• Economic Analysis
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• v.26 no.1
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• pp.1-33
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• 2020

Recent discussions about a minimum wage increase (MWI) and its influence on the economy have mainly focused on the quantitative aspects, such as labor costs and employment. However, concerning the qualitative aspects, an MWI could have positive effects by enhancing firm productivity and crowding out marginal firms from the market. These positive effects of an MWI can offset, to some extent, its potential negative effects - increasing labor costs and decreasing employment, among others. In this regard we empirically examine the impact of an MWI on firm productivity (total factor productivity). Using firm level panel data from the manufacturing industry in Korea, we calculate the influence rates of a minimum wage by sector and by firm size (number of workers), and analyze its effects on firm productivity. In particular, the production functions of the firms are estimated by taking into account endogeneity among the input factors, in order to resolve the drawbacks of existing studies - underestimating the capital factor coefficient and overestimating the labor factor coefficient. This study finds that the influences of an MWI on wages, employment, and productivity are substantially different across sectors and firm sizes. While an MWI has shown to have positive influences on productivity growth in the manufacturing industry as a whole, each sector demonstrates a different direction of effect, and the degree of productivity change also varies by sector. The impacts of an MWI on firm productivity are generally estimated to be more negative for smaller firms, but in some sectors the effects are found to be positive. In addition, the wage increases resulting from an MWI seem to cause a productivity enhancement across all sectors in the manufacturing industry. The policy implications of this study are as follows. Considering the empirical findings that an MWI causes an increase in productivity in many sectors of the manufacturing industry, it would be desirable to take into consideration not only the negative side effects but also the positive effects of an MWI when designing any future minimum wage policy. Moreover, in spite of there being a uniform minimum wage, this study finds that the diverse influence rates of a minimum wage across firms have different impacts on wages, employment, and productivity across sectors or firm size. This finding could be conducive to discussions about differentiation among minimum wage schemes by sector or firm size.

• Journal of the Korea Convergence Society
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• v.13 no.5
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• pp.279-286
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• 2022

The purpose of this study is to examine the mediating effect of physical activity in the relationship between generalized anxiety disorder and overdependence on smartphones in adolescents. To find a way for solving the problems caused by the over-use of smartphones during adolescence, we tried to find the importance of a health promotion program through physical activities. For the purpose of the study, the 2020 Youth Health Behavior Survey data conducted by the Ministry of Education, the Ministry of Health and Welfare, and the Korea Centers for Disease Control and Prevention were used as analysis data for this study. As a result of the study, firstly, generalized anxiety disorder has a negative (-) relationship with physical activity, and physical activity also has a negative (-) relationship with overdependence on smartphones. Secondly, as a result of analyzing the mediating effect of physical activity in the relationship between generalized anxiety disorder and smartphone overdependence experience, the physical activity was found to be a significant factor. Thirdly, it was confirmed that the physical activity has a partial mediating effect in the relationship between generalized anxiety disorder and smartphone overdependence experience. Increasing physical activity through team sports rather than individual sports may help reduce smartphone use.

• Journal of Life Science
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• v.28 no.2
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• pp.187-194
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• 2018

Eritadenine (EA), derived from Lentinus edodes (LE), reduced low-density lipoprotein (LDL), triglyceride (TG), and phospholipids in bloods, and fatty acid depositions in animals and humans. Previously, we reported that EA inhibited angiotensin-converting enzyme (ACE) activity in vitro. Now, we report that EA reduced blood pressures in spontaneous hypertension rats (SHR). EA-containing LE mycelial culture enzyme extract (EA-LEMSCEE) was prepared from LE mycelial solid cultures and the hot-water extract of LE fruit bodies. Both EA and EA-LEMSCEE inhibited ACE activity in immortalized human umbilical endothelial cells (EA.hy926). EA-LEMSCEE treatments (7.5 mg/kg, 22.5 mg/kg) significantly reduced systolic and diastolic blood pressure in SHR. At five weeks of treatment, EA-LEMSCEE treatment significantly reduced systolic and diastolic blood pressure, similar to the positive control (captopril, CP; 4 mg/kg) treatment. In addition, the LEMSCEE without EA decreased systolic and diastolic blood pressures compared to the control, but not significant. EA-LEMSCEE decreased renin and ACE activities, and angiotensin II (Ang II) contents in SHR compared to the control. After five weeks of treatment, the effect of EA-LEMCEE was similar to that of CP. These results indicate that EA and EA-LEMSCEE reduce blood pressure by inhibiting the renin and ACE activity of SHR. Furthermore, these results imply that EA or EA-LEMSCEE could be used as an antihypertension agent in humans.

• 한국유가공학회:학술대회논문집
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• 2005.06a
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• pp.37-61
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• 2005

Microcapsules consisting of natural, biodegradable polymers for controlled and/or sustained core release applications are needed. Physicochemical properties of whey proteins suggest that they may be suitable wall materials in developing such microcapsules. The objectives of the research were to develop water-insoluble, whey protein-based microcapsules containing a model water-soluble drug using a chemical cross-linking agent, glutaraldehyde, and to investigate core release from these capsules at simulated physiological conditions. A model water soluble drug, theophylline, was suspended in whey protein isolate (WPI) solution. The suspension was dispersed in a mixture of dichloromethane and hexane containing 1% biomedical polyurethane. Protein matrices were cross-linked with 7.5-30 ml of glutaraldehyde-saturated toluene (GAST) for 1-3 hr. Microcapsules were harvested, washed, dried and analyzed for core retention, microstructure, and core release in enzyme-free simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) at 37$^{\circ}C$, A method consisting of double emulsification and heat gelation was also developed to prepare water-insoluble, whey protein-based microcapsules containing anhydrous milkfat (AMF) as a model apolar core. AMF was emulsified into WPI solution (15-30%, pH 4.5-7.2) at a proportion of 25-50% (w/w, on dry basis). The oil-in-water emulsion was then added and dispersed into corn oil (50 $^{\circ}C$)to form an O/W/O double emulsion and then heated at 85$^{\circ}C$ for 20 min for gelation of whey protein wall matrix. Effects of emulsion composition and pH on core retention, microstructure, and water-solubility of microcapsules were determined. Overall results suggest that whey proteins can be used in developing microcapsules for controlled and sustained core release applications.

• Journal of Engineering Education Research
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• v.16 no.2
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• pp.78-85
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• 2013

An 'Introduction to Creative Engineering Design' course at College of Engineering at Chungnam National University is required for all freshmen. The objective of this course is to educate the freshmen with basic engineering design concepts and experiences in creative problem-solving approaches. It provides the students learning opportunities in solving engineering design problems through team efforts and creative approaches. Thus, this course emphasizes creative ideas and thinking, engineering design experiences to students over the course. This study presents the syllabus, the examples of PBL (problem based learning)-related activities as a team, and the results of the course evaluation and outcomes. Based on the results of this study, we can conclude that overall this course using PBL method had significant positive effects on the course outcomes and the creativity of the engineering freshmen in the department of environmental engineering at Chungnam National University. However, there are still efforts to be needed to improve the PBL-related activities in the course, including students' workload, financial supports, and team work.

• Journal of the Korean Geotechnical Society
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• v.25 no.6
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• pp.31-45
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• 2009

The aim of this study is to evaluate the applicability of Granulated Blast Furnace Slag to the development of the Powdered Ready-mixed Shotcrete. First of all, after accomplishing SEM analysis and Leaching Test, the laboratory and field experiments for evaluating the utility of Granulated Blast Furnace Slag were performed. As a result of SEM and Leaching test, the environmental stability was confirmed. That is, non-detection of harmful lists and dense shotcrete structure result from mixing Granulated Blast Furnace Slag. As a result of lab. and field test, Blast Furnace Slag is superior to Plain Batch in improving strength and durability. And it will be able to improve to some extent the problem caused by the delayed reaction of existing Granulated Blast Furnace Slag with alkali activated material. Also the proper amount of Granulated Blast Furnace Slag is estimated to be under 30%. Finally, it is possible that Granulated Blast Furnace Slag can apply to economical recycling and development of the Ready-mixed Shotcrete for its price is only about 5% of Silica-finne's price.

• Cartoon and Animation Studies
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• s.47
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• pp.31-52
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• 2017

NCS education was created to realize a society in which skills and abilities are respected, such as transcending specifications, establishing recruitment systems, and developing and disseminating national incompetence standards. At the university level, special lectures and job training are being strengthened to raise industrial experts. Especially, in the field of animation, new technologies are rapidly emerging and demanding convergent talents with various fields. In order to meet these social demands, there is a limit to the existing one-class teaching method. In order to solve this problem, it is necessary to participate in a variety of specialized teachers. In other words, rather than solving problems of students' job training and job creation, It is aimed to solve jointly, Team teaching was suggested as a method for this. The expected effects that can be obtained through this are as follows. First, the field of animation is becoming more diverse and complex. The ability to use NCS job-related skills pools can be matched with professors from other departments to enable a wider range of professional instruction. Second, it is possible to use partial professorships in other departments by actively utilizing professors in the university. This leads to the strengthening of the capacity of teachers in universities. Third, it is possible to build a broader and more integrated educational system through cooperative teaching of professors in other departments. Finally, the advantages of special lectures and mentor support of college professors' pools are broader than those of field specialists. A variety of guidance for students can be made with responsible professors. In other words, time and space constraints can be avoided because the mentor is easily met and guided by the university.

• Journal of the Korea Convergence Society
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• v.11 no.6
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• pp.227-235
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• 2020

This study expanded the superiority of random leader selection procedure on group decision-making task to actual group performance task, and examined the interaction effects of leader selection procedure(LSP) and collective efficacy(CE) on group performance. 2(LSP: formal/random)×2(CE: low/high) between subject design was used. The result revealed the significant main effect of LSP, which showed that groups with random leader performed better than those with formally selected leader. Further, significant interaction effect of LSP and CE revealed that when group's CE was high, group with random leader performed better than group with formally selected leader, and the difference between two groups was not significant when group's CE was low. These results suggested that LSP should not impair shared social identity of the group in order to maintain the positive effect of CE on group performance. The necessity for expanding these results to work team was discussed.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.4
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• pp.219-228
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• 2022

Purpose : The purpose of this study was to suggest a more effective method by comparing the effects of changes in pain intensity, muscle strength, and athletic performance after applying a 6-week eccentric training program (ET-MWM) or concentric training program (CT-MWM) with MWM for high school baseball players with shoulder internal impingement (SII). Methods : A total of 75 participants were randomly assigned to each group and divided into two groups, "ET-MWM group (n=35)" and "CT-MWM group (n=32)" according to the intervention method. Pain intensity, muscle strength (external rotation, internal rotation), and athletic performance were first measured before the intervention, and after the intervention 3 times a week for a total of 6 weeks, both groups were re-measured in the same way. Visual analog scale (VAS) was used for pain intensity, biodex dynamometer for muscle strength (60 °/sec.), and Kerlan-Jobe orthopedic clinic shoulder & elbow score (K-KJOC) for athletic performance. Results : As a result of analyzing the homogeneity of the pre-intervention characteristics and initial measurement variables of the study subjects, there was no significant difference between the two groups in all variable values. Pain intensity (VAS) was significantly reduced in the ET-MWM group than in the CT-MWM group (p<.05). In addition, the maximum muscle strength of external rotation & internal rotation of the shoulder (60 °/sec.) and athletic performance (K-KJOC) were significantly increased in the ET-MWM group than in the CT-MWM group (p<.05). Conclusion : Compared with the CT-MWM training program, the ET-MWM training program reduced shoulder joint pain and further increased the muscle strength required for throwing motion in high school baseball players. As the result showed better athletic performance improvement, the ET-MWM training program can be clinically recommended as a more effective intervention.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.1
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• pp.87-98
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• 2023

Purpose : This study was to verify the effectiveness of eccentric training and to make clinical recommendations on detailed application methods by comparing the effects of changes in acromiohumeral distance (AHD), pain intensity, muscle strength, and functional performance after applying a 12-week eccentric training program (ET group) or concentric training program (CT group) for patients with partial rotator cuff (supraspinatus) tears with moderate to severe shoulder pain. Methods : A total of 29 subjects were assigned to either the "ET group (n=15)" or the "CT group (n=14)" through simple randomization and were measured in the same way at baseline before intervention, 4 weeks and 12 weeks after intervention. All subjects received a physical therapy program 12 sessions 3 times a week for the first 4 weeks, and physical therapy program, 12 sessions a week, from 4 weeks to 12 weeks, for a total 20 sessions. Ultrasound machine was used for AHD, visual analog scale (VAS) was used for pain intensity, electronic hand held dynamometer was used for muscle strength, Korean Constant shoulder score (K-CSS) used for functional performance. Results : AHD, pain intensity, and muscle strength did not show significant differences at 4 weeks, but improved numerically, and showed significant differences at 12 weeks (p<.05), showing superior results in the eccentric training group compared to the concentric training group. Functional performance showed significant changes at both 4 and 12 weeks (p<.05), and excellent results were also found in the eccentric training group. Conclusion : In patients with partial rotator cuff tears with moderate to severe shoulder pain, an eccentric training program increased acromiohumeral distance (AHD), reduced pain, and increased muscle strength. Therefore, it can be clinically presented as an intervention method that can quickly and effectively improve functional performance, which is the ultimate goal of physical therapy.