• 제목/요약/키워드: changing shape

검색결과 915건 처리시간 0.026초

코일형상 변화에 의한 광픽업 액츄에이터의 동특성 개선 (Improvement of Dynamic Characteristics for Optical Pickup Actuator by Changing Coil Shape)

  • 김충;송명규;이동주;박노철;박영필
    • 정보저장시스템학회:학술대회논문집
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    • 정보저장시스템학회 2005년도 추계학술대회 논문집
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    • pp.69-70
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    • 2005
  • In this paper, slim type optical pickup actuator was fabricated and its FE model was tuned to experimental results through precise coil models. In order to widen its control bandwidth, stiffness of moving parts was increased by changing shape of coil section. Finally, we checked that flexible mode frequency and gain margin was increased.

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전기하전식 세정집진장치 개발에 관한 기초 연구 (A Basic Study on Developing an Electrocharged Scrubber)

  • 김종호
    • 한국대기환경학회지
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    • 제15권1호
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    • pp.33-39
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    • 1999
  • This study has been performed to develop an efficient electrocharged scrubber. To improve collection efficiency of the scrubber, electric-charger was installed at the forefront of the packed crossflow scrubbers, and an experiment of changing discharge electrode shape and fluctuating electric field strength was undertaken. After using a light-oil boiler for generation of particles in the about 80% weight of submicron size particles was exhausted. Collection characteristics of the electrocharged scrubber were similar to those of two-stage electrostatic precipitator. In this study the collection efficiency of submicron size particles has been much improved, compared with the previous ones. In an experiment of changing discharge electrode and electric field strength, a needle-spike shape wire electrode showed a higher collection efficiency than round shape wire. The collection efficiency becomes increased with an increase of electric field strength.

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극간절연회복성능 향상을 위한 초고압GCB의 노즐형상설계 (Design of Nozzle Shape for UHV GCB to Improve the Dielectric Recovery Characteristics between Electrodes)

  • 송기동;박경엽;신영준;권기영;송원표
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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    • pp.479-481
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    • 1995
  • This paper presents a method witch tan improve the dielectric recovery characteristics of UHV class gas circuit breakers by changing the nozzle shape. To calculate the dielectric recovery voltage between electrodes, the flow field and electric field analysis in a 362kV model interrupter has been performed with the commercial programs, RAMPANT and FLUX2D, respectively. As a result, we found that the nozzle shape affects the characteristics of dielectric recovery between electrodes and obtained great improvement of it by the changing the downstream nozzle shape.

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하복의 체표변화에 따른 동작적합성에 관한 연구 -하복동작 및 체형을 중심으로- (A Study on the Movement-Fitness according to the Surface changing of Lower-Limb -On the Movements and Shapes of Lower-limb-)

  • 박영득;서영숙
    • 한국의류학회지
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    • 제20권2호
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    • pp.257-269
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    • 1996
  • The puropose of this study was to investigate the movement-fitness according to the surface changing of lower limb The experimental items were divided into the lower limb movements (5) and body-shapes (7). This study was done by the expansion and contraction rate consideration of length, girth Also, the lower half of body shape-change on the movements and body-shapes by flat shell was done simultaneously. The summarized findings resulted from experiments and investigation are suggested as follows; First, when commpared the expansion and contraction rate of the length and girth items, the expansion rate of the back crotch length (14~20%), hip girth (10~ 21%) and knee girth (6.2~18.5%) in rabbit leap movement was the most notable among all variables considered in this experimentation. On the others hand, the front croth length (-22~-52%) contracted remarkably. And big-thigh type was the most notable on the body-shape comparision. Second, in comparision of the expansion and contraction rate of the area on the blocks, the expansion of the hip (50~200%) and knee (51~74%) block was the most remarkable. Especially, in the sit on knees movement of the hip-down type expanded 209.4%. Third, in comparision of the lower half of body shape-change, on the movements and body- shapes by the flat shell, under the influence of knee-joint and hip-joint the shape-changs of the hip and knee block was the most notable. But the shape-change of the waist, abdomen, calf, and ankle was feeble.

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3 Stage 2 Switch Application for Transcranial Magnetic Stimulation

  • Ha, Dong-Ho;Kim, Whi-Young;Choi, Sun-Seob
    • Journal of Magnetics
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    • 제16권3호
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    • pp.234-239
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    • 2011
  • Transcranial magnetic stimulation utilizes the method of controlling applied time and changing pulse by output pulse through power density control for diagnosis purposes. Transcranial magnetic stimulation can also be used in cases where diagnosis and treatment are difficult since output pulse shape can be changed. As intensity, pulse range, and pulse shape of the stimulation pulse must be changed according to lesion, the existing sine wave-shaped stimulation treatment pulse poses limitations in achieving various treatments and diagnosis. This study actualized a new method of transcranial magnetic stimulation that applies a 3 Stage 2 Switch( power semiconductor 2EA) for controlling pulse repetition rate by achieving numerous switching control of stimulation coil. Intensity, pulse range, and pulse shape of output can be freely changed to transform various treatment pulses in order to overcome limitations in stimulation treatment presented by the previous sine wave pulse shape. The method of freely changing pulse range by using 3 Stage 2 Switch discharge method is proposed. Pulse shape, composed of various pulse ranges, was created by grafting PFN (Pulsed Forming Network) through AVR AT80S8535 one-chip microprocessor technology, and application in transcranial magnetic stimulation was achieved to study the output characteristics of stimulation treatment pulse according to delaying time of the trigger signal applied in section switch.

임의의 형태를 갖는 흠을 이용한 표면형상변형을 통한 동특성 변경 (Structural Dynamics Modification Using Surface Grooving Technique)

  • 박미유;박영진;박윤식
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2004년도 춘계학술대회논문집
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    • pp.859-863
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    • 2004
  • Structural Dynamics Modification is very effective technique to improve structure's dynamic characteristics by adding or removing auxiliary structures, changing material property, changing shape of structure. In this research, using the surface grooving technique, shape of base structure was changed to improve its first natural frequency. Utilizing the result of sensitivity analysis, groove shape was formed gathering the many small embossing elements. For this process, Sensitivity Criterion Factor was introduced. To reduce its amount of calculation, the range of target area was restricted to their neighboring area and that result was very successful.

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그루브를 이용한 표면형상변형 동특성 변경법 :HDD 커버에 대한 적용 (Structural Dynamics Modification Using Surface Grooving Technique : Application to the HDD Cover model)

  • 박미유;박영진;박윤식
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2004년도 추계학술대회논문집
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    • pp.826-829
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    • 2004
  • Structural Dynamics Modification is very effective technique to improve structure's dynamic characteristics by adding or removing auxiliary structures, changing material property, changing shape of structure. In this research, using the surface grooving technique, shape of base structure was changed to improve its first natural frequency. Utilizing the result of frequency variation analysis, groove shape was formed gathering the many small embossing elements. For this process, Criterion Factor was introduced. To reduce its amount of calculation, the range of target area was restricted to their neighboring area and initial grooving point was selected using high-strain energy. This surface grooving technique was successfully applied to the HDD cover model.

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신간선 전두부 디자인의 형상 변천 (The Changes of Shinkansen Vehicles' Nose Shape)

  • 김광명;한석우
    • 한국철도학회논문집
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    • 제10권2호
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    • pp.124-130
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    • 2007
  • The emphasis of this paper is to find out the changes in length of nose in line with speed improvement and changes of the tendency in the shape of the nose in line with time series based on the Shinkansen vehicle. The length of the nose on the lines of high speed tends to get longer, however there is no proportion between the speed and the nose according to optimal design that was designed to reduce micro-pressure wave and air resistance. The Shinkansen vehicles, according to the shape, can be classified in to an Advanced Paraboloid shape, a Sharp-nosed shape, a Flat-nosed shape and an Organic Double-edged shape and is gradually changing in the trend of diversity and distinction. Hereafter, the design of the nose will be developed better into the design that will comprehend identity of manufacturer, region and culture on the basis of optimized aerodynamic shape.

Study of ion beam shaping of an anode-type ion source coupled with a Whenelt mask

  • Huh, Yunsung;Hwang, Yunseok;Kim, Jeha
    • Applied Science and Convergence Technology
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    • 제27권4호
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    • pp.70-74
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    • 2018
  • We fabricated an anode-type ion source driven by a charge repulsion mechanism and investigated its beam shape controlled by a Whenelt mask integrated at the front face of the source. The ion beam shape was observed to vary by changing the geometry of the Whenelt mask. As the angle of inclination of the Whenelt mask was varied from $40^{\circ}$ to $60^{\circ}$, the etched area at a thin film was reduced from 20 mm to 7.5 mm at the working distance of 286 mm, and the light transmittance through the etched surface was increased from 78% to 80%, respectively. In addition, for the step height difference, ${\Delta}$ between the inner mask and the outer mask of ${\Delta}=0$, -1 mm, and +1 mm, we observed the ion beam shape was formed to be collimated, diverged, and focused, respectively. The focal length of the focused beam was 269 mm. We approved experimentally a simple way of controlling the electric field of the ion beam by changing the geometry of the Whenelt mask such that the initial direction of the ion beam in the plasma region was manipulated effectively.