• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.10
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• pp.1862-1872
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• 2017

To overcome the limitations of the current Central Mobility Management (CMM) protocols, IETF has been discussing about the Distributed Mobility Management (DMM) protocols that the centralized mobility functions of Home Agents (HA) are distributed to network edges closer to mobile users. The DMM protocol has some advantages of low-cost traffic delivery and high scalability. However, it faces several problems such as a high signaling cost and a complex address management. Especially, users moving at a high speed and with long-live sessions can make these problems worse. To reduce the high signaling cost for long-live sessions, we propose a novel hybrid DMM protocol allocating different mobility anchors according to the session durations. In this paper, we analyze the performance of the proposed hybrid DMM protocol and show superior performance with respect to the signaling cost.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.2
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• pp.329-341
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• 2017

A multi-server architecture has been proposed to increase the efficiency of resources due to the rapid growth of computer networks and service providing servers. The smartcard-based authentication protocol in the multi-server environments has been continuously developed through various studies. Recently, Chun-Ta Li et al proposed an authentication protocol that solves Xiong Li el al's authentication protocol vulnerability to user impersonation attack and session key disclosure attack. However, Chun-Ta Li et al's authentication protocol has a problem with user impersonation in the vulnerability analysis and has an unsuitable authentication process. Therefore, this paper proposes a smartcard-based authentication protocol in the multi-server environments that solves the denial of service attack and replay attack vulnerabilities of the authentication protocol proposed by Xiong Li et al.

• Korean Journal of Applied Biomechanics
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• v.27 no.1
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• pp.19-23
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• 2017

Objective: The aim of this study was to investigate the relationship between the ball velocity and the upper extremity kinematics for both dominant and non-dominant side in inexperienced participants about an overarm throwing task. Method: Seven women who are inexperienced in overarm throwing participated in this study (Age: $25.1{\pm}2.4years$, Height: $160.8{\pm}3.5$; Weight $56.5{\pm}7.8$). Participants visit the laboratory for three days with one day rest between test sessions. Whole body 3-dimensional (3D) motion capture was recorded during the overarm throwing trials with ten cameras Vicon motion analysis system (T-10, T40, Oxford Metrics Ltd, UK). Total 45 overarm throwing were recorded for each side for each test session. Ball speed also was measured 3 meters away behind the subjects and recorded for every trial. Results: Mean ball velocity was higher for dominant hand compared to non-dominant hand (p <.05). Trunk segment variables (maximum angles and angular velocities) showed the most consistent relationship with the ball velocity. Conclusion: The importance of the trunk segment during the throwing activities can be seen in some individuals. But inconsistent results between subjects emphasize the importance of the individuals' movement patterns especially for bilateral sports. The future studies should be conduct about the sequence of segments, kinetic variables and effect of training.

• Journal of the Korean Society of Physical Medicine
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• v.10 no.4
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• pp.69-80
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• 2015

PURPOSE: The purpose of the present study was to apply joint mobilization in a sitting position and in a prone position to patients with acute mechanical neck pain and compare the immediate treatment effects in these two positions. METHODS: After the baseline was assessed, 46 patients were randomly assigned to two groups: experimental group I ($n_1=23$) for joint mobilization in the sitting position and experimental group II ($n_2=23$) for joint mobilization in the prone position at the symptomatic cervical level. The patients in both groups received treatment by unilateral posterior-anterior gliding for 30 seconds per trial, 10 trials per session, for a total of 5 minutes, and two trials of 10 active extending motions with distraction per trial. RESULTS: In the Wilcoxon signed-rank test, all the pain and physical function variables were significantly improved after intervention in both groups (p<.05). In the Mann-Whitney U test, which compared the differences before and after the intervention between the two groups, experimental group I showed significant improvement over experimental group II in resting pain (p<.01), satisfaction with the treatment (p=.01), left rotation (p<.01) and CCFE (p<.01). In the analysis of covariance results, experimental group I showed significant improvement over experimental group II in the most painful motion pain (p<.01) and the most painful quadrant motion pain (p<.01). CONCLUSION: These outcomes suggest that joint mobilization should be applied in sitting positions for patients with acute mechanical neck pain that feel pain during sustained positions, extension or rotation.

• Journal of the Korean Society for Library and Information Science
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• v.48 no.1
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• pp.257-276
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• 2014

The purpose of this study is to investigate the patterns and barriers of the Internet for the elderly adults in Korea. Data was collected through the face to face interview using a questionnaire for the residence of Daegu and Kyungsang Buk-Do areas targeted over the 60-years-olds elder adults. A total of 119 valid response data were analyzed with the descriptive statistics and the group differences by age and gender using SPSS 18.00. It found that the most of the elder adults access the Internet to seek the entertainment contents, the knowledge-related contents, and the cultural and art contents. They spend most of the Internet online session to do searching information and enjoying movie and music. However, there were age differences and gender differences within the subjects. The complexity of computer and the Internet usage is one of the barriers for the Internet access, and they suggest that a customized education and training courses of computer literacy for the elderly adults would be the ways of resolve those obstructions.

• Journal of Educational Research in Mathematics
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• v.27 no.4
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• pp.701-725
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• 2017

Students need to have opportunities to share their ideas with peers by taking part in the conversation voluntarily that is, by persuading others and reflecting the consequences. Recognizing the importance of this point, this study intended to examine students' argumentation occurring in the process of performing tasks in the math classroom. Also, it tried to explore the types of the argument that students used in the classroom and the reason why they employed them with a focus on 'rebuttal', which is one of the six elements of the argument scheme such as claim, data, warrent, backing, qualifiers, and rebuttal. The analysis of argumentation is based on the five argumentation schemes suggested by Verheij(2005). The experimental class was conducted twice a week with four participants who are third grade middle school students. In the argumentation class students were promoted to address two different kinds of geometrical tasks. After the second session of class, the researcher conducted the semi-structured interview. Accordingly, this study contributes to the existing research by making students to have concrete and active argumentation while obtaining the sound understanding of the argumentation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.5
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• pp.445-458
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• 2012

The objective of GPS control surveying is ultimately to determine coordinate sets of control points within targeted accuracy through a series of observations and network adjustments. To this end, it is of equivalent importance for the accuracy of these coordinates to be realistically represented by using an appropriate method. The accuracy representation can be quantitively made by the variance-covariance matrices of the estimates, of which features are sensitive to the mathematical models used in the adjustment. This paper deals with impact of functional and stochastic modeling techniques into the accuracy representation of the GPS control surveying with a view of gaining background for its standardization. In order to achieve this goal, mathematical theory and procedure of the single-baseline based multi-session adjustment has been rigorously reviewed together with numerical analysis through processing real world data. Based on this study, it was possible to draw a conclusion that weighted-constrained adjustment with the empirical stochastic model was among the best scheme to more realistically describe both of the absolute and relative accuracies of the GPS surveying results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.529-546
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• 2016

The aim of this study was to development a program to improve the positive psychological capital of university students and its effects. The program to improve the positive psychological capital of university students was developed based on the systemic counseling program development model. For this purpose, the program to improve the positive psychological capital was carried out a total of 6 times (90 minutes per session) once a week for 24 university students at "C"university located in Gangwon-do, which was divided into 2 groups. In this study, the data were collected through a pretest and a posttest and, data analysis was performed using SPSS 20.0 ver. Based on the results, the program to improve the positive psychology capital was effective in increasing the positive psychology capital. Finally, the implications of the results, as well as the significance and limitations of the present study are discussed.

• Journal of Families and Better Life
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• v.19 no.5
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• pp.239-258
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• 2001

The purposes of this study are first, to develop the group counseling program based on Satir’s family sculpture technique, second to investigate the therapeutic factors of Satir’s family sculpture in group counseling. To perform this study, 8 session of time limited(3 hours) group counseling were carried out. There were 12 participants in this group. The major findings were as follows: 1) the rank order fro therapeutic factors were university, group cohesiveness, instillation of hope, family reenactment, self-understanding and altruism. 2) through the family sculpture technique, group participants saw their communication patterns. They found out that use communication patterns to hide their low self-esteem. They learned the alternative communication style. 3) the participants developed the sense of self-disclosure, empathy and trust in the group. Self disclosure, empathy and trust facilitated a deeper level of therapeutic group interaction. 4) in observing their group members do their family sculpture, participants found out that every family has some problem that the family conflict is universal thing, 5) the participants had opportunity to share their feelings that were hidden deep inside Intensive emotions following self disclosure led to catharsis, 6) the participants developed a good feeling toward their group and it led to group cohesiveness. 7) through the family sculpture technique, the participants gained a better understanding on their role and position within their families 8) through the family sculpture technique, they gained a better understanding of their family. They found their family members’ psychological positions and unfinished emotional businesses and thus they could restructure their family sculptures. 9) the participants had the opportunity to feel what it is like to become parents themselves, They became to see their parents as individuals. 10) the participants acted out what they wanted to do but could not do in the past. They saw the possibility of change and development in themselves.

• Journal of Radiation Protection and Research
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• v.34 no.3
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• pp.95-101
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• 2009

Protective behavior of radiological technologists against radiation exposure is important to achieve reduction of the patient doses without compromising medical achievements. This study attempts to provide a basic model for the sophisticated intervention strategy that increases the level of the protective behavior of the technologists. The model was applied to real situations in Korea to demonstrate its utility. The results of this study are summarized as follows: First, the protective environment showed the highest relationship in the factors considered, r=0.637 (p<0.01). Secondly, the important factors were protective environment in environment characteristics, expectation for the protective behavior 0.228 (p<0.001), self-efficacy 0.142 (p<0.001), and attitude for the protective behavior 0.178 (p<0.001) in personal characteristics, and daily patient -0.112 (p<0.001) and number of the participation in the education session for the protective behavior 0.074 (p<0.05). Thirdly, the final protective behavior model by a path analysis method had direct influence on the attitude 0.171 (p<0.01) and environment 0.405 (p<0.01) for the protective behavior, self efficacy 0.122 (p<0.01), expectation for the protective behavior 0.16 (p<0.01), and self-efficacy in the specialty of projects 0.154 (p<0.01). The acceptance of the model determined by the absolute fit index (GFI), 0.969, and by the incremental fit index (CFI), 0.943, showed very significant levels. Value of $x^2$/df that is a factor applied to verify the acceptance of the model was 37, which implies that the result can be accepted in the desirable range. In addition, the parsimonious fit index configured by AGFI (0.890) and TLI (0.852) was also considered as a scale that accepts the model in practical applications. In case of the establishment of some specific intervention strategies based on the protective behavior model against harmful radiation effects proposed in this study, the strategy will provide an effective way to prevent medical harmful radiation effects that could cause severe injuries to people.