Key Technology of Embedded System Implementation for Software-based CNC System

The software-based computer numerical control（CNC） system includes three types of tasks： periodic real-time tasks, aperiodic real-time tasks, and non-real-time tasks. The tasks are characterized by concurrency, hybridization, and correlation, which make system implementation difficult. The conventional scheduling algorithm can not meet the demands of system implementation in the software-based CNC system completely. The uncertainty factors when running real-time tasks affect control performance by degrading manufacturing accuracy as a result of system resource and processor use restrictions. To address the technical difficulty of embedded system implementation, a novel fuzzy feedback scheduling algorithm based on output jitter of key real-time tasks for a software-based CNC system is proposed. Time characteristics, such as sampling jitter, input-output jitter, and non-schedulability are discussed, followed by quantification through simulations of the impact of time characteristics on manufacturing accuracy. On the basis of this research, the scheduler architecture is designed, and then the algorithm table is calculated. When the system resource changes, the key periodic real-time tasks meet their deadlines by means of dynamically adjusting the task period. The simulated results show that the machining precision rises by an order of magnitude for the proposed scheduler in resource-constrained software-based CNC systems. Moreover, unlike conventional feedback scheduling methods, the algorithm in this paper does not rely on the availability of task execution times and is easy to implement while incurring only a small overhead.

The ternary Ni–Al–Co embedded-atom-method potential for γ/γ Ni-based single-crystal superalloys: Construction and application

An Ni-AI-Co system embedded-atom-method potential is constructed for the γ（Ni）/γ＇（Ni3A1） superalloy based on experiments and first-principles calculations. The stacking fault energies （SFEs） of the Ni（Co, A1） random solid solutions are calculated as a function of the concentrations of Co and A1. The calculated SFEs decrease with increasing concentrations of Co and A1, which is consistent with the experimental results. The embedding energy term in the present potential has an important influence on the SFEs of the random solid solutions. The cross-slip processes of a screw dislocation in homogenous Ni（Co） solid solutions are simulated using the present potential and the nudged elastic band method. The cross-slip activation energies increase with increasing Co concentration, which implies that the creep resistance of γ（Ni） may be improved by the addition of Co.

Night Vision Object Tracking System Using Correlation Aware LSTM-Based Modified Yolo Algorithm

Improved picture quality is critical to the effectiveness of object recog-nition and tracking.The consistency of those photos is impacted by night-video systems because the contrast between high-profile items and different atmospheric conditions,such as mist,fog,dust etc.The pictures then shift in intensity,colour,polarity and consistency.A general challenge for computer vision analyses lies in the horrid appearance of night images in arbitrary illumination and ambient envir-onments.In recent years,target recognition techniques focused on deep learning and machine learning have become standard algorithms for object detection with the exponential growth of computer performance capabilities.However,the iden-tification of objects in the night world also poses further problems because of the distorted backdrop and dim light.The Correlation aware LSTM based YOLO(You Look Only Once)classifier method for exact object recognition and deter-mining its properties under night vision was a major inspiration for this work.In order to create virtual target sets similar to daily environments,we employ night images as inputs;and to obtain high enhanced image using histogram based enhancement and iterative wienerfilter for removing the noise in the image.The process of the feature extraction and feature selection was done for electing the potential features using the Adaptive internal linear embedding(AILE)and uplift linear discriminant analysis(ULDA).The region of interest mask can be segmen-ted using the Recurrent-Phase Level set Segmentation.Finally,we use deep con-volution feature fusion and region of interest pooling to integrate the presently extremely sophisticated quicker Long short term memory based(LSTM)with YOLO method for object tracking system.A range of experimentalfindings demonstrate that our technique achieves high average accuracy with a precision of 99.7%for object detection of SSAN datasets that is considerably more than that of the other standard object detection mechanism.Our approach may therefore satisfy the true demands of night scene target detection applications.We very much believe that our method will help future research.

Qt/Embedded和SQLite下的嵌入式知识库管理方法

嵌入式平台为故障诊断专家系统提供了良好的运行环境。介绍了Qt/Embedded和SQLite在ARM-Linux平台上的运行环境的搭建技术,提出在嵌入式Linux环境下用Qt/Embedded对知识库进行管理的方法。使用Qt/Embedded的数据库驱动连接SQLite创建的嵌入式知识库,构造基于Qt/Embedded数据库访问类的知识对象类来表示和访问知识。实践表明该方法具有较高的可靠性和实用性,取得了良好的效果。

基于XPEmbedded的警务区SMS指挥平台的设计与实现

针对检察机关警务区便携式指挥平台的研发需求,采用普通PC架构、工业手机、XPE进行嵌入式软件开发。基于BASE64编码实现信息的保密传输,编码后通过"自动分割拼接"模块突破SMS单次收发140字节的限制实现顺畅交流。实测表明,这是一种高效、低成本的研发方法。该方法对于实现检察机关信息化"专机专用"应用,有一定的推广价值。

A new image watermarking framework based on levels-directions decomposition in contourlet representation

With the development of digital information technologies,robust watermarking framework is taken into real consideration as a challenging issue in the area of image processing,due to the large applicabilities and its utilities in a number of academic and real environments.There are a wide range of solutions to provide image watermarking frameworks,while each one of them is attempted to address an efficient and applicable idea.In reality,the traditional techniques do not have sufficient merit to realize an accurate application.Due to the fact that the main idea behind the approach is organized based on contourlet representation,the only state-of-the-art materials that are investigated along with an integration of the aforementioned contourlet representation in line with watermarking framework are concentrated to be able to propose the novel and skilled technique.In a word,the main process of the proposed robust watermarking framework is organized to deal with both new embedding and de-embedding processes in the area of contourlet transform to generate watermarked image and the corresponding extracted logo image with high accuracy.In fact,the motivation of the approach is that the suggested complexity can be of novelty,which consists of the contourlet representation,the embedding and the corresponding de-embedding modules and the performance monitoring including an analysis of the watermarked image as well as the extracted logo image.There is also a scrambling module that is working in association with levels-directions decomposition in contourlet embedding mechanism,while a decision maker system is designed to deal with the appropriate number of sub-bands to be embedded in the presence of a series of simulated attacks.The required performance is tangibly considered through an integration of the peak signal-to-noise ratio and the structural similarity indices that are related to watermarked image.And the bit error rate and the normal correlation are considered that are related to the extracted logo analysis,as well.Subsequently,the outcomes are fully analyzed to be competitive with respect to the potential techniques in the image colour models including hue or tint in terms of their shade,saturation or amount of gray and their brightness via value or luminance and also hue,saturation and intensity representations,as long as the performance of the whole of channels are concentrated to be presented.The performance monitoring outcomes indicate that the proposed framework is of significance to be verified.

Identity-Based Steganography in Spatial Domain

This paper proposed an identity-based steganographic scheme, where a receiver with certain authority can recover the secret message ready for him, but cannot detect the existence of other secret messages. The proposed scheme created several separate covert communication channels tagged by the Fuzzy Identity-Based Encryption (FIBE) in one grayscale image. Then each channel is used to embed one secret message by using any content-aware steganographic scheme. Receivers with different attributes can extract different messages corresponded. The Experiments illustrated the feasibility of this identity-based secret message extraction. Further, the proposed scheme presents high undetectability against steganalytic attack launched by receivers without corresponded attributes.

An Embedded Software Modeling and Process by Using Aspect-Oriented Approach

In recent years, mobile devices have become widespread and refined, and they have offered increased convenience in human life. For these reasons, a variety of embedded systems have been designed. Therefore, improving methods for developing of embedded software systematically has become an important issue. Platform-based design is one example of an embedded-system design method that can reduce the design cost via improving a design’s abstraction level. However, platform-based design lacks precise definitions for platforms and design processes. This paper provides an approach that combines the aspects and platform-based design methods for developing embedded software. The approach is built on platform-based design methodology and uses the separating of concerns (SoC) concept to define the aspects and to reduce the crosscutting concerns in embedded system modeling. For aspect issues, we use the extended UML notation with aspects to describe both the static structure and the dynamic structure of the embedded system. We used an example of a digital photo frame system to demonstrate our approach.

The Superconductivity in Fe-Based Family of Superconductors and Its Electronic Structure Analysis in Presence of Dopants Rh and Pd

The discovered in 2008 Fe-based superconductors (SC) are a paramagnetic semimetal at ambient temperature and in some cases they become superconductor upon doping. In spite of so many years since its discovery it is still not known the mechanism that leads to superconductivity. The electronic structure study is used for determining key features of the SC mechanism in these materials. The calculations were performed using the modern suite of programs MOLPRO 2021. We performed quantum calculations of a cluster embedded in a background charge distribution that represents the infinite crystal. The Natural Population Analysis was used for determining the charge and spin distribution in the studied materials. As follows from our results, the possible mechanism for superconductivity corresponds to the RVB theory proposed by Anderson for high Tc superconductivity in cuprates.

中国社区嵌入式养老:现状与问题浅析

为实现全体老年人享有基本养老服务的目标,社区嵌入式是未来中国养老服务发展的重点方向。社区嵌入式养老是指通过下沉与整合各类服务资源,在社区内打造集居家、社区、机构服务为一体的养老综合体,以实现在家中或家门口就近就便享受优质养老服务的一种新型养老模式。基于嵌入性的理论视角,研究从需求嵌入、资源嵌入、主体嵌入与理念嵌入四个维度构建了中国社区嵌入式养老的制度框架,并对当前社区嵌入式养老的服务项目、服务设施及运营模式进行了系统归纳。研究发现中国社区嵌入式养老发展面临着多维度的嵌入问题,这集中表现为:供需关系存在错位,缺乏有效链接机制;专业服务人才有限,服务品质良莠不齐;权责利益交织纵横,多方主体协同困难;地区基础存在差异,经验范式推广受阻等。基于此,建议政府、社区、企业及社会组织等应进一步明晰主体职责定位,结合地区特点,依托有利资源,合力推动社区嵌入式养老实现高质量发展。

考虑轴力与底板约束的埋入式钢柱脚刚度模型

为准确预测埋入式(特别是浅埋)钢柱脚节点的初始转动刚度,将柱脚的埋入段简化为地基梁,基于初参数法完善考虑轴力影响的Winkler地基上的Timoshenko梁理论,提出受锚栓和混凝土约束的柱脚底板转动刚度的计算方法,进而建立可以综合反映柱脚埋深、埋入段剪切变形、钢柱轴力、底板约束影响的埋入式钢柱脚转动刚度模型。基于已验证的有限元模型进行参数分析,研究埋深比、轴力和锚栓布置对柱脚转动刚度的影响。与有限元结果的对比表明,提出的刚度模型较过往文献中理论模型具有更高的精度和更好的适用性,尤其是对于埋深比为0.5~1.5的浅埋柱脚节点。理论与有限元结果表明:埋深比较小时,柱脚转动刚度随埋深比的增加快速增大,而埋深比增加到一定程度后,其对转动刚度几乎无影响;柱脚转动刚度随钢柱轴压力增加呈增大的趋势;对于浅埋柱脚节点,底板约束对其转动刚度的影响较大,而随着埋深的增大,其影响逐渐减小;底板转动约束对埋深比小于1.5的节点刚度具有显著影响,当埋深比增大至2.5,其影响可以忽略。

基于局部-邻域图信息与注意力机制的会话推荐

针对基于匿名用户的会话推荐忽略了不同会话之间可能存在的协作信息,以及未考虑所预测的目标项与历史行为的相关性问题,提出一种基于局部-邻域图信息与注意力机制的会话推荐模型(SR-LNG-AM)。从当前会话和邻域会话构建的图结构中分别学习两种类型的项目转换信息,将其融合得到项目嵌入。使用软注意力机制生成全局嵌入,使用目标注意力机制针对不同的目标项自适应生成不同的目标嵌入。结合局部嵌入,进行预测。在两个真实数据集上与多个基线方法进行实验对比,实验指标均有提高,验证了该方法的有效性。

面向方面情感分析的多通道增强图卷积网络

传统的基于单通道的特征提取方式,仅使用单一的依赖关系捕获特征,忽略单词间的语义相似性与依赖关系类型信息。尽管基于图卷积网络进行方面情感分析的方法已经取得一定成效,但始终难以同时聚合节点的语义信息和句法结构特征,在整个迭代训练过程中最初的语义特征会逐渐遗失,影响句子最终的情感分类效果。由于缺乏先验知识会导致模型对相关情感词的误解,因此需要引入外部知识来丰富文本信息。目前,如何利用图神经网络(GNN)融合句法和语义特征的方式仍值得深入研究。针对上述问题,该文提出一种多通道增强图卷积网络模型。首先,通过对情感知识和依赖类型增强的句法图进行图卷积操作,得到基于语法的两种表示,与经过多头注意力和图卷积学习到的语义表示进行融合,使多通道的特征能够互补学习。实验结果表明,在5个公开数据集上,准确率和宏F1值优于基准模型。由此可见,依赖类型和情感知识均对增强句法图有重要影响,表明融合语义信息与句法结构的有效性。

基于OBE理念的嵌入式系统实践教学改革探索

嵌入式系统实践是计算机科学与技术专业的一门专业实践课程。在工程教育专业认证和一流本科课程建设背景下,针对传统嵌入式系统实践教学脱离企业用人需求、缺乏个性化教学、硬件平台跟不上等问题,文章以OBE理念为核心,围绕产学合作、跨学科融合,结合分层次和多元化教学方式,提出了一种融入OBE理念的嵌入式系统实践教学改革方案,可实现对学生多维度、全方位、全过程的教育,帮助学生全面发展技术能力、解决问题的能力,以及团队合作能力,从而更好地适应工程领域的需求。

基于OBE理念的高等医学院校图书馆嵌入创新创业教育研究

成果导向教育(OBE)是一种以学生为中心、学习成果为导向的先进教育理念,将其应用于信息素养教育和创新创业教育可以更好地提高医学生的综合素质。文章从医学生信息素养对其创新创业的影响、图书馆嵌入创新创业教育的意义、基于OBE理念图书馆嵌入创新创业教育的模式构建等方面进行探究,提出信息素养教育与创新创业教育、医学专业教育的融合,可使医学生的创新创业更有针对性、实效性。

深圳岗厦北综合交通枢纽大尺寸钢管混凝土半埋 入式柱脚性能试验研究

深圳岗厦北综合交通枢纽位于地下空间资源紧张的城市核心区,规模巨大且荷载工况复杂,核心换乘区设有51.2m×48.0m的无柱超大跨中庭。为解决由场地条件限制导致的柱脚埋深不足问题,结合已有研究成果和工程实践经验,依托深圳岗厦北综合交通枢纽,提出并设计了半埋入式钢管混凝土柱脚节点。为检验节点可靠性,通过1/5大比例缩尺模型试验结合数值分析研究了轴力、剪力和弯矩共同作用下的半埋入式柱脚节点的力学响应,分析了柱脚内部的应力分布规律,揭示了同时设置环板和栓钉作为抗剪连接件时的工作机理。分析结果表明:设计荷载工况下,钢管混凝土柱轴力主要通过环板和柱脚底板传递,弯矩主要通过钢管侧壁承压传递;环板埋深较浅时可以获得较高的传力效率,但其下部混凝土易出现应力集中;钢管侧壁栓钉在埋置深度范围内均能够较好地发挥抗剪作用。承台下部桩基布置合理,设计荷载工况下未见承台冲切破坏特征、节点整体处于弹性工作状态;1.2倍设计荷载工况下节点刚度仍未见明显退化,节点混凝土未出现压溃或剥落,表面无可见裂缝发展,各关键位置钢材应力低于材料强度。设置环板和栓钉作为剪力连接件的半埋入式柱脚可以实现对钢管混凝土柱的可靠嵌固,提出的采用抗剪环板加强的钢管混凝土半埋入式柱脚节点设计与构造方案合理可行,满足结构安全要求。

国外某铁锰矿工艺矿物学特性及分离利用技术研究

我国锰矿进口来源相对单一,对外依存度超过90%。我国锰矿资源丰富,但以低品位的贫锰矿资源为主,铁含量超标,而且矿物组成复杂、共伴生关系密切、矿物之间可选性差异小,分离难度大。为了更好地开发利用铁锰矿资源,采用化学成分分析、SEM、MLA、X射线衍射分析等检测方法对国外某铁锰矿进行工艺矿物学研究,并对该矿石进行了分离回收探索试验。结果表明,矿石中TFe品位为31.31%,Mn品位为9.09%,主要杂质元素SiO2含量为28.73%;矿石中主要有用矿物为褐铁矿、铅锰矿、硬锰矿,含量分别为49.57%、8.60%、6.44%;脉石矿物为石英和重晶石,含量分别为29.01和6.24%。矿石中铅锰矿和硬锰矿的粒度较细,-38μm粒级分布率分别达到了74.59%和62.54%,且单体解离度较低,仅为16.75%和15.12%;铅锰矿和硬锰矿主要以连生体存在,贫、富连生体含量均在40%以上;该二者与褐铁矿嵌布关系较为紧密,铅锰矿颗粒多数以细粒包裹体存在于褐铁矿,硬锰矿颗粒多数呈包裹体或浸染状存在于褐铁矿中,铁锰矿物解离较为困难。因此传统选矿方法很难实现铁锰矿物的有效分离。采用“氢基矿相转化—磁选”技术处理该矿石,可获得铁精矿产率54.08%、铁品位58.35%、铁回收率91.47%的技术指标。

基于知识的复杂产品装配工艺快速编制方法

针对复杂产品装配工艺设计过程中存在的编制效率低、质量波动大、自动化和智能化程度低等问题,提出一种面向语义的知识实例检索和复用的装配工艺快速编制方法。分析复杂产品装配工艺业务流程,建立基于知识检索层和知识实例层的双层装配工艺知识模型,从内容、类型、功能及应用方向对知识进行分类。在此基础上,针对已有的知识实例,提出基于Sentence-BERT句向量模型的工艺文档语义分析方法,结合余弦相似度算法给出了工艺知识的语义检索方法,实现知识在装配工艺设计流程中的快速复用。以某航天产品为例,开发航天产品装配工艺快速设计管理系统,构建装配工艺知识库,并在某制造企业上线运行,验证所提方法的可行性,使工艺编制效率大幅提升。

基于汉字形音义多元知识和标签嵌入的文本语义匹配模型

文本语义匹配指基于给定的文本判别文本之间的语义关系。针对该任务,现有模型的信息编码未考虑利用除汉字字符外的潜在语义信息,且在分类时未考虑标签信息对模型性能的影响。因此,该文提出了一种使用汉字形音义多元知识和标签嵌入的文本语义匹配方法。首先,通过信息编码层对汉字的形音义的多元知识进行编码;其次,通过信息整合层获取融合汉字形音义多元知识的联合表示;然后,经过标签嵌入层利用编码后的分类标签与汉字形音义的联合表示生成信号监督标签;最后,经过标签预测层获取文本层面与标签层面的联合信息表示,进而对文本语义关系进行最终的判别。在多个数据集上的实验结果显示,该文提出的模型优于多个基线模型,验证了模型的有效性。

一种基于扼流结构的基站天线碗状振子异频去耦方法

针对双频嵌入式布局的基站天线中存在高频振子辐射性能受低频振子严重干扰的问题,提出一种基于扼流结构的基站天线碗状振子异频去耦方法。设计了含去耦结构的基站天线,在低频振子臂上加载微带形式的扼流结构,通过分析扼流结构的等效电路、在高频天线工作频段的感应电流及单站雷达散射截面(Radar Cross-Section,RCS),调整扼流结构的性能参数,有效降低低频振子对高频振子的影响。通过设计具有去耦功能的双频双极化基站天线阵列,验证所提方法的可行性。结果表明,低频振子具有良好的阻抗匹配特性,所提方法能有效减弱高频振子受低频振子影响导致的交叉极化恶化问题,且能够稳定方向图波束宽度。