• The Korean Journal of Pesticide Science
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• v.6 no.4
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• pp.300-308
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• 2002

This study was conducted to investigate the downward mobility of pesticides using soil colunms and to compare the experimental results with predicted values from Convective mobility test model. Five pesticides including ethoprophos, procymidone, iprobenfos, isoprothiolane, and butachlor were subjected to soil column leaching test for three types of cultivation soils. The concentrations of ethoprophos, iprobenfos, procymidone, isoprothiolane and butachlor leached from soil column of 30 cm depth ranged $0.74{\sim}3.61mg/mL,\;0.36{\sim}1.67mg/L,\;0.16{\sim}0.84mg/L,\;0.16{\sim}0.67mg/L$ and lower than 0.15 mg/L, respectively. Elution volume to reach the peak of ethoprophos, iprobenfos, procymidone, isoprothiolane and butachlor in the leachate ranged $2{\sim}4PV,\;3{\sim}10PV,\;5{\sim}13PV,\;4{\sim}14PV\;and\;19{\sim}61PV$, respectively. Convection times predicted by Convective mobility test model at standard conditions were $9{\sim}18$ days for ethoprophos, $17{\sim}35$ days for iprobenfos, $24{\sim}54$ days for isoprothiolane, $21{\sim}65$ days for procymidone and $105{\sim}279$ days for butachlor. Based on these convection times, ethoprophos was classified as mobile or most mobile, isoprothiolane and procymidone as moderately mobile or mobile and butachlor as slightly mobile. On the same conditions, convection times from the model were coincided with those from soil column test in most of the soil-pesticide combinations applied. Therefore, Convective mobility test model could be applied to predict convection times of pesticides.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.4
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• pp.39-58
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• 2019

This study performed the dam watershed storm runoff modeling using GPM(Global Precipitation Measurement) satellite rain and KIMSTORM2(KIneMatic wave STOrm Runoff Model 2) distributed model. For YongdamDam watershed(930㎢), three heavy rain events of 25th August 2014, 11th September 2017, and 26th June 2018 were selected and tested for 4 cases of spatial rainfalls such as (a) Kriging interpolated data using ground observed data at 7 stations, (b) original GPM data, (c) GPM corrected by CM(Conditional Merging), and GPM corrected by GDA(Geographical Differential Analysis). For the 4 kinds of data(Kriging, GPM, CM-GPM, and GDA-GPM), the KIMSTORM2 was calibrated respectively using the observed flood discharges at 3 water level gauge stations(Cheoncheon, Donghyang, and Yongdam) with parameters of initial soil moisture contents, stream Manning's roughness coefficient, and effective hydraulic conductivity. The total average Nash-Sutcliffe efficiency(NSE) for the 3 events and 3 stations was 0.94, 0.90, 0.94, and 0.94, determination coefficient(R²) was 0.96, 0.92, 0.97 and 0.96, the volume conservation index(VCI) was 1.03, 1.01, 1.03 and 1.02 for Kriging, GPM, CM-GPM, and GDA-GPM applications respectively. The CM-GPM and GDA-GPM showed better results than the original GPM application for peak runoff and runoff volume simulations, and they improved NSE, R², and VCI results.

• Journal of the Korean Society of Radiology
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• v.14 no.5
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• pp.603-612
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• 2020

This study has a purpose to look into the effect of the relationship between the Tube current (mA) and SOD(Source to Object Distance), which is a parameter of lower limb angiography examination, and the dilution rate of the contrast medium concentration (300, 320, 350) on the image. To that end, using 3 mm vessel model water phantom, a vessel model custom made in the size of peripheral vessel diameter, this study measured relationships between change of parameters, such as tube current (mA), SOD and varying concentrations (300, 320, 350) of contrast medium dilution into SNR and CNR values while analyzing the coefficients of variance(cv<10). The software used to measure SNR and CNR values was Image J 1.50i from NIH (National Institutes of Health, USA). MPV (mean pixel value) and SD (standard deviation) were used after verifying numerically the image signal for region of interest (ROI) and background on phantom from the DICOM (digital imaging and communications in medicine) 3.0 file transmitted to PACS. As to contrast medium dilution by the change of tube current, when 146 mA and 102 mA were compared, For both SNR and CNR, the coefficient of variation value was less than 10 until the section of CM: N/S dilution (100% ~ 30% : 70%) but CM: N/S dilution rate (20%: 80% ~ 10% : 90%) the coefficient of variation was 10 or more. As to contrast medium dilution by concentration for SOD change, when SOD's (32.5 cm and 22.5 cm) were compared,For both SNR and CNR, the coefficient of variation value was less than 10 until the section of CM: N/S dilution (100% ~ 30% : 70%) but CM: N/S dilution rate (20%: 80% ~ 10% : 90%) the coefficient of variation was 10 or more. As to contrast medium dilution by concentration for SOD change, when SOD's (32.5 cm and 12.5 cm) were compared,For both SNR and CNR, the coefficient of variation value was less than 10 until the section of CM: N/S dilution (100% ~ 30% : 70%) but CM: N/S dilution rate (20%: 80% ~ 10% : 90%) the coefficient of variation was 10 or more. As a result, set a low tube current value in other tests or procedures including peripheral angiography of the lower extremities in the intervention, and make the table as close as possible to the image receiver, and adjust the contrast agent concentration (300) to CM: N/S dilution (30%: 70%). ) Is suggested as the most efficient way to obtain images with an appropriate concentration while simultaneously reducing the burden on the kidney and the burden on exposure.

• Korean Journal of Social Welfare
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• v.66 no.1
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• pp.333-361
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• 2014

By viewing donors for social welfare organization as both givers and beneficiaries, this study aims to address the correlations between the continuity of donors' contributions and enhanced sense of satisfaction as a consequence of participating in donation activities. The predominant concern of this study centers on: (1) the direct effects of individuals' emotional utility, demonstrable utility, trust toward donee organization, self acceptance on the continuation of their donation; (2) the direct effects of individuals' emotional utility, demonstrable utility, trust toward donee organizations on individuals' self-acceptance; (3) the direct effects of individuals' emotional utility, demonstrable utility on their trust toward a donee organization; (4) the indirect effects of individuals' self acceptance on two paths i.e. emotional utility${\rightarrow}$trust${\rightarrow}$self acceptance, and demonstrable utility${\rightarrow}$trust${\rightarrow}$self acceptance; (5) the indirect effects of individuals' individuals' trust toward donee organization on self acceptance on four paths i.e. emotional utility${\rightarrow}$trust${\rightarrow}$continuity of donation; demonstrable utility${\rightarrow}$trust${\rightarrow}$continuity of donation; emotional utility${\rightarrow}$trust${\rightarrow}$self-acceptance, and demonstrable utility${\rightarrow}$trust${\rightarrow}$self-acceptance; (6) the moderating effects of 'financial status' on the causal relationships in the prescribed structural equation model(SEM). In order to verify the moderating effect of 'financial status', multi-group analysis between each of the two groups were conducted. Research is based on a survey among 1116 donors who had made charitable, monetary contributions to social welfare organizations in Daegu and Kyungpook province. Data was collected from 29 organizations. In order to address the research questions, structural equation were employed. A variety of tests are conducted(metric invariance, critical ratio for difference, structural invariance, multi-group analysis, bias-corrected boot-strapping, latent mean analysis including Cohen's effect test).

• Management & Information Systems Review
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• v.37 no.3
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• pp.83-113
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• 2018

The purpose of this study to empirically examine a smart work investment and job performance by change resistance. Firstly, There investigates mediating role of the communication between the smart work investment and the job performance. Secondly, It will identify the job productivity differences through a level of organizational change resistance that reduced smart work investment. The smart work is to provide the flexibility of time and location and is a working method to improve a work productivity of organization members. The introduction of smart work means the adoption of new organizational culture, institution and technology and requires a novel change of a custom and pattern on existing organization culture and institution because of transformation form of communication and collaboration. The method of this study adopts a structural equation model to test a mediating effect of communication and a moderating effect of change resistance level. This model confirms whether smart work investments provide a positive impact on communication and organizational productivity. In addition, I will classify a change resistance level of smart work by cluster analysis and then check a critical path difference of job productivity between each group. As a result, The organizational IT, institution and culture on the smart work investment appeared to important influencers in communication and also had a direct influence of individual performance. Also, The three independent variables of smart work investment have an indirect influence of individual and organizational performance through communication mediating variables. However, the organizational IT and institution as independent variables do not provide direct influence of organization performance. Nevertheless, two independent variables of organizational IT and institution have an indirect influence the organization performance through communication mediating variables. As a result of confirming a productivity of three groups on organization resistance, there was a difference the individual and organizational performance among groups. The low-level group of organizational resistance showed high coefficient value of performance compared to other groups. The group analysis implications, The smart work investment appeared significantly to revise the institution first, build culture secondly and advanced technology lastly. The theoretical implication from this study contributes an extension of social science theory through socio-technical systems, institution, culture, change resistance and job performance based on smart work. The practical implications explain the smart work success in step-by-step investment rather than radical investment as level management of change resistance. In future research, the smart work performance between private and public firms will analyze a difference of the organizational culture, institution, technology and performance.

• Korean Journal of Social Welfare
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• v.61 no.2
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• pp.325-348
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• 2009

This study intends to investigate the main and mediating effects which caregiving appraisal and positive reappraisal exert on quality of life (QOL) of primary family caregivers of cancer patient considering the relationship with social support. The processes of this study areas follows. First, the variables which research model were chosen on the basis of stress-appraisal-coping theory through reviews of the previous studies. Second, a survey was conducted upon 295 primary caregiver of patient with cancer at National Cancer Center. Collected data were analyzed by SPSS 12.0 and SEM (Structural Equation Modeling) method using AMOS 5.0. The summary of the result is as follows. First, the entire model including measurement and structural model shows sufficient fit index of CFI(.951), TLI(.940) and RMSEA(.062). Second, the results of analysis of direct effects among variables are as follows. The 'Social support' has statistically significant direct effect on the 'feeling of burden' and 'growth'. The 'feeling of burden' has statistically significant direct effect on the 'growth' and 'QOL-mental and physical'. The 'growth' has statistically significant direct effect on the 'QOL-mental'. Third, the results of analysis of mediating effects of the 'social support and QOL' and 'feeling of burden and QOL' are as follows. The effects of 'social support' on 'QOL-mental' are significantly mediated by the 'feeling of burden' and 'growth'. The effects of 'social support' on 'QOL-physical' are significantly mediated by the 'feeling of burden'. The effects of 'feeling of burden' on 'QOL-mental' are significantly mediated by 'growth'. Through this research, these implications in social work study and practice are found: (1) this study extended the scope of study in the caregiver's health area from negative sides into positive ones by using growth variables as positive reappraisalof caregiving in research model, which has not been tried on the Korean family caregivers of the cancer patient. (2) The effects of positive reappraisal on QOL-mental can provide a foundational necessity for social workers to help family caregivers find positive meaning in their caregiving experience. This approach of social work practice will improve QOL of family caregivers. (3) This study present a framework including social support, negative appraisal, positive reappraisal, and QOL variables available to social work practice and explaining affective relationships among these variables in various aspects.

• Journal of the Korean Society for information Management
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• v.36 no.1
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• pp.137-168
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• 2019

This study measures and analyzes the university library user's sense of community, service quality assessment, user satisfaction and loyalty. In addition, the effect of the university library user's sense of community on university library user satisfaction and loyalty mediated by the assessment of the quality of service is investigated. On the basis of study result, to improve user satisfaction and user loyalty, the direction and implications of library development are presented. In order to achieve the purpose of the study, precedent research and literature were investigated, and the study model and hypothesis were established based on theoretical background. In order to verify the hypothesis, a total of 300 questionnaires were distributed to subject who had experience using the Central Library among undergraduate students at the C National University, and the final 282 sample was used for analysis. To analyze the differences depending on the general characteristics of the samples, It is the result of an independent sample t-test and one-way ANOVA. The results of the mediated effects analysis using the PROCESS macro-programs models 4 and 6 of Hayes for hypothesis testing are as follows. First, The university library user's sense of community (Service Benefits Perception and Satisfaction, Mutual sense of influence) effect the user satisfaction of university library mediated by service quality assessment at statistical significance. This showed that the higher the university library user's sense of community, the higher the service quality assessment, and the higher the user satisfaction level of university library. Second, The university library user's sense of community (Service Benefits Perception and Satisfaction, Mutual sense of influence) effect the user loyalty of university library mediated by service quality assessment and user satisfaction. This showed that the higher the university library user's sense of community, the higher the service quality assessment, the higher user satisfaction level of university library and the higher the user loyalty level of university library. The results of this study showed that the university library user's sense of community has a direct and indirect effect on enhancing user satisfaction and loyalty through the service quality assessment.

• Journal of the Korea Convergence Society
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• v.10 no.12
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• pp.337-343
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• 2019

The need for preparation for old life has been further increased due to the increase of the elderly population and changes in economic conditions today. The purpose of this study is to analyze the relationship between income instability and the degree of preparation for old life and satisfaction of current life. The key variables were extracted through prior study review. And the data collected through the survey were statistically analyzed with a structural equation model. The analysis found that the indirect effect of the current income risk on the satisfaction of current life through the preparation for old life had a significant negative effect under the statistically significant level of 0.05. However, it was found that the direct effects of current income risk on the satisfaction of current life were not statistically significant. An additional analysis was conducted by dividing the age, the number of dependents by two groups respectively. To summarize the results, preparation for old life played a significant role as a prerequisite for improving the satisfaction of current life. And the variability(risk) of current income played an important role in preparing for old life. At this time, the degree of relevance between the factors(potential variables) differed somewhat between the two groups. The results of this analysis will be meaningful in providing basic source of data to prepare for a satisfactory life in each individual's current situation. This study, meanwhile, has limitations that have only been done with cross-sectional analysis and would like to analyze time-series changes in the future.

• Korean Security Journal
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• no.51
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• pp.127-149
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• 2017

The purpose of this study was to investigate the relationship between psychological capital on job attitudes. For this purpose, the private security guards who were working at private security companies in Gyeonggi province from September to October, 2016 were selected as the population and the convenience sampling method was used for 310 persons. A total of 295 copies of the questionnaire were used for the final analysis, except for 15 questions that were answered in appropriately or were partially missing. Data were analyzed by frequency analysis, confirmatory factor analysis, correlation analysis and structural equation modeling using SPSS 21.0 and AMOS 21.0. The results are as follows. First, the positive psychological capital of the private security guard has a positive(+) effect on job satisfaction. Second, the positive psychological capital of the private security guard has a positive(+) effect on job commitment. Third, job satisfaction of the private security guards has a positive(+) effect on job commitment. Fourth, job satisfaction is partly mediated in the relationship between positive psychological capital and job commitment. In summary, the positive psychological capital of the private security guard is an important variable that positively affects job satisfaction and job commitment, and the higher the job satisfaction of the private security guard, the higher the commitment to the job.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.25 no.1
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• pp.85-105
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• 2014

The purpose of this study is to identify the factors that influence users' intention to use mobile services in academic libraries, based on the Davis' Technology Acceptance Model. This study employed both perceived usefulness and perceived ease of use, which were core variables in TAM, and added perceived playfulness that was recently applied to many researches on mobile system acceptance intention. As external variables, ubiquitous ability, context awareness, and mobile internet self-efficacy were employed. The data was collected from 325 surveys from two academic libraries and was analyzed with SPSS 18.0 and AMOS 21.0. As a result, perceived usefulness was the most significant factor in predicting users' acceptance intention and perceived ease of use was an indirect determinant of service usage. But perceived playfulness was not significantly correlated. Ubiquitous ability among external variables had a significant effect on perceived usefulness, context awareness did on both perceived playfulness and ease of use, and mobile internet self-efficacy did on perceived ease of use. Based on the findings, this study discussed theoretical and practical implications in academic library mobile service area.