• The KIPS Transactions:PartC
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• v.18C no.3
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• pp.143-150
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• 2011

The adoption of VoIP is continuously increasing in public institutions, private enterprises and households due to cheaper cost and various supplementary services. Also, it is expected to spread widely the use of VoIP in mobile environment through the increasing use of smartphone. With the growing concern over the incidents of VoIP service while the VoIP service has become increasingly. Especially eavesdropping, it is possible to invade user privacy and drain the secret of company. So, it is important to adopt the protocols for VoIP secure communication. VoIP security protocols are already adopted in public institutions, but it is not adopted in private enterprises and households. In addition, it is necessary to verify whether the VoIP security protocol could be adopted or not in mobile VoIP due to its limited computing power. This paper compared the VoIP security protocol under fixed network and mobile network through performance evaluation. Finally, we found that it is possible to adopt the VoIP security protocols in mobile network.

• Journal of Internet Computing and Services
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• v.4 no.5
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• pp.11-19
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• 2003

Since B2C(Business to Customer) from which e-commerce had originated was replaced by B2B, e-Business has shown fast growth so fa., Recently, e-Procurement by l:n concept is on the development as self-purchase system associated with their own ERP In many conglomerates in the Korean market. However, in order to vitalize e-Biz in the plant industry, we need to set up e-marketplaces where many sellers and buyers can meet each other at the same time, which has become the essential part for success as an expanded business model. In this paper, we expect that the foundation for e-transformation in the plant industry is set up by developing Purchase Process System and related modules as the prerequisite for e-Biz in the plant industry, and this report will provide an exemplary model for e-commerce. The Purchase Process System consists of 1) e-Purchasing Module that manages bidding and contract information based on quotation inquiry, 2) e-Expediting Module that manages information to guarantee the on-time delivery, 3) e-Certification Module that controls user authentification, 4) e-Basic Module that manages the bulletin boards, Q&A, etc.

• Journal of KIISE:Computing Practices and Letters
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• v.10 no.4
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• pp.328-336
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• 2004

Recently a mobile service is changing into a system environment that offers the customer various contents service. Representative example of service is a Calling Identity Del ivory Service(CID). Such service has the problem in the case which the receiver cannot remember the phone number of the sender; it has a difficult problem that cannot easily confirm whose the phone number it is. Therefore, it is desirable to design and implement visual services that can enhance the recognition of users. In this paper, we propose the architecture that is similar to a Calling Identity Delivery Service. We propose the architecture for communication service and system that is able to visually display the information of the sender using 2D image data in mobile environment. After that we set the image information to represent the user and this method is able to visually display the information of the sender by transmitting an image data through channels from switch station or base station using the server. When the receiver receives a phone call from the sender, this method provides an efficient service by transmitting visual data with bell sound. That is, the image information of sender is appeared on liquid crystal display(LCD) of the receiver at the same time. We investigate the concepts for processing real-time transmission of image data and describe an example of the implementation result that is based on system. This technology has a potential influence on the marketing and presents an efficiency of this method.

• Journal of Intelligence and Information Systems
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• v.13 no.2
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• pp.27-41
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• 2007

Nowadays the context-aware systems have been regarded as a promising opportunity to create differentiated e-marketplaces. Context-aware system aims to provide personalized services by understanding the user's current situation which is automatically acquired from the context data. This aim naturally leads us to a motivation to evaluate to what extent a system is context-aware. Even though lots of endeavors have stated about the level of context-aware system, a structured evaluation has been so far very rare. Hence, the purpose of this paper is to propose a two-phased methodology for assessing context-aware systems. In the first phase, we perform a requisite analysis to discriminate a context-aware system from general or context-based systems. Once an information system is recognized as context-aware system, then level of collaboration, mobility and embeddedness is derived to determine the level of context-aware system in the second phase. To do so, device collaboration diagram (DCD) is proposed to visualize the system architecture. Moreover, readiness and level of system are Jointly considered in the phase to provide a development strategy for each context-aware system development project. To show the feasibility of the idea proposed in this paper, legacy context-aware systems are actually analyzed and evaluated.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.21 no.3
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• pp.151-163
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• 2010

It is necessary, due to changes in the information environment, to investigate problems in existing information retrieval systems. Ontologies and social tagging, which are a relatively new means of information organization, enable exploratory discovery of information. These two connect a thought of a user with the thoughts of numerous other people on the Internet. With these connection chains through the interactions, users are foraging information actively and exploratively. Thus, the purpose of this study is, through qualitative research methods, to identify numerous discovery facilitators provided by ontologies and social tagging, and to create an exploratory discovery model based on them. The results show that there are three uppermost categories in which 5, 4 and 4 subcategories are enumerated respectively. The first category, 'Browsing and Monitoring,' has 5 sub categories: Noticing the Needs, Being Aware, Perceiving, Stopping, and Examining a Resource. The second category, Actively Participating, has 4 categories: Constructing Meaning, Social Bookmarking and Tagging, Sharing on Social Networking, Specifying the Original Needs. The third category, Actively Extends Thinking, also has 4 categories: Social Learning, Emerging Fortuitous Discovery, Creative Thinking, Enhancing Problem Solving Abilities. This model could contribute to the design of information systems, which enhance the ability of exploratory discovery.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.6
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• pp.815-821
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• 2021

This study addresses on the design of performance monitoring system for the time synchronization service of the enhanced long-range navigation (eLoran) system, which has a representative ground-wave radio broadcast system capable of providing positioning, navigation, timing and data (PNT&D) services. The limitations of time-synchronized systems due to the signal vulnerabilities of the global navigation satellite system (GNSS) are explained, and the performance monitoring system for the eLoran timing service as a backup to the GNSS is proposed. The time synchronization service using eLoran system as well as system configurations and the user requirements in the differential Loran (dLoran) system are described to monitor the time synchronization performance. The results of the designed system are presented for long-term operation in the eLoran testbed environment. As the results of time performance monitoring, we were able to verify the time synchronization precision within 43.71 ns without corrections, 22.52 ns with corrections. Based on these results, the eLoran system can be utilized as a precise time synchronization source for GPS timing backup.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.5
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• pp.919-939
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• 2021

As a next-generation communication technology, 5G networks are capable of handling large amounts of traffic based on higher speeds, shorter communication delays, and higher connectivity compared to 4G networks. In this 5G network environment, base stations are installed all over the city at high density due to their characteristics, and are connected to user terminals to provide services. Therefore, if the base station is damaged by a malicious attacker, it is expected to cause great damage to users and society as a whole. So the need for secure communication equipment such as 5G base stations has emerged. Therefore, in this paper, we propose the security functional requirements derived using threat modeling, a systematic methodology for 5G base stations, and the security assurance requirements at the level that can cope with the backdoor issues. The security requirements proposed in this paper can be used for base station design and development to construct a secure network environment as a security evaluation standard for 5G base stations.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.9 no.7
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• pp.707-722
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• 2019

The concept of neighborhood parks has been used as the principle of forming a community in our society going through modern and contemporary times. The concept of neighborhood parks equipped with physical facilities has been discussed constantly regarding the roles and meanings of them. This study focuses on pocket parks which have been playing roles in improving environment through regeneration and forming regional communities based on that as neighborhood facilities. This author carried out field investigation on total 72 Hanpyeong Park and Hanpyeom Parks formed in the capital area and examined the significance of planning them and also their utility and residents and users' attachment to them through a survey. In this process, this researcher has been able to draw following conclusions. First, according to the demographic characteristics of users, there is significant difference found by groups in terms of their place attachment to the parks. This implies that difference in the major types of residences supplied these days influences their intention to experience ecological space. Second, according to their educational background, there is significant difference found by groups regarding their place attachment to the parks. Third, according to user behavior, there are differences found in their place attachment to the parks and also detailed differences found by groups in terms of the frequency of use and duration of stay.

• Journal of Internet Computing and Services
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• v.20 no.2
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• pp.109-118
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• 2019

The purpose of this study is to deliver both market-practical and civil-centric political implication for sharing economy by investigating the nature of consumer-adoption for car-sharing service. With the global interest and market proliferation of the sharing economy, various service models for sharing idle resources have also been released in Korea. Particularly, in case of car sharing service, public - private partnership projects are spreading rapidly in various local governments including Seoul, along with the growing demand for alternative transportation system centering on the urban area. This study conducted an empirical study on the process of accepting the car sharing service by analyzing the data collected from users of the car sharing service "Sharing Car(Nanum Car)" of Seoul Metropolitan Government. A survey was conducted on 281 users in their twenties who are in the age of main use among the experienced users of the "Sharing Car(NaNum)" residing in Seoul. The result of analysis on the relationship between these users' perceived value and intention to use the vehicle sharing service would provide implications for establishing consumer(citizen)-centeric policies as well as market implications.

• The Korean Journal of Archival Studies
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• no.70
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• pp.157-187
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• 2021

Broadcasting and audiovisuals are the easiest audiovisuals to access in everyday life and are shared through the media by recording the times. Overseas, independent broadcasting and audiovisual archives are already in operation under the legal system. As the domestic broadcasting and audiovisual industries continue to grow in size and are drawing global attention, the establishment and operation of public broadcasting and audiovisual archives need to be discussed in more detail. In particular, it is clear that the legal device is a task that must be preceded as the basis for the establishment of public broadcasting and audiovisual archives. To this end, this study first looked at the Digital Archive Center, which was operated in the 2000s. In addition, the cause of the dismantling of the Digital Archive Center was considered as the absence of a legal device, and the case of the Institut national de l'audiovisuel(INA), which has been operating on a legal basis for a long time, was investigated. INA is a representative example of implementing a lead-based system in the broadcasting and audiovisual fields, and has been introduced several times through previous studies, but tends to be focused on user services. Therefore, in this study, the analysis was focused on legal factors supporting the operation of INA. Finally, in order to realize the Public Broadcasting and Audiovisual Archive discussed in the previous study, I would like to suggest a legal device for the establishment of Public Broadcasting and Audiovisual Archive in Korea.