• Journal of the Korean housing association
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• v.13 no.2
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• pp.79-86
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• 2002

The purpose of this study was to provide guidelines for the remodeling understanding the needs of apartment housing residents. In order to achieve our goal, questionnaire surveys were used. We sampled the questionnaire surveys of the households in Seoul whose apartments had been more than ten years and recently remodeled. The materials collected by a questionnaire survey were analyzed by examining the frequency, percentage on the SPSS/PC+ Statistics package. The results of the questionnaire survey were as follows: (1) Residents tend to demand better environment than an economics benefits from remodeling. (2) Residents wanted to have organized the remodeling group that can help to solve the problems concerning profit and loss among residents. (3) Residents wanted to be supported by government, expand loans from monetary organizations, and have a reserve fund for the remodeling.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2011.04a
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• pp.167-171
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• 2011

Managing apartments is critical not only to handling the physical deterioration over time, but also to the quality of community life, social environment and ultimately residents' satisfaction with the housing environment. Therefore, this study aims at understanding residents' awareness of apartment management, and finding the relationship between management activities and residents' satisfaction and participation by comparing an apartment with active management and an apartment without it. This study examines 1) management activities of two subject apartment complexes, and 2) how management activities affect residents' participation and satisfaction. Surveys were conducted of the residents, and SPSS statistics package was utilized to analyze the survey data. This study found that management activities of apartment complex have positive influence on residents' participation and satisfaction with their housing environment. The results of this study can be utilized as basic materials to develop effective guidelines and manual from the perspective of environmental management of apartment houses, in order to improve the participation of the residents in the apartment management.

• Transactions on Electrical and Electronic Materials
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• v.15 no.4
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• pp.221-225
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• 2014

Although gold wire bonding techniques have already matured in semiconductor manufacturing, weakly bonded wires in semiconductor chip assembly can jeopardize the reliability of the final product. In this paper, weakly bonded or failed aluminum bonding pads are analyzed using X-ray photoelectron spectroscopy (XPS), Auger electron Spectroscopy (AES), and energy dispersive X-ray analysis (EDX) to investigate potential contaminants on the bond pad. We found the source of contaminants is related to the dry etching process in the previous manufacturing step, and fluorocarbon plasma etching of a passivation layer showed meaningful evidence of the formation of fluorinated by-products of $AlF_x$ on the bond pads. Surface analysis of the contaminated aluminum layer revealed the presence of fluorinated compounds $AlOF_x$, $Al(OF)_x$, $Al(OH)_x$, and $CF_x$.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.584-589
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• 2007

Polyvinylidene fluoride (PVDF) is a type of electroactive polymer which shows significant shape change when exposed to electric field. PVDF is generally used as a film sensor in non-destructive evaluation (NDE) of materials. In this study, however, its properties relevant to film actuator are considered. Since most of the electromechanical applications that use PVDF and its copolymers as actuators use their piezoelectric properties, only the piezoelectric properties of PVDF are discussed here. These properties depend mainly on the degree of crystallinity of PVDF. Available data from recent research publications are used to simulate the response of a PVDF bimorph beam on the application of electric field, by a commercial finite element analysis package ANSYS. Finally, the factors that affect mechanical behavior of PVDF bimorph beam are discussed.

• Journal of the Korean Society of Industry Convergence
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• v.3 no.1
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• pp.69-75
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• 2000

Multichip packages are comprised of dissimilar materials which expand at different rates on heating. The differential expansion must be accommodated by the various structural elements of the package. A types of heat exposures occur operation cycles. This study presents a finite element analysis simulation of flip-chip among multichip. The effects of geometries and material properties on the reliability were estimated during the analysis of temperature and thermal stress of flip-chip. From the results, it could be obtained that the more significant parameters to the reliability of flip-chip arc chip power cycle, heat convection and height of solder bump.

• Structural Engineering and Mechanics
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• v.43 no.4
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• pp.439-448
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• 2012

This paper investigates the load sharing of double circular arc helical gears considering the influence of assembly errors. Based on a load sharing formulae, a three-dimensional finite element tooth contact analysis (TCA) is implemented with commercial software package ANSYS. The finite element grid for the double circular arc gear contact model is automatically generated by using the APDL (ANSYS Parameter Design Language) embedded in ANSYS. The realistic rotation of gears is achieved by using a coupling degree-of-freedom method. Numerical simulations are carried out to exemplify the proposed approach. The distribution of contact stress and bending stress under specific loading conditions are computed and compared with those obtained from Hertz contact theory and empirical formulae to demonstrate the efficiency of the proposed load sharing calculation formulae and TCA approach.

• 연구논문집
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• s.34
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• pp.87-99
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• 2004

A spring tension control device is used as a very important part of an twister system. The friction force of tensioner must keep same friction force during winding in package. For satisfy this function, many device used common compression coil spring. In this paper, by using the case-building technique which was based on simple theory that unknown design variables are induced by given input design variables by the designer, design automation algorithm about rectangular section compression springs with elastic characteristic is developed. Four design equation are justified in using of analysis of torsion of straight bar of rectangular section and geometrical condition of coil spring. Four design equation and nine design variables are computed by case-building technique.

• Journal of Welding and Joining
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• v.33 no.3
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• pp.32-39
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• 2015

With the simplicity of process and high reliability in chip or package bonding, epoxy solder paste (ESP) has been recently considered as a competitive bonding material. The ESP material is composed of solder powder and epoxy formulation which can remove oxide layers on the surface of solder powder and pad finish metal. The bonding formed using ESP shows outstanding bonding strength and suppresses electrical short between adjacent pads or leads owing to the reinforced structure by cured epoxy after the bonding. ESP is also expected to suppress the formation and growth of whisker on the pads or leads. With the mentioned advantages, ESP is anticipated to become a spotlighted bonding material in the assembly of flexible electronics and electronic modules in automotive vehicles.

• Transactions of Materials Processing
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• v.10 no.6
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• pp.493-499
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• 2001

An optimal robust design methodology has been developed to minimize warpage in injection-molded pats. The response surface methodology was applied to obtain a functional relationship between design variables and warpage value, and the modified complex method was used as an optimization tool to search for an optimal design solution over prescribed design region. To attain robustness against process variations, Taguchi's SN ratio was introduced as the design metric. The proposed optimal design procedure was applied to an actual part, the Guide-ASF model of a fax machine, and the usefulness of the methodology was shown through the CAE simulation using a commercial injection molding software package.

• The Research Journal of the Costume Culture
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• v.12 no.3
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• pp.379-391
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• 2004

The purpose of this study was to examine the effects of uniform's color and motif on nurse's impression formation. The experimental design was 5×3×2(uniform color×motif ×perceiver's gender) factorial design with a between-subjects design. The experimental materials developed for the study were a set of stimuli and a response scale. The subjects were 738 undergraduate students of Daejon and Chungnam province. The SPSS package was used for data analysis which includes factor analysis, two-way ANOVA, Duncan's multiple range test, and Cronbach's α to measure the reliability. Results were as follows; The image or the stimulus was consisted of the 4 different dimensions(evaluation, sociability, ability, potency). All the independent variables showed some significant impression effects on selected dimensions. The motif and perceiver's gender also showed significant main effects as well as some interaction effects with the color variable on some selected impression dimension and the impression effects of the three variables in relationship to perceiving nurses' images. On a conclusion, these results supported the Gestalt theory.