Flap-lag-torsion aeroelastic stability of a circulation control rotor in forward flight

The aeroelastic stability of a circulation control rotor blade undergoing three degrees of motion (flap, lag, and torsion) is investigated in forward flight. Quasi-steady strip theory is used to evaluate the aerodynamics forces; and the airfoil characteristics are from data tables. The propulsive and the auxiliary power trims are calculated from vehicle and rotor equilibrium equations through the numerical integration of element forces in azimuth as well as in radial directions. The nonlinear time dependent periodic blade response is calculated using an iterative procedure based on Floquet theory. The periodic perturbation equations are solved for stability using Floquet transition matrix theory. The effects of several parameters on blade stability are examined, including advance ratio, collective pitch, thrust level, shaft tilt, structural stiffnesses variation, and propulsive and auxiliary power trims

A Note on Testing ¡°Tax-and-Spend, Spend-and-Tax or Fiscal Synchronization¡±: The Case of China

The hypothesis of tax-and-spend, spend-and-tax, or fiscal synchronization was tested using annual time series data for China over the period 1977 to 1999. We include GDP as a control variable into the model like Baghestani and Mcnown (1994), Koren and Stiassny (1998), and Chang et al. (2002). The results from Granger causality test based on the corresponding multivariate error-correction models (MVECM) suggest feedback between government revenues and government expenditures, supporting the fiscal synchronization hypothesis for China.

A REEXAMINATION OF SOUTH KOREA¡¯S AGGREGATE IMPORT DEMAND FUNCTION: THE BOUNDS TEST ANALYSIS

This paper uses a robust estimation method referred to as the unrestricted error correction model - the bounds test analysis to re-analyze the long-term relationships between the demand for imports and it¡¯s determinants for South Korea over the period 1980-2000. Our results show that the volume of imports, income, and relative prices are all cointegrated. The estimated long-run (short-run) elasticities of import demand with respect to income and relative price are 1.86 (0.86) and -0.2 (-0.05), respectively. The major implication of our study is that neither monetary nor fiscal policies may be used as instruments to maintain the trade balance in South Korea¡¯s favor during this sample period.Aggregate Import Demand Function, UECM, Bounds Test Analysis

REVISITING HYSTERESIS IN UNEMPLOYMENT FOR TEN EUROPEAN COUNTRIES: AN EMPIRICAL NOTE ON A MORE POWERFUL NONLINEAR (LOGISTIC) UNIT ROOT

In this empirical note we use a more powerful nonlinear (logistic) unit root test advanced by Leybourne et al. (1998) to investigate the hysteresis in unemployment for ten European countries for the period 1961-2003. The hypothesis is confirmed for all the European countries for which Leybourne et al.¡¯s (1998) nonlinear (logistic) unit root test is performed, except for Belgium and the UK.Hysteresis in Unemployment, European Countries, Logistic Unit Root Tests

Impact Analysis of Transportation Modal Shift on Regional Energy Consumption and Environmental Level: Focused on Electric Automobiles

Many governments have tried to reduce CO2 emissions which are believed to be the main cause for global warming. The deployment of electric automobiles is regarded as an effective way to reduce CO2 emissions. The Korean government has planned to deploy about 200,000 electric automobiles. The policy for the deployment of electric automobiles aims at not only decreasing gasoline consumption but also increasing electricity production. However, if an electricity consuming regions is not consistent with an electricity producing region, the policy generates environmental problems between regions. Hence, this paper has established the energy multi-region input-output model to specifically analyze the impacts of the deployment of electric automobiles on regional energy consumption and CO2 emissions. Finally, the paper suggests policy directions regarding the deployment of electric automobiles