• Nuclear Engineering and Technology
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• 제49권5호
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• pp.928-940
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• 2017

An experiment using the $Prim{\ddot{a}}rkreisl{\ddot{a}}ufe$ Versuchsanlage (PKL) was performed for the OECD/NEA PKL-3 Project as a counterpart to a previous test with the large-scale test facility (LSTF) on a cold leg smallbreak loss-of-coolant accident with an accident management (AM) measure in a pressurized water reactor. Concerning the AM measure, the rate of steam generator (SG) secondary-side depressurization was controlled to achieve a primary depressurization rate of 200 K/h as a common test condition; however, the onset timings of the SG depressurization were different from each other. In both tests, rapid recovery started in the core collapsed liquid level after loop seal clearing, which caused whole core quench. Some discrepancies appeared between the LSTF and PKL test results for the core collapsed liquid level, the cladding surface temperature, and the primary pressure. The RELAP5/MOD3.3 code predicted the overall trends of the major thermal-hydraulic responses observed in the LSTF test well, and indicated a remaining problem in the prediction of primary coolant distribution. Results of uncertainty analysis for the LSTF test clarified the influences of the combination of multiple uncertain parameters on peak cladding temperature within the defined uncertain ranges.

• 한국공간구조학회논문집
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• 제21권3호
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• pp.25-34
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• 2021

This study develops a new device system for measuring a slope of object with non-adhesive, non-contact and non-face-to-face, namely Inclinometer Slope Laser Measuring (ISLM), that is applicable in the field. This system includes cradle, laser, camera, and computer and the filming and is performed after laser projection at programmed intervals. After measuring the amount of displacement converted to numerical values, these values can then be transferred to the office using the selected data transmission method. The obtained results from the test carried out to verify the reliability of the ISLM system indicated that the ISLM system can measure with accurately level of 0.1mm/Pixel at 1m distance and when increasing the camera resolution, the precision might increase proportionally. Therefore, the proposed measure system may widely apply on-site for various constructions, especially, in the case of object with very high surface temperature where exhibits difficulty to directly measure the adjacent structures. However, due to the sensitive reaction to the illuminance, this method can be applied with caution at times of large changes in illuminance, such as at dawn and at dusk.

• 한국안전학회지
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• 제32권5호
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• pp.122-128
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• 2017

Korean government announced long-term railway safety investment plan for the safety improvement by 2020. But no research have been done about differential analysis on railroad safety investment and safety improvement. In this study, recent 10 year data on safety investments and accident data are analysed for the differential analysis. Three main safety investments are analysed on regard to accident rate and accident fatalities. Three safety measures include level crossing accident, platform fatalities, and track trespass fatalities. About 90% of railway accident fatalities are caused by these three kind of accidents. Differential analysis shows about 4 to 6 years delay after railroad safety investment and safety improvement. This result can be utilized for the decision making on safety measures and safety target. Which required long term approach.

• 해양환경안전학회지
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• 제25권6호
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• pp.708-716
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• 2019

세월호 사고 이후 내항선 분야의 해사안전관리를 강화하기 위하여 해사안전감독관 제도가 도입되었다. 이들은 선박에 대한 정기 및 수시 지도·감독 중 선박의 시설 분야에서 중대한 결함사항이 발견되면 시정이 완료될 때 까지 선박의 항행을 정지하는 행정처분을 하고 있다. 항행정지명령은 내항선박에 대하여 해사안전감독관이 행사하는 강장 강력한 규제행위의 일종이다. 선박의 안전과 해양환경보호를 위한 해사안전감독관에 의한 내항선박의 지도·감독의 중요성은 아무리 강조해도 지나치지 않을 것이다. 그러나 각 지방해양수산청의 선박에 대한 규제의 정도는 이를 집행하는 사람에 따라 다소의 개인차가 있을 수 있으며, 집행과정에서 개인의 고의 또는 과실이 발생할 수가 있다. 지방해양수산청에 의한 선박의 억류는 선박운항 상의 지체를 가져오기 쉽고, 용선계약의 정지에 의하여 선박의 소유자는 많은 경제적 손실을 입을 수 있다. 그럼에도 불구하고 해사안전법에서는 해사안전감독관에 의한 항행정지명령의 행정처분에 대하여 이의신청과 같은 불복절차를 규정하지 않고 있다. 따라서 이러한 문제점을 극복하기 위하여 지도·감독의 근거가 되는 해사안전법 상에 개인의 고의 또는 과실에 의한 부당한 항행정지 행정처분에 대하여 이의신청을 통한 권리의 구제가 가능하도록 제도를 개선해야 한다.

• 한국안전학회지
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• 제17권1호
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• pp.79-86
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• 2002

In the case of earthquake, it is necessary to install earthquake instruments and to measure the ground motions for stable gas supply and restoration in case of supply suspension. Because each point in the site of the gas facilities has different characteristics of ground motion, it is recommended to measure at the point where the ground motion is representative. In this paper, ground motion analysis and noise pattern analysis are carried out to select suitable point for the installation of earthquake instruments and to set of dynamic range of sensors.

• 대한인간공학회지
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• 제9권2호
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• pp.47-54
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• 1990

These are preisely the controlling foators that we must deal with and measure in order to get relatistic answers. We must stop making simplifying assumptions to suit our quqntitative models man deal with complex situations. To be relistic our models must include and measure all important tangible and intangible, quantitatively measureable, and qualitative factors. This is precisely what we do with the analytic hierarchy process (AHP). In this paper, the statistics of industrial accidents are classified with its causes, and safety organization in D heavy industry company be evaluated by Analytic hierarchy model. The influence weight of level of safety organization can be ordered supervisor (0.364), operator (3.10), top manager (0.232) and executive (o.164) by AHP.

• Nuclear Engineering and Technology
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• 제55권3호
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• pp.861-869
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• 2023

This article proposes a novel approach to measure the performance of Safety-Critical Systems (SCS). Such systems contain multiple processing nodes that communicate with each other is modeled by a Petri nets (PN). The paper uses the PN for the performance evaluation of SCS. A set of ordinary differential equations (ODEs) is derived from the Petri net model that represent the state of the system, and the solutions can be used to measure the system's performance. The proposed method can avoid the state space explosion problem and also introduces new metrics of performance, along with their measurement: deadlock, liveness, stability, boundedness, and steady state. The proposed technique is applied to Shutdown System (SDS) of Nuclear Power Plant (NPP). We obtained 99.887% accuracy of performance measurement, which proves the effectiveness of our approach.

• 정보처리학회 논문지
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• 제13권6호
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• pp.278-283
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• 2024

소프트웨어를 구현할 때 인간의 생명에 위협이 될 수 있는 부작용이 발생할 수 있습니다. 그러므로 소프트웨어가 안전에 미치는 영향을 측정하고 위협을 완화하고 예방하기 위한 대안을 만드는 것이 필요합니다. 위협 요소에 의한 영향도 측정을 위하여 소프트웨어 안전 진단을 수행하기 위한 구성요소가 필요하다. 본 논문은 소프트웨어의 위협 요인을 내부 요인과 외부 요인으로 분류하고 이러한 위협 요인의 영향을 정량적으로 시연하는 것을 목표로 합니다.

• 한국화재소방학회논문지
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• 제15권4호
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• pp.71-77
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• 2001

현재 국가기간망의 주요 핵심인프라시설로서 급격히 증가하고 있는 지하공동구의 화재발생에 따른 피해 및 그 영향이 심각함에 따라 국내외의 공동구 화재의 유형을 분석 후에 선진국의 공동구의 화재안전을 위한 성능기준을 국내의 성능과 비교하여 문제점을 발췌하였다. 발췌한 문제점에 나타난 핵심요소를 선진국과 비교하여 국내 공동구에 시급히 필요한 구비성능을 제시하되 국내의 공동구 관리운영 및 공동구에 수용되는 시설물의 설치기준에 적합한 방안을 연구하여 제시하였다.

• 한국안전학회지
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• 제30권1호
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• pp.119-126
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• 2015

The primary purpose of the general duty clause is to offer an extra measure of protection to employees in the workplace. Most standards implemented under OSHA are targeted at a specific hazard. The general duty clause, however allows inspectors to cite employers for exposing its employees to a recognized hazard that has not been specifically addressed in the regulations. Congress intended the general duty clause to be a limited means of advancing the purposes of the OSHAct. But OSHA has not always regarded the general duty clause as the limited means for protecting the safety and health of employees that Congress intented. OSHA attempted to expand the scope of the general duty clause, at times improperly, to make it a more flexible enforcement tool. OSHA's interpretation of each of the restrictions on the scope of the clause has changed over the years. In recent years the general duty clause has been utilized as a sometimes controversial mechanism for enforcement of safety guidelines that have not yet been specifically addressed by statute or regulation. The most notable example of this was application of the general duty clause to ergonomic hazards.