• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.551-556
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• 1991

This paper deal with the solution of kinematics and inverse kinematics of industrial FANUC robot by the bisection method with IBM PC 386. The inverse kinematics of FANUC robot cannot be solved by the algebraical method, because arm matrix T$_{6}$ is very complex and 6-joint angles are associated with the position and the approach of end-effector. Instead we found other 5-joint angle by an algebraical method after finding .theta.$_{4}$ value by a bisection method.d.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.124-126
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• 1989

Inverse kinematic problem is a crucial point for robot manipulator control. In this paper, to implement the Jacobian control technique we used the Hopfield(Tank)'s neural network. The states of neurons represent joint veocities, and the connection weights are determined from the current value of the Jacobian matrix. The network energy function is constructed so that its minimum corresponds to the minimum least square error. At each sampling time, connection weights and neuron states are updated according to current joint position. Inverse kinematic solution to the planar redundant manipulator is solved by computer simulation.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.655-658
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• 1999

In this paper we design a key-frame editor for 3D sign-language animation using the inverse kinematics. Using the editor, we can calculate the joint angles for two arms automatically. Up to now we have computed the values of the joint angles using the forward kinematics, where we have determined the values heuristically based on our experiences. To overcome the drawbacks, we employ the arm transformation matrix of the inverse kinematics. Experimental results show a possibility that the proposed method could be used for making up the sign-language communication dictionaries.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1989.10a
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• pp.15-18
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• 1989

The planar effects on the concrete pavements Is mainly due to the concrete shrinkage, subgrade friction, and thermal expansion or contraction. A complete understanding of analytical behavior of concrete pavement requires the development of computer model, stiffness matrix and equivalent nodal load matrices due to the effects mentioned above. A computer program, INPLANE II, has been written to evaluate the planar effects on concrete pavements. The planar effects determine to what degree the joint open and also help In determining factors which affect the joint stiffnesses and structural behavior of concrete Pavements.

• ETRI Journal
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• v.36 no.3
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• pp.460-468
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• 2014

This paper addresses the problem of joint time of arrival (TOA) and direction of arrival (DOA) estimation in impulse radio ultra-wideband systems with a two-antenna receiver and links the joint estimation of TOA and DOA to the sparse representation framework. Exploiting this link, an orthogonal matching pursuit algorithm is used for TOA estimation in the two antennas, and then the DOA parameters are estimated via the difference in the TOAs between the two antennas. The proposed algorithm can work well with a single measurement vector and can pair TOA and DOA parameters. Furthermore, it has better parameter-estimation performance than traditional propagator methods, such as, estimation of signal parameters via rotational invariance techniques algorithms matrix pencil algorithms, and other new joint-estimation schemes, with one single snapshot. The simulation results verify the usefulness of the proposed algorithm.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.894-897
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• 2004

In this paper, we address a position control scheme for a stage system, which is levitated and driven by electric magnetic actuators. This consists of a levitating object (called platen) with 4 permanent magnetic linear synchronous motors in parallel. Each motor generates vertical force for suspension against gravity and propulsion force horizontally as well. This stage can generate six degrees of freedom motion by the vertical and horizontal forces. Dynamic equations of the stage system are derived based on Newton-Euler method and its special Jacobian matrix describing a relation between the Joint velocity and platen velocity is done. There are proposed two control schemes for positioning, which are Cartesian space controller and Joint space controller. The control performance of the Cartesian space controller is better than the Joint space controller in task space trajectory while the Joint space controller is simpler than the Cartesian space controller in controller realization.

• Structural Engineering and Mechanics
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• v.45 no.4
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• pp.423-437
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• 2013

Complex structures are usually assembled from several substructures with joints connecting them together. These joints have significant effects on the dynamic behavior of the assembled structure and must be accurately modeled. In structural analysis, these joints are often simplified by assuming ideal boundary conditions. However, the dynamic behavior predicted on the basis of the simplified model may have significant errors. This has prompted the researchers to include the effect of joint stiffness in the structural model and to estimate the stiffness parameters using inverse dynamics. In the present work, structural joints have been modeled as a pair of translational and rotational springs and frequency equation of the overall system has been developed using sub-structure synthesis. It is shown that using first few natural frequencies of the system, one can obtain a set of over-determined system of equations involving the unknown stiffness parameters. Method of multi-linear regression is then applied to obtain the best estimate of the unknown stiffness parameters. The estimation procedure has been developed for a two parameter joint stiffness matrix.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.6
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• pp.638-648
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• 1990

An effective resolved motion control method of redundant manipulators is proposed to minimize the energy consumption and to increase the dexterity while satisfying the physical actuator constraints. The method employs the neural optimization networks, where the computation of Jacobian matrix is not required. Specifically, end effector movement resulting from each joint differential motion is first separated into orthogonal and tangential components with respect to a given desired trajectory. Then the resolved motion is obtained by neural optimization networks in such a way that 1) linear combination of the orthogonal components should be null 2) linear combination of the tangential components should be the differential length of the desired trajectory, 3) differential joint motion limit is not violated, and 4) weighted sum of the square of each differential joint motion is minimized. Here the weighting factors are controlled by a newly defined joint dexterity measure as the ratio of the tangential and orthogonal components.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.3
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• pp.566-576
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• 1997

This study was performed to evaluate the tensile strength of solder joint in titanium and the wettability of 14K gold solder on titanium. Two pieces of titanium rod 30 mm in length and 3mm in diameter were butt-soldered with a 14K gold solder using the electric resistance heating under flux-argon atmosphere, the infrared heating under argon atmosphere, and the infrared heating under vacuum-argon atmosphere. A tensile test was performed at a crosshead speed of 0.5 mm/min, and fracture surfaces were examined by SEM. To evaluate the wettability of 14K gold solder on titanium, titanum plates of a $17{\times}17{\times}1mm$ were polished with #80-#2000 emery papers, and the spreading areas of solder 10 mg were measured by heating at 840 * for 60 seconds. The solder-matrix interface regions were etched by the solution of 10% KCN-10% (NH4)2S2O8, and analyzed by EPMA. The results obtained were summarized as follows ; 1. The maximum tensile strength was obtained when the titanium surface was polished with #2000 emery paper and soldered using the electric resistance heating under flux-argon atmosphere. Soldering strengths showed the significant difference between the electric resistance heating and the infrared heating(p<0.05). 3. The fracture surfaces showed the aspect of brittle fracture, and the failure developed along the interfaces of solder-matrix reaction zone. 4. The EPMA data for the solder-matrix interface region revealed that the diffusion of Au and Cu occurred to the titanium matrix, and the reaction zone showed the higher contents of Au, Cu and Ti than others.

• Journal of Korean Medicine Rehabilitation
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• v.29 no.2
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• pp.101-113
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• 2019

Objectives Bogol-tang has clinically been used to protect joint cartilage and to treat osteoarthritis. Our objective was to study the protective effect of Bogol-tang extract (BGT) in functional impairment, behavioral disorders, cartilage loss and pathological changes in a monoiodoacetate (MIA)-induced murine osteoarthritis (OA) model and interleukin (IL)-$1{\beta}$ -treated primary rat chondrocytes. Methods Mouse knee joints were injected with MIA, a chemical that inhibits glycolysis and causes joint inflammation and matrix loss. MIA-OA induced mice orally administered BGT or acetaminophen (AAP) for 18 days by daily. Primary rat chondrocytes were pretreated with BGT or dexamethasone (DEX) and followed by co-incubation with IL-$1{\beta}$ (10 ng/mL). Results In MIA-OA mice model, BGT led to delayed response on hot plate analysis, and suppressed the cartilage loss and damages in joint tissues. BGT suppressed the elevated levels of inflammatory mediators, nitrite and $PGE_2$, the gene expression of matrix degrading enzymes, and extracellular-signal-regulated kinases 1/2 and c-JunN-terminal kinase phosphorylation in IL-$1{\beta}$-treated primary rat chondrocytes. Conclusions Our results suggest that BGT improve the knee joint function and delay the cartilage damages by anti-nociceptive, anti-inflammatory and ant-catabolic effects, which indicate BGT could be a potential candidate for osteoarthritis treatment.