In this paper, we attempted to entend the application of conditional nonlinear optimal perturbation(CNOP) optimization parameters in land surface model. We used common model and data Tongyu station,which is a reference site CEOP semi-arid regions, three key (soil color, soil sand/lay proportion leaf area index) as be optimized. Two experiments are designed our work, namely single-parameter triple-parameter optimization. Notable improvements simulating sensible heat flux (SH), latent (LH),...

In this paper, we explore the application of extended Fourier amplitude sensitivity test (EFAST) to land surface parameter analysis. Based on observations Tongyu site (Jilin province) at a degraded grassland in 2008, EFAST method is verified and applied. The sensible heat flux latent are used as variables. With full consideration individual parameters, coupling between parameters taken into account. We influence nonlinear system under constraints interaction multiple with quantitative...

Based on the data of monthly mean soil temperature from 722 stations over 1971-2000 and moisture observations 178 agrometeorological during 1981-1998,the long term trends in East China their relationship with change surface air precipitation are analyzed.The results indicate that:(1) There obvious regional differences variation The Northeast displays an increasing trend,while other parts China,such as North China,the Yangtse-Huaihe river Valley Southwest-South shows a trend dropping at first...

A study on tank gunnery motor skill training is introduced in this paper. We developed a two-mode system used for teaching and training. In the haptic guidance mode, trainee passive experiences position playback of expert's motion with proportional-derivation (PD) controller. path constraining operates device actively, aiming point virtual environment constrained desired path. new rendering algorithm mode. An experiment record-play drawing sine an envelope designed. Results indicate that stable.

Model simulations show that land use and cover changes(LUCC) may alter surface energy budget influence microclimate, but up to now, it still lacks of sufficient observations for explaining the mechanism climate change brought about by LUCC. Grasslands shrub lands are typical covers in mid-latitude arid zone northern hemisphere. The data used this paper was collected from four sites which related grassland, open shrubland, savanna closed all located New Mexico, USA. near each other have same...

摘要: 计算平面机构自由度的契贝谢夫-克鲁伯(Grübler-Kutzbach)经典公式看似简单,但使用起来却经常出错。在对现行多数《机械原理》和《机械设计基础》等教材中关于平面机构自由度计算中存在问题进行深入分析的基础上,也可得到相似的结论。为此提出一种计算平面机构自由度的新方法,并对相应的Grübler-Kutzbach公式进行变异。即通过引入实约束高副、虚约束高副、全约束低副和半约束低副等新概念,解决了目前在平面机构自由度计算中存在的问题,为平面机构自由度计算的严谨性和科学性进行了有益的探索。

With a new scheme of effective roughness length for heterogeneous terrain, based on the atmospheric boundary layer Monin-Obukhov similarity theory as well flux and mass conservation principles, statistical features its sensitivity to stratification stability step three surface category case are investigated. The results show that is greater than area-weighted logarithmic average one drag coefficient more 10% in most cases. much sensitive step, though it dependent stability, relative...

A scaled boundary finite element method is developed for the analysis of hydrodynamic pressures acting on arch dam faces with a reservoir irregular geometry. Water compressibility and absorption are considered simultaneously. The idealized as composed infinite subdomains. Governing equations evaluating fluid domain have been established solution procedures presented. In addition, conditions at interface between subdomains decided. Numerical examples validate present high accuracy show that...

Analysis of the influence cascading failure in power grid was presented based on electric-structure-load entropy, by observing initial load entropy and variation process to get effecting it's inhibition spread. Load can effectively quantify imbalance between transmission lines distribution state, considering circuit equations Kirchhoffs law, Power structure characteristics lines, reflect self-organized criticality grid. Numeric example IEEE 118-bus system shows at beginning failure, estimate...

In this study, a novel gas-extruded membrane bearing was developed, and an optimization algorithm applied to solve Reynolds equation that describes the load-bearing characteristics of bearing. This effective in improving solution rate equation, significantly reducing difficulty obtaining solution, avoiding high programming difficulty, achieving accuracy. Through comparative analysis, error accuracy alternating implicit difference method addressed, traditional finite element for solving same...

Traditional switching operations require on-site work, and the high voltage generated by arc discharges can pose a risk of injury to operator. Therefore, combination visual servo robot control is used localize operation construct hand–eye calibration equations. The solution equations coupled with rotation matrix translation vectors, it depends on initial value determination. This article presents convex relaxation global optimization algorithm based dual quaternions. Firstly, problem model...

In this paper, we investigate the statistical features of influences local zero-plane displacement on effective roughness length and for three surface categories, with a so-called joint calculation scheme aerodynamic parameters over heterogeneous terrain proposed by Zhong et al. [Zhong Z, Lu W, Song S Zhang Y 2011 J. Hydrometeor. 12 1610]. The is found to magnify length. However, such magnification effect tends decrease as step increases. On other hand, increases increasing, though it always...