• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.11
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• pp.864-868
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• 2010

Among LTCC material for substrate, the crystallized anorthite system was mainly studied as high strength material. However, specific factors that have affected on strength of material were studied insufficiently on anorthite system. In this study, the composition of anorthite glass was Ca-Al-Si-Zn-O. The changes of phase and microstructure were observed with the amount and the particle size of glass and the sintering temperature. It was studied that the factors affected on the strength of material. Phases of anorthite and $ZnAl_2O_4$ were formed with the increase of sintering temperature. The $Al_2O_3$ phase was increased with $Al_2O_3$ amount, acted as filler, and the strength of material is increased with $Al_2O_3$ phase. But phases of anorthite and $ZnAl_2O_4$ didn't affect on the strength of material. In the case of 60 vol% glass amounts and below $3.2\;{\mu}m$ of glass particle size, the strength of material was decreased. It is thought that the decrease of strength was due to non-homogeneous mixing between glass powder and filler.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.4
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• pp.177-183
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• 2015

Incremental sheet metal forming is a manufacturing process to produce thin parts using sheet metals by a series of small incremental deformation. The process rarely needs dedicated dies and molds, thus, preparation time for the process is relatively short as to be compared to conventional metal forming. Spring back in sheet metal working is very common, which causes critical errors in dimensions. Incremental sheet metal forming is not fully investigated yet. Hence, incremental sheet metal forming frequently produces inaccurate parts. This paper proposes a method to minimize dimensional errors to improve shape accuracy of products manufactured by incremental forming. This study conducts experiments using an exclusive incremental forming machine and the material for these experiments are sheets of aluminum AL1015. This research defines a process parameter and selects a few factors for the experiments. The parameters employed in this paper are tool feed rate, tool diameter, step depth, material thickness, forming method, dies applied, and tool path method. In addition, their levels for each factor are determined. The plan of the experiments is designed using orthogonal array $L_8$ ($2^7$) which requires minimum number of experiments. Based on the measurements, dimensional errors are collected both on the tool contacted surfaces and on the non-contacted surfaces. The distances between the formed surfaces and the CAD models are scanned and recorded using a commercial software product. These collected data are statistically analyzed and ANOVAs (analysis of variances) are drawn up. From the ANOVAs, this paper concludes that the process parameters of tool diameter, forming depth, and forming method are the significant factors to reduce the errors on the tool contacted surface. On the other hand, the experimental factors of forming method and dies applied are the significant factors on the non-contacted surface. However, the negative forming method always produces better accuracy than the positive forming method.

• Journal of Korea Water Resources Association
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• v.31 no.5
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• pp.539-552
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• 1998

When the pier is constructed in the cohesive be, the accuracy maynot be obtained because the equation for calculating the scour at piers is based upon the results which are analyzed through the experiments in the non-cohesive bed. In this paper, the variation of the depth of the pier scour occurred by constructing 5 types of pier in the channel having the cohesive material is examined. The experimental results are analyzed based upon Froude numbers and non-dimensional numbers which are indicated as the flow depths compared to the pier width. The results are also compared with the results obtained using the existing pier scour equations. In this paper, the shape factors, which can be used for calculating the scour depth of the pier in the cohesive channel bed, are suggested. The shape factors are indicated through the ratios between the scour depth at the circular pier and the scour depths at the different types of pier, and are suggested as two stages. In the first stage, in which the water depth compared to the pier width is less than 1.2, the shape factors are given as the equations. However, in the second stage the shape factors are given as the constant values. It is understood that the shape factors suggested in this paper can be properly usd for calculating local scour at piers in the bridges which are constructed in the cohesive channel bed having the characteristics of the bed material which is used in these experiments. Keywords : local scour, maximum scour depth, cohesive bed material, pier shape, pier, shape factor.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.3
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• pp.184-191
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• 2000

Properties of pad are investigated to find the relationship between the chemical mechanical polishing(CMP) results, such as material removal rate and within wafer non-uniformity(WIWNU), and its properties. Polishing pressure is considered as important factors to affect the results, so behavior of ordinary polymer is studied to define the polishing result affecting properties of pad. Experimental setup is devised to identify the behavior of pad and several different pads are used in chemical mechanical polishing experiments to verify the correlations between pad properties and polishing results. The results indicate that the viscoelastic properties of pad had relationships with the polishing results, and shows correlation between suggested properties of pad and polishing result.

• Transactions of Materials Processing
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• v.8 no.3
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• pp.245-251
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• 1999

In this study, the experimental considerations of the friction factors are presented in a few cases. The friction factors in the cases of, first, the drawing quality material, SPC3C through the non-coated die of base material. GC30, secondly, SPCC through the Cr-coated GC30 die, and lastly. SPCC through the TD heat treated STD11 die, are measured experimentally both for the increasing die temperature and the blank holding forces. The results show no considerable variations of the value of friction coefficients according to the change of both the die temperature and the die treating conditions.

• Korean Institute of Interior Design Journal
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• no.27
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• pp.35-42
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• 2001

The main scope of this study is to define such system of space composition factor to diversify the interior space of the apartment housing. Staring from the space analysis, identification of the design factors, characters of the anthropometry for the dwelling behavior, and analyzed dimensions of the interior furniture from the market data have uniformly integrated to engage with such system for innovation and diversification of the space design method. The elements of the composition factors are as follows: 1. Structural elements - $\circled1$Bearing wall $\circled2$Ceiling $\circled3$Floor $\circled4$Structural column 2. furniture elements - $\circled1$Fixed furniture $\circled2$Movable furniture $\circled3$Non-bearing wall $\circled4$F1exible wall $\circled5$Void & Solid 3. Finished material elements - $\circled1$Structural material $\circled2$Doub1e shell $\circled3$Color & Tone $\circled4$Lighting system For the design system selected space in restricted in 3way directional axis X,Y,Z to form its volume and direction of the space composition factors. X-axis is stands for horizontal length of the factor, Y-axis is for the space depth, and lastly, Z-axis is for the hieghts of the space based on anthropometris.

• Journal of Korean society of Dental Hygiene
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• v.11 no.4
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• pp.523-532
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• 2011

Objectives : The purpose of this study was to measure the effect of factors analyes the associated by the dental treatment fear of level dental hygiene and non-dental hygiene students, and then to provide basic material which can help to improveoral health and effective dental treatment. Methods : The subject in this study were 275 students in Jeolla region. The data were collected from March through April 2010, by way of the self-reported questionnaire. Results : 1. Subjects, who correspond to 'high fear level' which is more than 60 points in the scale of Dental Fear Survey, were indicated to be larger in collegians of general-related departments(38.9%) than collegians of health-related department(36.3%).2. Among three detailed factors, the treatment-stimulator response factor showed the higher fear sense than other 2 factors. In the physiological response, 'muscular tension' was 2.72 points, there by having been indicated to be the highest.3. The more belonging to the group with high fear was indicated to lead to the more in direct pain experience, in non-anesthesia pain experience, and in indirect pain experience through brothers and sisters. Even the symptom and syndrome in oral disease were indicated to be much. 4. As a result of comparing difference in dental fear level depending on pain experience, it was indicated that the more belonging to the group with high fear leads to the more in direct pain experience, in non-anesthesia pain experience, and in indirect pain experience through brothers and sisters. Conclusions : Dental fear must be controlled carefully in order to promote oral health and effective dental treatment.

• Journal of the Korean Society of Clothing and Textiles
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• v.28 no.5
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• pp.658-667
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• 2004

The purpose of this study was to examine factors affecting compulsive buying behavior purchasing behavior. Four hundred female college students who have purchased fashion products via Internet shopping or TV home shopping were surveyed. For data analysis, descriptive statistics, factor analysis, t-test, and multiple regression analysis were used. As the results, 16.3% of respondents were revealed as compulsive buyers. For materialism instrument, four factors of materialism were found and labeled as 'material'. 'consumption', 'happiness', and 'economic value' factors. Also, two factors of entertainment pursuit were also identified as 'change' and 'adventure' pursuit. There were statistically significant differences between compulsive buyers and non-compulsive buyers in terms of materialism, success, and change pursuit, self-esteem, compensation, impulsive purchasing, and binge eating. Compulsive consumption scores were correlated to higher materialism, compensatory, impulsive purchasing, binge eating, shifting, entertainment pursuit, and lower self-esteem. Also, results of multiple regression revealed that compensatory, binge eating, and happiness pursuit were significantly to related to compulsive buying.

• Coupled systems mechanics
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• v.8 no.5
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• pp.439-457
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• 2019

In this paper, a new application of a four variable refined plate theory to analyze the nonlinear bending of functionally graded plates exposed to thermo-mechanical loadings, is presented. This recent theory is based on the assumption that the transverse displacements consist of bending and shear components in which the bending components do not contribute toward shear forces, and similarly, the shear components do not contribute toward bending moments. The derived transverse shear strains has a quadratic variation across the thickness that satisfies the zero traction boundary conditions on the top and bottom surfaces of the plate without using shear correction factors. The material properties are assumed to vary continuously through the thickness of the plate according to a power-law distribution of the volume fraction of the constituents. The solutions are achieved by minimizing the total potential energy. The non-linear strain-displacement relations in the von Karman sense are used to derive the effect of geometric non-linearity. It is concluded that the proposed theory is accurate and simple in solving the nonlinear bending behavior of functionally graded plates.

• Journal of Mechanical Science and Technology
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• v.20 no.9
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• pp.1428-1435
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• 2006

A slightly curved crack with an eigenstrain is considered. Solutions for a slightly curved crack in a linear isotropic material under asymptotic loading as well as for a slightly curved crack in a linear isotropic material with a concentrated force are obtained from perturbation analyses, which are accurate to the first order of the parameter representing the non-straightness. Stress intensity factors for a slightly curved crack with an eigenstrain are obtained from the perturbation solutions by using a body force analogy. Particular attention is given to the crack path stability under mode I loading. A new parameter of crack path stability is proposed for a crack with an eigenstrain. The path stability of a crack with steady state growth in a transforming material and a ferroelectric material is examined.