Application of Fundamental Formula for Matrix Function in Solution of Circuit Transient Respond

In this paper, the fundamental formula of matrix function is discussed. The author puts forward a new method of solution of two-rank linear transient respond, using the fundamental formula of matrix function. The method can be spread and applied to solution process of high rank linear circuit transient respond and is superior to that of traditional solution.     

Modeling and Simulation of the Doubly Fed Generatorwith the Matrix AC-AC Converter as an Exciter

According to the space vector modulation method of the AC DC AC converter,the switch control scheme of the matrix AC AC converter is deduced,and the model of a three phase matrix AC AC converter is constructed. According to the mathematic model of the doubly fed generator and the excitation control principle based on dynamical synchronous reference frame,the simulation model of the generator and excitation controller are established,then the modeling and simulation of the doubly fed generator system with the matrix AC AC converter as an exciter are implemented.The steady state and transient characteristics of the system are simulated,the harmonics of the EMF and stator?rotor current are researched.     

Similar Boundary Element Method in Elastodynamics

For the boundary element method of elastodynamics, some properties of matrices are discussed in case of similar boundary elements and the similar boundary element method is presented. In a series of similar boundary elements, when the corresponding matrices of a boundary element are obtained, the ones of other boundary elements in the series can be obtained by proportion. Then the coefficient matrix of the last system of linear algebraic equations can be obtained by the method of superposition. Compared with the general boundary element method, the computing speed can be raised by the similar boundary element method given in this paper.     

Application of the WK Mixed Filter Algorithms in the Processing of Radar Information

The Kalman filter algorithms can not solve the problem of the time-frequency localization, and it often switches between the low-frequency filter and high-frequency filter by the mobile detector (The changeable dimension filter algorithms) or Markovian transfer probability matrix (VD algorithms), so it has delay and some influence of the the mobile detector and Markovian transfer probability matrix. Hence, the filter error of the Kalman filter algorithms is obviously big. This paper brings the new mixed filter algorithms (WK algorithms) of the 2D Wavelet transform and Kalman Filter, which has the characteristics of the well time-frequency localization and real-time. The WK algorithms is used to process the radar information and makes the filter estimated data to approach the true track.     

CropSyst, a cropping systems simulation model

CropSyst is a multi-year, multi-crop, daily time step cropping systems simulation model developed to serve as an analytical tool to study the effect of climate, soils, and management on cropping systems productivity and the environment. CropSyst simulates the soil water and nitrogen budgets, crop growth and development, crop yield, residue production and decomposition, soil erosion by water, and salinity. The development of CropSyst started in the early 1990s, evolving to a suite of programs including a cropping systems simulator (CropSyst), a weather generator (ClimGen), GIS-CropSyst cooperator program (ArcCS), a watershed model (CropSyst Watershed), and several miscellaneous utility programs. CropSyst and associated programs can be downloaded free of charge over the Internet. One key feature of CropSyst is the implementation of a generic crop simulator that enables the simulation of both yearly and multi-year crops and crop rotations via a single set of parameters. Simulations can last a fraction of a year to hundreds of years. The model has been evaluated in many world locations by comparing model estimates to data collected in field experiments. CropSyst has been applied to perform risk and economic analyses of scenarios involving different cropping systems, management options, and soil and climatic conditions. An extensive list of references related to model development, evaluation, and application is provided.     

Multi channel cortical stimulator based on FPGA

A FPGA based multi channel cortical stimulator system for cortical visual prosthesis was designed. devised for generating a sequence of electrical pulses for cortical stimulation. The simulator is composed of a FPGA and voltage/current converters. The FPGA comprises a spike generator to generate various electrical pulse sequences and some multiplexers to select signals. The prototype based on an Altera Cyclone EP1C6 FPGA with four channels is developed to perform the experimental evaluation. Two electrode chips ane put out of the left and right dura of cortex of a cat. The electrical stimulation is connected to the left one, while the visual electrically evoked potential (EEP) is recorded by the right one. The experimental results on cat's cortex show that the cortex can respond to the current stimulation.     

A GROUP-DIVIDING SYNTHEIS METHOD FOR SIX-BAR PLANER MECHANISM''DRIVEN BY PNEUMATIC/HYDRATIC DRIVING SYSTEM

The paper employs the combination of the group-dividing synthesis and optimum method to establish the synthesis method used in which the type stepheson six-bar planer mechanism is used as the function generator which is driven by a pneumatic/hydraulic cylinder. The linear superposition technique is used in the whole solving process and the number of the design positions is not limited by the unknown parameters.     

Overall control strategy and operational performances of a doubly fed wind turbine generator system

In order to comprehensively and correctly analyze the real-time operational characteristics of a grid-connected wind turbine generator system, it is necessary to analyze the overall control strategies and operation performances of the wind turbine generator system. According to the type of a doubly fed wind turbine generator system, the mathematical models of wind turbine, drive train and doubly fed induction generator (DFIG) are presented. From the viewpoints of the maximum wind energy capture and safe operation of the wind turbine, a maximum power output control strategy is proposed by considering the DFIG loss minimization, and a variable pitch control strategy is also presented by considering generator rotational speed restriction and the output power restriction. Combined with a power decoupling strategy of DFIG, the overall operational performances of the doubly fed wind turbine generator system are simulated. By comparing the simulation, theoretical analysis and actual operational data, the results show that the presented model and overall control strategies of the doubly fed wind turbine generator system are valid.     

An analysis hierarchy model application in computer aided alignment

To obtain the most important influence factors in road route selection quickly and effectively, we put forward a method that we call an analytic hierarchy process. In this method, we first use a matrix to show the mutual relationships of factors. We then analyze and calculate the matrix. Finally, we obtain the relative importance of all factors in the overall system. The result derived using this method is more reasonable and more direct viewing to reflect influence coefficient. And based on the firsthand information of designs and the social background, the method can give qualitative indicators before program design, which prevented blindness of designing process and the designer can get more suitable road lines.     

基于web的农产品安全生产组态软件

提出了以SVG作为监控图片格式,Ajax作为客户端与服务器通信机制构建基于Web的农产品安全生产图形组态软件的方法。详细介绍了系统的整体结构,系统的主要功能模块的设计及具体实现,并介绍了系统实现过程中的关键技术。农产品安全生产组态软件不仅可以实现农产品生产过程的实时监控,而且还为生产预警提供依据。     

On line tool breakage monitoring method based on power information and cross-correlation algorithm

In order to reliably monitor unexpected tool failure and prevent workpiece or machine tool from possible damages in batch machining, a tool breakage on-line monitoring method based on power information and cross-correlation algorithm is proposed. In this method, wavelet coefficients of spindle-power signal are used as the characteristic vector of machining information, and then the vector sequence extracted from a normal machining process via Mallat wavelet is defined as the reference template for monitoring cutting tool condition. In batch machining, real-time characteristic vector of the workpiece in machining process is extracted via an improved real-time wavelet algorithm. The correlation of two vector sub-sequences within a sampling time window, which is described by generalized cross-correlation coefficient, decreases apparently when the tool is broken. The generalized cross-correlation coefficient is defined as tool condition index (TCI), and tool breakage can be detected by monitoring the TCI with a threshold value. Experiments show that the method can accurately identify tool breakage failures in normal machining condition, and thus it is practical.     

中红外光谱技术在土壤环境研究中的进展综述

土壤是农林业生产的基础,高效、全面地获取土壤信息对于土壤管理意义重大。由于土壤有机组分较为复杂,采用传统的化学分析方法难以全面地获取土壤有机组分信息。中红外光谱(MIR)分析技术作为一种无损、实时、高通量的分析手段,具备高效、准确地获取土壤有机环境信息的能力,可为土壤环境监测、数字制图、农林业生产提供大量基础数据,有助于实现土壤环境实时监测和农林业信息化。笔者简述了中红外光谱技术获取土壤环境光谱信息的检测过程和光谱数据处理方法,综述了近年来国内外学者在土壤中红外光谱特征提取、影响因素等方面的研究进展,并针对该技术深入研究土壤学的意义及未来的发展方向进行了讨论。     

基于GIS的广西暴雨灾害风险实时评估技术研究

为了科学应对广西暴雨灾害频发、影响日趋严重这一问题,选用广西自动站实时降雨量数据、历年暴雨灾情数据、广西社会经济数据及基础地理数据,采用主成分分析法、层次分析法等方法,结合GIS技术,研究了暴雨灾害危险度实时评估的技术方法,并基于暴雨灾害实时危险度、孕灾环境脆弱度、承灾体易损度和抗灾力等4个因子,构建了广西农业暴雨灾害风险度实时评估模型,选择2011年的一次暴雨过程对模型进行验证,验证结果表明：评估结果与实际灾情较为吻合,模型实践检验效果较好。     

Real-Time Strategies for the Fire Alarm Information System Based on Internet

According to the reality of the development of fire alarm system in our country, this paper offers a fire alarm information system based on Internet. Being different with the way of normal router in transmitting all data packages fairly, a new dispatch algorithm is put forward, which can identify different data packages of demanding different real-time performance and transmit the data packages of demanding high real-time performance by jumping queue intelligently. That decreases warning time delay and improves the dependability of important data transmitted by router. A new kind of method is proposed to satisfy a high real-time system at a low cost.     

非线性方程最优拟合的缩张算法

本文提出一种可实现非线性方程最优拟合的新方法－缩张算法（Ｃ－Ｅ算法）。该算法由若干循环组成,每一循环都包含收缩和扩张两个步骤。因而,可以在多维起始空间的内、外漫游搜索目标函数,并利用搜索过程所反馈的信息调整搜索中心和步长;通过较少次Ｃ－Ｅ循环的搜索,便能逼近给定非线性方程的最适参数值。该算法不需要给出方程的导数或偏导数,减少了计算的复杂性,也可能推广应用于解决其它目标函数的最优化问题。     

A calculation method for coalbed permeability by using drainage data

In order to more accurately calculate the changes in the permeability of coalbed during production process, a calculation method for coalbed permeability based on production data is established by combining with material balance equations and production equations, and it gives the fact that the output data can be a good reflection of the inner permeability of coalbed. The average pressure of coalbed in production process can be calculated through material balance equation. Dimensionless water production index is introduced into the production equation in the stage only with water production. In the next stage with both gas and water, gas and water production ratio is introduced to eliminate the influence of flush-flow radius, skin factor as well as other uncertain factors on the calculation of CBM permeability. The relationship between permeability and surface cumulative liquid production can be described as a single-variable cubic equation by derivation. There is a trend that the permeability declines firstly and then increases after wells in Qinshui CBM field are calculated. The results show that reservoir permeability increase after drainage stage, but the growth rate decrease gradually. The regression result of the permeability ratio and surface cumulative fluid production agrees with the theoretical mathematic relationship.     

荧光定量PCR技术在猪病毒病诊断上的应用

摘要：荧光定量PCR技术融汇了传统PCR技术灵敏、快速、特异的特点以及光谱技术的高敏感性和高精确定量的优点,以直接探测PCR过程中荧光信号的变化获得定量的结果。因其具有特异性强、灵敏度高、重复性好、定量准确、速度快、全封闭反应等优点,为动物疫病诊断技术提供了新的模式,成为当前动物疫病检测广泛采用的分子生物学诊断技术。论文就实时荧光定量PCR技术在猪瘟、猪繁殖与呼吸综合症、猪圆环、猪流感等猪病毒病检测上的应用作一综述,以期为猪病毒病的防控提供参考。     

Reconstruction on Real-time Data Platform for Production Command Dispatch System

Production command system plays a more and more important role in the modern large scale production. Being limited to realizing technology tool,there is a lot loss in information that is very valuable in the production process.Even it is not stored to the real key data information used for reflecting production sate, therefore it is very difficult to command and dispatch the production correctly. Reconstruction platform related to real-time database is discussed. Taking the background of iron steel industry,based on the analyzing the function characteristic of real-time data requirement of real-time data platform,the paper is explored to the real-time database selecting strategy and so on.     

Manufacturing resource modeling of complexassembly process under project-based manufacturing

In an engineering-to-order (ETO) company, organization and management of manufacturing process is differ from common products because of the complexity of product. A project-based manufacturing (PM) planning model for product final assembly is proposed based on single-piece and small-batch production model so that the characteristics of complexity, specificity and high complex product manufacturing process can be met by means of projected-based manufacturing. The method of layered network planning under project-based manufacturing can transform the objects of planning from parts to assembly cell in the course of final assembly that has some time-based buffer for planning; simultaneously a resource-task matrix is build for the whole assembly process. The matrix can achieve the relatedness between manufacturing resources and assembly task, and follow the resources loads in order to realize the matching of planning and resource against project product.     

THE CALCULATION OF THE LNS INDEX OF LARGE GENERATORS USING PIECEWISE ALGORITHM BY CAPACITIES

If generator capacity were not graded, the error in reliability evaluation would increase along with the large-capacity generators put into use.In this paper, the method for calculating LNS Index of generators is analyzed and studied using piecewise "algorithm by capacity, it can be used in reliability evaluating of unspecified under loaded generators.