abstract recharge of aquifers by using wastewater, is one of the important and applicable ways for reusing this valuable water resource, especially in arid and semi-arid regions. as the necessity of local practices for finding the proper management strategies and optimum use of recharge systems (conforming to climate, soil, etc.), a preliminary study was carried out. three physical models were ...

This paper develops a price structure for providing reactive power service and control based on optimal power flow (OPF) approach. The cost of reactive power support service is determined based on capability and contributions to the improvement of system performance such as security, reliability and economics, by computing sensitivity of objective function with respect to reactive power support...

Real economic data always present nonlinear properties such as asymmetry and radically change in the series through time. Missing data and jumps as well as breaks also common reported in economic time series model. Thus, linear models are no longer suitable used in estimate the economic data and markov switching vector autoregressive model (MS-VAR) is applied in study the economic model. This p...

Conventional VAR (Value at Risk) estimation includes historical simulation, variance/covariance, and the Monte Carlo simulation method. This study is the first to present a hybrid method of estimating VAR, combining ARMA and Neural Network. Empirical results demonstrate that the hybrid method obtained superior results to the conventional method in estimating VAR. In terms of accuracy, both the ...

One of the main concerns of investors is the evaluation of the return on investment, which is conducted using various models such as the CAPM (single-factor model), Fama-French three/five-factor models, and Roy and Shijin’s six-factor model and other models known as multi-factor models. Despite the widespread use of these models, their major drawbacks include sensitivity to unexpected changes, ...

In this paper, we investigate the statistical properties of the waiting times between two successive price changes above a fixed threshold (or a fixed point) for the indices of Shanghai Stock Exchange and Shenzhen Stock Exchange. The database is from the indices of Shanghai and Shenzhen in the 10-year period from January 1997 to December 2006, and the empirical research shows that the distribut...