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An efficient urban development needs to reduce the carbon footprint by providing an innovative solution for street lighting deployment. Hence, a geographic information system is proposed to highlight the illumination levels and energy classes of streets, enabling energy-efficient street lighting. The proposed study investigates the intended area of the satellite image, for initial preprocessing. To identify the closest point the proposed methodology uses the entire training dataset. Subsequently, a classification report comprising the illuminated area and the value of power for each class is obtained. The proposed work is assessed using various performance measures, such as user accuracy, producer accuracy, overall accuracy, and the kappa coefficient. The superiority of the proposed method over traditional techniques shows an improvement in overall accuracy by 17.38–25.38% and the kappa coefficient by increasing its value from 0.2469 to 0.42, respectively. [ABSTRACT FROM AUTHOR] more...

Objectives: This paper estimates the effect of changes in street lighting at night on levels of crime at street-level. Analyses investigate spatial and temporal displacement of crime into adjacent streets. Methods: Offense data (burglaries, robberies, theft of and theft from vehicles, and violent crime) were obtained from Thames Valley Police, UK. Street lighting data (switching lights off at midnight, dimming, and white light) were obtained from local authorities. Monthly counts of crime at street-level were analyzed using a conditional fixed-effects Poisson regression model, adjusting for seasonal and temporal variation. Two sets of models analyzed: (1) changes in night-time crimes adjusting for changes in day-time crimes and (2) changes in crimes at all times of the day. Results: Switching lights off at midnight was strongly associated with a reduction in night-time theft from vehicles relative to daytime (rate ratio RR 0.56; 0.41–0.78). Adjusted for changes in daytime, night-time theft from vehicles increased (RR 1.55; 1.14–2.11) in adjacent roads where street lighting remained unchanged. Conclusion: Theft from vehicle offenses reduced in streets where street lighting was switched off at midnight but may have been displaced to better-lit adjacent streets. Relative to daytime, night-time theft from vehicle offenses reduced in streets with dimming while theft from vehicles at all times of the day increased, thus suggesting temporal displacement. These findings suggest that the absence of street lighting may prevent theft from vehicles, but there is a danger of offenses being temporally or spatially displaced. [ABSTRACT FROM AUTHOR] more...

Consumption of power is essential for the sustainability of future generations. The constant developing world makes everyone run beyond the capabilities and to meet the needs of the growing world. Conservation of electricity is the least concern of the today’s man. Concern to this problem, automated street light system can play a part in the electricity guard. The street light is combined with Light Dependent Resistor (LDR) to make it automatically identifying the range of visible light and perform decision making whether to turn on or turn off the light. more...

Trees in urban areas provide important ecosystem services and are an essential element of urban green space. The constant increase in artificial light from anthropogenic activities around the world creates photopollution that affects the phenology and physiology of plants. Here we conducted a field study to investigate the anthropogenic impacts on six urban trees (Saraca asoca, Terminalia catappa, Bauhinia variegata, Holoptelea integrifolia, Ficus benjamina and Thevetia peruviana) using chlorophyll fluorescence analysis. OJIP curve, maximum quantum yield of primary photochemistry (ΦPo), quantum yield of electron transport (ΦEo), probability that an absorbed photon will be dissipated (ΦDo), photosynthetic performance index (PIcsm) and reaction center photochemistry were assessed. According to the results, various parameters of chlorophyll fluorescence showed significant and important effects on different tree species. T. peruviana and F. benjamina were found to be tolerant to street lighting, while on the other hand, S. asoca, T. catappa, B. variegata and H. integrifolia were found to be sensitive to artificial light induced by street lamps. This study clearly indicates that chlorophyll fluorescence analysis is a potent method for screening the tolerance of tree species to photopollution induced by artificial lights. more...

Trees in urban areas provide important ecosystem services and are an essential element of urban green space. The constant increase in artificial light from anthropogenic activities around the world creates photopollution that affects the phenology and physiology of plants. Here we conducted a field study to investigate the anthropogenic impacts on six urban trees (Saraca asoca, Terminalia catappa, Bauhinia variegata, Holoptelea integrifolia, Ficus benjamina and Thevetia peruviana) using chlorophyll fluorescence analysis. OJIP curve, maximum quantum yield of primary photochemistry (ΦPo), quantum yield of electron transport (ΦEo), probability that an absorbed photon will be dissipated (ΦDo), photosynthetic performance index (PIcsm) and reaction center photochemistry were assessed. According to the results, various parameters of chlorophyll fluorescence showed significant and important effects on different tree species. T. peruviana and F. benjamina were found to be tolerant to street lighting, while on the other hand, S. asoca, T. catappa, B. variegata and H. integrifolia were found to be sensitive to artificial light induced by street lamps. This study clearly indicates that chlorophyll fluorescence analysis is a potent method for screening the tolerance of tree species to photopollution induced by artificial lights. [ABSTRACT FROM AUTHOR] more...

Objective: Pedestrian fatalities in the United States increased 51% from 2009 to 2019. During that time, pedestrian fatalities occurring at night increased by 63.7%, compared to a 17.6% increase for pedestrian fatalities occurring during daylight conditions. Have there also been increases in serious, minor, and possible pedestrian injuries (i.e., have all pedestrian collisions been occurring more frequently)? Have pedestrian collisions been getting more severe (i.e., are there now higher proportions of more severe injuries)? Have trends differed between night and day? What role does street lighting play in the nighttime trends?Methods: We analyzed pedestrian fatalities, serious injuries, minor injuries, and possible injuries that occurred in California, North Carolina, and Texas from 2010 to 2019 using linear regressions to explore the strength and statistical significance of trends. We then parsed these trends by lighting condition, exploring outcomes during the day and night and with and without street lighting.Results: Findings suggest that increases in daytime minor (7.9%) and possible (7.5%) injuries closely mirrored increases in population (9.8%). Increases in daytime fatal/serious injuries were significantly higher (43.1% and 35.1%, respectively), suggesting worsening severities during the day. Increases in nighttime minor/possible injuries (31.9% and 27.6%, respectively) were significantly larger than those during the day, suggesting that pedestrian collisions are occurring more frequently at night. Substantial increases in nighttime fatal/serious injuries (78.0% and 74.7%, respectively) likely reflect a combination of worsening severity (seen throughout the day) and increasing frequency (seen particularly at night). A pedestrian injured in the dark was found to be 5.0 times more likely to be killed than a pedestrian injured during the day. While a lack of street lighting does not seem to be the cause of the disproportionate increase in pedestrian injuries at night, pedestrians struck without a street light were 2.4 times more likely to be killed than those struck in the presence of a street light.Conclusions: As we find ourselves in the midst of a pedestrian safety crisis, understanding that severities have increased throughout the entire day and frequencies have increased particularly at night helps illuminate a path forward. [ABSTRACT FROM AUTHOR] more...

In this paper, the six-step strategy for bionic inspiration in industrial design and engineering is improved with involvement of an additional tool - functional decomposition. The improved strategy is explained through a design case study. The case study uses a "bottom-up" approach for identifying the key functionalities of the dandelion flower which is recognized as a unique natural phenomenon. Those functionalities are then redefined in a technical manner and used for designing a solar street light with the goal to achieve unique aesthetics and segmentation (modularity). The presented tools for systematization of gathered bionic information can help make the bionic product development processes more efficient. [ABSTRACT FROM AUTHOR] more...

To realize energy conservation and environmental protection, solar street lights have been widely used in urban areas in China. To reasonably and effectively utilize solar street lights, the original street lights must be located, and the solar street light potential must be assessed. The Jilin1-03B (JL1-3B) satellite provides next-generation nighttime light data with a high spatial resolution and in three spectral bands. Consequently, the street lights can be extracted from the nighttime light data. We used the road network dataset from the open street map with a specific buffer to extract the road area as a constraint region. Next, the grayscale brightness of JL1-3B images was obtained by integrating all the three bands to locate the street light by using a local maximum algorithm. Then, the values of the original three bands were utilized to classify the types of street lights as high-pressure sodium (HPS) lamps or light-emitting diode lamps. Finally, we simulated the replacement of all the HPS lamps with solar street lights and assessed the corresponding solar energy potential by using the digital surface model data and hourly cloud cover data through the SHORTWAVE-C model. The accuracy of location of the street lights was approximately 90%. Replacing an HPS lamp by one solar street light for 20 years can save 1.85 × 104 kWh of electrical energy, 7.41 t of standard coal, 5.03 t of C emissions, 18.47 t of CO2 emissions, 0.55 t of SO2 emissions, and 0.28 t of NOX emissions. more...

Recently, the installation of street light systems in remote communities has experienced significant improvement. This improvement has a direct relationship with the innovations in off-grid standalone energy sources. However, there exists sparse information on standalone PV-powered street light system maintenance. This is because existing models consider mainly the technical aspects of this system maintenance. The current study, therefore, presents a robust perspective on this system maintenance. It presents a framework that evaluates maintenance strategies for off-grid PV-powered street light systems; the framework considered STEEP (social, technical, economic, environmental and policy) requirements during maintenance activities. These requirements were used to design a SWOT (strength, weakness, opportunity and threats) framework that analyzes maintenance strategies for this system using a standard TOPS IS (Technique for Order of Preference by Similarity to Ideal Solution) and a fuzzy TOPSIS (F-TOPSIS) methods. Data from a community in Nigeria were used to test the proposed STEEP-cum-SWOT framework performance. It was observed that risk-based and condition-based maintenance strategies are the least and most suitable strategies for a standalone off-grid PV-powered street light system in the community. [ABSTRACT FROM AUTHOR] more...

Despite the acclaimed long-term benefits of solar PV systems, most stand-alone solar projects in Nigeria seem to fail within a short duration. In this work, an analysis is carried out to examine the factors that lead to such poor performance of solar projects in Nigeria. A case study of standalone solar street lights (SASSL) in Nsukka geographical region in Nigeria was explored. The field work was carried out from Dec 2016 - January 2018. Data from field indicate that in most cases, premature battery failure due to undercharging was responsible for the collapse of these stand-alone solar systems. Given that the PV module is the sole charge generator in SASSL, the energy yield of the PV modules used in the SASSLs were further investigated. Controlled experiments were carried out to determine the impact of specific environmental and installations conditions on the yield of the PV modules. The results of the experiments led to the development of a model. The weather and installation specific data were then inserted into the model and were used to determine the likely reasons for the premature failure of SASSLs. The results indicated that the within the period under review, the PV modules were capable of providing adequate energy to the battery for only 25% of the time. For another 25% of the time the energy provided were marginal while for 50% of the time the energy provided were grossly inadequate. [ABSTRACT FROM AUTHOR] more...

This paper describes the use of a new obtrusive light module of the Illumina v2 model to estimate the light that may enter bedroom windows. We used the following as input to the model: (1) the sources’ flux and spectrum derived from the color images taken by astronauts from the International Space Station (ISS), (2) an association between source spectrum and angular emission, and (3) a per zone inventory of obstacles properties and lamp height. The model calculates the spectral irradiance incident to buildings’ windows taking into account the orientation of the street. By using the color information from an ISS image, we can classify pixels as a function of their spectra. With the same image, it is also possible to determine the upward photopic radiance for each pixel. Both serve as inputs to the model to calculate the spectral irradiance on any window. By having the spectral irradiance, it is possible to determine the Melatonin Suppression Index and the photopic irradiance on the window. Such information can later be used to perform epidemiological studies. The new methodology is applied to the city of Montréal in Canada for a set of houses’ locations. The computations are made for 2013 (pre-LED era). more...

Among the pressures introduced by urbanization, artificial light at night (ALAN) can be problematic, particularly for nocturnal species. Populations of European hamsters (Cricetus cricetus) have dramatically decreased in France since 1972 because of habitat loss due to urbanisation and changes in agricultural methods. The conservation project Life Alister aims to increase the abundance of this species in suburban areas via hamster release. However, the success of this population-restoration project may be compromised due to the possible effects of ALAN on the daily and seasonal cycles and behaviour of this nocturnal species. To understand how hamsters may respond to relocation, we experimentally studied the impact of ALAN on hamster foraging, a decisive behaviour for survival in natural habitats. This study assessed the behavioural responses of 18 animals when choosing between two food sources of different palatability in two different lighting conditions: artificial light (4 or 40 lux) or darkness. Our results show that hamsters avoided lighting that mimics suburban streetlights, particularly when grooming. Moreover, this study reveals that hamsters do not avoid street-lit areas when highly palatable food is present, suggesting they would be more susceptible to predation under these circumstances. Our results suggest that the adverse effects of ALAN on the behaviour of hamsters released on the outskirts of developed suburban areas could be limited by restricting the number of street lights, moderating the intensity of street lighting, or switching lights off during the hours hamsters are most active. We further recommend that wildlife managers avoid planting plants that are highly palatable to hamsters close to lighting in suburban areas to limit the risk of predation for this species. [ABSTRACT FROM AUTHOR] more...

High-power light emitting diodes (HPLEDs) have been applied extensively in lighting industry. This study proposes a procedure for analyzing the reliability of a typical HPLED assembly of street light under thermal environments. The junction temperature of a single package component under a canonical thermal environment is found through finite element analysis. The lifetime of the package component is then estimated with the help of the life prediction rule after the junction temperature is obtained. To reflect real situation, the uncertainty of thermal environments is further considered by assuming that the mixed convection heat transfer coefficient is a random variable. To simplify the analysis of the assembly, the circuit configuration of the assembly is addressed and discussed from the viewpoint of a system and its components. It is found that uncertainty of thermal environments does make the lifetime distributions more dispersed. With regard to the reliability, the assembly degrades faster than that of its package components; however, the reliability distribution of assembly is more concentrated than that of its package components. The results of this study can provide information for a street-light engineer to plan a maintenance strategy in advance. [ABSTRACT FROM AUTHOR] more...