The article is considering some challenges, which occur in lighting and technology researches for a number of specific cases. These cases belong to the regions with sunny climatic conditions and include implementation of solar screening, clear sky conditions of outdoor daylighting with unobscured sun and principally preferred natural, or passive method of microclimate control within the interiors. The main idea of the studies conducted is to consider solar-screening devices as an additional mean of light reflection solar protection in form of screens, canopies or blinds, which act to prevent direct solar ray penetration into interiors and reduce overheating, glare, and contrasts. On the other hand, external solar protection increases the indoor levels of natural illumination due to the reflection of sunlight from sun protection structures. The conclusion is made, that such a scientific and design approach opened a new item in lighting research and technology, which can be called “supplementary daylighting of interiors”. Sun shading becomes really efficient only in conditions of hot and sunny climate. The emerging shortage in daylight in this case can be improved by additional daylight, reflected from the outer structures of sun-protecting devices. Such an approach to the design of the internal lighting environment makes it more comfortable, decreasing excessive brightness, contrast, and uneven daylight spreading character over the premise. There are several conclusions made on the materials of case and theoretical experiments. These conclusions proved the positive points of stationary sun protection not only as the screening structures, but as a mean of additional daylighting of interiors.

Physics-Informed Neural Networks (PINNs) provide a powerful framework for solving partial differential equations (PDEs) across various scientific and engineering disciplines. Unlike traditional numerical methods, PINNs do not require extensive expertise in the underlying numerical techniques of the target domain, making them accessible for a broader range of users. While PINNs have shown promise for solving forward and inverse problems, their performance relative to classical methods remains a topic of active investigation, particularly in radiative transfer applications. In this study, we assess the application of PINNs to a one-dimensional radiative transfer equation. Through simple test cases, we evaluate their strengths and limitations compared to the discrete ordinate method. Our findings indicate that PINNs can achieve an error as low as 0.3 % within several minutes of computation, whereas traditional solvers are significantly faster. However, the ease of implementation and the ability of PINNs to address inverse and high-dimensional problems highlight their potential as a complementary approach, particularly for complex scenarios.

The review focuses on the evolution of views on the mechanisms of human colour perception in context of a gradual study of the spectral characteristics of light, the physiology and psychology of the visual mechanism, and the decoding of the functional features of retinal sensors and other neural groups throughout the visual pathway. The first part of the review presents historical information on the various stages of the development of views on the nature of colour vision not only from the perspective of natural science hypotheses provided by scientists, but also regarding the subjective opinions of representatives from the arts-artists and poets. The review briefly outlines concepts of ancient chromatism and medieval metaphysics of colour and continues with the first rational theories of colour perception, providing more detailed discussions on the views of Isaac Newton and Mikhail Lomonosov, Johann Goethe and John Turner, Gaspard Monge and Hermann von Helmholtz, Arthur Schopenhauer and Erwin Schrödinger, James Maxwell, and Ewald Hering. The second and third parts of the review will sequentially examine the progress in understanding the operation of colour-coding neurons, their receptive fields, colour discrimination thresholds, and other aspects in relation to such effects as colour constancy, the relationship between the form of objects and their perceived colour, and various colour illusions. Recent intriguing results, obtained using molecular genetic methods, shed new light on the evolutionary transformations of colour vision in animals and humans. The review will show an impact of the major studies of deviations in colour perception on practically significant lighting solutions, discussion of the individualities of colour perception in virtual and augmented reality systems, as well as in context of various holographic technologies. Furthermore, the matter of museum lighting optimization and the production of specialized LED devices will be considered. Finally, the review presents the link between the latest achievements in the field of psychophysiology of colour perception and the spectral characteristics of light sources familiar to specialists in colourimetry and lighting technology.

The increase of lighting elements in a power system leads to a corresponding increase in power quality disturbances caused by these devices. When the number reaches hundreds, the distortions begin to affect medium voltage levels rather than low voltage. Outside of specified systems, such as street and outdoor illumination, the use of lighting elements varies widely depending on working conditions and individual or institutional behaviour. Therefore, for an accurate and functional power system planning, it is not enough to only measure the harmonics arising from lighting elements with variable characteristics, but also harmonic estimation is needed, which is also the main motivation of this study. According to this aim, in this study a real-world dataset obtained from a MV distribution system supplying mixed illumination installations used for forecasting of harmonics based on such devices. The analysis of the data set revealed that there is a correlation between current harmonics and voltage variations, so the algorithm was designed based on this relationship, since voltage is an easily measurable power system parameter. Combined AI models were used for forecasting to reach the best results. Forecasting performance is discussed by using numerical values and graphical expressions, where the MSE, RMSE and MAE, and SMAPE values are 1.2834, 1.11328, 0.8095, and 10.7692 respectively.

The market for lighting equipment that improves the quality of medical work is large. But it covers the needs of specialists for the most part only in peacetime. There are no specialized lamps for situations related to disaster medicine. There are also no systems that take into account the specifics of the work of doctors on the front line, although in the zone of localization of military conflicts the number of people in need of medical care is significantly increasing. It is necessary to develop special lighting equipment. The main goal of the work is the design concept with mainly researched user experience when creating a visual image of the system. The purpose of article is to show an approach to designing concepts of future lighting systems in design, which can become the basis for engineering development. The preceding stage of technical development of a new product that has no analogues is conceptual design. Its result is the concept of the future object. Creating a design begins with observing the target audience. This allows you to create basic user scenarios. In the case of the lighting system for mobile hospitals, we studied the specifics of the activities of doctors. It turned out that extreme conditions near the contact line affect the work of doctors and nurses. This requires a fundamentally new approach to the layout of the system elements. It becomes clear that it is necessary to implement the principle of modularity. The design methodology in industrial design allows you to understand exactly how to do this. An analysis of the scenarios of the work of military doctors has shown a number of problems they face in mobile hospitals in war zones. The main criteria of the future lighting system were derived. First, they were embodied in search sketches, and after checking them for ergonomics – in the final visualizations. The methods of design of lighting equipment made it possible to solve a number of tasks: – Ensuring the possibility of assembling the necessary set of fixtures due to a narrow typology of modules; – Achieving the greatest compactness of components so that 1–2 people can transfer their minimum set for the organization of one workspace; – Minimizing the risk of accidental errors in working with equipm

Power supply is an important part of the design of any lighting devices with light emitting diodes (LEDs), which provides stable operation of LEDs and, at the same time, stable electrical and lighting parameters of the lighting device as a whole. The purpose of this work was to create a model of the power supply circuit for a luminaire with LEDs and analyse its operation. Modelling of the circuit was carried out in the calculation for an allowable load of no more than 70 W. This value was chosen according to its versatility and the greatest demand in the market of power supplies for lighting devices with LEDs. The simulated circuit of the power supply source, based on the power factor corrector for a light device with LED using the program “Micro-Cap”, is presented in the article. The analysis of the circuit operation in working and emergency modes is carried out. The simulation results are presented in the form of graphs of the time dependence of the main circuit parameters. The principle of controlling the current of the LED and the purpose of functional units of the circuit and outputs of the microcircuit (type MS33262) are described. The purpose of each structural element used in the circuit is specified. The modelled circuit has a power factor which is at least 0.98. The protection device PS triggers normally and the power factor corrector together with the appropriate electronic harness provides stable operation of the circuit for a light device with a 70 W LED.

Reducing the Daylight Glare Probability (DGP) is one of the important tasks of increasing the comfort of daylighting and insolation, especially in industrial and public premises with long stays of people during working hours. A method has been developed for modelling the DGP in a room with smart window with built-in grating optical filter having angular-selective light transmission. New equations have been obtained for calculating the diffuse light transmittance, vertical illuminance, and luminance in such rooms. Numerical simulation has been carried out to determine the parameters of the filter gratings, the temporal characteristics of light transmission, and to calculate the DGP at 12 points of the room. The proposed grating chromogenic smart window has minimal transmission at a designated time, in contrast to a conventional chromogenic smart window with a continuous surface coating and a conventional uncoated window, the transmittance of which changes only due to reflection and absorption losses depending on the incidence angle of the solar rays. The diffuse light transmittance of a grating chromogenic window is higher than that of a conventional chromogenic window in both coloured and bleached states, which increases daylight during months with insufficient solar radiation. The results of the DGP calculation showed that the best anti-glare performance is provided by the grating chromogenic smart window, intermediate by the conventional chromogenic smart window, and the worst by the conventional uncoated window. The developed method for modelling the glare probability is applicable to assess not only DGP, but also any other metrics of discomfort.