• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.7
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• pp.1737-1753
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• 2013

Current group key agreement protocols, which are often tree-based, have unnecessary delays that are caused when members with low-performance computer systems join a group key computation process. These delays are caused by the computations necessary to balance a key tree after membership changes. An alternate approach to group key generation that reduces delays is the dynamic prioritizing mechanism of queue-based group key generation. We propose an efficient group key agreement protocol and present the results of performance evaluation tests of this protocol. The queue-based approach that we propose is scalable and requires less computational overhead than conventional tree-based protocols.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2006.06a
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• pp.322-325
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• 2006

그룹 키 동의 프로토콜에 관한 연구는 그동안 많은 연구자들에 의해 다양한 관점에서 진행되어왔으며, 최근 Nam 등이 유 무선 통합 네트워크 환경에서 효율적이면서도 안전한 그룹 키 동의 프로토콜을 제안하였다. 유 무선 통합 네트워크 환경에 적합한 그룹 키 동의 프로토콜을 설계하기 위해서는 고성능 연산 능력을 가진 유선 단말기의 특성과 상대적으로 계산능력이 떨어지는 무선 단말기의 특성이 함께 고려되어야 한다. 특히, 시스템자원의 제한성을 갖는 무선 단말기에서의 계산량을 최소화하는 문제는 그룹 키 동의 프로토콜 설계에 있어서 무엇보다 중요하다. 따라서, 본 논문에서는 무선 단말기의 계산량을 최소화하면서 유 무선 통합 네트워크 환경에 적합한 효율적인 그룹 키 동의 프로토콜을 제안하고자 한다.

• The Transactions of the Korea Information Processing Society
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• v.6 no.11S
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• pp.3379-3389
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• 1999

Important network application services have been rapidly increased along with the growth of the Internet. So, it is desirable for such applications to serve transparently, continuously and safely even if the network is temporally disconnected or certain hosts running those services are crashed down. To satisfy such requirementes, many group communication systems have been developed; but, those systems restrict its range within a single LAN or directly interconnected LAN environments since the communication through the Internet is too slow and too unreliable to support group communication. As of now, it is expected the Internet is going to e sufficiently fast and reliable in the near communication system, named FACE(Java Advanced Communication Environment), supporting Extended Virtual which is a basic communication layer, RPGS(Reliable Process Group Service) which manages application process groups, and JACE API for developing Java application services and clients programs. In addition, an experimental replicated object space is developed as an application of the JACE system.

• Journal of Korean Academy of Nursing
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• v.4 no.2
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• pp.78-92
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• 1974

It is the purpose of this study to make clear the way in which people can lead a more desirable human life, that is, to ascertain the method of achieving therapeutic change through transaction between nurses and psychiatric patients. The various problems proposed by th9 above-stated aims of study can be shown, such as: What kind of influences does the method of a nurse′s communication have upon the response of psychiatric patients? 1) What are the general methods of communication used by the nurses? 2) Are there any differences between the control group and experimental group in the patients′ "Child" response? 3) Are there any differences between the control group and experimental group in the Patients "Adult" response? 4) What is the most desirable method of communication for therapeutic change in the patients? In an effort to solve the above questions this study attempted and managed to draw a random sampling of 200 patients being accommodated in the National Mental Hospital by dividing them into two groups, experimental groups and control groups, and recording the transactions between nurses and patients. In the course of carrying,: out this study, the experimental group was interviewed by the nurses specially trained In the P.A.C theory. and the control group interviewed at random by the nurses with no special training in communication. Further, the communication between nurses and patients in a free, relaxed atmosphere was allowed only for 15 minutes, whereupon the nurses were requested to make process-recording according to her memory of nurse patient transaction. The process-recording which recorded a series ol transactions between the nurses and the patients was analyzed according to Berne and Harris′transactional Analysis Standard. Through this standard, the writer of this study examined the significance of difference to compare the transactions brought forth between the experimental group and the control group. The following is a summary of the study which the writer of this thesis undertook. Hypothesis to The method of communication which the nurses usually apply to the patients will be higher in "Parent" than in "Adult". The communication which the nurses carried out in the control group turned out to be not significant between "Adult" and "Parent" Accordingly hypothesis 1. carne to be rejected. Hypothesis 2. The patients "Adult" response will be higher in the experimental group than in the control group. According to the result of a CR examination, as the communication showed a significant difference on P〈.01 level′ hypothesis 2 became affirmative. Hypothesis 3. The patients′"Child" response will be higher in the control group than in the experimental group. Hypothesis 3 proved affirmative since it showed an significant degree on P〈.01 level according to the result of a CR examination. Hypothesis 4 "Adult" response of the patient will be higher in frequency by nurses′"Adult" stimulus than nurse′s "Parent" stimulus Chi-square examination revealed significant difference on P〈.05 level. Hypo. 4 is affirmed. The following conclusions are drawn out based on the result of this study. 1) The generally used method of communication stimulus used by nurses for patients proved to be "Adult" and "Parent" in similar proportion. 2) The group in which the nurses could increase the patients "Adult" response proved to be higher in the experimental group than in the control group. Therefore, the communication (or stimulus) which has been applied in the experimental group can be said to be possible method of achieving therapeutic change. 3) Since the patients′"Child" response were higher in the control group than in the experimental group the communication method used In the control group was suggested as the less agreeable method of achieving therapeutic change than that used in the experimental Group. 4) "Adult" response of patient was elicited in significantly greater percentage when the "Adult" stimulus was used by the nurse. Therefore the most desirable method of-communication to give therapeutic change definitely was shown to be the "Adult" stimulus. Recommendations for further studies are as follows: 1) Studies on nurses′role perception in nurse-patient relationships. 2) Studies on patients′response to the method of communication used by nurses according to variables such as sex, social status, educational background, state of health. 3) Application of T.A, method to various groups of patients. 4) Study of various methods to improve student skill in use of process recording.

• Asia pacific journal of information systems
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• v.16 no.4
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• pp.179-202
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• 2006

The objective of this study is to identify the impacts of communication reinforcement on performance of learning in Web-PBL. Communication reinforcement is defined as the combination of information sharing and co-construction. As factors facilitating communication reinforcement, we propose learner's characteristics, task characteristics, and group characteristics. Learner's characteristics are collaboration-orientation, openness, holistic approach, and online community-orientation which reflects e-learning environment. Collaboration-oriented tasks as group projects were developed and given to groups with 5-6 members. The group characteristics are categorized into 'horizontal' and 'vertical', according to the patterns of communication between a group leader and members. To verify empirically the proposed research model, an experimental design was performed to learners who took on-line and off-line courses with group projects. We found important results as follows; First, field dependence has positive impacts on information sharing, and online community-orientation has positive impacts on co-construction. These results correspond with prior studies on relationship between field dependence and collaborative learning. Second, collaboration-oriented task directly impacts on information sharing, and indirectly affects co-construction, This result implicates that information sharing is pre-requisite of co-construction. Third, 'horizontal' was identified as a factor giving positive effects on information sharing and co-construction. This result implies that horizontal communication is very important to facilitate communication reinforcement.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.10
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• pp.533-543
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• 2003

With the increase of interests in cluster, there have been a number of research efforts to address the high availability issues on cluster. However, there are no kernel-level group communication systems to support the development of kernel-level application programs and it is not easy to use traditional user-level group communication systems for the kernel-level applications. This paper presents the design and implementation issues of KCGCS(Kernel-level Cluster Group Communication System), which is a kernel-level group communication module for linux cluster. Unlike traditional user-level group communication systems, the KCGCS uses light-weight heartbeat messages and a ring-based heartbeat mechanism, which allows users to implement scalable failure detection mechanisms. Moreover, the KCGCS improves the reliability by using distributed coordinators to maintain membership information.

• Bulletin of the Korean Space Science Society
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• 2004.10b
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• pp.95-95
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• 2004

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.3
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• pp.571-578
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• 2006

To renew the group key securing on the mobile communication needs that it can be not oかy re-shared by all members of the group with the exception of members excluded but also prevented from making a fraudulent use of a terminal's registered key because of a leakage of information from the loss of terminal. In this paper, we propose an efficient renewal mechanism of group key in order for all members of the group to be able to get digital information and to perform the renewal of group key in a small-scale conference employing the Fiat-Shamir method. It can guarantee the security of terminals, since a terminal generates security information needed for key renewal, and then renews the group key for mutual communication.

• Journal of Korean Academy of Nursing
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• v.40 no.5
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• pp.620-630
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• 2010

Purpose: This study was conducted to compare the level of depression, self-esteem and mother-adolescent (M-A) communication perceived by both mothers and adolescents between the early adolescent (E-A) group and the late adolescent (L-A) group; and to examine the actor effect and the partner effect of self-esteem and M-A communication on depression in mothers and adolescents. Methods: Participants were 107 Kirogi families who resided in the Midwest region of the U. S. Data were collected from September, 2008 to March, 2009 using the scales of Center for Epidemiologic Studies Depression (CES-D), Self-esteem and Parent-Adolescent Communication Inventory. Results: Mothers in E-A group reported higher scores on depression than mothers in L-A group. Adolescents in L-A group reported higher scores on depression and lower scores on self-esteem than adolescents in E-A group. In the E-A group, mothers' selfesteem had big actor effect on mothers' depression and partner effect on adolescents' depression. In the L-A group, selfesteem of mothers and adolescents had actor effect on their depression respectively without partner effect. M-A communication of mothers influences mothers' depression negatively and adolescents' depression positively. In both group, M-A communication influences their depression with mediating effect of self-esteem. Conclusion: To promote Kirogi families' mental health, programs for mothers and adolescents should be developed differently according to adolescents' development stage.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2006.06a
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• pp.525-528
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• 2006

최근 전자투표 시스템에 대한 투표자의 신뢰성을 높이기 위해 영수증을 발급하는 기술에 대한 연구가 활발히 진행되고 있다. 전자투표 영수증은 투표자가 자신이 투표한 결과가 최종집계에 올바르게 반영되었음을 확인할 수 있어야 하며, 매표 방지 기능도 함께 가지고 있어야 한다. 본 논문에서는 기존의 연구되었던 기술 중에서 일반 용지 및 프린터를 이용하여 검증 가능한 영수증을 발급하는 전자투표 시스템을 구현하고자 한다.