• Korean Journal of Human Ecology
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• v.17 no.4
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• pp.563-574
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• 2008

This study investigated the effects of the adolescents' attachments to parents, teachers, and friends on delinquencies. Participants were 3449 adolescents in middle and high school (2003-2006 panel 1 in Korea Youth Panel Survey). For analyses of research questions, frequencies, descriptive statistics, independent sample t-test, Pearson correlations and multiple regression were used. The results were as follows: For males, attachment to parents most influenced delinquencies in middle school but attachment to friends most influenced delinquencies in high school, however, for females, attachment to parents most influenced delinquencies in middle school and high school. Attachments to parents and teachers influenced delinquencies negatively, however, attachments to friends influenced delinquencies positively.

• Journal of Families and Better Life
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• v.26 no.4
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• pp.27-40
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• 2008

The purpose of this study was to investigate the effects of attachments to parents, teachers, and friends on delinquencies among elementary school students. Participants were 2844 elementary school students from the 2004-2006 panel 2 data of the Korea Youth Panel Survey(KYPS). For analyses of research questions, frequencies, descriptive statistics, independent sample t-tests, Pearson correlations and multiple regression analysis were used with SPSS 12.0. Results of the study indicated that : (1) For boys, attachments to parents reduced delinquencies more than for girls. However, for girls, attachments to teachers reduced delinquencies more than for boys. (2) Attachments to friends influenced delinquencies negatively in the 4th grade, but influenced delinquencies positively in the 6th grade. (3) When boys and girls kept in touch with delinquent peers, attachments to parents largely influenced delinquencies.

• The Journal of Advanced Prosthodontics
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• v.8 no.1
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• pp.9-15
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• 2016

PURPOSE. Although magnetic attachment is used frequently for overdenture, it is reported that attractive force can be decreased by abrasion and corrosion. The purpose of this study was to establish the clinical basis about considerations and long term prognosis of overdenture using magnetic attachments by investigating the change in attractive force of magnetic attachment applied to the patients. MATERIALS AND METHODS. Among the patients treated with overdenture using magnetic attachments in Dankook University Dental Hospital, attractive force records of 61 magnetic attachments of 20 subjects who re-visited from July 2013 to June 2014 were analyzed. Dental magnet tester (Aichi Micro Intelligent Co., Aichi, Japan) was used for measurement. The magnetic attachments used in this study were Magfit IP-B Flat, Magfit DX400, Magfit DX600 and Magfit DX800 (Aichi Steel Co., Aichi, Japan) filled with Neodymium (NdFeB), a rare-earth magnet. RESULTS. Reduction ratio of attractive force had no significant correlation with conditional variables to which attachments were applied, and was higher when the maintenance period was longer (P<.05, r=.361). Reduction ratio of attractive force was significantly higher in the subject group in which attachments were used over 9 years than within 9 years (P<.05). Furthermore, 16.39% of total magnetic attachments showed detachment of keeper or assembly. CONCLUSION. Attractive force of magnetic attachment is maintained regardless of conditional variables and reduction ratio increased as the maintenance period became longer. Further study on adhesive material, attachment method and design improvement to prevent detachment of magnetic attachment is needed.

• Korean Journal of Child Studies
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• v.26 no.1
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• pp.137-154
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• 2005

The socio-emotional behaviors of 2-year-olds were examined by multiple attachments to mothers and child care providers in the context of home and child care centers. Participants were 100 children (mean age: 30.2 months), their mothers, and 27 child care providers. Attachment security was assessed with attachment Q-set. Children's social interaction with peers and teachers were rated every 10 seconds during 10 minute observation periods for 4 days, totaling40 minutes per child. Mothers and child care providers completed the Infant Toddler Socio-Emotional Assessment (ITSEA). Results showed that secure attachment relationships with child care providers partly compensated for insecure attachments with mothers at home. In the context of the child care center, secure attachments with child care providers were more important determinants of the development of socio-emotional behaviors than secure attachments with mothers.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.349-353
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• 2007

The main functions of excavator are mainly carried out by excavator attachments such as arm and boom. These components should be designed to be light as well as durable enough because their effects on the whole structure are significant. In this paper, an optimization procedure for lightweight design considering fatigue strength for excavator attachments is presented. The weight of attachments and allowable fatigue stresses at critical areas are used as objective function and constraints, respectively, in which design variables are the thickness of the plates of attachments. The simulated annealing search method is adopted for a global optimization solution. Besides, the response surface method using the artificial neural network is used to simulate constraint function for the sake of practical fast calculation. Some example case of optimization is presented here for a sample excavator. This weight optimization is expected to contribute to a considerable improvement of fuel efficiency of excavator.

• The Journal of Advanced Prosthodontics
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• v.7 no.1
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• pp.32-38
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• 2015

PURPOSE. The aim of this study was to compare the durability and retention of 4 types of attachments placed over computer aided design/computer aided manufacturing (CAD/CAM) titanium bars when subjected to different pH conditions. MATERIALS AND METHODS. Four commercially available attachments were investigated: Hader Yellow, Hader Red, Ackerman Gold and Ackerman Stainless Steel. These attachments and Ackerman CAD/CAM titanium bars were placed in 2 vessels containing different artificial saliva solutions (pH 7/pH 4) at $37^{\circ}C$ for one month to simulate corrosion conditions, and they were then subjected to mechanical testing (5400 cycles of insertion and removal). RESULTS. The results revealed that there were significant differences in the average values of insertion/removal force due to the pH (F (1, 24)=9.207, P<.05) and the type of attachment (F (3, 24)=11.742, P<.05). CONCLUSION. More acidic pH values were found to have a negative influence on the retention capacity of the attachments.

• Design & Manufacturing
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• v.15 no.1
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• pp.8-13
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• 2021

Excavators are construction machines used for digging soil, transporting soil, dismantling buildings and clearing the ground at construction sites. There are various attachments attached to the arm end of the excavator and used for various operations. There are the most common types of buckets attached for excavation and other types of attachments used for foresting, road cleaning, snow removal, and waste disposal. When multiple types of work are done at the same time, several attachments must be replaced and a device called a quick coupler is used to reduce replacement time. Although a quick coupler reduces the replacement time of the Attachment, it is necessary to attach safety devices to prevent unintentional detachment of attached attachments during the operation. To prevent the attachment from leaving or falling regardless of the operator's intention, support is installed in the hook of the bucket pin and controlled through a separate hydraulic cylinder to ensure safety. When attaching an attachment, it shall be attached without any action. This study is intended to verify the design validity of safety devices to prevent falls of attachments occurring at construction sites.

• Korean Journal of Child Studies
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• v.31 no.5
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• pp.1-15
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• 2010

The purpose of study was to investigate internal and external problem behavior according to types of multiple-attachments exhibited to both mothers and teachers. The subjects were 120 preschool children (between 4 to, -5 years old), their mothers and teachers. The attachment classification of these 120 preschoolers was evaluated by an attachment Q-set. Data was statistically analyzed by means of one-way ANOVA, and the Duncan test with the SPSS Win 13.0 program. Our results were as follows, Firstly, significant differences were observed in the internal problem behavior according to types of multiple-attachments. Second, significant differences were also observed in the external problem behavior according to types of multiple-attachments. This study suggests that secure attachment relationships with teachers may compensate for insecure relationships with mothers.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.477-482
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• 2001

A study was performed to determine the optimum height for an arc air gouging of temporary attachments, which were attached at the pressure vessel made of low alloy steel. Frequently, the crack occurred in the base metal by the excessive heat input during an arc air gouging process to remove the temporary attachments. A numerical analysis by 2-dimensional finite element method was performed to calculate the temperature distribution in the base metal during the removal of temporary attachments. And then the mock-up test was performed to verify the numerical results. Numerical values showed good agreement with the experimental results. These results indicated that the defects due to the excessive heat input during an arc air gouging were dependent on the height of temporary attachments remained above hie main products.

• Selected Papers of The Society of Naval Architects of Korea
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• v.1 no.1
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• pp.52-64
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• 1993

There exist many frame structural systems having some attachments reducible to damped spring-mass systems, concentracted masses and spring supports. For free and forced vibration analyses of such a system an analytical method based on the receptance method is presented. A framed structure having attachments is considered as a combined system composed of various Timoshenko beam and bar elements and the attachments. So, the vibration characteristics of the system are calculated by synthesizing receptances and Support Displacement Transfer Ratio (SDTR) of beam and bar elements In spectral and/or closed forms, and receptances of the attachments. In forced vibration analysis, arbitrary excitation forces at a point on the structure and displacement excitations at boundaries are considered. Numerical investigations are carried out for verification of the presented method, and the results show good accuracy and very high computational efficiency.