• 대한기계학회논문집B
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• 제33권10호
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• pp.783-788
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• 2009

In this paper, we have performed a parametric study on the characteristics of multiphase laminar flow with density difference in various microchannels. The interface between multiphase fluids is rotated by the gravitational forces induced by density difference. The numerical simulations were carried out via commercial CFD package to study the characteristics of multiphase laminar flow. The results of the numerical simulations in this study were verified by comparing with the previously reported experimental results in the literature. We have also proposed a new dimensionless relationship between dimensionless rotation angle of interface and dimensionless parameters are proposed for square microchannels with various aspect ratios. The dimensionless relationship could be widely applied to the reliable design of various microfluidic devices dealing with multiphase laminar flow.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2007년도 제34회 KOSCO SYMPOSIUM 논문집
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• pp.47-53
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• 2007

The laminar combustion characteristics of interacting coal particles in a convective flow are numerically investigated at particle arrangement and size difference. The numerical simulations, which use the two-step global reaction model to account for the surrounding gas effect, show the detailed interaction among the inter-space particles, undergoing devolatilization and subsequent char burning. Several parametric studies, which include the effect of the gas temperature (1700 K), high pressure(10 atm) and variation in geometrical arrangement of the particle diameter on the volatile release rate and the char combustion rate, have been carried out. The comparison indicates that the shift to the multiple particle arrangement resulted in the substantial change of the combustion characteristics and that the volatile release rate of the interacting coal particles exhibits a strong dependency on the particle spacing and size difference.

• 대한인간공학회지
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• 제17권2호
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• pp.25-32
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• 1998

A combined PC and TV monitor has been developed in several companies. The characteristics of physical user interface in this monitor are likely to vary from existing monitors. Therefore, two experiments to investigate the physical interface characteristics of this monitor were conducted. The first experiment was to investigate the characteristics of color perception with monitor coating (coating vs. non-coating) and screen brightness (30fL vs. 35fL) in the PC mode. The second experiment was to investigate the characteristics of luminance contrast with monitor coating and image movement (static vs. dynamic) in the TV mode. Twenty-three subjects (male 12, female 11) were participated in this experiment. In the first experiment, average color temperatures were obtained in all experimental conditions. There was a significant difference between coating and non-coating screen at 0.1 level. In the second experiment, average luminance contrasts were obtained in all experimental conditions. There was a significant difference between coating and non-coating screen at 0.05 level. In addition, there was a significant difference between static picture and dynamic picture at 0.1 level.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.946-969
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• 2003

Vibration analysis for a coupled MEMS gyroscope design is presented in this paper. MEMS gyroscopes have shown that slight mistuning in fabricated process often leads to significant difference of vibration characteristics between expected and real designs. The difference frequently affects the MEMS gyroscope design in a negative way. As long as the coupling between excited and sensed motions exists, such difference occurs inevitably. In this paper, dimensionless parameters that govern the vibration characteristics of coupled MEMS gyroscope are identified and the effects of the parameters on the vibration characteristics are investigated for the design of the MEMS gyroscope.

• 한국소음진동공학회논문집
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• 제14권8호
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• pp.655-660
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• 2004

Vibration analysis for a coupled MEMS gyroscope design is presented in this paper. Slight mistuning in fabricated MEMS gyroscopes often leads to significant difference of vibration characteristics between expected and real designs. This difference frequently results in a negative effect to the MEMS gyroscope performance. As long as the coupling between excited and sensed motions exists, such difference inevitably occurs. In this paper, dimensionless parameters that govern the vibration characteristics of coupled MEMS gyroscope are identified and the effects of the parameters on the vibration characteristics are investigated.

• 기본간호학회지
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• 제12권2호
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• pp.247-254
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• 2005

Purpose: This study was done to examine the sleep pattern of ICU patients, as well as characteristics of, and factors related to sleep disturbances, and state anxiety. It was done to provide the basic data fur effective nursing interventions to improve quality of sleep for these patients. Methods: The participants were 104 patients who were admitted to the surgical ICU in a hospital in Seoul. To measure sleep patterns, the Verran and Snyder-Halpern Sleep Scale and the Sleeping Scale developed by Oh et al.(1998) were used. Characteristics of sleep disturbances were measured using the Sleep characteristics scale developed by Park(1999). To measure factors related to sleep disturbances, thirty items developed by Oh(1998) were used. Results: There was no statistically significant difference in the sleep patterns according to the general characteristics of the patients. The characteristics of sleep disturbances showed statistically significant differences in general and specific characteristics of sleep patterns but there was no statistically significant difference according to the general characteristics of the patients. There were significant negative correlations between factors related to sleep disturbances and general and specific characteristics of sleep patterns but there were no statistically significant difference according to the general characteristics of the patients. Conclusion: The results showed that the majority of patients staying in the surgical ICU experienced sleep disturbances and that the physical factor was the major factor of sleep disturbances.

• 한국병원경영학회지
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• 제4권2호
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• pp.131-161
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• 1999

This study is to analyze the reason of Breakdown of collective bargaining caused by the difference of main issue about bargaining and other factors influencing collective bargaining from the viewpoint of both labor and capital in Korean medical system. Korean medical system is facing the huge change of medical policy, so it should pursue institutional change following the change of medical system, On the contrary, the activity of labor union in medical system is more organized, activated, so understanding and cooperating on the related policy between labor and management are necessary. As the method of administration participation is collective bargaining, main issues between labor and management may lead Brwakdown of bargaining, so the author will analyze it from three viewpoints. First, the difference of recognition between labor and management due to the characteristics of hospital Secondly, the difference of recognition between labor unions due to the characteristics of hospital Thirdly, the difference of recognition between the characteristics of hospital and labor union.

• Journal of the Korean Wood Science and Technology
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• 제17권1호
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• pp.12-21
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• 1989

This experiment was executed to investigate the characteristics of gloss and color difference in coated films by N.C. Lacquer, Aminoalkyd, Polyester. and Polyurethan coating after chemical (distilled water, ethyl alcohol. acetic acid, and sodium hydroxide) and heating ($120^{\circ}C$) treatments, cold-check test, and U.V. radiation. The results obtained were summarized as follows 1. The gloss decreasing rate by water resistance test was the least among chemicals treated on coated films. 2. The color difference of coated films chemical treatments highly and similarly increased, except the alkali treatment showing a little increase. 3. In the color difference by U.V. radiation, the polyester coated film showed generally large difference compared with the other coated films.

• International Journal of Advanced Culture Technology
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• 제6권4호
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• pp.71-79
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• 2018

For 299 patients who had undergone cataract surgeries we investigated the difference in visual acuity and refractive power before and after cataract surgery and the clinical change of the visual acuity and the refractive power according to age, gender, hospital visit time and specific medical history. We found the factors affecting preoperative and postoperative outcomes of the cataract patients in metropolitan hospitals by input, process, and outcome and analyzed medical characteristics and patient characteristics as the input variables. T-test and ANOVA have been performed for statistical analysis of functional status, and general status and the technical characteristic as the process variable and the outcome variable of diagnosis. Visual acuity improved significantly in patients who had undergone cataract surgery. However, the change in refractive power did not show a statistically significant difference but only a slight difference. The improvement of male patients was greater than that of female patients. The difference in age was more effective in patients under 50 years old and the effect of cataract surgery was relatively high in patients without the presence of specific medical history. Cataract surgery did not seem to help all of the patients, but it is more effective in improving visual acuity and refractive power. We conclude that simultaneous cataract surgery in both eyes is reasonable in order to have at least the better effect.

• 한국의상디자인학회지
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• 제17권1호
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• pp.131-140
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• 2015

After drawing the sensory images from the color green, the difference of sensory images and the difference of the color green according to demographic characteristics and which factors affect the preference have been analysed. The thirty six-photos of 2013 women fashion show on the STYLE.COM were used for the stimuli of green colour fashion for the questionnaire. The people surveyed were adults in their 20s to 50s. The 123 copies of the questionnaire were used for the statistical analysis of this study. Factor analysis, Cronbach's ${\alpha}$ test, t-test, ANOVA, Duncan test and Regression analysis test were carried out by SPSS 19 for the statistical analysis of collected data. The results were as follows. The sensory images of green fashion were drawn in six types. The sensory images of green fashion according to demographic characteristics showed a significant difference depending on martial status, age, monthly income and occupation. The preference of green colour fashion according to demographic characteristics showed a significant difference depending on sex, age, monthly income, occupation. The variables affecting the preference of green fashion were identified as four types, and the most affecting variable to the preference was the favorable and familiar factor. These research results will become available on selecting the target customer and making the marketing differentiation strategy when planning fashion products.