• Journal of Intelligence and Information Systems
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• v.17 no.1
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• pp.111-125
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• 2011

Clustering is a process of grouping similar or relevant documents into a cluster and assigning a meaningful concept to the cluster. By this process, clustering facilitates fast and correct search for the relevant documents by narrowing down the range of searching only to the collection of documents belonging to related clusters. For effective clustering, techniques are required for identifying similar documents and grouping them into a cluster, and discovering a concept that is most relevant to the cluster. One of the problems often appearing in this context is the detection of a complex concept that overlaps with several simple concepts at the same hierarchical level. Previous clustering methods were unable to identify and represent a complex concept that belongs to several different clusters at the same level in the concept hierarchy, and also could not validate the semantic hierarchical relationship between a complex concept and each of simple concepts. In order to solve these problems, this paper proposes a new clustering method that identifies and represents complex concepts efficiently. We developed the Hierarchical Overlapping Clustering (HOC) algorithm that modified the traditional Agglomerative Hierarchical Clustering algorithm to allow overlapped clusters at the same level in the concept hierarchy. The HOC algorithm represents the clustering result not by a tree but by a lattice to detect complex concepts. We developed a system that employs the HOC algorithm to carry out the goal of complex concept detection. This system operates in three phases; 1) the preprocessing of documents, 2) the clustering using the HOC algorithm, and 3) the validation of semantic hierarchical relationships among the concepts in the lattice obtained as a result of clustering. The preprocessing phase represents the documents as x-y coordinate values in a 2-dimensional space by considering the weights of terms appearing in the documents. First, it goes through some refinement process by applying stopwords removal and stemming to extract index terms. Then, each index term is assigned a TF-IDF weight value and the x-y coordinate value for each document is determined by combining the TF-IDF values of the terms in it. The clustering phase uses the HOC algorithm in which the similarity between the documents is calculated by applying the Euclidean distance method. Initially, a cluster is generated for each document by grouping those documents that are closest to it. Then, the distance between any two clusters is measured, grouping the closest clusters as a new cluster. This process is repeated until the root cluster is generated. In the validation phase, the feature selection method is applied to validate the appropriateness of the cluster concepts built by the HOC algorithm to see if they have meaningful hierarchical relationships. Feature selection is a method of extracting key features from a document by identifying and assigning weight values to important and representative terms in the document. In order to correctly select key features, a method is needed to determine how each term contributes to the class of the document. Among several methods achieving this goal, this paper adopted the $x^2$�� statistics, which measures the dependency degree of a term t to a class c, and represents the relationship between t and c by a numerical value. To demonstrate the effectiveness of the HOC algorithm, a series of performance evaluation is carried out by using a well-known Reuter-21578 news collection. The result of performance evaluation showed that the HOC algorithm greatly contributes to detecting and producing complex concepts by generating the concept hierarchy in a lattice structure.

• Journal of the Korean Association of Geographic Information Studies
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• v.15 no.2
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• pp.46-56
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• 2012

Recently, when software architecture is designed, the efficiency of reusability is emphasized. The reusability of the design can raise the quality of GIS software, and reduce the cost of maintenance. Because the object oriented GoF design pattern provides the class hierarchy that can represent repetitively, the importance is emphasized more. This method that designs the GIS software can be applied from various application systems. A multiple distributed sensor network system is composed of the complex structure that each node of the sensor network nodes has different functions and sensor nodes and server are designed by the combination of many classes. Furthermore, this sensor network system may be changed into more complex systems according to a particular purpose of software designer. This paper will design the CATL model by applying Facade pattern that can enhance the efficiency of reuse according to attributes and behaviors in classes in order to implement the complicated structure of the multiple distributed sensor network system based on TinyOS. Therefore, our object oriented GIS design pattern model will be expected to utilize efficiently for design, update, or maintenance, etc. of new systems by packing up attributes and behaviors of classes at complex sensor network systems.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.6
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• pp.933-943
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• 2019

The purpose of this study is to identify determinants for preferred funeral methods depending on socio-economic characteristics. In South Korea, the Act on Funeral Services, Etc. categorizes funeral methods into burial, inurnment, and natural burial. This study empirically analyzes how and what socio-economic characteristics affect choices among these three categories. Data is collected from Social Survey 2017 and funeral facilities in the country. The data to be analyzed is developed in terms of a hierarchy which puts the burial and cremation methods in an upper class and the inurnment and natural burial methods in a lower class. Based on this data, a nested logit model is employed to conduct empirical analysis. The analysis indicates that those characteristics that have a statistically significant influence on preferred methods include gender, age, householder, marriage, satisfaction with life, class awareness, monthly income, housing type, housing tenure type, and living in city area. Each variable's modulus of calculated direct and cross elasticity need to be used to analyze the outcome of a nested logit model. In this study, the modulus of direct and cross elasticity are determined for the significant variables. The calculated direct elasticity is applied to analyze the likelihood of choosing each funeral method when there are changes in the significant variables. When a particular method has been selected, on the other hand, the cross elasticity is utilized to analyze changes to the likelihood of choosing the other methods. One of the most notable results is related to natural burial. In order to meet the demand for natural burial, it is necessary to provide more burial sites and raise awareness of natural burial. This will facilitate the efficient use of national territorial space.

• Journal of the Korean Geographical Society
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• v.38 no.5
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• pp.741-753
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• 2003

This study begins with paying attention to the agglomeration of 'Residential-Commercial Mixed Use Buildings(hereafter, R-C MU Buildings)', which tend to be a high grade and large sized building cluster at various neighboring areas in Seoul. The purpose of this study is to understand the relationship between emerging new housing type and residential area by analyzing the characteristics of residential neighborhood that is mainly created by R-C MU Buildings. For this purpose, the specialization and the regional characteristics(in connection with the hierarchy in urban spatial structure) of R-C MU Building's residential neighborhood were analyzed. In the end, the specific type of housing reveals the tendency to be differentiated in terms of income, education and occupation related with housing and residential area. And the residential characteristics also seem to be different according to the regions based on the central place hierarchical structure. It means that the social and class factors are important in choosing house, but the characteristics of the neighborhood area play an important role in the selection of resident area. Finally, the location of certain type of housing can influence the selecting process of residence and it can also determine the characteristics of the resident area in turn.

• Journal of Korean Society of Forest Science
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• v.109 no.2
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• pp.124-135
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• 2020

Alder (Alnus japonica) forests are representative of the wetland in East Asia, including Korea. In the past, alder forests were relatively common in various habitats such as mountains, riversides, back marshes, and alluvial plains. However, this plant community has recently become rare due to increasingly arid habitats and the influence of various land uses. In this study, we identify the synecological characteristics of alder (A. japonica) forests distributed naturally in the mountainous wetlands of Korea and provide basic data for their systematic conservation and management in the future. Based on vegetation survey data collected from 66 alder forests, community types were classified using the methods of the Zürich-Montpellier School of Phytosociology and two-way indicator species analysis. There were eight community types: Styrax obassia, Weigela subsessilis-Fraxinus mandschurica, Spiraea fritschiana, Viola verecunda, Impatiens textori-Spiraea salicifolia, Glyceria leptolepis, Molinia japonica, and Lindera obtusiloba-Quercus acutissima. These community types constituted a vegetation unit hierarchy of two communities, four subcommunities, and eight variants. In addition, the ecological characteristics of each community type were compared (including total coverage per 100 square meter, importance value index, constancy class, life-form composition, diversity indices, community similarity coefficient, and indicator species).

• Korean Journal of Construction Engineering and Management
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• v.6 no.4 s.26
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• pp.101-112
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• 2005

Recently, a curtain wall construction is a exterior finishing components which is most used for shortening time in high-rise building as well as the class of key management factors in cost and schedule control. Also, it is recognized that an effective management for curtain wall process is a major subject to accomplish the project successfully. However, as the current management for curtain wall construction is focused on the construction stage, it makes problems such as errors in business performance, rework by mistakes and duplications, errors and omissions by ineffective information management and there has never been any efficient management from a view of the entire Curtain Wall Life-cycle process. Therefore, the aim of this study is to suggest a stage check point for process improvement in the curtain wall Life-cycle process through current curtain wall process analysis, and then to investigate the cause of waste factors using the Muda method from the Toyota Production System and extract the weighted effects of the waste factors using the analytical hierarchy process method. According to the result, Most of the inefficient factors happened in architectural design stage of the entire curtain wall Life-cycle process and my research identified that detail factors of them are a delay of decision making and an approval in changes, a deficit of engineering capacity and a delay of approval in architectural design drawings by owner, etc.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.218-225
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• 2020

This study analyzed the priorities of the cross-compliance items of public-benefit direct payment using an Analytic Hierarchy Process and Fuzzy Decision Making Analysis. The valuation criteria are policy efficiency, farm acceptability, and feasibility, and the valuation targets are the basic and additional cross-compliance items. The survey was performed by targeting 50 experts from each class, and conducted for about a month starting from the beginning of July 2019. The results show that the weight of the valuation criteria is higher in the order of farm acceptability, feasibility, and policy efficiency. Compliance with PLS standards, compliance with disposal standards of waste vinyl and pesticides, soil testing, compliance with toxic substance standards, education, etc. are comparatively evaluated to be higher cross-compliance items in basic cross-compliance. Disposing of an abandoned well, jointly collecting and disposing of agricultural by-products, common area care and cleaning, maintenance of empty houses and poor facilities, growing green manure crops during the fallow period, etc. are comparatively evaluated to be higher cross-compliance items for the additional cross-compliance. The results of this study are expected to contribute to the government's policy related to the cross-compliance of public-benefit direct payment.

• Journal of the Korean Regional Science Association
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• v.37 no.4
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• pp.33-47
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• 2021

In urban declining areas, the population is decreasing, and drying environments such as buildings and facilities are aging. Therefore, it is vulnerable in the event of disaster, and recovery takes a lot of time and money. The purpose of this study is to develop an evaluation technique for comprehensively diagnosing disasters in declining areas and to present implications through case analysis. Evaluation indicators were selected to calculate the comprehensive diagnosis index of disasters, and weights were calculated for each class, including disaster types, components, and evaluation indicators, through Analytic Hierarchy Process analysis. The comprehensive diagnoses index for each type of disaster was calculated with the calculated weight, and the risk according to the level of urban decline was analyzed. As a result of analyzing Seoul as a case area, it was analyzed that the overall risk of disasters was high in southern regions such as Seocho-gu, Dongjak-gu, Geumcheon-gu, and Gangseo-gu, and relatively low in downtown and northern Seoul, parks and green areas. The results of this study are of academic significance in that they presented a comprehensive diagnostic index evaluation system and technique for each type of disaster, including natural and social disasters.

• The Journal of the Convergence on Culture Technology
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• v.8 no.1
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• pp.85-92
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• 2022

In order to identify the factors and problems in which military sexual violence is a continuous and repeated blind spot, this study conducted a content analysis focusing on articles of military sexual violence incidents covered in Internet news from January 2010 to June 15, 2021. carried out. As a result of the study, structurally unequal power relations, authoritarian and closed military organizational culture, internal military response system that is distrustful of passive responses to sexual violence, and enveloping family-friendly investigations and tolerant punishment of perpetrators are blind spots despite the Ministry of National Defense's efforts to improve. factors that exist. Underlying this, the compensatory spirit caused by the conscription system and the negative effects of the patriarchal system are embodied in the national sentiment, suggesting that the sense of crisis of division and an overly permissive attitude toward the military act as a factor that slows change. As an improvement plan according to the results, it is necessary to entail the establishment of a civilian-centered judicial institution, strong punishment of perpetrators, and limited pension payment, as well as honorable punishment such as 'class demotion' in the military culture with a clear hierarchical relationship. Taken together, we can see that most military sexual violence is caused by a hierarchy, and it strongly suggests that the main cause of sexual violence is unequal power relations.

• Journal of the Korean Society for information Management
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• v.40 no.2
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• pp.157-182
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• 2023

This study analyzed the structure and utilization of subject headings in the National Library of Korea Subject Headings List (NLSH) based on an analysis of subject headings assigned to 1,218,867 national bibliographies from 2003 to 2022. The findings of the study are as follows: Firstly, among all subject headings in the NLSH, there were 257,103 preferred terms, accounting for 50.2% of the total terms. Foreign language terms constituted 33% (169,466), while non-preferred terms comprised 12% (61,442). Among the preferred terms, 57,312 subject headings were used, accounting for 22.3%. However, it was observed that 54.7% (31,351) of these subject headings were assigned less than 5 times, indicating that only a small number of subject headings were frequently utilized. Secondly, the frequency of relationship indicators appeared in the order of RT, BT, and NT. The NLSH consisted of 12,602 top-level subject headings and 143,704 lowest-level subject headings, with a maximum depth of 17 levels. Thirdly, on average, 1.72 subject headings were assigned per bibliographic record. The number of subject headings assigned and the depth of the hierarchy increased for materials with more specific contents. Recent bibliographic records have been assigned more subject headings and deeper into the hierarchy of the NLSH. It was also found that the number of subject headings assigned per bibliography varied depending on the main class of KDC. Based on the findings, it is recommended to evaluate the coverage of terms in the NLSH, reorganize hierarchical relationships and depth of subject headings, and enhance the development of subdivisions within the NLSH.