• The KIPS Transactions:PartA
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• v.8A no.3
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• pp.217-226
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• 2001

In this paper, for continuous media access operations performed by Clustered Continuous Media Storage Server (CCMSS) system, we present the analytical model based on the open queueing network, which considers simultaneously two critical delay factors, the disk I/O and the internal network, in the CCMSS system. And we derive by using the analytical model the stochastic model for the total service delay time in the system. Next, we propose the integrated stochastic admission control model for the CCMSS system, which estimate the maximum number of admittable service requests at the allowable service failure rate by using the derived stochastic model and apply the derived number of requests in the admission control operation. For the performance evaluation of the proposed model, we evaluated the deadline miss rates by means of the previous stochastic model considering only the disk I/O and the propose stochastic model considering the disk I/O and the internal network, and compared the values with the results obtained from the simulation under the real cluster-based distributed media server environment. The evaluation showed that the proposed admission control policy reflects more precisely the delay factors in the CCMSS system.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.9
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• pp.1126-1134
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• 1999

최근 다양한 멀티미디어 서비스를 지원하기 위한 통신망 관리와 서비스 관리가 통합된 개방형 정보 통신망의 구조가 요구되고 있다. 이러한 구조를 기반으로, TINA-C(Tele-communications Information Networking Architecture-Consortium)에서는 분산 환경에서 분산 어플리케이션 객체들에 대한 복잡한 서비스 및 관리 인터페이스들을 간결하도록 객체그룹의 개념을 정의하고 있다. 이러한 환경 속에서 트레이딩 서비스는 통신 서비스를 제공하는 객체그룹간의 상호작용을 지원하는데 매우 중요하다.따라서, 본 논문에서는 객체그룹간의 상호접속을 지원할 수 있는 트레이딩 기능과 이들 트레이더들간의 연동을 위한 트레이더 연합 모델을 제시하고자 한다. 이를 위해 우리는 트레이더의 중개자로서 Cooperator를 설계하여 기존의 트레이더와 연동시켰다. 이러한 결과로서 우리의 새로운 트레이더 연합 모델에서 Cooperator는 객체그룹간의 상호접속에서 객체들의 접속 권한의 체크 기능과 기존의 트레이더 연합모델의 문제점인 트레이더들간의 단 방향 연결문제를 보완하여 양방향 연결 기능을 갖도록 하였다. 끝으로, 이러한 해결 과정을 보이기 위해 트레이더와 Cooperator들로 이루어진 본 연합모델에서 분산 객체그룹간의 상호접속 절차과정과 사건 추적 다이어그램을 보였다.Abstract Recently, the open networking architecture is required to support various multimedia services as integrated functions of network management and service management. Based on this architecture, TINA-C defines an object group concept for simplifying complex management and service interfaces, when distributed application is executed in distributed environments. Within the support environment the trading service is an important of the interacting object groups which provide a telecommunication service.Hence, we suggest the trader federation model for supporting interconnections between object groups and among existing traders by using the cooperator we designed, as an intermediator among traders. Our cooperator has functions for checking access rights of objects in object groups, and for providing bidirectional linkage among traders. Up to now, the existing trader federation models have a single directional linkage for interactions among traders. Finally, we showed the interface procedure and the event trace diagram of distributed object groups using our model consisted of traders and the cooperators.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.22 no.1
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• pp.11-26
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• 2011

The expectation and the role for the university are rising due to the national competitiveness and change of environment in higher education in the knowledge based society, and the role to realize the effective lifelong study is also underlined in lifelong study society. And the social awareness is also diffused that the university should share the specialized substantial information resource with the community, and ensure the access right to knowledge and information to local inhabitant. Like this, the roll as an information center that the university can develop the local society as the component of the community according to the diffusion of lifelong study and the change of civic awareness. To check the open state of university libraries to community, this study surveyed and analyzed the open state of 4-year-course university libraries in Seoul and Gyoenggi region. On this base, this study emphasized that the university should open its libraries and positively offer the abundant specialized data of university libraries to the local residents. And this study suggested the way that the university libraries can cooperate connecting with the local public libraries and the school libraries as a positive service way of university libraries. Also this study accentuated that the university libraries should establish an open-door policy of its libraries and enlarge the service for the local residents by using the university conditions to maximum with the positive support of the university libraries of government and the university's bureaucracy.

• The Transactions of the Korea Information Processing Society
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• v.3 no.7
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• pp.1812-1821
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• 1996

In this paper, firstly we describe the structure and the performance of our ICPS(Information Communicaion Processing System) which currently provides information retrieval services, and then make a proposal for the construction of the open-networking information communication infra-structure which enables us to fully pre-pare for the emerging information society. In detail, the structure and the methodology needed for the implementation of the billing function on behalf of all information providers by using the user access network number as a user identification number while guaranteeing the equivalent access to the multiple value-added networks, are suggested. Based on the above ideas, the AICPS(Advanced Information Communication Processing System) has been designed and implemented. Final system performance evaluation with the assumption of a poling system as a system model, shows that our system can handle 10,000 user simultaneously who are using V.34 28.8 kbps modems and the processing capacity is 288,000 packet/sec. This result is so far superior to our target performance established during the desingning procedure. Namely, our system was originally designed to accommodate only 960 users at the same time. By taking advantage of this excessive high performance of our system, many other users can easily access the new services which are accessible only throught the ISDN or the Internet.

• Journal of Korean Library and Information Science Society
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• v.53 no.2
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• pp.215-239
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• 2022

All public libraries are local public goods and cultural infrastructures whose ideological pillars are publicly operated, free, and open to all. This identity is justified when the public library provides various knowledge information, various programs, and community space to local residents within the service area, and ultimately contributes to the cultural development of the nation and society. To this end, the country and local governments must expand the number of individuals that meet legal standards, deploy competent professionals, and provide facilities and spaces that are easy to access and use. However, if there is a gap in infrastructure and services between regional public libraries, it causes inequality in access and use of residents, which inevitably leads to information gap and cultural welfare gap. Therefore, this study was analyzed the relative gap using the location quotient, key infrastructure indicators and service indicators of public libraries of regional government in Korea and basic local government in the Chungnam region from the viewpoint that the balanced development and capacity building of public libraries must precede the establishment of a public library in Chungnam region as a life-friendly knowledge information service institution, culture enjoyment and lifelong learning space. Based on the results, a method to resolve the gap was suggested by dividing the elements of gaps in public libraries into accessibility, core infrastructure, and services, focusing on vulnerable cities and counties in the Chungnam region.

• Journal of Internet Computing and Services
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• v.16 no.1
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• pp.83-90
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• 2015

This paper examines the rising value of social networked journalism and analyzes the case of a social news site based on the theory of networked journalism. Social networked journalism allows the public to be involved in every aspect of journalism production through crowd-sourcing and interactivity. The networking effect with the public is driving journalism to transform into a more open, more networked and more responsive venue. "wikitree" is a social networking news service on which anybody can write news and disseminate it via Facebook and Twitter. It is operated as an open sourced program which incorporates "Google Translate" to automatically convert all its content, enabling any global citizen with an Internet access to contribute news production and share either their own creative contents or generated contents from other sources. Since its inception, "wikitree global" site has been expanding its coverage rapidly with access points arising from 160 countries. Analyzing its international coverage by country and by news category as well as by the unique visit numbers via SNS, the results of the case study imply that networking with the global public can enhance news traffic to the social news site as well as to specific news items. The results also suggest that the utilization of Twitter and Facebook in social networked journalism can break the boundary between local and global public by extending news-gathering ability while growing audience's interest in the site, and engender a feasible business model for a local online journalism.

• Journal of the Society of Disaster Information
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• v.20 no.2
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• pp.339-350
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• 2024

Purpose: This study analyzes accessibility of 10 hydrogen charging stations in Seoul and identifies areas that were difficult to access. The purpose is to re-analyze accessibility by adding a new location in terms of equity and safety of location placement, and then draw implications by comparing the improvement effects. Method: By applying the location-allocation model and the service area model based on network analysis of the ArcGIS program, areas with weak access were identified. The location selection method applied the 'Minimize Facilities' method in consideration of the need for rapid arrival to insufficient hydrogen charging stations. The limit distance for arrival within a specific time was analyzed by applying the average vehicle traffic speed(23.1km/h, Seoul Open Data Square) in 2022 to three categories: 3,850m(10minutes), 5,775m(15minutes), 7,700m(20minutes). In order to minimize conflicts over the installation of hydrogen charging stations, special standards of the Ministry of Trade, Industry and Energy applied to derive candidate sites for additional installation of hydrogen charging stations among existing gas stations and LPG/CNG charging stations. Result: As a result of the analysis, it was confirmed that accessibility was significantly improved by installing 5 new hydrogen charging stations at relatively safe gas stations and LPG/CNG charging stations in areas where access to the existing 10 hydrogen charging stations is weak within 20 minutes. Nevertheless, it was found that there are still areas where access remains difficult. Conclusion: The location allocation model is used to identify areas where access to hydrogen charging stations is difficult and prioritize installation, decision-making to select locations for hydrogen charging stations based on scientific evidence can be supported.

• Journal of Korean Library and Information Science Society
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• v.51 no.4
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• pp.185-210
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• 2020

The library faced an unexpected crisis of COVID-19, and as a countermeasure strategy, non-face-to-face online service has been reinforced. Therefore, this study attempted to present a plan to overcome the challenges arising from rapidly changing external environment and current crisis. To this end, data search, electronic library, library service, cultural event and open space management status of 288 public libraries serviced as an integrated site were investigated. Based on this, the meaning of online services in the post-COVID-19 era and the implication of it were examined. As a result, first, the increase in the use rate of online data search services with the spread of non-face-to-face culture, second, the expansion of the services of the electronic library, third, the diversification of non-face-to-face, online services, fourth, expansion of online cultural event services, fifth, the diversification of open space services were proposed, sixth, Introduced an artificial intelligence system for unattended loan return based on access and the Seventh, expansion of experiential cultural support services and educational contents through VR, AR and MR. It is deemed necessary for the research on the future direction of the library's non-face-to-face services to be conducted by investigating the current status of online services in various types of libraries and the types and case studies of library services in the era of COVID-19.

• The Transactions of the Korea Information Processing Society
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• v.5 no.4
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• pp.975-983
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• 1998

In these days, information communication systems are based on both open distributed computing technologies and object-oriented techniques like inheritance, encapsulation and object reuse to support various system configuration and application. As information systems are interconnected through unsecure networks, the need for the secure information exchange is more critical than before. In this paper, we have designed and implemented a transparent CORBA-basce Security infrastructure with authentication, security context association, access control and security information management to support a secure applications in distributed object environment. SESAME Ver. 4 was adopted as an external security service to manage user privilege attributes and to distribute keys for data encryption, decryption and integrity. Using filter and transformer with an interface to Object Request Broker, it provides a transparent security service to applications. The filter objects are special classes that allow additional parameters to be inserted into messages before they are sent and removed just after they are received. The transformer objects are special classes that allow direct access to the byte stream of every messages for encryption and decryption before it is sent and just after it is received. This study is to implement the access control interceptor(ACI) and the secure invocation interceptor(SII) of secure ORB defined in CORBA using filter and transformer.

• Korean Security Journal
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• no.60
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• pp.113-135
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• 2019

Despite being one of the most important national facilities, the National Assembly building of the Republic of Korea has become increasingly vulnerable to potential terrorist attacks, and the instances of demonstrations occurring around and banned items taken into the building are continuing to rise. In addition, promoting the idea of "open assembly" has led to increased visitors and weakened access control. Furthermore, while there is a significant symbolic value attached to attacking the National Assembly building, the level of security management is relatively very low, making it a suitable target for terrorism. In order to address such vulnerability, an appropriate access control system should be in place from the areas surrounding the building. However, the National Assembly Security Service which oversees security around the building is scheduled to disband in June 2020 following the abolition of the conscripted police force in 2023. Therefore, there needs to be an alternative option to bolster the security system outside the facility. In this research, the perceptions of 114 government officials in charge of security at the National Assembly Secretariat toward the protection and security system of the areas surrounding the National Assembly building were examined. Results showed that the respondents believed it was highly likely that risky situations could occur outside the building, and the use of advanced technologies such as intelligent video surveillance, intrusion detection system, and drones was viewed favorably. Moreover, a mid- to long-term plan of establishing a unified three-layer protection system and designating a department in charge of the security outside the building were perceived positively. Lastly, the participants supported the idea of employing private police to replace the National Assembly Security Service for the short term and introducing parliamentary police for the mid- to long-term.