Autor: Knopik, L. - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: A note on failure rate of the mixture of an exponential distribution and distribution with increasing quadratic failure rate function
Autorzy:: Knopik, L.
Powiązania:: https://bibliotekanauki.pl/articles/206455.pdf
Data publikacji:: 2017
Wydawca:: Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:: mixture of distributions
quadratic failure rate function
failure rate function
Opis:: We show that a unimodal failure rate function can be obtained as a mixture of two increasing failure rate functions. Speciﬁcally, we study the failure rate of the mixture of an exponential distribution and an IFR (increasing failure rate) distribution with increasing quadratic failure rate function. At the end of the paper we show a numerical example of the modiﬁed unimodal failure rate function.
Źródło:: Control and Cybernetics; 2017, 46, 3; 291-297
0324-8569
Pojawia się w:: Control and Cybernetics
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Characterization of a class of lifetime distributions
Autorzy:: Knopik, L.
Powiązania:: https://bibliotekanauki.pl/articles/969965.pdf
Data publikacji:: 2006
Wydawca:: Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:: ageing classes
IFR
IFRA
NBUE
MTER
HNBUE
convolution
limit distribution
mixture
Opis:: In Knopik (2005) the ageing class MTFR (Mean Time to Failure or Repair) of lifetime distribution was introduced. In this paper, we show that the family MTFR is closed under weak convergence of distribution and convolution. We prove that the dual family MTFR^D (in a particular case) is closed under mixtures.
Źródło:: Control and Cybernetics; 2006, 35, 2; 407-414
0324-8569
Pojawia się w:: Control and Cybernetics
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Some results on the ageing class
Autorzy:: Knopik, L.
Powiązania:: https://bibliotekanauki.pl/articles/970997.pdf
Data publikacji:: 2005
Wydawca:: Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:: niezawodność
system równoległy i szeregowy
reliability
ageing class
DMRL
IFR
IFRA
NBUE
parallel and series systems
Opis:: In this paper, we investigate an ageing class of life distributions. We show that the family of life distributions is closed under formation of parallel and series systems. This class is situated between IFR and NBUE.
Źródło:: Control and Cybernetics; 2005, 34, 4; 1175-1180
0324-8569
Pojawia się w:: Control and Cybernetics
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Application of principal component analysis for optimization of a system operation assessment criteria set
Autorzy:: Muślewski, Ł.
Knopik, L.
Powiązania:: https://bibliotekanauki.pl/articles/247903.pdf
Data publikacji:: 2013
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: quality
criteria
transport system
analysis
canonical correlations
optimization
Opis:: The analysis of results of experimental tests and a literature survey of the issue reveal that the subject matter connected with determination of the optimal number of a given transportation system operation assessment criteria has a direct influence on the result of the considered assessment. The analysis was made within the research on operation quality of a selected transportation system. In order to optimize the analysed system assessment criteria, a theoretical description has been made and an example of canonical correlations application has been presented. Analysis of canonical correlations involves determination of linear combination parameters of the studied sets so that the obtained correlation coefficient will have maximal value. In the successive step, the next pair of linear combination are not correlated with the combinations determined in the first step. The determined correlations can measure the power of relation between two sets of variables and are useful in the process of choosing significant criteria for a given research object operation quality assessment.
Źródło:: Journal of KONES; 2013, 20, 4; 307-312
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Application of principal component analysis for optimization of a system operation assessment criteria set
Autorzy:: Muślewski, Ł.
Knopik, L.
Powiązania:: https://bibliotekanauki.pl/articles/242963.pdf
Data publikacji:: 2012
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: quality
criteria
transport system
analysis of main components
optimization
Opis:: The analysis of results of experimental tests and a literature survey on the issue reveal that the subject matter connected with determination of the optimal number of a given transportation system operation assessment criteria has a direct influence on the result of the considered assessment. Whole study has been made on the basis of the analysis of data obtained from tests performed in a real municipal transportation system, providing transport tasks in a 400 thousand urban agglomeration. On the basis of the tests, there was determined a set of sixteen criteria for the system operation assessment, depending on preferences of drivers, passengers, workers of the system providing vehicles with serviceability and the last group of results is a final assessment. The research involved tests of significance for correlation coefficients between the assessment criteria. The method of main factors involving analysis of a linear transformation of existing vector of variables X into Y has been used to study the task dimensioning. Proper values, providing basis for determination of a new space correspond to coordinates of the newly created vector Y. On this basis, the dimension of the criteria and their significance space has been concluded. The determined criteria have been accepted for the development of a resultant model for assessment of a transportation system operation quality.
Źródło:: Journal of KONES; 2012, 19, 4; 481-486
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Analysis of external factors affecting transport process safety
Autorzy:: Bojar, P.
Knopik, L.
Powiązania:: https://bibliotekanauki.pl/articles/243281.pdf
Data publikacji:: 2013
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: safety
forcing factor
transport process
Opis:: Transportation systems belong to the category of systems whose operation safety depends on many factors including: technical state of transport means, behavior of people involved in the system operation and maintenance and its environment, and finally the environmental factors. The system environment is referred to as all the elements, which, though not belonging to the system, are closely related to it. The environment, which is of interest for the authors of this paper, is the road infrastructure and atmospheric conditions. Construction solutions of the infrastructure, the road surface type and condition, temperature, visibility, precipitations, and time of day are referred to as external factors whose impact involves changes in safety of the transportation system operation. The impact of external factors can be in different forms and can affect the transport means as well as people involved in the system operation, especially the drivers. The literature provides a concept of excessive sense of a driver’s safety, which can be caused by good road conditions, dry and good road surface, etc. This is of particular importance in case of public transportation systems providing transport services on the territory of a town where the effects of external factors account for nearly 44% of adverse events causes. This study deals with identification of these factors and assessment of their influence on the analysed transportation system safety.
Źródło:: Journal of KONES; 2013, 20, 3; 47-53
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Analysis of the change of qualitative states of transportation system operation
Autorzy:: Muślewski, Ł
Knopik, L.
Woropay, M.
Powiązania:: https://bibliotekanauki.pl/articles/247633.pdf
Data publikacji:: 2014
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: transport
system operation quality
model
Markov chain
semi-Markov process
expected coast
Opis:: This paper deals with the problems connected with evaluation of a technical system and its being later used for decision making in order to provide complex technical systems with appropriate operation quality. The research object is a real municipal transportation system. The assessment quality of the systems operation is based on the changes of the systems features values. The features describe the operation of the systems operators, controlled technical objects and the environment influence. The assessment and the support the demand quality of the systems operation from the safety, efficiency, economic and reliability point of view is the basic factor of the executed exploitation process. The notion of a system operation quality has been defined, a scheme of an assessment model has been presented and a random process, providing the basis for evaluation of a technical system, has been developed. On the basis of carried out experimental tests there have been distinguished four states of a system operation quality reflecting intervals of values of grades that were characteristic for given time moments. A model of system operation qualitative state changes, based on Markov chain, has been considered in this paper. A system of equations has been determined for a distinguished Markov chain on the basis of which a mathematical model for assessment and control of selected types of transportation systems will be developed.
Źródło:: Journal of KONES; 2014, 21, 3; 251-257
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Profit optimalization in operation systems
Autorzy:: Knopik, L.
Migawa, K.
Wdzięczny, A.
Powiązania:: https://bibliotekanauki.pl/articles/258450.pdf
Data publikacji:: 2016
Wydawca:: Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:: Branching Poisson process
primary failure
secondary failures
gamma distribution
mean profit
hazard function
Opis:: The aim of this study is to analyse the effect of reducing the number of secondary damage to profit from the work of a technical object. Considering the criterion function that describes the average profit from the work of a technical object in the operation system. The study analyses a model of profit optimization, in which the design criterion function is based on the properties of Poisson branch process. Criterion function that describes the average gain is considered in the work at sufficiently general factors. Profit lifting model from the work of a technical facility is numerically exemplified. For the analysed electrical subsystem, intervals of time between the initial damage have exponential distribution, and between secondary damage - gamma distribution. In the presented example, the ability of profit optimization in operation systems of technical objects is demonstrated.
Źródło:: Polish Maritime Research; 2016, 1; 93-98
1233-2585
Pojawia się w:: Polish Maritime Research
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Semi-Markov model of quality state changes of a selected transport system
Autorzy:: Landowski, B.
Muślewski, Ł.
Knopik, L.
Bojar, P.
Powiązania:: https://bibliotekanauki.pl/articles/241811.pdf
Data publikacji:: 2017
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: transport system
efficiency
operation process
maintenance process
semi-Markov process
simulation tests
Opis:: The study deals with the problems connected with evaluation and analysis of transport systems operational quality. The research object is a real, sociotechnical system (of the type H-M-E) whose functional quality is affected by: operators, equipment and technical state of he operated vehicles and the environmental impact. A scheme of an assessment model was built on the basis of a developed concept of a system operational quality and a random process was defined to be used for the analysis. The assessment process involves investigating the variability degree of properties included in the resultant model in a given time and determining whether and to what degree the obtained values meet the requirements of the system appropriate operational quality. On the basis of the above assumptions and in result of experimental tests, four qualitative states of a transport system functioning, which represent intervals of values of the obtained grades in given time moments, were distinguished. The study presents a model of system operation qualitative state changes developed with the use of Markov chain inserted into a certain semi-Markov process. A graph and a matrix for probability of transition between the states were created and boundary distributions of the process were determined on the basis of experimentally obtained data. A system of equations was determined for the distinguished Markov chain, on the basis of which a mathematical model for assessment and control of operational quality of selected types of transport systems will be built.
Źródło:: Journal of KONES; 2017, 24, 4; 141-148
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Analysis of selected operating parameters of engine powered by a mixture of biocomponents and diesel oil
Autorzy:: Markiewicz-Patalon, M.
Muślewski, Ł.
Kaszkowiak, J.
Knopik, L.
Powiązania:: https://bibliotekanauki.pl/articles/244467.pdf
Data publikacji:: 2018
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: transport
means of transport
diesel oil
biocomponent
alternative fuels
Opis:: Reaching of high parameters of a drive unit and low pollution of the natural environment is considered to be the most desired effect of motorization. The use of the additive in the form of fatty acid methyl esters to the diesel oil, assumes lowering of harmful fuel gases’ emission and reaching high operating parameters of an engine, such as power and turning moment. Studies on the power output and the turning moment of an engine with self-ignition are presented in the study. The subject matter of the studies was a combustion engine with self-ignition of the power of 80 kW with the direct common rail system and turbo-compressor’s supercharging and with electromagnetic injectors. The tested engine was powered with diesel oil and the mixture of fatty acid methyl esters and the diesel fuel, in proportions 10%, 30% and 50% with an improver, at the standard settings of the fuel injection controllers. The vehicle used for the testing purposes, has been singled out with respect to the specific features, such as: universality of its use as a means of transportation and the opportunity of modification of the injection parameters, resistance to possible unfavourable consequences resulting from the use of the fuel mixture. The studies were conducted on a chassis test house, at full engine’s loading. The vehicle placed on the test house’s rollers, was strapped with belts to the foundation, and then accelerated up to the specific speed and subjected to loading standing in place. In such a manner, the road conditions were simulated. The obtained results of the tests were subject to the statistical analysis. From their analysis it results, that application of the mixture lowers the engine’s parameters to a degree unnoticeable at the time of its operation.
Źródło:: Journal of KONES; 2018, 25, 2; 239-244
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 11.

Tytuł:: Impact of extreme climate changes on the predicted crops in Poland
Wpływ ekstermalnych zmian klimatu na prognozowaną produkcję rolniczą
Autorzy:: Bojar, W.
Knopik, L.
Zarski, J.
Slawinski, C.
Baranowski, P.
Zarski, W.
Powiązania:: https://bibliotekanauki.pl/articles/35800.pdf
Data publikacji:: 2014
Wydawca:: Polska Akademia Nauk. Instytut Agrofizyki PAN
Opis:: The paper presents general characteristics of resources and outputs of agriculture in the Kujawsko-Pomorskie and Lubelskie Regions, based on statistical databases and literature review. Some specific features of the regions, with special consideration for the predicted extreme climate changes, are also included. Next, some statistically significant dependencies between the climatic parameters and yields of selected important crops in the abovementioned regions were worked out on the basis of empirical survey conducted in the University of Technology and Life Sciences, Bydgoszcz, and the Institute of Agrophysics in Lublin. Creating an appropriate method of forecasting long series of ten days without precipitation was necessary to find the desired dependencies. Third, some efforts were taken to make integrated assessments of forecast agricultural outputs influenced by climate extreme phenomena on the basis of the yield-precipitation relations obtained and on the data coming from wide area model regional outputs such as prices of farmland and produce.
W pracy przedstawiono ogólną charakterystykę zasobów rolnych w województwach kujawsko-pomorskim i lubelskim, oszacowanych na podstawie baz danych statystycznych i przeglądu literatury. Niektóre specyficzne cechy regionów, ze szczególnym uwzględnieniem przewidywanych ekstremalnych zmian klimatu, zostały również uwzględnione. Na tej podstawie oszacowano kilka istotnych statystycznie zależności pomiędzy parametrami klimatycznymi i rentownością wybranych najważniejszych upraw w wyżej wymienionych regionach. Zależności te zostały opracowane na podstawie badań empirycznych przeprowadzonych w Uniwersytecie Technologiczno-Przyrodniczym w Bydgoszczy oraz w Instytucie Agrofizyki PAN w Lublinie. Aby określić żądane zależności konieczne było użycie metody prognozowania długich serii dekad bez opadów. Zostały podjęte prace, aby zintegrowane oceny prognozowania wpływu zmian klimatu na zasoby rolne i rentowność gospodarstw opierały się na zależności plon – opad oraz o dane pochodzące z modeli regionalnych, takich jak ceny obszarów rolnych i plonów.
Źródło:: Acta Agrophysica; 2014, 21, 4
1234-4125
Pojawia się w:: Acta Agrophysica
Dostawca treści:: Biblioteka Nauki

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