1,721,027 research outputs found
Vectorial shearing interferometer with a high resolution phase shifter
No full textVectorial shearing interferometer has been used to measure small and large non-rotationally symmetrical wavefronts aberrations. This interferometric system encompasses large and differential wavefront displacements using a high accuracy rotation system incorporated in a Mach-Zehnder interferometer. The rotation system is based on the Risley prism arrangement and it is controlled with an electronic servomotor system by means of an auto-tuning algorithm. We present the servo-mechanical system, electronic interface and algorithms to control the performance of the high resolution rotation device that is used to control the wavefront phase shifting
Pressure affects transcription profiles of Methanocaldococcus jannaschii despite the absence of barophilic growth under gas-transfer limitation
No full textWe present experimental results of monitoring pressure over samples painted with paint called Pressure Sensitive Paint (PSP), employing optical spectroscopy and imaging analysis. An electronic system to control pressure is implemented to restricted low pressure monitoring of the samples with PSP. The surface under analysis is excited with 370 nm wavelength (UV). The signal of fluorescence generated at 580 nm is correlated to variation of pressure over the interval of 4 to 200 kPa. As a complement, a set of images is acquired in the same interval of pressure. The images are processed and then lead to a set of histograms obtained from the samples images. We assess the transfer function of the system analyzing the histograms and the spectral response curves. " 2009 SPIE.",,,,,,"10.1117/12.852083",,,"http://hdl.handle.net/20.500.12104/43852","http://www.scopus.com/inward/record.url?eid=2-s2.0-73849144364&partnerID=40&md5=6a697bf17f01722ff31a01c14c270fc4",,,,,,,,"Proceedings of SPIE - The International Society for Optical Engineering",,,,"7499",,"Scopus",,,,,,"Imaging characterization; Pressure sensitive paints; Spectroscopy",,,,,,"Pressure monitoring over surfaces with sensitive paint by optical spectroscopy and intensity-based methods",,"Conference Paper"
"45615","123456789/35008",,"Galván Ramírez, M.L., Center for Tropical Disease Research, University of Guadalajara, Jalisco, México.; Sánchez Vargas, G., Center for Tropical Disease Research, University of Guadalajara, Jalisco, México.; Vielma Sandoval, M., Center for Tropical Disease Research, University of Guadalajara, Jalisco, México.; Soto Mancilla, J.L., Center for Tropical Disease Research, University of Guadalajara, Jalisco, México.",,"Galvan Ramirez, M.L
Correlation pattern recognition: Optimal parameters for quality standards control of chocolate marshmallow candy
No full textThis paper describes an in situ image recognition system designed to inspect the quality standards of the chocolate pops during their production. The essence of the recognition system is the localization of the events (i.e., defects) in the input images that affect the quality standards of pops. To this end, processing modules, based on correlation filter, and segmentation of images are employed with the objective of measuring the quality standards. Therefore, we designed the correlation filter and defined a set of features from the correlation plane. The desired values for these parameters are obtained by exploiting information about objects to be rejected in order to find the optimal discrimination capability of the system. Regarding this set of features, the pop can be correctly classified. The efficacy of the system has been tested thoroughly under laboratory conditions using at least 50 images, containing 3 different types of possible defects
Optical current sensor using phase shift algorithms
No full textA new fiber-optic current sensor (FOCS) is described which employs phase shifting algorithms to process the optical signal. In this approach the sensing element consists of a coil low birefringence fiber placed between one polarizer and four analyzers. In the Polarimeter layout, the output light from the current sensing element is divided into four beams through three nonpolarizing beamsplitters, and in each beam path is placed an analyzer and a detector. This paper discusses the characteristics of the optical current sensors, specifically for relaying applications were measurement of fault current is required. The design of the sensor, results and shift algorithms for electrical current characterization will be presented
A review on optical current transducers for power system metering
No full textCurrent and Voltage sensors have existed as a special field for more than 100 years in Power Systems. In the last two decades there has been a fast development for systems based on fiber optical technology. As consequence, groups of IEEE- PSRC, IEC TC57, CIGRE SC A3, and some others are involved in developing activities in the area of optical systems for protective relaying. This paper provides an overview on those activities discussed by international groups. The document is divided into the four major sections. The first one explains the interaction of sensors within a protection scheme. The second section deals with the designing and components of fiber-optic current sensors (FOCS). Once presented their description, there are divulged general tests identified as relevant. Finally a brief comparison with conventional sensors is presented
Reply to 'Comment on "overcoming misconceptions in quantum mechanics with the time evolution operator"'
No full textThis article presents experimental results demonstrating the performance of an erbium-doped silica fiber as a remote temperature sensor in the interval from 20C to 200C. The sensor is based on the change in the fluorescence intensity ratio of two spectral bands as a function of temperature. The green fluorescence signal was generated by up-conversion processes in the erbium-doped fiber pumped at 975 nm. A radiometric analysis was applied to the erbium-doped fiber to evaluate its performance as a temperature sensor, and the results from this analysis were compared against other rare-earth-doped fiber sensors that utilize the intensity ratio technique. Copyright " Taylor & Francis Group, LLC.",,,,,,"10.1080/01468030.2010.485293",,,"http://hdl.handle.net/20.500.12104/44183","http://www.scopus.com/inward/record.url?eid=2-s2.0-77954667413&partnerID=40&md5=7d031ef4127b38aae9e4a06ddd8e1bb6",,,,,,"4",,"Fiber and Integrated Optics",,"27
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
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