• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1233-1238
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• 2007

In recently, our social is entering to service infinite competitive time., So If companys don't give satifactory and an impression customers, they don't exist. The Companies that operate railway are promoted(Seoul metro). The Korail, Seol metropolitan Rapid Transit Corperation, Incheon Rapid Transit Corporation), they are into a stronger competitor. So the service for customer is more inportant to improve the image and administration than before. Especially, station workers who work near the customer are important for cooperation image. But, there are only a few employees to operate the station like ticketing in railway station, There aren't reinforcement the service employees and expanse the utility system. especially, since the transportation card is introduced in 1996, the customers who use the T-Money card are increased. So the change of service system is necessary to provide a substantial service to customer. This paper derives the problems through analysising the operating system of station, and presents the improvement to provide substantial services to customer

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.206-211
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• 2000

The accelerated testing technique using the equivalent load condition plays an important part in development process. However, in the industrial field, the theoretical background and advantages of this accelerated testing technique have been lack of understanding. Because the environmental durability condition forms the foundation of the accelerated testing technique, it is important to analyze the loading components and damage in service environment. In this work, we present the theoretical background and process for accelerated testing, and introduce our accelerated equivalent load analysis program. We developed the GUI program, and the user can easily obtain the result by selecting the program module.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.10-13
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• 2008

This study suggests a virtual construction technology for railway project using virtual reality and attempts to develop a virtual construction system. For the study, the final system include the layout review function that can rearrange designed element for optimal placement and the earthwork simulation function that can visualize filling and cutting work using central line of earthwork section. Those functions can improve applicability of 3D and 4D object in the design and construction phases of railway project.

• Korean Management Science Review
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• v.21 no.2
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• pp.43-60
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• 2004

Every iteration of interior-point methods of large scale optimization requires computing at least one orthogonal projection. In the practice, symmetric variants of the Gaussian elimination such as Cholesky factorization are accepted as the most efficient and sufficiently stable method. In this paper several specific implementation issues of the symmetric factorization that can be applied for solving such equations are discussed. The code called McSML being the result of this work is shown to produce comparably sparse factors as another implementations in the $MATLAB^{***}$ environment. It has been used for computing projections in an efficient implementation of self-regular based interior-point methods, McIPM. Although primary aim of developing McSML was to embed it into an interior-point methods optimizer, the code may equally well be used to solve general large sparse systems arising in different applications.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.4
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• pp.285-290
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• 2005

Mechanical properties of rubber mat are influenced by many factors such as compounding ingredients and states of cure, process of rubber, and fillers. Our study aim is to investigate influence of N-isopropyl-N'-chloro-P-phenylene diamine antioxidant on the thermal aging and ozone cracking. In this work, the degradation of antiblastic rubber mat was studied and suggested mechanism to involve two-types of degradation, thermal-aging and ozone-cracking both of which can be contained antioxidant or non-antioxidant.

• Journal of the Korean Home Economics Association
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• v.49 no.3
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• pp.113-121
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• 2011

This study developed a method of calculating dynamic wearing ease (DWE) to make patterns for coverall work clothing. The DWE was measured from 3D body scan data of women in their 20's (n = 10). The body postures adopted for measuring the DWE were sitting and deep bending postures. Three types of experimental patterns (A, B, C) were developed. The DWE was applied at the waist and hip lines of the pattern. The location and size of the DWE varied from one pattern to another. For pattern B, DWE of 8.8cm was applied at the back of the waistline. For pattern C, 5.3cm was applied at the waist for the center back line, and 3.5cm was applied at the under hip level. The comfort of the experimental clothing was evaluated in six body postures. The results showed that patterns B and C were comfortable at the crotch, shoulders, and arm pits. Pattern C was comfortable at the hip and crotch areas in the arms lifting-up posture and the stepping-up posture. The appearance and fit of the experimental clothing were evaluated by the panels. Patterns B and C fitted better than pattern A at the abdomen. The results suggest that DWE should be applied at the waist and hip levels for making coverall work clothing patterns.

• Journal of the Korean Society of Safety
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• v.36 no.4
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• pp.54-61
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• 2021

The purpose of this paper is to verify if safety managers must bear stress from additional tasks whenmanaging smart safety technology applications on construction sites. We conducted a survey of 133 safety managers who had experienced managing both safety management and smart safety technology applications at construction sites, and used the SPSS Statistics 25 and AMOS 22 programs to analyze the survey's logicality and the data that we collected. We found that the work burden caused by assuming additional tasks to manage smart safety technology applications affected the stress that safety managers experience when working at construction sites. The stress caused by an increased work burden led construction site safety managers to feel dissatisfied with their jobs. This finding indicates that both on the original job and on additional tasks are entirely mediated. Based on this finding, I suggest that the South Korean government should establish smart safety technology applications, thus reducing the work burden and increasing the job satisfaction for construction site safety managers.

• Korean Journal of Culture and Social Issue
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• v.26 no.4
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• pp.409-433
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• 2020

This study attempted to verify the relationship between job burnout and organizational citizenship behavior among South Korean soldiers in the Navy force by applying the Job Demands-Resource Model and Conservation of Resource Theory, and the moderated mediating effect of social capital through the work engagement and smartphone use. The mediating effect of work engagement and the moderating effect of social capital via smartphone use were examined in the relation between job burnout and organizational citizenship behavior. We combine the mediation effect model and the moderation effect model and tested the moderated mediation effect. To perform this study, the survey was conducted on the navy soldier on duty, and total of 324 data were analyzed. The results of this study were as follows: the complete mediation effect of work engagement in the relation of job burnout and organizational citizenship behavior was verified, social capital via smartphone use moderated the relation between job burnout and work engagement, and the moderated mediation effect of social capital via smartphone use in the relation between job burnout and organizational citizenship behavior through work engagement was identified. Based on the results, implications, limitations, and future research directions of the current study were discussed.

• Journal of the Korean Solar Energy Society
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• v.35 no.5
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• pp.11-19
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• 2015

In this paper, EP-Kalina cycle applying liquid-vapor ejector and motive pump is newly proposed. In this EP-Kalina cycle, the liquid-vapor ejector is used to increase pressure difference between inlet and outlet of the turbine. Also the motive pump enhances the performance of liquid-vapor ejector, resulting in increase of system efficiency of OTEC cycles. The comparison cycles in this study are basic, Kalina, EKalina and EP-Kalina ones. The pump work, net power, APRe, APRc, TPP and system efficiency of each cycle are compared. In case of net power, EP-Kalina cycle is lowest among the cycles due to the application of the motive pump. But, the net power difference of cycles seems to be minor since the pump work of cycles is merely about 1kW, compared to turbine gross power of 20kW. The system efficiency of EP-Kalina cycle shows 3.22%, relatively 44% higher than that of basic OTEC cycle. Therefore, the system efficiency is increased by applying the liquid-vapor ejector and the motive pump. Additional performance analysis is necessary to optimize the proposed EP-Kalina cycle.

• Journal of Power System Engineering
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• v.20 no.6
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• pp.87-92
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• 2016

This research dealt with performance characteristics of OTEC system applying an ejector and additional pump. Each system using five kinds of working fluids was analyzed, and primary parameters with respect to entrainment ratio were examined: Turbine gross power, evaporation capacity, pump work, efficiency and volume flow ratio. The primary results were as following. The efficiency of ejector-pump OTEC system was dependent on entrainment of the ejector. The degree of efficiency change was different from applied working fluid, and amount of pump work was turned out to be primary factor affected system efficiency. Meanwhile, optimized entrainment ratio was different from applied working fluid since their different vapor density. System efficiency at optimized entrainmet ratio of each working fluid was around 5%, showing minor difference each other.