本征导电聚合物的智能性

在化学掺杂或电化学掺杂过程中，性质发生可逆性变化的本征导电聚合物是一种潜在的智能材料，可望实现或部分实现传感、处理和执竽功能，适于制成电机执行器、智能窗、化学分离与释放体系、传感器和非线性光学器件等。     

Synthesis and degradation of intelligent hydrogels containing polyacetal segments

Intelligent hydrogels were first obtained by copolymerization of telechelic poly(1,3-dioxolane) (pDXL) with acrylic acid, acrylamide, N-isopropylacrylamide respectively. The synthesis and characterization of the networks were discussed. The swelling behavior of the hydrogel was dependent on the solubility parameter of the solvents and hydrogels. The networks containing polyacetal segments (pDXL) can degrade by acid in different solvents. DXL and few other cycle molecules measured by GC-MS analysis were formed after degradation. According to the degradation products, the polymerization mechanism can be testified.     

基于卡口上下文和深度置信网络的车辆轨迹预测模型研究

针对车辆轨迹预测中节点序列的时序特性和实际路网中的空间关联性,该文提出一种基于深度置信网络和SoftMax (DBN-SoftMax)轨迹预测方法.首先,考虑到轨迹在节点集合中的强稀疏性和一般特征学习方法对新特征的泛化能力不足,该文利用深度置信网络(DBN)较强的无监督特征学习能力,达到提取轨迹局部空间特性的目的;然后,针对轨迹的时序特性,该文采用逻辑回归的预测思路,用当前轨迹集在路网特征空间中的线性组合来预测轨迹;最后,结合自然语言处理领域中的词嵌入的思想,基于实际轨迹中节点存在的上下文关系,运用节点的向量集表征了节点间的交通时空关系.实验结果表明该模型不仅能够有效地提取轨迹特征,并且在拓扑结构复杂的路网中也能得到较好的预测结果.     

The alternating basis algorithm for assignment problems

The purpose of this paper is to present a new primal extreme point algorithm for solving assignment problems which both circumvents and exploits degeneracy. The algorithm is based on the observation that the degeneracy difficulties of the simplex method result from the unnecessary inspection of alternative basis representations of the extreme points. This paper characterizes a subsetQ of all bases that are capable of leading to an optimal solution to the problem if one exists. Using this characterization, an extreme point algorithm is developed which considers only those bases inQ. Computational results disclose that the new algorithm is substantially more efficient than previously developed primal and primal-dual extreme point (simplex) methods for assignment problems.     

Cost operator algorithms for the transportation problem

A primal transportation algorithm is devised via post-optimization on the costs of a modified problem. The procedure involves altering the costs corresponding to the basic cells of the initial (primal feasible) solution so that it is dual feasible as well. The altered costs are then successively restored to their true values with appropriate changes in the optimal solution by the application of cell or area cost operators discussed elsewhere. The cell cost operator algorithm converges to optimum within (2T – 1) steps for primal nondegenerate transportation problems and [(2T + 1) min (m, n)] – 1 steps for primal degenerate transportation problems, whereT is the sum of the (integer) warehouse availabilities (also the sum of the (integer) market requirements) andm andn denote the number of warehouses and markets respectively. For the area cost operator algorithm the corresponding bounds on the number of steps areT and (T + 1) min (m, n) respectively.This report was prepared as part of the activities of the Management Sciences Research Group, Carnegie—Mellon University, under Contract N00014-67-A-0314-0007 NR 047-048 with the U.S. Office of Naval Research.     

Detection and Classification of Small Traffic Signs Based on Cascade Network

Research on the traffic sign detection is significant for driverless technology,which provides useful navigation information.Existing object detection methods are only applicable to large-size objects or small-scale specific types of traffic signs,and the performance of detecting traffic signs in street views is not adequate.In this regard,we propose a method to detect and classify small traffic signs by constructing a cascaded network.Specifically,the RetinaNet network is adopted firstly to integrate multi-layer information to identify small traffic signs in traffic scene images.The focal loss function is used to balance the biased distribution of traffic sign categories.Then,a two-class network is cascaded after the RetinaNet,which helps identify valid traffic signs from the first-stage prediction results.Experiments show that our cascaded network structure could achieve the balance of different categories of predictions and an improvement in precision and recall.     

智能超表面辅助低轨卫星通信技术综述

卫星通信能够提供超视距、大容量的通信服务,但在城市区域、峡谷森林等视线受遮蔽严重的区域,会出现视距衰落严重、多径效应显著等问题,影响通信质量。近年来出现的智能超表面(RIS)可以通过动态控制反射单元的电磁性质,构建可控电磁环境,为改善低轨(LEO)卫星通信质量提供新的思路。本文基于RIS基本原理与优势,对RIS用于LEO卫星通信中信道建模、信道估计、波束成形等关键技术进行探讨,最后分析了目前RIS在实际应用中面临的主要挑战,以期为LEO卫星场景下的RIS研究提供参考。     

智能手机蓝牙抄表设计方案

目前,在我国的电力、燃气、热力、自来水行业,大部分仍然采用无线远程集抄和手持抄表机的人工抄表模式。随着智能手机的普及,手机的功能和质量已经远远强于一般的数据采集手持设备。使用手机抄表软件可以轻松实现日常数据采集抄录工作。并可以使用手机的网络实现数据的及时上传下载。本文提供一种用于热量表的智能手机蓝牙抄表的抄收方法,该方法实现使用一部普通的android智能手机实现对热量表的抄读和设置。由于采取通用的智能手机平台,不依赖硬件设备,不需要定制产品,只需要额外加一个蓝牙转串口模块、采用相同的手机操作系统程序代码就可以通用,智能手机平台在编程工具方面都具有很好的扩展性,本方法在功能上扩展性强;智能手机平台在通信通道上有较强的延伸性,能够依照本方法搭建很好的解决方案,进行数据通信等。     

关于出租车载客地点序列推荐技术的研究

在大城市中,出租车已成为实现智能交通运输系统不可或缺的一环。然而,由于一些出租车司机的驾驶经验,和对城市活动的熟悉程度的不足,使得其在寻找乘客时会采取毫无目的的随机漫游策略。这就导致了出租车司机的收益不高,同时也造成了能源的消耗以及环境的污染。针对此问题,将提出出租车载客地点的推荐模型,使得模型给出的推荐地点序列能获得较高的期望收益。具体来说,将基于出租车GPS轨迹数据建立出租车载客地点的马尔科夫决策过程模型,并给出求解该模型的2种算法。仿真实验结果显示,与典型的TopK方法相比,给出的推荐结果能更好地提高单位时间内出租车司机的收益。     

汽车牌照自动识别系统的设计与研制

基于计算机图像处理技术的汽车牌照自动识别系统 ,要求能够将运动中汽车的牌照从复杂背景中准确地提取并识别出来。介绍了所研制的汽车牌照自动识别系统和关键技术 (图像分割与车牌定位、图像二值化和字符提取、车牌字符识别等 )。试验结果显示 ,系统在CeleronⅡ 6 33+12 8M的PC机上 ,对图像尺寸为 76 8× 5 74的 311幅试验图片的识别准确率达到 90 % ,识别时间≤1.5s。