• Title/Summary/Keyword: 강철희

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Interworking Mechanism for QOS support Between MPLS and DS (ATM 기반의 MPLS 네트워크에서 QOS 를 보장하는 MPLS 와 DS 연동 메커니즘)

  • Song, Ye-Jin;Seok, Seung-Joon;Kang, Chul-Hee
    • Proceedings of the Korea Information Processing Society Conference
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    • 2000.04a
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    • pp.686-691
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    • 2000
  • 최근 들어 인터넷의 사용이 급격히 증가함에 따라 인터넷의 백본망에는 패킷 전달의 고속성, 확장성 뿐만 아니라 QOS 보장을 요구하게 되었다. 효과적인 인터넷 백본망을 구현하기 위해 본 논문에서는 Multi-Protocol Label Switching(MPLS)를 고려하고 MPLS 에서 인터넷 Quality Of Service(QOS) 서비스 모델 중 백본망에 적합한 Differentiated Service(DS) 모델을 그대로 제공하기 위해 MPLS 와 DS 의 연동에 대한 문제를 다룬다. 우선 MPLS 에서 QOS 제공을 위한 기능요소를 정성적으로 분석한다. 그리고 두 DS 망 가운데 ATM 기반의 MPLS 망을 두고 있는 경우를 가정하여, 종단대 종단간 DS 제공을 위하여 DS 망과 MPLS 망에서의 시그널링 과정을 제안한다. 즉, DS 의 BB 로부터 SLA 를 위한 신호를 MPLS 의 입구 라우터에서 해석하여 DS Type-Length-Value(TLV)를 만들고 이를 이용하여 Constraint-based Label Distribution Protocol(CR-LDP) 시그널링을 통해 마다 Label-Only-Inferred-PSC LSP(L-LSP)를 설립하여 MPLS 에서 DS QOS 를 그대로 제공한다. 또한 입구 DS BB 로부터의 정보를 MPLS 망을 통해 BB 에게 보낸다.

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Process for the Architectural Application of Biomimicry (생체모방의 건축적 적용을 위한 프로세스)

  • Kim, Jong-Moo;Kang, Chul-Hee;Yoon, Heakyung
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.34 no.12
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    • pp.77-84
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    • 2018
  • Biomimicry architecture has been highlighted in recent years for the innovative ideas from the nature have provided main developments in many areas. The related studies in Korean architecture is entering the first step and are needed close attentions for its vitalizations. This study starts with the acknowledgement of necessity to establish the architectural application process. First of all, it is named as a 'Passive Cycle' if a problem-solving or a project has been through the analysis of process complexity and biomimicry application process in other areas. Then, the basic frame is structured as a 'Process-Cooperation,' which integrates process complexation with process circulation. The cooperative relationship starts from the beginning of the design with not only professionalists related with architecture but also ones in various areas when it is issued a difficult problem or high environmental performance not found in common architectural design processes. To make the architectural application good progress, the characteristics of bio-mimetic architectural applications are categorized as three areas; the expected effect, the application level, and application method. As a result, the organic complexity should be prioritized to have bio-mimetic application effectively while accessing the principles. Therefore, the process for the architectural application of biomimicry is suggested as 'Organic Cycle-Cooperation.'

Traffic Anomaly Detection for Campus Networks using Fisher Linear Discriminant (Fisher 선형 분류법을 이용한 비정상 트래픽 탐지)

  • Park, Hyun-Hee;Kim, Mee-Joung;Kang, Chul-Hee
    • Journal of IKEEE
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    • v.13 no.2
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    • pp.140-149
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    • 2009
  • Traffic anomaly detection is one of important technology that should be considered in network security and administration. In this paper, we propose an abnormal traffic detection mechanism that includes traffic monitoring and traffic analysis. We develop analytical passive monitoring system called WISE-Mon which can inspect traffic behavior. We establish a criterion by analyzing the characteristics of a traffic training set. To detect abnormal traffic, we derive a hyperplane by using Fisher linear discriminant and chi-square distribution as well as the analyzed characteristics of traffic. Our mechanism can support reliable results for traffic anomaly detection and is compatible to real-time detection. In addition, since the trend of traffic can be changed as time passes, the hyperplane has to be updated periodically to reflect the changes. Accordingly, we consider the self-learning algorithm which reflects the trend of the traffic and so enables to increase the pliability of detection probability. Numerical results are presented to validate the accuracy of proposed mechanism. It shows that the proposed mechanism is reliable and relevant for traffic anomaly detection.

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A Study of the Relationship between Religion and Giving Behavior -Analyzing Moderating Effect of Religiosity- (종교와 기부행동의 관계에 대한 연구 -종교성의 조절효과-)

  • Kang, Chulhee;Hur, Younghye;Choi, Younghoon
    • Korean Journal of Social Welfare
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    • v.65 no.4
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    • pp.341-365
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    • 2013
  • This study attempts to examine the moderating effect of religiosity in the relationship between religion and secular giving behavior (absolute amount and philanthropic effort). For the analysis, this study utilizes 'Giving Korea 2012' by the Beautiful Foundation and employs Tobit regression model. Focusing on giving amount, major findings are that (1) Protestants and Catholics give greater amounts for secular cause than those with no religious affiliation; and (2) interaction between Protestants and religiosity and interaction between Catholics and religiosity have significant relationships with citizens' secular giving amount in a positive direction. Focusing on philanthropic effort (giving amount divided by family income), major findings are that (1) there is no significant relationship between religion types and citizens' philanthropic effort and (2) interaction between Protestants and religiosity and interaction between Catholics and religiosity have significant relationships with citizens'philanthropic effort in a positive direction. This study provides new knowledge foundation on citizens' secular giving behavior and contributes to developing effective fundraising strategies of nonprofit organizations on religion-related donor markets.

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A Deterministic Access Protocol in WiMedia Wireless Personal Area Networks (WiMedia 초고속 근거리 무선 통신에서의 결정적 접근 프로토콜)

  • Park, Hyun-Hee;Pack, Sang-Heon;Kim, Yong-Sun;Kang, Chul-Hee
    • Journal of IKEEE
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    • v.13 no.3
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    • pp.7-17
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    • 2009
  • WiMedia UWB technology is a fully distributed data communication technology developed for the application demanding a high data transmission rate in the wireless PAN area. In general, devices can send data either by reserving time slots or by using prioritized CSMA/CA. If the PCA protocol of prioritized CSMA/CA is used, they are suffered congestion as the number of devices increases. In this paper, we propose a Deterministic Access Protocol(DAP) in WiMedia WPANs. A DAP is a method to transmit data in the non-reserved DRP period without competition as each device informs the beacon order information in the beacon period and the queue information. In addition, the problem that the devices with a lower beacon slot number have more transmission opportunities is addressed by introducing the reference point. Simulation results are given to demonstrate that a DAP can improve the throughput and reduce the packet loss rate.

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Unemployment Duration and Re-employment Pattern : An Analysis using Weibull Model and Logistic Regression Model (실업자의 재취업과 재취업 형태에 관한 연구 : Weibull Survival Model과 Logistic Regression을 이용한 분석)

  • Kang, Chul-Hee;Kim, Kyo-Seong
    • Korean Journal of Social Welfare
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    • v.39
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    • pp.5-40
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    • 1999
  • Little is known about unemployment duration and re-employment pattern. This paper empirically examines unemployment duration and re-employment pattern using data by the 1998 national survey about the unemployed and their needs. A parametric survival model(Weibull model) is adopted to identify variables predicting unemployment duration. It is found that the data including people without unemployment insurance as well as people with unemployment insurance fit the Weibull model including the hazard distribution that the hazard of reemployment is increasing at an decreasing rate. Variables that affect unemployment duration are age, householdership, family income, size of prior employment organization, and cause of unemployment. In re-employment pattern, statistically significant variables are age, type of prior employment industry, prior employment pattern, and membership in unemployment insurance. This paper provides a basic knowledge about realities of unemployed individuals in the economic crisis period of Korea, identifies research areas for further research, and develops policy implications for the unemployed.

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SDN-Based Middlebox Management Framework in Integrated Wired and Wireless Networks (유무선 통합망에서의 SDN 기반 미들박스 관리 프레임워크)

  • Lee, Giwon;Jang, Insun;Kim, Wontae;Joo, Sukjin;Kim, Myungsoo;Pack, Sangheon;Kang, Chul-Hee
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39B no.6
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    • pp.379-386
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    • 2014
  • Recently, middleboxes play a key role in many network settings such as firewalls, VPN gateways, proxies, intrusion detection and prevention systems, and WAN optimizers. However, achieving the performance and security benefits that middleboxes offer is highly complex, and therefore it is essential to manage middleboxes efficiently and dynamically. In this respect, Software-Defined Networking (SDN) offers a promising solution for middlebox policy enforcement by using logically centralized management, decoupling the data and control planes, and providing the ability to programmatically configure forwarding rules. Also, cloud computing and distributed Network Function Virtualization (NFV) can enable to manage middleboxes more easily. We introduce SDN-based middlebox management framework in integrated wired and wireless networks and discuss the further issues.

A Study of Board Function Effectiveness and Organizational Performance in Korean Community Chest Organizations (복지 비영리 조직의 이사회 기능 효과성과 조직성과에 관한 연구 : 한국사회복지 공동모금회를 중심으로)

  • Kang, Chul-Hee;Kim, Hee-Sung
    • Korean Journal of Social Welfare
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    • v.44
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    • pp.7-35
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    • 2001
  • Little empirical study has been conducted concerning board function effectiveness and organizational performance in nonprofit nongovernmental human service organizations in Korea. Using the evaluations of 107 board members and 17 executive directors in Korean Community Chest and 16 regional community chests, this study attempted to examine the level of board function effectiveness and its relationship with organizational performance in these community chests. This study used board function scale developed by Holland and Jackson (1998) to measure board function effectiveness in the following 6 dimensions: contextual dimension: educational dimension: interpersonal dimension: analytical dimension: political dimension: and strategic dimension. This study showed that using 4 points scale, mean of overall board function effectiveness evaluated by board members is 2.62 and mean of overall board function effectiveness evaluated by executive directors is 2.73. That is, it showed that means of overall board function effectiveness are located in the middle point between negative evaluation and positive evaluation. On the other hand, using parametric correlation analysis method, it was found that in these community chests the association between board function effectiveness and organizational performance measured by fund-raising growth rate in $1999{\sim}2000\;and\;1998{\sim}2000$ is very weak and statistically nonsignificant. This study also revealed that using nonparametric correlation analysis method, the association between consensus level in evaluation by board members and executive directors about board function effectiveness, and organizational performance is still very weak and statistically nonsignificant. Finally, this study discussed the direction of future research in board function effectiveness and its relationship with organizational performance and the areas of board management that requires substantial efforts for promoting effectiveness of nonprofit human service organizations in Korea.

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A Study of Active Labor Market Policy and Unemployment : An Analysis Using Fuller-Battese Model (적극적 노동시장정책의 실업 감소 효과에 관한 연구)

  • Kang, Chul-Hee;Kim, Kyo-Seong;Kim, Young-Bum
    • Korean Journal of Social Welfare
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    • v.45
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    • pp.7-39
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    • 2001
  • This paper examines the effect of active labor market policy on the unemployment rates in 8 welfare states. This paper focuses on the following questions: what are the major predictors of the changes in unemployment rates?; and what is the effect of active labor market policy in reducing unemployment rates? Using the data from Comparative Welfare States Data Set by Stephens (1997), Key Indicators of the Labour Market by ILO (1999) and Social Expenditure Database by OECD (1999), this paper attempts to answer the above research questions. Fuller-Battese model, a data analysis method in pooled cross-sectional time-series analysis, is adopted to identify variables predicting changes in unemployment rates. This paper analyzes the predictors by using 3 analysis models about 2 types of unemployment (overall unemployment and long term unemployment). Results are as follows: (1) economic variable such as changes in GDP has a positive effect in reducing unemployment rates; (2) active labor market policy has a positive effect in reducing unemployment rates as well; (3) job brokering service among 3 major active labor market programs has a positive effect in reducing unemployment rates; and (4) there is an interaction effect between unemployment benefit level and active labor market policy in reducing unemployment rates. Through the empirical analysis, this paper provides valuable knowledge about effects of active labor market policy on unemployment in 8 welfare states and discusses implications for the active labor market policy in Korea.

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A Study on the Performance of the Human Service Organizations : An Analysis from the Perspective of Quality of Output (사회복지서비스 기관의 조직성과에 관한 연구 : 서울시 지역사회복지관의 질 산출(quality output)을 중심으로)

  • Kang, Chul-Hee;Chung, Moo-Sung
    • Korean Journal of Social Welfare
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    • v.49
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    • pp.343-378
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    • 2002
  • This study examines the organizational performance of human service organizations from the quality output perspective. Using the 2001 evaluation data about 89 community welfare centers in Seoul, this study attempts to identify the levels of the performance of human service organizations in Korea. This study also attempts to identify the factors that predict performance of human service organizations measured in terms of client satisfaction and experts' evaluation about the functioning of each center. Results are as follows: (1) when pooling 866 clients' satisfaction level into satisfaction score about each center, the average of client satisfaction about the centers is 3.42 at 4 points scale. (2) 41.6% of the community welfare centers is evaluated as "highly qualified" in its overall operation and functioning by the professional evaluation team, (3) the employee reward system(+), practice based on the program guideline manual(+), the portion of the government support grant in its budget(-), the overall employee salary level(-), the level of acquirement of program grants from external sources (-) are the predictors in explaining clients' satisfaction level, and (4) the level of professional expertise of the executive director(+), the level of professional supervision of middle managers(+), the employee reward system(+), the program need assessment(+), the level of client information system(+), the portion of government support grant(-), the overall employee salary level(-) are the predictors for "being highly qualified" in its overall operation and function of each center. Through the empirical analysis, this study provides valuable knowledge about organizational performance of community welfare centers from the quality output perspective. Finally, this study discusses implications for more effective and efficient organizational performance of community welfare centers in Korea.

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