• Title/Summary/Keyword: restricted VAR

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Cultural Conditions for the Production of Organic Acid During (Aspergillus awamori var. kawachii에 의한 쌀 Koji 제조시 유기산의 생산조건)

  • 소경환
    • The Korean Journal of Food And Nutrition
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    • v.6 no.4
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    • pp.287-293
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    • 1993
  • This study was carried out to investigate the influences of cultural conditions of koji on the production of organic acid during rice-koji making by Aspergillus awamori var. kawachii which is now widely used as koji-mold in brewing Takju and Yakju in Korea. The optimum temperature for the germination of the conidia of the mold was 35'8, and the time required for germination at this temperature was 8 hours. Rapid germination occurred when the water content of steamed rice was above 40%, but germination retardation occurred markedly below 35%. The optimum cultural temperature for the production of organic acid was 32$^{\circ}C$, and the production of organic acid was markedly restricted at 36$^{\circ}C$ and 4$0^{\circ}C$. It was effective for the high production of both saccharogenic amylase and organic acid to shift the cultural temperature from initial 36$^{\circ}C$ to 32$^{\circ}C$ after 20~25 hours of cultivation. Initial water content suitable to the production of organic acid was 40% in steamed rice, but its production was markedly restricted below 30% of water content. When the quantity of conidial inoculation was too small, the production of organic acid was low in initial phase, but it was retrived at later period. Acid production was markedly restricted together with the increase in koji thickness.

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Distribution Atlas of Plants in Korea Ⅵ. Atlas of Aceraceae (한국 식물의 분포에 관한 연구 Ⅵ. 단풍나무과의 분포도)

  • 김윤식;고성철;심정기
    • Journal of Plant Biology
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    • v.24 no.4
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    • pp.191-216
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    • 1981
  • In our present investigations, distributions of Korean Aceraceae with single genus composed of 16 species, 14 varieties and 1 form were studied. Distributional atlases were made by UTM grid map and drawing methods have been previously described (Distribution Atlas of Plants of Korea I, II, and III). Acer okamotoanum and A. takesimense of Korean endemic species are commonly distributed in Dagelet Island but the latter also in such islands as Quelpart, Wan-Do and Heucksan-Do. A. palmatum var. nakaii is found in the middle and the northern parts of the subtropics, and A. micro-sieboldianum and A. nudricarpum restricted to the middle part of the country are endemic species of Korea. A. barbinerve and A. tegmentosum as species from the north are distributed to the top of Mt. Chiri in the south and are also found in Mt. Nangrim and Baiktu in the north. A. ginnala and A. mono are commonly distributed in Liaotung-Pantao and Shantung-Pantao, or Chinese peninsulas, and South Manchuria with Korean Peninsula. A. barbinerve, A. tegmentosum, A. triflorum, A. tschonoskii and A. ukurunduense in south Manchuria, north Manchuria and Korea are florae derived from Manchuria, and A. japonicum, A. momo var. ambiguum, A. mono var. savatieri, A. palmatum var. matsumurae and A. ukurunduense var. pilosum appear in Korea and Japan.

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New record of genus Viola: Viola grypoceras A. Gray var. pubescens Nakai in Korea (제비꽃속의 미기록 변종 : 털낚시제비꽃)

  • Jang, Su-Kil;Lee, Woo-Tchul;Yoo, Ki-Oug
    • Korean Journal of Plant Taxonomy
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    • v.39 no.4
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    • pp.299-303
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    • 2009
  • We report an unrecorded taxon of genus Viola, V. grypoceras A. Gray var. pubescens Nakai, collected on Jeju Island, Korea. The distribution of this variety was restricted to the northern part of Japan, Hokkaido in particular. It is distinguished from V. grypoceras in that it is densely pilose except on its spur and lateral petals. We gave it the Korean name 'Tul-nak-si-je-bi-kkot' based on the morphological characters. In addition, some illustrations of this variety and a key to the V. grypoceras complex were provided.

Cultural Conditions for the Production of Saccharogenic Amylase During Rice-Koji Making by Aspergillus awamori var. kawachii (Aspergillus awamori var. kawachii에 의한 쌀 Koji제조시 당화효소의 생산조건)

  • 오명환
    • The Korean Journal of Food And Nutrition
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    • v.6 no.4
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    • pp.294-300
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    • 1993
  • This study was carried out to investigate the influences of cultural conditions of koji on the production of saccharogenic amylase during rice-koji making by Aspergillus awamori var. kawachii which is now widely used as koji-mold in brewing Tikju and Yakju in Korea. The optimum cultural temperature for the production of saccharogenic amylase by this mold was 36$^{\circ}C$, and at this temperature it needed 40 hours of cultivation for maximum production of this enzyme. It was favorable for high production of both organic acid and saccharogenic amylase to shift the cultural temperature form initial 36$^{\circ}C$ to 32$^{\circ}C$ after 20~25 hours of cultivation. The production of saccharogenic amylase was low when the water content of steamed rice was below 35%, but its production was high at 40~60% of water content. When the quantity of conidial inoculation was too small, the production of saccharogenic amylase was low in initial phase, but it was retrived after 40 hours of cultivation. When koji-thickness was over 3cm, the production of saccharogenic amylase was markedly restricted. The saccharogenic amylase of this koji was stable at pH 2~7, and showed high activity at pH 2~5.

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Asset Price, the Exchange Rate, and Trade Balances in China: A Sign Restriction VAR Approach

  • Kim, Wongi
    • East Asian Economic Review
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    • v.22 no.3
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    • pp.371-400
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    • 2018
  • Although asset price is an important factor in determining changes in external balances, no studies have investigated it from the Chinese perspective. In this study, I empirically examine the underlying driving forces of China's trade balances, particularly the role of asset price and the real exchange rate. To this end, I estimate a sign-restricted structural vector autoregressive model with quarterly time series data for China, using the Bayesian method. The results show that changes in asset price affect China's trade balances through private consumption and investment. Also, an appreciation of the real exchange rate tends to deteriorate trade balances in China. Furthermore, forecast error variance decomposition results indicate that changes in asset price (stock price and housing price) explain about 20% variability of trade balances, while changes in the real exchange rate can explain about 10%.

Structure, Ontogeny and Biology of Nectaries in Luffa acutanqqula (L.) Roxb. var. amara (Lam.) Cl.

  • Haran Iyer, K.R.P.;Subramanian, R.B.;Inamdar, J.A.
    • Journal of Plant Biology
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    • v.32 no.2
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    • pp.101-107
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    • 1989
  • Luffa acutanqula var. amara exhibits floral and extrafloral nectaries. The floral nectaries are restricted to the torus of the male flowers, while the extrafloral nectaries are observed on foliage leaves, probract, outer surface of calyx and pedicels. The floral nectaries develop from a group of epidermal and sub-epidermal initials which differentiate into secretory and subsecretory zones respectively during further divisions. The extrafloral nectary initiates from a single papillate nectary initial which gives rise to mature nectary comprising stalk layer, secretory and subsecretory tissues. Both the floral and extrafloral nectaries are vascularized. Interactions between insect-visitors and the plant with special reference to their functions are also discussed.

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Genetic Variation in Korean Populations of Wild Radish, Raphanus sativus var.hortensis f. raphanistroides (Brassicaceae)

  • Hur, Man Kyu
    • Journal of Plant Biology
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    • v.38 no.4
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    • pp.329-336
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    • 1995
  • Raphanus sativus L. var. hortensis f. raphanistroides (wild radish: Brassicaceae), a herbaceous perennial, occurs only on beaches in East Asia. Genetic diversity and population structure of seven Korean populations were investigated using starch gel electrophoresis. Although the Korean populatins are small, isolated with patchy distribution, the population maintain a moderate level of genetic diversity; the mean percentage fo polymorphic loci was 51.4%, mean number of alleles per locus was 1.84, and mean expected heterozygosity was 0.116. A combination of animal-outcrossing breeding system, wide geographical distribution, restricted ecological distribution, and a propensity for high fecundity may in part be explanatory factors contributing the moderate level of genetic diversity within populations. An overall excess of homozygotes relative to Hardy-Weinberg expetations (mean FISa=0.116) indicates that consanguineous mating occur within wild radish populations, leading to a family structure within a circumscribed area. Although population of wild radish experience a limited gene flow, only 5% of the total genetic variation found in Korean wild radish populations examined is due to differences among populations (mean GST=0.052). This value is considerably lower than the mean values of species with similar life history and ecological characteristics. However, significant differences were found in allele frequencies between populations for all polymorphic loci (P<0.01). It is supposed that directional selection toward genetic uniformity (similar gene frequencies) in a relatively homogenous habitat is thought to be operated among Korean wild radish populations.

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Control of Sulfonylurea Herbicide-Resistant Lindernia dubia in Korean Rice Culture

  • Kuk, Yong-In
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.47 no.4
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    • pp.328-334
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    • 2002
  • A Lindernia dubia (L.) Pennell var. dubia accession from Jeonnam province, Korea was tested for resistance to sulfonylurea (SU) herbicides, imazosulfuron and pyrazosulfuron-ethyl in whole-plant response bioassay. The accession was confirmed resistant to both herbicides. The $GR_{50}$ (herbicide concentration that reduced shoot dry weight by 50%) values of resistant accession were 264 and 19 times higher to imazosulfuron and pyrazosulfuronethyl, respectively, than that of the standard susceptible accession. The surviving resistant L. dubia after pyrazosulfuron-ethyl + molinate application can be controlled by sequential applications of soil-applied herbicides, butachlor, dithiopyr, pyrazolate, and thiobencarb and foliar herbicides, bentazon. Sulfonylurea-based mixtures such as mixtures of azimsulfuron + anilofos, bensulfuron-methyl + oxadiazon, pyrazosulfuron-ethyl + fentrazamide, and pyrazosulfuron-ethyl + anilofos + carfentrazon can also be used to control the surviving resistant L. dubia. However, use of these mixtures should be restricted to a special need basis. Thus, we suggest that sequential applications of non-SU-based mixtures such as butachlor + pyrazolate and MCPB + molinate + simetryne be used to control the surviving resistant L. dubia after SU herbicide applications. Rice yield was reduced 24 % by resistant L. dubia that survived after the pyrazosulfuron-ethyl + molinate application compared with pyrazolate + butachlor in transplanted rice culture. In vitro ALS activity of the resistant biotype was 40 and 30 times more resistant to imazosulfuron and pyrazosulfuron-ethyl, respectively, than the susceptible biotype. Result of in vitro ALS assay that the resistance mechanism of L. dubia to SU herbicides may be due, in part, to an alteration in the target enzyme, ALS.

Globalization of Capital Markets and Monetary Policy Independence in Korea (자본시장의 글로벌화와 한국 통화정책의 독립성)

  • Kim, Soyoung;Shin, Kwanho
    • KDI Journal of Economic Policy
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    • v.32 no.2
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    • pp.1-26
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    • 2010
  • This paper empirically examines whether Korean monetary policy is independent of U.S. monetary policy during the post-crisis period in which capital account is liberalized and floating exchange rate regime is adopted and during the pre-crisis period in which capital mobility is restricted and tightly managed exchange rate regime is adopted. Before capital account liberalization, monetary autonomy can be achieved in view of the trillema, even under tightly managed exchange rate regime, as capital mobility is restricted. On the other hand, for the period after capital account liberalization, monetary autonomy can be also achieved in view of the trillema, as exchange rate stability is given up. Securing monetary autonomy, however, may not be easy under liberalized capital account for a small open economy like Korea. Huge capital movements can generate excessive instability in foreign exchange and asset markets. Strengthened international economic linkages may also be another factor to prevent monetary policy from being independent. Using block-exogenous structural VAR model, the effects of U.S. monetary policy shocks on Korean economy are examined. Empirical results show that Korean monetary policy is not independent of U.S. monetary policy for both periods before and after capital account liberalization. For the period after capital account liberalization, Korea does not seem to have implemented floating exchange rate policy in practice, which may lead Korean monetary policy to be dependent on U.S. monetary policy. For the period after capital account liberalization, portfolio flows respond dramatically to the U.S. monetary policy, which may also keep Korean monetary policy from being independent.

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Spatial Genetic Structure and Genetic Diversity of a Rare Endemic Juniperus chinensis var. sargentii in Mt. Halla, Korea (희귀식물인 눈향나무(Juniperus chinensis var. sargentii)의 공간분포에 따른 유전구조 및 유전적 다양성)

  • Choi, Hyung-Soon;Hong, Kyung-Nak;Chung, Jae-Min;Kim, Won-Woo
    • The Korean Journal of Ecology
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    • v.27 no.5
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    • pp.257-261
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    • 2004
  • Juniperus chinensis var. sargentii Henry is a short and creeping evergreen shrub which reaches about 50㎝ in height and occurs in the northeast Asia and in high mountains over the South Korea. Its distribution is restricted, and the number of individuals are gradually decreasing. This study was conducted to estimate spatial pattern, genetic diversity and spatial genetic structure of J. chinensis var. sargentii. A total of 131 clumps were studied in the study area (40m × 60m). The spatial pattern of this population was random (Aggregation index R=1.031). In spite of the small number and the limited distribution, the level of genetic diversity (Shannon's index 1=0.463) was relatively high as compared with those of other plant species with similar ecological characteristics. ISSR genotypes of all individuals were investigated to find the genetic relationship of clumps and genets. Fifteen clumps were composed to be clones, and a total of 116 unique genotypes were composed by separate genets. Spatial autocorrelation analysis using Tanimoto distance showed that the genetic patch was established within 8m. The effect of clonal reproduction on genetic structure was almost nothing.