• 제목/요약/키워드: Functional Failure

검색결과 488건 처리시간 0.034초

피해파급에 대한 고찰을 통한 전력 및 상수도 네트워크의 강건성 예측 (Robustness Estimation for Power and Water Supply Network : in the Context of Failure Propagation)

  • 이슬비;박문서;이현수
    • 한국건설관리학회논문집
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    • 제19권3호
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    • pp.33-42
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    • 2018
  • 손상된 라이프라인 시스템의 공공서비스 제공 지연 예측은 지진 대응 체계 마련의 첫 단계이다. 그러나 라이프라인 시스템의 서비스제공가능도는 개별 구조물의 물리적 손상뿐만 아니라 인접한 구조물들로부터의 피해파급에 의해 변동될 수 있다. 이에 본 연구는 라이프라인 시스템의 기능 저하를 유발하는 공통원인피해와 연쇄피해의 발생 확률을 추론하기 위해 베이지안 모형을 작성하고 피해의 인과관계를 고려하여 최종 수요자 중심의 네트워크 강건성을 평가하는 방안을 제시하였다. 또한 완화대책에 따른 네트워크 강건성을 분석하기 위해 국내 대구경북지역의 전력 및 상수도 시스템을 대상으로 지진 규모에 따른 공공서비스의 공급 지연 확률을 예측하였다. 그 결과 사례 지역의 경우 안정적인 전력과 상수 수급을 위해 라이프라인 네트워크를 구성하는 노드들 간 피해파급을 저감하는 것이 효과적임을 확인하였다. 본 연구는 지진 피해 진단의 다양한 불확실성 간 인과관계를 도식화하였다는 데에 의의가 있으며, 지속 가능한 공공서비스 확보를 위한 지역단위 대책 수립을 지원할 수 있을 것으로 기대된다.

기능안전규격 ISO 26262의 효과적 구현을 위한 시스템공학 기반 요구사항 분석/검증 방법 (On a Method to Analyze and Verify the Functional Safety of ISO 26262 Based on Systems Engineering Framework)

  • 임관택;이재천
    • 대한안전경영과학회지
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    • 제15권3호
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    • pp.61-69
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    • 2013
  • According to ISO 26262 (the international standard on functional safety for automotive industry), the functional safety should be considered during the whole automotive systems life cycle from the design phase throughout the production phase. In order to satisfy the standard, the automotive and related industry needs to take appropriate actions while carrying out a variety of development activities. This paper presents an approach to coping with the standard. Analyzing the standard indicates that the safety issues of the automotive systems should be handled with a system's view whereas the conventional approach to solving the issues has been practiced with focus on the component's level. The aforementioned system's view implies that the functional safety shall be incorporated in the system design from both the system's life-cycle view and the hierarchical view for the structure. In light of this, the systems engineering framework can be quite appropriate in the functional safety development and thus has been taken in this paper as a problem solving approach. Of various design issues, the analysis and verification of the safety requirements for functional safety is a key study subject of the paper. Note, in particular, that the conventional FMEA (failure mode effects analysis) and FTA (fault tree analysis) methods seem to be partly relying on the insufficient experience and knowledge of the engineers. To improve this, a systematic method is studied here and the result is applied in the design of an ABS braking system as a case study.

AUTOSAR 소프트웨어 기능안전 메커니즘 설계 사례연구: Shift-by-Wire 시스템 (Case Study on AUTOSAR Software Functional Safety Mechanism Design: Shift-by-Wire System)

  • 금대현;권수현;이재성;이성훈
    • 대한임베디드공학회논문지
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    • 제16권6호
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    • pp.267-276
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    • 2021
  • The automotive industry and academic research have been continuously conducting research on standardization such as AUTOSAR (AUTomotive Open System ARchitecture) and ISO26262 to solve problems such as safety and efficiency caused by the complexity of electric/electronic architecture of automotive. AUTOSAR is an automotive standard software platform that has a layered structure independent of MCU (Micro Controller Unit) hardware, and improves product reliability through software modularity and reusability. And, ISO26262, an international standard for automotive functional safety and suggests a method to minimize errors in automotive ECU (Electronic Control Unit)s by defining the development process and results for the entire life cycle of automotive electrical/electronic systems. These design methods are variously applied in representative automotive safety-critical systems. However, since the functional and safety requirements are different according to the characteristics of the safety-critical system, it is essential to research the AUTOSAR functional safety design method specialized for each application domain. In this paper, a software functional safety mechanism design method using AUTOSAR is proposed, and a new failure management framework is proposed to ensure the high reliability of the product. The AUTOSAR functional safety mechanism consists of memory partitioning protection, timing monitoring protection, and end-to-end protection. The fault management framework is composed of several safety SWCs to maintain the minimum function and performance even if a fault occurs during the operation of a safety-critical system. Finally, the proposed method is applied to the Shift-by-Wire system design to prove the validity of the proposed method.

Integrated Quantitative Phosphoproteomics and Cell-Based Functional Screening Reveals Specific Pathological Cardiac Hypertrophy-Related Phosphorylation Sites

  • Kwon, Hye Kyeong;Choi, Hyunwoo;Park, Sung-Gyoo;Park, Woo Jin;Kim, Do Han;Park, Zee-Yong
    • Molecules and Cells
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    • 제44권7호
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    • pp.500-516
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    • 2021
  • Cardiac hypertrophic signaling cascades resulting in heart failure diseases are mediated by protein phosphorylation. Recent developments in mass spectrometry-based phosphoproteomics have led to the identification of thousands of differentially phosphorylated proteins and their phosphorylation sites. However, functional studies of these differentially phosphorylated proteins have not been conducted in a large-scale or high-throughput manner due to a lack of methods capable of revealing the functional relevance of each phosphorylation site. In this study, an integrated approach combining quantitative phosphoproteomics and cell-based functional screening using phosphorylation competition peptides was developed. A pathological cardiac hypertrophy model, junctate-1 transgenic mice and control mice, were analyzed using label-free quantitative phosphoproteomics to identify differentially phosphorylated proteins and sites. A cell-based functional assay system measuring hypertrophic cell growth of neonatal rat ventricle cardiomyocytes (NRVMs) following phenylephrine treatment was applied, and changes in phosphorylation of individual differentially phosphorylated sites were induced by incorporation of phosphorylation competition peptides conjugated with cell-penetrating peptides. Cell-based functional screening against 18 selected phosphorylation sites identified three phosphorylation sites (Ser-98, Ser-179 of Ldb3, and Ser-1146 of palladin) displaying near-complete inhibition of cardiac hypertrophic growth of NRVMs. Changes in phosphorylation levels of Ser-98 and Ser-179 in Ldb3 were further confirmed in NRVMs and other pathological/physiological hypertrophy models, including transverse aortic constriction and swimming models, using site-specific phospho-antibodies. Our integrated approach can be used to identify functionally important phosphorylation sites among differentially phosphorylated sites, and unlike conventional approaches, it is easily applicable for large-scale and/or high-throughput analyses.

$\cdot$하악 대구치 부위에 식립된 임플란트의 생존율에 대한 후향적 연구 (Survival analysis of dental implants in maxillary and mandibular molar regions; A 4$\sim$5 year report)

  • 장진화;류경호;정현주
    • Journal of Periodontal and Implant Science
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    • 제37권2호
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    • pp.165-180
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    • 2007
  • Dental Implants have been proved to be successful prosthetic modality in edentulous patients for 10 years. However, there are few reports on the survival of implant according to location in molar regions. The purpose of this study was to evaluate the $4{\sim}5$ years' cumulative survival rate and the cause of failure of dental implants in different locations for maxillary and mandibular molars. Among the implants placed in molar regions in Gwangju Mir Dental Hospital from Jan. 2001 to Jun. 2002, 473 implants from 166 patients(age range; $26{\sim}75$) were followed and evaluated retrospectively for the causes of failure. We included 417 implants in 126 periodontally compromised patients, 56 implants in 40 periodontal healthy patients, and 205 maxillary and 268 mandibular molar implants. Implant survival rates by various subject factors, surgical factors, fixture factors, and prosthetic factors at each location were compared using Chi-square test and Kaplan-Meier cumulative survival analysis was done for follow-up(FU) periods. The overall failure rate at 5 years was 1O.2%(subject level) and 5.5%(implant level). The overall survival rates of implants during the FU periods were 94.5% with 91.3% in maxillary first molar, 91.1% in maxillary second molar, 99.2% in mandibular first molar and 94,8% in mandibular second molar regions. The survival rates differed significantly between both jaws and among different implant locations(p<0.05), whereas the survival rates of functionally loaded implants were similar in different locations. The survival rates were not different according to gender, age, previous periodontal status, surgery stage, bone graft type, or the prosthetic type. The overall survival rate was low in dental implant of too wide diameter(${\geq}5.75$ mm) and the survival rate was significantly lower for wider implant diameter(p

Toxicological Profiles of Poisonous, Edible, and Medicinal Mushrooms

  • Jo, Woo-Sik;Hossain, Md. Akil;Park, Seung-Chun
    • Mycobiology
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    • 제42권3호
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    • pp.215-220
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    • 2014
  • Mushrooms are a recognized component of the human diet, with versatile medicinal properties. Some mushrooms are popular worldwide for their nutritional and therapeutic properties. However, some species are dangerous because they cause toxicity. There are many reports explaining the medicinal and/or toxic effects of these fungal species. Cases of serious human poisoning generally caused by the improper identification of toxic mushroom species are reported every year. Different substances responsible for the fatal signs and symptoms of mushroom toxicity have been identified from various poisonous mushrooms. Toxicity studies of mushroom species have demonstrated that mushroom poisoning can cause adverse effects such as liver failure, bradycardia, chest pain, seizures, gastroenteritis, intestinal fibrosis, renal failure, erythromelalgia, and rhabdomyolysis. Correct categorization and better understanding are essential for the safe and healthy consumption of mushrooms as functional foods as well as for their medicinal use.

FMEA에 의한 기계 부품의 신뢰도 분석

  • 이상진;고장주;강창학;이치우
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2004년도 추계학술대회 논문집
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    • pp.87-91
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    • 2004
  • This paper dealt with FMEA, Which is a method of the analysis to secure safety and confidence coming up to customer's expectation in consideration of the environment of the corporation, the industrial environment, and the functional improvement. And by using FMEA, We showed the example analyzed the confidence of the reduction gear. It was proved by the result of the analysis that the rate of the breakdown which is usually regarded as the first important point to reform can't satisfy the selecting basis to improve. Also the result said that it is not right to depend on only the rate of the failure in making the list of the reform. Through the analysis of the breakdown, FMEA can present the important factors of the reform to improve the confidence of the system. In this study would show the important factors of the improvement in order to product the goods guaranteed confidence through the method of FMEA.

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대동맥궁 결손증의 완전교정 치험 1예 (Interrupted Aortic Arch(Type A) associated with PDA, VSD, Mitral Regurgitation and Single Coronary Artery)

  • 이재진
    • Journal of Chest Surgery
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    • 제21권3호
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    • pp.588-593
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    • 1988
  • We experienced a case of interrupted aortic arch[Type A] associated with PDA, VSD, mitral regurgitation and single coronary artery. The patient was 7 years old boy, who showed congestive heart failure[NYHA functional class III]. One stage total correction was performed under profound hypothermia with total circulatory arrest. Aortic continuity was established using PDA with anterior wall of main pulmonary artery flap. VSD was closed with Dacron patch and mitral regurgitation repaired by Reed`s annuloplasty method. The postoperative cardiac catheterization revealed no pressure gradient between ascending aorta and descending aorta, decreased pulmonary artery pressure and trivial residual shunt[Qp/Qs: 1.28]. The aortogram showed good continuity of the aorta without narrowing of the anastomotic site. During the period of 1 year follow up, heart failure symptoms were nearly subsided.

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공통원인고장을 고려한 안전제어시스템의 신뢰성 평가척도에 관한 고찰 : IEC 61508을 중심으로 (On Reliability Performance of Safety Instrumented Systems with Common Cause Failures in IEC 61508 Standard)

  • 서순근
    • 산업공학
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    • 제25권4호
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    • pp.405-415
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    • 2012
  • The reliability performance measures for low and high or continuous demand modes of operation of safety instrumented systems(SISs) are examined and compared by analyzing the official definitions in IEC 61508 standard. This paper also presents a status of common cause factor(CCF) models used in IEC 61508 and problems relating CCF modelling are discussed and ideas to solve these ones are suggested. An example with mixed M-out-of-N architecture is carried out to illustrate the proposed methods.

Anaysis of System Lifetime Subject to Two Classes of Random Shocks

  • Kunmin Yeo;Jun, Chi-Hyuck
    • International Journal of Reliability and Applications
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    • 제1권1호
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    • pp.49-64
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    • 2000
  • We consider a system whose inherent life follows an Erlang distribution, which is subject to two heterogeneous random shocks. Minor shocks arrive according to a renewal process and each causes the system to fail independently with a certain probability. A major shock whose interarrival times follow an Erlang distribution causes the system to fail with probability one. The Laplace transform of the distribution of the time to system failure is derived in a functional form of the Laplace transform of the interarrival time distribution of minor shocks. An algorithm is given for the computation of the moments of the time to system failure.

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