• 제목/요약/키워드: passive joint

검색결과 237건 처리시간 0.029초

Joint Channel Coding Based on Principal Component Analysis

  • Hyun, Dong-Il;Lee, Dong-Geum;Park, Young-Cheol;Youn, Dae-Hee;Seo, Jeong-Il
    • ETRI Journal
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    • 제32권5호
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    • pp.831-834
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    • 2010
  • This paper proposes a new joint channel coding algorithm based on principal component analysis. A conventional joint channel coder using passive downmixing undergoes a reduction of both the primary-to-ambient energy ratio (PAR) of the downmix signal and the panning gain ratio of the primary source. The proposed system preserves the PAR of the downmix signal by using active downmixing which reflects spatial characteristic. The proposed system also improves the accuracy of the panning gain ratio estimation. Computer simulations and subjective listening tests verify the performance of the proposed system.

병렬형 모션 시뮬레이터의 기구학적 해석과 강인 궤적추종 PID 제어기의 설계 (Kinematics and Robust PID Trajectory Tracking Control of Parallel Motion Simulator)

  • 홍성일
    • 한국군사과학기술학회지
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    • 제10권3호
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    • pp.161-172
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    • 2007
  • This article suggests an inverse kinematics analysis of a two degree of freedom spatial parallel motion simulator and design methodology of the robust PID controller. The parallel motion simulator consists of a fixed base and a moving frame connected by two serial chains, with each serial chain containing one revolute joint and two passive spherical joint. First, an inverse kinematics problems are solved in order to find the joint variable necessary to bring the end effector to track the desired trajectory. Second, an inverse optimal PID controller is proposed to track trajectories in the face of uncertainty. And the $H_{\infty}$ optimality and robust stability of the closed-loop system is acquired through the PID controller. Finally numerical results show the effectiveness of the PID controller that is designed by square/linear tuning laws.

퇴행성 슬관절염 환자에서 슬관절방(膝關節方) 1호(號)의 유효성 연구 (The Clinical Study on the Effect of Sulguanjul-bang No.1 on Osteoarthritis of Knee Joint)

  • 박민정;이경윤;박쾌환;정애경;신대희
    • Journal of Acupuncture Research
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    • 제21권3호
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    • pp.249-264
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    • 2004
  • Objective : This study is designed to find out the effects of Sulguanjul-Bang No.1 on osteoarthritis in knee joint. Methods : 45 patients with symptomatic osteoarthritis of the knee joint were enrolled in a short term 8-week open clinical trial. The 45 patients were taken Sulguanjul-bang No.1 two times a day before meals for 8 week. After 8 week treatment period, the following parameters were analyzed ; Visual analogue Scale(VAS) as first effective parameter, Lysholm index score, patient's global assessment, passive movement range of the knee joint. Results : Sulguanjul-bang No.1 treatment led to significant improvement in the pain and symptoms of osteoarthritis as determined by all efficacy measures. After 8 weeks of therapy, there was significant improvement in VAS and Lysholm index; squat, sit down and up, crepitaion, swelling. The range of motion was improved in 6 of 9 cases. The improvement in patient's global assessment was seen in 84%. Conclusion : Sulguanjul-bang No.1 was very beneficial effect in pain relief and improvement functions on osteoarthritis.

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유한요소 해석을 통한 열교 차단장치의 압축판 최적형상 설계 (The Optimal Shape Design for the Compression Joint of Thermal Bridge Breaker using FEM)

  • 신동현;김영호;김형준
    • 한국디지털건축인테리어학회논문집
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    • 제13권2호
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    • pp.17-25
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    • 2013
  • It is important to eliminate thermal bridge for achieving passive and environmental-friendly buildings. Structural members may frequently act as thermal bridges that become a conduit of energy. it is emphasized that thermal bridge breaker (TBB) system is necessary for blocking thermal bridge of the structural members. This TBB system has to maintain a performance to tensile and compressive stress which arises in member section in order to being realized structurally. Thus, it is composed with anchorage devices which obtain continuity with structural members inside building and rebar of cantilever balcony, and compression joint which resist compression stress occurring to TBB. Applying method of TBB's compression joint is designed to have high strength with comparatively small element section which can cover external load. This study carried out finite elements method based on compression experiment. Throughout the FEM analysis, this study provides information on finding optimal shape for compression joint of TBB which can suitably apply to current building balcony of Korea.

The Efficacy of Transverse Fixation and Early Exercise in the Treatment of Fourth Metacarpal Bone Fractures

  • Moon, Suk-Ho;Kim, Hak-Soo;Jung, Sung-No;Kwon, Ho
    • Archives of Plastic Surgery
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    • 제43권2호
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    • pp.189-196
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    • 2016
  • Background Several techniques have been designed to treat fifth metacarpal fractures reported to be effective. However, these methods cannot be easily applied to the fourth metacarpal due to its central anatomical position. In this study, we sought to analyze the functional outcomes of patients who underwent transverse pinning for a fourth metacarpal bone fracture. Methods A total of 21 patients were selected and their charts were retrospectively reviewed. After fracture reduction, two transverse Kirchner wires were first inserted from the fifth metacarpal to the third metacarpal transversely at the distal part of the fractured bone, and then another two wires were inserted at the proximal part of the fractured bone. The splint was removed approximately one week postoperatively and the Kirchner wires were removed four to five weeks postoperatively. Patients started active and passive exercise one week after the operation. Pain visual analog scores, total active and passive motion, and the active and passive range of motion of the metacarpophalangeal joint and grip strength were evaluated. Results Dorsal angulation improved from a preoperative value of $44.2^{\circ}$ to a postoperative value of $5.9^{\circ}$. Six weeks after surgery, functional recovery parameters, such as range of motion and grip strength, had improved to 98% of the function of the normal side. No major complication was observed. Conclusions We suggest that the transverse pinning of fourth metacarpal bone fractures is an effective treatment option that is less invasive than other procedures, easy to perform, requires no secondary surgery, minimizes joint and soft tissue injury, and allows early mobilization.

슬괵근 유연성 평가에 관한 연구 (Comparison of Six Tests for Assessing Hamstring Muscle Length)

  • 김선엽
    • 대한정형도수물리치료학회지
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    • 제5권1호
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    • pp.39-51
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    • 1999
  • Background and Purpose. Objective measurements of hamstring muscle length are needed to quantify baseline limitations and to document the effectiveness of therapeutic interventions. Several indirect clinical tests for measuring hamstring muscle length are available, but influence of their test procedure is not well documented. The purpose of this study were 1) to describe hamstring muscle length as reflected by use of six tests(active straight leg raising(ASLR), passive straight leg raising(PSLR), passive straight leg raising with the lower back flat(PSLRB), active knee extension(AKE), passive knee extension(PKE), hip joint angle(HJA). 2) to examine the correlation among the tests. Subjects, Sixty subjects(30 men. 30 women) ranging in age from 18 to 25 years(mean 20.2 years) and with no limitation hamstring flexibility and no neurological and orthopedical problems. Methods. All subjects performed six tests. A inclinometer was used to determine the end point of range of motion. HJA was measured using an inclinometer placed over the sacrum. PSLRB were tested PSLR with the low back flat and the opposite thigh slightly flexed and support on pillows. Results, A mean ASLR value of 85.9 degrees, PSLR value of 99.9 degrees, PSLRB value of 109.8 degrees, AKE value of 77.2 degrees PKE value of 83.1 degrees and HJA value of 73.0 degrees were obtained for all subjects. A dependent t-test showed significant difference between the angles of ASLR and PSLR(p<0.001). There was a significant difference between the angles of PSLR and PSLRB(p<0.001). There was a significant difference between the angles of AKE and PKE(p<0.001). The highest correlation was between PSLR and PSLRB(r=0.915, p<0.001). All SLR tests were significants related(p<0.001), as well as AKE and PKE(p<0.001). The lowest correlation was between PKE and HJA(r=0.171. p>0.05). Conclusion and Discussion. The results indicated that the hip flexion angles for ASLR, PSLR and PSLRB were a difference, and the knee extension angles for AKE and PKE were a difference.

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입원초기에 적용된 상지수동운동이 뇌혈관질환자의 환측 관절가동범위, 근력 및 상지 경직에 미치는 효과 (Effects of Passive Upper Arm Exercise on Range of Motion, Muscle Strength, and Muscle Spasticity in Hemiplegic Patients with Cerebral Vascular Disease)

  • 신동순;송라윤;신은경;서성주;박정은;한승연;정회용;류춘지
    • 대한간호학회지
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    • 제42권6호
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    • pp.783-790
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    • 2012
  • Purpose: The purpose of this study was to investigate the effects of passive upper arm exercise on range of motion, muscle strength, and muscle spasticity in hemiplegic patients with cerebral vascular disease. Methods: A quasi-experimental design with nonequivalent control group was utilized. According to inclusion criteria, 25 patients were assigned to the control group with routine care, followed by 25 to the intervention group with passive exercise for 30 minutes per session, twice a day for 2 weeks. Eighteen patients in the intervention group and 17 in the control group completed the posttest measurement, including range of motion for upper arm joints, manual muscle test, and Modified Ashworth Scale for muscle spasticity. Results: The intervention group had a significantly improved range of motion in the shoulder and wrist joints. No interaction effect was found for the elbow joint. No significant differences were found in muscle strength or muscle spasticity between the groups. Conclusion: Results of the study indicate that passive exercise safely applied for two weeks improves range of motion in joints of the upper arm in these patients. Further study with long-term follow-up is needed to verify the role of passive exercise in preventing muscle spasticity in this population.

Comparison of the Immediate Effect of the Whole-body Vibration on Proprioceptive Precision of the Knee Joint Between Barefoot and Shoe-wearing Conditions in Healthy Participants

  • Lee, Yu-bin;Hwang, Ui-jae;Kwon, Oh-yun
    • 한국전문물리치료학회지
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    • 제28권2호
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    • pp.108-116
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    • 2021
  • Background: Whole-body vibration (WBV) has been used to alleviate proprioceptive damage by musculoskeletal and neurological conditions. However, no study has determined whether wearing shoes while applying WBV can affect proprioception precision of the knee joint. Objects: This study aimed to determine the differences in the proprioceptive precision of the knee joint before and after WBV and to compare the proprioceptive precision of the knee joint between barefoot and shoe-wearing conditions. Methods: This study recruited 33 healthy participants. A passive-to-active angle reproduction test was used to measure the proprioception precision of the knee joint using an electrogoniometer, and the target angle was set to a knee flexion of 30°. Proprioception precision was calculated using the error angle (angular difference from 30°). Proprioceptive precision was measured in weight-bearing and non-weight-bearing positions before and after applying WBV for 20 minutes at 12 Hz in barefoot and shoe-wearing conditions. Mixed repeated analysis of variance was used to determine the differences in changes in the proprioceptive precision of the knee joint according to foot conditions. Results: There were significant improvements in the weight-bearing (p = 0.002) and non-weight-bearing (p < 0.001) proprioceptive precision of the knee joint after applying WBV. However, there was no significant difference in the change in proprioceptive precision of the knee joint after applying WBV between the barefoot and shoe-wearing conditions. Conclusion: WBV stimulation had an immediate effect on improving the proprioceptive precision of the knee joint. However, foot conditions (barefoot or shoe-wearing) during WBV application did not influence the proprioceptive precision of the knee joint.

나선축 개념을 이용한 팔꿈치 관절의 3차원 회전축 측정과 측정 결과를 반영한 인체 팔 모델의 개발 (Determination of the Elbow Transverse Joint Using the Helical Axis Concept and its Application to the Development of a Kinematic Arm Model)

  • 우범영;정의승;윤명환
    • 대한산업공학회지
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    • 제26권1호
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    • pp.73-80
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    • 2000
  • To determine the exact direction and location of the human joint in motion is crucial in developing a more accurate human model and producing a more fitting artificial joint. There have been several reports on the biomechanical analysis of the joint to determine the anatomy and movement of joints. However, all the previous researches were made in vitro study, that is, they investigated the passive movement of the joint from cadavers and the suggested location of the joint axis was difficult to make practical applications due to the lack of the direction of joint axis. Also, in many biomechanical models, each joint axis is assumed to lie horizontally or vertically to the adjacent links. Such an assumption causes inherent inaccuracy. In this study, the direction and location of the transverse elbow axis was obtained with respect to the global coordinate system whose origin is on the lateral epicondyle of the humerus. The suggested result based on the global coordinate system lying on the external landmark will be helpful to understand the information of the axis and to make an application. From the experiments conducted for five subjects, the direction and location of the elbow transverse joint was determined for each subject by the helical axis method. A statistical validation was also performed to confirm the result. Finally, the result was applied to develop a simple elbow model which is a part of the kinematic arm model. The simple elbow movement model was developed to validate the significance of the result and the kinematic arm model was able to describe the geometry of any complex linkage system. As a result, the errors incurred from the proposed model were significantly reduced when compared to the ones from the previous approach.

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운동화의 생체역학적 평가시 하지 회내운동의 운동학적 평가변인에 대한 상해 기준치 연구 (The Study on critical Value of Kinematical Evaluation Variables of Lower Extremity Pronation in Biomechanical Evaluation of Running Shoes)

  • 곽창수;전민주;권오복
    • 한국운동역학회지
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    • 제16권4호
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    • pp.175-187
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    • 2006
  • The purpose of this study was to find the relationship between Achilles tendon angle, angular velocity from 2D cinematography utilized to easily analyze the functions of shoes, ankle joint moment, knee joint moment, and hip joint moment from 3D cinematography utilized to predict the injury. Also, this study was to provide the optimal standard to analyze the injury related to the shoes. Subjects in this study were 30 university male students and 18 conditions (2 types of running speed, 3 of midsole hardness, 3 of midsole height) were measured using cinematography and force platform. The results were as following. 1) Hip joint abduction moment was effected by many variables such as running speed, midsole height, maximum achilles tendon angle, ground reaction force. 2) Knee joint rotational moment in running was approximately 1/10 - 1/4 times of the injury critical value and eversion moment was approximately 1/4 - 1/2 times of the injury critical value. 3) Ankle joint pronation moment in running was 1/3 - 1/2 times of the injury critical value. 4) Knee joint rotational moment was found to be irrelevant with maximum achilles tendon angle or angular velocity. 5) Pronation from running was thought to be relevant to rather eversion moment activity than rotational moment activity of knee joint. 6) Plantar flexion abductor of ankle showed significant relationship with the ground reaction force variable. 7) When the loading rate for ground reaction force in passive region increased, extensor tended to be exposed to the injury. Main variables in biomechanical analysis of shoes were impact absorption and pronation. Among these variables, pronation factor was reported to be relevant with knee injury from long duration exercise. Achilles tendon angle factor was utilized frequently to evaluate this. However, as the results of this study showed, the relationship between these variables and injury relating variable of knee moment was so important. Studies without consideration on this finding should be reconsidered and reconfirmed.