• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.302-307
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• 2005

Recently, lots of parallel mechanisms for spatial 3-DOF and 6-DOF were investigated. However, research on 4-DOF and 5-DOF parallel mechanisms has been very few. In this paper, we propose a 4-DOF parallel mechanism that consists of 3-rotational and 1-translational motions. The kinematic characteristics of this mechanism are analyzed in terms of an isotropic index and maximum force transmission ratio, and its kinematic optimization is being conducted to ensure enhanced kinematic performances

• Journal of Korean Society of Water and Wastewater
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• v.18 no.2
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• pp.215-221
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• 2004

Effluent of wastewater treatment plant is to be disinfected to protect drinking water sources. DOF (Dissolved Ozone Flotation) was developed to meet this purpose. DOF was developed by combining DAF system with ozone. DAF system has good floating power with numerous microbubbles, and ozone has strong oxidation capability. And DOF system has good floating power and strong oxidation capability simultaneously. When DOF was applied to secondary wastewater effluent, color of 11CU in raw water which was secondary effluent was reduced to 1CU by the DOF system. Removal rate of other water quality parameters treated by DOF were also higher than that by DAF, which were proved the strength of oxidation capability of ozone. When ozone concentration of 3.3mg/l were applied in DOF system, general aerobic bacteria were reduced to 5CFU/ml from TNTC (Too many Numbers To Count). With the same ozone concentration, total coliform were not detected at all. These figures are under the numbers of drinking water regulation. These microbes were the target parameters of DOF. It was proved that DOF was very effective in disinfection of wastewater treatment plant effluent as well as in removal of color, turbidity, and T-P.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.672-676
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• 2004

In this paper, measuring system of 5 DOF motion errors are proposed using two capacitive type sensor, a straight edge and a laser interfoerometer. Yawing error and pitching error are measured using the laser interferometer, and rolling error is measured by the reversal method using a capacitive type sensor. Linear motion errors of horizontal and vertical direction are measured using the sequential two point method. In this case, influence of angular motion errors is compensated using the previously measured angular motion errors. In the horizontal direction, measuring accuracy is within 0.05 $\mu$m and 0.27 arcsec, and in the vertical direction, it is within 0.15 $\mu$m and 0.5 arcsec. From these results, it is confirmed that the proposed measureing system is very effective to the measurement of 5 DOF motion errors in the ultra precision feed tables.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.5
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• pp.875-880
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• 2020

In this paper, a novel 3-DOF hybrid robot with enlarged workspace is presented for high speed applications. The 3-DOF hybrid robot is made up of one linear actuator and 2-DOF planar parallel robot in series. The actuation consists of one ball-screw to make one linear motion and two rotary ball-screws to transmit rotational motion to 2-DOF parallel robot. The workspace can be enlarged according to ball-screw stroke and the moving inertia can be reduced due to locating all the heavy actuators at the fixed base. The inverse kinematics and workspace analyses are presented. The robot prototype and PC-based control system are developed.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.447-449
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• 2004

We proposed the method of the production of the humanoid biped robot and apply the A* path finding algorithm, for that robot mainly used in game and mobile robot, to avoid obstacles at real time. Actually we made the robot which has 20 DOF, 12 DOF in the two legs, 6 DOF in the two arms and each 1 DOF in the neck and waist, to realize human motions with minimal DOF, And we use the CATIA V5 for 3D modeling design and simulate.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.313-318
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• 2001

A haptic hand controller operated by the user's hand can receive information on position and orientation of the hand and display force and moment generated in the virtual environment to the hand. This paper presents a design method for KU-HHC, 6 DOF Korea University-haptic hand controller, which allows separation of workspace from linkage mechanism in consideration of the efficient user operation. First, the 3 DOF mechanism in which all the actuators are mounted on the fixed base is developed by combining a 5-bar linkage and gimbal mechanism. Then, the 6 DOF HHC is designed by connecting the two 3 DOF devices through a handle. This paper presents the forward and inverse kinematics for this device and Jacobian analysis. Improvement of the kinematic characteristics using performance index is also discussed. The hand controller KU-HHC based on this design concept and kinematic analysis was manufactured and shows excellent performance.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.2
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• pp.146-153
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• 2009

This study was conducted to examine the effects of fruits and stems of Opuntia ficus-indica var. saboten Makino on water intake, feed intake, body weight, blood glucose level and glucose tolerance in streptozotocin (STZ)-induced diabetic rats. Forty Sprague-Dawley male rats were divided into non-diabetic control (NC), diabetic control (DC), 8% Opuntia fruit (DOF), 5% Opuntia stem (DO-5) and 10% Opuntia stem (DO-10) groups. Fruits and stems of Opuntia ficus-indica were freeze-dried and ground before use in the experiment. Animals were fed experimental diet for 3 weeks. DOF, DO-5 and DO-10 groups showed lower water and feed intake as well as less body weight loss than DC group. The fasting blood glucose levels were 100 mg/dL for NC and 379 mg/dL for DC. Fasting glucose level of DOF was a significantly low level of 28% (p<0.05), whereas DO-5 and DO-10 had a decrease of 5% and 9% compared to DC. As for the glucose tolerance test, the highest blood glucose levels for NC and DC-10 group were observed at 30 minutes after glucose injection while those of DOF and DO-5 groups were after 60 minutes. DOF and DO-5 plasma insulin level improved. Plasma total cholesterol, triglyceride, non-esterified fatty acid (NEFA) and LDL-cholesterol concentrations were also lower in DOF, DO-5 and DO-10 groups, although HDL-cholesterol level was only slightly affected by experimental diets compared to DC. These results suggest that the feeding of Opuntia ficus-indica fruits and stems improved blood glucose and lipid metabolism in STZ-induced diabetic rats.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.886-889
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• 2003

In this paper a design of educational robot based on a PC and/or a microprocessor is discussed. The educational robot has 5 DOF and Is made with Swiss Mini Servomotor and Motor Controller IC LM629N. Also, a GUI(Graphical User Interface) is programmed by Visual Basic. This system is completed to consider control properties of the educational robot with 5-DOF that can be changed the parameter of controller by software.

• The Journal of the Acoustical Society of Korea
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• v.20 no.2
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• pp.58-65
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• 2001

Recently, a 5-degrees-of-freedom (DOF) reverberation model was proposed as a method of representing subjective perception of reverberation as objective measures[1]. This model approximates sound energy decay curve by five objective measures, widely used in which have been concert hall acoustics. However, it is note worthy that there can be infinite number of impulse responses which correspond to a selected 5-DOF reverberation model. There may exist some filters making very unnatural and unrealistic sound. In this paper, the limitation of the 5-DOF reverberation model when it is used as a filter design criteria is investigated. When a 5-DOF reverberation model is given, additional constraints to get natural reverberation are suggested. This is based on the listening tests for several quite different source sounds.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.129-130
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• 2011