基于改进显著图的高效裂纹检测算法

裂纹检测对于确保设施和设备的安全运行非常重要。然而现有的裂纹检测方法数据标注困难,且训练时间长,检测速度慢。针对这些问题,提出一种基于改进显著图的裂纹检测算法,应用卷积神经网络提取的特征计算出图像中裂纹的位置,从而实现裂纹检测。该算法解决了裂纹检测算法数据标注困难的问题;训练时间短,使用两块k80显卡训练时间仅为23 min;检测速度快,具有105 帧/s的检测速度;同时在自制数据集上达到了52%的平均精度,验证了该算法的有效性。     

基于机器视觉的螺纹零件头部裂纹检测

将数字图像处理技术应用于螺纹零件头部裂纹的检测,构建基于机器视觉的螺纹零件头部裂纹检测系统。对采集的螺纹零件头部图像进行预处理、感兴趣区域定位,边缘检测、特征提取以及形态学处理,提出针对螺纹零件头部裂纹特征的检测方法。实验表明,方法具有识别精度高、可靠性强等优点,完全能满足工业生产中裂纹检测的要求。     

基于数字图像处理的表面裂纹检测算法

本文提出了一种基于数字图像处理技术的表面裂纹检测算法。运用这种算法能精确的检测裂纹的位置、长度等特征，将这种裂纹检测算法运用到裂纹自动检测系统以及裂纹扩展行为监测中不仅大大降低了劳动时间和劳动强度，而且提高了测量的准确性。     

飞机发动机叶片裂纹自适应检测算法的研究

发动机叶片裂纹检测是机务维护的重要内容,能否快速准确地检测叶片裂纹,对于缩短战场抢修时间、保障飞机的完好率具有重要的意义.本研究采用基于边缘检测的小波滤波和自适应阈值分割算法,实现叶片裂纹的自适应快速检测;基于边缘检测的小波滤波方法能动态的确定分解层次,有效抑制了噪声点的影响,提高了图像的视觉效果;自适应阈值分割是通过迭代的方法寻找图像的最佳分割阈值,能自动、可靠地检测裂纹的位置、长度等特征.仿真结果验证了这种检测算法的有效性,能满足外场对发动机叶片裂纹检测的要求.     

VC++与Matlab混合编程及其在轮辋裂纹检测中的应用

文中结合轮辋裂纹检测系统介绍了几种VC＋＋与Matlab混合编程的方式，并具体分析了它们在轮辋裂纹检测中的可行性，得出了在轮辋裂纹检测中可以采用Matlab引擎的结论。最后结合边缘检测、形态学运算、最优阈值分割等多种方法，采用Matlab引擎较好地实现了轮辋裂纹检测，取得了理想的效果。实验表明该方法在轮辋裂纹检测系统的开发中大大提高了编程效率。     

VC++与Matlab混合编程及其在轮辋裂纹检测中的应用

文中结合轮辋裂纹检测系统介绍了几种VC 与Matlab混合编程的方式,并具体分析了它们在轮辋裂纹检测中的可行性,得出了在轮辋裂纹检测中可以采用Matlab引擎的结论。最后结合边缘检测、形态学运算、最优阈值分割等多种方法,采用Matlab引擎较好地实现了轮辋裂纹检测,取得了理想的效果。实验表明该方法在轮辋裂纹检测系统的开发中大大提高了编程效率。     

大型抽水蓄能机组顶盖螺栓裂纹原位在线检测技术研究

水轮机顶盖螺栓是连接水轮机顶盖与座环的重要连接件,其安全状态对水电站安全运行至关重要。超声波在金属内部具有透射深度大、反射率高的特点,可用于检测螺栓内部疲劳裂纹,但常规的超声检测必须在螺栓解体拆出状态下才能进行,否则无法保证裂纹的检出。为了有效监测运行状态下的顶盖螺栓裂纹和损伤情况,本文提出了一种基于压电阵列的超声波传感器,通过压电晶片的分区非均匀激发,形成偏心扇形超声声场,并通过对接收信号进行数字处理,实现水轮机顶盖大型螺栓裂纹的原位在线检测。该技术具有实时性强、精度高、可靠性好等优点,能够有效地在线监测水轮机顶盖大型螺栓的裂纹和损伤情况,为水电站安全运行提供重要保障。     

航空发动机篦齿盘的原位无损检测

针对某型航空发动机篦齿盘上产生的裂纹缺陷,在不拆分发动机的前提下,提出采用内窥涡流集成化的方法对篦齿盘进行原位无损检测;设计了一种新型篦齿盘裂纹缺陷检测专用涡流传感器,将其与内窥探头集成在一起,研制了一种可用于航空发动机篦齿盘原位检测的内窥涡流集成化检测探头;采用内窥涡流集成化检测技术在修理厂对含有裂纹缺陷的篦齿盘进行了对比检测实验和原位探伤实验,实验结果表明:内窥涡流集成化检测技术实现了航空发动机篦齿盘裂纹缺陷的原位无损检测,具有很高的检测准确率。     

面向复杂光照条件的桥底裂纹检测与测量算法研究

桥梁底面裂纹隐蔽且不易观察,利用仰视摄像头自动检测桥梁底面裂纹对桥梁的安全监测具有重要的作用.和桥面裂纹检测的摄像头位置不同,桥底面检测的摄像头仰视观测裂纹受到桥墩等遮挡、环境光照反光等复杂的光照影响,现有的裂纹检测算法性能难以满足实际应用需求.针对这一问题,文章提出了一种光照鲁棒性的桥底裂纹检测与测量算法,首先利用全局自适应光照调整采集图像的亮度,然后利用多幅图像拼接获得底面的全横截面图像对桥底面可视化,最后提出增强型的边缘检测算法分割出裂纹的边缘位置,并利用裂纹的几何结构进行优化,在此基础上计算出裂纹的长度和宽度,实现裂纹的自动检测和测量.实验数据表明,文章提出的算法在裂纹检测的准确度上优于对比算法,表明了该算法在实际场景中的有效性.     

金属管道缺陷的微波检测

本文提出了一种用微波来检测金属管道裂纹、裂缝和表面金属异物等缺陷的一种新方法。文中详细介绍了微波检测金属管道裂纹、裂缝的原理和特征信号的提取方法，并用实验验证了该方法的正确性。     

Efficient Development of Lexical Language Resources and their Representation

Statistical approaches in speech technology, whether used for statistical language models, trees, hidden Markov models or neural networks, represent the driving forces for the creation of language resources (LR), e.g., text corpora, pronunciation and morphology lexicons, and speech databases. This paper presents a system architecture for the rapid construction of morphologic and phonetic lexicons, two of the most important written language resources for the development of ASR (automatic speech recognition) and TTS (text-to-speech) systems. The presented architecture is modular and is particularly suitable for the development of written language resources for inflectional languages. In this paper an implementation is presented for the Slovenian language. The integrated graphic user interface focuses on the morphological and phonetic aspects of language and allows experts to produce good performances during analysis. In multilingual TTS systems, many extensive external written language resources are used, especially in the text processing part. It is very important, therefore, that representation of these resources is time and space efficient. It is also very important that language resources for new languages can be easily incorporated into the system, without modifying the common algorithms developed for multiple languages. In this regard the use of large external language resources (e.g., morphology and phonetic lexicons) represent an important problem because of the required space and slow look-up time. This paper presents a method and its results for compiling large lexicons, using examples for compiling German phonetic and morphology lexicons (CISLEX), and Slovenian phonetic (SIflex) and morphology (SImlex) lexicons, into corresponding finite-state transducers (FSTs). The German lexicons consisted of about 300,000 words, SIflex consisted of about 60,000 and SImlex of about 600,000 words (where 40,000 words were used for representation using finite-state transducers). Representation of large lexicons using finite-state transducers is mainly motivated by considerations of space and time efficiency. A great reduction in size and optimal access time was achieved for all lexicons. The starting size for the German phonetic lexicon was 12.53 MB and 18.49 MB for the morphology lexicon. The starting size for the Slovenian phonetic lexicon was 1.8 MB and 1.4 MB for the morphology lexicon. The final size of the corresponding FSTs was 2.78 MB for the German phonetic lexicon, 6.33 MB for the German morphology lexicon, 253 KB for SIflex and 662 KB for the SImlex lexicon. The achieved look-up time is optimal, since it only depends on the length of the input word and not on the size of the lexicon. Integration of lexicons for new languages into the multilingual TTS system is easy when using such representations and does not require any changes in the algorithms used for such lexicons.     

非合作航天器自主相对导航研究综述

非合作航天器自主相对导航作为与非合作航天器实现空间交会对接过程中的关键技术,是在轨服务技术的重点发展方向之一,其研究具有重要的理论价值与工程意义.针对在轨服务任务对于自主相对精确导航的需求,本文对发展非合作航天器自主相对导航技术的必要性进行了阐述.首先总结了非合作航天器自主相对导航技术的内涵与研究现状;随后分析梳理了非合作航天器自主相对导航过程涉及到的光学敏感器、位姿测量、导航滤波器以及地面实验等关键技术.最后根据研究现状和关键技术的分析指出了非合作航天器自主相对导航目前存在的主要问题并给出后续发展的建议.     

基于约束的XML文档规范化算法

XML模式设计是XML数据库设计的关键．基于XML文档的基本概念给出了XML部分函数依赖、传递函数依赖、XML范式、XML第1到第3范式以及DTD无损联接分解的相关定义,提出XML模式规范化转换规则,给出无损联接分解的两种规范化算法,对算法的正确性、可终止性和时间复杂性进行了证明分析,并实验证明了规范化后的文档查询和存储效率有明显的提高．这将对未来的XML函数依赖保持、XML多值依赖以及XML模式设计的进一步规范化研究奠定理论基础．     

基于物联网技术的智能家居椅控制系统设计

针对国内外智能家居椅控制系统二次开发难度大、接口兼容性差等问题,基于物联网技术,对现有智能家居椅控制系统进行了二次开发。采用STM32控制器对智能家居椅控制系统的输入输出接口进行扩展,引入压力传感器、S型称重传感器、光电探测器对家居椅各个执行机构进行监测,开发了基于Java语言的微信客户端应用(APP)程序,实现了智能家居椅捶背力度调节、复合机构助起、阅读灯亮度调节等远程智能操控。智能家居椅捶背控制试验表明,捶背次数控制成功率约85.49%,捶背力度控制成功率约86.50%。复合机构助起试验表明,助起控制成功率约90%。阅读灯亮度调节试验表明,亮度调节成功率可达88.46%,系统可控性较高。采用物联网技术对智能家居椅控制系统进行了创新性设计,二次开发的控制系统可为互联网+智能家居的设计提供参考。     

电子对抗装备维修管理自动化研究

论文分析了电子对抗装备维修管理自动化研究的背景,从发展模式、维修能力和维修流程三个方面论述电子对抗装备维修管理自动化的特征,提出了相应的研究理念与对象;叙述了电子对抗装备维修管理自动化研究内容,主要包括基础技术、电子对抗装备故障智能诊断系统、电子对抗装备维修决策系统、电子对抗装备维修管理绩效评价系统和电子对抗装备维修管理自动化信息集成平台。     

关于计算机科学与技术认知问题的研究简报（Ⅰ，Ⅱ）

计算机科学与技术的认知对学科的科学研究与人才培养具有重要的意义,对计算机科学与技术学科发展的主线、特点和内在规律进行了回顾与总结,从科学哲学的角度阐述了学科的一系列认知问题,并概要介绍了学科方法论研究的主要进展,讨论了学科方法论研究进展对学科未来发展和人才培养可能产生的影响。     

基于MATLAB的化工单元操作图形演示模块的开发

针对化工单元操作中一些难以用文字描述清楚的重、难点问题,利用MATLAB图形演示器的强大功能,开发了化工单元操作图形演示模块。用户可以通过观看相应的图形演示,明确如梯级图解法确定精馏塔理论板层数、在焓湿图上如何确定空气状态点等重要问题的处理方法及重要概念的物理意义,从而深化对化工单元操作原理的理解。演示界面能动态显示问题的求解过程,并设有开放式的结构,因此具有很强的灵活性,适合于本科生、研究生及工程技术人员的学习使用。     

Meme Media for Clipping and Combining Web Resources

The publication and reuse of intellectual resources using the Web technologies provide no support for us to clip out any portion of Web pages, to combine them together for their local reuse, nor to publish the newly composed object as a new Web page for its reuse by other people. This paper shows how the meme-media architecture is applied to the Web to provide such support for us. This makes the Web work as a shared repository not only for publishing intellectual resources, but also for their collaborative reediting. We will propose a general framework for clipping arbitrary Web contents as live objects, for defining IO ports on such a clip, and for the recombination and linkage of such clips based on both the original and some user-defined relationships among them. In our previous works, we proposed two separate frameworks for these three purposes; one works for the first two, and the other for the last. Here we will propose a unified framework for these three purposes, as well as its detailed internal mechanisms. Then we show how it can be easily applied to various legacy Web applications to develop innovative services.     

Estimating the Attraction Domain for the Boost Inverter

This work presents an approach for estimating the domain of attraction for polynomial systems with state and control‐signal constraints, including saturation. In many problems, it is possible to derive global stability properties for such systems, neglecting constraints. Consideration of the constraints usually makes the problem much more complicated. In this paper, the stability analysis performed for the unconstrained case is used for the problem as a whole. For application of the method, there are powerful computational tools that can be employed in cases of polynomial systems. The technique is not only valid for the analysis of equilibrium points, but also for other attractors, such as limit cycles. As examples, the domain of attraction for given control laws is estimated for both a nonlinear DC‐DC boost converter and for a boost inverter.     

Compact disc standards: an introductory overview

The success of the compact disc (CD) as a storage medium for digital audio has, over the last ten years, resulted in a number of initiatives to use the CD for other applications as well, e.g., as read-only memory for computers, as a storage medium for audio-visual material for multimedia applications, and as a storage medium for photographs. Each of these applications poses additional requirements on how the corresponding information is stored and retrieved, resulting in a range of different CD standards. The functional specifications of these standards are each given a specific color for ease of reference: the Red Book for CD-DA, the Yellow Book for CD-ROM, the Green Book for CD-I, etc. This paper aims at giving an overview of the various CD standards by explaining what is specified in each of the colored books and by indicating how they relate to one another.