• 제목/요약/키워드: failure law

검색결과 325건 처리시간 0.029초

Upside-Down 욕조 곡선 형태의 고장 강도를 가지는 세분화 모형 (A Segmented Model with Upside-Down Bathtub Shaped Failure Intensity)

  • 박우재;김상부
    • 한국산업융합학회 논문집
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    • 제23권6_2호
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    • pp.1103-1110
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    • 2020
  • In this study, a segmented model with Upside-Down bathtub shaped failure intensity for a repairable system are proposed under the assumption that the occurrences of the failures of a repairable system follow the Non-Homogeneous Poisson Process. The proposed segmented model is the compound model of S-PLP and LIP (Segmented Power Law Process and Logistic Intensity Process), that fits the separate failure intensity functions on each segment of time interval. The maximum likelihood estimation is used for estimating the parameters of the S-PLP and LIP model. The case study of system A shows that the S-PLP and LIP model fits better than the other models when compared by AICc (Akaike Information Criterion corrected) and MSE (Mean Squared Error). And it also implies that the S-PLP and LIP model can be useful for explaining the failure intensities of similar systems.

Numerical study on mechanical and failure properties of sandstone based on the power-law distribution of pre-crack length

  • Shi, Hao;Song, Lei;Zhang, Houquan;Xue, Keke;Yuan, Guotao;Wang, Zhenshuo;Wang, Guozhu
    • Geomechanics and Engineering
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    • 제19권5호
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    • pp.421-434
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    • 2019
  • It is of great significance to study the mechanical properties and failure mechanism of the defected rock for geological engineering. The defected sandstone modeling with power-law distribution of pre-cracks was built in this paper by Particle Flow Code software. Then the mechanical properties of sandstone and the corresponding failure process were meticulously analyzed by changing the power-law index (PLI) and the number of pre-cracks (NPC). The results show that (1) With the increase of the PLI, the proportion of prefabricated long cracks gradually decreases. (2) When the NPC is the same, the uniaxial compressive strength (UCS) of sandstone increases with the PLI; while when the PLI is the same, the UCS decreases with the NPC. (3) The damage model of rock strength is established based on the Mori-Tanaka method, which can be used to better describe the strength evolution of damaged rock. (4) The failure mode of the specimen is closely related to the total length of the pre-crack. As the total length of the pre-crack increases, the failure intensity of the specimen gradually becomes weaker. In addition, for the specimens with the total pre-crack length between 0.2-0.55 m, significant lateral expansion occurred during their failure process. (5) For the specimens with smaller PLI in the pre-peak loading process, the concentration of the force field inside is more serious than that of the specimens with larger PLI.

간호법 제정에 대한 언론 동향 및 사회적 인식 분석 (Analysis of Media Trends and Social Perceptions on Nursing Law Legislation)

  • 이승희;주민호
    • 대한간호학회지
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    • 제53권4호
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    • pp.439-452
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    • 2023
  • Purpose: This study aimed to derive considerations for the enactment of nursing law by analyzing the trends and social perceptions of nursing law mentioned in major daily newspapers, cafes, and blogs. Methods: Main texts and comments that included nursing law as a keyword were collected from major daily news and online postings from January 2021 to August 2022. The data collected through web crawling were analyzed using a TousFlux program used for big data analysis. Results: During the period of study, the awareness level around nursing law enactment increased. In particular, public concern over nursing law enactment intensified due to the two political parties' policy pledges related to nursing law in January 2022 and the failure to introduce the nursing law to the national assembly judiciary committee in May 2022. Except in December 2021, public perception of nursing law enactment was generally favorable, with public opinion tilting more in favor of than against enactment. Conclusion: Public opinion should be considered when drafting and implementing the nursing law to make it easier for the people to understand what the law constitutes. In addition, it is necessary to pay attention to and continuously promote the relationship between medical care and nursing in the nursing law system of developed nations. Lastly, nursing law enactment can enhance nurses' retention intention and provide a sense of efficacy to medical services.

원치 않은 임신에 대한 아이의 부양비 (The Cost of Child Rearing for Wrongful Conception)

  • 봉영준
    • 의료법학
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    • 제12권2호
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    • pp.219-263
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    • 2011
  • "Wrongful conception" is a medical malpractice claim in which the plaintiff is the parent of a normal, healthy infant whose conception was unplanned and unwanted. Medical malpractice in wrongful conception can be the result of a failure to provide informed consent to a patient, failure to properly perform a surgery, or a physician's negligent handling of a patient's problems. In the concrete, wrongful conception cases fall into two categories; those involving pre-conception negligence, such as a failed contraceptive, sterilization or failing of the controlling of embryo-number on the IVF, and those involving post-conception negligence, such as a failure to diagnose a pregnancy or to perform an abortion procedure. In addition, Medical malpractice can be the result of a failure to provide informed consent to a patient. When bad results occur by medical malpractice or failure to provide informed consent to a patient, the range of recovery of damages is decided by a traditional civil liability law. However the calculation of damages for wrongful conception is not easy because the high value of life is included in that case. So many courts opinions in foreign country and Seoul High Court decision in 1996 allow damages for the pregnancy, birthing process and sterilization costs, but refuses to allow damages for child rearing expenses. As to the range of recovery of damages for wrongful conception, one approach says that to allow damages in a suit such as this would mean that the physician would have to pay for the fun, joy and affection which plaintiff will have in the rearing and educating of the plaintiff's baby. To allow such damages would be against the dignity of the baby based on article 10 of the Constitution. However another approach says that damages are recoverable for all expenses related to child birth as well as for child rearing costs. Because the damages that the parents should bear a burden to the tort damage done is not a baby itself but child rearing costs. In other words, although the baby is healthy or not, economic burden of the parents can not be disregard. And denial of compensation for costs of child rearing may invalidate the role of liability law, grant the physician with a exemption certificate of liability. As a result, the medical field of procreation can be easily isolated from a liability of reparation. Therefore, on the liability law like the other medical malpractice action, parents who became pregnant or gave a birth by physician, wrongfully performed sterilization operation, etc. should be compensated for all damages relevant to unplanned and unwanted conception or birth as well as costs of child rearing.

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Noninformative Priors for the Power Law Process

  • Kim, Dal-Ho;Kang, Sang-Gil;Lee, Woo-Dong
    • Journal of the Korean Statistical Society
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    • 제31권1호
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    • pp.17-31
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    • 2002
  • This paper considers noninformative priors for the power law process under failure truncation. Jeffreys'priors as well as reference priors are found when one or both parameters are of interest. These priors are compared in the light of how accurately the coverage probabilities of Bayesian credible intervals match the corresponding frequentist coverage probabilities. It is found that the reference priors have a definite edge over Jeffreys'prior in this respect.

Musa-Okumoto와 Power-law형 NHPP 소프트웨어 신뢰모형에 관한 통계적 공정관리 접근방법 비교연구 (The Assessing Comparative Study for Statistical Process Control of Software Reliability Model Based on Musa-Okumo and Power-law Type)

  • 김희철
    • 한국정보전자통신기술학회논문지
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    • 제8권6호
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    • pp.483-490
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    • 2015
  • 소프트웨어의 디버깅과정에서 오류 발생의 시간을 기반으로 하는 많은 소프트웨어 신뢰성 모델이 제안되어 왔다. 무한고장 모형과 비동질적인 포아송 과정에 의존한 소프트웨어 신뢰성 모형을 이용하면 모수 추정이 가능하다. 소프트웨어를 시장에 인도하는 결정을 내리기 위해서는 조건부 고장률이 중요한 변수가 된다. 무한 고장 모형은 실제 상황에서 다양한 분야에 사용된다. 특성화 문제, 특이점의 감지, 선형 추정, 시스템의 안정성 연구, 수명을 테스트, 생존 분석, 데이터 압축 및 기타 여러 분야에서의 사용이 점점 많아지고 있다. 통계적 공정 관리 (SPC)는 소프트웨어 고장의 예측을 모니터링 함으로써 소프트웨어 신뢰성의 향상에 크게 기여 할 수 있다. 컨트롤 차트는 널리 소프트웨어 산업의 소프트웨어 공정 관리에 사용되는 도구이다. 본 논문에서 NHPP에 근원을 둔 로그 포아송 실행시간 모형, 즉,Musa-Okumo 모형과 파우어 로우(Power-law) 모형의 평균값 함수를 이용한 통계적 공정관리 차트를 이용한 제어 메커니즘을 제안하였다.

Fick's second law 를 이용한 수냉식 발전기 고정자 권선의 건전성 예지 (Health prognostics of stator Windings in Water-Cooled Generator using Fick's second law)

  • 윤병동;장범찬;김희수;배용채
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2014년도 추계학술대회 논문집
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    • pp.533-538
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    • 2014
  • Power generator is one of the most important component of electricity generation system to convert mechanical energy to electrical energy. I t designed robustly to maintain high system reliability during operation time. But unexpected failure of the power generator could happen and it cause huge amount of economic and social loss. To keep it from unexpected failure, health prognostics should be carried out In this research, We developed a health prognostic method of stator windings in power generator with statistical data analysis and degradation modeling against water absorption. We divided whole 42 windings into two groups, absorption suspected group and normal group. We built a degradation model of absorption suspected winding using Fick's second law to predict upcoming absorption data. Through the analysis of data of normal group, we could figure out the distribution of data of normal windings. After that, we can properly predict absorption data of normal windings. With data prediction of two groups, we derived upcoming Directional Mahalanobis Distance (DMD) of absorption suspected winding and time vs DMD curve. Finally we drew the probability distribution of Remaining Useful Life of absorption suspected windings.

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Bearing capacity at the pile tip embedded in rock depending on the shape factor and the flow

  • Ana S. Alencar;Ruben A. Galindo;Miguel A. Millan
    • Computers and Concrete
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    • 제31권5호
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    • pp.443-455
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    • 2023
  • This is a research analyses on the bearing capacity at a pile tip embedded in rock. The aim is to propose a shape coefficient for an analytical solution and to investigate the influence of the plastic flow law on the problem. For this purpose, the finite difference method is used to analyze the bearing capacity of various types and states of rock masses, assuming the Hoek & Brown failure criterion, by considering both plane strain and an axisymmetric model. Different geometrical configurations were adopted for this analysis. First, the axisymmetric numerical results were compared with those obtained from the plane strain analytical solution. Then the pile shape influence on the bearing capacity was studied. A shape factor is now proposed. Furthermore, an evaluation was done on the influence of the plastic flow law on the pile tip bearing capacity. Associative flow and non-associative flow with null dilatancy were considered, resulting in a proposed correlation. A total of 324 cases were simulated, performing a sensitivity analysis on the results and using the graphic output of vertical displacement and maximum principal stress to understand how the failure mechanism occurs in the numerical model.

가속수명시험 모델에 따른 평기어의 신뢰성 해석 (Reliability Analysis of the Spur Gear with Accelerated Life Testing Model)

  • 김철수;권여현;김주형;김정규
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 추계학술대회
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    • pp.136-141
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    • 2004
  • The gear in various mechanical components easily occurs at damages by the external torque. The main failure modes of the gear are surface pitting with the tooth surface and breakage with tooth root by caused fatigue. Therefore, the gear is very important role in the reliability research since it may cause fatal damage of entire system such as the gear box in automobile transmission. In this study, the failure mode of the gear was analyzed and accelerated durability analysis was employed for the life estimation of spur gears. In the case of assumed load spectrums, the reliability of spur gears was evaluated by inverse power law-Weibull accelerated life test model with cumulative damage exposure.

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