• Title/Summary/Keyword: Structural VAR

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Vegetation Characteristics of Corylopsis gotoana var. coreana community at Mt. Baegun in Pocheon (포천 백운산 히어리 군락의 식생 특성)

  • Oh, Young-Ju;Bang, Jeong-Ho;Paik, Woen-Ki
    • Korean Journal of Plant Resources
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    • v.25 no.4
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    • pp.447-455
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    • 2012
  • The phytosociological study was carried out to investigate the Corylopsis gotoana var. coreana community structural characteristics and soil environment of Mt. Baegun in Pochen. The vegetation data of total 9 relev$\acute{e}$s were analyzed by the Z$\ddot{u}$rich-Montpellier school's method. Three communities of Mt. Baegun were recognized : Corylopsis gotoana var. coreana - Quercus mongolica community, Corylopsis gotoana var. coreana - Carpinus laxiflora community, Corylopsis gotoana var. coreana typical community. The reanalysis to Corylopsis gotoana var. coreana community structural characteristics in south area classified 8 communities by literature. PCA analysis of Corylopsis gotoana var. coreana community distributed in the middle and southern area showed that the Corylopsis gotoana var. coreana community of the Mt. Jiri in the southern area was highly correlated with the one of Mt. Baegun in the middle area.

A Study on the Comovements and Structural Changes of Global Business Cycles using MS-VAR models (MS-VAR 모형을 이용한 글로벌 경기변동의 동조화 및 구조적 변화에 대한 연구)

  • Lee, Kyung-Hee;Kim, Kyung-Soo
    • Management & Information Systems Review
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    • v.35 no.3
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    • pp.1-22
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    • 2016
  • We analyzed the international comovements and structural changes in the quarterly real GDP by the Markov-switching vector autoregressive model (MS-VAR) from 1971(1) to 2016(1). The main results of this study were as follows. First, the business cycle phenomenon that occurs in the models or individual time series in real GDP has been grasped through the MS-VAR models. Unlike previous studies, this study showed the significant comovements, asymmetry and structural changes in the MS-VAR model using a real GDP across countries. Second, even if there was a partial difference, there were remarkable structural changes in the economy contraction regime(recession), such as 1988(2) ending the global oil shock crisis and 2007(3) starting the global financial crisis by the MS-VAR model. Third, large-scale structural changes were generated in the economic expansion and/or contraction regime simultaneously among countries. We found that the second world oil shocks that occurred after the first global oil shocks of 1973 and 1974 were the main reasons that caused the large-scale comovements of the international real GDP among countries. In addition, the spillover between Korea and 5 countries has been weak during the Asian currency crisis from 1997 to 1999, but there was strong transmission between Korea and 5 countries at the end of 2007 including the period of the global financial crisis. Fourth, it showed characteristics that simultaneous correlation appeared to be high due to the country-specific shocks generated for each country with the regime switching using real GDP since 1973. Thus, we confirmed that conclusions were consistent with a number of theoretical and empirical evidence available, and the macro-economic changes were mainly caused by the global shocks for the past 30 years. This study found that the global business cycles were due to large-scale asymmetric shocks in addition to the general changes, and then showed the main international comovements and/or structural changes through country-specific shocks.

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Financial Integration in East Asia: Evidence from Stock Prices (주가지수를 통해 살펴본 동아시아의 금융통합에 대한 연구)

  • Zhao, Xiaodan;Kim, Yoonbai
    • KDI Journal of Economic Policy
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    • v.33 no.4
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    • pp.27-48
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    • 2011
  • This paper investigates the extent of global and regional integration in East Asia using stock price index as a measure of economic performance. We employ a structural VAR model to separate the underlying shocks into "global", "regional" and "country-specific" shocks. The estimation results show that country-specific shocks still play a dominant role in East Asia although their role appears to have declined over time, especially after the 1997 financial crisis. Global and regional shocks are responsible for small but increasing shares of stock price fluctuations in all countries. The results indicate that the stock markets in East Asia remain dissimilar and are subject to asymmetric shocks in comparison to European countries.

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Contribution of institutional shocks to Tunisian macroeconomic fluctuations: Structural VAR approach

  • Zouhaier, Hadhek
    • East Asian Journal of Business Economics (EAJBE)
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    • v.1 no.1
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    • pp.8-16
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    • 2013
  • Purpose: The objective of this paper is to identify and assess the contribution of budgetary, monetary and institutional shocks affecting the Tunisian economy over the period 1976-2003. The methodology used is vector autoregressive models and structural recent techniques for the analysis of time series related. The empirical results show a significant relationship between the supply shock and institutions on the one hand, and between institutional shocks and economic activity on the other hand. Research Design, Data and Methodology: As part of this section we will try to identify and assess the contribution of various shocks to macroeconomic variables' fluctuations for the Tunisian economy. The study period is: 1976-2003 and observations are annual. Results: The real business cycle theory argues that fluctuations in aggregate economic activity are the result of the interaction of the only real factors namely agents' preferences, technological opportunities, factor endowments and possibly certain institutional constraints. Conclusions: The lowest contribution to the variability of these rights is the monetary shock. As for "civil liberties", the largest share of their variability is the shock relating to the "political rights" during the first four periods .

Distribution of Aucuba japonica in two contrasting geobotanical regions of Japan: An analysis of adaptation mode

  • Ali, Md. Sohrab;Kikuzawa, Kihachiro
    • Journal of Ecology and Environment
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    • v.36 no.3
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    • pp.173-181
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    • 2013
  • Two varieties of Aucuba japonica differ in ways that can be considered adaptive to differing geo-climatic conditions in their respective distribution ranges. Irrespective of growth stage, the mean leaf size of A. japonica var. japonica was significantly larger than A. japonica var. borealis. Smaller leaf size and ultimately smaller stature of A. japonica var. borealis are an advantage under the higher snow load and lower temperatures in the forests along the East Sea where the variety grows. Snow load also acted as an important driving force for structural modifications of A. japonica var. borealis from cellular level in leaves to the organization of branch extension growth. Global warming by changing snowfall patterns in Japan may lead to range shifts in the two varieties of A. japonica.

Changes in Real Exchange Rate and Business Fluctuations: A Comparative Study of Korea and Japan (실질환율변동의 경기변동효과: 한국과 일본의 비교연구)

  • Kwak, Tae Woon
    • International Area Studies Review
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    • v.13 no.3
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    • pp.309-330
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    • 2009
  • This paper analyzes comparatively the effects of changes in real effective exchange rates on the business fluctuations of the cases of Korea and Japan employing structural vector auto-regression(S-VAR) model which uses quarterly data for the five variables of real effective exchange rates, GDP gap, real interest rates, oil prices, inflation rates for the period of 1980-2006. The paper employes impulse-response analysis and variance decompositions. The paper finds that real exchange rate depreciations are contractionay for the case of Korea while they are expansionary for the case of Japan. These results are consistent with the prevailing empirical results that real exchange rate depreciations are contractionary for developing countries while expansionary for advanced countries.

Evolution of China's Economy and Monetary Policy: An Empirical Evaluation Using a TVP-VAR Model

  • Kim, Seewon
    • East Asian Economic Review
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    • v.25 no.1
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    • pp.73-97
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    • 2021
  • China has experienced many structural changes in the process of economic development over the past three decades. Using a time-varying parameter VAR model with stochastic volatility and mixture innovations, this study investigates whether such structural changes in, especially tools and operational aims of monetary policy, affect the monetary transmission mechanism. We find that impulse responses of output growth and inflation to monetary shocks have substantially increased and then reversed to decrease around 2005-2006. This time variation is mainly caused by changes in the monetary transmission mechanism, i.e., the manner in which main macroeconomic variables respond to policy shocks, rather than by changes in volatilities of exogenous shocks. The result implies that aggressive monetary policy to facilitate economic growth in the developing economies may be legitimized, unless it causes inflation seriously.

Structural Shocks of the Korean Economy: A Structural VAR Approach (통화(通貨)·물가(物價)·명목임금(名目賃金)의 장단기(長短期) 동학(動學)에 관한 연구(硏究))

  • Jun, Sung-in
    • KDI Journal of Economic Policy
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    • v.14 no.1
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    • pp.37-60
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    • 1992
  • This paper applies a Structural VAR approach to a 4 variable system in real GNP, M2, GNP deflator and nominal monthly earnings, disentangling 4 structural shocks, i.e., aggregate demand and supply shocks, wage pushes and various forms of regulations reinforced especially during stabilization process. Preliminary diagnostic tests confirm that the log level of each time series has at least one unit root, though the evidence is somewhat ambiguous for real GNP. One co-integration relationship is found among 4 variables, while no co-integration is found in a subsystem consisting of nomina) variables. The absence of co-integration among nominal variables strongly suggested that money is not neutral even in the long-run. The reduced form is estimated and the structural form is recovered using 6 additional identifying restrictions. Recovered structural shocks are able to capture main episodes of past 20 years, ranging from first and second oil shocks, to strong stabilization policy of early 80's and rapid wage hikes of late 80's. Overall responses of the economy to each structural shock are usually consistent with the standard Keynesian predictions, though some responses seem to be specific to Korean economic environment.

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Efficacy of the Rhinacanthus nasutus Nees Leaf Extract on Dermatophytes with Special Reference to Trichophyton mentagrophytes var. mentagrophytes and Microsporum canis

  • Darah, I.;Jain, K.
    • Natural Product Sciences
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    • v.7 no.4
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    • pp.114-119
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    • 2001
  • The effect of Rhinacanthus nasutus leaf extract on the growth of dermatophytes had been investigated. In vitro the extract exhibited high activity against various species of dermatophytes (Trichophyton mentagrophytes var. mentagrophytes, T. mentagrophytes var. interdigitale, T. rubrum, Microsporum canis and M. gypseum). The minimal inhibitory concentration (MIC) values of the extract revealed that all the dermatophytes tested had MIC values of 13.6 mg/ml. The extract exhibited fungistatic activity at lower concentrations $({\leq}13.6\;mg/ml\;or\;below\;the\;MIC\;value)$ and fungicidal activity at higher concentrations $({\geq}13.6\;mg/ml$\;or\;above\;the\;MIC\;value)$. The results suggested that the extract acted on the cell wall of the dermatophytes which subsequently leading to the formation of cytopathological and membrane structural degeneration and finally leading to cell lysis and death.

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Karyological Analysis of Somaclonal Variation in Callus Cells of Allium victorialis var. platyphyllum (산마늘의 캘러스세포에서 체세포군 변이의 핵학적 분석)

  • Seo, Bong-Bo
    • Journal of Plant Biology
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    • v.38 no.4
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    • pp.321-328
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    • 1995
  • Calli obtained from basal disc explants of Allium victorialis var.platyphyllum wre grown in three kinds of nutrient media (MS, BDS, and B5), and the frequencies of mitotic index and the chromosomal aberrations were analysed. The mitotic index varied from 0.55% to 1.01% with respect to culture media and ages. The mitotic irregularities like micro-, bi- and multi-nuclei, chromosome bridge and laggards were noted in each types of calli. The chromosome number variations observed in metaphase stage were identified aneuploid and tetraploid. Structural variations such as dicentric chromosomes, centromere breakage and small chromosomes were observed. Relationship between basal medium and chromosomal variability was not observed in this study. But, in BDS medium, NAA and BA had a more effect on number variation than kinetin.

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