• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.5
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• pp.135-141
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• 2021

As a trend of lightening automobiles and electronic products, several studies are currently underway to replace parts of metals with resins. In particular, heterojunctions between metals and resins are now under the spotlight. This study aims to evaluate the variation in bonding strength with process conditions when the polybutylene terephthalate (PBT) polymer is bonded to a specimen of the lightweight 6061 aluminum alloy (AL6061). Conditions of the bonding surface of the AL6061 specimen, the temperature of the injection mold, and the content of the glass fiber were considered to be process variables. Bonded specimens were manufactured for different values of these variables. Bonding strength tests were then performed on these specimens and variations were analyzed in their characteristics corresponding to those of the process conditions. Fractures in these specimens were assessed using scanning electron microscopy (SEM) to assess the fracture surface. This was then used to analyze the fracture shape and determine whether anodizing the specimen led to the development of cracks on the joint surface. Results of the above test indicated that while the surface condition of the specimen and the temperature of the injection mold significantly influenced the strength of bonding, the content of the glass fiber did not.

• Child Health Nursing Research
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• v.16 no.3
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• pp.220-229
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• 2010

Purpose: The purpose of this study was to describe quality of life in school age children and the relationship between quality of life and parenting attitude as perceived by children and parent-child communication pattern. Methods: Data were collected between May 26 and June 3, 2009 using self-report questionnaires from 148 pairs of children and their parents. The children were enrolled in 4th to 6th grades. The questionnaires included the Parental Bonding Instrument (PBI), Parent-Child Communication (PCC) Scale, and Pediatric Quality of Life Inventory (PedsQL). The data were analyzed using the SPSS WIN 17.0 program. Results: The Quality of Life (QOL) score for the children was significantly higher among children reporting higher parental bonding attitude (mother r=.38, father r=.34) and parent-child communication (mother r=.43, father r=.36). Results of multiple regression showed that factors significantly associated with QOL were academic achievement, caregiver available after school, parent-child communication, school satisfaction, relationship with peers, and birth order among siblings. Conclusion: Positive relationships and good communication with parents and satisfaction with school life were important factors associated with quality of life in school age children.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.4
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• pp.717-722
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• 2013

In this study, we investigated the design of a wire wedge bonding ultrasonic tool horn using finite element method (FEM) simulations. The proposed method is based on an initial design estimate obtained by FEM analysis. An ultrasonic excitation causes various vibrations of a transducer horn and capillary. A simulated ultrasonic transducer horn and resonator are then built and characterized experimentally using a laser interferometer and electrical impedance analyzer. The vibration characteristics and resonance frequencies close to the exciting frequency are identified using ANSYS. FEM analysis is developed to predict the resonance frequency of the ultrasonic horn and use it in the optimal design of an ultrasonic horn mode shape.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1996.10b
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• pp.34-44
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• 1996

N-machine produces more than input energy at above 3000 rpm. any space energy is absorbed when the N-machine is rotating at a very high velocity. Laws of electromagnetics verify that normal conduction is due to that electrons moves from one three-dimensional crystallizing ${\pi}-bonding$ orbital to next. The ${\pi}-far$ infrared rays are generated from the resonance and rotation of the electrons on the orbitals of three-dimensional crystallizing ${\pi}-bonding$ atoms. Material in universe is composed of ${\pi}-rays$, which have alternative outward electric field. If the alternative outward electric fields of the ${\pi}-rays$ are resonant each other they make attraction force, which is the gravity. The collection of space energy is due to a attraction force between the radially alternating electric field and the ${\pi}-far$ infrared rays in the space. Electrons flow by absorbed density difference of ${\pi}-far$ infrared rays along a conduction wire, which also verifies that normal electron conduction is due to a flow from one three-dimensional crystallizing ${\pi}-bonding$ orbital to next.

• International Journal of Precision Engineering and Manufacturing
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• v.8 no.1
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• pp.52-58
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• 2007

We propose a new contact detection algorithm for fine pitch wire bonding. Fast and stable contact detection of the z-axis in wire bonding is extremely important to maintain the quality of fine pitch gold wire bonding processes, which use a small pad less than $70{\mu}m$ in diameter. A small perturbation in the contact detection time causes a large difference in the size of the formed squashed ball. The new detection method is based on a statistical approach and designed for a discrete Kalman filter. It is faster and has smaller detection time variations than conventional detection methods. Experimental results are presented to demonstrate the advantages of the proposed algorithm.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.3
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• pp.92-98
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• 2020

In this study, an injection mold with conformal cooling channels was designed and manufactured for use in the production of a thick plastic cosmetic container that required high gloss surfaces. A cooling analysis verified the design of the conformal cooling channel for the cosmetic container, and also showed that the cooling efficiency was superior to that of the straight cooling channel. Slide cores designed with the conformal cooling channel were manufactured using the Layers Parting method and vacuum diffusion bonding. Subsequent test injection and quality inspection showed no problem in the appearance and dimensional accuracy of the produced product. The cycle time for product production was about 110 seconds, sufficient for mass production.

• The Journal of the Korean dental association
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• v.11 no.3
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• pp.171-175
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• 1973

A 9-year-old girl, in good health, presented a horizontal impaction of the upper left central incisor. History revealed that the patient had been involved in a trauma of the maxillary anterior portion during her childhood. This impacted tooth crown, which was exposed surgically, was bonded by plastic attachments of direct bonding system, and was carefully tried to induce on the dental arch. On the process of the orthodontic treatment the tooth was completely induced and in normal alignment on the arch. The treatment result was very satisfactory; color, vitality, and mobility were normal, periodontal support was good and the cosmetic result was excellent.

• Macromolecular Research
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• v.17 no.9
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• pp.631-637
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• 2009

This study examined the unique self-doping behavior of carboxylated polyaniline (PCA). The self-doped PCA was synthesized using an environmentally benign enzymatic polymerization method with cationic surfactants. XPS showed that HCl-doped PCA contained approximately 34% of protonated amines but self-doped PCA contained 9.6% of the doped form of nitrogen at pH 4. FTIR and elemental analysis showed that although the PCA was doped with the proton of strong acids at low pH via the protonation of amines, the self-doping mechanism of PCA at pH > 4 was mainly due to hydrogen bonding between the carboxylic acid group and amine group.

• Journal of Korea Foundry Society
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• v.25 no.3
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• pp.134-141
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• 2005

To overcome the undesirable deformation, peeling off and geometrical restrictions which were mainly caused by differences in thermal expansion coefficients during the cladding of aluminum strip and stainless strip, new processing method based on vacuum die casting is designed and implemented in fabricating Al/Fe-17wt%Cr steel(stainless steel). To increase cast-bonding ability, the surface of Fe-17wt%Cr steel is electrochemically etched to have optimum pit size and density. The optimum conditions to generate best pit are as follows: Solution: 1 M $Fecl_{3}$+1 M Nacl, Addition: $CuCl_{2}+HCl$, Current density: 80 $mA/cm^{2}$, Total current: 400 $coulomb/cm^{2}$, AC frequency :60 Hz.

• Journal of the Korean Society for Nondestructive Testing
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• v.27 no.3
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• pp.268-279
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• 2007

The reliability of cold-bonding repair technique of carbon-fiber reinforced plastics (CFRP) laminates, often used as a temporary repair for the airplane maintenance, has been evaluated during cyclic loading and localized heating by nondestructive methods. Major concern was given to the evolution of damage after repair in the form of delaminations due to localized heating and cyclic loading combined. An area of interest both on the specimen repaired by cold-bonding and the specimen without repair where delaminations were induced by localized heating and cyclic loading was monitored by acoustic emission (AE) testing and further examined by pitch-catch low-frequency bond testing, and pulse-echo high-frequency ultrasonic testing. The results showed that the reliability of cold-bonding repair would be significantly reduced by the localized heating and cyclic loading combined rather than by the cyclic loading only. AE monitoring appeared to be an effective and reliable tool to monitor the integrity of temporarily repaired CFRP laminates in terms of the structural health monitoring (SHM) philosophy.