• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.06a
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• pp.286-292
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• 2008

RTLS 시스템은 이동 객체에 RTLS 태그를 부착한 후 태그에서 발산되는 신호를 이용하여 실시간으로 위치를 파악하는 시스템으로 최근 항만 물류 및 자산 관리 분야에서 객체의 실시간 위치를 파악하기 위해 활용되고 있다. RTLS 시스템은 태그의 위치를 측정하기 위해 삼각 측량 법이나, Proximity matching법을 사용한다. 삼각 측량법은 3개 이상의 리더에서 수신된 신호 세기나 신호의 도달 시간을 이용하여 삼각측량 방식으로 위치를 결정하는 알고리즘으로, 전파의 난반사나 장애물등에 민감하며, Proximity matching법은 위치 샘플링 값에 대한 근접성을 이용한 통계 정보를 바탕으로 하여 위치를 결정하는 알고리즘으로 위치 정확도를 높일 수 있으나, 샘플링 데이터 개수에 따라 정확도가 크게 변화하는 문제가 있다. 본 논문에서는 이러한 위치 정보의 오차를 줄이기 위하여, Fingerprint 방식의 확률 모델에 TDOA 방식에서 사용되는 요소들을 혼합하여 확률에 의한 불확실성을 줄이고 더 높은 정확도의 위치 정보를 전달하는 위치 보정 기법을 제안한다. 본 논문에서 제안하는 2단계 위치 보정 기법은 먼저, Fingerprint 데이터 셋으로부터 현재 측정된 위치의 신호정보를 이용한 확률 모델을 적용하여 단 하나의 후보자를 결정한다. 둘째, 측정된 정보와 후보자 위치 정보를 기반으로 TDOA에서 사용하는 기하학적 위치 결정 방법을 변형한 알고리즘을 이용해 측정된 위치를 보정함으로써, TDOA 방식이나, Fingerprint 방식 둘 중 하나만 사용하는 것보다 향상된 위치의 정확도를 제공한다. 그리고 본 논문에서는 제안한 위치 보정 기법을 위한 위치 보정 모듈을 설계하였으며, RTLS 미들웨어에 이를 반영하여 구현하였다.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.1
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• pp.183-188
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• 1992

Behaviour of 7 horned Japanese Black Cattle (3-9 years old) kept in a $450m^2$ dry-lot under loose housing condition was observed in the daytime (0930-1730 h) during 3 consecutive days. Eating and lying behaviour of cattle and the positions of all animals when lying together were recorded at 10-min intervals. Agonistic encounters and social licking interactions in the herd were also recorded. The cattle established a social hierarchy which was near linear. An irregularity in the diurnal rhythm of lying behaviour was found on the 3rd day, which appeared to be caused by oestrus behaviour of a herdmate. Eating frequency showed greater variation among individuals than lying frequency, and the most dominant animal ate most frequently in the herd. The spatial pattern of the herd when lying indicated a relatively loose dispersion in the lot. Higher ranking cattle tended to lie down more frequently near the hay rack in the lot, so that lower ranking animals had more difficult access to feed. Cattle with more social licking interactions had a tendency to lie down near each other irrespective of proximity of social order, therefore it was suggested that social preference among particular individuals occurred in the herd.

• Journal of Internet Computing and Services
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• v.1 no.1
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• pp.27-34
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• 2000

Recently, the use of Geographic Information System in each field of our society is on the increase according to the development of the Internet. But, thereis a problem of the user access latencies, the network traffic, and the server overload in Internet Geographic Information System because spatial data are transferred in large volumes. In this paper, we propose a cache algorithm on client side to solve the above problems. The proposed algorithm demonstrates the performance improvement over known studies by utilizing unit time and spatial proximity. In addition, this paper conducts a performance evaluation to measure the improvement in algorithm efficiency and analyzes the results of the performance evaluation. When spatial data queries are conducted, according to our performance evaluation, hit rate has been improved over the existing algorithms.

• Journal of Digital Contents Society
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• v.10 no.3
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• pp.395-400
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• 2009

The wide spread of the Internet service has brought in web GIS development. But, there are problems of the user access latencies, the network traffic, and the server overload in Internet Geographic Information System because spatial data are transferred in large volumes. In this paper, I propose a cache algorithm on client side to solve the above problems. The proposed algorithm demonstrates the performance improvement over known studies by utilizing unit time and spatial proximity. In addition, this paper conducts a performance evaluation to measure the improvement in algorithm efficiency and analyzes the results of the performance evaluation. When spatial data queries are conducted, according to our performance evaluation, hit rate has been improved over the existing algorithms.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.10
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• pp.19-30
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• 2019

The purpose of this study is to explore ways to efficiently capture the opinions of students who are main users in the planning, planning and design of school facilities. There are many criteria for determining good schools, but in this study, the main purpose of this study was to set up the main users as students, and to analyze the differences between the network and the actual spatial structure (network) created by the hope of students' use of school space, and the direction to overcome the differences. After surveying students' opinions about their satisfaction with school space and their desire to use school space by limiting the survey target to middle and high schools in Seoul, the 'social-space network analysis' was recently established in the social science field. As a result, it was found that the proximity of space and space desired by students in the school varied greatly depending on the geographical conditions, school districts, and the status of the current facilities, and the direction of improvement specialized for each school was found.

• Journal of the Economic Geographical Society of Korea
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• v.8 no.1
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• pp.107-130
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• 2005

The purpose of this study were to examine the spatial distribution and locational characteristics of the Internet movie industry, to seize the value chains of the Internet movie industry and distribution structure of the internet movies, and to analyze the vertical-horizontal linkages of the Internet movie firms and their spatial clustering. Recently, the Internet movie industry has developed rapidly due to the development of techniques related to movie contents, the broadband Internet and a wide expansion of the high speed communication network and the increase of demands on movie contents. It has been found that 74$\%$ of the Internet movie industry was concentrated in Seoul. Especially this industry was quite agglomerated in several dongs of Gangnam-gu such as Yoeksam, Nonhyeon, Daechi and Samseung. The proximity of the same or similar business firms was the primary locational factors that influenced on the Internet movie industry, followed by other factors such as convenience of transportation, the reputation of the place, and proximity of technically supporting firms. The Internet movie industry had the valve chain composed of 'contents suppliers $\rightarrow$ contents distributors $\rightarrow$ service providers', However, there were also a complex network of the VOD copyright owner, VOD syndicator, and service providers in each category of the value chain. This research clearly revealed that the localized clustering has been formed with the movie contents providers, technically supporting firms, client firms, and cooperative-affiliated business firms related to the Internet movie industry, Additionally, a very intimate network has been established within the clustering, inducing the enlargement of the market and decrease of costs, the co-sharing of tacit knowledge, and the synergy effect.

• Journal of the Korean association of regional geographers
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• v.12 no.4
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• pp.508-521
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• 2006

The results of environmental equity analysis vary dramatically depending on different methods used. The information and data available to the researcher are also often uncertain and imprecise in empirical studies. A sensitivity analysis approach was used too handle uncertainties and methodological inconsistencies in environmental equity analysis. This paper explores the sensitivity of environmental equity analysis to two spatial measures such as proximity and scale. Two experiments were implemented to evaluate the effects of two spatial measures on the environmental equity analysis using a combination of control and experimental factors. Fulton County, Georgia was selected as a case study area for these experiments. Two major data sets including demographic characteristics and toxic release inventory (TRI) database for the study area in 1990 were integrated into a GIS environment. Two statistical analyses such as independent samples t-test and coefficient of variation were performed to determine the environmental equity in the study area and to compare the relative variability in the socioeconomic characteristics of populations over different spatial measures. The findings from two experiments indicate that the outcomes of environmental equity analysis are slightly sensitive to the buffer distance used to determine the impact zones of TRI facilities, but not to the geographic scale used in the analysis. The findings also suggest that the consequences of these choices can alter spatially and statistically the results in environmental equity analysis.

• Spatial Information Research
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• v.8 no.2
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• pp.233-241
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• 2000

The objective of this study were to develop landscape scale ecosystem assessment model, and apply the model for the assessment of the state and change of ecosystem of the study area, Yongin, Korea. Since natural ecosystem of the site has been deteriorated significantly during recent extensive residential development, it is essential to correctly assess ecosystem of the study site. Traditional ecosystem assessment mainly utilizing intensive field survey requires high cost, but the outcome rarely represents spatial pattern of the regional ecosystems. Ecosystem assesment of landscape scale based on landscape ecology can resolve most of the shortfalls of the traditional approach. The research method can be summarized as follows. First, extensive literature review on such topics as spatial pattern of ecosystem, ecosystem assessment of landscape scale, ecological analysis was carried out. Second, a model for the ecosystem assessment of landscape scale emphasizing spatial pattern of ecosystem was developed. This model evaluates three indicators; ecological integrity and biological diversity, watershed integrity, and landscape resilience of 11 watersheds in the study area. Finally, ecological assessment utilizing two sets of indicators, enhancement of and disturbance of ecosystem stability, was carried out. This assessment method is based on Environmental Monitoring and Assessment Program´s Landscape component(EMAP-L) of EPA(1994). The results of this study are as follows. First, the ecosystem assessment of landscape scale of the study area of Yongin, Korea, showed that escosystems of Tanchun01 and Chungmichun01 watersheds had the worst state in the study site in 1991. On the other hand, the ecosystems of Jinwechun01, Kyunganchun02, and Bokhachun01 watersheds had the most stable ecosystem in 1991. Second, ecosystems of Tanchun01, Shingal reservoir, and Kyunganchun01 watersheds were evaluated to be the worst state in the study site in 1996. And, ecosystems of Jinwechun01 and Gosam reservoir watersheds had the most stable ecosystem. Third, ecosystem of Tanchun01 watershed which incudes Suji residential development project site changed the most drastically between 1991 and 1996. The ecosystem of the watershed the most drastically deteriorated due to it´s proximity to Seoul and Bundang new town.

• Spatial Information Research
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• v.14 no.4 s.39
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• pp.391-401
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• 2006

We propose a method for geographically enhanced representation of social networks and implement a Web-based 3D visualization of geographical contexts in social networks. A renovated social network graph is illustrated by using two key components: (i) GWCMs (geographically weighted centrality measures) that reflect the differences in interaction intensity and spatial proximity among nodes and (ii) MSNG (map-integrated social network graph) that incorporates the GWCMs and the geographically referenced arrangement of nodes on a choroplethic map. For the integrated 3D visualization of the renovated social network graph, we employ X3D (Extensible 3D), a standard 3D authoring tool for the Web. An experimental case study of regional R&D collaboration provides a visual clue to geographical contexts in social networks including how the social centralization relates to spatial centralization.

• Journal of KIISE
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• v.42 no.5
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• pp.652-663
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• 2015

Due to the popularity of location-based services, the amount of generated spatial data in daily life has been dramatically increasing. Therefore, spatial database outsourcing has become popular for data owners to reduce the spatial database management cost. The most important consideration in database outsourcing is meeting the privacy requirements and guarantying the integrity of the query result. However, most of existing database transformation techniques do not support both of the data privacy and integrity of the query result. To solve this problem, we propose a spatial data transformation scheme that utilizes the shearing transformation with rotation shifting. In addition, we described the attack models to measure the data privacy of database transformation schemes. Finally, we demonstrated through the experimental evaluations that our scheme provides high level of data protection against different kinds of attack models, compared to the existing schemes, while guaranteeing the integrity of the query result sets.