• Korean Journal of Childcare and Education
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• v.15 no.3
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• pp.157-174
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• 2019

Objective: The purpose of this study was two-fold: first to explore the effects of mother-child attachment and effortful control at age 1 on preschoolers' school readiness at age 6, and second, to determine the mediating effect of a child's effortful control on the relationship between mother-child attachment at age 1 in relation to school readiness at age 6. Methods: Participants in this study were 205 five-year-old toddlers(106 boys, 99 girls) recruited for the Korea Child Panel Study. Mother-child attachment was assessed using the Attachment Q-sort(Waters, 1989). Preschooler's effortful control was measured by the Early Childhood Behavior Questionnaire: ECBQ(Putnam, Gartstein & Rothbart, 2006). Preschooler's school readness was measured by the School Readiness Scale Murphey & Burns, 2002). Data were analyzed using descriptive statistics, correlations, and the structural equation modeling analysis. Results: First, mother-child attachment at age 1 effected school readiness at age 6. Effortful control at age 1 effected school readiness at age 6. Second, effortful control at age 1 mediated the effect of mother-child attachment at age 1 in relation to school readiness at age 6. Conclusion/Implications: Mother-child attachment at age 1 affects school readiness at age 6, and toddlers' effortful control at age 1 mediates the relationship between mother-child attachment in relation to school readiness at age 6.

• Steel and Composite Structures
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• v.32 no.5
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• pp.595-610
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• 2019

This paper deals with the static and dynamic behavior of Functionally Graded Carbon Nanotubes (FG-CNT)-reinforced porous sandwich (PMPV) polymer plate. The model of nanocomposite plate is investigated within the first order shear deformation theory (FSDT). Two types of porous sandwich plates are supposed (sandwich with face sheets reinforced / homogeneous core and sandwich with homogeneous face sheets / reinforced core). Functionally graded Carbon Nanotubes (FG-CNT) and uniformly Carbon Nanotubes (UD-CNT) distributions of face sheets or core porous plates with uniaxially aligned single-walled carbon nanotubes are considered. The governing equations are derived by using Hamilton's principle. The solution for bending and vibration of such type's porous plates are obtained. The detailed mathematical derivations are provided and the solutions are compared to some cases in the literature. The effect of the several parameters of reinforced sandwich porous plates such as aspect ratios, volume fraction, types of reinforcement, number of modes and thickness of plate on the bending and vibration analyses are studied and discussed. On the question of porosity, this study found that there is a great influence of their variation on the static and vibration of porous sandwich plate.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.2
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• pp.401-410
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• 2021

The study tests resilience and work ethics as mediators between charismatic leadership and affective commitment to change. Many organizations, such as banking, insurance companies, and financial institutions, face strong competition and consequently need to effect considerable change within the organization. Many variables have a significant impact on the success of organizational change, and people (resilience and work ethics) as well as change leaders are primary variables in this research. This study, using structural equation modeling, was conducted on a sample of 355 employees from banking and insurance companies. In this study, the inventory of affective commitment to change, the Conger-Kanungo charismatic leadership scale, resilience, and work ethic inventory was used. The results showed that resilience is a partial mediator between charismatic leadership and affective commitment to change. Meanwhile, work ethic was not a mediator between the two variables. The results showed that charismatic leadership can have a direct, positive, and significant impact on affective commitment to change without mediators, and that resilience can act as partial mediator. Furthermore, work ethic had a significant and positive effect on affective commitment to change through resilience. In other words, resilience is a full mediator for the impact of work ethic on affective commitment to change.

• Nuclear Engineering and Technology
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• v.55 no.9
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• pp.3388-3400
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• 2023

Detailed analysis of the neutron pathway through matter inside the nuclear reactor core is exceedingly needed for safety and economic considerations. Due to the constant development of high-performance computing technologies, neutronics analysis using computer codes became more effective and efficient to perform sophisticated neutronics calculations. In this work, a commercial pressurized water reactor (PWR) presented by Virtual Environment for Reactor Applications (VERA) Core Physics Benchmark are modeled and simulated using a high-fidelity simulation of OpenMC code in terms of criticality and fuel pin power distribution. Various problems have been selected from VERA benchmark ranging from a simple two-dimension (2D) pin cell problem to a complex three dimension (3D) full core problem. The development of the code capabilities for reactor physics methods has been implemented to investigate the accuracy and performance of the OpenMC code against VERA SCALE codes. The results of OpenMC code exhibit excellent agreement with VERA results with maximum Root Mean Square Error (RMSE) values of less than 0.04% and 1.3% for the criticality eigenvalues and pin power distributions, respectively. This demonstrates the successful utilization of the OpenMC code as a simulation tool for a whole core analysis. Further works are undergoing on the accuracy of OpenMC simulations for the impact of different fuel types and burnup levels and the analysis of the transient behavior and coupled thermal hydraulic feedback.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1179-1186
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• 2022

Building Information Modeling (BIM) is widely used to efficiently share, utilize and manage information generated in every phase of a construction project. Recently, mixed reality (MR) technologies have been introduced to more effectively utilize BIM elements. This study deals with the haptic interactions between humans and BIM elements in MR to improve BIM usability. As the first step in interacting with virtual objects in mixed reality, we challenged moving a virtual object to the desired location using finger-pointing. This paper presents the procedure of developing a haptic interface system where users can interact with a BIM object to move it to the desired location in MR. The interface system consists of an MR-based head-mounted display (HMD) and a mobile application developed using Unity 3D. This study defined two segments to compute the scale factor and rotation angle of the virtual object to be moved. As a result of testing a cuboid, the user can successfully move it to the desired location. The developed MR-based haptic interface can be used for aligning BIM elements overlaid in the real world at the construction site.

• Journal of the Korean earth science society
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• v.45 no.4
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• pp.338-348
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• 2024

In the mid-eastern part of the Yellow Sea, large-scale shelf ridges originated from erosion on sand-mud successions that have been presently eroded by strong tidal currents. A three-layered in situ geoacoustic model is provided down to 50 m for the subbottom sedimentary succession of a 45 m water depth using the Hamilton method. The succession is divisible into two-type units of Type-A and Type-B using high-resolution seismic profiles with a deep-drilled YSDP-104 core of 44.0 m in depth below the seafloor. Type-A unit mainly comprises sandy or gravelly sediments, whereas Type-B unit mostly consists of tidal muddy sediments with some thinner sand beds. P-wave speed values are positively compatible with the mean grain size and sediment type of the core sediments. For actual modeling, the geoacoustic property values of the models were compensated to in situ depth values below the seafloor. The detailed geoacoustic model contributes to simulating sound transmission through the sedimentary successions in erosional shelf ridges of variable geoacoustic properties distributed in shallow-water environments of the mid-eastern Yellow Sea.

• Wind and Structures
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• v.39 no.3
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• pp.163-174
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• 2024

This paper analyzes La Rumorosa I Wind Farm's wind states and their characteristics in the operation of two wind turbines over the course of one year of records. This information identifies the impact of wind states on wind power output. The study used the Gaussian Mixture Model to classify the occurrence and frequency of the dominant wind states in the generation of energy from the turbines. Results were obtained for mesoscale wind states and local scale wind states, such as cold fronts and Santa Ana winds, as well as daytime, nighttime and hot days, respectively, which were statistically analyzed to determine their relationship to power output by generating power and power coefficient curves. Between the cut-in speed and the rated speed of the wind turbines, cold fronts show higher efficiency, unlike nighttime wind states, which are the most efficient past the rated speed. In addition, cold fronts are also those that occur to the greatest extent, contributing 31.26% of the energy produced per year, compared with the Santa Ana winds, which occur to a lesser extent; however, they contribute 22.11% of the energy produced per year.

• Science of Emotion and Sensibility
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• v.15 no.2
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• pp.283-296
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• 2012

The goal of this study is to determine the social emotion model as an emotion sharing relationship and information sharing relationship based on the user's relations at social networking services. 26 social emotions were extracted by verification of compliance among 92 different emotions collected from the literature survey. The survey on the 26 emotion words was verified to the similarity of social relation types to the Likert 7-points scale. The principal component analysis of the survey data determined 12 representative social emotions in the emotion sharing relation and 13 representative social emotions in the information sharing relation. Multidimensional scaling developed the two-dimensional social emotion model of emotion sharing relation and of information sharing relation based on online communication environment. Meanwhile, insignificant factors in the suggest social emotion models were removed by the structural equation modeling analysis, statistically. The test result of validity analysis demonstrated the fitness of social emotion models at emotion sharing relationships (CFI: .887, TLI: .885, RMSEA: .094), social emotion model of information sharing relationships (CFI: .917, TLI: .900, RMSEA : 0.050). In conclusion, this study presents two different social emotion models based on two different relation types. The findings of this study will provide not only a reference of evaluating social emotions in designing social networking services but also a direction of improving social emotions.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.6
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• pp.49-59
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• 2008

SIFT(Scale Invariant Feature Transform) is an algorithm to extract vectors at pixels around keypoints, in which the pixel colors are very different from neighbors, such as vortices and edges of an object. The SIFT algorithm is being actively researched for various image processing applications including 3-D image constructions, and its most computation-intensive stage is a keypoint localization. In this paper, we develope a fixed-point model of the keypoint localization and propose its efficient hardware architecture for embedded applications. The bit-length of key variables are determined based on two performance measures: localization accuracy and error rate. Comparing with the original algorithm (implemented in Matlab), the accuracy and error rate of the proposed fixed point model are 93.57% and 2.72% respectively. In addition, we found that most of missing keypoints appeared at the edges of an object which are not very important in the case of keypoints matching. We estimate that the hardware implementation will give processing speed of $10{\sim}15\;frame/sec$, while its fixed point implementation on Pentium Core2Duo (2.13 GHz) and ARM9 (400 MHz) takes 10 seconds and one hour each to process a frame.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.221-221
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• 2014

The present work proposes an improved numerical simulator for design and modification of large area capacitively coupled plasma (CCP) processing chamber. CCP, as notoriously well-known, demands the tremendously huge computational cost for carrying out transient analyses in realistic multi-dimensional models, because electron dissociations take place in a much smaller time scale (${\Delta}t{\approx}10-8{\sim}10-10$) than time scale of those happened between neutrals (${\Delta}t{\approx}10-1{\sim}10-3$), due to the rf drive frequencies of external electric field. And also, for spatial discretization of electron flux (Je), exponential scheme such as Scharfetter-Gummel method needs to be used in order to alleviate the numerical stiffness and resolve exponential change of spatial distribution of electron temperature (Te) and electron number density (Ne) in the vicinity of electrodes. Due to such computational intractability, it is prohibited to simulate CCP deposition in a three-dimension within acceptable calculation runtimes (<24 h). Under the situation where process conditions require thickness non-uniformity below 5%, however, detailed flow features of reactive gases induced from three-dimensional geometric effects such as gas distribution through the perforated plates (showerhead) should be considered. Without considering plasma chemistry, we therefore simulated flow, temperature and species fields in three-dimensional geometry first, and then, based on that data, boundary conditions of two-dimensional plasma discharge model are set. In the particular case of SiH4-NH3-N2-He CCP discharge to produce deposition of SiNxHy thin film, a cylindrical showerhead electrode reactor was studied by numerical modeling of mass, momentum and energy transports for charged particles in an axi-symmetric geometry. By solving transport equations of electron and radicals simultaneously, we observed that the way how source gases are consumed in the non-isothermal flow field and such consequences on active species production were outlined as playing the leading parts in the processes. As an example of application of the model for the prediction of the deposited thickness uniformity in a 300 mm wafer plasma processing chamber, the results were compared with the experimentally measured deposition profiles along the radius of the wafer varying inter-electrode gap. The simulation results were in good agreement with experimental data.