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Sample records for design eye point

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

    Science.gov (United States)

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

    2012-06-01

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

  2. Eye tracking in user experience design

    CERN Document Server

    Romano Bergstorm, Jennifer

    2014-01-01

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

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

    DEFF Research Database (Denmark)

    Jalaliniya, Shahram; Mardanbeigi, Diako

    2014-01-01

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

  4. Measurement of the photoreceptor pointing in the living chick eye.

    Science.gov (United States)

    Walker, Maria K; Blanco, Leonardo; Kivlin, Rebecca; Choi, Stacey S; Doble, Nathan

    2015-04-01

    The chick eye is used in the study of ocular growth and emmetropization; however optical aberrations in the lens and cornea limit the ability to visualize fine retinal structure in living eyes. These aberrations can be corrected using adaptive optics (AO) allowing for cellular level imaging in vivo. Here, this capability is extended to measure the angular tuning properties of individual photoreceptors. The left eyes from two White Leghorn chicks (Gallus gallus domesticus) labeled chick A and chick B, were imaged using an AO flood illuminated fundus camera. By translating the entrance pupil position, the same retinal location was illuminated with light of varying angles allowing for the measurement of individual photoreceptor pointing. At 30° nasal from the pecten tip, the pointing direction for both chicks was towards the pupil center with a narrow distribution. These particular chicks were found to have a temporal (T) and inferior (I) bias in the alignment with peak positions of (0.81 T, 0.23 I) and (0.57 T, 0.18 I) mm from the pupil center for chicks A and B respectively. The rho, ?, values for the major, ?L, and minor, ?s, axes were 0.14 and 0.17mm(-2) for chick A and 0.09 and 0.20mm(-2) for chick B. The small disarray in the alignment of the chick photoreceptors implies that the photoreceptors are aligned to optimize the light entering the eye through the central portion of the pupil aperture. The ability to measure pointing properties of individual photoreceptors will have application in the study of eye growth and various retinal disorders. PMID:25722105

  5. Design of Eye Movement Interactive Interface and Example Development

    Directory of Open Access Journals (Sweden)

    Kong Xiang-Zong

    2013-01-01

    Full Text Available With the unceasing development of HCI (Human Computer Interaction technology, natural interactive products are valued by more and more people. The next generation of man-machine interface may use touch, hearing or vision, etc. Among them, the visual sense is the most important channel to get information, but researches are mostly focused on the measurement of eye movement or data processing. In the future, the interaction of eyes with machines will have a very wide prospect. After concluding the pluses and minuses of available eye control systems, we puts forth the design principle, system concept and the state transition model of eyes interaction from the consideration of user-centered design principle. The system simplifies the measurement process, focuses on the fast tracking, calibration and accurate eye movement identification. At the same time, we use context information to reduce interaction time and combines with keys to eliminate eye movements’ ambiguity. Based on the design scheme, we develop a system-EyeHUD(Eye Head Up Diaplay which can be applied in driving. It includes an eye preset interface, an eye control interface and a virtual vehicle scene. Before starting cars, a driver uses the eye tracker to track and calibrate eyes, then chooses an interactive function, like one blink zoom in or two blink chick. When the eye control interface is opened, the driver can use auto eye control to operate it, or choose eyes+keys way to simulate a click. The evaluation results shows: EyeHUD can successfully achieve all the default function and participants don’t need long time to understand the information provided by the interface. Compared with the eyes+keys way, the auto eye control has no obvious difference in recognition success rate.

  6. Optimization of Eye End Design of a Single Leaf Spring

    OpenAIRE

    Jayanaidu; M Hibbatullah; Baskar, P

    2014-01-01

    This paper is focused on determination of better eye end design and better material among Titanium and Steel for a single leaf spring. The procedure of this work is to carry out computer aided design and analysis of conventional single leaf spring with actual design considerations and loading conditions. This conventional 65Si7 spring steel leaf spring model and Titanium alloy (Ti 6Al 7Nb) with standard eye end, centred eye end and Inverted eye end are considered. The CAD model of the leaf sp...

  7. Two Eyes, 3D: Stereoscopic Design Principles

    Science.gov (United States)

    Price, Aaron; Subbarao, M.; Wyatt, R.

    2013-01-01

    Two Eyes, 3D is a NSF-funded research project about how people perceive highly spatial objects when shown with 2D or stereoscopic ("3D") representations. As part of the project, we produced a short film about SN 2011fe. The high definition film has been rendered in both 2D and stereoscopic formats. It was developed according to a set of stereoscopic design principles we derived from the literature and past experience producing and studying stereoscopic films. Study participants take a pre- and post-test that involves a spatial cognition assessment and scientific knowledge questions about Type-1a supernovae. For the evaluation, participants use iPads in order to record spatial manipulation of the device and look for elements of embodied cognition. We will present early results and also describe the stereoscopic design principles and the rationale behind them. All of our content and software is available under open source licenses. More information is at www.twoeyes3d.org.

  8. Optimization of Eye End Design of a Single Leaf Spring

    Directory of Open Access Journals (Sweden)

    Jayanaidu

    2014-05-01

    Full Text Available This paper is focused on determination of better eye end design and better material among Titanium and Steel for a single leaf spring. The procedure of this work is to carry out computer aided design and analysis of conventional single leaf spring with actual design considerations and loading conditions. This conventional 65Si7 spring steel leaf spring model and Titanium alloy (Ti 6Al 7Nb with standard eye end, centred eye end and Inverted eye end are considered. The CAD model of the leaf springs is prepared in PRO-E and analysed using ANSYS. Static testing and finite element analysis have been carried out to obtain the characteristics of the spring. The standard eye and centred eye leaf springs are subjected to similar loading conditions. The CAE analysis of the leaf spring is performed for various parameters like Total deflection, von-misses stress and normal stress. The main objective of this work is to determine the better eye end design and select the best material among Steel and Titanium alloy and to reduce the time and cost related to actual experimental testing by providing a CAE solution.

  9. The RapidEye mission design

    Science.gov (United States)

    Tyc, George; Tulip, John; Schulten, Daniel; Krischke, Manfred; Oxfort, Michael

    2005-01-01

    The RapidEye mission is a commercial remote sensing mission by the German Company RapidEye AG. The RapidEye mission will deliver information products for various customers in the agricultural insurance market, large producers, international institutions and cartography. The mission consists of a constellation of five identical small satellites and a sophisticated ground infrastructure based on proven systems. The five satellites will be placed in a single sun-synchronous orbit of approximately 620 km, with the satellites equally spaced over the orbit. The RapidEye system has the unique ability to image any area on earth once per day and can also provide large area coverage within 5 days. The satellites will each carry a 5 band multi-spectral optical imager with a ground sampling distance of 6.5 m at nadir and a swath width of 80 km. These capabilities along with the processing throughput of the ground segment allows the system to deliver the information products needed by the customers reliably and in a time frame that meets their specific needs.

  10. Point prevalence of pseudoexfoliation syndrome in patients scheduled for cataract surgery in eye camps in Yemen

    OpenAIRE

    Al-Shaer Mutahar; Bamashmus Mahfouth; Al-Barrag Abdulmoghni

    2010-01-01

    Purpose: To study the point prevalence of pseudoexfoliation syndrome (PXS) among Yemeni patients in different governorates with age-related cataract scheduled for surgery. Settings: Eye camps organized by the Nibras Health Society to perform cataract surgeries during the years 2002-2006. All patients aged 40 years and above were included in the study. Materials and Methods: A total of 2535 eyes of 2535 patients from 13 governorates, scheduled for cataract surgery in eye camps, were included. ...

  11. Turning points in reactor design

    Energy Technology Data Exchange (ETDEWEB)

    Beckjord, E.S.

    1995-09-01

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

  12. 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

  13. West Point Bridge Design Contest

    Science.gov (United States)

    The second annual West Point Bridge Design Contest concluded in May 2003. Although it is uncertain whether the contest will receive funding for future competitions, its Web site has a number of educational resources for middle and high school students. The main feature is the bridge design software, which allows the user to "model, test, and optimize a steel highway bridge, based on realistic specifications, constraints, and performance criteria." Completed designs can be submitted online for unofficial judging. The book, Designing and Building File-Folder Bridges, can also be freely downloaded. [CL

  14. Dynamical Systems in Circuit Designer's Eyes

    Energy Technology Data Exchange (ETDEWEB)

    Odyniec, M.

    2011-05-09

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

  15. Design and manufacturing of complex optics: the dragonfly eye optic.

    Energy Technology Data Exchange (ETDEWEB)

    Claudet, Andre A.; Sweatt, William C.; Hodges, V. Carter; Adams, David Price; Gill, David Dennis; Vasile, Michael J.

    2006-01-01

    The ''Design and Manufacturing of Complex Optics'' LDRD sought to develop new advanced methods for the design and manufacturing of very complex optical systems. The project team developed methods for including manufacturability into optical designs and also researched extensions of manufacturing techniques to meet the challenging needs of aspherical, 3D, multi-level lenslet arrays on non-planar surfaces. In order to confirm the applicability of the developed techniques, the team chose the Dragonfly Eye optic as a testbed. This optic has arrays of aspherical micro-lenslets on both the exterior and the interior of a 4mm diameter hemispherical shell. Manufacturing of the dragonfly eye required new methods of plunge milling aspherical optics and the development of a method to create the milling tools using focused ion beam milling. The team showed the ability to create aspherical concave milling tools which will have great significance to the optical industry. A prototype dragonfly eye exterior was created during the research, and the methods of including manufacturability in the optical design process were shown to be successful as well.

  16. Design and development of miniature parallel robot for eye surgery.

    Science.gov (United States)

    Sakai, Tomoya; Harada, Kanako; Tanaka, Shinichi; Ueta, Takashi; Noda, Yasuo; Sugita, Naohiko; Mitsuishi, Mamoru

    2014-01-01

    A five degree-of-freedom (DOF) miniature parallel robot has been developed to precisely and safely remove the thin internal limiting membrane in the eye ground during vitreoretinal surgery. A simulator has been developed to determine the design parameters of this robot. The developed robot's size is 85 mm × 100 mm × 240 mm, and its weight is 770 g. This robot incorporates an emergency instrument retraction function to quickly remove the instrument from the eye in case of sudden intraoperative complications such as bleeding. Experiments were conducted to evaluate the robot's performance in the master-slave configuration, and the results demonstrated that it had a tracing accuracy of 40.0 ?m. PMID:25569974

  17. Design of a new two element OSLD Badge for eye lens monitoring

    International Nuclear Information System (INIS)

    Normally the dose to the vicinity of the eye is received by the occupational radiation workers who handle radioisotopes or doctors who perform interventional radiographic procedures. The Eye dosimeters provide an estimate of the radiation dose to the lens of the eye. In the recent ICRP-2011 recommendations, the equivalent dose limit for the lens of the eye has been reduced from 150 mSv in a year to 20 mSv in a year for all the occupational workers. To ensure that the dose limit for the eye lens does not exceed the prescribed dose limits, various eye lens dosimeters have been designed and are being used internationally. All these eye dosimeters consist of one natural LiF based thermoluminescence dosimeter (TLD) element sealed in a plastic holder. The design of the eye dosimeter and place of wear (near the eye) plays an important role in correct estimation of the dose to the lens of the eye. It is generally seen that the eye dosimeter when worn with the head strap on the forehead near the eye, the dose the element receives can be easily correlated to the eye dose. This paper presents the design of a new Eye lens dosimeter based on optically stimulated luminescence (OSL) detectors for its possible use by the occupational workers covering the medical, industrial and nuclear facilities for assessing the Hp(3)

  18. Point prevalence of pseudoexfoliation syndrome in patients scheduled for cataract surgery in eye camps in Yemen

    Directory of Open Access Journals (Sweden)

    Al-Shaer Mutahar

    2010-01-01

    Full Text Available Purpose: To study the point prevalence of pseudoexfoliation syndrome (PXS among Yemeni patients in different governorates with age-related cataract scheduled for surgery. Settings: Eye camps organized by the Nibras Health Society to perform cataract surgeries during the years 2002-2006. All patients aged 40 years and above were included in the study. Materials and Methods: A total of 2535 eyes of 2535 patients from 13 governorates, scheduled for cataract surgery in eye camps, were included. All eyes underwent complete eye examination before the surgery and were evaluated for the signs of pseudoexfoliation material in the pupil, iris and lens capsule on dilated slit lamp examination. Results: The study found 495 of the 2535 eyes (19.53% with PXS with males more commonly affected than females (55.2 and 44.8%, respectively. The mean age of patients with PXS was 66.2 years while it was 64.6 years in non-PXS patients. The prevalence of pseudoexfoliation syndrome increased with age (10.1% in the age group of 41-50 years that increased to 28.8% in the age group of more than 81 years old. The rate of PXS detection in camps in 13 governorates ranged from 13.33 to 24.22% with an overall rate of 19.53%. The lowest rate was noticed in Sana?a and the highest in Al-Dhale governorate. Conclusion: This pilot study confirms that PXS was common in patients undergoing cataract surgery in Yemen with an increased detection rate with age. This study also highlights the prevalence of an ocular disease that is associated with systemic and ocular complications; however, further studies based on population studies are needed.

  19. Retrieval of wave aberration of human eyes from actual point-spread-function data.

    OpenAIRE

    Artal, Pablo; Santamari?a, J.; Besco?s, J.

    1988-01-01

    The wave aberration of human eyes is retrieved from actual point-spread-function (PSF) data and the modulus of the pupil function. The PSF had been obtained previously by application of a hybrid optical-digital method developed recently. The retrieval is done by using a bidimensional Gerchberg-Saxton phase-retrieval algorithm joined to an iterative phase-unwrapping algorithm. To obtain an adequate convergence, the initial wave aberration for starting the retrieval-unwrapping algorithm is esti...

  20. Design of Customizable Automated Low Cost Eye Testing System

    OpenAIRE

    K, Ganesan; D, Shalini

    2014-01-01

    Background and Objectives: In many underdeveloped and third world countries, eye care is often neglected due to illiteracy. Particularly people in rural areas suffer with eye problems due to mal nutrition. The government is spending lot of money and efforts in screening the people at periodic intervals. One of the challenges faced by the doctors is screening the school children.

  1. Design of Eye Movement Interactive Interface and Example Development

    OpenAIRE

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

    2013-01-01

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

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

    Science.gov (United States)

    Polulyakh, Valeriy; Poutivski, Iouri

    2014-05-01

    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.

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Polulyakh, Valeriy [Advanced Data Security, 1933 O' Toole Way, San Jose, CA 95131 (United States); Poutivski, Iouri [Terimber Corporation, 2456 Homewood Drive, San Jose, CA 95128, USA and Facebook Inc, 1601 Willow Road, Menlo Park, CA 94025 (United States)

    2014-05-27

    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.

  5. Design and evaluation of a public installation of an eye-gaze system.

    Science.gov (United States)

    Lin, Chern-Sheng; Yang, Hui-Jen; Lay, Yun-Long; Yang, Shih-Wei

    2011-01-01

    This article evaluates an eye-tracking device ("I Can Speak With My Eyes") designed for a museum exhibition. An eye-tracking system is designed not only for able individuals, but also for bedridden patients or physically handicapped people who intend to use computers. With one video CCD camera and frame grabber analyzing a series of images taken of the human pupil gazing at a screen, an auto-range-finding algorithm can be used to obtain the location of the pupil in real time. The computers will produce speech according to the location of where the eyes are gazing. In essence, the participants can speak with their eyes to achieve the advantages of learning and communicating. After the system was implemented, an experimental evaluation with innovation diffusion theory was conducted to survey users' feelings regarding the system. The implications of the evaluation findings are discussed to aid further research and education. PMID:22256667

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

    OpenAIRE

    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

    2014-01-01

    In this paper we briefly summarize the design concepts of the Fly's Eye Camera System, a proposed high resolution all-sky monitoring device which intends to perform high cadence time domain astronomy in multiple optical passbands while still accomplish a high \\'etendue. Fundings have already been accepted by the Hungarian Academy of Sciences in order to design and build a Fly's Eye device unit. Beyond the technical details and the actual scientific goals, this paper also dis...

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

    Science.gov (United States)

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

    2009-08-01

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

  8. Design of an IRFPA point-by-point bias calibration

    Science.gov (United States)

    He, Wei; Lv, Jian; Zhou, Yun; Du, Yiying; Yu, Caideng; Xie, Guangzhong; Yuan, Kai

    2012-10-01

    Infrared focal plane array (IRFPA) is a key component in infrared system and thermal imaging devices, widely applied in military and civilian fields, with a huge market potential and prospects. IRFPA readout circuit technology and test technology in its research occupies an important position, related to the ability to accurately and efficiently obtain the IRFPA signal and the ability of IRFPA devices for accurate performance evaluation. This paper uses an IRFPA point-by-point bias calibration, through a series of accurate timing control signals to read and save the calibration data and external input, effectively increases the point-by-point bias control accuracy, and finally improves the quality of the output image.

  9. 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

  10. Visual Eye Tracking Data as Medium in User Dialogue - Service Design’s Perspective

    OpenAIRE

    Hyo?kki, Satu

    2011-01-01

    Eye tracking allows us to observe the eye movements of the users, simplified, a scan path of the user reveals us what ?is drawing the attention or inattention of the user. Eye tracking can bring added value to user research by providing ?insights that would not be available with more conventional research methods, such as things that user is no longer ?recalling, or not realising they even took place. ? The objective of this thesis was to find out how visual eye tracking data coul...

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

    DEFF Research Database (Denmark)

    Bertelsen, Geir; Erke, Maja G

    2013-01-01

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

  12. The optic chiasm: a turning point in the evolution of eye/hand coordination

    OpenAIRE

    Larsson, Matz

    2013-01-01

    The primate visual system has a uniquely high proportion of ipsilateral retinal projections, retinal ganglial cells that do not cross the midline in the optic chiasm. The general assumption is that this developed due to the selective advantage of accurate depth perception through stereopsis. Here, the hypothesis that the need for accurate eye-forelimb coordination substantially influenced the evolution of the primate visual system is presented. Evolutionary processes may change the direction ...

  13. The Fly's Eye Camera System: An Instrument Design for Large Étendue Time Domain Surveys

    Science.gov (United States)

    Csépány, G.; Pál, A.; Vida, K.; Regály, Z.; Mészáros, L.; Oláh, K.; Kiss, C.; Döbrentei, L.; Jaskó, A.; Mezõ, G.; Farkas, E.

    2013-10-01

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

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

    CERN Document Server

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

    2014-01-01

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

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

    CERN Document Server

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

    2013-01-01

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

  16. The Fly's Eye Camera System: An instrument design for large étendue time-domain survey

    Science.gov (United States)

    Pál, A.; Mészáros, L.; Csépány, G.; Jaskó, A.; Schlaffer, F.; Vida, K.; Mez?, Gy.; Döbrentei, L.; Farkas, E.; Kiss, Cs.; Oláh, K.; Regály, Zs.

    2013-11-01

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

  17. Program computes single-point failures in critical system designs

    Science.gov (United States)

    Brown, W. R.

    1967-01-01

    Computer program analyzes the designs of critical systems that will either prove the design is free of single-point failures or detect each member of the population of single-point failures inherent in a system design. This program should find application in the checkout of redundant circuits and digital systems.

  18. Dynamics and mission design near libration points

    CERN Document Server

    Gómez, G; Jorba, A; Masdemont, J

    2001-01-01

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

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

    Directory of Open Access Journals (Sweden)

    G.V. Sorokoletov

    2013-02-01

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

  20. EyeRing

    OpenAIRE

    Nanayakkara, Suranga; Shilkrot, Roy; Yeo, Kian Peen; Maes, Patricia

    2013-01-01

    Finger-worn interfaces remain a vastly unexplored space for user interfaces, despite the fact that our fingers and hands are naturally used for referencing and interacting with the environment. In this paper we present design guidelines and implementation of a finger-worn I/O device, the EyeRing, which leverages the universal and natural gesture of pointing. We present use cases of EyeRing for both visually impaired and sighted people. We discuss initial reactions from visually impaired users...

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

    Science.gov (United States)

    Taherkhani, Reza; Kia, Mohammad

    2012-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Dandona Rakhi

    1997-01-01

    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.

  3. 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)

  4. Eye movement

    International Nuclear Information System (INIS)

    This is a special lecture at the 96th Annual Congress of the Japanese Ophthalmological Society in 1992, presenting studies on eye movement using magnetic resonance imaging (MRI). Using cine mode MRI technology, two methods for producing a series of photographs have been invented: (1) the moving eye method or dynamic method in which the subjects were asked to perform 256 or 512 vertical and horizontal eye movements in synchronization with a sound trigger; and (2) the fixed eye method or static method in which the subjects were asked to gaze at individual points in a 5 to 7 point sequence as indicated by the investigator. MRI data was generated and the resulting series of photographs were observed in cine mode on a televisin monitor. Displaying the MRI-generated photographs in cine mode enables direct observation of eye movement, optic nerve and extraocular muscles within the orbit. Although the moving eye method is more accurate in its portrayal of the actual eye movement, at least 256 eye movements are required for about 5 minutes, causing physical and mental load for the subjects. The fixed eye method was thus used to examine ophthalmoplegia, including abducens palsy, oculomotor palsy, fracture of the orbital wall, foreign bodies in the orbit, Duane's syndrome, endocrine myopathy, esotropia and exotropia. This allowed the investigation of anatomical changes, such as atrophy or hypertrophy, and the functional state caused by contraction and relaxation of the extraoculontraction and relaxation of the extraocular muscles. Transposition of the extraocular muscles for paralytic squint was reexamined and a new surgical procedure was developed for abducens palsy. The measurement of the length, thickness and weight of the extraocular muscles from the MRI-generated photographs allowed more accurate analysis. Three dimensional reconstructive method of MRI provided a valuable tool for evaluating the orbit. (N.K.) 67 refs

  5. Revised Point of Departure Design Options for Nuclear Thermal Propulsion

    Science.gov (United States)

    Fittje, James E.; Schnitzler, Bruce G.; Borowoski, Stanley

    2015-01-01

    Four Revised Point of Departure NTR Engines were Designed and Analyzed using MCNP and NESS. All Four Engines Have Thermodynamically Closed Cycles at Nominal Chamber Pressures. 111 kilonewton (25 kip-force) Cermet Design Required Dedicated Heater Elements to Close the Cycle. Cermet Based Designs had Slightly Higher TW Ratios, but Required Substantially More U-235. NERVA Derived Criticality Limited Engine Could Operate at Lower Power and Thrust Levels Compared to the Criticality Limited Cermet Design.

  6. Design of a reversible single precision floating point subtractor

    OpenAIRE

    Anantha Lakshmi, Av; Sudha, Gf

    2014-01-01

    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 ...

  7. Oogknipbeheerde rekenaarmuis: ontwerp en evaluering Eye-blink controlled computer mouse: design and evaluation

    Directory of Open Access Journals (Sweden)

    S. Viljoen

    2004-09-01

    Full Text Available Motories gestremde persone vind dit moeilik om ’n rekenaar te gebruik vanweë die feit dat hulle nie ’n muis kan beheer nie. In hierdie artikel word die ontwerp, implementering en evaluering van ’n oogknipbeheerde rekenaarmuis vir gebruik deur gestremde persone beskryf. Die deteksie van willekeurige oogknippe word deur middel van die weerkaatsing van infrarooi- (IR- lig vanaf die vel langs die oog bewerkstellig, terwyl onwillekeurige knippe verwerp word. Dit stel motories gestremde persone, wat nie meer die gebruik van hul arms het nie, in staat om ’n rekenaar te bedryf. Al die funksies van ’n PS2-muis word geëmuleer.Physically disabled people who do not have the use of their limbs have difficulty operating a computer, since they cannot use a mouse. In this article the design, implementation and evaluation of an eye-blink controlled computer mouse to be used by handicapped people are described. Detection of voluntary blinks is established by the reflection of infrared light from the skin on the side of the eye, while involuntary blinks are ignored. This enables people who do not have the use of their limbs to operate a computer. All the functions of a PS2 mouse are emulated.

  8. Microsoft Office SharePoint Designer 2007 Step by Step

    CERN Document Server

    Coventry, Penelope

    2008-01-01

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

  9. An Eye Tracking Comparison of External Pointing Cues and Internal Continuous Cues in Learning with Complex Animations

    Science.gov (United States)

    Boucheix, Jean-Michel; Lowe, Richard K.

    2010-01-01

    Two experiments used eye tracking to investigate a novel cueing approach for directing learner attention to low salience, high relevance aspects of a complex animation. In the first experiment, comprehension of a piano mechanism animation containing spreading-colour cues was compared with comprehension obtained with arrow cues or no cues. Eye

  10. Design of a reversible single precision floating point subtractor.

    Science.gov (United States)

    Anantha Lakshmi, Av; Sudha, Gf

    2014-01-01

    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

  11. Change-point in stochastic design regression and the bootstrap

    OpenAIRE

    Seijo, Emilio; Sen, Bodhisattva

    2011-01-01

    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...

  12. Generalizations of fuzzy linguistic control points in geometric design

    Science.gov (United States)

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

    2014-07-01

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

  13. Automated design of image operators that detect interest points.

    Science.gov (United States)

    Trujillo, Leonardo; Olague, Gustavo

    2008-01-01

    This work describes how evolutionary computation can be used to synthesize low-level image operators that detect interesting points on digital images. Interest point detection is an essential part of many modern computer vision systems that solve tasks such as object recognition, stereo correspondence, and image indexing, to name but a few. The design of the specialized operators is posed as an optimization/search problem that is solved with genetic programming (GP), a strategy still mostly unexplored by the computer vision community. The proposed approach automatically synthesizes operators that are competitive with state-of-the-art designs, taking into account an operator's geometric stability and the global separability of detected points during fitness evaluation. The GP search space is defined using simple primitive operations that are commonly found in point detectors proposed by the vision community. The experiments described in this paper extend previous results (Trujillo and Olague, 2006a,b) by presenting 15 new operators that were synthesized through the GP-based search. Some of the synthesized operators can be regarded as improved manmade designs because they employ well-known image processing techniques and achieve highly competitive performance. On the other hand, since the GP search also generates what can be considered as unconventional operators for point detection, these results provide a new perspective to feature extraction research. PMID:19053496

  14. Material for Point Design (final summary of DIME material)

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, Paul A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-02-25

    These slides summarize the motivation of the Defect Induced Mix Experiment (DIME) project, the “point design” of the Polar Direct Drive (PDD) version of the NIF separated reactant capsule, the experimental requirements, technical achievements, and some useful backup material. These slides are intended to provide much basic material in one convenient location and will hopefully be of some use for subsequent experimental projects.

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

    Science.gov (United States)

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

    2012-11-01

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

  16. Design and fabrication of a freeform microlens array for a compact large-field-of-view compound-eye camera.

    Science.gov (United States)

    Li, Lei; Yi, Allen Y

    2012-04-20

    In this research, a unique freeform microlens array was designed and fabricated for a compact compound-eye camera to achieve a large field of view. This microlens array has a field of view of 48°×48°, with a thickness of only 1.6 mm. The freeform microlens array resides on a flat substrate, and thus can be directly mounted to a commercial 2D image sensor. Freeform surfaces were used to design the microlens profiles, thus allowing the microlenses to steer and focus incident rays simultaneously. The profiles of the freeform microlenses were represented using extended polynomials, the coefficients of which were optimized using ZEMAX. To reduce crosstalk among neighboring channels, a micro aperture array was machined using high-speed micromilling. The molded microlens array was assembled with the micro aperture array, an adjustable fixture, and a board-level image sensor to form a compact compound-eye camera system. The imaging tests using the compound-eye camera showed that the unique freeform microlens array was capable of forming proper images, as suggested by design. The measured field of view of ±23.5° also matches the initial design and is considerably larger compared with most similar camera designs using conventional microlens arrays. To achieve low manufacturing cost without sacrificing image quality, the freeform microlens array was fabricated using a combination of ultraprecision diamond broaching and a microinjection molding process. PMID:22534888

  17. A superlinear interior points algorithm for engineering design optimization

    Science.gov (United States)

    Herskovits, J.; Asquier, J.

    1990-01-01

    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.

  18. Black Eye

    Science.gov (United States)

    ... after a head injury, it could signify a skull fracture or other serious injury. Next Page: Black Eye ... Most Infamous Eye Injuries in American Sports History - Eye M.D.-approved information from EyeSmart ...

  19. Computing Optimal Experimental Designs via Interior Point Method

    OpenAIRE

    Lu, Zhaosong; Pong, Ting Kei

    2010-01-01

    In this paper, we study optimal experimental design problems with a broad class of smooth convex optimality criteria, including the classical A-, D- and p th mean criterion. In particular, we propose an interior point (IP) method for them and establish its global convergence. Furthermore, by exploiting the structure of the Hessian matrix of the aforementioned optimality criteria, we derive an explicit formula for computing its rank. Using this result, we then show that the N...

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

    DEFF Research Database (Denmark)

    Bey, Niki; Lenau, Torben Anker

    1998-01-01

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

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

    Science.gov (United States)

    He, Binggao; An, Zhiyong

    2014-09-01

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

  2. Change-point in stochastic design regression and the bootstrap

    CERN Document Server

    Seijo, Emilio

    2011-01-01

    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.

  3. Fly's Eye

    International Nuclear Information System (INIS)

    The authors describe a high energy physics observatory, the Fly's Eye, designed to measure extensive air showers (EAS) in the energy range 1017-1021 eV via atmospheric fluorescence. Preliminary results are presented for the following measurements: (1) the high energy cosmic ray spectrum at 1017-1019 eV, (2) the total proton cross section sigma/sub pp/, (3) limits on the extra-galactic neutrino flux at 1020 eV

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

    DEFF Research Database (Denmark)

    Müller, Sabine; Neergaard, Helle

    2011-01-01

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

  5. Design of prototype two element optically stimulated luminescence dosimeter badge for eye lens monitoring

    International Nuclear Information System (INIS)

    A prototype two element eye lens dosimeter badge based on highly sensitive ?-Al2O3: C optically stimulated luminescence dosimeters (OSLDs) was designed and developed. The badge consists of a plastic card in which two thin ?-Al2O3: C optically stimulated luminescence (OSL) discs are placed. The OSLDs in the plastic card (when inserted into plastic cassette) are covered with energy compensation filters made up of 0.3 mm thick Cu and 1.35 mm thick Teflon discs positioned symmetrically on both sides of the dosimeter. The OSLD badge is useful for monitoring doses from photons and beta particles. In this paper, theoretical studies using Monte Carlo method as well as using the analytical technique have been performed to study the energy response of the bare ?-Al2O3: C based disc dosimeters. These dosimeter discs have been found to exhibit over-response by a factor of ? 3.4 at ? 33 keV photon energy, whereas, beyond 80 keV photon energy, the response is nearly energy independent. Studies have also been performed to find the energy response of the ?-Al2O3: C disc dosimeters under different metal filters, viz., Al, Cu, Sn etc., and under various thicknesses of Teflon. From theoretical simulations, it has been found that 0.3 mm thick Cu is sufficient to correct the over-response in lower energy region within acceptable limits. Further, Teflon disc (DuPont, USA found to be the optimized choice as filter for the second dosimeter disc. It is worth mentioning that the ratio of the response of the OSL disc under Teflon to that under Cu filter indicates average energy of X-ray photons and same is used to correct the over-response as well as to estimate the quantity Hp(3). Also for higher photon energy region, the readout of the dosimeter disc under Teflon filter directly measures the quantity Hp(3). Same holds true for beta particles having maximum beta energy, Emax beyond 0.7 MeV. (author)

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

    Science.gov (United States)

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

    2014-09-01

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

  7. Using Eye Tracking to Study on Attention and Recall in Multimedia Learning Environments: The Effects of Design in Learning

    Directory of Open Access Journals (Sweden)

    Servet Bayram

    2012-08-01

    Full Text Available In this study, the effect of multimedia learning environment prepared according to the attention types (focused - split on recall performances of learners with attention level (high - low was investigated by using eye movement measures. The participants were 37 undergraduate students who were presented with either focused attention or split attention multimedia learning environment. After attention levels of the learners were determined by d2 Test of Attention, they were separated to two groups as high and low. On the other hand, the instructional media were designed according to focused and split attention types. Multimedia in split attention type was applied to the half of the learners in groups determined with respect to attention level and multimedia in focused attention type was applied to the other half. Eye tracking (number of fixations, hetmap, dwell time data were collected during the study. Their recall performances were measured with recall tasks. After that, the researchers evaluated recall performances of all learners and eye movement measures. According to Two Way ANOVA test results, it seems that application of different multimedia applications in terms of attention type on the learners having different attention capacities has no significant effect on number of fixations. The multimedia applications prepared in different attention types to the learners has significant effect on number of fixations. Attention capacities of learners have no significant effect on number of fixation. According to eye tracking measurements, in the focused attention multimedia application, it seems that the learners look at the parts where they are supposed to focus on and the most videos are shown. On the other hand, it seems that the learners look at the parts that video, text and picture are shown together in split attention multimedia application. According to Independent Samples t-test results, recall performances of the learners show a significant difference according to multimedia applications on behalf of focused attention multimedia application.

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

    International Nuclear Information System (INIS)

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

  9. Aspherical optics design for minimal spherical aberration in vision correction of human eyes

    Science.gov (United States)

    Jiang, Min-shan; Lin, J. T.; Zhou, Chuan-qing; Ren, Qiu-shi

    2008-08-01

    Using raytracing method (ZEMAX program), the reduction of SA of the whole human eye may be reduced via the combined effects of asphericity (Q) and the ratio of the front and back surface of an IOL. The overall SA for best image quality may be defined by Q* when the image position off axis is reduced to that of the paraxial. Our calculations show the following general features: (1) For a give Q value, the influence on the SA is proportional to the surface power; (2) for minimal whole eye SA, negative Q is needed in IOL; (3) for a given IOL power, the Q* is smaller when the front surface has a smaller power. All above features derived from numerical raytracing method are consistent with analytic formulas.

  10. Eye Wear

    Science.gov (United States)

    ... require more careful handling. Many jobs and some sports carry a risk of eye injury. Thousands of children and adults get eye injuries every year. Most are preventable with proper eye protection. Everyone is at risk for eye damage from the sun year-round. It's important to ...

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

    Science.gov (United States)

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

    2013-03-01

    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.

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

    International Nuclear Information System (INIS)

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

  13. The Modular Point Design for Heavy Ion Fusion

    International Nuclear Information System (INIS)

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

  14. Teach Graphic Design Basics with PowerPoint

    Science.gov (United States)

    Lazaros, Edward J.; Spotts, Thomas H.

    2007-01-01

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

  15. Healthy Eyes

    Science.gov (United States)

    Healthy Vision Diabetes Diabetes Home How Much Do You Know? What You Should Know Protecting Against Vision ... de los Ojos Cómo hablarle a su oculista Healthy Eyes Listen Having a comprehensive dilated eye exam ...

  16. Eye emergencies

    Science.gov (United States)

    ... the eye may also occur. Certain types of skull fractures can cause bruising around the eyes, even without ... Working with toxic chemicals Cycling or participating in sports where there is a high likelihood of injury ...

  17. Eye Protection

    Science.gov (United States)

    ... eye protection equipment? Most farm supply and hardware retailers carry sunglasses, safety glasses, goggles and welding masks ... radiation can lead to the development of cataracts. Growths on parts of the eye and skin cancers ...

  18. Dry Eye

    Science.gov (United States)

    ... in thyroid disease when the eye protrudes forward; cosmetic surgery, if the eyelids are opened too widely. Frequently ... disease when the eye protrudes forward or after cosmetic surgery if the eyelids are opened too widely, dry ...

  19. 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 ...

  20. Design of three-mirror illumination system with free-form fly's eye for extreme ultraviolet lithography.

    Science.gov (United States)

    Mei, Qiuli; Li, Yanqiu

    2015-03-10

    The low source power is one of the major challenges that hinder the extreme ultraviolet lithography from high volume manufacturing. To alleviate the source development pressure, a high-efficiency illumination system with three mirrors is proposed, based on the authors' knowledge, for the first time. Free-form fly's eye is introduced into the system to get a qualified arc-shaped irradiance distribution on the reticle. A method integrated with a numerical method and optimization to design the free-form surface is given in detail. The transfer efficiency of the system is much higher than that of the four-mirror configuration employed in the EUV exposure platform. Compared with the previous high-efficiency illumination system with two mirrors, this configuration can ensure a good uniformity and will not increase the objective design difficulty or affect the image quality of the objective. Simulation result of the design with three mirrors shows the uniformity on the reticle is about 95.5%, and the energy efficiency is about 25.4%. It indicates that the system is effective in enhancing the efficiency and potential to promote the EUV lithography into high volume manufacturing. PMID:25968388

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

    Directory of Open Access Journals (Sweden)

    V.VINAY CHAMKUR , Chetana.R

    2012-06-01

    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.

  2. Optimization of the NIF ignition point design hohlraum

    Science.gov (United States)

    Callahan, D. A.; Hinkel, D. E.; Berger, R. L.; Divol, L.; Dixit, S. N.; Edwards, M. J.; Haan, S. W.; Jones, O. S.; Lindl, J. D.; Meezan, N. B.; Michel, P. A.; Pollaine, S. M.; Suter, L. J.; Town, R. P. J.; Bradley, P. A.

    2008-05-01

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

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

    DEFF Research Database (Denmark)

    Stefani, Alessio; Stecher, Matthias

    2012-01-01

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

  4. Point-by-point written fiber-Bragg gratings and their application in complex grating designs.

    Science.gov (United States)

    Marshall, Graham D; Williams, Robert J; Jovanovic, Nemanja; Steel, M J; Withford, Michael J

    2010-09-13

    The point-by-point technique of fabricating fibre-Bragg gratings using an ultrafast laser enables complete control of the position of each index modification that comprises the grating. By tailoring the local phase, amplitude and spacing of the grating's refractive index modulations it is possible to create gratings with complex transmission and reflection spectra. We report a series of grating structures that were realized by exploiting these flexibilities. Such structures include gratings with controlled bandwidth, and amplitude- and phase-modulated sampled (or superstructured) gratings. A model based on coupled-mode theory provides important insights into the manufacture of such gratings. Our approach offers a quick and easy method of producing complex, non-uniform grating structures in both fibres and other mono-mode waveguiding structures. PMID:20940876

  5. Design of Farthest-Point Masks for Image Halftoning

    Directory of Open Access Journals (Sweden)

    Ramponi G

    2004-01-01

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

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

    International Nuclear Information System (INIS)

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

  7. Amblyopia: Lazy Eye Treatment

    Science.gov (United States)

    ... Eyes & the Sun Eye Health News Consumer Alerts Amblyopia: Lazy Eye Treatment Tweet jllkjllj Lazy eye correction ... that the child’s visual system can develop properly. Amblyopia: What Is Lazy Eye? Amblyopia: Lazy Eye Symptoms ...

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

    Science.gov (United States)

    Fulcher, Jared Terrell

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

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

    Science.gov (United States)

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

    2006-01-01

    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.

  10. Simultaneous multi-design point approach to gas turbine on-design cycle analysis for aircraft engines

    Science.gov (United States)

    Schutte, Jeffrey Scott

    Gas turbine engines for aircraft applications are required to meet multiple performance and sizing requirements, subject to constraints established by the best available technology level, that are both directly and indirectly associated with the aerothermodynamic cycle. The performance requirements and limiting values of constraints that are considered by the cycle analyst conducting an engine cycle design occur at multiple operating conditions. The traditional approach to cycle analysis chooses a single design point with which to perform the on-design analysis. Additional requirements and constraints not transpiring at the design point must be evaluated in off-design analysis and therefore do not influence the cycle design. Such an approach makes it difficult to design the cycle to meet more than a few requirements and limits the number of different aerothermodynamic cycle designs that can reasonably be evaluated. Engine manufacturers have developed computational methods to create aerothermodynamic cycles that meet multiple requirements, but such methods are closely held secrets of their design process. This thesis presents a transparent and publicly available on-design cycle analysis method for gas turbine engines which generates aerothermodynamic cycles that simultaneously meet performance requirements and constraints at numerous design points. Such a method provides the cycle analyst the means to control all aspects of the aerothermodynamic cycle and provides the ability to parametrically create candidate engine cycles in greater numbers to comprehensively populate the cycle design space. The cycle design space represents all of the candidate engine cycles that meet the performance requirements for a particular application from which a "best" engine can be selected. This thesis develops the multi-design point on-design cycle analysis method labeled simultaneous MDP. The method is divided into three different phases resulting in an 11 step process to generate a cycle design space for a particular application. The first phase is the requirements and technology definition phase which defines the engine cycle problem to be analyzed through the establishment of requisite performance requirements and technology rules at the different design points and determines the overall engine architecture. The second phase is the MDP setup phase which establishes a set of nonlinear equations by formulating a system of nonlinear equations at on-design mode from design rules that couple the design points, performance requirements, technology rules and design variables. The key to the method is the understanding of the coupling of the performance between the different design points. The equations are divided into three categories; user defined equations specified by the cycle analyst based on the chosen design rules, engine component matching relations to ensure that conservation of mass and energy is maintained at each of the design points, and constraint relations which determine the feasibility of the candidate engines. The third phase is the MDP execution phase which populates the cycle design space by parametrically varying cycle design variables and then simultaneously finds the solution to the entire set of nonlinear equations with a modified version of the Newton-Raphson solver. For a specific cycle design problem, the first two phases are only performed once and the third phase repeated for each unique combination of design variables to create the cycle design space. Through implementation of simultaneous MDP, a comprehensive cycle design space can be created quickly for the most complex of cycle design problems. Furthermore, the process documents the creation of each candidate engine providing transparency as to how each engine cycle was designed to meet all of the requirements. The cycle analyst is intricately involved in the simultaneous MDP method using their knowledge and expertise in the first two phases to define and setup the cycle design space, but are removed from the more time consuming task of finding each

  11. Using eye-tracking methodology in consumer science

    DEFF Research Database (Denmark)

    Bialkova, S.; Mueller Loose, Simone

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

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

    Science.gov (United States)

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

    1999-01-01

    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.

  13. Eye Tracking

    Science.gov (United States)

    Science Update

    2002-05-27

    When we read, our eyes don't scan the lines at a constant speed. Rather, they move in fits and starts across the page, lingering on unfamiliar words and re-reading confusing phrases or sentences. In this Science Update, you'll hear how scientists can measure the way we process language by observing people's eye movements.

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

    OpenAIRE

    Uma Mageswar, D.; Selvavinayagam, G.

    2013-01-01

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

  15. Eye dilation

    Science.gov (United States)

    Greyson Orlando (None; )

    2006-12-11

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

  16. 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.

  17. Eye Injuries

    Science.gov (United States)

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

  18. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Torn Retina Diabetic Retinopathy Dry Eye Floaters & Flashes Glaucoma Hyperopia (Farsightedness) Low Vision Myopia (Nearsightedness) Pink Eye ( ... Remedies for Simple Eye Problems Medical Marijuana for Glaucoma Pregnancy Preventing Eye Injuries Smokers Sports Using Eye ...

  19. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Low Vision Myopia (Nearsightedness) Pink Eye (Conjunctivitis) Presbyopia (Aging Eye) Stye Uveitis/Iritis See all Diseases & Conditions > ... Diabetes Diet & Nutrition Eye Injuries Eye Screening Guidelines Home Remedies for Simple Eye Problems Medical Marijuana for ...

  20. 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 ... permanent loss of your eyelashes. Hold the Rib Eye Don’t put raw meat on a black ...

  1. Eye Injuries in Sports

    Science.gov (United States)

    MENU Return to Web version Eye Injuries in Sports Eye Injuries in Sports Which sports cause the most eye ... arts. What are the most common types of sports-related eye injuries? Common types of eye injuries are blunt trauma, ...

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

    OpenAIRE

    Elsa Jónsdóttir 1990

    2013-01-01

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

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

    Science.gov (United States)

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

    2014-09-01

    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 Npoints through one surface, the transition from two to three objet points obtained by increasing the parallelism, and getting to the designs of six surfaces imaging up to eight object points. These designs are limited with the condition that the surfaces cannot be placed at the aperture stop. 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.

  4. The design, commissioning and operation of Hinkley Point 'B' AGR power station pressure vessel insulation

    International Nuclear Information System (INIS)

    The paper describes the basic design of insulation as used at Hinkley Point 'B' Advanced Gas Cooled Reactor (AGR) Power Station, together with variations of the design to suit the requirements of the different areas of the reactor. Results of commissioning tests and modifications resulting therefrom are discussed. (author)

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

    OpenAIRE

    Lee, Yoong Hon; Parinduri, Rasyad

    2013-01-01

    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...

  6. Multi-point Adjoint-Based Design of Tilt-Rotors in a Noninertial Reference Frame

    Science.gov (United States)

    Jones, William T.; Nielsen, Eric J.; Lee-Rausch, Elizabeth M.; Acree, Cecil W.

    2014-01-01

    Optimization of tilt-rotor systems requires the consideration of performance at multiple design points. In the current study, an adjoint-based optimization of a tilt-rotor blade is considered. The optimization seeks to simultaneously maximize the rotorcraft figure of merit in hover and the propulsive efficiency in airplane-mode for a tilt-rotor system. The design is subject to minimum thrust constraints imposed at each design point. The rotor flowfields at each design point are cast as steady-state problems in a noninertial reference frame. Geometric design variables used in the study to control blade shape include: thickness, camber, twist, and taper represented by as many as 123 separate design variables. Performance weighting of each operational mode is considered in the formulation of the composite objective function, and a build up of increasing geometric degrees of freedom is used to isolate the impact of selected design variables. In all cases considered, the resulting designs successfully increase both the hover figure of merit and the airplane-mode propulsive efficiency for a rotor designed with classical techniques.

  7. LASIK - Laser Eye Surgery

    Medline Plus

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

  8. 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 Avoid Indoor Tanning ...

  9. 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 Protect Your Sight ...

  10. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During Pregnancy Computer Usage & Eye Strain Maintaining Your Sight with Diabetes Sports and Eye Protection Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Protect Your Sight Every Day Wear a ...

  11. Animals Eyes

    Science.gov (United States)

    Sohmer, Rachel.

    2002-01-01

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

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

    International Nuclear Information System (INIS)

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

  13. Eye and orbit ultrasound

    Science.gov (United States)

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

  14. Fuzzy Controller Design Using FPGA for Photovoltaic Maximum Power Point Tracking

    OpenAIRE

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

    2012-01-01

    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...

  15. Eigensensitivity in integrated design. [of earth-pointing satellite's control system

    Science.gov (United States)

    Kenny, Sean P.; Hou, Gene J.; Belvin, W. K.

    1990-01-01

    An application of eigensensitivity analysis to the control-structure integrated design process is presented with an emphasis placed on computational efficiency improvement of the overall design optimization process. The computational efficiency of eigenvalue/vector sensitivity analysis is demonstrated using the Earth Pointing Satellite in the context of a control-structure integrated design program. Results for a 2 percent design variable perturbation with and without the effects of the actuator mass show a 42 and 52 percent reduction in CPU time, respectively.

  16. Unbalanced and Minimal Point Equivalent Estimation Second-Order Split-Plot Designs

    Science.gov (United States)

    Parker, Peter A.; Kowalski, Scott M.; Vining, G. Geoffrey

    2007-01-01

    Restricting the randomization of hard-to-change factors in industrial experiments is often performed by employing a split-plot design structure. From an economic perspective, these designs minimize the experimental cost by reducing the number of resets of the hard-to- change factors. In this paper, unbalanced designs are considered for cases where the subplots are relatively expensive and the experimental apparatus accommodates an unequal number of runs per whole-plot. We provide construction methods for unbalanced second-order split- plot designs that possess the equivalence estimation optimality property, providing best linear unbiased estimates of the parameters; independent of the variance components. Unbalanced versions of the central composite and Box-Behnken designs are developed. For cases where the subplot cost approaches the whole-plot cost, minimal point designs are proposed and illustrated with a split-plot Notz design.

  17. Design and construction of a gallium fixed-point blackbody at CENAM

    Scientific Electronic Library Online (English)

    D., Cárdenas-García.

    2015-04-01

    Full Text Available For temperatures below silver fixed-point defined by the International Temperature Scale of 1990, a transfer radiation thermometer can be calibrated using either of two calibration schemes: a variable temperature blackbody with a standard platinum resistance thermometer as a reference, or with a set [...] of fixed-point blackbodies. CENAM is presently working with the first scheme, and it is developing fixed-point blackbodies to have the capability to work with the second scheme too. For this purpose a gallium fixed-point blackbody to calibrate CENAM's transfer radiation thermometer was designed and constructed. The blackbody cavity has a cylindro-cone shape with effective emissivity equal to 0.9992 ± 0.0004 in the 8 ?m to 14 ?m wavelength range. The radiance temperature of the gallium fixed-point blackbody was estimated to have an expanded uncertainty of 54 mK, with a coverage factor k = 2.

  18. Googly Eyes

    Science.gov (United States)

    Boss, Susan

    2009-01-01

    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.)

  19. Design and evaluation of aircraft heat source systems for use with high-freezing point fuels

    Science.gov (United States)

    Pasion, A. J.

    1979-01-01

    The objectives were the design, performance and economic analyses of practical aircraft fuel heating systems that would permit the use of high freezing-point fuels on long-range aircraft. Two hypothetical hydrocarbon fuels with freezing points of -29 C and -18 C were used to represent the variation from current day jet fuels. A Boeing 747-200 with JT9D-7/7A engines was used as the baseline aircraft. A 9300 Km mission was used as the mission length from which the heat requirements to maintain the fuel above its freezing point was based.

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

    Science.gov (United States)

    Johnson, C. D.

    1993-01-01

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

  1. Design and Implementation of Real-time Algorithms for Eye Tracking and PERCLOS Measurement for on board Estimation of Alertness of Drivers

    OpenAIRE

    George, Anjith; Routray, Aurobinda

    2015-01-01

    The alertness level of drivers can be estimated with the use of computer vision based methods. The level of fatigue can be found from the value of PERCLOS. It is the ratio of closed eye frames to the total frames processed. The main objective of the thesis is the design and implementation of real-time algorithms for measurement of PERCLOS. In this work we have developed a real-time system which is able to process the video onboard and to alarm the driver in case the driver i...

  2. 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 muscle ... term for crossed eyes is strabismus. Children most often ...

  3. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Dry Eye Floaters & Flashes Glaucoma Hyperopia (Farsightedness) Low Vision Myopia (Nearsightedness) Pink Eye (Conjunctivitis) Presbyopia (Aging Eye) ... Symptoms Blurriness Dark Curtain Dark Spots Discharge Double Vision Drooping Eyelid Eye Pain Eyelash Crusting Eyelid Lump ...

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

    OpenAIRE

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

    2014-01-01

    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 ...

  5. 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)

  6. Design Considerations for Miniaturized Control Moment Gyroscopes for Rapid Retargeting and Precision Pointing of Small Satellites

    Science.gov (United States)

    Patankar, Kunal; Fitz-Coy, Norman; Roithmayr, Carlos M.

    2014-01-01

    This paper presents the design as well as characterization of a practical control moment gyroscope (CMG) based attitude control system (ACS) for small satellites in the 15-20 kilogram mass range performing rapid retargeting and precision pointing maneuvers. The paper focuses on the approach taken in the design of miniaturized CMGs while considering the constraints imposed by the use of commercial off-the-shelf (COTS) components as well as the size of the satellite. It is shown that a hybrid mode is more suitable for COTS based moment exchange actuators; a mode that uses the torque amplification of CMGs for rapid retargeting and direct torque capabilities of the flywheel motors for precision pointing. A simulation is provided to demonstrate on-orbit slew and pointing performance.

  7. Fuzzy Controller Design Using FPGA for Photovoltaic Maximum Power Point Tracking

    Directory of Open Access Journals (Sweden)

    Basil M Hamed

    2012-06-01

    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.

  8. An integrated mechanical design concept for the final focusingregion for the HIF point design

    Energy Technology Data Exchange (ETDEWEB)

    Brown, T.; Sabbi, G.-L.; Barnard, J.J.; Heitzenroeder, P.; Chun,J.; Schmidt, J.; Yu, S.S.; Peterson, P.F.; Abbott, R.P.; Callahan, D.A.; Latkowski, J.F.; Logan, B.G.; Meier, W.R.; Pemberton, S.J.; Rose, D.V.; Sharp, W.M.; Welch, D.R.

    2002-11-21

    A design study was undertaken to develop a ''first cut'' integrated mechanical design concept of the final focusing region for a conceptual IFE power plant that considers the major issues which must be addressed in an integrated driver and chamber system. The conceptual design in this study requires a total of 120 beamlines located in two conical arrays attached on the sides of the target chamber 180 degrees apart. Each beamline consists of four large-aperture superconducting quadrupole magnets and a dipole magnet. The major interface issues include radiation shielding and thermal insulation of the superconducting magnets; reaction of electromagnetic loads between the quadrupoles; alignment of the magnets; isolation of the vacuum regions in the target chamber from the beamline, and assembly and maintenance.

  9. 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

  10. Eye Level

    Science.gov (United States)

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

  11. Web Design for Multiple Platforms in Microsoft SharePoint 2013

    OpenAIRE

    Claug, Erik

    2013-01-01

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

  12. Preliminary Fly's Eye results

    International Nuclear Information System (INIS)

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

  13. Preliminary fly's eye results

    International Nuclear Information System (INIS)

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

  14. Circuital model for the Maxwell Fish Eye perfect drain

    OpenAIRE

    Gonzalez, Juan C.; Grabovickic, Dejan; Minano, Juan C.; Benitez, Pablo

    2012-01-01

    Perfect drain for the Maxwell Fish Eye (MFE) is a non-magnetic dissipative region placed in the focal point to absorb all the incident radiation without reflection or scattering. The perfect drain was recently designed as a material with complex electrical permittivity that depends on frequency. However, this material is only a theoretical material, so it can not be used in practical devices. Recently, the perfect drain has been claimed as necessary to achieve super-resoluti...

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

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, W.H. (ed.)

    1979-12-01

    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.

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

    OpenAIRE

    Zierer, Klaus; Seel, Norbert M

    2012-01-01

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

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

    OpenAIRE

    Uma Maheswara Rao Ch, Bala Murali Krishna V.

    2014-01-01

    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.

  18. Design and development of a laminated glass-plastic Fresnel lens for point focus photovoltaic systems

    Energy Technology Data Exchange (ETDEWEB)

    Matalon, L. A.

    1982-08-01

    The design and development of a laminated glass-plastic Fresnel lens for point focus photovoltaic systems use is described. The objective of this development was to examine the feasibility of producing lenses with a cost effectiveness superior to that of lenses made by casting of acrylic. The procedure used in executing this development, the method used in cost effectiveness evaluation, results obtained and recommendations for further work are presented.

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

    Directory of Open Access Journals (Sweden)

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

    2014-05-01

    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.

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

    Directory of Open Access Journals (Sweden)

    P.Vishnu Kumar, Dr.T.JayaChandra Prasad

    2012-08-01

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

  1. Using Eye Makeup

    Science.gov (United States)

    ... Usage & Eye Strain Maintaining Your Sight with Diabetes Sports and Eye Protection Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Avoid Indoor Tanning Studies show UV exposure from tanning beds can cause eye damage and skin cancer. Not the look you're ...

  2. 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 ... have LASIK, it is important to keep a record of your pre-operation and post-operation eye ...

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

    Directory of Open Access Journals (Sweden)

    Atul Bhardwaj

    2013-12-01

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

  4. A parametric system study for the selection of RFP fusion reactor design point

    International Nuclear Information System (INIS)

    Based on simple physics, engineering, and economic models among various design parameters of reversed-field pinch (RFP) fusion reactors, a parametric system study program has been developed giving cost of electricity (COE) for a given set of design parameters or a set of design parameters giving the minimum COE. This program has been used extensively to select design points and evaluate the sensitivity of physics, engineering, economic and operational parameters in the REPUTER RFP fusion reactor design study effort. Several key features emerged from the study in relation to high power density RFP fusion reactors with solid breeder blanket. They are: 1. selection of normal conductor for TF and PF coils to reduce the thickness of radiation shielding, 2. selection of a total first wall loading of 18 MW/m2 considering the potential economic merit and nonlinear effects which might shorten the lifetime of the first wall, and 3. a maintenance policy of package replacement of the fusion power core, including TF coils, to significantly reduce maintenance time. The uncertainty range of COE was evaluated based on the sensitivity and uncertainty of design variables and parameters. The result warned us of the use of COE evaluated in this program for the purpose of comparison of economy with the result of other fusion system studies. (orig.)

  5. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... excimer laser preprogrammed with the patient's unique eye measurements is centered above the eye. The surgeon checks ... Eye M.D. the benefits and risks — including quality of life issues — that could result from correcting ...

  6. Down Syndrome: Eye Problems

    Science.gov (United States)

    ... 11/2013 Eye Terms & Conditions Most Common Searches Adult Strabismus Amblyopia Cataract Conjunctivitis Corneal Abrasions Dilating Eye Drops Lazy ... Screening Vision Screening Recommendations Loading... Most Common Searches Adult ... Abrasions Dilating Eye Drops Lazy ...

  7. Toxoplasmosis (and the Eye)

    Science.gov (United States)

    ... 03/2015 Eye Terms & Conditions Most Common Searches Adult Strabismus Amblyopia Cataract Conjunctivitis Corneal Abrasions Dilating Eye Drops Lazy ... Screening Vision Screening Recommendations Loading... Most Common Searches Adult ... Abrasions Dilating Eye Drops Lazy ...

  8. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... Topics Preventing Eye Injuries Healthy Eyes During Pregnancy Computer Usage & Eye Strain Maintaining Your Sight with Diabetes ... age 40, when the signs of disease and changes in vision may start to occur. Follow Us ...

  9. LASIK - Laser Eye Surgery

    Medline Plus

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

  10. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... Topics Preventing Eye Injuries Healthy Eyes During Pregnancy Computer Usage & Eye Strain Maintaining Your Sight with Diabetes ... surgery, how to choose a surgeon and an introduction to the informed consent process. LASIK Surgery: Why ...

  11. What Is Dry Eye?

    Medline Plus

    Full Text Available ... in Eye Flashes of Light Irritation Itchiness Light Sensitivity Red Eye Reduced Vision Tearing See all Symptoms > ... of tears in response to eye irritation or emotion. When a foreign body or dryness irritates the ...

  12. Eye Injuries at Home

    Science.gov (United States)

    ... Sun Eye Health News Consumer Alerts Eye Injuries at Home Tweet You might think that the family home ... the chore is being done. Preventing Eye Injuries at Home Wearing protective eyewear will prevent 90 percent of ...

  13. Crossed eyes (image)

    Science.gov (United States)

    People are very sensitive to other individuals' eye positions. By looking at another person's eye position, one can very effectively gauge where they are looking. People are also sensitive to eyes that are ...

  14. Measuring Software Functionality Using Function Point Method Based On Design Documentation

    Directory of Open Access Journals (Sweden)

    Anie Rose Irawati

    2012-05-01

    Full Text Available Estimated value of software as agreed by the end user and the developer team should be expressed in a certain magnitude, one of which is the measure of functionality. Function Point (FP Method is one of the methods used to obtain the size of the functionality and can be used to estimate cost, duration, and amount of resources required by a software project. However, Function Point measurement is not simple and requires expertise in software analysis. Furthermore, the results of the calculation are considered valid if it is verified by someone with International Function Point User Group (IFPUG certification. This research aims at designing and implementing a system that makes users convenient in analyzing software functionality size based on FP method referring to IFPUG CPM 4.3.1 standards. The system helps users to perform FP analysis in a faster and easier way without sacrificing accuracy. The input for the system is XMI document resulting from software design documentation derived from UML documents. The study also reveals that the more complete UML documents of the software in the project, the more accurate the FP calculation results obtained.

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

    Directory of Open Access Journals (Sweden)

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

    2012-09-01

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

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

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Morelli, Nicola

    2011-01-01

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

  17. Constrained LQR Design Using Interior-Point Arc-Search Method for Convex Quadratic Programming with Box Constraints

    OpenAIRE

    Yang, Yaguang

    2013-01-01

    Although the classical LQR design method has been very successful in real world engineering designs, in some cases, the classical design method needs modifications because of the saturation in actuators. This modified problem is sometimes called the constrained LQR design. For discrete systems, the constrained LQR design problem is equivalent to a convex quadratic programming problem with box constraints. We will show that the interior-point method is very efficient for this...

  18. Spacecraft and mission design for the precision optical INTerferometer in space (POINTS)

    Science.gov (United States)

    Schumaker, Bonny L.; Agronin, Michael L.; Chen, Gun-Shing; Ledeboer, W.; Melody, James W.; Noon, D.; Ulvestad, James S.

    1993-09-01

    This paper describes key features of the instrument, spacecraft, and mission design for the Precision Optical INTerferometer in Space (POINTS), which have evolved through studies at the Jet Propulsion Laboratory during the last few years. Design of the flight-system configuration has been driven by several considerations. Since the most ambitious science goals require access to a large portion of the sky most of the time, minimal systematic errors, and a 10-year mission life, a high Earth orbit (higher than 50,000 km) is preferred; the nominal has been taken to be a circular orbit of 100,000-km radius. In order to provide a very uniform thermal environment for the instrument, a solar shield supporting an array of solar cells is mounted on a boom and gimballed along two axes so as to remain pointed at the Sun and to provide constant shade for the entire spacecraft. Silicon cells covering about 85% of the roughly 4.8-m-diameter shield and operating at about 100 deg C could supply sufficient power for a 10-year mission life. A unibody design was selected in which the instrument and spacecraft bus are solidly attached to form a single rigid body. Full pointing freedom for the instrument is provided by articulation of the solar shield about two axes plus roll of the entire spacecraft around the Sun direction. With the high orbit and Sun-facing, geometrically simple spacecraft configuration, the effects of solar radiation pressure--the only significant external disturbance to spacecraft acceleration--can be modeled accurately enough to guarantee no compromise in the accurate velocity determination needed to correct astrometric measurements for stellar aberration.

  19. 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

  20. An interactive tool for design and support of lunar, gravity assist, and libration point trajectories

    Science.gov (United States)

    Carrico, J.; Schiff, C.; Roszman, L.; Hooper, H.; Folta, D.; Richon, K.

    1993-01-01

    The 'Swingby' interactive tool for design, analysis, and support of maneuver planning for missions that involve transfers to the moon, the lunar orbits, multiple-gravity assists, and the libration-point orbits, runs on a PC and uses pull-down and pop-up menus to allow users to change physical constants and select perturbations for inclusion. Swingby can also target by ascertain parameters, or allow the computer to generate goals on the basis of mission requirements. Rapid mission analyses, operational maneuvers, and contingency plans are thereby obtainable.

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

    Science.gov (United States)

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

    2004-01-01

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

  2. Dry Eye: an Inflammatory Ocular Disease

    OpenAIRE

    Hessen, Michelle; Akpek, Esen Karamursel

    2014-01-01

    Keratoconjunctivitis sicca, or dry eye, is a common ocular disease prompting millions of individuals to seek ophthalmological care. Regardless of the underlying etiology, dry eye has been shown to be associated with abnormalities in the pre-corneal tear film and subsequent inflammatory changes in the entire ocular surface including the adnexa, conjunctiva and cornea. Since the recognition of the role of inflammation in dry eye, a number of novel treatments have been investigated designed to i...

  3. Design and development of a hybrid tracker point focus fresnel passively cooled concentrator photovoltaic array

    Science.gov (United States)

    1983-11-01

    The design and development of an evolutionary concentrating photovoltaic array is described. The goal of this program was to develop a reliable PV concentrator array suitable for intermediate to central station power applications. The 9.4 kW array developed uses eighty passively cooled point focus Fresnel concentrator modules mounted onto a new tilt-roll tube tracker. A key feature of the technical approach was that commercial contractors were used in the design and fabrication of several of the critical subsystems: tracker structure, microprocessor based controller and silicon cell mounts. The aim of this approach has been to maximize the near term production potential of these critical array subsystems and components.

  4. Designing a sun-pointing Faraday cup for solar probe plus

    Science.gov (United States)

    Case, A. W.; Kasper, J. C.; Daigneau, P. S.; Caldwell, D.; Freeman, M.; Gauron, T.; Maruca, B. A.; Bookbinder, J.; Korreck, K. E.; Cirtain, J. W.; Effinger, M. E.; Halekas, J. S.; Larson, D. E.; Lazarus, A. J.; Stevens, M. L.; Taylor, E. R.; Wright, K. H., Jr.

    2013-06-01

    The NASA Solar Probe Plus (SPP) mission will be the first spacecraft to pass through the sub-Alfvénic solar corona. The objectives of the mission are to trace the flow of energy that heats and accelerates the solar corona and solar wind, to determine the structure and dynamics of the plasma and magnetic fields at the sources of the solar wind, and to explore mechanisms that accelerate and transport energetic particles. The Solar Wind Electrons, Alphas, and Protons (SWEAP) Investigation instrument suite on SPP will measure the bulk solar wind conditions in the inner heliosphere. SWEAP consists of the Solar Probe Cup (SPC), a sun-pointing Faraday Cup, and the Solar Probe ANalyzers (SPAN), a set of 3 electrostatic analyzers that will reside in the penumbra of SPP's thermal protection system and measure solar wind ions and electrons. SPP is scheduled to launch in 2018 into an equatorial solar orbit where a sequence of Venus gravity assists will gradually lower its closest solar approach to within 9.5 solar radii (RS) of the center of the Sun. The photon flux at 9.5 RS is more than 500 times greater than at 1 AU and therefore presents a design challenge for SPC, which will point directly at the Sun. SPC is derived from the Faraday cup instruments successfully flown on spacecraft from the beginning of the space age, but updated with high temperature materials to operate through the solar encounters. Current work includes both instrument design and the development of a testing approach capable of demonstrating adequate performance in encounter conditions. This paper will briefly discuss the suite as a whole, and then focus on the design and capabilities of SPC. We will also present the planned calibration and characterization of the instrument and the testing required to demonstrate the technological readiness of the design.

  5. 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 ...

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

    International Nuclear Information System (INIS)

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

  7. 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

  8. Eating for Your Eyes

    Science.gov (United States)

    Stastny, Sherri Nordstrom; Garden-Robinson, Julie

    2011-01-01

    An educational program targeting older adults was developed to increase knowledge regarding nutrition and eye health. With age, the chance for eye disease increases, so prevention is critical. The Eating for Your Eyes program has promoted behavior changes regarding eye health among the participants. This program is easily replicated and use is…

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

    DEFF Research Database (Denmark)

    Geert Jensen, Birgitte; Borup Lynggaard, Aviaja

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

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

    DEFF Research Database (Denmark)

    Maheshwari, Ram Krishan; Munk-Nielsen, Stig

    2013-01-01

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

  11. EyeC3D: 3D video eye tracking dataset

    OpenAIRE

    Hanhart, Philippe; Ebrahimi, Touradj

    2014-01-01

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

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

    Science.gov (United States)

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

    1999-01-01

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

  13. Design considerations of implementing a mobile wireless local area network : case stydy : “God´s eyes” video surveillance system

    OpenAIRE

    Zhang, Weichi

    2010-01-01

    Benefitting from the mobility of cellular network and broadband internet services of wireless network, people are demanding to access internet ubiquitously. The telecommunication operators are considering Wireless Local Area Network technology to be complementary to the third generation telecommunication technology. This thesis is aiming to discover the design considerations of implementing Mobile Wireless Local Area Network which is the integration of mobile telephone network and wireles...

  14. Surrogate end points in the design of immunotherapy trials: emerging lessons from type 1 diabetes.

    Science.gov (United States)

    Roep, Bart O; Peakman, Mark

    2010-02-01

    Approximately 5% of people in developed countries suffer from 1 of approximately 80 classified autoimmune diseases. The sheer scale of the clinical problem captures the interests of health policy makers, academics, funding bodies and pharmaceutical companies in equal measure. In recent decades, immunologists have gained a good understanding of disease pathogenesis, which has led to the development of various potential therapies. The next challenge is to establish which therapies have superior efficacy, sustainability and safety. Therapeutic trials that depend on clinical end points are long lasting and expensive. In this Opinion article we offer a perspective on the future of clinical trial design in which the process is significantly shortened by making greater use of laboratory measures to determine therapeutic outcome. PMID:20098462

  15. Lenses matching of compound eye for target positioning

    Science.gov (United States)

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

    2012-10-01

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

  16. "Delineamento duplo central composto com 29 pontos" Double central composite design with 29 points

    Directory of Open Access Journals (Sweden)

    Armando Conagin

    1979-01-01

    Full Text Available O delineamento duplo central composto com 29 pontos representa uma extensão do delineamento central composto e foi desenvolvido para o estudo de três fatores em mais de três níveis. Essencialmente, consta de dois fatoriais 2³ (níveis 1 e B, de duas estrelas (níveis a e 2alfa e de um ponto no centro do delineamento. É mostrada a origem do delineamento, o tipo não ortogonal, completamente casualizado, o tipo ortogonal completamente casualizado e o ortogonal divisível em dois blocos. No primeiro deles, seriam estudados três fatores em cinco níveis (-2, -1,-0, + 1 e +2; no segundo, três fatores em nove níveis (-3,02; -2,00; -1,51; -1,00; 0,00; + 1,00; +1,51; +2,00 e +3.02 e, no terceiro, três fatores nos nove níveis seguintes (-7,262; -4,391; -3,631; -1,000; 0,000; +1,000; +3,631; +4,391 e +7,262. É apresentado também um exemplo do último delineamento. com sua análise respectiva. De acordo com o critério de Box & Wilson (2, esse último delineamento é mais eficiente que o fatorial 3 x 3 x 3 divisível em blocos de nove. Os três delineamentos podem ser empregados em programas de adubação visando ao estudo de macronutrientes com vistas à recomendação das doses ótimas de fertilizantes que possibilitem a maximização do lucro obtido e, ainda, em outras áreas da pesquisa científica em que se deseja a avaliação da superfície de resposta, o estudo dos seus pontos extremos, etc.The double central composite design with 29 points rcpresents an extension of the central composite design and was developed for the study of three factors in more than three levels. Essentially it is composed of two 2³ factorials (levels 1 and B, of two stars (levels alpha and 2alpha and of one central point. In the present paper the origin of the design, the double central composite completely randomized not orthogonal in 5 levels (-2, -1, 0, +1 and +2, the completely randomized design, orthogonal, in nine levels (-3.02; -2.00; -1.51; -1.00; 0.00; + 1.00; +1.51; +2.00; +3.02 and the orthogonal design divided in two blocks (levels -7.262; -4.391; -3.631; -1.000; 0.000; +1.000; +3.631; +4.391 and +7.262 are shown. One example of the late design is presented with its correspondent analysis. According with Box and Wilson criterion, this last design is more efficient than the 3 x 3 x 3 factorial. They can be used in fertilizer programs aiming the most efficient economical recommendation of dosages and in other areas of scientific research in which we want to evaluate the surface response equations and its extremum properties looking at the maximum response.

  17. "Delineamento duplo central composto com 29 pontos" / Double central composite design with 29 points

    Scientific Electronic Library Online (English)

    Armando, Conagin; Joassy de Paula Neves, Jorge.

    Full Text Available O delineamento duplo central composto com 29 pontos representa uma extensão do delineamento central composto e foi desenvolvido para o estudo de três fatores em mais de três níveis. Essencialmente, consta de dois fatoriais 2³ (níveis 1 e B), de duas estrelas (níveis a e 2alfa) e de um ponto no centr [...] o do delineamento. É mostrada a origem do delineamento, o tipo não ortogonal, completamente casualizado, o tipo ortogonal completamente casualizado e o ortogonal divisível em dois blocos. No primeiro deles, seriam estudados três fatores em cinco níveis (-2, -1,-0, + 1 e +2); no segundo, três fatores em nove níveis (-3,02; -2,00; -1,51; -1,00; 0,00; + 1,00; +1,51; +2,00 e +3.02) e, no terceiro, três fatores nos nove níveis seguintes (-7,262; -4,391; -3,631; -1,000; 0,000; +1,000; +3,631; +4,391 e +7,262). É apresentado também um exemplo do último delineamento. com sua análise respectiva. De acordo com o critério de Box & Wilson (2), esse último delineamento é mais eficiente que o fatorial 3 x 3 x 3 divisível em blocos de nove. Os três delineamentos podem ser empregados em programas de adubação visando ao estudo de macronutrientes com vistas à recomendação das doses ótimas de fertilizantes que possibilitem a maximização do lucro obtido e, ainda, em outras áreas da pesquisa científica em que se deseja a avaliação da superfície de resposta, o estudo dos seus pontos extremos, etc. Abstract in english The double central composite design with 29 points rcpresents an extension of the central composite design and was developed for the study of three factors in more than three levels. Essentially it is composed of two 2³ factorials (levels 1 and B), of two stars (levels alpha and 2alpha) and of one c [...] entral point. In the present paper the origin of the design, the double central composite completely randomized not orthogonal in 5 levels (-2, -1, 0, +1 and +2), the completely randomized design, orthogonal, in nine levels (-3.02; -2.00; -1.51; -1.00; 0.00; + 1.00; +1.51; +2.00; +3.02) and the orthogonal design divided in two blocks (levels -7.262; -4.391; -3.631; -1.000; 0.000; +1.000; +3.631; +4.391 and +7.262) are shown. One example of the late design is presented with its correspondent analysis. According with Box and Wilson criterion, this last design is more efficient than the 3 x 3 x 3 factorial. They can be used in fertilizer programs aiming the most efficient economical recommendation of dosages and in other areas of scientific research in which we want to evaluate the surface response equations and its extremum properties looking at the maximum response.

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

    CERN Document Server

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

    2015-01-01

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

  19. Design, Results, Evolution and Status of the ATLAS Simulation at Point1 Project

    CERN Document Server

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

    2015-01-01

    Abstract. During the LHC Long Shutdown 1 period (LS1), that started in 2013, the Simulation at Point1 (Sim@P1) Project takes advantage, in an opportunistic way, of the TDAQ (Trigger and Data Acquisition) HLT (High Level Trigger) farm of the ATLAS experiment. This farm provides more than 1300 compute nodes, which are particularly suited for running event generation and Monte Carlo production jobs that are mostly CPU and not I/O bound. It is capable of running up to 2700 virtual machines (VMs) provided with 8 CPU cores each, for a total of up to 22000 parallel running jobs. This contribution gives a review of the design, the results, and the evolution of the Sim@P1 Project; operating a large scale OpenStack based virtualized platform deployed on top of the ATLAS TDAQ HLT farm computing resources. During LS1, Sim@P1 was one of the most productive ATLAS sites: it delivered more than 50 million CPU-hours and it generated more than 1.7 billion Monte Carlo events to various analysis communities. The design aspects a...

  20. Analysis of turbine stator adjustment required for compressor design-point operation in high Mach number supersonic turbojet engines

    Science.gov (United States)

    English, Robert E; Cavicchi, Richard H

    1953-01-01

    For turbojet engines designed for flight Mach numbers of 2.5 and 3.0, use of turbine stator adjustment to maintain compressor design-point operation was evaluated analytically to determine the effect on the aerodynamics of the turbine. Since the effect of turbine stator adjustment is to make the turbine design sensitive to the particular engine design conditions selected, in some cases the turbine must be conservatively designed for the high-speed flight condition to assure satisfactory turbine performance at take-off. A new concept, the break-even point, is introduced to provide quick evaluation of the proximity of turbines to the blade-loading limit at any off-design operation.

  1. What Is Dry Eye?

    Medline Plus

    Full Text Available ... large volume of tears, overwhelming the tear drainage system. These excess tears then overflow from your eye. Next Page: Causes of Dry ... from EyeSmart Related Answers Is it true that ...

  2. What Is Dry Eye?

    Medline Plus

    Full Text Available ... to Z Age-related Macular Degeneration (AMD) Allergies Amblyopia (Lazy Eye) Astigmatism Bacterial Keratitis Bell's Palsy Blepharitis ... Refractive Surgery & LASIK Sunglasses Living EyeSmart About Ophthalmologists Adults Under 40 Adults 40 to 60 Adults Over ...

  3. LASIK - Laser Eye Surgery

    Medline Plus

    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 ...

  4. Smoking and Eye Health

    Science.gov (United States)

    ... to Z Age-related Macular Degeneration (AMD) Allergies Amblyopia (Lazy Eye) Astigmatism Bacterial Keratitis Bell's Palsy Blepharitis ... Refractive Surgery & LASIK Sunglasses Living EyeSmart About Ophthalmologists Adults Under 40 Adults 40 to 60 Adults Over ...

  5. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... Eye Don’t put raw meat on a black eye because the bacteria can cause infection. Use ... it is removed, vision appears dim or goes black. Once the cornea is flattened, a hinged flap ...

  6. LASIK - Laser Eye Surgery

    Medline Plus

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

  7. LASIK - Laser Eye Surgery

    Medline Plus

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

  8. LASIK - Laser Eye Surgery

    Medline Plus

    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 ...

  9. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Eye) Astigmatism Bacterial Keratitis Bell's Palsy Blepharitis Cataracts Contact Lens-Related Infections Detached & Torn Retina Diabetic Retinopathy ... Eye Reduced Vision Tearing See all Symptoms > Glasses, Contacts & LASIK Contact Lenses Colored Contact Lenses Eyeglasses IOLs ...

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

    Science.gov (United States)

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

    2014-06-01

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

  11. Anatomy of the Eye

    Science.gov (United States)

    ... of the eye is located directly behind the pupil. The lens bends light coming into the eye to help ... occurs. Viteous: The vitreous cavity lies between the lens and ... the eye through the pupil and passes through the vitreous to be projected ...

  12. 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 ...

  13. Eye Movements and Learning.

    Science.gov (United States)

    Nesbit, Larry L.

    Research on the use of eye movement indices (such as number of fixations, the average fixation duration, and saccadic movements) as a measure of cognitive processing is reviewed in this paper. Information is provided on the physiology of the eye, computer applications to eye movement study, the influence of stimulus materials and intelligence on…

  14. What Is Dry Eye?

    Medline Plus

    Full Text Available ... GetEyeSmart.org Diseases & Conditions A to Z Age-related Macular Degeneration (AMD) Allergies Amblyopia (Lazy Eye) Astigmatism Bacterial Keratitis Bell's Palsy Blepharitis Cataracts Contact Lens-Related Infections Detached & Torn Retina Diabetic Retinopathy Dry Eye ...

  15. Strabismus (Crossed Eyes)

    Science.gov (United States)

    ... may create double vision and confusion, but over time the brain will learn to ignore the image from the turned eye. If the eye turning becomes constant and is not treated, it can lead to permanent reduction of vision in one eye, a condition called ...

  16. Genetic Testing and Eye Disease

    Science.gov (United States)

    ... Eye Health News Consumer Alerts In Focus: Genetic Testing and Eye Disease Tweet Eye Health Lifestyle Topics ... History of Eye Disease, Do You Need Genetic Testing? Thanks to news coverage, many people know that ...

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Prausnitz, J.M.

    1980-05-01

    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.

  19. Comparison of the most common HRV computation algorithms from the systems designer point of view.

    Science.gov (United States)

    Manis, G

    2009-01-01

    In this paper we examine the most commonly used algorithms for the computation of heart rate variability as well as some other interesting approaches. The aim of the paper is to study the problem from a different point of view, that of the systems designer. The selected algorithms are compared to each other through experimental analysis and theoretical study. The comparison criteria are efficiency, complexity, size of the object code, memory requirements, power consumption, parallel complexity and speedup achieved, ability to response in real time, simplicity of the interface and implementation in hardware. The motivation is strong since heart rate variability is an interesting problem which finds application not only in conventional computing systems, but also in small, even wearable devices implemented using embedded systems technology or directly in hardware. The computation of heart rate variability for a set of signal recordings and the classification achieved for these signals with each examined method are also presented. Signals have been recorded from young and elderly subjects and the examined methods are used to classify them into these two distinct groups. PMID:19205990

  20. Dyslexic and normal readers' eye movements

    OpenAIRE

    Olson, Richard K.; Kliegl, Reinhold; Davidson, Brian J.

    1983-01-01

    Dyslexic and normal readers' eye movements were compared while tracking a moving fixation point and in reading. Contrary to previous reports, the dyslexic and normal readers did not differ in their number of saccades, percentage of regressions, or stability of fixations in the tracking task. Thus, defective oculomotor control was not associated with or a causal factor in dyslexia, and the dyslexics' abnormal eye movements in reading must be related to differences in higher cognitive processes...

  1. Poverty and Eye Health

    Directory of Open Access Journals (Sweden)

    Jyoti Jaggernath

    2014-07-01

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

  2. Thyroid Eye Disease: Protruding, Irritated Eyes

    Science.gov (United States)

    ... be possible to completely eliminate all of the consequences of thyroid eye disease, surgery to correct these conditions is generally successful in satisfactorily restoring function, comfort, and cosmetic appearance. Who performs the surgery? Patients are most ...

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

    Directory of Open Access Journals (Sweden)

    Gene Frantz

    2007-01-01

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

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

    OpenAIRE

    Mayank Sharma,; Prince Nagar,; Ghanshyam Kumar Singh; Ram Mohan Mehra

    2013-01-01

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

  5. 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

  6. The Utah Fly's Eye detector

    International Nuclear Information System (INIS)

    We report the details of the design, operation and performance of the University of Utah Fly's Eye detector which was built to record the passage of ultra-high energy cosmic rays through the atmosphere via atmospheric fluorescence. Emphasized in the presentation are (1) light production by charged particles in the atmosphere, (2) kinematics of an EAS as seen by the Fly's Eye, (3) signal to noise considerations and its impact on detector design, (4) details of detector hardware and software, (5) detector calibration, (6) techniques employed in measurement of shower longitudinal development profiles and primary particle energy, and (7) assessment of detector performance by a comparison of Monte Carlo and real data distributions. (orig.)

  7. The design of multi-point temperature and humidity measurement system based on ZigBee technology

    International Nuclear Information System (INIS)

    According to the need of humiture real-time monitoring in warehousing management and Geological nuclear instruments, the design adopts ZigBee wireless communications, uses c8051f320 as the core, combines the digital temperature and humidity sensor SHT10, takes OLED as the display interface and at last it designed one multi-point temperature and humidity measurement system. It has the advantages such as low power consumption, small size and easy to operate ect. It introduced the system constitution, work principle, selection of hardware and design of software. (authors)

  8. Design and realization of a handheld vibrometer system for noncontact in-vivo detection of microvibrations of the human eye to determine the intraocular pressure (IOP)

    Science.gov (United States)

    Gundlach, Arnd; Rawer, Rainer; Hey, Stefan; Stork, Wilhelm; Mueller-Glaser, Klaus-Dieter

    2002-06-01

    To allow measurements of the intraocular pressure (IOP) by glaucoma patients themselves (self-tonometry) a handheld-interferometer system for non-contact in vivo measurements of microvibrations of the human eye was realized. The measurement principle is based on the dependence of the resonance frequencies of the human eye on the IOP. To analyze this, the human eye is stimulated by ultrasonic waves and the induced microvibrations are measured with a vibrometer and processed by a DSP unit. Beside a stabilized diode laser and a low noise photodetector an exact three-dimensional positioning system had to be developed to guarantee reliable measurements. To investigate the corresponding requirements a camera-based system for the detection of human eye movements was developed and test series with several persons were made. Based on these results an adjustment unit was integrated in a miniaturized interferometer system: After a short self-adjusting procedure lateral to the setup by overlaying two targets of a highly sensitive optical system the correct measuring distance between the cornea and the vibrometer parallel to the optical axis is determined automatically by an astigmatic auto-focus system. With this handheld-vibrometer in vivo measurements with several test persons were made with very good results concerning the reliability and handling capability.

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

    Scientific Electronic Library Online (English)

    Marina Storani de, Almeida; Luis Alberto, Carvalho.

    2007-06-01

    Full Text Available 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.

  10. Teamwork for eye care

    Directory of Open Access Journals (Sweden)

    M Babar Qureshi

    2014-04-01

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

  11. EYE BASED CONTROL SYSTEM

    OpenAIRE

    Shrunkhala Satish Wankhede, Ms. S. A. Chhabria

    2012-01-01

    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...

  12. Teamwork for eye care

    OpenAIRE

    Babar Qureshi, M.

    2014-01-01

    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.

  13. Eye movement tics.

    OpenAIRE

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

    1992-01-01

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

  14. A CAREM reactor's design evaluation from the nuclear security point of view

    International Nuclear Information System (INIS)

    The main objective of this work is to define the adequate rules for CAREM reactor security systems design and processes which aim to assure verification of the CALIN regulations 'Radiological Criteria' in relation to accidents concerning CAREM reactor design. (Author)

  15. Minimal plus one point designs for testing lack of fit for some sigmoid curve models.

    Science.gov (United States)

    Su, Ying; Raghavarao, Damaraju

    2013-03-11

    D-optimal designs for nonlinear models are often minimally supported. They have been frequently criticized for their inability to test for lack of fit. We construct alternative designs to address this issue for some commonly used sigmoid curves, including logistic, probit, and Gompertz models with two, three, or four parameters. For each model, we compare five nonminimally supported designs in terms of their efficiency, and propose designs that are both statistically efficient and practically convenient for practitioners. PMID:23437939

  16. Design of robust line-of-sight pointing control system for the SCOLE configuration

    Science.gov (United States)

    Joshi, S. M.; Armstrong, E. S.

    1987-01-01

    Robust compensator design for attitude control of the Spacecraft Control Laboratory Experiment (SCOLE) configuration is considered. A loop-shaping procedure similar to that used in the LQG/LTR method is used to iteratively design the compensator. A satisfactory compensator is obtained by including the rigid modes and three elastic modes in the design model.

  17. Measuring Software Functionality Using Function Point Method Based On Design Documentation

    OpenAIRE

    Anie Rose Irawati; Khabib Mustofa

    2012-01-01

    Estimated value of software as agreed by the end user and the developer team should be expressed in a certain magnitude, one of which is the measure of functionality. Function Point (FP) Method is one of the methods used to obtain the size of the functionality and can be used to estimate cost, duration, and amount of resources required by a software project. However, Function Point measurement is not simple and requires expertise in software analysis. Furthermore, the results of the calculati...

  18. Accommodation-dependent model of the human eye with aspherics

    OpenAIRE

    Navarro, Rafael; Santamaría, Javier; Bescós, J.

    1985-01-01

    We consider a schematic human eye with four centered aspheric surfaces. We show that by introducing recent experimental average measurements of cornea and lens into the Gullstrand-Le Grand model, the average spherical aberration of the actual eye is predicted without any shape fitting. The chromatic dispersions are adjusted to fit the experimentally observed chromatic aberration of the eye. The polychromatic point-spread function and modulation transfer function are calculated for...

  19. Design of sampling locations for river water quality monitoring considering seasonal variation of point and diffuse pollution loads.

    Science.gov (United States)

    Varekar, Vikas; Karmakar, Subhankar; Jha, Ramakar; Ghosh, N C

    2015-06-01

    The design of a water quality monitoring network (WQMN) is a complicated decision-making process because each sampling involves high installation, operational, and maintenance costs. Therefore, data with the highest information content should be collected. The effect of seasonal variation in point and diffuse pollution loadings on river water quality may have a significant impact on the optimal selection of sampling locations, but this possible effect has never been addressed in the evaluation and design of monitoring networks. The present study proposes a systematic approach for siting an optimal number and location of river water quality sampling stations based on seasonal or monsoonal variations in both point and diffuse pollution loadings. The proposed approach conceptualizes water quality monitoring as a two-stage process; the first stage of which is to consider all potential water quality sampling sites, selected based on the existing guidelines or frameworks, and the locations of both point and diffuse pollution sources. The monitoring at all sampling sites thus identified should be continued for an adequate period of time to account for the effect of the monsoon season. In the second stage, the monitoring network is then designed separately for monsoon and non-monsoon periods by optimizing the number and locations of sampling sites, using a modified Sanders approach. The impacts of human interventions on the design of the sampling net are quantified geospatially by estimating diffuse pollution loads and verified with land use map. To demonstrate the proposed methodology, the Kali River basin in the western Uttar Pradesh state of India was selected as a study area. The final design suggests consequential pre- and post-monsoonal changes in the location and priority of water quality monitoring stations based on the seasonal variation of point and diffuse pollution loadings. PMID:26009158

  20. A Self-Calibrating, Camera-Based Eye Tracker for the Recording of Rodent Eye Movements

    OpenAIRE

    DavideZoccolan; DavidD Cox

    2010-01-01

    Much of neurophysiology and vision science relies on careful measurement of a human or animal subject's gaze direction. Video-based eye trackers have emerged as an especially popular option for gaze tracking, because they are easy to use and are completely non-invasive. However, video eye trackers typically require a calibration procedure in which the subject must look at a series of points at known gaze angles. While it is possible to rely on innate orienting behaviors for calibration in som...

  1. Eye-Tracking

    Directory of Open Access Journals (Sweden)

    Gabriela GROSSECK

    2006-01-01

    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.

  2. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... close-up focusing power. How the LASIK procedure works LASIK is performed while the patient reclines under ... should discuss with your Eye M.D. the benefits and risks — including quality of life issues — that could result from correcting vision with ... about eye health and preserving your vision. Privacy Policy Email address

  3. Eye Injuries (For Parents)

    Science.gov (United States)

    ... the eye nausea or vomiting after an eye injury Think Prevention! Kids who play sports should wear protective goggles or unbreakable glasses as needed. Keep chemicals and other potentially dangerous objects out of the reach of children. Reviewed by: Steven Dowshen, MD Date ... Injuries First Aid: Pinkeye Pinkeye (Conjunctivitis) Corneal Abrasions A ...

  4. 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 What Is a Pinguecula and a Pterygium (Surfer's ...

  5. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... surgeon and an introduction to the informed consent process. LASIK Surgery: Why All Patients Need the K Card (PDF 650K) If you have decide to have LASIK, it is important to keep a record of your pre-operation and post-operation eye information. Your Eye M.D. may need this information ...

  6. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Free Newsletter Get eye MD-reviewed tips and information about eye health and preserving your vision. Privacy ... or images from this website is strictly prohibited by US and international copyright law. You may link from your website to any ...

  7. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... right eye care provider for your condition or treatment. Are You Fit at 40? A baseline eye exam is recommended at age 40, when the signs of disease and changes in vision may start to occur. Follow Us LASIK (laser-assisted in situ keratomileusis) is an outpatient refractive ...

  8. Eye-Tracking

    OpenAIRE

    Grosseck, Gabriela

    2006-01-01

    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.

  9. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Free Newsletter Get eye MD-reviewed tips and information about eye health and preserving your vision. ... or images from this website is strictly prohibited by US and international copyright law. You may link from your website to any ...

  10. Healthy Eyes, Healthy Body

    Science.gov (United States)

    ... 1: Can You Name the Parts of the Eye? Chapter 2. Eating Right Key Concepts: Vitamins Minerals What Else Should I Eat? Activity #2: Can You See a Vitamin? Activity #3: Let’s Eat Some Vitamins! Chapter 3. Exercise Helps Your Eyes Key Concepts: What Kind of Exercise? Protect Your ...

  11. Translation of Stem Cell Research: Points to Consider in Designing Preclinical Animal Studies

    OpenAIRE

    Frey-vasconcells, Joyce; Whittlesey, Kevin J.; Baum, Elona; Feigal, Ellen G.

    2012-01-01

    This article outlines important parameters to guide the design of preclinical studies for stem cell-based therapeutics and reviews the types of preclinical studies that should be considered. Considerations in the design and execution of specific studies to monitor the efficacy, toxicity, biodistribution, and tumorigenicity of stem cell-based therapeutics are also discussed.

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

    Science.gov (United States)

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

    2014-01-01

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

  13. If I Had - Dry Eyes

    Medline Plus

    Full Text Available ... Spotlight If I Had... Universities and Hospitals By Disease or Symptom View QuickTime Video Talk About This ... to specifically look for evidence of dry eye disease. What causes dry eye? Dr. Asbell: Dry eye ...

  14. Conjunctivitis: What Is Pink Eye?

    Science.gov (United States)

    ... in one or both eyes. There are three types of conjunctivitis: Bacterial conjunctivitis This is a highly contagious form of pink eye caused by bacterial infections. This type of conjunctivitis usually causes a red eye with a lot ...

  15. Childhood Eye Diseases and Conditions

    Science.gov (United States)

    ... Six Ways Measles Can Affect the Eyes Three Toys to Avoid - Eye M.D.-approved information from ... Academy of Ophthalmology medical disclaimer privacy policy sponsorship & advertising policies about us Educational Resources EyeWiki contact us ...

  16. Design of piping fixed points in the thorium high-temperature reactor (THTR)

    International Nuclear Information System (INIS)

    The boundary conditions of fixed-point construction in the pipelines of the THTR, Hamm-Uentrop, are discussed. Particular regard was paid to the loads on the headers and their supports. For the case of transverse fracture, the loads on the supports and on the header were determined using a single-mass resonator model. Three different points of rupture were assumed. For the case of longitudinal fracture, the calculation of support loads and header loads is explained, and the support loads and maximum bending moments are presented in a diagram as a function of time. (orig.)

  17. Experience Feedback of Current LWR on the Design and Operation of Advanced LWR, under the Safety Analysis Point of View

    International Nuclear Information System (INIS)

    Current LWR are operating with an excellent safety record. It is foreseen that they will be progressively replaced by more advanced designs (Generation III, III+, and IV). This paper reviews the role of the safety analysis, both in steady and transient state, in the flexible yet safe operation of the nuclear power plants. Several aspects such as licensing, technological progress, efficiency, public opinion and environmental consideration, and generation replacement, are considered form a broad perspective. Besides, deficiencies, learned lessons and design and operation aspects that could be improved in the new reactor fleet, under the perspective of safety analysis, are also considered from the engineering point of view and experience. (author)

  18. 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.)

  19. Eye Tracking Studies of Normative and Atypical Development

    Science.gov (United States)

    Karatekin, Canan

    2007-01-01

    This paper reviews the use of eye tracking measures (saccades, smooth-pursuit eye movements, fixations during scene and face perception, and pupillary dilation) to study typical and clinical populations of children and adolescents and evaluates the use of these measures. The studies are evaluated with a focus on points that may be of general…

  20. An Experimental Design for Examining Thermoregulatory Set Points in Ectothermic Animals.

    Science.gov (United States)

    Kingsbury, Bruce A.

    1999-01-01

    Provides a protocol for examining the mechanisms of animal thermoregulation in a straightforward but more sophisticated manner than using a thermal gradient. Describes a methodology for conducting operant conditioning to examine thermal set points for ectothermic animals. Contains 20 references. (WRM)

  1. 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.

  2. Binocular eye orientation during fixations: Listing's law extended to include eye vergence.

    Science.gov (United States)

    Van Rijn, L J; Van den Berg, A V

    1993-01-01

    Any eye position can be reached from a position called the primary position by rotation about a single axis. Listing's law states that for targets at optical infinity all rotation axes form a plane; the so-called Listing plane. Listing's law is not valid for fixation of nearby targets. To document these deviations of Listing's law we studied binocular eye positions during fixations of point targets in the dark. We tested both symmetric (targets in a sagittal plane) and asymmetric vergence conditions. For upward fixation both eyes showed intorsion relative to the position that would have been taken if each eye followed Listing's law. For downward fixation we found extorsion. The in- or extorsion increased approximately linearly with the vergence angle. The direction of the Listing axis and the turn angle about this axis can be described by rotation vectors. Our observations indicate that for fixation of nearby targets the rotation vectors of the two eyes become different and are no longer located in a single plane. However, we find that it is possible to decomose the rotation vector of each eye into the sum of a symmetric and an anti-symmetric part, each with its own properties. (1) The symmetric part is associated with eye version. This component of the rotation vector is identical for both eyes and lies in Listing's plane. In contrast to the classical form of Listing's law, this part of the rotation vector lies in Listing's plane irrespective of the fixation distance. (2) The anti-symmetric part of the rotation vector is related to eye vergence. This component is of equal magnitude but oppositely directed in each eye. The anti-symmetric part lies in the mid-sagittal plane, also irrespective of fixation distance. For fixation of targets at optical infinity the anti-symmetric part equals zero and the eye positions obey the classical form of Listing's law. Thus, the symmetric and anti-symmetric parts of the rotation vectors are restricted to two perpendicular planes. Combining these restrictions in a model, with the additional restriction that the vertical vergence equals zero during fixation of point targets, we arrive at the prediction that the cyclovergence is proportional to the product of elevation and horizontal vergence angles. This was well born out by the data. The model allows to describe the binocular eye position for fixation of any target position in terms of the bipolar coordinates of the target only (i.e. using only three degrees of freedom instead of the six needed for two eyes). PMID:8351841

  3. Space Mission Design in the Vicinity of Small Bodies and Libration Points Project

    National Aeronautics and Space Administration — To address NASA's need for applying advanced dynamical theories to space mission design and analysis, especially in the context of unstable orbital trajectories in...

  4. Data eye monitor method and apparatus

    Science.gov (United States)

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

    2012-01-31

    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.

  5. Perceptions of eye health in schools in Pakistan

    Directory of Open Access Journals (Sweden)

    Qureshi Mohammad

    2006-03-01

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

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

    International Nuclear Information System (INIS)

    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 rehe 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-08-01

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

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

    OpenAIRE

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

    2011-01-01

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

  9. Design and process development of a photonic crystal polymer biosensor for point of care diagnostics

    OpenAIRE

    JOHNSON, N; De La Rue, R.M.; Sharp, G; Lahiri, B.

    2011-01-01

    In this work, we report advances in the fabrication and anticipated performance of a polymer biosensor photonic chip developed in the European Union project P3SENS (FP7-ICT4-248304). Due to the low cost requirements of point-ofcare applications, the photonic chip is fabricated from nanocomposite polymeric materials, using highly scalable nanoimprint-lithography (NIL). A suitable microfluidic structure transporting the analyte solutions to the sensor area is alsofabricated in polymer and ad...

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

    OpenAIRE

    Saso Koceski; Natasa Koceska; Ivica Kocev

    2012-01-01

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

  11. Personal identification by eyes.

    Science.gov (United States)

    Marinovi?, Dunja; Njiri?, Sanja; Coklo, Miran; Muzi?, Vedrana

    2011-09-01

    Identification of persons through the eyes is in the field of biometrical science. Many security systems are based on biometric methods of personal identification, to determine whether a person is presenting itself truly. The human eye contains an extremely large number of individual characteristics that make it particularly suitable for the process of identifying a person. Today, the eye is considered to be one of the most reliable body parts for human identification. Systems using iris recognition are among the most secure biometric systems. PMID:22220469

  12. Eye and orbital cancer

    International Nuclear Information System (INIS)

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

  13. Changes in eye protection behavior following an occupational eye injury.

    Science.gov (United States)

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

    2012-09-01

    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 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

  14. Overcoming Presbyopia by Manipulating the Eyes' Optics

    Science.gov (United States)

    Zheleznyak, Leonard A.

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

  15. If I Had - A Red Eye from Contact Lens Use

    Medline Plus

    Full Text Available ... books ever published in Ophthalmology, "The Wills Eye Manual". We asked Dr. Rapuano for his thoughts on ... have Acanthamoeba keratitis. At that point it’s much more difficult to treat than it would have been if ...

  16. If I Had - A Red Eye from Contact Lens Use

    Science.gov (United States)

    ... books ever published in Ophthalmology, "The Wills Eye Manual". We asked Dr. Rapuano for his thoughts on ... have Acanthamoeba keratitis. At that point it’s much more difficult to treat than it would have been if ...

  17. Saccadic Eye Movement Speed and Motor Response Execution

    Science.gov (United States)

    Williams, Harriet G.; Helfrich, Janet

    1977-01-01

    Evidence was found to indicate that training to improve the speed of saccadic eye movement (movement from one fixation point to another) also resulted in observable changes in batting performance among a sample group of high school girls. (MJB)

  18. MEMS scanner mirror based system for retina scanning and in eye projection

    Science.gov (United States)

    Woittennek, Franziska; Knobbe, Jens; Pügner, Tino; Dallmann, Hans-Georg; Schelinski, Uwe; Grüger, Heinrich

    2015-02-01

    Many applications could benefit from miniaturized systems to scan blood vessels behind the retina in the human eye, so called "retina scanning". This reaches from access control to sophisticated security applications and medical devices. High volume systems for consumer applications require low cost and a user friendly operation. For example this includes no need for removal of glasses and self-adjustment, in turn guidance of focus and point of attraction by simultaneous projection for the user. A new system has been designed based on the well-known resonantly driven 2-d scanner mirror of Fraunhofer IPMS. A combined NIR and VIS laser system illuminates the eye through an eye piece designed for an operating distance allowing the use of glasses and granting sufficient field of view. This usability feature was considered to be more important than highest miniaturization. The modulated VIS laser facilitates the projection of an image directly onto the retina. The backscattered light from the continuous NIR laser contains the information of the blood vessels and is detected by a highly sensitive photo diode. A demonstrational setup has been realized including readout and driving electronics. The laser power was adjusted to an eye-secure level. Additional security features were integrated. Test measurements revealed promising results. In a first demonstration application the detection of biometric pattern of the blood vessels was evaluated for issues authentication in.

  19. Aging and Your Eyes

    Science.gov (United States)

    ... they can be signs of more serious issues. Presbyopia (prez-bee-OH-pee-uh) is a slow ... this problem as you get older. People with presbyopia often have headaches or strained, tired eyes. Reading ...

  20. LASIK eye surgery

    Science.gov (United States)

    ... blurry. This blurriness is referred to as a "refractive error." It is caused by a difference between the ... realistic expectations from the surgery. For people with presbyopia , LASIK cannot correct vision so that one eye ...

  1. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... keep your eyes healthy. "No Rub" a No Go To prevent infection, use the "rub and rinse" ... to fully stabilize and any side effects to go away. LASIK risks and side effects LASIK, like ...

  2. Eye-poking.

    Science.gov (United States)

    Jan, J E; Good, W V; Freeman, R D; Espezel, H

    1994-04-01

    Eye-poking, -rubbing and -pressing are often incorrectly grouped together because of the assumption that they represent variations of the same self-stimulating behaviour. This prospective study of 21 children shows that eye-poking is a distinct, chronic, stereotyped, self-injurious act seen mainly among severely mentally disabled individuals, who may or may not be visually impaired. Eye-poking, which leads to intense, self-induced pain, is a harmful behaviour because it can result in permanent visual loss and even in total blindness. The cause is unclear, although it is probably multifactorial. The treatment is exceedingly difficult. Further studies are needed to develop specific management techniques to prevent eye-poking, which adds to the physical and emotional burden on the caregivers. PMID:8157154

  3. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Search GetEyeSmart.org Diseases & Conditions A to Z ... film. Its main purpose is to smooth the tear surface and reduce evaporation of tears. The middle watery layer makes up most of what we ...

  4. Eye Cosmetic Safety

    Science.gov (United States)

    ... is considered misbranded and is illegal in interstate commerce. Very small packages in tightly compartmented display racks ... Aslam M, Shah AH. Kohl (surma): A toxic traditional eye cosmetic study in Saudi Arabia. Public Health. ...

  5. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... Topics > EyeSmart Tips Protect Your Sight Every Day Wear a hat and sunglasses year round to prevent ... or enhancement) or that you might need to wear glasses for certain activities, such as reading or ...

  6. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... bacteria can cause infection. Use a bag of ice or frozen vegetables instead. High Tech for Low ... 40? A baseline eye exam is recommended at age 40, when the signs of disease and changes ...

  7. Get Your Eyes Tested

    Science.gov (United States)

    ... it hard to see fine details Presbyopia (“prez-bee-OH-bee-uh”) – problems seeing things up close Read more ... Today: Small Steps Protect your eyes from the sun by wearing sunglasses and a hat. Find out ...

  8. What Is Dry Eye?

    Medline Plus

    Full Text Available ... all answered questions > Related Resources Related Topics The link between seasonal allergens and dry eye Four Ways ... by US and international copyright law. You may link from your website to any pages on this ...

  9. 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.

  10. Preventing Eye Injuries

    Science.gov (United States)

    ... at the time of injury (including glasses or contact lenses ), only 5.3 percent were wearing safety or sports glasses . Ophthalmology and Eye Injuries Nearly a dozen ophthalmology organizations are working together ...

  11. Eye Drop Tips

    Science.gov (United States)

    ... next drop in. This will keep the first drop from being washed out by the second before it has had time to work. Store eye drops and all medicines out of the reach of children. Steps For Putting ...

  12. LASIK - Laser Eye Surgery

    Medline Plus

    Full Text Available ... injury. Never lean over the battery and always wear safety goggles. Eye Protection Works Wearing the proper ... or enhancement) or that you might need to wear glasses for certain activities, such as reading or ...

  13. Prescription of eye drops

    OpenAIRE

    O Sullivan, E.; Malhotra, R.; Migdal, C.

    2001-01-01

    The aim of this study was to assess whether patients have their ocular drops correctly prescribed during non-ophthalmic admissions to hospital. A retrospective review of notes of patients who were admitted to hospital for general medical or surgical care, while on regular eye drops at the time of admission was performed. Twenty two patients were on regular ocular medication when admitted. Only seven out of 22 patients had their eye drops correctly prescribed. Furthermore, six patients had be...

  14. Traffic engineering eye diagram

    OpenAIRE

    Kowalik, Karol; Collier, Martin

    2005-01-01

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

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

    Science.gov (United States)

    Aryal, Prakash

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

  16. 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

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

    Directory of Open Access Journals (Sweden)

    Saso Koceski

    2012-10-01

    Full Text Available In this work a pointing interface based on human gestures using a mobile phone accelerometer for interaction with robots is proposed. Through this interface the user can sketch stroke gestures on a computer screen using the cell phone accelerometer to make a selection and instruct a robot to perform a task. Selection, cancelation and movement, as well as some additional commands such as stop, pause and resume are supported. All the projected gestures are processed using known image analysis algorithms providing instantaneous position and path information. The proposed interface is experimentally evaluated and the results show that it is efficient, natural, robust and easy to use. It also provides asynchronous robot control with minimum operator effort and engagement.

  18. Using Eye Tracking for Interaction

    OpenAIRE

    Olsen, Anneli; Schmidt, Albrecht; Marshall, Paul; Sundstedt, Veronica

    2011-01-01

    The development of cheaper eye trackers and open source software for eye tracking and gaze interaction brings the possibility to integrate eye tracking into everyday use devices as well as highly specialized equipment. Apart from providing means for analyzing eye movements, eye tracking also offers the possibility of a natural user interaction modality. Gaze control interfaces are already used within assistive applications for disabled users. However, this novel user i...

  19. Giant sensitivity of long period gratings in transition mode near the dispersion turning point: an integrated design approach.

    Science.gov (United States)

    Pilla, Pierluigi; Trono, Cosimo; Baldini, Francesco; Chiavaioli, Francesco; Giordano, Michele; Cusano, Andrea

    2012-10-01

    We report an original design approach based on the modal dispersion curves for the development of long period gratings in transition mode near the dispersion turning point exhibiting ultrahigh refractive index sensitivity. The theoretical model predicting a giant sensitivity of 9900 nm per refractive index unit in a watery environment was experimentally validated with a result of approximately 9100 nm per refractive index unit around an ambient index of 1.3469. This result places thin film coated LPGs as an alternative to other fiber-based technologies for high-performance chemical and biological sensing applications. PMID:23027309

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

    International Nuclear Information System (INIS)

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

  1. A 99 Dollar Head-Mounted Eye Tracker

    OpenAIRE

    Marko, Youri; Mazzei, Andrea; Kaplan, Frédéric; Dillenbourg, Pierre

    2011-01-01

    Head-mounted eye-trackers are powerful research tools to study attention processes in various contexts. Most existing commercial solutions are still very expensive, limiting the current use of this technology. We present a hardware design to build, at low cost, a camera-based head-mounted eye tracker using two cameras and one infrared LED. A Playstation Eye camera (PEye) is fixed on an eyeglasses frame and positioned under one eye to track its movements. The filter of the PEye is replaced by ...

  2. Comparison of eye imaging pattern recognition using neural network

    Science.gov (United States)

    Bukhari, W. M.; Syed A., M.; Nasir, M. N. M.; Sulaima, M. F.; Yahaya, M. S.

    2015-05-01

    The beauty of eye recognition system that it is used in automatic identifying and verifies a human weather from digital images or video source. There are various behaviors of the eye such as the color of the iris, size of pupil and shape of the eye. This study represents the analysis, design and implementation of a system for recognition of eye imaging. All the eye images that had been captured from the webcam in RGB format must through several techniques before it can be input for the pattern and recognition processes. The result shows that the final value of weight and bias after complete training 6 eye images for one subject is memorized by the neural network system and be the reference value of the weight and bias for the testing part. The target classifies to 5 different types for 5 subjects. The eye images can recognize the subject based on the target that had been set earlier during the training process. When the values between new eye image and the eye image in the database are almost equal, it is considered the eye image is matched.

  3. Constructing a Computer Model of the Human Eye Based on Tissue Slice Images

    OpenAIRE

    Chunbo Bao; Ying Ju; Boliang Wang; Peishan Dai

    2010-01-01

    Computer simulation of the biomechanical and biological heat transfer in ophthalmology greatly relies on having a reliable computer model of the human eye. This paper proposes a novel method on the construction of a geometric model of the human eye based on tissue slice images. Slice images were obtained from an in vitro Chinese human eye through an embryo specimen processing methods. A level set algorithm was used to extract contour points of eye tissues while a principle component analysi...

  4. Effect of eye rotation on visual-field map onto superior colliculus and visual cortex.

    Science.gov (United States)

    Gordon, B; Moran, J; Presson, J

    1983-09-01

    We used multiunit recording to assess the effect of rotating one eye approximately 90 degrees at about the time of normal eye opening. Rotation of the eye did not alter the topography of the retinal maps onto visual cortex or superior colliculus. The intorted eye drove cells at most recording points in the contralateral visual cortex and superior colliculus. In its ipsilateral colliculus the intorted eye drove cells at about 10% of the recording points; that is, the temporal retina of this eye was quite ineffective in driving collicular cells. In its ipsilateral cortex the intorted eye drove cells at about 30% of the recording sites. The unoperated eye drove cells at all locations in both colliculus and cortex on both sides of the brain. The effects of extorsion were studied only in the superior colliculus. Extorsion and intorsion produced similar results except that extorsion produced a less severe deficit in the ability of the temporal retina to drive cells in its ipsilateral colliculus. Cutting all the extraocular muscles without eye rotation was studied only in the colliculus and produced results similar to those produced by intorsion and extorsion. However, the temporal retina of the operated eye was more effective after muscle cut alone than after intorsion or extorsion. Forcing the animal to use the rotated right eye alone on alternate days during the first 3 mo of life did not decrease the deficits. Almost all recording sites in the right colliculus were driven only by the unoperated left eye. If the left eye was sutured when the right eye was rotated, only the right eye drove cells in the left colliculus, but the two eyes were about equally effective in the right colliculus; however, rather few sites in the right colliculus were binocularly driven. We conclude that both extraocular muscle section and eye rotation reduce the effectiveness of the uncrossed input from the operated eye to the superior colliculus and visual cortex. The effects on the superior colliculus are, however, greater. PMID:6619910

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

    Energy Technology Data Exchange (ETDEWEB)

    D. M. McEligot; G. E. McCreery

    2004-09-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  7. 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)

    Eperjesi Frank

    2003-10-01

    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.

  8. 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)

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

    2014-12-01

    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

  9. Triangulating eye movement data of animated displays

    OpenAIRE

    Maggi, Sara; Fabrikant, Sara I

    2014-01-01

    We present a cross-validation approach to assess animations of movement data. Specifically, we investigate if and how display design, data complexity and user background and training might influence participants’ decision-making with animated designs. Our triangulation approach is based on eye-tracking records, galvanic skin conductance responses, and electroencephalography data. We raise data analysis issues and data synchronization challenges for discussion at the workshop relating to dat...

  10. Eye Disease and Development

    DEFF Research Database (Denmark)

    Andersen, Thomas Barnebeck; Dalgaard, Carl-Johan Lars

    2011-01-01

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

  11. Eye of the Beholder

    Science.gov (United States)

    Rogers, Michael

    2010-01-01

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

  12. Eye-Tracking.

    Science.gov (United States)

    Tanenhaus, Michael K.; Spivey-Knowlton, Michael J.

    1996-01-01

    Reviews the eye-movement paradigm and refers to recent experiments applying the paradigm to issues of spoken word recognition (e.g., lexical competitor effects), syntactic processing, reference resolution, focus, as well as issues in cross-modality integration that are central to evaluating the modularity hypothesis. (Seven references) (Author/CK)

  13. The accuracy of the Edinburgh Red Eye Diagnostic Algorithm.

    Science.gov (United States)

    Timlin, H; Butler, L; Wright, M

    2015-05-01

    PurposeTo assess the diagnostic accuracy of the Edinburgh Red Eye Algorithm.MethodsThis was a prospective study. A questionnaire was designed and made available to clinicians referring patients to the acute ophthalmology service within Edinburgh. The questionnaire involved them using the algorithm to reach a diagnosis in patients presenting with red eye(s). Patients were then referred to the emergency eye clinic and the questionnaire faxed to the clinic or sent with the patients. Patients were then examined by an experienced ophthalmologist (not blinded) to reach a 'gold standard' diagnosis. The concordance between the 'algorithm assisted' diagnosis and the 'gold standard' was then assessed.ResultsAll patients presenting with red eye(s) were eligible for inclusion. Forty-one questionnaires were completed, two were excluded. The algorithm assisted diagnosis was correct 72% (28/39) of the time. It correctly diagnosed: acute angle closure glaucoma in 100% of cases (4/4); iritis in 82% (9/11); stromal keratitis in 63% (5/8); epithelial keratitis in 70% (7/10); and infective conjunctivitis in 50% (3/6).DiscussionThe diagnostic accuracy of The Edinburgh Red Eye Diagnostic Algorithm is 72, rising to 76% when only the most serious red eye(s) causes are included. The diagnostic accuracy of nonophthalmologists when assessing patients presenting with red eye(s) is greater when the algorithm is used. We hope that the use of this algorithm will prevent delayed presentations of certain serious eye conditions and reduce the morbidity from delayed treatment. PMID:25697458

  14. Eye Bank Association of America

    Science.gov (United States)

    ... to content Skip to Navigation Find an Eye Bank Near You MEMBER LOGIN The vision of the ... is the nationally-recognized accrediting body for eye banks. Since 1961, EBAA member banks have restored sight ...

  15. If I Had - Dry Eyes

    Medline Plus

    Full Text Available ... Cognitive Decline Seen in Older Adults with Severe COPD VIDEO: If I Had - Dry Eyes - Dr. Penny ... if we treat that we can help the patient. Who is at risk of developing dry eye? ...

  16. If I Had - Dry Eyes

    Medline Plus

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

  17. Roundworm Parasite Targets Canine Eyes

    Science.gov (United States)

    ... nih.gov/medlineplus/news/fullstory_152059.html Roundworm Parasite Targets Canine Eyes Report says small number of ... United States have been infected by a roundworm parasite that targets the eye, according to a new ...

  18. If I Had - Dry Eyes

    Medline Plus

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

  19. Investigation of the SQUBIC phase mask design for depth-invariant widefield microscopy point-spread function engineering

    Science.gov (United States)

    Doblas, Ana; King, Sharon V.; Patwary, Nurmohammed; Saavedra, Genaro; Martínez-Corral, Manuel; Preza, Chrysanthe

    2014-03-01

    Point-spread function engineering (PSF), achieved by placing a phase mask at the pupil plane of the imaging lens to encode the wavefront emerging from an imaging system, can be employed to reduce the impact of spherical aberration (SA) in 3D microscopy. In a previous study, the effect of SA on a confocal scanning microscope using a squared cubic phase mask (SQUBIC) was investigated using computer simulations. Here the effect of the SQUBIC design parameter on the insensitivity of the engineered PSF to SA is investigated using a metric based on the second-order moment of the axial variability of the PSF. We show that it is possible to find the optimum SQUBIC for the insensitization to SA.

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

    Science.gov (United States)

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

    2011-01-01

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

  1. 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’ ...

  2. 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 Avoid Indoor Tanning ...

  3. 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 Protect Your Sight ...

  4. Pink Eye: What To Do

    Centers for Disease Control (CDC) Podcasts

    2010-10-12

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

  5. Eye movements when viewing advertisements

    OpenAIRE

    EmilyHiggins

    2014-01-01

    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 ...

  6. Antioxidants and Age-Related Eye Disease

    Science.gov (United States)

    ... Your Vision > Nutrition > Antioxidants & Age-Related Eye Disease Antioxidants & Age-Related Eye Disease PDF Version (389 KB) ... of protecting the eyes from these diseases. Research - Antioxidants and AMD The Age-Related Eye Disease Study ...

  7. Spectacle-related eye injuries, spectacle-impact performance and eye protection.

    Science.gov (United States)

    Hoskin, Annette K; Philip, Swetha; Dain, Stephen J; Mackey, David A

    2015-05-01

    The aim was to review the prevalence of spectacle-related ocular trauma and the performance of currently available spectacle materials and to identify the risk factors associated with spectacle-related ocular trauma. A literature review was conducted using Medline, Embase and Google with the keywords 'eyeglasses' OR 'spectacles' AND 'ocular injury' / 'eye injury'/ 'eye trauma' / 'ocular trauma'. Articles published prior to 1975 were excluded from this review because of advances in spectacle lens technology and Food and Drug Administration legislative changes requiring impact resistance of all prescription spectacle lenses in the United States. Six hundred and ninety-five individual ocular traumas, for which spectacles contributed to or were the main cause of injury, were identified in the literature. Eye injuries occurred when spectacles were worn in sports, in which medium- to high-impact energies were exerted from balls, racquets or bats and/or as a result of a collision with another player. Frame, lens design and product material choice were found to be associated with ocular injury, with polycarbonate lenses cited as the material of choice in the literature. International, regional and national standards for spectacle lenses had a wide range of impact requirements for prescription spectacle lenses, sports eye protection and occupational eye protection. Spectacle-related injury represents a small but preventable cause of ocular injury. With the increasing numbers of spectacle wearers and calls to spend more time outdoors to reduce myopia, spectacle wearers need to be made aware of the potential risks associated with wearing spectacles during medium- to high-risk activities. At particular risk are those prone to falls, the functionally one-eyed, those who have corneal thinning or have had previous eye surgery or injury. With increased understanding of specific risk factors, performance guidelines can be developed for prescription spectacle eye-protection requirements. PMID:25963111

  8. Shielding design of an underground experimental area at point 5 of the CERN Super Proton Synchrotron (SPS)

    International Nuclear Information System (INIS)

    Increasing projected values of the circulating beam intensity in the Super Proton Synchrotron (SPS) and decreasing limits to radiation exposure, taken with the increasing non-acceptance of unjustified and un-optimised radiation exposures, have led to the need to re-assess the shielding between the ECX and ECA5 underground experimental areas of the SPS. Twenty years ago, these experimental areas at SPS-Point 5 housed the UA1 experiment, where Carlo Rubbia and his team verified the existence of W and Z bosons. The study reported here describes such a re-assessment based on simulations using the multi-purpose FLUKA radiation transport code. This study concludes that while the main shield which is made of concrete blocks and is 4.8 m thick satisfactorily meets the current design limits even at the highest intensities presently planned for the SPS, dose rates calculated for liaison areas on both sides of the main shield significantly exceed the design limits. Possible ways of improving the shielding situation are discussed. (authors)

  9. Shielding design of an underground experimental area at point 5 of the CERN Super Proton Synchrotron (SPS).

    Science.gov (United States)

    Mueller, Mario J; Stevenson, Graham R

    2005-01-01

    Increasing projected values of the circulating beam intensity in the Super Proton Synchrotron (SPS) and decreasing limits to radiation exposure, taken with the increasing non-acceptance of unjustified and unoptimised radiation exposures, have led to the need to re-assess the shielding between the ECX and ECA5 underground experimental areas of the SPS. Twenty years ago, these experimental areas at SPS-Point 5 housed the UA1 experiment, where Carlo Rubbia and his team verified the existence of W and Z bosons. The study reported here describes such a re-assessment based on simulations using the multi-purpose FLUKA radiation transport code. This study concludes that while the main shield which is made of concrete blocks and is 4.8 m thick satisfactorily meets the current design limits even at the highest intensities presently planned for the SPS, dose rates calculated for liaison areas on both sides of the main shield significantly exceed the design limits. Possible ways of improving the shielding situation are discussed. PMID:16381709

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

    DEFF Research Database (Denmark)

    Andersen, Jeppe D.; Johansen, Peter

    2013-01-01

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

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

    Science.gov (United States)

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

    2013-11-01

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

  12. 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

  13. An Eye Detection Algorithm Using Pixel to Edge Information

    OpenAIRE

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

    2010-01-01

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

  14. Anticipating the three-dimensional consequences of eye movements

    OpenAIRE

    Wexler, Mark

    2005-01-01

    Rapid eye movements called saccades give rise to sudden, enormous changes in optic information arriving at the eye; how the world nonetheless appears stable is known as the problem of spatial constancy. One consequence of saccades is that the directions of all visible points shift uniformly; directional or 2D constancy, the fact that we do not perceive this change, has received extensive study for over a century. The problems raised by 3D consequences of saccades, on the other hand, have been...

  15. An Appearance based Method for Eye Gaze Tracking

    OpenAIRE

    Sheela, S. V.; Vijaya, P. A.

    2011-01-01

    Problem statement: Gaze estimation systems compute the direction of eye gaze based on observed eye movements. The need for gaze-contingent applications is the basis of the current research work. The gaze pointing systems is a substitute for the existing input devices. Approach: The gaze tracking methods are either feature based or appearance based. In this study, an appearance based approach for gaze tracking is proposed based on Run Length Coding (RLC). The experiment was conducted consideri...

  16. Hemispheric asymmetries in eye-hand coordination.

    Science.gov (United States)

    Lavrysen, Ann; Heremans, Elke; Peeters, Ron; Wenderoth, Nici; Helsen, Werner F; Feys, Peter; Swinnen, Stephan P

    2008-02-15

    Manual asymmetries in limb kinematics and eye-hand coordination have usually been attributed to differences in online processing capabilities between the left and the right cerebral hemisphere. In the present fMRI experiment, we examined in right handers the brain areas involved in eye-hand coordination with either the left or the right hand. Although temporal and spatial accuracy was equal for left- and right-hand movements, manual asymmetries were found in behavioral and neurophysiologic data, suggesting an asymmetric mode of control for left vs. right eye-hand coordination. For left eye-hand coordination, peak velocity and saccade completion occurred earlier than for the contralateral movements, suggesting that there was more time needed for homing-in on the target. When using the right hand, there was more activation in occipital areas. This might indicate a more intense visual processing or visualization of the target locations. When using the left hand, there was more activation in sensorimotor areas, frontal areas and cerebellum. This might point toward more processing effort. Left-hand movements may be considered as more difficult than right-hand movements by right-handed participants. Alternatively and more likely, these findings might reflect a difference in attention or resources attributed to different aspects of the tasks because of the different functional specializations of both hand/hemisphere systems. PMID:18053745

  17. Obesity and Eye Diseases

    OpenAIRE

    Cheung, Ning; Wong, Tien Y

    2007-01-01

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

  18. Through Einstein's Eyes

    Science.gov (United States)

    Savage, Craig M.

    Through Einstein's Eyes is the online version of a multimedia project based around how things look at relativistic speeds. It is aimed at high school to early university level physics students. There are two sections. One is fun and spectacular, with a relativistic rollercoaster ride and a tour of the solar system. The other explores the physics of special relativity. CD and DVD versions of the material are available, and are helpful because of the large size of some of the video files.

  19. 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.

  20. Eye in pregnancy

    OpenAIRE

    Pandey, Achyut N.

    2014-01-01

    Hormonal, metabolic, hemodynamic, vascular and immunological changes that occur during pregnancy can affect the function of the eye. These changes are commonly transient, but in some cases they may be permanent and have consequences even after childbirth. The ocular effects of pregnancy may be physiological or pathological and can be associated with the development of new ocular pathology or may be modifications of pre-existing conditions. The most common physiological changes are alterations...

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

    Science.gov (United States)

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

    2014-01-01

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

  2. Eye movements compensation in excimer laser keratectomy

    Science.gov (United States)

    Molebny, Vasyl V.; Semenov, Alexandr P.; Kornilovsky, Igor

    1994-02-01

    Rapid development of ArF excimer laser keratectomy discovered new problems connected with incessant eye movements during the operation. The authors report the results of these movements study using TV camera, assisting the operation of myopia correction, and special programs developed to animate the IBM PC compatible PCVISIONplus frame grabber. Three kinds of movements are described: one-point sight fixation, having not and having a preferable direction of movements, and two or even more points of sight fixation. The only radical way to compensate for all these types of movements is automatic laser beam tracking during the operation.

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

    Science.gov (United States)

    Harriet, E Hollander

    2009-10-01

    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

  4. 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)

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

    Science.gov (United States)

    Rasouli, H.; Fatehi, A.

    2014-12-01

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

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

    Science.gov (United States)

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

    2015-02-01

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

  7. The fly's eye camera system

    Science.gov (United States)

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

    2014-12-01

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

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

    Science.gov (United States)

    Annie Prud?homme Genereux

    2011-01-01

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

  9. Eye gaze tracking using correlation filters

    Science.gov (United States)

    Karakaya, Mahmut; Bolme, David; Boehnen, Chris

    2014-03-01

    In this paper, we studied a method for eye gaze tracking that provide gaze estimation from a standard webcam with a zoom lens and reduce the setup and calibration requirements for new users. Specifically, we have developed a gaze estimation method based on the relative locations of points on the top of the eyelid and eye corners. Gaze estimation method in this paper is based on the distances between top point of the eyelid and eye corner detected by the correlation filters. Advanced correlation filters were found to provide facial landmark detections that are accurate enough to determine the subjects gaze direction up to angle of approximately 4-5 degrees although calibration errors often produce a larger overall shift in the estimates. This is approximately a circle of diameter 2 inches for a screen that is arm's length from the subject. At this accuracy it is possible to figure out what regions of text or images the subject is looking but it falls short of being able to determine which word the subject has looked at.

  10. Eye Gaze Tracking using Correlation Filters

    Energy Technology Data Exchange (ETDEWEB)

    Karakaya, Mahmut [ORNL; Boehnen, Chris Bensing [ORNL; Bolme, David S [ORNL; Mahallesi, Mevlana [Meliksah University, Turkey; Kayseri, Talas [Meliksah University, Turkey

    2014-01-01

    In this paper, we studied a method for eye gaze tracking that provide gaze estimation from a standard webcam with a zoom lens and reduce the setup and calibration requirements for new users. Specifically, we have developed a gaze estimation method based on the relative locations of points on the top of the eyelid and eye corners. Gaze estimation method in this paper is based on the distances between top point of the eyelid and eye corner detected by the correlation filters. Advanced correlation filters were found to provide facial landmark detections that are accurate enough to determine the subjects gaze direction up to angle of approximately 4-5 degrees although calibration errors often produce a larger overall shift in the estimates. This is approximately a circle of diameter 2 inches for a screen that is arm s length from the subject. At this accuracy it is possible to figure out what regions of text or images the subject is looking but it falls short of being able to determine which word the subject has looked at.

  11. Rapid torque-bounded line-of-sight pointing of SCOLE with a designer's choice of initial alignment

    Science.gov (United States)

    Lin, Jiguan Gene

    1984-01-01

    Researchers simplified the analytical expression of the line of sight (LOS) error, discovered and proved the independence of Euler angle Psi, calculated attitude angles corresponding to 0 degrees and 20 degrees LOS errors, determined choices of initial alignment, tailored the slew maneuvers for LOS pointing, simulated numerically the LOS pointing slew of the Spacecraft Control Laboratory Experiment (SCOLE), and evaluated the pointing performance.

  12. New eye phantom for ophthalmic surgery

    Science.gov (United States)

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

    2014-06-01

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

  13. The Fly's Eye: Status and future prospects

    International Nuclear Information System (INIS)

    The authors describe a high energy physics observatory, the Fly's Eye, designed to measure extensive air showers (EAS) in the energy range 10/sup 17/-10/sup 21/eV via atmospheric fluorescence. Preliminary results are presented for the following measurements: the high energy cosmic ray spectrum, at 10/sup 17/-10/sup 19/eV, the total proton cross section ?/sub pp/, and limits on the extra-galactic neutrino flux at 10/sup 20/eV

  14. Operational procedure for computer program for design point characteristics of a gas generator or a turbojet lift engine for V/STOL applications

    Science.gov (United States)

    Krebs, R. P.

    1972-01-01

    The computer program described calculates the design-point characteristics of a gas generator or a turbojet lift engine for V/STOL applications. The program computes the dimensions and mass, as well as the thermodynamic performance of the model engine and its components. The program was written in FORTRAN 4 language. Provision has been made so that the program accepts input values in either SI Units or U.S. Customary Units. Each engine design-point calculation requires less than 0.5 second of 7094 computer time.

  15. Equipment for eye care

    OpenAIRE

    Mason I; Mathenge W.

    2010-01-01

    In many low- and middle-income countries, it is often the people who are poor or with a disability - or both - who find it most challenging to access and pay for health care. When people do come to us for eye care, it is therefore vital that we provide quality services efficiently and effectively.To achieve this goal, we must ensure that our equipment is well maintained and that we have enough spare parts and consumables for it to function with minimum interruptions. To cope with the sometime...

  16. 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.

  17. The pregnant woman's eye.

    Science.gov (United States)

    Sunness, J S

    1988-01-01

    The effects of pregnancy on the eye fall into three categories. Nonpathological physiologic changes in pressures, corneal sensitivity and thickness, and visual function can occur. Pathologic conditions reported to develop during pregnancy include central serous chorioretinopathy, hypertensive and vascular disorders, and uveal melanoma. Pregnancy also can affect pre-existing ocular conditions, such as diabetic retinopathy, tumors, and a variety of immunological disorders and can have beneficial effects on such pre-existing conditions as glaucoma. This review covers ocular disorders in these three categories, and summarizes the systemic changes of pregnancy and the effects of ocular medications on the fetus. PMID:3279558

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

    Directory of Open Access Journals (Sweden)

    Gneo Massimo

    2012-11-01

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

  19. Hospital epidemiology of dry eye

    OpenAIRE

    Khurana A; Choudhary R; Ahluwalia B; Gupta S

    1991-01-01

    One hundred consecutive cases of dry eye were studied to comment upon its epidemiological aspects. The incidence of dry eye amongst ophthalmic outpatients was 0.46% with a male:female ratio of 1:1.22. Fifty seven percent of the patients were above 50 years of age. The incidence was higher amongst outdoor workers and people from rural areas with poor socioeconomic status. The influence of hot and dry climate and nutritional status on dry eye incidence is discussed.

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

    Medline Plus

    Full Text Available ... Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During Pregnancy Computer Usage & Eye Strain Maintaining ... has on your eyes. Is 3-D technology healthy for your or your children's eyes? Although there ...

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

    Medline Plus

    Full Text Available ... Bad for Your Eyes? Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During Pregnancy Computer ... Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Avoid Indoor Tanning Studies show UV ...

  2. 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 ...

  3. Drawing from Memory: Hand-Eye Coordination at Multiple Scales

    OpenAIRE

    Huette, Stephanie; Kello, Christopher T.; Rhodes, Theo; Spivey, Michael J.

    2013-01-01

    Eyes move to gather visual information for the purpose of guiding behavior. This guidance takes the form of perceptual-motor interactions on short timescales for behaviors like locomotion and hand-eye coordination. More complex behaviors require perceptual-motor interactions on longer timescales mediated by memory, such as navigation, or designing and building artifacts. In the present study, the task of sketching images of natural scenes from memory was used to examine and compare perceptual...

  4. Characteristics of eye care practices with managed care contracts

    OpenAIRE

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

    2002-01-01

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

  5. Ultraviolet radiation: the eye

    International Nuclear Information System (INIS)

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

  6. Eye in pregnancy

    Directory of Open Access Journals (Sweden)

    Achyut N. Pandey

    2014-02-01

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

  7. Eye in the Sky

    Science.gov (United States)

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

  8. Practical evaluation of an interior point three-D filter line search method using engineering design problems

    OpenAIRE

    M. Fernanda P. Costa; Fernandes, Edite Manuela da G. P.

    2009-01-01

    We present a primal-dual interior point method for nonlinear optimization that relies on a line search filter strategy to allow convergence from poor starting points. The filter technique has already been adapted to interior point methods in different ways. Our filter relies on three components. Each entry in the filter includes the feasibility measure, the centrality measure and the barrier objective function value as the optimality measure. Numerical experiments carried...

  9. Minority Eye Health: Know Your Risks

    Science.gov (United States)

    ... Usage & Eye Strain Maintaining Your Sight with Diabetes Sports and Eye Protection Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Avoid Indoor Tanning Studies show UV exposure from tanning beds can cause eye damage and skin cancer. Not the look you're ...

  10. Visible-spectrum remote eye tracker for gaze communication

    Science.gov (United States)

    Imabuchi, Takashi; Prima, Oky Dicky A.; Kikuchi, Hikaru; Horie, Yusuke; Ito, Hisayoshi

    2015-03-01

    Many approaches have been proposed to create an eye tracker based on visible-spectrum. These efforts provide a possibility to create inexpensive eye tracker capable to operate outdoor. Although the resulted tracking accuracy is acceptable for a visible-spectrum head-mounted eye tracker, there are many limitations of these approaches to create a remote eye tracker. In this study, we propose a high-accuracy remote eye tracker that uses visible-spectrum imaging and several gaze communication interfaces suited to the tracker. The gaze communication interfaces are designed to assist people with motor disability. Our results show that the proposed eye tracker achieved an average accuracy of 0.77° and a frame rate of 28 fps with a personal computer. With a tablet device, the proposed eye tracker achieved an average accuracy of 0.82° and a frame rate of 25 fps. The proposed gaze communication interfaces enable users to type a complete sentence containing eleven Japanese characters in about a minute.

  11. Gold-nanoparticle-based colorimetric discrimination of cancer-related point mutations with picomolar sensitivity.

    Science.gov (United States)

    Valentini, Paola; Fiammengo, Roberto; Sabella, Stefania; Gariboldi, Manuela; Maiorano, Gabriele; Cingolani, Roberto; Pompa, Pier Paolo

    2013-06-25

    Point mutations in the Kirsten rat sarcoma viral oncogene homologue (KRAS) gene are being increasingly recognized as important diagnostic and prognostic markers in cancer. In this work, we describe a rapid and low-cost method for the naked-eye detection of cancer-related point mutations in KRAS based on gold nanoparticles. This simple colorimetric assay is sensitive (limit of detection in the low picomolar range), instrument-free, and employs nonstringent room temperature conditions due to a combination of DNA-conjugated gold nanoparticles, a probe design which exploits cooperative hybridization for increased binding affinity, and signal enhancement on the surface of magnetic beads. Additionally, the scheme is suitable for point-of-care applications, as it combines naked-eye detection, small sample volumes, and isothermal (PCR-free) amplification. PMID:23697628

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-07-15

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

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2013-03-01

    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.

  15. Eye trauma in the workplace.

    Science.gov (United States)

    Boyd-Monk, H

    1991-01-01

    Immediate eye irrigation in the case of chemical burns can substantially decrease the possibility of permanent vision damage. A baseline visual acuity should be on record for medical and legal purposes. Identifying an eye injury and referring the person for appropriate treatment can save vision. PMID:2061932

  16. What is Diabetic Eye Disease?

    Medline Plus

    Full Text Available ... where elevated pressure inside the eye damages the optic nerve and if left untreated, impairs vision. That's the bad news. The good news is that each of these diabetic eye diseases can be treated and treated with success.

  17. Eye changes in psoriatic arthropathy

    Directory of Open Access Journals (Sweden)

    Chaudhari SP

    1990-01-01

    Full Text Available Forty patients of psoriatic arthitis were examined for eye changes. Other than blepharitis seen in 2 patients and seitile cataract in 3 patients no eye changes could be elicited. Out of the, 18 patients HLA-B 27 was in 3 patients whereas Al and B 17 was in 6 and 9 patients respectively.

  18. Eyelashes divert airflow to protect the eye.

    Science.gov (United States)

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

    2015-04-01

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

  19. Gray Eye Traffic Surveillance

    Directory of Open Access Journals (Sweden)

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

    2011-06-01

    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.

  20. Eye and pregnancy.

    Science.gov (United States)

    Gotovac, Marta; Kastelan, Snjezana; Lukenda, Adrian

    2013-04-01

    Hormonal, metabolic, hemodynamic, vascular and immunological changes that occur during pregnancy can affect the function of the eye. These changes are commonly transient, but in some cases they may be permanent and have consequences even after childbirth. The ocular effects of pregnancy may be physiological or pathological and can be associated with the development of new ocular pathology or may be modifications of pre-existing conditions. The most common physiological changes are alterations of corneal sensitivity and thickness, decreased tolerance to contact lenses, decreased intraocular pressure, hemeralopia and refractive errors. Possible posterior segment changes include worsening of diabetic retinopathy, central serous chorioretinopathy, increased risk of peripheral vitreochorioretinal dystrophies and retinal detachment. Thus, it should be kept in mind that the presence of any ocular symptoms in a pregnant woman requires ophthalmologic examination and further management. PMID:23837242

  1. Eye movements in Alzheimer's disease.

    Science.gov (United States)

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

    2015-01-01

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

  2. Anesthesia for Adults Having Eye Surgery

    Science.gov (United States)

    ... 3/2015 Eye Terms & Conditions Most Common Searches Adult Strabismus Amblyopia Cataract Conjunctivitis Corneal Abrasions Dilating Eye Drops Lazy ... Screening Vision Screening Recommendations Loading... Most Common Searches Adult ... Abrasions Dilating Eye Drops Lazy ...

  3. 48 CFR 47.303-16 - F.o.b. designated air carrier's terminal, point of importation.

    Science.gov (United States)

    2010-10-01

    ...2010-10-01 2010-10-01 false F.o.b. designated air carrier's terminal...Transportation in Supply Contracts 47.303-16 F.o.b. designated air carrier's terminal... (a) Explanation of delivery term. F.o.b. designated air carrier's...

  4. 48 CFR 52.247-44 - F.o.b. Designated Air Carrier's Terminal, Point of Importation.

    Science.gov (United States)

    2010-10-01

    ...2010-10-01 2010-10-01 false F.o.b. Designated Air Carrier's Terminal...Provisions and Clauses 52.247-44 F.o.b. Designated Air Carrier's Terminal...solicitations and contracts when the delivery term is f.o.b. designated air carrier's...

  5. Unoperated eyes with persistent fetal vasculature.

    OpenAIRE

    Gulati, Nishi; Eagle, Ralph C; Tasman, William

    2003-01-01

    PURPOSE: To present a follow-up on children with persistent fetal vasculature (PFV) when surgery was not performed. METHODS: From January 1992 through June 2001, 31 infants (31 eyes) with PFV were evaluated to document the number of eyes operated on versus eyes not operated on to determine whether the latter group remained stationary or became worse. RESULTS: Seventeen of the 31 eyes underwent surgery. Of the 14 eyes not undergoing surgery, 7 were judged to be inoperable. The remaining 7 eyes...

  6. Eyes on the LHC

    CERN Multimedia

    Gianotti, Fabiola

    2007-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Eduard Gregorio

    2015-02-01

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

  8. Edge Detection Model Based on Involuntary Eye Movements of the Eye-Retina System

    Directory of Open Access Journals (Sweden)

    András Róka

    2007-03-01

    Full Text Available Traditional edge-detection algorithms in image processing typically convolute afilter operator and the input image, and then map overlapping input image regions tooutput signals. Convolution also serves as a basis in biologically inspired (Sobel, Laplace,Canny algorithms. Recent results in cognitive retinal research have shown that ganglioncell receptive fields cover the mammalian retina in a mosaic arrangement, withinsignificant amounts of overlap in the central fovea. This means that the biologicalrelevance of traditional and widely adapted edge-detection algorithms with convolutionbasedoverlapping operator architectures has been disproved. However, using traditionalfilters with non-overlapping operator architectures leads to considerable losses in contourinformation. This paper introduces a novel, tremor-based retina model and edge-detectionalgorithm that reconciles these differences between the physiology of the retina and theoverlapping architectures used by today's widely adapted algorithms. The algorithm takesinto consideration data convergence, as well as the dynamic properties of the retina, byincorporating a model of involuntary eye tremors and the impulse responses of ganglioncells. Based on the evaluation of the model, two hypotheses are formulated on the highlydebated role of involuntary eye tremors: 1 The role of involuntary eye tremors hasinformation theoretical implications 2 From an information processing point of view, thefunctional role of involuntary eye-movements extends to more than just the maintenance ofaction potentials. Involuntary eye-movements may be responsible for the compensation ofinformation losses caused by a non-overlapping receptive field architecture. In support ofthese hypotheses, the article provides a detailed analysis of the model's biologicalrelevance, along with numerical simulations and a hardware implementation.

  9. Stem cell treatment of degenerative eye disease

    Directory of Open Access Journals (Sweden)

    Ben Mead

    2015-05-01

    Full Text Available Stem cell therapies are being explored extensively as treatments for degenerative eye disease, either for replacing lost neurons, restoring neural circuits or, based on more recent evidence, as paracrine-mediated therapies in which stem cell-derived trophic factors protect compromised endogenous retinal neurons from death and induce the growth of new connections. Retinal progenitor phenotypes induced from embryonic stem cells/induced pluripotent stem cells (ESCs/iPSCs and endogenous retinal stem cells may replace lost photoreceptors and retinal pigment epithelial (RPE cells and restore vision in the diseased eye, whereas treatment of injured retinal ganglion cells (RGCs has so far been reliant on mesenchymal stem cells (MSC. Here, we review the properties of non-retinal-derived adult stem cells, in particular neural stem cells (NSCs, MSC derived from bone marrow (BMSC, adipose tissues (ADSC and dental pulp (DPSC, together with ESC/iPSC and discuss and compare their potential advantages as therapies designed to provide trophic support, repair and replacement of retinal neurons, RPE and glia in degenerative retinal diseases. We conclude that ESCs/iPSCs have the potential to replace lost retinal cells, whereas MSC may be a useful source of paracrine factors that protect RGC and stimulate regeneration of their axons in the optic nerve in degenerate eye disease. NSC may have potential as both a source of replacement cells and also as mediators of paracrine treatment.

  10. Stem cell treatment of degenerative eye disease?

    Science.gov (United States)

    Mead, Ben; Berry, Martin; Logan, Ann; Scott, Robert A.H.; Leadbeater, Wendy; Scheven, Ben A.

    2015-01-01

    Stem cell therapies are being explored extensively as treatments for degenerative eye disease, either for replacing lost neurons, restoring neural circuits or, based on more recent evidence, as paracrine-mediated therapies in which stem cell-derived trophic factors protect compromised endogenous retinal neurons from death and induce the growth of new connections. Retinal progenitor phenotypes induced from embryonic stem cells/induced pluripotent stem cells (ESCs/iPSCs) and endogenous retinal stem cells may replace lost photoreceptors and retinal pigment epithelial (RPE) cells and restore vision in the diseased eye, whereas treatment of injured retinal ganglion cells (RGCs) has so far been reliant on mesenchymal stem cells (MSC). Here, we review the properties of non-retinal-derived adult stem cells, in particular neural stem cells (NSCs), MSC derived from bone marrow (BMSC), adipose tissues (ADSC) and dental pulp (DPSC), together with ESC/iPSC and discuss and compare their potential advantages as therapies designed to provide trophic support, repair and replacement of retinal neurons, RPE and glia in degenerative retinal diseases. We conclude that ESCs/iPSCs have the potential to replace lost retinal cells, whereas MSC may be a useful source of paracrine factors that protect RGC and stimulate regeneration of their axons in the optic nerve in degenerate eye disease. NSC may have potential as both a source of replacement cells and also as mediators of paracrine treatment. PMID:25752437

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

    OpenAIRE

    Khandekar Rajiv; Mohammed A

    2009-01-01

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

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

    Science.gov (United States)

    Siko, Jason; Barbour, Michael

    2013-01-01

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

  13. Review of current methods for estimating areal reduction factors applied to South African design point rainfall and preliminary identification of new methods

    Scientific Electronic Library Online (English)

    J P J, Pietersen; O J, Gericke; J C, Smithers; Y E, Woyessa.

    2015-03-01

    Full Text Available Design point rainfall estimates assume a uniform distribution of rainfall over a catchment, and hence are only representative for a limited area. For larger areas, areal reduction factors (ARFs) are used to convert design point rainfall depths/intensities to an average areal design rainfall depth/in [...] tensity for a catchment-specific critical storm duration and catchment area. This paper presents a review of ARF estimation methods used nationally and internationally, with comparisons of the South African methods in the C5 secondary drainage region using standard input variables. The comparison of different ARF estimation methods confirmed that the empirical methods adopted for general use in South Africa are based on a limited database of observed rainfall data and are used without local correction factors beyond their original developmental regions. This results in the characterisation of the actual rainfall process over a catchment, and translation into questionable design peak discharge estimates. Therefore, the ARFs in South Africa need to be re-investigated in the light of recent extreme flood events, utilising the longer periods of record and denser rain-gauge networks which are now available for analysis. The variation of ARFs with return period and with rainfall producing mechanisms also needs to be investigated. Updated ARFs developed and verified using local rainfall data will improve the accuracy of design hydrology for large catchments in South Africa when event-based rainfall-runoff deterministic methods are used.

  14. 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

  15. 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)

    Krebs, R. P.

    1971-01-01

    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.

  16. The interblink interval in normal and dry eye subjects

    Directory of Open Access Journals (Sweden)

    Johnston PR

    2013-02-01

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

  17. 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

  18. If I Had - Dry Eyes

    Science.gov (United States)

    ... Lower in Migraine Sufferers, Cognitive Decline Seen in Older Adults with Severe COPD VIDEO: If I Had - Dry Eyes - Dr. Penny Asbell, MD, FACS, MBA, Professor of Ophthalmology, Mount Sinai School of Medicine, New York Back to Home Page ...

  19. Eye-based head gestures

    DEFF Research Database (Denmark)

    Mardanbegi, Diako; Witzner Hansen, Dan

    2012-01-01

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

  20. What is Diabetic Eye Disease?

    Medline Plus

    Full Text Available ... diabetes and while most will not lose their vision if they receive treatment, their risk is 25 ... detach, resulting in partial or total loss of vision. Announcer: Diabetic retinopathy is not the only eye ...

  1. If I Had - Dry Eyes

    Medline Plus

    Full Text Available ... News For July 10, 2009 VIDEO: Low-Calorie Diet May Help Maintain Youth, Breast Cancer Risk Lower ... feel for classify dry eye disease and how best to treat it. But typically we start out ...

  2. Eye Movements When Viewing Advertisements

    Directory of Open Access Journals (Sweden)

    EmilyHiggins

    2014-03-01

    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.

  3. Nutrition and the Aging Eye

    Science.gov (United States)

    ... Issue Past Issues Special Section Nutrition and the Aging Eye Past Issues / Winter 2007 Table of Contents ... study showed that an experimental combination of three anti-oxidant vitamins (C, E and beta carotene) and ...

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

    Medline Plus

    Full Text Available ... Torn Retina Diabetic Retinopathy Dry Eye Floaters & Flashes Glaucoma Hyperopia (Farsightedness) Low Vision Myopia (Nearsightedness) Pink Eye ( ... Remedies for Simple Eye Problems Medical Marijuana for Glaucoma Pregnancy Preventing Eye Injuries Smokers Sports Using Eye ...

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

    Medline Plus

    Full Text Available ... Low Vision Myopia (Nearsightedness) Pink Eye (Conjunctivitis) Presbyopia (Aging Eye) Stye Uveitis/Iritis See all Diseases & Conditions > ... Diabetes Diet & Nutrition Eye Injuries Eye Screening Guidelines Home Remedies for Simple Eye Problems Medical Marijuana for ...

  6. 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 ...

  7. 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 ...

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

    Medline Plus

    Full Text Available ... Alerts Are 3-D Movies Bad for Your Eyes? Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes ... permanent loss of your eyelashes. Hold the Rib Eye Don’t put raw meat on a black ...

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

    Directory of Open Access Journals (Sweden)

    Fan Vincent C

    2006-05-01

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

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

    Directory of Open Access Journals (Sweden)

    Stonecipher KG

    2013-10-01

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

  11. Managing your eye unit's supplies

    OpenAIRE

    Rd, Thulsiraj

    2011-01-01

    In order to deliver eye care, many resources have to be in place at the right time: your patients, your staff, your facilities, your equipment, and your supplies. In this article, we focus on how you can manage your supplies to ensure that your eye service runs smoothly. These supplies, or consumables, include every little thing needed in the course of your daily work: IOLs, medicines, gloves, forms used for patient care, housekeeping supplies, and equipment spares. If any of these items beco...

  12. Eye tracking disturbances in Schizophrenia

    OpenAIRE

    Sharma Pradeep; Aslanm Baljeet Saba; Saxena Shekhar

    2000-01-01

    Purpose: To study the frequency of different types of eye tracking disturbances in schizophrenia. Materials and Methods: Smooth pursuit eye movements were studied by electro-oculography (EOG) in 22 schizophrenic patients (ICD-10 criteria) and 15 age and sex-matched controls. The studied parameters included average pursuit gain, number of saccades, the frequency of different types of saccades (catch-up, back-up, anticipatory saccades), and disturbances during fixation. The results were analyse...

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

    Otting, William D.; Hunt, Maribeth E.; Ashe, Thomas L.

    1992-01-01

    The results are presented of a systematic series of studies leading to the selection and conceptual design development of a Dynamic Isotope Power System (DIPS) module for lunar and Martian surface applications. An optimum system configuration has been developed for the module that provides a system with a radiator area which is small and manageable without significantly impacting the system mass, efficiency, and technological risk. The maximum design temperature for the system has been determined.

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

    DEFF Research Database (Denmark)

    Mardanbeigi, Diako; Witzner Hansen, Dan

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

  17. Cluster eye camera using microlenses on parabolic surface

    Science.gov (United States)

    Shen, Hui-Kai; Su, Guo-Dung J.

    2013-10-01

    There are two main types of imaging systems that exist in nature: the single aperture eye and the compound eye. Usually, cameras and most of artificial imaging systems are similar to the single aperture eye. But compound lenses can be more compact than single lenses. Our design is based on insect compound eyes, which also have a wide field of view (FOV). With the rise of micro-optical techniques, fabricating compound lenses has become easier. The simplest form of a curved microlens array is a parabolic surface. In this paper, we proposed a multi-channel imaging system, which combines the principles of the insect compound eye and the human eye. The optical system enables the reduction of track length of the imaging optics to achieve miniaturization. With the aid of optical engineering software ZEMAX, the multi-channel structure is simulated by a curved microlens array, and we use a Hypergon lens as the main lens to simulate the human eye, which can achieve the purpose of the wide FOV. With this architecture, each microlens of a microlens array transmits a segment of the overall FOV. The partial images that are separately recorded in different channels are stitched together to form the final image of the whole FOV by software processing. A 2.74 mm thin imaging system with 59 channels and 90° FOV is optimized using ZEMAX sequential ray tracing software on a 6.16 mm × 4.62 mm image plane. Finally, we will discuss the simulation results of this system and compare it with the optical cluster eye system and a mobile phone patent.

  18. Model-Based Eye Detection and Animation

    OpenAIRE

    Trejo Guerrero, Sandra

    2006-01-01

    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...

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

    Scientific Electronic Library Online (English)

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

    2014-07-30

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

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

    Science.gov (United States)

    ... Usage & Eye Strain Maintaining Your Sight with Diabetes Sports and Eye Protection Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips Avoid Indoor Tanning Studies show UV exposure from tanning beds can cause eye damage and skin cancer. Not the look you're ...

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

    DEFF Research Database (Denmark)

    Pietroni, C.; Andersen, J.D.

    2013-01-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

  3. Eye model with controllable lens scattering

    OpenAIRE

    Paeglis, R.; Ozolinsh, M.; Cikmacs, P.; Andersson-engels, Stefan

    2001-01-01

    A model of human eye for experiments in vision research has been developed using PLZT ceramics. This ``artificial eye{''} allows to simulate light scattering caused by cataract in the eye lens. Light scattering of a composite eye lens of the model depends on the electric field applied to a transparent electrooptic PLZT ceramics plate that is attached directly to the lens. The image degradation in such a model eye at various degrees of scattering is studied observing and recording the ...

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

    CERN Document Server

    Nakano, Yukiko I; Bader, Thomas

    2013-01-01

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

  5. Optimizations and Applications in Head-Mounted Video-Based Eye Tracking

    Science.gov (United States)

    Li, Feng

    2011-01-01

    Video-based eye tracking techniques have become increasingly attractive in many research fields, such as visual perception and human-computer interface design. The technique primarily relies on the positional difference between the center of the eye's pupil and the first-surface reflection at the cornea, the corneal reflection (CR). This…

  6. An Examination of Cognitive Processing of Multimedia Information Based on Viewers' Eye Movements

    Science.gov (United States)

    Liu, Han-Chin; Chuang, Hsueh-Hua

    2011-01-01

    This study utilized qualitative and quantitative designs and eye-tracking technology to understand how viewers process multimedia information. Eye movement data were collected from eight college students (non-science majors) while they were viewing web pages containing different types of text and illustrations depicting the mechanism of…

  7. The Design Process of Physical Security as Applied to a U.S. Border Point of Entry

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, G.G.

    1998-10-26

    This paper describes the design process of physical security as applied to a U.S. Border Port of Entry (PoE). Included in this paper are descriptions of the elements that compose U.S. border security. The physical security design will describe the various elements that make up the process as well as the considerations that must be taken into account when dealing with system integration of those elements. The distinctions between preventing unlawful entry and exit of illegal contraband will be emphasized.

  8. Eye movements reset visual perception.

    Science.gov (United States)

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

    2012-01-01

    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

  9. Drugs affecting the eye.

    Science.gov (United States)

    Taylor, F

    1985-08-01

    This discussion reviews drugs that affect the eye, including antihyperglycemic agents; corticosteroids; antirheumatic drugs (quinolines, indomethacin, and allopurinol); psychiatric drugs (phenothiazine, thioridazine, and chlorpromazine); drugs used in cardiology (practolol, amiodarone, and digitalis gylcosides); drugs implicated in optic neuritis and atrophy, drugs with an anticholinergic action; oral contraceptives (OCs); and topical drugs and systemic effects. Refractive changes, either myopic or hypermetropic, can occur as a result of hyperglycemia, and variation in vision is sometimes a presenting symptom in diabetes mellitus. If it causes a change in the refraction, treatment of hyperglycemia almost always produces a temporary hypermetropia. A return to the original refractive state often takes weeks, sometimes months. There is some evidence that patients adequately treated with insulin improve more rapidly than those taking oral medication. Such patients always should be referred for opthalmological evaluation as other factors might be responsible, but it might not be possible to order the appropriate spectacle correction for some time. The most important ocular side effect of the systemic adiministration of corticosteroids is the formation of a posterior subcapsular cataract. Glaucoma also can result from corticosteroids, most often when they are applied topically. Corticosteroids have been implicated in the production of benign intracranial hypertension, which is paradoxical because they also are used in its treatment. The most important side effect of drugs such as chloroquine and hydroxychloroquine is an almost always irreversible maculopathy with resultant loss of central vision. Corneal and retinal changes similar to those caused by the quinolines have been reported with indomethacin, but there is some question about a cause and effect relationship. The National Registry of Drug Induced Ocular Side Effects in the US published 30 case histories of cataract suspected to be induced by allopurinol; numerous additional cases have been reported to the registry since. Phenothiazine, with an estimated 3% incidence of side effects, appears to be safer than other antipsychotic drugs, but the rate of ocular effects increases with the duration of therapy. Thioridazine and chlorpromazine are known to cause lens deposits and pigmentary retinopathy. There is a significantly high prevalence of thrombophlebitis and pseudotumor cerebri among women who use OCs and thrombotic retinal vascular disease, such as retinal vein occulsion, might be linked with them. It also is probable that, because of altered hydration of the cornea, there is a decreased tolerance to contact lenses. PMID:2864912

  10. 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

  11. Design of turn-around-point long-period gratings in a photonic crystal fiber for refractometry of gases.

    Czech Academy of Sciences Publication Activity Database

    Ka?ka, Ji?í

    2013-01-01

    Ro?. 182, ?. 6 (2013), s. 16-24. ISSN 0925-4005 R&D Projects: GA MŠk(CZ) LD11030; GA MŠk(CZ) LF11001 Institutional support: RVO:67985882 Keywords : Fiber design * Photonic crystal fiber * Microstructured optical fiber Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.840, year: 2013

  12. The construction of a model eye for investigation of laser-tissue interactions in scanning laser ophthalmoscopy.

    OpenAIRE

    Rakebrandt, F.; North, Rv; Erichsen, Jt; Drasdo, N.; Fowler, C.; Cowey, A.; Morgan, Je

    2003-01-01

    PURPOSE: To develop a model eye to study laser-tissue interactions during retinal imaging with scanning ophthalmoscopy. METHODS: A model eye was designed to match the optical properties of the human eye based on the Bennett and Rabbetts schematic eye. RESULTS: Alterations in axial length resulted in changes in refractive error similar to those in the human eye (3.70 D for 1 mm in axial length). Perfusion-fixed retinal tissue could be successfully imaged using the Heidelberg Retina Tomograph a...

  13. An eye behavior measuring device for VR system

    Science.gov (United States)

    Lin, Chern-Sheng

    2002-12-01

    This work presents an eye-tracking and pupil size-measuring device that interfaces with a computer for applications useful in psychometry, ophthalmology, physiology and virtual reality (VR) systems. This system utilizes a change-coupled device (CCD) camera, appropriate lenses, PC with frame grabber and a DSP unit with various types of VR equipment, i.e., HMD, simulator or LCD projection device. The digital signal processing unit is used to calculate the average brightness and contrast of the VR video image. A CCD camera with various attachments can be mounted on various VR systems to capture the human eye image for testing. An image capture card and a personal computer are used to analyze the test image. From the eye digital image, the computer obtains data on the pupil size and a trace of the tested eye. A pattern recognition computer program and five measurement parameters are used to distinguish the position of the pupil, calculate the pupil location coordinate and analyze the physical conditions of the user. These data can be plotted against the average brightness and contrast of the VR video image in real time. This information is shown on the screen of a personal computer and used for cross-link analysis. This eye-tracking interface can determine the position of a subject's pupil and map that position into a display point on a computer screen. The pupil size and location data versus the average brightness and contrast of a VR video image are computed in real time.

  14. Process of Designing Robust, Dependable, Safe and Secure Software for Medical Devices: Point of Care Testing Device as a Case Study

    Directory of Open Access Journals (Sweden)

    Sivanesan Tulasidas

    2013-08-01

    Full Text Available This paper presents a holistic methodology for the design of medical device software, which encompasses of a new way of eliciting requirements, system design process, security design guideline, cloud architecture design, combinatorial testing process and agile project management. The paper uses point of care diagnostics as a case study where the software and hardware must be robust, reliable to provide accurate diagnosis of diseases. As software and software intensive systems are becoming increasingly complex, the impact of failures can lead to significant property damage, or damage to the environment. Within the medical diagnostic device software domain such failures can result in misdiagnosis leading to clinical complications and in some cases death. Software faults can arise due to the interaction among the software, the hardware, third party software and the operating environment. Unanticipated environmental changes and latent coding errors lead to operation faults despite of the fact that usually a significant effort has been expended in the design, verification and validation of the software system. It is becoming increasingly more apparent that one needs to adopt different approaches, which will guarantee that a complex software system meets all safety, security, and reliability requirements, in addition to complying with standards such as IEC 62304. There are many initiatives taken to develop safety and security critical systems, at different development phases and in different contexts, ranging from infrastructure design to device design. Different approaches are implemented to design error free software for safety critical systems. By adopting the strategies and processes presented in this paper one can overcome the challenges in developing error free software for medical devices (or safety critical systems.

  15. Mirror coatings for eye-safe laser generation

    Science.gov (United States)

    Tenev, T. K.; Miloushev, I. K.; Peyeva, R. A.

    2010-04-01

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

  16. Mirror coatings for eye-safe laser generation

    International Nuclear Information System (INIS)

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

  17. Design and implementation of a beam-waveguide mirror control system for vernier pointing of the DSS-13 antenna

    Science.gov (United States)

    Alvarez, L. S.; Moore, M.; Veruttipong, W.; Andres, E.

    1994-01-01

    The design and implementation of an antenna beam-waveguide (BWG) mirror position control system at the DSS-13 34-m antenna is presented. While it has several potential applications, a positioner on the last flat-plate BWG mirror (M6) at DSS 13 is installed to demonstrate the conical scan (conscan) angle-tracking technique at the Ka-band (32-GHz) operating frequency. Radio frequency (RF) beam-scanning predictions for the M6 mirror, computed from a diffraction analysis, are presented. From these predictions, position control system requirements are then derived. The final mechanical positioner and servo system designs, as implemented at DSS 13, are illustrated with detailed design descriptions given in the appendices. Preliminary measurements of antenna Ka-band beam scan versus M6 mirror tilt made at DSS 13 in December 1993 are presented. After reduction, the initial measurements are shown to be in agreement with the RF predicts. Plans for preliminary conscan experimentation at DSS 13 are summarized.

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

    Science.gov (United States)

    Hübner, N-O; Fleßa, S; Haak, J; Wilke, F; Hübner, C; Dahms, C; Hoffmann, W; Kramer, A

    2011-01-01

    Recently, the HACCP (Hazard Analysis and Critical Control Points) concept was proposed as possible way to implement process-based hygiene concepts in clinical practice, but the extent to which this food safety concept can be transferred into the health care setting is unclear. We therefore discuss possible ways for a translation of the principles of the HACCP for health care settings. While a direct implementation of food processing concepts into health care is not very likely to be feasible 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. PMID:22242105

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

    Directory of Open Access Journals (Sweden)

    Hübner, N.-O.

    2011-01-01

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

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

    International Nuclear Information System (INIS)

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

  1. Tracking with the mind's eye

    Science.gov (United States)

    Krauzlis, R. J.; Stone, L. S.

    1999-01-01

    The two components of voluntary tracking eye-movements in primates, pursuit and saccades, are generally viewed as relatively independent oculomotor subsystems that move the eyes in different ways using independent visual information. Although saccades have long been known to be guided by visual processes related to perception and cognition, only recently have psychophysical and physiological studies provided compelling evidence that pursuit is also guided by such higher-order visual processes, rather than by the raw retinal stimulus. Pursuit and saccades also do not appear to be entirely independent anatomical systems, but involve overlapping neural mechanisms that might be important for coordinating these two types of eye movement during the tracking of a selected visual object. Given that the recovery of objects from real-world images is inherently ambiguous, guiding both pursuit and saccades with perception could represent an explicit strategy for ensuring that these two motor actions are driven by a single visual interpretation.

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

    OpenAIRE

    Rooij, R. M.

    2005-01-01

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

  3. Design of Phase Array Antenna Using Least Mean Square Algorithm: The Use of Point Sources and Micro-strip Patch Antennas

    Directory of Open Access Journals (Sweden)

    A. Abubakar Mas’ud

    2015-01-01

    Full Text Available In this study, a phased array antenna was designed using modified Least Mean Square algorithm, to adaptively track incident signals from satellite. The algorithms would form the beam perfectly and the main beam will be centered at the location of the desired signal and the nulls will be located at exactly the direction of the unwanted signals. The main beam and nulls would be steered toward incident signals automatically during adaptation process. The phased linear array using both point sources and micro-strip rectangular patch was designed. 8-elements with 0.5 wavelength separation were used. It was found that with micro-strip antenna sources placed along one of the axis, the algorithm gives a lower side lobe which gives best cancellation of interferers from other satellites with higher directivity and lower half-power beam widths.

  4. Multimodal 'eyes-free' interaction techniques for wearable devices

    OpenAIRE

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

    2003-01-01

    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. ...

  5. Keratoglobus: An experience at a tertiary eye care center in India

    Science.gov (United States)

    Rathi, Varsha M; Murthy, Somasheila I; Bagga, Bhupesh; Taneja, Mukesh; Chaurasia, Sunita; Sangwan, Virender S

    2015-01-01

    Context: This study was carried out as a part of an internal audit and is the largest series of patients having keratoglobus, published in the literature. Poor visual acuity of the patients indicates the blinding nature of the disease. Aims: We report our experience with patients having keratoglobus at a tertiary eye care center in India. Settings and Design: Retrospective study. Materials and Methods: We analyzed adults and pediatric patients (20/40 in 6/42 (14.3%) pediatric eyes and 15/53 (28.30%) adults. Visual acuity ranging from counting of fingers to no light perception was noted in 20/53 (37.74%) adults and 21/42 (50%) pediatric patients; 13/20 (65%) with blue sclera and 8/22 eyes (36.37%) without blue sclera. Vernal keratoconjunctivitis was present in one pediatric patient. Choroidal osteoma, retinitis pigmentosa, and retinal detachment were present in adults. Surgeries performed were corneal tear repair (5 eyes), tissue adhesive application (2 eyes), descematopexy (4 eyes) and penetrating keratoplasty (PK - 8 eyes: Three had post-PK glaucoma, graft failure-one eye, 4 patients wore scleral lens - prosthetic replacement of the ocular surface ecosystem). Conclusions: About 50% of pediatric eyes (65% having blue sclera) had no functional vision. Trivial trauma was responsible for corneal rupture indicating need for protective glasses. About 50% patients had post-PK glaucoma though grafts were clear. PMID:25971168

  6. [Design of a Hazard Analysis and Critical Control Points (HACCP) plan to assure the safety of a bologna product produced by a meat processing plant].

    Science.gov (United States)

    Bou Rached, Lizet; Ascanio, Norelis; Hernández, Pilar

    2004-03-01

    The Hazard Analysis and Critical Control Point (HACCP) is a systematic integral program used to identify and estimate the hazards (microbiological, chemical and physical) and the risks generated during the primary production, processing, storage, distribution, expense and consumption of foods. To establish a program of HACCP has advantages, being some of them: to emphasize more in the prevention than in the detection, to diminish the costs, to minimize the risk of manufacturing faulty products, to allow bigger trust to the management, to strengthen the national and international competitiveness, among others. The present work is a proposal based on the design of an HACCP program to guarantee the safety of the Bologna Special Type elaborated by a meat products industry, through the determination of hazards (microbiological, chemical or physical), the identification of critical control points (CCP), the establishment of critical limits, plan corrective actions and the establishment of documentation and verification procedures. The used methodology was based in the application of the seven basic principles settled down by the Codex Alimentarius, obtaining the design of this program. In view of the fact that recently the meat products are linked with pathogens like E. coli O157:H7 and Listeria monocytogenes, these were contemplated as microbiological hazard for the establishment of the HACCP plan whose application will guarantee the obtaining of a safe product. PMID:15332359

  7. If I Had - Dry Eyes

    Medline Plus

    Full Text Available ... Lower in Migraine Sufferers, Cognitive Decline Seen in Older Adults with Severe COPD VIDEO: If I Had - Dry Eyes - Dr. Penny Asbell, MD, FACS, MBA, Professor of Ophthalmology, Mount Sinai School of Medicine, New York Back to Home Page ...

  8. Building the eye care team

    Directory of Open Access Journals (Sweden)

    Thulasiraj Ravilla

    2014-07-01

    Full Text Available 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.

  9. 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)

  10. Deformable Models for Eye Tracking

    DEFF Research Database (Denmark)

    Vester-Christensen, Martin; Leimberg, Denis

    2005-01-01

    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.

  11. Arthropods affecting the human eye.

    Science.gov (United States)

    Panadero-Fontán, Rosario; Otranto, Domenico

    2015-02-28

    Ocular infestations by arthropods consist in the parasitization of the human eye, either directly (e.g., some insect larvae causing ophthalmomyiasis) or via arthropods feeding on lachrymal/conjunctival secretions (e.g., some eye-seeking insects, which also act as vectors of eye pathogens). In addition, demodicosis and phthiriasis may also cause eye discomfort in humans. Ophthalmomyiasis by larvae of the families Oestridae, Calliphoridae and Sarcophagidae, are frequent causative agents of human ocular infestations. Over the last decades, the extensive use of macrocyclic lactones in cattle has reduced the frequency of infestations by Hypoderma bovis and Hypoderma lineatum (family Oestridae), and consequently, human infestations by these species. A prompt diagnosis of ocular myiasis (e.g., by serological tests) is pivotal for positive prognoses, particularly when the larvae are not detectable during the ophthalmologic examination. Molecular diagnoses may also assist physicians and parasitologists in achieving time-efficient diagnoses of infestations by Oestridae causing myiasis. Finally, due to widespread international travel to exotic destinations, cases of myiasis are increasing in non-endemic areas, therefore requiring physicians to acquire a profound knowledge of the clinical symptoms linked to these infestations to prevent costly, inappropriate treatments or severe complications. PMID:25620292

  12. An eye-opening experience

    OpenAIRE

    Gandhi, Sunil P.; Cang, Jianhua; Stryker, Michael P.

    2005-01-01

    Many aspects of visual development are known to depend on activity. Two recent reports of rapid rewiring of connections in visual cortex and superior colliculus make clear that eye opening is an important event in the maturation of the visual system.

  13. If I Had - Dry Eyes

    Medline Plus

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

  14. Autologous Serum In Eye Disorders

    OpenAIRE

    Priyanka Sodani Mahajan

    2009-01-01

    While pharmaceutical lubricants offer little to nonutrition, eye drops made from autologous serum havea tear like biochemical character and supply nutritionalcomponents. In vitro studies have shown that serumsupports viability, proliferation and migration of ocularsurface epithelial cells better than unpreservedpharmaceutical tear substitutes. The productionparameters should be optimized before a meaningfulrandomized, controlled clinical trial attempts toevaluate the real therapeutic potentia...

  15. If I Had - Dry Eyes

    Medline Plus

    Full Text Available ... and they got together and put together a report called the DEWS Report, the Dry Eye WorkShop. And we have classified ... artificial tears are the same. You need to figure out which one is going to work for ...

  16. Frog eye, ear, and nostril

    Science.gov (United States)

    Ren West (None; )

    2006-08-07

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

  17. If I Had - Dry Eyes

    Medline Plus

    Full Text Available ... 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 figure out which one is going to work for you ...

  18. Microcystic Inner Nuclear Layer Changes and Retinal Nerve Fiber Layer Defects in Eyes with Glaucoma

    Science.gov (United States)

    Hasegawa, Tomoko; Akagi, Tadamichi; Yoshikawa, Munemitsu; Suda, Kenji; Yamada, Hiroshi; Kimura, Yugo; Nakanishi, Hideo; Miyake, Masahiro; Unoki, Noriyuki; Ikeda, Hanako Ohashi; Yoshimura, Nagahisa

    2015-01-01

    Objective To examine microcystic inner nuclear layer (INL) changes in glaucomatous eyes and to determine associated factors. Design Retrospective, cross-sectional, observational study. Methods Two hundred seventeen eyes of 133 patients with primary open angle glaucoma (POAG), 41 eyes of 32 patients with preperimetric glaucoma and 181 normal eyes of 117 subjects were ultimately included. Microcystic INL lesions were examined with infrared fundus images and with 19 vertical spectral domain optical coherence tomography (SD-OCT) images in the macular area. Results Microcystic INL changes were observed in 6.0% of eyes with POAG, but none of the normal eyes or eyes with preperimetric glaucoma showed microcystic INL changes. The proportion of eyes with advanced glaucoma was significantly larger (P = 0.013) in eyes with microcystic lesions than without. The visual field mean deviation (MD) slope was also significantly worse (P = 0.027) in eyes with microcystic lesions. No significant differences were observed in age, sex, refraction, axial length, intraocular pressure, or MD value between eyes with and without microcystic INL lesions. In several cases, microcystic INL lesions occurred along with glaucomatous visual field progression. The retinal nerve fiber layer (RNFL) thickness (P = 0.013) and ganglion cell layer (GCL) + inner plexiform layer thickness (P = 0.023) were significantly lower in areas with microcystic lesions than without. The INL was also significantly thicker (P = 0.002) in areas with microcystic lesions. Conclusions Microcystic INL lesions in glaucomatous eyes are closely associated with RNFL and GCL thinning and correlated with worse MD slope. These INL lesions may indicate focal and progressive damage in glaucoma. PMID:26066021

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

    Directory of Open Access Journals (Sweden)

    Mariya A. Dikovskaya

    2013-08-01

    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.

  20. Introduction to Symptoms of Eye Disorders

    Science.gov (United States)

    ... Unequal Vision, Blurred Vision, Double Changes in the Appearance of the Eyes Vision Loss, Sudden Other Eye Symptoms NOTE: This is the Consumer Version. CONSUMERS: Click here for the Professional Version ...

  1. Eye Health in Sports and Recreation

    Science.gov (United States)

    ... to Z Age-related Macular Degeneration (AMD) Allergies Amblyopia (Lazy Eye) Astigmatism Bacterial Keratitis Bell's Palsy Blepharitis ... Refractive Surgery & LASIK Sunglasses Living EyeSmart About Ophthalmologists Adults Under 40 Adults 40 to 60 Adults Over ...

  2. Children's Eye Injuries: Prevention and Care

    Science.gov (United States)

    ... to Z Age-related Macular Degeneration (AMD) Allergies Amblyopia (Lazy Eye) Astigmatism Bacterial Keratitis Bell's Palsy Blepharitis ... Refractive Surgery & LASIK Sunglasses Living EyeSmart About Ophthalmologists Adults Under 40 Adults 40 to 60 Adults Over ...

  3. Dry Eyes and Glaucoma: Double Trouble

    Science.gov (United States)

    Dry Eyes and Glaucoma: Double Trouble email Send this article to a friend by filling out the fields below: Your name: Your friend's ... heating and cooling systems. Treating Dry Eye and Glaucoma Usually a combination of treatments is helpful, and ...

  4. Oculometer for remote tracking of eye movement

    Science.gov (United States)

    Mason, K. A.; Merchant, J.

    1969-01-01

    Prototype oculometer which tracks lateral eye position and measures the direction of the eyes optical axis, pupil size, and blink occurrence performs measurements on the subject on a real-time basis from a remote location.

  5. A history of eye gaze tracking

    OpenAIRE

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

    2007-01-01

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

  6. Prescriptions for Eye Glasses and Contact Lenses

    Science.gov (United States)

    ... página en español Prescriptions for Eye Glasses and Contact Lenses Related Items The Basics of LASIK Eye Surgery Buying Cosmetic Contact Lenses? Millions of Americans wear glasses or contact lenses. ...

  7. The Trajectories of Saccadic Eye Movements.

    Science.gov (United States)

    Bahill, A. Terry; Stark, Lawrence

    1979-01-01

    Investigates the trajectories of saccadic eye movements, the control signals of the eye, and nature of the mechanisms that generate them, using the techniques of bioengineering in collecting the data. (GA)

  8. Visually stimulated brain-computer interfaces compete with eye tracking interfaces when using small targets.

    Science.gov (United States)

    Suefusa, Kaori; Tanaka, Toshihisa

    2014-01-01

    Visually stimulated brain-computer interfacing detects which target on a screen a user is gazing at; however, this is also accomplished by tracking gaze points with a camera. These two approaches have been independently investigated and sometimes doubts about BCI with visual stimuli are raised in terms of usability compared to eye tracking interfaces (ETI). This paper answers this question by investigating information transfer rates (ITR) and recognition accuracies of BCI and ETI having a similar interface design, where subjects were asked to gaze at one of four targets on a screen. Experimental results revealed that BCI is comparable in ITR to ETI and had better performance for relatively small targets on the screen. PMID:25570870

  9. Ramverk för eye tracking-simulering

    OpenAIRE

    Wide?n, Tobias

    2013-01-01

    To facilitate eye tracking algorithm development that would benefit from simulation we created an eye tracking simulation software library and Application Programming Interface with reusable components. The main part of this library consists of a simulation core able to accept different geometrical models for the eyes, depiction mechanisms, illumination sources and eye tracking algorithms. The library has support for data generation using these models as partial input. It is also capable of p...

  10. Functional analysis and treatment of eye poking.

    OpenAIRE

    Kennedy, C. H.; Souza, G.

    1995-01-01

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

  11. Visual representations during saccadic eye movements

    OpenAIRE

    Moore, Tirin; Tolias, Andreas S.; Schiller, Peter H.

    1998-01-01

    In normal vision, shifts of attention are usually followed by saccadic eye movements. Neurons in extrastriate area V4 are modulated by focal attention when eye movements are withheld, but they also respond in advance of visually guided saccadic eye movements. We have examined the visual selectivity of saccade-related responses of area V4 neurons in monkeys making delayed eye movements to receptive field stimuli of varying orientation. This task did not require the monkey to attend to orientat...

  12. Eye injuries associated with war games

    OpenAIRE

    Easterbrook, Michael; Pashby, Thomas J.

    1985-01-01

    War games, an outdoor activity combining recreation, military maneuvers and fantasy, are becoming a popular recreational sport. Increasing numbers of players are suffering eye injuries. In the last year 26 cases of serious eye injuries were reported to Canadian ophthalmologists; in 15 eyes vision was reduced to 6/24 or less. Although eyeguards are provided, all the injuries had occurred when the participants were not wearing them. Methods of preventing eye injuries in war games are discussed.

  13. An improved likelihood model for eye tracking

    DEFF Research Database (Denmark)

    Hansen, Dan Witzner; Hammoud, Riad I.

    2007-01-01

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

  14. Experiencing Light's Properties within Your Own Eye

    Science.gov (United States)

    Mauser, Michael

    2011-01-01

    Seeing the reflection, refraction, dispersion, absorption, polarization, and scattering or diffraction of light within your own eye makes these properties of light truly personal. There are practical aspects of these within the eye phenomena, such as eye tracking for computer interfaces. They also offer some intriguing diversions, for example,…

  15. Advances in Eye Tracking in Infancy Research

    Science.gov (United States)

    Oakes, Lisa M.

    2012-01-01

    In 2004, McMurray and Aslin edited for "Infancy" a special section on eye tracking. The articles in that special issue revealed the enormous promise of automatic eye tracking with young infants and demonstrated that eye-tracking procedures can provide significant insight into the emergence of cognitive, social, and emotional processing in infancy.…

  16. Functional Analysis and Treatment of Eye Poking.

    Science.gov (United States)

    Kennedy, Craig H.; Souza, Geri

    1995-01-01

    Four studies analyzed eye poking behavior of a youth with profound disabilities. Results demonstrated substantive reductions in the frequency of eye poking when goggles were worn and when a video game was provided as a competing source of visual stimulation and as a reinforcer. Music was less effective in reducing eye poking. (Author/DB)

  17. Eye Gaze in Creative Sign Language

    Science.gov (United States)

    Kaneko, Michiko; Mesch, Johanna

    2013-01-01

    This article discusses the role of eye gaze in creative sign language. Because eye gaze conveys various types of linguistic and poetic information, it is an intrinsic part of sign language linguistics in general and of creative signing in particular. We discuss various functions of eye gaze in poetic signing and propose a classification of gaze…

  18. Visibility of wearable sensors as measured using eye tracking glasses

    OpenAIRE

    King, Meggan; Hu, Feiyan; Mchugh, Joanna; Murphy, Emma; Newman, Eamonn; Irving, Kate; Smeaton, Alan F.

    2013-01-01

    Sensor technologies can enable independent living for people with dementia by monitoring their behaviour and identifying points where support may be required. Wearable sensors can provide such support but may constitute a source of stigma for the user if they are perceived as visible and therefore obtrusive. This paper presents an empirical investigation exploring the extent to which wearable sensors are perceived as visible. 23 Participants wore eye tracking glasses, which superimposed the l...

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

    Medline Plus

    Full Text Available ... Adults Over 60 Babies, Children & Teenagers Computer Usage Diabetes Diet & Nutrition Eye Injuries Eye Screening Guidelines Home ... Computer Usage & Eye Strain Maintaining Your Sight with Diabetes Sports and Eye Protection Eyesight Risks for Smokers ...

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

    Medline Plus

    Full Text Available ... Sun Eye Health News Consumer Alerts Are 3-D Movies Bad for Your Eyes? Tweet Eye Health ... computer use and your eyes . Children and 3-D Technology Following the lead of Nintendo, several 3- ...

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

    Medline Plus

    Full Text Available ... Marijuana for Glaucoma Pregnancy Preventing Eye Injuries Smokers Sports Using Eye Makeup Veterans What Is an Ophthalmologist? ... Usage & Eye Strain Maintaining Your Sight with Diabetes Sports and Eye Protection Eyesight Risks for Smokers Veterans & ...

  2. Large incidence angle and defocus influence cat's eye retro-reflector

    Science.gov (United States)

    Zhang, Lai-xian; Sun, Hua-yan; Zhao, Yan-zhong; Yang, Ji-guang; Zheng, Yong-hui

    2014-11-01

    Cat's eye lens make the laser beam retro-reflected exactly to the opposite direction of the incidence beam, called cat's eye effect, which makes rapid acquiring, tracking and pointing of free space optical communication possible. Study the influence of cat's eye effect to cat's eye retro-reflector at large incidence angle is useful. This paper analyzed the process of how the incidence angle and focal shit affect effective receiving area, retro-reflected beam divergence angle, central deviation of cat's eye retro-reflector at large incidence angle and cat's eye effect factor using geometrical optics method, and presented the analytic expressions. Finally, numerical simulation was done to prove the correction of the study. The result shows that the efficiency receiving area of cat's eye retro-reflector is mainly affected by incidence angle when the focal shift is positive, and it decreases rapidly when the incidence angle increases; the retro-reflected beam divergence and central deviation is mainly affected by focal shift, and within the effective receiving area, the central deviation is smaller than beam divergence in most time, which means the incidence beam can be received and retro-reflected to the other terminal in most time. The cat's eye effect factor gain is affected by both incidence angle and focal shift.

  3. Constructing a Computer Model of the Human Eye Based on Tissue Slice Images

    Directory of Open Access Journals (Sweden)

    Chunbo Bao

    2010-01-01

    Full Text Available Computer simulation of the biomechanical and biological heat transfer in ophthalmology greatly relies on having a reliable computer model of the human eye. This paper proposes a novel method on the construction of a geometric model of the human eye based on tissue slice images. Slice images were obtained from an in vitro Chinese human eye through an embryo specimen processing methods. A level set algorithm was used to extract contour points of eye tissues while a principle component analysis was used to detect the central axis of the image. The two-dimensional contour was rotated around the central axis to obtain a three-dimensional model of the human eye. Refined geometric models of the cornea, sclera, iris, lens, vitreous, and other eye tissues were then constructed with their position and ratio relationships kept intact. A preliminary study of eye tissue deformation in eye virtual surgery was simulated by a mass-spring model based on the computer models developed.

  4. Near-to-eye display based on retinal scanning and a diffractive exit-pupil expander

    Science.gov (United States)

    Äyräs, Pekka; Saarikko, Pasi

    2010-05-01

    In this paper, we propose a novel design to construct a near-to-eye display with an appearance resembling that of a regular eye wear. Our design combines a scanning display engine with a diffractive exit pupil expander. Both of these components have been used separately earlier, but we propose to combine them in a single device. This allows the construction of a smaller and lighter display system, as well as a more power efficient design as compared to traditional micro display based systems. In our design the light source can be moved away from the display to decrease the weight and size. An exit-pupil expander based on diffractive optics allows a size and weight efficient way to build a near-to-eye display with a large exit pupil. A large exit pupil is desired in near-to-eye displays to accommodate the eye movements and to improve the comfort and ease of the use. The diffractive exit-pupil expander also allows a switchable see-through feature; enabling the viewer the see the surroundings together with the displayed information. In the paper the operation and the design of the proposed near-to-eye display are described. We also present modeling results that support the validity of the design, and finally some preliminary measurement results are given.

  5. The management of allergic eye diseases in primary eye care.

    Science.gov (United States)

    Chigbu, DeGaulle I

    2009-12-01

    Allergy is an over-reaction of the body's immune system to innocuous foreign substances or allergens that the body perceives as a potential threat or undesirable. It is estimated to affect approximately 20% of the population. Of this subset at least 20% suffer from ocular allergy. It has a significant impact on the quality of life of the individual. Allergic diseases are those conditions in which an antibody- and/or T-cell mediated mechanisms are involved. Allergic eye diseases are characterized by IgE-mast cell mediated, as seen in allergic conjunctivitis; chronic mast cell activation and eosinophil/T-lymphocyte-mediated response, as seen in giant papillary conjunctivitis, vernal keratoconjunctivitis and atopic keratoconjunctivitis; or a T-lymphocyte-mediated response in contact ocular allergy. The management of allergic eye disease is aimed at preventing the release of mediators of allergy, controlling the allergic inflammatory cascade and preventing ocular surface damage secondary to the allergic response. In the management of ocular allergic disease, the clinician is advised to recommend non-pharmacologic and pharmacologic therapeutic regimens that address the acute presentation of ocular allergy and provide prophylaxis aimed at providing long-term maintenance therapy. This approach to the management of allergic eye diseases aims to minimize the impact of the allergic reaction on the individual's quality of life. To achieve success in the management of allergic eye diseases, the clinician requires a considerable understanding of the pathophysiology, clinical features and differential diagnosis of the different types of ocular allergy, as well as an adequate knowledge of their pharmacotherapy. PMID:19879797

  6. Accuracy of Measurements of Eye-Tracking of a human perception on the screen

    OpenAIRE

    Mazurova, Elena

    2014-01-01

    Abstract: A particular study is a part of the project “Visual Impact” held a t Arcada UAS. The eye-tracking technology is used to track the eye movements by recording fixations and saccades within the time of the test. The eye-tracker records and saves the information that can be presented with heat map, cluster and gaze plots. As all these methods are visual representations of data and don’t show the exact coordinates of the gaze point, this particular work is based on processing th...

  7. Modulation transfer of the human eye as a function of retinal eccentricity

    OpenAIRE

    Navarro, Rafael; Artal, Pablo; Williams, David R

    1993-01-01

    [EN] We measured the monochromatic image quality of the eye across a wide visual field (1200), with natural pupil (4 mm) and accommodation (3 diopters). The method is based on the acquisition and the posterior processing of double-pass aerial images of a point source imaged on the retina, which was kept at a fixed distance from the eye at all retinal eccentricities. The two-dimensional modulation transfer functions (MTF's) computed from the aerial images show that astigmatism is t...

  8. Summation of visual motion across eye movements reflects a non-spatial decision mechanism

    OpenAIRE

    Morris, Adam P.; Liu, Charles C.; Cropper, Simon J.; Forte, Jason D.; Krekelberg, Bart; Jason B Mattingley

    2010-01-01

    Human vision remains perceptually stable even though retinal inputs change rapidly with each eye movement. Although the neural basis of visual stability remains unknown, a recent psychophysical study pointed to the existence of visual feature-representations anchored in environmental rather than retinal coordinates (e.g. ‘spatiotopic’ receptive fields; Melcher, D., and Morrone, M.C. (2003). Spatiotopic temporal integration of visual motion across saccadic eye movements. Nat Neurosci 6, 87...

  9. The character of abnormalities found in eye development of quail embruos exposed under space flight conditions

    Science.gov (United States)

    Grigoryan, E.; Dadheva, O.; Polinskaya, V.; Guryeva, T.

    The avian embryonic eye is used as a model system for studies on the environmental effects on central nervous system development. Here we present results of qualitative investigation of the eye development in quail embryos incubated in micro-"g" environment. In this study we used eyes of Japanese quail (Coturnix coturnix Japonica) embryos "flown" onboard biosatellite Kosmos-1129 and on Mir station within the framework of Mir-NASA Program. Eyes obtained from embryos ranging in age from 3-12 days (E3-E12) were prepared histologically and compared with those of the synchronous and laboratory gound controls. Ther most careful consideration was given to finding and analysis of eye developmental abnormalities. Then they were compared with those already described by experimental teratology for birds and mammals. At the stage of the "eye cup" (E3) we found the case of invalid formation of the inner retina. The latter was represented by disorganized neuroblasts occupying whole posterior chamber of the eye. On the 7th day of quail eye development, at the period of cellular growth activation some cases of small eyes with many folds of overgrowing neural and pigmented retinal layers were detected. In retinal folds of these eyes the normal layering was disturbed as well as the formation of aqueous body and pecten oculi. At this time point the changes were also found in the anterior part of the eye. The peculiarities came out of the bigger width of the cornea and separation of its layers, but were found in synchronous control as well. Few embryos of E10 had also eyes with the abnormities described for E7 but this time they were more vivid because of the completion of eye tissue differentiation. At the stage E12 we found the case evaluated as microphthalmia attending by overgrowth of anterior pigmented tissues - iris and ciliary body attached with the cornea. Most, but not all, of abnormalities we found in eye morphogeneses belonged to the birds "flown" aboard Kosmos- 1129 and were likely induced by specific conditions of that flight. All sorts of disturbances we observed in eye development were similar with dom inated types found in birds and mammals on ground and could be induced by factors we intend to discuss in our report.

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

    Medline Plus

    Full Text Available ... Problems Medical Marijuana for Glaucoma Pregnancy Preventing Eye Injuries Smokers Sports Using Eye Makeup Veterans What Is an Ophthalmologist? ... Eyes? Tweet Eye ... Eye Strain Maintaining Your Sight with Diabetes Sports and Eye Protection Eyesight Risks for Smokers Veterans & ...

  11. What Are You Looking At? Moving toward an Attentional Timeline in Insomnia: A Novel Semantic Eye Tracking Study

    OpenAIRE

    Woods, Hc; Scheepers, C.; Ross, Ka; Espie, Ca; Biello, Sm

    2013-01-01

    STUDY OBJECTIVES: To date, cognitive probe paradigms have been used in different guises to obtain reaction time measurements suggestive of an attention bias towards sleep in insomnia. This study adopts a methodology which is novel to sleep research to obtain a continual record of where the eyes-and therefore attention-are being allocated with regard to sleep and neutral stimuli. DESIGN: A head mounted eye tracker (Eyelink II,SR Research, Ontario, Canada) was used to monitor eye movements in r...

  12. Hidden Communicative Competence: Case Study Evidence Using Eye-Tracking and Video Analysis

    Science.gov (United States)

    Grayson, Andrew; Emerson, Anne; Howard-Jones, Patricia; O'Neil, Lynne

    2012-01-01

    A facilitated communication (FC) user with an autism spectrum disorder produced sophisticated texts by pointing, with physical support, to letters on a letterboard while their eyes were tracked and while their pointing movements were video recorded. This FC user has virtually no independent means of expression, and is held to have no literacy…

  13. Demand, usage and postoperative assesment of the donor cornea and evaluation of the information returning from the Eye Banks

    Directory of Open Access Journals (Sweden)

    Sad?k ?encan

    2005-01-01

    Full Text Available The ophthalmologists who want to make keratoplasty within the borders of Turkey have some legal rights and duties. To make them remember these rights and duties and to protect them from punishment and to teach them the rules of correspondence with the eye banks, the laws of T.C and H.M and the forms of USA Eye Bank Association, Istanbul Medicine Lions Eye Bank, Haseki Eye Bank were explained. The principles of form filling, medical factors affecting the quality of the cornea as well as success of the operation and the legal and medical facts that the surgeon must take into consideration were indicated. The meticulous studies of the eye banks to protect the high standards were pointed out. Lastly, the ophthalmologists were advised to work with experienced and reliable eye banks.

  14. The impact of fatigue on latent print examinations as revealed by behavioral and eye gaze testing.

    Science.gov (United States)

    Busey, Thomas; Swofford, Henry J; Vanderkolk, John; Emerick, Brandi

    2015-06-01

    Eye tracking and behavioral methods were used to assess the effects of fatigue on performance in latent print examiners. Eye gaze was measured both before and after a fatiguing exercise involving fine-grained examination decisions. The eye tracking tasks used similar images, often laterally reversed versions of previously viewed prints, which holds image detail constant while minimizing prior recognition. These methods, as well as a within-subject design with fine grained analyses of the eye gaze data, allow fairly strong conclusions despite a relatively small subject population. Consistent with the effects of fatigue on practitioners in other fields such as radiology, behavioral performance declined with fatigue, and the eye gaze statistics suggested a smaller working memory capacity. Participants also terminated the search/examination process sooner when fatigued. However, fatigue did not produce changes in inter-examiner consistency as measured by the Earth Mover Metric. Implications for practice are discussed. PMID:25918906

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

    Directory of Open Access Journals (Sweden)

    Benelli U

    2011-06-01

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

  16. Management of thyroid eye disease

    International Nuclear Information System (INIS)

    Thyroid eye disease (TED) is the most frequent extrathyroidal manifestation of Graves' disease. In most instances it is mild and non-progressive, but in 3%-5% of cases it is severe. Non-severe TED requires only supportive measures, such as eye ointments, sunglasses and prisms. By contrast, severe TED requires aggressive treatment, either medical (high-dose glucocorticoids, orbital radiotherapy) or surgical (orbital decompression). The choice of treatment relies on the assessment of both TED severity and activity. Removal of controllable risk factors, especially cigarette smoking, is important to improve the course and the therapeutic outcome. A coordinated approach to the treatment of hyperthyroidism and TED is also required. Novel promising treatments, to be verified in large series of patients, include somatostatin analogues and cytokine antagonists. (orig.)

  17. Management of thyroid eye disease

    Energy Technology Data Exchange (ETDEWEB)

    Bartalena, Luigi; Tanda, Maria Laura [Department of Endocrinology, University of Insubria, Ospedale di Circolo, Viale Borri, 57, 21100 Varese (Italy); Marcocci, Claudio; Pinchera, Aldo [Department of Endocrinology and Metabolism, University of Pisa, Pisa (Italy)

    2002-08-01

    Thyroid eye disease (TED) is the most frequent extrathyroidal manifestation of Graves' disease. In most instances it is mild and non-progressive, but in 3%-5% of cases it is severe. Non-severe TED requires only supportive measures, such as eye ointments, sunglasses and prisms. By contrast, severe TED requires aggressive treatment, either medical (high-dose glucocorticoids, orbital radiotherapy) or surgical (orbital decompression). The choice of treatment relies on the assessment of both TED severity and activity. Removal of controllable risk factors, especially cigarette smoking, is important to improve the course and the therapeutic outcome. A coordinated approach to the treatment of hyperthyroidism and TED is also required. Novel promising treatments, to be verified in large series of patients, include somatostatin analogues and cytokine antagonists. (orig.)

  18. How to use… eye swabs.

    Science.gov (United States)

    Drew, Richard J; Cole, Theresa S; Newman, William

    2015-06-01

    Conjunctivitis is a very common presentation to general practitioners and general paediatricians. The investigation of conjunctivitis can be a significant cost to microbiology laboratories due to the high volume of samples that can be submitted, particularly from patients in the community. The key issue is to send eye swabs in clinical situations where it can make a difference to management, and limiting the use of eye swabs in routine cases of conjunctivitis which are likely to be due to viruses. For investigation of neonatal conjunctivitis we recommend sending a bacterial swab for routine culture, and also a swab for molecular detection of Chlamydia trachomatis and Neisseria gonorrhoeae. In older children with mild conjunctivitis no swab is necessary unless there is marked conjunctival injection. In this article we also highlight patient populations that require specialist tests to be sent as part of their assessment such as contact lens wearers and sexually active teenagers. PMID:24523487

  19. Eye Movements in Gaze Interaction

    DEFF Research Database (Denmark)

    MØllenbach, Emilie; Hansen, John Paulin

    2013-01-01

    Gaze as a sole input modality must support complex navigation and selection tasks. Gaze interaction combines specific eye movements and graphic display objects (GDOs). This paper suggests a unifying taxonomy of gaze interaction principles. The taxonomy deals with three types of eye movements: fixations, saccades and smooth pursuits and three types of GDOs: static, dynamic, or absent. This taxonomy is qualified through related research and is the first main contribution of this paper. The second part of the paper offers an experimental exploration of single stroke gaze gestures (SSGG). The main findings suggest (1) that different lengths of SSGG can be used for interaction, (2) that GDOs are not necessary for successful completion, and (3) that SSGG are comparable to dwell time selection.

  20. Real Time Eye Tracking in Unconstrained Environments

    Directory of Open Access Journals (Sweden)

    Majid Tajeri

    2012-07-01

    Full Text Available In this paper, an effective method for human eye tracking and also decreasing the current challenges and problems in its algorithms, possibly as real time and for unconstrained environments has been proposed. In this method, firstly face has been detected and segmented from the remaining parts to make the searching area in tracking stage, narrower and processing speed higher. Then eye area is determined and eye pupils are detected in the specified area. In the proposed method, to support tracking in eye occlusion state, corner detection has been additionally used. Experimental results show the potential of this method for real time eye tracking in unconstrained environments with existence of complex background, head and face rotation, beard, makeup, eye glasses and veil, even while the eyes are closed. The correct recognition rate of the proposed method is about 91.9%.

  1. Reconstruction of eye movements during blinks

    CERN Document Server

    Baptista, M S; Kliegl, R; Engbert, R; Kurths, J

    2008-01-01

    In eye movement research in reading, the amount of data plays a crucial role for the validation of results. A methodological problem for the analysis of the eye movement in reading are blinks, when readers close their eyes. Blinking rate increases with increasing reading time, resulting in high data losses, especially for older adults or reading impaired subjects. We present a method, based on the symbolic sequence dynamics of the eye movements, that reconstructs the horizontal position of the eyes while the reader blinks. The method makes use of an observed fact that the movements of the eyes before closing or after opening contain information about the eyes movements during blinks. Test results indicate that our reconstruction method is superior to methods that use simpler interpolation approaches. In addition, analyses of the reconstructed data show no significant deviation from the usual behavior observed in readers.

  2. Systems and methods of eye tracking calibration

    DEFF Research Database (Denmark)

    Lopez, Javier San Agustin The Department,

    Methods and systems to facilitate eye tracking control calibration are provided. One or more objects are displayed on a display of a device, where the one or more objects are associated with a function unrelated to a calculation of one or more calibration parameters. The one or more calibration parameters relate to a calibration of a calculation of gaze information of a user of the device, where the gaze information indicates where the user is looking. While the one or more objects are displayed, eye movement information associated with the user is determined, which indicates eye movement of one or more eye features associated with at least one eye of the user. The eye movement information is associated with a first object location of the one or more objects. The one or more calibration parameters are calculated based on the first object location being associated with the eye movement information.

  3. Intermediate view synthesis for eye-gazing

    Science.gov (United States)

    Baek, Eu-Ttuem; Ho, Yo-Sung

    2015-01-01

    Nonverbal communication, also known as body language, is an important form of communication. Nonverbal behaviors such as posture, eye contact, and gestures send strong messages. In regard to nonverbal communication, eye contact is one of the most important forms that an individual can use. However, lack of eye contact occurs when we use video conferencing system. The disparity between locations of the eyes and a camera gets in the way of eye contact. The lock of eye gazing can give unapproachable and unpleasant feeling. In this paper, we proposed an eye gazing correction for video conferencing. We use two cameras installed at the top and the bottom of the television. The captured two images are rendered with 2D warping at virtual position. We implement view morphing to the detected face, and synthesize the face and the warped image. Experimental results verify that the proposed system is effective in generating natural gaze-corrected images.

  4. Red eyes in renal failure.

    OpenAIRE

    Klaassen-Broekema, N; VAN BIJSTERVELD, O P

    1992-01-01

    Of 57 patients with chronic renal failure who all had deposition of calcium salts in the conjunctival and corneal tissue two developed a brief episode of painful irritation and redness of the conjunctiva and subconjunctiva. This hyperaemia was adjacent to erosions of the corneal epithelium of the eye as a consequence of exfoliation of calcium concretions from the superficial corneal epithelium. Eight patients showed inflammatory reactions of the conjunctivae that were clinically identical to ...

  5. Sussex Eye Hospital sports injuries.

    OpenAIRE

    Gregory, P T

    1986-01-01

    To assess the prevalence of sports eye injuries in our area a register was kept over the 18 months from October 1982 to March 1984. Squash, association football, badminton, and tennis were the main offenders. The severest injury was from a golf ball, involving a fractured zygoma. There was one retinal dialysis, and one lens dislocation requiring extraction. Spectacles were broken in six cases and a contact lens in one. Glass fragments needed operative removal in one case, but there were no pe...

  6. Nutrients for the aging eye

    OpenAIRE

    Hm, Rasmussen; Ej, Johnson

    2013-01-01

    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-inflam...

  7. Mitochondrial disorders and the eye

    Directory of Open Access Journals (Sweden)

    O’Neill EC

    2011-09-01

    Full Text Available Nicole J Van Bergen, Rahul Chakrabarti, Evelyn C O'Neill, Jonathan G Crowston, Ian A TrounceCentre for Eye Research Australia, Department of Ophthalmology, University of Melbourne, Victoria, AustraliaAbstract: The clinical significance of disturbed mitochondrial function in the eye has emerged since mitochondrial DNA (mtDNA mutation was described in Leber's hereditary optic neuropathy. The spectrum of mitochondrial dysfunction has become apparent through increased understanding of the contribution of nuclear and somatic mtDNA mutations to mitochondrial dynamics and function. Common ophthalmic manifestations of mitochondrial dysfunction include optic atrophy, pigmentary retinopathy, and ophthalmoplegia. The majority of patients with ocular manifestations of mitochondrial disease also have variable central and peripheral nervous system involvement. Mitochondrial dysfunction has recently been associated with age-related retinal disease including macular degeneration and glaucoma. Therefore, therapeutic targets directed at promoting mitochondrial biogenesis and function offer a potential to both preserve retinal function and attenuate neurodegenerative processes.Keywords: mitochondria, disease, retina, eye, aging, neuroprotection

  8. [Perforating eye injuries in children].

    Science.gov (United States)

    Prado Júnior, J; Alves, M R; Kara José, N; Usuba, F S; Onclix, T M; Marantes, C R

    1996-01-01

    The author studied 140 cases of perforating eye injury in children up to 15 years old admitted at the Clinic Hospital of the Medical College of the University of São Paulo (Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo) from January 1989 to December 1993. These cases represent 24.71% of the total of the perforating eye injuries seen during this period, showing a ratio of 76.42% of males, a ratio of 2/1 in the group from 0 to 6 years old, 7/1 in the group from 7 to 11 years old and a ratio of 3/1 in the group from 12 to 15 years old. The most common perforating eye injuries were due to sharp objects (54.71%), contusion (20%), explosions (7.85%) and flying objects (5.71%). The relation between the severity of the injury and the prognosis is emphasized. Safety precautions should be effective in order to reduce frequence and morbidity of these perforating ocular injuries. PMID:9008931

  9. Eye tracking disturbances in Schizophrenia

    Directory of Open Access Journals (Sweden)

    Sharma Pradeep

    2000-01-01

    Full Text Available Purpose: To study the frequency of different types of eye tracking disturbances in schizophrenia. Materials and Methods: Smooth pursuit eye movements were studied by electro-oculography (EOG in 22 schizophrenic patients (ICD-10 criteria and 15 age and sex-matched controls. The studied parameters included average pursuit gain, number of saccades, the frequency of different types of saccades (catch-up, back-up, anticipatory saccades, and disturbances during fixation. The results were analysed statistically. Results: The average pursuit gain was significantly affected in patients for target velocity of 30°/sec (p=0.007. The catch-up and back-up saccades were more common in cases than controls but the difference was not significant (p=0.39 and 0.36 respectively. The anticipatory saccades were significantly more frequent in cases than controls (p<0.0001 for both 15°/sec and 30°/sec target velocities. This was also correlated with the duration of illness. Conclusion: Anticipatory saccades are significantly more frequent during eye tracking in schizophrenia and appear to be an objective marker for the disease.

  10. Natural Eye Movement & its application for paralyzed patients

    Directory of Open Access Journals (Sweden)

    Yash Shaileshkumar Desai #

    2013-04-01

    Full Text Available The noble aim behind this project is to study and capture the Natural Eye movement detection and trying to apply it as assisting application for paralyzed patients those who cannot speak or use hands such disease as amyotrophic lateral sclerosis (ALS, Guillain-Barre Syndrome, quadriplegia & heniiparesis. Using electrophySiological genereted by the voluntary contradictions of the muscles around the eye. The proposed system which is based on the design and application of an electrooculogram (EOG based an efficient human–computer interface (HCI. Establishing an alternative channel without speaking and hand movements is important in increasing the quality of life for the handicapped. EOG-based systems are more efficient than electroencephalogram (EEG-based systems as easy acquisition, higher amplitude, and also easily classified.By using a realized virtual keyboard like graphical user interface, it is possible to notify in writing the needs of the patient in a relatively short time. Considering the bio potential measurement pitfalls, the novel EOG-based HCI system allows people to successfully communicate with their environment by using only eye movements. [1]Classifying horizontal and vertical EOG channel signals in an efficient interface is realized in this study. The nearest neighbourhood algorithm will be use to classify the signals. The novel EOG-based HCI system allows people to successfully and economically communicate with their environment by using onlyeye movements. [2]An Electrooculography is a method of tracking the ocular movement, based on the voltage changes that occur due to the medications on the special orientation of the eye dipole. The resulting signal has a myriad of possible applications. [2] In this dissertation phase one, the goal was to study the Eye movements and respective signal generation, EOG signal acquisition and also study of a Man-Machine Interface that made use of this signal. As per our goal we studied eye movements and design simple EOG acquisition circuit. We got efficient signal output in oscilloscope. I sure that result up to present stage will definitely leads us towards designing of novel assisting device for paralyzed patients. Thus, we set out to create an interface will be use by mobility impaired patients, allowing them to use their eyes to call nurse or attended person and some other requests

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

    International Nuclear Information System (INIS)

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

  12. Oxidative stress and its downstream signaling in aging eyes

    Directory of Open Access Journals (Sweden)

    Pinazo-Durán MD

    2014-04-01

    Full Text Available María Dolores Pinazo-Durán,1,* Roberto Gallego-Pinazo,2,* Jose Javier García-Medina,1,3,* Vicente Zanón-Moreno,1,4 Carlo Nucci,5 Rosa Dolz-Marco,2 Sebastián Martínez-Castillo,2 Carmen Galbis-Estrada,1 Carla Marco-Ramírez,1 Maria Isabel López-Gálvez,6,* David J Galarreta,6,* Manuel Díaz-Llópis4,*1Ophthalmic Research Unit "Santiago Grisolía", Valencia, Spain; 2Department of Ophthalmology, Macula Section, The University and Polytechnic Hospital La Fe, Valencia, Spain; 3Department of Ophthalmology, University Hospital Reina Sofia, Murcia, Spain; 4Faculty of Medicine, University of Valencia, Spain; 5University of Rome Tor Vergata, Rome, Italy; 6Instituto de Oftalmobiología Aplicada (IOBA, Valladolid, Spain *Members of the Spanish Net of Ocular Pathology of the Instituto de Salud Carlos III (Madrid, OFTAREDBackground: Oxidative stress (OS and its biomarkers are the biochemical end point of the imbalance between reactive oxygen species (ROS production and the ability of the antioxidant (AOX biological systems to fight against oxidative injury.Objective: We reviewed the role of OS and its downstream signaling in aging eyes.Methods: A search of the literature and current knowledge on the physiological and pathological mechanisms of OS were revisited in relation to the eyes and the aging process. Most prevalent ocular diseases have been analyzed herein in relation to OS and nutraceutic supplements, such as dry-eye disorders, glaucoma, age-related macular degeneration, and diabetic retinopathy.Results: Clinical, biochemical, and molecular data from anterior and posterior eye segment diseases point to OS as the common pathogenic mechanism in the majority of these ocular disorders, many of which are pathologies causing visual impairment, blindness, and subsequent loss of life quality. Studies with nutraceutic supplements in aging eye-related pathologies have also been reviewed.Conclusion: OS, nutritional status, and nutraceutic supplements have to be considered within the standards of care of older ophthalmologic patients. OS biomarkers and surrogate end points may help in managing the aging population with ocular diseases.Keywords: oxidative stress, eyes, aging, ophthalmic diseases, antioxidants, epidemiology

  13. Augmenting Customer Journey Maps with quantitative empirical data: a case on EEG and eye tracking

    OpenAIRE

    Alves, Rui; Lim, Veranika; Niforatos, Evangelos; Chen, Monchu; Karapanos, Evangelos; Nunes, Nuno Jardim

    2012-01-01

    This paper introduces the use of electroencephalography (EEG) and eye tracking in exploring customer experiences in service design. These tools are expected to allow designers to generate customer journeys from empirical data leading to new visualization methods and therefore improvements in service design deliverables.

  14. Novel automatic eye detection and tracking algorithm

    Science.gov (United States)

    Ghazali, Kamarul Hawari; Jadin, Mohd Shawal; Jie, Ma; Xiao, Rui

    2015-04-01

    The eye is not only one of the most complex but also the most important sensory organ of the human body. Eye detection and eye tracking are basement and hot issue in image processing. A non-invasive eye location and eye tracking is promising for hands-off gaze-based human-computer interface, fatigue detection, instrument control by paraplegic patients and so on. For this purpose, an innovation work frame is proposed to detect and tracking eye in video sequence in this paper. The contributions of this work can be divided into two parts. The first contribution is that eye filters were trained which can detect eye location efficiently and accurately without constraints on the background and skin colour. The second contribution is that a framework of tracker based on sparse representation and LK optic tracker were built which can track eye without constraint on eye status. The experimental results demonstrate the accuracy aspects and the real-time applicability of the proposed approach.

  15. Functional analysis and treatment of eye poking.

    Science.gov (United States)

    Kennedy, C H; Souza, G

    1995-01-01

    In four studies we analyzed the eye poking of a youth with profound disabilities. In Study 1, a functional analysis showed that eye poking occurred during the no-attention condition, but not during demand, attention or recreation conditions. The analysis did not identify socially mediated variables involved in the maintenance of eye poking; rather, eye poking may have been maintained by consequences produced directly by the response. In Study 2 we had the student wear goggles to prevent potential reinforcement from finger-eye contact. The results of Study 2 indicated that eye-poking attempts were reduced when the student wore goggles. We then tested in Study 3 the effects of two alternative topographies of stimulation. Study 3 demonstrated that eye poking was reduced when a video game was provided as a competing source of visual stimulation, and that music was less effective in reducing eye poking. In Study 4, a contingency analysis using the video game was conducted in an attempt to (a) reduce the frequency of eye poking and (b) study whether the video game functioned as a reinforcer. The results of Study 4 demonstrated substantive reductions in the frequency of eye poking, and suggested that the video game served as a reinforcer. PMID:7706147

  16. Healthy Eyes in Schools: An Evaluation of a School and Community-Based Intervention to Promote Eye Health in Rural Timor-Leste

    Science.gov (United States)

    Hobday, Karen; Ramke, Jacqueline; du Toit, Rènée; Pereira, Sara M.

    2015-01-01

    Objective: To assess whether there was an improvement in the knowledge, attitudes and practices of students after the Healthy Eyes in Schools Project intervention and to complete a process evaluation to inform future implementation of health promotion interventions. Design: A descriptive, mixed-methods design was used, including questionnaires and…

  17. Dynamic Pointing Triggers Shifts of Visual Attention in Young Infants

    Science.gov (United States)

    Rohlfing, Katharina J.; Longo, Matthew R.; Bertenthal, Bennett I.

    2012-01-01

    Pointing, like eye gaze, is a deictic gesture that can be used to orient the attention of another person towards an object or an event. Previous research suggests that infants first begin to follow a pointing gesture between 10 and 13 months of age. We investigated whether sensitivity to pointing could be seen at younger ages employing a technique…

  18. Design support at the front end of the New Service Development (NSD) process :the role of touch-points and service personality in supporting team work and innovation processes

    OpenAIRE

    Clatworthy, Simon

    2013-01-01

    This thesis explores the first stages of New Service Development, and focuses upon the role that design can play to improve the innovation performance of a development team. The work took a ”research by design” approach, that resulted in the design and evaluation of tools and process support, for two specific areas of service innovation. Firstly, how working with the touch-points of a service can improve innovation performance, and secondly the importance of aligning the customer experien...

  19. Pattern of blood vessels in eyes with coloboma

    Directory of Open Access Journals (Sweden)

    Gopal Lingam

    2013-01-01

    Full Text Available Background: Choroidal coloboma, especially with optic disc involvement affects the blood vessel (BV pattern in the fundus. Aim: The aim of this study was to report the observations on the pattern of retinal BVs in eyes with fundus coloboma. Design: Retrospective observational study. Materials and Methods: Twenty four eyes of 19 patients with fundus coloboma and the disc involvement in the coloboma was classified according to a previous publication. Results: Four varieties of BVs were identified in the area of coloboma - BVs that were continuous with those arising from the optic disc; vessels emanating from the floor of coloboma whose continuity with central retinal artery or its branches could be indirectly established; and those emanating from the floor of coloboma whose continuity with central retinal artery could not be established. In addition, extraocular BVs were visible through the thinned sclera. The retinal BVs often traversed the coloboma to reach the normal retina. The disc itself was found to be small and had no physiological cup (if not colobomatous. Conclusions: One should be aware of the major BVs transgressing the coloboma while performing relaxing cuts in the intercalary membrane, during the surgery for retinal detachments in eyes with coloboma. Physiological cup is usually absent (when the disc is not colobomatous. Hence, any cupping in such eyes should be viewed with suspicion.

  20. Drawing from Memory: Hand-Eye Coordination at Multiple Scales

    Science.gov (United States)

    Spivey, Michael J.

    2013-01-01

    Eyes move to gather visual information for the purpose of guiding behavior. This guidance takes the form of perceptual-motor interactions on short timescales for behaviors like locomotion and hand-eye coordination. More complex behaviors require perceptual-motor interactions on longer timescales mediated by memory, such as navigation, or designing and building artifacts. In the present study, the task of sketching images of natural scenes from memory was used to examine and compare perceptual-motor interactions on shorter and longer timescales. Eye and pen trajectories were found to be coordinated in time on shorter timescales during drawing, and also on longer timescales spanning study and drawing periods. The latter type of coordination was found by developing a purely spatial analysis that yielded measures of similarity between images, eye trajectories, and pen trajectories. These results challenge the notion that coordination only unfolds on short timescales. Rather, the task of drawing from memory evokes perceptual-motor encodings of visual images that preserve coarse-grained spatial information over relatively long timescales as well. PMID:23554894