• Title/Summary/Keyword: gravity center

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The effect of Anticipatory Postural Adjustment on Balance Performance in Postural Disturbance (자세동요에 있어 선행적 자세적응이 균형수행력에 미치는 영향)

  • Chae Yun-Won;Kim Myung-Hoon;Cho Byeong-Mo
    • The Journal of Korean Physical Therapy
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    • v.12 no.1
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    • pp.65-71
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    • 2000
  • This study investigated the effect of anticipatory postural adjustment on balance performance in postural disturbance. Any action performed by standing subject is generally accompanied by compensatory postural activities, which reduce or abolish the postural disturbance generated by the movement and keep the subjects' center of gravity within the supporting base. These Postural activities arc triggered by either anticipatory and feedback postural control. We studied the difference of anticipatory and feedback postural control in postural disturbance. The subjects were standing on a foot plate with eyes closed, holding a lead of $5\%$ of their own body weight in their hands. The condition of anticipatory postural adjustment was applied voluntarily releases the a load. The condition of feedback postural control was applied that the load was unpredictably removed. We concluded that anticipatory postural adjustment becomes more efficient to postural performance in postural disturbance.

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Velocity Measurement of Granular Flow with Block Matching (블록 매칭을 이용한 Granular Flow의 속도 측정)

  • Lee, Jin-Geol
    • The Journal of Engineering Research
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    • v.2 no.1
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    • pp.5-11
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    • 1997
  • The flow of granular materials is common to many industrial processes. This paper discusses a methodology which utilizes high speed digital imaging to measure velocity of dry granular solids flowing down an inclined chute under the action of gravity. Glass particles have been used as granular solids in our experiment. The proposed technique utilizes block matching for spatially averaged velocity measurements of the glass particles. The velocity measurements are refined to the subpixel resolution by the variance normalized correlation with interpolation.

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Gamut Mapping Using Variable Anchor Points for Continuous Color Reproduction between Devices (장치간 연속 색 재현을 위한 가변 닻점 방식의 색역 사상)

  • 이채수;윤태진;한찬호
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 2001.05a
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    • pp.300-310
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    • 2001
  • In this paper, new gamut-mapping algorithm (GMA) that utilizes variable anchor points (center of gravity on the luminance axis) is proposed. The proposed algorithm increases luminance range, which is reduced from conventional gamut mapping toward an anchor point. In this process, this algorithm utilizes multiple anchor points with constant slopes to both reduce a sudden color change on the gamut boundary of the printer and to maintain a uniform color change during the mapping process. Accordingly, the proposed algorithm can reproduce high quality images with low-cost color devices.

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A Study on Optimal design of T-50 Aircraft FFP system through a case of F-16 Aircraft (최신 전투기 사례를 통한 T-50 FFP 시스템 최적 설계 연구)

  • Nam, Yong-seog;Kim, Tae-hwan;Jeong, Nyeon-su
    • Journal of Aerospace System Engineering
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    • v.4 no.1
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    • pp.10-14
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    • 2010
  • The Fuel system of T-50 Advanced Trainer is equipped with two boost pump and fuel flow proportioner for feeding fuel to turbo jet engine. when an unexpected failure occurs, they can feed the fuel to turbo jet engine which fuel quantity required. fuel quantity control method is applied for minimizing the center of gravity change. and fuel quantity control method is controlled by FQMS(Fuel Quantity Measuring System) and FFP(Fuel Flow Proportioner). This paper presents life cycle extension plans of FFP hydraulic motor by design improvements of connecting and arrangement of pipe comparing with KF-16.

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A Study on the Dielectric Degradation Using Partial Discharge System (부분방전 시스템을 이용한 절연 열화에 관한 연구)

  • 김성홍;이우상;정재용
    • Journal of the Korean Institute of Telematics and Electronics T
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    • v.35T no.1
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    • pp.1-6
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    • 1998
  • Our studies diagnose insulation degradation using the method of PD system. In analysis method of degradation, we make use of degradation information that analyzed the phase angle - PD pulse amplitude - degradation time( $\Phi$- PDA - t) pattern and phase angle- PD pulse number - degradation time( $\Phi$- PDN - t) pattern using statistical operators such as skewness(S), kurtosis(K). Secondly using statically operator such as the center of gravity (G), the gradient of the discharge distribution(C), we have analyzed for the prediction of life which we can be obtained the time, occurred of many pulse of small discharge amplitude.

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A Study on the Proper Transfer Distance for Minimizing Air Flotation Loss of Backfilling Material of NATM Composite lining Tunnel in the Model Test (충진 모형실험을 통한 NATM Composite 라이닝 터널 뒤채움재의 기포손실 최소화를 위한 적정 이송거리 고찰)

  • Ma, Sang-Joon;Choi, Hee-Sup;Lee, Heung-Soo;Kim, Kyung-Duk
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.1555-1558
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    • 2008
  • In this paper, result of whole test, When the Transfer Distance is increasing, Strength of Backfilling Material of NATM Composite lining Tunnel due to increasing Gravity was increased, but that is higher the Air Flotation than increasing Strength. So, That was predicted a drop of Permeability. And Performing the placing Lightweight Foamed Mortar, we think that it's performance in drain material was lost. Therefore We conclude that Proper Transfer Distance that taking Permeability through minimizing of Air Flotation Loss and getting the Need Strength is 50m.

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Structural Analysis for the Collapse Accident of Tower Crane (타워크레인 붕괴사고의 구조적 분석)

  • 이명구;노민래
    • Journal of the Korean Society of Safety
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    • v.16 no.4
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    • pp.147-152
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    • 2001
  • The tower cranes are the very useful construction machine in the high place works. But they are very susceptible to the load balance, the wind load and the hanging load because they are the very slender structures and those center of gravity is located in the upper part. Therefore, the collapse accidents of tower one have repeatedly happened during the assemble or disassemble works. The correcting frame may has often used in order to correct the error in the setting of foundation anchors. The goal of this study is that propose the methods preventible the collapse accident of tower crane which is constructed by using the correcting frame. In order to accomplish the goal of this study, the field survey, the reference investigation and the structure analysis were performed for the collapse accident of tower crane using the correcting frame. This study result in the methods preventible the same accident.

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Application of Forced Oscillation Technique for Pitch Dynamic Stability Derivatives of a Missile Model (미사일 모델의 피치 동안정미계수 측정을 위한 강제진동기법의 적용)

  • 김승필;조환기;백승욱
    • Journal of the Korea Institute of Military Science and Technology
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    • v.3 no.2
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    • pp.81-87
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    • 2000
  • This paper presents an application of forced oscillation technique to measure pitch dynamic stability derivatives of a missile model in the low speed wind tunnel. The missile model is oscillated by D.C. electric servomotor with constant amplitudes and frequencies. Phase shift is determined as the difference of peak values between input and output signals from the dynamic stability balance installed at the center of gravity of the model. Stability derivatives were calculated by using phase shifts, amplitudes, forcing moments and input frequencies. Test results show the proper usage of the force oscillation technique with good damping effects.

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A Study on the Stability of a Low Freeboard Coastwise Tanker Capsized in Turning (2) - Experimental Examination of the Outward Heel Moment Induced by Flooding of Seawater onto the Deck - (선회중 전복한 저건현 내항 탱커의 복원성에 관한 연구 (2) - 갑판상 해수 침입이 경사 모멘트에 미치는 영향에 대한 실험적 조사 -)

  • 김철승;공길영;김순갑
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2002.03a
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    • pp.145-153
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    • 2002
  • A coastwise chemical tanker sailing at full speed has capsized in calm water and whole turing. In the precious paper, we investigated reasons of the accident by demonstrating the proper correction for the free surface effect of the liquid cargo and the bow-sinkage effect. In this paper, we also carry out model experiments of a transverse pressure under the seawater and an outward heel moment according to the heel angle and rudder angle, on the basis of radius of turning circle, ship's speed and drift angle of model ship occurring in turning. It is also shown that the flooding of seawater onto the deck occurring in turning generated a significant outward heel moment and the vertical distance between the center of gravity of the ship and the renter of lateral water drag.

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Very High-speed Integer Fuzzy Controller Using VHDL

  • Lee Sang-Gu;Carpinelli John D.
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.5 no.3
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    • pp.274-279
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    • 2005
  • For high-speed fuzzy control systems, an important problem is the improvement of speed for the fuzzy inference, particularly in the consequent part and the defuzzification stage. This paper introduces an algorithm to map real values of the fuzzy membership functions in the consequent part onto an integer grid, as well as a method of eliminating the unnecessary operations of the zero items in the defuzzification stage, allowing a center of gravity method to be implemented with only integer additions and one integer division. A VHDL implementation of the system is presented. The proposed system shows approximately an order of magnitude increase in speed as compared with conventional methods while introducing only a minimal error and can be used in many fuzzy controller applications.