• Title/Summary/Keyword: Regressions Model

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Genetic Parameters for Litter Size in Pigs Using a Random Regression Model

  • Lukovic, Z.;Uremovic, M.;Konjacic, M.;Uremovic, Z.;Vincek, D.
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.2
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    • pp.160-165
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    • 2007
  • Dispersion parameters for the number of piglets born alive were estimated using a repeatability and random regression model. Six sow breeds/lines were included in the analysis: Swedish Landrace, Large White and both crossbred lines between them, German Landrace and their cross with Large White. Fixed part of the model included sow genotype, mating season as month-year interaction, parity and weaning to conception interval as class effects. The age at farrowing was modelled as a quadratic regression nested within parity. The previous lactation length was fitted as a linear regression. Random regressions for parity on Legendre polynomials were included for direct additive genetic, permanent environmental, and common litter environmental effects. Orthogonal Legendre polynomials from the linear to the cubic power were fitted. In the repeatability model estimate of heritability was 0.07, permanent environmental effect as ratio was 0.04, and common litter environmental effect as ratio was 0.01. Estimates of genetic parameters with the random regression model were generally higher than in the repeatability model, except for the common litter environmental effect. Estimates of heritability ranged from 0.06 to 0.10. Permanent environmental effect as a ratio increased along a trajectory from 0.03 to 0.11. Magnitudes of common litter effect were small (around 0.01). The eigenvalues of covariance functions showed that between 7 and 8 % of genetic variability was explained by individual genetic curves of sows. This proportion was mainly covered by linear and quadratic coefficients. Results suggest that the random regression model could be used for genetic analysis of litter size.

Effects of Goal Contents on Failure Tolerance: In Focus of Engineering Undergraduates, Graduates, and Experts (목표내용이 공학도의 실패내성에 미치는 영향: 대학생, 대학원생, 전문가를 중심으로)

  • Park, Soowon;Shin, Jongho;Lee, Seon-Young;Lee, ByungYoon;Rhee, Shin Hyung
    • Journal of Engineering Education Research
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    • v.18 no.5
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    • pp.11-21
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    • 2015
  • The purpose of this study was to examine the effects of goal contents on failure tolerance in engineers (i.e., students and experts in engineering). Based on the goal contents theory, which is a sub-theory of self-determination theory, three intrinsic goals (i.e., self-growth, help, social concern) and two extrinsic goals (i.e., money, fame) were under investigation. A total of 398 participants (118 undergraduate students, 181 graduate students, 99 experts) answered survey questions. In the hierarchical multiple regressions, self-growth goal was entered as the first model, then, to the second model, the other four goals were added. The results showed that social concern goal significantly predicted failure tolerance among all engineer groups. Self-growth goal was closely associated with failure tolerance in undergraduate students and graduate students. Help goal was significant only among graduate students. These results suggest that pursuing intrinsic goals, especially, social concern goal is important to increase failure tolerance. Establishing infrastructure and educational climate for pursuing social concern goal can facilitate the development of personal expertise in engineers as well as the improvement of society.

Strength prediction of rotary brace damper using MLR and MARS

  • Mansouri, I.;Safa, M.;Ibrahim, Z.;Kisi, O.;Tahir, M.M.;Baharom, S.;Azimi, M.
    • Structural Engineering and Mechanics
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    • v.60 no.3
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    • pp.471-488
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    • 2016
  • This study predicts the strength of rotary brace damper by analyzing a new set of probabilistic models using the usual method of multiple linear regressions (MLR) and advanced machine-learning methods of multivariate adaptive regression splines (MARS), Rotary brace damper can be easily assembled with high energy-dissipation capability. To investigate the behavior of this damper in structures, a steel frame is modeled with this device subjected to monotonic and cyclic loading. Several response parameters are considered, and the performance of damper in reducing each response is evaluated. MLR and MARS methods were used to predict the strength of this damper. Displacement was determined to be the most effective parameter of damper strength, whereas the thickness did not exhibit any effect. Adding thickness parameter as inputs to MARS and MLR models did not increase the accuracies of the models in predicting the strength of this damper. The MARS model with a root mean square error (RMSE) of 0.127 and mean absolute error (MAE) of 0.090 performed better than the MLR model with an RMSE of 0.221 and MAE of 0.181.

An Exploratory study of compliance with dietary recommendations among college students majoring in health-related disciplines: application of the transtheoretical model

  • McArthur, Laura H.;Pawlak, Roman
    • Nutrition Research and Practice
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    • v.5 no.6
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    • pp.578-584
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    • 2011
  • Compliance with food group and nutrient recommendations, and self-efficacy, stage of change, perceived barriers and benefits for healthy eating were assessed among a convenience sample of college students majoring in health-related disciplines. Dietary and psychosocial data were collected using three-day food records and scales, respectively. Means (SD), frequencies, and percents were calculated on all data, and logistic regressions were used to determine whether any of the psychosocial correlates predicted the stage of change for healthy eating. Noncompliance with food group recommendations ranged from 53% for the meat/meat alternates group to 93% for the vegetables/juice group, whereas noncompliance with nutrient recommendations ranged from 26% for cholesterol to 99% for potassium. A majority of students (57%) self-classified in the preaction and 40% in the action stages of change for eating healthy. The students' self-efficacy to eat healthy was highest in positive/social situations and lowest when experiencing emotional upset. The most important perceived barrier to healthy eating was that friends/roommates do not like to eat healthy foods, and the most important perceived benefit was that eating healthy foods provides the body with adequate nutrients. The difficult/inconvenient self-efficacy subscale predicted the stage of change for healthy eating. These students would benefit from interactive learning opportunities that teach how to purchase and prepare more whole grain foods, fruits, and vegetables, enhance their self-efficacy for making healthy food choices when experiencing negative emotions, and overcome perceived barriers to healthy eating.

Temperature Effect on Impedance-based Damage Monitoring of Steel-Bolt Connection using Wireless Impedance Sensor Node (무선 임피던스 센서노드를 이용한 강-볼트 접합부의 임피던스기반 손상모니터링에 미치는 온도 영향)

  • Hong, Dong-Soo;Kim, Jeong-Tae
    • Journal of Ocean Engineering and Technology
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    • v.26 no.1
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    • pp.27-33
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    • 2012
  • This paper presents the effect of temperature on the impedance-based damage monitoring of steel-bolt connections using wireless impedance sensor nodes. In order to achieve the objective, the following approaches are implemented. First, a temperature-compensated damage monitoring scheme that includes a temperature compensation model and damage detection method is described. The temperature compensation model is designed by analyzing the linear regressions between the temperatures and impedance signatures. The correlation coefficient of the impedance signatures is selected as the damage index to monitor the damage occurrence in the target structures. Second, a wireless impedance sensor node is described for the design of the hardware components and embedded software. Finally, the performance of the temperature-compensated impedance-based damage monitoring scheme is evaluated for detecting a loose bolt in the steel-bolt connections on a lab-scale steel girder under various temperatures.

Assessment Model for Industrial Accidents Prevention Policy (산업재해 예방정책에 대한 평가모형)

  • Kim, Youngsun;Jo, Jinnam;Baik, Jaiwook
    • Journal of Applied Reliability
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    • v.17 no.1
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    • pp.38-49
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    • 2017
  • Purpose: The purpose of this study is to introduce the assessment model for industrial accidents prevention policy. Methods: 10 years of industrial accidents data are explored through EDA approach. Case control study is tried in order to assess the effectiveness of the measures taken by Korea Safety and Health Agency, Civilian, and 'Ministry of Employment and Labor'. Propensity score matching is used to match the characteristics of the two groups compared, and then case control study is again conducted. Next, logistic and Poisson regressions are used to assess the risk factors. Results: According to case control study involvement of 'Korea Safety and Health Agency' and 'Ministry of Employment and Labor' were not effective, but Civilian was. Propensity score matching leads to the same conclusion. Poisson regression reveals the impact of the risk factors on the industrial accidents. Industrial accidents occur more often as the number of employees grows. Mining, farming, fishing, 'transportation storage and telecommunication' and forestry have a higher level of industrial accidents but service industry has a lower level. It is odd that more involvement of Korea Safety and Health Agency, Civilian, and Ministry of Employment and Labor means more industrial accidents. Conclusion: 'Korea Safety and Health Agency', Civilian, and 'Ministry of Employment and Labor' seem to visit those industries with more industrial accidents.

Reexamination of Estimating Beta Coecient as a Risk Measure in CAPM

  • Phuoc, Le Tan;Kim, Kee S.;Su, Yingcai
    • The Journal of Asian Finance, Economics and Business
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    • v.5 no.1
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    • pp.11-16
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    • 2018
  • This research examines the alternative ways of estimating the coefficient of non-diversifiable risk, namely beta coefficient, in Capital Asset Pricing Model (CAPM) introduced by Sharpe (1964) that is an essential element of assessing the value of diverse assets. The non-parametric methods used in this research are the robust Least Trimmed Square (LTS) and Maximum likelihood type of M-estimator (MM-estimator). The Jackknife, the resampling technique, is also employed to validate the results. According to finance literature and common practices, these coecients have often been estimated using Ordinary Least Square (LS) regression method and monthly return data set. The empirical results of this research pointed out that the robust Least Trimmed Square (LTS) and Maximum likelihood type of M-estimator (MM-estimator) performed much better than Ordinary Least Square (LS) in terms of eciency for large-cap stocks trading actively in the United States markets. Interestingly, the empirical results also showed that daily return data would give more accurate estimation than monthly return data in both Ordinary Least Square (LS) and robust Least Trimmed Square (LTS) and Maximum likelihood type of M-estimator (MM-estimator) regressions.

Gender Differences in Determinants of Customer Satisfaction in Beauty and Cosmetic E-commerce

  • NGUYEN, Thuan Thi Nhu
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.10
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    • pp.811-822
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    • 2020
  • This study investigates the gender differences in determinants of customers' satisfaction when purchasing online beauty and cosmetics products in Vietnamese market. To do so, we construct a data set via online survey of 419 Vietnamese customers including both males and females, and examine such sample using t-tests and multiple regressions. Our regression model is constructed based on our five-construct model including online shopping experience, customer service, external incentives, security and privacy, and personal characteristics. The t-tests results reveal that the mean difference of customer satisfaction (negative coefficient) between the two groups of customers (females and males) is statistically significant. This suggests that the purchasing satisfaction of male customers is significantly higher than that of their female counterparts. Similarly, we also find that male customers are more satisfied with their online shopping experience, customer service and external incentives offered by the online sellers than female peers. Furthermore, regression results for full sample show that, on average, the online shopping experience, customer service and external incentives are significantly and positively related to customer satisfaction. Yet, such positive effect of customer service on customer satisfaction is more likely for males while females' satisfaction is more positively influenced by security and privacy.

Information Technology Usage to Improve the Perceived Quality of Healthcare Service

  • Vilivong, Chindavanh;Cho, Namjae
    • Journal of Information Technology Applications and Management
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    • v.21 no.2
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    • pp.31-48
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    • 2014
  • The concept of Health Related Quality of Life and its determinants have evolved since the 1980s. Although many researchers have published articles of technology usage in hospitals and the installation of technology based healthcare system, the research about applying the information technology to improve the patients' perceived quality of healthcare services is still limited. In general, services are deeds, processes and performances that are essentially concerns of the consumer. The healthcare service quality depends on tangible factors, such as equipments, facilities, and the quality of hospital staff and also the intangible ones. The main purpose of this work is to establish new model and find out the contribution of information technology to enhance the patients' perceived quality of healthcare service. We attempted to examine the main information technology related factors in 3 aspects, namely quality of information, the technology accessibility and the community that can improve patients' perceived quality of healthcare services. Offline and online questionnaires were used to measure the patients' perceived quality and were distributed to 384 people in 2 countries, Laos and South Korea. A principle component analysis and multiple regressions were used to verify our model. Results show that the use of information technology has partial positive effect on patient-physician interaction in both countries. However, patient knowledge and patient autonomy which are the 2 dimensions of patient-physician interaction has significant positive effect on patients' perceived quality of healthcare service.

Risk Assesment for Large-scale Slopes Using Multiple Regression Analysis (다중회귀분석을 이용한 대규모 비탈면의 위험도 평가)

  • Lee, Jong-Gun;Chang, Buhm-Soo;Kim, Yong-Soo;Suk, Jae-Wook;Moon, Joon-Shik
    • Journal of the Korean Geotechnical Society
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    • v.29 no.11
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    • pp.99-106
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    • 2013
  • In this study, the correlation of evaluation items and safety rating for 104 of large-scale slopes along the general national road was analyzed. And, we proposed the regression model to predict the safety rating using the multiple regressions analysis. As the result, it is shown that the evaluation items of slope angle, rainfall and groundwater have a low correlation with safety rating. Also, the regression model suggested by multiple regression analysis shows high predictive value, and it would be possible to apply if the evaluation items of excavation condition and groundwater (rainfall) are not clear.