Abstract:For input nonlinear output-error systems with known bases,this paper presents the over-parameterization model based auxiliary model (AM) recursive identification methods,the over-parameterization model based AM hierarchical identification methods,the key term separation based AM recursive identification methods,the key term separation based AM two-stage recursive identification methods,the key term separation based AM three-stage recursive identification methods,the bilinear-in-parameter model decomposition based AM stochastic gradient identification methods and the bilinear-in-parameter model decomposition based AM recursive least squares identification methods.Finally,the computational efficiency and the computational steps of several typical identification algorithms are discussed.The convergence of the proposed algorithms needs further study.

Abstract:PageRank assigns authority weights to each web page based on the web hyperlink structure,while the personalized PageRank is a generalized version of ordinary PageRank.The computation of personalized PageRank vector in unweighted web is well studied in the past decades,but little is known for the case of weighted webs.In this paper,we analyze the algorithms for PageRank computations in static as well as dynamic weighted networks.The algorithms are based on matrix transformation or Monte Carlo methods,and are analyzed theoretically for computation performance.Experiments show that the proposed localized algorithm outperforms power iteration and a referenced Monte Carlo method.

Abstract:In order to find out the propagation characteristics of lightning wave in coaxial cable,the transit response theory of coaxial cable was used to figure out the transit response to the 1.2/50 μs lightning wave.Besides,the related experiment was carried out under the help of lightning current generator.The research results show:the terminal signals of the coaxial cable are determined by both features of signal frequency and terminal impedance;the high-order modes are caused by the refraction and reflection of lightning wave and its excitation when the terminal is opened;the high-order modes excited by lightning wave mainly concentrate on the wave front because of the influence of the lightning wave spectrum;the final waveform at the terminal is the sum of all the high-order modes,and the lower of the lightning wave front the less of the high-order mode.The distortion of the lightning wave should be considered when propagating in coaxial cable,which has significance in guiding the suppression methods of overvoltage in coaxial line.

Abstract:Atmospheric pollutants including NO_x,O₃ and PM_2.5,along with meteorological factors were intensively monitored in Luhuitou village of Sanya,which is the southernmost tip of Hainan Island,in order to study the characteristics of air pollution in Sanya.Located in the outskirt of Sanya,the monitoring station is surrounded by sea in three directions and without industrial pollution sources.From December of 2011 to April of 2013,the variation properties of NO_x,O₃ and PM_2.5 in winter and spring were analyzed and the sources of pollutants were investigated using backward trajectory method.The results show that,the concentrations of air pollutants in Sanya were under the values listed as first level in national standard,with the daily average value of NO,NO₂,NO_x,O₃,and PM_2.5 being (2.1±2.2),(5.2±3.4),(7.3±3.8),(59.8±28.4),and (17.5±14.3)μg·m^-3,respectively.The diurnal variations of NO_x and PM_2.5 showed double-peak patterns,with the maximum concentrations appeared at 08:00 BJ (Beijing time) and 17:00 BJ;while the diurnal variation of O₃ exhibited a single peak which occurred at 13:00 BJ.Based on backward trajectory method,it was found that pollutants in Sanya came from local and regional sources,and the continental air mass usually led to accumulation of air pollutants,whereas the marine air masses usually diluted the air pollution.

Abstract:The summer rainfall series (June to September) in the Haihe River basin from 1800 A.D.to 2012 A.D.are reconstructed by statistic method,using data of the observed precipitation and the dryness and wetness grades in modern times.The quantified reconstruction of historical precipitation,with its feasibility and reliability areintroduced,and the time series of the reconstructed data are analyzed in this paper.The results show that the summer rainfall is always fluctuating and there are 13 shift terms in the basin during 1800-2012.Summer rainfall is generally less in the 20th century compared with that inthe 19th century,and the decreasing trend is most obvious in the last 100 years and the last 60 years.The 1880s-1890s is the moistest period,while the 1990s-2010s is the driest period.Power spectrum and wavelet analysis also show that the summer rainfall during 1800-2012 is characterized by inter-annual and inter-decadal oscillations with 2-8 a,10-15 a,22 a,25-30 a,quasi-35 a,and quasi-55 a period,and the long period oscillations are shortened in the 20 century.

Abstract:To assess the simulation effects of MPAS with icosahedral mesh and WRF with latitude-longitude mesh in global modes,thesimulated vorticity,precipitation,height and temperature from thesetwo models in China from October 23,2010 to October 28,2010 were compared.Results show that both the MPAS and WRF simulate the vorticity at 500 hPa with good effects under 30 km and 60 km resolutions,yet none of them can accuratelysimulatethe extreme value centers of vorticity.From the simulation results of the accumulated precipitation at the 4th day,both the MPAS and WRF can simulate the rainfall distribution,and MPAS is superior to WRF in general simulation result,while WRF is superior to MPAS in precipitation value centers simulation.MPAS works well for height and temperature fields at upper level;while WRF is good for those at middle and low level,and long in forecast validity period than MPAS.The increase of mesh resolution improves the simulation effect of WRF,and affects little on MPAS simulation.

Abstract:Diagnostic analysis is done on a heavy storm process occurred on July 5th,2012 in Henan province,based on data of NCEP,satellite image,radar echo,sounding and ground observation from regional stations,in order to reveal the characteristics and mechanism of regional heavy storms.The results show that the low level shear line interacts with the ground shear line and the surface mesoscale convergence line to produce the heavy rainstorm,under the influence of trough and subtropical high.Mesoscale characteristics analysis reveals good indicators of this strong precipitation process,including the cold air movement,the deep southwest jet stream of troposphere,the formation and development of mesoscale convergence and shear line.The distribution and intensity of vertical helicity at 700 hPa are in agreement with the rainfall area and center.The research results provide reference for the improvement of regional rainstorm forecast.

Abstract:The variation of urban heat island (UHI) effect in Jining of Shandong province was analyzed using meteorological measurements such as mean air temperature,mean wind speed,precipitation,cloud cover and visibility data from Jining,Yanzhou,Jiaxiang and Wenshang station at 02:00,08:00,14:00,and 20:00 BST from 1981 to 2013.Results show that the UHI effect in Jining has obvious monthly and diurnal variation characteristics.The UHI effect was stronger in the winter half year than in the summer half year;significantly weaker in daytime than in nighttime,and the weakest at noon.As for seasonal variation,the UHI effect in Jining is strongest in winter and weakest in summer,and in a slowly growing trend in seasons of spring,summer and winter.The UHI effect varies greatly under different weather conditions,which is most obvious at sunny windless weather with average value of 0.79 ℃,and least obvious at rainy weather with average value of 0.09 ℃.Fog and wind with speed equal to or greater than 4.0 m/s mostly occur in autumn or winter,but fog effects greater than wind on the formation and diurnal variation of UHI.As for the diurnal variation,the UHI effect is strongest at different time of a day under different weather conditions,which occurs at 02:00,20:00,and 08:00 at sunny windless foggy weather,precipitation weather,and strong windy weather conditions,respectively;while the UHI effect is weakest at 14:00 under all weather conditions.

Abstract:The analytical hierarchy process (AHP) is frequently employed to determine the element weights in study of regional lightning vulnerability zoning.However,the scholar's individual bias in judgment of option weight during AHP will introduce error to lightning risk assessment model.In order to avoid the potential error brought by AHP,we use principal component analysis instead to establish a new type of lightning disaster vulnerability zoning model,which is then applied to analyze the lightning disaster vulnerability in Hainan province.Five indexes,including thunderstrike density,lightning frequency,economic loss,life vulnerability module,and casualties frequency are chosen to zone Hainan province in lightning vulnerability.

Abstract:In an enterprise network,usually there are hundreds of branches,all of which need secure and reliable communications.As a highly scalable IPSec VPN solution under the network circumstance,DM VPN is used to deploylarge-scale VPN tunnel to encrypt the communication between corporate network branches.The proposed dual center dual cloud DM VPN directlyencrypts the communication in the branch networkwithout the forward process by the network center,which canreduce the cost and improves the networksecurity for medium or small scale enterprises.

Abstract:In this paper,three independent ³He-rich solar energetic particle (SEP) events during the solar minimum from May 2007 to January 2010 were identified using ACE/ULEIS data.The observations of the twin satellites,STEREO-A and B,indicate that the longitudinal distribution of these energetic electrons originated from the minor flare induced SEP events might be extended to about 130 degree.On the assumption that the heliographic transportation accounts for the longitudinal distribution,calculations show that,here exists a magnificent difference in the longitude transport speed of the electron carrying waves,and these electrons moves faster to east than to west from the active particle source.

Abstract:The molecular structure optimization of Freon C₂Cl₂F₄ (F-114) and infrared (IR) spectra were obtained by density functional theory (B3LYP/6-31G++(d,p)) calculations,and the calculated IR spectra are in good agreement with experimental results.Additionally,the excited state and low ionic excited states of Freon C₂Cl₂F₄ were calculated by performing ab initio calculations with CIS method.The obtained bond length,bond angle and dihedral angle for the low molecular excited states are compared and analyzed.Meanwhile,UV-Vis spectra and molecular frontier orbits for the C₂Cl₂F₄ are obtained.Finally,the photodissociation dynamics of the low ionic excited states of the ionic cation C₂Cl₂F₄⁺ are discussed.

Abstract:This paper considers the controllability of a class of fractional hybrid stochastic functional differential equations.In infinite dimension space,by using measure of noncompact and Mönch fixed point theorem,the sufficient conditions of controllability of the equations are obtained under the assumption that the semigroup generated by the linear part of the equations is not compact.Finally,an example is given to illustrate the effectiveness of the result.