A Statistical Scheme for the Seasonal Forecasting of North China's Surface Air Temperature during Winter

This paper presents a statistical scheme for the seasonal forecasting of North China's surface air temperature (NCSAT) during winter. Firstly, a prediction model for an decrease or increase of winter NCSAT is established, whose predictors are available for no later than the previous September, as this is the most favorable month for seasonal forecasting up to two months ahead.The predicted NCSAT is then derived as the sum of the predicted increment of NCSAT and the previous NCSAT. The scheme successfully predicts the interannual and the decadal variability of NCSAT. Additionally, the advantages of the prediction scheme are discussed.

EFFECTS OF VERTICAL WIND SHEAR ON TROPICAL CYCLONE INTENSITY CHANGE

The effects of vertical wind shear on tropical cyclone(TC) intensity change are examined based on the TC data from the China Meteorological Administration and the NCEP reanalysis daily data from 2001 to 2006.First,the influence of wind shear between different vertical levels and averages in different horizontal areas are compared.The results indicate that the effect of wind shear between 200 and 850 hPa averaged within a 200-800 km annulus on TC intensity change is larger than any other calculated vertical wind shear.High-latitude and intense TCs tend to be less sensitive to the effects of VWS than low-latitude and weak TCs.TCs experience time lags between the imposition of the shear and the weakening in TC intensity.A vertical shear of 8-9 m/s(9-10 m/s) would weaken TC intensity within 60 h(48 h).A vertical shear greater than 10 m/s would weaken TC intensity within 6 h.Finally,a statistical TC intensity prediction scheme is developed by using partial least squares regression,which produces skillful intensity forecasts when potential predictors include factors related to the vertical wind shear.Analysis of the standardized regression coefficients further confirms the obtained statistical results.

A Novel Data Embedding Method for H.264 Stereo Video Codec with Joint Prediction Scheme

It is important to reduce data redundancy of stereo video in practical applications. In this paper,first,a data embedding method for stereo video（DEMSV） is investigated by embedding the encoding data into the reference frame to encode stereo video. It can use only one channel to transfer all the video data and the receiver can choose a monocular video decoder or stereo video decoder adaptively. Then,introducing the joint prediction scheme in the coding process of DEMSV,we propose a novel data embedding method for H.264 stereo video codec with joint prediction scheme（DEMSV-JPS） to achieve high coding efficiency. Experimental results show that the proposed method can obtain high peak signal-to-noise ratio（PSNR） and compression ratio（at least 33 dB for the test sequence） . Comparing the testing methods using JPS and without using JPS,we prove that JPS can further improve the objective and visual quality. DEMSV-JPS shows such advantages and will be suitable to applications in real-time environments of stereo-video transmission.

Event-Triggered Consensus for Discrete-Time Multi-agent Systems with Parameter Uncertainties Based on a Predictive Control Scheme

In this paper,the event-triggered consensus for linear discrete-time multi-agent systems with parameter uncertainties is investigated.The parameter uncertainty is assumed to be normbounded.An event-triggered consensus protocol based on the predictive control method is proposed to make the multi-agent system achieve consensus.And for the design of the consensus protocol,the problem of estimating the control input is transformed into the problem of estimating state differences between agents.Furthermore,the event-triggered consensus protocol proposed in this paper only demands each agent to mornitor its state to determine its event-triggered instants.A sufficient existence condition for the consensus protocol is proposed based on the linear matrix inequality.And a sufficient condition for the nonexistence of the Zeno-like behaviour is also derived.Finally,a numerical example is given to illustrate that the event-triggered consensus protocol proposed in this paper can make the multi-agent system with parameter uncertainties achieve consensus effectively.

Optimized and coordinated model predictive control scheme for DFIGs with DC-based converter system

This paper proposes an optimized and coordinated model predictive control(MPC) scheme for doublyfed induction generators(DFIGs) with DC-based converter system to improve the efficiency and dynamic performance in DC grids. In this configuration, the stator and rotor of the DFIG are connected to the DC bus via voltage source converters, namely, a rotor side converter(RSC) and a stator side converter(SSC). Optimized trajectories for rotorflux and stator current are proposed to minimize Joule losses of the DFIG, which is particularly advantageous at low and moderate torque. The coordinated MPC scheme is applied to overcome the weaknesses of the field-oriented control technique in the rotor flux-oriented frame, which makes the rotor flux stable and the stator current track its reference closely and quickly. Lastly, simulations and experiments are carried out to validate the feasibility of the control scheme and to analyze the steady-state and dynamic performance of the DFIG.

A Fully Actuated System Approach for Stabilization of Discrete-Time Multiple-Input Nonlinear Systems with Distinct Input Delays

In this paper,the problem of stabilization is considered for discrete-time multiple-input nonlinear systems with distinct input delays law based on the fully actuated system approach.In order to compensate the input delays,a prediction scheme is presented to predict future states based on the closed-loop linear system.Then,a stabilizing law is constructed for nonlinear delayed systems by replacing the future states in the control law for the corresponding delay-free systems with their prediction.Finally,numerical examples are given to verify the effectiveness of the proposed approach.