Parameter Estimation of Switched Hammerstein Systems

This paper deals with the parameter estimation problem of the Single-Input-Single-Output (SISO) switched Hammerstein system. Suppose that the switching law is arbitrary but can be observed online. All subsystems are parameterized and the Recursive Least Squares (RLS) algorithm is applied to estimate their parameters. To overcome the difficulty caused by coupling of data from different subsystems, the concept "intrinsic switch" is introduced. Two cases are considered: i) The input is taken to be a sequence of independent identically distributed (i.i.d.) random variables when identification is the only purpose; ii) A diminishingly excited signal is superimposed on the control when the adaptive control law is given. The strong consistency of the estimates in both cases is established and a simulation example is given to verify the theoretical analysis.Comment: 16 pages, 3 figures; Accepted for publication by Acta Mathematicae Applicatae Sinica (http://link.springer.com/journal/10255

The impact of China's exports on global manufactures prices

This paper analyses the impact of China's exports on the prices of exports from other countries using disaggregated import data in the US, EU and Japan over the 1989-2006 period. Findings from this study suggest that China's exports have affected not just those countries whose competitiveness is largely based on low wages but all country groups in certain products sectors, destination markets and during different time periods. The middle income countries are the most affected by China's export expansion through price competition particularly after the late 1990s as a consequence of China's market expansion, its WTO entry and exchange rate variation. The influence on high-income countries is only in low-technology product sectors and appears to lose its significance in the post-1997 period. The impact on low-income countries is only significant in the medium- and high-tech sectors mostly in the pre-1997 period and this effect weakened over time

How does fiscal decentralization affect aggregate, national, and subnational government size?

Beyond conducting the usual regression analysis of the relationship between fiscal decentralization and aggregate government size (national and subnational combined), this paper makes the first attempt to examine how different fiscal decentralization measures affect the sizes of national and subnational (state and local combined) governments. An econometric analysis using panel data from 32 industrial and developing countries, 1980¨C1994, finds that (1) expenditure decentralization leads to smaller national governments, larger subnational governments, and larger aggregate governments; (2) revenue decentralization increases subnational governments by less than it reduces national governments, hence leads to smaller aggregate governments; and (3) vertical imbalance tends to increase the sizes of subnational, national, and aggregate governments.Fiscal decentralization, Size of government, Vertical imbalance, Borrowing constraints

Dynamical symmetries of the Klein-Gordon equation

The dynamical symmetries of the two-dimensional Klein-Gordon equations with equal scalar and vector potentials (ESVP) are studied. The dynamical symmetries are considered in the plane and the sphere respectively. The generators of the SO(3) group corresponding to the Coulomb potential, and the SU(2) group corresponding to the harmonic oscillator potential are derived. Moreover, the generators in the sphere construct the Higgs algebra. With the help of the Casimir operators, the energy levels of the Klein-Gordon systems are yielded naturally.Comment: 4

Fiscal decentralization, revenue and expenditure assignments, and growth in China

Theory suggests that a close match between revenue and expenditure assignments at sub-national levels benefits allocative efficiency, and hence economic growth. That is, a convergence of revenue and expenditure assignments at sub-national levels of government should, according to the theory, be positively associated with a higher growth rate. In the case of China, this paper shows, divergence, rather than convergence, in revenue and expenditures at the sub-national level of government is associated with higher rates of growth. A panel dataset for 30 provinces in China is used to examine the relationship between fiscal decentralization and economic growth over two phases of fiscal decentralization in China: (1) 1979¨C1993 under the fiscal contract system, and (2) 1994¨C1999 under the tax assignment system. The seeming contradiction between the theory and evidence in the China case is reconciled by taking into account the institutional arrangements that prevailed during the two phases of fiscal decentralization, in particular the inconsistency between the assumptions of the theory of fiscal decentralization and the institutional reality of China.Fiscal decentralization, Economic growth, Revenue, Expenditure

Substrate Envelope-Based Design of New Dipeptide Isostere Cores for the Development of Protease Inhibitors against Drug-Resistant HIV-1

Drug resistance is one of the major causes for HIV-infected patients to lose lives. An innovative HIV-1 protease inhibitor scaffold needs to be developed to resolve drug resistance issues. During this investigation, HIV-1 protease inhibitors based on a novel keto-hydroxyethylene core were designed and synthesized based on the substrate envelope theory. This core targets to overcome drug resistance to Amprenavir and Darunavir caused by I50V mutation in the protease. The results of florescence resonance energy transfer (FRET) assays indicate that the new inhibitor has moderate enzymatic inhibitory activities against HIV-1 protease. In the future, a variety of drug analogues will be developed based on this new core structure and might provide better therapies against drug-resistant HIV-1