• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.434-441
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• 2003

This paper presents a generator for stand-alone vibration monitoring system of bridge structure based on ambient vibration of bridge. In this paper, a novel electric power generator which has minimum effect of armature reaction is proposed. The related mechanical and electrical design equations are obtained and a pilot generator has been implemented. In addition, the charging system for extremely low generator current is discussed, and some improvements are identified for the system. This investigation reveals that diode characteristics of rectifier is dominant factor in the charging process. Finally, both the simulation, which uses real measurement data of the Namhae bridge as input of the pilot generator, and indoor test are carried out. The results showed the applicability and effectiveness of the stand-alone vibration powered generator.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.103-108
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• 1998

This paper deals with stand-alone Photovoltaic system(SPVS) with charge and discharge controller. Main power source of SPVS are generally solar cell and battery. Therefore SPVS can be classified into variable types in accordance with connection type between battery and solar cell. Mainly used one of them is direct connection type which has advantages such as simple structure and simple controller. However most big drawback of this system is energy loss by voltage disharmony between solar cell and battery. Therefore SPVS with charge and discharge controller which can operate solar cell at maximum power point is designed and analyzed by simulation in this paper.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.308-311
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• 2006

A vibration monitoring is performed on a 1kW class stand alone wind turbine(W/T). When a W/T model is developed, general performance under various wind condition should be verified to introduce the product in the market. Especially, vibration characteristics within operating speed range are very important in the aspect of structural stability as well as generator's electrical efficiency. This paper examines the vibration performance of a home made 1kW W/T Various data of the W/T model are acquired in real time using a remote vibration monitoring system installed in Daekwanryung test site. Vibration stability of the W/T structure is diagnosed based upon the data and the result is used to estimate the applicability of the W/T model.

• Proceeding of KASS Symposium
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• 2008.05a
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• pp.212-217
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• 2008

This paper is concerned with the structural design of Angola Stadium. The Angola stadium is composed of a Steel moment frame system and a Cantilever steel truss roof. Whole structural analysis is necessary to ensure the stability. Considered FEM analysis, Design of Wind load & Seismic, Stand diaphragm, interaction between stand and Roof, Serviceability.

• Proceedings of the KIPE Conference
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• 2003.11a
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• pp.206-209
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• 2003

This paper deals with stand-alone PV power generation system with charge and discharge controller for the LED road sign. Main power source of PV system are generally solar cell and battery. Therefore PV system can be classified into variable types in accordance with connection type between battery and solar sell. Mainly used on of them is direct connection type which has advantage such as simple structure and simple controller. To verify the proposed PV generation system for the LED road sign, the detail simulation and experiment results indicate that operating characteristics are verified by experiment with a laboratory prototype in this paper.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1998.10a
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• pp.209-215
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• 1998

This paper deals with stand-alone Photovoltaic system(SPVS) with charge and discharge controller. Main power source of SPVS are generally solar cell and battery. therefore SPVS can be classified into variable types in accordance with connection type between battery and solar cell. Mainly used one of them is direct connection type which has advantages such as simple structure and simple controller. However most big drawback of this system is energy loss by voltage disharmony between solar cell and battery. Therefore SPVS with charge and discharge controller which can operate solar cell at maximum power point is designed and analyzed by simulation in this paper.

• The Korean Journal of Ecology
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• v.24 no.6
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• pp.385-394
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• 2001

An attempt to clarify the landscape structure of urban areas was carried out in the greenbelt around Seoul, Korea's metropolis. By means of aerial photographs and a field survey, a vegetation map including land-use pattern was made. Landscape structure was described by analyzing this vegetation map and the results of phytosociological survey. Landscape element types identified were (1) secondary forest, (2) plantation, (3) cultivated field, (4) urbanized area, (5) graveyard, and (6) bare rock. Vegetation units, resulting from the phytosociological analysis, included Quercus mongolica, Q. variabilis, Q. acutissima, Pinus densiflora, Q. aliena, and Alnus japonica communities. Plantations were composed of Robinia pseudoacacia, Populus tomentiglandulosa, P. rigida, Larix leptolepis, P. koraiensis, and Castanea crenata stands. Patches near to human settlements in the lower zones of the mountains were fragmented and small but they became larger towards the higher mountain zones. On the other hand, the number of patches was fewer and their size was larger in Mt. Cheonggye more distant from the principal residential area, larger in size, and higher in elevation compared with the other 2 mountains, Mt. Daemo and Mt. Acha. Floristic composition of Mongolian oak(Q. mongolica) stand distributing in the upper part of each mountain, in which artificial interference is rare, showed a difference among those study areas different in parent rock and disturbance regime. But that of black locust(R. pseudoacacia) stand located in lowland of mountainous area, in which artificial interference is frequent was similar to each other. As the results of analyses on the frequency distribution of diameter classes of major species, dominant landscape elements, Mongolian oak forest showed different responses depending on artificial interference as continuous maintenance and retrogressive succession in the sites far from and near to the residential areas, respectively. On the other hand, black locust stands showed a probability to be restore to the native oak forest through progressive succession.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10c
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• pp.268-270
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• 2002

오늘날 급속하게 발전하는 유전자 분석기술은 유전자 서열(sequence), 단백질의 기능(function) 및 구조(structure)정보와 같은 생명현상의 연구에 필수적인 정보들을 제공하게 되었다. 특히, 인간 유전체 프로젝트의 완성 이후 염기 및 단백질의 서열데이터를 이용하여 유사한 서열데이터의 검색 및 관련 단백질의 기능, 구조 정보들과 같은 생물정보의 종합적인 검색이 요구되고 있다. 하지만 기존 대부분의 통합서열분석시스템들은 단지 관련 정보를 포함하는 데이터 베이스들에 접근하며 서열유사성을 분석한 후, 그 결과를 단순히 디스플레이 하는 것이 대부분 이였다. 부연하면, 기존 통합 서열분석시스템들은 각 데이터베이스로부터 검색된 결과들 간의 명확한 관계를 설명하지 못하여 종합적인 생물정보를 제공하지 못하고 있다. 따라서 본 논문에서는 염기 및 단백질의 서열데이터로부터 서열유사성 검색 및 관련 단백질의 기능, 구조정보에 해당하는 종합적 인 생물정보를 효과적으로 검색, 서비스 할 수 있는 통합 서열분석시스템의 설계, 구현에 관해 기술한다.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.2
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• pp.101-109
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• 2003

The study area, Kwangneung Experiment Forest (KEF) is located on the west-central portion of Korean peninsula and belongs to a cool-temperate broadleaved forest Bone. At the old-growth deciduous forest near Soribong-peak (533.1 m) in KEF, we have established a 1 ha permanent plot ($100m{\times}100m$) and a flux tower, and the site was registered as a KLTER(Korean long-term ecological research network) and DK site of KoFlux. In this site, we made a stemmap of trees and analyzed forest stand structure and physical and chemical soil characteristics, and estimated carbon budgets by forest components (tree biomass, soils, litter and so on). Dominant tree species were Quercus serrata and Carpinus laxiflora, and accompanied by Q. aliena, Carpinus cordata, and so on. As a result of a field survey of the plot, density of the trees larger than 2 cm in DBH was 1,473 trees per ha, total biomass 261.2 tons/ha, and basal area $28.0m^2$/ha. Parent rock type is granite gneiss. Soil type is brown forest soil (alfisols in USDA system), and the depth is from 38 to 66 cm. Soil texture is loam or sandy loam, and its pH was f개m 4.2 to 5.0 in the surface layer, and from 4.8 to 5.2 in the subsurface layer. Seasonal changes in LAI were measured by hemispherical photography at the 1.2 m height, and the maximum was 3.65. And the spatial distributions of volumetric soil moisture contents and LAIs of the plot were measured. The carbon pool in living tree biomass including below ground biomass was 136 tons C/ha, and 5.6 tons C/ha is stored in the litter layer, and about 92.0 tons C/ha in the soil to the 30 cm in depth. Totally more than about 233.6 tons C/ha was stored in DK site. These ground survey and monitoring data will give some important parameters and validation data for the forest dynamics models or biogeochemical dynamics models to predict or interpolate spatially the changes in forest ecosystem structure and function.

• Journal of Korean Society of Forest Science
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• v.99 no.3
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• pp.312-322
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• 2010

In Korea, Torreya nucifera (L.) Siebold & Zuccarini is widely distributed in the warm temperate zone of South coastal area and Jeju island, mainly as preserved forest in the vicinity of the Buddhist temple and Confucian temple. The objective of this study is in order to develop the conservation method and comprehension of vegetation community by current vegetation structure analysis of Torreya nucifera stand. As the results, the number of surveyed species in Torreya nucifera stand were total 148 species with 28 species of tree layer, 38 species of subtree layer, and 82 species of shrub layer. The appearance of the common species were Ligustrum obtusifolium Siebold & Zucc., Hedera rhombea Bean, and Trachelospermum asiaticum Nakai var. asiaticum. All the story of the surveyed region, Torreya nucifera maintained the current dominant species, but the subtree layer and shrub layer was decreased dominant rate because of the development of the crown of tree layer and biased growth of the subtree layer. Most of the tree layer and subtree layer in Torreya nucifera stands are composed of the sprout forest. Therefore, these results suggest that in order to maintain the healthy stand it is demanded for the application of selection thinning method for reducing crown competition in Torreya nucifera forests.