• The Bulletin of The Korean Astronomical Society
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• v.32 no.2
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• pp.74.1-74.1
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• 2007

• Bulletin of the Korean Space Science Society
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• 1994.04a
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• pp.18-18
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• 1994

No Abstract. See Full-text

• The Bulletin of The Korean Astronomical Society
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• v.34 no.1
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• pp.129.1-129.1
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• 2009

• Journal of Oral Medicine and Pain
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• v.17 no.2
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• pp.27-35
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• 1992

The purpose of this study was to evaluate the size of the temporomandibular joint space by the increase of the occlusal force on the working side and the non-working side during unilateral biting. For the study, 22 normal adults, age from 23 to 25, who had normal or class I molar relationship and had no symptoms on TMJ area and masticatory muscles were selected. Transcranial TMJ radiograph was taken during unilateral biting with the sensor of occlusal load measuring device (MPM-3000 ; Nihon Kohden Kogyo Co. Ltd., Japan) on 1st molar teeth of right and left side given to force of 0kg, 10kg, 20kg and 30kg respectively with Accurad-200(Denar Corperation's product). The radiographs were traced on the screen, with enlaged as 5 times. The size of temporomandibular joint space at anterior, superior and posterior compartment were measured with Dumas's method (reference line between squamotympanic fissure and the lowest point of articular eminence). The following results were obtained by this study. 1. The size of anterior TMJ space showed a tendency to decrease on the working side and increase on the non-working side by the increase of the occlusal force, but had no statistical significancy (P>0.05). 2. The size of superior TMJ space showed a tendency to increase on the working side and decrease on the non-working side by the increase of the occlusal force (P<0.05). 3. The size of posterior TMJ space showed a tendency to decrease on both working and nonworking side, but had no statistical significancy (P>0.05)

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.265-268
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• 2004

In this paper. we propose an adaptive step-size algorithm for the adaptive interference canceller (AIC) in the space-time trellis coded DS-CDMA system. In the AIC, the performance of the blind LMS algorithms that updates the tap-weight vector of the AIC is heavily dependent on the choice of step-size. To improve the performance of the fixed step-size AIC (FS-AIC), the regular adaptive step-size algorithm is extended in complex domain and applied to the joint AIC and ML decoder scheme. Simulation results show that the joint adaptive step-size AIC (AS-AIC) and ML decoder scheme using the proposed algorithm has boner performance than not only the conventional ML decoder but also the joint FS-AIC and ML decoder scheme without much increase of the decoding delay and complexity.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.1
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• pp.142-149
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• 1995

This paper presents a new kinematic control strategy for serial redundant manipulators which gives repeatability in the joint space when the end-effector undergoes some general cyclic motions. Theoretical development has been accomplished by deriving a new inverse kinematic equation that is based on springs being conceptually located in the joints of the manipulator. Although some inverse kinematic equations for serial redundant manipulators have been derived by many researchers, the new strategy is the first to include the free angles of torsional springs and the free lengths of the translational springs. This is important because it ensures repeatability in the joint space of a serial redundant manipulator whose end-effector undergoes a cyclic type motion. Numerical verification for repeatability is done in terms of Lie Bracket Condition. Choices for the free angle and torsional stiffness of a joint (or the free length and translational stiffness) are made based upon the mechanical limits of the joints.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.10
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• pp.17-26
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• 2004

This paper proposes JBSTBC (Joint Beamforming Space-Time Block Coding) scheme for MIMO (Multi-Input Multi-Output) communication systems. To enhance the order of spatial diversity in presence of deteriorative fading correlations as well as inter-substream interferences, the proposed JBSTBC method employs joint eigen-beamforming technique together with the BOLD (block-ordered layered detector) for MIMO-STBC. In order to confirm superiority of the proposed JBSTBC method, the computer simulations are conducted in highly correlated fading situations with providing detailed mathematical derivations for clarifying functionality of the proposed scheme.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.1-6
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• 1992

A principle of "orthogonalization" is proposed as an extended notion of hybrid (force and position) control for robot manipulators under geometric endpoint constraints. The principle realizes the hybrid control in a strict sense by letting position and velocity feedback signals be orthogonal in joint space to the contact force vector whose components are exerted at corresponding joints. This orthogonalization is executed via a projection matrix computed in real-time from a gradient of the equation of the surface in joint coordinates and hence both projected position and velocity feedback signals become perpendicular to the force vector that is normal to the surface at the contact point in joint space. To show the important role of the principle in control of robot manipulators, three basic problems are analyzed, the first is a hybrid trajectory tracking problem by means of a "modified hybrid computed torque method", the second is a model-based adaptive control problem for robot manipulators under geometric endpoint constraints, and the third is an iterative learning control problem. It is shown that the passivity of residual error dynamics of robots follows from the orthogonalization principle and it plays a crucial role in convergence properties of both positional and force error signals.force error signals.

• Journal of the Korean Wood Science and Technology
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• v.23 no.4
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• pp.91-97
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• 1995

Cyclic tests were performed with dowel joints which are being widely used for furniture manufacturing in Korea. In this study, effects of various factors-such as species of joint members, diameter and length of dowels, and space between dowels-on stiffness, strength and damping ratio of joints were evaluated and concluded as follows: 1. Under cyclic loads, failure of dowel joints were caused by bending failure of dowels. 2. Dowel joints were evaluated to be stiff but general load carrying capacities were relatively low. 3. Joint moduli and damping ratios of dowel joints decreased as diameter and length of dowels, and space between dowels increased. 4. In dowel joints, properties of dowel itself have greater effects on stiffness and strength of joints than properties of joint members.

• The Korean Journal of Pain
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• v.9 no.1
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• pp.105-108
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• 1996

Localized or radiating pain in the arm and shoulder joint may result after faulty alignment causing compression or tension on nerves, blood vessels, or supporting soft tissues. The critical site of faulty alignment is the quadrangular space in the axilla bounded by the teres major, teres minor, long head of triceps, and humerus. The axillary nerve emerges through this space to supply the deltoid and teres minor. The activity of the trigger point on teres minor compressing the axillary nerve causes pain to develop through the area of sensory distribution of cutaneous branch of the axillary nerve. Relieving compression on the axillary nerve and suprascapular nerve is the key point to relieving the pain. Spasm of the supraspinatus and infraspinatus compressing the suprascapular nerve caused pain to develop in the shoulder joint and scapular area. We treated those patients experiencing such pain with local anesthetic infiltration or I-R laser stimulation on the identified trigger points.