• Journal of The Korean Astronomical Society
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• v.31 no.2
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• pp.105-108
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• 1998

We have found that the two-point correlation function of the APM clusters of galaxies has an amplitude much higher than that claimed by the APM group. As the richness limit increases from R = 53 to 80, the correlation length increases from 17.5 to 28.9 $h^{-1}Mpc$. This indicates that the richness dependence of the APM cluster correlation function is also much stronger than what the APM group has reported. The richness dependence can be represented by a fitting formula ro = 0.53dc + 0.01, which is consistent with the Bahcall's formula ro = 0.4dc. We have tried to find the possible reason for discrepancies. However, our estimates for the APM cluster correlation function are found to be robust against variation of the method of calculation and of sample definition.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.84-86
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• 2007

Aluminum sheets were asymmetrically cold rolled without lubrication by using different roll velocities of upper and lower rolls in order to intensify the shear deformation. During asymmetrical cold rolling of aluminum sheets, a reduction per a rolling pass, initial sheet thickness, roll diameter, roll velocity ratio were varied to investigate the effect of rolling parameters. The formation of through thickness shear texture was related to the ratio of the contact length between the roll and sample($l_c$) to the sheet thickness(d). The strain states associated with asymmetrical rolling were investigated by the finite element method (FEM) simulation. FEM results indicated that the evolution of deformation texture in a thickness layer is strongly governed by integrated values of strain rates $\dot{\varepsilon}_{13}$ and $\dot{\varepsilon}_{11}$ along the streamline in the roll gap.

• Journal of Families and Better Life
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• v.23 no.3 s.75
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• pp.115-126
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• 2005

The purpose of this study were to analyze the factors that influence the economic outcomes of small self-employed business and the job satisfaction among self-employed workers. A sample of 321 was selected from self-employed workers living in Daegu. For data analysis, multiple regression was used. The major findings were as follows: 1. The self-employed workers' income was affected by their gender, age, perception of present economic status, and working years of business, and amount of capital at the beginning, as well as whether they hired other employees. 2. The factors that influence job satisfaction for self-employed workers were previous experience in self-employed business, level of positive vision with future household economy, level of income, length of working hours per day, and the level of empowerment with their self-employed work.

• Fibers and Polymers
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• v.7 no.4
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• pp.367-371
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• 2006

Thermal properties of copolyetherester/silica nanocomposites were examined by using DSC and TGA. The segmented block copolyetheresters with various hard segment structures and hard segment contents (HSC) were synthesized and their silica nanocomposite films were prepared by solution casting method. The nano-sized fumed silica particles were found to act as a nucleating agent of the copolyetheresters. The nanocomposites always showed reduced degree of supercooling or faster crystallization than the corresponding copolyetheresters. The nanocomposites also showed increased hard segment crystallinity except HSC 35 sample which had short hard segment length. In case of 2GT [poly(ethylene terephthalate)] copolyetheresters, which were not developed commercially because of their low crystallization rate, the hard segment crystallinity increased considerably. The copolyetherester/silica nanocomposites showed better thermal stability than copolyetheresters.

• Journal of Ecology and Environment
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• v.36 no.4
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• pp.315-325
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• 2013

Taxa in the order Chlorococcales inhabiting Hongcheon River, South Korea were collected and identified from December 2011 to September 2012. As a result, nine taxa in the Order Chlorococcales including unrecorded genera Oocystidium and Heleococcus were newly added to the Korean flora: Oocystidium ovale, Heleococcus mucicola, Chlorella mirabilis, Monoraphidium convolutum var. pseudosabulosum, M. minutum, Raphidocelis mucosa, Eutetramorus tetrasporus, Scenedesmus flavescens, and S. multicauda. The morphological characteristics of the nine taxa identified in this study mostly corresponded to already reported characteristics; however, M. minutum had a shorter cell length than the recorded description, Raphidocelis mucosa and S. flavescens were larger than previous descriptions, and Scenedesmus multicauda had larger spines than the cell itself. Eight of the nine taxa were found in planktonic samples, whereas Heleococcus mucicola was found in an epilithic sample. Therefore the Korean order Chlorococcales, including these newly reported ones, totals to 255 species.

• Bulletin of the Society of Naval Architects of Korea
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• v.10 no.1
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• pp.15-20
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• 1973

In this paper, it is desired to show a simplified analytical method in estimating the thermal stresses in the heat affected zone of butt welded joint. A finite strip as shown in Fig.1 is taken as a analytical model for stress analysis. Expressing the temperature distributions by Fourier series, the thermal stresses are obtained. From the numerical sample calculation, the following results can be obtained. (1) Thermal stresses can be estimated by the sujected method. (2) The stress component, which is parallel to the weld direction is the largest stress component in major part of the strip. (3) In obtaining a stress component for the engineering purpose, length of the strip can be treated as five times of the thickness with same degree of convergency.

• Communications for Statistical Applications and Methods
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• v.6 no.3
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• pp.957-966
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• 1999

We evaluate the accuacy and precision of maximum likelihood estimation procedures for infectivity of HIV in partner studies. This is achieved by applying the oricedyre typothetical samples generated by computer. One hundred samples were generated with various combinations of parameters. The estimation procedure was found to be quite accurate. in addition it was found that the power of the test for equality of infectivities for two types of contact depends on sample size and length of observation period but not on the number of observations made on each subject. Tests based on a model for the infectivity had higher power than standard methods for comparing proportions.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.47.2-47.2
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• 2014

Bulges of galaxies are thought to have formed and grown at least in part through galaxy mergers, and thus an accurate derivation of their properties can be an effective course to test/confirm our understanding on their formation and evolution in the standard hierarchical merger paradigm. We have generated a sample of galaxy bulges (n = 15,423) in the nearby (0.005 < z < 0.05) universe from the SDSS DR7 and GALEX GR6plus7 databases and derived their structural and photometric properties by means of SExtractor and GALFIT application. Most notable properties include bulge-to-total luminosity ratio, effective radius, disk scale length, ellipticity, and position angle. The UV properties of the bulges have also been analyzed to infer their recent star formation history. A spectroscopic analysis has been performed using their absorption and emission line strengths measured and released by the OSSY team. We present our preliminary results from our investigation mainly focused on stellar population properties and discuss their implications on the formation of bulges.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.132-137
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• 2000

A complete theoretical treatment of the photothermal displacement technique has been performed for thermal diffusivity measurement in solid materials. The influence of parameters - radius and modulation frequency of pump beam and thickness of material - on the phase lag was studied. The phase decreases up to a certain position, then starts to increase and does have an asymptotic value. The position, where phase has the minimum value, is a function of thermal diffusion length thickness of sample, and radius of pump beam. A new method based on minimum phase lag is described to determine the thermal diffusivity of solid material.

• Journal of the Korean Society of Clothing and Textiles
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• v.43 no.3
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• pp.327-348
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• 2019

Among the many methods to make sustainable garments, convertible garments have the potential to change style and function that allow consumers to keep and use garments longer with the possibility of enhancing sustainability. This research analyzes consumer preferences in changeable design options for convertible dresses and the consumers' influence on environmentally responsible apparel consumption (ERC) behaviors on their preferences regarding changeable design options of dresses, which are popular items. An online survey collected data from a convenient sample of 321 female college students from four universities in the United States. Data were analyzed using IBM SPSS through descriptive analysis, cluster analysis, and independent samples t-test. There were significant differences between high and low ERC groups in design preferences that considered important aspects of purchasing, using convertible dresses, and purchase intentions. Detailed differences among sub-groups were analyzed. Designers are encouraged to make tying/folding/wrapping dresses with changes of size/fit, dress length, or color/pattern. The results are beneficial for apparel designers when developing convertible dresses with the guidance of consumers' design preferences and differences according to ERC levels.