• Korean Chemical Engineering Research
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• v.47 no.6
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• pp.720-726
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• 2009

Hydrodynamic similarity was investigated in pressurized three-phase slurry bubble columns by selecting the bubble holdup and pressure drop as objective functions, for the effective design and scale-up of it. In addition, effects of operating variables on the bubble holdup with variation of column diameter were also analyzed. Gas velocity($U_G$), viscosity(${\mu}_{SL,eff}$) and surface tension(${\rho}_{SL}$) of slurry phase, density difference between the slurry and gas phases(${\rho}_{SL}-{\rho}_G$) depending on the operating pressure, pressure drop per unit length(${\Delta}P/L$), column diameter(D) and gravitational acceleration(g) were chosen as governing parameters in determining the bubble holdup and pressure drop in the column. From the dimensional analysis, four kinds of dimensionless groups were derived from the 7 parameters and 4 fundamental dimensions. Effects of dimensionless groups such as Reynolds, Froude and Weber numbers on the bubble holdup in the column were discussed. The pressure drop and bubble holdup could be predicted from the correlation of dimensionless groups effectively, which could be used as useful information for the design and scale-up of pressurized slurry bubble columns.

• Journal of the Korea Fashion and Costume Design Association
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• v.17 no.3
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• pp.85-98
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• 2015

Modern fashion shows the trend of various styles and the period focusing on only product functions is changed to the period focusing on consumer's sensibility. Consumers show different sensitivities and preference by individual at the stage cognizing and recognizing the stimulation of given image and the method of objective measurement based on the fashion sensible vocabularies is necessary to measure fashion sensibility. Therefore, this research is significant to examine differences of preference to classic fashion by generation and awareness for sensible vocabularies and suggest methodology of design sensible evaluation research through the quantitative evaluation objectifying subjective sensibility. For the method of research, precedent theses related to classic, concept and characteristics of classic in books and definition and characteristics by generation were examined, the best 3 domestic portal sites were selected and adjective vocabularies and images related to classic were collected from 2010 to 2014. Among the 206 adjectives collected, vocabularies whose average is more than 3.5 were drawn by 5-point Likert scale for fashion expert group. And, among the total 306 images collected, 21 representative images were selected by preliminary investigation of fashion expert group. For the classic images and vocabularies selected, frequency analysis, factor analysis and variance analysis were conducted by SPSS 19.0. The results of analysis are as follows. Preference to classic fashion image by generation was analyzed. As a result, both of two generations selected classic fashion as the most classic one. The images of the next orders were analyzed. As a result, Y generation selected basic classic fashion image which is casual with high activity as a classic one. Baby boom generation selected ancient classic fashion image, so there were differences in preference for classic by generation. As a factor analysis on classic adjective vocabularies, they could be divided into 5 factors such as basic form, attractive form, traditional form, vintage form and active form and they verified that credibility of all measuring variables for classic sensible vocabularies was achieved. Differences of classic sensible vocabularies by classic fashion image and generation were examined. As a result, generation and classic fashion image made a significant effect on five factors. Therefore, there were differences of the awareness on classic fashion images and sensible vocabularies among the generations and this thesis can be a fundamental material which objectifies subjective sensibility and suggests the methodology of new research.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.6 no.2
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• pp.166-176
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• 1996

The fundamental conditions for growing $CsLiB_{6}O_{10}$ crystal, new nonlinear optical material, were investigated. Stoichiometirc mixture of $CsLiB_{6}O_{10}$ composition resulted in the crystal of the same composition in the process of heating at the temperature above $600^{\circ}C$. No phase transition was observed in the $CsLiB_{6}O_{10}$ crystal in the temperature range of $600^{\circ}C~800^{\circ}C$, and $CsLiB_{6}O_{10}$ crystal melted congruently at $850^{\circ}C$. When the melt of this composition was cooled at rates of $1~150^{\circ}C/hr$, glass state ingot was formed regardless of cooling rates. However, $CsLiB_{6}O_{10}$ crystals were formed directly from the melt at any cooling rate in the presence of $CsLiB_{6}O_{10}$ seed crystal in the melt. Transparent $CsLiB_{6}O_{10}$ single crystal was grown from the melt using the seed crystal at the growing rate of 0.06 mm/hr in the furnace having the temperature gradient of $100^{\circ}C/cm$. Analysis of the single crystal showed that the crystal belonged to the noncentrosymmetric tetragonal space group 142d and unit cell dimensions were $a=10.467(1)\;{\AA},\;c=8.972(1)\;{\AA}\;and\;V=983.0(2)\;{\AA}^3$. Optical absorption edge of the crystal was observed at 180mm and the crystal showed a good optical transparency (70% transmittance, sample thickness 0.5 mm) in the wide wavelength range above 300 nm.

• Journal of the Korean Society of Radiology
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• v.14 no.5
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• pp.651-660
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• 2020

The purpose of this study was to create a phantom with a HU value similar to that of the human Femur using a 3D printer to replace the existing pig bone. A total of 372 people were analyzed to determine the HU value of human Femur. Using a 3D printer, a human bone model phantom was fabricated using PLA-Cu 20% and subjected to CT examination. Pig bones were 6 months old pigs, and bones 2 days after slaughter were used. As a result of the examination, the 3D printing phantom made with 80% of the internal filling showed a similar value to all data of the human body (p<0.05), and there was a difference from the pig bone (p>0.05). In addition, in the case of the HU value of Femur by age group, it was confirmed that the value of HU decreased as the age group increased (p<0.05). 3D printing and HU values confirmed a weak negative correlation with respect to the stacking height, but confirmed a strong positive correlation (R² = 0.996) with 182.13±1.290 in the inner filling (p<0.05). In conclusion, it was confirmed that the human body model phantom using 3D printing can exhibit a similar level of HU value to the human body compared to the existing pig bone phantom, and this study will provide basic data for the production of a human body model phantom using a 3D printer.

• Korean Journal of Applied Biomechanics
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• v.23 no.4
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• pp.285-294
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• 2013

The purpose of this study was to provide fundamental information for success factors of techniques through kinematic analysis including coordination of lower extremities and landing stability according to the success and failure of $540^{\circ}$ Dwihuryeochagi in Taekwondo. Twenty Taekwondo athletes: ten success group (S, age: $22.3{\pm}1.8$ yrs, height: $172.1{\pm}5.4$ cm, body mass: $64.4{\pm}4.2$ kg) and ten failure group (F, age: $22.3{\pm}1.8$ yrs, height: $172.1{\pm}5.4$ cm, body mass: $64.4{\pm}4.2$ kg) participated in this study. Three-dimensional motion analysis using a system of 3 video cameras with a sampling of 60 fields/s was performed during the competition of $540^{\circ}$ Dwihuryeochagi. Motions were divided into five events: pivot foot landing (E1), pivot foot toe off (E2), COM max height (E3), kick impact (E4) and landing (E5). At E1, the stride width was greater for S than for F (p<.05) while the time was greater for S than for F during P4 (p<.05). At E4, knee angle was greater for S than for F (p<.05). At E5, hip angle was greater for S than for F (p<.05) while kick distance was greater for S than for F (p<.05). Furthermore, at P3, the time would be related to kicking velocity (p<.05), while at P4, the time, range of hip angle and knee angle would be related to kick distance (p<.05). At P1, COM horizontal velocity would be related to COM vertical velocity of P1 and P2 (p<.05). Based on the findings, success factors of $540^{\circ}\acute{y}$ Dwihuryeochagi were COM horizontal velocity of P1, COM vertical velocity of P2, the time, kick distance, velocity, angle of lower extremities and coordination of P3-P4.

• Journal of the Korean School Mathematics Society
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• v.17 no.3
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• pp.359-384
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• 2014

The purpose of this study is inquire the reaction and adaptability of the mathematically gifted student, in the case of introduce learning materials based on GeoGebra in real class. The study program using GeoGebra consist of 'construction of fundamental figures', 'making animation with using slider tools' (graph of a function, trace of a figure, definite integral, fixed point, and draw a parametric curve), make up the group report after class. In detail, 1st to 15th classes are mainly problem-solving, and topic-exploring classes. To analyze the application effects of developed learning materials, divide students in four groups and lead them to make out their own creative products. In detail, guide students to make out their own report about mathematical themes that based on given learning materials. Concretely, build up the program to make up group report about their own topics in six weeks, after learning on various topics. Expert panel concluded that developed learning materials are successfully stimulate student's creativity in various way, after analyze of the student's activities. Moreover, those learning programs also contributed to the develop of the mathematical ability to thinking that necessary to writing a report. As well, four creative products are assessed as connote mathematically gifted student's creative thinking and meaningful elements in mathematical aspects.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.537-544
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• 2020

Beef consumption trends are changing according to consumer needs and preferences. This study was conducted to collect the fundamental information by investigating the consumer's preference and purchase propensity of beef(Hanwoo beef) for improvement of Korean beef grading system. Consumers were recruited from Seoul, Gyeonggi-do, and 5 metropolitan cities, and surveyed from July 24 ~ August 14, 2017. The data obtained from 362 consumers were finally selected for the verification process. Results from the Hierarchical Regression Analysis reveal that the increased purchasing frequency is positively correlated with the following factors, in the consumer group showing preference in the Quality Grade (QG) of beef: marbling type 1QG, fat color 1⁺QG, and income, grade opinion, marbling contents and type 1⁺⁺QG. Conversely, no factor affected the increased purchasing frequency in the consumer group having no preferred QG for beef (p>0.05). Our study determined significant differences in the factors affecting increased purchase frequency of beef among the different groups, classified depending on their preferred QG. The grading system is important since it directly correlates with profit for livestock farmers and the industry. We therefore propose that the grading criteria need to be revised reasonably but scientifically, considering various opinions of the producers and consumers.

• Korean Journal of Community Nutrition
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• v.20 no.2
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• pp.109-119
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• 2015

Objectives: The purpose of this study was to compare and analyze the results of salty taste assessment, dietary attitudes, and dietary behaviors among adult and senior women by region and by age. The results generated from this was expected to provide fundamental data for implementing a nationwide salt reduction education program. Methods: The salty taste assessment tool was applied to 4,064 subjects from 15 areas in Korea. Also, a survey of dietary attitude and dietary behavior related to salt intake was conducted for all subjects participated in this study. Results: The salty taste assessment scores by region and by age were the lowest in capital (p < 0.01) and was highest among the 70+ year age group (p < 0.01). The dietary attitude scores and dietary behavior scores showed that Gyeongsang was the highest (p < 0.001) and the capital was the lowest. The dietary attitude scores were highest at 20&30's followed by 40's and 70's group (p < 0.001). Dietary behavior scores showed that 20's~30's and 40's groups were higher than the other age groups (p < 0.001). The score of 'I like kimchi' was $3.46{\pm}0.88$, which was the highest among 10 dietary behavior questions. The score of 'I eat a lot of kimchi' was $3.30{\pm}0.90$, which was the highest among 10 dietary behavior questions related to salt intake. The scores of salty taste assessment had significant positive correlations between the scores of dietary attitude (p < 0.001), dietary behavior (p < 0.001) and self-awareness (p < 0.001). Conclusions: Based on the results of salty taste assessment, we observed a tendency that older people and regions except the capital had higher preference for salty taste. Our results suggested the necessity for a nationwide salty reduction education program tailored for regions and for different age groups.

• Korean Journal of Social Welfare
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• v.56 no.2
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• pp.261-283
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• 2004

This study verified the effectiveness of brief family education programs for schizophrenic outpatients and their families in a community social welfare center, using a pre - post test control group design. The results of this study verified that the program was effective to improve knowledge about schizophrenia, reduce feelings of rejection and anxiety about patients, and help the patients to recognize their family emotional support. Therefore, it was found in this study that the brief family education program in the community social welfare center had a positive impact on schizophrenic outpatients and their families' treatment and rehabilitation. From the results of this study, it can be seen that this program positively effects the treatment and rehabilitation of schizophrenic patients and the stability of their families. The program can also be easily utilized as a community resource. Furthermore, the results of this study can be utilized as fundamental support to suggest the need for mental health programs in community social welfare centers. This study suggested the importance of increasing the number of mental health professionals working in this arena. There is also a need to create additional supportive programs for schizophrenic outpatients and their families. Follow up care also needs to be provided to families after completing family education programs. Continuous study is needed in these areas.

• Journal of the Economic Geographical Society of Korea
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• v.12 no.4
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• pp.627-644
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• 2009

In the knowledge-based economy highlighting the importance of human capital, there has been a growing interest in human capital externalities as a fundamental engine of growth and development of a region. The purpose of this study is to analyze human capital externalities using 3-level hierarchical linear model(3-HLM), decomposing determinants of wages into three levels involving workers(level-1) nested within firms(level-2) nested within regions(level-3). This study separately estimates the effect of the average education level on the wages by three different schooling groups on the assumption that the intensity of knowledge spillovers varies with each group's schooling level. The main results are as follows; First, the coefficient of the average education level of a region shows 0.044, indicating that one-year increase in the average level of schooling could increase average individual earnings by 4.4%. Secondly, the external effects of human capital on three different schooling groups are considerably different, raising less than high school graduates' wages by 3.0%, college graduates' wages by 4.7%, and graduate schools' wages by 11.8%, respectively. Thirdly, well educated workers are much more sensitive to the variation of the regional education level than less educated ones when we apply the shares of each schooling group as alternative measures for the average level of education. Such findings of this study draw an implication that local governments could speed up regional economic growth in the knowledge-based economy by not only raising total human capital stock in a region but building the close networks that promote productivity-enhancing human capital external effects.