• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.04b
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• pp.218-222
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• 1993

A sliding mode controller associated with the moving sliding surface is formulate for the tip position control of a single-link flexible manipulator. After establishing the plant model which characterizes a noncollocated control system, a discontinuous control law is then constructed by restricting that velocity state variables are not available from direct sensor measurements. Using the proposed control law favorable system responses are accomplished through shortening the reaching phase without increasing maximum control torque. Furthermore, a low sensitiveness to extraneous disturbance is obtained. Computer simulations are undertaken in order to demonstrate these superior control performance characteristics to be accrued from the proposed methodology.

• Journal of the Korean Society of Industry Convergence
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• v.18 no.3
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• pp.157-166
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• 2015

In this paper, we proposed a new robust control scheme to implement stable control of robot manipulators including nonlinear perameters The proposed robust controller is composed of a nonlinear controller and linear compemsation controller. It shows a good robust performance in reaching mode which does not possess invariance property. Thus, the proposed nonlinear controller showed a good robust performance in the whole region, It was illustrated that the proposed control showed a good transient response and trajectory tracking performance for robot manipulator with four joint by experiments.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.80-82
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• 1997

A robust position control system for a BLDC motor using new sliding mode control strategy is presented. Using the new variable structure system, reaching phase problem is eliminated and transient response is largely improved by design of nonlinear sliding surface. The design of the sliding mode position controller is robust in motor parameter, load variations and disturbance. Experiment results show that the proposed approach can achieve accurate position motor tracking in face of large parameter variations and external disturbances, such as a robot arm, etc.

• PNF and Movement
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• v.15 no.1
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• pp.13-25
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• 2017

Purpose: This study investigated the coordination and contribution of body segments during functioning. Methods: The relevant literature related to body segments and function were reviewed. Results: Efficient control of function is considered with regard to a participant's ability to perform a sequence of movements in body segments, which progresses from the head to the arm, trunk, pelvis, and leg segments. Each segment performs a specific role, which environment explorer using visual information for the head, reaching and grasping for the arms, a stabilizer for the trunk, and the distribution of COM in the pelvis and leg. Conclusion: During any of the movements, the momentum generated by the proximal segments is transferred to the adjacent distal segments in an appropriate sequence. In assessing function for clinical intervention strategies, the segment coordination, segment sequence, transfer of the center of body mass, asymmetrical ratio, muscle activity, and compensatory strategies should be considered.

• The Journal of Korea Robotics Society
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• v.18 no.3
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• pp.323-329
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• 2023

This paper discusses the application of collaborative robots to the de-palletizing in IMC (Inte-grated Mail Center). The domestic courier logistics market has grown rapidly, and logistics centers are reaching critical capacity. Therefore, digital innovation based on logistics automation is necessary, and this paper looks at the factors to be considered when introducing collaborative robots and improvement measures considering the characteristics of the de-palletizing task. The benefits of introducing collaborative robots include immediate efficiency and the goal of assisting workers. The paper reviews related research and cases of collaborative robots applied to logistics centers and summarizes the results of collaborative robots introduced to actual postal logistics centers. The paper also provides a comparison of collaborative robots and industrial robots and presents four candidates for collaborative robots for logistics work. The paper also considers suction grippers to be mounted on the arm to grasp the parcel. The paper concludes by discussing the introduction of collaborative robots in the post office logistics center.

• Physical Therapy Rehabilitation Science
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• v.9 no.2
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• pp.74-81
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• 2020

Objective: To prevent low back pain, an objective evaluation tool to evaluate pelvic mobility and exercise to improve the flexibility of the lumbar region is needed. The purpose of this study was to compare the results of pelvic mobility measurements using the Wii Balance Board (WBB) and Sensbalance Therapy Cushion (STC), evaluate the usefulness of the STC as a tool for measuring pelvic mobility. Design: Cross-sectional study. Methods: Fifty healthy subjects participated in this study. The subjects performed pelvic mobility range, proprioception, reaction time and reach of the arm using the STC. The pelvic movement parameter was measured two times to determine the intra-rater reliability. To measure the correlation between lumbar muscle tension and pelvic mobility, Myovision was used to measure tension of L4, L5 level erector spinae muscle. Correlations between measured variables were checked to determine the validity of the pelvic mobility assessment tool. Results: STC showed high test-retest reliability in pelvic tilt measurement and reaching task [intraclass correlation coefficients (3,1)=0.804-0.915]. The relationship between WBB and STC showed a significant positive correlation with the pelvic tilt and reaching task (p<0.05). Posterior tilt and erector spinae activation (Lt. L5) showed a significant negative correlation (p<0.05). Left, right tilt and erector spinae activation (L5) showed a significant negative correlation (p<0.05). Conclusions: This study confirmed the advantages of the STC and found efficiency as an objective measuring device of pelvic mobility.

• The Journal of Korean Medicine
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• v.36 no.2
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• pp.1-7
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• 2015

Objectives: To report on the result of infertility treatment with Korean medicine in clinical settings. Methods: This study was single arm, retrospective observational study. Analysis of the medical records on thirty four infertile women who were treated by acupuncture, moxibustion, herbal medicine(Jokyungjongoktang-gagambang, Sutaehwan-gagambang). Pregnancy rate(PR) and Live birth rate(LBR) were analyzed as the primary outcomes. Changes of AMH, FSH, LH, $E_2$, $P_4$, endometrial thickness, fat mass, and BMI were also analyzed as the secondary outcomes. Results: A total of 34 patients were treated in the traditional Korean medical clinic. Nine patients were dropped, and 25 subjects completed the final examination at the end of this treatment schedule. Five of 25 subjects conceived during treatment, reaching 20% PR and LBR was also 20%. Except for FSH level, the results of the remaining outcome measures, including LFT, showed no significant changes. No serious adverse event has been reported. Conclusion: Although no significant changes in bio-markers were observed, complex treatment using Korean medicine has shown effectiveness on women's infertility. In addition, the safety of the treatment has been verified.

• Physical Therapy Korea
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• v.12 no.1
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• pp.1-10
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• 2005

The purpose of this study was to verify the most effective spinal stabilization exercises program by comparing the activities of muscles contributing to spinal stabilization during four types of exercises using a sling and a mat. Twenty healthy males were recruited and each subjects performed four types of exercises. Exercise 1 was performed in a quadruped position with the subjects lifting the left arm and the opposite leg on the mat. Exercise 2 was performed in a prone position while holding a sling with the right hand and the left knee was fully extended while lifting the left arm and right leg. Exercise 3 was performed in quadruped position while holding a sling with one the right hand and lifting the opposite arm and leg. In exercise 4, subjects were instructed to maintain a balance push-up position while holding slings with both hands in 10 cm forward reaching with extended elbows. Electromyographic(EMG) activities were recorded from the multifidus, external oblique, internal oblique, abdominal rectus, and erector spinalis muscles during the exercises. The EMG amplitude of each muscle was normalized to the amplitude in the maximal voluntary isometric contraction (MVIC) of each muscle. Repeated ANOVA and Bonferroni's tests were used to compare the differences in the muscle activity according to the types of exercise. The EMG amplitudes of all the muscles were significantly different according to the types of exercises (p<.05). The highest EMG activities of each muscle was as follow; multifidus was 73.38%MVIC in exercise 3, the erector spinalis was 40.03%MVIC in exercise 3, the external oblique was 135.88%MVIC in exercise 4, the internal oblique was 128.60%MVIC in exercise 4, and the rectus abdominalis was 95.24%MVIC in Exercise 4. The types of exercises showed a significant difference in composition rate of EMG amplitudes of each muscle (p<.05). EMG composition rate of the multifidus was high in exercise 1 and 3. However, EMG composition rates of the external oblique, internal oblique, and the rectus abdominals were high in exercise 2 and 4. These results showed differences in EMG activities of muscles contributing to trunk stabilization during different therapeutic exercises. Therefore, the type of exercise should be carefully selected to effectively strengthen a specific trunk stabilizer.

• 전자공학회논문지 IE
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• v.47 no.3
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• pp.19-25
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• 2010

We developed a RFID terminal to voice guide the blind who have difficulties in reaching out to the pharmaceutical information. In this work, we used RFID technology to instruct the pharmaceutical information to the blind. The voice guidance reader was made to read the RFID tag attached to the drugs and announced the pharmaceutical information matching to the tag specific ID. We had the reader to obtain the pharmaceutical information from the ezDrug site operated by Korea Food & Drug Association. The voice guidance reader was fabricated as necklace type for the easy carry, and we added mp3 player as dual uses. ARM series Cortex M3 chip was used for the reader's core chip and low power MFRC523 chipset of NXP was used to construct RFID circuit. MFRC523 chip uses low power to meet the mobile application. We used VS1003B MP3 Decoder IC to make the voice generation circuit and CC2500 chipset for the wireless communication to the pharmaceutical information server. We also developed the system that can support ISO 14443A type and ISO 14443B type so that the system can be used to extend to various RFID protocols. Utilization of this system can conveniently convey the pharmaceutical information to the blind and reduce the drug abuse.

• Journal of Chest Surgery
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• v.23 no.5
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• pp.929-935
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• 1990

Violence in our society, combined with improving transport system, resulted in increased numbers of patients with cardiac wounds reaching the hospital alive. Most patients with penetrating cardiac injury, rather than blunt injury, present with a syndrome of either hemorrhagic shock or cardiac tamponade. And they should be operated upon as soon as possible. Often the atrioventricular valves and other important cardiac structures are also damaged by the penetrating instruments or missile. Both intracardiac communications and atrioventricular fistulas may result in significant left-to-right shunts accompanied by congestive heart failure, necessitating surgical correction. Usually, retained cardiac foreign bodies, which are almost always bullets or fragments of missiles, may lie within a cardiac chamber or in the myocardium. Emboli of bullets or other missiles from distant sites to the right side of the heart are numerous enough to require attention. Recently we experienced a case with intracardiac foreign body due to penetrating cardiac injury. A 19 year-old man was admitted to our hospital due to penetrating anterior chest wound by iron segment. The roentgenogram of the chest revealed a radio-opaque metallic shadow in left lower chest around the cardiac apex, mild blunting of left costophrenic space, but no cardiomegaly. During operation the foreign body was noted to be present in the cardiac chamber by the portable C-arm fluoroscopy. But during the manipulation it moved into left inferior pulmonary vein from left ventricle by way of left atrium. So we could manage to remove it from left inferior pulmonary vein by direct approach to the vein. It was iron segment, sized 0.lcm x0.6cmx0.5cm, with sharp margins. The patient had an uneventful postoperative recovery except for chylopericardium and was discharged.