• 한국산업정보학회논문지
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• 제7권1호
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• pp.50-57
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• 2002

본 논문은 다양한 문자 인식에 이용 가능한 WPTA4 알고리즘의 개선에 대한 연구이다. WPTA4 알고리즘은 각 화소의 연결성을 나타내는 연결 값을 이용함으로서 원래의 패턴에 매우 유사한 골격을 추출할 수 있는 알고리즘이다. 제안된 논문에서는 WPTA4 알고리즘에 나타나는 골격소멸현상을 보이고 이러한 현상을 제거할 수 있는 수정된 알고리즘을 제안하였다. 제안된 알고리즘은 골격소멸현상이 제거되었고 추출된 골격선의 품질이 우수함을 보였다.

• 소성∙가공
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• 제23권3호
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• pp.159-163
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• 2014

In the current study, the effect of small surface defects in the starting material including roughness, indentations, or scratches, which are perpendicular to the direction of drawing, on the product quality is investigated using the finite element method. An axisymmetric defect is assumed. Such defects are defined by a cylindrical defect area and two tapered regions connecting the defect area to the non-defective area of the material. Various conditions for these initial surface defects are considered, including defect depth, defect slope and defect length. To describe the plastic deformation of the defect in detail during the simulation, local remeshing is applied. Based on the finite element results, defect disappearance maps were generated. It was found that defect disappearance is significantly dependent on the defect depth and the defect length coupled with the defect slope.

• Advances in materials Research
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• 제2권2호
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• pp.111-118
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• 2013

The changes of plastic plateau in the stress-strain curves of annealed polypropylene (PP) films during stretching under room temperature were followed and the corresponding melting properties and microstructure were characterized by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). It was found that during stretching the plastic plateau disappeared progressively with the increase of drawing ratio. At the same time, the endotherm plateau in DSC curves also disappeared progressively. The presence of the plastic plateau was attributed to the stretching of unstable crystalline part which was formed by tie chains around initial row-nucleated lamellae structure during annealing. During stretching, the unstable part was stretched and converted to bridges connecting separated lamellae. There was direct relationship between the disappearance of plastic plateau and pore formation.

• Asian-Australasian Journal of Animal Sciences
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• 제2권3호
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• pp.311-314
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• 1989

• Asian-Australasian Journal of Animal Sciences
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• 제2권3호
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• pp.309-310
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• 1989

• Asian-Australasian Journal of Animal Sciences
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• 제2권3호
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• pp.307-308
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• 1989

• 한국재료학회지
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• 제11권12호
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• pp.1035-1041
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• 2001

The refining process and solubility of Ti in Al matrix during mechanical alloying (MA) were investigated by using X-ray diffraction (XRD), transmission electron microscopy (TEM) as functions of alloy composition, milling time and ball to powder ratio (BPR). Mechanical alloyed samples were annealed for investigating their stability and the formation behavior of$Al_3Ti$in the temperature range from$200{\circ}C$to$600{\circ}C$. It is observed from present experimental that disappearance of Ti peaks in mechanically alloyed Al-10wt%Ti is not simply attributable to the dissolution of Ti into Al, but associated mainly with extreme refining and/or heavy straining of Ti particles The annealing of the mechanically alloyed Al-Ti powders show differences in aluminide formation behavior when Ti content in Al is equal to or less than l0wt% and higher than l5wt%Ti. When Ti-content in Al is equal to or less than l0wt%, the MA powders transform directly to a global equilibrium state forming $DO_{22}- type\;Al_3$Ti above$400{\circ}C$. In the Al-Ti samples with equal to or higher than l5wt%Ti, transitional phases of cubic$Al_3Ti$and tetragonal $Al_{24}Ti_8$ are formed above$400{\circ}C$. They are stable only below$500{\circ}C$, and, $DO_{22}-type\;Al_3Ti$ becomes dominant aluminide at temperature higher than$ 600{\circ}C$.

• Bulletin of the Korean Chemical Society
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• 제31권5호
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• pp.1295-1300
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• 2010

The $CO_2-CH_4$ reaction catalyzed by Ni/silicon wafers was kinetically studied by using a photoacoustic technique. The catalytic reaction was performed at various partial pressures of $CO_2$ and $CH_4$ (50 Torr total pressure of $CO_2/CH_4/N_2$) in the temperature range of 500 - $650^{\circ}C$ in a static reactor system. The photoacoustic signal that varied with the $CO_2$ concentration during the catalytic reaction was recorded as a function of time. Under the reaction conditions, the $CO_2$ photoacoustic measurements showed the as-prepared Ni thin film sample to be inactive for the reaction, while the $CO_2/CH_4$ reactions carried out in the presence of the sample pre-treated in $H_2$ at $600^{\circ}C$ were associated with significant time-dependent changes in the $CO_2$ photoacoustic signal. The rate of $CO_2$ disappearance was measured from the $CO_2$ photoacoustic signal data in the early reaction period of 50 - 150 sec to obtain precise kinetic data. The apparent activation energy for $CO_2$ consumption was determined to be 6.9 kcal/mol from the $CO_2$ disappearance rates. The partial reaction orders, determined from the $CO_2$ disappearance rates measured at various $PCO{_2}'S$ and $PCH{_4}'S$ at $600^{\circ}C$, were determined to be 0.33 for $CH_4$ and 0.63 for $CO_2$, respectively. Kinetic data obtained in these measurements were compared with previous works and were discussed to construct a catalytic reaction mechanism for the $CO_2-CH_4$ reaction over Ni/silicon wafer at low pressures.

• 한국식품위생안전성학회지
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• 제15권3호
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• pp.179-185
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• 2000

소르빈산등 14종류의 보존료가 사용된 식품소비량과 식품첨가물의 최대허용량을 이용하여 보존료 섭취에 대한 안전성을 평가하고, 보존료 중 더욱 정밀한 섭취량 조사가 필요한 품목을 선별하였다. 가장 섭취량이 많은 보존료는 안식향산 및 안식향산나트륨으로 총 섭취량은 안식향산으로서 85.65mg이며 1일 섭취허용량에 대한 1일 추정섭취량의 비율은 31%이며 특히 청량음료로부터 안식향산의 섭취량이 가장 많은 것으로 추정되었다. 소르빈산 및 소르빈산칼륨으로 총 추정 섭취량은 76.61mg이며 1일 추정섭취량은 1일 섭취허용량의 5%이다. 나머지 보존료의 1일 추정섭취량은 1일 섭취허용량에 대한 비율이 2%이하로 현재 사용되고있는 보존료의 섭취수준은 안전한 것으로 평가할 수 있었다.

• Journal of Pharmaceutical Investigation
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• 제22권4호
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• pp.289-300
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• 1992

The counter-transport phenomena in the hepatic transport of 1-anilino-8-naphthalene sulfonate (ANS) were kinetically investigated by analyzing the plasma disappearance-time profiles and the transport into the isolated hepatocytes. In vivo "counter transport phenomena" were simulated based on the perfusion model which incorporated the carrier-mediated transport and the saturable intracellular binding. The condition that the mobility of carrier-ligand complex is greater than that of free carrier is not essential for the occurrence of counter-transport phenomenon. To examine the inhibitory effects on the initial uptake of a ligand by the liver, it is necessary to judge whether the true counter-transport mechanism (trans-stimulation) is working or not. The initial plasma disappearance curves of ANS were then kinetically analyzed based on a two-compartment model, in which the ligand is eliminated only from the peripheral compartment (liver compartment). No effects on the initial plasma disappearance rates of ANS were observed after preloading of bromophenol blue (BPB) or rose bengal (RB) in the liver. Inhibitory effect of BPB or RB on the initial uptake (or efflux) rates of ANS by the isolated hepatocytes were not observed, suggesting that the true counter transport mechanism is not working. In conclusion, checking the preloading effects of transstimulation on the initial uptake of a ligand by the liver could be a useful criterion for carrier cycling and common use of the same carrier between two ligands. However, one cannot exclude those possibilities even if the preloading effects cannot be observed.