Abstract:The input nonlinear systems include the input nonlinear equation-error type systems and the input nonlinear output-error type systems.According to the over-parameterization model,the key term separation and the data filtering,this paper studies and presents the over-parameterization model based auxiliary model recursive identification (AM-RI) methods,the key term separation based AM-RI methods and the data filtering based AM-RI methods for input nonlinear output-error autoregressive systems.These methods can be extended to other input nonlinear output-error systems,output nonlinear output-error type systems and feedback nonlinear systems.Finally,the computational efficiency,the computational steps and the flowcharts of several typical identification algorithms are discussed.

Abstract:The daily precipitation in Chongqing during 1961-2012 observed by 34 meteorological stations were used to analyze the precipitation characteristics in temporal and spatial distribution,frequency and intensity by applying methods of EOF,linear regression and correlation analysis.The results indicate that the annual total precipitation of Chongqing is gradually decreasing.There are two patterns for the spatial distribution of annual total precipitation,namely,pattern of wet or dry in all area,and pattern of wet (or dry) in northeast with dry (or wet) in other areas of Chongqing.There are big differences in annual total frequency distribution for different duration precipitations.Linear trends show that short duration(2-day) precipitation processes are increasing,while long-duration(5-day and more) precipitation processes are decreasing in frequency.The reduction of annual total rainfall by general precipitations(including light rain,moderate rain,and heavy rain) may be the main reason for the decrease of annual total precipitation in Chongqing;the light rain and moderate rain are decreasing,but the heavy rain is increasing slightly in intensity.While the annual total rainfall by heavy precipitation processes (storm,heavy storm) is weakly increased,with slightly enhanced precipitation intensity.The decreased frequency of long duration(5-d and more) precipitation processes may be related to the rising trend of 500 hPa geopotential height in Chongqing region and the increment of equatorial Pacific sea surface temperature,while the slight increase in precipitation intensity of heavy rain and storm may be due to the El Niño Modoki.

Abstract:The hourly observational data from 6 regular meteorological stations and 2 island stations in Hainan Island are used to statistically analyze the temporal and spatial characteristics of near-surface wind over the coastal areas of the Hainan Island during 2012,indexes including the distribution of wind speed and its daily change,and wind direction frequency.The results show that the yearly averaged wind speed over coastal areas is from 1.8 m/s to 5.7 m/s,with the highest wind speed appearing in Sanya,especially in winter with possible wind speed of 6.5 m/s.Generally,the highest wind speed usually appears in winter or spring over most coastal stations,while the weakest wind appears in summer;the wind speed is higher in southern than in northern areas,and higher in western than in eastern coastal areas.The diurnal evolution of wind speed exhibits the canonical pattern,with high speed in daytime and low speed in nighttime;however,Sanya exhibits the opposite pattern in wind speed as a result of its unique topography and vegetation.The dominant wind direction is south or southwest in summer and north or northeast in winter,which is similar to the pattern of South China Sea Monsoon.The seasonal variability of prevailing wind is significant over southern coastal areas,followed by eastern and western regions,and not obvious over northern coastal areas.

Abstract:PM_2.5 samples were collected in Sanming,Fujian province from March 13 to April 20,2014.The mass concentrations were determined and the chemical characteristics were analyzed by thermal optical carbon analyzer and ion chromatography.During the observation period in Sanming city,the average mass concentration of PM_2.5 was 73.61±0.73 μg/m³.The averaged value of organic and elemental carbon were respectively 7.26±1.00 and 5.63±0.27μg/m³,and the mass concentration fraction of four ions,including SO₄^2-(18.08±12.19μg/m³),NH₄⁺(4.18±3.56 μg/m³),NO₃^-(2.77±1.16 μg/m³) and Na⁺(2.73±0.23 μg/m³),accounted for 87.76% of total water-soluble ions.Moreover,backward trajectory analysis indicated that the major pollution sources were located to the southeast of Sanming.The average ratio of OC to EC was 1.89,which is less than 2,indicating that there was little SOC production in atmospheric fine particles in Sanming city,while the primary organic pollutants were dominating the PM_2.5 pollution.The correlation between K⁺ and OC,EC demonstrated that OC,EC have the similar source with K⁺,therefore we concluded that the primarysource of pollutants was biomass burning.The mean result of NO₃^-/SO₄^2- was 0.159±0.02,indicating that stationary sources were the dominated contributor whilemobile sources such as motor vehicle contributedmuch less.

Abstract:Through the atmospheric electric field data of 17 typical thunderstorm processes around Shenzhen recorded from June to Septemberof 2012,in combination with the lightning position data,we found very importantrelationship between the electrified variation and lightning strike occurrence.The amplitude of the electric field increases quickly accompanied bydithering when the thunderstorm cloud comes close to field instrument stations.The relationship between the electric field and the lightning stroke occurrence is 0-1,that is,when the electric field reaches and maintains a certain threshold for some time,the possibility of lightning is great in protection zone(within 10 km from electricfield station).Therefore,according to the characteristics of the atmospheric electric field waveform,predictors highly correlated with lightning are chosen,and a forecasting equation is established using multiple regression techniques.According to the equation,when the atmospheric electric field reachesthe threshold of 0.86 kV/m and maintains that value for a continuing of 10.73 minutes accompanied by electric field dithering,it can bepredicted that the lightning will occur within the range of 10 km from the station,with accuracy as high as 53%.

Abstract:The 594 years lightning disaster records span from 1420 to 2014 for the Palace Museum and the lightning location data over the Palace Museum and its surrounding region from 2005 to 2014 were counted and analyzed.The results show that a total of 51 lightning disasters were recorded for the Palace Museum,mainly occurred during May to September,especially from June to August,and August is the month which has most lightning disasters.The southern buildings and the buildings located at the central axis are more prone to lightning compared with the northern buildings and the buildings located at east or west wing of the Palace Museum,and the Supreme Harmony Palace has the most lightning disasters.The ridge animal statues,which are at the top of the ancient building,are most vulnerable to lightning strokes.In addition,the direct lightning strokes caused most lightning disaster losses.The lightning location data show that the lightning activities mainly occur during April to October,especially from June to August,and August is the month which has most lightning activities.A distinctive diurnal variation exists in lightning activities over the Palace Museum and the surrounding region within 1km range,and afternoon till midnight is the most vulnerable period with 63.95% of lightning occurrence.Generally,the lightning currents distributed normally with 30-40 kA as center,which accounted for 23.26%.The lightning activities and lightning disasters are roughly consistent in temporal distribution.

Abstract:Hunan Provincial Meteorological Bureau has established the first remote high performance computing environment in Hunan province,thanks for the National Supercomputing Center in Changsha.In aspects of building the remote computing environment,this paper analyzes Hunan Provincial Meteorological Bureau's requirements for high performance computing,and its calculation requirement in meteorological service.This paper focuses on the system architecture,and the technical routes and methods on establishment of a remote computing environment with a high performance computer cluster (Tianhe-1) as the computing resource.Furthermore,give consideration to both the powerful computing capabilities of the remote computing environment and the complicated requirements for the meteorological service at provincial level,we design the corresponding system process of the remote high-performance job schedule system,and the multi-level solutions to ensure the high speed and stability of remote computing environment.Finally,we run the small-scale WRF model in the remote high performance computing environment,and the results are improved obviously in calculation speed and calculation resolution,compared with that of the previously used computer cluster.

Abstract:In China,more and more fishes were polluted by waterborne heavy metal.Four sizes of tilapia were cultured to different Cd exposure in order to study the influence of heavy metal concentration as well as the fish size on the Cd accumulation and transfer by the Orechromis niloticus.The median lethal Cd concentration (LC₅₀),Cd accumulation and transfer rate in fish and relative growth rate of the fish are analyzed.The results show that different age of tilapia had different response to Cd contamination.LC₅₀ in the juvenile fish was the lowest while that in 31.5±3.4 cm length fish was the highest.Exposed to low Cd²⁺ concentration (0.5 mg/kg),different size of fishes accumulated significantly different (P<0.05) quantity of Cd²⁺ in the same tissue.While exposed to high Cd²⁺ concentration,the Cd²⁺ accumulation in different size of fishes had no obvious difference.The Cd²⁺ transfer factor was significantly greater in low Cd²⁺ concentration than that in high Cd²⁺ concentration,for all fishes except fish with 27.4±2.9 cm length.High Cd²⁺ concentration inhibits the fish weight increase more than low Cd²⁺ concentration,in all age of fishes.In addition,different Cd²⁺ concentration had different effect on the same age of tilapia.In conclusion,both the fish size of tilapia and the Cd²⁺ concentration affected the Cd²⁺ accumulation and transfer in fish.

Abstract:Nowadays,with the increasing competition between banks,it is very important to improve the bank's competitiveness by effectively excavating potential clients and providing differentiated services.The decision tree algorithm is proposed to data mine the possible 21 important attributes which affect bank clients' long-term deposit subscription.A Portuguese retail bank is addressed,with data collected from May,2008 to November,2010.The decision tree model is constructed to reflect the important factors in a banking client deposit subscription business.Results show that the significant factors which affect client's long-term deposit subscription are target number of bank agents,marketing duration and month.Such knowledge greatly reduces the marketing range of potential clients for term deposit thus improves the bank efficiency.

Abstract:In this paper,we consider the positive solutions for a class of three-point singular boundary value systems with a p-Laplacian operator under integral boundary condition.By using the fixed point theorem,under appropriate conditions,we establish the sufficient conditions for the existence of positive solution about this class of boundary value problem,and give two examples to illustrate our results.

Abstract:A Halin graph is a plane graph G=T∪C,where T is a plane tree with no vertex of degree two and at least one vertex of degree three or more,C is a cycle connecting the endvertices of T in the cyclic order determined by the embedding of T.In this paper,we discuss the star chromatic number,the face chromatic number and the fractional chromatic number of Halin graphs.