• Journal of Technology Innovation
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• v.2 no.1
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• pp.170-190
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• 1994

The importantce of a development of competitiveness in domestic construction industry is growing as some of domestic construction markets is scheduled to open to foreign competing firms with higher level of construction technology and management. A national level of competitiveness in domestic construction industry and firms are partially, but significantly, affected by a technology level and a characteristics of production pattern. The purpose of the study is mainly to analyze and identify a technology level, production pattern and a development stage of R&D activities of domestic construction industry and firms. Based on these findings the study draws on a concluding remarks and derives technology policy implications. Results of analysis in the study impliy that (1) competitiveness of domestic construction firms(industry) in terms of technology level is relatively weak as compare to that of advanced foreign competing firms, (2) degrees of substitution of capital for labor are seemed to be relatively high, (3) R&D (investment) activities of domestic construction firms are generally spread out in forms of import, adjustment and betterment, and (4) only a small number of big domestic construction firms are seemed to afford to R&D investment for research facilities and equipments, but not enough for higher level of R&D man-power. The study suggests that technology policy for construction industry should be based on a fundamental policy directions. For example the increase in size and heightened quality level of R&D man-power should be placed in a top priority in policy agenda. Sound and specific policy items should be developed for planning and design, and maintenace and inspection technology in order to lead domestic industry to compete with foreign firms with full strength.

• Membrane Journal
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• v.30 no.2
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• pp.138-148
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• 2020

The purpose of this study was to identify the cleaning efficiency of fouled multi-bore hollow fiber membranes after purification of contaminated water. The PSf (polysulfone) based hollow fiber membrane manufactured by Pure & B Tech Co., Ltd. Was used in this study. The antifouling characteristics during the water treatment were studied using bovine serum albumin (BSA) as a model compound and the chemical resistance was evaluated after long-term impregnation in sodium hypochlorite (NaOCl) solution and Citric acid to understand the long term stability of the membranes. Water permeability and mechanical strength of the membranes after prolonged chemical exposure was measured to observe the change in mechanical stability and long term performance of the membrane. moreover, the recovery efficiency was also evaluated after chemical enhanced backwashing of a membrane contaminated with bovine serum albumin. The PSf hollow fiber membrane exhibited excellent chemical resistance, and it was confirmed that the efficiency of sodium hypochlorite was high as a result of chemical enhanced backwashing.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.2
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• pp.200-208
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• 2005

In this study, a new submerged membrane bioreactor process packed with granular sulfur (MBR-GS) was operated to identify the biological nitrogen removal behaviors with plating wastewater containing high-strength $NO_3{^-}$ concentration. The continuous denitrification was carried out at $20^{\circ}C$ with various nitrogen loading rates using synthetic wastewater, which composed of $NO_3{^-}$ and $HCO_3{^-}$, but also actual plating wastewater, which was collected from the effluent of the H metal plating company. As a result, high-rate denitrification in the range of $0.8kg\;NO_3{^-}-N/m^3\;day$ was accomplished at nitrogen loading rate of $0.9kg\;NO_3{^-}-N/m^3\;day$ using synthetic wastewater. Also, higher-rate denitrification with actual plating wastewater was achieved up to $0.91kg\;NO_3{^-}-N/m^3\;day$ at the loading rate of $1.11kg\;NO_3{^-}-N/m^3\;day$. Additionally, continuous filtration was possible during up to 30 days without chemical cleaning in the range of 20 cmHg of transmembrane pressure. On the basis of the proposed stoichiometry, ${SO_4}^{2-}$ production could be estimated efficiently, while observed alkalinity consumption was somewhat lower than theoretical value. Consequently, a new process, MBR-GS is capable of high-rate autotrophic denitrification by compulsive flux and expected to be utilized as an alternative of renovation techniques for nitrogen removal from not only plating wastewater but also municipal wastewater with low C/N ratio.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.11
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• pp.833-839
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• 2014

The shooting noise caused by shooting training, which has strength and impacts, is becoming a serious damage to the residents around the shooting range and, consequently, the number of civil appeals against the shooting noise is on the constant increase. For this reason, the military examines the effects of the shooting noise at the stage of design in constructing a shooting range and tries to build a soundproof shooting range to minimize civil appeals. However, the lack of research and data concerning propagation and attenuation, both of which characterize the shooting noise from within a soundproof shooting range, even makes it so difficult to design a soundproof shooting range in constructing it. So this study used an acoustic simulation in a soundproof shooting range to identify acoustic and propagation characteristics within the shooting range and, on this basis, predicted the noise level at an exit of the soundproof shooting range. As a result, if the form and specifications of a soundproof shooting range were decided on at the stage of design, it was possible to use a simulation to design a soundproof shooting range with optimized acoustic performance and, on this basis, to predict a sound pressure level at an exit of the soundproof shooting range. On the basis of these data, it is probably possible to determine the degree of the effects of the shooting noise on the villages around a shooting range and the extent of damage to it and to minimize civil appeals against the shooting noise and resolve the issues of compensation and agreement with ease. This study is expected to provide useful data for designing and constructing a similar soundproof shooting range.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.1
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• pp.26-35
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• 2017

The high-cycle fatigue cracking and the resonance generated in operation of a centrifugal compressor are main cause of the impeller damage. In order to prevent the damage, the impeller is designed or modified to have sufficient strength to withstand the operating condition. The damage prevent design will lead to a change of the flow condition and the performance characteristics of the compressor. In this study, the computational analysis were performed to identify the flow and the performance characteristics. The cases are a scalloped and a increased the blade thickness models with a closed type impeller. As the analysis results, the value of head coefficient and total to total efficiency for the increased the blade thickness model was decreased by each 0.5% and 0.1% than the values of the baseline model. Each value for the scalloped model was increased by 0.4% and was decreased by 1.6%.

• The Journal of Korean Obstetrics and Gynecology
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• v.28 no.3
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• pp.74-86
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• 2015

Objectives To identify whether Sovereign-Minister-Assistant-Courier (君臣佐使) Theory and Meridian Tropism (歸經) Theory of oral herbal medicine can be applied to trans-dermal medicine and whether pharmaceutical efficacy can be delivered to skin by Courier herb (使藥). Methods We reviewed previous studies related to Sovereign-Minister-Assistant-Courier Theory. And we examined whether prescription compositions based on Sovereign-Minister-Assistant-Courier Theory correspond with efficacy results of trans-dermal medicine experimentally identified. Results When Sovereign-Minister-Assistant-Courier Theory is applied to trans-dermal medicine, Courier herb act as delivering the effective components to the lesion penetrating skin barrier. And we identified that medicine absorbed through the digestive processes may not correspond with Courier herb applied topically. Conclusions We identified that Courier herb act as delivering the effective components to the lesion. But to strength evidences, additional studies on this action will be needed.

• Industry Promotion Research
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• v.6 no.4
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• pp.1-9
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• 2021

The purpose of this study is to manufacture lightweight aggregates for recycling water treatment sludge, to identify the physical properties of the aggregates, and present a method of utilizing the manufactured lightweight aggregates. The chemical composition and thermal properties were examined via a raw materials analysis. The aggregate examined here was fired by the rapid sintering method and the single-particle density and water absorption rate were measured. Water treatment sludge has high ignition loss and high fire resistance. When 30wt% of purified sludge was added, the single-particle density of the aggregates was in the range of 0.8~1.2g/cm³ at a temperature of 1,150~1,200℃. At temperatures of 1200℃ or higher, ultra-light aggregates having a single-particle density of 0.8 or less could be produced. When applied to concrete by replacing the general aggregate in the concrete, a specimen having strength values of 200 to 450 kgf/cm² on 28 days was obtained, and when applied as a filter material, the performance was equal to or higher than that of ordinary sand.

• Journal of Convergence for Information Technology
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• v.11 no.7
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• pp.155-163
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• 2021

This study was conducted to identify factors that affect the life satisfaction of college students. The subjects of this study were 191 students from three universities located in one area, and the data collection used self-reported questionnaires. Data analysis was performed using frequency, percentage, mean, standard deviation, Independent T-test, One-way ANOVA, Pearson Correlation Coefficient, and Multiple Regression Analysis. The results of the study showed that significant factors affecting the life satisfaction of the subjects were self-esteem and school life satisfaction, and the explanatory power according to the influence factors was 42.3%. The research results suggest that improving college students' self-esteem and school life satisfaction can help them improve their life satisfaction. Therefore, it is necessary to consider self-esteem and school life satisfaction when developing educational programs to improve the life satisfaction of college students in the future.

• Journal of the Korea Convergence Society
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• v.10 no.6
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• pp.243-249
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• 2019

This study was conducted on elderly women in their 60s and 70s, and the results of the study were as follows when line dancing for 60 minuctes every three times a week for 12 weeks on dementia and aging-related hormones. After 12 weeks of line dancing programs, BDNF, DHEA-s, and estrogen increased, but no statistically significant differences with control groups emerged. In addition, after 12 weeks of line dancing, Apolipoprotein B decreased in line dancing group but showed no statistically significant difference from control group. Although significant differences between groups were not identified in the results of this study, positive effects on preventing and aging of dementia were identified in the group applying the line dance program, and further studies considering the new target and hign kinetic strength, frequency, time, and athletic genre are needed to identify the distinct effects of line dancing in the future.

• 재활복지
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• v.22 no.3
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• pp.1-22
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• 2018

The purpose of the study was to identify available evidence related to physical activity interventions that were effective to improve health-related physical fitness levels of children and youth with disabilities. Studies were accumulated from multiple databases (i.e., ERIC, Child Development & Adolescent Studies, MEDLINE, SPORTDiscus with Full Text, and CINAHL Plus with Full Text). From the initial process, 1195 articles were identified and of those, 13 studies (n = 13) were analyzed. Based on the results, community-based physical activities were the most common environment of interventions followed by school-based and home-based. Further, the most improved health-related physical fitness outcomes were muscular strength, muscular endurance, and cardiorespiratory endurance while limited evidence on weight reduction was available. There is a need for more research on physical activity intervention which particularly improves health related physical fitness of children and youth with disabilities.