• Journal of Life Science
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• v.21 no.7
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• pp.1039-1045
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• 2011

The effects of duration and time-dependent, high-intensity exercise on hematological properties and inflammation-related parameters in rats were studied. 20, 60, and 120 min of high-intensive exercise were performed daily for 8 weeks. None of the complete blood count (CBC) factors were affected by the exercise, except for the leukocyte concentration which, in the 20 min group, showed an increase of 47% compared to the control, but this was decreased after 60 min by 30% compared to the control. As exercise was performed for 60 min or longer, serum concentrations of $Fe^{++}$, unsaturated iron biding capacity (UIBC), and total iron biding capacity (TIBC) were significantly elevated in comparison to the control, where 20 min of exercise did not show any change. Both levels of interleukin-6 (IL-6), a pro-inflammatory cytokine, and interleukin-10 (IL-10), an anti-inflammatory cytokine in the serum, were elevated in response to the high-intensity exercise, however the rate of IL-6 increase was higher than the rate of exercise intensity increase, thus the offset of inflammation might be suggested. The concentration of nitric oxide (NO) in the serum became high in response to the exercise. Overall, the current observation suggests that inflammation-like responses to high-intensity exercise might be due to high circulation of blood flow and high oxygen requirement, resulting in systemic damages. However, under the current high-intensity exercise conditions, more than 20 min of exercise might not be suggested for health care purposes.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.4
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• pp.55-61
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• 2010

This paper is concerned with an experimental research to random vibration control caused by external loads specially in bridges which tend to be structurally flexible. Experimenting on a reduced structure modelled on Seohae Grand Bridge, we inflicted a reduced form of El-centro wave on the model structure to a proper proportion. On the center of its middle span, we placed a shear type MR damper which was to control its vibration and also acquire its structural responses such as displacement and acceleration at the same site. The experiments concerning controlling vibration were performed according to a variety of theories including un-control, passive on/off control, and Lyapunov stability theory. Its control performance was evaluated in terms of the peak absolute displacements, the peak absolute accelerations and the total power required to control the bridge which differ from each different experiment method. Among all the methods applied in this paper, case of Lyapunov control method turned out to be the most effective to reduces of displacement and acceleration. Also, this method could to decrease consuming of external power for vibration control. Finally, it was noteworthy that Lyapunov control method was specially effective in the vibration control employing a semi-active damper such MR damper.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.5
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• pp.77-87
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• 2018

The Purpose of This study is amid competition, High-quality human resources in food service industry make a lot of efforts. Especially, Work and Life Balance(WLB) is a considerable factor when modern workers decide and maintain the workplace and also it could be supposed as one strategic method that corporations could attract and maintain talented people. This study built a exploratory model that there is causal relationship of WLB(work and life balance) to employee's organizational commitment. Additionally this study examine the Moderating Effect of perceived value of work between WLB(work and life balance) and organizational commitment. This study utilized total 217 responses from workers of food service industrial employees and as analysis methods, it used descriptive statistic analysis, correlation analysis, multiple regression analysis, and hierarchical analysis. Results of analysis are as follows. First this study found that the work-life balance could give significant effects to the organizational commitment. work-growth balance and work-leisure balance has positive significance effect with the organizational commitment but work-family balance was not statistically significant. Second, The significance of this study indicates that perceived value of work plays a role as moderating variable influencing the relationship between work and growth balance and employee organizational commitment. Lastly, this study suggested the implication of the result, the limitation and the direction of future study. The results of this study provide suggestion to the company.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.3
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• pp.193-202
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• 2004

Distraction osteogenesis(DO) is defined as a gradual mechanical process of mechanical stretching two vascularized bone surface apart with a critical rate and rhythm such that new bone forms within the expanding gap, reliably bridges the gap, and ultimately remodels to normal structure. DO has become a mainstay in bone tissue engineering and has significantly improved our armamentarium for reconstructive craniomaxillofacial procedures. But the molecular and biological mechanisms that regulate the formation of new bone during distraction osteogenesis are not completely understood. BMPs are potent osteoinductive agents. Our hypothesis was that BMPs, especially BMP-2 and BMP-4, might play an importent role in the signaling pathways that link the mechanical forces created by distraction to biological responses and in promting new bone formation. Using a rabbit's mandible, we investigated the expression of BMP-2, -4 at different time points during distraction osteogenesis. The purpose of this study is to research the pattern of expression of BMP-2, -4 in new bone formation during distraction osteogenesis of the rabbit mandible. The experimental group was applied gradual distraction (0.7mm a day by twice a day, 4.9mm in total, for 7 days) and the control group was carried out osteotomy alone. They were examined clinically, histologically, and by RT-PCR analysis. On 3 days after osteotomy, the high level of expression of BMP-2, -4 was detected. But, the expression of BMP-4 was decreased during latency period. As distraction was started, its expression was increased and maintained till postoperative 28days. In control group, the expression of BMP-4was remarkably decreased till postoperative 14 days. On the other hand, the expression of BMP-2 was no difference between experimental group and control group. The expression of BMP-4 was maintanined at high level during the entire experimental period in both group. These findings suggested that excellent bone formation during distraction osteogenesis is associated with enhanced expression of BMP-4 genes by mechanical tension stress.

• Journal of The Korean Association For Science Education
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• v.22 no.5
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• pp.1010-1029
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• 2002

The purpose of this research was to survey middle school students' preference for science and its causal factors, so as to analyze the causal relationships between them. Preference for science and its causal factors were defined theoretically, and a theoretical model was constructed to measure them and analyze the causal relationship by structural equation modeling. According to the theoretical model and a pilot test, a questionnaire was developed with three parts; the background information of a respondent, the preference for science, and the causal factors of preference. The questionnaire was administered to one class per grade of randomly selected 8 middle schools from 4 areas across the country, and 819 students' data were collected. Preference for science was defined as a state of mind. It revealed to what extent, and how, one likes science. It consisted of 3 categories - 'emotional response', 'behavioral volition', 'valuational comprehension', and each category was divided into two subcategories. Causal factors affecting the preference for science consisted of three categories - personal, educational and social factors, and each was divided into 2 or 3 subcategories. Middle school students' preference for science was middling as a total. Curiosity about contents of science and valuation of science were high, comparatively, but behavioral volition about science was especially low. Students' responses to the causal factors were relatively high in every educational factor and sociocultural valuation of social factors, but relatively low in socioeconomic rewards of social factors, and especially low in personal factors. The causal relationship about the preference for science was investigated by multiple regression analysis and path analysis, using the structural equation model. Multiple regression analysis about the preference for science and its causal factors revealed important factors. The important factors were personal ability, the personal traits, rewards in school science, and contents of school science in order of magnitude of standardized regression coefficient ${\beta}$. Stepwise regression analysis with each of the subcategories of the preference for science as dependent variables showed what factors were important in each subcategory. According to the result of structural equation modeling, personal factors affected 'emotional response' and 'behavioral volition' directly, and social factors affected 'valuational comprehension' directly. Educational factors affected all categories of the preference for science by influencing not only 'emotional response' and 'valuational comprehension' directly, but also 'behavioral volition' indirectly. The way to promote middle school students' preference for science was suggested, based on the analysis result.

• The Korea Journal of Herbology
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• v.27 no.5
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• pp.1-7
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• 2012

Objectives : This study was conducted to 9% compared with the previous experimental obesity-induced metabolic function in rats that it was a mixture of pear extract and herbal drugs(Lycii Fructus, Coicis Semen, Alimatis Rhizoma and Astragali Radix) on high fat diet-induce obesity rats. Methods : The animals were used in male rats. Control group fed high-fat diet only. Experimental groups were divided four, ExpI group was fed high-fat diet with a mixture pear extract and Lycii Fructus 9%, Exp II group was fed high-fat diet with a mixture pear extract and Coicis Semen 9%, Exp III group was fed high-fat diet with a mixture pear extract and Alimatis Rhizoma 9%, and Exp IV group was fed high-fat diet with a mixture pear extract and Astragali Radix 9% for 4 weeks. Results : The body weight gain increased in all groups, but attenuated gradually in the experimental groups compared to the control group. The food intakes were significantly lower in all Exp groups than the control group. The concentrations of serum total cholesterol (TC), LDL-cholesterol, and free fatty acid were significantly lower in Exp II than in the control group. Also the concentration of serum free fatty acid was significantly lower in the Exp IV group than in the control group. In inflammatory activities, the Exp II, IV group was significantly lower than the control group. Conclusion : The results indicated that Exp I group (administered a mixture of pear extract and Lycii Fructus) reduced fat accumulation, body weight and the highest elevated lipid metabolism, while the Exp II group (administered the mixture of pear extract and Coicis Semen) and Exp IV group (administered the mixture of pear extract and Astragali Radix) had the highest elevated immune activity.

• Journal of Korea Water Resources Association
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• v.30 no.2
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• pp.177-191
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• 1997

The influences of the space allocation of design rainfall and partition of the subbasin on the characteristics of urban storm runoff was investigated for the 6 drainage basins by applying SWMM model. It show the deviation of -54.68∼18.77% in the peak discharge when we applied the composed JUFF quantiles to the two zones which are divided by upper and lower region of the basin. Then it is compared with the value for the case of using uniform rainfall distribution all over the drainage. Therefore, it would be helpful to decrease the flood risk when we adopt the space distribution of the design rainfall. The effects of the partitioning the drainage on the computing result shows various responses because of the surface characteristics of the each basin such as slope, imperviousness ratio, buy we can get closer result to the measured value as we make the subbasin detailed. If we use the concept of the skewness and area ratio when we determine the width of subbasin, we can improve the computed result even with fewer number of subbasins. We expect reasonable results which close into the measured results in the range of relative error, 25%, when we divide the basin into more than 3 subbasins and the total urban drainage area is less than 10$\textrm{km}^2$.

• Korean Journal of Environment and Ecology
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• v.23 no.1
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• pp.78-89
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• 2009

As 'design for all' and 'adaptable design', universal design is highly demanded to be adopted in neighborhood forest trail. The research areas were Mt. Doeum in Pohang, Gyeongsangbuk Province and Mt. Anma in Chuncheon, Gangwon Province which were equipped based on 7 principles of universal design. The purpose of this research is providing baseline data for effective formulation of forest trail using universal design through visitors' evaluation on forest trail facilities by importance-performance analysis. Visitor's evaluation was achieved through questionnaire survey, and total 247 pieces of subjects were used for the analysis, 114 pieces from Mt. Doeum in Pohang and 113 pieces from Mt. Anma in Chuncheon. The residential areas of the respondents were mainly near each mountain - Mt. Doeum and Mt. Anma. According to the responses, nature study and education were the biggest reasons for the respondents' visits to Mt. Doeum, and so was the health to Mt. Anma, which are representative types of visiting behavior to nearby forest trails. The mean of importance was shown to be 3.87 while that of performance was 4.04, being a little higher than importance's, in importance-performance analysis of Mt. Doeum. This result suggests that the responders placed positive value on the forest trail applying universal design. It is necessary to improve the safety and convenience of guidance-safety handrail, make information sign easy to understand, and introduce an interpretive sign meeting the visiting purposes of visitors. Also, the management to make the road surface flat is in demand for the accessibility to forest trail. The mean of importance was 3.92 and that of performance was 3.99 in Mt. Anma, which suggests the necessity of improvement in safety of pavement material and boundary safety facilities.

• Korean Journal of Poultry Science
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• v.47 no.1
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• pp.49-59
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• 2020

The present study determined the effect of dietary cultivated microalgae (Parachlorella sp.) on the growth and immune responses of pre-starter broilers. A total of 320 one-day-old birds (Ross 308) were allocated to 4 treatments with 8 blocks in a randomized complete block design. The four experimental diets consisted of a corn-soybean meal-based control diet, and three diets contained 0.5%, 1.0%, and 1.5% microalgae powder at the expense of cornstarch in the control diet. After feeding the experimental diets for 7 days, the body weight and feed intake of all birds were measured, and 8 birds were randomly selected from each treatment. Peripheral blood mononuclear cells (PBMCs) and serum were harvested for immune profile assessment, including cytokines and cell migration receptors. No differences in growth performance were observed among the treatments. The birds that were fed diets containing graded levels of microalga showed a linear increase in the mRNA expression of cytokine genes in PBMCs, including that of IL2, IL1β, and IL18 (P<0.05). With respect to the chemokine receptor genes in PBMCs, mRNA expression of CCR2, CCR9, and ITGA4 changed quadratically (P<0.05), but that of CCR7 increased linearly (P<0.01). Cytokine protein secretion in blood, including that of IL-1β and IL-6, increased linearly (P<0.01) with an increase in the microalgal content. Overall, the present results show that the indigenous microalgae powder used in this study could stimulate immunity with no detrimental effects on the growth performance of pre-starter broiler chickens.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.5
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• pp.319-329
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• 2020

Among the bridges used in Korea, those that are more than 30 years old account for approximately 11% of the total bridges. Therefore, developing a seismic performance-evaluation method is necessary by considering the bridge age. Three composite steel-concrete box girder bridges with port, elastic-rubber, and lead-rubber bearings were selected, and a structural analysis model was developed using the OpenSEESs program. In this study, pier aging was reflected by the reduction in the area of the longitudinal and transverse rebars. Four conditions of 5%, 10%, 25%, and 50% in the degree of pier aging were used. As input earthquakes, 40 near-fault and far-field earthquakes were used, and the maximum displacement and maximum shear-force responses of the piers were obtained and compared. The result shows that as the aging degree increases, the pier strength decreases. Therefore, the pier displacement response increases. To analyze the effects of displacement response and shear resistance, displacement ratio D_ratio and shear-force ratio F_ratio were evaluated. The older the sample bridge is, the greater is the tendency of D_ratio to increase and the smaller is the tendency of F_ratio to decrease.