• The KIPS Transactions:PartD
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• v.12D no.2 s.98
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• pp.179-188
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• 2005

Much research for spatial join has been extensively studied over the last decade. In this paper, we focus on the filtering step of candidate objects for spatial join operations on the input tables that none of the inputs is indexed. In this case, many algorithms has presented and showed excellent performance over most spatial data. However, if data sets of input table for the spatial join ale skewed, the join performance is dramatically degraded. Also, little research on solving the problem in the presence of skewed data has been attempted. Therefore, we propose a spatial hash strip join (SHSJ) algorithm that combines properties of the existing spatial hash join (SHJ) algorithm based on spatial partition for input data set's distribution and SSSJ algorithm. Finally, in order to show SHSJ the outperform in uniform/skew cases, we experiment SHSJ using the Tiger/line data sets and compare it with the SHJ algorithm.

• Journal of the Korean earth science society
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• v.31 no.3
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• pp.259-266
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• 2010

High school students' understanding hierarchy of astronomical concepts and an individual student's knowledge state are analyzed by using the knowledge space theory that allows one to infer an individual's entire knowledge on a subject based on fragmentary information coming from that student's answers. The hierarchy of astronomical space concepts is: spatial position$\ll$spatial reasoning$\ll$spatial variation. In addition, an analysis of assessment materials using the knowledge space theory shows not only the relationship of assessment questions but also the knowledge state of individual students, which the current evaluation method is not able to reveal. Therefore, the assessment analysis of this study using the knowledge space theory becomes critically instrumental in providing information of an instructional differentiation amenable to individual learners for deciding their level of understanding and selecting suitable curriculum.

• Journal of the Korean Society for Library and Information Science
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• v.46 no.2
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• pp.219-243
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• 2012

The purposes of this study are to develop spatial factors for children's libraries and fulfill the evaluation of importance of expert and user groups for it. So, this study developed spatial evaluation factors by analyzing materials of domestic/international groups and associations and precedent studies, drawing spatial factors and organizing them. Next, for the spatial factors developed to 12 evaluation areas and 127 detailed indexes, an importance was evaluated for 4 expert groups; children's librarians, people majoring in early childhood education, elementary school's librarians, people in charge of architecture, etc. and 3 groups; infants, elementary school's lower grades, elementary school's high grades, etc. The evaluation results are as follows. First, the expert groups approved an importance of indexes by evaluating all of the 12 evaluation areas and 120 indexes of 127 detailed indexes as more than 3.0. Second, the user groups also approved an importance of indexes by evaluating all of 12 evaluation areas and 125 detailed indexes of 127 detailed indexes as more than 3.0. Third, as the result of evaluating an importance between expert groups and user groups, there was a difference between two groups in 2 areas among the 12 evaluation areas.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10a
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• pp.109-111
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• 2001

공간데이터베이스에서 공간 질의를 최적화하기 위해서는 질의 결과 크기를 계산하는 것이 필수적이다. 그러나 공간 데이터베이스의 크기는 매우 방대하여 질의 결과 크기를 계산하는데 비용이 많이 든다. 이러한 문제를 해결하기 위해서는 실제 공간 데이터의 분포와 특성에 근접하도록 공간 데이터의 분포를 요약하여 이를 토대로 질의 결과 크기를 추정하는 것이 효과적이라 할 수 있다. 공간 분할 방법에는 균등분할 방법과 비균등 분할 방법이 있으면, 본 논문에서 제안한 방법은 1차원 데이터에 대한 선택률 추정기법 중에서 그 성능이 가장 우수하다고 평가된 바 있는 최대 면적 차이 분말을 공간 데이터베이스에 적용하여 공간 분할하는 것이다. 공간 데이터베이스에서 선택을 추정 방법은 공간 분할 방법에 따라 성능상의 차이가 있으며 본 논문은 기존의 방법과 제안한 방법을 실험을 통하여 선택률 추정의 정확성을 비교, 평가하여 제안한 방법이 우수함을 보였다.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.1
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• pp.1-12
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• 2005

Land suitability assessment is the procedure that assesses development, agriculture or conservation suitability of land according to such criteria as soil, location and usability. But there are many problems to execute land assessment by law. Problems include inadequate basic data, lack of linkage with the spatial planning system, and inefficiency in operation. The purpose of this study is to improve methods of land suitability assessment as a sustainable land use management tool using case study. In this study, land suitability assessment will be executed through GIS. On the basis of the results of this case study, practical and institutional problems are described, and technical solutions are suggested.

• Journal of the Korean Institute of Landscape Architecture
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• v.38 no.5
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• pp.12-20
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• 2010

The purpose of this study is to evaluate human thermal comfort by spatial structure and to explore solutions to improve the thermal environment of a small urban space. The study site was Korea University campus. Thermal conditions were measured to evaluate the quality of the thermal environment in each type of space within the study site. Micrometeorology measurements, analysis of space characteristics for using fish-eye lens photography, and thermal comfort modeling through the use of collected meteorological data, such as temperature and humidity, were performed. Results showed that the level of thermal comfort for humans differs depending on the types of space within the study site. Thermal comfort is better in open spaces than enclosed in the aspect of radiative mean temperature, Predicted Mean Vote(PMV), and Physiologically Equivalent Temperature(PET). This fact is probably due to shadows or buildings or trees that may block solar radiation. Thus, it is necessary to consider the spatial arrangements of buildings and trees to enhance openness and ventilation in the space. Paving materials and exterior building materials should also be selected to lower the radiant temperature. Given these results, a quantitative evaluation on human thermal comfort could propose a way to plan user comfortable small urban spaces. Study methods used and results provided in the study can promote a better way for urban space planning direction to improve environmental quality.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.5-5
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• 2015

현재 우리나라에서 지상관측장비인 AWS(Automatic Weather System)와 ASOS(Automated Synoptic Observing System)기구가 한반도내 668개 지점에서 운영되고 있다. 이러한 장비는 지상관측장비로 하나의 지점에서 측정된 기상변량들이 특정 영역의 대푯값으로 사용되어지고 있다. 기존의 다양한 지점 단위의 수문 모형에서는 지상관측소를 통한 관측값을 적용하기에 어려움 없이 적절한 결과를 도출할 수 있었다. 컴퓨터의 발달로 인하여 복잡한 물리적 현상을 공간적으로 분석할 수 있는 모형의 구동이 가능해짐에 따라서 수문 분야에서도 다양한 분포형 해석 모형이 활발하게 개발 및 적용되고 있다. 지점 관측 자료는 공간적인 연속성을 반영하지 못하는 한계로 인하여 지점 관측자료를 이용한 공간자료의 생성 기법들이 사용되어지고 있지만 자연계에서 나타나는 정확한 공간적 현상을 재현해주지 못하는 문제점이 존재한다. 이러한 지점 관측의 한계를 해결하기 위하여 공간적인 관측이 가능한 레이더와 위성관측과 같은 원격 관측 장비들이 개발되어 공간적으로 연속성을 갖는 기상변량의 취득이 가능하여졌다. TRMM 강우자료는 지구 전체를 0.25도 약 25km 공간해상도를 갖으며 3시간 간격으로 제공되고 있다. 유역단위의 수문모형에 적용하기에 TRMM 강수자료의 공간해상도는 너무 커서 직접적인 적용에 어려움이 있다. 이러한 점에서 TRMM 자료의 상세화 기법을 통하여 수문모형에 적용이 가능한 1km 이하의 고해상도 자료를 생산하는 연구들이 진행되고 있다. 이러한 상세화 방법은 최종적으로 도출하고자 하는 공간해상도를 갖는 대체 변량(지표면 온도, 고도, 식생, 해수면 기압, 상대 습도, 대기온도, 풍향 등)을 이용하여 회귀분석의 형태로 분석이 이루어지고 있다. 그러나 대체 변량을 통해 도출된 상세화된 TRMM 강우는 간접적인 추정으로 인하여 정확한 결과의 도출에는 한계가 있을 것으로 판단된다. 이러한 점에서 본 연구에서는 한반도내 지상 관측값을 공간적 자료로 변환하여 주는데 효과적으로 평가받는 PRISM 모형에 적용하여 기존 SVM 모형을 통한 TRMM 상세화 결과가 갖는 정확성을 평가해 보고 지점 관측자료의 보간 기법의 평가에 TRMM 자료를 활용하는 방안에 대해 평가해 보고자 한다.

• Journal of the Korean Society for Library and Information Science
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• v.53 no.3
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• pp.215-245
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• 2019

The purpose of this study is to derive evaluation elements on teen space in public libraries in Korea and to study current status and implications for teen space in public libraries. To this end, six items of space evaluation factors; Convenience, Accessibility, Safety, Diversity, Comfort and Emotionality - were derived based on the teen space guidelines by the Young Adult Library Service Association and previous studies. The research also conducted a case study on teen spaces of five public libraries in Seoul. As a result, teen space in libraries requires use guidance and convenience facilities, access to information resources, maintenance of user guidelines, various spaces for teens, pleasant library environment and learning motivation promotion, and provision space to support all necessary resources of teens.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.12
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• pp.795-806
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• 2017

In this paper, we propose a user experience evaluation method for virtual reality living space contents and apply it to prototype simulations to measure user experience. The user evaluation method proposed in this paper is based on the existing user evaluation methodology, but it is established by changing the experience and evaluation factors to match the characteristics of the virtual reality living space. The generated virtual reality living space simulation is configured similar to real space and is placed real objects that the user actually uses in each space, so that users can feel reality. The subjects performed the tasks according to the given scenarios and then evaluated the simulation. As a result of the evaluation, the main goal of the simulation, the items that make the users feel realistic, were lower than our expectations. This means that future simulations need to be modified in a way that adds or expands elements that enhance the realism. In this way, the UX evaluation method proposed in this paper is expected to provide a more objective indicator to the content developer or designer in order to grasp the user's demand in the virtual reality living space.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.4
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• pp.159-164
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• 2014

These days, inexpensive and high efficiency UAV of disaster prevention and spatial information has been given more attention. But studies about test of accuracy of UAV were not enough despite high interest. This research produced DSM and ortho photo and estimated accuracy by comparing coordinates with GNSS survey to evaluate outcome of fixed wing UAV. The ortho photo was found to make use of it to update 1/1,000 map. This research investigated spatial information construction using existing terrestrial LiDAR to suggest effectiveness of fixed wing UAV.