• The Korean Journal of Ecology
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• v.7 no.4
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• pp.208-232
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• 1984

A survey was conducted on the vegetation of Seogmo island, which is small island (ca. 41 okm2) located about 1km west of Kanghwa island in the central Korea, from Aug. 1983 to May 1984. Based on the field data, actual vegetation map and potential natural vegetation map were made. The island is covered with broad-leaved trees dominated with Quercus variabilis. The dominance diversity curves obtaiend in different associations are grouped in two types, lognormal distribution forms at the undisturbed vegetation and geometric series at the disturbed or rocky sites. It seems that the curves show to us the nature of their ecocline by the hypothesis of some investigators, i.e. Random niche boundary hypothesis, niche preemption hypothesis, lognormal distribution and logarithmic series. Total numbers of vascular plant species of the island were recorded 108 families, 348 genera, 475 species, 73 variaties and 7 forma. And Pte.-Q Index, 0.93, and Fisher's Index, 589.8, were higher than those in neighboring islands.

• Journal of Navigation and Port Research
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• v.44 no.5
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• pp.407-413
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• 2020

In this paper we examined a novel extension of the convergence empirics for the maritime business cycle which considers structure breaks and/or changes. To provide theoretical justification, the convergence hypothesis uses the relaxed assumption to technology shocks. Based on the recent empirical results provided by Kim and Chang (2020), we consider nonlinear dynamics that capture the properties on structural changes in the equilibrium adjustment process. This approach bridges the gap between the theoretical framework and empirical specifications. In particular, we applied the convergence hypothesis to the multiple structure change model for the maritime business cycle. Our application to the maritime data showed support of the convergence hypothesis allowing multiple structure changes during the high volatile period and offers additional insight into the forecasting maritime business cycles.

• Journal of applied mathematics & informatics
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• v.26 no.3_4
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• pp.679-688
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• 2008

In multivariate regression analysis there exist many influence measures on the regression estimates. However it seems to be few of influence diagnostics on test statistics in hypothesis testing. Case-deletion approach is fundamental for investigating influence of observations on estimates or statistics. Tang and Fung (1997) derived single case-deletion of the Wilks' ratio, Lawley-Hotelling trace, Pillai's trace for testing a general linear hypothesis of the regression coefficients in multivariate regression. In this paper we derived more extended form of those measures to deal with joint influence among observations. A numerical example is given to illustrate the effect of joint influence on the test statistics.

• Korean Journal of Rural Living Science
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• v.6 no.2
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• pp.173-183
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• 1995

On the basis of intertemporal utility maximization theory and stock-adjustment hypothesis, a multivariate stock-adjustment credit demand model, which included on- and cross-adjustment effects of credit and cross-adjustment effects of assets was developed. With weighted four-year panel data from 1983 and 1986 Surveys of Consumer Finances, the theoretical model was tested using two-stage estimation method for tobit model. The results supported the hypothesis that, in general, the household demand for a certain type of credit was related to the demand for other types of credit and asset components in the portfolio. The household demand for mortgage credit, installment credit and revolving credit card debt depended not only on the disequilibrium of itself but on the disequilibrium of the other types of credit and asset components in the portfolio. The household demand for non-installment credit was related not to the disequilibrium of itself and other types of credit but to the disequilibria of asset components in the portfolio.

• East Asian Economic Review
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• v.17 no.4
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• pp.417-444
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• 2013

This paper aims to empirically identify the effects of FTAs on outward and inward FDIs in Korea. Considering the income differences between Korea and its FTA partners, we hypothesize that FTAs have a positive effect on outward FDI to developing countries and inward FDI from developed countries. An underlying source of the hypothesis is the Knowledge-Capital model, addressing the positive (negative) relationship between trade costs and horizontal (vertical) FDI. We test for the hypothesis using data on Korea's FTAs and FDI over the period 2000-2010. We find that our empirical results support the hypothesis, and additionally, FTAs in general encourage FDI by creating an FDI-friendly environment.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.405-408
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• 2007

Vestibular hair cells, the sensory receptors of vestibular organs, selectively amplify miniscule stimuli to attain high sensitivity. Such selective amplification results in compressive nonlinear sensitivity, which plays an important role in expanding dynamic range while ensuring robustness of the system. In this study, negative stiffness mechanism, a mechanism responsible for the selective amplification by vestibular hair cells, is applied to a simple mechanical system consisting of an array of inverted pendulums. The structure and working principle of the system have been inspired by gating spring hypothesis proposing that opening and closing of transduction channels contributes to the global stiffness of vestibular hair bundle. Parameter study was carried out to analyze the effect of each parameter on the compressive nonlinearity of suggested model.

• Clinical and Experimental Pediatrics
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• v.55 no.11
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• pp.445-448
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• 2012

Kikuchi-Fujimoto disease (KFD) is a benign self-limiting disease characterized by fever and lymphadenitis. The etiology and pathogenesis of KFD is unclear. However, two hypotheses have been suggested: a viral infection hypothesis and an autoimmune hypothesis. Several KFD patients with various types of autoimmune diseases have been reported, and these reports support the hypothesis for autoimmune pathogenesis of KFD. Here, we report the case of a 17-year-old female patient diagnosed with KFD and autoimmune thyroiditis. This case serves as additional evidence that the etiology of KFD is autoimmune origin.

• Journal of Labour Economics
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• v.38 no.2
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• pp.25-58
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• 2015

This paper compares income and consumption inequalities in Korea and applies the permanent income hypothesis to interpret the linkage between the two inequalities. Income inequality has been increasing since 1990 while consumption inequality had been decreasing until the early 2000s when the two inequalities started to co-move. Permanent income hypothesis explains reasonably well the consumption pattern in the recent period, which reflects the increased access to asset markets by the Korean households. Consequently, the co-movement of income and consumption inequalities in the recent period implies that inequality in permanent income components are fluctuating.

• Asian Journal of Business Environment
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• v.4 no.1
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• pp.37-40
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• 2014

Purpose - This objective of this study is to analyze the factors that impact Chinese consumers' purchasing intent for high-tech products. The study examines smart phones'features, Chinese personal consumer characteristics, and social influence. Research design, data, and methodology - The study employed survey data based on 200 questionnaires in principal Chinese cites between October and December 2011. SPSS 17.0 was employed to analyze the data used to test the hypotheses the analysis results confirmed some hypotheses proposed. Results - Hypothesis 1, Hypothesis 4, and Hypothesis 7 proposing that utilization, social image, and attractiveness, respectively, of smart phone elements influence the Chinese consumers' purchasing intent are supported. Conclusions - This study found the factors that impact purchasing intent for high-tech products among Chinese consumers, with some factors like social image, attractiveness, and utilization playing critical roles; however, hypotheses proposing factors such as ease of use, pleasantness, personal innovativeness, and compatibility were rejected. In future, more research focusing on the elements of smart phones is required.

• Journal of Korean Society for Quality Management
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• v.36 no.4
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• pp.1-6
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• 2008

As more and more data are collected one may ask whether the data collected within a short period of time are same. In this case traditional hypothesis testing of $H_o:{\mu}_1={\mu}_2$ vs $H_1:{\mu}_1{\neq}{\mu}_2$ is used to determine whether the data are same when there is no knowledge about equivalence testing. However, this type of hypothesis testing has the undesirable property of penalizing higher precision. So TOST is to be performed in the event of equivalence testing. In this study equivalence testing is introduced where one can find the applications in industry. Traditional two sample t testing is to be compared with the equivalent testing and the procedure to perform the equivalence testing is to be presented along with an example. Finally equivalence testing in terms of the other parameters such as variance, proportion or failure rate is to be sought.