• Journal of The Korean Society of Grassland and Forage Science
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• v.8 no.2
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• pp.110-116
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• 1988

The response of forage yield was studied with various growth indices to develop yield model and to determine optimum cutting time in three cultivars of orchardgrass. 1. Number of tiller per plant was the highest at 3rd cutting stage. But, it was decreased rapidly at 4th cutting stage. Leaf Area Index (LAI) was the highest at 3rd cutting stage. LAI was increased slowly during 15 days to 20 days after cutting and thereafter increased rapidly. 2. In dry matter yield over cutting stages, 1st cutting and 3rd cutting stages were higher yield than others. Change of dry matter yield was similar to that of LAI in all cutting stages. 3. Leaf Elongation Rate (LER) and Specific Leaf Weight (SLW) were reached to maximum at 20 to 25 days and 25 to 30 days after cutting, respectively. 4. Dry matte yield was highly correlated with LAI (r-0.905)and with CGR (r-0.962) over three cultivars. Also, LAI was significantly with LER. The best-fit yield model was obtained in multiple regression equation which included both dependent variables of LAI and CGR. 5. Optimum cutting times which were determined by the relationships between D.M. yield and LAI, and between D.M. yield and CGR, were ranged from 32 days to 36 days depend on each cutting stages.

• Microbiology and Biotechnology Letters
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• v.31 no.1
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• pp.83-89
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• 2003

2,4-Dichlorophenoxyacetic acid (2,4-D) as a widely used herbicide has caused serious environmental problems because of its difficult decomposition in nature. We isolated the strain capable of metabolizing 2,4-D as sole carbon and energy source by an enrichment culture technique from the 2,4-D contaminated soil collected at orchard in Gwangju, Korea. This strain was identified tentatively as Aeromonas sp. NOH2. With this strain, we established the response surface methodology (Box-Behnken Design) to optimize the principle parameters for maximizing biodegradation of 2,4-D such as culture pH, temperature, and nutrient concentration in liquid batch culture. The ranges of parameters were obtained from preliminary works done at our laboratory and chosen as 5.5, 6.5, and 7.5 for pH, 25, 30, and $35^{\circ}C$ for temperature, and 5, 20, and 35 g/1 nutrient concentration. Initial concentration of 2,4-D was 500 ppm and nutrient source was tryptic soy broth. The experimental data were significantly fitted to a second order polynomial equation using multiple regression. The most important parameter influencing 2,4-D degradation and biomass production was nutrient concentration. For 2,4-D degradation, the optimum values of pH and temperature, and nutrient concentration were obtained at pH (6.5), temperature (31.8 to $32.1^{\circ}C$), and nutrient concentration (29.6 to 30.1.0 g/1).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.3685-3695
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• 2014

This study was performed to determine the suicide ideation and its association with hopelessness, psychosocial stress and depression among some middle school students. The survey was administered to 975 middle school students in Gyeongin area during the period, May $1^{st}$ to June $30^{th}$, 2013. Structured self-administered questionnaires were delivered and collected without the respondents' personal information. As a result, concerning the correlation of depression with various factors, the level of suicide ideation was positively correlated with hopelessness, psychosocial stress and depression. Multiple linear regression analysis showed that the factors influencing the suicide ideation included sex distinction, experience of alcohol drinking, hobbies and leisure life, subjective health status, grade, school violence experience, hopelessness, psychosocial stress and depression. An analysis of the covariance structure, hopelessness (BHOP) was more influential on the suicide ideation than psychosocial stress (PWI) and depression (CES-D). The study found that higher hopelessness, severe distress and higher depression tends to increase the suicide ideation.

• Journal of Distribution Science
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• v.16 no.6
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• pp.55-63
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• 2018

Purpose - Our Research is a study on the competition structure between retailers in traditional markets. Specifically, this study examined the effects of SSM, commodity supply store, Hanaro mart, food mart and other mart in traditional markets on retail stores of small businesses. The purpose of this study is to provide a solution to the market encroachment of large retailers in traditional markets. Research design, data, and methodology - This study is based on the data of 'Market Survey of Traditional Market·Shopping Mall and Store Management in 2016' and 'Current status of SSM(Super SuperMarket), commodity supply store, Hanaro mart, food mart and other mart in the traditional market in 2017' conducted by Small Enterprise and Market Service. In this study, a multiple regression equation was constructed using the number of SSM, commodity supply store, Hanaro mart, food mart and other mart as an independent variable and sales, number of customers as a dependent variable for analysis. Results - The increase of SSM and commodity supply stores in the traditional market affects the sales decrease of the surrounding small merchants in the traditional market. This means that the SSM and commodity supply stores can lead to the decline of the traditional market. However, it has been found that the penetration of these companies in traditional markets does not affect the number of visitors. Second, Hanaro mart's entry into the traditional market has a negative impact on the sales and visitor numbers of the surrounding small-scale merchants. The increase in the number of food mart has a significant effect on the sales and the number of visitors to the small stores. The results of this study indicate that the food mart can contribute to the revitalization of traditional markets. Lastly, other mart with more than medium size were found to affect the sales of small stores, the number of visitors. Conclusions - We examines the competitive structure among retailers in traditional markets. The penetration of large retailers in traditional markets has a negative impact on traditional markets, particularly Hanaro mart has a greater impact than SSM. We provide practical and theoretical implications for the retail competition structure in traditional markets.

• Journal of the Korean Chemical Society
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• v.42 no.6
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• pp.646-651
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• 1998

The molecular structure of sulfur compounds and the retention relationship are studied by gas chromatography. Analyzed sulfur compounds are, hydrogen sulfide, sulfur dioxide, carbon disulfide, ethyl mercaptan, dimethyl sulfide, iso-propyl mercaptan, normal propyl mercaptan, ethyl methyl sulfide, tert-butyl mercaptan, tetrahydrothiophene, thiophene, and 2-chlorothiophene. Multiple linear regression explains the retention relationship of molecular descriptors. In GC the temperature program is 30$^{\circ}C$ held for 10.5 min, and then increased to 150$^{\circ}C$ at a rate 15$^{\circ}C$/min. Predicted equation for relative retention time (RRT) using SAS program is as follows; $RRT=0.121bp+14.39dp-8.94dp^2+0.0741sqmw-35.78\; (N=8,\; R^2=0.989, \;Variance=0.175,\;F=66.21)$. RRTs are function of boiling point, the square root of molecular weight, molecular dipole moment, and boiling point effects mostly on RRT. The RRT is maximized at the molecular dipole moment of 0.805D, when using nonpolar columns. The planar and highly symmetric compounds are eluted slowly. The square, of correlation coefficient $(R^2)$ using SAS program, is 0.989, and the variance is 0.175 in training sets. For three sulfur compounds, the variance between observed RRTs and predicted RRTs is 0.432 in testing sets.

• Journal of Digital Convergence
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• v.15 no.10
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• pp.349-356
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• 2017

This study is executed to investigate convergent factors to job burnout(MBI-GS: Maslach Bunout Inventory-General Survey) among hospital administrative staff. The survey was administered to 201 staff from 9 general hospitals located in J area from Jul. 3rd, 2017 to Jul. 29th, 2017. The structured self-administered questionaries were used. The hierarchical multiple regression analysis shows the following results. The MBI-GS of respondents turned out to be significantly higher in following groups: a group in which Organizational Commitment Questionnaire(OCQ) is lower, a group in which Type A Behavior Pattern(TABP) is higher, a group in which depression(CES-D: Center for Epidemiologic Studies Depression scale) are higher. The results show explanatory power of 52.1%. The results of the study indicate that the efforts, to increase OCQ, and to decrease TABP and CES-D, are required to improve the MBI-GS among hospital administrative staff. The results are expected to be useful for the program and human resource management to related to the MBI-GS among HAS. In the following study, the analysis of structural equation modeling about additional factors of the MBI-GS among hospital administrative staff will be needed.

• Journal of Digital Convergence
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• v.16 no.6
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• pp.251-258
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• 2018

We study convergent factors to depression(CES-D: Center for Epidemiologic Studies Depression scale) among administrative staff in general hospital. The questionnaire was used using an unregistered self-administered questionnaire for 201 staff from 9 general hospitals located in J area from Jul. 3rd, 2017 to Jul. 29th, 2017. The hierarchical multiple regression analysis shows the following results. The depression of respondents turned out to be significantly higher in following groups: a group in which Rosenberg Self-Esteem Scale(RES) is lower, a group in which Multidimensional Fatigue Scale(MFS) is higher, a group in which Psychosocial Well-being Index Short Form(PWI-SF) are higher. The results show explanatory power of 32.5%. The results of the study indicate that the efforts, to increase RES, and to decrease MFS and PWI, are required to improve the depression among administrative staff in general hospital. These results could be used in organizing human resource management and industrial health education to lower the level of depression in general hospital administration staff. Following studies need to analyze the structural equation model that effects the depression levels of administrative staff in general hospital.

• The Journal of the Korea Contents Association
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• v.12 no.5
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• pp.331-345
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• 2012

The main purpose of this study is to investigate the effects of operational practices of contract foodservice management company on relationship quality and recontract intention. To verify research model, 126 data were collected from client companies of E contract foodservice management company and analyzed using structural equation modeling and multiple regression. The results of this study can be summarized as follows. First, direct factors such as operational costs, menu management, and service management had significant influences on food service quality. On the other hand, indirect factors such as operational supportability, brand image, and capacity of sales management were not important to food service quality. Second, indirect operational practices had significant effects on trust. That is, when operational supportability was increased, brand image was enhanced, and capacity of sales management was strengthened, client company's trust on contract foodservice company was increased. Among them, brand image showed the highest effect. Also, direct practices such as operational costs, menu management, and sanitary/facilities management significantly influenced on trust. Third, food service quality significantly affected trust. Finally, only trust had significant effect on recontract intention but food service quality did not. This means that food service quality alone is not enough to earn recontract intention. Relationship marketing efforts to form trust should be made between contract foodservice company and client company.

• Korean Journal of Food Science and Technology
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• v.25 no.1
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• pp.28-32
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• 1993

In order to elucidate the temperature and pressure effect on the oil expression of perilla seed, recovery of expressed oil (REO) and volumetric strain of both roasted and unroasted perilla seeds were observed at different temperature, pressure and for different periods of press. In this experiment, moisture content of perilla seed was adjusted to 2.5% and temperature used were 30, 40, 50 and $60^{\circ}C$. Pressure applied were 10, 30, 50 and 70 MPa, and periods of press were 5, 7, 9 and 11 min. As temperature and pressure were increased or periods of press was lengthened, REO and volumetric strain of pressed cake were increased. Maximum REO of unroasted perilla seeds were found to be 85.59% and those of roasted perilla seeds be 85.30%, at 70 MPa, $60^{\circ}C$, and for 11 min. Viscosity of expressed oil were exponentially dependent on temperature and REO were increased as viscosity was decreased. From statistical analysis between effects of expression factors and REO and volumetric strain of pressed cake, importance of their effects was decreased in the order of pressure, temperature, $temperature{\times}pressure$ and periods of press. The multiple regression equation between REO(Y) and temperature (T), pressure (P), and periods of press (D) were as follows; $Y=7.95+36.85P+1.12T^2-0.55TP-5.08P^2\;r^2=0.97$ for unroasted perilla seed (p<0.01), $Y=4.50T+39.23P+0.83T^2-1.71P-5.07P^2\;r^2=0.99$ for roasted perilla seed (p<0.01).

• Journal of Digital Convergence
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• v.15 no.8
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• pp.277-287
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• 2017

The purpose of this study was to identify acculturative stress, social support and self esteem in migrant workers. The data of 181 subjects were collected from June 1st to September 27, 2016, and analyzed using the SPSS WIN 23.0 program. Results: There was a significant negative correlation among acculturative stress, social support(r=-.465, p<.001) and self esteem(r=-353, p<.001). Stepwise multiple regression analysis showed self esteem(${\beta}=-.21$, p<.001) and job(${\beta}=-.02$, p<.05) were significant factors affecting acculturative stress(F=27.672, p<.001). The results of the study indicate that the efforts, to improve self esteem, and to increase social support, are required to decrease acculturatives stress among migrant wokers. The results are expected to be utilized in development of supportive program for migrant workers adaptation. In the following study, the analysis of structural equation modeling about additional factors of acculturative stress among migrant workers will be needed.