• Journal of Convergence for Information Technology
• /
• v.10 no.11
• /
• pp.156-167
• /
• 2020

The purpose of this study is to analyze the influence of the mindset on stress and job performance. For the analysis, a questionnaire is conducted for cabin crew members in K airlines, and a total of 266 copies are used for the final analysis. To verify the hypotheses of the study, frequency analysis, exploratory factor analysis, reliability analysis, confirmatory factor analysis, measurement model analysis, validation of the measuremen model, and structural equation model analysis are used based on the questionnaire. First, it is confirmed that the mindset had a negative (-) effect on the cabin crew's role stress, reward stress and relationship stress. Second, it is found that cabin crew's reward stress have a negative (-) effect on job performance. On the other hand, relationship stress is found to have a positive influence on job performance and there is no significant result in effect with role stress. Third, the mindset showes a significant positive impact relationship on job performance. As a result, it is necessary to introduce a mindset intervention program so that it can be applied in practical work. These research results confirm the positive effects of mindsets and show that they contribute to organizational performance. In addition, it is necessary to prepare a program to change the mindset of airline cabin crew and to be applied in actual work.

• Journal of Environmental Health Sciences
• /
• v.49 no.2
• /
• pp.89-98
• /
• 2023

Background: Organophosphorus flame retardants (OPFRs) are a group of chemical substances used in building materials and plastic products to suppress or mitigate the combustion of materials. Although OPFRs are generally used in mixed form, information on their mixture toxicity is quite scarce. Objectives: This study aims to elucidate the toxicity and determine the types of interaction (e.g., synergistic, additive, and antagonistic effect) of OPFRs mixtures. Methods: Nine organophosphorus flame retardants, including TEHP (tris(2-ethylhexyl) phosphate) and TDCPP (tris(1,3-dichloro-2-propyl) phosphate), were selected based on indoor dust measurement data in South Korea. Nine OPFRs were exposed to the luminescent bacteria Aliivibrio fischeri for 30 minutes and the human hepatocyte cell line HepG2 for 48 hours. Chemicals with significant toxicity were only used for mixture toxicity tests in HepG2. In addition, the observed EC_x values were compared with the predicted toxicity values in the CA (concentration addition) prediction model, and the MDR (model deviation ratio) was calculated to determine the type of interaction. Results: Only four chemicals showed significant toxicity in the luminescent bacteria assays. However, EC₅₀ values were derived for seven out of nine OPFRs in the HepG2 assays. In the HepG2 assays, the highest to lowest EC₅₀ were in the order of the molecular weight of the target chemicals. In the further mixture tests, most binary mixtures show additive interactions except for the two combinations that have TPhP (triphenyl phosphate), i.e., TPhP and TDCPP, and TPhP and TBOEP (tris(2-butoxyethyl) phosphate). Conclusions: Our data shows OPFR mixtures usually have additivity; however, more research is needed to find out the reason for the synergistic effect of TPhP. Also, the mixture experimental dataset can be used as a training and validation set for developing the mixture toxicity prediction model as a further step.

• Korean Journal of Social Welfare
• /
• v.57 no.3
• /
• pp.305-335
• /
• 2005

This paper is a result from validation study for SPDA(A Screening Scale For Potential Drug-use Adolescents) created in 2003 and newly developed during 2004. SPDA aims to screen adolescents in their early stage of drug-use and to help practitioners make a preventive approach for the adolescents. 4307 junior and senior high school students were selected as primary research subjects by stratified and quota sampling methods. 305 adolescents on probation were also selected as a comparison group and asked to answer the same questionnaire. Reliability for SPDA recorded 0.914, which proved to be better than previous year's (0.898). Exploratory and confirmatory factor analyses to test construct validity proved that SPDA could be divided into 7 factors and that each factor structure of SPDA could be a proper measurement model with high level of fitness and factor loadings. Discriminant analysis to test predictive validity confirmed that SPDA could classify the adolescents excellently by the frequency of drug-use, with hit ratio of 86.6 percent(78.8% and 87.4% for junior and senior high school students respectively). For concurrent validity test, Hare Home Self-Esteem Scale, Hare School Self-Esteem, Zuckerman-Kuhlman Sensation-seeking Scale were employed to find correlation with SPDA and all the three scales had significant Pearson correlation coefficients with SPDA. Known-groups validity test indicated that SPDA had an adequate power to classify out adolescents on probation from those in schooling, with a hit ratio of 71.8 percent. Cut-off point to detect adolescents with high risk of substance use was 77, which indicated approximately T score, 55 (0.5 SD), satisfying sensitivity, specificity, and efficiency criteria.

• Journal of Distribution Science
• /
• v.9 no.2
• /
• pp.61-72
• /
• 2011

The object of this research is to examine the factors leading to intercompany win-win by finding the antecedents and consequences that affect a supplier's fairness perception. We assume that the antecedent factors of a supplier's fairness perception are vertical coordination, cooperation support, information sharing, and legalistic plea. We assume that the consequential factors of a supplier's fairness perception are supply chain dependence and supply chain flexibility. The object industry is an electronic parts manufacturing company. We tested our model by using the SPSS 17.0 and the LISREL 8.5. For measurement validation, we verified by using a confirmatory factor analysis and a reliability analysis. For hypothesis analysis, we did a path analysis with the LISREL 8.5. By checking the modification index and expecting parameter changes, we modified the model. First, the buyer's vertical coordination had a positive effect on the supplier's distributive fairness perception and procedural fairness perception. Second, the buyer's cooperation support had no effect on the supplier's distributive fairness perception and procedural fairness perception: we suppose that the buyer's requests were burdensome, although they cooperated with the supplier. Third, the buyer's information sharing had a positive effect on distributive fairness perception but had no direct effect on procedural fairness perception. Fourth, the buyer's legalistic plea had a negative effect on the supplier's distributive fairness perception. and a negative effect on the supplier's procedural fairness perception at a 0.1 significance level. Fifth, although procedural fairness perception had no direct effect on supply chain dependence, fairness perception had an effect on supply chain dependence and supply chain flexibility both directly and indirectly.

• Journal of the Korean Society for Railway
• /
• v.16 no.1
• /
• pp.7-13
• /
• 2013

A scaled version of a roller rig is developed to demonstrate the dynamic characteristics of a railway vehicle for academic purposes. This rig is designed based on Jaschinski's similarity law. It is scaled to 1/10 of actual size and allows 9-DOF motion to examine the up and down vibration of a train set. The test rig consists of three sub-hardware components: (i) a driving roller mechanism with a three-phase AC motor and an inverter, (ii) a bogie structure with first and second suspensions, and (iii) the vehicle body. The motor of the rig is capable of 3,600rpm, allowing the test to simulate a vehicle up to a maximum speed of 400Km/hr. Because bearings and joints are properly connected to the sub-structures, various motion analyses, such as a lateral, pitching, and yawing motion, are allowed. The slip motion between the rail and the wheel set is also monitored by several sensors mounted in the rig. After the construction of the hardware, an experiment is conducted to obtain the natural frequencies of the dynamic behavior of the specimen. First, the test rig is run and data are collected from six sets of accelerometers. Then, a numerical analysis of the model based on the ADAMS program is derived. Finally, the measurement data of the first three fundamental frequencies are compared to the analytical result and the validation of the test rig is conducted. The results show that the developed roller rig provides good accuracy in simulating the dynamic behavior of the vehicle motion. Although the roller rig designed in this paper is intended for academia, it can easily be implemented as part of a dynamic experiment of a bogie and a vehicle body for a high-speed train as part of the research efforts in this area.

• Journal of dental hygiene science
• /
• v.9 no.1
• /
• pp.53-59
• /
• 2009

Infection control is now recognized as an important quality indicator in dental health service setting. The purpose of this study was to develop and validate Dental Hygienist's Infection Control Practice Scale for quality management of dental health service in Korea. The data of 254 dental hygienists was subjected to exploratory factor analysis using SPSS 16.0 and confirmatory factor analysis using AMOS 16.0. The total items of preliminary scale were 21 items and 5 subscale. Principal component analysis was completed with Varimax rotation. The results show a change in factor structure from 5 factor solution to 4 factor solution. The confirmatory factor analysis confirmed the four subscales(Immunization and periodic tests, Clinical procedure, Handwashing, Personal protection) which have a total of 12 items. After the item deleted because factor loading was low, measured model was tested. The results of the measurement model indicated fit indices: $x^2$= 79.593(df = 38, 0 = 0.000), RMR = 0.045, GFI = 0.940, CFI = 0.904, AGFI = 0.896, NFI = 0.837, TLI = 0.861, RMSEA = 0.67. The squared correlation between four constructs were less than the average variance extracted(AVE) of four constructs. Multiple regression analysis was completed. Dependent variable was the perceived infection control practice by dental hygienist. Independent variables were four summated subscales(R = 0.552, $R^2$= 0.304, Adjusted $R^2$= 0.431, F = 25.813, p = 0.000). Unstandardized coefficients of three independent variables were statistically significant.

• The Journal of the Convergence on Culture Technology
• /
• v.6 no.4
• /
• pp.245-252
• /
• 2020

Recently, as the income level of consumers increases, interest in tourism products has increased, competition among tourist destinations has been fierce. Storytelling ads are drawing attracting attention as one of the ways to establish differentiated positioning for tourism products. This study investigates the role of the involvement of tourism activity in the storytelling ads effects, and examines the effects of the attitude toward storytelling ads on tourist destination commitments, visit intention and SNS WOM (word-of-mouth) intention. This study also empirically tests the role of mental simulation in the relationship between storytelling ads attitudes and visit intention. A total of 255 usable responses were obtained from a sample of 270 consumers aged 18 or older in South Korea. Following the two-stage approach of model validation, measurement validity of each construct appearing in the structural model and hypothesized structural paths were tested. The findings show that all hypotheses are supported except H3 that posits the impact of attitude toward the storytelling ads on visit intention and mental simulation showed a moderate effect on the relationship between ads attitude and visit intention in the case of rational appeal. This study suggests that the production of storytelling ads of tourist destinations can be effective strategy to improve regional competitiveness and increase visit and SNS WOM intention.

• 재활복지
• /
• v.21 no.1
• /
• pp.253-277
• /
• 2017

The purpose of this study was to develop the Constraints in Physical Activity Scale for people with physical Disabilities(CPASD) which measures the constraints in physical activity of people with physical disabilities. For this study, the 5 step analytic framework of unified validity developed by Messick (1995), the framework for conducting a strong program of construct validation by Benson (1998) method were applied. Furthermore, the validity of CPASD was systematically presented by applying common factor model and measurement model to 264 persons with physical disabilities. The conclusion based on the results and discussions of this study is as follows. First, CPASD presented evidence of job validity. Four factors (17 items) were developed, consisting of leader constraints, economic constraints, prejudice, and exercise environment constraints through the analysis of the factor structure and the fit of factor coefficients. Second, the factor structure of the developed CPASD (leader constraint, economic constraint, prejudice, exercise environment constraint) was statistically distinguished and stably reflected the existing exercise participation constraints theory. Third, the developed CPASD presented evidence of the validity of the criteria. Leader constraints and prejudice were negatively correlated with positive motor emotions, leader constraints, prejudice, and exercise environment constraints were positively correlated with negative motor emotions. Therefore, in future research, it is necessary to reevaluate the current system and actual condition related to leader constraints, economic constraints, prejudices, and exercise environment constraints derived as factors of CPASD. To do this, it is necessary to judge the degree of reality based on the causal relationship verification and IRT theory using CPASD.

• Journal of Bio-Environment Control
• /
• v.31 no.2
• /
• pp.98-103
• /
• 2022

Non-destructive estimation of leaf area is a more efficient and convenient method than leaf excision. Thus, several models predicting leaf area have been developed for various horticultural crops. However, there are limited studies on estimating the leaf area of strawberry plants. In this study, we predicted the leaf areas via nonlinear regression analysis using the leaf lengths and widths of three-compound leaves in five domestic strawberry cultivars ('Arihyang', 'Jukhyang', 'Keumsil', 'Maehyang', and 'Seollhyang'). The coefficient of determination (R²) between the actual and estimated leaf areas varied from 0.923 to 0.973. The R² value varied for each cultivar; thus, leaf area estimation models must be developed for each cultivar. The leaf areas of the three cultivars 'Jukhyang', 'Seolhyang', and 'Maehyang' could be non-destructively predicted using the model developed in this study, as they had R² values over 0.96. The cultivars 'Arihyang' and 'Geumsil' had slightly low R² values, 0.938 and 0.923, respectively. The leaf area estimation model for each cultivar was coded in Python and is provided in this manuscript. The estimation models developed in this study could be used extensively in other strawberry-related studies.

• Korean Journal of Culture and Social Issue
• /
• v.30 no.2
• /
• pp.159-192
• /
• 2024

The purpose of this study is to validate the Reactive-Proactive Aggression Questionnaire (RPQ), a tool for measuring reactive-proactive aggression, in the context of South Korea. A thorough translation was conducted in collaboration with the original author. An exploratory factor analysis (EFA), exploratory structural equation modeling (ESEM), rating scale model (Rasch), differential item functioning (DIF), and convergent validity were performed on a sample of 510 South Korean individuals. The results revealed a two-factor structure of reactive and proactive aggression after removing one item showing dual loading. Rating scale analysis based on the Rasch model indicated the appropriateness of the 3-point Likert scale, with all items meeting fit criteria. Although the separation index and separation reliability of proactive aggression was marginally lower, the overall discrimination between participants and items was satisfactory. Examination of participant-item distribution indicated a suitable alignment between reactive aggression and participant ability levels, whereas proactive aggression exhibited slightly elevated item difficulty. Furthermore, three items were found to function differently based on gender. A moderate but statistically significant positive correlation was found between the Barratt Impulsiveness Scale-11-R (Korean version) and RPQ from the results of the convergent validity evaluation. Overall, this study employed rigorous statistical methods to validate the suitability of the RPQ for use in Korea, taking cultural nuances into account, and introduced the concepts of reactive and proactive aggression to the Korean general population.