• Physical Therapy Korea
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• v.20 no.4
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• pp.40-46
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• 2013

The purpose of this study was to determine which spatiotemporal gait parameters obtained during hemiplegic walking could be a predictive factor for the Timed Up and Go test (TUG). Two hundreds nine subjects who had suffered a stroke were recruited for this study. They were participated in two assessments; the TUG test and gait analysis. The relationship between the TUG test and spatiotemporal parameters was analyzed using Pearson's correlation coefficients. In addition, to predict the spatiotemporal gait parameters that correlated most with the TUG scores, we used multiple linear regression analyses (stepwise method). The results show that the normalized velocity was strongly correlated with the TUG performance (r=-.72, p<.001). Additionally, single support percentage (SSP), double support percentage (DSP), step time difference (STD), and step length difference (SLD) significantly were correlated with the TUG test. Normalized velocity, STD, DSP of affected side, and SSP of non-affected side explained 53%, 8%, 3%, 2%, of variance in the TUG test respectively. In conclusion, an increase in gait velocity and a decrease in STD would be effective indicators of improvement on the functional mobility in the stroke rehabilitation.

• International Journal of Highway Engineering
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• v.14 no.6
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• pp.139-148
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• 2012

PURPOSES : The accuracy of travel time information is a key measure of effectiveness and reliability of advanced traveler information systems. This study aims at investigating drivers' perception on the acceptable level of information accuracy and their corresponding valuations. METHODS : A questionnaire survey was executed for collecting driver perception data to capture the expectation level of travel time information provided and their willingness to pay for the information. A Tobit model was adopted for exploring the relationship among the acceptable level, driver socioeconomic characteristics and travel attributes. Since drivers' willingness to pay for accurate travel time information can be different according to their travel lengths, a piecewise linear regression model was developed to capture the sensitivity of values of travel time information to travel length. RESULTS : The analysis results suggest that trip purpose and travel time are two dominant factors to determine drivers' acceptable level of travel time information. For business and short trips, drivers want more accurate information than for non-business and long trips. Drivers' willingness to pay for travel time information also varies depending on their incomes, trip purposes and travel lengths. The results also show that drivers' valuation of travel time information provided is sensitive to their travel length. For longer trips, drivers are less sensitive to travel time information and then put less value on the information provided. CONCLUSIONS : Censored nonlinear regression models are developed to estimate drivers' acceptable accuracy for travel time information and their valuation using questionnaire survey data. The findings on drivers perception to the required accuracy of travel time information and their corresponding willingness to pay can be used in the design and deployment of advanced traveler information system to improve its effectiveness and usefulness through high compliance.

• Journal of Society of Preventive Korean Medicine
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• v.20 no.3
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• pp.67-74
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• 2016

Objectives : The purpose of this study was to analyze the relationship between the Cold-pattern and the quantitative index through the results of an anthropometric method and Bio Impedance Analysis (BIA) of the Haenyeo living in Jeju island. Furthermore, we will examine the effect of Cold-pattern on the quality of life. Methods : BIA indices were acquired directly from Inbody770 and questionnaires were collected by Gallup Korea professional surveyor through face to face interviews. Binary regression analysis and linear regression analysis were used to examine the association between collected data. Results : Total of 175 of people were participated in this study. First, we examined the difference of the indicators in the Cold-pattern group and the non-Cold pattern group by the average comparison of the anthropometry and BIA indices. Most of the non-Cold pattern group showed high quality of life, BIA and anthropometry. In the relationship between Cold-pattern and anthropometry and BIA indices, BMI and PA indices were found to affect the Cold-pattern on a group basis. As the BMI increased by $1kg/m^2$, probability of not being non-Cold pattern was 1.13 times. and as the PA increased by $1^{\circ}$, probability of not being non-Cold pattern was 2.4 times. In the case of EQ5D value, the quality of life of ${\beta}$ was increased by 0.08 in non-Cold pattern (p <.05), EQ5D VAS of ${\beta}$ was also increased by 10.05 (p <.05). Conclusions : This study showed that BMI and PA could be used as a clinical index to evaluate the Cold-pattern as a clinical indicator, and there is a difference in quality of life according to Cold-pattern.

• Journal of Integrative Natural Science
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• v.13 no.3
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• pp.105-113
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• 2020

As the COVID-19 outbreak has prolonged, social distancing movements are encouraged and non-face-to-face lifestyle trends are spreading. As a result, it is necessary for general restaurants and small marts to provide delivery services like large-scale distribution companies. Large distribution companies have also suffered significant economic losses from COVID-19 because epidemiological investigations were conducted after the distribution center was closed due to the outbreak of COVID-19 in several large domestic distribution companies. In this thesis, in order to examine whether COVID-19 actually affects distribution companies, we attempt to understand the relationship between the number of confirmed cases per month and the sales share and growth rate by categories of distribution companies.

• Earthquakes and Structures
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• v.16 no.3
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• pp.295-310
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• 2019

This study attempts to develop new simplified approximate formulas to predict the fundamental natural periods of vibration (T) for bearing wall systems engaged with special reinforced concrete shear walls (RCSW) under seismic loads. Commonly, seismic codes suggested empirical formulas established by regression analysis of measured T for buildings during earthquake motions. These formulas depend on structure type, building height, number, height and length of SW, and ratio of SW area to base area of structure. In this study, a parametric investigation is performed for T of 110 selected models of bearing RCSW systems with varying structural height, configuration of horizontal plans including building width, number and width of bays, presence of middle corridors and core SWs. For this purpose, a 3D non-linear response time history (TH) analysis is implemented using ETABS v16.2.1. New formulas to estimate T are anticipated and compared with those obtained from formulas of IBC 2012 and ASCE/SEI 7-10. Moreover, the study examines responses of an arbitrarily two selected test model of 60 m and 80 m in height with presence of SWs having middle corridors. It is observed that the performance of the tested buildings is different through arising of considerable errors when using codes' formulas for estimating T. Accordingly, using the present proposed formulas exhibits more reasonable and safer design compared to codes' formulas. The results showed that equitable enhancement is promising to improve T formulas approaching enhanced and accurate estimation of T with reliable analysis, design, and evaluation of bearing RCSW systems.

• Structural Engineering and Mechanics
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• v.82 no.1
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• pp.121-131
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• 2022

The main goal of this study is to prepare a program for analyzing High Strength Steel Fibrous Reinforced Concrete (HSSFRC) slabs and predict the response and strength of the slab instead of preparing a prototype and testing it in the laboratory. For this purpose, new equations are proposed to represent the material properties of High Strength Steel Fibrous Reinforced Concrete. The proposed equations obtained from performing regression analysis on many experimental results using statistical programs. The finite element method is adopted for non-linear analysis of the slabs. The eight-node "Serendipity element" (3 DoF) is chosen to represent the concrete. The layered approach is adopted for concrete elements and the steel reinforcement is represented by a smeared layer. The compression properties of the concrete are modeled by a work hardening plasticity approach and the yield condition is determined depending on the first two stress invariants. A tensile strength criterion is adopted in order to estimate the cracks propagation. many experimental results for testing slabs are compared with the numerical results of the present study and a good agreement is achieved regarding load-deflection curves and crack pattern. The response of the load deflection curve is slightly stiff at the beginning because the creep effect is not considered in this study and for assuming perfect bond between the steel reinforcement and the concrete, however, a great agreement is achieved between the ultimate load from the present study and experimental results. For the models of the tension stiffening and cracked shear modulus, the value of Bg and Bt (Where Bg and Bt are the curvature factor for the cracked shear modulus and tension stiffening models respectively) equal to 0.005 give good results compared with experimental result.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.1
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• pp.17-27
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• 2011

A selection experiment for reduced residual feed intake (RFI) in Yorkshire pigs consisted of a line selected for lower RFI (LRFI) and a random control line (CTRL). Longitudinal measurements of daily feed intake (DFI) and body weight (BW) from generation 5 of this experiment were used. The objectives of this study were to evaluate the use of random regression (RR) and nonlinear mixed models to predict DFI and BW for individual pigs, accounting for the substantial missing information that characterizes these data, and to evaluate the effect of selection for RFI on BW and DFI curves. Forty RR models with different-order polynomials of age as fixed and random effects, and with homogeneous or heterogeneous residual variance by month of age, were fitted for both DFI and BW. Based on predicted residual sum of squares (PRESS) and residual diagnostics, the quadratic polynomial RR model was identified to be best, but with heterogeneous residual variance for DFI and homogeneous residual variance for BW. Compared to the simple quadratic and linear regression models for individual pigs, these RR models decreased PRESS by 1% and 2% for DFI and by 42% and 36% for BW on boars and gilts, respectively. Given the same number of random effects as the polynomial RR models, i.e., two for BW and one for DFI, the non-linear Gompertz model predicted better than the polynomial RR models but not as good as higher order polynomial RR models. After five generations of selection for reduced RFI, the LRFI line had a lower population curve for DFI and BW than the CTRL line, especially towards the end of the growth period.

• Korean Journal of Construction Engineering and Management
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• v.5 no.6 s.22
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• pp.138-145
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• 2004

The construction duration for any building or facilities such as high school building influence the quality of the building as well as the total cost for them. Since there are no guidelines to estimate construction duration correctly, an employer(or owner) estimate it by their own experience or intuition. Therefore some conflicts related to construction duration happen between contract parties during construction. The purpose of this study is to suggest a predictive model which helps decision makers calculate exact net working days for high school building construction at the early stage of the construction project. To measure net working days for high school construction, 15 data were collected from actual spot in Incheon region. Multiple linear regression analysis was conducted to obtain the model which calculate construction duration for the substructure, the superstructure and the finishing works. total construction duration could be obtained by adding net working days to non working days which would be based on the meteorological statistics for Incheon region since 1974 to 2003.

• The Korean Journal of Applied Statistics
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• v.19 no.3
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• pp.407-419
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• 2006

In this paper, we analyze household overdue loans in Korea which has been causing serious social and economical problems. We consider customers of Bank A in Korea and focus on overdue cash services which have been snowballing in the past few years. From analysis of overdue loans, one can predict possible delays for current customers as well as build a credit evaluation and risk management system for future customers. As a statistical analytical tool, we propose a two-stage Generalized Linear regression Model (GLM) which assumes a logistic model for presence/non-presence of overdue and a gamma model for the amount of overdue in the case of overdue. We perform goodness of fit test for the two-stage model and select significant explanatory variables in each stage of the model. It turns out that age, the amount of credit loans from other financial companies, the amount of cash service from other companies, debit balance, the average amount of cash service, and net profit are important explanatory variables relevant to overdue credit card cash service in Korea.

• Journal of Preventive Medicine and Public Health
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• v.40 no.1
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• pp.51-58
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• 2007

Objectives : The objectives of this study were to estimate the continuity of care for all Koreans with diabetes and to identify factors affecting the continuity of care. Methods : We obtained National Health Insurance claims data for patients with diabetes who visited health-care providers during the year 2004. A total of 1,498,327 patients were included as study subjects. Most Frequent Provider Continuity (MFPC) and Modified, Modified Continuity Index (MMCI) were used as indexes of continuity of care. A multiple linear regression analysis was used to identify factors affecting continuity of care. Results : The average continuity of care in the entire population of 1,498,327 patients was $0.89{\pm}0.17$ as calculated by MFPC and $0.92{\pm}0.16$ by MMCI. In a multiple linear regression analysis, both MFPC and MMCI were lower for females than males, disabled than non-disabled, Medicaid beneficiaries than health insurance beneficiaries, patients with low monthly insurance contributions, patients in rural residential areas, and patients whose most frequently visited provider is the hospital. Conclusions : The continuity of care for patients with diabetes is high in Korea. However, women, the disabled and people of low socio-economic status have relatively low continuity of care. Therefore, our first priority is to promote a diabetes management program for these patients.