• 제목/요약/키워드: failure experience

검색결과 678건 처리시간 0.035초

불규칙 하중을 받는 Shell 구조물의 동적 신뢰성 해석에 관한 연구 (A Study on the Dynamic Reliability Analysis of the Shell Structure under Random Loads)

  • 배동명
    • 수산해양기술연구
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    • 제33권4호
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    • pp.334-345
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    • 1997
  • Reliability-based design approaches are needed for cylindrical shell structure whose design and operational experiences are few and which are subjected to external loads of random loads. In designing new type of structure, it is very difficult to evaluate the safety factors due to lack of previous design data and operational experience. To solve the above mentioned problem, much attention is being focussed on rational reliability based design approaches. This paper deals with weight-optional reliability-based design of cylindrical shell structure subjected to structural reliability constraints taking into account of the effect of local buckling and interactive behavior between local and global buckling. Present mentioned is compared with the exiting optional design method based only on safety factors. Numerical simulation reveals that the present method leads to lighter structure (4% reduction in weight compared to the existing optimal design) with the same reliability index. For larger structures with more number of structural members and possible failure modes, the present W0RBD procedure will be an efficient tool in designing cost-effective rationalized economic design.

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NHPP 극값 분포 소프트웨어 신뢰모형에 대한 학습효과 기법 비교 연구 (The Camparative study of NHPP Extreme Value Distribution Software Reliability Model from the Perspective of Learning Effects)

  • 김희철
    • 디지털산업정보학회논문지
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    • 제7권2호
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    • pp.1-8
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    • 2011
  • In this study, software products developed in the course of testing, software managers in the process of testing software test and test tools for effective learning effects perspective has been studied using the NHPP software. The finite failure non-homogeneous Poisson process models presented and the life distribution applied extreme distribution which used to find the minimum (or the maximum) of a number of samples of various distributions. Software error detection techniques known in advance, but influencing factors for considering the errors found automatically and learning factors, by prior experience, to find precisely the error factor setting up the testing manager are presented comparing the problem. As a result, the learning factor is greater than automatic error that is generally efficient model could be confirmed. This paper, a numerical example of applying using time between failures and parameter estimation using maximum likelihood estimation method, after the efficiency of the data through trend analysis model selection were efficient using the mean square error.

철강산업 전자상거래 활성화를 위한 영향 요인 분석 (A Study on factors for steel industry e-Commerce)

  • 조남재;한상호;금정원
    • 한국디지털정책학회:학술대회논문집
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    • 한국디지털정책학회 2007년도 춘계학술대회
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    • pp.297-304
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    • 2007
  • The purpose of this research is to investigate the current state of e-commerce for corporations in the steel industry and to analyze the factors that led failure in active use of e-commerce. Data from 51 companies are col looted. Factors that affect the e-commerce adoption and use of were analyzed. The influence of e-commerce utilization on corporate performance was also examined. It was found that several factors known to influence e-commerce use in the steel industry such as transact ion methods, preferences, and the level of information-orientation, did not actually have a significant impact. Rather items such as the maturity of e-commerce experience and perceptual compatibility between product characteristics and e-commerce turned out to have a significant influence on the utilization levels of e-commerce. The level of e-commerce utilization in system had a significant impact on each of the three performance dimensions : internal performance, external performance and financial performance.

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Site Quality Evaluation Prototype for Building Deck-plate Construction

  • Shim, Young-Bo;Cho, Dong-Hyun;Koo, Kyo-Jin
    • 한국건축시공학회지
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    • 제13권1호
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    • pp.90-100
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    • 2013
  • Deck-plates are widely used on construction sites, and have the advantage of enabling contractors to achieve a relatively uniform quality. But nevertheless, quality deviation in deck-plate construction can occur as the result of differences in site conditions and the experience of crew workers. In this study, the authors present a site quality evaluation prototype for building deck-plate construction. Through analyses of case studies and interviews with experts, standard quality check sheets and a quality management index were developed by estimating the importance of quality check items based on a Failure Mode and Effects Analysis (FMEA) method. The applicability and effectiveness of the prototype was evaluated through a case study and interviews with case participants. It was found that the prototype promoted an active quality management as a way of continuously improving quality management in deck-plate construction instead of passive quality inspection practice.

혈압 상승으로 인한 의식하 진정 요법의 실패 -증례보고- (Failure of Intravenous Sedation due to Significant Hypertension -A Case Report-)

  • 고세욱
    • 대한치과마취과학회지
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    • 제7권2호
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    • pp.126-130
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    • 2007
  • Sedation is often indicated for the relief of anxiety for outpatient oral surgery. In combination with local anesthesia, it is safe and effective method of treatment. However, it is not always effective in allowing the physician to complete the planned oral surgery procedure. On occasion, a procedure is left unfinished due to patient combativeness and discomfort and hypertension in spite of increase in sedative doses. Episodic increases in blood pressure were most commonly caused by light anesthesia or sedation and by the patient's experience of pain during treatment. Female patient was 42 years old. blood pressure is 150/90 mmHg. Extraction and implant surgery was done under IV sedation. During seadtion, her blood pressure was increased (200/100 mmHg). Surgery was stopped. She was done monitoring blood pressure. The blood pressure was decreased to 130/90 mmHg. Sedation was failed due to significant hypertension. Blood pressure is seldom increased during sedation but we should evaluate the patient's medical history and know guideline for hypertension crisis.

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시스템 안전성평가를 통한 효율적 요건 도출방안 연구 (A Study on the Safety Requirements Establishment through System Safety Processes)

  • 유승우;정진평;이백준
    • 항공우주시스템공학회지
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    • 제7권2호
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    • pp.29-34
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    • 2013
  • Safety requirements for aircraft and system functions include minimum performance constraints for both availability and integrity of the function. These safety requirements should be determined by conducting a safety assessment. The depths and contents of aircraft system safety assessment vary depending on factors such as the complexity of the system, how critical the system is to flight safety, what volume of experience is available on the type of system and the novelty and complexity of the technologies being used. Requirements that are defined to prevent failure conditions or to provide safety related functions should be uniquely identified and traceable through the levels of development. This will ensure visibility of the safety requirements at the software and electronic hardware design level. This paper has prepared to study on promoting the efficiency of establishing hierarchical safety requirements from aircraft level function to item level through system safety processes.

장애인 질적 정보격차의 영향요인에 관한 분석 (A Study on the Factors Affecting the Qualitative Digital Divide of People with Disabilitie)

  • 이선희
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2016년도 춘계 종합학술대회 논문집
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    • pp.479-480
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    • 2016
  • This study aimed to present the tasks to solve digital divide by understanding the actual condition of the digital divide of persons with disabilities in South Korea. Moreover, It is considered that the factors about qualitative digital divide. As a result, it was found that "Information Utilization Capacity" and "Information Utilization" tend to be higher among the young, more often male, higher education level, higher income people who had some information technology education and experience using telecommunication services. In Addition, all failure type affected the "age", "income", "information technology education" in common. Among them, influence of "age" and "information technology education" has become stronger than the other variables. Therefore, in order to solve the qualitative digital divide, it is required to focus as "age" and "information technology education".

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족관절의 인공관절 치환술 (Total Ankle Replacement Arthroplasty)

  • 성일훈;김현욱
    • 대한족부족관절학회지
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    • 제19권1호
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    • pp.1-6
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    • 2015
  • Total ankle replacement has been performed for treatment of end stage arthritis of the ankle, hopefully being an alternative to ankle arthrodesis. However, due to its high failure rates, earlier versions of ankle replacements were not regarded as successful procedures. The latest design has shown increasingly positive results. Total joint replacement of the ankle itself is still regarded as a demanding procedure and much more challenging than that of the hip and knee in many aspects. Several studies, however, have pointed out that it is becoming the viable, accepted alternative for arthrodesis with advanced implants, appropriate patient selection, and proper training experience of procedures. Compared with arthrodesis, it shows equal or better outcomes in pain relief, range of motion, and patient's satisfaction. We are attempting to review its biomechanical characteristics, implant design, indications, complications, clinical outcomes, and survival rate.

가사도우미에 의한 가사노동대체, 문화기술적 사례 연구 (A Qualitative Study on the Daily Help Substitution for the Household Work)

  • 김선미
    • 가족자원경영과 정책
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    • 제12권4호
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    • pp.15-33
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    • 2008
  • The purpose of this ethnography is to describe and analyze the employment and substitutional use of daily help for the household work. Ten housewives and one educator of daily help from Gwangju City were interviewed with an unstructured questionnaire. They experience many difficulties from this daily help employment and use, even though they gain some basic help from their service. The diversity of the routes to seek out this daily help means that there is no proper route. And the daily help's sudden quit causes many realistic and psychological problems. Frequent disagreement between the user's demand and help's implement comes from communication failure. Three different management patterns of daily help were issued ; 'conservative-dominant', 'rational-mandatory', 'powerless-dependent'.

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지중배전선로의 고장전류 크기 및 보호협조분석 (Ananalzing fault current and Protective coordination in the underground line)

  • 조남훈;하복남;이중호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 C
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    • pp.932-934
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    • 1998
  • Electric power distribution feeders are susceptible to faults caused by a variety of situations such as adverse weather conditions, tree contacts, equipment failure, accidents, etc. Distribution circuit faults result in a number of problems related to the reliability of service and customer power quality. In the past, the permanent interruption of customer service resulting from a blown fuse or a recloser lockout was the only factor which was used to determine service reliability. So we developed KODAS(Korea Distribution Automation System) with successful and had fieid-testing of Distribution Automation System in last three years at Kang-dong Branch Office. In performing the project, KEPRI has gained valuable experience, through dealing with many difficult problem. This paper is depicted about the circuit breaker coordination problems in the Underground for the Distribution Automation Feeder.

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