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1.
故障综合诊断技术一直是复杂机载电子系统研发过程中的关键部分,当前的故障诊断技术同时需要机内测试(BIT)和场外自动化测试设备(ATE)的测试结果才能得出诊断结果,诊断效率低,时间长并且不能在线诊断。针对新一代战斗机将更加依赖航空电子系统的趋势,迫切需要一种诊断时间短,且能够实现在线诊断的故障诊断技术。因此,一种基于模型的故障诊断方法被提出。该方法通过融合多信号模型和整数编码故障字典模型,模块间采用多信号模型,单个模块中采用整数编码故障字典模型,克服了多信号模型对测试信息的浪费和整数编码故障字典模型建模困难的缺点,并提出一种多目标测试优选方法,通过优化检测方案,充分发挥BIT的检测性能。该方法通过充分使用BIT的测试信息,摆脱了对场外ATE的依赖,实现了在线快速定位故障并识别故障模式。 相似文献
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Xiao Wang Qihua Zhu Yanlei Zuo Fang Wang Donghui Lin Zheng Huang Xiaofeng Wei 《中国光学快报(英文版)》2008,6(4)
Design and operation of a practical, accurate alignment diagnostic system is important for the grating tiling technology, which is supposed to be applied in a chirped-pulse amplification system to increase the output power. A diagnostic method is proposed and demonstrated for grating tiling. Provided that the wavelength and incident angle of the diagnostic beam are properly set, the far-field of the main laser beam and that of the diagnostic beam can vary in the same way with the tiling errors between the sub-aperture gratings. Therefore, rotational and translational errors can be controlled and compensated according to the far-field of the diagnostic beam. The real-time monitoring and alignment can be achieved without disturbing the main beam. 相似文献
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神光Ⅲ主机通用诊断搭载平台提供各种诊断系统送进和收回的搭载功能,便于诊断系统的拆装和维护保养,同时提供精确的径向、指向瞄准能力,能将诊断系统送至靶室内指定位置,并且能在不破坏靶室真空的状态下安装、调试和维护诊断系统。将通用诊断搭载平台安装在神光Ⅲ原型装置上进行精度检测,得到其真空状态下的径向、X和Y方向指向定位精度分别为36,13,8 μm,全行程的径向复位精度、X和Y方向指向复位精度分别达到20,30,12 μm。搭载分幅相机诊断包进行激光打靶考核,实验结果表明:其指向瞄准精度、真空性能、接口等均满足使用要求,并具备了对抗强电磁干扰与辐射的能力。 相似文献
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Johannes T. Heverhagen Andreas Zielke Natascha Ishaque Thomas Bohrer Michael El-Sheik Klaus-Jochen Klose 《Magnetic resonance imaging》2001,19(10):1275-1277
The incidence of acute colonic diverticulitis (ACD) is increasing. To allow rational therapeutic decisions to be made, a timely diagnosis is required. The feasibility of “on-admission-MRI” to establish the diagnosis has not yet been studied. Therefore, a prospective observational study was carried out in 20 patients with an established diagnosis of ACD. The diagnostic criteria for the MRI diagnosis of ACD were the demonstration of at least one diverticulum, pericolic exudation, and edema of the colonic wall. MRI was diagnostic in all but one patient. It is concluded that MRI has considerable diagnostic potential in ACD and should be formally evaluated. 相似文献
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Christopher J. Stein 《Molecular physics》2017,115(17-18):2110-2119
ABSTRACTOne of the most critical tasks at the very beginning of a quantum chemical investigation is the choice of either a multi- or single-configurational method. Naturally, many proposals exist to define a suitable diagnostic of the multi-configurational character for various types of wave functions in order to assist this crucial decision. Here, we present a new orbital-entanglement-based multi-configurational diagnostic termed Zs(1). The correspondence of orbital entanglement and static (or non-dynamic) electron correlation permits the definition of such a diagnostic. We chose our diagnostic to meet important requirements such as well-defined limits for pure single-configurational and multi-configurational wave functions. The Zs(1) diagnostic can be evaluated from a partially converged, but qualitatively correct, and therefore inexpensive density matrix renormalisation group wave function as in our recently presented automated active orbital selection protocol. Its robustness and the fact that it can be evaluated at low cost make this diagnostic a practical tool for routine applications. 相似文献
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测试和诊断的融合可以提高武器系统的维护效率,但是随着武器装备的升级改造就带来了原有的诊断知识难共享、诊断推理软件难以互操作、难重用,诊断功能难扩展的问题;AI-ESTATE标准规范了诊断知识和数据的标准化描述和诊断推理机的服务接口,为知识互换和软件可移植提供了条件;论文研究了面向服务的AI-ESTATE开放式故障诊断系统的体系结构和信息传递模式,分析了推理机模型管理服务和互操作服务;然后运用静态诊断模型服务关系图和UML时序图分析了AI-ESTATE服务在诊断模型编辑、索引等功能实现中的交换流程,运用动态诊断模型的UML时序图分析了AI-ESTATE互操作服务在故障诊断系统运行中推理机与其它组件的动态交互过程,为开放式AI-ESTATE智能诊断系统的开发奠定了基础。 相似文献
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Statefinder diagnostic is a useful method which can differ one dark energy model from each others. In this Letter, we apply this method to a holographic dark energy model from Ricci scalar curvature, called the Ricci dark energy model (RDE). We plot the evolutionary trajectories of this model in the statefinder parameter-planes, and it is found that the parameter of this model plays a significant role from the statefinder viewpoint. In a very special case, the statefinder diagnostic fails to discriminate LCDM and RDE models, thus we apply a new diagnostic called the Om diagnostic proposed recently to this model in this case in Appendix A and it works well. 相似文献
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为了验证国产质子注入器的参数是否满足需求,注入器团队设计了束流测量系统用于测量国产质子直线注入器束流的流强、发射度、能量以及能散等关键指标。此测量系统包含了采用变聚焦法测量发散度、采用分析磁铁测量束流能量和能散的主要功能。利用束流输运线设计软件Tracewin(版本2.11.4.1)进行了系统束线的物理设计,对束测系统测量质子束流的发散度和能量的精度进行了模拟计算。由于经过RFQ-(APF)DTL加速后的粒子束团为“拖尾”的非理想粒子束团,需要针对非理想束团对束测系统测量发射度和能量产生的影响进行分析。通过对模拟计算结果的分析,发现相对于测量理想粒子束团的结果非理想粒子束团对束测系统测量发射度精度影响较大;非理想粒子束团对束测系统测量能量精度影响较小。 相似文献
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通过封装服务、规范标准服务,AI-EATATE为诊断系统的客户端和应用对象的扩展、测试与诊断的分离提供了条件,使其更适合远程控制的诊断系统的构建。论文分析了武器装备远程故障诊断对知识重用与共享、软件互操作的需求,提出了面向远程诊断的AI-ESTTAE智能诊断系统构建的方法;研究了AI-ESTATE智能诊断系统的基本结构和框架,讨论了AI-ESTATE在发展过程中其服务的变化对开放、远程智能诊断系统构建的影响;最新的AI-ESTATE标准规范的服务更加强了对诊断过程的控制和效果评估,论文采用状态图的方式分析了最新的AI-ESTTAE服务在远程故障诊断过程的作用,为符合AI-ESTATE标准的远程故障诊断系统的开发提供了方法。 相似文献
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结合多变量统计分析肝癌氧合血红蛋白表面增强拉曼光谱 总被引:2,自引:0,他引:2
采用二维纳米结构银膜作为基底,检测了30例肝癌患者和30例健康人氧合血红蛋白表面增强拉曼散射(SERS)谱。利用主成分分析(PCA)结合独立变量t检验建立SERS光谱诊断多元统计算法模型,并用判别分析方法对此统计算法的诊断效果进行评价。实验结果表明,肝癌患者与健康人氧合血红蛋白SERS光谱有明显区别。采用PCA分析结合独立变量t检验统计分析方法得出SERS光谱PCA得分三维散点图可以很好的区分健康人和肝癌患者。利用判别分析方法得出该统计算法诊断肝癌的特异性和灵敏度分别为90%和96.7%,总判别正确率为93.3%。与健康人相比,肝癌患者氧合血红蛋白中吡咯环的呼吸振动模式的数量、酪氨酸和苯丙氨酸的含量相对偏低。研究结果表明,氧合血红蛋白SERS光谱统计分析有望发展成为一种新型的肝癌诊断工具。 相似文献
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The present paper contributes to the development of new efficient solutions aimed at improving vehicle functional safety through the implementation of new transmission diagnostic methods. The study focuses on a new perspective of the diagnostic frequency range for hypoid gear condition monitoring, using acoustic emission and vibro-acoustic signal measurements and the Discrete Wavelet Transform for data analysis. The identification of the most sensitive diagnostic parameters and determination of frequency intervals using the Discrete Wavelet Transform, in which the most significant increase in the values of diagnostic parameters can be seen, has been presented. In addition, the identification of the sensitivity of the above-introduced non-destructive methods is presented. Diagnostic results in the extended frequency range were compared with the results of the classical method, and it was found that the selected parameter in the proposed measuring range could better characterize the condition of the gear unit. 相似文献
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Lewin PA 《Ultrasonics》2004,42(1-9):1-7
The last three decades of development in diagnostic ultrasound imaging and technology are briefly reviewed and the impact of the crucial link between the two apparently independent research efforts, which eventually facilitated implementation of harmonic imaging modality is explored. These two efforts included the experiments with piezoelectric PVDF polymer material and studies of the interaction between ultrasound energy and biological tissue. Harmonic imaging and its subsequent improvements revolutionized the diagnostic power of clinical ultrasound and brought along images of unparalleled resolution, close to that of magnetic resonance imaging (MRI) quality. The nonlinear propagation effects and their implications for both diagnostic and therapeutic applications of ultrasound are also briefly addressed. In diagnostic applications, the impact of these effects on image resolution and tissue characterization is reviewed; in therapeutic applications, the influence of nonlinear propagation effects on highly localized tissue ablation and cauterization is examined. Next, the most likely developments and future trends in clinical ultrasound technology, including 3D and 4D imaging, distant palpation, image enhancement using contrast agents, monitoring, and merger of diagnostic and therapeutic applications by e.g. introducing ultrasonically controlled targeted drug delivery are reviewed. Finally, a possible competition from other imaging modalities is discussed. 相似文献
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M. T. Alexandrov O. G. Gaponenko M. A. Ivanova V. A. Khomenko G. P. Kuzmin M. V. Makarova E. P. Pashkov G. M. Sorokoumova E. N. Vasiliev 《Laser Physics》2007,17(12):1416-1423
The laser-induced fluorescence spectra of five types of mycobacteria are studied in various associations. The results obtained are used to demonstrate the possibility of a diagnostic system for the differential diagnostics of microbial diseases. The method employed for the specific analysis of microbial species in the substrate that contain various associations is based on a regression of the spectral characteristics of the fluorescence intensity to the principal components. The diagnostic efficiency is increased when the fluorescence spectra are reconstructed with regard to the optical characteristics of the medium. The detergent effect on the parameters of microbial fluorescence diagnostics is studied. 相似文献
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V. L. Frolov G. N. Boiko S. A. Metelev E. N. Sergeev 《Radiophysics and Quantum Electronics》1994,37(7):593-603
Results of measurements of the characteristics of stimulated electromagnetic emission induced in ionospheric plasma by pulsed high-power radio waves (diagnostic emission) presented. The dependences of the properties of diagnostic emission on the parameters of the diagnostic wave, ionospheric conditions, and the level of development of artificial ionospheric turbulence are determined, and criteria are given for selection of optimal diagnostic conditions for ionospheric-plasma sounding. Results of experiments on the sounding of artificial ionospheric turbulence by means of diagnostic emission are provided. It is established that with transition from daytime to evening conditions, the characteristic times of emission decay are sharply increased. This is attributed to an increase in the natural perturbation of the F-region.Scientific-Research Radio-Physics Institute, Nizhny Novgord. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 37, No. 7, pp. 909–928, July, 1994. 相似文献
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Ramis Örlü Antonio Segalini Joseph Klewicki P. Henrik Alfredsson 《Journal of Turbulence》2016,17(7):664-677
The diagnostic scaling concept, introduced for the streamwise turbulence intensity in wall-bounded turbulent flows (Alfredsson, Segalini and Örlü, Phys. Fluids 2011;23:041702), is here extended and generalised not only for the higher even-order central statistical moments, but also for the odd moments and thereby the probability density distribution of the streamwise velocity fluctuations. Turbulent boundary layer data up to a friction Reynolds number of 60,000 are employed and demonstrate the feasibility of the diagnostic scaling for the data throughout the logarithmic and wake regions. A comparison with the generalised logarithmic law for even-order moments by Meneveau and Marusic (J. Fluid Mech. 2013;719:R1) based on the attached-eddy hypothesis, is reported. The diagnostic plot provides an apparent Reynolds-number-independent scaling of the data, and is exploited to reveal the functional dependencies of the constants needed in the attached-eddy-based model. In particular, the invariance of the lowest order diagnostic scaling poses an intriguing incompatibility with the asymptotic constancy of the Townsend–Perry constant. 相似文献