Abstract:Coupled identification is an important branch of system identification and is a new identification concept which is used mainly to study identification problems of linear and nonlinear multivariable systems with complex structures and parameter coupling.The auxiliary model identification idea,the multi-innovation identification theory,the hierarchical identification principle,and the coupled identification concept are new identification research ideas,concepts and methods and can be used to study identification problems of systems with unknown process variables,to improve the convergence rates and accuracies of identification methods,to solve identification problems of large-scale multivariable systems with complex structures and of multivariable systems with parameter coupling,reducing the computational load of the identification algorithms.This paper introduces the coupled identification concept of multivariable systems,discusses the(full) coupled least squares identification methods,the(full) coupled stochastic gradient identification methods,the partially coupled stochastic gradient identification methods,the partially coupled least squares identification methods etc for multivariable systems.Finally,we show that the coupled identification methods can be applied to multivariable systems with colored noises,list some model structures of some multivariable systems,and indicate that the coupled identification concept can combine the auxiliary model identification idea,the multi-innovation identification theory,the hierarchical identification principle,the iterative search principle(the gradient iteration,the least squares iteration,the Newton iteration) to study identification problems of linear and nonlinear multivariable systems with colored noises.

Abstract:This work concerns the stability for a class of impulsive Cohen-Grossberg neural networks with time-varying delays,reaction-diffusion and Neumann boundary condition.By means of the impulsive integral inequality of Gronwall-Bellman type and piecewise continuous Lyapunov functions as well as Neumann eigenvalue problem,we summarize some new and concise sufficient conditions ensuring the global exponential stability of the equilibrium point.Moreover,the provided stability criteria are shown to be associated with both reaction-diffusion and time delays.An illustrative example is finally given to demonstrate the effectiveness of our obtained results.

Abstract:As a neural network based on MSSE,ANN-MSE is not an appropriate solution to the problem of predicting rare weather event.In this paper,an improved neural network method,ANN-CE is presented,which is a three layered back-propagation neural network with one output unit.The error function of ANN-CE is a cross entropy function.Then utilizing ECMWF forecast fields data,this method was applied to 96 hours forecast of heavy precipitation event in northern Fijian province.The ANN-CE model and the ANN-MSE model based on original factor and principle component after PCA reducing dimensions were respectively built.These models were applied to independent samples in 2009-2010,and the test results are as following:TS grade for model based on principal component is higher than that of model based on original factors;miss-rate for the ANN-CE model is lower than that of the ANN-MSE model.All in all,ANN-CE model based on principal component has best performance and stability,whose TS grade and miss-rate was respectively 0.51 and 0.17,so it was suited for forecasting rare event.

Abstract:Agro-ecosystem is one of the terrestrial ecosystems under the intensive control and interference by human activities,the estimation on carbon source or sink of agro-ecosystem has become a study focus in the field of global carbon cycle studies.Direct and continuous long-term measurements of carbon fluxes over grassland ecosystem have become possible due to the improvement of eddy covariance method.This paper summarizes the research progresses of carbon flux over agro-ecosystem based on the eddy covariance method in China,and gives emphasis to the research results on the temporal variation characteristics,driving mechanism and model simulation of carbon flux over agro-ecosystem.Based on the research,the paper also offers some suggestions on the study of carbon flux over agro-ecosystem in China,and points out that long-term observation and study,multi-factor cooperative function,model development and scaling,data quality control and assessment should be the key research directions.

Abstract:Based on the meteorological data from 147 stations over the Yangtze River basin,climatology computational method was used to estimate global solar radiation.For a better understanding of spatial-temporal variations of global solar radiation over the Yangtze River basin since 1960,and the impact of the cloud cover and the atmospheric water vapour on the global solar radiation,linear regression and correlation analysis methods were used.The main results are as follows:Global solar radiation over the Yangtze River basin except for the Jinsha River basin decreases from east to west with fluctuant change in the upstream region and significant decrease in the downstream region.The decreasing trend in global solar radiation did not persist into the 1990s which coincided with the "global dimming" and "global brightening".The cloud cover and the atmospheric water vapour content are not the primary causes for the decrease in global solar radiation over the Yangtze River basin.

Abstract:Water vapor is a kind of greenhouse gas which has more powerful greenhouse effect than carbon dioxide.It supplies hydroxyl radicals to photochemical reaction in stratosphere.When the water vapor condensed into ices,the ozone will be consumed more quickly because the ices can supply heterogeneous interface to chemical reaction.The vertical transport by deep convective overshoot is one of the most important sources of stratospheric water vapor,thus the research of deep convective overshoot transporting water vapor into stratosphere can provide reference for climate change research.Some advances of water vapor vertical transport by deep convections are collected in the study,including evidences of water vapor injects into stratosphere,detection methods of deep convective overshoot,mechanism and influence factors of water vapor vertical transport.And some possible prospects are discussed in the end.

Abstract:The monitoring data of Jiangsu Provincial Lightning Positioning System from 2006 to 2009 are used to analyze the characteristics of lightning activity in Nanjing.It is found that,most of the lightning happens at 12-20 P.M.in June-August and few happens in other months,because the convective activities frequently happen in summer in Nanjing and in the period of the midday to sunset,due to the always high temperature,which is easy to produce strong convective thunderstorm;The average density of lightning striking the earth is between 2-6 times/(km²·a) in most Nanjing area,and the maximum center is in Jiangning district.The average lightning strike intensity is between 5-40 kA,and the maximum center is near Nanjing Yangtze River Bridge,where the intensity is 75 kA or more.Topography,land surface properties,moisture conditions and other factors may be the main reason leading to the above characteristics.The lightning activity characteristics and lightning parameters obtained in this study are valuable in the lightning protection,lightning risk assessment and other areas.

Abstract:Port hopping is a new type of information hiding technology emerged in recent years,and it has very prosperous development and application prospect in the network covert communication.The port hopping technology features the non-fixed sending and receiving ports,which hop randomly and simultaneously in communication.Compared to the traditional communication with fixed port,the communication using the port hopping technology makes it difficult to discover the port of communication,and even if the port is discovered by the enemy,the communication has already been transferred to another port.Therefore the port hopping is more covert than the traditional technology,and communication using it is difficult to be intercepted.This paper analyzes the basic principles and key technologies of the port hopping,carries on modeling analysis on the port hopping process,and assesses theoretically the system security through the models of the port security,the system availability and the system confidentiality.On this basis,by the use of Windows Sockets technology and VC+ + programming,it designs and implements the session-based port hopping system.Experiment results show that the system successfully makes the data packets diffuse in the background noise of network through the port hopping technology,and effectively reduces the hacker attacks in view of the specific port.At the same time the viability of the system is improved compared with that of the fixed port system.

Abstract:This paper introduces the basic principle of Cyclic Redundancy Check(CRC) and the form of generating polynomial,analyzes the generating polynomial and hardware description of CRC-8-Dallas/Maxim and CRC-16-IBM in embedded system.In the case study of the data checking of ROM ID/Scratchpad of DS18B20 device and the bus network data frame checking of Modbus,through analyzing and researching into the generating polynomial and hardware description,the paper gets a basic bit-to-bit check algorithm design,then obtains an advanced bit-to-bit check algorithm and a single byte and a half byte table lookup check algorithm on the basis of mathematical derivation.In order to improve check speed,this paper proposes a new method based on block and multi-table checking algorithm.Comparison in ROM space occupancy and processing speed is carried out among all the above check algorithms.The designed CRC program provides support for the reliable transmission of embedded system data.

Abstract:A dynamic self-adaptive threshold segmentation algorithm based on human visual attention theory and maximum between-class variance method is proposed.First of all,the pending image is divided into lots of equal-sized square blocks,then the feature value of every block is calculated respectively according to multi-scale visual attention.Secondly,all the image blocks are divided into two types by classification algorithm based on feature value of visual attention.Finally,blocks with different types are binarized by maximum variance algorithm and multi-scale adaptive threshold algorithm respectively.The experimental results show that:compared with the one dimension maximum variance and two dimension maximum variance segmentation methods,this new proposed method can eliminate the disturbance of the uneven lighting and background noises,thus achieve superior segmented results for uneven lighting and poor quality document image binarization.These experimental results testify the validity and practical value of the proposed method.

Abstract:Since 1800,M≥7 strong earthquakes have showed an obvious commensurability and orderliness in Xinjiang and its neighbourhood region.The main orderly values are 30 a×k(k=1,2,3),11-12 a,41-43 a and 18-19 a.According to the information forecasting theory of WENG Wenbo and complex network technology,we try to explore the practical methods for M≥7 strong earthquake prediction with Chinese characteristics,and build the informational ordered network structure of M≥7 strong eatthquakes in Xinjiang.In this paper,the activity rhythm of M≥7 strong earthquakes in Xinjiang during the past 200 years is revealed fully by the network structure.Based on this,Yutian M7.3 strong earthquake is successfully predicted in 2008.At last,we present a new prediction opinion that the future M≥7 strong earthquakes will probably happen in 2014-2015,2019-2020 and 2026 in this region.The results show that strong earthquake can be predicted.This method produces satisfactory results for mid-and-long strong earthquake prediction.

Abstract:According to the three axioms in the buffer operator theory,several new weakening buffer operators with variable weights were constructed,and the relationship between buffer operator regulation degree and variable weight were studied in this paper.The new operators solve the problem of unsatisfactory buffer effect due to the lack of fine tuning of effect intensity.An example was given to show the flexibility and validity of the new operators in controlling strenghth.

Abstract:The Bernoulli and Euler numbers are important classical numbers and have wide applications in mathematics and physics.By applying the formal power series method to some elementary trigonometric identities,we establish several arithmetic identities involving Bernoulli and Euler numbers.