• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2004년도 춘계학술대회 논문집
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• pp.335-340
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• 2004

To analyze risk factors of temporary power installations, the investigation was carried out for power receiving system and pack and panel boards at construction sites. The subject was variable such as an airport, an apartment, a municipal playground. There are many risk factors caused by inadequate working environments and the deterioration of temporary power installations using equipment with minimum safety devices at construction sites. There, it is intended to present problems and preventive measures against electrical shock accidents, through analyzing risk factors of real field condition and investigating temporary power installations all over the country.

• 대한치과기공학회지
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• 제38권3호
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• pp.165-173
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• 2016

Purpose: This study was conducted to examine the color stability of temporary prosthetic materials for dental CAD-CAM. Method: 2 kinds of existing acrylic resin temporary filling materials and 2 kinds of polymer prosthetic materials for dental CAD-CAM were used for testing, and five specimens respectively were absorbed in soy sauce, red pepper paste, and coffee. A Chroma Meter was used as analysis equipment. The color change of the specimens was observed to calculate ${\Delta}E$ value throughout 2 days, 3 days, 4 days, and 5 days and this was analyzed and the following result was obtained. Results: Snap's ${\Delta}E$ value was bigger than Vipi block(p<0.05). Red pepper paste had the largest impact on the color change of resin(${\Delta}E$), followed by soy sauce and coffee(p<0.000). With the passage of time, ${\Delta}E$ value was inversely(-) related and decreased somewhat(p<0.000).

• 한국안전학회지
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• 제29권4호
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• pp.42-47
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• 2014

This paper is aimed to investigate and analyze of characteristic for electrical equipment and work environment for the small-scale site. In order to investigate and analyze electrical equipment and work environment for preventing electric shock disaster in construction sites, 50 small-scale construction sites and 12 large-scale construction sites are selected. This paper completed site investigations of low-voltage equipment and the portable electric machine and equipment in 12 large-scale construction sites and 50 small-scale construction sites. The findings were about the electric shock environment relevant to the ground-relevant equipment, the panel board, the protection tools, the sockets, the temporary wiring system, the portable and movable electric machines and equipments in small-scale construction sites. Finally, this study analyzed the domestic and foreign relevant standards and regulations and these findings can be utilized as educational data warning electric shock risk caused by electric equipment in small-scale construction site.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.751-756
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• 2001

Permanent-Form is one of system forms for reducing human labor, work costs, oscillation, noise, construction wastes and so on. Permanent-Form is made from precast method in facilities. and carried in construction site to assemble with no demolding. The biggest expense to produce Permanent-Form is about manufacturing mold. To satisfy various size of building member, the same number of manufacturing mold is needed. In this paper, studied about manufacturing mold module for acquiring economic merit and construction member safety. Permanent-Form is member stress and structural analyzed if temporary equipment were used. The result of this study is below. (1) Column sizes of Permanent-Form are 47 kinds of prototype that based on Modular coordination's basic module. 4 pieces or 6 pieces are composed basically. (2) For beam size modular coordination, standard height and width of beam are 150mm and 100mm. It brings 24 kinds of prototype. 4 pieces or 5 pieces are composed basically. (3) Structural analysis value of modular member is like this Column member shows 9.4 to 85kgf/$cm^{2}$ stress distribution and beam member shows 6.3 to 95kgf/$cm^{2}$ stress distribution. Constructing permanent form could have structural safety with use of temporary equipment

• 한국안전학회지
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• 제33권4호
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• pp.46-53
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• 2018

This study examined the maximum resistant moment and nonlinear rotational stiffness of wedge joint between the vertical and horizontal members of system supports. To examine the maximum resistant moment and propose the nonlinear rotation stiffness of wedge joint, 6 specimens were tested and additional 3 specimens, where the horizontal member was welded to the vertical member, were tested to compare the moment capacity of wedge joints. The average maximum moment in the tested wedge joint was 1.183 kNm which represented about 70 % of the maximum moment developed in the welded specimens. And, as simulating nonlinear rotational stiffness of the wedge joint, a tri-linear model was suggested. The rotational stiffness was estimated as 23.095 kNm/rad in first stage, 7.945 kNm/rad in second stage, and 3.073 kNm/rad in third stage. For the failure mode, the specimen with the wedge joint showed the failure of joint between vertical and horizontal members. However, the specimen with welded joint represented the yielding of horizontal members.

• 한국산업융합학회 논문집
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• 제22권6호
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• pp.797-805
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• 2019

An important problem of offshore plant process piping is equipment accidents due to the removal of fine metal debris and foreign substances in the pipes that deliver fluids such as hydraulic oil, lubricating oil and thermal oil. Temporary flushing equipment to remove debris uses fluid equipment of centrifugal pump and gear pump to prevent equipment accident of offshore platform. The equipment manufacturer requires the shipyard to have a cleanliness rating inside the pipe to meet the international standards ISO4406 and NAS1638 quality levels to prevent damage to the equipment sold. The quality of the internal flushing of pipes conforms to the regulations suggested by the equipment manufacturer. In this paper, three types of electric heater capacity, which is a method of evaporating and removing water inside a pipe during an oil flushing process, were compared. In addition, the study was conducted to remove the flushing oil in the pipe and to improve oil quality.

• 한국안전학회지
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• 제32권4호
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• pp.59-65
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• 2017

This study examined the stakeholder cognition of the safety certification marking system by surveying manufacturers, lessors, and users. In addition, among various issues about safety certification marking systems, the improvement of safety certification marking contents was suggested in order to guarantee quality of temporary equipments. The results by statistical method show that it is necessary to increase of users' understanding about the safety certification marking system. In addition, the quality management system of temporary equipments should be introduced to control the actual condition that temporary equipments of various product companies are mixed in a site during removal and reuse processes. For detailed marking contents, it is recommended that a certification mark, an identification number, and the production year should be displayed and the manufacturer name could be selectively presented. Detail informations such as a safety certification number, a product company, a model type or name, a specification, a weight, a product number, and the location of a certification mark should be identified by the identification number.

• 조명전기설비학회논문지
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• 제24권1호
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• pp.71-77
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• 2010

뇌서지 보호는 오늘날 대부분의 전기전자기기에 있어 중요한 문제 중 하나이다. 그리고 뇌서지 보호를 위한 대다수 SPD의 가장 주요 부품으로 MOV가 사용된다. 본 논문에서는 다양한 타입의 MOV 기반 SPD를 조사하고 낮은 MLV특성의 부작용에 대하여 실험하였다. 실험결과로서 상대적으로 낮은 MLV특성은 실제 현장에서 발생 가능한 TOV 고장 상태하에서 더 큰 고장률로 나타날 수 있으며, 피보호기기보다 우선하여 소손될 수 있음을 알 수 있다. 결국 안전면에서 SPD는 높은 TOV내력과 신속한 단로기의 동작이 요구된다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2009년도 춘계학술대회 논문집
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• pp.344-347
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• 2009

Surge protective devices (SPD) have a special position because of the expectation that they perform an effective protective function against various kinds of surges. However, there exists a misconception that the SPD satisfying lower measured limiting voltage (MLV) should also protect equipment against temporary overvoltages (TOVs) as well. This paper inspects various types of MOV based SPDs and carry out experiments on the side effects of the low MLV characteristics. The experiment results show that a low MLV could cause a higher TOV-induced SPD failure rate in the field.

• 한국안전학회지
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• 제34권5호
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• pp.63-71
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• 2019

Work Guideline of Construction Quality Management was revised in July 2017, and it has changed the perception of scaffolding in South Korea. The on site investigation and survey was performed on manufacturers, leasing companies, and quality inspection agencies regarding the compliance with the guideline for the scaffolding and the related components brought to the site. Moreover, the related guidelines and identified unsatisfactory quality management items were analyzed by each subject. As a result, the major factors that cause the problems were reasonably deducted. The related regulations to prohibit the delivery of faulty scaffolding components to the construction site in order to secure the safety of the temporary structure was suggested.