• 산업공학
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• 제14권2호
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• pp.205-209
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• 2001

The number of tunnel has fast increased with the rapid expansion of highway network. Tunnel should be designed to provide for drivers both safety and pleasant driving conditions. In this perspective, the design for tunnel lightning is very important in order to provide its safety, pleasantness, and cost-efficienty of maintenance, all of which should be considered and analyzed for a better tunnel lighting. This paper attempts to compare the low-pressure sodium lamp, which has usually been used for tunnel lighting, with the fluorescent lamp, which we consider as an alternative for the former. In an effort to determine the number of lamps to meet the required illuminance in the tunnel, this research employs a simulation technique which would allow us to conjecture, with the aid of basic model, the life cycle cost for illumination per each tunnel. This analysis is expected to provide a basic method and related information for tunnel development and design.

• Industrial Engineering and Management Systems
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• 제3권1호
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• pp.59-62
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• 2004

The number of tunnel has fast increased with the rapid expansion of highway network. Tunnel should be designed to provide for drivers both safety and pleasant driving conditions. In this perspective, the design for tunnel lightning is very important in order to provide its safety, pleasantness, and cost-efficiency of maintenance, all of which should be considered and analyzed for a better tunnel lighting. This paper attempts to compare the low-pressure sodium lamp, which have usually been used for tunnel lighting, with the fluorescent lamp, which we consider as an alternative for the former. In an effort to determine the number of lamps to meet the required illuminance in the tunnel, this research employs a simulation technique which would allow us to conjecture, with the aid of basic model, the life cycle cost for illumination per each tunnel. This analysis is expected to provide a basic method and related information for tunnel development and design.

• 전기학회논문지
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• 제66권6호
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• pp.905-910
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• 2017

As the development of BESS(Battery Energy Storage System), the application of BESS in load frequency control is considered as effective method. So, KEPCO(Korea Electric Power Corporation) have installed about 236MW ESS for GF(Govner Free) function from 2014. In this paper, we implemented Simulink Model for KEPCO GF ESS and analyzed one year historical operation data generated by Simulink model and actually measured frequency data. The operation results were divided into action for maintaining SOC and frequency. In addition, we also analyzed cycle life of GF ESS using two ESS cycle life model. We concluded the ESS cycle life models are not appropriate, because Most of the SOC swing in operation results are below 10%.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2003년도 학술대회논문집
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• pp.81-86
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• 2003

최근 대형 전력시설물에 대한 VE 와 LCC 기법의 도입은 여러 가지 형태로 수행되고 있으며, 일반적으로 전력 시설물의 비용을 생각할 때 그 초기투자비만을 대상으로 평가하는 경향이 있으나, 시설물의 총 생애비용 (보전비, 수선비, 개선비, 운용비, 전력비등)을 동시에 고려하여야 한다. 본 연구에서는 간선설계에서 장거리 급전시 전압강하로 인한 동손비를 고려한 설계기법과 내구년한에 따른 총생애비용기법을 적용하여 타당성을 입증하였다.

• Parasites, Hosts and Diseases
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• 제39권3호
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• pp.227-232
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• 2001

Eight dogs were experimentally infected with Sarcocystis by oral inoculation of cardiac muscle from naturally infected cattle. The infected dogs commenced discharging of sporocysts in the feces after 10 to 12 days of inoculation, and continued until 20 and 35 days after inoculation. Three dogs were reinfected with cardiac muscle from the naturally infected cattle. Sporocysts reappeared in the feces on 12 to 13 days after reinfection. Sarcosystis sporocysts collected from the experimentally infected dogs were fed to each of the two 30-day-old Korean native calves. The infected calves remained clinically normal, except for the high fever (${\geq}{\;} 40^{\circ}C$) and decreased hematocrit values on day 30 to 40 post inoculation. Muscular cysts of Sarcocystis were found from infected calves on day 40 post inoculation. Proliferative forms of Sarcocystis were also observed in the muscle of infected calves. These results suggest that the Sarcocystis cruzi found in Korean native cattle has a 2-host life cycle with dogs as the definitive host and Korean native calves as the intermediate host.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.424-426
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• 2004

As power demand increases gradually, the call for underground transmission system increases. But it is very difficult and high in cost to construct new ducts and/or tunnels for power cables in metropolitan areas. HTS (High Temperature Superconducting) cable has the several useful characteristics such as increased power density, stronger fields and/or reduced losses. Therefore HTS cable can allow more power to be moved in existing ducts, which means very large economical and environmental benefits. In these days, companies world-wide have conducted researches on HTS cable. A development project for a 22.9kV class HTS cable is proceeding at a research center and university in Korea. In this paper, we investigate the expected price of HTS cable to have a merit in viewpoint of economic aspect. First, life-cycle cost of conventional cable is calculated and based on this, the expected price of HTS cable is evaluated, which HTS cable is competitive against conventional cable.

• 한국컴퓨터정보학회논문지
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• 제6권4호
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• pp.30-37
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• 2001

전통적 개발방법론에서는 요구분석단계에서 요구사항들이 한번 정리되면 이들은 개발이 완료될 때까지 변경이 없을 것으로 간주한다. 그러나 현실적으로는 개발기간 중 목표 시스템의 구체화, 정보기술의 발전, 적용환경의 변화 등으로 인하여 요구사항은 끊임없이 변화하게 된다. 본 논문에서는 개발방법론에서 미흡한 요구사항 관리를 개선하기 위하여 요구사항의 관리를 전체 개발 생명주기로 확대하고, 지속적으로 발생하는 요구사항의 변경을 효율적으로 관리할 수 있는 요구사항의 명세화 방안을 제시한다.

• 전기학회논문지
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• 제67권12호
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• pp.1717-1722
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• 2018

Parts and units of 8200 series electric locomotive are aging, but and source technology is not secured. As a results, maintenance costs are increasing steadily due to using expensive substitute parts. Therefore, various studies have been conducted to reduce maintenance costs. In this paper, the life cycle cost(LCC) of the developed and conventional products were compared and analyzed about main conversion system in 8200 Series electric locomotive. As a result of analysis, the material cost was the highest in the conventional product among the various item costs. On the other hand, it is confirmed that preventive cost was the highest among the costs about the developed product.

• 한국기계가공학회지
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• 제18권5호
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• pp.53-59
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• 2019

Continuous ship unloaders (CSUs) are used for the uninterrupted transport of material in processing industries, power plants, and harbors in accordance with the stream rate of the material. This study analyzed the structural integrity and fatigue life of a CSU structure using finite element structural analysis in ANSYS APDL software. The stress varied greatly depending on the luffing angle and the slew angle of the boom conveyor. The structural integrity of the CSU girder was evaluated by applying ASME BPVC Section VIII Division 2. The fatigue cycle at the angle with the greatest stress difference was calculated. The fatigue cycle was calculated by applying the JIS B 8821:2013 fatigue curve. It was confirmed that the fatigue cycle of the CSU satisfies the allowable fatigue of 200,000 cycles.

• 아태비즈니스연구
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• 제10권4호
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• pp.167-180
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• 2019

The purpose of this paper is to explore Laos mysterious 'Plain of Jars' area in a village. 'The Plain of Jars' site has been proposed for listing as a UNESCO World Heritage Monument. The study used convenience sampling and surveyed tourists who visited Tonghahin in Xieng Khouang. The results of this study are summarized as follows: First, Tonghahin is introduction stage from the tourism life cycle due to lack of basic infrastructure such as road condition, transportation, information service, etc,. Second, this study examined the ways to improve methods such as adminstration system and hospitality service manual for tourist site. Thereafter, third, to develop each attraction, they have come with better tourism products. These things are foresight-able to-do list for nomination as the UNESCO World Heritage. The recommendations and suggestions for future research are also discussed.