Wyniki wyszukiwania - Biblioteka Nauki

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Oszacowanie stanu istniejącej konstrukcji na podstawie oceny wizualnej

100%

Niczyj J.

Inżynieria i Budownictwo

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1999

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tom R. 55, nr 5

287-290

PL

Zastosowano metodę zbiorów rozmytych modelujących stan wytężenia elementów. Przyjęto, że stan uszkodzenia elementów można wyrazić za pomocą zmiennych lingwistycznych. Wykorzystanie teorii zbiorów rozmytych w połączeniu z teorią niezawodności systemów zilustrowano na przykładzie konstrukcji prętowych.

EN

The paper defines the damage state of a structure in terms of fuzzy sets. In this study we have shown that by describing uncertainty of damage state of elements with fuzzy sets we may estimate the reliability of existing construction in case of incomplete or uncertain knowledge of its parameters. The major problem adressed in this paper is the presentation of fuzzy system failure probability by fuzzy linguistic variables and by a fuzzy number over an interval of confidence. The proposed method may be used in expert systems.

2

Wielokryterialna optymalizacja niezawodnościowa oraz szacowanie stanu technicznego konstrukcji prętowych z zastosowaniem teorii zbiorów rozmytych

100%

Niczyj J.

Prace Naukowe Politechniki Szczecińskiej. Katedra Teorii Konstrukcji

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2003

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tom Nr 581 (3)

3-229

EN

Optimum design as well as assessment of technical states of already civil existing structures are ones of the most important issues in engineering activities. Taking a decision on the effort state of the whole structure stands for a complicated problem, since it is difficult to proceed research related to an effort state or/and system damage. Information about the effort state of a structural member is often obtained on the basis of a visual evaluation or specialist's experiences. More frequently, in giving an opinion a verbal form is used. Such a linguistic qualification is defined as a qualitative valuation. In a decision problem, involved in expert computer codes for instance, linguistic information has to be expressed in terms of numerical data. Theory of fuzzy sets enables one to processing that linguistic information in order to make a decision that should be taken in complicated situations. Reliability-based multicriterion optimization is one of the more interesting engineering problems regarding structural designing and optimum decisions. This is because system properties and behaviour cannot be precisely observed, and statistical data related to uncertainties and imprecision data, related to, say, loading that the structure is subjected, are as a whole unavailable. A large number of optimum design problems define a set of constraints that are in conflict each other. On the other hand, the design constraints included in those problems are assumed as fuzzy (blurred) data. In many cases the values of required data can be given only in terms of their ranges, known as interval values. Also, their influences on taking a decision are expressed in the linguistic way only. Results followed from that interval analysis may be useful in qualitative assessments and taking decisions in order to improve utility states of the entire structure. It is shown in many examples of complex structures that the fuzzy sets may effectively be applied in a combination with the system reliability theory to estimate failure states. An original aspect of the work is thus the presentation of fuzzy failure probabilities with the help of fuzzy linguistic variables and interval analysis of fuzzy numbers. Operations on the intervals for each from the alpha-level of the fuzzy numbers are used. The alpha-level method allows one to calculate the probability of structural failure on various levels of uncertainties (fuzziness) of the system parameters. Descriptions of those uncertainties (inaccuracy) of the states of structural member damages in terms of the fuzzy sets enables one to estimate reliability of the existing structures in the case of insufficient system-parameter data. The alpha-levels method gives a parametric presentation of fuzzy design information and an evaluation of solutions on various levels in fuzzy analysis. An optimum solution depends on the value of the parameter alpha that denotes the achievement level through the allowable fuzzy quantities, as well as on the maximized value of the parameter lambda, which leads to general compromise solutions. In these solutions all the fuzzy objective functions and the fuzzy constraints are considered. Assessment of structural states is connected with the qualitative and quantitative evaluating. The fact that the last two evaluations are coupled is significant. An attempt to deal with the coupling aspect is introduced in Chapter 4 in the context of an original method, in which experimental research and expert evaluations of the structural effort states are combined to get various forms of a set of membership of function for appropriate visual evaluations. The expert evaluations are performed by questionnaire. To achieve agreement in those evaluations the method of fuzzy analysis of consensus in small groups is efficiently applied. As a result unique supports of linguistic values describing the technical state of structural members are given. These obtained evaluations are then assumed as a date-base in the next step of analysis. Effectiveness of the numerical algorithms worked-out is illustrated with the help of an optimum design problem of statically determinate and indeterminate trusses. Two conflict criteria defined for mass and displacement minima are defined in the objective functions. The system is subject to the stress and reliability constraints. It is assumed that the values of loading, admissible stresses and the probability of failure are described as fuzzy quantities. Chapter 9 shows reliability-based fuzzy multicriterion analysis of well-known aluminium 10-bar truss. An reliability scheme and same possible capacity forms of the truss are discussed. The probability of failure is computed basing upon a few dominant paths of failure that related to the margin of safety. The optimization techniques introduced in Chapters 8 and 9 stand for a new approach to optimum design analysis of truss systems. In this approach insufficient information taken into account can be leading to a more safe design point. All the solutions are obtained in these two chapters in the framework of the non-linear fuzzy programming. As shown by the author the calculations of the probability of failure and the determination of technical state of structure are based on visual assessments of the expert during the inspection process the problem formulated and solving algorithms presented in Chapters 10 are thus ones of the original aspects. A comparison of an technical state assessment of a structure through a long-time in intervals of repeated inspections is seemingly - by the author's knowledge - nonexisting in the literature. Moreover, it is particularity interesting when such a review is as most as specific the assessments were carried out for 7132 bars surfaces of the total length about 25000 m. More, the review is performed in the context of visual assessments, i.e. by linguistic values that are ones of the fuzzy variables. A comparison was made for the wooden roof of a hall in the 30-year interval, Chapter 11. The linguistic values followed from specific roofs trusses and obtained between two inspections, in 1964 and 1994, are compared via a number of histograms presented in this chapter. In author's opinion these histograms may stand for an inherent certification of the time state of either structural members or the entire structure whore at hand. These valuable data, when included in the recent data-base of structural states, and by periodical revives and comparisons (against previous states), enable the use in making proper decision.

3

Obliczenia statyczne konstrukcji kratowych za pomocą rozmytej metody elementów skończonych (RMES)

100%

Niczyj J.

Zeszyty Naukowe Politechniki Gdańskiej. Budownictwo Lądowe

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2006

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tom nr 58

263-268

EN

An fuzzy finite-element method (FFEM) for treating uncertain loads, cross sections of bars and Young's modulus in static structural problems is presented. By representing possible values as interval values, the fuzzy values of generalized nodal displacements and element stresses can be calculated in an efficient manner. This transforms the problem into a set of interval equations at each a-level. Example shows that the obtained interval values for a-level from the FFEM provide a sharp bound of nodal displacements, calculated by combined calculation of all values of uncertain parameters.

4

Wykorzystanie systemów wsparcia eksploatacji statków powietrznych do wykonania symulacji komputerowej ich procesu eksploatacji

63%

Niczyj J. , Bryzek A.

TTS Technika Transportu Szynowego

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2015

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tom R. 22, nr 12

2038--2043, CD

PL

W artykule został przedstawiony algorytm uzyskania harmonogramu dostaw części zamiennych dla floty statków powietrznych z dokładnym opisem propozycji wykorzystania danych zbieranych podczas procesu eksploatacji samolotów w systemach informatycznych wspierających ten proces. W artykule zostały przedstawione też wyniki działania algorytmu uzyskania harmonogramu zapasów dla przykładowych danych testowych.

EN

This article describes how the data collected in an IT support system during aircraft operation can be used to develop a delivery schedule of spare parts for an aircraft. The article describes also an algorithm used to create the delivery schedules, and contains schedules developed from test data.

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Opracowanie harmonogramu dostaw części zamiennych dla floty statków powietrznych przy wykorzystaniu symulacji komputerowej ich procesu eksploatacji

63%

Bryzek A. , Niczyj J.

TTS Technika Transportu Szynowego

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2015

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tom R. 22, nr 12

1797--1801, CD

PL

W artykule został opisany proces przygotowania harmonogramu dostaw części zamiennych dla statków powietrznych. W opisanym algorytmie harmonogram dostaw jest opracowany i oceniany przy wykorzystaniu symulacji komputerowej procesu eksploatacji zbioru statków powietrznych. Oprócz przedstawienia głównych punktów algorytmu w publikacji szczegółowo została opisana jedna z metod oceny przygotowanego harmonogramu.

EN

This article describes the process of aircraft replacement parts delivery schedule preparation. In the described algorithm the delivery schedule is developed and evaluated using a computer simulated process of operating a set of aircraft. Besides presenting the main features of the algorithm, this publication describes in details one of the methods of schedule evaluation.

6

Zarządzanie procesami eksploatacyjnymi z wykorzystaniem systemów informatycznego wsparcia eksploatacji statków powietrznych

51%

Kaleta R. , Niczyj J. , Bryzek A.

Autobusy : technika, eksploatacja, systemy transportowe

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2016

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tom R. 17, nr 12

1020--1024

PL

W artykule zostały opisane elementy zarządzania procesami eksploatacyjnymi z wykorzystaniem systemów informatycznych wsparcia eksploatacji statków powietrznych będących na wyposażeniu struktur realizujących i nadzorujących prace serwisowe na przykładzie samolotów F-16 i bezzałogowych statków powietrznych (BSP). W artykule zawarto przykłady wykorzystania systemów opracowanych w Instytucie Technicznym Wojsk Lotniczych, które zawierają cechy charakterystyczne uwzględniające specyfikę eksploatowanych statków powietrznych.

EN

The article describes elements of the management of operational processes with the use of IT systems supporting the operation of aircraft taking of F-16's and unmanned aerial vehicles (UAVs) as examples. The systems are used by supervisors performing maintenance work. The article gives examples of systems developed in the Air Force Institute of Technology and include characteristic features and the specifications of operated aircraft.

7

Rola funkcjonalnego modelu cyfrowego statku powietrznego w informatycznym systemie wsparcia eksploatacji

45%

Kaleta R. , Kołsut M. , Niczyj J. , Winiarski R. , Żegleń A.

Autobusy : technika, eksploatacja, systemy transportowe

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2018

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tom R. 19, nr 6

1196--1199, CD

PL

W artykule zostały opisane główne elementy informatycznego systemu wsparcia eksploatacji samolotów, ze szczególnym uwzględnieniem roli funkcjonalnego modelu cyfrowego statku powietrznego oraz wpływu jego składników na jakość zarządzania flotą. Omówiono i zobrazowano: 1) budowę struktury funkcjonalnej statku powietrznego i programu obsług w systemie informatycznym wsparcia eksploatacji; 2) systemy informatyczne wspierające eksploatację wojskowych statków powietrznych. Wykazano, że przy właściwej spójności i kompletności danych w informatycznym systemie wsparcia uzyskujemy wyższą jakość eksploatacji statków powietrznych, w tym poprawia się zarządzanie całą flotą, jakość obsług technicznych i bezpieczeństwo realizacji zadań lotniczych.

EN

The article describes the main elements of IT system supporting the maintenance of aircraft with special consideration of functional digital model of the aircraft and its components and influence on the quality of fleet management. Discussed and illustrated: 1) the construction of the functional structure of the aircraft and the maintenance program in the IT support system; 2) IT systems supporting the maintenance of military aircraft. It was shown that with proper coherence and completeness of data in the IT support system, we obtain a higher quality of aircraft maintenance, including improved management of the fleet, quality of technical services and safety of missions.