• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.478-482
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• 1996

This paper presents a new approach to the design of adaptive control system using DSPs(TMS320C50) for robotic manipulators to achieve trajectorytracking angles. Digital signal processors are used in implementing real time adaptive control algorithms to provide motion for robotic manipulators. In the proposed scheme, adapation laws are derived from the improved second stability analysis based on the indirect adaptive control theory.l The proposed control scheme is simple in structure, fast in computation, an suitable for implementation of real-time control. Moreover, this scheme does not requre an accurate dynamic modeling, nor values of manipulator paramenters and payload Performance of the adaptive controller is illustrated by exeperimental results for a SCARA robot.

• Archives of Reconstructive Microsurgery
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• 제9권1호
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• pp.56-61
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• 2000

Recommendable reconstructive surgery in the patient with thumb amputation through base of the first metacarpal bone is pollicization. Some patients who do not agree with harvest sound finger as a new thumb, we can consider other options as toe transplantation or osteoplastic thumb reconstruction for creating thumb. Toe transplantation to the thumb is effective procedure in the amputation of distal to metacarpal shaft, it is rarely indicated in the cases of proximal to base of the first metacarpal bone. We performed three cases of modified osteoplastic thumb reconstruction with free vascularized rib that combined with scapular free flap or radial forearm flap. The length of transplanted rib ranged from 7~11cm, the donor vessels are posterior intercostal artery and vein which anastomosed to radial artery. The grafted rib wrapped with additional free flap for creating new thumb. Result of that procedure was not much encouraging, aesthetic appearance and mobility of thumb were not so satisfactory but reconstructed thumb gave improvement of the hand function without sacrificing toe or other digit. That gave reasonable stability for powerful side pinch and three pod pinch and opposable thumb with normal carpo-metacarpal joint motion that can give much function to the thumb absent hand. In spite of those disadvantages, thumb reconstruction with rib transfer can be useful for patients who do not want to lose another part of the body for creating thumb in basal amputation of the thumb metacarpal.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 특별세미나 특별세션
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• pp.189-197
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• 2006

Maglev using EMS becomes unstable by unexpected big air-gap disturbance. The main causes of the unexpected air-gap disturbance are step-wise rail joint and large distance between rail splices. For the stable operation of the Maglev, the conventional system uses the threshold method, which selects one gap sensor among two gap sensors installed on the magnet to read the gap between magnet and guide rail. But the threshold method with a wide bandwidth makes the discontinuous air-gap signal at the rail joints because of the offset in air gap sensors and/or the step-wise rail joins. Further more, in the case of the one with a narrow bend-width, it makes Maglev system unstable because of frequent alternation. In this paper, a new method using fuzzy rule to reduce air-gap disturbances proposed to improve the stability of Maglev system. It treats the air-gap signal from dual gap sensors effectively to make continuous signal without air gap disturbance. Simulation and experiment results proved that the proposed scheme was effective to reduce air-gap disturbance from dual gap sensors in rail joints.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1300-1309
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• 2010

In the railway bridges, steel plate girder types are preferred due the high stability. Nevertheless, it has been pointed out that this type of bridge has problems such as, structural damages in the rail and girder seat, noise problem due to impact at the rail joint and excessive vibration. This vibration and/or deflection are mainly because insufficient stiffness of steel plate type of bridge. To resolve these problems, PC-Slab composite plate girder type which has simple process and economic cost, is proposed in this study. The static and dynamic experiment is performed by using the production of actual sized PC-Slab and abandoned steel plate girder. The object of this experiment is to verify the fact that girder stiffness increase and structural safety. The result of the experiment is used to analyze the effect of performance improvement of PC composite plate girder type. Using this method, economic rail maintainers, girder stiffness increase, and also speed/ride improvement even for existing rail could be expected by dynamic performance improvement. Additionally noise due to impact, deflection and vibration caused from long rails can be reduced.

• Steel and Composite Structures
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• 제7권2호
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• pp.161-184
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• 2007

The use of composite semi-rigid connections is not fully exploited, in spite of its great number of advantages. Composite semi-rigid connections may lead to an optimal moment distribution that will render lighter structures. Furthermore, using the appropriate semi-rigid connection design, the stability of the frames against lateral loads may entirely rely on the joint stiffness, thus avoiding bracing systems and permitting more diaphanous designs. Although modern codes, such as the Eurocode 4 (EC4), propose thorough methods of analysis they do not provide enough insight and simplicity from the design point of view. The purpose of this paper is to introduce practical and efficient methods of analysis that will facilitate the work of a structural analyst starting from the global analysis of the composite frame and ending on the final connection design. A key aspect is the definition of the stiffness and strength of the connections that will lead to an optimal moment distribution in the composite beams. Two examples are presented in order to clarify the application of the proposed methods and to demonstrate the advantages of the semi-rigid composite design with respect to the alternative pinned and rigid ones. The final aim of the paper is to stimulate and encourage the designer on the use of composite semi-rigid structures.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1461-1466
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• 2008

In the case of Posterior Cruciate Ligament (PCL), the most frequent mechanism is the dashboard injury, which is directly pressurized to the anterior of the proximal tibia in the state of the knee hyperflexion. The PCL associated ligament damage happens when the posterior injury, the varus, the valgus, the hyperextension and the severe vagus torque are out of the critical value of PCL. After the successful operation cases of Anterior Cruciate Ligament (ACL) reconstruction using the allograft were informed from 1986, a number of results kept over the maximum 10 years were reported. Unfortunately, PCL reconstruction are crowded the surgery techniques such as the graft, the tibia fixing method, the fixation device, the location of the femoral tunnel, the number of the graft bundles and PCL reconstruction to access to the stability of the normal joint is being developed. Therefore, this study is the basic research of these above facts. The current transtibial tunnel surgery using the cadaveric Achilles tendon grafts is chosen for the various PCL reconstruction. The initial extension of the Achilles tendon by the fixing device and its location under the cyclic loading, were observed.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.576-583
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• 2000

A robust position control using a sliding mode controller is adopted for the stable dynamic walking of the biped. For the biped robot that is modeled with 14 degrees of freedom rigid bodies using the method of the multibody dynamics, the joint angles for simulation are obtained by the velocity transformation matrix using the given Cartesian foot and trunk trajectories. Hertz force model and Hysteresis damping element which is used in explanation of the energy dissipation during contact with ground are used for modeling of the ground reactions during the simulation. By the obtained that forces which contains highly confused noise elements and the system modeling uncertainties of various kinds such as unmodeled dynamics and parameter inaccuracies, the biped system will be unstable. For that problems, we are adopting a nonlinear robust control using a sliding mode controller. Under the assumption that the esimation error on the unknown parameters is bounded by a given function, that controller provides a successful way to preserve stability and achieve good performance, despite the presence of strong modeling imprecisions or uncertainties.

• 한국구조물진단유지관리공학회 논문집
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• 제7권2호
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• pp.231-238
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• 2003

지진에 의해 피해를 입은 철근콘크리트 건축물을 재사용이 가능하도록 보수-보강을 실시하여 구조적으로 안전성을 확보하게 되는데 이러한 보수-보강이 부적절하게 시공되었거나, 재지진을 받아 구조내력이 크게 감소된다면 다시 보수-보강을 할 수 밖에 없다. 본 연구에서는 지진 발생시 가장 우려되는 보-기둥 접합부를 실험 대상으로 선정하여, 시험체에 1차 동적하중과 2차 동적하중을 작용시킨 후 각각 보수-보강을 실시한 다음 구조특성 및 하중속도에 따른 보강성능을 검토하여 재보수-보강의 타당성을 규명하였다.

• The Journal of Korean Physical Therapy
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• 제14권4호
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• pp.423-440
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• 2002

The purpose of this study is to investigate the conception and developmental process of stretching in sports physical therapy. This study is to find conception of stretching, feature and effect, principles and fundamental rule, consideration of enforcement and developmental process in order to use the basic material which is very helpful in the every field and the scene of sports needing stretching. Flexibility is the ability to move muscles and joints through their full ranges of motion. Flexibility is developed by stretching. About player who insufficiency of flexibility, patient and disabled person who restrict of range of motion, older adult who reduce of flexibility, promote of flexibility for upgrading stability and efficiency of body on the based of scientific principles is completed by stretching. The method of stretching has been developed with passive stretching, CR, PNF stretching, PIC stretching, MET stretching in the order. The effects that we can get through stretching are as follows : 1. Enhance physical fitness. 2. Optimize learning, practice and performance of many types of skilled movement. 3. Increase mental and physical relaxation. 4. Promote development of body awareness. 5. Reduce risk of joint sprain or muscle strain. 6. Reduce risk of back problem. 7 Reduce muscular soreness. 8. Reduce the severity of painful menstruation for female athletes. 9. Reduce muscular tension. 10. Advance recognition of body.

• 한국소음진동공학회논문집
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• 제13권1호
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• pp.10-18
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• 2003

This paper presented a design and control of a biped walking RGO(robotic gait orthosis) and its simulation. The biped walking RGO was distinguished from the other one by which had a very light-weight and a new RGO system will be made of 12-servo motors and 12-controllers. The vibration evaluation of the dynamic PLS(posterior leaf splint) on the biped walking RGO was used to access by the 3-axis accelerometer with a low frequency vibration of less than 30 Hz. The galt of the biped walking RGO depends on the constrains of mechanical kinematics and the initial posture. The stability of dynamic walking was investigated by analyzing the ZMP (zero moment point) of the biped walking RGO. It was designed according to the human wear type and was able to accomodate itself to the environments of S.C.I. Patients. The Joints of each leg were adopted with a good kinematic characteristics. To analyse joint kinematic properties. we made the strain stress analysis of the dynamic PLS and the analysis study of FEM with a dynamic PLS.