WorldWideScience
1

Head and eye movement as pointing modalities for eyewear computers  

DEFF Research Database (Denmark)

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.

Jalaliniya, Shahram; Mardanbeigi, Diako

2014-01-01

2

Eye tracking in user experience design  

CERN Document Server

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...

Romano Bergstorm, Jennifer

2014-01-01

3

Evaluating camouflage design using eye movement data.  

Science.gov (United States)

This study investigates the characteristics of eye movements during a camouflaged target search task. Camouflaged targets were randomly presented on two natural landscapes. The performance of each camouflage design was assessed by target detection hit rate, detection time, number of fixations on display, first saccade amplitude to target, number of fixations on target, fixation duration on target, and subjective ratings of search task difficulty. The results showed that the camouflage patterns could significantly affect the eye-movement behavior, especially first saccade amplitude and fixation duration, and the findings could be used to increase the sensitivity of the camouflage assessment. We hypothesized that the assessment could be made with regard to the differences in detectability and discriminability of the camouflage patterns. These could explain less efficient search behavior in eye movements. Overall, data obtained from eye movements can be used to significantly enhance the interpretation of the effects of different camouflage design. PMID:24139724

Lin, Chiuhsiang Joe; Chang, Chi-Chan; Lee, Yung-Hui

2014-05-01

4

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

OpenAIRE

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...

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

2012-01-01

5

Quickest Change-Point Detection: A Bird's Eye View  

OpenAIRE

We provide a bird's eye view onto the area of sequential change-point detection. We focus on the discrete-time case with known pre- and post-change data distributions and offer a summary of the forefront asymptotic results established in each of the four major formulations of the underlying optimization problem: Bayesian, generalized Bayesian, minimax, and multi-cyclic.

Polunchenko, Aleksey S.; Sokolov, Grigory; Du, Wenyu

2013-01-01

6

Achromatic Interaction Point Design  

Energy Technology Data Exchange (ETDEWEB)

Designers of high-luminosity energy-frontier muon colliders must provide strong beam focusing in the interaction regions. However, the construction of a strong, aberration-free beam focus is difficult and space consuming, and long straight sections generate an off-site radiation problem due to muon decay neutrinos that interact as they leave the surface of the earth. Without some way to mitigate the neutrino radiation problem, the maximum c.m. energy of a muon collider will be limited to about 3.5 TeV. A new concept for achromatic low beta design is being developed, in which the interaction region telescope and optical correction elements, are installed in the bending arcs. The concept, formulated analytically, combines space economy, a preventative approach to compensation for aberrations, and a reduction of neutrino flux concentration. An analytical theory for the aberration-free, low beta, spatially compact insertion is being developed.

Guimei Wang,, Yaroslav Derbenev, S.Alex Bogacz, P. Chevtsov, Andre Afanaciev, Charles Ankenbrandt, Valentin Ivanov, Rolland P. Johnson

2009-05-01

7

Design of optical interconnects inspired in multi-aperture optics based in compound insect eyes  

Science.gov (United States)

Optical interconnection at high-speed and large-capacity transmission of data has the advantage of conveying information at large bandwidths in free space with less crosstalk than electronics. We propose here the design of micro-optical devices based in the multi-aperture compound insect eyes that will transfer a signal as a freespace multichannel point-to-point interconnection. These designs are inspired in the configuration of the superposition refractive compound eye as Gabor superlens by means of the implementation of microlens arrays. In our configuration the design equations, simulations, and optical performance are shown.

Garza-Rivera, Anel; Trevino-Palacios, Carlos G.; Renero-Carrillo, Francisco J.

2012-06-01

8

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

9

Turning points in reactor design  

Energy Technology Data Exchange (ETDEWEB)

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.

Beckjord, E.S.

1995-09-01

10

Imitation of Body Movements Facilitated by Joint Attention through Eye Contact and Pointing in Japanese Monkey  

OpenAIRE

Eye contact and pointing are typical gestures in order to direct another individual's attention toward a target. We previously investigated on Japanese monkeys whether joint attention ability encouraged by eye contact and pointing was associated with the imitation of human's actions. The monkeys with the joint attention skills showed the imitation of human's actions. In the current study, we investigated on a monkey whether joint attention ability also facilitated the imitation of human body-...

Kumashiro, Mari; Yokoyama, Osamu; Ishibashi, Hidetoshi

2008-01-01

11

Dynamical Systems in Circuit Designer's Eyes  

Energy Technology Data Exchange (ETDEWEB)

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)

Odyniec, M.

2011-05-09

12

Heavy ion fusion (HIF) driver point designs  

International Nuclear Information System (INIS)

In this paper we report on two Heavy Ion Fusion (HIF) driver point design studies. The Robust Point Design (Rd) was completed over a year ago, and the Modular Point Design (MPD) is still in progress. The goal of any point design study is to construct a detailed design that is self-consistent and integrated from injector to target. This has been the primary theme of both studies

13

Fiber optic point-source for in-vivo measurement of light transmission and scattering in the eye  

Science.gov (United States)

A fiber optic point-source was designed for in vivo measurement of light transmission and scattering. The point-source consists of an optical fiber, with a core diameter of about 8 micrometers , mounted in a stainless steel cannula. At the tip of the cannula the entrance face of a 1-mm micro prism is fixed. The hypotenuse face of the prism is coated with aluminum and acts as a mirror reflecting the light out through the exit face. The arrangement allows light fed into the optical fiber to be emitted in a direction perpendicular to the axis of the cannula. The cannula is bent to allow its in vivo introduction into the eye at the posterior pole. The prism is positioned close to the retina along the optical axis of the eye. The light is transmitted through the eye in a reversed beam path (from vitreaous towards cornea). In the vitreous, the light source emits within a numerical aperture of about 0.1 allowing the exiting light to be well confined through the dilated pupil. After careful calibration of the light source, accurate measurements can easily be performed by positioning detector equipment outside the eye. The small size of the point-source (in the range of the eye's resolution) allows measurement of light scatter at both wide and narrow angles. With this intraocular fiber optic technique, it is possible to perform several types of experiments, including measurements of light transmission and scattering, and also studies of fluorescence phenomena in different parts of the ocular media.

Soederberg, Per G.; Torstensson, Per-Arne; Beckman, Claes M. E.; Ren, Jianming; Algvere, Peep; Tengroth, Bjorn M.

1994-06-01

14

Dew inspired breathing-based detection of genetic point mutation visualized by naked eye  

Science.gov (United States)

A novel label-free method based on breathing-induced vapor condensation was developed for detection of genetic point mutation. The dew-inspired detection was realized by integration of target-induced DNA ligation with rolling circle amplification (RCA). The vapor condensation induced by breathing transduced the RCA-amplified variances in DNA contents into visible contrast. The image could be recorded by a cell phone for further or even remote analysis. This green assay offers a naked-eye-reading method potentially applied for point-of-care liver cancer diagnosis in resource-limited regions.

Xie, Liping; Wang, Tongzhou; Huang, Tianqi; Hou, Wei; Huang, Guoliang; Du, Yanan

2014-09-01

15

Designing Lithographic Objectives by Constructing Saddle Points:  

OpenAIRE

Optical designers often insert or split lenses in existing designs. Here, we present, with examples from Deep and Extreme UV lithography, an alternative method that consists of constructing saddle points and obtaining new local minima from them. The method is remarkable simple and can therefore be easily integrated with the traditional design techniques. It has significantly improved the productivity of the design process in all cases in which it has been applied so far.

Marinescu, O.; Bociort, F.

2006-01-01

16

Intraocular lens design for treating high myopia based on individual eye model  

Science.gov (United States)

In this research, we firstly design the phakic intraocular lens (PIOL) based on individual eye model with optical design software ZEMAX. The individual PIOL is designed to correct the defocus and astigmatism, and then we compare the PIOL power calculated from the individual eye model with that from the experiential formula. Close values of PIOL power are obtained between the individual eye model and the formula, but the suggested method has more accuracy with more functions. The impact of PIOL decentration on human eye is evaluated, including rotation decentration, flat axis decentration, steep axis decentration and axial movement of PIOL, which is impossible with traditional method. To control the PIOL decentration errors, we give the limit values of PIOL decentration for the specific eye in this study.

Wang, Yang; Wang, Zhaoqi; Wang, Yan; Zuo, Tong

2007-02-01

17

Design of 3D eye-safe middle range vibrometer  

Science.gov (United States)

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.

Polulyakh, Valeriy; Poutivski, Iouri

2014-05-01

18

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

Science.gov (United States)

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.

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

2008-08-01

19

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

OpenAIRE

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 dis...

Pa?l, Andra?s; Me?sza?ros, La?szlo?; Cse?pa?ny, Gergely; Jasko?, Attila; Schlaffer, Ferenc; Vida, Krisztia?n; Mezo?, Gyo?rgy; Do?brentei, La?szlo?; Farkas, Erno?; Kiss, Csaba; Ola?h, Katalin; Rega?ly, Zsolt

2013-01-01

20

Direct Comparison of a Tablet Computer and a Personal Digital Assistant for Point-of-Care Documentation in Eye Care  

OpenAIRE

New mobile computing devices including personal digital assistants (PDAs) and tablet computers have emerged to facilitate data collection at the point of care. Unfortunately, little research has been reported regarding which device is optimal for a given care setting. In this study we created and compared functionally identical applications on a Palm operating system-based PDA and a Windows-based tablet computer for point-of-care documentation of clinical observations by eye...

Silvey, Garry M.; Macri, Jennifer M.; Lee, Paul P.; Lobach, David F.

2005-01-01

21

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

Science.gov (United States)

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.

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

2009-08-01

22

Mars interplanetary trajectory design via Lagrangian points  

Science.gov (United States)

With the increase in complexities of interplanetary missions, the main focus has shifted to reducing the total delta-V for the entire mission and hence increasing the payload capacity of the spacecraft. This paper develops a trajectory to Mars using the Lagrangian points of the Sun-Earth system and the Sun-Mars system. The whole trajectory can be broadly divided into three stages: (1) Trajectory from a near-Earth circular parking orbit to a halo orbit around Sun-Earth Lagrangian point L2. (2) Trajectory from Sun-Earth L2 halo orbit to Sun-Mars L1 halo orbit. (3) Sun-Mars L1 halo orbit to a circular orbit around Mars. The stable and unstable manifolds of the halo orbits are used for halo orbit insertion. The intermediate transfer arcs are designed using two-body Lambert's problem. The total delta-V for the whole trajectory is computed and found to be lesser than that for the conventional trajectories. For a 480 km Earth parking orbit, the total delta-V is found to be 4.6203 km/s. Another advantage in the present approach is that delta-V does not depend upon the synodic period of Earth with respect to Mars.

Eapen, Roshan Thomas; Sharma, Ram Krishan

2014-09-01

23

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

24

Dynamics and mission design near libration points  

CERN Document Server

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

Gómez, G; Llibre, J; Martínez, R

2001-01-01

25

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

DEFF Research Database (Denmark)

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

Bertelsen, Geir; Erke, Maja G

2013-01-01

26

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

OpenAIRE

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...

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

2013-01-01

27

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

CERN Document Server

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.

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

2014-01-01

28

NIF Ignition Target 3D Point Design  

Energy Technology Data Exchange (ETDEWEB)

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.

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

2008-11-05

29

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

30

Status of Fast Ignition Point Design  

International Nuclear Information System (INIS)

Full text: The fast ignition (FI) approach to inertial confinement fusion offers the prospect for achieving the high target gains necessary for an attractive inertial fusion energy system. In the FI scheme a two step approach is used to reach the conditions required to initiate fusion and burn: firstly, a DT-filled capsule is compressed to form a dense core (300 g/cc); secondly, a small region of the core is heated rapidly to ignition temperature (12 keV) with a high-power laser-generated electron beam. A major challenge for FI target design has been the complexity in modeling both the compression and ignition phases self-consistently and at full-scale. We report on progress in the design of a high gain FI target using an integrated suite of codes capable of simulating all aspects of an FI implosion, including fuel compression, ignitor pulse laser-plasma interaction, fast electron generation and transport, core heating, ignition, and burn. We use a cone-in-shell target with an indirect-drive irradiation scheme compatible with the 1.8 MJ National Ignition Facility (NIF) at LLNL. Two-dimensional hohlraum and capsule simulations are performed with the radiation-hydrodynamics code, HYDRA, to optimize the peak density, areal density, and spatial uniformity of the compressed fuel around the cone tip, whilst maintaining its physical integrity. The ultrashort-pulse laser-plasma interaction and fast electron generation is simulated with a three-dimensional explicit particle-in-cell (PIC) code. The subsequent transport of the electrons through the imploding plasma and their heating of the dense core is modeled with a hybrid-PIC electron transport code coupled to the HYDRA code. The PIC calculations predict an over-energetic and divergent electron source that results in low energy coupling to the compressed core and reduced gain. We describe techniques to improve energy coupling and gain through the use of both azimuthal and axial magnetic fields generated through gradients in material resistivity and magnetic compression of initially imposed seed fields. Integrated calculations are used to design and optimize these schemes and determine ignition energy requirements for achieving high fusion gain. (author)

31

An Updated Point Design for Heavy Ion Fusion  

International Nuclear Information System (INIS)

An updated, self-consistent point design for a heavy ion fusion (HIF) power plant based on an induction linac driver, indirect-drive targets, and a thick liquid wall chamber has been completed. Conservative parameters were selected to allow each design area to meet its functional requirements in a robust manner, and thus this design is referred to as the Robust Point Design (RPD-2002). This paper provides a top-level summary of the major characteristics and design parameters for the target, driver, final focus magnet layout and shielding, chamber, beam propagation to the target, and overall power plant

32

An updated point design for heavy ion fusion  

International Nuclear Information System (INIS)

An updated, self-consistent point design for a heavy ion fusion (HIF) power plant based on an induction linac driver, indirect-drive targets, and a thick liquid wall chamber has been completed. Conservative parameters were selected to allow each design area to meet its functional requirements in a robust manner, and thus this design is referred to as the Robust Point Design (RPD-2002). This paper provides a top-level summary of the major characteristics and design parameters for the target, driver, final focus magnet layout and shielding, chamber, beam propagation to the target, and overall power plant

33

A 34-meter VAWT (Vertical Axis Wind Turbine) point design  

Science.gov (United States)

The Wind Energy Division at Sandia National Laboratories recently completed a point design based on the 34-m Vertical Axis Wind Turbine (VAWT) Test Bed. The 34-m Test Bed research machine incorporates several innovations that improve Darrieus technology, including increased energy production, over previous machines. The point design differs minimally from the Test Bed; but by removing research-related items, its estimated cost is substantially reduced. The point design is a first step towards a Test-Bed-based commercial machine that would be competitive with conventional sources of power in the mid-1990s.

Ashwill, T. D.; Berg, D. E.; Dodd, H. M.; Rumsey, M. A.; Sutherland, H. J.; Veers, P. S.

34

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)

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.

G.V. Sorokoletov

2013-02-01

35

Design of Floating Point Arithmetic Logic Unit with Universal Gate  

OpenAIRE

A floating point arithmetic and logic unit design using pipelining is proposed. By using pipeline with ALU design, ALU provides a high performance. With pipelining plus parallel processing concept ALU execute multiple instructions simultaneously. Floating point ALU unit is formed by combination of arithmetic modules (addition, subtraction, multiplication, division), Universal gate module. Each module is divided into sub-module. Bits selection determines which operation takes place at a partic...

Zanjat, Shraddha N.; Chede, Dr S. D.; Chilke, Prof B. J.

2014-01-01

36

Designing AAC systems for children with autism: evidence from eye tracking research.  

Science.gov (United States)

Autism is associated with a range of language difficulties that impact communication, behaviour management, and education. Consequently, a variety of augmentative and alternative communication (AAC) strategies may be employed to support people with autism to communicate. There is a growing body of evidence concerning the visual attention of individuals with autism, which may be relevant to AAC interventions. This review draws on evidence from eye tracking research specifically to inform the design of AAC systems for people with autism. In addition, we discuss the future of AAC for individuals with autism in light of relevant technological developments, and raise questions for future research. PMID:24785660

Gillespie-Smith, Karri; Fletcher-Watson, Sue

2014-06-01

37

Design of a population-based study of visual impairment in India : The Andhra Pradesh eye disease study  

Directory of Open Access Journals (Sweden)

Full Text Available Reliable population-based epidemiologic data regarding vision and ocular morbidity, as well as those about the perceptions of people regarding visual impairment and eye care, are lacking for the most part in the developing world including India. These data are the basis on which effective eye care services can be developed. To meet this need we designed the Andhra Pradesh Eye Disease Study, a population-based epidemiology study of 10,000 people in the Indian state of Andhra Pradesh. The design of this study is described in this paper. Various options for the sample size, study areas, sampling procedure, and recruitment of subjects were considered. A sample size of 10,000 people, 5,000 each in the < or = 30 and > 30 years age groups, was determined to obtain reasonable confidence in estimating the prevalence of diseases and odds ratios for risk factors of interest. A multistage sampling strategy was chosen for the study which was assumed to give a design effect of 1.5 for the estimates. One urban area, Hyderabad, and three rural areas, West Godavari, Adilabad and Mahbubnagar districts, were selected in Andhra Pradesh. Interview instruments were developed to obtain detailed information about demographic data, diet, ocular and systemic history, risk factors for eye diseases, visual function, quality of life, barriers to eye care, and knowledge about eye diseases. A detailed examination procedure was devised to obtain a broad range of normative and abnormal data related to eyes and vision. A protocol was developed for doing automated visual fields, slitlamp and fundus photography. Computer databases were made in FoxPro for data entry and subsequent analysis with SPSS. Pilot studies were done to test the instruments, procedures, and logistics of the study in urban and rural areas. Information from the Andhra Pradesh Eye Disease Study is expected to help in planning and implementation of effective long-term preventive, curative, and rehabilitative eye care services in Andhra Pradesh.

Dandona Rakhi

1997-01-01

38

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)

39

Progress and prospects for an IFE relevant FI point design  

Directory of Open Access Journals (Sweden)

Full Text Available 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.

Key M.

2013-11-01

40

Progress and prospects for an FI relevant point design  

Energy Technology Data Exchange (ETDEWEB)

The physics issues involved in scaling from sub ignition to high gain fast ignition are discussed. Successful point designs must collimate the electrons and minimize the stand off distance to avoid multi mega-joule ignition energies. Collimating B field configurations are identified and some initial designs are explored.

Key, M; Amendt, P; Bellei, C; Clark, D; Cohen, B; Divol, L; Ho, D; Kemp, A; Larson, D; Marinak, M; Patel, P; Shay, H; Strozzi, D; Tabak, M

2011-11-02

41

Design of a reversible single precision floating point subtractor.  

Science.gov (United States)

In recent years, Reversible logic has emerged as a major area of research due to its ability to reduce the power dissipation which is the main requirement in the low power digital circuit design. It has wide applications like low power CMOS design, Nano-technology, Digital signal processing, Communication, DNA computing and Optical computing. Floating-point operations are needed very frequently in nearly all computing disciplines, and studies have shown floating-point addition/subtraction to be the most used floating-point operation. However, few designs exist on efficient reversible BCD subtractors but no work on reversible floating point subtractor. In this paper, it is proposed to present an efficient reversible single precision floating-point subtractor. The proposed design requires reversible designs of an 8-bit and a 24-bit comparator unit, an 8-bit and a 24-bit subtractor, and a normalization unit. For normalization, a 24-bit Reversible Leading Zero Detector and a 24-bit reversible shift register is implemented to shift the mantissas. To realize a reversible 1-bit comparator, in this paper, two new 3x3 reversible gates are proposed The proposed reversible 1-bit comparator is better and optimized in terms of the number of reversible gates used, the number of transistor count and the number of garbage outputs. The proposed work is analysed in terms of number of reversible gates, garbage outputs, constant inputs and quantum costs. Using these modules, an efficient design of a reversible single precision floating point subtractor is proposed. Proposed circuits have been simulated using Modelsim and synthesized using Xilinx Virtex5vlx30tff665-3. The total on-chip power consumed by the proposed 32-bit reversible floating point subtractor is 0.410 W. PMID:24455466

Anantha Lakshmi, Av; Sudha, Gf

2014-01-01

42

Design and Implementation of Complex Floating Point Processor Using FPGA  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents complete processor hardware with three arithmetic units. The first arithmetic unit canperform 32-bit integer arithmetic operations. The second unit can perform arithmetic operations such asaddition, subtraction, multiplication, division, and square root on 32-bit floating point numbers. The thirdunit can perform arithmetic operations such as addition, subtraction, multiplication on complex numbers.The specific advancement in this processor is the new architecture introduced for complex arithmetic unit.In general complex floating point arithmetic hardware consists of floating to fixed and fixed to floatingconversions. But using such hardware will lead to compromise between accuracy and number of bits usedto represent the fixed point equivalent of floating point numbers. The proposed architecture avoids thatcompromise and it is implemented with less number of look-up tables to save around 5500 logic gates. Thecomplex numbers are represented using a subset of IEEE754 standard floating point format, 16-bits forreal part and 16-bits for imaginary part. The floating point arithmetic unit works on 32-bit IEEE754 singleprecision numbers. The instruction set is specially designed to support integer, floating point and complexfloating point arithmetic operations. The on-chip RAM is 8kBytes and is extendable up to 64kBytes. As theprocessor is designed to implement on FPGA, the embedded block RAMs are utilized as RAM.

Murali Krishna Pavuluri

2013-10-01

43

Effects of labeling and pointing on object gaze in boys with fragile X syndrome: an eye-tracking study.  

Science.gov (United States)

We examined the visual processing of a social learning stimulus and the ways in which visual attention was distributed to objects as well as to the examiner's face during word learning under conditions that varied only in the presence or absence of a label. The goal of the current study, then, was to evaluate the effects of differentially providing pointing and labeling during exposure to a novel target object in males with fragile X syndrome (FXS) (n=14, ages 4.33-10.02), autism spectrum disorder (ASD) (n=17, ages 4.04-10.4), or typical development (TD) (n=18, ages 2.05-5.33). In particular, the present study examined attention to the examiner's face as well as target and distracter objects that were presented as video stimuli. An eye-tracker captured gaze to the video stimuli as they were shown in order to examine the way in which children with FXS, ASD, or TD distributed their gaze toward the examiner and the objects. Results indicated that no group showed increased gaze toward the target object compared to the distracter object. However, results revealed that participants with FXS showed significantly increased face gaze compared to the novel objects, whereas children with ASD and TD both showed similar amounts of relative gaze toward the face and objects. Furthermore, the act of pointing at the target object was found to increase gaze toward the target objects compared to when there was no pointing in all groups. Together, these findings suggest that social cues like those employed in a word-learning task, when presented with video, may relate to gaze in FXS in context- or task-dependent ways that are distinct from those expected during live interaction. PMID:25062097

Benjamin, David P; Mastergeorge, Ann M; McDuffie, Andrea S; Kover, Sara T; Hagerman, Randi J; Abbeduto, Leonard

2014-11-01

44

Change-point in stochastic design regression and the bootstrap  

OpenAIRE

In this paper we study the consistency of different bootstrap procedures for constructing confidence intervals (CIs) for the unique jump discontinuity (change-point) in an otherwise smooth regression function in a stochastic design setting. This problem exhibits nonstandard asymptotics and we argue that the standard bootstrap procedures in regression fail to provide valid confidence intervals for the change-point. We propose a version of smoothed bootstrap, illustrate its re...

Seijo, Emilio; Sen, Bodhisattva

2011-01-01

45

Generalizations of fuzzy linguistic control points in geometric design  

Science.gov (United States)

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.

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

2014-07-01

46

Professional SharePoint 2010 Branding and User Interface Design  

CERN Document Server

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

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

2010-01-01

47

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

Science.gov (United States)

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

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

2013-01-01

48

Design of Floating Point Arithmetic Logic Unit with Universal Gate  

Directory of Open Access Journals (Sweden)

Full Text Available A floating point arithmetic and logic unit design using pipelining is proposed. By using pipeline with ALU design, ALU provides a high performance. With pipelining plus parallel processing concept ALU execute multiple instructions simultaneously. Floating point ALU unit is formed by combination of arithmetic modules (addition, subtraction, multiplication, division, Universal gate module. Each module is divided into sub-module. Bits selection determines which operation takes place at a particular time. In this design of universal gate perform logical operation such as AND,OR,NOT,NOR,NAND operation also in this work area and delay parameter are reduces. The design is and validated using vhdl simulation in the xilinx13.1i software.

Shraddha N. Zanjat

2014-06-01

49

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

Science.gov (United States)

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.

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

2007-01-01

50

Using saddle points for challenging optical design tasks  

Science.gov (United States)

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.

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

2014-09-01

51

DESIGN POINT PERFORMANCE OF TURBOJET AND TURBOFAN ENGINE CYCLES  

Science.gov (United States)

This program is one designed for the calculation of design-point performance of turbojet and turbofan engine cycles. This program requires as input the airplane Mach number, the altitude-state equations, turbine-inlet temperature, afterburner temperature, duct burner temperature, bypass ratio, coolant flow, component efficiences, and component pressure ratios. The output yields specific thrust, specific fuel consumption, engine efficiency, and several component temperatures and pressures. The thermodynamic properties of the gas are expressed as functions of temperature and fuel-to-air ratio. The program is provided with an example case. The program has been implemented on the IBM 7094.

Vanco, M. R.

1994-01-01

52

A superlinear interior points algorithm for engineering design optimization  

Science.gov (United States)

We present a quasi-Newton interior points algorithm for nonlinear constrained optimization. It is based on a general approach consisting of the iterative solution in the primal and dual spaces of the equalities in Karush-Kuhn-Tucker optimality conditions. This is done in such a way to have primal and dual feasibility at each iteration, which ensures satisfaction of those optimality conditions at the limit points. This approach is very strong and efficient, since at each iteration it only requires the solution of two linear systems with the same matrix, instead of quadratic programming subproblems. It is also particularly appropriate for engineering design optimization inasmuch at each iteration a feasible design is obtained. The present algorithm uses a quasi-Newton approximation of the second derivative of the Lagrangian function in order to have superlinear asymptotic convergence. We discuss theoretical aspects of the algorithm and its computer implementation.

Herskovits, J.; Asquier, J.

1990-01-01

53

Eye Allergies  

Science.gov (United States)

... What Is an Ophthalmologist? Your Eyes & the Sun Eye Health News Consumer Alerts What Are Eye Allergies? Tweet ... Get eye MD-reviewed tips and information about eye health and preserving your vision. Privacy Policy Email address © ...

54

Oil-points - Designers means to evaluate sustainability of concepts  

DEFF Research Database (Denmark)

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.

Bey, Niki; Lenau, Torben Anker

1998-01-01

55

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

56

Change-point in stochastic design regression and the bootstrap  

CERN Document Server

In this paper we study the consistency of different bootstrap procedures for constructing confidence intervals (CIs) for the unique jump discontinuity (change-point) in an otherwise smooth regression function in a stochastic design setting. This problem exhibits nonstandard asymptotics and we argue that the standard bootstrap procedures in regression fail to provide valid confidence intervals for the change-point. We propose a version of smoothed bootstrap, illustrate its remarkable finite sample performance in our simulation study, and prove the consistency of the procedure. The $m$ out of $n$ bootstrap procedure is also considered and shown to be consistent. We also provide sufficient conditions for any bootstrap procedure to be consistent in this scenario.

Seijo, Emilio

2011-01-01

57

Eye design and color signaling in a stomatopod crustacean Gonodactylus smithii.  

Science.gov (United States)

Many species of stomatopod crustaceans have multiple spectral classes of photoreceptors in their retinas. Behavioral evidence also indicates that stomatopods are capable of discriminating objects by their spectral differences alone. Most animals use only two to four different types of photoreceptors in their color vision systems, typically with broad sensitivity functions, but the stomatopods apparently include eight or more narrowband photoreceptor classes for color recognition. It is also known that stomatopods use several colored body regions in social interactions. To examine why stomatopods may be so 'concerned' with color, we measured the absorption spectra of visual pigments and intrarhabdomal filters, and the reflectance spectra from different parts of the bodies of several individuals of the gonodactyloid stomatopod species, Gonodactylus smithii. We then applied a model of multiple dichromatic channels for color encoding to examine whether the finely tuned color vision was specifically co-evolved with their complex color signals. Although the eye design of stomatopods seems suitable for detecting color signals of their own, the detection of color signals from other animals, such as reef fishes, can be enhanced as well. Color vision in G. smithii is therefore not exclusively adapted to detect its own color signals, but the spectral tuning of some photoreceptors (e.g. midband Rows 2 and 3) enhances the contrast of certain color signals to a large enough degree to make co-evolution between color vision and these rather specific color signals likely. PMID:11111137

Chiao, C C; Cronin, T W; Marshall, N J

2000-08-01

58

Design considerations for optical pointing and scanning mechanisms  

Science.gov (United States)

Optical pointing and scanning mechanisms require inter-related optical, mechanical and electrical engineering and manufacturing disciplines. Such devices are employed in extremely diversified fields of photographic imaging, forward looking infrared (FLIR) systems, laser projection displays (LPD), target acquisition, aerial reconnaissance, remote sensing, and free space laser telecom. The degrees of freedom commonly applied include rotary scanning, raster and vector scanning, and limited angle gimbals. Support systems include flexures, ball bearings, and gas bearings. The performance of the optical payload supported by the pointing or scanning mechanism is paramount and dominates the process of materials selection, structural analysis, actuator selection, and control system development. This paper introduces the tradeoffs among range and type of motion, actuator types, angular sensor types, bearing types, and control systems applied to these types of systems. Actual product design and performance data is presented for a high-speed rotary scanner, a fast "nodding" scanner for a FLIR, a flexure supported fast steering mirror (FSM), and several ball bearing and a gas bearing gimbal designs.

Sweeney, Michael N.; Erdelyi, Emery; Ketabchi, Mehrdad; Kent, Blanche

2003-10-01

59

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

Science.gov (United States)

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.

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

2012-06-01

60

Design of the TOPEX Earth Pointing Safe Hold Mode  

Science.gov (United States)

A technical description of the design and analysis of the Earth Pointing Safe Hold mode (EPSHM) for the Ocean Topography Experiment (TOPEX) satellite is presented. The EPSHM serves as the primary hardwired analog backup controller for safe-haven satellite operations in the event of on-orbit anomalies. The EPSHM is a modified version of the baseline Multimission Modular Satellite (MMS) EPSHM used on the Landsat-4 mission. Modifications to the MMS baseline EPSHM used on Landsat-4 were required to satisfy the unique TOPEX operational requirements. One such TOPEX operational requirement is that the EPSHM provide a spacecraft yaw-axis slewing capability to maintain adequate illumination of the solar array. The EPSHM architecture, constituent hardware components, performance requirements and predicted on-orbit performance are described.

Dennehy, C. J.; Williams, R. J.; Lee, B. B.; Welch, R. V.

1989-01-01

61

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

62

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

63

Fast ignition integrated experiments and high-gain point design  

Science.gov (United States)

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.

Shiraga, H.; Nagatomo, H.; Theobald, W.; Solodov, A. A.; Tabak, M.

2014-05-01

64

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%.

65

Eye Complications  

Science.gov (United States)

... well if you begin them right away. Eye Insight To understand what happens in eye disorders, it ... remove the lens of the eye. Sometimes the patient gets a new transplanted lens. In people with ...

66

Dry Eye  

Science.gov (United States)

... the Clinical Director Education Programs All Education National Eye Health Education Program Diabetic Eye Disease Education Program Glaucoma ... by the lacrimal gland, are necessary for overall eye health and clear vision. Tears bathe the surface of ...

67

Eye Diseases  

Science.gov (United States)

... the back of the eye Macular degeneration - a disease that destroys sharp, central vision Diabetic eye problems ... defense is to have regular checkups, because eye diseases do not always have symptoms. Early detection and ...

68

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Opening Champagne Bottles To open the bottle safely, point ... detailed 20/20 vision is essential for your job or leisure activities, consider whether 20/40 vision ...

69

Black Eye  

Science.gov (United States)

... Eye) Astigmatism Bacterial Keratitis Bell's Palsy Blepharitis Cataracts Contact Lens-Related Infections Detached & Torn Retina Diabetic Retinopathy Dry Eye Floaters & Flashes Glaucoma Hyperopia (Farsightedness) Low Vision ...

70

Teach Graphic Design Basics with PowerPoint  

Science.gov (United States)

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…

Lazaros, Edward J.; Spotts, Thomas H.

2007-01-01

71

Quantifying patterns of dynamics in eye movement to measure goodness in organization of design elements in interior architecture  

Science.gov (United States)

Architecture brings together diverse elements to enhance the observer's measure of esthetics and the convenience of functionality. Architects often conceptualize synthesis of design elements to invoke the observer's sense of harmony and positive affect. How does an observer's brain respond to harmony of design in interior spaces? One implicit consideration by architects is the role of guided visual attention by observers while navigating indoors. Prior visual experience of natural scenes provides the perceptual basis for Gestalt of design elements. In contrast, Gestalt of organization in design varies according to the architect's decision. We outline a quantitative theory to measure the success in utilizing the observer's psychological factors to achieve the desired positive affect. We outline a unified framework for perception of geometry and motion in interior spaces, which integrates affective and cognitive aspects of human vision in the context of anthropocentric interior design. The affective criteria are derived from contemporary theories of interior design. Our contribution is to demonstrate that the neural computations in an observer's eye movement could be used to elucidate harmony in perception of form, space and motion, thus a measure of goodness of interior design. Through mathematical modeling, we argue the plausibility of the relevant hypotheses.

Mirkia, Hasti; Sangari, Arash; Nelson, Mark; Assadi, Amir H.

2013-03-01

72

Design and Simulation of Floating Point Multiplier Based on VHDL  

Science.gov (United States)

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.

Remadevi, R.

2013-03-01

73

Microsoft SharePoint 2007 technologies planning, design and implementation  

CERN Document Server

SharePoint provides a vital service to businesses--content sharing over Intranet and Internet sites. Microsoft is investing tons of research and development money into content sharing technologies: SharePoint is the "next big thing" for MS Office users, especially in a world where many work teams are becoming geographically dispersed. SharePoint 2007 is a big improvement over former releases, due to enhanced security, better search capabilities, and more robust functionality. Lots of change means that users will have to come up to speed on the new enhancements.With SharePoint 2007 Technologies, readers will gain a working knowledge of the architecture, administration, and end user features offered by SharePoint 2007. This book also provides practical techniques to help IT professionals integrate Sharepoint with other MS products such as Exchange Server. The expertise of the authors, who have helped many businesses leverage Microsoft technologies, makes this book an invaluable tool to anyone interested in depl...

Laahs, Kevin; Vanamo, Veli-Matti

2010-01-01

74

Design study of floating point systolic VLSI chip  

Science.gov (United States)

The objective of this program was to investigate the feasibility of building a floating point processor (24-bit mantissa and 8-bit exponent) on a single ship based on the Hughes Research Laboratories (HRL) present 28-bit fixed point chip (Multiplication Oriented Processor or MOP chip). The plan was to generate any necessary cell logic, layout, or simulations in order to estimate the size of the chip and predict its performance. Since division and square root were not included in the HRL MOP chip, arithmetic algorithms for performing these operations were to be studied.

Nash, J. G.; Nudd, G. R.

1984-03-01

75

Design and Implementation of IEEE-754 Addition and Subtraction for Floating Point Arithmetic Logic Unit  

Directory of Open Access Journals (Sweden)

Full Text Available This paper describes the FPGA implementation of a Decimal Floating Point (DFP adder/subtractor using IEEE 754-2008 format. In this paper we describe an efficient implementation of an IEEE 754 single precision Standard for Binary Floating-Point Arithmetic to include specifications for decimal floating-point arithmetic. As processor support for decimal floating-point arithmetic emerges, it is important to investigate efficient algorithms and hardware designs for common decimal floating-point arithmetic algorithms. This paper presents novel designs for a decimal floating-point addition and subtraction. They are fully synthesizable hardware descriptions in VERILOG. Each one is presented for high speed computing.

V.VINAY CHAMKUR , Chetana.R

2012-06-01

76

Design and Implementation of IEEE-754 Addition and Subtraction for Floating Point Arithmetic Logic Unit  

OpenAIRE

This paper describes the FPGA implementation of a Decimal Floating Point (DFP) adder/subtractor using IEEE 754-2008 format. In this paper we describe an efficient implementation of an IEEE 754 single precision Standard for Binary Floating-Point Arithmetic to include specifications for decimal floating-point arithmetic. As processor support for decimal floating-point arithmetic emerges, it is important to investigate efficient algorithms and hardware designs for common decimal floating-point a...

V Vinay Chamkur, Chetana R.

2012-01-01

77

Comparison of refractive error in eyes with vitrectomy, silicone oil tamponade finished phacoemulsification and intraocular lens implantation in different time point  

Directory of Open Access Journals (Sweden)

Full Text Available AIM: To compare the refractive error in eyes with vitrectomy and silicone oil tamponade finished phacoemulsification and intraocular lens(IOLimplantation in different time point. METHODS: Fifty-one patients(51 eyeswith vitrectomy and silicone oil tamponade performed phacoemulsification and IOL implantation were retrospectively analysed during 2009-01/2011-12 and divided into three groups by different time point of phacoemulsification and IOL implantation. There were 17 cases in A group performed silicone oil tamponade after vitrectomy combined with phacoemulsification and intraocular lens IOL implantation, silicone oil removal was performed after 3-6 months; 13 cases in B group performed silicone oil removal combined with phacoemulsification and IOL implantation; 21 cases in C group of scheduled phacoemulsification and IOL implantation after silicone oil removal, refractive error was compared 3months postoperatively. RESULTS: The average absolute value of refractive error was 0.873±0.256D in A group, 0.828±0.134D in B group, 0.473±0.121D in C group. There was no statistical significant difference compared with A group and B group(P>0.05, but there was statistical significant difference compared with C group and A, B group(PCONCLUSION: Axial length was measured by A Scan ultrasonograph. The refractive error was small in group of phacoemulsification and IOL implantation after silicone oil removal relatively.

Qian Shi

2013-06-01

78

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)

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

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

2014-04-01

79

Design of Farthest-Point Masks for Image Halftoning  

Directory of Open Access Journals (Sweden)

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.

Ramponi G

2004-01-01

80

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

DEFF Research Database (Denmark)

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.

Stefani, Alessio; Stecher, Matthias

2012-01-01

81

Design and Implementation of Complex Floating Point Processor Using FPGA  

OpenAIRE

This paper presents complete processor hardware with three arithmetic units. The first arithmetic unit canperform 32-bit integer arithmetic operations. The second unit can perform arithmetic operations such asaddition, subtraction, multiplication, division, and square root on 32-bit floating point numbers. The thirdunit can perform arithmetic operations such as addition, subtraction, multiplication on complex numbers.The specific advancement in this processor is the new architecture introduce...

Murali Krishna Pavuluri; Krishna Prasad, T. S. R.; Ch Rambabu

2013-01-01

82

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

Directory of Open Access Journals (Sweden)

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.

Irma Shayana Samaden

2014-10-01

83

Phase-shifting point diffraction interferometer phase grating designs  

Science.gov (United States)

Diffraction phase gratings are employed in phase-shifting point diffraction interferometers to improve the interferometric fringe contrast. The diffraction phase grating diffracts a zeroth-order diffraction of light at a first power level to the test-beam window of a mask that is positioned at the image plane and a first-order diffraction at a second power to the reference-beam pinhole. The diffraction phase grating is preferably selected to yield a desired ratio of the first power level to second power level.

Naulleau, Patrick (Oakland, CA)

2001-01-01

84

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

85

Eye Cancer  

Science.gov (United States)

... t y g H Types of Cancer Navigating Cancer Care Coping and Emotions Research and Advocacy Survivorship Blog About Us s You are here Home > Types of Cancer > Eye Cancer > Eye Cancer: Overview Request Permissions Download ...

86

Eye Coordination  

Science.gov (United States)

... Z Listing Good Vision For Life Infants Children Adults Seniors Caring for Your Vision Eye & Vision Exams Contact Lenses Diet and Nutrition UV Protection Resources for Teachers 3D Vision & Eye Health Classroom Exercises ...

87

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 ...

88

Using Eye Makeup  

Science.gov (United States)

... Health News Consumer Alerts Using Eye Makeup Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During ... and Eye Protection Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Opening Champagne Bottles ...

89

LASIK - Laser Eye Surgery  

Science.gov (United States)

Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During Pregnancy Computer Usage & Eye Strain Maintaining Your Sight ... and Eye Protection Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Opening Champagne Bottles ...

90

Eye Tracking as Interface for the Design of Generative Visual Forms and Patterns  

OpenAIRE

When working with generative systems, designers enter into a loop of discrete steps; external evaluations of the output feedback into the system, and new outputs are subsequently reevaluated. In such systems, interacting low level elements can engender a difficult to predict emergence of macro-level characteristics. Furthermore, the state space of some systems can be vast. Consequently, designers generally rely on trial-and-error, experience or intuition in selecting pa...

Ekeus, Henrik; Plumbley, Mark D.; Mcowan, Peter W.

2012-01-01

91

Supersonic Aerodynamic Design Improvements of an Arrow-Wing HSCT Configuration Using Nonlinear Point Design Methods  

Science.gov (United States)

This paper is a discussion of the supersonic nonlinear point design optimization efforts at McDonnell Douglas Aerospace under the High-Speed Research (HSR) program. The baseline for these optimization efforts has been the M2.4-7A configuration which represents an arrow-wing technology for the High-Speed Civil Transport (HSCT). Optimization work on this configuration began in early 1994 and continued into 1996. Initial work focused on optimization of the wing camber and twist on a wing/body configuration and reductions of 3.5 drag counts (Euler) were realized. The next phase of the optimization effort included fuselage camber along with the wing and a drag reduction of 5.0 counts was achieved. Including the effects of the nacelles and diverters into the optimization problem became the next focus where a reduction of 6.6 counts (Euler W/B/N/D) was eventually realized. The final two phases of the effort included a large set of constraints designed to make the final optimized configuration more realistic and they were successful albeit with a loss of performance.

Unger, Eric R.; Hager, James O.; Agrawal, Shreekant

1999-01-01

92

Next-generation concurrent engineering: developing models to complement point designs  

Science.gov (United States)

Concurrent Engineering Design teams have made routine the rapid development of point designs for space missions. The Jet Propulsion Laboratory's Team X is now evolving into a next generation CED; nin addition to a point design, the team develops a model of the local trade space. The process is a balance between the power of model-developing tools and the creativity of human experts, enabling the development of a variety of trade models for any space mission.

Morse, Elizabeth; Leavens, Tracy; Cohanim, Barbak; Harmon, Corey; Mahr, Eric; Lewis, Brian

2006-01-01

93

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

94

OGAMA (Open Gaze and Mouse Analyzer): open-source software designed to analyze eye and mouse movements in slideshow study designs.  

Science.gov (United States)

In the present article, a new software is introduced that allows the recording and analyzing of eye- and mouse-tracking data from slideshow-based experiments in parallel. The Open Gaze and Mouse Analyzer (OGAMA) is written in C#.NET and has been released as an open-source project. Its main features include slideshow design, the recording of gaze and mouse data, database-driven preprocessing and filtering of gaze and mouse data, the creation of attention maps, areas-of-interest definition, and replay. Eyetracking and/or presentation soft- and hardware recordings in ASCII format can be imported. Data output is provided that can be used directly with different statistical software packages. Because it is open source, one can easily adapt it to suit one's needs. PMID:19001407

Vosskühler, Adrian; Nordmeier, Volkhard; Kuchinke, Lars; Jacobs, Arthur M

2008-11-01

95

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2012-04-10

96

Status of the Laser Inertial Fusion Energy (LIFE) Hohlraum Point Design  

International Nuclear Information System (INIS)

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.

97

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

OpenAIRE

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...

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

2007-01-01

98

A new conformer design to expand the horizontal lid fissure in severely microphthalmic eyes.  

Science.gov (United States)

Effective treatment of severe microphthalmos requires early placement of conformers to increase the size of the conjunctival sac and to increase orbital dimensions. This process may be confounded by inadequate horizontal lid length and microblepharon. Lateral canthotomy can be used to facilitate early placement of serial conformers, but this procedure is often avoided due to frequent peripalpebral scarring and recurrent phimosis. Conformers currently in use do not separate the lateral lid margins enough to prevent such scarring after lateral canthotomy. We describe a child with severe microphthalmos and microblepharon in whom a novel conformer was used to prevent scarring following lateral canthotomy. Use of this conformer design may make lateral canthotomy a viable option to expand the horizontal lid fissure and facilitate early orbital expansion in patients with severe microphthalmos. PMID:18423343

Christiansen, Stephen P; Gess, Adam J; Fletcher, Gene A

2008-04-01

99

Does the Three-Point Rule Make Soccer More Exciting? Evidence from a Regression Discontinuity Design  

OpenAIRE

We examine whether the three-point rule—the increase in rewards for a win from two- to three points that FIFA adopted in 1995—makes Bundesliga games become more exciting. Using regression discontinuity design as the empirical strategy, we do not find evidence that the three-point rule makes games more decisive, increases the number of goals, or decreases goal differences. We only find some evidence that the three-point rule increases the second-half goals of losing first-half teams. Overa...

Lee, Yoong Hon; Parinduri, Rasyad

2013-01-01

100

What Is Dry Eye?  

Medline Plus

Full Text Available ... Teenagers Computer Usage Diabetes Diet & Nutrition Eye Injuries Eye Screening Guidelines Home Remedies for Simple Eye Problems Medical Marijuana for Glaucoma Pregnancy Preventing Eye ...

101

Using eye-tracking methodology in consumer science  

DEFF Research Database (Denmark)

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.

Bialkova, S.; Mueller Loose, Simone

102

Eye redness  

Science.gov (United States)

... This may result from dry air, too much sun, dust, something in the eye, allergies, infection, or injury. One common cause of a red eye is straining or coughing. This can lead to a bright red, dense bloody area on the white part ...

103

Design and performance considerations of cat's-eye retroreflectors for use in open-path Fourier-transform-infrared spectrometry.  

Science.gov (United States)

A ray-tracing analysis of cat's-eye retroreflectors for use in active open-path Fourier-transform-infrared (OP/FT-IR) spectrometry and the results of testing f/0.5 and f/1.75 cat's-eye retroreflectors built in our laboratory with a commercial active OP/FT-IR spectrometer are presented. The ray-tracing model is based on the optical characteristics of a commercial single-telescope monostatic OP/FT-IR spectrometer and explores trends in cat's-eye behavior in practical but rigorous field conditions encountered during transportable outdoor use. All mirrors modeled are paraboloids for which the focal ratios of the primary mirror are f/0.5, f/1.75, and f/3. The effect of the focal ratio of the primary mirror, the focal length of the secondary mirror, and the off-axis alignment of the primary and the secondary mirror have been evaluated as a function of path length, including variable input-beam divergence, between the spectrometer and the cat's-eye. The paraboloidal mirrors comprising the primary and secondary of the cat's-eye retroreflectors tested were made in our laboratory by spin casting liquid epoxy-graphite composite mixtures followed by in situ polymerization with no postpolishing. PMID:12396182

Richardson, Robert L; Griffiths, Peter R

2002-10-20

104

Fuzzy Controller Design Using FPGA for Photovoltaic Maximum Power Point Tracking  

OpenAIRE

The cell has optimum operating point to be able to get maximum power. To obtain Maximum Power from photovoltaic array, photovoltaic power system usually requires Maximum Power Point Tracking (MPPT) controller. This paper provides a small power photovoltaic control system based on fuzzy control with FPGA technology design and implementation for MPPT. The system composed of photovoltaic module, buck converter and the fuzzy logic controller implemented on FPGA for controlling on/off time of MOSF...

Hamed, Basil M.; El-moghany, Mohammed S.

2012-01-01

105

Smoking and Eye Health  

Science.gov (United States)

... Sun Eye Health News Consumer Alerts Smoking and Eye Health Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During ... and Eye Protection Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Opening Champagne Bottles ...

106

Principles for the design and calibration of radiation protection dosemeters for operational and protection quantities for eye lens dosimetry  

International Nuclear Information System (INIS)

The work package two of the ORAMED project-Collaborative Project (2008-2011) supported by the European Commission within its seventh Framework Programme-is devoted to the study of the eye lens dosimetry. A first approach is to implement the use of Hp(3) by providing new sets of conversion coefficients and well suited calibration and type test procedures. This approach is presented in other papers in the proceedings of this conference. Taking into account that the eye lens is an organ close to the surface of the body, another approach would be to directly estimate the absorbed dose to the eye lens, Dlens,est through a special calibration procedure although this quantity is not directly measurable. This paper is a methodological paper that tries to identify the critical aspects of a dosimetry in terms of Dlens. (authors)

107

Your Eyes  

Science.gov (United States)

... inside your eye! Try looking away from your computer and focusing on something way across the room. ... steps to protect them: Wear protective goggles in classes where debris or chemicals could go flying, such ...

108

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

OpenAIRE

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 ...

Atul Bhardwaj; Lalita Agrawal; Anil Kumar Maini

2013-01-01

109

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 ...

110

LASIK - Laser Eye Surgery  

Medline Plus

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

111

What Is Dry Eye?  

Medline Plus

Full Text Available ... Eyes & the Sun Eye Health News Consumer Alerts What Is Dry Eye? Tweet When you blink, a ... tear film, good vision would not be possible. What Is Dry Eye? Causes of Dry Eye Dry ...

112

Eye Injuries at Home  

Science.gov (United States)

... What Is an Ophthalmologist? Your Eyes & the Sun Eye Health News Consumer Alerts Eye Injuries at Home Tweet ... Get eye MD-reviewed tips and information about eye health and preserving your vision. Privacy Policy Email address ...

113

Amblyopia: Lazy Eye Treatment  

Science.gov (United States)

... What Is an Ophthalmologist? Your Eyes & the Sun Eye Health News Consumer Alerts Amblyopia: Lazy Eye Treatment Tweet ... Get eye MD-reviewed tips and information about eye health and preserving your vision. Privacy Policy Email address © ...

114

Eye Injuries at Work  

Science.gov (United States)

... What Is an Ophthalmologist? Your Eyes & the Sun Eye Health News Consumer Alerts Eye Injuries at Work Tweet ... Get eye MD-reviewed tips and information about eye health and preserving your vision. Privacy Policy Email address ...

115

Preventing Eye Injuries  

Science.gov (United States)

... What Is an Ophthalmologist? Your Eyes & the Sun Eye Health News Consumer Alerts Preventing Eye Injuries Tweet Protecting ... Get eye MD-reviewed tips and information about eye health and preserving your vision. Privacy Policy Email address ...

116

Amblyopia: Lazy Eye Diagnosis  

Science.gov (United States)

... What Is an Ophthalmologist? Your Eyes & the Sun Eye Health News Consumer Alerts Amblyopia: Lazy Eye Diagnosis Tweet ... Get eye MD-reviewed tips and information about eye health and preserving your vision. Privacy Policy Email address © ...

117

What Is Dry Eye?  

Medline Plus

Full Text Available ... What Is an Ophthalmologist? Your Eyes & the Sun Eye Health News Consumer Alerts What Is Dry Eye? Tweet ... Get eye MD-reviewed tips and information about eye health and preserving your vision. Privacy Policy Email address © ...

118

Amblyopia: Lazy Eye Symptoms  

Science.gov (United States)

... What Is an Ophthalmologist? Your Eyes & the Sun Eye Health News Consumer Alerts Amblyopia: Lazy Eye Symptoms Tweet ... Get eye MD-reviewed tips and information about eye health and preserving your vision. Privacy Policy Email address © ...

119

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

Directory of Open Access Journals (Sweden)

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.

Siva K. Palaniappan

2007-01-01

120

An Examination of the Starting Point Approach to Design and Technology  

Science.gov (United States)

This study examines the Starting Point Approach (SPA) to design and technology, which is intended to maximize creativity while being manageable for the teacher. The purpose of the study was to examine whether the children could do what the approach requires and in particular whether it promoted their innovative thinking. Data were collected during…

Good, Keith; Jarvinen, Esa-Matti

2007-01-01

121

Design and development of a solar array drive. [a direct drive solar array pointing mechanism  

Science.gov (United States)

The design and development of a dry lubricated direct drive solar array pointing mechanism is discussed for use on the Orbital Test Satellite (OTS), MAROTS, European Communication Satellite (ECS), and others. Results of life testing the original prototype and the OTS mechanism are presented together with an appraisal of expected future development.

Rees, T.; Standing, J. M.

1977-01-01

122

Design and Principles of Linear Accelerators and Colliders: Focusing at Interaction Point  

CERN Document Server

This document is part of Subvolume C 'Accelerators and Colliders' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the the Section '7.7 Focusing at Interaction Point' of the Chapter '7 Design and Principles of Linear Accelerators and Colliders'.

Seryi, A

2013-01-01

123

Weighted least-square design of freeform lens for multiple point sources  

Science.gov (United States)

Freeform lenses can be designed for diverse illumination profiles with good uniformity. However, most of the previous studies were formulated for a single point source and the lens were designed to have a spherical bottom. In this study, the formulation is extended for multiple point sources and for lenses with a flat bottom in favor of prototyping and manufacturing. The extended formulation requires only a freeform surface to design. However, it could be over determined if the light rays emitted from the multiple point sources overlap at the near field. The weighted least-square method is introduced to solve the over-determined problem. A weighting function correlated with the emitting intensities of the sources is proposed to design for illumination profile fit and uniformity in trade-off. The adequacy of the extended formulation is demonstrated by simulation. Circular and rectangular illuminations of multiple point sources in different layouts are illustrated. The simulation results show that profile fit and uniformity could be significantly affected by a source offset. With the offset taken into account in the extended formulation, the effects can be properly collimated.

Lin, Ku Chin

2012-04-01

124

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)

125

Fuzzy Controller Design Using FPGA for Photovoltaic Maximum Power Point Tracking  

Directory of Open Access Journals (Sweden)

Full Text Available The cell has optimum operating point to be able to get maximum power. To obtain Maximum Power from photovoltaic array, photovoltaic power system usually requires Maximum Power Point Tracking (MPPT controller. This paper provides a small power photovoltaic control system based on fuzzy control with FPGA technology design and implementation for MPPT. The system composed of photovoltaic module, buck converter and the fuzzy logic controller implemented on FPGA for controlling on/off time of MOSFET switch of a buck converter. The proposed maximum power point tracking controller for photovoltaic system is tested using model designed by Matlab/Simulink program with graphical user interface (GUI for entering the parameters of any array model using information from its datasheet, Simulation and experimental results show that performance of the fuzzy controller with FPGA in a maximum power tracking of a photovoltaic array can be made use of in several photovoltaic products and obtain satisfied result.

Basil M Hamed

2012-06-01

126

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

127

Design status of ITER visible/IR outer strike point view  

International Nuclear Information System (INIS)

For ITER visible/IR imaging of the outer strike point from the six upper ports currently assigned, we show an optical design that provides a 4 mm Airy disk at 5 ?m wavelength at the farthest point in the field of view (much smaller in the visible), with as complete toroidal coverage of the vertical target as possible. Plasma and optical effects provide fundamental limits on the performance and design of the system. Some effects involve interactions of the surfaces with the plasma, such as plasma transport and deposition of material on the surfaces to be viewed, plasma damage to those surfaces, and molecular emission by the plasma at IR wavelengths. We discuss a detailed optical design including the endoscope concept, entrance aperture and collection head, relay optics, and camera specifications and performance. We assess integration times for capture of IR emission from surfaces and visible line emission predicted by boundary modeling.

128

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

International Nuclear Information System (INIS)

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

129

An eye for inspiration  

Science.gov (United States)

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.

2009-11-01

130

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 Opening Champagne Bottles ...

131

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’ ...

132

What Is Dry Eye?  

Medline Plus

Full Text Available ... M.D.-approved information from EyeSmart Dry Eye Treatment - Eye M.D.-approved information from EyeSmart Related Answers Is dry eye causing my severe eye pain? Can Vectibix (a drug used to treat cancer) cause keratitis of the eye? Is there a ...

133

LASIK - Laser Eye Surgery  

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Full Text Available Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During Pregnancy Computer Usage & Eye Strain Maintaining Your Sight ... and Eye Protection Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Opening Champagne Bottles ...

134

At-sea test system point design for a one-third scale cold water pipe  

Energy Technology Data Exchange (ETDEWEB)

One step in the development of the technology for Ocean Thermal Energy Conversion (OTEC) Cold Water Pipes (CWP) is the at-sea testing of a fiberglass reinforced plastic nominal 10-foot diameter pipe. A design procedure and criteria for developing test hardware by scaling down a 30-foot diameter OTEC 10/40 MW Pilot Plant CWP design are presented. An example point design for the pipe, instrumentation to be used during the at-sea tests, and methods for selecting the support platform and mooring are described. The design considered starts with a scale model of a larger prototype, and then is modified to address the problems of fabrication and of survivability and handling during the 1/3rd scale model tests.

Sutherland, W.H. (ed.)

1979-12-01

135

Googly Eyes  

Science.gov (United States)

Beverage take-out trays are funky in their form and function. In this article, the author describes how to make googly eye masks out of discarded take-out trays and other common recycled or discarded materials. (Contains 1 online resource.)

Boss, Susan

2009-01-01

136

Design, Construction, and Evaluation of Ni-C Eutectic Fixed Points  

Science.gov (United States)

In this article the design, construction, and evaluation of eutectic fixed points for contact and non-contact measurements that have been recently developed at MIRS/UL/FE-LMK are presented. The design of the cells is made in such way that it can be used for only thermocouple calibration in vertical or horizontal furnaces, for calibration of pyrometers in a horizontal furnace, and for simultaneous calibration of contact and non-contact thermometers in a horizontal furnace. Special care has been taken to achieve repeatability and reproducibility of the transition temperatures and mechanical robustness of the cell. This includes also usage of a carbon sleeve in combination with carbon sheets, in a so-called hybrid design of the eutectic cell. With such a design, significant improvement in mechanical robustness of the cell and temperature stability of the cell has been achieved. All the measurements are performed within specially designed seven-zone furnaces within which different gradients, and different heating and cooling rates can be realized. The melting temperature of Ni-C ((1328.44 ± 0.70) °C) measured with a thermocouple type R, calibrated at the zinc, aluminum, silver, copper, and palladium fixed points, and a non-contact thermometer, calibrated by comparison against different blackbodies, agree within their expanded uncertainties of 0.7 °C and 1.5 °C, respectively.

Bojkovski, J.; Hiti, M.; Batagelj, V.; Drnovšek, J.

2011-08-01

137

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

CERN Document Server

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.

Yang, Min; 10.1214/07-AOS560

2009-01-01

138

Design and Simulation of PV System with Incremental Conductance Method for Maximum Power Point Tracking  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a complete design and simulation of a Photovoltaic System (PVS with capable of Maximum Power Point Tracking (MPPT.In this paper Incremental Conductance Method (ICM is adopted for the MPPT technique. The proposed PV System is modelled and simulated in MATLAB/Simulink GUI environment. Finally, dynamic performance of the proposed PV System with ICM is presented to demonstrate its capability of MPPT, which has a better tracking performance.

Uma Maheswara Rao Ch., Bala Murali Krishna V., A. Srihari Babu, Suman S.

2014-05-01

139

Conditions for perfect focusing multiple point sources with the SMS design method  

Science.gov (United States)

In this work, we demonstrate how it is possible to sharply image multiple object points. The Simultaneous Multiple Surface (SMS) design method has usually been presented as a method to couple N wave-front pairs with N surfaces, but recent findings show that when using N surfaces, we can obtain M image points when Nstop. In the process of maximizing the object points to sharp image, we try to exhaust the degrees of freedom of aspherics and free-forms. We conjecture that maximal SMS designs are very close to a good solution, hence using them as a starting point for the optimization will lead us faster to a final optical system. We suggest here different optimization strategies which combined with the SMS method are proven to give the best solution. Through the example of imaging with the high aspect ratio, we compare the results obtained optimizing the rotational lens and using a combination of SMS method and optimization, showing that the second approach is giving significantly smaller value of overall RMS spot diameter.

Benítez, P.; Miñano, Juan C.; Nikolic, Milena; Liu, Jiayao; Infante, Jose; Duerr, Fabian

2014-09-01

140

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

Directory of Open Access Journals (Sweden)

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.

M. Radhika Mani

2014-12-01

141

Childhood Eye Diseases and Conditions  

Science.gov (United States)

... Consumer Alerts Childhood Eye Diseases and Conditions Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During ... and Eye Protection Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Opening Champagne Bottles ...

142

Genetic Testing and Eye Disease  

Science.gov (United States)

... In Focus: Genetic Testing and Eye Disease Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During ... and Eye Protection Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Opening Champagne Bottles ...

143

Eye muscle repair - discharge  

Science.gov (United States)

... Lazy eye repair - discharge; Strabismus repair - discharge; Extraocular muscle surgery - discharge ... You or your child had eye muscle repair surgery to correct eye ... term for crossed eyes is strabismus. Children usually receive ...

144

What Is Dry Eye?  

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145

LASIK - Laser Eye Surgery  

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

146

LASIK - Laser Eye Surgery  

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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 ...

147

What Is Dry Eye?  

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Full Text Available ... Marijuana for Glaucoma Pregnancy Preventing Eye Injuries Smokers Sports Using Eye Makeup Veterans What Is an Ophthalmologist? ... Related Resources Related Topics Six Smart Things College Students Should Do For Their Eyes - Eye M.D.- ...

148

Diabetic Eye Disease  

Science.gov (United States)

... the Clinical Director Education Programs All Education National Eye Health Education Program Diabetic Eye Disease Education Program Glaucoma ... see Common vision problems Age-Related Eye Diseases Eye Health Tips Podcasts Text Messages Vision-Related Terms, Selected ...

149

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 ...

150

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

Science.gov (United States)

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.

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

151

A Note on Eye Movement  

CERN Document Server

In a simplified fashion, the motion of the eyeball in its orbit consists of rotations around a fixed point. Therefore, this motion can be described in terms of the Euler's angles of rigid body dynamics. However, there is a physiological constraint in the motion of the eye which reduces to two its degrees of freedom. This paper reviews the basic features of the kinematics of the eye and the laws governing its motion.

Bolina, O; Bolina, Oscar

1998-01-01

152

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... Healthy Eyes During Pregnancy Computer 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’t Mix To help prevent eye infections, ...

153

What Is Dry Eye?  

Medline Plus

Full Text Available ... M.D.-approved information from EyeSmart Dry Eye Treatment - Eye M.D.-approved information from EyeSmart Related Answers Is dry eye causing my severe eye pain? Can Vectibix (a drug used to treat cancer) cause keratitis of the ...

154

What Is Dry Eye?  

Medline Plus

Full Text Available ... Eyes - Eye M.D.-approved information from EyeSmart Travel Tips For Your Eyes Only - Eye M.D.- ... about eye health and preserving your vision. Privacy Policy Email address © 2015 American Academy of Ophthalmology medical ...

155

Point Selection for Triangular 2-D Mesh Design Using Adaptive Forward Tracking Algorithm  

Directory of Open Access Journals (Sweden)

Full Text Available Two-dimensional mesh-based motion tracking preserves neighboring relations (through connectivity of the mesh and also allows warping transformations between pairs of frames; thus, it effectively eliminates blocking artifacts that are common in motion compensation by block matching. However, available uniform 2-D mesh model enforces connec-tivity everywhere within a frame, which is clearly not suitable across occlusion boundaries. To overcome this limitation, BTBC (background to be covered detection and MF (model failure detection algorithms are being used. In this algorithm, connectivity of the mesh elements (patches across covered and uncovered region boundaries are broken. This is achieved by allowing no node points within the background to be covered and refining the mesh structure within the model failure region at each frame. We modify the occlusion-adaptive, content-based mesh design and forward tracking algorithm used by Yucel Altunbasak for selection of points for triangular 2-D mesh design. Then, we propose a new triangulation procedure for mesh structure and also a new algorithm to justify connectivity of mesh structure after motion vector estimation of the mesh points. The modified content-based mesh is adaptive which eliminates the necessity of transmission of all node locations at each frame.

Nastaran Borjian

2011-02-01

156

Design and Implementation of Floating Point Multiplier for Better Timing Performance  

Directory of Open Access Journals (Sweden)

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.

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

2012-09-01

157

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

Science.gov (United States)

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.

Scriber, Michael W.

1989-12-01

158

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

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...

Zierer, Klaus; Seel, Norbert M.

2012-01-01

159

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

160

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

Science.gov (United States)

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.

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

2014-10-01

161

Design Heuristics for Mapping Floating-Point Scientific Computational Kernels onto High Performance Reconfigurable Computers  

Directory of Open Access Journals (Sweden)

Full Text Available Because of the increasing need to develop efficient high-speed computational kernels, researchers have been looking at various acceleration technologies. One approach is to use field programmable gate arrays (FPGAs in conjunction with general purpose processors to form what are known as high performance reconfigurable computers (HPRCs. HPRCs have already been shown to work well for both fixed-point and integer calculations. Floating-point calculations are a different matter; obtaining speedups has been somewhat elusive. This article, after introducing the three primary HPRC development flows, takes a detailed look at “the three p’s,” which addresses the crucial relationship among performance, pipelining, and parallelism. It also examines “the FPGA design boundary,” which addresses some of the heuristics that allow developers to determine which application modules can be mapped onto the FPGAs. These ideas are illustrated by way of a simple floating-point application that is mapped onto a contemporary HPRC. This article expands upon earlier work by including details on how to map customized intellectual property cores into an HPRC environment via a hybrid development flow.

Justin L. Rice

2009-06-01

162

The Chandra Cygnus OB2 Legacy Survey: Design and X-ray Point Source Catalog  

CERN Document Server

The Cygnus OB2 association is the largest concentration of young and massive stars within 2 kpc of the Sun, including an estimated 65 O-type stars and hundreds of OB stars. The Chandra Cygnus OB2 Legacy Survey is a large imaging program undertaken with the Advanced CCD Imaging Spectrometer onboard the Chandra X-ray Observatory. The survey has imaged the central 0.5 deg^2 of the Cyg OB2 association with an effective exposure of 120ks and an outer 0.35 deg^2 area with an exposure of 60ks. Here we describe the survey design and observations, the data reduction and source detection, and present a catalog of 8,000 X-ray point sources. The survey design employs a grid of 36 heavily (~50%) overlapping pointings, a method that overcomes Chandra's low off-axis sensitivity and produces a highly uniform exposure over the inner 0.5 deg^2. The full X-ray catalog is described here and is made available online.

Wright, Nicholas J; Guarcello, Mario G; Aldcroft, Tom L; Kashyap, Vinay L; Damiani, Francesco; DePasquale, Joe; Fruscione, Antonella

2014-01-01

163

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)

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

Atul Bhardwaj

2013-12-01

164

Simulation of eye-safe imaging laser radar for advanced range estimation and improved design process using VRML  

Science.gov (United States)

Eye-safe laser radar systems based on gated viewing use narrow infrared laser pulses to illuminate a whole scene for direct (incoherent) detection. Due to the time of flight principle and a very fast shutter with precisely controlled delay time, only light reflected in a certain range slice is detected. Due to the lack of off-shelf components, the development of such systems is difficult. Also, comparison of different systems is complicated, since atmospheric transmission, target reflectivity, polarization, and different noise effects have great influence on the system performance. The laser radar equation is used to estimate range performance in a a general manner. In this paper we discuss improvements in the system modelling of our laser radar system. Pixel wise simulation in combination with three dimensional scenes, generated with Virtual Reality Markup Language (VRML) is used to generate realistic range images. Changing to a pixel oriented approach and three dimensional modelled scenes, we are now able to study the system response for targets with arbitrary form and even different reflectivity. Also, we take into account the gaussian nature of the illuminating laser spot and different noise sources. Hence it is possible to simulate gray value images and calculate range images.

Schael, Ulrich; Rothe, Hendrik

2003-10-01

165

What Is Dry Eye?  

Medline Plus

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166

Diabetes - Eye Complications  

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Full Text Available Diabetes - Eye Complications Introduction Patients with diabetes are more likely to have eye problems that can lead to blindness. Many of ... these eye problems from happening. How The Eye Works? Light first hits the cornea of the eye, ...

167

Diabetes - Eye Complications  

Medline Plus

Full Text Available ... eye problems from happening. How The Eye Works? Light first hits the cornea of the eye, which allows light to enter the eye through the pupil. The iris controls the amount of light that enters the eye by changing the size ...

168

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

DEFF Research Database (Denmark)

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.

Maheshwari, Ram Krishan; Munk-Nielsen, Stig

2013-01-01

169

Mixed-flow vertical tubular hydraulic turbine. Determination of proper design duty point  

Energy Technology Data Exchange (ETDEWEB)

A new vertical single-regulated mixed-flow turbine with conical guide apparatus and without spiral casing is presented in this paper. Runner blades are fixed to the hub and runner band and resemble to the Francis type runner of extremely high specific speed. Due to lack of information and guidelines for the design of a new turbine, a theoretical model was developed in order to determinate the design duty point, i.e. to determine the optimum narrow operation range of the turbine. It is not necessary to know the kinematic conditions at the runner inlet, but only general information on the geometry of turbine flow-passage, meridional contour of the runner and blading, the number of blades and the turbine speed of rotation. The model is based on the integral tangential lift coefficient, which is the average value over the entire runner blading. The results are calculated for the lift coefficient 0.5 and 0.6, for the flow coefficient range from 0.2 to 0.36, for the number of the blades between 5 and 13, and are finally presented in the Cordier diagram (specific speed vs. specific diameter). Calculated results of the turbine optimum operation in Cordier diagram correspond very well to the adequate area of Kaplan turbines with medium and low specific speed and extends into the area of Francis turbines with high specific speed. Presented model clearly highlights the parameters that affect specific load of the runner blade row and therefore the optimum turbine operation (discharge - turbine head). The presented method is not limited to a specific reaction type of the hydraulic turbine. The method can therefore be applied to a wide range from mixed-flow (radial-axial) turbines to the axial turbines. Applicability of the method may be considered as a tool in the first stage of the turbine design i.e. when designing the meridional geometry and selecting the number of blades according to calculated operating point. Geometric and energy parameters are generally defined to an extent that these parameters are considered in detailed design using turbulent viscous flow CFD solver. (orig.)

Sirok, B. [Ljubljana Univ. (Slovenia). Faculty of Mechanical Engineering; Bergant, A. [Litostroj Power, d.o.o., Ljubljana (Slovenia); Hoefler, E.

2011-12-15

170

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

Directory of Open Access Journals (Sweden)

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.

Stephen Ashton

2011-01-01

171

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... have LASIK, it is important to keep a record of your pre-operation and post-operation eye ... eye MD-reviewed tips and information about eye health and preserving your vision. Privacy Policy Email address

172

What Is Dry Eye?  

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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 ...

173

What Is Dry Eye?  

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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 ...

174

Diabetes - Eye Complications  

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Full Text Available Diabetes - Eye Complications Introduction Patients with diabetes are more likely to have eye problems that can lead to blindness. Many of these eye diseases can be prevented or delayed ...

175

LASIK - Laser Eye Surgery  

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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 ...

176

What Is Dry Eye?  

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Full Text Available ... Eyelid Lump Feel Something in Eye Flashes of Light Irritation Itchiness Light Sensitivity Red Eye Reduced Vision Tearing See all ... Dry Eye Written by Kierstan Boyd Reviewed by Dr. Devin Harrison on March 1, 2014 Search for ...

177

Imaging of the whole anterior eye segment with full-range complex spectral domain optical coherence tomography  

Science.gov (United States)

We demonstrate the capability of spectral domain optical coherence tomography (SD-OCT) with a full range complex (FRC) technique to image the anterior eye segment from the cornea to the back surface of the lens. We improved the spectrometer resolution with an adapted spectrometer design to achieve a single depth range of 7 mm in air. This depth range was doubled to an imaging range of 14 mm with a FRC-technique based on phase modulation introduced by off pivot point illumination of the galvanometer scanner. The performance of our system is demonstrated by recorded 2D and 3D datasets of the whole anterior eye segment of healthy human eyes in vivo. The system is also applicable to demonstrate the changes of the anterior eye segment during the accommodation of the eye.

Jungwirth, Johannes; Baumann, Bernhard; Pircher, Michael; Götzinger, Erich; Hitzenberger, Christoph K.

2009-07-01

178

What Is Dry Eye?  

Science.gov (United States)

... Eye) Astigmatism Bacterial Keratitis Bell's Palsy Blepharitis Cataracts Contact Lens-Related Infections Detached & Torn Retina Diabetic Retinopathy Dry Eye Floaters & Flashes Glaucoma Hyperopia (Farsightedness) Low Vision ...

179

Eye muscle repair - series (image)  

Science.gov (United States)

... the eyeball to the eye socket. The external muscles of the eye are found behind the conjunctiva. ... The extraocular muscles of the eye (external to the eyeball) control the positioning of the eyes. They coordinate of the eye ...

180

Conjunctivitis: What Is Pink Eye?  

Science.gov (United States)

... What Is an Ophthalmologist? Your Eyes & the Sun Eye Health News Consumer Alerts Conjunctivitis: What Is Pink Eye? ... Get eye MD-reviewed tips and information about eye health and preserving your vision. Privacy Policy Email address © ...

181

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

182

Get Your Eyes Tested  

Science.gov (United States)

... the difference between a vision screening and an eye exam? A vision screening is a short checkup for your eyes. It ... screenings can only find certain eye problems. An eye exam takes more time than a vision screening, and it’s the only way to find some ...

183

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... correcting vision with surgery rather than eyeglasses or contact lenses. Next 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 ... eye MD-reviewed tips and information about eye health and preserving your vision. Privacy Policy Email address

184

Healthy Eyes, Healthy Body  

Science.gov (United States)

... and physical activity affect their health – including their eye health. Find out all about eye health at www.GetEyeSmart.org. Special Thanks for this ... resource to find out how to improve your eye health at all stages of life. 1 Introduction Know ...

185

Robustifying eye interaction  

DEFF Research Database (Denmark)

This paper presents a gaze typing system based on consumer hardware. Eye tracking based on consumer hardware is subject to several unknown factors. We propose methods using robust statistical principles to accommodate uncertainties in image data as well as in gaze estimates to improve accuracy. We have succeeded to track the gaze of people with a standard consumer camera, obtaining accuracies about 160 pixels on screen. Proper design of the typing interface, however, reduces the need for high accuracy. We have observed typing speeds in the range of 3 - 5 words per minute for untrained subjects using large on-screen buttons and a new noise tolerant dwell-time principle

Hansen, Dan Witzner; Hansen, John Paulin

2006-01-01

186

Biomimetic microfabricated compound eyes  

Science.gov (United States)

Over the past century, compound eyes in nature have been one of the most studied and intriguing topics in physiological optics due to their unique optical scheme for imaging. Hundreds to ten thousands of integrated optical units called ommatidia are spherically arranged along a curvilinear surface and point in different directions. Each ommatidium collects light within a small angular acceptance and collectively they construct a full image with a wide field-of-view. In this work, artificial compound eye lenses with three-dimensional configuration, which are anatomically and functionally similar to those in nature, have been synthesized using a photosensitive polymer resin by utilizing microlens technology, self-written waveguide process, and soft lithography. Replicated honeycomb packed polymer microlenses as substitute for facet lenses in a natural compound eye was microfabricated with a photoresist melting process for microlens templates and a soft lithographic process for polymer replication. The microtemplate of photoresist microlens arrays (F/1 ˜ F/3, DL = 20 ˜ 50 mum) with low Fresnel number (NF waveguide, and the angular acceptance function of a microlens-waveguide system were theoretically studied with numerical analysis. First, as a prototype microfabricated microlens-waveguide system ( DL = 300 mum), a small angular acceptance (rho A = 1.5°) comparable to that of natural ommatidia was experimentally achieved and compared with the numerical analysis. The system is based on self-written waveguides in a photosensitive polymer resin and replicated elastomer microlens arrays. However, due to the technical difficulties in handling the elastomer membrane with microlenses, it is limited in scaling down to the physical dimensions of natural ommatidium. Second, as an advanced development, self-aligned microlens-waveguide systems comparable to the physical dimensions of natural ommatidia have been developed and integrated in a photosensitive resin. The individual microlens-waveguide systems of about 8,370 were spherically arranged along the circumference of a polymer dome of 2.5 mm in diameter and each points in different directions. The spherical configuration was realized using a replication process of reconfigurable microtemplates, i.e. the polymer replication using the deformed elastomer membrane with microlens patterns under small pressure (5 kPa ˜ 20 kPa). The characterizations of the small scale microlenses (F/1.8 ˜ F/2.9, DL = 25 mum) and waveguides were also carried out with a modified reflection/transmission confocal microscope. The comparative discussion between natural and artificial compound eyes is described and several future directions based on this work are also proposed.

Jeong, Ki-Hun

2005-11-01

187

NGNP Point Design - Results of the Initial Neutronics and Thermal-Hydraulic Assessments During FY-03, Rev. 1  

Energy Technology Data Exchange (ETDEWEB)

This report presents the preliminary preconceptual designs for two possible versions of the Next Generation Nuclear Plant (NGNP), one for a prismatic fuel type helium gas-cooled reactor and one for a pebble bed fuel helium gas reactor. Both designs are to meet three basic requirements: 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. The two efforts are discussed separately below. The analytical results presented in this report are very promising, however, we wish to caution the reader that future, more detailed, design work will be needed to provide final answers to a number of key questions including the allowable power level, the inlet temperature, the power density, the optimum fuel form, and others. The point design work presented in this report provides a starting point for other evaluations, and directions for the detailed design, but not final answers.

Philip E. MacDonald; James W. Sterbentz; Robert L. Sant; P. Bayless; H. D. Gougar; R. L. Moore; A. M. Ougouag; W. K. Terry

2003-09-01

188

Phase-equilibria for design of coal-gasification processes: dew points of hot gases containing condensible tars. Final report  

Energy Technology Data Exchange (ETDEWEB)

This research is concerned with the fundamental physical chemistry and thermodynamics of condensation of tars (dew points) from the vapor phase at advanced temperatures and pressures. Fundamental quantitative understanding of dew points is important for rational design of heat exchangers to recover sensible heat from hot, tar-containing gases that are produced in coal gasification. This report includes essentially six contributions toward establishing the desired understanding: (1) Characterization of Coal Tars for Dew-Point Calculations; (2) Fugacity Coefficients for Dew-Point Calculations in Coal-Gasification Process Design; (3) Vapor Pressures of High-Molecular-Weight Hydrocarbons; (4) Estimation of Vapor Pressures of High-Boiling Fractions in Liquefied Fossil Fuels Containing Heteroatoms Nitrogen or Sulfur; and (5) Vapor Pressures of Heavy Liquid Hydrocarbons by a Group-Contribution Method.

Prausnitz, J.M.

1980-05-01

189

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)

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

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

2012-01-01

190

Eye injuries and the dentist.  

Science.gov (United States)

The risk of damage to the eyes of the patient, the dentist and his assistant should be recognized. Protection can be achieved by the wearing of specially designed spectacles using CR 39 plastic tinted lenses. Contact lenses should be removed by patients who are to undergo general anaesthesia. PMID:285665

Colvin, J

1978-12-01

191

The status and development prospects of cooling tower design from the point of view of various environmental effects  

International Nuclear Information System (INIS)

The manufacturers of wet and dry cooling towers are striving to develop plants for discharging waste heat into the atmosphere which are as operationally safe and favourable from the environmental point of view as possible. Using as an example plants which have been tendered and designed for water cooling, the paper indicates how the cooling tower design can be adapted to suit the particular environmental protection requirements of the location. (orig.)

192

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

Science.gov (United States)

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.

Smagala, Tom; Mcglew, Dave

1988-01-01

193

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)

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.

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

2014-06-01

194

Demands on Shape Memory Alloys from the Application Designer's Point of View  

OpenAIRE

In order to improve the conditions for utilization of Shape Memory Alloys (SMAs) in engineering design, the engineering design process and the shape memory effect have been studied from the viewpoint of the engineering designer. Further, the maturity of the SMA technology has been evaluated according to a common evaluation technique denoted the technology readiness assessment. The results obtained in this paper confirm that SMAs introduce unacceptable uncertainties in the engineering design p...

Abrahamsson, P.; Møster, E.

1997-01-01

195

What Is Dry Eye?  

Medline Plus

Full Text Available ... Degeneration (AMD) Allergies Amblyopia (Lazy Eye) Astigmatism Bacterial Keratitis Bell's Palsy Blepharitis Cataracts Contact Lens-Related Infections ... Vectibix (a drug used to treat cancer) cause keratitis of the eye? Is there a generic drug ...

196

Diabetes - Eye Complications  

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Full Text Available ... diabetes helps prevent and delay these eye diseases. Management of diabetes consists of the following: ... and other eye diseases. This document is for informational purposes and is not intended ...

197

What Is Dry Eye?  

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Full Text Available ... Eye) Astigmatism Bacterial Keratitis Bell's Palsy Blepharitis Cataracts Contact Lens-Related Infections Detached & Torn Retina Diabetic Retinopathy Dry Eye Floaters & Flashes Glaucoma Hyperopia (Farsightedness) Low Vision ...

198

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; ...

199

LASIK - Laser Eye Surgery  

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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 > ...

200

Diabetes - Eye Complications  

Medline Plus

Full Text Available ... How The Eye Works? Light first hits the cornea of the eye, which allows light to enter ... are essential for identifying early signs of retinopathy. Laser surgery is available to slow the development of proliferative ...

201

LASIK - Laser Eye Surgery  

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Full Text Available ... eye care provider for your condition or treatment. Are You Fit at 40? A baseline eye exam ... where it heals in place. For people who are nearsighted, LASIK is used to flatten a cornea ...

202

LASIK - Laser Eye Surgery  

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Full Text Available ... using either a blade or a laser. The surgeon folds back the flap and precisely removes a ... eye measurements is centered above the eye. The surgeon checks that the laser is positioned correctly. The ...

203

Diabetes - Eye Complications  

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Full Text Available ... eye doctors regularly. Ask your doctor for additional resources regarding diabetic retinopathy and other eye diseases. This ... your specific condition. ©1995-2012, The Patient Education Institute, Inc. www.X-Plain.com db010105 Last reviewed: ...

204

What Is Dry Eye?  

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Full Text Available ... of tears in response to eye irritation or emotion. When a foreign body or dryness irritates the ... pain? Can Vectibix (a drug used to treat cancer) cause keratitis of the eye? Is there a ...

205

LASIK - Laser Eye Surgery  

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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 ...

206

Strabismus (Crossed Eyes)  

Science.gov (United States)

... Z Listing Good Vision For Life Infants Children Adults Seniors Caring for Your Vision Eye & Vision Exams Contact Lenses Diet and Nutrition UV Protection Resources for Teachers 3D Vision & Eye Health Classroom Exercises ...

207

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... correcting vision with surgery rather than eyeglasses or contact lenses. Next Page: Alternative Refractive Surgery ... Newsletter Get eye MD-reviewed tips and information about eye health and preserving your vision. Privacy ...

208

What Is Dry Eye?  

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Full Text Available ... Ophthalmologists Adults Under 40 Adults 40 to 60 Adults Over 60 Babies, Children & Teenagers Computer Usage Diabetes Diet & Nutrition Eye Injuries Eye Screening Guidelines Home Remedies for ...

209

What Is Dry Eye?  

Medline Plus

Full Text Available ... 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 EyeWiki ...

210

LASIK - Laser Eye Surgery  

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Full Text Available ... eye — to improve the way the eye focuses light rays onto the retina at the back of ... correctly. The patient looks at a special pinpoint light, called a fixation or target light, while the ...

211

Functional Improvement After One- and Two-Eyed Cataract Surgery in the Salisbury Eye Evaluation  

Science.gov (United States)

Purpose To determine the impact cataract and cataract surgery have on clinical measurements of vision, reading speed, objective mobility performance, and subjective visual functioning. Design Prospective, population-based study Participants 1,739 Salisbury Eye Evaluation (SEE) participants without previous cataract surgery with bilateral baseline best corrected visual acuity (BCVA) of logarithm of the Minimum Angle of Resolution (logMAR) ? 0.3 (20/40 or better) or cataract surgery between round 1 and 2. Methods Participants were categorized based on cataract surgery by round 2 into: no surgery, unilateral surgery, or bilateral surgery. Visual performance, mobility-based tasks, and the Activities of Daily Vision Scale (ADVS) were measured at baseline and two years. Mobility score was converted into a z-score, by subtracting the participant’s time from the population baseline average then dividing by the standard deviation. Comparisons were made between the no surgery and surgery groups using multivariate linear regression. Main Outcome Measures Change in bilateral best corrected visual acuity in logMAR, contrast sensitivity, reading speed in words per minute (wpm), mobility score, and ADVS. Results During the study period, 29 participants had cataract surgery on both eyes, 90 had unilateral surgery, and 1,620 had none. After adjusting for baseline value, demographics, depression and mental status, the unilateral surgery group BCVA improved 0.04 logMAR (p=0.001) and the bilateral group improved 0.13 compared to no surgery (p<0.001). Overall mobility declined in all groups. The unilateral group z-score declined 0.18 more than the no surgery group (p=0.02), while the bilateral group showed a 0.18 z-score improvement compared to no surgery (p=0.19). Change in reading speed significantly improved in the unilateral and bilateral groups compared to no surgery (12 and 31 words per minute, respectively). The bilateral surgery group showed significant positive change in ADVS compared to no surgery (5 points relative improvement, p = 0.01), while the unilateral group showed a 5-point relative decline (p<0.001). Conclusions Cataract negatively affects both subjective quality of life and objective performance measures. Unilateral cataract surgery improves visual functioning, but the largest gains are found in patients who undergo second-eye cataract surgery. This finding supports second-eye cataract surgery for patients with visual or functional complaints even after successful first-eye surgery. PMID:23357620

Lee, Bryan S.; Munoz, Beatriz E.; West, Sheila K.; Gower, Emily W.

2012-01-01

212

The injured eye  

OpenAIRE

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...

Scott, Robert

2011-01-01

213

School eye health appraisal  

OpenAIRE

School children form an important large target group which must be screened adequately for early detection of eye diseases and prevention of blindness. A total approach in a school eye health programme must include teacher orientation and health education of children in addition to screening for eye diseases. The ocular morbidity pattern in 5135 school children of Jodhpur is discussed in this paper and it is hoped that it will be an indicator to all eye care agencies to help plan their priori...

Desai Sanjiv; Desai Rajiv; Desai N; Lohiya Shobha; Bhargava G; Kumar K.

1989-01-01

214

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 ... well-prepared and informed patient by reviewing the resources below before you have LASIK. If these materials ...

215

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 ( ... Presbyopia (Aging Eye) Stye Uveitis/Iritis See all Diseases & Conditions > Symptoms Blurriness Dark Curtain Dark Spots Discharge ...

216

Optimization of pupil design for point-scanning and line-scanning confocal microscopy  

OpenAIRE

Both point-scanning and line-scanning confocal microscopes provide resolution and optical sectioning to observe nuclear and cellular detail in human tissues, and are being translated for clinical applications. While traditional point-scanning is truly confocal and offers the best possible optical sectioning and resolution, line-scanning is partially confocal but may offer a relatively simpler and lower-cost alternative for more widespread dissemination into clinical settings. The loss of sect...

Patel, Yogesh G.; Rajadhyaksha, Milind; Dimarzio, Charles A.

2011-01-01

217

The ARIES-III D-3He tokamak reactor: Design-point determination and parametric studies  

International Nuclear Information System (INIS)

The multi-institutional ARIES study has generated a conceptual design of another tokamak fusion reactor in a series that varies the assumed advances in technology and physics. The ARIES-3 design uses a D-3He fuel cycle and requires advances in technology and physics for economical attractiveness. The optimal design was characterized through systems analyses for eventual conceptual engineering design. Results from the systems analysis are summarized, and a comparison with the high-field, D-T fueled ARIES-1 is included. 11 refs., 5 figs

218

MCNP-REN - A Monte Carlo Tool for Neutron Detector Design Without Using the Point Model  

International Nuclear Information System (INIS)

The development of neutron detectors makes extensive use of the predictions of detector response through the use of Monte Carlo techniques in conjunction with the point reactor model. Unfortunately, the point reactor model fails to accurately predict detector response in common applications. For this reason, the general Monte Carlo N-Particle code (MCNP) was modified to simulate the pulse streams that would be generated by a neutron detector and normally analyzed by a shift register. This modified code, MCNP - Random Exponentially Distributed Neutron Source (MCNP-REN), along with the Time Analysis Program (TAP) predict neutron detector response without using the point reactor model, making it unnecessary for the user to decide whether or not the assumptions of the point model are met for their application. MCNP-REN is capable of simulating standard neutron coincidence counting as well as neutron multiplicity counting. Measurements of MOX fresh fuel made using the Underwater Coincidence Counter (UWCC) as well as measurements of HEU reactor fuel using the active neutron Research Reactor Fuel Counter (RRFC) are compared with calculations. The method used in MCNP-REN is demonstrated to be fundamentally sound and shown to eliminate the need to use the point model for detector performance predictions

219

School eye health appraisal  

Directory of Open Access Journals (Sweden)

Full Text Available School children form an important large target group which must be screened adequately for early detection of eye diseases and prevention of blindness. A total approach in a school eye health programme must include teacher orientation and health education of children in addition to screening for eye diseases. The ocular morbidity pattern in 5135 school children of Jodhpur is discussed in this paper and it is hoped that it will be an indicator to all eye care agencies to help plan their priorities in the delivery of school based eye care.

Desai Sanjiv

1989-01-01

220

Poverty and Eye Health  

Directory of Open Access Journals (Sweden)

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.

Jyoti Jaggernath

2014-07-01

221

Thyroid Eye Disease: Protruding, Irritated Eyes  

Science.gov (United States)

... most common abnormalities are prominent eyes, a staring expression and infrequent blinking. What are the causes? Hyperthyroidism is a condition in which there is overproduction of thyroid hormones. Abnormal antibodies that attack the thyroid gland cause it ...

222

Optimization of pupil design for point-scanning and line-scanning confocal microscopy.  

Science.gov (United States)

Both point-scanning and line-scanning confocal microscopes provide resolution and optical sectioning to observe nuclear and cellular detail in human tissues, and are being translated for clinical applications. While traditional point-scanning is truly confocal and offers the best possible optical sectioning and resolution, line-scanning is partially confocal but may offer a relatively simpler and lower-cost alternative for more widespread dissemination into clinical settings. The loss of sectioning and loss of contrast due to scattering in tissue is more rapid and more severe with a line-scan than with a point-scan. However, the sectioning and contrast may be recovered with the use of a divided-pupil. Thus, as part of our efforts to translate confocal microscopy for detection of skin cancer, and to determine the best possible approach for clinical applications, we are now developing a quantitative understanding of imaging performance for a set of scanning and pupil conditions. We report a Fourier-analysis-based computational model of confocal microscopy for six configurations. The six configurations are point-scanning and line-scanning, with full-pupil, half-pupil and divided-pupils. The performance, in terms of on-axis irradiance (signal), resolution and sectioning capabilities, is quantified and compared among these six configurations. PMID:21833360

Patel, Yogesh G; Rajadhyaksha, Milind; Dimarzio, Charles A

2011-08-01

223

Starting points and objectives for a design study of a radioactive waste repository to be mined in a salt dome  

International Nuclear Information System (INIS)

In close cooperation with Prof.Ir. P.Th. Velzeboer, Professor in Mining of the University of Technology in Delft, a design study has been made of a radioactive waste repository to be mined in a medium size salt dome. This article focuses on the starting points and objectives that formed the basis of this design study. The prime objective was a high degree of radiological and of conventional safety during the construction and operation of the disposal mine and a long-term isolation of the buried radionuclides once the facility was closed down and sealed. (Auth.)

224

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

International Nuclear Information System (INIS)

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 sensitivitent 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.

225

Orbit Transfer Vehicle (OTV) advanced expander cycle engine point design study. Task 7: Engine data summary  

Science.gov (United States)

A performance optimized engine system design for a man-rated advanced LOX/hydrogen expander cycle engine was investigated. The data are presented in tables, figures, and drawings. The following categories of data for the advanced expander cycle engine are presented: engine operating specification and pressure schedule; engine system layout drawing; major component layout drawings, including thrust chamber and nozzle, extendible nozzle actuating mechanism and seal, LOX turbopump, LOX boost pump, hydrogen turbopump, hydrogen boost pump, and propellant control valves; engine performance and service life prediction; engine weight; and engine envelope. The data represent updates based upon current results from the design and analyses tasks performed under contract. Futher iterations in the designs and data can be expected as the advanced expander cycle engine design matures.

Christensen, K. L.

1980-01-01

226

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

227

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

228

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

OpenAIRE

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...

Sreekanth Yadav, K.

2013-01-01

229

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

OpenAIRE

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...

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

2011-01-01

230

A multi-point inverse airfoil design method based on conformal mapping  

Science.gov (United States)

An exact method of multipoint inverse airfoil design for incompressible flow is presented. Multipoint design is handled by dividing the airfoil into a number of desired segments. For each segment the velocity distribution is prescribed together with an angle of attack at which the prescribed velocity distribution is to be achieved. In this manner, multipoint design objectives can be taken into account in the initial specification of the velocity distribution. In order for the multipoint inverse airfoil design problem to be well posed, three integral constraints and several conditions arise which must be satisfied. Further restrictions are imposed if the airfoil is to have a specified pitching moment, thickness ratio, or other constraints. The system of equations is solved partly as a linear system and partly through multidimensional Newton iteration. Since the velocity distribution is prescribed about the circle in the angular coordinate, specification of the velocity in terms of arc length is handled through the multidimensional Newton iteration as well. The current formulation sets the stage for a more general multipoint inverse airfoil design method in which it will be possible to specify the velocity distribution, some boundary-layer development, or the surface geometry along a segment.

Selig, Michael S.; Maughmer, Mark D.

1991-01-01

231

Design point characteristics of a 500 - 2500 watt isotope-Brayton power system.  

Science.gov (United States)

An analytical study was conducted to investigate the potential performance characteristics of an isotope-Brayton space power system at electric power levels from 500 to 2500 W. Utilization of the Pu 238 heat source, or capsule, being developed for the Multi-Hundred Watt Radioisotope Thermoelectric Generator was assumed. A single-loop system design concept was selected. The design concept and results of first-order tradeoff studies of the effects of major system parameters on system performance are presented. Results of the study indicate the potential for high system efficiency and high specific power over the entire power range.

Barna, G. J.

1972-01-01

232

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.)

233

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

Scientific Electronic Library Online (English)

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.

Marina Storani de, Almeida; Luis Alberto, Carvalho.

2007-06-01

234

Advanced engineering design as practiced today from the view point of the CERN Industrial Liaison Officer  

OpenAIRE

After an introduction about CERN, a brief description of the Large Hadron Collider(LHC) it is reviewed. Pros and cons of a few advanced engineering design cases are taken in consideration together with the involvement of the European Industry. The conclusion is that the LHC project has been an important driving force for Innovation in European Industry.

Barone, Michele

2012-01-01

235

Advocacy for eye care  

OpenAIRE

The effectiveness of eye care service delivery is often dependant on how the different stakeholders are aligned. These stakeholders range from the ministries of health who have the capacity to grant government subsidies for eye care, down to the primary healthcare workers who can be enrolled to screen for basic eye diseases. Advocacy is a tool that can help service providers draw the attention of key stakeholders to a particular area of concern. By enlisting the support, endorsement and parti...

Ravilla, Thulasiraj D.; Ramasamy, Dhivya

2012-01-01

236

Teamwork for eye care  

OpenAIRE

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.

Babar Qureshi, M.

2014-01-01

237

Eye drop neurology.  

Science.gov (United States)

Eye drops can help to diagnose and prevent complications of neurological disorders. Guttae ophthalmicae (eye drops) are generally safe because the drugs rarely achieve significant systemic concentrations, although there are rare exceptions. This article covers contemporary pharmacological pupil testing; how to dilate a pupil safely; common reasons why pupils do not respond to drops; and corneal lubrication to prevent complications of weak eye closure. PMID:24520179

Bennetto, Luke; Guly, Catherine; Ormerod, Ian; Plant, Gordon T

2014-06-01

238

EYE BASED CONTROL SYSTEM  

OpenAIRE

In this paper, an individual human computer interface system using eye motion tracking is introduced. Traditionally human computer interface uses mouse, keyboard as an input device. However, the proposed vision-based virtual interface controls system work on various eye movements such as eye blinking. The planned virtual multimodal interface system provides vision-based mechanism, to convey between human and computer system, instead of conventional human computer interaction through mouse and...

Shrunkhala Satish Wankhede, Ms S. A. Chhabria

2012-01-01

239

Finite element and node point generation computer programs used for the design of toroidal field coils in tokamak fusion devices  

International Nuclear Information System (INIS)

The structural analysis of toroidal field coils in Tokamak fusion machines can be performed with the finite element method. This technique has been employed for design evaluations of toroidal field coils on the Princeton Large Torus (PLT), the Poloidal Diverter Experiment (PDX), and the Tokamak Fusion Test Reactor (TFTR). The application of the finite element method can be simplified with computer programs that are used to generate the input data for the finite element code. There are three areas of data input where significant automation can be provided by supplementary computer codes. These concern the definition of geometry by a node point mesh, the definition of the finite elements from the geometric node points, and the definition of the node point force/displacement boundary conditions. The node point forces in a model of a toroidal field coil are computed from the vector cross product of the coil current and the magnetic field. The computer programs named PDXNODE and ELEMENT are described. The program PDXNODE generates the geometric node points of a finite element model for a toroidal field coil. The program ELEMENT defines the finite elements of the model from the node points and from material property considerations. The program descriptions include input requirements, the output, the program logic, the methods of generating complex geometries with multiple runs, computational time and computer compatibility. The output format of PDXNODE and ELEMENT make themut format of PDXNODE and ELEMENT make them compatible with PDXFORC and two general purpose finite element computer codes: (ANSYS) the Engineering Analysis System written by the Swanson Analysis Systems, Inc., and (WECAN) the Westinghouse Electric Computer Analysis general purpose finite element program. The Fortran listings of PDXNODE and ELEMENT are provided

240

Optimization of mechanical properties of structures from the point of aseismic design  

International Nuclear Information System (INIS)

The vibroinsulation problem is solved by passive and active dynamic systems control methods. The attacking of the problem by design of vibroisolators that passively extinguish the harmful vibration has begun historically earlier. Quite in the latest years some attention has been drawn on the possibility about dynamical system's active control. But the questions about the technical realization at the optimal and the modal regulators making the behaviour safe during earthquake remains open until now. The optimal control theory application to the aims of the dynamical systems stability motion (systems being described as rigid, nondeformable solids) by a passive vibroinsulation is done. Thus the optimal dynamic system properties are identified without one having to solve the problem about a technical realization of active control equipments. An aim of this paper is an application of an optimal control theory to obtaining optimal elastic and dissipative characteristics of the buildings at their aseismic design

241

Design and Principles of Linear Accelerators and Colliders: Focusing at Interaction Point  

CERN Document Server

This document is part of Subvolume C 'Accelerators and Colliders' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the the Section '7.6 Wakefields and Emittance Preservation' of the Chapter '7 Design and Principles of Linear Accelerators and Colliders' with the content: 7.6 Wakefields and Emittance Preservation 7.6.1 Single-Bunch Wakefield-Induced Effects 7.6.2 Multi-Bunch Wakefield-Induced Effects

Latina, A

2013-01-01

242

Design of Ultrasonically-Activatable Nanoparticles using Low Boiling Point Perfluorocarbons  

OpenAIRE

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...

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

2012-01-01

243

Choosing Wisely When It Comes to Eye Care: Punctal Plugs for Dry Eye  

Science.gov (United States)

... Wisely When It Comes to Eye Care Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During ... and Eye Protection Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Opening Champagne Bottles ...

244

Choosing Wisely When It Comes to Eye Care: Antibiotics for Eye Injections  

Science.gov (United States)

... Wisely When It Comes to Eye Care Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During ... and Eye Protection Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Opening Champagne Bottles ...

245

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

Science.gov (United States)

... Wisely When It Comes to Eye Care Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During ... and Eye Protection Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Opening Champagne Bottles ...

246

Design and DSP implementation of star image acquisition and star point fast acquiring and tracking  

Science.gov (United States)

Star sensor is a special high accuracy photoelectric sensor. Attitude acquisition time is an important function index of star sensor. In this paper, the design target is to acquire 10 samples per second dynamic performance. On the basis of analyzing CCD signals timing and star image processing, a new design and a special parallel architecture for improving star image processing are presented in this paper. In the design, the operation moving the data in expanded windows including the star to the on-chip memory of DSP is arranged in the invalid period of CCD frame signal. During the CCD saving the star image to memory, DSP processes the data in the on-chip memory. This parallelism greatly improves the efficiency of processing. The scheme proposed here results in enormous savings of memory normally required. In the scheme, DSP HOLD mode and CPLD technology are used to make a shared memory between CCD and DSP. The efficiency of processing is discussed in numerical tests. Only in 3.5ms is acquired the five lightest stars in the star acquisition stage. In 43us, the data in five expanded windows including stars are moved into the internal memory of DSP, and in 1.6ms, five star coordinates are achieved in the star tracking stage.

Zhou, Guohui; Wang, Xiaodong; Hao, Zhihang

2006-02-01

247

Robot design from a neuro-ethological point of view. Shinkei kodogaku kara mita robot  

Energy Technology Data Exchange (ETDEWEB)

The science concerning the method of obtaining the desirable information by adjusting the controllable quantity based on the measurement of the uncontrollable quantity is called cybernetics. The cybernetics is the most ideal image of the robot. The instinct of animals is supported by the nervous system. The science which deals with the nervous system of animals as a function of its instinct is called the neuro-ethology. In this sense, the neuro-ethology is identical to the cybernetics. The fundamental basis of robot design the design of the robot is therefore the neuro-ethology. The treatment of the dependent information about space and time in the auditory nervous system of animals was reviewed. The petuliarity of the auditory system, auditory as an interferometry, and the evolution of the auditory system was explained by taking the sonner system in bats as a prototype of the auditory system of animal. For further explanation of auditory system, the correspondence to the phonetic recognition of Homo-sapiens was also reviewed. It is important for design of the robot to investigate the mechanism to extract informations of the auditory nervous system in animals including Homo-sapiens. 19 refs., 10 figs.

Shimozawa, T. (Hokkaido Univ., Sapporo (Japan). Research Inst. of Applied Electricity)

1991-11-01

248

New design and analysis for point-focusing of surface waves in contact testing.  

Science.gov (United States)

A method was presented for the intensive focusing of surface ultrasonic waves in contact testing, and an ultrasonic contact transducer was fabricated and characterized. The acoustic contact lens of the transducer was in a shape which was obtained by rotating a right-angled triangle having a critical angle for the generation of surface waves. PVDF film was employed as an ultrasonic transmitter and receiver. The fabricated transducer showed the focusing feature of a narrow lateral half width and high sound intensity at a focal point. Also, a simple model was presented to estimate theoretically the stress pattern on a symmetry axis of the transducer. The stress pattern predicted using the model showed good agreement with the experimental result. This concept can also be used in acoustic microscopy. PMID:18263170

Kim, B G; Lee, J O; Lee, S

1993-01-01

249

Design and evaluation of an optical fine-pointing control system for telescopes utilizing a digital star sensor  

Science.gov (United States)

One of the most significant problems associated with the development of large orbiting astronomical telescopes is that of maintaining the very precise pointing accuracy required. A proposed solution to this problem utilizes dual-level pointing control. The primary control system maintains the telescope structure attitude stabilized within the field of view to the desired accuracy. In order to demonstrate the feasibility of optically stabilizing the star images to the desired accuracy a regulating system has been designed and evaluated. The control system utilizes a digital star sensor and an optical star image motion compensator, both of which have been developed for this application. These components have been analyzed mathematically, analytical models have been developed, and hardware has been built and tested.

Ostroff, A. J.; Romanczyk, K. C.

1973-01-01

250

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

DEFF Research Database (Denmark)

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.

Eichhorn, V; Fatikow, S

2010-01-01

251

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... have other eye surgery later, such as cataract surgery. Bring this "K Card" with you to your Eye M.D. appointment to have it completed and keep it for future use. Questions to Ask When Considering LASIK If ...

252

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 Six Smart Things College Students Should Do For ...

253

Eye-Tracking  

Directory of Open Access Journals (Sweden)

Full Text Available Eye-tracking: one of the newest and most efficient methods of improving on-line marketing communication is called eye-tracking. Marketers have borrowed this technique, usually used in psychological and medical research, in order to study web users with the help of a video camera incorporated in the monitor.

Gabriela GROSSECK

2006-01-01

254

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 ...

255

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... correcting vision with surgery rather than eyeglasses or contact lenses. Next 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 > Privacy Policy > Featured Video ...

256

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... dry eye"; glare, halos or starbursts around lights; light sensitivity; discomfort or pain; or small pink or red patches on the white of the eye. In a small minority of patients, some of these effects may be permanent. Sometimes a second surgery, called ...

257

Foreign Body in Eye  

Science.gov (United States)

... foreign object gets in the eye. If you play a sport, use goggles to protect your eyes from sand, dirt and other objects. If you need glasses to see clearly, you can have goggles made with prescription lenses. If you wear contact lenses, wash your hands thoroughly before you handle ...

258

What Is Dry Eye?  

Medline Plus

Full Text Available ... 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 Infections Detached & Torn Retina Diabetic Retinopathy Dry Eye Floaters & Flashes Glaucoma Hyperopia ( ...

259

Recent developments in and prospects of PWR design in France from the point of view of safety and reliability  

International Nuclear Information System (INIS)

The paper describes recent developments in the French approach to safety and its prospects with respect to the design and operation of pressurized water reactors. It emphasizes the advantage deriving from a single facility design when it comes to improving the reliability of systems and reducing risks due to human error; various examples of simplifications introduced in French reactors are given. Concern with simplification should not work to the detriment of the availability of safety functions. Thus, a systematic examination is carried out to demonstrate that the system design adopted leads to a general safety level which is satisfactory. Various examples are given to justify a two track safety design. An analysis of the loss of redundant systems is presented. The operational safety developments are mentioned; these relate to the training of personnel, feedback of operational experience and the introduction of symptom based procedures. In addition to efforts at simplification and coherence, particular attention has been paid to allowance for serious accidents involving core meltdown, and it is shown how the definition of emergency plans is compatible with the serious accidents to be taken into account. The prospects of development outlined emphasize the solid foundation represented by the present safety philosophy. This foundation is the starting point for any future development which might take place, possibly including allowance for serious accidents in design or owance for serious accidents in design or the search for designs less sensitive to situations of the second and third categories, and which must be based on an international consensus. (author). 2 figs, 1 tab

260

Sex/Gender Disparities and Women's Eye Health.  

Science.gov (United States)

Abstract Our eyes are, both literally and figuratively, windows to the world, and ophthalmic approaches offer a tremendous space for conducting research to learn more. Male/female differences in ocular health and disease are prevalent but we know far too little about root causes to design and implement diagnostic, preventive, and treatment strategies to address sex- and gender-based disparities in eye health. Herein, we discuss several ophthalmic diseases and other conditions with ocular manifestations, with a focus upon those that disproportionately affect women. Because the vast majority of biomedical research in this area comes from studies of mixed-gender populations, or of male-predominant populations, there is a pressing need for sex- and/or gender-based research at various points along the basic to clinical biomedical research continuum. Moreover, the multitude of factors that affect eye health call for a balanced look at the influence of biology, culture, and societal contributors. As clinicians, we owe our patients the best care for their needs, and that care must be derived from research that shows what is effective, for whom, and under what conditions. PMID:25548854

Clayton, Janine A; Davis, Alison F

2015-02-01

261

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

Directory of Open Access Journals (Sweden)

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

K.Sreekanth Yadav

2013-02-01

262

An approach to optimal architectural and urban design from the energy efficiency point of view  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a new approach to architecture and urban design that results in an increase of the energy efficiency of buildings set close to each other, which is set as the optimization problem. The main goal is to maximize the sunlight impact on objects, in a way to minimize inter-object shading on each building. The problem is solved by the PSO (Particle Swarm Optimization algorithm and its modifications, as well as the application of PSO algorithm with niches, which makes it possible to find a large number of local optima. It turned out that the PSO algorithm with niches is especially suitable for solving the described problems. The proposed methodology is illustrated by a few examples.

Kapetina Mirna N.

2014-01-01

263

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 ... on the arrows below for detailed information about Medicare benefits and your eyes. Request a Free Copy ...

264

Financial Aid for Eye Care  

Science.gov (United States)

... the Clinical Director Education Programs All Education National Eye Health Education Program Diabetic Eye Disease Education Program Glaucoma ... may help you buy corrective eyewear or obtain eye health care. To find a Lions club near you, ...

265

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

Energy Technology Data Exchange (ETDEWEB)

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.

D. M. McEligot; G. E. McCreery

2004-09-01

266

Evaluating the effect of four different pointing device designs on upper extremity posture and muscle activity during mousing tasks.  

Science.gov (United States)

The goal of this study was to evaluate the effect of different types of computer pointing devices and placements on posture and muscle activity of the hand and arm. A repeated measures laboratory study with 12 adults (6 females, 6 males) was conducted. Participants completed two mouse-intensive tasks while using a conventional mouse, a trackball, a stand-alone touchpad, and a rollermouse. A motion analysis system and an electromyography system monitored right upper extremity postures and muscle activity, respectively. The rollermouse condition was associated with a more neutral hand posture (lower inter-fingertip spread and greater finger flexion) along with significantly lower forearm extensor muscle activity. The touchpad and rollermouse, which were centrally located, were associated with significantly more neutral shoulder postures, reduced ulnar deviation, and lower forearm extensor muscle activities than other types of pointing devices. Users reported the most difficulty using the trackball and touchpad. Rollermouse was not more difficult to use than any other devices. These results show that computer pointing device design and location elicit significantly different postures and forearm muscle activities during use, especially for the hand posture metrics. PMID:25479996

Lin, Michael Y C; Young, Justin G; Dennerlein, Jack T

2015-03-01

267

Testing of an End-Point Control Unit Designed to Enable Precision Control of Manipulator-Coupled Spacecraft  

Science.gov (United States)

This paper presents an end-point control concept designed to enable precision telerobotic control of manipulator-coupled spacecraft. The concept employs a hardware unit (end-point control unit EPCU) that is positioned between the end-effector of the Space Shuttle Remote Manipulator System and the payload. Features of the unit are active compliance (control of the displacement between the end-effector and the payload), to allow precision control of payload motions, and inertial load relief, to prevent the transmission of loads between the end-effector and the payload. This paper presents the concept and studies the active compliance feature using a simulation and hardware. Results of the simulation show the effectiveness of the EPCU in smoothing the motion of the payload. Results are presented from initial, limited tests of a laboratory hardware unit on a robotic arm testbed at the l Space Flight Center. Tracking performance of the arm in a constant speed automated retraction and extension maneuver of a heavy payload with and without the unit active is compared for the design speed and higher speeds. Simultaneous load reduction and tracking performance are demonstrated using the EPCU.

Montgomery, Raymond C.; Ghosh, Dave; Tobbe, Patrick A.; Weathers, John M.; Manouchehri, Davoud; Lindsay, Thomas S.

1994-01-01

268

(abstract) The Design of a Benign Fail-safe Mechanism Using a Low-melting-point Metal Alloy Coupler  

Science.gov (United States)

Because the alpha proton X ray spectrometer (APXS) sensor head on the Mars Pathfinder rover, Sojourner, is placed on Martian soil by the deployment mechanism (ADM), the rover would be crippled if the actuator fails when the mechanism is in its deployed position, as rover ground clearance is then reduced to zero. This paper describes the unique fail-safe mounted on the ADM, especially the use of a low-temperature-melting alloy as a coupler device. The final form of the design is a low-melting-point metal pellet coupler, made from Cerrobend, in parallel with a Negator spring pack. In its solid state, the metal rigidly connects the driver (the actuator) and the driven part (the mechanism). When commanded, a strip heater wrapped around the coupler melts the metal pellet (at 60(deg)C), allowing the driven part to turn independent of the driver. The Negator spring retracts the mechanism to its fully stowed position. This concept meets all the design criteria, and provides an added benefit. When the metal hardens the coupler once again rigidly connects the actuator and the mechanism. The concept presented here can easily be applied to other applications. Anywhere release devices are needed, low-melting-point couplers can be considered. The issues to be concerned with are thermal isolation, proper setting of the parts before actuation, and possible outgassing concerns. However, when these issues are overcome, the resulting release mechanism can promise to be the most light, simple, power conserving alternative available.

Blomquist, Richard S.

1995-01-01

269

Recognizing and Treating Eye Injuries  

Science.gov (United States)

... Eye) Astigmatism Bacterial Keratitis Bell's Palsy Blepharitis Cataracts Contact Lens-Related Infections Detached & Torn Retina Diabetic Retinopathy Dry Eye Floaters & Flashes Glaucoma Hyperopia (Farsightedness) Low Vision ...

270

Keeping an eye on retinoic acid signaling during eye development.  

Science.gov (United States)

Retinoic acid is a metabolic derivative of vitamin A that plays an essential function in cell-cell signaling by serving as a ligand for nuclear receptors that directly regulate gene expression. The final step in the conversion of retinol to retinoic acid is carried out by three retinaldehyde dehydrogenases encoded by Raldh1 (Aldh1a1), Raldh2 (Aldh1a2), and Raldh3 (Aldh1a3). Mouse Raldh gene knockout studies have been instrumental in understanding the mechanism of retinoic acid action during eye development. Retinoic acid signaling in the developing eye is particularly complex as all three Raldh genes contribute to retinoic acid synthesis in non-overlapping locations. During optic cup formation Raldh2 is first expressed transiently in perioptic mesenchyme, then later Raldh1 and Raldh3 expression begins in the dorsal and ventral retina, respectively, and these sources of retinoic acid are maintained in the fetus. Retinoic acid is not required for dorsoventral patterning of the retina as originally thought, but it is required for morphogenetic movements that form the optic cup, ventral retina, cornea, and eyelids. These findings will help guide future studies designed to identify retinoic acid target genes during eye organogenesis. PMID:18831967

Duester, Gregg

2009-03-16

271

Data eye monitor method and apparatus  

Science.gov (United States)

An apparatus and method for providing a data eye monitor. The data eye monitor apparatus utilizes an inverter/latch string circuit and a set of latches to save the data eye for providing an infinite persistent data eye. In operation, incoming read data signals are adjusted in the first stage individually and latched to provide the read data to the requesting unit. The data is also simultaneously fed into a balanced XOR tree to combine the transitions of all incoming read data signals into a single signal. This signal is passed along a delay chain and tapped at constant intervals. The tap points are fed into latches, capturing the transitions at a delay element interval resolution. Using XORs, differences between adjacent taps and therefore transitions are detected. The eye is defined by segments that show no transitions over a series of samples. The eye size and position can be used to readjust the delay of incoming signals and/or to control environment parameters like voltage, clock speed and temperature.

Gara, Alan G. (Mount Kisco, NY); Marcella, James A. (Rochester, MN); Ohmacht, Martin (Yorktown Heights, NY)

2012-01-31

272

Perceptions of eye health in schools in Pakistan  

Directory of Open Access Journals (Sweden)

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.

Qureshi Mohammad

2006-03-01

273

Case study: improving the management of eye care programmes  

OpenAIRE

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 b...

Kolawole Olumide Ogundimu

2008-01-01

274

Designs for Testing Group-Based Interventions with Limited Numbers of Social Units: The Dynamic Wait-Listed and Regression Point Displacement Designs.  

Science.gov (United States)

The dynamic wait-listed design (DWLD) and regression point displacement design (RPDD) address several challenges in evaluating group-based interventions when there is a limited number of groups. Both DWLD and RPDD utilize efficiencies that increase statistical power and can enhance balance between community needs and research priorities. The DWLD blocks on more time units than traditional wait-listed designs, thereby increasing the proportion of a study period during which intervention and control conditions can be compared, and can also improve logistics of implementing intervention across multiple sites and strengthen fidelity. We discuss DWLDs in the larger context of roll-out randomized designs and compare it with its cousin the Stepped Wedge design. The RPDD uses archival data on the population of settings from which intervention unit(s) are selected to create expected posttest scores for units receiving intervention, to which actual posttest scores are compared. High pretest-posttest correlations give the RPDD statistical power for assessing intervention impact even when one or a few settings receive intervention. RPDD works best when archival data are available over a number of years prior to and following intervention. If intervention units were not randomly selected, propensity scores can be used to control for non-random selection factors. Examples are provided of the DWLD and RPDD used to evaluate, respectively, suicide prevention training (QPR) in 32 schools and a violence prevention program (CeaseFire) in two Chicago police districts over a 10-year period. How DWLD and RPDD address common threats to internal and external validity, as well as their limitations, are discussed. PMID:25481512

Wyman, Peter A; Henry, David; Knoblauch, Shannon; Brown, C Hendricks

2014-12-01

275

Overcoming Presbyopia by Manipulating the Eyes' Optics  

Science.gov (United States)

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.

Zheleznyak, Leonard A.

276

LASIK - Laser Eye Surgery  

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Full Text Available ... Are You Fit at 40? A baseline eye exam is recommended at age 40, when the signs ... risks — including quality of life issues — that could result from correcting vision with surgery rather than eyeglasses ...

277

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... battery and always wear safety goggles. Eye Protection Works Wearing the proper protective eyewear for sports and ... close-up focusing power. How the LASIK procedure works LASIK is performed while the patient reclines under ...

278

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... to wash your hands frequently. Replace the Case Contact lens cases should be replaced at least every three months to prevent eye infection. What Is an Ophthalmologist? Make sure ...

279

What Is Dry Eye?  

Medline Plus

Full Text Available ... Devin Harrison on March 1, 2014 Search for Questions & Answers Search QA Browse all answered questions > Related ... sponsorship & advertising policies about us Educational Resources EyeWiki contact us sitemap Reproducing text or images from this ...

280

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... your Eye M.D. the benefits and risks — including quality of life issues — that could result from correcting vision with surgery rather than eyeglasses or contact lenses. Next Page: Alternative Refractive Surgery Procedures Find ...

281

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... Never lean over the battery and always wear safety goggles. Eye Protection Works Wearing the proper protective ... LASIK procedure works LASIK is performed while the patient reclines under a surgical device called an excimer ...

282

Eye Injuries in Sports  

Science.gov (United States)

... and severity of eye injuries. Only 3-mm polycarbonate lenses should be used in protective sports eyewear. ... lenses are available in plain and prescription forms. Polycarbonate lenses are impact resistant. They also are the ...

283

Down Syndrome: Eye Problems  

Science.gov (United States)

... early age. The most common eye findings include: • Refractive errors - Children with Down syndrome are more likely to ... This may be due to myopia (near-sightedness), hyperopia (far-sightedness), or astigmatism. The refractive errors may ...

284

Diabetes and eye disease  

Science.gov (United States)

... of the retina that provides sharp central vision Retinal detachment -- scarring that may cause part of the retina ... eye. It may also be used to repair retinal detachment . Medicines that are injected into the eyeball may ...

285

Aging and Your Eyes  

Science.gov (United States)

... of a more serious eye problem such as retinal detachment. If you see many new floaters and/or ... surgery can sometimes prevent it from getting worse. Retinal detachment. THIS IS A MEDICAL EMERGENCY. When the retina ...

286

Eye banking: an introduction  

Directory of Open Access Journals (Sweden)

Full Text Available This article introduces the work of eye banks, institutions responsible for collecting (harvesting and processing donor corneas, and for distributing them to trained corneal graft surgeons.

Gullapalli N Rao

2009-12-01

287

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 ...

288

What Is Dry Eye?  

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Full Text Available ... 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 ...

289

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... an ophthalmologist (Eye M.D.) creates a thin flap in the cornea using either a blade or a laser. The surgeon folds back the flap and precisely removes a very specific amount of ...

290

Diabetes - Eye Complications  

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Full Text Available ... diseases can be prevented or delayed through good diabetes management. When they occur, these diseases can be treated ... as retinopathy, cataract, and glaucoma. Prevention through successful management of diabetes helps prevent and delay these eye diseases. Management ...

291

Multimodal eye recognition  

Science.gov (United States)

Multimodal biometrics use more than one means of biometric identification to achieve higher recognition accuracy, since sometimes a unimodal biometric is not good enough used to do identification and classification. In this paper, we proposed a multimodal eye recognition system, which can obtain both iris and sclera patterns from one color eye image. Gabor filter and 1-D Log-Gabor filter algorithms have been applied as the iris recognition algorithms. In sclera recognition, we introduced automatic sclera segmentation, sclera pattern enhancement, sclera pattern template generation, and sclera pattern matching. We applied kernelbased matching score fusion to improve the performance of the eye recognition system. The experimental results show that the proposed eye recognition method can achieve better performance compared to unimodal biometric identification, and the accuracy of our proposed kernel-based matching score fusion method is higher than two classic linear matching score fusion methods: Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA).

Zhou, Zhi; Du, Yingzi; Thomas, N. L.; Delp, Edward J., III

2010-04-01

292

LASIK - Laser Eye Surgery  

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Full Text Available ... LASIK Surgery: Why All Patients Need the K Card (PDF 650K) If you have decide to have ... later, such as cataract surgery. Bring this "K Card" with you to your Eye M.D. appointment ...

293

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.

294

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... least every three months to prevent eye infection. What Is an Ophthalmologist? Make sure you are seeing ... risks and benefits, and have realistic expectations about what your vision will be like after surgery and ...

295

Diabetes - Eye Complications  

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Full Text Available ... of the eyes are small. When they become weak, they leak, burst, or become blocked. Diabetic Retinopathy ... of the retina may leak if they are weak. This can cause swelling in the retina, which ...

296

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... process. LASIK Surgery: Why All Patients Need the K Card (PDF 650K) If you have decide to ... surgery later, such as cataract surgery. Bring this "K Card" with you to your Eye M.D. ...

297

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... difficulty with night vision and/or driving at night; scratchiness, dryness and other symptoms of the condition called "dry eye"; glare, halos or starbursts around lights; light sensitivity; discomfort or pain; or small pink ...

298

What Is Dry Eye?  

Medline Plus

Full Text Available ... 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 Infections Detached & Torn Retina Diabetic ...

299

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... Eye M.D. the benefits and risks — including quality of life issues — that could result from correcting vision with surgery ... by Name, City, State or Subspecialty > Ask An ...

300

The watery eye.  

Science.gov (United States)

The surface of the eye needs to be wet constantly to ensure its integrity in maintaining ocular comfort, clear vision, and ocular health. This article presents new findings in the tear dynamics of the human eye, with an emphasis on the tear meniscus and tear film through the day and in response to punctual occlusion and wearing of contact lenses. Recent advances in imaging technique are briefly discussed. PMID:21302004

Wang, Jianhua; Shen, Meixiao; Cui, Lele; Wang, Michael R

2011-06-01

301

Children's Eye Injuries: Prevention and Care  

Science.gov (United States)

... What Is an Ophthalmologist? Your Eyes & the Sun Eye Health News Consumer Alerts Children’s Eye Injuries: Prevention and ... Get eye MD-reviewed tips and information about eye health and preserving your vision. Privacy Policy Email address ...

302

Contact Lens-Related Eye Infections  

Science.gov (United States)

... What Is an Ophthalmologist? Your Eyes & the Sun Eye Health News Consumer Alerts Contact Lens-Related Eye Infections ... Get eye MD-reviewed tips and information about eye health and preserving your vision. Privacy Policy Email address © ...

303

Eye Health in Sports and Recreation  

Science.gov (United States)

... Eyes & the Sun Eye Health News Consumer Alerts Eye Health in Sports and Recreation Tweet Tens of thousands ... Get eye MD-reviewed tips and information about eye health and preserving your vision. Privacy Policy Email address ...

304

Hardware description ADSP-21020 40-bit floating point DSP as designed in a remotely controlled digital CW Doppler radar  

Science.gov (United States)

A continuous wave Doppler radar system has been designed which is portable, easily deployed, and remotely controlled. The heart of this system is a DSP/control board using Analog Devices ADSP-21020 40-bit floating point digital signal processor (DSP) microprocessor. Two 18-bit audio A/D converters provide digital input to the DSP/controller board for near real time target detection. Program memory for the DSP is dual ported with an Intel 87C51 microcontroller allowing DSP code to be up-loaded or down-loaded from a central controlling computer. The 87C51 provides overall system control for the remote radar and includes a time-of-day/day-of-year real time clock, system identification (ID) switches, and input/output (I/O) expansion by an Intel 82C55 I/O expander.

Morrison, R. E.; Robinson, S. H.

305

Model eyes for evaluation of intraocular lenses.  

Science.gov (United States)

In accordance with the present international standard for intraocular lenses (IOLs), their imaging performance should be measured in a model eye having an aberration-free cornea. This was an acceptable setup when IOLs had all surfaces spherical and hence the measured result reflected the spherical aberration of the IOL. With newer IOLs designed to compensate for the spherical aberration of the cornea there is a need for a model eye with a physiological level of spherical aberration in the cornea. A literature review of recent studies indicated a fairly high amount of spherical aberration in human corneas. Two model eyes are proposed. One is a modification of the present ISO standard, replacing the current achromat doublet with an aspheric singlet cut in poly(methyl methacrylate) (PMMA). The other also has an aspheric singlet cut in PMMA, but the dimensions of it and the entire model eye are close to the physiological dimensions of the eye. They give equivalent results when the object is at infinity, but for finite object distances only the latter is correct. The two models are analyzed by calculation assuming IOLs with different degrees of asphericity to elucidate their sensitivity to variation and propose tolerances. Measured results in a variant of the modified ISO model eye are presented. PMID:17846654

Norrby, Sverker; Piers, Patricia; Campbell, Charles; van der Mooren, Marrie

2007-09-10

306

AN INNER STRUGGLE: UNDER WESTERN EYES  

Directory of Open Access Journals (Sweden)

Full Text Available This study aims to shed light on the most significant aspect of the modern man’s inner struggle in Joseph Conrad’s Under Western Eyes. Joseph Conrad is one of the authors of the twentieth century who was influenced by the psychological philosophy and he makes use of this influence in his works deeply. He who synthesizes the inner nature of the modern man, having conflicts himself with the deeper analysis field of the psychology aims to point out the incomprehensible and unsettled inner nature of the modern man in Under Western Eyes.

Hale Ya?l?dere

2013-06-01

307

Design and implementation of a microcontroller-based maximum power point tracking fuzzy solar-charge controller  

Energy Technology Data Exchange (ETDEWEB)

Photovoltaic (PV) solar arrays are particularly useful for electrical power generation in remote, off-grid areas in developing countries. However, PV arrays offer a small power to area ratio, resulting in the need for more PV arrays which increases the cost of the system. In order to improve the profitability of PV arrays, the power extraction from available PV array systems must be maximized. This paper presented an analysis, modeling and implementation of an efficient solar charge controller. It was shown that the maximum power of a photovoltaic system depends largely on temperature and insolation. A perturb and observe algorithm was used for maximum power point tracking (MPPT). MPPT maximizes the efficiency of a solar PV system. A solar charge controller determines the optimal values of output current and voltage of converters to maximize power output for battery charging. In order to improve performance and implement the perturb and observe algorithm, the authors designed a fuzzy rule-based system in which a solar charge controller worked with a PWM controlled DC-DC converter for battery charging. The system was implemented on a low-cost PIC microcontroller. Results were better than conventional techniques in power efficiency. Swift maximum power point tracking was obtained. 13 refs., 1 tab., 11 figs.

Qazalbash, A.A.; Iqbal, T.; Shafiq, M.Z. [National Univ. of Sciences and Technology, Rawalpindi (Pakistan). Dept. of Electrical Engineering

2007-07-01

308

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)

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:…

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

2013-01-01

309

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

Science.gov (United States)

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

Heiderscheidt, Elisangela; Leiviskä, Tiina; Kløve, Bjørn

2015-03-01

310

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

311

The injured eye.  

Science.gov (United States)

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 meticulous history taking, evaluation of vision that measures the acuity and if there is a relative pupillary defect as well as careful inspection of the eyes, under anaesthetic if necessary. A lateral canthotomy with cantholysis should be performed immediately if there is a sight-threatening retrobulbar haemorrhage. Systemic antibiotics should be prescribed if there is a suspected penetrating or perforating injury. A ruptured globe should be protected by an eye shield. Primary repair of ruptured globes should be performed in a timely fashion. Secondary procedures will often be required at a later date to achieve sight preservation. A poor initial visual acuity is not a guarantee of a poor final result. The final result can be predicted after approximately 3-4 weeks. Future research in eye injuries attempts to reduce scarring and neuronal damage as well as to promote photoreceptor rescue, using post-transcriptional inhibition of cell death pathways and vaccination to promote neural recovery. Where the sight has been lost sensory substitution of a picture from a spectacle mounted video camera to the touch receptors of the tongue can be used to achieve appreciation of the outside world. PMID:21149360

Scott, Robert

2011-01-27

312

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)

313

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

DEFF Research Database (Denmark)

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 IrisPlex SNPs (HERC2 rs12913832, OCA2 rs1800407, SLC24A4 rs12896399, TYR rs1393350, SLC45A2 rs16891982 and IRF4 rs12203592) were analyzed in 570 individuals. Significant differences (p

Andersen, Jeppe D; Johansen, Peter

2013-01-01

314

Status of eye lens radiation dose monitoring in European hospitals.  

Science.gov (United States)

A questionnaire was developed by the members of WG12 of EURADOS in order to establish an overview of the current status of eye lens radiation dose monitoring in hospitals. The questionnaire was sent to medical physicists and radiation protection officers in hospitals across Europe. Specific topics were addressed in the questionnaire such as: knowledge of the proposed eye lens dose limit; monitoring and dosimetry issues; training and radiation protection measures. The results of the survey highlighted that the new eye lens dose limit can be exceeded in interventional radiology procedures and that eye lens protection is crucial. Personnel should be properly trained in how to use protective equipment in order to keep eye lens doses as low as reasonably achievable. Finally, the results also highlighted the need to improve the design of eye dosemeters in order to ensure satisfactory use by workers. PMID:25222935

Carinou, Eleftheria; Ginjaume, Merce; O'Connor, Una; Kopec, Renata; Sans Merce, Marta

2014-12-01

315

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

Directory of Open Access Journals (Sweden)

Full Text Available 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, EEG amplifier are used. These EEG signals are placed to capture brain waves. These brain waves are controlled by microcontroller and it produce analog waves. To convert analog waves to digital output Analog to digital converter is used. Object Sensor is used to avoid obstacles in its path respectively. The main contribution of the work is the combination of several technologies and techniques that came from different areas such as mechanical, electronic engineering. Driver circuit with relay are used to move wheelchair automatically. ZigBee is used for long transmission of wheelchair. Accelerometer and interfacing circuit are done by using head movement. DLOA algorithm used to avoid obstacles while reaching destination point. The target coordinates of the destination place using EEG, to reduce delay for auto navigation process.

D.Uma Mageswar

2013-05-01

316

Design and Study on Sliding Mode Extremum Seeking Control of the Chaos Embedded Particle Swarm Optimization for Maximum Power Point Tracking in Wind Power Systems  

OpenAIRE

This paper proposes a sliding mode extremum seeking control (SMESC) of chaos embedded particle swarm optimization (CEPSO) Algorithm, applied to the design of maximum power point tracking in wind power systems. Its features are that the control parameters in SMESC are optimized by CEPSO, making it unnecessary to change the output power of different wind turbines, the designed in-repetition rate is reduced, and the system control efficiency is increased. The wind power system control is designe...

Jui-Ho Chen; Her-Terng Yau; Weir Hung

2014-01-01

317

A randomised controlled trial investigating the effect of nutritional supplementation on visual function in normal, and age-related macular disease affected eyes: design and methodology [ISRCTN78467674  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Age-related macular disease is the leading cause of blind registration in the developed world. One aetiological hypothesis involves oxidation, and the intrinsic vulnerability of the retina to damage via this process. This has prompted interest in the role of antioxidants, particularly the carotenoids lutein and zeaxanthin, in the prevention and treatment of this eye disease. Methods The aim of this randomised controlled trial is to determine the effect of a nutritional supplement containing lutein, vitamins A, C and E, zinc, and copper on measures of visual function in people with and without age-related macular disease. Outcome measures are distance and near visual acuity, contrast sensitivity, colour vision, macular visual field, glare recovery, and fundus photography. Randomisation is achieved via a random number generator, and masking achieved by third party coding of the active and placebo containers. Data collection will take place at nine and 18 months, and statistical analysis will employ Student's t test. Discussion A paucity of treatment modalities for age-related macular disease has prompted research into the development of prevention strategies. A positive effect on normals may be indicative of a role of nutritional supplementation in preventing or delaying onset of the condition. An observed benefit in the age-related macular disease group may indicate a potential role of supplementation in prevention of progression, or even a degree reversal of the visual effects caused by this condition.

Eperjesi Frank

2003-10-01

318

The Tehran Eye Study: research design and eye examination protocol  

OpenAIRE

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 appropri...

Fotouhi Akbar; Hashemi Hassan; Mohammad Kazem

2003-01-01

319

Photorefraction of the Eye  

Science.gov (United States)

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.

Colicchia, Giuseppe; Wiesner, Hartmut; Zollman, Dean

2015-02-01

320

Fireworks and the eye.  

OpenAIRE

A prospective study involving all casualty departments in Trent Region and 81% of the major eye units in UK was performed to determine ocular morbidity from the use of fireworks during 1986. A serious injury was defined as involving admission to hospital and/or intraocular damage. Of all the injuries from fireworks, 16.7% seen at major eye units were serious and were caused by rockets or exploding fireworks (P less than 0.001). Only 53% of all injuries and 12.5% of serious injuries involved c...

Vernon, S. A.

1988-01-01

321

On the use of schematic eye models to estimate retinal image quality  

Science.gov (United States)

The optical performance of the eyes of nine vertebrate species was evaluated using optical system design techniques and schematic eye models. Essential features of eyes, including the modulation transfer function (MTF) and the MTF cutoff frequency are related to the numerical aperture of the eyes. Superior resolution for in vivo imaging of photoreceptors may be achieved by dilating the iris pupil of an eye, minimizing coherence, and using short wavelength illumination. The difference of lateral and axial resolution between a small and a large eye for imaging photoreceptors in vivo.

Li, Guo; Zwick, Harry; Stuck, Bruce E.; Lund, David J.

2000-07-01

322

Gaze Estimation for Off-Angle Iris Recognition Based on the Biometric Eye Model  

Energy Technology Data Exchange (ETDEWEB)

Iris recognition is among the highest accuracy biometrics. However, its accuracy relies on controlled high quality capture data and is negatively affected by several factors such as angle, occlusion, and dilation. Non-ideal iris recognition is a new research focus in biometrics. In this paper, we present a gaze estimation method designed for use in an off-angle iris recognition framework based on the ANONYMIZED biometric eye model. Gaze estimation is an important prerequisite step to correct an off-angle iris images. To achieve the accurate frontal reconstruction of an off-angle iris image, we first need to estimate the eye gaze direction from elliptical features of an iris image. Typically additional information such as well-controlled light sources, head mounted equipment, and multiple cameras are not available. Our approach utilizes only the iris and pupil boundary segmentation allowing it to be applicable to all iris capture hardware. We compare the boundaries with a look-up-table generated by using our biologically inspired biometric eye model and find the closest feature point in the look-up-table to estimate the gaze. Based on the results from real images, the proposed method shows effectiveness in gaze estimation accuracy for our biometric eye model with an average error of approximately 3.5 degrees over a 50 degree range.

Karakaya, Mahmut [ORNL; Barstow, Del R [ORNL; Santos-Villalobos, Hector J [ORNL; Thompson, Joseph W [ORNL; Bolme, David S [ORNL; Boehnen, Chris Bensing [ORNL

2013-01-01

323

Gaze estimation for off-angle iris recognition based on the biometric eye model  

Science.gov (United States)

Iris recognition is among the highest accuracy biometrics. However, its accuracy relies on controlled high quality capture data and is negatively affected by several factors such as angle, occlusion, and dilation. Non-ideal iris recognition is a new research focus in biometrics. In this paper, we present a gaze estimation method designed for use in an off-angle iris recognition framework based on the ORNL biometric eye model. Gaze estimation is an important prerequisite step to correct an off-angle iris images. To achieve the accurate frontal reconstruction of an off-angle iris image, we first need to estimate the eye gaze direction from elliptical features of an iris image. Typically additional information such as well-controlled light sources, head mounted equipment, and multiple cameras are not available. Our approach utilizes only the iris and pupil boundary segmentation allowing it to be applicable to all iris capture hardware. We compare the boundaries with a look-up-table generated by using our biologically inspired biometric eye model and find the closest feature point in the look-up-table to estimate the gaze. Based on the results from real images, the proposed method shows effectiveness in gaze estimation accuracy for our biometric eye model with an average error of approximately 3.5 degrees over a 50 degree range.

Karakaya, Mahmut; Barstow, Del; Santos-Villalobos, Hector; Thompson, Joseph; Bolme, David; Boehnen, Christopher

2013-05-01

324

Optimization of point sources on thin films using a statistical design approach. Application to 60Co sources  

International Nuclear Information System (INIS)

Radioactive point sources prepared by depositing weighed drops on thin membranes are commonly used in ionizing radiation metrology for 47??-? coincidence counting or for low energy electrons spectrometry. The present study deals with the preparation of good quality sources having high detection yields. Some influential parameters on the source quality are studied using 60Co as radioactive tracer. An approach based on experimental statistical designs has been chosen. This approach allows us to obtain reliable results with a number of experiences lower than in the case of a systematic approach. Homogeneous 60Co sources with high metrological qualifies (R?> 96 %) can be prepared using a direct deposit of ? 5 mg drops of 60Co solution ([Co] = 12 ?g/g), [HCl] = 0,5 mol/I) and dried at 60 deg C. The support of the radioactive spot is constituted with a gold coated (130 ?g/cm2 of Au) Vyns films (thickness 45 ?g/cm2) on which a pad (diameter = 7 - 8 mm) of polystyrene microspheres (Estapor K-007) is prepared by an electro-spraying technique under 7,5 kV during 10 minutes. The alcoholic solution used for the electro-spraying step has the following chemical composition [Estapor K-007] 2.5 10-2 wt % and [Tween 20] = 2.7 10-2 wt %. (authors)

325

Design of A Novel 8-point Modified R2MDC with Pipelined Technique for High Speed OFDM Applications  

Directory of Open Access Journals (Sweden)

Full Text Available This study presents, design of modified R2MDC with pipelined Technique. Radix-2 Multipath Delay commutators is the one type of Radix-2 FFT. Wireless networks have found a significant place in the growing technologies. Orthogonal Frequency Division Multiplexing (OFDM is a key technique used in wireless networks for high speed operation, high data capacity and spectral efficiency. The Fast Fourier Transform (FFT are essential in the field of Digital Signal Processing (DSP, widely used in communication systems, especially in Orthogonal Frequency Division Multiplexing (OFDM systems. Not a lot of research has been done on modified R2MDC FFT in OFDM. In this study, we propose a modified R2MDC 8-Point FFT in which pipelining technique is used in each Butterfly unit architecture. Using this technique through VLSI simulations it is found to reduce the delay and increase the throughput and hence is suitable for OFDM. This method can be extended to OFDM implementation that is apt for Wireless Networks.

S. Prabu

2014-06-01

326

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

Science.gov (United States)

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.

Rasouli, H.; Fatehi, A.

2014-12-01

327

For Parents, Teachers and Coaches: About Sports Eye Injury and Protective Eyewear  

Science.gov (United States)

... Parents and coaches play an important role in making sure young athletes protect their eyes and properly gear up for the game. Protective ... includes safety glasses and goggles, safety shields, and eye guards designed for a ... glasses, contact lenses, and sunglasses do not protect against eye ...

328

LASIK eye surgery  

Science.gov (United States)

... scarring or permanent problems with the cornea's shape, making it impossible to wear contact lenses Decrease in contrast sensitivity -- even with 20/20 vision, objects may appear fuzzy or gray Dry eyes Glare or haloes Light sensitivity Night driving problems ...

329

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... your sight depends on it. Give your Eyes a Break To prevent computer eyestrain, follow the 20-20-20 rule: Every ... and benefits of the surgery, how to choose a surgeon and an introduction to the informed consent process. LASIK Surgery: Why ...

330

Eyes for Learning  

Science.gov (United States)

Vision is the dominant sense, and the eyes are connected with almost every other part of the brain. If the vision system is poorly developed, children trying to learn suffer. Without good up close vision, students are handicapped even if no one knows or suspects it--they may not even know it themselves. Students do not know that the way they see…

Orfield, Antonia

2008-01-01

331

Eye Disease and Development  

DEFF Research Database (Denmark)

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.

Andersen, Thomas Barnebeck; Dalgaard, Carl-Johan Lars

2011-01-01

332

Eye Cosmetic Safety  

Science.gov (United States)

... a source of lead poisoning?" Israel Journal of Medical Science, 1992 July; 28(7):417-21. Parry C, Eaton J: Kohl: "A lead-hazardous eye makeup from the Third World to the First World." Environmental Health Perspectives, 1991 Aug; 94:121-3. Page Last Updated: ...

333

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

Science.gov (United States)

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

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

2014-05-01

334

Identification of design features to enhance utilization and acceptance of systems for Internet-based decision support at the point of care.  

OpenAIRE

Extensive utilization of point-of-care decision support systems will be largely dependent on the development of user interaction capabilities that make them effective clinical tools in patient care settings. This research identified critical design features of point-of-care decision support systems that are preferred by physicians, through a multi-method formative evaluation of an evolving prototype of an Internet-based clinical decision support system. Clinicians used four versions of the sy...

Gadd, C. S.; Baskaran, P.; Lobach, D. F.

1998-01-01

335

Eye Bank Association of America  

Science.gov (United States)

... the restoration of sight worldwide. The oldest transplant association in the United States, the EBAA is the ... the practical,... More ? Global Alliance of Eye Bank Associations Scientific Meeting - Register today for Global Alliance Eye ...

336

Disability: recommendations for eye programmes  

Directory of Open Access Journals (Sweden)

Full Text Available In 2012, CBM’s Medical Eye Care Advisory Working Group met in Hyderabad, India to discuss the inclusion of people with disabilities in eye care.As a result of these discussions, recommendations were made.

2013-05-01

337

46 CFR 153.488 - Design and equipment for tanks carrying high melting point NLSs: Category B.  

Science.gov (United States)

...BULK DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID...HAZARDOUS MATERIALS Design and Equipment Design and Equipment for Pollution...Control § 153.488 Design and equipment for tanks...153.491, for a ship to have its...

2010-10-01

338

Pink Eye: What To Do  

Centers for Disease Control (CDC) Podcasts

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.

2010-10-12

339

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 Opening Champagne Bottles ...

340

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’ ...

341

Choosing Wisely When It Comes to Eye Care: Preoperative Testing  

Science.gov (United States)

... Wisely When It Comes to Eye Care Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During ... and Eye Protection Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Opening Champagne Bottles ...

342

Are 3-D Movies Bad for Your Eyes?  

Science.gov (United States)

... 3-D Movies Bad for Your Eyes? Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During ... and Eye Protection Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Opening Champagne Bottles ...

343

Biomedical Devices for the Eyes  

Science.gov (United States)

Students examine the structure and function of the human eye, learning some amazing features about our eyes, which provide us with sight and an understanding of our surroundings. Students also learn about some common eye problems and the biomedical devices and medical procedures that resolve or help to lessen the effects of these vision deficiencies, including vision correction surgery.

Integrated Teaching And Learning Program

344

LIMNOLOGICAL OPTOMETRY: EXAMINING EARTH'S EYE  

Science.gov (United States)

In Thoreau's Walden, a lake is described as the landscape's most expressive feature and the earth's eye. Collectively, scientists are charged by society to assess, monitor, and remedy maladies of earth's eye in the same way optometrists maintain the health of the human eye. This ...

345

Eye-Openers in ASL.  

Science.gov (United States)

This paper summarizes most of what Sign linguists know about the function of the eyes in American Sign Language discourse. Here, "eyes" is taken to cover both opening and closing of the eyes and looking in a particular direction, referred to as the signer's "gaze-direction." Evidence is presented demonstrating that a signer's gaze can be lexically…

Baker, Charlotte

346

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 ...

347

What Is a Comprehensive Dilated Eye Exam?  

Science.gov (United States)

... the Clinical Director Education Programs All Education National Eye Health Education Program Diabetic Eye Disease Education Program Glaucoma ... see Common vision problems Age-Related Eye Diseases Eye Health Tips Podcasts Text Messages Vision-Related Terms, Selected ...

348

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

349

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

Science.gov (United States)

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.

Halik, ?ukasz

2012-11-01

350

Changes in eye protection behavior following an occupational eye injury.  

Science.gov (United States)

This study investigated whether workers modify eye protection behavior following an occupational eye injury. Workers treated for work-related eye injuries were questioned regarding the use of protective eyewear for the work-month prior to their eye injuries and again 6 to 12 months later. Workers reported an increase in the proportion of work-time they used eye protection (from a median of 20% to 100%; p < .0001). The effect appeared to be driven by whether eye protection was used at the time of the injury. Most respondents (66%) indicated they were more likely to use eye protection since their injuries. Workers not using eye protection at the time of injury were more likely to use eye protection in the future. A variety of employer and employee factors may influence this change. Although many workers' behaviors changed, health care providers should embrace the teachable moment when treating occupational eye injuries to encourage continued use or more appropriate forms of eye protection. PMID:22909223

Blackburn, Justin L; Levitan, Emily B; MacLennan, Paul A; Owsley, Cynthia; McGwin, Gerald

2012-09-01

351

Adsorption of a random heteropolymer at a potential well revisited location of transition point and design of sequences  

CERN Document Server

The adsorption of an ideal heteropolymer loop at a potential point well is investigated within the frameworks of a standard random matrix theory. On the basis of semi-analytical/semi-numerical approach the histogram of transition points for the ensemble of quenched heteropolymer structures with bimodal symmetric distribution of types of chain's links is constructed. It is shown that the sequences having the transition points in the tail of the histogram display the correlations between nearest-neighbor monomers.

Naidenov, A

2000-01-01

352

Adsorption of a random heteropolymer at a potential well revisited: location of transition point and design of sequences  

OpenAIRE

The adsorption of an ideal heteropolymer loop at a potential point well is investigated within the frameworks of a standard random matrix theory. On the basis of semi-analytical/semi-numerical approach the histogram of transition points for the ensemble of quenched heteropolymer structures with bimodal symmetric distribution of types of chain's links is constructed. It is shown that the sequences having the transition points in the tail of the histogram display the correlati...

Naidenov, A.; Nechaev, S.

2000-01-01

353

Adsorption of a random heteropolymer at a potential well revisited: location of transition point and design of sequences  

Energy Technology Data Exchange (ETDEWEB)

The adsorption of an ideal heteropolymer loop at a potential point well is investigated within the framework of standard random matrix theory. On the basis of a semi-analytical/semi-numerical approach a histogram of transition points for the ensemble of quenched heteropolymer structures with bimodal symmetric distribution of types of chain links is constructed. It is shown that the sequences having transition points in the tail of the histogram display correlations between nearest-neighbour monomers. (author)

Naidenov, Alexei [L.D. Landau Institute for Theoretical Physics, Moscow (Russian Federation); Nechaev, Sergei [L.D. Landau Institute for Theoretical Physics, Moscow (Russian Federation); UMR 8626, CNRS-Universite Paris XI, LPTMS, Bat.100, Universite Paris Sud, Orsay (France)

2001-07-20

354

Real-time and Offline Filters for Eye Tracking  

OpenAIRE

An eye tracker makes it possible to record the gaze point of a person looking at for example a computer monitor. Modern techniques are very flexible and allow the user to behave naturally without the need of cumbersome equipment such as special contact lenses or electrical probes. This is valuable in psychological research, marketing research and Human Computer Interaction. Eye trackers also give people who are severely paralyzed and unable to type and speak means to communicate using their e...

Olsson, Pontus

2007-01-01

355

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

356

Variable stars magnitudes estimations exploiting the eye physiology  

CERN Document Server

The physiology of the dark adaption process of the eye is revisited from an astronomical point of view. A new method for the magnitude estimation of a star is presented. It is based upon the timing of the physiological cycle of the rhodopsin during the eye dark adaption process. The limits of the application of the method are discussed. This method is suitable for bright stars as Betelgeuse, Antares or Delta Scorpii or stars at the limiting magnitude observed with a telescope.

Sigismondi, Costantino

2011-01-01

357

Keep an eye on the parts:design and implementation of a computerized spare parts inventory control system at Fokker Services  

OpenAIRE

Spare parts inventory control is essential to aircraft service organizations, since excess inventory leads to high holding costs, while insufficient inventory has a great impact on the repair performance. Given factors like demand intermittence, part obsolescence, part interdependency, repair complexity, coupled with high service levels, a detailed assessment was carried out at Fokker Services B.V. Schiphol regarding the current inventory management. The aim of this project was to design and ...

Li, X.

2007-01-01

358

Hyphema Following Eye Trauma  

Directory of Open Access Journals (Sweden)

Full Text Available

Background and Objectives: Hyphema, the blood in the anterior eye chamber, can be caused by penetrating or blunt trauma or other causes. This study aimed at investigating the clinical features of 15 cases of traumatic Hyphema, having referred to ophthalmology ward of Shahid Beheshti hospital of Babol university of medical sciences.

 

Methods: In this study the clinical characteristics of 15 patients with eye trauma-who had referred to Shahid Beheshti Hospital of Babol University of medical sciences during 2008-2009- were examined. In addition to eye trauma the selected patients had microscopic or macroscopic anterior eye chamber hemorrhages.

 

Results: The mean age of patients was 25. 1 years. Eleven patients were male and four were female. Increased IOP was seen in 4 cases, three patients improved with drug therapy, but one patient needed surgery due to an increase in IOP and the re-bleeding. Regarding the degree of Hyphema, 4 cases were microscopic Hyphema , 2 cases were grade 1 of Hyphema, 3 cases were grade 2 of Hyphema, 3 cases were grade 3 of Hyphema , 2 cases grade 4 of Hyphema and one case was not assessable due to flattened anterior chamber, Visual Acuity was mostly poor at the beginning of admission which was significantly improved after treatment. On the whole, six patients underwent surgery.

 

Conclusion: The results of this study show that patients with traumatic Hyphema usually have poor Visual Acuity at the beginning of admission, but the vision was relatively improved with early treatment in many cases. Therefore, proper and timely treatment is necessary in these patients.

E Mikaniki

2012-05-01

359

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.

360

Christoph Scheiner's eye studies.  

Science.gov (United States)

Christoph Scheiner was born in 1573 or 1575. In 1595 he entered into the Order of the Jesuits; he died in 1650. In 1619 his book Oculus, dealing with the optics of the eye, appeared in Innsbruck. The invention of the telescope was of utmost importance for progress in astronomical and physical research. Scheiner himself built telescopes and discovered the sunspots. As a result, an unpleasant priority dispute with Galilei ensued. From 1624 onwards, Scheiner was in Rome, where his main work Rosa Ursina was published in 1630. A part of this book deals with the physiological optics of the eye as well. Some of his discoveries and experiments are taken from these two books: determination of the radius of curvature of the cornea, discovery of the nasal exit of the optic nerve, increase in the radius of curvature of the lens in case of accommodation, Scheiner's procedure (double images with ametropia), refractive indices of various parts of the eye, Scheiner's experiment. Without any doubt, Christoph Scheiner belongs to the foremost scientists of the first half of the 17th century. PMID:1473465

Daxecker, F

1992-01-01

361

Phototherapeutic keratectomy: strategies and results in 12 eyes.  

Science.gov (United States)

As part of a multicenter study of excimer laser procedures, we performed phototherapeutic keratectomy (PTK) on 12 eyes in 11 patients. Three eyes had superficial corneal scarring, two Salzmann's degeneration, two Reis-Bückler's dystrophy; and one each with recurrent lattice dystrophy in a corneal graft, band keratopathy, recurrent erosion syndrome, after pterygium scarring, and contact-lens related keratopathy. Indications for treatment included poor visual acuity, severe glare symptoms, ocular surface discomfort, recurrent erosions, and monocular diplopia. Follow up ranged from 1 to 4 months. Best spectacle corrected visual acuity improved in ten eyes with no eyes suffering loss of best spectacle corrected visual acuity. A hyperopic refractive shift was found in eight of 12 treated eyes. Corneal surface regularity improved in six of 12 eyes and worsened in one eye as measured by computerized corneal topographic analysis. Ten patients (11 eyes) noted improvement in their visual perception and subjective symptoms. We review various strategies of phototherapeutic keratectomy designed to treat particular corneal disorders: patient selection criteria to optimize clinical outcome are reviewed as well. PMID:8499388

Hersh, P S; Spinak, A; Garrana, R; Mayers, M

1993-01-01

362

A push-pull treatment for strengthening the 'lazy eye' in amblyopia.  

Science.gov (United States)

Almost all individuals exhibit sensory eye dominance, one neural basis of which is unequal interocular inhibition. Sensory eye dominance can impair binocular functions that depend on both excitatory and inhibitory mechanisms. We developed a 'push-pull' perceptual learning protocol that simultaneously affects the excitatory and inhibitory networks to reduce sensory eye dominance and improve stereopsis in adults with otherwise normal vision. The push-pull protocol provides a promising clinical paradigm for treating the extreme sensory eye dominance in amblyopia ('lazy eye'). The prevailing standard of care does not directly treat sensory eye dominance; instead, selected excitatory functions in the amblyopic eye are stimulated while the strong eye is patched, on the assumption that recovery of the weak eye's excitatory functions rebalances the eyes. Patching the strong eye does not directly address interocular inhibition; in contrast, the push-pull protocol by design excites the weak eye, while completely inhibiting the strong eye's perception to recalibrate the interocular balance of excitatory and inhibitory interactions. Here, we show that three adult amblyopes who trained on the push-pull protocol gained longstanding improvements in interocular balance and stereopsis. Our findings provide a proof-of-concept and evidence that push-pull learning leads to long-term plasticity. PMID:23618663

Ooi, Teng Leng; Su, Yong R; Natale, Danielle M; He, Zijiang J

2013-04-22

363

ECEM (Eye Closure, Eye Movements): application to depersonalization disorder.  

Science.gov (United States)

Eye Closure, Eye Movements (ECEM) is a hypnotically-based approach to treatment that incorporates eye movements adapted from the Eye Movement Desensitization and Reprocessing (EMDR) protocol in conjunction with hypnosis for the treatment of depersonalization disorder. Depersonalization Disorder has been differentiated from post-traumatic stress disorders and has recently been conceptualized as a subtype of panic disorder (Baker et al., 2003; David, Phillips, Medford, & Sierra, 2004; Segui et. al., 2000). During ECEM, while remaining in a hypnotic state, clients self-generated six to seven trials of eye movements to reduce anticipatory anxiety associated with depersonalization disorder. Eye movements were also used to process triggers that elicited breath holding, often followed by episodes of depersonalization. Hypnotic suggestions were used to reverse core symptoms of depersonalization, subjectively described as "feeling unreal" (Simeon et al., 1997). PMID:19862896

Harriet, E Hollander

2009-10-01

364

The fly's eye camera system  

Science.gov (United States)

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.

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

2014-12-01

365

Causes of eye removal: Analysis of 586 eyes  

OpenAIRE

Background/Aim. Eye enucleation is one of the oldest surgical procedures. The aim of the study was to determine the causes of enucleation as seen in a major reference eye center in Serbia. Methods. Retrospective case series involving a review of all enucleation procedures performed in the period between January 2000 and December 2008 at the Institute for Eye Diseases, Clinical Center of Serbia, Belgrade. The collected information included the basic demographic data and diagnosis of the ...

Kneževi? Miroslav; Paovi? Jelena; Paovi? Predrag; Sredojevi? Vojislav

2013-01-01

366

New eye phantom for ophthalmic surgery  

Science.gov (United States)

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.

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

2014-06-01

367

Visual fatigue versus eye-movements  

Science.gov (United States)

Observing 3D content on a cinema or TV screen potentially generates fatigue. In psychovisual research, experience of visual symptoms following the observation of stereo-content is usually assessed thanks to questionnaires and subjective reports. We attempted to explore the occurrence of visual fatigue using more objective methods, namely by using binocular eye-tracking and psychophysics. A main objective was to study the emergence of visual fatigue in relation with eye-movement knowing the stimulation of the oculomotor system and its response. We designed an experiment in which participants were asked to perform a repeated vergence effort task, just followed by, and interlaced with, a 3D space perception task. Participants' eye movements were recorded during the whole session using an eye-tracking system. The analysis revealed that the perception of 3D shapes was gradually affected by the intensity of the vergence effort task. The effect on stereo-estimation was actually due to visual fatigue. 3D objects and scenes are perceived flatter. Results on the subjective reports of SSQ revealed that oculomotor factors were predominant in the visual symptoms. In addition, some effects and correlations on the micro-saccadic rate were obtained. This work offers a perspective to characterize objectively visual fatigue when watching stereoscopic 3D content.

Vienne, Cyril; Blondé, Laurent; Doyen, Didier

2012-03-01

368

History Through Deaf Eyes  

Science.gov (United States)

Gallaudet University of Washington DC is presenting a travelling exhibition entitled History Through Deaf Eyes. At this Website, readers can learn about the plan, curator, and travel specifics of the exhibition that seeks to place the social history of deaf Americans within the context of better-known aspects of American history and to trace the development of a Deaf identity and language. Contents of the Website are Introduction and Orientation, Formation of Community, An Oral Approach to Education, The War and Post-War Years, Civil Rights Recognition and Access, Information Age, and Choices. Interesting historical photographs accompany the engaging text.

369

Microoptical telescope compound eye  

OpenAIRE

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...

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

2005-01-01

370

Look beyond the red eyes!  

OpenAIRE

This is a case of a 63-year-old gentleman who presented with persistent red eyes to the eye clinic for several months. He had been seen in the eye department on several visits when he was noted to have red ears too. This led to further review in the rheumatology and ear, nose and throat clinic to confirm the diagnosis of relapsing polychondritis. He was treated successfully with systemic steroids.

Kumar, Anupma

2011-01-01

371

Interactive PDF files with embedded 3D designs as support material to study the 32 crystallographic point groups  

Science.gov (United States)

Crystallography and X-ray diffraction techniques are essential topics in geosciences and other solid-state sciences. Their fundamentals, which include point symmetry groups, are taught in the corresponding university courses. In-depth meaningful learning of symmetry concepts is difficult and requires capacity for abstraction and spatial vision. Traditionally, wooden crystallographic models are used as support material. In this paper, we describe a new interactive tool, freely available, inspired in such models. Thirty-two PDF files containing embedded 3D models have been created. Each file illustrates a point symmetry group and can be used to teach/learn essential symmetry concepts and the International Hermann-Mauguin notation of point symmetry groups. Most interactive computer-aided tools devoted to symmetry deal with molecular symmetry and disregard crystal symmetry so we have developed a tool that fills the existing gap.

Arribas, Victor; Casas, Lluís; Estop, Eugènia; Labrador, Manuel

2014-01-01

372

Eye vision system using programmable micro-optics and micro-electronics  

Science.gov (United States)

Proposed is a novel eye vision system that combines the use of advanced micro-optic and microelectronic technologies that includes programmable micro-optic devices, pico-projectors, Radio Frequency (RF) and optical wireless communication and control links, energy harvesting and storage devices and remote wireless energy transfer capabilities. This portable light weight system can measure eye refractive powers, optimize light conditions for the eye under test, conduct color-blindness tests, and implement eye strain relief and eye muscle exercises via time sequenced imaging. Described is the basic design of the proposed system and its first stage system experimental results for vision spherical lens refractive error correction.

Riza, Nabeel A.; Amin, M. Junaid; Riza, Mehdi N.

2014-02-01

373

Are 3-D Movies Bad for Your Eyes?  

Medline Plus

Full Text Available ... for Simple Eye Problems Medical Marijuana for Glaucoma Pregnancy Preventing Eye Injuries Smokers Sports Using Eye Makeup ... Lifestyle Topics Preventing Eye Injuries Healthy Eyes During Pregnancy Computer Usage & Eye Strain Maintaining Your Sight with ...

374

The Human Eye Position Control System in a Rehabilitation Setting  

OpenAIRE

Our work at Ireland’s National Rehabilitation Hospital involves designing communication systems for people suffering from profound physical disabilities. One such system uses the electro-oculogram, which is an (x,y) system of voltages picked up by pairs of electrodes placed, respectively, above and below and on either side of the eyes. The eyeball has a dc polarisation between cornea and back, arising from the photoreceptor rods and cones in the retina. As the eye rotates, the varying volta...

Yvonne Nolan; Edward Burke; Clare Boylan; Annraoi de Paor

2005-01-01

375

Characteristics of eye care practices with managed care contracts  

OpenAIRE

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...

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

2002-01-01

376

Eye movements and their functions in everyday tasks.  

Science.gov (United States)

Human saccades and fixations have numerous functions in complex everyday tasks, which have sometimes been neglected in simple experimental situations. In this review I describe some of the characteristics of eye movement behaviour during real-world interactions with objects, while walking in natural environments and while holding a conversation. When performing real-world actions and walking around the world, we fixate relevant features at critical time points during the task. The eye movements between these fixations are planned and coordinated alongside head and body movements, often occurring a short time before the corresponding action. In social interactions, eye movements are both a mechanism for taking in information (for example, when looking at someone's face or following their gaze) and for signalling one's attention to another person. Thus eye movements are specific to a particular task context and subject to high-level planning and control during everyday actions. PMID:25397783

Foulsham, T

2015-02-01

377

Technical evaluation of the electrical, instrumentation, and control design aspects of the low temperature overpressure protection system for the Point Beach Nuclear Power Plant, Units 1 and 2  

International Nuclear Information System (INIS)

The technical evaluation is presented for the electrical, instrumentation, and control design aspects of the low temperature overpressure protection system for the Point Beach nuclear power plant, Units 1 and 2. Design basis criteria used to evaluate the acceptability of the system included operator action, system testability, single failure criterion, and seismic Category I and IEEE Std-279-1971 criteria. This report is supplied as part of the Selected Electrical, Instrumentation, and Control Systems Issues Support Program being conducted for the U.S. Nuclear Regulatory Commission by Lawrence Livermore Laboratory

378

Operational procedure for computer program for design point characteristics of a compressed-air generator with through-flow combustor for V/STOL applications  

Science.gov (United States)

The computer program described in this report calculates the design-point characteristics of a compressed-air generator for use in V/STOL applications such as systems with a tip-turbine-driven lift fan. The program computes the dimensions and mass, as well as the thermodynamic performance of a model air generator configuration which involves a straight through-flow combustor. Physical and thermodynamic characteristics of the air generator components are also given. The program was written in FORTRAN IV language. Provision has been made so that the program will accept input values in either SI units or U.S. customary units. Each air generator design-point calculation requires about 1.5 seconds of 7094 computer time for execution.

Krebs, R. P.

1971-01-01

379

Optical design of inhomogeneous media to perfectly focus scalar wave fields  

OpenAIRE

A method to design isotropic inhomogeneous refractive index distribution is presented, in which the scalar wave field solutions propagate exactly on an eikonal function (i.e., remaining constant on the Geometrical Optics wavefronts). This method is applied to the design of ¿dipole lenses¿, which perfectly focus a scalar wave field emitted from a point source onto a point absorber, in both two and three dimensions. Also, the Maxwell fish-eye lens in two and three dimensions analyzed.

Benitez Gimenez, Pablo; Min?ano Dominguez, Juan Carlos; Gonzalez Lopez, Juan Carlos

2010-01-01

380

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

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...

Prinya Masawat

2008-01-01

381

Are 3-D Movies Bad for Your Eyes?  

Medline Plus

Full Text Available ... Teenagers Computer Usage Diabetes Diet & Nutrition Eye Injuries Eye Screening Guidelines Home Remedies for Simple Eye Problems Medical Marijuana for Glaucoma Pregnancy Preventing Eye ...

382

Design of a wireless system for patient-hospital communciation and result validation in point of care testing  

OpenAIRE

This paper discuses mobile phone (cell phone) and wireless applications for linking patients who manage their healthcare outside the hospital using Point of Care Testing (POCT) to hospital information systems (HIS). Certain medical conditions require patients to manage their healthcare by performing on themselves POC testing and act faithfully on the result. This raises quality control issue, as these POC samples and testing procedures are not independently overseen by professional hospital s...

Mcgrory, John; Lynch, Owen; Coyle, Eugene

2005-01-01

383

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

OpenAIRE

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 ...

Hu?bner, N. -o; Fleßa, S.; Haak, J.; Wilke, F.; Hu?bner, C.; Dahms, C.; Hoffmann, W.; Kramer, A.

2011-01-01

384

Fly eye radar or micro-radar sensor technology  

Science.gov (United States)

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.

Molchanov, Pavlo; Asmolova, Olga

2014-05-01

385

Simple Solutions for Dry Eye  

Science.gov (United States)

... not like using it. • Sleep is important for maintaining eye comfort. If you are not sleeping well, see ... or want to author a Patient Education Sheet, contact us at sq@sjogrens.org. Patient Education Sheet Simple Solutions for Dry Eye The SSF thanks J. Daniel Nelson, MD, Associate ...

386

Photographic Screening for Eye Defects  

Science.gov (United States)

Images of retinas examined for characteristic patterns. Color photographs of retinas taken. Proper alinement of eye obtained by asking subject to gaze at light-emitting diode. "Red-eye" patterns in resulting color photographs examined by trained observers for signs of ocular defects. System used to check power of contact lenses and eyeglasses by taking photographs with these items in place.

Richardson, J.

1985-01-01

387

Dry eye disease after LASIK  

OpenAIRE

LASIK is a surgical tehnique for the correction of refractive errors (myopia, hyperopia, astygmatism). It results in a reshape of the cornea with ocular surface and especially tear film disease. It is a cause for a iatrogenic dry eye syndrome. Neurogenic and inflamatory theory explain this disease. The main therapy of dry eye is the replacement with artificial tears.

T?uru, L.; Alexandrescu, C.; Stana, D.; Tudosescu, R.

2012-01-01

388

Severe eye injuries in cricket.  

OpenAIRE

We report five cases of severe eye injury sustained in cricket, including retinal detachment and rupture of the globe. The eye is at particular risk from a rising ball. We comment on the need for appropriate facial protection for batsmen and close fielders.

Jones, N. P.; Tullo, A. B.

1986-01-01

389

Eye tracking and gating system for proton therapy of orbital tumors  

Energy Technology Data Exchange (ETDEWEB)

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.

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

390

Semi-automatic evaluation of intraocular lenses (IOL) using a mechanical eye model  

Science.gov (United States)

As cataracts are the most common reason for loss of vision with an age over 55, the implantation of intraocular intraocular lenses is one of the most common surgical interventions. The quality measurement and test instructions for the patients. Therefore more efforts are put into the individualization of IOL in order to achieve better imaging properties. Two examples of typical quality standards for IOL are the modulated transfer function (MTF) and the Strehl ratio which can be measured in vivo or also in mechanical eye models. A mechanical eye model in the scale 1:1 is presented. It has been designed to allow the measurement of the MTF and Strehl ratio and simultaneous evaluation of physiological imaging quality. The eye model allows the automatic analysis of the IOL especially focused on the tolerance for tilting and decentering. Cornea, iris aperture and IOL type are interchangeable, because all these parts are implemented by the use of separated holders. The IOL is mounted on a shift plate. Both are mounted on a tilt plate. This set-up guarantees an independent decentration and tilt of the IOL, both moved by electrical drives. This set-up allows a two-dimensional tolerance analysis of decentration and tilt effects. Different 100×100 point (decentration×tilt) analyzes for various iris apertures, needing only approximately 15 minutes, are presented.

Drauschke, A.; Rank, E.; Forjan, M.; Traxler, L.

2013-03-01

391

Microoptical telescope compound eye.  

Science.gov (United States)

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 masculinex10 masculine field of view and 4.5mm x 0.5mm image size is optimized and analyzed using sequential and non-sequential raytracing and fabricated by microoptics technology. Anamorphic lenses, where the parameters are a function of the considered optical channel, are used to achieve a homogeneous optical performance over the whole field of view. Captured images are presented and compared to simulation results. PMID:19494951

Duparré, Jacques; Schreiber, Peter; Matthes, André; Pshenay-Severin, Ekaterina; Bräuer, Andreas; Tünnermann, Andreas; Völkel, Reinhard; Eisner, Martin; Scharf, Toralf

2005-02-01

392

Gray Eye Traffic Surveillance  

Directory of Open Access Journals (Sweden)

Full Text Available Gray Eye Traffic Surveillance (GETS is a system based on image processing technology and database processing for the purpose of Traffic Surveillance. This system is built specifically for India, where standard fonts and scripts for the number plates are rarely followed and corruption is a menace.This paper attempts to present a system to automate the entire process of traffic surveillance and curb corruption at the same time. A two way approach of developing a desktop and a web based mobile application is proposed. The desktop based application uses image processing technology to recognize the license number from image of vehicles captured by surveillance cameras and maintain a track log. The web based mobile application can be used by authorized traffic police to file complaints. The general public can log into this application to view their log and file complaints in case of any discrepancies. Different database schemas are used for various purpose like authentication, crime details, tracking system.

Ayesha Butalia #1, Durgesh Maru*2, Kuldeep Baheti*3, Avais Mohammad*4, Ankit Bagdiya*5

2011-06-01

393

Design and Study on Sliding Mode Extremum Seeking Control of the Chaos Embedded Particle Swarm Optimization for Maximum Power Point Tracking in Wind Power Systems  

Directory of Open Access Journals (Sweden)

Full Text Available This paper proposes a sliding mode extremum seeking control (SMESC of chaos embedded particle swarm optimization (CEPSO Algorithm, applied to the design of maximum power point tracking in wind power systems. Its features are that the control parameters in SMESC are optimized by CEPSO, making it unnecessary to change the output power of different wind turbines, the designed in-repetition rate is reduced, and the system control efficiency is increased. The wind power system control is designed by simulation, in comparison with the traditional wind power control method, and the simulated dynamic response obtained by the SMESC algorithm proposed in this paper is better than the traditional hill-climbing search (HCS and extremum seeking control (ESC algorithms in the transient or steady states, validating the advantages and practicability of the method proposed in this paper.

Jui-Ho Chen

2014-03-01

394

Case study: improving the management of eye care programmes  

Directory of Open Access Journals (Sweden)

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.

Kolawole Olumide Ogundimu

2008-12-01

395

Sun, UV Radiation and Your Eyes  

Science.gov (United States)

... Eye) Astigmatism Bacterial Keratitis Bell's Palsy Blepharitis Cataracts Contact Lens-Related Infections Detached & Torn Retina Diabetic Retinopathy Dry Eye Floaters & Flashes Glaucoma Hyperopia (Farsightedness) Low Vision ...

396

Minority Eye Health: Know Your Risks  

Science.gov (United States)

... Eye) Astigmatism Bacterial Keratitis Bell's Palsy Blepharitis Cataracts Contact Lens-Related Infections Detached & Torn Retina Diabetic Retinopathy Dry Eye Floaters & Flashes Glaucoma Hyperopia (Farsightedness) Low Vision ...

397

Perfect drain for the Maxwell fish eye lens  

International Nuclear Information System (INIS)

Perfect imaging of electromagnetic waves using the Maxwell fish eye (MFE) requires a new concept: a point called the perfect drain that we shall call the perfect point drain. From the mathematical point of view, a perfect point drain is just like an ideal point source, except that it drains power from the electromagnetic field instead of generating it. We introduce here the perfect drain for the MFE as a dissipative region of non-zero size that completely drains the power from the point source. To accomplish this goal, the region must have a precise complex permittivity that depends on its size as well as on the frequency. The perfect point drain is obtained when the diameter of the perfect drain tends to zero. This interpretation of the perfect point drain is connected well with common concepts of electromagnetic theory, opening up both modeling in computer simulations and experimental verification of setups containing a perfect point drain.

398

Perfect drain for the Maxwell fish eye lens  

Energy Technology Data Exchange (ETDEWEB)

Perfect imaging of electromagnetic waves using the Maxwell fish eye (MFE) requires a new concept: a point called the perfect drain that we shall call the perfect point drain. From the mathematical point of view, a perfect point drain is just like an ideal point source, except that it drains power from the electromagnetic field instead of generating it. We introduce here the perfect drain for the MFE as a dissipative region of non-zero size that completely drains the power from the point source. To accomplish this goal, the region must have a precise complex permittivity that depends on its size as well as on the frequency. The perfect point drain is obtained when the diameter of the perfect drain tends to zero. This interpretation of the perfect point drain is connected well with common concepts of electromagnetic theory, opening up both modeling in computer simulations and experimental verification of setups containing a perfect point drain.

Gonzalez, Juan C; BenItez, Pablo; Minano, Juan C, E-mail: jcgonzalez@cedint.upm.es [Universidad Politecnca de Madrid, Cedint Campus de Montegancedo, 28223 Madrid (Spain)

2011-02-15

399

Combined Approaches for Drug Design Points the Way to Novel Proline Racemase Inhibitor Candidates to Fight Chagas’ Disease  

OpenAIRE

Chagas' disease is caused by Trypanosoma cruzi, a protozoan transmitted to humans by blood-feeding insects, blood transfusion or congenitally. Previous research led us to discover a parasite proline racemase (TcPRAC) and to establish its validity as a target for the design of new chemotherapies against the disease, including its chronic form. A known inhibitor of proline racemases, 2-pyrrolecarboxylic acid (PYC), is water-insoluble. We synthesized soluble pyrazole derivatives, but they proved...

Berneman, Armand; Montout, Lory; Goyard, Sophie; Chamond, Nathalie; Cosson, Alain; D Archivio, Simon; Gouault, Nicolas; Uriac, Philippe; Blondel, Arnaud; Minoprio, Paola

2013-01-01

400

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

Directory of Open Access Journals (Sweden)

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.

Hübner, N.-O.

2011-01-01

401

Robust stability analysis and dynamic gain-scheduled controller design for point time-delay systems with parametrical uncertainties  

Science.gov (United States)

This paper discusses linear fractional representations (LFR) of parameter-dependent nonlinear systems with real-rational nonlinearities and point-delayed dynamics. Sufficient conditions for robust global asymptotic stability independent of the delays and the existence of a robust stabilizing gain-scheduled dynamic controller are investigated via linear matrix inequalities. Such inequalities are obtained from the values of the time-derivatives of appropriate Lyapunov functions at all the vertices of the polytope which contains the parametrized uncertainties. The synthesized stabilizing controller consists of an interpolation being performed with the stabilizing controllers at the set of vertices of a certain polytope where the nonlinear-rational parametrization belongs to. Some extensions are also given concerning robust global asymptotic stability dependent of the delays. Numerical examples corroborate the usefulness of the proposed formalism and its applicability to practical related problems.

De la Sen, M.

2008-08-01

402

Eye-safe lidar system for pesticide spray drift measurement.  

Science.gov (United States)

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

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

2015-01-01

403

Design of free-space optical interconnects using two Gabor superlenses  

Science.gov (United States)

We propose a novel design of micro-optical devices based on multi-aperture compound insect eyes, which transfer a point-to-point multichannel free space signal combined with a diffraction grating. The system is inspired in the refractive superposition compound eyes configuration known as Gabor superlens (GSL) using microlens arrays. A switching function and wave division multiplexing are achieved by introducing a diffraction grating placed in the global focus of the system. The source characteristics, either coherent or incoherent, influence the device performance.

Garza-Rivera, Anel; Renero-Carrillo, Francisco-Javier; Trevino-Palacios, Carlos-G.

2014-09-01

404

The High Resolution Fly's Eye Project  

Science.gov (United States)

The High Resolution Fly's Eye (HiRes) is under construction at Dugway, Utah. It measures the longitudinal development profiles of cosmic ray air showers by means of atmospheric scintillation light which is produced in proportion to the number of shower particles at each atmospheric depth. The new detector has greater sensitivity and higher resolution than the former Utah Fly's Eye because its mirrors collect 2.3 times as much light, the pixel solid angle has been reduced by 1/25, and signals will be measured with flash ADC electronics. A 14-mirror prototype has operated for 3 years, measuring air showers in coincidence with the CASA/MIA detector arrays and also with the Fly'e Eye II detector. HiRes is designed to measure extremely high energy cosmic ray air showers stereoscopically, and a set of such stereo events has been collected during the past year using a second prototype of 4 mirror units located at a distance of 12.6 km from the 14-mirror prototype. Laser pulses and vertical flashers have proved useful for evaluating the detector's performance and for studying the variability of atmospheric aerosol concentrations. The HiRes collaboration includes the University of Adelaide, Columbia University, the University of Illinois, and the University of Utah.

Sommers, Paul

1996-05-01

405

Analysing the spatial dimension of eye movement data using a visual analytic approach  

OpenAIRE

Conventional analyses on eye movement data only take into account eye movement metrics, such as the number or the duration of fixations and length of the scanpaths, on which statistical analysis is performed for detecting significant differences. However, the spatial dimension in the eye movements is neglected, which is an essential element when investigating the design of maps. The study described in this paper uses a visual analytics software package, the Visual Analytics Toolkit, to analys...

Ooms, K.; Andrienko, Gennady; Andrienko, N.; Maeyer, P.; Fack, V.

2012-01-01

406

Educating Older African Americans about the Preventive Importance of Routine Comprehensive Eye Care  

OpenAIRE

Older African Americans have higher rates of vision impairment lower utilization rates of comprehensive eye care, compared to whites. InCHARGE© is an eye health education program for this population that promotes prevention through the annual, dilated comprehensive eye examination. This study, using a pre/post design, evaluated whether InCHARGE imparted knowledge about prevention and strategies for reducing barriers to care. The program was presented to 85 older African Americans in 5 senior...

Owsley, Cynthia; Mcgwin, Gerald; Stalvey, Beth T.; Weston, June; Searcey, Karen; Girkin, Christopher A.

2008-01-01

407

Protocol for the combined immunosuppression & radiotherapy in thyroid eye disease (CIRTED trial: A multi-centre, double-masked, factorial randomised controlled trial  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Medical management of thyroid eye disease remains controversial due to a paucity of high quality evidence on long-term treatment outcomes. Glucocorticoids are known to be effective initially but have significant side-effects with long-term use and recrudescence can occur on cessation. Current evidence is conflicting on the efficacy of radiotherapy and non-steroid systemic immunosuppression, and the majority of previous studies have been retrospective, uncontrolled, small or poorly designed. The Combined Immunosuppression and Radiotherapy in Thyroid Eye Disease (CIRTED trial was designed to investigate the efficacy of radiotherapy and azathioprine in combination with a standard course of oral prednisolone in patients with active thyroid eye disease. Methods/design Patients with active thyroid eye disease will be randomised to receive (i azathioprine or oral placebo and (ii radiotherapy or sham-radiotherapy in this multi-centre, factorial randomised control trial. The primary outcome is improvement in disease severity (assessed using a composite binary measure at 12 months and secondary end-points include quality of life scores and health economic measures. Discussion The CIRTED trial is the first study to evaluate the role of radiotherapy and azathioprine as part of a long-term, combination immunosuppressive treatment regime for Thyroid Eye Disease. It will provide evidence for the role of radiotherapy and prolonged immunosuppression in the management of this condition, as well as pilot data on their use in combination. We have paid particular attention in the trial design to establishing (a robust placebo controls and masking protocols which are effective and safe for both radiotherapy and the systemic administration of an antiproliferative drug; (b constructing effective inclusion and exclusion criteria to select for active disease; and (c selecting pragmatic outcome measures. Trial registration Current controlled trials ISRCTN22471573

Kingston Laura

2008-01-01

408

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

409

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

Science.gov (United States)

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

Barbosa, Catia; Tao Dong

2014-08-01

410

Immune privilege persists in eyes with extreme inflammation induced by intravitreal LPS.  

Science.gov (United States)

Since immune privilege is believed to exist in the eye in order to suppress sight-destroying inflammation, we wondered whether eyes with intraocular inflammation retain the immune privileged state. Intraocular inflammation was induced by injection of lipopolysaccharide (LPS) into the vitreous cavity of BALB/c mouse eyes, which showed a peak in intensity at approximately 9 h. At this time point, inflamed eyes were examined for their capacity to afford immune privilege to injected allogeneic tumor cells, and to promote anterior chamber-associated immune deviation (ACAID) to antigens injected locally. In addition, aqueous humor (AqH) harvested from inflamed eyes was tested for its ability to suppress T cell activation. Surprisingly, eyes with acute, intense intraocular inflammation allowed allogeneic tumor cells to form progressively growing tumors, and these same eyes promoted ACAID. Moreover, AqH harvested from inflamed eyes strongly inhibited T cell activation. We conclude that the type of extreme, intraocular inflammation evoked by intravitreally injected LPS fails to abolish immune privilege in the eye. These findings are discussed in light of the effects of other types of inflammation on the integrity of ocular immune privilege, and with respect to the capacity of the eye to maintain immune privilege by more than one mechanism. PMID:11745402

Mo, J S; Streilein, J W

2001-12-01

411

The interblink interval in normal and dry eye subjects  

Directory of Open Access Journals (Sweden)

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

Johnston PR

2013-02-01

412

Building the eye care team  

OpenAIRE

Eye care services are people intensive. They require the right people (competence), in the right numbers (capacity), in the right mix (team) with the right resources and processes (enabling conditions) to ensure effective and sustainable delivery of patient care.

Thulasiraj Ravilla; Gnanasekaran Chinnathambi

2014-01-01

413

Eye Movements When Viewing Advertisements  

Directory of Open Access Journals (Sweden)

Full Text Available In this selective review, we examine key findings on eye movements when viewing advertisements. We begin with a brief, general introduction to the properties and neural underpinnings of saccadic eye movements. Next, we provide an overview of eye movement behavior during reading, scene perception, and visual search, since each of these activities is, at various times, involved in viewing ads. We then review the literature on eye movements when viewing print ads and warning labels (of the kind that appear on alcohol and tobacco ads, before turning to a consideration of advertisements in dynamic media (television and the Internet. Finally, we propose topics and methodological approaches that may prove to be useful in future research.

EmilyHiggins

2014-03-01

414

Eye movements when viewing advertisements.  

Science.gov (United States)

In this selective review, we examine key findings on eye movements when viewing advertisements. We begin with a brief, general introduction to the properties and neural underpinnings of saccadic eye movements. Next, we provide an overview of eye movement behavior during reading, scene perception, and visual search, since each of these activities is, at various times, involved in viewing ads. We then review the literature on eye movements when viewing print ads and warning labels (of the kind that appear on alcohol and tobacco ads), before turning to a consideration of advertisements in dynamic media (television and the Internet). Finally, we propose topics and methodological approaches that may prove to be useful in future research. PMID:24672500

Higgins, Emily; Leinenger, Mallorie; Rayner, Keith

2014-01-01

415

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, ...

416

Chemical Injury to the Eye  

Science.gov (United States)

... can be damaged by solid, liquid, powder or aerosol chemicals. Chemical injuries that happen in the home ... will be put into your eye to prevent infection, and a topical steroid may be used to ...

417

Post-LASIK dry eye  

OpenAIRE

Laser-assisted in situ keratomileusis (LASIK) is a frequently performed corneal refractive surgery with excellent refractive outcomes. The most common complication of LASIK is dry eyes, with virtually all patients developing some degree of dryness in the immediate postoperative period. Identifying preoperative dry eyes, and conscientious attention and treatment in the perioperative time period, can lead to enhanced patient satisfaction and more accurate visual outcomes. Improved understanding...

Shtein, Roni M.

2011-01-01

418

Increased drift in amblyopic eyes.  

OpenAIRE

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....

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

1980-01-01

419

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 ...

420

Are 3-D Movies Bad for Your Eyes?  

Medline Plus

Full Text Available ... Eyes & the Sun Eye Health News Consumer Alerts Are 3-D Movies Bad for Your Eyes? Tweet ... eye care provider for your condition or treatment. Are You Fit at 40? A baseline eye exam ...

421

Are 3-D Movies Bad for Your Eyes?  

Medline Plus

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

422

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 ...

423

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 ...

424

The eye and the heart.  

Science.gov (United States)

The vasculature of the eye and the heart share several common characteristics. The easily accessible vessels of the eye are therefore-to some extent-a window to the heart. There is interplay between cardiovascular functions and risk factors and the occurrence and progression of many eye diseases. In particular, arteriovenous nipping, narrowing of retinal arteries, and the dilatation of retinal veins are important signs of increased cardiovascular risk. The pressure in the dilated veins is often markedly increased due to a dysregulation of venous outflow from the eye. Besides such morphological criteria, functional alterations might be even more relevant and may play an important role in future diagnostics. Via neurovascular coupling, flickering light dilates capillaries and small arterioles, thus inducing endothelium-dependent, flow-mediated dilation of larger retinal vessels. Risk factors for arteriosclerosis, such as dyslipidaemia, diabetes, or systemic hypertension, are also risk factors for eye diseases such as retinal arterial or retinal vein occlusions, cataracts, age-related macular degeneration, and increases in intraocular pressure (IOP). Functional alterations of blood flow are particularly relevant to the eye. The primary vascular dysregulation syndrome (PVD), which often includes systemic hypotension, is associated with disturbed autoregulation of ocular blood flow (OBF). Fluctuation of IOP on a high level or blood pressure on a low level leads to instable OBF and oxygen supply and therefore to oxidative stress, which is particularly involved in the pathogenesis of glaucomatous neuropathy. Vascular dysregulation also leads to a barrier dysfunction and thereby to small retinal haemorrhages. PMID:23401492

Flammer, Josef; Konieczka, Katarzyna; Bruno, Rosa M; Virdis, Agostino; Flammer, Andreas J; Taddei, Stefano

2013-05-01

425

Eye-based head gestures for interaction in the car  

DEFF Research Database (Denmark)

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.

Mardanbeigi, Diako; Witzner Hansen, Dan

426

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

Science.gov (United States)

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. PMID:25176973

Menis, Jessica; Hasan, Baktiar; Besse, Benjamin

2014-09-01

427

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)

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.

Jessica Menis

2014-09-01

428

Building core capacities at the designated points of entry according to the International Health Regulations 2005: a review of the progress and prospects in Taiwan  

Directory of Open Access Journals (Sweden)

Full Text Available Background: As designated points of entry (PoEs play a critical role in preventing the transmission of international public health risks, huge efforts have been invested in Taiwan to improve the core capacities specified in the International Health Regulations 2005 (IHR 2005. This article reviews how Taiwan strengthened the core capacities at the Taoyuan International Airport (TIA and the Port of Kaohsiung (PoK by applying a new, practicable model. Design: An IHR PoE program was initiated for implementing the IHR core capacities at designated PoEs. The main methods of this program were 1 identifying the designated PoEs according to the pre-determined criteria, 2 identifying the competent authority for each health measure, 3 building a close collaborative relationship between stakeholders from the central and PoE level, 4 designing three stages of systematic assessment using the assessment tool published by the World Health Organization (WHO, and 5 undertaking action plans targeting the gaps identified by the assessments. Results: Results of the self-assessment, preliminary external assessment, and follow-up external assessment revealed a continuous progressive trend at the TIA (86, 91, and 100%, respectively, and at the PoK (77, 97, and 99.9%, respectively. The results of the follow-up external assessment indicated that both these designated PoEs already conformed to the IHR requirements. These achievements were highly associated with strong collaboration, continuous empowerment, efficient resource integration, and sustained commitments. Conclusions: Considering that many countries had requested for an extension on the deadline to fulfill the IHR 2005 core capacity requirements, Taiwan's experiences can be a source of learning for countries striving to fully implement these requirements. Further, in order to broaden the scope of public health protection into promoting global security, Taiwan will keep its commitments on multisectoral cooperation, human resource capacity building, and maintaining routine and emergency capacities.

Hsiao-Hsuan Chiu

2014-07-01

429

Integrated modeling of steel refining, casting and rolling operations to obtain design set points for quality steel sheet production  

Science.gov (United States)

Non-metallic inclusions are defects present in steel which disrupt the homogeneity of structure and adversely affects the mechanical properties. To some extent silo approach based mathematical models have been successfully used to modify and control inclusions in steel making but very few attempts have been made to deal with these processes in integrated framework. With computational advancement and high promising potential of ICME (Integrated Computational Materials Engineering), physics based models can be integrated which will lead to overall increase of process understanding, control and eventually to better properties and performance of material. The objectives of the present work are: (a) using CFD based models understand the influence of various design and process parameters on inclusion removal during secondary steel making, (b) using FEM model study the effects of type and characteristics of inclusions during solid state forming operations, and finally (c) integrate these models in order to develop an integrated modeling framework. This integrated framework will determine the extent up to which inclusions can be tolerated in downstream processes without affecting the quality and properties of final steel sheet significantly and suggest modifications in upstream processes if inclusions are above acceptable limit.

Gupta, Akash; Kumar, Prabhash; Anapagaddi, Ravikiran; Reddy, Niranjan; Goyal, Sharad; Singh, A. K.; Padmanabhan, K. A.

2013-05-01

430

Model-Based Eye Detection and Animation  

OpenAIRE

In this thesis we present a system to extract the eye motion from a video stream containing a human face and applying this eye motion into a virtual character. By the notation eye motion estimation, we mean the information which describes the location of the eyes in each frame of the video stream. Applying this eye motion estimation into a virtual character, we achieve that the virtual face moves the eyes in the same way than the human face, synthesizing eye motion into a virtual character. I...

Trejo Guerrero, Sandra

2006-01-01

431

Can Maxwell's fish eye lens really give perfect imaging?  

CERN Document Server

Both explicit analysis and FEM numerical simulation are used to analyze the field distribution of a line current in the so-called Maxwell's fish eye lens [bounded with a perfectly electrical conductor (PEC) boundary]. We show that such a 2D Maxwell's fish eye lens cannot give perfect imaging due to the fact that high order modes of the object field can hardly reach the image point in Maxwell's fish eye lens. If only zeroth order mode is excited, a good image of a sharp object may be achieved in some cases, however, its spot-size is larger than the spot size of the initial object field. The image resolution is determined by the field spot size of the image corresponding to the zeroth order component of the object field. Our explicit analysis consists very well with the FEM results for a fish eye lens. Time-domain simulation is also given to verify our conclusion. Multi-point images for a single object point are also demonstrated.

Sun, Fei

2010-01-01

432

On subwavelength imaging with Maxwell's fish eye lens  

CERN Document Server

Both explicit analysis and FEM numerical simulation are used to analyze the field distribution of a line current in the so-called Maxwell's fish eye lens [bounded with a perfectly electrical conductor (PEC) boundary]. We show that such a 2D Maxwell's fish eye lens cannot give perfect imaging due to the fact that high order modes of the object field can hardly reach the image point in Maxwell's fish eye lens. If only zeroth order mode is excited, a subwavelength image of a sharp object may be achieved in some cases, however, its spot-size is larger than the spot size of the initial object field. The image resolution is determined by the field spot size of the image corresponding to the zeroth order component of the object field. Our explicit analysis consists very well with the FEM results for a fish eye lens. Time-domain simulation is also given to verify our conclusion. Multi-point imaging for a single object point is also demonstrated.

Sun, Fei

2010-01-01

433

Moth's eye anti-reflection gratings on germanium freeform surfaces  

Science.gov (United States)

Germanium is commonly used for optical components in the infrared, but the high refractive index of germanium causes significant losses due to Fresnel reflections. Anti-reflection (AR) surfaces based on subwavelength "moth's eye" gratings provide one means to significantly increase optical transmission. As found in nature, these gratings are conformal to the curved surfaces of lenslets in the eye of the moth. Engineered optical systems inspired by biological examples offer possibilities for increased performance and system miniaturization, but also introduce significant challenges to both design and fabrication. In this paper, we consider the design and fabrication of conformal moth's eye AR structures on germanium freeform optical surfaces, including lens arrays and Alvarez lenses. Fabrication approaches and limitations based on both lithography and multi-axis diamond machining are considered. Rigorous simulations of grating performance and approaches for simulation of conformal, multi-scale optical systems are discussed.

Liu, Meng; Shultz, Jason A.; Owen, Joseph D.; Davies, Matthew A.; Suleski, Thomas J.

2014-09-01

434

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

DEFF Research Database (Denmark)

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.

Pietroni, C.; Andersen, J.D.

2013-01-01

435

Eye Detection System using Orientation Histogram  

OpenAIRE

Face alignment is an important issue in face recognition systems. The performance of the face recognition system depends on the accuracy of face alignment. Since face alignment is usually conducted using eye positions, an accurate eye localization algorithm is essential for accurate face recognition. In many applications like eye-gaze tracking, iris detection for security system, the eye detection is also necessitated. In this paper, we propose a new eye detection system which can accurately ...

Nwe Ni San, Nyein Aye

2013-01-01

436

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

Directory of Open Access Journals (Sweden)

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.

Nagpal Manish

2003-01-01

437

Cell-based model of the Limulus lateral eye.  

Science.gov (United States)

We present a cell-based model of the Limulus lateral eye that computes the eye's input to the brain in response to any specified scene. Based on the results of extensive physiological studies, the model simulates the optical sampling of visual space by the array of retinal receptors (ommatidia), the transduction of light into receptor potentials, the integration of excitatory and inhibitory signals into generator potentials, and the conversion of generator potentials into trains of optic nerve impulses. By simulating these processes at the cellular level, model ommatidia can reproduce response variability resulting from noise inherent in the stimulus and the eye itself, and they can adapt to changes in light intensity over a wide operating range. Programmed with these realistic properties, the model eye computes the simultaneous activity of its ensemble of optic nerve fibers, allowing us to explore the retinal code that mediates the visually guided behavior of the animal in its natural habitat. We assess the accuracy of model predictions by comparing the response recorded from a single optic nerve fiber to that computed by the model for the corresponding receptor. Correlation coefficients between recorded and computed responses were typically >95% under laboratory conditions. Parametric analyses of the model together with optic nerve recordings show that animal-to-animal variation in the optical and neural properties of the eye do not alter significantly its response to objects having the size and speed of horseshoe crabs. The eye appears robustly designed for encoding behaviorally important visual stimuli. Simulations with the cell-based model provide insights about the design of the Limulus eye and its encoding of the animal's visual world. PMID:9772240

Passaglia, C L; Dodge, F A; Barlow, R B

1998-10-01

438

Eye movements reset visual perception.  

Science.gov (United States)

Human vision uses saccadic eye movements to rapidly shift the sensitive foveal portion of our retina to objects of interest. For vision to function properly amidst these ballistic eye movements, a mechanism is needed to extract discrete percepts on each fixation from the continuous stream of neural activity that spans fixations. The speed of visual parsing is crucial because human behaviors ranging from reading to driving to sports rely on rapid visual analysis. We find that a brain signal associated with moving the eyes appears to play a role in resetting visual analysis on each fixation, a process that may aid in parsing the neural signal. We quantified the degree to which the perception of tilt is influenced by the tilt of a stimulus on a preceding fixation. Two key conditions were compared, one in which a saccade moved the eyes from one stimulus to the next and a second simulated saccade condition in which the stimuli moved in the same manner but the subjects did not move their eyes. We find that there is a brief period of time at the start of each fixation during which the tilt of the previous stimulus influences perception (in a direction opposite to the tilt aftereffect)--perception is not instantaneously reset when a fixation starts. Importantly, the results show that this perceptual bias is much greater, with nearly identical visual input, when saccades are simulated. This finding suggests that, in real-saccade conditions, some signal related to the eye movement may be involved in the reset phenomenon. While proprioceptive information from the extraocular muscles is conceivably a factor, the fast speed of the effect we observe suggests that a more likely mechanism is a corollary discharge signal associated with eye movement. PMID:23241264

Paradiso, Michael A; Meshi, Dar; Pisarcik, Jordan; Levine, Samuel

2012-01-01

439

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)

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.

Nathália de, Paula; Celso Carlos, Novaes.

2010-12-01

440

Evaluation of Corneal Deformation Analyzed with Scheimpflug Based Device in Healthy Eyes and Diseased Ones  

Science.gov (United States)

This study was designed to evaluate the correlation between corneal biomechanical and morphological data in healthy eyes, eyes that underwent myopic photorefractive keratectomy (PRK), keratoconus affected eyes, and keratoconus affected eyes that underwent corneal collagen crosslinking (CCC). Complete clinical eye examination of all eyes was followed by tomographic (Pentacam, Oculus, Wetzlar, Germany) and biomechanical (Corvis ST, Oculus, Wetzlar, Germany) evaluation. Differences among Corvis ST (CST) parameters in the different groups have been performed. Linear regression between central corneal thickness (CCT), intraocular pressure (IOP), and anterior corneal curvature measured with Sim'K (KM), versus corneal deformation parameters measured with Corvis ST in the different groups, has been run using SPSS software version 18.0. We evaluated 64 healthy eyes of 64 patients with a mean refractive error of ?0.65 ± 1.68?D (measured as spherical equivalent), 17 eyes of 17 patients that underwent myopic PRK for a mean refractive defect of ?4.91 ± 2.05?D (measured as spherical equivalent), 16 eyes of 16 patients affected by keratconus (stage 2-3 of Amsler Classification), and 13 eyes of 13 patients affected by keratoconus that underwent CCC. Our data suggest that corneal curvature would have a greater influence on corneal deformation than CCT; in fact KM values are more strongly associated with more CST parameters both about corneal change in shape and both about the corneal ability to come back at original shape. PMID:25054144

Lanza, Michele; Cennamo, Michela; Iaccarino, Stefania; Irregolare, Carlo; Bifani, Mario; Gironi Carnevale, Ugo Antonello

2014-01-01

441

Ultraviolet radiation and the anterior eye.  

Science.gov (United States)

The eye is on the one hand dependent on visible light energy and on the other hand can be damaged by these and the contiguous ultraviolet (UV) and infrared wavelengths. Diseases of the eye in which sunlight has been implicated have been termed the ophthalmohelioses, and these conditions pose a significant problem to the eye health of many communities. The ophthalmohelioses have a tremendous impact on patients' quality of life and have significant implications on the cost of health care. Although cataract is not entirely caused by insolation, it now seems certain that sunlight plays a contributory role-cataract extraction is one of the, if not the most, commonly performed surgical procedures in many societies. Pterygium, typically afflicting a younger population, adds a tremendous burden, both human and financial, in many countries. We review evidence that peripheral light focusing by the anterior eye to the sites of usual locations of pterygium and cataract plays a role in the pathogenesis of these conditions. Recognition of the light pathways involved with foci at stem cell niches has directed our investigations into inflammatory and matrix metalloproteinase-related pathophysiologic mechanisms. An understanding of the intracellular mechanisms involved has provided some insight into how medical treatments have been developed for the effective management of ocular surface squamous neoplasia. The concept of peripheral light focusing has also provided direction in the prevention of these diseases. This has resulted in improved sunglass design and the further development of UV-blocking contact lenses. With the development of ocular UV fluorescence photographic techniques, we have been able to demonstrate preclinical ocular surface evidence of solar damage. Evidence that diet may play a role in the development of certain conditions is reviewed. The conundrum of the public health message about solar exposure is also reviewed, and in this context, the potential role of vitamin D deficiency is summarized. The eye may play a role in the development of individualized assessment techniques of solar damage, perhaps allowing us to provide better advice to both individuals and populations. PMID:21670690

Coroneo, Minas

2011-07-01

442

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

443

Monitoring the eye lens: which dose quantity is adequate?  

Science.gov (United States)

Recent epidemiological studies suggest a rather low dose threshold (below 0.5 Gy) for the induction of a cataract of the eye lens. Some other studies even assume that there is no threshold at all. Therefore, protection measures have to be optimized and current dose limits for the eye lens may be reduced in the future. The question of which personal dose equivalent quantity is appropriate for monitoring the dose to the eye lens arises from this situation. While in many countries dosemeters calibrated in terms of the dose equivalent quantity Hp(0.07) have been seen as being adequate for monitoring the dose to the eye lens, this might be questionable in the case of reduced dose limits and, thus, it may become necessary to use the dose equivalent quantity Hp(3) for this purpose. To discuss this question, the dose conversion coefficients for the equivalent dose of the eye lens (in the following eye lens dose) were determined for realistic photon and beta radiation fields and compared with the values of the corresponding conversion coefficients for the different operational quantities. The values obtained lead to the following conclusions: in radiation fields where most of the dose comes from photons, especially x-rays, it is appropriate to use dosemeters calibrated in terms of Hp(0.07) on a slab phantom, while in other radiation fields (dominated by beta radiation or unknown contributions of photon and beta radiation) dosemeters calibrated in terms of Hp(3) on a slab phantom should be used. As an alternative, dosemeters calibrated in terms of Hp(0.07) on a slab phantom could also be used; however, in radiation fields containing beta radiation with the end point energy near 1 MeV, an overestimation of the eye lens dose by up to a factor of 550 is possible.

Behrens, R.; Dietze, G.

2010-07-01

444

Nutrients for the aging eye  

Directory of Open Access Journals (Sweden)

Full Text Available Helen M Rasmussen,1 Elizabeth J Johnson2 1Educational Studies, Lesley University, Cambridge, MA, USA; 2Carotenoid and Health Laboratory, Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA, USA Abstract: The incidence of age-related eye diseases is expected to rise with the aging of the population. Oxidation and inflammation are implicated in the etiology of these diseases. There is evidence that dietary antioxidants and anti-inflammatories may provide benefit in decreasing the risk of age-related eye disease. Nutrients of interest are vitamins C and E, ?-carotene, zinc, lutein, zeaxanthin, and the omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid. While a recent survey finds that among the baby boomers (45–65 years old, vision is the most important of the five senses, well over half of those surveyed were not aware of the important nutrients that play a key role in eye health. This is evident from a national survey that finds that intake of these key nutrients from dietary sources is below the recommendations or guidelines. Therefore, it is important to educate this population and to create an awareness of the nutrients and foods of particular interest in the prevention of age-related eye disease. Keywords: nutrition, aging, eye health

Rasmussen HM

2013-06-01

445

Videos from the National Eye Institute: Eye Diseases | NIH MedlinePlus the Magazine  

Science.gov (United States)

... this page please turn Javascript on. Feature: Vision Videos from the National Eye Institute: Eye Diseases Past ... the early detection of eye disease. Share these videos with friends, family and colleagues. www.nei.nih. ...

446

Eye position effects in saccadic adaptation in macaque monkeys.  

Science.gov (United States)

The saccadic amplitude of humans and monkeys can be adapted using intrasaccadic target steps in the McLaughlin paradigm. It is generally believed that, as a result of a purely retinal reference frame, after adaptation of a saccade of a certain amplitude and direction, saccades of the same amplitude and direction are all adapted to the same extent, independently from the initial eye position. However, recent studies in humans have put the pure retinal coding in doubt by revealing that the initial eye position has an effect on the transfer of adaptation to saccades of different starting points. Since humans and monkeys show some species differences in adaptation, we tested the eye position dependence in monkeys. Two trained Macaca fascicularis performed reactive rightward saccades from five equally horizontally distributed starting positions. All saccades were made to targets with the same retinotopic motor vector. In each session, the saccades that started at one particular initial eye position, the adaptation position, were adapted to shorter amplitude, and the adaptation of the saccades starting at the other four positions was measured. The results show that saccades that started at the other positions were less adapted than saccades that started at the adaptation position. With increasing distance between the starting position of the test saccade and the adaptation position, the amplitude change of the test saccades decreased with a Gaussian profile. We conclude that gain-decreasing saccadic adaptation in macaques is specific to the initial eye position at which the adaptation has been induced. PMID:22933719

Wulff, Svenja; Bosco, Annalisa; Havermann, Katharina; Placenti, Giacomo; Fattori, Patrizia; Lappe, Markus

2012-11-01

447

Ocular iontophoresis of EGP-437 (dexamethasone phosphate in dry eye patients: results of a randomized clinical trial  

Directory of Open Access Journals (Sweden)

Full Text Available Michael A Patane¹, Amy Cohen¹, Stephen From¹, Gail Torkildsen², Donna Welch³, George W Ousler III³¹Eyegate Pharmaceuticals, Inc, Waltham, MA, USA; ²Andover Eye Associates, Andover, MA, USA; ³Ora, Inc, Andover, MA, USAPurpose: To assess safety and efficacy of EGP-437 (dexamethasone phosphate 40 mg/mL [DP] in dry eye patients.Methods: The study employed a prospective, single-center, double-masked design utilizing a Controlled Adverse Environment (CAE. Patients (n = 103 with confirmed signs and symptoms of dry eye syndrome were randomized into 1 of 3 iontophoresis treatment groups: 7.5 mA-min at 2.5 mA (DP 7.5, n = 41; 10.5 mA-min at 3.5 mA (DP 10.5, n = 37; or 10.5 mA-min at 3.5 mA (placebo, n = 25. Three CAE visits and 4 follow-up visits occurred over 3 weeks. Patients meeting enrollment criteria received iontophoresis in both eyes after the second CAE exposure (visit 3 and before the third CAE exposure (visit 5. Primary efficacy endpoints were corneal staining and ocular discomfort. Secondary endpoints included tear film break-up time, ocular protection index (OPI, and symptomatology.Results: The DP 7.5 and DP 10.5 treatment groups showed statistically significant improvements in signs and symptoms of dry eye at various time points; however, the primary endpoints were not achieved. The DP 7.5 treatment group exhibited statistically significant improvements in corneal staining (when comparing the differences between study entry and exit, 3 weeks, P = 0.039, OPI (immediately following the second treatment, P = 0.048 and ocular discomfort at follow-up visits (a week after the first treatment, P = 0.032; 24 hours after the second treatment, P = 0.0032. Treatment-emergent adverse events (AEs were experienced by 87% of patients and were consistent across all treatment groups. Most AEs were mild and no severe AEs were observed.Conclusion: Ocular iontophoresis of EGP-437 demonstrated statistically and clinically significant improvements in signs and symptoms of dry eye syndrome within a CAE model.Keywords: iontophoresis, dry eye, Controlled Adverse Environment (CAE, ocular protection index (OPI

Patane MA

2011-05-01

448

Circuital model for the Maxwell Fish Eye perfect drain  

CERN Document Server

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...

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

2012-01-01

449

Are 3-D Movies Bad for Your Eyes?  

Medline Plus

Full Text Available ... 3-D Movies Bad for Your Eyes? Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During ... and Eye Protection Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Opening Champagne Bottles ...

450

Eyes in the Sky  

Science.gov (United States)

This resource is part of the Science Education Gateway (SEGway) project, funded by NASA, which is a national consortium of scientists, museums, and educators working together to bring the latest science to students, teachers, and the general public. In this unit, students use technology to learn about orbiting spacecraft designed to study astronomical objects. Tools include a satellite dish, VCR, and computers. There is information for teachers about preparation, references, and lesson plan details.

Yager, Bryan

451

Virtual pharmacokinetic model of human eye.  

Science.gov (United States)

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

Kotha, Sreevani; Murtomäki, Lasse

2014-07-01

452

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

Science.gov (United States)

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.…

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

2011-01-01

453

Collie eye anomaly in Switzerland  

OpenAIRE

In this retrospective study, the results of 3’527 eye examinations in 6 different breeds affected with Collie Eye Anomaly (CEA) over a period of 8 years (1999 - 2007) are described. CEA was divided into three main ophthalmoscopic features, a) choroidal hypoplasia (CRH), b) CRH and coloboma and c) coloboma alone. Of the 101 Smooth Collies 8.9 % showed signs of CRH, whereas 36.9 % of Rough Collies were affected with CRH, 2.8 % with CRH and coloboma and 0.38 % with coloboma alone. Choroidal hy...

Walser-reinhardt, L.; Ha?ssig, M.; Spiess, B. M.

2009-01-01

454

A two-step experimental design for a sediment bioassay using growth of the amphipod Hyalella azteca for the test end point  

Energy Technology Data Exchange (ETDEWEB)

The authors designed a sediment bioassay using 25% growth inhibition of Hyalella azteca as the end point. Hyalella azteca exhibits size-specific fecundity, so growth is a surrogate of reproductive production. They investigated density effects on growth to address whether crowding could affect test interpretation; amphipods in 14,000/m{sup 2} exposures were 16 to 20% smaller than those at 7,000/m{sup 2}. Using power analysis, the authors found that 20 to 25 samples are required to determine significance when {alpha} = 0.10 and 1 {minus} {beta} = 0.90. To minimize the need for laboratory resources, they designed a two-step bioassay, which they tested with field-collected sediments. The screening bioassay compared 11 sediments to a reference. Three sediments were toxic, five sediments were nontoxic, and three sediments were possibly toxic. In the confirmatory bioassay, three possibly toxic and two nontoxic samples were reevaluated. Two were toxic, and the remaining four samples were nontoxic. In summary, five sediments were toxic and six sediments were nontoxic. The two-step analysis used minimal laboratory resources but maximized statistical power, where needed, to discriminate growth effects.

Kubitz, J.A.; Giesy, J.P. [Michigan State Univ., East Lansing, MI (United States); Besser, J.M. [Michigan State Univ., East Lansing, MI (United States)]|[National Biological Service, Columbia, MO (United States). Midwest Science Center

1996-10-01

455

THE SAMPLING ERROR OF ROTATOR ESTIMATES OF EYE VOLUME  

Directory of Open Access Journals (Sweden)

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.

Matthew G Reed

2011-05-01

456

Multimodal 'eyes-free' interaction techniques for wearable devices  

OpenAIRE

Mobile and wearable computers present input/output prob-lems due to limited screen space and interaction techniques. When mobile, users typically focus their visual attention on navigating their environment - making visually demanding interface designs hard to operate. This paper presents two multimodal interaction techniques designed to overcome these problems and allow truly mobile, 'eyes-free' device use. The first is a 3D audio radial pie menu that uses head gestures for selecting items. ...

Brewster, S. A.; Lumsden, J.; Bell, M.; Hall, M.; Tasker, S.

2003-01-01

457

Tipping Point  

Science.gov (United States)

... 2009 (2) « Hello and Welcome! Home The Tipping Point By CPSC Blogger on September 22, 2009 Watch ... www.cpsc.gov/onsafety/2009/09/the-tipping-point/ Product Safety Recall Info CPSC Links ATVSafety.gov ...

458

Frog eye, ear, and nostril  

Science.gov (United States)

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.

Ren West (None;)

2006-08-07

459

Radiation effects on eye components  

International Nuclear Information System (INIS)

The radiation damage (X-ray, UV light) of the most important components of the vertebrate eye (crystallins and other proteins, hyaluronic acid, vitreous, aqueous humour, ascorbic acid) has been investigated by various methods of physical chemistry. UV absorption and fluorescence spectroscopy as well as circular dichroism unveiled changes of the chromophores/fluorophores of the constituent biopolymers and low-molecular components, together with alterations of helix content and the occurrence of aggregation. Size-exclusion chromatography, analytical ultracentrifugation, densimetry, viscometry and light scattering experiments monitored changes of the global structure of proteins and polysaccharides involved. Electrophoreses allowed conclusions on fragmentation, unfolding and crosslinking. Analytical methods provided information regarding the integrity of groups of special concern (SH, SS) and revealed the existence of stable noxious species (H2O2). By means of various measures and additives, manifold modifications of the impact of both ionizing and nonionizing radiation may be achieved. Caused by differences in the primary reactions, eye polymers are protected efficaciously by typical OH radical scavengers against X-irradiation, whereas compounds which exhibit absorption behavior in the UV range turn out to act as potent protectives ('chemical filters') against UV light. A few substances, such as ascorbate, are able to provide protection against both sorts of radiation and are even able to exhibit a slight chemical repair of already damaged particles. The results obtained are of importance for understanding pathological alterations of the eye (loss of transparency, cataractogenesis) and for developing new strategies for protection and repair of eye components. (author)

460

Bologna with Student Eyes, 2007  

Science.gov (United States)

"Bologna with Student Eyes" is a survey published by the National Unions of Students in Europe, based on questionnaires sent to national unions across the continent. The survey gives a broad overview of student union perspectives as to national implementations of Bologna Process Action Lines in the period 2005-2007. It addresses the topics of:…

Mikkola, Anne, Ed.; Carapinha, Bruno, Ed.; Tuck, Colin, Ed.; MacSithigh, Daithi, Ed.; Aberg, Nina Gustaffson, Ed.; Brus, Sanja, Ed.

2007-01-01

461

Deformable Models for Eye Tracking  

DEFF Research Database (Denmark)

A deformable template method for eye tracking on full face images is presented. The strengths of the method are that it is fast and retains accuracy independently of the resolution. We compare the me\\$\\backslash\\$-thod with a state of the art active contour approach, showing that the heuristic method is more accurate.

Vester-Christensen, Martin; Leimberg, Denis

2005-01-01

462

Soccer-Related Eye Injuries.  

Science.gov (United States)

A review of medical charts of 13 youths (age 8-15) with soccer-related eye injuries identified as causes: a head butt, kicks, the ball. Risks can be lessened by use of polycarbonate eyeguards, properly inflated balls, adequate conditioning and practice before scrimmages, a moderate and balanced practice/playing schedule and good sportsmanship.…

Orlando, Richard G.

1988-01-01

463

If I Had - Dry Eyes  

Medline Plus

Full Text Available ... New York (July 10, 2009 - Insidermedicine) In this video, Dr. Penny Asbell, MD, FACS, MBA, discusses what she ... syndrome. It’s really a common problem that can present in many different ways. How is dry eye treated? Dr. Asbell: Just recently there was actually a group ...

464

If I Had - Dry Eyes  

Medline Plus

Full Text Available ... the ones that is popular is in this area is cyclosporine which is available as an eye drop. So there are a bunch of things that you can try. And that’s one of the things to know. Not all artificial tears are the same. You need to ... | Sitemap | Privacy | Request A Custom Feed © ...

465

Nutrients for the aging eye.  

Science.gov (United States)

The incidence of age-related eye diseases is expected to rise with the aging of the population. Oxidation and inflammation are implicated in the etiology of these diseases. There is evidence that dietary antioxidants and anti-inflammatories may provide benefit in decreasing the risk of age-related eye disease. Nutrients of interest are vitamins C and E, ?-carotene, zinc, lutein, zeaxanthin, and the omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid. While a recent survey finds that among the baby boomers (45-65 years old), vision is the most important of the five senses, well over half of those surveyed were not aware of the important nutrients that play a key role in eye health. This is evident from a national survey that finds that intake of these key nutrients from dietary sources is below the recommendations or guidelines. Therefore, it is important to educate this population and to create an awareness of the nutrients and foods of particular interest in the prevention of age-related eye disease. PMID:23818772

Rasmussen, Helen M; Johnson, Elizabeth J

2013-01-01

466

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 ...

467

Flood-Related Eye Care Precautions  

Science.gov (United States)

... Z Listing Good Vision For Life Infants Children Adults Seniors Caring for Your Vision Eye & Vision Exams Contact Lenses Diet and Nutrition UV Protection Resources for Teachers 3D Vision & Eye Health Classroom Exercises ...

468

Antioxidants and Age-Related Eye Disease  

Science.gov (United States)

... Z Listing Good Vision For Life Infants Children Adults Seniors Caring for Your Vision Eye & Vision Exams Contact Lenses Diet and Nutrition UV Protection Resources for Teachers 3D Vision & Eye Health Classroom Exercises ...

469

Prevent Diabetes Problems: Keep Your Eyes Healthy  

Science.gov (United States)

... Info Statistics Research Resources About Us Español National Diabetes Information Clearinghouse Publications Tools and Resources E-News ... Prevent diabetes problems: Keep your eyes healthy Prevent diabetes problems: Keep your eyes healthy On this page: ...

470

A history of eye gaze tracking  

OpenAIRE

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.

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

2007-01-01

471

30 CFR 56.15004 - Eye protection.  

Science.gov (United States)

...2010-07-01 false Eye protection. 56.15004...Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT...NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL...Protection § 56.15004 Eye protection....

2010-07-01

472

30 CFR 57.15004 - Eye protection.  

Science.gov (United States)

...2010-07-01 false Eye protection. 57.15004...Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT...NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND...Underground § 57.15004 Eye protection....

2010-07-01

473

Prescriptions for Eye Glasses and Contact Lenses  

Science.gov (United States)

... for Erectile Dysfunction Prescriptions for Eye Glasses and Contact Lenses Remedies for the Common Cold The Basics of LASIK Eye Surgery Weight Loss & Fitness Jobs & Making Money Privacy & Identity Blog Video & Media Scam Alerts ...

474

Localized whole eye radiotherapy for retinoblastoma using a 125I applicator, 'claws'  

International Nuclear Information System (INIS)

Purpose: To treat children with retinoblastoma, who require whole eye radiotherapy, with a specially designed 125I applicator that irradiates the eye while sparing the surrounding tissues. Methods and Materials: Under general anesthesia, a pericorneal ring is attached to the 4 extraocular muscles, and 4 appendages, each loaded with 125I seeds, are inserted beneath the conjunctiva in-between each pair of muscles and attached anteriorly to the ring. Twenty-nine eyes were treated. Eighteen received a median dose of 28 Gy during 91 hours and 11 received 40 Gy during 122 hours, when the relative biologic effectiveness was taken as 1 instead of 1.5. Six had received prior chemotherapy. Results: Twenty-four eyes were followed up for 2-157 months (median 29). Although 22 eyes responded, local control was achieved in 13 patients, 3 of whom required additional treatment for new tumors; a further 3 required additional treatment for tumor recurrence as well as new tumors. One of these eyes was enucleated for neovascular glaucoma. All 6 Group I-III eyes and 6 of 18 Group V eyes were retained for 2-157 months (median 39), with good vision in 10 eyes. Three developed cataracts 7, 8, and 12 years later, 1 of which has been removed. Conclusions: This is a new way of irradiating the whole eye with a minimal dose to the surrounding tissues. The treatment time is only 5 days. It is effective in Groups I-III, but only 33% of Group V eyes retained vision. No late cosmGroup V eyes retained vision. No late cosmetic defects occurred

475

Cystatin C and lactoferrin concentrations in biological fluids as possible prognostic factors in eye tumor development  

Directory of Open Access Journals (Sweden)

Full Text Available Objectives. To investigate the possible role of cystatin C in eye biological fluids locally and in serum and lactoferrin revealing anti-tumor activity in eye tumor development. Background. The increased number of eye tumors was registered recently not only in the countries with high insolation, but also in the northern countries including Russia (11 cases per million of population. Search for new biological markers is important for diagnosis and prognosis in eye tumors. Cystatin C, an endogenous inhibitor of cysteine proteases, plays an important protective role in several tumors. Lactoferrin was shown to express anti-tumor and antiviral activities. It was hypothesized that cystatin C and lactoferrin could serve as possible biomarkers in the diagnosis of malignant and benign eye tumors. Study design. A total of 54 patients with choroidal melanoma and benign eye tumors were examined (part of them undergoing surgical treatment. Serum, tear fluid and intraocular fluid samples obtained from the anterior chamber of eyes in patients with choroidal melanoma were studied. Methods. Cystatin C concentration in serum and eye biological fluids was measured by commercial ELISA kits for human (BioVendor, Czechia; lactoferrin concentration – by Lactoferrin-strip D 4106 ELISA test systems (Vector-BEST, Novosibirsk Region, Russia. Results. Cystatin C concentration in serum of healthy persons was significantly higher as compared to tear and intraocular fluids. In patients with choroidal melanoma, increased cystatin C concentration was similar in tear fluid of both the eyes. Lactoferrin level in tear fluid of healthy persons was significantly higher than its serum level. Significantly increased lactoferrin concentration in tear fluid was noted in patients with benign and malignant eye tumors. Conclusion. Increased level of cystatin C in tear fluid seems to be a possible diagnostic factor in the eye tumors studied. However, it does not allow us to differentiate between malignant and benign eye tumors. Similar changes were noted for lactoferrin in tear fluid.

Mariya A. Dikovskaya

2013-08-01

476

Four Eyes Are Better  

Science.gov (United States)

VLT Interferometer Passes Another Technical Hurdle Summary During the nights of September 15/16 and 16/17, 2002, preliminary tests were successfully carried out during which the light beams from all four VLT 8.2-m Unit Telescopes (UTs) at the ESO Paranal Observatory were successively combined, two by two, to produce interferometric fringes . This marks a next important step towards the full implementation of the VLT Interferometer (VLTI) that will ultimately provide European astronomers with unequalled opportunities for exciting front-line research projects. It is no simple matter to ensure that the quartet of ANTU, KUEYEN, MELIPAL and YEPUN , each a massive giant with a suite of computer-controlled active mirrors, can work together by sending beams of light towards a common focal point via a complex system of compensating optics. Yet, in the span of only two nights, the four VLT telescopes were successfully "paired" to do exactly this, yielding a first tantalizing glimpse of the future possibilities with this new science machine. While there is still a long way ahead to the routine production of extremely sharp, interferometric images, the present test observations have allowed to demonstrate directly the 2D-resolution capacity of the VLTI by means of multiple measurements of a distant star. Much valuable experience was gained during those two nights and the ESO engineers and scientists are optimistic that the extensive test observations with the numerous components of the VLTI will continue to progress rapidly. Five intense, technical test periods are scheduled during the next six months; some of these with the Mid-Infrared interferometric instrument for the VLTI (MIDI) which will soon be installed at Paranal. Later in 2003, the first of the four moveable VLTI 1.8-m Auxiliary Telescopes (ATs) will be put in place on the top of the mountain; together they will permit regular interferometric observations, also without having to use the large UTs. PR Photo 22a/02 : Delay Lines in the Interferometric Tunnel. PR Photo 22b/02 : Baselines and "Interferometric PSF" from observations of the star Achernar . Combining the VLT telescopes ESO PR Photo 22a/02 ESO PR Photo 22a/02 [Preview - JPEG: 503 x 400 pix - 81k] [Normal - JPEG: 1005 x 800 pix - 488k] [Hi-Res - JPEG: 3000 x 2389 pix - 2.8M] Caption : PR Photo 22a/02 : VLT Delay Lines in the Interferometric Tunnel. Less than one year after the first combination of two 8.2-m VLT telescopes - described in detail in ESO Press Release 23/01 - successful tests have now been carried out, during which all of the four telescopes were combined pairwise in rapid succession . Of the six combinations possible (ANTU-KUEYEN, ANTU-MELIPAL, ANTU-YEPUN, KUEYEN-MELIPAL, KUEYEN-YEPUN and MELIPAL-YEPUN), only the last one could not be used, because of the current geometrical configuration of the three delay lines installed so far. The combination of the light beams from two (or more) VLT Unit Telescopes is a daunting task. It involves pointing them simultaneously towards the same celestial object, ensuring optimal optical adjustment of the computer-controlled telescope mirrors (including the shape of the 8.2-m primary mirror by "active optics"), performing extremely smooth and stable tracking of the object as the Earth turns, guiding the light beams via additional ("coudé") mirrors into the "delay lines" installed in the Interferometric Tunnel below the telescope platform, keeping the total path lengths equal to within a fraction of a micron during hours at a time and finally, to register the interferometric fringes at the focal point of the VINCI instrument [1], where the light beams encounter each other. Next year, the first adaptive optics systems for the VLTI will be inserted below the telescopes. By drastically reducing the smearing effects of the turbulent atmosphere through which the light has to pass before it enters the telescopes, this will further "stabilize" the imaging and increase the sensitivity of the VLTI by a factor of alm

2002-09-01

477

Ophthalmic Diagnostics Using Eye Tracking Technology  

OpenAIRE

Human eyes directly reflect brain activity and cognition. The study of eye movements and gaze patterns can therefore say a lot about the human brain and human behavior. Today eye tracking technology is being used to measure acuity of toddlers, to rehabilitate patients in intensive care, to detect if a person is lying or not, and to understand the cognitive level of a non-verbal person. Current vision testing is mostly based on manual observation and subjective methods. With eye tracking techn...

Aldana Pulido, Rafael

2012-01-01

478

An improved likelihood model for eye tracking  

DEFF Research Database (Denmark)

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.

Hansen, Dan Witzner; Hammoud, Riad I.

2007-01-01

479

Pax6 and eye development in Arthropoda.  

OpenAIRE

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...

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

2006-01-01

480

Eyeing the Sky's Water Vapor  

Science.gov (United States)

This image, and many like it, are one way NASA's Phoenix Mars Lander is measuring trace amounts of water vapor in the atmosphere over far-northern Mars. Phoenix's Surface Stereo Imager (SSI) uses solar filters, or filters designed to image the sun, to make these images. The camera is aimed at the sky for long exposures. SSI took this image as a test on June 9, 2008, which was the Phoenix mission's 15th Martian day, or sol, since landing, at 5:20 p.m. local solar time. The camera was pointed about 38 degrees above the horizon. The white dots in the sky are detector dark current that will be removed during image processing and analysis. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space

2008-01-01