Integrating spectral indices with environmental parameters for estimating heavy metal concentrations in rice using a dynamic fuzzy neural-network model

A generalized dynamic fuzzy neural network (GDFNN) was created to estimate heavy metal concentrations in rice by integrating spectral indices and environmental parameters. Hyperspectral data, environmental parameters, and heavy metal content were collected from field experiments with different levels of heavy metal pollution (Cu and Cd). Input variables used in the GDFNN model were derived from 10 variables acquired by gray relational analysis. The assessment models for Cd and Cu concentration employed five and six input variables, respectively. The results showed that the GDFNN for estimating Cu and Cd concentrations in rice performed well at prediction with a compact network structure using the training, validation, and testing sets (for Cu, fuzzy rules=9, R² greater than 0.75, and RMSE less than 2.5; for Cd, fuzzy rules=9, R² greater than 0.75, and RMSE less than 1.0). The final GDFNN model was then compared with a back-propagation (BP) neural network model, adaptive-network-based fuzzy interference systems (ANFIS), and a regression model. The accuracies of GDFNN model prediction were usually slightly better than those of the other three models. This demonstrates that the GDFNN model is more suitable for predicting heavy metal concentrations in rice.     

ATM与千兆以太网——谈校园网建设与网络选型

校园网是学校信息化建设的重点,在校园网的建设中,选择的主干网络技术将直接关系到校园网的先进程度及对各种网络多媒体应用的支持程序。本文根据网络发展趋势,对ATM技术与近年来发展起来的千兆以太网交换技术进行了分析对比,指出了网络升级时需注意的问题。     

材料在城市公共设施设计中的应用

公共设施作为城市空间的要素之一,已是城市形象构筑中不可缺少的一部分。在提倡可持续发展的现代社会,产品在满足审美性、使用性的同时,材料的应用至关重要。本文分析现代社会,城市公共设施设计中材料的使用情况,并从绿色设计角度展望未来的材料前景。     

航炮故障监测传感器

介绍了航炮故障监测传感器的基本电路与结构 ,详细论述了航炮故障监测传感器 ,在航炮发生射击故障的情况下的排故原理与过程     

基于Windows2000WDM模型的AD板采样驱动程序的设计

介绍了Windows2000操作系统下的WDM驱动程序基本设计方法,并以一款AD板为例给出了驱动入口点、创建和删除设备、硬件资源分配和访问、Win32应用程序接口等的具体实现,最后介绍了设备驱动程序的安装步骤。     

基于"新颖度"的关联挖掘算法

关联挖掘的目的是从大量数据中发现对用户有用、新颖、重要的关联规则.传统的关联挖掘算法会产生大量对用户而言显而易见的平凡规则,使那些真正对用户有用的新颖规则被淹没,而一些针对新颖性的改进算法往往又存在先验知识表达复杂且工作量极大的问题.在本文中,我们运用简单的分类树,引入"新颖度"的概念,对Apriori算法进行改进,得到了基于"新颖度"的关联挖掘算法,此算法既充分考虑了挖掘过程中得新颖性问题,又克服了先验知识表达过于复杂的困难.     

水热法合成13X型沸石的相变转化机理

以偏铝酸钠、九水硅酸钠、氢氧化钠和蒸馏水为原料,采用水热法合成13X沸石,为探究其相变转化机理,通过X射线衍射(XRD)、扫描电子显微镜(SEM)、红外(FT-IR)光谱分析和拉曼(Raman)光谱分析等测试手段,对不同反应时间合成的样品进行了物相、显微形貌及骨架结构演变的分析.结果表明,13X型沸石的硅铝酸阴离子骨架在反应初期就已形成,其晶化过程是不同类型13X沸石的物相演化过程,对应于沸石骨架中硅铝原子比的不断修正.随着沸石骨架中硅铝原子比先减小后增大,13X沸石的相变过程经历了一个先正相变后逆相变的过程,总相变式为:13X型沸石(Ⅰ)(Na1.84[(Al2Si4)O11.92]·7H2O)→13X型沸石(Ⅱ)(Na2[Al2Si3.3O10.6]·7H2O)和13X型沸石(Ⅲ)(Na2.06Al2Si3.8O11.63·8H2O)→13X型沸石(Ⅳ)(Na2Al2Si2.5O9·6.2H2O)→13X型沸石(Ⅱ)和13X型沸石(Ⅲ)→13X型沸石(Ⅰ)和13X型沸石(Ⅲ).     

Investigation on mechanism of polymer filling in high-aspect-ratio trenches for through-silicon-via (TSV) application

Vacuum-assisted spin-coating is an effective polymer filling technology for sidewall insulating of through-silicon-via (TSV). This paper investigated the flow mechanism of the vacuum-assisted polymer filling process based on experiments and numerical simulation, and studied the effect of vacuum pressure, viscosity of polymer and aspect-ratio of trench on the filling performance. A 2D axisymmetric model, consisting of polymer partially filled into the trench and void at the bottom of trench, was developed for the computational fluid dynamics (CFD) simulation. The simulation results indicate that the vacuum-assisted polymer filling process goes through four stages, including bubble formation, bubble burst, air elimination and polymer re-filling. Moreover, the simulation results suggest that the pressure significantly affects the bubble formation and the polymer re-filling procedure, and the polymer viscosity and the trench aspect-ratio influence the duration of air elimination.     

Segmentation of telecom customers based on customer value by decision tree model

The more the telecom services marketing paradigm evolves, the more important it becomes to retain high value customers. Traditional customer segmentation methods based on experience or ARPU (Average Revenue per User) consider neither customers’ future revenue nor the cost of servicing customers of different types. Therefore, it is very difficult to effectively identify high-value customers. In this paper, we propose a novel customer segmentation method based on customer lifecycle, which includes five decision models, i.e. current value, historic value, prediction of long-term value, credit and loyalty. Due to the difficulty of quantitative computation of long-term value, credit and loyalty, a decision tree method is used to extract important parameters related to long-term value, credit and loyalty. Then a judgments matrix formulated on the basis of characteristics of data and the experience of business experts is presented. Finally a simple and practical customer value evaluation system is built. This model is applied to telecom operators in a province in China and good accuracy is achieved.     

Ti（1-x）CoxO2的溶胶-凝胶法制备与结构

采用溶胶-凝胶方法制备了Ti（1-x）CoxO2样品。研究了不同的热处理温度和掺杂浓度对样品晶型和颗粒尺寸的影响。样品400℃热处理呈锐钛矿相，600℃转变为全红石相并且晶粒尺寸明显增大。掺杂对晶型没有影响，但是随掺杂量的增大晶格常数减小。