• Weed & Turfgrass Science
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• v.4 no.2
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• pp.135-143
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• 2015

Typhula ishikariensis Imai is a causal agent of Typhula snow mold, one of the most important turfgrass diseases in northern regions of the United States. Within Wisconsin isolates, there are three district groups clustered with known isolates of T. ishikariensis var. ishikariensis, var. canadensis and var. idahoensis as identified by RAPD markers. To further investigate the genetic relationship among these groups (varieties), monokaryon-monokaryon and dikaryon-monokaryon mating experiments were conducted. Mating types from var. ishikariensis, var. canadensis and var. idahoensis isolates were paired in all possible combinations. Pairings between var. canadensis and var. idahoensis were highly compatible, while no compatibility was detected between var. ishikariensis and either var. canadensis or var. idahoensis. These results indicate that var. ishikariensis is genetically separated from var. canadensis and var. idahoensis, whereas var. canadensis and var. idahoensis appeared to be genetically related to each other as a taxonomic unit. In the genetic relationship with the known biological species, var. ishikariensis and var. canadensis were genetically related to biological species I and II, respectively. However, var. idahoensis was not compatible with any of the biological species, suggesting that the pathogen may be in the process of biological speciation from var. canadensis.

• Journal of Plant Biology
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• v.37 no.1
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• pp.111-124
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• 1994

The delimitation and systematic relationships of the C. foetida complex and related species were evaluated by numerical methods, including principal components analysis and cluster analysis of major morphological characters. Results of these analyses strongly support recognition of three varieties in C. foetida; these include C. foetida var. foetida, C. foetida var. micrantha, and C. foetida var. velutita. The results also indicated that C. brachycarpa, C. frigida, C. heracleifolia, and C. yunnanensis are distinct species, and C. heracleifolia comprises C. heracleifolia var. heracleifolia and C heracleifolia var. bifida. Cimicifuga mairei and C. foetida var. foliolosa, however, appeared to be morphologically indistinguishable from C. foetida var. velutina. In addition, C. foetida var. longibracteata and C. foetida var. bifula are conspecific with C. frigida.rigida.

• Journal of Korea Port Economic Association
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• v.30 no.2
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• pp.77-92
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• 2014

The focus of this study is to analyse dynamic relationship among BDI(Baltic Dry-bulk Index, hereafter BDI), forex market and industrial production using monthly data from 2003-2013. Specifically, we have focused on the investigations how monetary and real variable affect shipping industry during recession period. To compare performance between general VAR and Bayesian VAR we first examine DAG(Directed Acyclic Graph) to clarify causality among the variables and then employ MSFE(mean squared forecast error). The overall estimated results from impulse-response analysis imply that BDI has been strongly affected by other shock, such as forex market and industrial production in Bayesian VAR. In particular, Bayesian VAR show better performance than general VAR in forecasting.

• Journal of Plant Biology
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• v.25 no.4
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• pp.175-180
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• 1982

This paper is proposed to describe three new species and four varieties from Cheju Island to central part of Korea in Southern Korea. The new plant taxa are as follows: clematis taeguensis Y. Lee, sp. nov.; Prunus linearipetalus Y. Lee, sp. nov.; Vicia linearifolia Y. Lee, sp. nov.; Clematis brachyura Maxim. var. hexasepala Y. Lee, var. nov.; Ranunculus quelpaertensis(Lev.) Nakai var. albiflorus Y. Lee, var. nov.; Aconitum napiforme Lev. et Vaniot var. albiflorum Y. Lee, var. nov.; Ajuga decumbens Thunb. var. rosa Y. Lee, var. nov.

• The Korea Journal of Herbology
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• v.20 no.2
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• pp.83-89
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• 2005

Objectives : This study was performed to investigate the effects of Perilla frutescens var. acuta extracts on growth inhibition of Streptococcus pyogenes KCTC 3208. Methods : Measured growth inhibition of Streptococcus pyogenes KCTC 3208 by concentration of the Perilla frutescens var. acuta. extract and collection periods of the Perilla frutescens var. acuta. and picking region of the Perilla frutescens var. acuta. Results : The Perilla frutescens var. acuta. extract is effective on retarding growth of Streptococcus pyogenes KCTC 3208. At 3% the growth of Streptococcus pyogenes KCTC 3208 was suddenly retarded. The stem of Perilla frutescens var. acuta. extract in a sunny place on June is more effective then its leaf. Conclusions : These results suggest that Perilla frutescens var. acuta. extract is effective in growth inhibition of Streptococcus pyogenes KCTC 3208.

• East Asian Economic Review
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• v.22 no.2
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• pp.141-176
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• 2018

The paper analyzes and compares the effects of domestic monetary policy using DSGE, DSGE-VAR, and VAR based on a two-country open economy model of Korea and the U.S. According to impulse response analysis, a domestic interest rate hike raises won value in the case of DSGE and DSGE-VAR models, while in the case of the unrestricted VAR model, it lowers won value. In the marginal data density standard, DSGE-VAR (${\mu}=1$) is superior to DSGE or Bayesian VAR over the sample period. Conversely, in the in-sample RMSE criterion, especially for the won/dollar exchange rate, VARs are superior to DSGE or DSGE-VAR. It is necessary to study further if these differences are caused by model misspecification or omitted variable bias.

• Korean Journal of Plant Taxonomy
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• v.46 no.3
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• pp.306-313
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• 2016

A new variety, Hosta clausa Nakai var. geumgangensis M. Kim & H. Jo, was found in Geumgang River in Korea. This variety shares several characteristics (rhizomes with underground stolon, smooth scape and purple-colored anthers) with the $re{\acute{o}}lated$ varieties H. clausa Nakai var. clausa and H. clausa var. normalis F. Maekawa. However, H. clausa var. normalis has open flowers, capsules with seeds, purple-spotted petioles, long pistils, and long narrow perianth tubes, whereas this new variety has open flowers, seedless capsules, green-colored petioles, short pistils, and short narrow perianth tubes. Hosta clausa Nakai var. clausa has closed flowers and seedless capsules.

• Korean Journal of Plant Taxonomy
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• v.32 no.4
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• pp.397-416
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• 2002

A taxonomic study of Viola section Chamaemelanium in Korea, based on morphological characters, was conducted with light microscopy and scanning electron microscopy. Two species, V. orientalis W. Becker and V. brevistipulata (Fr. et Sav.) W. Becker, are recognized by rhizome and cauline habits, trichomes on the ovary and the shape and beards of stigmas. The latter can be split further into three varieties, var. brevistipulata, var. minor Nakai and var. laciniata (Boiss.) W. Becker, according to the leaf morphology in particular. Viola brevistipulata var. laciniata has the most tooth number, and its teeth are irregular erose but the other two varieties are regular sinuate or serrate. As for the size of leaves, V. brevistipular var. brevistipulata is the largest but V. brevistipulata var. minor is the smallest among the varities. Of them, V. brevistipulata var. laciniata is newly recorded in Korea. It was also revealed that both development and arrangement of the beards developed on the ovary and stigma were particularly diagnostic in the identification of the Viola section Chamaemelanium species.

• Korean Journal of Plant Resources
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• v.30 no.3
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• pp.298-310
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• 2017

Morphological variation between cultivated and weedy types of Perilla frutescens var. frutescens and P. frutescens var. crispa were studied in 327 germplasm by examining 17 morphological characters. The germplasm between the two varieties were varied for their qualitative and quantitative characters. The seed coat color of cultivated P. frutescens var. frutescens is commonly light brown and brown while deep brown color was observed in the weedy type P. frutescens var. frutescens and P. frutescens var. crispa. The leaf size, cluster length, plant height, flower number per cluster and seed weight in cultivated P. frutescens var. frutescens were significantly (P<0.05) different from weedy type P. frutescens var. frutescens and P. frutescens var. crispa. The cultivated P. frutescens var. frutescens exhibited significantly higher plant height (158.6 cm) compared to the weedy P. frutescens var. crispa (133.8 cm). Likewise, seed weight was significantly higher in cultivated (1.9 g) than in the weedy type of P. frutescens var. frutescens (1.6 g) and P. frutescens var. crispa (1.4 g). Principal component analysis (PCA) result showed that the first and second principal component cumulatively explained 86.6% of the total variation. The cultivated type P. frutescens var. frutescens and its weedy accessions were not clearly separated with P. frutescens var. crispa by PCA. Hence it requires the use of molecular markers for better understanding of their genetic diversity.

• The Korean Journal of Financial Management
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• v.22 no.1
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• pp.119-146
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• 2005

This study applies extreme value theory to get extreme value-VAR for Korean Stock market and showed the usefulness of the approach. Block maxima model and POT model were used as extreme value models and tested which model was more appropriate through back testing. It was shown that the block maxima model was unstable as the variation of the estimate was very large depending on the confidence level and the magnitude of the estimates depended largely on the block size. This shows that block maxima model was not appropriate for Korean Stock market. On the other hand POT model was relatively stable even though extreme value VAR depended on the selection of the critical value. Back test also showed VAR showed a better result than delta VAR above 97.5% confidence level. POT model performs better the higher the confidence level, which suggests that POT model is useful as a risk management tool especially for VAR estimates with a confidence level higher than 99%. This study picks up the right tail and left tail of the return distribution and estimates the EVT-VAR for each, which reflects the asymmetry of the return distribution of the Korean Stock market.