• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.13 no.2
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• pp.31-44
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• 2007

The purposes of this study were to examine the normal lumbar proprioception and identify the effect of vision and proprioception on lumbar movement accuracy through measuring a reposition error in visual and non-visual conditions and to provide the basic data for use of vision when rehabilitation program is applied. The subjects of this study were 39 healthy university students who have average physical activity level. They were measured the ability to reproduce the target position(50% of maximal range of motion) of flexion, extension, dominant and non-dominant side flexion in visual and non-visual conditions. Movement accuracy was assessed by reposition error(differences between intended and actual positions) that is calculated by the average of absolute value of 3 repeated measures at each directions. The data were analysed by paired samples t-test, independent samples t-test, and repeated measures ANOVA. The results were as follows : 1. Movement accuracy of flexion, extension, dominant side flexion, and non-dominant side flexion was increased in visual condition. 2. There were no differences in the lumbar movement accuracy between sexes in visual and non-visual conditions. 3. In non-visual condition, the movement in coronal plane(dominant and non dominant side flexion) is more accurate than that in sagittal plane(flexion and extension). 4. In non-visual condition, there were no differences in the lumbar movement accuracy between dominant and non-dominant side flexion. In conclusion, this study demonstrates that the movement is more accurate when the visual information input is available than proprioception is only available. When proprioception is decreased by injury or disease, it disturbs the control of posture and movement. In this case, human controls the posture and movement by using visual compensation. However it is impossible to prevent an injury or trauma because most of injuries occur in an unexpected situation. For this reason, it is important to improve the proprioception. Therefore, proprioceptive training or exercise which improve the ability to control of posture and movement is performed an appropriate control of permission or interception of the visual information input to prevent an excessive visual compensation.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.4
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• pp.98-106
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• 2011

Since prediction processes such as motion estimation motion compensation are not at the WZ video encoder but at its decoder, WZ video compression cannot have better performance than that of conventional video encoder. In order to implement the prediction process with low complexity at the encoder, WZ residual coding was proposed. Instead of original WZ frames, WZ residual coding encodes the residual signal between key frames and WZ frames. Although the proposed WZ residual coding has good performance in pixel domain, it does not have any improvements in transform domain compared to transform domain WZ coding. The WZ residual coding in transform domain is difficult to have better performance, because pre-defined quantization matrices in WZ coding are not compatible with WZ residual coding. In this paper, we propose a new quantization method modifying quantization matrix and quantization step size adaptively for transform domain WZ residual coding. Experimental result shows 22% gain in BDBR and 1.2dB gain in BDPSNR.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.10C
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• pp.933-941
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• 2006

In this paper, we proposed an efficient coding method for digital hologram (fringe pattern) acquired by a CCD camera or by computer generation using multi-view prediction technique and MPEG video compression standard technique. It proceeds each R, G, or B color component separately. The basic processing unit is a partial image segmented into the size of $N{\times}N$. Each partial image retains the information of the whole object. This method generates an assembled image for a row of the segmented and frequency-transformed partial images, which is the basis of the coding process. That is, a motion estimation and compensation technique of MPEG is applif:d to the reconstructed images from the assembled images with the disparities found during generation of assembled image and the original partial images. Therefore the compressed results are the disparity of eachpartial image to form the assembled image for the corresponding row, assembled image, and the motion vectors and the compensated image for each partial image. The experimental results with the implemented algorithm showed that the proposed method has NC (Normal Correlation) values about 4% higher than the previous method, by which ours has better compression efficiency. Consequently, the Proposed method is expected to be used effectively in the application areas to transmit the digital hologram data. can be identified in comparison with the previous researches and commercial IPs.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.4
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• pp.285-293
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• 2020

In this paper, to improve Synthetic Aperture Radar (SAR) image quality, the effect of time synchronization error in the EGI/IMU (Embedded GPS/INS, Inertial Measurement Unit) integrated system is analyzed and state augmentation is applied to compensate it. EGI/IMU integrated system is widely used as a SAR motion measurement algorithm, which consists of EGI mounted to obtain the trajectory and IMU mounted on the SAR antenna. In an EGI/IMU integrated system, a time synchronization error occurs when the clocks of the sensors are not synchronized. Analysis of the effect of time synchronization error on navigation solutions and SAR images confirmed that the time synchronization error deteriorates SAR image quality. The state augmentation is applied to compensate for this and as a result, the SAR image quality does not decrease. In addition, by analyzing the performance and the observability of the time synchronization error according to the maneuver, it was confirmed that the time-variant maneuver such as rotational motion is necessary to estimate the time synchronization error adequately. In order to reduce the influence of the time synchronization error on the SAR image, the time synchronization error must be compensated by performing maneuver changing over time such as a rotation before SAR operation.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.1
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• pp.11-21
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• 2008

In conventional video coding, the complexity of encoder is much higher than that of decoder. However, as more needs arises for extremely simple encoder in environments having constrained energy such as sensor network, much investigation has been carried out for eliminating motion prediction/compensation claiming most complexity and energy in encoder. The Wyner-Ziv coding, one of the representative schemes for the problem, reconstructs video at decoder by correcting noise on side information using channel coding technique such as turbo code. Since the encoder generates only parity bits without performing any type of processes extracting correlation information between frames, it has an extremely simple structure. However, turbo decoding errors occur in noisy side information. When there are high-motion or occlusion between frames, more turbo decoding errors appear in reconstructed frame and look like Salt & Pepper noise. This severely deteriorates subjective video quality even though such noise rarely occurs. In this paper, we propose a computationally extremely light encoder based on symbol-level Wyner-Ziv coding technique and a new corresponding decoder which, based on a decision whether a pixel has error or not, applies median filter selectively in order to minimize loss of texture detail from filtering. The proposed method claims extremely low encoder complexity and shows improvements both in subjective quality and PSNR. Our experiments have verified average PSNR gain of up to 0.8dB.

• Korean Journal of Applied Biomechanics
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• v.31 no.2
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• pp.133-139
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• 2021

Objective: This study aims to verify the conventional deadlift motions using by two different grips, thereby elucidating the grounds for effective training methods that can minimize the risk of injury. Method: Total of 18 healthy young adults were recruited for this study (age: 25.11±2.19 yrs., height: 175.67±5.22 cm, body mass: 78.5±8.09 kg, 1-RM: 125.75±19.48 kg). All participants were asked to perform conventional deadlift with two types of grips which are overhand grip (OG) and underhand grip (UG). In each grip, participant perform the deadlift with 50% and 80% of the pre-measured 1-RM. A 3-dimensional motion analysis with 8 infrared cameras and 3 channels of EMG was performed in this study. A two-way ANOVA (group × load) with repeated measure was used for statistical verification. The significant level was set at α=.05. Results: There were significant differences in grip type and weight on the right shoulder joint, and only significant difference in grip on the left shoulder joint (p<.05). The hip joint ROM was significantly increased as the weight increased in both types of grips on phase 1, while the ROM of hip joint was significantly decreased as the weight increased only in the case of OG on phase 2 (p<.05). In case of the OG, as the weight, increased significantly increased L1 ROM and L3 ROM were revealed on phase 1 and phase 2, respectively (p<.05). Moreover, as the weight increased, UG revealed significantly decreased L5 ROM on phase 1, while both grips showed significantly increased ROM on phase 2 (p<.05). In addition, the erector spinae and the biceps femoris, which are synergist for the motion, showed a significant difference in both types of grip according to the weight (p<.05). The muscle activity ratio of gluteus maximus/biceps femoris showed a significant difference only in the UG according to the weight (p<.05). Conclusion: In conclusion, beginners might be suggested to use the UG for maintaining the neutral state of the lumbar spine and focus on the gluteus maximus muscle, which is the main activation muscle. For the experts, it may recommend alternative use of the OG and UG according to the training purpose to minimize the compensation effect.

• Journal of Broadcast Engineering
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• v.2 no.2
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• pp.114-124
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• 1997

In object based coding, binary shape ccx:ling plays an important role by ccx:ling the outer shape of object. Here we propose a new shape ccx:ling tool, which enccx:les the outline of shape from a baseline. Different from 2-D (Vertex) shape ccx:ling algorithms. the proposed method encodeds the data that are extracted in a I-D fashion. The enccx:led data consist of the starting position, distance lists, and turning point lists. In the lossless ccx:ling mode, every contour pixel is input for ccx:ling, whereas variable sampling has been employed to enccx:le fewer contour pixels while preserving reasonable distortion. For interframe ccx:ling, a fast motion compensation was achieved by use of distance and turning point lists. Subjective viewing tests proved that the proposed method outperforms the current shape ccx:ling standard, CAE, in MPEG-4. In objective results for compression efficiency, the proposed method was significantly better in intraframe coding than CAE, whereas CAE was better in interframe ccx:ling.

• Journal of Broadcast Engineering
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• v.2 no.2
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• pp.86-93
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• 1997

Fast growth of multimedia applications requires new functions for video data processing. such as obj;cted-based video representation and manipulation. which are not supported by 11PEG-l and 11PEG-2. To support these requirements. 11PEG-4 video coding allows users to manipulate every video object easily by decomposing a scene into several video objects and coding each of them independently. However. the large amount of computations and flexible structure of 11PEG-4 video CODEC make it difficult to be implemented by either the general purpose DSP or a dedicated VLSI. In this paper, we propose a hardware architecture using a hybrid of a high performance programmable DSP and an application specific IC to implement a flexible 11PEG-4 video codec requiring the large amount of computations. The application specific IC has the functions of motion estimation and compensation.

• Korean Parent-Child Health Journal
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• v.15 no.1
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• pp.39-49
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• 2012

Purpose: This study examined grandmothers' experience of child care with grandchildren to understand how it affects their stage of life based on the methodology of grounded theory. Methods: This study used grounded theory, a method of qualitative study, as the theoretical foundation. The subjects of this study were 10 grandmothers who have reared their grandchildren for at least 6 months and volunteered to participate in the study after listening to an explanation. Resources were collected through in-depth interviews and the interviews were recorded and dictated. Results: The core category of participants in this study was "solidifying the family relationship". There were five steps in the process of "solidifying the family relationship". The first step of process was "affection motion" of rearing to help their daughters. The second step was "conflict" due to physical constraint and burden of child care. The third step was "acceptance" based on compensation and support and the fourth step was "development" in search of their ego. The last step was "integration" of family relationship. Conclusion: This study provided basic data for appropriate nursing intervention to grandmother to care for their grandchildren according to the five steps of grandmother's child care experience process.

• Physical Therapy Korea
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• v.24 no.3
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• pp.30-39
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• 2017

Background: Scapular posterior tilt (SPT) is important in the prevention of abnormal scapular movement and pain during elevation of the arm. However, previous studies have overlooked increased upper trapezius (UT) muscle activity interrupting the normal force couple of scapular motion and compensation of levator scapulae (LS) muscle activated simultaneously with UT during SPT exercise. Objects: The purpose of this study was to compare the effects of modified SPT with depression exercise versus SPT exercise on serratus anterior (SA), lower trapezius (LT), UT, and LS muscle activities and the clavicular tilt angle, in subjects with rounded shoulder posture (RSP) and myofascial pain in the UT muscle region. Methods: Eighteen subjects with RSP were recruited and randomly allocated to 2 groups; 9 in the SPT group and 9 in the SPT with depression group. All subjects met the specific RSP criteria and had myofascial pain of UT region. Depending on the allocated group, subjects performed the assigned SPT exercise and EMG data were recorded during the each exercise. Clavicular tilt angle was defined as the angle between the line joining the medial and lateral end of the clavicle and a horizontal line. Results: The SA muscle activity was significantly greater in SPT with depression than with SPT exercise (p<.05). The UT, LS muscle activity and the clavicular tilt angle was significantly lower in SPT with depression than with SPT exercise (p<.05). Conclusion: These findings were insightful because the potential risk of pain from overactivation of the UT and LS was considered, in contrast with SPT exercise. SPT with depression exercise can be implemented as an effective method to facilitate scapular muscle activity for stability and to prevent myofascial pain in the neck and shoulder.