Hopf bifurcation of nonlinear system with multisource stochastic factors

The article mainly explores the Hopf bifurcation of a kind of nonlinear system with Gaussian white noise excitation and bounded random parameter.Firstly,the nonlinear system with multisource stochastic fac-tors is reduced to an equivalent deterministic nonlinear system by the sequential orthogonal decomposi-tion method and the Karhunen-Loeve(K-L)decomposition theory.Secondly,the critical conditions about the Hopf bifurcation of the equivalent deterministic system are obtained.At the same time the influence of multisource stochastic factors on the Hopf bifurcation for the proposed system is explored.Finally,the theorical results are verified by the numerical simulations.

Overview of Stochastic Vehicle Routing Problems

Stochastic vehicle routing problems ( VRPs) play important roles in logistics, though they have not been studied systematically yet. The paper summaries the definition, properties and classification of stochastic VRPs, makes further discussion about two strategies in stochastic VRPs, and at last overviews dynamic and stochastic VRPs.

Calibrating partial factors for Danish railway embankments using probabilistic analyses

High costs are connected with upgrading railway embankments throughout Denmark using the partial factors for geotechnical design calibrated for general application. One way to reduce the costs is reliability-based calibration of the partial factors to a reasonable safety level taking into account the specific design situations and uncertainties relevant to railway embankments. A reliability-based design has been investigated, resulting in an optimal partial factor for the considered subsoil. With a stochastic soil model to simulate the undrained shear strength of soft soil deposits, the partial factor is calibrated using asymptotic sampling for the reliability assessment. The calibration shows that the partial factor can be reduced significantly compared to the value specified in the Danish National Annex to DS/EN 1997-1 （2007）, Eurocode 7.

China's Optimal Industrial Structure:Theoretical Model and Econometric Estimation

With analysis of producer's and factor supplier's dual optimization motives,this paper developed an optimal nominal output growth rate model that can conduct quantified estimation.Result of estimation of China's optimal industrial structure between1992 and 2009 indicates that optimal nominal output growth rate model has successfully quantified the impact of major events occurring in the process of China's economic operation on the level of deviation between actual industrial structure and optimal industrial structure.Quantitative indicators involved in this model can provide industrial policy instruments for the Chinese government in developing and adjusting industrial structure targets,optimizing resource allocation and advancing industrial structure optimization and upgrade.

Quasi-variable Discount Rates and Market Volatility: An Empirical Study

This paper proposes an assumption of quasi-variable discount rates to explain the excess volatility puzzle of stock market. Under the assumption, the ARMAX model is derived based on the CCAPM model and CRRA utility function to describe the linear relationship between the discount rate and the consumption growth rate. We conducted empirical research on this model using historical data of the US stock market. The results confirm a significantly negative relationship between consumption growth rate and discount rate. Subsequently, the results of Monte Carlo simulation show that given the risk preference coefficient and dividend sequence, the rational expectations price fluctuation obtained under the assumption of quasivariable discount rate is the largest.