• Journal of KSNVE
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• v.7 no.3
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• pp.387-392
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• 1997

This paper concerns a SCARA robot with the flexible forearm linked to the rigid upper arm. The equations of motion are derived by the Lagrangian mechanics. For controller design, the perturbation approach is taken to separate the original equations of motion into linear equations describing small perturbed motions and nonlinear equations describing purely rigid motion of the robot. To effect the desired payload motion, open loop control inputs are determined based on the inverse dynamics of the latter. In order to reduce the positional error during maneuver, an active vibration suppression is done. To this end, a feedback control is designed for robustness against disturbance on the basis of the linear equations and the LQR theory modified to have a prescribed degree of stability. The proposed control scheme shows satisfactory performances in experiments as well as in numerical simulations.

• Journal of Pharmaceutical Investigation
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• v.15 no.1
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• pp.40-44
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• 1985

The stability of ftorafur in artificial gastric juice and its major decomposition product were studied quantitatively by the combination of TLC technique and UV-recording spectrophotometry. The decomposition proceeded in first-order reaction. The decomposition rate was accelerated by the increase of temperature. The major decomposition products were identified as 5-fluorouracil. The apparent activation energy for the decomposition was found to he approximately 24.3kcal/mole from Arrhenius plot.

• Journal of the Korean Applied Science and Technology
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• v.27 no.1
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• pp.87-92
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• 2010

Silicone surfactants are widely used in many industrial area because of its thermal stability and lower foaming property. But it has limitation to expand the application because of migration and bubble generation issues when it is mixed with organic surfactant. In this study, epoxy functionalized fluoro-silicone surfactant, perfluoro glycidoxypropyl polyether siloxane(PFGES), was synthesized using hydrosilylation reaction among perfluoro methyl hydrogen siloxane, allyl glycidyl ether, and allyl ployether in order to get lower surface tension, better thermal stability than conventional silicone surfactant, and reactivity with anhydride function.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.205-207
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• 2006

Since a humanoid robot inherently suffers from instability and always risks tipping itself over, or topping to the ground, it is necessary to ensure high stability and reliability of walk. An unexpected ground condition is one of the principal factors of instability. This paper proposes a walk stabilization method consisting of a Fuzzy algorithm and geometry under uneven terrain. The ground reaction forces that are measured by the FSR sensors on the sole are used to check the ground condition and the robot posture. The effectiveness of proposed method is verified by computer simulations.

• Tribology and Lubricants
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• v.16 no.4
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• pp.266-273
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• 2000

The friction characteristics of phenolic resin and model friction materials were investigated with the content of hexamethylenetetamine (HEXA). At 10 wt.% of HEXA, the phenolic resin and model friction materials showed the most stable friction coeffcient in constant temperature test at various test conditions because of its good thermal stability and proper curing reaction. It was found from constant interval test in mild condition that the friction coeffcients of friction materials cured with 10 wt.% of HEXA was the highest and stable values in the whole range of braking operations. However, at the severe condition in constant interval test, the friction coefficient of friction materials cured with 10 wt.% to of HEXA was lowered and as the number of braking operation increased, the values became stable. In order to obtain the thormal stable friction materials, the content of HEXA from 5 to 10 wt.% could be recommended.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2271-2274
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• 2005

The desired ZMP is different from the actual ZMP of a humanoid robot during actual walking and stand upright. A humanoid robot must maintain its stable posture although external force is given to the robot. A humanoid robot can know its stability with ZMP. Actual ZMP may be moved out of the foot-print polygons by external disturbance or uneven ground surfaces. If the position of ZMP moves out of stable region, the stability can not be guaranteed. Therefore, The control of the ZMP is necessary. In this paper, ZMP control algorithm is proposed. Herein, the ZMP control uses difference between desired ZMP and actual ZMP. The proposed algorithm gives reaction moment with ankle joint when external force is supplied. 3D simulator shows motion of a humanoid robot and calculated data.

• YAKHAK HOEJI
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• v.23 no.3_4
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• pp.147-152
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• 1979

Experiments were carried out to investigate for the interaction between FAD solution and synthetic resin containers made of polyvinylchloride(PVC), polyethylene(PE), and polycarbonate(PC), and for the effect of glycyrrhizine or malic acid on stabilization of FAD in aqueous solution by accelerated stability analysis. Analysis of FAD was determined by means of spectrometer and by separating by paper chromatography and metal ions were detected by atomic absorption spectrophotometer, which were extracted from containers by means of Food and Additive Regulation Standard. The thermal decomposition of FAD in aqueous solution was pseudo first order reaction and it was inhibited by adding glycyrrhizine or malic into the solution. PVC, PE and PC containers accelerated the decomposition of FAD in solution. It is assumed that bivalent heavy metals in resin containers may catalize the hydrolysis of FAD. The metals detected from the containers were Ca, Zn, Cu, Fe, Pb and Cd. And the total amounts of detected metals from PVC were 6.2mcg/cm$^{2}$, PE, 5.5mcg/cm$^{2}$, and PC, 2.7mcg/cm$^{2}$ which were proportional to the rate constant of FAD decomposition in aqueous solution.

• Journal of the Korean Ceramic Society
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• v.36 no.9
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• pp.930-936
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• 1999

For LiMn2O4 based spinel structures the stoichiometric reaction conditions need be considered carefully because the electrical properties depend on the structural stability. In order to obtain the homogeneous compound the Pechini process was chosen which could obtain a stoichiometry phase even low temperature and dependency of the synthetic condition on structural stability and electrochemical performance was investigated. X-ray diffraction studies showed that the compounds doped with transition metal have smaller lattice constants than those un doped. The dc conductivity was evaluated by a four probe method in the low and high temperature region respectively. The variations of basal spacings for the cathode were detected to be dependent on the extent of current flows (under dc)

• Journal of Power System Engineering
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• v.12 no.6
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• pp.24-28
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• 2008

It expects demand of ships which equipped with JIB crane growth to continue. However, demand of JIB crane is increased, domestic shipment company imitated the design of Europe and Japan. And we need to develop the functional system of the JIB crane and modernize it. We need to find the optimum luffing angle for saving energy when JIB crane works. This study analyzed buckling load of JIB and reaction force of support point and stress of JIB according to the luffing angle through finite element analysis when JIB crane loads 40 ton weight. And this study considered the safety factor 1.8 of material. Every design condition was KS A1627 standard. This study used ANSYS 10.0.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.76-79
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• 2004

This research was carried out to evaluate role of supplementary reagents, such as phosphate and SDS, to remove hydrophobic organic contaminant from soils during the EK-Fenton process. The $H_2O$$_2$ stability improved due to the role as stabilizer of phosphate and SDS during the EK-Fenton process. Furthermore, although pH in region near cathode was 8.2 after test, $H_2O$$_2$ stability improved due to transportation of SDS in the region near cathode. Therefore, in tests using phosphate and SDS as supplementary reagent, the efficiency of phenanthrene treatment improved through the EK-Fenton process using longer reaction time.