• Journal of the Korean Data and Information Science Society
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• v.8 no.2
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• pp.143-152
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• 1997

In this paper, we obtain maximum likelihood estimators for $P(X_{1}\;<\;X_{2})$ in the Marshall and Olkin's bivariate exponential model with bivariate censored data. The asymptotic normality of the estimator is derived. Also we propose approximate testing for $P(X_{1}\;<\;X_{2})$ based on the M.L.E. We compare the test powers under vsrious conditions through Monte Carlo simulation.

• The Korean Journal of Applied Statistics
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• v.24 no.1
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• pp.1-10
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• 2011

This study investigates the dynamic structure of interdependence on the domestic and related major stock markets by employing a statistical framework. Finance theory predicts potential gains by international portfolio diversification if returns from investment in different national stock markets are not perfectly correlated or not cointegrated. The benefit of international diversification is limited when national stock markets are cointegrated because of the limited amount of independent variation by the presence of common factors. The statistical tests suggest that international diversification appears to be favorable after the period of the comovement of the stock prices caused by 1997 Asian financial crisis. The result reflects the increase in overseas investment and purchase of overseas funds after the early 2000's.

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.04a
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• pp.392-393
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• 2000

• Proceedings of the Korean Society of Crop Science Conference
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• 2001.05a
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• pp.74-75
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• 2001

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.5925-5932
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• 2014

The aim of this study was to develop assessment tools for analyzing society focusing on abilities, not an academic clique. The development of a type of occupational qualification, which is called a working and learning system, for Koreans, can be reliable and acceptable to a variety of society members. This study was conducted by searching for a dual system and examining a qualification system in developed countries. To achieve the goal of this study, the management status according to a type of qualification system was analyzed. In addition, a variety of related laws, related department, testing authority, testing institute, terms of applying for tests, way of testing, committee of testing, testing subjects, criterion for passing tests, a status of qualification test administrated in some developed countries, such as Germany, UK, the USA and Australia, were conducted. The occupational duty of the machine field and education contents are examined by analyzing the occupational duty. In addition, the criterion to solve problems and a way of marking in the field of machines were indicated and an example of written and practical tests is presented. This study makes a blueprint for a qualification system of working and learning at the same time in a national dimension.

• Communications for Statistical Applications and Methods
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• v.16 no.4
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• pp.605-614
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• 2009

TGARCH models characterized by asymmetric volatilities have been useful for analyzing various time series in financial econometrics. We are concerned with persistent volatility in the TGARCH context. Park et al. (2009) introduced I-TGARCH process exhibiting a certain persistency in volatility. This article applies I-TGARCH model to various financial time series in Korea and it is obtained that I-TGARCH provides a better fit than competing models.

• Proceedings of the Korean Society of Crop Science Conference
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• 1996.10a
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• pp.54-55
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• 1996

• The Korean Journal of Applied Statistics
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• v.22 no.4
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• pp.781-792
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• 2009

At an early stage of genomic investigations, a small sample of microarrays is used in gene expression experiments to identify small subsets of candidate genes for a further accurate investigation. Unlike the statistical analysis methods for a large sample of microarrays, an appropriate statistical method for identifying small subsets is a randomization test that provides exact P values. These exact P values from a randomization test for a small sample of microarrays are discrete. The possible existence of differentially expressed genes in the sample of a full set of genes can be tested for the null hypothesis of a uniform distribution. Subsets of smaller P values are of prime interest for a further accurate investigation and identifying these outlier cells from a multinomial distribution of P values is possible by M test of Fuchs et al. (1980). Above all, the genome-wide gene expressions in microarrays are correlated, but the majority of statistical analysis methods in the microarray analysis are based on an independence assumption of genes and ignore the possibly correlated expression levels. We investigated with simulation studies the effect that correlated gene expression levels could have on the randomization test results and M test results, and found that the effects are often not ignorable.

• The Korean Journal of Pesticide Science
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• v.20 no.2
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• pp.152-158
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• 2016

The cause of death was investigated with several dead cabbage moth larvae in breeding box. Bacterial strains were isolated and selected from the dead larvae by bioassay. One of them was identified as Serratia marcescens used by morphological characteristics and gene sequencing. S. marcescens were cultured by Luria Bertani (LB) media broth for bioassay. When 100-fold dilution of culture broth to third larvae of diamondback moth, Plutella xylostella, it was showed a 100% mortality at 2 days after treatment, and only 10-fold dilution of supernatant liquid was showed 86.6% mortality. When the culture broth of S. marcescens was applied to the larvae of beet armyworm, Spodoptera exigua, contact and feeding toxicity were 20 and 8% of mortality, respectively. Otherwise, when the culture broth of S. marcescens was applied to 5 major plant pathogens, antibacterial activities against Fusarium oxysporum, Rhizoctonia solani, Colletotrichum gloeosporioides, Phytophthora capsici and Sclerotinias clerotiorum were 4.7, 11.3, 20, 15.7 and 42.6%, respectively. Also, degradation ability of S. marcescens against protein and chitin were examined.

• Korean Journal Plant Pathology
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• v.1 no.1
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• pp.33-37
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• 1985

A yellow stripe and bud benting disease of soybean was commonly observed on the field at Suweon area. The causal agent was identified as alfalfa mosaic virus (AMV) by indicator plant reactions, physical properties, serological test and electron microscopy. AMV produced vein clearing, top necrosis, top bent and mottling on the parts of soybean plants. Local lesions were produced on the inoculated leaves of Vigna sesquipedialis, Vicia faba and Tetragonia expansa, while Chenopodium am, anticolor, C. quinoa, Pisum satvium, Petunia hybrida and Nicotiana tabacum 'Bright yellow' were systemically infected. The thermal inactivation point was $60^{\circ}C$, dilution end point was $10^{-3}$, and longevity in vitro was 2 days at room temperature. AMV from soybean was reacted with AMV - antiserum in agar gel diffusion test. Electron microscopy of AMV from soybean exhibited bacilliform particles of 60nm in length.