一种从状态信息中自动提取特征知识的智能方法

为了建立基于知识的发动机故障诊断系统(KBSED),本文提出了一种从状态信息中自动提取特征知识的智能方法。该方法是基于波形的符号表达及波形局部畸变特征的谓词描述来实现的。文中还结合汽车发动机点火波形讨论了基于深知识的波形分类规则的自动获取问题。     

某兵器波形参数自动测量若干问题研究

本文分析了某兵器波形参数的特点，研究了对其进行自动测量的原理，讨论了一种能对波形参数实现自动测量的硬件，软件构成方法。     

血栓多普勒信号的多参数提取及分类

血栓的准确检测可以用于早期脑血管疾病的诊断，超声多普勒是一种无损的血栓检测技术。文章使用三种信号处理方法：传统的声谱分析法、小波分析法、renyi信息量分析法对血栓多普勒信号进行分析，提取出相应的特征参数，然后对敏感的特征参数采用反向传输(Back-Propagation，简称BP)神经网络进行分类，建立起血栓、干扰噪声和正常血流信号的自动判别系统。通过对300例仿真多普勒信号和163例临床采集的大脑中动脉多普勒信号进行分析，结果表明：本文建立的系统对血栓的检测率高于传统的方法，有望可用于血栓多普勒信号的自动检测。     

便携式脐血流多普勒信号多参数分析系统

文章在笔记本计算机的硬件基础上建立了脐血流多普勒信号多参数分析的便携式系统。通过计算机声卡采集脐血流音频多普勒信号，然后进行传统的声谱参数分析、零极点模型分析、Teager算子分析和分形特征分析，应用Fisher多元判据法对四类特征参数进行分类决策，从而判断胎儿的生长情况。流速实验和临床试用的结果表明，该系统是有效的，可以应用于产科的临床诊断。     

改进的波形复杂度算法在核爆炸监测中的应用

验证了传统的波形复杂度对于核爆地震信号分类的有效性。提出了两种时域改进算法,使识别率有了小幅度的提高。将传统的时域波形复杂度推广到时频联合域,提出了一种基于短时傅立叶变换的波形复杂度计算框架。在对所提算法框架进行简化处理后,借助于Fisher线性判别分析方法实现了地震波信号的特征提取。分类实验结果表明所提方法的分类性能优于现有的波形复杂度的分类性能。     

条码技术与成组技术结合应用于计算机辅助估价和工艺设计

本文介绍了用条形码检索方法，对电站配件自动进行估价和生产工艺卡的一种计算机软件系统。该系统依据电力行业标准《电站设备备品配件分类与编码导则》，对电站配件自动分类编码，并实现字符码与条形码的自动转换，只需扫描条形码，即可对相应配件作出估价，并生成其工艺过程卡。     

小波分析应用于负载类型及用电大小的识别

文章对计算机智能集中供电系统的负载波形进行了小波变换分层分析,利用其各层系数及能量比值,对冲击性整流负载和一般电力负载电流波形进行分类,用计算机自动区分负载类型.     

一种多普勒宽容的多址波形

提出了一种具有多址特性、对多普勒宽容的主动波形．HFM-Costas波形。这种波形是通过将宽带双曲调频波形在时间上切分为子脉冲,再根据Costas阵列编码重新排列而成．它结合了Costas编码的多址特性和双曲调频信号的多普勒宽容性。这种波形适于采用相干．非相干混合接收机进行处理,接收机结构简单,计算量小,检测鲁棒性好。详细说明了这种波形的生成方法、相应混合接收机结构,并分析了该波形的主要特性。最后．通过湖上试验进行了验证。     

复杂波形的事件分解合成及定位方法

针对复杂信号波形的分析与校准,提出了一种以波形事件为核心的复杂信号波形分解与合成方法。首先将波形事件分类成周期性事件和非周期性事件。对于周期性事件,按照事件幅度由高到低依次分解,化繁为简,降低复杂波形分析的复杂程度和技术难度。周期性事件分解完毕后剩余部分,属于非周期性事件,包括单次事件和随机事件。经过按事件进行复杂波形分解,可以获得各个事件在复杂波形上的准确定位,以及实现各个事件与母体波形的有效分离。在一组以受干扰的正弦波为基础的复杂信号波形上所进行的实验及分析,验证了所述方法的有效性与可行性。     

一种用于几何造型的一维布尔运算新算法

几何造型中，往往要进行线段与面、线段与体的分类，分类后用布尔算子合成。本文用自动机理论对合成过程进行了研究，结果给出了一种新的一维布尔运算算法。用有限状态自动机实现的该算法可用于线─—面分类及线─—体分类后的合成。     

Supporting design via the System Operational Dependency Analysis methodology

In this paper, we introduce the system operational dependency analysis methodology. Its purpose is to assess the effect of dependencies between components in a monolithic complex system, or between systems in a system-of-systems, and to support design decision making. We propose a parametric model of the behavior of the system. This approach results in a simple, intuitive model, whose parameters give a direct insight into the causes of observed, and possibly emergent, behavior. Using the proposed method, designers, and decision makers can quickly analyze and explore the behavior of complex systems and evaluate different architecture under various working conditions. Thus, the system operational dependency analysis method supports educated decision making both in the design and in the update process of systems architecture, without the need to execute extensive simulations. In particular, in the phase of concept generation and selection, the information given by the method can be used to identify promising architectures to be further tested and improved, while discarding architectures that do not show the required level of global features. Application of the proposed method to a small example is used to demonstrate both the validation of the parametric model, and the capabilities of the method for system analysis, design and architecture.     

Ultrafast compound Doppler imaging: providing full blood flow characterization

Doppler-based flow analysis methods require acquisition of ultrasound data at high spatio-temporal sampling rates. These rates represent a major technical challenge for ultrasound systems because a compromise between spatial and temporal resolution must be made in conventional approaches. Consequently, ultrasound scanners can either provide full quantitative Doppler information on a limited sample volume (spectral Doppler), or averaged Doppler velocity and/or power estimation on a large region of interest (Doppler flow imaging). In this work, we investigate a different strategy for acquiring Doppler information that can overcome the limitations of the existing Doppler modes by significantly reducing the required acquisition time. This technique is called ultrafast compound Doppler imaging and is based on the following concept: instead of successively insonifying the medium with focused beams, several tilted plane waves are sent into the medium and the backscattered signals are coherently summed to produce high-resolution ultrasound images. We demonstrate that this strategy allows reduction of the acquisition time by a factor of up to of 16 while keeping the same Doppler performance. Depending on the application, different directions to increase performance of Doppler analysis are proposed and the improvement is quantified: the ultrafast compound Doppler method allows faster acquisition frame rates for high-velocity flow imaging, or very high sensitivity for low-flow applications. Full quantitative Doppler flow analysis can be performed on a large region of interest, leading to much more information and improved functionality for the physician. By leveraging the recent emergence of ultrafast parallel beamforming systems, this paper demonstrates that breakthrough performances in flow analysis can be reached using this concept of ultrafast compound Doppler.     

模糊类知识隶属函数的管理及其软件开发

隶属函数是模糊集合理论及其应用的基本而关键的问题。本文对隶属函数这一类模糊知识进行了分析,把隶属函数作为一条针对论域X、相对参考目标Y、在某模糊等级A上、由一系列座标点连接而成的平面曲线来处理。设计和开发了隶属函数的管理软件,并以控件形式与其他模糊系统集成。详细介绍了隶属函数控件的属性和触发方法,隶属函数管理器的设计和开发,为各领域模糊分析和决策系统的开发提供了重要的工具,既有利于对已有经验知识的积累和重复使用,也可使各项模糊评价、分析或决策工作具有同一个经验基准。     

An integrated probabilistic risk analysis decision support methodology for systems with multiple state variables

Probabilistic risk analysis (PRA) methods have been proven to be valuable in risk and reliability analysis. However, a weak link seems to exist between methods for analysing risks and those for making rational decisions. The integrated decision support system (IDSS) methodology presented in this paper attempts to address this issue in a practical manner. In consists of three phases: a PRA phase, a risk sensitivity analysis (SA) phase and an optimisation phase, which are implemented through an integrated computer software system. In the risk analysis phase the problem is analysed by the Boolean representation method (BRM), a PRA method that can deal with systems with multiple state variables and feedback loops. In the second phase the results obtained from the BRM are utilised directly to perform importance and risk SA. In the third phase, the problem is formulated as a multiple objective decision making problem in the form of multiple objective reliability optimisation. An industrial example is included. The resultant solutions of a five objective reliability optimisation are presented, on the basis of which rational decision making can be explored.     

基于Radon变换的速变谱提取算法

多普勒频移随时间快速变化这一信息在水听器探测空中高速目标时具有重要意义,提出了速变谱的概念,并提出应用Radon变换在信号的LOFAR图中捕捉速变谱信息;针对速变谱曲线可能是任意曲线而Radon变换只能对直线等已知参数方程的曲线进行提取的问题,提出分块Radon变换的方法。仿真与海试数据分析均表明,该方法可以在较低信噪比情况下检测到速变谱信息。     

An evaluation system of the setting up of predictive maintenance programmes

Predictive Maintenance can provide an increase in safety, quality and availability in industrial plants. However, the setting up of a Predictive Maintenance Programme is a strategic decision that until now has lacked analysis of questions related to its setting up, management and control. In this paper, an evaluation system is proposed that carries out the decision making in relation to the feasibility of the setting up. The evaluation system uses a combination of tools belonging to operational research such as: Analytic Hierarchy Process, decision rules and Bayesian tools. This system is a help tool available to the managers of Predictive Maintenance Programmes which can both increase the number of Predictive Maintenance Programmes set up and avoid the failure of these programmes. The Evaluation System has been tested in a petrochemical plant and in a food industry.     

彩色多普勒超声检测左肾静脉受压综合症患儿精索静脉曲张

探讨左肾静脉受压综合症的患儿精索静脉曲张发生率及其程度。应用彩色多普勒超声检测42例已诊断为左肾静脉受压综合症的男性患儿其不同体位时左右精索静脉的内径变化，并与左肾静脉扩张段内径（A）和受压段内径（B）比值、扩张段流速（Va）和受压段流速（Vb）比值进行比较。结果：42例患儿中平卧位和站立位无1例伴发右侧精索静脉曲张；平卧位时患儿临床型左侧精索静脉曲张占5％，亚临床型左侧精索静脉曲张占12％；站立位时临床型左侧精索静脉曲张达7％，亚临床型达21％，且随A／B比值、Va/Vb比值的增大而增加。可见左肾静脉受压时可伴发左侧精索静脉曲张，平卧位发生率为19％，站立位为28％。彩色多普勒超声是其首选的检查方法。     

Vibration analysis of piezoelectric materials by optical methods

This study provides two noncontact and realtime optical measurement methods to assess the displacement, natural frequencies, and mode shapes of a vibrating piezoelectric material. The methods are carried out using amplitude-fluctuation electronic speckle pattern interferometry (AF-ESPI) and laser Doppler vibrometer (LDV), which are full-field and point-wise displacement measurement, respectively. Because the fringe patterns measured by AF-ESPI appear as a clear picture at the natural frequency, both natural frequencies and mode shapes of the vibrating material can be successfully obtained. In the LDV system, a swept-sine excitation signal from the function generator to the beam can result in a corresponding peak in frequency response curve at natural frequencies. From the frequency response curve, the natural frequencies are thus acquired. Measured results by both methods are seen to be in good agreement with theoretical predictions by the Galerkin method and finite element method.     

Prospect Theory Based Hesitant Fuzzy Multi-Criteria Decision Making for Low Sulphur Fuel of Maritime Transportation

The environmental impact of maritime transport has now become a relevant issue in sustainable policy formulation and has attracted increasing interest from academia. For the sustainable development of maritime transport, International Maritime Organization stipulates that the sulfur content of ship emissions will reach 0.5 from 2020. With the approaching of the stipulated implementation date, shipowners need to adopt scientific methods to make decision on low sulfur fuel. In this study, we applied a prospect theory based hesitant fuzzy multi-criteria decision-making model to obtain the optimal decision of low Sulphur marine fuel. For this purpose, the hesitant fuzzy decision matrix is established to collect expert opinions, the maximizing deviation method is adopted to determine criteria weights. According to calculate the Euclidean distance from the reference points, we obtain the comprehensive prospect values of alternatives. Lastly, a case study is carried out to illustrate the significance and effectiveness of the proposed methodology. The innovation of this study is that it is the first-time adopting prospect theory and hesitate fuzzy sets to multi-criteria decision making for low Sulphur marine fuel, which provides an effective decision model for shipping companies under Low Sulphur regulations, and can also be extended to other industries.