• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1709-1712
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• 2008

The trunk is inclined to the loaded side when carrying an object as one of activities of daily living. As the reaction to this behavior the human body may be inclined to his/her trunk to unloaded side. The present study investigated the biomechanical effects of weight variation for sided load carriage during walking upon joint moments and muscle torques, through the tracker agent and joint driving dynamic analysis. To perform the experiment one male was selected as subject for the study. Gait analysis was performed by using a 3D motion analysis system. Thirty nine 14mm reflective markers, according to the plug-in marker set, were attached to the subject. We used BRG.LifeMOD(Biomechanics Research Group, Inc., USA), for skeletal modeling and inverse and joint driving dynamic simulation during one gait cycle. In walking with a sided load carriage, the subject modeled held the carriage with the right hand, which weighed 0, 5, 10, 15kg, 20kg respectively. The result of this simulation showed that knee and hip in the coronal plane were inclined to the loaded side and loaded side had larger moments as the sided load carriage was increased. On the other hand thoracic and lumbar in the coronal plane had larger negative values as the sided loaded carriage was increased. The thoracic and lumbar in the transverse plane also had larger values as the sided load was increased. And the several muscles of loaded side were increased as increasing sided load. It could be concluded that human body is adopted to side loaded circumstances by showing more biologic force. These results could be very useful in analysis for delivery motion of daily life.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.266-271
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• 1992

This paper presents a new stable composite control law for the flexible joint robot manipulators, which incorporate the additional stabilizing control law with sliding property. The singularly perturbated models include inertia moments functions of the deformations of actuator. The newly defined fast controller variable is computed from the corrected reduced-order model without additional computational loads. The simulations for 2 DOF flexible joint manipulator show that the proposed schemes are more stable than conventional one, and especially effective for the manipulator with high joint-flexibilities.

• Journal of Advanced Marine Engineering and Technology
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• 제28권2호
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• pp.382-392
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• 2004

The usage of constant velocity (CV) joint is effective for motorboats on gliding regime of the motion. During transition on the gliding when angle of the CV differs from null on driving and driven composite shafts there are moments of the second order. Excitation of oscillations of the second order moments occurs when driving shafts transmits a variable torque. which generates through CV joint a lateral moment acting on the bearing. As a result of oscillations from a resonating harmonic of a shafting the harmonic with the greater or periodically varying amplitude for power condition trough transferring to nominal power 144kW. Beating conditions coincide with third mode having frequency 45.486 Hz. In that case there is high increasing of the equivalent stresses. The forming of the stiffness of the composite material is concerned to use most orientation of the layer angle in the range of $\pm$60 degrees relatively of shaft axis. Application of that angles for layer orientation gives possibility to avoid high disturbance of the shafting for motorboat transition regime.

• 한국운동역학회지
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• 제19권2호
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• pp.205-215
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• 2009

계단 하강보행에서의 임산부 낙상은 임산부와 태아에게 치명적인 영향을 미친다. 이 연구는 임신기간 중 계단의 단 너비 변화에 따른 임산부 양발 보행의 생체역학적 변화를 구명하는 것이다. 이 실험을 위하여 건강한 임산부 9명이 참가하였고 Qualisys사의 Proreflex MCU-240 카메라 7대와 Kistler사의 Type 9286AA 지면반력기 2대를 설치하여 상호 동조하여 실험하였으며 연구변인은 Visual 3D(C-motion Inc., USA)를 사용하여 인체를 모델링 한 후 산출하였다. 임신기간이 경과됨에 분당 활보장수는 감소한 반면 활보장 주기는 증가하였으며 양발의 슬관절 모멘트 차이가 작아졌다. 그리고 단너비가 넓어질수록 속력과 활보장 길이가 증가하였다. 단너비에 따른 하지 관절모멘트는 각 관절마다 고유한 패턴을 보였으며 고관절 모멘트는 주로 양발의 비대칭성 패턴을 보였고 슬관절 및 족관절은 대칭적인 패턴을 보였다. 그리고 임신기간이 경과됨에 따라 좌 우측의 최대 최소 슬관절 모멘트의 차이가 작아졌다. 이러한 결과들은 임산부가 신체변화에 적응하면서 안전성의 최대화를 위하여 자신의 고유한 보행패턴을 생성하는 자기적응화 과정을 지속적으로 유지하면서 변화한다고 할 수 있다.

• 한국운동역학회지
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• 제26권4호
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• pp.407-412
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• 2016

Objective: The aim of this study was to analyze the net joint moment and joint power of the lower extremity during squat in female patients with genu varum. Method: Eight female patients with genu varum were asked to do regular squats, and their net joint moment and joint power were compared to those of another eight female participants with straight legs. Their video recordings and ground reaction force data were analyzed to be used as a theoretical evidence of squatting effectively for female patients with genu varum. Results: Squats had a higher impact on internal knee joint rotation and ankle joint flexion moments in the genu varum group than in the straight leg group due to their weak and short hip joint muscles. Conclusion: There is a need to develop a squat movement that is appropriate for women with genu varum in order to distribute overload efficiently among the hip, knee, and ankle joints and to strengthen the muscles in a balanced way.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.879-880
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• 2008

• Journal of Electrical Engineering and information Science
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• 제1권1호
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• pp.151-155
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• 1996

This paper derives the two-dimensional probability distribution and density functions of morphological dilation and erosion of a one-dimensional memoryless source and reports numerical results for a uniform source, thus providing methodology for joint distributions for other morphological operations. The joint density functions expressed in closed forms contain the Dirac delta functions due to the joint discontinuity within the dilation and erosion. They also exhibit symmetry between these two morphological density functions of dilated and/or eroded sources, in the computation of other higher moments thereof, and in multidimensional quantization.

• 대한의용생체공학회:의공학회지
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• 제25권4호
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• pp.301-307
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• 2004

보행 중 각 관절의 모멘트를 계산하기 위한 역동역학 모델을 개발하였다. 모델은 1개의 상체와 3개의 체절로 하지를 구성하였고 3개의 병진 조인트와 12개의 회전조인트로 각 체절을 연결하고 뉴턴-오일러 방법으로 역동역학 해를 구하였다. 입력자료로서의 기구학적 사료는 3차원 동작분석 시스템에서 추출하였고 외력으로서 지면 반발력은 동기화한 힘측정판에서 구했다. 개발된 모델을 이용하여 비대칭 모델이나 질량중심의 이동을 포함한 해석 등 다양한 인체운동 해석이 가능하다.

• Structural Engineering and Mechanics
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• 제13권1호
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• pp.91-101
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• 2002

During the last several years, research activity on non-tubular bonded joints has concentrated on the effects of normal stress, bending moments and shear. Nevertheless, in certain situations, the structure may be subjected to twisting moments, so that the evaluation of its dynamic behaviour to torsional vibrations becomes of great importance even though evaluations of such loading conditions is entirely lacking in the literature. The aim of this article is to show that torsional natural frequencies of the non-tubular joint can be evaluated by determining the roots of a determinantal equation, derived by taking advantage of some analytical results obtained in a previous paper dealing with the analysis of the state of stress in the adhesive. Numerical results related to clamped-free and clamped-clamped joints complete the article.

• Journal of the Korean Data and Information Science Society
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• 제27권1호
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• pp.265-274
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• 2016

In this paper, we consider a diffusion risk process, in which, its surplus process behaves like a Brownian motion in-between adjacent epochs of claims. We assume that the claims occur following a Poisson process and their sizes are independent and exponentially distributed with the same intensity. Our main goal is to derive the exact formula of the joint moment generating function of the ruin time and the total amount of aggregated claim sizes until ruin in the diffusion risk process. We also provide a method for computing the related first and second moments using the joint moment generating function and the augmented matrix exponential function.