scholarly journals Comparison with Standard as an Efficiency Evaluation Approach for the Forced Invariance Method

2020 ◽  
Vol 18 (4) ◽  
pp. 5-10
Author(s):  
Nikita G. Demin
Keyword(s):  
Similarity Measure ◽  
A Priori ◽  
Spectral Characteristics ◽  
Efficiency Evaluation ◽  
Multispectral Images ◽  
Algorithm Efficiency ◽  
Evaluation Approach

The Forced Invariance Method (FIM) is a vegetation suppression algorithm for multispectral images which is of great interest since it uses statistics collected only from the pixels of the image itself. Due to this a priori spectral characteristics of the captured objects are not required. For using the FIM or its modification in practice it is necessary to have some way to evaluate algorithm efficiency in order to analyze the results of experiments. This paper presents the method designed to solve this problem. Presumably, it is suitable for evaluating various algorithms, such as those designed to suppress vegetation. The proposed method is based on the idea of comparing a processed image with its standard using the similarity measure.

scholarly journals Water Extraction from Air: A Proposal for a New Indicator to Compare Air Water Generators Efficiency

Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 224
Author(s):  
Lucia Cattani ◽  
Anna Magrini ◽  
Paolo Cattani
Keyword(s):  
Energy Efficiency ◽  
Comprehensive Evaluation ◽  
Specific Energy Consumption ◽  
Energy Performance ◽  
Water Extraction ◽  
Coefficient Of Performance ◽  
Efficiency Evaluation ◽  
Evaluation Approach ◽  
Cycle Systems ◽  
Definition Of

Water extraction from air, based on reverse cycle systems, is becoming a technology more and more diffused and various models of air to water generators (AWG) are now available, all claiming the best efficiency. To date, there is not a standard indicator stating energy efficiency for AWGs, neither in the literature nor in technical practice. The only evaluation parameter, that can be found is a sort of specific energy consumption (SEC) without any clear indications about the involved calculation terms, definition of hypotheses, or environmental conditions. The current work is a first proposal of an indicator to standardise the AWG efficiency evaluation. The indicator is called WET (Water Energy Transformation); it states water production as a useful effect of an AWG machine and calculates its energy performance with an approach similar to COP (Coefficient of Performance) and EER (Energy Efficiency Ratio) evaluation. The indicator is meant to be a normalised tool that permits comparing different AWG machines, but it is also the first part of a wider study, currently under development that is oriented to obtain a global index formulation that combines WET itself, EER and COP, and it is intended for a comprehensive evaluation of all the useful effects of a reverse cycle in integrated machines, in compliance with the current efficiency evaluation approach. The current paper presents the WET equation, with a discussion about involved terms, a set of normalised calculation conditions and some application examples, including a comparison with SEC.

scholarly journals Partial inverse problems for quadratic differential pencils on a graph with a loop

2020 ◽  
Vol 28 (3) ◽  
pp. 449-463 ◽  
Author(s):  
Natalia P. Bondarenko ◽  
Chung-Tsun Shieh
Keyword(s):  
Inverse Problems ◽  
A Priori ◽  
Spectral Characteristics ◽  
The Other ◽  
Boundary Edge ◽  
Partial Inverse ◽  
Quadratic Pencil ◽  
Sturm Liouville ◽  
Differential Pencils ◽  
Liouville Operators

AbstractIn this paper, partial inverse problems for the quadratic pencil of Sturm–Liouville operators on a graph with a loop are studied. These problems consist in recovering the pencil coefficients on one edge of the graph (a boundary edge or the loop) from spectral characteristics, while the coefficients on the other edges are known a priori. We obtain uniqueness theorems and constructive solutions for partial inverse problems.

scholarly journals Increase the contrast of the image of objects in the active optoelectronic system with dynamic spectral processing of optical emitting

2020 ◽  
Vol 3 (59) ◽  
pp. 122-126
Author(s):  
O. Cherkashyna
Keyword(s):  
Light Emission ◽  
Block Diagram ◽  
A Priori ◽  
Spectral Characteristics ◽  
Optical Signal ◽  
Matched Filtering ◽  
A Priori Information ◽  
Spectral Processing ◽  
Optoelectronic System ◽  
Priori Information

The article discusses a method for increasing the contrast of images in an optoelectronic system based on active dynamic spectral matched filtering. The principles of constructing active optoelectronic systems with matched filtering are based on the fact that the optical system uses a set of amplitude-controlled radiation sources operating in different parts of the spectral range as emitting sources. It is essential that the energy composition of the light emission control signals is formed on the basis of a priori information about the characteristics of the target and the background, so as to reduce the value of the spectral components of the optical signal reflected from the surface belongs to the background and with minimal attenuation of the signal intensity belonging to the object. The method assumes the presence of a set of a priori information about the spectral characteristics of the background and the object to form the instrumental function for controlling the amplitude of emitting sources. The analysis of the mathematical and physical aspects of systems with dynamic spectral processing of active type optical emitting is made. It is shown that an active optoelectronic system with dynamic spectral processing can be considered as an analog processor for calculating the dot product of a vector by a vector. One of the factors is the reflection coefficient from a surface with a priori known characteristics, and the second is a dimmable multispectral signal. A block diagram of an optoelectronic system with dynamic spectral processing of optical emitting with active formation of the information field in order to increase the contrast of the object image has been developed. The goal of the article is to develop the mathematical and physical foundations for constructing an active optoelectronic system with dynamic spectral processing of optical emitting in order to increase the image contrast.

scholarly journals Quantitative measurement feasibility for 3D distributions of hydrodynamic quantities in the turbulent mixing zone of two gases

1997 ◽  
Vol 15 (1) ◽  
pp. 73-82 ◽  
Author(s):  
V.P. Bashurin ◽  
V.V. Bashurov ◽  
Yu.D. Bogunenko ◽  
G.A. Bondarenko ◽  
F.A. Pletenev ◽  
...  
Keyword(s):  
Density Distribution ◽  
Turbulent Mixing ◽  
Statistical Physics ◽  
A Priori ◽  
Spectral Characteristics ◽  
Laser Interferometry ◽  
Reconstruction Method ◽  
Experimental Conditions ◽  
Mixture Density ◽  
Reconstruction Methods

In doing research on the turbulent mixing (TM) of two gases different in density, it is of great interest to study experimentally the 3D density distribution pattern of chemically nonreactive gases in the TM zone. For this purpose, noncontact and, particularly, optical techniques to obtain experimental data may be attractive. This article discusses the possibility of using pulsed laser interferometry in this application. Based on this technique, the experiment should result in the mixture density distribution integrated along the light path. Requirements for high-quality interference patterns have been analyzed in application to typical experimental conditions, to show that they may be produced with specific restrictions set on the mixture constitution. Generally, the TM zone has no symmetry. Therefore, the problem of reconstructing 3D density distributions (TDD) of gases can be solved by sufficiently providing many TM zone integral projections (or aspects). It is technically difficult and expensive to achieve this large number of aspects (N> 10). Therefore, it is essential that a reconstruction method be selected to allow the solution of the problem with the least possible number of aspects. Given that the experiment data are incomplete, the reconstruction methods that are based on the concept of maximum data entropy did well. Information a priori about the solution to be sought for an isobaric gas mixture is that its each constituent has invariable density. Thus, a functional data entropy can be defined that is similar to Fermi gas in statistical physics. An algorithm has been suggested for reconstruction as a modified maximum-bounded entropy procedure (Bashurin et al. 1995). This makes reasonable good reconstruction achievable even with as few aspects as N = 4. Experiments on the study of TM of a propane jet in air using a four-aspects laser interferometer were provided and reconstruction of propane concentration distribution was conducted. The results allow determination of the TM zone spectral characteristics.

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