• 제목/요약/키워드: velocity kinematics

검색결과 273건 처리시간 0.026초

무인 컨테이너 트랜스포터의 조향 제어 (A Steering Control of the Unmanned Container Transporter)

  • 하희권;이영진;윤영진;허남;이만형
    • 한국항만학회지
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    • 제13권2호
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    • pp.381-388
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    • 1999
  • To improve the productivity in the harbor, successful development of an UCT(Unmanned Container Transporter) is needed. Well-designed steering and velocity control systems are the key factor for the development of the UCT. In this paper, a research concerning the achievement of the steering control is introduced. To get an information on the guide line that the UCT should track, the vision system is applied. By using neural network, proper steering angle is gotten fast with less influence of the image disturbance. A simulation based on the UCT kinematics is performed with the measured steering angle, and it shows satisfactory results.

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산화막 CMP에서 발생하는 온도가 연마특성에 미치는 영향 (Effect of Temperature on Polishing Properties in Oxide CMP)

  • 김영진;박범영;김형재;정해도
    • 한국전기전자재료학회논문지
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    • 제21권2호
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    • pp.93-98
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    • 2008
  • We investigated the effect of process temperature on removal rate and non-uniformity based on single head kinematics in oxide CMP. Generally, it has been known that the temperature profile directly transfers to the non~uniformity of removal rate on the wafer, which has similar tendency with the sliding distance of wafer. Experimental results show that platen velocity is a dominant factor in removal rate as well as average temperature. However, the non-uniformity does not coincide between process temperature and removal rate, due to slurry accumulation and low deviation of temperature. Resultantly, the removal rate is strongly dependent on the rotational speed of platen, and its non -uniformity is controlled by the rotational speed of polishing head. It means lower WIWNU (With-in-wafer-non-uniformity) can be achieved in the region of higher head speed.

Calibrating high-z QSO masses using near-IR and optical spectra

  • 김치푸옹;우종학
    • 천문학회보
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    • 제36권1호
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    • pp.48.2-48.2
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    • 2011
  • Using the newly commissioned Fiber-Multi-Object-Spectrograph at the Subaru telescope, we obtained near-IR spectra of a sample of 19 AGNs at 0.6 < z < 2.6, selected from the NOAO Deep Wide-Field Survey (NDWFS) Bootes field, in order to calibrate high-z black hole mass (MBH) estimators. MBHs are generally determined through the kinematics of ionized gas clouds around the black hole assuming virial equilibrium. The velocity profiles of $H{\beta}/H{\alpha}$, MgII and CIV are used to infer the gas kinematics of low-z, mid-z, and high-z quasars, respectively. However, the MBH based on MgII and CIV is not very well calibrated. We compare the $H{\alpha}$ - based MBH estimates from the new FMOS near-IR spectra, with the MgII-based MBH estimates from our existing optical spectra, and investigate the systematic differences.

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얀센 메커니즘 기반의 보행 기구 설계 (Design Walking System Based on Theo Jansen Mechanism)

  • 이현경;윤영규
    • EDISON SW 활용 경진대회 논문집
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    • 제5회(2016년)
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    • pp.404-410
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    • 2016
  • Compared to wheel locomotion, walking has many advantages : Better to cross over obstacles, the contact with ground is in a determined point, the ground is damaged less. Because Theo Jansen mechanism can make walking motion that is very soft, there are many researches about that mechanism. In this paper, We designed walking robot based on Theo Jansen mechanism. Most important design factor is velocity and stability. First of all, we considered kinematics knowledge and then, we made a new model by using simulation. Finally we developed the model by solving few design problems.

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A kinematic analysis of the Thai boxing clinch

  • Trial, William;Wu, Tom
    • Advances in biomechanics and applications
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    • 제1권1호
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    • pp.57-66
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    • 2014
  • The purpose of the study was to investigate the kinematics between the double collar-tie and double underhook Thai Boxing clinching positions. Ten amateur mixed martial arts athletes executed six knee strikes for both clinching positions with their dominant limb directed towards a target. A standard two-dimensional video motion analysis was conducted, and the results showed a statistical significant difference at the hip joint angle and the angular acceleration of the knee and ankle. Within both clinching positions, there was a statistically significant correlation between the hip and knee joint angles, hip and knee angular velocities, and hip angular acceleration. Between both clinching positions, there was a statistically significant correlation at the knee joint angle, knee angular velocity, and hip angular acceleration. This study demonstrates the importance of the hip and knee joint movements in both clinching positions, which implies the applications of strength training and flexibility at these joints for sports performance and injury prevention. It is suggested that future studies analyzing the non-dominant leg are warranted to fully understand the Thai Boxing clinch.

PSF Deconvolution on the Integral Field Unit Spectroscopy Data

  • 정하은;박창범
    • 천문학회보
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    • 제44권1호
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    • pp.58.4-58.4
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    • 2019
  • We present the application of the Point Spread Function (PSF) deconvolution method to the astronomical Integral Field Unit (IFU) Spectroscopy data focus on the restoration of the galaxy kinematics. We apply the Lucy-Richardson deconvolution algorithm to the 2D image at each wavelength slice. We make a set of mock IFU data which resemble the IFU observation to the model galaxies with a diverse combination of surface brightness profile, S/N, line-of-sight geometry and Line-Of-Sight Velocity Distribution (LOSVD). Using the mock IFU data, we demonstrate that the algorithm can effectively recover the stellar kinematics of the galaxy. We also show that lambda_R_e, the proxy of the spin parameter can be correctly measured from the deconvolved IFU data. Implementation of the algorithm to the actual SDSS-IV MaNGA IFU survey data exhibits the noticeable difference on the 2D LOSVD, geometry, lambda_R_e. The algorithm can be applied to any other regular-grid IFS data to extract the PSF-deconvolved spatial information.

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STaRS Gen 2: Sejong Radiative Transfer through Raman and Rayleigh Scattering in Dusty Medium

  • Chang, Seok-Jun;Lee, Hee-Won;Seon, Kwang-Il
    • 천문학회보
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    • 제46권2호
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    • pp.81.2-81.2
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    • 2021
  • Emission features formed through Raman scattering with atomic hydrogen provide unique and crucial information to probe the distribution and kinematics of a thick neutral region illuminated by a strong far-ultraviolet radiation source. We introduce a new 3-dimensional Monte-Carlo code to describe the radiative transfer of line photons subject to Raman and Rayleigh scattering with atomic hydrogen. In our Sejong Radiative Transfer through Raman and Rayleigh Scattering (STaRS) code, the position, direction, wavelength, and polarization of each photon is traced until escape. The thick neutral scattering region is divided into multiple cells. Each cell is characterized by its velocity and density, which ensures flexibility of the code in analyzing Raman-scattered features formed in a neutral region with complicated kinematics and density distribution. We are continuously developing STaRS to adopt the absorption and scattering effect by dust. This presentation introduces STaRS and its current state and study.

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Active Trajectory Tracking Control of AMR using Robust PID Tunning

  • Tae-Seok Jin
    • 한국산업융합학회 논문집
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    • 제27권4_1호
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    • pp.753-758
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    • 2024
  • Trajectory tracking of the AMR robot is one research for the AMR robot navigation. For the control system of the Autonomous mobile robot(AMR) being in non-honolomic system and the complex relations among the control parameters, it is d ifficult to solve the problem based on traditional mathematics model. In this paper, we presents a simple and effective way of implementing an adaptive tracking controller based on the PID for AMR robot trajectory tracking. The method uses a non-linear model of AMR robot kinematics and thus allows an accurate prediction of the future trajectories. The proposed controller has a parallel structure that consists of PID controller with a fixed gain. The control law is constructed on the basis of Lyapunov stability theory. Computer simulation for a differentially driven non-holonomic AMR robot is carried out in the velocity and orientation tracking control of the non-holonomic AMR. The simulation results of wheel type AMR robot platform show that the proposed controller is more robust than the conventional back-stepping controller to show the effectiveness of the proposed algorithm.

플랫폼 다이빙 624C동작의 운동학적 사례분석 (A Kinematics Analysis of Back Armstand 2 Somersault in Platform Dives a Case Study)

  • 이종희;소재무;임영태
    • 한국운동역학회지
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    • 제16권4호
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    • pp.13-20
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    • 2006
  • A platform diving with categorizing 624C motion was video taped and 3D kinematic variables were analyzed. This motion is consist of 3 parts from the headstand position to the act of turning after take-off. The results indicated that it took a very short time from the moment of take-off to the act of 1/2 turning because the turning motion has already started from preparing motion even before the fingertips have parted from the ground. Also, there was barely any jumping height due to the use of upper limbs segment and there was little difference in the moving distance compared to the standing events judging from horizontal movement of 1.1m. The horizontal velocity of the center of human body was increased before take-off while the vertical velocity was decreased right after take-off and the velocity of lower limbs segment was faster than the upper limbs segment showing contrary results to the standing events. In the aspects of angular velocity, the upper limbs segment starts the turning motion when take-off by rapidly extending its angular velocity while lower limbs segment make large angular velocity even before take-off.

ON THE PHYSICAL BASIS OF THE TULLY-FISHER RELATION

  • RHEE MYUNG-HYUN
    • 천문학회지
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    • 제37권1호
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    • pp.15-39
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    • 2004
  • We analyse the results of mass models derived from the HI rotation! curves of spiral galaxies and find that the slope of the luminous mass-circular velocity relation is close to 4. The luminous mass-circular velocity relation with a slope of about 4 can be explained by an anti-correlation between the mass surface density of luminous matter and the mass ratio of the dark and luminous components. We also argue that the conspiracy between luminous and dark matter exists in a local sense (producing a flat or smooth rotation curve) and in a global sense (affecting the mass ratio of the dark and luminous matter), maintaining the luminous mass-circular velocity relation with a slope of about 4. We therefore propose that the physical basis of the Tully-Fisher relation lies in the luminous mass-circular velocity relation. While the slope of the luminous mass-circular velocity relation is fairly well defined regardless of the dark matter contribution, the zero-point of the relation is still to be determined. The determination of the slope of the Tully-Fisher relation needs one more step: the mean trend of the luminosity-luminous mass relation determines the overall shape (slope) of the Tully-Fisher relation. The key parameter needed to determine the zero-point of the luminous mass-circular velocity relation and the slope of the Tully-Fisher relation obviously is the luminous mass-to-light ratio.