基于kmeans-SVM的二叉树粗分类方法

针对大型数据库中进行匹配识别时存在识别速度慢、时间长、影响实时应用效果的问题,提出了一种树形层次结构的粗分类方法。通过k-means得到两类粗分类的样本,用这两类粗分类数据训练SVM分类器,找到分类超平面,再不断调整分类超平面,最后构建二叉树型结构达到粗分类的目的。三个方法相结合很好地缩小目标的搜索范围,提高了识别时候的效率。     

磺化工艺的危险性及可操作性分析

磺化工艺作为国家安全监管总局所列的首批重点监管的危险化工工艺,已经受到政府部门、企业以及设计单位的高度重视。通过对磺化工艺的介绍,阐述如何通过辨识危险因素,确定重大危险源,从而采取相关的应急停车系统,并通过引用HAZOP分析技术来进行危险工艺的安全设计,进而采取合理的事故防范措施。     

采用微型桩加固塔吊基础的工程实践

天然地基承载力不能满足要求时,必须采用桩基加固塔吊基础。某高层建筑施工场地狭小,无法进行正常桩基础施工,采用微型桩加固塔吊地基处理仅用1d时间,经济效益良好,塔吊运行安全。     

大气吸收系数的研究与应用

定义了大气吸收系数的概念．通过试验及理论分析．得出我国各地区大气吸收系数推荐值，并时体育场场地照明照皮计算进行修正。     

基于同种沥青不同级配的大空隙沥青混合料渗水性能试验与评价

通过浸水马歇尔试验、冻融劈裂试验、车辙试验和渗水试验来评价基于同种沥青不同级配的大空隙沥青混合料的水稳定性、高温稳定性和渗水性能等,分析了大空隙沥青混合料路用性能渗水性能与级配、空隙率的之间关系,从而为大空隙沥青混合料提供设计依据.     

Assessment of Effective Monitoring Sites in a Reservoir Watershed by Support Vector Machine Coupled with Multi-Objective Genetic Algorithm for Sediment Flux Prediction during Typhoons

Water Resources Management - Effectively assessing crucial monitoring sites with suspended sediment concentration (SSC) is a vital challenge for achieving accurate prediction of sediment flux on...     

Modelling corn production in China using AVHRR‐based vegetation health indices

Weather‐related crop losses have always been a concern for farmers, governments, traders and policy makers for the purpose of balanced food supplies, demands, trade, and distribution of aid to nations in need. Therefore, early crop loss assessment in response to weather fluctuations is an important issue. This paper discusses the utility of Advanced Very High Resolution Radiometer (AVHRR)‐based vegetation health indices as a proxy for modelling corn yield and for early warning of drought‐related losses of agricultural production in China. The indices were tested in Jilin province on corn yield during 1982–2001 using correlation and regression analysis. A strong correlation between corn yield and the vegetation health indices were found during the critical period of corn growth, which starts 2–3 weeks before and 2–3 weeks after corn tassel. Following the results of correlation analysis, several regression equations were constructed where vegetation health indices were used as independent variables. The estimates of corn yield can be carried out well in advance of harvest and the errors of the estimates are 7–10%. The errors become smaller when the estimations are related to losses in corn yield due to drought.     

Effects of different loads on structure stress of “L”-type large-diameter buried pipe network based on fluid-structure-heat coupling

Large-diameter buried pipeline is widely used because of its energy-saving advantage and high efficiency. In this paper, “L”-type heat pipe network was taken as the research object, which was studied using the flow–heat–solid coupling method. The ANSYS Workbench platform was used to simulate heat transfer and the flow of the medium in the pipe network. The pressure and temperature of the flow field and the temperature, equivalent stress of the solid structure under different conditions were calculated, and the force characteristics of pipe network and elbow under coupled and non-coupled loads were compared. Results show the maximum equivalent stress was located at inner wall surface of the short-arm anchor end. The equivalent stress of the inner wall was larger than that of the outer wall at the same position. The stress of the straight pipe of the pipe network was mainly affected by the temperature of the fluid, whereas the stress of elbow was mainly affected by the pressure. The stress distribution of the pipe network was influenced by the temperature and pressure loads coupled and the coupling effect was stronger with the higher pressure and temperature of the medium, but the coupling effect had its limit.     

冷扩孔并置入栓钉技术止裂效果研究

采用有限单元法对冷扩孔并置入栓钉处理措施进行数值模拟,并对循环荷载下止裂孔孔边应力、应变状态的分析表明,冷扩孔并置入栓钉降低了应力集中部位的应变幅,从而延长疲劳裂纹在止裂孔边的再生寿命,栓钉直径均会影响钻孔止裂相关技术的止裂效果.     

含水固形物干燥脱水蒸汽再利用专利技术工艺及设备

在无机盐产品生产过程中,中间产品和副产品通常需要进行干燥,文章对含水固形物干燥脱水蒸汽再利用工艺及设备进行了论述。并就干燥脱水蒸汽再利用专利工艺及设备对节省能源消耗进行了分析。