• 한국안전학회지
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• 제29권4호
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• pp.140-146
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• 2014

This paper presents a case study to develop e-learning contents of agricultural safety based on the assessment of risks of 4 selected crops and stock farming: rice, potatoes, apples, tomatoes and stock raising. The aged farmers, who are main workforce of current Korean agriculture and relatively more vulnerable to various risks of agricultural work compared to younger workers, were considered as the main users of the contents in developing them. The safety guidelines were presented as simple as possible and the interfaces were designed to be simple and easy to use so that the older users can use it without much difficulty. In making the scenarios of the contents, risk assessments were carried out for each crop and stock farming with the focus being on occupational diseases rather than accidental injuries. To make the contents more attractive to the farmers, the functions requiring active responses from the users, such as answering simple questions, were included in the contents. Usability evaluation by experts of ergonomics and agricultural tasks were carried out in modifying the draft version, whereas formal usability test was not included in the case study. Though there are some limitations in the developed contents in the aspects of evaluation of usability and effectiveness, this case study shows the structured procedure of developing e-learning safety contents based on the risk assessments on agricultural tasks. The developed e-learning contents are expected to be used practically and easily in educating and training older farmers about safety and health of agricultural tasks.

• 대한안전경영과학회지
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• 제17권4호
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• pp.397-401
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• 2015

In this study, analysed the characteristics of power drop and surface damage in solar cell through high temperature and humidity test in the 3 case of EVA(ethylene vinyl acetate) and 2 case ribbon thickness. The solar cells were tested during the 500hr in $85^{\circ}C$ temperature and 85% relative humidity conditions, that excerpted standard of PV Module(KS C IEC-61215). Through the EL(Electroluminescence) shots, specimen's surface have partialy damaged. Before and after high humidity and high temperature test, ribbon thickness $200{\mu}m$ EVA1 case power drop rate was 8.463%, EVA2 case was 6.667%, EVA3 case was 6.373%. In the ribbon thickness $250{\mu}m$ EVA1 case power drop rate was 6.521%, EVA2 case was 8.517%, EVA3 case was 6.019%. EVA3 case was the lowest power and FF(fill factor) drop rate at the 2 case of ribbon thickness, because EVA3 is laerger than EVA1 and EVA2 in thickness, elongation and tensile strength.

• 한국안전학회지
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• 제35권3호
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• pp.6-15
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• 2020

This study examined the structural behaviors and ultimate loads of assembled system scaffolds by load tests. Considering the number of bay and bracing installation, four specimens were tested. The bays were divided into 1 bay and 2 bays, with and without the bracing member installed. Failure modes and horizontal displacements show that the whole column buckled without showing no point of inflection in the column, regardless of whether or not braces were installed. Thus, the current design method of selecting the vertical spacing between the horizontal members of the system scaffold as the effective buckling length underestimates the effective buckling length. In case of 1 bay specimens, the ultimate loads between specimens with and with bracing members are similar. However, in case of 2 bay specimens, the specimen with bracing members shows the increased ultimate load of 36% compared with that without bracing members. In addition, as the number of bays in the system scaffold increases, the ultimate load of the unit vertical column increases in case of the specimen with bracing installation. However, in the specimen without bracing members, the ultimate load of the unit column reduces with the increment of the number of bays due to the torsional buckling. Therefore, it is essential to install bracing members to increase the whole strength of system scaffolds and the ultimate load of the unit column.

• 한국도시철도학회논문집
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• 제6권4호
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• pp.279-286
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• 2018

최근 열차운행의 안전을 실시간으로 감시하고 통제를 통해 사고 및 위험을 예방하는 안전관제 플랫폼의 연구가 진행 중에 있다. 초기 설계에서 기존 분산된 안전 데이터의 통합에 따른 대용량 데이터의 실시간 처리를 위하여 분산 네트워크를 지원하는 DDS통신 방식을 채택하였으나, 안전관제 플랫폼 내부의 서버와 콘솔 간 통신은 기존의 TCP소켓통신을 그대로 적용하였다. TCP소켓통신의 경우 1대1 통신으로 안전관제 테스트베드의 소규모 시스템을 위한 데이터 처리는 가능하지만, 추후 전국으로 확대되면 방대한 데이터로 인해 통신 트래픽이 발생하는 경우 대처가 어렵게 된다. 본 논문에서는 안전관제 플랫폼의 서버와 콘솔 간 인터페이스 방식을 분산네트워크를 지원하는 DDS통신으로 제안하였으며, TCP소켓방식과 DDS방식의 데모를 구현하고 처리량 및 속도 비교 분석을 수행하였다. 그 결과, DDS통신을 적용하는 경우 향후 변경될 수 있는 시스템에 대비하여 확장성과 유연성이 개선된다는 사실을 도출하였다.

• 해양환경안전학회지
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• 제28권7호
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• pp.1169-1178
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• 2022

이 연구의 목적은 해양안전을 위해 해양수산부와 KCG 등에 분산되어 있는 해양안전 집행업무를 효율적으로 운영하는 방안을 살펴보는 것이다. 일반적으로 해양사고는 세월호 사고, 서해훼리호 사고, 태안 허베이 스피리트 오염사고 등에서 알 수 있듯이 인명, 재산, 해양환경 등에 막대한 피해는 물론 재난으로 확대되는 경향이 있어 사고를 예방하는 근본적인 대책이 필요하다. 그런데 우리나라는 대형사고가 발생하면 단편적인 땜질식 처방만 해 왔으며, 세월호 사고 이후에도 관계자 처벌을 위한 후속조치에만 치중하고, 주요 해양선진국에서는 당연시 되고 있는 '해양안전 집행업무 일원화' 같은 근본적인 대책은 거론조차 제대로 되지 않고 있다. 이에 크고 작은 후진성 사고는 끊이지 않고 있으며, 선박의 대형화·고속화·노후화, 선원의 자질저하, 선박통항량의 증가, 해양레저의 발달, 해양안전업무의 이원화로 인한 비효율성 등으로 대형 해양사고, 후진성 사고의 개연성은 더욱 높아지고 있는 것이다. 따라서 해양안전 관련 선행연구 검토, 주요 해양선진국의 사례 및 VTS의 일원화 사례 등을 토대로 해양안전과 직결되는 내항선 안전관리·PSC·항로표지관리 등의 해양안전 집행업무의 효율적인 운영방안을 제시한다.

• 한국산업융합학회 논문집
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• 제26권2_1호
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• pp.239-248
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• 2023

In this paper, we conduct a study on the design that can secure the safety of the EPLA system by performing safety activities based on the ISO 26262 standard for vehicle functional safety. In the case of a company developing a detailed system, it is responsible for verification through hardware design and safety analysis in the overall flow of safety activities, and safety analysis according to the ASIL safety level must be properly performed. At this time, there are cases where the safety goal quantitative metric value suggested by the ISO 26262 standard cannot be satisfied only by the hardware design of the basic function, so it is necessary to design and install the safety mechanism. Based on ISO 26262 safety activities, it is possible to derive an effective design plan through hardware safety analysis.

• 산업경영시스템학회지
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• 제41권1호
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• pp.94-101
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• 2018

With the development of industrial technology and science, production and manufacturing facilities have been enhanced and improved, and the importance of the safety of workers has also been regulated and limited by various safety management methods. As a way to secure the safety of the workers from the production facility, the fail-safe and fool-proof methods are now being applied. Any possible insecure behavior and unsafe conditions can be removed by adopting the standards and specifications that are now secure the safety of workers and equipment. This research analyzes EN ISO 13849-1 international and European standards during CE certification. In order to secure acceptable reduced risks, the risk assessment process of ISO 12100 and the processes for reducing its risk are applied. In the current ISO 13849-1 standard, the criteria for the required performance level PLr (Required Performance Level) for the applicable risk and safety functions through the risk assessment are subjective and not subdivided. Therefore, the evaluation criteria are likely to cause judge's judgement error due to qualitative judgement. This research focuses on evaluation and acceptable performance level setting for the safety circuit of the equipment. We propose an objective and specific evaluation criteria to secure safety, and the proposed evaluation criteria are applied to the case study of the safety circuit for the equipment. In order to secure the safety of the entire safety circuit, the improvement of the MTTFd and DC level related to the SRP/CS (Safety-Related Parts of Control Systems)' lifetime is required for the future research.

• 설비공학논문집
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• 제30권1호
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• pp.17-23
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• 2018

A fire simulation was performed to analyze the temperature and smoke exhaust performance of roof vents of the arcade traditional market by comparing a basic model (Case A) and an improvement model (Case B~Case E). Temperature analysis by heat showed a low temperature distribution because Case E discharged smoke in both directions of length compared to other cases. However, the effect of heat by life safety standards was satisfied. The smoke exhaust analysis by smoke showed the highest performance because Case C was exhausted to 1 m on both sides of length.

• 한국철도학회논문집
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• 제20권3호
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• pp.320-328
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• 2017

철도차량에 폭 넓게 적용되고 있는 축상고무스프링의 노화에 따른 탈선안전도 영향을 분석하고자 노화 축상고무스프링 시료를 대상으로 특성시험을 수행하였다. 그리고 축상고무스프링 노화가 탈선 안전에 미치는 영향을 분석하기 위하여 주행 동특성 해석을 수행하였다. 사용연수 17년이 지난 롤고무 축상스프링 시료를 대상으로 한 상하방향 특성시험결과, 고무 노화로 인하여 변위 복원기능이 저하되었고 스프링강성이 현저히 증가하였다. 그리고 EN14363규격 적용 twist궤도 주행 시를 모사한 주행동특성 해석결과, 정상 차량모델(Case1)에 비하여 노화 축상스프링 특성을 적용한 차량모델(Case2)의 탈선계수와 윤중감소가 증가하여 탈선안전도는 저하하였다. 특히 급격한 선형 변동이 발생하는 천이구간 주행 시 윤중감소로 인한 탈선안전도는 취약하게 나타났다.

• 한국안전학회지
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• 제5권2호
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• pp.6-16
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• 1990

In this paper, the natural convection in a square enclosure, partly heated from below, with two adiabatic vertical wall and one upper horigental wall is studied nomerically. In numerical study, SIMPLE(Semi-Implicit for Pressure Linked Equation) algorithems are applied for the integration of momentum and energy equation. The grid size used in this study is the coordinates of size (22$\times$22). As a result of numerical analysis, the initial fluid flow depends on the thermal diffusion, but, as time passes, the fluid flow depends on convection and buoyancy of the enclosure. In Case 1, the heating region was been in the central position of the bottom wall. In case 2, the heating region was in the left position of the bottom. In case of Case 1, the lapse time of sensing the temperature of 72$^{\circ}C$ is approximately 15 sec almost at the same time in the coordinates (6, 22), (11, 22). In case of Case 2, the lapse time in the coordinates (6, 22), (11, 22) was 27 sec, 25 sec repectively. Also in case of Case 1 or Case 2, the gradients of y-position of the two sensors are transposed each other.