• Spatial Information Research
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• v.20 no.2
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• pp.129-136
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• 2012

Recently international organizations such as ISO/TC211, OGC, INSPIRE (Infrastructure for Spatial Information in Europe) make an effort to share geospatial data using semantic web technologies. In addition, smart phone and social networking services enable community-based opportunities for participants to share issues of a social phenomenon based on geographic area, and many researchers try to find a method of extracting issues from that. However, serviceable spatial ontologies are still insufficient at application level, and studies of spatial information extraction from SNS were focused on user's location finding or geocoding by text mining. Therefore, a study of extracting spatial phenomenon from social media information and converting it into geosemantic knowledge is very usable. In this paper, we propose a framework for extracting keywords from micro-blog, one of the social media services, finding their relationships using data mining technique, and converting it into spatiotemopral knowledge. The result of this study could be used for implementing a related system as a procedure and ontology model for constructing geoseem antic issue. And from this, it is expected to improve the effectiveness of finding, publishing and analysing spatial issues.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.3
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• pp.1-9
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• 2016

NSS (Navigation satellite system) provides the information for determining the position, velocity and time of users in real time using satellite-networking, and is classified into GNSS (Global NSS) and RNSS (Regional NSS). Although GNSS services for global users, the exactitude of provided information is dissatisfied with the degree required in modern systems such as unmanned system, autonomous navigation system for aircraft, ship and others, air-traffic control system. Especially, due to concern about the monopoly status of the countries operating it, some other countries have already considered establishing RNSS. The RNSS services for users within a specific area, however, it not only gives more precise information than those from GNSS, but also can be operated independently from the NSS of other countries. Thus, for Korean RNSS, this paper suggests the methodology to design the satellite constellation considering the regional features of Korean Peninsula. It intends to determine the orbits and the arrangement of navigation satellites for minimizing PDOP (Position dilution of precision). PGA (Parallel Genetic Algorithm) geared to solve this nonlinear optimization problem is proposed and STK (System tool kit) software is used for simulating their space flight. The PGA is composed of several GAs and iterates the process that they search the solution for a problem during the pre-specified generations, and then mutually exchange the superior solutions investigated by each GA. Numerical experiments were performed with increasing from four to seven satellites for Korean RNSS. When the RNSS was established by seven satellites, the time ratio that PDOP was measured to less than 5 (i.e. better than 'Good' level on the meaning of the PDOP value) was found to 94.3% and PDOP was always kept at 10 or less (i.e. better than 'Moderate' level).

• Journal of KIISE:Information Networking
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• v.31 no.4
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• pp.384-392
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• 2004

Mobile contents service providers have some difficulties to timely and proper service deployment due to rapid development cycle of diverse portable devices with different capabilities. A way to resolve the problem is to introduce a mobile contents service paltform that can adapt original mobile contents to diverse devices dynamically and automatically. In this paper, we propose a mobile contents service platform based on active network mechanisms, called Mobile Content Adaptation Network(MobiCAN). The MobiCAN node provides effective service deployment, execution, and maintenance features and accommodates service layering and service customization capabilities for easy deployment. The basic functional units of the MobiCAN node are micro services with well-defined service interfaces and service layering features. For reliable services among the MobiCAN nodes, we design new distributed and robust Overlay Management Protocols(OMPs). As an example of practical MobiCAN applications, we finally describe Dynamic Contents Customization Proxy(DCCP) service.

• Journal of the HCI Society of Korea
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• v.7 no.1
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• pp.19-28
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• 2012

Why people share location context information? The purpose of our study is that why users share location context information and which factors is related to co-experiences in LBSNS. Through an exploratory approach, first, we conducted a qualitative study in order to understand experiences among people in LBSNS and analyzed according to Grounded Theory. As a result, we found concepts regarding co-experiences cooperatively and competitively in LBSNS. Second, the theoretical model of co-experience was constructed by mediating perceived empathy based on theoretical foundation. In this study, theoretically, we suggested exploratory research model of co-experiences in LBSNS. Practically, designers could adopt concepts in terms of competition and collaboration among users to build co-experience of LBSNS services as its guidelines.

• Journal of the Korean Society for Library and Information Science
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• v.42 no.2
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• pp.87-108
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• 2008

The purpose of standards and guidelines of library service for people with disability is to provide libraries, governments and other stakeholders with a framework for developing library services for people with disability. This Paper is to Identify the constituents of standards and guidelines of library service for people with disability. These constituents are developed by analysis and investigation of foreign standards and are based on many people's advice such as members of the advisory committee. Extracted constituents of standards and guidelines of library service for people with disability are as follows: physical accessibility to library building and facilities, construction of alternative formats, access to services and programs. assistance engineering devices, web accessibility and universal design, training and staff development, cooperation and networking etc. Finally, we clarified main contents of each element to be included in standard.

• Asia pacific journal of information systems
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• v.26 no.3
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• pp.367-384
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• 2016

Social networking services (SNS) have become a significant platform for Internet users to obtain knowledge and information. Users can share messages mutually via this platform. This kind of sharing enables users to exchange and gain useful information. However, in recent years, the crisis of stickiness has appeared in SNS, calling attention to the social network industry. Relevant professionals explain that the interest of users in sharing knowledge on SNS websites and applications may gradually decrease, eventually leading to users giving it because the platforms utilize simple and uninteresting methods to attract active participation from users. However, factors affecting the knowledge sharing on SNS websites and applications should be identified clearly through studies. Sina Weibo is one of the largest SNS platforms in the world, and studies on the factors affecting knowledge sharing of users could be valuable in addressing this issue. This paper establishes the theoretical analysis model of knowledge sharing in SNS sites and applications, analyzes the factors affecting knowledge sharing on these sites, and proposes the corresponding strategies to address the issues. Using questionnaire surveys on Sina Weibo users, this article will discuss the factors affecting knowledge sharing, and analyze these factors on SNS as well as improve the stickiness of users to achieve the aim of SNS platforms enabling the expansion of the range of users. The study will discuss theoretical foundations and the hypotheses that arise. The method of study will also be discussed. The study concludes with theoretical implications, practical implications, limitations, and future research opportunities. The results of this study could aid researchers in understanding the underlying reasons for social network activities as well as for SNS developers in improving SNS services.

• The KIPS Transactions:PartC
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• v.13C no.5 s.108
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• pp.641-650
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• 2006

There has been a continued increase in the complexity of software equipped with wireless mobile devices, due to the introduction of new device functionality and services via network connection. The increasement expected to be accelerated by convergence of telecommunication and broadcasting, and proliferation of telematics and home networking services using wireless mobile devices. The higher the complexity of mobile device software, the higher the necessity of management for the software. As for the global standard of mobile device management technology, OMA DM has been widely adopted by device manufacture and expected to be accelerated its adoption. In this paper, we present a development result of mobile device software release management system ThinkSync DM SoftMan. The implementation details of ThinkSync DM SoftMan are provided in implementation architecture and its working scenario based on the design of ThinkSync DM SoftMan that is summarized in this paper as our previous work. The conformance and performance test of the system are presented.

• Journal of KIISE:Information Networking
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• v.31 no.6
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• pp.620-632
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• 2004

IP is not suitable for mobile nodes by network-based routing because mobile nodes are dynamically change their network attachment point. Mobile-IP is an IETF standard providing continuous access to the Internet for mobile nodes, but it has the triangle routing problem. Also it has a performance degradation problem by massive packet loss during layer 3 handoff of mobile nodes. Especially, two IETF multicast support schemes for Mobile-IP do not guarantee the quality of realtime multimedia services because they have several problems such as long routing path, packet duplication(hi-directional tunneling) and massive packet loss(remote subscription). In this paper, we propose a lossless remote subscription scheme that guarantees the quality of realtime multimedia services over Mobile-IP. From the result of simulation, we verified that the proposed scheme in this paper can reduce the delay time of remote subscription by the effect of the low latency handoff scheme that is extended to apply to the multicast group management and it requires only 0.58% buffer spaces of the previously proposed lossless remote subscription scheme.

• Journal of the Korea Computer Industry Society
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• v.5 no.3
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• pp.345-354
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• 2004

In these days, such services are popularized as E-commerce, E-government, multimedia services, and home networking applications. Most web traffics generated contemporarily basically use the Hyper Text Transfer Protocol(HTTP). Unfortunately, the HTTP is improper for these applications that comprise significant components of the web traffics. In this paper, we introduce a real-time contents compression architecture that maximizes the web service performance as well as reduces the response time. This architecture is built into the linux kernel-based web accelerating module. It guarantees not only the freshness of compressed contents but also the minimum time delay using an server-state adaptive algorithm, which can determine whether the server sends the compressed message considering the consumption of server resources when heavy requests reach the web server Also, We minimize the CPU overhead of the web server by exclusively implementing the compression kernel-thread. The testing results validates that this architecture saves the bandwidth of the web server and that elapsed time improvement is dramatic.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1428-1445
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• 2008

This study focuses on examination a) of impacts of entrepreneurs' psychological characteristics on business performance (need fur achievement and risk-taking propensity), b) of impacts of entrepreneur's competency characteristics(vision, opportunity recognition, social deftness, frequency of networking and reliability) on business performance, and c) of controlling impacts of business incubator on the relationship between entrepreneurs' characteristics (psychological characteristics and competency) and business performance. According to a study, among entrepreneurs' psychological characteristics, need for achievement has a significant impact on business performance, whereas risk-taking propensity is found to have no significant impact on business performance. In addition, among entrepreneurs' competency characteristics, vision, social deftness, and network reliability have no impact on business performance, whereas opportunity recognition and frequency of network have an impact on business performance. On the other hand, need for achievement has a negative impact on controlling business incubator services. Business incubator services have a significant impact on the relationship between vision, network reliability and business performance.