• Journal of Korea Water Resources Association
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• v.42 no.3
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• pp.247-257
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• 2009

In this study, a distributed rainfall-runoff model is developed using a multi-directional flow allocation algorithm and the real-time runoff updating algorithm. The developed model consists of relatively simple governing equations of hydrologic processes in order to apply developed algorithms and to enhance the efficiency of computational time which is drawback of distributed model application. The variability of topographic characteristics and flow direction according to various spatial resolution were analyzed using DEM(Digital Elevation Model) data. As a preliminary process using fine resolution DEM data, a multi-directional flow allocation algorithm was developed to maintain detail flow information in distributed rainfall-runoff simulation which has strong advantage in computation efficiency and accuracy. Also, a real-time updating algorithm was developed to update current watershed condition. The developed model is able to hold the information of actual behavior of runoff process in low resolution simulation. Therefore it is expected the improvement of forecasting accuracy and computational efficiency.

• Journal of the Society of Disaster Information
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• v.18 no.1
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• pp.51-62
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• 2022

Purpose: This study analyzes accessibility of outdoor evacuation places for earthquake and the accessibility improvement effects when expanding the evacuation places in accessibility-deficient areas. In order to consider real-world evacuees, the accessibility analysis is based on service population not on resident population. Method: Location-allocation model as a GIS-based spatial optimization mode is used to analyze accessibility and vulnerable areas to evacuation places. Of location-allocation problem types, 'Maximize Coverage' method is chosen to allocate as many potential evacuees as possible to evacuation places. And impedence cutoffs or evacuation distances (times) are applied to three classes: 500m (7.5 minutes), 1,000m (15 minutes), and 1,500m (22.5 minutes). Case study area is Jung-gu areas, Seoul as a high-density downtown area. Result: Results show that accessibility-deficient areas and population to evacuation places are much more in service population than in resident population. Accessibility is significantly improved when increases when expanding the evacuation places in accessibility-deficient areas. Yet, accessibility-deficient areas are still remained since available lands are insufficient in the high-density downtown area. Conclusion: The study suggests that temporary evacuation facilities like outdoor evacuation places for earthquake need to consider real potential evacuees based not only on resident population but also on service population. Also, policy measures to provide emergency shelters need to more utilize spatial optimization tools like location-allocation model.

• Science of Emotion and Sensibility
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• v.23 no.2
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• pp.35-50
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• 2020

This study aimed to investigate the changes of emotional perception biases according to the level of social phobia and the relationship with visuospatial attention allocation ability. This study used the Korean self-report assessment test (Korean version of social avoidance and distress, K-SAD) to measure the level of social phobia. Moreover, the emotional perception and useful field of view (UFOV) tasks were employed for measuring emotional perception biases and visuospatial attention allocation ability, respectively. A total of 118 participants participated in this experiment, and only 107 (males: 94, females: 13) data were analyzed due to the exclusion of response errors and other statistical problems. The average age of the participants used in the analysis was 21 years (SD: 3.64), and those participants were divided into three groups according to the K-SAD scores. Consequently, all experimental groups showed negative emotional perception biases in the emotional perception task, but the magnitudes of the biases of each group were not significantly different. Furthermore, the positive emotional perception biases were higher at higher levels of social phobia, which could be related to the tendency of interpreting positive stimuli negatively. In the UFOV task, the higher the level of social phobia, the lower the visuospatial attention allocation ability. These results suggest that the deterioration of visuospatial attention allocation ability potentially contributes to the increase of positive emotional perception biases by being difficult to perceive external stimuli. Thus, this paper discusses the potential contribution of visuospatial attention allocation ability to the increased perceptual biases of positive emotions as the level of social phobia increases.

• Proceedings of the Korea Multimedia Society Conference
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• 2001.11a
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• pp.6-11
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• 2001

본 논문에서는 서로 다른 공간해 상도를 갖는 두계층 영상부호화대서 하위계층에는 낮은 우선순위로 인하여 제한된 일정부호화율로 부호화하고, 반면에 각 영상의 상위계층에는 우선순위를 높게 하면서 서로간 균등한 화질을 제공하는 대역할당 방법을 제안한다. 이를 위해서 MPEG-2 공간계층적 부호화구조에서 부호화율-왜곡의 관계를 찾고, 실시간으로 상위계층 영상 사이에 균등한 화필을 제공하는 부호화율 제어방법을 제안한다.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 1999.12a
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• pp.85-90
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• 1999

최근 홍수에 의한 피해가 늘어나면서 재해관리에 대한 문제점이 제기되고 있다. 따라서 홍수위험도를 바탕으로 한 과학적이고 체계적인 방재대책의 수립이 요구되어 진다. 본 연구에서는 대상자의 과거 홍수피해를 데이터베이스로 구축하고, 이를 활용한 홍수위해성과 홍수위험성을 분석하여 홍수위해도(Flood Hazard Map)와 홍수위험도(Flood Risk Map)로 도출하였다. 분석결과를 이용하여 현 방재계획에서 설정되어 있는 구호시설물의 서비스 지역을 분석하고, 구호시설물의 최적의 입지를 제시하였다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.06a
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• pp.35-36
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• 2016

본 논문에서는 기존 Bag-of-Visual words (BoW) 접근법에서 반영하지 못한 이미지의 공간 정보를 활용하기 위해서 Spatial Pyramid Matching (SPM) 기법을 Latent Dirichlet Allocation (LDA) 모델에 결합하여 이미지를 분류하는 모델을 제안한다. BoW 접근법은 이미지 패치를 시각적 단어로 변환하여 시각적 단어의 분포로 이미지를 표현하는 기법이며, 기존의 방식이 이미지 패치의 위치정보를 활용하지 못하는 점을 극복하기 위하여 SPM 기법을 도입하는 연구가 진행되어 왔다. 또한 이미지 패치를 정확하게 표현하기 위해서 벡터 양자화 대신 희소 부호화 기법을 이용하여 이미지 패치를 시각적 단어로 변환하였다. 제안하는 모델은 BoW 접근법을 기반으로 위치정보를 활용하는 SPM 을 LDA 모델에 적용하여 시각적 단어의 토픽을 추론함과 동시에 multi-class SVM 분류기를 이용하여 이미지를 분류한다. UIUC 스포츠 데이터를 이용하여 제안하는 모델의 분류 성능을 검증하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.5A
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• pp.331-340
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• 2009

In this paper, we propose a new power loading algorithm for orthogonalized spatial multiplexing(OSM) systems over flat-fading multiple-input multiple-output (MIMO) channels. Compared to SVD-based transmission scheme, the OSM scheme exhibits a good system performance with lower complexity and feedback overhead. To further improve the performance in OSM systems with power loading, we introduce a geometric approach on the Euclidean distance between the constellation points in the effective channel. Using this approach, we show that the optimal power loading parameters in terms of the minimum distance can be obtained. Simulation results demonstrate that our algorithm provides a 5dB gain at a bit error rate (BER) of $10^{-4}$ over that of no power loading case with both QPSK and 16-QAM. Consequently, our power loading algorithm allows us to significantly improve the system performance with one additional feedback value.

• Journal of the Korean Society of Costume
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• v.54 no.2
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• pp.1-9
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• 2004

This research aims at the development of Korean fashion design for the world market, which combines the western beauty and Korean tradition into the product design focusing on the styling concept. Through the example-analysis of structural elements which form Europe and Korean fashions, the styling concepts of functional change, beauty-combination, and tradition-conservation. are derived. The results are as follows : 1. Functionality needs to be improved by the structural change and the development of new materials from the traditional materials. 2. Beauty should come from the combination of natural patterns and western-spatial allocation, as well as from the front combination of western-beauty. 3. Tradition needs to be kept as Korean beauty and representation skills in the colors, accessaries, and in the spatial design. The styling concept for Korean fashion design in this research is related to the visual structural elements, and is not expanded to the styling concept of Korean image and/or feeling. Therefore future researches may follow on these un-expanded points. and also may continue the wide comparison between the Korean fashion design and oriental image fashion in Europe.

• Journal of Korean Association for Spatial Structures
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• v.22 no.2
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• pp.47-55
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• 2022

In this study, we focus on the feasibility of structural topology optimization for a steel-timber composite beam design of optimally allocating glue-laminated timbers into a web with openings under the condition of given steel flanges. The motivation of this study is to topologically take maximal stiffness harmonizing both tension and compression performance of the steel-timber composite beam and become the eco-frandly timber design for buidling members. As a result of this study, the key web-openings allocation becomes triangle spaces, i.e., empty or no materials, of optimal topologies of both a pure timber plate and a steel flange-web timber plate without web-openings. Several applicable examples verify the effectiveness of topology optimization for steel-timber beams with web-openings.

• Journal of KIISE:Databases
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• v.28 no.3
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• pp.418-429
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• 2001

Recently, a GIS has been applicable to the most important computer applications such as urban information systems and transportation information systems. These applications require spatial operations for an efficient management of a large volume of data. In particular, a spatial join among basic operations has the property that its response time is increased exponentially according to the number of spatial objects included in the operation. Therefore, it is not proper to the systems demanding the fast response time. To satisfy these requirements, the efficient parallel processing of spatial joins has been required. In this paper, the efficient method for creating and allocating tasks to balance statically the load of each processor in a parallel spatial join is presented. A task graph is developed in which a vertex weight is calculated by the cost model I have proposed. Then, it is partitioned through a graph partitioning algorithm. According to the experiments in CC16 parallel machine, our method made an improvement in the static load balance by decreasing the variance of a task execution time on each processor.