• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1805-1810
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• 1991

This paper derives the upper and the lower bound of the mean cycle time and the mean service time of the class 6 and the class 4, within which the minimum utilization constrain of the class 4 is guaranteed. Also, derived are conditions under which the token bus network is stable or unstable. These bounds and stable conditions are represented in terms of the high priority token hold time, the token rotation time and the arrival rate and the total station number etc. This paper suggest a parameter tuning algorithm in a partially symmetric token bus network with two classes, which maximizes the token rotation time for a suitable high priority token hold time and at the same time meets the stability condition of the network, the real time constraint and the minimum utilization constraint of the class 4.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1944-1947
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• 2005

In this paper, the control of a prosthetic arm using the flex sensor signal is described. The flex sensors are attached to the biceps and triceps brchii muscle. The signals are passed a differential amplifier and noise filter. And then the signals are converted to digital data by PCI 6036E ADC. From the data, position and velocity of arm joint are obtained. Also motion of the forearm - flexion and extension, the pronation and supination are abstracted from the data by proposed algorithm. A two D.O.F arm with RC servo-motor is designed for experiment. The arm length is 200 mm, weight is 4.5 N. The rotation angle of elbow joint is $120^{\circ}$. Also the rotation angle of the wrist is $180^{\circ}$. Through the experiment, we verified the possibility of the prosthetic arm control using the flex sensor signal. We will try to improve the control accuracy of the prosthetic arm continuously.

• Journal of the Korea Institute of Military Science and Technology
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• v.4 no.1
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• pp.52-61
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• 2001

The purpose of this paper is to study on the control of a self-activated cable spooling system for towed away handling winch using a hydraulic servo driving unit and a cable position measurement mechanism. To design a controller of the cable spooling system, it is carried out the analysis of the hydraulic servo system and derived the relationship of a parameters through the control theory. Also, it is derived from the control specfications using settling rotation angle and spooling safety ratio proposed to the analysis for the behavior of the system. The cable spooling system is tested and evaluated to validate the performance of the controller.

• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.235-238
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• 2003

In this study, we propose a method of digital control to drive the vibrating gyroscope using electromagnetic-force. The gyroscope requires accurate vibration control and signal processing for high performance. Conventional PLL based analog controller is not only difficult to manufacture but also weak to outer environment such as temperatures, air pressures and etc. But digital controller using DSP can consistently maintain the cylinder vibration and perform digital signal processing regardless of disturbance. DSP's PWM function was utilized to control the vibration, and rotation-detecting algorithm was developed. Finally, the controller was verified by simulation and experiment using rotation-rate table.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.987-988
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• 2008

In this paper, we propose a rotation invariant face detection method using Haar-like feature variation. Previous approaches using rectangular features can be calculated very fast. But rectangular features is weak in rotated face. Rotated Haar-like features can get high accuracy, but the performance is slow because it can't use the integral image. Our method vary Haar-like features keeping rectangular. this method makes the performance a bit slow, but gives better accuracy.

• Journal of Korean Neurosurgical Society
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• v.46 no.2
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• pp.144-151
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• 2009

Objective: To compare two testing protocols for evaluating range of motion (ROM) changes in the preloaded cadaveric spines implanted with a mobile core type Charite$^{TM}$ lumbar artificial disc. Methods: Using five human cadaveric lumbosacral spines (L2-S2), baseline ROMs were measured with a bending moment of 8 Nm for all motion modes (flexion/extension, lateral bending, and axial rotation) in intact spine. The ROM was tracked using a video-based motion-capturing system. After the Charite$^{TM}$ disc was implanted at the L4-L5 level, the measurement was repeated using two different methods: 1) loading up to 8 Nm with the compressive follower preload as in testing the intact spine (Load control protocol), 2) loading in displacement control until the total ROM of L2-S2 matches that when the intact spine was loaded under load control (Hybrid protocol). The comparison between the data of each protocol was performed. Results: The ROMs of the L4-L5 arthroplasty level were increased in all test modalities (p < 0.05 in bending and rotation) under both load and hybrid protocols. At the adjacent segments, the ROMs were increased in all modes except flexion under load control protocol. Under hybrid protocol, the adjacent segments demonstrated decreased ROMs in all modalities except extension at the inferior segment. Statistical significance between load and hybrid protocols was observed during bending and rotation at the operative and adjacent levels (p< 0.05). Conclusion: In hybrid protocol, the Charite$^{TM}$ disc provided a relatively better restoration of ROM, than in the load control protocol, reproducing clinical observations in terms of motion following surgery.

• Physical Therapy Korea
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• v.13 no.1
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• pp.24-31
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• 2006

The purpose of this study was to identify the effect of the hip internal rotation on gluteal and erector spinae muscle electromyographic (EMG) activity during treadmill walking. Eleven healthy subjects were recruited. All subjects performed treadmill walking while maintaining the hip in neutral position (condition 1) and in internal rotation (condition 2). Surface EMG activity was recorded from four muscles (gluteus maximus (GM), gluteus medius (GMED), tensor fascia latae (TFL), and erector spinae (ES)) and the hip internal rotation angle was measured using a three dimensional motion analysis system. The gait cycle was determined with two foot switches, and stance phase was normalized as 100% stance phase (SP) for each condition using the MatLab 7.0 program. The normalized EMG activities according to the hip rotation (neutral or internal rotation) were compared using a paired t-test. During the entire SP of treadmill walking, the EMG activities of GM in condition 1 were significantly greater than in condition 2 (p<.05). The EMG activities of TFL and ES in condition 2 were significantly greater than in condition 1 (p<.05). The EMG activities of the GMED in condition 1 were significantly greater than in condition 1 (p>.05) except for 80~100% SP. Further studies need randomized control trials regarding the effect of hip internal rotation on the hip and lumbar spine muscle activity. Kinetic variables during gait or going up and down stairs are also needed.

• The Korean Journal of Pesticide Science
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• v.14 no.4
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• pp.473-477
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• 2010

Cucumber green mottle mosaic virus (CGMMV) is one of major plant viruses infecting cucurbitaceous crops via soil or infected seeds. This study investigate ecology of infection of CGMMV in soil, and control tactics of this virus with soil hygiene and crop rotation. This virus was survival to 50% in soil without host plants for 17 months and had high vitality in debris of infected plant over 1 year. Infection rate of CGMMV was 1.0~3.6% in control soil and 12~36% in soil transplanted with wounded root of watermelon. It showed that wounded root may affect severity of soil infection. Rotation between rice and watermelon caused dramatical reduction from 76.8% in repeated cultivation to 7.3% of progeny infection by CGMMV. Therefore, it is suggested that crop rotation be effective for control of CGMMV.

• The Journal of Korean Physical Therapy
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• v.27 no.3
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• pp.159-163
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• 2015

Purpose: This study aimed to determine the interaction among the neck, trunk, and lower extremities on the non-paretic side in head rotation along with non-paretic-side weight shifting of stroke patients. To compare stroke patients' ability to control posture through muscle activity variation related to pertubation during head rotation along with the non-paretic limb. Methods: We tested 15 hemiplegic patients and 15 normal individuals. Each group's muscle activity was measured by electromyography in neutral head position and head rotation position. We compared each group's resu lt based on measured values in patients' non-paretic neck muscles, trunk muscles, and lower limbs muscles activation. Results: The study showed that muscle activity increased in the sternocleidomastoid muscle (102.26%, 53.00%), splenius capitis muscle (97.93%, 54.93%), erector spinae muscle (241.00%, 127.60%), external oblique abdominal muscle (256.66%, 152.00%), and internal oblique abdominal muscle (252.80%, 152.6%), peroneus longus muscle (117.53%, 137.13%) and gastrocnemius muscle (119.06%, 137.20%), while the results for the sternocleidomastoid muscle, splenius capitis muscle, erector spinae muscle, external oblique abdominal muscle, internal oblique abdominal muscle, peroneus longus muscle, and gastrocnemius muscle showed a statistically significant difference (p<0.05). Conclusion: It is hard for stroke patients to engage in normal movement control under suggested conditions because of the insufficient movement against gravity on the stroke patient's non-paretic side and impaired cooperative patterns. To solve these problems, patients need their bodies to improve through effective movement, resulting in advanced control of their effective and functional activity.

• Journal of the Korea Computer Graphics Society
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• v.16 no.4
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• pp.41-50
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• 2010

We present a new technique for multilevel editing of hierarchical B-spline curves. At each level, control points of a displacement function are expressed in the rotation minimizing frames (RMFs) [1] which are computed on nodal points of the curve at previous level. When the curve is edited at previous level, the corresponding RMFs are updated and the control points of the displacement function at current level are applied to the new RMFs, which maintains the relative details of the curve at current level to those of previous level. We demonstrate the effectiveness and robustness of the proposed technique using several experimental results.