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Wyszukujesz frazę "lifetime" wg kryterium: Temat


Tytuł:
The influence of hydrogen concentration on positron lifetime and electrical resistivity in vanadium-hydrogen systems
Autorzy:
Pietrzak, R.
Szatanik, R.
Powiązania:
https://bibliotekanauki.pl/articles/146289.pdf
Data publikacji:
2010
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
positron lifetime
resistivity
V-H system
annihilation parameters
Opis:
Positron lifetime spectra and electrical resistivity of the vanadium-hydrogen systems with hydrogen concentration ranging from 0 to 0.29 at.H/at.V have been investigated. The range of hydrogen concentrations under investigation included the single alfa phase and a mixture of the alfa and beta phases of V-H system. The registered positron lifetime spectra were analysed by decomposition into two components. A distinct change in the annihilation parameters has been found after exceeding the boundary concentration of hydrogen in vanadium corresponding to the phase transition alfa (alfa+ beta). Correlation of changes in the parameters of the positron lifetime spectrum and in the electrical resistivity resulting from the changes in hydrogen concentration, has been revealed.
Źródło:
Nukleonika; 2010, 55, 1; 35-39
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of the durability of selected LED lamps
Autorzy:
Zalesińska, Małgorzata
Zabłocka, Julita
Pawlak, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/135480.pdf
Data publikacji:
2020
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
lifetime
LED lamps
non-directional LED lamps for household use
Ulbricht’s sphere
forecasting the luminous flux reduction
forecasted lifetime
Opis:
Luminous flux reduction during operation affects the operating lifetimes of LED lamps. Due to the very long lifetimes of LED sources, i.e. tens of thousands of hours, the lifetime declared by the manufacturer is most often determined by forecasting the luminous flux reduction. Lifetime forecasting is performed based on measuring the operating luminous flux reduction within a time frame of at least 6000 hours, every 1000 hours, followed by extrapolating the obtained results with a relevant exponential curve. This article presents the results of measurements of luminous flux changes taking place between 0 and 10,000 operating hours of several LED light sources. The obtained results were analyzed, and the lifetimes of the examined lamps were evaluated.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2020, 61 (133); 23-28
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Funkcjonowanie modelu sprzedażowego equity release w Polsce
Functioning of the sale model equity release in Poland
Autorzy:
Buzałek, Przemysław
Powiązania:
https://bibliotekanauki.pl/articles/653501.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
świadczenia dożywotnie
renta dożywotnia
umowa dożywocia
odwrócony kredyt hipoteczny
fundusze hipoteczne
lifetime benefits
lifetime pension
life contract
reverse mortgage
mortgage funds
Opis:
The aim of the article is to present the fuctioning of the sale model equity release in Poland. While analyzing lifetime benefits concluded with elderly people the autor noticed that the market of sale model equity release in Poland needs new legal regulations. Current law regulations are not enough to protect the interest of elderly people.
Artykuł traktuje o funkcjonowaniu modelu sprzedażowego equity release w Polsce. Wskazane są w nim podstawowe różnice między odwróconym kredytem hipotecznym a świadczeniami dożywotnimi, scharakteryzowane są umowy, w ramach których zawierane są świadczenia dożywotnie, opisana jest sytuacja na rynku w latach 2010–2017, a także zidentyfikowane są podstawowe problemy wynikające z braku odrębnych regulacji prawnych.
Źródło:
Finanse i Prawo Finansowe; 2019, 1, 21; 11-26
2391-6478
2353-5601
Pojawia się w:
Finanse i Prawo Finansowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gas turbine reliability model based on tangent hyperbolic reliability function
Autorzy:
Djeddi, A. Z.
Hafaifa, A.
Salam, A.
Powiązania:
https://bibliotekanauki.pl/articles/280120.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
reliability estimation
reliability algorithms
lifetime distribution
Weibull distribution
availability
Opis:
The present work deals with the exploration of a new model proposed for the reliability analysis of industrial production systems. This proposed model is mainly based on the tangent hyperbolic function, where the survival function is determined and used in the lifetime distribution modeling taking into account of estimation the parameters of the proposed function. On the other side, tests validation is performed using the real data of a gas turbine installation. The obtained results allow the modeling of damage effects, hence the prediction of the performance of the examined gas turbine using the proposed model gives good results in terms of validity.
Źródło:
Journal of Theoretical and Applied Mechanics; 2015, 53, 3; 723-730
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on preventive maintenance strategies and systems for in-service ship equipment
Autorzy:
Song, Tingxin
Tan, Taiyang
Han, Guochen
Powiązania:
https://bibliotekanauki.pl/articles/32887248.pdf
Data publikacji:
2022
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
preventive maintenance
FMEA
lifetime prediction
decision system
ship equipment
Opis:
With continuous improvements in the function and performance of ship equipment, mechanisms of failure have become more and more complicated. To avoid over-maintenance or under-maintenance in existing routine ship maintenance strategies, a ship-level method for repair decisions based on the preventive maintenance concept is proposed in this paper. First, the anticipated repair demand levels of key components are calculated using an improved failure mode and effects analysis (FMEA) method; second, a Weibull distribution model is established, and the parameters are estimated using the maximum likelihood estimation (MLE) to predict the characteristic life of the equipment; then, logical decision principles and rule-based reasoning (RBR) are used to determine the ship repair level and repair timing. Finally, the feasibility and application value of the proposed repair strategy were verified by case studies, and a ship-level system for repair decisions was established.
Źródło:
Polish Maritime Research; 2022, 1; 85-96
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance Evaluation of a Zone-based Three-level Heterogeneous Clustering Protocol for WSNs
Autorzy:
Rao, Sanapala Shanmukha
Shilpi
Kumar, Arvind
Powiązania:
https://bibliotekanauki.pl/articles/24200745.pdf
Data publikacji:
2023
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
clustering
heterogeneous
network lifetime
stability period
zone-based WSN
Opis:
This paper proposes a zone-based three-level heterogeneous clustering protocol (ZB-TLHCP) for heterogeneous WSNs. In ZB-TLHCP, the sensor field/region is divided into zones where super, advance, and normal nodes are deployed uniformly and randomly. The performance of the proposed ZB-TLHCP system is compared with that of zonal-stable election protocol (Z-SEP), distributed energy efficient clustering (DEEC), and threshold-based DEEC (TDEEC) protocol by varying the number of super and advance nodes, their energy levels for the fixed sensor field, and the total number of nodes. Matlab simulation results revealed that the proposed ZB-TLHCP solution performed better than Z-SEP, DEEC, and TDEEC protocols, as it increased the instability period, prolonged the network's lifetime, and achieved higher throughput values.
Źródło:
Journal of Telecommunications and Information Technology; 2023, 3; 85--93
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A method for estimating the probability distribution of the lifetime for new technical equipment based on expert judgement
Autorzy:
Andrzejczak, Karol
Bukowski, Lech
Powiązania:
https://bibliotekanauki.pl/articles/2038033.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
uncertainty
expert elicitation of lifetime
quantile function
Weibull distribution
Opis:
Managing the exploitation of technical equipment under conditions of uncertainty requires the use of probabilistic prediction models in the form of probability distributions of the lifetime of these objects. The parameters of these distributions are estimated with the use of statistical methods based on historical data about actual realizations of the lifetime of examined objects. However, when completely new solutions are introduced into service, such data are not available and the only possible method for the initial assessment of the expected lifetime of technical objects is expert methods. The aim of the study is to present a method for estimating the probability distribution of the lifetime for new technical facilities based on expert assessments of three parameters characterizing the expected lifetime of these objects. The method is based on a subjective Bayesian approach to the problem of randomness and integrated with models of classical probability theory. Due to its wide application in the field of maintenance of machinery and technical equipment, a Weibull model is proposed, and its possible practical applications are shown. A new method of expert elicitation of probabilities for any continuous random variable is developed. A general procedure for the application of this method is proposed and the individual steps of its implementation are discussed, as well as the mathematical models necessary for the estimation of the parameters of the probability distribution are presented. A practical example of the application of the developed method on specific numerical values is also presented.
Źródło:
Eksploatacja i Niezawodność; 2021, 23, 4; 757-769
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hybrid reliability modelling under general uncertainty
Autorzy:
Guo, R.
Cui, Y.
Thiart, C.
Guo, D.
Powiązania:
https://bibliotekanauki.pl/articles/2069636.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
uncertain measure
hybrid lifetime
uncertain parameter
average chance reliability
Opis:
The real world phenomena are often facing the co-existence reality of different formality of uncertainty and thus the probabilistic reliability modeling practices are very doubtful. Under complicated uncertainty environments, hybrid variable modeling is important in reliability and risk analysis, which includes Bayesian distributional theory, random fuzzy distributional theory, as well as fuzzy random distributional theory as special distribution families. In this paper, we define a new hybrid lifetime which is specified by a random lifetime distribution with an uncertain distributed parameter, which is called as random uncertain hybrid lifetime. We furthermore define the average chance distribution as a quality index for quantifying the hybrid lifetime and accordingly the average chance reliability is derived.
Źródło:
Journal of Polish Safety and Reliability Association; 2010, 1, 1; 115--122
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Technological solutions to extend the operating cycle of tools and industrial machinery
Autorzy:
Lukarski, Y.
Tashev, P.
Argirov, C.
Kondov, H.
Powiązania:
https://bibliotekanauki.pl/articles/391484.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Odlewnictwa
Tematy:
operational lifetime
new materials
overlay welding
thermo-chemical treatment
Opis:
One of the most significant problems that engineers and researchers face is the development of technological solutions to extend the exploitation cycle of tools and industrial machinery. The research shows there are a few possibilities to solve this problem: 1. Development of new materials of enhanced working characteristics compared to those currently used. An example of this is the introduction of new metals and alloys in the automotive industry, the mining industry, etc. 2. Preventive processing of assemblies and parts prior to their use consisting mainly in overlay welding with wear resistant layers or thermo-chemical surface treatment of the parts. 3. Recovering assemblies and parts after their resource has been depleted. This is mainly applied in the mining industry, road construction, etc. Worn-out tools are overlay welded and reused. It has been proven that the price of the recovered details is 2 to 20 times lower than that of the new ones. Moreover, it should be pointed out that the recovery saves energy and ore resources and thus a significant environmental impact is achieved.
Źródło:
Prace Instytutu Odlewnictwa; 2017, 57, 4; 253-258
1899-2439
Pojawia się w:
Prace Instytutu Odlewnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of heredity kernels and their influence on the life time of glass/polyester composites
Autorzy:
Olodo, E. T.
Adjovi, E. C.
Adanhounme, V.
Powiązania:
https://bibliotekanauki.pl/articles/955255.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
lepkosprężystość
parametry sprężyste
kompozyty
heredity kernels
viscoelastic parameters
lifetime
Opis:
One of the major problems encountered in prediction of hereditary viscoelastic behavior of polymeric composites is the determination of heredity kernels. This issue comes down to identification of the model characterizing the viscoelastic properties of these materials. The purpose of this work is to propose a model for prediction of viscoelastic nonlinear behavior of laminate composite with polyester matrix, through the study and analysis of heredity kernels and their influence on the life time of this material. Identification of this model required experimental determination at room temperature, of viscoelastic parameters of heredity kernels by macroscopic approach. These data provide predictive tools for establishment of the life time and long term stress limit under static complex loading for this type of material.
Źródło:
International Journal of Applied Mechanics and Engineering; 2014, 19, 4; 725-734
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kompetencje relacyjne młodych dorosłych nieposiadających i posiadających partnera życiowego
Autorzy:
Adamczyk, Katarzyna
Powiązania:
https://bibliotekanauki.pl/articles/637382.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
lifetime partner
partnered life
relational competences
single life
young adulthood
Opis:
The review of literature and studies let us suppose that a definite level of relational competences create greater or less possibilities to find a lifetime partner, and to maintain a relationship with him or her. In the article the findings of the research with 457 young single and partnered adults are presented. Their aim was to verify whether are there any differences between young single and partnered adults in the extent of level of relational competences, which indices were five six bonding behaviours (behaviours of psychic and physical closeness, impressive behaviours, behaviours on the behalf of a partner and a relationship, conciliatory behaviours, and sexual behaviours). Additionaly an association between level of relational competences and gender was analysed. It was assumed that lower level of competences will be characteristic of single adults. Moreover, it was hypothesized that females will possess a higher level of competences in comparison to males. Statistical analysis showed that the observed difference between single and partnered groups in the area of relational competences is statistically significant. Single individuals reveal a lower level of relational competences in the realm of the above-mentioned bonding behaviours. At the same time, gender showed to be a differentiating factor only in the area of competences concerned behaviours of psychic and physical closeness, and sexual behaviours.
Źródło:
Psychologia Rozwojowa; 2012, 17, 2; 87-100
1895-6297
2084-3879
Pojawia się w:
Psychologia Rozwojowa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimal credit period and ordering quantity for credit dependent trended demand and deteriorating items with maximum lifetime
Autorzy:
Shah, N. H.
Shah, D. B.
Patel, D. G.
Powiązania:
https://bibliotekanauki.pl/articles/970075.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
inventory
trended demand
trade credit
default risk
deterioration
maximum lifetime
Opis:
In this paper, an inventory system is analyzed regarding a trended demand. The seller offers its buyer a credit period for settling the account, which attracts more buyers and enhances market demand. However, the offer of credit period leads to default risk for the supplier. The units in inventory are deteriorating continuously and also have definite maximum lifetime. The aim is to maximize the profit of the retailer. Numerical examples are given to validate the developed mathematical model. Sensitivity analysis is performed to obtain the critical inventory parameters and deduce the managerial strategies.
Źródło:
Control and Cybernetics; 2015, 44, 2; 311-320
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Lifetime distributions with wave-like bathtub hazard
Autorzy:
Guo, R.
Thiart, C.
Cui, Y.
Guo, D.
Powiązania:
https://bibliotekanauki.pl/articles/2069543.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
lifetime distribution
hazard
bathtub hazard
likelihood function
maximum likelihood estimation
Opis:
In this paper, we argue the necessity of dealing with lifetime distributions with wave-like bathtub hazard function. Four classes of wave-like bathtub hazards are investigated. For preparing maximum likelihood estimation of the hazard parameters, the first-order and second-order partial derivatives are derived.
Źródło:
Journal of Polish Safety and Reliability Association; 2011, 2, 1; 115--122
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Weibull lifetime model with randomised failure-free time
Autorzy:
Sulewski, Piotr
Szymkowiak, Magdalena
Powiązania:
https://bibliotekanauki.pl/articles/2156948.pdf
Data publikacji:
2022-12-15
Wydawca:
Główny Urząd Statystyczny
Tematy:
Weibull lifetime model
randomised failure-free time
compound Weibull distributions
Opis:
The paper shows that treating failure-free time in the three-parameter Weibull distribution not a constant, but as a random variable makes the resulting distribution much more flexible at the expense of only one additional parameter.
Źródło:
Statistics in Transition new series; 2022, 23, 4; 59-76
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Scheduling Based Wireless Sensor Networks Integrated with IoT Environment
Autorzy:
Mahendran, N.
Powiązania:
https://bibliotekanauki.pl/articles/1193556.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Data Scheduling Schemes
Energy Efficient
IoT
Network lifetime
Sensor Network
Opis:
Wireless Sensor networks are widely adopt in military, target tracking, signal processing and monitoring applications like traffic and structural, the small and low cost unreliable sensor nodes in these applications uses batteries as the sole energy source. The energy efficiency becomes difficult task as the tiny and less weight battery act as source of each node. Scheduling the different category of data packets is a way to reduce the power consumption and increasing the lifetime of sensor nodes. The existing scheduling algorithms are not adapted to the environment changes. The basic FCFS (First Come First Serve) suffered by long delay while transmit the real time data packets. In DMP (Dynamic Multilevel Priority) real time data packets occupies highest priority, the remaining non real time data packets sent to lower priority level queues. Some real time task holds the resources for longer time, the other task have to wait, it makes the deadlock condition. The NJN (Nearest Job Next) will select the nearest requesting sensor node for service, real time packets have to wait long time. The proposed Adaptive weighted scheduling scheme changes the behavior of the network queue by adaptively changes the weights based on network traffic. Simulation results proof that, adaptive weighted scheduling algorithm works better than the FCFS and DMP data scheduling in terms of energy consumption and lifetime. Our future scheme to integrate Internet of Things (IoT) with the WSN to increase the performance of the wireless networks.
Źródło:
World Scientific News; 2016, 41; 116-127
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł

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