Spectral Measure Research Papers - Academia.edu (original) (raw)

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- Modeling, Algorithm, Signal Analysis, Impulse response

Consider the random ordinary differential equation in '@

- by Marc Corluy
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- Stochastic Process, Statistics, Multivariate Analysis, Correlation coefficient

The paper presents the application of non−modulation reflectance method for composition profiling of epitaxial Al x Ga 1-x As/GaAs structures. This non−destructive method is based on spectral measurements and theoretical reflectance spectrum matching. This is a very accurate and sensitive method of determining the Al composition in Al x Ga 1-x As layers and structures with resolution down to 1 nm. In this work, the authors describe theoretic principles of this method and present ex− perimental results of characterization of different AlGaAs structures to prove the potential of the worked out method.

The .carcity of .uitabZe radio qectrvm for indoor Ndio communicatio~ under tM 'regulatory co~trAinu Au prompted endeavor. to inve.tigate mean. of utilizing tM vcduable channel bandwidtA. aVAilable tDitlr.in _ thue condrAinu. The interference potential of the mi-cro1Uave oven u chaNCterUed in an attem.pt to render the ISM band it Oc.cupied weful for indoor radio com-municatio~. The chaNCterUation procu. included an in-depth power qectral metuu'rement of the rtldiation. .A theoretical model of the radiation clr.aNCteridic. u _ tMn propo.ed. The interference clr.aNCterizGtion re-nUt. point to a po"ible valuable frequency bandwidth t/ud may be available for high Ipeed indoor communic~ tion. wage in the "low cod-connmer product a'renG.

- by jonathon cheah
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- Computer Science, Microwave Communication, High Speed, Spectrum

3 and I independently started working on 3D LUTS as an alternative to algebraic formulae to position spectral measurements in an isotropic color space. We both chose Newhall, Nickerson and Judd's data for Munsell chips as the data for our Look Up Tables(LUT). We used the colori- metric description of each Munsell Chip at the position speci- fied by Munsell

- by John J . McCann
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- Look up Table, Chip, Color Space, Spectral Measure

In this paper, a comparison is made through evaluating the withinand between-class species variability for the original, the first derivative and second derivative spectra. For each, the experiment was conducted (i) over the entire electromagnetic spectrum (EMS), (ii) the visible (VIS) region, (iii) the near infrared (NIR) region, (iv) the short wave infrared (SWIR) region, (v) using band selection, for example, best 10, 20, 30 and 65 bands selected, through linear stepwise discriminant analysis (vi) using sequential selection of bands, for example, every 5th, 9th, 15th, 19th or 25th band selected and (vii) spectral degradation of the spectral bands by averaging the reflectance values for every 5th, 9th, 15th, 19th or 25th band. We concluded that for this data set, there are important bands from the original spectra, the first and second derivative spectra and from various regions of the EMS (VIS, NIR, SWIR) that is important for species separability. Furthermore, there did not seem to be any decrease in species separability, for this data set, by degrading the spectral bands through averaging the reflectance. This implies that hyperspectral (high spectral) measurements did not prove useful in species separability compared to lower spectral resolution data.

- by Pravesh Debba
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- Remote Sensing, Near Infrared, Geoscience and remote sensing, Image Classification

Purpose Many researchers have studied the acoustics, physiology, and perceptual characteristics of the voice source, but despite significant attention, it remains unclear which aspects of the source should be quantified and how measurements should be made. In this study, the authors examined the relationships among a number of existing measures of the glottal source spectrum, along with the association of these measures to overall spectral shapes and to glottal pulse shapes, to determine which measures of the source best capture information about the shapes of glottal pulses and glottal source spectra. Method Seventy-eight different measures of source spectral shapes were made on the voices of 70 speakers. Principal components analysis was applied to measurement data, and the resulting factors were compared with factors similarly derived from oral speech spectra and glottal pulses. Results Results revealed high levels of duplication and overlap among existing measures of source spec...

- by Bruce Gerratt
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- Physiology, Cognitive Science, Acoustics, Phonology

A flat-field grating XUV spectrograph has been set up for laser plasma interaction studies. It uses a variable groove-spacing concave grating !n grazing incidence geometry and operates in the wavelength range of 25-290 A. A brief description of the design principle, construction and operation is given. Variation of spectral resolution with respect to the position of detector plane is studied. A resolution of 0.2 A (at A = 35.0,~) observed from the emission spectrum of carbon plasma is in agreement with that expected from design considerations. The instrument facilitates recording of multiple spectra on a single film and can be coupled to a microchannel plate-CCD camera detection system for on-line monitoring and processing of the spectrum, and to an X-ray streak camera for temporally resolved spectral measurements.

- by Prasad Naik
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- Engineering, Laser produced plasma, X Rays, Spectrum

Consistency issues related to autocorrelation estimation for Gaussian processes with mixed spectra are clarified. The sample autocorrelation is known not to be consistent when the spectrum contains spectral atoms. This fact is verified by computing explicitly its mean-square limit in terms of the random measure assigned to the atoms of the process. The alternative estimator constructed from the zero-crossing rate is likewise not consistent in general. However, it is consistent for a spectrum supported at a single frequency, or a spectrum for which the 'signal' and 'noise' have the exact same first-order autocorrelation. This is proved, using recent results from multiple Wiener-It8 integral expansions for level-crossing counts, by direct computation of the spectrum of the zero-crossing indicator process when the underlying process has a mixed spectrum. In general, regardless of the spectral type, the asymptotic zero-crossing rate admits values between the lowest and highest positive frequencies with probability one. For band-limited processes, this fact provides an easy way to assess the precision of functions of the zero-crossing rate.

- by Benjamin Kedem
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- Statistics, Filter, First-Order Logic, Spectrum
- by Manuel Gadella
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- Pure Mathematics, Eigenvectors, Hilbert Space, Spectral Measure

Visible/near-infrared spectroscopy (Vis/NIRS) appears as a prominent technique for non-destructive fruit quality assessment. This research work was focused in to evaluate the use of Vis/NIRS in measuring the quality characteristics of intact Satsuma mandarin ''Zaojin Jiaogan'' (C. reticulata), and to establish the relationship between non-destructive Vis/NIR spectral measurements and the major physiological properties of fruit (firmness, soluble solids content (SSC) and acidity (pH)). Before calibration, two types of data pre-processing were used and NIR models were developed based on partial least square (PLS) and principal component regression (PCR) techniques. The prediction models indicated that a reasonable to excellent prediction performance could be expected for each property. The best SSC model had a mean square error of prediction (RMSEP) of 0.33°Brix and correlation coefficient between predicted and measured values (r) of 0.94, the proposed model for the pH and the compression force had a RMSEP of 0.18 and 8.53, as well as, r of 0.8 and 0.83, respectively. It was concluded that by using the Vis/NIRS measurement technique, in the full spectral range (400-2350 nm), it is possible to assess the quality characteristics of mandarin.

- by Annia García Pereira
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- Food Engineering, Near Infrared Spectroscopy, Mandarin, NIR spectroscopy
- by Mar Sorribas
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- Atmospheric Aerosols, Multidisciplinary, Uv Radiation, Optical Properties

In this paper we describe the use of thermo-activated PNIPAM nano-material in optical switching devices. In other publications, the PNIPAM is used either as a carrier for crystalline colloidal array self-assemblies or as micro-particles that serve as pigment bags. In this publication we use a simpler-to-fabricate pure PNIPAM solution in a semi-dilute regime. The PNIPAM devices produced are transparent at

- by solon mias
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- Self Assembly, Nanotechnology, Optical Switch, Optical switching

1,3-Di-alkyl-2-(arylazo)imidazolium iodide (RaaiR 0þ 2 I À) has been used to prepare iodocuprate(I) and iodoargentate(I) complexes. The structural confirmation has been carried out by single crystal X-ray diffraction study in representative cases. Iodo bridged anion, [Cu 2 (l-I) 2 I 2 ] 2À , serves as charge support to dialkylazoimidazolium ion (RaaiR 0þ 2). Silver(I) compound is a trimeric iodo-bridged [Ag 3 I 5 ] 2À that forms 1D chain while imidazolium ion, RaaiR 0þ 2 , is penetrating into the network. Electrostatic interaction between organic cation and inorganic anion and supramolecular interactions viz. hydrogen bonding, D-H-p, p-p interactions contribute to the crystal packing.

- by MAYA Mustak
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- Chemistry, Inorganic Chemistry, Hydrogen Bond, X ray diffraction

The underground water system of Mecsek Hill, Hungary was studied using spectrofluorometry. A quantitative dye-tracing technique was used to map the connections between ground water recharge points and the springs and wells. Excitation-emission matrices were used to establish optimal spectroscopic parameters for spectral measurements. Only an EEM gives full spectrofluorimetric information about the sample and makes possible the determination of the optimal wavelength parameters. The uranine concentration was determined by measuring the synchronous excitation spectra of water samples. It was found that under the 4 μg/L uranine concentration, no special chemical treatment was necessary if the pH values remained between 7 and 8. However, above this concentration, the solution should be diluted to avoid spectral distortion from the increasing absorbance of the sample. Long-term concentration measurements were conducted based on spectrofluorometry.

- by Paal Gabor
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- Geology, Chemistry, Medicine, Water Supply

This longitudinal study gathered data with regard to the question: Does singing training have an effect on the speaking voice? Fourteen voice majors (12 females and two males; age range 17 to 20 years) were recorded once a semester for four consecutive semesters, while sustaining vowels and reading the "Rainbow Passage." Acoustic measures included speaking fundamental frequency (SFF) and sound pressure level (SLP). Perturbation measures included jitter, shimmer, and harmonic-to-noise ratio. Temporal measures included sentence, consonant, and diphthong durations. Results revealed that, as the number of semesters increased, the SFF increased while jitter and shimmer slightly decreased. Repeated measure analysis, however, indicated that none of the acoustic, temporal, or perturbation differences were statistically significant. These results confirm earlier cross-sectional studies that compared singers with nonsingers, in that singing training mostly affects the singing voice and rarely the speaking voice.

- by Howard Rothman
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- Acoustics, Speech perception, Speech Acoustics, Adolescent

Shortwave infrared reflectance (SWIR) spectra obtained from a Portable Infrared Mineral Analyser (PIMA) were applied to map acidic mine soils at San Miguel massive sulphide deposit, Iberian Pyrite Belt, Spain. Field spectral measurements and laboratory analysis were performed on samples from 58 stations from two very polluted grounds. These analyses identified secondary and tertiary Fe-rich sulphate-hydrate minerals associated with the alteration of sulphide-bearing mine wastes and other associated infrared active minerals. The spectral absorption features for the pure salt types found in these areas allowed the preparation of a specific reference library for automatic mineral identification. Using this approach three separate zones around the sources of contamination have been discriminated: a bproximalQ zone dominated by rozenite + hexahydrite, a btransitionalQ zone dominated by copiapite + coquimbite and a bdistalQ zone of hydronium-jarosite. An additional zone of bgypsumQ was also recognized locally at the areas, where, last decade the neutralization of the acid soils with limestones was attempted. In addition to discriminating distinct mineralogical zones quantitative spectral data allowed contoured mineral maps to be produced that are comparable with the estimated mineralogical data obtained from conventional methods, such as XRD and field observations. These maps demonstrate that sulphate minerals were firstly formed by oxidation of the pyrite-rich ores followed by dissolution and precipitation involving a combination of oxidation, dehydration, and neutralization reactions. The study shows the potential of SWIR spectral analysis to identify and understand the distribution of efflorescent salts and other products of pyrite decomposition and provides a methodology to assist the research and monitoring of sources of environmental contamination.

- by Ana Alvaro
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- Geology, Geochemistry, Infrared spectroscopy, Spectral analysis

In this paper, we study the harmonic analysis of Bernoulli measures. We show a variety of orthonormal Fourier bases for the L^2 Hilbert spaces corresponding to certain Bernoulli measures, making use of contractive transfer operators. For... more

- by Palle Jorgensen
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- Mathematics, Applied Mathematics, Harmonic Analysis, Pure Mathematics

We examine two questions regarding Fourier frequencies for a class of iterated function systems (IFS). These are iteration limits arising from a fixed finite families of affine and contractive mappings in ^d, and the "IFS" refers to such a finite system of transformations, or functions. The iteration limits are pairs (X, μ) where X is a compact subset of ^d, (the support of μ) and the measure μ is a probability measure determined uniquely by the initial IFS mappings, and a certain strong invariance axiom. The two questions we study are: (1) existence of an orthogonal Fourier basis in the Hilbert space L^2(X,μ); and (2) the interplay between the geometry of (X, μ) on the one side, and the spectral data entailed by possible Fourier bases.

- by Palle Jorgensen
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- Functional Analysis, Attractor Theory, Pure Mathematics, Spectral Theory

In this paper, we give a more direct proof of the results by Clair and Mokhtari-Sharghi [7] on the zeta functions of periodic graphs. In particular, using appropriate operator-algebraic techniques, we establish a determinant formula in this context and examine its consequences for the Ihara zeta function. Moreover, we answer in the affirmative one of the questions raised in [12] by Grigorchuk andŻuk. Accordingly, we show that the zeta function of a periodic graph with an amenable group action is the limit of the zeta functions of a suitable sequence of finite subgraphs.

- by Daniele Guido
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- Mathematics, Algebraic Geometry, Functional Analysis, Pure Mathematics

Recently, it was demonstrated that ␥-cyclodextrins (␥-CDs) greatly accelerates transfer of hydrophobic pyrenelabeled and other fluorescent phospholipid derivatives from vesicles to cells in culture (Tanhuanpä ä and Somerharju, 1999). To understand better the characteristics of this process, we studied the interaction of ␥-CD with pyrene-labeled phosphatidylcholines (PyrPCs) using a variety of physical methods. Either one or both of the acyl chains of PC was labeled with a pyrene moiety (monoPyrPCs and diPyrPCs, respectively), and the length of the labeled chain(s) varied from 4 to 14 carbons. Fluorescent binding assays showed that the association constant decreases strongly with increasing acyl chain length. PyrPC/␥-CD stoichiometry was 1:2 for the shorter chain species, but changed to 1:3 when the acyl chain length exceeded 8 (diPyrPCs) or 10 (monoPyrPCs) carbons. The activation energy for the formation of diPyr 10 PC/␥-CD complex was high, i.e., ϩ92 kJ/mol, indicating that the phospholipid molecule has to fully emerge from the bilayer before complex formation can take place. The free energy, enthalpy, and entropy of transfer of monoPyrPC from bilayer to ␥-CD complex were close to zero. The absorption, Fourier transform infrared, and fluorescence spectral measurements and lifetime analysis indicated that the pyrene moiety lies inside the CD cavity and is conformationally restricted, particularly when the labeled chain is short. The acyl chains of a PyrPC molecule seem to share a CD cavity rather than occupy different ones. The present data provide strong evidence that the ability of ␥-CD to enhance intermembrane transfer of pyrene-labeled phospholipids is based on the formation of stoichiometric complexes in the aqueous phase. This information should help in designing CD derivatives that are more efficient lipid carriers then those available at present.

- by Kwan Cheng
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- Kinetics, Fluorescent Dyes and Reagents, Biophysical Chemistry, Biological Sciences

Hyperspectral imaging technique is an upcoming and promising field of research for non- destructive quality assessment of agricultural and food products. It has a greater advantage of combining spatial imaging and spectral measurement which can detect both of the external and internal quality of the product. Sugar content is an important internal quality attribute for any fresh fruit. This research

- by Sumpun Chaitep
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- Quality assessment, Quality Attributes, Prediction Model, Correlation coefficient

The optical degradation induced by long-term (about 15 years) field exposure on c-Si photovoltaic modules belonging to the large-scale Delphos ENEA PV plant, located in Manfredonia (South of Italy), was investigated by making comparative reflectance measurements on the exposed modules, after their dismounting and cleaning, and on the original, unexposed counterparts. Four types of module fabrication technologies were analyzed: Helios

- by Antonio Parretta
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- Engineering, Physical sciences, Applied Optics, CHEMICAL SCIENCES

We introduce a duality for Affine Iterated Function Systems (AIFS) which is naturally motivated by group duality in the context of traditional harmonic analysis. Our affine systems yield fractals defined by iteration of contractive affine mappings. We build a duality for such systems by scaling in two directions: fractals in the small by contractive iterations, and fractals in the large by recursion involving iteration of an expansive matrix. By a fractal in the small we mean a compact attractor X supporting Hutchinson's canonical measure mu, and we ask when mu is a spectral measure, i.e., when the Hilbert space L^2(mu) has an orthonormal basis (ONB) of exponentials. We further introduce a Fourier duality using a matched pair of such affine systems. Using next certain extreme cycles, and positive powers of the expansive matrix we build fractals in the large which are modeled on lacunary Fourier series and which serve as spectra for X. Our two main results offer simple geometric ...

- by Palle Jorgensen
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- Mathematics, Harmonic Analysis, Pure Mathematics, Spectrum

We consider Jacobi matrices with zero diagonal and off-diagonals given by elements of the hull of the Fibonacci sequence and show that the spectrum has zero Lebesgue measure and all spectral measures are purely singular continuous. In addition, if the two hopping parameters are distinct but sufficiently close to each other, we show that the spectrum is a dynamically defined Cantor set, which has a variety of consequences for its local and global fractal dimension.

- by Anton Gorodetski
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- Mathematics, Spectral Theory, Lebesgue measure, Spectrum

Let (G,c) be an infinite network, and let E be the canonical energy form. Let Δ_2 be the Laplace operator with dense domain in ℓ^2(G) and let Δ_E be the Laplace operator with dense domain in the Hilbert space H_E of finite energy functions on G. It is known that Δ_2 is essentially self-adjoint, but that Δ_E is not. In this paper, we characterize the Friedrichs extension of Δ_E in terms of Δ_2 and show that the spectral measures of the two operators are mutually absolutely continuous with Radon-Nikodym derivative λ (the spectral parameter), in the complement of λ=0. We also give applications to the effective resistance on (G,c). For transient networks, the Dirac measure at λ = 0 contributes to the spectral resolution of the Friedrichs extension of Δ_E but not to that of the self-adjoint ℓ^2 Laplacian.

- by Palle Jorgensen
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- Functional Analysis, Spectral Theory, Hilbert Space, Laplace operator

A new series of hexacoordinate cobalt(II), nickel(II) and copper(II) complexes of 5-(2-carboxyphenylazo)-2thiohydantoin HL having formulae [LM(OAc)(H 2 O) 2 ] AE nH 2 O (M ¼ Co II , Cu II and Ni II), [LM¢Cl(H 2 O) 2 ] AE nH 2 O (M¢ ¼ Co II and Ni II), [LCuCl(H 2 O)] 2 AE 2H 2 O, [LCu(H 2 O) 3 ](ClO 4) and [LCu(HSO 4)(H 2 O) 2 ] were isolated and characterized by elemental analyses, molar conductivities and magnetic susceptibilities, and by i.r., electronic and e.s.r. spectral measurements, as well as by thermal (t.g. and d.t.g.) analyses. The i.r. spectra indicate that the ligand HL behaves as a monobasic tridentate towards the three divalent metal ions via an azo-N, carboxylate-O and thiohydantoin-O atom. The magnetic moments and electronic spectral data suggest an octahedral geometry for Co II complexes, distorted octahedral geometry for both Ni II and Cu II complexes with a dimeric structure for [LCuCl(H 2 O)] 2 AE 2H 2 O through bridged chloro ligands. The X-band e.s.r. spectra reveal an axial symmetry for the copper(II) complexes with unsymmetrical DM s ¼ ±1 signal and G-parameter less than four for the dimeric [LCuCl(H 2 O)] 2 AE 2H 2 O. The thermogravimetry (t.g. and d.t.g.) of some complexes were studied; the order and kinetic parameters of their thermal degradation were determined by applying Coats-Redfern method and discussed.

- by Eman Bakr
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- Chemistry, Inorganic Chemistry, Copper, Magnetic Susceptibility

The authors are solely responsible for the content of this technical presentation. The technical presentation does not necessarily reflect the official position of the American Society of Agricultural and Biological Engineers (ASABE), and its printing and distribution does not constitute an endorsement of views which may be expressed. Technical presentations are not subject to the formal peer review process by ASABE editorial committees; therefore, they are not to be presented as refereed publications. Citation of this work should state that it is from an ASABE meeting paper. EXAMPLE: Author's Last Name, Initials. 2006. Title of Presentation. ASABE Paper No. 06xxxx. St. Joseph, Mich.: ASABE. For information about securing permission to reprint or reproduce a technical presentation, please contact ASABE at

- by iSMAiL BOGREKCi
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- Raman Spectroscopy, Phosphorus, Spectrum, Particle Size

Measurements of global spectral irradiance in the UV and visible range were carried out during December 1995 and January 1996 in Townsville, Australia (19.33øS, 146.76øE, 30 m above sea level (asl)) using the mobile spectroradiometer of the Fraunhofer Institute for Atmospheric Environmental Research, Germany. These are, to our knowledge, the first reported spectral UV measurements in the tropics of Australia. For cloudless days, the spectral measurements are consistent with results of a radiative transfer model. In the UVA, measurement and model agree within 4-10% for solar elevations above 10 ø. In the UVB, the differences are larger (•15% at 300 nm), which can be explained by uncertainties in the model input parameters of total ozone column and ozone absorption cross section. The variation of the daily erythemal irradiation was found to be :k24% (:k i or) for the period of the campaign. The variation of the total ozone column contributes less than :k3% to this variability; the main part is introduced by clouds. These attenuate UV irradiation less than total irradiation (300 nm-3000 nm); the daily total irradiation averaged over the period of the campaign was reduced by a factor of 0.71 owing to cloudiness compared to the clear-sky case while the erythemal irradiation was only diminished by a factor of 0.78. Using long-term records of total irradiation and ozone column, the parameters influencing UV radiation on Earth were found to be typical for the period and site of the campaign. The maximum erythemally weighted irradiance measured during the campaign was 429 mW/m •, and the average daily erythemal irradiation for this period was 6.06 kJ/m •. These high radiation levels were found to exceed the corresponding values for Garmisch-Partenkirchen (47.5øN, 11.0øE, 730 m asl), Germany, by between 55 and 70%. This pronounced difference in the radiation environment between Australia and Germany is explained by the higher solar elevation and the lower ozone column in the tropics. getting skin cancer [$chaart et al., 1993]. An Australia wide survey in 1990 estimated an age-standardized incidence rate for nonmelanoma skin cancer (NMSC) of 977 per 100,000 inhabitants, which documents an in

- by G. Bernhard
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- Multidisciplinary, Uv Radiation, Ozone, Cross Section
- by Manuel Gadella
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- Applied Mathematics, Hilbert Space, Spectral Measure

Carotenes Xanthophyll pigments Anthocyanin pigments Absorption features Spectral measures of pigments Spectroscopy Life on Earth depends on photosynthesis. Photosynthetic systems evolved early in Earth history and have been stable for 2.5 billion years, providing prima facie evidence for the significance of pigments in plant functions. Photosynthetic pigments fill multiple roles from increasing the range of energy captured for photosynthesis to protective functions. Given the importance of pigments to leaf functioning, greater effort is needed to determine whether individual pigments can be identified and quantified in vivo using high fidelity spectroscopy. We review recent advances in detecting plant pigments at the leaf level and discuss successes and reasons why challenges remain for robust remote observation and quantification. New methods to identify and quantify individual pigments in the presence of overlapping absorption features would provide a major advance in understanding their biological functions, quantifying net carbon exchange, and identifying plant stresses.

- by John Gamon
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- Remote Sensing, Photosynthesis, Energy, Spectroscopy

This paper describes the Glory Mission Aerosol Polarimetry Sensor (APS) being built by Raytheon under contract to NASA's Goddard Space Flight Center. Scheduled for launch in late 2008, the instrument is part of the US Climate Change Research Initiative to determine the global distribution of aerosols and clouds with sufficient accuracy and coverage to establish the aerosol effects on global climate change as well as begin a precise long-term aerosol record. The Glory APS is a polarimeter with nine solar reflectance spectral bands that measure the first three Stokes parameters vector components for a total of 27 unique measurements. In order to improve the reliability and accuracy of the measurements, additional 9 redundant measurements are made, yielding a total of 36 channels. The sensor is designed to acquire spatial, temporal, and spectral measurements simultaneously to minimize instrumental effects and provide extremely accurate Raw Data Records. The APS scans in the direction close to of the spacecraft velocity vector in order to acquire multi-angle samples for each retrieval location so that the Stokes parameters can be measured as functions of view angle.

- by Carl Nardell
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- Engineering, Geography, Climate Change, Polarimetry
- by Daniel Végh
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- Materials Engineering, Condensed Matter Physics, Fluorescence, Conducting Polymers

Let (G, c) be an infinite network, and let E be the canonical energy form. Let ∆ 2 be the Laplace operator with dense domain in ℓ 2 (G) and let ∆ E be the Laplace operator with dense domain in the Hilbert space H E of finite energy functions on G. It is known that ∆ 2 is essentially self-adjoint, but that ∆ E is not. In this paper, we characterize the Friedrichs extension of ∆ E in terms of ∆ 2 and show that the spectral measures of the two operators are mutually absolutely continuous with Radon-Nikodym derivative λ (the spectral parameter), in the complement of λ = 0. We also give applications to the effective resistance on (G, c). For transient networks, the Dirac measure at λ = 0 contributes to the spectral resolution of the Friedrichs extension of ∆ E but not to that of the self-adjoint ℓ 2 Laplacian.

- by Palle Jorgensen
- •
- Functional Analysis, Spectral Theory, Hilbert Space, Laplace operator

Measurements of a signal's spectral content using narrow-band filters and heterodyne techniques are still widely used for component testing for magnetic recording. Most of these measurements use simple square-wave patterns. In contrast, maximal-length pseudorandom bit sequences (PRBS) are in many ways ideal patterns for characterizing magnetic recording channels. Almost all the important characteristics of a recording channel can be obtained from measurements of the PRBS spectrum and the associated noise spectrum, without reference to the actual readback waveforms. These include estimates of the signal amplitude, resolution, nonlinear distortion, transition noise, signal-to-noise ratio, and error rates.

- by roger wood
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- Engineering, Magnetic Recording, Physical sciences, Bit Error Rate
- by Despina Hatzidimitriou
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- Atmospheric Science, Seasonality, Atmospheric sciences, Optical Properties
- by Qimin Yan
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- Engineering, Physics, III-V Semiconductors, Applied Physics

We are concerned with an harmonic analysis in Hilbert spaces L²(µ), where µ is a probability measure on R n. The unifying question is the presence of families of orthogonal (complex) exponentials eλ(x) = exp(2πiλx) in L²(µ). This question in turn is connected to the existence of a natural embedding of L²(µ) into an L²-space of Bohr almost periodic functions on R n. In particular we explore when L²(µ) contains an orthogonal basis of eλ functions, for λ in a suitable discrete subset in R n; i.e, when the measure µ is spectral. We give a new characterization of finite spectral sets in terms of the existence of a group of local translation. We also consider measures µ that arise as fixed points (in the sense of Hutchinson) of iterated function systems (IFSs), and we specialize to the case when the function system in the IFS consists of affine and contractive mappings in R n. We show in this case that if µ is then assumed spectral then its partitions induced by the IFS at hand have zero ...

- by Palle Jorgensen
- •
- Mathematics, Functional Analysis, Harmonic Analysis, Pure Mathematics

Non-destructive stress diagnostics is essential to optimise variable nutrient application with a minimal environmental load. The identifying characteristics when spectrally determining nitrogen, phosphorous and potassium stress in a canopy are dominantly nonspecific symptoms expressed as varying levels of chlorophyll in the leaves. The challenge is spectrally based discrimination between N, P and K stress. This paper introduces a methodology able to discriminate between N, P and K stress symptoms utilising both the spectral and spatial dimension simultaneously. The methodology was tested on spring barley grown under controlled conditions. The spectral range used was 450-1000 nm. Nine spectral measurement were carried out on each plant. The measuring points were spatially located at The authors are solely responsible for the content of this technical presentation. The technical presentation does not necessarily reflect the official position of the American Society of Agricultural Engineers (ASAE), and its printing and distribution does not constitute an endorsement of views which may be expressed. Technical presentations are not subject to the formal peer review process by ASAE editorial committees; therefore, they are not to be presented as refereed publications. Citation of this work should state that it is from an ASAE meeting paper EXAMPLE: Author's Last Name, Initials. 2003. Title of Presentation. ASAE Paper No. 03xxxx. St. Joseph, Mich.: ASAE. For information about securing permission to reprint or reproduce a technical presentation, please contact ASAE at hq@asae.org or 269-429-0300 (2950 Niles Road, St. Joseph, MI 49085-9659 USA). the tip, middle and base of the three last fully developed leaves. This design generated a fourdimensional data set consisting of the specific plant, the spectral dimension, the plant leaf position, and position on the leaf. Sequential mutiway Partial Least Squares Regression model (N-PLS) analysis with dummy variables was able to correctly classify the four nutrient conditions with 92% accuracy regardless of the respective growth stages within a time window of two weeks. Thus inclusion of the spatial dimension to the spectral dimension was shown to be a promissing nutrient diagnostic tool.

- by Rasmus Jørgensen
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- Chemistry, Nitrogen, Potassium, Spring Barley

The southwest lagoon of New Caledonia is a wide semi-open coral reef lagoon bounded by an intertidal barrier reef and bisected by numerous deep inlets. This paper synthesizes findings from the 2000-2008 French National Program EC2CO-PNEC relative to the circulation and the transport of suspended particles in this lagoon. Numerical model development (hydrodynamic, fine suspended sediment transport, wind-wave, small-scale atmospheric circulation) allowed the determination of circulation patterns in the lagoon and the charting of residence time, the later of which has been recently used in a series of ecological studies. Topical studies based on field measurements permitted the parameterisation of wave setup induced by the swell breaking on the reef barrier and the validation of a wind-wave model in a fetch-limited environment. The analysis of spatial and temporal variability of suspended matter concentration over short and long timescales , the measurement of grain size distribution and the density of suspended matter (1.27 kg l −1), and the estimation of erodibility of heterogeneous (sand/mud, terrigenous/biogenic) soft bottoms was also conducted. Aggregates were shown to be more abundant near or around reefs and a possible biological influence on this aggregation is discussed. Optical measurements enabled the quantification of suspended matter either in situ (monochromatic measurements) or remotely (surface spectral measurements and satellite observations) and provided indirect calibration and validation of a suspended sediment transport model. The processes that warrant further investigation in order to improve our knowledge of circulation and suspended sediment transport in the New Caledonia lagoon as well as in other coral reef areas are discussed, as are the relevance and reliability of the numerical models for this endeavour.

- by Ali Belmadani and +1
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- MARINE POLLUTION, Climate, New Caledonia, Multidisciplinary

Images of a scene captured with multiple cameras will have different color values because of variations in color rendering across devices. We present a method to accurately retrieve color information from uncalibrated images taken under uncontrolled lighting conditions with an unknown device and no access to raw data, but with a limited number of reference colors in the scene. The method is used to assess skin tones. A subject is imaged with a calibration target. The target is extracted and its color values are used to compute a color correction transform that is applied to the entire image. We establish that the best mapping is done using a target consisting of skin colored patches representing the whole range of human skin colors. We show that color information extracted from images is well correlated with color data derived from spectral measurements of skin. We also show that skin color can be consistently measured across cameras with different color rendering and resolutions ranging from 0.1 to 4.0 megapixels. V V

- by Harlyn Baker
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- Digital Photography, Imaging, Information Extraction, Color Correction

Dense wavelength division multiplexing optical networks use tunable devices such as distributed Bragg reflector laser diodes. These optical sources require a precise wavelength calibration according to the ITU grid, even with aged components. Some specific optical spectrum analyzers are commercially available. Unfortunately, measurements using those systems are generally relatively slow. We present and discuss in this paper a fast spectral measurement system that can easily be implemented in a laser diode package.

- by francesco BELLI
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- Physics, Biomedical Engineering, Data Analysis, Spectroscopy

... Time Series Optical Imagery John Dugan, Cindy Piotrowski, Seth Zuckerman, Clayton Chinn, Matt Yi and Ken Vierra Arete Associates 1550 Crystal Drive, Suite 703 Arlington, VA 22202 USA ... evaluting story tall) Howe Center on the... more

- by Clayton Chinn
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- Geology, Image Processing, Time Series, Gravity

The Thermal Infrared Sensor (TIRS) on board the Landsat Data Continuity Mission (LDCM) is a two-channel, push-broom imager that will continue Landsat thermal band measurements of the Earth. The core of the instrument consists of three... more

- by Allen Lunsford
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- Engineering, Physics, Remote Sensing, Modeling

Highlighting similarities and differences between networks is an informative task in investigating many biological processes. Typical examples are detecting differences between an inferred network and the corresponding gold standard, or evaluating changes in a dynamic network along time. Although fruitful insights can be drawn by qualitative or feature-based methods, a distance must be used whenever a quantitative assessment is required. Here we introduce the Ipsen-Mikhailov metric for biological network comparison, based on the difference of the distributions of the Laplacian eigenvalues of the compared graphs. Being a spectral measure, its focus is on the general structure of the net so it can overcome the issues affecting local metrics such as the edit distances. Relation with the classical Matthews Correlation Coefficient (MCC) is discussed, showing the finer discriminant resolution achieved by the Ipsen-Mikhailov metric. We conclude with three examples of application in functio...

- by Cesare Furlanello
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- Computer Science, Biology, Functional Genomics, Biological Network