• 제목/요약/키워드: residual motion

검색결과 238건 처리시간 0.024초

분산 압축 비디오 센싱을 위한 MC-BCS-SPL 기법의 안정화 알고리즘 (A Stabilization of MC-BCS-SPL Scheme for Distributed Compressed Video Sensing)

  • 류중선;김진수
    • 한국멀티미디어학회논문지
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    • 제20권5호
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    • pp.731-739
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    • 2017
  • Distributed compressed video sensing (DCVS) is a framework that integrates both compressed sensing and distributed video coding characteristics to achieve a low complexity video sampling. In DCVS schemes, motion estimation & motion compensation is employed at the decoder side, similarly to distributed video coding (DVC), for a low-complex encoder. However, since a simple BCS-SPL algorithm is applied to a residual arising from motion estimation and compensation in conventional MC-BCS-SPL (motion compensated block compressed sensing with smoothed projected Landweber) scheme, the reconstructed visual qualities are severly degraded in Wyner-Ziv (WZ) frames. Furthermore, the scheme takes lots of iteration to reconstruct WZ frames. In this paper, the conventional MC-BCS-SPL algorithm is improved to be operated in more effective way in WZ frames. That is, first, the proposed algorithm calculates a correlation coefficient between two reference key frames and, then, by selecting adaptively the reference frame, the residual reconstruction in pixel domain is performed to the conventional BCS-SPL scheme. Experimental results show that the proposed algorithm achieves significantly better visual qualities than conventional MC-BCS-SPL algorithm, while resulting in the significant reduction of the decoding time.

Residual drift analyses of realistic self-centering concrete wall systems

  • Henry, Richard S.;Sritharan, Sri;Ingham, Jason M.
    • Earthquakes and Structures
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    • 제10권2호
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    • pp.409-428
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    • 2016
  • To realise the full benefits of a self-centering seismic resilient system, the designer must ensure that the entire structure does indeed re-center following an earthquake. The idealised flag-shaped hysteresis response that is often used to define the cyclic behaviour of self-centering concrete systems seldom exists and the residual drift of a building subjected to an earthquake is dependent on the realistic cyclic hysteresis response as well as the dynamic loading history. Current methods that are used to ensure that re-centering is achieved during the design of self-centering concrete systems are presented, and a series of cyclic analyses are used to demonstrate the flaws in these current procedures, even when idealised hysteresis models were used. Furthermore, results are presented for 350 time-history analyses that were performed to investigate the expected residual drift of an example self-centering concrete wall system during an earthquake. Based upon the results of these time-history analyses it was concluded that due to dynamic shake-down the residual drifts at the conclusion of the ground motion were significantly less than the maximum possible residual drifts that were observed from the cyclic hysteresis response, and were below acceptable residual drift performance limits established for seismic resilient structures. To estimate the effect of the dynamic shakedown, a residual drift ratio was defined that can be implemented during the design process to ensure that residual drift performance targets are achieved for self-centering concrete wall systems.

Linux/RTAI기반의 잔류진동 억제 입력성형 구현 (Linux/RTAI-based Input Shaping Implementation for Suppressing Residual Vibrations)

  • 우교식;김진우;강철구;이동제;박경희;김형철
    • 로봇학회논문지
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    • 제4권3호
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    • pp.250-256
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    • 2009
  • Suppressing residual vibrations of flexible materials cheaply is an important issue to increase productivity of automated factory using wafer or glass handling robots. In this paper, we present Linux/RTAI-based implementation of input shaping control for reducing residual vibrations of a mechanical system. Experimental results show that residual vibrations of the mechanical system are reduced up to 82% at a point-to-point linear motion.

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타이어와 차량 쏠림 II-이론적 배경, Simulation, 실차검증 (Tire and Vehicle Pull II- Basic Theory, Simulation, and Verification)

  • 이정환;문승환
    • 한국자동차공학회논문집
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    • 제8권5호
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    • pp.157-164
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    • 2000
  • It is known that residual aligning torque of tires causes vehicle pull. There is, however, only a little literature available which shows how the residual aligning torque of tires causes vehicle pull. In this paper, a vehicle model in two degrees of freedom was adopted for the analysis of a vehicle under the straight-ahead motion. The analysis with this vehicle model clearly shows the effect of residual aligning torque of tires on vehicle pull. In order to show the validity of the analysis, a vehicle commercially available was selected. This vehicle was modeled in 137 degrees of freedom system with multibody dynamics software. Vehicle pull simulation results show that vehicle model drifts in lateral direction due to the residual aligning torque of tires. Vehicle test results with the car were also included.

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차륜/래일 접촉에 의한 차륜의 잔류응력 평가 (Evaluation of Residual Stress of railway wheel)

  • 서정원;구병춘;정흥채
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2003년도 춘계학술대회 논문집
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    • pp.668-673
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    • 2003
  • A wheel and axle failure can cause a derailment with its attendant loss of life and property. The service conditions of railway vehicles have become severe in recent years due to a general increase in operating speeds. Damages of railway wheel are a spalling by wheel/rail contact and thermal crack by braking heat etc. One of the main source of damage is a residual stress. therefore it is important to evaluate exactly. A Residual stress of wheel is formed at the process of heat treatment when manufacturing. it is changed by contact stress developed by wheel/rail contact. Distributions of residual stress vary according to a magnitude of wheel load, a magnitude of friction when acceleration and deceleration. The objective of this paper is to estimate the influence of wheel motion on the residual stress distribution in the vicinity of the running surface.

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Displacements, damage measures and response spectra obtained from a synthetic accelerogram processed by causal and acausal Butterworth filters

  • Gundes Bakir, Pelin;Richard, J. Vaccaro
    • Structural Engineering and Mechanics
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    • 제23권4호
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    • pp.409-430
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    • 2006
  • The aim of this study is to investigate the reliability of strong motion records processed by causal and acausal Butterworth filters in comparison to the results obtained from a synthetic accelerogram. For this purpose, the fault parallel component of the Bolu record of the Duzce earthquake is modeled with a sum of exponentially damped sinusoidal components. Noise-free velocities and displacements are then obtained by analytically integrating the synthetic acceleration model. The analytical velocity and displacement signals are used as a standard with which to judge the validity of the signals obtained by filtering with causal and acausal filters and numerically integrating the acceleration model. The results show that the acausal filters are clearly preferable to the causal filters due to the fact that the response spectra obtained from the acausal filters match the spectra obtained from the simulated accelerogram better than that obtained by causal filters. The response spectra are independent from the order of the filters and from the method of integration (whether analytical integration after a spline fit to the synthetic accelerogram or the trapezoidal rule). The response spectra are sensitive to the chosen corner frequency of both the causal and the acausal filters and also to the inclusion of the pads. Accurate prediction of the static residual displacement (SRD) is very important for structures traversing faults in the near-fault regions. The greatest adverse effect of the high pass filters is their removal of the SRD. However, the noise-free displacements obtained by double integrating the synthetic accelerogram analytically preserve the SRD. It is thus apparent that conventional high pass filters should not be used for processing near-fault strong-motion records although they can be reliably used for far-fault records if applied acausally. The ground motion parameters such as ARIAS intensity, HUSID plots, Housner spectral intensity and the duration of strong-motion are found to be insensitive to the causality of filters.

Effect of near and far-field earthquakes on RC bridge with and without damper

  • Soureshjani, Omid Karimzade;Massumi, Ali
    • Earthquakes and Structures
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    • 제17권6호
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    • pp.533-543
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    • 2019
  • This paper presents a study on the behavior of an RC bridge under near-field and far-field ground motions. For this purpose, a dynamic nonlinear finite element time history analysis has been conducted. The near-field and far-field records are chosen pairwise from the same events which are fits to the seismic design of the bridge. In order to perform an accurate seismic evaluation, the model has been analyzed under two vertical and horizontal components of ground motions. Parameters of relative displacement, residual displacement, and maximum plastic strain have been considered and compared in terms of near-field and far-field ground motions. In the following, in order to decrease the undesirable effects of near-field ground motions, a viscous damper is suggested and its effects have been studied. In this case, the results show that the near-field ground motions increase maximum relative and residual displacement respectively up to three and twice times. Significant seismic improvements were achieved by using viscous dampers on the bridge model. Somehow under the considered near-field ground motion, parameters of residual and relative displacement decrease dramatically even less than the model without damper under the far-field record of the same ground motion.

외상성 구획증후군의 감압술 후 잔여 증상에 대한 치료 1례 (A Clinical Case Study of Residual Symptoms after Decompression of Traumatic Compartment Syndrome)

  • 지민정;임성철;김재수;이현종;이윤규
    • Journal of Acupuncture Research
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    • 제32권3호
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    • pp.197-202
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    • 2015
  • Objectives : The purpose of this study is to report on the residual symptoms after decompression of traumatic compartment syndrome experienced by a patient whose condition was much improved by electroacupuncture and bee venom therapy. Methods : The patient was treated with electroacupuncture and bee venom therapy. The progress of symptoms was checked by visual analog scale, disabilities of the arm, shoulder, and hand(DASH) and range of motion. Results : All results were improved. Scores from the visual analog scale and DASH decreased, while the range of motion increased. Conclusions : Electroacupuncture and bee venom therapy have an effect on residual symptoms after decompression of traumatic compartment syndrome.

Respiratory Motion Correction on PET Images Based on 3D Convolutional Neural Network

  • Hou, Yibo;He, Jianfeng;She, Bo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제16권7호
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    • pp.2191-2208
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    • 2022
  • Motion blur in PET (Positron emission tomography) images induced by respiratory motion will reduce the quality of imaging. Although exiting methods have positive performance for respiratory motion correction in medical practice, there are still many aspects that can be improved. In this paper, an improved 3D unsupervised framework, Res-Voxel based on U-Net network was proposed for the motion correction. The Res-Voxel with multiple residual structure may improve the ability of predicting deformation field, and use a smaller convolution kernel to reduce the parameters of the model and decrease the amount of computation required. The proposed is tested on the simulated PET imaging data and the clinical data. Experimental results demonstrate that the proposed achieved Dice indices 93.81%, 81.75% and 75.10% on the simulated geometric phantom data, voxel phantom data and the clinical data respectively. It is demonstrated that the proposed method can improve the registration and correction performance of PET image.

입력 성형과 유전 알고리즘에 의한 자벌레 운동제어 (Motion Control of Inchworm using Input Shaping and Genetic Algorithm)

  • 김인수;김기범;박승민
    • 한국생산제조학회지
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    • 제26권3호
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    • pp.313-319
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    • 2017
  • This study presents a genetic algorithm (GA) to design a PID controller systematically for an inchworm operated by piezoelectric actuators. The performance index considering overshoot and settling time is adopted to search an optimal PID gain using GA. The piezoelectric actuator shows nonlinear characteristics including hysteresis and residual displacement. The PID feedback system combined with an integrator is used to improve the ability of tracking the complex input signals and suppressing the steady state error. The PID controller tuned by GA can track the various motion contours effectively. However, the PID controller shows an improper residual vibration under the application of high-frequency square input. The input shaper combined with the feedback system can overcome this limitation of the PID controller.