The widespread use of modern light sources, particularly light emitting diodes (LEDs), creates requirements related to lighting quality that demand new approaches for their solution. One of the key aspects is ensuring the colour uniformity of radiation from luminaires based on LEDs. Currently, colour uniformity is achieved through binning, that is sorting LEDs according to their chromaticity coordinates (x, y) in the CIE 1931 colour space. However, binning according to current standards does not yield the necessary effect; differences in chromaticity are still observed, which forces LED manufacturers to independently develop and apply alternative binning approaches. Furthermore, the current binning method does not account for the influence of luminance and chromatic adaptation on the perception of LED chromaticity. The foundation of LED binning is the colour threshold-the minimum difference in colour that an observer can notice. This work investigates the influence of adaptation luminance on colour thresholds and compares the obtained data with results calculated using the main models of colour perception: CIECAM02, CIECAM16, and the colour sensation model VRVGVB. These models account for the adaptation mechanisms of vision, allowing for more accurate prediction of colour perception under various lighting conditions. The research results can be useful for developing advanced LED binning methods that ensure high colour uniformity.
Light pipes are one of the most effective methods for transmitting daylight into deep interior spaces. To adapt to complex building structures, it is recommended to use one or more elbows to redirect the light. However, it is essential to determine the light losses caused by adding elbows to the system, especially when compared to straight pipes of the same length. This study primarily aims to test different elbow configurations on light pipes. Additionally, it seeks to evaluate the efficiency trends associated with varying lengths of both straight and elbowed light pipes under the same configuration. Validated simulation tools and plugins, known for their accuracy, are employed as the primary method in this analysis. The core software suite includes Rhinoceros for 3D modelling, Grasshopper for algorithmic graphic editing, and Ladybug and Honeybee plugins for daylight simulation. Different configurations were analysed under clear and overcast sky conditions, based on maximum and average illuminance levels on the working plane. The results revealed that straight pipes with a short aspect ratio provided the highest levels of illuminance but caused glare on the working plane under clear sky conditions. For double-elbowed pipes, light losses increased significantly with pipe length compared to other typologies. But it was found that under clear sky conditions and in spaces where lower illumination levels are sufficient, the system performs adequately when the light transmission direction is deliberately altered.
Intelligent systems for monitoring microclimate parameters represent a promising and rapidly evolving segment of the Russian market for measuring equipment. Their use is legally mandated in certain spheres. Strategic placement of sensors optimized using microclimate parameter maps and artificial intelligence enables efficient monitoring and analysis of temperature, humidity, light intensity, and other parameters based on large volumes of data. The objective of this study is to develop and test a microclimate monitoring system suitable for practical application in museums, exhibition spaces, and libraries. The presented system employs microclimate mapping and AI algorithms for monitoring and maintaining optimal conditions for the preservation and display of valuable objects. Particular attention is paid to monitoring UV irradiance and illuminance. Museum climatology classifies these parameters as microclimate, as they are critical to the preservation of exhibits and require special attention in lighting design and technology. The process of mapping microclimate parameters within museum, exhibition, and archive spaces involves several stages, including the examination of design documentation, the layout of engineering systems, and the specific characteristics of exhibits, particularly their sensitivity to light. The next step involves scanning the premises with measuring equipment. The collected data is then analysed and visualized as maps, illustrating the distribution of microclimate parameters within the room layout. This allows for the identification of problem areas and the imple mentation of measures to address them. For reliability and reduced time costs in analysing and constructing microclimate parameter distribution maps, it is advisable to employ AI algorithms. The article is dedicated to a new intelligent system developed to enhance the efficiency of specialists responsible for the preservation of exhibits. The results of the methodology validation and preliminary data from a pilot study are presented, confirming that the system significantly improves awareness and increases the accuracy of microclimate control.
Currently, the range of LED retrofitting lamps is constantly expanding. The aim of this study is to investigate the influence of the design of optical elements within the optical system of LED lamps on their photometric characteristics. Seven samples of LED lamps, incorporating secondary lens-type optical elements responsible for forming the light distribution curve, were used as test objects. Four samples featured a candle-shaped bulb, while three had a globe-shaped bulb. The photometric characteristics (luminous flux, power, correlated colour temperature, luminous intensity distribution curve, and luminous efficacy) of these samples were determined and compared with the manufacturers' specifications. As a result, it was demonstrated, in particular, that the luminous intensity distribution curve depends on both the bulb design and the lens design of the LED lamp. An analysis of the lens designs identified the mechanism of light distribution formation. The dependence of the luminous flux reduction level caused by the lens on its design was examined. It was shown that the luminous intensity distribution curve of an LED lamp depends on the specific features of these optical elements and the position of the LEDs relative to the lamp's lens.
In this work, the modelling and Real-Time Implementation of a Photovoltaic (PV) System, are performed. This PV system is composed by a Solar PV Panel, a DC-DC boost converter and the resistive load. This DC-DC converter is controlled by a Maximum Power Point Tracking (MPPT) controller employing Perturb and Observe (P&O) or Incremental Conductance (IC) algorithm. This DC-DC boost converter is controlled via the Pulse Width Modulation (PWM) signal, generated from the employed Arduino card (as an output of this card). The modelling of this PV system is performed under ISIS. The implementation of IC or P&O algorithm is performed using this card.
This article explores the importance of energy performance contracts as a key tool for improving energy efficiency, demonstrating their special role in today's economic and legal environment. The author identifies and analyses in detail the shortcomings of the current legislative definition of an energy performance contract, noting that the ambiguity and limitations of the regulatory definition have created legal uncertainty, contributing to conflicts between private and public interests, particularly in the context of government procurement. This paper substantiates the position that an energy performance contract, by its very nature, represents a special contractual structure, as energy performance activities can be implemented within contracts with various purposes-supply, contracting, leasing, and rental. The paper also substantiates the position on the need for legislative amendments to the definition of an energy performance contract. The article demonstrates that the proposed changes to the definition of an energy performance contract could create a more predictable and favourable regulatory environment for lighting equipment manufacturers. Shifting the emphasis from "actions aimed at energy conservation" to the civil law result (delivery of goods, performance of work, provision of services) removes the artificial narrowing of the contract to a contract for the provision of services for fee and legitimizes the diversity of models, within which lighting modernization projects are actually
Southern Algeria is distinguished by severe climatic conditions, notably persistent strong winds and extreme temperatures. These environmental factors frequently cause malfunctions in smart street lighting systems, leading to operational downtime that adversely affects the daily lives of citizens. During pilot testing of a smart street lighting system on a university campus, two critical challenges were identified: strong winds and heavy rainfall, both of which forced the system to suspend operation due to reduced performance under such conditions. To mitigate these issues, two deep learning models-Long Short-Term Memory (LSTM) and Convolutional Neural Network-LSTM (CNN-LSTM)-were trained and evaluated using a univariate dataset comprising only historical power output. The primary objective was to design a control strategy capable of dynamically regulating power levels to improve the system's resilience to environmental variability. The findings indicate that both models delivered robust predictive performance; however, the LSTM model achieved superior accuracy compared to the CNN-LSTM, highlighting its effectiveness in optimizing smart street lighting systems under extreme climatic conditions while simultaneously promoting energy efficiency.
Experimental studies of the method of detection of oil pollution on the earth's surface in the near-in-frared range at different projective soil coverages by vegetation were carried out. It has been shown that with the increase of the projective coverage of vegetation, the spectral dips caused by absorption of radiation by oil pollution on the surface become less visible in the reflection spectra (both about 1.73 mu m and 2.3 mu m). However, when projective coverage of vegetation is even similar to 60 % these spec-tral dips are still visible and it is possible to detect contamination of the soil with petroleum products. With a very large (similar to 100 %) projective coverage of the soil by the grass, the spectral dips caused by the absorption of radiation by oil pollution on the sur-face disappear almost completely and the probabil-ity of detecting soil contamination by oil products becomes very low. The best methods for detecting oil contamination in grass cover conditions is using a hydrocarbon index and using 20 spectral channels with a width of 10 nm in range (1.6-1.8) mu m and 29 spectral channels with a width of 10 nm in the range (2.1-2.39) mu m.
A1iming to realize the demand of healthy, comfortable, biorhythms, personalized and adaptive lighting environments, human-centric lighting has become hot-spots issue. Fortunately, Large Language Model (LLM) technology have already presented its prominent advantages and great application prospect in many fields. This paper proposes a novel indoor lighting control framework with context-aware-based LLM and domain knowledge base. The multi-source information perception, fusion and decision-making mechanism is established, which collects occupant behaviour and environment parameter, and enable dynamic modelling of lighting environment and indoor lighting intelligent control. The domain knowledge base is constructed by integrating national standard files in the field of lighting, and also Building Information Model (BIM). The context-aware prompting strategy is developed to achieve indoor lighting dynamic control with domain knowledge base. An experiment was implemented in an office scenario, which employed to validate the feasibility and effectiveness of the proposed ideas. This research can provide new ideas to improve human-centric lighting system.
Facades, as a building component, directly impact indoor comfort conditions. Different facades systems have been developed not only to cope with thermal and visual comfort aspects, but also for energy efficiency, use of daylight, and natural ventilation. Designers consider Double Skin Facade (DSF) systems in educational buildings to improve the abovementioned performance aspects. Recent works deal with a fixed room depth for proposed parametric DSF models, considering fundamental versions of well-known optimisation algorithms. Since the educational buildings require various room depths based on the function of the building, optimum daylight performance may not be achieved with the same cavity gap utilizing only one well-known solver. This study proposes a computational framework to cope with this problem in DSFs for educational buildings. In this context, the study suggests a parametric educational space with a DSF system and optimised seven design parameters, including twelve room depth scenarios by using three single objective optimisation algorithms. The study suggests optimised design scenarios for spatial Daylight Autonomy (sDA) and Annual Sun light Exposure (ASE) in the region between 35(o)-40(o) N latitudes of the Mediterranean CSA climate type(1). Although previous works have frequently used the genetic algorithm (GA) to solve DSF design problems, results showed that GA is unsuitable for coping with sDA and ASE. The results indicated that a single opening is insufficient to provide optimum sDA and ASE in educational buildings with DSF systems, which room depth of more than 7 m.
This study investigates the impact of illumination levels on classification performance in microscopic cell images and proposes a novel approach for the deep learning-based diagnosis of white blood cells. The proposed method integrates statistical texture features derived from grayscale images based on GLCM1 and LBP2 with the Convolutional Block Attention Module (CBAM) in a hybrid architecture built upon the VGG16 model. In this architecture, both visual (RGB) and structural (texture) information are processed simultaneously, aiming to obtain deeper and more meaningful representations for classification. Within this scope, the effect of varying illumination levels on microscopic images has been evaluated in detail for the first time, and the model's performance was tested under multiple lighting conditions. As part of the study, nine different illumination conditions were created by adjusting light levels from-80 to +80, and the model's classification performance under each condition was comprehensively evaluated. According to the findings, only 11
Ground surface reflectance recovered from the satellite data are the basis for satellite monitoring of the state of the ground surface. To obtain high-quality information about the reflectivity properties of the ground surface, it is necessary to perform atmospheric correction of the images. The formation of the received radiance is influenced by a significant number of factors, which include the following: - Radiation scattering, - Radiation absorption by atmospheric gases, - Adjacency effect, - Multiple reflection of radiation, - Radiation polarization, - Non-Lambertian surface reflection, - Relief, - Cloudiness, - Interaction of radiation with the vegetation layer. At present, there are no algorithms that would take into account all the main factors affecting radiation transfer. Previous approaches widely use the approximation of a uniform surface (independent pixels). In more complex algorithms, adjacency effect is taken into account exactly, and additional illumination by multiple reflected radiation is taken into account in the approximation of a uniform surface. In algorithms that take relief into account, scattering is considered to have no effect on the result, or the approximation of a uniform surface is used. In the proposed approach, unlike alternative ones, the influence of the non-uniformity of the ground surface reflectance and the altitude of the observed areas on the formation of adjacency effect and additional illumination of the ground surface is taken into account. The presented test calculation shows that the proposed algorithm for the considered situation has an average difference in results triangle r(surf) =0.014, a root-mean-square difference in results RMSE = 0.017 and a correlation coefficient r = 0.97 compared to the results of the NASA MOD09 algorithm.
Indoor sports halls are areas, in which sports competitions are frequently held, and factors affecting physical risk, such as lighting, temperature, and sound, must be controlled in order to conduct these competitions efficiently. Of these, lighting is the most important, as it directly affects the vision of athletes, referees, and spectators. Ensuring ideal lighting in indoor sports halls is essential in order to prevent performance losses due to visual impairments in athletes and referees, and to enhance the spectators' viewing pleasure. The primary conditions for achieving this are maintaining the average luminance at an optimal level and eliminating harmonics in the luminance distribution, thereby ensuring uniformity of luminance on the floor. Hence, the luminance values in the environment should be periodically checked, and necessary maintenance should be performed as required. Measuring luminance values at various points in the environment is essential for critical maintenance work and improvements, but this process is currently labourintensive and time-consuming, making it impossible to mathematically calculate the luminance distribution in an environment following physical wear and tear. Given these challenges, the need for a new method is evident. This study proposes a new prediction method for inspecting the uniformity of luminance in indoor sports halls. Using this method, the average luminance values in indoor sports halls can easily be predicted and non-uniform points in the luminance distribution identified, allowing timely intervention in the system.
Light is a key factor that enables people to see and evaluate objects, shapes, and colours. There are a significant number of industrial accidents worldwide due to inadequate lighting. Light contributes to the creation of normal working conditions. At the same time, the proper organization of industrial lighting is an integral part of human working conditions. Proper workplace lighting design protects human vision and the nervous system and ensures safety in the workplace. It should be noted that labour productivity and product quality directly depend on adequate lighting. The use of daylight in industrial buildings is a key strategy for reducing energy consumption, improving energy efficiency, and improving the quality of the environment. This can be achieved through the proper design of various translucent structures, which allow for control over the amount of daylight entering the premises. When operating industrial buildings, the cost of electricity for electrical lighting is one of the most important issues. At the same time, electricity consumption can be significantly reduced through the use of daylight, which in turn makes it possible to increase labour productivity. On the other hand, the large amount of glazing in industrial buildings and the lack of properly designed daylighting increase energy consumption costs associated with the need to heat and cool spaces at different times of the year. Thus, the proper design of lighting systems in industrial buildings is a key aspect that, in turn, makes it possible to reduce electricity consumption.
The article is devoted to the description of a natural experiment to assess the comfort of the internal microclimate in the premises of a residential building using the method of subjective expert assessment in the conditions of the hot and sunny climate of Syria. The current popularity of the subjective assessment method is noted, since it is a real test of the conclusions that are given in the process of objective experimental studies. The article describes the preparatory stage of the experiment, the process of selecting observations, forming a questionnaire, the results obtained and the conclusions made. The assessment scale used by observers is also noted. The history of the development and improvement of the method of subjective expert assessment is analysed and variant methods of its application are described. Based on the results of the experiment, a number of conclusions are made, which are used by the authors along with the conclusions obtained during the objective stage of the experiment on a real object. The main conclusion is made about the relevance of the subjective expert method of research, as a result of which various aspects are revealed that were not taken into account in the course of the objective experiment conducted earlier. The subjective stage covered a larger range of issues related to the comfort of the internal microclimate. In particular, in addition to the quality of the light environment, the issues of insolation and sun protection and the psychological connection of observers with the external environment through window openings were also considered. Further, in the following studies it is planned to identify, by means of a comparative analysis, the correspondence of the conclusions obtained as a result of two full-scale experiments (objective and subjective) to each other and to make new, final conclusions. So far, it can only be stated that the subjective expert assessment reveals many new nuances that are not taken into account in the full-scale objective experiment, which should be specified in new studies continuing the ones considered.
When reconstructing a building, its dimensions are often increased in width and height. As a result, in conditions of dense development, regulatory requirements for daylighting of residential premises in adjacent buildings are violated. This circumstance has a detrimental effect on human health. In addition, the cost of electricity for electrical lighting is increasing. When carrying out reconstruction, it is important that changes in the dimensions of the reconstructed building do not lead to a decrease in the standard level of daylighting. An analysis of existing domestic and foreign regulatory documents, as well as methods for ensuring the standardized level of daylighting during the reconstruction of buildings, was conducted. A promising method of using reflective structures and materials during reconstruction in densely populated areas was selected for further research.
This research focuses on the design features of daylight in buildings using CLT (cross-laminated timber) panels. As a rule, when factory-finished, the inner surface of the CLT panel has a natural wood colour. The colour palette of structural wood is rich in various textures and shades, which greatly complicates the process of determining the interior surface reflectance of these materials. A minimum of three colours can be present on one square meter of the CLT panel surface. This means that the reflection coefficient of the CLT panel surface will be determined as reduced to a single indicator. To improve the accuracy of calculations of daylight, the authors suggest clarifying the values of interior surface reflectance for wood materials and fixing them in regulatory documents. This requires additional research using a set of numerical and laboratory studies to refine the calculation methodology for this indicator. It is assumed that the developed recommendations for calculating the daylight of rooms in buildings using CLT panels will contribute to improving the energy efficiency of buildings, thanks to the rational selection of lighting devices and the calculation of the required illumination level. The implementation of the recommendations will create the prerequisites for the further development of wooden house construction in Russia and the world.
The article discusses the issues of solar radiation exposure of vertical enclosing structures. The external enclosing structures receive heat from exposure to solar radiation, which leads to heating of the wall, an increase in temperature in the entire structure and a change in the microclimatic parameters of the room. Modelling the processes of temperature change in the thickness of the enclosing wall structure will allow taking into account the processes of heat transfer when choosing building materials for the construction of buildings. To study the effect of the amount of solar radiation received by vertical surfaces of buildings on the temperature change inside the enclosing structure, modelling of the thermophysical parameters of the wall using the COMSOL software package was used. Single-layer, double-layer, and three-layer walls of buildings with facade materials with different absorption coefficients of solar radiation were chosen as the objects of research. The simulation was conducted for the summer solstice. The values of solar radiation received by vertical structures oriented to the south on the day of the summer solstice are considered. The total amount of solar radiation received by the vertical structures of the southern facade, located at 48 degrees C and 58 degrees C, on the day of the summer solstice, is almost the same. To estimate the heating of vertical enclosing structures by solar radiation, the formula of A.M. Shklover was used. The modelling was carried out for three types of enclosing structures (one-, two-and three-layer). When modelling heat transfer processes, the colour of facade finishing materials was taken into account, a comparative analysis of heat transfer by enclosing structures with the same absorption coefficients of solar radiation was carried out, as well as an analysis of walls, which facades had different absorption coefficients of solar radiation. The influence of the amount of solar radiation received by the vertical surfaces of buildings on the temperature change in the thickness of the enclosing wall structure is shown. The results of the study showed that the solar radiation absorption coefficient of the facade material has a greater effect on the temperature change inside the enclosing structures with the lowest thermal inertia. It is established that when the coefficient of absorption of solar radiation by the facade material is 0.3, heat transfer in single-layer and double-layer fencing occurs with almost the same intensity, with an increase in the coefficient of absorption of solar radiation by the facade material to 0.6, the intensity of heat transfer in the two-layer fencing increases.
Part 1 provides general information on some physical properties of water, ice and snow, necessary for understanding the considered non-stationary processes of freezing and thawing of enclosing structures of wet foundation soils. Part 2 provides a physical and mathematical formulation of the problem of freezing of wet soil, the Lame and Clapeyron solution, the Stefan solution, a physical and mathematical formulation of the problem of freezing of a strip foundation. The following are considered: a description of the freezing process of a single-layer enclosing structure, taking into account the phase transformations of moisture in the material of the structure according to V.N. Bogoslovsky and the freezing process of an unlimited plate, taking into account the phase transformations of moisture in the material of the structure according to A.V. Lykov, mathematical model of the non-stationary process of heat transfer in wet layered media. Based on the method of small-time intervals, solutions of boundary value problems for the frozen and thawed zone in the region of large and small Fourier numbers are given. The prospects for using the proposed mathematical models to describe freezing processes of enclosing structures and foundation soils are outlined. Part 3 presents a physical picture of the process of freezing of a wet (thawing of a frozen) foundation consisting of different soil layers under different boundary conditions on the surface, as well as a mathematical model describing this process. Part 3 is a continuation of Part 2.
The work is devoted to the development of an approach to a comprehensive assessment of the general natural lighting of rooms, focused not only on meeting regulatory requirements, but also on the subjective perception of the light environment by the user. It is proposed to consider the room as an active element in the formation of a light pattern, while taking into account not only the characteristics included in the calculation of the coefficient of daylight illumination (D), but also additional parameters that are traditionally not included in this indicator. The purpose of the study is to formulate the principles of a method for assessing total natural lighting based on a combination of known lighting quantities and qualia-metrical analysis. The paper uses methods for calculating and measuring daylight factor D, conducted in field studies in two classrooms with different types of daylighting using verified luxmeters. Additionally, a simulation of the light environment was performed in the Relux software environment. The method of qualia-metric analysis is proposed as a promising tool for comprehensive assessment. D values were determined for the studied rooms, a tree of properties was constructed within the framework of qualia-metric analysis, and the main groups of criteria influencing the perception of general daylighting were identified. The conducted research has shown that the application of the qualia-metric approach in combination with the D indicator provides a more comprehensive and sensitive assessment of the quality of daylighting. The proposed method can be used at the conceptual design stage to select optimal spatial planning solutions and predict user satisfaction with the light environment.
