• Atmosphere
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• v.14 no.3
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• pp.19-28
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• 2004

In this study, two years Automatic Weather Station (AWS) data observed near the coast and islands are used to evaluate gust factors only when time averaged wind speed is higher than 5 ms. The gust factors are quite different in spatial and temporal domain according to analysis method. As the averaged time is increased, the gust factors are also increased. But the gust factors are decreased when wind speed is increased. It is because each wind speed is averaged one and a maximum wind is the greatest one for each time interval. The result from t-test is shown that all data are included within the 99% significance level. A sample standard deviation of ten minutes and one minute are 0.137~0.197, 0.067~0.142, respectively. Recently, the gust factor provided at the Korea Meteorological Administration (KMA) Homepage is calculated with one-hour averaged method. All though this method is hard to use directly for forecasting the strong wind over sea and coast, the result will be a great help to express Ocean Storm Flash in the Regional Meteorological Offices and the Meteorological Stations.

• KIEAE Journal
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• v.5 no.1
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• pp.27-33
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• 2005

Global efforts have made to reduce energy consumption and $CO_2$ gas emission. One of the weakest parts for energy loss through the whole building components is building envelopes. Lots of technologies to increase the thermal performance of building envelopes have been introduced in recent year. Transparent Insulation Wall(TIW) is a new technology for building insulation and has been function both solar transmittance and thermal insulation. A mathematical model of a Transparent Insulation Wall equipped with south wall was proposed in order to predict thermal performance under varying climates(summer and winter). Unsteady state heat transfer equations were set up using an energy balance equation and solved using Gauss-Seidel iteration solution procedure. The thermal performance of the TIW determined from a wall surface and air layer temperature, non-airconditioned room temperature and air conditioning load. As a result, this numerical study shows that the TIW is effective in an air conditioning load reduction. Further experimental study is required to establish complete TIW system.

• Journal of the Korean Solar Energy Society
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• v.32 no.3
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• pp.96-103
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• 2012

Annual energy consumption in detached houses are affected mainly by thermal performance of envelope. In particular the performance of glasses are critical due to global wanning and climatic change. Therefore, this research analyzes annual consumption of cooling and heating energy with various combination of U-value, shading coefficient and building orientation. The simulation results shows that shading coefficient of glazing contributes to the changes of proportion of heating and cooling energy demand and the optimized shading coefficient for minimizing energy consumption varies with buildings orientation.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11b
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• pp.899-902
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• 2003

무선 환경에서의 실시간 서비스의 확대와 노드의 이동성 증가에 따라 handover 시 발생되는 패킷 손실과 지연으로 인한 실시간 서비스의 중단이 해결해야 할 중요한 문제점이 되고 있다. 본 논문에서는 IETF (Internet Engineering Task Force)의 중요한 마이크로 이동성 프로토콜인 HMIPv6의 기본 동작을 설명하고, 여전히 문제점으로 남아있는 Inter-MAP (Mobility Anchor Point) handover의 성능을 향상시키기 위한 Dynamic MAP Switching handover 알고리듬을 제안한다. 제안한 알고리듬은 인접한 MAP 도메인을 중첩되게 설정하고 Inter-MAP handover가 발생되기 전에 미리 MAP을 switching한다. 따라서 Inter-MAP handover가 발생하지 않도록 함으로써 handover 시 발생하는 데이터의 손실 및 지연을 감소시킬 수 있다. 제안된 알고리듬의 성능 향상은 산술적 분석을 통하여 검증한다.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.229-234
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• 2005

This study aims to build basic data for a optimization of a ventilation system for indoor environment improvement in school building. To this end, we conducted field tests and computation fluid dynamics simulations about a indoor environment in dependence on operation of a ceiling type inverter air conditioner and ventilation system. The results could be summarized as follows. (1) For the ventilation system of 350CMH, 500CMH and 850CMH, reduction of each $CO_2$ concentration was measured 662ppm, 748ppm and 526ppm. (2) A optimal discharge angle of the ceiling type inverter air conditioner system was evaluated 45 degree in heating and cooling.

• Proceedings of the SAREK Conference
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• 2004.06a
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• pp.127-127
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• 2004

• Journal of The Korean Radiological Technologist Association
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• v.29 no.1
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• pp.31-34
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• 2003

Purpose : To evaluate technical feasibility and clinical usefulness of CT fluoroscopy (CTF) guided PTBD immediately after CT scanning in ER Patients with obstructive jaundice. Materials and Method : ER patients diagnose4 as obstructive jaundice through cl

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.2
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• pp.244-249
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• 1999

This study is to examine the emission rate of $CO_2$gas as the environmental load in office buildings. After the investigation of monthly consumption of each energy source(electricity and natural gas), it is analyzed that the $CO_2$emission rate of 34 office buildings surveyed is 22.4kg-$c/m^2$.year, which consists of 17.5kg-$c/m^2$.year by consuming electricity, and 4.9kg-$c/m^2$.year by consuming natural gas. And the $CO_2$emission rate of each load in those buildings consists of 68% emitted by general electricity, 16% by cooling load and 16% by heating load. It is also proposed that the $CO_2$emission rate of cooling and heating load is profoundly pertinent to the variation of outdoor temperature.

• Journal of the Korean Solar Energy Society
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• v.21 no.1
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• pp.51-60
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• 2001

Underground space gives two benifits to us. First, it helps us to solve the land scarcity problem in urban city. Second it also helps us to manage the thermal properties of underground to keep cool in summer and warm in winter. How much it save energy depends on the ability to predict the exact temperature of the space. The purpose of this paper is to make a function predicting the temperature of underground space, analysing the 20 years measures of underground temperature kept in Korea Central Weather Burea.

• Solar Energy
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• v.18 no.4
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• pp.95-100
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• 1998

Indoor environment of the classrooms in most school buildings have not been maintained comfortably during the heating and cooling seasons due to the insufficient installation of the heating and cooling systems and their operation in our country. This study aimed to suggest the guideline for installing the appropriate heating systems to make a better environment of the classrooms in the elementary school buildings. Field survey and the computer simulation of the model school were carried out, and the cost of the both installation and operation were compared with different heating systems.