基于视觉感知机制的织物疵点轮廓检测

针对传统人工织物疵点检测存在的误检及低效等问题,提出了一种基于视觉感知机制的自适应织物疵点轮廓检测方法.首先,模拟视觉系统中视网膜感受野对视觉信息的处理机制对织物疵点图像进行滤波及疵点增强;其次,依据初级视皮层(V1)区对视觉信息响应的方向选择性机制构建织物疵点图像边缘检测模型,实现对织物疵点图像的边缘检测.最后,采用自适应阈值选择的方法对检测到的边缘进行二次处理,获得织物图像疵点的轮廓.为验证本文方法的有效性和准确性,对4类织物疵点图像进行测试,并定性和定量两方面进行比较分析,结果表明文中提出的方法能够较好地检测出织物疵点轮廓信息,不仅可以得到质量较高的织物疵点轮廓图像,而且在整个检测过程中能够自适应的选择参数,避免受人的主观因素影响,具有实际的应用价值.     

无人机群目标搜索的主动感知方法

为提升蚁群搜索算法在规模大的栅格环境中对未知目标的搜索效率,提出基于蚁群算法的主动感知搜索框架。该框架通过应用历史环境信息来选择无人机的运动方式,并由无人机运动方式和感知域信息得到新的环境信息,从而实现无人机群的智能自动化搜索功能。新方法计算出一种具有探索偏好的未搜索概率,可使无人机搜索时偏向未搜索程度高的栅格,以此来提高算法的搜索能力。同时,以未搜索概率和信息素作为运动方式决策的依据来建立一种新的运动方式选择机制。该机制不仅考虑了目标可能出现的区域,又可兼顾未知区域,从而可实现无目标先验信息条件下的搜索过程。仿真结果表明,此算法在规模大的栅格环境中,与现有算法相比具有更高的搜索效率,并且得到的目标分布信息将更加全面。     

Symbol error probability of an OFDM receiver with pulse blanking based on the peak value threshold

Pulse blanking based on the peak value threshold is a widely used method to eliminate impulsive interference in the orthogonal frequency division multiplexing (OFDM) receiver. To assess the impact of pulse blanking on the link transmission reliability of the OFDM receiver, the analytical expression for the signal-to-noise ratio (SNR) of the OFDM receiver with pulse blanking based on the peak value threshold is derived in the frequency selective fading channel. According to this analysis, the calculation method for symbol error probability is given in this paper. Computer simulation indicates that theory accords with simulation and validates the accuracy of theoretical analysis.     

基于大数据挖掘的终端感知与换机应用研究

通过对移动大数据的分析和挖掘,能够提升终端感知,并为用户换机推荐提供强有力的数据支持。基于早期终端营销存在的问题与不足,提出了基于大数据挖掘的终端感知与换机应用系统解决方案,具体包括基于聚类算法的隐性换机用户提取方法,基于神经网络的指标分析法,基于决策树的换机预测方法。     

多层激光雷达在无人驾驶车中的环境感知

为了使无人驾驶车获得可行驶区域和障碍物信息,通过分析大量激光雷达扫描点数据,总结并得出路沿数据点独有的特征,提出一种基于路沿数据点特征和多层融合技术的路沿检测算法.应用Dezert-Smarandache理论(Dezert-Smarandache theory,DSm T)对无人驾驶车前方道路环境建立栅格地图,并利用证据理论中的冲突系数检测动态障碍物.最后,采用膨胀算法、侵蚀算法和改进的八邻域区域标记算法对动态障碍物进行聚类和信息提取.实车实验结果表明:本算法可稳定、准确地感知无人驾驶车周围环境信息.     

基于符号对称性的半符号OFDM调制方法

在分析OFDM调制符号对称性的基础上, 结合正交上下变频技术, 提出了一种基于符号对称性的半符号OFDM(HS-OFDM)调制方法, 分析了系统的误码性能和频谱效率, 给出了一种抗多径干扰的调制符号设计方法, 并对理论分析进行了仿真验证. 该半符号调制方法适用于子载波采用BPSK或PAM调制的OFDM系统, 可将系统的频谱效率极限值提高至2 Baud/Hz, 为更高效调制技术的研究提供了一个突破口.     

多模盲均衡算法剩余码间干扰的近似表达式简

A closed approximated formed expression for the achievable residual inter-symbol interference(ISI) is proposed for the adaptive equalizers that adopt the multimodulus algorithm. The expression depends on the step-size parameter, equalizer's tap length, input signal statistics, signal noise ratio and channel power. Simulation proves that the expression shows the exact relationship between residual inter-symbol interference and involved parameters. Since the channel power and signal noise ratio of the expression are measurable or can be calculated, this new approximated expression can be a useful tool for choosing the step-size and tap length for designing an equalizer, and for making direct performance comparison between blind equalizers based on distinct algorithms.     

旅游法实施背景下网友对“导游员”工作的感知——基于新浪微博文本分析

以2013年国庆期间新浪微博网友关于“旅游法”和“导游”的原创微博为样本,采用数量分析方法,分析网友对旅游法实施后导游工作关注程度的变化以及对旅游法的支持程度,研究表明,国庆期间网友对旅游法实施后导游工作的关注日益增加,认为旅游法的实施对导游工作有正面影响的网友占大多数.使用词频统计法和共现分析法进行内容分析,网友对导游工作的感知主要包括：导游工作需要旅行社和游客的支持和理解;支持旅游法对无证导游的惩罚,但是惩罚力度不足;旅游法对强制消费的约束已初见成效,但部分网友表现出对部分导游工作态度消极的不满;旅游法实施后导游收入下降明显.     

A Hybrid Color Quantization Algorithm Incorporating a Human Visual Perception Model

Color quantization is a common image processing technique where full color images are to be displayed using a limited palette of colors. The choice of a good palette is crucial as it directly determines the quality of the resulting image. Standard quantization approaches aim to minimize the mean squared error (MSE) between the original and the quantized image, which does not correspond well to how humans perceive the image differences. In this article, we introduce a color quantization algorithm that hybridizes an optimization scheme based with an image quality metric that mimics the human visual system. Rather than minimizing the MSE, its objective is to maximize the image fidelity as evaluated by S‐CIELAB, an image quality metric that has been shown to work well for various image processing tasks. In particular, we employ a variant of simulated annealing with the objective function describing the S‐CIELAB image quality of the quantized image compared with its original. Experimental results based on a set of standard images demonstrate the superiority of our approach in terms of achieved image quality.