1,720,955 research outputs found
COLOR PERCEPTION ESTIMATIONS OF METAMERIC PAIRS UNDER DIFFERENT ILLUMINANCE LEVELS
Get PDFLEDs or light emitting diodes of the lighting class dominate both the indoor and outdoor lighting industries today due to their accuracy and consumer-friendly color temperature. In the context of color science, it is necessary to analyze both the spectral power distribution of lighting and the human characteristics of color perception under these lights. In this article, we provide estimates of the appearance of eleven metameric pairs under LEDs with four correlated color temperatures and six illuminance levels, using color difference formulas based on the CIELAB, CAM02-UCS, and CAM16-UCS models to verify our estimates. We followed ASTM D4086 standard visual methods for detecting metamerism and for estimating the magnitude of a metameric color difference. Our investigations found that color appearance models are more reliable than CIELAB in evaluating color difference under various LED conditions. CAM16-UCS more accurately predicted the color difference estimates between all three formulas. Our comparative study confirms that the variation in the estimates with the CCT and illuminance levels of the LED sources depends on the color appearance model used. The results also showed that in order to determine the color difference of metameric pairs, optimal conditions regarding the colorimetric properties of the samples and the variability of the observer should be considered separately. We noticed an increasing correlation trend with increasing illuminance. However, there was no such increase or decrease trend in CCTs. The trend of the STRESS change in the color appearance models showed the influence of the chromatic adaptation, but the establishment of adaptation patterns is far beyond the scope of this work. Although our research has had limitations on correlated color temperature and illuminance, we believe that it can be beneficial for the lighting application to ensure correct lighting decisions when assessing the color differences of metameric pairs
A review of lcam datasets and sève whiteness proposal
No full textIn our recent work, we investigated the validity of the newly proposed whiteness formula by Robert
Sève [1] for our LCAM whiteness datasets under a LED light source of correlated color temperature
(CCT) 5000K combined with Wood's UV-A lamp.We compared the CIE whiteness formula, the Ganz
whiteness formula, and the Séve proposal to the results of visual assessment of forty white samples
assessed by ten observers with normal color vision under experimental light source. Because the Sève
proposal was derived from the CIE formula for whiteness considering whitespace, we were interested
to see its impact on our datasets under test lighting different from D65.We have found that the Sève
whiteness formula can predict maximum whiteness as a function of saturation for light conditions other
than CIE D65, but visual observations of whiteness lead to an assessment of a significant drop in
whiteness for materials with saturation between - 40 and -70 and luminance factor between 70 and 90.
As expected, both the CIE whiteness formula and the Ganz formula correlated strongly with visual
observations. In the case of the CIE equation, a high correlation coefficient of 0.84 was measured
compared to the newly proposed W2,n equation where a value of 0.71 was found. In other words, with a
very intense UV source, the intensity of which is above the UV fraction of the corresponding CIE
illuminations D, the colouration of the samples containing FWA is highly saturated. This fact is not
taken into account in the case of the CIE equation. Dr. Sève's new proposal addresses this problem, but
sufficient new visual experiments need to be set up so that the parameters of this equation can be
optimised
EFFECT OF SCOURING AND BLEACHING TREATMENT ON KNITTED COTTON FABRICS FOR ECONOMIC STUDY
Get PDFCotton is the leading fibre in Textile Industry. Cotton is still the "King" of fibers because most of the world's apparel is made of Cotton. Apart from its fairly good strength, it is considered to provide comfort due to good moisture absorption and wicking properties. It is estimated that approx. 20 million tons of Cotton is processed worldwide yearly. Unlike man made cellulosic fibers such as Rayon and Lyocell, Cotton must be properly prepared for Dyeing, printing and finishing. To prepare the cotton fabric ready for Dyeing, printing and finishing scouring & bleaching is the fundamental step. Scouring of cotton textiles is an essential treatment in textile wet processing in order to obtain a sufficiently hydrophilic fabric. During scouring, waxes and other hydrophobic materials are removed from the cotton fibers. cotton fibres are off-white in color due to having colour bodies with it and the process of destruction these colour bodies from fibres is known as bleaching. The problems involved in normal scouring & bleaching using H2O2 is requirement of higher amount of alkali that will result higher cost in Effluent Treatment Plant to remove the alkalinity, use of wetting agent, sequestering agent, detergent & stabilizer and also require acetic acid to neutral the fabric. The aim of our work is to reduce the amount of alkali that is used in scouring , no use of acetic acid after scouring for neutralization and use of single chemical in place of that is cost effective. To fulfill our aim we use Imerol Blue Liquid in place of wetting agent, sequestering agent, detergent & stabilizer that is supplied by Clairiant and compare the Imerol Blue process with classical scouring & bleaching process using stabilizer
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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