• Journal of Navigation and Port Research
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• v.36 no.10
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• pp.873-881
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• 2012

This study is about the case study on the application of modular system to the superstructure of floating architecture in Europe. There are many restraints in the onsite construction of floating architecture. Then, various industrialized construction methods are needed to reduce the portion of the onsite construction in floating architecture. Among the various industrialized construction methods, the modular system can be more suitable for floating architecture. At this background, this study analysed the European cases of the application of modular system and classified the types of applied modular system. As a result, this study could classify the three types of modular system, such as, building unit modular, space unit modular and planning concept modular, and define the characteristics of three types by comparing with each other.

• Computational Structural Engineering
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• v.11 no.1
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• pp.38-45
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• 1998

최근 국내외에서 활발히 개발되고 있는 지진격리 시스템은 원자력 발전소, 교량, 중요한 공공건물 등의 지진피해를 최소화하기 이하여 널리 적용되고 있다. 그리고 다른 방법에 비하여 경제성 및 효율성이 우수하기 때문에 관련 연구 및 응용이 활발히 진행되고 있다. 이에 따라 국내외에서 격리시스템의 비선형성과 구조물의 불연속성을 고려한 지진격리 구조물의 해석을 통한 거동을 규명하는 연구가 과거 수년간 활발히 진행되어 왔다. 당사(금호건설)는 상부하중 지지능력과 감쇠능력이 우수한 지진격리장치를 개발하였으며 지진격리장치를 설치한 교량의 지진해석을 수행하여 본 지진격리 시스템의 이론적 성능을 파악하였다. 본 수치해석은 CrayC94에 탑재된 비선형 해석에 뛰어난 것으로 알려진 ABAQU를 이용하였다. 본 지진격리 시스템은 적층고무받침(Laminated Rubber Bearing)과 PTFE 미끄럼받침으로 구성되어 있으며, 적층고무받침은 주로 복원력을 제공하며 PTFE 미끄럼받침은 상부하중을 지지하며 마찰감쇠를 제공하여 에너지를 소산하는 역할을 한다. 본 수치해석에서는 선형스프링과 마찰요소를 이용하여 각각을 모형화하였다. 개발된 지진격리 시스템이 주로 사용될 상판자중이 무거운 다경간 연속 PC Box Girder교를 모델교량으로 선택하여 해석을 수행하였으며 수치해석에 사용된 격리시스템의 사전에 수행된 동특성 실험결과를 활용하였다. 이러한 해석을 통하여 이론적 효율성을 파악할 수 있었다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.3
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• pp.221-231
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• 2021

In the present study, numerical simulation was performed to investigate aerodynamic characteristics of a ducted fan-upper/lower vanes system in hover. Sensitivity analysis of aerodynamic forces for a system component was conducted with the deflection angle of upper vanes varying but at the constant rotational speed and the collective pitch angle of fan blades. Then, vane control performance and duct airload distributions were analyzed in detail to physically understand operating mechanisms of individual vane and interference effect between duct and vanes. Finally, new control concept of operating upper vanes has been proposed to improve the control performance of the full configuration. It is found that the side force and rolling moment of upper vanes increase linearly with the variation of those deflection angle; however, the total side force is significantly small due to the reaction force acted on the duct. It is also found that upper vanes close to the duct contraction side have a key role in changing vane control forces. It is revealed that the duct suction pressure is induced by the interaction with the suction side of upper vanes, while duct pressure recovery by the interaction with the pressure side, leading to increase in duct asymmetric force. When four upper vanes are kept in situ at 0° deflection angle or removed, the total control performance was improved with duct asymmetric force reduced and the total magnitude of roll remarkably increasing up to 80%.

• Journal of Aerospace System Engineering
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• v.13 no.6
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• pp.43-51
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• 2019

The aircraft vertical acceleration from the excitation of the road surface in the taxing mode is a main factor with a negative effect on the boarding quality of pilots and passengers. In this paper, we propose an appropriate control method to improve the boarding quality of the MR damper landing gear. The proposed control method is Skyhook Control Type 2, which feeds the aircraft vertical acceleration back in addition to the aircraft vertical velocity. Since Skyhook Control Type 2 factors the velocity and acceleration of the upper mass, it can be expected to exceed the control performance of the existing Skyhook Control that factors only the upper mass velocity. For the simulation, the bumper type road surface was selected as a ground surface, and the landing gear model constructed with RecurDyn and the controller designed with Simulink were co-simulated. The control effect of Skyhook Control Type 2 was verified by comparing and analyzing the RMS and maximum value of the upper mass acceleration according to the taxing speed and control method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.512-513
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• 2017

In this paper, an automatic sowing system which arranges the seeds gathered using inhaling technique, on the upper part of cells in trays, is developed to improve the sowing efficiency. In the system, the seeds in inhaled into the vacuum drum, then the seeds are exhausted and arranged on the rotating tray, resulting in rapid sowing system. Also, the velocity control algorithm for the conveyor belt transporting tray is developed to compensate the velocity error generated while the belt is carrying the tray. The velocity control algorithm controls the pulses applying to the stepper motor rotating the drum.

• Journal of the Korean Society of Systems Engineering
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• v.2 no.1
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• pp.42-47
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• 2006

Advanced military nations have developed anti-tank smart munitions to maximize the effectiveness of the tank combat. In this paper we introduced new munition models (KSTAM) for arrack on the top of the tank and analyzed those operation research. To understand the adaptation to the future tank munition we have performed a trade-off study using the proposed models for smart tank munitions which have been developed or are being developed in advanced nations.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.239-242
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• 2011

본 연구에서는 모듈러 강교량의 상부구조 구성요소에 대한 정보의 교환, 검색, 공유가 가능한 데이터사전을 구축하였다. 표준모듈의 계층정의를 위해 기존 교량분류체계를 기반으로, PLIB Part 42에서 제시하는 패밀리 조직 방법론을 적용하였다. 분류된 구성요소와 모듈에 대한 정보의 쉬운 검색 및 접근을 위하여 이름, 동의어, 정의 등과 같은 속성을 정의하였다. 또한 모듈의 형상표현이 가능하도록 속성을 정의하여, 파트라이브러리 시스템의 구성요소인 라이브러리 컨텐츠에 저장된 모듈라이브러리의 사용성을 용이하게 하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.11a
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• pp.189-192
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• 2007

본 논문에서는 대부분의 공동 영역에서 사용하는 상부에 설치된 감시카메라에서 사람의 얼굴 영역을 검출할 수 있는 방법을 제안한다. 본 제안 기법에서는 입력 영상에 대한 원근 변환을 통하여 영상 보정을 처리하고 보정된 영상에서 얼굴 감지 알고리즘을 적용함으로써 기존의 방법에서 검출할 수 없는 고개를 숙인 얼굴에서도 얼굴을 검출할 수 있도록 하였다. 실험결과 고개를 숙인 얼굴이나 상부의 카메라에 의해 촬영된 영상에서 기존의 방법에 비해 보다 안정적으로 얼굴 영역을 검출할 수 있었다.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.30 no.1
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• pp.24-32
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• 2021

Dental implant have been in use for a long time to restore at missing tooth. But, To place dental implant at good position very is difficult. Improperly positioned dental implants make some problems to have a good function of dental implant. so, To place dental implant at accurate position is the most important step throughout the whole process. Digital guided system of dental implant is very useful to have a accurate position of dental implant and it makes upper restoration more esthetic and funcional.

• Journal of the Society of Naval Architects of Korea
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• v.33 no.2
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• pp.119-126
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• 1996

A hydraulic type active control system has been developed for the purpose of vibration suppression of ship superstructrures. The active mass of the developed system weighs about three tons and is designed to have ${\pm}5mm$ stroke below 10Hz. Thus maximum control force of the system is about 60kN. Performance test of the developed system has been carried out on a 4,400TEU contrainer carrier built in Samsung Heavy Industry Co., LTD. Through the exciter tests, it has been confirmed that the vibration levels of the superstructure can be reduced to about 20% of the uncontrolled levels near resonant frequency.