• 한국수소및신에너지학회논문집
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• 제22권4호
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• pp.527-533
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• 2011

CNFs had been well addressed due to numerous promising applications in science and technology. Besides the same physicochemical properties of ordinary carbon materials such as active carbons and carbon black, they exhibit specific, e.g., tubular or fibrous structures, a large surface area, high electrical conductivity stability, as well as extremely high mechanical strengh and modulus, which make them a superior material for electrochemical capacitors. In this study, CNFs were pretreated by mechanical milling with different time in mortar and pestle. The milled CNFs were used as active material of electrode whose electrochemical property was tested to find physicochemical characterization variation. CNF electrode milled for 5 min has the highest electric capacitance. XPS spectrum were employed to explore changes in functional group induced from mechanical milling. Crystal size was calculated to analyze change of peak from different milling time by XRD. The CNF milled for 5 min has the largest crystal size and the highest electric capacitance.

• 한국산림과학회지
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• 제113권2호
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• pp.170-186
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• 2024

본 연구는 국가숲길로 지정된 DMZ펀치볼둘레길의 이용특성을 구명하고 지역경제에 미치는 파급효과를 추정하여 지속가능한 운영관리의 정책적 시사점을 제시하고자 실시되었다. 배포된 500개의 설문지 중에 215명의 응답자가 기본 설문문항을 포함하여 여행지 전체 일정과 지출한 금액을 작성하여 제출하였다. 분석결과 DMZ펀치볼둘레길은 주로 수도권에 사는 50대 이상이 가족과 3시간 30분을 이동하여 방문한 특성이 있었다. 주요 방문목적은 경관감상 활동을 중심으로한 휴양 및 휴식의 가벼운 여행 형태로 주로 오유밭길을 방문하여 4시간을 걸었다. 대부분의 방문객은 DMZ펀치볼둘레길 방문 전·후 강원도 지역을 방문하였으며, 양구군의 인근 관광지를 가장 많이 방문하였다. 1인당 평균지출액은 한국 도보 여행객의 평균지출 금액보다 높은 것으로 나타났다. DMZ펀치볼둘레길 방문으로 매년 평균 21억원(5년 평균 1만 명 이용객 기준)의 직접지출, 28억원 생산, 13억원 부가가치, 40명의 일자리를 강원도 지역내에서 창출하는 것으로 추정되었다. 본 연구 결과는 강원도 지역 경제에 큰 부문을 차지하고 있는 관광분야에서 국가숲길인 DMZ펀치볼둘레길이 차지하고 있는 구체적인 경제적 규모와 파급효과를 실증데이터를 통해 구명한 점에서 의의가 있다. 국가숲길 정책 추진의 타당성과 지속 가능한 산림이용을 위한 정책수립에 활용될 것으로 기대한다.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.95-102
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• 2003

• 복식문화학회:학술대회논문집
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• 복식문화학회 2003년도 International Exhibition and Workshop
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• pp.8-8
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• 2003

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1639-1642
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• 1997

In this paper, the autonomic function analysis system was designed to noninvasively assess the autonomic function of cardiovascular system. Orthostatic stress protocol was designed to stimulate the autonomic nervous system. designed protocol and analysis algorithm were evaluated by experiments for 25 normal subjects and 22 hemiplegia patients. Data were processed by usign the power spectral analysis. Nwe indexes of autonomic function, LF$_{N}$ and HF$_{N}$, were proposed and were compared with LF/HF ratio. New indexes of the sympathetic and parasympathetic activity, respectively. The IST and the DPT are balanced and have positive value for normal subjects during orthostatic stress but not for hempilegia patients. This result suggest that the IST and the DPT are used as new criteria of normal autonomic function during orthostatic stress.ess.

• Journal of Electrical Engineering and Technology
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• 제8권5호
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• pp.1096-1106
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• 2013

This paper presents the control of a Permanent Magnet Electric Variable Transmission (PM-EVT) for Hybrid Electric Vehicles (HEVs). Consisting of two electric machines, the EVT realizes the power split function in an electromagnetic way rather than in a mechanical way. A specific PM-EVT has been designed for Toyota Prius II. The control scheme of the entire vehicle is deduced using the Energetic Macroscopic Representation methodology. The energy management strategy yields local control references. A specific attention is paid for the field weakening for wide speed range. Simulation results are provided to illustrate the EVT modeling and control.

• 한국기록관리학회지
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• 제9권2호
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• pp.19-40
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• 2009

본 연구는 마이그레이션에 대한 개념 정리와 더불어 전자기록물 장기보존을 위한 다양한 마이그레이션 전략 및 DPT, CAMiLEON 등 주요 마이그레이션 전략 적용사례에 대한 조사분석을 통해 국내 전자기록물 장기보존전략으로서 마이그레이션을 적용하기 위해 고려해야 할 시사점들을 제안하였다.

• 동력기계공학회지
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• 제18권3호
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• pp.66-72
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• 2014

The local heat transfer and pressure drop of developed turbulent flows in the smooth convergent/divergent channels with rectangular and square cross-sectional areas along the axial distance have been investigated experimentally. The measurement was conducted within the range of Reynolds numbers from 15,000 to 89,000. The channel hydraulic diameter ratios of 0.67 and 1.49 in the rectangular channel with 2 inclined walls and the ratios 0.75 and 1.33 in the square channel with 4 inclined walls are considered. The comparison showed that among the four channels the square divergent channel has the highest thermal performance at the identical mass flow rate, at the identical pumping power, and at the static pressure drop.

• 한국세라믹학회지
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• 제30권11호
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• pp.925-932
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• 1993

The perovskite phase in PZN-PMN-PT (Pb(Zn, Mg)1/3Nb2/3O3-PbTiO3) pseudoternary ceramics was stabilized by the addition of excess constituent divalent oxides (PbO, MgO and ZnO). The excess addition of 5mol% MgO or 7.5mol% PbO fully stabilized the perovskite phase. The enhanced diffuse phase transition (DPT) and the decrease in the electrical resistivity observed in the presence of excess ZnO or MgO were interpreted in terms of the additional formation of negatively charged, short-range ordered 1:1 domains with a concomitant generation of charge carriers, holes.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2008년도 정보통신설비 학술대회
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• pp.249-252
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• 2008

This paper presents a new dynamically adaptable polling scheme for efficient support of real-time traffic over an IEEE 802.11 wireless LAN network. The poll scheduling plays an important role in IEEE 802.11 PCF. However, the current version of the polling list management scheme proposed in the IEEE802.11 standard is inefficient when a variable number of mobile stations have variable packets to transmit. If Point Coordinator has an exact information on the station status, it is possible to efficiently perform polling. In this thesis, we suggest an adaptable polling scheme to meet requirements of the stations. In our scheme, each station transmits packets including a piggyback information to inform that it wants to receive a poll in the next polling duration. Simulation results indicate that our scheme may reduces the packet discard ratio and real-time packet transfer delay.