• 한국건설관리학회논문집
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• 제14권5호
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• pp.153-163
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• 2013

건축물이 고층화, 대형화 될수록 수직 양중 계획 및 운영에 관한 중요성이 부각되고 있다. 이에 프로젝트 초기 단계에 실제 모델과 유사한 건설용 리프트 양중계획을 수립하려는 노력이 계속되고 있지만 프로젝트 착수 후 리프트 운행을 컨트롤 할 수 있는 시스템은 부재한 실정이다. 따라서 본 논문에서는 건설용 리프트 운영 효율증대를 위하여 센서를 사용한 리프트 운행 정보를 수집하고 실시간 분석이 가능한 건설용 리프트 최적화 운행 시스템 개발을 실시 및 검증 단계를 수행하여, 양중 효율의 지표가 되는 사용자 대기 시간의 단축을 도모하고 향후 무인 스마트 리프트의 초석이 되는 시스템을 제시하고자 한다.

• KSBB Journal
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• 제21권2호
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• pp.103-109
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• 2006

H. erinaceum의 기능성 소재화 연구의 일환으로, 지금까지 체계적으로 연구된 바 없는 H. erinaceum의 액체배양을 시도하고. 이 버섯의 서로 다른 생물반응기하의 액체배양 특성을 규명하고 대량생산을 검토하였다. 5 L 용량의 jar fermenter와 air-lift fermenter에서의 액체배양의 비교실험을 통해 air-lift fermenter의 사용이 종균 배양에 적합한 것으로 나타났으며, 형태 분석을 통해 적정 크기($2{\sim}4mm$)의 pellet 형태의 유지가 대량 생산의 중요인자인 것을 규명하였다. Air-lift fermenter 하의 배양을 종균으로 하고, 적정 크기의 pellet을 유지하는 500 L까지의 jar fermenter를 사용한 회분 배양의 scale-up 실험결과, 30 및 500 L에서의 교반 및 통기속도는 각각 200 rpm, 1 vvm 및 150 rpm, 1 vvm이었다. 이 조건하에서 배양의 전 기간 중 적정 pellet을 유지하였으며, 최대 균사체량은 약 $13{\sim}14g/L$이었다.

• Wind and Structures
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• 제9권2호
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• pp.109-124
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• 2006

This paper describes the characteristics of the fluctuating lift forces when a circular cylinder vibrates in the cross-flow direction. The response characteristics on elastically supported the circular cylinder was first examined by a free-vibration test. Next, flow-induced vibrations obtained by the free-vibration test were reproduced by a forced-vibration test, and then the characteristics of the fluctuating lift forces, the work done by the fluctuating lift, the behavior of the rolling-up of the separated shear layers were investigated on the basis of the visualized flow patterns. The main findings were that (i) the fluctuating lift forces become considerably large than those of a stationary circular cylinder, (ii) negative pressure generates on the surface of the circular cylinder when the rolling-up of separated shear layer begins, (iii) the phase between the fluctuating lift force and the cylinder displacement changes abruptly as the reduced velocity $U_r$ increases, and (iv) whether the generating cross-flow vibration becomes divergent or convergent can be described based on the work done by the fluctuating lift force. Furthermore, it was found that the generation of cross-flow vibration can be perfectly suppressed when the small tripping rods are installed on the surface of the circular cylinder.

• Journal of Advanced Marine Engineering and Technology
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• 제36권1호
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• pp.101-108
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• 2012

본 연구 결과는 해상풍력발전시스템 타워 내부에 설치하는 서비스리프트의 설계 및 구조해석에 대한 내용이며, 공학적 설계법 및 수치해석에 의한 구조해석을 통하여 서비스리프트의 안정성 및 신뢰성을 확인하였다. 설계의 주된 내용은 설계 허용한계 이내에서 만족스러운 성능으로 지상으로부터 타워상부의 해상풍력터빈 너셀까지 작업자와 수리보수용 장비를 안전하게 수송할 수 있는 충분한 능력을 확보하는 것이다. 구조해석을 통하여 서비스리프트 캐빈 및 안전장치의 총변형량과 등가응력에 대해서 검토하여 설계 시 적용한 안전율의 타당성을 검토하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.330-333
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• 2003

In this thesis. the application of the synchronizing control of the intelligent indoor lift system is showed. The separate axes of the indoor lift system are driven independently. PID controller, synchronous flexible logic compensating method and tilt sensor are applied to enhance the performance of the intelligent indoor lift system. the tilt sensor senses the horizontal error of the whole system. PID controller and synchronous flexible logic are used to compensate the synchronous errors of both the separate axes and whole system to be zero. Namely, using not the hardware coupling but the software algorithm. the indoor life system is operated without the error. Before applying the real system, the simulation using matlab testifies the possibility of the lift system. And the realization of the system is demonstrated with two DC servo motors. In the experiment test, flexible logic to compensate the synchronous error is chosen by the comparative method. the indoor lift system has to be considered the loading factor as the disturbance. Because the intelligent indoor lift system is developed to support the patients who don't change for themselves to move. finally, the system which considers the weight of the patient as the disturbance can carry the patients safely without synchronous and position error.

• Archives of Plastic Surgery
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• 제33권4호
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• pp.525-529
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• 2006

Purpose: Facial nerve injury is a rare but feared complication of face lift. Uncertainty as to the depth and vulnerability of the facial nerve in face lift dissection causes some surgeon, particularly novices, to dissect slowly. Excessively thin flaps can be made because of fear of nerve injury, contributing to skin slough. Methods: From September 1998 to February 2003, the authors operated on 34 aging face patients using classical face-lift. We had analysed about quantity of skin removal and degree of elevated flap. The authors have found quantity of skin removal was 1.5-2.0 cm, degree of elevated flap was 40-45 degree on average. Results: The authors performed preauricular pre-excision face-lift technique on 12 aging face patients from July 2003 to Feburary 2005 based on experienced surgery. This technique reduced fear of dissecting skin flap necrosis and facial nerve injury because of firmly attached pre-auricular skin removed in advance. Conclusions: We easily dissected SMAS without visual field disturbance, nerve damage and reduced operation time and bleeding loss compared to classical face-lift.

• 한국전산유체공학회지
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• 제17권3호
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• pp.18-24
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• 2012

The aerodynamic performance of the pantograph on a high speed train was compared for different pantograph covers which are designed to block the aero-acoustic noise from the pantograph. For the study, two types of cover are designed: wedge and cone types. The lift force of pantograph with cover was compared with the force of pantograph only. The comparison clarified that the cone type cover increases the sideslip angle of the flow and decreases the lift force considerably. However, the wedge type cover changes the flow direction upward and increases the lift force of the pan head. This increment of lift force compensates the decrement of lift force caused by the blocking of the flow into the pantograph lower frame due to cover. Therefore, in case of the wedge type cover, the overall lift force changes slightly compared with the cone type cover.

• 한국산업융합학회 논문집
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• 제22권6호
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• pp.711-719
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• 2019

At present, wind power is the fastest growing technology in the world. The domestic market depends heavily on imports for wind tower lift. so it manage through the overseas maker. The lift manufacture, establishment and maintenance utility is increasing, localization development of one wind tower lift is necessary with domestic fundamental base technique. In this paper, we will study the components necessary for the development of onshore offshore wind tower elevators, which are currently dependent on total imports, in line with the high growth of the wind market and the enlargement of the wind power generators. First of all, endless winders and cabins, which are the core components of the offshore wind tower lift, were examined for the components that affect the structural safety. Structural analysis was performed on Sheave, which is responsible for most of the lift lifting loads, and Block Stop, a safety device that prevents the cabin from falling in an emergency. The structural suitability was evaluated by comparing with the safety factor. In addition, the on-board control panel combines the control panel of the elevator and the drive motor driving the endless winder for efficient control of the offshore wind tower lift. The addition of features improves ride comfort at departure.

• 한국항공우주학회지
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• 제49권10호
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• pp.859-870
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• 2021

항우연은 eVTOL 항공기의 개념설계 및 기본설계를 위한 설계프레임워크를 개발하고 있다. 오픈소스 SUAVE 패키지를 활용하여 틸트 프롭 및 리프트 프롭을 갖는 Lift-Tilt 개념의 전기수직이착륙기에 대한 저충실도 임무분석도구를 개발하였다. 그 개발을 위하여 SUAVE의 프롭성능해석 기능을 검토하였다. 매 임무 세그먼트에서 트림해를 자동적으로 찾기 위해 병렬처리 및 실험계획법을 통한 전역최적화 기법을 적용한 알고리듬을 구현하였다. 동 도구를 사용하여 1인승급 전기추진 수직이착륙 유무인 겸용 개인항공기(OPPAV)의 임무분석을 수행하고 동 항공기의 기본설계데이터와 비교하였다.

• Wind and Structures
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• 제35권3호
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• pp.157-175
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• 2022

This paper highlights the minimization of drag and lift coefficient of different types both side setback tall buildings by the multi-objective optimization technique. The present study employed 48 number both-side setback models for simulation purposes. This study adopted three variables to find the two objective functions. Setback height and setback distances from the top of building models are considered variables. The setback distances are considered between 10-40% and setback heights are within 6-72% from the top of the models. Another variable is wind angles, which are considered from 0° to 90° at 15° intervals according to the symmetry of the building models. Drag and lift coefficients according to the different wind angles are employed as the objective functions. Therefore 336 number population data are used for each objective function. Optimum models are compared with computational simulation and found good agreements of drag and lift coefficient. The design wind angle variation of the optimum models is considered for drag and lift study on the main square model. The drag and lift data of the square model are compared with the optimum models and found the optimized models are minimizing the 45-65% drag and 25-60% lift compared to the initial square model.