查询词典 spectrum analysis

Aiming at the signal processing problems that exist in online fault diagnosis for train running gear, based on discussing the principle of characteristic spectrum analysis, a method of full period and uniform angle sampling is applied, which transfers the vibration signal from time domain into angular domain. The angular domain signal is transferred into corresponding characteristic spectrum using FFT. Through spectrum estimation and analysis, fault characteristic spectrum values of running gear components are acquired to distinguish their faults.

在讨论特征分析方法原理的基础上，针对机车走行部故障在线监测过程中存在的信号分析与处理问题，运用整周期等角度采样方法将时域振动信号转换为角域信号，采用FFT变换将角域信号变换为对应的特征频谱，通过谱估计、谱图分析得到机车走行部各零部件的故障特征谱值，再根据该特征谱值识别机车走行部各零部件的故障。

Analyzed essential structure of spectrum analysis system of international, designed VUV excitation with 30W deuterium lamp and emission spectrum analysis system.

分析了国内外PDP荧光粉光谱分析系统的基本结构，设计了以30W氘灯为激发光源的真空紫外激发／发射光谱分析系统。

The IR spectrum analysis results of the level of humification are consistent with those obtained from ultra-violet spectrum analysis.

其中，缙云山腐殖土腐殖酸的E465/E665最大，说明其分子的腐殖化程度、芳构化度和分子复杂程度等最小。

The spectrum analysis of the air-ultrasonic waveform indicates that when the matcher thickness is calculated at the highest spectrum and the subsequent higher spectrum of the pulse waveform, it can obtain a better result. But all the highest spectrum of the air-ultrasonic waveform moves to the high frequency zone in the experiment, which is a possible important reason that the testing extent of the air-ultrasonic transducer is limited.

经对空气超声波形进行频谱分析后发现用脉冲波形的最高谱线及次高潜线对应的频率计算匹配层厚度，可得到较好的匹配结果，但是空气超声波形的最高谱线均移向高频段，这可能是造成脉冲空气超声换能器可检测的范围有限的一个重要原因。

The spectrum analysis of periodic signals has some difference with the spectrum analysis of nonperiodic signals.The DFT result of nonperiodic signals indicates the spectrum density on frequency Ω,and is continuous.

一般信号的DFT结果表示该信号在频率Ω处的频谱密度，它是一个连续信号，周期信号的DFT仅表示它的基波及各次谐波的幅值，是一个离散信号。

The holistic design of the system and resolved the designs of software and hardware based on VXI bus are put forward according to the demand of test system. The hardware and software is designed, including the formation and design of hardware system, visual instrument software architecture, program design for instrument driver, high speed real-time data collection. In the dynamic test program, the idea of"software is instrument"was applied to meet the diverse test demands. Last, it is proposed that the VXI test system be developed to more totalization and networked. The basic theory of system identification was introduced briefly at first. The principle of spectrum analysis system identification based on Wiener-Hopf equation was expatiated. and the questions in applying Peusdo Random signal as spectrum analysis methods stimulate signal was studied, The generation principle of the peusdo random signal is researched, the characteristic of peusdo random are analyzed from time domain and frequency domain, the inverse repeat peusdo random signal is brought forward to make up the shortage of ordinary peusdo random signal. And a new chaos genetic algorithmis presented to solve the unprecise problem of the traditional method. In the servo valve dynamic characteristic test system, the spectrum analysis methods was applied successfully, the servo valve dynamic characteristic could be acquired rapidly and exactly, the test results were analyzed and the ameliorate methods were brought forward at last.

结合航天某集团液压测试中心测试系统的需求，提出了基于VXI总线的液压测试系统的整体设计方案，完成了测试系统的硬件设计与软件设计，包括硬件系统构成与设计、虚拟仪器软件结构、仪器驱动程序设计、高速同步实时数据采集等内容；以伺服阀动态特性测试为例设计了测试模块，该模块体现了VXI总线仪器软件开发所倡导的"虚拟仪器"的思想，以软件的灵活应用满足了不同的测试需求；结合自动测试系统的发展，研究了VXI测试系统与网络技术结合，实现各种软硬件资源共享，进一步提高设备及数据的利用率和系统的扩展性，使自动测试向综合化、网络化方向发展；研究了伪随机信号作为谱分析法辨识的激励信号时存在的问题，讨论了伪随机信号的产生机理，从频域和时域分析了伪随机信号的性质及其应用，提出了用逆重复伪随机信号弥补了普通伪随机信号的不足，并以混沌遗传算法对逆重复伪随机信号产生过程中的参数进行优化，可以更合理而不是凭经验产生需要的逆重复伪随机信号。

The EMG signal was recorded simultaneously from brachioradialis, biceps, deltoid and trapezius then analyzed with amplitude, spectrum or combined indices called the joint analysis of EMG spectrum and amplitude.

同时遥测记录肱桡肌、肱二头肌、三角肌、斜方肌的表面肌电信号，采用时域、频域及肌电术振幅频谱联合分析方法（the joint analysis of EMG spectrum and amplitude，JASA）的指标进行分析。

The holistic design of the system and resolved the designs of software and hardware based on VXI bus are put forward according to the demand of test system. The hardware and software is designed, including the formation and design of hardware system, visual instrument software architecture, program design for instrument driver, high speed real-time data collection. In the dynamic test program, the idea of"software is instrument"was applied to meet the diverse test demands. Last, it is proposed that the VXI test system be developed to more totalization and networked. The basic theory of system identification was introduced briefly at first. The principle of spectrum analysis system identification based on Wiener-Hopf equation was expatiated. and the questions in applying Peusdo Random signal as spectrum analysis methods stimulate signal was studied, The generation principle of the peusdo random signal is researched, the characteristic of peusdo random are analyzed from time domain and frequency domain, the inverse repeat peusdo random signal is brought forward to make up the shortage of ordinary peusdo random signal. And a new chaos genetic algorithmis presented to solve the unprecise problem of the traditional method. In the servo valve dynamic characteristic test system, the spectrum analysis methods was applied successfully, the servo valve dynamic characteristic could be acquired rapidly and exactly, the test results were analyzed and the ameliorate methods were brought forward at last.

结合航天某集团液压测试中心测试系统的需求，提出了基于VXI总线的液压测试系统的整体设计方案，完成了测试系统的硬件设计与软件设计，包括硬件系统构成与设计、虚拟仪器软件结构、仪器驱动程序设计、高速同步实时数据采集等内容；以伺服阀动态特性测试为例设计了测试模块，该模块体现了VXI总线仪器软件开发所倡导的&虚拟仪器&的思想，以软件的灵活应用满足了不同的测试需求；结合自动测试系统的发展，研究了VXI测试系统与网络技术结合，实现各种软硬件资源共享，进一步提高设备及数据的利用率和系统的扩展性，使自动测试向综合化、网络化方向发展；研究了伪随机信号作为谱分析法辨识的激励信号时存在的问题，讨论了伪随机信号的产生机理，从频域和时域分析了伪随机信号的性质及其应用，提出了用逆重复伪随机信号弥补了普通伪随机信号的不足，并以混沌遗传算法对逆重复伪随机信号产生过程中的参数进行优化，可以更合理而不是凭经验产生需要的逆重复伪随机信号。

Through simulation and computation, some critical values to contral interferences are obtained. These values have directive significance to the design and deployment of WRAN.(4) New methods to measure and analyze spectrum aredevelopedAccording to the shortages of previous spectrum measurements, new methods to measure spectrum occupancy in wide-band and multi-point synchronously is proposed in this dissertation, and the tests last a whole week; the relativities of licensed services are considered when test points are selected. More importantly, data mining and in-depth analysis are carried out with the huge amounts of test data, and a channel analysis method using Channel Vacancy Duration and Service Congestion Rate are proposed. The spectrum relativities of 3-dimension in time, space and frequency are researched also. The correlativity between channel state and history information is discoved, and which will provide the scientific basis to channel modeling, spectrum analysis and decision of CR users.

4提出了频谱测量与分析的新方法针对以前频谱测量工作存在的不足，本文提出了多点同时广域频谱测量方法，测量工作持续了一周的时间，同时考虑了测量地点的选取和频谱授权业务之间的相关性；对测量得到的海量数据进行了数据挖掘和深度分析，提出了使用信道空闲时间(Channel VacancyDuration，CVD)和业务拥塞率(Service Congestion Rate，SCR)进行信道分析的方法，研究了频谱之间的时间、空间、和频率三维立体的相关性，发现了信道状态和历史信息的关联性，为CR用户的信道建模、频谱分析和决策提供了科学的理论依据。

In view of that spectrum quantitative analysis of component concentration,and qualitative analysis of component recognition can not be carried out using the same model simultaneously during infrared spectrum analysis of the mixed gas,a method of mixed gas component infrared spectrum recognition based on SVM regression model is proposed.

针对混合气体红外光谱分析中无法采用同一模型同时进行混合气体组分浓度的定量分析和组分种类的定性分析的问题，本文提出了基于SVM回归模型的混合气体组分种类光谱识别方法。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。