Development of a three-dimensional color rendition space for tunable solid-state light sources

2021 ◽  
Vol 2021 (29) ◽  
pp. 136-140
Author(s):  
Dorukalp Durmus

The quality of building electric lighting systems can be assessed using color rendition metrics. However, color rendition metrics are limited in quantifying tunable solid-state light sources, since tunable lighting systems can generate a vast number of different white light spectra, providing flexibility in terms of color quality and energy efficiency. Previous research suggests that color rendition is multi-dimensional in nature, and it cannot be simplified to a single number. Color shifts under a test light source in comparison to a reference illuminant, changes in color gamut, and color discrimination are important dimensions of the quality of electric light sources, which are not captured by a single-numbered metric. To address the challenges in color rendition characterization of modern solid-state light sources, the development of a multi-dimensional color rendition space is proposed. The proposed continuous measure can quantify the change in color rendition ability of tunable solid-state light devices with caveats. Future work, discretization of the continuous color rendition space, will be carried out to address the shortcomings of a continuous three-dimensional space.

Author(s):  
Isabel Wünsche

Faktura, literally "texture," is related to the Russian avant-garde’s preoccupation with the fundamental principles of the creative process. The term, applied to a work of art, addresses the way in which materials are used, the processes, the surrounding environment, and the artistic devices; it characterizes the textural structure of a work of art and the manner by which it was constructed. As a creative principle, it rejects a pictorial space based on perspective and the illusion of three-dimensional space projected onto a flat canvas. The Russian formalist critic Viktor Shklovsky considered faktura to be the single most important quality of an object of art as a constructed object: it was the evidence of its having been made. He applied the term to poetic writing as well as the visual arts; in both cases faktura offered a visual demonstration of the properties inherent in a material or construction: "The whole effort of a poet and a painter is aimed first and foremost at creating a continuous and thoroughly palpable object, an object with a faktura." The term faktura remained a fluid concept during the 1910s, its essential qualities being further defined and developed by members of the avant-garde from 1913 well into the mid-1920s. While faktura, as initially used by members of the early Russian avant-garde, was characterized by the use of natural materials and a holistic–metaphysical approach to art, it was later adapted by the Constructivists to conform to a strictly materialist ideology and utilitarian orientation in artistic production.


2018 ◽  
Vol 3 (2) ◽  
pp. 81-97
Author(s):  
V. A. Ryabov

Hydroacoustic regularities of food behavior of dolphins are determined by characteristics and functionality of their acoustic signals. All the acoustic signals of dolphins are classified depending on their physical characteristics by the theory of signals and echolocation as follows: sequences of ultrashort ultrawideband coherent pulses – ‘clicks’, frequency-modulated (FM) simultones with uniformly distributed tones – ‘whistles’, packets of mutually coherent pulses (CI), packets of mutually noncoherent pulses (NI) and packets of versatile pulses (VI). They play the role of probing signals of six dolphin sonars optimized for solving various echolocation tasks. The possibilities of using the signals by dolphins in searching and classifying food objects by echolocation have been studied in this work on the basis of both experimental data obtained by the researcher and those available in literature. The dolphins can use sequences of ‘clicks’ to detect food objects (individual fish at the distance up to 70–110 m, a school of fish at the distance up to 450–600 m) and conspecifics (dolphins) (at the distance up to 450–600 m) and to classify food objects. The dolphins can use ‘whistles’ to detect food objects (individual fish at the distance up to 2 km, a school of fish at the distance up to 9–13 km) and conspecifics (dolphins) (at the distance up to 9–13 km) and to determine their range and relative radial velocity. ‘Whistles’ provide higher accuracy and the range of echolocation of food objects and conspecifics compared to ‘clicks’ (by more than an order of magnitude). Furthermore, the FM sonar provides the measure of the radial velocity of approaching or distance removing of underwater object to or from a dolphin. However, an acute analysis of the amplitude-time regularities of the fish echo for the purpose of their classification is the advantage of sonar using ‘clicks’. The dolphins can use the packs of CI at the distances shorter than 2.5 m for tracing the position dynamics of the prey aiming at accurate capture. The high hearing resolution of the dolphin in time is about 0.02 ms; it allows processing the subtle temporal dynamics of the echoes. Packs of NI (signals of spoken language) can be used by dolphins to organize various types of association and complex cooperation between themselves when hunting and catching fish. Packets of VI can be used by dolphins to expand the echolocation of the survey area around the dolphin in order to improve the quality of food objects monitoring, regardless of the position of the dolphin’s head, as well as to determine the range, relative radial velocity and class of food objects, at short distances. Evolution and perfection of various types of acoustic signals, sonars and various methods of processing echo signals in dolphins is caused, first of all, by optimization of hydroacoustic regularities of their food behavior, along with the need for orientation in three-dimensional space. One can assume the presence of similar hydroacoustic regularities of food behavior in Odontoceti based on the similarity of their acoustic signals and morphology. The acoustic regularities of food behavior of dolphins and bats are similar, despite the fact that they have different habitats (water and terrestrial-air), and these mammals belong to different orders of the animal kingdom (Сetacea and Chiroptera).


Author(s):  
Evgeniy Konopatskiy ◽  
Andrey Bezditnyi

The paper describes an approach to solid modeling of geometric objects in the form of an organized three-parameter set of points in three-dimensional space. The relevance of the research topic is due to the widespread use of solid-state models in various branches of science and technology, mechanical engineering, construction and medicine. Solid-state computer models are currently one of the basic computer graphics tools and an integral part of computer- aided design and calculation systems. It is widely used as one of the control elements of CNC machines and 3D printing, the development of information systems in the design and construction of buildings and structures, finite element calculations of deformed states in aircraft and mechanical engineering, their manufacture in medicine, etc. The choice of point calculus as a mathematical apparatus for the analytical description of solid models of geometric objects is substantiated. Examples of modeling sets of elliptical bodies and toroidal bodies in a simplex of three-dimensional space are given.


2020 ◽  
Vol 12 (6) ◽  
pp. 1040 ◽  
Author(s):  
Aleksandra Sekrecka ◽  
Damian Wierzbicki ◽  
Michal Kedzierski

Images acquired at a low altitude can be the source of accurate information about various environmental phenomena. Often, however, this information is distorted by various factors, so a correction of the images needs to be performed to recreate the actual reflective properties of the imaged area. Due to the low flight altitude, the correction of images from UAVs (unmanned aerial vehicles) is usually limited to noise reduction and detector errors. The article shows the influence of the Sun position and platform deviation angles on the quality of images obtained by UAVs. Tilting the camera placed on an unmanned platform leads to incorrect exposures of imagery, and the order of this distortion depends on the position of the Sun during imaging. An image can be considered in three-dimensional space, where the x and y coordinates determine the position of the pixel and the third dimension determines its exposure. This assumption is the basis for the proposed method of image exposure compensation. A three-dimensional transformation by rotation is used to determine the adjustment matrix to correct the image quality. The adjustments depend on the angles of the platform and the difference between the direction of flight and the position of the Sun. An additional factor regulates the value of the adjustment depending on the ratio of the pitch and roll angles. The experiments were carried out for two sets of data obtained with different unmanned systems. The correction method used can improve the block exposure by up to 60%. The method gives the best results for simple systems, not equipped with lighting compensation systems.


1983 ◽  
Vol 105 (3) ◽  
pp. 460-467 ◽  
Author(s):  
B. Ravani ◽  
B. Roth

This paper studies planar motion approximation problems in the context of a kinematic mapping. Since a planar displacement is determined by three parameters, it can be mapped into a point of a three-dimensional space. A (single-degree-of-freedom) planar motion can, therefore, be represented by a space curve in the space of the mapping and the problem of motion approximation becomes a curve fitting problem in this space. A mapping introduced by Blaschke is used and a general theory for planar motion approximation is developed. The theory is then applied to dimensional synthesis of four-link mechanisms. Furthermore, since the structural error (i.e., the quality of motion approximation) is dependent on the closeness of the fit in the space of the mapping, a general algebraic theory for determining closest fits to points in this space is developed. The theory is illustrated by a numerical example.


2019 ◽  
Vol 5 (1) ◽  
pp. 479-502 ◽  
Author(s):  
Aurelien David ◽  
Kevin A.G. Smet ◽  
Lorne Whitehead

Human vision provides useful information about the shape and color of the objects around us. It works well in many, but not all, lighting conditions. Since the advent of human-made light sources, it has been important to understand how illumination affects vision quality, but this has been surprisingly difficult. The widespread introduction of solid-state light emitters has increased the urgency of this problem. Experts still debate how lighting can best enable high-quality vision—a key issue since about one-fifth of global electrical power production is used to make light. Photometry, the measurement of the visual quantity of light, is well established, yet significant uncertainties remain. Colorimetry, the measurement of color, has achieved good reproducibility, but researchers still struggle to understand how illumination can best enable high-quality color vision. Fortunately, in recent years, considerable progress has been made. Here, we summarize the current understanding and discuss key areas for future study.


2019 ◽  
Vol 11 (4) ◽  
pp. 112 ◽  
Author(s):  
Przemysław Tabaka ◽  
Pawel Rozga

The paper presents the results of calculations of colorimetric parameters of LED sources operating at a temperature range from -25oC to 25oC. The chromaticity coordinates and color rendition quality parameters were calculated on the basis of registered spectral distributions of radiation. For individual LED chromaticity shift is illustrated at CIE 1931 x,y diagram with 3 step and 7 step MacAdam ellipses. Full Text: PDF ReferencesJ. P. Freyssinier, D. Frering, J. Taylor, N. Narendran, and P. Rizzo, Reducing lighting energy use in retail display windows. Sixth International Conference on Solid State Lighting, Proceedings of SPIE 6337, 63371L (2006). CrossRef Aman, M. M., et al., 2013. Analysis of the performance of domestic lighting lamps, Energy Policy, CrossRef E. Elijošiute, J. Balciukevičiute, G. Denafas, Life cycle assessment of; compact fluorescent and incandescent lamps: Comparative analysis. Environ Res. Eng. Manag. 61 (3), pp. 65-72, (2012), CrossRef D. Czyzewski, LED substitutes of conventional incandescent lamps Przeglad Elektrotechniczny R. 88, No. 11 (2012), CrossRef P. Tabaka, P. Rozga, Assessment of methods of marking LED sources with the power of equivalent light bulb, ulletin of the Polish Academy of Sciences. Technical Sciences, Vol. 65, No. 6, (2017) CrossRef I. Fryc, P. Jakubowski, K. Kołacz, Analysis of optical radiation parameters of compact discharge HID lamps and LED COB modules used for illuminating shop windows, Przeglad Elektrotechniczny,R. 93, No 11, (2017); pp. 186-189, CrossRef T. Kawabata, Y. Ohno; Optical measurements of OLED panels for lighting applications, pp 1176-1186 Jun 2013, Journal of Modern Optics, Vol. 60, 2013 Issue 14 CrossRef W. Żagan, Conditions necessary to replacing the conventional lamps by energy-saving lamps, Przeglad Elektrotechniczny R. 85, No. 5, pp. 100-104, (2009). DirectLink P. Tabaka; Influence of Ambient Temperature on Colour Properties of Low-Pressure Fluorescent Lamps, Light & Engineering, Vol. 23; No. 2; (2015). DirectLink W. R. Ryckaert, et al., Linear LED tubes versus fluorescent lamps: An evaluation. Energy Build. 49, pp. 429-436. CrossRef M. Zalesinska, J. Zablocka, K. Wandachowicz, Evaluation of Selected Parameters of Non-Directional Household Lamps, Conference: 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4), CrossRef I. Fryc; Measurement techniques of optical LEDs properties performed with compliance conformity with CIE 127:2007 standard, Przeglad Elektrotechniczny R. 85, No. 11, pp. 317-319, (2009) DirectLink IESNA, IES Approved Method: Measuring Lumen Maintenance of LED Light Sources. IES LM-80-08', IES Subcommittee on Solid-State Lighting of the IES Testing Procedures Committee (2018). DirectLink D. B. Judd, Estimation of chromaticity differences and nearest color temperature on the standard 1931 ICI colorimetric coordinate system. J. Opt. Soc. America 26 (11), 421, (1936) CrossRef CIE 177:2007 Colour Rendering of White LED Light Sources DirectLink CIE 13.3-1995 Method of Measuring and Specifying Colour. DirectLink CIE 224:2017 Colour Fidelity Index for accurate scientific use DirectLink CIE 15:2004 Colorimetry. DirectLink D. Mozysrska, M. Wyrwas, I. Fryc, The determination of the LEDs colorimetric parameters, in the range of their operating temperature, Przeglad Elektrotechniczny, R. 93, No. 4a, pp. 232-234, (2012). DirectLink J. Kowalska, Analysis of parameters describing the quality of the color rendering of light sources according to the IES TM-30-15 and the CIE 013.3-1995, Przeglad Elektrotechniczny, R. 93, No. 6; pp. 50-54, (2017) CrossRef J. Kowalska, I. Fryc, Colour rendition quality of typical fluorescent lamps determined by CIE Colour Fidelity Index and Colour Rendering Index, Przeglad Elektrotechniczny, R. 95, No. 7; (2019), pp. 94-97 CrossRef J. Kowalska, Ambiguity and limitations in determining the quality of the color rendering of light sources by index Ra (CIE CRI), Przeglad Elektrotechniczny, R. 93 No. 5, pp. 74-78, (2017) CrossRef I. Fryc, J. Fryc, A. Wasowski, Considerations about determining color rendering of light sources, Przeglad Elektrotechniczny, R. 92 No. 2, pp. 218-223, (2016) CrossRef I. Fryc, LED's spectral power distribution under different condition of operating temperature and driving current, Przeglad Elektrotechniczny, R. 86, No. 10, pp. 187-189, (2010). DirectLink A. David, P. Fini, K. Houser et al., Development of the IES method for evaluating the color rendition of light sources, Optics Express; Vol. 23; Issue 12, pp. 15888-15906, (2015). CrossRef K. Houser, M. Mossman, K. Smet et al, Tutorial, Color Rendering and Its Applications in Lighting, LEUKOS; Vol. 12, Issue 1-2; pp. 7-26; (2016). CrossRef


2021 ◽  
Vol 31 (3) ◽  
pp. 470-486
Author(s):  
Sergey A. Rakutko ◽  
Elena N. Rakutko

Introduction. Greenhouse lighting systems are an integral part of the system for growing plants in cultivation facilities with an artificial microclimate. The uniformity of light distribution over the growing area is important to increase energy efficiency and improve plant quality, among other requirements. The aim of the work is to consider the mathematical apparatus for describing the distribution of light over the surface and to justify the choice of ways to characterize the degree of lighting uniformity. Materials and Methods. The basic concepts of the subject area such as lighting, lighting body, horizontal lighting curve, luminous intensity curve are considered in terms of theoretical photometry. To assess the energy and ecological friendliness of the greenhouse horticulture, the lighting efficiency factor was used. Various methods for determining the average lighting value are presented. The formulas for the uniformity coefficients are presented. Experimental verification was carried out on a horizontal plane simulating a surface for growing plants. A luminary with a round-symmetric light distribution was used. Results. It has been found that the lighting values calculated by the proposed method at various points of the illuminated surface correspond to the experimentally obtained values. It has been shown that the coefficient taking into account the pattern of lighting distribution over all points of the surface carries a lot of information about the uniformity. A frequency graph for the lighting distribution value has been constructed and its practical applicability has been substantiated. The relationship between the lighting efficiency and uniformity of the generated lighting has been revealed. With reduced suspension height of the luminary, it is possible to increase significantly the lighting efficiency factor, however, the lighting uniformity deteriorates sharply. Discussion and Conclusion. There is proposed a method for assessing the energy efficiency by the lighting efficiency factor, which determines the proportion of the useful lighting falling on the surface in the total lighting generated by light sources. It is suggested that this indicator can characterize the ecological quality of photoculture, since it has been established its relationship with the uniformity of the created lighting, the impact of which on photoculture is described in the literature.


2017 ◽  
Vol 44 (4) ◽  
pp. 65-74 ◽  
Author(s):  
Michał Taraska ◽  
Remigiusz Iwańkowicz

The paper characterises a class of problems for packing boxes in the container. It presents the current state of knowledge in this area and distinguishes evolutionary algorithms, as the most promising in the search for quasi-optimal loading conditions. The method proposed in the paper focuses on certain criteria important from a practical point of view, which in a formalised manner have not been included so far in the solving-problems models. Apart from the traditional consideration of the problem of three-dimensional space loading maximisation, the proposed method considers the deviation of the loaded container weight centre from its symmetry planes and the availability of packages during unloading. New elements in the described method are: the applied criteria, penalty function, way of coding the container loading state in the evolutionary algorithm and fast crossover and mutations operators dedicated to the adopted coding. It was observed that the evolution in the developed algorithm occurs properly, that is seeking to minimise the criteria. The article also includes a calculation example showing the effect of the method with the discussion of the results indicating the advantages and disadvantages of the proposed solution. The performance of the algorithm has been considered in the context of time necessary to obtain the acceptable solution and quality of the obtained solution. It was found that the algorithm in its current form is a strong base for its further improvement.


Author(s):  
S. Khadpe ◽  
R. Faryniak

The Scanning Electron Microscope (SEM) is an important tool in Thick Film Hybrid Microcircuits Manufacturing because of its large depth of focus and three dimensional capability. This paper discusses some of the important areas in which the SEM is used to monitor process control and component failure modes during the various stages of manufacture of a typical hybrid microcircuit.Figure 1 shows a thick film hybrid microcircuit used in a Motorola Paging Receiver. The circuit consists of thick film resistors and conductors screened and fired on a ceramic (aluminum oxide) substrate. Two integrated circuit dice are bonded to the conductors by means of conductive epoxy and electrical connections from each integrated circuit to the substrate are made by ultrasonically bonding 1 mil aluminum wires from the die pads to appropriate conductor pads on the substrate. In addition to the integrated circuits and the resistors, the circuit includes seven chip capacitors soldered onto the substrate. Some of the important considerations involved in the selection and reliability aspects of the hybrid circuit components are: (a) the quality of the substrate; (b) the surface structure of the thick film conductors; (c) the metallization characteristics of the integrated circuit; and (d) the quality of the wire bond interconnections.


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