• Korean Journal of School Psychology
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• v.16 no.1
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• pp.1-15
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• 2019

The purpose of this study was to explore the concurrent and lagged effects of parental neglect and abuse on longitudinal changes in late childhood school adjustment. This study utilized survey data from the fourth through seventh iterations of the Korean Child Youth Panel Study conducted on fourth-year elementary school students through first-year middle school students. The data was analyzed using latent growth modeling. The results were as follows. First, the level of school adjustment decreased gradually. Second, both neglect and abuse had concurrent effects on school adjustment. Third, neglect had lagged effects on school adjustment but abuse did not. The paper discusses the implications of these results. The results of this study can be used to better understand and support children who have suffered neglect or abuse adjust to school during late childhood.

• Particle and aerosol research
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• v.9 no.3
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• pp.163-171
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• 2013

Soot particles emitted from combustion processes are often coated by non-absorbing organic materials, which enhance the global warming effect of soot particles. It is of importance to study the condensation characteristics of soot particles experimentally and theoretically to reduce the uncertainty of the climate impact of soot particles. In this study, the condensational growth of soot particles in a tubular coater was modeled by a one-dimensional (1D) plug flow model and a two-dimensional (2D) laminar flow model. The effects of 2D heat and mass transports on the predicted particle growth were investigated. The temperature and coating material vapor concentration distributions in radial direction, which the 1D model could not accounted for, affected substantially the particle growth in the coater. Under the simulated conditions, the differences between the temperatures and vapor concentrations near the wall and at the tube center were large. The neglect of these variations by the 1D model resulted in a large error in modeling the mass transfer and aerosol dynamics occurring in the coater. The 1D model predicted the average temperature and vapor concentration quite accurately but overestimated the average diameter of the growing particles considerably. At the outermost grid, at which condensation begins earliest due to the lowest temperature and saturation vapor concentration, condensing vapor was exhausted rapidly because of the competition between condensations on the wall and on the particle surface, decreasing the growth rate. At the center of the tube, on the other hand, the growth rate was low due to high temperature and saturation vapor concentration. The effects of Brownian diffusion and thermophoresis were not high enough to transport the coating material vapor quickly from the tube center to the wall. The 1D model based on perfect radial mixing could not take into account this phenomenon, resulting in a much higher growth rate than what the 2D model predicted. The result of this study indicates that contrary to a previous report for a thermodenuder, 2D heat and mass transports must be taken into account to model accurately the condensational particle growth in a coater.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.4
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• pp.409-417
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• 2014

To prevent the occurrence of fractures in metal structures, it is very important to evaluate the 3D crack growth process in those structures and any related parts. In this study, tension tests and two simulations, namely, Simulation-I and Simulation-II, were performed using XFEM to evaluate crack growth in three dimensions. In the tension test, Mode I crack growth was observed for a notched metal specimen. In Simulation-I, a 3D reconstructed model of the specimen was created using CT images of the specimen. Using this model, an FE model was constructed, and crack growth was simulated using XFEM. In Simulation-II, an ideal notch FE model of the same geometric size as the actual specimen was created and then used for simulation. Obtained crack growth simulation results were then compared. Crack growth in the metal specimen was evaluated in three dimensions. It was shown that modeling the real shape of a structure with a crack may be essential for accurately evaluating 3D crack growth.

• Journal of Bio-Environment Control
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• v.10 no.3
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• pp.133-140
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• 2001

This study was conducted to develop a nutrient uptake model in cucumnber (Cucumis sativus L. cv. Eunsung Backdadagi) plants for prediction of the amount of nutrients in drainage solution in a closed perlite culture system. Electrical conductivity (EC) of the nutrient solution was adjusted to 1.5, 1.8, 2.1, 2.4, and 2.7 dS. $m^{-1}$ . The amount of nutrient solution absorbed in different EC treatments was not different until the mid stage of growth. However, after the mid growth stage, a high EC treatment resulted in less solution absorption. The absorption rates of K, N $O_3$$^{[-10]}$ -N, Mg, and P increased continuously for a whole growing period in all treatments, while those of Ca decreased slightly. For S, the decrease was significant after th mid stage of growth. although the amounts of absorbed inorganic ions in different EC treatments were not significantly different at the first stage of growth, they were significantly different after the mid stage of growth and decreased slightly at the end of growth stage. Models for predicting the amounts of each inorganic ion absorbed were developed by using EC and the amount of nutrient solution absorbed per unit radiation(mg.M $J^{-1}$), which proved to be practical with a positive correlation at 1 percent probability between the developed model and practical values..

• International Journal of Highway Engineering
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• v.8 no.1 s.27
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• pp.139-152
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• 2006

Many experimental and numerical approaches have been developed to evaluate paving materials and to predict pavement response and distress. Micromechanical simulation modeling is a technology that can reduce the number of physical tests required in material formulation and design and that can provide more details, e.g., the internal stress and strain state, and energy evolution and dissipation in simulated specimens with realistic microstructural features. A clustered distinct element modeling (DEM) approach was implemented In the two-dimensional particle flow software package (PFC-2D) to study the complex behavior observed in asphalt mixture fracturing. The relationship between continuous and discontinuous material properties was defined based on the potential energy approach. The theoretical relationship was validated with the uniform axial compression and cantilever beam model using two-dimensional plane strain and plane stress models. A bilinear cohesive displacement-softening model was implemented as an intrinsic interface and applied for both homogeneous and heterogeneous fracture modeling in order to simulate behavior in the fracture process zone and to simulate crack propagation. A disk-shaped compact tension test (DC(T)) with heterogeneous microstructure was simulated and compared with the experimental fracture test results to study Mode I fracture. The realistic arbitrary crack propagation including crack deflection, microcracking, crack face sliding, crack branching, and crack tip blunting could be represented in the fracture models. This micromechanical modeling approach represents the early developmental stages towards a 'virtual asphalt laboratory,' where simulations of laboratory tests and eventually field response and distress predictions can be made to enhance our understanding of pavement distress mechanisms, such its thermal fracture, reflective cracking, and fatigue crack growth.

• The KIPS Transactions:PartD
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• v.10D no.3
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• pp.489-500
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• 2003

Due to the rapid growth of Internet, modern software applications must support many web-based functionalities than traditional software applications. These web-based functional supports increase the complexity of software architecture and the cost of software development. Therefore, the development of an efficient environment that web characteristics are well reflected is the most important. In this thesis, we have presented an efficient environment for development of web applications. For the presented environment, after considering the web characteristics, we defined a Process for web applications and modeling environment. The Presented environment has three main functions : $\circled1$ it Provides a modeling environment for design of web-based applications, $\circled2$ it has a modeling language called WML(web-application modeling language), $\circled3$ it automatically extracts web pages from diagrams. As a result, using the three main functions of the presented environment, we can easily design, develop, and maintain the web applications.

• Journal of Korea Game Society
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• v.13 no.2
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• pp.49-58
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• 2013

In this study, a tree growth model is designed to represent a variety of trees consisting of a outdoor terrain of game efficiently and naturally. The proposed tree growth model is an integrated tree growth model, and is configured using the following approaches: (1) the tree modeling method based on growth volume and the convolution sums of divisor functions, which is used to model a variety kind of trees more intuitively and naturally; (2) a rendering method using a level of detail of branch based on instancing for real-time processing of numerous trees with complicated structures; and (3) a combination of the above methods to efficiently implement a game landscape. The natural and diverse growths of trees that emerged using the proposed tree growth model is evaluated through experimentation, along with the possibility of implementing the natural game landscape and the efficiency of real-time processing.

• Animal Bioscience
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• v.37 no.5
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• pp.817-825
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• 2024

Objective: The aim of this study was to identify suitable polynomial regression for modeling the average growth trajectory and to estimate the relative development of the rib eye area, scrotal circumference, and morphometric measurements of Guzerat young bulls. Methods: A total of 45 recently weaned males, aged 325.8±28.0 days and weighing 219.9±38.05 kg, were evaluated. The animals were kept on Brachiaria brizantha pastures, received multiple supplementations, and were managed under uniform conditions for 294 days, with evaluations conducted every 56 days. The average growth trajectory was adjusted using ordinary polynomials, Legendre polynomials, and quadratic B-splines. The coefficient of determination, mean absolute deviation, mean square error, the value of the restricted likelihood function, Akaike information criteria, and consistent Akaike information criteria were applied to assess the quality of the fits. For the study of allometric growth, the power model was applied. Results: Ordinary polynomial and Legendre polynomial models of the fifth order provided the best fits. B-splines yielded the best fits in comparing models with the same number of parameters. Based on the restricted likelihood function, Akaike's information criterion, and consistent Akaike's information criterion, the B-splines model with six intervals described the growth trajectory of evaluated animals more smoothly and consistently. In the study of allometric growth, the evaluated traits exhibited negative heterogeneity (b<1) relative to the animals' weight (p<0.01), indicating the precocity of Guzerat cattle for weight gain on pasture. Conclusion: Complementary studies of growth trajectory and allometry can help identify when an animal's weight changes and thus assist in decision-making regarding management practices, nutritional requirements, and genetic selection strategies to optimize growth and animal performance.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.10 no.1
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• pp.113-121
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• 2014

In this work, an integrated model including molecular dynamics and chemical rate theory was implemented to calculate the growth of point defect clusters(PDC) and copper-rich precipitates(CRP) which could change the mechanical properties of reactor pressure vessel(RPV) steels in a nuclear power plant. A number of time-dependent differential equations were established and numerically integrated to estimate the evolution of irradiation defects. The calculation showed that the concentration of the vacancies was higher than that of the self-interstitial atoms. The higher concentration of vacancies induced a formation of the CRPs in the later stage. The size of the CRPs was used to estimate the mechanical property changes in RPV steels, as is the same case with the PDCs. The calculation results were compared with the measured values of yield strength change and Charpy V-notch transition temperature shift, which were obtained from the surveillance test data of Korean light water reactors(LWRs). The estimated values were in fair agreement with the experimental results in spite of the uncertainty of the modeling parameters.

• Journal of Korean Institute of Industrial Engineers
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• v.43 no.3
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• pp.213-228
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• 2017

Augmented reality (AR), which is a live direct or indirect view of a real-world environment combined with virtual objects, has grown rapidly owing to its wide application potential. Despite the growth of AR technology and its increased attraction, however, little attention has been paid to identifying sub-technologies of this technology and their evolving trends based on the data encompassing industrial competition. In the present study, therefore we collect AR-related patents granted until 2015 and then identify technology topics constituting AR technology by applying topic modeling to the patents' textual data. Subsequently, this study determines dynamic evolving trends with respect to those identified technology topics using indicators and maps based on the technology topics' patents and citations. The contributions of this study are twofold; it provides an overall understanding of AR technology's evolving trends based on text mining of AR patents and will assist technology experts in academia and industry in determining further R&D in the near future.