scholarly journals A Basis for Selecting Light Spectral Distribution for Evaluating Leaf Photosynthetic Rates of Plants Grown under Different Light Spectral Distributions

2017 ◽  
Vol 55 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Keach MURAKAMI ◽  
Ryo MATSUDA ◽  
Kazuhiro FUJIWARA
Keyword(s):  
Spectral Distribution ◽  
Photosynthetic Rates ◽  
Spectral Distributions

THE APPLICATION OF SEMIDEFINITE INTEGER PROGRAMMING MODEL FOR THE SIMULATION OF COMPLEX NETWORKS

2015 ◽  
Vol 18 (03n04) ◽  
pp. 1550015
Author(s):  
JIAO BO ◽  
LU ZHI-YONG ◽  
SHI JIAN-MAI
Keyword(s):  
Integer Programming ◽  
Complex Networks ◽  
Branch And Bound ◽  
Structural Design ◽  
Spectral Distribution ◽  
Programming Model ◽  
Node Degree ◽  
Integer Programming Model ◽  
Spectral Distributions ◽  
Feasible Solutions

Semidefinite integer programming model is an accurate tool for the structural design of networks. In this paper, we propose a semidefinite integer programming model with the constraints of spectral distributions and node degree distributions for the simulation of complex networks. Also, the feasible solutions and branch-and-bound solving algorithms of the model are designed. Based on eight metrics (e.g., spectral distribution, node degree distribution, clustering coefficients, etc.), the validity and practicability of the proposed method are illustrated.

scholarly journals Spectral distributions of periodic random matrix ensembles

2019 ◽  
Vol 10 (01) ◽  
pp. 2150011
Author(s):  
Roger Van Peski
Keyword(s):  
Random Matrix ◽  
Spectral Distribution ◽  
Eigenvalue Distribution ◽  
Limiting Spectral Distribution ◽  
Gaussian Unitary Ensemble ◽  
Random Matrix Ensembles ◽  
Spectral Distributions ◽  
Matrix Ensembles ◽  
General Correspondence ◽  
Unitary Ensemble

Koloğlu, Kopp and Miller compute the limiting spectral distribution of a certain class of real random matrix ensembles, known as [Formula: see text]-block circulant ensembles, and discover that it is exactly equal to the eigenvalue distribution of an [Formula: see text] Gaussian unitary ensemble. We give a simpler proof that under very general conditions which subsume the cases studied by Koloğlu–Kopp–Miller, real-symmetric ensembles with periodic diagonals always have limiting spectral distribution equal to the eigenvalue distribution of a finite Hermitian ensemble with Gaussian entries which is a ‘complex version’ of a [Formula: see text] submatrix of the ensemble. We also prove an essentially algebraic relation between certain periodic finite Hermitian ensembles with Gaussian entries, and the previous result may be seen as an asymptotic version of this for real-symmetric ensembles. The proofs show that this general correspondence between periodic random matrix ensembles and finite complex Hermitian ensembles is elementary and combinatorial in nature.

scholarly journals A Method for the Reduction of Out-of-Band Measurement Errors in Multi-band Instruments using Synthetic Source Distributions

2022 ◽  
Vol 2149 (1) ◽  
pp. 012018
Author(s):  
S W Brown ◽  
P-S Shaw
Keyword(s):  
Spectral Distribution ◽  
Measurement Errors ◽  
Source Spectrum ◽  
Arbitrary Distribution ◽  
Calibration Source ◽  
Band Filter ◽  
Sensor Measurement ◽  
Spectral Distributions ◽  
Measurement Biases ◽  
Multi Band

Abstract A method to reduce multi-band sensor measurement biases due to finite out-of-band response is described. The method takes advantage of the fact that out-of-band measurement errors cancel if the calibration source and the measured source have the same spectral distributions—independent of their spectral distributions or the magnitude of a sensor band’s out-of-band response. Using a known spectral responsivity, a synthetic, arbitrary source spectral distribution can replace a realized spectral distribution in the measurement equation and the signal can be calculated rather than measured. Given the freedom to select any arbitrary distribution for the synthetic source, the efficacy of the approach depends on the fidelity of the replication of the measured spectrum by the synthetic source spectrum. To illustrate the method, an example application is given of top-of-the-atmosphere measurements of water-leaving radiance by multi-band filter radiometers on celestial Earth-viewing sensors.

scholarly journals In ultraviolet microbeam irradiations, characteristics of the monochromator and lamp affect the spectral composition of the ultraviolet light and probably the biological results

1991 ◽  
Vol 98 (3) ◽  
pp. 415-422
Author(s):  
A. Forer
Keyword(s):  
Ultraviolet Light ◽  
Spectral Distribution ◽  
Spectral Composition ◽  
Band Width ◽  
Microbeam Irradiation ◽  
Ultraviolet Microbeam ◽  
Spectral Distributions

Biological conclusions recently published concerning ultraviolet (u.v.) microbeam irradiation of spindles are different from those we previously published. Several technical differences between the two sets of experiments were investigated. The spectral distributions in the light emitted from mercury-arc, xenon-mercury-arc, and xenon-arc lamps were measured, as were the spectral distributions after the light from these lamps passed through a monochromator that was set to various wavelengths and various half-band-widths. Both the source of the u.v. light and the half-band-width of the monochromator influence the spectral distribution of the light leaving the monochromator: depending on the conditions, the light leaving the monochromator is not necessarily of the same wavelength as that to which the monochromator is set. Differences in these aspects of the experiments could easily give rise to the different biological conclusions reached in the two sets of experiments.

scholarly journals New Infrared Observations of NGC 3603

1987 ◽  
Vol 115 ◽  
pp. 182-184 ◽  
Author(s):  
M. Roth ◽  
M. Tapia ◽  
M. T. Ruiz ◽  
P. Persi ◽  
M. Ferrari-Toniolo
Keyword(s):  
High Resolution ◽  
Spectral Distribution ◽  
Massive Star ◽  
Near Infrared ◽  
H Ii Regions ◽  
Infrared Observations ◽  
Star Forming ◽  
Photometric Observations ◽  
H Ii Region ◽  
Spectral Distributions

NGC 3603, one of the most massive H II regions in our galaxy, shows recent star forming activity (Frogel et al. 1977; Tapia 1981; Persi et al., 1985). In this paper we report new near-infrared maps and photometric observations in the complex region surrounding Irs 9, Irs 2 and Irs 8. Most data were gathered at the 1.5-m telescope of CTIO, using an InSb photometer. Tables 1 and 2 synthesize the observations and the results of the photometry. While the low resolution K map (Figure 1) shows basically the previously reported features, the high resolution K and L maps (shown superimposed in Figure 2), show that Irs 9 is the brightest source in the field, clearly resolved from Irs 2 and Irs 8. The presence of a previously unreported source some 22″N and 5″W of Irs 2, should be further investigated. The spectral distributions derived from our measurements and from previous ones by Persi et al. (1985) strongly suggest that the 10 and 20 μm fluxes reported by Frogel et al. (1977) at the position of Irs 2, probably correspond to Irs 9. Under this assumption, Irs 9 is probably a highly reddened massive star (1 μm to 20 μm luminosity, L∗ = 2.2 × 104 L⊙) while the luminosity of Irs 2 is less than 102 L⊙. We therefore conclude that Irs 9 is a young massive star surrounded by a warm (Tdust ∼ 250 K) dust envelope; Irs 2 seems to be the less obscured part of an associated H II region, as further corroborated by the Brγ emission and the free-free like spectrum and spectral distribution, as reported by Persi et al. (1985) and in this paper.

Problems with signal lighting colours’ recognition

2018 ◽  
Vol 561 (6) ◽  
pp. 12-15
Author(s):  
Grzegorz Owczarek
Keyword(s):  
Spectral Distribution ◽  
Optical Radiation ◽  
Light Emitting Diode ◽  
Graphical Analysis ◽  
Night Vision ◽  
Light Sources ◽  
Light Emitting ◽  
Signal Light ◽  
Different Types ◽  
Spectral Distributions

The article presents the main eye hazards caused by excessive eye exposure on optical radiation. The human eye sensitivity spectral distribution in the context of signal colour recognition was discussed. In order to explain the effects of the mechanism of phenomena responsible for the recognition of signal lights colour, a graphical analysis of spectral distributions of signal lights emitted from traditional incandescent sources and LED sources (light emitting diode) was performed. This analysis also takes into account the conditions under which observation of signal lights may take place (daylight and night vision conditions). The conclusions also indicate the further direction of studies on the influence of colour recognition affected by vision conditions, eye sensitivity spectral distribution (including disturbance of colour recognition) and different types of signal light sources.

scholarly journals Radiation Spectrum of Sequence of Electrons Moving in Spiral in Medium

2019 ◽  
Vol 20 (1) ◽  
pp. 5-12
Author(s):  
I.A. Konstantinovich ◽  
A.V. Konstantinovich
Keyword(s):  
Magnetic Fields ◽  
Spectral Distribution ◽  
Cherenkov Radiation ◽  
Radiation Spectrum ◽  
Radiation Power ◽  
Coherent Radiation ◽  
Transparent Medium ◽  
Interaction Method ◽  
Direct Numerical Method ◽  
Spectral Distributions

Integral expressions for spectral-angular and spectral distributions of the radiation power for the sequence of electrons moving in magnetic fields in isotropic transparent medium are investigated using the improved Lorentz`s self-interaction method. Special attention is given to the research of the fine structurre of the spectral distribution of the synchrotron-Cherenkov radiation of one, two, three and four point electrons moving along the spiral in medium. The effects of coherent radiation of harmonics and oscillations in spectrum of the synchrotron-Cherenkov radiation of two, three and four point electrons are established and investigated using the direct numerical method for calculation the function of spectral distributions of the radiation power.

scholarly journals THE SPECTRUM OF RANDOM KERNEL MATRICES: UNIVERSALITY RESULTS FOR ROUGH AND VARYING KERNELS

2013 ◽  
Vol 02 (03) ◽  
pp. 1350005 ◽  
Author(s):  
YEN DO ◽  
VAN VU
Keyword(s):  
Large Class ◽  
Random Matrices ◽  
Spectral Distribution ◽  
Inner Product ◽  
Limiting Spectral Distribution ◽  
Product Kernel ◽  
Gaussian Vectors ◽  
Spectral Distributions ◽  
As If

We consider random matrices whose entries are [Formula: see text] or f(‖Xi – Xj‖2) for iid vectors Xi ∈ ℝp with normalized distribution. Assuming that f is sufficiently smooth and the distribution of Xi's is sufficiently nice, El Karoui [The spectrum of Kernel random matrices, Ann. Statist.38(1) (2010) 1–50, MR 2589315 (2011a.62187)] showed that the spectral distributions of these matrices behave as if f is linear in the Marčhenko–Pastur limit. When Xi's are Gaussian vectors, variants of this phenomenon were recently proved for varying kernels, i.e. when f may depend on p, by Cheng–Singer [The spectrum of random inner-product Kernel matrices, preprint (2012), arXiv:1202.3155 [math.PR]]. Two results are shown in this paper: first, it is shown that for a large class of distributions the regularity assumptions on f in El Karoui's results can be reduced to minimal; and second, it is shown that the Gaussian assumptions in Cheng–Singer's result can be removed, answering a question posed in [The spectrum of random inner-product Kernel matrices, preprint (2012), arXiv:1202.3155 [math.PR]] about the universality of the limiting spectral distribution.

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