• Food Science and Preservation
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• v.6 no.1
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• pp.110-114
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• 1999

In order to study the natural preservation of food, sixteen kinds of medicinal plants were extracted by 80% methanol and then antimicrobial activity of the extracts was investigated against various kinds of microorganisms. The extracts of medicinal plants showed good effects of antimicrobial activity against bacteria except Bacillus cereus, Escherichia coli O-157. Especially, the extracts of Artemisia annua, Aster scaber, Solidago virganrea shower good inhibitory effects on the growth of bacteria to the cooling preservation foods, and Artemisia annua was decreased of the TMA(Trimethylamine) test. the result thus indicate that Artemisia annua, Aster scaber, Solidago fischeri extract inhibitory effects on cooling preservation foods, so that it may be potential as a natural preservatives.

• Journal of Technologic Dentistry
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• v.13 no.1
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• pp.9-13
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• 1991

The purpose of this study was to determine the marginal fit of recasting by used nickel-chromium metal alloys, Hi-Crown, New-Crown and CB-80. Ninety crown prosthetics were divided into eighteen groups according to new to old metal ratios. Each crown was seated on its master die and then the marginal gaps were measured under optical microscope($\times$50). All groups were showed good marginal fit, except group 3 of Hi-Crown(156$\mu$m). The results suggest that the marginal fit of Ni-Cr metal alloy casting bodies were good as without concerned to mixed ratios and metals.

• Journal of the Korean Society of Industry Convergence
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• v.6 no.3
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• pp.177-183
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• 2003

Recently, Ryu et al. proposed a multiple target DOA tracking algorithm, which has good features that it has no data association problem and simple structure. But its performance is seriously degraded in the low signal-to-noise ratio. In this paper, a measurement fusion method is presented based on ML(Maximum Likelihood), and the new DOA tracking algorithm is proposed by incorporating the presented fusion method into Ryu's algorithm. The proposed algorithm has a better tracking performance than that of Ryu's algorithm, and it sustains the good features of Ryu's algorithm.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.7
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• pp.2182-2195
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• 1996

Densification characteristics and behavior of tool steel powder compact during high temperature forming processes were investigated under pressure less sintering, sinter forging and hot isostastic pressing. In pressureless sintering, full density was obtained at a closely controlled temperature near the solidus of the material. Finite element calculations from constitutive model for densification by power law creep and diffusional flow were compared with experimental data. Agreements between theoretical calculations and experimental data were good in hot isostatic pressing but not as good in sinter forging.

• Earthquakes and Structures
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• v.10 no.5
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• pp.1111-1123
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• 2016

To study seismic performance of steel frame-bent structure, one specimen with one-tenth scale, three-bay, and five-story was tested under reversed cyclic lateral load. The entire loading process and failure mode were observed, and the seismic performance indexes including hysteretic loops, skeleton curve, ductility, load bearing capacity, drift ratio, energy dissipation capacity and stiffness degradation were analyzed. The results show that the steel frame-bent structure has good seismic performance. And the ductility and the energy dissipation capacity were good, the hysteresis loops were in spindle shape, which shape were full and had larger area. The ultimate elastic-plastic drift ratio is larger than the limit value specified by seismic code, showing the high capacity of collapse resistance. It can be helpful to design this kind of structure in high-risk seismic zone.

• Korean Journal of Artificial Intelligence
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• v.4 no.1
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• pp.1-3
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• 2016

These days, citizens are interested in the energy. IT technology needs to develop and to make use of energy effectively and to save energy. In this study, motion recognition LED lamp was used to have good energy efficiency and to be made of environment friendly material. The purpose of development of the lamp was to add motion recognition to LED lamp. In this study, infrared ray sensor's distance measurement was used to develop LED lamp. Most of the lamps were used under dark environment, so that infrared ray sensor was used to perceive movement under dark environment. And, LED lamp with good efficiency and less power consumption was used to increase efficiency. Citizens were interested in perception of the movement to distinguish from conventional type of the lamps.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.05a
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• pp.254-258
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• 2004

Actual trends in automotive industry lead to an increase use of lightweight structures imposing the need fur high strength aluminum alloys with complex shape. In the electromagnetic stirring process, it has many merits which are the exact control ability about material processing and a good point of the protection of environment comparison with the mechanical stirring. The interface of cells consisting of primary particle formed by the electromagnetic stirring due to particle regrowth during cooling the alloy. By electromagnetic stirring process, the microstructure of material has a good point, also it can control the material processing exactly.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.04a
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• pp.104.2-105
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• 2003

Plant steryl esters have good effects on plasma cholesterol level and are used as functional food ingredient. Conjugated linoleic acid (CLA) presents mainly in animal foods and has a good benefit and medium chain fatty acids (MCFAs) are a rapid energy source for human. In this study, we produced the ${\beta}$-sitosterol esters from CLA and MCFAs using various lipases as catalysts. Among lipases, AYS (from Candida rugosa) was the most effective for synthesis of ${\beta}$-sitosterol esters in the presence of water (24.35% conversion) or hexane (25.33% conversion). The second esterification extent was obtained by lipase AK (from Pseudomonas sp), showing 10.26% conversion in water and 15.94% conversion in hexane, respectively. The reaction condition was 1:3 molar ratio (${\beta}$-sitosterol:fatty acid, 1:3) and stirred (175 rpm) at 55$^{\circ}C$ in water bath shaker for 48h.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1871-1876
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• 2005

In this paper, We present a new nonlinear adaptive control law using a disturbance accommodating control (DAC) observer for a Japanese automatic landing flight experiment vehicle called ALFLEX. A future spaceplane must have ability to deal with greater fluctuations in the stability and control derivatives of flight dynamics, because its flight region is much wider than that of conventional aircraft. In our previous studies, digital adaptive flight control systems have been developed based on a linear-parameter-varying (LPV) model depending on dynamic pressure, and obtained good simulation results. However, under previous control laws, it is difficult to accommodate uncertainties represented by disturbance and nonlinearity, and to design a stable flight control system. Therefore, in this study, we attempted to design a nonlinear adaptive control law using the DAC Observer and inverse dynamic methods. A good tracking property of the obtained system was confirmed in numerical simulation.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.10
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• pp.112-122
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• 1994

Number plates of vehicles operating in real world are sometimes difficult to recognize due to the number plate degradation (bent or dirty plates). To recognize the vehicle number from a number plate with severe degradation, good segmentation is necessary, which in turn requires good thresholding. This paper proposes a binarization method that combines the fast processing speed of global thresholding methods with the local thresholding methods' ability to adapt to lacal gray level characteristics. The proposed method overcomes the degradation of number plates quickly and maintains the widths of digit strokes uniform. The paper presents results of comparison with existing global and local thresholding methods.