Lighting Arrangements Research Articles

Yellow is green: An opportunity for energy savings through colour in architectural spaces

• The spatial brightness of spaces painted with different colours was compared. • Three spaces were built and illuminated with three lighting arrangements. • The spaces were assessed by observers and measured, and the results were compared. • Time, surface colour and light level affected the light perception. • Lighting energy savings can be obtained with the use of surface colour. Today, the building sector is one of the greatest energy consumers of the world. Therefore, it is important that designers think about strategies to save energy at the different stages of the building process, including during its life. Considering that a great deal of energy will be spent in artificial lighting, an improvement in the performance in front of light of the architecture itself could lead to a better vision of the spaces, which depends on the quantity and quality of light available and on the architectural characteristics as well. One of the most influential aspects is the colour of the space. Here, a case study is presented in which three coloured spaces were assessed by observers under different lighting conditions. Luminance and illuminance measurements were taken to compare these values with the votes given. The results query the correlation between measured values and luminosity of three-dimensional spaces. As a consequence, the choice of a particular colour may increase the sensation of light in a space and, therefore, a reduction of energy use in artificial lighting is possible. In addition, architectural design can take advantage of colour to improve the visual quality of indoor spaces.

MULTIMODALITY IMAGING OF DAGUERREOTYPES AND DEVELOPMENT OF A REGISTRATION PROGRAM FOR IMAGE EVALUATION

This study documented 260 of the whole-plate daguerreotypes of Southworth and Hawes at George Eastman House International Museum of Photography and Film using several imaging techniques in order to generate a baseline or benchmark of condition. Various existing imaging modalities—such as high-resolution scans using modified flat-bed scanners, full-frame digital cameras with special lighting arrangements for high dynamic range (HDR), long-wave ultra violet radiation (UVA) induced fluorescence, and axial specular imaging—were refined to capture the fine surface features of daguerreotypes. The methodology used here can guide other conservators interested in documenting daguerreotypes. The accumulation of a wide range of visual information of daguerreotypes from the various imaging modalities led to the development of an open source image registration (alignment) program for multimodality image comparison. The affine transform registration algorithm is based on user-defined point pairs between two images that are used to describe the displacements between them. After correcting for image shearing, rotation, scaling, and translation, the images can be directly compared allowing additional observations.

A visual perception effect assessment of some large and broad-leaved trees under different lighting arrangements

This experimental study concentrates on how different lighting arrangements affect visual perceptions of plant lighting. Five different lighting arrangements of three tree species were prepared; the differences between the participants’ perceptions of each lighting arrangement were analysed and the effects of the different lighting arrangements were determined. Consequently, these applied lighting techniques were observed to be effective in creating visual perceptions of plants. In this particular study of plant-lighting alternatives, the objective was to determine which techniques created the most positive effects.

マスト灯の間隔が他船の避航判断に及ぼす影響について- 護衛艦あたごと漁船清徳丸の衝突を例に -

The accident between Atago and Seitokumaru has been reproduced using a ship handling simulator and 13 captains of patrol crafts of Japan Coast Guard have observed the target vessel Atago from the view point of Seitokumaru and they have answered a questionnaire on the target vessel in length, the crossing angle between Atago's course and Seitokumaru's course and on a method of a collision avoidance with Atago. Where, the overall length of Atago is 165 meters and the horizontal distance between her two masthead lights is about 10 meters. In order to investigate effects of the arrangement of the masthead lights, the target vessel is replaced by an ordinary cargo vessel which is almost same size of Atago and the same simulation has been conducted. In case of Atago, 10 captains have estimated her length to be at least 50m shorter than the real value and 10 captains have estimated the crossing angle to be at least 35 degrees larger than the real value and 8 captains have selected to pass Atago's bow. In case of the cargo vessel, 3 captains have estimated her length to be at least 50m shorter than the real value and 2 captains have estimated the crossing angle to be at least 35 degrees larger than the real value and 11 captains have selected to pass the stern of the cargo vessel.

渋谷区立宮下公園における要求性能に基づいた低照度光環境の計画と評価

Outdoor lighting design is usually carried out to clear the Recommended Levels of Illumination(JIS Z 9110). In contrast, this research tried to renovate the Miyashita Park located in Shibuya-ku based on the lighting performance design. Since the facilities were converted to barrier-free, strong lighting was no longer required to satisfy walk performance. Performances required for lighting were investigated first, and then a lighting experiment which examines arrangement of lights for ensuring the performances was conducted. As a result of comparing before and after renovation, by distributing the minimum lights which ensure the performance, the whole visibility improved and the consumption energy also decreased.

Pewarnaan Simpul Dengan Algoritma Welch-Powell Pada Traffic Light Di Yogyakarta

Traffic congestion is a problem which is often found in big cities in Indonesia. This requires a range of solutions, one of them with the settings of the traffic light. Traffic light arrangement can be completed with graph theory. Part of graph theory a graph coloring is used. Staining graf three i.e. coloring is differentiated into a knot, staining the sides, and staining region. This research examines the arrangements about traffic light using colorization algorithm Welch knot with Powell. The intersection of Data represented in the graph, which is then solved by coloring the vertices, then look for the value of the effective duration of the time compared to a traffic light settings occur at several intersections in Yogyakarta. Completion of traffic light arrangement using staining nodes provide alternative solutions duration lit the red light and green light is more effective than the secondary data at several intersections in Yogyakarta.

Neural network modeling of the light profile in a novel photobioreactor

An artificial neural network (ANN) was implemented to model the light profile pattern inside a photobioreactor (PBR) that uses a toroidal light arrangement. The PBR uses Tequila vinasses as culture medium and purple non-sulfur bacteria Rhodopseudomonas palustris as biocatalyzer. The performance of the ANN was tested for a number of conditions and compared to those obtained by using deterministic models. Both ANN and deterministic models were validated experimentally. In all cases, at low biomass concentration, model predictions yielded determination coefficients greater than 0.9. Nevertheless, ANN yielded the more accurate predictions of the light pattern, at both low and high biomass concentration, when the bioreactor radius, the depth, the rotational speed of the stirrer and the biomass concentration were incorporated in the ANN structure. In comparison, most of the deterministic models failed to correlate the empirical data at high biomass concentration. These results show the usefulness of ANNs in the modeling of the light profile pattern in photobioreactors.

A Visual Warning System for the Identification of Proximity Detection Events around a Continuous Mining Machine

Underground mobile mining machines pose a difficult safety challenge since their operators generally work in close proximity to these machines in very restricted spaces. Intelligent software for use with electromagnetic proximity detection systems has been developed that can accurately locate workers around mining machinery in real time. If a worker is located too close to the machine, the machine’s operation can be partially or completely disabled to protect the workers from striking, pinning, and entanglement hazards. Researchers have developed a visual method of relaying to the operators the interdiction of their machine operations by this intelligent proximity detection system. Several lighting sequence scenarios were human subject tested for effectiveness using a computer-based multimedia platform. Analysis of the test results indicates that a “fast flash” lighting arrangement is the most effective scenario based upon subject preference, rating, and accuracy of proximity intrusion location identification. This arrangement improves reaction time by 35%.

Optical constants and spatial uniformity of thermally grown oxide layer of custom, induced-junction, silicon photodiodes for a predictable quantum efficient detector

We have investigated the optical properties of self-induced inversion-layer silicon photodiodes using spectroscopic ellipsometric measurement techniques. We report a self-consistent data set and dispersion relation for the optical constants of the thermally grown oxide layer. The oxide layer thickness and spatial uniformity of a series of custom manufactured 22 mm × 11 mm rectangular diodes are evaluated. These photodiodes are used in a light trapping arrangement and exhibit predictable quantum efficiency and thus, predictable spectral responsivity. For comparison, we report measurements of the absolute spatial uniformity of the oxide layer on commercial “S6337” and “S1337” radiometric quality photodiodes.

Embedded User Interface for LED Lighting System using LPC2148

This proposed work is to develop embedded user interface for efficient interior led lighting system which can be used to control LED down light panels, check status form the installed LED panels of interior LED lighting system in the entire building. This will be a hand held device (i.e. operates on a 5V DC power with a graphical LCD digital user interface) which can configure lighting arrangements in different places like hospitals, colleges, offices, malls, houses, etc. The only advantage of this controlling device is that it will be a single solution controlling device. This will manage the lighting needs of the entire building.

Use of image analysis tool for the development of light distribution pattern inside the photobioreactor for the algal cultivation

Light is one of the important parameters for the growth of photosynthetic microorganisms. In algal photobioreactors, pigmentation of algal cells has additional shading effect which reduces light penetration. Information on the local light intensity inside the photobioreactor is helpful for its efficient designs. Image analysis is based on trichromatic theory and it is used as a tool in studying the light distribution. Digital images of the top view of the photobioreactor were taken and processed using image processing tool in the MATLAB software. This was used to estimate the light intensity distribution in the externally radiating stirred tank photobioreactor across the radial path length. In addition, the effect of light tubes arrangement was studied. This was to find out the effect of light distribution along the periphery of culture suspension. Modified Beer-Lambert's law was found to fit the generated light intensity profile at various cell concentrations and light intensity.

High-performance LED street lighting using microlens arrays

An efficient LED lamp that illuminates the street with high quality is presented. The luminaire shows high optical efficiency, high optical utilization factor, low glare, and illuminates the street with high uniformity. The concept is simple but effective: a cluster of LEDs with TIR lenses are put inside a reflective box, which is covered with a microlens sheet; the reflective cavity improves efficiency by light recycling; each TIR lens collimates the LED light for the microlens array; and the microlens sheet uniformly distributes light only into the street. We verify its feasibility by Monte Carlo ray-tracing for the main types of road lighting arrangements: central, zigzag, and single-side pole positions.

Theoretical modeling of generation of hat-top intensity profile from Gaussian beam by means of a two-stage beam shaper

Both theoretical and experimental results of an optical beam shaping system are investigated in this report. The described system is a two-stage beam shaping device including a fiber-bundle and a prism-duct. A source light is used to illuminate the fiber-bundle and the image of output beam is captured by a CCD camera. The fiber-bundle output beam shape shows a linear arrangement of circular spots lights, which are placed in a rectangular cross section of about 21.37mm×2.44mm. In another study, the photograph picture of the prism output beam is taken by a digital camera. The prism output beam cross section is a square shape with a dimension of about 4×4mm2. According to the experimental results, the prism duct converted a Gaussian beam profile with multiple-peak distribution to a hat-top beam profile with the uniform intensity distribution. For theoretical investigations, using ZEMAX software a simulation is performed to analyze the beam shaping design. By proper modeling the output beam shape and radiance profiles in position space and angle space of the fiber-bundle and the prism duct are investigated. Theoretical radiance profiles are obtained by using simulated images and results are in agreement with the experimental results.

Recognition of Ramps and Steps by People with Low Vision

Detection and recognition of ramps and steps are important for the safe mobility of people with low vision. Our primary goal was to assess the impact of viewing conditions and environmental factors on the recognition of these targets by people with low vision. A secondary goal was to determine if results from our previous studies of normally sighted subjects, wearing acuity-reducing goggles, would generalize to low vision. Sixteen subjects with heterogeneous forms of low vision participated-acuities from approximately 20/200 to 20/2000. they viewed a sidewalk interrupted by one of five targets: a single step up or down, a ramp up or down, or a flat continuation of the sidewalk. Subjects reported which of the five targets was shown, and percent correct was computed. The effects of viewing distance, target-background contrast, lighting arrangement, and subject locomotion were investigated. Performance was compared with a group of normally sighted subjects who viewed the targets through acuity-reducing goggles. Recognition performance was significantly better at shorter distances and after locomotion (compared with purely stationary viewing). The effects of lighting arrangement and target-background contrast were weaker than hypothesized. Visibility of the targets varied, with the step up being more visible than the step down. The empirical results provide insight into factors affecting the visibility of ramps and steps for people with low vision. The effects of distance, target type, and locomotion were qualitatively similar for low vision and normal vision with artificial acuity reduction. However, the effects of lighting arrangement and background contrast were only significant for subjects with normal vision.

Development of an SSVEP-based BCI spelling system adopting a QWERTY-style LED keyboard

In this study, we introduce a new mental spelling system based on steady-state visual evoked potential (SSVEP), adopting a QWERTY style layout keyboard with 30 LEDs flickering with different frequencies. The proposed electroencephalography (EEG)-based mental spelling system allows the users to spell one target character per each target selection, without the need for multiple step selections adopted by conventional SSVEP-based mental spelling systems. Through preliminary offline experiments and online experiments, we confirmed that human SSVEPs elicited by visual flickering stimuli with a frequency resolution of 0.1Hz could be classified with classification accuracy high enough to be used for a practical brain–computer interface (BCI) system. During the preliminary offline experiments performed with five participants, we optimized various factors influencing the performance of the mental spelling system, such as distances between adjacent keys, light source arrangements, stimulating frequencies, recording electrodes, and visual angles. Additional online experiments were conducted with six participants to verify the feasibility of the optimized mental spelling system. The results of the online experiments were an average typing speed of 9.39 letters per minute (LPM) with an average success rate of 87.58%, corresponding to an average information transfer rate of 40.72 bits per minute, demonstrating the high performance of the developed mental spelling system. Indeed, the average typing speed of 9.39 LPM attained in this study was one of the best LPM results among those reported in previous BCI literatures.

Mechanical properties of polymer nanofibers revealed by interaction with streams of air

Electrospun nanofibers were captured directly between two steel rods that functioned as the “grips” of the tensile testing apparatus. Tension was applied to the selected nanofiber by displacing one of the grips at controlled rates or in steps. The stress was revealed by the deflection of a nanofiber, caused by the drag force from a broad stream of air, which flowed perpendicular to the fiber at a known velocity. The deflected position and shape of the nanofiber was observed with a light arrangement optimized to produce bright glints that were photographed with a camcorder. Image analysis of the catenary shapes of the nanofibers was combined with scanning electron microscopy measurements of the diameter of the ends of the tested fibers to evaluate the mechanical properties.Measurements of properties, including tensile strength, tensile modulus and elongation-to-break, of thin electrospun fibers were obtained on six chemically different polymers: nylon 6, poly(ethylene oxide), polyvinylpyrrolidone, poly(2-ethyl-2-oxazoline), Tecoflex® and Tecophilic® polyurethanes. To the best of our knowledge, this is the first report of tensile data on single polyvinylpyrrolidone and poly(2-ethyl-2-oxazoline) nanofibers. These soft nanofibers with low strain to break rarely survive the sample loading procedures where single fiber manipulation is involved. This method complements difficult mechanical measurements of polymer nanofibers and low strength microfibers made on miniature mechanical testing devices. Mechanical hysteresis curves were attained that show the recoverable and non-recoverable tensile deformation of PEO, nylon and Tecophilic® polyurethane fibers.

Evaluation of the Operational Parameters of Ropes

This paper discusses a visual method of measuring the geometric parameters of ropes and evaluating their wear based on measurements of a three-dimensional rope model. The 3D model is created using the method of laser triangulation. Selection of appropriate geometry of camera and laser lighting arrangement allows collection of the height profile of the observed rope surface in the selected cross-section and, subsequently, building of a 3D model. The resulting model is a representation of the actual dimensions of the rope and allows determination of the parameters describing its basic geometric dimensions and condition of rope surface. Determination of those values and parameters allows estimation of the degree of rope wear. The article discusses issues related to resolution of the vision system, resolution of laser beam analysis, and resolution relating to the measurement of the height profile on the surface of the rope. Based on the model constructed in such a way, measurements are presented in order to assess the dimensional parameters and surface defects in sample rope structures. Based on tests and analyses of the three-dimensional model, a range of inspection tasks using 3D vision systems is indicated.

Fabric in Film and Film as Fabric: Maya Deren's Meshes of the Afternoon

Maya Deren's films employ still and moving fabric in order to articulate the changing relationships among viewer, actor, and director. Deren's use of fiber-based material is an overlooked aspect of her cinematic work. In this essay I explore the parallel between the medium of film—the screen, as well as the representation of fabric on film—and fabric in several of Deren's films, primarily her well-known 1943 film Meshes of the Afternoon. This is a generative parallel because a comparison with fabric introduces the idea that film could be conceived of as, simultaneously, a tactile material and a legitimate art form to mid-century film audiences. Film's relation to the body is traditionally distanced: the audience sits far from the screen in order to view it; the actors’ bodies exist only as intangible arrangements of light and shadow. Reading film with an awareness of the characteristics and connotations of moving fabric recasts cinema in light of the screen's status as fabric, a potentially tactile medium.

Beam shape and intensity profile of a fiber-bundle prism-coupled waveguide

Design and performance of a two-stage optical beam shaping system based on a plastic fiber-bundle prism-coupled waveguide is described in this study. Such systems offer practical means to modify and change the output beam shape at two stages and also provide quantitative information concerning the output beam intensity profile. It is possible to obtain reflection and image transmittance data by using a light source for the illumination and image analysis by a CCD/digital camera. Using the active lighting, the reflection data and image profiles for the output beam are obtained by a CCD camera and presented in this study. The photograph picture of the illuminating LED beam just at its output point shows a circular shape with a radius of about 5 mm. Picture of the fiber-bundle output beam is also taken, which shows a linear arrangement of circular spot lights almost similar in cross section. The output beam cross section at this stage is in rectangular shape with a dimension of 30 mm width and 3 mm height. In another study CCD images at prism exit face is obtained and image profile is investigated. The final output beam cross section at the second stage of beam shaping is a square with a dimension of about 5 by 5 mm. The transmitted output beam power is also measured at different stages. The conversion efficiency for the fiber bundle at first stage beam shaping is about 70% and for the overall system is about 15%. In another study the relative reflected light off the prism entering face is measured by using two fiber probes in the stripe cable, which shows the ability to monitor such reflections for selecting the prism duct with a lower reflection loss.

Feasibility study of near-infrared fluorescence tomography using a positron emission tomograph equipped with depth-of-interaction PET detectors

We are currently developing an imaging system that combines simultaneous positron emission tomography (PET) with near-infrared (NIR) optical tomography, thus supporting two different types of molecular imaging. For this system, we are considering whether to use depth of interaction (DOI) PET detectors as simultaneous detectors of gamma rays and NIR light by changing the original upper reflectors to dichroic mirrors. The DOI-PET detector has very low spatial resolution for NIR light compared to the charge-coupled device cameras that are normally used. However, it is possible to reconstruct images of comparable value from the data acquired by low-resolution devices because the light is scattered by biological tissues and high-resolution devices are not necessarily effective at improving image quality. In this study, we demonstrate the feasibility of 3D NIR fluorescence tomography imaging by employing DOI-PET detectors in computer simulations. In the simulations, we used a 40 mm x 40 mm x 40 mm cubic phantom, a square detector geometry, and an optical diffusion equation to approximate the light propagation. We then evaluated imaging systems for 3D fluorescence tomography with different detector resolutions and excitation light arrangements using singular-value analysis and imaging simulation. We confirmed that the reconstructed images from low-resolution detectors (8 x 8 pixels for an area of 40 mm x 40 mm) are the same as those from high-resolution detectors (16 x 16 pixels for the same area).