• Title/Summary/Keyword: reliability and safety

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A Quantitative Analysis on Human Errors in Shifting Hazardous Materials of Semiconductor Plants (반도체공장의 위험물 교체작업시 인적과오에 대한 정량적 분석)

  • 임현교
    • Journal of the Korean Society of Safety
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    • v.12 no.4
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    • pp.161-168
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    • 1997
  • Most plants producing semiconductors use a lot of chemicals, hazardous materials, and explosive gases. Though those materials are hazardous too much, some works still have to be done manually by human workers. However, according to a historical survey, more than half industrial accidents of those plants resulted from human errors or malfunctions. Thus, this research aimed 1) to diagnose shifting hazardous materials of semiconductor plants, 2) to estimate failure probability of human workers through human reliability analysis, and 3) to find out the tasks on which educational emphasis should be put. Through personal interview and visiting working spots, shifting tasks were analyzed, and modelled into a 24-step work, and after that, THERP and ETA was applied. During the shifting work, estimated human failure probability under the assumption of independency, 2.3004E-05, underestimated that probability 8. l008E-05 which could be calculated under the assumption of dependency. And this analysis showed that gas leakage from an old cylinder occupies 78.27% in the case of independent failures whereas gas leakage from a new cylinder occupies 75.06% in the case of dependent failures. So it was concluded that dependency assumption may gloss real situations. In addition, confirming gauge of regulators and closing valves turned out to be the most important tasks than purge tasks.

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The Development of PLS-II Storage-ring Girder Systems at PAL (방사광 가속기 PLS-II 저장링 거더 시스템 개발)

  • Kim, Seungnam;Lee, Chaesun;Lee, Honggi;Kim, Kwangwoo;Nam, Sanghun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.23 no.8
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    • pp.690-697
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    • 2013
  • The magnets and vacuum chambers, which are the main facilities of the Pohang light source are installed on the storage-ring girders. System safety and reliability should be taken into account for the precise operating of the main facilities, so vibration analysis is essential to do this. Static and seismic analyses were performed for the design of structure considering safety, and also frequency and response spectrum analyses were performed for the precise alignment. With these results, the effects of surrounding vibration were checked. This paper explains about the design and vibration analysis of girder systems.

Analysis of the Structural Robustness of Cabinet Structure Equipped with Military Vehicles (군용 차량 탑재 캐비닛 구조물의 구조건전성 분석)

  • Son, Dong-Hun;Kang, Kwang-Hee;Choi, Ji-Ho;Park, Do-Hoon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2014.10a
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    • pp.273-276
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    • 2014
  • The development of a vehicle-mounted radar to detect the location of enemy artillery is mainly mounted during operation to the mobility of the equipment and efficiency of utilization range. It is equipped with an electronic device responsible for the operation of the radar system. Electronic equipments is performed functionality imparted without an error-specific in spite of disturbances such as vibration / shock caused by vehicle movement. Therefore, vibration / shock resistance is held to prevent damaging from vibration / shock generated from the outside environment during operation. In addition, a standardized and specified cabinet structure equipped with electronic equipment is placed in shelter to ensure additional safety for vibration / shock. In this study, it is evaluated by analytical method with vibration / shock resistance of the cabinet structures for ensuring structural safety factor is applied to the aluminum. It is verified the reliability of the structure and structural dynamics to verify by calculated natural frequencies adding the weight of the cabinet structure and the structural displacement and stress results confirmed with vibration / shock caused by the vehicle movement.

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Nonlinear finite element analysis of reinforced concrete corbels at both deterministic and probabilistic levels

  • Strauss, Alfred;Mordini, Andrea;Bergmeister, Konrad
    • Computers and Concrete
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    • v.3 no.2_3
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    • pp.123-144
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    • 2006
  • Reinforced concrete corbels are structural elements widely used in practical engineering. The complex response of these elements is described in design codes in a simplified manner. These formulations are not sufficient to show the real behavior, which, however, is an essential prerequisite for the manufacturing of numerous elements. Therefore, a deterministic and probabilistic study has been performed, which is described in this contribution. Real complex structures have been modeled by means of the finite element method supported primarily by experimental works. The main objective of this study was the detection of uncertainties effects and safety margins not captured by traditional codes. This aim could be fulfilled by statistical considerations applied to the investigated structures. The probabilistic study is based on advanced Monte Carlo simulation techniques and sophisticated nonlinear finite element formulations.

A Study on Algorithm of Life Cycle Cost for Improving Reliability in Product Design (제품설계 신뢰성 제고를 위한 LCC의 알고리즘 연구)

  • Kim Dong-Kwan;Jung Soo-Il
    • Journal of the Korea Safety Management & Science
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    • v.7 no.5
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    • pp.155-174
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    • 2005
  • Parametric life-cycle cost(LCC) models have been integrated with traditional design tools, and used in prior work to demonstrate the rapid solution of holistic, analytical tradeoffs between detailed design variations. During early designs stages there may be competing concepts with dramatic differences. Additionally, detailed information is scarce, and decisions must be models. for a diverse range of concepts, and the lack of detailed information make the integration make the integration of traditional LCC models impractical. This paper explores an approximate method for providing preliminary life-cycle cost. Learning algorithms trained using the known characteristics of existing products be approximated quickly during conceptual design without the overhead of defining new models. Artificial neural networks are trained to generalize on product attributes and life cycle cost date from pre-existing LCC studies. The Product attribute data to quickly obtain and LCC for a new and then an application is provided. In additions, the statistical method, called regression analysis, is suggested to predict the LCC. Tests have shown it is possible to predict the life cycle cost, and the comparison results between a learning LCC model and a regression analysis is also shown

Development of an Inspection Manual for the Safety and Maintenance of Non-building Structures (공작물 안전 및 유지관리를 위한 안전점검 매뉴얼 개발 연구)

  • Kim, Dong-Gyu;Shin, Dong-Hyeon;Choi, Insub;Kang, Jaedo;Lee, Deuck-Hang;Shin, Jiuk
    • Journal of Korean Association for Spatial Structures
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    • v.24 no.3
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    • pp.95-107
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    • 2024
  • In South Korea, over 400,000 Non-building Structures are inadequately managed and exposed to potential risks due to insufficient inspection systems, leading to an increase in accidents and significant losses of life and property. Therefore, it is crucial for users to conduct proactive self-inspections to identify and mitigate potential hazards. This study reclassified Non-building Structures into four main categories by analyzing their structural characteristics and associated risks through statistical analysis. Among these, retaining walls, which account for the largest proportion, were systematically analyzed to identify common damage patterns. Based on this analysis, self-inspection checklists were developed for both non-experts and experts. The proposed process involves an initial visual inspection using a simple non-expert checklist, followed by a more detailed expert-level inspection if any anomalies are detected. The reliability of this process was validated through approximately 120 validation processes.

Development and Case of Manipulator Robot for Live-Working on Distribution Lines (배전선로 무정전 활선작업용 Manipulator 개발현황 및 사례)

  • Kim, Jae-Hoon;Kim, Seung-Ho;Kim, Chang-Hoi;Lee, Heung-Ho;Han, Sang-Ok
    • Proceedings of the KIEE Conference
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    • 2005.05b
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    • pp.45-50
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    • 2005
  • Nowadays, economical and social environments are changing to the type of an advanced country for development of techniques in power industry. So most of workers are recently avoiding the 3D works and asking for safety of working environment, etc. in highly dangerous parts such as hot line working on distribution lines, especially. Therefore, most advanced countries are using the support-arm or robotic systems on distribution line works for securing the construction reliability, economical feasibility and protection of linemen from the electric shock and so forth. In special Japanese electric power companies are using the robotic system named manipulator. In Korea, a support-arm has been developed for safety and facility in live working on distribution lines but not widely supplied. In this paper we will introduce development cases of support arm and manipulator robot for live working on distribution lines.

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A Study on the X-Band Active Radar Reflector for safety at the Sea (해상 안전을 위한 X밴드 능동형 레이더 반사기에 관한 연구)

  • 정종혁;김남호;양규식
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.3 no.4
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    • pp.849-858
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    • 1999
  • There are several improved designs of passive radar reflector available, but their performance is ultimately limited by the cross-section area and this is governed by the size of the buoy and the acceptable windage. Therefore it is needed to investigate the low-cost, low power, a active device that can be improve the reliability of response. Active Radar Reflector(AAR) consists of a microwave amplifier with separate receive and transmit antennas. It is a device which automatically transmits a signal in response to an interrogating signal received. It was intended to improve the consistency of the radar return from the buoy and the small craft, particularly in poor sea conditions. And it directly improves safety of navigation at sea.

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The Priority of Internal Control Factors for Information Systems based on Individual Characteristics (개인 특성에 따른 정보시스템 내부통제요소 중요도에 관한 연구)

  • 박종은;이우형;이명호
    • Korean Management Science Review
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    • v.21 no.1
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    • pp.57-76
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    • 2004
  • The development of informational technology has lead to a sharp change in not only the existing way of operations and management, but the way of human life or thinking as well. Those shifts of the paradigm in information technology have also affected Individuals to the organizational structure. A series of unexpected problems was, however, accompanied by the advance in informational technology, which had broaden its own area of application. Those problems include the losses of property or data the malfunction of systems and their wastefulness would result in, continuous increases in computer crimes, reliability and efficiency of the functional process with the development of information systems, such as the processing problems of inaccurate data, economical issues, and subjects related to safety, as interruptions of privacy, which would result from lots of one's exposure to the drains of personal information. Accordingly, Auditors' roles of information systems, for now, is more important than anything else in that they are responsible for the objective assessment of relevance and effectiveness of internal control systems under the environment of information systems. The objective of the study is, so as to obtain safety of information systems: First, to provide data to line-design internal control systems after finding internal control factors to prevent and eliminate the risks of information systems. Second, to evaluate the priorities of internal control factors with their effective management being considered as the key to settle the problems of risks of information systems. Third, to discriminate what factors affect In evaluating the relative degrees of Importance of internal control factors.

The Design of Fault Tolerant Dual System and Real Time Fault Detection for Countdown Time Generating System

  • Kim, Jeong-Seok;Han, Yoo-Soo
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.10
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    • pp.125-133
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    • 2016
  • In this paper, we propose a real-time fault monitoring and dual system design of the countdown time-generating system, which is the main component of the mission control system. The countdown time-generating system produces a countdown signal that is distributed to mission control system devices. The stability of the countdown signal is essential for the main launch-related devices because they perform reserved functions based on the countdown time information received from the countdown time-generating system. Therefore, a reliable and fault-tolerant design is required for the countdown time-generating system. To ensure system reliability, component devices should be redundant and faults should be monitored in real time to manage the device changeover from Active mode to Standby mode upon fault detection. In addition, designing different methods for mode changeover based on fault classification is necessary for appropriate changeover. This study presents a real-time fault monitoring and changeover system, which is based on the dual system design of countdown time-generating devices, as well as experiment on real-time fault monitoring and changeover based on fault inputs.