• 한국안전학회지
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• 제32권3호
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• pp.15-20
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• 2017

This study presented the strength of the materials and parts for smart distribution board fabrication, and developed a work operation process chart for smart distribution board fabrication. This work operation process chart for smart distribution board fabrication complied with SPS-KEMC regulations, and the applicable range and object are less than 1,000 V and 1,000 Hz for the AC distribution board and less than 1,500 V for the DC distribution board. The power supply is 3 phase 4 wires ($3{\Phi}$ 4W), divided into a single phase circuit and a 3 phase circuit. In addition, the circuit was configured so that the leakage current flowing through the distribution line of the load could be monitored in real time by using the sensor module installed at the rear end of the circuit breaker. Therefore, the administrator can easily find the risk factor of the load since engineer can check the leakage current of each distribution line. In addition, if a leakage current greater than standard value flows, it is possible to generate an alarm against a short circuit and cut off the leakage current. The work operation process chart for the smart distribution board fabrication consists of the following steps: raw and subsidiary materials, sheet metal work, tube making, welding, painting, busbar fabrication, assembly and wiring, product inspection, shipment, etc. Moreover, symbols, ${\Delta}$, ${\nabla}$, ${\bigcirc}$, ${\Rightarrow}$, etc. were used according to the type of work and work progress so that workers can easily understand the progress of the work.

• 한국산림과학회지
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• 제103권4호
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• pp.574-582
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• 2014

산림분야에서는 노동재해 예방을 위하여 임업 노동자의 자격과 선발기준, 기능인영림단의 구성요건, 안전대책 등에 관한 사항을 여러 법규와 지침 등에 규정하고 있다. 우리나라의 임업 교육훈련은 산림청의 교육원과 산림조합중앙회 소속의 3개 훈련원에서 담당하고 있다. 3개 훈련원에서는 공통과정과 특화과정으로 나누어 교육훈련을 실행하고 있으며, 안전교육은 각 교육과정별 커리큘럼 안에 포함하여 시행되고 있다. 본 연구에서는 임업분야 재해율 저감을 위하여 다음과 같은 제도적 개선방안을 제안하였다. (1) 적성검사 실시, 연령 제한 등 임업노동자의 자격 선발 기준 강화. (2) 기능인영림단 구성을 위한 필수인력의 교육 일수 및 자격 소지자 구성비율 상향 조정. (3) 산림경영기술자(기능2급)의 자격취득에 관한 규정 보완. (4) 보수교육(안전교육)을 통한 자격갱신 제도 도입. (5) 산림작업현장에서의 근로조건 개선 및 안전교육의 체계화. (6) 개인보호구 관련 규정 보완. (7) 개인보호구 착용 여부 수시 지도점검. (8) 안전의식 강화를 위한 현장 대응 보완.

• 대한안전경영과학회지
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• 제17권2호
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• pp.117-127
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• 2015

This study investigated the smoke blocking and control systems for the safety of residents evacuation and for the prevention of smoke spread through the central corridor in the event of central corridor type of intelligent building fire. We offered additional ways of utilizing smoke ventilators and intake ventilation equipment and utilized CFD-based fire simulation program(FDS Ver.5.5.3) in order to analyze the effect. As a result, many differences in the smoke block effect, depending on the application of smoke ventilator and location of installation, was found. In addition, the result was found that larger effect was showed not in the case of application of smoke ventilator in central corridor only but application in fire room. The reason is that the smoke leakage is blocked primarily as air is flowed in the fire room through open door by operation of intake smoke ventilator in the public corridor and secondarily, the smoke leakage to the public corridor could be blocked as fire and smoke were released to the opened smoke ventilator continuously. Especially, the effect was maximized through complex interactions by applying smoke ventilator and intake ventilation equipment in corridor together rather than applying smoke ventilator and intake ventilation equipment independently. The proposed measure through this study shall be considered from architectural plan as one of ways for blocking from smoke spread to the central corridor in the central corridor type of intelligent building. In addition, flaws on regulation shall be established and supplemented.

• Journal of Microbiology and Biotechnology
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• 제31권9호
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• pp.1311-1322
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• 2021

Microbially induced calcium carbonate precipitation (MICP) has recently become an intelligent and environmentally friendly method for repairing cracks in concrete. To improve on this ability of microbial materials concrete repair, we applied random mutagenesis and optimization of mineralization conditions to improve the quantity and crystal form of microbially precipitated calcium carbonate. Sporosarcina pasteurii ATCC 11859 was used as the starting strain to obtain the mutant with high urease activity by atmospheric and room temperature plasma (ARTP) mutagenesis. Next, we investigated the optimal biomineralization conditions and precipitation crystal form using Plackett-Burman experimental design and response surface methodology (RSM). Biomineralization with 0.73 mol/l calcium chloride, 45 g/l urea, reaction temperature of 45℃, and reaction time of 22 h, significantly increased the amount of precipitated calcium carbonate, which was deposited in the form of calcite crystals. Finally, the repair of concrete using the optimized biomineralization process was evaluated. A comparison of water absorption and adhesion of concrete specimens before and after repairs showed that concrete cracks and surface defects could be efficiently repaired. This study provides a new method to engineer biocementing material for concrete repair.

• 대한조선학회논문집
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• 제36권3호
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• pp.115-121
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• 1999

선박의 사고는 인명과 재산의 손실뿐만 아니라 사고 선박으로부터 유출되는 기름과 유해한 산적 화물에 의한 환경 오염을 초래하기 때문에 사고를 미연에 방지하는 것 뿐 만 아니라, 사고가 발생하였을 때 이에 신속히 대처함으로써 오명을 최소화하고 2차 사고의 위험을 줄이는 것이 매우 중요한 문제이다. 그러나 지금까지의 기술적 지원이 결여된 경험위주의 대처 방법으로는 사고선박에 대한 구난을 안전하고 신속하게 처리하기가 쉽지 않다. 본 연구에서는 체계적이고 과학적인 구난지원 도구를 개발하여 이를 사고 현장의 구난지원 작업에 투입하고자 한다. 이를 위하여 구난지원 체계를 구축하고, 프로토타입 시스템을 개발하여 사고선박에 대한 안전하고 신속한 구난지원 가능성을 검토하였다.

• KIEAE Journal
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• 제14권6호
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• pp.105-110
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• 2014

The basic factors determining the amount of energy used in hospital buildings are weather conditions and building factors. But the real energy consumer is central plant equipment such as boilers and chillers that produce thermal energy for heating and cooling. Inaccurate decision of the primary equipment's size can cause a high initial-cost, an excessive equipment space, a wasted energy by low operation-efficiency and shortening of the machine's life. In this reason, the decision of optimal size for central plant equipment is very important. There are several factors for the decision such as an operation factor, a factor (equipment factor), piping losses and a simultaneous usage factor applied in the sizing process except a basic cooling load. But there is no standard method for applying those factors. Usually, factors are applied individually by an experience or custom of each engineer. In this study, the authors emphasize the meaning and the problem of those factors, examine them by analyzing factors which were applied to actual practices, and propose the recommendation value of safety, load, operation factors and application methods.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.606-613
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• 2004

One of the major forces that causes landslide is the amount of underground water resulted from rainfall and shear strength. As a result of close study on the landslide area affected by typoon Rusa it is observed that many landslides took place at the interface of rock and soil. Based on this observation that shear strength at the interface played a great role in landslide of the hilly area, two shear strengths were measured on different places, one at the interface between rocks and soil and the other just on soil. The two values thus derived were compared and used to review the safety factor for the hilly areas already collapsed. Back analysis was also used to calculate the ground water table according to the different rock types at the time when degradation happened.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.565-570
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• 2007

The explosionproof apparatus is a devices that is enclosed in a case capable of withstanding an explosion of a specified gas or vapor that may occur within it and of preventing the ignition of a specified gas or vapor surrounding the enclosure by sparks, flashes, or explosion of the gas or vapor within, and that operates at such an external temperature that a surrounding flammable atmosphere will not be ignited thereby This kind of exeplosionfproof devices should be installed suitable for the characteristics of the space or process condition that should be protected to prevent explosion or fire. But, due to the lack of information and techniques on the explosionproof technology, some dangerous area is not properly protected from an explosion or it cost too much to implement the explosionproof devices. In this report, the basic guidelines and several case studies of explosionproof devices installation will be introduced to be of help to field safety engineer.

• 기술사
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• 제34권1호
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• pp.23-26
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• 2001

Seohae Grand Bridge is a part of the new West Coast Highway(353km) under construction, which connects Inchon and Mokpo. It is the longest bridge in Korea (7.31 km), and has 97 spans of 60m each precast segmental approach bridges, 2 main spans of 165m each free cantilever segmental bridge(500m), and 1 stay cable bridge of 990m In total length. During the seven year long construction period, many new construction technologies and methods were utilized for the first time in Korea, and gave invaluable opportunities to experience and master these in completing the project on time with safety and precision. I am proud of being a member of this project, and wish to express deep appreciations to those who participated in the project.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.472-477
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• 2004

A new earthquake design method performing iterative calculations with secant stiffness was developed. Since basically the proposed design method uses linear analysis, it is convenient and stable in numerical analysis. At the same time, the proposed design method can accurately estimate the inelastic strength and ductility demands of the structural members through iterative calculations. In the present study, the procedure of the proposed design method was established, and a computer program incorporating the proposed method was developed. The proposed method, as an integrated analysis and design method, can directly address the earthquake design strategy intended by the engineer, such as limited ductility of member and the concept of strong column - weak beam. Through iterative calculations on a structural model with member sizes preliminarily assumed, the strength and ductility demands of each member can be determined so as to satisfy the given design strategy. As the result, structural safety and economical design can be achieved.