查询词典 frequency analysis

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。

A Wavelet analysis is far superior to Fourier analysis in drawing out the signal features. Wavelet analysis has the characteristic of spatial locality, and the window wideness of the time and the frequency both can be adjusted, so it can analyze the details of a signal.

a 小波分析在信号的特征提取方面具有传统Fourier 分析无可比拟的优越性，小波分析在时频域都具有表征信号局部特征的能力，能够聚焦到信号的细节。

Due to the complexity of the cell jitter, the NonSynchronous Tining Recovery methods are currently not mature With the emphasis being given to the Class A CBR traffic, this paper analyzes the performance of the queueing delay and cell jitter at the source node and intermediate nodes, and discusses the Source Timing Recovery at the destination node in ATM networks Firstly, this paper presents a description of the cell jitter of CBR traffic, and gives the definitions of two kinds of cell jitter regarding the Source Timing Recovery for CBR traffic Then, by using exact mathematical models and analysis methods, this paper analyzes the impact of the factors, such as the capacity of the queueing buffer, the randomness, the deterministic nature and the correlation in cell arrivals of the background traffic sources, on the queueing delay and cell jitter performance of the CBR traffic through Statistical Multiplexitng To obtain an insight into the power spectral distribution and look for better schemes for the depression and filtering of the cell jitter, within the analyses we succeed deriving the power spectrum of the cell jitter for CBR traffic Hence, not only the power spectral distribution of the cell jitter can in the frequency domain be qualitatively understood, but also can the rms (root-meansquare) value of the cell jitter be quantitatively obtained so as to more accurately measure the amplitude of the jitter In the end-to-end performance analysis of the queueing delay and cell jitter, we propose a kind of quasi-periodic cell stream model to characterize the jittered CBR traffic, and present an initial queueing analysis of the CBR traffic following such a model at a generic intermediate node Additionally, we briefly discuss the buildout/playout and Source Timing Recovery functions of the destination node Finally, regarding the Source Timing Recovery of CBR traffic, this paper systematically discusses several important principles of the cell jitter filtering and depression reported in the literature, introduces several implementation schemes of the Source Timing Recovery e.

由于信元抖动的复杂性，非同步定时恢复方法目前还很不成熟。本文针对A类CBR业务流在ATM网络源节点和中间节点的排队时延和信元抖动性能，以及在目的节点的源定时恢复问题作了较为全面的研究。首先，文中描述了CBR业务流的信元抖动，并具体地给出了两种与CBR业务源定时恢复有关的信元抖动的定义。然后，采用了精确的数学模型和分析方法，有针对性地分析了业务背景中信元到达的纯随机性、确定性和相关性以及排队缓存器容量等因素对CBR业务流经过统计复用后的排队时延和信元抖动性能的影响。为了了解信元抖动的功率频谱分布和寻求更好的抑制和滤除抖动的方法，在性能分析中，我们成功地完成了CBR业务流信元抖动的功率谱分析，使得不但可以从频域定性地认识信元抖动的能量分布特性，而且还可以定量地求出信元抖动的均方根值(rms：root-mean-square)，以更为准确地衡量抖动的大小。在CBR业务流的多节点端-端排队时延和信元抖动性能分析中，我们提出了一种准周期性(quasi-periodic)信元流模型来描述感染了信元抖动的CBR业务流，并基于这一模型进行了CBR业务流中间节点的初步排队分析。

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。

All statistical analysis was performed using SPSS statistical software and UNPHASED Software. The genotype and allele frequency distribution were compared with χ 2 analysis, haplotype analysis was performed using UNPHASED Software., and multivariate logistic regression were used to evaluate the OR value.

统计分析使用 SPSS11.5 和 UNPHASE 软件进行，基因型分布比较用χ2 检验，通过 logistic 回归模型计算各基因型对抑郁症的相对危险度，单倍体分析用 UNPHASE 软件实现。

It is more valuable in time series analysis than unstandardized principal analysis.2 Fourier Analysis can decompose a time series signal into different frequency components, which represent different seasonal mode.3 The Phenology characteristics extracted from multi-temporal NDVI data are used for a vegetation classification.

2傅立叶分析将时间序列信号分解到不同频率成分中，各个成分分别代表了不同的周期变化模式，其中1/12频率分量概括了植被全年的单峰的季节性变化模式。 3多时相NDVI数据的时间序列分析结果中蕴含了植被的生物学信息，利用这些信息进行遥感分类。

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。

Therefore international business communication should be given the particular attention for its specialty and complicities to indicate the stylistic features of this register. Since the corpus-based approach and the computerized analyze in stylistic analysis are more accurate and more scientific, the compared data and the observation results are shown on the basis of comparison between IBC and other registers, which include LOBA, BROWN, CET4, NEC, MEE and MTE. This thesis aims at making a quantitative computerized stylistic analysis on the following aspects: graphetics, layout, punctuation, vocabulary, words of top frequency, word length, diachronic deviation, abbreviation, sentence length, passive voice, cohesive devices, sentence group and discourse analysis.

本文在国际商务英语书信文体特点分析研究的过程中，基于语料库计算机化的科学准确的分析方法，在对商务英语函电文体与普通英语文体，四级英语(CET4)，海事公约文体，航海英语文体和轮机英语比较的基础上，从书写，格式，标点符号，词汇，高频词，词长，词汇变异，缩略语，句长，被动语态，连接词，句群以及篇章模式等方面归纳总结了商务英语书信的文体特点。

First, this paper presents three girders model with double cable planes which main girder and side girder is connected by rigid arms, analyzes the dynamic characteristic of Yonghe cable-stayed bridge and obtains its natural vibration modes (i.e., frequency, damping values and the mode shapes ) by ANLSIS structural analysis program and uses these parameters as dynamic dactylogram of the intact case of cable-stayed bridge. Using the passage of random as the ambient vibration ,the dynamic properties of Yonghe Bridge is measured and the modal parameter of its 15 years after is identified and used as dynamic dactylogram of the damaged case. By the finite element analysis and locale vibration test, damaged and undamaged modal parameter is analyzed and curvature mode shape, which is sensitive to damage state, is introduced as possible candidate for identifying and locating damage in the cable-stayed bridge. Selecting the branch of part measured point from modal parameter, this paper deduces the damaged index which can detect the possible damaged location of the cable-stayed bridge deck and identifies the damaged region and degree for Yonghe Bridge. For the purpose of structural condition monitoring in in-situ , from another viewpoint, this paper introduces the method called the best optimization vector to detect damaged location and degree. The accuracy and reliability of the method presented in this paper are demonstrated by static analysis and test and the healthy state of Yonghe Bridge can be evaluated.

建立了双索面通过刚臂与主梁及边梁相连的三梁式力学模型，采用ANSYS结构分析程序对永和斜拉桥进行动力分析，对其振动模态参数进行识别，以此作为斜拉桥完好状态下的动力&指纹&；采用自由交通流作为环境振源，对永和斜拉桥动力特性进行测试，识别出永和斜拉桥使用15年后的模态参数，确立了破损状态下的动力&指纹&；利用有限元分析、现场振动测试，对破损前后的模态参数进行分析，提取对破损状况较敏感的模态曲率作为斜拉桥破损诊断的参数；并从模态参数中选取部分点的分量，导出可以指示斜拉桥桥面大概损伤位置的Index损伤指标，识别出斜拉桥发生破损的区段及破损程度；考虑大型斜拉桥在线监测要求识别破损的具体位置，从另一角度提出采用最优矢量法具体确定破损发生的位置及程度；为验证本文研究成果，对永和斜拉桥进行静力分析及静力测试，对其健康状况提出可靠的评价。

The static, modal and harmonic analysis was performed in ANSYS; static capacitance, natural frequencies for the short circuit case and the open circuit (anti-resonance) case, dynamic resistance, frequency at half-power point, dynamic inductance and mechanical quality factor were computed via static, modal analysis and harmonic analysis.

为了加速低频超声雾化栽培喷头的设计制造进程、降低研发成本，该文提出了其阻抗的测试原理电路图，建立了阻抗分析的有限元模型，在大型通用有限元分析软件ANSYS中进行了静态分析、模态分析和谐响应分析。

It inculcates justification before God on the ground of human merits.

它说明在上帝灌输在地上人类优点。

TH Leaguer has excellent Quality Control and Management System.

本公司具有完善的品管部门。