WorldWideScience

Sample records for design eye point

  1. Three-dimensional system integration for HUD placement on a new tactical airlift platform: design eye point vs. HUD eye box with accommodation and perceptual implications

    Science.gov (United States)

    Harbour, Steven D.; Hudson, Jeffery A.; Zehner, Gregory F.

    2012-06-01

    The retrofitting of a cockpit with a Head-Up-Display (HUD) raises potential accommodation and perceptual issues for pilots that must be addressed. For maximum optical efficiency, the goal is to be able to place every pilot's eye into the HUD Eye Motion Box (EMB) given a seat adjustment range. Initially, the Eye Reference Point (ERP) of the EMB should theoretically be located on the aircraft's original cockpit Design Eye Point (DEP), but human postures vary, and HUD systems may not be optimally placed. In reality, there is a distribution of pilot eyes around the DEP (which is dominant eye dependent); therefore, this must be accounted for in order to obtain appropriate visibility of all of the symbology based on photonic characteristics of the HUD. Pilot size and postural variation need to be taken into consideration when positioning the HUD system to ensure proper vision of all HUD symbology in addition to meeting the basic physical accommodation requirements of the cockpit. The innovative process and data collection methods for maximizing accommodation and pilot perception on a new "tactical airlift" platform are discussed as well as the related neurocognitive factors and the effects of information display design on cognitive phenomena.

  2. Head and eye movement as pointing modalities for eyewear computers

    DEFF Research Database (Denmark)

    Jalaliniya, Shahram; Mardanbeigi, Diako

    2014-01-01

    While the new generation of eyewear computers have increased expectations of a wearable computer, providing input to these devices is still challenging. Hand-held devices, voice commands, and hand gestures have already been explored to provide input to the wearable devices. In this paper, we examined using head and eye movements to point on a graphical user interface of a wearable computer. The performance of users in head and eye pointing has been compared with mouse pointing as a baseline method. The result of our experiment showed that the eye pointing is significantly faster than head or mouse pointing; however, our participants thought that the head pointing is more accurate and convenient.

  3. Eye tracking in user experience design

    CERN Document Server

    Romano Bergstorm, Jennifer

    2014-01-01

    Eye Tracking for User Experience Design explores the many applications of eye tracking to better understand how users view and interact with technology. Ten leading experts in eye tracking discuss how they have taken advantage of this new technology to understand, design, and evaluate user experience. Real-world stories are included from these experts who have used eye tracking during the design and development of products ranging from information websites to immersive games. They also explore recent advances in the technology which tracks how users interact with mobile devices, large-screen displays and video game consoles. Methods for combining eye tracking with other research techniques for a more holistic understanding of the user experience are discussed. This is an invaluable resource to those who want to learn how eye tracking can be used to better understand and design for their users. * Includes highly relevant examples and information for those who perform user research and design interactive experi...

  4. The Tehran Eye Study: research design and eye examination protocol

    Directory of Open Access Journals (Sweden)

    Fotouhi Akbar

    2003-07-01

    Full Text Available Abstract Background Visual impairment has a profound impact on society. The majority of visually impaired people live in developing countries, and since most disorders leading to visual impairment are preventable or curable, their control is a priority in these countries. Considering the complicated epidemiology of visual impairment and the wide variety of factors involved, region specific intervention strategies are required for every community. Therefore, providing appropriate data is one of the first steps in these communities, as it is in Iran. The objectives of this study are to describe the prevalence and causes of visual impairment in the population of Tehran city; the prevalence of refractive errors, lens opacity, ocular hypertension, and color blindness in this population, and also the familial aggregation of refractive errors, lens opacity, ocular hypertension, and color blindness within the study sample. Methods Design Through a population-based, cross-sectional study, a total of 5300 Tehran citizens will be selected from 160 clusters using a stratified cluster random sampling strategy. The eligible people will be enumerated through a door-to-door household survey in the selected clusters and will be invited. All participants will be transferred to a clinic for measurements of uncorrected, best corrected and presenting visual acuity; manifest, subjective and cycloplegic refraction; color vision test; Goldmann applanation tonometry; examination of the external eye, anterior segment, media, and fundus; and an interview about demographic characteristics and history of eye diseases, eye trauma, diabetes mellitus, high blood pressure, and ophthalmologic cares. The study design and eye examination protocol are described. Conclusion We expect that findings from the TES will show the status of visual problems and their causes in the community. This study can highlight the people who should be targeted by visual impairment prevention programs.

  5. Characterizing the point spread function of retinal OCT devices with a model eye-based phantom

    OpenAIRE

    Agrawal, Anant; Connors, Megan; Beylin, Alexander; Liang, Chia-pin; Barton, David; Chen, Yu; Drezek, Rebekah A.; Pfefer, T. Joshua

    2012-01-01

    We have designed, fabricated, and tested a nanoparticle-embedded phantom (NEP) incorporated into a model eye in order to characterize the point spread function (PSF) of retinal optical coherence tomography (OCT) devices in three dimensions under realistic imaging conditions. The NEP comprises a sparse distribution of highly backscattering silica-gold nanoshells embedded in a transparent UV-curing epoxy. The commercially-available model eye replicates the key optical structures and focusing po...

  6. ATSU Point Design (gasdynamics)

    International Nuclear Information System (INIS)

    In this presentation the basic principles outlined in the first talk ''Gas Cell Neutralizers'' will be applied to a problem of particular interest viz., the design of a ''gasdynamic free-jet'' neutralizer for the Los Alamos ATSU project. What will be presented here does not in any way represent the final gas neutralizer design for ATSU. Rather, the material presented herein should be viewed as simply a preliminary design intended to identify and gain insight into the more subtle issues that must be considered in designing this type of gas neutralizer

  7. Virtual egocenters as a function of display geometric field of view and eye station point

    Science.gov (United States)

    Psotka, Joseph

    1993-01-01

    The accurate location of one's virtual egocenter in a geometric space is of critical importance for immersion technologies. This experiment was conducted to investigate the role of field of view (FOV) and observer station points in the perception of the location of one's egocenter (the personal viewpoint) in virtual space. Rivalrous cues to the accurate location of one's egocenter may be one factor involved in simulator sickness. Fourteen subjects viewed an animated 3D model, of the room in which they sat, binocularly, from Eye Station Points (ESP) of either 300 or 800 millimeters. The display was on a 190 by 245 mm monitor, at a resolution of 320 by 200 pixels with 256 colors. They saw four models of the room designed with four geometric field of view (FOVg) conditions of 18, 48, 86, and 140 degrees. They drew the apparent paths of the camera in the room on a bitmap of the room as seen from infinity above. Large differences in the paths of the camera were seen as a function of both FOVg and ESP. Ten of the subjects were then asked to find the position for each display that minimized camera motion. The results fit well with predictions from an equation that took the ratio of human FOV (roughly 180 degrees) to FOVg times the Geometric Eye Point (GEP) of the imager: Zero Station Point = (180/FOVg)*GEP

  8. Turning points in reactor design

    Energy Technology Data Exchange (ETDEWEB)

    Beckjord, E.S.

    1995-09-01

    This article provides some historical aspects on nuclear reactor design, beginning with PWR development for Naval Propulsion and the first commercial application at Yankee Rowe. Five turning points in reactor design and some safety problems associated with them are reviewed: (1) stability of Dresden-1, (2) ECCS, (3) PRA, (4) TMI-2, and (5) advanced passive LWR designs. While the emphasis is on the thermal-hydraulic aspects, the discussion is also about reactor systems.

  9. Turning points in reactor design

    International Nuclear Information System (INIS)

    This article provides some historical aspects on nuclear reactor design, beginning with PWR development for Naval Propulsion and the first commercial application at Yankee Rowe. Five turning points in reactor design and some safety problems associated with them are reviewed: (1) stability of Dresden-1, (2) ECCS, (3) PRA, (4) TMI-2, and (5) advanced passive LWR designs. While the emphasis is on the thermal-hydraulic aspects, the discussion is also about reactor systems

  10. Dynamical Systems in Circuit Designer's Eyes

    Energy Technology Data Exchange (ETDEWEB)

    Odyniec, M.

    2011-05-09

    Examples of nonlinear circuit design are given. Focus of the design process is on theory and engineering methods (as opposed to numerical analysis). Modeling is related to measurements It is seen that the phase plane is still very useful with proper models Harmonic balance/describing function offers powerful insight (via the combination of simulation with circuit and ODE theory). Measurement and simulation capabilities increased, especially harmonics measurements (since sinusoids are easy to generate)

  11. Point detection and positioning system of the target based on surface cluster eyes

    Science.gov (United States)

    Guo, Fang; Zhang, Hao; Wang, Keyi

    2010-10-01

    The research of target detection and position is a challenge task in the fields where machine vision was used to develop various systems. However, monocular vision and binocular vision traditionally are difficult to meet the applications for high resolution and high sensitivity. Because compound eye imaging system is capacity of the large field of view for moving target detection with high sensitivity, the optical system has the potential to meet the applications above mentioned. In this paper, a preliminary exploration of the surface imaging system for the characteristics of cluster eyes was made and the optical signal processing methods of cluster eyes were introduced in detail. First the structure of the cluster eyes was described and the imaging channels of cluster eyes were ray traced with Zemax. Then based on the surface imaging mechanism with clusters eyes, the center of gravity of image space for target was extracted. Subsequently by the neural networks training based on LM (Levenberg-Marquardt) algorithm, the non-linear relationship between target and image was effectively calibrated. Finally, the corresponding relationship between target point and its image point among the various channels was established. The experimental results show that the multicast visual imaging systems are capable of providing the information of target azimuth and distance. Some attempts to study the systems were made to achieve high resolution, high sensitivity of target detection and positioning tasks. At the same time the surface imaging system also laid a solid foundation for the large compound eye imaging system from theory to practical application.

  12. Simulated-eye-design camera for high-contrast measurements

    Science.gov (United States)

    Kelley, Edward F.

    1999-04-01

    Light-measurement instrumentation based upon high-quality charge-coupled-devices is currently in use for measuring the characteristics of electronic displays. When such array detectors are used to measure scenes having high contrast or wide color variations, they can suffer from the effects of veiling glare or lens flare and thereby inaccurately measure the darker luminances because of a mixing of the scene luminances or colors. The simulated-dye-design camera attempts to reduce the effects of unwanted light contamination by copying some of the characteristics of the eye. This first prototype shows an improvement of a factor of 2.7 in its ability to measure high contrasts over a similar camera that is not filled with liquid.

  13. Noncontact detection of dry eye using a custom designed infrared thermal image system.

    Science.gov (United States)

    Su, Tai Yuan; Hwa, Chen Kerh; Liu, Po Hsuan; Wu, Ming Hong; Chang, David O; Su, Po Fang; Chang, Shu Wen; Chiang, Huihua Kenny

    2011-04-01

    Dry eye syndrome is a common irritating eye disease. Current clinical diagnostic methods are invasive and uncomfortable for patients. This study developed a custom designed noncontact infrared (IR) thermal image system to measure the spatial and temporal variation of the ocular surface temperature over a 6-second eye-open period. This research defined two parameters: the temperature difference value and the compactness value to represent the temperature change and the irregularity of the temperature distribution on the tear film. Using these two parameters, this study achieved discrimination results for the dry eye and the normal eye groups; the sensitivity is 0.84, the specificity is 0.83, and the receiver operating characteristic area is 0.87. The results suggest that the custom designed IR thermal image system may be used as an effective tool for noncontact detection of dry eye. PMID:21529078

  14. Design of Eye Movement Interactive Interface and Example Development

    OpenAIRE

    Kong Xiang-Zong; Fang Zhi-Gang; Xu Jie

    2013-01-01

    With the unceasing development of HCI (Human Computer Interaction) technology, natural interactive products are valued by more and more people. The next generation of man-machine interface may use touch, hearing or vision, etc. Among them, the visual sense is the most important channel to get information, but researches are mostly focused on the measurement of eye movement or data processing. In the future, the interaction of eyes with machines will have a very wide prospect. After concluding...

  15. Design of 3D eye-safe middle range vibrometer

    International Nuclear Information System (INIS)

    Laser Doppler Vibrometer and Range Meter (3D-MRV) is designed for middle range distances [1–100 meters]. 3D-MRV combines more than one laser in one device for a simultaneous real time measuring the distance and movement of the targets. The first laser has a short pulse (t?30psec) and low energy (E?200nJ) for distance measurement and the second one is a CW (continuous wave) single frequency laser for the velocity measurement with output power (P?30mW). Both lasers perform on the eye-safe wavelength 1.5 ?m. 3D-MRV uses the same mono-static optical transmitting and receiving channel for both lasers including an output telescope and a scanning angular system. 3D-MRV has an optical polarization switch to combine linear polarized laser beams from two lasers into one optical channel. The laser beams from both lasers by turns illuminate the target and the scattered laser radiation is collected by the telescope on a photo detector. The electrical signal from photo detector is used for measuring the distance to the target and its movement. For distance measurement the time of flight method is employed. For targets movement the optical heterodyne method is employed. The received CW laser radiation is mixed on a photo detector with the frequency-shifted laser radiation that is taken from CW laser and passed through an acousto-optic cell. The electrical signal from a photo detector on the difference frequency and phase has information about movement of the scattered targets. 3D-MVR may be used for the real time picturing of vibration of the extensive targets like bridges or aircrafts

  16. Design of the stereoscopic eye-tracking system for quantitative remote sensing applications

    Science.gov (United States)

    Sergeyev, Aleksandr; Levin, Eugene; Roggemann, Michael C.; Gienko, Gennady

    2008-08-01

    Spatial and temporal data derived from eye movements, compiled while the human eye observes geospatial imagery, retain meaningful and usable information. When human perceives the stereo effect, the virtual three dimensional (3D) model resulting from eye-brain interaction is generated in the mind. If the eye movements are recorded while the virtual model is observed, it is possible to reconstruct a 3D geometrical model almost identical to the one generated in the human brain. Information obtained from eye-movements can be utilized in many ways for remote sensing applications such as geospatial image analysis and interpretation. There are various eyetracking systems available on the market; however, none of them is designed to work with stereoscopic imagery. We explore different approaches and designs of the most suitable and non-intrusive scheme for stereoscopic image viewing in the eye-tracking systems to observe and analyze 3D visual models. The design of the proposed system is based on the optical separation method, which provides visually comfortable environment for perception of stereoscopic imagery. A proof of concept solution is based on multiple mirror-lens assembly that provides a significant reduction of geometrical constrains in eye-frame capturing. Two projected solutions: for wide-angle of viewing and helmet-integrated eye-tracker are also discussed here.

  17. Dynamics and mission design near libration points

    CERN Document Server

    Gómez, G; Simo, C; Masdemont, J

    2001-01-01

    This book studies several problems related to the analysis of planned or possible spacecraft missions. It is divided into four chapters. The first chapter is devoted to the computation of quasiperiodic solutions for the motion of a spacecraft near the equilateral points of the Earth-Moon system. The second chapter gives a complete description of the orbits near the collinear point, L 1 , between the Earth and the Sun in the restricted three-body problem (RTBP) model. In the third chapter, methods are developed to compute the nominal orbit and to design and test the control strategy for the qua

  18. Design of chirped fly's eye uniformizer for ArF lithography illumination system

    Science.gov (United States)

    Xiao, Lei; Li, Yanqiu; Wei, Lidong

    2014-11-01

    Fly's eye uniformizer is the key part of ArF lithography illumination system, whose main function is to illuminate the reticle uniformly. Due to the periodic structure of regular fly's eye uniformizer and the high coherence of the ArF laser, the output intensity distribution is modulated with equidistant sharp intensity peaks (interference speckle pattern) which disturbed the uniformity on the reticle. In this paper, we design a chirped fly's eye uniformizer which consists of chirped fly's eye and a condenser for illumination system in ArF lithography system. The chirped fly's eye consists of individually shaped micro-lenses defined by a parametric description which can be derived completely from analytical functions. The micro-lenses with different thicknesses in the chirped fly's eye have a function of delaying the optical path which reducing the laser coherence and speckle pattern on the reticle. Detailed design process of the chirped fly's eye uniformizer for numerical aperture (NA) 0.75 lithography illumination system is presented. Light intensity distribution on reticle produced by regular and chirped fly's eye uniformizer are analyzed and compared by the method of wave optics, and the results show that chirped can restrain sharp intensity peaks efficiently. Furthermore, the chirped fly's eye uniformizer has been traced in LightTools software under conventional and annual illumination modes, and the non-uniformity of the non-scan and scan direction on the reticle reached 0.75% and 1.24% respectively. The simulation results show that the chirped fly's eye uniformizer can provide high illumination uniformity and reduce the speckle pattern efficiently without additional elements.

  19. Influence of the characteristics of tear film break-up on the point spread function of an eye model

    Science.gov (United States)

    Kasprzak, Henryk T.; Licznerski, Tomasz J.

    1999-07-01

    The paper presents the complex structure of the human tear film. From the optics point of view the homogeneously distributed tear film on the corneal surface makes this diffused surface optically smooth. Every eye blink distributes a new portion of tears on the surface of the cornea or the contact lens. If the production of tears is not sufficient or their composition is inappropriate, the tear film is deteriorated and so called tear film break-up (TFBU) appears on the surface of the cornea. These local break-ups of the smooth tear film introduce disturbances in the phase of a quasiplane wavefront falling on the cornea from a far-located point source of light. Two types of the TFBUs are considered in this paper. Topography of a point one and a linear one form of the break ups are approximated by use of four different continuous functions. The modeled topography of the TFBU is used for calculation of the local variation of the wavefront phase. The Point Spread Function of the eye model is calculated by use of the Fast Fourier Transform without and with the different approximations of TFBUs. It is shown that different type of TFBU approximation influences significantly the form of the Point Spread Function of the eye.

  20. High Pulse Repetition Rate, Eye Safe, Visible Wavelength Lidar Systems: Design, Results and Potential

    Science.gov (United States)

    Spinhirne, James; Berkoff, Timothy; Welton, Elsworth; Campbell, James; OCStarr, David (Technical Monitor)

    2002-01-01

    In 1993 the first of the eye safe visible wavelength lidar systems known now as Micro Pulse Lidar (MPL) became operational. Since that time there have been several dozen of these systems produced and applied for full time profiling of atmospheric cloud and aerosol structure. There is currently an observational network of MPL sites to support global climate research. In the course of application of these instruments there have been significant improvements in understanding, design and performance of the systems. There are addition potential and applications beyond current practice for the high repetition rate, eye safe designs. The MPL network and the current capability, design and future potential of MPL systems are described.

  1. Design of integrated eye tracker-display device for head mounted systems

    Science.gov (United States)

    David, Y.; Apter, B.; Thirer, N.; Baal-Zedaka, I.; Efron, U.

    2009-08-01

    We propose an Eye Tracker/Display system, based on a novel, dual function device termed ETD, which allows sharing the optical paths of the Eye tracker and the display and on-chip processing. The proposed ETD design is based on a CMOS chip combining a Liquid-Crystal-on-Silicon (LCoS) micro-display technology with near infrared (NIR) Active Pixel Sensor imager. The ET operation allows capturing the Near IR (NIR) light, back-reflected from the eye's retina. The retinal image is then used for the detection of the current direction of eye's gaze. The design of the eye tracking imager is based on the "deep p-well" pixel technology, providing low crosstalk while shielding the active pixel circuitry, which serves the imaging and the display drivers, from the photo charges generated in the substrate. The use of the ETD in the HMD Design enables a very compact design suitable for Smart Goggle applications. A preliminary optical, electronic and digital design of the goggle and its associated ETD chip and digital control, are presented.

  2. COMS eye plaque brachytherapy dosimetric sensitivity to source photon energy and seed design

    International Nuclear Information System (INIS)

    This study explores the influence of source photon energy on eye plaque brachytherapy dose distributions for a 16 mm COMS plaque filled with 103Pd, 125I, or 131Cs sources or monoenergetic photon emissions ranging from 12 keV to 100 keV. Dose distributions were similarly created for all permutations of three common brachytherapy seed designs. Within this range, sources with average energy ?22 keV may reduce dose to the opposite eye wall by more than a factor of 2 while maintaining tolerable proximal sclera doses when prescribing to depths of 9 mm or less. Current commercially-available brachytherapy sources can exhibit up to 15% relative dosimetric sensitivity to seed design at regions within the eye. - Highlights: • Episcleral eye plaque brachytherapy utilizes low-energy photon-emitting sources. • Dose distribution sensitivity to source photon energy and seed design was examined. • Tumor dose conformity and critical structure sparing from ?22 keV photons is preferred. • Ocular dose distributions varied by up to 15% with seed design permutations

  3. The Tromsø Eye Study : study design, methodology and results on visual acuity and refractive errors

    DEFF Research Database (Denmark)

    Bertelsen, Geir; Erke, Maja G

    2013-01-01

    Purpose:? To describe the study design and methodology of the Tromsø Eye Study (TES), and to describe visual acuity and refractive error in the study population. Methods:? The Tromsø Eye Study is a sub-study of the Tromsø Study, a population-based multipurpose longitudinal study in the municipality of Tromsø, Norway. The Tromsø Eye Study was a part of the sixth survey of the Tromsø Study, conducted from October 2007 through December 2008. The eye examination included information on self-reported eye diseases, assessment of visual acuity and refractive errors, retinal photography and optical coherence tomography. Retinal images were graded for diabetic retinopathy and age-related macular degeneration, and with computer-assisted measurements of arteriolar and venular diameters. In addition, TES researchers have access to the large comprehensive Tromsø Study database including physical examination results, carotid artery ultrasound, electrocardiogram, bone densitometry, cognitive tests, questionnaires, DNA, blood and urine samples and more from the present and the five previous surveys. Results:? Visual acuity was assessed in 6459 subjects and refraction in 6566 subjects aged 38-87?years. Snellen visual acuity

  4. Dynamics and mission design near libration points

    CERN Document Server

    Gómez, G; Llibre, J; Martínez, R

    2001-01-01

    It is well known that the restricted three-body problem has triangular equilibrium points. These points are linearly stable for values of the mass parameter, µ , below Routh's critical value, µ 1 . It is also known that in the spatial case they are nonlinearly stable, not for all the initial conditions in a neighborhood of the equilibrium points L 4 , L 5 but for a set of relatively large measures. This follows from the celebrated Kolmogorov-Arnold-Moser theorem. In fact there are neighborhoods of computable size for which one obtains "practical stability" in the sense that the massless partic

  5. Using Eye Movement to Control a Computer: A Design for a Lightweight Electro-Oculogram Electrode Array and Computer Interface

    OpenAIRE

    Ia?n?ez, Eduardo; Azorin, Jose M.; Perez-vidal, Carlos

    2013-01-01

    This paper describes a human-computer interface based on electro-oculography (EOG) that allows interaction with a computer using eye movement. The EOG registers the movement of the eye by measuring, through electrodes, the difference of potential between the cornea and the retina. A new pair of EOG glasses have been designed to improve the user's comfort and to remove the manual procedure of placing the EOG electrodes around the user's eye. The interface, which includes the EOG electrodes, us...

  6. Dynamics and mission design near libration points

    CERN Document Server

    Gómez, G; Simo, C; Martínez, R

    2001-01-01

    In this book the problem of station keeping is studied for orbits near libration points in the solar system. The main focus is on orbits near halo ones in the (Earth+Moon)-Sun system. Taking as starting point the restricted three-body problem, the motion in the full solar system is considered as a perturbation of this simplified model. All the study is done with enough generality to allow easy application to other primary-secondary systems as a simple extension of the analytical and numerical computations. Contents: Bibliographical Survey; Halo Orbits. Analytical and Numerical Study; The Neigh

  7. Dynamics and mission design near libration points

    CERN Document Server

    Gómez, G; Jorba, A; Masdemont, J

    2001-01-01

    The aim of this book is to explain, analyze and compute the kinds of motions that appear in an extended vicinity of the geometrically defined equilateral points of the Earth-Moon system, as a source of possible nominal orbits for future space missions. The methodology developed here is not specific to astrodynamics problems. The techniques are developed in such a way that they can be used to study problems that can be modeled by dynamical systems. Contents: Global Stability Zones Around the Triangular Libration Points; The Normal Form Around L 5 in the Three-dimensional RTBP; Normal Form of th

  8. The Fly's Eye Camera System -- an instrument design for large \\'etendue time-domain survey

    CERN Document Server

    Pál, András; Csépány, Gergely; Jaskó, Attila; Schlaffer, Ferenc; Vida, Krisztián; Mez?, György; Döbrentei, László; Farkas, Ern?; Kiss, Csaba; Oláh, Katalin; Regály, Zsolt

    2013-01-01

    In this paper we briefly summarize the design concepts of the Fly's Eye Camera System, a proposed high resolution all-sky monitoring device which intends to perform high cadence time domain astronomy in multiple optical passbands while still accomplish a high \\'etendue. Fundings have already been accepted by the Hungarian Academy of Sciences in order to design and build a Fly's Eye device unit. Beyond the technical details and the actual scientific goals, this paper also discusses the possibilities and yields of a network operation involving ~10 sites distributed geographically in a nearly homogeneous manner. Currently, we expect to finalize the mount assembly -- that performs the sidereal tracking during the exposures -- until the end of 2012 and to have a working prototype with a reduced number of individual cameras sometimes in the spring or summer of 2013.

  9. The Fly's Eye Camera System -- an instrument design for large \\'etendue time-domain survey

    CERN Document Server

    Csépány, Gergely; Vida, Krisztián; Regály, Zsolt; Mészáros, László; Oláh, Katalin; Kiss, Csaba; Döbrentei, László; Jaskó, Attila; Mez?, György; Farkas, Ern?

    2014-01-01

    In this paper we briefly summarize the design concepts of the Fly's Eye Camera System, a proposed high resolution all-sky monitoring device which intends to perform high cadence time domain astronomy in multiple optical passbands while still accomplish a high \\'etendue. Fundings have already been accepted by the Hungarian Academy of Sciences in order to design and build a Fly's Eye device unit. Beyond the technical details and the actual scientific goals, this paper also discusses the possibilities and yields of a network operation involving $\\sim10$ sites distributed geographically in a nearly homogeneous manner. Currently, we expect to finalize the mount assembly -- that performs the sidereal tracking during the exposures -- until the end of 2012 and to have a working prototype with a reduced number of individual cameras sometimes in the spring or summer of 2013.

  10. Customized schematic eye model for refraction correction design based on ocular wavefront and corneal topography measurements

    Science.gov (United States)

    Curatu, Eugene O.; Pettit, George H.; Campin, John A.

    2002-06-01

    The subject of this paper relates to the ocular optical design and vision analysis of refractive correction of the eye. After the purpose statement and the assumption list, the concept of the schematic eye matching a particular (measured) wavefront is introduced. This concept is based on the fact that the ocular wavefront, together with the corneal topography, can be seen as the mathematical global representation of the eye working in monochromatic light and having a foveal vision. The discussed design technique, including an iterative optimization method, could be applied in any ocular correction that utilizes cornea topography and/or ocular wavefront, e.g. contact lens or intra-corneal implant. However, the application this paper refers to is the ocular refractive correction by a procedure using the LADARVISION. It consists of surgical removal and subsequent replacement of a corneal flap on a stromal surface whose shape has been changed by laser ablation of the tissue. Subsequent sections of this paper are dedicated to establishing the limits of possible refractive correction, the influences of the flap and corneal topography into the refractive correction calculation. Finally a realistic evaluation of the results and a list of possible developments of this new optical design method are discussed.

  11. NIF Ignition Target 3D Point Design

    Energy Technology Data Exchange (ETDEWEB)

    Jones, O; Marinak, M; Milovich, J; Callahan, D

    2008-11-05

    We have developed an input file for running 3D NIF hohlraums that is optimized such that it can be run in 1-2 days on parallel computers. We have incorporated increasing levels of automation into the 3D input file: (1) Configuration controlled input files; (2) Common file for 2D and 3D, different types of capsules (symcap, etc.); and (3) Can obtain target dimensions, laser pulse, and diagnostics settings automatically from NIF Campaign Management Tool. Using 3D Hydra calculations to investigate different problems: (1) Intrinsic 3D asymmetry; (2) Tolerance to nonideal 3D effects (e.g. laser power balance, pointing errors); and (3) Synthetic diagnostics.

  12. NIF Ignition Target 3D Point Design

    International Nuclear Information System (INIS)

    We have developed an input file for running 3D NIF hohlraums that is optimized such that it can be run in 1-2 days on parallel computers. We have incorporated increasing levels of automation into the 3D input file: (1) Configuration controlled input files; (2) Common file for 2D and 3D, different types of capsules (symcap, etc.); and (3) Can obtain target dimensions, laser pulse, and diagnostics settings automatically from NIF Campaign Management Tool. Using 3D Hydra calculations to investigate different problems: (1) Intrinsic 3D asymmetry; (2) Tolerance to nonideal 3D effects (e.g. laser power balance, pointing errors); and (3) Synthetic diagnostics

  13. Design point selection for an ignited ITER

    International Nuclear Information System (INIS)

    The parameter choice for the ITER design is dominated by the need to achieve ignition. Different energy confinement time scalings extrapolate to different device parameters, and the final design chosen must have a reasonable chance of success under the presently favoured scalings. This study investigates the device performance over the plasma current - aspect ratio design space, using sets of simplified equations and more detailed parametric analysis codes, with a view to clarifying the acceptable parameter region. Alterations to the initial assumptions of plasma elongation, plasma safety factor and peak toroidal field, and the effect of limiting the wall load, are also investigated. The study concludes that a device with aspect ratio around 3 and plasma current about 20 MA would be an appropriate choice. Under the assumptions of the study such a device would have a major radius of about 5.8m and would require the attainment of enhancement factors around 1.5 over L-mode scaling. (author). 6 refs, 11 figs, 3 tabs

  14. ARIES-ST design point selection

    International Nuclear Information System (INIS)

    The spherical tokamak (ST) regime of low-aspect-ratio (LAR) tokamak operation has provided an opportunity to consider a 1000-MWe(net) D-T power plant conceptual design, designated ARIES-ST. Physics attributes include high beta (?50%) together with high bootstrap current contribution (?95%). Neutral-beam current drive (?28 MW) supports steady-state operation. The plasma aspect ratio was selected to be A?1.6 leading to the choice of major plasma toroidal radius, RT=3.2 m and plasma half-width, a=2.0 m. The usual engineering considerations of providing an efficient thermal power cycle (gross efficiency ?45%), while handling first-wall (?1 MW/m2) and divertor-plate (?5 MW/m2) surface heat fluxes, leads to 14-MeV neutron wall loads near 4.1 MW/m2 (average) and 5.6 MW/m2 (peak at outboard mid-plane) in a dual (PbLi and He) coolant system. The water-cooled toroidal-field-coil (TFC) centerpost is protected by a 20-cm (inboard) shield that does not breed tritium. Joule dissipation in the TFC system provides the major contribution to the plant recirculating power; specifically, Cu centerpost (222 MW), Al outboard shell (47 MW), Cu leads (27 MW), and power supplies (33 MW). The overall plant recirculating power fraction is an uncomfortable 34%. For a plant capacity factor ?76%, consistent with earlier ARIES studies, the COE is projected to be ?84 mill/kWe h (1992 constant $), using similar unit-cost assumptimilar unit-cost assumptions and some passive-safety cost credits. Inclusion of additional credits for advanced, low-unit-cost manufacturing based on plasma spray and related techniques (as applied to the TFC centerpost and outboard TFC shell only) lowers this COE estimate to ?79 mill/kWe h

  15. Frequency of secondary cataract development in pseudophakic eyes with posterior chamber IOL of current designs in case of axial myopia

    Directory of Open Access Journals (Sweden)

    G.V. Sorokoletov

    2013-02-01

    Full Text Available ABSTRACT Purpose. To evaluate a frequency of secondary cataract development in different periods of postoperative follow-up after cataract phacoemulsification depending on the degree of axial myopia and the implanted IOL design. Material and methods. A retrospective analysis of secondary cataract formation in the long-term follow-up after cataract phacoemulsification with foldable intraocular lens implantation was performed in 16575 eyes out of 8722 patients with emmetropia and axial myopia. The average age of patients was 74±7 years, and the follow-up period was 5 years. The eyes with associated pathology such as glaucoma, diabetic retinopathy etc, were excluded from the study. Depending on the design of implanted IOL all eyes were divided into 3 groups. The first group included 5527 eyes with the implanted B-lens IOL (Hanita, Israel. The second group included 5629 eyes with the implanted Idea IOL (XCELENS, Switzerland. The third group consisted of 5419 eyes with the implanted Acrysof natural, SA60AT IOL (Alcon, USA. In every case the degree of myopia was evaluated using axial length of an eye that was measured instrumentally. The incidence of secondary cataract formation was evaluated on quantity of YAG-laser posterior capsule dissection within the 5-year follow-up after phacoemulsification with IOL implantation. Conclusion. According to our results the incidence of PCO is directly dependent on the axial length of the eye, strongly increasing in eyes with high axial myopia. The design and material of implanted IOL played an important role in PCO formation too. The eyes with the Acrysof natural, SA60AT IOL (Alcon, USA had the lowest incidence of PCO in the long-term follow-up.

  16. Designing a Secure Point-of-Sale System

    DEFF Research Database (Denmark)

    Sharp, Robin; Pedersen, Allan

    2006-01-01

    This paper describes some experiences with using the ''Common Criteria for Information Security Evaluation'' as the basis for a design methodology when designing secure systems. As an example, the design process for a Point-of-Sale (POS) system is described.

  17. Designing a high accuracy 3D auto stereoscopic eye tracking display, using a common LCD monitor

    Science.gov (United States)

    Taherkhani, Reza; Kia, Mohammad

    2012-09-01

    This paper describes the design and building of a low cost and practical stereoscopic display that does not need to wear special glasses, and uses eye tracking to give a large degree of freedom to viewer (or viewer's) movement while displaying the minimum amount of information. The parallax barrier technique is employed to turn a LCD into an auto-stereoscopic display. The stereo image pair is screened on the usual liquid crystal display simultaneously but in different columns of pixels. Controlling of the display in red-green-blue sub pixels increases the accuracy of light projecting direction to less than 2 degrees without losing too much LCD's resolution and an eye-tracking system determines the correct angle to project the images along the viewer's eye pupils and an image processing system puts the 3D images data in correct R-G-B sub pixels. 1.6 degree of light direction controlling achieved in practice. The 3D monitor is just made by applying some simple optical materials on a usual LCD display with normal resolution. [Figure not available: see fulltext.

  18. Progress and prospects for an IFE relevant FI point design

    International Nuclear Information System (INIS)

    The physics issues involved in scaling from sub-ignition to high gain fast ignition are discussed. Successful point designs must collimate the electrons and minimise the standoff distance to avoid multi-megajoule ignition energies. Collimating B field configurations are identified and some initial designs are explored. (authors)

  19. Microsoft Office SharePoint Designer 2007 Step by Step

    CERN Document Server

    Coventry, Penelope

    2008-01-01

    The smart way to learn Office SharePoint Designer 2007-one step at a time! Work at your own pace through the easy numbered steps, practice files on CD, helpful hints, and troubleshooting tips to master the fundamentals of building customized SharePoint sites and applications. You'll learn how to work with Windows® SharePoint Services 3.0 and Office SharePoint Server 2007 to create Web pages complete with Cascading Style Sheets, Lists, Libraries, and customized Web parts. Then, make your site really work for you by adding data sources, including databases, XML data and Web services, and RSS fe

  20. Accuracy Constraint Determination in Fixed-Point System Design

    Directory of Open Access Journals (Sweden)

    Serizel R

    2008-01-01

    Full Text Available Most of digital signal processing applications are specified and designed with floatingpoint arithmetic but are finally implemented using fixed-point architectures. Thus, the design flow requires a floating-point to fixed-point conversion stage which optimizes the implementation cost under execution time and accuracy constraints. This accuracy constraint is linked to the application performances and the determination of this constraint is one of the key issues of the conversion process. In this paper, a method is proposed to determine the accuracy constraint from the application performance. The fixed-point system is modeled with an infinite precision version of the system and a single noise source located at the system output. Then, an iterative approach for optimizing the fixed-point specification under the application performance constraint is defined and detailed. Finally the efficiency of our approach is demonstrated by experiments on an MP3 encoder.

  1. Using eye movement to control a computer: a design for a lightweight electro-oculogram electrode array and computer interface.

    Science.gov (United States)

    Iáñez, Eduardo; Azorin, Jose M; Perez-Vidal, Carlos

    2013-01-01

    This paper describes a human-computer interface based on electro-oculography (EOG) that allows interaction with a computer using eye movement. The EOG registers the movement of the eye by measuring, through electrodes, the difference of potential between the cornea and the retina. A new pair of EOG glasses have been designed to improve the user's comfort and to remove the manual procedure of placing the EOG electrodes around the user's eye. The interface, which includes the EOG electrodes, uses a new processing algorithm that is able to detect the gaze direction and the blink of the eyes from the EOG signals. The system reliably enabled subjects to control the movement of a dot on a video screen. PMID:23843986

  2. Civil tiltrotor transport point design: Model 940A

    Science.gov (United States)

    Rogers, Charles; Reisdorfer, Dale

    1993-01-01

    The objective of this effort is to produce a vehicle layout for the civil tiltrotor wing and center fuselage in sufficient detail to obtain aerodynamic and inertia loads for determining member sizing. This report addresses the parametric configuration and loads definition for a 40 passenger civil tilt rotor transport. A preliminary (point) design is developed for the tiltrotor wing box and center fuselage. This summary report provides all design details used in the pre-design; provides adequate detail to allow a preliminary design finite element model to be developed; and contains guidelines for dynamic constraints.

  3. Generalizations of fuzzy linguistic control points in geometric design

    Science.gov (United States)

    Sallehuddin, M. H.; Wahab, A. F.; Gobithaasan, R. U.

    2014-07-01

    Control points are geometric primitives that play an important role in designing the geometry curve and surface. When these control points are blended with some basis functions, there are several geometric models such as Bezier, B-spline and NURBS(Non-Uniform Rational B-Spline) will be produced. If the control points are defined by the theory of fuzzy sets, then fuzzy geometric models are produced. But the fuzzy geometric models can only solve the problem of uncertainty complex. This paper proposes a new definition of fuzzy control points with linguistic terms. When the fuzzy control points with linguistic terms are blended with basis functions, then a fuzzy linguistic geometric model is produced. This paper ends with some numerical examples illustrating linguistic control attributes of fuzzy geometric models.

  4. Professional SharePoint 2010 Branding and User Interface Design

    CERN Document Server

    Drisgill, Randy; Sanford, Jacob J; Stubbs, Paul; Riemann, Larry

    2010-01-01

    A must have guide for creating engaging and usable SharePoint 2010 brandingWith SharePoint 2010, Microsoft has provided a more robust environment for creating collaboration and content management sites that rival any of the popular websites on the internet. Creating a branded SharePoint site involves understanding both traditional web design techniques as well as topics that are typically reserved for developers. This book bridges that gap by not only providing expert guidance for creating beautiful public facing and internal intranet sites but it also addresses the needs of those readers that

  5. Eye Safe, Visible Wavelength Lidar Systems: Design and Operational Advances, Results and Potential

    Science.gov (United States)

    Spinhirne, James; Welton, Ellsworth J.; Berkoff, Timothy; Campbell, James

    2007-01-01

    In the early nineties the first of the eye safe visible wavelength lidar systems known now as Micro Pulse Lidar (MPL) became operational. The important advance of the design was a system that, unlike most existing lidar, operated at eye safe energy densities and could thus operate unattended for full time monitoring. Since that time there have been many dozens of these systems produced and applied for full time profiling of atmospheric cloud and aerosol structure. There is currently an observational network of MPL sites to support global climate research. In thc course of application of these instruments there have been significant improvements in the, design and performance of the systems. In the last half decade particularly there has been significant application and technical development of MPL systems. In this paper we review progress. The current MPL systems in use are all single wavelength systems designed for cloud and aerosol applications. For the cloud and aerosol applications, both lidar depolarization and multi wavelength measurements have significant applications. These can be accomplished with the MPL, approach. The main current challenge for the lidar network activity are in the area of the reliability, repeatability and efficiency of data processing. The network makes use of internet data downloads and automated processing. The heights of all cloud and aerosol layers are needed. The recent emphasis has been in operationally deriving aerosol extinction cross section. Future emphasis will include adding cirrus optical parameters. For operational effectiveness, improvements to simplify routine data signal calibration are being researched. Overall the MPL systems have proven very effective. A large data base of results from globally distributed sites can be easily accessed through the internet. Applications have included atmospheric model development. Validation of current global satellite observations of aerosol and clouds, including now orbital lidar observations, was a primary goal for NASA. Although sampling issues require careful consideration, results have proven useful.

  6. Optimum design point for a closed-cycle OTEC system

    Energy Technology Data Exchange (ETDEWEB)

    Ikegami, Yasuyuki; Uehara, Haruo [Saga Univ. (Japan)

    1994-12-31

    Performance analysis is performed for optimum design point of a closed-cycle Ocean Thermal Energy Conversion (OTEC) system. Calculations are made for an OTEC model plant with a gross power of 100 MW, which was designed by the optimization method proposed by Uehara and Ikegami for the design conditions of 21 C--29 C warm sea water temperature and 4 C cold sea water temperature. Ammonia is used as working fluid. Plate type evaporator and condenser are used as heat exchangers. The length of the cold sea water pipe is 1,000 m. This model plant is a floating-type OTEC plant. The objective function of optimum design point is defined as the total heat transfer area of heat exchangers per the annual net power.

  7. An iodine-125 applicator designed for irradiating blood vessels growing into the cornea of the eye

    International Nuclear Information System (INIS)

    The invasion of the traumatized cornea by blood vessels is a well known complication is often associated with graft rejection. Graft acceptance may be improved by the induction of endarteritis with ? radiation but the corneal stroma may be so changed by the necessary dose of radiation (commonly 4500-5000 cGy in three or four fractions) as to significantly increase the risk of sloughing (Macfaul and Bedford, 1970). To overcome this problem, the authors have designed and made an 125I eye applicator to produce an extremely narrow radiation field for treating the vascularization at the base of the cornea only. The anterior part of the cornea receives a very small dose of about 11% of that given to the base and is sufficiently large to receive a 6mm corneal transplant. (author)

  8. Practical design for compact image scanner with large depth of field by compound eye system.

    Science.gov (United States)

    Kawano, Hiroyuki; Okamoto, Tatsuki; Nakajima, Hajime; Takushima, Shigeru; Toyoda, Yoshitaka; Yamanaka, Satoshi; Funakura, Tetsuo; Yamagata, Kosaku; Matsuzawa, Taku; Kunieda, Tatsuya; Minobe, Tadashi

    2014-07-28

    We designed a new image scanner using the reflective optics of a compound eye system that can easily assemble plural imaging optical units (called imaging cells) and is compact with a large depth of field (DOF). Our image scanner is constructed from 32 reflective imaging cells, each of which takes an image of approximately a 10-mm field of view (FOV) that slightly overlap the adjacent imaging cells. The total image is rebuilt by combining the 32 images in post processing. We studied how to fold the optical path in the imaging cells and simplified the structure, resulting in the following three advances of our previous work: 1) greater compactness (50 × 31 mm2 in the cross section), 2) less variable optical characteristics among the imaging cells, and 3) easy assembly thanks to small number of optical components constructing the imaging cell. PMID:25089420

  9. Effects of design variables on the critical stresses of eye bars under load: an evaluation by photoelastic modeling

    Energy Technology Data Exchange (ETDEWEB)

    Scott, R.G.; Stone, J.C.

    1982-01-08

    Textbooks on machine design and other relevant handbooks have not approached in depth the problem of estimating the effects of major design variables on the critical stresses in eye-bar lugs used for heavy lifting. The critical stresses determined experimentally by the photoelastic modeling of design variations of geometry and pin clearance with and without a bushing between the pin and the lug are discussed. Experimental data are compared to values developed from theoretical analysis.

  10. Research on design multi-points performance curves of pump

    International Nuclear Information System (INIS)

    The centrifugal pump's performance curves are the most important chart to reveal relevance of different performance parameters. They can show pump's function comprehensively and graphically. However these curves can't be predicted and designed precisely, duo to the complicated flow inside the impeller and the incomplete way to design pump. The complete shape of performance curves can be gained only after test. With the development of industry, many applications need the pump operating well at different flow conditions. It means the pump's performance curves should pass some specific points. This is a problem to the designer who still uses the traditional way to design pumps. In this paper, the Design of experiments was applied to arrange a plan of experiments. Because the theory equations of performance curves contain many geometry factors of impeller, changing these factors have different influence on the shape of curves, the relationship between geometry factors and the performance under different operation points been attained after using variance analysis to deal with experiment data. The relevant regression models and graphs were drawn to help understand these relationships. Depending on the predicted values of geometry factors pump's impeller was redesigned, and the pump's performance been simulated for saving time and cost. Test shows that the shape of performance curves satisfy design objective, this example can be taken as a reference of pump's specific desigen as a reference of pump's specific designs.

  11. Research on design multi-points performance curves of pump

    Science.gov (United States)

    Li, L.; Li, H.; Xu, D. H.

    2012-11-01

    The centrifugal pump's performance curves are the most important chart to reveal relevance of different performance parameters. They can show pump's function comprehensively and graphically. However these curves can't be predicted and designed precisely, duo to the complicated flow inside the impeller and the incomplete way to design pump. The complete shape of performance curves can be gained only after test. With the development of industry, many applications need the pump operating well at different flow conditions. It means the pump's performance curves should pass some specific points. This is a problem to the designer who still uses the traditional way to design pumps. In this paper, the Design of experiments was applied to arrange a plan of experiments. Because the theory equations of performance curves contain many geometry factors of impeller, changing these factors have different influence on the shape of curves, the relationship between geometry factors and the performance under different operation points been attained after using variance analysis to deal with experiment data. The relevant regression models and graphs were drawn to help understand these relationships. Depending on the predicted values of geometry factors pump's impeller was redesigned, and the pump's performance been simulated for saving time and cost. Test shows that the shape of performance curves satisfy design objective, this example can be taken as a reference of pump's specific designs.

  12. Using saddle points for challenging optical design tasks

    Science.gov (United States)

    Livshits, Irina; Hou, Zhe; van Grol, Pascal; Shao, Yifeng; van Turnhout, Maarten; Urbach, Paul; Bociort, Florian

    2014-09-01

    The present research is part of an effort to develop tools that make the lens design process more systematic. In typical optical design tasks, the presence of many local minima in the optical merit function landscape makes design non-trivial. With the method of Saddle Point Construction (SPC) which was developed recently ([F. Bociort and M. van Turnhout, Opt. Engineering 48, 063001 (2009)]) new local minima are obtained efficiently from known ones by adding and removing lenses in a systematic way. To illustrate how SPC and special properties of the lens design landscape can be used, we will present the step-by-step design of a wide-angle pinhole lens and the automatic design of a 9-lens system which, after further development with traditional techniques, is capable of good performance. We also give an example that shows how to visualize the saddle point that can be constructed at any surface of any design of an imaging system that is a local minimum.

  13. Healthy Eyes, Healthy Body

    Science.gov (United States)

    ... eyes and body healthy. How to Use the Curriculum The first chapter of this curriculum is an ... to the eye and health. Who is this Curriculum For? This curriculum is designed for multiple uses, ...

  14. Reconfigurable point-of-care systems designed with interoperability standards.

    Science.gov (United States)

    Warren, Steve; Yao, Jianchu; Schmitz, Ryan; Lebak, Jeff

    2004-01-01

    Interoperability standards, if properly applied to medical system design, have the potential to decrease the cost of point-of-care monitoring systems while better matching systems to patient needs. This paper presents a brief editorial overview of future monitoring environments, followed by a short listing of smart-home and wearable-device efforts. This is followed by a summary of recent efforts in the Medical Component Design Laboratory at Kansas State University to address interoperability issues in point-of-care systems by incorporating the Bluetooth Host Controller Interface, the IEEE 1073 Medical Information Bus, and Health Level 7 (HL7) into a monitoring system that hosts wearable or nearby wireless devices. This wireless demonstration system includes a wearable electrocardiogram, wearable pulse oximeter, wearable data logger, weight scale, and LabVIEW base station. Data are exchanged between local and remote MySQL databases using the HL7 standard for medical information exchange. PMID:17270979

  15. Oil-points - Designers means to evaluate sustainability of concepts

    DEFF Research Database (Denmark)

    Bey, Niki; Lenau, Torben Anker

    1998-01-01

    Designers have an essential influence on product design and are therefore one target group for environmental evaluation methods. This implies, that such evaluation methods have to meet designers requirements. Evaluation of sustainability of products is often done using formal Life Cycle Assessment (LCA) methods. The different LCA based methodologies consider different environmental exchanges and are often rather complex.In this context, the authors raise the question, whether a simplified LCA method which is only based on energy considerations can be used as a tool for quick overviews. This is investigated by means of three case studies where environmental impact is estimated using the EDIP method, the Eco-indicator 95 method, and the Oil Point method proposed by the authors. It is found that the results obtained using Oil Points are in acceptable conformity with the results obtained with more complex methods. This, however, is only valid as long as chemical substances can be neglected in the considered life cycle systems. Comments from workshops with designers, where the cases were presented, are included in the paper.

  16. Designed porous media: Optimally nonuniform flow structures connecting one point with more points

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez, J.C.; Bejan, A. [Department of Mechanical Engineering and Materials Science, Duke University, Box 90300, 27708-0300, Durham, NC (United States); Cherry, R.S. [Idaho National Engineering and Environmental Laboratory, P.O. Box 1625, 83415-2203, Idaho Falls, ID (United States)

    2003-09-01

    This paper shows analytically and numerically how an originally uniform flow structure transforms itself into a nonuniform one when the objective is to minimize global flow losses. The flow connects one point (source, sink) to a number of points (sinks, sources) distributed uniformly over a two-dimensional domain. In the first part of the paper, the flow between neighboring points is modeled as fully developed through round tubes. It is shown that flow 'mal-distribution' and the abandonment of symmetry are necessary for the development of flow structures with minimal resistance. The search for better flow structures can be accelerated: tubes that show a tendency of shrinking during the search can be assumed absent in future steps of structure optimization. In the second part of the paper, the flow medium is continuous and permeated by Darcy flow. The development of flow structures (channels) is modeled as a mechanism of erosion, where elements of the original medium are removed one by one, and are replaced with a more permeable medium. The elements selected for removal are identified based on two criteria: maximum pressure integrated over the element boundary, and maximum pressure gradient. The flow structures generated based on the pressure gradient criterion have consistently smaller flow resistances. As flow systems become smaller and more compact, the flow systems themselves become ''designed porous media''. These design optimization trends revealed are generally applicable in constructal design, i.e., where miniaturization, global performance, compactness and complexity rule the design. (authors)

  17. Dynamic changes in corneal topography and its influence on the point-spread function of the eye

    Science.gov (United States)

    Siedlecki, Damian; Kasprzak, Henryk; Pierscionek, Barbara K.

    2007-03-01

    The dynamic changes of the anterior surface of the eye are investigated. A Twyman-Green interferometer is used to record topographic images at 40 ms intervals. A method of analysis of the dynamic changes in topography by use of Zernike polynomials enables a general distinction to be made between dynamic alterations in the shape of the cornea itself and the changes in the layer of the tears. The influence of deviations in the shape of the anterior surface of the eye on the retinal image is estimated.

  18. A novel design of submicron thin film point contacts

    International Nuclear Information System (INIS)

    A thin film point contact design applicable to SIS-, SNS-, and microbridge-type Josephson junctions is presented, which offers potentially advanced junction characteristics (low capacitance, low stray inductance, increased quasi-particle resistance). The design philosophy is based on the fact that a point contact results if two planes having a common symmetry axis but oriented perpendicular to each other are brought into contact with each other. For the case of thin films, instead of two-dimensional planes, the cross section of the resulting ''point''-contact is defined by the thicknesses of the two thin films. Film thicknesses can be controlled much more precisely than lateral dimensions created by lithography. Hence, submicron junction geometries can be achieved using only conventional fabrication techniques. Following this idea, Josephson weak links of the ultrashort microbridge-type have been fabricated by an all-Nb technique having a 0.3-?m X 0.2-?m cross section with a R /SUB q/ I /SUB c/ product (R /SUB q/ = quasiparticle resistance, I /SUB c/ = critical current) of more than 20 mV

  19. Design of laser radar-based feature points measurement scheme

    Science.gov (United States)

    He, Binggao; An, Zhiyong

    2014-09-01

    With the development of scientific technology, the requirement of aircraft level measurement technology is growing. The traditional measurement method and device have become the bottleneck of the production. The optical 3D large-size measurement technique, with the advantages of large measurement scale, high accuracy, high generality, high flexibility and automatic measurement, has becomes the primary technique for measuring the geometry of large-size object. For the actual problems existed in the routine the feature points of level measure technology, such as failure to meet required degree of accuracy, lower efficiency and slower speed of data processing, this paper puts forwards a new measuring scheme on the feature-points of aircraft level measure by using the optical measurement system of Laser radar. Initially, the measuring principle analysis has been performed based on the optical measurement system of Laser radar. The measurement scheme of the feature-points of level measure has been carried out on the basis of the principle. And then, it makes profound analysis of the key technology which includes the technology of CCD image alignment and station-moving measurement. After the actual detection, the combined error of each feature-point is less than the comprehensive error 0.3mm, meeting the measuring scheme of accuracy index. Analysis results demonstrate that design of the measuring scheme is effective, and can meet the requirements of actual applications.

  20. Change point analysis and assessment : An integrated methodological design

    DEFF Research Database (Denmark)

    Müller, Sabine; Neergaard, Helle

    2011-01-01

    The aim of this article is to develop an analytical framework for studying processes such as continuous innovation and business development in high-tech SME clusters that transcends the traditional qualitative-quantitative divide. The article's key contribution is the conceptual integration of four existing and well-recognised but separate approaches to studying events, processes, and change, namely change-point analysis (CPA), event-history analysis (EHA), critical-incident technique (CIT), and sequence analysis (SA) into a single design framework which is especially useful for studying complex and long-term or ongoing processes.

  1. Designing the HMD for perfection: a look at the human eye-brain system

    Science.gov (United States)

    Havig, Paul R.; McIntire, John P.; Geiselman, Eric

    2012-06-01

    As we near the ability in microdisplay technology development to surpass the resolution of the human eye, it is worth reviewing this remarkable sensor to better understand where future needs may be. In this paper we review the human eye and then compare current and future trending applications for helmet mounted displays. We aim to show best practices for development of new and innovative displays that work with the human rather than against the human.

  2. Eye redness

    Science.gov (United States)

    Bloodshot eyes; Red eyes; Scleral infection; Conjunctival infection ... There are many causes of a red eye or eyes. Some are medical emergencies and some are a cause for concern, but not an emergency. Others are nothing to worry about. ...

  3. Dry Eye

    Science.gov (United States)

    ... Education Programs Training and Jobs Facts About Dry Eye Listen This information was developed by the National ... the best person to answer specific questions. Dry Eye Defined What is dry eye? Dry eye occurs ...

  4. Systems analysis in support of the selection of the ARIES-RS design point

    International Nuclear Information System (INIS)

    Systems analysis has been instrumental in the determination of the ARIES-RS reference design point through the evaluation of design options and the economic optimization of design variables. The ARIES-RS reference design point is described as modeled by the ARIES systems code. Parametric sensitivities about the ARIES-RS reference design point are presented that illustrate the economic impact of various design choices considered within the ARIES-RS design study. (orig.)

  5. 77 FR 71826 - Designation of Potential Wilderness as Wilderness, Point Reyes National Seashore

    Science.gov (United States)

    2012-12-04

    ...Wilderness as Wilderness, Point Reyes National Seashore AGENCY: National Park Service...public that all uses in Point Reyes National Seashore that are prohibited by the...designated 25,370 acres in Point Reyes National Seashore as wilderness and...

  6. Design and analysis of an adaptive lens that mimics the performance of the crystalline lens in the human eye

    Science.gov (United States)

    Santiago-Alvarado, Agustin; Cruz-Félix, Angel S.; Iturbide-Jiménez, F.; Martínez-López, M.; Ramírez-Como, M.; Armengol-Cruz, V.; Vásquez-Báez, I.

    2014-09-01

    Tunable lenses are optical systems that have attracted much attention due to their potential applications in such areas like ophthalmology, machine vision, microscopy and laser processing. In recent years we have been working in the analysis and performance of a liquid-filled variable focal length lens, this is a lens that can modify its focal length by changing the amount of water within it. Nowadays we extend our study to a particular adaptive lens known as solid elastic lens (SEL) that it is formed by an elastic main body made of Polydimethylsiloxane (PDMS Sylgard 184). In this work, we present the design, simulation and analysis of an adaptive solid elastic lens that in principle imitates the accommodation process of the crystalline lens in the human eye. For this work, we have adopted the parameters of the schematic eye model developed in 1985 by Navarro et al.; this model represents the anatomy of the eye as close as possible to reality by predicting an acceptable and accurate quantity of spherical and chromatic aberrations without any shape fitting. An opto-mechanical analysis of the accommodation process of the adaptive lens is presented, by simulating a certain amount of radial force applied onto the SEL using the finite element method with the commercial software SolidWorks®. We also present ray-trace diagrams of the simulated compression process of the adaptive lens using the commercial software OSLO®.

  7. Pointing control system design and performance evaluation of TPF coronagraph

    Science.gov (United States)

    Liu, Kuo-Chia; Blaurock, Carl; Mosier, Gary E.

    2004-09-01

    The Terrestrial Planet Finder (TPF) project aims to detect and characterize extra-solar Earth-like planets. The coronagraph telescope is one of the two mission concepts being studied. To reject the star flux and detect the planet flux in the visible light range, the coronagraph telescope must achieve a rejection ratio on the order of a billion to one. Dynamic jitter, introduced by environmental and on-board mechanical disturbances, degrades the optical performance, as characterized primarily by contrast ratio. The feasibility of using passive vibration isolation combined with active attitude and line-of-sight (LOS) control systems to stabilize the spacecraft and the optical components to the requisite level is being studied. The telescope is also required to slew between targets or rotate around the LOS. The slew mode control law must be designed to balance the need for efficient large-angle maneuvers while simultaneously avoiding the excitation of flexible modes in order to minimize settling time. This paper provides an overview of the current control design concept and sensor/actuator topology for TPF Coronagraph and illustrates the fine pointing performance of the telescope. This performance is primarily a function of the rejection of high-frequency dynamic disturbances, in this case due to reaction wheel disturbance forces/torques transmitted through the passive isolation stage. Trade studies between isolator force rejection and disturbance level reduction via wheel redesign are also presented to illustrate the requirements imposed on current technologies. Finally, the paper summarizes preliminary results on the slew/settle performance of the telescope.

  8. Studying nanostructured nipple arrays of moth eye facets helps to design better thin film solar cells

    International Nuclear Information System (INIS)

    Nipples on the surface of moth eye facets exhibit almost perfect broadband anti-reflection properties. We have studied the facet surface micro-protuberances, known as corneal nipples, of the chestnut leafminer moth Cameraria ohridella by atomic force microscopy, and simulated the optics of the nipple arrays by three-dimensional electromagnetic simulation. The influence of the dimensions and shapes of the nipples on the optics was studied. In particular, the shape of the nipples has a major influence on the anti-reflection properties. Furthermore, we transferred the structure of the almost perfect broadband anti-reflection coatings to amorphous silicon thin film solar cells. The coating that imitates the moth-eye array allows for an increase of the short circuit current and conversion efficiency of more than 40%.

  9. Onboard utilization of ground control points for image correction. Volume 3: Ground control point simulation software design

    Science.gov (United States)

    1981-01-01

    The software developed to simulate the ground control point navigation system is described. The Ground Control Point Simulation Program (GCPSIM) is designed as an analysis tool to predict the performance of the navigation system. The system consists of two star trackers, a global positioning system receiver, a gyro package, and a landmark tracker.

  10. Trajectory design for space missions to libration point L2.

    Science.gov (United States)

    Di Salvo, Alessio

    2005-12-01

    This work is focused on the detection and computation of "free" transfer trajectories from parking orbits around the Earth to quasiperiodic orbits around the collinear libration point L(2), in the Sun-Earth system; no correction or insertion maneuvers into the final orbits have been considered. The circular restricted three-body problem is the mathematical model used to describe the motion of a spacecraft, in the gravitational field of the two primaries, computed by integrating the nonlinearized equations of motion. A shooting method has been designed and developed to determine the increment of velocity required for the perigee maneuver, which injects a spacecraft into its transfer trajectory: first the velocity boundary for the Earth escape/capture condition is detected and then an iterative bisection method is applied until the burnout velocity, tangential to the parking orbit, leads the spacecraft to its final Lissajous orbit. For a launch from Kourou at local noon, Ariane5 GTO and Soyuz GTO "equivalent" have been studied and compared, considering fuel minimization for the transfer maneuver and general mission constraints, as maximum excursion of the final Lissajous orbit from the ecliptic plane and eclipses avoidance during the mission. This analysis highlights advantages and drawbacks of various parking orbits. Mission goals are the key factor for the tradeoff among orbit selection, launch options, and the other constraints, fixed by mission requirements. PMID:16510417

  11. The Modular Point Design for Heavy Ion Fusion

    International Nuclear Information System (INIS)

    We report on an ongoing study on modular Heavy Ion Fusion drivers. The modular driver is characterized by 10 to 20 nearly identical induction linacs, each carrying a single high current beam. In this scheme, the Integrated Research Experiment (IRE) can be one of the full size induction linacs. Hence, this approach offers significant advantages in terms of driver development path. For beam transport, these modules use solenoids which are capable of carrying high line charge densities, even at low energies. A new injector concept allows compression of the beam to high line densities right at the source. The final drift compression is performed in a plasma, in which the large repulsive space charge effects are neutralized. Finally, the beam is transversely compressed onto the target, using either external solenoids or current-carrying channels (in the Assisted Pinch Mode of beam propagation). We will report on progress towards a self-consistent point design from injector to target. Considerations of driver architecture, chamber environment as well as the methodology for meeting target requirements of spot size, pulse shape and symmetry will also be described. Finally, some near-term experiments to address the key scientific issues will be discussed

  12. Fast ignition integrated experiments and high-gain point design

    International Nuclear Information System (INIS)

    Integrated fast ignition experiments were performed at ILE, Osaka, and LLE, Rochester, in which a nanosecond driver laser implodes a deuterated plastic shell in front of the tip of a hollow metal cone and an intense ultrashort-pulse laser is injected through the cone to heat the compressed plasma. Based on the initial successful results of fast electron heating of cone-in-shell targets, large-energy short-pulse laser beam lines were constructed and became operational: OMEGA-EP at Rochester and LFEX at Osaka. Neutron enhancement due to heating with a ?kJ short-pulse laser has been demonstrated in the integrated experiments at Osaka and Rochester. The neutron yields are being analysed by comparing the experimental results with simulations. Details of the fast electron beam transport and the electron energy deposition in the imploded fuel plasma are complicated and further studies are imperative. The hydrodynamics of the implosion was studied including the interaction of the imploded core plasma with the cone tip. Theory and simulation studies are presented on the hydrodynamics of a high-gain target for a fast ignition point design. (special topic)

  13. The Modular Point Design for Heavy Ion Fusion

    International Nuclear Information System (INIS)

    We report on an ongoing study on modular Heavy Ion Fusion drivers. The modular driver is characterized by tens (? 20) nearly identical induction linacs, each carrying a single high current beam. In this scheme, the Integrated Research Experiment (IRE) can be one of the full size induction linacs. Hence, this approach offers significant advantages in terms of driver development path. For beam transport, these modules use solenoids which are capable of carrying high line charge densities, even at low energies. A new injector concept allows compression of the beam to high line densities right at the source. The final drift compression is performed in a plasma, in which the large repulsive space charge effects are neutralized. Finally, the beam is transversely compressed onto the target, using either external solenoids or current-carrying channels (in the Assisted Pinch Mode of beam propagation). We will report on progress towards a self-consistent point design from injector to target. Considerations of driver architecture, chamber environment as well as the methodology for meeting target requirements of spot size, pulse shape and symmetry will also be described. Finally, some near-term experiments to address the key scientific issues will be discussed

  14. Towards a Modular Point Design for Heavy Ion Fusion

    International Nuclear Information System (INIS)

    We report on an ongoing study on modular Heavy Ion Fusion (HIF) drivers. The modular driver is characterized by ?20 nearly identical induction linacs, each carrying a single high current beam. In this scheme, one of the full size induction linacs can be tested as an 'integrated Research Experiment' (IRE). Hence this approach offers significant advantages in terms of driver development path. For beam transport, these modules use solenoids, which are capable of carrying high line charge densities, even at low energies. A new injector concept allows compression of the beam to high line densities right after the source. The final drift compression is performed in a plasma in which the large repulsive space charge effects are neutralized. Finally, the beam is transversely compressed onto the target, using either external solenoids or current-carrying channels (in the assisted pinch mode of beam propagation). We report on progress towards a self-consistent point design from injector to target. Considerations of driver architecture, chamber environment as well as the methodology for meeting target requirements of spot size, pulse shape and symmetry are also described. Finally, some near-term experiments to address the key scientific issues are discussed

  15. Eye Wear

    Science.gov (United States)

    Eye wear protects or corrects your vision. Examples are Sunglasses Safety goggles Glasses (also called eyeglasses) Contact ... jobs and some sports carry a risk of eye injury. Thousands of children and adults get eye ...

  16. Eye Cancer

    Science.gov (United States)

    Cancer of the eye is uncommon. It can affect the outer parts of the eye, such as the eyelid, which are made up ... adults are melanoma and lymphoma. The most common eye cancer in children is retinoblastoma, which starts in ...

  17. The design of a saccade-size predictor for eye communication.

    Science.gov (United States)

    ten Kate, J H; van Nifterick, W

    1988-01-01

    A method for predicting the end position of a saccade, based on the peak velocity/amplitude relationship, was studied for application in eye communication. An analogue delay line of the bucket brigade type was implemented for measuring the saccadic velocity on-line. The magnitude of the differentiated saccade-signal had been subdivided in discrete values, corresponding to the distances between the neighbouring LEDs at the characters in a row of the communication board. An up-down counter started one by one the successive switching-on of the LEDs at each step in the saccadic velocity staircase. A single emitting LED corresponded finally to a predicted eye position. The signal-to-noise ratio of the detecting transistors of the infrared limbus-reflection method determined the confidence limits in prediction of the saccadic sizes. Predictions turned out to be reliable over 6 characters at 3 degrees equidistant locations in a horizontal row. It is concluded in a discussion that the feasibility of a two-dimensional fast eye keyboard system can be studied by one saccade-size predictor in combination with the magnetic field scleral search coil technique. PMID:2972903

  18. Eye to Eye (Illuminations)

    Science.gov (United States)

    2008-01-01

    In this two-day lesson plan students collect, display, and analyze data about the eye color of their classmates. On day one, students display the eye color data in a pictograph and discuss what questions can and cannot be answered using this graph. On the second day of the lesson, data from a partner class is used to create a second pictograph. Students then compare these graphs and determine what questions can and cannot be answered using these two graphs. Questions and extension suggestions (including making a circle graph to represent data) are also included in the lesson plan.

  19. Teach Graphic Design Basics with PowerPoint

    Science.gov (United States)

    Lazaros, Edward J.; Spotts, Thomas H.

    2007-01-01

    While PowerPoint is generally regarded as simply software for creating slide presentations, it includes often overlooked--but powerful--drawing tools. Because it is part of the Microsoft Office package, PowerPoint comes preloaded on many computers and thus is already available in many classrooms. Since most computers are not preloaded with good…

  20. THE INFLUENCE OF EYES AND BRAIN BEHIND "ARTERMA TOOL" IN FIRST PERSON POINT OF VIEW INTERFACE OF GAMES

    OpenAIRE

    Irma Shayana Samaden; Azizah Jaafar; Irza Shayani Samaden

    2014-01-01

    The application of point of view (POV) in electronic games has been vastly applied and fast becoming a favorite among electronic games (EG) players particularly in games of action genre like warfare games. While allowing the users to experience the character first-hand, POV has its limitations for users. One example of the problems is the difficulty to anticipate the direction an attack by the enemy from a POV blindspot. Another problem is the difficulty to prepare a strategy. Some players be...

  1. Design and Simulation of Floating Point Multiplier Based on VHDL

    Science.gov (United States)

    Remadevi, R.

    2013-03-01

    Multiplying floating point numbers is a critical requirement for DSP applications involving large dynamic range. This paper focuses only on single precision normalized binary interchange format targeted for Xilinx Spartan-3 FPGA based on VHDL. The multiplier was verified against Xilinx floating point multiplier core. It handles the overflow and underflow cases. Rounding is not implemented to give more precision when using the multiplier in a Multiply and Accumulate (MAC) unit.

  2. Design and development of a ferroelectric micro photo detector for the bionic eye

    Science.gov (United States)

    Song, Yang

    Driven by no effective therapy for Retinitis Pigmentosa and Age Related Macular Degeneration, artificial vision through the development of an artificial retina that can be implanted into the human eye, is being addressed by the Bionic Eye. This dissertation focuses on the study of a photoferroelectric micro photo detector as an implantable retinal prosthesis for vision restoration in patients with above disorders. This implant uses an electrical signal to trigger the appropriate ocular cells of the vision system without resorting to wiring or electrode implantation. The research work includes fabrication of photoferroelectric thin film micro detectors, characterization of these photoferroelectric micro devices as photovoltaic cells, and Finite Element Method (FEM) modeling of the photoferroelectrics and their device-neuron interface. A ferroelectric micro detector exhibiting the photovoltaic effect (PVE) directly adds electrical potential to the neuron membrane outer wall at the focal adhesion regions. The electrical potential then generates a retinal cell membrane potential deflection through a newly developed Direct-Electric-Field-Coupling (DEFC) model. This model is quite different from the traditional electric current model because instead of current directly working on the cell membrane, the PVE current is used to generate a localized high electric potential in the focal adhesion region by working together with the anisotropic high internal impedance of ferroelectric thin films. General electrodes and silicon photodetectors do not have such anisotropy and high impedance, and thus they cannot generate DEFC. This mechanism investigation is very valuable, because it clearly shows that our artificial retina works in a way that is totally different from the traditional current stimulation methods.

  3. Preliminary Design and Analysis of the GIFTS Instrument Pointing System

    Science.gov (United States)

    Zomkowski, Paul P.

    2003-01-01

    The Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS) Instrument is the next generation spectrometer for remote sensing weather satellites. The GIFTS instrument will be used to perform scans of the Earth s atmosphere by assembling a series of field-of- views (FOV) into a larger pattern. Realization of this process is achieved by step scanning the instrument FOV in a contiguous fashion across any desired portion of the visible Earth. A 2.3 arc second pointing stability, with respect to the scanning instrument, must be maintained for the duration of the FOV scan. A star tracker producing attitude data at 100 Hz rate will be used by the autonomous pointing algorithm to precisely track target FOV s on the surface of the Earth. The main objective is to validate the pointing algorithm in the presence of spacecraft disturbances and determine acceptable disturbance limits from expected noise sources. Proof of concept validation of the pointing system algorithm is carried out with a full system simulation developed using Matlab Simulink. Models for the following components function within the full system simulation: inertial reference unit (IRU), attitude control system (ACS), reaction wheels, star tracker, and mirror controller. With the spacecraft orbital position and attitude maintained to within specified limits the pointing algorithm receives quaternion, ephemeris, and initialization data that are used to construct the required mirror pointing commands at a 100 Hz rate. This comprehensive simulation will also aid in obtaining a thorough understanding of spacecraft disturbances and other sources of pointing system errors. Parameter sensitivity studies and disturbance analysis will be used to obtain limits of operability for the GIFTS instrument. The culmination of this simulation development and analysis will be used to validate the specified performance requirements outlined for this instrument.

  4. Design and fabrication of a chirped array of refractive ellipsoidal micro-lenses for an apposition eye camera objective

    Science.gov (United States)

    Wippermann, Frank; Duparré, Jacques; Schreiber, Peter; Dannberg, Peter

    2005-09-01

    Apposition compound eye camera objectives are one approach for a vast reduction of the optical system length of an imaging optical sensor. Despite imaging the complete field of view through one aperture like in classical lenses, these objectives split the overall field of view in separated channels which are located adjoined like in insect eyes. Due to the splitting each channel can be optimized for reduction of aberrations occuring under oblique incidence. A correction for astigmatism, field curvature and distortion occurring under oblique incidence can be accomplished by the use of anamorphic micro-lenses leading to an improved resolution of the camera objective. In contrast to regular arrays of equally shaped and equidistant positioned micro-lenses the parameters of the lenses like radii of curvature, center position and angular orientation are functions of the position within the array. These functions can be derived analytically leading to a complete description of the array parameters. We present design considerations for a chirped array containing 130x130 individually shaped ellipsoidal micro-lenses. Melting of photo-resist is employed as fabrication technology for achieving diffraction limited performance. Detailed considerations for the semi-automated layout generation of the photo lithographical masks as well as characterization data of first realized prototypes of the array are given.

  5. Key points for the design of Mox facilities

    International Nuclear Information System (INIS)

    The design of a MOX fuel fabrication facility involves specific technical difficulties: - Process aspects: for example, its is necessary to meet the stringent requirements on the end products, while handling large quantities of powders and pellets; - Safety aspects: for example, containment of radioactive materials requires to use gloveboxes, to design process equipment so as to limit dispersion to the gloveboxes and to use systems for dust collection. - Technological aspects: for example, it is necessary to take into account maintenance early in the design, in order to lower the operation costs and lower the dose to the personnel. - Quality control and information systems: for example, it is necessary to be able to trace all the different products (powder lots, pellets, rods, assemblies). The design methods and organization set-up by COGEMA enables to master these technical difficulties during the different design steps and to obtain a MOX fabrication facility at the best performance versus cost compromise. These design methods rely mainly on: - taking into account all the different above mentioned constraints from the very beginning of the design process (by using the know-how resulting from experience feed-back, and also specific design tools developed by COGEMA and SGN); - launching a technical development and testing program at the beginning of the project and incorporating its results in the course of the design. (author))

  6. Eye-tracking measures reveal how changes in the design of aided AAC displays influence the efficiency of locating symbols by school-age children without disabilities.

    Science.gov (United States)

    Wilkinson, Krista M; O'Neill, Tara; McIlvane, William J

    2014-04-01

    PURPOSE Many individuals with communication impairments use aided augmentative and alternative communication (AAC) systems involving letters, words, or line drawings that rely on the visual modality. It seems reasonable to suggest that display design should incorporate information about how users attend to and process visual information. The organization of AAC symbols can influence the speed and accuracy with which children select a target symbol on a display. This research examined why some displays facilitate responding. METHOD Eye-tracking technology recorded point-of-gaze while children without disabilities engaged in a visual search task with 2 AAC displays. In 1 display, symbols sharing an internal color were clustered together. In the other display, like-colored symbols were distributed. Dependent measures were (a) latency to fixate on the target compared with distracters and (b) the number of fixations to target and distracters. RESULTS Participants were significantly slower to fixate on the target when like-colored symbols were distributed; there was a significant increase in the number of fixations to distracters that did not share color with the target. CONCLUSIONS Efficient search was related to minimizing fixations to nonrelevant distracters. Vulnerability to distraction can be a significant problem in individuals with disabilities who use AAC. Minimizing the intrusion of such distraction may, therefore, be of importance in AAC display design. PMID:24129007

  7. Optimization of the NIF ignition point design hohlraum

    International Nuclear Information System (INIS)

    In preparation for the start of NIF ignition experiments, we have designed a porfolio of targets that span the temperature range that is consistent with initial NIF operations: 300 eV, 285 eV, and 270 eV. Because these targets are quite complicated, we have developed a plan for choosing the optimum hohlraum for the first ignition attempt that is based on this portfolio of designs coupled with early NIF experiements using 96 beams. These early experiments will measure the laser plasma instabilities of the candidate designs and will demonstrate our ability to tune symmetry in these designs. These experimental results, coupled with the theory and simulations that went into the designs, will allow us to choose the optimal hohlraum for the first NIF ignition attempt

  8. Single service point: it's all in the design.

    Science.gov (United States)

    Bradigan, Pamela S; Rodman, Ruey L

    2008-01-01

    "Design thinking" principles from a leading design firm, IDEO, were key elements in the planning process for a one-desk service model, the ASK Desk, at the John A. Prior Health Sciences Library. The library administration and staff employed the methodology to enhance customer experiences, meet technology challenges, and compete in a changing education environment. The most recent renovations demonstrate how the principles were applied. The concept of "continuous design thinking" is important in the library's daily operations to serve customers most effectively. PMID:19042717

  9. THE INFLUENCE OF EYES AND BRAIN BEHIND "ARTERMA TOOL" IN FIRST PERSON POINT OF VIEW INTERFACE OF GAMES

    Directory of Open Access Journals (Sweden)

    Irma Shayana Samaden

    2014-10-01

    Full Text Available The application of point of view (POV in electronic games has been vastly applied and fast becoming a favorite among electronic games (EG players particularly in games of action genre like warfare games. While allowing the users to experience the character first-hand, POV has its limitations for users. One example of the problems is the difficulty to anticipate the direction an attack by the enemy from a POV blindspot. Another problem is the difficulty to prepare a strategy. Some players become “somewhat dizzy” and eventually give up the game. This paper elaborates on the development of a framework for interactive montage on EG software interface using ArTerma tools and how the ArTerma tool works in the POV interface. Therefore, to accomplish the development of ArTerma tools, (A1(DDI2E3 model is used. In (A1(DDI2E3 model usage, ADDIE model is combined with other model concept such as “Diegesis Spatiality” concept Model, Frame concept model, and Mental concept model has been employed along side an elaboration on case studies. The study hopes that the developed a new model as well as support tool can help improve future EGs.

  10. Design of Farthest-Point Masks for Image Halftoning

    Directory of Open Access Journals (Sweden)

    Ramponi G

    2004-01-01

    Full Text Available In an earlier paper, we briefly presented a new halftoning algorithm called farthest-point halftoning. In the present paper, this method is analyzed in detail, and a novel dispersion measure is defined to improve the simplicity and flexibility of the result. This new stochastic screen algorithm is loosely based on Kang's dispersed-dot ordered dither halftone array construction technique used as part of his microcluster halftoning method. Our new halftoning algorithm uses pixelwise measures of dispersion based on one proposed by Kang which is here modified to be more effective. In addition, our method exploits the concept of farthest-point sampling (FPS, introduced as a progressive irregular sampling method by Eldar et al. but uses a more efficient implementation of FPS in the construction of the dot profiles. The technique we propose is compared to other state-of-the-art dither-based halftoning methods in both qualitative and quantitative manners.

  11. Fiber design and realization of point-by-point written fiber Bragg gratings in polymer optical fibers

    DEFF Research Database (Denmark)

    Stefani, Alessio; Stecher, Matthias

    2012-01-01

    An increasing interest in making sensors based on fiber Bragg gratings (FBGs) written in polymer optical fibers (POFs) has been seen recently. Mostly microstructured POFs (mPOFs) have been chosen for this purpose because they are easier to fabricate compared, for example, to step index fibers and because they allow to tune the guiding parameters by modifying the microstructure. Now a days the only technique used to write gratings in such fibers is the phase mask technique with UV light illumination. Despite the good results that have been obtained, a limited flexibility on the grating design and the very long times required for the writing of FBGs raise some questions about the possibility of exporting POF FBGs and the sensors based on them from the laboratory bench to the mass production market. The possibility of arbitrary design of fiber Bragg gratings and the very short time required to write the gratings make the point-by-point grating writing technique very interesting and would appear to be able to fill this technological gap. On the other end this technique is hardly applicable for microstructured fibers because of the writing beam being scattered by the air-holes. We report on the design and realization of a microstructured polymer optical fiber made of PMMA for direct writing of FBGs. The fiber was designed specifically to avoid obstruction of the writing beam by air-holes. The realized fiber has been used to point-by-point write a 5 mm long fourth order FBG with a Bragg wavelength of 1518 nm. The grating was inspected under Differential Interferometric Contrast microscope and the reflection spectrum was measured. This is, to the best of our knowledge, the first FBGs written into a mPOF with the point-by-point technique and also the fastest ever written into a polymer optical fiber, with less than 2.5 seconds needed.

  12. Phase-shifting point diffraction interferometer grating designs

    Science.gov (United States)

    Naulleau, Patrick (Oakland, CA); Goldberg, Kenneth Alan (Berkeley, CA); Tejnil, Edita (San Carlos, CA)

    2001-01-01

    In a phase-shifting point diffraction interferometer, by sending the zeroth-order diffraction to the reference pinhole of the mask and the first-order diffraction to the test beam window of the mask, the test and reference beam intensities can be balanced and the fringe contrast improved. Additionally, using a duty cycle of the diffraction grating other than 50%, the fringe contrast can also be improved.

  13. Watery eyes

    Science.gov (United States)

    ... the eye through a small hole in the corner of the eye called the tear duct. Causes ... symptoms, including headache, stuffy or runny nose, or joint or muscle aches? What medications do you take? ...

  14. Eye Injuries

    Science.gov (United States)

    ... Most eye injuries are preventable. If you play sports or work in certain jobs, you may need protection. The most common type of injury happens when something irritates the outer surface of your eye. Certain jobs such as industrial ...

  15. Eye Anatomy

    Science.gov (United States)

    Eye Anatomy en Español email Send this article to a friend by filling out the fields below: Your name: ... You at Risk For Glaucoma? Childhood Glaucoma Eye Anatomy Five Common Glaucoma Tests Glaucoma Facts and Stats ...

  16. Anatomy of the Eye

    Science.gov (United States)

    ... Children Scientists in the Laboratory Visual Acuity Testing Anatomy of the Eye Drawing of the Eye Drawing ... Eye Normally Developing Eye Drawing of the Eye Anatomy of the Eye Drawing of the Eye Illustration ...

  17. Experimental design for single point diamond turning of silicon optics

    Energy Technology Data Exchange (ETDEWEB)

    Krulewich, D.A.

    1996-06-16

    The goal of these experiments is to determine optimum cutting factors for the machining of silicon optics. This report describes experimental design, a systematic method of selecting optimal settings for a limited set of experiments, and its use in the silcon-optics turning experiments. 1 fig., 11 tabs.

  18. Optimized design of remote point diffractive optical sensors

    International Nuclear Information System (INIS)

    We present an optimization study of surface relief grating based sensors for use in optical remote point sensing. Our study includes the effects of geometrical characteristics of the photonic structure on the efficiencies of the first and second diffraction orders and the exhibited sensor responsivities of these orders. Our predictions are verified experimentally with measurements of surface relief gratings patterned by direct laser ablation on SiO2 sol–gel nanocomposite material with embedded NiCl2 nanocrystals developed for ammonia sensing

  19. The design analysis for the main control room and standby shutdown point for HTR-PM

    International Nuclear Information System (INIS)

    This paper describes the general design of the main control room (MCR) and standby shutdown point for high temperature gas-cooled reactor-pebble module (HTR-PM). The function of design, layout of control panels and main function and characteristics of MCR and standby shutdown point are specially introduced and analyzed in detail. (author)

  20. A design pathfinder with material correlation points for inflatable systems

    Science.gov (United States)

    Fulcher, Jared Terrell

    The incorporation of inflatable structures into aerospace systems can produce significant advantages in stowed volume to mechanical effectiveness and overall weight. Many applications of these ultra-lightweight systems are designed to precisely control internal or external surfaces, or both, to achieve desired performance. The modeling of these structures becomes complex due to the material nonlinearities inherent to the majority of construction materials used in inflatable structures. Furthermore, accurately modeling the response and behavior of the interfacing boundaries that are common to many inflatable systems will lead to better understanding of the entire class of structures. The research presented involved using nonlinear finite element simulations correlated with photogrammetry testing to develop a procedure for defining material properties for commercially available polyurethane-coated woven nylon fabric, which is representative of coated materials that have been proven materials for use in many inflatable systems. Further, the new material model was used to design and develop an inflatable pathfinder system which employs only internal pressure to control an assembly of internal membranes. This canonical inflatable system will be used for exploration and development of general understanding of efficient design methodology and analysis of future systems. Canonical structures are incorporated into the design of the phased pathfinder system to allow for more universal insight. Nonlinear finite element simulations were performed to evaluate the effect of various boundary conditions, loading configurations, and material orientations on the geometric precision of geometries representing typical internal/external surfaces commonly incorporated into inflatable pathfinder system. The response of the inflatable system to possible damage was also studied using nonlinear finite element simulations. Development of a correlated material model for analysis of the inflatable pathfinder system has improved the efficiency of design and analysis techniques of future inflatable structures. KEYWORDS: Nonlinear Finite Element, Inflatable Structures, Gossamer Space Systems, Photogrammetry Measurements, Coated Woven Fabric.

  1. New Generation Nuclear Plant (NGNP) Project, Preliminary Point Design

    Energy Technology Data Exchange (ETDEWEB)

    F. H. Southworth; P. E. MacDonald; A. M. Baxter; P. D. Bayless; J. M. Bolin; H. D. Gougar; R. L. Moore; A. M. Ougouag; M. B. Richards; R. L. Sant; J. W. Sterbentz; W. K. Terry

    2004-03-01

    This paper provides a preliminary assessment of two possible versions of the Next Generation Nuclear Plant (NGNP), a prismatic fuel type helium gas-cooled reactor and a pebblebed fuel helium gas reactor. Both designs will meet the three basic requirements that have been set for the NGNP: a coolant outlet temperature of 1000 C, passive safety, and a total power output consistent with that expected for commercial high-temperature gas-cooled reactors.

  2. End-point controller design for an experimental two-link flexible manipulator using convex optimization

    Science.gov (United States)

    Oakley, Celia M.; Barratt, Craig H.

    1990-01-01

    Recent results in linear controller design are used to design an end-point controller for an experimental two-link flexible manipulator. A nominal 14-state linear-quadratic-Gaussian (LQG) controller was augmented with a 528-tap finite-impulse-response (FIR) filter designed using convex optimization techniques. The resulting 278-state controller produced improved end-point trajectory tracking and disturbance rejection in simulation and experimentally in real time.

  3. A Space-Efficient Design for Reversible Floating Point Adder in Quantum Computing

    OpenAIRE

    Nguyen, Trung Duc; Meter, Rodney

    2013-01-01

    Reversible logic has applications in low-power computing and quantum computing. However, there are few existing designs for reversible floating-point adders and none suitable for quantum computation. In this paper we propose a space-efficient reversible floating-point adder, suitable for binary quantum computation, improving the design of Nachtigal et al. Our work focuses on improving the reversible designs of the alignment unit and the normalization unit, which are the most...

  4. A point rainfall model for risk-based design

    Science.gov (United States)

    Heneker, Theresa M.; Lambert, Martin F.; Kuczera, George

    2001-06-01

    The point rainfall model presented extends previous work on event-based rainfall models and overcomes some of their shortcomings. The model uses event-based data and can be calibrated using rainfall data substantially affected by missing or corrupted values. Particular attention was given to adequately simulating extreme storm rainfall events for use in hydrological risk assessment. The model is capable of simulating the inter-event time, storm duration, average event intensity and intra-event temporal characteristics. Conditioning of the average event rainfall intensity on rainfall duration and time of year is a feature of the model. Rainfall events are disaggregated using a conditional random walk on a dimensionless mass curve. Pluviograph data in 6 min increments from three Australian capital cities (Sydney, Brisbane and Melbourne) was used to calibrate the model parameters. It was found that the constrained random walk parameters were almost identical for the three cities. The model was tested using statistics not used in its calibration and the simulated intensity-frequency-duration extreme rainfall statistics compared very favorably with observed values. In addition, simulated aggregated statistics compared favorably with observed statistics from 30 min to monthly durations. The simulated annual rainfalls significantly underestimated the observed variability for Brisbane and Sydney, whereas satisfactorily reproduced the Melbourne variability. An explanation is offered for these differences.

  5. Design and Analysis of Lightweight Pointing Mirror Used in Space Camera

    International Nuclear Information System (INIS)

    Pointing mirror is one of the critical components of space camera to get earth images. Lightweighting design and simulation analysis of mirror play a major role in weight minimization and performance optimization of camera. Based on concept of design of experiments, this paper introduces a method combined curve fit with finite element simulation analysis and optimization to the lightweighting design of pointing mirror, as well as demonstrates design procedure, performance analysis and checkout of mirror. The results indicate that this method has good maneuverability and utility. This technique could be applied to lightweighting design of mirror which has a regular topological structure

  6. Using Eye Makeup

    Science.gov (United States)

    ... the Sun Eye Health News Consumer Alerts Using Eye Makeup Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes ... over the battery and always wear safety goggles. Eye Protection Works Wearing the proper protective eyewear for ...

  7. Eye Complications

    Science.gov (United States)

    ... Diabetes Complications Skin Complications Eye Complications Neuropathy Foot Complications DKA (Ketoacidosis) & Ketones Kidney Disease (Nephropathy) High Blood Pressure (Hypertension) Stroke Hyperosmolar Hyperglycemic Nonketotic Syndrome (HHNS) Gastroparesis ...

  8. Design and construction progress on Gentilly 2, Cordoba, Point Lepreau, and Wolsung projects

    International Nuclear Information System (INIS)

    Gentilly 2, Point Lepreau, Cordoba and Wolsung are the first 600 MW CANDU nuclear generating stations to be built. Progress in their construction and in the remaining design work for these stations is discussed. (LL)

  9. Stauts of the Laser Inertial Fusion Energy (LIFE) Hohlraum Point Design

    Energy Technology Data Exchange (ETDEWEB)

    Amendt, P; Dunne, M; Ho, D; Lasinski, B; Meeker, D; Ross, J S

    2012-04-10

    Progress on the hohlraum point design for the LIFE engine is described. New features in the original design [Amendt et al., Fus. Sci. Technol. 60, 49 (2011)] are incorporated that address the imperatives of low target cost, high manufacturing throughput, efficient and prompt material recycling, an ability for near-term testing of key target design uncertainties on the National Ignition Facility, and robustness to target chamber environment and injection insults. To this end, the novel use of Pb hohlraums and aerogel-supported liquid DT fuel loading within a high-density-carbon (HDC) ablator is implemented in the hohlraum point design.

  10. Dual keel Space Station payload pointing system design and analysis feasibility study

    Science.gov (United States)

    Smagala, Tom; Class, Brian F.; Bauer, Frank H.; Lebair, Deborah A.

    1988-01-01

    A Space Station attached Payload Pointing System (PPS) has been designed and analyzed. The PPS is responsible for maintaining fixed payload pointing in the presence of disturbance applied to the Space Station. The payload considered in this analysis is the Solar Optical Telescope. System performance is evaluated via digital time simulations by applying various disturbance forces to the Space Station. The PPS meets the Space Station articulated pointing requirement for all disturbances except Shuttle docking and some centrifuge cases.

  11. Design of 16-point Radix-4 Fast Fourier Transform in 0.18µm CMOS Technology

    OpenAIRE

    Palaniappan, Siva K.; Zulkifli, Tun Z. A.

    2007-01-01

    This paper introduces detail design of semi-custom CMOS Fast Fourier Transform (FFT) architecture for computing 16-point radix-4 FFT. FFT is one of the most widely used algorithms in digital signal processing. It is used in many signal processing and communication application as an important block for various multi-carrier systems such as for WLAN (Wireless local area network). This paper describes the design of an ASIC (Application Specific Integrated Circuit) CMOS FFT processor for 16-point...

  12. Implementing programming methods in the process of designing typefaces : a designers point of view

    OpenAIRE

    Elsa Jónsdóttir 1989

    2013-01-01

    This thesis explores why designers use programming methods in typeface design, both for speeding up the process of the design itself and for adding an extra dimension to the typeface, more conceptually and for clearly professional purposes. During the process of writing the thesis the author interviewed six graphic designers from five different countries to get a wide range of opinions on various matters related to the purpose of parametrized type design and technologies in typeface design. T...

  13. Using eye-tracking methodology in consumer science

    DEFF Research Database (Denmark)

    Bialkova, S.; Mueller Loose, Simone

    Eye-tracking methodology will soon be mature enough to become a standard tool in consumer science. The workshop will begin with a short overview of the perceptual and attention processes that can be measured by eye-tracking. The available hardware and software will be compared, and typical experimental designs will be discussed that can be recommended for eye-tracking studies in consumer science. The application potential will then be demonstrated in four case presentations, focusing on different product categories (from dairy products to alcoholic beverages), measurement contexts (laboratory versus point of purchase) and study goals (appearance studies, package design, identification of food choice motives). Furthermore, the presentations will discuss how different components of attention can be distinguished based on eye-tracking data (stimulus-driven versus task-driven processes) and how the explanatory power of eye-tracking studies can be boosted by combining eye-tracking with other methodologies (shelf simulations, choice experiments, neuroimaging techniques). The workshop will conclude with an open discussion in which participants can consult the presenters on the applicability of eye-tracking methods in their own research.

  14. Black Eye

    Science.gov (United States)

    ... Screening Guidelines Home Remedies for Simple Eye Problems Medical Marijuana for Glaucoma Pregnancy Preventing Eye Injuries Smokers Sports ... Policy Email address ... text or images from this website is strictly prohibited by US and international copyright law. You may link from your website to any ...

  15. Novel small-eye allele in paired box gene 6 (Pax6) is caused by a point mutation in intron 7 and creates a new exon

    Science.gov (United States)

    Puk, Oliver; Yan, Xiaohe; Sabrautzki, Sibylle; Fuchs, Helmut; Gailus-Durner, Valérie; Hrab? de Angelis, Martin

    2013-01-01

    Purpose Within a mutagenesis screen, we identified the new mouse mutant Aey80 with small eyes; homozygous mutants were not obtained. The aim of the study was its molecular characterization. Methods We analyzed the offspring of paternally N-ethyl-N-nitrosourea (ENU)–treated C3HeB/FeJ mice for dysmorphology parameters, which can be observed with the naked eye. The Aey80 mutant (abnormality of the eye) was further characterized with laser interference biometry, Scheimpflug imaging, and optical coherence tomography. Linkage analysis of the Aey80 mutant was performed using a panel of single nucleotide polymorphisms different among C3HeB/FeJ and C57BL/6J mice. The Aey80 mutation was identified with sequence analysis of the positional candidate gene. Results We identified a new mutant characterized by an obvious small-eye phenotype; homozygotes are not viable after birth. Embryos at embryonic day 15.5 demonstrate a clear gene-dosage effect: Heterozygotes have small eyes, whereas homozygous mutants do not have eyes. In adult mice, the lenses and the entire eyes of the heterozygous mutants were significantly smaller than those of the wild-types (pA exchange four bases downstream of the end of the alternative exon. The alternative exon in the mutants is predicted to encode 30 novel amino acids and three stop codons. This alternative exon kept the paired domain intact but led to a loss of the homeodomain and the C-terminal proline-serine-threonine (PST) domain. The mutation cosegregated in the mutant line, since all five additional small-eyed mice from this line showed the same mutation. A general polymorphism at the mutated site was excluded with sequence analysis of seven other wild-type mouse strains different from C3HeB/FeJ. Conclusions These findings demonstrate a novel allele of the paired box gene 6 (Pax6) that affects lens development in a semidominant manner leading to a classical small-eye phenotype. However, the site of the mutation more than 1 kb downstream of exon 7 and resulting in an alternative exon is quite unusual. It indicates the importance of sequence analysis of cDNA for mutation detection; mutations like this are unlikely to be identified by analyzing genomic sequences only. Moreover, this particular mutation demonstrates how a novel exon can be created by only a single base-pair exchange. PMID:23592925

  16. Wheelchair Motion Control Guide Using Eye Movement Based on EEG Signals.

    OpenAIRE

    Uma Mageswar, D.; Selvavinayagam, G.

    2013-01-01

    The design and implementation of an Autonomous Movement Robot based on a Wheelchair based on EOG signal is to help a disable or handicapped person. These EOG electrodes are placed at right and left of eye and other pair of electrodes are at top and right of the eye. These electrodes used to response after gazing of one target point for a particular time period. After gazing of point, the wheelchair used to move to a target position. So, it produce delay during eye gaze. To overcome this delay...

  17. The Draize eye test.

    Science.gov (United States)

    Wilhelmus, K R

    2001-01-01

    Hundreds of substances are used daily that can damage eyesight. People's eyes are open to accidental or intentional exposure during the production, transportation, use, and disposal of chemical preparations. Ensuring the safety of consumer products was born during the mid twentieth century in the aftermath of chemical warfare research, and was motivated by the hazards of unsafe cosmetics. Justified by an exigency for public protection, the Draize eye test became a governmentally endorsed method to evaluate the safety of materials meant for use in or around the eyes. The test involves a standardized protocol for instilling agents onto the cornea and conjunctiva of laboratory animals. A sum of ordinal-scale items of the outer eye gives an index of ocular morbidity. Advances in ocular toxicology are challenging the validity, precision, relevance, and need of the Draize eye test. Preclinical product-safety tests with rabbits and other mammals also raise ethical concerns of animal wellbeing. Some use the Draize test as a rallying point for how animals are treated in science and industry. A battery of cellular systems and computer models aim to reduce and ultimately to replace whole-animal testing. Molecular measures of ocular toxicity may eventually allow comprehensive screening in humans. The Draize eye test was created and refined for humanitarian reasons and has assuredly prevented harm. Its destiny is to be progressively supplanted as in vitro and clinical alternatives emerge for assessing irritancy of the ocular surface. PMID:11425356

  18. Eye dilation

    Science.gov (United States)

    Greyson Orlando (None; )

    2006-12-11

    The iris is the colored part of the eye. The pupil is the dark circle in the middle of the iris. The iris causes the pupil to expand or contract depending on the amount of light in a given area. Once light passes through the pupil, a structure called the lens that is directly behind the pupil focuses the light at the back of the eye. The optic nerve, located at the back of the eye, takes the focused message and relays it to the brain where it is processed into an image.

  19. Reliability of impingement sampling designs: An example from the Indian Point station

    International Nuclear Information System (INIS)

    A 4-year data base (1976-1979) of daily fish impingement counts at the Indian Point electric power station on the Hudson River was used to compare the precision and reliability of three random-sampling designs: (1) simple random, (2) seasonally stratified, and (3) empirically stratified. The precision of daily impingement estimates improved logarithmically for each design as more days in the year were sampled. Simple random sampling was the least, and empirically stratified sampling was the most precise design, and the difference in precision between the two stratified designs was small. Computer-simulated sampling was used to estimate the reliability of the two stratified-random-sampling designs. A seasonally stratified sampling design was selected as the most appropriate reduced-sampling program for Indian Point station because: (1) reasonably precise and reliable impingement estimates were obtained using this design for all species combined and for eight common Hudson River fish by sampling only 30% of the days in a year (110 d); and (2) seasonal strata may be more precise and reliable than empirical strata if future changes in annual impingement patterns occur. The seasonally stratified design applied to the 1976-1983 Indian Point impingement data showed that selection of sampling dates based on daily species-specific impingement variability gave results that were more precise, but not more consistently reliable, than sampling allocations based on the variability ling allocations based on the variability of all fish species combined. 14 refs., 1 fig., 6 tabs

  20. Healthy Eyes

    Science.gov (United States)

    ... Low Vision Education Program Spanish-language Education Program (¡Ojo con su visión!) Vision and Aging Program Training ... Eye Care En español La enfermedad diabética del ojo La enfermedad diabética del ojo ¿Cuánto sabe sobre ...

  1. Dry eyes

    Science.gov (United States)

    ... pain, swelling, or stiffness. You also have a dry mouth. Your dry eyes do not respond to self- ... cosmetics? Do you have any other symptoms like dry mouth or joint discomfort? Your health care provider may ...

  2. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Children & Teenagers Computer Usage Diabetes Diet & Nutrition Eye Injuries Eye Screening Guidelines Home Remedies for Simple Eye Problems Medical Marijuana for Glaucoma Pregnancy Preventing Eye Injuries Smokers Sports Using Eye Makeup Veterans What Is ...

  3. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During Pregnancy Computer Usage & Eye Strain Maintaining Your Sight with Diabetes Sports and Eye Protection Eyesight Risks for Smokers Veterans & ...

  4. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Water & Contacts Don’t Mix To help prevent eye ... right eye care provider for your condition or treatment. Are You Fit at 40? A baseline eye ...

  5. Eye Injuries at Home

    Science.gov (United States)

    ... Eyes & the Sun Eye Health News Consumer Alerts Eye Injuries at Home Tweet You might think that ... the American National Standards Institute eye protection standard.) Eye Injury Risks in the House Using hazardous products ...

  6. Eye Injuries (For Parents)

    Science.gov (United States)

    ... the Flu Pregnancy Precautions Checkups: What to Expect Eye Injuries KidsHealth > Parents > First Aid & Safety > Emergencies > Eye ... do not delay flushing the eye first. Black Eyes and Blunt Injuries A black eye is often ...

  7. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During Pregnancy Computer Usage & Eye Strain Maintaining Your ... over the battery and always wear safety goggles. Eye Protection Works Wearing the proper protective eyewear for ...

  8. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Marijuana for Glaucoma Pregnancy Preventing Eye Injuries Smokers Sports Using Eye Makeup Veterans What Is an Ophthalmologist? Your Eyes & the Sun Eye Health News Consumer Alerts What Is Dry Eye? Tweet ...

  9. Design of a new high-performance pointing controller for the Hubble Space Telescope

    Science.gov (United States)

    Johnson, C. D.

    1993-01-01

    A new form of high-performance, disturbance-adaptive pointing controller for the Hubble Space Telescope (HST) is proposed. This new controller is all linear (constant gains) and can maintain accurate 'pointing' of the HST in the face of persistent randomly triggered uncertain, unmeasurable 'flapping' motions of the large attached solar array panels. Similar disturbances associated with antennas and other flexible appendages can also be accommodated. The effectiveness and practicality of the proposed new controller is demonstrated by a detailed design and simulation testing of one such controller for a planar-motion, fully nonlinear model of HST. The simulation results show a high degree of disturbance isolation and pointing stability.

  10. Right Eye/Left Eye

    Science.gov (United States)

    2012-06-26

    In this activity (3rd on the page), learners conduct a series of tests to find out which of their eyes is more dominant. In other words, do they prefer to use their right or left eye to complete tasks? Learners work in pairs and observe each other doing simple tasks like looking through a tube, "sighting" an object across the room, and looking through a hole. Learners collect data to draw conclusions about their partner's "eyedness."

  11. Design of 16-point Radix-4 Fast Fourier Transform in 0.18µm CMOS Technology

    Directory of Open Access Journals (Sweden)

    Siva K. Palaniappan

    2007-01-01

    Full Text Available This paper introduces detail design of semi-custom CMOS Fast Fourier Transform (FFT architecture for computing 16-point radix-4 FFT. FFT is one of the most widely used algorithms in digital signal processing. It is used in many signal processing and communication application as an important block for various multi-carrier systems such as for WLAN (Wireless local area network. This paper describes the design of an ASIC (Application Specific Integrated Circuit CMOS FFT processor for 16-point radix-4 complex FFT computation, realized utilizing 0.18µm standard CMOS technology. Fixed point data format is preferred in comparison of floating point data format for a shorter dynamic range and reduced hardware utilization; thus, catering to the needs of portability. Furthermore, computations results at particular stage are rounded to avoid overflow issue and to be stored in register. The computation speed of the design is observed to be 50MHz after the synthesis process. Compared to traditional radix-4 algorithm the architecture proposed for 16-point FFT results in 1.73% of power saving and 5.5% of area reduction.

  12. An eye for inspiration

    Science.gov (United States)

    2009-11-01

    The discovery that the eye of a particular mantis shrimp has an achromatic quarter-waveplate that is superior to modern-day devices could be a source of inspiration to those designing optical components. Nature Photonics spoke to Nicholas Roberts, one of the researchers involved in the study.

  13. Hinkley Point 'C' power station public inquiry: proof of evidence on design and safety

    International Nuclear Information System (INIS)

    A public inquiry has been set up to examine the planning application made by the Central Electricity Generating Board (CEGB) for the construction of a 1200 MW Pressurized Water Reactor power station at Hinkley Point (Hinkley Point ''C'') in the United Kingdom. The policy is to replicate the Sizewell ''B'' PWR design. The Hinkley Point ''C'' design is described indicating where changes in the Sizewell ''B'' design have been made to accommodate site differences. These are associated with the civil engineering construction and some of the electrical systems and do not affect the safety case. External hazards differ from site to site and the effect on the safety case of those specific to Hinkley Point are examined. The Chernobyl accident and the assessment of the United Kingdom PWR which was carried out subsequently are reviewed. The assessment indicated that no changes in the Sizewell ''B'' design and safety case were called for as a result of this accident; accident management developments are also reviewed, however. The CEGB's approach to minimizing occupational radiation doses is described. (UK)

  14. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During Pregnancy Computer Usage & Eye Strain Maintaining Your Sight with ... Eye Protection Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Water & Contacts Don’ ...

  15. Animals Eyes

    Science.gov (United States)

    Sohmer, Rachel.

    2002-01-01

    The Web site from BioMedia (1) is a fascinating look (no pun intended) at the eyes of other animals. Various images of eyeballs link to essays that explain such questions as how animals can see underwater and how many times the eye independently evolved in the animal kingdom. The next site (2) is based on a PBS Nova documentary about nocturnal animals. Visitors can click on an image of an eye to learn more about the animal that uses it to see in the dark. The San Diego Natural History Museum provides the kid-friendly Web site, which does a terrific job of explaining the anatomy and function of different types of eyes (3). The next site, provided by Tufts University, offers photos of how squirrels, sharks, turtles, and bees might see the world compared with human vision (4). Andrew Giger, a neuroscientist working on bee vision at the Australian National University, wrote the program B-EYE for his research. Visitors to his Web site (5) can see what a selection of grey-scale images might look like from a bee's perspective. The next site (6) is provided by about.com, offering a detailed article about bird vision. Similarly, the next Web site from the North American Hunting Retriever Association contains an extensive review of an article that appeared in the Journal of the Veterinary Medical Association about dog vision (7). Finally, the last site is a page from Micscape - the online monthly magazine of Microscopy UK - showing how the eyes of various mollusks look under the microscope (8).

  16. Hollow Prosthetic Eyes.

    Science.gov (United States)

    Worrell, Emma

    2014-09-15

    A new technique to produce hollow prostheses is presented. A small case series of patients utilized standard methods to fabricate hollow ocular prostheses where rehabilitation had proved difficult. This article describes the fabrication and results of hollow ocular prostheses. Each hollow eye was significantly reduced in weight, one-third lighter than the original weight, with the exact size, shape, and volume of the existing solid prosthesis. This simple design significantly reduced the weight of these eyes and revolutionized these patients' rehabilitation. Previously the solid prostheses overburdened the lower eyelids, causing discomfort, irritation, discharge, and reddening, whereas the new lightweight prostheses are unobtrusive, comfortable, and good aesthetically. PMID:25226098

  17. Compact reversed-field pinch reactors (CRFPR): sensitivity study and design-point determination

    International Nuclear Information System (INIS)

    If the costing assumptions upon which the positive assessment of conventional large superconducting fusion reactors are based proves overly optimistic, approaches that promise considerably increased system power density and reduced mass utilization will be required. These more compact reactor embodiments generally must operate with reduced shield thickness and resistive magnets. Because of the unique, magnetic topology associated with the Reversed-Field Pinch (RFP), the compact reactor embodiment for this approach is particularly attractive from the viewpoint of low-field resistive coils operating with Ohmic losses that can be made small relative to the fusion power. A comprehensive system model is developed and described for a steady-state, compact RFP reactor (CRFPR). This model is used to select a unique cost-optimized design point that will be used for a conceptual engineering design. The cost-optimized CRFPR design presented herein would operate with system power densities and mass utilizations that are comparable to fission power plants and are an order of magnitude more favorable than the conventional approaches to magnetic fusion power. The sensitivity of the base-case design point to changes in plasma transport, profiles, beta, blanket thickness, normal vs superconducting coils, and fuel cycle (DT vs DD) is examined. The RFP approach is found to yield a point design for a high-power-density reactor that is surprisingly resilient to changes in key, but relatively unknown, physics and systems parameters

  18. The ARIES-I high-field-tokamak reactor: Design-point determination and parametric studies

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R.L.

    1989-01-01

    The multi-institutional ARIES study has examined the physics, technology, safety, and economic issues associated with the conceptual design of a tokamak magnetic-fusion reactor. The ARIES-I variant envisions a DT-fueled device based on advanced superconducting coil, blanket, and power-conversion technologies and a modest extrapolation of existing tokamak physics. A comprehensive systems and trade study has been conducted as an integral and ongoing part of the reactor assessment in order to identify an acceptable design point to be subjected to detailed analysis and integration as well as to characterize the ARIES-I operating space. Results of parametric studies leading to the identification of such a design point are presented. 15 refs., 6 figs., 2 tabs.

  19. Eye Problems in Radiologists

    Directory of Open Access Journals (Sweden)

    Morteza Tahmasebi

    2011-05-01

    Full Text Available In recent years, technologic advances (including the"nintroduction of MDCT coupled with an increasing"nnumber of unfilled radiology positions have led to an"nincreasing workload for radiologists. In fact radiologists"nworking under a heavy workload potentially face"na range of health issues, including musculoskeletal"ninjuries, eye strain and other problems. Eye strain is"na well-recognized consequence of computer overuse"nand it may be a particular issue for radiologists."nPosterior subcapsular cataract (PSC is common"namong interventional radiologists. Visual acuity is"neasily measured and corrected, but very little has"nbeen written regarding its importance to practicing"nradiologists. Eye strain is common in radiologists and"nit does not vary significantly between those using"nPACS and film. Improving the ergonomic design"nof workstations and modifying the work habits of"ncomputer users (with supplementary breaks have"nbeen shown to have positive effects on eye strain"nin these workers. Interventional radiologists are at"nhigh risk of radiation-induced eye injury and should"nconsider eye protection to avoid posterior subcapsular"n(PSC cataract formation. There is a progressive"nnormal deterioration in visual acuity with age which"nwill affect all radiologists, and in addition, there may"nbe an increased effect from the non-stochastic effect of"nionising radiation on the lens. According to abundance"nof eye problems related to over-use of computers in"nradiologists recognition and proper prevention of"nthem is necessary for radiologists.

  20. Eye and orbit ultrasound

    Science.gov (United States)

    Echography - eye orbit; Ultrasound - eye orbit; Ocular ultrasonography; Orbital ultrasonography ... eye is numbed with medicine (anesthetic drops). The ultrasound wand (transducer) is placed against the front surface ...

  1. From Takeoff to Landing: Looking at the Design Process for the Development of NASA Blast at Thanksgiving Point

    OpenAIRE

    Stephen Ashton; Foisy, Anne M.; Richard Marwedel; Aaron Popham, J.; Proctor, Keith R.; Randall, Daniel L.; Isaku Tateishi; Thompson, Carrie A.; Gibbons, Andrew S.

    2011-01-01

    In this article we discuss the process of design used to develop and design the NASA Blast exhibition at Thanksgiving Point, a museum complex in Lehi, Utah. This was a class project for the Advanced Instructional Design Class at Brigham Young University. In an attempt to create a new discourse (Krippendorff, 2006) for Thanksgiving Point visitors and staff members, the design class used a very fluid design approach by utilizing brainstorming, researching, class member personas, and prototyping...

  2. Web Design for Multiple Platforms in Microsoft SharePoint 2013

    OpenAIRE

    Claug, Erik

    2013-01-01

    As mobile devices become more common when surfing the web there is an increasing demand of making web sites adjusted to other devices than computers. One common platform on the web is Microsoft SharePoint. In this report I look into one method of how to develop web sites that work on multiple devices in Microsoft SharePoint. I will be looking into different techniques as separate web sites compared to responsive web design. By exploring the approach of mobile first I try to find a working sol...

  3. Planning proton therapy of the eye

    International Nuclear Information System (INIS)

    We describe a program for planning treatments of the eye with charged particle beams. Many of its features apply to treatment planning programs in general. These include the three-dimensional definition of the tumor volume and of normal structures, the possibility of delivering the treatment beam from any direction in space, the provision of arbitrary viewpoints including a ''beam's eye'' point of view, the design and fabrication of the field shaping aperture, the specification of the necessary beam quality (range and modulation), the calculation and display of isodose contours on any plane in space and on relevant surfaces, the identification of the extent to which normal structures are included or excluded from the beam, and the simulation of the desired alignment film with which patient alignment can be verified

  4. Planning proton therapy of the eye

    International Nuclear Information System (INIS)

    We describe a program for planning treatments of the eye with charged particle beams. Many of its features apply to treatment planning programs in general. These include the three-dimensional definition of the tumor volume and of normal structures, the possibility of delivering the treatment beam from any direction in space, the provision of arbitrary viewpoints including a ''beam's eye'' point of view, the design and fabrication of the field shaping aperture, the specification of the necessary beam quality (range and modulation), the calculation and display of isodose contours on any plane in space and on relevant surfaces, the identification of the extent to which normal structures are included or excluded from the beam, and the stimulation of the desired alignment film with which patient alignment can be verified

  5. What Is Dry Eye?

    Medline Plus

    Full Text Available Español Media Inquiries find an eye M.D. ask an eye M.D. Search GetEyeSmart.org Diseases & Conditions A to Z Age-related Macular Degeneration (AMD) Allergies Amblyopia (Lazy Eye) Astigmatism ...

  6. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... Topics Preventing Eye Injuries Healthy Eyes During Pregnancy Computer Usage & Eye Strain Maintaining Your Sight with Diabetes ... it. Give your Eyes a Break To prevent computer eyestrain, follow the 20-20-20 rule: Every ...

  7. Smoking and Eye Health

    Science.gov (United States)

    ... Eyes & the Sun Eye Health News Consumer Alerts Smoking and Eye Health Tweet Eye Health Lifestyle Topics ... vision may start to occur. Follow Us Avoiding smoking and second hand smoke—or quitting if you ...

  8. What Is Dry Eye?

    Science.gov (United States)

    ... Problems Medical Marijuana for Glaucoma Pregnancy Preventing Eye Injuries Smokers Sports Using Eye ... When you blink, a film of tears spreads over the eye, making the surface of the eye smooth and clear. Without this ...

  9. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Problems Medical Marijuana for Glaucoma Pregnancy Preventing Eye Injuries Smokers Sports Using Eye ... When you blink, a film of tears spreads over the eye, making the surface of the eye smooth and clear. Without this ...

  10. What Is Dry Eye?

    Medline Plus

    Full Text Available ... A to Z Age-related Macular Degeneration (AMD) Allergies Amblyopia (Lazy Eye) Astigmatism Bacterial Keratitis Bell's Palsy ... eyes? I have dry eyes—can zyrtec for allergies cause this? Is dry eye causing my severe ...

  11. National Eye Institute

    Science.gov (United States)

    ... eyes work, and more. Check out our resources Eye Health Infographics Use these graphics to share information ... science. Audacious Goals Translational Research eyeGENE® International Research Eye and Vision Research The latest on NEI research. ...

  12. Preventing Eye Injuries

    Science.gov (United States)

    ... the Sun Eye Health News Consumer Alerts Preventing Eye Injuries Tweet Protecting your eyes from injury is ... as possible, even if the injury seems minor. Eye Injury Facts and Myths Men are more likely ...

  13. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... Usage & Eye Strain Maintaining Your Sight with Diabetes Sports and Eye Protection Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Water & Contacts Don’ ...

  14. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Preventing Eye Injuries Smokers Sports Using Eye Makeup Veterans What Is an Ophthalmologist? Your Eyes & the Sun ... about eye health and preserving your vision. Privacy Policy Email address © 2015 American Academy of Ophthalmology medical ...

  15. Support points of locally optimal designs for nonlinear models with two parameters

    CERN Document Server

    Yang, Min; 10.1214/07-AOS560

    2009-01-01

    We propose a new approach for identifying the support points of a locally optimal design when the model is a nonlinear model. In contrast to the commonly used geometric approach, we use an approach based on algebraic tools. Considerations are restricted to models with two parameters, and the general results are applied to often used special cases, including logistic, probit, double exponential and double reciprocal models for binary data, a loglinear Poisson regression model for count data, and the Michaelis--Menten model. The approach, which is also of value for multi-stage experiments, works both with constrained and unconstrained design regions and is relatively easy to implement.

  16. Portable Amplifier Design for a Novel EEG Monitor in Point-of-Care Applications

    OpenAIRE

    Luan, Bo; Sun, Mingui; Jia, Wenyan

    2012-01-01

    The Electroencephalography (EEG) is a common diagnostic tool for neurological diseases and dysfunctions, such as epilepsy and insomnia. However, the current EEG technology cannot be utilized quickly and conveniently at the point of care due to the complex skin preparation procedures required and the inconvenient EEG data acquisition systems. This work presents a portable amplifier design that integrates a set of skin screw electrodes and a wireless data link. The battery-operated amplifier co...

  17. Design of a Novel Shape Signature by Farthest Point Angle for Object Recognition

    Directory of Open Access Journals (Sweden)

    M. Radhika Mani

    2014-12-01

    Full Text Available An overview of state of art in computerized object recognition techniques regarding digital images is revised. Advantages of shape based techniques are discussed. Importance of "Fourier Descriptor" (FD for the shape based object representation is described. A survey for the available shape signature assignment methods with Fourier descriptors is presented. Details for the design of shape signature containing the crucial information of corners of the object are depicted. A novel shape signature is designed basing on the Farthest Point Angle (FPA which corresponds to the contour point. FPA signature considers the computation of the angle between the line drawn from each contour point and the line drawn from the farthest corner point. Histogram for each 15o angle conceiving the information of the object is constructed. FPA signature is evaluated for three standard databases; viz., two in Kimia {K-99, K-216} and one in MPEG CE-1 Set B. The performance of the present FPA method estimated through recognition rate, time and degree of matching and is found to be higher.

  18. The Design Of Speech-Control Power Point Presentation Tool Using Arm7

    Directory of Open Access Journals (Sweden)

    P.Vishnu Kumar, Dr.T.JayaChandra Prasad

    2012-08-01

    Full Text Available This paper was mainly exploring the important tool for many people who were exchanging knowledge especially proceeding power-point presentation as one auxiliary tool. The lecturer’s most proper position should be between the audience and screen of power-point and this location is far away the mouse or keyboard and also if he want go for particular slide using mouse or keyboard is long process, so if we have designed one facility with wireless control and could be controlled with speech-recognition function so that users need not rush between the screen and computer and also he can easily go for particular slide. Today some identical products with RF [1] and push function on the power-point pen that needs users to pre-learn the functions and those usage often caused errors especially in the dark environment, so in this paper we combined WSN ZigBee modules [2] with speech-recognition function and ARM7 based LPC2148 microcontroller to design the creative product, so to called “Hi-TEC ZigBee remotecontroller of Power-Point presentation”.

  19. Eye Level

    Science.gov (United States)

    Eye level is an art blog written by a collaborative team at the Smithsonian American Art Museum (SAAM). According to the site, "... the conversation at Eye Level will be dedicated to American art and the ways in which the nation's art reflects its history and culture." The SAAM collection is meant as a foundation for the conversation on Eye Level. A recent post begins by talking about a road trip through the American West to see site-specific artwork, but at least one of the artists mentioned, Andrea Zittel, has a prior affiliation with SAAM. She was the 2005 Smithsonian Lucelia Artist Award winner, and the post links to prior entries on artwork at SAAM, both in and inspired by the American Southwest. These links were to works such as Robert Smithson's Spiral Jetty (an installation in the Great Salt Lake) and Albert Bierstadt's Among the Sierra Nevada, California, 1868. The February 1 post considers the future of art blogs, and the impact they may have on art criticism, museums, and the art world on the whole.

  20. Highly effective and accurate weak point monitoring method for advanced design rule (1x nm) devices

    Science.gov (United States)

    Ahn, Jeongho; Seong, ShiJin; Yoon, Minjung; Park, Il-Suk; Kim, HyungSeop; Ihm, Dongchul; Chin, Soobok; Sivaraman, Gangadharan; Li, Mingwei; Babulnath, Raghav; Lee, Chang Ho; Kurada, Satya; Brown, Christine; Galani, Rajiv; Kim, JaeHyun

    2014-04-01

    Historically when we used to manufacture semiconductor devices for 45 nm or above design rules, IC manufacturing yield was mainly determined by global random variations and therefore the chip manufacturers / manufacturing team were mainly responsible for yield improvement. With the introduction of sub-45 nm semiconductor technologies, yield started to be dominated by systematic variations, primarily centered on resolution problems, copper/low-k interconnects and CMP. These local systematic variations, which have become decisively greater than global random variations, are design-dependent [1, 2] and therefore designers now share the responsibility of increasing yield with manufacturers / manufacturing teams. A widening manufacturing gap has led to a dramatic increase in design rules that are either too restrictive or do not guarantee a litho/etch hotspot-free design. The semiconductor industry is currently limited to 193 nm scanners and no relief is expected from the equipment side to prevent / eliminate these systematic hotspots. Hence we have seen a lot of design houses coming up with innovative design products to check hotspots based on model based lithography checks to validate design manufacturability, which will also account for complex two-dimensional effects that stem from aggressive scaling of 193 nm lithography. Most of these hotspots (a.k.a., weak points) are especially seen on Back End of the Line (BEOL) process levels like Mx ADI, Mx Etch and Mx CMP. Inspecting some of these BEOL levels can be extremely challenging as there are lots of wafer noises or nuisances that can hinder an inspector's ability to detect and monitor the defects or weak points of interest. In this work we have attempted to accurately inspect the weak points using a novel broadband plasma optical inspection approach that enhances defect signal from patterns of interest (POI) and precisely suppresses surrounding wafer noises. This new approach is a paradigm shift in wafer inspection by leveraging systematic defect locations for high sensitivity inspection, thereby enhancing the discovery and monitoring of yield-limiting defects at traditional optical inspection throughput.

  1. General Didactics and Instructional Design: eyes like twins A transatlantic dialogue about similarities and differences, about the past and the future of two sciences of learning and teaching

    OpenAIRE

    Zierer, Klaus; Seel, Norbert M.

    2012-01-01

    Although General Didactics (GD) and Instructional Design (ID) have not shown many points of contact in the past, there are some obvious parellels from the perspective of their historical development. This will be examined in detail in this article. More specifically, we speak about model building, which has characterized General Didactics and Instructional Design for some decades. However, the models of General Didactics and Instructional Design are not problem-free with regard to the continu...

  2. Preliminary fly's eye results

    International Nuclear Information System (INIS)

    We describe an ultra-high energy physics observatory, the Fly's Eye, designed to measure extensive air showers (EAS) in the energy range 1017-1021eV via atmospheric fluorescence. Preliminary results are presented for the following measurements: (1) limits on the extragalactic neutrino flux at 1020eV, (2) the high energy cosmic ray spectrum, (3) sources of high energy cosmic rays, (4) the total proton cross section ?sub(pp)

  3. Technology development and circuit design for a parallel laser programmable floating point application specific processor

    Science.gov (United States)

    Scriber, Michael W.

    1989-12-01

    The laser programmable floating point application specific processor (LPASP) is a new approach at rapid development of custom VLSI chips. The LPASP is a generic application specific processor that can be programmed to perform a specific function. The effort of this thesis is to develop and test the double precision floating point adder and the laser programmable read-only memory (LPROM) that are macrocells within the LPASP. In addition, the applicability of an LPASP parallel processing system is analyzed. The double precision floating point adder is an adder/subtractor macrocell designed to comply with the IEEE double precision floating point standard. An 84-pin chip of the adder was fabricated using 2 micron feature sizes. The fastest processing time was measured at 120 nanoseconds over 23 worst case test vectors. The adder uses the optimized carry multiplexed (OCM) adder that was developed at AFIT. The OCM adder is a new adder architecture that uses four parallel carry paths to attain a performance time on the order of (cubed root of M) with a gate count on the order of O(n). The redundant logic associated with the parallel propagation banks is eliminated in the OCM adder so that the largest bit-slice of the adder contains only eight 2-to-1 multiplexer gates. A 57-bit adder was fabricated using 2 micron feature sizes. The processing time for the adder is 31 nsec.

  4. Design and Implementation of Floating Point Multiplier for Better Timing Performance

    Directory of Open Access Journals (Sweden)

    B.Sreenivasa Ganesh,J.E.N.Abhilash, G. Rajesh Kumar

    2012-09-01

    Full Text Available IEEE Standard 754 floating point is the most common representation today for real numbers on computers. This paper gives a brief overview of IEEE floating point and its representation. This paper describes a single precision floating point multiplier for better timing performance. The main object of this paper is to reduce the power consumption and to increase the speed of execution by implementing certain algorithm for multiplying two floating point numbers. In order to design this VHDL is the hardware description language is used and targeted on a Xilinx Spartan-3 FPGA. The implementation’s tradeoffs are area speed and accuracy. This multiplier also handles overflow and underflow cases. For high accuracy of the results normalization is also applied. By the use of pipelining process this multiplier is very good at speed and accuracy compared with the previous multipliers. This pipelined architecture is described in VHDL and is implemented on Xilinx Spartan 3 FPGA. Timing performance is measured with Xilinx Timing Analyzer. Timing performance is compared with standard multipliers.

  5. The individual virtual eye

    OpenAIRE

    Einighammer, Jens

    2008-01-01

    The individual virtual eye is a computer model of a human eye with respect to the optical properties. Established schematic eyes, as Gullstrand?s model eye, are intended to represent properties of an average eye based on averaged population measurements. In contrast, the individual virtual eye is based on measurements of an individual person. Therefore the geometry of the eye is important, including axial length and topographic measurements of the anterior corneal surface. All optical compon...

  6. Acupuncture for dry eye: a randomised controlled trial protocol

    Directory of Open Access Journals (Sweden)

    Kim Ae-Ran

    2009-12-01

    Full Text Available Abstract Background Dry eye is usually managed by conventional medical interventions such as artificial tears, anti-inflammatory drugs and surgical treatment. However, since dry eye is one of the most frequent ophthalmologic disorders, safer and more effective methods for its treatment are necessary, especially for vulnerable patients. Acupuncture has been widely used to treat patients with dry eye. Our aim is to evaluate the effectiveness and safety of acupuncture for this condition. Methods/Design A randomised, patient-assessor blinded, sham (non-acupuncture point, shallow acupuncture controlled study was established. Participants allocated to verum acupuncture and sham acupuncture groups will be treated three times weekly for three weeks for a total of nine sessions per participant. Seventeen points (GV23; bilateral BL2, GB4, TE23, Ex1 (Taiyang, ST1 and GB20; and left SP3, LU9, LU10 and HT8 for men, right for women have been selected for the verum acupuncture; for the sham acupuncture, points have been selected that do not coincide with a classical acupuncture point and that are located close to the verum points, except in the case of the rim of the eye. Ocular surface disease index, tear film breakup time, the Schirmer I test, medication quantification scale and general assessment of improvement will be used as outcome variables for evaluating the effectiveness of acupuncture. Safety will also be assessed at every visit. Primary and secondary outcomes will be assessed four weeks after screening. All statistical analyses will be performed using analysis of covariance. Discussion The results of this trial will be used as a basis for clarifying the efficacy of acupuncture for dry eye. Trial registration ClinicalTrials.gov NCT00969280.

  7. Optical performance of the eye with progressive addition lens correction

    OpenAIRE

    Barcik, A.; Siedlecki, Damian

    2010-01-01

    The aim of this study was to simulate the retinal image of the eye with progressive addition lens (PAL), correction (without cylindrical component) and investigate its quality. The optical design and analysis software was used in simulation. The topographical data of the front surface of PAL were taken from the scanning profilometry. Also the coordinates of the points of the distant and near power measurements were taken from topographical measurements. The back surface was assumed to be sphe...

  8. Critical Points of Contact : Exploring networked relations in urban mobility and service design

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Morelli, Nicola

    2011-01-01

    In contemporary urban societies multiple networks and systems interact, overlap, exist in parallel, converge, conflict etc. creating unforeseen complexity and less transparency. By exploring how layered networks of physical movement, service information, goods delivery, commercial communication etc. are connected (and disconnected) we get a much better understanding of how to design and intervene regardless if we are thinking about public spaces in the city or new systems of service design. The many networks orchestrating and facilitating contemporary everyday life are dependent on the strategic sites where the networks meet and establish contact. Thus we argue for the usefulness of the notion of Critical Point of Contact (CPC) to deepen our understanding of the actual life within networks. En route to this notion we draw upon theories within as diverse realms such as interaction design, service design, geography, and mobility studies. After the introduction in section we develop and define the notion of CPC based upon a broad set of disciplines and theories. We illustrate the usefulness of the notion within the field of mobility in the network city and within the field of service design. The paper ends with concluding remarks and perspectives for further theoretical as well as empirical work in prolongation of this beginning research effort.

  9. Childhood Eye Diseases and Conditions

    Science.gov (United States)

    ... the Sun Eye Health News Consumer Alerts Childhood Eye Diseases and Conditions Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes ... over the battery and always wear safety goggles. Eye Protection Works Wearing the proper protective eyewear for ...

  10. A Most Probable Point-Based Method for Reliability Analysis, Sensitivity Analysis and Design Optimization

    Science.gov (United States)

    Hou, Gene J.-W.; Gumbert, Clyde R.; Newman, Perry A.

    2004-01-01

    A major step in a most probable point (MPP)-based method for reliability analysis is to determine the MPP. This is usually accomplished by using an optimization search algorithm. The optimal solutions associated with the MPP provide measurements related to safety probability. This study focuses on two commonly used approximate probability integration methods; i.e., the Reliability Index Approach (RIA) and the Performance Measurement Approach (PMA). Their reliability sensitivity equations are first derived in this paper, based on the derivatives of their respective optimal solutions. Examples are then provided to demonstrate the use of these derivatives for better reliability analysis and Reliability-Based Design Optimization (RBDO).

  11. Optimal futility interim design: a predictive probability of success approach with time to event end point.

    Science.gov (United States)

    Tang, Zhongwen

    2014-11-01

    Abstract An analytical way to compute predictive probability of success (PPOS) together with credible interval at interim analysis (IA) is developed for big clinical trials with time to event end points. The method takes account of the fixed data up to IA, the amount of uncertainty in future data, and uncertainty about parameters. Predictive power is a special type of PPOS. The result is confirmed by simulation. An optimal design is proposed by finding optimal combination of analysis time and futility cutoff based on some PPOS criteria. PMID:25379701

  12. Observer-based design of set-point tracking adaptive controllers for nonlinear chaotic systems

    International Nuclear Information System (INIS)

    A gradient based approach for the design of set-point tracking adaptive controllers for nonlinear chaotic systems is presented. In this approach, Lyapunov exponents are used to select the controller gain. In the case of unknown or time varying chaotic plants, the Lyapunov exponents may vary during the plant operation. In this paper, an effective adaptive strategy is used for online identification of Lyapunov exponents and adaptive control of nonlinear chaotic plants. Also, a nonlinear observer for estimation of the states is proposed. Simulation results are provided to show the effectiveness of the proposed methodology

  13. A ground control points sampling design method based on smallest singular value

    Science.gov (United States)

    Wang, Pu; An, Wei; Deng, Xing Pu; Guo, Jing; Li, Jun

    2014-10-01

    The Ground Control Points (GCPs) are widely used in geometric correction for remote sensing imagery, and the distribution of them is a key factor which affects the accuracy and quality of image correction. In this paper, we propose a new sampling design method, called Smallest Singular Value-based Sampling (SSVS), to obtain the optimal distribution of the GCPs. When the geometric correction of remote sensing imagery is performed with a 2D or 3D polynomial function model, the estimation of geometric correction model parameters can be interpreted as an estimation of regression coefficients with a Multiple Linear Regression(MLR) model, whose design matrix depends on the coordinates of GCPs. From the perspective of regression model, the design matrix of MLR should be optimized to obtain the most accurate regression coefficients. In this paper, it has been proved that the Smallest Singular Value(SSV) of design matrix is inversely proportional to the upper bound of estimation errors. By choosing the optimal distribution of GCPs, the SSV of design matrix can be maximized and the upper bound of estimation errors can be minimized. Therefore, the SSV of design matrix is used as a criterion, and the objective of SSVS is to find the sample pattern that has the biggest SSV. In this paper, the simulation annealing is employed to search the optimal pattern. Two experiments were carried out to test SSVS. The results indicate that the SSVS is an effective GCPs sampling design method and can be applied to evaluate upper bound of estimation error.

  14. Theory and design of line-to-point focus solar concentrators with tracking secondary optics.

    Science.gov (United States)

    Cooper, Thomas; Ambrosetti, Gianluca; Pedretti, Andrea; Steinfeld, Aldo

    2013-12-10

    The two-stage line-to-point focus solar concentrator with tracking secondary optics is introduced. Its design aims to reduce the cost per m(2) of collecting aperture by maintaining a one-axis tracking trough as the primary concentrator, while allowing the thermodynamic limit of concentration in 2D of 215× to be significantly surpassed by the implementation of a tracking secondary stage. The limits of overall geometric concentration are found to exceed 4000× when hollow secondary concentrators are used, and 6000× when the receiver is immersed in a dielectric material of refractive index n=1.5. Three exemplary collectors, with geometric concentrations in the range of 500-1500× are explored and their geometric performance is ascertained by Monte Carlo ray-tracing. The proposed solar concentrator design is well-suited for large-scale applications with discrete, flat receivers requiring concentration ratios in the range 500-2000×. PMID:24513906

  15. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... Eye Protection Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Water & Contacts Don’t Mix To help prevent ... 0:50 Free Newsletter Get eye MD-reviewed tips and information about eye health and preserving your vision. Privacy Policy Email address

  16. What Is Dry Eye?

    Medline Plus

    Full Text Available ... large volume of tears, overwhelming the tear drainage system. These excess tears then overflow from your eye. Next Page: Causes of Dry ... Do For Their Eyes - Eye M.D.-approved information from EyeSmart Travel Tips For Your Eyes Only - ...

  17. Design and Development of Intracavity Optical Parametric Oscillator-based Eye Safe Laser Operating at 20 Hz without Forced Air Cooling

    Directory of Open Access Journals (Sweden)

    Atul Bhardwaj

    2013-12-01

    Full Text Available In this paper we report the design and development of an electro-optically Q-switched diode pumped Nd:YAG laser with intracavity optical parametric oscillator, generating ~ 5 ns laser pulses of ~8 mJ energy at eye safe wavelength of 1534 nm. A Z-shaped laser resonator has been designed with porro prism end reflector in Q-switch arm containing RTP Q-Switch and a suitably oriented waveplate. The gain arm consists of a Ø3 x 72 mm Nd: YAG laser rod, pumped from one side by 3 x 5 bar laser diode array stack emitting total optical peak power of 740 W at 804 nm at 38 °C. Thermoelectric coolers (TECs have been employed to maintain the optimum temperature of laser diode arrays and the combined heat load from the pump chamber and TECs is distributed over the system base plate with embedded heat pipes. Such cooling mechanism has eliminated the requirement of fins and fans in the laser system. Eye safe radiation is out-coupled through intra cavity KTA OPO (5 x 5 x 20 mm3 placed in the gain arm. Laser was operated at 20 Hz for several duty cycles of 10 min on and 10 min off and output energy remained stable within ±0.5 mJ without any forced air/liquid cooling.Defence Science Journal, 2013, 63(6, pp.599-605, DOI:http://dx.doi.org/10.14429/dsj.63.5759

  18. Design and construction of equipment for point-source, low energy electron microdosimetry measurements

    International Nuclear Information System (INIS)

    Actual measurements of dose as a function of distance for point-source, discrete energy spectra are essential to the selection of radionuclides for radioimmunotherapy, as the present theoretical basis provides extrapolations into the low energy region where assumptions about the energy-loss mechanisms are believed to break down. The authors present a discussion of design criteria for an apparatus aimed at measuring dose in gases for low energy (10 to 100 keV) electron sources, as well as description of the equipment that emerged from this analysis. Given the short ranges involved, an almost-wall-less ionization chamber with cylindrical symmetry was selected. The chamber is fixed in position and a radioactive point-source is moved along its axis by remote control, preventing air disturbances in the chamber while obtaining ionization current measurements. A laser-aided positioning mechanism maintains alignment of the axis within 0.5 mm, and chamber-to-source distance is known within 0.3 mm. Special attention was given to the open-air ionization chamber design, and two different models were built. Guarding, grounding, and insulating schemes are proposed. The apparatus can be easily modified for use with gases other than air. This equipment is presently being used to provide data for validation of, or corrections to, available theoretical calculations

  19. Designing DOKK1 from a child’s point of view

    DEFF Research Database (Denmark)

    Geert Jensen, Birgitte; Borup Lynggaard, Aviaja

    Designing DOKK1 from a child’s point of view By Aviaja Borup Lynggaard & Birgitte Geert Jensen This poster presents a design case of collaborative innovation between design students from Aarhus School of Architecture and pupils from the public school, Samsøgades School in Aarhus, facilitated by the research project Kids n’Tweens Lifestyle. The scope of collaborating was to design the content for DOKK1, the new Mediaspace center in Aarhus, where design students took offset from the children’s world in a creative workshop as inspiration for the final design proposals. The task was carried out in collaboration with the working group on the new Dokk1 and the goal was to create a library that makes sense for the whole family. Some of the questions that the students wanted to answer was: • How can you create a library where there are joint activities that makes sense for the whole family? • How to create fun for families in the library? • How can play help to promote interaction and communication? The students worked with the space in Dokk1 as the “third place”, which is identified by Oldenburg (1999) as “great good places”, being public places on neutral ground where people can gather and interact. The cooperative design workshop led to a range of insights and inspiration for the students to implement in their design solutions. An issue that the workshop revealed concerned a variety of interests and requirements when designing across ages. The age difference between users calls for variations in the use of space and design. The workshop also showed that the “third place” is achieved today in existing places around the city, such as in shops and banks. Therefore, several of the solutions showed that there is need to create a residence that can accommodate the versatility and give space for user participation. The workshop was facilitated by Kids n’Tweens Lifestyle, as part of method development when engaging children in the design process. 8 groups were formed and a range of creative methods was tested. The methods varied from: Model making, lego prototyping, mood boards/blocks, inspirational pictures, future scenarios (library in 500 years), thinking out loud, body storming and sketching. The outcome led to new insights about the end users and an ideacatalogue for the students to elaborate from. The poster will present two design results – “Bookscape” and “Tumble”. Bookscape took offset from the children’s aspiration to create small and private spaces, as the shelves can be moved and thus act as space makers. The storage of the books provides a platform where new activities can take place. Tumble took offset from the pupils’ request towards being able to perform multiple activities in DOKK1. This led to the design of transformative furniture that can be rolled around on 4 different edges that each enables different activities. We presented an innovative collaboration between design students and pupils from a public school. A creative workshop led to manifold projects, where two are presented in this poster to exemplify how the inputs from children can feed a creative design process.

  20. Bionic Eyes

    Science.gov (United States)

    Phillips, Tony.

    2002-01-01

    Both Web sites come from Science@NASA, an online source for news and information about NASA-funded research. The first article describes the work of researchers at the Center for Commercial Applications of Combustion in Space, who are developing artificial bones for long-lasting, pain-free hip and knee replacements. These ceramic bones are touted as "so much like the real thing that they could actually meld with living bone." Earlier this year, researchers at the Space Vacuum Epitaxy Center in Houston experimented with "photosensitive ceramic films that respond to light much as rods and cones do," the subject of the second Web site. Researchers hope these films will eventually be used to restore lost vision in human eyes. Each article is available as an audio file, and includes helpful diagrams and Web links for related articles and information.

  1. What Is Dry Eye?

    Medline Plus

    Full Text Available ... excess tears then overflow from your eye. Next Page: Causes of Dry Eye Written by Kierstan Boyd ... pain? Can Vectibix (a drug used to treat cancer) cause keratitis of the eye? Is there a ...

  2. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Free Newsletter Get eye MD-reviewed tips and information about eye health and preserving your vision. Privacy Policy Email address ... Resources EyeWiki contact us sitemap Reproducing text or images from this ...

  3. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... going swimming or in a hot tub. Jumping a Battery Take precautions to prevent eye injury. Never ... of eye injuries. It's Not OK to Skip a Day To control glaucoma, take eye drops exactly ...

  4. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Is Dry Eye? Tweet When you blink, a film of tears spreads over the eye, making the ... the eye smooth and clear. Without this tear film, good vision would not be possible. What Is ...

  5. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... Sports and Eye Protection Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Water & ... Enter your question here... Browse Top Answers > Privacy Policy > Featured Video LASIK (Femtosecond) 0:50 Free Newsletter ...

  6. Design of Neutral-Point Voltage Controller of a Three-level NPC Inverter with Small DC-Link Capacitors

    DEFF Research Database (Denmark)

    Maheshwari, Ram Krishan; Munk-Nielsen, Stig

    2013-01-01

    A Neutral-Point-Clamped (NPC) three-level inverter with small dc-link capacitors is presented in this paper. The inverter requires zero average neutral-point current for stable neutral-point voltage. The small dc-link capacitors may not maintain capacitor voltage balance, even with zero neutral-point current. This may happen due to nonlinearities present in the circuit. This requires a fast control of the neutral-point voltage. A simple carrier based modulation strategy which allows modeling of the neutral-point voltage dynamics as a continuous function of power drawn from the inverter is proposed. This continuous model shows that the neutral-point current is proportional to the power drawn from the inverter, and it enables the use of well established classical control theory for the neutral-point voltage controller design. A simple PI (proportional integral) controller is designed for the neutral-point voltage control on the basis of the continuous model. The design method for optimum performance is discussed. The implementation of the proposed modulation strategy and the controller is very simple. The controller is implemented in a 7.5 kW induction machine based drive with only 14 ìF dc-link capacitors. Also, the experimental results show that fast and stable performance of the neutral-point voltage controller are achieved and thus verify the validity of the proposed control approach.

  7. Experimental Investigation of a Point Design Optimized Arrow Wing HSCT Configuration

    Science.gov (United States)

    Narducci, Robert P.; Sundaram, P.; Agrawal, Shreekant; Cheung, S.; Arslan, A. E.; Martin, G. L.

    1999-01-01

    The M2.4-7A Arrow Wing HSCT configuration was optimized for straight and level cruise at a Mach number of 2.4 and a lift coefficient of 0.10. A quasi-Newton optimization scheme maximized the lift-to-drag ratio (by minimizing drag-to-lift) using Euler solutions from FL067 to estimate the lift and drag forces. A 1.675% wind-tunnel model of the Opt5 HSCT configuration was built to validate the design methodology. Experimental data gathered at the NASA Langley Unitary Plan Wind Tunnel (UPWT) section #2 facility verified CFL3D Euler and Navier-Stokes predictions of the Opt5 performance at the design point. In turn, CFL3D confirmed the improvement in the lift-to-drag ratio obtained during the optimization, thus validating the design procedure. A data base at off-design conditions was obtained during three wind-tunnel tests. The entry into NASA Langley UPWT section #2 obtained data at a free stream Mach number, M(sub infinity), of 2.55 as well as the design Mach number, M(sub infinity)=2.4. Data from a Mach number range of 1.8 to 2.4 was taken at UPWT section #1. Transonic and low supersonic Mach numbers, M(sub infinity)=0.6 to 1.2, was gathered at the NASA Langley 16 ft. Transonic Wind Tunnel (TWT). In addition to good agreement between CFD and experimental data, highlights from the wind-tunnel tests include a trip dot study suggesting a linear relationship between trip dot drag and Mach number, an aeroelastic study that measured the outboard wing deflection and twist, and a flap scheduling study that identifies the possibility of only one leading-edge and trailing-edge flap setting for transonic cruise and another for low supersonic acceleration.

  8. From Takeoff to Landing: Looking at the Design Process for the Development of NASA Blast at Thanksgiving Point

    Directory of Open Access Journals (Sweden)

    Stephen Ashton

    2011-01-01

    Full Text Available In this article we discuss the process of design used to develop and design the NASA Blast exhibition at Thanksgiving Point, a museum complex in Lehi, Utah. This was a class project for the Advanced Instructional Design Class at Brigham Young University. In an attempt to create a new discourse (Krippendorff, 2006 for Thanksgiving Point visitors and staff members, the design class used a very fluid design approach by utilizing brainstorming, researching, class member personas, and prototyping to create ideas for the new exhibition. Because of the nature of the experience, the design class developed their own techniques to enhance the process of their design. The result of the design was a compelling narrative that brought all the elements of the exhibition together in a cohesive piece.

  9. Performance comparison of liquid metal and gas cooled ATW system point designs

    International Nuclear Information System (INIS)

    As part of the Advanced Accelerator Application (AAA) program in the U.S., preliminary design studies have been performed at Argonne National Laboratory (ANL) and Los Alamos National Laboratory (LANL) to define and compare candidate Accelerator Transmutation of Waste (ATW) systems. The studies at ANL have focused primarily on the transmutation blanket component of the overall system. Lead-bismuth eutectic (LBE), sodium, and gas cooled systems are among the blanket technology options currently under consideration. This paper summarizes the results from neutronics trade studies performed at ANL. Core designs have been developed for LBE and sodium cooled 840 MWt fast spectrum accelerator driven systems employing re-cycle. Additionally, neutronics analyses have been performed for a helium-cooled 600 MWt hybrid thermal and fast spectrum system proposed by General Atomics (GA), which is operated in the critical mode for three cycles and in a subcritical accelerator driven mode for a subsequent single cycle. For these three point designs, isotopic inventories, consumption rates, and annual burnup rates are compared. The mass flows and the ultimate loss of transuranic (TRU) isotopes to the waste stream per unit of heat generated during transmutation are also compared on a consistent basis. (author)

  10. An experimental study on a training support system utilizing trainee's eye gaze point and think aloud protocol for diagnosing nuclear power plant anomalies

    International Nuclear Information System (INIS)

    An experimental system has been developed for aiming at supporting the simulator training of diagnosis nuclear power plant anomaly, where an expert provides the instructions to a trainee by his/her own educational and experienced point of view. This system has several characteristics as follows: (1) the expert can provide the instruction through the local area network or the Internet, (2) the training task is the detection of the primary cause of plant anomaly, which is not including the plant operation but requires only thinking, and (3) the system can automatically detects the trainee's view-point and think aloud protocols and provide these two types of information to the expert in real time for supporting his/her instruction. A laboratory experiment using this system was conducted, where an expert, who had really engaged in plant operation as a chief operator, was employed as the instructor for novice students. As the result of analyzing the experimental data, it was found that the two types of information, trainee's viewpoints and his verbal protocols, have some potential of effectiveness for supporting the instructor to estimate the trainees diagnostic thinking process and provide the instruction. (author)

  11. Interaction point feedback design and integrated simulations to stabilize the CLIC final focus

    CERN Document Server

    Balik, G; Deleglise, G; Jeremie, A; Pacquet, L; Badel, A; Caron, B; Le Breton, R; Latina, A; Pfingstner, J; Schulte, D; Snuverink, J

    2011-01-01

    The Compact Linear Collider (CLIC) accelerator has strong precision requirements on the offset position between the beams. Sensitive to ground motion (GM), the beam needs to be stabilized to unprecedented requirements. Different Beam Based Feedback (BBF) algorithms such as Orbit Feedback (OFB) and Interaction Point Feedback (IPFB) have been designed. This paper focuses on the IPFB control which could be added to the CLIC baseline. IPFB control has been tested for different GM models in presence of noises or disturbances and it uses digital linear control with an adaptive loop. The simulations demonstrate that it is possible to achieve the required performances and quantify the maximum allowed noise level. This amount of admitted noises and disturbances is given in terms of an equivalent disturbance on the position of the magnet that controls the beam offset. Due to the limited sampling frequency of the process, the control loop is in a very small bandwidth. The study shows that these disturbances have to be l...

  12. Design of the Point Absorber Wave Energy Converter for Assaluyeh Port

    Directory of Open Access Journals (Sweden)

    Mehdi Nazari

    2013-01-01

    Full Text Available The research explained in this paper was carried out to analyze and design a point absorber waveenergy convertor for Assaluyeh coastal on Persian Gulf. The geographical conditions of this region have some local short waves which may be ideal to use this type of energy convertor. According to the collecting of wave data and using an optimized buoy, it is concluded that the adjustments on damping and natural frequency have more effect on average heave displacement. Therefore, by changing the shape of flat buoy to conical cylindrical, the drag coefficient that has direct effect on the damping of the buoy could be reduced. Regarding the length to diameter ratio of 1.7 for the selected buoy, changing its shape from flat cylinder to conical cylinder causes the drag coefficient to decrease by 50 %, which is followed by 20% increase in average amplitude of heave motion from

  13. Design of multi-point automatic positioning pre-programmed crane control system

    International Nuclear Information System (INIS)

    This automatic positioning system is designed for the crane which is in common use. The crane hall is cut into several parts, the position is detected by the photoelectric switches, and the PLC and inverter are used for the control devices. The automatic positioning control of the crane is completed by means of the timing movement. The positioning error is less than 2.1 cm, the swing range when lifting object is less than 5.7 cm, and the average speed of the crane is more than 90% of the rated speed. This paper gives further description in the positioning control, direction control, speed control and the identification of the starting point. Finally it gives an analysis of the automatic positioning performance. (authors)

  14. A typical pointed observation in IRAS designed to fit into a 15 minute window

    Science.gov (United States)

    Neugebauer, G.; Gregorich, D.

    1993-01-01

    A typical pointed observation in the Infrared Astronomical Satellite (IRAS) was designed to fit into a 15 minute window. Observing constraints, however, did not always permit targets from the scientific program to be observed on exactly 15 minute centers and a few months into the mission it was realized that the automatic scheduling program left times when no observations were being made. In order to use this potentially wasted observing time, a mode of pointed observations, the 'filler' mode, with shorter observation duration was initiated. Locations were picked on an arbitrary grid, spaced relatively uniformly in ecliptic coordinates, and the telescope was pointed to one of these sites whenever a gap potentially occurred. One of us (GXN) was the coordinator of this effort (the FL sub-group). There are a total of 22 FL fields, 13 of which have more than 50 component observations. These 13 fields cover about 30 square degrees. It was proposed to concentrate on one filler field, FL29, a field with 53 coverages which thus had among the deepest coverage of those observed in this mode. This field was also observed extensively at various non-infrared wavelengths by a variety of techniques. Because the IRAS observations of FL29 were made at the limits of the survey sensitivity and at different twist angles it was necessary to make significant technical advances in the methods used in the processing and analyzing the data. In particular, if normal IRAS coaddition procedures were used, the noise resulting from coaddition of the multiple frames did not decrease in the manner expected once significantly different twist angles were included in the coaddition. The technical effort needed to reduce the observations of FL29 was completed and now the noise behavior is understood and well behaved. The reduction of the field FL29 observations is done.

  15. Mission design and analysis of European astrophysics missions orbiting libration points

    Science.gov (United States)

    Landgraf, Markus; Renk, Florian; de Vogeleer, Bram

    2013-03-01

    The main characteristics of the trajectory design of space observatory missions in the Earth-Sun libration point region is highlighted, based on experiences gained in work performed by the authors on ESA missions. Free transfers always lead to large-amplitude orbits around L2, their properties (amplitudes, phases, non-linear behaviour) are related to the conditions at perigee. Launch scenarios with different degrees of freedom in the perigee geometry and different strategies of sharing the apogee raising between launcher and spacecraft propulsion for Soyuz (with circular parking orbit or direct injection) and Ariane 5 launches from French Guiana will be discussed. Besides the orbit selection and transfer analysis, an important aspect of libration missions is the maintenance of the operational orbit. For some missions it is required to maximise the time between maintenance manoeuvres, and for some the thrust authority is limited. In both cases the exponential nature of the state transition matrix has to be considered. If the equivalent velocity error in the unstable direction becomes too large, the orbit can become unrecoverable, leading to a departure from the environment of the Lagrange point within a few months.

  16. Design, Results, Evolution and Status of the ATLAS simulation in Point1 project.

    CERN Document Server

    Ballestrero, Sergio; The ATLAS collaboration; Brasolin, Franco; Contescu, Alexandru Cristian; Fazio, Daniel; Di Girolamo, Alessandro; Lee, Christopher Jon; Pozo Astigarraga, Mikel Eukeni; Scannicchio, Diana; Sedov, Alexey; Twomey, Matthew Shaun; Wang, Fuquan; Zaytsev, Alexander

    2015-01-01

    During the LHC long shutdown period (LS1), that started in 2013, the simulation in Point1 (Sim@P1) project takes advantage in an opportunistic way of the trigger and data acquisition (TDAQ) farm of the ATLAS experiment. The farm provides more than 1500 computer nodes, and they are particularly suitable for running event generation and Monte Carlo production jobs that are mostly CPU and not I/O bound. It is capable of running up to 2500 virtual machines (VM) provided with 8 CPU cores each, for a total of up to 20000 parallel running jobs. This contribution gives a thorough review of the design, the results and the evolution of the Sim@P1 project operating a large scale Openstack based virtualized platform deployed on top of the ATLAS TDAQ farm computing resources. During LS1, Sim@P1 was one of the most productive GRID sites: it delivered more than 50 million CPU-hours and it generated more than 1.7 billion Monte Carlo events to various analysis communities within the ATLAS collaboration. The particular design ...

  17. Anthropogenic point and area source CO2 plume measurements: Implications for spaceborne CO2 sensor design

    Science.gov (United States)

    Andrews, A. E.; Ryerson, T. B.; Peischl, J.; Parrish, D. D.; Trainer, M.; Tans, P. P.

    2011-12-01

    Anthropogenic point and area source CO2 plume measurements: Implications for spaceborne CO2 sensor design A. Andrews, T. Ryerson, J. Peischl, D. Parrish, M. Trainer, P. Tans An extensive dataset of CO2 concentrations including enhancements in point and area source plumes is available from in situ measurements collected using the NOAA P-3 and NCAR Electra research aircraft during seven major field projects from 1999 through 2010. Research flights sampled emission plumes from coal-, oil-, and natural gas-fired electric utility power plants, industrial facilities, and urban areas. Plume sampling often included horizontal transects at several altitudes and multiple distances downwind. CO2 data from crosswind transects upwind and downwind, coupled with ancillary measurements of co-emitted nitric oxide, nitrogen dioxide and sulfur dioxide, along with plume location, and wind speed and direction permit unambiguous attribution and quantification of atmospheric plumes from individual sources. Certain point sources were revisited on multiple flights over the course of 1-2 month long field projects and on successive field projects spanning several years. Sampling occurred primarily in the summertime, daytime continental boundary layer, with some plume studies performed after dark and in the spring, fall, and winter seasons. The data provide rigorously calibrated, measurement-based constraints on the expected range of atmospheric CO2 plume enhancements that can be used to assess satellite sensor concepts. Crosswind near-field (~5 km) transects in the summer daytime mixed-layer downwind of the strongest point sources were characterized by peak plume CO2 mixing ratio enhancements >100 ppm above background for the 100-m spatial averages reported from the moving aircraft. On many flights, the aircraft tracked such emissions plumes beyond 150 km downwind, or up to 10 hours of transport time, until plume enhancements were indistinguishable from background variability in CO2. Conversely, summertime CO2 enhancements in the daytime mixed layer immediately above and downwind of urban areas rarely exceeded 10 ppm and became indistinguishable from the background within ~50 km downwind, or ~1-2 hours of transport time. We use a Gaussian plume model, constrained by the airborne data, to construct three-dimensional CO2 fields that can be sampled with idealized vertical weighting functions and realistic footprints and ground-tracks corresponding to a variety of existing and planned satellite sensors. These CO2 fields are used to explore to what extent and under what conditions anthropogenic CO2 emission rates can be reliably inferred from synthetic satellite observations.

  18. Eye safe laser range finders

    International Nuclear Information System (INIS)

    During the 1970's, Ruby (Q switched) laser based range finders with a wavelength of 694nm were first used. These lasers operated in a pulse mode within the visible light range and produced a risk for the eye retina. The laser beam striking the macula could damage the eye and might cause blindness. Over the years, Nd:YAG (Q switched) lasers were developed (operating at 1064nm) for range finding and designation uses. The wavelength of these lasers, operating in the near Infra-Red range (invisible), is also focused tightly on the retina. The human eye does not respond to the invisible light so there is no natural protection (eye blink reflex) as in the visible light. The operation of these lasers worldwide, especially when the laser beam is exposed, causes occasional eye accidents. Another risk is stemming from the use of observation systems with a high optical gain, in the laser operation areas, which enlarge the range of risk quite significantly. Therefore, research and development efforts were invested in order to introduce eye safe lasers. One of the solutions for this problem is presented in following document

  19. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Water & Contacts Don’t Mix To help prevent eye ... Eye M.D. the benefits and risks — including quality of life issues — that could result from correcting ...

  20. What Is Dry Eye?

    Medline Plus

    Full Text Available Español Media Inquiries find an eye M.D. ask an eye M.D. Search GetEyeSmart.org Diseases & Conditions A to Z Age-related Macular Degeneration (AMD) Allergies Amblyopia (Lazy Eye) Astigmatism Bacterial Keratitis Bell's Palsy Blepharitis Cataracts Contact Lens- ...

  1. Design of Multi-point Wireless Temperature and Humidity Sensor Network Based on NRF24l01

    OpenAIRE

    Jin Gang; Fan Wen-qiang; He Peng-fei; Liu Yun-xue

    2013-01-01

    Many fields need to use the multi-point data acquisition and transmission system to overcome the weakness of wired data transmission system. Based on the single chip transceiver nRF24L01 and favorite microprocessor STM32F107, designed the multi-point wireless sensor network. The system used the 1-wire temperature and humidity sensor DHT22 as Data acquisition components. The paper studied the hardware construction and the software design in details. Designed the circuit diagram, made the PCB p...

  2. EyeC3D: 3D video eye tracking dataset

    OpenAIRE

    Hanhart, Philippe; Ebrahimi, Touradj

    2014-01-01

    Despite efforts of the scientific community in recent years, little is known about the mechanisms of the human visual system that control visual attention when watching 3D content. To help understanding these mechanisms and develop more accurate visual attention models, we created a public 3D video eye tracking dataset. The dataset provides the eye tracking information corresponding to eight stereoscopic video sequences. The eye tracking information includes the fixation points and fixation d...

  3. Hand-Eye Calibration Using Active Vision

    Science.gov (United States)

    Nickels, Kevin; Huber, Eric; DiCicco, Matthew

    2007-01-01

    The project described in this paper designed and implemented a hand-eye calibration method for manipulators under observation by stereo cameras. This method has been utilized on Johnson Space Center's Robonaut, and on a planetary manipulator mock-up at the Jet Propulsion Laboratory. The intent of this calibration is to improve the manipulator's hand-eye coordination.

  4. Recognizing and Treating Eye Injuries

    Science.gov (United States)

    ... Screening Guidelines Home Remedies for Simple Eye Problems Medical Marijuana for Glaucoma Pregnancy Preventing Eye Injuries Smokers Sports Using Eye Makeup Veterans What Is an Ophthalmologist? Your Eyes & the Sun Eye Health News Consumer Alerts ... an eye injury does occur, have an ophthalmologist or other medical doctor examine the eye as soon as possible, ...

  5. Lenses matching of compound eye for target positioning

    Science.gov (United States)

    Guo, Fang; Zheng, Yan Pei; Wang, Keyi

    2012-10-01

    Compound eye, as a new imaging method with multi-lens for a large field of view, could complete target positioning and detection fastly, especially at close range. Therefore it could be applicated in the fields of military and medical treatment and aviation with vast market potential and development prospect. Yet the compound eye imaging method designed use three layer construction of multiple lens array arranged in a curved surface and refractive lens and imaging sensor of CMOS. In order to simplify process structure and increase the imaging area of every sub-eye, the imaging area of every eye is coved with the whole CMOS. Therefore, for several imaging point of one target, the corresponding lens of every imaging point is unkonown, and thus to identify. So an algorithm was put forward. Firstly, according to the Regular Geometry relationship of several adjacent lenses, data organization of seven lenses with a main lens was built. Subsequently, by the data organization, when one target was caught by several unknown lenses, we search every combined type of the received lenses. And for every combined type, two lenses were selected to combine and were used to calculate one three-dimensional (3D) coordinate of the target. If the 3D coordinates are same to the some combine type of the lenses numbers, in theory, the lenses and the imaging points are matched. So according to error of the 3D coordinates is calculated by the different seven lenses numbers combines, the unknown lenses could be distinguished. The experimental results show that the presented algorithm is feasible and can complete matching task for imaging points and corresponding lenses.

  6. Comparative outcomes of manual small incision cataract surgery and phacoemulsification performed by ophthalmology trainees in a tertiary eye care hospital in India: a retrospective cohort design

    Science.gov (United States)

    Khanna, Rohit C; Kaza, Srivalli; Palamaner Subash Shantha, Ghanshyam; Sangwan, Virender S

    2012-01-01

    Objective To compare the outcomes of manual small incision cataract surgery (MSICS) and phacoemulsification performed by ophthalmology trainees. Design Retrospective cohort design. Setting Tertiary eye care centre. Participants A total of 1029 subjects underwent cataract surgeries with MSICS technique or phacoemulsification by trainees during one quarter (July–September 2007). Only 484 (47%) subjects were males. Surgeries which were primarily large incision extracapsular or intracapsular cataract extraction and performed on patients less than 20?years of age were excluded. Outcome measures The postoperative best corrected visual acuity (BCVA) along with the rates and types of complications were compared between both the groups. Results A total of 1029 surgeries were performed by 22 resident surgeons. In all, 522 (50.7%) were done using MSICS technique and 507 (49.2%) were done by phacoemulsification. Those in the MSICS group were significantly older (age >70?years; 5.7% vs 3.4%; p<0.001) and had worse preoperative visual acuity (visual acuity <6/60; 69.3% vs 40.4%; p<0.001). Postoperatively, the number of patients having BCVA?6/12 was similar in both the groups (84.3% vs 88%; p=0.09). The complication rates were higher in MSICS group (15.1% vs 7.1%, p<0.001). Most common risk factor for poor outcome (postoperative BCVA<6/60) in both the groups was presence of associated ocular pathologies (OR 7.4 95% CI 3.4 to 16.4) and having a complications (OR 5.7 95% CI 3.0 to 10.8). Conclusions Although the complication rate was higher in the MSICS group, there was no difference in BCVA in both the groups. PMID:23059846

  7. Design of Multi-point Wireless Temperature and Humidity Sensor Network Based on NRF24l01

    Directory of Open Access Journals (Sweden)

    Jin Gang

    2013-01-01

    Full Text Available Many fields need to use the multi-point data acquisition and transmission system to overcome the weakness of wired data transmission system. Based on the single chip transceiver nRF24L01 and favorite microprocessor STM32F107, designed the multi-point wireless sensor network. The system used the 1-wire temperature and humidity sensor DHT22 as Data acquisition components. The paper studied the hardware construction and the software design in details. Designed the circuit diagram, made the PCB plate, programmed software by Keil C and debugged with Keil uVision4 MDK V4.10. Results show that, the multi-point wireless sensor network can work more efficiently and more flexibility. It meets the performance requirements of high real-time, low power consumption and low cost.

  8. Chapter 2. Eyes

    International Nuclear Information System (INIS)

    Ocular scintigraphy can now be carried out with several tracers: 131I diiodofluorescein and sup(99m)Tc, hypervascularisation indicators; 131I iodinated chloroquine, melanoma selective. The detector used is an Anger scintillation camera coupled to a multiparameter analysis chain or a computer. The ''pin-hole'' type collimator, which has a stenopaeic opening in front of each eye, is adaptable to any inter-pupil distance. The very simple scintigraphic procedure is described. The results, taken from two statistical studies on 198 and 80 patients respectively, concern the main types of eye disease encountered: malignant melanic tumours, other tumours, metastases, choroiditis, idiopathic detachments of the retina etc... The interpretation of the scintigrams and the problems involved are considered. Finally the main indications of the method are defined with emphasis on the possibilities of double scintigraphy, diiodofluorescein only showing up the hypervascularisation often associated with the tumour whereas iodinated chloroquine, when the result is positive, points to the presence of a malignant melanoma

  9. Design and Implementation of Numerical Linear Algebra Algorithms on Fixed Point DSPs

    Directory of Open Access Journals (Sweden)

    Gene Frantz

    2007-01-01

    Full Text Available Numerical linear algebra algorithms use the inherent elegance of matrix formulations and are usually implemented using C/C++ floating point representation. The system implementation is faced with practical constraints because these algorithms usually need to run in real time on fixed point digital signal processors (DSPs to reduce total hardware costs. Converting the simulation model to fixed point arithmetic and then porting it to a target DSP device is a difficult and time-consuming process. In this paper, we analyze the conversion process. We transformed selected linear algebra algorithms from floating point to fixed point arithmetic, and compared real-time requirements and performance between the fixed point DSP and floating point DSP algorithm implementations. We also introduce an advanced code optimization and an implementation by DSP-specific, fixed point C code generation. By using the techniques described in the paper, speed can be increased by a factor of up to 10 compared to floating point emulation on fixed point hardware.

  10. Design of a Floating-Point Fused Add-Subtract Unit Using Verilog

    Directory of Open Access Journals (Sweden)

    Mayank Sharma,

    2013-06-01

    Full Text Available A floating-point (FP fused add-subtract unit is presented that performs simultaneous floating-point operation of add-subtract on a common pair of single-precision data at the same time that it takes to perform in a single addition with a conventional floating-point adder. The system was placed and routed in 45nm process so that there will be less consumption of memory as well as power.

  11. CETF Space Station payload pointing system design and analysis feasibility study. [Critical Evaluation Task Force

    Science.gov (United States)

    Smagala, Tom; Mcglew, Dave

    1988-01-01

    The expected pointing performance of an attached payload coupled to the Critical Evaluation Task Force Space Station via a payload pointing system (PPS) is determined. The PPS is a 3-axis gimbal which provides the capability for maintaining inertial pointing of a payload in the presence of disturbances associated with the Space Station environment. A system where the axes of rotation were offset from the payload center of mass (CM) by 10 in. in the Z axis was studied as well as a system having the payload CM offset by only 1 inch. There is a significant improvement in pointing performance when going from the 10 in. to the 1 in. gimbal offset.

  12. New pediatric vision screener employing polarization-modulated, retinal-birefringence-scanning-based strabismus detection and bull's eye focus detection with an improved target system: opto-mechanical design and operation

    Science.gov (United States)

    Irsch, Kristina; Gramatikov, Boris I.; Wu, Yi-Kai; Guyton, David L.

    2014-06-01

    Amblyopia ("lazy eye") is a major public health problem, caused by misalignment of the eyes (strabismus) or defocus. If detected early in childhood, there is an excellent response to therapy, yet most children are detected too late to be treated effectively. Commercially available vision screening devices that test for amblyopia's primary causes can detect strabismus only indirectly and inaccurately via assessment of the positions of external light reflections from the cornea, but they cannot detect the anatomical feature of the eyes where fixation actually occurs (the fovea). Our laboratory has been developing technology to detect true foveal fixation, by exploiting the birefringence of the uniquely arranged Henle fibers delineating the fovea using retinal birefringence scanning (RBS), and we recently described a polarization-modulated approach to RBS that enables entirely direct and reliable detection of true foveal fixation, with greatly enhanced signal-to-noise ratio and essentially independent of corneal birefringence (a confounding variable with all polarization-sensitive ophthalmic technology). Here, we describe the design and operation of a new pediatric vision screener that employs polarization-modulated, RBS-based strabismus detection and bull's eye focus detection with an improved target system, and demonstrate the feasibility of this new approach.

  13. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... It's Not OK to Skip a Day To control glaucoma, take eye drops exactly as prescribed by ... Eye M.D. the benefits and risks — including quality of life issues — that could result from correcting ...

  14. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... Alternative Refractive Surgery Procedures Find An Eye M.D. Enter zip code here Search by Name, City, State or Subspecialty > Ask An Eye M.D. Enter your question here... Browse Top Answers > Privacy ...

  15. Eye Drop Tips

    Science.gov (United States)

    Eye Drop Tips en Español email Send this article to a friend by filling out the fields below: ... the reach of children. Steps For Putting In Eye Drops: Start by tilting your head backward while sitting, ...

  16. What Is Dry Eye?

    Medline Plus

    Full Text Available ... can also produce a lot of tears in response to eye irritation or emotion. When a foreign ... tearing, but think of it as the eye's response to discomfort. If the tears responsible for maintaining ...

  17. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... Page: Alternative Refractive Surgery Procedures Find An Eye M.D. Enter zip code here Search by Name, City, State or Subspecialty > Ask An Eye M.D. Enter your question here... Browse Top Answers > ...

  18. Diabetic Eye Problems

    Science.gov (United States)

    ... too high. Over time, this can damage your eyes. The most common problem is diabetic retinopathy. It ... light-sensitive tissue at the back of your eye. You need a healthy retina to see clearly. ...

  19. Eye Disease Simulations

    Science.gov (United States)

    ... Research at NEI Education Programs Training and Jobs Eye Disease Simulations Listen Age-Related Macular Degeneration Cataract ... information page Back to top Diabetic Retinopathy Diabetic Eye Disease information page Back to top Glaucoma Glaucoma ...

  20. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Diagnosis Dry Eye Treatment Sometimes people don't produce enough tears or the right quality of tears ... comfortable. The eye uses two different methods to produce tears. It can make tears at a slow, ...

  1. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... Usage & Eye Strain Maintaining Your Sight with Diabetes Sports and Eye Protection Eyesight Risks for Smokers Veterans & ... Protection Works Wearing the proper protective eyewear for sports and other activities can help prevent 90% of ...

  2. Eye Cosmetic Safety

    Science.gov (United States)

    ... Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products Cosmetics Print this page Share this page E-mail this page Home Cosmetics Products & Ingredients Products Eye Cosmetic Safety Most eye cosmetics are safe when used ...

  3. LASIK - Laser Eye Surgery

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    Full Text Available ... activities can help prevent 90% of eye injuries. It's Not OK to Skip a Day To control ... prescribed by your ophthalmologist—your sight depends on it. Give your Eyes a Break To prevent computer ...

  4. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... right eye care provider for your condition or treatment. Are You Fit at 40? A baseline eye ... in 1998, LASIK is has become a popular treatment in the United States and the overall complication ...

  5. Diabetes - eye care

    Science.gov (United States)

    ... replace the dilated eye exam. This is called digital retinal photography. Your eye doctor may ask you ... Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology . 12th ed. Philadelphia, PA: Elsevier Saunders; ...

  6. The study of air showers by the Fly's-Eye

    International Nuclear Information System (INIS)

    The Fly's-Eye is an optical-electronic system designed to detect scintillation and Cherenkov light from ultra-high-energy cosmic ray air showers. For about 9 months, 48 out of the total 67 mirrors of the system have been operated. Air showers with greater than 1017 eV are being detected and reconstructed by the University of Utah Cosmic Ray Group. The Fly's-Eye will allow the development of individual showers in the atmosphere to be studied and will be able to observe showers many kilometers away. Besides observing the spectrum and anisotropy of air showers from 1017 to 1020 eV cosmic ray nuclei, the system may also detect point sources of 1014 to 1016eV ?-rays. Preliminary data from a search for ?-rays from the vicinity of the Crab Pulsar are presented

  7. The injured eye

    OpenAIRE

    Scott, Robert

    2011-01-01

    Eye injuries come at a high cost to society and are avoidable. Ocular blast injuries can be primary, from the blast wave itself; secondary, from fragments carried by the blast wind; tertiary; due to structural collapse or being thrown against a fixed object; or quaternary, from burns and indirect injuries. Ballistic eye protection significantly reduces the incidence of eye injuries and should be encouraged from an early stage in Military training. Management of an injured eye requires meticul...

  8. What Is Dry Eye?

    Medline Plus

    Full Text Available ... ask an eye M.D. Search GetEyeSmart.org Diseases & Conditions A to Z Age-related Macular Degeneration (AMD) Allergies Amblyopia (Lazy Eye) Astigmatism Bacterial Keratitis Bell's Palsy Blepharitis Cataracts Contact Lens-Related ...

  9. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Eyelid Lump Feel Something in Eye Flashes of Light Irritation Itchiness Light Sensitivity Red Eye Reduced Vision Tearing See all ... Resources EyeWiki contact us sitemap Reproducing text or images from this website is strictly prohibited by US ...

  10. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... 40? A baseline eye exam is recommended at age 40, when the signs of disease and changes in vision may start ... the clear, round dome at the front of the eye — to improve the way the eye focuses light rays onto the retina ...

  11. What Is Dry Eye?

    Medline Plus

    Full Text Available ... excess tears then overflow from your eye. Next Page: Causes of Dry Eye Written by Kierstan Boyd Reviewed by Dr. Devin Harrison on March 1, 2014 Search for Questions & Answers Search QA Browse all answered questions > Related Resources Related Topics Four Ways to Fight Dry Eye Six Smart ...

  12. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Questions & Answers Search QA Browse all answered questions > Related Resources Related Topics Four Ways to Fight Dry Eye Six ... Only - Eye M.D.-approved information from EyeSmart Related Answers Is it true that taking high doses ...

  13. What Is Dry Eye?

    Medline Plus

    Full Text Available ... all Diseases & Conditions > Symptoms Blurriness Dark Curtain Dark Spots Discharge Double Vision Drooping Eyelid Eye Pain Eyelash Crusting Eyelid Lump Feel Something in Eye Flashes of Light Irritation Itchiness Light Sensitivity Red Eye Reduced Vision Tearing See all Symptoms > Glasses, ...

  14. Eye and orbital cavity

    International Nuclear Information System (INIS)

    Radioanatomy of eyes and orbit is described. Diseases of the orbit (developmental anomalies, inflammatory diseases, lacrimal apparatus deseases, toxoplasmosis, tumors and cysts et al.), methods of foreign body localization in the eye are considered. Roentgenograms of the orbit and calculation table for foreign body localization in spherical eyes of dissimilar diameter are presented

  15. Dwarf Eye Disorder

    Science.gov (United States)

    Science Teacher, 2005

    2005-01-01

    Johns Hopkins researchers at the Wilmer Eye Institute have discovered what appears to be the first human gene mutation that causes extreme farsightedness. The researchers report that nanophthalmos, Greek for "dwarf eye," is a rare, potentially blinding disorder caused by an alteration in a gene called MFRP that helps control eye growth and…

  16. What Is Dry Eye?

    Medline Plus

    Full Text Available ... tearing occurs. It may not sound logical that dry eye would cause excess tearing, but think of it as the eye's response to discomfort. If the tears responsible for maintaining lubrication do not keep the eye wet enough, the ...

  17. Sensitivity of Design Optimality Criteria to Second-order Response SurfaceModel Restrictions and Center Point Replications

    Directory of Open Access Journals (Sweden)

    Angela U. Chukwu

    2012-02-01

    Full Text Available

    Abstract In this work, we investigate the role of several model characteristics and center point replications on the properties of A-, D-, G-, and IV- optimality for four –factor second-order response surface design. It was discovered that A-, D-, and G- efficiencies tend to reduce as the center points are replicated while the effect on scaled average prediction variance tends to be very insignificant. Among the restricted models considered, the pure linear model (model1 turns out to be the best in terms of quality of estimation and model prediction.

    Key words: Design optimality criteria; Center point replications; Response surface methodology

  18. Dependence of instrumental line shape of a magnetic spectrometer upon its ion-optical and design parameters (point source)

    International Nuclear Information System (INIS)

    Stated is a general dependence of the instrumental line shape (ILS) of a magnetic spectrometer upon its ion-optical and design parameters. The calculation of the spectrometer ILS was made for a point source and flat beams. A detailed consideration is given for a new method of designing the instrumental line of the magnetic spectrometer, which permits to find ILS by a simple geometrical constructing. The spectrometer ILS with an odd-order focusing has been studied. Problems of improvement of the basis resolution of the instrument by changing its design peculiarities, e.g. by a specific arrangement of diaphragms , are discussed

  19. [Eye muscle surgery].

    Science.gov (United States)

    Steffen, H

    2015-03-01

    Eye muscle surgery is as a rule surgery on healthy eyes. It therefore requires particularly high standards in terms of a lack of complications and predictability of surgical results. Misalignment of the eyes, binocular diplopia and ocular torticollis are all indications for eye muscle surgery as are enlargement of the binocular visual field, asthenopic complaints in heterophoria or the stabilization of binocular functions. Eye muscle surgery is binocular surgery and differs from monocular surgery. It has its own complications and requires specific skills. PMID:25735630

  20. General Didactics and Instructional Design: eyes like twins A transatlantic dialogue about similarities and differences, about the past and the future of two sciences of learning and teaching.

    Science.gov (United States)

    Zierer, Klaus; Seel, Norbert M

    2012-01-01

    Although General Didactics (GD) and Instructional Design (ID) have not shown many points of contact in the past, there are some obvious parellels from the perspective of their historical development. This will be examined in detail in this article. More specifically, we speak about model building, which has characterized General Didactics and Instructional Design for some decades. However, the models of General Didactics and Instructional Design are not problem-free with regard to the continuity and advancement of both disciplines. First, we will describe the historical roots of both disciplines and examine which elements of theory are of central importance. Second, we will try to answer the question of which kind of model building could be considered as predominant and what problems result from this predominance. In order to do this, we will describe empirical studies on the use of instructional models and discuss these studies from the perspective of the philosophy of science. Third, we will draw inferences for future processes of model building in order to prevent the same problems that happened in the past from happening again. Finally, we will discuss the issue of what General Didactics can learn from Instructional Design and vice versa. PMID:23961346

  1. Poverty and Eye Health

    Directory of Open Access Journals (Sweden)

    Jyoti Jaggernath

    2014-07-01

    Full Text Available Poverty and eye health, including vision disability from vision impairment and blindness, are believed to be interrelated. The relationship between poverty and eye health can be interpreted as being two-fold, in the sense that poverty may be a cause of poor eye health and poor eye health may lead to or deepen poverty. Evidence shows that the burden of vision impairment is high in poor people and vision impairment and poverty are linked to each other. However the empirical evidence to answer the questions—Does poverty perpetuate poor eye health? How and why? Does poor eye health deepen poverty?—is sparse globally; especially from low and middle income countries (LMICs. This article therefore aims to examine published information and other secondary data sources that provide insight on the relationship between poverty and eye health, including eye disability caused from vision impairment and blindness. The article provides a conceptual understanding of poverty related attributes that contribute to eye disability from vision impairment and blindness, using evidence sourced from poverty and eye health research studies. The article interrogates general theories and beliefs that have been conceptualised in relation to the impact that the vicious cycle of poverty has on eye health and the contribution of poor eye health on an individual’s poverty status. The major outcomes of this article include: 1 identifying gaps in linking poverty and eye health, 2 establishing key issues that will assist in the development of a theoretical framework, and 3 preparing more appropriately for further investigation on the association between poverty and eye health.

  2. Individual eye model based on wavefront aberration

    Science.gov (United States)

    Guo, Huanqing; Wang, Zhaoqi; Zhao, Qiuling; Quan, Wei; Wang, Yan

    2005-03-01

    Based on the widely used Gullstrand-Le Grand eye model, the individual human eye model has been established here, which has individual corneal data, anterior chamber depth and the eyeball depth. Furthermore, the foremost thing is that the wavefront aberration calculated from the individual eye model is equal to the eye's wavefront aberration measured with the Hartmann-shack wavefront sensor. There are four main steps to build the model. Firstly, the corneal topography instrument was used to measure the corneal surfaces and depth. And in order to input cornea into the optical model, high-order aspheric surface-Zernike Fringe Sag surface was chosen to fit the corneal surfaces. Secondly, the Hartmann-shack wavefront sensor, which can offer the Zernike polynomials to describe the wavefront aberration, was built to measure the wavefront aberration of the eye. Thirdly, the eye's axial lengths among every part were measured with A-ultrasonic technology. Then the data were input into the optical design software-ZEMAX and the crystalline lens's shapes were optimized with the aberration as the merit function. The individual eye model, which has the same wavefront aberrations with the real eye, is established.

  3. Organization of eye bank

    International Nuclear Information System (INIS)

    Comeal transplantation is the only method of combating the blindness due to corneal opacity caused by infections, malnutrition, trauma and hereditary diseases. Comeal blindness is more prevalent in the developing countries. The availability of the donor cornea, trained ophthalmic surgeons and microsurgery facilities are the key factors in restoring vision in-patients with comeal blindness. The eye bank organization is somewhat similar to that of blood bank. The eye bank should be located in a hospital or a medical centre in which a laboratory may be established for the evaluation and storage of donor tissue. The medical director (Ophthalmologist), technician, secretary and public relation officer are the persons who play an important role in the successful organization of eye bank. The function of the eye bank are procurement, assessment, processing, distribution of donor eyes/corneas, training of technicians/doctors, and conducting research related to storage of donor tissue and corneal transplantation. The necessary infrastructure required for the organization of an eye bank include separate accommodation area for the personnel and the laboratory, telephone, computer, refrigerator, laminar air flow hood. Slitlamp, specular microscope, storage media and equipment, instrument for enucleation of donor eyes, and a motor vehicle. The details of responsibilities of the staff of eye bank, source of donor eyes, suitability of donor material, procurement of the donor cornea,material, procurement of the donor cornea, tissue assessment, storage and preservation, distribution of donor tissue, and limitation of eye bank will be discussed at the time of presentation

  4. Eye tracking young children with autism.

    Science.gov (United States)

    Sasson, Noah J; Elison, Jed T

    2012-01-01

    The rise of accessible commercial eye-tracking systems has fueled a rapid increase in their use in psychological and psychiatric research. By providing a direct, detailed and objective measure of gaze behavior, eye-tracking has become a valuable tool for examining abnormal perceptual strategies in clinical populations and has been used to identify disorder-specific characteristics, promote early identification, and inform treatment. In particular, investigators of autism spectrum disorders (ASD) have benefited from integrating eye-tracking into their research paradigms. Eye-tracking has largely been used in these studies to reveal mechanisms underlying impaired task performance and abnormal brain functioning, particularly during the processing of social information. While older children and adults with ASD comprise the preponderance of research in this area, eye-tracking may be especially useful for studying young children with the disorder as it offers a non-invasive tool for assessing and quantifying early-emerging developmental abnormalities. Implementing eye-tracking with young children with ASD, however, is associated with a number of unique challenges, including issues with compliant behavior resulting from specific task demands and disorder-related psychosocial considerations. In this protocol, we detail methodological considerations for optimizing research design, data acquisition and psychometric analysis while eye-tracking young children with ASD. The provided recommendations are also designed to be more broadly applicable for eye-tracking children with other developmental disabilities. By offering guidelines for best practices in these areas based upon lessons derived from our own work, we hope to help other investigators make sound research design and analysis choices while avoiding common pitfalls that can compromise data acquisition while eye-tracking young children with ASD or other developmental difficulties. PMID:22491039

  5. Numerical investigation of the cavitational behaviour into a storage pump at off design operating points

    Energy Technology Data Exchange (ETDEWEB)

    Stuparu, A; Susan-Resiga, R; Anton, L E [Department of Hydraulic Machinery, Politehnica University of Timisoara, Bd. Mihai Viteazu 1, Timisoara, 300222 (Romania); Muntean, S, E-mail: astuparu@mh.mec.upt.r [Centre of Advanced Research in Engineering Science, Romanian Academy-Timisoara Branch, Bd. Mihai Viteazu 24, Timisoara, 300223 (Romania)

    2010-08-15

    The paper presents a new method for the analysis of the cavitational behaviour of hydraulic turbomachines. This new method allows determining the coefficient of the cavitation inception and the cavitation sensitivity of the turbomachines. We apply this method to study the cavitational behaviour of a large storage pump. By plotting in semi-logarithmic coordinates the vapour volume versus the cavitation coefficient, we show that all numerical data collapse in an exponential manner. This storage pump is located in a power plant and operating without the presence of the developed cavitation is vital. We investigate the behaviour of the pump from the cavitational point of view while the pump is operating for variable discharge. A distribution of the vapour volume upon the blade of the impeller is presented for all the four operating points. It can be seen how the volume of vapour evolves from one operating point to another. In order to study the influence of the cavitation phenomena upon the pump, the evolution of the pumping head against the cavitation coefficient is presented. That will show how the pumping head drops while the cavitation coefficient decreases. From analysing the data obtained from the numerical simulation it results that the cavitation phenomena is present for all the investigated operating points. By analysis of the slope of the curve describing the evolution of the vapour volume against the cavitation coefficient we determine the cavitation sensitivity of the pump for each operating point. It is showed that the cavitation sensitivity of the investigated storage pump increases while the flow rate decreases.

  6. Improvements in packages comprising eye baths and eye lotions

    International Nuclear Information System (INIS)

    A new packaged assembly comprising an eye bath and eye lotion is described. The eye bath is shaped for application to the eye; it has a rim portion formed so as to provide a smooth skin-contacting surface and is sealed to a lid at a position removed from the skin-contacting area. The eye bath is formed in a sterile condition and aseptically filled to an appropriate level with eye lotion by a blow moulding process. The eye bath and its contents are sterilised after sealing by radioactive sterilsation. This packaged assembly is an improvement over previous eye bath assemblies in that it allows the eye bath to be used in a sterile form. It is also more comfortable and convenient to use than other sterile forms of eye treatment such as eye drops or jets of eye wash. Furthermore, bathing the eye provides a more prolonged treatment. (U.K.)

  7. Different schematic eyes and their accuracy to the in vivo eye: a quantitative comparison study

    Scientific Electronic Library Online (English)

    Marina Storani de, Almeida; Luis Alberto, Carvalho.

    2007-06-01

    Full Text Available SciELO Brazil | Language: English Abstract in english Current ophthalmic technology allows the manipulation of eye components, such as anterior cornea and lens, of the human eye with a considerable precision and customization. This technology opens up the possibility of exploiting some characteristics of the eye in order to improve the methods of corre [...] cting optical aberrations. Moreover, product development and research for the eye-care professional has reached very high standards, since there is nowadays software available to design and simulate practically any mechanical or optical characteristic of the product, even before it is thrown into production line. Although quite similar in the general form, different human eye models simulate the image formation by considering different property combinations in the constitutive elements of the eye structure (such as refraction index and surface curvatures), producing retinal images that resemble very closely those of the biological eye. Using optical design software, we have implemented a simulation of 5 well-known schematic eyes available in the literature. These models were the Helmholtz-Laurance, Gullstrand, Emsley, Greivenkamp and Liou & Brennan. The optical performance of these different models was compared using different quantitative optical quality parameters. The model of Liou and Brennan, contains features of the biological eye that were not considered in previous models, as the distribution of a gradient refraction index and a decentered pupil. Furthermore, it has great reliability since it takes into account the mean value of empirical measurements of the in vivo eye in order to define size and parameters such as anterior and posterior curvature of cornea, lens, axial length, etc. Comparisons between the MTF (Modulation Transfer Function), spot diagrams and ray fan showed the difference in image quality between eye models, and the Strehl Ratio was also used as a parameter of comparison. A careful comparison between the different models showed that the first four schematic eyes have better optical quality than what is expected for the general and healthy emmetropic in vivo eye. Liou and Brennan schematic eye is the one that most closely resembles the in vivo biological eye. Therefore, in applications, such as research or product development for customized vision correction, which must consider optical properties intrinsic to the biological eye, we recommend this latter model; for applications that do not require refraction-limited performance, most of the other models should be a good approximation.

  8. Improving eye care in the primary health care setting

    Directory of Open Access Journals (Sweden)

    M de Wet

    2000-09-01

    Full Text Available One of the challenges facing primary health care in South Africa is the delivery of quality eye care to all South Africans. In this regard the role of the primary health care worker, as the first point of contact, is crucial. This paper reports on the problems primary health care workers experience in providing quality eye care in Region B of the Free State. Problems identified by those involved in the study include the cumbersome referral system, the unavailability of appropriate medicine at clinics, the insufficient knowledge of primary health care workers regarding eye conditions and the lack of communication between the various eye care service providers. Suggestions to address the problems identified included more in-service training of primary health care workers regarding eye conditions, liaison with NGO’s providing eye care, decentralisation of services and the establishment of an eye care committee in the region.

  9. Teamwork for eye care

    Directory of Open Access Journals (Sweden)

    M Babar Qureshi

    2014-04-01

    Full Text Available Human resource development (HRD – the development of the people who deliver health care – has been identified as one of the key pillars of eye health delivery. HRD is one of the essential building blocks of the World Health Organization (WHO Global Action Plan: ‘Towards universal eye health’. The importance of HRD is also recognised beyond eye care, as can be seen in the WHO Health Systems approach.

  10. Eye movement tics.

    OpenAIRE

    Shawkat, F.; Harris, C. M.; Jacobs, M.; Taylor, D.; Brett, E. M.

    1992-01-01

    An 8-year-old girl presented with opsoclonus-like eye movement and an 18 month history of intermittent facial tics. Investigations were all normal. Electro-oculography showed the eye movements to be of variable amplitude (10-40 degrees), with no intersaccadic interval, and with a frequency of 3-4 Hz. Saccades, smooth pursuit, optokinetic, and vestibular reflexes were all normal. These abnormal eye movements eventually disappeared. It is thought that they were a form of ocular tics.

  11. The Next Generation Nuclear Plant - Insights Gained from the INEEL Point Design Studies

    Energy Technology Data Exchange (ETDEWEB)

    Philip E. MacDonald; A. M. Baxter; P. D. Bayless; J. M. Bolin; H. D. Gougar; R. L. Moore; A. M. Ougouag; M. B. Richards; R. L. Sant; J. W. Sterbentz; W. K. Terry

    2004-08-01

    This paper provides the results of an assessment of two possible versions of the Next Generation Nuclear Plant (NGNP), a prismatic fuel type helium gas-cooled reactor and a pebble-bed fuel helium gas reactor. Insights gained regarding the strengths and weaknesses of the two designs are also discussed. Both designs will meet the three basic requirements that have been set for the NGNP: a coolant outlet temperature of 1000 C, passive safety, and a total power output consistent with that expected for commercial high-temperature gas-cooled reactors. Two major modifications of the current Gas Turbine- Modular Helium Reactor (GT-MHR) design were needed to obtain a prismatic block design with a 1000 C outlet temperature: reducing the bypass flow and better controlling the inlet coolant flow distribution to the core. The total power that could be obtained for different core heights without exceeding a peak transient fuel temperature of 1600 °C during a high or low-pressure conduction cooldown event was calculated. With a coolant inlet temperature of 490 °C and 10% nominal core bypass flow, it is estimated that the peak power for a 10-block high core is 686 MWt, for a 12-block high core is 786 MWt, and for a 14-block core is about 889 MWt. The core neutronics calculations showed that the NGNP will exhibit strongly negative Doppler and isothermal temperature coefficients of reactivity over the burnup cycle. In the event of rapid loss of the helium gas, there is negligible core reactivity change. However, water or steam ingress into the core coolant channels can produce a relatively large reactivity effect. Two versions of an annular pebble-bed NGNP have also been developed, a 300 and a 600 MWt module. From this work we learned how to design passively safe pebble bed reactors that produce more than 600 MWt. We also found a way to improve both the fuel utilization and safety by modifying the pebble design (by adjusting the fuel zone radius in the pebble to optimize the fuel-to-moderator ratio). We also learned how to perform design optimization calculations by using a genetic algorithm that automatically selects a sequence of design parameter sets to meet specified fitness criteria increasingly well. In the pebble-bed NGNP design work, we use the genetic algorithm to direct the INEEL’s PEBBED code to perform hundreds of code runs in less than a day to find optimized design configurations. And finally, we learned how to calculate cross sections more accurately for pebble bed reactors, and we identified research needs for the further refinement of the cross section calculations.

  12. Minority Eye Health: Know Your Risks

    Science.gov (United States)

    ... the Sun Eye Health News Consumer Alerts Minority Eye Health: Know Your Risks Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes ... over the battery and always wear safety goggles. Eye Protection Works Wearing the proper protective eyewear for ...

  13. Design and Evaluation of Cell Phone Pointing Interface for Robot Control

    OpenAIRE

    Saso Koceski; Natasa Koceska; Ivica Kocev

    2012-01-01

    In this work a pointing interface based on human gestures using a mobile phone accelerometer for interaction with robots is proposed. Through this interface the user can sketch stroke gestures on a computer screen using the cell phone accelerometer to make a selection and instruct a robot to perform a task. Selection, cancelation and movement, as well as some additional commands such as stop, pause and resume are supported. All the projected gestures are processed using known image analysis a...

  14. Integrated design and evaluation of logistic networks: Oriented placement of the order penetration point

    OpenAIRE

    Klingebiel, Katja; Hellingrath, Bernd; Scavarda, Luiz Felipe

    2011-01-01

    The placement of the Order Penetration Point (OPP) is a key decision in automotive supply chains since the product will be differentiated according to the customers' requirements only after the OPP. From a marketing perspective variety proliferation is encouraged. Yet, competition has shifted from individual firms to global supply chains and under given market uncertainty the significance of supply chain flexibility is increasing. Upstream however, the expansion of outsourcing, supplier ratio...

  15. Design and simulation of 64 point FFT using Radix 4 algorithm for FPGA Implementation

    OpenAIRE

    Sreekanth Yadav, K.

    2013-01-01

    The Fast Fourier Transform (FFT) is one of the rudimentary operations in field of digital signal, image processing and FFT processor is a critical block in all multicarrier systems used primarily in the mobile environment. Fast Fourier transform (FFT) is an efficient implementation of the discrete Fourier transform (DFT). The portability requirement of these systems is mainly responsible for the need of low power FFT architectures. . In this study, the development of 64 point FFT, based on De...

  16. Brewery and winery wastewater treatment : some focal points of design and operation

    OpenAIRE

    Brito, A. G.; Peixoto, J.; Oliveira, J. M.; Oliveira, J. A.; Costa, Cristina; Nogueira, R.; Rodrigues, A. C.

    2007-01-01

    Environmental issues are a critical factor for the today industry competitiveness. Indeed, the society and the individual consumers could set a common framework for companies’ commitment and engagement regarding environment protection. Redesign the process, recover by-products or reuse effluents are some of the possible actions towards an eco-efficient strategy. Nevertheless, a point remains crucial in such mission: the ability to defend natural ecosystems from polluted wastewaters. For suc...

  17. Poverty and Eye Health

    OpenAIRE

    Jyoti Jaggernath; Lene Øverland; Prasidh Ramson; Vilas Kovai; Ving Fai Chan; Naidoo, Kovin S.

    2014-01-01

    Poverty and eye health, including vision disability from vision impairment and blindness, are believed to be interrelated. The relationship between poverty and eye health can be interpreted as being two-fold, in the sense that poverty may be a cause of poor eye health and poor eye health may lead to or deepen poverty. Evidence shows that the burden of vision impairment is high in poor people and vision impairment and poverty are linked to each other. However the empirical evidence to answer t...

  18. Design of intelligent distributed control systems: a dependability point of view

    International Nuclear Information System (INIS)

    The use of fieldbuses and the emergence of intelligent sensors and actuators are opening up new possibilities for distributed control systems, but are also introducing additional constraints in terms of achieving dependability objectives. The type of production environment will greatly determine the predominant criterion for an automatic control system, i.e. reliability, availability, maintainability, safety, etc. On the other hand, the choice of a fieldbus system will also depend on factors such as application size, data throughput, and integration of time considerations. Other important criteria include cost, confidentiality, and compatibility with existing equipment. Therefore, it appears essential that designers be given the means to assess dependability at each design step by integrating feedback from experience. Assessing dependability is too often limited to an evaluation at the end of the design process, which often involves reselecting previous choices. The main topic of this paper is to focus on the communication function which is a pivotal of intelligent distributed control systems. So this article is a synthesis of different aspects linked to the design of fieldbus based applications thanks to the contributors, who come from various fields. Consequently it highlights the main problem and give some ways to solve them

  19. Amblyopia: Lazy Eye Symptoms

    Science.gov (United States)

    ... Screening Guidelines Home Remedies for Simple Eye Problems Medical Marijuana for Glaucoma Pregnancy Preventing Eye Injuries Smokers Sports ... Policy Email address ... text or images from this website is strictly prohibited by US and international copyright law. You may link from your website to any ...

  20. Amblyopia: Lazy Eye Diagnosis

    Science.gov (United States)

    ... Screening Guidelines Home Remedies for Simple Eye Problems Medical Marijuana for Glaucoma Pregnancy Preventing Eye Injuries Smokers Sports ... Policy Email address ... text or images from this website is strictly prohibited by US and international copyright law. You may link from your website to any ...

  1. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Screening Guidelines Home Remedies for Simple Eye Problems Medical Marijuana for Glaucoma Pregnancy Preventing Eye Injuries Smokers Sports ... Policy Email address ... text or images from this website is strictly prohibited by US and international copyright law. You may link from your website to any ...

  2. Amblyopia: Lazy Eye Treatment

    Science.gov (United States)

    ... Screening Guidelines Home Remedies for Simple Eye Problems Medical Marijuana for Glaucoma Pregnancy Preventing Eye Injuries Smokers Sports ... Policy Email address ... text or images from this website is strictly prohibited by US and international copyright law. You may link from your website to any ...

  3. What Is Dry Eye?

    Medline Plus

    Full Text Available ... eye health and preserving your vision. Privacy Policy Email address © 2015 American Academy of Ophthalmology medical disclaimer privacy policy sponsorship & advertising policies about us Educational Resources EyeWiki contact us sitemap Reproducing text or images from this ...

  4. Design of Ultrasonically-Activatable Nanoparticles using Low Boiling Point Perfluorocarbons

    OpenAIRE

    Sheeran, Paul S.; Luois, Samantha; Mullin, Lee; Matsunaga, Terry O.; Dayton, Paul A.

    2012-01-01

    Recently, an interest has developed in designing in biomaterials for medical ultrasonics that can provide the acoustic activity of microbubbles, but with improved stability in vivo and a smaller size distribution for extravascular interrogation. One proposed alternative is the phase-change contrast agent. Phase-change contrast agents (PCCAs) consist of perfluorocarbons (PFCs) that are initially in liquid form, but can then be vaporized with acoustic energy. Crucial parameters for PCCAs includ...

  5. Flavonoid intake and eye health.

    Science.gov (United States)

    Milbury, Paul E

    2012-01-01

    In the modern era of evidence-based scientific medicine, there is little recognition of centuries of shaman observational evidence. Yet it is extremely difficult to conduct long duration controlled studies of large populations. The controversy surrounding the issue of flavonoid bioactivity and alleged benefits for eye health is also plagued by natural product industry marketing efforts that rely on small, often poorly designed studies. Ample laboratory evidence exists from in vitro and in vivo studies that provide plausible mechanistic evidence for flavonoid interactions relevant to visual function. Lacking are large randomized double-blind placebo-controlled studies in older subjects who have early signs of vision impairment. These studies could link flavonoid intake and bioavailability to efficacy in prevention of age related vision disorders that develop over decades. Support for clinical trials remains to be found before a full "recommendation" can be made regarding the value of diets high in flavonoids for eye health. PMID:22888841

  6. [L-THIA-based management design for controlling urban non-point source pollution].

    Science.gov (United States)

    Guo, Qing-Hai; Yang, Liu; Ke-Ming, Ma

    2007-11-01

    L-THIA Model was used to simulate the amounts of NPS pollutants in 2 catchments of Sanjiao watershed (Sj1, Sj2) in Hanyang district, and the total simulated amount of NPS loads in Sj1 and Sj2 were 1.82 x 10(4) kg, 1.38 x 10(5) kg, respectively. Based on the theory of resource-sink" and interaction of pattern with process, a series of BMPs, including green roof, grassland, porous pavement, infiltration trench, vegetative filter strip and wet pond, were optimized, and effects of BMPs were simulated along the surface runoff pathway. The results show that total pollutants outputs entering Sj1 and Sj2 account for 14.65% and 6.57%, respectively. Combining L-THIA model and BMPs in series is a proper measure for non-point source pollution control and urban development planning at watershed or region scale. PMID:18290459

  7. Financial Aid for Eye Care

    Science.gov (United States)

    ... Research at NEI Education Programs Training and Jobs Financial Aid for Eye Care Listen Financial Aid for Eye Care PDF* Many state and ... care. However, if you are in need of financial aid to assess or treat an eye problem, ...

  8. Medicare Benefits and Your Eyes

    Science.gov (United States)

    Medicare benefits and your eyes Eye Health is Important! As you age, your risk for vision impairment and vision ... the arrows below for detailed information about Medicare benefits and your eyes. Request a Free Copy of ...

  9. Finding an Eye Care Professional

    Science.gov (United States)

    ... Finding an Eye Care Professional PDF* The National Eye Institute does not provide referrals or recommend specific eye ... are currently performing refractive surgery. Offers “Find a Refractive Surgeon” service on their website: ... Administrators in Medicine have launched “DocFinder”, ...

  10. Novel four-point-probe design and nanorobotic dual endeffector strategy for electrical characterization of as-grown SWCNT bundles

    DEFF Research Database (Denmark)

    Eichhorn, V; Fatikow, S

    2010-01-01

    In this paper, a novel nanorobotic strategy for non-destructive and direct electrical characterization of as-grown bundles of single-walled carbon nanotubes (SWCNTs) is presented. For this purpose, test patterns of SWCNT bundles having different diameters are grown on a silicon substrate by chemical vapor deposition. A new design of microstructured four-point-probes is proposed and fabricated allowing for direct contacting of vertically aligned bundles of SWCNTs. A nanorobotic setup is upgraded into a dual endeffector system to achieve good electrical contact between four-point-probe and SWCNT bundle and to perform electrical measurements. First experimental results of non-destructive electrical characterization are presented and discussed.

  11. [Pharmaceutical investigation of vancomycin hydrochloride eye drops and their topical application to MRSA eye infection].

    Science.gov (United States)

    Itoh, M; Aoyama, T; Iemoto, A; Nakajima, K; Amano, S; Nakamura, H; Sato, H; Iga, T

    2001-06-01

    Two formulations of 0.5% vancomycin hydrochloride (VM) eye drops (VM-B and VM-C eye drops) were prepared by dissolving commercial VM powder for injection with preserved water B (PWB) containing phosphate buffer and preserved water C (PWC) containing only antimicrobial preservative, respectively. The VM-B eye drops have neutral pH (about 6.3), and the VM-C eye drops acidic pH of about 3.5. The pharmaceutical examination of these eye drops was performed regarding its clinical application to MRSA eye infection. In an irritability test using a rabbit's eye, the average number of winks after instillation of one drop of VM-B eye drops was 0.8 times/min and significantly smaller than that of VM-C eye drops (2.0 times/min). In dark storage at 4 degrees C, no change of VM concentration in both eye drops was observed for 25 weeks after preparation and the mean residual concentrations as determined by the HPLC-UV (240 nm) method were constant over 90% for 8 weeks, of the initial concentration. However, the residual VM concentration of VM-B eye drops under a room condition declined to 58% after 4 weeks and 20% after 8 weeks, and VM in light storage at 40 degrees C was not detectable after 8 weeks. The drug concentration of VM-C eye drops declined to 83% after 4 weeks and 74% after 8 weeks under a room condition, and to 46% after 4 weeks and 20% after 8 weeks under light storage at 40 degrees C. Under these storage conditions, the precipitation of VM related crystals was observed in both the eye drops when the residual percentage of VM was lower than 80%. Judging from HPLC chromatograms of a solution of the precipitated crystals, it was suggested that this crystal was degradation products of VM. The VM-B eye drops was applied to a patient with MRSA eye infection, because other medication was not effective. After continuous instillation of a drop per times every hour to both eyes, MRSA in corneal culture turned out negative after one week, and the clinical condition was remarkably improved. On the basis of the result of eye-irritability, VM-B eye drops with neutral pH was suggested to be superior to acidic VM-C eye drops from a safety point of view. It was also indicated that VM-B eye drops can be effectively used for 8 weeks under dark storage at 4 degrees C for MRSA eye infection, which is a useful piece information for the proper usage of the VM eye drops. PMID:11433777

  12. Application of 3-Dimensional Printing Technology to Construct an Eye Model for Fundus Viewing Study

    Science.gov (United States)

    Li, Xinhua; Gao, Zhishan; Yuan, Dongqing; Liu, Qinghuai

    2014-01-01

    Objective To construct a life-sized eye model using the three-dimensional (3D) printing technology for fundus viewing study of the viewing system. Methods We devised our schematic model eye based on Navarro's eye and redesigned some parameters because of the change of the corneal material and the implantation of intraocular lenses (IOLs). Optical performance of our schematic model eye was compared with Navarro's schematic eye and other two reported physical model eyes using the ZEMAX optical design software. With computer aided design (CAD) software, we designed the 3D digital model of the main structure of the physical model eye, which was used for three-dimensional (3D) printing. Together with the main printed structure, polymethyl methacrylate(PMMA) aspherical cornea, variable iris, and IOLs were assembled to a physical eye model. Angle scale bars were glued from posterior to periphery of the retina. Then we fabricated other three physical models with different states of ammetropia. Optical parameters of these physical eye models were measured to verify the 3D printing accuracy. Results In on-axis calculations, our schematic model eye possessed similar size of spot diagram compared with Navarro's and Bakaraju's model eye, much smaller than Arianpour's model eye. Moreover, the spherical aberration of our schematic eye was much less than other three model eyes. While in off- axis simulation, it possessed a bit higher coma and similar astigmatism, field curvature and distortion. The MTF curves showed that all the model eyes diminished in resolution with increasing field of view, and the diminished tendency of resolution of our physical eye model was similar to the Navarro's eye. The measured parameters of our eye models with different status of ametropia were in line with the theoretical value. Conclusions The schematic eye model we designed can well simulate the optical performance of the human eye, and the fabricated physical one can be used as a tool in fundus range viewing research. PMID:25393277

  13. Design, manufacturing and measurement of a PV miniconcentrator for front point-contact silicon solar cells

    Science.gov (United States)

    Pérez, D.; Miñano, J. C.; Benítez, P.; Muñoz, F.; Mohedano, R.

    2005-08-01

    A novel photovoltaic concentrator has been developed in the framework of the European project "High efficiency silicon solar cells concentrator". In this project, front-contacted silicon solar cell have also been designed and manufactured by the project leader (the French LETI). This silicon cell concept is potentially capable to perform well (24% efficiency has been predicted) for much higher concentration levels than the back-contacted cells (and, of course, than the two-side contacted cells). The concentrator is formed by one lens of squared contour with flat entry surface and large-facet Fresnel exit surface, and a secondary that encapsulates the solar cell. On the contrary to the conventional Fresnel lens plus nonimaging secondary concentrators, the primary and secondary are designed simultaneously, leading to better concentration-acceptance angle product without compromise with the compactness. The grid lines in the front-contacted cells are aluminium prisms (which contact the p+ and n+ emitters, alternatively), acting as a linear cone concentrator that concentrates Cg =1.52× in the cross sectional dimension of the prisms. The secondary concentrator has a refractive rotational symmetric top surface that is crossed with two linear flow-line TIR mirror. Then, in the cross section normal to the aluminium prisms, the secondary provides a 2D concentration of Cg =12×, while in the cross section parallel to the prisms it provides a 2D concentration of Cg =24.16× as the grid lines in this dimension. Therefore, the cell is rectangular (1:2.08 aspect ratio), being the grid lines parallel to the shorter rectangle side. The total 3D geometrical concentration is 24.16×(12×1.52) = 455× for the square aperture and rectangular cell, and gets a design acceptance angle ?=+/-1.8 degrees. Injection moulded prototypes are have been manufactured and measured, proving an optical efficiency of 79%. Computer modelling of the concentrator performance will also be presented.

  14. Contribution to the design of a micro-programmed floating point arithmetical operator

    International Nuclear Information System (INIS)

    This report is intended for a presentation of the implementation of an arithmetical operator. Fast microprocessor together with microprogramming techniques were used for development. For clarity, this report is shared in three parts following the different steps of design and development. The first part relates the preliminary study stage, setting down the outlines of the project: tentative data, choice of components and architecture of operator. The second part is devoted to the development step. It deals with implementation aid systems and computation algorithms for arithmetical functions. Results and conclusions are the subject of the third part. (author)

  15. Where from here with operational transients: A designer's point of view

    International Nuclear Information System (INIS)

    This chapter discusses the efforts being expended to avoid transients and to minimize the consequences of such transients if they do occur. The development of improved emergency procedures, improved control room designs, improved operator aids, improved site emergency plans, and improved management and technical support for the operations staff are reviewed. Topics considered include preparation, execution, follow-up, computer-based operator ads, instrumentation improvements, and reactor simulators. The benefits to the utility expected from the described improvements include lower forced outage rates, higher availability, and decreased turnover of trained operations personnel

  16. Development of calculation method for the system design parameters at the design point of the passive DHR system in KALIMER-600

    Energy Technology Data Exchange (ETDEWEB)

    Eoh, Jae Hyuk; Sim, Yoon Sub; Kim, Seong O

    2004-01-01

    The conceptual design of a sodium cooled liquid metal reactor, KALIMER (Korea Advanced LIquid MEtal Reactor) of which electric power is 150 MWe, has performed. A revised design concept up-rating electric capacity to 600 MWe, named as KALIMER-600, has been currently developed. The Residual Heat Removal (RHR) system under a loss of normal heat sink accident of KALIMER-600 is characterized by the concept of PDRC (Passive Decay heat Removal Circuit) and it has superiority in the aspect that an enough decay heat removal capacity can be provided and any additional consideration associated with the core thermal power increase can also be neglected since it uses a very simple concept of direct reactor pool cooling. In this regard, a proper method for setting up the steady state design parameters at the design point of PDRC system should be required to secure a sufficient decay heat removal capacity of the RHR system in KALIMER-600. This study describes developing procedure of two different methods for determining the design parameters of PDRC system. They are the rough and the detail analysis method, and the methods have a mutual complementary nature. On the basis of the relationship between the various design parameters produced by using the developed methods, overall characteristics of PDRC system corresponding to the variations of system design parameters have been investigated, and more detail calculations are carried out using the results of the investigations such as the variations of the temperature, pressure loss, mass flowrate and UA values in each heat transfer circuit or heat exchanger in PDRC system. This report also provides the brief procedure of a computational programming for the detail analysis method and, using the computational routine, it is expected that an expansion of applicability to flexibly cope with a design change of PDRC system in KALIMER-600 is possible.

  17. Design and simulation of 64 point FFT using Radix 4 algorithm for FPGA Implementation

    Directory of Open Access Journals (Sweden)

    K.Sreekanth Yadav

    2013-02-01

    Full Text Available The Fast Fourier Transform (FFT is one of the rudimentary operations in field of digital signal, image processing and FFT processor is a critical block in all multicarrier systems used primarily in the mobile environment. Fast Fourier transform (FFT is an efficient implementation of the discrete Fourier transform (DFT. The portability requirement of these systems is mainly responsible for the need of low power FFT architectures. . In this study, the development of 64 point FFT, based on Decimation-In- Time (DIT domain using Radix-4 algorithm. The complex multiplier is one of the most power consuming blocks in the FFT processor. A significant property of the proposed method is that the critical path of the address generator is independent from the FFT transform length N, making it extremely efficient for large FFT transforms. The results confirm the speed and area advantages for large FFTs. Although only radix-4 FFT address generation is presented in the paper, it can be used for higher radix FFT

  18. The construction of individual eye model based on eye's wavefront aberration measurement

    Science.gov (United States)

    Wang, Zhao-Qi; Guo, Huan-Qing

    2005-08-01

    Based on the widely used Gullstrand-Le Grand eye model, the individual human eye model has been established here, which has individual corneal data, anterior chamber depth and the eyeball depth. Furthermore the foremost thing is that the wavefront aberration calculated from the individual eye model is equal to the eye's wavefront aberration measured with the Hartmann-shack wavefront sensor. There were four main steps to build the model. Firstly, the corneal topography instrument was used to measure the corneal surfaces and depth. And in order to input cornea into the optical model, high order aspheric surface-Zernike Fringe Sag surface was chosen to fit the corneal surfaces. Secondly, the Hartmann-shack wavefront sensor, which can offer the Zernike polynomials to describe the wavefront aberration, was built to measure the wavefront aberration of the eye. Thirdly, the eye's axial lengths among every part were measured with A-ultrasonic technology. Then the data were input into the optical design software -ZEMAX and the crystalline lens's shapes were optimized with the aberration as the merit function. The individual eye model, which has the same wavefront aberrations with the real eye, is established.

  19. Point of View: Intelligent Design: Jonathan Wells and the Tree of Life

    Science.gov (United States)

    Thomas Gregg

    2007-07-01

    In recent years, the intelligent design (ID) movement has been very successful in attracting the attention of the general public. The ID movement is centered predominantly at the Center for Science and Culture in the very conservative think tank, the Discovery Institute, of Seattle, Washington. It has gained this attention by completely bypassing scientific channels and going directly to the general public, primarily in the form of op-ed articles, talk-show and TV appearances, and by making their anti-evolution books and video documentaries widely available, especially to school administrators, school boards, teachers, and legislators. The defeat of ID in the highly publicized Dover, Pennsylvania trial will not slow the movement down.

  20. Perceptions of eye health in schools in Pakistan

    Directory of Open Access Journals (Sweden)

    Qureshi Mohammad

    2006-03-01

    Full Text Available Abstract Background Research exploring children's and their teachers' perceptions of eye health is lacking. This paper reports for the first time on perceptions of primary schoolchildren and their teachers of healthy and diseased eyes, things that keep eyes healthy and damage them, and what actions to be taken in case of an eye injury. Methods Using draw and write technique, 160 boys and girls (9–12 years old attending four primary schools in Abbottabad district, northern Pakistan, were invited to draw pictures in response to a set of semi-structured questions and then label them. Sixteen teachers who were currently teaching the selected students were interviewed one-on-one. Results Analysis of text accompanying 800 drawings and of the interview scripts revealed that most children and teachers perceived healthy eyes to be those which could see well, and diseased eyes to be those which have redness, watering, dirty discharge, pain, and itching; or those which have "weak eyesight" and blindness. Among things that students and teachers thought damage the eyes included sun, television, and sharp pointed objects, particularly pencils. Teachers noted that children with eye problems "have difficulty seeing the blackboard well", "screw up their eyes", and "hold their books too close". Conclusion We conclude that schoolchildren and their teachers had a good knowledge of eye health, but many of them had serious misconceptions e.g., use of kohl, medicines and eye drops keeps eyes healthy. Kohl is an important source of lead and can reduce children's intelligence even at low blood levels. Health education in schools must take into account children's existing knowledge of and misconceptions about various aspects of eye health. Such steps if taken could improve the relevance of eye health education to schoolchildren.

  1. Adaptive wavelet eye-gaze based video compression

    OpenAIRE

    Murtagh, Fionn; Farid, M.; Kurugollu, F.

    2002-01-01

    We present a novel approach to compression of video frames based on the foveation behavior of the human visual system (HSV). Eye fixations on a video frame, as depicted by eye-gaze trace data, define an imaginary region of interest. The perceived resolution of the frame by the human eye depends totally on this eye-gaze (fixation) point. The resolution, then, decreases dramatically with the distance from the fovea. This behavior of the HSV has gained interest in the image and video processing ...

  2. Eye injury in sport.

    Science.gov (United States)

    Jones, N P

    1989-03-01

    Eye injury sustained during sport is increasing in incidence worldwide, reflecting the rise in popularity of sport as recreation. It can account for up to 25% of severe eye injuries. This paper considers the historical context and demography of sports injuries, and the physical mechanisms and results of various types of ocular trauma in relation to sport. It reviews the specific problems associated with the sports considered to be most important in the epidemiology of eye injuries today. Certain sports, such as boxing, have an intrinsic risk of injury so high that some consider the sport should be banned. The risk of injury in many sports can be mitigated by changes in rules, such as the prevention of high sticking in ice hockey. Other sports with high risk of trauma could be made far safer with the widespread introduction of eye protection, and this applies especially to squash and badminton. The various types of eye protection are discussed. There is an urgent need to increase awareness of the risk of eye injury, to teach safe techniques, and to encourage the use of appropriate ocular protective wear in those at high risk of injury, especially the one-eyed. PMID:2660211

  3. Eye and orbital cancer

    International Nuclear Information System (INIS)

    Diseases of the eye and orbital contents which can be treated by radiation therapy are relatively uncommon. They include benign diseases such as pterygium, orbital pseudo-tumor, and Graves' exophthalmos. Malignant diseases in adults include orbital and choroidal metastases, lacrimal gland tumors, carcinoma of the bulbar conjunctiva, orbital lymphomas and melanomas. Pediatric malignancies include retinoblastomas, optic nerve gliomas, and orbital rhabdomyosarcomas. Orbital irradiation may result in a variety of normal eye and orbital tissues responses. Those responses may occur when irradiating the eye or orbital diseases listed above or non-orbital primary tumors, such as nasal cavity and paranasal sinus tumors

  4. Eye-Safe Lidar

    Science.gov (United States)

    Byer, Robert L.

    1989-01-01

    Laser infrared radar (lidar) undergoing development harmless to human eyes, consists almost entirely of solid-state components, and offers high range resolution. Operates at wavelength of about 2 micrometers. If radiation from such device strikes eye, almost completely absorbed by cornea without causing damage, even if aimed directly at eye. Continuous-wave light from laser oscillator amplified and modulated for transmission from telescope. Small portion of output of oscillator fed to single-mode fiber coupler, where mixed with return pulses. Intended for remote Doppler measurements of winds and differential-absorption measurements of concentrations of gases in atmosphere.

  5. Initial Scaling Studies and Conceptual Thermal Fluids Experiments for the Prismatic NGNP Point Design

    Energy Technology Data Exchange (ETDEWEB)

    D. M. McEligot; G. E. McCreery

    2004-09-01

    The objective of this report is to document the initial high temperature gas reactor scaling studies and conceptual experiment design for gas flow and heat transfer. The general approach of the project is to develop new benchmark experiments for assessment in parallel with CFD and coupled CFD/ATHENA/RELAP5-3D calculations for the same geometry. Two aspects of the complex flow in an NGNP are being addressed: (1) flow and thermal mixing in the lower plenum ("hot streaking" issue) and (2) turbulence and resulting temperature distributions in reactor cooling channels ("hot channel" issue). Current prismatic NGNP concepts are being examined to identify their proposed flow conditions and geometries over the range from normal operation to decay heat removal in a pressurized cooldown. Approximate analyses are being applied to determine key non-dimensional parameters and their magnitudes over this operating range. For normal operation, the flow in the coolant channels can be considered to be dominant forced convection with slight transverse property variation. The flow in the lower plenum can locally be considered to be a situation of multiple buoyant jets into a confined density-stratified crossflow -- with obstructions. Experiments are needed for the combined features of the lower plenum flows. Missing from the typical jet experiments are interactions with nearby circular posts and with vertical posts in the vicinity of vertical walls - with near stagnant surroundings at one extreme and significant crossflow at the other. Two heat transfer experiments are being considered. One addresses the "hot channel" problem, if necessary. The second experiment will treat heated jets entering a model plenum. Unheated MIR (Matched-Index-of-Refraction) experiments are first steps when the geometry is complicated. One does not want to use a computational technique which will not even handle constant properties properly. The MIR experiment will simulate flow features of the paths of jets as they mix in flowing through the array of posts in a lower plenum en route to the single exit duct. Initial conceptual designs for such experiments are described.

  6. The life of a remedial design contractor (What it means to be first exclamation point)

    International Nuclear Information System (INIS)

    In August of 1990, the Department of Energy (DOE) awarded the Parsons Corporation a contract to perform architectural/engineering (A/E) remedial design (RD) services for the Fernald Environmental Management Project (FEMP). Complicating the implementation of the first RD contract were other contract firsts, such as (1) working initially under DOE as a prime contractor, then under a management and operations contractor as a subcontractor, and, currently, under an environmental restoration management contractor as a subcontractor; (2) operating under the then new DOE risk-sharing liability and indemnification regulation; and (3) operating under new, legally enforceable DOE nuclear safety regulations. In addition to these contract firsts. Were a number of funding and technical changes resulting from shifting priorities in the environmental program. These changes include (1) a decreased local emphasis on implementing innovative remediation technologies; (2) promoting ways to accomplish remedial activities faster, better, and cheaper without sacrificing safety; (3) a new emphasis on land use planning as a means of formulating cleanup levels; and (4) the increased involvement of the public

  7. Feasibility study of BWR-type reduced-moderation water reactor core design in thermal-hydraulic view point

    Energy Technology Data Exchange (ETDEWEB)

    Araya, Fumimasa; Kureta, Masatoshi; Akimoto, Hajime [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2000-10-01

    Conceptual design study has been performed at JAERI on advanced water-cooled reactors, namely reduced-moderation water reactors (RMWRs) which install plutonium mixed-oxide (MOX) fuel attaining the high conversion ratio around 1.0 and the negative void reactivity coefficient. The feasibility of three BWR-type RMWR cores have been investigated in the view points of thermal-hydraulics. All of these have tight lattice pitch fuel bundles for high conversion ratios. For confirming the feasibility of these core concepts, the transient thermal-hydraulic analysis code TRAC-BF1 was used in the study. Steady-state nominal operating conditions and flow reduction transient conditions were analyzed. In the analysis, only the core region was focused and the calculation conditions were controlled by boundary conditions based on the safety analysis of current BWRs, due that the coolant system design is underway. The calculated results showed that all of these concepts could be feasible in the thermal-hydraulic view points. (author)

  8. Dose effects of gamma radiation sterilization on antibiotic eye ointment

    International Nuclear Information System (INIS)

    Radiation effects of Co-60 gamma rays on some eye ointment base such as plastibase, cetyl alcohol, liquid paraffin, vaselin album, adeps lanae and tetracycline eye ointment in plastibase were examined by physico-chemical determinations. Parameters observed were color changes, pH, melting point, viscosity, iodine value, acid value and TLC, uv-spectrophotometric examination. Microbiological examinations were carried out to determine the degree of initial contamination of unirradiated eye ointment. Radiation dose used were radiation sterilization doses of 2 and 4 Mrad and storage time was 3 and 6 months. The results showed that the iodine value of tetracycline eye ointment in plastibase and eye ointment bases such as plastibase, vaselin album, liquid paraffin, cetyl alcohol, adeps lanae, changed significantly. Viscosity examination showed non-significant results, except for vaselin album and liquid paraffin irradiated at 4 Mrad. Microbiological examinations showed that some unirradiated eye ointment were contaminated by a few kinds of microbes. (author)

  9. Reevaluation of the AAPM TG-43 brachytherapy dosimetry parameters for an 125I seed, and the influence of eye plaque design on dose distributions and dose-volume histograms

    Science.gov (United States)

    Aryal, Prakash

    The TG-43 dosimetry parameters of the Advantage(TM) 125I model IAI-125A brachytherapy seed were studied. An investigation using modern MCNP radiation transport code with updated cross-section libraries was performed. Twelve different simulation conditions were studied for a single seed by varying the coating thickness, mass density, photon energy spectrum and cross-section library. The dose rate was found to be 6.3% lower at 1 cm in comparison to published results. New TG-43 dosimetry parameters are proposed. The dose distribution for a brachytherapy eye plaque, model EP917, was investigated, including the effects of collimation from high-Z slots. Dose distributions for 26 slot designs were determined using Monte Carlo methods and compared between the published literature, a clinical treatment planning system, and physical measurements. The dosimetric effect of the composition and mass density of the gold backing was shown to be less than 3%. Slot depth, width, and length changed the central axis (CAX) dose distributions by treatment planning software (version 5.7.6). The D10 for the simulated tumor, inner sclera, and outer sclera for the measured slot plaque to manufacturer provided slot design was 9%, 10%, and 19% higher, respectively. In comparison to the measured plaque design, a theoretical plaque having narrow and deep slots delivered 30%, 37%, and 62% lower D 10 doses to the tumor, inner sclera, and outer sclera, respectively. CAX doses at --1, 0, 1, and 2 mm were also lower by a factor of 2.6, 1.72, 1.50, and 1.39, respectively. The study identified substantial sensitivity of the EP917 plaque dose distributions to slot design. KEYWORDS: Monte Carlo methods, dosimetry, 125I, TG-43, eye plaque brachytherapy.

  10. The Cat's Eye Nebula

    Science.gov (United States)

    1994-01-01

    This NASA Hubble Space Telescope image shows one of the most complex planetary nebulae ever seen, NGC 6543, nicknamed the 'Cat's Eye Nebula.' Hubble reveals surprisingly intricate structures including concentric gas shells, jets of high-speed gas and unusual shock-induced knots of gas. Estimated to be 1,000 years old, the nebula is a visual 'fossil record' of the dynamics and late evolution of a dying star. A preliminary interpretation suggests that the star might be a double-star system. The suspected companion star also might be responsible for a pair of high-speed jets of gas that lie at right angles to this equatorial ring. If the companion were pulling in material from a neighboring star, jets escaping along the companion's rotation axis could be produced. These jets would explain several puzzling features along the periphery of the gas lobes. Like a stream of water hitting a sand pile, the jets compress gas ahead of them, creating the 'curlicue' features and bright arcs near the outer edge of the lobes. The twin jets are now pointing in different directions than these features. This suggests the jets are wobbling, or precessing, and turning on and off episodically. This color picture, taken with the Wide Field Planetary Camera-2, is a composite of three images taken at different wavelengths. (red, hydrogen-alpha; blue, neutral oxygen, 6300 angstroms; green, ionized nitrogen, 6584 angstroms). The image was taken on September 18, 1994. NGC 6543 is 3,000 light- years away in the northern constellation Draco. The term planetary nebula is a misnomer; dying stars create these cocoons when they lose outer layers of gas. The process has nothing to do with planet formation, which is predicted to happen early in a star's life.

  11. Overcoming Presbyopia by Manipulating the Eyes' Optics

    Science.gov (United States)

    Zheleznyak, Leonard A.

    Presbyopia, the age-related loss of accommodation, is a visual condition affecting all adults over the age of 45 years. In presbyopia, individuals lose the ability to focus on nearby objects, due to a lifelong growth and stiffening of the eye's crystalline lens. This leads to poor near visual performance and affects patients' quality of life. The objective of this thesis is aimed towards the correction of presbyopia and can be divided into four aims. First, we examined the characteristics and limitations of currently available strategies for the correction of presbyopia. A natural-view wavefront sensor was used to objectively measure the accommodative ability of patients implanted with an accommodative intraocular lens (IOL). Although these patients had little accommodative ability based on changes in power, pupil miosis and higher order aberrations led to an improvement in through-focus retinal image quality in some cases. To quantify the through-focus retinal image quality of accommodative and multifocal IOLs directly, an adaptive optics (AO) IOL metrology system was developed. Using this system, the impact of corneal aberrations in regard to presbyopia-correcting IOLs was assessed, providing an objective measure of through-focus retinal image quality and practical guidelines for patient selection. To improve upon existing multifocal designs, we investigated retinal image quality metrics for the prediction of through-focus visual performance. The preferred metric was based on the fidelity of an image convolved with an aberrated point spread function. Using this metric, we investigated the potential of higher order aberrations and pupil amplitude apodization to increase the depth of focus of the presbyopic eye. Thirdly, we investigated modified monovision, a novel binocular approach to presbyopia correction using a binocular AO vision simulator. In modified monovision, different magnitudes of defocus and spherical aberration are introduced to each eye, thereby taking advantage of the binocular visual system. Several experiments using the binocular AO vision simulator found modified monovision led to significant improvements in through-focus visual performance, binocular summation and stereoacuity, as compared to traditional monovision. Finally, we addressed neural factors, affecting visual performance in modified monovision, such as ocular dominance and neural plasticity. We found that pairing modified monovision with a vision training regimen may further improve visual performance beyond the limits set by optics via neural plasticity. This opens the door to an exciting new avenue of vision correction to accompany optical interventions. The research presented in this thesis offers important guidelines for the clinical and scientific communities. Furthermore, the techniques described herein may be applied to other fields of ophthalmology, such as childhood myopia progression.

  12. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... open and prevent the patient from blinking. A suction ring placed on the eye lifts and flattens ... may feel pressure from the eyelid holder and suction ring, similar to a finger pressed firmly on ...

  13. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Refractive Surgery & LASIK Sunglasses Living EyeSmart About Ophthalmologists Adults Under 40 Adults 40 to 60 Adults Over 60 Babies, Children & Teenagers Computer Usage Diabetes ...

  14. Therapy of Eye Cancer

    International Science & Technology Center (ISTC)

    Development and Creation of New Forms of Ophthalmology b - Applicators for Radiation Therapy of Eye Cancer and Study of Psycho-Physiological Effects on Man of Low Frequency Electromagnetic Radiation Emitted by Radio Nuclides.

  15. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... keep them open and prevent the patient from blinking. A suction ring placed on the eye lifts ... in the United States and the overall complication rate is low. Infection and inflammation are possibilities, as ...

  16. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... D. Enter your question here... Browse Top Answers > Privacy Policy > Featured Video LASIK (Femtosecond) 0:50 Free ... information about eye health and preserving your vision. Privacy Policy Email address

  17. What Is Dry Eye?

    Medline Plus

    Full Text Available ... information about eye health and preserving your vision. Privacy Policy Email address © 2015 American Academy of Ophthalmology medical disclaimer privacy policy sponsorship & advertising policies about us Educational Resources ...

  18. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... eye is numbed with a few drops of topical anesthetic. An eyelid holder is placed between the ... procedure, and usually can be cleared up with medications. Problems with the corneal flap after surgery sometimes ...

  19. Toxoplasmosis (and the Eye)

    Science.gov (United States)

    Toxoplasmosis Read in Chinese What is toxoplasmosis? Toxoplasmosis is an infection with the protozoan intracellular parasite Toxoplasma gondii. In the eye, Toxoplasma infections frequently cause significant inflammation and subsequent ...

  20. Dilating Eye Drops

    Science.gov (United States)

    American Association for Pediatric Ophthalmology and Strabismus Home About AAPOS Patient Info Resources Allied Health News & Events Meetings J AAPOS American Association for Pediatric Ophthalmology and Strabismus Eye Terms ...

  1. Aging and Your Eyes

    Science.gov (United States)

    ... be signs of more serious issues. Presbyopia (prez-bee-OH-pee-uh) is a slow loss of ... care professional may tell you to use a home humidifier, special eye drops (artificial tears), or ointments ...

  2. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... for sports and other activities can help prevent 90% of eye injuries. It's Not OK to Skip ... run the risk of being disappointed. More than 90 percent of people who have LASIK achieve somewhere ...

  3. Diabetic Eye Disease

    Science.gov (United States)

    ... Low Vision Education Program Spanish-language Education Program (¡Ojo con su visión!) Vision and Aging Program Training ... Eye Care En español La enfermedad diabética del ojo La enfermedad diabética del ojo ¿Cuánto sabe sobre ...

  4. Sydney Eye Hospital.

    OpenAIRE

    Price, L.

    1982-01-01

    This year, 1982, marks the centenary of the Sydney Eye Hospital, originally the ophthalmic department of the old Sydney Infirmary, which was founded with the settlement of the Colony in 1788. Established in 1882, the hospital was transferred to its present site 60 years ago, and it still provides ward accommodation. After alternating periods of stagnation and progress the new hospital (stage 1) was completed in 1974, with modern clinic and research facilities. It is now the largest eye hospit...

  5. Traffic engineering eye diagram

    OpenAIRE

    Kowalik, Karol; Collier, Martin

    2005-01-01

    It is said that a picture is worth a thousand words - this statement also applies to networking topics. Thus, to effectively monitor network performance we need tools which present the performance metrics in a graphical way which is also clear and informative. We propose a tool for this purpose which we call the traffic engineering eye diagram (TEED). Eye diagrams are used in digital communications to analyse the quality of a digital signal; the TEED can similarly he used in the traffic engin...

  6. The evolution of eyes.

    Science.gov (United States)

    Fernald, R D

    1997-01-01

    Eyes are the preeminent source of sensory information for the brain in most species, and many features of eyes reflect evolutionary solutions to particular selective pressures, both from the nonbiological environment and from other animals. As a result, the evolution of eyes, among all the sense organs, has attracted considerable attention from scientists. Paired eyes in the three major phyla, vertebrates, arthropods and mollusks, have long been considered to be classic examples of evolutionary convergence. At the macroscopic level, this must be true since they arise from different tissues and have evolved radically different solutions to the common problem of collecting and focusing light. However, opsin, the light-absorbing receptor protein, has a significant amount of shared DNA sequence homology across the phyla, and recently it has been discovered that some part of ocular development in different phyla is coordinated by a homologous, gene, Pax-6. So, although eyes from diverse phyla are clearly not homologous, neither can they be viewed as resulting solely from convergence. Instead, this shows that homology at the molecular level of organization does not predict homology at the organ or organismic level. The presence of homologous constituent molecules in nonhomologous structures reminds us that molecules are not eyes. PMID:9310200

  7. Reconstructing the eyes of Urbilateria.

    OpenAIRE

    Arendt, D.; Wittbrodt, J.

    2001-01-01

    The shared roles of Pax6 and Six homologues in the eye development of various bilaterians suggest that Urbilateria, the common ancestors of all Bilateria, already possessed some simple form of eyes. Here, we re-address the homology of bilaterian cerebral eyes at the level of eye anatomy, of eye-constituting cell types and of phototransductory molecules. The most widespread eye type found in Bilateria are the larval pigment-cup eyes located to the left and right of the apical organ in primary,...

  8. Effect of Education Sessions of a Structured School Eye Screening Programme on Indian Schoolteachers' Knowledge and Responsibility for Children's Eye Health

    Science.gov (United States)

    Thummalapalli, Rohit; Williams, Jachin D.; Khoshnood, Kaveh; Salchow, Daniel J.; Forster, Susan H.

    2013-01-01

    Objective: To evaluate the effect of education sessions on Indian schoolteacher awareness of childhood eye health issues, responsibility for children's eye health, and successful participation in a teacher-led eye screening health intervention programme in primary schools aimed at addressing avoidable childhood blindness in India. Design:…

  9. Design and Integration of an All-Magnetic Attitude Control System for FASTSAT-HSV01's Multiple Pointing Objectives

    Science.gov (United States)

    DeKock, Brandon; Sanders, Devon; Vanzwieten, Tannen; Capo-Lugo, Pedro

    2011-01-01

    The FASTSAT-HSV01 spacecraft is a microsatellite with magnetic torque rods as it sole attitude control actuator. FASTSAT s multiple payloads and mission functions require the Attitude Control System (ACS) to maintain Local Vertical Local Horizontal (LVLH)-referenced attitudes without spin-stabilization, while the pointing errors for some attitudes be significantly smaller than the previous best-demonstrated for this type of control system. The mission requires the ACS to hold multiple stable, unstable, and non-equilibrium attitudes, as well as eject a 3U CubeSat from an onboard P-POD and recover from the ensuing tumble. This paper describes the Attitude Control System, the reasons for design choices, how the ACS integrates with the rest of the spacecraft, and gives recommendations for potential future applications of the work.

  10. Identification system by eye retinal pattern

    International Nuclear Information System (INIS)

    Identification system by eye retinal pattern is introduced from the view-point of history of R and D, measurement, apparatus, evaluation tests, safety and application. According to our evaluation tests, enrolling time is approximately less than 1 min, verification time is a few seconds and false accept rate is 0 %. Evaluation tests at Sandia National Laboratories in USA show the comparison data of false accept rates such as 0 % for eye retinal pattern, 10.5 % for finger-print, 5.8 % for signature dynamics and 17.7 % for speaker voice. The identification system by eye retinal pattern has only three applications in Japan, but there has been a number of experience in USA. This fact suggests that the system will become an important means for physical protections not only in nuclear field but also in other industrial fields in Japan. (author)

  11. Design, simulation and fabrication of a novel contact-enhanced MEMS inertial switch with a movable contact point

    International Nuclear Information System (INIS)

    A novel inertial switch based on a micro-electro-mechanical system (MEMS) was designed, which consists of three main parts: a proof mass as the movable electrode, a cross beam as the stationary electrode and a movable contact point to prolong the contact time. A MATLAB/Simulink model, which had been verified by comparison with ANSYS transient simulation, was built to simulate the dynamic response, based on which the contact-enhancing mechanism was confirmed and the dependence of threshold acceleration on the proof mass thickness was studied. The simulated dynamic responses under various accelerations exhibit satisfactory device behaviors: the switch-on time is prolonged under transient acceleration; the switch-on state is more continuous than the conventional design under long lasting acceleration. The inertial micro-switch was fabricated by multilayer electroplating technology and then tested by a drop hammer experiment. The test results indicate that the contact effect was improved significantly and a steady switch-on time of over 50 µs was observed under half-sine wave acceleration with 1 ms duration, in agreement with the dynamic simulation

  12. Chemical treatment response to variations in non-point pollution water quality: results of a factorial design experiment.

    Science.gov (United States)

    Heiderscheidt, Elisangela; Leiviskä, Tiina; Kløve, Bjørn

    2015-03-01

    Chemical treatment of non-point derived pollution often suffers from undesirable oscillations in purification efficiency due to variations in runoff water quality. This study examined the response of the chemical purification process to variations in water quality using a 2(k) factorial design for runoff water rich in humic substances. The four k factors evaluated and the levels applied were: organic matter as dissolved organic carbon (DOC) (20-70 mg/L), suspended solids (SS) (10-60 mg/L), initial water pH (4.5-7), and applied coagulant dosage (ferric sulphate) (35-100 mg/L). Indicators of purification efficiency were residual concentration of DOC, SS and total phosphorus (tot-P). Analysis of variance and factor effect calculations showed that the initial DOC concentration in raw water samples and its interactions with the coagulant dosage applied exerted the most significant influence on the chemical purification process, substantially affecting the residual concentration of DOC, SS and tot-P. The variations applied to the factors SS and pH only slightly affected purification efficiency. The results can be used in the design of purification systems with high organic matter load variation, e.g. peat extraction runoff. PMID:25485936

  13. Sun, UV Radiation and Your Eyes

    Science.gov (United States)

    ... Screening Guidelines Home Remedies for Simple Eye Problems Medical Marijuana for Glaucoma Pregnancy Preventing Eye Injuries Smokers Sports Using Eye Makeup Veterans What Is an Ophthalmologist? Your Eyes & the Sun Eye Health News Consumer Alerts ... an Eye on Ultraviolet (UV) Safety Eye medical doctors (ophthalmologists) caution us that too much exposure ...

  14. Investigation of non-quarter wave design on multilayer optical thin film coatings from a heat transfer point of view

    Science.gov (United States)

    Ocak, Mustafa; Sert, Cüneyt; Okutucu, Tuba Ö.

    2013-11-01

    In this study multilayer thin film optical coatings, which are indispensable parts of optical systems are investigated from a heat transfer point of view. Laser irradiation induced temperature distribution on a multilayer coating stack is obtained by discretizing the heat diffusion equation using the finite volume method. In order to obtain mathematical representation of the energy flow and Electric Field Intensity (EFI) through the stack, Maxwell equations are solved by using the commercial software MacLeod®. Laser energy, which is absorbed by the multilayer stack in terms of heat, is calculated as a function of space and time by using the computed EFI, coating materials' optical properties and Gaussian laser beam parameters. Computed heat load is used in the finite volume solver ANSYS FLUENT® through a user defined function. Temperature distribution on a 19 layer HR multilayer coating stack irradiated by 1064 nm laser beam are obtained for both quarter wave and non-quarter wave designed configurations. Results of numerical simulations show that maximum temperature rise is seen in the first high index layer for quarter wave design (QWD). In addition to that, high temperatures are also seen in film/film interfaces, which is associated to both EFI distribution on the stack and wide differences in material properties between high and low index film layers. Non-quarter wave design (NQWD) is seen to be successful in decreasing temperatures at high index layers and at film/film interfaces. But it also changes the EFI distribution inside the multilayer stack, increasing absorbed laser energy and resulting in higher temperatures at modified low index layers.

  15. Wayfinding and eye movements

    Science.gov (United States)

    Kim, Nam-Gyoon

    1997-06-01

    During rectilinear locomotion, the focus of expansion identifies the observer's heading. Eye rotation or curvilinear locomotion annihilates this singularity. Computer simulations of eye rotation during circular translation present possible solutions to heading judgement. Specifically, when gaze direction coincides with circular heading, every velocity vector in the image plane becomes linearized. These velocity vectors are tangent vectors of the corresponding flow lines of optical flow. Moreover, the vectors corresponding to the observer's path are all aligned perpendicularly in the image plane, which in turn can be used to determine the observer's path of locomotion.

  16. Photorefraction of the Eye

    Science.gov (United States)

    Colicchia, Giuseppe; Wiesner, Hartmut; Zollman, Dean

    2015-02-01

    Photorefraction is a method to easily estimate the refractive state of the eye. The principle of photorefraction involves projecting light into the eye during flash photography and then examining the paths of light that emerge from the pupil after scattering on the back portion of the interior of the eyeball (fundus). We will explain the optical principles underlying the method for eccentric photorefraction and describe how students can perform it using current digital cameras. Our purpose is not to diagnose refractive errors reliably, but to use devices popular among young people that, in combination with an important ophthalmic context, may be successful in improving students' interest for learning optical concepts.

  17. Hand-eye Calibration

    OpenAIRE

    Horaud, Radu; Dornaika, Fadi

    1995-01-01

    Whenever a sensor is mounted on a robot hand, it is important to know the relationship between the sensor and the hand. The problem of determining this relationship is referred to as the hand-eye calibration problem. Hand-eye calibration is impor tant in at least two types of tasks: (1) map sensor centered measurements into the robot workspace frame and (2) tasks allowing the robot to precisely move the sensor. In the past some solutions were proposed, particularly in the case of the sensor b...

  18. The Tehran Eye Study: research design and eye examination protocol

    OpenAIRE

    Fotouhi Akbar; Hashemi Hassan; Mohammad Kazem

    2003-01-01

    Abstract Background Visual impairment has a profound impact on society. The majority of visually impaired people live in developing countries, and since most disorders leading to visual impairment are preventable or curable, their control is a priority in these countries. Considering the complicated epidemiology of visual impairment and the wide variety of factors involved, region specific intervention strategies are required for every community. Therefore, providing appropriate data is one o...

  19. Differences in saccade-evoked brain activation patterns with eyes open or eyes closed in complete darkness.

    Science.gov (United States)

    Hüfner, K; Stephan, T; Glasauer, S; Kalla, R; Riedel, E; Deutschländer, A; Dera, T; Wiesmann, M; Strupp, M; Brandt, T

    2008-04-01

    In this study we attempted to differentiate distinct components of the saccade network, namely cortical ocular motor centers and parieto-occipital brain regions, by means of a "minimal design" approach. Using a blocked design fMRI paradigm we evaluated the BOLD changes in a 2 x 2 factorial design experiment which was performed in complete darkness: while looking straight ahead with eyes open (OPEN) or closed (CLOSED) as well as during the execution of self-initiated horizontal to-and-fro saccades with the eyes open (SACCopen) or closed (SACCclosed). Eye movements were monitored outside the scanner via electro-oculography and during scanning using video-oculography. Unintentional eye-drifts did not differ during OPEN and CLOSED and saccade frequencies, and amplitudes did not vary significantly between the two saccade conditions. The main findings of the functional imaging study were as follows: (1) Saccades with eyes open or closed in complete darkness lead to distinct differences in brain activation patterns. (2) A parieto-occipital brain region including the precuneus, superior parietal lobule, posterior part of the intraparietal sulcus (IPS), and cuneus was relatively deactivated during saccades performed with eyes closed but not during saccades with eyes open or when looking straight ahead. This could indicate a preparatory state for updating spatial information, which is active during saccades with eyes open even without actual visual input. The preparatory state is suppressed when the eyes are closed during the saccades. (3) Selected ocular motor areas, not including the parietal eye field (PEF), show a stronger activation during SACCclosed than during SACCopen. The increased effort involved in performing saccades with eyes closed, perhaps due to the unusualness of the task, may be the cause of this increased activation. PMID:18183378

  20. A nanoparticle formulation reduces the corneal toxicity of indomethacin eye drops and enhances its corneal permeability.

    Science.gov (United States)

    Nagai, Noriaki; Ito, Yoshimasa; Okamoto, Norio; Shimomura, Yoshikazu

    2014-05-01

    Indomethacin (IMC) has been shown to reduce post-operative inflammation and to decrease intraocular irritation after cataract extraction and in cystoid macular edema; however, the clinical use of its most commonly used eye drops is limited due to topical side-effects that include burning sensation, irritation and epithelial keratitis. It is known that decreasing direct cell stimulation and reducing the amount applied via increasing bioavailability are useful for improving these issues. In this study, we designed ophthalmic formulations containing 0.5% IMC nanoparticles using zirconia beads and Bead Smash 12 (IMCnano eye drops; particle size 76 ± 59 nm, mean ± S.D.), and investigated the corneal toxicity of these IMCnano eye drops. IMCnano eye drops are tolerated better by a human cornea epithelial cell line (HCE-T) than commercially available NDSAIDs preparations (IMC, pranoprofen, diclofenac, bromfenac and nepafenac eye drops), and corneal wound healing in rat eyes with debrided corneal epithelium instilled with IMCnano eye drops is significantly better than that of eyes instilled with commercially available IMC eye drops. In addition, the accumulation of IMC in HCE-T cells treated with the IMCnano eye drops for 30 min was 19.9% that of the accumulation from commercially available IMC eye drops. On the other hand, the corneal penetration of IMC from IMCnano eye drops was significantly greater than in the case of the commercially available IMC eye drops in both in vivo and in vitro studies using rabbit corneas. Taken together, we hypothesize that a nanoparticle formulation reduces the corneal toxicity of IMC eye drops, probably because the accumulation of IMC from IMCnano eye drops in the eye is lower than that from commercially available IMC eye drops. In addition, the nanoparticle formulation may allow a decrease in the amount of IMC used due to the increase in bioavailability, resulting in reduced drug toxicity. These findings provide significant information that can be used to design further studies aimed at developing less toxic eye drops. PMID:24598350

  1. Through Our Eyes

    Science.gov (United States)

    Narva, Sara

    2009-01-01

    Through Our Eyes was a multimedia performance created in collaboration with the author's five modern dance students. Through video, sound, and dance, the piece shows some ways race has affected their lives. The author did not set out at the beginning of the semester to make this project in her dance class. It was born out of a hard conversation,…

  2. Eye Disease and Development

    DEFF Research Database (Denmark)

    Andersen, Thomas Barnebeck; Dalgaard, Carl-Johan Lars

    2011-01-01

    This research advances the hypothesis that cross-country variation in the historical incidence of eye disease has influenced the current global distribution of per capita income. The theory is that pervasive eye disease diminished the incentive to accumulate skills, thereby delaying the fertility transition and the take-off to sustained economic growth. In order to estimate the influence from eye disease incidence empirically, we draw on an important fact from the field of epidemiology: Exposure to solar ultraviolet B radiation (UVB-R) is an underlying determinant of several forms of eye disease; the most important being cataract, which is currently the leading cause of blindness worldwide. Using a satellite-based measure of UVB-R, we document that societies more exposed to UVB-R are poorer and underwent the fertility transition with a significant delay compared to the forerunners. These findings are robust to the inclusion of an extensive set of climate and geography controls. Moreover, using a global data set on economic activity for all terrestrial grid cells we show that the link between UVB-R and economic development survives the inclusion of country fixed effect.

  3. Eye of the Beholder

    Science.gov (United States)

    Rogers, Michael

    2010-01-01

    Art, like beauty, as the adage goes, is in the eye of the beholder. Art also is a living, breathing thing that evolves over time, so what is considered "art" is ever changing--how many of the great artists whose works today sell for fortunes were failures during their lifetime? The 20th century unknowingly gave birth to new variations of art that…

  4. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... Don’t Mix To help prevent eye infections, contact lenses should be removed before going swimming or in ... 20 and 20/40 vision without glasses or contact lenses. If sharp, detailed 20/20 vision is essential ...

  5. If I Had - Dry Eyes

    Medline Plus

    Full Text Available ... I Had - Dry Eyes - Dr. Penny Asbell, MD, FACS, MBA, Professor of Ophthalmology, Mount Sinai School of ... I Had - Dry Eyes - Dr. Penny Asbell, MD, FACS, MBA, Professor of Ophthalmology, Mount Sinai School of ...

  6. If I Had - Dry Eyes

    Medline Plus

    Full Text Available ... with Severe COPD VIDEO: If I Had - Dry Eyes - Dr. Penny Asbell, MD, FACS, MBA, Professor of ... to Home Page VIDEO: If I Had - Dry Eyes - Dr. Penny Asbell, MD, FACS, MBA, Professor of ...

  7. If I Had - Dry Eyes

    Science.gov (United States)

    ... Had - Dry Eyes - Dr. Penny Asbell, MD, FACS, MBA, Professor of Ophthalmology, Mount Sinai School of Medicine, ... Had - Dry Eyes - Dr. Penny Asbell, MD, FACS, MBA, Professor of Ophthalmology, Mount Sinai School of Medicine, ...

  8. If I Had - Dry Eyes

    Medline Plus

    Full Text Available ... Had - Dry Eyes - Dr. Penny Asbell, MD, FACS, MBA, Professor of Ophthalmology, Mount Sinai School of Medicine, ... Had - Dry Eyes - Dr. Penny Asbell, MD, FACS, MBA, Professor of Ophthalmology, Mount Sinai School of Medicine, ...

  9. Enhancing eye donation rates. Training students to be motivators

    Directory of Open Access Journals (Sweden)

    Dhaliwal Upreet

    2002-01-01

    Full Text Available Purpose: Medical professionals could enhance eye donation rates by reminding relatives during grief counseling at the time of patient?s death. This study was designed to assess the knowledge and attitudes of final year medical students (future doctors towards eye donation, prior to instruction in eye banking. Methods: The responses of 49 final-year medical students to a questionnaire on eye donation were compared with 24 non-medical students (controls. The results were analysed statistically using the chi-square test. Results: More than one-third of students and controls were unaware that eyes are removed within six hours of death. Eight (16.3% students and 6 (25.0% controls felt that a close relative?s eyes could be donated after death only if he had indicated willingness (P=0.05. Three (6.1% students and 3 (12.5% controls were undecided about donating their own eyes. Nineteen (38.8% students and 6 (25% controls did not know where to go in order to pledge/donate eyes. The controls had poorer knowledge of ocular and systemic contraindications, and they did not know that storage could be prolonged (PConclusions: Controls were poorly informed about various aspects of eye donation suggesting inadequate dissemination of information by the media. Students and controls alike had misconceptions regarding donation of relatives? eyes and hesitation regarding their own. These aspects should be emphasized during undergraduate teaching to dispel misgivings regarding wastage of donor eyes and to encourage future doctors to promote eye donation.

  10. Are 3-D Movies Bad for Your Eyes?

    Medline Plus

    Full Text Available ... D Movies Bad for Your Eyes? Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During ... Eye Protection Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Water & Contacts Don’ ...

  11. Choosing Wisely When It Comes to Eye Care: Antibiotics for Pink Eye

    Science.gov (United States)

    ... Consumer Alerts Choosing Wisely When It Comes to Eye Care Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes ... over the battery and always wear safety goggles. Eye Protection Works Wearing the proper protective eyewear for ...

  12. Eye preferences in captive chimpanzees

    OpenAIRE

    Braccini, Stephanie N.; Lambeth, Susan P.; Schapiro, Steven J.; Fitch, W. Tecumseh

    2012-01-01

    Over the last century, the issue of brain lateralization in primates has been extensively investigated and debated, yet no previous study has reported eye preference in great apes. This study examined eye preference in 45 captive chimpanzees (Pan troglodytes) in response to various stimuli. Eye preference was assessed when animals looked through a hole that only accommodated one eye at an empty box, a mirror, a picture of a dog, a rubber snake, food biscuits, bananas, a rubber duck, and a vid...

  13. Pink Eye: What To Do

    Centers for Disease Control (CDC) Podcasts

    2010-10-12

    In this podcast, CDC's Adam Cohen, MD, a pediatrician and parent, discusses conjunctivitis (pink eye), a common eye condition in children and adults. He reviews pink eye causes and treatment, suggestions on when to call or visit a doctor, and practical tips to prevent pink eye from spreading.  Created: 10/12/2010 by National Center for Immunization and Respiratory Diseases (NCIRD).   Date Released: 10/13/2010.

  14. Optimization of the 3-Point Bending Failure of Anodized Aluminum Formed in Tartaric/Sulphuric Acid Using Doehlert Design

    Science.gov (United States)

    Bensalah, W.; Feki, M.; De-Petris Wery, M.; Ayedi, H. F.

    2015-02-01

    The bending failure of anodized aluminum in tartaric/sulphuric acid bath was modeled using Doehlert design. Bath temperature, anodic current density, sulphuric acid, and tartaric acid concentrations were retained as variables. Thickness measurements and 3-point bending experiments were conducted. The deflection at failure ( D f) and the maximum load ( F m) of each sample were, then, deducted from the corresponding flexural responses. The treatment of experimental results has established mathematical models of second degree reflecting the relation of cause and effect between the factors and the studied properties. The optimum path study of thickness, deflection at failure, and maximum load, showed that the three optima were opposite. Multicriteria optimization using the desirability function was achieved in order to maximize simultaneously the three responses. The optimum conditions were: C tar = 18.2 g L-1, T = 17.3 °C, J = 2.37 A dm-2, C sul = 191 g L-1, while the estimated response values were e = 57.7 µm, D f = 5.6 mm, and F m = 835 N. Using the established models, a mathematical correlation was found between deflection at failure and thickness of the anodic oxide layer. Before bending tests, aluminum oxide layer was examined by scanning electron microscopy (SEM) and atomic force microscopy. After tests, the morphology and the composition of the anodic oxide layer were inspected by SEM, optical microscopy, and glow-discharge optical emission spectroscopy.

  15. Design of set-point weighting PI? + D? controller for vertical magnetic flux controller in Damavand tokamak

    Science.gov (United States)

    Rasouli, H.; Fatehi, A.

    2014-12-01

    In this paper, a simple method is presented for tuning weighted PI? + D? controller parameters based on the pole placement controller of pseudo-second-order fractional systems. One of the advantages of this controller is capability of reducing the disturbance effects and improving response to input, simultaneously. In the following sections, the performance of this controller is evaluated experimentally to control the vertical magnetic flux in Damavand tokamak. For this work, at first a fractional order model is identified using output-error technique in time domain. For various practical experiments, having desired time responses for magnetic flux in Damavand tokamak, is vital. To approach this, at first the desired closed loop reference models are obtained based on generalized characteristic ratio assignment method in fractional order systems. After that, for the identified model, a set-point weighting PI? + D? controller is designed and simulated. Finally, this controller is implemented on digital signal processor control system of the plant to fast/slow control of magnetic flux. The practical results show appropriate performance of this controller.

  16. Eye Pupil Location Using Webcam

    CERN Document Server

    Ciesla, Michal

    2012-01-01

    Three different algorithms used for eye pupil location were described and tested. Algorithm efficiency comparison was based on human faces images taken from the BioID database. Moreover all the eye localisation methods were implemented in a dedicated application supporting eye movement based computer control. In this case human face images were acquired by a webcam and processed in a real-time.

  17. Carotid Artery and the Eye

    Science.gov (United States)

    ... How to Help The Carotid Artery and the Eye Share with a friend The Carotid Artery and the Eye A link to this article will be included ... Give Us Feedback The Carotid Artery and the Eye Your name First Name MI Laast Name Your ...

  18. Introduction to Symptoms of Eye Disorders

    Science.gov (United States)

    ... Resources for Help and Information The One-Page Merck Manual of Health Medical Terms Conversion Tables Manuals ... the Eyes Vision Loss, Sudden Other Eye Symptoms Merck Manual > Patients & Caregivers > Eye Disorders > Symptoms of Eye ...

  19. Contact Lens-Related Eye Infections

    Science.gov (United States)

    ... Eyes & the Sun Eye Health News Consumer Alerts Contact Lens-Related Eye Infections Tweet While contact lenses are ... eye infection. The most common infection related to contact lens use is keratitis, an infection of the cornea ( ...

  20. Comparison of eye shields in radiotherapeutic beams

    International Nuclear Information System (INIS)

    Full text: Both MeV electrons and kV photons are used in the treatment of superficial cancers. The advantages and disadvantages for each of these modalities have been widely reported in the literature (See for example [1-2]). Of particular note in the literature is the use of lead and tungsten eye shields to protect ocular structures during radiotherapy. An investigation addressing issues raised in the literature that are relevant to the Wellington Cancer Centre method of treatment of lesions near the eye shall be summarised. Various small sized fields were irradiated to determine depth dose and profile curves in a water phantom shielded by various commercially available eye shields. Transmission factors relevant to critical ocular structures and particle distribution theories are used to further elucidate the comparison between the use of MeV electrons and kV photons in the treatment of superficial cancers. Superficial X-rays from a Pantak Therapax unit SXT 150 model of HVL 4.90mm Al were used for the lead eye shield measurements and electrons from a Varian Clinac 2100C nominal energies 6MeV and 9MeV (Rp 3.00cm and 4.34cm respectively) were used for the tungsten eye shield measurements. For the photon measurements circular applicators of 3cm, 4cm and 5cm diameter were used and for the electrons standard 6x6cm and 10x 10cm applicators were used, with no custom inserts. A Scanditronix RFA-300 water phantom and Scanditronix RFAplus version 5.3 software applictronix RFAplus version 5.3 software application were used to collect and collate all data. The eye shields were the Radiation Products Design Inc. medium lead eye shield (item 934-014) and the MED-TEC tungsten eye shields MT-T-45 M and MT-T-45 S. It is demonstrated that electron fields have appreciably greater scatter into the area directly under the eye shields than the photon fields. Similarly at the region of dmax for the electron fields the relative dose is appreciably greater than the photon fields at similar depth. The relative merits for electron and photon treatments are discussed with respect to the investigations findings and reference to the literature. When comparing electrons and photons it is usually the definite range of electrons within tissue that recommends electron treatments. However, one should weigh this consideration against some of the salient features of a well-constructed superficial photon treatment, for example the effective blocking of kilovoltage photons by lead and the sharp edges of the kilovoltage photon fields. Copyright (2004) Australasian College of Physical Scientists and Engineers in Medicine

  1. Genetic analyses of the human eye colours using a novel objective method for eye colour classification

    DEFF Research Database (Denmark)

    Andersen, Jeppe D.; Johansen, Peter

    2013-01-01

    In this study, we present a new objective method for measuring the eye colour on a continuous scale that allows researchers to associate genetic markers with different shades of eye colour. With the use of the custom designed software Digital Iris Analysis Tool (DIAT), the iris was automatically identified and extracted from high resolution digital images. DIAT was made user friendly with a graphical user interface. The software counted the number of blue and brown pixels in the iris image and calculated a Pixel Index of the Eye (PIE-score) that described the eye colour quantitatively. The PIE-score ranged from ?1 to 1 (brown to blue). The software eliminated the need for user based interpretation and qualitative eye colour categories. In 94% (570) of 605 analyzed eye images, the iris region was successfully extracted and a PIE-score was calculated. A very high correlation between the PIE-score and the human perception of eye colour was observed. The correlations between the PIE-scores and the six IrisPlexSNPs (HERC2 rs12913832, OCA2 rs1800407, SLC24A4 rs12896399, TYR rs1393350, SLC45A2 rs16891982 and IRF4 rs12203592) were analyzed in 570 individuals. Significant differences (p < 10?6) in the PIE-scores of the individuals typed as HERC2 rs12913832 G (PIE = 0.99) and rs12913832 GA (PIE = ?0.71) or A (PIE = ?0.87) were observed. We adjusted for the effect of HERC2 rs12913832 and showed that the quantitative PIE-scores were significantly associated with SNPs with minor effects (OCA2 rs1800407, SLC24A4 rs12896399 and TYR rs1393350) on the eye colour. We evaluated the two published prediction models for eye colour (IrisPlex [1] and Snipper[2]) and compared the predictions with the PIE-scores. We found good concordance with the prediction from individuals typed as HERC2 rs12913832 G. However, both methods had difficulties in categorizing individuals typed as HERC2 rs12913832 GA because of the large variation in eye colour in HERC2 rs12913832 GA individuals. With the use of the DIAT software and the PIE-score, it will be possible to automatically compare the iris colour of large numbers of iris images obtained by different studies and to perform large meta-studies that may reveal loci with small effects on the eye colour.

  2. An Eye Detection Algorithm Using Pixel to Edge Information

    OpenAIRE

    Asteriadis, S.; Nikolaidis, N.; Hajdu, A.; Pitas, I.

    2010-01-01

    We present a new method for eyes localization on a face, based only on geometrical information. A face detector is applied first to detect the bounding box of the face, and the edge map is extracted. A vector is assigned to every pixel, pointing to the closest edge pixel. Length and slope information for these vectors is consequently used to detect and localize the eyes. The method has been tested on two face databases with very good results.

  3. Robust Eye and Pupil Detection Method for Gaze Tracking

    OpenAIRE

    Su Yeong Gwon; Chul Woo Cho; Hyeon Chang Lee; Won Oh Lee; Kang Ryoung Park

    2013-01-01

    Robust and accurate pupil detection is a prerequisite for gaze detection. Hence, we propose a new eye/pupil detection method for gaze detection on a large display. The novelty of our research can be summarized by the following four points. First, in order to overcome the performance limitations of conventional methods of eye detection, such as adaptive boosting (Adaboost) and continuously adaptive mean shift (CAMShift) algorithms, we propose adaptive selection of the Adaboost and CAMShift met...

  4. Incorporation of intraocular scattering in schematic eye models.

    Science.gov (United States)

    Navarro, R

    1985-11-01

    Beckmann's theory of scattering from rough surfaces is applied to obtain, from the experimental veiling glare functions, a diffuser that when placed at the pupil plane would produce the same scattering halo as the ocular media. This equivalent diffuser is introduced in a schematic eye model, and its influence on the point-spread function and the modulation-transfer function of the eye is analyzed. PMID:4067695

  5. Incorporation of intraocular scattering in schematic eye models

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, R.

    1985-11-01

    Beckmann's theory of scattering from rough surfaces is applied to obtain, from the experimental veiling glare functions, a diffuser that when placed at the pupil plane would produce the same scattering halo as the ocular media. This equivalent diffuser is introduced in a schematic eye model, and its influence on the point-spread function and the modulation-transfer function of the eye is analyzed.

  6. Incorporation of intraocular scattering in schematic eye models

    International Nuclear Information System (INIS)

    Beckmann's theory of scattering from rough surfaces is applied to obtain, from the experimental veiling glare functions, a diffuser that when placed at the pupil plane would produce the same scattering halo as the ocular media. This equivalent diffuser is introduced in a schematic eye model, and its influence on the point-spread function and the modulation-transfer function of the eye is analyzed

  7. Eye-Tracking Measures Reveal How Changes in the Design of Aided AAC Displays Influence the Efficiency of Locating Symbols by School-Age Children without Disabilities

    Science.gov (United States)

    Wilkinson, Krista M.; O'Neill, Tara; McIlvane, William J.

    2014-01-01

    Purpose: Many individuals with communication impairments use aided augmentative and alternative communication (AAC) systems involving letters, words, or line drawings that rely on the visual modality. It seems reasonable to suggest that display design should incorporate information about how users attend to and process visual information. The…

  8. Eye movement abnormalities.

    Science.gov (United States)

    Moncayo, Jorge; Bogousslavsky, Julien

    2012-01-01

    Generation and control of eye movements requires the participation of the cortex, basal ganglia, cerebellum and brainstem. The signals of this complex neural network finally converge on the ocular motoneurons of the brainstem. Infarct or hemorrhage at any level of the oculomotor system (though more frequent in the brain-stem) may give rise to a broad spectrum of eye movement abnormalities (EMAs). Consequently, neurologists and particularly stroke neurologists are routinely confronted with EMAs, some of which may be overlooked in the acute stroke setting and others that, when recognized, may have a high localizing value. The most complex EMAs are due to midbrain stroke. Horizontal gaze disorders, some of them manifesting unusual patterns, may occur in pontine stroke. Distinct varieties of nystagmus occur in cerebellar and medullary stroke. This review summarizes the most representative EMAs from the supratentorial level to the brainstem. PMID:22377853

  9. Library design using BCUT chemistry-space descriptors and multiple four-point pharmacophore fingerprints: simultaneous optimization and structure-based diversity.

    Science.gov (United States)

    Mason, J S; Beno, B R

    2000-01-01

    New applications of fingerprints of multiple potential 4-point three-dimensional (3D) pharmacophores in combinatorial library design and virtual screening are presented. Preliminary results demonstrating the feasibility of a simulated annealing process for combinatorial reagent selection that concurrently optimizes product diversity in BCUT chemistry space and in terms of unique 4-point pharmacophores are discussed, and the advantage of using a customized chemistry-space derived for the library design is demonstrated. In addition, an extension to the multiple pharmacophore method for structure-based design that uses the shape of the target site as an additional constraint is presented. This development enables the docking process to be quantified in terms of the number and identities of the pharmacophoric hypotheses that can be matched by a compound or a library of compounds. The design of an example combinatorial library based on the Ugi condensation reaction and a serine protease active site is described. PMID:11143561

  10. The analysis of visual variables for use in the cartographic design of point symbols for mobile Augmented Reality applications

    Science.gov (United States)

    Halik, ?ukasz

    2012-11-01

    The objective of the present deliberations was to systematise our knowledge of static visual variables used to create cartographic symbols, and also to analyse the possibility of their utilisation in the Augmented Reality (AR) applications on smartphone-type mobile devices. This was accomplished by combining the visual variables listed over the years by different researchers. Research approach was to determine the level of usefulness of particular characteristics of visual variables such as selective, associative, quantitative and order. An attempt was made to provide an overview of static visual variables and to describe the AR system which is a new paradigm of the user interface. Changing the approach to the presentation of point objects is caused by applying different perspective in the observation of objects (egocentric view) than it is done on traditional analogue maps (geocentric view). Presented topics will refer to the fast-developing field of cartography, namely mobile cartography. Particular emphasis will be put on smartphone-type mobile devices and their applicability in the process of designing cartographic symbols. Celem artyku?u by?o usystematyzowanie wiedzy na temat statycznych zmiennych wizualnych, które sa kluczowymi sk?adnikami budujacymi sygnatury kartograficzne. Podjeto próbe zestawienia zmiennych wizualnych wyodrebnionych przez kartografów na przestrzeni ostatnich piecdziesieciu lat, zaczynajac od klasyfikacji przedstawionej przez J. Bertin’a. Dokonano analizy stopnia uzytecznosci poszczególnych zmiennych graficznych w aspekcie ich wykorzystania w projektowaniu znaków punktowych dla mobilnych aplikacji tworzonych w technologii Rzeczywistosci Rozszerzonej (Augmented Reality). Zmienne poddano analizie pod wzgledem czterech charakterystyk: selektywnosci, skojarzeniowosci, odzwierciedlenia ilosci oraz porzadku. W artykule zwrócono uwage na odmienne zastosowanie perspektywy pomiedzy tradycyjnymi analogowymi mapami (geocentrycznosc) a aplikacjami tworzonymi w technologii Rozszerzonej Rzeczywistosci (egocentrycznosc). Tresci prezentowane w pracy dotycza szybko rozwijajacej sie ga?ezi kartografii - kartografii mobilnej. Dodatkowy nacisk po?ozony zosta? na próbe implementacji za?ozen projektowania punktowych znaków kartograficznych na urzadzenia mobilne typu smartphone.

  11. Obesity and Eye Diseases

    OpenAIRE

    Cheung, Ning; Wong, Tien Y.

    2007-01-01

    The prevalence of obesity has reached epidemic proportions in many countries. While its impact on overall health is well documented, less is known about the ocular manifestations of obesity. Amongst different eye diseases, obesity has been linked with age-related cataract, glaucoma, age-related maculopathy, and diabetic retinopathy. Numerous population-based and prospective studies support an association between obesity and risk of age-related cataract. However, the nature and strength of the...

  12. Eye in the Sky

    Science.gov (United States)

    This National Geographic website highlights the history and use of satellites and remote-sensing technology to determine the state of the planet. A timeline covers the history of satellites from 1858 to 2000, including both accomplishments and failures. The Eye contains slide shows and images from satellites covering the topics of volcanoes, tornadoes, hurricanes, wildfires, earthquakes, floods, dams, ozone, deforestation, desertification, overpopulation, exploration of space, and human conflict. A section on classroom ideas provides activities for K-12 classrooms.

  13. Michelangelo's eye disease.

    Science.gov (United States)

    Gallenga, P E; Neri, Giampiero; D'Anastasio, Ruggero; Pettorrossi, Vito Enrico; Alfieri, Emilio; Capasso, Luigi

    2012-06-01

    Charged by the Pope Julius II for painting the Cappella Sistina in Rome (between 1508 and 1512), Michelangelo worked in an elevated scaffolding, in an anomalous position with dyes (including poisoning lead salts) and solvents (such as toxic turpentine) dripping on his face and continuously inhaling, in a dim environment illuminated only with oil lamps and candles, as he described himself and sketched in a sonet addressed to Giovanni da Pistoia. In 1510 he began suffering from eye disease: the main symptom was the necessity to elevate the document he was reading up to the level of his eyes. This defect disappeared few months after he finished painting his masterpiece. We hypothesize that the Michelangelo's eyes disease was a form of acquired and transitory nystagmus induced by the many hours he spent in up gaze, with a skew deviation, a form of ocular tilt reaction resulting from the impairment of spatial sensitivity (inversion illusion) due to the persistence of the artist's head in a horizontal position, looking upward. PMID:22425178

  14. Design and implementation of a dedicated calorimeter for long stem SPRTs calibrations at the argon and oxygen triple points

    Science.gov (United States)

    Didi-Alaoui, I.; Fiorillo, D.; Vergé, A.; Sparasci, F.; Jouin, D.; Hermier, Y.

    2013-09-01

    Most of the thermometers used for the dissemination of the International Temperature Scale of 1990 (ITS-90) to the industry are long-stem Standard Platinum Resistance Thermometers (SPRTs). In the low temperature range, they are generally used from the triple point of water (273.16 K) down to the triple point of argon (83.805 8 K). The lack of equipment for routinely calibrating thermometers below 83 K (except comparisons at the nitrogen boiling point) limits their use at lower temperatures. The LNE-Cnam has recently developed an innovative calorimeter to improve the calibration of long-stem SPRTs at the triple point of argon and to extend the calibration range down to the oxygen triple point (54.358 4 K). Results show that at the argon triple point further investigations are needed to ascertain a reduction of the calibration uncertainty, with respect to the previous system developed by the laboratory. At the oxygen triple point, uncertainties are below the millikelvin level. With this device, the LNE-Cnam acquires the possibility to improve its calibration uncertainties for long-stem SPRTs at the argon triple point, and extends its calibration capabilities down to the triple point of oxygen.

  15. What is eye safe?

    Science.gov (United States)

    Franks, James K.

    1991-04-01

    Manufacturers have referred to lasers with operating wavelengths longer than 1400 nm (mid to far infrared) as eyesafe. Wavelengths in this region are absorbed in anterior portions of the eye (mainly cornea) and therefore never reach the retina. This is in contrast to the eye- hazardous portion of the optical spectrum of 400 - 1400 nm (visible and near infrared) where the anterior portions of the eye have high transmittance and refractive power. Irradiance levels are typically 5 orders of magnitude greater at the retina than at the cornea for visible and NIR wavelengths. Although wavelengths longer than 1400 nm do not interact with the retina, they can interact with the skin or cornea and cause a thermal injury. Specifiers of laser equipment have required that systems be eyesafe at a particular distance with or without optics. By this they mean that exposure at that distance for the naked eye or optically aided viewing through a specified power of optics should not exceed exposure limits. Some wavelengths in the visible and near IR are more 'eyesafe' than others because the safety factor between the level that would actually produce an injury (ED-50 value) and the exposure limit is greater. For example, the ED-50 value for a single Q-switched laser pulse for the ruby laser wavelength of 694.3 nm is 11.2 (mu) J into the eye and the Accessible Emission Limit (AEL) is 0.19 (mu) J, a factor of 59 between ED-50 and the AEL. The ratio for 1064 nm for a single Q- switched pulse is 99 (mu) J/1.9 (mu) J or 52. So, in a sense, exposure to 694 laser radiation at the AEL, is slightly more 'eyesafe' than exposure to 1064 nm radiation at the AEL. To the laser safety specialist, however, eyesafe, means only one thing, Class 1. Class 1 is a laser hazard classification that means the laser does not exceed specified limits for a reasonable, worst-case combination of distance, exposure duration, and collecting aperture diameter during its intended use. Determining whether a laser is Class 1 is usually a two-step process. The first step is determination of the AEL and the second is determining whether or not the laser in question exceeds this AEL. Exceeding the AEL is determined by calculation or measurement. If the AEL is exceeded under prescribed parameters then the laser is not Class 1. Differences in laser safety standards in both of these classification steps have caused confusion. Differences in exposure limits chosen by laser safety specialists based upon the same criteria have also caused confusion.

  16. More Than Meets the Eye The Genetics of Eye Color

    Science.gov (United States)

    Annie Prud?homme Genereux

    2011-01-01

    The genetics of eye color are more complex than commonly believed. This interrupted case study uses the story of a blue-eyed couple with a brown-eyed child to explore the possible scenarios that could result in this outcome. The case emphasizes the link between Mendelian genetics and the underlying molecular basis of the phenotype. It is appropriate for upper-level undergraduate biology majors with a good understanding of eukaryotic gene regulation and Mendelian genetics.

  17. The fly's eye camera system

    Science.gov (United States)

    Mészáros, L.; Pál, A.; Csépány, G.; Jaskó, A.; Vida, K.; Oláh, K.; Mezö, G.

    2014-12-01

    We introduce the Fly's Eye Camera System, an all-sky monitoring device intended to perform time domain astronomy. This camera system design will provide complementary data sets for other synoptic sky surveys such as LSST or Pan-STARRS. The effective field of view is obtained by 19 cameras arranged in a spherical mosaic form. These individual cameras of the device stand on a hexapod mount that is fully capable of achieving sidereal tracking for the subsequent exposures. This platform has many advantages. First of all it requires only one type of moving component and does not include unique parts. Hence this design not only eliminates problems implied by unique elements, but the redundancy of the hexapod allows smooth operations even if one or two of the legs are stuck. In addition, it can calibrate itself by observed stars independently from both the geographical location (including northen and southern hemisphere) and the polar alignment of the full mount. All mechanical elements and electronics are designed within the confines of our institute Konkoly Observatory. Currently, our instrument is in testing phase with an operating hexapod and reduced number of cameras.

  18. Eye structure and amphibious foraging in albatrosses

    Science.gov (United States)

    Martin, G. R.

    1998-01-01

    Anterior eye structure and retinal visual fields were determined in grey-headed and black-browed albatrosses, Diomedea melanophris and D. chrysostoma (Procellariiformes, Diomedeidae), using keratometry and an ophthalmoscopic reflex technique. Results for the two species were very similar and indicate that the eyes are of an amphibious optical design suggesting that albatross vision is well suited to the visual pursuit of active prey both on and below the ocean surface. The corneas are relatively flat (radius ca. 14.5 mm) and hence of low absolute refractive power (ca. 23 dioptres). In air the binocular fields are relatively long (vertical extent ca. 70 degrees) and narrow (maximum width in the plane of the optic axes 26–32 degrees), a topography found in a range of bird species that employ visual guidance of bill position when foraging. The cyclopean fields measure approximately 270 degrees in the horizontal plane, but there is a 60 degrees blind sector above the head owing to the positioning of the eyes below the protruding supraorbital ridges. Upon immersion the monocular fields decrease in width such that the binocular fields are abolished. Anterior eye structure, and visual field topography in both air and water, show marked similarity with those of the Humboldt penguin.

  19. New eye phantom for ophthalmic surgery

    Science.gov (United States)

    Fogli, Gessica; Orsi, Gianni; De Maria, Carmelo; Montemurro, Francesca; Palla, Michele; Rizzo, Stanislao; Vozzi, Giovanni

    2014-06-01

    In this work, we designed and realized a new phantom able to mimic the principal mechanical, rheological, and physical cues of the human eye and that can be used as a common benchmark to validate new surgical procedures, innovative vitrectomes, and as a training system for surgeons. This phantom, in particular its synthetic humor vitreous, had the aim of reproducing diffusion properties of the natural eye and can be used as a system to evaluate the pharmacokinetics of drugs and optimization of their dose, limiting animal experiments. The eye phantom was built layer-by-layer starting from the sclera up to the retina, using low cost and easy to process polymers. The validation of the phantom was carried out by mechanical characterization of each layer, by diffusion test with commercial drugs into a purposely developed apparatus, and finally by a team of ophthalmic surgeons. Experiments demonstrated that polycaprolactone, polydimethylsiloxane, and gelatin, properly prepared, are the best materials to mimic the mechanical properties of sclera, choroid, and retina, respectively. A polyvinyl alcohol-gelatin polymeric system is the best for mimicking the viscosity of the human humor vitreous, even if the bevacizumab half-life is lower than in the human eye.

  20. Understanding the Structure of the Eye

    Science.gov (United States)

    Research Experience for Teachers (RET) Program, Center of Advancement of Engineering Fibers and Films,

    Students learn about the anatomical structure of the human eye and how humans see light, as well as some causes of color blindness. They conduct experiments as an example of research to gather information. During their investigations, they test other students' vision, gathering data and measurements about when objects appear blurry. These topics help students prepare to design solutions to an overarching engineering challenge question.

  1. Microoptical telescope compound eye

    OpenAIRE

    Duparre, J.; Schreiber, P.; Matthes, A.; Pshenay-severin, E.; Tu?nnermann, A.; Vo?lkel, R.; Eisner, M.; Scharf, T.

    2005-01-01

    A new optical concept for compact digital image acquisition devices with large field of view is developed and proofed experimentally. Archetypes for the imaging system are compound eyes of small insects and the Gabor-Superlens. A paraxial 3x3 matrix formalism is used to describe the telescope arrangement of three microlens arrays with different pitch to find first order parameters of the imaging system. A 2mm thin imaging system with 21x3 channels, 70°x10° field of view and 4.5mm x 0.5mm im...

  2. [Formation, development and changes of the eye acupunture region-dividing acupoint location program].

    Science.gov (United States)

    Che, Jian; Tian, Wei-zhu

    2005-04-01

    Eye acupuncture, a micro-needling therapy, has been widely applied in clinical treatment for over 30 years. Its theoretic system, especially, the eye acupuncture region-dividing point location program has been revised for 2 times, and the third program with reasonability of acupoint distribution, strictness of angle of acupoint region is easily accepted by clinical workers. In the paper, the theoretical basis of professor Peng Jingshan's inspection of the eye for recognition of diseases, diagnosis of diseases and eye acupuncture therapy were explained, and the information, development and change of the eye acupuncture region-dividing acupoint location program were analyzed and the history of development of eye acupuncture were introduced so as to direct clinical application of eye acupuncture. PMID:16309109

  3. A free geometry model-independent neural eye-gaze tracking system

    Directory of Open Access Journals (Sweden)

    Gneo Massimo

    2012-11-01

    Full Text Available Abstract Background Eye Gaze Tracking Systems (EGTSs estimate the Point Of Gaze (POG of a user. In diagnostic applications EGTSs are used to study oculomotor characteristics and abnormalities, whereas in interactive applications EGTSs are proposed as input devices for human computer interfaces (HCI, e.g. to move a cursor on the screen when mouse control is not possible, such as in the case of assistive devices for people suffering from locked-in syndrome. If the user’s head remains still and the cornea rotates around its fixed centre, the pupil follows the eye in the images captured from one or more cameras, whereas the outer corneal reflection generated by an IR light source, i.e. glint, can be assumed as a fixed reference point. According to the so-called pupil centre corneal reflection method (PCCR, the POG can be thus estimated from the pupil-glint vector. Methods A new model-independent EGTS based on the PCCR is proposed. The mapping function based on artificial neural networks allows to avoid any specific model assumption and approximation either for the user’s eye physiology or for the system initial setup admitting a free geometry positioning for the user and the system components. The robustness of the proposed EGTS is proven by assessing its accuracy when tested on real data coming from: i different healthy users; ii different geometric settings of the camera and the light sources; iii different protocols based on the observation of points on a calibration grid and halfway points of a test grid. Results The achieved accuracy is approximately 0.49°, 0.41°, and 0.62° for respectively the horizontal, vertical and radial error of the POG. Conclusions The results prove the validity of the proposed approach as the proposed system performs better than EGTSs designed for HCI which, even if equipped with superior hardware, show accuracy values in the range 0.6°-1°.

  4. User Interface Considerations for Collecting Data at the Point of Care in the Tablet PC Computing Environment

    OpenAIRE

    Silvey, Garry M.; Lobach, David F.; Macri, Jennifer M.; Hunt, Megan; Kacmaz, Roje O.; Lee, Paul P.

    2006-01-01

    Collecting clinical data directly from clinicians is a challenge. Many standard development environments designed to expedite the creation of user interfaces for electronic healthcare applications do not provide acceptable components for satisfying the requirements for collecting and displaying clinical data at the point of care on the tablet computer. Through an iterative design and testing approach using think-aloud sessions in the eye care setting, we were able to identify and resolve seve...

  5. Assessing and managing eye injuries

    Directory of Open Access Journals (Sweden)

    Karin Lecuona

    2005-10-01

    Full Text Available njuries to the eye are common. Many are minor but, if not treated quickly and appropriately, can lead to sight-threatening complications. Other injuries are severe, and even with expert management sight can be lost. Prevention of blindness from eye injuries requires: * injury prevention (health promotion including advocacy * early presentation by the patient (health promotion and health worker training * accurate assessment (good primary eye care and first aid * prompt referral of serious injuries requiring specialist management.

  6. Principles of Drosophila Eye Differentiation

    OpenAIRE

    Cagan, Ross

    2009-01-01

    The Drosophila eye is one of nature's most beautiful structures and one of its most useful. It has emerged as a favored model for understanding the processes that direct cell fate specification, patterning, and morphogenesis. Though composed of thousands of cells, each fly eye is a simple repeating pattern of perhaps a dozen cell types arranged in a hexagonal array that optimizes coverage of the visual field. This simple structure combined with powerful genetic tools make the fly eye an ideal...

  7. Assessing and managing eye injuries

    OpenAIRE

    Karin Lecuona

    2005-01-01

    njuries to the eye are common. Many are minor but, if not treated quickly and appropriately, can lead to sight-threatening complications. Other injuries are severe, and even with expert management sight can be lost. Prevention of blindness from eye injuries requires: * injury prevention (health promotion including advocacy) * early presentation by the patient (health promotion and health worker training) * accurate assessment (good primary eye care and first aid) * prompt refe...

  8. Are 3-D Movies Bad for Your Eyes?

    Medline Plus

    Full Text Available ... Preventing Eye Injuries Smokers Sports Using Eye Makeup Veterans What Is an Ophthalmologist? Your Eyes & the Sun ... Sports and Eye Protection Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Water & ...

  9. Are 3-D Movies Bad for Your Eyes?

    Medline Plus

    Full Text Available ... Bad for Your Eyes? Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During Pregnancy Computer ... Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Water & Contacts Don’t Mix To ...

  10. Aging and dry eye disease.

    Science.gov (United States)

    Ding, Juan; Sullivan, David A

    2012-07-01

    Dry eye disease is a prevalent eye disorder that in particular affects the elderly population. One of the major causes of dry eye, meibomian gland dysfunction (MGD), shows increased prevalence with aging. MGD is caused by hyperkeratinization of the ductal epithelium of meibomian gland and reduced quantity and/or quality of meibum, the holocrine product that stabilizes and prevents the evaporation of the tear film. Of note, retinoids which are used in current anti-aging cosmetics may promote the development of MGD and dry eye disease. In this review, we will discuss the possible mechanisms of age-related MGD. PMID:22569356

  11. Characteristics of eye care practices with managed care contracts

    OpenAIRE

    Kapur, Kanika; Solomon, Matthew D.; Lee, Paul P.; Mangione, Carol M.; Adams, John L.; Wickstrom, Steven L.; Escarce, Jose? J.

    2002-01-01

    Objectives: To describe the variation in practice structure, financial arrangements, and utilization and quality management systems for eye care practices with managed care contracts. Study Design: Cross-sectional survey of 88 group and 56 solo eye care practices that contract with 6 health plans affiliated with a national managed care organization. The survey contained modules on practice structure, financial arrangements, utilization management, and quality management. The survey r...

  12. Ultraviolet radiation: the eye

    International Nuclear Information System (INIS)

    Under most conditions, the eye is well adapted to protect itself against ultraviolet radiation encountered in the outdoor environment as a result of the exposure geometry of the sun. Only when snow is on the ground does one experience acute effects of UV sunlight exposure (i.e. snow blindness, or photokeratitis). With regard to artificial sources, there are many occasions where one views bright light sources such as tungsten-halogen lamps, arc lamps and welding arcs. Such viewing is normally only momentary because of the aversion response to bright light and due to discomfort glare. However, such an aversion does not take place for germicidal lamps and other UV lamps which do not contain a strong visible component in their spectrum. The adverse effects from viewing such sources has been studied for decades and during the last two decades guidelines for limiting exposure to protect the eye have been developed. The guidelines were fostered to a large extent by the growing use of lasers and the quickly recognized hazard posed by viewing laser sources. (author)

  13. Eye in the Sky

    Science.gov (United States)

    National Geographic magazine, long known for its educational maps and writing that is easily understood by a variety of readers, has added a feature to its Website. The new online resource from National Geographic, sponsored by the National Imagery and Mapping Agency (NIMA), is called Eye in the Sky, and it showcases what we can learn about our planet using satellites. Here, users can read about the history of satellites and remote-sensing technology and choose from a menu of brief lessons on natural disasters, human impacts on Earth, human conflicts, and exploration of Mars. Each lesson page gives photographs, facts, and short movies (RealPlayer or Windows Media Player). The title "Eye in the Sky" is slightly misleading because most of the images featured are taken at ground-level, and it isn't always clear how some of the lessons fit with the idea of remote sensing. Nevertheless, the site is worth a look, and a few satellite images (of floodplains and the ozone hole, for example) pepper the material here.

  14. Eye in pregnancy

    Directory of Open Access Journals (Sweden)

    Achyut N. Pandey

    2014-02-01

    Full Text Available Hormonal, metabolic, hemodynamic, vascular and immunological changes that occur during pregnancy can affect the function of the eye. These changes are commonly transient, but in some cases they may be permanent and have consequences even after childbirth. The ocular effects of pregnancy may be physiological or pathological and can be associated with the development of new ocular pathology or may be modifications of pre-existing conditions. The most common physiological changes are alterations of corneal sensitivity and thickness, decreased tolerance to contact lenses, decreased intraocular pressure, hemeralopia and refractive errors. Possible posterior segment changes include worsening of diabetic retinopathy, central serous chorioretinopathy, increased risk of peripheral vitreochorioretinal dystrophies and retinal detachment. Thus, it should be kept in mind that the presence of any ocular symptoms in a pregnant woman requires ophthalmologic examination and further management. Knowledge of these ocular changes can help to differentiate the physiological changes from ocular manifestation of systemic disease and diseases pertaining to the eye in a pregnant woman. This article explains the effects of ocular changes in pregnancy. [Int J Res Med Sci 2014; 2(1.000: 16-20

  15. Double Eye Brow: A Rare Case Report

    OpenAIRE

    Kar, Sudipta; Ghosh, Chiranjit; Bazmi, Badruddin Ahamed; Sarkar, Subrata

    2013-01-01

    Eye brows are essential for esthetic and functional purposes. Various kinds of eye brows are found in human species. Protective function is one of the important functions of eye brows. Double eye brow is a very rare condition found in human. This case report describes one of the rare cases of double eye brow.

  16. Game Design and Homemade PowerPoint Games: An Examination of the Justifications and a Review of the Research

    Science.gov (United States)

    Siko, Jason; Barbour, Michael

    2013-01-01

    Research on educational games often focuses on the benefits that playing games has on student achievement. However, there is a growing body of research examining the benefits of having students design games rather than play them. Problems with game design as an instructional tool include the additional instruction on the programming language…

  17. Organizing design activities associated with Instrumentation and Control system upgrading at an operating WWER type nuclear power plant: General Designer's point of view

    International Nuclear Information System (INIS)

    Some problems that the company Energoprojekt as the General Designer encountered when setting up the basic design for replacement of the Instrumentation and Control (I and C) Systems in the nuclear power plants at Mochovce in Slovakia and Temelin in the Czech Republic are highlighted. The possibility of making use of the experience when organizing other design activities associated with I and C system replacement is discussed. Although the two NPPs are undergoing I and C system replacement prior to their commissioning, the company can benefit from the experience when organizing design activities for I and C system replacement at operating WWERs as well

  18. Fly eye radar or micro-radar sensor technology

    Science.gov (United States)

    Molchanov, Pavlo; Asmolova, Olga

    2014-05-01

    To compensate for its eye's inability to point its eye at a target, the fly's eye consists of multiple angularly spaced sensors giving the fly the wide-area visual coverage it needs to detect and avoid the threats around him. Based on a similar concept a revolutionary new micro-radar sensor technology is proposed for detecting and tracking ground and/or airborne low profile low altitude targets in harsh urban environments. Distributed along a border or around a protected object (military facility and buildings, camp, stadium) small size, low power unattended radar sensors can be used for target detection and tracking, threat warning, pre-shot sniper protection and provides effective support for homeland security. In addition it can provide 3D recognition and targets classification due to its use of five orders more pulses than any scanning radar to each space point, by using few points of view, diversity signals and intelligent processing. The application of an array of directional antennas eliminates the need for a mechanical scanning antenna or phase processor. It radically decreases radar size and increases bearing accuracy several folds. The proposed micro-radar sensors can be easy connected to one or several operators by point-to-point invisible protected communication. The directional antennas have higher gain, can be multi-frequency and connected to a multi-functional network. Fly eye micro-radars are inexpensive, can be expendable and will reduce cost of defense.

  19. The software design of multi-branch, multi-point remote monitoring system for temperature measurement based on MSP430 and DS18B20

    International Nuclear Information System (INIS)

    This paper present that the system can acquire the remote temperature measurement data of 40 monitoring points, through the RS-232 serial port and the Intranet. System's hardware is consist of TI's MSP430F149 mixed-signal processor and UA7000A network module. Using digital temperature sensor DS18B20, the structure is simple and easy to expand, the sensors directly send out the temperature data, MSP430F149 has the advantage of ultra-low-power and high degree of integration. Using msp430F149, the multi-branch multi-point temperature measurement system is powerful, simple structure, high reliability, strong anti-interference capability. The client software is user-friendly and easy to use, it is designed in Microsoft Visual C+ +6.0 environment. The monitoring system is able to complete a total of 4 branches of the 40-point temperature measurements in real-time remote monitoring. (authors)

  20. Eye tracking and gating system for proton therapy of orbital tumors

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Dongho; Yoo, Seung Hoon; Moon, Sung Ho; Yoon, Myonggeun; Lee, Se Byeong; Park, Sung Yong [Proton Therapy Center, National Cancer Center, Goyang, Gyeonggi 410-769 (Korea, Republic of); Department of Radiation Oncology, CHA Bundang Medical Center, CHA University, Seongnam, Gyeonggi 463-712 (Korea, Republic of); Proton Therapy Center, National Cancer Center, Goyang, Gyeonggi 410-769 (Korea, Republic of); Department of Radiological Science, Korea University, Seoul 136-703 (Korea, Republic of); Proton Therapy Center, National Cancer Center, Goyang, Gyeonggi 410-769 (Korea, Republic of); Proton Therapy Center, McLaren Cancer Institute, Flint, Michigan 48532 (United States)

    2012-07-15

    Purpose: A new motion-based gated proton therapy for the treatment of orbital tumors using real-time eye-tracking system was designed and evaluated. Methods: We developed our system by image-pattern matching, using a normalized cross-correlation technique with LabVIEW 8.6 and Vision Assistant 8.6 (National Instruments, Austin, TX). To measure the pixel spacing of an image consistently, four different calibration modes such as the point-detection, the edge-detection, the line-measurement, and the manual measurement mode were suggested and used. After these methods were applied to proton therapy, gating was performed, and radiation dose distributions were evaluated. Results: Moving phantom verification measurements resulted in errors of less than 0.1 mm for given ranges of translation. Dosimetric evaluation of the beam-gating system versus nongated treatment delivery with a moving phantom shows that while there was only 0.83 mm growth in lateral penumbra for gated radiotherapy, there was 4.95 mm growth in lateral penumbra in case of nongated exposure. The analysis from clinical results suggests that the average of eye movements depends distinctively on each patient by showing 0.44 mm, 0.45 mm, and 0.86 mm for three patients, respectively. Conclusions: The developed automatic eye-tracking based beam-gating system enabled us to perform high-precision proton radiotherapy of orbital tumors.

  1. Eye tracking and gating system for proton therapy of orbital tumors

    International Nuclear Information System (INIS)

    Purpose: A new motion-based gated proton therapy for the treatment of orbital tumors using real-time eye-tracking system was designed and evaluated. Methods: We developed our system by image-pattern matching, using a normalized cross-correlation technique with LabVIEW 8.6 and Vision Assistant 8.6 (National Instruments, Austin, TX). To measure the pixel spacing of an image consistently, four different calibration modes such as the point-detection, the edge-detection, the line-measurement, and the manual measurement mode were suggested and used. After these methods were applied to proton therapy, gating was performed, and radiation dose distributions were evaluated. Results: Moving phantom verification measurements resulted in errors of less than 0.1 mm for given ranges of translation. Dosimetric evaluation of the beam-gating system versus nongated treatment delivery with a moving phantom shows that while there was only 0.83 mm growth in lateral penumbra for gated radiotherapy, there was 4.95 mm growth in lateral penumbra in case of nongated exposure. The analysis from clinical results suggests that the average of eye movements depends distinctively on each patient by showing 0.44 mm, 0.45 mm, and 0.86 mm for three patients, respectively. Conclusions: The developed automatic eye-tracking based beam-gating system enabled us to perform high-precision proton radiotherapy of orbital tumors.

  2. Conjunctivitis: What Is Pink Eye?

    Science.gov (United States)

    ... Screening Guidelines Home Remedies for Simple Eye Problems Medical Marijuana for Glaucoma Pregnancy Preventing Eye Injuries Smokers Sports ... Policy Email address ... text or images from this website is strictly prohibited by US and international copyright law. You may link from your website to any ...

  3. If I Had - Dry Eyes

    Medline Plus

    Full Text Available ... as editor in chief of the Mount Sinai Journal of Medicine. At the American Academy of Ophthalmology ... if we treat that we can help the patient. Who is at risk of developing dry eye? Dr. Asbell: Dry eye is a very common problem. ... A Custom Feed © 2013, CEH Inc. All ...

  4. The Eye of the Hurricane

    Science.gov (United States)

    This lesson plan introduces students to the structure of a hurricane, particularly the eye. It can be used as an introduction to a unit on hurricanes or weather phenomena. Students will view a video about hurricanes, do a simple hurricane simulation, take a tour into the eye of a hurricane, and write reports about their tour.

  5. Design and fabrication of a miniaturization micro volume auto titrator coupled with electrochemical end-point detector for the determination of acidity of some fruit juice

    OpenAIRE

    Prinya Masawat

    2008-01-01

    A miniaturization micro volume auto titrator coupled with electrochemical end-point detector was designed and fabricated for the determination of acidity of some Thai citrus fruit juices collected in the northern area of Thailand. The method was based on on-line potentiometric titration of the acid contents with sodium hydroxide. Conditions such as volume of fruit juice sample, volume and concentration of potassium chloride used as supporting electrolyte and flow rate of titrant were optimize...

  6. Eyelashes divert airflow to protect the eye.

    Science.gov (United States)

    Amador, Guillermo J; Mao, Wenbin; DeMercurio, Peter; Montero, Carmen; Clewis, Joel; Alexeev, Alexander; Hu, David L

    2015-04-01

    Eyelashes are ubiquitous, although their function has long remained a mystery. In this study, we elucidate the aerodynamic benefits of eyelashes. Through anatomical measurements, we find that 22 species of mammals possess eyelashes of a length one-third the eye width. Wind tunnel experiments confirm that this optimal eyelash length reduces both deposition of airborne particles and evaporation of the tear film by a factor of two. Using scaling theory, we find this optimum arises because of the incoming flow's interactions with both the eye and eyelashes. Short eyelashes create a stagnation zone above the ocular surface that thickens the boundary layer, causing shear stress to decrease with increasing eyelash length. Long eyelashes channel flow towards the ocular surface, causing shear stress to increase with increasing eyelash length. These competing effects result in a minimum shear stress for intermediate eyelash lengths. This design may be employed in creating eyelash-inspired protection for optical sensors. PMID:25716186

  7. Hemangiomas and the eye.

    Science.gov (United States)

    Spence-Shishido, Allyson A; Good, William V; Baselga, Eulalia; Frieden, Ilona J

    2015-01-01

    Infantile hemangiomas are a common vascular birthmark with heterogeneous presentations and unique growth characteristics with early rapid growth and eventual self-involution. Hemangiomas that develop around the eye have the potential for inducing amblyopia by several mechanisms and may eventually result in permanent visual impairment in otherwise healthy infants. Segmental periocular hemangiomas carry the additional risk of associated structural anomalies and PHACE syndrome. In recent years, the treatment of periocular hemangiomas has been revolutionized by the serendipitous discovery of the effectiveness of beta-blockers (systemic and topical), with most experts viewing these as first-line therapies. The management of periocular hemangiomas should involve a close partnership between an ophthalmologist and dermatologist or other relevant specialists familiar with the unique clinical features, differential diagnosis, treatment approaches, and potential complications. PMID:25704937

  8. Eye of Science

    Science.gov (United States)

    The wonderful Eye of Science project began in 1994, and is currently under the direction of Oliver Meckes and Nicole Ottawa. As their philosophic statement on this website states, "Our aim is to combine scientific exactness with aesthetic appearances, and thereby help to bridge the gap between the world of science and the world of art." In order to help serve this mission, they have placed numerous examples of their work online in a series of galleries on this site. Using electron microscopy and a host of other equipment and techniques, the pair has created these fine images of such things as parasites, cross-sections of a lavender leaf, and a rather harrowing photograph of an itch mite. Along with viewing these images, visitors can also learn about the awards they have received and learn about the equipment they use in their work.

  9. Eye movements in Alzheimer's disease.

    Science.gov (United States)

    Molitor, Robert J; Ko, Philip C; Ally, Brandon A

    2015-01-01

    A growing body of literature has investigated changes in eye movements as a result of Alzheimer's disease (AD). When compared to healthy, age-matched controls, patients display a number of remarkable alterations to oculomotor function and viewing behavior. In this article, we review AD-related changes to fundamental eye movements, such as saccades and smooth pursuit motion, in addition to changes to eye movement patterns during more complex tasks like visual search and scene exploration. We discuss the cognitive mechanisms that underlie these changes and consider the clinical significance of eye movement behavior, with a focus on eye movements in mild cognitive impairment. We conclude with directions for future research. PMID:25182738

  10. Modular DIPS, 2.5-kWe modules for lunar/Mars surface applications, design point selection summary

    International Nuclear Information System (INIS)

    This paper reports that the Dynamic Isotope Power System (DIPS) Demonstration Program is currently focused on the development of a standardized 2.5-kWe portable generator for multiple applications on the lunar or Martian surface. An optimum system configuration has been developed for the 2.5-kWe DIPS module that provides a system with a radiator area which is small and manageable without significantly impacting the system mass, efficiency, and technological risk. The 2.5-kWe DIPS module configuration was developed based on a systematic series of studies. Initially, technology breakpoints in the DIPS component and subsystem designs were identified. Based on the technology assessments, the maximum design temperature for the system was selected and various system and subsystem configurations were evaluated. Finally, the subsystem and system designs for the selected configuration were optimized using a detailed system design optimization computer code

  11. 21 CFR 886.3200 - Artificial eye.

    Science.gov (United States)

    2010-04-01

    ...2010-04-01 2010-04-01 false Artificial eye. 886.3200 Section 886.3200 Food and...Prosthetic Devices § 886.3200 Artificial eye. (a) Identification. An artificial eye is a device resembling the anterior portion...

  12. Lateral Eye Movement and Cogitation in Junior High School Students.

    Science.gov (United States)

    Lauria, Mark W.; Wichman, Harvey

    In a between-subject experimental design, 31 randomly selected junior high school students demonstrated lateral eye movement (LEM) immediately following the administration of each question in a group of questions, designed to alternately activate either the left or the right cerebral hemisphere. Because the subjects showed consistency in their…

  13. Can the Hazard Assessment and Critical Control Points (HACCP) system be used to design process-based hygiene concepts?

    OpenAIRE

    Hu?bner, No; Fleßa, S.; Haak, J.; Wilke, F.; Hu?bner, C.; Dahms, C.; Hoffmann, W.; Kramer, A.

    2011-01-01

    Recently, the HACCP (Hazard Analysis and Critical Control Points) concept was proposed as possible way to implement process-based hygiene concepts in clinical practice, but the extent to which this food safety concept can be transferred into the health care setting is unclear. We therefore discuss possible ways for a translation of the principles of the HACCP for health care settings. While a direct implementation of food processing concepts into health care is not very likely to be feasible ...

  14. Case study: improving the management of eye care programmes

    Directory of Open Access Journals (Sweden)

    Kolawole Olumide Ogundimu

    2008-12-01

    Full Text Available Nigeria is a federation of 36 administrative States, which each have a mandate to deliver health care to their population. Sightsavers International has been supporting four State ministries of health (Cross River, Kaduna, Kwara, and Sokoto in implementing programmes designed to provide comprehensive eye care services.Previously, eye care had been limited to services in big hospitals in the largest cities, which were inaccessible to the general population.These new eye care programmes have been very successful. The Kwara eye care programme (KWECP, for example, has increased the cataract surgical rate from 196 cataract operations per million per year in 2003 to 932 in 2007.This article describes what we have learnt from our experience in managing these programmes and hopefully will provide you with suggestions to improve management.

  15. Metodología para incrementar el número de puntos experimentales en un diseño D-Óptimo / Methods for Increasing the Number of Experimental Points on a D-Optimal Design

    Scientific Electronic Library Online (English)

    Sindi, Argumedo Galván; Víctor Ignacio, López-Ríos.

    2014-07-30

    Full Text Available La finalidad de los diseños óptimos es determinar las condiciones experimentales adecuadas de tal forma que se pueda garantizar inferencias estadísticas lo más precisas posibles en términos de mínima varianza del vector de parámetros estimado. Esta teoría presupone el conocimiento de la función que [...] relaciona las variables explicativas con la variable respuesta, en esta situación, con frecuencia, se obtienen diseños con tantos puntos de soporte como parámetros tiene el modelo propuesto en la investigación. Dado que los diseños con p-puntos de soporte asumen que la función del modelo es conocida, éstos pueden llegar a ser no tan óptimos en algunas situaciones prácticas, debido a que no permiten probar la bondad de ajuste del modelo asumido [1]. En este artículo se presenta una generalización de la metodología propuesta en [2] para aumentar el número de puntos en el criterio D-optimalidad. Se encuentra una expresión para la varianza de la respuesta predicha en términos de una constante de ponderación ?, la cual permitirá determinar los puntos a adicionar al diseño D-óptimo. Se propone una estrategia para la elección de la constante ?. Finalmente se proporciona un diseño seudo-óptimo con p+s puntos de experimentación. Abstract in english The purpose of the optimum designs is to determine the optimal experimental conditions in terms of minimum variance of the estimated vector of parameters, so that statistical inferences can be generated as accurate as possible. This theory presupposes knowledge of the function relating the explanato [...] ry variables with the response variable. In this situation, usually get designs with support points as parameters in the model. Since p-point designs assume that the model function is known, these could not be optimal in some practical situations because they do not allow to test the goodness of fit of the assumed model [1]. In this paper we present a generalization of the methodology proposed by [2] to increase the number of support points in D-optimality criterion. An expression for the variance of the predicted response in terms of a constant ? will be provided, which allow to determine the points to be added to the D-optimal design. We propose a strategy for choosing ?. Finally we provide a pseudo-optimal design with (p + s) support points.

  16. Design and Realization of Integrated Management System for Data Interoperability between Point-of-Care Testing Equipment and Hospital Information System

    Science.gov (United States)

    Park, Ki Sang; Heo, Hyuk

    2013-01-01

    Objectives The purpose of this study was to design an integrated data management system based on the POCT1-A2, LIS2-A, LIS2-A2, and HL7 standard to ensure data interoperability between mobile equipment, such as point-of-care testing equipment and the existing hospital data system, its efficiency was also evaluated. Methods The method of this study was intended to design and realize a data management system which would provide a solution for the problems that occur when point-of-care testing equipment is introduced to existing hospital data, after classifying such problems into connectivity, integration, and interoperability. This study also checked if the data management system plays a sufficient role as a bridge between the point-of-care testing equipment and the hospital information system through connection persistence and reliability testing, as well as data integration and interoperability testing. Results In comparison with the existing system, the data management system facilitated integration by improving the result receiving time, improving the collection rate, and by enabling the integration of disparate types of data into a single system. And it was found out that we can solve the problems related to connectivity, integration and interoperability through generating the message in standardized types. Conclusions It is expected that the proposed data management system, which is designed to improve the integration point-of-care testing equipment with existing systems, will establish a solid foundation on which better medical service may be provided by hospitals by improving the quality of patient service. PMID:24175121

  17. Eyes on the LHC

    CERN Multimedia

    Gianotti, Fabiola

    2007-01-01

    "Particle physicists don't know for sure what explorations at the Large Hadron Collider will bring. But they do know that many mysteries in their field point toward solutions at the LHC's impressive TeV energy scale."

  18. Radiation injuries of the eye and prophylactic measures

    International Nuclear Information System (INIS)

    Radiation injuries of the eye, particularly the cataract, caused by different kinds of radiation such as ionizing radiations, laser beams, infrared radiation, and microwaves as well as the mechanisms of their origin are pointed out and connected problems of radiation protection are discussed

  19. Methodology and concepts for the design of surface storage fills at the Anvil Points Oil Shale Retort Facility

    Energy Technology Data Exchange (ETDEWEB)

    Strohm, W.E. Jr.; Krinitzsky, E.L.

    1983-12-01

    Primary obtectives in design of surface disposal fills for processed and raw oil shales are: (a) to insure long-term physical stability, and (b) to prevent surface runoff, surface erosion, and possible subsurface seepage from degrading the water quality of streams and ground water, it was concluded that the analysis and design of spent shale disposal fills should be based on sound geotechnical engineeering principles, considerable experience, and good judgment. An understanding of the source of variability of spent shale materials and its effect on engineering properties is a first step in developing fill design. A second important step is the assessment of long-term changes in the properties of spent shale within a disposal fill. This assessment requires consideration of possible thermal, hydrochemical, and physical interactions within the fill and between the fill and site environment. The site environment is site-specific and depends on the geological, surface and subsurface hydrological, and geotechnical characteristics of the site. The variability of spent shale materials is a direct function of variations in mineral and chemical composition of the raw shale and of the processes applied. Current technology for the design and construction of spent shale disposal fills has not been proven by experience. A major problem is the large quantities of spent shale generated for surface disposal and the lack of available sites other than large gulches in the oil shale country of the western United States. Conceptual research fill designs developed in this study should be refined and constructed to provide needed information on in situ properties and long-term performance. Research fills planned by others should be augmented to obtain needed information, especially for codisposal of spent shales with treated waste water, raw shale fines, and process dust.

  20. Eye-safe lidar system for pesticide spray drift measurement.

    Science.gov (United States)

    Gregorio, Eduard; Rocadenbosch, Francesc; Sanz, Ricardo; Rosell-Polo, Joan R

    2015-01-01

    Spray drift is one of the main sources of pesticide contamination. For this reason, an accurate understanding of this phenomenon is necessary in order to limit its effects. Nowadays, spray drift is usually studied by using in situ collectors which only allow time-integrated sampling of specific points of the pesticide clouds. Previous research has demonstrated that the light detection and ranging (lidar) technique can be an alternative for spray drift monitoring. This technique enables remote measurement of pesticide clouds with high temporal and distance resolution. Despite these advantages, the fact that no lidar instrument suitable for such an application is presently available has appreciably limited its practical use. This work presents the first eye-safe lidar system specifically designed for the monitoring of pesticide clouds. Parameter design of this system is carried out via signal-to-noise ratio simulations. The instrument is based on a 3-mJ pulse-energy erbium-doped glass laser, an 80-mm diameter telescope, an APD optoelectronic receiver and optomechanically adjustable components. In first test measurements, the lidar system has been able to measure a topographic target located over 2 km away. The instrument has also been used in spray drift studies, demonstrating its capability to monitor the temporal and distance evolution of several pesticide clouds emitted by air-assisted sprayers at distances between 50 and 100 m. PMID:25658395

  1. Eye-Safe Lidar System for Pesticide Spray Drift Measurement

    Directory of Open Access Journals (Sweden)

    Eduard Gregorio

    2015-02-01

    Full Text Available Spray drift is one of the main sources of pesticide contamination. For this reason, an accurate understanding of this phenomenon is necessary in order to limit its effects. Nowadays, spray drift is usually studied by using in situ collectors which only allow time-integrated sampling of specific points of the pesticide clouds. Previous research has demonstrated that the light detection and ranging (lidar technique can be an alternative for spray drift monitoring. This technique enables remote measurement of pesticide clouds with high temporal and distance resolution. Despite these advantages, the fact that no lidar instrument suitable for such an application is presently available has appreciably limited its practical use. This work presents the first eye-safe lidar system specifically designed for the monitoring of pesticide clouds. Parameter design of this system is carried out via signal-to-noise ratio simulations. The instrument is based on a 3-mJ pulse-energy erbium-doped glass laser, an 80-mm diameter telescope, an APD optoelectronic receiver and optomechanically adjustable components. In first test measurements, the lidar system has been able to measure a topographic target located over 2 km away. The instrument has also been used in spray drift studies, demonstrating its capability to monitor the temporal and distance evolution of several pesticide clouds emitted by air-assisted sprayers at distances between 50 and 100 m.

  2. B-EYE: The World Through the Eyes of a Honey Bee

    Science.gov (United States)

    Giger, Andrew.

    1995-01-01

    One of the great treats awaiting Scouts (or any others who learn to search the Web efficiently) is the large number of high quality science Websites put forth by Australian research institutions. B-EYE is yet another such wonderful site. Dr. Andrew Giger, a neuroscientist studying insect vision at the Centre for Visual Science (CVS) at Australian National University, put together this site so visitors could see the world "through the eyes of a honey bee." Although simplified to grayscale images (bees view colors differently than humans), the visual distortions (from human to bee) are fascinating and highly educational. The well-designed site takes the viewer through the specific elements of each visual distortion, offering descriptions, a gallery of pre-processed images, and several options for viewing. The most sophisticated option allows users to set parameters (distance to pattern, horizontal and vertical position, background intensity, etc.) to view a series of images through a human eye, a simulated projection, and eventually, a bee's eye.

  3. What the Eyes Already "Know": Using Eye Movement Measurement to Tap into Children's Implicit Numerical Magnitude Representations

    Science.gov (United States)

    Heine, Angela; Thaler, Verena; Tamm, Sascha; Hawelka, Stefan; Schneider, Michael; Torbeyns, Joke; De Smedt, Bert; Verschaffel, Lieven; Stern, Elsbeth; Jacobs, Arthur M.

    2010-01-01

    To date, a number of studies have demonstrated the existence of mismatches between children's "implicit" and "explicit" knowledge at certain points in development that become manifest by their gestures and gaze orientation in different problem solving contexts. Stimulated by this research, we used eye movement measurement to investigate the…

  4. Gender inequality in vision loss and eye diseases: Evidence from the Sultanate of Oman

    OpenAIRE

    Khandekar Rajiv; Mohammed A

    2009-01-01

    Purpose : The data from surveys of vision loss and monitoring of services were used to assess changes in gender inequality in Oman. Study Design : Retrospective review of data collection instruments. Materials and Method : The data sets of 12 years between 1996 and 2007 were abstracted to assess the gender equality for vision loss, eye disease prevalence, and service use. They included two surveys (1996 and 2005), Health Information from eye units (1998 and 2007), and eye screening i...

  5. The interblink interval in normal and dry eye subjects

    Directory of Open Access Journals (Sweden)

    Johnston PR

    2013-02-01

    Full Text Available Patrick R Johnston,1 John Rodriguez,1 Keith J Lane,1 George Ousler,1 Mark B Abelson1,21Ora, Inc, Andover, MA, USA; 2Schepens Eye Research Institute and Harvard Medical School, Boston, MA, USAPurpose: Our aim was to extend the concept of blink patterns from average interblink interval (IBI to other aspects of the distribution of IBI. We hypothesized that this more comprehensive approach would better discriminate between normal and dry eye subjects.Methods: Blinks were captured over 10 minutes for ten normal and ten dry eye subjects while viewing a standardized televised documentary. Fifty-five blinks were analyzed for each of the 20 subjects. Means, standard deviations, and autocorrelation coefficients were calculated utilizing a single random effects model fit to all data points and a diagnostic model was subsequently fit to predict probability of a subject having dry eye based on these parameters.Results: Mean IBI was 5.97 seconds for normal versus 2.56 seconds for dry eye subjects (ratio: 2.33, P = 0.004. IBI variability was 1.56 times higher in normal subjects (P < 0.001, and the autocorrelation was 1.79 times higher in normal subjects (P = 0.044. With regard to the diagnostic power of these measures, mean IBI was the best dry eye versus normal classifier using receiver operating characteristics (0.85 area under curve (AUC, followed by the standard deviation (0.75 AUC, and lastly, the autocorrelation (0.63 AUC. All three predictors combined had an AUC of 0.89. Based on this analysis, cutoffs of ?3.05 seconds for median IBI, and ?0.73 for the coefficient of variation were chosen to classify dry eye subjects.Conclusion: (1 IBI was significantly shorter for dry eye patients performing a visual task compared to normals; (2 there was a greater variability of interblink intervals in normal subjects; and (3 these parameters were useful as diagnostic predictors of dry eye disease. The results of this pilot study merit investigation of IBI parameters on a larger scale study in subjects with dry eye and other ocular surface disorders.Keywords: dry eye, interblink intervals, visual function, visual tasks, diagnostic model

  6. Eye hazards of environmental lighting

    International Nuclear Information System (INIS)

    In the 1950s and 1960s it became clear that the nuclear fireball and lasers could cause thermal retinal injury; at that time, the reference of Verhoeff, Bell, and Walker was often cited to argue that solar eclipse blindness (solar retinitis) was also a thermal retinal injury. It was not until 1975 that it became clear that a photochemical mechanism for retinal injury was possible for lengthy exposures in the primate or human eye. The potential for photochemical injury of the retina suggests the possibilities of delayed effects, and a considerable research effort has been underway over the last decade to study the implications for retinal degradation by intense light. The lens can undergo changes leading to cataract following exposure to ultraviolet radiation (UVR). Although acute UVR injury of the cornea (photokeratitis) has been recognized since the early part of this century, the link between UVR and cataract has long been a point of controversy. Today, most scientists studying optical radiation hazards conclude that UVR is a causative factor in some forms of cataract. Differences of opinion arise as to the exact wavelength range that is effective (i.e., UVA: 315-400 nm and/or UVB: 280-315 nm). Pitts and colleagues have shown that only a very narrow band of UVR wavelengths between 295 and 320 nm appear to be effective in causing acute cataract in experimental animals. Epidemiological studies of cataract incidence appear to show that UVR is a causative factor, despithow that UVR is a causative factor, despite the fact that at least one investigator had concluded that high ambient temperature was a more likely causative factor than UVR. This author has recently completed a study of UVR exposures in the outdoor environment that would support the epidemiologic studies of UVR induction of cataract

  7. Can the Hazard Assessment and Critical Control Points (HACCP system be used to design process-based hygiene concepts?

    Directory of Open Access Journals (Sweden)

    Hübner, N.-O.

    2011-01-01

    Full Text Available Recently, the HACCP (Hazard Analysis and Critical Control Points concept was proposed as possible way to implement process-based hygiene concepts in clinical practice, but the extent to which this food safety concept can be transferred into the health care setting is unclear. We therefore discuss possible ways for a translation of the principles of the HACCP for health care settings. While a direct implementation of food processing concepts into health care is not very likely to be feasible and will probably not readily yield the intended results, the underlying principles of process-orientation, in-process safety control and hazard analysis based counter measures are transferable to clinical settings. In model projects the proposed concepts should be implemented, monitored, and evaluated under real world conditions.

  8. A rigorous analysis using optimal transport theory for a two-reflector design problem with a point source

    International Nuclear Information System (INIS)

    We consider the following geometric optics problem: construct a system of two reflectors which transforms a spherical wavefront generated by a point source into a beam of parallel rays. This beam has a prescribed intensity distribution. We give a rigorous analysis of this problem. The reflectors we construct are (parts of) the boundaries of convex sets. We prove existence of solutions for a large class of input data and give a uniqueness result. To the author's knowledge, this is the first time that a rigorous mathematical analysis of this problem is given. The approach is based on optimal transportation theory. It yields a practical algorithm for finding the reflectors. Namely, the problem is equivalent to a constrained linear optimization problem

  9. Conjunctivitis (Pink Eye) in Newborns

    Science.gov (United States)

    ... Polio Enterovirus Parent Portal Conjunctivitis (Pink Eye) in Newborns Recommend on Facebook Tweet Share Compartir On this ... bacteria and by viruses. Causes of Conjunctivitis in Newborns The cause of neonatal conjunctivitis is difficult to ...

  10. If I Had - Dry Eyes

    Medline Plus

    Full Text Available ... Insidermedicine In 60 In Depth In the Spotlight If I Had... Universities and Hospitals By Disease or ... Seen in Older Adults with Severe COPD VIDEO: If I Had - Dry Eyes - Dr. Penny Asbell, MD, ...

  11. Roundworm Parasite Targets Canine Eyes

    Science.gov (United States)

    ... this page, please enable JavaScript. Roundworm Parasite Targets Canine Eyes Report says small number of cases reported ... 16, 2015 (HealthDay News) -- A small number of dogs and cats across the United States have been ...

  12. Eye-based head gestures

    DEFF Research Database (Denmark)

    Mardanbegi, Diako; Witzner Hansen, Dan

    2012-01-01

    A novel method for video-based head gesture recognition using eye information by an eye tracker has been proposed. The method uses a combination of gaze and eye movement to infer head gestures. Compared to other gesture-based methods a major advantage of the method is that the user keeps the gaze on the interaction object while interacting. This method has been implemented on a head-mounted eye tracker for detecting a set of predefined head gestures. The accuracy of the gesture classifier is evaluated and verified for gaze-based interaction in applications intended for both large public displays and small mobile phone screens. The user study shows that the method detects a set of defined gestures reliably.

  13. If I Had - Dry Eyes

    Medline Plus

    Full Text Available ... In 60 In Depth In the Spotlight If I Had... Universities and Hospitals By Disease or Symptom ... in Older Adults with Severe COPD VIDEO: If I Had - Dry Eyes - Dr. Penny Asbell, MD, FACS, ...

  14. Are 3-D Movies Bad for Your Eyes?

    Medline Plus

    Full Text Available ... Children & Teenagers Computer Usage Diabetes Diet & Nutrition Eye Injuries Eye Screening Guidelines Home Remedies for Simple Eye Problems Medical Marijuana for Glaucoma Pregnancy Preventing Eye Injuries Smokers Sports Using Eye Makeup Veterans What Is ...

  15. Are 3-D Movies Bad for Your Eyes?

    Medline Plus

    Full Text Available ... to 60 Adults Over 60 Babies, Children & Teenagers Computer Usage Diabetes Diet & Nutrition Eye Injuries Eye Screening ... Topics Preventing Eye Injuries Healthy Eyes During Pregnancy Computer Usage & Eye Strain Maintaining Your Sight with Diabetes ...

  16. Are 3-D Movies Bad for Your Eyes?

    Medline Plus

    Full Text Available ... D Movies Bad for Your Eyes? Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During ... video games will damage the eyes or visual system. Some people complain of headaches or motion sickness ...

  17. Are 3-D Movies Bad for Your Eyes?

    Medline Plus

    Full Text Available ... Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Water & Contacts Don’t Mix To help prevent eye ... right eye care provider for your condition or treatment. Are You Fit at 40? A baseline eye ...

  18. Are 3-D Movies Bad for Your Eyes?

    Medline Plus

    Full Text Available ... Alerts Are 3-D Movies Bad for Your Eyes? Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes ... over the battery and always wear safety goggles. Eye Protection Works Wearing the proper protective eyewear for ...

  19. Fluorophotometry as a diagnostic tool for the evaluation of dry eye disease

    Directory of Open Access Journals (Sweden)

    Fan Vincent C

    2006-05-01

    Full Text Available Abstract Background Dry eye disease is a common debilitating ocular disease. Current diagnostic tests used in dry eye disease are often neither sensitive nor reproducible, making it difficult to accurately diagnose and determine end points for clinical trials, or evaluate the usefulness of different medications in the treatment of dry eye disease. The recently developed fluorophotometer can objectively detect changes in the corneal epithelium by quantitatively measuring its barrier function or permeability. The purpose of the study is to investigate the use of corneal fluorescein penetration measured by the fluorophotometer as a diagnostic tool in the evaluation of dry eye patients. Methods Dry eye patients (16 eyes, who presented with a chief complaint of ocular irritation corresponding with dry eye, low Schirmer's one test ( Results Ten minutes after fluorescein installition, patients with dry eye disease averaged a five-fold increase in corneal tissue fluorescein concentration (mean = 375.26 ± 202.67 ng/ml compared with that of normal subjects (mean = 128.19 ± 85.84 ng/ml. Sixty minutes after dye installation, patients with dry eye disease still revealed higher corneal tissue fluorescein concentration (mean = 112.87 ± 52.83 ng/ml compared with that of controls (mean = 40.64 ± 7.96 ng/ml, averaging a three-fold increase. Conclusion Patients with dry eye disease demonstrated an increased corneal permeability and a slower rate of elimination to topically administered fluorescein when measured by the fluorophotometer. This suggests that fluorophotometry may serve as a valuable quantitative and objective tool for the diagnosis of dry eye disease, and in following patients' response to new treatment modalities. Fluorophotometry may serve as an objective non-invasive tool for end-point analysis in clinical trials of new treatments for dry eye disease.

  20. Increased drift in amblyopic eyes.

    OpenAIRE

    Ciuffreda, K. J.; Kenyon, R. V.; Stark, L.

    1980-01-01

    Reports are conflicting on the presence of increased drift in amblyopic eyes. Furthermore, the individual effects of either amblyopia or strabismus alone on ocular drift have not been systematically investigated. We therefore used a photoelectric method to record horizontal eye position during monocular and binocular fixation in patients having amblyopia without strabismus, intermittent strabismus, or constant strabismus amblyopia. Our principal finding was increased drift amplitude (up to 3....

  1. Compensatory eye movements in mice

    OpenAIRE

    Alphen, A. M.

    2002-01-01

    This thesis will address the generation of compensatory eye movements in naturally mutated or genetically modified mice. The reason for generating compensatory eye movements is solely related to the requirements for good vision. In a subject moving through its environment the projection of visual surround would slip across the retina and retinal slip of more than only a few degrees per second would cause blurring of the projected image and reduce visual acuity (Westheimer and M...

  2. Health claims database study of cyclosporine ophthalmic emulsion treatment patterns in dry eye patients

    Directory of Open Access Journals (Sweden)

    Stonecipher KG

    2013-10-01

    Full Text Available Karl G Stonecipher,1 Jenny Chia,2 Ahunna Onyenwenyi,2 Linda Villanueva,2 David A Hollander2 1TLC Laser Eye Centers, Greensboro, NC, 2Allergan, Inc., Irvine, CA, USA Background: Dry eye is a multifactorial, symptomatic disease associated with ocular surface inflammation and tear film hyperosmolarity. This study was designed to assess patterns of topical cyclosporine ophthalmic emulsion 0.05% (Restasis® use in dry eye patients and determine if there were any differences in use based on whether dry eye is physician-coded as a primary or nonprimary diagnosis. Methods: Records for adult patients with a diagnosis of dry eye at an outpatient visit from January 1, 2008 to December 31, 2009 were selected from Truven Health MarketScan® Research Databases. The primary endpoint was percentage of patients with at least one primary versus no primary dry eye diagnosis who filled a topical cyclosporine prescription. Data analyzed included utilization of topical corticosteroids, oral tetracyclines, and punctal plugs. Results: The analysis included 576,416 patients, accounting for 875,692 dry eye outpatient visits: 74.7% were female, 64.2% were ages 40-69 years, and 84.4% had at least one primary dry eye diagnosis. During 2008–2009, 15.9% of dry eye patients with a primary diagnosis versus 6.5% with no primary diagnosis filled at least one cyclosporine prescription. For patients who filled at least one prescription, the mean months’ supply of cyclosporine filled over 12 months was 4.44. Overall, 33.9% of dry eye patients filled a prescription for topical cyclosporine, topical corticosteroid, or oral tetracycline over 2 years. Conclusion: Patients with a primary dry eye diagnosis were more likely to fill a topical cyclosporine prescription. Although inflammation is key to the pathophysiology of dry eye, most patients seeing a physician for dry eye may not receive anti-inflammatory therapies. Keywords: corticosteroids, cyclosporine, dry eye syndromes, inflammation, medication adherence

  3. Physiological optics in the hummingbird hawkmoth: a compound eye without ommatidia

    Science.gov (United States)

    Warrant; Bartsch; G Nther C

    1999-03-01

    The fast-flying day-active hawkmoth Macroglossum stellatarum (Lepidoptera: Sphingidae) has a remarkable refracting superposition eye that departs radically from the classical principles of Exnerian superposition optics. Unlike its classical counterparts, this superposition eye is highly aspherical and contains extensive gradients of resolution and sensitivity. While such features are well known in apposition eyes, they were thought to be impossible in superposition eyes because of the imaging principle inherent in this design. We provide the first account of a superposition eye where these gradients are not only possible, but also produce superposition eyes of unsurpassed quality. Using goniometry and ophthalmoscopy, we find that superposition images formed in the eye are close to the diffraction limit. Moreover, the photoreceptors of the superposition eyes of M. stellatarum are organised to form local acute zones, one of which is frontal and slightly ventral, and another of which provides improved resolution along the equator of the eye. This angular packing of rhabdoms bears no resemblance to the angular packing of the overlying corneal facets. In fact, this eye has many more rhabdoms than facets, with up to four rhabdoms per facet in the frontal eye, a situation which means that M. stellatarum does not possess ommatidia in the accepted sense. The size of the facets and the area of the superposition aperture are both maximal at the frontal retinal acute zone. By having larger facets, a wider aperture and denser rhabdom packing, the frontal acute zone of M. stellatarum provides the eye with its sharpest and brightest image and samples the image with the densest photoreceptor matrix. It is this eye region that M. stellatarum uses to fixate flower entrances during hovering and feeding. This radical departure from classical Exnerian principles has resulted in a superposition eye which has not only high sensitivity but also outstanding spatial resolution. PMID:9929453

  4. The Mobile City: The planning and design of the Network City from a mobility point of view:

    OpenAIRE

    Rooij, R. M.

    2005-01-01

    Cities have changed. People have changed. The 21st century, western citizens of the world travel more often, with more comfort, and longer distances than ever. History shows that a growing economy leads to a growing human need for communication and mobility. The daily action space of people exceeds by far the borders of their own city or village. The Network City is a reality. The essence of the (practical) field of urban design and planning concerns the making of plans in behalf of the v...

  5. Dexamethasone eye drops containing ?-cyclodextrin-based nanogels.

    Science.gov (United States)

    Moya-Ortega, Maria D; Alves, Tiago F G; Alvarez-Lorenzo, Carmen; Concheiro, Angel; Stefánsson, Einar; Thorsteinsdóttir, Margrét; Loftsson, Thorsteinn

    2013-01-30

    Sustained release aqueous eye drops of dexamethasone, based on cyclodextrin (CD) nanogels, were designed and tested in vivo. ?CD units were cross-linked in the form of nanogels by means of an emulsification/solvent evaporation process. The composition of the nanogels was optimized with regard to drug loading and release rate. The eye drops consisted of an aqueous solution of dexamethasone in 2-hydroxypropyl-?-cyclodextrin (HP?CD) medium containing ?CD nanogels. The nanogel eye drops (containing 25 mg dexamethasone per ml) were tested in rabbits and compared to the commercially available product Maxidex(®) (suspension with 1 mg dexamethasone per ml). One drop administration of the nanogel eye drops resulted in nearly constant dexamethasone concentration for at least 6h in the tear fluid (mean concentration±SD=295±59 ?g/ml) whereas the concentration after administration of Maxidex(®) fell rapidly from 9.72±3.45 ?g/ml 1 h after application to 3.76±3.26 ?g/ml 3 h after application. The maximum dexamethasone concentration in the aqueous humor (2 h after application) was 136±24 mg/ml after application of the nanogel eye drops, and only 44.4±7.8 ?g/ml after application of Maxidex(®). The dexamethasone nanogel eye drops were well tolerated with no macroscopic signs of irritation, redness or other toxic effects. PMID:23149258

  6. Eye-based head gestures for interaction in the car

    DEFF Research Database (Denmark)

    Mardanbeigi, Diako; Witzner Hansen, Dan

    In this paper we suggest using a new method for head gesture recognition in the automotive context. This method involves using only the eye tracker for measuring the head movements through the eye movements when the gaze point is fixed. It allows for identifying a wide range of head gestures that can be used as an alternative input in the multimodal interaction context. Two approaches are described for using this method for interaction with objects inside or outside the car. Some application examples are described where the discrete or continuous head movements in combination with the driver’s visual attention can be used for controlling the objects inside the car.

  7. Efficacy of Chinese Eye Exercises on Reducing Accommodative Lag in School-Aged Children: A Randomized Controlled Trial

    Science.gov (United States)

    Li, Shi-Ming; Kang, Meng-Tian; Peng, Xiao-xia; Li, Si-Yuan; Wang, Yang; Li, Lei; Yu, Jing; Qiu, Li-Xin; Sun, Yun-Yun; Liu, Luo-Ru; Li, He; Sun, Xin; Millodot, Michel; Wang, Ningli

    2015-01-01

    Purpose To evaluate the efficacy of Chinese eye exercises on reducing accommodative lag in children by a randomized, double-blinded controlled trial. Methods A total of 190 children aged 10 to 14 years with emmetropia to moderate myopia were included. They were randomly allocated to three groups: standard Chinese eye exercises group (trained for eye exercises by doctors of traditional Chinese medicine); sham point eye exercises group (instructed to massage on non-acupoints); and eyes closed group (asked to close their eyes without massage). Primary outcome was change in accommodative lag immediately after intervention. Secondary outcomes included changes in corrected near and distant visual acuity, and visual discomfort score. Results Children in the standard Chinese eye exercises group had significantly greater alleviation of accommodative lag (-0.10D) than those in sham point eye exercises group (-0.03D) and eyes closed group (0.07D) (P = 0.04). The proportion of children with alleviation of accommodative lag was significantly higher in the standard Chinese eye exercises group (54.0%) than in the sham point eye exercises group (32.8%) and the eyes closed group (34.9%) (P = 0.03). No significant differences were found in secondary outcomes. Conclusion Chinese eye exercises as performed daily in primary and middle schools in China have statistically but probably clinically insignificant effect in reducing accommodative lag of school-aged children in the short-term. Considering the higher amounts of near work load of Chinese children, the efficacy of eye exercises may be insufficient in preventing myopia progression in the long-term. Trial Registration ClinicalTrials.gov NCT01756287 PMID:25742161

  8. Eye Health and Safety Among Latino Farmworkers

    OpenAIRE

    Verma, Amit; Schulz, Mark R.; Quandt, Sara A.; Robinson, Erin N.; Grzywacz, Joseph G.; Chen, Haiying; Arcury, Thomas A.

    2011-01-01

    Farmworkers face a variety of risk factors for eye injuries. Measures of eye protection use and of eye safety knowledge and beliefs are based on a survey of 300 Latino farmworkers in North Carolina. Few farmworkers report using eye protection (8.3%); most (92.3%) report that employers do not provide eye protection. Approximately 70% report that they are not trained in preventing eye injuries; 81% believe that their chances of getting an eye injury are low. Many farmworkers choose to take risk...

  9. Modelling and design of a capacitive touch sensor for urinary tract infection detection at the point-of-care.

    Science.gov (United States)

    Barbosa, Catia; Tao Dong

    2014-08-01

    Due to great use of touchscreens in mobile telephones and other electronic devices, there has been great evolution in this technology. Its wide applicability makes the touch sensor technology suitable for detection of specific components in urine, responsible for urinary tract infection (UTI). Integration of a touch sensor in a disposable probe tip to be used in UTI detection represents a powerful tool to develop new point-of-care testing (POCT) devices. The simplified structure of an electrodes array touch screen was simulated using the software COMSOL Multiphysics to prove that capacitive based touch screens can be used for detection of UTI. Besides we assumed presence of E.coli, one of the major causes of UTI urine. Results show that global capacitance increases if an E.coli sphere is present near the active electrodes, remaining approximately constant when further apart electrodes are excited. The output simulated voltage varies according to the capacitance value, decreasing when the capacitance is increased. PMID:25571114

  10. Feature matching method study for uncorrected fish-eye lens image

    Science.gov (United States)

    Zhang, Baofeng; Jia, Yanhui; Röning, Juha; Feng, Weijia

    2015-01-01

    Because of the further from the center of image the lower resolution and the severe non-linear distortion are the characteristics of uncorrected fish-eye lens image, the traditional feature matching method can't achieve good performance in the applications of fish-eye lens, which correct distortion firstly and then matches the features in image. Center-symmetric Local Binary Pattern (CS-LBP) is a kind of descriptor based on grayscale information from neighborhood, which has high ability of grayscale invariance and rotation invariance. In this paper, CS-LBP will be combined with Scale Invariant Feature Transform (SIFT) to solve the problem of feature point matching on uncorrected fish-eye image. We first extract the interest points in the pair of fish-eye images by SIFT, and then describe the corresponding regions of the interest points through CS-LBP. Finally the similarity of the regions will be evaluated using the chi-square distance to get the only pair of points. For the specified interest point, the corresponding point in another image can be found out. The experimental results show that the proposed method achieves a satisfying matching performance in uncorrected fish-eye lens image. The study of this article will be useful to enhance the applications of fish-eye lens in the field of 3D reconstruction and panorama restoration.

  11. The genetics of eye colours in an Italian population measured with an objective method for eye colour quantification

    DEFF Research Database (Denmark)

    Pietroni, C.; Andersen, J.D.

    2013-01-01

    Brown and blue eye colours are primarily explained by the single nucleotide polymorphism (SNP) HERC2 rs12913832. However, the genetics of eye colours that appear to be neither blue nor brown are not well understood. In this study, 230 unrelated Italian individuals were typed for 32 SNP loci in pigmentary genes. High resolution digital images of the participants’ eyes were taken and the iris region was successfully extracted with the use of the custom designed software Digital Iris Analysis Tool (DIAT) from 218 of the 230 (95%) images. The software counted the numbers of blue and brown pixels in the iris region and calculated a Pixel Index of the Eye (PIE-score) that described the eye colours quantitatively. The PIE-score ranged from _1 to 1 (brown to blue). We investigated the association of the PIE-scores extracted from the eye images with the genotypes of the 32 pigmentary SNPs. We observed a statistically significant association between the PIE-scores and the SNP loci rs12913832, rs4778241, rs7495174 in the HERC2/OCA2 region and the locus rs16891982 in SLC45A2.

  12. Transpupillary Thermotherapy for Treatment of Choroidal Neovascularisation Secondary to Age-Related Macular Degeneration in Indian Eyes

    Directory of Open Access Journals (Sweden)

    Nagpal Manish

    2003-01-01

    Full Text Available Aim: To evaluate the efficacy of transpupillary thermotherapy (TTT for treatment of subfoveal choroidal neovascularisation (CNV secondary to age-related macular degeneration (AMD, and to define accurate power settings for this procedure in Indian eyes. Methods: A prospective, nonrandomised study of 160 eyes of 144 patients with subfoveal CNV. The laser settings included 2mm spot and 300mw power or 3mm spot and 400-600mw power. Two separate 3mm spots were used in larger lesions. The treatment was given for 60 seconds at each point. Results: Ninety-nine eyes had classic membranes and 61 eyes had occult membranes. Following treatment, 79 of 99 (79.8% classic and 52 of 61 (85% occult membranes regressed. Visual improvement (? 2 lines was seen in 29 (29.3% eyes and 12 (19.6% eyes ; visual stabilisation (1 line in 39 (39.4% eyes, and 35 (57.4% eyes; and reduction of vision (- 2 lines in 31 (31.3% eyes and 14 (22.9% eyes with classic and occult membranes respectively. Mean follow-up was 12 months. One patient suffered inadvertant foveal burn. Conclusion: TTT is effective in the management of subfoveal membranes in Indian eyes. They respond to lower energy levels compared to the Caucasian eyes.

  13. The perception of heading during eye movements

    Science.gov (United States)

    Royden, Constance S.; Banks, Martin S.; Crowell, James A.

    1992-01-01

    Warren and Hannon (1988, 1990), while studying the perception of heading during eye movements, concluded that people do not require extraretinal information to judge heading with eye/head movements present. Here, heading judgments are examined at higher, more typical eye movement velocities than the extremely slow tracking eye movements used by Warren and Hannon. It is found that people require extraretinal information about eye position to perceive heading accurately under many viewing conditions.

  14. Eye gaze in intelligent user interfaces gaze-based analyses, models and applications

    CERN Document Server

    Nakano, Yukiko I; Bader, Thomas

    2013-01-01

    Remarkable progress in eye-tracking technologies opened the way to design novel attention-based intelligent user interfaces, and highlighted the importance of better understanding of eye-gaze in human-computer interaction and human-human communication. For instance, a user's focus of attention is useful in interpreting the user's intentions, their understanding of the conversation, and their attitude towards the conversation. In human face-to-face communication, eye gaze plays an important role in floor management, grounding, and engagement in conversation.Eye Gaze in Intelligent User Interfac

  15. New clinical research strategies in thoracic oncology: clinical trial design, adaptive, basket and umbrella trials, new end-points and new evaluations of response

    Directory of Open Access Journals (Sweden)

    Jessica Menis

    2014-09-01

    Full Text Available In the genomics era, our main goal should be to identify large and meaningful differences in small, molecularly selected groups of patients. Classical phase I, II and III models for drug development require large resources, limiting the number of experimental agents that can be tested and making the evaluation of targeted agents inefficient. There is an urgent need to streamline the development of new compounds, with the aim of identifying “trials designed to learn”, which could lead to subsequent “trials designed to conclude”. Basket trials are often viewed as parallel phase II trials within the same entity, designed on the basis of a common denominator, which can be a molecular alteration(s. Most basket trials are histology-independent and aberration-specific clinical trials. Umbrella trials are built on a centrally performed molecular portrait and molecularly selected cohorts with matched drugs, and can include patients’ randomisation and strategy validation. Beyond new designs, new end-points and new evaluation techniques are also warranted to finally achieve methodology and clinical improvements, in particular within immunotherapy trials.

  16. Judgments of eye level in light and in darkness

    Science.gov (United States)

    Stoper, Arnold E.; Cohen, Malcolm M.

    1986-01-01

    Subjects judged eye level in the light and in the dark by raising and lowering themselves in a dental chair until a stationary target appeared to be at the level of their eyes. This method reduced the possibility of subjects' using visible landmarks as reference points for setting eye level during lighted trials, which may have contributed to artificially low estimates of the variability of this judgment in previous studies. Chair settings were 2.5 deg higher in the dark than in the light, and variability was approximately 66 percent greater in the dark than in the light. These results are discussed in terms of possible interactions of two separate systems, one sensitive to the orientations of visible surfaces and the other sensitive to bodily and gravitational information.

  17. Severe dry-eye syndrome following external beam irradiation

    International Nuclear Information System (INIS)

    There are limited data in the literature on the probability of dry-eye complications according to radiotherapy dose. This study investigates the risk of radiation-induced severe dry-eye syndrome in patients in whom an entire orbit was exposed to fractionated external beam irradiation. Between October 1964 and May 1989, 33 patients with extracranial head and neck tumors received irradiation of an entire orbit. Most patients were treated with 60Co. The dose to the lacrimal apparatus was calculated at a depth of 1 cm from the anterior skin surface, the approximate depth of the major lacrimal gland. The end point of the study was severe dry-eye syndrome sufficient to produce visual loss secondary to corneal opacification, ulceration, or vascularization. Twenty patients developed severe dry-eye syndrome. All 17 patients who received dose ?57Gy developed severe dry-eye syndrome. Three (19%) of 16 patients who received doses ?45 Gy developed severe dry-eye syndrome; injuries in the latter group were much more slower to develop (4 to 11 years) than in the higher dose group, in whom corneal vascularization and opacification were usually pronounced within 9-10 months. There were no data for the range of doses between 45.01 and 56.99 Gy. The data did not suggest an increased risk of severe dry-eye syndrome with increasing age. Data from the current series and the literature are combined to construct a sigmoid dose response curve. The incidence of injury increases ve. The incidence of injury increases from 0% reported after doses ?30 Gy to 100% after doses ?57 Gy. 13 refs., 3 figs., 5 tabs

  18. Point Lepreau

    International Nuclear Information System (INIS)

    Point Lepreau, Atlantic Canada's first nuclear generating station, went critical July 25, 1982. The plant, the first 600-MW CANDU to go into operation, took 96 months to build in spite of the fact that its steam generator tubes had to be replaced because of denting problems. The reactor is the first in Canada to be cooled by sea water; strict environmental protection standards were followed during design and construction. A contract has been signed with a Massachusetss electrical utility and permission has been granted to export electricity to the United States. A second reactor may be built at the site to produce electricity for export. New Brunswick expects to save money by producing electricity from uranium rather than oil, and to benefit in other ways from the use of an advanced technology

  19. Mirror coatings for eye-safe laser generation

    International Nuclear Information System (INIS)

    Eye-safety is of paramount importance in the use of laser-based instruments. Eye safe output at 1.54 micron is very important for various applications such as robot vision, range finding and laser radars in civil and military use. Nonlinear crystals have been used in state-of-the-art rangefinders for providing eye-safe output in the 1550 ± 50 nm band. We present our results on designing a back and a front mirror for eye-safe laser generation at a wavelength of 1538 nm. The back mirror is designed for high transmission at 1067 nm and high reflection at 1351 and 1538 nm. The front mirror is designed for high transmission at 1067 nm, high reflection at 1351 nm and partial reflection at 1538 nm. The optimized design is achieved using titanium dioxide and silicon dioxide layers. In the experiment, the coatings are fabricated by electron beam evaporation on BK7 glass substrates. The characteristics of the coated samples are compared with the results of the calculations, showing good correspondence. The laser mirrors so prepared passed the laser damage and durability tests.

  20. Diretrizes para seleção de projetistas e avaliação da prestação do serviço de projeto de edificações na visão do contratante / Guidelines for designers selection and evaluation of the design service from the building developer point of view

    Scientific Electronic Library Online (English)

    Nathália de, Paula; Celso Carlos, Novaes.

    2010-12-01

    Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A avaliação da prestação do serviço de projeto de edificações pode fomentar a relação entre os contratados (projetistas) e os contratantes (incorporador-construtor). Os resultados advindos da avaliação possibilitam a observação das dificuldades porventura ocorridas durante a prestação do serviço, a [...] análise do desempenho dos contratados, a retroalimentação de informações aos envolvidos, o planejamento de ações de melhorias e a seleção de projetistas em empreendimentos futuros. O objetivo deste trabalho é propor diretrizes para a seleção de projetistas e para a avaliação da PSP, sob a ótica do cliente contratante. Para esse fim, foram realizados estudos de caso em quatro empresas incorporadoras e construtoras e duas empresas de projeto da cidade de São Paulo. Os resultados mostram que as empresas incorporadoras e construtoras possuem suas práticas de seleção e avaliação de projetistas e que as empresas de projeto detêm práticas para avaliação da satisfação do cliente contratante. Ambos os tipos de avaliação mencionados - avaliação dos profissionais de projeto e da satisfação do cliente contratante - apresentam o mesmo objetivo: avaliar a prestação do serviço de projeto. A observação dessas práticas, somada à revisão bibliográfica realizada, contribuíram para a elaboração das diretrizes para a seleção de projetistas e para a avaliação da prestação do serviço de projeto. Abstract in english The evaluation of the building design service can improve the relationship between professionals (designers) and clients (real estate developers or construction companies). The evaluation results allow the observation of the difficulties that may have occurred during service provision, the assessmen [...] t of designers performance, provide feedback for the stakeholders, planning improvement actions, and the selection of designers for future projects. The aim of this study is to propose a set of guidelines for designer selection and design service evaluation from the building developer point of view. Case studies were carried out in four real estate developing companies and two design firms from the city of São Paulo. The results show that the builders and property developers have practices for designer selection and evaluation and that the design companies have practices for evaluating the satisfaction of their clients. Both types of evaluation - designer evaluation and evaluation of the contractor client satisfaction - have similar goals: to evaluate the design service. The observation of those practices and the literature review contributed to the elaboration of guidelines for designer selection and for the evaluation of the design service.

  1. Circuital model for the Maxwell Fish Eye perfect drain

    CERN Document Server

    Gonzalez, Juan C; Minano, Juan C; Benitez, Pablo

    2012-01-01

    Perfect drain for the Maxwell Fish Eye (MFE) is a non-magnetic dissipative region placed in the focal point to absorb all the incident radiation without reflection or scattering. The perfect drain was recently designed as a material with complex electrical permittivity that depends on frequency. However, this material is only a theoretical material, so it can not be used in practical devices. Recently, the perfect drain has been claimed as necessary to achieve super-resolution [Leonhard 2009, New J. Phys. 11 093040], which has increased the interest for practical perfect drains suitable for manufacturing. Here, we analyze the super-resolution properties of a device equivalent to the MFE, known as Spherical Geodesic Waveguide (SGW), loaded with the perfect drain. In the SGW the source and drain are implemented with coaxial probes. The perfect drain is realized using a circuit (made of a resistance and a capacitor) connected to the drain coaxial probes. Super-resolution analysis for this device is done in Comso...

  2. Raman-shifted eye-safe aerosol lidar.

    Science.gov (United States)

    Mayor, Shane D; Spuler, Scott M

    2004-07-01

    The design features of, and first observations from, a new elastic backscatter lidar system at a wavelength of 1543 nm are presented. The transmitter utilizes stimulated Raman scattering in high-pressure methane to convert fundamental Nd:YAG radiation by means of the 1st Stokes shift. The wavelength-converting gas cell features multipass operation and internal fans. Unlike previous lidar developments that used Raman scattering in methane, the pump beam is not focused in the present configuration. This feature prevents optical breakdown of the gas inside the cell. Additionally, the gas cell is injection seeded by a diode to improve conversion efficiency and beam quality. The receiver uses a 40.6-cm-diameter telescope and a 200-microm InGaAs avalanche photodiode. The system is capable of operating in a dual-wavelength mode (1064 and 1543 nm simultaneously) for comparison or in a completely eye-safe mode. The system is capable of transmitting an energy of more than 200 mJ/pulse at 10 Hz. Aerosol backscatter data from vertical and horizontal pointing periods are shown. PMID:15250558

  3. Modeling and simulation of the human eye

    Science.gov (United States)

    Duran, R.; Ventura, L.; Nonato, L.; Bruno, O.

    2007-02-01

    The computational modeling of the human eye has been wide studied for different sectors of the scientific and technological community. One of the main reasons for this increasing interest is the possibility to reproduce eye optic properties by means of computational simulations, becoming possible the development of efficient devices to treat and to correct the problems of the vision. This work explores this aspect still little investigated of the modeling of the visual system, considering a computational sketch that make possible the use of real data in the modeling and simulation of the human visual system. This new approach makes possible the individual inquiry of the optic system, assisting in the construction of new techniques used to infer vital data in medical investigations. Using corneal topography to collect real data from patients, a computational model of cornea is constructed and a set of simulations were build to ensure the correctness of the system and to investigate the effect of corneal abnormalities in retinal image formation, such as Plcido Discs, Point Spread Function, Wave front and the projection of a real image and it's visualization on retina.

  4. Virtual pharmacokinetic model of human eye.

    Science.gov (United States)

    Kotha, Sreevani; Murtomäki, Lasse

    2014-07-01

    A virtual pharmacokinetic 3D model of the human eye is built using Comsol Multiphysics® software, which is based on the Finite Element Method (FEM). The model considers drug release from a polymer patch placed on sclera. The model concentrates on the posterior part of the eye, retina being the target tissue, and comprises the choroidal blood flow, partitioning of the drug between different tissues and active transport at the retina pigment epithelium (RPE)-choroid boundary. Although most straightforward, in order to check the mass balance, no protein binding or metabolism is yet included. It appeared that the most important issue in obtaining reliable simulation results is the finite element mesh, while time stepping has hardly any significance. Simulations were extended to 100,000 s. The concentration of a drug is shown as a function of time at various points of retina, as well as its average value, varying several parameters in the model. This work demonstrates how anybody with basic knowledge of calculus is able to build physically meaningful models of quite complex biological systems. PMID:24721554

  5. Active inference, eye movements and oculomotor delays.

    Science.gov (United States)

    Perrinet, Laurent U; Adams, Rick A; Friston, Karl J

    2014-12-01

    This paper considers the problem of sensorimotor delays in the optimal control of (smooth) eye movements under uncertainty. Specifically, we consider delays in the visuo-oculomotor loop and their implications for active inference. Active inference uses a generalisation of Kalman filtering to provide Bayes optimal estimates of hidden states and action in generalised coordinates of motion. Representing hidden states in generalised coordinates provides a simple way of compensating for both sensory and oculomotor delays. The efficacy of this scheme is illustrated using neuronal simulations of pursuit initiation responses, with and without compensation. We then consider an extension of the generative model to simulate smooth pursuit eye movements-in which the visuo-oculomotor system believes both the target and its centre of gaze are attracted to a (hidden) point moving in the visual field. Finally, the generative model is equipped with a hierarchical structure, so that it can recognise and remember unseen (occluded) trajectories and emit anticipatory responses. These simulations speak to a straightforward and neurobiologically plausible solution to the generic problem of integrating information from different sources with different temporal delays and the particular difficulties encountered when a system-like the oculomotor system-tries to control its environment with delayed signals. PMID:25128318

  6. Eye Health in New Zealand: A Study of Public Knowledge, Attitudes, and Practices Related to Eye Health and Disease

    Science.gov (United States)

    Ahn, Mark J.; Frederikson, Lesley; Borman, Barry; Bednarek, Rebecca

    2011-01-01

    Purpose: This study seeks to measure the public knowledge, attitudes, and practices related to eye health and disease in New Zealand (NZ). Design/methodology/approach: A 22-item survey of 507 adults in NZ was conducted. The survey was developed using interviews and focus groups, as well as comparisons with other benchmark international studies.…

  7. Simulations of Keratoconus Patient Vision with Optical Eye Modeling

    Science.gov (United States)

    Tan, Bo; Chen, Ying-Ling; Lewis, J. W. L.; Shi, Lei; Wang, Ming

    2007-11-01

    Keratoconus (KC) is an eye condition that involves progressive corneal thinning. Pushed by the intraocular pressure, the weakened cornea bulges outward and creates an irregular surface shape. The result is degraded vision that is difficult to correct with regular eye glasses or contact lens. In this study we use the optical lens design software, ZeMax, and patient data including cornea topography and refraction prescription to construct KC eye models. The variation of KC ``cone height'' on the cornea is used to simulate KC progression. The consequent patients' night vision and Snellen letter chart vision at 20 feet are simulated using these anatomically accurate 3-dimensional models. 100 million rays are traced for each image simulation. Animated results illustrate the change of KC visual acuity with the progression of disease. This simulation technique provides a comprehensive tool for medical training and patient consultation/education.

  8. THE SAMPLING ERROR OF ROTATOR ESTIMATES OF EYE VOLUME

    Directory of Open Access Journals (Sweden)

    Matthew G Reed

    2011-05-01

    Full Text Available The vertical rotator is a design based stereological method for estimating object volume using measurements made on co-axial sections. Recently we used the method to estimate eye volume in a number of pathological studies. In the present note we apply an error prediction method for the vertical rotator which has recently been published and analyse the raw data from our earlier study on eye volume in juvenile Dover sole. Application of the new theory allows us to assess the variance contributions due to rotating plane and test line sampling and estimate the underlying biological variability in eye volume. In all cases the coefficient of error introduced by the rotating test was about 10 times greater than due to the test line contribution.

  9. Dorsal eye selector pannier (pnr) suppresses the eye fate to define dorsal margin of the Drosophila eye

    OpenAIRE

    Oros, Sarah M.; Tare, Meghana; Kango-singh, Madhuri; Singh, Amit

    2010-01-01

    Axial patterning is crucial for organogenesis. During Drosophila eye development, dorso-ventral (DV) axis determination is the first lineage restriction event. The eye primordium begins with a default ventral fate, on which the dorsal eye fate is established by expression of the GATA-1 transcription factor pannier (pnr). Earlier, it was suggested that loss of pnr function induces enlargement in the dorsal eye due to ectopic equator formation. Interestingly, we found that in addition to regula...

  10. Systane® lubricant eye drops in the management of ocular dryness

    Science.gov (United States)

    Benelli, Umberto

    2011-01-01

    The understanding of dry eye disease has advanced recently through increasing recognition that the etiology of the condition involves both tear evaporation and insufficient tear production, and that tear film instability and inflammation play roles in the various stages of the disease. Of significance, it has been recognized that lipid layer thickness correlates with tear film stability. The management of dry eye involves various strategies and therapeutic approaches that address one or more etiopathological components of the disease. The purpose of this review is to outline the characteristics and clinical utility of the Systane® ocular lubricants that contain hydroxypropyl-guar and one or both of the demulcents, ie, polyethylene glycol 400 and propylene glycol. Clinically, these products are safe and are indicated for the temporary relief of burning and irritation due to dryness of the eye. In particular, this review describes the formulations, mechanisms of action, and clinical utility of the newest additions to this topical ocular lubricant family, Systane Ultra® and Systane Balance®. Both of these ocular products are formulated with an intelligent delivery system and both provide symptomatic relief to patients with dry eye. However, Systane Balance is a novel formulation that contains both polymer and lipid components designed to protect the ocular surface and replenish tear film lipids simultaneously, a factor that is of particular relevance to patients who have dry eye associated with meibomian gland dysfunction. PMID:21750611

  11. Review of findings of the Andhra Pradesh Eye Disease Study : policy implications for eye-care services.

    Directory of Open Access Journals (Sweden)

    Dandona Lalit

    2001-01-01

    Full Text Available The Andhra Pradesh Eye Disease Study (APEDS was conducted in order to design long-term strategies to reduce blindness in the background of non-availability of recent population-based data on various aspects of blindness. The objectives of APEDS were to determine the prevalence and causes of blindness and visual impairment, prevalence of and risk factors for major eye diseases, barriers to eye-care services, and quality of life among the visually impaired. Multistage sampling was used to select 11,786 subjects of all ages from 24 urban clusters and 70 rural clusters in one urban and three rural areas belonging to different parts of Andhra Pradesh, with the aim of obtaining a study sample representative of the urban-rural and socioeconomic distribution of the population of this state. A total of 10,293 subjects underwent a detailed interview and dilated eye examination by trained professionals. The adjusted prevalence of blindness (presenting visual acuity <6/60 or central visual field <20 degrees in the better eye was 1.84%, and moderate visual impairment (presenting visual acuity <6/18-6/60 or equivalent visual field loss in the better eye was 8.1%. Cataract and refractive error were responsible for 60.3% of blindness and 85.7% of moderate visual impairment. Increasing age, decreasing socioeconomic status, female gender, and rural area of residence were associated with higher risk of blindness. Projections from APEDS suggest that there were 18.7 million blind people in 2000 in India, and that this number is likely to increase to 24.1 million and 31.6 million in 2010 and 2020 respectively, if the current trend continues. This review summarizes the findings of APEDS and discusses the implications of these data on the policy and planning of eye-care services.

  12. Design optimization of an intensity-interrogated long-period fibre grating film sensor operating near the phase-matching turning point

    International Nuclear Information System (INIS)

    The intensity interrogation of a sensitive-film-coated long-period fibre grating (LPFG) operating near the phase-matching turning point (PMTP) is fully investigated. The coated LPFG is designed to operate near the PMTP and a little off resonance by properly selecting the film and grating parameters; the variation of the film refractive index induced by the interaction between the sensitive film and the surrounding medium leads to the change of coupling strength with a fixed resonant wavelength. Based on the coupled-mode theory and a four-layer model, the phase-matching property and the influence of film optical parameters on the turning points are investigated. Furthermore, the determination of the range of a little off resonance is discussed. By analysing the dependence of sensitivity on the film parameters (film refractive index n3 and thickness h3) and the grating structural parameters (grating period ?, length L and average index modulation ?), the optimum parameters for high sensitivity are obtained. The simulation results show that the resolution of film refractive index is available in the order of 10?7 which is comparable to that of the wavelength-interrogated LPFG sensor based on dual-peak resonance, but an expensive optical spectrum analyser can be excluded from the measuring system. (paper)

  13. Tolerance analysis of cross-eye jamming systems

    OpenAIRE

    Du Plessis, W. P.; Odendaal, J. W.; Joubert, Johan

    2011-01-01

    The matching required between the two directions through a retrodirective cross-eye jammer is considered using both the traditional phase-front analysis and an extended analysis. The design parameters to achieve a specified tracking error are derived and an optimal design is proposed. The results for the extended analysis show that the tolerances required to induce large angular errors in a monopulse radar are not as strict as the traditional analysis suggests.

  14. Eye Bank Association of America

    Science.gov (United States)

    ... States, the EBAA is the nationally-recognized accrediting body for eye banks. Since 1961, EBAA member banks have restored sight to over 1,500,000 individuals. Learn More EVENTS 2014 Fall Events - Stayed tuned for updates on the 2015 Fall Meetings!... More ? ...

  15. If I Had - Dry Eyes

    Medline Plus

    Full Text Available ... MD, FACS, MBA, Professor of Ophthalmology, Mount Sinai School of Medicine, New York Back to Home Page VIDEO: If I Had - Dry Eyes - Dr. ... is a Professor of Ophthalmology at Mount Sinai School of Medicine and Director of ... and Refractive Surgery Center at the Mount Sinai Medical Center. In ...

  16. Clearing media for the eye.

    OpenAIRE

    Maurice, D. M.

    1987-01-01

    Non-ionic radiological contrast media have a high refractive index and are not toxic to living cells. They can be used as clearing media for unfixed ocular tissues. Corneal opacities in the rabbit could be made transparent, on a temporary basis, by soaking the stroma in contrast media, and no ill effects on the eye were noted.

  17. If I Had - Dry Eyes

    Medline Plus

    Full Text Available ... is not as easy as we would like it to be we don't have one of ... blood test to come up with a diagnosis. It’s a series of things that are done to ... eyes that indicates damage to the ocular surface. It part of a normal exam but there are ...

  18. Through the Eyes of OKeefe.

    Science.gov (United States)

    Ende-Saxe, Shirley

    1990-01-01

    Maintains that, by the time students reach sixth grade, they are tired of painting flowers. By viewing them through the eyes of the artist, Georgia OKeefe, students interests are revived. Students analyzed her methods and then drew and painted their own large scale paintings. (KM)

  19. Frog eye, ear, and nostril

    Science.gov (United States)

    Ren West (None; )

    2006-08-07

    You can clearly see the frog's eye. There is an air opening near a black spot on the frog's skin. The opening to the frog's ear is covered by the round, tan membrane to the left in the picture. This membrane is called the tympanum.

  20. Eye injury risk associated with remote control toy helicopter blades.

    Science.gov (United States)

    Alphonse, Vanessa D; Kemper, Andrew R; Rowson, Steven; Duma, Stefan M

    2012-01-01

    Eye injuries can be caused by a variety of consumer products and toys. Recently, indoor remote controlled (RC) toy helicopters have become very popular. The purpose of this study is to quantify eye injury risk associated with five commercially available RC toy helicopter blades. An experimental matrix of 25 tests was developed to test five different RC toy helicopter blades at full battery power on six postmortem human eyes. A pressure sensor inserted through the optic nerve measured intraocular pressure. Corneal abrasion was assessed post-impact using fluorescein dye. Intraocular pressure was correlated to injury risk for hyphema, lens damage, retinal damage, and globe rupture using published risk functions. All tests resulted in corneal abrasions; however, no other injuries were observed. The 25 tests produced an increase intraocular pressure between 15.2 kPa and 99.3 kPa (114.3 mmHg and 744.7 mmHg). Calculated blade velocities ranged between 16.0 m/s and 25.4 m/s. Injury risk for hyphema was a maximum of 0.2%. Injury risk for lens damage, retinal damage, and globe rupture was 0.0% for all tests. Blade design parameters such as length and mass did not affect the risk of eye injury. This is the first study to quantify the risk of eye injury from RC toy helicopter blades. While corneal abrasions were observed, more serious eye injuries were neither observed nor predicted to have occurred. Results from this study are critical for establishing safe design thresholds for RC toy helicopter blades so that more serious injuries can be prevented. PMID:22846260

  1. Anesthesia for Adults Having Eye Surgery

    Science.gov (United States)

    Anesthesia for Adults Having Eye Surgery En Español What kinds of anesthesia are available for adults having eye surgery? A “ ... performed and the individual patient. How is general anesthesia administered? General anesthesia is usually given to adults ...

  2. A history of eye gaze tracking

    OpenAIRE

    Ould Mohamed, Abdallahi; Perreira Da Silva, Matthieu; Courboulay, Vincent

    2007-01-01

    Applications that use eye and gaze have recently become increasingly popular in the domain of human-computer interfaces. In this paper, we provide a historical review of eye tracker systems and applications.

  3. Children's Eye Injuries: Prevention and Care

    Science.gov (United States)

    ... can cause serious eye injury, such as paper clips, pencils, scissors, bungee cords, wire coat hangers and ... medication to the eye. A cut or puncture wound should be gently covered. Only in the event ...

  4. Understanding Your Vision: The "Imperfect Eye"

    Science.gov (United States)

    ... Issues Feature: Vision Understanding Your Vision: The "Imperfect Eye" Past Issues / Summer 2008 Table of Contents For ... including an implanted set of lenses. "Keeping your eyes healthy means learning about them and the conditions ...

  5. NIH Study Provides Clarity on Supplements for Protection Against Blinding Eye Disease

    Science.gov (United States)

    ... vision. Before the AREDS2 study finished, manufacturers began marketing supplements based on the study design. In AREDS2, ... in the back of the eye that provide sharp central vision, which is necessary for tasks such ...

  6. Eye-Hand Coordination in Children with High Functioning Autism and Asperger's Disorder Using a Gap-Overlap Paradigm

    Science.gov (United States)

    Crippa, Alessandro; Forti, Sara; Perego, Paolo; Molteni, Massimo

    2013-01-01

    We investigated eye-hand coordination in children with autism spectrum disorders (ASD) in comparison with age-matched normally developing peers. The eye-hand correlation was measured by putting fixation latencies in relation with pointing and key pressing responses in visual detection tasks where a gap-overlap paradigm was used and compared to…

  7. An improved likelihood model for eye tracking

    DEFF Research Database (Denmark)

    Hansen, Dan Witzner; Hammoud, Riad I.

    2007-01-01

    While existing eye detection and tracking algorithms can work reasonably well in a controlled environment, they tend to perform poorly under real world imaging conditions where the lighting produces shadows and the person's eyes can be occluded by e.g. glasses or makeup. As a result, pixel clusters associated with the eyes tend to be grouped together with background-features. This problem occurs both for eye detection and eye tracking. Problems that especially plague eye tracking include head movement, eye blinking and light changes, all of which can cause the eyes to suddenly disappear. The usual approach in such cases is to abandon the tracking routine and re-initialize eye detection. Of course this may be a difficult process due to missed data problem. Accordingly, what is needed is an efficient method of reliably tracking a person's eyes between successively produced video image frames, even in situations where the person's head turns, the eyes momentarily close and/or the lighting conditions are variable. The present paper is directed to an efficient and reliable method of tracking a human eye between successively produced infrared interlaced image frames where the lighting conditions are challenging. It proposes a log likelihood-ratio function of foreground and background models in a particle filter-based eye tracking framework. It fuses key information from even, odd infrared fields (dark and bright-pupil) and their corresponding subtractive image into one single observation model. Experimental validations show good performance of the proposed eye tracker in challenging conditions that include moderate head motion and significant local and global lighting changes. The paper presents also an eye detector that relies on physiological infrared eye responses and a modified version of a cascaded classifier. © 2006 Elsevier Inc. All rights reserved.

  8. Pax6 and eye development in Arthropoda.

    OpenAIRE

    Callaerts, P.; Clements, J.; Francis, C.; Hens, K.

    2006-01-01

    The arthropod compound eye is one of the three main types of eyes observed in the animal kingdom. Comparison of the eyes seen in Insecta, Crustacea, Myriapoda and Chelicerata reveals considerable variation in terms of overall cell number, cell positioning, and photoreceptor rhabdomeres, yet, molecular data suggest there may be unexpected similarities. We review here the role of Pax6 in eye development and evolution and the relationship of Pax6 with other retinal determination genes and signal...

  9. The Electronic Eyes of the Social Capital

    OpenAIRE

    Valdecir Pereira Uveda; Graciane Donadello; Francieli Montanari Gasparin; Janaina Macke

    2011-01-01

    The video camera symbolizes an intelligible system that seeks to replace mechanically thehuman eye, in this paper, entitled “electronic eyes”. People’s reaction when realize that they arebeing observed through the lens of the “electronic eye” are in a variety of ways. Some people getshy, others show themselves off spontaneously, and many of them try to avoid the electroniclens. Can a mechanical eye influence people's behavior? This article examines not only thisissue, but it goes fu...

  10. OrbitView: Eye movement visualization software

    OpenAIRE

    Hong, Simon; Optican, Lance M.; Fitzgibbon, Edmond J.; Zee, David S.; Shaikh, Aasef G.

    2011-01-01

    Measurement of eye movements often helps to diagnose ocular motor disorders in the clinic, and is also used as a research tool in ocular motor, vision and vestibular research. Eye movements, however, are usually recorded without simultaneous video recordings, making offline interpretation difficult. We developed a tool that converts the measured eye movement data into a three-dimensional (3D) movie of eye movements. Having useful functions such as slow-play, pause and exaggeration of the move...

  11. Functional analysis and treatment of eye poking.

    OpenAIRE

    Kennedy, C. H.; Souza, G.

    1995-01-01

    In four studies we analyzed the eye poking of a youth with profound disabilities. In Study 1, a functional analysis showed that eye poking occurred during the no-attention condition, but not during demand, attention or recreation conditions. The analysis did not identify socially mediated variables involved in the maintenance of eye poking; rather, eye poking may have been maintained by consequences produced directly by the response. In Study 2 we had the student wear goggles to prevent poten...

  12. The Eye Specification Network in Drosophila

    OpenAIRE

    Weasner, Brandon P.; Anderson, Jason; Kumar, Justin P.

    2004-01-01

    One of the most exciting revelations in retinal biology is the realization that the molecules and mechanisms that regulate eye development have been conserved in all seeing animals including such diverse organisms as the fruit fly, mouse and man. The emerging commonality among mechanisms used in eye development allows for the use of model systems such as the fruit fly, Drosophila melanogaster, to provide key insights into the development and diseases of the mammalian eye. Eye specification in...

  13. Projection-based head-mounted display with eye tracking capabilities

    Science.gov (United States)

    Curatu, Costin; Hua, Hong; Rolland, Jannick

    2005-08-01

    We propose a novel conceptual design for a Head-Mounted Projection Display (HMPD) with Eye-Tracking (ET) capabilities. We present a fully integrated system that is robust, easy to calibrate, inexpensive, and lightweight. The HMD-ET integration is performed from a low-level optical configuration in order to achieve a compact, comfortable, easy-to-use system. The idea behind the full integration consists of sharing the optical path between the HMD and the Eye-Tracker. Along with lens design and optimization, system level issues such as eye illumination options, hardware alternatives are discussed.

  14. Saliency and eye movements in the perception of natural scenes

    OpenAIRE

    Foulsham, Thomas

    2008-01-01

    Humans inspect the environment around them by selecting a sequence of locations to fixate which will provide information about the scene. How are these locations chosen? The saliency map model suggests that points in the scene are represented topographically and that the likelihood of them being fixated depends on low-level feature contrast. This model makes specific predictions about the way people will move their eyes when looking at natural scenes, although there are few experimental te...

  15. Convergence Insufficiency in Patients Visiting Eye OPD with Headache

    OpenAIRE

    Archana Gupta; Kailwoo, S. K.; Vijayawali

    2008-01-01

    The present study was undertaken to find out the incidence of convergence insufficiency in patientspresenting in eye OPD with chief complaints of headache. Only patients with normal visual acuity andfundus picture were included in this study. All the 100 patients included in this study were subjected todetailed orthoptic examination which included tests for near point of convergence by RAF, Maddox rodtests and synaptophore examination. It was found that a substantial number of patients had co...

  16. Eye Gaze in Creative Sign Language

    Science.gov (United States)

    Kaneko, Michiko; Mesch, Johanna

    2013-01-01

    This article discusses the role of eye gaze in creative sign language. Because eye gaze conveys various types of linguistic and poetic information, it is an intrinsic part of sign language linguistics in general and of creative signing in particular. We discuss various functions of eye gaze in poetic signing and propose a classification of gaze…

  17. A Model of the Human Eye

    Science.gov (United States)

    Colicchia, G.; Wiesner, H.; Waltner, C.; Zollman, D.

    2008-01-01

    We describe a model of the human eye that incorporates a variable converging lens. The model can be easily constructed by students with low-cost materials. It shows in a comprehensible way the functionality of the eye's optical system. Images of near and far objects can be focused. Also, the defects of near and farsighted eyes can be demonstrated.

  18. Functional Analysis and Treatment of Eye Poking.

    Science.gov (United States)

    Kennedy, Craig H.; Souza, Geri

    1995-01-01

    Four studies analyzed eye poking behavior of a youth with profound disabilities. Results demonstrated substantive reductions in the frequency of eye poking when goggles were worn and when a video game was provided as a competing source of visual stimulation and as a reinforcer. Music was less effective in reducing eye poking. (Author/DB)

  19. A low-computational approach on gaze estimation with eye touch system.

    Science.gov (United States)

    Topal, Cihan; Gunal, Serkan; Koçdeviren, Onur; Do?an, Atakan; Gerek, Ömer Nezih

    2014-02-01

    Among various approaches to eye tracking systems, light-reflection based systems with non-imaging sensors, e.g., photodiodes or phototransistors, are known to have relatively low complexity; yet, they provide moderately accurate estimation of the point of gaze. In this paper, a low-computational approach on gaze estimation is proposed using the Eye Touch system, which is a light-reflection based eye tracking system, previously introduced by the authors. Based on the physical implementation of Eye Touch, the sensor measurements are now utilized in low-computational least-squares algorithms to estimate arbitrary gaze directions, unlike the existing light reflection-based systems, including the initial Eye Touch implementation, where only limited predefined regions were distinguished. The system also utilizes an effective pattern classification algorithm to be able to perform left, right, and double clicks based on respective eye winks with significantly high accuracy. In order to avoid accuracy problems for sensitive sensor biasing hardware, a robust custom microcontroller-based data acquisition system is developed. Consequently, the physical size and cost of the overall Eye Touch system are considerably reduced while the power efficiency is improved. The results of the experimental analysis over numerous subjects clearly indicate that the proposed eye tracking system can classify eye winks with 98% accuracy, and attain an accurate gaze direction with an average angular error of about 0.93 °. Due to its lightweight structure, competitive accuracy and low-computational requirements relative to video-based eye tracking systems, the proposed system is a promising human-computer interface for both stationary and mobile eye tracking applications. PMID:23757546

  20. Are 3-D Movies Bad for Your Eyes?

    Medline Plus

    Full Text Available ... Sun Eye Health News Consumer Alerts Are 3-D Movies Bad for Your Eyes? Tweet Eye Health ... computer use and your eyes . Children and 3-D Technology Following the lead of Nintendo, several 3- ...

  1. Are 3-D Movies Bad for Your Eyes?

    Medline Plus

    Full Text Available ... Adults Over 60 Babies, Children & Teenagers Computer Usage Diabetes Diet & Nutrition Eye Injuries Eye Screening Guidelines Home ... Computer Usage & Eye Strain Maintaining Your Sight with Diabetes Sports and Eye Protection Eyesight Risks for Smokers ...

  2. Eye Safety for Emergency Response and Disaster Recovery

    Science.gov (United States)

    ... Safety & Health Topics Publications and Products Programs NIOSH EYE SAFETY Eye Safety for Emergency Response and Disaster Recovery NOTE: ... and Face Protection Devices Standard Z87.1 Common Eye Hazards The most common eye hazards faced by ...

  3. Are 3-D Movies Bad for Your Eyes?

    Medline Plus

    Full Text Available ... Usage & Eye Strain Maintaining Your Sight with Diabetes Sports and Eye Protection Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Water & Contacts Don’ ...

  4. Are 3-D Movies Bad for Your Eyes?

    Medline Plus

    Full Text Available ... the Sun Eye Health News Consumer Alerts Are 3-D Movies Bad for Your Eyes? Tweet Eye ... on computer use and your eyes . Children and 3-D Technology Following the lead of Nintendo, several ...

  5. Are 3-D Movies Bad for Your Eyes?

    Medline Plus

    Full Text Available ... Marijuana for Glaucoma Pregnancy Preventing Eye Injuries Smokers Sports Using Eye Makeup Veterans What Is an Ophthalmologist? ... Usage & Eye Strain Maintaining Your Sight with Diabetes Sports and Eye Protection Eyesight Risks for Smokers Veterans & ...

  6. Reproducibility analysis of measurements with a mechanical semiautomatic eye model for evaluation of intraocular lenses

    Science.gov (United States)

    Rank, Elisabet; Traxler, Lukas; Bayer, Natascha; Reutterer, Bernd; Lux, Kirsten; Drauschke, Andreas

    2014-03-01

    Mechanical eye models are used to validate ex vivo the optical quality of intraocular lenses (IOLs). The quality measurement and test instructions for IOLs are defined in the ISO 11979-2. However, it was mentioned in literature that these test instructions could lead to inaccurate measurements in case of some modern IOL designs. Reproducibility of alignment and measurement processes are presented, performed with a semiautomatic mechanical ex vivo eye model based on optical properties published by Liou and Brennan in the scale 1:1. The cornea, the iris aperture and the IOL itself are separately changeable within the eye model. The adjustment of the IOL can be manipulated by automatic decentration and tilt of the IOL in reference to the optical axis of the whole system, which is defined by the connection line of the central point of the artificial cornea and the iris aperture. With the presented measurement setup two quality criteria are measurable: the modulation transfer function (MTF) and the Strehl ratio. First the reproducibility of the alignment process for definition of initial conditions of the lateral position and tilt in reference to the optical axis of the system is investigated. Furthermore, different IOL holders are tested related to the stable holding of the IOL. The measurement is performed by a before-after comparison of the lens position using a typical decentration and tilt tolerance analysis path. Modulation transfer function MTF and Strehl ratio S before and after this tolerance analysis are compared and requirements for lens holder construction are deduced from the presented results.

  7. Large incidence angle and defocus influence cat's eye retro-reflector

    Science.gov (United States)

    Zhang, Lai-xian; Sun, Hua-yan; Zhao, Yan-zhong; Yang, Ji-guang; Zheng, Yong-hui

    2014-11-01

    Cat's eye lens make the laser beam retro-reflected exactly to the opposite direction of the incidence beam, called cat's eye effect, which makes rapid acquiring, tracking and pointing of free space optical communication possible. Study the influence of cat's eye effect to cat's eye retro-reflector at large incidence angle is useful. This paper analyzed the process of how the incidence angle and focal shit affect effective receiving area, retro-reflected beam divergence angle, central deviation of cat's eye retro-reflector at large incidence angle and cat's eye effect factor using geometrical optics method, and presented the analytic expressions. Finally, numerical simulation was done to prove the correction of the study. The result shows that the efficiency receiving area of cat's eye retro-reflector is mainly affected by incidence angle when the focal shift is positive, and it decreases rapidly when the incidence angle increases; the retro-reflected beam divergence and central deviation is mainly affected by focal shift, and within the effective receiving area, the central deviation is smaller than beam divergence in most time, which means the incidence beam can be received and retro-reflected to the other terminal in most time. The cat's eye effect factor gain is affected by both incidence angle and focal shift.

  8. Graph kernels between point clouds

    OpenAIRE

    Bach, Francis

    2007-01-01

    Point clouds are sets of points in two or three dimensions. Most kernel methods for learning on sets of points have not yet dealt with the specific geometrical invariances and practical constraints associated with point clouds in computer vision and graphics. In this paper, we present extensions of graph kernels for point clouds, which allow to use kernel methods for such ob jects as shapes, line drawings, or any three-dimensional point clouds. In order to design rich and nu...

  9. Eye mechanics and their implications for eye movement control

    OpenAIRE

    Koene, Ansgar Roald

    2002-01-01

    The topic of this thesis is the investigation of the mechanical properties of the oculomotor system and the implications of these properties for eye movement control. The investigation was conducted by means of computer models and simulations. This allowed us to combine data from anatomy, physiology and psychophysics with basic principles of physics (mechanics) and mathematics (geometry). In chapter 2 we investigate the degree to which mechanical and neural non-linearities contribute to t...

  10. Molecular genetic analysis of Drosophila eyes absent mutants reveals an eye enhancer element.

    OpenAIRE

    Zimmerman, J. E.; Bui, Q. T.; Liu, H.; Bonini, N. M.

    2000-01-01

    The eyes absent (eya) gene is critical for normal eye development in Drosophila and is highly conserved to vertebrates. To define regions of the gene critical for eye function, we have defined the mutations in the four viable eya alleles. Two of these mutations are eye specific and undergo transvection with other mutations in the gene. These were found to be deletion mutations that remove regulatory sequence critical for eye cell expression of the gene. Two other viable alleles cause a reduce...

  11. MAPK Target Sites of Eyes Absent Are Not Required for Eye Development or Survival in Drosophila

    OpenAIRE

    Jusiak, Barbara; Abulimiti, Abuduaini; Haelterman, Nele; Chen, Rui; Mardon, Graeme

    2012-01-01

    Eyes absent (Eya) is a highly conserved transcription cofactor and protein phosphatase that plays an essential role in eye development and survival in Drosophila. Ectopic eye induction assays using cDNA transgenes have suggested that mitogen activated protein kinase (MAPK) activates Eya by phosphorylating it on two consensus target sites, S402 and S407, and that this activation potentiates the ability of Eya to drive eye formation. However, this mechanism has never been tested in normal eye d...

  12. Understanding sources of social desirability bias in different modes: Evidence from eye-tracking

    OpenAIRE

    Kaminska, Olena; Foulsham, Tom

    2013-01-01

    Our paper provides an empirical study of whether satisficing is related to social desirability bias using real-world eye-tracking. The method enables detecting latency of eye gazes in web, face-to-face and paper and pencil self-administered (SAQ) modes. Through these we infer respondents' attention to question wording, socially desirable and socially undesirable response scale points. We link the gaze latency measures to responses to understand how respondents arrive at socially desirable or ...

  13. Design support at the front end of the New Service Development (NSD) process :the role of touch-points and service personality in supporting team work and innovation processes

    OpenAIRE

    Clatworthy, Simon

    2013-01-01

    This thesis explores the first stages of New Service Development, and focuses upon the role that design can play to improve the innovation performance of a development team. The work took a ”research by design” approach, that resulted in the design and evaluation of tools and process support, for two specific areas of service innovation. Firstly, how working with the touch-points of a service can improve innovation performance, and secondly the importance of aligning the customer experien...

  14. Penetrating eye injuries in road traffic accidents.

    OpenAIRE

    Patel, B. C.; Morgan, L. H.

    1988-01-01

    A review of all penetrating eye injuries treated by the Manchester Eye Hospital over four years (1 February 1982-31 January 1986) was undertaken. One hundred and ninety-six penetrating eye injuries were seen, of which 16 (8.2%) were due to road traffic accidents. Eight patients (nine eyes) were seen in the 12 months prior to the introduction of the seat-belt legislation on 1 February 1983. None of these patients was wearing a seat-belt whereas two of the eight patients (10 eyes) seen after th...

  15. Eye Movements in Gaze Interaction

    DEFF Research Database (Denmark)

    MØllenbach, Emilie; Hansen, John Paulin

    2013-01-01

    Gaze as a sole input modality must support complex navigation and selection tasks. Gaze interaction combines specific eye movements and graphic display objects (GDOs). This paper suggests a unifying taxonomy of gaze interaction principles. The taxonomy deals with three types of eye movements: fixations, saccades and smooth pursuits and three types of GDOs: static, dynamic, or absent. This taxonomy is qualified through related research and is the first main contribution of this paper. The second part of the paper offers an experimental exploration of single stroke gaze gestures (SSGG). The main findings suggest (1) that different lengths of SSGG can be used for interaction, (2) that GDOs are not necessary for successful completion, and (3) that SSGG are comparable to dwell time selection.

  16. Professional management for eye care

    Directory of Open Access Journals (Sweden)

    AK Sivakumar

    2006-09-01

    Full Text Available IntroductionThe global initiative VISION 2020: The Right to Sight, estimates that only 25 per cent of existing infrastructure is used for eye care, while the target utilisation is set at 90 per cent. This requires a complete reorganisation. Many providers have the potential to significantly enhance their service by adopting professional management practice and new technologies in clinical services. This article addresses this opportunity from a professional management perspective.The responsibilities of a hospital administrator could be broadly classified as managing patient care, functional areas, support services, and developmental work. Eye care providers need to focus on four key areas. Strategic management to enhance the efficiency of their organisations requires: human resources management; quality management; marketing; and financial sustainability.

  17. Eye melanoma ion beam therapy

    International Nuclear Information System (INIS)

    Conservative treatment of eye melanoma includes brachytherapy with different radioactive sources, transscleral local resection, transpupillary thermotherapy, leaser photocoagulation, and external particle radiotherapy. Proton beam therapy of eye melanoma offers the ideal physical properties to deliver apricise and homogeneous dose distribution within the target volume, with preservation of sensitive normal tissues due to the distal fall-off of the dose beyond the spread-out Bragg peak. Treatment of ocular tumors began on 1978 at National Institute of Radiological Sciences (NIRS). This paper focuses on the irradiation technique and the factors affecting the survival and metastatic rate. Information on local control, enucleation rate, and the visual outcome of those patients are also given. (author)

  18. Status of pediatric eye care in India

    Directory of Open Access Journals (Sweden)

    Murthy GVS

    2008-01-01

    Full Text Available Purpose: To document the status of pediatric eye care in India. Materials and Methods: A list of institutions providing eye care was compiled from various sources, including government officials, professional bodies of ophthalmologists, and national and international non-governmental organizations (NGO working in the field of eye care in India. A questionnaire on eye care services was sent to all known eye care institutions in the country. Workshops and regional meetings were organized to maximize response. Validity of data was ensured by observational visits to 10% of the institutions who responded. Results: Out of 1204 institutions contacted, 668 (55.5% responded to the questionnaire. Of these, 192 (28.7% reported that they provided pediatric eye care services. A higher proportion (48.3% of NGO hospitals reported separate pediatric ophthalmology units compared to other providers (P< 0.001. Eighty per cent of advanced care eye hospitals had dedicated outpatient, and 40% had dedicated inpatient facilities for children (P< 0.001. The advanced eye care hospitals attended to a larger number of pediatric clients (P < 0.001, and performed more pediatric eye surgeries compared to secondary and tertiary care hospitals (P < 0.001. Eighty-three per cent of advanced care centers and 72.4% of NGO hospitals had an anesthesiologist for pediatric eye service. Refractive error was the commonest reason for seeking service. The commonest surgical procedure was pediatric cataract surgery followed by squint surgery. Conclusion: Pediatric eye care services are not adequate in India.

  19. Work-related eye injuries and illnesses.

    Science.gov (United States)

    Peate, W F

    2007-04-01

    More than 65,000 work-related eye injuries and illnesses, causing significant morbidity and disability, are reported in the United States annually. A well-equipped eye tray includes fluorescein dye, materials for irrigation and foreign body removal, a short-acting mydriatic agent, and topical anesthetics and antibiotics. The tray should be prepared in advance in case of an eye injury. Eye patching does not improve cornea reepithelialization or discomfort from corneal abrasions. Blunt trauma to the eye from a heavy object can cause a blow-out fracture. Sudden eye pain after working with a chisel, hammer, grinding wheel, or saw suggests a penetrating globe injury. Chemical eye burns require immediate copious irrigation. Nontraumatic causes of ocular illness are underreported; work-related allergic conjunctivitis increasingly has been recognized among food handlers and agriculture workers who are exposed to common spices, fruits, and vegetables. The patient's history of eye injury guides the diagnosis. Primary prevention and patient counseling on proper eye protection is essential because over 90 percent of injuries can be avoided with the use of eye protection. As laser use increases in industry and medical settings, adequate personal protection is needed to prevent cataracts. Outdoor workers exposed to significant ultraviolet rays need sun protection and safety counseling to prevent age-related macular degeneration. Contact lenses do not provide eye protection, and physicians should be familiar with guidelines for the use of contacts in the workplace. PMID:17427615

  20. Indications for eye removal in southern Nigeria.

    Science.gov (United States)

    Ibanga, Affiong; Asana, Uduak; Nkanga, Dennis; Duke, Roseline; Etim, Bassey; Oworu, Olugbemisola

    2013-08-01

    To determine the trend in frequency and clinical indications of surgical removal of eyes in a tertiary eye centre in Calabar, Nigeria. This is a 10-year retrospective review of patients who underwent surgical removal of eyes in a tertiary centre. The clinical records were reviewed (between Jan 2001 and Dec 2010) for demographic data, type of surgery, and clinical indications. A total of 137 eyes were surgically removed within the study period. Of these 46 were children (<16 years). There were 85 males and 52 females giving a M:F ratio of 1.6:1. Clinical indications for surgical eye removal include infective causes (32.1 %; perforated corneal ulcers, endophthalmitis, panophthalmitis), trauma (21.2 %), tumours (21.2 %), anterior staphyloma (13.1 %), and painful blind eyes (9.5 %). Phthisis bulbi, expulsive haemorrhage and aphakic bullous keratopathy accounted for the remaining 2.8 %. The eyes were removed by evisceration (63.5 %), enucleation (29.9 %) and modified exenteration (6.6 %). The commonest indication for eye removal in children was tumour (retinoblastoma). Eye removal in southern Nigeria is often due to infective causes (panophthalmitis and endophthalmitis), perforated corneal ulcer, mechanical trauma (blunt or open globe injury from gunshots or direct trauma), chemical burns, tumours, persistently painful blind eye and anterior staphyloma. Other indications for eye removal were phthisis bulbi, expulsive haemorrhage and aphakic bullous keratopathy. PMID:23275188