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Tytuł:
The technical object reliability evaluation based on the parametric and momentary failures
Autorzy:
Lindstedt, P.
Manerowski, J.
Borowczyk, H.
Powiązania:
https://bibliotekanauki.pl/articles/242760.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
reliability
Weibull function
parametric failure
momentary failure
Opis:
The presented paper concerns with the technical object reliability evaluation based on the parametric and momentary failures during the process of object operating. The real world data observation shows that in the case of high quality technical objects the catastrophic failure events are too rare to the credible evaluation of the object’s reliability. For that reason, the parametric and momentary failures are in the centre of attention in this paper. The set of analysed failures was obtained with the classifiers of the field data provided by the monitoring system (the failure alarms) and the diagnostic system (the functional and technical condition parameters deviation). The changes of the functioning condition potential are used to determine the symptoms of momentary failures and the changes in the potential of the technical condition to determine the symptoms of parametric failures (non-total). The assumed reliability characteristics model has the form R(t) = f(_, Rb(t), Rc(t)), (where: Rb(t) and Rc(t) – the estimators of reliability for parametric and momentary failures, symbol ‘_’ denotes catastrophic failures not covered). For the identification of R (t) as an analytical function, the estimators are computed with the field data. The Weibull distribution function due to its flexibility is often used. Such is the case in this paper. Two parameters a and b known as the scale and the shape parameters are estimated with the computerized procedure realizing least-square method. The presented examples show good fit quality even for small set of data.
Źródło:
Journal of KONES; 2016, 23, 2; 239-246
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fertilization failure and early embryonic mortality as a major cause of reproductive failure in cattle: A review
Autorzy:
Sayid, Ali
Powiązania:
https://bibliotekanauki.pl/articles/1193470.pdf
Data publikacji:
2021
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Bovine
Embryo mortality
Fertilization failure
Reproductive failure
Opis:
Reproductive failure in lactating dairy cows is a significant limitation to the dairy industry. Fertilization failure, Embryonic or fetal losses are major contributors to that limitation. The objective of this review was to determine cause of fertilization failure and early embryonic mortality in cattle. Fertilization failure and embryo mortality is a major cause of economic loss in dairy production systems. Direct effects of fertilization failure and embryo mortality are reflected in reduced conception rates with consequent effects on efficiency, production and profitability. Embryonic loss can be early or late .The major component of embryo loss occurs before day 16 following breeding with emerging evidence of greater losses before day 8 in high producing dairy cows. Late embryo loss causes serious economic losses because it is often recognized too late to rebreed females. Various factors can be a cause for fertilization failure and embryonic mortality. The major cause includes genetic, environmental, endocrine, infectious nutritional factors. More balanced breeding strategies with greater emphasis on fertility, feed intake and energy must be developed. There is a range of easily adoptable management factors that can either directly increase in embryo survival or ameliorate the consequences of low embryo survival rates. The correction of minor deficits in several areas can have a substantial overall effect on herd reproductive performance.
Źródło:
World Scientific News; 2021, 158; 59-71
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mean time to failure for periodic failure rate
Autorzy:
Tanguy, C.
Powiązania:
https://bibliotekanauki.pl/articles/2069664.pdf
Data publikacji:
2009
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
reliability
mean time to failure
periodic failure rate
Opis:
The paper is concerned with the determination of the Mean Time To Failure (MTTF) in configurations where the failure rate is periodical. After solving two configurations exactly, we show that when the period of the failure rate oscillations is small with respect to the average failure rate, the MTTF is essentially given by the inverse of the average failure rate, give or take corrections that can be expressed analytically. This could be helpful in the description of systems the environment of which is subject to changes.
Źródło:
Journal of Polish Safety and Reliability Association; 2009, 2; 361--366
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Likelihood of a failure of a damming structure
Autorzy:
Opyrchał, L.
Hrabowski, W.
Jankowski, W.
Powiązania:
https://bibliotekanauki.pl/articles/241512.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
failure risk
dam
Opis:
Having an analysis of real breakdowns and damages in Polish damming structures as a basis, and assuming the probability of controlling freshet as a unit, one can calculate the probability of failure of a hydro-technical structure, due to failure of the base, the draining system, anti-filtering safety appliances, the body or the abutments. The results obtained af-ford an estimation of failure risk at any moment of the structure's opera-tion and an estimation of the overall failure probability. The calculations were carried out for all dam classes. When the dam's elements are in good condition, the overall failure probability is by one order of magni-tude greater than the probability that a controlling freshet will occur.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2003, 50, 2; 141-146
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
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
Artykuł
Tytuł:
A method for assessing of ship fuel system failures resulting from fuel changeover imposed by environmental requirements
Autorzy:
Kowalak, Przemysław
Myśków, Jarosław
Tuński, Tomasz
Bykowski, Dariusz
Borkowski, Tadeusz
Powiązania:
https://bibliotekanauki.pl/articles/2038055.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
failure frequency
fuel changeover
fuel system failure
emission control area
Opis:
Environmental regulations instigated the technological and procedural revolution in shipping. One of the challenges has been sulfur emission control areas (SECA) and requirement of fuel changeover. Initially, many reports anticipated that new grades of low sulfur fuels might increase various technical problems in ship operation. This research develops a simple and easy to use method of the failure severity and intensity assessment in relation to fuel changeover. The scale of failure rate in the ship’s fuel system was evaluated qualitatively and quantitively, using developed failure frequency indicator and the time between failure. Based on 77 records of fuel system failures collected on seven ships, it has been found that frequency of failures related to SECA fuel changeover is on average nearly three times higher compared to the rest of sailing time. Their severity did not significantly change, but the structure of failures changed considerably. The method and presented results may help in improvement of ship’s systems design and on-board operational procedures.
Źródło:
Eksploatacja i Niezawodność; 2021, 23, 4; 619-626
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Towards a High Reliable Enforcement of Safety Regulations - A Workflow Meta Data Model and Probabilistic Failure Management Approach
Autorzy:
Thimm, H. H.
Powiązania:
https://bibliotekanauki.pl/articles/136152.pdf
Data publikacji:
2016
Wydawca:
EEEIC International Barbara Leonowicz Szabłowska
Tematy:
Environmental Health and Safety
workflow management
workflows
failure detection
failure prediction
Opis:
Today’s companies are able to automate the enforcement of Environmental, Health and Safety (EH&S) duties through the use of workflow management technology. This approach requires to specify activities that are combined to workflow models for EH&S enforcement duties. In order to meet given safety regulations these activities are to be completed correctly and within given deadlines. Otherwise, activity failures emerge which may lead to breaches against safety regulations. A novel domain-specific workflow meta data model is proposed. The model enables a system to detect and predict activity failures through the use of data about the company, failure statistics, and activity proxies. Since the detection and prediction methods are based on the evaluation of constraints specified on EH&S regulations, a system approach is proposed that builds on the integration of a Workflow Management System (WMS) with an EH&S Compliance Information System. Main principles of the failure detection and prediction are described. For EH&S managers the system shall provide insights into the current failure situation. This can help to prevent and mitigate critical situations such as safety enforcement measures that are behind their deadlines. As a result a more reliable enforcement of safety regulations can be achieved.
Źródło:
Transactions on Environment and Electrical Engineering; 2016, 1, 4; 19-28
2450-5730
Pojawia się w:
Transactions on Environment and Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The study on algorithm for identification the fatigue crack length of compressor blade based on amplitude-frequency resonant characteristics
Autorzy:
Lichoń, D.
Bednarz, A.
Powiązania:
https://bibliotekanauki.pl/articles/243684.pdf
Data publikacji:
2017
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
fatigue failure
crack length
compressor blade
aircraft engine
failure identification algorithm
Opis:
The article is focused on building the algorithm for identification the fatigue crack length in the first stage of compressor blade of the helicopter PZL-10W turbo-shaft engine. The fatigue wear of compressor blade is a process in which the fatigue crack begins at the structural notch of the working part. For compressor blade, the crack starts at the leading edge and progress along the blade chord. Due to working conditions, the compressor blades are referred to as critical components. The helicopter rotor downwash can easily lift particles form the ground that may cause damages in the compressor section. Aircraft engines are designed so that the rotational speed of impeller remains below the resonant frequency. However, the pulsation of working medium or mechanical vibrations may cause temporary increase of vibration frequency. The appearance of structural notch combined with temporary increase of vibrations may initiate the fatigue failure. The works undertaken at the Department of Aircraft and Aircraft Engines, Rzeszow University of Technology provided a wide spectrum of research data of amplitude-frequency (A-F) characteristics of 1st stage of compressor blade. For different crack lengths, the fatigue tests of resonant frequency and asymmetry of A-F characteristics were acquired. The crack lengths were measured by fluorescent or infrared mapping method. The aim of the article is to develop the numerical method for identification of crack length of compressor blade basing on A-F characteristics. The studies on A-F characteristics in order to find correlations between crack length, resonant frequency and characteristics asymmetry were performed. The next step was to build the algorithm for identification the crack length when only A-F characteristic is known. The article contains the description of researches background, A-F characteristics unique features, algorithm detailed methods of work and sample use of algorithm in identification the crack length.
Źródło:
Journal of KONES; 2017, 24, 4; 157-164
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Factors of Failure in Innovative Business Activities in Sanandaj
Autorzy:
Abdolmalaki, Kazhal
Gholipour, Rahmatolah
Ma’roofi, Fakharadin
Powiązania:
https://bibliotekanauki.pl/articles/1190165.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Innovation
failure of innovative business activities
factors of innovative activity failure
Opis:
The aim of this study was to analyze the reasons affecting the failure of innovative business activities in Sanandaj. The population of this research consisted of 150 managers and experts who did not have innovation in their businesses or had some kind of unsuccessful experience in this field. Mostly, the activities of these businesses were in the field of metal industry, packaging, textile, wood and automotive downstream industries. Among this population a sample of 105 people were chosen by using simple random sampling method. The aim of this study is functional and the data collection was descriptive and correlational. The main tools for collecting data were library resources and standard innovation failure factors questionnaire Wyckoff, and innovation questionnaire, on the basis of Likert scale. Data obtained from the questionnaire were analyzed by using descriptive statistics (mean, percentage, and standard deviation), inferential statistics (Pearson correlation and Structural Equation Modeling (SEM)) and SPSS and AMOS software. Results of the conducted analysis showed that all six factors are effective in the failure of innovative business activities in the city of Sanandaj. The results of Structural Equation Modeling indicated that poor management is more effective than other factors in the failure of activities.
Źródło:
World Scientific News; 2016, 42; 306-316
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation into a Potential Reduction of FMEA Efforts Using Action Priority
Autorzy:
Barsalou, Matthew
Powiązania:
https://bibliotekanauki.pl/articles/2201159.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
FMEA
failure modes and effects analysis
risk analysis
failure prevention
quality
Opis:
FMEAs have been prioritized using RPN; however, a new standard has introduced AP for prioritization. This study seeks to determine if the number of required improvement actions increases, decreases, or stays the same when using AP in place of RPN. Statistical software was used to simulate 10,000 combinations of severity, occurrence, and detection. Both AP and RPN were calculated for the 10,000 combinations. Statistical hypothesis testing was performed to determine if there was a difference between RPNs when sorted by AP and to determine if there was a difference in actions required using RPN or AP. There is a statistically significant difference between RPNs when sorted by high, medium, and low AP. Using an RPN threshold equal to or greater than 100 would result in no change in the number of actions required if prioritizing by high and medium, but would result in fewer actions required if only high is used.
Źródło:
Management and Production Engineering Review; 2022, 13, 4; 59--71
2080-8208
2082-1344
Pojawia się w:
Management and Production Engineering Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of continuous damage deactivation on yield and failure surfaces
Autorzy:
Cegielski, M.
Ganczarski, A.
Powiązania:
https://bibliotekanauki.pl/articles/387329.pdf
Data publikacji:
2007
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
damage
damage deactivation
failure
Opis:
This article deals with the modeling of the continuous damage deactivation affected yield surfaces of copper and failure surfaces of mortar, from the viewpoint of continuum damage mechanics. The concept of damage deactivation is adapted to Tresca-Guest and Huber-Mises surfaces and two models are presented: the classical discontinuous one, in which microcracks close instantaneously, and the new continuous one, in which they close gradually. The results for both models are compared and verified in order to achieve the best fitting the experimental data. Detailed quantitative and qualitative analysis of obtained solutions confirms the necessity and correctness of an application of the continuous damage deactivation concept.
Źródło:
Acta Mechanica et Automatica; 2007, 1, 2; 15-18
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Engineering availability of aircrafts
Autorzy:
Lewitowicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/242226.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
transport
aircraft
diagnostic
failure
Opis:
Engineering availability and operational readiness of an aircraft are requisites for its ability to operate. After the aircraft has been supplied, both features determine airworthiness of the aircraft, in compliance with the ARC (Airworthiness Review Certificate). Improvement in methods of maintaining the aircraft availability proceeds in compliance with the MSG (Maintenance Steering Group) rules. The paper has been intended to outline the process of maintaining the engineering availability of the aircraft, with account taken of: aircraft maintainability, importance of the engineering diagnostics, and evaluation ratesfor dijferent maintenance patterns. Maintaining technical ability/ airworthiness of an aircraft, ground service of aircrafts, service-friendliness of an aircraft, unfitness and damages to an aircraft, ground diagnostic andprovision equipment for A-380, computer aided verification of an inspection of a front undercarriage (B) of an aircraft (A) and service of the B-787 aircraft (C), percentage for composite material portion in the structure of some aircrafts and helicopters, positions of composite material airframe elements in B-75 7/7 67, B-777, B-787 are presented in the paper.
Źródło:
Journal of KONES; 2009, 16, 2; 255-262
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of fishing basin construction on the behaviour of a footbrdge over the port channel
Autorzy:
Pyrzowski, Ł.
Miśkiewicz, M.
Chróścielewski, J.
Powiązania:
https://bibliotekanauki.pl/articles/260413.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
footbridge
port basin
failure
Opis:
The paper analyses possible causes of failure of the rotating footbridge over the Ustka port channel. In July, 2015, strange behaviour of this object was observed in the form of excessive vibrations of bridge platform suspension rods, with the accompanying acoustic effects. A preliminary geotechnical analysis has revealed that this destructive effect was caused by the nearby construction works, namely construction of a fishing basin and communication routes in the area close to the bridge, which affected the bridge lashing rod foundation settings. Ground vibrations generated by certain construction activities were likely to have direct impact on decreasing the bearing capacity of these rods and increasing the susceptibility od the piles to extraction. After detecting the above problems in bridge operation, its geodetic monitoring was started. The data recorded during this monitoring, along with the results of force measurements in the rods, have made the basis for a series of numerical simulations, performed in the Finite Element Method (FEM) formalism. The bridge structure was analysed in the conditions defined as the emergency state. Extreme efforts of bridge elements and its dynamic characteristics were examined. A possible source of strange behaviour of the footbridge during its operation which was recognised during these simulations was the coincidence of the global natural frequency of the entire bridge structure with local vibrations of suspension rods, at the frequency approximately equal to 1 Hz. This situation was likely to lead to the appearance of the so-called internal resonance phenomenon. As a final conclusion of the research, recommendations were formulated on possible object oriented corrective actions.
Źródło:
Polish Maritime Research; 2017, S 1; 182-187
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Postoperative Acute Respiratory Failure In Patients Treated Surgically For Goiters
Autorzy:
Buła, Grzegorz
Mucha, Ryszard
Paliga, Michał
Truchanowski, Witold
Gawrychowski, Jacek
Powiązania:
https://bibliotekanauki.pl/articles/1395678.pdf
Data publikacji:
2015-07-01
Wydawca:
Index Copernicus International
Tematy:
goiter
acute respiratory failure
Opis:
The aim of the study was to present a clinical picture, treatment and prognosis regarding patients who developed acute respiratory failure (ARF) while treated surgically for a goiter. Material and methods. A total of 3810 patients were treated for goiters between 2008 to 2013. Symptoms of postoperative ARF were recognized in 39 (1%) patients. Results. Symptoms of postoperative ARF were a postoperative hemorrhage in 31 (79.4%), lymphorrhagia in 1 (2.6%), bilateral paralysis of recurrent laryngeal nerves in 6 (15.4%) and acute circulatory – respiratory failure in 1 (2.6%). Postoperative hemorrhage appeared in 19 patients operated for nodular goiter, 4 with a retrosternal nodular goiter, 1x nontoxic recurrent retrosternal nodular goiter, 1x toxic recurrent retrosternal goiter nodular goiter, 2x Graves'goiter and 4x with malignant goiter. The cause of hemorrhage was parenchymal bleeding from the stumps and / or short neck muscles (29x), arterial bleeding (1x) and bleeding into the subcutaneous tissue (1x). Massive lymphorrhagia appeared as a result of damage to the thoracic duct after total thyroidectomy due to papillary thyroid carcinoma with cervical lymph node dissection on the left side. All patients who were diagnosed with bilateral paralysis of RLN, tracheostomy was performed. Of all 39 patients who underwent surgery two died – one in 6 days after surgery due to myocardial infarction, and another as a result of micropulmonary embolism and acute circulatory – respiratory failure in 18 hours after surgery. Conclusions. 1. The most frequent causes of acute respiratory failure in postoperative period are a hemorrhage from the operation site and bilateral paralysis of recurrent laryngeal nerves. 2. Acute postoperative respiratory failure is an indication for postoperative wound revision
Źródło:
Polish Journal of Surgery; 2015, 87, 7; 331-335
0032-373X
2299-2847
Pojawia się w:
Polish Journal of Surgery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Czy możliwa jest budowa teorii moralnej zawodności rynku?
Is it possible to build a moral theory of market failure?
Autorzy:
Rogowski, Robert
Powiązania:
https://bibliotekanauki.pl/articles/653177.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
market
person
market failure
Opis:
Economics and ethics are practical sciences. The common research subject of both sciences is man. Economics is looking for an answer to the question of how to manage in business life. Ethics looks for the answer to the question of how to live. Because man is a person, his value brings consequences for all areas of human activity. This also applies to the market. The market is one of the foundations of economic life and is a great good for people and societies. The market is defined in different ways. It is worth comprehensively describing what the market is, emphasizing its personal character. In economics, attention is paid to market failure, understood mostly as the ineffectiveness of management (deviation from the model market, which is perfectly competitive). The negative impact of the market on society is also identified. Although moral aspects are increasingly taken into account in the concept of market failure, there is no general theory that attempts to capture market in moral aspects. Therefore, it is worth asking whether such a theory is possible. The construction of the moral theory of market failure can be a reference point to the analysis of market practices and institutional conditions from an ethical point of view.
Źródło:
Annales. Etyka w Życiu Gospodarczym; 2019, 22, 2; 25-39
1899-2226
2353-4869
Pojawia się w:
Annales. Etyka w Życiu Gospodarczym
Dostawca treści:
Biblioteka Nauki
Artykuł

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