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Open-Source Python Module for the Analysis of Personalized Light Exposure Data from Wearable Light Loggers and Dosimeters LEUKOS (IF 3.6) Pub Date : 2024-02-28 Grégory Hammad, Katharina Wulff, Debra J. Skene, Mirjam Münch, Manuel Spitschan
Light exposure fundamentally influences human physiology and behavior, with light being the most important zeitgeber of the circadian system. Throughout the day, people are exposed to various scene...
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The Effect of Light on Negative Emotion and Cognitive Regulation in Individuals with Depressive Tendencies LEUKOS (IF 3.6) Pub Date : 2024-02-02 Li Zhou, Chao Ruan, Nuoyi Li, Dandan Hou, Christopher Weirich, Yandan Lin
Light has been demonstrated to influence transient mood states in healthy populations and can be used as a treatment for clinical mood disorders. However, it is still interesting to know whether st...
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Evaluating Emerging Spectral Lighting Software: Comparing Measurements of Light Spectrum and Derived Metrics in a One-Room Laboratory Environment with Simulation Results LEUKOS (IF 3.6) Pub Date : 2024-01-29 Sarah Safranek, Corey Strachan, Robert G. Davis
The goal of this study was to evaluate the use of new spectral simulation tool, Adaptive Lighting for Alertness (ALFA), by comparing software-predicted values of spectral irradiance, illuminance, a...
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Effects of Temporal Light Modulation on Individuals Sensitive to Pattern Glare LEUKOS (IF 3.6) Pub Date : 2024-01-29 Jennifer A. Veitch, Naomi J. Miller
Solid-state lighting systems can vary widely in the degree of temporal light modulation (TLM) of their light output. TLM is known to have visual, cognitive, and behavioral effects but there are few...
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Effects of Personalized Lighting on Subjective Ratings, Cognitive Performance, and Physiological Stress Response in a Simulated Office Environment LEUKOS (IF 3.6) Pub Date : 2024-01-23 Maximilian Dick, Wilfried Pohl, Helmut K. Lackner, Elisabeth M. Weiss, Markus Canazei
LEDs simplify the personalization of lighting. However, research on the effects of personalizable lighting is in its infancy. The present study investigates the impact of personalizable workplace l...
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Sunlight Autonomy for Buildings: A New Methodology for Evaluating Sunlight Performance in Urban and Architectural Design LEUKOS (IF 3.6) Pub Date : 2024-01-23 Arlind Dervishaj, Kjartan Gudmundsson
Due to urbanization and growing density in cities in the past century, metrics were introduced to assess daylight performance such as minimum sunlight hours and the daylight factor. The paper initi...
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On the Assignment of Target/Ambient Illuminance Ratio in Designing Mean Room Surface Exitance LEUKOS (IF 3.6) Pub Date : 2024-01-23 Rizki A. Mangkuto
In the application of lighting design objectives (LiDOs) procedure, the target first reflected flux (FRF) may at times underestimate or overestimate the expected FRF based on the specified mean roo...
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Diurnal Intervention Effects of Electric Lighting on Alertness, Cognition, and Mood in Healthy Individuals: A Systematic Review and Meta-Analysis LEUKOS (IF 3.6) Pub Date : 2023-12-01 YanJie Li, WeiNing Fang, HanZhao Qiu, WenLi Dong, JianXin Wang, HaiFeng Bao
Non-image forming effects of electric light can be employed to address problems related to individuals’ productivity in isolated and confined extreme environments (ICEs). A systematic review and me...
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The Use of Virtual Screens in Perceptual Studies on Electric Light: A Comparison Between 2D, Panoramic, Cardboard, and Head-Mounted Displays LEUKOS (IF 3.6) Pub Date : 2023-11-30 Siobhan Francois Rockcastle, Galen Sollom-Brotherton Whalen, Aaron Milgrim, Robert Davis
This paper introduces the results of an experiment on lighting perception and reading speed where data collected in a physical space is compared to that collected in representations of that space s...
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The Impact of Target Object Size and Dimensionality on the Degree of Adaptation to Global Illumination LEUKOS (IF 3.6) Pub Date : 2023-11-16 Shining Ma, Ming Ronnier Luo, Ruoduan Sun, Yue Liu, Yongtian Wang, Weitao Song
Chromatic adaptation is an important visual phenomenon that specifically influences color appearance under various illumination conditions. There were extensive studies investigating the impact of ...
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Assessment of Window Size and Layout Impact on a View Quality Perception in a Virtual Reality Environment LEUKOS (IF 3.6) Pub Date : 2023-10-24 Fedaa Abd-Alhamid, Michael Kent, Yupeng Wu
Window views are key factors that affect buildings’ occupants psychological and physiological comfort and wellbeing. Window design should consider the holistic impacts on building energy, lighting ...
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Recommended Method for Determining the Correlated Color Temperature and Distance from the Planckian Locus of a Light Source LEUKOS (IF 3.6) Pub Date : 2023-09-13 Kevin Smet, Michael Royer, Doug Baxter, Eric Bretschneider, Tony Esposito, Kevin Houser, Wendy Luedtke, Kwong Man, Yoshi Ohno
Correlated color temperature (CCT) is one of the primary metrics used to characterize the visual appearance of light and is most informative when coupled with distance from the Planckian locus (Duv...
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Evaluation of Inrush Current in LED Luminaires Applied to Urban Lighting Based on Multi-Criteria Decision-Making Methods: A Case Study LEUKOS (IF 3.6) Pub Date : 2023-09-13 Juan de Dios Unión-Sánchez, Manuel Jesús Hermoso-Orzáez, Blas Ogáyar-Fernández, Julio Terrados-Cepeda
In recent years, a progressive renovation of public lighting has been taking place in cities, from metal halide lamps to LED luminaires. This renovation has been carried out on a large scale by rep...
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Effects of Luminance Contrast on Depth Perception in Optical See-Through Augmented Reality LEUKOS (IF 3.6) Pub Date : 2023-07-18 Jingyuan Wang, Shining Ma, Yue Liu, Yongtian Wang, Weitao Song
Augmented reality (AR) technology presents the rendered virtual object in the real world whose depth cues can assist the depth estimation of the virtual object. For many AR applications, the succes...
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Heliotropic Shading: Daylighting a Rare Books Reading Room with Electrochromic Glass and Parametric Analysis LEUKOS (IF 3.6) Pub Date : 2023-07-12 Dan Weissman
This paper introduces the design process and successful deployment of an electrically tintable glass, known as electrochromic glazing, for a fully daylit atrium sheltering a rare books reading room...
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Assessing the Effects of Polychromatic Light Exposure on Mood in Adults: A Systematic Review Contrasting α-opic Equivalent Daylight Illuminances LEUKOS (IF 3.6) Pub Date : 2023-07-12 Ashley Nixon, Rebecca Robillard, Chloe Leveille, Alan B. Douglass, Meggan Porteous, Jennifer A. Veitch
This is a systematic review of studies assessing the effects of polychromatic (white) ambient light on mood in healthy adults. We hypothesized that higher melanopic equivalent daylight illuminances...
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The Influence of Vertical Illuminance on Cognitive Performance and Subjective Evaluations during Simulated Conditions of Polar-Night Specificity LEUKOS (IF 3.6) Pub Date : 2023-06-15 Huiling Cai, Qingcheng Lin, Hanwei Liu, Maocang Tian, Xuefeng Li, Hui Xiao
The natural light environment in polar regions is different in that there are midnight sun and polar night rather than a regular year-round alternation of day and night. Existing research has repor...
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Optimizing Presence Sensing Lighting for Energy Efficiency and User Behavioral Needs in Small Swedish Homes LEUKOS (IF 3.6) Pub Date : 2023-05-30 RatnaKala Sithravel, Thomas Olsson, Myriam Aries
A hybrid workstyle is becoming more common post-COVID-19, and longer occupancy hours at home are increasing household electricity consumption. Small homes are regarded as a potential for improving ...
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Effects of Temporal Light Modulation on Cognitive Performance,Eye Movements, and Brain Function LEUKOS (IF 3.6) Pub Date : 2023-04-18 Jennifer A. Veitch, Patricia Van Roon, Amedeo D’Angiulli, Arnold Wilkins, Brad Lehman, Greg J. Burns, E. Erhan Dikel
Temporal light modulation (TLM) describes variations in light output from a light source or lighting system and can be a characteristic of their normal operation. TLM at 100 or 120 Hz can disrupt e...
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Modifications of the Robertson Method for Calculating Correlated Color Temperature to Improve Accuracy and Speed LEUKOS (IF 3.6) Pub Date : 2023-03-02 Doug Baxter, Michael Royer, Kevin Smet
Correlated color temperature (CCT) is one of the principal metrics used in the engineering and specification of lighting. One of the most common methods used for calculating CCT was first proposed ...
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Capturing Luminous Flux Entering Human Eyes with a Camera, Part 2: A Field Verification Experiment LEUKOS (IF 3.6) Pub Date : 2023-02-13 Siqi He, Hankun Li, Yonghong Yan, Hongyi Cai
A space occupant’s real-time exposure to light reaching his/her eyes has been a concern in lighting research and design practice. Following the parallel fundamental research in Part 1, Part 2 of th...
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LEUKOS Editor Report, Reflections, and Farewell LEUKOS (IF 3.6) Pub Date : 2023-01-30 Kevin W. Houser
Published in LEUKOS: The Journal of the Illuminating Engineering Society (Vol. 19, No. 2, 2023)
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Continuous Overcast Daylight Autonomy (DAo.con): A New Dynamic Metric for Sensor-Less Lighting Smart Controls LEUKOS (IF 3.6) Pub Date : 2023-01-19 Ignacio Acosta, Miguel Ángel Campano, Samuel Domínguez-Amarillo, Jaime Navarro Casas
ABSTRACT Daylight dynamic metrics are useful tools for quantifying the switch-on time or the dimming of electric lighting according to the architectural scenario. A variant of these metrics can also be used to define strategies to control the lighting fixtures, dimming the luminous flux with no need for external input and reducing therefore the energy consumption of the lighting systems. Given this
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Specifying Non-White Light Sources in Outdoor Applications to Reduce Light Pollution LEUKOS (IF 3.6) Pub Date : 2023-01-05 Tony Esposito, Leora C. Radetsky
ABSTRACT Anthropogenic (“human-generated”) light at night (ALAN) from outdoor lighting produces light pollution and as a result causes a range of deleterious responses in humans, plants, and animals. An emerging strategy to combat light pollution, especially sky glow, is to use “amber” LEDs in lieu of phosphor-converted white LEDs with high correlated color temperatures. Importantly, however, there
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Capturing Luminous Flux Entering Human Eyes with a Camera, Part 1: Fundamentals LEUKOS (IF 3.6) Pub Date : 2022-12-29 Siqi He, Hankun Li, Yonghong Yan, Hongyi Cai
A space occupant’s real-time exposure to light reaching his/her eyes has been a concern in lighting research and design practice. This study assumed a schematic eye to estimate the luminous flux re...
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Eco-redesign of Lighting Products LEUKOS (IF 3.6) Pub Date : 2022-12-26 Jose L. Casamayor, Daizhong Su, You Wu
ABSTRACT Although there are numerous published studies that have helped to enhance our understanding about methods or approaches to eco-design products, there are limited publications that focus on the study of eco-redesign of lighting products. Redesign of existing products is one of the most applied design-related activities in industry, and eco-redesign is one of the most suitable eco-design interventions
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Recommendations on the Correlated Color Temperature of Light Sources for Traditional Chinese Paper Relics in Museums LEUKOS (IF 3.6) Pub Date : 2022-12-16 Rui Dang, Wei Liu, Huijiao Tan
As an important substrate of traditional Chinese cultural relics in museums, paper is the material with highly light sensitivity, which is susceptible to irreversible lighting damage. To provide hi...
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A Grid in Perspective for Road Lighting Calculations LEUKOS (IF 3.6) Pub Date : 2022-12-15 Florian Greffier, Vincent Boucher, Valérie Muzet, Sandy Buschmann, Stephan Völker
ABSTRACT In road lighting, calculations are made within the rectangular CIE grid while measurements conducted with Imaging Luminance Measurement Devices (ILMD) have a trapezoidal shape. We propose to build a grid that takes the observer’s perspective into account by projecting ellipses of adjustable dimensions than can match human vision or ILMD angular aperture and allow direct comparison with luminance
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Evaluating Luminance Uniformity Metrics Using Online Experiments LEUKOS (IF 3.6) Pub Date : 2022-12-15 Belal Abboushi, Lia Irvin, Eduardo Rodriguez-Feo Bermudez, Michael Royer
ABSTRACT Luminance uniformity of luminaires is an important design aspect that can affect perceived discomfort glare, luminaire efficiency, and visual satisfaction. There is, however, a lack of studies that evaluated the performance of different luminance uniformity metrics. This article presents results of two studies where luminance patterns were presented via online questionnaires and subjective
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Modelling the Probability of Discomfort Due to Glare at All Levels: The Case of Outdoor Lighting LEUKOS (IF 3.6) Pub Date : 2022-12-13 Joffrey Girard, Céline Villa, Roland Brémond
ABSTRACT To limit glare, lighting engineers need to estimate the level of discomfort produced by a lighting installation. Outdoor, most discomfort glare models predict a mean level of discomfort on a judgment scale, which corresponds to a “mean road user.” However, in real life, the inter-individual variability of the sensitivity to glare is large; predicting the mean discomfort does not describe the
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Buildings, Lighting, and the Myopia Epidemic LEUKOS (IF 3.6) Pub Date : 2022-12-06 Kevin W. Houser, Lisa Heschong, Richard Lang
Published in LEUKOS: The Journal of the Illuminating Engineering Society (Vol. 19, No. 1, 2023)
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Towards a Design Procedure Based on Peoples’ Responses to Indoor Lighting LEUKOS (IF 3.6) Pub Date : 2022-11-17 Christopher Cuttle
ABSTRACT On the basis that an effective lighting design procedure should enable practitioners to reliably achieve positive responses from the people who will experience the lighting, the effectiveness of current practice is found lacking in that it is largely unrelated to peoples’ responses. Additionally, the calculation procedures widely used for devising indoor lighting solutions require the user
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Photoreceptor Enhanced Light Therapy (PELT): A Framework for Implementing BiologicallyDirected Integrative Lighting LEUKOS (IF 3.6) Pub Date : 2022-10-24 Beatrix Feigl, Drew D. Carter, Andrew J. Zele
ABSTRACT We introduce a lighting technology designed to produce photoreceptor-directed lights (PrD). This photoreceptor-enhanced light therapy (PELT) differs from conventional supplemental lighting by using multiple limited-bandwidth primaries to generate spectra that appear white, and that are tailored to produce circadian equivalent (CE) lights for selectively increasing or decreasing the relative
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Trees in Daylight Simulation – Measuring and Modelling Realistic Light Transmittance through Trees LEUKOS (IF 3.6) Pub Date : 2022-10-04 Priji Balakrishnan, J. Alstan Jakubiec
ABSTRACT Trees influence daylight availability inside and outside buildings by attenuating, scattering, and transmitting light. They resemble a complex fenestration around buildings that change in form, materiality, and permeability based on species of trees, seasonal variations, and environmental or human interventions. The current practice of modeling trees in daylight simulations ignores this complexity
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Fairness and Bias in Peer Review: Anonymity, Open Science, and Preprints LEUKOS (IF 3.6) Pub Date : 2022-08-18 Kevin W. Houser
Published in LEUKOS: The Journal of the Illuminating Engineering Society (Vol. 18, No. 4, 2022)
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Data-Driven Selection of Typical Opaque Material Reflectances for Lighting Simulation LEUKOS (IF 3.6) Pub Date : 2022-08-11 J. Alstan Jakubiec
ABSTRACT Lighting simulation standards recommend default values for opaque material reflectance values, but these are varied and not based upon measured data. In response, a database of 1,288 opaque material reflectance measurements collected using spectrally specific spectrophotometer sensors is presented. The database is analyzed according to object type, material type, and color. Photopic, melanopic
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A Review of Illuminance Mapping Practices from HDR Images and Suggestions for Exterior Measurements LEUKOS (IF 3.6) Pub Date : 2022-07-26 Arpan Guha, Alayne Nyboer, Dale K. Tiller
ABSTRACT High Dynamic Range (HDR) imaging has traditionally been used to create photorealistic images by combining multiple Low Dynamic Range (LDR) images. The application of HDR imaging has been since expanded to study the lighting environment by extraction of metrics such as luminance, illuminance, and glare. While luminance mapping of HDR images has been extensively studied in the recent past, research
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Predicting Window View Preferences Using the Environmental Information Criteria LEUKOS (IF 3.6) Pub Date : 2022-07-26 Michael G Kent, Stefano Schiavon
ABSTRACT Daylighting standards provide an assessment method that can be used to evaluate the quality of window views. As part of this evaluation process, designers must achieve five environmental information criteria (location, time, weather, nature, and people) to obtain an excellent view. To the best of our knowledge, these criteria have not yet been verified and their scientific validity remains
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Improved Methods for Computing CCT and Duv LEUKOS (IF 3.6) Pub Date : 2022-07-20 Yue Li, Cheng Gao, Manuel Melgosa, Changjun Li
ABSTRACT Recently, Ohno proposed a method for computing the correlated color temperature (CCT) of a light source and the shortest distance (with sign) between its chromaticity and that of the Planckian locus (Duv). In Ohno’s method, firstly a lookup table is chosen, and then a hybrid method based on the triangular and parabolic solutions is used to predict the CCT and Duv of a given light source. In
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Visual Comfort and Acute Alerting Effects of Diurnal Intermittent Bright Light LEUKOS (IF 3.6) Pub Date : 2022-07-20 M. E. Kompier, K. C. H. J. Smolders, L. J. M. Schlangen, Y. A. W. de Kort
ABSTRACT Intermittent bright light during the night has shown to be able to generate circadian phase-shifting effects, suppress melatonin and induce alertness, but little attention has been devoted to the effects of diurnal intermittent bright light. Following a night of sleep restriction, forty participants were exposed in a counterbalanced within-subject design to an intermittent (100 lux – 1000
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Optical Lock-in Spectrometry Reveals Useful Spectral Features of Temporal Light Modulation in Several Light Source Technologies LEUKOS (IF 3.6) Pub Date : 2022-06-22 Christophe Martinsons, Nicolas Picard, Samuel Carré
ABSTRACT This paper presents a study of the spectral characteristics of temporal light modulation in several technologies of lighting products. An optical lock-in spectrometer was designed for this purpose and integrated in a spectral radiant flux measurement facility. It was applied to incandescent and fluorescent lamps, as well as lamps based on white phosphor-converted LEDs and tunable RGB LEDs
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Accuracy of Hyperspectral Imaging Systems for Color and Lighting Research LEUKOS (IF 3.6) Pub Date : 2022-06-21 Aiman Raza, Dominique Dumortier, Sophie Jost-Boissard, Coralie Cauwerts, Marie Dubail
ABSTRACT This study aims to compare different hyperspectral imaging devices and identify their suitability for in-situ color and lighting research. Three hyperspectral cameras were compared for radiometric, photometric, and colorimetric accuracy. The visual quality of the images obtained with each device was also evaluated to test their suitability for psychophysical experiments on color perception
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Window View Quality: Why It Matters and What We Should Do LEUKOS (IF 3.6) Pub Date : 2022-05-06 Won Hee Ko, Stefano Schiavon, Sergio Altomonte, Marilyne Andersen, Ayesha Batool, William Browning, Galen Burrell, Kynthia Chamilothori, Ying-Chieh Chan, Giorgia Chinazzo, Jens Christoffersen, Nancy Clanton, Christopher Connock, Timur Dogan, Billie Faircloth, Luís Fernandes, Lisa Heschong, Kevin W. Houser, Mehlika Inanici, Alstan Jakubiec, Anjali Joseph, Caroline Karmann, Michael Kent, Kyle Konis,
(2022). Window View Quality: Why It Matters and What We Should Do. LEUKOS: Vol. 18, No. 3, pp. 259-267.
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Lighting System Control Data to Improve Design and Operation: Tunable Lighting System Data from NICU Patient Rooms LEUKOS (IF 3.6) Pub Date : 2022-05-05 Andrea Wilkerson, Sarah Safranek, Lia Irvin, Lauri Tredinnick
ABSTRACT The advancement of LED and controls technology, computing capacity, and software provides new opportunities for researchers and designers to work together to further optimize spaces for occupant benefit. Lighting system control data from five neonatal intensive care unit patient rooms was collected over a 25-week monitoring period and analyzed to better understand occupant response to a tunable
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A Novel Approach for the Assessment of the Nocturnal Image of the Cultural Landscape LEUKOS (IF 3.6) Pub Date : 2022-04-28 Lodovica Valetti, Franco Pellerey, Anna Pellegrino
ABSTRACT Policies aimed at urban and territorial development stressed the importance of landscape as a significant resource for sustainable and economic development. In this perspective, research on landscape visual values and people preferences can support the enhancement of the global values of territories. Currently, the theoretical framework and approaches are mainly limited to the day images of
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Utilization of far-red LED to minimize blue light hazard for dynamic semiconductor lighting LEUKOS (IF 3.6) Pub Date : 2022-04-01 Jingxin Nie, Zhizhong Chen, Fei Jiao, Yifan Chen, Jinglin Zhan, Yiyong Chen, Zuojian Pan, Xiangning Kang, Yongzhi Wang, Qi Wang, Weimin Dang, Wentian Dong, Shuzhe Zhou, Xin Yu, Yuzhen Tong, Guoyi Zhang, Bo Shen
ABSTRACT The blue light hazard (BLH) and luminous efficacy of a source ( ηV) are associated with the photobiological safety and energy saving of light-emitting diodes (LEDs), respectively. In this study, we used genetic algorithm (GA) to optimize the BLH, ηV, and color rendering parameters of five-chip hybrid white LEDs. Based on the optimal results, we used five-chip LEDs to obtain the hybrid white
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Improved Method for Evaluating and Specifying the Chromaticity of Light Sources LEUKOS (IF 3.6) Pub Date : 2022-03-07 Michael Royer, Michael J. Murdoch, Kevin Smet, Lorne Whitehead, Aurélien David, Kevin Houser, Tony Esposito, Jason Livingston, Yoshi Ohno
ABSTRACT This article describes a method for calculating and specifying light source chromaticity using the International Commission on Illumination (CIE) 2015 10° color matching functions (CMFs), which, according to analysis of existing psychophysical experiment data, can reduce visual mismatch compared to specifications based on the traditional CIE 1931 2° CMFs in architectural lighting applications
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Regional Differences in the Perception of Daylit Scenes across Europe Using Virtual Reality. Part II: Effects of Façade and Daylight Pattern Geometry LEUKOS (IF 3.6) Pub Date : 2022-02-18 K. Chamilothori, J. Wienold, C. Moscoso, B. Matusiak, M. Andersen
ABSTRACT While there is a growing use of complex façade designs in contemporary architecture worldwide and across Europe, little is known about the perceptual effects of these façades and the resulting daylight patterns on occupants, or about how such effects might differ between European latitudes. This study examines the perception of façade and daylight patterns across Europe by replicating a virtual
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To Measure Is to Know … or Not LEUKOS (IF 3.6) Pub Date : 2022-02-16 Kevin W. Houser
(2022). To Measure Is to Know … or Not. LEUKOS: Vol. 18, No. 2, pp. 103-103.
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Reconstruction of Daylight Spectral Power Distribution Based on Correlated Color Temperature: A Comparative Study between the CIE Approach and Localized Procedures in Assessing Non-image Forming Effects LEUKOS (IF 3.6) Pub Date : 2022-02-15 Aicha Diakite-Kortlever, Nils Weber, Martine Knoop
ABSTRACT Spectrally and spatially resolved information on daylight is critically important when planning for non-image forming (NIF) responses. Nevertheless, the availability of such data is scarce given the high initial costs and complex on-site maintenance of high-end spectral measurement devices. The CIE (Commission Internationale de l’Éclairage) reconstruction procedure allows for the derivation
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Let Me Count the Light. Accounting for Intensity, Duration and Timing of Light When Predicting Sleep and Subjective Alertness in Field Studies LEUKOS (IF 3.6) Pub Date : 2022-01-20 S.T. Peeters, K.C.H.J. Smolders, M.E. Kompier, Y.A.W. de Kort
ABSTRACT Throughout the day, we are exposed to light that varies drastically over time. Correct quantification of the light is important when predicting sleep and subjective alertness in the field, yet doing so, is a complex challenge. In the current manuscript, we explore the feasibility of a novel, practical method to quantify light exposure, based on the data collected in two field studies (in late
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Road Marking Contrast Threshold Revisited LEUKOS (IF 3.6) Pub Date : 2021-12-16 Rik Marco Spieringhs, Kevin Smet, Ingrid Heynderickx, Peter Hanselaer
ABSTRACT Sufficient contrast between road surface and road markings is key for a safe and comfortable driving experience. This calls for a comprehensive and well established contrast (threshold) model, which ideally results in a single contrast threshold value independent of object angular size or road luminance. The contrast threshold model introduced by Adrian is still commonly used in road lighting
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A Window View Quality Assessment Framework LEUKOS (IF 3.6) Pub Date : 2021-11-10 Won Hee Ko, Michael G. Kent, Stefano Schiavon, Brendon Levitt, Giovanni Betti
ABSTRACT The views that windows provide from inside a building affect human health and well-being. Although window view is an important element of architecture, there is no established framework to guide its design. The literature is widely dispersed across different disciplinary fields, and there is a need to coalesce this information into a framework that can be applied into the building design.
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Certainty and Doubt LEUKOS (IF 3.6) Pub Date : 2021-10-29 Kevin W. Houser
(2022). Certainty and Doubt. LEUKOS: Vol. 18, No. 1, pp. 1-1.
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Effect of Correlated Color Temperature and S/P-ratio of LED Light Sources on Reaction Time in Off-axis Vision and Mesopic Lighting Levels LEUKOS (IF 3.6) Pub Date : 2021-10-05 E. G. Vicente, B. M. Matesanz, M. Rodríguez-Rosa, A. M. Sáez, S. Mar, I. Arranz
ABSTRACT The increasing replacement of traditional lamps by LED technology opens the door to research into visual performance under their multiple possible spectral power distributions. The correlated color temperature and S/P-ratio are considered parameters characterizing the spectrum of a light source. The lack of firm conclusions motivates the analysis in this work of the influence of LED spectrum
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On Illumination Vector Quantities Due to Area Light Sources: Comparison of Two Calculation Approaches LEUKOS (IF 3.6) Pub Date : 2021-09-09 Rizki A. Mangkuto, Mochamad Donny Koerniawan
ABSTRACT The concept of illumination vector quantities at a given point in three-dimensional space has been proposed since long time ago, but it is mostly described for scenes with point light sources. In real scenes with area light sources, numerical approximations are required to estimate the illumination vector quantities, which can be done by discretising the area into an array of point sources
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Discomfort Glare from a Cyclic Source in Outdoor Lighting Conditions LEUKOS (IF 3.6) Pub Date : 2021-08-26 Joffrey Girard, Céline Villa, Roland Brémond
ABSTRACT Many models of discomfort glare have been proposed for outdoor lighting applications. Most of them were built from data collected in the laboratory in static situations, with motionless light sources, which main characteristics (luminance, size and position) were constant over time. However, on the road at night, drivers are moving with multiple sources around them. To fill the gap between
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Effectiveness of Light Source Efficiency for Characterization of Colored Surface Luminance LEUKOS (IF 3.6) Pub Date : 2021-08-26 Peiyu Wu, Yi Lin, Qi Yao
ABSTRACT The lamp spectrum and the surface reflection both contribute to the luminous efficiency of the illuminated object. Hence, it may not be comprehensive to evaluate the luminous efficiency in a lighting environment only through the metrics with respect to lamps. Previous studies have investigated the effect of surface reflection on luminous efficiency, but few quantitative metrics have been proposed
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The Impact of Exterior Surround Detail on Daylighting Simulation Results LEUKOS (IF 3.6) Pub Date : 2021-08-10 Reza Sadeghi, Richard Mistrick
ABSTRACT The accuracy of daylighting simulations for the built environment strongly depends on the modeling of the exterior surround. The practice of modeling a space with a flat ground surface with little or no external architectural or landscape elements, particularly early in the design phase, is often applied. In this study, this approach and a number of different levels of detail for modeling
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Ethics and Fallacies of Human-Centric Lighting and Artificial Light at Night LEUKOS (IF 3.6) Pub Date : 2021-08-04
(2021). Ethics and Fallacies of Human-Centric Lighting and Artificial Light at Night. LEUKOS: Vol. 17, No. 4, pp. 319-320.