scholarly journals Spectral features of hydroacoustic noises in determination of class of underwater objects

2021 ◽  
pp. 28-38
Author(s):  
L. Statsenko ◽  
D. Kuzin
Keyword(s):  
Spectral Features

В настоящее время, во многих сферах успешно применяются системы принятия решения, основанные на анализе большого объема данных и методах машинного обучения. Чтобы верно классифицировать объект (или действие), необходимо определить его признаки, которые позволят добиться высокой точности классификации. В статье аналитически и экспериментально обосновывается выбор спектральных признаков гидроакустических шумов для решения задачи классификации подводных объектов с помощью методов машинного обучения. Обучение модели на большом количестве акустических данных и реализация сенсорной сети позволят создать систему оперативного реагирования на проникновение нежелательных объектов (катеров или ныряльщиков) в акваторию, подлежащую охране.

Determination of invert syrup adulterated in acacia honey by terahertz spectroscopy with different spectral features

2020 ◽  
Vol 100 (5) ◽  
pp. 1913-1921 ◽  
Author(s):  
Wen Liu ◽  
Yuying Zhang ◽  
Ming Li ◽  
Donghai Han ◽  
Wenjie Liu
Keyword(s):  
Terahertz Spectroscopy ◽  
Spectral Features ◽  
Acacia Honey

scholarly journals A spectroscopic survey of FHB stars near the south galactic pole

2009 ◽  
Vol 5 (S262) ◽  
pp. 422-423
Author(s):  
Silvia Rossi ◽  
Roberto Ortiz ◽  
Ronald Wilhelm ◽  
Roberto Costa ◽  
Timothy C. Beers
Keyword(s):  
High Probability ◽  
Main Sequence ◽  
Galactic Plane ◽  
Theoretical Models ◽  
Spectral Features ◽  
Horizontal Branch ◽  
Atmospheric Parameters ◽  
The South ◽  
Medium Resolution

AbstractWe present the results of a medium-resolution spectroscopic survey of 43 field horizontal-branch (FHB) candidates carried out near the south galactic pole, selected from the original list of FHB candidates compiled by Beers et al. (2007). The observation list includes only stars classified as “high-probability” candidates, according to their 2MASS infrared colours. Atmospheric parameters of some stars have been obtained by comparing some spectral features with theoretical models provided by Kurucz (1993). A comparison between the grid of model atmospheres with some parameters of the Hδ line allowed the determination of log g, whilst [Fe/H] was estimated by the equivalent widths of the MgII 4481 and Caii lines. About 77% of the sample have been classified as FHB stars, 10% as subdwarfs, whilst the remaining 13% are probably main-sequence A-type stars far from the Galactic plane.

scholarly journals Hyperspectral imaging of the degradation of meat and comparison with necrotic tissue in human wounds

2019 ◽  
Author(s):  
Amadeus Holmer ◽  
Christoph Homberger ◽  
Thomas Wild ◽  
Frank Siemers
Keyword(s):  
Hyperspectral Imaging ◽  
Near Infrared ◽  
Objective Evaluation ◽  
Infrared Range ◽  
Spectral Features ◽  
Necrotic Tissue ◽  
Tissue Discrimination ◽  
Near Infrared Range ◽  
Imaging Setup

The objective evaluation of scattering tissue and the discrimination of tissue types is an issue that cannot be solved with colour cameras and image processing alone in many cases. Examples can be found in the determination of freshness and ageing of meat, and the discrimination of tissue types in food technology. In medical applications tissue discrimination is also an issue, e.g. in wound diagnostics. A novel hyperspectral imaging setup with powerful signal analysis algorithms is presented which is capable of addressing these topics. The spectral approach allows the chemical analysis of material and tissues and the measurement of their temporal change. We present a method of hyperspectral imaging in the visible-near infrared range which allows both the separation and spatial allocation of different tissue types in a sample, as well as the temporal changes of the tissue as an effect of ageing. To prove the capability of the method, the ageing of meat (slices of pork) was measured and, as a medical example, the application of the hyperspectral imaging setup for the recording of wound tissue is presented. The method shows the ability to discriminate the different tissue components of pork meat, and the ageing of the meat is observable as changes in spectral features. An additional result of our study is the fact that some spectral features, which seem to be typical for the ageing of the meat, are similar to those observed in the necrotic tissue from wound diagnostics in medicine.

scholarly journals Abundances of C, N and O in Planetary Nebulae

1989 ◽  
Vol 131 ◽  
pp. 218-218 ◽  
Author(s):  
A. A. Nikitin ◽  
A. F. Kholtygin ◽  
A. A. Sapar ◽  
T. H. Feklistova
Keyword(s):  
Planetary Nebulae ◽  
Abundance Ratio ◽  
Evolutionary Status ◽  
Spectral Features ◽  
Giant Stars ◽  
Red Giant Stars ◽  
Red Giant ◽  
Abundance Determination

The abundances of C, N and O in planetary nebulae must correspond to the evolutionary status of their progenitor red giant stars. The best spectral features for abundance determination of these elements are the recombination lines, which depend weakly on the variations of Te and ne. The abundance ratio of the ions A+ and H+ can be given by [1–3].

scholarly journals Laboratory Determination of the Luminous Efficiency of Meteor Constituents

1971 ◽  
Vol 13 ◽  
pp. 83-87 ◽  
Author(s):  
Howard F. Savage ◽  
Charles A. Boitnott
Keyword(s):  
Cross Sections ◽  
Luminous Efficiency ◽  
Visible Spectral Range ◽  
Molecular Flow ◽  
Spectral Features ◽  
Velocity Range ◽  
Flow Conditions ◽  
Ionization Cross ◽  
Ionization Cross Sections

A crossed beam apparatus has been used to measure the emission and ionization cross sections for the prominent spectral features of Na, Ca, Mg, and Fe in collisions with N2 and O2 over the velocity range of 30 to 120 km/s. From the emission and ionization cross sections, the absolute luminous efficiencies in air were determined over the range of meteor velocities. The maximum luminous efficiencies for the brightest features were: greater than 1 percent for the Na D-lines, 0.2 percent for the CaI(2) singlet, 0.06 percent for the MgI(2) and MgI(3) triplets, and O.4 percent for Fe over the visible spectral range. These luminous efficiencies are valid for free molecular flow conditions for velocities above about 30 km/s and are directly applicable to spectroscopic observations of faint meteors. The luminous efficiency of a typical stone will be presented and compared with the efficiencies determined by other investigators. In contrast to previous work, the luminous efficiency found for stone in the present investigation decreases with velocity above about 50 km/s.

scholarly journals The origin and evolution of dense regions in the ISM, and their role in spectral features

2012 ◽  
Vol 8 (S292) ◽  
pp. 99-99
Author(s):  
Diego Falceta-Gonçalves
Keyword(s):  
Spectral Line ◽  
Numerical Simulations ◽  
Molecular Clouds ◽  
Spectral Features ◽  
Line Profiles ◽  
Origin And Evolution ◽  
Secular Evolution ◽  
Theoretical Assumptions ◽  
Order Of Magnitude

AbstractIn this work we discuss the turbulent evolution of molecular clouds and the formation of dense structures within. Typically, the clumps evolution occurs apart from the secular evolution of the turbulent mother cloud due to its high density and large inertia. Despite of current theoretical assumptions we show, by means of numerical simulations, that the clump lifetimes are greater than previously thought by more than an order of magnitude. The presence of dense and long-lived clumps modifies the spectral line profiles of clouds, which are strongly related to the determination of Larson's relations. We address the main modifications of these if a realistic distribution of dense structures is taken into account.

Determination of airway and tissue resistances after antigen and methacholine in nonhuman primates

1997 ◽  
Vol 83 (5) ◽  
pp. 1690-1696 ◽  
Author(s):  
Jeffrey B. Madwed ◽  
Andrew C. Jackson
Keyword(s):  
Lung Function ◽  
Input Impedance ◽  
Nonhuman Primates ◽  
Spectral Features ◽  
Respiratory Resistance ◽  
Zero Crossing ◽  
Cynomolgus Monkeys ◽  
Absolute Amplitude ◽  
Resistive Component

Madwed, Jeffrey B., and Andrew C. Jackson.Determination of airway and tissue resistances after antigen and methacholine in nonhuman primates. J. Appl. Physiol. 83(5): 1690–1696, 1997.—Antigen challenge of Ascaris suum-sensitive animals has been used as a model of asthma in humans. However, no reports have separated total respiratory resistance into airway (Raw) and tissue (Rti) components. We compared input impedance (Zin) and transfer impedance (Ztr) to determine Raw and Rti in anesthetized cynomolgus monkeys under control and bronchoconstricted conditions. Zin data between 1 and 64 Hz are frequency dependent during baseline conditions, and this frequency dependence shifts in response to A. suum or methacholine. Thus it cannot be modeled with the DuBois model, and estimates of Raw and Rti cannot be determined. With Ztr, baseline data were much less variable than Zin in all monkeys. After bronchial challenge with A. suum or methacholine, the absolute amplitude of the resistive component of Ztr increased and its zero crossing shifted to higher frequencies. These data can estimate Raw and Rti with the six-element DuBois model. Therefore, in monkeys, Ztr has advantages over other measures of lung function, since it provides a methodology to separate estimates of Raw and Rti. In conclusion, Ztr shows spectral features similar to those reported in healthy and asthmatic humans.

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