• The Korean Journal of Applied Statistics
• /
• v.17 no.3
• /
• pp.507-518
• /
• 2004

Malkovich & Afifi (1973) generalized the univariate skewness and kurtosis to test a hypothesis of multivariate normality by use of the union-intersection principle. However these statistics are hard to compute for high dimensions. We propose the approximate statistics to them, which are practical for a high dimensional data set. We also compare the proposed statistics to Mardia(1970)'s multivariate skewness and kurtosis by a Monte Carlo study.

• Journal of Distribution Science
• /
• v.12 no.5
• /
• pp.93-107
• /
• 2014

Purpose - The pool of entrepreneurs with progressive qualities such as creativity and innovation was considered concurrently with such factors as work and capital that stimulate economic development and growth. This study aims to present a model to support the development of a strategic approach for achieving an overall academic entrepreneurship system in Iran. Research design, data, and methodology - The research design of this study is based on applied research because of its objectives, using principles and techniques formulated for basic research to solve operational and real organizational issues. This design also drives the method used, describing and interpreting the findings. Secondary data (library research) was used for this study's data collection. Because of this research's essential characteristics, no hypothesis is launched, and no research setting, questionnaire design, population or population sampling, validity or reliability tests, or statistical analysis are needed. Results and Conclusions - The model is created using a strategic approach acting in an octal setting comprising social, cultural, legal, economic, political, technological, competitive, and natural environments to present a conceptual framework for future studies.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.63 no.11
• /
• pp.1545-1550
• /
• 2014

Fault detection and diagnosis (FDD) of photovoltaic (PV) power systems is one of significant techniques for reducing economic loss due to abnormality occurred in PV modules. This paper presents a new FDD method against PV power systems by using statistical comparison. This comparative approach includes deviation signals between the outputs of two neighboring PV modules. We first define a binary hypothesis testing under such deviation and make use of a generalized likelihood ratio testing (GLRT) theory to derive its FDD algorithm. Additionally, a recursive computational mechanism for our proposed FDD algorithm is presented for improving a computational effectiveness in practice. We carry out a real-time experiment to test reliability of the proposed FDD algorithm by utilizing a lab based PV test-bed system.

• The Korean Journal of Applied Statistics
• /
• v.3 no.1
• /
• pp.89-103
• /
• 1990

An analysis of mean procedure is presented for testing the significance of two factor interactions for unbalanced case. When at least one factor if at only two levels, the technique is the same as that of Ott(1967) and Nelson(1988) except that we have used the critical value by using the Sidak's multiplicative inequality. The technique can be extended to the case in which both factors more than two levels. Tables of critical values g($\alpha ; (p, q) ; v$) are given for $\alpha$=0.05 and 0.01 ; (p, q) combinations satisfying $3 \leq p \leq q \leq 5$ ; and various degrees of freedom v. We present and prove the formula of the variance of the interactions for the n-way model.

• The Korean Journal of Applied Statistics
• /
• v.32 no.6
• /
• pp.879-887
• /
• 2019

We construct a procedure to test the stochastic order of two samples of interval-valued data. We propose a test statistic that belongs to a U-statistic and derive its asymptotic distribution under the null hypothesis. We compare the performance of the newly proposed method with the existing one-sided bivariate Kolmogorov-Smirnov test using real data and simulated data.

• Journal of Technology Innovation
• /
• v.16 no.2
• /
• pp.147-165
• /
• 2008

The researches on cyclical patterns of R&D investment has a long history in developed economies since the Schumpeterian hypothesis that long-term productivity-enhancing innovative activities increase during recession. But in Korea the cyclical patterns of R&D investment is one of the unexplored academic areas. Unlike theoretical explanation of R&D's cyclical pattern, empirical results has shown that R&D investment is procyclical to business cycles in developed countries. This paper investigates whether Korean R&D investment show procyclical or countercyclical pattern to business cycles. The empirical results show that Korean R&D investment in private area is procyclical to business cycles with statistical significance, which confirms the credit-constraint theory's prediction, while public area's is not sensitive to them. Public R&D investment has long-term investment characteristics and can be utilized to stabilize procyclically-fluctuating private R&D investment.

• Korean Journal of Veterinary Research
• /
• v.53 no.2
• /
• pp.73-76
• /
• 2013

The aim of this study was to produce a simple and inexpensive technique for estimating the obturator foramen area (OFA) from young calves based on the hypothesis that OFA can be extrapolated from simple linear measurements. Three linear measurements - dorsoventral height, craneocaudal width and total perimeter of obturator foramen - were obtained from 55 bovine hemicoxae. Different algorithms for determining OFA were then produced with a regression analysis (curve fitting) and statistical analysis software. The most simple equation was OFA ($mm^2$) = [3,150.538 + ($36.111^*CW$)] - [147,856.033/DH] (where CW = craneocaudal width and DH = dorsoventral height, both in mm), representing a good nonlinear model with a standard deviation of error for the estimate of 232.44 and a coefficient of multiple determination of 0.846. This formula may be helpful as a repeatable and easily performed estimation of the obturator foramen area in young bovines. The area of the obturator foramen magnum can thus be estimated using this regression formula.

• Journal of Digital Convergence
• /
• v.7 no.4
• /
• pp.141-148
• /
• 2009

The purpose of this study is to examine the causal correlation between communication skill of organization and their job performance. In our model, we used these variables - innovation awareness, job satisfaction, organizational commitment as a parameter. In order to verify the hypothesis based on research model, a survey among researchers (sample size=117) who work in food company was carried out. Analyzing hypothesized model and following the statistical procedure, we could assure that there exist positive correlation with communication skill, innovation awareness, job satisfaction, organizational commitment and organizational performance. A coefficient of correlation between those variables was clearly high in the group with good communication skill. Among the parameters, the variable of innovation awareness was more effected on their job performance.

• Korean Journal of Child Studies
• /
• v.21 no.4
• /
• pp.51-68
• /
• 2000

To reveal when toddlers and children acquire the grammatical morpheme of Korean language, this study investigated the way they respond to some picture tasks. The object of this research was 174 children ranging from 18 months to 60 months, who were selected from two child-care centers located in Seoul and Gyeongi Province. Following the statistical analysis of the data, this study ascertained that 2-, and 3- year-old children acquire the most part of grammatical morphemes such as nouns, pronouns, verbs, adverbs, adjectives, and interrogation terms. The fact that the process of acquisition was significantly different among six age groups has proved the hypothesis of the gradual acquisition of grammatical morpheme.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.35S no.4
• /
• pp.85-95
• /
• 1998

In this paper, a new watermarking method for a copy protectionof images is proposed. The proposed method adaptively embeds a watermark in the frequency domain of images using human visual system model. For this purpose, the Just Noticeable Differences(JNDs) of each frequency coeffeicient value of a luminance plane is first found using Watson and Solomon's visual system model. An invisible maximum watermark value with is different in every position according to the characteristics of images is determined usig JND and Minkowski metric. A low frequency domain is divided into two sets based on a PN-sequence to protect thewatermark from the attack. The watermarks are added to one set of coefficients and detecting a watermark, the difference between the mean values of absolute coefficient values of both sets is calculated. The embedded watermark is tested using statistical hypothesis based on test static dertermined by the ean difference. To demonstrate the perfromance of the proposed method, the new watermarking method is applied to a high frequency image and low frequency images. Experimenatal results show the watermark is invisible and robust to JPEGlossy compression and noise.