• Journal of the Optical Society of Korea
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• v.11 no.4
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• pp.183-191
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• 2007

The highest diffraction efficiency(DE) value after illumination and post-curing of photopolymer films were obtained at the $SeO_2$/Acrylamide(AA) Ratios of AA 3.0 g, $SeO_2$ 1.0g and the DE's were stable values of over 90%. By the addition of $SeO_2$, the maximum DE at the initial stage of illumination was reached at 300 seconds, which suggests $SeO_2$ slows down the photopolymerization of AA, which enhances the maximum DE value by giving more migration time. DE variation curve for the optimum composition during extended-time illumination of 9,000 seconds resembles a sine curve due to the combination of the monomer diffusion and the photopolymerization, and the photopolymer film expanded by about 8% after photopolymerization due to monomer migration.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.821-824
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• 2008

This paper presents a systematic approach for estimating material performance of concrete mixture design based on satisfaction curves developed from statistical evaluation of existing or newly obtained material property related data. In performance based material design (PBMD) method, concrete material used for construction of a structure is designed considering a structure's specified performance requirements based on its usage and characteristics such as environmental conditions, structure types, expected design life, etc.Satisfaction curves express the probabilities that one component of substrates (i.e., aggregate size, cement content, etc) of concrete mixture will sustain different criterion value for a given concrete mixture design. This study presents a statistical analysis method for setting up concrete material parameter versus concrete criterion relationships in the form of satisfaction curves and for estimating confidence bounds on these satisfaction curves. This paper also presents an analysis method to combine multiple satisfaction curves to form one unique satisfaction curve that can relate the performance of concrete to a single evaluating value. Based on several evaluated mixture design examples for various material properties, the validity of the proposed method is discussed in detail.

• Journal of the Korean Data and Information Science Society
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• v.25 no.4
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• pp.903-914
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• 2014

The inverse Weibull distribution has been proposed as a model in the analysis of life testing data. Also, inverse Weibull distribution has been recently derived as a suitable model to describe degradation phenomena of mechanical components such as the dynamic components (pistons, crankshaft, etc.) of diesel engines. In this paper, we derive the approximate maximum likelihood estimators of the scale parameter and the shape parameter in the inverse Weibull distribution under multiply type-II censoring. We also develop four modified empirical distribution function (EDF) type tests for the inverse Weibull or extreme value distribution based on multiply type-II censored samples. We also propose modified normalized sample Lorenz curve plot and new test statistic.

• Journal of Surface Science and Engineering
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• v.27 no.6
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• pp.340-346
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• 1994

The method of uniforming current distribution in Hull cell are studied by using auxiliary anode, current shield bipolar electrode, and combinings bipolar electrode with current shield in order to find a way of uni-form deposition. The current density distributions are measured by each ammeter of the same inner resistance connected to divided cathode pannel respectively. The current density distributions of cathode electrode divided into five sections with 5mm width have a tendency of linear inclination, and that of twenty sections have a tendency of smoother curve than the curve of original Hull cell pannel. Their results showed lower value on the high current density portion and higher value on the low portion than that original Hull cell pannel. The current distribution in Hull cell is able to unify by using auxiliary anode, or combining bipo-lar electrode with current shield, but not efficient in using one of both individually.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.12
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• pp.1200-1209
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• 2010

The main subject of this paper is to develop analytic method with which output power or sensitivity variations of a magnetostrictive ultrasonic transducer can be estimated with no aid of experiments. After the bias magnetic field deployed over the patch is calculated using finite element analysis for magnetostatics, the representative value is extracted by averaging these field values. The operating point on the characteristic curve for magnetostriction is identified by this value and then the output performance is calculated from it. It is verified that the results from this simple model match well with those of its experimental version and some limits of this modeling technique are also considered.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.3 s.52
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• pp.259-263
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• 2005

The aim of the present study is to evaluate relationship between UV-induced MED and perfusion value assessed by Laser Doppler Perfusion Imager. In this study, A increasing linear relationship is seen between perfusion and dose (p<0.05). The dose-response curve show a steep slope in the case of lower MED values group after MED point, For higher MED group, increase with a gentle slope.

• Electrical & Electronic Materials
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• v.9 no.10
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• pp.1013-1018
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• 1996

The annealing effects of Au/Te/Au/n-GaAs structure was investigated by using x-ray diffraction, scanning electron microscope, the specific contact resistance and I-V measurement. Increasing the annealing temperature, the intensity of Au-Ga peak by X-ray diffraction was increased. The Ga$\_$2/Te$\_$3/peak got evident for the samples annealed at 400.deg. C and GaAs peak by recrystallization appeared for the samples annealed at 500.deg. C. The variation from the schottky to low resistance contact was confirmed by I-V curve. The lowest value of the specific contact resistance of the samples annealed at 500.deg. C was 3.8*10$\^$-5/.ohm.-cm$\^$2/ but the value increased above 600.deg. C.

• Journal of Ocean Engineering and Technology
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• v.22 no.1
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• pp.70-74
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• 2008

It is important to reduce the vibration and noise of submarines and ships. For the purpose of noise reduction, various researches are actively being conducted on the employment of complex structures. However, in the case of numerical analysis for complex structures with damping materials, substantial errors can be generated by the absence of an exact damping model. Thus experimental model analysis is necessary for the verification of a numerical analysis for complex structures. In this research, vibration experiments are conducted in order to ascertain the vibration properties of cantilever beam attached damping materials. First, an initial value is obtained by using a direct linear method. Next, based on this initial value, the exact modal parameters of the cantilever beam are obtained by using the Newton-Raphson method.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.3-5
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• 1997

The relation between electric current and magnetic field under three overhead transmission lines being operated was studied. It was examined for a difference each other in comparison with calculated value and measured value for current, magnetic field. With magnetic field equations made out, The magnetic field distribution around transmission lines had made to figure out with easy by load electric current value. Additionally, we are going to describe the distribution curve of magnetic exposure volume for KEPCO's T/L.

• Journal of Haehwa Medicine
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• v.7 no.2
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• pp.609-620
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• 1999

Over the period between January 1997 and December 1998, herbal medicine was more than three times administered to the patients coming to Na dong gyu's Oriental Medical Clinic on account of the symptom of growth deficiency. According to radiological opinions about the patients providing cooperation for measuring their height and weight as well as their bone age every three months, it was found that the growth plates were not closed. A research was conducted for 200 children randomly selected of patients in prepuberty (they grew by less than 5cm a year before treatment at a age of 12years for female children and 14years for male children). As a result, the following conclusion was drawn: 1. The randomly selected subjects were made up of 116 male and 84 female children in terms of gender. The age direstribution was most 10 to 12 years in 86 children(34.00%), followed by 8-10 years(27.50%) and 12 to 14 years(19.50%). 2. Considering the distribution of sick children's parental height, the fathers of 141 children(70.50%) measured less than 170cm high, the subaverage height, while the mothers of 172 children(86%) measured less than 160cm high, the subaverage height. It was shown that sick childen's height was genetically influenced by their parents. 3. Children patients's weight at a time of birth was most 3.1-3.5kg for 85 children(44%) and less than 2.5kg which came under the range of growth dificiency for 19 children(9.5%). 4. The highest proportian of the children patients with growth dificiency(56.33%) had the symptom of digestive disorders, of which 77 children patients(18.78%) had anorexia, 16.59% of children patients had the high level of respiratory disorders. Both the digestive disorder and the respiratory disorder put together, they had the high rate of 72.92%. Therefore, this indicates that both the digestive disorder and the respiratory disorder have a great effect on children's growth dificiency. 10.74% of chilren patients were shown to have allergic disorders, which indicates that they also exert an effect on growth deficiency. Specifically, 7.07% of the children patients had the high level of obesity, which shows that an excessive uptake of nutrition may rather induce children to have growth dificiency though an appropriate amount of nutritional uptake is necessary. 5. Comparing their bone age and their chronological age, 58 children patients(29.00%) showed that they were the same at the highest percent. 79 children patients(39.50%) showed that thier bone age was lower than their chronological age. And 63 children patients(31.50%) showed that their bone age was higher than their chronological age. 6. As regards the prescription administered to children patients for treating their growth dificiency, Growth tang A related to the kidney, the congenital factor, of the causes for growth dificiency in traditional Oriental Medicine was administered to 108 children patients(54%), whereas the Growth tang B related to the spleen, the acquired factor, was administered to 92 children patients(46%). 7. 116 male children patients with growth dificiency had the average value of growth for one year before treatment, 4.39cm, while 84 female children patients had the average value of growth for one year before treatment, 4.24cm. A total of 200 children had the average value of growth for one year before treatment, 4.33cm. The annual average value of growth in growth curve surveyed by the Korea Pediatrics Society was 5.79cm. Compared to this value, the one year average value of growth for 108 male and female children patients taking Growth tang A was shown be 8.44cm, which indicates a greater growth by 4.12cm(95.37%) in comparison with the average value of growth before treatment, 4.32cm, and a greater growth by 2.65cm(45.77%) compared to 5.79cm, the average value of growth in growth curve surveyed by the Korea Pediatrics Society. Also, the average value of growth before treatment for 92 male and female children patients taking Growth tang B was shown to be 8.47cm, which indicates a greater increase by 4.15cm(96.06%) compared to 4.32cm, the average value of growth before treatment and a greater increase by 2.67cm(46.29%) in comparison with 5.79cm, the average value of growth in growth curve surveyed by the Korea Pediatrics Society. Considering the average value of growth for male and female children patients taking Growth tang A and B, it was shown to be 8.46cm, which indicates a greater increase by 4.14cm(95.81%) compared to 4.32cm, the average value of growth before treatment, and a greater increase by 2.67cm(46.11%) compared to 5.79cm, the average value of growth in growth curve surveyed by the Korea Pediatrics Society.