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Lighting energy performance determination in office environments through implementation of EN 15193-1 for Turkey Lighting Res. Technol. (IF 2.226) Pub Date : 2021-01-26 FŞ Yilmaz
Office buildings are building typologies where efficient and optimal use of lighting energy is crucial while providing comfortable visual environments. The purpose of this study is to explore the impact of diverse architectural design alternatives on lighting energy requirements and lighting energy saving possibilities through a case study. In this study, a total of 3888 design alternatives are investigated
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Night-time disability glare of constant-light LED traffic monitoring fill light Lighting Res. Technol. (IF 2.226) Pub Date : 2021-01-20 X Cai; L Quan; J Wu; Y He
Fill light, used to helps cameras capture road traffic conditions at night, can lead to serious visual consequences for drivers. Research on disability glare from LED fill light is scarce and therefore this study explored strategies for controlling disability glare of constant-light LED traffic monitoring fill light. The threshold increment was used as an index to evaluate disability glare. The effective
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Feasibility and acute alerting effects of a daylight-supplementing in-vehicle lighting system – Results from two randomised controlled field studies during dawn and dusk Lighting Res. Technol. (IF 2.226) Pub Date : 2021-01-18 M Canazei; S Staggl; W Pohl; S Schüler; D Betz; J Ottersbach; R Popp
The present studies examined the feasibility and acute alerting effects of additional in-vehicle lighting within a passenger car. These factors were examined during morning driving (Study 1) and evening driving (Study 2). In a balanced within-subjects design, 37 participants drove a test car two times in the morning or in the evening. The test vehicle was equipped with either a daylight-supplementing
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Is there a difference in how people from different socio-environmental contexts perceive discomfort due to glare from daylight? Lighting Res. Technol. (IF 2.226) Pub Date : 2021-01-10 C Pierson; B Piderit; T Iwata; M Bodart; J Wienold
Exposure to daylight has much to offer and should be optimised to maximise its potential. In order to harvest its benefits, any visual discomfort from daylight should be anticipated and minimised. Hence, there is the need to predict discomfort from daylight glare. While more than 20 models for predicting discomfort from daylight glare have been developed, none accurately predict it. The inclusion of
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Correspondence: On the state of knowledge concerning the effects of temporal light modulation Lighting Res. Technol. (IF 2.226) Pub Date : 2021-01-07 Jennifer A Veitch; Christophe Martinsons; Steve Coyne; Carsten Dam-Hansen
Temporal light modulation (TLM) is a change in the luminous quantity or spectral distribution of light with respect to time of either a light source or a lighting system. These changes arise because of the device or system design, including drivers and control gear, and because of fluctuations in the electrical supply. In former times, families of lighting products all exhibited the same (or approximately
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Editorial: Spot the difference Lighting Res. Technol. (IF 2.226) Pub Date : 2021-01-07 Teresa Goodman
The eagle-eyed among you (particularly those who enjoy reading the print copy of the journal rather than perusing the content online) may have noticed some significant changes to the extent of Lighting Research and Technology over recent years. Long-term readers will know that until 2012 only four issues were published each year, which increased to six per year in 2013 and then eight per year from
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View preference in urban environments Lighting Res. Technol. (IF 2.226) Pub Date : 2020-12-29 A Batool; P Rutherford; P McGraw; T Ledgeway; S Altomonte
With people spending up to 90% of their time in indoor spaces, windows and the visual connection that they afford to the outside, can play an important role in ensuring physical and psychological well-being. This is particularly relevant in urban settings, a substantial part of our lives, whilst still being significantly understudied. What we know from other environments may not translate to cities
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Circadian tuning with metameric white light: Visual and non-visual aspects Lighting Res. Technol. (IF 2.226) Pub Date : 2020-12-25 T Aderneuer; O Stefani; O Fernández; C Cajochen; R Ferrini
The growing awareness of the biological effects of electric light on humans has stimulated ample research. New research has been devoted to lighting solutions that dynamically change their colour to mimic spectral changes of daylight. However, in some situations, the visual properties of light must be preserved, such as when working under standardised lighting conditions to do colour correction in
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Optical design of LED high mast lamp based on TIR freeform lens for annular lighting Lighting Res. Technol. (IF 2.226) Pub Date : 2020-12-18 D Pan; YC Zhang; XF Xie; MJ Fan; YA Chen; SH Yan; SJ Yang
The traditional square spot of street lamp is not suitable for the lighting requirements of the annular road lighting. In this paper, a lens design method for producing annular spot of high mast lamp is proposed. The method mainly contains three optical surfaces, in which the inner surface collimates the energy of the centre part of the light source, the total internal reflection surface collimates
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Personal lighting conditions of office workers: An exploratory field study Lighting Res. Technol. (IF 2.226) Pub Date : 2020-12-15 J van Duijnhoven; MPJ Aarts; HSM Kort
Light enables us to see and perceive our environment but it also initiates effects beyond vision, such as alertness. Literature describes that at least six factors are relevant for initiating effects beyond vision. The exact relationship between these factors and alertness is not yet fully understood. In the current field study, personal lighting conditions of 62 Dutch office workers (aged 49.7 ± 11
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The effect of distraction, response mode and age on peripheral target detection to inform studies of lighting for driving Lighting Res. Technol. (IF 2.226) Pub Date : 2020-12-10 S Fotios; CJ Robbins; SR Fox; C Cheal; R Rowe
It is expected that the detection of peripheral objects, a key visual task for safe driving, is affected by cognitive distraction, by observer age and by the manner in which action is undertaken following detection. An experiment was conducted to measure these effects, using a fixation cross and peripheral target discs displayed on a screen. The experiment was repeated with young (18–25 years) and
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Experimental investigation and empirical modelling of thermal and drive current effect on optical performance of commercial LEDs Lighting Res. Technol. (IF 2.226) Pub Date : 2020-12-09 AN Padmasali; SG Kini
Light-emitting diode is the most dominant lighting technology, and lumen output performance is dependent on junction temperature and operating drive current. An experimental analysis is performed to study the thermal and drive current effect on lumen output, and an empirical model is developed to determine the optimum operating conditions of temperature and drive current so as to obtain a maximum lumen
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The identification of variables influencing personal lighting conditions of office workers Lighting Res. Technol. (IF 2.226) Pub Date : 2020-12-09 J van Duijnhoven; MPJ Aarts; ER van den Heuvel; HSM Kort
The main reason lighting control is being applied is to reduce energy consumption. However, there are many more reasons for lighting control to be optimised in buildings. Lighting systems can be controlled to enhance or optimise effects beyond vision. Automatic control of electric lighting systems or daylight systems is one way of adjusting someone’s personal lighting conditions. In addition, it is
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Editorial: Colouring the inclusive LR&T environment Lighting Res. Technol. (IF 2.226) Pub Date : 2020-12-04 Geoffrey Cook
My tenure as Chair of the LR&T Editorial Board has coincided with several changes. The number and size of the issues within each LR&T volume has increased and more importantly the quality of the content, as assessed by the Impact Factor, has also increased to well above the critical value of 2. This is due to the authors of papers, but also the work of the LR&T Board, the previous Editor in Chief,
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Editorial: Academically trained lighting designer Lighting Res. Technol. (IF 2.226) Pub Date : 2020-11-17 Myriam Aries
Like a dark cloud is the COVID-19 pandemic dominating the year 2020, but its silver lining may be the renewed awareness regarding
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Corrigendum to Road lighting research for drivers and pedestrians: The basis of luminance and illuminance recommendations Lighting Res. Technol. (IF 2.226) Pub Date : 2020-11-17 Steve Fotios; Ron Gibbons
Fotios S, Gibbons R. Road lighting research for drivers and pedestrians: The basis of luminance and illuminance recommendations. Lighting Research and Technology 2018, 50(1): 154–186.
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Impact factors in LED lamp measurement reproducibility Lighting Res. Technol. (IF 2.226) Pub Date : 2020-11-11 E Gutierrez-Ballesteros; A Gil-de-Castro; S Rönnberg; J Garrido-Zafra
The aim of this paper is to study the reproducibility of measurements in LED lamps. For research purposes as well as for standardized tests, there is a need for measurements to be reproducible so that results can be accurately compared. The knowledge regarding which parameters and test conditions will influence the results is therefore crucial. This paper aims at identifying how changes in supply voltage
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Direct measurement of the contribution of street lighting to satellite observations of nighttime light emissions from urban areas Lighting Res. Technol. (IF 2.226) Pub Date : 2020-10-28 CCM Kyba; A Ruby; HU Kuechly; B Kinzey; N Miller; J Sanders; J Barentine; R Kleinodt; B Espey
Nighttime light emissions are increasing in most countries worldwide, but which types of lighting are responsible for the increase remains unknown. Also unknown is what fraction of outdoor light emissions and associated energy use are due to public light sources (i.e. streetlights) or various types of private light sources (e.g. advertising). Here we show that it is possible to measure the contribution
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Luminance and saliency have impact on pedestrians’ fixation distribution during natural walking: Evidence from mobile eye-tracker Lighting Res. Technol. (IF 2.226) Pub Date : 2020-10-28 X Jiang; J Li; B Yang
The general environmental factors that influence fixation distribution as part of pedestrian visual behaviour under natural conditions are unclear. Relative luminance and saliency are considered the parameters for predicting image-based fixation; however, they are not confirmed by evidence from the natural walking scenario. Field experiments using mobile eye-tracking glasses device were conducted on
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Light reflection spectra as a tool for direct and real-time determination of biomass and pigments in the microalgae Microchloropsis salina Lighting Res. Technol. (IF 2.226) Pub Date : 2020-10-25 Trinh Quang Vinh; Tran Nam Trung; Jens Balasus; Sulabha Sharma; Tim Hegemann; Simon Greulich; Tran Quoc Khanh; Ralf Kaldenhoff
To meet the increasing demand for mass-produced microalgae, production processes must be optimised and monitored. The herein described optical sensors provide an instantaneous and direct opportunity to monitor biological and biochemical information for microalgae cultivation. Combination of expertise in natural science and engineering, as well as the application of novel data acquisition and analysis
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Compact illumination system with variable beam direction and beam divergence Lighting Res. Technol. (IF 2.226) Pub Date : 2020-10-20 N Rondelez; WR Ryckaert; Y Meuret
Countless approaches to optimise lighting conditions for indoor and outdoor applications are described in the literature by adaptive dimming schemes or control algorithms. Those methods rely on adapting the emitted flux of individual luminaires in order to adjust lighting conditions to varying circumstances. Complex illumination requirements are tackled by controlling the output of every independent
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Design method of diffuse transmission free-form surface combined with collimation lens array Lighting Res. Technol. (IF 2.226) Pub Date : 2020-10-14 Zhenmin Zhu; Zhiyu Wang; Fumin Zhang
Lighting-emitting diodes are widely applied in lighting systems, and diffusers are commonly used in systems for indirect illumination. In this paper, a design method of diffuse transmission free-form surface combined with collimation lens array is proposed. Based on the Lambertian characteristics of lighting-emitting diodes and the principle of collimation lenses, a mathematical model of diffuser with
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Influence of text luminance, text colour and background luminance of variable-message signs on legibility in urban areas at night Lighting Res. Technol. (IF 2.226) Pub Date : 2020-10-13 Y He; Y Li; L Xing; Z Qiu; X Zhang
Variable-message signs, which are an important type of traffic sign, have been widely used in traffic control. This study examines the influence of text luminance, text colour and background luminance of variable-message signs on legibility in urban areas under night-time vision. First, the background luminance of variable-message signs in typical urban areas is investigated, tested and classified
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An integrated light management system with real-time light measurement and human perception Lighting Res. Technol. (IF 2.226) Pub Date : 2020-10-12 T Tsesmelis; I Hasan; M Cristani; A Del Bue; F Galasso
Illumination is important for well-being, productivity and safety across several environments, including offices, retail shops and industrial warehouses. Current techniques for setting up lighting require extensive and expert support and need to be repeated if the scene changes. Here we propose the first fully automated light management system which measures lighting in real-time, leveraging an RGBD
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Review of road surface photometry methods and devices – Proposal for new measurement geometries Lighting Res. Technol. (IF 2.226) Pub Date : 2020-10-12 V Muzet; J Bernasconi; P Iacomussi; S Liandrat; F Greffier; P Blattner; J Reber; M Lindgren
Specifications concerning road lighting and photometry of road surfaces were established more than 50 years ago. Road lighting design and road marking visibility were developed for vehicle driving. The observation distance defined by standards corresponds to interurban applications; however, within Europe these areas do not tend to be lit. The objective of the SURFACE project is to propose new geometries
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Editorial: Visual diversity and equity in lighting Lighting Res. Technol. (IF 2.226) Pub Date : 2020-10-12 Michael Royer
For the design of lighting systems in the built environment, the remarkable diversity of the human population is reduced to a single ‘standard’ observer, which forms the basis for most of the metrics used in product characterisation and specification. Although guidance exists for some specific populations, such as seniors and the low vision population, in most lighting research and most buildings the
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Human-centric lighting: Myth, magic or metaphor? Lighting Res. Technol. (IF 2.226) Pub Date : 2020-10-06 KW Houser; PR Boyce; JM Zeitzer; M Herf
This paper discusses the rise of human-centric lighting and its current status in lighting. We summarise the human benefits associated with light and lighting and show that human-centric lighting has sound motivations, despite being tainted by misleading marketing claims. The phrase integrative lighting avoids the hype and encapsulates what lighting aspires to be. Embodied in these concepts are some
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Reconstruction of cumulative daylight illumination fields from high dynamic range imaging: Theory, deployment and in-situ validation Lighting Res. Technol. (IF 2.226) Pub Date : 2020-08-25 J Mardaljevic; S Cannon-Brookes; N Blades; K Lithgow
A novel high-dynamic range camera-based approach to measure the cumulative daylight dose in historic/conservation spaces has been devised and tested in a real-world setting under normal viewing conditions. The technique derives illuminance from the high-dynamic range-acquired luminance at numerous patches of the wall surfaces visible in the high-dynamic range image. These patches serve as proxy illuminance
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Corrigendum to “Calculating luminous flux radiated to a camera lens via high dynamic range photogrammetry” Lighting Res. Technol. (IF 2.226) Pub Date : 2020-08-10
Poling RM, Cai M. Calculating luminous flux radiated to a camera lens via high dynamic range photogrammetry. Lighting Research and Technology First Published 19 May 2020, DOI 10.1177/1477153520921442
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Editorial: Connected lighting and societal impact Lighting Res. Technol. (IF 2.226) Pub Date : 2020-08-10 Ashish Pandharipande
Connected lighting refers to a system of luminaires and sensors that are networked together and have remote connectivity. By leveraging upon LED lighting, information and communication technologies, connected lighting provides several benefits like sustainable energy savings, remote system health monitoring, data-driven insights and a dense infrastructure for realising new smart building and smart
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Designing a laser-cut panel for light collection for daylighting using a generalised mathematical model Lighting Res. Technol. (IF 2.226) Pub Date : 2020-07-30 S Singh; DS Bisht; H Garg
The current daylighting requirements require a system that can maintain a uniform light output throughout the day while enabling deep and controlled penetration of sunlight. If such a system is simple to manufacture, inexpensive and incorporates no moving parts and maintenance, it can easily fulfil all the daylighting needs. This paper focuses on the development of such a system using laser-cut panels
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Effect of driving speed on target visibility under mesopic conditions using a driving simulator Lighting Res. Technol. (IF 2.226) Pub Date : 2020-06-24 D Cao; Y Tu; Z Wang; L Wang; L Liu; Z Chen; D Lou; X Zhu; C Teunissen
This article concerns driving after dark. Control of driving speed, being one aspect of the cognitive load of driving, is an important factor which influences visual performance when driving. However, it is not included as a parameter in the widely used models, such as small target visibility and relative visual performance. A driving simulation platform was established to enable investigation of the
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Testing the residential daylight score: Comparing climate-based daylighting metrics for 2444 individual dwelling units in temperate climates Lighting Res. Technol. (IF 2.226) Pub Date : 2020-06-17 T Dogan; YC Park
Evaluation metrics using climate-based daylight modelling paradigms have become the de-facto standard in work environments but have only limited applicability in residential architecture. Qualities of daylight cited in the architectural design literature, such as daily and seasonal availability of daylight as well as access to direct sunlight, are simulated in detail but are usually overlooked in the
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Quantitative analysis of the stacked autoencoder method in MIMO-ACO-OFDM VLC systems Lighting Res. Technol. (IF 2.226) Pub Date : 2020-06-17 LL Hao; CD Li; DY Wang
In this paper, a stacked autoencoder network is utilised to realise the signal constellation and transceivers adapted to the dimmable indoor visible light communication system in order to acquire lower symbol error probability. Its decoder parts function as denoising and the equaliser for the proposed multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) visible light
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Editorial: Making informed choices Lighting Res. Technol. (IF 2.226) Pub Date : 2020-06-10 Peter Thorns
Life-cycle assessment (LCA) has a long history. However, the meaning of LCA has changed through time.
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Long-term visual quality evaluations correlate with climate-based daylighting metrics in tropical offices – A field study Lighting Res. Technol. (IF 2.226) Pub Date : 2020-06-03 JA Jakubiec; G Quek MArch; T Srisamranrungruang
In this paper, we present a post-occupancy study of 326 participants in 10 daylit office buildings in Singapore and correlate the results with climate-based daylighting metrics and electric lighting simulations using calibrated simulation models of the 10 buildings. For the first time, this study tests the climate-based daylighting metrics which are used in building design against their impact on occupant
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Calculating luminous flux radiated to a camera lens via high dynamic range photogrammetry Lighting Res. Technol. (IF 2.226) Pub Date : 2020-05-19 RM Poling; H Cai
A camera-aided method of using high dynamic range photogrammetry was developed to calculate luminous flux radiated to the camera lens from an environment or its subareas, with per-pixel contributions from visible light-emitting sources, objects, and reflective surfaces. A series of equations were derived to calculate the luminous flux with valid sub-divisibility and additivity. A pilot study was first
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A comparison of approaches for investigating the impact of ambient light on road traffic collisions Lighting Res. Technol. (IF 2.226) Pub Date : 2020-05-12 S Fotios; CJ Robbins; J Uttley
A recent paper proposed a more precise approach for investigating the impact of ambient light (daylight versus after dark) on road traffic collisions. The present paper first repeated that analysis of road traffic collisions in the UK to test reproducibility; it then extended the analysis to determine whether the greater precision affected the outcome of road traffic collision analyses. Results of
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Change of circadian effect with colour temperature and eye spectral transmittance at different ages Lighting Res. Technol. (IF 2.226) Pub Date : 2020-05-11 HJ Tian; T Chen; Y Hu; T Guan; MP Cai
With the recent advances in photobiology research and light-emitting diode technology, considering the circadian effects and the potential health benefits of lighting has attracted much attention. In this work, to achieve a white light-emitting LED cluster with beneficial and tunable circadian effects, a red-green-blue-warm white colour-mixing method based on pulse width modulation has been introduced
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Teasing apart office illumination: Isolating the effects of task illuminance on office workers Lighting Res. Technol. (IF 2.226) Pub Date : 2020-05-07 A de Vries; JL Souman; YAW de Kort
Task illuminance is one of the most used parameters in office lighting design and is often used as a ‘single number criterion’ to verify that a lighting design meets the requirements. Although other parameters, such as wall luminance, are often highly correlated with task illuminance, not taking these explicitly into account means critical user criteria such as comfort and satisfaction are left to
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Editorial: Evaluating research: Do we know what ‘works’? Lighting Res. Technol. (IF 2.226) Pub Date : 2020-05-06 John Mardaljevic
In 2012, an open letter signed by nine Nobel laureates made stinging criticism of the UK Engineering and Physical Sciences Research Council (EPSRC) and called for an urgent review of how funding decisions are made. The signatories of the letter claimed that:
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Recognition of illuminated coloured markers that designate primary and secondary mine escapeways Lighting Res. Technol. (IF 2.226) Pub Date : 2020-04-19 JJ Sammarco; B Demich; BD Macdonald; EN Rubinstein; M Martell
It is critical for the safety of miners to be able to escape, unaided, during a mine emergency. Self-escape is challenging in the presence of smoke that can occur during a mine emergency. To assist self-escape, coloured markers in underground mines designate the primary/secondary escapeways, but no universal colour code exists. Ten participants were tested to recognize the colour and designation (primary/secondary)
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Susceptibility of LED street lamps to voltage dips Lighting Res. Technol. (IF 2.226) Pub Date : 2020-04-14 S Sakar; A Bagheri; S Rönnberg; MHJ Bollen
There is an ongoing transition from high-pressure sodium lamps to LED street lamps that offer higher efficiency, cost saving and better photometric performance. This transition could lead to unintended consequences such as light flicker and extinguishing in street lighting applications when they are exposed to voltage dips. The goal of this paper is to analyse the light intensity variation of various
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Erratum to Effectiveness of an alternative model for establishing mesopic luminance Lighting Res. Technol. (IF 2.226) Pub Date : 2020-04-14
Yao Q, Fotios S. Effectiveness of an alternative model for establishing mesopic luminance. Lighting Research and Technology 2019; 51(6): 900–909. DOI: 10.1177/1477153518800529
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Road lighting and distraction whilst driving: Establishing the significant types of distraction Lighting Res. Technol. (IF 2.226) Pub Date : 2020-04-08 CJ Robbins; S Fotios
There is a body of research showing how changes in lighting conditions affect hazard detection in the context of driving after dark. There is a separate body of research showing that driving is impaired by distraction. The two have yet to be integrated: this is critical for lighting design recommendations because giving consideration to distraction may affect the optimal conditions established in lighting
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Editorial Lighting Res. Technol. (IF 2.226) Pub Date : 2020-04-08 Steve Fotios
In 2018 we published the 50th volume of Lighting Research and Technology. To mark this achievement, issue 50(1) comprised a series of invited articles which focused on several key themes of lighting research, authored by leading researchers in those themes. In the past decade LR&T has increased in extent – both physically (an increase from four to eight issues per year) and geographically (a greater
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The standardisation of light and photometry – A historical review Lighting Res. Technol. (IF 2.226) Pub Date : 2020-04-06 DR Bertenshaw
This paper investigates the technological challenges and solutions to defining a reproducible standard for light together with its measurement, from the 18th to 21st century. The arrival and subsequent need to quantify gas lighting led to development of improved measurement methods, which in turn demanded more reliable standards of light, evolving from candle and flame standards to incandescence, and
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Factors affecting the intention to adopt light-emitting diode lighting at home Lighting Res. Technol. (IF 2.226) Pub Date : 2020-04-02 NI Jaafar; A Sulaiman; S Moghavvemi; FP Tajudeen; F Dehdar
This study investigates the significant factors affecting the adoption of light emitting diode lighting among households in Malaysia by conceptualizing and extending the unified theory of acceptance and use of technology through the adaptation of price value and the anticipated emotions of pride and guilt within the model. This study used the partial least squares technique to validate measurements
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Identifying new concepts for innovative lighting-based interventions to influence movement and behaviours in train stations Lighting Res. Technol. (IF 2.226) Pub Date : 2020-03-13 N Hughes; B Ryan; M Hallewell; N Coad; A Grant; N Parrott; S Roberts; K Thompson
The disorderly and disrupted movement of passengers within train stations are key concerns in rail transport, especially where there are increasing numbers of passengers, coupled with often out-dated, adapted station spaces. With careful planning and design, different characteristics of lighting can be employed to address problems relating to the movement and behaviour of passengers in railway environments
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Research Note: Describing average illuminance for P-class roads Lighting Res. Technol. (IF 2.226) Pub Date : 2020-03-13 S Fotios; C Robbins
Design criteria for lighting in subsidiary roads usually include a minimum average horizontal illuminance, widely assumed to be the arithmetic mean illuminance. Analyses of the illuminance distributions over thirty road sections shows that the distributions are not normal and hence the median is more appropriate than the arithmetic mean as a measure of central tendency: the medians are significantly
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Towards better lighting recommendations for open surgery Lighting Res. Technol. (IF 2.226) Pub Date : 2020-02-25 H Hemphälä; W Osterhaus; PA Larsson; J Borell; P Nylén
The visual conditions in an operating theatre/operating room/surgical suite are essential for adequate work performance of clinical staff and absolutely critical for patient safety. It is common that the illuminance level varies greatly across the operating theatre space, causing large luminance contrasts between the centre beam of the surgical luminaire, the lighting in the operating area and the
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Design of a high-efficiency system with combined reflectors for a light-emitting diode front fog lamp Lighting Res. Technol. (IF 2.226) Pub Date : 2020-02-23 E Yang; A Ge; Y Liu; B Zhao; R Hao
This paper provides a design method for a light-emitting diode front fog lamp system based on a freeform surface and an improved quadric surface. First, a light-receiving reflector is used to converge the light-emitting diode beam to form an equivalent lighting point. Then, the relationship between the point and the light pattern on the work surface is calculated, and the freeform surface is constructed
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Illuminance meter calibration with an LED spectrally tunable light source Lighting Res. Technol. (IF 2.226) Pub Date : 2020-02-19 K Godo; Y Tamura; O Watari
Calibration of an illuminance meter is indispensable for accurate measurement of the illuminance of indoor lighting and daylight. In recent years, because of the phasing-out of incandescent lamps and their replacement with LED lamps, it has become difficult to obtain an incandescent type standard lamp to calibrate an illuminance meter. To replace the standard lamp method, we constructed an illuminance
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An assessment of a hybrid lighting system that employs ultraviolet-A for mitigating healthcare-associated infections in a newborn intensive care unit Lighting Res. Technol. (IF 2.226) Pub Date : 2020-02-17 JA Brons; A Bierman; R White; K Benner; L Deng; MS Rea
Hospital patients are at risk from infections acquired there. Approximately 1 in 25 patients in the United States contract healthcare-associated infections (HAIs).1 Patients are particularly at risk if the previous patient in that room had an infection.2,3 Standard cleaning procedures usually involve manual application of detergents and disinfectants.4 The efficacy of these manual cleaning procedures
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Detection of the stroboscopic effect by young adults varying in sensitivity Lighting Res. Technol. (IF 2.226) Pub Date : 2020-02-12 JA Veitch; C Martinsons
The introduction of solid-state lighting to the marketplace has brought renewed concern about possible adverse consequences of exposure to temporal cyclic or transient variations in lighting system luminous flux, known as temporal light modulation (TLM) (or more commonly referred to as ‘flicker’). TLM may have visual, neurobiological, performance and cognitive effects on viewers.1–3 Visual perception
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Road lighting: A pilot study investigating improvement of visual performance using light sources with a larger gamut area Lighting Res. Technol. (IF 2.226) Pub Date : 2020-02-09 B Yang; M Wei
Many past studies investigating visual performance focused mainly on the effect of luminance contrast between the target and background. Other studies have suggested the importance of colour contrast on visual performance. This pilot study was designed to investigate whether visual performance in the context of road lighting can be improved by enhancing the chroma of targets. Observers were asked to
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Effect of long-wavelength light on electroencephalogram and subjective alertness Lighting Res. Technol. (IF 2.226) Pub Date : 2020-02-05 J Lin; S Westland
This study extends previous findings on the effect of different levels of short-wavelength light on human alertness. This study explores the alerting ability of long-wavelength light at two levels (40 lx and 160 lx). Eight subjects took part in the 60-minute experiment for each of two nights, during which their objective alertness and subjective alertness were evaluated using electroencephalogram and
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Research note: LED lighting – A global enterprise Lighting Res. Technol. (IF 2.226) Pub Date : 2020-01-29 SB Reese; K Horowitz; M Mann; T Remo
There is considerable focus on technology manufacturing locations and the value in funding innovation when upstream products are not manufactured within a domestic economy. Light-emitting diodes (LEDs) are such an upstream product. Here, we evaluate the value added along the supply chain of luminaires, a product that utilizes LEDs, using bottom-up cost modelling. Coupling the results with analysis
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Parallax errors in cubic illuminance measurement Lighting Res. Technol. (IF 2.226) Pub Date : 2020-01-24 RA Mangkuto, PhD; Revantino, MSc
The cubic illuminance concept has long been proposed to indicate light modelling in three-dimensional space. An issue relatively less discussed with regard to its measurement is the potential error due to the finite size of the cube centred at the reference point, yielding a parallax effect. In short, the measured cubic illuminance around a finite-sized object will differ from the designed values that
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Effects of illuminance and contrast on the reading of Chinese text by myopes Lighting Res. Technol. (IF 2.226) Pub Date : 2020-01-20 J Bao; R Tan; J Huo; B Drobe; H Chen
Twenty-four young adults with myopia in both eyes and no anisometropia participated in this study. Observers were instructed to read one A4-sized page of Chinese text at different levels of illuminance and text contrast, while their reading distance, head tilt angle and reading speed were recorded using an electromagnetic motion tracking system. Four illuminances (3, 30, 300 and 600 lx) and two text
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