• Cross-Cultural Studies
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• v.19
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• pp.313-338
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• 2010

Attitudes toward target language culture and motivation have been known as important factors in second or foreign language learning. In this study, cadets' attitudes toward the target language community and culture were investigated to find out any relationships with English achievement. Integrative or instrumental motivation in foreign military context was investigated to determine which motivation was more positively related to English proficiency. Cadets' responses were shown highly positive and internally consistent in most cases. Military cadets' attitudes toward American culture were statistically significant and could predict their English achievement. Even though integrative motivation was statistically significant, correlation with English achievement was low. However, instrumental motivation was not significant. This result implies that attitudes toward culture is an important factor in foreign language learning and integrative-instrumental motivation dichotomy might not be enough to explain specific context like cadets' English learning situation at Korea Army Academy at Youngcheon.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.534-537
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• 2009

Clustering protocol of Wireless sensor networks(WSNs) can not only reduce the volume of inter-node communication by the nodes's data aggregation but also extend the nodes's sleep times by cluster head's TDMA-schedule coordination. In order to extend the network lifetime of WSNs, we propose CHS algorithm to select cluster-head using three variables. It consists of initial and current energy of nodes, round information, and total numbers which have been selected as cluster head until current round.

• Proceedings of the ESK Conference
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• 1992.10a
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• pp.22-25
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• 1992

항공산업은 그 특성상 고도의 신뢰성, 안정성이 요구되며, 이를 충족시키기 위하여는 복잡하고 정밀한 구조를 가져야 하므로 다른 산업제품과는 비교가 안될 정도로 그부가가치를 가지고, 타 산업에의 기술 파급 효과가 역시 지대하다. 따라서, 우리나라와 같이 부존자원이 빈약하나 인적 자원이 우수하고 풍부한 나라에서는 자원절약형 산업인 항공산업의 타당성을 검토, 장기적인 육성방안을 수립하여 추진하는 것은 시대적인 요구라 할 수 있다. 이러한 요구에 따라 국방과학연구소에서 공군의 초, 중등훈련기 개발을 추진 중에 있음은 KFP(Korea Fighter Program)사업과 함께 매우 중요한 의미을 갖는다. 이와 같은 시점에서 한국인의 인체특성에 보다 적합한 항공기의 개발은 가장 시급한 과제이며, 이 문제점을 극복하기 위한 기본연구로 조종실 내부설계에 필요한 기준점 및 치수, MIL-SPEC에서 규정하고 있는 기준치를 분석하였으며 실제 항공기(F-5, F-4, F-16)칫수를 측정하여 이를 정면도, 측면도, 평면도로 제시하고, 항공기 제어계통인 조종간, 동력제어기, 러더페달 및 조종석의 실제 측정치와 공군 조종사의 인체측정치를 비교, 평가하였다. 또한 전투기들의 정면 계기판과 좌, 우측의 제어판의 표시장치 및 조작기들을 기능별로 구분하여 각 요소별 제한조건 및 설계지침들을 비교, 분석하였다.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.7 no.3
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• pp.151-159
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• 1978

A heat transfer model for the case of simultaneous vibration of both the heated surface and its surrounding medium is constructed and the dimensional analysis is applied to this model in order to and the governing dimensionless Parameters in which the vibration effects the heat transfer. In the second Part of this study, an experimental investigation of the effect of vibration on natural convective heal transfer from spheres has been performed for the case of the external oscillatory motion being imposed on the heated surface which is immersed in an otherwise undisturbed air, The ranges of the experimental variables were: temperature difference 10 to $120^{\circ}C$; vibration frequency 10 to 120Hz; displacement amplitude 1.3 to 12.5mm. Three different diameter aluminum were used as the experimental models. Improvements in heat transfer due to vibration were observed, with the maximum increase being 330 Percent. A dimensionless correlation describing the measured heat transfer data is given.

• Journal of the Korea Institute of Military Science and Technology
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• v.26 no.2
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• pp.139-148
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• 2023

Safety standards for long-range artillery ammunition test and training sites follow the US artillery shooting range safety zone standards. Although the South Korean geographical conditions of shooting ranges are different from those of the United States, there is no safety standard reflecting the South Korean topographical characteristics. Probable error associated with the shooting range, trajectory should be considered in establishing the safety standards. In this study, we present the safety standards for the ammunition testing site suitable for the Korean situation, with applying a concept of trajectory and probable error differed by ammunition type, which are currently confirmed by the South Korean Army's artillery shooting.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.13 no.4
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• pp.209-214
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• 1984

Friction factors and equivalent sand roughness of PVC pipe fittings have been studied by experiments in the Reynolds number range of $2,000\~70,000$. PVC pipe fittings studied are straight pipes, $90^{\circ}$ elbows and tees with 15, 25, and 40mm in norminal diameter, all manufactured in Korea with KS mark approval. Equivalent relative roughness of PVC pipes obtained lies between smooth pipe and 0.002. The study shows that equivalent sand roughness of PVC pipes increasses in proportion of the square root of pipe diameter , and can be approximately abtained by multiplying 4 to the root mean square value measured by metal surface roughness tester. Loss coefficient of PVC $90^{\circ}$ elbows decreases slowly with increasing Reynolds number. Loss coeffiicent of tees is a function of ratio of flow rates and Reynolds number.

• Journal of the military operations research society of Korea
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• v.25 no.1
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• pp.14-28
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• 1999

Statistical data have shown that most of aircraft accidents attributed to the spatial disorientation result from visually restricted environments such as a flight amid clouds or a night flight, in particular during roll maneuvering. This study investigates the time necessary for a flighting pilot to recognize a sloped status as a horizontal status on the condition that the roll maneuver is operating when the visual sense is blocked In this study, aspects which affect such disorientation phenomena are examined. The result of this study shows that a pilot is rushed into a somatogyral illusion when a certain time elapses with visual sense blocked, and that as a speed of the flight increases and a bank of aircraft decreases, so a rushing time increases rapidly.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.46-47
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• 2020

Now a days, Lots of research about 4th industrial revolution are progressing. Attempt of technologies on construction engineering field, such as construction management by drone, building equipments based on the IoT technology and etc., are continuously tried by government and private enterprises. Meanwhile, the application of advanced technologies on the military facilities should be reviewed cautiously, because of the national defense environment such as military security. Therefore, this study aim to understanding of present status of military facilities for introduction of 4th industrial revolution technology. To achieve the aim of the study, question investigation targeting working groups for military facility management is conducted.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2020.11a
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• pp.42-43
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• 2020

현재, 전 세계적으로 자율운항선박(Maritime Autonomous Surface Ship, MASS)이 연구 개발되고 있다. 육상원격제어 시스템(Shore Remote Control System, SRCS)은, 비상 시 육상에서 원격으로 자격을 갖춘 원격제어사관(Remote Control Officer, RCO)이 MASS를 제어하기 위한 시스템이다. SRCS 개발을 위해서는 SRCS 운영 중에 발생 가능한 제어지연(control delay)에 대한 검토가 필요하다. 본 연구의 목적은 SRCS의 설계에 요구되는 제어지연 특성을 분석하고 정량화하기 위한 제어지연 모델을 구축하는데 있다. 먼저, SRCS의 제어지연 모델을 구축하고, 이를 통하여 제어지연의 특징을 분석하여 최적의 SRCS에 요구되는 다양한 제어특징을 검토하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.154-154
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• 2022

2019년 9월 8일 자동차운반선 골든레이호가 미국 브런즈윅항(Brunswick)항에서 출항 도중 전도되는 사고를 입었다. 도선사와 선원 23명은 모두 구조되었으나, 사고선박은 복구 불가로 전손(해체)처리 되었다. 미연방교통안전위원회(NTSB)는 담당사관이 선박 복원성 계산 프로그램에 평형수 양을 잘못 입력하였고, 충분한 GM 부족으로 선회 중 발생한 경사모멘트에 대응하지 못해 전도된 것으로 추정하였다. 우리나라 중앙해양안전심판원의 특별조사부에서도 미국과 동일한 원인에 의해 전도된 것으로 판단하였다. 본 연구에서는 골든레이호와 유사한 선박을 대상으로 상황별 GM를 계산하였고, 상황별/속력별 최대 횡경사각을 계산하였다. 선속 10노트 이하에서는 GM값이 작은 상황에서도 전도 위험은 높지 않았다. 다만, 13노트 이상이 되면 20도 이상의 횡경사각이 발생하여 전도 위험이 높아짐을 알 수 있었다. 이번 골든레이호 전도사고와 같은 사고를 방지하기 위해서는 담당사관이 복원성 계산능력을 충분히 갖출 수 있도록 복원성에 대한 교육 및 훈련을 강화할 필요가 있으며, 복원성 계산과정에서 발생할 수 있는 오류를 확인하기 위한 검증 절차를 선박과 회사에서 마련할 필요가 있다.