• The Journal of Korean Association of Computer Education
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• v.20 no.2
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• pp.57-65
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• 2017

The world's senior population is on the rise. In particular, unlike the past seniors who were in the digital insensitivity class, the smart seniors who want to continue to use smart devices and the Internet are emerging. Although the definition of senior is merely defined as a senior group, research on the characteristics of seniors has been done in psychology studies, but research using data based senior cognitive response is only at an early stage. In order to provide contents according to the cognitive characteristics of Smart Senior, there is a need to classify the cognitive characteristics of Smart Senior well. Therefore, this paper suggests a data - driven senior cognitive response modeling method that helps the enjoyment of culture for seniors through classification of cognitive responses to smart seniors.

• Journal of KIISE
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• v.44 no.6
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• pp.613-620
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• 2017

Skyline queries are used extensively to solve various problems, such as in decision-making, because they find data that meet a variety of user criteria. Recent research has focused on skyline queries by using the MapReduce framework for large database processing, mainly in terms of applying existing index structures to MapReduce. In a skyline, data closer to the origin dominate more area. However, the existing index structure does not reflect such characteristics of the skyline. In this paper, we propose a grid-block structure that groups grid cells to match the characteristics of a skyline, and a two-level grid-block structure that can be used even when there are no data close to the origin. We also propose an efficient skyline-query algorithm that uses the two-level grid-block structure.

• Journal of Digital Convergence
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• v.14 no.4
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• pp.193-200
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• 2016

This study is focused on analyzing the tourism social media channel importance of Trytoursumer. On the basis of previous studies, the factors were divided into tourism communication, tourism cooperation, tourism contents sharing, tourism entertainment. As a result of the empirical analysis using AHP, Analytic Hierarchy Process, tourism communication relatively appeared as the most important factor. And order showed that the high importance of such tourism content sharing, tourism entertainment, tourism cooperation. Also, there was the highest priority of social networking in the area of tourism communication among 14 types of total evaluation factors regarding priority, followed by social news in the area of tourism cooperation, and micro-blog in the area of tourism communication. Analysis result, may contribute to the increase of social media channels effectiveness and strategy of application in social media channel of Trytoursumer.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.6
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• pp.21-35
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• 2022

With the support of local and central governments, various incentive policies for "green" cars have been established, and the number of electric vehicle users has been rapidly increasing in recent years. As a result, much attention is being given to establishing a user-centered charging infrastructure. A standard for the number of electric vehicle chargers to be supplied is being prepared based on building characteristics, but there is quite limited research on the appropriate ratio of slow and fast chargers based on the characteristics of each place. Therefore, this study derived an appropriate penetration ratio based on data about the distribution ratio of common slow chargers. These data were collected using a survey of actual electric vehicle users. Next, an analysis was done on how to categorize the needs of charging environments and to determine what criteria or characteristics to use for categorization. Based on the results of the survey analysis, three types of places were derived. Type-1 places require 10% of chargers to be slow chargers, Type-2 places require 40-60% of chargers to be slow chargers (i.e., around equal distribution of slow and fast chargers), and Type-3 places require more than 80% of chargers to be slow chargers. The required levels of slow chargers were classified by place type and by individual using latent class cluster analysis, which made it possible to categorize them into five clusters related to socioeconomic variables, vehicle characteristics, traffic, and charging behaviors. It was found that there was a high correlation between charging behavior, weekend travel behavior, gender, and income. The results and insights from this study could be used to establish charging infrastructure policies in the future and to prepare standards for supplying charging infrastructure according to changes in the electric vehicle market.

• The KIPS Transactions:PartC
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• v.15C no.6
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• pp.573-586
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• 2008

The improved performance and miniaturization of computer and the improvement of wireless communication technology have enabled the emergence of many high quality services. Among them multicast services are receiving much attention and their usage is increasing due to the increase of Internet multimedia services such as video conference, multimedia stream, internet TV, etc. Security plays an important role in mobile multicast services. In this paper, we proposed a secure multicast protocol for a hierarchical micro-mobility environment. The proposed secure multicast protocol provides security services such as authentication, access control, confidentiality and integrity using mechanisms including symmetric/asymmetric key crypto-algorithms and capabilities. To provide forward/backward secrecy and scalability, we used sub-group keys based on the hierarchical micro-mobility environment. With this security services, it is possible to guard against all kinds of security attacks performed by illegal mobile nodes. Attacks executed by internal nodes can be thwarted except those attacks which delete packet or cause network resources to be wasted. We used simulator to measure the performance of proposed protocol. As a result, the simulation showed that effect of these security mechanisms on the multicast protocol was not too high.

• Journal of KIISE:Information Networking
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• v.29 no.3
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• pp.253-264
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• 2002

Recently, hierarchical architectures of databases for location management have been proposed in order to accommodate the increase in user population in future personal communication systems. In particular, a 3-level hierarchical database architecture is compatible with current cellular mobile systems. In the architecture, a newly developed additional databases, regional location database(RLR), are positioned between HLR and VLRs. We propose an efficient cache scheme, called the Double T-thresholds Location Cache Scheme. The cache scheme extends the existing T-threshold location cache scheme which is competent only under 2-level architecture of location databases currently adopted by IS-41 and GSM. The idea behind our scheme is to use two pieces of cache information, VLR and RLR serving called portables. The two pieces are required in order to exploit root only locality of registration area(RA) but also locality of regional registration area(RRA) which is the wide area covered by RLR. We also use two threshold values in order to determine whether the two pieces are obsolete. In order to model the RRA residence time, the branching Eralng-$\infty$ distribution is introduced. Our minute cost analysis shows that the double T-threshold location cache scheme yields significant reduction of network and database costs for molt patterns of portables.

• The Journal of the Korea Contents Association
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• v.22 no.5
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• pp.15-25
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• 2022

This study aims to identify the family and lineage of a part of a "Fish Tribe Conference" in the section Tokkijeon by utilizing computer literature analysis techniques. First of all, we encode the classification for a pairwise comparison's type of each paragraph to build a corpus, and based on this, we use the Hamming distance to calculate the distance matrix between each classification for a pairwise comparison's. We visualized classification for a pairwise comparison's clustering pattern by applying multidimensional scale method, and hierarchical clustering to explore the characteristics of the 'fish family' line and lineage compared to the existing cluster analysis study on entire paragraphs of "Tokkijeon". As a result, unlike the cluster analysis of the entire paragraph of "Tokkijeon", which consists of six categories, the "Fish Tribe Conference" section has five categories and some classification for a pairwise comparison's accesses. The results of this study are that the relative distance between Yibon was measured and systematic classification was performed in an objective and empirical way by calculation, and the characteristics of the line of the fish family were revealed compared to the analysis of the entire rabbit exhibition.

• Journal of Navigation and Port Research
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• v.28 no.1
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• pp.51-58
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• 2004

Due to the changes in market place, new business types(e.g. e-business} have been rapidly emerged and increased. However, those new business types have not much been emerged in port and logistics related industries, and adoption rate of e-business in this area is very low, compared to other industries. Thus, to promote e-business in this area, many policies have been studied. However, most of previous studies have not been based on industrial structure, and results of these studies have mostly been case by case. Further, there have been no research based on the related theories. As a result, despite many of research and project for shipping and port related e-business, prominent achievements in this area have never to be presented. For these reasons, it am be stated that, first of all, basic studies related to new business types in shipping and port are needed, and then, various policies based on results of those basic studies should be discussed. The aim of this study is to classify business types existed (or expected) in a port related industry, ship bunkering. This taxonomy was based on theories related to business layer(BL) and value chain(VC), and these BL and VC combination enabled to acquire all possible business types.

• 한국노년학
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• v.37 no.3
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• pp.707-726
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• 2017

Korea is proceeding to aging society at much faster pace than other countries. To alleviate various problems (health, environment, social relationships, psychology and emotion, and financial problems) of the elderly caused by aging society, there has been increasing attention to social capital. This study investigated types of ways that the elderly at individual level are aware of social capital and the characteristic. In addition, factors that influence the types were studied. Data from 1060 elderly with the age of 65 and older were collected in Korea. Excluding missing data on variables used in the study, data of 960 elderly were used for analyses. K-mean cluster analysis was conducted to investigate types of elderly awareness on social capital at individual level. Multinominal logistic regression was used to find out factors of the types. K-mean cluster analysis resulted in three types of awareness on social capital among the elderly: (1) potential of social capital; (2) severance of social capital; and (3) wealth of social capital. Multinominal logistic regression resulted in that compared to potential of social capital type, when the elderly were younger, inclination of politics was more progressive, they did not have religion, they did not reside in rural, and they did not live in multiplex housing, the elderly were more likely to be in severance of social capital type. Also, when the elderly were women, had higher education and standard of living, were Christian, and did not reside in rural regions. they tended to be in wealth of social capital type. Based on the study results about awareness on social capital among the elderly and factors related to the awareness types, practical and political suggestions that promote social capital to solve problems of the elderly were provided.

• Journal of Information Technology and Architecture
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• v.11 no.2
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• pp.175-185
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• 2014

This study is based on the information security management system, the threat from mobile office, mobile office configuration item type, vulnerability analysis and control at the level of the current possibilities for technology to its purpose. To perform exploratory study for mobile Office to target the new technology, we were used the integrated research methods such as the documentary survey, expert FGI and real user's survey. To identify the main risk areas of mobile office services, we develop the mobile service layer model that separated the place, terminal, network, server according to service deliverly system. Finally, the result of survey for threats and vulnerabilities showed that the control of the terminal of user is a significant.