• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.85.3-85
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• 2002

In this study, we tried to investigate the impedance characteristic of human arm in a cooperative task. Human arm was moved in a desired trajectory. The motion was actuated by a 1 degree-of-freedom robot system. As the muscle is mechanically analogous to a spring-damper system, a second-order equation was considered as the model for arm dynamics. In the model, inertia, stiffness and damping factor were considered. The impedance parameter was estimated from the position and torque data obtained from the experiment and based on the "Estimation of Parametric Model". It was found that the inertia is almost constant over the operational time. The damping factor and stiffness were high...

• ETRI Journal
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• v.20 no.1
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• pp.96-112
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• 1998

The patentability of computer program has been discussed because of its deviation from the traditional definition of a patent. The relativities of computer programs to hardware are classified to measure the relative patentability of computer programs in this paper. It can be seen through the patentability analysis that the change in patentability basically follows an exponent part of the function is a damping factor that determines a patentability degree or trend. The basic patentability of computer programs is revealed when the damping factor value is 1, and a statistical patent specification, an appropriate expression of applicability and substantiality of computer programs is needed to acquire a patent right.

• Steel and Composite Structures
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• v.16 no.1
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• pp.1-21
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• 2014

Knee Braced Frame (KBF) is a special form of ductile eccentrically braced frame having a diagonal brace connected to a knee element, as a hysteretic damper, instead of beam-column joint. This paper first presents an experimental investigation on cyclic performance of two knee braced single span one-story frame specimens. The general test arrangement, specimen details, and most relevant results (failure modes and hysteretic curves) are explained. Some indexes to assess the seismic performance of KBFs, including ductility; response reduction factor and energy dissipation capabilities are also subsequently discussed. Experimental results indicate that the maximum equivalent damping ratios achieved by test frames are 21.8 and 23% for the specimens, prior to failure. Finally, a simplified analytical model is derived to predict the bilinear behavior of the KBFs. Acceptable conformity between analytical and experimental results proves the accuracy of the proposed model.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.09a
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• pp.189-196
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• 2002

The capacity of CFS piers has not been used to a practical design, because there is no guide of a seismic design for CFS piers. Therefore, the guide of a seismic design value is derived from tests of CFS piers in order to apply it to a practical seismic design. Steel piers and concrete-filled steel piers are tested with constant axial load using quasi-static cyclic lateral load to check ductile capacity and using the real Kobe ground motion of pseudo-dynamic test to verify seismic performance. The results prove that CFS piers have more satisfactory ductility and strength than steel piers and relatively large hysteretic damping in dynamic behaviors. The seismic performance of steel and CFS piers is quantified on the basis of the test results. These results are evaluated through comparison of both the response modification factor method by elastic response spectrum and the performance-based design method by capacity spectrum and demand spectrum using effective viscous damping. The response modification factor of CFS piers is presented to apply in seismic design on a basis of this evaluation for a seismic performance.

• The Korean Journal of Rheology
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• v.3 no.2
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• pp.156-165
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• 1991

폴리비닐리덴플루오라이드 바이모프 외팔보(poly(vinylidene fluoride) bimorph cantilever beam)의 진동을 기술하는 수학적 모형을 세우고 실험으로 그모형의 타당성을 고 찰하였다. 여러 전압의 교류전류에 대해 여러 길이의 외팔보의 주파수응답을 측정하였고 여 러 전압의 직류전류에 대해 여러 길이의 외팔보의 처짐을 측정하였다. 실험으로부터 이 외 팔보의 진동은 점성감쇠보다는 구조감쇠로 기술하는 것이 더 타덩하고 외팔보가 전기장에 대해 damping factor가 일정해야 하나 각각의 normal mode에 대해 다른 damping factor로 수정하여 계산한이론치가 실험과 더 일치하였다. 공명주파수의 공명진폭을 예측할수 있고 넓은 입력주파수 영역에 대한 외팔보의 응답을 기술 할수 있으며 진동하는 외팔보는 모든위 치에서의 진폭을 기술할수 있다는 점에서 여기서의 모형은 Toda와 Smits의 모형들보다 우 수하다고 볼수 있다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.7
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• pp.1689-1698
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• 1998

In this paper, we present a new method for estimating the parameters of transient-type signal in additive white Gaussian noise. This method makes use of the truncated singular value decomposition of an extended-order auto-correlation-like matrix based on the linear-prediction model. The method is tested on data consisting of two exponentially dampled sinusoidal signals with the same damping factor and different damping factor. Simulation results are illustrated to demonstrate the better performance of the method applied to the auto-correlation-like matrix than that applied to the data matrix.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.157-162
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• 2003

This Paper presents a robust design of an Electrorheological(ER) damper using Taguchi method. Taguchi method is a robust design method that determines control parameters in the presence of noise effect. Electrode length, electrode gap, base oil viscosity and the weight ratio of ER particles are chosen for the control parameters and the temperature is considered to be a noise factor. The sensitivity of each factor with signal-to-noise(S/N) ratio and analysis of variance are investigated. The analysis results show that the electrode length and base oil viscosity of the ER fluid mostly affect the damping force in the absence of electric field. On the other hand, when the voltage is applied to the ER damper, the electrode length and the weight ratio of ER fluid exhibit significant effect. Based on the Taguchi method, an optimal configuration was designed and the robustness of the designed ER damper was validated by comparing the analysis and experimental results.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.5
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• pp.707-714
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• 2000

In this paper, using third-order system of the PLL we'll analyze the aspect of flicker noise appearing troubles in the low frequency band. Since it is difficult to analyze mathematically flicker noise in the third-order system of the PLL, introducing the concept of pseudo-damping factor using the optimized second-filter has made an ease of the access of the flicker-noise variance. we'll show a numerical formula of flicker variance in the third-order system of the PLL which is compared with that of 1/f noise variance in the second-order system of the PLL.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.11a
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• pp.230-235
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• 1999

In this paper, Using third-order system of the PLL we analyze the aspect of flicker noise appearing troubles In the low frequency band. Since i. Is difficult to analyze mathematically flirter noise In the third-order system of the PLL, introducing the concept of pseudo-damping factor using the optimized second-filter makes an ease of the access of the flicker-noise variance. we'll show a numerical formula of flicker variance in the third-order system of the PLL which is compared with that of 1/f-noise variance in the second-order system of the PLL.

• Journal of the Institute of Convergence Signal Processing
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• v.3 no.1
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• pp.67-73
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• 2002

This paper presents a new design method of optimal continuous deadbeat controller by using second-order smoothing elements. The continuous deadbeat controller is made of a serial integral compensator and a local feedback compensator introduced into the state feedback loop. The decision method of the damping factor and the natural angular frequency of the smoothing element is described. A numerical example is given to show how well input-output characteristics are improved. Especially according to the variable input and disturbance, corresponding CDBC design method is suggested. By computer simulations, control inputs and system outputs are shown to have desirable property such as smoothness.