Peter Blattner
Present and Future Activities of the International Commission on Illumination (CIE)

Peter Bodrogi, Xue Guo, and Tran Quoc Khanh
Brightness in the Photopic Range: Psychophysical Modelling with Blue-Sensitive Retinal Signals

Vladimir P. Budak, Dmitry S. Efremenko, and Pavel A. Smirnov
Fraunhofer Diffraction Description in the Approximation of the Light Field Theory

Fedor I. Manyakhin, Arthur B. Vattana, and Lyudmila O. Mokretsova
Application of the Sah-Noyce-Shockley Recombination Mechanism to the Model of the Voltage-Current Relationship of LED Structures with Quantum Wells

Sergei V. Ershov, Dmitry D. Zhdanov, Alexei G. Voloboy, and Nikolay B. Deryabin
Method of Quasi-Specular Elements to Reduce Stochastic Noise in Illumination Simulation

Peter Blattner
Present and Future Activities of the International Commission on Illumination (CIE)

Peter Bodrogi, Xue Guo, and Tran Quoc Khanh
Brightness in the Photopic Range: Psychophysical Modelling with Blue-Sensitive Retinal Signals

Vladimir P. Budak, Dmitry S. Efremenko, and Pavel A. Smirnov
Fraunhofer Diffraction Description in the Approximation of the Light Field Theory

Fedor I. Manyakhin, Arthur B. Vattana, and Lyudmila O. Mokretsova
Application of the Sah-Noyce-Shockley Recombination Mechanism to the Model of the Voltage-Current Relationship of LED Structures with Quantum Wells

Sergei V. Ershov, Dmitry D. Zhdanov, Alexei G. Voloboy, and Nikolay B. Deryabin
Method of Quasi-Specular Elements to Reduce Stochastic Noise in Illumination Simulation

The article describes the main activities of the International Commission on Illumination in recent years. The most important publications are reflecting recent developments in lighting science and industry, including LED sources and luminaires test methods, fundamental recommendations concerning colorimetry, discomfort caused by glare from luminaires with a non-uniform luminance, as well as intelligent control of lighting systems. Human centric lighting and the non-visual effects of light on humans was highlighted. To promote standardization in the field of horticultural lighting the CIE is in the process of establishing a new JTC. In view of COVID‑19 pandemic outspread the use of germicidal UV radiation is of relevance to reduce both contact spread and airborne transmission of infectious agents. The CIE is responsible for worldwide standardization of the fundamentals, including metrology and vocabulary, as well as lighting education. The CIE considers it important to make digital products including validated calculation tools, apps, databases and machine-readable documents more available for many experts and it takes a step in this direction by provide open access to the individual CIE publications.

1. CIE S025:2015 Test Method for LED Lamps, LED Luminaires and LED Modules, Vienna, 2015.
2. CIE S025-SP1:2019 Test Method for OLED Luminaires and OLED Light Sources,, DOI: 10.25039/S025-SP1.2019, Vienna, 2019.
3. CIE015:2018 Colorimetry, 4th Edition, ISBN: 978–3–902842–13–8, DOI: 10.25039/TR.015.2018, Vienna, 2018.
4. CIE170–1: 2006 Fundamental chromaticity diagram with physiological axes – Part 1, ISBN: 978 3 901906 46 6, Vienna 2006.
5. CIE170–2::2015 Fundamental Chromaticity Diagram with Physiological Axes – Part 2: Spectral Luminous Efficiency Functions and Chromaticity Diagrams, ISBN: 978–3–902842–05–3, Vienna, 2015.
6. CIE232:2019 Discomfort Caused by Glare from Luminaires with a Non-Uniform Source Luminance, ISBN: 978–3–902842–15–2 DOI: 10.25039/TR.232.2019, Vienna 2019.
7. CIE S026:2018 CIE System for Metrology of Optical Radiation for ipRGC–Influenced Responses to Light, DOI: 10.25039/S026.2018, Vienna, 2018.
8. CIE187:2010 UV–C Photocarcinogenesis Risks from Germicidal Lamps, ISBN: 978 3 901906 81 7, Vienna 2010.
9. CIE155:2003 Ultraviolet Air Disinfection [8], ISBN: 978 3 901906 25 1, Vienna 2003.
10. IEC62471:2006/CIE S009:2002 Photobiological safety of lamps and lamp systems., Geneva 2006.
11. CIE S017/E:2011 International Lighting Vocabulary (ILV), also available at http://eilv.cie.co.at/, Vienna 2011.
12. IEC60050–845: 1987 (the International Electrotechnical Vocabulary, IEV), Geneva, 1987. Also available at http://www.electropedia.org
13. BIPM, 9th edition SI-Broschure, ISBN978–92–822–2272–0, Sèvres, 2019. Also available at https://www.bipm.org/en/publications/si-brochure/
14. BIPM/CIE, “Principle Governing Photometry” Rapport BIPM‑2019/05, Sèvres, 2019.
15. CIE018:2019 The Basis of Physical Photometry, 3rd Edition ISBN978–3–902842–24–4, DOI: 10.25039/TR.018.2019, Vienna 2019.
16. CIE99:1989 Lighting education (1983–1989), ISBN: 978 3 900734 36 7, Vienna 1989.

1. Commission Internationale de l’Éclairage. e-ILV. Available from http://eilv.cie.co.at/, 2014.
2. Rea M.S. The what and the where of vision lighting research. Lighting Research and Technology, 2018. V50, #1, pp. 14–37.
3. Stiles WS. The Eye, Brightness and Illuminating Engineering. Transactions of the Illuminating Engineering Society, 1952. V17, pp. 241–264.
4. Robinson W. Brightness Engineering. A.M.I.E.E. Transactions of the Illuminating Engineering Society, 1951. V16, pp. 61–85.
5. Fotios SA, Cheal C. Predicting lamp spectrum effects at mesopic levels. Part 1: Spatial brightness. Lighting Research and Technology, 2011. V43, #2, pp. 43–157.
6. Rea MS, Bullough JD, Brons JA. Parking lot lighting based upon predictions of scene brightness and personal safety. Lighting Research and Technology, 2015. V49, #3, pp. 293–304.
7. Fotios S, Atli D. Comparing Judgments of Visual Clarity and Spatial, Brightness through an Analysis of Studies Using the Category Rating Procedure. LEUKOS, 2012. V8, #4, pp. 261–281.
8. Jones LA. Colourimetry: Preliminary Draft of a Report on Nomenclature and Definitions. Journal of the Optical Society of America, 1937. V27, #6, pp. 207–211.
9. Optical Society of America, Committee on Colourimetry, The Science of Colour, New York, USA: Crowell, 1953.
10. Boyce P. Editorial: The paradox of photometry. Lighting Research and Technology, 2015. V47, #7, p. 767.
11. Berman SM, Jewett DL, Fein G, Saika G, Ashford F. Photopic luminance does not always predict perceived room brightness. Lighting Research and Technology, 1990. V22, #1, pp. 37–41.
12. Fotios SA. Lamp colour properties and apparent brightness: a review. Transactions of the Illuminating Engineering Society 2001. V33, #3, pp. 163–178.
13. Fotios SA, Levermore GJ. Chromatic effect on apparent brightness in interior spaces III: Chromatic brightness model. International Journal of Lighting Research and Technology, 1998. V30, #3, pp. 107–110.
14. Besenecker UC, Bullough JD. Investigating visual mechanisms underlying scene brightness. Lighting Research and Technology, 2016. V49, #1, pp. 16–32.
15. Rea MS, Radetsky LC. Toward a model of outdoor lighting scene brightness. Lighting Research and Technology, 2011. V43, #1, pp. 7–30.
16. Vidovszky-Németh A, Schanda J. White light brightness–luminance relationship. Lighting Research and Technology, 2012. V44, #1, pp. 55–68.
17. Fotios S, Levermore GJ. Perception of electric light sources of different colour properties. International Journal of Lighting Research and Technology, 1997. V29, #3, pp. 161–171.
18. Nayatani Y. A colourimetric explanation of the Helmholtz–Kohlrausch effect. Colour Research and Application, 1998. V23, #6, pp. 374–378.
19. Burns SA, Smith VC, Pokorny J, Elsner AE. Brightness of equal-luminance lights. Journal of the Optical Society of America, 1982. V72, #9, pp. 1225–1231.
20. Fotios SA, Levermore GJ. Chromatic effect on apparent brightness in interior spaces, II: SWS lumens model. Lighting Research and Technology, 1998. V30, #3, pp. 103–106.
21. Smith VC, J. Pokorny J. Spectral sensitivity of the foveal cone photopigments between 400 and 500 nm. Vision Research, 1975. V15, #2, pp. 161–171.
22. Commission Internationale de l’Éclairage. Models of heterochromatic brightness matching. Publ. CIE118–1995. CIE Collection in Colour and Vision, 1995. V118, #2.
23. Guth SL, Massof RW, Benzschawel T. Vector model for normal and dichromatic colour vision. Journal of the Optical Society of America, 1980. V70, #2, pp. 197–212.
24. Yaguchi H, Ikeda M. Subadditivity and superadditivity in heterochromatic brightness matching. Vision Research, 1983. V23, #12, pp. 1711–1718.
25. Kokoschka S, Bodmann HW. Ein konsistentes System zur photometrischen Stralungsbewertung im gesamten Adaptationsbereich. In: Proceedings of the CIE18th Session, London, 1975.
26. Kokoschka S: Advantage of 4-components system and its application to photometer, Proc.1994 Annual Conference and International Symp of IEI Japan, Ohmiya, 1994. Pp. 55–62.
27. Stockman A, Sharpe LT. Spectral sensitivities of the middle- and long-wavelength sensitive cones derived from measurements in observers of known genotype. Vision Research, 2000. V40, #13, pp. 1711–1737.
28. Stockman A, Sharpe LT, Fach CC. The spectral sensitivity of the human short-wavelength cones. Vision Research, 1999. V39, #17, pp. 2901–2927.
29. Rea MS, Figueiro MG, Bierman A, Bullough JD. Circadian light. Journal of Circadian Rhythms 2010. V8, #1, pp. 1–10.
30. Dacey DM, Liao HW, Peterson BB, Robinson FR, Smith VC, Pokorny J, Yau KW, Gamlin PD. Melanopsinexpressing ganglion cells in primate retina signal colour and irradiance and project to the LGN. Nature, 2005. V433, #7027, pp. 749–754.
31. Commission Internationale de l’Éclairage. Publ. CIE212–2014. Guidance towards Best Practice in Psychophysical Procedures Used when Measuring Relative Spatial Brightness, 2014.
32. Ichikawa H, Tanabe S, Hukami K. Standard Pseudoisochromatic Plates for Acquired Colour Vision Defects, Part II. Tokyo, Japan: Igaku-Shoin Medical Publishers, 1983.
33. Lanthony P. The desaturated panel d‑15. Documenta Ophthalmologica, 1978. V46, #1, pp. 185–189.
34. Costa M, Gaddi C. Colour Name Distances Scaled by Thurstone’s Ranking Order Psychophysical Method. Journal of Vision, 2016. V16, #12, p. 824.
35. Fisher RA. On the Probable Error of a Coefficient of Correlation Deduced from a Small Sample. Metron, 1921. V1, pp. 3–32.
36. Ikeda M, Ikeda J, Ayama M. Specification of individual variation in luminous efficiency for brightness. Colour Research and Application, 1992. V17, pp. 31–44.
37. Kimura-Minoda T, Kojima Sh, Fujita Y, Ayama M. Study on Glare of LED lamp and Individual Variations of Brightness Perception. In: Proceedings of the ISAL 7th International Symposium on Automotive Lighting, 2007.
38. Nayatani Y, Sobagaki H. Causes of individual differences on brightness/luminance (B/L) ratios. Journal of Light and Visual Environment, 2003. V27, pp. 30–34.
39. Yaguchi H, Kawada A, Shioiri S, Miyake Y. Individual differences of the contribution of chromatic channels to brightness. Journal of the Optical Society of America, 1993. V10, pp. 1373–1379.
40. Fotios SA, Cheal C. Brightness matching with visual fields of different types. Lighting Research and Technology, 2010. V43, pp. 73–85.
41. Fotios S, Atli D, Cheal C, Hara N. Lamp spectrum and spatial brightness at photopic levels: Investigating prediction using S/P ratio and gamut area. Lighting Research and Technology, 2014. V47, #5, pp. 595–612.
42. Sharpe LT, Stockman A, Jagla W, Jägle H. A luminous efficiency function, V*(λ), for daylight adaptation. Journal of Vision, 2005. V5, #11, pp. 948–968.
43. Rinner O, Gegenfurtner KR. Time course of chromatic adaptation for colour appearance and discrimination. Vision Research, 2000. V40, #14, pp. 1813–1826.
44. Wong KY, Dunn FA, Berson DM. Photoreceptor Adaptation in Intrinsically Photosensitive Retinal Ganglion Cells. Neuron, 2005. V48, #/6, pp. 1001–1010.
45. Rea MS. The Trotter Paterson Lecture 2012: Whatever happened to visual performance. Lighting Research and Technology, 2012. V44, #2, pp. 95–108.
46. Land EH, McCann JJ. Lightness and Retinex Theory. Journal of the Optical Society of America, 1971. V61, #1, pp. 1–11.
47. Yamakawa M, Tsujimura S, Okajima K. A quantitative analysis of the contribution of melanopsin to brightness perception. Scientific Reports, 2019. V9, p. 7568, https://doi.org/10.1038/s41598–019–44035–3.

The wavelength is that natural scale that determines the applicability domains of the ray approximation and the wave approximation of light. If the change of the radiation power spatial density is significant at the wavelength scale, then we deal with the light diffraction phenomenon, which is a subject to the wave optics. Consider the diffraction phenomenon at the diaphragm. It is possible to distinguish the near zone with significant wave inhomogeneities (i.e. the Fresnel zone) and the far Fraunhofer diffraction zone, in which the wave becomes close to homogeneous (the so-called quasi-homogeneous) and the ray approximation is possible. The problem is that there is no explicit relationship between the radiance of the rays before and after diaphragm. Method for determining the boundary conditions for the radiance in the Fraunhofer zone through the radiance of the incident radiation is proposed in the paper. This approach for computing the radiance field in the Fraunhofer zone can be generalized to other problems of optics, thereby providing the possibility of using computationally efficient ray-approximation-based methods to determine the light fields.

1. Born M., Wolf E. Principles of optics. Cambridge: Cambridge University Press, 1999. P. 720.
2. Budak V.P. Theory of the light field, Section 2.1. in the Reference Book on Lighting Engineering, Ed. Yu.B. Eisenberg and G.V. Boos. Editorial Board of the journal “Lighting Engineering”, 2020. P. 829.
3. Apresyan L.A., Kravtsov Yu.A. Radiation Transport Theory: Statistical and Wave Effects. Amsterdam: OPA, 1996. P. 456.
4. Wigner E. On quantum corrections for thermodynamic equilibrium. Phys. Rev., 1932. V40, #6, pp. 749–759.
5. Abbe E. Beitraege zur Theorie des Mikroskops und der mikroskopischen Wahrnehmung. Archiv f. Mikroskopische Anat., 1873. B.9. S.413.
6. Hopkins H.H. On the Diffraction Theory of Optical Images. Proc. R. Soc. Lond. A, 1953. V217, pp. 408–432.
7. Hopkins H.H. The Frequency Response of a Defocused Optical System. Proc. R. Soc. Lond. A, 1955. V231, pp. 91–103.
8. Steel W.H. The Defocused Image of Sinusoidal Gratings. Optica Acta: International Journal of Optics, 1956. V3, #2, pp. 65–74.
9. Mie G. Beiträge zur Optik trüber Medien, speziell kolloidaler Metallösungen, Annalen der Physik, 1908. B.330. S.377–445.

1. Shockley W. The Theory of p – n Junctions in Semiconductors and p – n Junction Transistors // Belt Syst. Tec. J. 1949, Vol. 28, pp. 435–489.
2. Sah C. T., Noyce R.N., Shockley W. Carrier Generation and Recombination in P-N Junctions and P-N Junction Characteristics // Proc. IRE. 1957, Vol. 45, pp. 1228–1243.
3. Choo, S.C. Carrier generation-recombination in the space-charge region of an assymmetrical p-n junction // Solid State Electron. 1968, Vol. 11, pp. 1069–1077.
4. Sze S.M. Physics of Semiconductor Devices. Translated from English into Russian under the editorship of R.A. Suris. In 2 books. Book 1, 2nd edition, revised and supplemented. Moscow, Mir, 1984, 456 p.
5. Nakamura S., Iwasa M.S. Method of manufacturing p-tipe compound semicondoctors/ Patent N5, 306,662. Apr.1994. Japan.
6. Amano H., Akasaki I. et.al. Method for producing a luminous element of III-group nitride / Patent N5, 496,766. Mar. 1996. Japan.
7. Kong H-S., Leonard M., Bulman G., Negley G., Edmond J. AlGaN/GaN/AlGaN double-heterojunction blue LEDs on 6H-SiC substrates// Mat. Res. Soc. Proc. 1996, Vol. 395, pp. 903–907.
8. Nakamura, S. InGaN light-emitting diodes with quantum-well structures // Mat. Res. Soc. Pros. 1996, Vol. 395, pp. 979–887.
9. Kudryashov V.E., Turkin A.N., Yunovich A.E., Kovalyov A.N., Manyakhin F.I. Electroluminescence Properties of InGaN/AlGaN/GaN Light Emitting Diodes With Multiple Quantum Wells [Lyuminestsentnyye i elektricheskiye svoystva svetodiodov InGaN/AlGaN/GaN s mnozhestvennymi kvantovymi yamami] // FTP. 1999, Vol. 33, issue 4, pp. 445–450.
10. Yunovich A.E., Kudryashov V.E., Turkin A.N., Kovalev A.N., Manyakhin F.I.. Electroluminescence Properties of InGaN/AlGaN/GaN Light Emitting Diodes with Multiple Quantum Wells // MRS Intern. J. Nitride Semicond. Res. 1999, 4S1, G6, p. 29.
11. Yunovich, A.E., Kudryashov, V.E., Mamakin, S.S., Turkin, A.N., Kovalev, A.N., Manyakhin, F.I. Spectra and quantum efficiency of light emitting diodes based on GaN-heterostructures with quantum wells // Physica Status Solidi (A). 1999, Vol. 176, No. 1, pp. 125–130.
12. Manyakhin, F.I. Kovalev, A.N., Kudryashov, V.E., Mamakin, S.S., Yunovich, A.E. Change of charge centers distribution in AlGaN/InGaN/GaN heterostructures with multiple quantum wells during LED’s aging at high currents” // The Fourth European GaN Workshop. Nottingham, Abstract, 2000, 2D.
13. Bochkaryova N.I., Rebane Yu.T. Shreter Yu.G. Growth of Shockley-Reed-Hall Recombination Rate in InGaN/GaN Quantum Wells as the Major Mechanism of Loss of LED Efficiency at High Injection Levels [Rost skorosti rekombinatsii Shokli-Rida-Holla v kvantovykh yamakh InGaN/GaN kak osnovnoy mekhanizm padeniya effektivnosti svetodiodov pri vysokikh urovnyakh inzhektsii] // FTP, 2015, Vol. 49, issue 12, pp. 1714–1719.
14. Risovanyy V.D., Svetukhin V.V., Vostretsov D. Ya., Vostretsova L.N., Ambrozevich A.S., Ermakov M.S. The Effect of Continuous Flow of Forward Current on Electric Characteristics of InGaN-Based LEDs [Vliyaniye dlitelnogo protekaniya pryamogo toka na elektricheskiye kharakteristiki svetodiodov na osnove In-GaN] // Successes of Applied Physics [Uspekhi prikladnoy fiziki]. 2013, Vol. 1, issue 1, pp. 92–96.
15. Pikus G.E. Basics of the Theory of Semiconductor Devices [Osnovy teorii poluprovodnikovykh priborov]. Moscow: Nauka, GRFML, 1965, 448 p.
16. Zang M., Bhattacharya P., Singh J., Hinckley J. Direct measurement of auger recombination in In0.1Ga0.9N/GaN quantum well and its impact on the efficiency in In0.1Ga0.9N/GaN multiply quantum well light emitting diodes // Applied Physics Letters. 2009, Vol. 95, No. 20, pp. 1108.
17. Hopkins M.A., Allsopp, D.W.E., Kappers, M.J. Oliver, R.A., Humpreys, C.J.. The ABC model of recombination reinterpreted: Impact on understanding carrier transport and efficiency droop in InGaN/GaN light emitting diodes // J. Appl. Phys. 2017, Vol. 122, No. 23, p. 4505.
18. David A., Hurni C.A., Young N.G., Craven M.D. Electrical properties of III-nitride LEDs recombination-based injection model and theoretical limits to electrical efficiency and electroluminescent cooling // Appl. Phys. Lett. 2016. Vol. 109, No. 8, pp. 3501.
19. Dai Q., Shan Q., Wang J., Chhajed S., Cho J.M., Shubert E.F., Crauford M.H., Koleske D.D., Kim M.-H., Park Y.. Carrier recombination mechanisms and efficiency droop in GaInN/GaN light-emitting diodes // Appl Phys. Lett. 2010, Vol. 97, No. 13, pp. 3507.
20. Masui H., Nakamura S., DenBaars S.P. Tecnique to evaluate the diode ideality factor of light-emitting diodes // Appl. Phys. Lett. 2010, Vol. 96, No. 7, pp. 3509.
21. Masui H. Diode ideality factor in modern lightemitting diodes // Semicond. Sci. Technol. 2011, Vol. 26, No. 7, pp. 5011–5016.
22. Prudaev I.A., Skakunov M.S., Lelekov M.A., Ryaboshtan Yu.L., Gorlachuk P.V., Marmalyuk A.A. RecombinantCurrents in LEDs Based on Multiple Quantum Wells (AlxGa1-x)0.5In0.5P/(AlyGa1-y)0.5In0.5P [Rekombinatsyonnyye toki v svetodiodakh na osnove mnozhestvennykh kvantovykh yam (AlxGa1-x)0.5In0.5P/(AlyGa1-y)0.5In0.5P] // Izvestiya vuzov. Fizika. 2013, Vol. 56, issue 8, pp. 44–47.
23. Torchinskaya T.V., Karabaev A.G., Sheynkman M.K. Injection-Stimulated Transformation of Luminescence Spectra of Green GaP: N LEDs [Inzhektsionno-stimulirovannaya transformatsiya spektrov lyuminestsentsii zelyonykh GaP: N-svetodiodov] // FTP. 1990, Vol. 24, issue 8, pp. 1337–1348.
24. Abdullaev Zh.S., Gusev M. Yu., Zyuganov A.N., Torchinskaya T.V. Parameters of Deep Centres in AlGaAs LEDs Evaluated by Capacity and Injection Spectroscopy Methods [Parametry glubokikh tsentrov v svetodiodakh AlGaAs otsenyonnyye metodami emkostnoy i inzhektsionnoy spektroskopii] // Ukr. Phys. Journal. 1989. Vol. 34, issue 8, pp. 1220–1224.
25. Manyakhin F.I. Mechanism and Pattern of Lowering of Luminous Flux of LEDs Based on AlGaN/In-GaN/GaN Structures with Quantum Wells with Continuous Flow of Forward Current of Different Density [Mekhanizm i zakonomernost snizheniya svetovogo potoka svetodiodov na osnove struktur AlGaN/InGaN/GaN s kvantovymi yamami pri dlitelnom protekanii pryamogo toka razlichnoy plotnosti] // FTP. 2018. Vol. 52, issue 3, pp. 378–384.
26. Manyakhin F.I. The Role of the Compensated Layer in Formation of the Voltage-Current Relationship of LEDs Based on Wide Bandgap Semiconductors [Rol kompensirovannogo sloya v formirovanii volt-ampernoy kharakteristiki svetodiodov na osnove shirokozonnykh poluprovodnikov] // Izvestiya vuzov. Materialy elektronnoy tekhniki. 2009, Vol. 3, pp. 51–56.
27. Goryunov N.N., Manyakhin F.I., Klebanov M.P., Lukashev N.V. Impulse Three-Frequency Method of Measurement of Charged Centre Parameters in the Space Charge Region of Semiconductor Structures [Impulsnyy tryokhchastotnyy metod izmereniya parametrov zaryazhennykh tsentrov v oblasti prostranstvennogo zaryada poluprovodnikovykh struktur] // Pribory i sistemy upravleniya. 1999, Vol. 10, pp. 46–49.
28. Manyakhin F.I. The Nature of Resistance of the Compansated Layer and Recombination Mechanisms in LED Structures [Priroda soprotivleniya kompensirovannogo sloya i mekhanizmy rekombinatsii v svetodiodnykh strukturakh] // Izvestiya vuzov. Materialy elektronnoy tekhniki. 2006, Vol. 4, pp. 20–25.
29. NSM Archive. Physical Properties of Semiconductors. URL: http://www.ioffe.rssi.ru/SVA/NSM/Semicond/(accessed on: 28.02.2020).

When simulating the propagation of light, luminance/ radiance brought by a ray is calculated from the optical properties of the scene objects it interacts with. According to their optical properties, objects can be roughly divided into diffuse and specular. In Monte Carlo ray tracing luminance/radiance is calculated only for diffuse surfaces. When a ray hits a specular a surface, it is reflected (or refracted) until it reaches a diffuse surface, and only then the luminance/radiance is calculated. In the proposed approach, diffuse elements are further divided into genuine diffuse and quasi-specular elements. The most natural criterion for the latter is that it scatters light in a narrow cone about the specular direction. An element of the scene can also be a superposition of both types when its scattering function is a sum of the genuine diffuse and quasi-specular parts. This article shows how different components of illuminance/irradiance interact with quasi-specular objects and describe how this works in the bi-directional stochastic ray tracing. The proposed approach significantly reduces stochastic noise for multiple scenes. This method is also applicable for simulation of volume scattering, treating the phase function of the medium as quasi-specular. In this case, the choice of quasi-specular objects is not based on the nature of the bidirectional scattering distribution function (BSDF): the medium is treated as completely quasi-specular while the surfaces, even if their BSDFs are narrower, remain genuine diffuse. The article shows the advantage of this approach.

1. H. W. Jensen, Global illumination using photon maps, in Proceedings of the Eurographics Workshop on Rendering Techniques ‘96, London, UK, Springer-Verlag, 1996. pp. 21–30.
2. H. W. Jensen and P. Christensen, High quality rendering using ray tracing and photon mapping, in ACM SIGGRAPH 2007 Courses, SIGGRAPH ‘07, (New York, NY, USA), ACM, 2007.
3. T. Hachisuka and H.W. Jensen, Stochastic progressive photon mapping, in ACM SIGGRAPH Asia 2009 Papers, SIGGRAPH Asia ‘09, New York, NY, USA, ACM, 2009. pp. 141:1–141:8.
4. M. Pharr and G. Humphreys, Physically Based Rendering, Second Edition: From Theory To Implementation. San Francisco, CA, USA: Morgan Kaufmann Publishers Inc., 2nd ed., 2010.
5. Д.Д. Жданов, С.В. Ершов, А.Г. Волобой, Адаптивный выбор глубины трассировки обратного луча в методе двунаправленной стохастической трассировки лучей, in Proceedings of 25-th International Conference on Computer Graphics and Vision, September 22–25, Protvino, 2015. pp. 44–49.
6. J. Vorba, Bidirectional photon mapping, in Proceedings of CESCG 2011: The 15th CentralEuropean Seminar on Computer Graphics, Charles University, Prague, 2011.
7. S. V. Ershov, D.D. Zhdanov, and A.G. Voloboy, Estimation of noise in calculation of scattering medium luminance by MCRT, Mathematica Montisnigri, V14, 2019. pp. 60–73.
8. I. Georgiev, J. Krivanek, T. Davidovic, and P. Slusallek, Light transport simulation with vertex connection and merging, ACM Trans. Graph., Nov. 2012. V31, pp. 192:1–192:10.
9. S. Popov, R. Ramamoorthi, F. Durand, and G. Drettakis, Probabilistic Connections for Bidirectional Path Tracing, Computer Graphics Forum, 2015.
10. N. Dodik, Implementing probabilistic connections for bidirectional path tracing in the Mitsuba Renderer, Sept. 2017.
11. J. T. Kajiya, The rendering equation, in Proceedings of the 13th Annual Conference on Computer Graphics and Interactive Techniques, SIGGRAPH ‘86, New York, NY, USA, ACM, 1986. pp. 143–150.
12. S. V. Ershov, D.D. Zhdanov, and A.G. Voloboy, Treating diffuse elements as quasi-specular to reduce noise in bi-directional ray tracing, Preprint of the Keldysh Institute of Applied Mathematics, 2018. #122.
13. G. Pomraning, On the Henyey-Greenstein approximation to scattering phase functions, Journal of Quantitative Spectroscopy and Radiative Transfer, 1988. V39, #2, pp. 109–113.

In the premises of residential buildings, there are practically no requirements for the conditions of visual work. The light environment is evaluated by the criterion of the saturation of the premises with natural light. The required time of using natural light and providing natural lighting in space are also of great importance here. The task for residential buildings is to link these criteria to create an integrated method of rationing natural lighting in such rooms. The article discusses the modern trends in development of regulations of natural lighting from traditional, using Daylight Factor (D), to the modern ones, connected with dynamic evaluation of day lighting in time and space, necessarily taking into account real statistical brightness distribution on the sky. Evaluation of Daylight Factor method analyses its assessment, energy indicators and provides a comparison with the norms of Germany DIN. The results of research at MGSU on the evaluation of day lighting using the spatial criterion of the light field – cylindrical illuminance, which best describes the saturation of the light of the room are presented. It is noted that the full amount of natural light is not required over the entire area of the living room during the whole daylight hours. In this case, you can find the relationship between D and the coefficient of natural cylindrical illuminance (Dci). This provides a link between traditional regulation and regulation on the saturation of rooms with natural light. The final assessment of the standardized parameters of natural lighting in residential premises is carried out using methods of psychophysics, which can connect the main and secondary factors affecting the comfort of the light environment.

1. Gusev N.M. Fundamentals of building physics. Textbook for high schools // Textbook for high schools, architecture speciality, M. Stroyizdat,1975, 440p.
2. Gusev N.M., Kireev N.N. Lighting of industrial buildings // M. Stroyizdat,1968, 160 p.
3. SNiP P-A.4–79. Natural and Artificial Lighting // Building Norms and Rules. GOSSTROY of the USSR, M. Stroyizdat, 1979.
4. Muravyova N.A., Solovyov A.K. The system for determining the required parameters of the natural light environment in the premises by the criterion of saturation with natural light // Scientific Review, 2013, № 9, pp. 132–137.
5. Stanislav D. Review of the Current State and Future Development in Standardizing Natural Lighting in Interiors // Light & Engineering, 2018, Vol. 26, # 4, pp. 5–26.
6. Darula Stanislav, Kittler Richard. Classification of Daylight Conditions in Cloudy covered Situations // Light & Engineering, 2015, Vol. 23, # 1, pp. 4–15.
7. Perrez R., Seals R., Michalsky J. All weather for sky luminance distribution – Preliminary configuration and validation.// Solar Energy, 1993, V.13, # 4, pp. 235–245.
8. Littlefair P.J. The luminance distribution of the average sky // Lighting Research and Technology, 1998, V.13, #4, pp. 192–198.
9. Nakamura H., Oki M., Hayashi Y. Luminance distribution of the intermediate sky. // Journal of Light and Visual Environment, 1985, V.9, # 1, pp. 6–13.
10. NIISF Gosstroy of the USSR. A guide to the calculation and design of natural, artificial and combined lighting (to SNiP P‑4–79), M. Stroyizdat, 1985.
11. Alexei K. Solovyov and Guofu Bi. Selection of the Area of Window Openings of Residential Buildings in Conditions of Monsoon Climate of the Far East of the Russian Federation and Northern Areas of China// Light & Engineering, 2019, Vol. 27, # 6, pp. 27–33.
12. SNiP P-A .6–72. “Construction climatology and geophysics.” Building regulations. GOSSTROY of the USSR, M. Stroyizdat, 1973 (used as a reference).
13. A reference book for the design of electric lighting. Edited by G.M. Knorring. Leningrad, Publishing house “Energy”, 1976.
14. Helson H. Adaptation Level Theory. New York: Harper, 1964.
15. Nina A. Muraviova, Alexei K. Soloviev, and Stetsky Sergei V. Comfort Light Environment under Natural and Combined Lighting: Method of Their Characteristics Definition with Subjective Expert Appraisal Using// Light & Engineering, 2018, Vol. 26, # 3, pp. 124–131.
16. Solovev Alexey K. Die Anvendung der Lichtfeldtheorie bei der Proektierung der Beleuchtung von Arbeitstaetten. // Licht, 1996, # 5, pp. 442–446.

In this paper, we analysed and implement clear sky and array performance models to achieve maximum electrical energy produced from the photovoltaic (PV) panel. The selected models just not only include location dependent parameters but also include environmental factors such as Linke Turbidity (include aerosols, absorption due to assorted gases, Rayleigh scattering), cloud cover, albedo, perceptible water vapour. 250 W PV panel was used as a reference to check the output electrical energy in a given location by inputting the latitude and longitude of a location. It is concluded that 27° facing south is the optimized tilt angle for every locations having latitude at north direction and longitude at east direction. By taking the example of location Nagpur India (21.14° N, 79.08° E), a difference of only 0.35 % is reported when comparing the computed electrical energy with actual electrical energy that have been acquired by using pyranometers, pyrheliometers and illuminance meters installed by the National Renewable Energy Laboratory (NREL). So, a good approximation of electrical energy can be computed by combining clear sky and array performance models.

1. Schiermeier Q, Tollefson J, Scully T, Witze A, Morton O. Energy alternatives: Electricity without carbon// Nature News, 2008, Aug 13, Vol. 454 (7206), pp. 816–823.
2. Ulfat I, Javed F, Abbasi FA, Kanwal F, Usman A, Jahangir M, Ahmed F. Estimation of solar energy potential for Islamabad, Pakistan// InTerragreen 2012: Clean Energy Solutions for Sustainable Environment (CESSE), Elsevier, 2012, Vol. 18, pp. 1496–1500.
3. Li D.H., Lam J.C. Measurements of solar radiation and illuminance on vertical surfaces and daylighting implications// Renewable energy, 2000 Aug 1; Vol. 20, #4, pp. 389–404.
4. Xu C.Y., Singh V.P. Dependence of evaporation on meteorological variables at different time‐scales and intercomparison of estimation methods// Hydrological processes, 1998, Mar 15, Vol. 12, #3, pp. 429–42.
5. Ineichen P., Guisan O., Perez R. Ground-reflected radiation and albedo// Solar Energy, 1990, Jan.1, Vol. 44, # 4, pp. 207–214.
6. Yu C., Khoo Y.S., Chai J., Han S., Yao J. Optimal orientation and tilt angle for maximizing in-plane solar irradiation for PV applications in Japan// Sustainability, 2019, Jan., Vol. 11, #7, p. 2016.
7. Khoo Y.S., Nobre A., Malhotra R., Yang D., Rüther R., Reindl T., Aberle A.G. Optimal orientation and tilt angle for maximizing in-plane solar irradiation for PV applications in Singapore// IEEE Journal of Photovoltaics, 2013 Dec. 12, Vol. 4, #2, pp. 647–53.
8. Benghanem M. Optimization of tilt angle for solar panel: Case study for Madinah, Saudi Arabia// Applied Energy, 2011 Apr. 1, Vol. 88, #4, pp. 1427–33.
9. Skeiker K. Optimum tilt angle and orientation for solar collectors in Syria// Energy Conversion and Management, 2009 Sep. 1, Vol. 50, #9, pp. 2439–2448.
10. Noia M., Ratto C.F., Festa R. Solar irradiance estimation from geostationary satellite data: I. Statistical models// Solar Energy,1993, Dec. 1, Vol. 51, #6, pp. 449–456.
11. Ineichen P., Perez R. A new air mass independent formulation for the Linke turbidity coefficient// Solar Energy, 2002, Sep. 1, Vol. 73, #3, pp. 151–157.
12. Duffie J.A. and Beckman W.A., Worek W.M. Solar Engineering of Thermal Processes// Wiley: New York, USA, 2003, Vol. 116.
13. Marion B. A model for deriving the direct normal and diffuse horizontal irradiance from the global tilted irradiance// Solar Energy, 2015, Dec. 1, Vol. 122, pp. 1037–1046.
14. Reno M.J., Hansen C.W., Stein J.S. Global horizontal irradiance clear sky models: Implementation and analysis// SANDIA report, SAND2012–2389. 2012 Mar.
15. Mellit A., Kalogirou S.A., Shaari S., Salhi H., Arab A.H. Methodology for predicting sequences of mean monthly clearness index and daily solar radiation data in remote areas: Application for sizing a stand-alone PV system// Renewable Energy, 2008, Jul. 1, Vol. 33, # 7, pp. 1570–1590.
16. Klucher T.M. Evaluation of models to predict insolation on tilted surfaces// Solar energy, 1979, Jan. 1, Vol. 23, # 2, pp. 111–114.
17. Liu B.Y., Jordan R.C. The long-term average performance of flat-plate solar-energy collectors: with design data for the US, its outlying possessions and Canada// Solar energy, 1963, Apr. 1, Vol. 7, # 2, pp. 53–74.
18. Perez R, Ineichen P., Seals R., Michalsky J., Stewart R. Modelling daylight availability and irradiance components from direct and global irradiance// Solar energy, 1990, Vol. 44, # 5, pp. 271–289.
19. Menicucci D.F., Fernandez J.P. Users manual for PVFORM: A photovoltaic system simulation program for stand-alone and grid-interactive applications// Sandia National Labs., Albuquerque, NM (United States); 1989 Oct 1.

The problem of development of the new profession of light designer primarily resides in development of the training methodology, cooperation of architects, lighting engineers, psychologists, colourists, social scientists in the sphere of education and their common understanding of importance of both artistic and technical design of lighting. Since the beginning of the 2000’s, the methodology for light design training has been created in Vladivostok, and the results of this work are presented in student projects and some theoretical projects, methodological and training guidelines and scientific articles. The methodology is based on contemporary examples and theory of light design in Russia and abroad; studying of media facades and light surfaces, lighting installations, light design of architectural ensembles; modelling of light panoramas of the city and areas of esplanades; training in the basics of light composition. The article describes the logic of the training process, which starts with creation of a light composition for modelling of the light panorama and lighting ensemble and forming of night time architectural and environmental spaces of the city, and methodology for light design in the sphere of architectural environment projects and education of light designers.

1. Discussion on the Problem of Light Design [Diskussiya po probleme svetovogo dizayna] // Svetotekhnika, 2018, # 3, pp. 72–82.
2. Discussion on the Problem of Light Design [Diskussiya po probleme svetovogo dizayna] // Svetotekhnika, 2018, # 4, pp. 80–93.
3. Discussion on the Problem of Light Design [Diskussiya po probleme svetovogo dizaiya] // Svetotekhnika, 2018, # 5, pp. 79–86.
4. Karpenko V.E. Light and Colour Modelling of Urban Environment: study guide for universities [Svetotsvetovoye modelirovaniye gorodskoy sredy: uchebnoye posobiye dlya vuzov] / Engineering School of FEFU, Vladivostok: Far East Federal University, 2019, 153 p. 1 CD, ISBN978–5–7444–4460–0.
5. Karpenko V.E., Lebedkova S.M., Ovcharov A.T., Sanzharov V.B., Silkina M.A., Snetkov V. Yu., Khadzhin A.G., Shchepetkov N.I. On the Subject of the Article by Bysrtyantseva N.V., Lekus E. Yu., Matveev N.V. Russian Light Engineering School: Strategies and Tactics [Po teme statyi Bystryantsevoy N.V., Lekus E. Yu., Matveeva N.V. Shkola otechestvennogo svetodizayna: strategii i taktiki] // Svetotekhnika, 2015, # 4, pp. 65–66.
6. Shlykova O.S. Problems of Arrangement of Lighting Environment of the Marine Esplanades of Vladivostok [Problemy organizatsii svetovoy sredy primorskikh naberezhnykh v g. Vladivostok] / Extended abstract of the Master Degree Thesis in the 07.04.03 Architectural Environment Design Programme, Urban Environment Planning profile. Vladivostok: FEFU, 2018, 31 p.
7. Karpenko V.E. Educational complex of light-coloured modelling of urban environment // SHS Web of Conferences. The 4th International Research-to-Practice Conference Lighting Design, 2017, St. Petersburg, Russia, 12–13 October, 2017, Vol. 43 (2018), 9 p. URL: https:// doi.org/10.1051/shsconf/20184301013 (date of reference: 15.02.2020).
8. Govan M., Kim C.Y. Turrell J. A Retrospective. Los Angeles, Country Museum of Art, Munich, London, New York: DelMonico Books. Prestel Verlag, 2013, 304 p.
9. Holzhey M, Vasarely V. 1906–1997. Pure Vision. Kὅln: Tashen, 2005, 96 p.
10. ITALIAN ZERO & avantgarde’60s. Cinisello Balsamo, Milano: Silvana Editoriale Spa. 2011, 288 p.
11. Orgeman K. Lumia: Thomas Wilfred and the Art of Light. New Haven: Yale University Art Gallery, 2017, 172 p.

Due to the intensification of historical buildings restoration works that are cultural monuments and related to architectural monuments, numerous questions arise about the possibility of increasing the efficiency of translucent structures, including their energy efficiency, using modern innovative technologies. The cost of competent reconstruction of windows and lanterns with the preservation of historical elements is much higher than the cost of standard modern structures, as a result of which there are numerous examples of barbaric illegal replacement of historical windows with modern ones. This not only spoils the appearance of buildings, but also contradicts federal laws (with all the ensuing consequences). Earlier, NIISF RAASN carried out multifactorial field studies of historical translucent coverings of a cultural monument of federal significance – the main building of the Pushkin Museum, on the basis of which their inconsistency with modern requirements for such structures was established. According to the technical assignment and the project for the reconstruction of the building, 13 options were proposed for the possible restoration of these coatings. To assess the proposed options, a comprehensive computer simulation and corresponding calculations were carried out in accordance with the certified software package “WINDOW TECT”. On the basis of the conducted examinations and computer calculations, optimal solutions were proposed for the restoration of historical translucent coatings of the main building of the Pushkin Museum, providing for the preservation of the original elements of metal structures and ensuring an increase in the thermal characteristics of the lantern and side lamp.

1. Alexander V. Spiridonov and Nina P. Umnyakova Inspection of the State (General and Instrumental) of Historical Translucent Structures of the Pushkin State Museum of Fine Arts// Light & Engineering, 2019, Vol. 27, # 3, pp. 26–31.
2. URL: https://tybet.ru/content/news/index.php? SECTION_ID=605&ELEMENT_ID=106288&sphrase_id=3536914 (date of the application: 07.06.2019).
3. URL: https://tybet.ru/content/news/index.php? SECTION_ID=605&ELEMENT_ID=99734&sphrase_id=3536942 (date of the application: 07.06.2019).
4. URL: https://tybet.ru/content/news/index.php? SECTION_ID=605&ELEMENT_ID=107525&sphrase_id=3536945 (date of the application: 07.06.2019).
5. URL: https://www.mk.ru/moscow/2018/11/12/vrossii-raskryta-set-makhinatorovrestavratorov.html (date of the application: 07.06.2019).
6. URL: https://tybet.ru/content/news/index.php? SECTION_ID=609&ELEMENT_ID=91395&sphrase_id=3536934 (date of the application: 07.06.2019).
7. URL: https://tybet.ru/content/news/index.php? SECTION_ID=374&ELEMENT_ID=100297&sphrase_id=3536936 (date of the application: 07.06.2019).
8. URL: https://tybet.ru/content/news/index.php? SECTION_ID=605&ELEMENT_ID=105548&sphrase_id=3536940 (date of the application: 07.06.2019).
9. URL: https://tybet.ru/content/news/index.php? SECTION_ID=605&ELEMENT_ID=105601&sphrase_id=3536939 (date of the application: 07.06.2019).
10. URL: https://tybet.ru/content/news/index.php? SECTION_ID=605&ELEMENT_ID=104754&sphrase_id=3536933 (date of the application: 07.06.2019).
11. URL: https://tybet.ru/content/news/index.php? SECTION_ID=605&ELEMENT_ID=106717&sphrase_id=3536918 (date of the application: 07.06.2019).
12. URL: https://tybet.ru/content/news/index.php? SECTION_ID=605&ELEMENT_ID=105486&sphrase_id=3536946 (date of the application: 07.06.2019).
13. URL: https://tybet.ru/content/news/index.php? SECTION_ID=605&ELEMENT_ID=98994&sphrase_id=3536938 (date of the application: 07.06.2019).
14. URL: https://tybet.ru/content/news/index.php? SECTION_ID=605&ELEMENT_ID=104966&sphrase_id=3536958(date of the application: 07.06.2019).
15. URL: https://tybet.ru/content/news/index.php? SECTION_ID=605&ELEMENT_ID=105915&sphrase_id=3536919 (date of the application: 07.06.2019).
16. URL: https://tybet.ru/content/news/index.php? SECTION_ID=605&ELEMENT_ID=103759&sphrase_id=3536931 (date of the application: 07.06.2019).
17. URL: https://tybet.ru/content/news/index.php? SECTION_ID=605&ELEMENT_ID=104669&sphrase_id=3536947 (date of the application: 07.06.2019).
18. URL: https://tybet.ru/content/news/index.php? SECTION_ID=605&ELEMENT_ID=99820&sphrase_id=3536957 (date of the application: 07.06.2019).
19. URL: https://tybet.ru/content/news/index.php? SECTION_ID=605&ELEMENT_ID=105548&sphrase_id=3536940 (date of the application: 07.06.2019).
20. URL: https://tybet.ru/content/news/index.php? SECTION_ID=606&ELEMENT_ID=99645&sphrase_id=3536920 (date of the application: 07.06.2019).
21. URL: https://tybet.ru/content/news/index.php? SECTION_ID=605&ELEMENT_ID=106122&sphrase_id=3536943 (date of the application: 07.06.2019).
22. Boriskina I.V., Isaikin A.S., Balakina A.E. Modern Windows for Historical Buildings and Architectural Monuments [Sovremennue okna dlya istoricheskikh zdani i pamyatnikov arkhitektyru]//St. Petersburg, 2019, 145 p.
23. Khalil А.M.R. et al. Implementing Sustainability in Retrofiting Heritage Buildings. Case Study: Villa Antoniadis, Alexandria, Egypt // Heritage, 2018, Vol. 1, # 1, pp. 57–87.
24. Alexander V. Spiridonov, Nina P. Umnyakova, and Valkin Boris L. Examination of Condition of Historical Transparent Structures of the Pushkin State Museum of Fine Arts// Light & Engineering, 2020, Vol. 28, # 1, pp. 63–69.
25. “Comprehensive reconstruction, restoration and adaptation to modern museum technologies of the main building of the State Museum of Fine Arts named after A.S. Pushkin (Moscow, Volkhonka str., 12)” (documentation prepared by the Federal State Unitary Enterprise “Central Scientific and Restoration Design Workshops”).
26. User manual for the “WINDOW-TECT” software package as part of the “THERM”, “WINDOW” programs. M.: APROK-TEST, 2006, 140 p.
27. Alexander V. Spiridonov and Umnyakova Nina P. Computer Modelling and Recommendations for Restoration of the Historical Translucent Structures of the Pushkin State Museum of Fine Arts// Light & Engineering, Vol. 27, # 6, pp. 58–64.
28. Scientific and technical report of NIISF RAASN on the topic: “Thermal calculations of the zone of the translucent coating of the object” Complex reconstruction, restoration and adaptation to modern museum technologies of the main building of the State Museum of Fine Arts named after A.S. Pushkin “. – M., 2018. – 88 p.
29. SP 131.13330.2012 “Construction climatology. Updated edition of SNiP 23–01–99 “.
30. GOST 26602.1–99 “Window and door blocks. Methods for determining resistance to heat transfer”. 31. GOST R54861–2011 “Windows and external doors. Methods for determining resistance to heat transfer”.
32. SP 50.13330.2012 “Thermal protection of buildings”, Updated edition of SNiP 23–02–2003 (with Amendment No. 1).
33. Scientific and technical report of NIIOSP named by N.M. Gersevanov on the topic “Complex reconstruction, restoration and adaptation to modern museum technologies of the main building of the State Museum of Fine Arts named after A.S. Pushkin (Moscow, Volkhonka st.,12), Vol. 4. Results of inspection of metal skylights of the building”, Moscow, 2015, 460 p.
34. Scientific and technical report of the Research Center “Construction” “On the corrosion resistance of existing bearing structures of the coating”. Volume 3, 2018, 109 p.

1. Technical regulation of the Customs Union “On the safety of low-voltage equipment” (TR CU004/2011) (as amended on December 9, 2011). URL: http://www.docs.cntd.ru/document/902299536 (accessed: 01/10/2020).
2. Technical regulations of the Customs Union “Electromagnetic compatibility of technical means” (TR TS020/2011). URL: http://www.docs.cntd.ru/document/ 902320551 (accessed: 01/10/2020).
3. Technical regulation of the Eurasian Economic Union “On the restriction of the use of hazardous substances in electrical products and radio electronics” (TR EEU037/2016). URL: http://docs.cntd.ru/document/420387089 (accessed: 01/10/2020).
4. Directive 2011/65 / EU RoHS of the European Parliament and of the Council of June 8, 2011 on the restriction of the use of certain hazardous substances in electrical and electronic equipment (EU Directive 2011/65 / EU RoHS of the European Parliament and of the Council of the EU dated June 8, 2011 to limit the content of harmful substances in electrical and electronic equipment). URL: http://www.schmidt-export.ru/sites/default/files/pdf/ce_cert/2011–65_rohs-en.pdf (accessed: 01.10.2020).
5. Technical regulation of the Eurasian Economic Union “On requirements for the energy efficiency of energy-consuming devices” (TR EAEU048/2019). URL: http://docs. cntd.ru/document/564066230 (accessed: 01/10/2020). 6. Treaty on the Eurasian Economic Union (Astana, May 29, 2014) with comparisons and additions. URL: https://base.garant.ru/70670880/ (accessed 03.03.2020).
7. Regulation (EU) 2017/1369 of the European Parliament and of the Council of 4 July 2017 setting a framework for energy labelling and repealing Directive 2010/30 / EU (Regulation (EU) 2017/1369 of the European Parliament and of the Council of 4 July 2017, setting the framework for energy labelling and repealing Directive 2010/30 / EU) // Official Journal of the European Union, 07.28.2017, L 198, pp. 1–24.
8. Directive 2010/30 / EU of the European Parliament and of the Council of 19 May 2010 on the indication by labelling and standard product information of the consumption of energy and other resources by energy-related products (the indication Directive labeling and in standard product information, information on energy consumption of energyconsuming products and other resources) // Official Journal of the European Union, 06.18.2010, L 153, pp. 1–12.
9. Commission Delegated Regulation (EU) No 874/2012 of 12 July 2012 supplementing Directive 2010/30 / EU of the European Parliament and of the Council with regard to energy labelling of electrical lamps and luminaires (Delegated Regulation supplementing Directive 2010/30 / EU regarding the energy labeling of electric lamps and luminaires) // Official Journal of the European Union, 09.26.2012, L 258, pp. 1–20.
10. Abrashkina M.L., Sysoeva E.A. Requirements for Energy Efficiency, Labelling and Eco-Design of Lighting Products: European Experience // Light & Engineering, 2017, Vol. 25, # 4, pp. 130–133.

The article describes the results of comprehensive study aiming at increase of quality of LED luminaires and definition of the nature of changes in their correlated colour temperature (CCT) in the course of operation. Dependences of CCT of LED luminaires with remote and close location of phosphor for 10 thousand hours of operation in different electric modes were obtained; the results of comparison between the initial and final radiation spectra of the luminaires are presented; using mathematical statistics methods, variation of luminaire CCT over the service period claimed by the manufacturer is forecast; the least favourable electric operation modes with the highest CCT variation observed are defined. The obtained results have confirmed availability of the problem of variation of CCT of LED luminaires during their operation. Possible way of its resolution is application of more qualitative and therefore expensive LEDs with close proximity of phosphor or LEDs with remote phosphor. The article may be interesting both for manufacturers and consumers of LED light sources and lighting devices using them.

1. Chervinsky M. Failures of LED Luminaires: Causes and Prevention Methods [Otkazy svetodiodnykh svetilnikov: prichiny i sposoby preduprezhdeniya] // Sovremennaya svetotekhnika, 2015, # 4, pp. 42–52.
2. Nikiforov S.G. Relevance of Study and Necessity of Development of the Methods of Studying Degradation of Parameters of LED Based on Solid Solutions of AlGaInP and AlGaInN [Aktualnost izucheniya i neobkhodimost sovershenstvovaniya metodik issledovaniya degradatsii parametrov svetodiodov na osnove tvyordykh rastvorov AlGaInP i AlGaInN] // Poluprovodnikovaya svetotekhnika, 2012, # 15, pp. 36–37.
3. STO 69159079–01–2018 LED Luminaires.Technical and operational specifications: Requirements.
4. Nikiforov S.G. Development of Measurement Means and Methods of Control of Parameters of Semiconductor Emitters Based on AIIIBV Compounds Applied in High-Reliability Instruments [Razrabotka sredstv izmereniy i metodov kontrolya parametrov poluprovodnikovykh izluchateley na osnove soyedineniy AIIIBV, ispolzuemykh v vysokonadyozhnykh priborakh] / Extended abstract of Dr. Tech. Sci. (Eng.) Dissertation. Moscow, 2015, 39 p.
5. ANSI C78.377–2017 “American National Standard for Electric Lamps – Specifications for the Chromaticity of Solid State Lighting (SSL) Products”.
6. Liu Z., Yang B., Zhang C.E., Li Y., Zou J., Shi M., Qian X., Zheng F. Model prediction on the correlated color temperature of white LED based on chromaticity coordinate // Journal of Luminescence, 2019, Vol. 216, № 116652.
7. Lin D., Zheng P., He G. Color temperature tunable white LED cluster with color rendering index above 98 // EEE Photonics Technology Letters, 2017, Vol. 29, #12, pp. 1050–1053.
8. Kapitonov S.S., Prytkov S.V., Grigorovich S. Yu., Kapitonova A.V., Medvedev S.A., Slugina N.P. The Study of Variation of Colour Temperature and Radiation Spectrum of LED Luminaires over the Course of their Operation [Issledovaniye izmeneniya tsvetovoy temperatury i spektra izlucheniya svetodiodnykh svetilnikov v protsesse ikh ekspluatatsii] // Nauchno-tekhnicheskiy vestnik Povolzhya, 2019, Vol. 1, pp. 84–87.
9. Huang Y.-S., Luo W.-C., Wang H.-C., Feng S.-W., Kuo C.-T., Lu C.-M. How smart LEDs lighting benefit color temperature & luminosity transformation // Energies, 2017, Vol. 10, # 4, p. 518.
10. Bespalov N.N., Ilyin M.V., Kapitonov S.S. Testing equipment for LED luminaire control devices and fluorescent lamp electron ballasts [Oborudovaniye dlya ispytaniy upravlyayushchikh ustroystv dlya svetilnikov so svetodiodami i EPRA dlya lyuminestsentnykh lamp] // Svetotekhnika, 2017, # 4, pp. 42–46.
11. Bespalov N.N., Ilyin M.V., Kapitonov S.S. Testing equipment for LED luminaire control devices and fluorescent lamp electron ballasts // Light & Engineering, 2017, Vol. 25, #4, pp. 86–91.

In recent years, smart road lighting (SRL) design and application researches has been increasing rapidly. However, SRL applications remain pilotproject and cannot become widespread sufficiently. Main reason for this is that, although the cost of production of LED luminaires is reduced, when existing road lighting systems are transformed to LED road lighting, existing electrical installations and lighting poles cannot be used. Increased investment costs due to electrical installation and poles renovation, decrease interest in SRL transformation. In this study, an innovative solution is developed to decrease the costs of the SRL. First, a new LED luminaire is designed, which can work without changing the installations and poles of the existing projects. Then a test road is created using DIALux software, and the newly designed lighting installation is compared with completely redesigned one and conventional road lighting. Thus, contributions are provided for spreading of the SRL transformation, using low cost SRL approach.

1. L. Atzori, A. Iera, G. Morabito, The internet of things: A survey. Computer networks, Computer Networks, 2010. V54, #15, pp. 2787–2805.
2. A. Adriansyah, A.W. Dani, G.I. Nugraha Automation control and monitoring of public street lighting system based on internet of things, In 2017 International Conference on Electrical Engineering and Computer Science, Palembang, 2017, pp. 231–236.
3. T. H. Do, M. Yoo An in-depth survey of visible light communication based positioning systems, Sensors, 2016. V16, #5, p. 678.
4. L. Tähkämö, R.S. Räsänen, L. Halonen Life cycle cost comparison of high-pressure sodium and light-emitting diode luminaires in street lighting, International journal of life cycle assessment, 2016. V21, #2, pp. 137–145.
5. A. Gil-de-Castro, A. Moreno-Munoz, A. Larsson, J. J.G. De La Rosa, M. H.J. Bollen LED street lighting: a power quality comparison among street light technologies, Lighting Research & Technology, 2013. V45, # 6, pp. 710–728.
6. G. Shahzad, H. Yang, A.W. Ahmad, C. Lee Energyefficient intelligent street lighting system using trafficadaptive control, IEEE Sensors Journal, 2016. V16, #13, pp. 5397–5405.
7. J. F. De Paz, J. Bajo, S. Rodríguez, G. Villarrubia, J.M. Corchado Intelligent system for lighting control in smart cities, Information Sciences, 2016. V372, pp. 241–255.
8. Ö. Gül, Ö. Sen, Technical and Economical Evaluation of LED Road Lighting in Turkey, Light & Engineering, 2010. V18, #4, pp. 29–36.
9. C.C.D. Fonseca, R.P. Pantoni, D. Brandão Public street lighting remote operation and supervision system, Computer Standards & Interfaces, 2015. V38, pp. 25–34.
10. Road Lighting Calculations, CIE140–2000, 2000.
11. P. T. Daely, H.T. Reda, G.B. Satrya, J.W. Kim, S.Y. Shin Design of smart LED streetlight system for smart city with Web-based management system, IEEE Sensors Journal, 2017. V17, #18, pp. 6100–6110.
12. TEDAŞ. (2019, March). LED’li Yol Aydınlatma Tasarımına İlişkin Usul ve Esaslar [Online]. Available: http://www.tedas.gov.tr/uploads/LEDliYolAydinlatma%20TasariminaIliskinUsulveEsaslar%20(Taslak).pdf
13. National Electrical Manufacturers Association. (2014, July). Energy Savings with Fluorescent and LED Dimming [Online]. Available: https://www.nema.org/Standards/SecureDocuments/NEMALSD%2073–2015 %20WATERMARKED.pdf
14. Time and Date. (2019). World Clock [Online]. Available: http://www.timeanddate.com/worldclock/astronomy.html
15. Yandex. (April, 2018). İstanbul Trafik Analizi [Online]. Available: https://yandex.com.tr/company/press_center/infographics/istanbul_traffic

In this research, the change in the junction temperature and luminous flux of a new generation LED module depending on variables such as radiation, lens piece, ambient temperatures, currents, and quantity of elements had been studied. Commercial software FloEFD2019 was used in the finite volume analysis made during the study. The analyses were verified by experiments. On basis of the analysis, a solution was obtained that does not depend on the number of elements. The force of gravity was taken into account. While the ambient temperatures were taken as Ta = 23 °C and 40 °C, and the radiation value as 1009 W/m2, currents as 140 mA, 160 mA, 180 mA, 200 mA, 220 mA and 240 mA, meanwhile, samples numbers on PCB were taken as 101 and 202. In order to determine the effect of the lens piece located on the LED module, the analysis was repeated with and without using the lens. As a result of the study, it was found that the increase in ambient temperature and radiation has an adverse effect on the temperature Tj and luminous flux. It has been observed that changing samples number has a negligible effect on luminous flux and temperature Tj. It was found that the use of radiation and lenses are the most important factors affecting the luminous flux of the module.

1. Rosenberg E., Fidje A., Espegren K.A., Stiller C., Svensson A.M., Moller-Holst S. Market penetration analysis of hydrogen vehicles in Norwegian passenger transport towards 2050. International Journal of Hydrogen Energy. 2010. V35, #14, pp. 7267–7279. doi:10.1016/j.ijhydene.2010.04.153
2. Poppe A., Lasance CJM. On the standardization of thermal characterization of LEDs. Annual IEEE Semiconductor Thermal Measurement Management Symposium, 2009. #2, pp. 151–158. doi:10.1109/STHERM.2009.4810757
3. Kikuchi K., Hamashiam Y., Kobayashi Y. Prediction of LED junction temperatures with CFD for headlamp application. In: ISAL Symposium Proceeding, 2005.
4. Senawiratne J., Zhao W., Detchprohm T., et al. Junction temperature analysis in green light emitting diode dies on sapphire and GaN substrates. Physica status solidi (c), 2008. V5, #6, pp. 2247–2249. doi:10.1002/pssc.200778648
5. Weber R. Calculating an LED’s Junction Temperature, 2015.
6. Application Guide, 2010.
7. Thermal Management of SMT LED Application Note, 2014.
8. Bider C. Effect of thermal environment on LED light emission and lifetime. LED Prof Rev May/June 2009, 2009.
9. Bielecki J., Jwania A.S., Khatib F. El., Poorman T. Thermal Considerations for LED Components in an Automotive Lamp. 23rd IEEE SEMI-THERM Symposium, 2007.
10. Rubenstein R.Y., Kroese D.P. Simulation and the Monte Carlo method, 2011.
11. Vora A.K., Vijaykumar P. Basic Thermal Guidelines for using PowerPSoC ®, 2009. #001, pp. 1–12.
12. Sheu G.-J. The heat dissipation performance of LED applied a MHP, 2005. p. 5941, 594113–594118. doi:10.1117/12.616355
13. Jen-Hau Cheng, Chun-Kai Liu, Yu-Lin Chao, Ra-Min Tain. Cooling performance of silicon-based thermoelectric device on high power LED. In: ICT 2005. 24th International Conference on Thermoelectrics, 2005. IEEE; 2005. pp. 53–56. doi:10.1109/ICT.2005.1519885
14. Arik M., Becker C.A., Weaver S.E., Petroski J. Thermal management of LEDs: package to system. Third Int Conf Solid State Light, 2004, 5187 (July 2014), 64. doi:10.1117/12.512731
15. Petroski J. Understanding longitudinal fin heat sink orientation sensitivity for Light Emitting Diode (LED) lighting applications. In: Advances in Electronic Packaging, 2003.
16. Yung K.C., Liem H., Choy H.S., Lun W.K. Thermal performance of high brightness LED array package on PCB. International Communications in Heat and Mass Transfer, 2010. doi:10.1016/j.icheatmasstransfer.2010.07.023
17. Zhong D., Qin H., Wang C., Xiao Z. Thermal performance of heatsink and thermoelectric cooler packaging designs in LED. In: Proceedings – 2010 11th International Conference on Electronic Packaging Technology and High Density Packaging, ICEPT-HDP 2010, 2010. doi:10.1109/ICEPT.2010.5582819
18. Cheng H.H., Huang D.S., Lin M.T. Heat dissipation design and analysis of high power LED array using the finite element method. Microelectron Reliab, 2012. doi:10.1016/j.microrel.2011.05.009
19. Weng C.J. Advanced thermal enhancement and management of LED packages. International Communications in Heat and Mass Transfer, 2009. doi:10.1016/j.icheatmasstransfer.2008.11.015
20. Lai Y., Cordero N., Barthel F., et al. Liquid cooling of bright LEDs for automotive applications. Applied Thermal Engineering, 2009. doi:10.1016/j.applthermaleng.2008.06.023
21. Raypah M.E., M.k. D, Devarajan M, Sulaiman F. Investigation on thermal characterization of low power SMD LED mounted on different substrate packages. Applied Thermal Engineering, 2016. doi:10.1016/j.applthermaleng.2016.02.092

Its self-heating process directly affects the optical performance and reliability of light – emitting diodes (LEDs). It is important to disperse the generated heat from LED to surrounding atmosphere and keep the LED light performances same as declared by the manufacturer. Thermal interface material (TIM) is applied in between sink and source to reduce contact resistance at the junction between substrate and heat sink interface of the LED modules. This paper provides an assessment on ‘thermal interface materials’. Here different TIM materials used and the performance and problems of these commercial interface materials are discussed. From this study, one can calculate the temperature distribution in the sink area for different types of TIM materials under thermal conductivity perspective and be able to find the capability of dissipation of heat at the end surfaces of heat sinks, and design their system as well. In another process, TIMs with different thickness and input drive currents for the COB-based LED are investigated by using COMSOL simulation software. The results show that the junction temperature of the LED luminaire increases and reduce the lifetime when the input drive current and thickness of the TIM layers increase.

1. N. Narendran, N. Maliyagoda, A. Bierman, R. Pysar and M. Overington. Characterizing White LEDs for General Illumination Applications, SPIE Photonics West Conference, San Jose, CA, SPIE paper 3938–39, Jan, 2000.
2. Mehmet Arika, Charles Beckerb, Stanton Weaverb and James Petroskic. Thermal Management of LEDs: Package to System, Third International Conference on Solid State Lighting, SPIE Vol. 5187, doi: 10.1117/12.512731(2004).
3. Guo-guang Lu, Ming-mingHao, Can-xiong Lai and Bin Yao. Thermal analysis and reliability evaluation on high power Flip chip LED, IEEE conference, China, ISBN: 978–1–5090–0175–0 (2015).
4. J.-M. Kang, J.-W. Kim, J.-H. Choi, D.-H. Kim, and H.-K. Kwon. Lifetime estimation of high-power blue light-emitting diode chips, Microelectron. Reliab. 49, 1231–1235 (2009).
5. M. Meneghini, A. Tazzoli, G. Mura, G. Meneghesso, and E. Zanoni. A review on the physical mechanisms that limit the reliability of GaN-based LEDs, IEEE Trans. Electron Devices 57, 108–118 (2010).
6. M. Meneghini, A. Tazzoli, G. Mura, G. Meneghesso, and E. Zanoni. A review on the physical mechanisms that limit the reliability of GaN-based LEDs, IEEE Trans. Electron Devices 57, 108–118 (2010).
7. B.-M. Song, B. Han, and J.-H. Lee. Optimum design domain of LEDbased solid state lighting considering cost, energy consumption and reliability, Microelectron. Reliab. 53, 435–442 (2013).
8. M. R. Krames, O.B. Shchekin, R. Mueller-Mach, G.O. Mueller, Ling Zhou, G. Harbers, and M.G. Craford. Status and Future of High-Power Light Emitting Diodes for Solid-State Lighting, J. Display Technol., 2007. V3, #2, p. 160.
9. Daren Alfred Lock, Simon R.G. Hall, A.D. Prins, B.G. Crutchley, S. Kynaston, and Stephen John Sweeney. LED Junction Temperature Measurement Using Generated Photocurrent, Journal of Display Technology, IEEE, May 2013. V9, #5.
10. Quan Chen, XiaobingLuo, Shengjun Zhou, and Sheng Liu. Dynamic junction temperature measurement for high power light emitting diodes, American Institute of Physics, Review of Scientific Instruments 82, 084904 (2011).
11. Chi-Yuan Lee, Ay Su, Yin-Chieh Liu, Wei-Yuan Fan and Wei-Jung Hsieh. In Situ Measurement of the Junction Temperature of Light Emitting Diodes Using a Flexible Micro Temperature Sensor, Sensors, 9, 5068–5075; ISSN1424–8220, 2009.
12. Minseok Ha, Samuel Graham. Development of a thermal resistance model for chip-on-board packaging of high power LED arrays, Microelectronics Reliability, 2012. V52, pp. 836–844.
13. A.E. Chernyakov et al. Theoretical and Experimental Study of Thermal Management in High-Power AlInGaN LEDs, IEEE Conference (EuroSimE2014), 978–1–4799–4790–4/14.
14. Kai HAN, Muqing LIU, Shenglong FAN, Haiping SHEN. Improved Electrical Measurement Method for Junction Temperature of Light Emitting Diodes, PRZEGLĄD ELEKTROTECHNICZNY (Electrical Review), ISSN0033–2097, R. 88 NR3b/2012.
15. Adam Christensen, Samuel Graham. Thermal effects in packaging high power light emitting diode arrays, Applied Thermal Engineering, 2009. V29, pp 364–371. doi:10.1016/j.applthermaleng.2008.03.019
16. A. Keppens, W.R. Ryckaert, G. Deconinck, and P. Hanselaer. High power light-emitting diode junction temperature determination from current-voltage characteristics, JOURNAL OF APPLIED PHYSICS104, 093104(2008).
17. JaroslavFreisleben, Tomas Dzugan, Ales Hamacek. Comparative Study of Printed Circuit Board Substrates used for Thermal Management of High Power LEDs, IEEE38th Int. Spring Seminar on Electronics Technology, 978–1–4799–8860–0, 2015.
18. Lisa Mitterhuber et al., “Investigation of the Temperature-Dependent Heat Path of an LED Module by Thermal Simulation and Design of Experiments”, IEEE Therminic 2016–22nd International Workshop, ISBN978–1–5090–5450–3, 2016.
19. Lu Guoguang, Yang Shaohuaa and Lei Zhifenga. Failure analysis of LEDs, IEEE2011 International Symposium on Advanced Packaging Materials (APM 2011), 978–1–4673–0149–7/11, 2011.
20. Y.C. Hsu et al. Failure Mechanisms Associated with Lens Shape of High-Power LED Modules in Aging Test, IEEE LEOS2007, 1092–8081, 2007.
21. Ghosh K, Raul D. Performance analysis of various types of high power light emitting diodes, Light and Engineering, 2018. V26, #1, pp. 91–98. doi.org/10.33383/2017–045.
22. D Raul and K Ghosh. Performance of chipon-board and surface-mounted high-power LED luminaires at different relative humidities and temperatures, Lighting Research & Technology, 2018. doi:10.1177/1477153518819040.
23. Integrated Circuits Thermal Test Method Environmental Conditions – JEDEC Solid State Technology Association – JESD51–2A, January 2008.
24. F.-K. Wang and T.-P. Chu, “Lifetime predictions of LED-based light bars by accelerated degradation test”, Microelectron Reliability, July, 2012. V52, #7, pp. 1332–1336.