• 한국정보과학회논문지:시스템및이론
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• 제34권11호
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• pp.589-598
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• 2007

다양한 종류의 데이타 스트림과 다양한 권한을 가지는 사용자들을 위한 그룹 통신을 위해서는 접근 제어(access control)가 필수적이다. 동일한 접근 권한을 가지는 그룹 멤버들은 하나의 클래스에 속하게 되며, 이러한 클래스들은 주어진 접근 관계를 표현한 하나의 계층을 구성한다. 그리고 각 클래스에는 하나의 비밀키가 할당된다. 기존의 기법들에서는 계층으로부터 하나의 논리적 키 트리를 생성하고 각 사용자는 항상 자신이 접근할 수 있는 모든 클래스의 키를 관리하는 방식, 즉 선행적(proactive)인 방식이었다. 하지만, 계층의 규모가 큰 경우에 사용자가 키를 저장하기 위한 공간이 늘어나고 키 갱신을 위한 메시지 또한 커진다는 단점을 가진다. 그리고 대부분의 경우 사용자는 극히 일부의 스트림만을 동시에 접근하게 되며, 이를 위해 모든 키를 지속적으로 갱신하는 것은 낭비가 된다. 본 논문에서는 이를 고려한 반응적(reactive)인 방식의 키 관리 기법을 제안한다. 각 사용자는 자신이 속한 서브그룹의 키만을 관리하며 다른 키가 필요한 경우에만 자신의 키와 공개 파라미터를 이용해서 해당 키를 추출하게 된다. 이로 인해 키 갱신을 위한 비용이 줄어들게 되고, 특히 접근 관계가 복잡하고 규모가 큰 그룹에 대해 좋은 성능을 가진다. 그리고 접근 관계가 변하는 경우, 이를 쉽게 반영할 수 있다는 장점을 가진다.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제9권1호
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• pp.100-108
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• 2003

원격 교육 시스템은 멀티캐스트를 사용함으로써 교육 내용을 전송하는 서버의 부하를 줄일 수 있을 뿐만 아니라 네트워크 대역폭을 효율적으로 사용할 수 있다. 본 논문은 원격 교육 시스템을 지원하기 위한 멀티캐스트 미들웨어를 설계, 구현한다. 본 논문에서 제시하는 멀티캐스트 미들웨어는 다음과 같은 특성을 갖는다: 1) 피동적 멤버를 위한 중앙 집중적인 멀티캐스트 그룹 관리를 통해 특정 수신자 그룹을 송신자가 지정하여 멀티캐스트 전송 2) 그룹 관리 서버와 멤버의 비정상적인 종료로 발생되는 예외 처리를 위한 멀티캐스트 그룹 정보 유지/복구 3) 대용량 멀티미디어 데이타의 멀티캐스트 전송을 위한 단편화 및 역단편화 지원과 버퍼 공유를 통한 추가적인 데이타 복사의 제거. 개발된 미들웨어는 30대의 PC가 Fast Ethernet으로 연결되어 있는 원격 교육 시스템에 실제로 적용하여 초당 18프레임의 320 $\times$ 120 픽셀의 해상도를 갖는 동영상과 128kbps의 음성 데이타, 기타 텍스트 메시지를 멀티캐스팅을 통해 요구 조건을 만족하는 송수신 성능을 보였다.

• The Journal of Asian Finance, Economics and Business
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• 제7권1호
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• pp.269-278
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• 2020

The study aims to verify the relationship between leaders' personality traits in leader - member exchange (LMX), and job performance. Hierarchical Regression Analysis was used to examines (a) how leaders' personality traits and LMX affect the influence of social capital on job performance and organizational citizenship behavior; (b) how perceived organization support (POS) can moderate the influences of LMX on social capital, in turn impacting job performance and OCB. Responses are employees in the service industry in Thailand, which consisted of 236 independent samples in 77 groups. Each group included at least one leader and 1-5 followers. The results show that there is a significant relationship between leader's personality traits, LMX and social capital. Leader with the higher level of conscientious, and agreeableness can always create good relations with their followers. The level of LMX are also related to social capital and both of these influence OCB and job performance. The moderating effect of perceived organizational support is also significant that POS can amplify the influence of LMX on social capital. Finally, the research findings show that perceived organizational support is one of the moderating factors in LMX exchanges. Followers perceived organizational support can amplify the influence of LMX on social capital.

• Nutrition Research and Practice
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• 제5권1호
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• pp.80-87
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• 2011

The objectives of the study were to investigate job burnout and leader-member exchange (LMX) levels as well as to evaluate buffering effects of LMX on burnout among dietitians and chefs at institutional foodservices. Hypotheses were proposed based on the Job Demands-Resources model and LMX theory. The study population consisted of dietitians and chefs who were in charge of managing unit operations in a nationwide contract management company. Positive/negative affectivity, workload, job burnout, and LMX scales that bad been validated in previous research were adopted A total of 552 questionnaires were distributed and 154 responses were returned. Results indicated that respondents' burnout levels were moderate and emotional exhaustion was greater than cynicism. In terms of LMX, the surveyed dietitians and chefs showed higher respect toward their supervisors than loyalty. When positive affectivity and negative affectivity were controlled, workload influenced emotional exhaustion and professional efficacy significantly. With affectivity and workload controlled, however, LMX did not influence any dimensions of burnout. The moderating effect of LMX on the relationship between workload and cynicism was significant. That is, the effect of workload on cynicism was weak if the dietitians and chefs perceived the relationship with their supervisor positively. Based on the findings and literature reviewed, how to mitigate job burnout among foodservice managers is discussed.

• 한국농공학회논문집
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• 제58권2호
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• pp.73-82
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• 2016

This study is about development of personal disaster shelters for minimization of the casualties caused by the landslide and steep slope collapse. The objectives of present research is the selection of disaster evacuation facilities utilizing FRP (Fiber Reinforced Plastic) material. For the proper assessment of FRP member, several layers by strength test and the three-dimensional numerical analysis of these FRR member was carried out. As a result, the personal disaster evacuation facility utilizing FRP materials, was found to be of a material that is able to protect the weak person at the time of the collapse of the landslides and steep slopes.

• 가정과삶의질연구
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• 제20권1호
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• pp.87-101
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• 2002

This paper serves to analyze the points of views un women in enlightenment discourse of the equality of sexes during the enlightenment period of Korea (1860 1910). The discourses of newspapers that are the text of this study have been analyzed with qualitative research technique. The major conclusions that are derived from the study are as follows. First, enlightenment discourse of the equality of sexes criticized women’s inferior status in family and in society. Second, the discourse, however, claimed the women's rights with the view of national interests, which meant that the ultimate goal of the discourse was not the enhancement of women's rights. Women during the enlightenment period were recognized as a member of a nation while they should also role as a member of If. The discourse also claimed that the equality of sexes could be realized through education and emphasized especially women's role as a mother who should raise a member of a nation. Third, enlightenment discourse would not understand the women's every day lives that resulted in demanding women more roles in the name of civilization.

• Safety and Health at Work
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• 제10권1호
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• pp.21-29
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• 2019

Background: Promoting healthy lifestyles at work should complement workplace safety programs. This study systematically investigates current states of occupational health and safety (OHS) policy as well as practice in the European Union (EU). Methods: OHS policies of EU member states were categorized as either prevention or health promotion provisions using a manifest content analysis. Policy rankings were then created for each prevention and promotion. Rankings compared eight indicators from the European Survey of Enterprises on New and Emerging Risks-2 data on prevention and promotion practices for each member state using Chi-square and probit regression analyses. Results: Overall, 73.1% of EU establishments take preventive measures against direct physical harm, and about 35.4% take measures to prevent psychosocial risks. Merely 29.5% have measures to promote health. Weak and inconsistent links between OHS policy and practice indicators were identified. Conclusion: National OHS policies evidently concentrate on prevention while compliance with health and safety practices is relatively low. Psychosocial risks are often addressed in national policy but not implemented by institutions. Current risk assessment methods are outdated and often lack psychosocial indicators. Health promotion at work is rare in policy and practice, and its interpretation remains preventive. Member states need to adopt policies that actively improve health and well-being at the workplace.

• 정보보호학회논문지
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• 제15권4호
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• pp.61-70
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• 2005

We propose and implement a flexible secure peer-to-peer(P2P) file sharing scheme which can be used for data sharing among closed user group (CUG) members. When a member wants to share data, notification messages are sent to the members with whom the member wants to share data. Each notification message includes one-time password encrypted with the receiver's public key. A member who received the notification message can download the data by using the one-time password. The proposed scheme provides selective sharing, download confirmation and efficient storage management. In terms of security, the proposed scheme supports authentication, entity privacy, replay attack protection and disguise prevention. We also implement the proposed system and find that the system is very useful among P2P service of closed user groups.

• 아태비즈니스연구
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• 제11권2호
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• pp.1-14
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• 2020

Purpose - The propose of this study is to examine the effect of human development index on mobile telephony diffusion. Design/methodology/approach - This study fits the modidensity of South Asian Association for Regional Cooperation (SAARC) member countries with an econometric Gompertz growth model. The diffusion factors, including the human development index (HDI), gross domestic product (nominal) per capita, fixed-line telephony subscription, and population data of each member country from 2005 to 2018 are considered for the empirical experiment. Furthermore, the mobidensity of randomly sampled countries with very high human development scores (the Republic of Korea, Switzerland and Norway) and high development scores (Brazil and Costa Rica) have been examined with the same process as SAARC members. Findings - We have found a positive but insignificant relationship between the HDI value and mobile telephony diffusion in Afghanistan, Bangladesh, Bhutan, India, and Pakistan; a positive and statistically significant relationship at a 99% confidence level in SriLanka; and a negative and insignificant relationship in the Maldives and Nepal. HDI has both positive and negative effects on mobile telephony diffusion, with the nature of effect depending on the profiles of each country. HDI is a diffusion determinant of mobile telephony only for the high human development country groups. Research implications or Originality - This study provides a reference for policymakers, telecommunication stakeholders, and future researchers to design the telecommunication policies and strategies.

• 가정과삶의질연구
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• 제11권2호
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• pp.55-68
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• 1993

The purpose of this study were to investigate the allocation of time for housework and leisure and the causal relations between management satisfaction and all variables affecting it. for this purposes the data were collected through the questionnaire whose respondnet were 448 housewives. The major results of this study were as follows; 1`) The housework time was affected by the number of family member the age of wife and income. And leisure time was affected by the work status and age of wife educational level and income. The satisfaction level of management were affected by the wife's work status and educational level and income. 2) The relation between housework time and time management strategies was negative And the relations between satisfaction level of management and time planning time management strategies were positive. 3) Among all variables affcting the satisfaction level of management the educational level income time planning time management strategies and leisure time had direct effect And the work status had indirect effect.