• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.11B
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• pp.1573-1582
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• 2001

In this paper we analyze the main resources of error in GEO-satellite STFS(Standard Time & frequency Signal) dissemination system. For the case of small countries like Korea, we compare GEO-satellite STFS dissemination technique with the terrestrial network or with the GPS using LEO-satellites, and analyze its advantages over the forementioned systems. We also introduce the GEO-satellite STFS dissemination systems which are being developed or in service. Particularly, we put much efforts to develop the synchronization error calibration technique required to provide a highly accurate STFS service via KoreaSAT. We then propose the differential mode technique as the most effective and efficient calibration technique for mitigating errors in GEO-satellite STFS dissemination systems, and analyze its performance via computer simulation. We also analyze the relation between time accuracy and frequency accuracy. Our experimental results show that the time accuracy is better than 100 ns and the frequency accuracy is better than 10-13 over 7 days all around Korea peninsula. Finally, we propose methods to improve the performance of STFS dissemination system, and demonstrate that the proposed methods result in more accurate synchronization of GEO-satellite STFS.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.720-725
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• 2009

SDI(Selective Dissemination of Information) is on demand service to inform to the user applies a service after inputting a search strategy, when new information is obtained. This Paper propose the ways to develope the dynamic RSS channel generator for supporting SDI service. The RSS which is a kind of syndication technology enables a part or the whole of the content which it provides from web site to be able to be used in different service. It is protocol to summarize and share various contents on web site. Also, the users register the channel RSS to the RSS aggregator system and recommend it. It can drive to share of knowledge between researchers.

• Journal of East-Asian Urban History
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• v.2 no.2
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• pp.309-339
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• 2020

Obviously the speed of dissemination of new, modern ideas in Jiangnan was closely related to the development of transportation. Looking back at the history, the backwardness of transportation in the early modern Jiangnan restrict the dissemination of new ideas in this region and then the situation changed a lot since the 1890s, when the spatial distance between Shanghai and Jiangnan was remarkably shortened, the dissemination of new ideas was accelerated, and the new ideas in return significantly influenced the Jiangnan society. It was the constantly improved transportation that facilitated the diversification of channels disseminating information and made the dissemination itself faster. As a consequence, the new ideas, knowledge, and things were rapidly disseminated and popularized in Jiangnan, thereby giving impetus to the social changes in this region.

• Korean Journal of Social Welfare
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• v.52
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• pp.89-115
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• 2003

While many social work studies has focused on the development of practice intervention and demonstration of the efficacy, little attention has been given to the way how the results can be disseminated and utilized in practice area. But attempts to bridge the research-practice gap empathize importance of dissemination and utilization including knowledge utilization, innovation diffusion, information dissemination, program replication, and technology transfer etc. In this recognition, this study that focused on the process after development of program tried to search and analyze the real disseminating process and utilization state with applying Growing-up Skills Program(GUSP) developed and disseminated by this researcher. For the purpose, theories and models for program diffusion were reviewed, and dissemination & utilization of GUSP was analyzed on the 'Herie & Martin's model' with retrospective perspectives. Through this tracer study, these were confirmed or founded as problems of GUSP in disseminating process : lack of specific strategy for the dissemination ; unplanned coping due to little preparation ; and unclear and insufficient understanding of the target system in the beginning stage of dissemination. And followings are suggested for the improvement of social work program dissemination & utilization in the field: to conduct diffusion process on the basis of a proper model; to consider integrative relationship between D&D and dissemination & utilization ; to endeavor for collecting feed back from the field ; and to reinforce social work education and study related to innovation diffusion. These results showed importance of dissemination & utilization in social work and utility of GUSP despite of several limitations. More concerns of dissemination & utilization are needed for the integration of research and practice in Korean social work.

• Journal of Communications and Networks
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• v.17 no.2
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• pp.133-144
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• 2015

In this paper, we introduce a system and a set of algorithms for disseminating popular content to a large group of wireless clients spread over a wide area. This area is partitioned into multiple cells and there is a base station in each cell which is able to broadcast to the clients within its radio coverage. Dissemination of information in the proposed system is hybrid in nature: Each base station broadcasts a fraction of information in the form of random linear combinations of data blocks. Then the clients cooperate by exchanging packets to obtain their desired messages while they are moving arbitrarily over the area. In this paper, fundamental trade-offs between the average information delivery completion time at the clients and different parameters of the system such as bandwidth usage by the base stations, average energy consumption by the clients and the popularity of the spread information are studied. Moreover different heuristic algorithms are proposed to control and maintain a balance over these trade-offs. Also, the more complicated case of multiple sessions where each client is interested in an arbitrary subset of sessions is considered and two variants of the basic dissemination algorithm are proposed. The performance of all the proposed algorithms is evaluated via extensive numerical experiments.

• Journal of Internet Computing and Services
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• v.9 no.5
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• pp.131-140
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• 2008

In this paper, we present a data dissemination protocol that guarantees energy-efficient data transmission and maximizes network lifetime. SPMS that outperforms the well-known protocol SPIN uses the shortest path to minimize the energy consumption. However, since it repeatedly uses the same path, maximizing the network lifetime is impossible. In this paper, we propose a protocol for data dissemination called the protocol Considering Between Energy and Distance (ConBED). It solves the network lifetime problem using the residual energy and the distance between nodes to determine a path for data dissemination. The simulation results show that ConBED guarantees energy-efficient transmission and increases the network lifetime by approximately 69% than that of SPMS.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1990.04a
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• pp.312-325
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• 1990

This paper addresses the process of information dissemination in a network whereby a message, originated at a node, is transmitted to all other nodes of the network. We restrict our attention to a speccial type of dissemination process,called 'local broadcasting', where a vertex can either transmit or receive a message and an informed vertex can transmit it to only one of its neighbors at a time. Based on the recently published results for a tree by Koh and Tcha, this paper proposes an efficient heuristic which determines the call sequence at each vertex node under both minimax and minisum criteria. Computational experiments with this heuristic are conducted on a variety of networks of medium size.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.460-462
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• 1999

휴대형 컴퓨터와 무선통신기술의 급속한 발달은 사용자에게 언제, 어디서나 필요한 컴퓨팅을 수행할 수 있는 이동 컴퓨팅이라는 새로운 패러다임을 발생케 하였다. 이동 컴퓨팅 환경은 대역폭(bandwidth)과 저 수준의 전송품질을 가지고 있기 때문에 서버가 어떠한 방법으로 데이터 dissemination을 이용하는 새로운 시스템 구조들이 제안되었다. 본 논문에서는 데이터 dissemination의 한 기법인 브로트캐스트 기법에서의 데이터 일관성 유지 문제와 이동 클라이언트의 효율적 전력 사용 문제를 동시에 고려한 브로트캐스트 기법을 제안하였다.

• Journal of the Korean Society for Library and Information Science
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• v.34 no.4
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• pp.143-160
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• 2000

The primary purpose of the present study is two-fold: i) to analyze the level of understanding and perception of stakeholders on the dissemination policy of digital geographic information and ii) to explore the policy direction to enhance the user accessibility based upon stakeholder analysis. The study is composed of descriptive analysis with extensive literature review and empirical analysis. The empirical analysis employs qualitative method as well as quantitative one, articulating perception of stakeholders in a comparative manner and suggesting policy directions. Based on the interview and the survey results, the study proposes the overall directions of dissemination policy to facilitate the efficient use of digital geographic information.

• Journal of KIISE:Information Networking
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• v.33 no.2
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• pp.165-174
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• 2006

Data dissemination using either flooding or legacy ad-hoc routing protocol is not realistic approach in the wireless sensor networks, which are composed of sensor nodes with very weak computing power, small memory and limited battery. In this paper, we propose the ELF(Energy-efficient Localized Flooding) protocol. The ELF is energy-efficient data dissemination protocol for wireless sensor networks. In the ELF protocol, there are two data delivery phases between fixed source and mobile sink node. The first phase, before the tracking zone, sensing data are forwarded by unicasting. After that, within the tracking zone, sensing data are delivered by localized flooding. Namely, the ELF Properly combines advantages from both unicasting and flooding. According to evaluation results by simulation, the proposed ELF protocol maintains very high data delivery ratio with using a little energy. Also, the property of average delay is better than others. From our research results, the ELF is very effective data dissemination protocol for wireless sensor networks.