We are proudly a Ukrainian website. Our country was attacked by Russian Armed Forces on Feb. 24, 2022.
You can support the Ukrainian Army by following the link: https://u24.gov.ua/.
Even the smallest donation is hugely appreciated!
Geben Sie eine Quelle nach APA, MLA, Chicago, Harvard und anderen Zitierweisen an
Machen Sie sich mit den Listen der aktuellen Artikel, Bücher, Dissertationen, Berichten und anderer wissenschaftlichen Quellen zum Thema "Spectrum analysis" bekannt.
Neben jedem Werk im Literaturverzeichnis ist die Option "Zur Bibliographie hinzufügen" verfügbar. Nutzen Sie sie, wird Ihre bibliographische Angabe des gewählten Werkes nach der nötigen Zitierweise (APA, MLA, Harvard, Chicago, Vancouver usw.) automatisch gestaltet.
Sie können auch den vollen Text der wissenschaftlichen Publikation im PDF-Format herunterladen und eine Online-Annotation der Arbeit lesen, wenn die relevanten Parameter in den Metadaten verfügbar sind.
Zeitschriftenartikel zum Thema "Spectrum analysis":
1
Zhang, Lian Shun, und Ai Juan Shi. „Classification of Biological Spectrum Based on Principal Component Cluster Analysis“. Advanced Materials Research 605-607 (Dezember 2012): 2245–48. http://dx.doi.org/10.4028/www.scientific.net/amr.605-607.2245.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
Annotation:
Spectrums of 17 biological tissue phantoms were measured using the fiber-optic spectrometer. Then, the spectrum was preprocessed by multiplicative scatter correction method to devoice the spectrum. Afterwards the features of the spectrum were extracted via principal component analysis. Ultimately, we applied cluster analysis for the spectral features. The results showed that the accumulated credibility of the first 12 spectral principal components was 99.86% for the spectrum after preprocessing; indicating that this spectrum feature extraction might be done in the case of losing no key information. And the results showed that the 17 biological tissue phantoms can be divided into four main categories according their optical features.
2
Cokelaer, Thomas, und Juergen Hasch. „'Spectrum': Spectral Analysis in Python“. Journal of Open Source Software 2, Nr. 18 (27.10.2017): 348. http://dx.doi.org/10.21105/joss.00348.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
3
Harrar, Khaled, und Mohamed Khider. „Texture Analysis Using Multifractal Spectrum“. International Journal of Modeling and Optimization 4, Nr. 4 (August 2014): 336–41. http://dx.doi.org/10.7763/ijmo.2014.v4.396.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
4
Charleston, M. A. „Spectrum: spectral analysis of phylogenetic data“. Bioinformatics 14, Nr. 1 (01.02.1998): 98–99. http://dx.doi.org/10.1093/bioinformatics/14.1.98.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
5
Bujunuru, Anitha, und Srinivasulu Tadisetty. „Performance Analysis of Spectrum Sensing Techniques“. Journal of Advanced Research in Dynamical and Control Systems 11, Nr. 0009-SPECIAL ISSUE (25.09.2019): 355–61. http://dx.doi.org/10.5373/jardcs/v11/20192579.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
7
Long, Junbo, Haibin Wang und Peng Li. „Applications of Fractional Lower Order Frequency Spectrum Technologies to Bearing Fault Analysis“. Mathematical Problems in Engineering 2019 (27.08.2019): 1–24. http://dx.doi.org/10.1155/2019/7641383.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
Annotation:
The traditional spectral analysis method is used to study the characteristics of bearing fault signals in frequency domain, which is reasonable and effective in general cases. However, it is proved that the fault signals have heavy tails in this paper, which are α stable distribution, and 1<α<2, and even the noises belong to α stable distribution. Then the conventional spectral analysis methods degenerate and even fail under α stable distribution environment. Several improved frequency spectral analysis methods are proposed employing fractional lower order covariation or fractional lower order covariance in this paper, including fractional lower order Blackman-Tukey covariation spectrum (FLOBTCS), fractional lower order periodogram covariation spectrum (FLOPCS), and fractional lower order welch covariation spectrum (FLOWCS). In order to suppress side lobe and improve resolution, we present novel fractional lower order autoregression (FLO-AR) and fractional lower order autoregressive moving average (FLO-ARMA) parameter model frequency spectrum methods, and the calculation steps are summarized. The proposed spectrum methods are compared with the existing methods based on second-order statistics under Gaussian and SαS distribution environments, and the results show that the new algorithms have better performance than the traditional methods. Finally, the improved methods are applied to estimate frequency spectrums of the normal and outer race fault signals, and it is demonstrated that they are effective for fault diagnosis.
8
Chu, Jifeng, Fang-Fang Liao, Stefan Siegmund, Yonghui Xia und Hailong Zhu. „Nonuniform dichotomy spectrum and reducibility for nonautonomous difference equations“. Advances in Nonlinear Analysis 11, Nr. 1 (24.07.2021): 369–84. http://dx.doi.org/10.1515/anona-2020-0198.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
Annotation:
Abstract For nonautonomous linear difference equations, we introduce the notion of the so-called nonuniform dichotomy spectrum and prove a spectral theorem. As an application of the spectral theorem, we prove a reducibility result.
9
Arutyunyan, Rafael, Yuri Obukhov und Petr Vabishchevich. „NUMERICAL SIMULATION OF CHARGED FULLERENE SPECTRUM“. Mathematical Modelling and Analysis 24, Nr. 2 (18.03.2019): 263–75. http://dx.doi.org/10.3846/mma.2019.017.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
Annotation:
The mathematical model of the electron spectrum of a charged fullerene is constructed on the basis of the potential of a charged sphere and the spherically symmetric potential of an uncharged fullerene. The electron spectrum is defined as the solution of the spectral problem for the one-dimensional Schr\"odinger equation. For the numerical solution of the spectral problem, piecewise-linear finite elements are used. The computational algorithm was tested on the analytical solution of the problem of the spectrum of the hydrogen atom. For solution of matrix spectral problems, a free library for solving spectral problems of SLEPc is used. The results of calculations of the electron spectrum of a charged fullerene C60 are presented.
10
Pedersen, Steen. „Spectral Sets Whose Spectrum Is a Lattice with a Base“. Journal of Functional Analysis 141, Nr. 2 (November 1996): 496–509. http://dx.doi.org/10.1006/jfan.1996.0139.
Dahl, Jason F. „Time Aliasing Methods of Spectrum Estimation“. Diss., CLICK HERE for online access, 2003. http://contentdm.lib.byu.edu/ETD/image/etd157.pdf.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
2
鄧愛紅 und Aihong Deng. „Some studies towards improving positron lifetime spectroscopy for semiconductors“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1996. http://hub.hku.hk/bib/B31214083.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
4
Chan, Chun-yu. „Mass spectrometric analysis of selected glycoproteins“. Thesis, Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B3147942X.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
5
Tadros-Attalla, Helen. „Power spectrum analysis of redshift surveys“. Thesis, University of Oxford, 1996. https://ora.ox.ac.uk/objects/uuid:5a5786db-748e-4c78-bab8-c89a4eda2f07.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
Annotation:
This thesis describes a study of the clustering properties of galaxies and clusters of galaxies as measured by the power spectrum (P(k)) and the counts in cells statistic. The samples used are the optical Stromlo-APM galaxy survey, the APM cluster survey and the IRAS 1.2Jy, QDOT and PSCz surveys. Throughout, N-body simulations, for a variety of cosmological models, are used to test methods and to supplement analytic error estimates. For the Stromlo-APM sample the amplitude of the power spectrum is dependent on galaxy morphology. Early-type galaxies show a higher clustering amplitude than late-type galaxies by a factor of ~ 1.8. There is also tentative evidence for some dependence of the clustering amplitude on galaxy luminosity. The parameter Ω0.6/b is estimated via a comparison with the real-space power spectrum of the two-dimensional APM galaxy survey. For APM clusters the power spectrum is measured to very small wave numbers, with a possible detection of the expected turn-over. The results are inconsistent with the standard cold dark matter model. The shape of P( k) for clusters is approximately the same as that for Stromlo-APM galaxies but amplified by a factor of ~ 3.5. The power spectrum of the QDOT sample depends sensitively on the galaxy weighting scheme, probably due the manner in which the region of the Hercules supercluster is sampled. A best estimate of the power spectrum of IRAS galaxies is computed by combining the IRAS l.2Jy and QDOT samples. The PSCz galaxy power spectrum is also computed. The PSCz galaxies have a clustering amplitude twice that of optical galaxies. A similar result is found from a joint counts in cells analysis. Redshift-space distortions in the PSCz sample are analysed using a spherical harmonic decomposition of the density field. The value of Ω0.6/b = 1 is ruled out by this analysis at the 2σ significance level.
6
Mendes, Luís Miguel Vinhas. „Measurements and analysis of spectrum activity“. Master's thesis, Universidade de Aveiro, 2011. http://hdl.handle.net/10773/7725.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
Annotation:
Mestrado em Engenharia Electrónica e Telecomunicações The dissertation deals with measuring and analyzing spectrum occupancy of a GSM900 band, DCS1800 band and all UMTS bandwidth. A modelization for analog power and binary quantized power is given. In the case of analog power, histograms of the power distribution during one working day are presented. In the case of quantized power the two time statistics, the time period of opportunities distribution and the time between opportunities distribution are presented, described and modeled. The measurement setup is standing in line of sight with the base station. Also, in terms of maximum sensitivity the measurement setup is described and analyzed. Spectrum non occupancy in terms of total time for the GSM900 band and the DCS1800 band is given, for a working day. Nesta dissertação são feitas medidas e a análise de ocupação de espectro em uma banda de GSM900, uma banda de DCS1800 e toda a largura de banda do UMTS. É apresentada uma modelização para potência analógica e para a potência binária quantizada. No caso da potência analógica são apresentados histogramas da distribuição de potência ao longo de um dia útil. No caso da potência quantizada as duas estatísticas, distribuição do período de tempo de oportunidades e distribuição do tempo entre oportunidades, são apresentadas, descritas e modeladas. O setup de medida encontra-se em linha de vista com a estação base. O setup é descrito e analisado em termos de máxima sensibilidade. A desocupação de espectro em termos de tempo total para a banda de GSM900 e para a banda DCS1800 é fornecida, para um dia de útil.
7
Clayton, Michael J. „Analysis of the ultraviolet emissions of nitric oxide from mid-latitude rocket observations“. Thesis, Monterey, California : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA237340.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
Annotation:
Thesis (M.S. in Physics)--Naval Postgraduate School, June 1990. Thesis Advisor(s): Cleary, David D. "June 1990." Description based on signature page. as viewed on October 19, 2009. DTIC Identifiers: Dayglow, emission spectra, ultraviolet spectra, theses. Author(s) subject terms: Ultraviolet spectra, dayglow, nitric oxide. Includes bibliographical references (p. 57-58). Also available in print.
8
Strachan, Clare, und n/a. „Spectroscopic investigation and quantitation of polymorphism and crystallinity of pharmaceutical compounds“. University of Otago. School of Pharmacy, 2005. http://adt.otago.ac.nz./public/adt-NZDU20070427.141108.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
Annotation:
Spectroscopy is increasingly used to investigate and monitor the solid state forms of pharmaceutical materials and products. Spectroscopy�s speed, nondestructive sampling, compatibility with fibre optics and safety also make it attractive for in-line monitoring.
In this thesis, the spectroscopic techniques Fourier transform Raman spectroscopy, terahertz pulsed spectroscopy and second harmonic generation were used to characterise and quantify polymorphism and crystallinity of pharmaceutical compounds. Where possible, the multivariate analysis technique partial least squares was used for quantitative analysis. Fourier transform Raman spectroscopy detects polarisability changes mainly associated with molecular vibrations. Terahertz pulsed spectroscopy is a new spectroscopic technique that operates between the infrared and microwave regions of the electromagnetic spectrum and detects dipole moment changes mainly associated with crystalline phonon vibrations in the solid state. Second harmonic generation is a nonlinear optical phenomenon that depends on the dipole moment in crystals and crystal symmetry.
Several materials capable of existing in different solid state forms were used. FT-Raman spectroscopy was able to differentiate carbamazepine forms I and III, enalapril maleate forms I and II and γ-crystalline and amorphous indomethacin. Combined with partial least squares the technique could quantify binary mixtures of CBZ forms I and III with a limit of detection as low as 1%, and mixtures of enalapril maleate with a limit of detection of as low as 2%.
Terahertz pulsed spectroscopy obtained very different spectra for carbamazepine forms I and III, enalapril maleate forms I and II, γ-crystalline and amorphous indomethacin, crystalline and supercooled thermotropic liquid crystalline fenoprofen calcium, three forms of lactose, and five forms of sulphathiazole. At present the modes in the spectra cannot be attributed to specific phonon modes. Quantitation of binary mixtures of different forms of a compound using partial least squares analysis usually resulted in a limit of detection of about 1%.
Second harmonic generation was used to quantify binary mixtures of different forms of enalapril maleate and lactose, as well as binary mixtures of enalapril maleate form II and polyvinylpyrrolidone. A quantitative relationship was present for each of the mixtures, however the limits of detection were usually above 10%. The high value is probably due to the machine being a prototype and univariate analysis associated with a single output variable. Future improvements to the apparatus and measurement parameters are likely to reduce the limits of detection. Ranitidine hydrochloride polymorphs could also be differentiated using second harmonic generation, however γ-crystalline and amorphous indomethacin and forms I and III of carbamazepine could not.
The methods used in this thesis were successfully used for qualitative and quantitative analysis of polymorphism and crystallinity of pharmaceutical compounds. TPS and SHG are useful additions to the range of experimental techniques that can be used to investigate and monitor properties of pharmaceutical solids.
9
Youatt, Andrew Pierce. „Analyzing Edgard Varese's Ionisation Using Digital Spectral Analysis“. Thesis, The University of Arizona, 2012. http://hdl.handle.net/10150/232473.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
Annotation:
Although Robert Cogan's New Images of Musical Sound won the Society of Music Theory's Outstanding Publication Award in 1987, his musical application of spectral analysis has seen little use over the past 25 years. Spectral images are most effective at illustrating the timbre of sound, and harmony, not timbre, is the key structural component of most Western music. There are, however, some compositions in which timbre plays a critical role. Chief among these is Edgard Varèse's Ionisation, an epic percussion ensemble piece built around 40 instruments and 13 musicians. Previous analyses by Jean-Charles François and Varèse protege Chou Wen-Chung have emphasized the importance of timbre to Ionisation's construction, but are limited in their exploration of timbral qualities. Modern digital spectral analysis allows for a more accurate picture of the individual timbres that make up Ionisation and define the broader textures and structures that give the piece meaning.
10
Daigle, J. A. Bernard. „Development of an ion trap mass spectrometer for elemental analysis“. Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/30688.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
Annotation:
Mass spectrometry is a widely used technique for the performance of elemental analysis: not only does it provides excellent limits of detection for a large number of elements, but it is also able to provide information about the isotopic distribution of the analyte. The radio-frequency quadrupole ion trap is a relatively new design of mass spectrometer, which offers the ability to confine charged particles for extended periods of time in a well defined volume by applying a radio-frequency oscillating voltage to an arrangement of three electrodes. A mass analysis of the trapped ions can be obtained by selectively extracting the ions from the cavity of the trap, where they can be detected by an electron multiplier. Despite its unique capabilities, to date the applications of the ion trap mass spectrometer have mostly been restricted to gas chromatography detection. Until recently, there have been very few attempts to use it for any other types of routine analysis.
Our interest lies in the development of an instrument capable of performing a complete mass spectrometric elemental analysis of small volume liquid samples (a few (μL) at trace or ultra-trace concentration levels. The ability of the ion trap to accumulate ions in its cavity and to provide an entire mass spectrum of these ions in a single scan of the radio-frequency oscillating voltage applied between the electrodes, makes it a very interesting candidate for the ultra-trace analysis of small size samples. However, to perform an analysis on a sample with the ion trap the sample must first be vaporized; and if an elemental analysis is required, the sample will also have to be atomized. The graphite furnace atomizer used in atomic absorption spectroscopy offers a number of advantages which make it potentially useful for this purpose: it has a high transport efficiency of the analyte from liquid or solid state to the vapour phase, the ionization of the analyte in the furnace is very low (as required by the ion trap) and it handles small volume samples very well. A graphite furnace ion
trap mass spectrometer was designed to fulfil the need of having instrumentation capable of multielemental mass spectrometric analysis of small volume samples containing traces of the analytes of interest.
This document contains a description of the principles of operation of the ion trap as well as a detailed description of the instrument actually built. Data are presented in order to assess the capabilities of the instrument, as well as some of the problems encountered with it. The results obtained with the graphite furnace ion trap mass spectrometer allow us to conclude that the proposed design is not appropriate for the performance of elemental analysis, but is appropriate for mass spectrometric study of low boiling point compounds which can interfere with atomic absorption analysis: it is calculated that these compounds could be analysed at the ppm level.
Promising results obtained with a set up in which the analyte is vaporized directly into the cavity of the ion trap through laser ablation are also presented. These limited results show the potential of this methodology for direct elemental analysis of solid samples. Science, Faculty of Chemistry, Department of Graduate
APA, Harvard, Vancouver, ISO und andere Zitierweisen
9
Golyandina, Nina, Anton Korobeynikov und Anatoly Zhigljavsky. Singular Spectrum Analysis with R. Berlin, Heidelberg: Springer Berlin Heidelberg, 2018. http://dx.doi.org/10.1007/978-3-662-57380-8.
Miyara, Federico. „Spectrum Analysis“. In Modern Acoustics and Signal Processing, 245–95. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-55871-4_8.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
2
Cady, Ernest B. „Spectrum Analysis“. In Clinical Magnetic Resonance Spectroscopy, 247–68. Boston, MA: Springer US, 1990. http://dx.doi.org/10.1007/978-1-4684-1333-5_6.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
3
Weik, Martin H. „spectrum analysis“. In Computer Science and Communications Dictionary, 1634. Boston, MA: Springer US, 2000. http://dx.doi.org/10.1007/1-4020-0613-6_17898.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
5
Lang, Serge. „The Spectrum“. In Real and Functional Analysis, 400–414. New York, NY: Springer New York, 1993. http://dx.doi.org/10.1007/978-1-4612-0897-6_16.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
6
Jacobsen, Eric, und Richard Lyons. „Sliding Spectrum Analysis“. In Streamlining Digital Signal Processing, 175–88. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2012. http://dx.doi.org/10.1002/9781118316948.ch18.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
7
Turner, J. D. „Practical Spectrum Analysis“. In Instrumentation for Engineers, 180–202. New York, NY: Springer US, 1988. http://dx.doi.org/10.1007/978-1-4684-6300-2_8.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
8
Radojičić, U., K. Nordhausen und S. Taskinen. „Singular Spectrum Analysis“. In Encyclopedia of Mathematical Geosciences, 1–5. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-26050-7_294-1.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
9
Turner, J. D. „Practical Spectrum Analysis“. In Instrumentation for Engineers, 180–202. London: Macmillan Education UK, 1988. http://dx.doi.org/10.1007/978-1-349-19508-4_8.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
10
Robles-Kelly, Antonio, und Cong Phuoc Huynh. „Spectrum Representation“. In Imaging Spectroscopy for Scene Analysis, 89–140. London: Springer London, 2013. http://dx.doi.org/10.1007/978-1-4471-4652-0_7.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
Konferenzberichte zum Thema "Spectrum analysis":
1
Azimirad, M., A. R. M. Gharabaghi und M. R. Chenaghlou. „Deterministic-Spectral Fatigue Analysis of a Typical Jacket Platform (SPD1) Using Directional Wave Spectrum“. In ASME 2007 26th International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2007. http://dx.doi.org/10.1115/omae2007-29418.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
Annotation:
Fixed offshore platforms or Jacket type platforms are the most common offshore structures used for oil & gas Exploration & Production industry in Persian Gulf, because water depth is such that the shallow water condition is dominant. Sea waves as dominant environmental loading are cyclic and have random nature. The applied cyclic sea wave forces will lead to fatigue damages in jacket’s joints. There are different methods to investigate the fatigue life of jackets such as deterministic method, simplified method, spectral method and transient method. Spectral method is a suitable method, which can consider the random nature of sea waves in fatigue analysis. Deterministic-spectral method developed by Bishop et al. is used to estimate the fatigue life of shallow water jacket platforms. However, in this method the frequency spectrum of waves is used in the analysis, but generally sea waves are propagating in different directions with different frequencies, so directional wave spectrum can consider wave randomness more properly. In this paper, frequency domain spectral method using Deterministic-Spectral approach has been used to estimate the fatigue life of a typical jacket platform (SPD1 at South Pars Field - Persian Gulf). Base wave cases were chosen from joint histogram of height & period that is calculated based on scatter diagrams of South Pars Field. First the jacket was modeled by ANSYS software, then by applying base wave cases to it and analyzing the critical TT joint under internal cyclic forces, hot spot stress transfer functions at 8 nodes around the intersection of joint were obtained. Using JONSWAP standard spectrum and the spreading function proposed by Goda, sea state’s Power Spectral Densities (PSD) and directional spectrums are multiplied to obtain stress spectra. The fatigue damage and fatigue life then are calculated. Results indicate that the fatigue life based on frequency spectrum is less than the fatigue life based on directional spectrum.
2
Riza, Nabeel A., und Demetri Psaltis. „Optical disk based acousto-optic spectrum analysis“. In OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/oam.1990.tuk5.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
Annotation:
This paper introduces optical disks in acousto-optic spectrum analyzers. In 2-D time and space integrating acousto-optic folded spectrum analyzers, electronic reference signals are used in the temporal spectral processing. In order to obtain complete folded spectrums, these reference signals have to be of extremely high timebandwidth product, and require extremely fast serial readout rates. It is difficult to generate these signals using electronics, and so far, only incomplete folded spectrums have been obtained. We address the signal generation problem by combining the angular motion, high storage capacity, and parallel access capability of optical disks. The disk is introduced as an optical distributed local oscillator generator and a light sampling 1-D spatial light modulator. The distributed local oscillator architecture forms the basis of a continuous wave 1-D time integrating spectrum analyzer. The reference signals are stored as concentric channels on the disk surface. When the disk spins with a constant angular velocity, each circular channel acts as a modulating light source with a specific on/off frequency. This angular motion creates an array of temporal oscillators along the radial direction of the disk. When the input test signal frequency matches one of the disk channel temporal frequencies, a positive build-up of charge occurs on the time integrating detector, indicating a frequency match. A simple disk system is demonstrated in the laboratory. The disk can also be used in a 2-D time and space integrating architecture, where radial sections of the disk are used for storing the columns of a DFT matrix used for temporal spectrum analysis.
3
Skinner, A. D. „Spectrum analysis“. In 14th IEE Microwave Measurements Training Course. IEE, 2005. http://dx.doi.org/10.1049/ic:20050156.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
4
Xu, HongKun, Fang Fang, Shijun Ni, Jianfeng He und Lei You. „Gamma Spectrum Analysis of Chang’E-1 for Lunar Detection“. In 18th International Conference on Nuclear Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/icone18-29126.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
Annotation:
Gamma-ray spectrum analysis was essential for detecting the elemental abundance and distribution in lunar science. However, for the low-energy region of gamma-ray spectrum, weak peaks were implicated in the fast-decreasing background, and it was difficult to extract characteristic information from original spectra. In order to get a better analytic result, based on wavelet and FFT filtering methods in frequency domain, we had processed the gamma-ray spectrometer (GRS) data of Chang’E-1 (CE-1), and well extracted some useful information of spectral characteristic peaks. Then we preliminarily mapped the distribution of net peak counts for potassium on lunar surface, which indirectly reflected the distribution of elemental abundance. At last, we compared our analytic result with that of Apollo and Lunar Prospector (LP), and found some consistencies and differences.
5
Preppernau, B. L., und P. J. Hargis. „Trace Organic Chemical Detection Using an Ultraviolet Excitation Molecular Beam Fluorometer“. In Laser Applications to Chemical Analysis. Washington, D.C.: Optica Publishing Group, 1994. http://dx.doi.org/10.1364/laca.1994.tub.5.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
Annotation:
Detection of air-borne environmental contaminants, such as organic solvents, requires unambiguous compound identification and sensitivity to concentrations below those permitted by regulating agencies. One promising detection approach uses a pulsed supersonic molecular beam vacuum expansion in combination with fluorescence signal spectral analysis to identify species in a chemical mixture. Expanding a contaminated atmospheric sample through a supersonic molecular beam expansion acts to cool the sample and greatly reduce the spectral density in a fluorescence or photoionization spectrum. Most organic contaminants of interest have electronic transitions in the ultraviolet with near-featureless broad band fluorescence spectra when recorded at atmospheric pressure and room temperature. By using a supersonic vacuum expansion, cooling to within a few degrees of absolute zero can reduce the effective rotational and translational temperatures of the sample molecules and provide a sharply defined spectra which can be used to unambiguously identify specific molecules and their concentrations.
6
Tangyunyong, Paiboon, Edward I. Cole, Guillermo M. Loubriel, Joshua Beutler, Darlene M. Udoni, Biliana S. Paskaleva und Thomas E. Buchheit. „Power Spectrum Analysis“. In ISTFA 2017. ASM International, 2017. http://dx.doi.org/10.31399/asm.cp.istfa2017p0073.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
Annotation:
Abstract We present a new, non-destructive electrical technique, Power Spectrum Analysis (PSA). PSA as described here uses off-normal biasing, an unconventional way of powering microelectronics devices. PSA with off-normal biasing can be used to detect subtle differences between microelectronic devices. These differences, in many cases, cannot be detected by conventional electrical testing. In this paper, we highlight PSA applications related to aging and counterfeit detection.
7
Dai, Bin, Christopher Jones, Jimmy Price, Darren Gascooke und Anthony Van Zuilekom. „COMPRESSIVE SENSING BASED OPTICAL SPECTROMETER FOR DOWNHOLE FLUID ANALYSIS“. In 2021 SPWLA 62nd Annual Logging Symposium Online. Society of Petrophysicists and Well Log Analysts, 2021. http://dx.doi.org/10.30632/spwla-2021-0112.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
Annotation:
Downhole fluid analysis has the potential to resolve ambiguity in very complex reservoirs. Downhole fluid spectra contain a wealth of information to fingerprint a fluid and help to assess continuity. Commonly, a narrowband spectrometer with limited number of channels is used to acquire optical spectra of downhole fluid. The spectral resolution of this type of spectrometer is low due to limited number of narrowband channels. In this paper, we demonstrate a new type, compressive sensing (CS) based broadband spectrometer that provides accurate and high-resolution spectral measurement. Several specially designed broadband filters are used to simplify the mechanical, electrical, optical, and computational construction of a spectrometer, therefore provides measurement of fluid spectrum with high signal-to-noise ratio, robustness, and a broader spectral range. The compressive sensing spectrometer relies on reconstruction technique to compute the optical spectrum. Based on a large spectral database, containing more than 10000 spectra of various fluids at different temperature and pressure conditions, which were collected using conventional high resolution spectrometer in a lab, the basis functions of the optical spectra of three types of fluids (water, oil and gas/condensate) can be extracted. The reconstruction algorithm first classifies the fluid into one of three fluid types based on multichannel CS spectrometer measurements, the optical spectrum is reconstructed by using linear combination of the basis functions of corresponding fluid type, with weighting coefficients determined by minimizing the difference between calculated detector responses and measured detector responses across multiple optical channels. The reconstructed data may then be used for purposes such as contamination measurement, fluid property trends for reservoir continuity assessment, and digital sampling. Digital sampling is the process of extrapolating clean fluid properties from formation fluids not physically sampled. The reconstruction spectrum covers wavelengths from 500 nm to 3300 nm, which is a wider spectral region than has historically been accessible to formation testers. The expanded wavelength range allows access of the mid-infrared spectral region for which synthetic drilling-fluid components typically have higher optical absorbance. This reconstruction spectra may allow contamination to be directly determined. This paper will discuss the CS optical spectrometer design, fluid classification and spectral reconstruction algorithm. In addition, the applicability of the technique to fluid continuity assessment, sample contamination assessment and digital sampling will also be discussed.
8
Nguyen, Hung, und Tien Nguyen. „Power Spectral Analysis for Spectrum Packing Efficiency Evaluation“. In 21st International Communications Satellite Systems Conference and Exhibit. Reston, Virigina: American Institute of Aeronautics and Astronautics, 2003. http://dx.doi.org/10.2514/6.2003-2238.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
9
Colice, Max, Friso Schlottau, Kelvin Wagner, R. Krishna Mohan, William R. Babbitt, Ivan Lorgere und Jean-Louis Le Gouet. „RF spectrum analysis in spectral hole burning media“. In Optical Science and Technology, the SPIE 49th Annual Meeting, herausgegeben von Bahram Javidi und Demetri Psaltis. SPIE, 2004. http://dx.doi.org/10.1117/12.560074.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
10
Gao, Xiang, Xiaozhou Ma, Yuxiang Ma, Guohai Dong und Junliang Gao. „Characteristic Analysis for Spectrum of Swell Dominated Seas With In-Situ Measurements“. In ASME 2020 39th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/omae2020-18522.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
Annotation:
Abstract The characteristics of wave spectrum in the swell dominated seas (i.e., the Chancay Bay on the western coast of Peru) are studied based on directional wave spectra measured using the technique of acoustic Doppler current profiler (ADCP). According to the wave rose diagram and the measured wave spectra, this sea area is mainly affected by the swell of the southwest direction and the significant wave height is between 0.7m-2.6m. Moreover, the wave spectra feature the single-peaked spectra and the double-peaked spectra. The JONSWAP spectrum model is adopted to fit single-peaked swell spectra. A close agreement could be found between the observed and fitted spectrum parameters. Hence, the JONSWAP model can be used to describe the single-peaked swell spectra in the sea area studied in this work. As for the double-peaked spectrum, Ochi-Hubble double peak spectrum model and simplified Torsethaugen double peak spectrum model are adopted to fit the wave spectra, respectively. Comparing the fitting results of two double-peaked spectrum modal, it’s possible to conclude that the measured double-peaked spectra can be well represented by the Ochi-Hubble double peak spectrum model.
Berichte der Organisationen zum Thema "Spectrum analysis":
1
Zhang, S. Y., und W. T. Weng. Spectrum analysis in beam diagnostics. Office of Scientific and Technical Information (OSTI), April 1993. http://dx.doi.org/10.2172/10156565.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
2
Stinnett, Jacob. Notre Dame Plutonium Spectrum Analysis. Office of Scientific and Technical Information (OSTI), September 2019. http://dx.doi.org/10.2172/1565811.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
3
Zhang S. Y. und W. Weng. SPECTRUM ANALYSIS IN BEAM DIAGNOSTICS. Office of Scientific and Technical Information (OSTI), April 1993. http://dx.doi.org/10.2172/1151279.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
4
Zhang, S. Y., und W. T. Weng. Spectrum analysis in beam diagnostics. Office of Scientific and Technical Information (OSTI), April 1993. http://dx.doi.org/10.2172/6536419.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
5
Morgan, William J. DoD Spectrum Management: A Critical Analysis. Fort Belvoir, VA: Defense Technical Information Center, Juni 2008. http://dx.doi.org/10.21236/ada525857.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
6
Wilson, R. D. Spectrum shape-analysis techniques applied to the Hanford Tank Farms spectral gamma logs. Office of Scientific and Technical Information (OSTI), Mai 1997. http://dx.doi.org/10.2172/501524.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
7
Anderson, I. M., und J. Bentley. Multivariate statistical analysis of spectrum lines and images. Office of Scientific and Technical Information (OSTI), April 1997. http://dx.doi.org/10.2172/505348.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
8
Bezler, P., J. R. Curreri, Y. K. Wang und A. K. Gupta. Alternate modal combination methods in response spectrum analysis. Office of Scientific and Technical Information (OSTI), Oktober 1990. http://dx.doi.org/10.2172/6433723.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
9
Anderson, I. M. Statistical analysis of low-voltage EDS spectrum images. Office of Scientific and Technical Information (OSTI), März 1998. http://dx.doi.org/10.2172/658437.
APA, Harvard, Vancouver, ISO und andere Zitierweisen
10
DeJong, Stephanie, Rosalie Multari, Kelsey Wilson und Paiboon Tangyunyong. Evaluation of COTS Electronics by Power Spectrum Analysis and Multivariate Data Analysis. Office of Scientific and Technical Information (OSTI), September 2022. http://dx.doi.org/10.2172/1890397.
