Journal articles: 'Spectral Patterns'

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Conrads, T. P., V. A. Fusaro, S. Ross, D. Johann, V. Rajapakse, B. A. Hitt, S. M. Steinberg, et al. "High-resolution serum proteomic features for ovarian cancer detection." Endocrine-related cancer 11, no. 2 (June 2004): 163–78. http://dx.doi.org/10.1677/erc.0.0110163.

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Serum proteomic pattern diagnostics is an emerging paradigm employing low-resolution mass spectrometry (MS) to generate a set of biomarker classifiers. In the present study, we utilized a well-controlled ovarian cancer serum study set to compare the sensitivity and specificity of serum proteomic diagnostic patterns acquired using a high-resolution versus a low-resolution MS platform. In blinded testing sets, the high-resolution mass spectral data contained multiple diagnostic signatures that were superior to the low-resolution spectra in terms of sensitivity and specificity (P<0.00001) throughout the range of modeling conditions. Four mass spectral feature set patterns acquired from data obtained exclusively with the high-resolution mass spectrometer were 100% specific and sensitive in their diagnosis of serum samples as being acquired from either unaffected patients or those suffering from ovarian cancer. Important to the future of proteomic pattern diagnostics is the ability to recognize inferior spectra statistically, so that those resulting from a specific process error are recognized prior to their potentially incorrect (and damaging) diagnosis. To meet this need, we have developed a series of quality-assurance and in-process control procedures to (a) globally evaluate sources of sample variability, (b) identify outlying mass spectra, and (c) develop quality-control release specifications. From these quality-assurance and control (QA/QC) specifications, we identified 32 mass spectra out of the total 248 that showed statistically significant differences from the norm. Hence, 216 of the initial 248 high-resolution mass spectra were determined to be of high quality and were remodeled by pattern-recognition analysis. Again, we obtained four mass spectral feature set patterns that also exhibited 100% sensitivity and specificity in blinded validation tests (68/68 cancer: including 18/18 stage I, and 43/43 healthy). We conclude that (a) the use of high-resolution MS yields superior classification patterns as compared with those obtained with lower resolution instrumentation; (b) although the process error that we discovered did not have a deleterious impact on the present results obtained from proteomic pattern analysis, the major source of spectral variability emanated from mass spectral acquisition, and not bias at the clinical collection site; (c) this variability can be reduced and monitored through the use of QA/QC statistical procedures; (d) multiple and distinct proteomic patterns, comprising low molecular weight biomarkers, detected by high-resolution MS achieve accuracies surpassing individual biomarkers, warranting validation in a large clinical study.

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Cavers, Michael, Jonathan Fischer, and Kevin N. Vander Meulen. "Spectral Properties of Sign Patterns." Electronic Journal of Linear Algebra 36, no. 36 (April 5, 2020): 183–97. http://dx.doi.org/10.13001/ela.2020.5057.

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In this paper, an infinite family of irreducible sign patterns that are spectrally arbitrary, for which the nilpotent-Jacobian method does not apply, is given. It is demonstrated that it is possible for an irreducible sign pattern to be refined inertially arbitrary and not spectrally arbitrary. It is observed that not every nonzero spectrally arbitrary pattern has a signing which is spectrally arbitrary. It is also shown that every superpattern of the reducible pattern $\T_2 \oplus \T_2$ is spectrally arbitrary.

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Espejo, Antonio, Paula Camus, Iñigo J. Losada, and Fernando J. Méndez. "Spectral Ocean Wave Climate Variability Based on Atmospheric Circulation Patterns." Journal of Physical Oceanography 44, no. 8 (August 1, 2014): 2139–52. http://dx.doi.org/10.1175/jpo-d-13-0276.1.

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Abstract Traditional approaches for assessing wave climate variability have been broadly focused on aggregated or statistical parameters such as significant wave height, wave energy flux, or mean wave direction. These studies, although revealing the major general modes of wave climate variability and trends, do not take into consideration the complexity of the wind-wave fields. Because ocean waves are the response to both local and remote winds, analyzing the directional full spectra can shed light on atmospheric circulation not only over the immediate ocean region, but also over a broad basin scale. In this work, the authors use a pattern classification approach to explore wave climate variability in the frequency–direction domain. This approach identifies atmospheric circulation patterns of the sea level pressure from the 31-yr long Climate Forecast System Reanalysis (CFSR) and wave spectral patterns of two selected buoys in the North Atlantic, finding one-to-one relations between each synoptic pattern (circulation type) and each spectral wave energy distribution (spectral type). Even in the absence of long-wave records, this method allows for the reconstruction of long-term wave spectra to cover variability at several temporal scales: daily, monthly, seasonal, interannual, decadal, long-term trends, and future climate change projections.

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Devaux, M. F., D. Bertrand, P. Robert, and M. Qannari. "Application of Principal Component Analysis on NIR Spectral Collection after Elimination of Interference by a Least-Squares Procedure." Applied Spectroscopy 42, no. 6 (August 1988): 1020–23. http://dx.doi.org/10.1366/0003702884430443.

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In NIR spectroscopy, multidimensional analyses such as Principal Component Analysis (PCA) may be applied to examine the similarity between spectra of natural products. However, such an approach is often limited by the effect of spectral interference due to water or particle size distribution of the samples. In the present work, the advantage of the elimination of such spectral interference before performing PCA was investigated. Unwanted component spectra were eliminated by a least-squares procedure. They were first orthogonalized and normalized by the Gram-Schmidt orthogonalization method. The subtraction coefficients were then assessed, similarly to principal component (PC) scores, by projection of the NIR spectra on the orthogonalized component spectra, and PCA was performed on the corrected spectra. This method was applied on an illustrative collection of wheat semolina conditioned in three levels of water content. Water was the component to be eliminated and had been previously modeled by two spectral patterns. These spectral patterns were used as the unwanted component spectra. PCA was applied independently before and after spectral correction of the collection of spectra and graphs obtained by the two procedures were compared. The squared correlation coefficient of the 3 first PC scores with water content was 0.979 before correction, with the 3 groups of water content appearing clearly on PCA graphs. After correction, the corresponding squared correlation coefficient for the 7 first PC scores was 0.016. PCA graphs obtained with corrected spectra also showed that the water effect was completely eliminated. At this moment, samples were separated according to their technological nature. The procedure developed may be useful in pattern recognition study and for automatic clustering of NIR spectra. It may also be applied in fields other than NIR spectroscopy.

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Rose, John P., and Michael E. Kellman. "Spectral Patterns of Chaotic Acetylene†." Journal of Physical Chemistry A 104, no. 45 (November 2000): 10471–81. http://dx.doi.org/10.1021/jp001424i.

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Stéphan, G. M. "Spectral properties in laser patterns." Quantum and Semiclassical Optics: Journal of the European Optical Society Part B 10, no. 6 (December 1998): 849–60. http://dx.doi.org/10.1088/1355-5111/10/6/016.

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Yang, Shuangbo, Vivian Tyng, and Michael E. Kellman. "Spectral Patterns of Isomerizing Systems‡." Journal of Physical Chemistry A 107, no. 40 (October 2003): 8345–54. http://dx.doi.org/10.1021/jp027763o.

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Barker, James, Michael Jones, and Melvyn Kilner. "Amidine mass spectral fragmentation patterns." Organic Mass Spectrometry 20, no. 10 (October 1985): 619–23. http://dx.doi.org/10.1002/oms.1210201006.

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ARAÚJO, Edmary Silveira Barreto, João Domingos SCALON, and Lurimar Smera BATISTA. "EXPLORATORY SPECTRAL ANALYSIS IN THREE-DIMENSIONAL SPATIAL POINT PATTERNS." REVISTA BRASILEIRA DE BIOMETRIA 39, no. 1 (March 31, 2021): 177–93. http://dx.doi.org/10.28951/rbb.v39i1.524.

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A spatial point pattern is a collection of points irregularly located within a bounded area (2D) or space (3D) that have been generated by some form of stochastic mechanism. Examples of point patterns include locations of trees in a forest, of cases of a disease in a region, or of particles in a microscopic section of a composite material. Spatial Point pattern analysis is used mostly to determine the absence (completely spatial randomness) or presence (regularity and clustering) of spatial dependence structure of the locations. Methods based on the space domain are widely used for this purpose, while methods conducted in the frequency domain (spectral analysis) are still unknown to most researchers. Spectral analysis is a powerful tool to investigate spatial point patterns, since it does not assume any structural characteristics of the data (ex. isotropy), and uses only the autocovariance function, and its Fourier transform. There are some methods based on the spectral frameworks for analyzing 2D spatial point patterns. There is no such methods available for the 3D situation and, therefore, the aim of this work is to develop new methods based on spectral framework for the analysis of three-dimensional point patterns. The emphasis is on relating periodogram structure to the type of stochastic process which could have generated a 3D observed pattern. The results show that the methods based on spectral analysis developed in this work are able to identify patterns of three typical three-dimensional point processes, and can be used, concurrently, with analyzes in the space domain for a better characterization of spatial point patterns.

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Taşcıoğlu, Didem, Arda Atçı, Seçil Sevim Ünlütürk, and Serdar Özçelik. "Physically unclonable security patterns created by electrospinning, and authenticated by two-step validation method." Nanotechnology 33, no. 9 (December 9, 2021): 095302. http://dx.doi.org/10.1088/1361-6528/ac3b0d.

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Abstract Counterfeiting is a growing economic and social problem. For anticounterfeiting, random and inimitable droplet/fiber patterns were created by the electrospinning method as security tags that are detectable under UV light but invisible in daylight. To check the authenticity of the original security patterns created; images were collected with a simple smartphone microscope and a database of the recorded original patterns was created. The originality of the random patterns was checked by comparing them with the patterns recorded in the database. In addition, the spectral signature of the patterns in the droplet/fiber network was obtained with a simple and hand-held spectrometer. Thus, by reading the spectral signature from the pattern, the spectral information of the photoluminescent nanoparticles was verified and thus a second-step verification was established. In this way, anticounterfeiting technology that combines ink formula, unclonable security pattern creation and two-level verification is developed.

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Akkaynak, Derya, Liese A. Siemann, Alexandra Barbosa, and Lydia M. Mäthger. "Changeable camouflage: how well can flounder resemble the colour and spatial scale of substrates in their natural habitats?" Royal Society Open Science 4, no. 3 (March 2017): 160824. http://dx.doi.org/10.1098/rsos.160824.

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Flounder change colour and pattern for camouflage. We used a spectrometer to measure reflectance spectra and a digital camera to capture body patterns of two flounder species camouflaged on four natural backgrounds of different spatial scale (sand, small gravel, large gravel and rocks). We quantified the degree of spectral match between flounder and background relative to the situation of perfect camouflage in which flounder and background were assumed to have identical spectral distribution. Computations were carried out for three biologically relevant observers: monochromatic squid, dichromatic crab and trichromatic guitarfish. Our computations present a new approach to analysing datasets with multiple spectra that have large variance. Furthermore, to investigate the spatial match between flounder and background, images of flounder patterns were analysed using a custom program originally developed to study cuttlefish camouflage. Our results show that all flounder and background spectra fall within the same colour gamut and that, in terms of different observer visual systems, flounder matched most substrates in luminance and colour contrast. Flounder matched the spatial scales of all substrates except for rocks. We discuss findings in terms of flounder biology; furthermore, we discuss our methodology in light of hyperspectral technologies that combine high-resolution spectral and spatial imaging.

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Lü, Lian-Zhong, En-Wei Liang, and Bertrand Cordier. "The Spectral Evolution Patterns and Implications of Gamma-Ray Burst X-Ray Flares." Astrophysical Journal 941, no. 1 (December 1, 2022): 99. http://dx.doi.org/10.3847/1538-4357/ac9613.

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Abstract We present a time-resolved spectral analysis of bright X-ray flares observed by Swift X-ray telescope from 2004 December to 2021 December. We selected 58 bright flares from 56 gamma-ray burst X-ray afterglows to perform time-resolved spectral analysis. We find that there is a strong spectral evolution in X-ray flares. Spectral evolution exists in all the X-ray flares. We have not found flares without spectral evolutions in our samples. The spectrum of an X-ray afterglow is dominated by the flare when it exists. Four spectral evolution patterns were found, i.e., hard-to-soft, intensity tracking, soft-to-hard, and anti-intensity tracking. Most of the flares (46 flares, 79.3%) show a spectral evolution from hard to soft. Five (8.6%) flares are intensity tracking. Two (3.5%) flares show soft-to-hard. Five (8.6%) flares show anti-intensity tracking. Therefore, hard-to-soft spectral evolution patterns dominate the spectral evolutions of X-ray flares. In other words, the hard-to-soft spectral evolution pattern is the main evolution pattern of X-ray flares. Hard-to-soft, intensity tracking, and soft-to-hard spectral evolution patterns are the same as prompt emission spectral evolutions, indicating that the origin of flares should be the same as prompt emissions and the flares are the lower energy band emissions of the prompt emissions. The spectral evolution intensities are independent of the peak time and FWHM of the flares. In other words, the spectral evolution intensity is irrelevant to the flare occurrence time and its duration but related to the peak fluxes of flares. This means that the more luminous the flares, the stronger the spectral evolutions.

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Bergfeldt, Lennart, and Yoshiyuki Haga. "Power spectral and Poincaré plot characteristics in sinus node dysfunction." Journal of Applied Physiology 94, no. 6 (June 1, 2003): 2217–24. http://dx.doi.org/10.1152/japplphysiol.01037.2002.

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A salient feature of the normal sinus node activity is its prominent beat-to-beat variability, which shows self-similarity on different time scales (fractal dynamics). However, in patients with sinus node dysfunction, short-term time sinus cycles show exaggerated variability, the characteristics of which have not been analyzed. Therefore, Poincaré plots and power spectral analysis were applied to short-term variations of sinus cycles in 30 patients with and 30 patients without sinus node disease. Three patterns of behavior were observed in sick sinus patients: type 1, completely normal ( n = 3); type 2, randomlike pattern in the Poincaré plots with “white noise” power spectra ( n = 9); and type 3, a transitional pattern, characterized by remnants of normal behavior mixed with scattered points ( n = 18). In control subjects, only type 1 ( n = 27) and type 3 ( n = 3) patterns were observed, P < 0.0001. The power spectral changes in sinus node dysfunction are thus characterized by a loss of the inverse power law relationship, which both has implications for heart rate variability analysis and might offer a new diagnostic approach.

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Zhang, Yongshan, Xinwei Jiang, Xinxin Wang, and Zhihua Cai. "Spectral-Spatial Hyperspectral Image Classification with Superpixel Pattern and Extreme Learning Machine." Remote Sensing 11, no. 17 (August 22, 2019): 1983. http://dx.doi.org/10.3390/rs11171983.

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Spectral-spatial classification of hyperspectral images (HSIs) has recently attracted great attention in the research domain of remote sensing. It is well-known that, in remote sensing applications, spectral features are the fundamental information and spatial patterns provide the complementary information. With both spectral features and spatial patterns, hyperspectral image (HSI) applications can be fully explored and the classification performance can be greatly improved. In reality, spatial patterns can be extracted to represent a line, a clustering of points or image texture, which denote the local or global spatial characteristic of HSIs. In this paper, we propose a spectral-spatial HSI classification model based on superpixel pattern (SP) and kernel based extreme learning machine (KELM), called SP-KELM, to identify the land covers of pixels in HSIs. In the proposed SP-KELM model, superpixel pattern features are extracted by an advanced principal component analysis (PCA), which is based on superpixel segmentation in HSIs and used to denote spatial information. The KELM method is then employed to be a classifier in the proposed spectral-spatial model with both the original spectral features and the extracted spatial pattern features. Experimental results on three publicly available HSI datasets verify the effectiveness of the proposed SP-KELM model, with the performance improvement of 10% over the spectral approaches.

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Kovacs, Zoltan, Bernhard Pollner, George Bazar, Jelena Muncan, and Roumiana Tsenkova. "A Novel Tool for Visualization of Water Molecular Structure and Its Changes, Expressed on the Scale of Temperature Influence." Molecules 25, no. 9 (May 9, 2020): 2234. http://dx.doi.org/10.3390/molecules25092234.

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Aquaphotomics utilizes water-light interaction for in-depth exploration of water, its structure and role in aqueous and biologic systems. The aquagram, a major analytical tool of aquaphotomics, allows comparison of water molecular structures of different samples by comparing their respective absorbance spectral patterns. Temperature is the strongest perturbation of water changing almost all water species. To better interpret and understand spectral patterns, the objective of this work was to develop a novel, temperature-scaled aquagram that provides standardized information about changes in water molecular structure caused by solutes, with its effects translated to those which would have been caused by respective temperature changes. NIR spectra of Milli-Q water in the temperature range of 20–70 °C and aqueous solutions of potassium chloride in concentration range of 1 to 1000 mM were recorded to demonstrate the applicability of the proposed novel tool. The obtained results presented the influence of salt on the water molecular structure expressed as the equivalent effect of temperature in degrees of Celsius. The temperature-based aquagrams showed the well-known structure breaking and structure making effects of salts on water spectral pattern, for the first time presented in the terms of temperature influence on pure water. This new method enables comparison of spectral patterns providing a universal tool for evaluation of various bio-aqueous systems which can provide better insight into the system’s functionality.

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Dravins, Dainis, Hans-Günter Ludwig, and Bernd Freytag. "Spatially resolved spectroscopy across stellar surfaces." Astronomy & Astrophysics 649 (April 28, 2021): A16. http://dx.doi.org/10.1051/0004-6361/202039995.

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Context. High-precision stellar analyses require hydrodynamic 3D modeling. Such models predict changes across stellar disks of spectral line shapes, asymmetries, and wavelength shifts. For testing models in stars other than the Sun, spatially resolved observations are feasible from differential spectroscopy during exoplanet transits, retrieving spectra of those stellar surface segments that successively become hidden behind the transiting planet, as demonstrated in Papers I, II, and III. Aims. Synthetic high-resolution spectra over extended spectral regions are now available from 3D models. Similar to other ab initio simulations in astrophysics, these data contain patterns that have not been specifically modeled but may be revealed after analyses to be analogous to those of a large volume of observations. Methods. From five 3D models spanning Teff = 3964–6726 K (spectral types ~K8 V–F3 V), synthetic spectra at hyper-high resolution (λ/Δλ >1 000 000) were analyzed. Selected Fe I and Fe II lines at various positions across stellar disks were searched for characteristic patterns between different types of lines in the same star and for similar lines between different stars. Results. Spectral-line patterns are identified for representative photospheric lines of different strengths, excitation potentials, and ionization levels, thereby encoding the hydrodynamic 3D structure. Line profiles and bisectors are shown for various stars at different positions across stellar disks. Absolute convective wavelength shifts are obtained as differences to 1D models, where such shifts do not occur. Conclusions. Observable relationships for line properties are retrieved from realistically complex synthetic spectra. Such patterns may also test very detailed 3D modeling, including non-LTE effects. While present results are obtained at hyper-high spectral resolution, the subsequent Paper V examines their practical observability at realistically lower resolutions, and in the presence of noise.

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Linz, Jill A., and Christian Howat. "Atom Tones: investigating waveforms and spectra of atomic elements in an audible periodic chart using techniques found in music production." Journal of the Acoustical Society of America 152, no. 4 (October 2022): A220. http://dx.doi.org/10.1121/10.0016071.

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Atom Music was introduced in 2019 as a way to create unique audible tones for each atomic element that are direct translations of that element’s spectral lines. Each atomic element produces a unique spectral line pattern that can be recognized as the fingerprint of that element. Sonification is the process of translating non-audible data into audible signals as a way to gain an understanding of the original data. In this paper, sonification is applied to atomic spectra, using technology primarily from music production. These were applied to atomic spectra using additive synthesis methods and analyzed using digital audio workstations. Interest in the audible tones has primarily been in element identification through each tone, as well as those interested in musical interpretation. We investigate what insights can be made by observing the digital waveforms and spectra of each element tone. We consider whether there are patterns within the different element waveforms; if there is any correlation between the elements producing similar beat patterns; and if there are any harmonic relations between electron states that are represented by the spectra itself. Results indicate that this method could be a useful tool in investigating atomic structure.

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Saoji, Aniket A., and David A. Eddins. "Spectral modulation masking patterns reveal tuning to spectral envelope frequency." Journal of the Acoustical Society of America 122, no. 2 (August 2007): 1004–13. http://dx.doi.org/10.1121/1.2751267.

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Svitak, John, Zhiming Li, John Rose, and Michael E. Kellman. "Spectral patterns and dynamical bifurcation analysis of highly excited vibrational spectra." Journal of Chemical Physics 102, no. 11 (March 15, 1995): 4340–54. http://dx.doi.org/10.1063/1.469483.

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Saoji, Aniket, and David A. Eddins. "Masking patterns for simple spectral stimuli." Journal of the Acoustical Society of America 109, no. 5 (May 2001): 2465–66. http://dx.doi.org/10.1121/1.4744747.

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Saoji, Aniket, and David A. Eddins. "Sinusoidal spectral modulation masking period patterns." Journal of the Acoustical Society of America 115, no. 5 (May 2004): 2603. http://dx.doi.org/10.1121/1.4784623.

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Van, Que N., John R. Klose, David A. Lucas, DaRue A. Prieto, Brian Luke, Jack Collins, Stanley K. Burt, et al. "The Use of Urine Proteomic and Metabonomic Patterns for the Diagnosis of Interstitial Cystitis and Bacterial Cystitis." Disease Markers 19, no. 4-5 (2004): 169–83. http://dx.doi.org/10.1155/2004/530647.

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The advent of systems biology approaches that have stemmed from the sequencing of the human genome has led to the search for new methods to diagnose diseases. While much effort has been focused on the identification of disease-specific biomarkers, recent efforts are underway toward the use of proteomic and metabonomic patterns to indicate disease. We have developed and contrasted the use of both proteomic and metabonomic patterns in urine for the detection of interstitial cystitis (IC). The methodology relies on advanced bioinformatics to scrutinize information contained within mass spectrometry (MS) and high-resolution proton nuclear magnetic resonance (1H-NMR) spectral patterns to distinguish IC-affected from non-affected individuals as well as those suffering from bacterial cystitis (BC). We have applied a novel pattern recognition tool that employs an unsupervised system (self-organizing-type cluster mapping) as a fitness test for a supervised system (a genetic algorithm). With this approach, a training set comprised of mass spectra and1H-NMR spectra from urine derived from either unaffected individuals or patients with IC is employed so that the most fit combination of relative, normalized intensity features defined at precisem/zor chemical shift values plotted inn-space can reliably distinguish the cohorts used in training. Using this bioinformatic approach, we were able to discriminate spectral patterns associated with IC-affected, BC-affected, and unaffected patients with a success rate of approximately 84%.

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Devaux, M. F., D. Bertrand, P. Robert, and M. Qannari. "Application of Multidimensional Analyses to the Extraction of Discriminant Spectral Patterns from NIR Spectra." Applied Spectroscopy 42, no. 6 (August 1988): 1015–19. http://dx.doi.org/10.1366/0003702884430227.

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A method for extracting NIR discriminant spectral patterns without any reference to chemical values is suggested. First, groups of samples have to be defined a priori. Second, this method involves two procedures: the application of Principal Component Analysis (PCA) on spectral data and Factorial Discriminant Analysis (FDA) on the PC scores. Discriminant spectral patterns are assessed as linear combinations of PCA eigenvectors with weights determined by FDA. This method was applied on an illustrative collection of wheat semolina conditioned at 3 levels of water concentration. Three groups were made on the basis of the 3 water levels. Two discriminant spectral patterns representative of water concentration were extracted. They showed the commonly known bands of water at 1940 and 1450 nm. The band at 1450 nm was resolved into two bands at 1410 and 1460 nm, which could be assigned to free and bound OH, respectively. The discriminant spectral patterns therefore modeled the relative proportion of free and bound water. Suitability of the method for other applications is discussed.

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Leinonen, Lea, Jari Kangas, Kari Torkkola, and Anja Juvas. "Dysphonia Detected by Pattern Recognition of Spectral Composition." Journal of Speech, Language, and Hearing Research 35, no. 2 (April 1992): 287–95. http://dx.doi.org/10.1044/jshr.3502.287.

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The vowel [a:] in a test word, judged normal or dysphonic, was examined with the Self-Organizing Map, the artificial neural network algorithm of Kohonen. The algorithm produces two-dimensional representations (maps) of speech. Input to the acoustic maps consisted of 15-component spectral vectors calculated at 9.83-msec intervals from short-time power spectra. The male and female maps were first calculated from the speech of healthy subjects and then the [a:] samples (15 successive spectral vectors) were examined on the maps. The dysphonic voices deviated from the norm both in the composition of the short-time power spectra (characterized by the dislocation of the trajectory pattern on the map) and in the stability of the spectrum during the performance (characterized by the pattern of the trajectory on the map). Rough voices were distinguished from breathy ones by their patterns on the map. With the limited speech material, an index for the degree of pathology could not be determined. A self-organized acoustic map provides an on-line visual representation of voice and speech in an easily understandable form. The method is thus suitable not only for diagnostic but also for educational and therapeutic purposes.

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Qiu, Ye, Ying Sun, and Yue Wu. "Characteristics of Wind Loads on Spherical Shells with Large Rise-Span Ratio." Advanced Materials Research 163-167 (December 2010): 4149–55. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.4149.

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Characteristics of wind pressure distributions over the spherical shell with 3/4 rise-span ratio have been investigated based on the data obtained from a wind tunnel experiment. A discussion of the spectral characteristics including shape of wind pressure spectra, reduced frequency corresponding to the peak spectral amplitude, and spectral slope in high frequency range is also made. The results show that the normalized pressure spectra has a broadband peak at a reduced frequency between 0.15 and 0.50, the slope of Sp( f ) in a high frequency range varies from -1.85 to -0.30 and the reduced peak frequency depends on the tapping locations. Though spectral patterns change from place to place, standard normalized spectra associated with various zones of spherical shell could be appropriately classified based on identical spectral characteristics. On this basis, an empirical spectral equation is figured out including three parts which represent the contribution of approach turbulence, turbulence induced by separation on the top of spherical shell and wake turbulence respectively. The accuracy of model is verified by comparison with the measured spectra results.

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Kang, Dongshik, Sigeru Omatu, and Michifumi Yoshioka. "Fast Neuro-Classification of New and Used Bills Using Spectral Patterns of Acoustic Data." Journal of Advanced Computational Intelligence and Intelligent Informatics 4, no. 1 (January 20, 2000): 12–17. http://dx.doi.org/10.20965/jaciii.2000.p0012.

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An advanced neuro-classification of new and used bills using the spectral patterns is proposed. An acoustic spectral pattern is obtained from the output of the two-stage adaptive digital filters (ADFs) for time-series acoustic data. The acoustic spectral patterns are fed to a competitive neural network, and classified into some categories which show worn-out degrees of the bill. The proposed method is based on extension of an ADF, an individual adaptation (IA) algorithm, and a learning vector quantization (LVQ) algorithm. The experimental results show that the proposed method is useful to classify new and used bills.

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Verweyen, A., A. N. Grum-Grzhimailo, and N. M. Kabachnik. "Sum rules and spectral patterns of dichroism in inner-shell photoelectron spectra." Physical Review A 60, no. 3 (September 1, 1999): 2076–90. http://dx.doi.org/10.1103/physreva.60.2076.

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Hannachi, A. "A New Set of Orthogonal Patterns in Weather and Climate: Optimally Interpolated Patterns." Journal of Climate 21, no. 24 (December 15, 2008): 6724–38. http://dx.doi.org/10.1175/2008jcli2328.1.

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Abstract A new spectral-based approach is presented to find orthogonal patterns from gridded weather/climate data. The method is based on optimizing the interpolation error variance. The optimally interpolated patterns (OIP) are then given by the eigenvectors of the interpolation error covariance matrix, obtained using the cross-spectral matrix. The formulation of the approach is presented, and the application to low-dimension stochastic toy models and to various reanalyses datasets is performed. In particular, it is found that the lowest-frequency patterns correspond to largest eigenvalues, that is, variances, of the interpolation error matrix. The approach has been applied to the Northern Hemispheric (NH) and tropical sea level pressure (SLP) and to the Indian Ocean sea surface temperature (SST). Two main OIP patterns are found for the NH SLP representing respectively the North Atlantic Oscillation and the North Pacific pattern. The leading tropical SLP OIP represents the Southern Oscillation. For the Indian Ocean SST, the leading OIP pattern shows a tripole-like structure having one sign over the eastern and north- and southwestern parts and an opposite sign in the remaining parts of the basin. The pattern is also found to have a high lagged correlation with the Niño-3 index with 6-months lag.

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Lousada, Marisa Lobo, Luis M. T. Jesus, and Daniel Pape. "Estimation of stops' spectral place cues using multitaper techniques." DELTA: Documentação de Estudos em Lingüística Teórica e Aplicada 28, no. 1 (2012): 1–26. http://dx.doi.org/10.1590/s0102-44502012000100001.

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This study focuses on the spectral characteristics of the European Portuguese stops /p, b, t, d, k, g/ produced by six native speakers. We analysed the spectral peaks and troughs by means of multitaper spectra and performed a parameterisation of the stop spectra using slope and moment measures. In comparison to traditional spectral estimations, multitaper is more exact and, more importantly, not limited to a stationary signal length necessary for the analysis window. Therefore, it is well-suited for the rather short duration of the burst of a stop. Results show that the burst characteristics vary with place of articulation. While the global spectral frequencies match the data in classical literature, it is shown that other spectral measures in our data do not follow the typical classical spectral patterns. It is discussed whether these differences are due to the use of different methodology, or substantial cross-linguistic differences in the spectral characteristics.

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Chudnovsky, A. A., E. Ben-Dor, and H. Saaroni. "Reflectance spectroscopy of indoor settled dust in Tel Aviv, Israel: comparison between the spring and the summer seasons." Advances in Geosciences 12 (July 4, 2007): 51–57. http://dx.doi.org/10.5194/adgeo-12-51-2007.

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Abstract. The influence of mineral and anthropogenic dust components on the VIS-NIR-SWIR spectral reflectance of artificial laboratory dust mixtures was evaluated and used in combination with Partial Least Squares (PLS) regression to construct a model that correlates the dust content with its reflectance. Small amounts of dust (0.018–0.33 mg/cm2) were collected using glass traps placed in different indoor environments in Tel Aviv, Israel during the spring and summer of 2005. The constructed model was applied to reflectance spectroscopy measurements derived from the field dust samples to assess their mineral content. Additionally, field samples were examined using Principal Component Analysis (PCA) to identify the most representative spectral pattern for each season. Across the visible range of spectra two main spectral shapes were observed, convex and concave, though spectra exhibiting hybrid shapes were also seen. Spectra derived from spring season dust samples were characterized mostly by a convex shape, which indicates a high mineral content. In contrast, the spectra generated from summer samples were characterized generally by a concave shape, which indicates a high organic matter content. In addition to this seasonal variation in spectral patterns, spectral differences were observed associated with the dwelling position in the city. Samples collected in the city center showed higher organic content, whereas samples taken from locations at the city margins, near the sea and next to open areas, exhibited higher mineral content. We conclude that mineral components originating in the outdoor environment influence indoor dust loads, even when considering relatively small amounts of indoor settled dust. The sensitive spectral-based method developed here has potentially many applications for environmental researchers and policy makers concerned with dust pollution.

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Devaux, M. F., P. Robert, A. Qannari, M. Safar, and E. Vigneau. "Canonical Correlation Analysis of Mid- and Near-Infrared Oil Spectra." Applied Spectroscopy 47, no. 7 (July 1993): 1024–29. http://dx.doi.org/10.1366/0003702934415435.

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A mathematical procedure based on Canonical Correlation Analysis (CCA) was used in order to assign the wavelengths of the near-infrared spectra through knowledge of the mid-infrared spectra. The relevance of the treatment was tested on commercial oils that mainly differ in their level of unsaturation. Initially, two separated Principal Component Analyses (PCAs) were performed on the near- and mid-infrared data to overcome the high intercorrelations across the wavelengths. CCA was then applied to the resulting principal components. Near- and mid-infrared canonical variates were assessed so that they achieved maximum correlation. The procedure makes it possible to draw CCA spectral patterns that exhibit significant positive and negative peaks. The first near-infrared canonical variate was highly correlated with the first mid-infrared canonical variate ( r2 = 0.97). The corresponding near- and mid-infrared CCA spectral patterns were therefore given the same interpretation. The mid-infrared pattern opposed negative peaks characteristic of CH2 groups to the positive peaks of CH3 and =CH groups. Consequently, in the near-infrared pattern, the positive peaks at 1708, 2140, 2170, and 2480 nm were assigned to CH3 or =CH groups, and the negative peaks at 2304, 2344, and 2445 nm were assigned to CH2 groups. A more precise interpretation was obtained by comparing the wavelengths observed to theoretical values and to previous assignments.

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LEWICKA, MARTA, and KEVIN ZUMBRUN. "SPECTRAL STABILITY CONDITIONS FOR SHOCK WAVE PATTERNS." Journal of Hyperbolic Differential Equations 04, no. 02 (June 2007): 181–96. http://dx.doi.org/10.1142/s0219891607001069.

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We compare inviscid stability conditions obtained by Lewicka for large-amplitude shock wave patterns with "slow eigenvalue", or low-frequency, stability conditions obtained by Lin and Schecter through a vanishing viscosity analysis of the Dafermos regularization. Under the structural condition that scattering coefficients for each component wave are positive, we show that BV and L1 inviscid stability are equivalent to respective versions of low-frequency Dafermos-regularized stability. When scattering coefficients appear with different signs, the conditions are in general distinct. We give various examples demonstrating this phenomenon and indicating the subtle role of cancellation in linearized behavior in the presence of negative scattering coefficients.

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González, P., J. Vijande, A. Valcarce, and H. Garcilazo. "Spectral patterns in the nonstrange-baryon spectrum." European Physical Journal A 29, no. 2 (August 2006): 235–44. http://dx.doi.org/10.1140/epja/i2006-10081-1.

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Georgiadis, Dimitrios, Frank Uhlmann, Alexander Schorch, Ralf W. Baumgartner, and David H. Evans. "Postembolic Spectral Patterns of Doppler Microembolic Signals." Cerebrovascular Diseases 16, no. 3 (2003): 253–56. http://dx.doi.org/10.1159/000071124.

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Elsner, Ludwig, and Charles R. Johnson. "Nonnegative matrices, zero patterns, and spectral inequalities." Linear Algebra and its Applications 120 (August 1989): 225–36. http://dx.doi.org/10.1016/0024-3795(89)90380-7.

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Zambon, G., H. E. Roman, and R. Benocci. "Vehicle Speed Recognition from Noise Spectral Patterns." International Journal of Environmental Research 11, no. 4 (July 13, 2017): 449–59. http://dx.doi.org/10.1007/s41742-017-0040-4.

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Dalezios, Yannis, Georgia G. Gregoriou, and Helen E. Savaki. "Metabolic Activity Patterns in the Monkey Visual Cortex as Revealed by Spectral Analysis." Journal of Cerebral Blood Flow & Metabolism 19, no. 4 (April 1999): 401–16. http://dx.doi.org/10.1097/00004647-199904000-00006.

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The metabolic activity pattern of the monkey visual cortex was mapped quantitatively with [14C]-2-deoxyglucose during the performance of a visually guided reaching task. After bandpass filtering of the reconstructed two-dimensional metabolic maps of areas V1 and V2, alternating bands of high and low metabolic activity were apparent in control and experimental hemispheres. The spatial arrangement of active bands was studied with two-dimensional spectral analysis, and bands were found to be more organized in the experimental monkey. In area V1 of the control monkey the spectral amplitude was spread over a wider range of directions and frequencies than in the experimental subject. The finding that layer IV is characterized by more complex spectra than layers I through III suggests the coexistence of more than one active columnar system in the geniculorecipient layer. In area V2, stripes running almost perpendicular to the V1/V2 border were found along with superimposed patches of enhanced metabolic activity. In the experimental hemispheres, the corresponding spectra were extremely sharp yielding a constant periodicity. It is suggested that the well-organized columnar arrangement within areas V1 and V2 of the experimental hemispheres emerges from the diffusely organized background network of activity patterns in the control state.

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Malik, Zvi, Chana Rothmann, Tova Cycowitz, Zwi J. Cycowitz, and Amos M. Cohen. "Spectral Morphometric Characterization of B-CLL Cells Versus Normal Small Lymphocytes." Journal of Histochemistry & Cytochemistry 46, no. 10 (October 1998): 1113–18. http://dx.doi.org/10.1177/002215549804601003.

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Spectral morphometric characterization of typical chronic lymphocytic leukemia (B-CLL) cells vs normal small lymphocytes stained by May-Grunwald-Giemsa was carried out by multipixel spectral imaging. The light intensity (450–850 nm of 104 pixels) from nuclear domains of each stained cell was recorded and represented as light transmittance spectra and optical density. Transmitted light spectra of two nuclear domains were determined, one with low-intensity light transmittance (LIT) and the other with high-intensity light transmittance (HIT). A spectral library was constructed using the four transmitted light spectra representing the HIT and LIT domains of the normal human lymphocytes and the LIT and HIT domains of the CLL cells. The spectral library served to scan CLL lymphocytes from 10 cases of CLL and the lymphocytes of 10 healthy individuals. Each spectrally similar domain in the nuclei of the lymphocytes was assigned an arbitrary color. The morphometric analysis of the spectrally classified nuclei showed specific spectral patterns for B-CLL in 92% of the cells. The specific spectral characteristics of each of the two cell populations were also observed by their optical density light absorbance spectra. We propose that spectral morphometric analysis may serve as an additional diagnostic tool for detection of CLL lymphocytes in a hematological specimen.

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Arrondo, José Luis R., Ibon Iloro, Julián Aguirre, and Félix M. Goñi. "A two‒dimensional IR spectroscopic (2D‒IR) simulation of protein conformational changes." Spectroscopy 18, no. 1 (2004): 49–58. http://dx.doi.org/10.1155/2004/406126.

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Two‒dimensional IR correlation spectroscopy (2D‒IR) is a novel method that provides the analysis of infrared spectra with the capacity to differentiate overlapping peaks and to distinguish between in‒phase and out‒of‒phase spectral responses. Artificial spectra originated from protein amide I band component parameters have been used to study their variation in the correlation maps. Using spectra composed of one, two or three Gaussian peaks, behaviour patterns of the bands in the synchronous and asynchronous maps have been originated, with changes in intensity, band position and bandwidth. Intensity changes produce high‒intensity spots in the synchronous spectra, whereas only noise is observed in the asynchronous spectra. Band shifting originates more complex patterns. In synchronous spectra, several spots are generated at the beginning and at the end of the shifting band. Also, characteristic asynchronous spectra with butterfly‒like shapes are formed showing the trajectory of the shift. Finally, synchronous maps corresponding to band broadening reveal several spots at peak inflection points, related to the zones with higher intensity variation. The asynchronous spectra are very complex but they follow a characteristic symmetric pattern. Furthermore, examples of maps obtained from polypeptides and proteins using temperature as the perturbing factor are interpreted in terms of the patterns obtained from artificial bands.

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Mahun, Andrii, Sabina Abbrent, Jiri Czernek, Jan Rohlicek, Hana Macková, Weihua Ning, Rafał Konefał, Jiří Brus, and Libor Kobera. "Reconstructing Reliable Powder Patterns from Spikelets (Q)CPMG NMR Spectra: Simplification of UWNMR Crystallography Analysis." Molecules 26, no. 19 (October 6, 2021): 6051. http://dx.doi.org/10.3390/molecules26196051.

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Spikelets NMR spectra are very popular as they enable the shortening of experimental time and give the possibility to obtain required NMR parameters for nuclei with ultrawide NMR patterns. Unfortunately, these resulted ssNMR spectra cannot be fitted directly in common software. For this reason, we developed UWNMRSpectralShape (USS) software which transforms spikelets NMR patterns into single continuous lines. Subsequently, these reconstructed spectral envelopes of the (Q)CPMG spikelets patterns can be loaded into common NMR software and automatically fitted, independently of experimental settings. This allows the quadrupole and chemical shift parameters to be accurately determined. Moreover, it makes fitting of spikelets NMR spectra exact, fast and straightforward.

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Kim, Chinpal, Sara Layman, Dorothy M. Morré, and D. James Morré. "Structural Changes Revealed by Fourier Transform Infrared and Circular Dichroism Spectroscopic Analyses Underlie tNOX Periodic Oscillations." Dose-Response 3, no. 3 (May 1, 2005): dose—response.0. http://dx.doi.org/10.2203/dose-response.003.03.008.

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A recurring pattern of spectral changes indicative of periodic changes in the proportion of β-structure and a-helix of a recombinant ECTO-NOX fusion protein of tNOX, with a cellulose binding domain peptide, was demonstrated by Fourier transform infrared (FTIR) and circular dichroism (CD) spectroscopic analyses. The pattern of structural changes correlated with oscillatory patterns of enzymatic activities exhibited by the protein previously interpreted as indicative of a clock function. The pattern consisted of a repeating pattern of oscillations with a period length of 21 min with five maxima (two separated by 5 min and 3 separated by 4 to 4.5 min) within each 21 min repeat. Oscillatory patterns were not obvious in comparable FTIR or CD spectra of albumin, ribonuclease or concanavalin A. The period length was constant at 5, 15, 25, 35 and 45° C (temperature compensated) and oscillations occurred independently of substrate presence. Spectra obtained in deuterium oxide yielded a longer period length of 26 min both for oscillations in enzymatic activity and absorbance ratios determined by FTIR. Taken together the findings suggest that the regular patterns of oscillations exhibited by the ECTO-NOX proteins are accompanied by recurrent global changes in the conformation of the protein backbone that directly modulate enzymatic activity.

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Kim, Chan-Jung. "Normalized spectral damage of a linear system over different spectral loading patterns." Mechanical Systems and Signal Processing 92 (August 2017): 30–38. http://dx.doi.org/10.1016/j.ymssp.2017.01.026.

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Wang, Cai-ling, Jinchang Ren, Hong-wei Wang, Yinyong Zhang, and Jia Wen. "Spectral-spatial classification of hyperspectral data using spectral-domain local binary patterns." Multimedia Tools and Applications 77, no. 22 (April 11, 2018): 29889–903. http://dx.doi.org/10.1007/s11042-018-5928-2.

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Jeanne Rampe, Meytij, Ignatius R. S. Santoso, Henny Lieke Rampe, Vistarani Arini Tiwow, and Anastasya Apita. "Infrared Spectra Patterns of Coconut Shell Charcoal as Result of Pyrolysis and Acid Activation Origin of Sulawesi, Indonesia." E3S Web of Conferences 328 (2021): 08008. http://dx.doi.org/10.1051/e3sconf/202132808008.

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Coconut is one of the industrial plants that plays an important role in the Indonesian economy. The part of coconut that has a high economic value is the coconut shell. This study aims to see the maximum temperature of the coconut shell pyrolysis reactor and to examine the spectrum pattern of charcoal purified using the activation of hydrochloric acid (HCl), acetic acid (CH3COOH), nitric acid (HNO3) and hot water (H2O). The process steps are pyrolysis process carried out at a temperature of ± 310 °C for 2 hours and activation using 4 types of solvents with different acidity levels, soaking for 12 hours. Infrared spectra pattern testing using Fourier Transform Infrared (FTIR). The results of the pyrolysis process produce charcoal, liquid smoke, tar and condensed gases. The spectral pattern of each purified charcoal was analyzed using Fourier Transform Infrared (FTIR). The results of the analysis showed that the spectral pattern of activated charcoal showed a spectral pattern with a low level of impurity absorption, namely the spectral pattern of charcoal using HCl activator at a concentration of 2 M.

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Dravins, Dainis, Hans-Günter Ludwig, and Bernd Freytag. "Spatially resolved spectroscopy across stellar surfaces." Astronomy & Astrophysics 649 (April 28, 2021): A17. http://dx.doi.org/10.1051/0004-6361/202039997.

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Context. High-precision stellar analyses require hydrodynamic 3D modeling. Testing such models is feasible by retrieving spectral line shapes across stellar disks, using differential spectroscopy during exoplanet transits. Observations were presented in Papers I, II, and III, while Paper IV explored synthetic data at hyper-high spectral resolution for different classes of stars, identifying characteristic patterns for Fe I and Fe II lines. Aims. Anticipating future observations, the observability of patterns among photospheric lines of different strength, excitation potential and ionization level are examined from synthetic spectra, as observed at ordinary spectral resolutions and at different levels of noise. Time variability in 3D atmospheres induces changes in spectral-line parameters, some of which are correlated. An adequate calibration could identify proxies for the jitter in apparent radial velocity to enable adjustments to actual stellar radial motion. Methods. We used spectral-line patterns identified in synthetic spectra at hyper-high resolution in Paper IV from 3D models spanning Teff = 3964–6726 K (spectral types ~K8 V–F3 V) to simulate practically observable signals at different stellar disk positions at various lower spectral resolutions, down to λ/Δλ = 75 000. We also examined the center-to-limb temporal variability. Results. Recovery of spatially resolved line profiles with fitted widths and depths is shown for various noise levels, with gradual degradation at successively lower spectral resolutions. Signals during exoplanet transit are simulated. In addition to Rossiter-McLaughlin type signatures in apparent radial velocity, analogous effects are shown for line depths and widths. In a solar model, temporal variability in line profiles and apparent radial velocity shows correlations between jittering in apparent radial velocity and fluctuations in line depth. Conclusions. Spatially resolved spectroscopy using exoplanet transits is feasible for main-sequence stars. Overall line parameters of width, depth and wavelength position can be retrieved already with moderate efforts, but a very good signal-to-noise ratio is required to reveal the more subtle signatures between subgroups of spectral lines, where finer details of atmospheric structure are encoded. Fluctuations in line depth correlate with those in wavelength, and because both can be measured from the ground, searches for low-mass exoplanets should explore these to adjust apparent radial velocities to actual stellar motion.

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Wang, Yanghua. "Reservoir characterization based on seismic spectral variations." GEOPHYSICS 77, no. 6 (November 1, 2012): M89—M95. http://dx.doi.org/10.1190/geo2011-0323.1.

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The seismic frequency spectrum provides a useful source of information for reservoir characterization. For a seismic profile presented in the time-space domain, a vector of the frequency spectrum can be generated at every sampling point. Because the spectrum vectors at different time-space locations have different variation features, I attempt for the first time to exploit the variation pattern of the frequency spectrum for reservoir characterization, and test this innovative technology in prediction of coalbed methane (CBM) reservoirs. The prediction process implicitly takes account of the CBM reservoir factors (such as viscosity, elasticity, cleat system, wave interference within a coal seam, etc.) that affect the frequency spectrum, but strong amplitudes in seismic reflections do not necessarily show any influence in clustering analysis of spectral variation patterns. By calibrating these variation patterns quantitatively with CBM productions in well locations, we are able to characterize the spatial distribution of potential reservoirs.

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de Rijk, Björn. "Spectra and Stability of Spatially Periodic Pulse Patterns II: The Critical Spectral Curve." SIAM Journal on Mathematical Analysis 50, no. 2 (January 2018): 1958–2019. http://dx.doi.org/10.1137/17m1127594.

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Magnuson, Matthew L., James H. Owens, and Catherine A. Kelty. "Characterization of Cryptosporidium parvum by Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry." Applied and Environmental Microbiology 66, no. 11 (November 1, 2000): 4720–24. http://dx.doi.org/10.1128/aem.66.11.4720-4724.2000.

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ABSTRACT Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) was used to investigate whole and freeze-thawed Cryptosporidium parvum oocysts. Whole oocysts revealed some mass spectral features. Reproducible patterns of spectral markers and increased sensitivity were obtained after the oocysts were lysed with a freeze-thaw procedure. Spectral-marker patterns forC. parvum were distinguishable from those obtained forCryptosporidium muris. One spectral marker appears specific for the genus, while others appear specific at the species level. Three different C. parvum lots were investigated, and similar spectral markers were observed in each. Disinfection of the oocysts reduced and/or eliminated the patterns of spectral markers.

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Chechetkin, V. R., and V. V. Lobzin. "Detection of Large-Scale Noisy Multi-Periodic Patterns with Discrete Double Fourier Transform." Fluctuation and Noise Letters 19, no. 02 (November 20, 2019): 2050019. http://dx.doi.org/10.1142/s0219477520500194.

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In many processes, the variations in underlying characteristics can be approximated by noisy multi-periodic patterns. If large-scale patterns are superimposed by a noise with long-range correlations, the detection of multi-periodic patterns becomes especially challenging. To solve this problem, we developed a discrete double Fourier transform (DDFT). DDFT is based on the equidistance property of harmonics generated by multi-periodic patterns in the discrete Fourier transform (DFT) spectra. As the large-scale patterns generate long enough equidistant series, they can be detected by the iteration of the primary DFT. DDFT is defined as Fourier transform of intensity spectral harmonics or of their functions. It comprises widely used cepstrum transform as a particular case. We present also the relevant analytical criteria for the assessment of the statistical significance of peak harmonics in DDFT spectra in the presence of noise. DDFT technique was tested by extensive numerical simulations. The practical applications of the DDFT technique are illustrated by the analysis of variations in solar wind speed related to solar rotation and by the study of large-scale multi-periodic patterns in DNA sequences. The latter application can be considered as a generic example for the general spectral analysis of symbolic sequences. The results are compared with those obtained by the cepstrum transform. The mutual combination of DFT and DDFT provides an efficient technique to search for noisy large-scale multi-periodic patterns.

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Klimasara, A. J., and T. L. Barry. "Automated Quantitative XRF Analysis of Soda-Lime Glass Utilizing Pattern Recognition." Advances in X-ray Analysis 30 (1986): 325–32. http://dx.doi.org/10.1154/s0376030800021455.

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AbstractA set of programs in Fortran 77 has been written to automate quantitative analysis on the Rigaku SMAX/PDP-11/73 XRF System. The spectrometer can be instructed and Trained to recognize spectral patterns of soda-lime glass or other materials.The method of pattern recognition employed is based on the relative position of spectra-vectors in N-Dimension Euclidean feature space. The distance between 2 vector-points: is used as a classifier.The software correlates between 2 Euclidean feature spaces:- Spectra Feature-Space- Chemistry Feature-SpaceQuantitative results are extracted automatically and printed in laboratory report form. Mathematical modeling with associated software and the results obtained are presented.

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Journal articles on the topic 'Spectral Patterns'

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