• Current Optics and Photonics
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• v.7 no.1
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• pp.54-64
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• 2023

This paper proposes dynamic viewing-zone switching for a binocular holographic three-dimensional display with low interpupil crosstalk and an extended eye-motion box. The optimal pupil geometry for reducing interpupil crosstalk is designed. It is shown that the eye-motion box can be extended by exploiting signal replication in the higher-order viewing zone. Design principles and numerical simulations for verification of the binocular holographic head-up display are presented.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.14 no.2
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• pp.68-77
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• 2008

Purpose : The purpose of this study was to investigate effects of movement with mobilization(MWM) and stabilization exercise on pain and range of motion of patients with acute low back pain. Methods : The subjects were consisted of 24 patients who had non specific acute low back pain. All subjects randomly assigned to the MWM group and the stabilization exercise group. The MWM group received sustained natural apophyseal glides(SNAGs) with modality treatment and stabilization exercise group received stabilization exercise with modality treatment. The remodified schober test(RST) was used to measure forward flexion and lateral flexion range of motion of lumbar segment. Visual Analogue Scale(VAS) was used to measure subjective pain level of the patients. The Oswestry Low Back Pain Disability Scale was used to measure functional disability level of the patients. Results : The lumbar flexion range of motion of MWM group was significantly increased compared with stabilization exercise group(p<.01). The range of motion of lumbar segment of MWM group was significantly decreased compared with stabilization exercise group(p<.01). The left lateral flexion range of motion of lumbar of MWM group was significantly decreased compared with stabilization exercise group(p<.05). The right lateral flexion range of motion of lumbar of MWM group was significantly decreased compared with stabilization exercise group(p<.05). The VAS of both MWM group and stabilization exercise group was significantly decreased(p<.001). The Oswestry Low Back Pain Disability Scale of stabilization exercise group was significantly increased compared with mobilization group(p<.001). Conclusion : In the result of this study, mobilization with movement and stabilization exercise had significant difference on pain and flexibility of patients with acute low back pain.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.3
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• pp.45-52
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• 1992

The Mathematical Model, which can describe the maneuvering motion of a ship in low speed, is highly required these days because it is directly related to the safety of ship in confused harbour. Kose has presented a new model for the low speed maneuvering motion, but the usefulness of it is not confirmed widely. Lets of difficulties are revealed in the case of low speed maneuver, The first is the fact that a ship moves the stirred water region for the longer time than in the case of high speed. So, the hydrodynamic forces, exerted on the hull need to be treated strictly, not by the ordinary differential equation with constant coefficients. Another difficulty is arised from the fact the lateral motion is relatively large comparing to the longitudinal motion in low speed. And, by the result the effect of cross-flow drag or vortex sheding effects are dominant. Besides, the captive model tests of low speed motion has lots of problems. For example, the hydrodynamic forces do not converge to a certain values for the long time. And the absolute values of measured forces are very small, so we must expend lots of efforts to raise up the S/N ratio of the experiments. In this paper, a new mathematical model for the maneuvering motion in low speed, is built up, and the usefulness is discussed, comparing with other models, for example, Kose's model or M.M.G. model or Cross-Flow model, The CMT data for a PCC model of 3.00 M length, released from the RR-742 of Japan, are used for the validation of each models.

• Journal of The Korean Society of Integrative Medicine
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• v.12 no.2
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• pp.33-45
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• 2024

Purpose : This study aimed to compare the effects of spinal manipulation combined with medication on low back pain (LBP), range of motion, and disability in patients with chronic LBP. Methods : Twenty patients with chronic LBP were included in this study. The participants were randomly assigned to the spinal manipulation with medication group (n=10) or the medication only group (n=10). The intervention group received spinal manipulation for 15 minutes, twice a week, and took medication twice a day for eight weeks. The control group received the medication twice daily for eight weeks. Pain intensity assessed using the visual analog scale (VAS), range of motion, and disability due to LBP assessed using the Oswestry disability index were measured before and after the intervention. Results : The intervention group showed a significant improvement in pain intensity compared to the control group (p<.05), and the intervention and control groups significantly improved low back pain after the intervention (p<.05). The intervention group showed a significant improvement in the range of motion in flexion, extension, right lateral flexion, left lateral flexion, and right rotation (p<.05). The intervention group also showed a significant improvement in the change of disability in total score, pain intensity, personal care, lifting and standing compared to the control group (p<.05). Conclusion : This study showed that the combination of spinal manipulation and medication can benefit patients with chronic LBP, as evidenced by significant improvements in pain intensity, ROM, and disability. These findings suggest that utilizing both spinal manipulation and medication can positively affect individuals with chronic LBP. The results of this study should be applied in clinical settings to optimize treatment outcomes in patients with chronic LBP.

• Journal of Digital Convergence
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• v.10 no.10
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• pp.313-318
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• 2012

In this study, we propose a low-noise transceiver for 10GHz motion sensor. The transceiver presented here has a circuit(Hittite HMC908LC5) that is composed of a two way-$0^{\circ}$ power splitter(the 1:2 block) and a $90^{\circ}$ Hybrid. The noise reduction circuit utilizes an LNA followed by an image reject mixer which is driven by an LO buffer amplifier. A modeling and analysis have been pursued using CST MWS. A prototype sensor was manufactured to measure the performance and experimental results show that the proposed sensor is good enough to use for a accurate motion sensor.

• Journal of Ocean Engineering and Technology
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• v.2 no.2
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• pp.37-45
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• 1988

A dynamically positioned vessel must be capable of maintaining a specified position and direction by controlling the thruster devices. The motions of a vessel are often assuned to tne sum of low frequency(LF)motions and high frequency(HF)motions. The former is mainly due to wind, current and second order wave forces, while the latter is mainly due to first order wave forces. In order to avoid the high frequency thruser modulation, the control system must include filters to estimate the low frequency motions from the measured motion signals, This paper presents a control system based on Kalman filtering technique and optimal control tyeory. Using the combined kalmam filter, LF motion estimates and HF ones are achieved from the motion measurement of the vessel. The estimated low frequency motions are used as inputs to the dynamic positioning system. The thruster modulation is minimized using the optimal control theory; Linear Quadratic Gaussian(LQG)controller. The performances of the Kalman filter and the dynamic positioned vessel are investigated by computer simulation.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.339-342
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• 2005

We present an efficient block-based motion estimation algorithm with motion analysis. The motion analysis determines a size of search pattern and a maximum repeated count of search pattern. In case of large movement in large image, we reduce search points and the local minimum which caused by low performance. The proposed algorithm employs with searching step of 2. The first step determines an initial search point with neighbor block vector and a size of initial search pattern. The second step determines a size of search pattern and a maximum repeated count with motion analysis. We improve motion prediction accuracy while reducing required computational complexity compared to other fast block-based motion estimation algorithms.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.3
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• pp.96-108
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• 1996

In this paper, we propose an object-oriented coding method in low bit-rate channels using block-based motion vectors and residual image compensation. First, we use a 2-stage algorithm for estimating motion parameters. In the first stage, coarse motion parameters are estimated by fitting block-based motion vectors and in the second stage, the estimated motion parametes are refined by the gradient method using an image reconstructed by motion vectors detected in the first stage. Local error of a 6-parameter model is compensted by blockwise motion parameter correction using residual image. Finally, model failure (MF) region is reconstructed by a fractal mapping method. Computer simulation resutls show that the proposed method gives better performance than the conventional ones in terms of th epeak signal to noise ratio (PSNR) and compression ratio (CR).

• Journal of the Korea Society of Computer and Information
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• v.20 no.9
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• pp.39-45
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• 2015

Along with the advance of digital technology, various methods are adopted for capturing the 3D animating data. Especially, in 3D animation production market, the motion capture system is widely used to make films, games, and animation contents. The technique quickly tracks the movements of the actor and translate the data to use as animating character's motion. Thus the animation characters are able to mimic the natural motion and gesture, even face expression. However, the conventional motion capture system needs tricky conditions, such as space, light, number of camera etc. Furthermore the data acquired from the motion capture system is frequently corrupted by noise, drift and surrounding environment. In this paper, we introduce the post production techniques to stabilizing the jitters of motion capture data from the low cost handy system based on Kinect.

• Journal of Information Processing Systems
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• v.7 no.1
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• pp.103-110
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• 2011

In this paper, an adaptive motion vector smoothing scheme based on weighted vector median filtering is proposed in order to eliminate the motion outliers more effectively for improving the quality of side information in frame-based distributed video coding. We use a simple motion vector outlier reliability measure for each block in a motion compensated interpolated frame and apply weighted vector median filtering only to the blocks with unreliable motion vectors. Simulation results show that the proposed adaptive motion vector smoothing algorithm improves the quality of the side information significantly while maintaining low complexity at the encoder in frame-based distributed video coding.