• Journal of Advanced Marine Engineering and Technology
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• v.39 no.7
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• pp.744-753
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• 2015

This paper presents the results of research on developing marine unified communications to provide VoIP service based on marine satellites. With the recent popularity of smart-phones and other mobile devices, the demand for Internet-based wired and wireless unified technology has been growing in marine environments, and increasing interest is being directed to VoIP products and service models with high price competitiveness and the ability to deliver a variety of services. In this regard, this research designed three instruments, developed their unit modules, and verified their performances. These three instruments included the following: (1) a marine VoIP module equipped with an analogue gateway that can be linked to the existing devices used in vessels, which is more than 80% smaller than that of a land system; (2) a text/voice/video engine for marine satellite communications that runs on technology that minimizes communication data usage, which is a core technology for a marine VoIP service; and (3) a unified communication service that can support multilateral cloud-based message conversations, telephone number-based call functions, and voice/video calling between a private space in a ship and shore.

• The KIPS Transactions:PartC
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• v.13C no.7 s.110
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• pp.889-896
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• 2006

ATM Forum has defined a guaranteed frame rate (GFR) service to serve Internet traffic efficiently. The GFR service provides virtual connections (VCs) for minimum cell rate (MCR) guarantees and allows them to fairly share the residual bandwidth. And ATM Forum has recommended a frame-based generic cell rate algorithm (F-GCRA) as a frame classifier, which determines whether an Am cell is eligible to use the guaranteed bandwidth in a frame level. An ATM switch accommodates cells in its buffer or drops them in a frame level according to current buffer occupancy. A FIFO shared buffer has so simple structure as to be feasibly implemented in switches, but has not been able to provide an MCR guarantee for each VC without buffer management based on per-VC accounting. In this paper, we enhance the F-GCRA frame classifier to guarantee an MCR of each VC without buffer management based on per-VC accounting. The enhanced frame classifier considers burstness of TCP traffic caused by congestion control algorithm so as to enable each VC to use its reserved bandwidth sufficiently. In addition, it is able to alleviate the unfairness problem in usage of the residual bandwidth. Simulation results show that the enhanced frame classifier satisfies quality of services (QoSs) of the GFR service for the TCP traffic.

• Journal of Broadcast Engineering
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• v.18 no.2
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• pp.215-224
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• 2013

With the rising popularity of smart-phones, the supply of Internet protocol television is largely increased and it causes the wireless communication network load to be increased. To overcome such an overloading problem, 3GPP is now working on the standardization of MBMS since LTE Release 6 specification. MBMS has good performance in bandwidth efficiency by sharing the same bandwidth with the mulitple MBMS users having the same content. According to the proposed algorithm, in heterogeneous networks having a dispersed Single-cell MBMS where 3GPP network and Wi-Fi network are mixed, if the number of MBMS users, who are belonging to cells supporting a dispersed Single-cell MBMS, is more than a specified threshold, the MBMS priority policy is operated. Otherwise, the Wi-Fi priority policy is executed. As the simulation results show both the increase of total available bandwidth ratio and the decrease of network usage cost, it is confirmed that the proposed scheme allows the network efficiency to be maximized.

• The Journal of the Korea Contents Association
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• v.12 no.9
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• pp.500-511
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• 2012

Recently, use frequency for traffic information which provides shortest paths and traffic condition is increasing. Specially, in the survey, it is shown that users prefer internet portal sites which can be used the most easily among traffic information media. But, there are not many verification systems for traffic information contents of internet portal sites which collect and provide information than traffic information contents which are provided by public service. The purpose of this study is to investigate real accuracy and accuracy felt by users about information provided by portal sites. Therefore, in this research we verified accuracy of information by portal site with real field data and investigate real usage about contents and experienced accuracy by users through survey. Also, users' expectation and satisfaction were surveyed and the contents to be improved were selected by using IPA technique. By the result of accuracy verification by field data using portable DSRC(Dedicated Short Range Communication) devices, it is shown that average error was 14~32% and sometimes very high rate. Also, it is shown that 28.3 % of total respondents prefers the information by portal sites and 50 % of total respondents felt that contents of traffic information by portal sites are not accurate. Real-time traffic condition was selected as the most inaccurate one among all contents of traffic information and it was analyzed that intensive efforts for improving information about real-time traffic condition are needed.

• Management & Information Systems Review
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• v.38 no.3
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• pp.97-112
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• 2019

Currently, in China, mobile live broadcasts are more popular compared to online live broadcasts. Accordingly, this research focused on Wanghong, SNS's flagship live broadcasting app. In other words, Wanghong refers to an internet celebrity who acts online on social network services (SNS) influencing many other people. This study specifically focused on one social network service and conducted a study on live app users. The study first analyzed the quality factors of an SNS to users using China's live app. Secondly, the research investigated in finding out the impact of quality on the satisfaction of live app users and how this affects the live app user's satisfaction on their intention of continuous use. Studies have shown that information quality, system quality, and social quality among SNS quality have a positive influence on live app user satisfaction. However, the quality of service and the quality of emotion was rejected by the hypothesis. Throughout this study, we hope to create an app that allows users to share more satisfying mobile images, thereby establishing various episodes holding beautiful places of their life on a real-time basis. It is hoped that live broadcasting businesses will spread a significant impact around the world. Finally, in the future, research on the study of collective comparison between Korea and China on SNS is believed to be meaningful.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.10
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• pp.2316-2322
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• 2013

Due to the development of ICT, with using hardwares such as WiFi, 3G and GPS and so on, smartphone could have provided a lot of applications with novel functions rapidly. Through such applications, lots of personal information such as personal location, personal images, and list of phone calls is created, saved and widely used. Because there is lots of leakage of the stored personal information due to loss of phone and application, privacy violation have been important issue nowadays. Smartphone with GPS and Internet provides location information. To protect the information, the technologies that only the authorized user can access it while inquiring the location information have been proposed. In this paper, to minimize the identification information for location information subject and information user and anonymize the identifiable information such as phone number, we proposed a model that can reduce the leakage of information and avoid the wrong usage of the stored information in the server. This technique will be used for protecting privacy when developing the application that provides routing service through location history information.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2001.01a
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• pp.330-335
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• 2001

The occurrences of occupational illness and injury have been seriously underestimated in Korea. Surveillance systems for occupational diseases have recently emerged as important strategies for the control of occupational hazards and the implementation of intervention programs to protect workers. However, health service providers do not actively diagnose occupational diseases and are unwilling to report occupational diseases. With the rapid growth of Internet usage in Korea, the computer network has become the predominant means of communicating and sharing information. Therefore, we developed a web-based updated information and education network to assist the health services providers in reporting occupational diseases. Information systems for occupational disease surveillance were also designed to support occupational disease reporting. Commonly available database systems, such as web databases, are useful to manage occupational diseases data efficiently. Standardized case definitions and report guidelines were also established, which included cumulative trauma disorder, occupational asthma, occupational contact dermatitis, and occupational cancer. This system may provide the basis of an efficient and continuously updated source of educational information and provide specific information concerning the occurrence of occupational diseases in specific areas. Background information on occupational diseases obtained in this way will be invaluable for preventing hazards and enforcing occupational disease prevention programs. Moreover, our experiences in establishing these information systems will be of great use in other countries and settings.

• Journal of the Korean Society for information Management
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• v.23 no.3 s.61
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• pp.91-125
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• 2006

Recent advancements in information technology and the Internet have caused an explosive increase in the information available and the means to distribute it. However, such information overflow has made the efficient and accurate search of information a difficulty for most users. To solve this problem, an information retrieval and filtering system was developed as an important tool for users. Libraries and information centers have been in the forefront to provide customized services to satisfy the user's information needs under the changing information environment of today. The aim of this study is to propose an efficient information service for libraries and information centers to provide a personalized recommendation system to the user. The proposed method overcomes the weaknesses of existing systems, by providing a personalized hybrid recommendation method for multimedia contents that works in a large-scaled data and user environment. The system based on the proposed hybrid method uses an effective framework to combine Association Rule with Collaborative Filtering Method.

• Journal of the Korea Society of Computer and Information
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• v.16 no.4
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• pp.93-99
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• 2011

Recently, the development of internet technology makes user's personal data used by being saved in USB. But there is a critical issue that personal data can be exposed with malicious purpose because that personal data doesn't need to be certificate to use. This paper proposes USB security framework to prevent a duplicate use of personal data for protecting the data which in USB. The proposed USB security framework performs certification process of user with additional 4bite of user's identification data and usage choice of USB security token before certification data when the framework uses USB security product in different network. It makes communication overhead and service delay increased. As a result of the experiment, packet certification delay time is more increased by average 7.6% in the proposed USB security framework than simple USB driver and USB Token, and procedure rate of certification server on the number of USB is also increased by average 9.8%.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.5
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• pp.1077-1084
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• 2017

In this paper, we propose a electrical safety management architecture based on IoT (Internet of things) platform, especially IoTivity which is open source platform organized by OCF. With the advent of various ICT technologies, researches on convergence between power facilities and ICT technology are actively under way. The application of ICT technology to high voltage electrical equipment has been studied in terms of improving power efficiency and measuring accurate usage in real time. We focused on safety data and described the components of the electrical safety architecture, the requirement of reference interface, and available services. We defined the data profile for the electrical facilities subject to electrical safety management and examined feasibility through testing.