• Journal of Digital Convergence
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• v.17 no.5
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• pp.217-223
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• 2019

A study in predicting defects of spot welding in real time in automotive field is essential for cost reduction and high quality production. Welding quality is determined by shear strength and the size of the nugget, and results depend on different independent variables. In order to develop the real-time prediction system, multiple regression analyses were conducted and the two dependent variables were obtained with sufficient statistical results with three independent variables, however, the quality prediction by the regression formula could not ensure accuracy. In this study, a multi-layer neural network circuit was constructed. The neural network by 10 dynamic resistance variables was constructed with three hidden layers to obtain execution functions and weighting matrix. In this case, the neural network was established with three independent variables based on regression analysis, as there could be difficulties in real-time control due to too many input variables. As a result, all test data were divided into poor, partial, and modalities. Therefore, a real-time welding quality determination system by three independent variables obtained by multiple regression analysis was completed.

• Journal of Biosystems Engineering
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• v.38 no.1
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• pp.64-71
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• 2013

Purpose: The purpose of this study was to select standing posture parameters that have a significant difference according to the severity of spinal deformity, and to develop a novel Cobb angle prediction model for adolescent girls with idiopathic scoliosis. Methods: Five normal adolescents girls with no history of musculoskeletal disorders, 13 mild scoliosis patients (Cobb angle: $10^{\circ}-25^{\circ}$), and 14 severe scoliosis patients (Cobb angle: $25^{\circ}-50^{\circ}$) participated in this study. Six infrared cameras (VICON) were used to acquire data and 35 standing parameters of scoliosis patients were extracted from previous studies. Using the ANOVA and post-hoc test, parameters that had significant differences were extracted. In addition, these standing posture parameters were utilized to develop a Cobb-angle prediction model through multiple regression analysis. Results: Twenty two of the parameters showed differences between at least two of the three groups and these parameters were used to develop the multi-linear regression model. This model showed a good agreement ($R^2$ = 0.92) between the predicted and the measured Cobb angle. Also, a blind study was performed using 5 random datasets that had not been used in the model and the errors were approximately $3.2{\pm}1.8$. Conclusions: In this study, we demonstrated the possibility of clinically predicting the Cobb angle using a non-invasive technique. Also, monitoring changes in patients with a progressive disease, such as scoliosis, will make possible to have determine the appropriate treatment and rehabilitation strategies without the need for radiation exposure.

• Journal of Families and Better Life
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• v.22 no.3
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• pp.35-46
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• 2004

The purpose of this study was to examine the residents' opinions on the degree of importance, and satisfaction with, the managerial service of multi-family housing. Residents' participation in managerial activities was also examined, because residents' opinions should be taken into serious consideration in order to improve the efficiency of housing management. Research methods used in this study were survey, field study, and content analysis of professionals' opinions. Survey data of 520 residents who live in multi-family housing were analyzed by means, frequencies, correlation, chi-square tests, t-tests, one-way ANOVA, post-hoc estimation (Scheffee test), and regression. The major findings of this study were as follows: First, many residents were dissatisfied with the quality of managerial service, but they thought that managerial services were very important. For example, they thought that safety inspection of the playground was very important, yet the current level of service was not satisfactory. Second, the characteristics of residents that determined the degree of residential satisfaction were income the location of the residence, and degree of participation in the community events. Third, the residents generally did not want to participate in the managerial services and community programs through such activities as participation in resident committee. In order to improve the housing management efficiency, residents' participation is critical. Some participants in this study pointed out that the details of management service and future plans need to be made public. New management models need to be developed to promote residents' participation and increase their satisfaction in the management.

• Journal of Biosystems Engineering
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• v.36 no.3
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• pp.180-186
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• 2011

The objective of this research was to establish the estimation method of growth information on potato using Multi-Spectral Image Sensor (MSIS) and Global Positioning System (GPS). And growth estimation map for determining a prescription map over the entire field was generated. To determine the growth model, 10 ground-truth points of areas of $4m^2$ each were selected and investigated. The growth information included stem number, crop height and SPAD value. In addition, images information involving the ground-truth points were also taken by an unmanned helicopter, and reflectance value of Green, Red, and NIR bands were calculated with image processing. Then, growth status of potato was modeled by multi-regression analysis using these reflectance value of Green, Red, and NIR. As a result, potato growth information could be detected by analyzing Green, Red, and NIR images. Stem number, crop height and SPAD value could be estimated with $R^2$ values of 0.600, 0.657 and 0.747 respectively. The generated GIS map would describe variability of the potato growth in a whole field.

• Korean Journal of Health Education and Promotion
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• v.27 no.4
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• pp.7-16
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• 2010

Objectives: To obtain a more intensive understanding smoking behaviors of young adolescent in the contexts of schools which they attend, this study examined the effects of individual and school level factors divided into psychological and social factors respectively. Methods: Multilevel logistic regression analysis was used to test the effects of school smoking rates on 1 year smoking experience of individual pupils in a sample of 3,449 students from 100 middle schools in Korea. Results: The results of multilevel analysis revealed the importance of social factors in three environments. Especially the social factors in school level, which were sense of school membership and school smoking rate, explained the variances between groups dropping the school effect from 0.194 to 0.046. Conclusion: This study suggests that adolescents' smoking behaviors are related to the multi dimensional and multi level factors. To reduce young adults' smoking rate, school level intervention should not be ignored.

• Structural Engineering and Mechanics
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• v.77 no.2
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• pp.261-272
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• 2021

The energy-saving block and invisible multi-ribbed frame composite wall (EBIMFCW) is a new type of load-bearing wall. The study of this paper focus on it is hysteresis rule under horizontal cyclic loading. Firstly, based on the experimental data of the twelve specimens under horizontal cyclic loading, the influence of two important parameters of axial compression ratio and shear-span ratio on the restoring force model was analyzed. Secondly, a tetra-linear restoring force model considering four feature points and the degradation law of unloading stiffness was established by combining theoretical analysis and regression analysis of experimental data, and the theoretical formula of the peak load of the EBIMFCW was derived. Finally, the hysteretic path of the restoring force model was determined by analyzing the hysteresis characteristics of the typical hysteresis loop. The results show that the curves calculated by the tetra-linear restoring force model in this paper agree well with the experimental curves, especially the calculated values of the peak load of the wall are very close to the experimental values, which can provide a reference for the elastic-plastic analysis of the EBIMFCW.

• Journal of Korean Society for Quality Management
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• v.50 no.3
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• pp.407-424
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• 2022

Purpose: This study examines the relationship between the environment, society, and governance (ESG) perception of service providers and service quality by considering job satisfaction as a mediator in the Korean parcel delivery context. Methods: This study uses a multi-level analysis by incorporating organizational and individual levels of analysis. It employs a survey method for measuring the ESG perception of parcel delivery persons and service quality ratings from the Korean government. A hierarch regression analysis with 241 responses was used to test hypotheses. Results: The results of this study provide evidence that the ESG perception, particularly its social dimension, of parcel delivery persons is positively associated with service quality. This study also finds the positive effect of the ESG perception on job satisfaction. However, the mediating effect of job satisfaction between the ESG perception and service quality was not confirmed. Conclusion: This study presents significant implications for scholars and practitioners. Parcel delivery companies should implement relevant ESG activities and communicate them with their service persons to improve delivery service quality. The ESG perception of employees plays a critical role in the moment of truth in parcel service delivery to enhance customer satisfaction and service quality.

• Journal of the Chungcheong Mathematical Society
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• v.8 no.1
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• pp.1-10
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• 1995

For analyzing systems of multi-variate nonlinear equations, the linearized modelling techniques are elaborated. The technique applies Newton-Raphson iteration, partial differentiation and matrix operation providing solvable solutions to complicated problems. Practical application examples are given in; determining the zero point of functions, determining maximum (or minimum) point of functions, nonlinear regression analysis, and solving complex co-efficient polynomials. Merits and demerits of linearized modelling techniques are also discussed.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.133-136
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• 2005

Compressive strength of recycled aggregate concrete was tested by the core and by the non-destructive testing. A prediction model of compressive strength considering the replacement level of recycled aggregate was suggested by multi-regression analysis and was compared with test results. Also, Test results showed that the ratio of compressive strength by core and non-destructive testing to actual was somewhat affected by the replacement level of recycled aggregate.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.3
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• pp.35-47
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• 2023

Purpose : As the population aging deepens, the number of elderly people with arthritis is also continuously increasing. Accordingly, this study intended to identify the factors influencing the health-related quality of life (HINT-8) of the elderly with arthritis according to household type and provide baseline data for developing a measure to enhance the life quality of the elderly with arthritis. Methods : The factors influencing the health-related quality of life (HINT-8) of the elderly with arthritis were identified based on the raw data from the Korea national health and nutrition examination survey conducted in 2021. Data were analyzed with SPSS Statistics ver 25.0 for windows (IBM Corp), and the significance level (α) was set to .05. Statistical analysis was performed with t-test, ANOVA, multiple regression analysis, and post-hoc analysis with Duncan test. Results : The factors that influenced the health-related quality of life (HINT-8) of single-households were medical aid (β=-.17, p=.045), restriction of activity (β=-.17, p=.023), self-rated health status (β=.29, p<.001), and anxiety scale (β=-.36, p<.001). The factors that influenced the health-related quality of life (HINT-8) of multi-households were an age of 75 or over (β=-.14, p=.011), living in rural (β=-.14, p=.003), the outpatient department treatment experience (β=-.09, p=.047), self-rated health status (β=.26, p<.001), anxiety scale (β=-.29, p<.001), and stress (β=-.22, p<.001). Conclusion : Factors affecting the health-related quality of life (HINT-8) of the elderly with arthritis were found to be different between single-person households and multi-person household. Therefore, it is necessary to prepare measures to improve the quality of life of the elderly with arthritis by considering the factors influencing the health-related quality of life (HINT-8) of the elderly with arthritis according to the household type identified in this study.