预应力钢-混组合梁界面滑移性态试验研究

预应力组合梁作为一种新型的结构,其承载力影响因素众多.受外荷载时,预应力钢-混组合梁的混凝土翼板和钢梁不可能实现完全共同作用,交界面处会发生相对滑移,对其受力性能产生不利影响,因此有必要对预应力组合梁的界面滑移进行深入研究.根据预应力钢-混组合梁界面滑移的试验结果,分析了钢-混组合梁界面滑移的分布和发展规律,界面滑移随荷载的增大而增大,在组合梁的弹性工作阶段变化较慢,弹塑性阶段增加较快;相对滑移会导致钢和混凝土交界面上产生应变差.     

基于Chirp Scaling的双基SAR成像PFA算法研究

该文研究了基于Chirp Scaling原理实现双基聚束SAR成像的极坐标格式算法(Polar Format Algorithm, PFA)。PFA通过两个一维插值来实现数据的极坐标格式转换,插值计算量较大。该文基于发射信号的线性调频特性,在距离向对极坐标格式数据进行变标处理,仅包含信号复乘和FFT,从而避免了插值运算。文中对于接收Chirp信号和Dechirp信号分别进行了讨论,依照不同流程实现了极坐标格式算法。同插值方法相比,二者聚焦结果相当,但是CS(Chirp Scaling)的方法速度有显著提高。点目标仿真实验验证了此方法的有效性。     

深基坑的支护施工与监测

文章介绍了深基坑工程的特点,从实际工程入手讲解了深基坑在施工中遇到的常见问题及处理意见。     

基于无线传感器网络的温室智能监测系统研究

温室大棚内使农作物反季节生长的核心要素即为温度及湿度,因而对温度及湿度进行监测是至关重要的.针对当前通过人工采集模式及通过有线控制网络监测模式检测温湿度中所存在的问题,结合温室环境变化特性及采集要求,提出了利用无线传感器网络改进监测系统的思想,设计实现了一种基于ZigBee的温室智能监测系统,该系统由PC管理机节点、温室基站节点及传感器节点三部分组成.实验结果表明,该系统具有检测精度高、误差小及可靠性高的优点.     

Static Checking of Array Index Out-of-Bounds Defects in C Programs Based on Taint Analysis

During the rapid development of mobile computing, IoT, cloud computing, artificial intelligence, etc., many new programming languages and compilers are emerging. Nevertheless, C/C++ is still one of the most popular languages, and the array is one of the most important data structures of C language. It is necessary to check whether the index is within the boundary of the array when it is used to access the element of an array in a program. Otherwise, array index out-of-bounds will happen unexpectedly. When array index out-of-bounds defects are in programs, some serious errors may occur during execution, such as system crash. It is even worse that array index out-of-bounds defects open the doors for attackers to take control of the server and execute arbitrary malicious codes by carefully constructing input and intercepting the control flow of the programs. Existing static methods for array boundary checking cannot achieve high accuracy and deal with complex constraints and expressions, leading to massive false positives. In addition, it will increase the burden of developers. In this study, a static checking method is proposed based on taint analysis. First, a flow-sensitive, context-sensitive, and on-demand pointer analysis is proposed to analyze the range of array length. Then, an on-demand taint analysis is performed for all array indices and array length expressions. Finally, the rules are defined for checking array index out-of-bounds defects and the checking is realized based on backward data flow analysis. During the analysis, in light of complex constraints and expressions, it is proposed to check the satisfiability of the conditions by invoking the constraint solver. If none statement for avoiding array index out-of-bounds is found in the program, an array index out-of-bound warning will be reported. An automatic static analysis tool, Carraybound, has been implemented, and the experimental results show that Carraybound can work effectively and efficiently.     

一种机器人逆运动学求解的神经网络方法

研究了机械手控制的逆运动学问题,提出了一种克服Hopfield网络的局部极值问题的网络参数扰动算法,通过数字模拟分析了该算法的性能,并将该算法成功地应用于机械手控制的逆运动学问题。计算机仿真表明,这种神经网络控制方法不仅具有较快的速度,而且大大提高了对机械手的控制精度。     

面向上下文图形可视化挖掘企业网络行为

在企业分布式网络系统中,精确、动态地发现用户的网络行为日益具有挑战性。目前网络管理系统主要依赖于对用户身份的推理来进行网络行为管理,此类方法由于所收集到的数据缩放比粗糙,从而在大规模的网络环境下不能精确地对网络行为进行挖掘、发现和管理。对主机、用户、应用程序等网络上下文内容进行可视化挖掘,为动态地进行网络管理提供了重要帮助。     

基于 RFID 的电力设备全自动电子台账管理方案

提出了基于 RFID 电力设备自动电子台账管理方案。首先分析了电力设备目前运行和管理中存在的问题,说明了全自动化台账管理的必要性;然后针对 RFID 的原理,说明了 RFID 有源标签和检测设备物理模块的整合方案和整体构架;最后针对设备台账自动化在设备全寿命周期管理中的应用进行了分析,说明了基于 RFID 的电力设备全自动台账管理方案的有效性。     

粘粉土地层工程废弃泥浆絮凝脱水试验研究

针对岩土工程施工过程中产生的大量废弃泥浆的快速减量问题,选取在粘粉土地层施工时产生的废弃泥浆,分别添加阴离子型聚丙烯酰胺（APAM）、非离子型聚丙烯酰胺（NPAM）以及聚合氯化铝（PAC）开展室内絮凝沉降试验研究,根据沉降曲线、上清液浊度、底泥密度及含水率等指标,结合絮凝剂絮凝机理,得出最佳絮凝剂及其最优添加量,据此进行现场絮凝试验。结果表明,现场采用添加量为0.5%的阴离子型聚丙烯酰胺（APAM）进行泥浆絮凝处理效果良好,可快速达到理想的絮凝、沉降、上浮、污泥脱水处理效果。     

Geometric Calibration Method of Robot Based on Measurement System Including Position and Orientation Parameters

Industrial robot which can acquire high accuracy has been widely used in automatic assembly.Usually,the geometric parameter of industrial robot should be inspected during manufacturing and application. High precision measurement equipment was utilized to acquire the position and orientation of robot’s end-effector,when calibrating the geometric parameter of robot. A kind of measurement system based on a draw-wire encoder was presented,since the current measurement equipment has some disadvantage...