• 한국시스템다이내믹스연구
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• 제16권1호
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• pp.5-23
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• 2015

The purpose of this study is to analyze the land-use changes in the coastal areas using system dynamics modeling and to provide directions for effective management to maintain coastal dune areas. This research process consists of four steps: First, we built the basic model based on the causal loop diagram which was analyzed the land-use change of Sindu-ri Coastal Dune. Second, a time series land-use change map using Arc Map was established. Third, the validity of the basic model was tested. Finally, three simulations were performed for the cut over area($100,000m^2/y$, $150,000m^2/y$, $200,000m^2/y$) of windbreak for maintaining the coastal dune areas. Simulation of the basic model showed that the area of the coastal dune will be consistently decreased. Based on the simulation, if windbreak were cut down $150,000m^2/y$, windbreak area will be restored to the target area in 2019. This study has the limitation which the simulation is progressed with a limited variable: area. Therefore, the modeling of coastal dune should be reflected various variables in the further study.

• 대한치과보철학회지
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• 제42권4호
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• pp.443-457
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• 2004

Purpose: The purpose of this study was to analyze and estimate whether each company may produce the color of artificial teeth as it stands, in the standard of vita classical shade guide using ShadeScan$^{TM}$ System. Material and methods: we chose the products of 6 companies -EFUCERA, IVOCLAR, ENDURA, TRUBYTE, DURADENT, and DURACROSS- estimated the shade value of each fixed point(cervical, body, and incisal area) of artificial tooth, and verified the equality among the samples from the same company. Results: First, the variation appeared significant at cervical and incisal area. It means that there were significant differences between cervical and incisal area although the most similar artificial teeth to the patients’natural teeth were provided. Second, the results in the body area showed that the variation between artificial and natural teeth was finite(p<0.05) in that area. Conclusion: it shows that the reproduction of colors of artificial teeth might be successful regarding the body is the most important part for a determination of the color of artificial teeth. However, more complements are necessary for the better reproduction of the color of artificial teeth between cervical and incisal area.

• 대한지리학회지
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• 제29권1호
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• pp.65-83
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• 1994

현행 행정구역체계의 기본골격은 조선시대와 일제초기에 만들어질 것으로 그간의 급속한 산업화와 도시화 및 교통, 통신의 발달에 제대로 상응하지 못하고 있다는 점에서 개 편의 필요성이 제기된다. 본 연구의 목적은 이러한 현행 행정구역체계의 가장 큰 문제점을 전체적으로 검토하고 그것의 합리적인 개편의 기본원칙과 방향을 모색하는 데 있다. 현행 행정구역체계의 가장 큰 문제점은 주민에 의해 자생적으로 형성된 실질적 공간체계와 관련 되어 있다는 것이다. 이러한 실질적 공간체계에 부합하기 위해서는 국토공간계획의 차원에 서 지역적 형평과 균형의 원리와 함께 중심도시와 배후지의 통합, 생활권의 계층체계와 행 정계층의 일치, 생활권의 범위와 행정구역의 일치 등을 원칙으로 한 행정구역개편이 이루어 져야 할 것이다.

• 전기학회논문지
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• 제59권6호
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• pp.1034-1040
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• 2010

This paper presents a calculation method of the area of severity for the stochastic assessment of voltage sags. In general, the annual expected numbers of voltage sags at an individual load point can be estimated stochastically. However, in order to assess the system voltage sag performance considering many sensitive load points together, it is necessary to determine and analysis the area of severity for the load points. The area of severity to voltage sags is the network region where the fault occurrences will simultaneously lead to voltage sags at different load points. In this paper, the concept of the voltage sag assessment and the calculation method of the area of severity are addressed. The analysis of the area of severity is performed on the IEEE 30-bus test system by using the proposed method. The method is useful for the stochastic assesment of voltage sags and the establishment of systematic plans for voltage sag mitigation.

• 한국환경과학회지
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• 제13권1호
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• pp.19-26
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• 2004

The purpose of the study was to construct a forecast system of flood inundation area at natural stream channels. The study built the system to interpret the flood inundation area in four stages ; constructing topography data around the stream channel, interpreting flood discharge, interpreting flood elevation in the stream channel, and interpreting the flood inundation and mapping. According to the result of the analysis, as for the characteristic of flood inundation around the area within the purview of this study, although there were areas where flood inundation over a bank caused a flooded area, the failure of the internal drainage in the ground lower than flood elevation caused more serious problems. Rather than the existing method where only the estimated flood elevation data is used based on the hydrographical stream channel trace model(such as the HEC-RAS model) to establish the flood inundation area, if the procedure introduced in this study was applied to interpret the floodplain, actual flood inundation area could be visibly confirmed.

• 한국항공운항학회지
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• 제24권2호
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• pp.74-80
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• 2016

Development of air navigation and avionics technologies led to solve the problems that conventional ATM system had. The International Civil Aviation Organization developed the Aviation System Block Upgrades (ASBU) initiative in order to harmonize global ATM planning and technology upgrades and urged to implement the recommendations for the member States. The ASBUs provide the road map to assist air navigation service providers in the development of their individual strategic plans and investment decisions. In this paper, the operational concepts in 2 performance improvement areas, Airport Operations and Globally Interoperable System and Data in ASBUs, have been summarized. In Airport Operations area the new management technologies and required systems are presented for optimizing the traffic flow in airport area and terminal airspace. Data format standards and required systems presented for information integration and usage of the new system under Globally Interoperable System and Data area.

• 한국소음진동공학회논문집
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• 제23권2호
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• pp.105-111
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• 2013

Whirl tower test is conducted basically during helicopter rotor system development process. And for whirl tower test of rotor hub system, new design blade or existing blade which is remodeled for new rotor hub system is used. Because of simple shape and efficient aerodynamic characteristic, BO-105 helicopter blade is used for helicopter rotor hub development project widely. Originally BO-105 blade is used for hingeless hub system and blade root is used to flexure. So flap stiffness and lag stiffness at blade root area is relatively low compare with airfoil area. So, in order to apply the BO-105 blade to bearingless hub, blade root area have to be reinforced. And in this process, blade root area's section property is changed. In this paper, we suggest reinforcement method of BO-105 blade root area and study dynamic characteristic of bearingless rotor system with reinforcement BO-105 blade.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.200.1-200.1
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• 2011

Underground air is a special energy source in Jeju and distributes lava cave, pyroclastic, open joint, and crushing zone. A possible area to utilize underground air is 85% of Jeju except to the nearby area of Sambang Mt. and 25m high coastal area from sea level. In Jeju, underground air is used for heating agricultural facilities such as greenhouse cultivated mangos, Hallbong and mandarin orange, pigsty, mushroom cultivation house, etc. and fertilizing natural $CO_2$ gas by suppling directly into agricultural facilities. But this heating method causes several problem because the underground air has over 90% relative humidity and is inadequate in heating for crops. Mangos are the most widely grown tropical fruit trees and have been cultivated since 1993 in Jeju. In Jeju, the cultivating area is about 20ha and amount of harvest is 275ton/year in 2010. In this study, the heat pump system using underground air as heat source was installed in mangos greenhouse which area is $495m^2$. The capacity of heat pump system and heat storage tank was 10RT, 5ton respectively and heating effect and heating performance of the system were analysed.

• 한국항만학회지
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• 제11권2호
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• pp.157-172
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• 1997

To develop the port productivity and effictiveness, the introduction of the On Dock Operating System in Pusan Container Terminals has to be considered and the present Off Dock CY be closed step by step. This work aims to evaluate the needed CY area in Pusan Port under the On Dock Operating System. This researching flow is as follows. Firstly, estimate total sea-borne container cargo volumes in Korea and distribute them to all container terminals according to the past trends and the planned port development. Secondly, estimate the average period and the average tiers stored at On Dock CY in case of On Dock Operating System. Thirdly caculate the needed CY Area to handle the distributed container cargo volume under the On Dock Operating System. Finally, the following results are obtained. (1) In 1998, opening the Gamman Terminal, 827 thousands cubic meters are insufficient. (2) In $2001\sim2004$, the insufficiency of needed CY Area will be maximized and estimated to be 936 thousands cubic meters in 2001. (3) In $2005\sim2011$, opening the Gadu Terminal, the insufficiency of needed CY Area will be decreased and estimated to be 240 thousands cubic meters in 2011.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 1998년도 가을 학술발표논문집 Vol.25 No.2 (3)
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• pp.83-85
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• 1998

컴퓨터 하드웨어 기술의 발달은 물론 고속 통신 기술의 발달로 컴퓨터의 사용분야가 단순 계산에서 멀티미디어를 사용하는 VOD 서버 기술을 필요로 하게 되고 경제적이면 효율적으로 멀티미디어 데이터를 다루는 기술이 요구되면서 서버의 확장성과 원활한 데이터 서비스가 필요하게 되었다. 이에 본 논문에서는 초고속 통신망에 기반한 SAN(System Area Network)에 기반한 클러스터링 시스템을 제안하여 최대한 대역폭을 이용한 병렬 I/O를 통하여 SAN 상에 입출력 성능의 개선할 수 있는 Scalable VOD 서버를 제안하여 구현 성능 평가 하혀 한다.