• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.474-479
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• 2004

This paper presents an economical solution of the control system of robot, which is widely applied to sophisticated robots. The proposed control system is built on a foundation that is combined between driver motor, PC controlled servo-motor control card, and driver software. The solution had been applied to design hardware of controlled 6-DOF (Degree Of Freedom) robot. The controlled system is used to control VML Robot (Vehicle Mechatronic Lab). Addition, because of flexibility of the solution, the controller can be suit with widely robots at used servo-moto.

• Journal of Dental Anesthesia and Pain Medicine
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• v.24 no.4
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• pp.227-243
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• 2024

This study aimed to evaluate pain assessment strategies and factors associated with outcomes after microvascular decompression for the treatment of primary trigeminal neuralgia in adults. We conducted a systematic review and meta-analysis of English, Spanish, and French literature. We searched three databases, PubMed, Ovid, and EBSCO, from 2010 to 2022 and selected studies including patients with primary trigeminal neuralgia, clear pain assessment, and pain outcomes. Population means and standard deviations were calculated. Studies that included factors associated with postoperative outcomes were included in the meta-analysis. A total of 995 studies involving 5673 patients with primary trigeminal neuralgia following microvascular decompression were included. Patients with arteries compressing the trigeminal nerve demonstrated optimal outcomes following microvascular decompression (odds ratio [OR]= 0.39; 95% confidence interval [CI] = 0.19-0.80; X² = 46.31; Dof = 15; I² = 68%; P = < 0.0001). Conversely, when comparing arterial vs venous compression of the trigeminal nerve (OR = 2.72; 95% CI = 1.16-6.38; X² = 23.23; Dof = 10; I² = 57%; P = 0.01), venous compression demonstrated poor outcomes after microvascular decompression. Additionally, when comparing single-vessel vs multiple-vessel compression (OR = 2.72; 95% CI = 1.18-6.25; X² = 21.17; Dof = 9; I² = 57%; P = 0.01), patients demonstrated unfavorable outcomes after microvascular decompression. This systematic review and meta-analysis evaluated factors associated with outcomes following microvascular decompression (MVD) for primary trigeminal neuralgia (PTN). Although MVD is an optimal treatment strategy for PTN, a gap exists in interpreting the results when considering the lack of evidence for most pain assessment strategies.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.5
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• pp.149-156
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• 1995

본 연구의 목적은 6자유도를 가진 병렬형 메니퓰레이터의 기구학적 해석을 하는데 있다. 일반적인 산업용 로봇의 구조는 링크가 직렬로 연결된 형상을 하고 있으며 이러한 형태는 넓은 작업공간의 확보와 유연성이 뛰어난 장점이 있는 반면에 각 링크의 오차가 메니퓰레이터의 끝단에서 누적되어 나타나게 되고 구동렬이 증가하게 되는 단점을 지니고 있다. 이러한 단점을 극복하기 위하여 정밀한 위치제어가 필요한 경우에는 병렬형 형태의 링크를 지닌 구조를 사용하고 있다. 병렬형 메니퓰레이터의 역기구학적 해석은 비교적 단순한 데 반하여 정기구학적 해 석은 비선형 방정식의 형태로 나타나며 해석적으로 그 해를 구하기가 쉽지 않다. 본 연구에서는 6자유도를 지닌 병렬형 메니퓰레이터의 기구학적 해석을 수행하였으며 예제를 통하여 검정하였다.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.6
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• pp.560-567
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• 2007

The objective of this research is to optimize the designing parameters of the parallel manipulator with large orientation workspace at the boundary position of the constant orientation workspace (COW). The method uses a simple genetic algorithm(SGA) while considering three different kinematic performance indices: COW and the global conditioning index(GCI) to evaluate the mechanism's dexterity for translational motion of an end-effector, and orientation workspace of two angle of Euler angles to obtain the large rotation angle of an end-effector at the boundary position of COW. Total fifteen cases divided according to the combination of the sphere radius of COW and rotation angle of orientation workspace are studied, and to decide the best model in the total optimized cases, the fuzzy inference system is used for each case's results. An optimized model is selected as a best model, which shows better kinematic performances compared to the basis of the pre-existing model.

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.260-260
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• 2017

• Journal of the Korean Society of Industry Convergence
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• v.22 no.3
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• pp.315-324
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• 2019

This paper present a novel 6-axis robotic base platform with force/moment sensing. The robotic base platform is made up of six loadcells connecting the moving plate to the fixed plate by spherical joints at the both ends of loadcells. The statics relation is derived, the robotic base platform prototype and the loadcell measurement system are developed. The force/moment calibrations in joint and Cartesian spaces are performed. The algorithm to detect external force applied at a working robot is derived, and using a 6-DOF robot mounted on the robotic base platform, force/moment measurement experiments have been performed.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.6_2
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• pp.953-959
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• 2021

In this paper, the numerical inverse kinematics analysis is presented for a collaborative robot with an offset wrist. Robot manipulators with offset wrist are widely used in industrial applications, due to many advantages over those with wrist center and those with three parallel axes such as simple mechanical design, light weight, and so on. There may not exist a closed-form solution for a robot manipulator with offset wrist. A simple numerical method is applied to solve the inverse kinematics with offset wrist. Singularity is analyzed using Jacobian matrix and the numerical inverse kinematics algorithm is implemented on the real-time controller.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.9-14
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• 2018

The function of gas springs is based on the compression of a gas. They are used in a wide variety of industries, and demand for them is increasing. Gas springs can be divided into compression and extension springs. Extension springs have not been studied much in relation to control of the piston speed, unlike compression springs. In this study, the magnitude of the piston rebound pressure was theoretically predicted by calculating the pressure loss in a double-cylinder extension gas spring. Numerical simulations of the piston behavior were carried out for small and large amounts of friction between the piston and the cylinder. FLUENT was used for the simulation with a 6-DOF model and UDF to simulate the behavior of the piston. The calculation regions of the front and rear of the piston were separated, and different types of grids were generated in the regions to implement a dynamic mesh using only a layering method. The results show that the piston returns with the target speed in both cases. However, the patterns of the piston behavior reaching the final speed are different.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.296-301
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• 2005

This paper describes the kinematics, dynamics and control of a 6-DOF shaking table with a bell crank structure, which converts the direction of reciprocating movements. In this shaking table, the bell crank mechanism is used to reduce the amount of space needed to install the shaking table and create horizontal displacement of the platform. In kinematics, joint design is performed using $Gr{\ddot{u}}bler's$ formula. The inverse kinematics of the shaking table is discussed. The derivation of the Jacobian matrix is presented to evaluate singularity conditions. Considering the maximum stroke of the hydraulic actuator, collision between links and singularity, workspace is computed. In dynamics, computations are based on the Newton-Euler formulation. To derive parallel algorithms, each of the contact forces is decomposed into one acting in the direction of the leg and the other acting in the plane orthogonal to the direction of the leg. Applying the Newton-Euler approach, the solution of inverse dynamics is almost completely parallel. Only one of the steps-the application of the Newton-Euler equations to the platform-must be performed on one single processor. Finally, the efficient control scheme is proposed for the tracking control of the motion platform.

• International Journal of Aeronautical and Space Sciences
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• v.16 no.3
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• pp.475-483
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• 2015

We propose a numerical scheme to simulate the time-domain echo signals at tracking radar for a realistic scenario where an EAD (expendable active decoy) and an airborne target are both in dynamic states. On various scenarios where the target takes different maneuvers, the trajectories of the EAD ejected from the target are accurately calculated by solving 6-DOF (Degree-of-Freedom) equations of the motion for the EAD. At each sampling time of the echo signal, the locations of the EAD and the target are assumed to be fixed. Thus, the echo power from the EAD can be simply calculated by using the Friis transmission formula. The returned power from the target can be computed based on the pre-calculated scattering matrix of the target. In this paper, an IPO (iterative physical optics) method is used to construct the scattering matrix database of the target. The sinc function-interpolation formulation (sampling theorem) is applied to compute the scattering at any incidence angle from the database. A simulator is developed based on the proposed scheme to estimate the echo signals, which can consider the movement of the airborne target and EAD, also the scattering of the target and the RF specifications of the EAD. For applications, we consider the detection probability of the target in the presence of the EAD based on Monte Carlo simulation.