• Journal of Korean Society for Quality Management
• /
• v.32 no.2
• /
• pp.24-36
• /
• 2004

In order for electronic commerce to be successful, it must have a theoretical framework that considers the characteristics of the internet user who are consumers in the cyber space and impacts their purchase intentions. We were able to obtain participations of 316 people, and derived statistics by means of SPSS/PC version 10.0 and Amos 4.0 statistics package. We found that, the higher the degree of skill and the sense of challenge, the level of involvement and perceived service quality increased. And the degree of skill has a negative influence on awareness of perceived risk than the sense of challenge. Perceived service quality, perceived risk and involvement has a influence on purchase intentions.

• Wind and Structures
• /
• v.6 no.5
• /
• pp.357-386
• /
• 2003

A number of methods based on various ideas have been proposed for simulating the non-Gaussian stationary process. However, these methods have some limitations. This paper reviewed several simulation methods based on the translation method using logarithmic and polynomial functions, which have emerged in the history of statistics and in the field of civil engineering. The applicability of each method is discussed from the viewpoint of the reproducibility of higher order statistics of the object function in the simulated sample functions, and examined using pressure signals measured from wind tunnel experiments for various shapes of buildings. The parameter estimation methods, i.e. the method of moments and quantile plot, are also reviewed, and the useful aspects of each method are discussed. Additionally, a simple worksheet for parameter estimation is derived based on the method of moment for practical application, and the accuracy is discussed comparing with a set of previously proposed formulae.

• Annual Conference of KIPS
• /
• 2003.05a
• /
• pp.579-582
• /
• 2003

생체인식을 통한 개인 식별은 새로이 등장한 개념이 아니라 오래 전부터 사용되어왔으나 기존의 화상처리 방법으로는 불필요한 정보까지 포함하여 특징을 추출하여 많은 시간이 소용된다는 문제점이 있었다. 본 논문에서 적용한 고차 국소 자동 상관계수 특징 알고리즘을 이용하여 홍채병변 인식의 수렴속도를 빠르게 하는 신경망을 사용하였으며, 고차 국소 자동 상관계수 특징 알고리즘은 평균 32.5회때 수렴 평균 31.5회때 수렴하였고, 일반 BP 알고리즘은 평균 720.3회때 수렴함과 병변 추출면에서 훨씬 우수함을 보였다.

• The Bulletin of The Korean Astronomical Society
• /
• v.44 no.1
• /
• pp.79.1-79.1
• /
• 2019

We present an algorithm for the fast computation of the general N-point spatial correlation functions of any discrete point set embedded within an Euclidean space of ${\mathbb{R}}n$. Utilizing the concepts of kd-trees and graph databases, we describe how to count all possible N-tuples in binned configurations within a given length scale, e.g. all pairs of points or all triplets of points with side lengths < rmax. Through benchmarking we show the computational advantage of our new graph-based algorithm over more traditional methods. We show that all 3-point configurations up to and beyond the Baryon Acoustic Oscillation scale (~200 Mpc in physical units) can be performed on current Sloan Digital Sky Survey (SDSS) data in reasonable time. Finally we present the first measurements of the 4-point correlation function of ~0.5 million SDSS galaxies over the redshift range 0.43< z <0.7. We present the publicly available code GRAMSCI (GRAph Made Statistics for Cosmological Information; bitbucket.org/csabiu/gramsci), under a GNU General Public License.

• Communications for Statistical Applications and Methods
• /
• v.27 no.6
• /
• pp.641-647
• /
• 2020

The 2 × 3 crossover design, a modified version of the 3 × 3 crossover design, is considered to compare the bioavailability of two generic candidates with a reference drug. The 2 × 3 crossover design is more economically favorable due to decrease in the number of sequences, rather than conducting a 3×3 crossover trial or two separate 2 × 2 crossover trials. However, when using a higher-order crossover trial, the risk of drop-outs and withdrawals of subjects increases, so the suitable statistical inferences for missing data is needed. The bioequivalence model of a of 2×3 crossover trial with missing data is defined and the statistical procedures of assessing bioequivalence is proposed. An illustrated example of the 2 × 3 trial with missing data is also presented with discussion.

• The Journal of Korean Society for School & Community Health Education
• /
• v.3
• /
• pp.1-13
• /
• 2002

Female university students generally have a lower intake of nutrition compared to other age groups due to their adverse interests in their appearance. Drinking, smoking, too much weight control, accumulation of psychological and physical stress are causes of inadequate diet. The result is deterioration of hair health. Establishment of good diet and hair care is the foundation of a healthy hair in adulthood. For this reason, there is a great need for a healthy hair care. The data from a questionnaire survey was analyzed with 800 female undergraduate students responding. Seventeen universities were included in the study, 8 of which were from Seoul, 6 from other large cities and 3 from smaller towns. The objective of this study is to investigate the correlations of these factors and to provide preliminary data for developing an effective hair care education program. Results include the following: 1. Knowledge score of hair care based on general characteristics were higher for students in larger cites compare to small cites or regions. Also, students in higher academic year, more allowance, interest in their apparence and family income showed higher knowledge in this field. These factors had meaningful effect on the statistics of this study. 2. Attitude score towards hair care based on general characteristics were higher for students in larger cites compare to small cites or regions. Also, students in higher academic year, more allowance, interest in their apparence and family income showed higher knowledge in this field. These factors had meaningful effect on the statistics of this study. 3. Behavior score towards hair care was higher for students with greater family income, allowance, interest in appearance. These factors had meaningful effect on the statistics of this study. 4. The correlation study between knowledge, attitude and behavior showed that higher the knowledge and attitude, better the behavior. 5. The analysis of factors effecting hair care behavior showed that interest in health, acknowledgement of current hair condition, total family income were a viable factor in predicting hair care behavior. The predictability of regression model is 38.9 %($R^2$) Therefore, in order to maximize the hair care behavior, consistent and systematic study should be earned out to develope an effective education program to improve health interest.

• Journal of Integrative Natural Science
• /
• v.10 no.3
• /
• pp.162-170
• /
• 2017

In this paper, it is aim to implement a wheelchair monitoring system that provides users with customized medical services easily in everyday life, together with mobility guarantee, which is the most basic requirement of the elderly and disabled persons with physical disabilities. The case-based intelligent wheelchair monitoring system proposed in this study is based on a case-based k-NN algorithm, which implements a system for constructing and inferring examples of various biometric and environmental information of wheelchair users as a knowledge database and a monitoring interface for wheelchair users. In order to confirm the usefulness of the case-based k-NN algorithm, the SVM algorithm showed an average accuracy of 84.2% and the average accuracy of the proposed case-based k-NN algorithm was 86.2% And showed higher performance in terms of accuracy. The system implemented in this paper has the advantage of measuring biometric information and data communication regardless of time and place and it can provide customized service of wheelchair user through user friendly interface.

• Journal of Preventive Medicine and Public Health
• /
• v.53 no.5
• /
• pp.371-380
• /
• 2020

Objectives: This study investigated the effects of socio-demographic factors on the decreasing trend in the sex ratio at birth from 1997 to 2017 in Korea. Methods: Data from 10 349 602 live births registered with Statistics Korea from 1997 to 2017 were analyzed. The secondary sex ratio (SSR), defined as the ratio of male to female live births, during the study period (1997-1999 [phase I], 2000-2002 [phase II], 2003-2005 [phase III], 2006-2008 [phase IV], 2009-2011 [phase V], 2012-2014 [phase VI], and 2015-2017 [phase VII]) was calculated according to selected socio-demographic factors, such as parental age, education, occupation, and birth order. Logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals for a male birth after adjusting for potential confounders. Results: The SSR gradually decreased from 1.10 (in 1998-2000 and 2002) to 1.05 (in 2013-2016). While a decreasing trend in the SSR was not noted among first births, male-biased sex ratios were prominent among third and higher-order births, for which the highest SSR was 1.46 in 1998. Higher birth order was significantly associated with an excess of male births in phases I-VI (≥third vs. first, OR range, 1.03 to 1.35). Advanced maternal age was significantly associated with an excess of female births in phases II, III, and V (≥40 vs. 20-24 years, OR range, 0.92 to 0.95). Conclusions: This study demonstrated that advanced maternal age and reduction of the artificially-biased SSR among third and higher-order births may partially explain the decreasing trend in the SSR from 1997 to 2017 in Korea.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.45 no.3
• /
• pp.53-60
• /
• 2008

Recently, various recording technologies are studied for optical data storage. After standardization of BD (Blue-ray Disc) and HD-DVD (High-Definition Digital Versatile Disc), the industry is looking for a suitable technology for next generation optical data storage. Super-RENS (Super-resolution near field structure) technique, which is capable of compatibility with other systems, is one of next optical data storage. In this paper, we analyze the nonlinearity of Super-RENS read-out signal through the bicoherence test, which uses HOS (Higher-Order Statistics) and apply neural networks for nonlinear modeling. The model structure considered in this paper is the NARX (Nonlinear AutoRegressive eXogenous) model. The experiment results indicate that the read-out signals have nonlinear characteristics. In addition, it verified the possibility that neural networks can be utilized for nonlinear modeling of Super-RENS systems.

• Journal of Digital Convergence
• /
• v.13 no.12
• /
• pp.187-192
• /
• 2015

If the software is developed to analyze the speech disorder, the application of various converged areas will be very high. This paper implements the user-friendly program based on CART(Classification and regression trees) analysis to distinguish between normal and pathological voices utilizing combination of the acoustical and HOS(Higher-order statistics) parameters. It means convergence between medical information and signal processing. Then the acoustical parameters are Jitter(%) and Shimmer(%). The proposed HOS parameters are means and variances of skewness(MOS and VOS) and kurtosis(MOK and VOK). Database consist of 53 normal and 173 pathological voices distributed by Kay Elemetrics. When the acoustical and proposed parameters together are used to generate the decision tree, the average accuracy is 83.11%. Finally, we developed a program with more user-friendly interface and frameworks.