• 제목/요약/키워드: lift

검색결과 2,952건 처리시간 0.038초

Total Facelift: Forehead Lift, Midface Lift, and Neck Lift

  • Park, Dong Man
    • Archives of Plastic Surgery
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    • 제42권2호
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    • pp.111-125
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    • 2015
  • Patients with thick skin mainly exhibit the aging processes of sagging, whereas patients with thin skin develop wrinkles or volume loss. Asian skin is usually thicker than that of Westerners; and thus, the sagging of skin due to aging, rather than wrinkling, is the chief problem to be addressed in Asians. Asian skin is also relatively large in area and thick, implying that the weight of tissue to be lifted is considerably heavier. These factors account for the difficulties in performing a facelift in Asians. Facelifts can be divided into forehead lift, midface lift, and lower face lift. These can be performed individually or with 2-3 procedures combined.

Aerodynamic Performance Improvement by Divergent Trailing Edge Modification to a Supercritical Airfoil

  • Yoo, Neung-Soo
    • Journal of Mechanical Science and Technology
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    • 제15권10호
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    • pp.1434-1441
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    • 2001
  • A computational study has been performed to determine the effects of divergent trailing edge (DTE) modification to a supercritical airfoil in transonic flow field. For this, the computational result with the original DLBA 186 supercritical airfoil was compared to that of the modified DLBA 283. A wavier-Stokes code, Fluent 5. 1, was used with Spalart-Allmaras's one-equation turbulence model. Results in this study showed that the reduction in drag due to the DTE modification is associated with weakened shock and delayed shock appearance. The decrease in drag due to the DTE modification is greater than the increase in base drag. The effect of the recirculating flow region on lift increase was also observed. An airfoil with DTE modification achieved the same lift coefficient at a lower angle of attack while giving a lower drag coefficient. Thus, the lift-to-drag ratio increases in transonic flow conditions compared to the original airfoil. The lift coefficient increases considerably whereas the lift slope increases just a little due to DTE modification.

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The Effects of Lift-Off from Wall Thinning Signal in Pulsed Eddy Current Testing

  • Park, Duck-Gun;Angani, C.S.;Kishore, M.B.;Kim, C.G.;Lee, D.H.
    • Journal of Magnetics
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    • 제17권4호
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    • pp.298-301
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    • 2012
  • In order to know the effect of surface irregularity in the detection of local wall thinning of pipeline using pulsed eddy current (PEC), the lift-off effects on PEC signal have been investigated. Three kinds of parameters in the PEC signal, which is "peak amplitude", "time to peak amplitude" and "time to zero crossing" are analyzed to separate the lift-off effects in the PEC signal. The distance from sensor to the bottom of sample which is the total thickness of combined insulator and sample is kept constant. The magnitude of the differential peak amplitude is increased with increasing sample thickness, the time to peak amplitude is increased with increasing the sample thickness. To determine the effect of lift-off, a number of balanced transient responses combining wall thinning locations and lift-off distances were plotted.

초고층 창호공사 조기착공을 위한 ACS-Lift Car 연계 시스템 기초연구 (The Study on Integrated ACS and Lift Car System for Early Beginning of Windows Work in Tall Building Construction)

  • 이동윤;임현수;조훈희;강경인
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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    • pp.72-73
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    • 2014
  • Recently the concurrent construction method of framework and windows work has been applied for early beginning of exterior finishing works in tall building construction. However, the conventional method makes difficulties in auto-climbing of gang-form and climbing work of lift car since the removal of ACS(auto climbing system) should be preceded for operation of lift car up to the top floor. This study propose a concept model of integrated ACS and lift car system to resolve these problems and begin windows works early in tall building construction.

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LIFT 방법에 의한 전도성 미세 패터닝 공정 연구 (Micro patterning of conductor line by laser induced forward transfer(LIFT))

  • 이제훈;한유희
    • 한국레이저가공학회지
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    • 제2권3호
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    • pp.52-61
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    • 1999
  • The laser induced forward transfer(LIFT) technique employs a pulsed laser to transfer parts of a thin metal film from an optically transparent target onto an arbitrary substrate in close proximity to the metal film on the target. In this work, a two-step method, the combination of LIFT process, in which a Au film deposited on the $Al_2$O$_3$ substrate by Nd:YAG laser and subsequent Au electroless metal plating on the by LIFT process generated Au seed, was presented. The influence of laser parameters, wavelength, laser power, film thickness and overlap ratio of pulse tracks, on the shapes of deposit and conductor line after electroless plating is experimentally studied. As a results, the threshold power densities for ablation, deposition and metallization were determined and comparison of threshold value between the wave length 1064nm and the second harmonic generated 532nm. In odor to determine a possible application in the electronic industry, a smallest conduct spot size, line width and isolated line space were generated.

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경비행기의 최대양력계수 추정에 대한 연구 (A Study on the Estimations of Maximum Lift Coefficients of a Light Airplane)

  • 이정훈;류시융
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.762-767
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    • 2008
  • Estimated values for maximum lift coefficients of a light airplane, ChanGong-91, derived from an analytical method using a test database, a computational fluid dynamic method, a wind tunnel test, and a flight test are compared. The DATCOM method and VSAERO code are applied as the analytical method and the computational fluid dynamic method, respectively, in order to estimate the maximum lift coefficients of a light airplane. The wind tunnel test is conducted using a 1/14.5 scaled model installed in a closed circuit type wind tunnel. For the flight test approach, the wings-level power-off stall tests are performed to obtain the maximum lift coefficients. As a point of reference for the flight test results of the maximum lift coefficients, the differences of both estimates derived from the DATCOM method and the wind tunnel test data are smaller than those derived from VSAERO.

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공기 양정(air lift) 펌프를 응용한 슬러지 배출장치에 대한 연구 (Application of Air Lift Pump for Sludge Discharger)

  • 안갑환;박영식
    • 한국환경과학회지
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    • 제13권10호
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    • pp.929-938
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    • 2004
  • Sludge discharger applied the principle of the air lift pump was investigated experimentally for the different design( diameter of discharge pipe, diameter and height of the inside and outside wall) and operating parameters(air flow rate, water level). And it was conducted that performance comparison about sludge discharger and conventional air lift pump. The result indicated that discharged liquid were increased with the increase of air flow rate and water level and decrease distance between inside and outside wall. The discharge pressure was increased with an increase of air flow rate and a decrease of the diameter of the discharge pipe, for both the sludge discharger and the airlift pump. The discharge pressures of the sludge discharger were 3-6 times higher than those of the air lift pump.

Analysis and Optimization of Permanent Magnet Dimensions in Electrodynamic Suspension Systems

  • Hasanzadeh, Saeed;Rezaei, Hossein;Qiyassi, Ehsan
    • Journal of Electrical Engineering and Technology
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    • 제13권1호
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    • pp.307-314
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    • 2018
  • In this paper, analytical modeling of lift and drag forces in permanent magnet electrodynamic suspension systems (PM EDSs) are presented. After studying the impacts of PM dimensions on the permanent magnetic field and developed lift force, it is indicated that there is an optimum PM length in a specified thickness for a maximum lift force. Therefore, the optimum PM length for achieving maximum lift force is obtained. Afterward, an objective design optimization is proposed to increase the lift force and to decrease the material cost of the system by using Genetic Algorithm. The results confirm that the required values of the lift force can be achieved; while, reducing the system material cost. Finite Element Analysis (FEA) and experimental tests are carried out to evaluate the effectiveness of the PM EDS system model and the proposed optimization method. Finally, a number of design guidelines are extracted.

정밀 위치 제어를 위해 MR 밸브 시스템을 활용한 차량 유압 리프트에 대한 수치해석적 고찰 (A Numerical Study of New Vehicle Hydraulic Lift Activation by a Magneto-rheological Valve System for Precise Position Control)

  • 이태훈;박진하;최승복;신철수;최지영
    • 한국소음진동공학회논문집
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    • 제27권1호
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    • pp.28-35
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    • 2017
  • 최근 기존의 유압 차량 리프트는 높이제어의 어려움으로 인해 기술개발의 한계에 직면하였다. 휠 얼라이먼트나 차량의 하중 분포에 따른 미세한 불규칙적인 변형을 보상하기 위해서는 매우 정밀한 위치 제어성이 요구되고 있다. 이 연구에서는 이러한 기존 리프트 시스템의 한계를 해결하고자 매우 정교한 압력강하를 이끌어낼 수 있는 MR 밸브 시스템을 활용하여 새로운 차량 리프트를 제안하고 이에 대한 분석을 진행한다. 우선적으로 MR 밸브의 요구되는 성능을 파악하기 위해 유압 리프트의 운동방정식을 설립하고, 요구되는 압력강하를 얻기 위해 MR 밸브를 설계한다. 또한 정밀한 위치 제어 성능을 얻기 위해 PID 제어기를 설립하고, 시뮬레이션을 통해 제안된 시스템의 제어성을 검증한다.

이동 통신 중계기 설치를 통한 승강기 시스템의 전자파 환경 개선 (Improvement of Electromagnetic Environment Effects in aLift System by Installing a Mobile-Communication Repeater)

  • 임병철;정기범;정연춘
    • 한국전자파학회논문지
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    • 제22권11호
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    • pp.1125-1132
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    • 2011
  • 본 연구의 목적은 전자파 적합성을 고려하여 승강기 시스템 내에 중계기 안테나를 설치하는 방안을 제안하는 것이다. 승강로에 중계기 안테나를 설치하는 경우(Solution 1)와 승강기 내부에 중계기 안테나를 설치하는 경우 (Solution 2)의 2가지 solutions을 검토하였으며, Solution 2가 Solution 1보다 효과적임을 확인하였다. 또한, 승강기에 대한 전자파 내성 기술 기준과 20 dB의 안전 마진을 고려하여 중계기 안테나의 출력(EIRP)을 -5 dBm으로 제한할 것을 제안하였으며, 이러한 출력은 이동 통신 시스템의 정밀 전력 제어 메커니즘에 따라 최적의 안정된 전자파 환경을 제공함을 확인하였다. 이러한 접근은 무선을 활용하여 오히려 전자파 환경을 개선할 수 있음을 보여준 본 연구가 Green ICT의 중요한 사례가 될 수 있다.