Model Construction and Visualization Simulation of Soybean Root System

This paper mainly focused on the growth law, model construction and visualization of a soybean root. A pot experiment was conducted in the laboratory to collect root system data and measure soybean root’s length, diameter and number by excavating in different periods. On the basis of an in-depth analysis of root structure geometry, we analyzed the collected experimental data with logistic equations, and got the growth of soybean root equation, according to its morphological structure characteristics of self-similarity, and discussed the virtual modeling method on the soybean root based on L-system and in Visual c++ Using OpenGL technology to achieve a soybean root system topology model and visualization simulation.     

REALIZATION OF GPS／SST／SINS INTEGRATED NAVIGATION FILTER ALGORITHM FOR BALLISTIC MISSILE

Considering the domestic single navigation system of the ballistic missile, a new filter method is presented. The method integrates the information of the strapdown star tracker (SST) attitude, the position and the velocity of a high speed GPS with a strapdown inertial navigation system (SINS) information into one filter, thus improving the precision of the attitude, the velocity, and the position. Finally, the GPS/SST/SINS simulation platfornt is designed. Simulation results demonstrate that the filter is robust and reliable, and the precision rises to the comparative level abroad.     

A Rice Growth Models (RGM) System by Object-Oriented Programming with Visual C ++

Object-oriented programming divides the crop production into subsystems and simulates their behaviors. Many classes were designed to simulate the behaviors of different parts or different physiological processes in crop production system. At the same time, many classes have to be employed for bettering user‘s interface. But how to manage these classes on a higher level to cooperate them into a perfect system is another problem to study. The Rice Growth Models (RGM) system represents an effort to define and implement a framework to manage these classes. In RGM system, the classes were organized into the model-document-view architecture to separate the domain models, data management and user interface. A single document with multiple views interface frame window was adopted in RGM. In the architectures, the simulation models only exchange data with documents while documents act as intermediacies between simulation models and interfaces.Views get data from documents and show the results to users. The classes for the different functions can be grouped into different architectures. Different architectures communicate with each other through documents.The classes for the different functions can be grouped into different architectures. By using the architecture,communication between classes is more efficient. Modeler can add classes in architectures or other architectures to extend the system without having to change system structure, which is useful for construction and maintenance of agricultural system models.     

MULTI-FUNCTION VEHICLE NAVIGATION AND MONITORING SYSTEM IN URBAN AREAS

A vehicle navigation and monitoring system integrated by a high precision navigation system and a vehicle black box is studied to satisfy the demand for the intelligent transportation system (ITS). Firstly, the architecture of the system is proposed. Then the integration scheme of global positioning system/dead reckoning/bluetooth beacon/map matching (GPS/DR/BB/MM) with the hluetooth assistant positioning technology, and the algorithm of the Kalman filter for the integrated GPS/DR are investigated. Finally many field trials for principle prototypes are made. Experimental results show that the proposed integrated navigation algorithm is effective and feasible, and the function of the vehicle black-box is realized.     

Application of Pruning Algorithm on Voice Service Platform of Cow Disease Diagnosis Expert System

Expert System （ES） is considered effective and efficient in agricultural production, as agricultural informationization becomes a main trend in agricultural development. ES, however, is applied unsatisfactorily in most rural areas of China and it has considerably affected and restricted the development of the agricultural informationization. This paper proposed a solution to voice service system of ES, which was suitable for the information transmission, and it especially could help the peasants in remote regions obtain knowledge from ES through the voice service system. As for the disadvantages of massive knowledge data and slow deduction, in this system the classification method could be adopted based on the decision tree. Designing pruning algorithm to ＂trim off＂ the unrelated knowledge to the users in query course would simplify the structure of the decision tree and accelerate the speed of deduction before the inference engine deduced the knowledge required by users.     

A Computer Method of Steady Non—Uniform Gradually Varied Flow in Open Channel ＆ in River

Most of water flow in open channel or in river belongs to steady non-uniform flow.The surface profiles are caused by changes of channel section.It is very important to analyze its computation.According to the regularity of its surface cange,the suitable sectional dimensions of open channel or flood control work can be designed.Commonly,computation of non-uniform flow adopts the traditional methods by hand or by graphic method.The speed and precision of computation are restricted.In this paper,a software to calculate water surface profile is introduced.The software is put forward by using C^ .By means of interpolate method and dialogue between user and computer,we can calculate the water surface profile much more quickly and exactly.     

藏北高原草地生态系统研究进展(英文)

With the aggravation of global change, the response and adaptation of the unique ecosystem in Qinghai-Tibet Plateau to global change have been increasingly concerned by scientific community day by day, which makes the sensitivity and fragility of this ecosystem in response to global change widely recognized by scholars. On the basis of introducing the present research process on the degenerate mechanisim, measures of and approaches to recovery, carbon cycle and primary productivity toward global change, we put forward several propositions on studying the alpine grassland ecosystem in Northern Tibetan Plateau.     

Contribution of Adventitious Roots to Water Use Strategy of Juniperus sabina in a Semiarid Area of China

duniperus sabina Linnaeus, an evergreen shrub with prostrate life form, can effectively prevent sand moving and is an important tree species for reforestation in semiarid areas of China. It has laterally distributed adventitious roots and a deeply distributed main root system. To detect water movement between the main root system and adventitious roots, we adopted heat pulse sensors using the Heat Ratio Method, a high precision method for measuring low sap flow rates. Two sensors were implanted in each individual in the stem between the main root system and adventitious roots, and another two in lateral stems distal to all the roots. Positive sap flows during nighttime, even under saturated air moisture conditions, were detected only between the main root system and adventitious roots under drought conditions, and the rate of flow increased as drought progressed and decreased or disappeared after rain events. The results demonstrated the existence of water movement from the main root system to adventitious roots, and combined with the high contribution of nighttime sap flow to transpiration （11%-16%） the results indicate that it also involves the process of hydraulic lift, a water movement from moist subsoil to dry surface soils. Integrated water use strategy between the main root system and adventitious roots via the process of hydraulic lift of soil water maximizes water acquisition efficiency from both subsoil water and water from rain pulses on the soil surface; this increases survivability in the water-limited environment of semiarid areas.     

流域不透水面及其变化信息提取(英文)

Impervious surface is one of the important parameters of valley water circular simulation,scientific estimation for which has significant and practical value for the urban water quantity and process simulation,diffuse pollution estimating and the forecast of climate changes.The objective of this research is to get the information of impervious surface and its dynamic change.Through the computer-assisted field method,the technologies of decision tree and data mining were applied to withdraw the impervious surface information in research region by the Landsat TM data in 1988,1994 and 2002.The results suggested that the accuracy of impervious surface information extraction in the study area arrived above 94.4% in 2002 image.On this basis,the mixed method was used to extract the location and the types of the impervious surface change.The overall accuracy of monitoring reached 89%,which meets the demand of the hydrological models.     

Optimization of Spray Drying Processing Technology of Mulberry Powder

With concentrated juice of mulberry as raw material, the influence of type and dosage of dry aid, the inlet air temperature, inlet flow rate, and rotating speed on spray drying was studied. The spray drying processing conditions of mulberry powder were optimized by the L9(34) orthogonal test on the basis of single factor experiment. The results showed that optimum technical parameters to produce mulberry powder were: β-cyclodextrin as dry aids with dosage of 30%, inlet air temperature of180 ℃, rotating speed of 18 000 r/min and inlet flow rate of 30 m L/min. The mulberry powder under this optimum process conditions had a loose structure and bright color, fruity flavor was rich, the anthocyanin content for 54.67 mg/g, moisture content for5.6% and sensory scores for 83.     

实时交通信息下基于抽象路网结构的交通均衡

由于现实世界的复杂性和人为因素的不可控性,交通系统的最优交通配流难以实现.多数交通系统运行在用户最优原则下.通过基于多智能体交通微观仿真技术在3种不同抽象路网中的仿真研究,得出如下结论:不论在交通系统中是否植入实时交通信息系统(RTTIS),系统都能够建立近似交通用户均衡.在这些均衡状态中,在平行路网中RTTIS的植入,恶化了交通系统的运行,车辆平均速度降低50%;在网格状和环状路网中其植入却使交通效率得到了优化,车辆平均速度分别提高33%和71%.RTTIS能够将交通系统从某一用户均衡状态转换到新的用户均衡状态,在这个过程中系统效率可能得到提高也可能变坏,这依赖不同的交通网络结构.     

绿色的视觉交通廊道——宣广高速宣城东出入口地段景观设计

通过对宣广高速宣城东出入口地段景观设计方案的阐述,传达了从规划到建成使用全过程对个人驾乘体验的设计思想。在考虑道路建设及养护的经济性的同时,使司机、乘客及沿线居民有心理上的舒适、行车的安全感,并考虑保护动植物的生态平衡。     

城市滨水地区交通组织策略研究

在当代滨水慢行活动与机动交通共存并进的背景下,二者的组织方式深切影响着滨水地区的长远发展.滨水地区的道路规划必须综合分析道路的交通、景观功能,并从道路平、纵、横三个方面,以及按照道路的空间、组合和艺术美的要求来规划设计,力图将城市滨水地区的道路规划建设成为最能体现出城市形象的精品.     

Traffic signals and depth perception

Automobiles approaching red traffic signals at night appear to go beyond them when viewed from some distance to the rear. The phenomenon is doubly illusory because the higher of two objects has been presumed to appear more distant. The illusion is probably limited to small visual angles (about 2 degrees).     

网络流量自相似性影响因素的研究

网络流量特征是分析和研究网络性能、规划网络建设的基础.由于自相似模型能够更加真实地描述网络传输的特性,通过生成自相似性的流量进行仿真研究,提出将业务源流量自相似性与网络传输的TCP协议相结合进行研究的方法,探讨影响自相似流量的因素,分析网络行为随参数变化的情况.仿真结果表明业务源流量的自相似与网络状态无关,而网络传输的TCP协议自适应改变网络状态,从而间接改变网络流量的自相似性,但并不能消除业务源流量的自相似性.     

网络流量监测技术

网络流量监测技术对网络流量行为描述、网络规划、设计和管理提供基本依据,对网络运行的QoS保证和网络安全也产生很大影响.基于路由的网络流量监测技术(RMON、Net Flow、SFlow)以及基于非路由的网络流量监测技术(主动测量和被动测量),分析对比各种监测技术的性能,在此基础上探讨当前两种最新的组合网络流量监测技术: SCNM与WREN.     

节约能耗的固定道耕作法

介绍了固定道耕作法及其目前的研究情况。利用测力数据采集系统,在免耕和已耕地条件下,对凿形开沟器在压实区和非压实种床区开沟所需水平牵引力和牵引功率进行了同步测量。试验结果表明,在本试验条件下,采用固定道耕作法开沟器所需牵引力可降低40％左右。     

交通事故预测方法研究

交通事故预测是在对已发生事故的数据进行统计、分析和处理的基础上,以事故发生原因和发生的规律为依据,对目前尚未发生的事故预先做出的推测、判断。介绍了几种主要的公路交通事故预测方法,包括线性回归预测法、非线性回归预测法、时间序列预测法的移动平均法与指数平滑预测法、灰色马尔科夫链预测法、基于车速的交通事故贝叶斯预测法、道路交通事故的灰关联分析及神经网络预测方法等,国内、外传统的和主流的交通事故预测的方法,并对几种主要的公路交通事故预测方法的适用条件、优缺点进行了较详细的比较,为相关部门选择合适的交通事故预测方法提供参考。     

自相似网络流量预测研究

研究发现,网络流量自相似特性具有普遍性,且不随缓冲、交换、传输和延迟而改变,网络流量预测必须考虑这种自相似特性.本文从自相似网络流量的多个方面对现有研究成果进行了分析,从网络自相似的模型、参数估计、性能预测等多个方面对网络自相似流量预测研究进展进行了总结,并提出了一种基于测量的流量自相似等价带宽预测算法.分析表明:该算法能有效地减少计算量和降低实现复杂度.