WorldWideScience

Sample records for visibility shikai kojo

  1. Development of Fresnel lens for improvement of rear visibility; Shikai kojo Fresnel lens no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Iwamoto, K; Sanada, C; Tsukino, M [Nissan Motor Co. Ltd., Tokyo (Japan)

    1997-10-01

    Fresnel lenses have been widely used to increase the visual field around vehicles for drivers. However, internal reflection in these lenses has been an obstacle in producing dear images. This internal glow is generated by incident light from an unexpected direction reflecting on the non-lens surface or radiating from the non-lens surface of the Fresnel lens. The cause of internal glow has been made dear combining louver film with the lens. The newly developed technology removes obstacles in producing dear images by reducing internal glow. 7 figs.

  2. Teaching programming to young learners using Scala and Kojo

    OpenAIRE

    Regnell, Björn; Pant, Lalit

    2014-01-01

    This paper presents an approach to teaching programming and abstract thinking to young learners using Scala and Kojo. Kojo is an open source IDE for the Scala programming language. The approach is based on Scala APIs for turtle graphics and functional pictures, a process of interactive exploration and discovery, and structured learning material that guides learners. The approach encourages playful self-learning of basic programming principles such as sequential execution, repetition, primitiv...

  3. Visibility and Haze

    Science.gov (United States)

    Haze forms when sunlight encounters particle pollution. It reduces visibility in cities and scenic areas. This web area provides regulatory information and progress towards improving visibility through EPA’s regional haze program.

  4. Visible Human Project

    Science.gov (United States)

    ... cryosections are associated with anatomical terminology. AnatLine : A prototype system consisting of an anatomical image database and ... further information is available Publications VHJOE: Visible Human Journal of Endoscopy. NLM's Current Bibliographies in Medicine, Visible ...

  5. Visibly Pushdown Automata

    DEFF Research Database (Denmark)

    Srba, Jiri

    2006-01-01

    We investigate the possibility of (bi)simulation-like preorder/equivalence checking on the class of visibly pushdown automata and its natural subclasses visibly BPA (Basic Process Algebra) and visibly one-counter automata. We describe generic methods for proving complexity upper and lower bounds...... for a number of studied preorders and equivalences like simulation, completed simulation, ready simulation, 2-nested simulation preorders/equivalences and bisimulation equivalence. Our main results are that all the mentioned equivalences and preorders are EXPTIME-complete on visibly pushdown automata, PSPACE......-complete on visibly one-counter automata and P-complete on visibly BPA. Our PSPACE lower bound for visibly one-counter automata improves also the previously known DP-hardness results for ordinary one-counter automata and one-counter nets. Finally, we study regularity checking problems for visibly pushdown automata...

  6. Visibility and Citation Impact

    Science.gov (United States)

    Ebrahim, Nader Ale; Salehi, Hadi; Embi, Mohamed Amin; Tanha, Farid Habibi; Gholizadeh, Hossein; Motahar, Seyed Mohammad

    2014-01-01

    The number of publications is the first criteria for assessing a researcher output. However, the main measurement for author productivity is the number of citations, and citations are typically related to the paper's visibility. In this paper, the relationship between article visibility and the number of citations is investigated. A case study of…

  7. Viewer Makes Radioactivity "Visible"

    Science.gov (United States)

    Yin, L. I.

    1983-01-01

    Battery operated viewer demonstrates feasibility of generating threedimensional visible light simulations of objects that emit X-ray or gamma rays. Ray paths are traced for two pinhold positions to show location of reconstructed image. Images formed by pinholes are converted to intensified visible-light images. Applications range from radioactivity contamination surveys to monitoring radioisotope absorption in tumors.

  8. Japan's healthcare policy for the elderly through the concepts of self-help (Ji-jo), mutual aid (Go-jo), social solidarity care (Kyo-jo), and governmental care (Ko-jo).

    Science.gov (United States)

    Sudo, Kyoko; Kobayashi, Jun; Noda, Shinichiro; Fukuda, Yoshiharu; Takahashi, Kenzo

    2018-03-18

    Elderly care is an emerging global issue threatening both developed and developing countries. The elderly in Japan increased to 26.7% of the population in 2015, and Japan is classified as a super-aged society. In this article, we introduce the financial aspects of the medical care and welfare services policy for the elderly in Japan. Japan's universal health insurance coverage system has been in place since 1961. Long-term care includes welfare services, which were separated from the medical care insurance scheme in 2000 when Japan was already recognized as an aging society. Since then, the percentage of the population over 65 has increased dramatically, with the productive-age population on the decrease. The Japanese government, therefore, is seeking to implement "The Community-based Integrated Care System" with the aim of building comprehensive up-to-the-end-of-life support services in each community. The system has four proposed elements: self-help (Ji-jo), mutual aid (Go-jo), social solidarity care (Kyo-jo), and government care (Ko-jo). From the financial perspective, as the government struggles against the financial burdens of an aging population, they are considering self-help and mutual aid. Based on Japan's present situation, both elements could lead to positive results. The Japanese government must also entrust the responsibility for implementing preventive support to municipalities through strongly required regional autonomy. As Japan has resolved this new challenge through several discussions over a long period of time, other aging countries could learn from the Japanese experience of solving barriers to healthcare policy for the elderly.

  9. Analyzing Visibility Configurations.

    Science.gov (United States)

    Dachsbacher, C

    2011-04-01

    Many algorithms, such as level of detail rendering and occlusion culling methods, make decisions based on the degree of visibility of an object, but do not analyze the distribution, or structure, of the visible and occluded regions across surfaces. We present an efficient method to classify different visibility configurations and show how this can be used on top of existing methods based on visibility determination. We adapt co-occurrence matrices for visibility analysis and generalize them to operate on clusters of triangular surfaces instead of pixels. We employ machine learning techniques to reliably classify the thus extracted feature vectors. Our method allows perceptually motivated level of detail methods for real-time rendering applications by detecting configurations with expected visual masking. We exemplify the versatility of our method with an analysis of area light visibility configurations in ray tracing and an area-to-area visibility analysis suitable for hierarchical radiosity refinement. Initial results demonstrate the robustness, simplicity, and performance of our method in synthetic scenes, as well as real applications.

  10. Visible spectroscopy on ASDEX

    International Nuclear Information System (INIS)

    Hofmann, J.V.

    1991-12-01

    In this report visible spectroscopy and impurity investigations on ASDEX are reviewed and several sets of visible spectra are presented. As a basis for identification of metallic impurity lines during plasma discharges spectra from a stainless steel - Cu arc have been recorded. In a next step a spectrum overview of ASDEX discharges is shown which reveals the dominating role of lines from light impurities like carbon and oxygen throughout the UV and visible range (2000 A ≤ λ ≤ 8000 A). Metallic impurity lines of neutrals or single ionized atoms are observed near localized surfaces. The dramatic effect of impurity reduction by boronization of the vessel walls is demonstrated in a few examples. In extension to some ivesti-gations already published, further diagnostic applications of visible spectroscopy are presented. Finally, the hardware and software system used on ASDEX are described in detail. (orig.)

  11. Predicting visibility of aircraft.

    Directory of Open Access Journals (Sweden)

    Andrew Watson

    Full Text Available Visual detection of aircraft by human observers is an important element of aviation safety. To assess and ensure safety, it would be useful to be able to be able to predict the visibility, to a human observer, of an aircraft of specified size, shape, distance, and coloration. Examples include assuring safe separation among aircraft and between aircraft and unmanned vehicles, design of airport control towers, and efforts to enhance or suppress the visibility of military and rescue vehicles. We have recently developed a simple metric of pattern visibility, the Spatial Standard Observer (SSO. In this report we examine whether the SSO can predict visibility of simulated aircraft images. We constructed a set of aircraft images from three-dimensional computer graphic models, and measured the luminance contrast threshold for each image from three human observers. The data were well predicted by the SSO. Finally, we show how to use the SSO to predict visibility range for aircraft of arbitrary size, shape, distance, and coloration.

  12. Measuring visibility using smartphones

    Science.gov (United States)

    Friesen, Jan; Bialon, Raphael; Claßen, Christoph; Graffi, Kalman

    2017-04-01

    Spatial information on fog density is an important parameter for ecohydrological studies in cloud forests. The Dhofar cloud forest in Southern Oman exhibits a close interaction between the fog, trees, and rainfall. During the three month monsoon season the trees capture substantial amounts of horizontal precipitation from fog which increases net precipitation below the tree canopy. As fog density measurements are scarce, a smartphone app was designed to measure visibility. Different smartphone units use a variety of different parts. It is therefore important to assess the developed visibility measurement across a suite of different smartphones. In this study we tested five smartphones/ tablets (Google/ LG Nexus 5X, Huawei P8 lite, Huawei Y3, HTC Nexus 9, and Samsung Galaxy S4 mini) against digital camera (Sony DLSR-A900) and visual visibility observations. Visibility was assessed from photos using image entropy, from the number of visible targets, and from WiFi signal strength using RSSI. Results show clear relationships between object distance and fog density, yet a considerable spread across the different smartphone/ tablet units is evident.

  13. UVISS preliminary visibility analysis

    DEFF Research Database (Denmark)

    Betto, Maurizio

    1998-01-01

    The goal of this work is to obtain a preliminary assessment of the sky visibility for anastronomical telescope located on the express pallet of the International SpaceStation (ISS)} taking into account the major constraints imposed on the instrument by the ISSattitude and structure. Part of the w......The goal of this work is to obtain a preliminary assessment of the sky visibility for anastronomical telescope located on the express pallet of the International SpaceStation (ISS)} taking into account the major constraints imposed on the instrument by the ISSattitude and structure. Part...... of the work is also to setup the kernel of a software tool for the visibility analysis thatshould be easily expandable to consider more complex strucures for future activities.This analysis is part of the UVISS assessment study and it is meant to provide elementsfor the definition and the selection...

  14. Making Invisible Forces Visible

    DEFF Research Database (Denmark)

    Ratner, Helene Gad

    2013-01-01

    This paper investigates managerial tactics of visualisation when a need to know and manage employees' values and attitudes is expressed. Using the Danish public school as a case study, we explore how school managers use teachers' emotions to render visible presumably invisible information about...... their 'true' attitudes and values. The paper draws on theories of affect as well as actor-network theory to analyse three incidents where managers turn their interpretations of teachers' emotions into such information. These incidents suggest that the efforts to render employees' attitudes and values visible...

  15. Making Invisible Histories Visible

    Science.gov (United States)

    Hanssen, Ana Maria

    2012-01-01

    This article features Omaha Public Schools' "Making Invisible Histories Visible" program, or MIHV. Omaha's schools have a low failure rate among 8th graders but a high one among high school freshmen. MIHV was created to help at-risk students "adjust to the increased demands of high school." By working alongside teachers and…

  16. Visible Solid State Lasers

    NARCIS (Netherlands)

    Hikmet, R.A.M.

    2007-01-01

    Diode lasers can be found in various applications most notably in optical communication and optical storage. Visible lasers were until recently were all based on IR diode lasers. Using GaN, directly blue and violet emitting lasers have also been introduced to the market mainly in the area of optical

  17. Social media visibility

    DEFF Research Database (Denmark)

    Uldam, Julie

    2018-01-01

    of activists remains under-researched. This article examines BP’s surveillance of activists who criticise the company’s corporate social responsibility (CSR) programme as ‘greenwashing’. In this way, it goes beyond corporations’ uses of big data and instead explores how they monitor and discuss strategies......As activists move from alternative media platforms to commercial social media platforms, they face increasing challenges in protecting their online security and privacy. While government surveillance of activists is well-documented in scholarly research and the media, corporate surveillance...... for responding to the activities of individual activists in social media. It shows that while social media afford an unprecedented level of visibility for activists, it comes with the risk of being monitored by corporations. Theoretically, it draws on conceptions of visibility in social sciences and media...

  18. Making Heat Visible

    Science.gov (United States)

    Goodhew, Julie; Pahl, Sabine; Auburn, Tim; Goodhew, Steve

    2015-01-01

    Householders play a role in energy conservation through the decisions they make about purchases and installations such as insulation, and through their habitual behavior. The present U.K. study investigated the effect of thermal imaging technology on energy conservation, by measuring the behavioral effect after householders viewed images of heat escaping from or cold air entering their homes. In Study 1 (n = 43), householders who received a thermal image reduced their energy use at a 1-year follow-up, whereas householders who received a carbon footprint audit and a non-intervention control demonstrated no change. In Study 2 (n = 87), householders were nearly 5 times more likely to install draught proofing measures after seeing a thermal image. The effect was especially pronounced for actions that addressed an issue visible in the images. Findings indicate that using thermal imaging to make heat loss visible can promote energy conservation. PMID:26635418

  19. Paradoxes of Visibility

    Directory of Open Access Journals (Sweden)

    Tarnay László

    2017-12-01

    Full Text Available The paper investigates two possible critical arguments following the pictorial turn. The first is formulated within ocularcentrism, the dominance of sight, and starts with the right to visibility as a general principle that governs today’s digital culture but gets twisted in special cases like the Auschwitz photos of the Shoa, the Abu Ghraib prison videos, or recently the website called Yolocaust. The second is conceived outside the visual culture and is meant to vindicate the other senses vis-à-vis the eyes. However, the argument is truncated here only to highlight the boomerang effect of the other senses: haptic vision. It is the case of visual perception when (a there is a lack of things to see and (b indeterminate synaesthesia: when vision intensifies the other senses in the embodied viewer. The two arguments converge upon a dialectic of the visible and the imaginable, which is formulated here as two paradoxes that the discussed examples transcend. By enforcing visibility at all costs where there is hardly anything recognizable to see, they lead to two diverging results. On the one hand, the meaning of “image” is extended toward the unimaginable, the traumatic experience, on the other hand, it is extended toward the invisible, the encounter with the radical Other.

  20. The benefits of visibility

    International Nuclear Information System (INIS)

    Krupnick, A.; DeWitt, D.

    1994-01-01

    The benefits of visibility improvement (or the damages with additional degradation) refer to increases (or decreases) in utility obtained in three different dimensions. The first of these is associated with the nature of the visibility change. Visual range may be improved so that features of an area become more distinct or the sky becomes clearer. Alternatively, normal features of an area may be marred, say by the site of a power plant or its plume (called plume blight). The second dimension is the location of the change: in an urban area, in a rural setting, or in a recreational area or area of particular beauty, such as the Grand Canyon. The third dimension is the type of value: use or non-use. Thus, a person who visits the Grand Canyon (or may visit it in the future) may hold use values for improving his view of the Canyon or its surroundings and may also old non-use values for improved visibility (whether for altruistic or other reasons) irrespective of present or planned visits. In all, therefore, there are 12 possible combinations of the elements in these three dimension, each of which is logically distinct from the others and which demands attention in the literature to derive willingness to pay (WTP)

  1. The benefits of visibility

    Energy Technology Data Exchange (ETDEWEB)

    Krupnick, A; DeWitt, D

    1994-07-01

    The benefits of visibility improvement (or the damages with additional degradation) refer to increases (or decreases) in utility obtained in three different dimensions. The first of these is associated with the nature of the visibility change. Visual range may be improved so that features of an area become more distinct or the sky becomes clearer. Alternatively, normal features of an area may be marred, say by the site of a power plant or its plume (called plume blight). The second dimension is the location of the change: in an urban area, in a rural setting, or in a recreational area or area of particular beauty, such as the Grand Canyon. The third dimension is the type of value: use or non-use. Thus, a person who visits the Grand Canyon (or may visit it in the future) may hold use values for improving his view of the Canyon or its surroundings and may also old non-use values for improved visibility (whether for altruistic or other reasons) irrespective of present or planned visits. In all, therefore, there are 12 possible combinations of the elements in these three dimension, each of which is logically distinct from the others and which demands attention in the literature to derive willingness to pay (WTP)

  2. On court interpreters' visibility

    DEFF Research Database (Denmark)

    Dubslaff, Friedel; Martinsen, Bodil

    of the service they receive. Ultimately, the findings will be used for training purposes. Future - and, for that matter, already practising - interpreters as well as the professional users of interpreters ought to take the reality of the interpreters' work in practice into account when assessing the quality...... on the interpreter's interpersonal role and, in particular, on signs of the interpreter's visibility, i.e. active co-participation. At first sight, the interpreting assignment in question seems to be a short and simple routine task which would not require the interpreter to deviate from the traditional picture...

  3. Making Invisible Forces Visible

    DEFF Research Database (Denmark)

    Ratner, Helene Gad

    2013-01-01

    their 'true' attitudes and values. The paper draws on theories of affect as well as actor-network theory to analyse three incidents where managers turn their interpretations of teachers' emotions into such information. These incidents suggest that the efforts to render employees' attitudes and values visible...... install a normative emotional scale where an ideal employee displays emotional investment and self-control. This has implications, not only for employees who are expected to exhibit the 'right' emotions, but also for management, which comes to depend on transient emotions and co-presence in situations...

  4. Visible but Unseen?

    DEFF Research Database (Denmark)

    Torkilsheyggi, Arnvør Martinsdóttir á; Hertzum, Morten

    2015-01-01

    Studies have shown that whiteboards support much cooper-ative work by for example strengthening awareness, im-proving communication, and reducing mental workload. In line with these predominantly positive findings, an emer-gency department (ED) turned to its whiteboard to improve the coordination...... of its work with blood tests. We investi-gate this use of the whiteboard through observations and informal interviews in the ED and analyze the ability of the whiteboard to support coordination and awareness in the work with blood tests. Our findings show limitations in the ability of the whiteboard...... to support awareness in a setting where the users are (locally) mobile, specifically in regard to information that requires continuous monitoring. We do however also find that the whiteboard safeguarded the work with blood tests against some risks by making blood-test information socially visible....

  5. Revisiting visibility in the plane

    DEFF Research Database (Denmark)

    Wilkinson, Bryan Thomas

    Abstract We consider two closely related problems: computing the region visible from a point amid simple polygonal obstacles and computing the lower envelope of a set of disjoint segments. Visibility problems such as these were proposed and promptly solved in the late'80s and early'90s before...

  6. On characterizing terrain visibility graphs

    Directory of Open Access Journals (Sweden)

    William Evans

    2015-06-01

    Full Text Available A terrain is an $x$-monotone polygonal line in the $xy$-plane. Two vertices of a terrain are mutually visible if and only if there is no terrain vertex on or above the open line segment connecting them. A graph whose vertices represent terrain vertices and whose edges represent mutually visible pairs of terrain vertices is called a terrain visibility graph. We would like to find properties that are both necessary and sufficient for a graph to be a terrain visibility graph; that is, we would like to characterize terrain visibility graphs.Abello et al. [Discrete and Computational Geometry, 14(3:331--358, 1995] showed that all terrain visibility graphs are “persistent”. They showed that the visibility information of a terrain point set implies some ordering requirements on the slopes of the lines connecting pairs of points in any realization, and as a step towards showing sufficiency, they proved that for any persistent graph $M$ there is a total order on the slopes of the (pseudo lines in a generalized configuration of points whose visibility graph is $M$.We give a much simpler proof of this result by establishing an orientation to every triple of vertices, reflecting some slope ordering requirements that are consistent with $M$ being the visibility graph, and prove that these requirements form a partial order. We give a faster algorithm to construct a total order on the slopes. Our approach attempts to clarify the implications of the graph theoretic properties on the ordering of the slopes, and may be interpreted as defining properties on an underlying oriented matroid that we show is a restricted type of $3$-signotope.

  7. Incremental Visualizer for Visible Objects

    DEFF Research Database (Denmark)

    Bukauskas, Linas; Bøhlen, Michael Hanspeter

    This paper discusses the integration of database back-end and visualizer front-end into a one tightly coupled system. The main aim which we achieve is to reduce the data pipeline from database to visualization by using incremental data extraction of visible objects in a fly-through scenarios. We...... also argue that passing only relevant data from the database will substantially reduce the overall load of the visualization system. We propose the system Incremental Visualizer for Visible Objects (IVVO) which considers visible objects and enables incremental visualization along the observer movement...... path. IVVO is the novel solution which allows data to be visualized and loaded on the fly from the database and which regards visibilities of objects. We run a set of experiments to convince that IVVO is feasible in terms of I/O operations and CPU load. We consider the example of data which uses...

  8. Visible neutrino decay at DUNE

    Energy Technology Data Exchange (ETDEWEB)

    Coloma, Pilar [Fermilab; Peres, Orlando G. [ICTP, Trieste

    2017-05-09

    If the heaviest neutrino mass eigenstate is unstable, its decay modes could include lighter neutrino eigenstates. In this case part of the decay products could be visible, as they would interact at neutrino detectors via mixing. At neutrino oscillation experiments, a characteristic signature of such \\emph{visible neutrino decay} would be an apparent excess of events at low energies. We focus on a simple phenomenological model in which the heaviest neutrino decays as $\

  9. Understanding and Approaching Muslim Visibilities

    DEFF Research Database (Denmark)

    Schmidt, Garbi

    2011-01-01

    Within Western nation-states such as Denmark, Islamic identities are often seen as inherently and divergently visible, an aspect that some argue is detrimental to the secular nation-state. From a research perspective, one way to nuance this position is by focusing on groups of 'invisible' Muslims...

  10. Early Learning Theories Made Visible

    Science.gov (United States)

    Beloglovsky, Miriam; Daly, Lisa

    2015-01-01

    Go beyond reading about early learning theories and see what they look like in action in modern programs and teacher practices. With classroom vignettes and colorful photographs, this book makes the works of Jean Piaget, Erik Erikson, Lev Vygotsky, Abraham Maslow, John Dewey, Howard Gardner, and Louise Derman-Sparks visible, accessible, and easier…

  11. Non-Euclidean visibility problems

    Indian Academy of Sciences (India)

    FERNANDO CHAMIZO. Departamento de Matemáticas, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain. MS received 14 November 2005. Abstract. We consider the analog of visibility problems in hyperbolic plane (repre- sented by Poincaré half-plane model H), replacing the standard lattice Z ...

  12. Are naked singularities really visible

    Energy Technology Data Exchange (ETDEWEB)

    Calvani, M [Padua Univ. (Italy). Ist. di Astronomia; De Felice, F [Alberta Univ., Edmonton (Canada); Nobili, L [Padua Univ. (Italy). Ist. di Fisica

    1978-12-09

    The question whether a Kerr naked singularity is actually visible from infinity is investigated; it is shown that in fact any signal which could be emitted from the singularity is infinitely red-shifted. This implies that naked singularities would be indistinguishable from a black hole.

  13. Visible Machine Learning for Biomedicine.

    Science.gov (United States)

    Yu, Michael K; Ma, Jianzhu; Fisher, Jasmin; Kreisberg, Jason F; Raphael, Benjamin J; Ideker, Trey

    2018-06-14

    A major ambition of artificial intelligence lies in translating patient data to successful therapies. Machine learning models face particular challenges in biomedicine, however, including handling of extreme data heterogeneity and lack of mechanistic insight into predictions. Here, we argue for "visible" approaches that guide model structure with experimental biology. Copyright © 2018. Published by Elsevier Inc.

  14. Ultraviolet, Visible, and Fluorescence Spectroscopy

    Science.gov (United States)

    Penner, Michael H.

    Spectroscopy in the ultraviolet-visible (UV-Vis) range is one of the most commonly encountered laboratory techniques in food analysis. Diverse examples, such as the quantification of macrocomponents (total carbohydrate by the phenol-sulfuric acid method), quantification of microcomponents, (thiamin by the thiochrome fluorometric procedure), estimates of rancidity (lipid oxidation status by the thiobarbituric acid test), and surveillance testing (enzyme-linked immunoassays), are presented in this text. In each of these cases, the analytical signal for which the assay is based is either the emission or absorption of radiation in the UV-Vis range. This signal may be inherent in the analyte, such as the absorbance of radiation in the visible range by pigments, or a result of a chemical reaction involving the analyte, such as the colorimetric copper-based Lowry method for the analysis of soluble protein.

  15. Chemical lasers in the visible

    International Nuclear Information System (INIS)

    Jones, C.R.; Broida, H.P.

    1974-01-01

    Since the beginning of the laser era in 1960, a continuing search for chemical lasers has been carried out. This quest has been influenced by the knowledge that many chemical reactions produce visible chemiluminescence and, therefore, partition some of the reaction products into emitting, electronically excited states. Such luminescence has been observed not only from low-pressure, gas-phase reactions, notably those of alkali metals and halogens, but also from a limited number of liquid-phase reactions. (U.S.)

  16. Computing Visible-Surface Representations,

    Science.gov (United States)

    1985-03-01

    Terzopoulos N00014-75-C-0643 9. PERFORMING ORGANIZATION NAME AMC ADDRESS 10. PROGRAM ELEMENT. PROJECT, TASK Artificial Inteligence Laboratory AREA A...Massachusetts Institute of lechnolog,. Support lbr the laboratory’s Artificial Intelligence research is provided in part by the Advanced Rtccarcl Proj...dynamically maintaining visible surface representations. Whether the intention is to model human vision or to design competent artificial vision systems

  17. [Street Outreach Offices: visibility, invisibility, and enhanced visibility].

    Science.gov (United States)

    Hallais, Janaína Alves da Silveira; Barros, Nelson Filice de

    2015-07-01

    This article discusses care for street people from a socio-anthropological perspective, using participant observation conducted with a team from a street outreach project. Based on observations, street people are historically viewed as marginal and rarely obtain access to health services, thus making them invisible to the Brazilian Unified National Health System. Brazil's National Policy for the Homeless provides for their access to health care, but such care is not always guaranteed in practice, because health services and professionals have little experience in dealing with homeless persons. The study concludes that enhanced visibility is needed to ensure care for people living on the street, establishing a therapeutic bond that deconstructs stigmatizing practice.

  18. Beyond Language Equivalence on Visibly Pushdown Automata

    DEFF Research Database (Denmark)

    Srba, Jiri

    2009-01-01

    We study (bi)simulation-like preorder/equivalence checking on the class of visibly pushdown automata and its natural subclasses visibly BPA (Basic Process Algebra) and visibly one-counter automata. We describe generic methods for proving complexity upper and lower bounds for a number of studied...... preorders and equivalences like simulation, completed simulation, ready simulation, 2-nested simulation preorders/equivalences and bisimulation equivalence. Our main results are that all the mentioned equivalences and preorders are EXPTIME-complete on visibly pushdown automata, PSPACE-complete on visibly...... one-counter automata and P-complete on visibly BPA. Our PSPACE lower bound for visibly one-counter automata improves also the previously known DP-hardness results for ordinary one-counter automata and one-counter nets. Finally, we study regularity checking problems for visibly pushdown automata...

  19. Computing visibility on terrains in external memory

    NARCIS (Netherlands)

    Haverkort, H.J.; Toma, L.; Zhuang, Yi

    2007-01-01

    We describe a novel application of the distribution sweeping technique to computing visibility on terrains. Given an arbitrary viewpoint v, the basic problem we address is computing the visibility map or viewshed of v, which is the set of points in the terrain that are visible from v. We give the

  20. Visible Nulling Coronagraph Progress Report

    Science.gov (United States)

    Lyon, R. G.; Clampin, M.; Woodruff, R. A.; Vasudevan, G.; Thompson, P.; Petrone, P.; Madison, T.; Rizzo, M.; Melnick, G.; Tolls, V.

    2010-10-01

    We report on recent laboratory results with the NASA Goddard Space Flight Center Visible Nulling Coronagraph (VNC) testbed. We have achieved focal plane contrasts of 108 and approaching 109 at inner working angles of 2 λ/D and 4 λ/D, respectively. Results were obtained with a broadband source and 40 nm filter centered on 630 nm. A null control breadboard (NCB) was also developed to assess and quantify MEMS based deformable mirror technology (DM), and to develop and assess closed-loop null control algorithms. We have demonstrated closed-loop performance at 27 Hz.

  1. Visible light broadband perfect absorbers

    Energy Technology Data Exchange (ETDEWEB)

    Jia, X. L.; Meng, Q. X.; Yuan, C. X.; Zhou, Z. X.; Wang, X. O., E-mail: wxo@hit.edu.cn [School of Science, Harbin Institute of Technology, Harbin 150001 (China)

    2016-03-15

    The visible light broadband perfect absorbers based on the silver (Ag) nano elliptical disks and holes array are studied using finite difference time domain simulations. The semiconducting indium silicon dioxide thin film is introduced as the space layer in this sandwiched structure. Utilizing the asymmetrical geometry of the structures, polarization sensitivity for transverse electric wave (TE)/transverse magnetic wave (TM) and left circular polarization wave (LCP)/right circular polarization wave (RCP) of the broadband absorption are gained. The absorbers with Ag nano disks and holes array show several peaks absorbance of 100% by numerical simulation. These simple and flexible perfect absorbers are particularly desirable for various potential applications including the solar energy absorber.

  2. Visible nulling coronagraph testbed results

    Science.gov (United States)

    Lyon, Richard G.; Clampin, Mark; Woodruff, Robert A.; Vasudevan, Gopal; Thompson, Patrick; Petrone, Peter; Madison, Timothy; Rizzo, Maxime; Melnick, Gary; Tolls, Volker

    2009-08-01

    We report on our recent laboratory results with the NASA/Goddard Space Flight Center (GSFC) Visible Nulling Coronagraph (VNC) testbed. We have experimentally achieved focal plane contrasts of 1 x 108 and approaching 109 at inner working angles of 2 * wavelength/D and 4 * wavelength/D respectively where D is the aperture diameter. The result was obtained using a broadband source with a narrowband spectral filter of width 10 nm centered on 630 nm. To date this is the deepest nulling result with a visible nulling coronagraph yet obtained. Developed also is a Null Control Breadboard (NCB) to assess and quantify MEMS based segmented deformable mirror technology and develop and assess closed-loop null sensing and control algorithm performance from both the pupil and focal planes. We have demonstrated closed-loop control at 27 Hz in the laboratory environment. Efforts are underway to first bring the contrast to > 109 necessary for the direct detection and characterization of jovian (Jupiter-like) and then to > 1010 necessary for terrestrial (Earth-like) exosolar planets. Short term advancements are expected to both broaden the spectral passband from 10 nm to 100 nm and to increase both the long-term stability to > 2 hours and the extent of the null out to a ~ 10 * wavelength / D via the use of MEMS based segmented deformable mirror technology, a coherent fiber bundle, achromatic phase shifters, all in a vacuum chamber at the GSFC VNC facility. Additionally an extreme stability textbook sized compact VNC is under development.

  3. Energy Awareness Displays - Making the Invisible Visible

    NARCIS (Netherlands)

    Börner, Dirk

    2011-01-01

    Börner, D. (2011). Energy Awareness Displays - Making the Invisible Visible. Presentation given at the Startbijeenkomst SURFnet Innovatieregeling Duurzaamheid & ICT. May, 13, 2011, Utrecht, The Netherlands.

  4. Visibility of wavelet quantization noise

    Science.gov (United States)

    Watson, A. B.; Yang, G. Y.; Solomon, J. A.; Villasenor, J.

    1997-01-01

    The discrete wavelet transform (DWT) decomposes an image into bands that vary in spatial frequency and orientation. It is widely used for image compression. Measures of the visibility of DWT quantization errors are required to achieve optimal compression. Uniform quantization of a single band of coefficients results in an artifact that we call DWT uniform quantization noise; it is the sum of a lattice of random amplitude basis functions of the corresponding DWT synthesis filter. We measured visual detection thresholds for samples of DWT uniform quantization noise in Y, Cb, and Cr color channels. The spatial frequency of a wavelet is r 2-lambda, where r is display visual resolution in pixels/degree, and lambda is the wavelet level. Thresholds increase rapidly with wavelet spatial frequency. Thresholds also increase from Y to Cr to Cb, and with orientation from lowpass to horizontal/vertical to diagonal. We construct a mathematical model for DWT noise detection thresholds that is a function of level, orientation, and display visual resolution. This allows calculation of a "perceptually lossless" quantization matrix for which all errors are in theory below the visual threshold. The model may also be used as the basis for adaptive quantization schemes.

  5. Improved visibility computation on massive grid terrains

    NARCIS (Netherlands)

    Fishman, J.; Haverkort, H.J.; Toma, L.; Wolfson, O.; Agrawal, D.; Lu, C.-T.

    2009-01-01

    This paper describes the design and engineering of algorithms for computing visibility maps on massive grid terrains. Given a terrain T, specified by the elevations of points in a regular grid, and given a viewpoint v, the visibility map or viewshed of v is the set of grid points of T that are

  6. Rendering Visible: Painting and Sexuate Subjectivity

    Science.gov (United States)

    Daley, Linda

    2015-01-01

    In this essay, I examine Luce Irigaray's aesthetic of sexual difference, which she develops by extrapolating from Paul Klee's idea that the role of painting is to render the non-visible rather than represent the visible. This idea is the premise of her analyses of phenomenology and psychoanalysis and their respective contributions to understanding…

  7. 40 CFR 52.2179 - Visibility protection.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Visibility protection. 52.2179 Section 52.2179 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) South Dakota § 52.2179 Visibility protection...

  8. 40 CFR 52.1606 - Visibility protection.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Visibility protection. 52.1606 Section 52.1606 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) New Jersey § 52.1606 Visibility protection...

  9. 40 CFR 52.1236 - Visibility protection.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Visibility protection. 52.1236 Section 52.1236 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Minnesota § 52.1236 Visibility protection. (a...

  10. 40 CFR 52.1488 - Visibility protection.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Visibility protection. 52.1488 Section 52.1488 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Nevada § 52.1488 Visibility protection. (a...

  11. 40 CFR 52.2383 - Visibility protection.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Visibility protection. 52.2383 Section 52.2383 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Vermont § 52.2383 Visibility protection. (a...

  12. 40 CFR 52.2498 - Visibility protection.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Visibility protection. 52.2498 Section 52.2498 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Washington § 52.2498 Visibility protection...

  13. 40 CFR 52.2304 - Visibility protection.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Visibility protection. 52.2304 Section 52.2304 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Texas § 52.2304 Visibility protection. (a...

  14. 40 CFR 52.1387 - Visibility protection.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Visibility protection. 52.1387 Section 52.1387 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Montana § 52.1387 Visibility protection. (a...

  15. 40 CFR 52.1831 - Visibility protection.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Visibility protection. 52.1831 Section 52.1831 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) North Dakota § 52.1831 Visibility protection...

  16. 40 CFR 52.2533 - Visibility protection.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Visibility protection. 52.2533 Section 52.2533 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) West Virginia § 52.2533 Visibility protection...

  17. 40 CFR 52.1183 - Visibility protection.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Visibility protection. 52.1183 Section 52.1183 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Michigan § 52.1183 Visibility protection. (a...

  18. 40 CFR 52.1531 - Visibility protection.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Visibility protection. 52.1531 Section 52.1531 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) New Hampshire § 52.1531 Visibility protection...

  19. 40 CFR 52.2452 - Visibility protection.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Visibility protection. 52.2452 Section 52.2452 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Virginia § 52.2452 Visibility protection. (a...

  20. 40 CFR 52.1033 - Visibility protection.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Visibility protection. 52.1033 Section 52.1033 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Maine § 52.1033 Visibility protection. (a...

  1. 40 CFR 52.1339 - Visibility protection.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Visibility protection. 52.1339 Section 52.1339 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Missouri § 52.1339 Visibility protection. (a...

  2. Query Load Balancing For Visible Object Extraction

    DEFF Research Database (Denmark)

    Bukauskas, Linas; Bøhlen, Michael Hanspeter

    2004-01-01

    Interactive visual data explorations impose rigid real-time requirements on the extraction of visible objects. Often these requirements are met by deploying powerful hardware that maintains the entire data set in huge main memory structures. In this paper we propose an approach that retrieves...... the visible data on demand and is based on a tight integration of the database and visualization systems. We propose to incrementally adjust the observer path by adding and dropping path points. The result is an optimal path that minimizes the interaction with the database system and retrieves all visible...

  3. The Disappearing Audience and Reflexive Visibility

    OpenAIRE

    Katerina Girginova

    2016-01-01

    Contrary to popular opinion and some academic writing that celebrates the renewed visibility of new media audiences, this essay argues that they are increasingly going into retreat. To understand how new media audiences “disappear” from view of one another, I borrow from Brighenti’s typology of visibility and develop the idea of “reflexive visibility.” The latter describes the ability to socially orient ourselves in a digital environment through the textual and contextual cues of others—an ac...

  4. White LED visible light communication technology research

    Science.gov (United States)

    Yang, Chao

    2017-03-01

    Visible light communication is a new type of wireless optical communication technology. White LED to the success of development, the LED lighting technology is facing a new revolution. Because the LED has high sensitivity, modulation, the advantages of good performance, large transmission power, can make it in light transmission light signal at the same time. Use white LED light-emitting characteristics, on the modulation signals to the visible light transmission, can constitute a LED visible light communication system. We built a small visible optical communication system. The system composition and structure has certain value in the field of practical application, and we also research the key technology of transmitters and receivers, the key problem has been resolved. By studying on the optical and LED the characteristics of a high speed modulation driving circuit and a high sensitive receiving circuit was designed. And information transmission through the single chip microcomputer test, a preliminary verification has realized the data transmission function.

  5. Visibility of noisy point cloud data

    KAUST Repository

    Mehra, Ravish

    2010-06-01

    We present a robust algorithm for estimating visibility from a given viewpoint for a point set containing concavities, non-uniformly spaced samples, and possibly corrupted with noise. Instead of performing an explicit surface reconstruction for the points set, visibility is computed based on a construction involving convex hull in a dual space, an idea inspired by the work of Katz et al. [26]. We derive theoretical bounds on the behavior of the method in the presence of noise and concavities, and use the derivations to develop a robust visibility estimation algorithm. In addition, computing visibility from a set of adaptively placed viewpoints allows us to generate locally consistent partial reconstructions. Using a graph based approximation algorithm we couple such reconstructions to extract globally consistent reconstructions. We test our method on a variety of 2D and 3D point sets of varying complexity and noise content. © 2010 Elsevier Ltd. All rights reserved.

  6. Mutual Visibility by Robots with Persistent Memory

    OpenAIRE

    Bhagat, Subhash; Mukhopadhyaya, Krishnendu

    2017-01-01

    This paper addresses the mutual visibility problem for a set of semi-synchronous, opaque robots occupying distinct positions in the Euclidean plane. Since robots are opaque, if three robots lie on a line, the middle robot obstructs the visions of the two other robots. The mutual visibility problem asks the robots to coordinate their movements to form a configuration, within finite time and without collision, in which no three robots are collinear. Robots are endowed with a constant bits of pe...

  7. Visible Light Communication Systems Conception and VIDAS

    OpenAIRE

    Kumar, Navin; Lourenço, Nuno; Spiez, Michal; Aguiar, Rui L

    2008-01-01

    Visible Light Communication (VLC) using LEDs is emerging as a key technology for a ubiquitous communication system, because LED has the advantages of fast switching, long life expectancy, being less expensive and being visible light that is safe for the human body. The VLC system is expected to undergo rapid progress, inspiring numerous indoor and outdoor applications; however, many technical issues need to be addressed, especially in outdoor environment. In order to provide a better understa...

  8. A climatology of visible surface reflectance spectra

    International Nuclear Information System (INIS)

    Zoogman, Peter; Liu, Xiong; Chance, Kelly; Sun, Qingsong; Schaaf, Crystal; Mahr, Tobias; Wagner, Thomas

    2016-01-01

    We present a high spectral resolution climatology of visible surface reflectance as a function of wavelength for use in satellite measurements of ozone and other atmospheric species. The Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument is planned to measure backscattered solar radiation in the 290–740 nm range, including the ultraviolet and visible Chappuis ozone bands. Observation in the weak Chappuis band takes advantage of the relative transparency of the atmosphere in the visible to achieve sensitivity to near-surface ozone. However, due to the weakness of the ozone absorption features this measurement is more sensitive to errors in visible surface reflectance, which is highly variable. We utilize reflectance measurements of individual plant, man-made, and other surface types to calculate the primary modes of variability of visible surface reflectance at a high spectral resolution, comparable to that of TEMPO (0.6 nm). Using the Moderate-resolution Imaging Spectroradiometer (MODIS) Bidirection Reflectance Distribution Function (BRDF)/albedo product and our derived primary modes we construct a high spatial resolution climatology of wavelength-dependent surface reflectance over all viewing scenes and geometries. The Global Ozone Monitoring Experiment–2 (GOME-2) Lambertian Equivalent Reflectance (LER) product provides complementary information over water and snow scenes. Preliminary results using this approach in multispectral ultraviolet+visible ozone retrievals from the GOME-2 instrument show significant improvement to the fitting residuals over vegetated scenes. - Highlights: • Our goals was visible surface reflectance for satellite trace gas measurements. • Captured the range of surface reflectance spectra through EOF analysis. • Used satellite surface reflectance products for each given scene to anchor EOFs. • Generated a climatology of time/geometry dependent surface reflectance spectra. • Demonstrated potential to

  9. [VISIBLE LIGHT AND HUMAN SKIN (REVIEW)].

    Science.gov (United States)

    Tsibadze, A; Chikvaidze, E; Katsitadze, A; Kvachadze, I; Tskhvediani, N; Chikviladze, A

    2015-09-01

    Biological effect of a visible light depends on extend of its property to penetrate into the tissues: the greater is a wavelength the more is an effect of a radiation. An impact of a visible light on the skin is evident by wave and quantum effects. Quanta of a visible radiation carry more energy than infrared radiation, although an influence of such radiation on the skin is produced by the light spectrum on the boarder of the ultraviolet and the infrared rays and is manifested by thermal and chemical effects. It is determined that large doses of a visible light (405-436 nm) can cause skin erythema. At this time, the ratio of generation of free radicals in the skin during an exposure to the ultraviolet and the visible light range from 67-33% respectively. Visible rays of 400-500 nm length of wave cause an increase of the concentration of oxygen's active form and mutation of DNA and proteins in the skin. The urticaria in 4-18% of young people induced by photodermatosis is described. As a result of a direct exposure to sunlight photosensitive eczema is more common in elderly. Special place holds a hereditary disease - porphyria, caused by a visible light. In recent years, dermatologists widely use phototherapy. The method uses polychromatic, non-coherent (wavelength of 515-1200 nm) pulsating beam. During phototherapy/light treatment a patient is being exposed to sunlight or bright artificial light. Sources of visible light are lasers, LEDs and fluorescent lamps which have the full range of a visible light. Phototherapy is used in the treatment of acne vulgaris, seasonal affective disorders, depression, psoriasis, eczema and neurodermities. LED of the red and near infrared range also is characterized by the therapeutic effect. They have an ability to influence cromatophores and enhance ATP synthesis in mitochondria. To speed up the healing of wounds and stimulate hair growth light sources of a weak intensity are used. The light of blue-green spectrum is widely used for

  10. Psychophysical thresholds of face visibility during infancy

    DEFF Research Database (Denmark)

    Gelskov, Sofie; Kouider, Sid

    2010-01-01

    The ability to detect and focus on faces is a fundamental prerequisite for developing social skills. But how well can infants detect faces? Here, we address this question by studying the minimum duration at which faces must appear to trigger a behavioral response in infants. We used a preferential...... looking method in conjunction with masking and brief presentations (300 ms and below) to establish the temporal thresholds of visibility at different stages of development. We found that 5 and 10 month-old infants have remarkably similar visibility thresholds about three times higher than those of adults....... By contrast, 15 month-olds not only revealed adult-like thresholds, but also improved their performance through memory-based strategies. Our results imply that the development of face visibility follows a non-linear course and is determined by a radical improvement occurring between 10 and 15 months....

  11. Visibility graph approach to exchange rate series

    Science.gov (United States)

    Yang, Yue; Wang, Jianbo; Yang, Huijie; Mang, Jingshi

    2009-10-01

    By means of a visibility graph, we investigate six important exchange rate series. It is found that the series convert into scale-free and hierarchically structured networks. The relationship between the scaling exponents of the degree distributions and the Hurst exponents obeys the analytical prediction for fractal Brownian motions. The visibility graph can be used to obtain reliable values of Hurst exponents of the series. The characteristics are explained by using the multifractal structures of the series. The exchange rate of EURO to Japanese Yen is widely used to evaluate risk and to estimate trends in speculative investments. Interestingly, the hierarchies of the visibility graphs for the exchange rate series of these two currencies are significantly weak compared with that of the other series.

  12. Digital/Commercial (In)visibility

    DEFF Research Database (Denmark)

    Leander, Anna

    2017-01-01

    an argument demonstrating specifically how digital and commercial logics characterize the aesthetic, circulatory, and infrastructuring practices re-producing the regime of (in)visibility. It shows that digital/commercial logics are at the heart of the combinatorial marketing of multiple, contradictory images......This article explores one aspect of digital politics, the politics of videos and more spe- cifically of DAESH recruitment videos. It proposes a practice theoretical approach to the politics of DAESH recruitment videos focused on the re-production of regimes of (in)visibility. The article develops...... on the internet. The theoretical and political cost of overlooking these digital and commercial characteristics of DAESH visibility practices are high. It perpetuates misconceptions of how the videos work and what their politics are and it reinforces the digital Orientalism/Occidentalism in which...

  13. The Disappearing Audience and Reflexive Visibility

    Directory of Open Access Journals (Sweden)

    Katerina Girginova

    2016-08-01

    Full Text Available Contrary to popular opinion and some academic writing that celebrates the renewed visibility of new media audiences, this essay argues that they are increasingly going into retreat. To understand how new media audiences “disappear” from view of one another, I borrow from Brighenti’s typology of visibility and develop the idea of “reflexive visibility.” The latter describes the ability to socially orient ourselves in a digital environment through the textual and contextual cues of others—an activity that is of utmost importance not only to researchers wishing to “see” various audiences but also for audiences writ large, wishing to know themselves.

  14. Visible imaging of edge turbulence in NSTX

    International Nuclear Information System (INIS)

    Zweben, S.; Maqueda, R.; Hill, K.; Johnson, D.

    2000-01-01

    Edge plasma turbulence in tokamaks and stellarators is believed to cause the radical heat and particle flux across the separatrix and into the scrape-off-layers of these devices. This paper describes initial measurements of 2-D space-time structure of the edge density turbulence made using a visible imaging diagnostic in the National Spherical Torus Experiment (NSTX). The structure of the edge turbulence is most clearly visible using a method of gas puff imaging to locally illuminate the edge density turbulence

  15. Visible imaging of edge turbulence in NSTX

    International Nuclear Information System (INIS)

    S. Zweben; R. Maqueda; K. Hill; D. Johnson; S. Kaye; H. Kugel; F. Levinton; R. Maingi; L. Roquemore; S. Sabbagh; G. Wurden

    2000-01-01

    Edge plasma turbulence in tokamaks and stellarators is believed to cause the radial heat and particle flux across the separatrix and into the scrape-off-layers of these devices. This paper describes initial measurements of 2-D space-time structure of the edge density turbulence made using a visible imaging diagnostic in the National Spherical Torus Experiment (NSTX). The structure of the edge turbulence is most clearly visible using a method of ''gas puff imaging'' to locally illuminate the edge density turbulence

  16. 60 years of UK visibility measurements: impact of meteorology and atmospheric pollutants on visibility

    Science.gov (United States)

    Singh, Ajit; Bloss, William J.; Pope, Francis D.

    2017-02-01

    Reduced visibility is an indicator of poor air quality. Moreover, degradation in visibility can be hazardous to human safety; for example, low visibility can lead to road, rail, sea and air accidents. In this paper, we explore the combined influence of atmospheric aerosol particle and gas characteristics, and meteorology, on long-term visibility. We use visibility data from eight meteorological stations, situated in the UK, which have been running since the 1950s. The site locations include urban, rural and marine environments. Most stations show a long-term trend of increasing visibility, which is indicative of reductions in air pollution, especially in urban areas. Additionally, the visibility at all sites shows a very clear dependence on relative humidity, indicating the importance of aerosol hygroscopicity on the ability of aerosol particles to scatter radiation. The dependence of visibility on other meteorological parameters, such as wind speed and wind direction, is also investigated. Most stations show long-term increases in temperature which can be ascribed to climate change, land-use changes (e.g. urban heat island effects) or a combination of both; the observed effect is greatest in urban areas. The impact of this temperature change upon local relative humidity is discussed. To explain the long-term visibility trends and their dependence on meteorological conditions, the measured data were fitted to a newly developed light-extinction model to generate predictions of historic aerosol and gas scattering and absorbing properties. In general, an excellent fit was achieved between measured and modelled visibility for all eight sites. The model incorporates parameterizations of aerosol hygroscopicity, particle concentration, particle scattering, and particle and gas absorption. This new model should be applicable and is easily transferrable to other data sets worldwide. Hence, historical visibility data can be used to assess trends in aerosol particle

  17. Making Intercultural Language Learning Visible and Assessable

    Science.gov (United States)

    Moloney, Robyn; Harbon, Lesley

    2010-01-01

    While languages education (Liddicoat, 2002) is being transformed by intercultural language learning theory, there is little illustration of either how students are achieving intercultural learning or how to assess it. This article reports on a study of high school language students in Sydney, Australia. Its findings make visible student…

  18. The Visible Hand of Research Performance Assessment

    Science.gov (United States)

    Hamann, Julian

    2016-01-01

    Far from allowing a governance of universities by the invisible hand of market forces, research performance assessments do not just measure differences in research quality, but yield themselves visible symptoms in terms of a stratification and standardization of disciplines. The article illustrates this with a case study of UK history departments…

  19. Visibility of noisy point cloud data

    KAUST Repository

    Mehra, Ravish; Tripathi, Pushkar; Sheffer, Alla; Mitra, Niloy J.

    2010-01-01

    for the points set, visibility is computed based on a construction involving convex hull in a dual space, an idea inspired by the work of Katz et al. [26]. We derive theoretical bounds on the behavior of the method in the presence of noise and concavities

  20. Visible light reduces C. elegans longevity.

    Science.gov (United States)

    De Magalhaes Filho, C Daniel; Henriquez, Brian; Seah, Nicole E; Evans, Ronald M; Lapierre, Louis R; Dillin, Andrew

    2018-03-02

    The transparent nematode Caenorhabditis elegans can sense UV and blue-violet light to alter behavior. Because high-dose UV and blue-violet light are not a common feature outside of the laboratory setting, we asked what role, if any, could low-intensity visible light play in C. elegans physiology and longevity. Here, we show that C. elegans lifespan is inversely correlated to the time worms were exposed to visible light. While circadian control, lite-1 and tax-2 do not contribute to the lifespan reduction, we demonstrate that visible light creates photooxidative stress along with a general unfolded-protein response that decreases the lifespan. Finally, we find that long-lived mutants are more resistant to light stress, as well as wild-type worms supplemented pharmacologically with antioxidants. This study reveals that transparent nematodes are sensitive to visible light radiation and highlights the need to standardize methods for controlling the unrecognized biased effect of light during lifespan studies in laboratory conditions.

  1. A feeling of being (in)visible

    DEFF Research Database (Denmark)

    Damsgaard, Janne Brammer; Bastrup, Lene; Norlyk, Annelise

    Abstract PhD Day 2015 The illness trajectory of spine fusion patients. A feeling of being (in)visible Background Research shows that being a back patient is associated with great personal cost, and that back patients who undergo so-called spine fusion often experience particularly long...

  2. Digital Vigilantism as Weaponisation of Visibility

    NARCIS (Netherlands)

    D. Trottier (Daniel)

    2017-01-01

    textabstractThis paper considers an emerging practice whereby citizen’s use of ubiquitous and domesticated technologies enable a parallel form of criminal justice. Here, weaponised visibility supersedes police intervention as an appropriate response. Digital vigilantism is a user-led violation of

  3. 40 CFR 52.2781 - Visibility protection.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Visibility protection. 52.2781 Section 52.2781 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED... protection. (a) The requirements of section 169A of the Clean Air Act are not met, because the plan does not...

  4. 40 CFR 52.2132 - Visibility protection.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Visibility protection. 52.2132 Section 52.2132 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED... protection. (a) The requirements of section 169A of the Clean Air Act are not met, because the plan does not...

  5. Visible Counterterrorism Measures in Urban Spaces

    DEFF Research Database (Denmark)

    Dalgaard-Nielsen, Anja; Laisen, Jesper; Wandorf, Charlotte

    2014-01-01

    factors impacting positively or negatively on the feelings of safety of Danish citizens, when being in a crowded place. Surprisingly, the response to security measures like fences, cameras, and uniformed guards was positive. More visible security apparently reinforced feelings of safety. This article...

  6. Efficient Geometric Sound Propagation Using Visibility Culling

    Science.gov (United States)

    Chandak, Anish

    2011-07-01

    Simulating propagation of sound can improve the sense of realism in interactive applications such as video games and can lead to better designs in engineering applications such as architectural acoustics. In this thesis, we present geometric sound propagation techniques which are faster than prior methods and map well to upcoming parallel multi-core CPUs. We model specular reflections by using the image-source method and model finite-edge diffraction by using the well-known Biot-Tolstoy-Medwin (BTM) model. We accelerate the computation of specular reflections by applying novel visibility algorithms, FastV and AD-Frustum, which compute visibility from a point. We accelerate finite-edge diffraction modeling by applying a novel visibility algorithm which computes visibility from a region. Our visibility algorithms are based on frustum tracing and exploit recent advances in fast ray-hierarchy intersections, data-parallel computations, and scalable, multi-core algorithms. The AD-Frustum algorithm adapts its computation to the scene complexity and allows small errors in computing specular reflection paths for higher computational efficiency. FastV and our visibility algorithm from a region are general, object-space, conservative visibility algorithms that together significantly reduce the number of image sources compared to other techniques while preserving the same accuracy. Our geometric propagation algorithms are an order of magnitude faster than prior approaches for modeling specular reflections and two to ten times faster for modeling finite-edge diffraction. Our algorithms are interactive, scale almost linearly on multi-core CPUs, and can handle large, complex, and dynamic scenes. We also compare the accuracy of our sound propagation algorithms with other methods. Once sound propagation is performed, it is desirable to listen to the propagated sound in interactive and engineering applications. We can generate smooth, artifact-free output audio signals by applying

  7. Predicting catastrophes of non-autonomous networks with visibility graphs and horizontal visibility

    Science.gov (United States)

    Zhang, Haicheng; Xu, Daolin; Wu, Yousheng

    2018-05-01

    Prediction of potential catastrophes in engineering systems is a challenging problem. We first attempt to construct a complex network to predict catastrophes of a multi-modular floating system in advance of their occurrences. Response time series of the system can be mapped into an virtual network by using visibility graph or horizontal visibility algorithm. The topology characteristics of the networks can be used to forecast catastrophes of the system. Numerical results show that there is an obvious corresponding relationship between the variation of topology characteristics and the onset of catastrophes. A Catastrophe Index (CI) is proposed as a numerical indicator to measure a qualitative change from a stable state to a catastrophic state. The two approaches, the visibility graph and horizontal visibility algorithms, are compared by using the index in the reliability analysis with different data lengths and sampling frequencies. The technique of virtual network method is potentially extendable to catastrophe predictions of other engineering systems.

  8. Design for The Indoor Visible Light Communication Application System Based on LED Visible Light

    Directory of Open Access Journals (Sweden)

    Lian Wenyu

    2017-01-01

    Full Text Available This paper designs an indoor visible light communication application system based on LED. The system can modulate the original signal one or more times, move to a specific frequency band, transmit on the power line, in the LED terminal use this module to decode, restore the Ethernet signals. This design is applicable to the simplicity of the LED visible light communication applications, which provide the premise and guarantee for the construction of smart home network.

  9. Application of visible spectroscopy in waste sorting

    Science.gov (United States)

    Spiga, Philippe; Bourely, Antoine

    2011-10-01

    Today, waste recycling, (bottles, papers...), is a mechanical operation: the waste are crushed, fused and agglomerated in order to obtain new manufactured products (e.g. new bottles, clothes ...). The plastics recycling is the main application in the color sorting process. The colorless plastics recovered are more valuable than the colored plastics. Other emergent applications are in the paper sorting, where the main goal is to sort dyed paper from white papers. Up to now, Pellenc Selective Technologies has manufactured color sorting machines based on RGB cameras. Three dimensions (red, green and blue) are no longer sufficient to detect low quantities of dye in the considered waste. In order to increase the efficiency of the color detection, a new sorting machine, based on visible spectroscopy, has been developed. This paper presents the principles of the two approaches and their difference in terms of sorting performance, making visible spectroscopy a clear winner.

  10. Visibility graphlet approach to chaotic time series

    Energy Technology Data Exchange (ETDEWEB)

    Mutua, Stephen [Business School, University of Shanghai for Science and Technology, Shanghai 200093 (China); Computer Science Department, Masinde Muliro University of Science and Technology, P.O. Box 190-50100, Kakamega (Kenya); Gu, Changgui, E-mail: gu-changgui@163.com, E-mail: hjyang@ustc.edu.cn; Yang, Huijie, E-mail: gu-changgui@163.com, E-mail: hjyang@ustc.edu.cn [Business School, University of Shanghai for Science and Technology, Shanghai 200093 (China)

    2016-05-15

    Many novel methods have been proposed for mapping time series into complex networks. Although some dynamical behaviors can be effectively captured by existing approaches, the preservation and tracking of the temporal behaviors of a chaotic system remains an open problem. In this work, we extended the visibility graphlet approach to investigate both discrete and continuous chaotic time series. We applied visibility graphlets to capture the reconstructed local states, so that each is treated as a node and tracked downstream to create a temporal chain link. Our empirical findings show that the approach accurately captures the dynamical properties of chaotic systems. Networks constructed from periodic dynamic phases all converge to regular networks and to unique network structures for each model in the chaotic zones. Furthermore, our results show that the characterization of chaotic and non-chaotic zones in the Lorenz system corresponds to the maximal Lyapunov exponent, thus providing a simple and straightforward way to analyze chaotic systems.

  11. Visible light communications modulation and signal processing

    CERN Document Server

    Wang, Zhaocheng; Huang, Wei; Xu, Zhengyuan

    2018-01-01

    This informative new book on state-of-the-art visible light communication (VLC) provides, for the first time, a systematical and advanced treatment of modulation and signal processing for VLC. Visible Light Communications: Modulation and Signal Processing offers a practical guide to designing VLC, linking academic research with commercial applications. In recent years, VLC has attracted attention from academia and industry since it has many advantages over the traditional radio frequency, including wide unregulated bandwidth, high security, and low cost. It is a promising complementary technique in 5G and beyond wireless communications, especially in indoor applications. However, lighting constraints have not been fully considered in the open literature when considering VLC system design, and its importance has been underestimated. That’s why this book—written by a team of experts with both academic research experience and industrial development experience in the field—is so welcome. To help readers u...

  12. Advances and prospects in visible light communications

    International Nuclear Information System (INIS)

    Chen Hongda; Wu Chunhui; Li Honglei; Chen Xiongbin; Gao Zongyu; Cui Shigang; Wang Qin

    2016-01-01

    Visible light communication (VLC) is an emerging technology in optical wireless communication (OWC) that has attracted worldwide research in recent years. VLC can combine communication and illumination together, which could be applied in many application scenarios such as visible light communication local area networks (VLANs), indoor localization, and intelligent lighting. In recent years, pioneering and significant work have been made in the field of VLC. In this paper, an overview of the recent progress in VLC is presented. We also demonstrate our recent experiment results including bidirectional 100 Mbit/s VLAN or Li-Fi system based on OOK modulation without blue filter. The VLC systems that we proposed are good solutions for high-speed VLC application systems with low-cost and low-complexity. VLC technology shows a bright future due to its inherent advantages, shortage of RF spectra and ever increasing popularity of white LEDs. (review)

  13. Combined eye-atmosphere visibility model

    Science.gov (United States)

    Kaufman, Y. J.

    1981-01-01

    Existing models of the optical characteristics of the eye are combined with a recent model of optical characteristics of the atmosphere given by its modulation transfer function. This combination results in the combined eye-atmosphere performance given by the product of their modulation transfer functions. An application for the calculation of visibility thresholds in the case of a two-halves field is given.

  14. The visible Smith-Purcell radiation search

    International Nuclear Information System (INIS)

    Fernow, R.C.; Kirk, H.G.; Ulc, S. Wang, X.

    1994-03-01

    We report here the results of an experiment at the Accelerator Test Facility at Brookhaven National Laboratory to search for the production of visible radiation from the Smith-Purcell effect using a 3 MeV electron beam. After running the experiment under a variety of conditions we were unable to isolate a definite signal from Smith-Parcell effect. Any Smith-Purcell signal present in the measured radiation was less than 10% of the background signal

  15. Mirage: a visible signature evaluation tool

    Science.gov (United States)

    Culpepper, Joanne B.; Meehan, Alaster J.; Shao, Q. T.; Richards, Noel

    2017-10-01

    This paper presents the Mirage visible signature evaluation tool, designed to provide a visible signature evaluation capability that will appropriately reflect the effect of scene content on the detectability of targets, providing a capability to assess visible signatures in the context of the environment. Mirage is based on a parametric evaluation of input images, assessing the value of a range of image metrics and combining them using the boosted decision tree machine learning method to produce target detectability estimates. It has been developed using experimental data from photosimulation experiments, where human observers search for vehicle targets in a variety of digital images. The images used for tool development are synthetic (computer generated) images, showing vehicles in many different scenes and exhibiting a wide variation in scene content. A preliminary validation has been performed using k-fold cross validation, where 90% of the image data set was used for training and 10% of the image data set was used for testing. The results of the k-fold validation from 200 independent tests show a prediction accuracy between Mirage predictions of detection probability and observed probability of detection of r(262) = 0:63, p Pearson correlation) and a MAE = 0:21 (mean absolute error).

  16. Photodetector Characteristics in Visible Light Communication

    KAUST Repository

    Ho, Kang-Ting

    2016-04-01

    Typically, in the semiconductor industry pn heterojunctions have been used as either light-emitting diodes (LED) or photodiodes by applying forward current bias or reverse voltage bias, respectively. However, since both devices use the same structure, the light emitting and detecting properties could be combine in one single device, namely LED-based photodetector. Therefore, by integrating LED-based photodetectors as either transmitter or receiver, optical wireless communication could be easily implemented for bidirectional visible light communication networks at low-cost. Therefore, this dissertation focus on the investigation of the photodetection characteristics of InGaN LED-based photodetectors for visible light communication in the blue region. In this regard, we obtain external quantum efficiency of 10 % and photoresponse rise time of 71 μs at 405-nm illumination, revealing high-performance photodetection characteristics. Furthermore, we use orthogonal frequency division multiplexing quadrature amplitude modulation codification scheme to enlarge the operational bandwidth. Consequently, the transmission rate of the communication is efficiently enhanced up to 420 Mbit/s in visible light communication.

  17. Visible Light Responsive Catalyst for Air Water Purification Project

    Science.gov (United States)

    Wheeler, Raymond M.

    2014-01-01

    Investigate and develop viable approaches to render the normally UV-activated TIO2 catalyst visible light responsive (VLR) and achieve high and sustaining catalytic activity under the visible region of the solar spectrum.

  18. Efficient visibility-driven medical image visualisation via adaptive binned visibility histogram.

    Science.gov (United States)

    Jung, Younhyun; Kim, Jinman; Kumar, Ashnil; Feng, David Dagan; Fulham, Michael

    2016-07-01

    'Visibility' is a fundamental optical property that represents the observable, by users, proportion of the voxels in a volume during interactive volume rendering. The manipulation of this 'visibility' improves the volume rendering processes; for instance by ensuring the visibility of regions of interest (ROIs) or by guiding the identification of an optimal rendering view-point. The construction of visibility histograms (VHs), which represent the distribution of all the visibility of all voxels in the rendered volume, enables users to explore the volume with real-time feedback about occlusion patterns among spatially related structures during volume rendering manipulations. Volume rendered medical images have been a primary beneficiary of VH given the need to ensure that specific ROIs are visible relative to the surrounding structures, e.g. the visualisation of tumours that may otherwise be occluded by neighbouring structures. VH construction and its subsequent manipulations, however, are computationally expensive due to the histogram binning of the visibilities. This limits the real-time application of VH to medical images that have large intensity ranges and volume dimensions and require a large number of histogram bins. In this study, we introduce an efficient adaptive binned visibility histogram (AB-VH) in which a smaller number of histogram bins are used to represent the visibility distribution of the full VH. We adaptively bin medical images by using a cluster analysis algorithm that groups the voxels according to their intensity similarities into a smaller subset of bins while preserving the distribution of the intensity range of the original images. We increase efficiency by exploiting the parallel computation and multiple render targets (MRT) extension of the modern graphical processing units (GPUs) and this enables efficient computation of the histogram. We show the application of our method to single-modality computed tomography (CT), magnetic resonance

  19. 40 CFR 49.124 - Rule for limiting visible emissions.

    Science.gov (United States)

    2010-07-01

    ...% opacity limit. (3) The visible emissions from an oil-fired boiler or solid fuel-fired boiler that... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Rule for limiting visible emissions. 49... Application to Indian Reservations in Epa Region 10 § 49.124 Rule for limiting visible emissions. (a) What is...

  20. Use of cameras for monitoring visibility impairment

    Science.gov (United States)

    Malm, William; Cismoski, Scott; Prenni, Anthony; Peters, Melanie

    2018-02-01

    Webcams and automated, color photography cameras have been routinely operated in many U.S. national parks and other federal lands as far back as 1988, with a general goal of meeting interpretive needs within the public lands system and communicating effects of haze on scenic vistas to the general public, policy makers, and scientists. Additionally, it would be desirable to extract quantifiable information from these images to document how visibility conditions change over time and space and to further reflect the effects of haze on a scene, in the form of atmospheric extinction, independent of changing lighting conditions due to time of day, year, or cloud cover. Many studies have demonstrated a link between image indexes and visual range or extinction in urban settings where visibility is significantly degraded and where scenes tend to be gray and devoid of color. In relatively clean, clear atmospheric conditions, clouds and lighting conditions can sometimes affect the image radiance field as much or more than the effects of haze. In addition, over the course of many years, cameras have been replaced many times as technology improved or older systems wore out, and therefore camera image pixel density has changed dramatically. It is shown that gradient operators are very sensitive to image resolution while contrast indexes are not. Furthermore, temporal averaging and time of day restrictions allow for developing quantitative relationships between atmospheric extinction and contrast-type indexes even when image resolution has varied over time. Temporal averaging effectively removes the variability of visibility indexes associated with changing cloud cover and weather conditions, and changes in lighting conditions resulting from sun angle effects are best compensated for by restricting averaging to only certain times of the day.

  1. New stratospheric UV/visible radiance measurements

    Directory of Open Access Journals (Sweden)

    F. J. Marceau

    1994-01-01

    Full Text Available A stratospheric balloon was launched on 12 October 1986 from the "CNES" base at Aire sur l'Adour (France to record twilight radiance in the stratosphere. The near-UV and visible radiances were continuously monitored by a photometer during sunrise. Some observations are presented for different viewing azimuthal planes and viewing elevation angles. They show the influence of aerosols layers and clouds which can be also seen on related photographs. The results as a whole may be used for testing some radiative models, especially for twilight conditions.

  2. Visibly ethnically different families in Denmark & Sweden

    DEFF Research Database (Denmark)

    Singla, Rashmi

    to the dominant colorblindness discourse, while later comprise a heated topic challenging poor (global south) adoptee meeting a loving Danish family’ discourse. How do these family members narrate their experiences of societal encounter is the research question, which is answered through two qualitative interview....... Alongside colorblindness, limited/ missing racialisation discussions, the visible bodies of spouses, children in the mixed families and the transnational adoptees are made salient in their everyday lives in interactions with the white majority population through experiences as gaze, curious questions...

  3. Daily visibility and mortality: assessment of health benefits from improved visibility in Hong Kong.

    Science.gov (United States)

    Thach, Thuan-Quoc; Wong, Chit-Ming; Chan, King-Pan; Chau, Yuen-Kwan; Chung, Yat-Nork; Ou, Chun-Quan; Yang, Lin; Hedley, Anthony J

    2010-08-01

    Visibility in Hong Kong has deteriorated significantly over 40 years with visibility below 8km in the absence of fog, mist, or precipitation, increasing from 6.6 days in 1968 to 54.1 days in 2007. We assessed the short-term mortality effects of daily loss of visibility. During 1996-2006, we obtained mortality data for non-accidental and cardiorespiratory causes, visibility recorded as visual range in kilometers, temperature, and relative humidity from an urban observatory, and concentrations of four criteria pollutants. A generalized additive Poisson regression model with penalized cubic regression splines was fitted to control for time variant covariates. For non-accidental mortality, an interquartile range (IQR) of 6.5km decrease in visibility at lag0-1 days was associated with an excess risk (ER%) [95% CI] of 1.13 [0.49, 1.76] for all ages and 1.37 [0.65, 2.09] for ages 65 years and over; for cardiovascular mortality of 1.31 [0.13, 2.49] for all ages, and 1.72 [0.44, 3.00] for ages 65 years and over; and for respiratory mortality of 1.92 [0.49, 3.35] for all ages and 1.76 [0.28, 3.25] for ages 65 years and over. The estimated ER% for daily mortality derived from both visibility and air pollutant data were comparable in terms of magnitude, lag pattern, and exposure-response relationships especially when using particulate matter with aerodynamic diameter health risks from ambient air pollutants and a valid approach for the assessment of the public health impacts of air pollution and the benefits of air quality improvement measures in developing countries where pollutant monitoring data are scarce. Copyright 2010 Elsevier Inc. All rights reserved.

  4. UV/Visible Telescope with Hubble Disposal

    Science.gov (United States)

    Benford, Dominic J.

    2013-01-01

    Submission Overview: Our primary objective is to convey a sense of the significant advances possible in astrophysics investigations for major Cosmic Origins COR program goals with a 2.4m telescope asset outfitted with one or more advanced UV visible instruments. Several compelling science objectives were identified based on community meetings these science objectives drove the conceptual design of instruments studied by the COR Program Office during July September 2012. This RFI submission encapsulates the results of that study, and suggests that a more detailed look into the instrument suite should be conducted to prove viability and affordability to support the demonstrated scientific value. This study was conducted in the context of a larger effort to consider the options available for a mission to dispose safely of Hubble hence, the overall architecture considered for the mission we studied for the 2.4m telescope asset included resource sharing. This mitigates combined cost and risk and provides naturally for a continued US leadership role in astrophysics with an advanced, general-purpose UV visible space telescope.

  5. Visibility Graph Based Time Series Analysis.

    Science.gov (United States)

    Stephen, Mutua; Gu, Changgui; Yang, Huijie

    2015-01-01

    Network based time series analysis has made considerable achievements in the recent years. By mapping mono/multivariate time series into networks, one can investigate both it's microscopic and macroscopic behaviors. However, most proposed approaches lead to the construction of static networks consequently providing limited information on evolutionary behaviors. In the present paper we propose a method called visibility graph based time series analysis, in which series segments are mapped to visibility graphs as being descriptions of the corresponding states and the successively occurring states are linked. This procedure converts a time series to a temporal network and at the same time a network of networks. Findings from empirical records for stock markets in USA (S&P500 and Nasdaq) and artificial series generated by means of fractional Gaussian motions show that the method can provide us rich information benefiting short-term and long-term predictions. Theoretically, we propose a method to investigate time series from the viewpoint of network of networks.

  6. Visibility Graph Based Time Series Analysis.

    Directory of Open Access Journals (Sweden)

    Mutua Stephen

    Full Text Available Network based time series analysis has made considerable achievements in the recent years. By mapping mono/multivariate time series into networks, one can investigate both it's microscopic and macroscopic behaviors. However, most proposed approaches lead to the construction of static networks consequently providing limited information on evolutionary behaviors. In the present paper we propose a method called visibility graph based time series analysis, in which series segments are mapped to visibility graphs as being descriptions of the corresponding states and the successively occurring states are linked. This procedure converts a time series to a temporal network and at the same time a network of networks. Findings from empirical records for stock markets in USA (S&P500 and Nasdaq and artificial series generated by means of fractional Gaussian motions show that the method can provide us rich information benefiting short-term and long-term predictions. Theoretically, we propose a method to investigate time series from the viewpoint of network of networks.

  7. Visible and occult microscopic lesions of endometriosis

    Directory of Open Access Journals (Sweden)

    Khaleque Newaz Khan

    2014-11-01

    Full Text Available Endometriosis is a multifactorial disease mostly affecting women of reproductive age and is associated with chronic pelvic pain and infertility. Even after 300 years, most of the literature claims that pathogenesis and/or pathophysiology of endometriosis is still elusive. Recurrence of pain and lesion continues to occur after effective medical or surgical therapies. Once generated within the pelvis due to retrograde entry of menstrual debris, peritoneal endometriotic lesions time-dependently change their color appearance resulting from certain biochemical change within lesions. A variable pattern of endometriotic lesions within the pelvis can be detected by laparoscopy as visible peritoneal endometriosis. It is generally believed that besides ovarian steroid hormones, the growth of endometriosis can be regulated by the innate immune system in the pelvic microenvironment by their interaction with endometrial cells and immune cells. Even with the careful eyes of an expert surgeon, we may sometimes miss detecting peritoneal lesion within the peritoneal cavity or deep into the peritoneum. In such a case, random collection of normal peritoneum may carry the possibility to identify some hidden endometriotic lesions by microscopy and these lesions can be named as occult (invisible microscopic endometriosis (OME. Here, we discuss the color appearance of peritoneal lesions and activity of these lesions by analysis of a panel of activity markers. Finally we discuss our recent findings on OME, their biological and clinical significance, and try to make a possible link in the origin between visible endometriosis and OME.

  8. Visible high power fiber coupled diode lasers

    Science.gov (United States)

    Köhler, Bernd; Drovs, Simon; Stoiber, Michael; Dürsch, Sascha; Kissel, Heiko; Könning, Tobias; Biesenbach, Jens; König, Harald; Lell, Alfred; Stojetz, Bernhard; Löffler, Andreas; Strauß, Uwe

    2018-02-01

    In this paper we report on further development of fiber coupled high-power diode lasers in the visible spectral range. New visible laser modules presented in this paper include the use of multi single emitter arrays @ 450 nm leading to a 120 W fiber coupled unit with a beam quality of 44 mm x mrad, as well as very compact modules with multi-W output power from 405 nm to 640 nm. However, as these lasers are based on single emitters, power scaling quickly leads to bulky laser units with a lot of optical components to be aligned. We also report on a new approach based on 450 nm diode laser bars, which dramatically reduces size and alignment effort. These activities were performed within the German government-funded project "BlauLas": a maximum output power of 80 W per bar has been demonstrated @ 450 nm. We show results of a 200 μm NA0.22 fiber coupled 35 W source @ 450 nm, which has been reduced in size by a factor of 25 compared to standard single emitter approach. In addition, we will present a 200 μm NA0.22 fiber coupled laser unit with an output power of 135 W.

  9. Visibility of minute objects with low contrast

    International Nuclear Information System (INIS)

    Sato, Nobuo

    1982-01-01

    Minimum perceptible contrast was obtained with a penetrameter made of aluminum plates, in which 40 very small holes were perforated. An object can be seen when its contrast exceeds the minimum perceptible contrast. Visual threshold contrast ratio offers minimum perceptible diameter (MPD) which is theoretically obtained from an image contrast corresponding to the technique applied. The MPDs were obtained prior to experiment as a function of system speed, beam quality, exposure range and magnification, which resulted in a reasonable agreement with the experimental results. The visibility of small dot-like objects depends on the granularity as its threshold is governed by the surrounding grainy noise. However it was revealed that MTF was as important as granularity. Dot and lineshaped objects were simulated with small glass beads and nylon fibrils, respectively, in order to make ROC analysis on the different radiographic techniques with a CGR Senograph 500T mammographic unit. The 1.5X magnification technique showed the largest advantage on phantom work basis, but clinical evaluation showed the different weight of the affecting physical factors. The results of ROC analysis were extended to entropy analysis. The visibility in actual mammography depends upon the acutance of images as Xeroradiography proved. (Kako, I.)

  10. UV/visible albedos from airborne measurements

    Science.gov (United States)

    Webb, A.; Kylling, A.; Stromberg, I.

    2003-04-01

    During the INSPECTRO campaign effective surface albedo was measured at UV and visible wavelengths from two airborne platforms, a Cessna light aircraft and a hot air balloon. On board the Cessna was a scanning spectroradiometer measuring from 300 - 500nm at 10nm intervals. The NILU cube, with 6 faces and two UV channels at 312 and 340nm, was suspended beneath the hot air balloon. Flights took place over East Anglia during September, 2002. Balloon flights were made below cloud layers, while the Cessna flew both above and below cloud. The Cessna also flew over Barton Bendish, where surface albedos have been measured for ground truthing of satellite data, and measured the effective albedo at four visible wave- lengths in the centres of the satellite bandpass functions. Results of measurements from the different platforms are compared, and model simulations used to deduce the surface albedo from the effective albedo at altitude, giving, for example, an albedo of 0.02 ± 0.01 at 340nm.

  11. Visible light communication applications in healthcare.

    Science.gov (United States)

    Muhammad, Shoaib; Qasid, Syed Hussain Ahmed; Rehman, Shafia; Rai, Aitzaz Bin Sulltan

    2016-01-01

    With the development in science, methods of communication are also improved, replacing old ones with new advanced ways in an attempt to make data transfer more secure, safer for health, and time as well as cost efficient. One of such methods is Visible Light Communication, as the name implies data is transferred through a light equipment such as incandescent or florescent bulb having speed of 10 Kb/s or LEDs approaching speed of 500 Mb/s [1]. VLC uses visible light between 384 and 789 THz [2,3]. Though range is limitation of VLC, however data transfer up-to distance of 1 to 2 km although at lower transfer rate has been reached.The VLC system comprises of light source like LED and receiver equipment, however, with advancement, now LEDs are used for both sending and receiving data. LED remains on all the time, and there is no change in brightness level during the whole process, making it safe for eyes. Currently, VLC system is facing some serious technical challenges before it could be applied in daily life.

  12. Accessibility analysis in manufacturing processes using visibility cones

    Institute of Scientific and Technical Information of China (English)

    尹周平; 丁汉; 熊有伦

    2002-01-01

    Accessibility is a kind of important design feature of products,and accessibility analysis has been acknowledged as a powerful tool for solving computational manufacturing problems arising from different manufacturing processes.After exploring the relations among approachability,accessibility and visibility,a general method for accessibility analysis using visibility cones (VC) is proposed.With the definition of VC of a point,three kinds of visibility of a feature,namely complete visibility cone (CVC),partial visibility cone (PVC) and local visibility cone (LVC),are defined.A novel approach to computing VCs is formulated by identifying C-obstacles in the C-space,for which a general and efficient algorithm is proposed and implemented by making use of visibility culling.Lastly,we discuss briefly how to realize accessibility analysis in numerically controlled (NC) machining planning,coordinate measuring machines (CMMs) inspection planning and assembly sequence planning with the proposed methods.

  13. Efficient resource allocation scheme for visible-light communication system

    Science.gov (United States)

    Kim, Woo-Chan; Bae, Chi-Sung; Cho, Dong-Ho; Shin, Hong-Seok; Jung, D. K.; Oh, Y. J.

    2009-01-01

    A visible-light communication utilizing LED has many advantagies such as visibility of information, high SNR (Signal to Noise Ratio), low installation cost, usage of existing illuminators, and high security. Furthermore, exponentially increasing needs and quality of LED have helped the development of visible-light communication. The visibility is the most attractive property in visible-light communication system, but it is difficult to ensure visibility and transmission efficiency simultaneously during initial access because of the small amount of initial access process signals. In this paper, we propose an efficient resource allocation scheme at initial access for ensuring visibility with high resource utilization rate and low data transmission failure rate. The performance has been evaluated through the numerical analysis and simulation results.

  14. Reflectance measurements of leaves for detecting visible and non-visible ozon damage to crops

    International Nuclear Information System (INIS)

    Kraft, M.; Weigel, H.-J.; Mejer, G.-J.; Brandes, F.

    1996-01-01

    Spring wheat (Triticum aestivum cv. Turbo), white clover (Trifolium repens cv. Karina) and maize (Zea mays cv. Bonny) plants were exposed for 20–30 days in open top chambers to charcoal-filtered air (CF, control) and CF air supplied with O 3 for 8–12 h/per day in the concentration range of 180–240 μg O 3 /m 3 (8–12 h/day treatment mean). At the end of the O 3 treatment spectral reflectance measurements were made on single leaves of all 3 species and on canopies of wheat and clover using a CCD (Charged Coupled Device) camera and wavelength filters with 11 wavelength bands ranging from 450 nm to 950 nm. Different vegetation indices such as the normalized difference vegetation index (NDVI) and the ≪main inflection point≫ (MIP) were calculated. Based on these results it was shown that visible O 3 damages were correlated to the spectral reflectance changes: Both leaves and canopies showed an increased reflectance of visible light after ozone treatment. While clover and maize leaves as well as clover and wheat canopies showed a decreased near infrared (NIR) reflectance, the NIR reflectance of wheat leaves did not change, even if the leaves had visible symptoms. A decreased infrared reflectance was detectable for all clover leaves after O 3 treatment although for part of the leaves no visible foliar damage symptoms could be observed

  15. Visible Lasers and Emerging Color Converters for Lighting and Visible Light Communications

    KAUST Repository

    Shen, Chao

    2017-10-30

    GaN-based lasers are promising for white lighting and visible-light communication (VLC). The advances of III-nitride photonic integration, and the application of YAG crystal and perovskite-based phosphors to lighting and VLC will be discussed.

  16. Visible Lasers and Emerging Color Converters for Lighting and Visible Light Communications

    KAUST Repository

    Shen, Chao

    2017-01-01

    GaN-based lasers are promising for white lighting and visible-light communication (VLC). The advances of III-nitride photonic integration, and the application of YAG crystal and perovskite-based phosphors to lighting and VLC will be discussed.

  17. Contabilidad, Finanzas Empresariales y Mano Visible

    Directory of Open Access Journals (Sweden)

    Juan José Durán Herrera

    2004-01-01

    Full Text Available En el ámbito de la Economía y Dirección de la Empresa, la Contabilidad y las Finanzas juegan un papel primordial por cuanto que, prioritariamente, se ocupan de la determinación del valor de la empresa y, respectivamente, de proporcionar y evaluar la información suplementaria necesaria para la formación de expectativas reales sobre el futuro de dicha organización. En la fuerte interdependencia de los programas de investigación de ambas disciplinas -Contabilidad y Finanzas- se entrecruzan los análisis respectivos de la naturaleza de los activos, del gobierno de la empresa como organización y del cálculo de los resultados alcanzados. La investigación contempla los cambios en las circunstancias (instituciones y organizaciones en las que se desarrolla la función financiera y se aplica la contabilidad para medir e informar sobre la realidad de la empresa, evidenciándose el paralelismo, la complementariedad y las diferencias que se producen entre ambas disciplinas. El valor de la empresa como punto de encuentro manifiesta dos aproximaciones: el valor contable basado en datos históricos o en precios corrientes y el valor financiero que estima el valor actualizando los flujos de caja derivados del desarrollo del proyecto empresa. Palabras clave: contabilidad y finanzas empresariales, información contable y decisiones financieras, dirección financiera y contabilidad, mano visible de la empresa. The theory and practice of Accounting and Finance make possible to estimate the value of the firm and, respectively, both provide and evaluate supplementary information that constitudes inputs for the expectations about the nature of organization. The strong interdependence between the researtch programs in both academic disciplines are show in their own analysis about the nature of assets, the governance of the firm and the determination of the profitability of the corporation. The institutional changes influence the research programs of both

  18. Ultraviolet-visible spectroscopy of graphene oxides

    Directory of Open Access Journals (Sweden)

    Qi Lai

    2012-09-01

    Full Text Available Dispersions of few-layer (1-3 layers, multi-layer (4-10 layers and thick-layer (>10 layers graphene oxide (GO were prepared by a modified Hummers method with different mass ratios of KMnO4 to graphite. Ultraviolet-visible (UV-vis spectroscopic data show that few-layer GO dispersions can be distinguished from multi- and thick-layer dispersions by a more intense peak at 230 nm. Atomic force microscopy (AFM images of few-layer GO contain a single peak, those of multi-layer GO exhibit a shoulder and those of thick-layer GO do not contain a peak or shoulder. These findings allow qualitative analysis of GO dispersions. X-ray photoelectron spectra (XPS show that the change of UV-vis absorption intensity of GO is caused by a conjugative effect related to chromophore aggregation that influences the π-π* plasmon peak.

  19. Nanoantennas for visible and infrared radiation

    International Nuclear Information System (INIS)

    Biagioni, Paolo; Huang, Jer-Shing; Hecht, Bert

    2012-01-01

    Nanoantennas for visible and infrared radiation can strongly enhance the interaction of light with nanoscale matter by their ability to efficiently link propagating and spatially localized optical fields. This ability unlocks an enormous potential for applications ranging from nanoscale optical microscopy and spectroscopy over solar energy conversion, integrated optical nanocircuitry, opto-electronics and density-of-states engineering to ultra-sensing as well as enhancement of optical nonlinearities. Here we review the current understanding of metallic optical antennas based on the background of both well-developed radiowave antenna engineering and plasmonics. In particular, we discuss the role of plasmonic resonances on the performance of nanoantennas and address the influence of geometrical parameters imposed by nanofabrication. Finally, we give a brief account of the current status of the field and the major established and emerging lines of investigation in this vivid area of research.

  20. Nanoantennas for visible and infrared radiation

    Energy Technology Data Exchange (ETDEWEB)

    Biagioni, Paolo [CNISM-Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Huang, Jer-Shing [Department of Chemistry and Frontier Research Center on Fundamental and Applied Science of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Hecht, Bert [Nano-Optics and Biophotonics Group, Department of Experimental Physics 5, Wilhelm Conrad Roentgen Research Center for Complex Material Systems (RCCM), Physics Institute, University of Wuerzburg, Am Hubland, D-97074 Wuerzburg (Germany)

    2012-02-15

    Nanoantennas for visible and infrared radiation can strongly enhance the interaction of light with nanoscale matter by their ability to efficiently link propagating and spatially localized optical fields. This ability unlocks an enormous potential for applications ranging from nanoscale optical microscopy and spectroscopy over solar energy conversion, integrated optical nanocircuitry, opto-electronics and density-of-states engineering to ultra-sensing as well as enhancement of optical nonlinearities. Here we review the current understanding of metallic optical antennas based on the background of both well-developed radiowave antenna engineering and plasmonics. In particular, we discuss the role of plasmonic resonances on the performance of nanoantennas and address the influence of geometrical parameters imposed by nanofabrication. Finally, we give a brief account of the current status of the field and the major established and emerging lines of investigation in this vivid area of research.

  1. Common origin of visible and dark universe

    International Nuclear Information System (INIS)

    Gu Peihong; Sarkar, Utpal

    2010-01-01

    Dark matter, baryonic matter, and dark energy have different properties but contribute comparable energy density to the present Universe. We point out that they may have a common origin. As the dark energy has a scale far lower than all known scales in particle physics but very close to neutrino masses, while the excess matter over antimatter in the baryonic sector is probably related to the neutrino-mass generation, we unify the origin of the dark and visible universe in a variant of the seesaw model. In our model (i) the dark matter relic density is a dark matter asymmetry emerged simultaneously with the baryon asymmetry from leptogenesis; (ii) the dark energy is due to a pseudo-Nambu-Goldstone-Boson associated with the neutrino-mass generation.

  2. Visibility and Invisibility: the Work of Women

    Directory of Open Access Journals (Sweden)

    Patricia Alejandra Collado

    2009-01-01

    Full Text Available The crisis of employment, combined with theories about the end of work, place labor at the center of the agenda. Given this situation, it is found that debates around labor in general (its productive and reproductive spheres, its relation with employment and the visible and invisible forms of conducting work have been approached by one of the most neglected traditions of social thinking: feminism. Feminist thinkers have questioned the meaning of work and non-work in relation to the constant increase of the participation of women in the labor market. Although feminist proposals have different levels of analysis and emphasis, it is necessary to return to their unique production, in order to unveil the situation of greater exploitation and oppression, of workers in general and in particular of women. This situation is facilitated by the apparent “invisibilization” or by the loss of the centrality of labor.

  3. Galactic optical cloaking of visible baryonic matter

    Science.gov (United States)

    Smolyaninov, Igor I.

    2018-05-01

    Three-dimensional gravitational cloaking is known to require exotic matter and energy sources, which makes it arguably physically unrealizable. On the other hand, typical astronomical observations are performed using one-dimensional paraxial line of sight geometries. We demonstrate that unidirectional line of sight gravitational cloaking does not require exotic matter, and it may occur in multiple natural astronomical scenarios that involve gravitational lensing. In particular, recently discovered double gravitational lens SDSSJ 0 9 4 6 +1 0 0 6 together with the Milky Way appear to form a natural paraxial cloak. A natural question to ask, then, is how much matter in the Universe may be hidden from view by such natural gravitational cloaks? It is estimated that the total volume hidden from an observer by gravitational cloaking may reach about 1% of the total volume of the visible Universe.

  4. Visible imaging of edge fluctuations in TFTR

    International Nuclear Information System (INIS)

    Zweben, S.J.; Medley, S.S.

    1989-03-01

    Images of the visible light emission from the inner wall region of TFTR have been made using a rapidly gated, intensified TV camera. Strong ''filamentation'' of the neutral deuterium Dα light is observed when the camera gating time is <100 μsec during neutral-beam-heated discharges. These turbulent filaments vary in position randomly vs. time and have a poloidal wavelength of ∼3-5 cm which is much shorter than their parallel wavelength of ∼100 cm. A second and new type of edge fluctuation phenomenon, which we call a ''merfe,'' is also described. Merfes are a regular poloidal pattern of toroidally symmetric, small-scale marfes which move away from the inner midplane during the current decay after neutral beam injection. Some tentative interpretations of these two phenomena are presented. 27 refs., 8 figs

  5. PAPR analysis for OFDM visible light communication.

    Science.gov (United States)

    Wang, Jiaheng; Xu, Yang; Ling, Xintong; Zhang, Rong; Ding, Zhi; Zhao, Chunming

    2016-11-28

    Orthogonal frequency-division multiplexing (OFDM) is a practical technology in visible light communication (VLC) for high-speed transmissions. However, one of its operational limitations is the peak-to-average power ratio (PAPR) of the transmitted signal. In this paper, we analyze the PAPR distributions of four VLC OFDM schemes, namely DC-biased optical OFDM (DCO-OFDM), asymmetrically clipped optical OFDM (ACO-OFDM), pulse amplitude modulated discrete multitone (PAM-DMT), and Flip-OFDM. Both lower and upper clippings are considered. We analytically derive the complementary cumulative distribution functions (CCDFs) of the PAPRs of the clipped VLC OFDM signals, and investigate the impact of lower and upper clippings on PAPR distributions. Our analytical results, as verified by numerical simulations, provide useful insights and guidelines for VLC OFDM system designs.

  6. Electrically Injected UV-Visible Nanowire Lasers

    Energy Technology Data Exchange (ETDEWEB)

    Wang, George T.; Li, Changyi; Li, Qiming; Liu, Sheng; Wright, Jeremy Benjamin; Brener, Igal; Luk, Ting -Shan; Chow, Weng W.; Leung, Benjamin; Figiel, Jeffrey J.; Koleske, Daniel D.; Lu, Tzu-Ming

    2015-09-01

    There is strong interest in minimizing the volume of lasers to enable ultracompact, low-power, coherent light sources. Nanowires represent an ideal candidate for such nanolasers as stand-alone optical cavities and gain media, and optically pumped nanowire lasing has been demonstrated in several semiconductor systems. Electrically injected nanowire lasers are needed to realize actual working devices but have been elusive due to limitations of current methods to address the requirement for nanowire device heterostructures with high material quality, controlled doping and geometry, low optical loss, and efficient carrier injection. In this project we proposed to demonstrate electrically injected single nanowire lasers emitting in the important UV to visible wavelengths. Our approach to simultaneously address these challenges is based on high quality III-nitride nanowire device heterostructures with precisely controlled geometries and strong gain and mode confinement to minimize lasing thresholds, enabled by a unique top-down nanowire fabrication technique.

  7. Growth and characterization of visible diode lasers

    International Nuclear Information System (INIS)

    Shealy, J.R.; Bour, D.P.

    1988-01-01

    The (Al x Ga 1-x )yIn 1-y rho material system, lattice matched to GaAs substrates, has received much attention for use in visible laser diodes emitting in the spectral region λ--650-680 nm. When lattice matched to GaAs (y=0.5), this alloy spans a direct band gap range from --1.85 eV (at x=0) to --2.3 eV (near the T-X crossover at chi--0.7) It was only recently that device quality epitaxial layers have been prepared in this material due to difficulties with liquid phase epitaxial (LPE) and halide vapor phase epitaxial growth.Only organometallic vapor phase epitaxy (OMVPE) and molecular beam epitaxy (MBE) growth techniques have successfully produced AlGainP laser material

  8. Zeff measurements in ATF using visible bremsstrahlung

    International Nuclear Information System (INIS)

    Morita, S.; Richards, R.K.; Horton, L.D.; Isler, R.C.; Crume, E.C. Jr.; Murakami, M.

    1991-04-01

    Measurements of the effective charge Z eff in plasmas with electron cyclotron heating (ECH) and neutral beam injection (NBI) in the Advanced Toroidal Facility (ATF) have been carried out using visible bremsstrahlung. The electron temperature needed for the analysis is calculated from the measured stored energy and electron density. The value of Z eff varies widely depending on experimental conditions. In ECH plasmas it is between 2 and 8. In NBI plasmas, which are subject to radiation collapse, Z eff is between 3 and 5 at the time the stored energy reaches a maximum. However, Z eff is less than 2.5 in quasi-steady medium-density plasmas and is close to 1.2 in the highest-density plasmas, where the average electron density bar n e is of the order of 10 14 cm -3 . 12 refs., 29 figs., 1 tab

  9. The visibility of high-redshift galaxies

    International Nuclear Information System (INIS)

    Phillipps, S.; Davies, J.I.; Disney, M.J.

    1990-01-01

    The most visible galaxies - that is, those which have the largest apparent sizes and isophotal luminosities when seen at a given distance - are those with a particular observed surface brightness. Extending this argument to high-redshift galaxies, it is clear that this optimum surface brightness moves progressively to brighter intrinsic surface brightnesses, so as to counteract the effect of K-corrections and cosmological dimming. Thus the galaxies appearing in faint surveys will be from a population distinctly different from those 'normal' galaxies observed nearby. Galaxies in deep surveys are more likely to be spirals and to be of high surface brightness. This has very important implications for observational studies of galaxy evolution. (author)

  10. Visible digital watermarking system using perceptual models

    Science.gov (United States)

    Cheng, Qiang; Huang, Thomas S.

    2001-03-01

    This paper presents a visible watermarking system using perceptual models. %how and why A watermark image is overlaid translucently onto a primary image, for the purposes of immediate claim of copyright, instantaneous recognition of owner or creator, or deterrence to piracy of digital images or video. %perceptual The watermark is modulated by exploiting combined DCT-domain and DWT-domain perceptual models. % so that the watermark is visually uniform. The resulting watermarked image is visually pleasing and unobtrusive. The location, size and strength of the watermark vary randomly with the underlying image. The randomization makes the automatic removal of the watermark difficult even though the algorithm is known publicly but the key to the random sequence generator. The experiments demonstrate that the watermarked images have pleasant visual effect and strong robustness. The watermarking system can be used in copyright notification and protection.

  11. Visible light emission from porous silicon carbide

    DEFF Research Database (Denmark)

    Ou, Haiyan; Lu, Weifang

    2017-01-01

    Light-emitting silicon carbide is emerging as an environment-friendly wavelength converter in the application of light-emitting diode based white light source for two main reasons. Firstly, SiC has very good thermal conductivity and therefore a good substrate for GaN growth in addition to the small...... lattice mismatch. Secondly, SiC material is abundant, containing no rear-earth element material as commercial phosphor. In this paper, fabrication of porous SiC is introduced, and their morphology and photoluminescence are characterized. Additionally, the carrier lifetime of the porous SiC is measured...... by time-resolved photoluminescence. The ultrashort lifetime in the order of ~70ps indicates porous SiC is very promising for the application in the ultrafast visible light communications....

  12. Visible Light Communications towards 5G

    Directory of Open Access Journals (Sweden)

    S. Zvanovec

    2015-04-01

    Full Text Available 5G networks have to offer extremely high capacity for novel streaming applications. One of the most promising approaches is to embed large numbers of co-operating small cells into the macro-cell coverage area. Alternatively, optical wireless based technologies can be adopted as an alternative physical layer offering higher data rates. Visible light communications (VLC is an emerging technology for future high capacity communication links (it has been accepted to 5GPP in the visible range of the electromagnetic spectrum (~370–780 nm utilizing light-emitting diodes (LEDs simultaneously provide data transmission and room illumination. A major challenge in VLC is the LED modulation bandwidths, which are limited to a few MHz. However, myriad gigabit speed transmission links have already been demonstrated. Non line-of-sight (NLOS optical wireless is resistant to blocking by people and obstacles and is capable of adapting its’ throughput according to the current channel state information. Concurrently, organic polymer LEDs (PLEDs have become the focus of enormous attention for solid-state lighting applications due to their advantages over conventional white LEDs such as ultra-low costs, low heating temperature, mechanical flexibility and large photoactive areas when produced with wet processing methods. This paper discusses development of such VLC links with a view to implementing ubiquitous broadcasting networks featuring advanced modulation formats such as orthogonal frequency division multiplexing (OFDM or carrier-less amplitude and phase modulation (CAP in conjunction with equalization techniques. Finally, this paper will also summarize the results of the European project ICT COST IC1101 OPTICWISE (Optical Wireless Communications - An Emerging Technology dealing VLC and OLEDs towards 5G networks.

  13. Technology Advancement of the Visible Nulling Coronagraph

    Science.gov (United States)

    Lyon, Richard G.; Clampin, Mark; Petrone, Peter; Thompson, Patrick; Bolcar, Matt; Madison, Timothy; Woodruff, Robert; Noecker, Charley; Kendrick, Steve

    2010-01-01

    The critical high contrast imaging technology for the Extrasolar Planetary Imaging Coronagraph (EPIC) mission concept is the visible nulling coronagraph (VNC). EPIC would be capable of imaging jovian planets, dust/debris disks, and potentially super-Earths and contribute to answering how bright the debris disks are for candidate stars. The contrast requirement for EPIC is 10(exp 9) contrast at 125 milli-arseconds inner working angle. To advance the VNC technology NASA/Goddard Space Flight Center, in collaboration with Lockheed-Martin, previously developed a vacuum VNC testbed, and achieved narrowband and broadband suppression of the core of the Airy disk. Recently our group was awarded a NASA Technology Development for Exoplanet Missions to achieve two milestones: (i) 10(exp 8) contrast in narrowband light, and, (ii) 10(ecp 9) contrast in broader band light; one milestone per year, and both at 2 Lambda/D inner working angle. These will be achieved with our 2nd generation testbed known as the visible nulling testbed (VNT). It contains a MEMS based hex-packed segmented deformable mirror known as the multiple mirror array (MMA) and coherent fiber bundle, i.e. a spatial filter array (SFA). The MMA is in one interferometric arm and works to set the wavefront differences between the arms to zero. Each of the MMA segments is optically mapped to a single mode fiber of the SFA, and the SFA passively cleans the sub-aperture wavefront error leaving only piston, tip and tilt error to be controlled. The piston degree of freedom on each segment is used to correct the wavefront errors, while the tip/tilt is used to simultaneously correct the amplitude errors. Thus the VNT controls both amplitude and wavefront errors with a single MMA in closed-loop in a vacuum tank at approx.20 Hz. Herein we will discuss our ongoing progress with the VNT.

  14. Prediction of fog/visibility over India using NWP Model

    Science.gov (United States)

    Singh, Aditi; George, John P.; Iyengar, Gopal Raman

    2018-03-01

    Frequent occurrence of fog in different parts of northern India is common during the winter months of December and January. Low visibility conditions due to fog disrupt normal public life. Visibility conditions heavily affect both surface and air transport. A number of flights are either diverted or cancelled every year during the winter season due to low visibility conditions, experienced at different airports of north India. Thus, fog and visibility forecasts over plains of north India become very important during winter months. This study aims to understand the ability of a NWP model (NCMRWF, Unified Model, NCUM) with a diagnostic visibility scheme to forecast visibility over plains of north India. The present study verifies visibility forecasts obtained from NCUM against the INSAT-3D fog images and visibility observations from the METAR reports of different stations in the plains of north India. The study shows that the visibility forecast obtained from NCUM can provide reasonably good indication of the spatial extent of fog in advance of one day. The fog intensity is also predicted fairly well. The study also verifies the simple diagnostic model for fog which is driven by NWP model forecast of surface relative humidity and wind speed. The performance of NWP model forecast of visibility is found comparable to that from simple fog model driven by NWP forecast of relative humidity and wind speed.

  15. Topological properties of the limited penetrable horizontal visibility graph family

    Science.gov (United States)

    Wang, Minggang; Vilela, André L. M.; Du, Ruijin; Zhao, Longfeng; Dong, Gaogao; Tian, Lixin; Stanley, H. Eugene

    2018-05-01

    The limited penetrable horizontal visibility graph algorithm was recently introduced to map time series in complex networks. In this work, we extend this algorithm to create a directed-limited penetrable horizontal visibility graph and an image-limited penetrable horizontal visibility graph. We define two algorithms and provide theoretical results on the topological properties of these graphs associated with different types of real-value series. We perform several numerical simulations to check the accuracy of our theoretical results. Finally, we present an application of the directed-limited penetrable horizontal visibility graph to measure real-value time series irreversibility and an application of the image-limited penetrable horizontal visibility graph that discriminates noise from chaos. We also propose a method to measure the systematic risk using the image-limited penetrable horizontal visibility graph, and the empirical results show the effectiveness of our proposed algorithms.

  16. Measurement of infrared optical constants with visible photons

    Science.gov (United States)

    Paterova, Anna; Yang, Hongzhi; An, Chengwu; Kalashnikov, Dmitry; Krivitsky, Leonid

    2018-04-01

    We demonstrate a new scheme for infrared spectroscopy with visible light sources and detectors. The technique relies on the nonlinear interference of correlated photons, produced via spontaneous parametric down conversion in a nonlinear crystal. Visible and infrared photons are split into two paths and the infrared photons interact with the sample under study. The photons are reflected back to the crystal, resembling a conventional Michelson interferometer. Interference of the visible photons is observed and it is dependent on the phases of all three interacting photons: pump, visible and infrared. The transmission coefficient and the refractive index of the sample in the infrared range can be inferred from the interference pattern of visible photons. The method does not require the use of potentially expensive and inefficient infrared detectors and sources, it can be applied to a broad variety of samples, and it does not require a priori knowledge of sample properties in the visible range.

  17. Visibility graph analysis on heartbeat dynamics of meditation training

    Science.gov (United States)

    Jiang, Sen; Bian, Chunhua; Ning, Xinbao; Ma, Qianli D. Y.

    2013-06-01

    We apply the visibility graph analysis to human heartbeat dynamics by constructing the complex networks of heartbeat interval time series and investigating the statistical properties of the network before and during chi and yoga meditation. The experiment results show that visibility graph analysis can reveal the dynamical changes caused by meditation training manifested as regular heartbeat, which is closely related to the adjustment of autonomous neural system, and visibility graph analysis is effective to evaluate the effect of meditation.

  18. Infrared and visible fusion face recognition based on NSCT domain

    Science.gov (United States)

    Xie, Zhihua; Zhang, Shuai; Liu, Guodong; Xiong, Jinquan

    2018-01-01

    Visible face recognition systems, being vulnerable to illumination, expression, and pose, can not achieve robust performance in unconstrained situations. Meanwhile, near infrared face images, being light- independent, can avoid or limit the drawbacks of face recognition in visible light, but its main challenges are low resolution and signal noise ratio (SNR). Therefore, near infrared and visible fusion face recognition has become an important direction in the field of unconstrained face recognition research. In this paper, a novel fusion algorithm in non-subsampled contourlet transform (NSCT) domain is proposed for Infrared and visible face fusion recognition. Firstly, NSCT is used respectively to process the infrared and visible face images, which exploits the image information at multiple scales, orientations, and frequency bands. Then, to exploit the effective discriminant feature and balance the power of high-low frequency band of NSCT coefficients, the local Gabor binary pattern (LGBP) and Local Binary Pattern (LBP) are applied respectively in different frequency parts to obtain the robust representation of infrared and visible face images. Finally, the score-level fusion is used to fuse the all the features for final classification. The visible and near infrared face recognition is tested on HITSZ Lab2 visible and near infrared face database. Experiments results show that the proposed method extracts the complementary features of near-infrared and visible-light images and improves the robustness of unconstrained face recognition.

  19. Advanced factory managing technology. Sentan kojo kanri gijuts

    Energy Technology Data Exchange (ETDEWEB)

    Matsushita, M [Daicel Chemical Industries, Ltd., Osaka (Japan)

    1994-04-05

    With respect to a managing technology of advanced factories in the Japanese chemical industry, this paper enumerates the following three examples to discuss the ways the future factory technologies should be: operation techniques and problems in a newest ethylene plant, operation supports and facility control in chemical factories, and CIM structuring in beer breweries. The paper describes the operation techniques in an ethylene plant that are broken down into the following: measures for safety and material diversification, environment preservation, means to minimize the required labor, adoption of multi-variables, non-interference control technology for ethylene-propylene columns, and operation techniques that have been introduced with such a new technique as an integrated instrumentation room equipped with a gas leakage detection system. Structuring of CIM in the cited beer brewery has followed the transition of IE-TQC-JIT-FMS-CIM. Although a beer brewery may give somewhat different image from an ordinary chemical plant, the beer brewing process resembles a chemical plant in that it operates reacting machines in batch multiple tanks, and uses instrumentations and controllers using sensors. The key point in the future development is an organic link between market fluctuation and production activities. 1 fig.

  20. A proposed visible FEL Facility at Boeing

    Energy Technology Data Exchange (ETDEWEB)

    Dowell, D.H.; Adamski, J.L.; Hayward, T.D. [Boeing Defense & Space Group, Seattle, WA (United States)] [and others

    1995-12-31

    A 1-kW average power, visible wavelength FEL is described, based on a 120-MeV, 0.1. A macropulse average current linac operating at a duty factor of 0. 6% and having average beam power of 70 kW. The accelerator will employ a demonstrated photoinjector, 18-MeV, 433-MHz linac as an injector, followed by a 1300-MHz longitudinal phase space {open_quotes} linearizer,{close_quotes} a magnetic buncher chicane, and seven 1300-MHz, pulsed traveling wave linac sections. The magnets used to transport the beam from the linac to the FEL centerline, the 5-m THUNDER wiggler, and the optical resonator will be reclaimed from previous FEL demonstration experiments. We expect to attain pulse lengths of 7 ps for 3.5 nC, with minimal distortion of the pulse profile and normalized rms emittance of 7.5 {+-} 2.5 {pi} mm-mr. FELEX projects a laser conversion efficiency of 4.3 %, yielding average output of 3 kW.

  1. Ultraviolet and Visible Emission Mechanisms in Astrophysics

    Science.gov (United States)

    Stancil, Phillip C.; Schultz, David R.

    2003-01-01

    The project involved the study of ultraviolet (UV) and visible emission mechanisms in astrophysical and atmospheric environments. In many situations, the emission is a direct consequence of a charge transferring collision of an ion with a neutral with capture of an electron to an excited state of the product ion. The process is also important in establishing the ionization and thermal balance of an astrophysical plasma. As little of the necessary collision data are available, the main thrust of the project was the calculation of total and state-selective charge transfer cross sections and rate coefficients for a very large number of collision systems. The data was computed using modern explicit techniques including the molecular-orbital close-coupling (MOCC), classical trajectory Monte Carlo (CTMC), and continuum distorted wave (CDW) methods. Estimates were also made in some instances using the multichannel Landau-Zener (MCLZ) and classical over-the-barrier (COB) models. Much of the data which has been computed has been formatted for inclusion in a charge transfer database on the World Wide Web (cfadc.phy.ornl.gov/astro/ps/data/). A considerable amount of data has been generated during the lifetime of the grant. Some of it has not been analyzed, but it will be as soon as possible, the data placed on our website, and papers ultimately written.

  2. Metasurface axicon lens design at visible wavelengths

    Science.gov (United States)

    Alyammahi, Saleimah; Zhan, Qiwen

    2017-08-01

    The emerging field of metasurfaces is promising to realize novel optical devices with miniaturized flat format and added functionalities. Metasurfaces have been demonstrated to exhibit full control of amplitude, phase and polarization of electromagnetic waves. Using the metasurface, the wavefront of light can be manipulated permitting new functionalities such as focusing and steering of the beams and imaging. One optical component which can be designed using metasurfaces is the axicon. Axicons are conical lenses used to convert Gaussian beams into nondiffraction Bessel beams. These unique devices are utilized in different applications ranging from optical trapping and manipulation, medical imaging, and surgery. In this work, we study axicon lens design comprising of planar metasurfaces which generate non-diffracting Bessel beams at visible wavelengths. Dielectric metasurfaces have been used to achieve high efficiency and low optical loss. We measured the spot size of the resulted beams at different planes to demonstrate the non-diffraction properties of the resulted beams. We also investigated how the spot size is influenced by the axicon aperture. Furthermore, we examined the achromatic properties of the designed axicon. Comparing with the conventional lens, the metasurface axicon lens design enables the creation of flat optical device with wide range of depth of focus along its optical axis.

  3. Nanopatterned organic semiconductors for visible light communications

    Science.gov (United States)

    Yang, Xilu; Dong, Yurong; Zeng, Pan; Yu, Yan; Xie, Yujun; Gong, Junyi; Shi, Meng; Liang, Rongqing; Ou, Qiongrong; Chi, Nan; Zhang, Shuyu

    2018-03-01

    Visible light communication (VLC) is becoming an important and promising supplement to the existing Wi-Fi network for the coming 5G communications. Organic light-emitting semiconductors present much fast fluorescent decay rates compared to those of conventional colour-converting phosphors, therefore capable of achieving much higher bandwidths. Here we explore how nanopatterned organic semiconductors can further enhance the data rates of VLC links by improving bandwidths and signal-to-noise ratios (SNRs) and by supporting spatial multiplexing. We first demonstrate a colour-converting VLC system based on nanopatterned hyperbolic metamaterials (HMM), the bandwidth of which is enhanced by 50%. With regard to enhancing SNRs, we achieve a tripling of optical gain by integrating a nanopatterned luminescent concentrator to a signal receiver. In addition, we demonstrate highly directional fluorescent VLC antennas based on nanoimprinted polymer films, paving the way to achieving parallel VLC communications via spatialmultiplexing. These results indicate nanopatterned organic semiconductors provide a promising route to high speed VLC links.

  4. Recent developments with the visible nulling coronagraph

    Science.gov (United States)

    Hicks, Brian A.; Lyon, Richard G.; Bolcar, Matthew R.; Clampin, Mark; Petrone, Peter; Helmbrecht, Michael A.; Howard, Joseph M.; Miller, Ian J.

    2016-08-01

    A wide array of general astrophysics studies including detecting and characterizing habitable exoplanets could be enabled by a future large segmented telescope with sensitivity in the UV, optical, and infrared bands. When paired with a starshade or coronagraph, such an observatory could enable direct imaging and detailed spectroscopic observations of nearby Earth-like habitable zone planets. Over the past several years, a laboratory-based Visible Nulling Coronagraph (VNC) has evolved to reach requisite contrasts over a 1 nm bandwidth at narrow source angle separation using a segmented deformable mirror in one arm of a Mach-Zehnder layout. More recent efforts targeted broadband performance following the addition of two sets of half-wave Fresnel rhomb achromatic phase shifters (APS) with the goal of reaching 10-9 contrast, at a separation of 2λ/D, using a 40 nm (6%) bandwidth single mode fiber source. Here we present updates on the VNC broadband nulling effort, including approaches to addressing system contrast limitations.

  5. Deuterium abundance, from ultraviolet to visible

    International Nuclear Information System (INIS)

    Hebrard, Guillaume

    2000-01-01

    In the frame of the standard Big Bang model, the primordial abundance of deuterium is the most sensitive to the baryonic density of the Universe. It was synthesized only during the primordial nucleosynthesis few minutes after the Big Bang and no other standard mechanism is able to produce any further significant amount. On the contrary, since deuterium is burned up within stars, its abundance D/H decreases along cosmic evolution. Thus, D/H measurements constrain Big Bang and galactic chemical evolution models. There are three samples of deuterium abundances: primordial, proto-solar and interstellar. Each of them is representative of a given epoch, respectively about 15 Gyrs past, 4.5 Gyrs past and present epoch. Although the evolution of the deuterium abundance seems to be qualitatively understood, the measurements show some dispersion. Present thesis works are linked to deuterium interstellar abundance measurements. Such measurements are classically obtained from spectroscopic observations of the hydrogen and deuterium Lyman series in absorption in the ultraviolet spectral range, using space observatories. Results presented here were obtained with the Hubble Space Telescope and FUSE, which has recently been launched. Simultaneously, a new way to observe deuterium has been proposed, in the visible spectral range from ground-based telescopes. This has led to the first detections and the identification of the deuterium Balmer series, in emission in HII regions, using CFHT and VLT telescopes. (author) [fr

  6. Visible Imaging Diagnostic on Tore-Supra

    Energy Technology Data Exchange (ETDEWEB)

    Dachicourt, R.; Monier Garbet, P.; Beaute, A.; Habib-Naiim, M. [Association Euratom-CEA, CEA/DSM/IRFM, CEA Cadarache (France); Marandet, Y. [PIIM, CNRS-Universite de Provence, Marseille (France)

    2011-07-01

    Full text of publication follows: Research for thermonuclear fusion aims at energy production using fusion reactions between deuterium and tritium nuclei. To this end, a deuterium/tritium mixture has to be heated to a very high temperature (about 100 millions degrees). Chemical and physical sputtering erodes the plasma facing components (PFC), leading to an impurity influx to the plasma. Estimating this erosion source is important both for the PFC lifetime and the quality of the confinement. In fact, impurities reaching the plasma core radiate energy and dilute the fuel. In this contribution, we describe an erosion diagnostic operated on the Tore Supra tokamak, consisting in the combination of visible spectroscopy and filtered imaging over a full TPL (Toroidal Pumped Limiter) sector. Quantitative measurements of spectral lines brightness on four spectrometer chords monitoring the TPL top are used to process the corresponding filtered images, namely to remove background emission or unwanted lines. The particle influx from the TPL's vicinity is obtained from photon fluxes measurements [1], which require absolute calibration in intensity of the system. Filtered images provide the spatial pattern of erosion, from which the total eroded carbon flux is reconstructed. The variation of the particle influx with the input power is studied by analyzing a dedicated experimental campaign. References: [1] Behringer K. et al. Plasma Physics and Controlled Fusion, Vol. 31, No. 14, pp. 2059 to 2099, 1989. (authors)

  7. Catadioptric lenses in Visible Light Communications

    Science.gov (United States)

    Garcia-Marquez, J.; Valencia, J. C.; Perez, H.; Topsu, S.

    2015-04-01

    Since few years ago, visible light communications (VLC) have experience an accelerated interest from a research point of view. The beginning of this decade has seen many improvements in VLC at an electronic level. High rates of transmission at low bit error ratios (BER) have been reported. A few numbers of start-ups have initiated activities to offer a variety of applications ranging from indoor geo-localization to internet, but in spite of these advancements, some other problems arise. Long-range transmissions mean a high BER which reduce the number of applications. In this sense, new redesigned optical collectors or in some cases, optical reflectors must be considered to ensure a low BER at higher distance transmissions. Here we also expose a preliminary design of a catadioptric and monolithical lens for a LI-FI receiver with two rotationally symmetrical main piecewise surfaces za and zb. These surfaces are represented in a system of cylindrical coordinates with an anterior surface za with a central and refractive sector surrounded by a peripheral reflective sector and a back piecewise surface zb with a central refractive sector and a reflective sector, both characterized as ideal for capturing light within large acceptance angles.

  8. Some new possibilities in direct visible and x ray measurements

    International Nuclear Information System (INIS)

    Gex, J.P.; Sauneuf, R.; Boutot, J.P.; Delmotte, J.C.

    1979-01-01

    Subnanosecond photodetection measurements in visible and X ray range with vacuum cell and very thin microchannel plate phototube (coupled with a fast scintillator or not) in conjunction with fast oscilloscope (5 GHz) are presented. They are compared to those given by a visible or a gold photocathode X-ray streak camera (temporal resolution better than 20 ps). (author)

  9. Prediction of Fog/Visibility over India using NWP Model

    Indian Academy of Sciences (India)

    54

    fog which is driven by NWP model forecast of surface relative humidity and wind speed. The performance of NWP model forecast of visibility is found comparable to that from simple fog model driven by NWP forecast of relative humidity and wind speed. Keywords: Visibility, Fog, Insat-3D, METARS, NCUM, North India.

  10. Gesturing on the Telephone: Independent Effects of Dialogue and Visibility

    Science.gov (United States)

    Bavelas, Janet; Gerwing, Jennifer; Sutton, Chantelle; Prevost, Danielle

    2008-01-01

    Speakers often gesture in telephone conversations, even though they are not visible to their addressees. To test whether this effect is due to being in a dialogue, we separated visibility and dialogue with three conditions: face-to-face dialogue (10 dyads), telephone dialogue (10 dyads), and monologue to a tape recorder (10 individuals). For the…

  11. Utilization of Large Scale Surface Models for Detailed Visibility Analyses

    Science.gov (United States)

    Caha, J.; Kačmařík, M.

    2017-11-01

    This article demonstrates utilization of large scale surface models with small spatial resolution and high accuracy, acquired from Unmanned Aerial Vehicle scanning, for visibility analyses. The importance of large scale data for visibility analyses on the local scale, where the detail of the surface model is the most defining factor, is described. The focus is not only the classic Boolean visibility, that is usually determined within GIS, but also on so called extended viewsheds that aims to provide more information about visibility. The case study with examples of visibility analyses was performed on river Opava, near the Ostrava city (Czech Republic). The multiple Boolean viewshed analysis and global horizon viewshed were calculated to determine most prominent features and visibility barriers of the surface. Besides that, the extended viewshed showing angle difference above the local horizon, which describes angular height of the target area above the barrier, is shown. The case study proved that large scale models are appropriate data source for visibility analyses on local level. The discussion summarizes possible future applications and further development directions of visibility analyses.

  12. High power diode lasers converted to the visible

    DEFF Research Database (Denmark)

    Jensen, Ole Bjarlin; Hansen, Anders Kragh; Andersen, Peter E.

    2017-01-01

    High power diode lasers have in recent years become available in many wavelength regions. However, some spectral regions are not well covered. In particular, the visible spectral range is lacking high power diode lasers with good spatial quality. In this paper, we highlight some of our recent...... results in nonlinear frequency conversion of high power near infrared diode lasers to the visible spectral region....

  13. Indigoid Photoswitches: Visible Light Responsive Molecular Tools.

    Science.gov (United States)

    Petermayer, Christian; Dube, Henry

    2018-05-15

    Indigoid photoswitches comprise a class of chromophores that are derived from the parent and well-known indigo dye. Different from most photoswitches their core structures absorb in the visible region of the spectrum in both isomeric states even without substitutions, which makes them especially interesting for applications not tolerant of high-energy UV light. Also different from most current photoswitching systems, they provide highly rigid structures that undergo large yet precisely controllable geometry changes upon photoisomerization. The favorable combination of pronounced photochromism, fast and efficient photoreactions, and high thermal bistability have led to a strongly increased interest in indigoid photoswitches over the last years. As a result, intriguing applications of these chromophores as reversible triggering units in supramolecular and biological chemistry, the field of molecular machines, or smart molecules have been put forward. In this Account current developments in the synthesis, mechanistic understanding of light responsiveness, advantageous properties as phototools, and new applications of indigoid photoswitches are summarized with the focus on hemithioindigo, hemiindigo, and indigo as key examples. Many methods for the synthesis of hemithioindigos are known, but derivatives with a fourth substituent at the double bond could not easily be prepared because of the resulting increased steric hindrance in the products. Recent efforts in our laboratory have provided two different methods to prepare these highly promising photoswitches in very efficient ways. One method is especially designed for the introduction of sterically hindered ketones while the second one allows rapid structural diversification in only three high-yielding synthetic steps. Given the lesser prominence of indigoid photoswitches, mechanistic understanding of their excited state behavior and therefore rational design opportunities for photophysical properties are also much

  14. Eagle-i: Making Invisible Resources, Visible

    Science.gov (United States)

    Haendel, M.; Wilson, M.; Torniai, C.; Segerdell, E.; Shaffer, C.; Frost, R.; Bourges, D.; Brownstein, J.; McInnerney, K.

    2010-01-01

    RP-134 The eagle-i Consortium – Dartmouth College, Harvard Medical School, Jackson State University, Morehouse School of Medicine, Montana State University, Oregon Health and Science University (OHSU), the University of Alaska, the University of Hawaii, and the University of Puerto Rico – aims to make invisible resources for scientific research visible by developing a searchable network of resource repositories at research institutions nationwide. Now in early development, it is hoped that the system will scale beyond the consortium at the end of the two-year pilot. Data Model & Ontology: The eagle-i ontology development team at the OHSU Library is generating the data model and ontologies necessary for resource indexing and querying. Our indexing system will enable cores and research labs to represent resources within a defined vocabulary, leading to more effective searches and better linkage between data types. This effort is being guided by active discussions within the ontology community (http://RRontology.tk) bringing together relevant preexisting ontologies in a logical framework. The goal of these discussions is to provide context for interoperability and domain-wide standards for resource types used throughout biomedical research. Research community feedback is welcomed. Architecture Development, led by a team at Harvard, includes four main components: tools for data collection, management and curation; an institutional resource repository; a federated network; and a central search application. Each participating institution will populate and manage their repository locally, using data collection and curation tools. To help improve search performance, data tools will support the semi-automatic annotation of resources. A central search application will use a federated protocol to broadcast queries to all repositories and display aggregated results. The search application will leverage the eagle-i ontologies to help guide users to valid queries via auto

  15. Determination of localized visibility in off-axis electron holography

    International Nuclear Information System (INIS)

    McLeod, Robert A.; Kupsta, Martin; Malac, Marek

    2014-01-01

    Off-axis electron holography is a wavefront-split interference method for the transmission electron microscope that allows the phase shift and amplitude of the electron wavefront to be separated and quantitatively measured. An additional, third component of the holographic signal is the coherence of the electron wavefront. Historically, wavefront coherence has been evaluated by measurement of the holographic fringe visibility (or contrast) based on the minimum and maximum intensity values. We present a method based on statistical moments is presented that allows allow the visibility to be measured in a deterministic and reproducible fashion suitable for quantitative analysis. We also present an algorithm, based on the Fourier-ratio method, which allows the visibility to be resolved in two-dimensions, which we term the local visibility. The local visibility may be used to evaluate the loss of coherence due to electron scattering within a specimen, or as an aid in image analysis and segmentation. The relationship between amplitude and visibility may be used to evaluate the composition and mass thickness of a specimen by means of a 2-D histogram. Results for a selection of elements (C, Al, Si, Ti, Cr, Cu, Ge, and Au) are provided. All presented visibility metrics are biased at low-dose conditions by the presence of shot-noise, for which we provide methods for empirical normalization to achieve linear response. - Highlights: • Report on a new statistical metric to determine holographic fringe visibility. • Adds new signal to electron holography: measure of electron coherence loss in 2-D. • Provide algorithm to calculate 2-D local visibility map. • Show that amplitude and visibility may be used for compositional analysis and segmentation. • Corrected for data bias such as shot noise

  16. Comparison of Sociometrically High Visibility Rejected and Low Visibility Rejected Children on Teacher, Parent, and Self-Rating Measures.

    Science.gov (United States)

    Neighbor, Jonelle C.

    The study looked at differences between groups of children identified as high visibility rejected (HVR) and low visibility rejected (LVR) on a sociometric measure with 952 fourth, fifth, and sixth grade students. Questionnaires were analyzed to determine the number of positive and negative nominations from peers received by each child. HVR…

  17. A visible light-curable yet visible wavelength-transparent resin for stereolithography 3D printing

    Science.gov (United States)

    Park, Hong Key; Shin, Mikyung; Kim, Bongkyun; Park, Jin Woo; Lee, Haeshin

    2018-04-01

    Herein, a new polymeric resin for stereolithography (SLA) three-dimensional printing (SLA-3DP) is reported. An ultraviolet (UV) or visible (VIS) light source is critical for SLA printing technology. UV light can be used to manufacture 3D objects in SLA-3DP, but there are significant occupational safety and health issues (particularly for eyes). These issues prevent the widespread use of SLA-3DP at home or in the office. Through the use of VIS light, the safety and health issues can largely be solved, but only non-transparent 3D objects can be manufactured, which prevents the application of 3DP to the production of various common transparent consumer products. For these reasons, we developed a VIS light-curable yet visibly transparent resin for SLA-3DP, which also retains UV curability. The key was to identify the photoinitiator diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (DPTBP). DPTBP was originally designed as a UV photoinitiator, but we found that VIS light irradiation is sufficient to split DPTBP and generate radicals due to its slight VIS light absorption up to 420 nm. The cured resin displays high transparency and beautiful transparent colors by incorporating various dyes; additionally, its mechanical properties are superior to those of commercial resins (Arario 410) and photoinitiators (Irgacure 2959).

  18. Website visibility the theory and practice of improving rankings

    CERN Document Server

    Weideman, Melius

    2009-01-01

    The quest to achieve high website rankings in search engine results is a prominent subject for both academics and website owners/coders. Website Visibility marries academic research results to the world of the information practitioner and contains a focused look at the elements which contribute to website visibility, providing support for the application of each element with relevant research. A series of real-world case studies with tested examples of research on website visibility elements and their effect on rankings are reviewed.Written by a well-respected academic and practitioner in the

  19. The Development of Visible-Light Photoredox Catalysis in Flow.

    Science.gov (United States)

    Garlets, Zachary J; Nguyen, John D; Stephenson, Corey R J

    2014-04-01

    Visible-light photoredox catalysis has recently emerged as a viable alternative for radical reactions otherwise carried out with tin and boron reagents. It has been recognized that by merging photoredox catalysis with flow chemistry, slow reaction times, lower yields, and safety concerns may be obviated. While flow reactors have been successfully applied to reactions carried out with UV light, only recent developments have demonstrated the same potential of flow reactors for the improvement of visible-light-mediated reactions. This review examines the initial and continuing development of visible-light-mediated photoredox flow chemistry by exemplifying the benefits of flow chemistry compared with conventional batch techniques.

  20. Integrating visible light 3D scanning into the everyday world

    Science.gov (United States)

    Straub, Jeremy

    2015-05-01

    Visible light 3D scanning offers the potential to non-invasively and nearly non-perceptibly incorporate 3D imaging into the everyday world. This paper considers the various possible uses of visible light 3D scanning technology. It discusses multiple possible usage scenarios including in hospitals, security perimeter settings and retail environments. The paper presents a framework for assessing the efficacy of visible light 3D scanning for a given application (and compares this to other scanning approaches such as those using blue light or lasers). It also discusses ethical and legal considerations relevant to real-world use and concludes by presenting a decision making framework.

  1. Prague-Ruzyne airport visibility data processing results

    Science.gov (United States)

    Kvicera, Vaclav; Grabner, Martin; Vasicek, Jiri

    2010-05-01

    Experimental research in the Department of Frequency Engineering in the Czech Metrology Institute (CMI) in Prague, the Czech Republic, is focused on stability of received signal on terrestrial radio and optical communication links. A free space optical (FSO) communication system can provide a high bandwidth solution to last mile broadband access. Dense fog events can cause serious attenuation of optical waves. The availability performances of FSO links are seriously affected by lower atmospheric visibility. Fog seems to be the most important impairment factor for FSO communication links. Therefore, our experimental research is also focused on processing meteorological data to obtain basic information for the assessment of availability performances of FSO links. The visibility measured at airports provides a good estimate for the assessment of fog impairment. The visibility data that is measured and stored in meteorological stations or airports is usually used for the calculation of specific attenuation due to fog in accordance with either the relevant ITU-R Recommendation or other common methods. Fog visibility data obtained by the Vaisala transmissometer at the Prague-Ruzyne airport from January 1996 to December 2008 (13 years of observation) was statistically processed over the individual years, the individual months and the individual hours and the following cumulative distributions (CDs) of visibility were obtained: 1) CDs of visibility for individual years, 2) CDs of visibility for individual months over the whole period of processing, 3) CDs of visibility for the worst hour over the whole period of processing, and 4) CDs of visibility for the average year and the average worst month over the entire 13 year period of processing. It can be concluded that the frequency of fog events shows a great year-to-year variability in accordance with the frequency of individual synoptic situations occurring during the year. Fog occurred most frequently in November and

  2. Visible-to-visible four-photon ultrahigh resolution microscopic imaging with 730-nm diode laser excited nanocrystals.

    Science.gov (United States)

    Wang, Baoju; Zhan, Qiuqiang; Zhao, Yuxiang; Wu, Ruitao; Liu, Jing; He, Sailing

    2016-01-25

    Further development of multiphoton microscopic imaging is confronted with a number of limitations, including high-cost, high complexity and relatively low spatial resolution due to the long excitation wavelength. To overcome these problems, for the first time, we propose visible-to-visible four-photon ultrahigh resolution microscopic imaging by using a common cost-effective 730-nm laser diode to excite the prepared Nd(3+)-sensitized upconversion nanoparticles (Nd(3+)-UCNPs). An ordinary multiphoton scanning microscope system was built using a visible CW diode laser and the lateral imaging resolution as high as 161-nm was achieved via the four-photon upconversion process. The demonstrated large saturation excitation power for Nd(3+)-UCNPs would be more practical and facilitate the four-photon imaging in the application. A sample with fine structure was imaged to demonstrate the advantages of visible-to-visible four-photon ultrahigh resolution microscopic imaging with 730-nm diode laser excited nanocrystals. Combining the uniqueness of UCNPs, the proposed visible-to-visible four-photon imaging would be highly promising and attractive in the field of multiphoton imaging.

  3. On the Secrecy Capacity of MISO Visible Light Communication Channels

    KAUST Repository

    Arfaoui, Mohamed Amine; Rezki, Zouheir; Ghrayeb, Ali; Alouini, Mohamed-Slim

    2017-01-01

    We study the secrecy capacity of the multiple- input single-output (MISO) Gaussian wiretap visible light communication (VLC) channel. We study a typical VLC scenario with one transmitter, one legitimate receiver, and one eavesdropper. Specifically

  4. Precoded generalized space shift keying for indoor visible light communications

    KAUST Repository

    Kadampot, Ishaque Ashar; Park, Kihong; Alouini, Mohamed-Slim

    2014-01-01

    We consider a visible light communication system with 2 transmit light emitting diodes (LED) and nr receive photodiodes. An optical generalized space shift keying modulation scheme is considered for the transmission of bits where each LED can

  5. Discrete Input Signaling for MISO Visible Light Communication Channels

    KAUST Repository

    Arfaoui, Mohamed Amine; Rezki, Zouheir; Ghrayeb, Ali; Alouini, Mohamed-Slim

    2017-01-01

    In this paper, we study the achievable secrecy rate of visible light communication (VLC) links for discrete input distributions. We consider single user single eavesdropper multiple-input single-output (MISO) links. In addition, both beamforming

  6. Improving Space Surveillance with Space-Based Visible Sensor

    National Research Council Canada - National Science Library

    Sharma, Jayant

    2001-01-01

    ...) sensor, a visible-band electro-optical camera designed at Lincoln Laboratory. The program has just completed three years of Contributing Sensor operations under the Advanced Concept Technology Demonstration (ACTD) program...

  7. Visible Light Responsive Catalyst for Air & Water Purification

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective for this project was to investigate and develop viable approaches to render the normally UV-activated titanium dioxide (TiO2) catalyst visible light...

  8. Mechanochemical Synthesis of Visible Light Sensitive Titanium Dioxide Photocatalyst

    Directory of Open Access Journals (Sweden)

    Jan Šubrt

    2011-01-01

    Full Text Available Phase transition of anatase nanoparticles into the phases TiO2-II and rutile under grinding was studied. The addition of ammonium carbamate to the reaction mixture inhibits the phase conversion and the cold welding of particles. The UV-visible absorption spectrum showed narrowing the band gap width after grinding with an ammonium carbamate additive resulting in shift of the light absorption of the ground sample towards the visible region. By EPR, intensive formation of OH• radical at irradiation of the sample with both UV (λ > 300 nm and visible (λ > 435 nm light was observed. High photocatalytic activity of the ground sample in visible light region was demonstrated also by measurement of kinetics of the photocatalytic decomposition of 4-chlorophenol.

  9. Preservation Values for Visibility Protection at the National Parks (1990)

    Science.gov (United States)

    This report presents the design and results of a study concerning the estimation of preservation values held by the general public for the protection of visibility at national parks from air pollution impacts

  10. NOS CO-OPS Meteorological Data, Visibility, 6-Minute

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has Visibility data from NOAA NOS Center for Operational Oceanographic Products and Services (CO-OPS). WARNING: These preliminary data have not been...

  11. Expanding the Visibility of Women's Work: Policy Implications.

    Science.gov (United States)

    Messias, DeAnne K. Hilfinger; Regev, Hanna; Im, Eun-Ok; Spiers, Judith A.; Van, Paulina; Meleis, Afaf Ibrahim

    1997-01-01

    Social conceptualization and media images of women's work affect health and social policy formation. Nurses can expand the visibility of women's work and promote gender-sensitive policies within and outside the profession. (SK)

  12. Unidirectional visible light communication and illumination with LEDs

    NARCIS (Netherlands)

    Li, S.; Pandharipande, A.; Willems, F.M.J.

    2016-01-01

    Visible light communication (VLC) with light emitting diodes (LEDs) has attracted interest for interactive and networked lighting control, and consumer infotainment applications. In this paper, we propose an LED system for jointly achieving unidirectional VLC while providing flicker-free

  13. Visible Light Communication: An Emerging Area in Wireless

    Indian Academy of Sciences (India)

    A. Chockalingam

    infrared to ultraviolet. • includes visible light wavelengths (380 to 780 nm). Concluding remarks. NH ... low power, high data rate systems in satellites, portable devices, etc. .... improve spectral efficiency and performance. • Issues. • channel ...

  14. A novel mirror diversity receiver for indoor MIMO visible light

    KAUST Repository

    Park, Ki-Hong; Alheadary, Wael G.; Alouini, Mohamed-Slim

    2016-01-01

    In this paper, we propose and study a non-imaging receiver design reducing the correlation of channel matrix for indoor multiple-input multiple-output (MIMO) visible light communication (VLC) systems. Contrary to previous works, our proposed mirror

  15. [Qualitative Determination of Organic Vapour Using Violet and Visible Spectrum].

    Science.gov (United States)

    Jiang, Bo; Hu, Wen-zhong; Liu, Chang-jian; Zheng, Wei; Qi, Xiao-hui; Jiang, Ai-li; Wang, Yan-ying

    2015-12-01

    Vapours of organic matters were determined qualitatively employed with ultraviolet-visible absorption spectroscopy. Vapours of organic matters were detected using ultraviolet-visible spectrophotometer employing polyethylene film as medium, the ultraviolet and visible absorption spectra of vegetable oil vapours of soybean oil, sunflower seed oil, peanut oil, rapeseed oil, sesame oil, cotton seed oil, tung tree seed oil, and organic compound vapours of acetone, ethyl acetate, 95% ethanol, glacial acetic acid were obtained. Experimental results showed that spectra of the vegetable oil vapour and the organic compound vapour could be obtained commendably, since ultra violet and visible spectrum of polyethylene film could be deducted by spectrograph zero setting. Different kinds of vegetable oils could been distinguished commendably in the spectra since the λ(max), λ(min), number of absorption peak, position, inflection point in the ultra violet and visible spectra obtained from the vapours of the vegetable oils were all inconsistent, and the vapours of organic compounds were also determined perfectly. The method had a good reproducibility, the ultraviolet and visible absorption spectra of the vapours of sunflower seed oil in 10 times determination were absolutely the same. The experimental result indicated that polyethylene film as a kind of medium could be used for qualitative analysis of ultraviolet and visible absorption spectroscopy. The method for determination of the vapours of the vegetable oils and organic compounds had the peculiarities of fast speed analysis, well reproducibility, accuracy and reliability and low cost, and so on. Ultraviolet and visible absorption spectrum of organic vapour could provide feature information of material vapour and structural information of organic compound, and provide a novel test method for identifying vapour of compound and organic matter.

  16. Effects of forest fires on visibility and air quality

    Science.gov (United States)

    Douglas G. Fox; Allen R. Riebau

    2009-01-01

    The U.S. Clean Air Act establishes the goal of preventing future and remedying existing visibility impairment in 156 Class I areas (national parks, wilderness areas, and wildlife refuges). A key element in implementing this goal is the Regional Haze Regulation (RHR). RHR is based on relating impaired visibility, using metrics of extinction (inverse megameters and/or ‘‘...

  17. Disease, communication, and the ethics of (in) visibility.

    Science.gov (United States)

    Pietrzak-Franger, Monika Monika; Holmes, Martha Stoddard

    2014-12-01

    As the recent Ebola outbreak demonstrates, visibility is central to the shaping of political, medical, and socioeconomic decisions. The symposium in this issue of the Journal of Bioethical Inquiry explores the uneasy relationship between the necessity of making diseases visible, the mechanisms of legal and visual censorship, and the overall ethics of viewing and spectatorship, including the effects of media visibility on the perception of particular "marked" bodies. Scholarship across the disciplines of communication, anthropology, gender studies, and visual studies, as well as a photographer's visual essay and memorial reflection, throw light on various strategies of visualization and (de)legitimation and link these to broader socioeconomic concerns. Questions of the ethics of spectatorship, such as how to evoke empathy in the representation of individuals' suffering without perpetuating social and economic inequalities, are explored in individual, (trans-)national, and global contexts, demonstrating how disease (in)visibility intersects with a complex nexus of health, sexuality, and global/national politics. A sensible management of visibility--an "ecology of the visible"--can be productive of more viable ways of individual and collective engagement with those who suffer.

  18. Visible light alters yeast metabolic rhythms by inhibiting respiration.

    Science.gov (United States)

    Robertson, James Brian; Davis, Chris R; Johnson, Carl Hirschie

    2013-12-24

    Exposure of cells to visible light in nature or in fluorescence microscopy often is considered to be relatively innocuous. However, using the yeast respiratory oscillation (YRO) as a sensitive measurement of metabolism, we find that non-UV visible light has a significant impact on yeast metabolism. Blue/green wavelengths of visible light shorten the period and dampen the amplitude of the YRO, which is an ultradian rhythm of cell metabolism and transcription. The wavelengths of light that have the greatest effect coincide with the peak absorption regions of cytochromes. Moreover, treating yeast with the electron transport inhibitor sodium azide has similar effects on the YRO as visible light. Because impairment of respiration by light would change several state variables believed to play vital roles in the YRO (e.g., oxygen tension and ATP levels), we tested oxygen's role in YRO stability and found that externally induced oxygen depletion can reset the phase of the oscillation, demonstrating that respiratory capacity plays a role in the oscillation's period and phase. Light-induced damage to the cytochromes also produces reactive oxygen species that up-regulate the oxidative stress response gene TRX2 that is involved in pathways that enable sustained growth in bright visible light. Therefore, visible light can modulate cellular rhythmicity and metabolism through unexpectedly photosensitive pathways.

  19. Quantitative Model for Supply Chain Visibility: Process Capability Perspective

    Directory of Open Access Journals (Sweden)

    Youngsu Lee

    2016-01-01

    Full Text Available Currently, the intensity of enterprise competition has increased as a result of a greater diversity of customer needs as well as the persistence of a long-term recession. The results of competition are becoming severe enough to determine the survival of company. To survive global competition, each firm must focus on achieving innovation excellence and operational excellence as core competency for sustainable competitive advantage. Supply chain management is now regarded as one of the most effective innovation initiatives to achieve operational excellence, and its importance has become ever more apparent. However, few companies effectively manage their supply chains, and the greatest difficulty is in achieving supply chain visibility. Many companies still suffer from a lack of visibility, and in spite of extensive research and the availability of modern technologies, the concepts and quantification methods to increase supply chain visibility are still ambiguous. Based on the extant researches in supply chain visibility, this study proposes an extended visibility concept focusing on a process capability perspective and suggests a more quantitative model using Z score in Six Sigma methodology to evaluate and improve the level of supply chain visibility.

  20. The visibility of cancer on previous mammograms in retrospective review

    International Nuclear Information System (INIS)

    Saarenmaa, I.; Salminen, T.; Geiger, U.; Heikkinen, P.; Hyvarinen, S.; Isola, J.; Kataja, V.; Kokko, M.-L.; Kokko, R.; Kumpulainen, E.; Karkkainen, A.; Pakkanen, J.; Peltonen, P.; Piironen, A.; Salo, A.; Talviala, M.-L.; Hakama, M.

    2001-01-01

    AIM: To study how many tumours were visible in restrospect on mammograms originally reported as normal or benign in patients coming to surgery with proven breast cancer. The effect of making the pre--operative mammogram available was also assessed. MATERIALS AND METHODS: Three hundred and twenty initial mammograms of consecutive new breast cancer cases were analysed by a group of radiologists in the knowledge that all patients were later diagnosed with breast cancer. The films were read twice, first without and then with the later (pre-operative) mammograms available. The parenchymal density in the location of the tumour was classified as fatty, mixed or dense, and the tumours were classified as visible or not visible. The reasons for the invisibility of the tumour in the earlier examination were analysed. RESULTS: Fourteen per cent (45) of cancers were retrospectively visible in earlier mammograms without the pre-operative mammograms having been shown, and 29% (95) when pre-operative mammograms were shown. Breast parenchymal density decreased with age and the visibility of tumours increased with age. When considered simultaneously, the effect of age (over 55 vs under 55) was greater (OR = 2.9) than the effect of density (fatty vs others) (OR = 1.5). The most common reasons for non-detection were that the lesion was overlooked (55%), diagnosed as benign (33%) or was visible only in one projection (26%). Growing density was the most common (37%) feature of those lesions originally overlooked or regarded as benign. CONCLUSIONS: Tumours are commonly visible in retrospect, but few of them exhibit specific signs of cancer, and are recognized only if they grow or otherwise change. It is not possible to differentiate most of them from normal parenchymal densities. Saaremaa, I. (2001)

  1. Inequality and visibility of wealth in experimental social networks.

    Science.gov (United States)

    Nishi, Akihiro; Shirado, Hirokazu; Rand, David G; Christakis, Nicholas A

    2015-10-15

    Humans prefer relatively equal distributions of resources, yet societies have varying degrees of economic inequality. To investigate some of the possible determinants and consequences of inequality, here we perform experiments involving a networked public goods game in which subjects interact and gain or lose wealth. Subjects (n = 1,462) were randomly assigned to have higher or lower initial endowments, and were embedded within social networks with three levels of economic inequality (Gini coefficient = 0.0, 0.2, and 0.4). In addition, we manipulated the visibility of the wealth of network neighbours. We show that wealth visibility facilitates the downstream consequences of initial inequality-in initially more unequal situations, wealth visibility leads to greater inequality than when wealth is invisible. This result reflects a heterogeneous response to visibility in richer versus poorer subjects. We also find that making wealth visible has adverse welfare consequences, yielding lower levels of overall cooperation, inter-connectedness, and wealth. High initial levels of economic inequality alone, however, have relatively few deleterious welfare effects.

  2. Efficient visibility encoding for dynamic illumination in direct volume rendering.

    Science.gov (United States)

    Kronander, Joel; Jönsson, Daniel; Löw, Joakim; Ljung, Patric; Ynnerman, Anders; Unger, Jonas

    2012-03-01

    We present an algorithm that enables real-time dynamic shading in direct volume rendering using general lighting, including directional lights, point lights, and environment maps. Real-time performance is achieved by encoding local and global volumetric visibility using spherical harmonic (SH) basis functions stored in an efficient multiresolution grid over the extent of the volume. Our method enables high-frequency shadows in the spatial domain, but is limited to a low-frequency approximation of visibility and illumination in the angular domain. In a first pass, level of detail (LOD) selection in the grid is based on the current transfer function setting. This enables rapid online computation and SH projection of the local spherical distribution of visibility information. Using a piecewise integration of the SH coefficients over the local regions, the global visibility within the volume is then computed. By representing the light sources using their SH projections, the integral over lighting, visibility, and isotropic phase functions can be efficiently computed during rendering. The utility of our method is demonstrated in several examples showing the generality and interactive performance of the approach.

  3. Dark/visible parallel universes and Big Bang nucleosynthesis

    International Nuclear Information System (INIS)

    Bertulani, C. A.; Frederico, T.; Fuqua, J.; Hussein, M. S.; Oliveira, O.; Paula, W. de

    2012-01-01

    We develop a model for visible matter-dark matter interaction based on the exchange of a massive gray boson called herein the Mulato. Our model hinges on the assumption that all known particles in the visible matter have their counterparts in the dark matter. We postulate six families of particles five of which are dark. This leads to the unavoidable postulation of six parallel worlds, the visible one and five invisible worlds. A close study of big bang nucleosynthesis (BBN), baryon asymmetries, cosmic microwave background (CMB) bounds, galaxy dynamics, together with the Standard Model assumptions, help us to set a limit on the mass and width of the new gauge boson. Modification of the statistics underlying the kinetic energy distribution of particles during the BBN is also discussed. The changes in reaction rates during the BBN due to a departure from the Debye-Hueckel electron screening model is also investigated.

  4. Microtruss structures with enhanced elasticity fabricated through visible light photocuring

    Directory of Open Access Journals (Sweden)

    Hari Nanthakumar

    Full Text Available We report on the fabrication of an open cellular solid structure using visible light photocuring in combination with light-induced self-writing. A visible light sensitive photopolymer is irradiated with multiple arrays of microscale optical beams, which are generated from LEDs. These beams undergo self-trapping and elicit the inscription of microscale, solid struts into the medium. This process creates a structure consisting of multiple, intersecting struts that form a microtruss structure. Such structures retain their elasticity at higher temperatures as compared to a bulk film of the same thickness. This is the first demonstration of visible light photocuring of photopolymers into a microtruss structure, as well as investigation into their elastic properties under tension. Keywords: Polymers, Self-trapping, Microstructures, Cellular solids

  5. Orbital Angular Momentum Multiplexing over Visible Light Communication Systems

    Science.gov (United States)

    Tripathi, Hardik Rameshchandra

    This thesis proposes and explores the possibility of using Orbital Angular Momentum multiplexing in Visible Light Communication system. Orbital Angular Momentum is mainly applied for laser and optical fiber transmissions, while Visible Light Communication is a technology using the light as a carrier for wireless communication. In this research, the study of the state of art and experiments showing some results on multiplexing based on Orbital Angular Momentum over Visible Light Communication system were done. After completion of the initial stage; research work and simulations were performed on spatial multiplexing over Li-Fi channel modeling. Simulation scenarios which allowed to evaluate the Signal-to-Noise Ratio, Received Power Distribution, Intensity and Illuminance were defined and developed.

  6. High visibility temporal ghost imaging with classical light

    Science.gov (United States)

    Liu, Jianbin; Wang, Jingjing; Chen, Hui; Zheng, Huaibin; Liu, Yanyan; Zhou, Yu; Li, Fu-li; Xu, Zhuo

    2018-03-01

    High visibility temporal ghost imaging with classical light is possible when superbunching pseudothermal light is employed. In the numerical simulation, the visibility of temporal ghost imaging with pseudothermal light, equaling (4 . 7 ± 0 . 2)%, can be increased to (75 ± 8)% in the same scheme with superbunching pseudothermal light. The reasons for that the retrieved images are different for superbunching pseudothermal light with different values of degree of second-order coherence are discussed in detail. It is concluded that high visibility and high quality temporal ghost image can be obtained by collecting sufficient number of data points. The results are helpful to understand the difference between ghost imaging with classical light and entangled photon pairs. The superbunching pseudothermal light can be employed to improve the image quality in ghost imaging applications.

  7. Security in Visible Light Communication: Novel Challenges and Opportunities

    Directory of Open Access Journals (Sweden)

    Christian ROHNER

    2015-09-01

    Full Text Available As LED lighting becomes increasingly ubiquitous, Visible Light Communication is attracting the interest of academia and industry as a complement to RF as the physical layer for the Internet of Things. Aside from its much greater spectral availability compared to RF, visible light has several attractive properties that may promote its uptake: its lack of health risks, its opportunities for spatial reuse, its relative immunity to multipath fading, its lack of electromagnetic interference, and its inherently secure nature: differently from RF, light does not penetrate through walls. In this paper, we outline the security implications of Visible Light Communication, review the existing contributions to this under-explored space, and survey the research opportunities that we envision for the near future.

  8. Robust Adaptive Photon Tracing using Photon Path Visibility

    DEFF Research Database (Denmark)

    Hachisuka, Toshiya; Jensen, Henrik Wann

    2011-01-01

    We present a new adaptive photon tracing algorithm which can handle illumination settings that are considered difficult for photon tracing approaches such as outdoor scenes, close-ups of a small part of an illuminated region, and illumination coming through a small gap. The key contribution in our...... algorithm is the use of visibility of photon path as the importance function which ensures that our sampling algorithm focuses on paths that are visible from the given viewpoint. Our sampling algorithm builds on two recent developments in Markov chain Monte Carlo methods: adaptive Markov chain sampling...... and replica exchange. Using these techniques, each photon path is adaptively mutated and it explores the sampling space efficiently without being stuck at a local peak of the importance function. We have implemented this sampling approach in the progressive photon mapping algorithm which provides visibility...

  9. Young children's tool innovation across culture: Affordance visibility matters.

    Science.gov (United States)

    Neldner, Karri; Mushin, Ilana; Nielsen, Mark

    2017-11-01

    Young children typically demonstrate low rates of tool innovation. However, previous studies have limited children's performance by presenting tools with opaque affordances. In an attempt to scaffold children's understanding of what constitutes an appropriate tool within an innovation task we compared tools in which the focal affordance was visible to those in which it was opaque. To evaluate possible cultural specificity, data collection was undertaken in a Western urban population and a remote Indigenous community. As expected affordance visibility altered innovation rates: young children were more likely to innovate on a tool that had visible affordances than one with concealed affordances. Furthermore, innovation rates were higher than those reported in previous innovation studies. Cultural background did not affect children's rates of tool innovation. It is suggested that new methods for testing tool innovation in children must be developed in order to broaden our knowledge of young children's tool innovation capabilities. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. The Relationship between Social Visibility and CSR Disclosure

    Directory of Open Access Journals (Sweden)

    Waris Ali

    2018-03-01

    Full Text Available The aim of this research is to investigate the link between different proxies of social visibility such as company size, company profitability, environmental sensitivity, and multinational subsidiary with CSR disclosure. This study used a content analysis method to extract CSR-related information from the annual reports of 253 listed companies of Pakistan. The collected data was analyzed through a multiple linear pooled regression analysis technique. The results showed that company size, company profitability, environmental sensitivity, and to be a multinational subsidiary have a significant positive relationship with CSR disclosure. This indicates that different aspects of corporate social visibility are associated with CSR disclosure. We assert that highly socially visible companies, prone to pressures from various actors of the society such as the media, NGOs, the government, and other stakeholders, appear to disclose CSR information to manage relationships with these actors.

  11. Visibility in a pure model of golden spiral phyllotaxis.

    Science.gov (United States)

    Herrmann, Burghard

    2018-07-01

    This paper considers the geometry of plants with golden spiral phyllotaxis, i.e. growing leaf by leaf on a spiral with golden divergence angle, via the simplest mathematical model, a cylinder with regular arrangement of points on its surface. As is well-known, Fibonacci numbers appear by means of the order of parastichies. This fact is shown to be a straightforward application of logical consequences to a particular model with respect to pure visibility. This notion is very similar to that of contact parastichies. The 3-D cylindrical model of golden spiral phyllotaxis abstracts from the form of leaves and identifies them with points. Pure visibility is specified in the 2-D representation so that common sense parastichies can be scrutinized. The main Theorem states that the orders of the purely most visible parastichies are Fibonacci numbers. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. A characterization of horizontal visibility graphs and combinatorics on words

    Science.gov (United States)

    Gutin, Gregory; Mansour, Toufik; Severini, Simone

    2011-06-01

    A Horizontal Visibility Graph (HVG) is defined in association with an ordered set of non-negative reals. HVGs realize a methodology in the analysis of time series, their degree distribution being a good discriminator between randomness and chaos Luque et al. [B. Luque, L. Lacasa, F. Ballesteros, J. Luque, Horizontal visibility graphs: exact results for random time series, Phys. Rev. E 80 (2009), 046103]. We prove that a graph is an HVG if and only if it is outerplanar and has a Hamilton path. Therefore, an HVG is a noncrossing graph, as defined in algebraic combinatorics Flajolet and Noy [P. Flajolet, M. Noy, Analytic combinatorics of noncrossing configurations, Discrete Math., 204 (1999) 203-229]. Our characterization of HVGs implies a linear time recognition algorithm. Treating ordered sets as words, we characterize subfamilies of HVGs highlighting various connections with combinatorial statistics and introducing the notion of a visible pair. With this technique, we determine asymptotically the average number of edges of HVGs.

  13. Development of Visible Light-Responsive Sensitized Photocatalysts

    Directory of Open Access Journals (Sweden)

    Donghua Pei

    2012-01-01

    Full Text Available The paper presents a review of studies about the visible-light-promoted photodegradation of the contaminants and energy conversion with sensitized photocatalysts. Herein we studied mechanism, physical properties, and synergism effect of the sensitized photocatalysts as well as the method for enhancing the photosensitized effect. According to the reported studies in the literature, inorganic sensitizers, organic dyes, and coordination metal complexes were very effective sensitizers that were studied mostly, of which organic dyes photosensitization is the most widely studied modified method. Photosensitization is an important way to extend the excitation wavelength to the visible range, and therefore sensitized photocatalysts play an important role in the development of visible light-responsive photocatalysts for future industrialized applications. This paper mainly describes the types, modification, photocatalytic performance, application, and the developments of photosensitization for environmental application.

  14. THE VISIBLE HAND? THE ECONOMICS OF ALFRED CHANDLER

    Directory of Open Access Journals (Sweden)

    Don Matthews

    2000-01-01

    Full Text Available In his great work The Visible Hand: The Managerial Revolution in American Business, Alfred Chandler argues that the modern managerial enterprise replaced the invisible hand of the market in coordinating the activities and allocating the resources of the U.S. economy. But Chandler’s view of the invisible hand of the market is much too narrow. The modern managerial enterprise is not a substitute for the invisible hand of the market but an integral part of it. The Visible Hand is actually a history of the invisible hand of the market.

  15. Assessing Visibility of Individual Transmission Errors in Networked Video

    DEFF Research Database (Denmark)

    Korhonen, Jari; Mantel, Claire

    2016-01-01

    could benefit from information about subjective visibility of individual packet losses; for example, computational resources could be directed more efficiently to unequal error protection and concealment by focusing in the visually most disturbing artifacts. In this paper, we present a novel subjective...... methodology for packet loss artifact detection by tapping a touchscreen where a defect is observed. To validate the proposed methodology, the results of a pilot study are presented and analyzed. According to the results, the proposed method can be used to derive qualitatively and statistically meaningful data...... on the subjective visibility of individual packet loss artifacts....

  16. Systems and Methods for Automated Water Detection Using Visible Sensors

    Science.gov (United States)

    Rankin, Arturo L. (Inventor); Matthies, Larry H. (Inventor); Bellutta, Paolo (Inventor)

    2016-01-01

    Systems and methods are disclosed that include automated machine vision that can utilize images of scenes captured by a 3D imaging system configured to image light within the visible light spectrum to detect water. One embodiment includes autonomously detecting water bodies within a scene including capturing at least one 3D image of a scene using a sensor system configured to detect visible light and to measure distance from points within the scene to the sensor system, and detecting water within the scene using a processor configured to detect regions within each of the at least one 3D images that possess at least one characteristic indicative of the presence of water.

  17. Visible-light optical coherence tomography: a review

    Science.gov (United States)

    Shu, Xiao; Beckmann, Lisa; Zhang, Hao F.

    2017-12-01

    Visible-light optical coherence tomography (vis-OCT) is an emerging imaging modality, providing new capabilities in both anatomical and functional imaging of biological tissue. It relies on visible light illumination, whereas most commercial and investigational OCTs use near-infrared light. As a result, vis-OCT requires different considerations in engineering design and implementation but brings unique potential benefits to both fundamental research and clinical care of several diseases. Here, we intend to provide a summary of the development of vis-OCT and its demonstrated applications. We also provide perspectives on future technology improvement and applications.

  18. Perceptions of a photograph of a woman with visible piercings.

    Science.gov (United States)

    Martino, Sara

    2008-08-01

    To examine perceptions of people with visible piercings 105 undergraduate students from four different courses on campus (85 women, 20 men; M age=20.0 yr., SD=3.4) were randomly assigned to rate a photograph of a women with or without piercings on her eyebrow, ear, lip, and nose on 13 characteristics. Analysis indicated the model with visible piercings was rated less religious and more creative, artistic, and mysterious. These findings differ from previous findings on perception of tattoos. Implications and directions for research with different age groups are discussed.

  19. Contrast Enhancement in Poor Visibility Conditions Using Guided Filtering

    Directory of Open Access Journals (Sweden)

    D

    2013-06-01

    Full Text Available In this paper, extraction of atmospheric veil is proposed to enhance the contrast of the images captured under poor visibility conditions. The method based on guided filtering can accurately recover hidden edges, maintain structural similarity (SSIM to input image and it is effective for both color and gray level images. The proposed algorithm works without prior information about the scene and its complexity is linear function of the input image size. Experimental comparisons with state of the art algorithms demonstrate that our approach can significantly enhance the contrast and restore the visibility in fine details.

  20. Observation of a visible charmed particle decay in neutrino interactions

    International Nuclear Information System (INIS)

    Cnops, A.M.; Connolly, P.L.; Kahn, S.A.

    1979-01-01

    In a sample of 250 semileptonic charmed particle decays (ν/sub μ/ + Neon → μ - + e + + ... events), one clear event is found where the e + does not come directly from the ν interaction vertex but from a decay point 1.1 cm downstream of the vertex. This event is interpreted as a visible charmed particle decay: into an e + and a positive and a negative charged track. The observation of a visible charm decay in the sample is consistent with what is expected if the charm lifetime were of the order 5 x 10 -13 sec. 5 references

  1. Visibility of gingiva - An important determinant for an esthetic smile.

    Science.gov (United States)

    Sepolia, Shipra; Sepolia, Gaurav; Kaur, Rupinder; Gautam, Devendar Kumar; Jindal, Vikas; Gupta, Subhash Chander

    2014-07-01

    Need for having better esthetics is the new emerging trend seen in patients' demands and expectations. Various periodontal procedures including the mucogingival procedures have been designed to enhance the esthetics. The amount of gingival display of the patient is also an important parameter while considering the esthetics of the patient. Till date, very few studies have been done in which the amount of gingival visibility have been determined. So, the aim of this study was to evaluate the amount of visibility of gingiva during natural smile and forced smile in the patients visiting Himachal Dental College and Hospital. A total of 400 patients (242 females and 158 males), aged between 18 to 49 years, attending the outpatient department of Himachal Dental College, were included in this study. Patients were divided into two groups according to age and gender. Clinical photographs of the patients were taken and analyzed according to the following classification: (1) Very high smile line that is more than 2 mm of marginal gingiva visible or more than 2 mm apical to the cementoenamel junction visible for the reduced but healthy periodontium, (2) high smile line that is between 0 and 2 mm of marginal gingiva visible or between 0 and 2 mm apical to the cementoenamel junction visible for the reduced but healthy periodontium, (3) average smile line in which only gingival embrasures are visible, (4) low smile line in which gingival embrasures and cementoenamel junction not visible. Examination of the gingiva was done for both natural smile and forced smile. During smile analysis, the following results were revealed for Natural smile and forced smile. Natural smile analysis revealed following: C1: 1%, C2: 6%, C3: 43.50% and C4 was 49.50%. Forced smile analysis revealed the following: C1: 1%, C2: 15.50%, C3: 59% and C4: 24.50%. Excessive gingival display is an esthetic concern both to the patient and clinician. Therefore, understanding the etiology and treatment options is

  2. Visibility of gingiva - An important determinant for an esthetic smile

    Directory of Open Access Journals (Sweden)

    Shipra Sepolia

    2014-01-01

    Full Text Available Background: Need for having better esthetics is the new emerging trend seen in patients′ demands and expectations. Various periodontal procedures including the mucogingival procedures have been designed to enhance the esthetics. The amount of gingival display of the patient is also an important parameter while considering the esthetics of the patient. Till date, very few studies have been done in which the amount of gingival visibility have been determined. So, the aim of this study was to evaluate the amount of visibility of gingiva during natural smile and forced smile in the patients visiting Himachal Dental College and Hospital. Materials and Methods: A total of 400 patients (242 females and 158 males, aged between 18 to 49 years, attending the outpatient department of Himachal Dental College, were included in this study. Patients were divided into two groups according to age and gender. Clinical photographs of the patients were taken and analyzed according to the following classification: (1 Very high smile line that is more than 2 mm of marginal gingiva visible or more than 2 mm apical to the cementoenamel junction visible for the reduced but healthy periodontium, (2 high smile line that is between 0 and 2 mm of marginal gingiva visible or between 0 and 2 mm apical to the cementoenamel junction visible for the reduced but healthy periodontium, (3 average smile line in which only gingival embrasures are visible, (4 low smile line in which gingival embrasures and cementoenamel junction not visible. Examination of the gingiva was done for both natural smile and forced smile. Results: During smile analysis, the following results were revealed for Natural smile and forced smile. Natural smile analysis revealed following: C1: 1%, C2: 6%, C3: 43.50% and C4 was 49.50%. Forced smile analysis revealed the following: C1: 1%, C2: 15.50%, C3: 59% and C4: 24.50%. Conclusions: Excessive gingival display is an esthetic concern both to the patient and

  3. 40 CFR 51.305 - Monitoring for reasonably attributable visibility impairment.

    Science.gov (United States)

    2010-07-01

    ... visibility impairment. 51.305 Section 51.305 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Protection of Visibility § 51.305 Monitoring for reasonably attributable visibility impairment. (a) For the purposes of addressing reasonably attributable visibility impairment, each State containing a mandatory...

  4. Making the Invisible Visible: A Methodological and a Substantive Issue

    Science.gov (United States)

    Dagley, Valerie

    2004-01-01

    This article discusses the issue of "making the invisible visible" from a methodological and a substantive viewpoint. The ideas emerged from a doctoral research study into individual target setting with middle ability students in an English secondary school. The students involved had been identified by assessments as "average"…

  5. (meth)acrylates on in situ visible light polymerization of ...

    Indian Academy of Sciences (India)

    60

    ... faster to be cured using a visible light source with a Tungsten-Halogen lamp ... ranging from 350 to 1100 nm, which even covers some UV and near IR region. .... incorporation of the acid-containing and/or acrylate-containing monomer led to.

  6. Making Practice Visible through Writing for Professional Publication

    Science.gov (United States)

    Roberts, Sherron Killingsworth

    2016-01-01

    Why should educators and service professionals bother writing for professional publication? Experienced editor, Sherron Roberts says writing for professional publication allows educators to share their work and make their practice visible. Any educator is quite capable of writing for a professional publication. This article is intended to show…

  7. Using Polarization features of visible light for automatic landmine detection

    NARCIS (Netherlands)

    Jong, W. de; Schavemaker, J.G.M.

    2007-01-01

    This chapter describes the usage of polarization features of visible light for automatic landmine detection. The first section gives an introduction to land-mine detection and the usage of camera systems. In section 2 detection concepts and methods that use polarization features are described.

  8. Visibility of Diversity within Association of Research Libraries Websites

    Science.gov (United States)

    Mestre, Lori S.

    2011-01-01

    Libraries in the United States have worked towards developing more inclusive environments and programs. This inclusiveness should also extend to the online library presence. This article provides results of a web page scan of all Association of Research Libraries (ARL) in the United States to document the visibility of diversity on their pages. A…

  9. Effect of visible range electromagnetic radiations on Escherichia coli ...

    African Journals Online (AJOL)

    Background: Escherichia coli is the agent responsible for a range of clinical diseases. With emerging antimicrobial resistance, other treatment options including solar/photo-therapy are becoming increasingly common. Visible Range Radiation Therapy/Colour Therapy is an emerging technique in the field of ...

  10. Thermal-Polarimetric and Visible Data Collection for Face Recognition

    Science.gov (United States)

    2016-09-01

    matching a thermal face image with visible spectrum face images for interoperability with existing biometric face databases and watch lists. One of the...Byrd KA Preview of the newly acquired NVESD-ARL multimodal face database. Proc SPIE DSS. 2013;8734. 10. Yuffa AJ, Gurton KP, Videen G. Appl Optics

  11. Characterizing supply chain visibility – A literature review

    NARCIS (Netherlands)

    Somapa, Sirirat; Cools, Martine; Dullaert, Wout

    2018-01-01

    Purpose – The purpose of this paper is to present a literature review that aims to provide insight into the characteristics and effectiveness of supply chain visibility (SCV), as well as to identify metrics that capture these aspects in business processes. Design/methodology/approach – A systematic

  12. The Management of Visibilities in the Digital Age

    DEFF Research Database (Denmark)

    Flyverbom, Mikkel; Leonardi, Paul; Stohl, Cynthia

    2016-01-01

    What we see, what we show and how we look are fundamental organizational concerns made ever more salient by the affordances, dynamics, and discourses of the digital age. Contemporary organizing practices are awash with material, mediated and managed visibilities: companies erect glass buildings...

  13. Improved spring model-based collaborative indoor visible light positioning

    Science.gov (United States)

    Luo, Zhijie; Zhang, WeiNan; Zhou, GuoFu

    2016-06-01

    Gaining accuracy with indoor positioning of individuals is important as many location-based services rely on the user's current position to provide them with useful services. Many researchers have studied indoor positioning techniques based on WiFi and Bluetooth. However, they have disadvantages such as low accuracy or high cost. In this paper, we propose an indoor positioning system in which visible light radiated from light-emitting diodes is used to locate the position of receivers. Compared with existing methods using light-emitting diode light, we present a high-precision and simple implementation collaborative indoor visible light positioning system based on an improved spring model. We first estimate coordinate position information using the visible light positioning system, and then use the spring model to correct positioning errors. The system can be employed easily because it does not require additional sensors and the occlusion problem of visible light would be alleviated. We also describe simulation experiments, which confirm the feasibility of our proposed method.

  14. Visibility and anonymity effects on attraction and group cohesiveness

    NARCIS (Netherlands)

    Lea, Martin; Spears, Russell; Watt, Susan E.

    2007-01-01

    This study investigated attraction and group cohesiveness under different visibility and anonymity conditions for social categories that differed in their capacity to be visually cued. Using computer-mediated communication in 36 mixed gender (visually cued category) and nationality (non-visually

  15. Analysis of visible spectral lines in LHD helium discharge

    International Nuclear Information System (INIS)

    Wan, B.N.; Goto, M.; Morita, S.

    1999-06-01

    In this study, visible spectral lines in LHD helium discharges are analyzed and it was found that they could be well fitted with gaussian profile. The results reveal a simple mechanism of helium atom recycling. Ion temperatures were also derived from the fitting. A typical value of the ion temperature obtained was about 6 eV. (author)

  16. Mis asi on OÜ Visible Solutions? / Indrek Grigor

    Index Scriptorium Estoniae

    Grigor, Indrek

    2011-01-01

    Kunstiteos-ettevõtte OÜ Visible Solutions (juhatus: Sigrid Viir, Taaniel Raudsepp, Karel Koplimets) näitus "Adam Smithi Lemmik Nähtamatu Käsi Puuris" Tartu Kunstimajas 18. dets.-ni 2011. Kunstiprojekt firmast, mille tegevuse objekt on loomemajanduse kritiseerimine, mida tehakse viimase toimeloogika kunstiväljal eksponeerimise abil

  17. Prediction of fog/visibility over India using NWP Model

    Indian Academy of Sciences (India)

    Aditi Singh

    2018-03-06

    Mar 6, 2018 ... National Centre for Medium Range Weather Forecasting, Earth System Science Organization, Ministry of Earth. Sciences, Noida ..... ing water. For a given relative humidity, the aerosol content fixed according to cleaner conditions in the model gives higher values of visibility as com- pared to the polluted ...

  18. A titanium nitride based metamaterial for applications in the visible

    DEFF Research Database (Denmark)

    Naik, Gururaj V.; Saha, Bivas; Liu, Jing

    2013-01-01

    Epitaxially grown TiN/Al0.6Sc0.4N superlattice behaves as a hyperbolic metamaterial (HMM) in the visible range. Since HMMs enhance photonic-density-of-states and reduce lifetime of an emitter, we observed nine times decrease in lifetime of a dye molecule placed close to this HMM. © 2013 The Optic...

  19. Integrated Visible Photonics for Trapped-Ion Quantum Computing

    Science.gov (United States)

    2017-06-10

    etch to provide a smooth oxide facet, and clearance for fiber positioning for edge input coupling. Integrated Visible Photonics for Trapped-Ion...capability to optically address individual ions at several wavelengths. We demonstrate a dual-layered silicon nitride photonic platform for integration...coherence times, strong coulomb interactions, and optical addressability, hold great promise for implementation of practical quantum information

  20. Low level cloud motion vectors from Kalpana-1 visible images

    Indian Academy of Sciences (India)

    . In this paper, an attempt has been made to retrieve low-level cloud motion vectors using Kalpana-1 visible (VIS) images at every half an hour. The VIS channel provides better detection of low level clouds, which remain obscure in thermal IR ...

  1. 40 CFR 52.26 - Visibility monitoring strategy.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Visibility monitoring strategy. 52.26 Section 52.26 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... monitoring strategy. (a) Plan Disapprovals. The provisions of this section are applicable to any State...

  2. Publish or perish: remaining academically relevant and visible in the ...

    African Journals Online (AJOL)

    To improve the visibility of scholars' works and make them relevant on the academic scene, electronic publishing will be advisable. This provides the potential to readers to search and locate the ar ticles at minimum time within one journal or across multiple journals. This includes publishing articles in journals that are ...

  3. Visible photocatalytic properties of vanadium doped zinc oxide aerogel nanopowder

    Energy Technology Data Exchange (ETDEWEB)

    Slama, R. [Laboratoire de Physique des Materiaux et des Nanomateriaux appliquee a l' Environnement, Faculte des Sciences de Gabes, Universite de Gabes, Cite Erriadh Manara Zrig, 6072 Gabes (Tunisia); Unite de Recherche Environnement, Catalyse et Analyse des procedes URECAP (UR/99/11-20), Ecole Nationale d' Ingenieurs de Gabes, Universite de Gabes, Route de Medenine 6029 Gabes (Tunisia); Ghribi, F. [Laboratoire de Physique des Materiaux et des Nanomateriaux appliquee a l' Environnement, Faculte des Sciences de Gabes, Universite de Gabes, Cite Erriadh Manara Zrig, 6072 Gabes (Tunisia); Houas, A. [Unite de Recherche Environnement, Catalyse et Analyse des procedes URECAP (UR/99/11-20), Ecole Nationale d' Ingenieurs de Gabes, Universite de Gabes, Route de Medenine 6029 Gabes (Tunisia); Barthou, C. [Institut des NanoSciences de Paris (INSP), UPMC Universite Paris 6, CNRS UMR 7588, 140 rue de Lourmel, F-75015 Paris France (France); El Mir, L., E-mail: Lassaad.ElMir@fsg.rnu.tn [Laboratoire de Physique des Materiaux et des Nanomateriaux appliquee a l' Environnement, Faculte des Sciences de Gabes, Universite de Gabes, Cite Erriadh Manara Zrig, 6072 Gabes (Tunisia); College of Sciences, Department of Physics, Al-Imam Muhammad Ibn Saud University, Riyadh 11623 (Saudi Arabia)

    2011-06-30

    Vanadium-doped zinc oxide nanoparticles have been synthesized by sol-gel method. In our approach the water for hydrolysis used in the synthesis of nanopowder was slowly released followed by a thermal drying in ethyl alcohol at 250 deg. C. The obtained nanopowder was characterized by various techniques such as particle size analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and photoluminescence (PL). In the as-prepared state, the powder with an average particle size of 25 nm presents a strong luminescence band in the visible range. From photoluminescence excitation (PLE) the energy position of the obtained PL band depends on the excitation wavelength and this PL band can be also observed under visible excitations. This result is very promising for visible photo catalysis applications, which was confirmed by methylene blue photo-degradation using visible lamp as a light source. - Research Highlights: > We explore the impact of plot size on estimation of a small watershed outputs. > Different lengths and fixed width plots were installed on two slope aspects. > The performance of two similar sets of experimental plots was examined. > The optimal lengths for estimation of sediment and runoff were finally found.

  4. Two-way visible light communication and illumination with LEDs

    NARCIS (Netherlands)

    Li, S.; Pandharipande, A.; Willems, F.M.J.

    2017-01-01

    Visible light communications (VLC) with light-emitting diodes (LEDs) has attracted applications, such as data communications, lighting control, and light interaction. In this paper, we propose a system by which two LED devices are used for two-way VLC while also providing illumination. We consider

  5. Large Scale Scanning Probe Microscope "Making Shear Force Scanning visible."

    NARCIS (Netherlands)

    Bosma, E.; Offerhaus, Herman L.; van der Veen, Jan T.; van der Veen, J.T.; Segerink, Franciscus B.; Wessel, I.M.

    2010-01-01

    We describe a demonstration of a scanning probe microscope with shear-force tuning fork feedback. The tuning fork is several centimeters long, and the rigid fiber is replaced by a toothpick. By scaling this demonstration to visible dimensions the accessibility of shear-force scanning and tuning fork

  6. Hybrid bilayer plasmonic metasurface efficiently manipulates visible light

    Science.gov (United States)

    Qin, Fei; Ding, Lu; Zhang, Lei; Monticone, Francesco; Chum, Chan Choy; Deng, Jie; Mei, Shengtao; Li, Ying; Teng, Jinghua; Hong, Minghui; Zhang, Shuang; Alù, Andrea; Qiu, Cheng-Wei

    2016-01-01

    Metasurfaces operating in the cross-polarization scheme have shown an interesting degree of control over the wavefront of transmitted light. Nevertheless, their inherently low efficiency in visible light raises certain concerns for practical applications. Without sacrificing the ultrathin flat design, we propose a bilayer plasmonic metasurface operating at visible frequencies, obtained by coupling a nanoantenna-based metasurface with its complementary Babinet-inverted copy. By breaking the radiation symmetry because of the finite, yet small, thickness of the proposed structure and benefitting from properly tailored intra- and interlayer couplings, such coupled bilayer metasurface experimentally yields a conversion efficiency of 17%, significantly larger than that of earlier single-layer designs, as well as an extinction ratio larger than 0 dB, meaning that anomalous refraction dominates the transmission response. Our finding shows that metallic metasurface can counterintuitively manipulate the visible light as efficiently as dielectric metasurface (~20% in conversion efficiency in Lin et al.’s study), although the metal’s ohmic loss is much higher than dielectrics. Our hybrid bilayer design, still being ultrathin (~λ/6), is found to obey generalized Snell’s law even in the presence of strong couplings. It is capable of efficiently manipulating visible light over a broad bandwidth and can be realized with a facile one-step nanofabrication process. PMID:26767195

  7. Characterization and mechanism analysis of N doped TiO2 with visible light response and its enhanced visible activity

    International Nuclear Information System (INIS)

    Cheng Xiuwen; Yu Xiujuan; Xing Zipeng

    2012-01-01

    Nitrogen doped TiO 2 nanoparticles were synthesized through a hydrolysis-precipitation process using ammonia water as the doping species. The resulting materials were characterized by XRD, DRS, SPS, XPS and FT-IR. Further, the activity enhanced-mechanism was discussed in detail. XRD results showed that doping with nitrogen could effectively retard the phase transformation of TiO 2 from anatase to rutile and increase the anatase crystallinity. DRS and SPS results indicated that the light absorbance edge of nitrogen doped TiO 2 nanoparticle was obviously red-shifted to visible light region and the separation rates of photogenerated charge carriers were greatly improved, respectively. XPS and FT-IR analysis implied that the contents of surface hydroxyl groups were improved significantly and the VBM (valance bond maximum) of O2p was 2.3 eV. Under the visible light irradiation with 120 min, a 65.3% degradation rate of phenol could be achieved. The photocatalytic activity of nitrogen doped TiO 2 was 2.08 and 1.97 times than that of pure TiO 2 and P25 TiO 2 , respectively. The enhanced visible light activity was attributed to the well anatase crystallinity, small crystallite size, intense light absorbance edge in visible region, more content of surface hydroxyl groups and high separation efficiency of photogenerated charge carriers.

  8. Visibility of lunar surface features - Apollo 14 orbital observations and lunar landing.

    Science.gov (United States)

    Ziedman, K.

    1972-01-01

    Description of an in-flight visibility test conducted during the Apollo 14 mission for the purpose of validating and extending the mathematical visibility models used previously in the course of the Apollo program to examine the constraints on descent operations imposed by lunar visibility limitations. Following a background review of the effects on mission planning of the visibility limitations due to downsun lunar surface detail 'washout' and a discussion of the visibility prediction techniques previously used for studying lunar visibility problems, the visibility test rationale and procedures are defined and the test results presented. The results appear to confirm the validity of the visibility prediction techniques employed in lunar visibility problem studies. These results provide also a basis for improving the accuracy of the prediction techniques by appropriate modifications.

  9. Visibility graph approach to the analysis of ocean tidal records

    International Nuclear Information System (INIS)

    Telesca, Luciano; Lovallo, Michele; Pierini, Jorge O.

    2012-01-01

    By using the recent method of the visibility graph, three time series of oceanic tide level in central Argentina were investigated. The degree distributions show a rich structure; in particular the maximum is due to the main periodic oscillations at 24 hours and 12 hours and higher harmonics. The degree distributions of the residuals (obtained removing from the original signals the cyclic components) suggest that the local effects, linked with the particular coastal conditions of the sites, are discernible for the degree k 100. Although a relationship between the spectral exponent α and the exponent of the degree distribution γ of tidal signals can be recognized, this cannot be simply stated due to the very rich and complex structure of time dynamics of tides. The present study, even if still preliminary, show the importance of the visibility graph method in investigating the complex time dynamics of observational and experimental signals.

  10. Rechargeable solid state neutron detector and visible radiation indicator

    Science.gov (United States)

    Stowe, Ashley C.; Wiggins, Brenden; Burger, Arnold

    2017-05-23

    A radiation detection device, including: a support structure; and a chalcopyrite crystal coupled to the support structure; wherein, when the chalcopyrite crystal is exposed to radiation, a visible spectrum of the chalcopyrite crystal changes from an initial color to a modified color. The visible spectrum of the chalcopyrite crystal is changed back from the modified color to the initial color by annealing the chalcopyrite crystal at an elevated temperature below a melting point of the chalcopyrite crystal over time. The chalcopyrite crystal is optionally a .sup.6LiInSe.sub.2 crystal. The radiation is comprised of neutrons that decrease the .sup.6Li concentration of the chalcopyrite crystal via a .sup.6Li(n,.alpha.) reaction. The initial color is yellow and the modified color is one of orange and red. The annealing temperature is between about 450 degrees C. and about 650 degrees C. and the annealing time is between about 12 hrs and about 36 hrs.

  11. Simulating Visibility Under Reduced Acuity and Contrast Sensitivity

    Science.gov (United States)

    Thompson, William B.; Legge, Gordon E.; Kersten, Daniel J.; Shakespeare, Robert A.; Lei, Quan

    2017-01-01

    Architects and lighting designers have difficulty designing spaces that are accessible to those with low vision, since the complex nature of most architectural spaces requires a site-specific analysis of the visibility of mobility hazards and key landmarks needed for navigation. We describe a method that can be utilized in the architectural design process for simulating the effects of reduced acuity and contrast on visibility. The key contribution is the development of a way to parameterize the simulation using standard clinical measures of acuity and contrast sensitivity. While these measures are known to be imperfect predictors of visual function, they provide a way of characterizing general levels of visual performance that is familiar to both those working in low vision and our target end-users in the architectural and lighting design communities. We validate the simulation using a letter recognition task. PMID:28375328

  12. Does a Graphical Abstract Bring More Visibility to Your Paper?

    Science.gov (United States)

    Pferschy-Wenzig, Eva-Maria; Pferschy, Ulrich; Wang, Dongdong; Mocan, Andrei; Atanasov, Atanas G

    2016-09-18

    A graphical abstract (GA) represents a piece of artwork that is intended to summarize the main findings of an article for readers at a single glance. Many publishers currently encourage authors to supplement their articles with GAs, in the hope that such a convenient visual summary will facilitate readers with a clearer outline of papers that are of interest and will result in improved overall visibility of the respective publication. To test this assumption, we statistically compared publications with or without GA published in Molecules between March 2014 and March 2015 with regard to several output parameters reflecting visibility. Contrary to our expectations, manuscripts published without GA performed significantly better in terms of PDF downloads, abstract views, and total citations than manuscripts with GA. To the best of our knowledge, this is the first empirical study on the effectiveness of GA for attracting attention to scientific publications.

  13. Visibility bound caused by a distinguishable noise particle

    International Nuclear Information System (INIS)

    Gavenda, Miroslav; Celechovska, Lucie; Dusek, Miloslav; Filip, Radim; Soubusta, Jan

    2011-01-01

    We investigate how the distinguishability of a 'noise' particle degrades interference of the 'signal' particle. The signal, represented by an equatorial state of a photonic qubit, is mixed with noise, represented by another photonic qubit, via linear coupling on a beam splitter. We report on the degradation of the signal photon interference depending on the degree of indistinguishability between the signal and noise photons. When the photons are completely distinguishable in principle but technically indistinguishable, the visibility drops to the value 1/√(2). As the photons become more indistinguishable, the maximal visibility increases and reaches the unit value for completely indistinguishable photons. We have examined this effect experimentally using a setup with a fiber-optics two-photon Mach-Zehnder interferometer.

  14. 1H NMR visibility of mammalian glycogen in solution

    International Nuclear Information System (INIS)

    Zang, L.H.; Rothman, D.L.; Shulman, R.G.

    1990-01-01

    High-resolution 1 H NMR spectra of rabbit liver glycogen in 2 H 2 O were obtained at 500 MHz, and several resonances were assigned by comparison with the chemical shifts of α-linked diglucose molecules. The NMR relaxation times T 1 and T 2 of glycogen in 2 H 2 O were determined to be 1.1 and 0.029 s, respectively. The measured natural linewidth of the carbon-1 proton is in excellent agreement with that calculated from T 2 . The visibility measurements made by digesting glycogen and comparing glucose and glycogen signal intensities demonstrate that in spite of the very high molecular weight, all of the proton nuclei in glycogen contribute to the NMR spectrum. The result is not unexpected, since 100% NMR visibility was previously observed from the carbon nuclei of glycogen, due to the rapid intramolecular motions

  15. Indoor visible light communication with smart lighting technology

    Science.gov (United States)

    Das Barman, Abhirup; Halder, Alak

    2017-02-01

    An indoor visible-light communication performance is investigated utilizing energy efficient white light by 2D LED arrays. Enabled by recent advances in LED technology, IEEE 802.15.7 standardizes high-data-rate visible light communication and advocates for colour shift keying (CSK) modulation to overcome flicker and to support dimming. Voronoi segmentation is employed for decoding N-CSK constellation which has superior performance compared to other existing decoding methods. The two chief performance degrading effects of inter-symbol interference and LED nonlinearity is jointly mitigated using LMS post equalization at the receiver which improves the symbol error rate performance and increases field of view of the receiver. It is found that LMS post equalization symbol at 250MHz offers 7dB SNR improvement at SER10-6

  16. Switching Diarylethenes Reliably in Both Directions with Visible Light.

    Science.gov (United States)

    Fredrich, Sebastian; Göstl, Robert; Herder, Martin; Grubert, Lutz; Hecht, Stefan

    2016-01-18

    A diarylethene photoswitch was covalently connected to two small triplet sensitizer moieties in a conjugated and nonconjugated fashion and the photochromic performance of the resulting compounds was investigated. In comparison with the parent diarylethene (without sensitizers) and one featuring saturated linkages, the conjugated photoswitch offers superior fatigue resistance upon visible-light excitation due to effective triplet energy transfer from the biacetyl termini to the diarylethene core. Our design makes it possible to switch diarylethenes with visible light in both directions in a highly efficient and robust fashion based on extending π-conjugation and by-product-free ring-closure via the triplet manifold. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Does a Graphical Abstract Bring More Visibility to Your Paper?

    Directory of Open Access Journals (Sweden)

    Eva-Maria Pferschy-Wenzig

    2016-09-01

    Full Text Available A graphical abstract (GA represents a piece of artwork that is intended to summarize the main findings of an article for readers at a single glance. Many publishers currently encourage authors to supplement their articles with GAs, in the hope that such a convenient visual summary will facilitate readers with a clearer outline of papers that are of interest and will result in improved overall visibility of the respective publication. To test this assumption, we statistically compared publications with or without GA published in Molecules between March 2014 and March 2015 with regard to several output parameters reflecting visibility. Contrary to our expectations, manuscripts published without GA performed significantly better in terms of PDF downloads, abstract views, and total citations than manuscripts with GA. To the best of our knowledge, this is the first empirical study on the effectiveness of GA for attracting attention to scientific publications.

  18. Rapid Prototyping of Standard Compliant Visible Light Communications System

    OpenAIRE

    Gavrincea, Ciprian; Baranda, Jorge; Henarejos, Pol

    2014-01-01

    This article describes the implementation of a prototype visible light communications system based on the IEEE 802.15.7 standard using low-cost commercial off-the-shelf analog devices. The aim of this article is to show that this standard provides a framework that could promote the introduction of applications into the market. Thus, these specifications could be further developed, reducing the gap between the industry and research communities. The implemented prototype makes use of software d...

  19. Uranium plasma emission coefficient in the visible and near UV.

    Science.gov (United States)

    Mack, J. M., Jr.; Usher, J. L.; Schneider, R. T.; Campbell, H. D.

    1971-01-01

    Measurements of the specific emission coefficient in the near ultra-violet and visible region of a uranium arc plasma are reported. Spatial unfolding of the intensity profile is used to determine the emission coefficient in the spectral range of 2000 A to 6000 A. The uranium partial pressure is estimated to range between .001 and .01 atmosphere, and the corresponding temperature range is 5000 - 10,000 K.

  20. A New and Inexpensive Pyranometer for the Visible Spectral Range

    OpenAIRE

    Martínez, Miguel A.; Andújar, José M.; Enrique, Juan M.

    2009-01-01

    This paper presents the design, construction and testing of a new photodiode-based pyranometer for the visible spectral range (approx. 400 to 750 nm), whose principal characteristics are: accuracy, ease of connection, immunity to noise, remote programming and operation, interior temperature regulation, cosine error minimisation and all this at a very low cost, tens of times lower than that of commercial thermopile-based devices. This new photodiode-based pyranometer overcomes traditional prob...

  1. Advanced supply chains: Visibility, blockchain and human behaviour

    OpenAIRE

    Kharlamov, A.; Parry, G.

    2017-01-01

    Technological advances over the last decade saw the rise of ICT and IoT, paving the way for the Supply Chain of Things. Blockchain technology was one of the most recent and potentially most significant developments. Blockchain technology are secure by design and can enable decentralization and visibility, with application in cryptocurrency transactions, historical records, identity management, traceability, authentication, and many others. However, successful adoption of such technology requi...

  2. Benefit of infrared images in visibility appreciation for fog conditions

    Science.gov (United States)

    Boucher, V.; Dumoulin, J.; Marchetti, M.

    2012-04-01

    Fog situations induce an increase in both accident probability and severity. They constitue a significant part in accident rate. There is very few means to forecast fog, nor to appreciate its density, and its associated visibility decrease. An approach consists in developing on-board tools to qualify and to quantify the fog, and to improve the visibility within each vehicle. Infrared technology is now more common, so solutions based on this specific spectral band could be considered. LW infrared has demonstrated its value in the case of passenger cars. Its use could be discussed too, in particular in the case of obstacles detection. The study presented here deals mainly with the extraction of a visbility distance from LW thermal images in the presence of fog. A French facility in Clermont-Ferrand allows the generation of fog. It can be generated in day or night conditions. The facility is 30 m long, for a 220 m3 volume. The fog is generated spraying water micro droplets, which size is controlled and measured. Experimental conditions could be adapted through water pressure, water nature as an example. Visibility is appreciated with a device measuring light transmission. In the case of infrared, visibility is obtained through the definition of contrast of an object on a given background. On such a basis, infrared spectral band provides a factor 2 benefit on a conventional roadsign, and of a factor 4 in the case of a heated one, with meteorological visibilty of 20 m. Some theoritical aspects will be described, along with a description of the whole experimental setup.

  3. Infrared and Visible links for medical Body Sensor Networks

    OpenAIRE

    Lebas , C; Sahuguede , S; Julien-Vergonjanne , A; Combeau , P; Aveneau , L

    2018-01-01

    International audience; — Our previous studies focused on channel simulation and performance evaluation of optical wireless links for medical body sensor networks. This allowed us to increase our expertise in this field and to propose here a full optical wireless bidirectional system named as LiFi communication system for medical monitoring applications. The full duplex bidirectional communication is based on an infrared uplink and visible downlink. The studied scenario considers a patient we...

  4. Photooxidative damage to mammalian cells and proteins by visible light

    International Nuclear Information System (INIS)

    Packer, L.; Kellogg, E.W. III

    1980-01-01

    In the present article, studies carried out in our laboratory on the effects of visible irradiation and O 2 in a variety of target systems ranging from cultured mammalian cells to purified catalase are reviewed. We will relate these studies of photooxidative damage to a scheme for the propagation of intracellular damage which traces a number of the possible pro-oxidant and anti-oxidant pathways found in the cell

  5. More Speed, More Color, More Visibility, More Chemistry, More Fun!

    Science.gov (United States)

    Compton, Neville

    2017-01-01

    More competitive than ever: Chemistry-A European Journal now offers Accepted Article options for more speed, free color for more distinction, and more engagement with the scientific community through social media for more visibility. In addition, to cater for the growing number of excellent submissions, the journal will publish 72 issues over the coming year. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. PULSAR.MAKING VISIBLE THE SOUND OF STARS

    OpenAIRE

    Lega, Ferran

    2015-01-01

    [EN] Pulsar, making visible the sound of stars is a comunication based on a sound Installation raised as a site-specific project to show the hidden abilities of sound to generate images and patterns on the matter, using the acoustic science of cymatics. The objective of this communication will show people how through abstract and intangible sounds from celestial orbs of cosmos (radio waves generated by electromagnetic pulses from the rotation of neutrón stars), we can create ar...

  7. Visible light alters yeast metabolic rhythms by inhibiting respiration

    OpenAIRE

    Robertson, James Brian; Davis, Chris R.; Johnson, Carl Hirschie

    2013-01-01

    In some organisms, respiration fluctuates cyclically, and these rhythms can be a sensitive gauge of metabolism. Constant or pulsatile exposure of yeast to visible wavelengths of light significantly alters and/or initiates these respiratory oscillations, revealing a further dimension of the challenges to yeast living in natural environments. Our results also have implications for the use of light as research tools—e.g., for excitation of fluorescence microscopically—even in organisms such as y...

  8. Researching in education findings visibility: How Cubans are doing?

    Directory of Open Access Journals (Sweden)

    Torres, Paúl A.

    2012-07-01

    Full Text Available The paper presents an analysis of Cuban educational research visibility by considering international ranking positioning of intellectual production in the field of education. A case study is conducted with outstanding Cuban educational researchers comparing their results with other prestigious professionals in the continent. Finally, new basic resources are proposed and explained for improving Bibliometric indicators by taking advantage of Google Scholar potentials in favoring international ranking positioning.

  9. Optical Non-Orthogonal Multiple Access for Visible Light Communication

    OpenAIRE

    Marshoud, Hanaa; Muhaidat, Sami; Sofotasios, Paschalis C.; Hussain, Sajjad; Imran, Muhammad Ali; Sharif, Bayan S.

    2017-01-01

    The proliferation of mobile Internet and connected devices, offering a variety of services at different levels of performance, represents a major challenge for the fifth generation wireless networks and beyond. This requires a paradigm shift towards the development of key enabling techniques for the next generation wireless networks. In this respect, visible light communication (VLC) has recently emerged as a new communication paradigm that is capable of providing ubiquitous connectivity by c...

  10. Visible light communication: Applications, architecture, standardization and research challenges

    OpenAIRE

    Khan, Latif Ullah

    2016-01-01

    The Radio Frequency (RF) communication suffers from interference and high latency issues. Along with this, RF communication requires a separate setup for transmission and reception of RF waves. Overcoming the above limitations, Visible Light Communication (VLC) is a preferred communication technique because of its high bandwidth and immunity to interference from electromagnetic sources. The revolution in the field of solid state lighting leads to the replacement of florescent lamps by Light E...

  11. El desarrollo de las emociones haciendo el pensamiento visible

    OpenAIRE

    Cascales Ribera, María del Carmen

    2016-01-01

    El presente Trabajo Final de Grado (TFG) permite desarrollar la competencia emocional del alumnado de Educación Primaria haciendo el pensamiento visible a través de rutinas de pensamiento. El presente TFG presenta un programa de actividades educativas relativas al área de educación emocional, que permite manejar las propias emociones, reconocer las emociones en los demás y establecer relaciones. Educación Psicología

  12. An Adaptive and Hybrid Approach for Revisiting the Visibility Pipeline

    Directory of Open Access Journals (Sweden)

    Ícaro Lins Leitão da Cunha

    2016-04-01

    Full Text Available We revisit the visibility problem, which is traditionally known in Computer Graphics and Vision fields as the process of computing a (potentially visible set of primitives in the computational model of a scene. We propose a hybrid solution that uses a dry structure (in the sense of data reduction, a triangulation of the type J1a, to accelerate the task of searching for visible primitives. We came up with a solution that is useful for real-time, on-line, interactive applications as 3D visualization. In such applications the main goal is to load the minimum amount of primitives from the scene during the rendering stage, as possible. For this purpose, our algorithm executes the culling by using a hybrid paradigm based on viewing-frustum, back-face culling and occlusion models. Results have shown substantial improvement over these traditional approaches if applied separately. This novel approach can be used in devices with no dedicated processors or with low processing power, as cell phones or embedded displays, or to visualize data through the Internet, as in virtual museums applications.

  13. Online Journals: the Path Towards Visibility and Quality

    Directory of Open Access Journals (Sweden)

    Julie Walker

    2010-02-01

    Full Text Available Increasing the visibility of a journal is the key to increasing quality. The International Network for the Availability of Scientific Publications works with journal editors in the global South to publish their journals online and to increase the efficiency of the peer review process. Editors are trained in using the Open Journals System software and in online journal management and strategy so they have the tools and knowledge needed to initiate a ‘virtuous cycle' in which visibility leads to an increase in the number and quality of submissions and in turn, increased citations and impact. In order to maximise this increase in quality, it must be supported by strong editorial office processes and management. This article describes some of the issues and strategies faced by the editors INASP works with, placing a particular emphasis on Nepal Journals Online. Key words: INASP; Open Journals System; Journals Online Projects; Nepal Journals Online; journal visibility; peer review DOI: 10.3126/dsaj.v3i0.2786 Dhaulagiri Journal of Sociology and Anthropology Vol.3 2009 175-184

  14. Vehicular Visible Light Networks for Urban Mobile Crowd Sensing

    Directory of Open Access Journals (Sweden)

    Barbara M. Masini

    2018-04-01

    Full Text Available Crowd sensing is a powerful tool to map and predict interests and events. In the future, it could be boosted by an increasing number of connected vehicles sharing information and intentions. This will be made available by on board wireless connected devices able to continuously communicate with other vehicles and with the environment. Among the enabling technologies, visible light communication (VLC represents a low cost solution in the short term. In spite of the fact that vehicular communications cannot rely on the sole VLC due to the limitation provided by the light which allows communications in visibility only, VLC can however be considered to complement other wireless communication technologies which could be overloaded in dense scenarios. In this paper we evaluate the performance of VLC connected vehicles when urban crowd sensing is addressed and we compare the performance of sole vehicular visible light networks with that of VLC as a complementary technology of IEEE 802.11p. Results, obtained through a realistic simulation tool taking into account both the roadmap constraints and the technologies protocols, help to understand when VLC provides the major improvement in terms of delivered data varying the number and position of RSUs and the FOV of the receiver.

  15. The Game of Contacts: Estimating the Social Visibility of Groups.

    Science.gov (United States)

    Salganik, Matthew J; Mello, Maeve B; Abdo, Alexandre H; Bertoni, Neilane; Fazito, Dimitri; Bastos, Francisco I

    2011-01-01

    Estimating the sizes of hard-to-count populations is a challenging and important problem that occurs frequently in social science, public health, and public policy. This problem is particularly pressing in HIV/AIDS research because estimates of the sizes of the most at-risk populations-illicit drug users, men who have sex with men, and sex workers-are needed for designing, evaluating, and funding programs to curb the spread of the disease. A promising new approach in this area is the network scale-up method, which uses information about the personal networks of respondents to make population size estimates. However, if the target population has low social visibility, as is likely to be the case in HIV/AIDS research, scale-up estimates will be too low. In this paper we develop a game-like activity that we call the game of contacts in order to estimate the social visibility of groups, and report results from a study of heavy drug users in Curitiba, Brazil (n = 294). The game produced estimates of social visibility that were consistent with qualitative expectations but of surprising magnitude. Further, a number of checks suggest that the data are high-quality. While motivated by the specific problem of population size estimation, our method could be used by researchers more broadly and adds to long-standing efforts to combine the richness of social network analysis with the power and scale of sample surveys.

  16. Visible nulling coronagraphy testbed development for exoplanet detection

    Science.gov (United States)

    Lyon, Richard G.; Clampin, Mark; Woodruff, Robert A.; Vasudevan, Gopal; Thompson, Patrick; Chen, Andrew; Petrone, Peter; Booth, Andrew; Madison, Timothy; Bolcar, Matthew; Noecker, M. Charley; Kendrick, Stephen; Melnick, Gary; Tolls, Volker

    2010-07-01

    Three of the recently completed NASA Astrophysics Strategic Mission Concept (ASMC) studies addressed the feasibility of using a Visible Nulling Coronagraph (VNC) as the prime instrument for exoplanet science. The VNC approach is one of the few approaches that works with filled, segmented and sparse or diluted aperture telescope systems and thus spans the space of potential ASMC exoplanet missions. NASA/Goddard Space Flight Center (GSFC) has a well-established effort to develop VNC technologies and has developed an incremental sequence of VNC testbeds to advance the this approach and the technologies associated with it. Herein we report on the continued development of the vacuum Visible Nulling Coronagraph testbed (VNT). The VNT is an ultra-stable vibration isolated testbed that operates under high bandwidth closed-loop control within a vacuum chamber. It will be used to achieve an incremental sequence of three visible light nulling milestones of sequentially higher contrasts of 108, 109 and 1010 at an inner working angle of 2*λ/D and ultimately culminate in spectrally broadband (>20%) high contrast imaging. Each of the milestones, one per year, is traceable to one or more of the ASMC studies. The VNT uses a modified Mach-Zehnder nulling interferometer, modified with a modified "W" configuration to accommodate a hex-packed MEMS based deformable mirror, a coherent fiber bundle and achromatic phase shifters. Discussed will be the optical configuration laboratory results, critical technologies and the null sensing and control approach.

  17. Development and validation of satellite based estimates of surface visibility

    Science.gov (United States)

    Brunner, J.; Pierce, R. B.; Lenzen, A.

    2015-10-01

    A satellite based surface visibility retrieval has been developed using Moderate Resolution Imaging Spectroradiometer (MODIS) measurements as a proxy for Advanced Baseline Imager (ABI) data from the next generation of Geostationary Operational Environmental Satellites (GOES-R). The retrieval uses a multiple linear regression approach to relate satellite aerosol optical depth, fog/low cloud probability and thickness retrievals, and meteorological variables from numerical weather prediction forecasts to National Weather Service Automated Surface Observing System (ASOS) surface visibility measurements. Validation using independent ASOS measurements shows that the GOES-R ABI surface visibility retrieval (V) has an overall success rate of 64.5% for classifying Clear (V ≥ 30 km), Moderate (10 km ≤ V United States Environmental Protection Agency (EPA) and National Park Service (NPS) Interagency Monitoring of Protected Visual Environments (IMPROVE) network, and provide useful information to the regional planning offices responsible for developing mitigation strategies required under the EPA's Regional Haze Rule, particularly during regional haze events associated with smoke from wildfires.

  18. Vehicular Visible Light Networks for Urban Mobile Crowd Sensing.

    Science.gov (United States)

    Masini, Barbara M; Bazzi, Alessandro; Zanella, Alberto

    2018-04-12

    Crowd sensing is a powerful tool to map and predict interests and events. In the future, it could be boosted by an increasing number of connected vehicles sharing information and intentions. This will be made available by on board wireless connected devices able to continuously communicate with other vehicles and with the environment. Among the enabling technologies, visible light communication (VLC) represents a low cost solution in the short term. In spite of the fact that vehicular communications cannot rely on the sole VLC due to the limitation provided by the light which allows communications in visibility only, VLC can however be considered to complement other wireless communication technologies which could be overloaded in dense scenarios. In this paper we evaluate the performance of VLC connected vehicles when urban crowd sensing is addressed and we compare the performance of sole vehicular visible light networks with that of VLC as a complementary technology of IEEE 802.11p. Results, obtained through a realistic simulation tool taking into account both the roadmap constraints and the technologies protocols, help to understand when VLC provides the major improvement in terms of delivered data varying the number and position of RSUs and the FOV of the receiver.

  19. Visibility Network Patterns and Methods for Studying Visual Relational Phenomena in Archeology

    Directory of Open Access Journals (Sweden)

    Tom Brughmans

    2017-08-01

    Full Text Available A review of the archeological and non-archeological use of visibility networks reveals the use of a limited range of formal techniques, in particular for representing visibility theories. This paper aims to contribute to the study of complex visual relational phenomena in landscape archeology by proposing a range of visibility network patterns and methods. We propose first- and second-order visibility graph representations of total and cumulative viewsheds, and two-mode representations of cumulative viewsheds. We present network patterns that can be used to represent aspects of visibility theories and that can be used in statistical simulation models to compare theorized networks with observed networks. We argue for the need to incorporate observed visibility network density in these simulation models, by illustrating strong differences in visibility network density in three example landscapes. The approach is illustrated through a brief case study of visibility networks of long barrows in Cranborne Chase.

  20. Photocatalytic Surface Patterning of Cellulose using Diazonium Salts and Visible Light

    OpenAIRE

    Schroll, Peter; Fehl, Charlie; Dankesreiter, Stephan; König, Burkhard

    2013-01-01

    Coumarin-functionalized cellulose sheets were chemically modified using a visible light catalyzed “Photo-Meerwein” arylation. Use of a photomask to pattern the surface resulted in directly visible images.

  1. Cloud Computing Infusion for Generating ESDRs of Visible Spectra Radiances

    Science.gov (United States)

    Golpayegani, N.; Halem, M.; Nguyen, P.

    2008-12-01

    The AIRS and AVHRR instruments have been collecting radiances of the Earth in the visible spectrum for over 25 years. These measurements have been used to develop such useful products as NDVI, Snow cover and depth, Outgoing long wave radiation and other products. Yet, no long-term data record of the level 1b visible spectra is available in a grid form to researchers for various climate studies. We present here an Earth System Data Record observed in the visible spectrum as gridded radiance fields of 8kmx10km grid resolution for the six years in the case of AIRS and from 1981 to the present for AVHRR. The AIRS data has four visible channels from 0.41μm to 0.94μm with an IFOV of 1 km and AVHRR has two visible channels in the 0.58μm to 1.00μm range also at 1 km. In order to process such large amounts of data on demand, two components need to be implemented,(i) a processing system capable of gridding TBs of data in a reasonable amount of time and (ii) a download mechanism to access and deliver the data to the processing system. We implemented a cloud computing approach to be able to process such large amounts of data. We use Hadoop, a distributed computation system developed by the Apache Software Foundation. With Hadoop, we are able to store the data in a distributed fashion, taking advantage of Hadoop's distributed file system (dfs). We also take advantage of Hadoop's MapReduce functionality to perform as much computations as is possible on available nodes of the UMBC bluegrit Cell cluster system that contain the data. We make use of the SOAR system developed under the ACCESS program to acquire and process the AIRS and AVHRR observations. Comparisons of the AIRS data witth selected periods of MODIS visible spectral channels on the same sattelite indicate the two instruments have maintained calibration consistency and continuity of their measurements over the six year period. Our download mechanism transfers the data from these instruments into hadoop's dfs. Our

  2. Investigation of Light-Emitting Diode (LED) Point Light Source Color Visibility against Complex Multicolored Backgrounds

    Science.gov (United States)

    2017-11-01

    authors. Statistical analyses and analysis plots were obtained using IBM SPSS Statistics.* 5.1 Threshold Visible Illuminance by LED Color and...LED Visibility vs. Outdoor Background Illuminance Across all camouflage materials, the outdoor distances of visibility are plotted with SPSS in Fig

  3. Evaluation of visible implant elastomer tags in zebrafish (Danio rerio

    Directory of Open Access Journals (Sweden)

    Claudia Hohn

    2013-11-01

    The use of the visible implant elastomer (VIE tagging system in zebrafish (Danio rerio was examined. Two tag orientations (horizontal and vertical at the dorsal fin base were tested for tag retention, tag fragmentation and whether VIE tags affected growth and survival of juvenile zebrafish (1–4 month post hatch. Six tag locations (abdomen, anal fin base, caudal peduncle, dorsal fin base, pectoral fin base, isthmus and 5 tag colors (yellow, red, pink, orange, blue were evaluated for ease of VIE tag application and tag visibility in adult zebrafish. Long-term retention (1 year and multiple tagging sites (right and left of dorsal fin and pectoral fin base were examined in adult zebrafish. Lastly, survival of recombination activation gene 1−/− (rag1−/− zebrafish was evaluated after VIE tagging. The best tag location was the dorsal fin base, and the most visible tag color was pink. Growth rate of juvenile zebrafish was not affected by VIE tagging. Horizontal tagging is recommended in early stages of fish growth (1–2 months post hatch. VIE tags were retained for 1 year and tagging did not interfere with long-term growth and survival. There was no mortality associated with VIE tagging in rag1−/− zebrafish. The VIE tagging system is highly suitable for small-sized zebrafish. When familiar with the procedure, 120 adult zebrafish can be tagged in one hour. It does not increase mortality in adult zebrafish or interfere with growth in juvenile or adult zebrafish.

  4. ONLINE VISIBILITY OF THE TOURISTIC SUPPLY IN SUCEAVA COUNTY

    Directory of Open Access Journals (Sweden)

    Pavel STANCIU

    2012-12-01

    Full Text Available Due to the fact that the Internet is now a media zone that tends to monopolize the entire tourist advertising, a careful analysis is required to determine its impact on the marketing activity of the tourist accommodation structures in Bucovina. The major objective of the study aims to highlight the stage development of the touristic accommodation structures in Suceava County through the online visibility filter and, implicitly, their familiarisation with the specific techniques, strategies and marketing methods of the virtual environment.

  5. Silicon nitride photonics: from visible to mid-infrared wavelengths

    Science.gov (United States)

    Micó, Gloria; Bru, Luis A.; Pastor, Daniel; Doménech, David; Fernández, Juan; Sánchez, Ana; Cirera, Josep M.; Domínguez, Carlos; Muñoz, Pascual

    2018-02-01

    Silicon nitride has received a lot of attention during the last ten years, for applications such as bio-photonics, tele/datacom, optical signal processing and sensing. In this paper, firstly an updated review of the state of the art of silicon nitride photonics integration platforms will be provided. Secondly, our developments on a moderate confinement Si3N4 platform in the near-infrared will be presented. Finally, our steps towards establishing a Si3N4 based platform for broadband operation spanning from visible to mid-infrared wavelengths will be introduced.

  6. UV Visibility of Moderate-Redshift Giant Elliptical Galaxies

    Directory of Open Access Journals (Sweden)

    Myung-Hyun Rhee

    1998-06-01

    Full Text Available We show quantitatively whether giant elliptical galaxies would be visible at far UV wavelengths if they were placed at moderate redshift of 0.4-0.5. On the basis of simple cosmological tests, we conclude that giant elliptical galaxies can be detectable upto the redshift of 0.4-0.5 in the proposed GALEX (Galaxy Evolution Explorer Deep Imaging Survey. We also show that obtaining UV color index such as m_1550 - V from upcoming GALEX and SDSS (Sloan Digital Sky Survey observations should be feasible.

  7. Lunar UV-visible-IR mapping interferometric spectrometer

    Science.gov (United States)

    Smith, W. Hayden; Haskin, L.; Korotev, R.; Arvidson, R.; Mckinnon, W.; Hapke, B.; Larson, S.; Lucey, P.

    1992-01-01

    Ultraviolet-visible-infrared mapping digital array scanned interferometers for lunar compositional surveys was developed. The research has defined a no-moving-parts, low-weight and low-power, high-throughput, and electronically adaptable digital array scanned interferometer that achieves measurement objectives encompassing and improving upon all the requirements defined by the LEXSWIG for lunar mineralogical investigation. In addition, LUMIS provides a new, important, ultraviolet spectral mapping, high-spatial-resolution line scan camera, and multispectral camera capabilities. An instrument configuration optimized for spectral mapping and imaging of the lunar surface and provide spectral results in support of the instrument design are described.

  8. Performance comparison of binary modulation schemes for visible light communication

    KAUST Repository

    Park, Kihong

    2015-09-11

    In this paper, we investigate the power spectral density of several binary modulation schemes including variable on-off keying, variable pulse position modulation, and pulse dual slope modulation which were previously proposed for visible light communication with dimming control. We also propose a novel slope-based modulation called differential chip slope modulation (DCSM) and develop a chip-based hard-decision receiver to demodulate the resulting signal, detect the chip sequence, and decode the input bit sequence. We show that the DCSM scheme can exploit spectrum density more efficiently than the reference schemes while providing an error rate performance comparable to them. © 2015 IEEE.

  9. Unified Origin for Baryonic Visible Matter and Antibaryonic Dark Matter

    International Nuclear Information System (INIS)

    Davoudiasl, Hooman; Morrissey, David E.; Tulin, Sean; Sigurdson, Kris

    2010-01-01

    We present a novel mechanism for generating both the baryon and dark matter densities of the Universe. A new Dirac fermion X carrying a conserved baryon number charge couples to the standard model quarks as well as a GeV-scale hidden sector. CP-violating decays of X, produced nonthermally in low-temperature reheating, sequester antibaryon number in the hidden sector, thereby leaving a baryon excess in the visible sector. The antibaryonic hidden states are stable dark matter. A spectacular signature of this mechanism is the baryon-destroying inelastic scattering of dark matter that can annihilate baryons at appreciable rates relevant for nucleon decay searches.

  10. Unified origin for baryonic visible matter and antibaryonic dark matter.

    Science.gov (United States)

    Davoudiasl, Hooman; Morrissey, David E; Sigurdson, Kris; Tulin, Sean

    2010-11-19

    We present a novel mechanism for generating both the baryon and dark matter densities of the Universe. A new Dirac fermion X carrying a conserved baryon number charge couples to the standard model quarks as well as a GeV-scale hidden sector. CP-violating decays of X, produced nonthermally in low-temperature reheating, sequester antibaryon number in the hidden sector, thereby leaving a baryon excess in the visible sector. The antibaryonic hidden states are stable dark matter. A spectacular signature of this mechanism is the baryon-destroying inelastic scattering of dark matter that can annihilate baryons at appreciable rates relevant for nucleon decay searches.

  11. First Dodo Trench with White Layer Visible in Dig Area

    Science.gov (United States)

    2008-01-01

    These color images were taken by NASA's Phoenix Mars Lander's Stereo Surface Imager on the ninth Martian day of the mission, or Sol 9 (June 3, 2008). The images of the trench shows a white layer that has been uncovered by the Robotic Arm (RA) scoop and is now visible in the wall of the trench. This trench was the first one dug by the RA to understand the Martian soil and plan the digging strategy. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  12. Implementing Mobile Virtual Exhibition to Increase Cultural Heritage Visibility

    Directory of Open Access Journals (Sweden)

    Cristian CIUREA

    2014-01-01

    Full Text Available The paper presents an implementation of iOS mobile application designed as a virtual exhibition, which aims to increase the accessibility and visibility of physical objects that composite cultural heritage elements. Mobile technologies have seen a huge evolution in the last years and people are very attracted by smartphones, tablets and other mobile devices. Taking into consideration the impact of mobile technologies in all the activity fields, an important research objective is to analyze the influence of mobile applications designed as virtual exhibitions on cultural heritage promotion and on people cultural needs.

  13. Continental Fog Attenuation Empirical Relationship from Measured Visibility Data

    Directory of Open Access Journals (Sweden)

    F. Nadeem

    2010-12-01

    Full Text Available Free Space Optics (FSO has the great potential for future communication applications. However, weather influenced reduced availability had been the main cause for its restricted growth. Among different weather influences fog plays the major role. A new model generalized for all FSO wavelengths, has been proposed for the prediction of continental fog attenuation using visibility data. The performance of the proposed model has been compared with well known models for measured attenuation data of Continental fog. The comparison has been performed in terms of Root Mean Square Error (RMSE.

  14. Discrimination against Visible Minority Immigrants: The Role of Work Experience

    Directory of Open Access Journals (Sweden)

    Yoko Yoshida

    2008-12-01

    Full Text Available There are two methods for estimating the earnings disadvantage of groups: the residual difference method and the Oaxaca-Blinder decomposition. Each method infers disadvantage from differences in earnings of visible minority immigrants and other Canadians, after controls for human capital and job characteristics. We: i summarize the logic of these methods; ii critically examine the character of the experience measures used in most of the research; iii apply the residual difference method to the Workplace and Employee Survey to show how a more thorough approach to the measurement of work experience modifies estimates of earnings disadvantage.

  15. Nanosecond high-power dense microplasma switch for visible light

    Energy Technology Data Exchange (ETDEWEB)

    Bataller, A., E-mail: bataller@physics.ucla.edu; Koulakis, J.; Pree, S.; Putterman, S. [Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095 (United States)

    2014-12-01

    Spark discharges in high-pressure gas are known to emit a broadband spectrum during the first 10 s of nanoseconds. We present calibrated spectra of high-pressure discharges in xenon and show that the resulting plasma is optically thick. Laser transmission data show that such a body is opaque to visible light, as expected from Kirchoff's law of thermal radiation. Nanosecond framing images of the spark absorbing high-power laser light are presented. The sparks are ideal candidates for nanosecond, high-power laser switches.

  16. Malaysian Journal of Medical Sciences Striving towards Visibility

    Science.gov (United States)

    GHAZLI, Nur Farahin; ABDULLAH, Jafri Malin

    2013-01-01

    The Malaysian Journal of Medical Sciences has in its 25 years “Silver Jubilee” achieved another milestone of being visible to the biomedical community when it was accepted in PubMed. The journal aim to increase its readership so as to increase impact in the biomedical field amongst its Asian readers despite having a high rejection rate. This was done to maintain quality of the manuscripts published over the years. PubMed listing should enable more manuscripts to be cited as its the leading biomedical journal for the Asian community. PMID:24043990

  17. Resource allocation for multichannel broadcasting visible light communication

    Science.gov (United States)

    Le, Nam-Tuan; Jang, Yeong Min

    2015-11-01

    Visible light communication (VLC), which offers the possibility of using light sources for both illumination and data communications simultaneously, will be a promising incorporation technique with lighting applications. However, it still remains some challenges especially coverage because of field-of-view limitation. In this paper, we focus on this issue by suggesting a resource allocation scheme for VLC broadcasting system. By using frame synchronization and a network calculus QoS approximation, as well as diversity technology, the proposed VLC architecture and QoS resource allocation for the multichannel-broadcasting MAC (medium access control) protocol can solve the coverage limitation problem and the link switching problem of exhibition service.

  18. Visible light communication: Applications, architecture, standardization and research challenges

    Directory of Open Access Journals (Sweden)

    Latif Ullah Khan

    2017-05-01

    Full Text Available The Radio Frequency (RF communication suffers from interference and high latency issues. Along with this, RF communication requires a separate setup for transmission and reception of RF waves. Overcoming the above limitations, Visible Light Communication (VLC is a preferred communication technique because of its high bandwidth and immunity to interference from electromagnetic sources. The revolution in the field of solid state lighting leads to the replacement of florescent lamps by Light Emitting Diodes (LEDs which further motivates the usage of VLC. This paper presents a survey of the potential applications, architecture, modulation techniques, standardization and research challenges in VLC.

  19. Performing accountability: Making environmental credentials visible in housing design

    International Nuclear Information System (INIS)

    Shaw, Isabel; Ozaki, Ritsuko

    2015-01-01

    Making housing developments ‘environmentally sustainable’ requires housing developers to be accountable for their ‘green’ credentials. Accountability is promoted by both the UK government's environmental policy for housing design – the Code for Sustainable Homes – and local councils in their planning criteria. These accountability practices are key to how relationships between housing professionals and local planning authorities influence practices and outcomes of environmental sustainability. In this article, we examine how accountability is performed in housing design and development. We argue that accountability practices involve the management of making environmental sustainability visible through demonstrating the utilization of sustainable technologies. We contend that these ‘visibility’ practices are carried out to the detriment of an appreciation of how energy is both provided and consumed. We contend that using the installation phase of sustainable technologies as a point of adequate assessment of the environmental effectiveness of a building is short-sighted. Policy needs to look beyond this, and consult with professionals who develop and sell houses to understand better their working priorities and contexts that shape the provision of renewable energy in the planning phase and post-build. - Highlights: • Accountability practices shape environmental sustainability practices and outcomes. • Making sustainability ‘visible’ involves the use of sustainable technologies. • Policy should consider how it affects professionals work and energy provision. • Visibility practices influence energy provision and potential consumption.

  20. Identifying position, visibility, dimensions, and angulation of the ear.

    Science.gov (United States)

    Mohamed, Kasim; Christian, Jayanth; Jeyapalan, Karthigeyan; Natarajan, Shanmuganathan; Banu, Fathima; Veeravalli, Padmanabhan T

    2014-01-01

    We selected 254 subjects between the ages of 18 and 30 yr to assess the ear position, angulations of the ear in relation to the nose, visibility from the frontal view, and dimensions of the ear by using various anthropometric points of the face. Subjects were divided into four groups based on facial form. A reference plane indicator, facial topographical measurements, metal ruler, and digital photography were used. While considering the position of the ear, in all facial forms except square tapering, the most samples showed a tendency for the subaurale being in line with subnasale. Regression analysis showed a tendency to gnathion distance is the most dependent variable with length of the ear kept as a constant predictor, while both interalar distance and exocanthion to endocanthion distance correlate highly significantly to the width of the ear. In all subjects, the visibility of the ear when viewed from the front was an average of 1.5 mm. Regardless of facial form, ear angulation was generally less than nose angulation.

  1. LED-based high-speed visible light communications

    Science.gov (United States)

    Chi, Nan; Shi, Meng; Zhao, Yiheng; Wang, Fumin; Shi, Jianyang; Zhou, Yingjun; Lu, Xingyu; Qiao, Liang

    2018-01-01

    We are seeing a growing use of light emitting diodes (LEDs) in a range of applications including lighting, TV and backlight board screen, display etc. In comparison with the traditional incandescent and fluorescent light bulbs, LEDs offer long life-space, much higher energy efficiency, high performance cost ratio and above all very fast switching capability. LED based Visible Light Communications (VLC) is an emerging field of optical communications that focuses on the part of the electromagnetic spectrum that humans can see. Depending on the transmission distance, we can divide the whole optical network into two categories, long haul and short haul. Visible light communication can be a promising candidate for short haul applications. In this paper, we outline the configuration of VLC, its unique benefits, and describe the state of the art research contributions consisting of advanced modulation formats including adaptive bit loading OFDM, carrierless amplitude and phase (CAP), pulse amplitude modulation (PAM) and single carrier Nyquist, linear equalization and nonlinear distortion mitigation based on machine learning, quasi-balanced coding and phase-shifted Manchester coding. These enabling technologies can support VLC up to 10Gb/s class free space transmission.

  2. Invisibility Cloaking Based on Geometrical Optics for Visible Light

    Science.gov (United States)

    Ichikawa, H.; Oura, M.; Taoda, T.

    2013-06-01

    Optical cloaking has been one of unattainable dreams and just a subject in fiction until recently. Several different approaches to cloaking have been proposed and demonstrated: stealth technology, active camouflage and transformation optics. The last one would be the most formal approach modifying electromagnetic field around an object to be cloaked with metamaterials. While cloaking based on transformation optics, though valid only at single frequency, is experimentally demonstrated in microwave region, its operation in visible spectrum is still distant from realisation mainly owing to difficulty in fabricating metamaterial structure whose elements are much smaller than wavelength of light. Here we show that achromatic optical cloaking in visible spectrum is possible with the mere principle based on geometrical optics. In combining a pair of polarising beam splitters and right-angled prisms, rays of light to be obstructed by an object can make a detour to an observer, while unobstructed rays go straight through two polarising beam splitters. What is observed eventually through the device is simply background image as if nothing exists in between.

  3. The refractive index of human hemoglobin in the visible range

    International Nuclear Information System (INIS)

    Zhernovaya, O; Tuchin, V; Sydoruk, O; Douplik, A

    2011-01-01

    Because the refractive index of hemoglobin in the visible range is sensitive to the hemoglobin concentration, optical investigations of hemoglobin are important for medical diagnostics and treatment. Direct measurements of the refractive index are, however, challenging; few such measurements have previously been reported, especially in a wide wavelength range. We directly measured the refractive index of human deoxygenated and oxygenated hemoglobin for nine wavelengths between 400 and 700 nm for the hemoglobin concentrations up to 140 g l -1 . This paper analyzes the results and suggests a set of model functions to calculate the refractive index depending on the concentration. At all wavelengths, the measured values of the refractive index depended on the concentration linearly. Analyzing the slope of the lines, we determined the specific refraction increments, derived a set of model functions for the refractive index depending on the concentration, and compared our results with those available in the literature. Based on the model functions, we further calculated the refractive index at the physiological concentration within the erythrocytes of 320 g l -1 . The results can be used to calculate the refractive index in the visible range for arbitrary concentrations provided that the refractive indices depend on the concentration linearly.

  4. Multiplex visibility graphs to investigate recurrent neural network dynamics

    Science.gov (United States)

    Bianchi, Filippo Maria; Livi, Lorenzo; Alippi, Cesare; Jenssen, Robert

    2017-03-01

    A recurrent neural network (RNN) is a universal approximator of dynamical systems, whose performance often depends on sensitive hyperparameters. Tuning them properly may be difficult and, typically, based on a trial-and-error approach. In this work, we adopt a graph-based framework to interpret and characterize internal dynamics of a class of RNNs called echo state networks (ESNs). We design principled unsupervised methods to derive hyperparameters configurations yielding maximal ESN performance, expressed in terms of prediction error and memory capacity. In particular, we propose to model time series generated by each neuron activations with a horizontal visibility graph, whose topological properties have been shown to be related to the underlying system dynamics. Successively, horizontal visibility graphs associated with all neurons become layers of a larger structure called a multiplex. We show that topological properties of such a multiplex reflect important features of ESN dynamics that can be used to guide the tuning of its hyperparamers. Results obtained on several benchmarks and a real-world dataset of telephone call data records show the effectiveness of the proposed methods.

  5. Bismuth titanate nanorods and their visible light photocatalytic properties

    International Nuclear Information System (INIS)

    Pei, L.Z.; Liu, H.D.; Lin, N.; Yu, H.Y.

    2015-01-01

    Highlights: • Bismuth titanate nanorods have been synthesized by a simple hydrothermal process. • The size of bismuth titanate nanorods can be controlled by growth conditions. • Bismuth titanate nanorods show good photocatalytic activities of methylene blue and Rhodamine B. - Abstract: Bismuth titanate nanorods have been prepared using a facile hydrothermal process without additives. The bismuth titanate products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM) and UV-vis diffusion reflectance spectrum. XRD pattern shows that the bismuth titanate nanorods are composed of cubic Bi 2 Ti 2 O 7 phase. Electron microscopy images show that the length and diameter of the bismuth titanate nanorods are 50-200 nm and 2 μm, respectively. Hydrothermal temperature and reaction time play important roles on the formation and size of the bismuth titanate nanorods. UV-vis diffusion reflectance spectrum indicates that bismuth titanate nanorods have a band gap of 2.58 eV. The bismuth titanate nanorods exhibit good photocatalytic activities in the photocatalytic degradation of methylene blue (MB) and Rhodamine B (RB) under visible light irradiation. The bismuth titanate nanorods with cubic Bi 2 Ti 2 O 7 phase are a promising candidate as a visible light photocatalyst

  6. Visible spectroscopy in the DIII-D divertor

    International Nuclear Information System (INIS)

    Brooks, N.H.; Fehling, D.; Hillis, D.L.; Klepper, C.C.; Naumenko, N.; Tugarinov, S.; Whyte, D.G.

    1996-06-01

    Spectroscopy measurements in the DIII-D divertor have been carried out with a survey spectrometer which provides simultaneous registration of the visible spectrum over the region 400--900 nm with a resolution of 0.2 nm. Broad spectral coverage is achieved through use of a fiberoptic transformer assembly to map the curved focal plane of a fast (f/3) Rowland spectrograph into a rastered format on the rectangular sensor area of a two-dimensional CCD camera. Vertical grouping of pixels during CCD readout integrates the signal intensity over the height of each spectral segment in the rastered image, minimizing readout time. For the full visible spectrum, readout time is 50 ms. Faster response time (< 10 ms) may be obtained by selecting for readout just a small number of the twenty spectral segments in the image on the CCD. Simultaneous recording of low charge states of carbon, oxygen and injected impurities has yielded information about gas recycling and impurity behavior at the divertor strike points. Transport of lithium to the divertor region during lithium pellet injection has been studied, as well as cumulative deposition of lithium on the divertor targets from pellet injection over many successive discharges

  7. Design of a visible-light spectroscopy clinical tissue oximeter.

    Science.gov (United States)

    Benaron, David A; Parachikov, Ilian H; Cheong, Wai-Fung; Friedland, Shai; Rubinsky, Boris E; Otten, David M; Liu, Frank W H; Levinson, Carl J; Murphy, Aileen L; Price, John W; Talmi, Yair; Weersing, James P; Duckworth, Joshua L; Hörchner, Uwe B; Kermit, Eben L

    2005-01-01

    We develop a clinical visible-light spectroscopy (VLS) tissue oximeter. Unlike currently approved near-infrared spectroscopy (NIRS) or pulse oximetry (SpO2%), VLS relies on locally absorbed, shallow-penetrating visible light (475 to 625 nm) for the monitoring of microvascular hemoglobin oxygen saturation (StO2%), allowing incorporation into therapeutic catheters and probes. A range of probes is developed, including noncontact wands, invasive catheters, and penetrating needles with injection ports. Data are collected from: 1. probes, standards, and reference solutions to optimize each component; 2. ex vivo hemoglobin solutions analyzed for StO2% and pO2 during deoxygenation; and 3. human subject skin and mucosal tissue surfaces. Results show that differential VLS allows extraction of features and minimization of scattering effects, in vitro VLS oximetry reproduces the expected sigmoid hemoglobin binding curve, and in vivo VLS spectroscopy of human tissue allows for real-time monitoring (e.g., gastrointestinal mucosal saturation 69+/-4%, n=804; gastrointestinal tumor saturation 45+/-23%, n=14; and p<0.0001), with reproducible values and small standard deviations (SDs) in normal tissues. FDA approved VLS systems began shipping earlier this year. We conclude that VLS is suitable for the real-time collection of spectroscopic and oximetric data from human tissues, and that a VLS oximeter has application to the monitoring of localized subsurface hemoglobin oxygen saturation in the microvascular tissue spaces of human subjects.

  8. Academic visibility for urban planning and the webometric future

    Directory of Open Access Journals (Sweden)

    Sanchez Thomas W.

    2015-03-01

    Full Text Available The author focuses on the analysis problems of the main metrics of scientific productivity for the faculty in the USA universities specializing in the investigations and teaching in the field of urban planning. The increasing role of the Internet is highlighted in the process of communicating the ideas of planning scientists to the professionals and public, extending the reach of academic communications and possibilities of estimating the quality of the investigations and impact. Using case study the methods of applying webometrics for citation analysis in the Internet are investigated. The analysis focused on the main criteria: productivity, visibility, reputation, and impact. The article proposes an expanded approach for estimating general scientific popularity and impact of academics in the Internet, which includes publication analysis in frames of “gray literature”, teaching and outreach activity, which may also be a significant part of the scientific activity. The author stated the importance of academic visibility estimation both for promotion, improving competitiveness of a faculty member on the labor market in the sphere of educational services, and for urban planning schools’ development in general, raising their reputation, prestige and impact, getting the opportunities for financed researches, consolidating the positions on the global educational and science market.

  9. Psychological and social correlates of HIV status disclosure: the significance of stigma visibility.

    Science.gov (United States)

    Stutterheim, Sarah E; Bos, Arjan E R; Pryor, John B; Brands, Ronald; Liebregts, Maartje; Schaalma, Herman P

    2011-08-01

    HIV-related stigma, psychological distress, self-esteem, and social support were investigated in a sample comprising people who have concealed their HIV status to all but a selected few (limited disclosers), people who could conceal but chose to be open (full disclosers), and people who had visible symptoms that made concealing difficult (visibly stigmatized). The visibly stigmatized and full disclosers reported significantly more stigma experiences than limited disclosers, but only the visibly stigmatized reported more psychological distress, lower self-esteem, and less social support than limited disclosers. This suggests that having a visible stigma is more detrimental than having a concealable stigma. Differences in psychological distress and self-esteem between the visibly stigmatized and full disclosers were mediated by social support while differences between the visibly stigmatized and limited disclosers were mediated by both social support and stigma. These findings suggest that social support buffers psychological distress in people with HIV.

  10. Can you tell that I'm in a relationship? Attachment and relationship visibility on Facebook.

    Science.gov (United States)

    Emery, Lydia F; Muise, Amy; Dix, Emily L; Le, Benjamin

    2014-11-01

    People often attempt to shape others' perceptions of them, but the role of romantic relationships in this process is unknown. The present set of studies investigates relationship visibility, the centrality of relationships in the self-images that people convey to others. We propose that attachment underlies relationship visibility and test this hypothesis across three studies in the context of Facebook. Avoidant individuals showed low desire for relationship visibility, whereas anxious individuals reported high desired visibility (Studies 1 and 2); however, similar motives drove both groups' actual relationship visibility (Study 1). Moreover, both avoidant individuals and their partners were less likely to make their relationships visible (Studies 1 and 3). On a daily basis, when people felt more insecure about their partner's feelings, they tended to make their relationships visible (Study 3). These studies highlight the role of relationships in how people portray themselves to others. © 2014 by the Society for Personality and Social Psychology, Inc.

  11. Refining and augmenting Central Mediterranean Tephrochronologies using visible and non-visible distal ash layers from the Upper Pleistocene

    Science.gov (United States)

    Bourne, A.; Trincardi, F.; Blockley, S. P. E.; Lowe, J. J.

    2009-04-01

    The development of long and well dated regional records of environmental change is essential if we are to understand the long term working of the environmental system. The application of volcanic ash layers as time-parallel markers is developing as a tool to link archaeological and geological sequences. This presentation will make a key contribution to the PROMESS 1 European Project - PROfiles across Mediterranean Sedimentary System (http://promess1.pangaea.de/ ). The project aims to understand the sediment systems of Continental Margins by investigating changes in sea level, oceanographic regime and sediment flux. The precise and robust chronological control that is required to address these issues is frequently unavailable using traditional chronological techniques. Tephrochronology offers the potential of isochronous marker horizons that can provide independent age estimates and be used to correlate terrestrial and marine sequences over several glacial-interglacial cycles. Here we will summarise new tephrochronological results for the PROMESS-1 marine core PRAD 1-2, obtained from a water depth of 184m in the central Adriatic. The recovered sediment sequence is 71m long, spans at least 3 glacial-interglacial cycles and analysis of foraminiferal assemblages suggests the sequence extends back to Marine Isotope Stage 10. Current Central Mediterranean tephrochronology schemes are largely or entirely based on analysis of visible tephra layers. Density separation extraction techniques have been developed (Turney 1998; Blockley et al, 2005) which demonstrate that many more non-visible tephra layers exist than have previously been recognised in Mediterranean sequences, greatly enhancing the potential of tephrochronology as an independent dating method. A detailed Adriatic tephrochronology for the last 100kyr will be presented which indicates a more complicated eruptive history than visible tephra layers have previously suggested. 24 discrete and undisturbed non-visible

  12. Visible spectroscopy at the Extrap-T1 pinch experiment

    International Nuclear Information System (INIS)

    Bengtsson, P.; Brzozowski, J.H.; Kaellne, E.; Zaztrow, K.D.

    1991-06-01

    A wide range UV to visible spectrum from 2450 to 8050 Angstrom has been acquired and analysed for the EXTRAP-T1 plasma. The impurity lines in the spectrum are mainly from carbon and oxygen species up to four times ionized, but also nitrogen lines are present. No traces of metal impurity are observed. We have identified most of the spectral lines and compare intensities from several multiplets with predicted values. A spectral range free from line emission is found which is suitable for continuum measurements. Furthermore, line strictures are identified as originating from the CH molecule and are observed both using a center chord line of sight and an edge chord line-of-sight through the plasma. (au)

  13. Female visibility through Korean literature: Feminist theological critique

    Directory of Open Access Journals (Sweden)

    Eun Ok Jeong

    2003-10-01

    Full Text Available This article introduces Korean women’s experience as seen through the lense of social and cultural backgrounds, from the premodern through to the postmodern era. Korean literature is used as a source to investigate Korean women’s experiences and perspectives. By means of feminist critique this article explores men-centered influences in Korean literature. It aims to illustrate the importance of the issue of female visibility through Korean literature from a Korean woman’s perspective. Two texts are analyzed and critiqued: the first is the myth of Korean origin. The second is a story of Gasi Gogi (a thorny fish. The article is intended to stimulate debate on gender, voices, and authority from a feminist perspective, in order to transcend the more traditional interpretations.

  14. Downlink resource allocation for multichannel TDMA visible light communications

    KAUST Repository

    Abdelhady, Amr Mohamed Abdelaziz

    2017-05-12

    Optical wireless communications (OWC) in general and resource allocation in OWC networks particularly have gained lots of attention recently. In this work, we consider the resource allocation problem of a visible light communication downlink transmission system based on time division multiple access with the objective of maximizing spectral efficiency (SE). As for the operational conditions, we impose constraints on the average optical intensity, the energy consumption and the quality-of-service. To solve the non-convex problem, we transform the objective function into a difference of concave functions by solving a second order differential inequality. Then, we propose a low-complexity algorithm to solve the resource allocation problem. Finally, we show by simulations the SE performance gains achieved by optimizing the power allocation over equal power allocation in the considered system. Numerical results show the SE gains achieved by using this solution.

  15. Optimal linear precoding for indoor visible light communication system

    KAUST Repository

    Sifaou, Houssem

    2017-07-31

    Visible light communication (VLC) is an emerging technique that uses light-emitting diodes (LED) to combine communication and illumination. It is considered as a promising scheme for indoor wireless communication that can be deployed at reduced costs while offering high data rate performance. In this paper, we focus on the design of the downlink of a multi-user VLC system. Inherent to multi-user systems is the interference caused by the broadcast nature of the medium. Linear precoding based schemes are among the most popular solutions that have recently been proposed to mitigate inter-user interference. This paper focuses on the design of the optimal linear precoding scheme that solves the max-min signal-to-interference-plus-noise ratio (SINR) problem. The performance of the proposed precoding scheme is studied under different working conditions and compared with the classical zero-forcing precoding. Simulations have been provided to illustrate the high gain of the proposed scheme.

  16. Noise analysis for CCD-based ultraviolet and visible spectrophotometry.

    Science.gov (United States)

    Davenport, John J; Hodgkinson, Jane; Saffell, John R; Tatam, Ralph P

    2015-09-20

    We present the results of a detailed analysis of the noise behavior of two CCD spectrometers in common use, an AvaSpec-3648 CCD UV spectrometer and an Ocean Optics S2000 Vis spectrometer. Light sources used include a deuterium UV/Vis lamp and UV and visible LEDs. Common noise phenomena include source fluctuation noise, photoresponse nonuniformity, dark current noise, fixed pattern noise, and read noise. These were identified and characterized by varying light source, spectrometer settings, or temperature. A number of noise-limiting techniques are proposed, demonstrating a best-case spectroscopic noise equivalent absorbance of 3.5×10(-4)  AU for the AvaSpec-3648 and 5.6×10(-4)  AU for the Ocean Optics S2000 over a 30 s integration period. These techniques can be used on other CCD spectrometers to optimize performance.

  17. Detection of unmanned aerial vehicles using a visible camera system.

    Science.gov (United States)

    Hu, Shuowen; Goldman, Geoffrey H; Borel-Donohue, Christoph C

    2017-01-20

    Unmanned aerial vehicles (UAVs) flown by adversaries are an emerging asymmetric threat to homeland security and the military. To help address this threat, we developed and tested a computationally efficient UAV detection algorithm consisting of horizon finding, motion feature extraction, blob analysis, and coherence analysis. We compare the performance of this algorithm against two variants, one using the difference image intensity as the motion features and another using higher-order moments. The proposed algorithm and its variants are tested using field test data of a group 3 UAV acquired with a panoramic video camera in the visible spectrum. The performance of the algorithms was evaluated using receiver operating characteristic curves. The results show that the proposed approach had the best performance compared to the two algorithmic variants.

  18. Quantifying Pilot Visual Attention in Low Visibility Terminal Operations

    Science.gov (United States)

    Ellis, Kyle K.; Arthur, J. J.; Latorella, Kara A.; Kramer, Lynda J.; Shelton, Kevin J.; Norman, Robert M.; Prinzel, Lawrence J.

    2012-01-01

    Quantifying pilot visual behavior allows researchers to determine not only where a pilot is looking and when, but holds implications for specific behavioral tracking when these data are coupled with flight technical performance. Remote eye tracking systems have been integrated into simulators at NASA Langley with effectively no impact on the pilot environment. This paper discusses the installation and use of a remote eye tracking system. The data collection techniques from a complex human-in-the-loop (HITL) research experiment are discussed; especially, the data reduction algorithms and logic to transform raw eye tracking data into quantified visual behavior metrics, and analysis methods to interpret visual behavior. The findings suggest superior performance for Head-Up Display (HUD) and improved attentional behavior for Head-Down Display (HDD) implementations of Synthetic Vision System (SVS) technologies for low visibility terminal area operations. Keywords: eye tracking, flight deck, NextGen, human machine interface, aviation

  19. High accuracy wavelength calibration for a scanning visible spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Scotti, Filippo; Bell, Ronald E. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2010-10-15

    Spectroscopic applications for plasma velocity measurements often require wavelength accuracies {<=}0.2 A. An automated calibration, which is stable over time and environmental conditions without the need to recalibrate after each grating movement, was developed for a scanning spectrometer to achieve high wavelength accuracy over the visible spectrum. This method fits all relevant spectrometer parameters using multiple calibration spectra. With a stepping-motor controlled sine drive, an accuracy of {approx}0.25 A has been demonstrated. With the addition of a high resolution (0.075 arc sec) optical encoder on the grating stage, greater precision ({approx}0.005 A) is possible, allowing absolute velocity measurements within {approx}0.3 km/s. This level of precision requires monitoring of atmospheric temperature and pressure and of grating bulk temperature to correct for changes in the refractive index of air and the groove density, respectively.

  20. A novel mirror diversity receiver for indoor MIMO visible light

    KAUST Repository

    Park, Ki-Hong

    2016-03-01

    In this paper, we propose and study a non-imaging receiver design reducing the correlation of channel matrix for indoor multiple-input multiple-output (MIMO) visible light communication (VLC) systems. Contrary to previous works, our proposed mirror diversity receiver (MDR) not only blocks the reception of light on one specific direction but also improves the channel gain on the other direction by receiving the light reflected by a mirror deployed between the photodetectors. We analyze the channel capacity and optimal height of mirror in terms of maximum channel capacity for a 2 -by-2 MIMO-VLC system in a 2-dimensional geometric model.We prove that this constructive and destructive effects in channel matrix resulting from our proposed MDR are more beneficial to obtain well-conditioned channel matrix which is suitable for implementing spatial-multiplexing MIMO-VLC systems in order to support high data rate.

  1. Downlink resource allocation for multichannel TDMA visible light communications

    KAUST Repository

    Abdelhady, Amr Mohamed Abdelaziz; Amin, Osama; Chaaban, Anas; Alouini, Mohamed-Slim

    2017-01-01

    Optical wireless communications (OWC) in general and resource allocation in OWC networks particularly have gained lots of attention recently. In this work, we consider the resource allocation problem of a visible light communication downlink transmission system based on time division multiple access with the objective of maximizing spectral efficiency (SE). As for the operational conditions, we impose constraints on the average optical intensity, the energy consumption and the quality-of-service. To solve the non-convex problem, we transform the objective function into a difference of concave functions by solving a second order differential inequality. Then, we propose a low-complexity algorithm to solve the resource allocation problem. Finally, we show by simulations the SE performance gains achieved by optimizing the power allocation over equal power allocation in the considered system. Numerical results show the SE gains achieved by using this solution.

  2. All-fiber femtosecond Cherenkov laser at visible wavelengths

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Lægsgaard, Jesper; Møller, Uffe Visbech

    2013-01-01

    -matching condition [1]. The resonant ultrafast wave conversion via the fiber-optic CR mechanism is instrumental for applications in biophotonics such as bio-imaging and microscopy [2]. In this work, we demonstrate a highly-stable all-fiber, fully monolithic CR system based on an Yb-fiber femtosecond laser, producing...... to be as low as -103 dBc/Hz. This is 2 orders of magnitudes lower noise as compared to spectrally-sliced supercontinuum, which is the current standard of ultrafast fiber-optic generation at visible wavelength. The layout of the laser system is shown in Fig. 1(a). The system consists of two parts: an all-fiber......Fiber-optic Cherenkov radiation (CR), also known as dispersive wave generation or non-solitonic radiation, is produced in small-core photonic crystal fibers (PCF) when a soliton perturbed by fiber higher-order dispersion co-propagates with a dispersive wave fulfilling a certain phase...

  3. Plasma diagnostics in the CECI device through visible spectroscopy

    International Nuclear Information System (INIS)

    Ueda, M.; Kayama, M.E.; Aso, Y.

    1991-11-01

    In this paper we discuss the application of a visible spectrometer which was used to diagnose a plasma produced in an RFP device, called CECI. A Jobin Yvon, HR-640 S spectrometer with a photomultiplier detector was used to measure the Doppler broadening of lines emitted by the plasma, and allowed to measure the ion temperatures of the order of 2-3 eV. The electron temperature of 40-50 eV was determined by the method of He I line intensity ratio. The spectroscopically determined ion temperature is in better accordance with the 10 eV electron temperature obtained with an electrostatic probe. The line emissions of He II, H I, C II and O II were compared with signals from other diagnostics, and their correlations indicated the presence of MHD instabilities in the plasma. (author)

  4. A new and inexpensive pyranometer for the visible spectral range.

    Science.gov (United States)

    Martínez, Miguel A; Andújar, José M; Enrique, Juan M

    2009-01-01

    This paper presents the design, construction and testing of a new photodiode-based pyranometer for the visible spectral range (approx. 400 to 750 nm), whose principal characteristics are: accuracy, ease of connection, immunity to noise, remote programming and operation, interior temperature regulation, cosine error minimisation and all this at a very low cost, tens of times lower than that of commercial thermopile-based devices. This new photodiode-based pyranometer overcomes traditional problems in this type of device and offers similar characteristics to those of thermopile-based pyranometers and, therefore, can be used in any installation where reliable measurement of solar irradiance is necessary, especially in those where cost is a deciding factor in the choice of a meter. This new pyranometer has been registered in the Spanish Patent and Trademark Office under the number P200703162.

  5. A New and Inexpensive Pyranometer for the Visible Spectral Range

    Directory of Open Access Journals (Sweden)

    Miguel A. Martínez

    2009-06-01

    Full Text Available This paper presents the design, construction and testing of a new photodiode-based pyranometer for the visible spectral range (approx. 400 to 750 nm, whose principal characteristics are: accuracy, ease of connection, immunity to noise, remote programming and operation, interior temperature regulation, cosine error minimisation and all this at a very low cost, tens of times lower than that of commercial thermopile-based devices. This new photodiode-based pyranometer overcomes traditional problems in this type of device and offers similar characteristics to those of thermopile-based pyranometers and, therefore, can be used in any installation where reliable measurement of solar irradiance is necessary, especially in those where cost is a deciding factor in the choice of a meter. This new pyranometer has been registered in the Spanish Patent and Trademark Office under the number P200703162.

  6. ERIH PLUS – Making the SSH visible, searchable and available

    Energy Technology Data Exchange (ETDEWEB)

    Lavik, G.A.; Sivertsen, G

    2016-07-01

    The European Reference Index for the Humanities and the Social Sciences (ERIH PLUS) is a non-commercial initiative to increase the visibility of the humanities and the social sciences (SSH) by providing an international infrastructure for a comprehensive bibliographic coverage of the scholarly communication and publishing in these fields. A well-defined, standardized and dynamic register of scholarly journals and series is already up and running. Since a combination of national and international publishing is practised in the SSH, titles in all European languages are covered in ERIH PLUS if they to correspond to six verifiable criteria. The register thereby challenges the commercial indexing services which tend to represent the SSH as “peripheral” to the sciences. (Author)

  7. Discrete Input Signaling for MISO Visible Light Communication Channels

    KAUST Repository

    Arfaoui, Mohamed Amine

    2017-05-12

    In this paper, we study the achievable secrecy rate of visible light communication (VLC) links for discrete input distributions. We consider single user single eavesdropper multiple-input single-output (MISO) links. In addition, both beamforming and robust beamforming are considered. In the former case, the location of the eavesdropper is assumed to be known, whereas in the latter case, the location of the eavesdropper is unknown. We compare the obtained results with those achieved by some continuous distributions including the truncated generalized normal (TGN) distribution and the uniform distribution. We numerically show that the secrecy rate achieved by the discrete input distribution with a finite support is significantly improved as compared to those achieved by the TGN and the uniform distributions.

  8. Colposcopic imaging using visible-light optical coherence tomography

    Science.gov (United States)

    Duan, Lian; McRaven, Michael D.; Liu, Wenzhong; Shu, Xiao; Hu, Jianmin; Sun, Cheng; Veazey, Ronald S.; Hope, Thomas J.; Zhang, Hao F.

    2017-05-01

    High-resolution colposcopic optical coherence tomography (OCT) provides key anatomical measures, such as thickness and minor traumatic injury of vaginal epithelium, of the female reproductive tract noninvasively. This information can be helpful in both fundamental investigations in animal models and disease screenings in humans. We present a fiber-based visible-light OCT and two probe designs for colposcopic application. One probe conducts circular scanning using a DC motor, and the other probe is capable of three-dimensional imaging over a 4.6×4.6-mm2 area using a pair of galvo scanners. Using this colposcopic vis-OCT with both probes, we acquired high-resolution images from whole isolated macaque vaginal samples and identified biopsy lesions.

  9. Visibility-based optimal path and motion planning

    CERN Document Server

    Wang, Paul Keng-Chieh

    2015-01-01

    This monograph deals with various visibility-based path and motion planning problems motivated by real-world applications such as exploration and mapping planetary surfaces, environmental surveillance using stationary or mobile robots, and imaging of global air/pollutant circulation. The formulation and solution of these problems call for concepts and methods from many areas of applied mathematics including computational geometry, set-covering, non-smooth optimization, combinatorial optimization and optimal control. Emphasis is placed on the formulation of new problems and methods of approach to these problems. Since geometry and visualization play important roles in the understanding of these problems, intuitive interpretations of the basic concepts are presented before detailed mathematical development. The development of a particular topic begins with simple cases illustrated by specific examples, and then progresses forward to more complex cases. The intended readers of this monograph are primarily studen...

  10. The Visible Nulling Coronagraph--Architecture Definition and Technology Development

    Science.gov (United States)

    Shao, Michael; Levine, B. Martin; Wallace, J. Kent; Liu, Duncan T.; Schmidtlin, Edouard; Serabyn, Eugene; Mennesson, Bertrand; Green, Joseph J.; Aguayo, Francisco; Fregoso, S. Felipe; hide

    2005-01-01

    This paper describes the advantages of visible direct detection and spectroscopy of Earth-like extrasolar planets using a nulling coronagraph instrument behind a moderately sized single aperture space telescope. Our concept synthesizes a nulling interferometer by shearing the telescope pupil, with the resultant producing a deep null. We describe nulling configurations that also include methods to mitigate stellar leakage, such as spatial filtering by a coherent array of single mode fibers, and post-starlight suppression wavefront sensing and control. With diffraction limited telescope optics and similar quality components in the optical train (lambda/20), suppression of the starlight to 1e-10 is readily achievable. We describe key features of the architecture and analysis, present latest results of laboratory measurements demonstrating achievable null depth and component development, and discuss future key technical milestones.

  11. Intrinsic defect oriented visible region absorption in zinc oxide films

    Science.gov (United States)

    Rakhesh, V.; Shankar, Balakrishnan

    2018-05-01

    Zinc Oxide films were deposited on the glass substrate using vacuum arc sputtering technology. Films were prepared in oxygen ambience for 10mA and 15 mA deposition current separately. The UV-Visible spectroscopy of the samples showed that both samples possess sharp absorption near 3.5eV which is the characteristic band gap absorption energy of ZnO films. The absorption coefficient were calculated for the samples and the (αℎϑ)2 vs energy plot is drawn. The plot suggested that in addition to the sharp band edge absorption, the sample prepared at 10mA deposition current showed sharp absorption edge near 1.51eV and that at 15 mA showed absorption edge near 1.47eV. This refers to the presence of an intrinsic defect level which is likely to be deep in the band gap.

  12. Visible Color and Photometry of Bright Materials on Vesta

    Science.gov (United States)

    Schroder, S. E.; Li, J. Y.; Mittlefehldt, D. W.; Pieters, C. M.; De Sanctis, M. C.; Hiesinger, H.; Blewett, D. T.; Russell, C. T.; Raymond, C. A.; Keller, H. U.

    2012-01-01

    The Dawn Framing Camera (FC) collected images of the surface of Vesta at a pixel scale of 70 m in the High Altitude Mapping Orbit (HAMO) phase through its clear and seven color filters spanning from 430 nm to 980 nm. The surface of Vesta displays a large diversity in its brightness and colors, evidently related to the diverse geology [1] and mineralogy [2]. Here we report a detailed investigation of the visible colors and photometric properties of the apparently bright materials on Vesta in order to study their origin. The global distribution and the spectroscopy of bright materials are discussed in companion papers [3, 4], and the synthesis results about the origin of Vestan bright materials are reported in [5].

  13. Origin of the visible emission of black silicon microstructures

    International Nuclear Information System (INIS)

    Fabbri, Filippo; Lin, Yu-Ting; Bertoni, Giovanni; Rossi, Francesca; Salviati, Giancarlo; Smith, Matthew J.; Gradečak, Silvija; Mazur, Eric

    2015-01-01

    Silicon, the mainstay semiconductor in microelectronics, is considered unsuitable for optoelectronic applications due to its indirect electronic band gap that limits its efficiency as light emitter. Here, we univocally determine at the nanoscale the origin of visible emission in microstructured black silicon by cathodoluminescence spectroscopy and imaging. We demonstrate the formation of amorphous silicon oxide microstructures with a white emission. The white emission is composed by four features peaking at 1.98 eV, 2.24 eV, 2.77 eV, and 3.05 eV. The origin of such emissions is related to SiO x intrinsic point defects and to the sulfur doping due to the laser processing. Similar results go in the direction of developing optoelectronic devices suitable for silicon-based circuitry

  14. Characterizing visible and invisible cell wall mutant phenotypes

    Energy Technology Data Exchange (ETDEWEB)

    Carpita, Nicholas C.; McCann, Maureen C.

    2015-04-06

    About 10% of a plant's genome is devoted to generating the protein machinery to synthesize, remodel, and deconstruct the cell wall. High-throughput genome sequencing technologies have enabled a reasonably complete inventory of wall-related genes that can be assembled into families of common evolutionary origin. Assigning function to each gene family member has been aided immensely by identification of mutants with visible phenotypes or by chemical and spectroscopic analysis of mutants with ‘invisible’ phenotypes of modified cell wall composition and architecture that do not otherwise affect plant growth or development. This review connects the inference of gene function on the basis of deviation from the wild type in genetic functional analyses to insights provided by modern analytical techniques that have brought us ever closer to elucidating the sequence structures of the major polysaccharide components of the plant cell wall.

  15. Precoded generalized space shift keying for indoor visible light communications

    KAUST Repository

    Kadampot, Ishaque Ashar

    2014-09-01

    We consider a visible light communication system with 2 transmit light emitting diodes (LED) and nr receive photodiodes. An optical generalized space shift keying modulation scheme is considered for the transmission of bits where each LED can be either in ON state or OFF state at a given time. With this set-up, we design in this paper a precoder for this modulation scheme given the channel state information to improve the bit error rate performance of the system. As conventional precoding techniques for radio frequency at the transmitter cannot be applied to the optical intensity channel, we formulate an optimization problem with constraints for this specific channel. An analytical solution for the precoder is derived and the system performance is compared with and without precoder.

  16. The visibility of non-communicable diseases in northern Uganda

    DEFF Research Database (Denmark)

    Whyte, Susan Reynolds; Park, Sung-Joon; Odong, George

    2015-01-01

    Background : WHO and Uganda’s Ministry of Health emphasize the need to address the growing burden of non-communicable diseases (NCDs). Treatment for these conditions is urgent in northern Uganda where war has negatively affected both health and the public health care system. Objectives : We aimed...... to explore the recognized presence of selected chronic conditions in the out-patient population and to relate this ‘visibility’ to the ability of health units to diagnose and treat them. Methods : At six health facilities we reviewed patient registers for one month to determine the frequency of hypertension...... : The four conditions are relatively invisible in the outpatient population. Greater visibility would be facilitated by regular clinic days for hypertension and diabetes, availability and regular use of diagnostic instruments, and a more reliable supply of the relevant medicines....

  17. Imaging of Biological Tissues by Visible Light CDI

    Science.gov (United States)

    Karpov, Dmitry; Dos Santos Rolo, Tomy; Rich, Hannah; Fohtung, Edwin

    Recent advances in the use of synchrotron and X-ray free electron laser (XFEL) based coherent diffraction imaging (CDI) with application to material sciences and medicine proved the technique to be efficient in recovering information about the samples encoded in the phase domain. The current state-of-the-art algorithms of reconstruction are transferable to optical frequencies, which makes laser sources a reasonable milestone both in technique development and applications. Here we present first results from table-top laser CDI system for imaging of biological tissues and reconstruction algorithms development and discuss approaches that are complimenting the data quality improvement that is applicable to visible light frequencies due to it's properties. We demonstrate applicability of the developed methodology to a wide class of soft bio-matter and condensed matter systems. This project is funded by DOD-AFOSR under Award No FA9550-14-1-0363 and the LANSCE Professorship at LANL.

  18. High-visibility infrared beacons for IFF and combat ID

    Science.gov (United States)

    Pralle, Martin; Puscasu, Irina; Johnson, Edward; Loges, Peter; Melnyk, James

    2005-05-01

    A new kind of Identification Friend or Foe (IFF) infrared beacon has been demonstrated. The omni-directional beacon consists of a pyramidal array of 1W pulsIR thermal light sources. Operating at a total power of 84W, the beacon can be used to track and identify surface vehicles and personnel with a recognition range of up to 6 miles on the battlefield and in urban environments or the marine boundary layer. Advanced photonic technology enables the beacon to be seen only while using a 3-5 μm or 8-12 μm thermal imaging system. There is no visible or near-IR emission to betray the location of the beacon. The beacon is rugged and will operate from -40 to 50°C ambient temperature, 0-100% relative humidity, 0 - 10,000 ft altitude, and meets MIL-STD 810F and MIL-STD 461E.

  19. Status of the Visible Nulling Coronagraph Technology Demonstration Program

    Science.gov (United States)

    Clampin, M.; Lyon, R.

    2012-01-01

    We report on the development, sensing and control of the Vacuum Nuller Testbed to realize a Visible Nulling Coronagraphy (VNC) for exoplanet detection and characterization. The VNC is one of the few approaches that works with filled, segmented and sparse or diluted-aperture telescope systems. It thus spans a range of potential future NASA telescopes and could be flown as a separate instrument on such a future mission. NASA/Goddard Space Flight Center has an established effort to develop VNC technologies, and an incremental sequence of testbeds to advance this approach and its critical technologies. We will highlight results demonstrating the achievement of our TDEM contrast milestones, and highlight the performance of our wavefront sensing and control concept.

  20. Toward visible light response: Overall water splitting using heterogeneous photocatalysts

    KAUST Repository

    Takanabe, Kazuhiro

    2011-01-01

    Extensive energy conversion of solar energy can only be achieved by large-scale collection of solar flux. The technology that satisfies this requirement must be as simple as possible to reduce capital cost. Overall water splitting by powder-form photocatalysts directly produces a mixture of H 2 and O2 (chemical energy) in a single reactor, which does not require any complicated parabolic mirrors and electronic devices. Because of its simplicity and low capital cost, it has tremendous potential to become the major technology of solar energy conversion. Development of highly efficient photocatalysts is desired. This review addresses why visible light responsive photocatalysts are essential to be developed. The state of the art for the photocatalysts for overall water splitting is briefly described. Moreover, various fundamental aspects for developing efficient photocatalysts, such as particle size of photocatalysts, cocatalysts, and reaction kinetics are discussed. Copyright © 2011 De Gruyter.

  1. METIS: the visible and UV coronagraph for solar orbiter

    Science.gov (United States)

    Romoli, M.; Landini, F.; Antonucci, E.; Andretta, V.; Berlicki, A.; Fineschi, S.; Moses, J. D.; Naletto, G.; Nicolosi, P.; Nicolini, G.; Spadaro, D.; Teriaca, L.; Baccani, C.; Focardi, M.; Pancrazzi, M.; Pucci, S.; Abbo, L.; Bemporad, A.; Capobianco, G.; Massone, G.; Telloni, D.; Magli, E.; Da Deppo, V.; Frassetto, F.; Pelizzo, M. G.; Poletto, L.; Uslenghi, M.; Vives, S.; Malvezzi, M.

    2017-11-01

    METIS coronagraph is designed to observe the solar corona with an annular field of view from 1.5 to 2.9 degrees in the visible broadband (580-640 nm) and in the UV HI Lyman-alpha, during the Sun close approaching and high latitude tilting orbit of Solar Orbiter. The big challenge for a coronagraph is the stray light rejection. In this paper after a description of the present METIS optical design, the stray light rejection design is presented in detail together with METIS off-pointing strategies throughout the mission. Data shown in this paper derive from the optimization of the optical design performed with Zemax ray tracing and from laboratory breadboards of the occultation system and of the polarimeter.

  2. A Reversible Photoacid Functioning in PBS Buffer under Visible Light.

    Science.gov (United States)

    Abeyrathna, Nawodi; Liao, Yi

    2015-09-09

    A metastable-state photoacid that can reversibly release a proton in PBS buffer (pH = 7.4) under visible light is reported. The design is based on the dual acid-base property and tautomerization of indazole. The quantum yield was as high as 0.73, and moderate light intensity (10(2) μmol·m(2)·s(-1)) is sufficient for the photoreaction. Reversible pH change of 1.7 units was demonstrated using a 0.1 mM aqueous solution. This type of photoacid is promising for control of proton-transfer processes in physiological conditions and may find applications in biomedical areas.

  3. Navajo Generating Station and Air Visibility Regulations: Alternatives and Impacts

    Energy Technology Data Exchange (ETDEWEB)

    Hurlbut, D. J.; Haase, S.; Brinkman, G.; Funk, K.; Gelman, R.; Lantz, E.; Larney, C.; Peterson, D.; Worley, C.; Liebsch, E.

    2012-01-01

    Pursuant to the Clean Air Act, the U.S. Environmental Protection Agency (EPA) announced in 2009 its intent to issue rules for controlling emissions from Navajo Generating Station that could affect visibility at the Grand Canyon and at several other national parks and wilderness areas. The final rule will conform to what EPA determines is the best available retrofit technology (BART) for the control of haze-causing air pollutants, especially nitrogen oxides. While EPA is ultimately responsible for setting Navajo Generating Station's BART standards in its final rule, it will be the U.S. Department of the Interior's responsibility to manage compliance and the related impacts. This study aims to assist both Interior and EPA by providing an objective assessment of issues relating to the power sector.

  4. Visible light mediated upgrading of biomass to biofuel

    Science.gov (United States)

    AgPd@g-C3N4, comprising heterogenized Ag and Pdnanoparticles on graphitic carbon nitride, g-C3N4, has beensynthesized and used for the upgrading of biofuel as exemplifiedby the hydrodeoxygenation of lignin-derived vanillin underphotochemical conditions using formic acid. The bimetallicframework is found to be highly active due to the synergisticeffects of Ag and Pd with the graphitic carbon nitride support andtheir mutual interaction.This dataset is associated with the following publication:Varma , R., M. Nadagouda , S. Verma, and R.B. Nasir Baig. Visible light mediated upgrading of biomass to biofuel. Energy & Environmental Science. RSC Publishing, Cambridge, UK, 18(5): 1327-1333, (2016).

  5. Nurses' visibility according to the perceptions of the communication professionals.

    Science.gov (United States)

    Kemmer, Ligia Fahl; Paes da Silva, Maria Júlia

    2007-01-01

    This study aimed to further our understanding of the social representations of nurses and the nursing profession by communication professionals, since they are intermediates in the decoding of imaging and written representations about society. this is a qualitative study, based on the social representation theory of Moscovici. Five communication professionals working on radio, television, written press, advertising and events were interviewed. Results suggest 1) ignorance about the nurse's field of work, job market and nursing profession categorization. 2) nurses' invisibility before the media and society and 3) nurse's own responsibility to obtain professional recognition and visibility. Participants in this study pointed two essential processes for building a more coherent image of nursing and nurses: 1) exposing the profession primarily before the media, which ignores its potentialities, and 2) through the media in order to reach the population in general.

  6. Social network in patient safety: Social media visibility

    Directory of Open Access Journals (Sweden)

    Azucena Santillán García

    2011-11-01

    Full Text Available Internet social network (social media is a powerful communication tool, and its use is expanding significantly. This paper seeks to know the current state of visibility in online social networks of active citizen talking about patient safety. This is an observational cross-sectional study whose target population is the websites Facebook, Twitter and Tuenti in Spain. By three consecutive cuts social profiles were found using the searching terms “seguridad+paciente” and “safety+patient”. There were found 5 profiles on Facebook that met the search criteria, 6 on Twitter and none were found on Tuenti. It is concluded that although there is evidence of the rise of social networking, citizen network involved in patient safety appears not to be significantly represented within the social networks examined.

  7. Think tanks in Denmark - Media Visibility and Network Relations

    DEFF Research Database (Denmark)

    Ørsten, Mark; Nørgaard Kristensen, Nete

    and the social democratic think thank the Economic Council of the Labor Movement (ECLM), and their influence on two of the three arenas: the media arena and the administrative arena. Theoretically, we draw on theories of neo-corporatism (Rommetvedt et al., 2012) and mediatization (Hjarvard, 2013; Strömbäck...... & Esser, 2014), and argue that media visibility and attention have become increasingly important for political actors seeking to influence decision makers (Rich & Weaver, 2000), but that corporatist networks and access to the administrative sphere are also still important arenas of influence (Binderkrantz...... have necessitated that actors seeking to influence political decisions mak-ing, such as interest groups, have had to find new ways of influencing policy making (Rom-metvedt et al., 2012). Studies of special interest groups in Denmark have pointed towards three important arenas of influence...

  8. Visible Light Communications (VLC) for Ambient Assisted Living

    DEFF Research Database (Denmark)

    Kumar, Ambuj; Mihovska, Albena D.; Kyriazakos, Sofoklis

    2014-01-01

    and a conceptual supporting architecture for its deployment. Further, the technical challenges and possible roadmap for the actual deployment are analyzed for the particular case of an eHealth scenario where the utilization of VLC technology is the enabler of the costefficient rollout of the required...... (WLANs) can take upon part of the indoor traffic, the ever increasing demand for such data, and users, calls for either use of licensed or novel unlicensed wireless communication technologies as part of the smart home enablers. This paper focuses on the potentials of visible light communications (VLC......), jointly with radio and fiber communications, to support very dense low and high data rate connectivity, while enabling deployment of secure-sensitive indoor applications, including indoor tracking and localization. The paper proposes a scenario for integrating VLC into the smart home scenario...

  9. Network coding multiuser scheme for indoor visible light communications

    Science.gov (United States)

    Zhang, Jiankun; Dang, Anhong

    2017-12-01

    Visible light communication (VLC) is a unique alternative for indoor data transfer and developing beyond point-to-point. However, for realizing high-capacity networks, VLC is facing challenges including the constrained bandwidth of the optical access point and random occlusion. A network coding scheme for VLC (NC-VLC) is proposed, with increased throughput and system robustness. Based on the Lambertian illumination model, theoretical decoding failure probability of the multiuser NC-VLC system is derived, and the impact of the system parameters on the performance is analyzed. Experiments demonstrate the proposed scheme successfully in the indoor multiuser scenario. These results indicate that the NC-VLC system shows a good performance under the link loss and random occlusion.

  10. Influencing factors on the visibility of surface distresses

    Science.gov (United States)

    Smęt, Wojciech; Skakuj, Marek

    2018-05-01

    A systematic and future-oriented maintenance management requires quality-assured data regarding the condition of the roadway. An important characteristic for assessing the condition of the road surface are cracks [1]. Experience has proven that the road surface temperature and residual humidity can influence the visibility of cracks. To investigate and quantify these influencing factors in more detail, the Federal Ministry of Transport and Digital Infrastructure has implemented a comprehensive research project [2], during which several measurement campaigns were carried out at different seasons and at different temperatures and humidity degrees of the road surface. The visibility of the cracks was assessed using the German approach ZTV ZEB-StB [3]. After evaluating the cracks, the data was synchronized and the network allocation of the geo-referenced raw data was realized. The relevant condition performance indicators were calculated subsequently. For each evaluation section of 100 meters length, the mean road surface temperature was calculated and, if available, the type and year of construction of the surface course was determined. The evaluated data was visualized to establish correlations between the data and the influencing factors. For the statistical analysis of the results, a total of six comparative scenarios were defined in which the influencing factors of road surface temperature and residual humidity were assessed. This paper documents the results of the research project. In order to obtain a uniform and comparable picture of the condition of the road surface over the years and thus to be able to observe the aging process of the road surface, the measurement campaigns are to be carried out under defined conditions. The research project included proposals for defining and further specifying the measurement conditions.

  11. Visibility and surveillance regime in the age of Digital Identity

    Directory of Open Access Journals (Sweden)

    María Alejandra López Gabrielidis

    2015-12-01

    Full Text Available This article addresses the link between the hypervisibility regime in which the contemporary subject is immersed in and the new forms of surveillance. Based on an analysis of the work of Hito Steyerl How Not to be Seen: A Fucking Didactic Educational .MOV File (2013 we explore the changes suffered by the traditional form of surveillance with a special highlight on the current features of the cyber-surveillance device. The 21st century is witnessing a socio-technical phenomenon which transforms the subject into an image-data, as a result of what Paul Virilio calls the industrialization and proliferation of “visual machines” (photographic cameras, microscopes, telescopes, drones, the social online habits which tend to self-capture and self-diffusion, and the processes of datification. Nowadays, the subject assumes an active role in the surveillance mechanisms and, hence, is partly responsible of the control that is practiced over him. In this video, Hito Steyerl teaches us about camouflage techniques, confusion and low resolution uses, in order to be less visible before the eyes of the power. However, the excess of visibility and exposure of the subject seems to be a highly difficult situation to counteract in the technical conditions that we live in. As we propose in the last section of the article, in order to solve the surveillance problems in the digital age it is necessary to redefine the concept of privacy starting from the concept of digital identity, with all its implications. Consequently, we must lead the way into new forms of legal authority over data.

  12. Visibility of sutures of the orbit and periorbital region using multidetector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Gufler, Hubert; Preis, Markus; Koesling, Sabrina [Dept. of Diagnostic Radiology, Martin-Luther-University Halle-Wittenberg, Halle (Germany)

    2014-12-15

    Knowledge of cranial suture morphology is crucial in emergency medicine, forensic medicine, and maxillofacial reconstructive surgery. This study assessed the visibility of sutures of the orbit and periorbital region on multidetector computed tomography. Multidetector computed tomography scans of 200 patients (127 males, 73 females; mean age 51.3 years; range, 6-92 years) were evaluated retrospectively. The slice thicknesses varied from 0.5 to 1 mm, and the tube current from 25 to 370 mAs, depending on the CT indication. The visibility of sutures was estimated according to a 4-point scale from 'not visible to well visible' The chi-squared test was used to test the association of the visibility of sutures with the slice thickness, tube current, and age of patients. Statistical significance was assumed at p < 0.05. Overall, best visibility was found for the sutura frontozygomatica (98%), sutura frontonasalis (88.5%), and sutura sphenozygomatica (71.5%), followed by the sutura zygomaticomaxillaris (65.8%), sutura temporozygomatica (41.8%), sutura frontomaxillaris (44.5%), and sutura sphenofrontalis (31%). Poor visibility was found for the sutura frontolacrimalis (16.8%) and sutura frontoethmoidalis (1.3%). The sutura ethmoidomaxillaris, sutura lacrimomaxillaris, and sutura ethmoidolacrimalis were not visible. Although the sutures of the superior, lateral, and inferior orbit are well visible, those of the medial orbit are poorly visible on CT scans.

  13. Disparity in Cutaneous Pigmentary Response to LED vs Halogen Incandescent Visible Light: Results from a Single Center, Investigational Clinical Trial Determining a Minimal Pigmentary Visible Light Dose.

    Science.gov (United States)

    Soleymani, Teo; Cohen, David E; Folan, Lorcan M; Okereke, Uchenna R; Elbuluk, Nada; Soter, Nicholas A

    2017-11-01

    Background: While most of the attention regarding skin pigmentation has focused on the effects of ultraviolet radiation, the cutaneous effects of visible light (400 to 700nm) are rarely reported. The purpose of this study was to investigate the cutaneous pigmentary response to pure visible light irradiation, examine the difference in response to different sources of visible light irradiation, and determine a minimal pigmentary dose of visible light irradiation in melanocompetent subjects with Fitzpatrick skin type III - VI. The study was designed as a single arm, non-blinded, split-side dual intervention study in which subjects underwent visible light irradiation using LED and halogen incandescent light sources delivered at a fluence of 0.14 Watts/cm2 with incremental dose progression from 20 J/cm2 to 320 J/cm2. Pigmentation was assessed by clinical examination, cross-polarized digital photography, and analytic colorimetry. Immediate, dose-responsive pigment darkening was seen with LED light exposure in 80% of subjects, beginning at 60 Joules. No pigmentary changes were seen with halogen incandescent light exposure at any dose in any subject. This study is the first to report a distinct difference in cutaneous pigmentary response to different sources of visible light, and the first to demonstrate cutaneous pigment darkening from visible LED light exposure. Our findings raise the concern that our increasing daily artificial light surroundings may have clandestine effects on skin biology. J Drugs Dermatol. 2017;16(11):1105-1110..

  14. The Influence of Visibility Conditions in Horizontal Road Curves on the Efficiency of Noise Protection Barriers

    Directory of Open Access Journals (Sweden)

    Džambas Tamara

    2013-12-01

    Full Text Available Ensuring sufficient visibility on planned roads by sight distance testing is an integral part of every project, but problems with visibility can emerge when noise barriers are erected on existing roads. Namely, in order to provide sufficient noise protection, high noise barriers are often placed at minimum distance from the carriageway edge, and additional visibility testing in most cases is not carried out.

  15. UV Blocking Glass: Low Cost Filters for Visible Light Photocatalytic Assessment

    OpenAIRE

    Dunnill, Charles W.

    2014-01-01

    A number of commercially available art protection products have been compared and assessed for their suitability as UV blocking filters in the application of “visible light” photocatalytic research. Many groups claiming visible light photocatalytic success employ filters to block out stray UV radiation in order to justify that their photocatalysts are indeed visible light photocatalysts and not UV light photocatalysts. These filters come in varying degrees of ability and price and many author...

  16. Visibility Aspects Importance of User Interface Reception in Cloud Computing Applications with Increased Automation

    OpenAIRE

    Haxhixhemajli, Denis

    2012-01-01

    Visibility aspects of User Interfaces are important; they deal with the crucial phase of human-computer interaction. They allow users to perform and at the same time hide the complexity of the system. Acceptance of new systems depends on how visibility aspects of the User Interfaces are presented. Human eyes make the first contact with the appearance of any system by so it generates the very beginning of the human – application interaction. In this study it is enforced that visibility aspects...

  17. Visibility of mandibular canal on panoramic radiograph after bilateral sagittal split osteotomy (BSSO).

    OpenAIRE

    Politis, Constantinus; Ramirez, Xiomara Botero; Sun, Yi; Lambrichts, Ivo; Heath, Neil; Agbaje, Jimoh Olubanwo

    2013-01-01

    PURPOSE: This study aimed to assess the visibility of the mandibular canal (MC) on panoramic radiographs after bilateral sagittal split osteotomy (BSSO), and to investigate what factors affect this MC visibility. METHODS: We assessed MC visibility on panoramic radiographs of 200 BSSO patients. Images were acquired preoperatively (T0), immediately postoperatively (T1), 6 months postoperatively (T2), and 1 year postoperatively (T3), from three diffe...

  18. A Study on Visibility Rating of Several Representative Web-Safe Colors

    Science.gov (United States)

    Saito, Daisuke; Saito, Keiichi; Notomi, Kazuhiro; Saito, Masao

    This paper presents the visibility ordering of several web-safe colors. The research of web site visibility is important because of the rapid dissemination of the World Wide Web. The combination of a foreground color and a background color is an important factor in providing sufficient visibility. Therefore, the rating of color combination visibility is necessary when developing accessible web sites. In this study, the visibility of several web-safe color combinations was examined using psychological methodology, i.e., a paired comparison. Eighteen chromatic web-safe colors were employed for visual stimuli. Nine students ranging from ages 21 to 29 (average 23.7) were recruited, and all were with normal color sensation. These nine subjects looked at two different colored characters simultaneously on the white background and were instructed to identify which one enabled them to see more clearly. In examining the relationship between the psychological rankings of the color combinations and the visual sensations, each color combination was first scored as to the visibility by Thurstone's paired comparisons technique. Secondly, the visual sensation was deduced by applying Weber-Fechner's law to the luminance of the foreground colors. As results, the luminance of a foreground color influenced the visibility; however the visibility rating is difficult only using the luminance of web-safe colors. These indicate that the chromaticity and chroma saturation are necessary in rating of chromatic web-safe color visibility.

  19. A Study on Visibility Estimation of Web-Safe Colors using Paired Comparison and Discriminant Analysis

    Science.gov (United States)

    Saito, Daisuke; Saito, Keiichi; Notomi, Kazuhiro; Saito, Masao

    This paper presents the visibility ordering of several web safe colors. The research of web page visibility is important because of the rapid dissemination of the World Wide Web. The combination of a foreground color and a background color is an important factor in providing sufficient visibility. Therefore, the rating of color combination visibility is necessary when developing accessible web sites. In this study, the visibility of several web-safe color combinations was examined using psychological methodology, i.e., paired comparison. Eighteen chromatic and 3 achromatic web-safe colors were employed for visual stimuli. Twenty-eight subjects ranging from ages 21 to 75 were recruited, and all were with normal color sensation. They looked at two different colored characters simultaneously on the white background and were instructed to identify which one enabled them to see more clearly. In examining the relationship between the psychological rankings of the color combinations and the visual sensations, each color combination was first scored as to the visibility by Thurstone's paired comparison technique. Secondly, the visual sensation was deduced by applying Weber-Fechner's law to the luminance of the foreground colors. As results, the luminance of a foreground color influenced the visibility; however the visibility rating is difficult only using the luminance of web-safe colors. These indicate that the chromaticity and chroma saturation are necessary in rating of chromatic web-safe color visibility.

  20. A Study of Visible Tattoos in Entry-Level Dental Hygiene Education Programs.

    Science.gov (United States)

    Search, Kathryn R; Tolle, Susan L; McCombs, Gayle B; Arndt, Aaron

    2018-02-01

    Purpose: The purpose of this study was to survey entry-level dental hygiene program directors in the United States (U.S.) to assess their perceptions of dental hygienists with visible tattoos as well as to determine current policies related to dress codes in U.S. dental hygiene programs. Methods: Data was collected with an online survey emailed to 340 dental hygiene program directors yielding a 43% (n=141) response rate. Participants indicated their opinions of visible tattoos on the basis of professionalism and school policy satisfaction. Results: Eighty percent of respondents reported their program as having dress code policies on visible tattoos, with the majority (97%) requiring visible tattoos to be covered. Results revealed both students (M=5.57, phygiene faculty should discuss the impact of visible tattoos on future employment opportunities, and that the community would view the school as less professional if students had visible tattoos (pPersonal tolerance toward tattoos (phygiene program dress code included policy on visible tattoos. Conclusion: Study results showed that visible tattoos were not perceived favorably and that personal perceptions of dental hygiene program directors may have influenced school dress code polices regarding visible tattoos. These findings provide evidence based information for dental hygienists, students, faculty, administrators and hiring managers for formulating policies relating to body art. Copyright © 2018 The American Dental Hygienists’ Association.

  1. Measurements of impurity spectra using UV/visible spectroscopic system in a GAMMA 10 plasma

    International Nuclear Information System (INIS)

    Matama, K.; Yoshikawa, M.; Kobayashi, T.; Kubota, Y.; Cho, T.

    2006-01-01

    Impurity spectra have been measured and identified using a newly designed ultraviolet and visible (UV/visible) spectroscopic system in the tandem mirror GAMMA 10. It is constructed using two spectrometers to obtain an entire wavelength range of UV/visible impurity spectra with a high wavelength resolution in one plasma shot. We successfully obtained the emission intensities of the radiation spectra in detail and information on the time-varying population densities of the impurities. We evaluate radiation loss from the GAMMA 10 plasma in the UV/visible range; further we estimate the electron density and temperature after applying the measured spectral intensity to a collisional-radiative model

  2. Coping behavior of women with breast cancer with visible postsurgery deformity

    Directory of Open Access Journals (Sweden)

    Sirota N. A.

    2013-01-01

    Full Text Available Research was carried out to explore coping strategies in cancer patients. In all, 70 women with breast cancer were studied: 35 of them had visible postsurgery deformity, and 35 did not have visible postsurgery deformity. The purpose of the research was to uncover their preferences for using various strategies and resources to cope with their illness. The results showed that both groups of women had a special set of strategies for coping with stress. The women with visible postsurgery deformity made significantly less use of resources for coping with their illness than did the subgroup of women without visible postsurgery deformity.

  3. Preparation of sensitized ZnS and its photocatalytic activity under visible light irradiation

    International Nuclear Information System (INIS)

    Zhang Haitao; Chen Xinyi; Li Zhaosheng; Kou Jiahui; Yu Tao; Zou Zhigang

    2007-01-01

    In this paper, sensitized ZnS with visible light driven photocatlytic ability was successfully prepared. The obtained ZnS was characterized by x-ray diffraction, UV-visible diffuse reflectance spectra and Fourier transform infrared spectra. The photocatalytic property of the prepared ZnS was evaluated by decomposing methyl orange (MO). These sensitized ZnS powders with a proper molar ratio showed higher photocatalytic activity than TiO 2 (P25) under visible light (λ > 420 nm) irradiation. A possible explanation for the visible light activity of the prepared ZnS was proposed

  4. Visible Light Induces Melanogenesis in Human Skin through a Photoadaptive Response

    Science.gov (United States)

    Randhawa, Manpreet; Seo, InSeok; Liebel, Frank; Southall, Michael D.; Kollias, Nikiforos; Ruvolo, Eduardo

    2015-01-01

    Visible light (400–700 nm) lies outside of the spectral range of what photobiologists define as deleterious radiation and as a result few studies have studied the effects of visible light range of wavelengths on skin. This oversight is important considering that during outdoors activities skin is exposed to the full solar spectrum, including visible light, and to multiple exposures at different times and doses. Although the contribution of the UV component of sunlight to skin damage has been established, few studies have examined the effects of non-UV solar radiation on skin physiology in terms of inflammation, and limited information is available regarding the role of visible light on pigmentation. The purpose of this study was to determine the effect of visible light on the pro-pigmentation pathways and melanin formation in skin. Exposure to visible light in ex-vivo and clinical studies demonstrated an induction of pigmentation in skin by visible light. Results showed that a single exposure to visible light induced very little pigmentation whereas multiple exposures with visible light resulted in darker and sustained pigmentation. These findings have potential implications on the management of photo-aggravated pigmentary disorders, the proper use of sunscreens, and the treatment of depigmented lesions. PMID:26121474

  5. Study on the visibility of an electroluminescent display for automobiles; Jidoshayo EL display no shininsei

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, N; Harada, M; Idogaki, T [Denso Corp., Aichi (Japan)

    1997-10-01

    This report explores the visibility of an Electroluminescent (EL) display for automotive use. Displays for automobiles are exposed to the direct rays of the sun and forced to operate in wide temperature range. Therefore, luminous flux density by the lighting on EL display panel and operating environment temperature must be considered for the visibility evaluation. Sensory evaluation on the visibility and physical measurements such as contrast, chromaticity difference in accordance with the viewing angle change indicate that the visibility of the EL display for automobiles is advantageous over other displays. 6 refs., 11 figs., 1 tab.

  6. Visible Light Induces Melanogenesis in Human Skin through a Photoadaptive Response.

    Science.gov (United States)

    Randhawa, Manpreet; Seo, InSeok; Liebel, Frank; Southall, Michael D; Kollias, Nikiforos; Ruvolo, Eduardo

    2015-01-01

    Visible light (400-700 nm) lies outside of the spectral range of what photobiologists define as deleterious radiation and as a result few studies have studied the effects of visible light range of wavelengths on skin. This oversight is important considering that during outdoors activities skin is exposed to the full solar spectrum, including visible light, and to multiple exposures at different times and doses. Although the contribution of the UV component of sunlight to skin damage has been established, few studies have examined the effects of non-UV solar radiation on skin physiology in terms of inflammation, and limited information is available regarding the role of visible light on pigmentation. The purpose of this study was to determine the effect of visible light on the pro-pigmentation pathways and melanin formation in skin. Exposure to visible light in ex-vivo and clinical studies demonstrated an induction of pigmentation in skin by visible light. Results showed that a single exposure to visible light induced very little pigmentation whereas multiple exposures with visible light resulted in darker and sustained pigmentation. These findings have potential implications on the management of photo-aggravated pigmentary disorders, the proper use of sunscreens, and the treatment of depigmented lesions.

  7. Visible Light Induces Melanogenesis in Human Skin through a Photoadaptive Response.

    Directory of Open Access Journals (Sweden)

    Manpreet Randhawa

    Full Text Available Visible light (400-700 nm lies outside of the spectral range of what photobiologists define as deleterious radiation and as a result few studies have studied the effects of visible light range of wavelengths on skin. This oversight is important considering that during outdoors activities skin is exposed to the full solar spectrum, including visible light, and to multiple exposures at different times and doses. Although the contribution of the UV component of sunlight to skin damage has been established, few studies have examined the effects of non-UV solar radiation on skin physiology in terms of inflammation, and limited information is available regarding the role of visible light on pigmentation. The purpose of this study was to determine the effect of visible light on the pro-pigmentation pathways and melanin formation in skin. Exposure to visible light in ex-vivo and clinical studies demonstrated an induction of pigmentation in skin by visible light. Results showed that a single exposure to visible light induced very little pigmentation whereas multiple exposures with visible light resulted in darker and sustained pigmentation. These findings have potential implications on the management of photo-aggravated pigmentary disorders, the proper use of sunscreens, and the treatment of depigmented lesions.

  8. Visible Thinking: Application And Evaluation Of Thinking Routines In Primary Education

    OpenAIRE

    Parada Rodríguez, Nerea; Ruiz de Galarreta Galán, Irene

    2015-01-01

    Producción Científica En el año 1967 Nelson Goodman, con el objetivo de entender y mejorar el aprendizaje, fundó Project Zero, grupo de investigación educativa compuesto por diversos proyectos de investigación entre los cuales se encuentra el proyecto Visible Thinking. Visible Thinking nació en el año 2005 tras años de investigaciones sobre el pensamiento de los niños y su aprendizaje. La idea central del proyecto Visible Thinking es la de hacer visible el pensamiento, ya...

  9. "YouTube Geology" - Increasing Geoscience Visibility Through Short Films

    Science.gov (United States)

    Piispa, E. J.; Lerner, G. A.

    2016-12-01

    Researchers have the responsibility to communicate their science to a broad audience: scientists, non-scientist, young and old. Effective ways of reaching these groups include using pathways that genuinely spark interest in the target audience. Communication techniques should evolve as the means of communication evolve. Here we talk about our experiences using short films to increase geoscience visibility and appreciation. At a time when brevity and quick engagement are vital to capturing people's attention, creating videos that fit popular formats is an effective way to draw and hold people's interest, and spreading these videos on popular sites is a good way to reach a non-academic audience. Creating videos that are fun, exciting, and catchy in order to initially increase awareness and interest is equally important as the educational content. The visual medium can also be powerful way to make complex scientific concepts seem less intimidating. We have experimented with this medium of geoscience communication by creating a number of short films that target a variety of audiences: short summaries of research topics, mock movie trailers, course advertisements, fieldwork highlight reels and geology lessons for elementary school children. Our two rules of thumb are to put the audience first and use style as a vital element. This allows for the creation of films that are more engaging and often less serious than standard informational (and longer-format) videos. Science does not need to be dry and dull - it can be humorous and entertaining while remaining highly accurate. Doing these short films has changed our own mindset as well - thinking about what to film while doing research helps keep the practical applications of our research in focus. We see a great deal of potential for collaboration between geoscientists and amateur or professional filmmakers creating hip and edgy videos that further raise awareness and interest. People like movies. We like movies. We like

  10. Final Report: Non-Visible, Automated Target Acquisition and Tracking

    Energy Technology Data Exchange (ETDEWEB)

    Ziock, Klaus-Peter [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Fabris, Lorenzo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Goddard, James K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hornback, Donald Eric [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Karnowski, Thomas Paul [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Newby, Jason [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-10-01

    The Roadside Tracker (RST) represents a new approach to radiation portal monitors. It uses a combination of gamma-ray and visible-light imaging to localize gamma-ray radiation sources to individual vehicles in free-flowing, multi-lane traffic. Deployed as two trailers that are parked on either side of the roadway (Fig. 1); the RST scans passing traffic with two large gamma-ray imagers, one mounted in each trailer. The system compensates for vehicle motion through the imager’s fields of view by using automated target acquisition and tracking (TAT) software applied to a stream of video images. Once a vehicle has left the field of view, the radiation image of that vehicle is analyzed for the presence of a source, and if one is found, an alarm is sounded. The gamma-ray image is presented to the operator together with the video image of the traffic stream when the vehicle was approximately closest to the system (Fig. 2). The offending vehicle is identified with a bounding box to distinguish it from other vehicles that might be present at the same time. The system was developed under a previous grant from the Department of Homeland Security’s (DHS’s) Domestic Nuclear Detection Office (DNDO). This report documents work performed with follow-on funding from DNDO to further advance the development of the RST. Specifically, the primary thrust was to extend the performance envelope of the system by replacing the visible-light video cameras used by the TAT software with sensors that would allow operation at night and during inclement weather. In particular, it was desired to allow operation after dark without requiring external lighting. As part of this work, the system software was also upgraded to allow the use of 64-bit computers, the current generation operating system (OS), software development environment (Windows 7 vs. Windows XP, and current Visual Studio.Net), and improved software version controls (GIT vs. Source Safe.) With the upgraded performance allowed by

  11. The visible spectrum of Pluto: secular and longitudinal variation

    Science.gov (United States)

    Lorenzi, Vania; Pinilla-Alonso, Noemí; Emery, Joshua P.; Licandro, Javier; Cruikshank, Dale P.; Grundy, Will; Binzel, Richard P.

    2015-11-01

    Continuous near-infrared spectroscopic observations during the last 30 years enabled the characterization of the Pluto's surface and the study of its variability. Nevertheless, only few data are available in the visible range, where the nature of the complex-organics can be studied.For this reason, we started an observational campaign to obtain the Pluto's relative reflectance in the visible range, with the aim of characterizing the different components of its surface, and providing ground based observations in support of the New Horizons mission. We observed Pluto on six nights in 2014, with the imager/spectrograph ACAM@WHT (La Palma, Spain). We obtained six spectra in the 0.40 - 0.93 µm range, that covered a whole Pluto's rotational period (6.4 days).To study longitudinal variations, we computed for all the spectra the spectral slope, and the position and the depth of the methane ice absorption bands. Also, to search for secular or seasonal variations we compared our data with previously published results.All the spectra present a red slope, indicating the presence of complex organics on Pluto's surface, and show the methane ice absorption bands between 0.73 and 0.90 μm. We also report the detection of the CH4 absorption band at 0.62 μm, already detected in the spectra of Makemake and Eris. The measurement of the band depth at 0.62 μm in the new spectra of Pluto, and in the spectra of Makemake and Eris, permits us to estimate the Lambert coefficient, not measured yet at this wavelength, at a temperature of 30 K and 40 K.We find that all the CH4 bands present a blue shift. This shift is minimum at the Charon-facing hemisphere, where the CH4 is also more abundant, indicating a higher degree of saturation of CH4 in the CH4:N2 dilution at this hemisphere.Comparing with data in the literature, we found that the longitudinal and secular variations of the parameters measured in our spectra are in accordance with previous results and with the distribution of the dark

  12. Photooxidation of anthracene under visible light with metallocarboxyphenylporphyrins

    Directory of Open Access Journals (Sweden)

    Carlos Enrique Díaz-Uribe

    2014-01-01

    Full Text Available En este trabajo sintetizamos metalocarboxifenilporfirinas (TcPP-M, M= Cu y Zn y la carboxifenilporfirina libre de metal (TcPPH y determinamos su eficiencia en la fotooxidación de antraceno bajo luz visible a través de la generación de oxígeno singulete ( 1 O 2 . La presencia de 1 O 2 fue evidenciada por Resonancia Paramagnética Electrónica (RPE, el cual el oxígeno singulete reacciona con la 2,2,6,6-tetrametil-4-piperidona-N (TEMP para producir el radical 2,2,6,6-tetrametil-4-piperidona-N-oxil (TEMPO. Los resultados catalíticos indican que la incorporación del metal en el anillo de la porfirina afecta su eficiencia sobre la oxidación del antraceno. La TcPPH mostró la eficiencia fotónica más alta en la conversión de antraceno (31 % en comparación con la TcPPZn (13 % y TcPPCu (9 %. Estos resultados pueden ser relacionados a la distorsión de la planaridad del anillo de porfirina. Finalmente se detectó la formación de antraquinona y oxoantrona como productos de oxidación in la reacción del antraceno con 1 O 2.

  13. Portable visible and near-infrared spectrophotometer for triglyceride measurements.

    Science.gov (United States)

    Kobayashi, Takanori; Kato, Yukiko Hakariya; Tsukamoto, Megumi; Ikuta, Kazuyoshi; Sakudo, Akikazu

    2009-01-01

    An affordable and portable machine is required for the practical use of visible and near-infrared (Vis-NIR) spectroscopy. A portable fruit tester comprising a Vis-NIR spectrophotometer was modified for use in the transmittance mode and employed to quantify triglyceride levels in serum in combination with a chemometric analysis. Transmittance spectra collected in the 600- to 1100-nm region were subjected to a partial least-squares regression analysis and leave-out cross-validation to develop a chemometrics model for predicting triglyceride concentrations in serum. The model yielded a coefficient of determination in cross-validation (R2VAL) of 0.7831 with a standard error of cross-validation (SECV) of 43.68 mg/dl. The detection limit of the model was 148.79 mg/dl. Furthermore, masked samples predicted by the model yielded a coefficient of determination in prediction (R2PRED) of 0.6856 with a standard error of prediction (SEP) and detection limit of 61.54 and 159.38 mg/dl, respectively. The portable Vis-NIR spectrophotometer may prove convenient for the measurement of triglyceride concentrations in serum, although before practical use there remain obstacles, which are discussed.

  14. Perovskite Nanocrystals as a Color Converter for Visible Light Communication

    KAUST Repository

    Dursun, Ibrahim; Shen, Chao; Parida, Manas R.; Pan, Jun; Sarmah, Smritakshi P.; Priante, Davide; AlYami, Noktan; Liu, Jiakai; Saidaminov, Makhsud I.; Alias, Mohd Sharizal; Abdelhady, Ahmed L.; Ng, Tien Khee; Mohammed, Omar F.; Ooi, Boon S.; Bakr, Osman

    2016-01-01

    Visible light communication (VLC) is an emerging technology that uses light-emitting diodes (LEDs) or laser diodes for simultaneous illumination and data communication. This technology is envisioned to be a major part of the solution to the current bottlenecks in data and wireless communication. However, the conventional lighting phosphors that are typically integrated with LEDs have limited modulation bandwidth and thus cannot provide the bandwidth required to realize the potential of VLC. In this work, we present a promising light converter for VLC by designing solution-processed CsPbBr3 perovskite nanocrystals (NCs) with a conventional red phosphor. The fabricated CsPbBr3 NCs phosphor-based white light converter exhibits an unprecedented modulation bandwidth of 491 MHz, which is ~ 40 times greater than that of conventional phosphors, and the capability to transmit a high data rate of up to 2 Gbit/s. Moreover, this perovskite enhanced white light source combines ultrafast response characteristics with a high color rendering index of 89 and a low correlated color temperature of 3236 K, thereby enabling dual VLC and solid-state lighting functionalities.

  15. Prolegomenon for an ethics of visibility in Hannah Arendt

    Directory of Open Access Journals (Sweden)

    Bethânia Assy

    Full Text Available This paper aims to discuss the Arendtian notions of appearance and perception in order to promote a displacement of those conceptions from the generally associated domain of passive apprehension of the faculty of knowledge towards the domain of a praxiology of action and language, based on an active perception. Arendt's appropriations on the Heideggerian "to take one's place" (sich hin-stellen will be discussed, as well as the Augustinian "finding oneself in the world" (diligere. A twofold disposition of appearance will be distinguished: producing and position, whose transposed to the Arendtian notion of world correspond, respectively, to fabrication (poiesis of the world, man's objective in-between space, and to action (praxis in the world, man's subjective in-between space. Those conceptual replacements, in a broad sense, uphold a closer imbrication between the activities of the mind and acting, stricto sensu, and consequently, foment not only the valorization of the public space, but the visibility of our acts and deeds as well, calling out the dignity of appearance in ethics.

  16. Mobile User Connectivity in Relay-Assisted Visible Light Communications

    Directory of Open Access Journals (Sweden)

    Petr Pešek

    2018-04-01

    Full Text Available In this paper, we investigate relay-assisted visible light communications (VLC where a mobile user acts as a relay and forwards data from a transmitter to the end mobile user. We analyse the utilization of the amplify-and-forward (AF and decode-and-forward (DF relaying schemes. The focus of the paper is on analysis of the behavior of the mobile user acting as a relay while considering a realistic locations of the receivers and transmitters on a standard mobile phone, more specifically with two photodetectors on both sides of a mobile phone and a transmitting LED array located upright. We also investigate dependency of the bit error rate (BER performance on the azimuth and elevation angles of the mobile relay device within a typical office environment. We provide a new analytical description of BER for AF and DF-based relays in VLC. In addition we compare AF and DF-based systems and show that DF offers a marginal improvement in the coverage area with a BER < 10–3 and a data rate of 100 Mb/s. Numerical results also illustrate that relay-based systems offer a significant improvement in terms of the coverage compared to direct non-line of sight VLC links.

  17. Sputtering measurements on JET using a multichannel visible spectrometer

    International Nuclear Information System (INIS)

    Stamp, M.F.; Morgan, P.D.; Summers, H.P.

    1989-01-01

    A multichannel visible spectrometer has been used on JET to simultaneously observe the emission from D, H, C and O atoms and ions in the proximity of a belt limiter. The absolute intensity of the line emission, along with a Langmuir probe measurement of the edge electron temperature and an atomic physics model, allows us to calculate the influxes of these species. Under steady-state conditions the influxes of D and He are the same as the effluxes, so the ratio of impurity to fuel fluxes, e.g. carbon to deuterium, is the apparent sputtering yield of deuterium on carbon in the tokamak environment. The measured flux ratio Γ c /Γ D is also indicative of the central carbon impurity concentration in JET, because the limiters are the main source of impurities. For similar particle transport, Γ c /Γ D =n c (o)/n D (o), so for a 10% flux ratio, n c /n e =6.6%, Z eff =3. (author) 7 refs., 5 figs

  18. Indian English Evolution and Focusing Visible Through Power Laws

    Directory of Open Access Journals (Sweden)

    Vineeta Chand

    2017-11-01

    Full Text Available New dialect emergence and focusing in language contact settings is difficult to capture and date in terms of global structural dialect stabilization. This paper explores whether diachronic power law frequency distributions can provide evidence of dialect evolution and new dialect focusing, by considering the quantitative frequency characteristics of three diachronic Indian English (IE corpora (1970s–2008. The results demonstrate that IE consistently follows power law frequency distributions and the corpora are each best fit by Mandelbrot’s Law. Diachronic changes in the constants are interpreted as evidence of lexical and syntactic collocational focusing within the process of new dialect formation. Evidence of new dialect focusing is also visible through apparent time comparison of spoken and written data. Age and gender-separated sub-corpora of the most recent corpus show minimal deviation, providing apparent time evidence for emerging IE dialect stability. From these findings, we extend the interpretation of diachronic changes in the β coefficient—as indicative of changes in the degree of synthetic/analytic structure—so that β is also sensitive to grammaticalization and changes in collocational patterns.

  19. Reactor safety research - visible demonstrations and credible computations

    Energy Technology Data Exchange (ETDEWEB)

    Loewenstein, W B; Divakaruni, S M

    1985-11-01

    EPRI has been conducting nuclear safety research for a number of years with the primary goal of assuring the safety and reliability of the nuclear plants. The visibility is emphasized by sponsoring or participating in large scale test demonstrations to credibly support the complex computations that are the basis for quantification of safety margins. Recognizing the success of the airline industry in receiving favorable public perception, the authors compare the design and operation practices of the airline industry with those of the nuclear industry practices to identify the elements contributing to public concerns and unfavorable perceptions. In this paper, authors emphasize the importance of proper communications of research results to the public in a manner that non-specialists understand. Further, EPRI supported research and results in the areas of source term, seismic and structural engineering research, analysis using probabilistic risk assessment (PRA), quantification of safety margins, digital technology development and implementation, and plant transient and performance evaluations are discussed in the paper. (orig./HP).

  20. Cooling atomic ions with visible and infra-red light

    Science.gov (United States)

    Lindenfelser, F.; Marinelli, M.; Negnevitsky, V.; Ragg, S.; Home, J. P.

    2017-06-01

    We demonstrate the ability to load, cool and detect singly charged calcium ions in a surface electrode trap using only visible and infrared lasers for the trapped-ion control. As opposed to the standard methods of cooling using dipole-allowed transitions, we combine power broadening of a quadrupole transition at 729 nm with quenching of the upper level using a dipole allowed transition at 854 nm. By observing the resulting 393 nm fluorescence we are able to perform background-free detection of the ion. We show that this system can be used to smoothly transition between the Doppler cooling and sideband cooling regimes, and verify theoretical predictions throughout this range. We achieve scattering rates which reliably allow recooling after collision events and allow ions to be loaded from a thermal atomic beam. This work is compatible with recent advances in optical waveguides, and thus opens a path in current technologies for large-scale quantum information processing. In situations where dielectric materials are placed close to trapped ions, it carries the additional advantage of using wavelengths which do not lead to significant charging, which should facilitate high rate optical interfaces between remotely held ions.

  1. Accelerated speckle imaging with the ATST visible broadband imager

    Science.gov (United States)

    Wöger, Friedrich; Ferayorni, Andrew

    2012-09-01

    The Advanced Technology Solar Telescope (ATST), a 4 meter class telescope for observations of the solar atmosphere currently in construction phase, will generate data at rates of the order of 10 TB/day with its state of the art instrumentation. The high-priority ATST Visible Broadband Imager (VBI) instrument alone will create two data streams with a bandwidth of 960 MB/s each. Because of the related data handling issues, these data will be post-processed with speckle interferometry algorithms in near-real time at the telescope using the cost-effective Graphics Processing Unit (GPU) technology that is supported by the ATST Data Handling System. In this contribution, we lay out the VBI-specific approach to its image processing pipeline, put this into the context of the underlying ATST Data Handling System infrastructure, and finally describe the details of how the algorithms were redesigned to exploit data parallelism in the speckle image reconstruction algorithms. An algorithm re-design is often required to efficiently speed up an application using GPU technology; we have chosen NVIDIA's CUDA language as basis for our implementation. We present our preliminary results of the algorithm performance using our test facilities, and base a conservative estimate on the requirements of a full system that could achieve near real-time performance at ATST on these results.

  2. Studies of the ECR plasma in the visible light range

    International Nuclear Information System (INIS)

    Biri, S.; Racz, R.; Palinkas, J.

    2012-01-01

    High resolution visible light (VL) plasma photographs were taken at the ATOMKI-ECRIS by an 8 mega-pixel digital camera. Plasmas were generated from gases of He, methane, N, O, Ne, Ar, Kr, Xe and from their mixtures. The analysis of the photo series gave many qualitative and numerous valuable physical information on the nature of ECR plasmas. VL photos convey information mainly on the cold electron component of the plasma. Cold electrons are confined in the central part of the plasma. It is a further challenging task to understand the colors of this special type of plasmas. The colors can be determined by the VL electron transitions of the plasma atoms and ions combined with the human eye sensitivity. There is a good visual agreement between the calculated normalized color and the real color of the plasmas. Through the examples of He and Xe we analyze the physical processes which affect the characteristic colors of these plasmas. The paper is followed by the slides of the presentation. (authors)

  3. Aspheric lens based imaging receiver for MIMO visible light communication

    Science.gov (United States)

    Ju, Qiuqi; Liang, Zhongcheng; Liu, Xueming; Yang, Tingting; Wang, Jin

    2014-10-01

    Visible light communication (VLC) has been regarded as a promising solution in short-range intelligent communication system. Nowadays, the research is focused on integrating the multi-input multi-output (MIMO) technique in the VLC system, to achieve a larger transmission capacity and stronger transmission reliability. However, one important issue should be addressed due to the use of MIMO technology: the multipath inter-symbol interference. The multipath intersymbol interference comes from the reflection of the signal in the room and channel crosstalk between different channels. In this paper, we propose a novel optical system used in the MIMO VLC system to reduce multipath interference dramatically. Signals from different LEDs can be separated by using parabolic lens plated with reflecting film. This structure can reduce the reflection effect effectively as well. We present the simulation results to observe the distribution of optical power on the imaging plane for various receiving positions and low correlation between all channels. We can find that the optical power density becomes stronger than non-imaging system and the interference is sharply decreased, thus the SNR and BER are also optimized. Analysis about the optical system is given in this paper.

  4. Visible Contrast Energy Metrics for Detection and Discrimination

    Science.gov (United States)

    Ahumada, Albert; Watson, Andrew

    2013-01-01

    Contrast energy was proposed by Watson, Robson, & Barlow as a useful metric for representing luminance contrast target stimuli because it represents the detectability of the stimulus in photon noise for an ideal observer. Like the eye, the ear is a complex transducer system, but relatively simple sound level meters are used to characterize sounds. These meters provide a range of frequency sensitivity functions and integration times depending on the intended use. We propose here the use of a range of contrast energy measures with different spatial frequency contrast sensitivity weightings, eccentricity sensitivity weightings, and temporal integration times. When detection threshold are plotting using such measures, the results show what the eye sees best when these variables are taken into account in a standard way. The suggested weighting functions revise the Standard Spatial Observer for luminance contrast detection and extend it into the near periphery. Under the assumption that the detection is limited only by internal noise, discrimination performance can be predicted by metrics based on the visible energy of the difference images

  5. Visible absorption spectrum of the CH3CO radical.

    Science.gov (United States)

    Rajakumar, B; Flad, Jonathan E; Gierczak, Tomasz; Ravishankara, A R; Burkholder, James B

    2007-09-20

    The visible absorption spectrum of the acetyl radical, CH(3)CO, was measured between 490 and 660 nm at 298 K using cavity ring-down spectroscopy. Gas-phase CH(3)CO radicals were produced using several methods including: (1) 248 nm pulsed laser photolysis of acetone (CH(3)C(O)CH(3)), methyl ethyl ketone (MEK, CH(3)C(O)CH(2)CH(3)), and biacetyl (CH(3)C(O)C(O)CH(3)), (2) Cl + CH(3)C(O)H --> CH(3)C(O) + HCl with Cl atoms produced via pulsed laser photolysis or in a discharge flow tube, and (3) OH + CH(3)C(O)H --> CH(3)CO + H(2)O with two different pulsed laser photolysis sources of OH radicals. The CH(3)CO absorption spectrum was assigned on the basis of the consistency of the spectra obtained from the different CH(3)CO sources and agreement of the measured rate coefficients for the reaction of the absorbing species with O(2) and O(3) with literature values for the CH(3)CO + O(2) + M and CH(3)CO + O(3) reactions. The CH(3)CO absorption spectrum between 490 and 660 nm has a broad peak centered near 535 nm and shows no discernible structure. The absorption cross section of CH(3)CO at 532 nm was measured to be (1.1 +/- 0.2) x 10(-19) cm(2) molecule(-1) (base e).

  6. Availability and Reliability of FSO Links Estimated from Visibility

    Directory of Open Access Journals (Sweden)

    M. Tatarko

    2012-06-01

    Full Text Available This paper is focused on estimation availability and reliability of FSO systems. Shortcut FSO means Free Space Optics. It is a system which allows optical transmission between two steady points. We can say that it is a last mile communication system. It is an optical communication system, but the propagation media is air. This solution of last mile does not require expensive optical fiber and establishing of connection is very simple. But there are some drawbacks which have a bad influence of quality of services and availability of the link. Number of phenomena in the atmosphere such as scattering, absorption and turbulence cause a large variation of receiving optical power and laser beam attenuation. The influence of absorption and turbulence can be significantly reduced by an appropriate design of FSO link. But the visibility has the main influence on quality of the optical transmission channel. Thus, in typical continental area where rain, snow or fog occurs is important to know their values. This article gives a description of device for measuring weather conditions and information about estimation of availability and reliability of FSO links in Slovakia.

  7. On the Secrecy Capacity of MISO Visible Light Communication Channels

    KAUST Repository

    Arfaoui, Mohamed Amine

    2017-02-07

    We study the secrecy capacity of the multiple- input single-output (MISO) Gaussian wiretap visible light communication (VLC) channel. We study a typical VLC scenario with one transmitter, one legitimate receiver, and one eavesdropper. Specifically, we compute the achievable secrecy rate for various input signaling distributions, including the truncated generalized normal (TGN) and uniform distributions. The transmitter is equipped with multiple light sources, while the legitimate and unauthorized receivers are each equipped with a single photodetector. We analyze the achievable secrecy rates via transmit beamforming and artificial noise. In addition, both zero-forcing beamforming and robust beamforming are considered. In the former case, the location of the eavesdropper is assumed to be known, whereas in the latter case, the location of the eavesdropper is unknown. Our numerical results show that the secrecy rate achieved by the TGN distribution is significantly improved as compared to those achieved by the truncated Gaussian and uniform distributions, for both zero-forcing beamforming and robust beamforming. We also derive an upper bound on the achievable secrecy capacity that we used to assess the closeness of the achievable secrecy rates to the derived bound.

  8. Perovskite Nanocrystals as a Color Converter for Visible Light Communication

    KAUST Repository

    Dursun, Ibrahim

    2016-05-31

    Visible light communication (VLC) is an emerging technology that uses light-emitting diodes (LEDs) or laser diodes for simultaneous illumination and data communication. This technology is envisioned to be a major part of the solution to the current bottlenecks in data and wireless communication. However, the conventional lighting phosphors that are typically integrated with LEDs have limited modulation bandwidth and thus cannot provide the bandwidth required to realize the potential of VLC. In this work, we present a promising light converter for VLC by designing solution-processed CsPbBr3 perovskite nanocrystals (NCs) with a conventional red phosphor. The fabricated CsPbBr3 NCs phosphor-based white light converter exhibits an unprecedented modulation bandwidth of 491 MHz, which is ~ 40 times greater than that of conventional phosphors, and the capability to transmit a high data rate of up to 2 Gbit/s. Moreover, this perovskite enhanced white light source combines ultrafast response characteristics with a high color rendering index of 89 and a low correlated color temperature of 3236 K, thereby enabling dual VLC and solid-state lighting functionalities.

  9. Visible light to electrical energy conversion using photoelectrochemical cells

    Science.gov (United States)

    Wrighton, Mark S. (Inventor); Ellis, Arthur B. (Inventor); Kaiser, Steven W. (Inventor)

    1983-01-01

    Sustained conversion of low energy visible or near i.r. light (>1.25 eV) to electrical energy has been obtained using wet photoelectrochemical cells where there are no net chemical changes in the system. Stabilization of n-type semi-conductor anodes of CdS, CdSe, CdTe, GaP, GaAs and InP to photoanodic dissolution is achieved by employing selected alkaline solutions of Na.sub.2 S, Na.sub.2 S/S, Na.sub.2 Se, Na.sub.2 Se/Se, Na.sub.2 Te and Na.sub.2 Te/Te as the electrolyte. The oxidation of (poly) sulfide, (poly)selenide or (poly)telluride species occurs at the irradiated anode, and reduction of polysulfide, polyselenide or polytelluride species occurs at the dark Pt cathode of the photoelectrochemical cell. Optical to electrical energy conversion efficiencies approaching 15% at selected frequencies have been observed in some cells. The wavelength for the onset of photocurrent corresponds to the band gap of the particular anode material used in the cell.

  10. Blood pulsation measurement using cameras operating in visible light: limitations.

    Science.gov (United States)

    Koprowski, Robert

    2016-10-03

    The paper presents an automatic method for analysis and processing of images from a camera operating in visible light. This analysis applies to images containing the human facial area (body) and enables to measure the blood pulse rate. Special attention was paid to the limitations of this measurement method taking into account the possibility of using consumer cameras in real conditions (different types of lighting, different camera resolution, camera movement). The proposed new method of image analysis and processing was associated with three stages: (1) image pre-processing-allowing for the image filtration and stabilization (object location tracking); (2) main image processing-allowing for segmentation of human skin areas, acquisition of brightness changes; (3) signal analysis-filtration, FFT (Fast Fourier Transformation) analysis, pulse calculation. The presented algorithm and method for measuring the pulse rate has the following advantages: (1) it allows for non-contact and non-invasive measurement; (2) it can be carried out using almost any camera, including webcams; (3) it enables to track the object on the stage, which allows for the measurement of the heart rate when the patient is moving; (4) for a minimum of 40,000 pixels, it provides a measurement error of less than ±2 beats per minute for p lighting; (5) analysis of a single image takes about 40 ms in Matlab Version 7.11.0.584 (R2010b) with Image Processing Toolbox Version 7.1 (R2010b).

  11. Spectroscopic Doppler analysis for visible-light optical coherence tomography

    Science.gov (United States)

    Shu, Xiao; Liu, Wenzhong; Duan, Lian; Zhang, Hao F.

    2017-12-01

    Retinal oxygen metabolic rate can be effectively measured by visible-light optical coherence tomography (vis-OCT), which simultaneously quantifies oxygen saturation and blood flow rate in retinal vessels through spectroscopic analysis and Doppler measurement, respectively. Doppler OCT relates phase variation between sequential A-lines to the axial flow velocity of the scattering medium. The detectable phase shift is between -π and π due to its periodicity, which limits the maximum measurable unambiguous velocity without phase unwrapping. Using shorter wavelengths, vis-OCT is more vulnerable to phase ambiguity since flow induced phase variation is linearly related to the center wavenumber of the probing light. We eliminated the need for phase unwrapping using spectroscopic Doppler analysis. We split the whole vis-OCT spectrum into a series of narrow subbands and reconstructed vis-OCT images to extract corresponding Doppler phase shifts in all the subbands. Then, we quantified flow velocity by analyzing subband-dependent phase shift using linear regression. In the phantom experiment, we showed that spectroscopic Doppler analysis extended the measurable absolute phase shift range without conducting phase unwrapping. We also tested this method to quantify retinal blood flow in rodents in vivo.

  12. Extrasolar Planetary Imaging Coronagraph (EPIC): visible nulling cornagraph testbed results

    Science.gov (United States)

    Lyon, Richard G.; Clampin, Mark; Melnick, Gary; Tolls, Volker; Woodruff, Robert; Vasudevan, Gopal

    2008-07-01

    The Extrasolar Planetary Imaging Coronagraph (EPIC) is a NASA Astrophysics Strategic Mission Concept under study for the upcoming Exoplanet Probe. EPIC's mission would be to image and characterize extrasolar giant planets, and potential super-Earths, in orbits with semi-major axes between 2 and 10 AU. EPIC will provide insights into the physical nature of a variety of planets in other solar systems complimenting radial velocity (RV) and astrometric planet searches. It will detect and characterize the atmospheres of planets identified by radial velocity surveys and potentially some transits, determine orbital inclinations and masses, characterize the atmospheres of gas giants around A and F stars, observed the inner spatial structure and colors of inner Spitzer selected debris disks. EPIC would be launched into a heliocentric Earth trailing drift-away orbit, with a 3-year mission lifetime (5 year goal) and will revisit planets at least three times. The starlight suppression approach consists of a visible nulling coronagraph (VNC) that enables high order starlight suppression in broadband light. To demonstrate the VNC approach and advance it's technology readiness the NASA/Goddard Space Flight Center and Lockheed-Martin have developed a laboratory VNC and have demonstrated white light nulling. We will discuss our ongoing VNC work and show the latest results from the VNC testbed.

  13. Extrasolar Planetary Imaging Coronagraph: Visible Nulling Coronagraph Testbed Results

    Science.gov (United States)

    Lyon, Richard G.

    2008-01-01

    The Extrasolar Planetary Imaging Coronagraph (EPIC) is a proposed NASA Discovery mission to image and characterize extrasolar giant planets in orbits with semi-major axes between 2 and 10 AU. EPIC will provide insights into the physical nature of a variety of planets in other solar systems complimenting radial velocity (RV) and astrometric planet searches. It will detect and characterize the atmospheres of planets identified by radial velocity surveys, determine orbital inclinations and masses, characterize the atmospheres around A and F stars, observed the inner spatial structure and colors of inner Spitzer selected debris disks. EPIC would be launched to heliocentric Earth trailing drift-away orbit, with a 3-year mission lifetime ( 5 year goal) and will revisit planets at least three times at intervals of 9 months. The starlight suppression approach consists of a visible nulling coronagraph (VNC) that enables high order starlight suppression in broadband light. To demonstrate the VNC approach and advance it's technology readiness the NASA Goddard Space Flight Center and Lockheed-Martin have developed a laboratory VNC and have demonstrated white light nulling. We will discuss our ongoing VNC work and show the latest results from the VNC testbed,

  14. Visible Nulling Coronagraphy for Exo-Planetary Detection and Characterization

    Science.gov (United States)

    Lyon, Richard G.; Clampin, Mark; Woodruff, Robert; Vasudevan, Gopal; Shao, Mike; Levine, Martin; Melnick, Gary; Tolls, Volker; Petrone, Peter; Dogoda, Peter; Duval, Julia; Ge, Jian

    Visible Nulling Coronagraphy (VNC) is the proposed method of detecting and characterizing exo-solar Jovian planets (null depth 10-9) for the proposed NASA's Extrasolar Planetary Imaging Coronagraph (EPIC) Clampin & Lyon 2004 and is an approach under evaluation for NASA's Terrestrial Planet Finder (TPF) mission. The VNC approach uses a single unobscured filled-aperture telescope and splits, via a 50:50 beamsplitter, its re-imaged pupil into two paths within a Mach-Zender interferometer. An achromatic PI phase shift is imposed onto one beam path and the two paths are laterally sheared with respect to each other. The two beams are recombined at a second 50:50 beamsplitter. The net effect is that the on axis (stellar) light is transmitted out of the bright interferometer arm while the off-axis (planetary) light is transmitted out of the nulled interferometer arm. The bright output is used for fine pointing control and coarse wavefront control. The nulled output is relayed to the science camera for science imagery and fine wavefront control. The actual transmission pattern, projected on the sky, follows a θ^2 pattern for a single shear, θ^4 for a double shear, with the spacing of the successive maxima proportional to the inverse of the relative lateral shear. Combinations of shears and spacecraft rolls build up the spatial frequency content of the sky transmission pattern in the same manner as imaging interferometer builds up the spatial frequency content of the image.

  15. Mobile health-monitoring system through visible light communication.

    Science.gov (United States)

    Tan, Yee-Yong; Chung, Wan-Young

    2014-01-01

    Promising development in the light emitting diode (LED) technology has spurred the interest to adapt LED for both illumination and data transmission. This has fostered the growth of interest in visible light communication (VLC), with on-going research to utilize VLC in various applications. This paper presents a mobile-health monitoring system, where healthcare information such as biomedical signals and patient information are transmitted via the LED lighting. A small and portable receiver module is designed and developed to be attached to the mobile device, providing a seamless monitoring environment. Three different healthcare information including ECG, PPG signals and HL7 text information is transmitted simultaneously, using a single channel VLC. This allows for a more precise and accurate monitoring and diagnosis. The data packet size is carefully designed, to transmit information in a minimal packet error rate. A comprehensive monitoring application is designed and developed through the use of a tablet computer in our study. Monitoring and evaluation such as heart rate and arterial blood pressure measurement can be performed concurrently. Real-time monitoring is demonstrated through experiment, where non-hazardous transmission method can be implemented alongside a portable device for better and safer healthcare service.

  16. Continuous zoom antenna for mobile visible light communication.

    Science.gov (United States)

    Zhang, Xuebin; Tang, Yi; Cui, Lu; Bai, Tingzhu

    2015-11-10

    In this paper, we design a continuous zoom antenna for mobile visible light communication (VLC). In the design, a right-angle reflecting prism was adopted to fold the space optical path, thus decreasing the antenna thickness. The surface of each lens in the antenna is spherical, and the system cost is relatively low. Simulation results indicated that the designed system achieved the following performance: zoom ratio of 2.44, field of view (FOV) range of 18°-48°, system gain of 16.8, and system size of 18 mm×6  mm. Finally, we established an indoor VLC system model in a room the size of 5  m ×5  m ×3  m and compared the detection results of the zoom antenna and fixed-focus antenna obtained in a multisource communication environment, a mobile VLC environment, and a multiple-input multiple-output communication environment. The simulation results indicated that the continuous zoom antenna could realize large FOV and high gain. Moreover, the system showed improved stability, mobility, and environmental applicability.

  17. Phase transition in the parametric natural visibility graph.

    Science.gov (United States)

    Snarskii, A A; Bezsudnov, I V

    2016-10-01

    We investigate time series by mapping them to the complex networks using a parametric natural visibility graph (PNVG) algorithm that generates graphs depending on arbitrary continuous parameter-the angle of view. We study the behavior of the relative number of clusters in PNVG near the critical value of the angle of view. Artificial and experimental time series of different nature are used for numerical PNVG investigations to find critical exponents above and below the critical point as well as the exponent in the finite size scaling regime. Altogether, they allow us to find the critical exponent of the correlation length for PNVG. The set of calculated critical exponents satisfies the basic Widom relation. The PNVG is found to demonstrate scaling behavior. Our results reveal the similarity between the behavior of the relative number of clusters in PNVG and the order parameter in the second-order phase transitions theory. We show that the PNVG is another example of a system (in addition to magnetic, percolation, superconductivity, etc.) with observed second-order phase transition.

  18. Visible region MCD and MLD spectra of nitrosylferrohemoglobin and oxyhemoglobin.

    Science.gov (United States)

    Pearce, Linda L; Bominaar, Emile L; Peterson, Jim

    2002-09-20

    Magnetic circular dichroism (MCD) and magnetic linear dichroism (MLD) spectroscopies at various applied magnetic fields (0-6T) and temperatures (2.0-31K) have been used to investigate the electronic properties of the visible (Q(0-0), or alpha band) region of oxy- and nitrosylferrohemoglobin (HbNO). OxyHb, a d(6) (S=0) diamagnet, exhibits the expected pseudo-first derivative MCD and pseudo-second derivative MLD temperature-independent features centered at 574nm. HbNO, a d(7) (S=1/2) paramagnet, also exhibits a temperature-independent pseudo-first derivative MCD spectrum, but centered at 571nm. So far as we are aware, this behavior is unprecedented in the MCD spectra of paramagetic iron-porphyrins, which are expected to be dominated by temperature-dependent C(0) terms. The HbNO MCD spectrum does, however, demonstrate limited field-dependent saturation magnetization behavior and the MLD spectrum is currently below the detection limit. In addition, an MCD signal from reoxygenated venous blood is reported and compared with MCD signals from oxy- and HbNO derivatives. Finally, a combination of MCD and MLD spectroscopies has been used to estimate the orbital angular momentum (M(L)) value of the alpha band excited state of oxyHb as 4.2 (+/-0.7).

  19. The route to visible light photolithography using hyperlens

    Science.gov (United States)

    Sun, Jingbo; Litchinitser, Natalia M.

    2018-04-01

    Hyperlens, a curved hyperbolic metamaterials-based device, first emerged as a promising way of overcoming the diffraction limit for subwavelength imaging applications. In addition, it was recently realized that it can be used for sub-wavelength de-magnification. The magnification/de-magnification rate of the hyperlens is directly related to the thickness of the hyperbolic metamaterial. In this paper, we perform a systematic study on the de-magnification properties in different types of the hyperlens. We optimize the de-magnifying properties of a hyperlens to facilitate its potential applications for sub-wavelength photolithography. In order to achieve the required de-magnification properties, we developed a multi-step multi-layer deposition method to fabricate high-quality, thick hyperbolic metamaterials, advancing the state-of-the-art magnification and/or de-magnification properties of the hyperlens. The application of such a high de-magnification rate hyperlens in the photolithography technique may open up a new approach to the nanolithography using visible light, addressing growing demands for inexpensive, all-optical nanoscale pattern recording.

  20. Switchable polarization rotation of visible light using a plasmonic metasurface

    Directory of Open Access Journals (Sweden)

    Stuart K. Earl

    2017-01-01

    Full Text Available A metasurface comprising an array of silver nanorods supported by a thin film of the phase change material vanadium dioxide is used to rotate the primary polarization axis of visible light at a pre-determined wavelength. The dimensions of the rods were selected such that, across the two phases of vanadium dioxide, the two lateral localized plasmon resonances (in the plane of the metasurface occur at the same wavelength. Illumination with linearly polarized light at 45° to the principal axes of the rod metasurface enables excitation of both of these resonances. Modulating the phase of the underlying substrate, we show that it is possible to reversibly switch which axis of the metasurface is resonant at the operating wavelength. Analysis of the resulting Stokes parameters indicates that the orientation of the principal linear polarization axis of the reflected signal is rotated by 90° around these wavelengths. Dynamic metasurfaces such as these have the potential to form the basis of an ultra-compact, low-energy multiplexer or router for an optical signal.

  1. Visibility of changes in light intensity caused by voltage leaps

    International Nuclear Information System (INIS)

    Seljeseth, Helge; Mogstad, Olve

    2006-05-01

    Sintef Energy Research was engaged by NVE to evaluate the official requirements on voltage leaps in regulations concerning quality of delivery, and simultaneously conduct tests with a panel of test persons in order to get more detailed evaluations and recommendations to the existing requirements on voltage leaps. Tests and laboratory experiments have been performed on a total of 96 test persons, and the results reveal that voltage leaps even smaller than the 3 percent limit set by Norwegian regulations are visible to most people. The majority of the test persons consider the light conditions as unacceptably bad when light conditions are near the limit of voltage leap. Moreover, 25 percent of the test persons considered the light quality unacceptable when the voltage leap was well under half of the official limit.The results of the experiments indicates a need for narrowing the restrictions on voltage leaps in the Norwegian power network in order to limit the size and frequency of this kind of disturbance in the voltage. Recommendations for regulations are elaborated in chapter 3 (ml)

  2. Forward and correctional OFDM-based visible light positioning

    Science.gov (United States)

    Li, Wei; Huang, Zhitong; Zhao, Runmei; He, Peixuan; Ji, Yuefeng

    2017-09-01

    Visible light positioning (VLP) has attracted much attention in both academic and industrial areas due to the extensive deployment of light-emitting diodes (LEDs) as next-generation green lighting. Generally, the coverage of a single LED lamp is limited, so LED arrays are always utilized to achieve uniform illumination within the large-scale indoor environment. However, in such dense LED deployment scenario, the superposition of the light signals becomes an important challenge for accurate VLP. To solve this problem, we propose a forward and correctional orthogonal frequency division multiplexing (OFDM)-based VLP (FCO-VLP) scheme with low complexity in generating and processing of signals. In the first forward procedure of FCO-VLP, an initial position is obtained by the trilateration method based on OFDM-subcarriers. The positioning accuracy will be further improved in the second correctional procedure based on the database of reference points. As demonstrated in our experiments, our approach yields an improved average positioning error of 4.65 cm and an enhanced positioning accuracy by 24.2% compared with trilateration method.

  3. Visible light communication technology for fine-grained indoor localization

    Science.gov (United States)

    Vieira, M.; Vieira, M. A.; Louro, P.; Fantoni, A.; Vieira, P.

    2018-02-01

    This paper focuses on designing and analysing a visible light based communication and positioning system. The indoor positioning system uses trichromatic white Light Emitting Diodes (LEDs), both for illumination purposes and as transmitters, and an optical processor, based on a-SiC:H technology, as mobile receiver. On-Off Keying (OOK) modulation scheme is used, proving a good trade-off between system performance and implementation complexity. In the following, the relationship between the transmitted data and the received output levels is decoded. LED bulbs work as transmitters, sending information together with different identifiers, IDs, related to their physical locations. Square and diamond topologies for the unit cell are analyzed, and a 2D localization design, demonstrated by a prototype implementation, is presented. Fine-grained indoor localization is tested. The received signal is used in coded multiplexing techniques for supporting communications and navigation concomitantly on the same channel. The location and motion information is found by mapping the position and estimating the location areas.

  4. Subcarrier intensity modulation for MIMO visible light communications

    Science.gov (United States)

    Celik, Yasin; Akan, Aydin

    2018-04-01

    In this paper, subcarrier intensity modulation (SIM) is investigated for multiple-input multiple-output (MIMO) visible light communication (VLC) systems. A new modulation scheme called DC-aid SIM (DCA-SIM) is proposed for the spatial modulation (SM) transmission plan. Then, DCA-SIM is extended for multiple subcarrier case which is called DC-aid Multiple Subcarrier Modulation (DCA-MSM). Bit error rate (BER) performances of the considered system are analyzed for different MIMO schemes. The power efficiencies of DCA-SIM and DCA-MSM are shown in correlated MIMO VLC channels. The upper bound BER performances of the proposed models are obtained analytically for PSK and QAM modulation types in order to validate the simulation results. Additionally, the effect of power imbalance method on the performance of SIM is studied and remarkable power gains are obtained compared to the non-power imbalanced cases. In this work, Pulse amplitude modulation (PAM) and MSM-Index are used as benchmarks for single carrier and multiple carrier cases, respectively. And the results show that the proposed schemes outperform PAM and MSM-Index for considered single carrier and multiple carrier communication scenarios.

  5. Reactor safety research - visible demonstrations and credible computations

    International Nuclear Information System (INIS)

    Loewenstein, W.B.; Divakaruni, S.M.

    1985-01-01

    EPRI has been conducting nuclear safety research for a number of years with the primary goal of assuring the safety and reliability of the nuclear plants. The visibility is emphasized by sponsoring or participating in large scale test demonstrations to credibly support the complex computations that are the basis for quantification of safety margins. Recognizing the success of the airline industry in receiving favorable public perception, the authors compare the design and operation practices of the airline industry with those of the nuclear industry practices to identify the elements contributing to public concerns and unfavorable perceptions. In this paper, authors emphasize the importance of proper communications of research results to the public in a manner that non-specialists understand. Further, EPRI supported research and results in the areas of source term, seismic and structural engineering research, analysis using probabilistic risk assessment (PRA), quantification of safety margins, digital technology development and implementation, and plant transient and performance evaluations are discussed in the paper. (orig./HP)

  6. Broad electrical tuning of plasmonic nanoantennas at visible frequencies

    Energy Technology Data Exchange (ETDEWEB)

    Hoang, Thang B. [Department of Physics, Duke University, Durham, North Carolina 27708 (United States); Center for Metamaterials and Integrated Plasmonics, Duke University, Durham, North Carolina 27708 (United States); Mikkelsen, Maiken H., E-mail: m.mikkelsen@duke.edu [Department of Physics, Duke University, Durham, North Carolina 27708 (United States); Center for Metamaterials and Integrated Plasmonics, Duke University, Durham, North Carolina 27708 (United States); Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708 (United States)

    2016-05-02

    We report an experimental demonstration of electrical tuning of plasmon resonances of optical nanopatch antennas over a wide wavelength range. The antennas consist of silver nanocubes separated from a gold film by a thin 8 nm polyelectrolyte spacer layer. By using ionic liquid and indium tin oxide coated glass as a top electrode, we demonstrate dynamic and reversible tuning of the plasmon resonance over 100 nm in the visible wavelength range using low applied voltages between −3.0 V and 2.8 V. The electrical potential is applied across the nanoscale gap causing changes in the gap thickness and dielectric environment which, in turn, modifies the plasmon resonance. The observed tuning range is greater than the full-width-at-half-maximum of the plasmon resonance, resulting in a tuning figure of merit of 1.05 and a tuning contrast greater than 50%. Our results provide an avenue to create active and reconfigurable integrated nanophotonic components for applications in optoelectronics and sensing.

  7. Beamforming applied to surface EEG improves ripple visibility.

    Science.gov (United States)

    van Klink, Nicole; Mol, Arjen; Ferrier, Cyrille; Hillebrand, Arjan; Huiskamp, Geertjan; Zijlmans, Maeike

    2018-01-01

    Surface EEG can show epileptiform ripples in people with focal epilepsy, but identification is impeded by the low signal-to-noise ratio of the electrode recordings. We used beamformer-based virtual electrodes to improve ripple identification. We analyzed ten minutes of interictal EEG of nine patients with refractory focal epilepsy. EEGs with more than 60 channels and 20 spikes were included. We computed ∼79 virtual electrodes using a scalar beamformer and marked ripples (80-250 Hz) co-occurring with spikes in physical and virtual electrodes. Ripple numbers in physical and virtual electrodes were compared, and sensitivity and specificity of ripples for the region of interest (ROI; based on clinical information) were determined. Five patients had ripples in the physical electrodes and eight in the virtual electrodes, with more ripples in virtual than in physical electrodes (101 vs. 57, p = .007). Ripples in virtual electrodes predicted the ROI better than physical electrodes (AUC 0.65 vs. 0.56, p = .03). Beamforming increased ripple visibility in surface EEG. Virtual ripples predicted the ROI better than physical ripples, although sensitivity was still poor. Beamforming can facilitate ripple identification in EEG. Ripple localization needs to be improved to enable its use for presurgical evaluation in people with epilepsy. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

  8. Unequal error control scheme for dimmable visible light communication systems

    Science.gov (United States)

    Deng, Keyan; Yuan, Lei; Wan, Yi; Li, Huaan

    2017-01-01

    Visible light communication (VLC), which has the advantages of a very large bandwidth, high security, and freedom from license-related restrictions and electromagnetic-interference, has attracted much interest. Because a VLC system simultaneously performs illumination and communication functions, dimming control, efficiency, and reliable transmission are significant and challenging issues of such systems. In this paper, we propose a novel unequal error control (UEC) scheme in which expanding window fountain (EWF) codes in an on-off keying (OOK)-based VLC system are used to support different dimming target values. To evaluate the performance of the scheme for various dimming target values, we apply it to H.264 scalable video coding bitstreams in a VLC system. The results of the simulations that are performed using additive white Gaussian noises (AWGNs) with different signal-to-noise ratios (SNRs) are used to compare the performance of the proposed scheme for various dimming target values. It is found that the proposed UEC scheme enables earlier base layer recovery compared to the use of the equal error control (EEC) scheme for different dimming target values and therefore afford robust transmission for scalable video multicast over optical wireless channels. This is because of the unequal error protection (UEP) and unequal recovery time (URT) of the EWF code in the proposed scheme.

  9. Optical antenna for a visible light communications receiver

    Science.gov (United States)

    Valencia-Estrada, Juan Camilo; García-Márquez, Jorge; Topsu, Suat; Chassagne, Luc

    2018-01-01

    Visible Light Communications (VLC) receivers adapted to be used in high transmission rates will eventually use either, high aperture lenses or non-linear optical elements capable of converting light arriving to the receiver into an electric signal. The high aperture lens case, reveals a challenge from an optical designers point-of-view. As a matter of fact, the lens must collect a wide aperture intensity flux using a limited aperture as its use is intended to portable devices. This last also limits both, lens thickness and its focal length. Here, we show a first design to be adapted to a VLC receiver that take these constraints into account. This paper describes a method to design catadioptric and monolithic lenses to be used as an optical collector of light entering from a near point light source as a spherical fan L with a wide acceptance angle α° and high efficiency. These lenses can be mass produced and therefore one can find many practical applications in VLC equipped devices. We show a first design for a near light source without magnification, and second one with a detector's magnification in a meridional section. We utilize rigorous geometric optics, vector analysis and ordinary differential equations.

  10. Optimization of a miniature short-wavelength infrared objective optics of a short-wavelength infrared to visible upconversion layer attached to a mobile-devices visible camera

    Science.gov (United States)

    Kadosh, Itai; Sarusi, Gabby

    2017-10-01

    The use of dual cameras in parallax in order to detect and create 3-D images in mobile devices has been increasing over the last few years. We propose a concept where the second camera will be operating in the short-wavelength infrared (SWIR-1300 to 1800 nm) and thus have night vision capability while preserving most of the other advantages of dual cameras in terms of depth and 3-D capabilities. In order to maintain commonality of the two cameras, we propose to attach to one of the cameras a SWIR to visible upconversion layer that will convert the SWIR image into a visible image. For this purpose, the fore optics (the objective lenses) should be redesigned for the SWIR spectral range and the additional upconversion layer, whose thickness is mobile device visible range camera sensor (the CMOS sensor). This paper presents such a SWIR objective optical design and optimization that is formed and fit mechanically to the visible objective design but with different lenses in order to maintain the commonality and as a proof-of-concept. Such a SWIR objective design is very challenging since it requires mimicking the original visible mobile camera lenses' sizes and the mechanical housing, so we can adhere to the visible optical and mechanical design. We present in depth a feasibility study and the overall optical system performance of such a SWIR mobile-device camera fore optics design.

  11. Visible light assisted photodegradation of halocarbons on the dye modified TiO{sub 2} surface using visible light

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Debabrata; Dasgupta, Shimanti [Chemistry Section, Central Mechanical Engineering Research Institute, Durgapur 713209 (India); N Rao, Nageswar [Wastewater Technology Division, National Environmental Engineering Research Institute, Nagpur 400020 (India)

    2006-05-05

    Visible light assisted photodegradation of various halocarbons, viz. chloro-phenols, trichloroethylene, 1,2-dichloroethane and 1,4-dichlorobenzene, has been achieved on the surface of dye-modified TiO{sub 2} semiconductor. Thionine, eosinY, rhodamineB, methyleneblue, nileblueA and safranineO were used for the modification of TiO{sub 2} semiconductor photocatalyst. After 5h of irradiation with a 150W Xenon lamp, over 55-72% degradation of pollutants has been achieved. A working mechanism involving excitation of surface adsorbed dye, followed by charge injection into the TiO{sub 2} conduction band and formation of reactive {sup *}O{sub 2}{sup -}/{sup *}HO{sub 2} radicals, is proposed for the degradation of the enlisted organics to carbon dioxide. Efficacy of the photocatalytic system towards halocarbon degradation has been discussed in regard to excited state redox properties of the dyes selected for this study. Formation of {sup *}O{sub 2}{sup -} radical has been substantiated by using a chemiluminescent probe luminol. (author)

  12. Now You See It: Using Documentation to Make Learning Visible in LCs

    Science.gov (United States)

    Mino, Jack J.

    2014-01-01

    The practice of documentation is discussed as a means of making learning visible in the LC classroom. A documentation heuristic consisting of a four-stage cycle was used to capture, analyze and report what Bass and Eynon (2009) refer to as the "visible evidence of invisible learning" (p. 5). A variety of documentation samples are…

  13. Proximity and Visibility of Fruits and Vegetables Influence Intake in a Kitchen Setting among College Students

    Science.gov (United States)

    Privitera, Gregory J.; Creary, Heather E.

    2013-01-01

    The hypothesis that participants will eat more fruits (apple slices) and vegetables (carrot cuts) if they are made more proximate and visible was tested using a 2 × 2 between-participants design. Proximity was manipulated by placing fruits and vegetables in a bowl at a table where participants sat (near) or 2 m from the table (far). Visibility was…

  14. Outstanding visible photocatalytic activity of a new mixed bismuth titanatate material

    Energy Technology Data Exchange (ETDEWEB)

    Zambrano, P. [Instituto de Ciencia de Materiales de Sevilla, CSIC-Universidad de Sevilla, Americo Vespucio 49, 410092, Sevilla (Spain); Departamento Cristalografía, Mineralogía y Química Agrícola, Universidad de Sevilla, C/Profesor García González s/n, 41012 Sevilla (Spain); Sayagués, M.J.; Navío, J.A. [Instituto de Ciencia de Materiales de Sevilla, CSIC-Universidad de Sevilla, Americo Vespucio 49, 410092, Sevilla (Spain); Hidalgo, M.C., E-mail: carmen.hidalgo@csic.es [Instituto de Ciencia de Materiales de Sevilla, CSIC-Universidad de Sevilla, Americo Vespucio 49, 410092, Sevilla (Spain)

    2017-02-01

    Highlights: • Photocatalyst based on bismuth titanates with high visible activity. • Its visible activity as high as UV activity of TiO{sub 2} P25 for phenol degradation. • Photocatalyst is majority of phase Bi{sub 20}TiO{sub 32} with Bi{sub 4}Ti{sub 3}O{sub 12} and amorphous TiO{sub 2}. • High visible activity due to low BG, interconnected phases and high surface area. - Abstract: In this work, a new photocatalyst based on bismuth titanates with outstanding visible photocatalytic activity was prepared by a facile hydrothermal method. The synthesised material showed visible activity as high as UV activity of commercial TiO{sub 2} P25 under the same experimental conditions for phenol degradation. A wide characterisation of the photocatalyst was performed. The material was composed of three phases; majority of Bi{sub 20}TiO{sub 32} closely interconnected to Bi{sub 4}Ti{sub 3}O{sub 12} and amorphous TiO{sub 2}. The high visible activity showed by this material could be ascribed to a combination of several features; i.e. low band gap energy value (2.1 eV), a structure allowing a good separation path for visible photogenerated electron-holes pairs and a relatively high surface area. This photocatalyst appeared as a promising material for solar and visible applications of photocatalysis.

  15. Visibility Analysis in a Point Cloud Based on the Medial Axis Transform

    NARCIS (Netherlands)

    Peters, R.; Ledoux, H.; Biljecki, F.

    2015-01-01

    Visibility analysis is an important application of 3D GIS data. Current approaches require 3D city models that are often derived from detailed aerial point clouds. We present an approach to visibility analysis that does not require a city model but works directly on the point cloud. Our approach is

  16. Joint illumination and visible-light communication systems : data rates and extra power consumption

    NARCIS (Netherlands)

    Tsiatmas, Anagnostis; Willems, Frans; Linnartz, Jean-Paul; Baggen, C.P.M.J.; Bergmans, Jan

    2015-01-01

    Visible Light Communications (VLC) have been promoted as an energy-efficient Gb/s-technology for indoor settings, since VLC can be merged with the illumination functionality. As a result, Joint Illumination and visible-light Communication (JIC) systems are perceived as a green technology and the

  17. Evaluation of Driver Visibility from Mobile LIDAR Data and Weather Conditions

    Science.gov (United States)

    González-Jorge, H.; Díaz-Vilariño, L.; Lorenzo, H.; Arias, P.

    2016-06-01

    Visibility of drivers is crucial to ensure road safety. Visibility is influenced by two main factors, the geometry of the road and the weather present therein. The present work depicts an approach for automatic visibility evaluation using mobile LiDAR data and climate information provided from weather stations located in the neighbourhood of the road. The methodology is based on a ray-tracing algorithm to detect occlusions from point clouds with the purpose of identifying the visibility area from each driver position. The resulting data are normalized with the climate information to provide a polyline with an accurate area of visibility. Visibility ranges from 25 m (heavy fog) to more than 10,000 m (clean atmosphere). Values over 250 m are not taken into account for road safety purposes, since this value corresponds to the maximum braking distance of a vehicle. Two case studies are evaluated an urban road in the city of Vigo (Spain) and an inter-urban road between the city of Ourense and the village of Castro Caldelas (Spain). In both cases, data from the Galician Weather Agency (Meteogalicia) are used. The algorithm shows promising results allowing the detection of particularly dangerous areas from the viewpoint of driver visibility. The mountain road between Ourense and Castro Caldelas, with great presence of slopes and sharp curves, shows special interest for this type of application. In this case, poor visibility can especially contribute to the run over of pedestrians or cyclists traveling on the road shoulders.

  18. A fundamental study on the influence of the illuminant conditions for the visibility

    International Nuclear Information System (INIS)

    Fukui, Hirokazu; Ohuchi, Hiroko; Akagi, Sigefumi; Natori, Kazuyuki

    2002-01-01

    This research was done to explain the way of color combinations for the signs that are excellent in the visibility. The research was composed by three experiments, color naming experiment and the visibility experiment 1 and 2. In the color naming experiment, what kind of color combinations investigated whether a target color could be judged precisely under the various lighting illuminant. The visibility experiment 1 examined the various color combinations that became effective for the visibility under the illuminant. And, the visibility experiment 2 examined the color combinations that were effective for the visibility from the lighting illuminant and the illuminance. Yellow in white background, white in yellow background, purple in red background, purple in green background, as for these 4 color combinations, it became clear that it is the color combination which needed attention under all the lighting illuminants from the color naming experiment and the visibility experiment 1. In the visibility experiment 2, relative visual acuity became more than 0.7 in all the lighting illuminants if there was a ΔL * from the background and the target beyond 30 in the case of the illuminance of 5001x. And, when illuminance was 501x, it became clear that it become less than 0.7 by all the color schemes as for the relative visual acuity in all the lighting illuminants. (author)

  19. Enhanced visible-light activity of titania via confinement inside carbon nanotubes

    KAUST Repository

    Chen, Wei; Fan, Zhongli; Zhang, Bei; Ma, Guijun; Takanabe, Kazuhiro; Zhang, Xixiang; Lai, Zhiping

    2011-01-01

    O 2 in comparison with nanoparticles dispersed on the outer surface of CNTs, extending the photoresponse of TiO 2 from the UV to the visible-light region. The CNT-confined TiO 2 exhibited improved visible-light activity in the degradation of methylene

  20. Simulating the z= 3.35 HI 21-cm Visibility Signal for the Ooty Wide ...

    Indian Academy of Sciences (India)

    This means that each accepted article is being published immediately online with DOI and article citation ID with starting page number 1. Articles are also visible in Web of Science immediately. All these have helped shorten the publication time and have improved the visibility of the articles. © 2017 Indian Academy of ...

  1. Estimation of visibility of phase contrast with extraction voltages for field emission gun electron microscopes

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Xing, E-mail: xmeng101@gmail.com

    2017-02-15

    Estimation was made for visibility of phase contrast with varying extraction voltages. The resulting decay rates of visibility show that images with low image contrast from cryo EM will be seriously impacted with high extraction voltages. - Highlights: • Cryo EM • Phase contrast • Extraction votage.

  2. Remote Spectroscopy in the Visible Using Fibers on the Optical Internet Network

    Science.gov (United States)

    Ribeiro, Rafael A. S.; de Oliveira, Anderson R.; Zilio, Sergio C.

    2010-01-01

    The work presented here demonstrates the feasibility of using the single-mode fibers of an optical Internet network to deliver visible light between separate laboratories as a way to perform remote spectroscopy in the visible for teaching purposes. The coupling of a broadband light source into the single-mode fiber (SMF) and the characterization…

  3. Prompting Students to Contemplate Effective Communication with a Visible Speech Chart from the 1870s

    Science.gov (United States)

    Potter, Lee Ann

    2014-01-01

    In this article, director of Educational Outreach at the Library of Congress Lee Ann Potter describes a classroom activity that focuses on an 1876 single-page circular published in Salem, Massachusetts about Alexander Melville Bell's Visible Speech. A. M. Bell's son, Alexander Graham Bell described "Visible Speech" as "a…

  4. EVALUATION OF DRIVER VISIBILITY FROM MOBILE LIDAR DATA AND WEATHER CONDITIONS

    Directory of Open Access Journals (Sweden)

    H. González-Jorge

    2016-06-01

    Full Text Available Visibility of drivers is crucial to ensure road safety. Visibility is influenced by two main factors, the geometry of the road and the weather present therein. The present work depicts an approach for automatic visibility evaluation using mobile LiDAR data and climate information provided from weather stations located in the neighbourhood of the road. The methodology is based on a ray-tracing algorithm to detect occlusions from point clouds with the purpose of identifying the visibility area from each driver position. The resulting data are normalized with the climate information to provide a polyline with an accurate area of visibility. Visibility ranges from 25 m (heavy fog to more than 10,000 m (clean atmosphere. Values over 250 m are not taken into account for road safety purposes, since this value corresponds to the maximum braking distance of a vehicle. Two case studies are evaluated an urban road in the city of Vigo (Spain and an inter-urban road between the city of Ourense and the village of Castro Caldelas (Spain. In both cases, data from the Galician Weather Agency (Meteogalicia are used. The algorithm shows promising results allowing the detection of particularly dangerous areas from the viewpoint of driver visibility. The mountain road between Ourense and Castro Caldelas, with great presence of slopes and sharp curves, shows special interest for this type of application. In this case, poor visibility can especially contribute to the run over of pedestrians or cyclists traveling on the road shoulders.

  5. The effect of direction of illumination upon the visibility of a smoke column

    Science.gov (United States)

    Charles C. Buck; Wallace L. Fons

    1935-01-01

    Preliminary investigations in the detection of forest fires at the California Forest and Range Experiment Station were based on the assumption that the visibility of smoke columns in the field would vary as the visibility of the landscape with varying conditions of atmospheric suspensoid concentration and with the position of the sun. This led to the determination of...

  6. The visibility of mandibular canal on orthoradial and oblique CBCT slices at molar implant sites

    International Nuclear Information System (INIS)

    Alkhader, Mustafa; Jarab, Fadi; Shaweesh, Ashraf; Hudieb, Malik

    2016-01-01

    The aim of the present study was to compare visibility of the mandibular canal on cone beam computed tomography (CBCT)-based orthoradial and oblique slices at molar implant sites. CBCT images for 132 mandibular molar implant sites were selected for the study. After generating orthoradial and oblique slices, two observers evaluated the visibility of the mandibular canal using three-point scoring scale (1-3, good to excellent). Wilcoxon signed-rank test compared the visibility scores of the two slices. Both orthoradial and oblique slices obtained from CBCT had only very good to excellent mandibular canal visibility scores. At 114 mandibular molar implant sites, the visibility score was equal on both orthoradial and oblique slices. Although the visibility score was higher on orthoradial slices for 12 implant sites, the visibility score was higher for six implant sites on oblique slices and the difference was not significant. Therefore, the visibility of the mandibular canal was excellent and comparable on most of orthoradial and oblique slices obtained from CBCT images

  7. A fundamental study on the influence of the illuminant conditions for the visibility

    Energy Technology Data Exchange (ETDEWEB)

    Fukui, Hirokazu [Institute of Nuclear Safety System, Inc., Mihama, Fukui (Japan); Ohuchi, Hiroko; Akagi, Sigefumi; Natori, Kazuyuki [Japan Color Research Institute, Tokyo (Japan)

    2002-09-01

    This research was done to explain the way of color combinations for the signs that are excellent in the visibility. The research was composed by three experiments, color naming experiment and the visibility experiment 1 and 2. In the color naming experiment, what kind of color combinations investigated whether a target color could be judged precisely under the various lighting illuminant. The visibility experiment 1 examined the various color combinations that became effective for the visibility under the illuminant. And, the visibility experiment 2 examined the color combinations that were effective for the visibility from the lighting illuminant and the illuminance. Yellow in white background, white in yellow background, purple in red background, purple in green background, as for these 4 color combinations, it became clear that it is the color combination which needed attention under all the lighting illuminants from the color naming experiment and the visibility experiment 1. In the visibility experiment 2, relative visual acuity became more than 0.7 in all the lighting illuminants if there was a {delta}L{sup *} from the background and the target beyond 30 in the case of the illuminance of 5001x. And, when illuminance was 501x, it became clear that it become less than 0.7 by all the color schemes as for the relative visual acuity in all the lighting illuminants. (author)

  8. Cultural Transmission on the Taskscape: Exploring the Effects of Taskscape Visibility on Cultural Diversity.

    Science.gov (United States)

    Premo, L S; Tostevin, Gilbert B

    2016-01-01

    Culturally transmitted behavior can be structured in its performance both geographically and temporally, in terms of where and when implements are made and used on the landscape (what Ingold calls "the taskscape"). Yet cultural transmission theory has not yet explored the consequences of behaviors transmitted differently due to their enactment at different taskscape locations, what Tostevin calls "taskscape visibility." Here, we use computer simulations to explore how taskscape visibility and forager mobility affect the diversity of two selectively neutral culturally transmitted traits within a single population of social learners. The trait that can be transmitted from residential bases only (lower taskscape visibility) shows greater diversity than the trait that can be transmitted from residential bases and logistical camps (higher taskscape visibility). In addition, increased logistical mobility has a positive effect on the diversity of the trait with the lower taskscape visibility while it generally shows little to no effect on the diversity of the trait with higher taskscape visibility. Without an appreciation for the ways in which taskscape visibility and mobility can structure cultural transmission in space and through time, the difference in the observed equilibrium diversity levels of the two traits might be incorrectly interpreted as resulting from qualitatively different forms of biased cultural transmission. The results of our simulation experiment suggest that researchers may need to take the taskscape visibility into account when inferring cultural transmission from archaeological data.

  9. Visible Light Photocatalysis of [2+2] Styrene Cycloadditions via Energy Transfer

    Science.gov (United States)

    Lu, Zhan; Yoon, Tehshik P.

    2012-01-01

    Hip to be square: Styrenes participate in [2+2] cycloadditions upon irradiation with visible light in the presence of an iridium(III) polypyridyl complex. In contrast to previous reports of visible light photoredox catalysis, the mechanism of this process involves photosensitization by energy transfer and not electron transfer. PMID:22965321

  10. Dental magnetic resonance imaging: making the invisible visible.

    Science.gov (United States)

    Idiyatullin, Djaudat; Corum, Curt; Moeller, Steen; Prasad, Hari S; Garwood, Michael; Nixdorf, Donald R

    2011-06-01

    Clinical dentistry is in need of noninvasive and accurate diagnostic methods to better evaluate dental pathosis. The purpose of this work was to assess the feasibility of a recently developed magnetic resonance imaging (MRI) technique, called SWeep Imaging with Fourier Transform (SWIFT), to visualize dental tissues. Three in vitro teeth, representing a limited range of clinical conditions of interest, imaged using a 9.4T system with scanning times ranging from 100 seconds to 25 minutes. In vivo imaging of a subject was performed using a 4T system with a 10-minute scanning time. SWIFT images were compared with traditional two-dimensional radiographs, three-dimensional cone-beam computed tomography (CBCT) scanning, gradient-echo MRI technique, and histological sections. A resolution of 100 μm was obtained from in vitro teeth. SWIFT also identified the presence and extent of dental caries and fine structures of the teeth, including cracks and accessory canals, which are not visible with existing clinical radiography techniques. Intraoral positioning of the radiofrequency coil produced initial images of multiple adjacent teeth at a resolution of 400 μm. SWIFT MRI offers simultaneous three-dimensional hard- and soft-tissue imaging of teeth without the use of ionizing radiation. Furthermore, it has the potential to image minute dental structures within clinically relevant scanning times. This technology has implications for endodontists because it offers a potential method to longitudinally evaluate teeth where pulp and root structures have been regenerated. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  11. Mechanisms of interaction of monochromatic visible light with cells

    Science.gov (United States)

    Karu, Tiina I.

    1996-01-01

    Biological responses of cells to visible and near IR (laser) radiation occur due to physical and/or chemical changes in photoacceptor molecules, components of respiratory chains (cyt a/a3 in mitochondria). As a result of the photoexcitation of electronic states, the following physical and/or chemical changes can occur: alteration of redox properties and acceleration of electron transfer, changes in biochemical activity due to local transient heating of chromophores, one-electron auto-oxidation and O'2- production, and photodynamic action and 1O2 production. Different reaction channels can be activated to achieve the photobiological macroeffect. The primary physical and/or chemical changes induced by light in photoacceptor molecules are followed by a cascade of biochemical reactions in the cell that do not need further light activation and occur in the dark (photosignal transduction and amplification chains). These reactions are connected with changes in cellular homeostasis parameters. The crucial step here is thought to be an alteration of the cellular redox state: a shift towards oxidation is associated with stimulation of cellular vitality, and a shift towards reduction is linked to inhibition. Cells with a lower than normal pH, where the redox state is shifted in the reduced direction, are considered to be more sensitive to the stimulative action of light than those with the respective parameters being optimal or near optimal. This circumstance explains the possible variations in observed magnitudes of low- power laser effects. Light action on the redox state of a cell via the respiratory chain also explains the diversity of low-power laser effects. Besides explaining many controversies in the field of low-power laser effects (i.e., the diversity of effects, the variable magnitude or absence of effects in certain studies), the proposed redox-regulation mechanism may be a fundamental explanation for some clinical effects of irradiation, for example the positive

  12. VisibleWind: wind profile measurements at low altitude

    Science.gov (United States)

    Wilkerson, Tom; Bradford, Bill; Marchant, Alan; Apedaile, Tom; Wright, Cordell

    2009-09-01

    VisibleWindTM is developing an inexpensive rapid response system, for accurately characterizing wind shear and small scale wind phenomena in the boundary layer and for prospecting suitable locations for wind power turbines. The ValidWind system can also collect reliable "ground truth" for other remote wind sensors. The system employs small (0.25 m dia.) lightweight balloons and a tracker consisting of an Impulse 200 XL laser rangefinder coupled to a PC for automated data recording. Experiments on balloon trajectories demonstrate that the laser detection of range (+/- 0.5 m), together with measured azimuth and altitude, is an inexpensive, convenient, and capable alternative to other wind tracking methods. The maximum detection range has been increased to 2200 meters using micro-corner-cube retroreflector tape on balloons. Low power LEDs enable nighttime tracking. To avoid large balloon gyrations about the mean trajectory, we use balloons having low ascent rates and subcritical Reynolds numbers. Trajectory points are typically recorded every 4 - 7 seconds. Atmospheric features observed under conditions of inversions or "light and variable winds" include abrupt onsets of shear at altitudes of 100-250 m, velocity changes of order 1-3 m/s within layers of 10-20 m thickness, and veering of the wind direction by 180 degrees or more as altitude increases from 300 to 500 m. We have previously reported comparisons of balloon-based wind profiles with the output of a co-located sodar. Even with the Impulse rangefinder, our system still requires a "man in the loop" to track the balloon. A future system enhancement will automate balloon tracking, so that laser returns are obtained automatically at 1 Hz. While balloon measurements of large-scale, high altitude wind profiles are well known, this novel measurement system provides high-resolution, real-time characterization of the fluctuating local wind fields at the bottom of the boundary layer where wind power turbines and other

  13. Electrowetting Variable Optics for Visible and Infrared Applications

    Science.gov (United States)

    Watson, Alexander Maxwell

    Miniaturized variable optical devices are important for the fields of medical technology, optical communication, and consumer imaging devices. Areas ranging from endoscopy and optogenetics to atomic clocks and imaging all benefit from versatile optical systems. These applications all require precise and rapid control of imaging focal depth and lateral scanning. Electrowetting variable optics is one emergent technology that has the capability to provide focus tuning, beam steering, and even phase modulation in a small and robust package which requires no moving parts. Furthermore, electrowetting based devices there are attractive due to their transmissive nature, polarization insensitivity, low insertion loss, low electrical power requirements, and high optical quality. These features mean that electrowetting adaptive optical components are an attractive solution, compared with MEMS and liquid crystal optical components. Electrowetting is a technique that enables control of the shape of a liquid droplet with applied voltage. A conductive droplet on a dielectric surface alters its contact angle due to charges that build up between an underlying electrode and the surface of the droplet. This effect can be used to tune the curvature and tilt of liquids within cavities. The liquid boundary creates a high quality surface to use for lensing or steering applications. This thesis will focus on the development of electrowetting based lenses and prisms and applications in imaging for both visible and infrared wavelengths. Within this dissertation is the first demonstration of electrowetting lenses for phase control, as well as the investigation of non-aqueous electrowetting lens liquids for electrowetting lenses operation in the infrared. Key considerations that affect the performance and reliability are dielectric material and thickness, liquid selection and source of ionic conduction. The optical devices presented herein utilize judicious selection of dielectric material

  14. Frequency and importance of radiologically visible coronary scleroses

    International Nuclear Information System (INIS)

    Hoyer, B.

    1981-01-01

    The importance of radiologically visible coronary sceleroses for an early diagnosing of coronary heart disease was investigated. In 3 mixed collectives of patients with and without coronary heart diseases who had had a coronary angiography were examined retrospectively for coronary sclerosis (group I: standard films, group II: old X-ray findings, group III: fluoroscopy before beginning coronary angiography). In the retrospective evaluation, the sensitivity to the recognition of coronary heart disease was low. With prospective examination by means of fluoroscopy, coronary calcification could be proven in 37.66% of the patients with coronary diseases (sensitivity); the specificity (no coronary calcification in persons without coronary disease) was 99%. The duration and extent of a calcification do not show a definite influence on the severity of the disease. Several coronary scleroses in one or several vessels mostly indicate a vascular disease. Coronary scleroses are not necessarily located in the same point as coronary stenoses: in 85.5% of the patients with coronary sclerosis of the left truncus, haemodynamically important stenoses were found only in following vascular regions. Considering the high specificity of coronary scleroses in the fluoroscopic picture and the high sensitivity under favourable conditions, this method seems to be suitable as a screening method for early recognition of coronary heart diseases in the asymptomatic stage. A proven coronary sclerosis should in any case be the cause for continuing the search for a coronary heart disease. The radiation exposure during fluoroscopy of coronary sclerosis is low if the adjustment is correct, it takes little time, the patient is not put to discomfort. (orig./MG) [de

  15. Degree distributions of the visibility graphs mapped from fractional Brownian motions and multifractal random walks

    International Nuclear Information System (INIS)

    Ni Xiaohui; Jiang Zhiqiang; Zhou Weixing

    2009-01-01

    The dynamics of a complex system is usually recorded in the form of time series, which can be studied through its visibility graph from a complex network perspective. We investigate the visibility graphs extracted from fractional Brownian motions and multifractal random walks, and find that the degree distributions exhibit power-law behaviors, in which the power-law exponent α is a linear function of the Hurst index H of the time series. We also find that the degree distribution of the visibility graph is mainly determined by the temporal correlation of the original time series with minor influence from the possible multifractal nature. As an example, we study the visibility graphs constructed from three Chinese stock market indexes and unveil that the degree distributions have power-law tails, where the tail exponents of the visibility graphs and the Hurst indexes of the indexes are close to the α∼H linear relationship.

  16. Development of a visible light transmission (VLT) measurement system using an open-path optical method

    Science.gov (United States)

    Nurulain, S.; Manap, H.

    2017-09-01

    This paper describes about a visible light transmission (VLT) measurement system using an optical method. VLT rate plays an important role in order to determine the visibility of a medium. Current instrument to measure visibility has a gigantic set up, costly and mostly fails to function at low light condition environment. This research focuses on the development of a VLT measurement system using a simple experimental set-up and at a low cost. An open path optical technique is used to measure a few series of known-VLT thin film that act as sample of different visibilities. This measurement system is able to measure the light intensity of these thin films within the visible light region (535-540 nm) and the response time is less than 1s.

  17. Long-term atmospheric visibility trend in Southeast China, 1973-2010

    Science.gov (United States)

    Deng, Junjun; Du, Ke; Wang, Kai; Yuan, Chung-Shin; Zhao, Juanjuan

    2012-11-01

    Particulate matter (PM) pollution in Southeast China has been worsening because of the rapid industrial development and urbanization, which have significant negative effects on atmospheric visibility. Characterization of the trend in atmospheric visibility is important for evaluating the impact of PM pollution on the impairment of visual air quality in urban and rural areas. Long-term trend in atmospheric visibility in Southeast China was analyzed for the period of 1973-2010 based on the meteorological data from the National Climatic Data Center (NCDC) database using four statistical methods: annual mean visibility, percentages of “very good” visibility and “bad” visibility, ridit analysis, and cumulative percentiles. The relationship of atmospheric extinction with Air Pollution Index (API) was studied. In addition, the effects of recent environment policies on visibility were studied. The results showed that the visibility had decreased in 94% stations of this region and prefecture stations had the highest decreasing trend of -3.1 km/decade during the entire period. The average visibility of all the 17 stations (i.e., region-average) declined at a rate of -2.0 km/decade, with a 38-year average of 18.1 km. Decrease in the percentage of “very good” visibility and increase in the percentage of “bad” visibility existed in 14 and 16 stations, respectively. Region-average percentage of “bad” visibility was in the range of 2.2-21.5%, with an increasing rate of 5.0% per decade, and that of “very good” visibility was 24.4-71.8%, with a decreasing rate of -10.7% per decade. During the entire period, county and prefecture stations had similar changing patterns and trends in visibility, while town stations had the least worsening trends. Region-average visibility was better before 1988 while worse after 1993 when comparing to the entire period, with the transition period of 1988-1993. The worst 20%, 50% and best 20% of region-average visibility

  18. Characteristics of atmospheric visibility and its relationship with air pollution in Korea.

    Science.gov (United States)

    Lee, Jeong-Young; Jo, Wan-Kuen; Chun, Ho-Hwan

    2014-09-01

    Although analysis of long-term data is necessary to obtain reliable information on characteristics of atmospheric visibility and its relationship with air pollution, it has rarely been performed. Therefore, a long-term evaluation of atmospheric visibility in characteristically different Korean cities, as well as a remote island, during 2001 to 2009, was performed in this study. In general, visibility decreased in the studied areas during the 9-yr study period. In addition, all areas displayed a distinct seasonal trend, with high visibility in the cold season relative to the warm season. Weekday visibility, however, did not significantly differ from weekend visibility. Similarly, the number of days per year for both low (19 km) fluctuated during the study period. Busan (a coastal city) exhibited the highest visibility, with an overall average of 17.6 km, followed by Daegu (a basin city), Ulsan (with concentrated petrochemical industries), Ullungdo (a remote island), and Seoul (the capital of Korea). Visibility was found to be significantly correlated with target air pollutants, except for ozone, for all metropolitan cities, whereas it was significantly correlated only with particulate matter with an aerodynamic diameter <10 μm (PM10) and ozone on the remote island (Ullungdo). Among the metropolitan cities, Seoul exhibited the lowest visibility for both the PM10 standard exceedance and non-exceedance days, followed by Ulsan, Daegu, and Busan. The results of this study can be used to establish effective strategies for improving urban visibility and air quality. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  19. Visibility of the urethral meatus and risk of urinary tract infections in uncircumcised boys

    Science.gov (United States)

    Dubrovsky, Alexander Sasha; Foster, Bethany J.; Jednak, Roman; Mok, Elise; McGillivray, David

    2012-01-01

    Background: Uncircumcised boys are at higher risk for urinary tract infections than circumcised boys. Whether this risk varies with the visibility of the urethral meatus is not known. Our aim was to determine whether there is a hierarchy of risk among uncircumcised boys whose urethral meatuses are visible to differing degrees. Methods: We conducted a prospective cross-sectional study in one pediatric emergency department. We screened 440 circumcised and uncircumcised boys. Of these, 393 boys who were not toilet trained and for whom the treating physician had requested a catheter urine culture were included in our analysis. At the time of catheter insertion, a nurse characterized the visibility of the urethral meatus (phimosis) using a 3-point scale (completely visible, partially visible or nonvisible). Our primary outcome was urinary tract infection, and our primary exposure variable was the degree of phimosis: completely visible versus partially or nonvisible urethral meatus. Results: Cultures grew from urine samples from 30.0% of uncircumcised boys with a completely visible meatus, and from 23.8% of those with a partially or nonvisible meatus (p = 0.4). The unadjusted odds ratio (OR) for culture growth was 0.73 (95% confidence interval [CI] 0.35–1.52), and the adjusted OR was 0.41 (95% CI 0.17–0.95). Of the boys who were circumcised, 4.8% had urinary tract infections, which was significantly lower than the rate among uncircumcised boys with a completely visible urethral meatus (unadjusted OR 0.12 [95% CI 0.04–0.39], adjusted OR 0.07 [95% CI 0.02–0.26]). Interpretation: We did not see variation in the risk of urinary tract infection with the visibility of the urethral meatus among uncircumcised boys. Compared with circumcised boys, we saw a higher risk of urinary tract infection in uncircumcised boys, irrespective of urethral visibility. PMID:22777988

  20. Near infrared and visible face recognition based on decision fusion of LBP and DCT features

    Science.gov (United States)

    Xie, Zhihua; Zhang, Shuai; Liu, Guodong; Xiong, Jinquan

    2018-03-01

    Visible face recognition systems, being vulnerable to illumination, expression, and pose, can not achieve robust performance in unconstrained situations. Meanwhile, near infrared face images, being light- independent, can avoid or limit the drawbacks of face recognition in visible light, but its main challenges are low resolution and signal noise ratio (SNR). Therefore, near infrared and visible fusion face recognition has become an important direction in the field of unconstrained face recognition research. In order to extract the discriminative complementary features between near infrared and visible images, in this paper, we proposed a novel near infrared and visible face fusion recognition algorithm based on DCT and LBP features. Firstly, the effective features in near-infrared face image are extracted by the low frequency part of DCT coefficients and the partition histograms of LBP operator. Secondly, the LBP features of visible-light face image are extracted to compensate for the lacking detail features of the near-infrared face image. Then, the LBP features of visible-light face image, the DCT and LBP features of near-infrared face image are sent to each classifier for labeling. Finally, decision level fusion strategy is used to obtain the final recognition result. The visible and near infrared face recognition is tested on HITSZ Lab2 visible and near infrared face database. The experiment results show that the proposed method extracts the complementary features of near-infrared and visible face images and improves the robustness of unconstrained face recognition. Especially for the circumstance of small training samples, the recognition rate of proposed method can reach 96.13%, which has improved significantly than 92.75 % of the method based on statistical feature fusion.

  1. Development of softcopy environment for primary color banding visibility assessment

    Science.gov (United States)

    Min, Byungseok; Pizlo, Zygmunt; Allebach, Jan P.

    2008-01-01

    Fine-pitch banding is one of the most unwanted artifacts in laser electrophotographic (EP) printers. It is perceived as a quasiperiodic fluctuation in the process direction. Therefore, it is essential for printer vendors to know how banding is perceived by humans in order to improve print quality. Monochrome banding has been analyzed and assessed by many researchers; but there is no literature that deals with the banding of color laser printers as measured from actual prints. The study of color banding is complicated by the fact that the color banding signal is physically defined in a three-dimensional color space, while banding perception is described in a one-dimensional sense such as more banding or less banding. In addition, the color banding signal arises from the independent contributions of the four primary colorant banding signals. It is not known how these four distinct signals combine to give rise to the perception of color banding. In this paper, we develop a methodology to assess the banding visibility of the primary colorant cyan based on human visual perception. This is our first step toward studying the more general problem of color banding in combinations of two or more colorants. According to our method, we print and scan the cyan test patch, and extract the banding profile as a one dimensional signal so that we can freely adjust the intensity of banding. Thereafter, by exploiting the pulse width modulation capability of the laser printer, the extracted banding profile is used to modulate a pattern consisting of periodic lines oriented in the process direction, to generate extrinsic banding. This avoids the effect of the halftoning algorithm on the banding. Furthermore, to conduct various banding assessments more efficiently, we also develop a softcopy environment that emulates a hardcopy image on a calibrated monitor, which requires highly accurate device calibration throughout the whole system. To achieve the same color appearance as the hardcopy

  2. Isotope effects in photo dissociation of ozone with visible light

    Science.gov (United States)

    Früchtl, Marion; Janssen, Christof; Röckmann, Thomas

    2014-05-01

    Ozone (O3) plays a key role for many chemical oxidation processes in the Earth's atmosphere. In these chemical reactions, ozone can transfer oxygen to other trace gases. This is particularly interesting, since O3 has a very peculiar isotope composition. Following the mass dependent fractionation equation δ17O = 0.52 * δ18O, most fractionation processes depend directly on mass. However, O3 shows an offset to the mass dependent fractionation line. Processes, which show such anomalies, are termed mass independent fractionations (MIF). A very well studied example for a chemical reaction that leads to mass independent fractionation is the O3 formation reaction. To what degree O3 destruction reactions need to be considered in order to understand the isotope composition of atmospheric O3 is still not fully understood and an open question within scientific community. We set up new experiments to investigate the isotope effect resulting from photo dissociation of O3 in the Chappuis band (R1). Initial O3 is produced by an electric discharge. After photolysis O3 is collected in a cold trap at the triple point temperature of nitrogen (63K). O3 is then converted to O2 in order to measure the oxygen isotopes of O3 using isotope ratio mass spectrometry. To isolate O3 photo dissociation (R1) from O3 decomposition (R2) and secondary O3 formation (R3), we use varying amounts of carbon monoxide (CO) as O atom quencher (R4). In this way we suppress the O + O3 reaction (R3) and determine the isotope fractionation in R1 and R2 separately. We present first results on the isotope effects in O3 photo dissociation with visible light in the presence of different bath gases. Results are interpreted based on chemical kinetics modeling. (R1) O3 + hυ → O (3P) + O2 (R2) O3 + O (3P) → 2 O2 (R3) O + O2 + M → O3 + M (R4) O (3P) + CO + M → CO2 + M

  3. Accounting for Business Models: Increasing the Visibility of Stakeholders

    Directory of Open Access Journals (Sweden)

    Colin Haslam

    2015-01-01

    Full Text Available Purpose: This paper conceptualises a firm’s business model employing stakeholder theory as a central organising element to help inform the purpose and objective(s of business model financial reporting and disclosure. Framework: Firms interact with a complex network of primary and secondary stakeholders to secure the value proposition of a firm’s business model. This value proposition is itself a complex amalgam of value creating, value capturing and value manipulating arrangements with stakeholders. From a financial accounting perspective the purpose of the value proposition for a firm’s business model is to sustain liquidity and solvency as a going concern. Findings: This article argues that stakeholder relations impact upon the financial viability of a firm’s business model value proposition. However current financial reporting by function of expenses and the central organising objectives of the accounting conceptual framework conceal firm-stakeholder relations and their impact on reported financials. Practical implications: The practical implication of our paper is that ‘Business Model’ financial reporting would require a reorientation in the accounting conceptual framework that defines the objectives and purpose of financial reporting. This reorientation would involve reporting about stakeholder relations and their impact on a firms financials not simply reporting financial information to ‘investors’. Social Implications: Business model financial reporting has the potential to be stakeholder inclusive because the numbers and narratives reported by firms in their annual financial statements will increase the visibility of stakeholder relations and how these are being managed. What is original/value of paper: This paper’s original perspective is that it argues that a firm’s business model is structured out of stakeholder relations. It presents the firm’s value proposition as the product of value creating, capturing and

  4. Visualization of Penile Suspensory Ligamentous System Based on Visible Human Data Sets

    Science.gov (United States)

    Chen, Xianzhuo; Wu, Yi; Tao, Ling; Yan, Yan; Pang, Jun; Zhang, Shaoxiang; Li, Shirong

    2017-01-01

    Background The aim of this study was to use a three-dimensional (3D) visualization technology to illustrate and describe the anatomical features of the penile suspensory ligamentous system based on the Visible Human data sets and to explore the suspensory mechanism of the penis for the further improvement of the penis-lengthening surgery. Material/Methods Cross-sectional images retrieved from the first Chinese Visible Human (CVH-1), third Chinese Visible Human (CVH-3), and Visible Human Male (VHM) data sets were used to segment the suspensory ligamentous system and its adjacent structures. The magnetic resonance imaging (MRI) images of this system were studied and compared with those from the Visible Human data sets. The 3D models reconstructed from the Visible Human data sets were used to provide morphological features of the penile suspensory ligamentous system and its related structures. Results The fundiform ligament was a superficial, loose, fibro-fatty tissue which originated from Scarpa’s fascia superiorly and continued to the scrotal septum inferiorly. The suspensory ligament and arcuate pubic ligament were dense fibrous connective tissues which started from the pubic symphysis and terminated by attaching to the tunica albuginea of the corpora cavernosa. Furthermore, the arcuate pubic ligament attached to the inferior rami of the pubis laterally. Conclusions The 3D model based on Visible Human data sets can be used to clarify the anatomical features of the suspensory ligamentous system, thereby contributing to the improvement of penis-lengthening surgery. PMID:28530218

  5. The effect of visible facial difference on personal space during encounters with the general public.

    Science.gov (United States)

    Roberts, R M; Gierasch, A

    2013-01-01

    Previous research has found that people with visible differences are granted more physical space than people without visible differences during encounters with the general public. This study aimed to examine whether given significant sociocultural changes, this remains the case in contemporary Australia. The personal space afforded to a person with a visible difference (with a temporary difference--a scar and a permanent difference--a strawberry hemangioma) or a person without a visible difference by 408 pedestrians on a busy pedestrian walkway in the central business district of Adelaide, Australia, was measured. This was a replication and extension of a study by N. Rumsey, R. Bull, and D. Gahagan (1982). Pedestrians stood no further away from the model in the visibly different conditions than in the nonvisibly different conditions. Pedestrians stood an average of 128 cm away in the control condition, 120 cm away in the scar condition, and 140 cm away in the birthmark condition. People did not stand to the nonvisibly different (left) side of the model more frequently in the visibly different conditions than in the nonvisibly different conditions. As the original research by N. Rumsey et al. is frequently cited as representing the current situation for people with visible differences, failing to replicate the result is significant. Changes may be due to either recent sociocultural changes promoting inclusion of disability or increasing social taboo against expressing overt prejudice.

  6. Ghost imaging and its visibility with partially coherent elliptical Gaussian Schell-model beams

    International Nuclear Information System (INIS)

    Luo, Meilan; Zhu, Weiting; Zhao, Daomu

    2015-01-01

    The performances of the ghost image and the visibility with partially coherent elliptical Gaussian Schell-model beams have been studied. In that case we have derived the condition under which the goal ghost image is achievable. Furthermore, the visibility is assessed in terms of the parameters related to the source to find that the visibility reduces with the increase of the beam size, while it is a monotonic increasing function of the transverse coherence length. More specifically, it is found that the inequalities of the source sizes in x and y directions, as well as the transverse coherence lengths, play an important role in the ghost image and the visibility. - Highlights: • We studied the ghost image and visibility with partially coherent EGSM beams. • We derived the condition under which the goal ghost image is achievable. • The visibility is assessed in terms of the parameters related to the source. • The source sizes and coherence lengths play role in the ghost image and visibility.

  7. The Impact of Visibility on Teamwork, Collaborative Communication, and Security in Emergency Departments: An Exploratory Study.

    Science.gov (United States)

    Gharaveis, Arsalan; Hamilton, D Kirk; Pati, Debajyoti; Shepley, Mardelle

    2017-01-01

    The aim of this study was to examine the influence of visibility on teamwork, collaborative communication, and security issues in emergency departments (EDs). This research explored whether with high visibility in EDs, teamwork and collaborative communication can be improved while the security issues will be reduced. Visibility has been regarded as a critical design consideration and can be directly and considerably impacted by ED's physical design. Teamwork is one of the major related operational outcomes of visibility and involves nurses, support staff, and physicians. The collaborative communication in an ED is another important factor in the process of care delivery and affects efficiency and safety. Furthermore, security is a behavioral factor in ED designs, which includes all types of safety including staff safety, patient safety, and the safety of visitors and family members. This qualitative study investigated the impact of visibility on teamwork, collaborative communication, and security issues in the ED. One-on-one interviews and on-site observation sessions were conducted in a community hospital. Corresponding data analysis was implemented by using computer plan analysis, observation and interview content, and theme analyses. The findings of this exploratory study provided a framework to identify visibility as an influential factor in ED design. High levels of visibility impact productivity and efficiency of teamwork and communication and improve the chance of lowering security issues. The findings of this study also contribute to the general body of knowledge about the effect of physical design on teamwork, collaborative communication, and security.

  8. Development of a Statistical Model for Forecasting Episodes of Visibility Degradation in the Denver Metropolitan Area.

    Science.gov (United States)

    Reddy, P. J.; Barbarick, D. E.; Osterburg, R. D.

    1995-03-01

    In 1990, the State of Colorado implemented a visibility standard of 0.076 km1 of beta extinction for the Denver metropolitan area. Meteorologists with Colorado's Air Pollution Control Division forecast high pollution days associated with visibility impairment as well as those due to high levels of the federal criteria pollutants. Visibility forecasts are made from a few hours up to about 26 h in advance of the period of interest. Here we discuss the key microscale, mesoscale, and synoptic-scale features associated with episodes of visibility impairment. Data from special studies, case studies, and the 22 NOAA Program for Regional Observing and Forecasting Services mesonet sites have been invaluable in identifying patterns associated with extremes in visibility conditions. A preliminary statistical forecast model has been developed using variables that represent many of these patterns. Six variables were selected from an initial pool of 27 to be used in a model based on linear logistic regression. These six variables include forecast measures of snow cover, surface pressures and a surface pressure gradient in eastern Colorado, relative humidity, and 500-mb ridge position. The initial testing of the model has been encouraging. The model correctly predicted 76% of the good visibility days and 67% of the poor visibility days for a test set of 171 days.

  9. An Automated Self-Learning Quantification System to Identify Visible Areas in Capsule Endoscopy Images.

    Science.gov (United States)

    Hashimoto, Shinichi; Ogihara, Hiroyuki; Suenaga, Masato; Fujita, Yusuke; Terai, Shuji; Hamamoto, Yoshihiko; Sakaida, Isao

    2017-08-01

    Visibility in capsule endoscopic images is presently evaluated through intermittent analysis of frames selected by a physician. It is thus subjective and not quantitative. A method to automatically quantify the visibility on capsule endoscopic images has not been reported. Generally, when designing automated image recognition programs, physicians must provide a training image; this process is called supervised learning. We aimed to develop a novel automated self-learning quantification system to identify visible areas on capsule endoscopic images. The technique was developed using 200 capsule endoscopic images retrospectively selected from each of three patients. The rate of detection of visible areas on capsule endoscopic images between a supervised learning program, using training images labeled by a physician, and our novel automated self-learning program, using unlabeled training images without intervention by a physician, was compared. The rate of detection of visible areas was equivalent for the supervised learning program and for our automatic self-learning program. The visible areas automatically identified by self-learning program correlated to the areas identified by an experienced physician. We developed a novel self-learning automated program to identify visible areas in capsule endoscopic images.

  10. Irradiation of skin with visible light induces reactive oxygen species and matrix-degrading enzymes.

    Science.gov (United States)

    Liebel, Frank; Kaur, Simarna; Ruvolo, Eduardo; Kollias, Nikiforos; Southall, Michael D

    2012-07-01

    Daily skin exposure to solar radiation causes cells to produce reactive oxygen species (ROS), which are a primary factor in skin damage. Although the contribution of the UV component to skin damage has been established, few studies have examined the effects of non-UV solar radiation on skin physiology. Solar radiation comprises UV, and thus the purpose of this study was to examine the physiological response of skin to visible light (400-700 nm). Irradiation of human skin equivalents with visible light induced production of ROS, proinflammatory cytokines, and matrix metalloproteinase (MMP)-1 expression. Commercially available sunscreens were found to have minimal effects on reducing visible light-induced ROS, suggesting that UVA/UVB sunscreens do not protect the skin from visible light-induced responses. Using clinical models to assess the generation of free radicals from oxidative stress, higher levels of free radical activity were found after visible light exposure. Pretreatment with a photostable UVA/UVB sunscreen containing an antioxidant combination significantly reduced the production of ROS, cytokines, and MMP expression in vitro, and decreased oxidative stress in human subjects after visible light irradiation. Taken together, these findings suggest that other portions of the solar spectrum aside from UV, particularly visible light, may also contribute to signs of premature photoaging in skin.

  11. IR visible sum-frequency vibrational spectroscopy of Biphenyl-3 methylene thiol monolayer on gold and silver: effect of the visible wavelength on the SFG spectrum

    Science.gov (United States)

    Humbert, C.; Dreesen, L.; Mani, A. A.; Caudano, Y.; Lemaire, J.-J.; Thiry, P. A.; Peremans, A.

    2002-04-01

    We measured IR-visible sum-frequency generation spectra of CH 3-(C 6H 4) 2-(CH 2) 3-S-H (Biphenyl-3) self-assembled monolayers on a silver and a gold substrate. For the latter substrate, we observed different interference patterns between the resonant signal of the CH vibration and the non-resonant contribution of the substrate as a function of the visible beam wavelength. The non-linear response of the gold substrate is enhanced around 480 nm corresponding to the s-d interband transition. Such effect is not observed for the silver substrate the interband transition of which is located out of the investigated visible spectral range of 450-700 nm.

  12. CT-Guided Biopsy of Small Liver Lesions: Visibility, Artifacts, and Corresponding Diagnostic Accuracy

    International Nuclear Information System (INIS)

    Stattaus, Joerg; Kuehl, Hilmar; Ladd, Susanne; Schroeder, Tobias; Antoch, Gerald; Baba, Hideo A.; Barkhausen, Joerg; Forsting, Michael

    2007-01-01

    Purpose. Our study aimed to determine the visibility of small liver lesions during CT-guided biopsy and to assess the influence of lesion visibility on biopsy results. Material and Methods. Fifty patients underwent CT-guided core biopsy of small focal liver lesions (maximum diameter, 3 cm); 38 biopsies were performed using noncontrast CT, and the remaining 12 were contrast-enhanced. Visibility of all lesions was graded on a 4-point-scale (0 = not visible, 1 = poorly visible, 2 = sufficiently visible, 3 = excellently visible) before and during biopsy (with the needle placed adjacent to and within the target lesion). Results. Forty-three biopsies (86%) yielded diagnostic results, and seven biopsies were false-negative. In noncontrast biopsies, the rate of insufficiently visualized lesions (grades 0-1) increased significantly during the procedure, from 10.5% to 44.7%, due to needle artifacts. This resulted in more (17.6%) false-negative biopsy results compared to lesions with good visualization (4.8%), although this difference lacks statistical significance. Visualization impairment appeared more often with an intercostal or subcostal vs. an epigastric access and with a subcapsular vs. a central lesion location, respectively. With contrast-enhanced biopsy the visibility of hepatic lesions was only temporarily improved, with a risk of complete obscuration in the late phase. Conclusion. In conclusion, visibility of small liver lesions diminished significantly during CT-guided biopsy due to needle artifacts, with a fourfold increased rate of insufficiently visualized lesions and of false-negative histological results. Contrast enhancement did not reveal better results

  13. Asymmetry and sexual dimorphism of the medial frontal gyrus visible surface in humans

    Directory of Open Access Journals (Sweden)

    Spasojević Goran

    2010-01-01

    Full Text Available Background/Aim. Studies of visible (extrasulcal surface of the brain hemispheres are not feasible for measurements of the brain size, but are valuable for analysis and quantification of sexual dimorphism and/or asymmetries of the human brain. Morphological and morphometric investigations of the brain may contribute in genetic studies of the human nervous system. The aim of this study was to determine and to quantify sexual dimorphism and the right/left morphological asymmetry of the visible surface of medial frontal gyrus (gyrus frontalis medialis - GFM. Methods. Measurements and analysis of the visible surface of GFM were done on 84 hemispheres (42 brains from the persons of both sexes: 26 males and 16 females, 20-65 years of age. After fixation in 10% formalin and dissection, digital morphometric measurements were performed. We studied these in relation to the side of the hemisphere and the person's sex. Standardized digital AutoCAD planimetry of the visible surface of GFM was enabled by the use of coordinate system of intercommissural line. Results. In the whole sample, the visible surface of the right GFM (21.39 cm2 was statistically significantly greater (p < 0.05 than the left GFM (18.35 cm2 indicating the right/left asymmetry of the visible surface of GFM. Also, the visible surface of the right GFM in the males (22.66 cm2 was significantly greater (p < 0.05 than in the females (19.35 cm2, while the difference in size of the left GFM between the males and the females was not significant (p > 0.05. Conclusion. Morphological analysis of visible surface of GFM performed by digital planimetry showed sexual dimorphism of the visible surface and the presence of right/left asymmetry of GFM.

  14. Visible photoluminescence from hydrogenated silicon particles suspended in a silane plasma

    International Nuclear Information System (INIS)

    Courteille, C.; Dorier, J.L.; Dutta, J.; Hollenstein, C.; Howling, A.A.; Stoto, T.

    1994-09-01

    Visible photoluminescence at room temperature has been observed in amorphous hydrogenated silicon particulates during their formation in a silane radio-frequency plasma. Oxygen injection along with mass spectrometry measurements demonstrate that oxygen has no influence on the photoluminescence. The appearance of visible photoluminescence coincides with a particle agglomeration phase as shown by laser light scattering experiments, and electron microscopy shows silicon nanocrystals within these particulates. These observations of visible photoluminescence are consistent with the model of quantum confinement in the silicon nanocrystals. (author) 5 figs., 45 refs

  15. Dark and visible matter in a baryon-symmetric universe via the Affleck-Dine mechanism

    International Nuclear Information System (INIS)

    Bell, Nicole F.; Petraki, Kalliopi; Volkas, Raymond R.; Shoemaker, Ian M.

    2011-01-01

    The similarity of the visible and dark matter abundances indicates that they may originate via the same mechanism. If both the dark and visible matter are charged under a generalized baryon number, then the asymmetry of the visible sector may be compensated by an asymmetry in the dark sector. We show how the separation of the baryonic and the -antibaryonic charge can originate in the vacuum, via the Affleck-Dine mechanism, due to the breaking of a symmetry orthogonal to the baryon number. Symmetry restoration in the current epoch guarantees the individual stability of the two sectors.

  16. Visibility, Power and Citizen Intervention: The Five Eyes and New Zealand’s Southern Cross Cable

    DEFF Research Database (Denmark)

    McCrow-Young, Ally

    2017-01-01

    government, as part of the Five Eyes intelligence community, had been collecting data on the population by tapping the Southern Cross Cable. ‘If you live in New Zealand,’ Snowden wrote, ‘you are being watched.’ This article examines the relationship between power and visibility; specifically how creative...... citizen engagement can serve to reveal structures of power surrounding global politics and surveillance. Visibility is a central concept, extending beyond issues of local visibility at the micro level, into the networked, global environment through online media. The significance of the cable landing point...

  17. Media visibility on the formation of female celebrity: Catarina, a virgin for auction

    Directory of Open Access Journals (Sweden)

    Lígia Campos de Cerqueira Lana

    2013-09-01

    Full Text Available This article analyzes the role of media visibility in the rise of CatherineMigliorini’s celebrity, famous after putting her virginity up for auction oninternet. The history of the case and its main events, texts written by experts, images and statements of Catarina are investigated from the perspective of women’s visibility transformations. Although media critique, the celebrity Catarina displayed expected abilities of women in media visibility, as the possession of a sexy, young and assertive body, able to be used as capital.

  18. Finding the UV-Visible Path Forward: Proceedings of the Community Workshop to Plan the Future of UV/Visible Space Astrophysics

    OpenAIRE

    Scowen, Paul A.; Tripp, Todd; Beasley, Matt; Ardila, David; Andersson, B-G; Apellániz, Jesús Maíz; Barstow, Martin; Bianchi, Luciana; Calzetti, Daniela; Clampin, Mark; Evans, Christopher J.; France, Kevin; García, Miriam García; de Castro, Ana Gomez; Harris, Walt

    2016-01-01

    We present the science cases and technological discussions that came from the workshop titled ¿Finding the ultraviolet (UV)-Visible Path Forward¿ held at NASA GSFC 2015 June 25-26. The material presented outlines the compelling science that can be enabled by a next generation space-based observatory dedicated for UV¿visible science, the technologies that are available to include in that observatory design, and the range of possible alternative launch approaches that could also enable some of ...

  19. NOAA Climate Data Record (CDR) of Visible and Near Infrared Reflectance from AVHRR, Version 1.0

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The AVHRR visible gains and offsets convert GAC pixel level counts to radiances and are provided for each visible band encompassing TIROS-N, NOAA-6 through NOAA-19...

  20. Prolegomenon for an ethics of visibility in Hannah Arendt

    Directory of Open Access Journals (Sweden)

    Bethânia Assy

    2004-12-01

    Full Text Available This paper aims to discuss the Arendtian notions of appearance and perception in order to promote a displacement of those conceptions from the generally associated domain of passive apprehension of the faculty of knowledge towards the domain of a praxiology of action and language, based on an active perception. Arendt's appropriations on the Heideggerian "to take one's place" (sich hin-stellen will be discussed, as well as the Augustinian "finding oneself in the world" (diligere. A twofold disposition of appearance will be distinguished: producing and position, whose transposed to the Arendtian notion of world correspond, respectively, to fabrication (poiesis of the world, man's objective in-between space, and to action (praxis in the world, man's subjective in-between space. Those conceptual replacements, in a broad sense, uphold a closer imbrication between the activities of the mind and acting, stricto sensu, and consequently, foment not only the valorization of the public space, but the visibility of our acts and deeds as well, calling out the dignity of appearance in ethics.Este trabalho tem como objetivo discutir as noções arendtianas de aparência e percepção, a fim de promover um deslocamento dessas concepções do domínio geralmente associado da apreensão passiva da faculdade de conhecimento em direção a uma praxiologia da ação e da linguagem, baseada na percepção ativa. As apropriações de Arendt do "apresentar-se como" (sich hin-stellen heideggeriano serão discutidas, bem como o "achar-se no mundo" (diligere agostiniano. Será feita a distinção de uma dupla disposição da aparência: produção e posição, que transpostas para a noção arendtiana de mundo correspondem, respectivamente, à fabricação (poiesis do mundo, o espaço-entre objetivo do homem, e à ação (praxis no mundo, o espaço-entre subjetivo do homem. Essas substituições conceituais, em sentido mais amplo, sustentam uma imbricação mais pr

  1. NOAA JPSS Visible Infrared Imaging Radiometer Suite (VIIRS) Snow Cover Environmental Data Record (EDR) from NDE

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a high quality operational Environmental Data Record (EDR) of snow cover from the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument...

  2. Toxic effect of visible light on Drosophila lifespan depending upon diet protein content.

    Science.gov (United States)

    Shen, Jie; Zhu, Xiang; Gu, Yitian; Zhang, Chiqian; Huang, Jiahong; Qing, Xiao

    2018-03-01

    We investigated the toxic effect of visible light on Drosophila lifespan in both sexes. The toxic effect of ultraviolet (UV) light on organisms is well known. However, the effects of illumination with visible light remain unclear. Here, we found that visible light could be toxic to Drosophila survival, depending on the protein content in diet. In addition, further analysis revealed significant interaction between light and sex, and showed that strong light shortened life span by causing opposite direction changes in mortality rate parameters in females versus males. Our findings suggest that photoageing may be a general phenomenon, and support the theory of sexual antagonistic pleiotropy in aging intervention. The results caution that exposure to visible light could be hazardous to life span and suggest that identification of the underlying mechanism would allow better understanding of aging intervention.

  3. Reduced graphene oxide and Ag wrapped TiO2 photocatalyst for enhanced visible light photocatalysis

    International Nuclear Information System (INIS)

    Leong, Kah Hon; Sim, Lan Ching; Jang, Min; Ibrahim, Shaliza; Bahnemann, Detlef; Saravanan, Pichiah

    2015-01-01

    A well-organised reduced graphene oxide (RGO) and silver (Ag) wrapped TiO 2 nano-hybrid was successfully achieved through a facile and easy route. The inherent characteristics of the synthesized RGO-Ag/TiO 2 were revealed through crystalline phase, morphology, chemical composition, Raman scattering, UV-visible absorption, and photoluminescence analyses. The adopted synthesis route significantly controlled the uniform formation of silver nanoparticles and contributed for the absorption of light in the visible spectrum through localized surface plasmon resonance effects. The wrapped RGO nanosheets triggered the electron mobility and promoted visible light shift towards red spectrum. The accomplishment of synergised effect of RGO and Ag well degraded Bisphenol A under visible light irradiation with a removal efficiency of 61.9%

  4. Nanostructure sensitization of transition metal oxides for visible-light photocatalysis

    Directory of Open Access Journals (Sweden)

    Hongjun Chen

    2014-05-01

    Full Text Available To better utilize the sunlight for efficient solar energy conversion, the research on visible-light active photocatalysts has recently attracted a lot of interest. The photosensitization of transition metal oxides is a promising approach for achieving effective visible-light photocatalysis. This review article primarily discusses the recent progress in the realm of a variety of nanostructured photosensitizers such as quantum dots, plasmonic metal nanostructures, and carbon nanostructures for coupling with wide-bandgap transition metal oxides to design better visible-light active photocatalysts. The underlying mechanisms of the composite photocatalysts, e.g., the light-induced charge separation and the subsequent visible-light photocatalytic reaction processes in environmental remediation and solar fuel generation fields, are also introduced. A brief outlook on the nanostructure photosensitization is also given.

  5. NOAA JPSS Visible Infrared Imaging Radiometer Suite (VIIRS) Smoothed Normalized Difference Vegetation Index (NDVI) from NDE

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Visible Infrared Imaging Radiometer Suite (VIIRS) Smoothed Normalized Difference Vegetation Index (NDVI) from NDE is a weekly product derived from the VIIRS...

  6. NOAA JPSS Visible Infrared Imaging Radiometer Suite (VIIRS) Aerosol Detection Environmental Data Record (EDR) from NDE

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a high quality operational Environmental Data Record (EDR) of suspended matter from the Visible Infrared Imaging Radiometer Suite (VIIRS)...

  7. Thermal Infrared and Visible to Near-Infrared Spectral Analysis of Chert and Amorphous Silica

    Science.gov (United States)

    McDowell, M. L.; Hamilton, V. E.; Cady, S. L.; Knauth, P.

    2009-03-01

    We look in detail at the thermal infrared and visible to near-infrared spectra of various forms of chert and amorphous silica and compare the spectral variations between samples with variations in physical and chemical characteristics.

  8. Aerobic oxidation of alcohols in visible light on Pd-grafted Ti cluster

    Science.gov (United States)

    The titanium cluster with the reduced band gap has been synthesized having the palladium nanoparticles over the surface, which not only binds to the atmospheric oxygen but also catalyzes the oxidation of alcohols under visible light.

  9. Visible light photoreduction of CO.sub.2 using heterostructured catalysts

    Science.gov (United States)

    Matranga, Christopher; Thompson, Robert L; Wang, Congjun

    2015-03-24

    The method provides for use of sensitized photocatalyst for the photocatalytic reduction of CO.sub.2 under visible light illumination. The photosensitized catalyst is comprised of a wide band gap semiconductor material, a transition metal co-catalyst, and a semiconductor sensitizer. The semiconductor sensitizer is photoexcited by visible light and forms a Type II band alignment with the wide band gap semiconductor material. The wide band gap semiconductor material and the semiconductor sensitizer may be a plurality of particles, and the particle diameters may be selected to accomplish desired band widths and optimize charge injection under visible light illumination by utilizing quantum size effects. In a particular embodiment, CO.sub.2 is reduced under visible light illumination using a CdSe/Pt/TiO2 sensitized photocatalyst with H.sub.2O as a hydrogen source.

  10. Simulation of three lanes one-way freeway in low visibility weather by possible traffic accidents

    Science.gov (United States)

    Pang, Ming-bao; Zheng, Sha-sha; Cai, Zhang-hui

    2015-09-01

    The aim of this work is to investigate the traffic impact of low visibility weather on a freeway including the fraction of real vehicle rear-end accidents and road traffic capacity. Based on symmetric two-lane Nagel-Schreckenberg (STNS) model, a cellular automaton model of three-lane freeway mainline with the real occurrence of rear-end accidents in low visibility weather, which considers delayed reaction time and deceleration restriction, was established with access to real-time traffic information of intelligent transportation system (ITS). The characteristics of traffic flow in different visibility weather were discussed via the simulation experiments. The results indicate that incoming flow control (decreasing upstream traffic volume) and inputting variable speed limits (VSL) signal are effective in accident reducing and road actual traffic volume's enhancing. According to different visibility and traffic demand the appropriate control strategies should be adopted in order to not only decrease the probability of vehicle accidents but also avoid congestion.

  11. EPA Sets Schedule to Improve Visibility in the Nation's Most Treasured Natural Areas

    Science.gov (United States)

    EPA issued a schedule to act on more than 40 state pollution reduction plans that will improve visibility in national parks and wilderness areas and protect public health from the damaging effects of the pollutants that cause regional haze.

  12. EVALUATION AND MITIGATION OF VISIBLE ACIDIC AEROSOL PLUMES FROM COAL FIRED POWER BOILERS

    Science.gov (United States)

    The formation of sulfur trioxide during the combustion of coal can increase significantly following the installation and operation of selective catalytic reduction systems for reduction of nitrogen oxides. This can in turn lead to adverse environmental impacts, including visible...

  13. Effect of vehicle color and background visibility for improving safety on rural Kansas highways.

    Science.gov (United States)

    2015-06-01

    The effect of vehicle color on crash involvement has been an interesting topic for several decades; however, the effect of a vehicles : color on its visibility to drivers has not been studied in detail, especially at rural intersections. There has...

  14. Sustainable Strategy Utilizing Biomass: Visible-Light-Mediated Synthesis of gamma-Valerolactone

    Data.gov (United States)

    U.S. Environmental Protection Agency — A novel sustainable approach to valued g-valerolactone was investigated. This approach exploits the visible-light-mediated conversion of biomass-derived levulinic...

  15. NOAA JPSS Visible Infrared Imaging Radiometer Suite (VIIRS) Sensor Data Record (SDR) from IDPS

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sensor Data Records (SDRs), or Level 1b data, from the Visible Infrared Imaging Radiometer Suite (VIIRS) are the calibrated and geolocated radiance and reflectance...

  16. Continuous Flow Science in an Undergraduate Teaching Laboratory: Photocatalytic Thiol-Ene Reaction Using Visible Light

    Science.gov (United States)

    Santandrea, Jeffrey; Kairouz, Vanessa; Collins, Shawn K.

    2018-01-01

    An undergraduate teaching laboratory experiment involving a continuous flow, photocatalytic thiol-ene reaction using visible-light irradiation is described that allows students to explore concepts of green chemistry, photochemistry, photocatalysis, and continuous flow chemistry.

  17. 2D Organic-Inorganic Hybrid Thin Films for Flexible UV-Visible Photodetectors

    KAUST Repository

    Velusamy, Dhinesh Babu; Haque, Mohammed; Parida, Manas R.; Zhang, Fan; Wu, Tao; Mohammed, Omar F.; Alshareef, Husam N.

    2017-01-01

    photodetection suitable for both UV and visible light with good responsivity, detectivity, and reliable and rapid photoswitching characteristics comparable to monolayer devices. This excellent performance is retained even after the films are severely deformed

  18. UV-B sensitivity of plant photosynthesis as influenced by visible irradiation

    International Nuclear Information System (INIS)

    Caldwell, M.M.; Warner, C.W.

    1982-01-01

    Experiments were made to separate the effects of preconditioning and concomitant visible irradiation and to investigate this with respect to both light-limited and light-saturated photosynthesis. (orig./AJ)

  19. Robust rooftop extraction from visible band images using higher order CRF

    KAUST Repository

    Li, Er; Femiani, John; Xu, Shibiao; Zhang, Xiaopeng; Wonka, Peter

    2015-01-01

    In this paper, we propose a robust framework for building extraction in visible band images. We first get an initial classification of the pixels based on an unsupervised presegmentation. Then, we develop a novel conditional random field (CRF

  20. NOAA JPSS Visible Infrared Imaging Radiometer Suite (VIIRS) Cloud Mask Environmental Data Record (EDR) from NDE

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains a high quality Environmental Data Record (EDR) of cloud masks from the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument onboard...

  1. Single underwater image enhancement based on color cast removal and visibility restoration

    Science.gov (United States)

    Li, Chongyi; Guo, Jichang; Wang, Bo; Cong, Runmin; Zhang, Yan; Wang, Jian

    2016-05-01

    Images taken under underwater condition usually have color cast and serious loss of contrast and visibility. Degraded underwater images are inconvenient for observation and analysis. In order to address these problems, an underwater image-enhancement method is proposed. A simple yet effective underwater image color cast removal algorithm is first presented based on the optimization theory. Then, based on the minimum information loss principle and inherent relationship of medium transmission maps of three color channels in an underwater image, an effective visibility restoration algorithm is proposed to recover visibility, contrast, and natural appearance of degraded underwater images. To evaluate the performance of the proposed method, qualitative comparison, quantitative comparison, and color accuracy test are conducted. Experimental results demonstrate that the proposed method can effectively remove color cast, improve contrast and visibility, and recover natural appearance of degraded underwater images. Additionally, the proposed method is comparable to and even better than several state-of-the-art methods.

  2. The parametric modified limited penetrable visibility graph for constructing complex networks from time series

    Science.gov (United States)

    Li, Xiuming; Sun, Mei; Gao, Cuixia; Han, Dun; Wang, Minggang

    2018-02-01

    This paper presents the parametric modified limited penetrable visibility graph (PMLPVG) algorithm for constructing complex networks from time series. We modify the penetrable visibility criterion of limited penetrable visibility graph (LPVG) in order to improve the rationality of the original penetrable visibility and preserve the dynamic characteristics of the time series. The addition of view angle provides a new approach to characterize the dynamic structure of the time series that is invisible in the previous algorithm. The reliability of the PMLPVG algorithm is verified by applying it to three types of artificial data as well as the actual data of natural gas prices in different regions. The empirical results indicate that PMLPVG algorithm can distinguish the different time series from each other. Meanwhile, the analysis results of natural gas prices data using PMLPVG are consistent with the detrended fluctuation analysis (DFA). The results imply that the PMLPVG algorithm may be a reasonable and significant tool for identifying various time series in different fields.

  3. Preliminary results of algorithms to determine horizontal and vertical underwater visibilities of coastal waters

    Digital Repository Service at National Institute of Oceanography (India)

    Suresh, T.; Joshi, Shreya; Talaulikar, M.; Desa, E.J.

    the underwater average cosine. These algorithms for vertical and horizontal visibilities have been validated for the coastal waters of Goa with the measured and those derived from the ocean color data of OCM-2 and MODIS...

  4. Effect of vehicle color and background visibility for improving safety on rural Kansas highways : [technical summary].

    Science.gov (United States)

    2015-06-01

    The effect of vehicle color on crash involvement has been an interesting topic for several : decades; however, the effect of vehicle color on its visibility to drivers has not been : studied in detail, especially at rural intersections. There has bee...

  5. The 2007 click it or ticket high-visibility seat belt mobilization : traffic tech.

    Science.gov (United States)

    2010-09-01

    In May 2007 the National Highway Traffic Safety Administration : sponsored the fifth national Click It or Ticket (CIOT) : high-visibility seat belt enforcement mobilization, which followed : the CIOT program model of earned and paid media : publicizi...

  6. Photochromism of indolino-benzopyrans studied by NMR and UV-visible spectroscopy

    Directory of Open Access Journals (Sweden)

    S. Delbaere

    2006-01-01

    is described. The structures of photomerocyanines elucidated by NMR spectroscopy and spectrokinetic data (λmax⁡ of colored form, colorability, and rate constant of bleaching obtained by UV-visible spectroscopy are reported.

  7. A Webometric Investigation of Visibility and Collaboration of Iranian Nanotechnology Websites

    Directory of Open Access Journals (Sweden)

    Faramarz Sohili

    2007-07-01

    Full Text Available The present investigation intends to review the extent of visibility, impact and collaboration of Iranian nanotechnology websites using webometric method of link analysis. The sample consists of all websites dealing with nanotechnology in Iran. Findings showed that these sites have low visibility, web impact factor and page count. Iranian Nanotechnology Initiative, Nano Ideas and Iranian Nanotechnology Association had the highest number of inlinks and therefore highest visibility, while Nanotechnology Department Website had the lowest visibility. Findings also indicated that Amir Kabir Technical University Nanotechnology Committee website, Iran Nanotechnology initiative and Nano Ideas websites had the highest web impact factor, while Kashan University Institute for Nano Science and Technology had the lowest web impact factor. It was further established that Iranian Nanotech websites collaborate within two clusters. A Multi-dimensional scale was used.

  8. An assessment of the visibility of MeSH-indexed medical web catalogs through search engines.

    Science.gov (United States)

    Zweigenbaum, P; Darmoni, S J; Grabar, N; Douyère, M; Benichou, J

    2002-01-01

    Manually indexed Internet health catalogs such as CliniWeb or CISMeF provide resources for retrieving high-quality health information. Users of these quality-controlled subject gateways are most often referred to them by general search engines such as Google, AltaVista, etc. This raises several questions, among which the following: what is the relative visibility of medical Internet catalogs through search engines? This study addresses this issue by measuring and comparing the visibility of six major, MeSH-indexed health catalogs through four different search engines (AltaVista, Google, Lycos, Northern Light) in two languages (English and French). Over half a million queries were sent to the search engines; for most of these search engines, according to our measures at the time the queries were sent, the most visible catalog for English MeSH terms was CliniWeb and the most visible one for French MeSH terms was CISMeF.

  9. Visible continuum pulses based on enhanced dispersive wave generation for endogenous fluorescence imaging.

    Science.gov (United States)

    Cui, Quan; Chen, Zhongyun; Liu, Qian; Zhang, Zhihong; Luo, Qingming; Fu, Ling

    2017-09-01

    In this study, we demonstrate endogenous fluorescence imaging using visible continuum pulses based on 100-fs Ti:sapphire oscillator and a nonlinear photonic crystal fiber. Broadband (500-700 nm) and high-power (150 mW) continuum pulses are generated through enhanced dispersive wave generation by pumping femtosecond pulses at the anomalous dispersion region near zero-dispersion wavelength of high-nonlinear photonic crystal fibers. We also minimize the continuum pulse width by determining the proper fiber length. The visible-wavelength two-photon microscopy produces NADH and tryptophan images of mice tissues simultaneously. Our 500-700 nm continuum pulses support extending nonlinear microscopy to visible wavelength range that is inaccessible to 100-fs Ti:sapphire oscillators and other applications requiring visible laser pulses.

  10. Policing Visible Sexual/Gender Diversity as a Program of Governance

    Directory of Open Access Journals (Sweden)

    Angela Dwyer

    2012-11-01

    Full Text Available Using interview data on LGBT young people’s policing experiences, I argue policing and security works as a program of government (Dean 1999; Foucault 1991; Rose 1999 that constrains the visibilities of diverse sexuality and gender in public spaces. While young people narrated police actions as discriminatory, the interactions were complex and multi-faceted with police and security working to subtly constrain the public visibilities of ‘queerness’. Same sex affection, for instance, was visibly yet unverifiably (Mason 2002 regulated by police as a method of governing the boundaries of proper gender and sexuality in public. The paper concludes by noting how the visibility of police interactions with LGBT young people demonstrates to the public that public spaces are, and should remain, heterosexual spaces.

  11. Making Information Visible, Accessible, and Understandable: Meta-Data and Registries

    National Research Council Canada - National Science Library

    Robinson, Clay

    2007-01-01

    ... the interoperability, discovery, and utility of data assets throughout the Department of Defense (DoD). Proper use and understanding of metadata can substantially enhance the utility of data by making it more visible, accessible, and understandable...

  12. Robust Visible and Infrared Light Emitting Devices Using Rare-Earth-Doped GaN

    National Research Council Canada - National Science Library

    Steckl, Andrew

    2006-01-01

    Rare earth (RE) dopants (such as Er, Eu, Tm) in the wide bandgap semiconductor (WBGS) GaN are investigated for the fabrication of robust visible and infrared light emitting devices at a variety of wavelengths...

  13. Thermal-to-visible transducer (TVT) for thermal-IR imaging

    Science.gov (United States)

    Flusberg, Allen; Swartz, Stephen; Huff, Michael; Gross, Steven

    2008-04-01

    We have been developing a novel thermal-to-visible transducer (TVT), an uncooled thermal-IR imager that is based on a Fabry-Perot Interferometer (FPI). The FPI-based IR imager can convert a thermal-IR image to a video electronic image. IR radiation that is emitted by an object in the scene is imaged onto an IR-absorbing material that is located within an FPI. Temperature variations generated by the spatial variations in the IR image intensity cause variations in optical thickness, modulating the reflectivity seen by a probe laser beam. The reflected probe is imaged onto a visible array, producing a visible image of the IR scene. This technology can provide low-cost IR cameras with excellent sensitivity, low power consumption, and the potential for self-registered fusion of thermal-IR and visible images. We will describe characteristics of requisite pixelated arrays that we have fabricated.

  14. Atmospheric aerosol load morphological classification and retrieved visibility based on lidar backscatter measurements

    CSIR Research Space (South Africa)

    Tesfaye, M

    2010-01-01

    Full Text Available In this paper, the tropospheric aerosol load morphological classification and its impact on temporal variation of visibility are investigated using a continuous 23-hour single channel CSIR-NLC mobile LIDAR backscatter measurement. The trajectory...

  15. Implementation of a Cost-Accounting System for Visibility of Weapon Systems Life-Cycle Costs

    National Research Council Canada - National Science Library

    Ugone, Mary

    2001-01-01

    .... The DoD Acquisition Reform Goal 10 required DoD to define requirements and establish an implementation plan for a cost-accounting system that provides routine visibility into weapon system life-cycle...

  16. The visibility of QSEN competencies in clinical assessment tools in Swedish nurse education.

    Science.gov (United States)

    Nygårdh, Annette; Sherwood, Gwen; Sandberg, Therese; Rehn, Jeanette; Knutsson, Susanne

    2017-12-01

    Prospective nurses need specific and sufficient knowledge to be able to provide quality care. The Swedish Society of Nursing has emphasized the importance of the six quality and safety competencies (QSEN), originated in the US, in Swedish nursing education. To investigate the visibility of the QSEN competencies in the assessment tools used in clinical practice METHOD: A quantitative descriptive method was used to analyze assessment tools from 23 universities. Teamwork and collaboration was the most visible competency. Patient-centered care was visible to a large degree but was not referred to by name. Informatics was the least visible, a notable concern since all nurses should be competent in informatics to provide quality and safety in care. These results provide guidance as academic and clinical programs around the world implement assessment of how well nurses have developed these essential quality and safety competencies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. The visibility of scientific misconduct: A review of the literature on retracted journal articles.

    Science.gov (United States)

    Hesselmann, Felicitas; Graf, Verena; Schmidt, Marion; Reinhart, Martin

    2017-10-01

    Retractions of scientific articles are becoming the most relevant institution for making sense of scientific misconduct. An increasing number of retracted articles, mainly attributed to misconduct, is currently providing a new empirical basis for research about scientific misconduct. This article reviews the relevant research literature from an interdisciplinary context. Furthermore, the results from these studies are contextualized sociologically by asking how scientific misconduct is made visible through retractions. This study treats retractions as an emerging institution that renders scientific misconduct visible, thus, following up on the sociology of deviance and its focus on visibility. The article shows that retractions, by highlighting individual cases of misconduct and general policies for preventing misconduct while obscuring the actors and processes through which retractions are effected, produce highly fragmented patterns of visibility. These patterns resemble the bifurcation in current justice systems.

  18. Prevalence of Visible and Occult Blood on the Surfaces of Fiberoptic Bronchoscopes

    National Research Council Canada - National Science Library

    McKamey, Jeffrey

    2000-01-01

    .... This study was conducted to determine if current cleaning, disinfection and sterilization procedures used at one medical center was adequate to remove visible and occult blood from fiberoptic bronchoscopes...

  19. Resource Allocation for Outdoor Visible Light Communications with Energy Harvesting Capabilities

    KAUST Repository

    Abdelhady, Amr Mohamed Abdelaziz; Amin, Osama; Chaaban, Anas; Alouini, Mohamed-Slim

    2018-01-01

    Visible light communication (VLC) is a promising technology that can support high data rate services for outdoor mass gathering night events while permitting energy harvesting. In this paper, a VLC system is considered where a transmitter sends data

  20. Psychological aspects of patients with breast cancer depending on the presence of visible postoperative defect

    Directory of Open Access Journals (Sweden)

    A. D. Zikiryakhodzhaev

    2015-01-01

    Full Text Available Objective. The study of coping behavior of patients with breast cancer (I, II stages in the postoperative period with «externally visible postoperative defect".Materials and methods. We studied the psychological characteristics of 35 patients with breast cancer (I, II stage, who underwent radical mastectomy, women were characterized in the postoperative period as "externally visible postoperative defect" ("e.v.p.d.", 35 patients with breast cancer (I, II stage who underwent ablative and reconstructive plastic surgery, women were characterized in the postoperative period as "without an externally visible postoperative defect" ("without an e.v.p.d.".The results and conclusions. The results of the study of women in both groups indicate that the patients are moderately using coping strategies for coping with the disease, preferring the strategy of "problem resolution" and "search of social support". Patients with breast cancer "with externally visible postoperative defect in comparing with patients with breast cancer "without an externally visible postoperative defect" often use positive religious coping in coping with the disease. The group of women with «externally visible postoperative defect" usually operate with negative religious coping. Both groups of women focused on the perception of social support. In a greater degree of social support they perceive from family and significant for them. Women with breast cancer and "externally visible postoperative defect” compared with women “without an externally visible postoperative defect" are not satisfied with your opportunities, have a feeling of weakness, doubt ability to evoke respect, sympathy, understanding and approval from others. They seek to change, doubt their self-worth, willing to put themselves in the guilt of their mistakes, failures, have low self-esteem. The group of patients with breast cancer "with externally visible postoperative defect" has an external locus of control

  1. MR-visible water content in human brain: a proton MRS study

    DEFF Research Database (Denmark)

    Christiansen, P; Toft, P B; Gideon, P

    1994-01-01

    . The major drawbacks are the necessity to make the assumptions that the water concentrations in the brain and that all tissue water is MR-visible. A number of in vivo measurements were carried out to estimate the concentration of MR-visible water in the brain of healthy volunteers divided into four age...... and biochemical data published, suggest that only a small fraction (invisible.(ABSTRACT TRUNCATED AT 250 WORDS)...

  2. Study on the identifying of meat's visible spectrum based on BP artificial neural network

    Science.gov (United States)

    Li, Xiaotian; Zhang, Tieqiang; Li, Bo; Jiang, Yongheng; Liu, Binghui; Li, Zhaokai

    2006-01-01

    A method to identify different meat by the visible and reflected spectra of meat with BP artificial neural net (BP-ANN) was introduced in this paper. The visible and reflected spectra (from 420 to 535nm) of different meat (beef and pork) were measured with fiber sensor spectrometer. A kind of ANN with a double-hidden layer was created to identify the different meat automatically. Its right ratio reaches 92.71%.

  3. Eosin Y Catalyzed Visible-Light-Promoted Aerobic Oxidative Cyclization of 2-Aminobenzothiazole

    Directory of Open Access Journals (Sweden)

    Vishal Srivastava

    2015-12-01

    Full Text Available A mild and efficient one-pot visible light irradiated synthesis of 2-aminobenzothiazole 4(a–l from arylisothiocyanate 1(a–l and secondary amines 2 have been reported in presence of eosin Y as an organophotoredox catalyst at room temperature under aerobic condition. This synthesis includes application of air and visible light as inexpensive, readily available, high atom economy, non-toxic and sustainable regents.

  4. Multi-fragment visibility determination in the context of order-independent transparency rendering

    OpenAIRE

    Marilena Maule

    2015-01-01

    Multi-fragment effects, in the computer-generated imagery context, are effects that determine pixel color based on information computed from more than one fragment. In such effects, the contribution of each fragment is extracted from its visibility with respect to a point of view. Seen through a pixel’s point of view, the visibility of one fragment depends on its spatial relationship with other fragments. This relationship can be reduced to the problem of sorting multiple fragments. Therefore...

  5. Radiographic evaluation of the course and visibility of the mandibular canal

    International Nuclear Information System (INIS)

    Jung, Yun Hoa; Cho, Bong Hae

    2014-01-01

    This study was performed to investigate the course of the mandibular canal on panoramic radiography and the visibility of this canal on both panoramic radiography and cone-beam computed tomography (CBCT). The study consisted of panoramic radiographs and CBCT images from 262 patients. The course of the mandibular canal, as seen in panoramic radiographs, was classified into four types: linear, elliptical, spoon-shaped, and turning curves. The visibility of this canal from the first to the third molar region was evaluated by visually determining whether the mandibular canal was clearly visible, probably visible, or invisible. The visibility of the canal on panoramic radiographs was compared with that on CBCT images. Elliptical curves were most frequently observed along the course of the mandibular canal. The percentage of clearly visible mandibular canals was the highest among the spoon-shaped curves and the lowest among the linear curves. On panoramic radiographs, invisible mandibular canals were found in 22.7% of the examined sites in the first molar region, 11.8% in the second molar region, and 1.3% in the third molar region. On CBCT cross-sectional images, the mandibular canal was invisible in 8.2% of the examined sites in the first molar region, 5.7% in the second molar region, and 0.2% in the third molar region. The visibility of this canal was lower in the first molar region than in the third molar region. The mandibular canal presented better visibility on CBCT images than on panoramic radiographs.

  6. The role of global data identification standards for supply chain visibility: the case of GS1

    OpenAIRE

    Semianiaka, Natallia; Silina, Ekaterina

    2012-01-01

    Purpose. Supply chain visibility is among the top concerns expressed by many supply chain leaders. While the traditional enablers of supply chain visibility are information sharing, IT implementation, and relationships between supply chain partners; the role of global supply chain standards as an integral part of each of these enablers is often underestimated. The purpose of this thesis is to investigate the adoption and applicability of global supply chain standards within the provisions of ...

  7. Phosphene-guided transcranial magnetic stimulation of occipital but not parietal cortex suppresses stimulus visibility

    Science.gov (United States)

    Tapia, Evelina; Mazzi, Chiara; Savazzi, Silvia; Beck, Diane M.

    2014-01-01

    Transcranial magnetic stimulation (TMS) applied over the occipital lobe approximately 100 ms after the onset of a stimulus decreases its visibility if it appears in the location of the phosphene. Because phosphenes can also be elicited by stimulation of the parietal regions, we asked if the same procedure that is used to reduce visibility of stimuli with occipital TMS will lead to decreased stimulus visibility when TMS is applied to parietal regions. TMS was randomly applied at 0 to 130 ms after the onset of the stimulus (SOA) in steps of 10 ms in occipital and parietal regions. Participants responded to the orientation of the line stimulus and rated its visibility. We replicate previous reports of phosphenes from both occipital and parietal TMS. As previously reported, we also observed visual suppression around the classical 100 ms window both in the objective line orientation and subjective visibility responses with occipital TMS. Parietal stimulation, on the other hand, did not consistently reduce stimulus visibility in any time window. PMID:24584900

  8. Transition metal-modified zinc oxides for UV and visible light photocatalysis.

    Science.gov (United States)

    Bloh, J Z; Dillert, R; Bahnemann, D W

    2012-11-01

    In order to use photocatalysis with solar light, finding more active and especially visible light active photocatalysts is a very important challenge. Also, studies of these photocatalysts should employ a standardized test procedure so that their results can be accurately compared and evaluated with one another. A systematic study of transition metal-modified zinc oxide was conducted to determine whether they are suitable as visible light photocatalysts. The photocatalytic activity of ZnO modified with eight different transition metals (Cu, Co, Fe, Mn, Ni, Ru, Ti, Zr) in three different concentrations (0.01, 0.1, and 1 at.%) was investigated under irradiation with UV as well as with visible light. The employed activity test is the gas-phase degradation of acetaldehyde as described by the ISO standard 22197-2. The results suggest that the UV activity can be improved with almost any modification element and that there exists an optimal modification ratio at about 0.1 at.%. Additionally, Mn- and Ru-modified ZnO display visible light activity. Especially the Ru-modified ZnO is highly active and surpasses the visible light activity of all studied titania standards. These findings suggest that modified zinc oxides may be a viable alternative to titanium dioxide-based catalysts for visible light photocatalysis. Eventually, possible underlying mechanisms are proposed and discussed.

  9. UV Blocking Glass: Low Cost Filters for Visible Light Photocatalytic Assessment

    Directory of Open Access Journals (Sweden)

    Charles W. Dunnill

    2014-01-01

    Full Text Available A number of commercially available art protection products have been compared and assessed for their suitability as UV blocking filters in the application of “visible light” photocatalytic research. Many groups claiming visible light photocatalytic success employ filters to block out stray UV radiation in order to justify that their photocatalysts are indeed visible light photocatalysts and not UV light photocatalysts. These filters come in varying degrees of ability and price and many authors fail to correctly characterise their filters in individual papers. The use of effective filters to prevent both false positive and false negative results is important to maintain scientific rigor and create accurate understanding of the subject. The optimum UV filter would have the highest UV blocking properties (<390 nm and simultaneously the highest visible light transmission (390–750 nm. Single and double layers of each of the glass products were assessed as well as laminate products. The conclusions show an inexpensive and highly effective setup for the conduction of visible light photochemistry that should be incorporated as a standard part in any researcher’s work where the claim of visible light activity is made.

  10. Highly Transparent, Visible-Light Photodetector Based on Oxide Semiconductors and Quantum Dots.

    Science.gov (United States)

    Shin, Seung Won; Lee, Kwang-Ho; Park, Jin-Seong; Kang, Seong Jun

    2015-09-09

    Highly transparent phototransistors that can detect visible light have been fabricated by combining indium-gallium-zinc oxide (IGZO) and quantum dots (QDs). A wide-band-gap IGZO film was used as a transparent semiconducting channel, while small-band-gap QDs were adopted to absorb and convert visible light to an electrical signal. Typical IGZO thin-film transistors (TFTs) did not show a photocurrent with illumination of visible light. However, IGZO TFTs decorated with QDs showed enhanced photocurrent upon exposure to visible light. The device showed a responsivity of 1.35×10(4) A/W and an external quantum efficiency of 2.59×10(4) under illumination by a 635 nm laser. The origin of the increased photocurrent in the visible light was the small band gap of the QDs combined with the transparent IGZO films. Therefore, transparent phototransistors based on IGZO and QDs were fabricated and characterized in detail. The result is relevant for the development of highly transparent photodetectors that can detect visible light.

  11. Visible-Light-Driven BiOI-Based Janus Micromotor in Pure Water.

    Science.gov (United States)

    Dong, Renfeng; Hu, Yan; Wu, Yefei; Gao, Wei; Ren, Biye; Wang, Qinglong; Cai, Yuepeng

    2017-02-08

    Light-driven synthetic micro-/nanomotors have attracted considerable attention due to their potential applications and unique performances such as remote motion control and adjustable velocity. Utilizing harmless and renewable visible light to supply energy for micro-/nanomotors in water represents a great challenge. In view of the outstanding photocatalytic performance of bismuth oxyiodide (BiOI), visible-light-driven BiOI-based Janus micromotors have been developed, which can be activated by a broad spectrum of light, including blue and green light. Such BiOI-based Janus micromotors can be propelled by photocatalytic reactions in pure water under environmentally friendly visible light without the addition of any other chemical fuels. The remote control of photocatalytic propulsion by modulating the power of visible light is characterized by velocity and mean-square displacement analysis of optical video recordings. In addition, the self-electrophoresis mechanism has been confirmed for such visible-light-driven BiOI-based Janus micromotors by demonstrating the effects of various coated layers (e.g., Al 2 O 3 , Pt, and Au) on the velocity of motors. The successful demonstration of visible-light-driven Janus micromotors holds a great promise for future biomedical and environmental applications.

  12. Visibility of trabecular meshwork by standard and polarization-sensitive optical coherence tomography

    Science.gov (United States)

    Yasuno, Yoshiaki; Yamanari, Masahiro; Kawana, Keisuke; Miura, Masahiro; Fukuda, Shinichi; Makita, Shuichi; Sakai, Shingo; Oshika, Tetsuro

    2010-11-01

    Polarization-sensitive optical coherence tomography (PS-OCT) is known to be advantageous because of its additional tissue-specific contrast of the anterior eye. So far, this advantage has been shown only qualitatively. We evaluate the improved visibility afforded by 3-D PS corneal and anterior eye segment OCT (PS-CAS-OCT) in visualizing the trabecular meshwork (TM) based on statistical evidences. A total of 31 normal subjects participated in this study. The anterior eye segments of both the eyes of the subjects are scanned using a custom-made PS-CAS-OCT and the standard-scattering OCT (S-OCT) and polarization-sensitive phase-retardation OCT (P-OCT) images are obtained. Three graders grade the visibility of the TM using a four-leveled grading system. The intergrader agreement, intermodality differences, and interquadrant dependence of visibility are statistically examined. All three of three combinations of graders show substantial agreement in visibility with P-OCT (ρ = 0.74, 0.70, and 0.68, Spearman's correlation), while only one of three shows substantial agreement with S-OCT (ρ = 0.72). Significant dependence of the visibility on the modality (S-OCT versus P-OCT) and quadrants are found by the analysis of variance. A subsequent Wilcoxon signed-rank test reveals significantly improved visibility. PS-CAS-OCT may become a useful tool for screening angle-closure glaucoma.

  13. Efficient Prediction of Low-Visibility Events at Airports Using Machine-Learning Regression

    Science.gov (United States)

    Cornejo-Bueno, L.; Casanova-Mateo, C.; Sanz-Justo, J.; Cerro-Prada, E.; Salcedo-Sanz, S.

    2017-11-01

    We address the prediction of low-visibility events at airports using machine-learning regression. The proposed model successfully forecasts low-visibility events in terms of the runway visual range at the airport, with the use of support-vector regression, neural networks (multi-layer perceptrons and extreme-learning machines) and Gaussian-process algorithms. We assess the performance of these algorithms based on real data collected at the Valladolid airport, Spain. We also propose a study of the atmospheric variables measured at a nearby tower related to low-visibility atmospheric conditions, since they are considered as the inputs of the different regressors. A pre-processing procedure of these input variables with wavelet transforms is also described. The results show that the proposed machine-learning algorithms are able to predict low-visibility events well. The Gaussian process is the best algorithm among those analyzed, obtaining over 98% of the correct classification rate in low-visibility events when the runway visual range is {>}1000 m, and about 80% under this threshold. The performance of all the machine-learning algorithms tested is clearly affected in extreme low-visibility conditions ({algorithm performance in daytime and nighttime conditions, and for different prediction time horizons.

  14. Synthesis and polymorphic control for visible light active titania nanoparticles

    Science.gov (United States)

    Kaewgun, Sujaree

    Titania (TiO2) is useful for many applications in photocatalysis, antimicrobials, pigment, deodorization, and decomposition of harmful organics and undesirable compounds in the air and waste water under UV irradiation. Among the three phases of TiO2, Rutile, Anatase, and Brookite, studies have been more focused on the anatase and rutile phases. Pure brookite is the most difficult phase to prepare, even under hydrothermal conditions. Predominantly brookite phase TiO2 nanoparticles were prepared by the Water-based Ambient Condition Sol (WACS) process in our laboratory. The objectives of this research were to enhance visible light active (VLA) photocatalytic properties of polymorphic brookite TiO2 by minimizing the lattice defects and narrowing band gap of titania by nitrogen and/or carbon chromophone, and to investigate the deactivation, reusability, and regeneration of the VLA titania in order to design better titania catalysts for organic compound degradation applications. In order to study the influence of hydroxyl content on photocatalytic activities (PCAs) of polymorphic titania nanoparticles, the WACS samples were post-treated by a Solvent-based Ambient Condition Sol (SACS) process in sec-butanol (sec-BuOH). All samples were characterized for phase composition, surface area, hydroxyl contamination, and particle morphology by x-ray diffraction, N2 physisorption, FT-IR, solid state 1H NMR and scanning electron microscopy, and then compared to a commercial titania, Degussa P25. Evaluation of methyl orange (MO) degradation under UV irradiation results showed that the lower lattice hydroxyl content in SACS titania enhanced the PCA. As-prepared titania and SACS samples, which have similar surface areas and crystallinity, were compared in order to prove that the superior PCA came from the reduction in the lattice hydroxyl content. To enhance PCA and VLA properties of WACS, an alternative high boiling point polar solvent, N-methylpyrrolidone (NMP), was utilized in the

  15. Seeing Is Believing: on the Visibility of Late Capitalism

    Directory of Open Access Journals (Sweden)

    Gordan Maslov

    2015-12-01

    capitalist reality which in appearance is neither true nor false but rather ‘objective illusion’. And yet concepts that aim to grasp this eluding totality – including the very term ‘capitalism’ – can rarely be found in Capital. This leads Jameson to conclude that Marx, after a well-documented laborious reworking of the opening chapters and the overall structure of Capital, found out that the accumulation of capital can be made visible only in its symptoms, distortions, crisis, and different cuts of structure. This return to the now famous Slavoj Žižek proposition that “Marx invented the symptom” (Žižek 1 is followed up with an even more far-reaching conclusion: the only possible Marxian totality of capitalism has a Freudian structure and is a result of a combination of different but ultimately partial representations unable to fully capture its field of phenomena. Jameson himself is unwilling to follow up the full implication of this parallel; insofar as Marxian capitalist totality can only be an aesthetic construct – or, to use psychoanalytic vocabulary, a ‘compromise formation’ – built for strategic purposes, it remains just one amongst other totalities, competing with them in a terrain not overdetermined by any recourse to economic objectivity. In order to avoid this, Jameson takes the road of Marx’s dialectic which for him resolves the duality of objectivism – economic determinism – and voluntarism underlying the whole history of Marxist theory. In actualizing Marx’s dialectics, Jameson is not returning to the mystic source itself as much as reading Marx via and alongside the likes of Althusser or Deleuze and other “unwilling” dialecticians he recruits along the way. At the same time, once more taking a jab at structuralist theory – claiming, for example, that one can mistake the structuralist notion of the synchronic for ‘conceptual ideology’ relating to the eternal present of capitalist accumulation – for Jame

  16. The System of the Calibration for Visibility Measurement Instrument Under the Atmospheric Aerosol Simulation Environment

    Directory of Open Access Journals (Sweden)

    Shu Zhifeng

    2016-01-01

    Full Text Available Visibility is one of the most important parameters for meteorological observation and numerical weather prediction (NWP.It is also an important factor in everyday life, mainly for surface and air traffic especially in the Aeronautical Meteorology. The visibility decides the taking off and landing of aircraft. If the airport visibility is lower than requirement for aircraft taking off stipulated by International Civil Aviation Administration, then the aircraft must be parked at the airport. So the accurate measurement of visibility is very important. Nowadays, many devices can be measured the visibility or meteorological optical range (MOR such as Scatterometers, Transmissometers and visibility lidar. But there is not effective way to verify the accuracy of these devices expect the artificial visual method. We have developed a visibility testing system that can be calibration and verification these devices. The system consists of laser transmitter, optical chopper, phase-locking amplifier, the moving optic receiving system, signal detection and data acquisition system, atmospheric aerosol simulation chamber. All of them were placed in the atmosphere aerosol simulation chamber with uniform aerosol concentration. The Continuous wave laser, wavelength 550nm, has been transmitted into the collimation system then the laser beam expanded into 40mm diameter for compressing the laser divergence angle before modulated by optical chopper. The expanding beam transmitting in the atmosphere aerosol cabin received by the optic receiving system moving in the 50m length precision guide with 100mm optical aperture. The data of laser signal has been acquired by phase-locking amplifier every 5 meter range. So the 10 data points can be detected in the 50 meters guide once. The slope of the fitting curve can be obtained by linear fitting these data using the least square method. The laser extinction coefficient was calculated from the slope using the Koschmieder

  17. Recommended metric for tracking visibility progress in the Regional Haze Rule.

    Science.gov (United States)

    Gantt, Brett; Beaver, Melinda; Timin, Brian; Lorang, Phil

    2018-05-01

    For many national parks and wilderness areas with special air quality protections (Class I areas) in the western United States (U.S.), wildfire smoke and dust events can have a large impact on visibility. The U.S. Environmental Protection Agency's (EPA) 1999 Regional Haze Rule used the 20% haziest days to track visibility changes over time even if they are dominated by smoke or dust. Visibility on the 20% haziest days has remained constant or degraded over the last 16 yr at some Class I areas despite widespread emission reductions from anthropogenic sources. To better track visibility changes specifically associated with anthropogenic pollution sources rather than natural sources, the EPA has revised the Regional Haze Rule to track visibility on the 20% most anthropogenically impaired (hereafter, most impaired) days rather than the haziest days. To support the implementation of this revised requirement, the EPA has proposed (but not finalized) a recommended metric for characterizing the anthropogenic and natural portions of the daily extinction budget at each site. This metric selects the 20% most impaired days based on these portions using a "delta deciview" approach to quantify the deciview scale impact of anthropogenic light extinction. Using this metric, sulfate and nitrate make up the majority of the anthropogenic extinction in 2015 on these days, with natural extinction largely made up of organic carbon mass in the eastern U.S. and a combination of organic carbon mass, dust components, and sea salt in the western U.S. For sites in the western U.S., the seasonality of days selected as the 20% most impaired is different than the seasonality of the 20% haziest days, with many more winter and spring days selected. Applying this new metric to the 2000-2015 period across sites representing Class I areas results in substantial changes in the calculated visibility trend for the northern Rockies and southwest U.S., but little change for the eastern U.S. Changing the

  18. Effects of meteorology and secondary particle formation on visibility during heavy haze events in Beijing, China.

    Science.gov (United States)

    Zhang, Qiang; Quan, Jiannong; Tie, Xuexi; Li, Xia; Liu, Quan; Gao, Yang; Zhao, Delong

    2015-01-01

    The causes of haze formation in Beijing, China were analyzed based on a comprehensive measurement, including PBL (planetary boundary layer), aerosol composition and concentrations, and several important meteorological parameters such as visibility, RH (relative humidity), and wind speed/direction. The measurement was conducted in an urban location from Nov. 16, 2012 to Jan. 15, 2013. During the period, the visibility varied from >20 km to less than a kilometer, with a minimum visibility of 667 m, causing 16 haze occurrences. During the haze occurrences, the wind speeds were less than 1m/s, and the concentrations of PM2.5 (particle matter with radius less than 2.5 μm) were often exceeded 200 μg/m(3). The correlation between PM2.5 concentration and visibility under different RH values shows that visibility was exponentially decreased with the increase of PM2.5 concentrations when RH was less than 80%. However, when RH was higher than 80%, the relationship was no longer to follow the exponentially decreasing trend, and the visibility maintained in very low values, even with low PM2.5 concentrations. Under this condition, the hygroscopic growth of particles played important roles, and a large amount of water vapor acted as particle matter (PM) for the reduction of visibility. The variations of meteorological parameters (RH, PBL heights, and WS (wind speed)), chemical species in gas-phase (CO, O3, SO2, and NOx), and gas-phase to particle-phase conversions under different visibility ranges were analyzed. The results show that from high visibility (>20 km) to low visibility (<2 km), the averaged PBL decreased from 1.24 km to 0.53 km; wind speeds reduced from 1m/s to 0.5m/s; and CO increased from 0.5 ppmv to 4.0 ppmv, suggesting that weaker transport/diffusion caused the haze occurrences. This study also found that the formation of SPM (secondary particle matter) was accelerated in the haze events. The conversions between SO2 and SO4 as well as NOx to NO3(-) increased

  19. Demoniškojo estetizmo pavidalai šiuolaikinėje Lietuvos kultūroje

    OpenAIRE

    Jekentaitė, Leonarda

    2003-01-01

    One of the most significant trends in postmodern Lithuanian art (the painter Š. Sauka, the writers S. Parulskis, S. Geda, A. Andriuškevičius, G. Radvilavičiūtė, G. Beresnevičius, the theatre director O. Koršunovas) can be characterised using Kierkegaardian terminology as demonic aestheticism. The essence of this phenomenon are: narcissism, existential irony and "debauched" self-will, always challenging and destroying all limits and taboos. The origin of their always extremely strong expressio...

  20. Electric equipment for Koto Refuse Incineration Plant; Tokyoto Koto seiso kojo muke denki setsubi

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-10

    Meidensha Corporation, intending to enter into refuse disposal business, delivered electric equipment to a Koto Refuse Incineration Plant, Koto Ward, Tokyo, and the facilities came into operation in October, 1998. The plant is the largest in Japan in terms of refuse processing capacity (1800t/day), and efforts are exerted to harmonize the plant with the surroundings, which involve pollution measures and a building that images a cruising yacht. The power receiving facility consists of a 66kV nominal two-circuit gas insulated switch and gas insulated transformer arranged in a space saving design. Heat from refuse incineration is fed to a steam turbine generator (yielding 50MW, the largest in Japan, with the surplus offered for sale after 15MW fed to loads in the site) and to neighboring facilities. For the suppression of fluctuations in voltage at the power receiving point, reactive power is subjected to control which is done by controlling the generator magnetic field system. An 11kV distribution system is provided to match the steam turbine generator voltage, and the voltage is stepped down to 6.6kV with the intermediary of a 23MVA gas insulated transformer. The power is fed to high voltage motors such as the one used for the induced draft fan, electric equipment in the buildings, power facilities in the plant, etc. A power monitoring board is provided in the central control room for general supervision over the power related facilities. (NEDO)