• Journal of Families and Better Life
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• v.25 no.4
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• pp.43-55
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• 2007

The Purpose of this study was to investigate the ecological variables on adolescent's sociometric popularity. Independent variables were organism(sex, age, aggression, self-esteem, impulsiveness, prosocial behavior, dominance), microsystem(parenting style, family support, friends relationship, teacher support), mesosystem(family-peer relationship, family-school relationship), and exosystem(positive community environment, social support of extended family, school's policy). The subjects were 835 - 1st and 2nd graders of two middle and two high schools in Daegu. Adolescent's sociometric popularity and ecological variables were measured with questionnaire. Adolescent's sociometric popularity was measured with sociometric popularity questionnaire. Organism variables were measured with sex, age, aggression, self-esteem, impulsiveness, prosocial behavior and dominance questionnaire. Microsystem variables were measured with parenting style, family support, friends relationship and teacher support questionnaire. Mesosystem variables were measured with family-peer relationship and family-school relationship questionnaire. Exosystem variables were measured with positive community environment, social support of extended family and school's policy questionnaire. The data analyzed by frequency, percentage, mean, cronbach's $\alpha$, and multiple regression. The major findings were as follows: First, adolescent's sociometric popularity was affected by age, overt aggression, academic self-esteem, social self-esteem, and impulsiveness of organism variables. Second, adolescent's sociometric popularity was affected by mother's affectional parenting, mother's control parenting, and attachment to friends of microsystem variables. Third, adolescent's sociometric popularity was affected by family - peer relationship and family - school relationship of mesosystem variables. Fourth, adolescent's sociometric popularity was affected by appraisal support of extended family, after-school activity, and circle activity of exosystem variables.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.5
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• pp.1015-1024
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• 2015

An experiment of composite beam was performed which utilized glass fiber reinforced polymer (GFRP) plank as the permanent formwork with cast-in-place high strength concrete. This research analyzed the flexural failure behavior of composite beam by setting the sand coated at GFRP bottom surface, the perforation and interval of the GFRP plank web, and the width of the top flange as the experimental variables. As a result of the experiments for effectiveness of sand attachment in case of not perforated web, approximately 43% higher ultimate load value was obtained when the sand was coated than not coated case. For effectiveness of perforation and interval of gap, approximately 23% higher maximum load value was seen when interval of the perforation gap was 3 times and the fine aggregate was not coated, and approximately 11% higher value was observed when the perforation gap was 5 times on the coated specimen. For effectiveness of top flange breadth, the ultimate load value was approximately 12% higher in case of 20mm than 40mm width.

• Journal of Korea Foundry Society
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• v.29 no.5
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• pp.225-232
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• 2009

For comprehensive understanding of the formation behavior of $\beta-Al_5FeSi$ phase in Al-Si-Cu alloys with the existence of Fe element, microstructure characterizations were performed using combined analysis of OM, SEM-EDS, XRD. Especially, experimental and predictive works on solidification events of $\beta-Al_5FeSi$ phase as well as other phases formed together with $\beta-Al_5FeSi$ have been carried out by using DSC analysis and Java-based Materials Properties software (J. Mat. Pro.). Primary and eutectic $\beta-Al_5FeSi$ phases were able to distinguish from each other on microstructures by their morphological features. Primary $\beta-Al_5FeSi$ phase was seen to have rough surface perpendicular to growth direction, indicating free attachment of solute atoms in liquid state. On the other hand, the eutectic $\beta-Al_5FeSi$ phase was formed with plain and straight surface during eutectic reaction together with $\alpha$-Al phase. The eutectic reaction of $\beta-Al_5FeSi$ and $\alpha$-Al phases was seen to be able to separate into each formation depending on cooling rate.

• Biomaterials and Biomechanics in Bioengineering
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• v.2 no.1
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• pp.47-59
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• 2015

A bioactive and multifunctional elastin-like polymer (ELP) was produced by genetic engineering techniques to develop new artificial matrices with the ability to mimic the extracellular matrix (ECM). The basic composition of this ELP is a thermo- and pH-sensitive elastin pentapeptide which has been enriched with RGD-containing domains, the RGD loop of fibronectin, for recognition by integrin receptors on their sequence to promote efficient cell attachment. Hydrogels of this RGD-containing polymer were obtained by crosslinking with hexamethylene diisocyanate, a lysine-targeted crosslinker. These materials retain the "smart" nature and temperature-responsive character, and the desired mechanical behavior of the elastin-like polymer family. The influence of the degree of crosslinking on the morphology and properties of the matrices were tested by calorimetric techniques and scanning electron microscopy (SEM). Their mechanical behavior was studied by dynamical mechanical analysis (DMA). These results show the potential of these materials in biomedical applications, especially in the development of smart systems for tissue engineering.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.22 no.4
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• pp.219-227
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• 2011

Objectives : This study examined maternal object relations, child's and mother's perception on rearing attitude, and children's self-esteem in children with attention-deficit hyperactivity disorder (ADHD) and their mothers. Methods : 64 children with ADHD and their mothers were included in the study group. In the control group, there were 85 children and their mothers. Mothers completed the following tests : Bell object relation inventory (BORI), maternal behavior research instrument (MBRI), Beck Depression Inventory (BDI), and Korean ADHD Rating Scale (K-ARS). Children completed Children's Report of Parental Behavior Inventory (CRPBI) and Rosenberg self-esteem scale. Results : Mothers of ADHD children displayed more rejecting and controlling parenting style than mothers in the control group. ADHD children showed lower self-esteem and perceived their parents as not affectionate, but rejecting and controlling. Mothers with ADHD children who belonged to object relations pathological group showed more rejecting rearing attitude and their children believed that they were more controlling, compared with children and mothers in other conditions. Among factors in mother's object relations, insecure attachment and ego-centricity impacted the rearing attitude. In turn, affective rearing attitude mainly influenced children's self-esteem. Conclusion : This study suggests that the approach focused on mother's object relations may help with the treatment of children with ADHD.

• Journal of Periodontal and Implant Science
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• v.51 no.4
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• pp.254-263
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• 2021

Purpose: Periodontitis is associated with a dysbiosis of periodontopathic bacteria, which stimulate the interleukin (IL)-23/IL-17 axis that plays an essential role in the immunopathogenesis of this disease, leading to alveolar bone destruction through receptor activator of nuclear factor κB ligand (RANKL). IL-23 receptor mRNA (IL-23R) has been identified in periodontitis, and IL-17 receptor A mRNA (IL-17RA) and its protein have not yet been evaluated in patients with periodontitis. In this study was measure IL-23R and IL-17RA in gingival tissue (GT) from patients with generalized chronic periodontitis (GCP) and generalized aggressive periodontitis (GAP) and to explore correlations with clinical parameters. Methods: We included 16 healthy subjects (HS), 18 patients with GCP, and 14 with GAP. GT samples were collected during periodontal surgery. Both IL-23R and IL-17RA were detected by enzyme-linked immunosorbent assay. Results: The results were analyzed with Mann-Whitney U test and Spearman' rank correlation coefficients using SPSS version 25.0. We found lower IL-23R levels in patients with GCP and GAP than in HS. Contrarily, we observed higher IL-17RA levels in GCP and GAP patients than in HS. Moreover, we found negative correlations between IL-23R in GT and probing depth and clinical attachment loss (CAL). Likewise, a positive correlation of IL-17RA in GT with CAL was found. Conclusions: The results of these findings suggest that the reverse behavior between IL-23R and IL-17RA in periodontitis patients may also be involved with the activation of RANKL, which promotes alveolar bone loss.

• Tribology and Lubricants
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• v.40 no.2
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• pp.61-66
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• 2024

Micro-plastics are synthetic high-differentiation chemicals of less than 5mm in size, and are deposited not only on the sea surface but also on the coast. If these micro-plastics are not properly separated from the sand, they can threaten marine ecosystems. Thus, in the present study, we aimed to apply cyclone separator to the micro-plastic retrieval in order to predict the movement of particles according to the formation of the cyclone separator by applying the centrifugal force of the particle in accordance with the rotational movement of the air. The cyclone separator has three shapes, the first one is a typical interconnected cyclone separator. The second is the horn form, except for the cylinder in a regular cyclone separator, and the third is a form that increases the horn's height twice in the second. The numerical analysis simulation of the Cyclone separator used the Fluent software package. The output speed of the Cyclone separator was 5 to 13m/s at 1m/s intervals. The simulated particles include sand, Styrofoam, PET, PP, and PU. Sand particles are assigned a fixed diameter of 2mm, while other particles have a diameter of 3mm. As a result of the analysis, the first form was not separated from plastic. The Styrofoam separation efficiency in the second showed its highest efficiency at 72.7% at 7m/s, and the efficiency decreased after 12m/s as the sand particles were mixed into the plastic attachment location. In the third form, the separation efficiency of Styrofoam at 12m/s was highest at 67.9%.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.5
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• pp.617-623
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• 2008

A fine-mapping method exploiting linkage disequilibrium was used to detect quantitative trait loci (QTL) on the X chromosome affecting milk production, body conformation and productivity traits. The pedigree comprised 22 paternal half-sib families of Black-and-White Holstein bulls in the Netherlands in a grand-daughter design for a total of 955 sons. Twenty-five microsatellite markers were genotyped to construct a linkage map on the chromosome X spanning 170 Haldane cM with an average inter-marker distance of 7.1 cM. A covariance matrix including elements about identical-by-descent probabilities between haplotypes regarding QTL allele effects was incorporated into the animal model, and a restricted maximum-likelihood method was applied for the presence of QTL using the LDVCM program. Significance thresholds were obtained by permuting haplotypes to phenotypes and by using a false discovery rate procedure. Seven QTL responsible for conformation types (teat length, rump width, rear leg set, angularity and fore udder attachment), behavior (temperament) and a mixture of production and health (durable prestation) were detected at the suggestive level. Some QTL affecting teat length, rump width, durable prestation and rear leg set had small numbers of haplotype clusters, which may indicate good classification of alleles for causal genes or markers that are tightly associated with the causal mutation. However, higher maker density is required to better refine the QTL position and to better characterize functionally distinct haplotypes which will provide information to find causal genes for the traits.

• Ocean Systems Engineering
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• v.5 no.4
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• pp.279-299
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• 2015

Suction anchors are widely adopted and play an important role in mooring systems. However, how to reliably predict the failure mode and ultimate pullout capacity of the anchor in sand, especially by an easy-to-use theoretical method, is still a great challenge. Existing methods for predicting the inclined pullout capacity of suction anchors in sand are mainly based on experiments or finite element analysis. In the present work, based on a rational mechanical model for suction anchors and the failure mechanism of the anchor in the seabed, an analytical model is developed which can predict the failure mode and ultimate pullout capacity of suction anchors in sand under inclined loading. Detailed parametric analysis is performed to explore the effects of different parameters on the failure mode and ultimate pullout capacity of the anchor. To examine the present model, the results from experiments and finite element analysis are employed to compare with the theoretical predictions, and a general agreement is obtained. An analytical method that can evaluate the optimal position of the attachment point is also proposed in the present study. The present work demonstrates that the failure mode and pullout capacity of suction anchors in sand can be easily and reasonably predicted by the theoretical model, which might be a useful supplement to the experimental and numerical methods in analyzing the behavior of suction anchors.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.10a
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• pp.35.2-35.2
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• 2011

In this study, hyaluronic acid (HyA) - Gelatin (Gel) hydrogels were prepared at ratio of 15:85 with the goal of obtaining a high uniform porosity and porous biocompatibility scaffold for bone tissue engineering applications. In order to develop a proper scaffold for bone implant application, a HyA-Gel hydrogel loaded in sponge Biphasic Calcium Phosphate (BCP) was prepared. To assay the cytocompatibility and cell behavior on the HyA-Gel hydrogel and HyA-Gel/BCP scaffold, cell attachment and spreading of MSCs seeded on the scaffolds were studied. An invivo study was performed for HyA-Gel/BCP scaffolds after 1 and 3 months implantation. Our results provide a novel and simple method to obtain an adequate scaffold for osteoblast cells and indicate that HyA-Gel hydrogel and HyA-Gel/BCP scaffold could be a good candidate for bone tissue engineering scaffolds.