• The Transactions of the Korean Institute of Electrical Engineers P
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• v.55 no.2
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• pp.110-114
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• 2006

This paper describes the accident analysis by modelling the current transformer mounting in a metal-clad switchgear at 22.9kV. In analyzing the accident, the reconstruction at the current transformer mounting(VCB connecting guide) has to be taken into account. The accident was modelled as a 3-phase ground fault occurring between the end plate of 22.9kV lines and the safety shutter at the current transformer mounting of the VCB inside the metal clad switchgear. Since the outside maintenance of the metal clad switchgear is restricted by the enclosed compartments, Its circumference has to be kept clean. Through the reconstruction results, it was confirmed that the fault of the enclosed switchboard could be reduced when the shutter made of Fe material was chanted into an insulation.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1053-1055
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• 2005

At the moment, the operation methods for pad switch are different due to the differences of the manufacturer and the types or ratings of pad switches; accordingly, various types of the operation tools are required for the operation of pad switch. Sometimes, the operator uses conductive tool made of metal, or there is no sufficient space around the pad switch for operation and these kinds of problems are related with the potential safety accidents of the operators. Therefore, to solve these problems, new universal operation tool for pad switch, which only needs the change of operation head for various types of pad switches, has been developed. With this new tool, durability and safety of the operator can be achieve.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.5
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• pp.881-888
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• 2022

Servo presses are used in variety of ways in industry throughout the production and assembly lines of machine parts. The bottom of the servo press is fixed to a bed or a tabletop, and the press cylinder continuously operates under vertical upward loads. In this research, a static structural analysis was performed by simplifying 3D model of the servo press, and the maximum deformation was applied to the clamp and bolt. The maximum value of Von Mises stress was reported in this paper. The result was used to calculate the safety factor, and it was confirmed that the design was conservative.

• Safety and Health at Work
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• v.2 no.1
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• pp.39-51
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• 2011

Objectives: This study was designed to evaluate exposure levels of various chemicals used in wafer fabrication product lines in the semiconductor industry where work-related leukemia has occurred. Methods: The research focused on 9 representative wafer fabrication bays among a total of 25 bays in a semiconductor product line. We monitored the chemical substances categorized as human carcinogens with respect to leukemia as well as harmful chemicals used in the bays and substances with hematologic and reproductive toxicities to evaluate the overall health effect for semiconductor industry workers. With respect to monitoring, active and passive sampling techniques were introduced. Eight-hour long-term and 15-minute short-term sampling was conducted for the area as well as on personal samples. Results: The results of the measurements for each substance showed that benzene, toluene, xylene, n-butyl acetate, 2-methoxy-ethanol, 2-heptanone, ethylene glycol, sulfuric acid, and phosphoric acid were non-detectable (ND) in all samples. Arsine was either "ND" or it existed only in trace form in the bay air. The maximum exposure concentration of fluorides was approximately 0.17% of the Korea occupational exposure limits, with hydrofluoric acid at about 0.2%, hydrochloric acid 0.06%, nitric acid 0.05%, isopropyl alcohol 0.4%, and phosphine at about 2%. The maximum exposure concentration of propylene glycol monomethyl ether acetate (PGMEA) was 0.0870 ppm, representing only 0.1% or less than the American Industrial Hygiene Association recommended standard (100 ppm). Conclusion: Benzene, a known human carcinogen for leukemia, and arsine, a hematologic toxin, were not detected in wafer fabrication sites in this study. Among reproductive toxic substances, n-butyl acetate was not detected, but fluorides and PGMEA existed in small amounts in the air. This investigation was focused on the air-borne chemical concentrations only in regular working conditions. Unconditional exposures during spills and/or maintenance tasks and by-product chemicals were not included. Supplementary studies might be required.

• Korean Institute of Interior Design Journal
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• v.19 no.5
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• pp.11-20
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• 2010

User-oriented Design is necessary in planning the interior design of Metropolitan Railroads trains, since this is a typical means of transportation in this modem society and all ages people with different body scale use this facility. However, there are little studies about facility panning and zoning of Metropolitan Railroads train considering users. Therefore, in this study, after completing the checklist based on the current legal standards of facility installation of South Korea and Japan, we examined user's facility and suggest several improvement of the opening 14 metropolitan railroad lines in Seoul. Then, we evaluated this facilities according to 41 standards; general facility(24 standards), safety facility(4 standards), guide facility(11 standards), other facility(4 standards). The result of this study may be summarized as follows. 1) General facility has to be designed to obtain lots of room for storage and this facility should be fixed up tightly with secure system. 2) Safety facility should be designed to minimize a difference of floor-level between threshold of train and ground. Also, using various color and material could help passengers to distinguish different space and facility. 3) Guide facility should be designed to guide passengers to the accurate direction with proper sign design in the pathway of Metropolitan railroad train. Also, more various color, which based on the research about physiological and psychological effect, should be used to guide people. 4) Other facility should equip more visual system using common good and informative contents. Through this study, we try to understand the current interior physical condition of Metropolitan Railroads trains. However, for future studies, it is expected to supplement evaluation standards considering aesthetic design, environmental improvement of indoor air quality and the satisfaction and demand of Metropolitan Railroads trains.

• Journal of Navigation and Port Research
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• v.43 no.6
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• pp.344-352
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• 2019

A coupled analysis was performed between the riser to develop oil and gas in ultra-deepwater and the moored floating body. In general, the safety of the riser is conservatively evaluated by considering the maximum offset excluding the coupled analysis with the floating body. In this study, the safety of the riser was analyzed by considering the coupled motion analysis of the moored floating body. The riser is considered steel lazy wave riser (SLWR) applied in the deep sea, and the floating body is determined to FPSO. The methodology was presented on coupled and uncoupled analysis. The coupled effects were analyzed according to the incident wave headings in intact and damaged conditions of mooring lines. The tension of mooring lines, the motion of the floating body, and riser responses were analyzed according to the loading conditions.

• Journal of Food Hygiene and Safety
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• v.19 no.4
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• pp.185-192
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• 2004

Generic HACCP models for bakery products may help HACCP implementation at the wholesale bakery production lines easier. When baking, the internal temperature of bakery products went up to $85^{\circ}C$, which resulted in gelatinization of starch. Considering the characteristics of bakery products, general sanitation control procedures are the main target tool to keep bakery products safe. Monitoring of pathogenic microorganisms at bakery plant environment including production lines was carried out. At the wholesale bakery environment pathogenic microorganisms were detected. It gave a clue that general sanitation control procedures should be implemented for safe bakery products supply. Hazard analysis of raw materials and processing of bakery products, and determination of critical control points and critical limits at the wholesale bakeries lead to present generic model of bakery product HACCP plan. CCPs for the wholesale bakery products may be applied and modified for the implementation of HACCP plan at the wholesale bakery plant.

• Journal of the Korean Geotechnical Society
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• v.18 no.5
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• pp.27-35
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• 2002

To construct pipe lines, culverts, or other utility lines, temporary slopes formed by excavating the compacted embankment are frequently met with in the field. Ignoring stability analyses for such slopes and applying inappropriate slope inclinations often result in safety problems. In this study, stability of such slopes were investigated considering the influence of anisotropic shear strength of the layered compacted ground. A series of stability analyses were conducted for slopes varying the slope angle and the height, and assuming isotropic and anisotropic shear strength conditions, respectively. The anisotropic shear strength of the compacted soil was determined from the direct shear test for layered soil blocks varying the inclination angle between the horizontal shear surface and the direction of the soil layer. As a result of the analyses, it has been concluded that the appropriate slope inclination f3r a temporary slope could vary in accordance with the consideration of anisotropy. However, the factor of safety as well as the location of the failure surface did not show significant variation.

• Journal of the Korea Safety Management & Science
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• v.13 no.4
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• pp.71-79
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• 2011

The work environment of locomotive cabs has long been an important issue in the design of railload systems since it is quite critical in terms of system's operational safety. It is getting more attention as the running speed of the trains goes up these days. To this end, this paper describes how to systematically construct a DB for the requirements set in the course of the improvement process for the aforementioned cab work environment. As a solution approach, we have adopted the requirement architecture concept to cover the whole activities required to do such as in requirements generation, DB construction, change management, and traceability management. Specifically, based on the requirement architecture framework a requirement process to collect requirements for improvement is discussed, and the guide lines are suggested for verification and validation of the developed requirements. In addition, a base schema and requirements templates are developed, which will be used in generating requirements and constructing a DB. Finally, it is demonstrated how the requirements DB for locomotive cabs can be constructed using a computer-aided tool in an integrated fashion.

• The Journal of Information Systems
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• v.31 no.2
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• pp.239-261
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• 2022

Purpose The purpose of this study is to explore and compare changes in tourist opinion during the COVID-19 pandemic. Since the COVID-19 outbreak has caused changes in all areas of our lives, the conditions related to confinement during a lockdown have led to changes in tourists' habits and behaviors. Design/methodology/approach To analyze opinion changes about tourist attractions, this study performed topic modeling by summarizing topics into five dimensions: management, scenery, price, suggestion, and safety; then, based on the topic modeling results, sentiment analysis and emotion analysis were conducted to explore the change of tourists' opinion during the COVID-19 pandemic. Findings According to the results, this study confirmed the pandemic's positive effect on tourists' opinions about attractions after the COVID 19 outbreak. Presumably due to the absence of lines and crowed. Moreover, the dimension 'Safety' started to appear in US tourists' attractions reviews only in the period after the outbreak and during the mass vaccination. These results mean that tourists started to care more about safety due to the impact of the COVID-19 pandemic.