• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.3
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• pp.159-174
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• 2020

This study is an empirical study analyzing the effects of positive psychological capital on job burnout. In addition, positive psychological capital played a role in organizational citizenship behavior, and tried to verify the role of organizational citizenship behavior as a black box, or parameter, between job burnout. And then, the sub-factors of organizational citizenship behavior were divided into two: individual-oriented organizational citizenship behavior and organization-oriented organizational citizenship behavior. To this end, a questionnaire survey was conducted for members of small and medium-sized enterprises to compare and analyze the relationship between variables. Positive psychological capital is increasing interest in that it can reduce the job burnout of members and embrace the propensity of young generations represented by millennials because it can improve the effectiveness by developing positive mental states and strengths of the organization. There is a need for research as a keyword. As a result of this study, first, it was found that positive psychological capital of SME(small and medium-sized enterprises) members had a positive effect on organizational citizenship behavior. Second, positive psychological capital was found to have a significant negative effect on job burnout. Third, it was a verification of how positive psychological capital and organizational citizenship behavior affect job burnout. In the relationship between positive psychological capital and job burnout, organization-oriented organizational citizenship behavior was found to play a mediating role. However, it was found that individual-oriented organizational citizenship behaviors among the organizational citizenship behaviors are not valid. In this study, positive psychological capital and job burnout, which have been mainly studied in service workers' emotional workers(crew, nurses, counselors, etc.), nursery teachers, and social workers, were applied to SME members by using the parameters of organizational citizenship behavior. You can put that implication on things. The positive psychological capital and organizational citizenship behavior can be further enhanced through SME members' love for the company, improvement of consideration among employees and resulting organizational commitment and work performance. It could also provide momentum for sustainable management for small and medium-sized enterprises that are relatively short of capital and resources.

• The Korean Journal of Pesticide Science
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• v.2 no.1
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• pp.85-90
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• 1998

A series of experiments were carried out to determine the effect of seed dressing application of chemicals on the early occurring rice insect pests. The number of small brown planthopper adults per 3hills in seed-dressing plot of Imidacloprid WS (Im WS) was 1.6 and its control efficacy was over 90%, compared with that of untreated plot. Rice water weevil was observed in the density of 8.8 larvae per 5 hills seed-dressed Im WS plots(showing 95.5% of control efficacy). Control efficacy of Im WS and Im GR against adult weevils lasted for 26 days after treatment and was higher than that of Carbofuran GR. Rates of injured stems by rice stem maggot and injured leaves by rice leaf miner were 3% and 3.7% in Im WS treatment plot respectively. Seed germination rate after seed dressing with recommended dosage (3 g/seed kg) of Im WS was 71 % on the 1st day and increased on 5th day up to that of untreated seed. The residual amount of Im in seed dressing plot was 0.11 ppm in rice roots and 0.05 ppm in leaves on the 40th day after treatment. Residual effect of Im WSI sustained for 50 days with over 95% insecticidal effect for the rice water weevil and over 90% for the brown planthopper. Quantity of the chemical applied in the field was calculated as 0.084 kg a.i./ha in seed dressing and 0.3 kg a.i./ha in seed box treatment, respectively It took 1 hour to treat insecticide by seed dressing, 2.5 hours by seed box applying, and 3.6 hours by water surface releasing per 990 $m^2$.

• Journal of Life Science
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• v.23 no.8
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• pp.989-997
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• 2013

In this study, based on the antioxidative effects in organic solvent fractions obtained from the main methanolic extract of L. japonica, the protective cellular effects and gene expression patterns of ethyl acetate fractions on $H_2O_2$-induced Raw 264.7 cell death ($IC_{50}$) were analyzed. The antioxidant activity of the fractions measured using DPPH free radical scavenging activity increased in a dose-dependent manner, and the $ED_{50}$ exhibited the highest $39.56{\mu}g/ml$ in the ethyl acetate fraction. In addition, the ethyl acetate fractions' cell viability on $H_2O_2$-induced Raw 264.7 cell damage increased in a concentration-dependent manner, showed a visible cell survival rate of 82.49% at a concentration of $100{\mu}g/ml$. The gene expression patterns related to the ethyl acetate fractions' cytoprotective effect in $H_2O_2$-induced Raw 264.7 cell damage presented similar patterns to those of BHA. In comparative analysis for antioxidant activity-related genes affected by ethyl acetate fractions and BHA in $H_2O_2$-induced Raw 264.7 cells, both ethyl acetate fractions and BHA showed very similar gene expression patterns, but the gene expression level of the heme oxygenase 1 (Hmox1) gene making antioxidant enzymes in cells was four times higher in ethyl acetate fractions than BHA. In inflammation-related genes in $H_2O_2$induced Raw 264.7 cells, the T-box transcription factor (Tbx21) gene was expressed about two times more frequently in the ethyl acetate fraction treatment group, while it was expressed half as frequently in the BHA treatment group.

• Korean Journal of Ecology and Environment
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• v.48 no.4
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• pp.238-252
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• 2015

The effect of weir construction (2009~2011) was investigated on algal bloom dynamics and surrounding conditions in the Youngsan River by analyzing the long-term (2001~2014) data provided by the Water Information System, Ministry of Environment. The data include chlorophyll a and water properties such as total suspended solids (TSS), ammonium ($NH_4{^+}$), nitrate ($NO_3{^-}$), orthophosphate ($PO{_4}^{3-}$), total nitrogen (TN), total phosphorus (TP) and DIN/DIP molar ratio collected from 12 stations along the channel of the river. Temporal variations were examined using data collected monthly from 2001~2014 and Box-Whisker plot was used to examine the difference in algal bloom dynamics between before (2006~2008) and after (2012~2014) the weir construction. Pearson's correlation analysis was also used to analyze the correlation of parameters. The results showed that TSS affecting water turbidity increased during the construction but decreased especially at the stations located in the upper and middle regions of the river after the construction. Ammonium concentrations increased whereas the concentrations of other nutrients decreased after the construction inducing an increase in N:P molar ratio. Chlorophyll a decreased suddenly during the construction but increased clearly after the construction at the stations where TSS decreased. This indicates that algal blooms can develop in the Youngsan River due to a decrease in turbidity that increases light penetration in water column although the concentrations of nutrients such as orthophosphate were reduced after the weir construction.

• Food Science of Animal Resources
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• v.26 no.1
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• pp.37-42
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• 2006

The current study was conducted to investigate the effect of types of crate and season on transport condition and mortality, and ultimately to identify the best practice for reducing economic lose. Total loading weight stocking density, transport and lairage times and mortality were surveyed from the management data sheet of two companies for each first week of January, April, August and October, An average loading weight, length of transport and lairage times and mortality were 3.9 ton, 96 min, 478 min and 0.6%, respectively. Mortality after lairage was not significant between two types of crate. In addition, container type crate showed higher loading weight and stocking density than box type one. Spring and winter had significantly higher mortality with 0.7 and 0.8%, respectively, then summer and fell of 0.5%. An interaction between crate type and season on mortality showed that mortality for box type on was higher in spring and winter with 0.8 and 0.7%, respectively, compared to summer and fall of 0,3 and 0.4% respectively. In the case of container type crate, spring, fall and winter had greatly different death into with 0.7, 0.5 and 0.8%, respectively, while there was no difference between spring and summer, and between summer and winter, Mortality after transportation was similar between both crate type, with higher rate for spring and winder than other seasons. The result was likely related to death of exposure due to extended waiting time without heating facility.

• Restorative Dentistry and Endodontics
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• v.36 no.5
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• pp.425-430
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• 2011

Objectives: This in vitro study investigated whether short-term application of calcium hydroxide in the root canal system for 1 and 4 wk affects the fracture strength of human permanent teeth. Materials and Methods: Thirty two mature human single rooted mandibular premolars in similar size and dentin thickness without decay or restorations were hand and rotary instrumented and 16 teeth vertically packed with calcium hydroxide paste and sealed coronally with caviton to imitate the endodontic procedure and the other 16 teeth was left empty as a control group. The apicies of all the samples were sealed with resin, submerged in normal saline and put in a storage box at $37^{\circ}C$ to mimic the oral environment. After 1 and 4 wk, 8 samples out of 16 samples from each group were removed from the storage box and fracture strength test was performed. The maximum load required to fracture the samples was recorded and data were analysed statistically by the two way ANOVA test at 5% significance level. Results: The mean fracture strengths of two groups after 1 wk and 4 wk were similar. The intracanal placement of calcium hydroxide weakened the fracture strength of teeth by 8.2% after 4 wk: an average of 39.23 MPa for no treatment group and 36.01 MPa for CH group. However there was no statistically significant difference between experimental groups and between time intervals. Conclusions: These results suggest that short term calcium hydroxide application is available during endodontic treatment.

• Journal of Life Science
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• v.21 no.7
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• pp.953-960
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• 2011

Necrosis is characterized by the cell membrane rupture and release of the cellular contents, including high-mobility group box 1 protein (HMGB1), into the extracellular microenvironment. HMGB1 acts as a transcriptional regulator in nuclei, but exerts a pro-inflammatory and tumor-promoting cytokine activity when released into the extracellular space. Its overexpression is associated with tumor progression and chemoresistance. Thus, HMGB1 acts as a clinically important molecule in tumor biology. In this study, we examined whether HMGB1 affects cell death induced by anti-cancer drugs. Here we show that HMGB1 prevented cisplatin (alkylating agent)-induced apoptosis and switched the cell fate to necrosis in MCF-7, MDA-MB231, and MDA-MB361 cells. Similar apoptosis-to-necrosis switch effects of HMGB1 were observed in cells treated with 4-HC, another alkylating agent. In contrast, HMGB1 did not exert any significant effects on docetaxel (DOC)-induced apoptosis in MCF-7 cells. We also show that cisplatin-induced apoptosis was switched to necrosis in MCF-7 multicellular tumor spheroids (MTS) that were cultured for 8 days and had necrotic cores, but DOC-induced apoptosis was prevented without the apoptosis-to-necrosis switch. Finally, the levels of RAGE, a receptor of HMGB1, were increased with extended culture of MTS. These findings demonstrate that HMGB1 switches alkylating agent-induced apoptosis to necrosis, suggesting that the strategy to prevent necrosis occurring as an undesirable action of alkylating agent-based chemotherapy should be delineated to improve the efficacy of chemotherapy for cancer.

• Journal of Korean Home Economics Education Association
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• v.16 no.1
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• pp.63-77
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• 2004

The purpose of this study was to construct an issue-centered discussion instructional model for Home Economics and to determine its effect on middle school students' critical thinking. The research questions were posed as below. 1) The object and content of home economics in the 7th national middle school curricula are analyzed to sort out possible issues. 2) An issue-centered discussion instructional model is constructed to be applicable to middle school home economics class. and a lesson plan is prepared. 3) The effect of the issue-centered discussion instructional model developed in this study on student critical thinking faculty is examined. The findings of this study were as follows : First. seven criteria were selected to determine what types of issues were applicable to home economics lesson. Based on the selected criteria. 41 themes of issues were extracted from the 7th middle school textbooks. and their content validity was verified. Second, an issue-centered discussion instructional model was designed to deal with four themes in eight sessions in the procedure of problem raising, confirming, term defining. tentative alternative selecting, data gathering. discussing/critical approaching. and selecting/concluding. Third, two different third-year classes of K middle school in the city of Busan that consisted of 75 students were respectively selected as an experimental group and a control group, and the experiment was conducted in eight sessions for five weeks to see whether the teaching plan brought any changes to the critical mind of the students. The experimental group exposed to the issue-centered discussion lesson made a significant progress in critical thinking faculty(P＜.05). In particular. that instruction gave a favorable impact on demonstration evaluating(P＜.05). one of the critical thinking subfactors. When the students were asked to assess the issue-centered discussion lesson. most of them viewed it favorably. In the future, more research efforts should be dedicated to enhancing the practical applicability of issue-centered discussion instruction in home economics education. developing good evaluation tools about critical thinking faculty and finding out how discussion instruction could be conducted more efficiently.

• Radiation Oncology Journal
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• v.22 no.2
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• pp.130-137
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• 2004

Purpose : In radiotherapy for cervix cancer, both 3-dimensioal radiotherapy (3D-CRT) and intensity-modulated radiation therapy (IMRT) could reduce the dose to the small bowel (SB), while the small bowel displacement system (SBDS) could reduce the SB volume in the pelvic cavity. To evaluate the effect of the SBDS on the dose to the SB in 3D-CRT and IMRT plans, 3D-CRT and IMRT plans, with or without SBDS, were compared. Materials and Methods : Ten consecutive uterine cervix cancer patients, receiving curative radiotherapy, were accrued. Ten pairs of computerized tomography (CT) scans were obtained in the prone position, with or without SBDS, which consisted of a Styrofoam compression device and an individualized custom-made abdominal immobilization device. Both 3D-CRT, using the 4-field box technique, and IMRT plans, with 7 portals of 15 MV X-ray, were generated for each CT image, and proscribed 50 Gy (25 fractions) to the isocenter. For the SB, the volume change due to the SBDS and the DVHs of the four different plans were analyzed using palled t-tests. Results : The SBDS significantly reduced the mean SB volume from 522 to 262 cm$^{3}$ (49.8$\%$ reduction). The SB volumes that received a dose of 10$\~$50 Gy were significantly reduced in 3D-CRT (65$\~$80$\%$ reduction) and IMRT plans (54$\~$67$\%$ reduction) using the SBDS. When the SB volumes that received 20$\~$50 Gy were compared between the 3D-CRT and IMRT plans, those of the IMRT without the SBDS were significantly less, by 6$\~$7$\%$, than those for the 3D-CRT without the SBDS, but the volume difference was less than 1$\%$ when using the SBDS. Conclusion : The SBDS reduced the radiation dose to the SB in both the 3D-CRT and IMRT plans, so could reduce the radiation injury of the SB.

• Korean Journal of Agricultural Science
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• v.7 no.2
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• pp.131-144
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• 1980

The Linear Regression Model to extend the monthly runoff data in the short-recorded river was proposed by the author in 1979. Here in this study generalization precedure is made to apply that model to any given river basin and to any given station. Lengthier monthly runoff data generated by this generalized model would be useful for water resources assessment and waterworks planning. The results are as follows. 1. This Linear Regression Model which is a transformed water-balance equation attempts to represent the physical properties of the parameters and the time and space varient system in catchment response lumpedly, qualitatively and deductively through the regression coefficients as component grey box, whereas deterministic model deals the foregoings distributedly, quantitatively and inductively through all the integrated processes in the catchment response. This Linear Regression Model would be termed "Statistically deterministic model". 2. Linear regression equations are obtained at four hydrostation in Geum-river basin. Significance test of equations is carried out according to the statistical criterion and shows "Highly" It is recognized th at the regression coefficients of each parameter vary regularly with catchment area increase. Those are: The larger the catchment area, the bigger the loss of precipitation due to interception and detention storage in crease. The larger the catchment area, the bigger the release of baseflow due to catchment slope decrease and storage capacity increase. The larger the catchment area, the bigger the loss of evapotranspiration due to more naked coverage and soil properties. These facts coincide well with hydrological commonsenses. 3. Generalized diagram of regression coefficients is made to follow those commonsenses. By this diagram, Linear Regression Model would be set up for a given river basin and for a given station (Fig.10).