• The Journal of the Korea Contents Association
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• v.12 no.7
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• pp.255-260
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• 2012

This study aims to examine the generation of scatter rays by dividing it into the presence of the subject at the chest X-ray examination, the X-ray tube and detector in the X-ray room, the front of the patient window, the outside of the entrance door of the patient waiting room, opening of the entrance door, the outside of the radiological technologist's entrance door, and the opening of the radiological technologist's entrance door, etc. When there is a subject, as the subject is thicker, more scatter rays occur at each of the spots for measurement. And when the entrance door is closed at the measurement, fewer scatter rays are generated.

• Proceedings of the Korea Water Resources Association Conference
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• 1998.05a
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• pp.32-37
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• 1998

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1520-1524
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• 2010

지상에 설치된 우량관측소를 통해서 자료가 수집되는 강우자료는 공간적으로 분포하고 있는 공간자료(spatial data)이며, 지점자료(point data)이다. 공간자료(spatial data)는 공간적으로 분포되지 않는 일반 데이터와는 다른 속성을 가지고 있으며 공간적인 위치가 데이터 발생의 중요한 변수로 적용될 수 있고, 인접 데이터와의 상관관계가 고려되어야 한다. 본 연구는 공간분석기법을 이용하여 보다 효과적인 강우분석을 하기 위한 것으로서, 우리나라 총 679개 우량관측소의 2008년 강우자료를 바탕으로 티센(Thiessen) 기법, IDW(Inverse Distance Weighted), 스플라인(Spline) 등과 공간통계학적 방법인 크리깅(Kriging)을 이용하여 주요 유역별 면적 강우량 산정 및 미계측 지역의 강우량 추정을 모의하였다. 본 연구결과 유역별 면적강우량 추정시 티센 및 경향면 분석법, Natural Neighbor 방법은 일부 과다 추정되는 것으로 나타났고, IDW, RBF, 크리깅의 방법은 큰 차이를 보이지 않았으나, 미계측 지역의 강우량 추정에는 일반크리깅의 정확도가 비교적 높은 것으로 나타났다.

• Spatial Information Research
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• v.10 no.3
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• pp.481-492
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• 2002

The severity and spatial Patterns of spring drought on the croplands arc investigated using satellite imagery(Landsat ETM+). It is necessary to analyze the area droughty conditions in order to decrease the damage and make the efficient policies. In this context, the information about soil moisture levels, which were fatal factors to the crop growth, was acquired from wetness calculated from Tasseled cap transformation. We confirmed that the wetness values have a strong correlation with NDVI and the principal components. The result showed that the intensity of vegetation covering the surface could be understood as the index of the impacts of drought on croplands and these relationships were effective to classify dry areas in satellite imagery.

• Economic and Environmental Geology
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• v.35 no.2
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• pp.163-170
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• 2002

The purpose of this study is to analyze the relationship between geology and geothermal gradient in South Korea using GIS. For the analysis, 352 temperature logging wells were constructed to spatial database and the relationships beween geothermal gradient and geological time and lithology were analyzed using the overlay the wells layer and 1:1,000,000 scale geological map layer. The average of the geothermal aradient of South Korea is 29.34$^{\circ}C$/km. In the geologic sequence, Cenozoic strata has 39.7$0^{\circ}C$/km, Mesozoic strata has 30.63$^{\circ}C$/km , Paleozoic strata has 22.32$^{\circ}C$/km, Proterozoic strata 23.15$^{\circ}C$/km geothermal gradient value. In the lithological aspect, plutonic rocks 33.96$^{\circ}C$/km, sedimentary rocks have 24.78$^{\circ}C$/km and sedimentary and volcanic rocks have 26.85$^{\circ}C$/km geotermal gradient value. The result can be used to develop geothermal energy and hot spring as a reference.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.413-415
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• 2022

Since human joints can be used as useful information for analyzing human behavior as a component of the human body, many studies have been conducted on human action recognition using joint information. However, it is a very complex problem to recognize human action that changes every moment using only each independent joint information. Therefore, an additional information extraction method to be used for learning and an algorithm that considers the current state based on the past state are needed. In this paper, we propose a human action recognition technique considering the positional relationship of connected joints and the change of the position of each joint over time. Using the pre-trained joint extraction model, position information of each joint is obtained, and bone information is extracted using the difference vector between the connected joints. In addition, a simplified neural network is constructed according to the two types of inputs, and spatio-temporal features are extracted by adding LSTM. As a result of the experiment using a dataset consisting of 9 behaviors, it was confirmed that when the action recognition accuracy was measured considering the temporal and spatial relationship features of each joint, it showed superior performance compared to the result using only single joint information.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.9
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• pp.56-65
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• 2005

A dynamic analysis method that freezes a time domain by discretization and solves the spatial propagation equation has a unique feature that provides a degree of freedom on spatial domain compared with the space discretization or space-time discretization finite element method. Using this feature, the time finite element analysis can be effectively applied to optimize the spatial characteristics of distributed type actuators. In this research, the time domain finite element method was used to discretize the model. A state variable vector was used in the discretization to include arbitrary initial conditions. A performance index was proposed on spatial domain to consider both potential and vibrational energy, so that the resulting shape of the distributed actuator was optimized for dynamic control of the structure. It is assumed that the structure satisfies the final rest condition using the realizable control scheme although the initial disturbance can affect the system response. Both equations on states and costates were derived based on the selected performance index and structural model. Ricatti matrix differential equations on state and costate variables were derived by the reconfiguration of the sub-matrices and application of time/space boundary conditions, and finally optimal actuator distribution was obtained. Numerical simulation results validated the proposed actuator shape optimization scheme.

• Spatial Information Research
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• v.20 no.2
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• pp.71-79
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• 2012

This paper is based on the research in the field of geospatial data that Seoul Government has initially promoted with private companies. In order to introduce the knowhow which has obtained through the cooperation between Seoul government and Private companies, several useful and practical materials will be offered in this paper. As for the cooperation on geospatial data, government and private companies should form a consultative group to find the way of improvement and the legal and regulatory details should be summited to related institutions. This paper will offer a proposal about how to improve and invigorate the present system, also, it will help to look for an effective proposal about budget reductions on the geospatial data which Seoul government propelled with private companies through continuous cooperation. Useful guide about how to solve the difficulties due to the imcomplete of legislations and closed institutions provided by Seoul Government will also be mentioned in this paper.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.165-166
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• 2015

본 논문에서는 제주풍력단지에 대한 측정 데이터(measured wind power outputs)를 기반으로 제주 실측 풍력데이터를 이용하여 공간적인 상관관계 분석을 수행하고, 상관관계 감쇠거리(CDD; Correlation Decay Distance)를 적용하여 새로운 풍력발전단지에 대한 공간모델 적용 시 기존 풍력발전단지의 포함여부(set 또는 subset)를 결정하는 기준(Threshold)으로 활용하고자 한다. 이를 통해 풍력발전출력 예측에 공간모델을 적용하고, 정확도를 향상시키는 방안을 연구하고자한다.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06c
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• pp.85-90
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• 2008

최근 유클리드 공간 상에서 효율적인 연속 k-최근접(k-Nearest Neighbors) 질의 처리를 위해 그리드 구조 기반의 많은 색인 기법들이 연구되었다. 하지만 기존 기법들은 k-최근접 객체들을 연산하기 위해 불필요한 셀을 접근하여 연산 자원을 낭비하거나 근접한 셀을 알아내는데 너무 큰 연산 비용을 초래한다. 그래서 본 논문에서는 한 셀과 주변 셀과의 거리 관계 패턴을 이용하여 k-최근접 질의 처리시 적은 연산비용과 적은 저장 공간을 사용하는 새로운 k-최근접 질의 처리 기법을 제안한다. 제안하는 기법은 k-최근접 질의 처리 시 거리 값을 기준으로 정렬된 거리 관계 패턴의 상대좌표를 순차적으로 적용하여 근접한 셀을 알아내기 때문에 O(n)의 셀 검색 비용이 요구된다. 또한 본 논문에서는 CPM[1]과 성능을 비교하여 제안하는 기법의 우수성을 입증한다.