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type of entity called virtual data agent was introduced. The data placement problem was converted into two mapping processes namely mapping from the data set to the virtual data agent and mapping from... Mapping of data set to virtual data agent 同样采用2.1节中的实例.对于虚拟数据代理a=(1.45,0.168,0.052),其被c2请求次数最多,因此,将被存储在数据中心c2上.为记录方便,设VDA的编号与其所属的数据中心编号一致.同理,得到3个虚拟数据代理与数据中心c1,c2和c3,根据总请求次数所得映射结果如表3所示. 表3 映射结......
低碳钢热变形过程中铁素体的织构形成规律 孙祖庆1,常守海2,杨平2 (1.北京科技大学新金属材料国家重点实验室;2.北京科技大学) 摘要:利用背散射电子衍射取向成像技术定量分析了热模拟单向压缩条件下Q235碳素钢热变形时铁素体的织构形成规律.结果表明,在710℃纯铁素体热压缩过程中,形成和方向的线织构.方向织构增强的速度较快,到应变为1.0时达最大值,然后随应变的加大而减弱;方向织构在形变量较小时增强的速度较慢,在大应变时增强的速度很快.大应变时虽导致一定程度的动态再结晶,使铁素体晶粒细化,但组织不均匀,织构过强,造成强烈的各向异性.在奥氏体与铁素体两相区变形时,先共析铁素体因形变同样产......
全站仪自由设站在测绘中的应用 刘小伟1,骆旭佳1,高飞1,胡小华2 (1.合肥工业大学土木与水利工程学院,合肥市,230009;2.合肥市国土资源局地理信息中心,合肥市,230001) 摘要:利用全站仪在野外进行测量时,往往会出现两个所给控制点不通视的情况.此时利用常规的交会方法将无法进行下一步工作.在对全站仪自由设站的原理和方法进行分析后,全站仪自由设站方法可以快速的解决上述问题.且自由设站方法精度高,设站灵活,不受后方交会危险圆的限制. 关键词:全站仪; 自由设站; 后方交会; [全文内容正在添加中] ......
of the object, a systematic method based on statistical pattern recognition is developed in order to estimate the product quality on-line. The mapping relationship between a feature space and a product... the method mentioned above, a satisfying result has been achieved. Furthermore, the further question about choosing suitable mapping methods is briefly discussed.关键词:......
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, or with a native oxide layer.The as-deposited Y2 O3 layers are smooth, conformal, dense and transparent and are of a thickness of 27 and 30 nm, respectively.关键词:......
, or with a native oxide layer.The as-deposited Y2 O3 layers are smooth, conformal, dense and transparent and are of a thickness of 27 and 30 nm, respectively.关键词:......
电子电气产品中19种元素的无损测定,分布研究及风险评估高欢,卫碧文,倪旎,望秀丽上海出入境检验检疫局摘 要:采用X射线荧光光谱法快速无损扫描测定电子电气产品中19种元素,考察了特征X射线以及计数时间的选择,并通过自制标准块绘制标准曲线.同时利用MAPPING功能进行微区原位扫描,掌握19种元素的分布情况及分布特征.并利用换算因子计算REACH高关注物质的含量,对19种元素进行风险性评价.关键词:XRF;电子电气产品;快速无损;分布研究;风险评估;......
基于地面检校场的DMC几何精度评估许妙忠1,陶翊婷1,罗红联2,李占良21. 武汉大学2. 中勘冶金勘察设计研究院有限责任公司摘 要:DMC(Digital Mapping Camera)是目前广泛使用的框幅式航空传感器.该文利用武汉大学建设的永久性嵩山航空几何检校场,对DMC在不同航线结构,不同控制数量及分布以及不同平差模型下的几何精度进行了对比分析和评估.实验结果证明,构架航线和控制点分布对DMC几何精度影响有限,但带附加参数的平差模型可以显著提高其几何学精度.关键词:DMC;几何精度;自检校;平差模型;地面检校场;......
method integrating support vector machine (SVM), particle swarm optimization (PSO) and chaotic mapping (CPSO-SVM) was proposed to predict the deformation of tunnel surrounding rock mass. Since chaotic mapping was featured by certainty, ergodicity and stochastic property, it was employed to improve the convergence rate and resulting precision of PSO. The chaotic PSO was adopted in the optimization......