• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.12
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• pp.1925-1930
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• 2010

For high-speed/high-accuracy position control of a gantry-moving-type linear motor, we propose a nonlinear adaptive controller including a synchronization algorithm. Linear motors are easily affected by force ripple, friction, and parameter variations because there is no mechanical transmission to reduce the effects of model uncertainties and external disturbances. Synchronization error is also caused by skew motion, model uncertainties, and force disturbance on each axis. Nonlinear effects such as friction and ripple force are estimated and compensated for. The synchronization algorithm is used to reduce the synchronous error of the two side pillars. The performance of the controller is evaluated via computer simulations.

• Journal of Korean Physical Therapy Science
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• v.12 no.4
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• pp.25-31
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• 2005

이 사례연구는 2002년 10월 15일 칼에 의한 좌상으로 경추 3-4번의 불완전 척수손상을 입은 25세의 남자 환자가 최초 병원에서 2002년 12월 한달 간의 치료를 마친 후, 2003년 1월 3일부터 4월 28일까지 태릉에 위치한 N 재활센터에서 주 5회 2시간의 자세조절 훈련, 심폐지구력 훈련, 웨이트 훈련, 스포츠(축구, 소프트 볼), 여가활동(등산)의 프로그램을 적용하여 척추손상 환자의 사회적응을 돕기위한 재활 프로그램의 다양화를 꾀하기 위한 기초 선행 작업으로 시작되었다. 신체능력을 평가하기 위한 측정도구는 관절가동범위(Range of Motion), 수동근력검사(Muscle Manual Test), 경직(Spasticity), 신체체력(Physical Fitness), 발란스(Balance: one leg stand), 상대적인 등속성 하지근력(Isokinetic Muscle Strength) 그리고 신체조성(Body Composition)로 하였다. 재활기간을 통해 처음 시작 일자에서 45일 간격으로 3차례의 측정을(1월 3일부터 4월 28일까지 실시하였다) 실시하였다. 최초 환자의 상태는 부분적으로 일상생활의 도움을 받아야 하는 상태로 동작을 시작하려 할 때 경직이 발생되어 옷을 입고 벗기, 신발 신고 벗기, 운전, 식사, 보행과 계단보행, 경사보행에서 보조자의 도움이 필요했으며, 작은 물건 잡기와 글씨쓰기, 타이핑 작업은 불가능 한 상태였다. 또한 스포츠 활동과 여가활동 역시 불가능 한 상태였다. 3달 15일간의 기간 동안 환자는 복학을 준비하기 위해 적극적으로 치료에 임했으며, 결과는 다음과 같았다. 신체조성은 재활 훈련을 통해 체중, 체지방율(%), 복부지방율(WHR)의 많은 감소를 가져왔다. 경직을 측정하는 Ashworth Scale은 정상에 가깝게 감소하였다. 관절가동범위는 고관절, 무릎, 발목에서 모두 증가하였다. 수동근력검사(0-9)는 많은 향상을 가져왔다. 신체체력능력 항목에서 근지구력의 윗몸일으키기와 팔굽히기, 악근력, 유연성으로 앉아 체간 숙이기, 민첩성으로 사이드 스텝, 순발력의 서전트는 모두 크게 향상되었다. 환자의 일상능력에서도 옷을 입고 벗기, 신발 신고 벗기, 운전, 식사, 보행과 계단보행, 경사보행에서 보조자의 도움이 필요없었으며, 타이핑 작업은 5손가락을 모두 사용하지는 않았지만, 1분에 80타로 큰 향상을 가져왔다. 또한 축구와 소프트볼, 등산을 달에 1회 정도 실시하여 약간의 도움만으로 가능하게 되었다.

• The Journal of the Convergence on Culture Technology
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• v.6 no.1
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• pp.23-29
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• 2020

Since the movements of a machine are driven by a certain principle, there is a fundamental principle that governs the movement of the machine, no matter how complex and diverse it may be. Autonomous movements are a way to avoid repetition, to approach more humane and more natural factors. That's all the more so when it comes to original movements, not cloning. So now, the dynamics of the machine are more multi-sensory by human participation. It is challenging the potential to be expressed and is gradually expanding its sphere of expression in the boundaries of fact and cloning. Theo Jansen's works have changed from period to period to adapt to different circumstances, indicating that his decades-long work has continued to evolve from early to present. The evolution's focus, among other things, can be seen as having the same source of circular motion and horizontal reciprocating motion, which are repeated from the principle of organic coupling between the parts that make up the object.

• Journal of Dental Rehabilitation and Applied Science
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• v.17 no.3
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• pp.189-193
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• 2001

교합조정은 비가역적인 술식이므로 예방적인 목적으로 사용하는 것은 바람직하지 않으며 환자가 증상을 호소하거나 환자의 구강검사시 교합간섭으로 인한 증상이 확인된 경우라도 자연치에서의 교합조정술은 반드시 신중을 기해야 한다. 교합조정술을 시행하기 전에 먼저 하악의 위치가 안정되어야 한다는 것을 명심하고 이를 위해 치과의사는 하악의 중심위에 대한 이해와 중심위로의 하악유도 방법에 대한 숙지도 필요하다. 또한 심한 악관절 장애나 통증 및 불안정한 하악의 위치를 보이는 경우 구강내 교합상이나 교합 안정장치가 선행되어야 하는 경우가 있다. 교합조정술을 시행해야 하는 치과의사 자신이 교합조정술에 대한 지식을 충분히 습득하고 있어야 하며, 교합조정술의 적응증을 분명하게 확인한 뒤 조심스럽고 정확하게 시술을 시행해야 한다. 즉, 잘못된 교합조정으로 오히려 교합간섭을 야기할 수도 있음을 명심해야 한다. 그러나 교합조정에 대해 올바로 이해하고 일반적인 교합조정의 원칙을 지켜 정확히 시행한다면 교합조정은 결코 환자에게 해를 주지 않고, 자유로운 하악운동을 가능케 하며, 교합의 안정성을 유지해 줄 것이다.

• Journal of the Korean Society of Industry Convergence
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• v.19 no.4
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• pp.167-175
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• 2016

We present a method for improving adaptability of Learning from Demonstration (LfD) strategy by combining the LfD and Particle Swarm Optimization (PSO). A trajectory generated from an LfD is modified with PSO by minimizing a fitness function that considers constraints. Finally, the final trajectory is suitable for a task and adapted for constraints. The effectiveness of the method is shown with a target reaching task with a manipulator in three-dimensional space.

• Journal of Korea Multimedia Society
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• v.6 no.1
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• pp.48-57
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• 2003

This paper describes an approach for classifying myoelectric patterns using a multilayer perceptrons (MLP's) with genetic algorithm and hidden Markov models (HMM's) hybrid classifier. Genetic Algorithms play a role of selecting Multilayer Perceptron's optimized initial connection weights by its typical global search. The dynamic aspects of EMG are important for tasks such as continuous prosthetic control or various time length EMG signal recognition, which have not been successfully mastered by the most neural approaches. It is known that the hidden Markov model (HMM) is suitable for modeling temporal patterns. In contrast, the multilayer feedforward networks are suitable for static patterns. And, a lot of investigators have shown that the HMM's to be an excellent tool for handling the dynamical problems. Considering these facts, we suggest the combination of ANN and HMM algorithms that might lead to further improved EMG recognition systems.

• Journal of Life Science
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• v.19 no.7
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• pp.968-975
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• 2009

The purpose of the present study was to examine effects of different exercise training modes (Aerobic Training, Resistance Training) on exercise specificity and transability. The tested subjects, composed of 10 healthy males without known family history or medical illnesses, were divided into two groups: Aerobic Training Group (ATG; n=5) and Resistance Training Group (RTG; n=5). An aerobic training program, based on maximum oxygen consumption rates taken during standard testing, was conducted in 60 minute sessions 3 times a week, and the Heart Rate Reserve (HRR) at 70% of maximum oxygen consumption rate was measured the using Polar. In the weight training program, based on repetition maximum rate (1-RM) taken during standard testing, the weight at 70% of such rates was measured during 60 minute sessions of 7 categories of exercise (Bench press, Leg press, Squat, Shoulder press, Arm curt Lat pull down, Triceps pull down), conducted 3 times a week. The data collected from this research were calculated to obtain average and differences compared to standards using an SPSS 11.0 statistics package. In conclusion, increase in V0$_{2max}$ and production of NO$_x$ (NO$_2$/NO$_3$), reduction of %fat, MAPwere shown effective in aerobic training and in different exercise tests, and aerobic testing within the aerobic training group (ATG) was shown to be more effective. In contrast, resistance training was shown to be more effective for the reduction of CK and LDH, and even in different tests, the resistance test within the resistance training group (RTG) showed to be more effective. Exercise specificity also significantly increased in both groups (ATG, RTG). but there was no significant difference in transability in both groups (ATG, RTG).

• Korean Journal of Applied Biomechanics
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• v.19 no.2
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• pp.205-215
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• 2009

The purpose of this study is to investigate alterations of pregnant gait by means of 3 different treads of stairs. 9 subjects(body masses; $59.41{\pm}7.49$, $64.03{\pm}6.65$, $67.26{\pm}7.58$, heights; $160.50{\pm}6.35$ ages; $31.22{\pm}2.99$; parity; $1.67{\pm}0.71$) participated in three experiments that were divided by physiological symptoms(the early(0-15 weeks), middle(16-27 weeks) and last(18-39 weeks), and walked at self-selected pace on 4 staircases 3 trials. As extending the pregnancy period, cadence was shorter but cycle time was longer more and more and the difference of maximum and minmum moments between right and left knee joint moment was smaller. With the treads of stair decent lengthening, speed and stride lengths were increased. As extending the treads of stair decent, joint moments of both feet were particular traits, hip joint was asymmetric but joint moments of knee and ankle were symmetric. These findings may account for relation between the treads of stair and moments and suggest that women may adapt their gait to maximize stability and to control gait motion for themselves in pregnant women.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.3820-3825
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• 2010

The purpose of this study was to identify the effects of acute exercise on antioxidative enzymes in noramal and obese men. The written informed consent was obtained from 16 participants of eight normally healthy persons and eight obesity ones. The baseline level of obesity was determined at 25 % of the body fat. Any subjects had no experiences in participating in exercise and did not take vitamin or mineral supplement. Blood was sampled at five minutes before exercise, at exhaustion, and after 30 minutes of recovery. All statistical analyses and description methods were computed by SPSS window 14.0. Analysis of Covariance(ANCOVA) was performed to know the differences in values between pre- and post- exercise in each group. We found that after exhaustion, the normal group showed higher erythrocyte superoxide dismutase (SOD) activity compared to the obesity group. At exhaustion, the normal group had lower HSP activity compared to the obesity group. Based on the results, an acute exercise of normally healthy people induced an up-regulation of superoxide dismutase (SOD) activity. This plays an important role in the protection of extra-cellular fluid components against peroxide-mediated damage.

• Journal of Korean Orthopaedic Sports Medicine
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• v.2 no.2
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• pp.77-81
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• 2003

Purpose: The biomechanics and kinematics of knee joint were reviewed in this article. And then the common sports injuries were presented. Anatomy and Kinetics: None of the pairs of bearing surfaces in the knee joint is exactly congruent This allows the knee six degrees of freedom of motion. Tibiofemoral Kinematics: In flexion and extension, the axis of motion is not perpendicular to the medial-lateral plane of the joint, nor is it perpendicular to the axis of longitudinal rotation. This results in coupled varus angulation and internal rotation with flexion and in valgus angulation and external rotation with extension. Patellofemoral Articulation: Loads across the patellofemoral joint are indirectly related to the angle of knee flexion and directly related to the force generated within the quadriceps mechanism. Fractures of the Patella: Nonoperative treatment is indicated if the extensor mechanism is intact and if displacement of fragment is minimal. The specific type of internal fixation depends on the fracture pattern. It is important to repair retinaculum. Acute and Recurrent Patellar Instability: The degree of dysplasia and the extent of the instability play a large part in determining the success of nonoperative treatment. Patients who experience recurrent dislocations and patients with major anatomic variations require surgery to minimize their instability. Sports Injuries in School-age Atheletes: Patellar pain in young athletes groups a number of conditions, including Idiopathic Adolescent Anterior Knee Pain, Osgood- Schlatter Disease, and Sinding-Larsen-Johansson Disease.