• Journal of Construction Engineering and Project Management
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• v.7 no.2
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• pp.11-18
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• 2017

The cycle time of construction equipment for earthwork operations has a significant impact on project productivity. Elements that directly impact a haul vehicle's cycle time must be identified in order to accurately quantify the haul cycle time and implement strategies to decrease it. The objective of this research is to scientifically identify and quantify variables that have a significant impact on the cycle time of a dump truck used for earthwork. Real-time location data collected by GPS devices deployed in an active earthwork moving construction site was analyzed using statistical regression. External data including environmental components and haul road conditions were also collected periodically throughout the study duration. Several statistical analyses including a variance analysis and regression analysis were completed on the dump truck location data. Collected data was categorized by stage of the dump truck cycle. Results indicate that a dump truck's enter idle time, exit idle time, moving speed and driver visibility can significantly impact the dump truck cycle time. The contribution of this research is the identification and analysis of statistically significant correlations of variables within the cycle time.

• Journal of Family Resource Management and Policy Review
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• v.17 no.4
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• pp.1-17
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• 2013

The purpose of this study was to explore the effects of socio-demographic variables on time management and to investigate the effects of time management on self-efficacy and academic achievement in college students. The data were collected from 382 college students through questionnaire surveys and analyzed using frequency, percentile, and regression analysis with the SPSS program. College students' time management behavior was influenced by the social status of their families and by their participation in time management education. There were differences in variables affecting time management according to its sub-areas (planning, regular habits, and goal-oriented behavior). Planning was influenced by the students' majors and by their participation in time management education. Regular habits were influenced by the students' genders and their families' social status. No variables affected goal-oriented behavior. Time management (especially planning and goal-oriented behavior) and gender had strong effects on self-efficacy, and male students showed more self-efficacious behavior than their female counterparts. Time management (especially planning and regular habits) and gender had strong effects on academic achievement, and female students received higher academic grades than their male counterparts. Based on these results, time management was confirmed as an influential element in self-efficacy and academic achievement. Planning and goal-oriented behavior particularly influenced self-efficacy, and planning and regular habits particularly influenced academic achievement.

• Korea Journal of Hospital Management
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• v.12 no.2
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• pp.69-92
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• 2007

This research has classified waiting times into the three different ones according to service offering process and investigated the antecedents and consequences of types of waiting times. A service provider's concern and customer involvement were modeled as antecedent variables and negative emotion and service value as dependent variables. The empirical results of the study are as follows. A service provider's concern had significant influences on all the three types of waiting times whereas customer involvement was found to affect preprocess-waiting and postprocess-waiting times. Preprocess-waiting time had a significant impact on both negative emotion and service value and inprocess-waiting time only affects negative emotion. However, postprocess-waiting time had influenced none of the variables. The findings illustrate an important role of concern and involvement regarding to a customer's perceived waiting time and relative importance of waiting types on negative emotion and service value. A summary of the results are reported and managerial implications are discussed.

• Proceedings of the Safety Management and Science Conference
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• 2012.04a
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• pp.117-137
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• 2012

In the ALC(Autoclaved lightweight concrete) manufacturing process, if the pre-cured semi-cake is removed after proper time is passed, it will be hard to retain the moisture and be easily cracked. Therefore, in this research, we took the research by multiple regression analysis to find relationship between variables for the prediction the hardness that is the control standard of the removal time. We study the relationship between Independent variables such as the V/T(Vibration Time), V/T movement, expansion height, curing time, placing temperature, Rising and C/S ratio and the Dependent variables, the hardness by multiple regression analysis. In this study, first, we calculated regression equation by the regression analysis, then we tried phased regression analysis, best subset regression analysis and residual analysis. At last, we could verify curing time, placing temperature, Rising and C/S ratio influence to the hardness by the estimated regression equation.

• Structural Engineering and Mechanics
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• v.38 no.2
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• pp.171-193
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• 2011

One of the possible alternatives of simulation-based time-dependent reliability assessment of pre-stressed biconcave and biconvex cable trusses, the Monte Carlo method, is applied in this paper. The influence of an excessive deflection of cable truss (caused by creep of cables and rheologic changes) on its time-dependent serviceability is investigated. Attention is given to the definition of the basic random variables and their statistical functions (basic, mutually dependent random variables such as the pre-stressing forces of the bottom and top cable, structural geometry, the Young's modulus of elasticity of the cables, and the independent variables, such as permanent load, wind, snow and thermal actions). Then, the determination of the response of the cable truss to the loading effects, and the definition of the limiting values considering serviceability of the structure are performed. The potential of the method, using direct Monte Carlo technique for simulation-based time-dependent reliability assessment as a powerful tool, is emphasized. Results obtained by the First order reliability method (FORM) are compared with those obtained by the Monte Carlo simulation technique.

• Journal of the Korean Home Economics Association
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• v.32 no.5
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• pp.55-66
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• 1994

The aim of this study is to propose the reasonable method of evaluation on the value of the life-time household work. for homemaker claim her share in the matrimonial property in relation to her life-time household work and to provide the basic data to measuring proper compensation for homemaker and calculating of the donation tax and inheritance tax amount. Tom compare the difference of the method of evaluation on the value of the life-time household work is evaluted by three methods: the model of the life-time household work which is reflected major variables in the FLC frame work marital stage, total marital period. The major findings are as follows: 1) Among the three evaluation me？ The method of Total marital period is evaluatied the lowest value of the life-time household work. 2) The evaluation method of marital stage is more resonable method than the method of total marital period habe a convenience of evaluation but it dos'nt reflected major variables which influence the value of life-time household work. 3) the most resonable method of evaluation on the value of the life-time household work is revealed the model of the life-time household work which is reflected major variables in the FLC frame work the age of first and last offspring marital period.

• Korean Journal of Human Ecology
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• v.20 no.2
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• pp.311-325
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• 2011

The purpose of this study was to analyze patterns of time usage of the retired elderly so as to improve their quality of life. The subjects of this study were 225 elderly people in Jeonnam Province. The statistics used for data analysis were frequency, percentage, mean, standard deviation, t-test, and multiple regression. The major findings were as follows : (1) The retired elderly spend more time in physiological activities and leisure, and there was no day difference in time use. (2) On weekdays, the variables affecting labor time were age, former job, health state, and education. On the weekends, education, health state, and former job had significant effects on the amount of time spent on labor. (3) The variables affecting participation and volunteer time were: monthly living expenses, age, spouse, former job, and house, on weekdays, and on the weekends, significant factors were spouse, age, and former job. (4) The variables affecting leisure time were education, age, monthly living expenses, religion, and economic state, on the weekdays, and on weekends, the significant factors were education, economic state, house, religion, and former job.

• Physical Therapy Rehabilitation Science
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• v.11 no.2
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• pp.215-223
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• 2022

Objective: This study was to resolve the limitations of the experimental environment and to solve the shortcomings of the method of measuring human gait characteristics using optical measuring instruments. Design: A cross-sectional study. Methods: Fifteen healthy adults without a history of orthopedic surgery on the lower extremities for the past 6 months were participated. They were analyzed gait variables using the smart guide and the 3D image analysis at the same time, and their results were compared. Visual-3D was used to calculate the analysis variables. Results: The reliability and validity of the data according to the two measuring instruments were found to be very high; gait speed(0.85), cycle time(0.99), stride time of both feet(0.98, 0.97) stride legnth of both feet(0.86, 0.88) stride per minute of both feet(0.99, 0.96), foot speed of both feet(0.90, 0.91), step time of both feet(0.77, 0.71), step per minute(0.72, 0.74), stance time of both feet(0.96, 0.97), swing time of both feet(0.93, 0.79), double step time(0.81), initial double step time(0.84) and terminal step time(0.76). Conclusions: In the case of the smart insole, which measures human gait variables using the pressure sensor and inertial sensor inserted in the insole, the reliability and validity of the measured data were found to be very high. It can be used as a device to replace 3D image analysis when measuring pathological gait.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.7 no.2
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• pp.101-111
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• 2012

In the ALC(Autoclaved lightweight concrete) manufacturing process, if the pre-cured semi-cake is removed after proper time is passed, it will be hard to retain the moisture and be easily cracked. Therefore, in this research, we took the research by multiple regression analysis to find relationship between variables for the prediction the hardness that is the control standard of the removal time. We study the relationship between Independent variables such as the V/T(Vibration Time), V/T movement, expansion height, curing time, placing temperature, Rising and C/S ratio and the Dependent variables, the hardness by multiple regression analysis. In this study, first, we calculated regression equation by the regression analysis, then we tried phased regression analysis, best subset regression analysis and residual analysis. At last, we could verify curing time, placing temperature, Rising and C/S ratio influence to the hardness by the estimated regression equation.

• Communications for Statistical Applications and Methods
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• v.19 no.4
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• pp.527-536
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• 2012

In this paper we analyze the effect of circular variables such as wind direction, time and month on the ozone level. In particular, we examined the effect of wind direction by exploratory data analysis methods and provide the correlation and regression analyzes in the cases including all circular explanatory variables. In the analysis, we convert time and month variables to circular variables and analyze the effect of these variables on regression analysis; in addition, we also consider circular-circular regression. We used weather condition and air pollution data collected from Dongdaemoon district of Seoul in 2007.