• Asian-Australasian Journal of Animal Sciences
• /
• v.24 no.2
• /
• pp.162-172
• /
• 2011

In this paper, simulation was used to determine accuracies of genomic breeding values for polygenic traits associated with many thousands of markers obtained from high density genome scans. The statistical approach was based upon stochastically simulating a pedigree with a specified base population and a specified set of population parameters including the effective and noneffective marker distances and generation time. For this population, marker and quantitative trait locus (QTL) genotypes were generated using either a single linkage group or multiple linkage group model. Single nucleotide polymorphism (SNP) was simulated for an entire bovine genome (except for the sex chromosome, n = 29) including linkage and recombination. Individuals drawn from the simulated population with specified marker and QTL genotypes were randomly mated to establish appropriate levels of linkage disequilibrium for ten generations. Phenotype and genomic SNP data sets were obtained from individuals starting after two generations. Genetic prediction was accomplished by statistically modeling the genomic relationship matrix and standard BLUP methods. The effect of the number of linkage groups was also investigated to determine its influence on the accuracy of breeding values for genomic selection. When using high density scan data (0.08 cM marker distance), accuracies of breeding values on juveniles were obtained of 0.60 and 0.82, for a low heritable trait (0.10) and high heritable trait (0.50), respectively, in the single linkage group model. Estimates of 0.38 and 0.60 were obtained for the same cases in the multiple linkage group models. Unexpectedly, use of BLUP regression methods across many chromosomes was found to give rise to reduced accuracy in breeding value determination. The reasons for this remain a target for further research, but the role of Mendelian sampling may play a fundamental role in producing this effect.

• Asian-Australasian Journal of Animal Sciences
• /
• v.31 no.10
• /
• pp.1542-1549
• /
• 2018

Objective: Because lactation periods in dairy cows lengthen with increasing total milk production, it is important to predict individual productivities after 305 days in milk (DIM) to determine the optimal lactation period. We therefore examined whether the random regression (RR) coefficient from 306 to 450 DIM (M2) can be predicted from those during the first 305 DIM (M1) by using a RR model. Methods: We analyzed test-day milk records from 85,690 Holstein cows in their first lactations and 131,727 cows in their later (second to fifth) lactations. Data in M1 and M2 were analyzed separately by using different single-trait RR animal models. We then performed a multiple regression analysis of the RR coefficients of M2 on those of M1 during the first and later lactations. Results: The first-order Legendre polynomials were practical covariates of RR for the milk yields of M2. All RR coefficients for the additive genetic (AG) effect and the intercept for the permanent environmental (PE) effect of M2 had moderate to strong correlations with the intercept for the AG effect of M1. The coefficients of determination for multiple regression of the combined intercepts for the AG and PE effects of M2 on the coefficients for the AG effect of M1 were moderate to high. The daily milk yields of M2 predicted by using the RR coefficients for the AG effect of M1 were highly correlated with those obtained by using the coefficients of M2. Conclusion: Milk production after 305 DIM can be predicted by using the RR coefficient estimates of the AG effect during the first 305 DIM.

• Tuberculosis and Respiratory Diseases
• /
• v.81 no.2
• /
• pp.116-122
• /
• 2018

Background: Chronic obstructive pulmonary disease (COPD) is a serious chronic condition with a global impact. Symptoms of COPD include progressive dyspnea, breathlessness, cough, and sputum production, which have a considerable impact on the lives of patients. In addition to the human cost of living with COPD and the resulting death, COPD entails a huge economic burden on the Chinese population, with patients spending up to one-third of the average family income on COPD management in some regions is clinically beneficial to adopt preventable measures via prudent COPD care utilization, monetary costs, and hospitalizations. Methods: Toward this end, this study compared the relative effectiveness of six indices in predicting patient healthcare utilization, cost of care, and patient health outcome. The six assessment systems evaluated included the three multidimensional Body mass index, Obstruction, Dyspnea, Exercise capacity index, Dyspnea, Obstruction, Smoking, Exacerbation (DOSE) index, and COPD Assessment Test index, or the unidimensional measures that best predict the future of patient healthcare utilization, cost of care, and patient health outcome among Chinese COPD patients. Results: Multiple linear regression models were created for each healthcare utilization, cost, and outcome including a single COPD index and the same group of demographic variables for each of the outcomes. Conclusion: We conclude that the DOSE index facilitates the prediction of patient healthcare utilization, disease expenditure, and negative clinical outcomes. Our study indicates that the DOSE index has a potential role beyond clinical predictions.

• The Journal of Korean Society for School & Community Health Education
• /
• v.19 no.3
• /
• pp.109-121
• /
• 2018

Background & objectives: Life style modification reduces the health risks of young people and improves their health status. Physical activity is known the effective factor to reduce health risks and health problems. This study performed to analyze health promotion behaviors related to physical activity among first-year students of university. Methods: To examine the association with physical activity and health promotion practices, health survey was conducted with 3,806 students who were first-year students in a university by self-reported questionnaire from February 26 to March 10, 2015. Multiple logistic regression analysis was performed to identify the difference of health promotion behaviors by physical activities. Results: 51.4% of the first-year student was regular exercisers who had practiced on regular walking exercise or regular strength exercise or regular aerobic exercise for a week. 87.8% of students exercised one or more times within the last one week. On the other hand, 12.2% of them did not exercise. In multiple logistic regression models, it remained significantly the difference of regular exercise by gender, subjective health status, sleeping time per one day, BMI, drinking behavior, and eating habit (p<0.05, p<0.01, p<0.001). Also it remained significantly the difference by physical activity type, such as walking, strengthen, and aerobic exercise (p<0.05, p<0.01, p<0.001). Conclusion: To help the achievement of academic goal, it should build physical activity policies and comprehensive health promotion programs to reduce health risk factors of university students. Comprehensive university health services and customized program for university students could help to make the best of their health. In future, to enhance physical activity practice, it needs to develop various tailed messages and smart healthcare service using health information technology (IT) on campus.

• Journal of Environmental Science International
• /
• v.17 no.6
• /
• pp.601-609
• /
• 2008

In this study for the development of area due to the increasing of industry, population and spreading of urbanization is rapidly increasing but about seventy percent of our nation's areas consists of the mountainous districts. In such case, when those areas have the heavy rains break, they are washed away by a fast-flowing stream of a valley and overflowed. Thus it could result on human life and property damage and also the widespread of flood damage in the downstream area. To decrease those damage, the construction of flood control reservoir is necessary. This research was aim to construct the flood runoff models of a mountainous small district and to determine the probability rainfall by analyzing precipitation. The study also examined the effects of location and size of flood control reservoir on flood reduction. The result showed that the construction of detention basin was an effective way to ensure the safety of flood control and multiple detention basin had superior result for reducing amount of runoff in the down stream area than the single detention basin.

• Journal of Korean Academy of Nursing
• /
• v.48 no.4
• /
• pp.475-484
• /
• 2018

Purpose: To examine the prevalence of depressive symptoms and differentiate factors associated with them in urban and rural areas by applying the Ecological Models of Health Behavior. Methods: We employed a cross-sectional design and convenience sample of 460 female adolescents. The instruments included the Adolescent Mental-Health Problem-Behavior Questionnaire (AMPQ-II) and the Beck Depression Inventory (BDI). Results: Depressive symptoms were confirmed in 15.7% of urban adolescents and 22.9% of rural adolescents (p<.05). In the urban group, perception of health and stress associated with school performance were significantly associated with depressive symptoms. In the rural group, academic/internet related problems and rule violations were significantly associated with depressive symptoms (p<.05). General life happiness, worry/anxiety, and mood/suicidal ideation were common factors in both urban and rural areas (p<.05). Conclusion: Multiple factors were associated with depressive symptoms, and those significant factors differed between urban and rural female youths. Accordingly, tailored approaches are required considering urban and rural differences. The approaches should include intrapersonal, interpersonal, and organizational levels of interventions.

• Journal of Ship and Ocean Technology
• /
• v.3 no.1
• /
• pp.27-41
• /
• 1999

The objective of the paper is to study the impact of changing the traditional hull design of bulk carriers by providing them with a double hull while keeping the same deadweight. It is demonstrated that by introducing the double hull the structural reliability is increased throughout the entire life and also the extend of the needed repair is reduced. The results are obtained with recently developed mathematical tools for the reliability assessment of ship hulls subjected to the existence of multiple cracks both in the stiffeners and in the plating and it models the crack growth process. The effect of corrosion is represented as time dependent. The long-term stress range acting on the elements is defined as a function of the local transverse pressure of the internal cargo and outside sea water combined with the stresses resulting from the longitudinal bending of the hull, which is a combined with the stresses resulting from the longitudinal bending of the hull, which is a combineation of horizontal and vertical bending moments. The effect of maintenance actions is modelled as a stochastic process. The results show that a different design of the midship section improves the structural safety and also the economy with respect to structural repair of bulk carriers.

• ETRI Journal
• /
• v.45 no.5
• /
• pp.836-846
• /
• 2023

Mobile robots are used in modern life; however, object recognition is still insufficient to realize robot navigation in crowded environments. Mobile robots must rapidly and accurately recognize the movements and shapes of pedestrians to navigate safely in pedestrian-rich spaces. This study proposes real-time, accurate, three-dimensional (3D) multi-pedestrian detection and tracking using a 3D light detection and ranging (LiDAR) point cloud in crowded environments. The pedestrian detection quickly segments a sparse 3D point cloud into individual pedestrians using a lightweight convolutional autoencoder and connected-component algorithm. The multi-pedestrian tracking identifies the same pedestrians considering motion and appearance cues in continuing frames. In addition, it estimates pedestrians' dynamic movements with various patterns by adaptively mixing heterogeneous motion models. We evaluate the computational speed and accuracy of each module using the KITTI dataset. We demonstrate that our integrated system, which rapidly and accurately recognizes pedestrian movement and appearance using a sparse 3D LiDAR, is applicable for robot navigation in crowded spaces.

• Korean Journal of Occupational Health Nursing
• /
• v.33 no.1
• /
• pp.1-11
• /
• 2024

Purpose: This study aimed to analyze the factors influencing the well-being of middle-aged non-shift female workers using health-determinant models. Methods: This study analyzed data from the fifth Korean Working Conditions Survey (KWCS), involving 5,449 participants. A hierarchical multiple regression analysis was employed to examine the relationships between various factors and well-being. Results: The analysis identified key factors affecting well-being in middle-aged female non-shift workers, including supervisor support, presenteeism, satisfaction with the working environment, autonomy in working hours, support from coworkers, workplace discrimination, occupation, work-life balance, sleep problems, workplace size, weekly work hours, and sickness absence. This study confirms that the well-being of middle-aged non-shift female workers is influenced by factors at the individual, social, and community levels as well as by conditions related to love. Conclusion: To enhance the well-being of middle-aged female non-shift workers, it is essential to reinforce positive factors such as support from coworkers and superiors. Additionally, addressing and mitigating negatively influencing factors such as workplace discrimination and sleep problems is crucial in promoting well-being. By implementing measures to improve these aspects, organizations and policymakers can contribute to a healthier and more supportive work environment for middle-aged, non-shift female workers.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.16 no.9
• /
• pp.1605-1614
• /
• 1992

The effects of % overload (% O.L), baseline stress intensity factor range (.DELTA. $K_{b}$) and dimension-less crack depth (a/W) are examined for the retardation behaviors after a single overload and high-low block loads in 7075-T73 aluminum alloy. And wheeler model, which is one of the fatigue life prediction models, is modified to predict retardation life using these test results. The retardation cycles( $N_{d}$) increased with a decrease in a/W and an increase in % O.L. and (.DELTA. $K_{b}$) These effects are more severe after high-low block loads than single overload. In the case of single overload, the main mechanisms of the retardation are the crack closure and the relaxation of K due to crack branching. But in the case of high-low block loads, that of the main mechanism is the crack closure caused by the accumulated compressive residual stree at the crack tip, which is related with the contact of fracture surfaces. Test results were multiple regression analyzed and got regressed shaping correction factors, (n)$_{REG}$, as function of %O.L., a/W and (.DELTA. $K_{b}$) Wheeler model is modified by using these (n)$_{REG}$. The number of delay cycles calculated by modified Wheeler model were in good agreement with the test results of this study.y.udy.y.y.y.