• Asian-Australasian Journal of Animal Sciences
• /
• v.23 no.3
• /
• pp.302-307
• /
• 2010

The present study aimed to investigate the effects of maternal factors on body weight at hatching (day-old) and at six weeks of age in a commercial broiler line. A total of 6,765 records on body weight at day-old (BWTDO) and 115,421 records on body weight at six weeks of age (BWT6W), originated from a commercial broiler line during 14 generations, were used to estimate genetic parameters related to the effects of maternal traits on body weight of chicks immediately after hatch or six weeks thereafter. The data were analyzed using restricted maximum likelihood procedure (REML) and an animal model with DFREML software. Direct heritability ($h^{2}{_a}$), maternal heritability ($h^{2}{_m}$), and maternal environmental variance as the proportions of phenotypic variance ($c^{2}$) for body weight at day-old were estimated to be 0.050, 0.351, and 0.173, respectively. The respective estimated values for body weight at six weeks of age were 0.340, 0.022, and 0.030. The correlation coefficient between direct and maternal genetic effects for six-week-old body weight was found to be -0.335. Covariance components and genetic correlations were estimated using a bivariate analysis based on the best model determined by a univariate analysis. Between weights at hatching and at six week-old, the values of -0.07, 0.53 and 0.47 were found for the direct additive genetic variance, maternal additive genetic variance and permanent maternal environmental variance, respectively. The estimated correlation between direct additive genetic effect influencing weight at hatch and direct additive maternal effect affecting weight at six weeks of age was -0.21, whereas the correlation value of 0.15 was estimated between direct additive maternal effect influencing weight at hatch and direct additive genetic effect affecting weight at six-week-old. From the present findings, it can be concluded that the maternal additive genetic effect observed for weight at six weeks of age might be a factor transferred from genes influencing weight at hatch to weight at six-week-old.

• Journal of the Korean Statistical Society
• /
• v.25 no.3
• /
• pp.359-368
• /
• 1996

The maximum likelihood estimation is discussed for the NLAR model with Laplacian marginals. Since the explicit form of the estimates cannot be obtained due to the complicated nature of the likelihood function we utilize the automatic computer optimization subroutine using a direct search complex algorithm. The conditional least square estimates are used as initial estimates in maximum likelihood procedures. The results of a simulation study for the maximum likelihood estimates of the NLAR(1) and the NLAR(2) models are presented.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 1996.04b
• /
• pp.94-98
• /
• 1996

The static characteristics of air-lubricated slider bearing were performed using direct numerical method. The equations of motion of slider bearing are solved simultaneously with the Reynolds equation for three degrees of freedom. The molecular rarefaction effect is considered. The models implemented include the first-order slip, the second-order slip, and the Boltzmann equation model derived by Fukui and Kaneko(FK model)

• Korean Journal of Geomatics
• /
• v.4 no.1
• /
• pp.31-37
• /
• 2004

The aim of this research is comparing the existing approximation models (e.g. Affine Transformation and Direct Linear Transformation) with Rational Function Model as a substitute of rigorous sensor model of linear array scanner, especially push-broom sensor. To do so, this research investigates the mathematical model of each approximation method. This is followed by the assessments of accuracy of transformation from object space to image space by using simulated data generated by collinearity equations which incorporate or depict the physical aspects of linear array sensor.

• Journal of Mechanical Science and Technology
• /
• v.18 no.5
• /
• pp.865-876
• /
• 2004

A new concept of reduced quasi-dimensional combustion model for a direct injection diesel engine is developed based on the previously developed quasi-dimensional multi-zone model to improve the computational efficiency. In the reduced model, spray penetration and air entrainment are calculated for a number of zones within the spray while three zones with aggregated spray zone concept are used for the calculation of spray combustion and emission formation processes. It is also assumed that liquid phase fuel appears only near the nozzle exit during the breakup period and that spray vaporization is immediate in order to reduce the computational time. Validation of the reduced model with experimental data demonstrated that the new model can predict engine performance and NO and soot emissions reasonably well compared to the original model. With the new concept of reduced model, computational efficiency is significantly improved as much as 200 times compared to the original model.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.16 no.12
• /
• pp.2708-2715
• /
• 2012

This paper proposes a new sensorless speed control scheme of induction motor using Model Reference Adaptive Control and Direct Torque Control System. The Model Reference Adaptive Control System is based on the comparison between the outputs of Reference Model and Adjustable Model. The error between the estimated quantities obtained by the two models is used to drive a suitable adaptation mechanism which generates the estimated rotor speed for the Adjustable Model. And the Direct Torque Control scheme controls torque and flux by restricting the flux and torque errors within respective hysteresis bands, and motor torque and flux are controlled by the stator voltage space vector using optimum inverter switching table. The simulation results of proposed method indicate good speed responses from the low speed range to the high, and also show favorable characteristics of load operation.

• Journal of Korean Academy of Nursing
• /
• v.47 no.2
• /
• pp.211-221
• /
• 2017

Purpose: This study was done to develop and test a structural model on smoking cessation intention in technical high school men. The conceptual model was based on the theory of reasoned action and health promotion model. Methods: From May 29 to April 13, 2015, 413 technical high school students who smoked completed a structured questionnaire. Data were analyzed to calculate the direct and indirect effects of factors affecting smoking cessation intention. The SPSS WIN 20.0 and AMOS 21.0 programs were used. Results: The hypothetical model was a good fit for the data. The model fit indices were $x^2/df=2.36$, GFI=.95, AGFI=.92, NFI=0.97, and RMSEA=.05. Self-esteem had direct and indirect effects on smoking cessation intention. Attitude, subjective norm, and self-efficacy had direct effects on smoking cessation intention. Smoking knowledge and environmental factor had indirect effects on smoking cessation intention. This model explained 87.0% of the variance in smoking cessation intention. Conclusion: These results indicate that technical high school students' intention to stop smoking can be improved through an increase in self-esteem, negative environmental factors, attitude toward smoking cessation, subjective norm about smoking cessation, and self-efficacy for smoking cessation.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.11 no.3 s.25
• /
• pp.15-24
• /
• 1987

The purpose of this study was to investigate the relationships among fasion leadership, Social character, clothing conformity and fashion information source. For this purpose, a causal model was to be constructed and empirically tested. Fashion leadership is divided into fashion opinion leadership and fashion innovativeness and is appropriated to the model. The following conclusions were derived from the data analysis. 1. Social character has direct effects on clothing conformity, but indirect effects on fashion information source. 2. Significant interaction between clothing conformity and fashion information source was found. 3. In a fashion opinion leadership model, social character, clothing conformity, and fashion information source have significant direct effects on fashion opinion leadership 4. In a fashion innovativeness model, social character and fashion information source have significant direct effects on fashion innovativeness, and clothing conformity indirect effects through the fashion information source. 5. The explanatory power ($R^2$) was higher for the fashion opinion leadership model than for the fashion innovativeness model.

• Journal of Advanced Navigation Technology
• /
• v.15 no.6
• /
• pp.977-985
• /
• 2011

Airborne separation assurance is a key requirement for Free Flight Airspace operations, This paper study the feasibility of airborne separation assurance for free flight Airspaces operations by evaluating the efficiency measurement models. Three qualitatively different methods are utilized; one based Ground and Air conflict probability model, other based Dynamic Density model. the other based Direct operating cost model. The evaluation is Direct Operating Cost model and Two metrics are utilized for the efficiency measurements; airborne separation assurance performed quite well in the Free Flight evaluation; (1) 2 scenario of the conflict situations are resolved; (2) The MD-80 flight peformed separation assurance and efficiency, Not only appling for geometric method algorithm is more efficiently than potential method, but also the most efficiently geometric combined method.

• Journal of Information Technology Applications and Management
• /
• v.24 no.1
• /
• pp.93-110
• /
• 2017

This study aims at classifying and analyzing the business models of reverse overseas direct purchasing through online shopping-malls. After analyzing the current status of the reverse overseas direct purchasing online markets, this study identifies relevant critical business factors and synthesizes prior studies to construct and analyse the business models. This study proposes that the business models can be classified into five types according to the operation modes and three types according to the delivery methods. So theoretically 15 business models can be identified. For each business model this study analyzes the characteristics and the pros & cons. It also suggests deployment strategies for companies by considering cost reduction, brand establishment, customer management, customer aquisition, and easiness from the business perspective. From the customers perspective, cost reduction, reliability, royalty, ease to purchase, and accessibility can be considered according to the types of operation mode. The main contribution of this study is to provide the basic classifications and structures of reverse overseas direct purchasing business models systematically. As the result, our study evaluates the business models that which one is better than others in a situation in terms of company and customer. Lastly, we talk about limits and future prospects of the study.