• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.8
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• pp.412-417
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• 2000

TV ghost interference can be described as passive interference by the conducting part of transmission lines. In order to survey this interference from large-sized overhead EHV (extra high voltage) transmission line, TV reception quality was measured in the vicinity of that before and after construction. Instrumentation system was composed of ghost analyzer, TV received field intensity meter, VHF/UHF antennas, TV monitor and so on. The system is installed inside the vehicle. TV field intensity and PDUR (Perceived Desired wave to Undersired wave Ratio) are measured to evaluate TV ghost by using the system and vehicle. As the results, the useful data, which can be used to evaluate the effect of TV ghost interference from transmission lines could be obtained. In this paper, it is shown that the range of TV ghost interference from transmission lines can vary according to the frequency of TV electromagnetic wave, an incidence angle to the line and the other conditiions. At present, we are making efforts to establish a PDUR guideline for transmission lines.

• Journal of Forest and Environmental Science
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• v.28 no.2
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• pp.97-105
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• 2012

A Gangwon region consisting of over 80% of forest area has industries that have been developed by utilizing its clean region image. However, the recent climate change has increased the forest disease & insect pest as well as the forest fire and the major cause is known to be the increase in the frequency of a drought occurrence. From the aspect of climate change, it can be said that drought and forest are important in every aspect of the adaptation and mitigation of climate change measure as they increase forest disease & insect pest that leads to desolation of usable forest resource. In addition, the increase of forest fire reduces resources that can absorb greenhouse gas, which leads to increase in green house emission. The purpose of this study is to provide a motive for concentrating administrative power for protecting forest in a Gangwon region by selecting a drought management needed local government through a drought forecast according to the climate change scenario of a Gangwon region.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.348-353
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• 2006

Autonomous and intelligent resource model (AIR-model) defines a building-block of complex systems to pursue value creation by means of diverse resources, referred to as an AIR-unit, and presents a collaboration model with the AIR-units. An AIR-unit represents a piece of resources, such as machines, labor, raw materials, and other assets, considered individually by a complex system as means to accomplish given tasks. It is defined with its own service capability and a goal, and pursues achieving the goal by means of the capability. Moreover, an Air-unit is equipped with autonomy and intelligence, whereby it makes a decision on its course of action on its own initiative. Air-units collaborate on system operations with each other through goal-oriented negotiations. In this research, distinctive features of the AIR-model are addressed and described in detail. Principal components of the AIR-model are also designed via object-oriented modeling techniques. A prototype system based on the AIR-model is finally presented as an embodiment tool of a fractal manufacturing system (FrMS).

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.1702-1706
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• 2006

In the field of rice research, insertional mutants have become a valuable resource for studies of gene function. However, a well-designed database yet in the area of rice functional genomics. The relevant data are widely distributed and independently managed by the individual research groups. Heterogeneous data format in the distributed database systems causes many problems related to redundancy and compatibility. In this research, integration of the distributed databases using agent technology is pursued. In particular, a data integration agent, an ontology agent, a comparison agent, and resource agents are designed, whereby the integrated database is maintained. Moreover a framework for the web-based information system, which provides information to biologists and permits biologists to add new data to the database, is proposed. To establish an interoperable data format, an XML-based data model is also developed adopting ontology concept.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.4
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• pp.685-694
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• 2001

In this study, a transfemoral prosthesis system of which both stance phase and swing phase are controllable has been developed for the recovery of the biomechanical function of the amputated leg. It consists of a 5 bar link mechanism, a hydraulic-rubber knee damper for stance phase control and a pneumatic cylinder controlled via a microprocessor for stance phase control. The mechanical characteristics of the knee damper which absorbs the impact energy generated at the heel contact were investigated. The characteristics of the pneumatic cylinder essential for the speed adaptation of the prosthesis during swing phase were also studied for its mechanical characteristics. The prosthesis was subject to the clinical tests, and the gait characteristics obtained were very close to those of normal subjects. The stance and swing controlled prosthesis that were developed in this study showed good stability during the stance phase and showed good controllability during the swing phase.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.11 s.170
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• pp.1960-1969
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• 1999

This paper presents dynamic modeling and controller design of a tracked vehicle installed with the double rod type ERSU(electro-rheological suspension unit). A 16 degree-of-freedom model for the tracked vehicle is established by Lagrangian method followed by the formulation of a new sky-ground hook controller. This controller takes account for both the ride quality and the steering stability. The weighting parameter between the two performance requirements is adopted to adjust required performance characteristics with respect to the operation conditions such as road excitation. The parameter is appropriately determined by employing a fuzzy algorithm associated with the vehicle motion. Computer simulations are undertaken in order to demonstrate the effectiveness of the proposed control system. Acceleration values at the driver's seat are analyzed under bump road profile, while frequency responses of vertical acceleration are investigated under random road excitation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.11 s.170
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• pp.2087-2095
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• 1999

One of the main causes of unwanted dimensional changes in precision metal mold casting parts is excessive and irregular residual stresses induced by temperature gradients and plastic deformation in the solidifying shell. Residual stresses can also cause stress cracking, and lower the fatigue life and fracture strength of the casting parts. In the present study, aluminum alloy casting system with metal mold equipped with electrical heating elements and water cooling units was designed and the casting specimens were produced to quantify the effects of different cooling conditions on the development of residual stresses. The layer removal method was used to measure the biaxial residual stresses in casting specimens produced from the experiments. The experimental results agreed with Tien-Richmond's theoretical model for thermal stress development for the solidifying metal plate.

• Proceedings of the KWS Conference
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• 2003.11a
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• pp.18-20
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• 2003

Optimal processing and system to produce the laser welded tube for one body formed bumper beam are studied. The calculated size of tube is a thickness of 1.4mm, diameter of 105.4mm and length of 2000mm. The tube is shaped from cool rolled high strength steel sheet(tensile strength: 60kgf/$\textrm{mm}^2$ grade). Two roll bending method is the optimal tube shaping process compared to UO-bending, bending on press brake, multi-step continuous roll forming and 3 roll bending methods. Weld quality monitoring and seam tracking along the butt-joint lengthwise to the tube axis are also studied. The longitudinal butt-joint is welded by the $CO_2$ laser welding system equipped with a seam tracker and plasma sensor. The constructed $CO_2$ laser tube welding system can be used for the precision seam tracking and the real-time monitoring of weld quality. Finally, the obtained laser welded tube can be used for one-body formed automobile bumper beam.

• 한국벤처창업학회:학술대회논문집
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• 2008.04a
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• pp.253-301
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• 2008

본연구는 우리나라의 창업보육센터가 태동기, 양적 기반 확충기를 거쳐 이제 질적인 성장을 고려해야 할 성숙기의 단계에 접어들고 있는 시점에서 중소 벤처기업의 가장 어려운 난관인 Marketing 취약점을 제도적으로 지원함으로써 BI 입주기업의 성공을 도와 지역경제를 회생시키고 나아가 국가경제의 부흥을 도모할 필요가 있어 BI입주기업들을 대상으로 설문조사하여 분석 하였으며, 그 결과를 토대로 해결방안을 모색하였다. 조사 분석 결과 BI입주기업은 기술력과 사업성은 우수하나, 대외 인지도 및 마케팅능력 부족 등으로 매출신장은 미흡한 실정이고, 일부 BI 입주업체를 위한 마케팅 교육, 전시회 참가 및 홈페이지 제작 등을 지원하고 있으나, 그 성과는 극히 미홉하며, 기존 중소기업을 위한 판로지원 시책은 그 지원규모가 영세하고 또한, 기업의 성장단계 면에서 볼 때 초기 단계에 있는 BI입주기업이 이들 시책을 활용하기에는 애로가 있다. 경영자원의 부족에 따른 판매성과 미흡, 이에 따른 신규 경영자원 확보 실패와 계속적 판매 부진의 악순환을 탈피하기 어려울 것으로 판단되어진다. 이에 해결방안으로는 BI 입주기업에 대한 마케팅 지원을 활성화하기 위해서는 BI 입주기업만을 대상으로 하는 사업과 예산의 확보가 절대 필요하며 이를 시행함에 있어서는 수요자인 BI 입주기업이 필요로하는 서비스에 최우선을 두면서 소요 예산을 감안하는 것이 필요하다. 지원대상에 있어서는 BI 입주기업 전체를 지원하는 것은 예상되는 사업 비용상 불가능하며 차등적 지원을 통해 성공모델을 육성하는 것이 필요하리라고 전망된다.

• KCID journal
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• v.13 no.2
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• pp.236-245
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• 2006

Among a number of methodologies for developing groundwater supply to overcome drought events reported in the research community, an accurate estimation of the groundwater level is an important initial issue to provide an efficient method for operating groundwater. The primary objective of this paper is to develop an advanced prediction model for the groundwater level in the catchment area of the Ssangcheon groundwater dam using precipitation based period dividing algorithm and response surface methodology (RSM). A numerical example clearly shows that the proposed method can effectively forecast groundwater level in terms of correlation coefficient ($R^2$) in the upstream part of the Ssangcheon groundwater dam.