• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.3
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• pp.541-550
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• 2015

The importance of efficient enterprise network management has been emphasized continuously because of the rapid utilization of Internet in a limited resource environment. For the efficient network management, the management policy that reflects the characteristics of a specific network extracted from long-term traffic analysis is essential. However, the long-term traffic data could not be handled in the past and there was only simple analysis with the shot-term traffic data. However, as the big data analytics platforms are developed, the long-term traffic data can be analyzed easily. Recently, enterprise network resource efficiency through the long-term traffic analysis is required. In this paper, we propose the methods of collecting, storing and managing the long-term enterprise traffic data. We define several classification categories, and propose a novel network resource efficiency through the multidirectional statistical analysis of classified long-term traffic. The proposed method adopted to the campus network for the evaluation. The analysis results shows that, for the efficient enterprise network management, the QoS policy must be adopted in different rules that is tuned by time, space, and the purpose.

• The KIPS Transactions:PartD
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• v.18D no.3
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• pp.157-168
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• 2011

Recently flash memory has been being utilized as a main storage device in mobile devices, and flashSSDs are getting popularity as a major storage device in laptop and desktop computers, and even in enterprise-level server machines. Unlike HDDs, on flash memory, the overwrite operation is not able to be performed unless it is preceded by the erase operation to the same block. To address this, FTL(Flash memory Translation Layer) is employed on flash memory. Even though the modified data block is overwritten to the same logical address, FTL writes the updated data block to the different physical address from the previous one, mapping the logical address to the new physical address. This enables flash memory to avoid the high block-erase cost. A flashSSD has an array of NAND flash memory packages so it can access one or more flash memory packages in parallel at once. To take advantage of the internal parallelism of flashSSDs, it is beneficial for DBMSs to request I/O operations on sequential logical addresses. However, the B-tree structure, which is a representative index scheme of current relational DBMSs, produces excessive I/O operations in random order when its node structures are updated. Therefore, the original b-tree is not favorable to SSD. In this paper, we propose AS(Always Sequential) B-tree that writes the updated node contiguously to the previously written node in the logical address for every update operation. In the experiments, AS B-tree enhanced 21% of B-tree's insertion performance.

• Journal of Information Management
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• v.43 no.1
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• pp.63-87
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• 2012

This study aims to analyse the actual condition of the ebook services and propose the improvements of ebook services for children in the Korean public library. For this purpose, the current condition of the ebook services in the public libraries were analyzed and categorized by three criteria. Secondly, the ebook use analysis was conducted using PCs and mobile devices in terms of access to ebook library site, searching method, contents type and viewer, lending process, and user help. As a result of the analysis, several issues such as the difficulty in access to ebook site, the complexity of setting and usage depending on the file format, the insufficient user guide, the relatively lower quality service than the commercial's, and the lack of retrieval functions specialized for the ebook were presented. The improvement plan for the ebook services, especially for children in the public library was suggested.

• Journal of the Korean association of regional geographers
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• v.4 no.1
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• pp.27-41
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• 1998

The communication model has been accepted as the basic research paradigm of cartography since Board(1967) discussed the map/model analogy. In that paradigm, the function of maps was limited to the media of communication, and the functionality of maps was extremely emphasized. Therefore the model could not play its own role under the new environments such as computer, GIS, scientific visualization. Nowadays, the model has been attacked on several grounds and several alternatives have been suggested. Among the objections raised are (1) geographic visualization in which maps are considered as the tool of scientific visualization, (2) the contributions of art which are ignored in the positivist cartographic research, and (3) deconstructionist arguments which deny the scientific epistemology of map as an objective form of knowledge and recognize the textuality of maps including their metaphorical and rhetorical nature. Since a publication by McCormick et al, the scientific visualization based on the powerful computer graphics is used in a wide context. Maps are treated as the tools of scientific visualization and emphasis is on exploration of the geographic data to gain understanding and insight in the geographic visualization processes. The research on geographic visualization have stayed in the early stage of developing the conceptual model and the basic visualization tools. But, it is expected that the geographic or visual thinking which is emphasized in the geographic visualization will contribute the reestablishment of links between cartography and geography. Also, the development of scientific visualization tools and strategies will offer the opportunities to suggest a fresh idea, to synthesize information and develop holistic approaches to geographical problems.

• Journal of the Korean association of regional geographers
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• v.19 no.1
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• pp.75-96
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• 2013

This paper is to conceptualize the urban social circulation of water from the social constructivism and political ecology, and to analyze the history of development of social circulation of water, that is, the modernization process of water in Daegu. The development of social circulation system of water in Daegu can be divided into 4 stages, that is, the beginning stage of modernization of water mainly during the period of Japanese colonization, the take-off stage from the 1960s to the mid-1980s, the stage of reflexive modernization from the late 1980s to the 1990s, and that of neoliberalization of water since the 2000s. It can be seen that the development of social circulation system of water in Daegu has contributed the increasing urban population and economic development, especially supporting the spatial expansion of the city and the way of modern way of urban life. But the social circulation system of water in Daegu seems to meet with a lot of problems such as relocation of the water intake station, over-equipment of filtration plants, distrust on tap water, inequality of water use, readjustment of water charge, liquid waste from industrial complexes within the urban area, creative destruction of waterfront environment, and privatization of water.

• Archives of design research
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• v.19 no.2 s.64
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• pp.163-172
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• 2006

Sign is one of the important factors in city and national image formation, thus requires high level of quality. However, domestic sign emphasize only the sense of attention that leads to big sized signs, thus often results in a poor coordination with the surrounding space. This situation requires employees in sign business want to learn specialized knowledge about design field. Based on these circumstances, we propose sign design software to employees in sign business field as an aid tool that can help to develop good signs in terms of functionality as well as harmony of design. Thus, in this investigation, sign simulation software application case that can design sign and apply this sign to the actual application site is presented. In order to develop this software, literature survey and preliminary studies were performed to analyze the preparation process and environment, and designed sign design element and software elements, user interrace, and finally Java software were utilized. This developed software can be used as a textbook in sign design related departments in schools, and hopefully to enhance the social recognition of sign as well as academic interest.

• Journal of KIISE:Software and Applications
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• v.31 no.5
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• pp.595-604
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• 2004

Automatic analysis of concepts or semantic relations from text documents enables not only an efficient acquisition of relevant information, but also a comparison of documents in the concept level. We present a multiple cause model-based approach to text analysis, where latent topics are automatically extracted from document sets and similarity between documents is measured by semantic kernels constructed from the extracted topics. In our approach, a document is assumed to be generated by various combinations of underlying topics. A topic is defined by a set of words that are related to the same topic or cooccur frequently within a document. In a network representing a multiple-cause model, each topic is identified by a group of words having high connection weights from a latent node. In order to facilitate teaming and inferences in multiple-cause models, some approximation methods are required and we utilize an approximation by Helmholtz machines. In an experiment on TDT-2 data set, we extract sets of meaningful words where each set contains some theme-specific terms. Using semantic kernels constructed from latent topics extracted by multiple cause models, we also achieve significant improvements over the basic vector space model in terms of retrieval effectiveness.

• Journal of KIISE:Databases
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• v.31 no.6
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• pp.567-584
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• 2004

As XML becomes popular as the way of presenting information on the web, how to secure XML data becomes an important issue. So far study on XML security has focused on security of data communications by using digital sign or encryption technology. But, it now requires not just to communicate secure XML data on communication but also to manage query process to access XML data since XML data becomes more complicated and bigger. We can manage XML data queries by access control technique. Right now current XML data access control only deals with read operation. This approach has no option to process update XML queries. In this paper, we present XML access control model and technique that can support both read and update operations. In this paper, we will propose the operation for XML document update. Also, We will define action type as a new concept to manage authorization information and process update queries. It results in both minimizing access control steps and reducing memory cost. In addition, we can filter queries that have no access rights at the XML data, which it can reduce unnecessary tasks for processing unauthorized query. As a result of the performance evaluation, we show our access control model is proved to be better than other access control model in update query. But it has a little overhead to decide action type in select query.

• Journal of Korean Institute of Industrial Engineers
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• v.41 no.5
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• pp.461-469
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• 2015

The aim of this study is to find out the user's needs of a 3D hand gesture interface in the smart home environment. To find out the users' needs, we investigated which object the users want to use with a 3D hand gesture interface and why they want to use a 3D hand gesture interface. 3D hand gesture interfaces are studied to be applied to various devices in the smart environment. 3D hand gesture interfaces enable the users to control the smart environment with natural and intuitive hand gestures. With these advantages, finding out the user's needs of a 3D hand gesture interface would improve the user experience of a product. This study was conducted using a diary method to find out the user's needs with 20 participants. They wrote the needs of a 3D hand gesture interface during one week filling in the forms of a diary. The form of the diary is comprised of who, when, where, what and how to use a 3D hand gesture interface with each consisting of a usefulness score. A total of 322 data (209 normal data and 113 error data) were collected from users. There were some common objects which the users wanted to control with a 3D hand gesture interface and reasons why they want to use a 3D hand gesture interface. Among them, the users wanted to use a 3D hand gesture interface mostly to control the light, and to use a 3D hand gesture interface mostly to overcome hand restrictions. The results of this study would help develop effective and efficient studies of a 3D hand gesture interface giving valuable insights for the researchers and designers. In addition, this could be used for creating guidelines for 3D hand gesture interfaces.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.506-510
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• 2013

This study aimed to understand relationship between potential risky species and environmental factors at ports in Korea. During the study periods, 25 potential risky species (red tide and toxic species) representing 20 red-tide species, 5 toxic species were observed in the all ports. Skeletonema costatum (red-tide species) was predominated in all study area. This species showed positive correlation with pH, while negative correlation with dissolved oxygen (p<0.05) at Busan port. Also, this species showed positive correlation with total suspended solids and pH (p<0.05) at Ulsan port. However, Sk. costatum showed positive correlation with nitrate at Incheon port (p<0.01). Pseudo-nitzschia spp. producing amnesic shellfish poison (domoic acid) showed positive correlation with nitrate and silicate in all study areas (p<0.05). Alexandrium spp. (paralytic shellfish poison) and Dinophysis acuminata (diarrhetic shellfish poison) were affected by chemical oxygen demand (p<0.01). Our results indicated that red-tide species were affected by physical factors, while chemical factors affected toxic species.