scholarly journals Modeling the Luminance Spatial-Angular Distribution in Lighting Scenes

2020 ◽  
pp. short35-1-short35-8
Author(s):  
Vladimir Budak ◽  
Victor Chembaev ◽  
Tatiana Meshkova ◽  
Victor Zheltov
Keyword(s):  
Angular Distribution ◽  
Reflection Coefficient ◽  
Incident Light ◽  
Quantitative Characteristic ◽  
Integral Characteristic ◽  
Human Eye ◽  
Regulatory Documents ◽  
Black Surface ◽  
Lighting Systems

Now days regulatory documents for non-special lighting systems, the illuminance and various parameters derived from it are normalized as a quantitative characteristic. In most cases, all calculations are carried out for illuminance on the floor of the room or on an imaginary working plane located at the height of the table. However, illuminance is an integral characteristic of incident light, while the human eye responds to light reflected from the surface. That is, if we take a completely black surface with a reflection coefficient equal to zero, then formally you can get the required illuminance on it, while visually we will not see anything, since nothing will be reflected from the surface. In terms of the human eye, luminance must be normalized instead of illuminance. Recently, the calculation and measurement of luminance was an extremely difficult task, so the it is understandable, that current regulatory documents describes almost illuminance normalization, but not luminance. This paper aims to modeling luminance spatial-angular distribution, which enables us to run the assessment of the lighting quality.

View-independent Modeling of Lighting Systems by Local Estimations of the Monte Carlo Method

Vestnik MEI ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 70-75
Author(s):  
Vladimir P. Budak ◽  
◽  
Viktor S. Zheltov ◽  
Tatyana V. Meshkova ◽  
Viktor D. Chembaev ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Angular Distribution ◽  
Monte Carlo Method ◽  
Light Source ◽  
Global Illumination ◽  
The Monte Carlo Method ◽  
Computer Aided ◽  
Radiosity Equation ◽  
Lighting Systems ◽  
Independent Calculation

Computer-aided designing of lighting systems has been remaining of relevance for more than ten years. The most popular CAD packages for calculating lighting systems, such as DIAlux and Relux, are based on solving the radiosity equation. By using this equation, the illuminance distributions can be modeled, based on which the standardized quantitative lighting characteristics can be calculated. However, the human eye perceives brightness, not illuminance. The qualitative parameters of lighting are closely linked with the spatial-angular distribution of brightness, for calculation of which it is necessary to solve the global illumination equation. An analysis of the engineering matters concerned with designing of lighting systems points to the obvious need for a so-called view-independent calculation of lighting scenes, which means the possibility to visually represent a scene from different positions of sighting (a camera). The approach based on local estimations of the Monte Carlo method as one of efficient techniques for solving the global illumination equation is considered, and an algorithm for view-independent modeling based on the local estimations method is presented. Various algorithms for solving the problem of searching the intersection for the casted beams from a light source with the studied illumination scene are investigated.

COMPARATIVE ANALYSIS OF THE CALCULATION OF LIGHTING SYSTEMS OF VARIOUS TYPES BASED ON INDUSTRIAL PREMISES

2021 ◽  
Vol 3 (1) ◽  
pp. 009-013
Author(s):  
A. D. BOGDANOV ◽  
◽  
R. V. SOLOPOV ◽  
◽  
◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Comparative Analysis ◽  
Calculation Methods ◽  
High Quality ◽  
Industrial Enterprises ◽  
Regulatory Documents ◽  
Innovative Method ◽  
Manual Methods ◽  
Lighting Systems

At present, the issues of economy and energy efficiency are actual for organizations. One of the ar eas of ener gy saving is the optimization of the functioning of lighting systems. Lighting of premises of industrial enterprises with a long stay of people is the object of research in this article. Based on comparative calculations, this article shows the efficiency of using the most common configurations of lighting systems that pr ovide high-quality and economical illumination of workplaces that meet the requirements of construction, technical and sanitary regulatory documents, as well as the efficiency of using software for designing lighting systems. To design the lighting of premises, design bureaus use manual methods for calculating the electric lighting of premises. The authors of the article presented an innovative method for designing electric lighting using the DIALux evo program. The program has combined all calculation methods and optimized them. The results of the wor k, obtained by calculation using the DIALux evo software, are advisory in the design of electr ic lighting systems.

The response of squid and fish to changes in the angular distribution of light

2003 ◽  
Vol 83 (4) ◽  
pp. 849-856 ◽  
Author(s):  
Lydia M. Mäthger
Keyword(s):  
Angular Distribution ◽  
Light Source ◽  
Incident Light ◽  
Vertical Plane ◽  
The Body ◽  
Horse Mackerel ◽  
Trachurus Trachurus ◽  
Light Reflex

This paper describes the responses of a squid (Alloteuthis subulata) and a fish (Trachurus trachurus) to changes in the angular distribution of light.  An apparatus was made that simulated the angular distribution of daylight in the sea. The apparatus enabled the direction of the brightest light to be changed and the positions of the animals in response to these changes were observed. Squid viewed head-on were observed to roll by a maximum of 20° when the incident light source was at angles between 20° and 90° (where 0° is vertically downwards). When viewed laterally, i.e. in the pitch plane, the squid were observed to position themselves more closely with respect to the angle of the light source, they swam in a near vertical plane when the incident light source was at an angle of 90°. Swimming movements in the roll and pitch plane became more horizontal with positions of the light source between 90 and 180°. Horse mackerel, in contrast, inclined their dorsal surfaces to almost perfectly match the angle of the incident light source, even swimming upside-down when light came from below. These experiments also revealed that squid display a counter-shading chromatophore pattern (‘Flexible Countershading’) in response to light coming from the sides, which involves darkening the side of the body facing the brightest light. The use of chromatophores in this way may explain why the dorsal light reflex in squid is so weak compared to that of fish.

Opalescence and concentration fluctuations in binary liquid mixtures near the critical mixing point - I. Experimental

1954 ◽  
Vol 224 (1156) ◽  
pp. 90-104 ◽  
Keyword(s):  
Angular Distribution ◽  
Light Intensity ◽  
Scattered Light ◽  
Incident Light ◽  
Liquid Mixtures ◽  
Binary Liquid Mixtures ◽  
Scattered Light Intensity ◽  
Binary Liquid ◽  
Wide Range ◽  
Critical Mixing

This investigation deals with the measurement of the coherent scattering of light in binary liquid mixtures near the critical mixing point, usually called ‘critical opalescence’, which is due to fluctuations of concentration produced by the thermal molecular movement. The apparent extinction of the incident light beam and the angular distribution of the scattered light intensity was measured by a photo-electric method over a wide range of wave-lengths in the visible and ultra-violet region and a range of temperatures above the critical point for nine suitably selected liquid mixtures. It was found that they could be grouped into two classes, each of which is characterized by a specific law of temperature and wave-length dependence of the transmitted and transversely scattered light intensity and a specific shape of the angular distribution of scattered light.

The azimuthal dependence of processes involving mesons

1940 ◽  
Vol 36 (1) ◽  
pp. 34-42 ◽  
Author(s):  
T. S. Chang
Keyword(s):  
Angular Distribution ◽  
Elastic Scattering ◽  
Electric Field ◽  
Incident Light ◽  
Azimuthal Angle ◽  
Static Electric Field ◽  
Azimuthal Dependence ◽  
Circularly Polarized ◽  
Reverse Process ◽  
Similar Dependence

The elastic scattering of Yukawa's particles, or mesons, by a static electric field is recalculated by considering the scattering as a process in which the incident meson is absorbed and another meson, i.e. the scattered meson, is created, and Laporte's result is confirmed. This method promises an easier handling of the second approximation.A similar dependence of the angular distribution of the emitted quanta upon the spin of the incident mesons in a process like Y− + P → N + hν is found. Thus, the angular distribution contains a dependence upon the azimuthal angle in general. For the reverse process, the angular distribution of the emitted mesons, both longitudinal and transverse, contains also a dependence upon the azimuthal angle, which disappears only when the incident light is circularly polarized.The writer wishes to thank Prof. W. Pauli for calling his attention to the azimuthal dependence in the problem of elastic scattering and Dr C. Møller for help given during the preparation of the paper.

A Discussion on photoelectron spectroscopy - Angular distributions and intensity in molecular photoelectron spectroscopy I. General theory for diatomic molecules

1970 ◽  
Vol 268 (1184) ◽  
pp. 147-157 ◽  
Keyword(s):  
Angular Distribution ◽  
Cross Section ◽  
Photoelectron Spectroscopy ◽  
Diatomic Molecules ◽  
Dipole Moments ◽  
Incident Light ◽  
Anisotropy Parameter ◽  
Polarization Vector ◽  
Central Field ◽  
Transition Dipole

A theory of the angular distribution of photoelectrons ejected with a given energy from diatomic molecules is presented. The differential cross-section OO is of the form a = ^ [l+ /JP ,(co»® )] where O Total is the total cross-section, B an anisotropy parameter and O the angle between the polarization vector of the incident light and the direction of the photoelectron. Expressions for O total and B in terms of internal transition dipole moments are obtained for transitions between individual rotational states of the molecule and ion, for either of Hund’s cases (a) or (b) . The formulae have been developed for central-field bases for the eigenstates of the electron before and after ionization. When rotational structure in the photoelectron spectrum is unresolved the angular distribution is independent of the choice of Hund’s case

A New System For Optomanual Semiautomatic Quantitative Image Analysis

1977 ◽  
Vol 35 ◽  
pp. 210-211
Author(s):  
H.P. Rohr
Keyword(s):  
Image Analysis ◽  
Volume Density ◽  
List Type ◽  
Distribution Analysis ◽  
Type Number ◽  
Point Counting ◽  
Human Eye ◽  
Quantitative Image ◽  
Point Density ◽  
Electronic Counting

Today, in image analysis the broadest possible rationalization and economization have become desirable. Basically, there are two approaches for image analysis: The image analysis through the so-called scanning methods which are usually performed without the human eye and the systems of optical semiautomatic analysis completely relying on the human eye.The new MOP AM 01 opto-manual system (fig.) represents one of the very promising approaches in this field. The instrument consists of an electronic counting and storing unit, which incorporates a microprocessor and a keyboard for choice of measuring parameters, well designed for easy use.Using the MOP AM 01 there are three possibilities of image analysis:the manual point counting,the opto-manual point counting andthe measurement of absolute areas and/or length (size distribution analysis included).To determine a point density for the calculation of the corresponding volume density the intercepts lying within the structure are scanned with the light pen.

Electron Scattering in Solids

1990 ◽  
Vol 48 (2) ◽  
pp. 4-5
Author(s):  
Ryuichi Shimizu ◽  
Ze-Jun Ding
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Angular Distribution ◽  
Elastic Scattering ◽  
Electron Scattering ◽  
Cross Sections ◽  
Expansion Method ◽  
Electron Excitation ◽  
Partial Wave Expansion ◽  
Backscattered Electrons

Monte Carlo simulation has been becoming most powerful tool to describe the electron scattering in solids, leading to more comprehensive understanding of the complicated mechanism of generation of various types of signals for microbeam analysis.The present paper proposes a practical model for the Monte Carlo simulation of scattering processes of a penetrating electron and the generation of the slow secondaries in solids. The model is based on the combined use of Gryzinski’s inner-shell electron excitation function and the dielectric function for taking into account the valence electron contribution in inelastic scattering processes, while the cross-sections derived by partial wave expansion method are used for describing elastic scattering processes. An improvement of the use of this elastic scattering cross-section can be seen in the success to describe the anisotropy of angular distribution of elastically backscattered electrons from Au in low energy region, shown in Fig.l. Fig.l(a) shows the elastic cross-sections of 600 eV electron for single Au-atom, clearly indicating that the angular distribution is no more smooth as expected from Rutherford scattering formula, but has the socalled lobes appearing at the large scattering angle.

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