混沌遗传最小二乘支持向量机法预测日用水量

利用混沌运动的初值敏感性、内在随机性和遍历性的特点,提出基于混沌遗传算法和最小二乘支持向量机的城市日用水量预测法。通过混沌映射搜索自适应遗传算法的较优初始种群,采用自适应遗传算法优化最小二乘支持向量机的超参数,利用交叉验证法确定遗传算法个体的适应值,建立基于最小二乘支持向量机的日用水量预测模型。实例分析结果表明,与基于遗传最小二乘支持向量机的日用水量预测法相比,提出的预测方法具有更高的预测精度。     

基于BA-LSSVM模型的月径流预测方法

针对最小二乘支持向量机模型传统参数选择方法费时且效果差的问题,利用蝙蝠算法的模型简单、快速收敛和全局搜索能力强的特点,优化模型的正则化参数和核函数参数,对水文时间序列建立最小二乘支持向量机预测模型。基于西江流域内的柳州水文站2000-2014年月径流资料对模型进行训练和预测,并与使用粒子群算法优化参数确定的最小二乘支持向量机模型,网格搜索及交叉验证优选参数确定的最小二乘支持向量机模型及BP神经网络模型进行比较。计算结果表明,基于蝙蝠算法优化最小二乘支持向量机模型具有很好的适用性和较高的预测精度,为利用最小二乘支持向量机模型解决非线性的水文时间序列问题提供了新的方向。     

基于联合时序的混沌时用水量短期预测调度

针对给水优化调度的时用水量高精度短期预测难题,提出一种基于横向分时段和纵向残差修正的联合时序短期混沌预测方法.经模式识别获得关联度高的横向时序为研究样本,重构横向分时段相空间并分析典型时段流量数据的混沌特性,建立混沌预测模型,以在线最小二乘支持向量机作为混沌预测工具得出各时段用水流量;为了能动态跟踪用水突变,实时采集纵向数据序列做残差计算,进而用灰色模型进行残差预测修正以提高预测精度.依据杭州市萧山某大用户时用水量实例,对一段时间的正常用水和突变用水做连续24 h短期混沌预测,在不同方法下的时用水量预测精度作深入对比研究.仿真结果表明：该预测方法对这一类混沌时序短期预测具有良好的计算精度,能很好反映各典型用水日的特点和实时用水变化情况,预测效果明显优于其他预测方法,更易满足供水优化调度的需求.     

基于MSCPSO混合核SVM参数优化的生菜品质检测

核函数形式的选择与核函数参数值的大小是影响支持向量机的2个关键因素,传统的支持向量机分类精度低、时效性差,为了获得高精度、高时效性的支持向量机,从影响支持向量机的核函数与核函数参数值2个关键因素着手,提出了基于变尺度混沌粒子群优化（MSCPSO）混合核SVM参数的分类器。将此分类模型用于预测生菜叶片的生育期,以及预测3个生育期的生菜叶片氮素水平,预测精度分别达到91.51%、85.38%、82.59%和81.26%。与传统的粒子群优化混合核SVM的分类器和变尺度混沌粒子群优化RBF_SVM分类器相比,提出的分类器模型分类精度高、时效性好。     

最小二乘支持向量机模型在径流预报中的应用

为解决径流中长期预报模型精度较低的问题,提出了一种基于混沌时间序列的最小二乘支持向量机预测方法,该方法依据相空间重构技术以及最小二乘支持向量机模型(以下简称LS_SVM)。利用该模型对黄河三门峡1919-1989年的71年实测年径流量进行预测。经过反复计算分析表明LS_SVM模型在径流中的应用具有较快的计算速度、较好的泛化能力以及较高的预测精度。     

近红外光谱结合最小二乘支持向量机的脐橙叶片含水率无损检测

为了快速检测赣南脐橙果树叶片含水率,提出近红外光谱结合最小二乘支持向量机的快速检测方法。采用积分球漫反射方式采集叶片的近红外光谱,通过间隔偏最小二乘法从2 074个光谱变量中优选出345个变量作为建模的输入向量,分别建立最小二乘支持向量机和偏最小二乘校正模型。经比较,以径向基函数为核函数的最小二乘支持向量机模型预测结果最优,预测相关系数为0.942,预测均方根误差为2.7%,模型建立及预测时间为0.176s。实验结果表明近红外光谱结合最小二乘支持向量机的脐橙叶片含水率无损检测方法是可行的。     

SVM大坝变形监测模型研究

大坝的变形监测数据是一个复杂的非线性的时间序列,采用传统的建模方法存在拟合和预报精度低等问题。传统算法中,基本遗传算法不能确保全局最优收敛,而普通多变异位自适应遗传算法在进化初期对群体不利,容易导致进化走向局部最优。针对这一问题,提出一种基于改进的多变异位自适应遗传优化支持向量机(SVM)的建模方法。多变异自适应遗传算法采用二进制多点交叉,可根据个体适应值大小,自动选取合适的交叉概率和遗传概率,针对遗传算法易陷入局部最优点,对上述遗传算法进行改进,并利用该算法对支持向量机的模型参数进行寻优。将上述建模方法用于大坝变形监控模型的建立,结果表明该组合算法能有效提高模型的拟合和预报精度。     

基于GA优化AR-LSSVR组合模型在区域降雨量预测中的应用研究

为了提高地区降雨量的预测精度,提出遗传算法优化的时间序列最小二乘支持向量机回归组合模型。首先利用时间序列分析法对858农场年降雨量数据进行拟合,其次对拟合后实际数据与拟合数据产生的绝对误差运用最小二乘支持向量机进行训练,较好地解决了小样本、高维数、非线性和局部极小问题,同时避开了传统的网格搜索法在大范围内寻找参数费时等缺点,采用遗传算法寻找最佳的惩罚参数c和核函数参数g,训练结果与实际测量值接近,预测精度较高,并对未来3a的降雨量进行了预测,为858农场未来水资源规划、合理制定灌溉制度、抗旱防涝提供了重要的科学依据。     

基于最小二乘支持向量机的人民胜利渠灌区灌溉用水量预测

基于最小二乘支持向量机（LSSVM）良好的泛化能力和特点,以人民胜利渠灌区需水量为研究对象,选用径向基函数（RBF）作为核函数,建立了最小二乘支持向量机预测模型,对灌区需水量进行了模拟计算,用检验样本与灰色预测和基于RBF的神经网络模型的预测结果进行了比较,LSSVM预测的最大误差8.78%,平均误差4.90%。结果表明最小二乘支持向量机模型有较高的预测精度和较强的泛化能力,可为灌区水资源规划提供科学依据。     

哺乳母猪舍环境舒适度评价预测模型优化

针对母猪舍多环境因子相互耦合,难以合理、准确地预测判断猪舍环境舒适度的问题,根据畜禽舍养殖环境标准,构建了评价指标体系,提出了基于变尺度混沌布谷鸟算法优化混合核最小二乘支持向量回归机的哺乳母猪舍环境舒适度评价预测模型(MSCCS-LSSVR),并采用粒子群算法优化模型(PSO-LSSVR)、遗传算法优化模型(GA-LSSVR)、传统的LSSVR模型与本文模型进行了对比。利用本文模型对江苏省镇江市希玛牧业生猪养殖场哺乳母猪舍养殖环境舒适度进行了评价预测。结果表明,混合核MSCCS-LSSVR、PSO-LSSVR、GA-LSSVR和传统LSSVR 4种预测模型的平均绝对误差分别为0.061 1、0.097 2、0.130 6和0.168 1;混合核MSCCS-LSSVR模型比其他3种模型具有更高的预测精度和更可靠的性能,提高了猪舍环境评价预测水平,在评价预测中具有可行性和有效性。实际应用表明,本文模型能准确地反映猪舍空气质量状况,可以为猪舍环境精准调控提供决策支持,具有一定的应用价值。     

Overland water and salt flows in a set of rice paddies

Cultivation of paddy rice in semiarid areas of the world faces problems related to water scarcity. This paper aims at characterizing water use in a set of paddies located in the central Ebro basin of Spain using experimentation and computer simulation. A commercial field with six interconnected paddies, with a total area of 5.31 ha, was instrumented to measure discharge and water quality at the inflow and at the runoff outlet. The soil was classified as a Typic Calcixerept, and was characterized by a mild salinity (2.5 dS m⁻¹) and an infiltration rate of 5.8 mm day⁻¹. The evolution of flow depth at all paddies was recorded. Data from the 2002 rice-growing season was elaborated using a mass balance approach to estimate the infiltration rate and the evolution of discharge between paddies. Seasonal crop evapotranspiration, estimated with the surface renewal method, was 731 mm (5.1 mm day⁻¹), very similar to that of other summer cereals grown in the area, like corn. The irrigation input was 1874 mm, deep percolation was 830 mm and surface runoff was 372 mm. Irrigation efficiency was estimated as 41%. The quality of surface runoff water was slightly degraded due to evapoconcentration and to the contact with the soil. During the period 2001–2003, the electrical conductivity of surface runoff water was 54% higher than that of irrigation water. However, the runoff water was suitable for irrigation. A mechanistic mass balance model of inter-paddy water flow permitted to conclude that improvements in irrigation efficiency cannot be easily obtained in the experimental conditions. Since deep percolation losses more than double surface runoff losses, a reduction in irrigation discharge would not have much room for efficiency improvement. Simulations also showed that rice irrigation performance was not negatively affected by the fluctuating inflow hydrograph. These hydrographs are typical of turnouts located at the tail end of tertiary irrigation ditches. In fact, these are the sites where rice has been historically cultivated in the study area, since local soils are often saline-sodic and can only grow paddy rice taking advantage of the low salinity of the irrigation water. The low infiltration rate characteristic of these saline-sodic soils (an experimental value of 3.2 mm day⁻¹ was obtained) combined with a reduced irrigation discharge resulted in a simulated irrigation efficiency of 60%. Paddy rice irrigation efficiency can attain reasonable values in the local saline-sodic soils, where the infiltration rate is clearly smaller than the average daily rice evapotranspiration.     

瓦房店市水果生产标准化发展研究

瓦房店市是我国重要的水果生产基地,在国内水果生产领域占有重要地位。随着水果市场化的不断深入,如何满足和适应国内外市场需求成为瓦房店市水果生产的关键问题。从瓦房店市水果生产实际出发,阐述了实施水果生产标准化的必要性,提出了发展水果生产标准化的具体措施。     

金谷子耐旱TG118引种试种及推广应用

对引进的谷子新品种金谷子耐旱TG118进行品种比较试验和多点试种。结果表明：该品种抗旱、耐瘠、适应性强,稳产、高产、抗病抗风抗倒伏强,品质优良,粮草兼用,种植简单,省工易管;一般产量在6000kg/hm2以上,比当地主栽品种增产20%以上。最高产量达9450kg/hm2,适于在辽西北地区推广应用。     

对《种子法》存在问题的探讨

《种子法》是我国种植业第一部法律。自实施以来,为依法加强种子管理提供了有力的法律支撑,促进我国种子产业发生翻天覆地的变化。但随着依法管理工作的深入和种子产业的快速发展,《种子法》及配套规章的一些问题逐步显现出来。对《种子法》及配套规章存在的问题进行深入分析,对需要进一步补充的章节以及需要调整的内容进行深入探讨,以求更加完善和明确。     

Review of the Egyptian experience in implementing land drainage projects

About 30 years have passed since the Government of Egypt embarked on implementing a series of large scale drainage projects. At present, about 3.8 million acres have been provided with drainage systems on the basis of systematic pre-drainage investigations and designs. The target is to provide drains in approximately 6.4 million acres in the Nile Valley and Delta.The implementation of the subsurface drainage system is carried out by the public sector and private contractors under direct supervision of governmental regional departments. The implementation process depends on many factors related to the drainage material, machinery, manpower, site requirements, farmers and organizations involved. Problems and constraints are sometimes challenging, however, the annual rate of implementation has gradually increased to 170,000 acre/year.This paper discusses the different aspects involved in the implementation process of drainage systems. The development in materials, machinery and construction technologies will be reviewed. Institutional and management factors are going to be also considered.     

和谐社会理论建设的几点哲学思考

在新世纪,面对机遇和挑战,党的十六大把“社会更加和谐”作为全面建设更高水平的小康社会的一个重要目标。中国人素有社会和谐的理想;西方人自古也向往社会和谐;借鉴东西方两种和谐社会思想的经验、教训,构建社会主义和谐社会理论。     

A European irrigation map for spatially distributed agricultural modelling

We present a pan-European irrigation map based on regional European statistics, a European land use map and a global irrigation map. The map provides spatial information on the distribution of irrigated areas per crop type which allows determining irrigated areas at the level of spatial modelling units. The map is a requirement for a European scale assessment of the impacts of irrigated agriculture on water resources based on spatially distributed modelling of crop growth and water balance. The irrigation map was compiled in a two step procedure. First, irrigated areas were distributed to potentially irrigated crops at a regional level (European statistical regions NUTS3), combining Farm Structure Survey (FSS) data on irrigated area, crop-specific irrigated area for crops whenever available, and total crop area. Second, crop-specific irrigated area was distributed within each statistical region based on the crop distribution given in our land use map. A global map of irrigated areas with a 5′ resolution was used to further constrain the distribution within each NUTS3 based on the density of irrigated areas. The constrained distribution of irrigated areas as taken from statistics to a high resolution dataset enables us to estimate irrigated areas for various spatial entities, including administrative, natural and artificial units, providing a reasonable input scenario for large-scale distributed modelling applications. The dataset bridges a gap between global datasets and detailed regional data on the distribution of irrigated areas and provides information for various assessments and modelling applications.     

粉质仪和拉伸仪在面粉生产中的应用

在介绍粉质仪和拉伸仪结构和原理的基础上,探讨了粉质曲线中吸水率、形成时间、稳定时间、弱化度和评价值等指标与面粉品质的关系,以及如何根据拉伸曲线中面团最大拉伸阻力、延伸度和拉伸曲线面积等指标来评价面团品质,并结合生产实际,概述了粉质仪和拉伸仪在面粉生产中的作用。     

农村信息化服务的现状及建设措施

分析当前我国农村信息化服务的现状,提出加强农村信息化服务的新举措。     

车辆ABS控制算法的研究及探讨

对现代汽车的ABS控制算法作了一些简单的介绍,同时指出了它们的一些缺陷,相应地提出了几种对ABS的其它控制方法并加以探讨,其中着重论述了ABS门限值控制算法中参考车速的确定方法和基于附着系数的控制算法。