• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.111.5-111
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• 2002

●NGMS ●Digital Factory ●S-Diagnostics ●Fuzzy Logic ●Neural Network ●DPNN ●Data Mining & Knowledge Discovery

• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.47-48
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• 2017

• Journal of the Computational Structural Engineering Institute of Korea
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• v.16 no.3
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• pp.301-309
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• 2003

The non linear control algorithm with actuator saturation for a randomly excited oscillator has been widely explored and has shown promising results, but the probabilistic analysis of the algorithm has been rarely made due to its non-linear nature and the fact that the analytical solution of probability density function (PDF) for controlled responses does not exist. In this paper, a method for the probabilistic analysis on the non linear control algorithm with actuator saturation is proposed based on the equivalent non linear system method. Numerical examples are given to verify the approximation solution of PDF comparing to a statistically obtained PDF using a Gaussian white noise and a Kanai - Tagimi filtered Gaussian white noise.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.11
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• pp.2119-2125
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• 1992

An air-fuel ratio control method is studied to keep the air-fuel ratio of the exhaust gas in the neighborhood of the stoichiometric air-fuel ratio to maximize the conversion efficiency of the three-way catalytic converter. Estimators, which estimate the air-fuel ratio of the exhaust gas, are proposed using neural networks to overcome the limit of the presently used bang-bang type exhaust gas oxygen sensor. Using these estimators, PI controller for air-fuel ratio control is designed and is experimented for an automobile engine. The proposed controller reduces the variation of air-fuel ratio of the exhaust gas from the stoichiometric air-fuel ratio by 50%-75% when compared to the existing controller.

• The Journal of Korean Medicine
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• v.29 no.4
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• pp.68-82
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• 2008

Objective: The purpose of our study was to show the effects of Hwalhyulmaksung-bang (Huoxiemoxing-fang, HHMSB) treatment on cBSA-induced in MN Mouse Model. Methods: We divided the 20 mice into 4 groups. One group, named NR, was not treated. The second group, named CT, was treated with cBSA (7mg/kg i.p) only. The third group, named HH-250, was treated with cBSA (7mg/kg i.p) and HHMSB extract (250mg/kg, p.o). The fourth group, named HH-500, was treated with cBSA (7mg/kg i.p) and HHMSB extract (500mg/kg, p.o). 4 weeks after cBSA, proteinuria, serum albumin, total cholesterol, serum creatinine, BUN, total cell number of spleen and kidney of all groups were measured. CD3e+/CD19+ and CD4+/CD8 cells ratio of peripheral blood, kidney and spleen of all groups were analyzed. $IL-1{\beta}$ and TNF-$\alpha$, IL-6, IgG, IgM, and IFN-$\gamma$ levels of all groups were gauged. Histological analysis of kidney tissue and immunohistochemical staining (CD4, CD8) of kidney were observed. Results: The level of proteinuria significantly decreased and serum albumin increased in the group treated with cBSA and HHMSB extract compared with the control. Total cholesterol decreased but not significantly. CD3e+/CD19cells ratio of peripheral blood is decreased, but CD4+/CD8cells ratio has no significancy. CD3e+/CD19+ and CD4+/CD8 cells percentage of kidney and spleen has no significancy. Level of $IL-1{\beta}$, IL-6 is significantly decreased, and IFN-$\gamma$ is significantly increased on HHMSB compared with control. Total IgG level significantly decreased on HHMSB compared with the control. Thickness of GBM decreased on histological analysis of kidney. Deposition of CD4 and CD8 decreased on immunohistochemical staining of kidney. Conclusions: We conclude that Hwalhyulmaksung-bang treatment may could be a useful remedy agents for treating Membranous Neuropathy(MN) induced by cationized bovine serum albumin.

• The Journal of Internal Korean Medicine
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• v.35 no.4
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• pp.505-518
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• 2014

Objectives: This study was undertaken to investigate the effects of Gugijagami-bang (GGB) in a hyperlipidemic animal model induced by a high-fat diet using diverse biological methods. Methods: This study was to determine whether fractionated GGB extracts inhibit reactive oxygen species (ROS) and nitric oxide (NO) in RAW 264.7 cells. Hyperlipidemia was induced by a high-fat diet fed for 6 weeks. Total cholesterol, LDL cholesterol, HDL cholesterol, triglyceride, liver function and histologic change of liver were measured after oral administration of GGB. Results: 1. DPPH scavenging bow performance was increased in a concentration-dependent manner by GGB. 2. Compared to the control group, NO production (%) and ROS production (%) were decreased significantly by GGB. 3. Total-cholesterol, LDL-cholesterol, triglyceride were decreased significantly by GGB. 4. HDL cholesterol increased more than the control group, but not significantly. 5. In histopathologic examination, fatty liver (hepatic steatosis) was inhibited, almost no rounds of fat were observed in the liver. Conclusions: GGB would appear effective in the prevention and treatment of atherosclerosis, ischemic heart disease, other cardiovascular diseases caused by hyperlipidemia.

• International Journal of Aeronautical and Space Sciences
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• v.8 no.2
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• pp.17-27
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• 2007

Minimum-time attitude maneuvers of three-axis stabilized spacecraft are presented to study the feasibility of using three magnetic torquers perform large angle maneuvers. Previous applications of magnetic torquers have been limited to spin-stabilized satellites or supplemental actuators of three axis stabilized satellites because of the capability of magnetic torquers to produce torques about a specific axes. The minimum-time attitude maneuver problem is solved by applying a parameter optimization method for orbital cases to verify that the magnetic torque system can perform as required. Direct collocation and a nonlinear programming method with a constraining method by Simpson's rule are used to convert the minimum-time maneuver problems into parameter optimization problems. An appropriate number of nodes is presented to find a bang-bang type solution to the minimum-time problem. Some modifications in the boundary conditions of final attitude are made to solve the problem more robustly and efficiently. The numerical studies illustrate that the presented method can provide a capable and robust attitude reorientation by using only magnetic torquers. However, the required maneuver times are relatively longer than when thrusters or wheels are used. Performance of the system in the presence of errors in the magnetometer as well as the geomagnetic field model still good.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.473-478
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• 1992

This paper aims to investigate the navigation control of a mobile robot in a confined environment. Steering angle becomes control variable which is computed from the fuzzy control rules. The identification method proposed in this paper presents the fuzzy control rules obtained through modelling of. the driving actions of human operator. The feasibility of the proposed method is evaluated through the application of the identified fuzzy controls rules to the navigation control of a mobile robot which follows the center of a corridor.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.03a
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• pp.417-423
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• 2002

Magnetorheological(MR) 댐퍼는 적은 용량의 전력을 사용하고 반응속도가 빠른 장점 때문에 구조물의 내진제어에 적당하여, 근래에 주목받고 있는 새로운 장치이다. MR 댐퍼는 반능동 제어 장치로써, 능동 질량감쇠기와는 다른 특성을 갖는다. 즉 필요한 제어력을 제어신호로 직접 생성해 낼 수 없는 대신에 MR 댐퍼의 입력전원을 제어하여 간접적으로 제어한다. 따라서 MR 댐퍼의 반능동 제어장치로써의 특성을 고려하는 효과적인 제어기법이 요구된다. 그러므로 본 연구에서는 지진에 대한 구조물의 응답을 줄이기 위해서, MR댐퍼를 제어할 수 있는 반능동 제어기법을 Lyapunov 안정성 이론을 바탕으로 제안하고자 한다. 제안방법을 검증하기 위해, 전단형 MR 댐퍼를 1층과 2층에 설치한 수치예제를 수행하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.9-13
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• 1997

This parer is a study on the inverse dynamics of a one-link flexible robot arm which is controlled by translational base motion. The system is composed of a flexible arm, a base for driving arm, a DC servomotor, and a computer. The arm base is moved so that the arm tip follows a desired function. The governing equations are based on the Bernoullie-Euler beam theory and solved by applying the Laplace transform method and then the numerical inversion method. Moter voltage is obtained by simulation for tip trajectory functions i. e. Bang-Bang, Cosine and Gauss Function. And, the tip motion is measured while simulation results are applying. Then the results are investigated to select most proper input and to compare their chateristics. Experimental results show the Cosine function is most proper with respect to low maximum voltage and steady state error.