新工科背景下的"人本"教育培养模式

在适应新工科背景下,探索面向成果导向的计算机专业类"人本"人才培养模式,激发学生自身的潜能,帮助他们寻找彼此有别的能力和水平,获得成功、成就和快乐;使学生在完成基本目标达成度的同时,根据自身实际情况做差异选择,得到个性化的培养和指导.多年的实践表明,"人本"教育培养模式,可以有效激发学生自身的学习潜能,有利于学生每一个学习环节的成长和进步.     

基于"实时数字控制"技术的"电力电子技术"实验教学模式研究

"电力电子技术"实验课程是电气工程及其自动化专业重要的实践环节之一.为推进"新工科"背景下人才培养,本文针对目前"电力电子技术"实验课程存在的问题,提出"新工科"背景下电力电子实验课程教学改革方案,通过搭建基于"实时数字控制"的新型教学实验平台,建立面向"新工科"的实验教学新模式,以期加强学生对电力电子技术的理解与掌握,培养学生的实践动手能力,为学生的创新实践提供平台.     

车道线实时检测与偏离预警系统设计与研究

为保证交通安全,设计了一种基于单目视觉的车道偏离检测系统,利用 车载前视摄像 头获取图像,实时对动态图像进行处理,在驾驶员非主观偏离车道时进行报警。首先研 究了图像预处 理技术,包括灰度化、截取有效区域、滤波去噪、图像灰度增强、边缘检测和边缘修复功能 。其次对预处 理后的图像进行车道线检测,为有效识别具有车道线特征的图像,提出了一种改进的Hough 变换算法;对 没有车道线特征或车道线特征不明显的图像,采用了动态检测方法。在此基础上,提出 了一种车道线 纠正算法,即四点标定逆透视变换,将车道图像转化为俯视图,建立图像坐标系与实际俯视 坐标系之间的 关系,得到实际车辆的位置和偏移角度,判断该车辆的情况并作出指示。最后,在实际道路 中对设计中关 键技术以及整个系统进行了实验,大量实验结果表明,本文系统能在多种环境的道路中实现 车道线的准确识别和偏移判断,具有良好的实时性和鲁棒性。     

InP衬底上InAlAs异变缓冲层和高铟组分InGaAs的生长温度优化

利用气态源分子束外延技术在InP衬底上生长了包含InAlAs异变缓冲层的In0.83Ga0.17As外延层.使用不同生长温度方案生长的高铟InGaAs和InAlAs异变缓冲层的特性分别通过高分辨X射线衍射倒易空间图、原子力显微镜、光致发光和霍尔等测量手段进行了表征.结果表明, InAlAs异变缓冲层的生长温度越低, X射线衍射倒易空间图 (004) 反射面沿Qx方向的衍射峰半峰宽就越宽, 外延层和衬底之间的倾角就越大, 同时样品表面粗糙度越高.这意味着材料的缺陷增加, 弛豫不充分.对于生长在具有相同生长温度的InAlAs异变缓冲层上的In0.83Ga0.17As外延层, 采用较高的生长温度时, X射线衍射倒易空间图 (004) 反射面沿Qx方向的衍射峰半峰宽较小, 77K下有更强的光致发光, 但是表面粗糙度会有所增加.这说明生长温度提高后, 材料中的缺陷得到抑制.     

基于稀疏处理的运动目标认知ISAR成像技术

稀疏处理主要研究如何利用低维数据实现高维稀疏信号的准确重建。基于该特性,已有较多学者将其应用于ISAR成像中用以减少数据量,改善成像质量。文中首先从ISAR回波数据出发,建立了基于稀疏处理的ISAR成像模型,并给出实验处理结果;然后,针对稀疏ISAR成像中存在的对目标和环境的自适应能力不强、工作效率不高等问题,提出将稀疏ISAR成像与认知雷达相结合,构建了认知稀疏ISAR成像框图,并给出了两种认知稀疏ISAR成像策略,能够有效减少成像所需数据量,提高雷达利用效率;最后,利用实验数据验证了所提模型的有效性。     

一种基于压缩感知的同频多辐射源数量估计及定位方法

本文提出了一种基于压缩感知的多辐射源数量估计及定位方法,能够较为准确地对未知的多个无线电辐射源的数量估计并定位.方法通过移动监测,在区域内部分位置上获取场强值.在对场强值进行预处理后,利用目标源的空间稀疏性,结合传播模型及压缩感知方法进行粗定位,用较少场强值重构计算出区域内未知同频辐射源数量.在此基础上进行二次定位确定辐射源的位置,提高了定位的准确度.通过对算法进行仿真与实验验证,证明了本文方法的有效性.     

Markov game modeling of mimic defense and defense strategy determination

Network mimic defense technology enhances the robustness of active defense through the redundancy,dynamic and diversity as well as the decision feedback mechanism.However,little work has been done for its security assessment and existing classic game models are not suitable for its dynamic characteristics and lack of universality.A Markov game model was proposed to analyze the transfer relationship between offensive and defensive status and the measurement method of safety and reliability of mimic defense,and calculated the offensive and defensive game equilibrium through non-linear programming algorithm to determine the best defensive strategy considering performance.Experiments give a comparison with the multi-target hiding technique and shows that the mimic defense has a higher defensive effect.Combining with the specific network case,the specific attack and defense path for the exploit of the system vulnerability is given and the effectiveness of the defense strategy algorithm is verified.     

多源红外弱小目标灰色关联融合识别方法

针对从复杂地物背景下识别红外弱小目标的需求,提出了一种针对中/长波红外图像的多源信息融合识别方法。首先在对低信噪比红外图像的预处理中改进了去相关和分块阈值分割等算法以抑制温度场的非线性影响,有效提取出目标及其特征,再利用基于灰色理论的目标关联度计算得到基本概率赋值,进一步运用D-S证据理论组合规则对多个观测样本的信任度进行决策融合,得到同一时刻多传感器探测样本数据的最终识别结果。实验表明,该方法对复杂地物背景下的红外弱小目标具有较高的识别效率。     

Electrode Dependence of Tunneling Electroresistance and Switching Stability in Organic Ferroelectric P(VDF‐TrFE)‐Based Tunnel Junctions

Ferroelectric tunnel junctions (FTJs) are promising candidates for nonvolatile memories and memristor‐based computing circuits. Thus far, most research has focused on FTJs with a perovskite oxide ferroelectric tunnel barrier. As the need for high‐temperature epitaxial film growth challenges the technological application of such inorganic junctions, more easily processable organic ferroelectrics can serve as alternative if large tunneling electroresistance (TER) and good switching durability would persist. This study reports on the performance of FTJs with a spin‐coated ferroelectric P(VDF‐TrFE) copolymer tunnel barrier. The use of three different bottom electrodes, indium tin oxide (ITO), La_0.67Sr_0.33MnO₃, (LSMO), and Nb‐doped SrTiO₃ (STO) are compared and it is shown that the polarity and magnitude of the TER effect depend on their conductivity. The largest TER of up to 10⁷% at room temperature is measured on FTJs with a semiconducting Nb‐doped STO electrode. This large switching effect is attributed to the formation of an extra barrier over the space charge region in the substrate. The organic FTJs exhibit good resistance retention and switching endurance up to 380 K, which is just below the ferroelectric Curie temperature of the P(VDF‐TrFE) barrier.     

Video transmission strategy in multi-rate and multi-node IEEE 802.11 networks

The video transmission strategy VQCW (video queue contention window) was proposed for video transmission fair problem in multi-rate and multi-node IEEE 802.11 networks.The strategy was based on node queue selective packet drop and contention window dynamic adjustment.It deduced a maximum throughput model according to initial contention window size because of the relation between throughput and initial contention window size.This model can provide theoretical upper limit for improving throughput.The theoretical modeling and NS simulation show that the proposed strategy can maintain both video transmission quality and high network overall throughput.