• Steel and Composite Structures
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• v.19 no.3
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• pp.569-583
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• 2015

Recent years, explosive welding structures have been widely used in many engineering fields. The bonding state detection of explosive welding structures is significant to prevent unscheduled failures and even catastrophic accidents. However, this task still faces challenges due to the complexity of the bonding interface. In this paper, a new method called dual-tree complex wavelet transform based permutation entropy (DTCWT-PE) is proposed to detect bonding state of such structures. Benefiting from the complex analytical wavelet function, the dual-tree complex wavelet transform (DTCWT) has better shift invariance and reduced spectral aliasing compared with the traditional wavelet transform. All those characters are good for characterizing the vibration response signals. Furthermore, as a statistical measure, permutation entropy (PE) quantifies the complexity of non-stationary signals through phase space reconstruction, and thus it can be used as a viable tool to detect the change of bonding state. In order to more accurate identification and detection of bonding state, PE values derived from DTCWT coefficients are proposed to extract the state information from the vibration response signal of explosive welding structure, and then the extracted PE values serve as input vectors of support vector machine (SVM) to identify the bonding state of the structure. The experiments on bonding state detection of explosive welding pipes are presented to illustrate the feasibility and effectiveness of the proposed method.

• The korean journal of orthodontics
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• v.3 no.1
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• pp.21-28
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• 1972

저자는 direct bonding system의 pretreatment액 처리후 Epoxy adhesive의 bonding strength의 변화를 측정하기 위해서 발거된 상악 전치 진면 법랑질 표면에 pretreatment액으로서 $65\%$ phosphoric acid를 도포한 실험군과 도포하지 않은 비교군을 비교연구하고 임상에 적용하여 다음과 같은 결과를 얻었다. 1. 법랑질 표면에 pumicing과 $65\%$ phosphoric acid를 도포했을때 joint strength는 현저히 상승했다. 2. Epoxy adhesive의 bonding strength는 plastic attachment를 치아면에 접착유지시키기에 충분하며 임상적으로 이용할 수 있다. 3. Joint area가 클 수록 bonding strength는 증가했다.

• Journal of the Korean Home Economics Association
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• v.49 no.4
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• pp.37-50
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• 2011

The purpose of this study is to examine the relationships between children's roles, parental attachment, teacher's concerns and school adjustment among Children's Alcoholics(COAs). Participants were 2,803 middle and high school students in Seoul. The regression analysis results showed that hero role was positively associated with school bonding and academic performance but increased the level of anxiety/depression. Meanwhile, scapegoat and lost children's roles were negatively associated with school bonding and also increased the level of anxiety/depression. Mascot role were positively associated with school bonding and academic performance but had no relation with anxiety/depression. Regarding moderating effects, maternal attachment moderated the relationship between scapegoat role and school bonding while teacher's concerns moderated the relationship between hero role and anxiety/depression, and the relationship between scapegoat role and anxiety/depression. These findings suggested that practitioners need to consider the contributions of children's roles on school adjustment and moderating effects of maternal attachment or teacher's concerns when intervention programs are developed to improve school adjustment among COAs.

• Journal of the Microelectronics and Packaging Society
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• v.27 no.1
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• pp.17-24
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• 2020

As an interconnect scaling faces a technical bottleneck, the device stacking technologies have been developed for miniaturization, low cost and high performance. To manufacture a stacked device structure, a vertical interconnect becomes a key process to enable signal and power integrities. Most bonding materials used in stacked structures are currently solder or Cu pillar with Sn cap, but copper is emerging as the most important bonding material due to fine-pitch patternability and high electrical performance. Copper bonding has advantages such as CMOS compatible process, high electrical and thermal conductivities, and excellent mechanical integrity, but it has major disadvantages of high bonding temperature, quick oxidation, and planarization requirement. There are many copper bonding processes such as dielectric bonding, copper direct bonding, copper-oxide hybrid bonding, copper-polymer hybrid bonding, etc.. As copper bonding evolves, copper-oxide hybrid bonding is considered as the most promising bonding process for vertically stacked device structure. This paper reviews current research trends of copper bonding focusing on the key process of Cu-SiO₂ hybrid bonding.

• Journal of Periodontal and Implant Science
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• v.28 no.1
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• pp.177-185
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• 1998

Periodontal disease and/or loss of teeth brings pathologic tooth migration that can result in esthetic and occlusal problems. Diastema and general spacing of the teeth, particularly in the anterior segments of the dentition are frequently developed in individuals with advanced periodontal disease. Thus, the overall treatment plan for a patent with advanced periodontal disease often involves periodontal orthodontic combined therapy. Orthodontic treatment in adults with periodontal disease is restricted to tooth alignment with special caution. Indirect bonding can achieve accurate bracket placement. A 38 year old woman with adult periodontitis was treated by periodontal therapy. Subsequently, her diastema was orthodontically corrected by indirect bonding technique. It must be an appropriate case report of periodontal-orthodontic combined therapy.

• Journal of the Microelectronics and Packaging Society
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• v.20 no.2
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• pp.17-22
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• 2013

We investigated the optimum bonding conditions for thermo-compression bonding of electrodes between flexible printed circuit board(FPCB) and rigid printed circuit board(RPCB) with Sn-58Bi solder as interlayer. In order to figure out the optimum bonding conditions, peel test of FPCB/RPCB joint was conducted. The peel strength was affected by the bonding conditions, such as temperature and time. The fracture energies were calculated through F-x (Force-displacement) curve during peel test and the relationships between bonding conditions and fracture behaviors were investigated. The optimum condition for the thermo-compression bonding with Sn-58Bi solder was found to be temperature of $195^{\circ}C$ and time of 7 s.

• Journal of the Korean Society for Advanced Composite Structures
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• v.6 no.4
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• pp.30-37
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• 2015

iFLASH System is new structural floor system which consists of sandwich panels filled with nano-composite. The nano-composite has low specific gravity and high bonding strength with steel plates. The bonding strength is one of important factors for structural performance of iFLASH System and it can further be improved by surface preparation such as blast metal cleaning. However, using none blast steel plates is recommended since surface preparation generates additional fabrication time and cost. In this study, a bonding strength test and bending experiment were conducted to check feasibility of applying none blast steel plates to iFLASH System. Moreover, stress in bonding plane between steel plates and nano-composite was analytically evaluated by finite element method. Consequently, flexural capacity of the specimen was 11% higher than theoretically calibrated value and its flexural behavior was structurally efficient without defect of bonding.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.393-397
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• 2005

A process map has been developed, which can identify the process conditions for weak mechanical bonding at the contact surface during the direct extrusion of a Cu-Ti bimetal wire bundle. Bonding mechanism between Cu and Ti is assumed as a cold pressure welding. Then, the plastic deformation at the contact zone causes mechanical bonding and a new bonding criterion fur pressure welding is developed as a function of the principal stretch ratio and normal pressure at the contact surface by analyzing micro local extrusion at the contact zone. The averaged deformation behavior of Cu-Ti bimetal wire is adopted as a constitutive behavior at a material point in the finite element analysis of Cu-Ti wire bundle extrusion. Various process conditions for bundle extrusions are examined. The deformation histories at the three points, near the surface, in the middle and near the center, in the cross section of a bundle are traced and the proposed new bonding criterion is applied to predict whether the mechanical bonding at the Cu-Ti contact surface happens. Finally, a process map for the direct extrusion of Cu-Ti bimetal wire bundle is proposed.

• Korean Journal of Social Welfare
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• v.66 no.2
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• pp.75-99
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• 2014

The purpose of this study is to examine mediation role of parental attachment, school bonding and delinquent peers in effects of child abuse experience on offending school violence among middle school students. The survey was conducted for boys and girls enrolled in 50 middle schools located in Seoul and Kyung-ki province from October 15 to November 25 in 2012 and total 1,563 were used for final analysis. PASW 18.0, AMOS 18.0 and Mplus were used for statistical analysis. Major findings of this study are as follows. Child abuse experience is analyzed as effecting directly to offending in school violence but also having indirect effecting through mediation process with parental attachment, school bonding and delinquent peers from the analysis of structural equation model. Another finding indicates that multiple indirect effects of parental attachment, school bonding, delinquent peers through Mplus nonlinear analysis, pathways including mediator of parental attachment, school bonding and delinquent peers are verified as statistically significance. Below is discussed for practical and policy implications to prevent school violence in middle school based on this study.

• Bulletin of the Korean Chemical Society
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• v.24 no.5
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• pp.545-546
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• 2003