• Title/Summary/Keyword: Topological Characteristics

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Analysis of GIUH Model using River Branching Characteristic Factors (하천분기 특성인자를 고려한 지형학적 순간단위도 모형의 해석)

  • Ahn, Seung-Seop;Kim, Dae-Hyeung;Heo, Chang-Hwan;Park, Jong-Kwon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.5 no.4
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    • pp.9-23
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    • 2002
  • The purpose of this research was to develop a model that minimizes time and money for deriving topographical property factors and hydro-meteorological property factors, which are used in interpreting flood flow, and that makes it possible to forecast rainfall-runoff using a least number of factors. That is, the research aimed at suggesting a runoff interpretation method that considers the river branching characteristics but not the topographical and geological properties and the land cover conditions, which had been referred in general. The subject basin of the research was the basin of Yeongcheon Dam located in the upper reaches of the Kumho River. The parameters of the model were derived from the results of abstracting topological properties out of rainfall-runoff observation data about heavy rains and Digital Elevation Modeling(DEM). According to the result of examining calculated peak runoff, the Clark Model and the GIUH Model showed relative errors of 1.9~23.9% and 0.8~11.3%, respectively and as a whole, the peak values of hydrograph appeared high. In addition, according to the result of examining the time when peak runoff took place, the relative errors of the Clark Model and the GIUH Model were 0.5~1 and 0~1 hour respectively, and as a whole, peak flood time calculated by the GIUH Model appeared later than that calculated by the traditional Clark Model.

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Geocoding Scheme for Multimedia in Indoor Space Based on IndoorGML (IndoorGML을 활용한 실내공간 멀티미디어 위치 인코딩 방법)

  • Li, Ki Joune
    • Spatial Information Research
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    • v.21 no.4
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    • pp.35-45
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    • 2013
  • Most multimedia contains location information whether they are implicit or explicitly, and which are very useful for several purposes. In particular, we may use location information in defining query conditions to retrieve relevant multimedia. For this reason, a number of works have been done to organize and retrieve geo-referenced multimedia data. However, they mostly focus on outdoor space where position is identified by (x, y, z) coordinates. In this paper, we focus on multimedia in an alternative space, indoor space, which differs from outdoor space in several aspects. First indoor space is considered as symbolic space, where location is identified by a symbolic code such as room number rather than coordinates. Second, topological information is a crucial element in providing indoor spatial information services. Third, indoor space is in more micro-scale than outdoor space, which influences on determining the visibility of cameras. Based on these different characteristics of indoor space, we survey the requirements of management systems of indoor geo-referenced multimedia. Then we propose a geo-coding scheme for multimedia in indoor space as an extension of IndoorGML, an OGC(Open Geospatial Consortium) candidate standard for indoor spatial information. We also present a prototype system called, IngC (INdoor Geo-Coding) developed to store and manage indoor geo-referenced multimedia.

Design of GIS based Korean Reach File Supporting Water Quality Modeling (수질모델링 지원을 위한 GIS 기반 한국형 Reach File 설계)

  • Kwon, Moon-Jin;Kim, Kye-Hyun;Lee, Chol-Young
    • Journal of Korea Water Resources Association
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    • v.45 no.1
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    • pp.1-13
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    • 2012
  • Various input data required for water quality modeling have considerable impacts on modeling results and relevant analysis due to the absence of data standardization and lack of data accuracy. With this in mind, this study mainly focused on the designing Korean Reach File for more effective water quality modeling through the supply of database composed with accurate hydraulic and hydrologic data. The Korean Reach File is the hydraulic database with the locational information of individual reaches, and each reach represents the stream reach of homogeneous hydraulic characteristics. In detail, it has reach code designating each stream reach, and topological information including catalog unit, segment, marker and index. It was also designed considering linkage of existing codes such as stream name and stream code. The devised reach code was implemented to Kyungan River at the City of Gwangju of Kyunggi Province and the results showed that the reach code could effectively support the input database integrating basic numerous data required for water quality modeling based on a criterion as well as easier linkage and utilization with existing database. In addition, more systematic water quality management was enabled through the linkage of existing data such as treatment facilities, pollutant data, and management institutes using the reach codes defined for each stream section. In the future, more efforts need to be made to adopt the reach code as the national standard data thereby enabling utilization of numerous relevant database through the assigning of reach code to individual stream reaches nationwide.

Network Structures of The Metropolitan Seoul Subway Systems (서울 대도시권 지하철망의 구조적 특성 분석)

  • Park, Jong-Soo;Lee, Keum-Sook
    • Journal of the Economic Geographical Society of Korea
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    • v.11 no.3
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    • pp.459-475
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    • 2008
  • This study analyzes the network structure of the Metropolitan Seoul subway system by applying complex network analysis methods. For the purpose, we construct the Metropolitan Seoul subway system as a network graph, and then calculate various indices introduced in complex network analysis. Structural characteristics of Metropolitan Seoul subway network are discussed by these indices. In particular, this study determines the shortest paths between nodes based on the weighted distance (physical and time distance) as well as topological network distance, since urban travel movements are more sensitive for them. We introduce an accessibility measurement based on the shortest distance both in terms of physical distance and network distance, and then compare the spatial structure between two. Accessibility levels of the system have been getting up overall, and thus the accessibility gaps have been getting lessen between center located subway stops and remote ones during the last 10 years. Passenger traffic volumes are explored from real passenger transaction databases by utilizing data mining techniques, and mapped by GIS. Clear differences reveal between the spatial patterns of real passenger flows and accessibility. That is, passenger flows of the Metropolitan Seoul subway system are related with population distribution and land use around subway stops as well as the accessibility supported by the subway network.

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A Analysis on the Characteristics of Landscape Elements and the Reappearance Technique of Landscape Image in the Chinatown of Shanghai Street in Busan (부산 상해거리 상점 전면부 경관요소의 유형적 분석과 중국 전통 경관이미지의 재현 수법에 관한 연구)

  • Piao, Xiang-Hua;Kang, Young-Jo
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.30 no.2
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    • pp.130-141
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    • 2012
  • This study examines the characteristics of landscape elements and the reappearance techniques of traditional landscape image in Chinatown of the Shanghai Street in Busan, Korea. The subjects of the study are commercial buildings owned by Chinese residents, commercial buildings' naming design and environmental sculptures in the Shanghai Street. The results are as follows: First, the design methods of the front side of commercial buildings were classified into two parts: facede design of buildings and signboard design. The design form of the buildings' facades were classified into five types, there are: emphasis type on Chinese characters' signboard, addition type on decorative signboard, introduction type of traditional patterns, imitation type of traditional architectures and modern architectures' modes. The signs of chinese commercial buildings were observed mostly as having a traditional Chinese font in yellow/white on a red background. It has been found that this style was the most popular method of sign design. Secondly, The commercial buildings' naming design was analyzed into design methods and meanings. Design methods were classified into three types: a combination of meaning and place, a combination of season and atmosphere and tourist attractions. The meaning of the commercial buildings' names was divided into three kinds: the wishes of the prosperity, elegant type and the appropriation of local attractions. Thirdly, the environmental sculptures of Shanghai Street were found to have been influenced by both through out Chinese culture with mixed Korean culture. Finally, as for characteristics of landscape elements, we found three reappearance techniques - addition, replacement, juxtaposition. The technique of addition is added new face to the base map by just two methods - extending and overlapping area. Replacement is created new faces from base map by the action of replacing, it has three types - local replacement, package replacement, successive replacement. Juxtaposition is the fact of two or more things placed together with contrasting effect, it also has three types - the same kind juxtaposition, a different kind juxtaposition, topological juxtaposition. This study is the basic research which is analyzing the landscape design in chinatown. But the research only on Shanghai Street may have some limits in scope. It is considered an necessary study to add, which is about chinatown in other city such as Incheon, Jeonju. Then it is expected that the results of this study can be used for the basic data of the landscape plans, that municipalities are actively progressing their respective development projects of Chinatown.

Predicting the Performance of Recommender Systems through Social Network Analysis and Artificial Neural Network (사회연결망분석과 인공신경망을 이용한 추천시스템 성능 예측)

  • Cho, Yoon-Ho;Kim, In-Hwan
    • Journal of Intelligence and Information Systems
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    • v.16 no.4
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    • pp.159-172
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    • 2010
  • The recommender system is one of the possible solutions to assist customers in finding the items they would like to purchase. To date, a variety of recommendation techniques have been developed. One of the most successful recommendation techniques is Collaborative Filtering (CF) that has been used in a number of different applications such as recommending Web pages, movies, music, articles and products. CF identifies customers whose tastes are similar to those of a given customer, and recommends items those customers have liked in the past. Numerous CF algorithms have been developed to increase the performance of recommender systems. Broadly, there are memory-based CF algorithms, model-based CF algorithms, and hybrid CF algorithms which combine CF with content-based techniques or other recommender systems. While many researchers have focused their efforts in improving CF performance, the theoretical justification of CF algorithms is lacking. That is, we do not know many things about how CF is done. Furthermore, the relative performances of CF algorithms are known to be domain and data dependent. It is very time-consuming and expensive to implement and launce a CF recommender system, and also the system unsuited for the given domain provides customers with poor quality recommendations that make them easily annoyed. Therefore, predicting the performances of CF algorithms in advance is practically important and needed. In this study, we propose an efficient approach to predict the performance of CF. Social Network Analysis (SNA) and Artificial Neural Network (ANN) are applied to develop our prediction model. CF can be modeled as a social network in which customers are nodes and purchase relationships between customers are links. SNA facilitates an exploration of the topological properties of the network structure that are implicit in data for CF recommendations. An ANN model is developed through an analysis of network topology, such as network density, inclusiveness, clustering coefficient, network centralization, and Krackhardt's efficiency. While network density, expressed as a proportion of the maximum possible number of links, captures the density of the whole network, the clustering coefficient captures the degree to which the overall network contains localized pockets of dense connectivity. Inclusiveness refers to the number of nodes which are included within the various connected parts of the social network. Centralization reflects the extent to which connections are concentrated in a small number of nodes rather than distributed equally among all nodes. Krackhardt's efficiency characterizes how dense the social network is beyond that barely needed to keep the social group even indirectly connected to one another. We use these social network measures as input variables of the ANN model. As an output variable, we use the recommendation accuracy measured by F1-measure. In order to evaluate the effectiveness of the ANN model, sales transaction data from H department store, one of the well-known department stores in Korea, was used. Total 396 experimental samples were gathered, and we used 40%, 40%, and 20% of them, for training, test, and validation, respectively. The 5-fold cross validation was also conducted to enhance the reliability of our experiments. The input variable measuring process consists of following three steps; analysis of customer similarities, construction of a social network, and analysis of social network patterns. We used Net Miner 3 and UCINET 6.0 for SNA, and Clementine 11.1 for ANN modeling. The experiments reported that the ANN model has 92.61% estimated accuracy and 0.0049 RMSE. Thus, we can know that our prediction model helps decide whether CF is useful for a given application with certain data characteristics.

A Study on the sources of Jang Hyeongwang's Theories of Li and Ch'i (장현광 성리설의 연원에 대한 고찰 - 나흠순 성리설과의 관련을 중심으로 -)

  • Kim, Yong-Hun
    • (The)Study of the Eastern Classic
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    • no.41
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    • pp.7-35
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    • 2010
  • Jang Hyungang(張顯光, 1554~1570) was one of the very famous Neo-Confucianists of T'oegye School in the Chosun dynasty. Jang, nevertheless, refused to accept Toegye's theory and had developed his own theory called li-qi-gyeong-wi-seol(理氣經緯說). So the theory was very unique in the history of Korean Neo-Confucianism. He matained that Tao(道), meaning the universal process which all beings including the human must follow, is accomplished by the unity of li(理, principle) and qi(ch'i, 氣, material force). He compared li and qi to warp(經) and woof(緯). According to his explanation, Tao is fulfilled by combining li and qi, as a textile is woven the combination of warps and woofs. He could, for I know, succeed to emphasize the unity of li and qii through this theory. Lots of Scholars in the Chosun dynasty criticized Jang's theory of li and qi for regarding li and qi as one, and thought that the theory originated from Luo Ch'inshun(羅欽順, 1465~1547), a famous Neo-Confucianist of in Early Ming China. Luo Ch'inshun maintained li-qi metaphysical monism that li and qi is united entity. In this respect, it seems that Jang's theory is similar to Luo's. However, I think that there are very important differences between the two. It is true that the main characteristics of Jang's theory is the unified relations between li and qi in this world. In the system of his philosophy, nevertheless, the topological position of li and qi are different in grade each other. Jang insisted that li is a supreme being to be materialized and realized through the movement of qi'in the process of universal development. Qi is accordingly only a kind of matter which completes li. In this sense, Jang's theory can be regarded as li metaphysical monism that li is the only substance. It means that Jang Hyeongwang's theory is a great contrast to Luo Ch'inshun's li-qi metaphysical monism.