• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.2
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• pp.143-148
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• 2016

A micro end mill is one of the precise tools used in machining ultra-precision products such as microchannel and micropatterned mold. To achieve the required precision of these products, several studies investigated the cutting force, burr formation, and burr generation mechanism of micro end mills; however, there are few studies on the alignment of micro tools, which is the foundation of machining. Hence, in this investigation, relation expressions were derived to determine the relation between the misalignment parameters and the machining accuracy. At the same time, the effect of the machining parameters was analyzed using a multiple linear regression analysis and the analysis of variance. The results indicate that the tilting angle of a micro tool has more influence on the machining accuracy than other parameters.

• Journal of Plant Biology
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• v.19 no.2
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• pp.37-40
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• 1976

The experiment designed to obtain information relative to the favourable levels to apply N.P.K fertilizer was conducted at the hop garden of College of Agriculture, S.N.U. in 1975. The varieties used were 1-year-old Cascade, Hallertau and Shinshuwase. The design of the experiment was a split plot design with 3 replications. Yields were recorded as fresh weight of harvested cones in gram per split plot. The results obtained from the experiment were as follows: 1. The results from analysis of the data for 3 varieties indicated that significant increase in yield were found due to the application of 46g N, 20g P2O5 and 60kg K2O per plant, although higher level thn the above caused a remarkable reduction of yield. 2. The individual fresh weight of harvested cones was significantly increased with application of nitrogen, phosphorus and potash, regardless of fertilizer levels. 3. Analysis of variance for yields showed that there were no significant interaction between fertilizer level and variety, i.e., all varieties used might require the same fertilizer level.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.22 no.4
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• pp.56-64
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• 2014

There were a total of 65 accidents of helicopers between 1990 and 2013. The overall accidents rate has remained around 8 accidents per 100,000 flight hours, and the fatal rate has stayed at about 8 accidents per 100,000 flight hours. In this study, we conduct a series of statistical analyses to investigate the significance of latent failure of groups that operate the helicopter. Analysis of variance demonstrated significant differences in the latent condition score for the 3 groups, with the lower accidents rate groups reporting better scores of latent condition. Results indicated that there are the significant differences of latent condition in accidents between groups of high accidents rate and groups of low accidents rate.

• Journal of Fashion Business
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• v.9 no.6
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• pp.117-125
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• 2005

Felt fabric is one of the nonwovens characterized by the entanglement of the constituent fibers, resulting from the application of heat, moisture, and mechanical action to a fibrous web. This method has been applied to the wool fibers for long. As a natural dyestuff, cochineal dyestuff was employed for dyeing felt specimens. The color of the dyed felt was measured using a colorimeter. Along with this, an attempt was made in order to evaluate the variance of the color of the felted specimens having irregular orientation of wool fibers.

• Structural Engineering and Mechanics
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• v.3 no.3
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• pp.273-287
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• 1995

Stochastic response of systems to random excitation can be estimated by direct integration methods in the time domain such as the stochastic central difference method (SCDM). In this paper, the SCDM is applied to compute the variance and covariance in response of linear and nonlinear structures subjected to random excitation. The accuracy of the SCDM is assessed using two-DOF systems with both deterministic and random material properties excited by white noise. For the former case, closed-form solutions can be obtained. Numerical results also are presented for a simply supported geometrically nonlinear beam. The stiffness of this beam is modeled as a random field, and the beam is idealized by the stochastic finite element method. A perturbation technique is applied to formulate the equations of motion of the system, and the dynamic structural response statistics are obtained in a time domain analysis. The effect of variations in structural parameters and the numerical stability of the SCDM also are examined.

• Korean Journal of Child Studies
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• v.17 no.1
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• pp.245-258
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• 1996

The purpose of this study was to examine the relationship between mother's parenting stress and child's temperament, mother's temperament, and poorness-of-fit. The subjects were 236 mothers of 4- to 6-year-old children in Seoul. Data was analyzed by correlation, analysis of variance, and stepwise regression analysis. Results showed that most poorness-of-fit of emotionality was due child's high-mother's high (CH-MH) and high-low (CH-ML) combination. Most poorness-of-fit (activity as well as sociability) was associated with child's low-mother's low (CL-ML) and low-high (CL-MH) combination. Mothers who had a highly emotional child and who were in poorness-of-fit emotionality perceived more hassles and more intensive daily parenting stress. It was also found that the most significant variable predicting mother's hassles and daily stress intensity was poorness-of-fit of emotionality, followed by mother's emotionality.

• Journal of the Korean housing association
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• v.8 no.2
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• pp.97-106
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• 1997

This study was designed to examine the determinants of housing decisions of prospective home buyers in newly constructed areas in Ulsan. The main focus was to clarify the current mobility motives. reasons for choosing present dwelling, housing values , housing satisfaction, housing Preferences of households. The data used in this study were collected from a probability sample consisting of 350 households, and analyzed through descriptive statistics, factor analysis, and analysis of variance. The major findings were as follows: 1) The motives of current mobility of households were home ownership, larger space, and better neighborhoods. 2) The reasons for choosing present dwelling were location. dwelling size, air quality and housing price. 3) Seventeen items of housing values were identified important. 4) Households were satisfied with dwelling size, number of rooms, views, and neighborhood facilities, 5) Dwelling features preferred by the households were the individual opinion of interior, perfect antinoise, better construction materials, better bath, kitchen facility etc.

• Structural Engineering and Mechanics
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• v.49 no.1
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• pp.41-64
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• 2014

The main objective of this article is the exploitation of a stochastic hybrid mesh-free method based on stochastic generalized finite difference (SGFD), Newmark finite difference (NFD) methods and Monte Carlo simulation for thermoelastic wave propagation and coupled thermoelasticity analysis based on GN theory (without energy dissipation). A thick hollow cylinder with Gaussian uncertainty in mechanical properties is considered as an analyzed domain for the problem. The effects of uncertainty in mechanical properties with various coefficients of variations on thermo-elastic wave propagation are studied in details. Also, the time histories and distribution on thickness of cylinder of maximum, mean and variance values of temperature and radial displacement are studied for various coefficients of variations (COVs).

• Child Health Nursing Research
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• v.9 no.3
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• pp.301-308
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• 2003

The Purpose of this study was to identify factors that influence the self-esteem of the schooler of families in poverty. A descriptive, correlational, and cross-sectional study design was used. The data were collected from February to March, 2001. Convenient sampling was done from 194 subjects living in Jeju Do, but 167 subjects among these were used for the study analysis. Hierarchical Stepwise Regression was used to identify significant factors. The results of this study were as follows: In general, self-esteem status of the schooler in poor families was relatively poor. In stepwise regression analysis, self-esteem status was significantly influenced by emotional home environment, duration of poverty and frequency of parent-child tactics. These variables explained 26.8％ of the variance of schooler's self-esteem. Conclusively, it is recommended that nursing intervention programs for schooler in poor family should be a focus to enhance the economic context as well as family effect.

• Journal of the Semiconductor & Display Technology
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• v.12 no.4
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• pp.9-13
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• 2013

Lapping is a very complicated and random process resulting from the variation of abrasive grains in its sizes and shapes and from the numerous factors having an effect on the process quality. This paper presents a study of a $2^4$ full factorial experimental design and analysis to optimize surface quality in lapping operation. The optimization of the factors to obtain minimum surface roughness was carried out by incorporating effect plots, main effect plots, interaction plots, analysis of variance(ANOVA), surface plots, and contour plots. The statistical design experiments, designed to reduce the total number of experiments required, indicated that, within the selected conditions, all the parameters influenced at a significance level of 5%. In addition, some of the possible interactions between these parameters also influenced the lapping process, especially those that were of third order. A regression model was suggested and fitted the experimental data very well.