• 한국전자파학회논문지
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• 제30권4호
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• pp.300-306
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• 2019

얇은 도체 평판에 소형 리지 원형 개구, H-형태 개구, U-형태 개구, 예루살렘 십자형 개구와 같은 다양한 투과 공진 개구에 대하여 개구 모양에 무관하게 투과 단면적은 해석적으로 $2G{\lambda}^2/4{\pi}$로 주어지게 된다. 이러한 표현식에 대해 MOM 방법을 사용하여 계산한 결과와 비교하여 일치함을 확인하였다. 또한 두꺼운 도체 평판 내에 투과 공진기 구조에 대해 투과 단면적을 연구했으며, 투과 효율 관점에서 이들 두 소형 개구 구조 간에 동등함을 보였다.

• 비교문화연구
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• 제20권
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• pp.323-346
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• 2010

This study reviews critical literatures regarding Asian cinema, focusing on studies of Japanese cinema, to show that Western scholarship on non-Western national cinemas have been divided into two approaches: traditionalism and modernism. It argues that such a division is not merely a critical tendency but indicative of the fact that a national cinema is an internally divided construct. To support the point, this study examines Chinese film studies conducted by Chinese film critics and the history of South Korean cinema during the 1970s and 80s. Then, it proposes the hegemony model to theorize the inner structure of national cinema. It finally suggests the possibility of comparative film study that the national cinema thesis may activate.

• Journal of Information Technology Applications and Management
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• 제11권1호
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• pp.83-100
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• 2004

Understanding characteristics of Internet businesses from a cross-cultural perspective could offer valuable insights on developing business strategies and policies. This work is concerned with revealing divergence and convergence of Internet businesses in their financial performance, given organizational conditions and cultural context. For this, we studied the association between static organizational attributes (core activity, origination, firm age, and industry type) and a firms financial performance (gross revenue and net income). Relevant data was gathered from representative Internet firms in Korea and U.S. Data analysis indicated that, besides industry type, overall connection between selected organizational variables and financial performance was weak. Cross-national comparison showed that Korean firms financial performance was comparable to U.S firms during the period of economic turbulence. A noticeable difference was that Korean Internet firms and their business models were more service-oriented than U.S. counterparts.

• 설비공학논문집
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• 제29권6호
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• pp.279-288
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• 2017

Heat generation rate in a telecommunication cabinet increases due to the continued usage of mobile devices. Insufficient removal of heat intensifies the cabinet temperature, resulting in the malfunction of electronic devices. In this study, we assessed both aluminum and plastic heat exchangers used for cooling of the telecommunication cabinet, and compared the results against theoretical predictions. The aluminum heat exchanger was composed of counter flow parallel channels of 4.5 mm pitch, and the plastic heat exchangers were composed of cross flow triangular channels of 2.0 mm pitch. Samples were made by installing two plastic heat exchangers in both series and parallel. Results showed that the heat transfer rate was highest for the series cross flow heat exchanger, and was least for the aluminum heat exchanger. The temperature efficiency of the series cross flow heat exchanger was 59% greater than that of the aluminum heat exchanger, and was 4.3% greater than that of the parallel cross flow heat exchanger. In contrast, the pressure drop of the parallel cross flow heat exchanger was significantly lower than other samples. The heat exchange efficiency was also the largest for the parallel cross flow heat exchanger. The theoretical analysis predicted the temperature efficiency to be within 3.3%, and the pressure drop within 6.1%.

• Journal of Korean Biological Nursing Science
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• 제13권1호
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• pp.1-7
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• 2011

Purpose: The purpose of this study was to compare the hypertrophic effects of low-intensity exercise on weight, myofibrillar protein content and Type I, II fiber cross-sectional area of hindlimb muscles of rats between every other day exercise and every day exercise. Methods: Adult male Sprague-Dawley rats were assigned to 1 of 3 groups: control group (C, n=6), experimental group 1 (E1, n=7) and experimental group 2 (E2, n=7). Rats in E1 group had 7 sessions (every other day) and those in E2 group had 14 sessions (every day) of exercise in which they ran on a treadmill for 30 min/day at 10 m/min. Results: Muscle weight, cross-sectional area of type I fiber and myofibrillar protein content of soleus and myofibrillar protein content of plantaris in E1 group, and myofibrillar protein content of soleus and cross-sectional area of type I fiber of plantaris in E2 group were greater than those in C group. Cross-sectional area of type I fiber of soleus of E1 group was higher than E2 group while cross-sectional area of type I fiber of plantaris of E2 group was higher than E1 group. Conclusion: Hypertrophy of hindlimb muscles occurs from every other day exercise similar to every day exercise.

• 대한조선학회논문집
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• 제44권6호
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• pp.579-589
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• 2007

Contrary to the conventional single-point measuring devices such as LDV, pitot-tube, hot-wire, etc., it would be possible to measure instantaneously 3-D flow fields with a stereoscopic PIV system. In this paper, we present an analysis algorithm for a stereoscopic PIV system using the normalized cross-correlation (NCC) and a 3-D calibration based reconstruction method. The evaluation method based on NCC is one of the most accurate correlation-based methods. We validated the developed algorithm through a benchmarking comparison with 3-D artificial SPIV images and calibration target images.

• 디지털융복합연구
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• 제9권4호
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• pp.69-76
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• 2011

본 연구에서는 학습이나 교육과 관련된 인터넷 이용에 대한 이해를 높이기 위한 목적으로 한국, 미국, 캐나다 대학생들의 교육용 인터넷 이용의 주요 동기요인에 차이가 있는가를 확인하고, 각각의 요인에 대한 특성을 파악하였다. 더 나아가 본 연구에서 확인된 동기요인이 3 개국 대학생들의 인터넷에 대한 태도와 사용 의지에 미치는 영향 정도의 차이를 파악하고, 이차적으로 인터넷에 대한 태도와 사용의지가 이용 성과향상에 얼마나 영향을 미치는가를 확인했다. 본 논문의 결과는 3 개국 대학생의 인터넷 이용에 영향을 주는 요인의 이해를 돕고, 문화적 차이에 따른 인터넷 사용의지와 성과 인식의 차이 여부를 확인하는 데 도움을 줄 것이다.

• International Journal of Precision Engineering and Manufacturing
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• 제7권4호
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• pp.23-27
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• 2006

Rubber is used in many industrial products, such as hoses, rubber belts, and oil seals. In particular, more than 200 rubber parts are used in automobiles. The design technology of these parts is largely dependent on field experience, which leads to lengthy and expensive developing procedures. However, with the help of recent developments in nonlinear computer analysis, new rubber products can be developed at low cost. In this study, rubber injection molding design variables, such as location and number of gates, were optimized using computer-aided engineering with the cross-WLF equation to produce CLIP rubber products made from ethylene propylene diene monomer(EPDM). The validity of the proposed design was evaluated by comparison with actual forming results.

• Restorative Dentistry and Endodontics
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• 제42권3호
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• pp.216-223
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• 2017

Objectives: The aim of this study was to compare the mechanical properties of various nickel-titanium (NiTi) files with similar tapers and cross-sectional areas depending on whether they were surface-treated. Materials and Methods: Three NiTi file systems with a similar convex triangular cross-section and the same ISO #25 tip size were selected for this study: G6 (G6), ProTaper Universal (PTU), and Dia-PT (DPT). To test torsional resistance, 5 mm of the straightened file's tip was fixed between polycarbonate blocks (n = 15/group) and continuous clockwise rotation until fracture was conducted using a customized device. To evaluate cyclic fatigue resistance, files were rotated in an artificial curved canal until fracture in a dynamic mode (n = 15/group). The torsional data were analyzed using 1-way analysis of variance and the Tukey post-hoc comparison test, while the cyclic fatigue data were analyzed using the Mann-Whitney U test at a significance level of 95%. Results: PTU showed significantly greater toughness, followed by DPT and G6 (p < 0.05). G6 showed the lowest resistance in ultimate torsional strength, while it showed a higher fracture angle than the other files (p < 0.05). In the cyclic fatigue test, DPT showed a significantly higher number of cycles to failure than PTU or G6 (p < 0.05). Conclusions: Within the limitations of this study, it can be concluded that the torsional resistance of NiTi files was affected by the cross-sectional area, while the cyclic fatigue resistance of NiTi files was influenced by the surface treatment.

• 천문학회보
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• 제33권1호
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• pp.38.1-38.1
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• 2008