• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.467-472
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• 1993

산업사회의 발달과 급변하는 시장수요로 인하여 제춤의 라이프 사이클이 짧아지고, 이에 따라 제품의 소량, 다품종 생산이 절실히 요구되고 있다. 따라서 생산시스템분야에서는 상품제조의 경비를 절감하고 소비자의 다양한 욕구를 만족시키는 다품종 소량 생산체제로의 전환을 위하여 생산설비의 자동화, 고속화, 유연화를 추구하고 있다. 본 연구에서는 생산 공정에서 직접 활용 가능한 자재취급(Materal handling) 및 기구작업(tool operating)용 직교 3자유도 위치결정용 로보트를 설계, 제작하고 IBM-PC와 인터페이스하여 PID제어계를 구성하여 로보트를 제어하며 특성 실험을 통하여 성능 측정을 하고자 한다.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.407-409
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• 1996

The Direct Arm(DDA) is a SCARA typed direct drive manipulator with three degree of freedom(DOF) using the direct motor of the NSK company. In the paper, we propose a convenient interface for the SCARA-type robot which is practical to use. The proposed Visual Robot Teaching Mode using 3D graphics replaces the current teaching box. And besides this graphical teaching software can be implemented on the PC which is company used as a robot controller. This program was developed for the Windows 95 OS.

• Journal of Fashion Business
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• v.22 no.4
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• pp.93-105
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• 2018

Using FDM 3D printing, yarn shape and composition were modeled and 3D printed with PLA and TPU filaments currently used for apparel. Based on this, mechanical characteristics were measured to determine 3D printing yarn according to type of filaments in the 3D printed output and deformation and recovery characteristics due to differences in structure type. As a result of examining tensile and shear characteristics of PLA and TPU 3D printing compiles, TPU overall was measured with significantly lower stress than PLA. This is due to high elasticity of TPU's character, revealing that it has better flexibility than PLA. In addition, during deformation due to external forces, the more freedom between the head and foot parts of the loop, and the lower the force associated with each other, the more flexible it is. TPU revealed that it was easier to tension and recovery from tensile deformation than PLA, indicating potential for clothing materials using 3D printing. If high-molecular materials, such as PLA flexibility, it is likely to provide some flexibility through development of styles, including degree of freedom in modeling. Based on this, we provide basic data for developing 3D printing textures that can be satisfied with textile for apparel.

• Steel and Composite Structures
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• v.3 no.6
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• pp.403-420
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• 2003

In the paper one investigates the benefits deriving from the introduction of SMA provisions in a structure subject to dynamic excitation and vertical loads. At this purpose one considers a multi-degree-of-freedom (mdof) shear elastic-plastic frame and designs couples of super-elastic SMA tendons to be placed at critical locations of the structure. Particular attention is focused on the reduction of $P-{\Delta}$ effects.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.37.6-37
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• 2002

Omnidirectional mobile robots are capable of arbitrary motion in an arbitrary direction without changing the direction of wheels, because they can perform 3 degree-of-freedom (DOF) motion on a 2-dimensional plane. In this research, a new class of an omnidirectional mobile robot is proposed. Since it has synchronously steerable omnidirectional wheels, it is called an omnidirectional mobile robot with steerable omnidirectional wheels (OMR-SOW). It has 3 DOFs in motion and one DOF in steering. One steering DOF can function as a continuously variable transmission (CVT). CVT of the OMR-SOW increases the range of velocity ratio from the wheel velocities to robot velocity, which may improve...

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.6
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• pp.1439-1450
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• 1995

Bellows is a familiar component in piping systems as it provides a relatively simple means of absorbing thermal expansion and providing system flexibility. In routine piping flexibility analysis by finite element methods, bellows is usually considered to be straight pipe runs modified by an appropriate flexibility factor; maximum stresses are evaluated using a corresponding stress concentration factor. The aim of this study is to develop a bellows finite element, which similarly includes more complex shell type deformation patterns. This element also does not require flexibility or stress factors, but evaluates more detailed deformation and stress patterns. The proposed bellows element is a 3-D, 2-noded line element, with three degrees of freedom per node and no bending. It is formulated by including additional 'internal' degrees of freedom to account for the deformation of the bellows corrugation; specifically a quarter toroidal section of the bellows, loaded by axial force, is considered and the shell type deformation of this is include by way of an approximating trigonometric series. The stiffness of each half bellows section may be found by minimising the potential energy of the section for a chosen deformation shape function. An experiment on the flexibility is performed to verify the reliability for bellows finite element.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.5 no.3
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• pp.40-49
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• 1996

The problem related to the rotational vibration at steering wheel end of passenger cars during high speed driving is investigated. to analyze vibration of steering wheel, a steering system of passenger car is modelled in twelve degrees of freedom including backlash effect of rack and pinion gear system. The one degree of freedom system with backlash in investigated by the analytical method. Consequently the skeleton curve and the frequency response curves are computed. The steering system is analyzed by the numerical simulation using the 4th order Runge-Kutta method, the obtained results are compared with the experimental data. Also the effects of the change of rack gear tooth stiffness and backlash on the acceleration level of steering wheel are investigated. As a result, it can be found that the acceleration level of steering wheel becames lower as the rack gear tooth stiffness becames higher, and that acceleration level becames high as the magnitude of backlash between rack and pinion gear increase.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.67-68
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• 2015

This paper describes humanoid eye drive system. The eye drive system has been developed by using more than two motors for operating 2 degree-of-freedom. It needs to accomplish purpose for operating the robot eye like movement of the human eye. However it makes problems that it increases energy consumption and requires relatively large space of operating system. Thus it needs technology to minimize and have high efficiency. This paper introduces the adequacy of perviously eye drive system. And it shows research value of the spherical motor system.

• Computational Structural Engineering
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• v.6 no.3
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• pp.125-137
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• 1993

Recently, many researches are being dealt with the adaptive method for improving the accuracy of finite element solution. This paper deals with rh-methods that are the combination of r and h-method ; r-method is to relocate the nodes for the grid optimization, h-method is to divide the elements with great error into the equal shape. As a results, rh-method has the same error decrease and convergence as h-method in the same degree of freedom, but it has more exact result of finite element in the state of restraining degrees of freedom than h-method alone.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.11
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• pp.2846-2859
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• 1994

This work deals with kinematic analysis of fault-tolerant 3 degree-of-freedom spherical modules which have force redundancies in its parallel structure. The performance of a redundantly actuated four-legged module with no actuator failure, a single actuator failure, partial and half failure of dual actuator are compared to that of a three-legged module, in terms of maximum force transmission ratio, isotropic characteristics, and fault-tolerant capability. Additionally, a system with an excess number of small floating actuators is considered, and the contribution of these small actuators to the force transmission and fault-tolerant capability is evaluated. This study illustrates that the redundant actuation mode allows significant saving of input actuation effort, and also delivers a fault tolerance.