• Journal of Ocean Engineering and Technology
• /
• v.25 no.4
• /
• pp.36-41
• /
• 2011

In the present paper, a direct forcing/fictitious domain (DF/FD) level set method is proposed to simulate the FSI (fluid-solid interaction) in two-phase flow. The main idea is to combine the direct-forcing/fictitious domain (DF/FD) method with the level set method in the Cartesian coordinates. The DF/FD method is a non-Lagrange-multiplier version of a distributed Lagrange multiplier/fictitious domain (DLM/FD) method. This method does not sacrifice the accuracy and robustness by employing a discrete ${\delta}$ (Dirac delta) function to transfer quantities between the Eulerian nodes and Lagrangian points explicitly as the immersed boundary method. The advantages of this approach are the simple concept, easy implementation, and utilization of the original governing equation without modification. Simulations of various water-entry problems have been conducted to validate the capability and accuracy of the present method in solving the FSI in two-phase flow. Consequently, the present results are found to be in good agreement with those of previous studies.

• Korean Journal of Childcare and Education
• /
• v.15 no.2
• /
• pp.59-76
• /
• 2019

Objective: The purpose of this study was to analyze the structural relationship and influence of parents' family interaction, parenting efficacy, and child internalizing and externalizing problem behaviors. Methods: 1,418 children and their parents, and survey data from a panel study on Korean children (2014), were used to analyze the structural equation model. Results: First, the mother's family interaction had direct influence on their parenting efficacy, as well as their child's internalization and externalization. Second, the father's family interaction had a direct influence only on the internal problem behaviors of the child, and child external problem behaviors were influenced through the father's parenting efficacy. Third, parenting efficacy mediated the effects of family interaction on the problem behavior of children. Especially, the father's family interaction was found to affect child variables through the mother's parenting efficacy. Finally, the internalizing problem behaviors of the child mediated the effects of the parents' family interaction and parenting efficacy on child externalizing problem behaviors. Conclusion/Implications: The results of this study are significant in that the factors of father, mother, and child are interrelated, and that parent interaction has varying influence on the problems of their children.

• Journal of the Korean Magnetics Society
• /
• v.3 no.3
• /
• pp.173-178
• /
• 1993

We have calculated the reduced spontaneous magnetization in different environments and average value as func¬tion of reduced temperature of the magnetic ions(Fe) for A(tetrahedral) and B(octahedral) sites in spinel ferrites $AB_{2}O_{4}$ using A-O-B superexchange interaction. The reduced spontaneous magnetization and average value by A-O-B superexchange interaction are compared with that by A-B direct interaction. To contrast A-O-B superexchange interaction with A-B direct interaction, $M\"{o}ssbauer$ spectra from previous two interactions are obtained.

• Journal of The Korean Association For Science Education
• /
• v.28 no.7
• /
• pp.759-767
• /
• 2008

This article arose from the previous studies, which suggested a synthetic list for the nature of science (NOS), discussed the relationship between the NOS and scientific inquiry and the development of the NOS in the context of scientific inquiry. In this article, for teaching scientific inquiry through the NOS, I proposed three teaching models - reflection, interaction, and the direct model -. Within these teaching models, understanding the NOS is viewed as a prerequisite condition for the improved performance of scientific inquiry. In the reflection model, the NOS is embedded and reflected in scientific inquiry without explicit introduction or direct explanation of the NOS. In the interaction model, concrete interaction between scientific inquiry and the NOS is encouraged during the process of scientific inquiry. In the direct model, subsequent to directly comprehending the NOS at the first stage of activity, students conduct scientific inquiry based on their understanding of the NOS. The intention of this present article is to facilitate the use of these models to develop teaching materials for more authentic scientific inquiry.

• Archives of Pharmacal Research
• /
• v.26 no.10
• /
• pp.846-854
• /
• 2003

The oligomerization of G-proteincoupled receptors (GPCRs) has been shown to occur by various mechanisms, such as via disulfide covalent linkages, non covalent (ionic, hydrophobic) interactions of the N-terminal, and/or transmembrane and/or intracellular domains. Interactions between GPCRs could involve an association between identical proteins (homomers) or non-identical proteins (heteromers), or between two monomers (to form dimers) or multiple monomers (to form oligomers). It is believed that muscarinic receptors may also be arranged into dimeric or oigomeric complexes, but no systematic experimental evidence exists concerning the direct physical interaction between receptor proteins as its mechanism. We undertook this study to determine whether muscarinic receptors form homomers or a heteromers by direct protein-protein interaction within the same or within different subtypes using a yeast two-hybrid system. Intracellular loops (i1, i2 and i3) and the C-terminal cytoplasmic tails (C) of human muscarinic (Hm) receptor subtypes, Hm1, Hm2 and Hm3, were cloned into the vectors (pB42AD and pLexA) of a two-hybrid system and examined for heteromeric or homodimeric interactions between the cytoplasmic domains. No physical interaction was observed between the intracellular domains of any of the Hm/Hm receptor sets tested. The results of our study suggest that the Hm1, Hm2 and Hm3 receptors do not form dimers or oligomers by interacting directly through either the hydrophilic intracellular domains or the C-terminal tail domains. To further investigate extracellular domain interactions, the N-terminus (N) and extracellular loops (o1 and o2) were also cloned into the two-hybrid vectors. Interactions of Hm2N with Hm2N, Hm2o1, Hm2o2, Hm3N, Hm3o1 or Hm3o2 were examined. The N-terminal domain of Hm2 was found to have no direct interaction with any extracellular domain. From our results, we excluded the possibility of a direct interaction between the muscarinic receptor subtypes (Hm1, Hm2 and Hm3) as a mechanism for homo- or hetero-meric dimerization/oligomerization. On the other hand, it remains a possibility that interaction may occur indirectly or require proper conformation or subunit formation or hydrophobic region involvement.

• Earthquakes and Structures
• /
• v.12 no.2
• /
• pp.251-262
• /
• 2017

The present research intends to study the effects of the seismic soil-foundation-structure interaction (SFSI) on the dynamic response of various buildings. Two methods including direct and Cone model were studied through 3D finite element method using ABAQUS software. Cone model as an approximate method to consider the SFSI phenomenon was developed and evaluated for both high and low rise buildings. Effect of soil nonlinearity, foundation rigidity and embedment as well as friction coefficient between soil-foundation interfaces during seismic excitation are investigated. Validity and performance of both approaches are evaluated as reference graphs for Cone model and infinite boundary condition, soil nonlinearity and amplification factor for direct method. A series of calculations by DeepSoil for inverse earthquake record modification was conducted. A comparison of the two methods was carried out by root-mean-square-deviation (RMSD) tool for maximum lateral displacement and story shear forces which verifies that Cone model results have good agreement with direct method. It was concluded that Cone method is a convenient, fast and rather accurate method as an approximate way to count for soil media.

• Journal of Korean Academy of Nursing Administration
• /
• v.3 no.2
• /
• pp.123-136
• /
• 1997

The purpose of this study was to confirm the classification of nursing activity and to analyze the time of nursing workload in a new open hospital. The data were collected from 20 nurses working in 6 general nursing units by 4 trained observers. The tools used for this study were an observation recording sheet and a classification sheet of nursing activity. The classification sheet was constructed to be adaptable to each hospital system based on the instrument described in the literature. The results of the study are as follows : The direct nursing activities consisted of 6 sections, 33 subsections and the indirect nursing activities consisted of 14 sections, 53 subsections. The direct nursing activities included medication, measuring and observation, care of therapies, care of physical comfort, laboratory and treatment. The indirect nursing activities included preparation of medical utensils, collection of information and assessment, recording, phone communication, professional interaction related to patients, personal time, assigning work to staff, patient eaucation and training, interaction with lab, transfer of administration of utensils, checking physician's order, dietary service, management of pollution and contagion, guide direction. Nurses spent 127.6min for direct nursing activity during day duty. It was 24.5% of total nursing activity. Within that activity medication had the highest percentage of time(40.09%), followed by communication and education with patient(24.76%), measuring and observation (16.93%), laboratory and treatment (12.85%), care of therapies(3.21%) and care of physical comfort (2.16%). The time breakdown for indirect nursing activities is as follows ; the preparation of medical utensils 22.3%, collection of information and assessment 20.29%, recording 20.27%, phone communication 8.14%, professional interaction related to patients 7.33%, personal time 7.24%, with the remaining timeshared by staffing, patient education and training, interaction with lab, transfer of administration of utensils, checking physician's order, dietary service, management of pollution and contagion, guide direction. In the analysis of the relationships between the working time and the work allocation characters of the nurses(including nurse's experiences. nurse-patients ratio, nurse-rooms ratio, and character of nursing unit) ; There were no significant differences in direct-indirect nursing times between nurse's career years. There was significant difference in direct nursing time between assigned patient numbers. The nurses assigned larger number of patients spent significantly more time in direct nursing care than that of the smaller. On the other hand, there was no significant difference in indirect nursing workload between the assigned patient numbers. There were no significant differences in direct-indirect nursing time between an allocated patient's room numbers. There was significant difference in working time between working places. The nurse in the medical unit spent more time in direct nursing care than her counterpart in the surgical unit. However there was no difference in direct nursing time between two groups. The study results indicate that nurses spent less time in the direct nursing care than in the previous studies even though the hospital system has been modernized. On the other hand they spent much more time for the coordinating role within the interdisciplinary team and for the overlapping paperwork. Therefore it is recommended that patient oriented job description and more efficient usage of modernized utilities be made.

• Bulletin of the Korean Chemical Society
• /
• v.22 no.9
• /
• pp.945-947
• /
• 2001

The He-Xe interaction potential has been determined using a direct inversion of the experimentally reduced-viscosity collision integrals obtained from the corresponding states correlation. The potential is in a good agreement with the previously determined potential. The potential predicts viscosity and diffusion coefficients and they are found to be in a good agreement with experiment.

• Structural Monitoring and Maintenance
• /
• v.1 no.2
• /
• pp.213-230
• /
• 2014

A novel real-time actuator failure detection algorithm is developed in this paper. Actuator fails when the input to the structure is different from the commanded one. Previous research has shown that one error function can be formulated for each actuator through interaction matrix method. For output without noise, non-zero values in the actuator functions indicate the instant failure of the actuator regardless the working status of other actuators. In this paper, it is further demonstrated that the actuator's error function coefficients will be directly calculated from the healthy input of the examined actuator and all outputs. Hence, the need for structural information is no longer needed. This approach is termed as direct method. Experimental results from a NASA eight bay truss show the successful application of the direct method for isolating and identifying the real-time actuator failure. Further, it is shown that the developed method can be used for real-time sensor failure detection.

• Asian-Australasian Journal of Animal Sciences
• /
• v.10 no.5
• /
• pp.510-513
• /
• 1997

This study examined the effects of ignoring inbreeding depression on (co)variance components for weaning weight through the use of Monte Carlo simulation. Weaning weight is of particular interest as a trait for which additive direct and maternal genetic components exist and there then is the potential for a direct-maternal genetic covariance. Ignoring inbreeding depression in the analytical model (.8 kg reduction of phenotypic value per 1% inbreeding) led to biased estimates of all genetic (co) variance components, all estimates being larger than the true values of the parameters. In particular, a negative bias in the direct-maternal genetic covariance was observed in analyses that ignored inbreeding depression. A small spurious sire-by-year interaction variance was also observed.