• Journal of Internet Computing and Services
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• v.13 no.6
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• pp.9-16
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• 2012

Social Network Service (SNS) such as Twitter and Facebook has explosively grown nationwide since iPhone was introduced to Korea in 2009. In addition, KakaoStory has recently opened and joined to the SNS market, and it has grown to one of the most popular SNS in the domestic market in a short period of time. Social Network Service supports not only the formation of relationship between SNS users in common interests but also various activities such as management of personal connections and the sharing of information or contents. These three types of SNS have several common functions of sharing and distributing various contents rooted on the personal relationship formed through SNS. As each SNS user has specific reasons for the use of each service, a survey was conducted targeting those who use all of Twitter, Facebook, and KakaoStory was drawn by the statistical analyses of survey answers on users' reasons for each service. This result of study suggests factors to consider in order to exploit a new SNS or to enhance an existing service and can be used as a standard of which SNS for users to select for their own different purposes. It will also provide the basic data for the trust formation, one of the ethics in the upcoming Social Era.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.9
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• pp.1166-1176
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• 1999

연속 매체, 특히 비디오 데이타에 대한 일반 사용자 연산에는 재생뿐만 아니라 임의 속도 탐색 연산, 정지 연산, 그리고 그 외 다양한 연산이 있다. 이 연산 중에서 원하는 화면을 빨리 찾는 데에 유용한 고속 전진(FF: fast-forward)과 고속 후진(FB: fast-backward)은 재생 연산과는 달리 비순차적인 디스크 접근을 요구한다. 이러한 경우에 디스크 부하가 균등하지 않으면 일부 디스크에 접근이 편중되어 서비스 품질이 떨어진다. 본 논문에서는 디스크 배열을 이용한 저장 시스템에서 디스크 접근을 고르게 분산시키기 위하여 '소수 라운드 로빈(PRR: Prime Round Robin)' 방식으로 연속 매체를 디스크에 배치하는 기법에서 문제가 됐던 낭비된 디스크 저장 공간을 신뢰도 향상을 위해서 사용하는 '그룹화된 패리티를 갖는 소수 라운드 로빈(PRRgp: PRR with Grouped Parities)' 방식을 제안한다. 이 기법은 PRR 기법처럼 임의 속도 검색 연산에 있어서 디스크 배열을 구성하는 모든 디스크의 부하를 균등하게 할뿐만 아니라 낭비됐던 디스크 저장 공간에 신뢰도를 높이기 위한 패리티 정보를 저장함으로서 신뢰도를 향상시킬 수 있다. 신뢰도 모델링 방법으로 조합 모델과 마르코프 모델을 이용해서 결함발생율과 결함복구율을 고려한 신뢰도를 산출하고 비교.분석한다. PRR 기법으로 연속 매체를 저장하고 낭비되는 공간에 패리티 정보를 저장할 경우에 동시에 두 개 이상의 결함 발생 시에 그 결함으로부터 복구가 불가능하지만 PRRgp 기법에서는 약 30% 이상의경우에 대해서 동시에 두 개의 결함 발생 시에 저장한 패리티 정보를 이용한 복구가 가능할 뿐만 아니라 패리티 그룹의 수가 두 개 이상인 경우에는 두 개 이상의 결함에 대해서도 복구가 가능하다.Abstract End-user operations on continuous media (say video data) consist of arbitrary-rate search, pause, and others as well as normal-rate play. FF(fast-forward) / FB(fast-backward) among those operations are desirable to find out the scene of interest but they require non-sequential access of disks. When accesses are clustered to several disks without considering load balance, high quality services in playback may not be available. In this paper, we propose a new disk placement scheme, called PRRgp(Prime Round Robin with Grouped Parities), with enhanced reliability by using the wasted disk storage space in an old one(PRR: Prime Round Robin), in which continuous media are placed on a disk array based storage systems to distribute disk accesses uniformly. The PRRgp can not only achieve load balance of disks consisting of a disk array under arbitrary-rate search like PRR, but also improve reliability by storing parity information on the wasted disk space appropriately. We use combinatorial and Markov models to evaluate the reliability for a disk array and to analyze the results. When continuous media like PRR are placed and parity information on the wasted disk space is stored, we cannot tolerate more than two simultaneous faults. But they can be recovered by using stored parity information for about 30 percent as a whole in case of PRRgp presented in this paper. In addition, more than two faults can be tolerated in case there are more than two parity groups.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.6
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• pp.2604-2611
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• 2013

The Personal Rapid Transit(PRT) system has been highly interested in future transportation developments due to its on-demand and optimized door-to-door transport capability. However, the major impediments to the commercialization of PRT are the high cost for construction of infrastructures as opposed to the small transport capacity and difficulty in defining the role of PRT in building a balanced transportation system. In this study, the vertical transfer device for the PRT vehicle is developed to provide more flexible and better compatible urban mobility services between means of transportation, which is expected to meet particular demands in a particular environment. This apparatus was initially designed based on the basis of vertical circulating conveyors with steel chains, which is frequently used in logistics. Its advantages are capable of the non-stop loading and reduced head-way time. Most importantly, it was intensified by the additional idea to ensure the stable and reliable transfer of the PRT vehicle fully loaded with passengers. The 1/10-scale prototype was successfully tested to demonstrate a fundamental mechanism of vertical transfer and identify unexpected user requirements prior to a real manufacturing process.

• The Journal of the Korea Contents Association
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• v.15 no.12
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• pp.106-120
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• 2015

Along with economic growth which affects to the overall increase in income level within society, more permissible leisure time, and change in values of the life style directly affected to the more demand of performance arts. The theaters where the performance contents are actually accomplished have been built with various objectives and now there are 232 of performing art theaters are in operation at various locations over the country. The purpose of this research is to identify behavioral factors regarding how the preferable choice were made from the various type of the performance arts, study for the correlation on post behavior customer based on the survey conducted at Sori Art Center. As a result of this research, there were strong correlation were identified between how the preferable choice were made among the various type of performance and Customer's intend of returning visit /perceivd value. In addition to the aforementioned result, the survey result shows that the excellence of the facility, hospitality level of the staffs, and additional customer services were the meaningful positive factors and user convenience/subsidiary facilities were negative factors to the overall service quality control activities. The research reveals meaningful correlations between quality of the customer service factors and how the preferable choice were made by customer that lead to strategic plan which will increase competitiveness of the Sori Art Center. Extensive research for the Sori Art Center which represents cultural power of the local community would be exemplary case not only for the art centers in metropolitan area but also other local areas within the country.

• The Journal of the Korea Contents Association
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• v.11 no.11
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• pp.49-61
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• 2011

In recent, library is considered as an integrated knowledge convergence center that can respond to various requests about information service of users. Therefor it is necessary to establish a novel information system based on information communications technologies of the era. In other words, it is currently required to develop mobile information service available in portable devices such as smart phones or tablet PCs, and to establish information system reflecting cloud computing, SaaS, Annotation, and Library 2.0 etc. In this paper we design and implement a library information system using collective intelligence and cloud computing. This information system can be adapted for the varieties of mobile service paradigm and abruptly increasing amount of electronic materials. Advantages of this concept model are resource sharing, multi-tenant supporting, configuration, and meta-data supporting etc. In addition it can offer software on-demand type user services. In order to test the performance of our system, we perform an effectiveness analysis and TTA authentication test. The average response time corresponding to variance of data reveals 0.692 seconds which is very good performance in timing effectiveness point of view. And we detect maturity level-3 or 4 authentication in TTA tests such as SaaS maturity, performance, and application programs.

• The Journal of the Korea Contents Association
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• v.15 no.6
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• pp.33-42
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• 2015

As smart phones have been increasingly used to access information with bigger screens and higher resolution, smart phones have rapidly grown larger. Even Apple which had stuck to the 4-inch smart phone screen size, released 5.5-inch iPhone 6 plus. In this trend of smart phone enlargement, manufacturers have mostly incorporated one-handed modes to 5-inch or larger phones to keep the convenience of one-handed operation. But most of them provide just smaller screens and are rather complicated to set up after several menus to touch. In this study, this research examined one-handed functions of each smart phone manufacturer to understand problems in the one-handed smart-phone manipulation of web-browsing which is one of the frequent smart phone services. And by investigating smart phone users, this research found out requirements for one-handed web search operation. Based on this examination, the author of this research designed an efficient one-handed interface for mobile web-search without reducing the screen size. Then, to assess the possible usability improvement, the prototype was applied to a large 5.5-inch-screen smart phone to evaluate its performance through observation and surveys and find out manipulation satisfaction and further improvements.

• Korean Journal of Agricultural and Forest Meteorology
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• v.6 no.2
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• pp.140-147
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• 2004

Agrometeorological information is essential in many agricultural decisions if it reaches the user in a timely and appropriate manner. Agriculture is the backbone to local, regional, and global economic development. Thus, strengthening agrometeorological application to diverse agricultural sectors will benefit economic development. This paper discusses three distinct organizational minions that all share the same need for improved information technology. The World Meteorological Organization's (WMOs) Commission for Agricultural Meteorology (CAgM) has global responsibility for improved agrometeorological services of Members to aid agricultural production and to conserve natural resources. The United States Department of Agriculture, World Agricultural Outlook Board, publishes monthly World Agricultural Supply and Demand Estimates, considered to be a benchmark for both government and industry in production and trade decisions. The National Drought Policy Commission (NDPC), created by an act of the United States Congress, formulated a national drought policy based on preparedness rather than on crisis management. All three organizations recognize the need for IT applications in agricultural meteorology and have been active in implementing this technology. The development of information technology offers new means of dissemination of agrometeorological products. World Agrometeorological Information Service (WAMIS) has taken advantage of the global Internet application to offer WMO Members a dedicated web server to host agrometeorological bulletins and training modules.

• Journal of Internet Computing and Services
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• v.17 no.3
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• pp.95-106
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• 2016

The purpose of this study was to examine how college students use Facebook and the ways in which they feel of commitment while using Facebook. The Big Five Personality Model has been considerably used in the psychology fields, and the researchers have started to explore the role of characteristic factors in influencing an individual's use of social media, such as Facebook which has become one of the most popular social networking site in the world. Therefore, the current study aims to specify the links between The Big Five Personality Model and usage patterns as well as commitment of Facebook. Two hundreds thirty five college students participated in a survey and the results are as follows: First, participants who were high in extraversion and agreeableness were more likely to do information sharing activities such as sharing posts to their friends, writing comments on the other's posts. In addition, participants who were high in openness to experience, conscientiousness, and neuroticism were more likely to do information producing activities including offering events, group, or public pages to meet people both on and offline. Second, in terms of the relationship between personality traits and commitment to the Facebook, the study found that extraversion and neuroticism were related to users' commitment to Facebook. These findings are consistent with the existing literature regarding extraversion and neuroticism were representative personality factors when it comes to commitment of media. Specifically, the study found that those who were high in neuroticism were more likely to produce information such as posting photos repeatedly or tagging their friends on posts, and also more likely to feel commitment on Facebook. These findings confirm that personality is a highly relevant factor in determining individual's behavior and the degree of commitment on Facebook. Based on these findings implications and limitations of the study are discussed.

• Journal of Internet Computing and Services
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• v.20 no.6
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• pp.55-63
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• 2019

Recently, the use of real-world image data has been increasing to express realistic virtual environments in various application fields such as education, manufacturing, and construction. In particular, with increasing interest in digital twins like smart cities, realistic 3D urban models are being built using real-world images, such as aerial images. However, the captured aerial image includes shadows from the sun, and the 3D city model including the shadows has a problem of distorting and expressing information to the user. Many studies have been conducted to remove the shadow, but it is recognized as a challenging problem that is still difficult to solve. In this paper, we construct a virtual environment dataset including the height map of buildings using 3D spatial information provided by VWorld, and We propose a new shadow detection method using height map and deep learning. According to the experimental results, We can observed that the shadow detection error rate is reduced when using the height map.

• Journal of Internet Computing and Services
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• v.18 no.6
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• pp.137-144
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• 2017

A variety of customized marketing strategies are being implemented in the telecommunications market, including the offering of gifts to consumers, as competition in the market is being restructured with the focus on bundled products. However, the Korea Communications Commission (KCC) has recently imposed fines for user discrimination on telecommunication carriers whose marketing strategies have included the award of excessive prizes. In that regard, various issues related to the suitability and appropriate limit of the current gift regulation in the telecommunications market have been raised. Since the Fair Trade Commission, which had a similar scheme to that of the KCC, abolished the regulation on gifts in July 2016, disputes have arisen as to whether the current regulation on gifts is practically effective from the perspective of consumer benefit. In other words, discussions on the rationality of the theoretical and empirical grounds for the regulation on gifts only in the telecommunication market but not in other commodities markets have begun. As such, this study aims to empirically analyze the suitability of the current regulation on gifts in the domestic telecommunications market under the new competitive environment centered on bundled products, and to seek the rational improvement of, and infer the implications for, the regulation on gifts in the telecommunications market based on the results of the analysis.