• The Journal of Society for e-Business Studies
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• v.15 no.2
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• pp.137-166
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• 2010

A virtual team is defined a group of people that use electronic communications for some or all of their interactions with other team members. Because team members of a virtual team are physically and temporally distributed, a team's transactive memory system(TMS) is considered to be crucial for the team's effectiveness and performance. TMS refers to a set of individual memory systems which integrate knowledge possessed by particular members through a shared awareness of who knows what. This paper seeks to understand (1) how a virtual team's TMS influences team performance, and (2) what factors contribute to developing the team's TMS. Given these purposes, through the extensive literature review, we first identified components and antecedents to develop a theoretical model that predicts a virtual team's performance. Using the survey data gathered from 172 virtual teams, this study found that expertise location, coordination, and cognition-based trust which were proposed as three components of TMS positively influenced a virtual team's performance. Furthermore, this study uncovered that perceived media richness, network tie strength, and shared norms significantly influenced the components of TMS, while geographical dispersion did not exert any significant influence on TMS.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.364-372
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• 2016

This study examined the multi-phrased effects and outcomes of adult female learners who participated in lifelong learning activities, as well as the proposed structural relationships among the five latent variables. Questions established to achieve the purpose of the study are as follow: What effects do the learner's characteristics, lifelong education institutions, learning flow, and learning satisfaction have on the learning come? The participants of the survey numbered 632, but 54 respondents who were unreliable or did not complete their survey were excluded. A total of 578 cases were analyzed for this research. The structural relationships among the five latent variables-learner's characteristics, lifelong education institutions, learning flow and learning satisfaction, and learning outcome of the adult female learners-AMOS 18.0 program were also used for structural analysis. The major findings of this research are as follows. First, the model fitness showed that the hypothetical model provided a reasonable fit to the data ${\chi}^2=224.267$ (df=69, p<.001), RMSEA=.062, TLI=.943, RFI=.920, CFI=.957, IFI=.957, NFI=.939. Second, the learner's characteristics ( =.218, p<.001) and lifelong education institutions ( =.301, p<.001) have a direct effect on the learning outcomes. The learning flow ( =-.149 p=.541) does not have a direct effect on the learning outcome. Learning satisfaction ( =.405 p<.001) have a direct effect on the learning outcome. To put findings above together, in respect to adult female learners' performances, the learning outcomes are influenced directly by the learner characteristics, conditions of the lifelong education institutions, and learning satisfaction, whereas satisfaction indirectly affects the learners' learning outcome.

• Journal of Korea Water Resources Association
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• v.49 no.2
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• pp.155-164
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• 2016

Algal blooms not only destroy fish habitats but also diminish biological diversity of ecosystem which results into water quality deterioration of 4 major rivers in South Korea. The relationship between algal bloom and environmental factors had been analyzed through the cross-correlation function between concentration of chlorophyll a and other environmental factors. However, time series of cross-correlations can be affected by the stochastic structure such auto-correlated feature of other controllers. In order to remove external effect in the correlation analysis, the pre-whitening procedure was implemented into the cross correlation analysis. The modeling process is consisted of a series of procedure (e.g., model identification, parameter estimation, and diagnostic checking of selected models). This study provides the exclusive correlation relationship between algae concentration and other environmental factors. The difference between the conventional correlation using raw data and that of pre-whitened series was discussed. The process implemented in this paper is useful not only to identify exclusive environmental variables to model Chl-a concentration but also in further extensive application to configure causality in the environment.

• Magazine of the Korean Society of Agricultural Engineers
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• v.37 no.3_4
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• pp.34-47
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• 1995

It is experienced fact as a regular annual event that the structure to he designed on unreasonable flood for the agricultural structures including reservoirs have been brought not only loss of lives, but also enormous property damage. For the solution of this problem at issue, this study was conducted to develop an optimal runoff hydrograph model by comparison of the peak flows and time to peak between observed and simulated flows derived by linear time-invariant and linear time-variant models under the condition of having a short duration of heavy rainfall with uniform rainfall intensity at nine small watersheds which are within the range of 55.9 to 140.7 square kilometers in area in Han, Geum, Nagdong and Yeongsan Rivers. The results obtained through this study can be summarized as follows. 1. Storage constants and Gamma function arguments were calculated within the range of 1.2 to 6.42 and of 1.28 to 8.05 respectively by the moment method as the parameters for the analysis of runoff hydrograph based on linear time-invariant model. 2. Parameters for both linear time-invariant and linear time-variant models were calibrated with nine gaged watershed data, using a trial and error method. The resulting parameters including Gamma function argument, N and storage constant, K for linear time-invariant model were related statistically to watershed characteristic variables such as area, slope, length of main stream and the centroid length of the basin. 3. Average relative errors of the simulated peak discharge of calibrated runoff hydrographs by using linear time-variant and linear time-invariant models were shown to be 0.75 and 5.42 percent respectively to the peak of observed runoff hydrographs. Correlation coefficients for the statistical analysis in the same condition were shown to be 0.999 and 0.978 with a high significance respectively. Therefore, it can be concluded that the accuracy of a linear time-variant model is approaching more closely to the observed runoff hydrograph than that of a linear time-invariant model in the applied watersheds. 4. Average relative errors of the time to peak of calibrated runoff hydrographs by using linear time-variant and linear time-invariant models were shown to be 16.44 and 19.89 percent respectively to the time to peak of observed runoff hydrographs. Correlation coefficients in the same condition were also shown to be 0.999 and 0.886 with a high significance respectively. 5. It can be seen that the shape of simulated hydrograph based on a linear time- variant model is getting closer to the observed runoff hydrograph than that of a linear time-invariant model in the applied watersheds. 6. Two different models were verified with different rainfall-runoff events from data for the calibration by relative error and correlation analysis. Consequently, it can be generally concluded that verification results for the peak discharge and time to peak of simulated runoff hydrographs were in good agreement with those of calibrated runoff hydrographs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.264-273
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• 2016

This study examined the relationships among halitosis, stress and psychological status using a cross-sectional survey of 3,689 adolescents (1,805 male 1,884 female) from the 2010 Korean Survey on the Health of Youth and Children. The related factors of halitosis were checked and the path model was also examined using AMOS 19.0 programs. The prevalence of halitosis was 27.4%. Based on path analysis, the significant coefficients paths were as follows: $halitosis{\rightarrow}stress$, $halitosis{\rightarrow}depression$, $halitosis{\rightarrow}anxiety$, $halitosis{\rightarrow}tension$, $halitosis{\rightarrow}hostility$. Halitosis had an indirect effect on the psychological status linked to depression, anxiety, tension, and hostility via stress. Overall, the results provide stronger support for the halitosis impact of stress and psychological health. Moreover, the effective prevention of halitosis may be important for understanding the specific psychological factors.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.595-602
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• 2021

This study evaluates the impact of an information security policy sanction, a perceived threat, and the perception of the information security climate on a compliance behavioral intention. The research method was structured with a cross-sectional study design for the prospect and goal orientation. The variables used in the analysis are information security policy sanction, perceived threat, perception of information security climate, and compliance behavioral intention. Progress in this research consists of measuring the prospect and goal orientation, and then measuring the four variables. As a result, the prospect had a significant effect on the perception of the information security climate, and it was found that the influence of the gain-based condition was greater than the loss-based condition. Goal orientation had a significant effect on the information security policy sanction, the perceived threat, and the compliance behavioral intention, and the influence of the development-based condition was greater than the stability-based condition. Both prospect and goal orientation had an interactive effect on the compliance behavioral intention. The exploration model was verified as a mediation model. In addition, the discussion includes the appropriate implications for information security based on these research results.

• Industry Promotion Research
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• v.8 no.4
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• pp.47-60
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• 2023

The purpose of this study is to examine the causal relationship between self-efficacy and safety consciousness of health belief factors and how they affect the disaster prevention behavior of construction workers using TBM. To this end, a research model is presented that applies the main variables of the Health Belief Theory, a social psychological health behavior change model developed to predict and explain health-related behaviors. To empirically verify the research model of this study, a survey was conducted among construction workers who have experience in using TBMs for chemical plant construction. The results showed that, first, the perceived severity of construction workers utilizing chemical plant construction has a significant effect on self-efficacy and safety consciousness; second, the perceived probability of construction workers utilizing chemical plant construction has a significant effect on self-efficacy and safety consciousness. Third, the perceived obstacles of construction workers utilizing chemical plant construction have a significant effect on self-efficacy and safety consciousness. Fourth, the perceived benefits of construction workers utilizing chemical plant construction were found to have a significant effect on self-efficacy and safety awareness. The purpose of this study is to reduce critical accidents through disaster prevention behavior of chemical plant construction workers through TBM.

• Journal of the Korean Society of Child Welfare
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• no.36
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• pp.289-322
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• 2011

The purpose of this study is to examine the relationship between job characteristics such as role conflict, workload, and self-efficacy, secondary traumatic stress(STS), and burnout of social-workers who are working with survivors of child abuse, spouse abuse and sexual assault. While burnout has been studied over two decades all over the world, secondary traumatic stress(STS) is a less familiar term in the field of social work. Studies explaining the relationship between job-demands, STS, and burnout for social workers working with violence victims lack integrative insights across agencies serving children and adults. Thus, we examine whether the relationships between change based on wheter the survivor is a child or an adult. Two hundred thirty three social workers in Korea who work with violence victims participated in the survey. The data were analyzed with Amos 7.0. Results indicate that STS plays a key role in explaining social worker burnout across the agencies, and Child Protective Service workers were found to have the highest STS symptoms. The pathways to social worker burnout proved to be different based on who you served. Theoretical and practical implications of these findings were discussed.

• Korean Journal of Culture and Social Issue
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• v.18 no.4
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• pp.435-462
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• 2012

The predominant concern of the study centers on: (1) the direct effects of the job satisfaction, social support and hope on the individual's quality of life; (2) the direct effect of hope alone on the individual's quality life; (3) the mediating effect of the hope between the job satisfaction/social support and life quality; (4) the moderating effect of the worker's legal status(legal labors Vs. illegal labors) on each causal relationship. Research is based on a survey conducted with 453 Mongolian immigrant workers(333 legal workers, 120 illegal workers) from 10 cities including Seoul. In order for respondents to address research questions, structural equation models are explored. A variety of tests are conducted(metric invariance test, critical ratio for difference test, multi-group analysis, bias-corrected boot-strapping, latent mean analysis including Cohen's effect test). The noticeable findings are as follow: First, both job satisfaction and social support have a positive influence respectively on the individual's hope and the individual's quality of life. Second, we found a partial mediating effect of hope between both job satisfaction/social support and the individual's life quality. Third, we failed to find a moderating effect of the workers' legal status on each causal relationship. Finally, there is no significant difference of the latent means of each latent variable -job satisfaction, social support, hope, and life quality - between the legal group and the illegal group, except the latent mean of workers' quality of life. A range of practical and political implications are discussed based on the study's findings.

• The Korean Journal of Nuclear Medicine
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• v.34 no.1
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• pp.82-93
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• 2000

Purpose: We characterized the signals obtained from the components of a small gamma camera using Nal(Tl)-position sensitive photomultiplier tube (PSPMT) and optimized the parameters employed in the modules of the system. Materials and Methods: The small gamma camera system consists of a Nal(Tl) crystal ($60{\times}60{\times}6mm^3$) coupled with a Hamamatsu R3941 PSPMT, a resister chain circuit, preamplifiers, nuclear instrument modules (NIMs), an analog to digital converter and a personal computer for control and display. The PSPMT was read out using a resistive charge division circuit which multiplexes the 34 cross wire anode channels into 4 signals (X+, X-, Y+, Y -). Those signals were individually amplified by four preamplifiers and then, shaped and amplified by amplifiers. The signals were discriminated and digitized via triggering signal and used to localize the position of an event by applying the Anger logic. The gamma camera control and image display was performed by a program implemented using a graphic software. Results: The characteristics of signal and the parameters employed in each module of the system were presented. The intrinsic sensitivity of the system was approximately $8{\times}10^3$ counts/sec/${\mu}Ci$. The intrinsic energy resolution of the system was 18% FWHM at 140 keV. The spatial resolution obtained using a line-slit mask and $^{99m}Tc$ point source were, respectively, 2.2 and 2.3 mm FWHM in X and Y directions. Breast phantom containing $2{\sim}7mm$ diameter spheres was successfully imaged with a parallel hole collimator. The image displayed accurate size and activity distribution over the imaging field of view Conclusion: We proposed a simple method for development of a small gamma camera and presented the characteristics of the signals from the system and the optimized parameters used in the modules of the small gamma camera.