• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.172-175
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• 2016

본 논문은 손목에 부착된 단일 3축 가속도 센서를 이용하여 사용자 움직임 기반의 휴식, 걷기, 달리기(느린속도, 빠른속도)를 분류하는 방법에 관한 연구이다. 초당 32회 표본 값의 가속도 정보에서 특징 신호인 평균, 표준편차를 산출하고 사용자의 행동상태를 4가지 상태로 분류한다. 분류 기준이 모호한 상태전이 신호에 대해 6가지 상태로 분류하여 구해진 총 10개의 행동상태 정보를 2차원 평면에 사영하고 최종적으로 K-means 군집화 기법을 적용하여 사용자의 행동상태를 4가지 상태로 분류한다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.605-610
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• 1994

Optimal design of fault-tolerant, spatial type maniplators is treated in this paper. Design objective is to guarantte three degree-of-freedom translational motions in the task space, upon failure of one arbitrary joint of 4 degree-of -freedom manipulators. Realizing the nonfault-tolerant characteristics of current, wrist-type industrial manipulators, several 4 degree-of-freedom redundant structures with one joint redundancy are suggested as the fault-tolerant spatial -type manipulators. Fault-tolerant charactersitics are investigated basedon the analysis of the self-motion and the null-space elements, of a redundant manipulator. Finally, in order to maximize the fault-tolerant capability,optimal design is performed for a spatial-type manipulator with respect to the global isotropic index, and the performance enhancement of the optimized case is shown by simulation.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.51
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• pp.109-116
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• 1999

Most of carrying works have been performed in almost all production process, conveyer objects, machine equipment and work method. Then, they are made by unfitted design which doesn't consider physical condition of workers. So, it causes them to bring about forceful motion. This study investigated the back power for what difference between lumbar bending angle and back power by selecting 21 male aged 22∼30 years old. Lumbar angle were shared each 30, 60, 90 degrees and measured. The results of this study was that as lumbar angle was increasing, back power was decreased and were very significant differences for angles respectively. Besides. sample correlation coefficients were calculated in order to analyze the relationship between back power, anthropometric dimensions and grip strength. Back power was correlated with weight, arm length, hand length, breadth of palm, breadth of lower arm, breadth of wrist and left-right grip strength.

• The Journal of Korea Robotics Society
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• v.17 no.2
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• pp.164-171
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• 2022

Recently, interest of a dual arm robot which can replace humans is increasing in order to improve the working environment and solve the labor shortage. Various studies related with design and analysis of dual-arm robots have been conducted because dual arm robots can have various kinematic configurations according to the objective task. It is necessary to evaluate the work performance according to various kinematic structures of the dual arm robot to maximize its effectiveness. In the paper, the performance analysis is studied according to the shoulder configuration and the wrist configuration of the dual-arm robot by using main performance indices such as manipulability, condition number, and minimum singular value by assigning proper weight values to each objective motion. Performance analysis for the robotic assembly process is effectively carried out for each representative dual arm robot configuration.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.4
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• pp.97-108
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• 1996

Optimal design of fault-tolerant, spatial type redundant manipulators is treated in this paper. Design objective is to guarantte three degree-of -freedom translational motions in the task space, upon failure of one arbitrary joint of 4 degree-of-freedom manipulators. Noticing the nonfault-tolerant characteristics of current, wrist-type industrial manipulators, five different fault-tolerant spatial-type manipulators which have 4 degree-of-freedom structures with one joint redundancy are suggested. Faault-tolerant character-sitics of two redundant manipulators anr investigated based on the analysis of the self-motion and the null-space elements. Finally, in order to maximize the fault-tolerant capability, optimal design is performed for a spatial-type manipulator with respect to the global isotropic index, and the performance enhancement of the optimized case is shown by simulation.

• The Journal of Korean Physical Therapy
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• v.20 no.3
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• pp.45-51
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• 2008

Purpose: We evaluated the physical stress and pain to the musculoskeletal system of a dental practitioner when engaging in a dental scaling training exercise to prevent the development of musculoskeletal injuries. Methods: The 18 female (average age: 21$\pm$1 years) subjects were voluntarily picked from a group of juniors who have completed a one-and-a-half year training course that includes training exercises on the dentiform and on live subjects (other trainees). The test is done by measuring pain, activity, grip strength, and finger dexterity for each subject's hand and wrist. Before the test all subjects were confirmed to be right-handed and were informed of the study and its objective. Measuring was done before and after each subject performed dental scaling for one hour using the scaler and the curet. Results: Pain levels increased for both hand and shoulders, but hand pain was often greater than shoulder pain. Grip strength significantly declined in the right hand but not the left. For joint mobility, the flexion and the extension for the shoulder joint did not change; but the range of motion for both wrist joints significantly increased. For the dexterity test, both hands showed increased dexterity after the exercise. Conclusion: Dental scaling can affect the shoulders and wrists/hands. Therefore, a musculoskeletal injury prevention program for dental practitioners, which may include encouraging them to assume correct body posture when at work, must be sought. This study evaluated only the shoulders, wrists, and hands; but future studies should include areas such as the cervical area, the back, and the lower limbs.

• Physical Therapy Korea
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• v.18 no.2
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• pp.67-75
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• 2011

The purpose of this study was to investigate the effects of virtual reality (VR) therapy with compensation inhibition and feedback (CIF) on upper extremity function in chronic stroke patients. Seven chronic stroke patients participated in this study, which was a randomized controlled trial with a crossover design. Self upper extremity exercise, conservative VR therapy, and VR therapy with CIF were performed for one hour per session, 5 times per week, over a 3 week period. The main outcome measures involved range of motion (ROM) including shoulder, elbow, and wrist joints, a Manual Function Test (MFT), and a Motor Activity Log (MAL). Data were calculated as posttest and pretest changes in every session and were analyzed using Friedman and Wilcoxon signed-rank tests at p<.05. The results were as follows: 1) Statistically significant increase in ROM measurements of shoulder and elbow joints were seen with VR therapy with CIF compared to VR therapy and self upper extremity exercise (p<.05), whereas no significant increasing was noted for the wrist joint (p>.05). 2) Statistically significant increase in the MFT was seen with VR therapy with CIF compared with VR therapy and self upper extremity exercise (p<.05). 3) VR therapy with CIF also resulted in statistically significant increase in both activity of use (AOU) (p<.05) and quality of movement (QOM) (p<.05) on the MAL test when compared with VR therapy and self upper extremity exercise, respectively. In conclusion, VR therapy with CIF was more effective than conservative VR therapy and self upper extremity exercise in improving the upper extremity function in hemiplegic patients with chronic stroke.

• Journal of Korean society of Dental Hygiene
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• v.4 no.2
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• pp.225-236
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• 2004

It has been suggested in research results thai dental hygienists have high risk of carpal tunnel syndrome, mainly caused by the repeated motion of extensor and flexor or the use of vibration tools, compared to other occupations. To find out the situation of the carpal tunnel syndrome of dental hygienists, who are exposed to work-related musculoskeletal disorders, this study used 132 questionnaires given on May 22, 2004, the period of continuing education of the first half year in the Gwangju Jeonnam area, and obtained the following results. 1. Subjects worked at a dental ciinic(32.6%), a hospital(31.8%), and a public health center(35.6%). Age by work was under 24 in a clinic(17.4%) and a hospital(15.9%), and over 30 in a public health center(35.6%). 2. In practice conducted over one time a day, a scaling accounted for 90.7% in a doctor's office; 595% in a hospital; and 3.0% in a public health center, suggesting significant difference(p<0.01). Pit and fissure sealant accounted for 53.5% in a clinic; 53.2% in a hospital; and 95% in a public health center, also suggesting significant difference(p0.01). 3. Symptoms of carpal tunnel syndrome appeared in a wrist(12.1%), a right hand(14.4%), and a left hand(5.3%). 4. In case of temporary crown practice, symptoms appeared in a wrist(22.0%), a right hand(14.0%), and a left hand(4.0%), suggesting significant difference(p<0.01). The above results showed that 12.1% of dental hygienists was exposed to carpal tunnel syndrome. Thus, it is considered very important that dental hygienists should be given education of the danger of continuous work in certain motions and prevention education of improving repeated position, and make efforts to reinforce self-control ability.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.6 no.1
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• pp.1-8
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• 2012

Estimating algorithm of physical activity energy expenditure was implemented by using a tri-axial accelerometer motion detector of the SVM(Signal Vector Magnitude) of 3-axis(x, y, z). A total of 33 participants(15 males and 18 females) that performed walking and running on treadmill at 2 ~ 11 km/h speeds(each stage increase 1km/h). Algorithm for energy expenditure of physical activities were implemented with $VO_2$ consumption and SVM correlation between the data. Algorithm consists of three kinds and hip, wrist, waist and hip can be used to apply.

• Archives of Reconstructive Microsurgery
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• v.16 no.2
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• pp.100-107
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• 2007

Treatment of giant cell tumor of distal radius can be treated in several ways according to the aggressiveness of the tumor. But the management of giant cell tumor involving juxta-articular portion has always been a difficult problem. In some giant cell tumors with bony destruction, a wide segmental resection may be needed for preventing to recur. But a main problem is preserving of bony continuity in bony defect as well as preservation of joint function. We have attempted to overcome these problems by using a microvascular technique to transfer the fibula with peroneal vascular pedicle or anterior tibial vessel as living bone graft. From April 1984 to July 2005, we performed the reconstruction of wide bone defect after segmental resection of giant cell tumor in 14 cases, using Vascularized Fibular Graft, which occur at the distal radius. VFG with peroneal vascular pedicle was in 8 cases and anterior tibial vessel was 6 cases. Recipient artery was radial artery in all cases. Method of connection was end to end anastomosis in 11 cases, and end to side in 3 cases. An average follow-up was 6 years 6 months, average bone defect after wide segmental resection of lesion was 6.8 cm. All cases revealed good bony union in average 6.5 months, and we got the wide range of motion of wrist joint without recurrence and serious complications. Grafted bone was all alive. In functional analysis, there was good in 7 cases, fair in 4 cases and bad in 1 case. Pain was decreased in all cases but there was nearly normal joint in only 4 cases. Vascularized fibular graft around wrist joint provided good functional restoration without local recurrence.