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Search results for: SEMI-MARKOV PROCESSES
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Application of semi-Markov processes for evaluation of diesel engines reliability with regards to diagnostics
PublicationThe paper presents semi-Markov models of technical state transitions for diesel engines, useful for determination of their reliability, as a result of the conducted statistical empirical studies. Interpretation of technical states provided for this sort of engines refers to ship main engines, i.e. engines employed in propulsion systems of sea-going ships. The considerations recognize diesel engine as a diagnosed system (SDN), of...
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COMPARATIVE ANALYSIS OF RESULTS OF APPLICATION OF MARKOV AND SEMI-MARKOV PROCESSES TO RELIABILITY MODELS OF MULTI-STATE TECHNICAL OBJECTS
PublicationDuring rational operation of technical objects and systems various operational decisions are made and decision-making process itself should be consisted in selecting that considered most favourable out of all possible to be taken. Choice of such decision is possible after taking into account many different information items but it never be completely correct without accounting for data and indices dealing with reliability. In...
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Necessity for and possibility of application of the theory of semi-markov processes to determine reliability of diagnising systems
PublicationW opracowaniu uzasadniono konieczność określenia niezawodności systemów diagnozujących (SDG) do sformułowania diagnozy o stanie dowolnego urządzenia technicznego jako systemu diagnozowanego (SDN). Wykazano, że znajomość niezawodności SDG umożliwia określenie wiarygodności diagnozy. Przyjęto, że wiarygodność diagnozy może być określona jako właściwość diagnozy określająca stopień rozpoznania przez system diagnozujący (SDG) rzeczywistego...
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USEFULNESS OF SEMI-MARKOV PROCESSES AS MODELS OF THE OPERATION PROCESSES FOR MARINE MAIN ENGINES AND OTHER MACHINES OF SHIP POWER PLANTS
PublicationThe paper describes the properties of semi-Markov processes and the opportunities and benefits from their use as models of the operation processes for marine combustion engines and other machines of ship power plants. The emphasis is put on the importance of the theory of semi-Markov processes for development of the theory of marine combustion engines and other machines of ship power plants, as well as for development of the operational...
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Application of theory of semi-Markov processes to determining distribution of probabilistic process of marine accidents resulting from colission of ships
PublicationIn this paper is presented possible application of the theory of semi-Markov processes to elaborating an eight-state model of the process of occurrence of serviceability state and unserviceability states of sea-going ships making critical manoeuvres during their entering and leaving the ports. In the analysis it was taken into account that sea-going ships are in service for a very long time t (t → ∞). The model was elaborated to...
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Application of the theory of semi-markov processes to the development of a reliability model of an automotiv vrhicle = Zastosowanie teorii procesów semi-Markowa do opracowania modelu niezawodnościowego samochodu
PublicationW artykule przedstawiono możliwość zastosowania teorii procesów semi-Markowa (semimarkowskich) do opisu niezawodności samochodu, na przykładzie samochodu osobowego. W rozważaniach uwzględniony został samochód, w którym wyróżniono takie węzły konstrukcyjne (zespoły funkcjonalne) jak: silnik z układami zasilania czynnikami energetycznymi (paliwem, olejem smarowym i cieczą chłodzącą), sprzęgło, skrzynia biegów, wał napędowy, most...
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Assesment of operation of ship main diesel engine using the theory of semi-markovian and markov processes.
PublicationTo precisely determine the task it is necessary to specify also its duration time, apart from conditions in which it will be realized. When considering propulsion engine, i.e. the main element of ship propulsion system, especially important becomes not only the problem which amount of energy could be at one's disposal but also within which time interval it could be delivered. Therefore apart from applying the commonly used reliability...
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APPLICATION OF THE THEORY OF SEMI-MARKOV PROCESSES TO DETERMINE A LIMITING DISTRIBUTION OF THE PROCESS OF CHANGES OF ABILITY AND INABILITY STATES OF FUEL SUPPLY SYSTEMS IN HEAVY FUEL DIESEL ENGINES
PublicationThe paper presents applicability of the theory of semi-Markov processes to determine a limiting distribution of the process of changes of technical states of fuel systems for marine engines running on heavy fuel oils. The proposed study of this process includes the components of such fuel systems like: 1 - injectors, 2 - high pressure hoses, 3 - injection pumps, 4 - low pressure hoses, 5 – fine filters, 6 - coarse filters, 7 – fuel-feed...
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A model of fuel combustion process in the marine reciprocating engine work space taking into account load and wear of crankshaft-piston assembly and the theory of semi-Markov processes
PublicationThe ar ticle analyses the operation of reciprocal internal combu stion engines, with mar ine engines u sed a s an example. The analysis takes into account types of energy conversion in the work spaces (cylinders) of these engines, loads of their crankshaft-piston assemblies, and types of fuel combustion which can take place in these spaces during engine operation. It is highlighted that the analysed time-dependent loads of marine...
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Semi-Markov Approach to the Shipping Safety Modelling
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Application Isssues of the Semi-Markov Reliability Model
PublicationPredicting the reliability of marine internal combustion engines, for instance, is of particular importance, as it makes it possible to predict their future reliability states based on the information on the past states. Correct reliability prediction is a complex process which consists in processing empirical results obtained from operating practice, complemented by analytical considerations. The process of technical state changes...
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Markov Processes and Related Fields
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The Matter of Decision-Making Control Over Operation Processes of Marine Power Plant Systems with the Use of their Models in the form of Semi-Markov Decision-Making Processes
PublicationThe article presents the possibility to control the real operation process of an arbitrary device installed in the marine power plant based on the four-state semi-Markov process, being the model of the process, which describes the transition process of operational states of the device and the transition process of its technical states. All these states are precisely defined for the ship main engine (SG). A hypothesis is proposed...
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Semi-Markov model of diesel engines' operating process.
PublicationNajistotniejszym problemem eksploatacji silników o zapłonie samoczynnym jest problem racjonalnego (a zwłaszcza optymalnego) sterowania procesem eksploatacji tych silników. Sterowanie takie może ułatwić zastosowanie iteracyjnego algorytmu wyznaczania optymalnych strategii opracowanego przez R.A. Howarda. Wykorzystanie jednak tego algorytmu do sterowania procesem eksploatacji silników wymaga między innymi opracowania modelu procesu...
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A semi-Markov model of fuel combustion process in a Diesel engine
PublicationW artykule przedstawiono czterostanowy model procesu spalania w przestrzeniach roboczych (cylindrach) silników o zapłonie samoczynnym w formie procesu semimarkowskiego, dyskretnego w stanach i ciągłego w czasie. Wartościami tego procesu są stany odpowiadające powszechnie akceptowanym rodzajom spalania w tego rodzaju silnikach a mianowicie takie stany procesu jak: spalanie pełne (całkowite i zupełne), spalanie niezupełne, spalanie...
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Optimal asynchronous estimation of 2D Gaussian-Markov processes
PublicationW artykule rozważa się problem estymacji trajektorii dwuwymiarowych ciągłoczasowych procesów Gaussa-Markowa na podstawie zaszumionych pomiarów wykonywanych w nierównomiernie rozłożonych chwilach czasu. W przypadku takiego problemu, w każdym cyklu pracy algorytmu należy dokonać dyskretnoczasowej predykcji (analogicznie jak w przypadku filtru Kalmana). Niestety zadanie to może być złożone obliczeniowo. Aby rozwiązać ten problem,...
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The time of the first transition of the semi-Markov process in the evaluation of diesel engine operation
PublicationW referacie przedstawiono rozwinięcie prezentowanej w literaturze metody ilościowej oceny działania na przykładzie okrętowego silnika głównego z zapłonem samoczynnym. Według tej interpretacji, działanie silnika może zostać przedstawione jako wielkość fizyczna. W tym aspekcie, na przykładzie okrętowego silnika napędu głównego dokonano oceny przydatności tej wielkości do opisu własności niezawodnościowych silnika. Precyzyjne określenie...
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Physical aspect of application and usefulness of semi-Markovian processes for modelling the processes occurring in operational phase of technical objects.
PublicationW artykule zasygnalizowano przydatność teorii procesów semimarkowskich do tworzenia modeli procesów rzeczywistych, zachodzących w fazie eksploatacji różnych obiektów technicznych. Przydatność tej teorii została wykazana w wyniku przedstawienia: specyfiki procesów semimarkowskich oraz fizykalnych aspektów stosowania procesów semimarkowskich jako modeli procesów zachodzących w fazie eksploatacji wspomnianych obiektów. Specyfika została...
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Możliwość oszacowania niezawodności silników o zapłonie samoczynnym z zastosowaniem teorii procesów semi-Markowa oraz podejmowania decyzji eksploatacyjnych z uwzględnieniem wiarygodności diagnozy o stanie technicznym tego rodzaju silników spalinowych = Possibility of estimating the reliability of diesel engines by applying the theory of semi-Markov processes and making operational decisions by considering reliability of diagnosis on technical state of this sort of combustion engines/
PublicationThe paper presents semi-Markov models of technical state transitions for diesel engines, useful for determining reliability of the engines. A possibility of application of a three-state model with a simplified matrix function, or even a two-state model, to determine reliability of the engines, has been described herein on examples of known from literature semi-Markov models, for the case when appropriate diagnosing systems (SDG)...
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Semi-Markow Processes as Models of Devices´ Operating Process of Ship Pro-pulsion System
PublicationReferat zawiera formalny opis procesu eksploatacji urządzeń.
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The semi-Markov model of the process of appearance of sea-going ship propupsion system ability and inability states in application to determining the reliablity of these systems
PublicationThe article presents possible application of the theory of semi-Markov processes in creating the eight-state model of the process of appearance of the propulsion systems ability and inability states on sea-going vessels performing transportation tasks in a relatively long operating time t (t → ∞). The model has been proved to be able to be successfully used for determining the reliability of the abovementioned systems. The probability...
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The semi-Markov model of energy state changes of the main marine internal combustion engine and method for evaluating its operation during ships voyage
PublicationPrzedstawiono metodę oceny działania tłokowych silników spalinowych napędu głównego statków morskich, nazywanych silnikami głównymi, działających w różnych warunkach ich eksploatacji. Metoda ta umożliwia obliczenie wartości działania w wyniku zastosowania teorii procesów semimarkowskich i statystyki matematycznej. Znamienne jest to, że działanie wspomnianych silników spalinowych zostało przyrównane do wielkości fizycznej, którą...
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Limiting distribution of the three-state semi-Markov model of technical state transitions of ship power plant machines and its applicability in operational decision-making.
PublicationThe article presents the three-state semi-Markov model of the process {W(t): t 0} of state transitions of a ship power plant machine, with the following interpretation of these states: s1 – state of full serviceability, s2 – state of partial serviceability, and s3 – state of unserviceability. These states are precisely defined for the ship main engine (ME). A hypothesis is proposed which explains the possibility of application...
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TEORIA DECYZYJNYCH PROCESÓW SEMI-MARKOWA I JEJ ZASTOSOWANIE W PROJEKTOWANIU I EKSPLOATACJI OKRĘTOWYCH SILNIKÓW GŁÓWNYCH I INNYCH URZĄDZEŃ SIŁOWNI OKRĘTOWYCH
PublicationW referacie zaprezentowano znaczenie teorii procesów semi-Markowa w naukach technicznych, zwłaszcza w teorii niezawodności urządzeń technicznych, teorii bezpieczeństwa ich działania oraz statystycznej teorii podejmowania decyzji eksploatacyjnych. W referacie wyeksponowano także przydatność teorii procesów semi-Markowa w teorii i praktyce eksploatacji wspomnianych urządzeń technicznych na przykładzie tak istotnych urządzeń w transporcie...
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Usage of Memi-Markov Process in Operation Evaluation of Diesel Engine
PublicationIn paper, the proposition of quantitative evaluation of operation using semi-Markov processes theories has been presented. Basic assumptions, essential for creating mathematical model on example of diesel engine were shown. Special attention was given to practical aspects of using established mathematical model. Example of characteristic of analysed process - temporary distribution of probability was assigned.
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Determination of probabilities defining safety of a sea-going ship during performance of a transportation task in stormy weather conditions
PublicationThe paper presents the possibility of applying the theory of semi-Markov processes to determine the limiting distribution for the process of changes of technical states being reliability states of the systems of sea-going ships significantly affecting safety of such ships, which include main engine, propeller and steering gear. The distribution concerns the probabilities of occurrence of the said states defined for a long time...
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Four-state stochastic model of changes in the reliability states of a motor vehicle
PublicationThe properties of semi-Markov processes have been generally characterized and the applicability of the theory of such processes to the determining of the reliability of motor cars and other road vehicles has been explained. A formal description of the process of changes in the motor vehicle technical states considered as reliability states and a model of this process in the form of a one-dimensional stochastic process have been...
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PROBLEMY RACJONALNEGO ZASTOSOWANIA SYSTEMÓW DIAGNOZUJĄCYCH DO PODEJMOWANIA DECYZJI W FAZIE EKSPLOATACJI URZĄDZEŃ ENERGETYCZNYCH Z UWZGLĘDNIENIEM ZAGADNIEŃ KWANTOWYCH
PublicationW rozdziale przedstawiono najistotniejsze problemy pojawiające się w fazie projektowania, wytwarzania i eksploatacji systemów diagnozujących (SDG) urządzeń energetycznych (będących systemami diagnozowanymi – SDN), w przypadku przysposabiania ich do opracowania finalnej diagnozy eksploatacyjnej. Przestawiono opisową i formalną interpretację pojęcia systemu diagnozującego (SDG). Zaproponowano modele procesu diagnozowania urządzeń...
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Features of load and wear of main propulsion devices on sea-going ships with piston combustion engines and their impact on changes in technical states of the systems
PublicationThe paper presents the specificity of operation of propulsion systems of seagoing ships which causes the need to control the load on them, especially on their engines called main engines. The characteristics of the load on the propulsion systems, especially on the main engines as well as on the shaft lines and propellers driven by the engines, along with the process of wear in tribological joints (sliding tribological systems)...
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ISSUE OF MAKING DECISIONS WITH REGARD TO SHIP TRAFFIC SAFETY IN DIFFERENT SITUATIONS AT SEA
PublicationThe paper refers to the possibilities of making operational decisions that would enable to ensure safety to a ship in the event of application of the statistical decision theory with consideration of an expected value of consequences as a criterion for making such a decision. General description includes conditions for carrying out transportation tasks by ships and it has been shown that following this description it is possible...
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Microscopic examination of the texture of paper products
Open Research DataAtomic force microscopy (AFM) can be used to study the state of the paper fibers with the aim of providing qualitative and semi-quantitative information on degradation and aging. The work [1] reports the results of tests of various paper products subjected to deliberate aging processes under the influence of various factors. Chemical and biological...
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Processes
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Karol Flisikowski dr inż.
PeopleKarol Flisikowski works as Associate Professor at the Department of Statistics and Econometrics, Faculty of Management and Economics, Gdansk University of Technology. He is responsible for teaching descriptive and mathematical statistics (in Polish and English), as well as scientific research in the field of social statistics. He has been a participant in many national and international conferences, where he has presented the results...
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Types of Markov Fields and Tilings
PublicationThe method of types is one of the most popular techniques in information theory and combinatorics. However, thus far the method has been mostly applied to one-dimensional Markov processes, and it has not been thoroughly studied for general Markov fields. Markov fields over a finite alphabet of size m ≥ 2 can be viewed as models for multi-dimensional systems with local interactions. The locality of these interactions is represented...
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Four-node semi-EAS element in six-field nonlineartheory of shells
PublicationW pracy sformułowano 4-węzłowy powłokowy element skończony dla konstrukcji powłokowych. Element opracowano w ramach nieliniowej 6-parametrowej teorii powłok z niesymetrycznymi miarami odkształceń membranowych. Kinematyka powłoki jest opisana przez dwa pola: translacji i obrotów, przy czym wszystkie trzy parametry obrotu traktowane są jako niezależne. W wyniku tego sformułowany element nadaje się do analizy struktur powłokowych...
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Markov Model of Disease Development and Recovery
PublicationMarkov models are commonly used to simulate diseases and allow modeling of multiple health states and outcomes. Starting with the well known Le Bras multistate model (cascading failure model) with time-independent transitions we will see how simple Markov mortality models may be pressed into the service of survival and event history analysis. We will focus on more complex models which will be able to take into account remission,...
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Average Redundancy of the Shannon Code for Markov Sources
PublicationIt is known that for memoryless sources, the average and maximal redundancy of fixed–to–variable length codes, such as the Shannon and Huffman codes, exhibit two modes of behavior for long blocks. It either converges to a limit or it has an oscillatory pattern, depending on the irrationality or rationality, respectively, of certain parameters that depend on the source. In this paper, we extend these findings, concerning the Shannon...
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Laplace domain BEM for anisotropic transient elastodynamics
PublicationIn this paper, we describe Laplace domain boundary element method (BEM) for transient dynamic problems of three-dimensional finite homogeneous anisotropic linearly elastic solids. The employed boundary integral equations for displacements are regularized using the static traction fundamental solution. Modified integral expressions for the dynamic parts of anisotropic fundamental solutions and their first derivatives are obtained....
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Międzysektorowa mobilność zatrudnienia oraz płac a efektywność rynku pracy.
PublicationCelem artykułu jest uzyskanie odpowiedzi na pytanie, czy ocenę efektywności funkcjonowania rynków pracy, rozumianej jako zdolność rynków do „oczyszczania się”, można przedstawić za pomocą analizy międzysektorowej mobilności płac oraz zatrudnienia. W połowie lat 90. XX wieku Paul Krugman dowodził, iż negatywne szoki gospodarcze skutkują w krajach europejskich wzrostem bezrobocia, natomiast w USA wzrostem rozpiętości płac. Tymczasem...
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The use of Markov chains in the social convergence analysis
PublicationThe main goal of this article is to analyze the social convergence process using Markov chains. In this research, term social convergence refers to the reduction of dispersion in the standard of living among countries. The use of Markov chains in the social convergence analysis allowed describing movements of observational units within the distribution and providing more details about the mechanism of the convergence process. A...
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A note on a Wiener-Wintner theorem for mean ergodic Markov amenable semigroups
PublicationWe prove a Wiener-Wintner ergodic type theorem for a Markov representation of a right amenable semitopological semigroup.
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Survival time prognosis under a Markov model of cancer development
PublicationIn this study we look at a breast cancer data set of women from Pomerania region collected in year 1987-1992 in the Medical University of Gdańsk. We analyze the clinical risk factors in conjunction with Markov model of cancer development. We evaluate Artificial Neural Network (ANN) survival time prediction via a simulation study.
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Random Processes 2022/2023
e-Learning CoursesThe e-learning course page for the purpose of the remote or hybrid learning for Random Processes.
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Random Processes 2023/2024
e-Learning CoursesThe e-learning course page for the purpose of the remote or hybrid learning for Random Processes.
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Hybrid of Neural Networks and Hidden Markov Models as a modern approach to speech recognition systems
PublicationThe aim of this paper is to present a hybrid algorithm that combines the advantages ofartificial neural networks and hidden Markov models in speech recognition for control purpos-es. The scope of the paper includes review of currently used solutions, description and analysis of implementation of selected artificial neural network (NN) structures and hidden Markov mod-els (HMM). The main part of the paper consists of a description...
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Semi-definite programming and quantum information
PublicationThis paper presents a comprehensive exploration of semi-definite programming (SDP) techniques within the context of quantum information. It examines the mathematical foundations of convex optimization, duality, and SDP formulations, providing a solid theoretical framework for addressing optimization challenges in quantum systems. By leveraging these tools, researchers and practitioners can characterize classical and quantum correlations,...
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Automatics and control of technical processes 2023
e-Learning CoursesAutomatics and control of technical processes for Green Technologies 2023
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Relationship between semi- and fully-device-independent protocols
PublicationWe study the relation between semi and fully device independent protocols. As a tool, we use the correspondence between Bell inequalities and dimension witnesses. We present a method for converting the former into the latter and vice versa. This relation provides us with interesting results for both scenarios. First, we find new random number generation protocols with higher bit rates for both the semi and fully device independent...
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On quasi-compact Markov nets
PublicationAnalizuje się strukturę ergodyczną netów Markowa. W szczególności podano charakteryzację ściśle ergodycznych minimalnych (L-R) netów markowskich na zwartej przestrzeni fazowej. Uzyskano warunki równoważne quasi-zwartości (L-R) netów Markowa, rozszerzając tzw. ergodyczne twierdzenie Lotz'a.
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New polish catalogue of typical flexible and semi-rigid pavements
PublicationThe paper covers the following topics important for the development of the new Polish Catalogue of typical flexible and semi-rigid pavements: reasons for preparing the new issue of the Catalogue of typical flexible and semi-rigid pavements, items introduced in the new issue, organise the terminology related to pavements, design traffic calculations and new equivalent axle load factors,...