박철우 교수

The flow structure around the free end of a finite circular cylinder (FC) embedded in various atmospheric boundary layers (ABLs) was investigated experimentally. The experiments were carried out in a closed-return type subsonic wind tunnel with various oncoming ABLs. A finite circular cylinder with an aspect ratio (L/D) of 6 was mounted vertically on a flat plate. The Reynolds number based on the cylinder diameter is similar to Re = 20, 000. The wake structure behind a cylinder located in a unif

Purpose The purpose of this study is to show effect of entrepreneurship on entrepreneurial intention. Currently, the long-term global economic crisis is accelerating, and the concerns for future uncertainties are spreading throughout our society. The ICT majors in Busan region are no exception so that business start-up is being considered as a new alternative to survive and grow in such uncertain environments at home or abroad. That is, business start-ups and entrepreneurship are being emphasize

Long-range-dependent time series are endemic in the statistical analysis of Internet traffic. The Hurst parameter provides a good summary of important self-similar scaling properties. We compare a number of different Hurst parameter estimation methods and some important variations. This is done in the context of a wide range of simulated, laboratory-generated, and real data sets. Important differences between the methods are highlighted. Deep insights are revealed on how well the laboratory data

In this paper, we extend SiZer (SIgnificant ZERo crossing of the derivatives) to dependent data for the purpose of goodness-of-fit tests for time series models. Dependent SiZer compares the observed data with a specific null model being tested by adjusting the statistical inference using an assumed autocovariance function. This new approach uses a SiZer type visualization to flag statistically significant differences between the data and a given null model. The power of this approach is demonstr

Skin aging is caused by exposure to various external factors. Ultraviolet B (UVB) irradiation induces oxidative stress, photoaging, and inflammation in skin cells. Pinus densiflora Sieb. et Zucc. (red pine) has various antimicrobial and antioxidant activities. However, the anti-inflammatory effects of red pine on skin have rarely been reported. The protective effects of malonic acid (MA) isolated from Pinus densiflora were investigated against UVB-induced damage in an immortalized human keratino

This article concerns testing the equality of multiple curves in a nonparametric regression context. The proposed test forms an ANOVA type test statistic based on kernel smoothing and examines the ratio of between- and within-group variations. The empirical distribution of the test statistic is derived using a permutation test. Unlike traditional kernel smoothing approaches, the test is conducted in scale-space so that it does not require the selection of an optimal smoothing level, but instead

The SiZer methodology proposed by Chaudhuri and Marron (1999) is a valuable tool for conducting exploratory data analysis. Since its inception different versions of SiZer have been proposed in the literature. Most of these SiZer variants are targeting the mean structure of the data, and are incapable of providing any information about the quantile composition of the data. To fill this need, this article proposes a quantile version of SiZer for the regression setting. By inspecting the SiZer maps