated in the cell $Zn|H_{2}SO_{4},AgCl|Ag$. Silver chloride did not directly contact with the reducing metal. It was found that the reduction of Ag+ ions process probably runs under activation control. The silver powder obtained by this method shows high purity and fine grain with average chord about 1 [µm] and perfectly fulfills as the matrix of composite. The silver was strengthened by obtaining material containing 2–40 wt% of ceramics like $TiB_2$, $SiC$ or $WO_2$. Composite contact materials were obtained by powder metallurgy method (pressing-sintering). Samples were pressed (p = 100 – 700 [MPa]) and then sintered at temperature 850ºC for 45 minutes in an argon atmosphere. It was found that the increase of the compacting pressure causes the increase of density of compacts. The compressibility of the pressed samples deteriorates with the increase of content of ceramic additions. It was also found that the ceramic addition in the silver powder prevents from the growth of compacts during sintering process. It was found that there is a correlation between the relative density of sintered silverceramics composite and their hardness and also their electrical conductivity. Studied composites are characterized by high conductivity and low contact resistance. Uniform distribution of ceramic particles in the metallic matrix is obtained.
Access status: Open Access ,
Niezmiennicze podprzestrzenie typu Lorentza liniowych operatorów w przestrzeniach Banacha
(2005-03-10) (Data obrony: 2007) Tłuczek-Pięciak, Renata
Wydział Matematyki Stosowanej
Celem pracy było zbadanie własności nowej klasy niezmienniczych podprzestrzeni typu Lorentza, zbudowanych w dziedzinie dowolnego domkniętego liniowego nieograniczonego operatora gęsto określonego w zespolonej przestrzeni Banacha. W pracy opisany został związek między wprowadzoną klasą a znanymi wcześniej niezminniczymi podprzestrzeniami w postaci równości interpolacyjnej. Poprzez równość interpolacyjną została też opisana własność niezmienniczości wprowadzonej klasy względem funktora rzeczywistej interpolacji. Udowodniono, że wprowadzone podprzestrzenie są niezmiennicze względem operatora, zawężenie operatora do tych podprzestrzeni jest operatorem ograniczonym, oszacowano normę tego zawężenia, zbadano własności spektralne tego zawężenia, udowodniono, że przy dodatkowym założeniu tzw. warunek Levinsona dla rezolwenty operatora jest warunkiem wystarczającym dla gęstości badanych niezmienniczych podprzestrzeni. Zdefiniowano i oszacowano funkcjonał najlepszej aproksymacji "mierzący" najkrótszą odległość do niezmienniczej podprzestrzeni. Zbadano też niezmiennicze podprzestrzenie typu Lorentza iteracji operatora. W ostatnim rozdziale pracy przytoczono przykłady zastosowań teorii.
Access status: Open Access ,
Rola gazu ziemnego w bilansie paliwowo-energetycznym kraju ze szczególnym uwzględnieniem energetyki w aspekcie wymogów ochrony środowiska
(2004-06-24) (Data obrony: 2007) Szurlej, Adam
Wydział Paliw i Energii
The main aim of the research was to present the importance and the role of natural gas for the power industry. The aim was achieved on the basis of the economic and ecological analysis. The paper presents multi-dimensional issues concerning the generation of electricity. The discussion covers: the presentation of natural gas as an energy source, the role of natural gas in the national structure of the primary energy resources, the influence of the electricity and thermal generation on the natural environment, the various methods of evaluation of the costs related to the generation of electricity from hard coal, brown coal and natural gas, the optimization of energy resources for the generation of electricity, the analysis of the level of possibility that the energy industry based on natural gas will develop successfully in the future. The study focuses also on the external costs of the electricity generation and their influence on total costs of electricity generation. The analysis of the costs of the electricity generation from natural high- methane gas and nitrogen-rich gas was delved for gas engines, gas turbines and gas-steam blocks.
Access status: Open Access ,
The multiple-input multiple-output systems in slow and fast varying radio channels
(2006-09-28) (Data obrony: 2007) Kułakowski, Paweł
Wydział Elektrotechniki, Automatyki, Informatyki i Elektroniki
In this thesis, the performance of the MIMO (Multiple-Input Multiple-Output) systems in slow and fast varying radio channels is discussed. In the chapter 1, the general issues of MIMO systems are considered. The tradeoff between the spatial multiplexing and the diversity is explained. The importance of the channel knowledge is discussed. Also, the telecommunication standards concerning the MIMO systems are described. The chapter 2 is devoted to the channel aspects of MIMO systems. Then, the most important MIMO channel models are presented. The issues of the channel estimation and the time variations are included. In the last two chapters, the research results of the author of this thesis are presented. The broad analysis of the wireless MIMO indoor network in slow varying radio channel is performed in the chapter 3. The directivity of the access point antennas and their location are carefully studied. The MIMO system with adaptive antennas is also considered. Ali the calculations are made on the basis of the deterministic ray tracing model. In the chapter 4, the new algorithm for channel estimation in fast varying radio channels is introduced and verified. It is shown that bit error rate can be decreased without frequent transmissions of pilot symbols. The thesis closed with the general conclusions about the author's research and the MIMO systems in time-varying channels.