• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2538-2539
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• 2000

송배전 system에서 모선관리 및 운용에 있어 초고압 차단기는 매우 중요한 역할을 담당하고 있다. 선로의 운전상태와 차단기의 투입 상황 인식 및 확인은 필수요건이다. 이러한 차단기의 운전상태를 전자적인 신호성분을 검지하여 비접촉식 개폐 확인 unit가 필수적으로 대두되고 있다. 이 unit는 고신뢰성, 고안정성을 요구하며 정확한 표시가 필요하다. 송배전의 모든 System에 적용 가능하며 적용시 선로와 차단기의 운전 및 보수에 절대적인 안정성을 제공한다.

• 한국GIS학회:학술대회논문집
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• 한국GIS학회 2008년도 공동춘계학술대회
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• pp.541-546
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• 2008

본 연구에서는 현재 생활 속 위치정보의 중요성이 강조되고 있고 각종 GPS 단말기들의 보급이 증가되고 있는 상황에서 휴대용 GPS의 주어진 사양과 성능 및 정확도의 검증을 수행하여 보았다. 도심지역과 산악지역을 RTK 방식으로 측정한 위치좌표를 기준으로 하여 3종의 휴대용 GPS 단말기를 통해 측정한 위치좌표를 비교한 후 각 단말기의 위치별 정확도를 통계적 분석 후 지도상에 범례를 사용하여 표현하였다. 그 결과, 도심지역의 경우는 주위의 건물에 의해 정확도에 영향을 많이 받았으며 산악 지역의 경우에는 수목이 우거진 정도에 따라 정확도가 다르게 나타났다. 이러한 정확도를 지도로 표현한 데이터를 이용하여 정확도에 따른 휴대용 GPS의 활용방안에 대하여 사용자에게 제시할 수 있을 것이며 앞으로도 시각 장애인 네비게이션 개발 등에 활용될 수 있을 것으로 사료된다.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2001년도 춘계학술대회 논문집
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• pp.238-242
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• 2001

In this paper, we proposed an optimal identification method of the membership functions and the numbers of fuzzy rule base for the stabilization controller of the Thermal process control system by RVEGA. Although fuzzy logic controllers and expert systems have been successfully applied in many complex industrial process, they must rely on experts knowledges. So it is difficult in determination of the linguistic state space, definition of the membership functions of each linguistic term and the derivation of the control rules. To verify the validity of this RVEGA-based fuzzy controller, Thermal process control system, with strong nonlinear dynamics, was selected for application of this algorithm and compare with PI controller, and the empirically improved fuzzy controller.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2334-2339
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• 2008

This paper proposes an improved mathematical model for predicting the frosting behavior on a two-dimensional fin considering the heat conduction of heat exchanger fins under frosting conditions. The model consists of laminar flow equation in airflow, diffusion equation of water vapor for frost layer, and heat conduction equation in fin, and these are coupled together. In this model, the change in three-dimensional airside airflow caused by frost growth is accounted for. The fin surface temperature increased toward the fin tip due to the fin heat conduction. On the contrary, the temperature gradient in the airflow direction(x-dir.) is small throughout the entire fin. The frost thickness in the direction perpendicular to airflow, i.e. z-dir., decreases exponentially toward the fin tip due to non-uniform temperature distribution. The rate of decrease of heat transfer in the airflow direction is high compared to that in the z-direction due to more decrease in the sensible and latent heat rate in x-direction.

• 수산해양교육연구
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• 제28권5호
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• pp.1348-1357
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• 2016

This study was to describe the process on experiences of self-leading leisure activities and develop a substantive theory that explains lifestyle in middle-aged office workers. The participants were 12 persons who had participated in self-leading leisure activities. Data were collected with in-depth interviews and analyzed by grounded theory in Strauss and Corbin. Through analyzing process, 28 concepts, 14 subcategories, and seven categories were deduced. The periods of process were divided four stages, plateau, the phage of recognition in social duties, the phage of strengthen in competency, and the phage of reconstruct in successful lifestyle. The core category, 'disclosing of self-esteem' incorporated the relationship between and among all categories and explained the process. The findings indicate that self-leading leisure activities helped to their own health and developed their social activities. Therefore, we would consider in developing health promotion program about favoring leisure activities factors for the middle age office worker.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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• pp.256-261
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• 2008

In this study, frost behavior on two dimensional fins of a heat exchanger was experimentally investigated. Temperature distribution on a 2-D fin surface and frost properties were measured in the directions perpendicular to and parallel to airflow. The results indicated that the temperature gradient in the direction perpendicular to airflow was large because of fin heat conduction, while that in the direction parallel to airflow was very small. Frost thickness in the airflow direction decreased from the leading edge towards the trailing edge of the fin due to leading edge effect. The reduction rate of frost thickness in the airflow direction, however, was very small compared with that in the direction perpendicular to the airflow, as affected by the temperature distribution.

• 한국항만경제학회지
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• 제21권3호
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• pp.83-113
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• 2005

In this study, for purpose of searching for measures to lower the logistics costs which is one of the most difficulties for the small-medium sized manufacturers in Pusan and Kimhae, those manufacturers were surveyed with questionnaire about the facts in the export logistics costs, difficulties related to the costs, and measures they thought for lowering the cost. Taking account of findings from the survey, the comprehensive measures of saving the export logistics costs were to be proposed. In the surveyed manufacturers, the problems they thought over export logistics costs lied in short logistics information and transportation-related difficulties in cargo and distribution, insufficient standardization in packaging and the shortage of material handling equipments in unloading. In transportation, frequent non-fulfillment of in-time shipment, cost increase including over consumption of transportation time due to traffic jam, and the biased heavy use of inland transportation were pointed out as problems. In customs clearance, logistics information, and marine insurance, addressed were complexity in custom clearance and bonded transportation procedures, and the shortage of software and hardware to construct logistics information system.

• 동아시아식생활학회지
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• 제21권2호
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• pp.277-283
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• 2011

The goal of this study was to make more efficient use of Ligularia fischeri which has both medical and cooking applications after freezing and drying. We manufactured Sulgidduk containing 0, 2, 4, 6 and 8% of Ligularia fischeri powder. Chemical analysis showed that Ligularia fischeri powder contained, 5.77% water, 19.97% crude protein, 1.89% crude fat, 13.12% crude ash, and 9.73% crude fiber. The water content of Sulgidduk to which Ligularia fischeri was added ranged from 37.72~40.20%. As more Ligularia fischeri was added, the L value and 'a' value increased, while the 'b' value did not significantly change. Optimal preference was for a 4% content of added Ligularia fischeri powder. Based on the results of this experiment, Sulgidduk manufactured with added Ligularia fischeri powder showed less hardness than the control group throughout a period of storage, and adequate addition of Ligularia fischeri powder can effectively enhance the storability of Sulgidduk containing Ligularia fischeri.

• 동아시아식생활학회지
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• 제21권2호
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• pp.250-256
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• 2011

The findings of this study into the quality of fresh pasta noodles containing different amounts of the lyophilized citrus peel powder are as follows. The higher the amount of the citrus peel powder in the pasta, the higher was its WRC. The Hunter's values, whether L, a, and b all increased in both cooked and raw noodles. The higher the amount of the citrus peel powder, the less the level of tensions and the lower the setback values. These results suggest that the citrus peel powder might have a controlling effect on retrogradation. As for the characteristics of cooked pasta noodles, the weight decreased; the volume increased; and the moisture absorptive power also increased. The tasters' preferences were in the following order: 3%>0%>5%>7%>1%. In other words, a citrus peel powder content of 3~5% appears to be most appropriate.

• 항공우주기술
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• 제1권1호
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• pp.55-64
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• 2002

수명 12년의 중형급 정지궤도 통신위성의 추진시스템 개념설계과정이 기술된다. 임무해석을 통해 주어진 전속도 증분량(ΔV)을 사용하여 임무수명기간동안 필요한 추진제 양이 계산되었으며 이 값을 기초로 하여 연료탱크와 산화제 탱크의 형상을 설계하였고 필요한 가압제의 양과 가압제 탱크의 압력을 구할 수 있었다. 구조계와 Trade-Off Study를 통해 추력기의 배치와 로켓엔진의 개수, 탱크의 배치 등을 결정하였으며 전체적인 추진시스템 개념설계 형상이 최종적으로 제시된다.