• 한국항공우주학회지
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• 제40권7호
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• pp.590-600
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• 2012

본 논문에서는 태양전지나 연료전지와 같은 전기 에너지원을 사용하는 항공기에 적용할 수 있는 일반화된 사이징 방법에 대해 연구를 수행하였다. 다중 추진 시스템이나 에너지원이 사용되는 경우를 고려하여 다중 동력경로를 모델링하였고 소모성 에너지와 비소모성 에너지 중량을 각 임무 단계의 중량변화 계산에 반영하였다. 구속조건의 분석에서 기존의 추력 대 중량비 대신 동력 대 중량비를 선택하여 동력 균형 및 에너지 균형의 사이징 과정에 사용하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 춘계학술대회 논문집
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• pp.588-593
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• 2011

The Main design parameters of ship HVAC systems are pressure drop and noise analysis of ducts. The Noise prediction for HVAC(Heating, Ventilating and Air Conditioning) systems are normally performed by empirical method suggested by NEBB(National Environmental Balancing Bureau, 1994), but NEBB's method is not suitable for the ship HVAC systems. In this paper, numerical analysis methods are used to develop a noise prediction method for the ship HVAC systems, especially for large ducts. To develop regression formula of attenuation of sound pressure level in large duct, Boundary Element Method(BEM) is used. Using dynamic loss coefficient which is suggested by ASHRAE fitting data base and numerical methods of HVAC noise analysis, integrated HVAC noise analysis of Program is developed. The developed program can present pressure drop and noise analysis of the ship HVAC systems. To verify the accuracy and convenience of the developed program, prediction of HVAC system for Semi-Submersible Drilling RIG is carried out and the results are compared with measurement of noise level during sea trial.

• 동의생리병리학회지
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• 제22권2호
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• pp.459-463
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• 2008

Postural balance of temporomandibular joint (TMJ) reflects the neuromuscular balance. TMJ posture treatment for meridian yinyang balance has been asserted to have an impact upon cervical spine alignment with an episodic good clinical result for refractory torticollis cases. A retrospective study with one-group pretest-posttest design was conducted to review cervical spine imaging data and clinical symptom changes in cervical dystonia cases to explore the effect of TMJ balance treatment. Review of clinical symptoms and cervical spine imaging data including computed tomography and simple x-ray of 9 cervical dystonia cases revealed significant improvement of cervical spine alignment and clinical symptoms. Improvement of cervical spine alignment may be an underlying mechanism of TMJ balance treatment, as a way of balancing the whole-body meridian system.

• 한국광학회지
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• 제10권2호
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• pp.120-127
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• 1999

Head-Up Display(HUP)에 사용되는 홀로그래픽 광결합기의 회절 효율 및 결상 특성을 분석하고 제작하였다. Kogelnik의 결합파이론을 통해 반사형 체적 홀로그램에 대한 각도 및 분광 대역 특성을 수치계산하고 홀로그래픽 광학소자에서의 파장 변화에 의한 색수차의 최소화 방법을 HUD의 재생각 및 초점거리 보정에 응용하였다. 또한 자동차에 사용되는 형태로 등각형(conformal type)과 비등각형(non-conformal type)의 홀로그래픽 광결합기를 비교하고 대역 특성을 실험적으로 분석하였다. 실제적으로 등각형 보다 넓은 각도 대역폭을 보이며 광학적 배율(optical power)을 지니는 홀로그래픽 광결합기를 설계, 제작하였다.

• 동력기계공학회지
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• 제12권1호
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• pp.41-46
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• 2008

The primary objective of this study is to truly understand exciting forces of the in-line 4 cylinders engine. Exciting forces of the engine apply a source of the vehicle NVH(Noise, Vibration, Harshness). To understand exciting forces, first was governed theoretical equations for single cylinder engine. And this theoretical equations was programming using MATLAB software. To compare theoretical analysis value, was applied MSC.ADAMS software. To determined the specification of engine(2,000cc, in-line 4) was applied ADAMS/Engine module. And this specification for engine was applied ADAMS/View and MATLAB software. The geometry model for ADAMS/View analysis was produced by the 3-D design modeling software. After imported 3-D model, each rigid body was jointed suitable. Under idle speed for engine, was analysed. The results of analysis are fairly well agreed with those of three analysis method. Using MATLAB software proposed in this study, engine exciting fores can be predicted. Also using ADAMS/Engine module and ADAMS/View software, engine exciting forces can be predicted.

• 한국컴퓨터정보학회논문지
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• 제17권9호
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• pp.1-8
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• 2012

클라우드 컴퓨팅은 컴퓨팅 자원의 효율적 사용과 수월한 접근이라는 관점에서 사용자 및 서비스 제공자에게 모두 각광받고 있다. 한편, 클라우드 컴퓨팅의 자원은 이질적 환경으로 구성되는 경우가 많고 사용자의 워크플로우는 다양한 특성을 가진다. 따라서 본 연구의 목적은 이러한 환경에서 워크플로우의 응답성 요구에 따라 우선순위를 부여하고 워크플로우를 구성하는 태스크의 자원 할당시 응답성, 비용, 그리고 부하 균등으로 구성되는 QoS 메트릭을 구성하여 효율적으로 워크플로우를 스케줄링하는 것이다. 제안기법의 성능 평가를 위해 다양한 실험을 수행한 결과 응답성과 가용성이 향상되었음을 확인할 수 있었다.

• 제어로봇시스템학회논문지
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• 제20권10호
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• pp.1063-1066
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• 2014

The humanoid robot, DRC-HUBO is developed from the KHR (KAIST Humanoid Robot) series to meet the requirements of the DARPA Robotics Challenge. DARPA Robotics Challenge was a competition to develop semi-autonomous humanoid robot so that dispatched in dangerous environments in place of humans like the Fukushima nuclear accident. In this paper, we introduce DRCH-UBO briefly and a methodology to remove debris blocking an entryway. The methodology includes inverse kinematics for DRC-HUBO and stabilization controller based on ZMP. Proposed inverse kinematics is robust, and pelvis-related tasks improve the manipulability and workspace of the arms. The controller improves the damping characteristic of the system and mitigates the instability during removal of debris. For given position and orientation of the debris, DRC-HUBO generates motion to reach the debris and lift up while stabilizing itself. Many experimental results verify our proposed methodology.

• 대한임베디드공학회논문지
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• 제10권5호
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• pp.281-296
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• 2015

This paper describes a novel disaster evacuation system using embedded systems such as smart devices for crisis and emergency management. In indoor environments deployed with the Bluetooth Low Energy(BLE) beacons, smart devices detect their indoor positions from beacon messages and interact with Map Server(MS) and Route Server(RS) in the Internet over the LTE and/or Wi-Fi functions. The MS and RS generate an optimal path to the nearest emergency exit based on a novel graph generation method for less route computation, called the Disaster Evacuation Graph(DEG), for each smart device. The DEG also enables efficient processing of some constraints in the computation of route, such as load balancing in situation of different capacities of paths or exits. All data interfaces among three system components, the MS, RS, smart devices, have been defined for modular implementation of our disaster evacuation system. Our experimental system has been deployed and tested in our building thoroughly and gives a good evidence that the modular design of the system and a novel approach to compute emergency route based on the DEG is competitive and viable.

• 한국산학기술학회논문지
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• 제9권6호
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• pp.1529-1534
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• 2008

최근, 교반기는 화학물질의 교반 및 탈포를 위해 디스플레이, 반도체 업체에서 광범위하게 사용되고 있다. 교반기는 일반적으로 축, 교반조, 감속기어 및 구동 모터로 구성되어 있다. 교반기 설계시의 주요 사항은 회전시의 동적 특성을 평가하는 것이다. 회전시의 동적특성은 진동, 소음 및 열방출로 나타난다. 본 논문은 고속 교반기의 동적 특성을 실험적으로 규명하였다. 진동을 유발하는 주 인자는 회전체의 불균형에 기인한 것임을 알 수 있었으며, 교반 용기 부위의 온도가 전체온도에서 상대적으로 제일 높음을 알 수 있었다.

• Journal of Electrical Engineering and Technology
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• 제9권2호
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• pp.576-588
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• 2014

The superiority of CMI (Cascaded Multilevel Inverter) is unparalleled in high power and high voltage STATCOM (Static Synchronous Compensator). However, the parameters and operating conditions of each individual power unit composing the cascaded STATCOM differ from unit to unit, causing unit voltage disequilibrium on the DC side. This phenomenon seriously impairs the operation performance of STATCOM, and thus maintaining the DC voltage balance and stability becomes critical for cascaded STATCOM. This paper analyzes the case of voltage disequilibrium, combines the operation characteristics of the cascaded STATCOM, and proposes a new DC voltage control scheme with the advantages of good control performance and stability. This hierarchical control method uses software to achieve the total active power control and also uses chopper controllers to enable that the imbalance power can flow among the capacitors in order to keep DC capacitor voltages balance. The operating principle of the chopper controllers is analyzed and the implementation is presented. The major advantages of the proposed control strategy are that the number of PI regulators has been decreased remarkably and accordingly the blindness of system design and debugging also reduces obviously. The simulation reveals that the proposed control scheme can achieve the satisfactory control goals.