• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2001.04a
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• pp.27-34
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• 2001

The BGA Package has been the area array package of choice for several rears. Recently, the transition has been to finer pitch configuration called Chip Scale Packages (CSP). Several of these package types are available at 0.5 mm pitch, requiring surface mount assemblers to evaluate and optimize various elements of the assembly process. This presentation describes the issues associated with making the transition from BGA to CSP assembly. Areas addressed will include the accuracy of pick and piece equipment, printed wiring board lines and spaces, PWB vias, in-circuit test issues, solder paste printing, moisture related factors, rework and reliability. The transition to 0.5 mm pitch requires careful evaluation of the board design, solder paste selection, stencil design and component placement accuracy. At this pitch, ball and board pad diameters can be as small as 0.25 mm and 0.20 mm respectively. Drilled interstitial vias are no longer possible and higher ball count packages require micro-via board technology. The transition to CSP requires careful evaluation of these issues. Normal paste registration and BGA component tolerances can no longer achieve the required process levels and higher accuracy pick and place machines need to be implemented. This presentation will examine the optimization of these critical assembly operations, contrast the challenges at 0.5 mm and also look at the continuation of the process to incorporate smaller pitch flip chip devices.

• Journal of Korean Physical Therapy Science
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• v.18 no.2
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• pp.17-28
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• 2011

Purpose: The aim of this study was to ascertain the effects of the lower extremity muscle strengthening exercise on balance and ambulation of children with cerebral palsy. Methods: 10 subjects who participated in this research undertook the 12-week the lower extremity muscle strengthening exercise program, which consisted of a series of mat exercises and sling exercises. The statistical significances were examined by using Wilcoxon signed-rank test, a non-parametric test, for evaluating the improvement of balance and ambulation of the subjects. In order to evaluate the correlation among the variables, Pearson's correlation coefficients were also calculated. In all statistical analyses the significance level was selected as ${\alpha}$=0.05. Results: Berg balance scale(BBS) was significantly increased after the intervention(p<.05). Percentage weight bearing(PWB) was decreased after the intervention, but there was no significant difference. Time up and go test(TUG) value was significantly decreased(p<.05). Gait velocities was increased after the intervention, but there was no significance. Stride length, step lengths of the affected side and the sound side were significantly increased after the intervention(p<.05). In the correlation analyses of the measures before the intervention, TUG had significant negative correlation to BBS and gait velocity(p<.05). Stride length, step lengths of the sound side and the affected side had significant positive correlation between themselves(p<.01). In the correlation analyses of the measures after the intervention, TUG had significant negative correlation to BBS and gait velocity(p<.05). BBS revealed significant positive correlations to stride length, step lengths of the sound side and the affected side(p<.05). Stride length, step lengths of the sound side and the affected side had significant positive correlation between themselves(p<.01). Conclusion: Based upon the outcomes as above, it is likely that the muscle strength exercises have substantial effects on balance and ambulation of children with cerebral palsy. Thus various lower extremity muscle strengthening exercise programs are required to be studied and developed in order to contribute to functional improvements of children with cerebral palsy.

• Journal of the Microelectronics and Packaging Society
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• v.8 no.4
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• pp.59-65
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• 2001

Epoxy/$BaTiO_3$composite capacitor films with excellent stability at room temperature, uniform thickness, and electrical properties over a large area ware successfully fabricated. The composite capacitor films with good film formation capability and easy process ability were made from epoxy resin developed for ACF as a matrix and two kinds of $BaTiO_3$powders as fillers to increase the dielectric constant of the composite film. The crystal structure of the powders and its effects on dielectric constant of the films were investigated by X-ray diffraction (XRD). And the optimum amount of dispersant, phosphate ester, was determined by viscosity measurement of suspension. DSC and dielectric property tests were conducted to decide the right curing temperature and the optimum amount of the curing agent. As a result, the capacitors of 7 $\mu \textrm{m}$ thick film with 10 nF/$\textrm{cm}^2$ and low leakage current were successfully demonstrated.

• Korea journal of population studies
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• v.27 no.1
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• pp.1-30
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• 2004

The purpose of this study is to investigate (1) the relationship between gender-role attitude and psychological well-being related to the division of household labor and (2) the effect of congruency between gender-role attitude and the division of household labor on psychological well-being for the elderly. In this study, independent variable is gender-role attitude, mediating variable is the division of household labor and dependent variable is psychological well-being. Psychological well-being consists of depression and happiness. The hypotheses of this study are as follows: 1) Gender-role attitude affects psychological well-being of the elderly. The more egalitarian gender-role attitude, the higher degree of psychological well-being, whereas the more traditional gender-role attitude, the lower degree of psychological well-being. 2) The division of household labor influences psychological well-being of the elderly. The higher degree of division of household labor is likely to show the higher degree of psychological well-being. 3) The congruency between gender-role attitude and the division of household labor affects psychological well-being. As the relationship between gender-role attitude and the division of household labor is more congruent. psychological well-being increases. The results of the study are summarized as follows: 1) There is no relation between gender-role attitude and psychological well-being for the elderly. 2) The division of household labor affects psychological well-being for husband. The higher degree of division of household labor, the higher degree of psychological well-being. The result shows that husbands are involved in household labor involuntarily. 3) Congruency between gender-role attitude and the division of household labor affects psychological well-being. As the relationship between gender-role attitude and the division of household labor is more congruent, the degree of depression decreases. 4) Wives participate in most of household labor. Gender segregation in household labor is found in elderly family. 5) Health, income, network of children or sibling, and community network affect psychological well-being. The healthier, higher income and stronger network are likely to show the higher degree of psychological well-being.