• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.1
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• pp.58-60
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• 2015

In this letter, an open-loop precoding is proposed to enhance the performance of SM in transmit correlated MIMO channels. The proposed method is derived by observing the effect of feedback error on the minimum distance precoder, and can mitigate the performance degradation without any feedback information.

• Journal of Ocean Engineering and Technology
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• v.8 no.2
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• pp.47-55
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• 1994

The purpose of the present study is to investigate the effect of specimen thickness on statistical properties of crack growth resistance. In this study, the resistance S$\delta$$_h$(x) to fatigue crack growth was treated as a spatial stochastic process. which varies randomly on the crack surface. The theoretical autocorrelation functions of the resistance to fatigue crack growth considering specimen thickness are discussed for several correlation lengths. The main results obtained are : (1) The theoretical autocorrelation functions of S$\delta$$_h$(x) are almost independent of specimen of specimen thickness except for the origin. (2) The variance increases with decreasing specimen thickness.

• Korean Journal of Plant Resources
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• v.25 no.4
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• pp.407-415
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• 2012

Pinus pumila, which occurs in the northeast Asia, is found limitedly in Daecheongbong area of Mt. Seorak in the South Korea. This population was chosen to study spatial pattern, genetic diversity and spatial genetic structure. There were 48 polymorphic and 30 monomorphic I-SSR markers. A total of 65 individuals which distributed in the study site (40 m ${\times}$ 70 m) showed weakly aggregate distribution (Aggregate Index = 0.871). A total of 40 genets were observed from 65 individuals through I-SSR genotype comparison. Proportion of distinguishable genotype (G/N), genotype diversity (D) and genotype evenness (E) were 61.5%, 0.977 and 0.909, respectively. In spite of the small number and the limited distribution, Shannon's diversity index (I = 0.567) was relatively high as compared with those of other plant species. Spatial autocorrelation using Tanimoto's distance showed that the genetic patch was established within 12 m. Based on Mantel tests, there was relatively low correlation between genetic distance and geographic distance. Therefore, it seems the P. pumila population was formed by many parent trees in early stage. For ex situ genetic conservation of P. pumila, the sampling strategy is efficient at least above 12 m between individual trees.

• 한국지형공간정보학회:학술대회논문집
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• 2002.03a
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• pp.74-78
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• 2002

본 연구에서는 Greenland의 Sondrestrom 지역에 존재하는 빙하의 운동을 관측하기 위해 두 장의 ERS-1 SAR 영상을 이용한 SAU Interferometry(InSAR) 기법을 적용하였다. 본 연구에서 사용한 지역은 영상 좌편의 암석 지역과 영상 우편의 빙하 지역으로 구성되어 있기 때문에 복잡한 위상차를 보이며, 두 지역의 경계선 지역에서는 자료의 상관도(coherence)가 떨어지기 때문에 절대위상 복원(phase unwrapping) 수행시 시작점(seed point) 위치의 선정이 매우 중요한 사항이다. 또한 대상 지역에 대한 정확한 기준점의 확보가 어렵기 때문에 기선길이(baseline) 추정시 대상지역의 수치고도모형을 이용하여 많은 수의 기준점을 추출하여 기선길이를 추정하였다. 그 결과로 위성의 경사거리 방향에 대한 빙하의 속도 성분을 추출할 수 있었다.

• Journal of the Korean Geographical Society
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• v.35 no.5
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• pp.731-744
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• 2000

이 논문은 서울시 광고관련산업의 집적지 형성과정과 생산네트워크의 특성을 밝히고자 한다. 고차생산자서비스로서 광고관련산업의 서비스생산과정에서 관련업체와 생산네트워크가 중요한 기반임을 확인할 수 있었다. 인쇄광고관련업체와 방송광고관련업체의 집적지가 각각 도심의 충무로와 영동의 신사동지역에 형성되어 있었다. 이러한 집적지의 형성은 광고관련산업의 전반적인 유연적 전문화 과정과 연관이 있음을 알 수 있었으며, 관련 전문기능의 집적은 계속 강화되리라 예상된다. 광고회사는 주로 기획과 전략을 담당하고, 실제적인 제작 업무는 전무제작사들이 담당하는 공간적 분업과 생산의 네트워크화를 통해 광고하는 서비스가 생산되고 있었다. 그리고 각 집적지의 이득을 광고회사가 공간적 거리에 상관없이 충분히 활용하고 있었다. 결국 서울이라는 전체 공간이 함께 협력함으로써 서비스가 생산이 되는 모습을 보이고 있다. 이는 각 집적지내에서 관련 기능들이 서로 네트워크를 형성함으로써 네트워크의 이득을 활용하고 있으며, 또한 집적지 외부에 있는 기능이 공간적으로는 떨어져 있으나 다시 각 집적자와 네트워크를 형성함으로써 집적이득을 충분히 이용하는 국지적 집적효과가 아닌 지역적 집적효과를 활용하는 모습을 보이고 있었다.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.27-27
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• 2019

본 연구는 멸종위기 아고산수종 구상나무의 보존 복원을 위한 유전다양성을 고려한 표본추출전략을 구명하는데 그 목적이 있다. 2019년 9월에 한라산 영실 집단($14,000m^2$)에서 총 152개체를 대상으로 선발된 10개의 nSSR 마커를 이용하여 유전다양성 및 공간적 유전구조를 분석하였다. 평균 유전다양성은 관찰된 대립유전자수(A)가 7.2개, 유효대립유전자수($A_e$)가 3.6개, 이형접합도 관찰치($H_o$)가 0.528, 이형접합도 기대치($H_e$)가 0.595이며, 고정지수(F)는 0.071 이었다. 조사구내 구상나무 성목 152개체는 평균 수고 3.6 m, 흉고직경 17.3 cm로 나타났다. 구상나무의 개체목간 평균거리는 3.94 m, 임분밀도는 700 본/ha 이며 개체의 공간적 분포는 임의분포 형태로 나타났다. 구상나무의 유전변이에 대한 공간적 자기상관성(spatial autocorrelation) 분석 결과, 조사구의 구상나무는 약 15 m 이내에서 분포하는 개체들 간 유전적 유사성이 있게 분포하는 것으로 나타났으며 임분밀도가 높고 수고가 낮은 특성으로 인하여 비교적 작은 유전군락이 형성된 것으로 사료된다. 결과적으로 영실의 구상나무 집단의 보존 복원을 위한 표본추출전략은 15 m의 간격을 두고 개체를 선발하는 것이 타당한 것으로 나타났다.

• Journal of Korea Water Resources Association
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• v.51 no.7
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• pp.565-574
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• 2018

High population density in deltaic settings, especially in Asia, tends to increase and causes coastal flood risk because of lower elevations and significant subsidence. Large flood annually causes numerous deaths and huge economic losses. In this paper, an innovative technology of spatial satellite imagery has been used as tool to analyze the socio-economic flood-related damage in Mekong river basin. The relationship between nightlight intensity and flood damages has been determined for the period of 1992-2013 with a spatial resolution of 30 arc sec ($0.0083^{\circ}$), which is nearly one kilometer at the equator. Flow path distance was calculated to identify the distance of each cell to river network and to examine how nightlight intensity correlate to the area close to and far from river network. Statistical analysis results highlight the significant correlation between nocturnal luminosity intensity and flood-related damages in countries along the Mekong river (i.e., Cambodia, China, Lao PDR, Thailand, and Vietnam). This result reveals that the areas close to the river network correspond to high human distribution and causes huge damage during flooding. The result may provide key information to the region with respect to decisions, attentions, and mitigation strategies.

• The Journal of the Korea Contents Association
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• v.21 no.3
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• pp.590-601
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• 2021

The current study explored how robot's persuasive intent and its' physical distance affect consumers' evaluaton on the robot and the product that the robot advertises. This study administered a 2 (level of pursasion intent: low vs. high) × 2 (physical distance: normal vs. close) between-subjects factorial design experiment. The findings revealed that consumers evaluated the robot' expertise and trustworthiness more negatively and reported lower intentions to buy the produce when they perceived robot's persasive intent saliently high. Consumers were also found to show more negative attitude toward the robot and lower intentions to buy the produce when the robot approached to their personal space more closely. The theoretical and practical implications about human-robot interaction in marketing context were discussed.

• Korean Journal of Remote Sensing
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• v.37 no.6_1
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• pp.1647-1656
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• 2021

In order to reduce the spread of infection due to COVID-19, South Korea has established a four-step social distancing standard and implemented it by changing the steps based on the rate of confirmed cases. The implementation of social distancing brought about a change in the amount of activity of citizens by limiting social contact such as movement and gathering of people. One of the data that can intuitively confirm this is Night Time Light (NTL). NTL is a variable that can measure the size of the national economy measured using lights captured by satellites, and can be used to understand people's social activities during the night. The NTL visible data is obtained via the Visible Infrared Imaging Radiometer Suite (VIIRS) Day-Night Band (DNB) onboard the Suomi National Polar-orbiting Partnership (S-NPP) satellite. 1023 of Suomi data from 1 January 2019 until 26 October 2021 were collected to generate time series of NTL radiance change over Seoul to analyze the correlation with social distancing policy. The results show that implementing the level of social distancing generally decreased the NTL radiance both in spatial disparities and temporal patterns. The higher level of policy, limiting human activities combined with the low number of people who have been vaccinated and the closure of various facilities. Because of social distancing, the differences in human activities affected the nighttime light during the COVID-19 pandemic, especially in Seoul, South Korea. Therefore, this study can be used as a reference for the government in evaluating and improving policies related to efforts reducing the transmission of COVID-19.

• Journal of the Korean Geotechnical Society
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• v.20 no.7
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• pp.33-44
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• 2004

This paper is focused on the spatial variability of measured strong motion data during earthquake and its relationship with the performance of water distribution pipelines and residential buildings. Analyses of strong motion and the correlations of peak ground velocity (PGV) and pipeline and building damage were conducted with a very large geographical information system (GIS) database including the relationship of time and earthquake intensity and the measured location, and Kriging spatial statistics. Kriging was used to develop regressions of pipeline repair rate (RR) and residential building damage ratio (DR) associated with $90\%$ confidence peak ground velocity (PGV). Such regressions using Kriging provide an explicit means of characterizing the uncertainty embodied in the strong motion data compared with other spacial statistics such as inverse distance method.