• 제목/요약/키워드: Technical Reliability

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연구실 점검 및 진단 대가기준에 관한 연구 (A Study on Pricing Criteria of the Laboratory Safety Inspection and Diagnosis)

  • 이종호
    • 한국안전학회지
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    • 제33권5호
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    • pp.170-176
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    • 2018
  • Laboratory inspection and diagnosis is a means of investigating and assessing various hazards or the state of research equipment in a laboratory, then taking appropriate safety measures to prevent accidents and injury. In many cases, laboratory inspection and diagnosis carried out by agencies are performed in a perfunctory manner that only barely satisfies the legal requirements. The aim of the present study is to provide clearly established pricing criteria for laboratory inspection and diagnosis, so as to prevent recurrence of laboratory accidents and to establish a safe laboratory environment. In order to clarify previously unclear matters, such as the lower limit for bids submitted by laboratory inspection and diagnosis agencies, technical manpower requirements, and number of laboratories inspected and diagnosed per day, a questionnaire survey was administered to agency personnel. First, when asked what the lower limit for bids submitted by agencies should be in order to improve reliability of inspection and diagnosis results and make up for the shortcomings of the lowest-bidder-wins system, 85.5% of respondents answered that the lower limit for bids should stand at no lower than 90% of the estimated price. The level of technical expertise among the technical personnel committed to laboratory inspection and diagnosis was shown to impact the reliability of results, and questionnaire results indicated a need to vary technical expertise levels depending on the degree of hazard, substances handled, and equipment used in a given laboratory. Level of technical expertise(67.1%) and number of personnel(52.6%) were shown to have a greater impact on reliability of diagnosis than on reliability of inspection. According to the results, it is determined that three persons(specialist, advanced and intermediate) should be committed to inspections, while four persons(professional, specialist, advanced and intermediate) should be committed to diagnoses. The respondents indicated a larger number of laboratories could be inspected than diagnosed per day. This can be attributed to differences in the amount of work each task involves, and the time each task takes. Assuming a six-hour work day not counting transportation, paperwork and rest, it is thought that inspection of up to 36 laboratories will be possible if each laboratory is assigned no more than 10 minutes(34.7%), while up to 24 laboratories could be inspected and diagnosed if each laboratory is assigned 15 to 20 minutes(35.1%).

The Validity and Reliability of the Second Korean Working Conditions Survey

  • Kim, Young Sun;Rhee, Kyung Yong;Oh, Min Jung;Park, Jungsun
    • Safety and Health at Work
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    • 제4권2호
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    • pp.111-116
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    • 2013
  • Background: The aim of this study was to evaluate the quality of the Second Korean Working Conditions Survey (KWCS), focusing on its validity and reliability. Methods: The external validity was evaluated by the assessment of sampling procedures and the response rate, in order to investigate the representativeness of the sample. The content validity was evaluated by the assessment of the development of the questionnaire, and the consistency of questions for the selected construct. The test-retest method was used to evaluate the reliability by means of a phone call survey of 30% of the respondents, who were randomly selected. The respondents' satisfaction regarding the survey procedures and interview time were analyzed to evaluate the quality of survey data. Results: The external validity was assured by an acceptable sampling procedure, rigid multi-stage stratified cluster random sampling. The content validity was also guaranteed by a reasonable procedure for the development of the questionnaire with a pretest. The internal consistency of the questions for work autonomy was maintained, with 0.738 of Cronbach's alpha. The response rate of 36% was lower than that of the European Working Conditions Survey (EWCS), with a contact rate of 66%, compared to 76% for the EWCS. The matching rates of the five retested questions were more than 98% reliable. Conclusion: The quality of the second KWCS was assured by the high external and content validity and reliability. The rigid sampling procedure and development of the questionnaire contributed to quality assurance. The high level of reliability may be guaranteed by the sophisticated field survey procedures and the development of a technical manual for interviewers. The technical strategies for a high response rate should be developed for future surveys.

야전데이터를 활용한 무기체계 신뢰성 평가: K계열 무기체계 사례 중심 (Reliability Evaluation of Weapon System using Field Data: Focusing on Case Study of K-series Weapon System)

  • 정일한;이학용;박영일
    • 품질경영학회지
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    • 제40권3호
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    • pp.278-285
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    • 2012
  • Purpose: Weapon systems have the long life cycle unlike the consumer product. Thus, the reliability of weapon system is improved during the life cycle through the steady technical change. In this paper, we deal with the method of evaluating the reliability of weapon system with the field failure data. Methods: Especially, we present how to gather the field failure data and evaluate the reliability through the case of K-series weapon system. To evaluate reliability, the reliability growth model is used and the result is discussed. Results: It is steadily improved the reliability of K-series weapon system deployed from 2000 to 2004. The frequency of the failures that affect the mission is largely reduced and MTBMF(mean time between mission failure) is also improved. Conclusion: We can guess the trend of the reliability of weapon system with the field data through this study. Furthermore, it can be used to improve the reliability and make maintenance policy.

Recent Progress in Advanced LC Mixture Development for TFT LCD

  • Lee, Seung-Eun;Song, Dong-Mee;Kim, Eun-Young;Jacob, Thomas;Czanta, Markus;Manabe, Atsutake;Tarumi, Kazuaki;Wittek, Michael;Hirschmann, Harald;Rieger, Bernhard
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.159-162
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    • 2006
  • We reviewed our recent advances in LC mixture development identifying the new classes of materials to yield LC mixtures with faster switching times and better reliability

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Challenges for large size TV manufacturing;Process and Test Equipment

  • Kang, In-Doo;Brunner, Mathias;Tanaka, Tak;Sun, Sheng;Li, Julia
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.1673-1675
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    • 2006
  • As the manufacturing capacity needs for large size LCD TV shifts very fast into next generation, processing and test equipment makers face more difficult challenges in accommodating productivity, reliability and lead time of panel makers as well as the prerequisite of high process quality. In this paper, AKT will discuss its new innovative productivity solutions in PECVD (Plasma Enhanced Chemical Vapor Deposition), as the key thin film process system, and EBT (Electron Beam Test), as the key array test system, for the huge glass size with surface dimension larger than 2 meter by 2 meter.

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파라메트릭 모델링을 활용한 BIM기반 VE제안 관리 방안 (BIM-Based VE Proposal Management Using Parametric Modeling)

  • 김다인;최재현;이진강
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2023년도 봄 학술논문 발표대회
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    • pp.163-164
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    • 2023
  • The technical proposal bidding system emphasizes the evaluation of the construction company's technical capabilities, with the aim of improving the quality and cost-effectiveness of the construction. However, in the VE analysis and proposal process for technical proposal bidding, the ideas are often reused from similar past construction projects, and the application of new construction technologies/methods is often lacking. Therefore, this study proposes a methodology for managing VE proposal information by integrating it into a BIM model using parametric modeling. This research developed database based on the existing VE proposals and new construction technology/method information from the Korea Institute of Civil Engineering and Building Technology. And by using parametric modeling, the proposed method integrate the VE database with BIM model. The methodology proposed in this study is expected to improve the reliability and effectiveness of VE-related idea proposals in technical proposal bidding.

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저항형 초전도한류기의 신뢰도 모델을 적용한 배전계통 신뢰도 평가에 관한 연구 (A Study on the Evaluation of Distribution Reliability Considering Reliability Model for a Resistive-Type of Superconducting Fault Current Limiter)

  • 김성열;김욱원;김진오
    • 전기학회논문지
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    • 제60권3호
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    • pp.465-470
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    • 2011
  • Recently fault currents are increasing in a network. It is caused by increase in electric demand and high penetration of distributed generation with renewable energy sources. Moreover, distribution network has become more and more complex as mesh network to improve the distribution system reliability and increase the flexibility and agility of network operation. Accordingly, the fault current will exceed capacity of circuit breakers soon and all the various rational solutions to solve this problem are taken into account. Under these circumstances, superconducting fault current limiter(SFCL) is a new alternative in the viewpoint of technical and economic aspects. This study presents operation processes for a resistive-type of SFCL, and it proposes reliability model for the SFCL. When a SFCL is installed into a network, the contribution of decreased fault currents to failure for distribution equipments can be quantified. As a result, it is expected that a SFCL makes the reliability of adjacent equipments on existing network improve and these changes are analyzed. We propose a methodology to evaluate the reliability in the distribution network where a SFCL is installed considering a reliability model for resistive-type of SFCL and reliability changes for adjacent equipments which are proposed in this paper.

Manual Application of Adhesives

  • Hellmanns, Mark;Bohm, Stefan;Dilger, Klaus
    • 접착 및 계면
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    • 제7권4호
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    • pp.24-27
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    • 2006
  • International standards claim the best possible reliability in industrial manufacturing processes. This is also essential for the application with manual applicators. The application of adhesives with manual applicators is one of the most frequently used application techniques. The range of application reaches from the building of prototypes in the automobile industry over the use in single or small-batch manufacturing up to applications in crafts enterprises. Conventional manual applicators for adhesives and sealants don't fulfill the demands in international standards for the best possible reliability. Only the worker is able to control the quality and the quantity of the bond. A velocity-controlled manual applicator solves these restrictions. Special sensors and micro controllers calculate the flow-rate, the velocity and the location of the manual applicator. This leads to stable and repeatable application processes which are claimed in international standards. The location of the bond can be compared with the nominal value, so that it is possible to check the quality of the bond during application. Furthermore there is the potential to document the data of the manufacturing process.

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Reliability of column capacity design in shear

  • Thomos, George C.;Trezos, Constantin G.
    • Computers and Concrete
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    • 제10권5호
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    • pp.507-521
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    • 2012
  • The capacity design of shear forces is one of the special demands of EC8 by which the ductile behavior of structures is implemented. The aim of capacity design is the formation of plastic hinges without shear failure of the elements. This is achieved by deriving the design shear forces from equilibrium conditions, assuming that plastic hinges, with their possible over-strengths, have been formed in the adjacent joints of the elements. In this equilibrium situation, the parameters (dimensions, material properties, axial forces etc) are random variables. Therefore, the capacity design of shear forces is associated with a probability of non-compliance (probability of failure). In the present study the probability of non-compliance of the shear capacity design in columns is calculated by assuming the basic variables as random variables. Parameters affecting this probability are examined and a modification of the capacity design is proposed, in order to achieve uniformity of the safety level.

Reliability based calibration of the capacity design rule of reinforced concrete beam-column joints

  • Thomos, George C.;Trezos, Constantin G.
    • Computers and Concrete
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    • 제8권6호
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    • pp.631-645
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    • 2011
  • The capacity design rule for beam-column joints, as adopted by the EC8, forces the formation of the plastic hinges to be developed in beams rather than in columns. This is achieved by deriving the design moments of the columns of a joint from equilibrium conditions, assuming that plastic hinges with their possible overstrengths have been developed in the adjacent beams of the joint. In this equilibrium the parameters (dimensions, material properties, axial forces etc) are, in general, random variables. Hence, the capacity design is associated with a probability of non-compliance (probability of failure). In the present study the probability of non-compliance of the capacity design rule of joints is being calculated by assuming the basic variables as random variables. Parameters affecting this probability are examined and a modification of the capacity design rule for beam-column joints is proposed, in order to achieve uniformity of the safety level.