• Communications for Statistical Applications and Methods
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• 제27권5호
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• pp.547-568
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• 2020

Modeling the statistical autocorrelations in spatial data is often achieved through the estimation of the variograms, where the selection of the appropriate valid variogram model, especially for small samples, is crucial for achieving precise spatial prediction results from kriging interpolations. To estimate such a variogram, we traditionally start by computing the empirical variogram (traditional Matheron or robust Cressie-Hawkins or kernel-based nonparametric approaches). In this article, we conduct numerical studies comparing the performance of these empirical variograms. In most situations, the nonparametric empirical variable nearest-neighbor (VNN) showed better performance than its competitors (Matheron, Cressie-Hawkins, and Nadaraya-Watson). The analysis of the spatial groundwater dataset used in this article suggests that the wave variogram model, with hole effect structure, fitted to the empirical VNN variogram is the most appropriate choice. This selected variogram is used with the ordinary kriging model to produce the predicted pollution map of the nitrate concentrations in groundwater dataset.

• Journal of Magnetics
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• 제8권1호
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• pp.50-59
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• 2003

Spatial light modulators (SLMs) are centrally important devices in volumetric recording, data Processing, Pattern recognition and other optical systems. Various types of reusable SLMs with two-dimensional pixel arrays have been intensively developed. Of these, magneto-optic spatial light modulators (MOSLMs) have advantages of high switching speed, robustness, nonvolatility, and radioactive resistance. In this article, we review recent development work on MOSLMs, mainly in relation to our own studies.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
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• pp.97-102
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• 2004

The very complicated proplem in spatial processing is effects of phading (Multipath and Delay Spread) and co-channel interference (CCI). The phading is one of principal causes, that form inter-symbol interference (ISI). Spatial-Temproral Adaptive Filter (STAF) has been taken as a solution of this problem, because it can suppress both these types of interference. But the performance of STAF exposes some elemental limitations, in which are the slow convergence of adaptive process and computational complexity. The cause of this is that, STAF must treat a large quantity of information in both space and time. The way that master these limitation is a use of Subband Spatial-Temproral Adaptive Filter (SSTAF). SSTAF reduce computational complexity by pruning off samples of signal and thus it lost some information in time. This draw on attennation of output SINR of SSTAF. The article analyse a optimal solution of this problem by introducing SSTAF with nonuniform weighted distribution.

• 농촌계획
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• 제11권3호
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• pp.11-17
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• 2005

Land prices reflect not only the uses of land, but the potential uses as well(Plantinga, 2002) so land values can be applied to very effective indices for deciding regional status and growing potential. The purpose of this study is to deduce determinant factors of regional land prices. Principal determinants of regional land prices are analyzed with a hedonic technique and spatial econometric models based on 2001 statistic data of Korea except large cities. The results provide the followings. 1. The spatial effect of rural regions are very little with adjacent regions. 2. The common index of land price is population density and other determinant factors are different depending on land uses.

• Geomechanics and Engineering
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• 제11권1호
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• pp.41-58
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• 2016

This paper focuses on the deformation behavior of tunnels crossing a weak zone in conventional tunneling. A three-dimensional finite element model was adopted that allows realistic modeling of the tunnel excavation and the support installation. Using the 3D FE model, a parametric study was conducted on a number of tunneling cases with emphasis on the spatial characteristics of the weak zone such as the strike and dip angle, and on the initial stress state. The results of the analyses were thoroughly examined so that the three-dimensional tunnel displacements at the tunnel crown and the sidewalls can be related to the spatial characteristic of the weak zone as well as the initial stress state. The results indicate that the effectiveness of the absolute displacement monitoring data as early warning indicators depends strongly on the spatial characteristics of the weak zone. It is also shown that proper interpretation of the absolute monitoring data can provide not only early warning for a weak zone outside the excavation area but also information on the orientation and the extent of the weak zone. Practical implications of the findings are discussed.

• 자원ㆍ환경경제연구
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• 제30권3호
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• pp.435-469
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• 2021

본 연구에서는 패널 공간더빈모형을 활용하여 유럽연합 회원국 26개 국가의 전력수출입 결정요인을 밝히는 것을 주요 목적으로 하며, 특히 전원별 발전량을 중심으로 설명하고자 한다. 이때 공간더빈모형을 활용함에 있어 단순히 인접기준 혹은 거리에 의해 가중치를 부여하는 방식이 아닌 전력 계통이 연계된 국가 간의 교역 비중을 기준으로 공간가중치 행렬을 구성하고자 한다. 또한 유럽 국가들의 전력계통은 직간접적으로 연결되어 지리적으로 멀리 떨어진 국가들 사이의 상호작용이 가능하므로, 이를 가중치행렬에 반영한다. 이를 바탕으로 분석한 결과, 원자력발전은 수출에는 양의 효과, 수입에는 음의 효과를 미치며 풍력·태양광 발전량의 증가는 전력의 계통 불안정성을 높여 수출과 수입에 모두 양의 효과를 미치는 것으로 분석되었다. 현재 국내의 지리적 여건상 타국과의 전력교역은 어려운 실정이다. 따라서 본 연구의 결과는 국내 에너지믹스 정책에 있어 시사하는 바가 있으며, 이전에 사용되지 않던 방식의 가중치행렬을 이용한 패널 공간더빈모형을 통해 전력수출입 요인을 분석했다는 데 의의가 있다.

• 한국실내디자인학회논문집
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• 제1호
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• pp.26-31
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• 1992

The purpose of this study was to determine the effect of a pleasantly designed interior inpro-spatial behavior. For pleasantly designed interior, the existing interior was remodeled through the change of finishing materials for major architectural elements such as wall, floor and ceiling, and changes of furniture and it's arrangement. Prospatial behavior was operationalized as seat arranging behavior and measured through the arranged condition and observable arranging behavior. Time-series design, one of quasi-experimental design was used. The data in this study were extracted from an existing field experimental research. One hundred forty four video tapes recorded during 6 months out of 2 years period ware used. In conclusion , the pro-spartial behavior change was a mid-term positive effect of pleasantly designed environment. In an environmental setting where pro-spatial behavior was most important, a certain time cycle to change the environment needs to be considered.

• Structural Engineering and Mechanics
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• 제54권1호
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• pp.121-133
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• 2015

The aluminum dome has been widely used in natatorium, oil storage tank, power plant, coal, as well as other industrial buildings and structures. However, few research has focused on the structural behavior and design method of this dome. At present, most designs of aluminum alloy domes have referred to theories and methods of steel spatial structures. However, aluminum domes and steel domes have many differences, such as elasticity moduli, roof structures, and joint rigidities, which make the design and analysis method of steel spatial structures not fully suitable for aluminum alloy dome structures. In this study, a stability analysis method, which can consider structural imperfection, member initial curvature, semi-rigid joint, and skin effect, was presented and used to study the stability behavior of aluminum dome structures. In addition, some meaningful conclusions were obtained, which could be used in future designs and analyses of aluminum domes.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.430-431
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• 2006

KOMPSAT-2 was successively launched on July 28,06. She carries Fine Spatial Resolution Sensor with three channels. It is 4m monochromatic and 1m panchromatic. The main purposes would derive fine urban map and digital elevation model(DEM).Therefore we extend to coastal environment monitoring using the adjacent effect of radiation due to an interaction of radiation between heterogeneous surface and atmosphere. With data analysis of ASTER on TERA, which is 15m resolution in visible and near infrared wavelengths, we found atmospheric aerosols were always large. Note that data analysis was limited in Nagoya bay, Lake Tahoe, California & La Pozuelos, La Picasa, Argentina. Thus this time we expect data analyses around isolated island and peninsula in west and south coast of Korea.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.179-183
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• 2000

This paper is concerned with achieving the high motion accuracy of linear motion bearing guide according to estimate accuracy average effect of bearing. Accuracy average effect can be obtained b analysis the relationship between motion error of the table and spatial frequency of the rail form error. And influences of ball diameter, ball number, and clock length on block motion error and block number on the table motion error are analyzed theoretically. In addition to, a simple experiment is performed in order to verify theoretical result.