Study on least square modeling of heat engineering object based on typical signal response

This paper proposes a kind of least square modeling method based on typical signal response to enhance modeling accuracy of heat engineering process and adapts the environment that modeling experiment conditions are limited. The principle of this method is, under the condition of known typical pulse, step and slope signal response and model structure, to give algorithm of model parameters of identified continuous system by least square mode through derivation. The method is applied to the identification of heat exchange process for a consumer substation, and identification result obtained is compared with that of other conventional methods. After the comparison the result shows that identification accuracy is improved obviously. In addition to the good identification accuracy, this method has the characteristics such as it can identify directly continuous system model, pure lagging time, and is not sensitive to data length in the identification process. All these characteristics show that this method is simple, easy to implement and has good practicability.

Reflecting a single attosecond pulse by using periodic Mo/Si multilayer mirrors with different layers

The reflecting of a single attosecond pulse from a periodic Mo/Si multilayer was investigated. By changing the number of bi-layers, the periodic multilayer showed greatly different spectral and temporal responses of the attosecond pulse reflection, which has been discussed in detail in this paper. The capability of attosecond pulse reflection of the periodic multilayers with different bi-layer numbers has been evaluated using suitable temporal parameters. In addition, the condition for obtaining high-efficiency reflected pulses has been analyzed by comparing the pulse responses of the periodic multilayer with different layers. The transfer-matrix method together with the fast Fourier transform has been used in our simulation.

Empirical Analysis on Effect of Agricultural Financial Investment on Increase of Farmers' Income

On the basis of economic data from 1978 to 2006,the co-integration theory is applied to discuss the relation between agricultural financial investment and farmers' income.The statistic AR model is obtained.Then,it makes pulse response analysis in combination with principle of pulse response analysis.The regression results show that support in agricultural production,various agricultural operating expenses and three types of costs for agricultural science and technology are favorable to farmers' income,while expenditure in agricultural capital construction and rural relief costs hinder increase of farmers' income.The results of pulse response analysis indicate that the change in support of agricultural production and various agricultural operating expenses have positive impact on farmers' net income,and the impact is greater and greater from the second year;the response of expenditure in agricultural capital construction and rural relief cost is positive in the beginning and starts to fluctuate from the third year;the pulse response of three types of costs for agricultural science and technology is negative,lasts about five periods,and then turns to positive impact.Finally,combining characteristics of China's financial support for agriculture,it concludes that the scale,proportion and structure of financial support for agriculture are quite improper.

Dynamic Relation between Rural Human Capital and Farmers'Income in Henan Province

We use relevant economic and labor force data from 1990 to 2009 of Henan Province to analyze the dynamic relation between stock of rural human capital and farmers' income.Results indicate that a certain causal relationship and long-run equilibrium relation exist between rural human capital and farmers' income,but their interaction shows some lagging characteristic.Increase of farmers' income in Henan Province increases the stock of rural human capital in this province for a short term.However,in the long run,this accumulation effect will decline along with renewal and aging of knowledge.The positive promotion action of rural human capital on farmers' income will appear after a long lag time.Therefore,the policy of strengthening rural human capital input should be long-term and continuous.

MIMO-OFDM channel estimation method utilizing correlation in time domain for B3G-TDD uplink

This article proposes a simple pilot-aided channel estimation method based on correlation in time domain for multiple-input and multiple-output olthogonal frequency division multiplexing （MIMO-OFDM） systems. Pilot symbols in all transmit antennas are generated from different circular shifting of a certain sequence. Through once correlation, the receiver can obtain time-domain pulse responses for channel fading from all transmit antennas to a certain receive antenna, from which channel estimation in frequency domain can be obtained. Beyond 3G time-division duplex （B3G-TDD） uplink is introduced, and the channel estimation method is used in it. Theoretical analysis and simulation are both carried out. Mean square error （MSE） performance shows that the method can exhibit precise estimation. Complexity analysis proves it requires very low complexity. System simulation result shows that it guarantees the performance of B3G-TDD uplink very well.