• Title/Summary/Keyword: Moving velocity

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Effect of Freezing Conditions on the Formation of Ice Crystals in Food during Freezing Process (식품의 동결중에 생성되는 빙결정에 미치는 동결조건의 영향)

  • 공재열;김정한;김민용;배승권
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.21 no.2
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    • pp.213-218
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    • 1992
  • The reaching time to the freezing point was to be fast in the order of 2% agar gel, 5% agar gel, 20% gelatin gel, pork, respectively. The freezing time and the passing time through the zone of the maximum ice crystal formation had linear relationship with the coolant temperature. The average diameter d$_{p}$ of ice crystal in a soybean protein gel and the moving of freezing front were represented an inverse proportion, and the moving velocity of freezing front was shown as 3.4$\times$10$^{-6}$ $\textrm{cm}^2$/sec from predicted theoretical formula. This value was very close to experimental results. The storage temperature did not give any influences for the growth of ice crystal in inside soybean protein gels during freezing conservation. The relationship between freezing condition and structure of freezing front was as follows : (moving velocity of freezing front) : (mass transfer rate of water at freezing point)$\times$(surface area of freezing front).

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Optical Flow Measurement Based on Boolean Edge Detection and Hough Transform

  • Chang, Min-Hyuk;Kim, Il-Jung;Park, Jong an
    • International Journal of Control, Automation, and Systems
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    • v.1 no.1
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    • pp.119-126
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    • 2003
  • The problem of tracking moving objects in a video stream is discussed in this pa-per. We discussed the popular technique of optical flow for moving object detection. Optical flow finds the velocity vectors at each pixel in the entire video scene. However, optical flow based methods require complex computations and are sensitive to noise. In this paper, we proposed a new method based on the Hough transform and on voting accumulation for improving the accuracy and reducing the computation time. Further, we applied the Boo-lean based edge detector for edge detection. Edge detection and segmentation are used to extract the moving objects in the image sequences and reduce the computation time of the CHT. The Boolean based edge detector provides accurate and very thin edges. The difference of the two edge maps with thin edges gives better localization of moving objects. The simulation results show that the proposed method improves the accuracy of finding the optical flow vectors and more accurately extracts moving objects' information. The process of edge detection and segmentation accurately find the location and areas of the real moving objects, and hence extracting moving information is very easy and accurate. The Combinatorial Hough Transform and voting accumulation based optical flow measures optical flow vectors accurately. The direction of moving objects is also accurately measured.

Optimal path planning for the capturing of a moving object

  • Kang, Jin-Gu;Lee, Sang-Hun;Hwang, Cheol-Ho;Lee, Jang-Myung
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1419-1423
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    • 2004
  • In this paper, we propose an algorithm for planning an optimal path to capture a moving object by a mobile robot in real-time. The direction and rotational angular velocity of the moving object are estimated using the Kalman filter, a state estimator. It is demonstrated that the moving object is tracked by using a 2-DOF active camera mounted on the mobile robot and then captured by a mobile manipulator. The optimal path to capture the moving object is dependent on the initial conditions of the mobile robot, and the real-time planning of the robot trajectory is definitely required for the successful capturing of the moving object. Therefore the algorithm that determines the optimal path to capture a moving object depending on the initial conditions of the mobile robot and the conditions of a moving object is proposed in this paper. For real-time implementation, the optimal representative blocks have been utilized for the experiments to show the effectiveness of the proposed algorithm.

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Optimal path planning for the capturing of a moving object

  • Hwang, Cheol-Ho;Lee, Sang-Hun;Ko, Jae-Pyung;Lee, Jang-Myung
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.186-190
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    • 2003
  • In this paper, we propose an algorithm for planning an optimal path to capture a moving object by a mobile robot in real-time. The direction and rotational angular velocity of the moving object are estimated using the Kalman filter, a state estimator. It is demonstrated that the moving object is tracked by using a 2-DOF active camera mounted on the mobile robot and then captured by a mobile manipulator. The optimal path to capture the moving object is dependent on the initial conditions of the mobile robot, and the real-time planning of the robot trajectory is definitely required for the successful capturing of the moving object. Therefore the algorithm that determines the optimal path to capture a moving object depending on the initial conditions of the mobile robot and the conditions of a moving object is proposed in this paper. For real-time implementation, the optimal representative blocks have been utilized for the experiments to show the effectiveness of the proposed algorithm.

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Influence of Two Moving Masses on Dynamic Behavior of a Simply Supported Pipe Conveying Fluid Flow (두 이동질량이 단순지지 유체유동 파이프의 동특성에 미치는 영향)

  • 윤한익;임순홍;유진석
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.13 no.8
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    • pp.605-611
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    • 2003
  • A simply supported pipe conveying fluid and two moving masses upon it constitute this nitration system. The equation of motion is derived by using Lagrange's equation. The influence of the velocities of two moving masses, the distance between two moving masses, and the velocities of fluid flow in the pipe have been studied on the dynamic behavior of a simply supported pipe by numerical method. The velocities of fluid flow are considered with in its critical values of a simply supported pipe without moving masses upon It. Their coupling effects on the transverse vibration of a simply supported pipe are inspected too. As the velocity of two moving masses increases, the deflection of a simply supported pipe is increased and the frequency of transverse vibration of a simply supported pipe is not varied. In case of small distance between two masses, the maximum deflection of the pipe occur when the front mass arrive at midspan. Otherwise as the distance get larger, the position of the front masses where midspan deflection is maximum moves beyond the midpoint of a simply supported pipe. The deflection of a simply supported pipe is increased by coupling of the velocities of moving masses and fluid flow.

Extraction of Ocean Surface Current Velocity Using Envisat ASAR Raw Data (Envisat ASAR 원시자료를 이용한 표층 해류 속도 추출)

  • Kang, Ki-Mook;Kim, Duk-Jin
    • Korean Journal of Remote Sensing
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    • v.29 no.1
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    • pp.11-20
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    • 2013
  • Space-borne Synthetic Aperture Radar(SAR) has been one of the most effective tools for monitoring quantitative oceanographic physical parameters. The Doppler information recorded in single-channel SAR raw data can be useful in estimating moving velocity of water mass in ocean. The Doppler shift is caused by the relative motion between SAR sensor and the water mass of ocean surface. Thus, the moving velocity can be extracted by measuring the Doppler anomaly between extracted Doppler centroid and predicted Doppler centroid. The predicted Doppler centroid, defined as the Doppler centroid assuming that the target is not moving, is calculated based on the geometric parameters of a satellite, such as the satellite's orbit, look angle, and attitude with regard to the rotating Earth. While the estimated Doppler shift, corresponding to the actual Doppler centroid in the situation of real SAR data acquisition, can be extracted directly from raw SAR signal data, which usually calculated by applying the Average Cross Correlation Coefficient(ACCC). The moving velocity was further refined to obtain ocean surface current by subtracting the phase velocity of Bragg-resonant capillary waves. These methods were applied to Envisat ASAR raw data acquired in the East Sea, and the extracted ocean surface currents were compared with the current measured by HF-radar.

Vibration Characteristics of Pipe Element Containing Moving Medium by a Transfer Matrix (전달행렬을 이용한 유동매체를 가진 배관요소의 진동특성 분석)

  • 이영신;천일환
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.15 no.1
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    • pp.366-375
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    • 1991
  • In this study, vibrational behavior of uniform pipe carrying a moving medium is studied by using a transfer matrix and the displacement function derived from the conventional beam theory. In various boundary conditions, flow velocity and mechanical property change of the variation of natural frequency are investigated. The Coriolis term in the original differential equation of motion has been ignored in the investigation. This method is used to study the variation of natural frequency with flow velocity for clamped-clamped, cantilevered, clamped-pinned, pinned-pinned, free-free straight pipe element. It is shown that clamped-clamped, free-free pipe have the highest natural frequency and critical velocity values while cantilevered pipe have the smallest natural frequency for the same mechanical properties. From the vibration effects of mechanical property variation, it is shown that bending stiffness and pipe length variation has large influence on natural frequency and critical velocity. Since the order of transfer matrix is not changed with boundary conditions of pipe element, this method proposed can be easily applied to personal-computer for vibration analysis of pipe element. Furthermore, this method can be extended to three-dimensional system by using a coordinate transformation for the analysis of piping systems.

Optimal configuration control for redundant robot manipulators-manipulability-based approach (여유 자유도 로봇의 최적 자세 제어)

  • Lee, Ji-Hong;Lee, Mi-Gyung;Lee, Young-Il;Yoo, Jun
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.739-742
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    • 1996
  • Several figures representing velocity transmission from joint space to task space are analyzed and compared with each other. The figures include velocity ellipsoid derived from Jacobian matrix, scaled velocity ellipsoid derived from normalized joint velocities, polytope derived by numerical scaling, and polytopes derived by linear combinations of Jacobian column vectors. The results show that the optimal directions given by the measures are not the same and the conventional velocity ellipsoid is not good choice as optimization measure as far as the moving direction is concerned. Simulation examples for 3 d.o.f. redundant robot manipulators in 2-dimensional task space are given for comparison study.

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A Modified Velocity Estimation Scheme in AAS (Adaptive Antenna System) (AAS(적응형 안테나 시스템)에서의 이동체 속도 추정 방안)

  • Chung, Young-Uk;Choi, Yong-Hoon;Lee, Hyuk-Joon
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.8 no.2
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    • pp.100-107
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    • 2009
  • Velocity estimation is one of important issues for efficient system management in mobile cellular systems. In this paper, a modified velocity estimation scheme which works in Adaptive Antenna System (AAS) is proposed. The proposed scheme estimates user velocity based on moving distance information and sojourn time information. From numerical results, it is shown that the proposed scheme can estimate user velocity accurately with low cost.

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