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Wyszukujesz frazę "Uncertainty;" wg kryterium: Temat


Tytuł:
Model‐free sliding mode control for a nonlinear teleoperation system with actuator dynamics
Autorzy:
Abdelwaheb, Henni Mansour
Abderrahmane, Kacimi
AEK, Belaidi
Powiązania:
https://bibliotekanauki.pl/articles/27314234.pdf
Data publikacji:
2023
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
model free sliding mode controller
teleoperation robotic system
actuator dynamics
time-varying delay
model uncertainty
Opis:
Teleoperation robotic systems control, which enables humans to perform activities in remote situations, has become an extremely challenging field in recent decades. In this paper, a Model Free Proportional‐Derivative Slid‐ ing Mode Controller (MFPDSMC) is devoted to the syn‐ chronization problem of teleoperation systems subject to actuator dynamics, time‐varying delay, model uncer‐ tainty, and input interaction forces. For the first time, the teleoperation model used in this study combines actuator dynamics and manipulator models into a single equation, which improves model accuracy and brings it closer to the actual system than in prior studies. Further, the proposed control approach, called Free, involves the simple mea‐ surement of inputs and outputs to enhance the system’s performance without relying on any knowledge from the mathematical model. In addition, our strategy includes a Sliding Mode term with the MFPD term to increase system stability and attain excellent performance against external disturbances. Finally, using the Lyapunov func‐ tion under specified conditions, asymptotic stability is established, and simulation results are compared and provided to demonstrate the efficacy of the proposed strategy.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2023, 17, 1; 69--77
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A semi-quantitative approach for verification of Safety Integrity Level requirements
Autorzy:
Abrahamsen, E. B.
Røed, W.
Powiązania:
https://bibliotekanauki.pl/articles/2069648.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
safety integrity level
probability of failure on demand
uncertainty
Opis:
A Safety Integrity Level (SIL) is a measure of performance required for a safety instrumented function. The IEC 61508/61511 standards define four safety integrity levels, SIL1 to SIL4, where SIL4 is the level with the most stringent requirements. For each safety integrity level there are many design requirements, including requirements for the probability of failure on demand (PFD). Verification of the required failure probabilisty is usually based on a quantitative analysis. In this paper we argue that such an approach is better replaced by a semi-quantitative approach. The approach acknowledges that the PFD requirement for a safety function cannot be adequately verified only by reference to an assigned probability number. There is a need for seeing beyond the probability number. The key aspect to include is related to uncertainty. Such an aspect is of ten ignored in verification of a safety integrity level. The offshore oil and gas industry is the starting point, but the discussion is to large extent general.
Źródło:
Journal of Polish Safety and Reliability Association; 2010, 1, 1; 1--6
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Lowering the uncertainty in fast noise measurement procedures
Autorzy:
Acciari, G.
Giannini, F.
Limiti, E.
Saggio, G.
Powiązania:
https://bibliotekanauki.pl/articles/308146.pdf
Data publikacji:
2002
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
noise
device characterisation
measurement errors
lowering uncertainty
Opis:
To completely characterise the noise behaviour of a two port device, four noise parameters F(min), R(n), G(opt) and B(opt) must be determined. This paper reports improvements in the uncertainty related to the above parameters, taking into account measurement errors due both to the limited instrument precision and connection repeatability. Results are reported for noise characterisation of 0.3 žm delta-doped HEMT devices by Alenia, demonstrating as the common hot-cold measurement procedure can result with an error confidence as low as 0.2% for all the noise parameters.
Źródło:
Journal of Telecommunications and Information Technology; 2002, 1; 29-33
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Analysis Of Tensile Test Results to Assess the Innovation Risk for an Additive Manufacturing Technology
Autorzy:
Adamczak, S.
Bochnia, J.
Kaczmarska, B.
Powiązania:
https://bibliotekanauki.pl/articles/221812.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
failure mode and effects analysis
static tensile test
measurement uncertainty
Opis:
The aim of this study was to assess the innovation risk for an additive manufacturing process. The analysis was based on the results of static tensile tests obtained for specimens made of photocured resin. The assessment involved analyzing the measurement uncertainty by applying the FMEA method. The structure of the causes and effects of the discrepancies was illustrated using the Ishikawa diagram. The risk priority numbers were calculated. The uncertainty of the tensile test measurement was determined for three printing orientations. The results suggest that the material used to fabricate the tensile specimens shows clear anisotropy of the properties in relation to the printing direction.
Źródło:
Metrology and Measurement Systems; 2015, 22, 1; 127-138
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimating the Approximation Uncertainty for Digital Materials Subjected to Stress Relaxation Tests
Autorzy:
Adamczak, S.
Bochnia, J.
Powiązania:
https://bibliotekanauki.pl/articles/220966.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
digital materials
stress relaxation
approximation uncertainty
Opis:
The main aim of the study was to determine the goodness of fit between the relaxation function described with a rheological model and the real (experimental) relaxation curves obtained for digital materials fabricated with a Connex 350 printer using the PolyJet additive manufacturing technology. The study involved estimating the uncertainty of approximation of the parameters of the theoretical relaxation curve. The knowledge of digital materials is not yet sufficient; their properties are not so well-known as those of metallic alloys or plastics used as structural materials. Intensive research is thus required to find out more about their behavior in various conditions. From the calculation results, i.e. the uncertainty of approximation of the relaxation function parameters, it is evident that the experimental curves coincide with the curves obtained by means of the solid model when the approximation uncertainty is taken into account. This suggests that the assumed solid model is well-suited to describe a real material.
Źródło:
Metrology and Measurement Systems; 2016, 23, 4; 545-553
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimating the uncertainty of tensile strength measurement for a photocured material produced by additive manufacturing
Autorzy:
Adamczak, S.
Bochnia, J.
Kaczmarska, B.
Powiązania:
https://bibliotekanauki.pl/articles/221806.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
static tensile test
measurement error
measurement uncertainty
Opis:
The aim of this study was to estimate the measurement uncertainty for a material produced by additive manufacturing. The material investigated was FullCure 720 photocured resin, which was applied to fabricate tensile specimens with a Connex 350 3D printer based on PolyJet technology. The tensile strength of the specimens established through static tensile testing was used to determine the measurement uncertainty. There is a need for extensive research into the performance of model materials obtained via 3D printing as they have not been studied sufficiently like metal alloys or plastics, the most common structural materials. In this analysis, the measurement uncertainty was estimated using a larger number of samples than usual, i.e., thirty instead of typical ten. The results can be very useful to engineers who design models and finished products using this material. The investigations also show how wide the scatter of results is.
Źródło:
Metrology and Measurement Systems; 2014, 21, 3; 553-560
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stress and strain measurements in static tensile tests
Autorzy:
Adamczak, S.
Bochnia, J.
Kundera, C.
Powiązania:
https://bibliotekanauki.pl/articles/221886.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
static tensile strength test
measurement error
measurement uncertainty
Opis:
The paper deals with the accuracy of measurements of strains (elongation and necking) and stresses (tensile strength) in static room-temperature tensile strength tests. We present methods for calculating measurement errors and uncertainties, and discuss the determination of the limiting errors of the quantities measured for circular and rectangular specimens, which is illustrated with examples.
Źródło:
Metrology and Measurement Systems; 2012, 19, 3; 531-540
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rola komunikacji w procesie planowanych zmian organizacyjnych
The Role of Communication in Planned Organizational Change Processes
Autorzy:
Adamska, Krystyna
Powiązania:
https://bibliotekanauki.pl/articles/599116.pdf
Data publikacji:
2013-04-15
Wydawca:
Instytut Pracy i Spraw Socjalnych
Tematy:
zmiana organizacyjna
komunikacja
relacje
informacja
niepewność
zaufanie
organizational change
communication
relations
information
uncertainty
trust
Opis:
W artykule przedstawiono podział procesu wprowadzania planowanych zmian organizacyjnych na trzy etapy, ze względu na funkcje, jakie pełni w nim komunikacja, a mianowicie: relacyjną, informacyjną oraz rozwojową. Etap poprzedzający wprowadzenie planowanej zmiany akcentuje znaczenie relacyjnej funkcji komunikacji. Kształtowanie relacji cechujących się zaufaniem powoduje, że wzrasta gotowość do zmian. Rzetelna i wiarygodna informacja, przekazywana na etapie realizacji zmian, sprzyja redukcji niepewności, wywołanej zmianami. Etap następujący po przeprowadzanych zmianach wymaga wysokiej jakości komunikacji, w której jej aspekt informacyjny i relacyjny zostają zintegrowane na rzecz procesów uczenia się nowych wzorców komunikacyjnych i nowych sposobów działania. Ponieważ komunikacja jest podstawowym narzędziem integracji zbiorowych działań w organizacji, jej rola w procesie planowanych zmian ma znaczenie fundamentalne.
This article presents the three–stage implementation process for organizational changes where the role of communication is a key—relational, informational, and developmental. The relational function of communication is stressed in the stage preceding the introduction of planned changes. Building relations based on trust fosters a readiness for change. Reliable and trustworthy information provided during the implementation stage reduces uncertainty evoked by changes. The post implementation stage demands high quality communication. In it, the informational and relational aspects are integrated to facilitate learning processes aimed at new communication models and new ways of acting. Since communication is a basic tool in the integration of the collective actions in the organization, its role in the planned change process is of fundamental importance.
Źródło:
Zarządzanie Zasobami Ludzkimi; 2013, 2(91); 27-36
1641-0874
Pojawia się w:
Zarządzanie Zasobami Ludzkimi
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Water Resources Uncertainty in Yewa River Basin, Ogun state, South-West Nigeria
Autorzy:
Adeaga, O. A.
Bello, A. A.
Akinbaloye, T.
Powiązania:
https://bibliotekanauki.pl/articles/1066168.pdf
Data publikacji:
2019
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Climatic variability
Drainage basin
Uncertainty
WEAP
Water resources
Yewa River
Opis:
The paper examined water resources insecurity arising from climatic change and variability, coupled with increased population and economic development in in Yewa basin, with a view to understanding the relationship between climatic variables and hydrological parameters operating within the basin. Thus, the study entails assessment of the effects of climate change and variability on water resources and its implication on both the physical environment and the hydrological regime, using the water evaluation and planning (WEAP) system model. Data employed included water supply and demand for Domestic, Commercial, Industrial and Agriculture, as well as climatic data (rainfall and Temperature) and runoff. As revealed by the Scenario fabrication, 45.24% of the annual water requirement within Yewa Basin is not met, with water potentials of Annual mean discharge of 3682.46 m3/s (±830.1) and Annual mean rainfall of 1106.26m (±475.25), and with coefficients of variation of 40.88 and 73.73, respectively. This deficit calls for an appropriate water resources management mechanism to be put into use in Yewa Basin.
Źródło:
World Scientific News; 2019, 131; 37-53
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Neutrosophic compromise programming approach for multiobjective nonlinear transportation problem with supply and demand following the exponential distribution
Autorzy:
Adhami, Ahmad Yusuf
Faizan, Mohd
M, Anas
Powiązania:
https://bibliotekanauki.pl/articles/2175845.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
fuzzy approach
multiobjective optimization
supply chain
transportation
uncertainty
Opis:
Decision-making is a tedious and complex process. In the present competitive scenario, any incorrect decision may excessively harm an organization. Therefore, the parameters involved in the decision-making process should be looked into carefully as they may not always be of a deterministic nature. In the present study, a multiobjective nonlinear transportation problem is formulated, wherein the parameters involved in the objective functions are assumed to be fuzzy and both supply and demand are stochastic. Supply and demand are assumed to follow the exponential distribution. After converting the problem into an equivalent deterministic form, the multiobjective problem is solved using a neutrosophic compromise programming approach. A comparative study indicates that the proposed approach provides the best compromise solution, which is significantly better than the one obtained using the fuzzy programming approach.
Źródło:
Operations Research and Decisions; 2022, 32, 3; 1--15
2081-8858
2391-6060
Pojawia się w:
Operations Research and Decisions
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Infinite dimensional uncertain dynamic systems on Banach spaces and their optimal output feedback control
Autorzy:
Ahmed, N.
Powiązania:
https://bibliotekanauki.pl/articles/729515.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
partially observed
uncertain systems
stochastic systems
operator valued functions
feedback operators
existence of optimal operators in the presence of uncertainty
Opis:
In this paper we consider a class of partially observed semilinear dynamic systems on infinite dimensional Banach spaces subject to dynamic and measurement uncertainty. The problem is to find an output feedback control law, an operator valued function, that minimizes the maximum risk. We present a result on the existence of an optimal (output feedback) operator valued function in the presence of uncertainty in the system as well as measurement. We also consider uncertain stochastic systems and present similar results on the question of existence of optimal feedback laws.
Źródło:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization; 2015, 35, 1; 65-87
1509-9407
Pojawia się w:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Topological dual of $B_∞(I, ₁(X,Y))$ with application to stochastic systems on Hilbert space
Autorzy:
Ahmed, N.
Powiązania:
https://bibliotekanauki.pl/articles/729390.pdf
Data publikacji:
2009
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
representation theory
topological dual
finitely additive operator-valued measures
polish space
Hilbert space
stochastic systems
structural control
uncertainty abatement
Opis:
In this paper, we prove that the topological dual of the Banach space of bounded measurable functions with values in the space of nuclear operators, furnished with the natural topology, is isometrically isomorphic to the space of finitely additive linear operator-valued measures having bounded variation in a Banach space containing the space of bounded linear operators. This is then applied to a stochastic structural control problem. An optimal operator-valued measure, considered as the structural control, is to be chosen so as to minimize fluctuation (volatility). Both existence of optimal policy and necessary conditions of optimality are presented including a conceptual algorithm.
Źródło:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization; 2009, 29, 1; 67-90
1509-9407
Pojawia się w:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Probabilistic mesoscale analysis of concrete beams subjected to flexure
Autorzy:
Al-Jelawy, Haider M.
Al-Rumaithi, Ayad
Fadhil, Aqeel T.
Al-Sherrawi, Mohannad H.
Powiązania:
https://bibliotekanauki.pl/articles/2106443.pdf
Data publikacji:
2021
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
belka betonowa
analiza probabilistyczna
mezoskala
concrete beam
flexure
grading curve
mesoscale
probabilistic analysis
uncertainty
Opis:
In this paper, the probabilistic behavior of plain concrete beams subjected to flexure is studied using a continuous mesoscale model. The model is two-dimensional where aggregate and mortar are treated as separate constituents having their own characteristic properties. The aggregate is represented as ellipses and generated under prescribed grading curves. Ellipses are randomly placed so it requires probabilistic analysis for model using the Monte Carlo simulation with 20 realizations to represent geometry uncertainty. The nonlinear behavior is simulated with an isotropic damage model for the mortar, while the aggregate is assumed to be elastic. The isotropic damage model softening behavior is defined in terms of fracture mechanics parameters. This damage model is compared with the fixed crack model in macroscale study before using it in the mesoscale model. Then, it is used in the mesoscale model to simulate flexure test and compared to experimental data and shows a good agreement. The probabilistic behavior of the model response is presented through the standard deviation, moment parameters and cumulative probability density functions in different loading stages. It shows variation of the probabilistic characteristics between pre-peak and post-peak behaviour of load-CMOD curves.
Źródło:
International Journal of Applied Mechanics and Engineering; 2021, 26, 3; 12--27
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The power of ADKAR change model in innovative technology acceptance under the moderating effect of culture and open innovation
Autorzy:
Ali, Muhammad Ahmad
Zafar, Usman
Mahmood, Asif
Nazim, Muhammad
Powiązania:
https://bibliotekanauki.pl/articles/2021479.pdf
Data publikacji:
2021
Wydawca:
Wyższa Szkoła Logistyki
Tematy:
ADKAR change model
reinforcement
uncertainty avoidance
perceived ease of use
inbound and outbound open innovation
perceived usefulness
model ADKAR
wzmocnienie
unikanie niepewności
łatwość użytkowania
Opis:
Background: Continuous change is a vital factor for organization’s sustainable growth and success. The implementation of modern information technology in business has become a core need of the hour. This study endeavours to answer how to cope with resistance to change when implementing new technology in the banking sector. A theoretical model has been developed with the blend of ADKAR change model, Technology Acceptance Model (TAM), and Hofstede dimensions of national culture to investigate the impact of the ADKAR change model on Technology Acceptance under the moderation of two national culture’s dimensions. Materials and Methods: In order to collect data, 500 self-administered questionnaires were dropped personally in five major banks of five cities of Pakistan using the convenience-based employee intercept sampling technique. The validated response rate was 68% by having 340 fit questionnaires for analysis using covariance-based structure equation modelling with the help of SmartPLS. Results: The results uncover the significant existence of covariance between dimensions of the ADKAR change model and technology acceptance model. The findings are statistically significant, inferring the influential role of change management on technology adoption. Conclusion: The study results provide promising implications based on these conclusions and findings for both theoretical aspects of these different models and practitioners.
Źródło:
LogForum; 2021, 17, 4; 485--502
1734-459X
Pojawia się w:
LogForum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rankingi w warunkach niepewności
Rankings in conditions of uncertainty
Autorzy:
Ameljańczyk, A.
Powiązania:
https://bibliotekanauki.pl/articles/208395.pdf
Data publikacji:
2014
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
relacja preferencji
elementy ekstremalne
klastry rankingowe
model niepewności Hurwicza
ranking w warunkach niepewności
preference relation
extreme elements
ranking clusters
Hurwicz model of uncertainty
ranking under uncertainty
Opis:
Praca dotyczy procedur rankingowych zbioru obiektów, których jakość (użyteczność) zmienia się w zależności od występowania warunków, których rozkład prawdopodobieństwa na ogół nie jest znany. Procedura polega na rekurencyjnym wyznaczaniu elementów ekstremalnych zbioru na podstawie przyjętej relacji preferencji jakościowych w warunkach niepewności. Efektem jej działania jest podział zbioru na jakościowe klastry rankingowe, a w konsekwencji ranking elementów analizowanego zbioru w warunkach niepewności. W pracy rozważono model preferencji Hurwicza i jego przypadki szczególne, omówiono własności uzyskiwanych rankingów oraz metody ich wyznaczania.
The work concerns the procedures for ranking a set of objects whose value (utility) varies depending on the occurrence of the conditions for the probability distribution is not generally known. The procedure involves determining the recursive extreme elements of a set on the basis of its qualitative preference relations under uncertainty. The result of the operation is to divide a set of the qualitative ranking clusters and consequently the ranking of elements analyzed under conditions of uncertainty. The study considered Hurwicz model preferences and special cases are discussed ownership rankings obtained and the methods of their determination.
Źródło:
Biuletyn Wojskowej Akademii Technicznej; 2014, 63, 4; 29-42
1234-5865
Pojawia się w:
Biuletyn Wojskowej Akademii Technicznej
Dostawca treści:
Biblioteka Nauki
Artykuł

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