• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 심포지엄 논문집 정보 및 제어부문
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• pp.232-233
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• 2008

There are various large shocks in optical disc drive system like human touch and speak sound. In this paper, a nonlinear controller and a detection method are proposed. First, a relay nonlinear controller with dead zone is introduced. The structure of this nonlinear controller is simple and has a small amount of calculation. However, this controller has chattering problem when it is working. We suggest a disturbance detection algorithm using Kalman filter in this paper and it shows effective reduction of chattering. The proposed nonlinear controller using this detection algorithm had good performance for the shock.

• KSBB Journal
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• 제19권5호
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• pp.381-384
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• 2004

The antimicrobial and antioxidative activities were investigated to confirm the utility of wood vinegar. Antimicrobial activity was performed by paper disc method and liquid culture. The growth inhibition was observed in all microbial species at a dose of as low as 25 $\mu$m of wood vinegar by paper disc method. Also, in liquid culture, S. cerevisiae and P. aeruginosa were more inhibited the growth than others in the concentration of $2\%$ (v/v). For measuring of antioxidative activity, wood vinegar was fractionated with acidic, phenolic, basic and neutral fraction; and their antioxidant activities were measured by the radical scavenging effect on DPPH radical. In four fractions, phenolic fraction showed high antioxidative activity.

• 전기의세계
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• 제29권10호
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• pp.653-659
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• 1980

The paper describes a new technique for the shape design of a bell-type porcelain locke insulator in contaminated environment. Early studies on the contamination performance of insulators indicated the need for an improvable shape to provide adequate insulation strength at normal operating voltages. In this paper, under lightly and heavily contaminated site severity, the variation of voltage distribution to leakage path at insulator surfaces analyzed by the complex admittance matrix using finite element method. By this results, the improvement of shape of insulators could be approached to the available condition in contaminated environments. In applicating to compare a standard disc type with a fog disc type insulator, this design technique is valid.

• Toxicological Research
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• 제27권4호
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• pp.241-246
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• 2011

To obtain soil microorganisms producing antimigratory activity which is important in controlling the metastasis of cancer cells, more than three hundreds of soil microbes were isolated from sixteen soil sources including Namsan mountain and designated as DGU1001-10338. At first, their antibiotic activities were examined by paper-disc method. More than 40 soil microbes produced compounds with antibiotic activity. Then, antimigratory activities of selected soil microorganisms were examined in a sphingosylphosphorylcholine-induced migration assay in PANC-1 cells. Six of 42 soil microorganisms having antibacterial activity also had more than 45% inhibitory activity on migration of PANC-1 cells. These results suggested that selected soil microorganisms were a useful starting point to find compounds for controlling metastasis of cancer cells.

• Natural Product Sciences
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• 제4권3호
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• pp.130-135
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• 1998

The water extracts of 83 oriental herbal medicines (Hanbang) which have been clinically used to treat bacterial infections in Korea were screened for in vitro antibacterial activity by the paper disc assay method. Two Gram positive bacteria, Staphylococcus aureus SG 511, Bacillus subtilis ATCC 6633, and two Gram negative bacteria, Escherichia coli 055, Pseudomonas aeruginosa 9027 were used as test organisms. Among the extracts tested, MeOH extract of Baenongtang showed remarkably potent antibacterial activity. Activity-guided chromatographic fractionations of the $CH_2Cl_2$ extract of Baenongtang afforded seven antibacterial compounds.

• 한국가축위생학회:학술대회논문집
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• 한국가축위생학회 1994년도 제17차 학술대회 및 정기총회
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• pp.140.2-140
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• 1994

• Tribology and Lubricants
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• 제5권1호
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• pp.21-27
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• 1989

A paper facirig, used for clutch disc or brake lining of the vehicles, is consisted of a combination of cellulose fiber of pulp with assorted filler and friction imparting particles, impregnated with a thermo-setting resin. In this study, as a substitution for the paper-production method, the molding-production method was attempted to produce the paper facings, and their frictional characteristics were investigated. According to the experimental results, it was estimated that the paper facings added with silica (SiO$_2$) have superior frictional characteristics, which is mused by the porosity and Mobs' hardness of the silica (SiO$_2$).

• 정보저장시스템학회논문집
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• 제11권1호
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• pp.6-10
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• 2015

Optical library system consists of disc magazines, cabinets, transfer robot and drive. Transfer robot delivers desired disc or magazine in cabinet to drive which reads data of disc. Conventional archive system stores discs in a line and transfer robot moves in one dimension. However, to store more discs, new optical archive system, optical library system, is developed which stores discs in two dimension like bookcase. Transfer robot should know the position and stored data of desired magazine to get correct data. In this paper, addressing algorithm using optical character recognition is proposed. Proposed algorithm is evaluated by experiments with implemented system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.115.4-115
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• 2002

The disc spinning machine is a specific production machine for discs of automobile. Using this machine, we could product superior wheels in hardness and strength to the press method and the machine made process time shorten by one-pass spinning. But, the spinning machine became huge because it needed maximum pressure during the process and this can badly affect the lifetime of components. In this paper, hydraulic control system was designed to make up for defects of spinning machine and to shorten overusing power. Experimental hydraulic control system was used to simulate the wheel disc spinning process and the control performance was evaluated for the required forces and positions.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.393-399
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• 2008

A modeling method for the modal analysis of a pre-twisted multi-packet blade system undergoing rotational motion is presented in this paper. Blades are idealized as pre-twisted cantilever beams that are fixed to a rotating disc. The stiffness coupling effects between blades due to the flexibilities of the disc and the shroud are modeled with discrete springs. The coupling effect between chordwise and flapwise bending deflection is also considered. Hybrid deformation variables are employed to derive the equations of motion. To obtain more general information, the equations of motion are transformed into dimensionless forms in which dimensionless parameters are identified. The effects of the dimensionless parameters and the number of packets as well as blades on the modal characteristics of the rotating multi-packet pre-twisted blade system are investigated with some numerical examples.