• Journal of the Korean Institute of Telematics and Electronics A
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• v.28A no.11
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• pp.910-914
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• 1991

This paper describes the improvement of frequency characteristic of crystal oscillator I.C using Ti-Salicide. The characteristics of transistor(drive current) using Ti-Salicide process are better than Poly-Si process, because the mobility. To know frequency characteristic of oscillator I.C, the simulation is performed using inverter buffer chain of Fan-out 10 TTL. Its result shows at once the generation of normal clock pulse in input signal and the improvement of rising and falling time.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.557-560
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• 2000

The Purpose of this study is analysis of kinematic for a modified manipulator and experimental test to certify auto-balancing operation. The test is carried out as follows. First, we solve the inverse kinematics and then do a closed loop control. Second we confirm translation displacement and rotation angle of a manipulator.

• Proceedings of the KAIS Fall Conference
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• 2006.05a
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• pp.232-235
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• 2006

본 논문은 금속 이온에 둘러싸인 다중벽 탄소 나노튜브를 이용한 기가급 진동자의 응용 가능성에 대한 해석을 수행하였다. 탄소 나노튜브 오실레이터 안쪽에 포함된 칼슘 이온들은 외부에서 공급된 전계에 의해 가속될 수 있고 $nK^+@CNT$ 오실레이터로 구성된 기가 헤르쯔 진동자는 본 연구의 분자동역학 시뮬레이션에서 공급된 전계에 의해 초기화될 수 있었다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.12
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• pp.1845-1855
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• 2004

This paper presents the forward kinematics of the Casing Oscillator that is a construction machine. The Structure of the Casing Oscillator is similar to those of 4 degree-of-freedom mechanisms with a redundancy. With analytical (geometrical) methods, the solutions of the forward position kinematics problem are significantly found by both solving an 8$^{th}$ -order polynomial equation in one unknown variable and using one over-constraint geometrical equation which can be derived under the condition of a redundancy. The proposed forward kinematics has closed-form solutions and allows Auto-Balancing control of the moving platform in real time. Numerical examples are presented and the results are verified by an inverse kinematics analysis.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.5
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• pp.688-696
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• 2003

The casing oscillator used for basic construction of buildings, factories and bridges is a construction machine, which rotates and rolls the casing to insert it into the ground. It is very important that the casing is positioned perpendicular to the sea level regardless of the slope of the ground. In this paper, we present a new casing oscillator that doesn't need additional work to level the ground for the casing insertion. The kinematic analysis fur work space of a casing oscillator is presented and carried out with auto-balancing of the casing oscillator using posture feedback control.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.782-785
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• 2002

The goal of this research is to deduce the robust design of mold oscillator of the continuous casting machine. In the case of the system operated in the high temperature condition, the structural problems caused by the heat are dominant. Therefore, the thermal stress is considered with the connection of the thermal and structural analyses. The cooling ability of the water jacket was estimated and the robustness of mold oscillator was judged with the displacement and stress distributions obtained by the finite element method. The analytic results were compared with the real values of the iron mill.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.442-445
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• 2002

The casing oscillator used for the foundation work in the construction place. Construction machinery which makes the casing rotate and roll can insert the casing in the ground. It is very important to make the casing perpendicular to sea level regardless of slope of ground. So in this paper, we present the new type casing oscillator that need not to level the ground for the work of casing insertion. The inverse kinematics analysis for the real-time control of casing oscillator is presented.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.12
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• pp.47-53
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• 2000

The casing oscillator is a construction equipment to clamp, oscillate and push a casing for foundation work. In case that the casing oscillator is operated on the slant ground, if another construction heavy equipment is not used, it is impossible to insert the casing in ground using only casing oscillator. So in this paper, we present the new casing oscillator that need not to level the ground for work of casing insertion. This mechanism can execute 4 DOF motion by actuating 5 single - rod hydraulic cylinders. The inverse kinematics analysis of the casing oscillator is performed and we verify the validity of kinematics analysis through the experiment.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.1
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• pp.100-108
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• 2004

In this paper, the new casing oscillator, which is a construction machine and which structure is similar to that of a parallel manipulator with redundancy, is proposed. The singularity analysis of this machine is performed by two different methods. First, the singularities are found by the numerical method at configurations where the rank of the Jacobian matrix becomes deficient. The singularities are outside the workspace. To investigate the physical information on these configurations, the singularities are examined by the geometric method at configurations where the casing oscillator cannot resist the external forces and moments applied to the upper platform due to losing static equilibrium. The results of the geometric method are the same as those of the numerical method. It proves that the new casing oscillator is free from the singularity, which causes serious problems to a parallel manipulator.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.7 no.4
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• pp.336-345
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• 1996

The S.O(synchronous osillator) oscillates at its natural frequency without the externa applied signal. But if the external signal is applied, the S.O starts to track the external frequency which can be sinusoidal, pulsed or some other waveform. Thus, the output is synchronized with the wide range of tracking bandwidth to the external frequency. Specifically, the S.O also posses frequency division and multiplication capability. All of these indicate that the S.O can overcome the difficulties of syschronization in coherent digital communication systems. This papers proposed application of DS/SS communication with study on the synchronous properties of S.O.