改进YOLOv4的密集遥感目标检测

基于遥感目标在密集分布和背景复杂场景中因特征提取和表达能力的不足而存在漏检和检测效果不佳的问题,提出了改进YOLOv4的遥感目标检测算法.对用于检测目标的锚框(anchor)用K-means聚类算法重新聚类来减少网络计算量;改进特征提取网络结构,引入残差连接取缔网络中连续卷积操作来提高密集目标特征提取能力;在特征提取网络中激活函数加入自适应激活与否的特征激活平滑因子,而在PANet特征融合网络结构中采用Mish激活函数,增强网络对非线性特征的提取能力,从而提升网络的特征提取能力,提高遥感目标在密集分布场景中的检测效果.将所提算法和原始的YOLOv4目标检测算法在遥感图像数据集上进行对比实验,改进YOLOv4算法在实验选用的遥感图像测试数据集上的平均准确率均值(mAP)达到85.05％,与YOLOv4算法相比,mAP提升了5.77个百分点.实验结果表明,在单目标密集分布和多目标混合分布等背景复杂条件下,改进YOLOv4算法具有更好的检测效果.     

改进YOLOv4的密集遥感目标检测

基于遥感目标在密集分布和背景复杂场景中因特征提取和表达能力的不足而存在漏检和检测效果不佳的问题,提出了改进YOLOv4的遥感目标检测算法.对用于检测目标的锚框(anchor)用K-means聚类算法重新聚类来减少网络计算量;改进特征提取网络结构,引入残差连接取缔网络中连续卷积操作来提高密集目标特征提取能力;在特征提取网络中激活函数加入自适应激活与否的特征激活平滑因子,而在PANet特征融合网络结构中采用Mish激活函数,增强网络对非线性特征的提取能力,从而提升网络的特征提取能力,提高遥感目标在密集分布场景中的检测效果.将所提算法和原始的YOLOv4目标检测算法在遥感图像数据集上进行对比实验,改进YOLOv4算法在实验选用的遥感图像测试数据集上的平均准确率均值(mAP)达到85.05％,与YOLOv4算法相比,mAP提升了5.77个百分点.实验结果表明,在单目标密集分布和多目标混合分布等背景复杂条件下,改进YOLOv4算法具有更好的检测效果.     

基于YOLOv7-RS的遥感图像目标检测研究

针对遥感图像目标检测过程中存在的背景复杂、目标特征不明显、小目标排列密集的问题,基于YOLOv7算法,提出了一种改进的遥感图像目标检测算法YOLOv7-RS(YOLOv7-Remote Sensing),提高了遥感图像的目标检测精度。首先,向特征提取网络中融合SimAM减少背景噪声的干扰;其次,提出了D-ELAN网络增强遥感目标的特征提取能力;再次,利用SIOU损失函数以提高算法模型的收敛速度;最后,优化了正负样本分配策略,改善了遥感图像中小目标密集排列时的漏检问题。实验结果表明,YOLOv7-RS在NWPU VHR-10和DOTA数据集上的mAP达到95.4%和74.1%,相较于其他主流算法有了明显提升。     

基于改进YOLOv4的汽车钢铁零件表面缺陷检测

针对YOLOv4在自建的汽车钢铁零件表面缺陷数据集中检测精度不足的问题,利用深度学习的优势,提出一种基于改进YOLOv4的汽车钢铁零件表面缺陷检测方法。首先采用加权K-means算法确定初始anchors预选框,增强anchors框和特征图尺寸的匹配精度,提高检测效率;然后在YOLOv4主干网络的残差单元中引入SE模块,增加有用特征的权重,抑制无效特征的权重来提高检测精度;最后在76×76的特征图后连接RFB-s模块,增强对小目标信息的特征提取能力。实验结果表明,针对自建汽车零件表面缺陷数据集有无缺陷单类检测问题,改进算法比原始YOLOv4的mAP50值提高了4.3个百分点,对小目标具有更好的检测效果。这说明改进算法能满足针对特定的汽车钢铁零件表面缺陷检测问题下的检测速度和精度要求,有效解决了实际问题。针对COCO数据集多分类问题,改进后模型的mAP50值比原始YOLOv4提高了0.2个百分点,FPS值达到20,说明改进算法能够迁移到其他数据集,验证了该算法的泛化性。     

改进YOLOv3的道路小目标检测方法

为了研究传统目标检测算法在进行道路小目标检测时效果不佳及漏检率较高等问题,本文提出了一种基于改进YOLOv3的小目标检测方法.首先通过设计新的特征融合结构降低小目标漏检率,并且使用DIOU损失提高定位精确度.同时对YOLOv3算法中的聚类算法进行改进,采用K-means++算法改进聚类先验框中心点的提取,选取更为合适的Anchor Box,用于提高检测的平均精度和速度.在自制混合数据集上对行人及车辆进行对比检测,在不影响检测速度的情况下,改进的YOLOv3算法能够有效降低小目标物体漏检率,并且提高了检测精度.根据实验结果,本文所提出的改进YOLOv3模型在混合数据集上的平均精度达到92.82%,与未改进的YOLOv3算法相比提高了2.77%.     

面向遥感图像小目标检测的改进YOLOv3算法

针对YOLOv3目标检测算法在遥感图像小目标检测方面精度较低的缺点,提出了一种改进的YOLOv3目标检测算法--YOLOv3-CS。根据对backbone中不同尺度特征重要性的分析重构了backbone,即增加具有丰富位置信息的浅层特征对应的卷积层深度,以此增强backbone对小目标特征的提取能力,引入RFB结构增大浅层特征图的感受野来提升小目标检测精度,优化了anchor boxes及其分配原则。在RSOD数据集的实验结果表明,YOLOv3-CS算法与YOLOv3相比,mAP提高6.49%,F1提高4.85%,所需存储空间降低12.58%,其中backbone的改进和RFB的引入对小目标检测的精度提升较为明显,说明提出的目标检测算法在遥感图像小目标检测方面有较高的优势。     

改进YOLOv5s的小目标烟雾火焰检测算法

针对复杂环境中,烟雾火焰检测存在精度低,小目标检测困难等问题,提出一种改进的基于YOLOv5s的小目标烟雾火焰检测算法。基于公开数据集自建了9 981张不相似的烟雾火焰图像数据集,解决现有数据集的限制,提高了模型的训练效率与泛化能力;在网络中添加3-D注意力机制SimAM,增加算法的特征提取能力,而且没有增加额外的参数;修改网络中的Neck结构,将三尺度检测改为四尺度检测,并结合了加权双向特征金字塔网络（BiFPN）结构,对特征融合过程进行修改,提高小目标的检测能力与特征融合能力;通过遗传算法来优化网络中的部分超参数,进一步模型的检测能力。实验结果表明,改进后的算法比原始YOLOv5s算法平均检测精度提高了7.2%,同时对小目标检测精度更高,误检漏检等情况减少。     

基于加权策略的高分辨率遥感图像目标检测

针对遥感图像目标检测任务中存在的目标尺度差异大、检测精度低等问题,提出了一种基于加权策略的改进YOLOv3遥感图像目标检测模型。为提高对遥感图像中小目标的检测精度,增加具有较小感受野的特征图像的检测分支。设计了一种多尺度特征图像自适应加权融合方法,通过挖掘特征提取网络的表征能力,综合利用多尺度特征提高了目标检测精度。采用DIOR数据集的4类目标构建了一个新的遥感图像目标检测数据集,并进行了改进模型的训练与测试。实验结果表明,改进后的模型取得了80.25%的平均精度均值（mean Average Precision,mAP）,相比于改进前提高了8.2%。将训练模型对RSOD、UCAS-AOD、NWPU VHR-10数据集进行测试,验证了改进模型具有较好的适应性。     

改进YOLOv5的遥感图像目标检测算法

针对遥感图像中背景复杂度高、目标尺寸多样和小目标存在过多所导致的目标检测精度较低的问题,提出一种改进YOLOv5的遥感图像目标检测算法。该算法在主干网络引入通道-全局注意力机制（CGAM）以增强对不同尺度目标的特征提取能力和抑制冗余信息的干扰。引入密集上采样卷积（DUC）模块扩张低分辨率卷积特征图,有效增强不同卷积特征图的融合效果。将改进算法应用于公开遥感数据集RSOD中,改进YOLOv5算法平均精度AP值达到78.5%,较原算法提升了3.1个百分点。实验结果证明,改进后的算法能有效提高遥感图像目标检测精度。     

基于注意力机制和上下文信息的目标检测算法

针对目标检测过程中存在的小目标漏检问题,提出一种基于注意力机制和多尺度上下文信息的改进YOLOv5目标检测算法。首先,在特征提取结构中加入多尺度空洞可分离卷积模块（MDSCM）以提取多尺度特征信息,在增大感受野的同时避免小目标信息的丢失;其次,在主干网络中添加注意力机制,并在通道信息中嵌入位置感知信息,进一步增强算法的特征表达能力;最后,使用Soft-NMS(Soft-Non-Maximum Suppression)代替YOLOv5使用的非极大值抑制（NMS）,降低检测算法的漏检率。实验结果表明,改进算法在PASCAL VOC数据集、DOTA航拍数据集和DIOR光学遥感数据集上的检测精度分别达到了82.80%、71.74%和77.11%,相较于YOLOv5,分别提高了3.70、1.49和2.48个百分点;而且它对图像中小目标的检测效果更好。因此,改进的YOLOv5可以更好地应用到小目标检测场景中。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.