• Journal of The Korean Association For Science Education
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• v.36 no.3
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• pp.499-507
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• 2016

A flipped learning class was held in an attempt to overcome the limits of lecture-type classes in pre-service science teacher training and to provide a student-oriented education suitable for digital native generation. The principles of teaching-learning in flipped learning were applied to the general ADDIE model to design the class; learning materials were developed accordingly. The developed flipped learning materials and class design were verified for their validity using an expert panel's Delphi method and validity test, in which the validity was verified with 0.75 CVR. The developed flipped learning materials were applied to the theory of science education and the instructional effectiveness was analyzed. The results suggest that the students' motivation to study, interest, and confidence in learning increased; however, their satisfaction in class decreased by 30% as compared to the lecture-type class and their self-confidence in the improvement of their academic achievement was not sufficient. In order for a flipped learning class to be successful, the class should be small in size, which would ensure appropriate teacher-student communication and individualized learning; also, the students' burden of learning should be reduced and accessibility to video materials for pre-class learning should be reinforced.

• Journal of Acupuncture Research
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• v.30 no.3
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• pp.39-49
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• 2013

Objectives : The purpose of this study is to assess the effect of Taegeuk acupuncture on reducing mental stress by analyzing heart rate variability in Soeumin. Methods : Six Soeumin-diagnosed men participated in this study. They were randomly divided into group A and group B. Each participant went through 4 sessions every week with 1 week of washout period in between each session. HRV was measured three times at every session; at baseline, after administering mentally stressful circumstances and after applying Soeumin Taegeuk acupuncture or Soyangin Taegeuk acupuncture. This study was designed as a crossover clinical trial. Group A participants were treated with two sets of Soeumin Taegeuk and Soyangin Taegeuk acupuncture treatment in respective order (i.e. Soeumin Taegeuk - Soyangin Taegeuk - Soeumin Taegeuk - Soyangin Taegeuk acupuncture treatment). Group B participants were treated with reverse-ordered acupuncture treatment (i.e. Soyangin Taegeuk - Soeumin Taegeuk - Soyangin Taegeuk - Soeumin Taegeuk acupuncture treatment ). Bayesian analysis was performed by using WinBUGS(Ver. 1.4.3) for comparison between Soeumin Taegeuk acupuncture and Soyangin Taegeuk acupuncture. Results : Overall, Soeumin Taegeuk acupuncture tends to reduce LF/HF ratio, LF, HF, LF(Norm) and increase HF(Norm) more than Soyangin Taegeuk acupuncture, but the difference was not statistically significant. In one participant, however, Soeumin Taegeuk acupuncture reduced LF/HF ratio, LF(Norm) and increased HF(Norm) more than Soyangin Taegeuk acupuncture, and the difference was stastatistically significant. Conclusions : This study suggests that Soeumin Taegeuk acupuncture might be an effective means of stabilizing mental stress-induced imbalance of autonomic nervous system for Soeumin.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.4
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• pp.856-859
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• 2007

We have investigated the antimetastatic and antitumor effects of Ginsenoside Rh2 and ${\beta}-glucan$ unsing an experimental metastatic mouse model intravenously injected with B 16 melanoma F 10 cells. Animal groups are divided into six groups according to the dosage of drug administration and the kind of drugs. The groups are control, ${\beta}-glucan$ with 50, 100 and 200 mg/kg, Geinsenoside Rh2 50 mg/kg, and ${\beta}-glucan$ 50 mg/kg + Ginsenoside Rh2 50 mg/kg. Oral administration of various concentration of ${\beta}-glucan$( 50, 100, and 200 mg/kg) were reduced the lung- metastatics induced by metastatic B16 melanoma F 10 cells injection with a dose dependent manner in the syngenic mice. At same dosage group, Ginsenoside Rh2 (50 mg/kg) has more antimetastatic effect than the ${\beta}-glucan$(50 mg/kg). The highest antimetastatic effects was observed in the ${\beta}-glucan$ 50 mg/kg + Ginsenoside Rh2 50 mg/kg group and has a similar tendency in the anti-tumor effects, including decrease of the average tumor weight and increase of the average survival rate. There are no differences of the average tumor weights were apparent in the ${\beta}-glucan$ groups, however there were little decrease of the average tumor weight in Ginsenoside 50 mg/kg group and ${\beta}-glucan$ 50 mg/kg + Ginsenoside Rh2 50 mg/kg group than that of the control group. The rate of average survival rate in the ${\beta}-glucan$ 50 mg/kg + Ginsenoside Rh2 50 mg/kg group, ${\beta}-glucan$ 200 mg/kg, ${\beta}-glucan$ 100 mg/kg and ${\beta}-glucan$ 50 mg/kg, and Ginsenoside 50 mg/kg groups were highly in order. These data suggest that antimetastatic and antitumor effect of combination of Ginsenodide Rh2 and ${\beta}-glucan$ be the highest in this study.

• Journal of Navigation and Port Research
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• v.29 no.5 s.101
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• pp.389-394
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• 2005

The additional moment occurs because the superstructures of VLFS are influenced by wave loads instead of earthquake loads. In order to reduce the additional moment, this study used the semi-rigid connections which lie between fully rigid and pinned. If the semi-rigid connections are used for superstructures of VLFS, the moment of beams can be reduced and more economical construction will be possible. This study aims to show the effect of wave loads on structure and the efficiency of the semi-rigid connections due to wave loads by analyzing the time history responses. The dynamic behaviors of the rigid frame are compared with those of the semi-rigid frame considering of static loads, wave loads and combination loads for a four-bay, three-story frames. The semi-rigid connection type is a steel tubular column with square external-diaphragm connections and the time history analysis is used for the dynamic responses. The additional moment responses due to wave loads increase $33\%$ in the rigid frame, $26\%$ in the semi-rigid frame with the spring model.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.1
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• pp.17-25
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• 2020

In this study, three-dimensional fluid flow analyses have been performed in order to investigate the performance characteristics of a horizontal axis tidal turbine (HATT) by solving three-dimensional Reynolds-averaged Navier-Stokes equations utilizing the shear-stress-transport turbulence model. The computational domain for the flow analysis has been composed of hexahedral grids, and the grid dependency test has been carried out so as to determine the optimum grid size. Performance characteristics of the HATT have been investigated in consideration of the effects of hub nose geometry, inflow angle, and the tower. It has been found that the power output can be enhanced along with an increase of the ratio of the length to the diameter of the turbine nose, and the power of HATT has been reduced by approximately 10% when the primary fluid flow had an inflow angle of 15°. The power output of downstream HATT is found to be lower than that of the upstream HATT by about 1%.

• Journal of Broadcast Engineering
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• v.15 no.1
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• pp.63-75
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• 2010

In this paper, the equalizer techniques that is able to adopt the digital on-channel repeater for 8VSB-based DTV system has been analyzed and we propose an effective equalizer structure which can reduce the error propagation phenomenon by the feedback signal and improve the receiver performance at the same time. In order to confirm the effective cancellation of the feedback signal, the multi-level Correlation LMS scheme is proposed through the analysis of conventional basic LMS based DFE and Correlation LMS algorithm and as compared with the conventional method, we can confirm the reduction of error propagation. When performing the computer simulation, as the Brazil channel model which is very popular for DTV broadcasting system is adopted, the result is drawn by comparing and analysing the equalizer algorithm. We have examine the symbol error rate which is in the range of 15~25dB of operation receipt SNR and MSE(Mean Square Error) in the DTV broadcasting system. As a result of comparing with the existing method, the signal-noise ratio which is necessary for maintain the bit error correction ability that the means of proposal is same is reduced by about 2~5dB, and in the rate of convergence through the MSE, we found the reduction of needed time.

• Journal of Korea Water Resources Association
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• v.39 no.3 s.164
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• pp.275-288
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• 2006

This study develops ESP (Ensemble Streamflow Prediction) system by using medium-term numerical weather prediction model which is GDAPS(T213) of KMA. The developed system forecasts medium- and long-range exceedance Probability for streamflow and RPSS evaluation scheme is used to analyze the accuracy of probability forecasts. It can be seen that the daily probability forecast results contain high uncertainties. A sensitivity analysis with respect to forecast time resolution shows that uncertainties decrease and accuracy generally improves as the forecast time step increase. Weekly ESP results by using the GDAPS output with a lead time of up to 28 days are more accurately predicted than traditional ESP results because conditional probabilities are stably distributed and uncertainties can be reduced. Therefore, it can be concluded that the developed system will be useful tool for medium- and long-term reservoir inflow forecasts in order to manage water resources.

• Korean Journal of Pharmacognosy
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• v.28 no.4
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• pp.215-224
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• 1997

Gamijiyu-tang (GJT) described originally in the Dong Eui Bo Gam, a traditional reference for oriental medicine in the Korea, has been clinically used for treatment of chronic liver disease. In order to evaluate scientifcally a hepatoprotective effect of GJT in the liver fibrotic disease, the present study investigated how GJT improves a hepatic function in the dimethylnitrosamine (DMN)-treated rat. DMN treatment caused a significant increase of relative liver weight to the body at 28 days after DMN induction. Administration of with a clinical dose decreased significantly the sAST level $(158.8{\pm}7.76\;IU/L)$ elevated by DMN in jection (p<0.01). A similar phenomenon was also observed at change of both Salt and Salt level in the GJT and/or DMN-treated animal (p<0.01, p<0.05, respectively). A remarkable increase of hydroxyproline was observed by treatment of DMN with comparing to the normal rat $(361.9{\pm}7.35\;vs.\;1278.1{\pm}52.9\;{\mu}g/g\;tissue,\;p<0.01)$. This was significantly reduced by a simultaneous treatment of GJT with DMN for 21 days (p<0.05), but not recovered completely to its normal value. In addition. GJT administration ameliorated conspicuously the DMN-induces histopathological changes of liver such as hemorrhage. Cell necrosis and fibrosis. Tak'en together, results described here demonstrated scientifically in first the medicinal efficacy of GJT by using in vivo animal model, indicating that GJT improves the DMN-induced hepatic injury through reducing an excessive accumulation of collagen and histopathological changes. The decreased collagen content may be a pivotal process for GJT to improve hepatic function in the DMN-induced liver fibrosis. The present study suggests that GJT may be useful for and applicable to the treatment of hepatic fibrosis in chronic liver disease.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.669-679
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• 2016

Architectural firms that would like to adopt the BIM are currently in an unfavorable position because of reduced orders, polarization of orders, and low price design. This study was conducted to evaluate plausible methods for supporting introduction of BIM into small sized firms. Before suggesting plans for support, we analyzed support projects and laws relating to support for small sized firms, after which we conducted a survey of small sized firms that support the project. The survey was completed by 242 architects and consisted of questions regarding the following aspects: current status and problems associated with BIM utilization, preference of certain policies for BIM introduction support, and reasonable level of support. After the survey, it was concluded that architectural firms are willing to use BIM and agree with the need for financial support for BIM program purchase and education, as well as to support BIM experts and fund low interest loans. In conclusion, it is proposed that support plans for small sized architectural firms in the areas of BIM introduction consulting, financial funding for the introductory process, provision of education and experts, order support, and promotions for accomplishment be provided.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.1
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• pp.88-96
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• 2020

It were found that the heavyweight waste glass can be used as a construction materials including concrete from previous experimental studies. In this study, in order to evaluate the structural behavior of RC members using heavyweight waste glass as fine aggregate, a flexural behavior test was performed. And then, its results were compared with those obtained from non-linear finite element model analysis. From the results, when the heavyweight waste glass as fine aggregate in RC member, the area of compressive crushing and the number of cracks increased, however, the mean of cracking spacing decreased. Also it had reduced the ductility at high loading stage. For this reason, the same analysis method about the RC member using natural sand as fine aggregate did not predict the initial stiffness, yield load and maximum load on the flexural behavior of the RC members using heavyweight waste glass as fine aggregate. On the other hand, when it is analytically implemented the reduction of neutral axis depth due to developed compression crushing, the results of non-linear finite element analysis could be predicted the experimental results, relatively well.