• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.9A
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• pp.905-915
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• 2007

This paper proposes a filter-based algorithm to adaptively adjust the contention window in IEEE 802.11 DCF. The proposed mechanism is focused on the general and realistic environments that have various conditions regarding to noise, media types and network load. For this flexible adaptation, Filter-based DCF(FDCF) takes a more realistic policy such as median filter concept in the image processing technologies. We can handle these various environments by adjusting the contention window size according to the result of filtering based on history-buffer. We can ignore temporarily and randomly occurred transmission failures due to noise errors and collisions in noisy environments. In addition, by changing the reference number and history-buffer size, FDCF can be extended as a general solution including previous proposed mechanism. We have confirmed that the proposed mechanism can achieve the better performance than those of previous researches in aspects of the throughput and the delay in the realistic environments.

• Journal of Society of Preventive Korean Medicine
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• v.24 no.2
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• pp.83-94
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• 2020

Backgrounds : To reduce the patients' economic burden of herbal decoctions use, in 2012, Korean government decided to implement the pilot project of herbal decoctions coverage in the National Health Insurance. Objectives : This study aimed to analyze the policy decision-making process for the pilot insurance project in 2012. Methods : Official documents, research papers, statistical reports, and news articles, etc. on the coverage of herbal decoctions were searched and collected. We used the Kingdon's Policy Stream Model to analyze how the policy of pilot project of herbal decoctions coverage was decided, and who were the main activists for the decision-making process. Results : Components to be included in the 'Problem stream' were the decline in the profits of Korean Medicine institutions, the contraction of the herbal decoctions use, and the fiscal surplus of National Health Insurance. In the 'Policy stream', there were several model studies for herbal decoctions coverage, and examples of herbal benefits in other social insurances. In the 'Political stream', there were the legislative initiatives by member of the National Assembly and the promotion of insurance coverage by the Association of Korean Medicine(AKOM), etc. Policy window for herbal decoctions coverage was opened by the combination of these three streams with the efforts of policy activists, such as the executives of AKOM, and policy researchers. Conclusions : The policy decision process for health insurance coverage of herbal decoctions was analyzed using Kingdon's model, and the analysis shows that the combination of political streams and entrepreneurs' competencies can be an important driving force in policy decision making.

• Health Policy and Management
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• v.30 no.3
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• pp.286-300
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• 2020

In 2019, the Seoul metropolitan government established its own 'Seoul-type paid sick leave project'. Although the central government had to introduce such a system, which is also called sickness benefits, it was not implemented. In order to understand the process by which the Seoul government has implemented such a policy, this study used Kingdon's multiple streams framework. As a result, in the problem stream, it was found that the economic burden of sickness has been considered only in terms of medical expenses in the past of Korea. Then Songpa's three women and Middle East respiratory syndrome incidents raised awareness of the necessity of the sickness benefit system in 2014 and 2015. In the political stream, several social affairs such as national health insurance huge surpluses and the 2017 presidential election opened policy window. At that time, Seoul Mayor actively promoted sickness benefits as a policy entrepreneur. In the policy stream, the sickness benefit system has gained new attention through political events. To summary, these three streams flowed separately and then they assembled around huge political affairs. As a result, it was confirmed that Kingdon's model is the most effective theory than any other models in analyzing the health care policy decision process in Korea.

• The Journal of the Korea Contents Association
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• v.13 no.5
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• pp.243-252
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• 2013

This study analyzes the policy-making process to promote the artists' welfare. In the problems stream, the artists have been found to suffer without any governmental support. In the policy stream, there have been various alternatives but they were not actualized. Meanwhile, a writer died of illness and famine in 2011. In the political stream, the public opinion to require the promotion of the artists' welfare, was strengthened. It made the policy-window open and resulted in the legislation of the Artists Welfare Law. Based upon these analyses, this article concludes that Kingdon's model is applicable to this case. Especially, this study shows that this policy was made with accidental events and the roles of informal participants such as netizen were more critical. However, it should be noted that the content of this Law was modified and trimmed because there was no policy entrepreneur to persuade the dissenters. It could made the policy-making process of this Law distinguished from others.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10c
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• pp.409-411
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• 2002

본 논문에서는 스트리밍 미디어 캐슁 서버의 효율적인 캐슁 구조를 위하여 참조 횟수, 참조량, 참조 시간 둥의 정량적인 인자들과 사용자 요구 주기를 적용하여 최근 참조 경향에 높은 가중치를 부여함으로써 변화하는 콘텐츠 선호 경향에 빠르게 적응하는 가중치 기반의 캐쉬 교체 정책을 제안한다. 성능 분석은 시뮬레이션 환경 구축을 통해 실험하였으며 LRU, LFU와 SEG 캐쉬 정책과 비교 분석하여 향상된 결과를 보였다.

• The KIPS Transactions:PartC
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• v.8C no.6
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• pp.793-805
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• 2001

In the recent priority system, high-priority packet will be served first and low-priority packet will be served when there isn\`t any high-priority packet in the system. By the way, even high-priority packet can be blocked by HOL (Head of Line) contention in the input queueing System. Therefore, the whole switching performance can be improved by serving low-priority packet even though high-priority packet is blocked. In this paper, we study the performance of preemptive priority in an input queueing switch for high speed switch system. The analysis of this switching system is taken into account of the influence of priority scheduling and the window scheme for head-of-line contention. We derive queue length distribution, delay and maximum throughput for the switching system based on these control schemes. Because of the service dependencies between inputs, an exact analysis of this switching system is intractable. Consequently, we provide an approximate analysis based on some independence assumption and the flow conservation rule. We use an equivalent queueing system to estimate the service capability seen by each input. In case of the preemptive priority policy without considering a window scheme, we extend the approximation technique used by Chen and Guerin [1] to obtain more accurate results. Moreover, we also propose newly a window scheme that is appropriate for the preemptive priority switching system in view of implementation and operation. It can improve the total system throughput and delay performance of low priority packets. We also analyze this window scheme using an equivalent queueing system and compare the performance results with that without the window scheme. Numerical results are compared with simulations.

• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.631-640
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• 2021

The purpose of this study focuses on and explain the policy-determining factors that emerged in the process of revising customized wages for the National Basic Livelihood Security Act on December 30, 2014. This is an analysis of the reasons why the rapid revision of the welfare system could have been made at a certain time in a situation that did not progress despite the specific demand for revision of the law surrounding the blind spot. To this end, using Kingdon's policy flow model, which emphasizes the contingency of policy decisions, the flow of problems, political flows, and policy alternatives were reviewed respectively. In the course of each of these flows, the suicide incident of mother and 2 daughters in Songpa served as a major medium that played a large role in the policy-making process and the window of policy could be opened. As a result, This incident triggered social and policy interest in the issue of the National Basic Livelihood Security Act. It was found that the law was revised quickly, causing a great wave of waves as a social issue.

• Proceedings of the Technology Innovation Conference
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• 2004.02a
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• pp.288-315
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• 2004

This paper has examined the leapfrogging thesis with the case of catch-up in digital TV by the Korean firms. Despite the disadvantages implied by the technological regime of digital TV and the risks facing early entrants in trajectory choice and initial market formation, the Korean firms had achieved a 'path-creating catch-up' in the sense they chose a different path from the Japanese forerunning firms. As they have been closely watching the technological trends and the standard setting process, there was less risk of choosing the right or wrong technological trajectory. Also, despite the lack of sufficient capability and core knowledge base, the Korean firms had some complementary asset, such as the experience of producing analogue TV, and were able to develop the prototype digital TV and the ASIC chips, given the accesses to the foreign knowledge via overseas R&D posts and acquisition of a foreign company. To secure the initial market size, the Korean targeted the US market from the beginning, and their sources for competitive advantages were the speedy setting up the production system for mass production of products at the initial stage. The initial failure of the Japanese firms and the success of the Korean firms do suggest that the period of paradigm shift, like this toward digital technology, can serve as a window of opportunity for late-comers while penalizing the forerunner.

• Korean Institute of Interior Design Journal
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• v.23 no.1
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• pp.69-77
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• 2014

This study aims to find the optimum method to reuse as townscape resource and to preserve the architectural heritage. And, it wants to contribute the policy of the architectural heritage and townscape. This research is targeted at an old office building of Leaf tobacco Producer' cooperation, designated as a cultural assets in Jecheon. It investigated the design characteristics of an old office building of Leaf tobacco Producer' cooperation and the streetscape of Uibyeong-daero 12-gil. It was conducted using the research methods of the field survey, and it was to analyze and to compare the various existing data and a current status. The result are as followings. Firstly, we should be consider the policy of architectural heritage that a sense of place can be preserved. Secondly, we should be consider the linear method of the conservation and reuse in urban street that the architectural heritage is located at least. Thirdly, if it will be to maintain the facade of the building adjacent to the street using the design characteristics of an old office building of Leaf tobacco Producer' cooperation, Uibyeong-daero 12-gil will be made a unique street that will be represented the history of leaf tobacco produce. Lastly, it has been analyzed that the design characteristics of an old office building of Leaf tobacco Producer' cooperation are the arch of entrance, the arched window, the rectangular window, the entabature, the horizontal joint, the finish of cement mortar, a pitched roof, etc. And, the design guideline and the maintenance plan of Uibyeong-daero 12-gil have made.

• Journal of Communications and Networks
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• v.12 no.5
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• pp.499-509
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• 2010

A plethora of transmission control protocol (TCP) congestion control algorithms have been devoted to achieving the ultimate goal of high link utilization and fair bandwidth sharing in high bandwidth-delay product (HBDP) networks. We present a new insight into the TCP congestion control problem; in particular an end-to-end delay-based approach for an HBDP network. Our main focus is to design an end-to-end mechanism that can achieve the goal without the assistance of any network feedback. Without a router's aid in notifying the network load factor of a bottleneck link, we utilize goodput and throughput values in order to estimate the load factor. The obtained load factor affects the congestion window adjustment. The new protocol, which is called TCP-goodput and throughput (GT), adopts the carefully designed inversely-proportional increase multiplicative decrease window control policy. Our protocol is stable and efficient regardless of the link capacity, the number of flows, and the round-trip delay. Simulation results show that TCP-GT achieves high utilization, good fairness, small standing queue size, and no packet loss in an HBDP environment.