A Basic Study on the Performance Evaluation of a Movable Light Shelf with a Rolling Reflector That Can Change Reflectivity to Improve the Visual Environment.

In recent years, the need for comfortable visual environments in indoor spaces has increased energy use in buildings. There have been diverse studies on using a light shelf to solve this problem. It is an effective system that allows external natural light deep into indoor spaces through reflection. However, prior studies have used light shelves with a fixed reflectivity, and there are few studies on improving the visual environment through light shelf control. Therefore, this study proposes a movable light shelf with a rolling reflector that can change the reflectivity. To achieve these objectives, we conducted a performance evaluation of the system's ability to save energy and improve the visual environment. This study built a real scale testbed and conducted a performance evaluation by deriving values for lighting energy consumption, uniformity, and luminance contrast depending on the light shelf variables. We conclude that (1) the light shelf system achieved an energy savings of 13.6% and 5.7%, respectively, compared to a fixed type light shelf, whose reflectivity cannot be changed, and a traditional movable light shelf; (2) in terms of improving the visual environment, results suggest that the visual environment could be improved using a light shelf by deriving light shelf variables that disturb indoor uniformity; and (3) the results verified glare generation conditions by deriving luminance contrast caused by the variables of light shelf angle and its reflectivity.

LEDs for photons, physiology and food.

Lighting based on light-emitting diodes (LEDs) not only is more energy efficient than traditional lighting, but also enables improved performance and control. The colour, intensity and distribution of light can now be controlled with unprecedented precision, enabling light to be used both as a signal for specific physiological responses in humans and plants, and as an efficient fuel for fresh food production. Here we show how a broad and improved understanding of the physiological responses to light will facilitate greater energy savings and provide health and productivity benefits that have not previously been associated with lighting.

Estimation of consumption potentiality using VIIRS night-time light data.

As an informative proxy measure for a range of urbanisation and socioeconomic variables, satellite-derived night-time light data have been widely used to investigate the diverse anthropogenic activities and reveal social economy development disparities from the regional to the national scale. The new-generation night-time light data have been proven to potentially improve our understanding in the development and inequality of urban social economy due to its high spatial resolution, strong timeliness and minimal background noise. These night-time light data are derived from the visible infrared imaging radiometer suite (VIIRS) instrument with day/night band located on the Suomi National Polar-orbiting Partnership (NPP) satellite. This study proposed a hybrid model to estimate urban consumption potentiality based on the comprehensive information of human activities obtained from the VIIRS night-time light data. Our method established a flexible geographically weighted regression-based estimation model based on the residential consumption data and DN values of the VIIRS data to predict the possible consumption potentiality of other urban areas in dynamic time. The experiment conducted in Guiyang, a provincial capital in China, affirms that our model is proven to have higher accuracy compared with traditional regression models and can potentially provide guidance for improved business management and increased profit.

Nighttime lights as a proxy for human development at the local level.

Nighttime lights, calculated from weather satellite recordings, are increasingly used by social scientists as a proxy for economic activity or economic development in subnational regions of developing countries where disaggregated data from statistical offices are not available. However, so far, our understanding of what nighttime lights capture in these countries is limited. We use geo-referenced Demographic and Health Surveys (DHS) from 29 African countries to construct indicators of household wealth, education and health for DHS cluster locations as well as for grid cells of roughly 50 × 50 km. We show that nighttime lights are positively associated with these location-specific indicators of human development, and that the variation in nighttime lights can explain a substantial share in the variation in these indicators. We conclude that nighttime lights are a good proxy for human development at the local level.

Using machine-learning to optimize phase contrast in a low-cost cellphone microscope.

Cellphones equipped with high-quality cameras and powerful CPUs as well as GPUs are widespread. This opens new prospects to use such existing computational and imaging resources to perform medical diagnosis in developing countries at a very low cost. Many relevant samples, like biological cells or waterborn parasites, are almost fully transparent. As they do not exhibit absorption, but alter the light's phase only, they are almost invisible in brightfield microscopy. Expensive equipment and procedures for microscopic contrasting or sample staining often are not available. Dedicated illumination approaches, tailored to the sample under investigation help to boost the contrast. This is achieved by a programmable illumination source, which also allows to measure the phase gradient using the differential phase contrast (DPC) [1, 2] or even the quantitative phase using the derived qDPC approach [3]. By applying machine-learning techniques, such as a convolutional neural network (CNN), it is possible to learn a relationship between samples to be examined and its optimal light source shapes, in order to increase e.g. phase contrast, from a given dataset to enable real-time applications. For the experimental setup, we developed a 3D-printed smartphone microscope for less than 100 $ using off-the-shelf components only such as a low-cost video projector. The fully automated system assures true Koehler illumination with an LCD as the condenser aperture and a reversed smartphone lens as the microscope objective. We show that the effect of a varied light source shape, using the pre-trained CNN, does not only improve the phase contrast, but also the impression of an improvement in optical resolution without adding any special optics, as demonstrated by measurements.

A practical review of energy saving technology for ageing populations.

Fuel poverty is a critical issue for a globally ageing population. Longer heating/cooling requirements combine with declining incomes to create a problem in need of urgent attention. One solution is to deploy technology to help elderly users feel informed about their energy use, and empowered to take steps to make it more cost effective and efficient. This study subjects a broad cross section of energy monitoring and home automation products to a formal ergonomic analysis. A high level task analysis was used to guide a product walk through, and a toolkit approach was used thereafter to drive out further insights. The findings reveal a number of serious usability issues which prevent these products from successfully accessing an important target demographic and associated energy saving and fuel poverty outcomes. Design principles and examples are distilled from the research to enable practitioners to translate the underlying research into high quality design-engineering solutions.

Utility of a simple lighting device to improve chest compressions learning. / Utilidad de un dispositivo luminoso simple para mejorar el aprendizaje del masaje cardiaco.

INTRODUCTION: The recommendations on cardiopulmonary resuscitation (CPR) emphasize the quality of the manoeuvres, especially chest compressions (CC). Audiovisual feedback devices could improve the quality of the CC during CPR. The aim of this study was to evaluate the usefulness of a simple lighting device as a visual aid during CPR on a mannequin. MATERIAL AND METHODS: Twenty-two paediatricians who attended an accredited paediatric CPR course performed, in random order, 2min of CPR on a mannequin without and with the help of a simple lighting device, which flashes at a frequency of 100 cycles per minute. The following CC variables were analyzed using a validated compression quality meter (CPRmeter®): depth, decompression, rate, CPR time and percentage of compressions. RESULTS: With the lighting device, participants increased average quality (60.23±54.50 vs. 79.24±9.80%; P=.005), percentage in target depth (48.86±42.67 vs. 72.95±20.25%; P=.036) and rate (35.82±37.54 vs. 67.09±31.95%; P=.024). CONCLUSIONS: A simple light device that flashes at the recommended frequency improves the quality of CC performed by paediatric residents on a mannequin. The usefulness of this CPR aid system should be assessed in real patients.

Evaluation of overhead guide sign sheeting materials to increase visibility and safety for drivers.

Overhead guide sign visibility must increase to improve driver safety on roadways. Two methods increase overhead guide sign visibility: sign illumination and use of retroreflective sheeting materials. This paper compares three types of retroreflective sheeting: Engineering Grade (type I), Diamond Grade (type XI), and High Intensity (type IV). A field experiment was conducted at night using licensed drivers to determine the optimum retroreflective sheeting material that increases sign visibility and legibility. Results showed that, of the three types of retroreflective sheeting, Diamond Grade (type XI) sheeting requires minimum illuminance to be visible, followed by High Intensity (type IV) sheeting. Cost analysis, including labor, maintenance, and material cost components of the three retroreflective sheeting materials, showed that High Intensity (type IV) could increase sign visibility and legibility at night for Departments of Transportation with limited budgets, consequently increasing driver safety on roadways.

A Simple low-cost device enables four epi-illumination techniques on standard light microscopes.

Back-scattering darkfield (BSDF), epi-fluorescence (EF), interference reflection contrast (IRC), and darkfield surface reflection (DFSR) are advanced but expensive light microscopy techniques with limited availability. Here we show a simple optical design that combines these four techniques in a simple low-cost miniature epi-illuminator, which inserts into the differential interference-contrast (DIC) slider bay of a commercial microscope, without further additions required. We demonstrate with this device: 1) BSDF-based detection of Malarial parasites inside unstained human erythrocytes; 2) EF imaging with and without dichroic components, including detection of DAPI-stained Leishmania parasite without using excitation or emission filters; 3) RIC of black lipid membranes and other thin films, and 4) DFSR of patterned opaque and transparent surfaces. We believe that our design can expand the functionality of commercial bright field microscopes, provide easy field detection of parasites and be of interest to many users of light microscopy.

The effect of reduced street lighting on road casualties and crime in England and Wales: controlled interrupted time series analysis.

BACKGROUND: Many local authorities in England and Wales have reduced street lighting at night to save money and reduce carbon emissions. There is no evidence to date on whether these reductions impact on public health. We quantified the effect of 4 street lighting adaptation strategies (switch off, part-night lighting, dimming and white light) on casualties and crime in England and Wales. METHODS: Observational study based on analysis of geographically coded police data on road traffic collisions and crime in 62 local authorities. Conditional Poisson models were used to analyse longitudinal changes in the counts of night-time collisions occurring on affected roads during 2000-2013, and crime within census Middle Super Output Areas during 2010-2013. Effect estimates were adjusted for regional temporal trends in casualties and crime. RESULTS: There was no evidence that any street lighting adaptation strategy was associated with a change in collisions at night. There was significant statistical heterogeneity in the effects on crime estimated at police force level. Overall, there was no evidence for an association between the aggregate count of crime and switch off (RR 0.11; 95% CI 0.01 to 2.75) or part-night lighting (RR 0.96; 95% CI 0.86 to 1.06). There was weak evidence for a reduction in the aggregate count of crime and dimming (RR 0.84; 95% CI 0.70 to 1.02) and white light (RR 0.89; 95% CI 0.77 to 1.03). CONCLUSIONS: This study found little evidence of harmful effects of switch off, part-night lighting, dimming, or changes to white light/LEDs on road collisions or crime in England and Wales.

Reduced street lighting at night and health: A rapid appraisal of public views in England and Wales.

Financial and carbon reduction incentives have prompted many local authorities to reduce street lighting at night. Debate on the public health implications has centred on road accidents, fear of crime and putative health gains from reduced exposure to artificial light. However, little is known about public views of the relationship between reduced street lighting and health. We undertook a rapid appraisal in eight areas of England and Wales using ethnographic data, a household survey and documentary sources. Public concern focused on road safety, fear of crime, mobility and seeing the night sky but, for the majority in areas with interventions, reductions went unnoticed. However, more private concerns tapped into deep-seated anxieties about darkness, modernity 'going backwards', and local governance. Pathways linking lighting reductions and health are mediated by place, expectations of how localities should be lit, and trust in local authorities to act in the best interests of local communities.

Pilot project in rural western Madhya Pradesh, India, to assess the feasibility of using LED and solar-powered lanterns to remove kerosene lamps and related hazards from homes.

BACKGROUND: Globally, 300,000 deaths are estimated to occur annually and the incidence is far greater as a large majority of burns are small and go unreported. Ninety-five percent of the global burden of burns is found in low- and middle-income countries; however, there is relatively little in the literature regarding effective primary prevention in these areas. Flame is the most common cause of burn in Madhya Pradesh, the central state of India. The most common demographic among the burn unit inpatient of Choithram hospital Indore, is young women from 21 to 40 years of age, whose burns are primarily caused by kerosene lamps. A non electrical source of illumination is essential for every household in rural areas due to the infrequent and poor power supply. At the baseline, 23 kerosene lamp burns were reported by villagers in the past 5 years among the study population of this pilot project. METHOD: A pilot project to investigate the strategies for reducing the incidence of domestic burns in rural villages around the city of Indore was performed, by replacing kerosene lamps with safer and more sustainable alternatives, including solar-powered and light-emitting diode (LED) lamps. A total of 1042 households were randomly chosen from 18 villages within the Malwa region of Madhya Pradesh (population of 28,825) to receive the alternative light source (670 LED and 372 solar lamps). We investigated the efficacy of this strategy of reducing the incidence of burns, measured the social acceptance by villagers, and quantified the cost implications and availability of LED lamps in rural communities with a high incidence of burns. RESULTS: Replacing kerosene lamps with LED and solar alternatives was deemed socially acceptable by 99.34% of the participants and reduced the cost of lighting for impoverished rural villagers by 85% over 1 year. We successfully demonstrated a significant decrease in the use of kerosene lamps (p<0.01). More evidence is required to investigate the efficacy of this strategy in reducing burns. CONCLUSION: This pilot study highlights the viability of the approach of replacing kerosene lamps as an effective primary prevention strategy for reducing burns in rural areas. However, barriers remain to the wider adoption of these lamps, including accessibility and availability for the populations of rural India.

Significant potential for lower costs.

Switching to LED lighting has, specialist supplier of such technology, Exled maintains, 'proven to be one of the most significant cost-saving activities hospitals can undertake'. Alongside the financial gains, other benefits include higher levels of patient satisfaction with lighting 'quality' and ambience, and improved environmental credentials. Here Exled MD, Michael Renecle, discusses LED lighting in healthcare in some detail, offers useful pointers on specification, examines some of the 'significant savings and environmental improvements' available to those 'making the switch', and considers the positive experiences of a number of NHS Trusts who have done so.

Cost-benefit analysis and emission reduction of energy efficient lighting at the Universiti Tenaga Nasional.

This paper reports the result of an investigation on the potential energy saving of the lighting systems at selected buildings of the Universiti Tenaga Nasional. The scope of this project includes evaluation of the lighting system in the Library, Admin Building, College of Engineering, College of Information Technology, Apartments, and COE Food court of the university. The main objectives of this project are to design the proper retrofit scenario and to calculate the potential electricity saving, the payback period, and the potential environmental benefits. In this survey the policy for retrofitting the old lighting system with the new energy saving LEDs starts with 10% for the first year and continues constantly for 10 years until all the lighting systems have been replaced. The result of the life cycle analysis reveals that after four years, the selected buildings will bring profit for the investment.