• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.90.1-90.1
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• 2012

Galaxy clusters, the largest gravitationally bound system, are important means to place constraints on cosmological model and to study the evolution and the formation of galaxies and their large scale distribution. We will report results from our study of galaxy clusters in the European Large Area ISO Survey North1/North2(ELAIS-N1/N2) fields, covering a total of 10.8 $deg^2$. We combine multiple wavelength data from IMS survey, UKIRT Infrared Deep Survey-Deep Extragalactic Survey (UKIDSS-DXS, JK bands), Spitzer Wise-area InfraRed Extragalactic survey (SWIRE, Optical-Infrared bands), and CFHT (u,g,r,i,z bands.) The photometric redshifts are derived from these datasets and are used to search for high redshift galaxy clusters at 0.8 < z < 1.5.

• IE interfaces
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• v.19 no.4
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• pp.333-341
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• 2006

RFID (Radio Frequency Identification) is a technology that can input identification information to microchip and make goods, animals, persons recognized, chased, and managed using radio frequency, and is founded on the core technology of ubiquitous environment of the future. In this paper, we propose a RFID integrated system designed to manage the lifecycle of an individual product efficiently. The proposed system can enable traceability and visibility of items through their entire life by integrating distribution and banking information on the basis of EPCglobal Network. It may provide the infra of Digital Manufacturing and RTE (Real Time Enterprise) and effective information sharing structure with existing legacy system (ERP, CRM, SCM) by real time.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1174-1176
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• 1993

Morphology of low density polyethylene(LDPE) such as the degree of crystallinity changes with thermal history etc. In order to clarify the effects of morphological changes on electrical breakdown, we studied direct current and impulse breakdown phenomena of LDPE films heat-treated at 100[$^{\circ}C$] for 1[H] in silicone oil and subsequently cooling to various ways. The degree of crystallinity was estimated by the infra red absorption and X-ray diffraction measurements for the specimens of slowly cooled, cooled in water, original, and cooled in liquid nitrogen gas. As the result, we obtained that the first, second, third, and fourth was slowly cooled of 70.23[%], cooled in water of 61.6[%], original specimen of 56.75[%], and cooled in liquid nitrogen gas of 34.7[%] respectively. The crystalline size and distribution of specimens were researched by Differential scanning calolimeter measurements.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.1075-1078
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• 2011

최근 단순한 이동수단의 목적인 자동차에서 IT기술을 접목시킨 스마트 자동차로의 패러다임 변환을 시도하고 있다. 이러한 ITS(Intelligent Transportation System)기반 스마트 자동차에는 기본적으로 차량 통신 네트워크 기술인 V2X(Vehicle-to-Infra/Vehicle/Nomadic)가 통신기술부분으로 이용되고 있다. V2X는 차량과 차량, 인프라, 모바일간의 통신을 도로차량에 적용한 모든 형태의 통신방식을 지칭하는 용어를 의미한다. 이러한 V2X 통신기술을 사용하기 위해서는 각 통신기술마다 주파수가 필요하며 ITU-R에서는 관련 주파수를 권고하고 있다. 하지만 국내 ITS 서비스용으로 할당된 주파수가 ITU-R의 권고사항 및 국외 현황과 상이하여 국내 차량 간 통신 기술 표준화가 보류 상태에 있으며 기술개발이 늦어지고 있는 상황이다. 본 논문에서는 국내외 ITS 주파수 할당 현황을 비교하였고, 해외 ITS 산업 동향 및 기술개발동향에 대해서도 살펴보았다. 본 연구 결과는 국내 ITS 주파수 재분배 혹은 추가 할당에 대한 정책 결정시 참고가 될 수 있을 것이다.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.2
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• pp.109-118
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• 2011

The aims of this study were analyze the amount of stress condition when the traction force was applied to the condyle head from the chin area of mandible and amount of distortion condition when intended 0.5 mm distraction distance from surface or one point of dissected midline of mandible. For this study, 3D finite element analysis were performed. The following results were obtained : 1. When traction force of 500 g was applied to the condyle head from the chin area, condylar neck area showed the greatest amount of stress and coronoid process was the least amount of stress area. For the amount of distortion condition, infra dental area showed the greatest. 2. When 0.5 mm of intended surface distortion was applied after dissection of mid-mandible area, base anterior area showed the greatest amount of stress but the least stress area was coronoid process. For the amount of distortion, infra dental, menton area showed the greatest amount. 3. One point distortion was applied after dissection of mid-mandible area, ramus posterior area showed the greatest amount of stress and menton area were the least stress condition. For the amount of distortion, menton area showed the greatest amount of distortion condition.

• Journal of the Korean Geographical Society
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• v.38 no.3
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• pp.375-388
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• 2003

This study mainly focuses on evaluating how the triangular training operator could improve classification accuracy in SAR(Synthetic Aperture Radar) and VIR FCC(Visible Infra-red, False Colour Composite). The techniques for the determination of the most informative SAR/VIR combinations in the triangular space diagram, as developed tv the author of the paper, are given and the results obtained are presented. The SAR alone, VIR alone and SAR/VIR FCC classification showed trends for gradual improvement of accuracy. Accuracy distribution pattern for individual classes could be explained closely related to SAR/VIR signature components in the process of the triangular synergistic training. Due to contribution of SAR signature in training samples, it was possible to isolate major terrain features such as cloud cover area and roughness target with acceptable spatial precision. It is anticipated that this research output could be used as a valuable reference for distribution trends of classification accuracy obtained by triangular channel space based training in synergistic application.

• Journal of Korea Water Resources Association
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• v.54 no.8
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• pp.607-616
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• 2021

The purpose of this study is to simulate the transport of nonuniform sediment considering the hiding-exposure effect numerically. In order to calculate the transport of multi-disperse suspended sediment mixtures, the set of advection-diffusion equations for each particle class is solved. The applicability of the numerical model is examined by comparing the simulation results with experimental data. In this study, we calculate the vertical distribution of total concentration of sediment particles using two approaches: (1) by considering the mixture as represented by a single size; and (2) by combining the concentration of the sediment corresponding to several particle size classes; From the simulation results, it is shown that both approaches calculate reasonable results due to the narrow range of size distribution. Under the condition of nonuniform sediment, the critical shear stress of the sediment particle is influenced by the size-selective entrainment, i.e., hiding-exposure effect. It is shown in this study that the effect of hiding-exposure effect on the erosion rates of fine sand is negligibly small.

• Korean Journal of Remote Sensing
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• v.30 no.2
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• pp.275-292
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• 2014

The objective of this study is to determine Tasseled Cap Transformation (TCT) coefficients for the Geostationary Ocean Color Imager (GOCI). TCT is traditional method of analyzing the characteristics of the land area from multi spectral sensor data. TCT coefficients for a new sensor must be estimated individually because of different sensor characteristics of each sensor. Although the primary objective of the GOCI is for ocean color study, one half of the scene covers land area with typical land observing channels in Visible-Near InfraRed (VNIR). The GOCI has a unique capability to acquire eight scenes per day. This advantage of high temporal resolution can be utilized for detecting daily variation of land surface. The GOCI TCT offers a great potential for application in near-real time analysis and interpretation of land cover characteristics. TCT generally represents information of "Brightness", "Greenness" and "Wetness". However, in the case of the GOCI is not able to provide "Wetness" due to lack of ShortWave InfraRed (SWIR) band. To maximize the utilization of high temporal resolution, "Wetness" should be provided. In order to obtain "Wetness", the linear regression method was used to align the GOCI Principal Component Analysis (PCA) space with the MODIS TCT space. The GOCI TCT coefficients obtained by this method have different values according to observation time due to the characteristics of geostationary earth orbit. To examine these differences, the correlation between the GOCI TCT and the MODIS TCT were compared. As a result, while the GOCI TCT coefficients of "Brightness" and "Greenness" were selected at 4h, the GOCI TCT coefficient of "Wetness" was selected at 2h. To assess the adequacy of the resulting GOCI TCT coefficients, the GOCI TCT data were compared to the MODIS TCT image and several land parameters. The land cover classification of the GOCI TCT image was expressed more precisely than the MODIS TCT image. The distribution of land cover classification of the GOCI TCT space showed meaningful results. Also, "Brightness", "Greenness", and "Wetness" of the GOCI TCT data showed a relatively high correlation with Albedo ($R^2$ = 0.75), Normalized Difference Vegetation Index (NDVI) ($R^2$ = 0.97), and Normalized Difference Moisture Index (NDMI) ($R^2$ = 0.77), respectively. These results indicate the suitability of the GOCI TCT coefficients.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.8B
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• pp.667-680
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• 2008

In this work, we present the results of our empirical study on 802.11 wireless LAN network traffic. We collect the packet trace from existing campus wireless LAN infra-structure. We analyzed four different data sets: aggregate traffic, upstream traffic, downstream traffic, tcp only packet trace from aggregate traffic. We analyze the time series aspect of underlying traffic (byte count process and packet count process), marginal distribution of time series, and packet size distribution. We found that in all four data sets there exist long-range dependent property in byte count and packet count process. Inter-arrival distribution is well fitted with Pareto distribution. Upstream traffic, i.e. from the user to Internet, exhibits significant difference in its packet size distribution from the rests. Average packet size of upstream traffic is 151.7 byte while average packet size of the rest of the data sets are all greater than 260 bytes. Packets with full data payloads constitutes 3% and 10% in upstream traffic and the downstream traffic, respectively. Despite the significant difference in packet size distribution, all four data sets have similar Hurst values. The Hurst alone does not properly explain the stochastic characteristics of the underlying traffic. We model the underlying traffic using fractional-ARIMA (FARIMA) and fractional Gaussian Noise (FGN). While the fractional Gaussian Noise based method is computationally more efficient, FARIMA exhibits superior performance in accurately modeling the underlying traffic.

• International Journal of Quality Innovation
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• v.9 no.2
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• pp.129-147
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• 2008

This research is to investigate the effect of the improvement of investment environments with investment incentive on Korean national economy by looking into the foreign investment support system in Korea. To this end, first research model was set up based on our literary study and case study was conducted on 150 foreign companies that were located in industrial complex for foreign companies, received the tax benefit and government subsidization. And it was found that even though the foreign companies were contributing to the national economy in general such as in the area of production, export, employment, development of technology, there was no significant contributory difference between the investment incentive beneficiary and non-beneficiary foreign companies. Therefore it deemed reasonable to reconsider the way Korean government supports foreign companies in Korea and to reinforce foreign companies' relevance to national policy agenda with additional incentives to foreign companies located in comparatively less developed areas. As a way to promote foreign investment, promotion of investment infra such as improvement of follow-up services, openness to foreign investment, industrial deregulations in capital area, revitalization of free economic zone, efficient system to promote foreign investment and the reinforcement of public relations were considered necessary, especially the upgrading of economic structure and the integrated management of domestic and foreign investors deemed necessary for the optimal distribution of the industries.