• Journal of the Korea Society of Computer and Information
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• v.17 no.4
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• pp.91-98
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• 2012

A group key exchange (GKE) protocol is designed to allow a group of parties communicating over a public network to establish a common secret key. As group-oriented applications gain popularity over the Internet, a number of GKE protocols have been suggested to provide those applications with a secure multicast channel. Among the many protocols is Yi et al.'s password-based GKE protocol in which each participant is assumed to hold their individual password registered with a trusted server. A fundamental requirement for password-based key exchange is security against off-line dictionary attacks. However, Yi et al.'s protocol fails to meet the requirement. In this paper, we report this security problem with Yi et al.'s protocol and show how to solve it.

• Journal of the Korea Society of Computer and Information
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• v.16 no.8
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• pp.109-118
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• 2011

Recently, electronic documents are deployed in many areas. However, trust concerns arise owing to the fact that detecting whether an electronic document is modified or not is not an easy process. To facilitate this process, many word processors provide digital signature capabilities on themselves. However, there were not much research on the security of digital signature function of various programs including Microsoft Word and Hancom Hangul. Therefore, in this paper, we analyze the security of Microsoft Word and Hancom Hangul, and propose improvements for their digital signature schemes.

• Journal of the Korea Society of Computer and Information
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• v.17 no.9
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• pp.91-101
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• 2012

Key exchange protocols are essential for building a secure communication channel over an insecure open network. In particular, password-based key exchange protocols are designed to work when user authentication is done via the use of passwords. But, passwords are easy for human beings to remember, but are low entropy and thus are subject to dictionary attacks. Recently, Zhao and Gu proposed a new server-aided protocol for password-based key exchange. Zhao and Gu's protocol was claimed to be provably secure in a formal adversarial model which captures the notion of leakage of ephemeral secret keys. In this paper, we mount a replay attack on Zhao and Gu's protocol and thereby show that unlike the claim of provable security, the protocol is not secure against leakage of ephemeral secret keys. Our result implies that Zhao and Gu's proof of security for the protocol is invalid.

• Journal of Digital Convergence
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• v.13 no.1
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• pp.11-23
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• 2015

Recently the military is improving the policies of military culture for soldiers to lead a better military life. In this effect, 'division A' introduced 'goal-directed self development program'. This program is guiding the soldiers to set up personal mission in life not only in the military but also linked to the future, after being discharged from military service. Therefore the purpose of this research is to test the effect of this program on soldier's objective management, self esteem and satisfaction and to propose political strategies for creating healthier military culture. The research method was to compare and analyze the difference between two groups, 'division A'(experimental group), which operated the program, and 'division B'(controlled group) which did not operated the program. research targets were 488 soldiers in total, 257 soldiers in experimental group and 231 in controlled group. T-test(verification) and analysis of covariance was done with SPSS WIN 11.5 program with collected information. The result showed that the program has meaningful effect in every aspect mentioned above to the soldiers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2340-2349
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• 2009

In this paper we proposed a hopping routing scheme to resolve the hot spot problem for periodic monitoring services in wireless sensor networks. Our hopping routing scheme constructs load balanced routing path, where an amount of energy consumption of all nodes in the sensor networks is predictable. Load balanced routing paths can be obtained from horizontal hopping transmission scheme which balances the load of the sensor nodes in the same area, and also from vertical hopping transmission scheme which balances the load of the sensor nodes in the other area. The direct transmission count numbers as load balancing parameter for vertical hopping transmission are derived using the energy consumption model of the sensor nodes. The experimental results show that the proposed hopping scheme resolves the hot spot problem effectively. The efficiency of hopping routing scheme is also shown by comparison with other routing scheme such as multi-hop, direct transmission and clustering.

• Journal of Digital Convergence
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• v.16 no.12
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• pp.51-60
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• 2018

This study would like to know the relationship among interpersonal competency based self-understanding and acceptance of others, self leadership, stress-coping and military adjustment. For this, 1289 military trainee in the army training station were surveyed. In results, The first, the acceptance of others did not have a significant effect on the perform-will, but had a significant effect on the job satisfaction and self leadership. The self-understanding had a significant effect on perform-will, job satisfaction and self leadership. The second, self leadership mediated between interpersonal competency and military adjustment. The third, in case of the perform-will, the moderating effect was showed in self leadership when the stress coping level was high. But in case of the job satisfaction, it was showed in both high group and low. Implications of this study is that the interpersonal competency based self-understanding and acceptance of others, self leadership and stress coping can be the positive potential variables on the military adjustment.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.8 s.350
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• pp.13-18
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• 2006

[ $SnO_2$ ] and ZnO nanostructures were grown on the surface of thin film by heat treatment of metal Sn, Zn under Ar gas flow and $O_2$ at atmospheric pressure, respectively. The sensitivity of the $SnO_2$ thin film device on which grown nanowires to CO gas(5,000 ppm) was 50 % at the operating temperature of $200^{\circ}C$. In case of using Pt as catalysts, the sensitivity was enhanced and operating temperature was reduced(73 % at $150^{\circ}C$ ). The sensitivity of the ZnO nanorods device using Cu as catalysts to NOx gas was 90 % at the operating temperature of $200^{\circ}C$. It was found that the sensitivity to CO and NOx gases for the device on which grown nanostructures was much higher than those for general thin film device.

• Convergence Security Journal
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• v.17 no.3
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• pp.73-81
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• 2017

In April 2009, in the wake of President Obama's Prague speech, the international community held four nuclear sec urity summits from 2010 to 2016 to promote nuclear security and prevent nuclear terrorism. The Nuclear Security S ummit has made significant progress in preventing terrorists from attempting to acquire nuclear weapons or fissile materials, but it still has limitations and problems. To solve this problem, the international community should resume the joint efforts for strengthening bilateral cooperation and multilateral nuclear security regime, and the participating countries should strive to protect their own nuclear materials and fulfill their commitments to secure nuclear facilitie s. Second, the United Nations(UN), the IAEA(International Atomic Energy Agency), International Criminal Police Or ganization(INTERPOL), the Global Initiative to Combat Nuclear Terrorism(GICNT), and the Global Partnership(G P) must continue their missions to promote nuclear security in accordance with the five action plans adopted at the Fourth Nuclear Security Summit. Third, the participating countries should begin discussions on the management and protection of military nuclear materials that could not be covered by the Nuclear Security Summit. Fourth, the intern ational community must strive to strengthen the implementation of the Convention on the Physical Protection of Nuc lear Material(CPPNM) Amendment and International Convention for the Suppression of Acts of Nuclear Terrori sm(ICSANT), prepare for cyber attacks against nuclear facilities, and prevent theft, illegal trading and sabotage invo lving nuclear materials.

• Journal of Digital Convergence
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• v.15 no.12
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• pp.47-57
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• 2017

The purpose of this study was to investigate the difference of counselor-client's intimacy, empathy, and communication level when cognitive thinking trait between counselor and client is the same or not. For this purpose, 70 peer counselors of the S division conducted counseling training for 10 hours with 6 hours of education and 4 hours of practice. All counseling sessions were preceded by APL cognitive test, divided into two cognitive trait, followed by counseling with the same cognitive trait for two hours, and with a different cognitive for two hours. After each session, questionnaires were conducted. The results of this study showed that intimacy, empathy and communication level were significantly higher in counseling with the same trait as counselors than different. The results of this study are verifying the difference of the cognitive trait of the counselor and the client among the variables of the counselors influencing effect in the counseling process. Suggesting the importance of a counseling plan that takes into account the self-understanding of counselor and the trait of the client. Finally, the points of this study were discussed.

• Journal of the Korea Society of Computer and Information
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• v.25 no.6
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• pp.183-191
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• 2020

In this study, in order to obtain basic data on the development of a new hanbok skirt pattern for developing a customizing system, a new hanbok brand skirt pattern was compared and analyzed. After analyzing the patterns of six new hanbok brands, virtual simulation was performed to evaluate the appearance, clothing pressure, and airgap. As a result of analyzing the waist skirt patterns of commercial new hanbok brands A, B, C, D, E, and F, it was found that they were produced in different dimensions despite the free size skirt of the same design. The pattern of new hanbok waist skirt was composed of a flat pattern like the traditional hanbok. As a result of appearance evaluation, it was evaluated that there were significant differences between the patterns of the six brands in all the evaluation items on the front, side, and back. In the appearance evaluation, it was evaluated that the waist skirt of the B brand was excellent. As a result of examining the color distribution and airgap, it was evaluated that the airgap was large in most parts due to the characteristics of the waist skirt worn around the waist, and the garment pressure was low. In this paper, we propose a basic data for standardizing dimensions and patterns according to activation New Hanbok. It is thought that a unified pattern development based on the B brand pattern should be made.