• Proceedings of the Optical Society of Korea Conference
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• 2006.07a
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• pp.239-240
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• 2006

• Proceedings of the Materials Research Society of Korea Conference
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• 1998.11a
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• pp.58-58
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• 1998

• Water for future
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• v.52 no.5
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• pp.36-41
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• 2019

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.9
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• pp.923-930
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• 2012

The wall heat transfer of backward-facing step laminar flows with different Prandtl numbers and a pulsating inlet is investigated by unsteady simulations. The inlet is perturbed by the variation of frequency and amplitude. Temperature-dependent transport properties are adopted. Various characteristics of the wall heat transfer are explained by the variation of the thermal boundary layer. For Pr < 1, the wall heat transfer of temperature-dependent properties is decreased compared to that of constant properties, whereas it increases for Pr < 1. In addition, the wall heat transfer increases depending on the pulsating amplitude. However, the results of frequency variation for St < 0.2 show that the heat transfer is strongly enhanced at a specific frequency. In particular, the increase in the wall heat transfer is strongly related to the root mean square of the fluctuations of the reattachment length.

• Journal of Digital Convergence
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• v.14 no.7
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• pp.475-484
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• 2016

The purpose of this article is to investigate how returning veterans with Post Traumatic Stress Disorder (PTSD) develop psycho-social issues and describe how helping professionals can assist them with re-adapting to the community. Based on a literature review, the author explores the causes of psycho-social issues of returning veterans with PTSD, reviews various ways of helping, and proposes critical factors that helping professionals should be aware of when intervening in psycho-social issues of returning veterans with PTSD. It is found that psycho-social issues of returning veterans with PTSD are closely related to their distrust and aversion to authorities. Group therapy can be used as a viable intervention for alleviating PTSD symptoms and derived psycho-social issues in terms that veterans with PTSD tend to more open with other group members who can share and understand unique experiences.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.2
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• pp.1-10
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• 2018

This study investigated the acoustic forcing effects on the liquid column breakup length and the trajectory of liquid jets in crossflows. Cold-flow tests with a single hole circular nozzle injector were carried out by changing the injection pressure and acoustic forcing amplitude. Additionally, spray images were obtained at 12 phase angles to investigate the influence of the phage angle. The results revealed that the liquid column breakup lengths generally decreased under the acoustic forcing conditions, in comparison to those under the non-acoustic forcing conditions. However, they were not affected by the variation in the phase angles. On the contrary, it was found that the acoustic forcing hardly influenced the liquid column trajectories.

• Polymer(Korea)
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• v.26 no.3
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• pp.353-359
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• 2002

High intensity ultrasound has been applied to a series of poly(ethylene oxide) (PEO)/water systems having different molecular weights of PEO. Major interest was focused on the effect of ultrasonic wane on the melt viscosity chemical structure and thermal properties of PEO. The expected role of ultrasound used in this study was to generate macroradicals of PEO chains by the formation and subsequent collapse of bubbles. It was found that the melt viscosity and chemical structure of PEO change significantly depending on the sonication time. For the prolonged sonication, PEO chains were significantly degraded and new end groups were formed by the interplay of various radical species. When the molecular weight of PEO was relatively higher, the crystallization rate was decreased and the intensity of the melting peak was reduced.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.1194-1197
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• 2009

Nowadays many Internet users have their own homepages and blogs on the Internet. Developers and designers offer a lot of options to users to increase their satisfaction. Do users prefer a lot of options? This study shows that users may prefer simple web-sites to complex web-sites. Moreover, users' attitudes can be affected by individual characteristics users have. This study focuses on one of the individual differences, computer anxiety. As a result, users who have high computer anxiety had more negative attitudes to web-sites than users having low computer anxiety had. This result emphasizes the importance of understanding users when designing interfaces.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.2
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• pp.77-81
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• 2009

Air-gap was introduced to suppress the saturation of the iron core comprising the flux-lock type superconducting fault current limiter (SFCL) with parallel connection of two coils. However, the air-gap makes the impedance of this SFCL decreased and can result in unusefulness of the SFCL. To analyze the current limiting characteristics of the SFCL with the air-gap, the experimental circuit for short-circuit test was constructed. Through the comparison with the current limiting characteristics of the SFCL without air-gap, the merit and the demerit of the flux-lock type SFCL with the air-gap were discussed.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04a
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• pp.607-609
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• 2002

일반적으로 부하 분산 정책은 사용자의 서비스 요청 특성에 관계없이 들어오는 그대로 처리 하고 있다. 본 논문에서는 이러한 것을 개선하기 위하여 차별 큐를 가진 최단 작업 우선 기 법을 제안하였다. 제안한 기법은 부하 분산 서버에 사용자의 서비스 요청이 들어오면 해당 요청의 처리시간을 파악하고 이미 들어온 서비스 요청들과 비교해서 먼저 처리가 완료될 수 있는 서비스 요청을 부하 분산 정책에 할당해주는 전략을 사용함으로써, 사용자들의 평균 응답 시간을 향상시키도록 하였다.