Lighting Research Papers - Academia.edu (original) (raw)

- by
- •
- Retail Design, Atmosphere, Lighting
- by Ian Holliday
- •
- Motion perception, Visual acuity, Lighting, Contrast sensitivity

Evidence linking home hazards to falls has not been well established. The evidence-based approach to fall-risk assessment in longitudinal studies becomes difficult because of exposures that change during follow-up. We conducted a cohort study to determine the prevalence of hazards and to resolve whether they are linked to the risk of falls among 959 seniors receiving home-care services. A home hazards assessment was completed at entry and every six months thereafter using a standardized form. The adjusted (for a number of confounding factors) relationship between home hazards and falls was estimated using a survival model taking into account updated time-varying exposures and multiple events. Falls leading to a medical consultation were examined as a secondary outcome, hypothesized as a measure of severity. Home environmental hazards were found in 91% of homes, with a mean of 3.3 risks per individual. The bathroom was the most common place for hazards. The presence of hazards was si...

- by Nicole Leduc
- •
- Nonparametric Statistics, Risk assessment, Quebec, Linear models

This study examined whether the conspicuity of road workers at night can be enhanced by distributing retroreflective strips across the body to present a pattern of biological motion (biomotion). Twenty visually normal drivers (mean age = 40.3 years) participated in an experiment conducted at two open-road work sites (one suburban and one freeway) at nighttime. At each site, four road workers walked in place wearing a standard road worker night vest either a) alone, b) with additional retroreflective strips on thighs, c) with additional retroreflective strips on ankles and knees, or d) with additional retroreflective strips on eight moveable joints (full biomotion). Participants, seated in stationary vehicles at three different distances (80 m, 160 m, 240 m), rated the relative conspicuity of the four road workers. Road worker conspicuity was maximized by the full biomotion configuration at all distances and at both sites. The addition of ankle and knee markings also provided significant benefits relative to the standard vest alone. The effects of clothing configuration were more evident at the freeway site and at shorter distances. Overall, the full biomotion configuration was ranked to be most conspicuous and the vest least conspicuous. These data provide the first evidence that biomotion effectively enhances conspicuity of road workers at open-road work sites.

- by ralph marszalek
- •
- Psychology, Visual perception, Attention, Motion perception

Light-emitting diodes (LEDs) come in many varieties and with a wide range of radiation patterns. We propose a general, simple but accurate analytic representation for the radiation pattern of the light emitted from an LED. To accurately render both the angular intensity distribution and the irradiance spatial pattern, a simple phenomenological model takes into account the emitting surfaces (chip, chip array, or phosphor surface), and the light redirected by both the reflecting cup and the encapsulating lens. Mathematically, the pattern is described as the sum of a maximum of two or three Gaussian or cosine-power functions. The resulting equation is widely applicable for any kind of LED of practical interest. We accurately model a wide variety of radiation patterns from several world-class manufacturers.

- by Ivan Moreno
- •
- Computer Aided Design, Semiconductors, Computer Simulation, Lighting

Purpose: To prospectively determine the diagnostic accuracy of optical absorption imaging in patients with Breast Imaging Reporting and Data System (BI-RADS) 3-5 breast lesions. Materials and methods: Forty-six patients with BI-RADS classification 3 (11%), 4 (44%) or 5 (44%) lesions, underwent a novel optical imaging examination using red light to illuminate the breast. Pressure was applied on the breast, and time-dependent curves of light absorption were recorded. Curves that consistently increased or decreased over time were classified as suspicious for malignancy. All patients underwent a core or surgical biopsy. Results: Optical mammography showed a statistical difference in numbers of suspect pixels between benign (N = 12) and malignant (N = 35) lesions (respectively 1325 vs. 3170, P = 0.002). In this population, optical imaging had a sensitivity of 74%, specificity of 92%, and diagnostic accuracy of 79%. The optical signal did not vary according to any other parameter including breast size or density, age, hormonal status or histological type of lesions. Conclusion: Optical imaging is a low-cost, non-invasive technique, yielding physiological information dependent on breast blood volume and oxygenation. It appears to have a good potential for discriminating benign from malignant lesions. Further studies are warranted to define its potential role in breast cancer imaging.

- by Corinne Balleyguier
- •
- Algorithms, Photography, Breast Cancer, Adolescent

ABSTRACT: Cassava is one of the most important food crops in Africa. Meristem culture is an effective method of eliminating viruses and other systemic diseases spread through the vegetative propagation of stems. However, in semi-arid conditions, survival of ex vitro plants in the field is often disappointing. When an increasing range of light regimes in vitro was provided, the fresh and dry masses more than doubled their values between 29 and 369 mmol s−1 m−2 PPFDs. Increases in numbers of senescent leaves and stem thickness were also recorded with increasing PPFD. However, PPFD above 101 mmol s−1 m−2 resulted in 30–70% reduction in plant survival, with the thin plants with the smallest fresh and dry masses being the ones with highest survival rates. High light and temperature levels in the greenhouse were also found to be critical for plant survival. It was also shown that transpirational loss from detached leaves and epicuticular wax deposits were not good indicators for predicting survival of ex vitro cassava plantlets during acclimatisation.

- by Arnold Bray Mashingaidze
- •
- Cassava, Lighting, In vitro culture, Acclimatization

During the past few years, organic light emitting diodes (OLEDs) have been increasingly studied due to their emerging applicability. However, some of the properties of existing OLEDs could be improved, such as their overall efficiency and durability; these aspects have been addressed in the current study. A series of novel hole-transporting materials (HTMs) 3a-c based on 4-(9H-carbazol-9-yl)triphenylamine conjugated with different carbazole or triphenylamine derivatives have been readily synthesized by Suzuki coupling reactions. The resulting compounds showed good thermal stabilities with high glass transition temperatures between 148 and 165 °C. The introduction of HTMs 3b and 3c into the standard devices ITO/HATCN/NPB/HTMs 3 (indium tin oxide/dipyrazino(2,3-f:2',3'-h)quinoxaline…

- by Na Vee Valiente Shin
- •
- Organic Chemistry, Organic light emitting diodes, Lighting, Luminescence

Human vision works in a complex way in the mesopic luminance range which is not yet clearly understood, although several important visual tasks are performed at these luminance levels. In this study, spectral data for detection visibility and recognition contrast sensitivity were obtained in visual experiments. From our data it appears that chromatic channels also influence mesopic contrast sensitivity. An achromatic model of spectral sensitivity is fitted to our experimental data and the remaining chromatic components are discussed.

- by Géza Várady
- •
- Binocular vision, Lighting, Reaction Time, Contrast sensitivity

Versatility in the design of optical systems is one of the key features of light-emitting diodes (LEDs) that has attracted considerable attention. In the analysis of systems using LEDs, it is useful to know if the distance is far enough from the LED to allow the radiation pattern to be simulated by the point source approach. We propose three far-zone conditions for LED light modeling: the far-field distance, and for practical purposes the quasi far-field and minimum far-field distances. Different types of LEDs have different far-field ranges. We analyze these differences by modulating key parameters like geometrical structure of encapsulating lens, chip size, chip shape, chip position, and package errors. We find that far-field region considerably depends more on the shape of both lens and chip than all other parameters.

- by Ivan Moreno
- •
- Optical Engineering, Computer Aided Design, Semiconductors, Computer Simulation
- by Geza Benke
- •
- Australia, Information, Lighting, Cataract

Residential buildings are responsible for a large share of the total energy consumption. It is well-known that the correct use of natural and artificial lighting can improve energy efficiency. However, lighting in residential buildings should meet other requirements: safety, security, health, comfort, well-being and functional performance. This paper presents an analysis of how these requirements have been incorporated in the Portuguese building regulatory system. The analysis focuses on the regulatory framework, certification systems, incentive programs and awareness initiatives. The main conclusion is that the regulatory system lays down provision mainly on functional performance and energy saving. Lighting requirements regarding safety, security, health, comfort and well-being are often neglected or minimized in regulatory documents. Specialized documents and initiatives present a comprehensive approach. Daylighting design is a challenge, due to its complexity, but has potential ...

Vasarely's 'nested-squares' illusion is the perception of a glowing ''X" along the diagonals of concentric squares with a luminance gradient. We present here the chromatic Vasarely effect, where the concentric angles have a chromatic gradient, under iso-brightness conditions. The strength of the effect was tested psychophysically by two measures, the length and the color of the illusory folds. The color of the illusory fold is perceived as the complementary color of the color of the nested-squares (or angles). The experimental results show that a large repertoire of stimuli with different colors and angles yielded significantly perceived colors. The results show that the strength of the perceived illusory fold (of both the length and the chroma) is significantly larger at sharper angles of the stimuli. The chromatic first-order adaptation computational model predicts most of the above results.

- by Hedva Spitzer
- •
- Psychophysics, Visual perception, Color Perception, Vision
- by Paul Brain and +1
- •
- Zoology, Animal Behavior, Research, Animal Husbandry

How do levels of cognitive workload differ between experienced and inexperienced drivers? In this study we explored cognitive workload and driver experience, using a secondary task method, the peripheral detection task (PDT) in a field study. The main results showed a large and statistically significant difference in cognitive workload levels between experienced and inexperienced drivers. Inexperienced, low mileage drivers had on average approximately 250 milliseconds (ms) longer reaction times to a peripheral stimulus, than the experienced drivers. It would, therefore, appear that drivers with better training and experience were able to automate the driving task more effectively than their less experienced counterparts in accordance with theoretical psychological models. It has been suggested that increased training and experience may provide attention resource savings that can benefit the driver in handling new or unexpected traffic situations.

- by Albert Kircher and +1
- •
- Psychology, Cognition, Attention, Lighting

To investigate how light intensity changes as the distance increases from the tip of the light guide. Ten different curing light/light guide combinations were used. Light intensity was measured at 0, 3, 6, and 10 mm from the tip of the light guide with a radiometer. Measurements were repeated in five separate trials and the mean light intensity +/- standard deviation was calculated. The fiber density was measured at the entrance and exit of all ten light guides and the light dispersion patterns were recorded. Light intensity decreased as distance increased for all lights tested; however, the rate and extent of this decrease was not similar for all lights (p < 0.0001). Turbo light guides exhibited a more rapid decrease in intensity as the distance increased than standard light guides. At 10 mm, all the turbo light guides had lost over 80% of their intensity recorded at 0 mm. 1. The rate and extent of the decrease in intensity is not similar among curing lights (p < 0.0001). 2. ...

- by Richard Price
- •
- Materials Science, Dentistry, Lighting, Light

reason moon luminance increases rapidly with altitude, from 2 cd/m 2 up to over 4000. 3 Accordingly, the moon can appear off-white, white, fluorescent, or luminous -variations that are not predicted by Retinex theory.

- by Paola Bressan
- •
- Color Perception, Color, Illusions, Lighting

The short-wavelength (blue) light sensitivity of human non-visual responses is recognised as being melanopsin-based. However, whether melanopsin is the sole factor in determining the efficacy of a polychromatic light source in driving non-visual responses remains to be established. Monochromatic (λ max 437, 479 and 532 nm) and polychromatic (colour temperature: 4000 K and 17000 K) light stimuli were photon matched for their predicted ability to stimulate melanopsin, and their capacity to affect nocturnal melatonin levels, auditory reaction time and subjective alertness and mood was assessed.

- by Luc Schlangen and +2
- •
- Chronobiology, Adolescent, Biological Sciences, Affect

Objectives: The aim of this study was to conduct a field study to survey the performance of digital radiography and how it was used by dentists in general dental practice. Methods: Nineteen general dental practitioners were visited at their clinics. Ambient light (illuminance) was measured in the rooms where the monitors were placed. Different technical display parameters were noted. Test images and two phantoms-one low-contrast phantom and one line-pair resolution phantom-were used to evaluate the digital system. How the dentists used the enhancement program was investigated by noting which functions were used. Results: Average illuminance in the operating room was 668 lux (range 190 -1250 lux). On radiographs of the low-contrast phantom taken at the clinic, the ability to observe the holes decreased as illuminance increased. On average, the "light percentage" initially set on the monitor had to be decreased by 17% and contrast by 10% to optimize the display of the test images. The general dental practitioners used the enhancement programs most often to alter brightness and contrast to obtain the subjectively best image. Large differences between the clinics were noted. Conclusion: Knowledge of how to handle digital equipment in general dental practice should be improved. A calibrated monitor of good quality should be a given priority, as should proper ambient light conditions. There is a need to develop standardized quality controls for digital dental radiography.

- by Arne Petersson
- •
- Dentistry, Semiconductors, Quality Control, Sweden
- by Sandy Isenstadt
- •
- Urban History, Lighting

Assessing how uniform the light distribution is throughout an illuminated target is important in many applications, but traditional methods do not quantify the variability of illuminance as the human visual system (HVS) does. Considering that most light patterns are intended for humans, I propose a simple metric that assesses the uniformity in a similar way as humans do. This uniformity indicator is based on the fact that the HVS is highly sensitive to spatial frequencies and then uses the Fourier transform and the contrast sensitivity function of the HVS in a practical way.

- by Ivan Moreno
- •
- Quantum Physics, Visual perception, Lighting, Light

Two early studies showed that visual prompts can be effectively used to encourage people to turn off the lights in unoccupied classrooms, but they were methodologically limited. The current study used an ABAB-B design with an 11-week follow-up to investigate whether two different visual prompts (large and small signs) could be employed to increase "lights off" behaviour in 17 unoccupied washrooms. The odds were eight times higher that lights would be turned off in washrooms with signs than washrooms without, and large signs trended toward being more effective than small signs. Signs in washrooms with windows appeared to be the most effective, but this finding merits further research. Behaviour change persisted throughout the follow-up period, but reactance by a single washroom user resulted in some signs being removed. Compared to previous research, the current study used an improved methodology with a larger number of study sites. This study demonstrated that a simple, well-designed sign can effectively encourage energy conservation.

- by Robert Gifford
- •
- Communication, Research Design, Environmental Psychology, Energy Conservation

Humans rarely confuse variations in light intensity, such as shadows, shading, light sources and specular reflections, from variations in material properties, such as albedo or pigment. This review explores the cues, or regularities in the visual world that evidence suggests vision exploits to discriminate light from material. These cues include luminance relations, figural relations, 3D-shape, depth, colour, texture, and motion. On the basis of an examination of the cues together with the behavioural evidence that they are used by vision, I propose a set of heuristics that may guide vision in the task of distinguishing between light and material. I argue that while there is evidence for the use of these heuristics, little is known about their relative importance and the manner in which they are combined in naturalistic situations where there are multiple cues as to what is light and what is material. Finally, I discuss two theoretical frameworks, the generic view principle and Bayesian estimation, that are beginning to help us understand the visual processes involved in distinguishing between light and material.

- by Frederick Kingdom
- •
- Psychophysics, Motion perception, Color Perception, Visual Processing
- by Gamaliel Azcorra
- •
- Physics, Lighting

Mit ihrer SchattenTrilogie, die die Installationsperformances "Die Scheinwerferin" (2011), "Absolute Helligkeit" (2012) und "Unverinnerlicht" (2015) umfasst, hat sich die an den Grenzen von bildender Kunst und szenischer Installationskunst agierende Naoko Tanaka nicht nur im gesamten Bundesgebiet (mit Vorstellungen u.a. in Berlin, Leipzig, Essen, Hannover, Düsseldorf) einen Namen gemacht, sondern auch auf internationaler Ebene (mit Gastspielen u.a. in Japan, Frankreich, Belgien, Österreich, Schweiz, Italien, Serbien, Polen, Portugal). Die SchattenTrilogie vereint drei eigenständige und doch aufeinander bezogene, objekt- und bildbasierte, atmosphärisch dichte Auseinandersetzungen mit Licht und Schatten, die die Künstlerin als technisch-mediale Phänomene ebenso interessieren wie als Sinnbild für existenzielle Fragen. Um die Performances kreisen wie Satelliten Skizzen und Zeichnungen, Vorarbeiten der Künstlerin, Fotografien, die Einblicke in die Vorbereitung und Einrichtung der Szene und die Anfertigung der Objekte geben, sowie ein poetischer Text von Yoko Tawada und wissenschaftliche Essays von Hartmut Böhme, Gabriele Brandstetter und Adam Czirak, die sich als Angebote verstehen, mit Tanakas Arbeiten ins Gespräch zu kommen.
Das Buch erscheint zunächst auf Deutsch, im Herbst 2017 auch in einer englischen und in einer japanischen Ausgabe.

- by Astrid Hackel and +1
- •
- Philosophy, Aesthetics, Visual Studies, Perception
- by Fernando Cuadros Lopez
- •
- Primary Care, Air pollution, Energy Management, Spain

The lighting conditions, luminance, contrast, and design of the workplace were studied in video display terminal (VDT) work stations operated by a group of female VDT data-acquisition clerks. VDT-induced symptoms were assessed by means of subject answers to a questionnaire To measure VDTinduced ocular fatigue objectively, refraction power was determined before and at the end of workshift by an infrared autorefractometer Job-induced refraction changes were then related to visual complaints and conditions in the workplace The results confirmed that VDT data-acquisition work can lead to temporary myopia (myopization) in a remarkable percentage of operators; a significant correlation between eye discomfort, ocular asthenopia, and myopization was also found Illumination levels, luminance, and contrast seem to be of paramount importance regarding visual symptoms: neither asthenopia nor myopization was observed when all of these conditions were adequate If the ergonomic design of the workplace and the viewing distance are adequate, there are also usually fewer musculoskeletal symptoms Our results suggest that changes in the ocular refraction status before and at the end of the workshift, as determined by an automatic refractometer, provide a good objective index of VDT-induced "ocular fatigue", which in our study proved to be significantly related to workplace conditions.

- by Fabriziomaria Gobba
- •
- Myopia, Computer Systems, Lighting, Data acquisition

وجود پارک ها در خط ساحلی می تواند به جذب مخاطب به این فضاها کمک کند. پارک های شهری و به طور خاص بخشی از فضاهای سبز عمومی هستند که بازدهی اجتماعی دارند و عموم مردم از آنها در گذران اوقات فراغت ،تفریح و مصاحبت با دوستان و گردهمایی اجتماعی و نظایر اینها استفاده می کنند . شب هنگام فضاهای شهری پارک ها به عنوان فضاهای زنده ،متنوع مملو از عبور و مرور مورد استفاده قرار می گیرند، هدف این پژوهش به بررسی نقش نورپردازی بر افزایش حس دعوت کنندگی در یکی از پارک های ساحلی شهر بندرعباس پرداخته است. از این رو روش مصاحبۀ نیمه ساختاری در جهت جمع آوری داده ها برای این پژوهش انتخاب شده ونمونۀ آماری از 33 نفر به صورت حضوری مصاحبه شده است و نتایج مصاحبه با نرم افزار اکسل به صورت جدول دسته بندی شده است. پارک غدیر که داده ها در آن مکان جمع آوری شده است یک پارک ساحلیست که با توجه به پاسخ اکثریت مصاحبه شوندگان ساحل را عامل جذابیت پارک می دانستند و در آن مکان خاطره دارند. با توجه به پاسخ مصاحبه شوندگان مسیرهای پیاده روی در بعضی از نقاط به علت عدم نورپردازی مناسب در شب مورد استفاده قرار نمی گیرد. یکی از دلایل حضور مردم در پارک ها فعالیت هایی است که در آن پارک انجام می شود و حضور مردم باعث سرزندگی فضاها می شود. حضور افراد مختلف و انجام فعالیت های ورزشی و تفریحی متنوع در پارک بعنوان یکی از دلایل حضور مردم در این پارک شناخته شده است. از این رو نورپردازی در پارک ها باید به گونه ای باشد که رهگذران در آرامش باشند و فضا امکان انجام فعالیت های مختلف را برای مردم فراهم کند، شهر در شب با حضور انسان تعریف می شود و نورپردازی مناسب فضاهای شهری می تواند خاطره ساز شده و در حافظه جمعی شهر بنشیند که یافته ها نشان داده خوانایی ، هویت، تنوع ، امنیت ،سرزندگی در افزایش حس دعوت کنندگی درپارک تاثیر دارد. بدین ترتیب نورپردازی و رو شنایی یک شهر در شب می تواند به گونه ای در شناسایی هرچه بیشتر شهر و حضورپذیری افراد کمک کند

- by Zeinab Aliyas
- •
- Environmental Psychology, Urban Parks, Urban Public Open Space, Lighting
- by Dominique Bressoud
- •
- Photochemistry, Biological Sciences, Ultraviolet, Lighting

Contrary to the implication of the term “lightness constancy”, asymmetric lightness matching has never been found to be perfect unless the scene is highly articulated (i.e., contains a number of different reflectances). Also, lightness constancy has been found to vary for different observers, and an effect of instruction (lightness vs. brightness) has been reported. The elusiveness of lightness constancy presents a great challenge to visual science; we revisit these issues in the following experiment, which involved 44 observers in total. The stimuli consisted of a large sheet of black paper with a rectangular spotlight projected onto the lower half and 40 squares of various shades of grey printed on the upper half. The luminance ratio at the edge of the spotlight was 25, while that of the squares varied from 2 to 16. Three different instructions were given to observers: They were asked to find a square in the upper half that (i) looked as if it was made of the same paper as that on which the spotlight fell (lightness match), (ii) had the same luminance contrast as the spotlight edge (contrast match), or (iii) had the same brightness as the spotlight (brightness match). Observers made 10 matches of each of the three types. Great interindividual variability was found for all three types of matches. In particular, the individual Brunswik ratios were found to vary over a broad range (from .47 to .85). That is, lightness matches were found to be far from veridical. Contrast matches were also found to be inaccurate, being on average, underestimated by a factor of 3.4. Articulation was found to essentially affect not only lightness, but contrast and brightness matches as well. No difference was found between the lightness and luminance contrast matches. While the brightness matches significantly differed from the other matches, the difference was small. Furthermore, the brightness matches were found to be subject to the same interindividual variability and the same effect of articulation. This leads to the conclusion that inexperienced observers are unable to estimate both the brightness and the luminance contrast of the light reflected from real objects lit by real lights. None of our observers perceived illumination edges purely as illumination edges: A partial Gelb effect (“partial illumination discounting”) always took place. The lightness inconstancy in our experiment resulted from this partial illumination discounting. We propose an account of our results based on the two-dimensionality of achromatic colour. We argue that large interindividual variations and the effect of articulation are caused by the large ambiguity of luminance ratios in the stimulus displays used in laboratory conditions.

- by Alexander Tokunaga
- •
- Psychology, Cognitive Science, Psychophysics, Individuality
- by Trevor R Norman
- •
- Bipolar Disorder, Biological Sciences, Melatonin, Lighting

Artificial lighting systems are transitioning from incandescent to compact fluorescent lamp (CFL) and light-emitting diode (LED) bulbs in response to the U.S. Energy Independence and Security Act and the EU Ecodesign Directive, which leads to energy savings and reduced greenhouse gas emissions. Although CFLs and LEDs are more energyefficient than incandescent bulbs, they require more metal-containing components. There is uncertainty about the potential environmental impacts of these components and whether special provisions must be made for their disposal at the end of useful life. Therefore, the objective of this study is to analyze the resource depletion and toxicity potentials from the metals in incandescent, CFL, and LED bulbs to complement the development of sustainable energy policy. We assessed the potentials by examining whether the lighting products are to be categorized as hazardous waste under existing U.S. federal and California state regulations and by applying life cycle impact-based and hazardbased assessment methods (note that "life cycle impact-based method" does not mean a general life cycle assessment (LCA) but rather the elements in LCA used to quantify toxicity potentials). We discovered that both CFL and LED bulbs are categorized as hazardous, due to excessive levels of lead (Pb) leachability (132 and 44 mg/L, respectively; regulatory limit: 5) and the high contents of copper (111 000 and 31 600 mg/kg, respectively; limit: 2500), lead (3860 mg/kg for the CFL bulb; limit: 1000), and zinc (34 500 mg/kg for the CFL bulb; limit: 5000), while the incandescent bulb is not hazardous (note that the results for CFL bulbs excluded mercury vapor not captured during sample preparation). The CFLs and LEDs have higher resource depletion and toxicity potentials than the incandescent bulb due primarily to their high aluminum, copper, gold, lead, silver, and zinc. Comparing the bulbs on an equivalent quantity basis with respect to the expected lifetimes of the bulbs, the CFLs and LEDs have 3−26 and 2−3 times higher potential impacts than the incandescent bulb, respectively. We conclude that in addition to enhancing energy efficiency, conservation and sustainability policies should focus on the development of technologies that reduce the content of hazardous and rare metals in lighting products without compromising their performance and useful lifespan.

- by Daniel Kang and +1
- •
- Fluorescence, Multidisciplinary, Environmental science and technology, Copper

Background: Eighty per cent of adolescents globally do insufficient physical activity. Parks are a popular place for adolescents to be active. However, little is known about which park features are associated with higher levels of park... more

- by Paula Hooper
- •
- Education, Health Behavior, Australia, Adolescent

Despite the considerable injury burden attributable to falls at home among the general population, few effective safety interventions have been identified. We tested the safety benefits of home modifications, including handrails for outside steps and internal stairs, grab rails for bathrooms, outside lighting, edging for outside steps, and slip-resistant surfacing for outside areas such as decks and porches. We did a single-blind, cluster-randomised controlled trial of households from the Taranaki region of New Zealand. To be eligible, participants had to live in an owner-occupied dwelling constructed before 1980 and at least one member of every household had to be in receipt of state benefits or subsidies. We randomly assigned households by electronic coin toss to either immediate home modifications (treatment group) or a 3-year wait before modifications (control group). Household members in the treatment group could not be masked to their assigned status because modifications were...

- by Philippa Howden-chapman
- •
- Adolescent, Child, Lighting, New Zealand

This work investigated the degrees to which energy use in laboratory buildings may be influenced by interior space planning and/or the ways space is used. The potential influences of typical open, mixed and closed plan layouts and their space utilisation densities/intensities were investigated on a good-practice base case using the TAS, Lightscape and Excel software packages. The peak winter results indicated variations (potential savings) generally within a range of 40% (i.e., +20% of the respective base cases loads) except for the effect of open vs closed plans, which resulted in a variation of 73%. The summer load variations are within 50% across the open, mixed and closed layouts, and 84% across different closed plan layouts. These results indicate that the different ways in which users, activities and systems are organised against space-to-space environmental diversity are significant determinants of the energy performance of laboratories and perhaps other building types.

- by F Musau
- •
- Architecture, Energy efficiency, Simulation, Building

Economic value of cotton fiber is by far superior to that of any other natural fiber. And when it comes to trade, cotton fiber and its value added products, the grading of cotton fiber is of high importance which depends upon different properties. Color is one of those important properties which play a vital role in the cotton selection. Currently used system for the color classification in the cotton world is not that much reliable when keeping in view the importance of fiber. Mostly before the purchase of cotton fiber, a professionally trained visual cotton inspector gives grade to the cotton which is later on confirmed in the mills by HVI which measures Rd and +b values in order to grade the cotton fiber. The grade given by visual inspection not only varies from the HVI grading but, also has contradiction among the cotton classers who are professionally trained. In this study we will try to find out the relationship between the visual classification and the instrumental classification of cotton fiber by keeping in view the universal standards for cotton grading. So, different instrumental methods for color measurements will be used and their relationships will be the main objective of the study.

- by Michal Vik and +2
- •
- Physics, Quality Management, Colorimetry, Lighting

This paper proposes a novel image-based framework to manipulate the illumination of human face through adaptive layer decomposition. According to our framework, only a single reference image, without any knowledge of the 3D geometry or material information of the input face, is needed. To transfer the illumination effects of a reference face image to a normal lighting face, we first decompose the lightness layers of the reference and the input images into large-scale and detail layers through weighted least squares (WLS) filter with adaptive smoothing parameters according to the gradient values of the face images. The large-scale layer of the reference image is filtered with the guidance of the input image by guided filter with adaptive smoothing parameters according to the face structures. The relit result is obtained by replacing the largescale layer of the input image with that of the reference image. To normalize the illumination effects of a non-normal lighting face (i.e., face delighting), we introduce similar reflectance prior to the layer decomposition stage by WLS filter, which make the normalized result less affected by the high contrast light and shadow effects of the input face. Through these two procedures, we can change the illumination effects of a non-normal lighting face by first normalizing the illumination and then transferring the illumination of another reference face to it. We acquire convincing relit results of both face relighting and delighting on numerous input and reference face images with various illumination effects and genders. Comparisons with previous papers show that our framework is less affected by geometry differences and can preserve better the identification structure and skin color of the input face. . His current research interests include visual computing and computer vision.

- by Xin Jin
- •
- Cognitive Science, Algorithms, Computer Graphics, Face Recognition

Resumo O presente trabalho aborda a questão da influência da temperatura de cor da luz artificial LED juntamente com a luz natural e seus efeitos não visuais no padrão circadiano de seres humanos. Dessa forma, foi realizado um estudo sobre a interferência da iluminacao artificial no ciclo circadiano dos indivíduos, a qual esta intimamente relacionada a regulação de estimulos, tais como, períodos vigília-sono, apetite, relaxamento, alerta, entre outros. Um ponto interessante, e que, ate pouco tempo, partindo do ponto de vista do projeto luminotecnico, a relação entre o sistema endócrino, responsável por regular os hormonios no corpo humano, e a iluminação era pouco considerada. Entretanto, recentemente, estudos indicam uma forte relacao entre o bom funcionamento deste relógio biológico e à variação de temperaturas de cores da luz natural durante o dia. Sendo assim, em meio a um contexto o qual tecnologias novas estão sendo criadas e difundidas a cada dia, as pessoas estão cada vez mais expostas a utilização de iluminação artificial por meio de aparelhos eletronicos. E, salvo algumas excessões lançadas recentemente no mercado, tais aparelhos não possuem a capacidade de configurar a variacao da temperatura de cor durante o dia, ocasionando alterações no ciclo circadiano e consequentemente na saúde dos usuários do ambiente. Portanto, além de estudar a interferência da iluminação artificial, o trabalho visa indicar soluções para minimizar os efeitos da iluminação noturna residencial afim de melhorar a saúde e a qualidade de vida dos usuários, por meio de soluções fáceis de serem adotadas. Dessa forma, é imperativo que além de projetar ambientes bem iluminados, realçando os elementos do espaço, exista a preocupaçao por parte dos arquitetos e profissionais do ramo em projetar ambientes que proporcionem qualidade de vida as pessoas, salientando a necessidade de se pensar na iluminação artificial voltada para com enfoque no ritmo biológico dos usuários, cada vez mais orientado para o ser humano, influenciando positivamente na saúde. Palavras-chave: Ciclo circadiano. Iluminação. LED Azul. Luz e saúde. Melatonina. 1. Introdução Para Feldman (2007:19) a arquitetura se enquadra dentro das ciências sociais onde os aspectos qualitativos constituem parte fundamental do estudo e deliberações visando a qualidade de vida das pessoas concomitantemente com a própria natureza. Sob a perspectiva da qualidade da iluminação do ambiente residencial, os controles poderiam ser aproveitados para aumentar a flexibilidade, funcionalidade e estética de um ambiente. A luz é fundamental ao homem e sem ela não há vida. A luz é radiação eletromagnética capaz de sensibilizar o olho humano. Os seres humanos que possuem 100% da visão ou algo próximo a isso, são pessoas menos dependentes dos outros sentidos: paladar, audição, tato e olfato, quando comparados a indivíduos que apresentam diferentes estágios de perdas

- by Erika Almeida
- •
- Design, Architecture, Circadian Rhythms, Well-Being

Endodontic surgery is an alternative therapeutic approach to endodontic treatment. The outcome of the technique is affected by several factors, some of which can be eliminated by the use of a dental operating microscope. The microscope was used during the performance of 50 apicoectomies, with or without retrograde fillings. For clinical evaluation cases treated with the dental operating microscope were compared to cases treated without it. The postoperative evaluation showed a reduced incidence of symptoms in the cases treated with the dental operating microscope. More important, the dental operating microscope enhanced and facilitated each phase of endodontic surgery. Its use is highly recommended.

- by Gabriele Pecora and +1
- •
- Microsurgery, Treatment Outcome, Lighting, Tooth Root

La nuit n’est pas un espace-temps inexploré par le géographe [Deleuil, 1994 ; Fiori, 2000 ; Mosser et Devars, 2000 ; Paquot, 2000 ; Gwiazdzinski, 2002, 2005 ; Mos- ser, 2003, 2005, 2007 ; Mallet, 2009], mais il reste jeune et nécessite donc d’être observé, afin d’être cerné, dans une globalité parfois déroutante, mais souvent sti- mulante. Si la nuit, et plus spécifiquement la nuit urbaine, a effectivement été ap- préhendée par le chercheur, il s’agit souvent – encore aujourd’hui – d’analyser comment cet espace-temps peut être optimisé dans ses différents usages, notamment par la lumière artificielle qui les accompagne. Prenant le contre-pied de ces démarches, nous proposons ici de montrer le renversement qui s’opère actuelle- ment quant aux considérations de cette lumière artificielle, la faisant passer du statut quasi-exclusif de progrès technologique à celui d’une source de gêne, de nuisance, voire même de pollution.

- by Samuel Challéat
- •
- Geography, Human Geography, Light Pollution/Observing Sites, Lighting

Only studies of quartz halogen lamps have suggested that users might sustain UVC-induced injury. Examination of light sources in the home and school of a child with xeroderma pigmentosum revealed that several different types emitted surprising levels of UV. Our purpose was to assess the extent of UV emissions from a variety of commonly used light sources to identify potential dermatological risks. UV and visible spectral emissions of commercially obtained lamps of several types were measured using a calibrated spectral radiometer traceable to the National Institute of Standards and Technology. Indoor light sources including fluorescent, quartz halogen and even tungsten filament incandescent lamps provided UVA, UVB and sometimes UVC emissions. Intensities of some emissions were of similar magnitude to those in sunlight. Chronic exposure to indoor lighting may deliver unexpected cumulative UV exposure to the skin and eyes. Patients with UV-exacerbated dermatoses should be cautioned about potential adverse reactions from indoor lighting.

- by John Dowdy
- •
- Photochemistry, Biological Sciences, Ultraviolet, Lighting

- by Ivan Moreno
- •
- Computer Aided Design, Semiconductors, Computer Simulation, Lighting
- by Jose Manuel Susperregui
- •
- Publicidad, Lighting, Fotografia, Iluminación