• The Korean Journal of Air & Space Law and Policy
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• v.30 no.1
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• pp.151-180
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• 2015

South Korea is advancing the unmanned aircraft private commercial business. Unmanned aerial vehciles industry has been developing for several years also abroad. However, unmanned aerial vehciles industry, can be an accident occurs. Accident of unmanned aerial vehciles to occur material damage and casualties. Particularly if an accident because of a defect in the unmanned aerial vehciles has occurred, it is necessary to analyze the liability for this. The defect accidents unmanned aerial vehciles has been the different manufacturing and design product is intended, whether it is important how to prove to this. This is because, unmanned aerial vehciles are designed in any intent of the original, it is impossible to victims know. So imposing a responsibility to prove the design by the manufacturer intended consumer is not fair. Moreover, the consumer, it is necessary to prove only that the product is one that normally dangerous lacked safety can be expected. This is a detailed issue of judgment of defects of unmanned aerial vehciles, the manufacturer to bear the accountability. In the case where the defect on the display of the unmanned aircraft is a problem, and if it reasonable indication, it is not appropriate to be required to prove that it was possible to prevent damage to the victim.

• Journal of Engineering Education Research
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• v.10 no.2
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• pp.44-61
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• 2007

The present investigation is concerned chiefly with new curriculum development at the Department of Mechanical System & Design Engineering at Hongik University with the aim of enhancing creativity, team working and communication capability which modern engineering education is emphasizing on. 'Mechanical System & Design Engineering' department equipped with new curriculum emphasizing engineering design is new name for mechanical engineering department in Hongik University. To meet radically changing environment and demands of industries toward engineering education, the department has shifted its focus from analog-based and machine-centered hard approach to digital-based and human-centered soft approach. Three new programs of Introduction to Mechanical System & Design Engineering, Creative Engineering Design and Product Design emphasize hands-on experiences through project-based team working. Sketch model and prototype making process is strongly emphasized and cardboard, poly styrene foam and foam core plate are provided as working material instead of traditional hard engineering material such as metals material because these three programs focus more on creative idea generation and dynamic communication among team members rather than the end results. With generative, visual and concrete experiences that can compensate existing engineering classes with traditional focus on analytic, mathematical and reasoning, hands-on experiences can play a significant role for engineering students to develop creative thinking and engineering sense needed to face ill-defined real-world design problems they are expected to encounter upon graduation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.1
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• pp.18-31
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• 2018

Rotorcrafts have more severe crashworthiness conditions than fixed wing aircraft owing to VTOL and hovering. Recently, with the increasing demand for highly efficient transportation system, application of composite materials to aircraft structures is increasing. However, due to the characteristics of composite materials that are susceptible to impact and crash, demand to prove the crashworthiness of composite structures is also increasing. The purpose of present study is to derive the structural concept of composite subfloor for rotorcrafts and verify it. In order to design a crashworthy composite subfloor, the conceptual design of the testbed helicopter for the demonstration and the derivation of energy absorbing requirement were carried out, and the composite energy absorber was designed and verified. Finally, the testbed for the demonstration of a crashworthy composite structure was fabricated, and performed free drop test. It was confirmed that the test results meet the criteria for ensuring occupant survivability.

• The Journal of the Acoustical Society of Korea
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• v.30 no.1
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• pp.22-32
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• 2011

The present study examined the effects of the complexity of the 3D models on the results of acoustic simulation which is the predominant tool of the acoustical design of buildings. Also, the effects of the 3D model on the auralized sounds were investigated. In order to carry out the study, four 3D models with different levels of complexity were introduced for a real auditorium which have different numbers of surfaces in the persuit of the guidance of odeon room acoustic software. The set-up of models was also based on the level of transition order of the program. And the acoustic experiments were performed measuring room acoustic parameters including SPL, RT, C80, D50. Acoustic computer simulations were performed using four different models. Then, the results of the computer modeling were compared with the measured acoustical parameters. In addition, sound sources were recorded in the field and auralized sounds were made in convolution with the impulse source made from acoustic modeling. Then, subjective tests were undertaken using auralized sounds. As the results, it was found that the result of the acoustic simulation were closer to the real room acoustic properties when 3D model was more particularly made. For the subjective test, the listening materials were acknowledged as similar with the real sound source when more complex 3D model was used. Then, it could be concluded that the complexity of the 3D model affects the results of the acoustic modeling as well as subjective tests.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.10
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• pp.758-765
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• 2002

KITECH and ODS performed a study of internal and external noise prediction of the Korean high speed prototype test train(HSR 350X). The object of this study was 3 kinds of cars, trailer car(TT2), motorized car(TMI ) and power car(TPI) and the predicted noise was for the two different driving speeds in free field and tunnel conditions. Data of carbody design and noise sources were delivered from manufactures. Some of noise sources which were not available in the project team, were chosen by experiences of ODS. Internal noise level of each car was predicted for two cases i.e, at 300 km/h and 350 km/h. In addition sound transmission path and dominant noise sources were also investigated for each section of the car, which is circular shell typed part of whole carbody. In case of TT2, the dominating sound transmission path is the (floor in terms of structure-borne noise and air-borne noise. The main noise sources are structure-borne noise from the yaw-damper and air-borne noise from the wheel/rail contact, whereas the dominating sound transmission path of TMI are floor and sidewall below the window in terms of structure-borne noise. The main noise sources of TMI are structure-borne noise from motor/gear unit and the yaw-damper in the free field, and air-borne noise from the wheel/rail contact and structure-borne noise from motor/gear unit in the tunnel. Through the external noise prediction for the KHST test train formation, the noise form the wheel/rail contact is estimated as one of the major sources. In addition, the noise specification of sub-component was proposed for managing each sub-surpplier to reach the KHST noise requirement. The specification provide the sound power of machinery part and transmission loss of component of carbody structure. The predicted noise level in each case exceeded the required limit. Through this study, the noise characteristics of the test train were investigated by simulation, and then the actual test will be performed in near future. Both measured and calculated data will be compared and further work for noise reduction will be continued.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.3
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• pp.146-151
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• 2004

Cyclodextrin compounds including 2-hydroxypropyl-β-cyclodextrin(β-HPCD) though to be accelerate the biodegradation of PAHs molecule by increasing solubility of PAHs through detaining PAHs in their's cavity. However, only this mechanism is not sufficient to explain the enhancement of PAHs biodegradation by β-HPCD. To find out possible additional role of β-HPCD in the enhancement of PAHs biodegradation, biodegradation rates of pyrene and benzo[a]pyrene (B[a]P) by a PAHs degrading Novosphingobium pentaromtivorans US6-1 strain were compared between with and without addition of β-HPCD. Changes of bacterial biomass were also measured simultaneously. In addition catechol 1,2-dioxygenase activity was determined depending on pre-incubation conditions. As a result, β-HPCD accelerate the degradation rate of pyrene by strain US6-1 and especially the β-HPCD amendment was obligatory for the degradation of B[a]p. Bacterial biomass was responsible for β-HPCD, however, PAHs compounds such as pyrene and B[a]P did not contribute to the bacterial biomass. Catechol 1,2-dioxygenase specific activity of US6-l cells pre-cultured in MM2 medium containing l％ β-HPCD was higher than that of cells pre-cultured in ZoBell medium. The former case also showed similar activity compared to that of cells serially starved in MM2 medium after grown in ZoBell medium. These results imply that the presence of β-HPCD accelerate the degradation of PAHs by increasing the bacterial biomass as well as by increasing the water solubility of PAHs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.406-418
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• 2020

When developing weapons systems, it is important to implement the functions and performance of equipment suitable for development purposes, but it is very important to ensure that the equipment is capable of operating without any vacuum with reliability after development. Therefore, various activities are carried out to enhance reliability of equipment. Reliability is enhanced by using high-specification parts in development, reliability verification through analysis, and testing using development prototypes to reinforce and improve the parts that are lacking in equipment. However, recently, development schedules are shortened due to rapidly changing external conditions and technologies, and there are cases where sufficient reliability growth activities were not carried out due to problems such as cost. Examples are projects that perform reliability activities only in analytical methods (reliability, FMECA). In this paper, analyzing and testing methods for analysis and testing were carried out on the same equipment through FMECA and super-accelerated life test, the contents of reliability growth activity were derived, the results of design change/review were accordingly compared, the differences between the two methods were analyzed, and measures were proposed to strengthen reliable growth activities. It was concluded that reliable growth activities through analysis from the beginning of development and reliable growth activities through testing should be carried out at the completion of initial prototype production.

• Journal of Korean Medical classics
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• v.18 no.4 s.31
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• pp.155-165
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• 2005

진당시기대상한론치법적연구유(晋唐時期對傷寒論治法的硏究有): 왕숙화운용당시성행적(王叔和運用當時盛行的)‘한(汗), 토(吐), 하(下), 온(溫), 구(灸), 자(刺), 수(水), 화(火)’등팔법(等八法), 귀납료상한론적증치경험(歸納了傷寒論的證治經驗); 손사막근거자기적임상경험(孫思邈根據自己的臨床經驗), 파상한론적태양병편진행료(把傷寒論的太陽病篇進行了)‘이방명법(以方名法), 안법류증(按法類證)’, 저시해시기대상한론육경병치법적대표성적연구(這是該時期對傷寒論六經病治法的代表性的硏究), 저종연구유원시화력사적국한성(這種硏究有原始和歷史的局限性), 종중국의학대상한론육경병치법적연구력사고려(從中國醫學對傷寒論六經病治法的硏究歷史考慮), 저성위료후세적치법연구적선구자(這成爲了後世的治法硏究的先驅者), 구유비상대적영향(具有非常大的影響). 재송대대상한론치법적연구상(在宋代對傷寒論治法的硏究上), 기관건작용적의가유방안시화주굉(起關鍵作用的醫家有龐安時和朱肱). 타문대상한론치료원칙적천발(他們對傷寒論治療原則的闡發), 대륙경병적분석귀납(對六經病的分析歸納), 이급제시구체적치법상(以及提示具體的治法上), 도주출료공헌(都做出了貢獻). 방안시주장료응안인(龐安時主張了應按人), 지(地), 시제정치료적사상(時制定治療的思想); 주굉이(朱肱以)‘병유표본(病有標本), 치유선후(治有先後)’위치료원칙(爲治療原則), 여상한론상결합진행치료(與傷寒論相結合進行治療), 대후세의가산생료영향(對後世醫家産生了影響). 도료금원대성무기(到了金元代成無己), 류완소(劉完素), 왕호고등(王好古等), 대내경내용각자이사상관점(對內經內容各自以思想觀点), 분별안변증론치총결료육경병적치료규율(分別按辨證論治總結了六經病的治療規律), 동시대증후화방약진행료분석(同時對證候和方藥進行了分析), 천명료구체적육경병치법적병리전귀(闡明了具體的六經病治法的病理轉歸), 도유기독창성(都有其獨創性). 성무기용내경해석료상한론(成無己用內經解釋了傷寒論), 총결해기(總結解肌) 발한(發汗) 중제발한(重劑發汗) 해표행수(解表行水) 화해(和解) 공비 지열(止熱) 삼설등치법, 위후세대상한론치법적연구개벽료도로, 인이갱가명확화해적개념(因而更加明確和解的槪念), 병응용지금(幷應用至今). 류완소제창료주화론(劉完素提倡了主火論), 중시료상한론한(重視了傷寒論汗), 토(吐), 하삼법적연구(下三法的硏究), 창립료신량해표법(創立了辛凉解表法), 대후세온병치료적발전대래료흔대영향. 왕호고작위이수학파(王好古作爲易水學派), 운용장부적한열허실이론결합약미효능(運用臟腑的寒熱虛實理論結合藥味效能), 탐색료상한론육경병적치료규율(探索了傷寒論六經病的治療規律), 강조료양명병적익진액적치료원칙(强調了陽明病的益津液的治療原則), 대후세연구상한론치법급여료흔대적계발. 이상대상한론치법연구(以上對傷寒論治法硏究), 불근성위당시임상의학적선도(不僅成爲當時臨床醫學的先導), 이차성위료후세연구상한론치법적기초(而且成爲了後世硏究傷寒論治法的基礎).

• Journal of Satellite, Information and Communications
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• v.3 no.1
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• pp.41-47
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• 2008

Line-of-sight communications cannot easily support korean armed forces because of mountainous terrain. ADD(Agency for Defense Development) introduced ANASIS(Army Navy Air-force Satellite Information System) to meet the Korean warfighter's operational needs. Currently, army's military satcom terminal is designed for either fixed site or on-the-pause operation. The US army is under development of multi-band integrated on-the-move satellite terminals to let the army's communication capability to keep pace with globally deployable Joint Task Force for network-centric application. In this paper we analyzed X-band and Ka-band link and subsystem requirement. Our focus here is to describe key technical issues. Especially, On the basis of 3dB beam width of 0.9m antenna, Tracking accuracy and disturbances compensation signal processing on-the-move of Antenna Tracking system is analyzed. Also, protocol is analyzed that minimize blockage on the move due to an obstacle. when the received signal blocked, it stop to transmit burst signal and retransmit when blockage removed through received synchronization signal monitoring. Analyzed specification will be used to make prototype terminal to analyze risk for mass production

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.5
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• pp.595-602
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• 2017

In Korea, much research and development have occurred to enhance the technological competitiveness of tuna purse seining fisheries. Due to these efforts, fishing efficiency has been improved with the development of radar, sonar and global positioning systems for fish detection and revisions to the hull forms of tuna purse seiners. However, for skiff boats, net boats and speed boats, which are auxiliary working boats mounted on tuna purse seiners, technology has lagged behind relative to the modernization of the main vessel. In this study, the hull of an existing propeller-based net boat with steel wire net to protect tuna was changed to the hull of a water jet propulsion vehicle to reduce resistance and improve maneuverability. As a result, a prototype of a water jet propulsion option was produced according to the aluminum structure strength standards specified by the Ministry of Oceans and Fisheries, and safety was confirmed by performing a drop test. Moreover, through a sea trial test, an existing net boat was shown to have a speed of 12.0knots and a towing force of 2,545 kgf at 2,500 RPM. The prototype had a speed of 26.7 knots and a towing force of 2,011 kgf at 3,200 RPM, which satisfied the towing capacity standards of auxiliary working boats mounted on tuna purse seiners.