• The Journal of Korean Physical Therapy
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• 제14권4호
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• pp.1-19
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• 2002

The purpose of this study is to identify influence that eye movement have an effect on postural control and balance performance by plegia side of the impaired patients of central nervous system. Subjects are patients with the impairment of central nervous system and experimental and control groups are forty people and thirty people seperatively, Total subjects were selected to seventy persons, but twelve persons of experimental group quit during the experimental periods and eight persons of control group did not measure after exercise. Therefore, twenty eight persons of experimental group and twenty two persons of control group were selected in this study and experimental group peformed eye movement for eight weeks according to the exercise program of this study. The measurement of dependent variable is right static balance, left static balance, bilateral static balance, and bilateral dynamic balance before exercise and after eighth week of exercise, examiner again measured and analyzed the results. The results were as follows: 1. As the result of comparing balance performance ability after test of the experimental and control group with right hemiplegia and control group, all of static balance performance ability of right side (p < 0.01), static balance performance ability of left side (p < 0.01), static balance performance ability of bilateral side(p < 0.01), dynamic balance performance ability of bilateral side(p < 0.05) of experimental group were statistically greater improved than those of the control group. 2. As the result of comparing balance performance ability after test of the experimental and control group with left hemiplegia and control group, all of static balance performance ability of right side (p < 0.01), static balance performance ability of left side (p < 0.01), static balance performance ability of bilateral side(p < 0.05), dynamic balance performance ability of bilateral side(p < 0.05) of experimental group were statistically greater improved than those of the control group.

• 제어로봇시스템학회논문지
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• 제13권11호
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• pp.1099-1105
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• 2007

In this paper, modified two-port time-domain passivity approach is proposed for stable bilateral control of teleoperators under time-varying communication delay. We separate input and output energy at each port of a bilateral controller, and propose a sufficient condition for satisfying the passivity of the bilateral controller including time-delay. Output energy at the master port should be less than the transmitted input energy from the slave port with time-delay, and output energy at the slave port should be less than the transmitted input energy from the master port with time-delay. For satisfying above two conditions, two passivity controllers are attached at each port of the bilateral controller. A packet reflector with wireless internet connection is used to introduce serious time-varying communication delay of teleoperators. Average amount of time-delay was about 190(msec) for round trip, and varying between 175(msec) and 275(msec). Moreover some data packet was lost during the communication due to UDP data communication. Even under the serious time-varying delay and packet loss communication condition, the proposed approach can achieve stable teleoperation in free motion and hard contact as well.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2009년도 정보 및 제어 심포지움 논문집
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• pp.97-99
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• 2009

Bilateral teleoperation systems, connected to computer networks such as Internet have to deal with the time delay varying depending on factors such as congestion, bandwidth or distance. And the entire system is easy to become unstable due to irregular time delay. Passivity concept has been using as a framework to solve the stability problem in bilateral control of teleoperation. Acontrol scheme for teleoperation systems with varying time delay is proposed based on a passivity concept is proposed in this paper. One approach makinguse of the characteristic impedances is proposed to achieve a passive control. Since passive control does not mean that the system performance will be acceptable, another transmission scheme which focuses on both the passive feature and the acceptable performance is configured for varying time delay in this paper. The tracking performance has been proved through the computer simulation for varying time delay bilateral teleoperation system using Matlab Simulink.

• 대한치과의사협회지
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• 제11권1호
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• pp.53-57
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• 1973

The swallowing threshold of 40 subjects with bilateral missing of molars was tested. The results were as follows : 1) The swallowing threshold of the patients with bilateral missing of molars was higher than that of the normal control subjects. 2) The swallowing threshold of the patients with bilateral missing of molars was higher than that of the full denture wearer. 3) The swallowing threshold of the patients with bilateral missing of molars was different according to the quality and quantity of the test food.

• 제어로봇시스템학회논문지
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• 제6권7호
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• pp.578-585
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• 2000

This paper presents a robust and systematic bilateral controller design method for a teleoperation of an underwater manipulator. Disturbance observer is used as a local controller of the master and underwater slave manipulator to set up the teleoperation system as a nominal model by compensating coupled nonlinear terms model uncertainties and external disturbances in the water. Using the linearized master/slave model a $H_{\infty}$ optimal control scheme is applied to systematically construct a force reflecting bilateral controller.

• 전자공학회논문지SC
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• 제46권1호
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• pp.22-27
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• 2009

인터넷과 같은 네트워크 시스템에서 네트워크 혼잡, 대역폭, 거리에 따라 발생하는 시변 시간지연을 해결하는 것은 양방향 원격제어 시스템을 설계할 때 해결해야할 문제이다. 불규칙적인 시간 지연은 전체 시스템의 성능을 저하시키거나 불안정하게 만들 수 있기 때문이다. 이러한 안정성 문제를 해결하기 위해 양방향 원격 제어 시스템에서 수동성 이론이 사용되어져 왔다. 본 논문에서는 시간 지연의 변화율에 따라 전송 제어기에 시변 이득을 적용하여 수동성을 확보할 수 있는 알고리즘을 제안하였다. 그리고 시뮬레이션을 통해 제안한 시스템의 성능 결과를 보였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2414-2416
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• 2001

When a heavy-duty power manipulator with high reduction ratio joints is used as telemanipulator in teleoperated systems, its control inputs are frequently saturated resulting in deteriorated stability and poor position tracking performance. This paper proposes a bilateral control algorithm for 3-DOF heavy-duty power manipulators, which compensates for saturation. The proposed bilateral control algorithm provides precise position control performance regardless of saturation.

• The Journal of Korean Physical Therapy
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• 제34권2호
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• pp.57-62
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• 2022

Purpose: The purpose of this study was to determine the effects of bilateral visual feedback training with visual targets on the postural balance and fall efficacy of stroke patients with hemiparesis. Methods: A total of 24 stroke patients with hemiparesis were randomly assigned to either a bilateral visual feedback training (BVFT, n=8) group, unilateral visual feedback training (UVFT, n=8) group, or a control group (n=8). The BVFT and UVFT groups performed weight-bearing training on the bilateral (less-affected and affected side) or unilateral side (affected side) with visual feedback using visual targets. The control group performed squat training without visual feedback using visual targets. The training program was conducted in the form of 3 sets a day, 3 times a week, for 4 weeks. The participants were evaluated using the Berg balance scale (BBS), lateral reaching test (LRT), timed up and go test (TUG), and the activities-specific balance confidence scale (ABC). Results: In the intra-group comparison after the intervention, the BVFT group showed a significant difference in the BBS, TUG, affected and less-affected side LRT, and ABC (p<0.05). The UVFT group showed a significant difference in the BBS and ABC (p<0.05). In the inter-group comparison after the intervention, the BVFT group showed significant improvements in their BBS, affected side LRT, and TUG, when compared to the control group (p<0.05). Conclusion: These findings show that bilateral visual feedback training with visual targets during bilateral weight-bearing exercises can improve the postural balance function in stroke patients.

• Journal of Information Processing Systems
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• 제12권4호
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• pp.631-643
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• 2016

Due to the block-based discrete cosine transform (BDCT), JPEG compressed images usually exhibit blocking artifacts. When the bit rates are very low, blocking artifacts will seriously affect the image's visual quality. A bilateral filter has the features for edge-preserving when it smooths images, so we propose an adaptive-weighted bilateral filter based on the features. In this paper, an image-deblocking scheme using this kind of adaptive-weighted bilateral filter is proposed to remove and reduce blocking artifacts. Two parameters of the proposed adaptive-weighted bilateral filter are adaptive-weighted so that it can avoid over-blurring unsmooth regions while eliminating blocking artifacts in smooth regions. This is achieved in two aspects: by using local entropy to control the level of filtering of each single pixel point within the image, and by using an improved blind image quality assessment (BIQA) to control the strength of filtering different images whose blocking artifacts are different. It is proved by our experimental results that our proposed image-deblocking scheme provides good performance on eliminating blocking artifacts and can avoid the over-blurring of unsmooth regions.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(5)
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• pp.35-38
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• 2000

Since the telemanipulator consisting of high reduction ratio gear joints has a slow dynamics comparing with the master manipulator, its control signal is likely to be saturated resulting in poor tracking performance and deteriorated stability. This paper proposes a bilateral control scheme of a telemanipulator having high reduction ratio, which can compensate the control input saturation. The experimental results show that the proposed control scheme has excellent performances.