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为实现对供热管道泄漏的检测,研究了基于声压传感器的供热管道泄漏检测方法。首先利用PCB公司的声压传感器和NI cDAQ搭建了实验平台,并在现场进行了泄漏检测实验;研究了长输大口径供热管道泄漏声压脉动信号特征,并对db小波、sym小波、haar小波处理含噪声管道声压信号的去噪能力进行比较。虽然在处理实验室小规模管道模型泄漏信号时db小波和sym小波取得了较好的效果,但它们无法有效滤除大口径长输供热管道泄漏信号中的噪声信号。通过对比发现,haar小波去噪方式能较好地应用于长输大口径供热管道的信号滤波中。因此,基于音波法的泄漏检测方法适用于长输大口径供热管道的泄漏检测。提出的方法对于长输大口径供热管道泄漏检测有较好的效果,在工业生产中将取得一定的经济效益。 相似文献
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李华杰 《计算技术与自动化》2016,(3):63-67
长输管道的泄漏检测和定位对管道安全平稳运行意义极其重大,在以软件计算为主的检测方法里,模糊神经网络模型综合了模糊算法和神经网络模型的优点,能较好地适应长输管道的非线性特征。本文采用中亚地区某管道某相邻两站场的历史数据训练基于高木-关野(Takagi-Sugeno)模糊神经网络的预测模型,使用STONER管道仿真软件产生实时数据,用一种较简单的软方法较好的实现管道泄漏定位,该种方法对中亚某长输管道这类没有专门硬件泄漏检测设备和系统的管线有一定的实用意义。 相似文献
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在分析语音信号与噪声在高低频带的能量谱表现特征基础上,提出一种低信噪比条件下采用高低频带对数能量谱比贝叶斯决策的语音端点检测方法.首先根据样本计算语音信号和背景噪声在高低两个不同频带的对数能量谱比值,依据最大似然估计得到两类信号对数能量谱比的统计分布,并基于贝叶斯决策准则推导最佳判决阈值.信号输入时,逐帧计算高低频带对数能量谱比并与判决阈值进行比较来进行语音和背景噪声的分类判决,从而实现语音信号的端点检测.实验结果表明,与传统的双门限检测法和谱熵检测法相比,提出的方法在较低信噪比条件下能更加准确地检测语音端点,明显提高了端点检测的准确率和速度. 相似文献
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《计算机科学与探索》2019,(9):1534-1542
语音端点检测是语音信号处理的基础,为了提高在低信噪比及非平稳噪声下语音端点检测的准确性,提出了一种基于长时信号功率谱变化的语音特征,利用阈值判决法验证了这一特征在语音端点检测中的应用前景。该方法首先统计信号在长时段下功率谱的变化量;然后进行阈值判决,在初始化后可依据每次的判决结果自适应更新阈值;最后通过投票决策机制来判定当前是否为语音帧。仿真结果表明,与两种经典的基于长时特征(长时段信号变化率和长时段信号谱平坦度)的语音端点检测方法相比,所提方法在不同噪声环境及信噪比下,均具有更高的检测准确率,尤其在非平稳噪声条件下的检测效果提升明显,例如在机枪噪声环境下,平均检测准确率提高超过10%。 相似文献
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基于管内声波的输气管道泄漏诊断方法研究 总被引:1,自引:0,他引:1
输气管道发生泄漏后如果没有及时发现,将可能造成巨大的生命财产损失及环境污染,因此研究输气管道泄漏监测技术具有非常重要的意义.本文研究基于声波传感器的输气管道泄漏检测和定位问题,首先利用短时傅里叶变换方法找到泄漏声信号的频率特征,然后通过分析某个频段内的信号幅值来判断管道是否发生泄漏.在检测到泄漏后,利用FIR滤波器对特征频段内的声信号进行滤波,最后通过对信号包络的分析实现对泄漏的定位.基于实际管线历史数据的离线实验表明了该方法的有效性. 相似文献
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基于输气管线的物理模型,结合负压波幅值沿管线近似指数衰减的机理提出了一种用于评估输气管线泄漏监测与定位系统性能的指标--最小可检测泄漏量的方法,同时也推导出了输气管线敏感点的数学表达式.通过实际数据仿真分析了管线的负压波衰减因数、泄漏点、仪器精度与噪声等对最小可检测泄漏量与敏感点的影响,其结果为泄漏检测与定位系统的性能指标,如灵敏度、评估能力等给出了理论指导,使得以前只能定性分析的问题,可以定量进行研究. 相似文献
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张涛 《计算机测量与控制》2015,23(1):86-89
为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值. 相似文献
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In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times. 相似文献
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《Information & Management》2016,53(6):787-802
Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice. 相似文献
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Recent years have seen rapid advances in various grid-related technologies, middleware, and applications. The GCC conference has become one of the largest scientific events worldwide in grid and cooperative computing. The 6th international conference on grid and cooperative computing (GCC2007) Sponsored by China Computer Federation (CCF),Institute of Computing Technology, Chinese Academy of Sciences (ICT) and Xinjiang University ,and in Cooperation with IEEE Computer Soceity ,is to be held from August 16 to 18, 2007 in Urumchi, Xinjiang, China. 相似文献
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Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs. 相似文献
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Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel. 相似文献
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《浙江大学学报:C卷英文版》2014,(11)
正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and 相似文献
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Zhao-hui WU 《浙江大学学报:C卷英文版》2014,(10)
正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control 相似文献
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《浙江大学学报:C卷英文版》2014,(10)
正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate 相似文献