基于ANP-SVR的驾驶员能力预测模型设计

基于Prescan仿真平台搭建的驾驶场景,搭建了人机交互式的驾驶仿真系统进行数据采集实验,计算了驾驶能力判断中各评价指标因素的权重。通过ANP-SVR算法建立了驾驶能力预测模型,模型精度高,可以为实时驾驶能力预测的研究进行铺垫。基于熵权法计算驾驶风险度,通过比较驾驶风险度与驾驶能力评估的数据,得出数据的一致性,验证了ANP算法应用于驾驶员能力评估的可行性。     

根系吸水模型参数的混合遗传算法估算方法

构建了遗传算法与Levenberg-Marquardt算法相结合的混合遗传算法,用于求解根系吸水模型参数.分别进行数值试验和棉花根系吸水试验对混合遗传算法求解精度进行验证.数值试验表明,采用混合遗传算法优化求解根系吸水模型参数的优化值具有较高的精度,含水率资料的时间步长和空间步长对根系吸水模型参数的优化精度有较大影响,在实际中时间步长可取值5～10 d,空间步长取值5～10 cm.对室内棉花根系吸水进行模拟分析,结果表明混合遗传算法求解的根系吸水模型可以很好地模拟根系吸水.该方法可用于求解根系吸水参数.     

乔灌篱沟蓄沟道土壤水分运动数值模

在分析乔灌篱沟蓄沟道布置和水分运动特点的基础上,建立了乔灌篱沟蓄沟道二维非饱和土壤水分运动模型,采用Galerkin有限单元法对方程进行数值求解.室内验证试验结果表明,土壤含水率和湿润锋的模型计算值与实测值吻合较好,说明乔灌篱沟蓄沟道土壤水分运动模型正确,采用有限元法求解可行.     

离散小波变换在水文序列分解中的

运用Mallat算法和Daubechies小波，对水文序列进行离散小波变换的方法。通过离散小波变换，将水文序列分解成不同时间尺度的确定性序列和随机序列，为运用各种确定性模型和随机模型建立水文中长期耦合预报模型打下了基础。以长江寸滩站日平均流量和北碚站7月最大洪峰流量序列为例，进行了小波变换。通过对分解后的序列进行重构表明，结果是满意的。     

Gains from crop diversification in the Sudan Gezira scheme

Land allocation in Gezira irrigation scheme (the Gezira) has, for the most part, been based on the political judgement of the government rather than economic criteria. This paper determined optimum crop combinations for the Gezira using the mean-variance (M-V) model. This large-scale gravity-irrigated project which was started for export cotton cultivation on 27,372 feddan (11,496 ha) in 1927 has now expanded to over two million feddan, and has a multi crop production system. Sources of production uncertainty include government control of prices, often announced after planting, and crop area in favor of cotton. Diversification was analyzed under various levels of risk using, in contrast to what is in the reviewed literature, both cross sectional and time series farm level data. The cross-sectional data comprised of net farm returns of 100 farmers for the 1987/1988 season, and the time series data were average net farm returns from the same area from 1971 to 1988. Cropping decisions in the Gezira are mostly based on cross-sectional data from a sample of tenants in the preceding season. This paper estimated variance and covariance parameters of observed net margins of both sets of data and found significant differences in the results. The certainty equivalence results used to evaluate crop diversification showed that current policies of controlling crop acreage lead to inefficient land use; and that farmers diversify into wheat and groundnuts out of cotton when cross-section data were used; and from groundnuts to cotton and wheat when time series data were used.     

面向夹持机构的紧凑型串联弹性力控驱动器设计与试验

串联弹性驱动器力控性能优异,在机器人无损抓持应用领域具有较好的应用前景。设计一种集成伺服电机、弹性元件、编码器等部件的高度紧凑型串联弹性驱动器。采用试验手段对串联弹性驱动器进行模型辨识,获得控制角度轨迹与驱动力观测模型,并通过PD控制器实现力控。通过刚性与超弹性物体力控加载试验,研究串联弹性驱动器力控响应与误差特性。通过物体自适应抓持与人机交互试验分析串联弹性驱动器力控自适应抓持与外力自感知特性。试验结果表明,串联弹性驱动器对刚性物体加载控制较快,力控稳态时间约0.35s,且无超调出现。由于超弹性物体变形迟滞特性,其力控响应时间显著高于刚性物体。串联弹性驱动器力控模式能够实现物体自适应抓持,且抓持力度与速度可调。串联弹性驱动器可在不依赖指尖力传感器的情况下实现抓持力感知,有利于简化硬件与控制系统。     

不同入渗水头条件下土壤水分运动数值模拟

在分析入渗水头对土壤水分入渗影响的基础上,提出了分层计算假定,建立了不同入渗水头作用下土壤水分运动数学模型,并采用差分法进行求解.在室内进行了不同入渗水头土壤水分入渗验证试验,结果表明,模型计算土壤含水率与试验实测值具有较高一致性,最大相对误差为4.8％,表明所建立的不同入渗水头作用下土壤水分运动数学模型是正确的,求解方法是可行的.     

横流风机与离心风机串联特性的试验

在大量试验的基础上,分析了横流风机与离心风机串联时总排气性能与单机排气性能的关系。把2种风机串联时的流量全压曲线与理论叠加曲线进行比较,发现2种风机串联时不完全符合叠加原理;异类风机串联时2种风机前后位置不同,排气性能亦不同;横流风机与离心风机串联,离心风机作为前级风机时,其串联性能优于横流风机作为前级风机时的串联性能。     

Simulation of the phenology of soybeans

Simulation models of three phases of soybean phenology—sowing to primary leaf, primary leaf to flower initiation and flower initiation to flowering—were generated for the soybean cultivar Lee and others. The basic experimental data were obtained from a series of glasshouse experiments under six temperature regimes in natural light.The data for leaf development rates showed a change in the response to temperature at the first trifoliate leaf stage; this was incorporated into the model.The flower initiation model included parameters for the production and decay of a theoretical flower promoter and for the rate of change of daylength. Time to flower initiation showed a complex relationship to photoperiod which could not be described or approximated to by any simple function. The effects of temperature were marked and showed a strong interaction with photoperiod.The flower development model accounted for a strong temperature response which was conditioned by a photoperiod effect.The three models were combined to form a soybean phenology model which was validated against phenological data obtained from date of sowing experiments conducted under field conditions.     

1GZ-20型耕整机旱耕性能的提高

提出了水田耕整机在旱耕时出现的一系列问题,着重分析了其中的耕深、耕宽及其稳定性问题,并在此基础上提出了解决办法,还作了试验验证。     

施水播种条件下灌溉水入渗模型研究

运用土壤动力学原理建立了灌溉水入渗的数学模型，并进行了实际灌水的试验验证，试验结果表明所建模型的模拟结果与试验结果吻合较好。应用模型模拟分析发现：适量增加沟宽或回土量可以减小入渗时间，缩短播种机排水口至排种口距离。     

面向机器人抓取的小型直线串联弹性驱动器设计与控制

面向机器人力控自适应抓取,设计一种微型直线串联弹性驱动器及其机电一体化系统。开展非线性校正试验,采用BCM法对微型直线串联弹性驱动器感知系统进行校正,以提高力控系统测量精度。基于双位移传感器构建驱动力、位移同步感知方法,并开展模型辨识试验建立目标变形轨迹及驱动力观测模型,根据目标变形轨迹模型建立驱动力PID控制策略。开展阶跃力控与自适应抓取试验,优化力控制器参数并研究串联弹性力控自适应抓取特性。试验结果表明,建立的微型串联弹性驱动器具备感知驱动一体化特性,可在无力传感器的情况下实现驱动力准确感知与控制。微型串联弹性驱动器力控超调量极低,当目标驱动力幅值为15N时,超调量为0.6%。在机器人力控自适应抓取试验中,指尖抓持姿态可通过驱动力控制实现调控,使指尖抓持力方向指向物体质心,从而达到增强抓持稳定性的目的。     

大跨高比平面钢闸门抗震性能模型试验研究

设计中的沙井河口中孔闸门具有跨高比大、自重大、悬挂运行、闸墩高耸等特点,为保证闸门的安全运行,在振动台上进行了该闸门完全水弹性相似模型抗震试验。试验结果表明,无水和反向挡水时,闸门与闸墩的前六阶自振频率分别为1.28-20.15 Hz和1.65-5.22 Hz,均与计算值接近。选择迁安波、ELCENTRO-NS波、TAR_TARZANA波作为试验用地震波,试验中迁安地震波作用下闸门和闸墩的动应力较大,其次为TAR_TARZANA波,而ELCENTRO-NS波作用时结构的动应力最小。钢闸门最大动应力17.01 MPa,最大加速度0.22g,发生在TAR_TARZANA波沿顺河向发生时。混凝土闸墩最大动应力1.57 MPa,最大加速度0.69g,发生在迁安波沿顺河向发生时。顺河向地震为不利工况,闸门悬挂对闸墩结构抗震不利。选择合适的止水材料有利于闸门减震。     

两种双腔串联压电泵结构设计与性能比较

为研究结构形式对双腔串联压电泵输出性能的影响,根据其工作原理,设计了有导流槽和无导流槽两种结构形式的双腔串联有阀压电泵,并加工制造了试验样机,分别以水和空气为介质进行输出性能比较试验．试验结果表明,在110V正弦交流电驱动下,有导流槽结构的双腔串联压电泵流量输出性能更好,输出的最大液体和气体流量分别为1100和650mL／min,但容易在导流槽内残留气泡;两者压力输出性能整体上比较接近,最大输出压力可达100kPa;无导流槽的双腔串联压电泵整体自吸性能更好,最大自吸高度为45cm水柱．     

HydroLOGIC: An irrigation management system for Australian cotton

The worldwide need to improve water use efficiency within irrigated agriculture has been recognised in response to environmental concerns and conflicts in resource use. Within the Australian cotton industry, the imperative to reduce water use and optimise irrigation management through the understanding of risk, using information generated by computerised decision aids was identified and subsequently developed into the HydroLOGIC irrigation management software. This paper summarises the attributes of the HydroLOGIC irrigation management software, with particular emphasis on functionality and its application to irrigation decisions within the Australian cotton industry. The software development process is documented to provide direction for future software application initiatives, with particular emphasis on a process of user feedback, evaluation and support requirements providing direction to software development. On-farm experiments throughout the development period allowed the validation of internal software logic, irrigator decision processes, and the OZCOT cotton growth model. The software demonstrated the ability to improve yield and water use efficiency by optimising strategic and tactical irrigation decisions in the Australian furrow irrigation cotton production system. In 7 of the 11 on-farm experiments conducted, the use of HydroLOGIC helped improve overall field water use efficiency by optimising the timing of irrigation events or by indicating further irrigations would not provide yield or maturity benefits. The paper also presents useful insights into the development of software targeted for irrigation utilising in-field measurements of soil water, crop growth and a crop growth simulation model.     

现代审计风险模型的分析探讨

现代审计风险模型是应用现代风险导向审计理论指导审计实务的工具。本文在分析该模型的逻辑结构和相关概念的基础上，讨论了如何使用现代审计风险模型进行审计。     

多工况高效无过载低比转数离心泵设计优化

为满足低比转数离心泵对多工况点效率和无过载特性要求,针对模型泵TS65-40-160,基于无过载理论进行设计优化,通过CFD分析内部流动分布规律,并采用快速成型模型试验进行对比分析。经过多方案改进得到较优方案2,该方案扬程在关死点、设计点以及最大流量点均高于设计要求;最高机组效率提高了14%,功率特性曲线出现了无过载趋势,在最大要求流量点48 m3/h处输入功率却未增大,且泵效率达到国家标准要求。经多方案CFD模拟和试验数据对比,证明模拟精度可满足模型优选要求。     

气流脉动流化干燥试验研究

对几种物料进行了气流脉动流化干燥试验，通过试验结果分析了不同风温，风速，不同的气体分布板开孔率，不同的脉动频率对脉动流化干燥过程的影响，找出了试验所用物料的脉动脉动流化干燥的较佳频率，进行了普通流化床干燥，脉动流化床干燥的对比试验。     

降雨时间序列分解预测模型及应用

为了对随机型时间序列进行预测，在分析其性质的基础上，提出了将其分解为趋势项、周期项和平稳随机项，建立时间序列分解预测模型，分别对趋势项和周期项进行检验和提取，利用自回归模型人工合成新的序列对平稳随机项进行模拟和预测。将该模型应用于降雨量预测，取得良好效果，表明了该模型的有效性和适用性。     

The deposition of electrostatically charged sprays on parts of targets shaded from the spray

This paper reports experiments aimed at measuring deposits from electrostatically charged hydraulic nozzles on targets consisting of vertical columns of horizontal discs. Particular attention is given to deposits on the parts of the targets shaded from the spray. The variables investigated were disc spacing, target spacing, wind speed and charge.The results showed that charging increased target deposits under all conditions and particularly when there was no wind and the targets were well spaced apart. Disc spacing was only found to have a small effect on target deposits. Most of the effects found in the experiments are explained with the aid of a simple mathematical model.The implications of the work are discussed in relation to the results of field experiments with the charging system.