WorldWideScience

Sample records for wide k-band imaging

  1. Preliminary Results on VLT K-band Imaging Observations of GRB ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Abstract. We have obtained K-band imaging observations of Gamma-. Ray Burst (GRB) host galaxies with the near-infrared spectro-imager. ISAAC installed on the Very Large Telescope at Paranal (Chile). The derived K magnitudes, combined with other photometric data taken from the literature, are used to investigate the ...

  2. The USNO-UKIRT K-band Hemisphere Survey

    Science.gov (United States)

    Dahm, Scott; Bruursema, Justice; Munn, Jeffrey A.; Vrba, Fred J.; Dorland, Bryan; Dye, Simon; Kerr, Tom; Varricatt, Watson; Irwin, Mike; Lawrence, Andy; McLaren, Robert; Hodapp, Klaus; Hasinger, Guenther

    2018-01-01

    We present initial results from the United States Naval Observatory (USNO) and UKIRT K-band Hemisphere Survey (U2HS), currently underway using the Wide Field Camera (WFCAM) installed on UKIRT on Maunakea. U2HS is a collaborative effort undertaken by USNO, the Institute for Astronomy, University of Hawaii, the Cambridge Astronomy Survey Unit (CASU) and the Wide Field Astronomy Unit (WFAU) in Edinburgh. The principal objective of the U2HS is to provide continuous northern hemisphere K-band coverage over a declination range of δ=0o – +60o by combining over 12,700 deg2 of new imaging with the existing UKIRT Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS), Galactic Plane Survey (GPS) and Galactic Cluster Survey (GCS). U2HS will achieve a 5-σ point source sensitivity of K~18.4 mag (Vega), over three magnitudes deeper than the Two Micron All Sky Survey (2MASS). In this contribution we discuss survey design, execution, data acquisition and processing, photometric calibration and quality control. The data obtained by the U2HS will be made publicly available through the Wide Field Science Archive (WSA) maintained by the WFAU.

  3. K-Band Traveling-Wave Tube Amplifier

    Science.gov (United States)

    Force, Dale A.; Simons, Rainee N.; Peterson, Todd T.; Spitsen, Paul C.

    2010-01-01

    A new space-qualified, high-power, high-efficiency, K-band traveling-wave tube amplifier (TWTA) will provide high-rate, high-capacity, direct-to-Earth communications for science data and video gathered by the Lunar Reconnaissance Orbiter (LRO) during its mission. Several technological advances were responsible for the successful demonstration of the K-band TWTA.

  4. Wide Field Imager for Athena

    Science.gov (United States)

    Meidinger, Norbert; Nandra, Kirpal; Rau, Arne; Plattner, Markus; WFI proto-Consortium

    2015-09-01

    The Wide Field Imager focal plane instrument on ATHENA will combine unprecedented survey power through its large field of view of 40 arcmin with a high count-rate capability (> 1 Crab). The energy resolution of the silicon sensor is state-of-the-art in the energy band of interest from 0.1 keV to 15 keV. At energy of 6 keV for example, the full width at half maximum of the line shall be not worse than 150 eV until the end of the mission. The performance is accomplished by a set of DEPFET active pixel sensor matrices with a pixel size well suited to the angular resolution of 5 arc sec (on-axis) of the mirror system.Each DEPFET pixel is a combined detector-amplifier structure with a MOSFET integrated onto a fully depleted 450 micron thick silicon bulk. Two different types of DEPFET sensors are planned for the WFI instrument: A set of large-area sensors to cover the physical size of 14 cm x 14 cm in the focal plane and a single gateable DEPFET sensor matrix optimized for the high count rate capability of the instrument. An overview will be given about the presently developed instrument concept and design, the status of the technology development, and the expected performance. An outline of the project organization, the model philosophy as well as the schedule will complete the presentation about the Wide Field Imager for Athena.

  5. Wide-Field Imaging Using Nitrogen Vacancies

    Science.gov (United States)

    Englund, Dirk Robert (Inventor); Trusheim, Matthew Edwin (Inventor)

    2017-01-01

    Nitrogen vacancies in bulk diamonds and nanodiamonds can be used to sense temperature, pressure, electromagnetic fields, and pH. Unfortunately, conventional sensing techniques use gated detection and confocal imaging, limiting the measurement sensitivity and precluding wide-field imaging. Conversely, the present sensing techniques do not require gated detection or confocal imaging and can therefore be used to image temperature, pressure, electromagnetic fields, and pH over wide fields of view. In some cases, wide-field imaging supports spatial localization of the NVs to precisions at or below the diffraction limit. Moreover, the measurement range can extend over extremely wide dynamic range at very high sensitivity.

  6. SHARK-NIR: from K-band to a key instrument, a status update

    Science.gov (United States)

    Farinato, Jacopo; Bacciotti, Francesca; Baffa, Carlo; Baruffolo, Andrea; Bergomi, Maria; Bongiorno, Angela; Carbonaro, Luca; Carolo, Elena; Carlotti, Alexis; Centrone, Mauro; Close, Laird; De Pascale, Marco; Dima, Marco; D'Orazi, Valentina; Esposito, Simone; Fantinel, Daniela; Farisato, Giancarlo; Gaessler, Wolfgang; Giallongo, Emanuele; Greggio, Davide; Guyon, Olivier; Hinz, Philip; Lisi, Franco; Magrin, Demetrio; Marafatto, Luca; Mohr, Lars; Montoya, Manny; Pedichini, Fernando; Pinna, Enrico; Puglisi, Alfio; Ragazzoni, Roberto; Salasnich, Bernardo; Stangalini, Marco; Vassallo, Daniele; Verinaud, Christophe; Viotto, Valentina

    2016-07-01

    SHARK-NIR channel is one of the two coronagraphic instruments proposed for the Large Binocular Telescope, in the framework of the call for second generation instruments, issued in 2014. Together with the SHARK-VIS channel, it will offer a few observing modes (direct imaging, coronagraphic imaging and coronagraphic low resolution spectroscopy) covering a wide wavelength domain, going from 0.5μm to 1.7μm. Initially proposed as an instrument covering also the K-band, the current design foresees a camera working from Y to H bands, exploiting in this way the synergy with other LBT instruments such as LBTI, which is actually covering wavelengths greater than L' band, and it will be soon upgraded to work also in K band. SHARK-NIR has been undergoing the conceptual design review at the end of 2015 and it has been approved to proceed to the final design phase, receiving the green light for successive construction and installation at LBT. The current design is significantly more flexible than the previous one, having an additional intermediate pupil plane that will allow the usage of coronagraphic techniques very efficient in term of contrast and vicinity to the star, increasing the instrument coronagraphic performance. The latter is necessary to properly exploit the search of giant exo-planets, which is the main science case and the driver for the technical choices of SHARK-NIR. We also emphasize that the LBT AO SOUL upgrade will further improve the AO performance, making possible to extend the exo-planet search to target fainter than normally achieved by other 8-m class telescopes, and opening in this way to other very interesting scientific scenarios, such as the characterization of AGN and Quasars (normally too faint to be observed) and increasing considerably the sample of disks and jets to be studied. Finally, we emphasize that SHARK-NIR will offer XAO direct imaging capability on a FoV of about 15"x15", and a simple coronagraphic spectroscopic mode offering spectral

  7. IOT Overview: Wide-Field Imaging

    Science.gov (United States)

    Selman, F. J.

    The Wide Field Imager (WFI) instrument at La Silla has been the workhorse of wide-field imaging instruments at ESO for several years. In this contribution I will summarize the issues relating to its productivity for the community both in terms of the quality and quantity of data that has come out of it. Although only surveys of limited scope have been completed using WFI, it is ESO's stepping-stone to the new generation of survey telescopes.

  8. Clustering of K-band selected local galaxies

    OpenAIRE

    Ma, Bin; Meng, Kelai; Pan, Jun; Huang, Jiasheng; Feng, Longlong

    2009-01-01

    We present detailed clustering analysis of a large K-band selected local galaxy sample, which is constructed from the 2MASS and the SDSS and consists of $82,486$ galaxies with $10 < K < 13.5$ and $0.01 < z < 0.1$. The two-point correlation function of the magnitude-limited sample in real space at small scales is well described by a power law $\\xi(r)=(r/6.44\\pm0.23)^{-1.81\\pm0.02}$. The pairwise velocity dispersion is derived from the anisotropic two-point correlation function and find the dis...

  9. Wide field imaging problems in radio astronomy

    Science.gov (United States)

    Cornwell, T. J.; Golap, K.; Bhatnagar, S.

    2005-03-01

    The new generation of synthesis radio telescopes now being proposed, designed, and constructed face substantial problems in making images over wide fields of view. Such observations are required either to achieve the full sensitivity limit in crowded fields or for surveys. The Square Kilometre Array (SKA Consortium, Tech. Rep., 2004), now being developed by an international consortium of 15 countries, will require advances well beyond the current state of the art. We review the theory of synthesis radio telescopes for large fields of view. We describe a new algorithm, W projection, for correcting the non-coplanar baselines aberration. This algorithm has improved performance over those previously used (typically an order of magnitude in speed). Despite the advent of W projection, the computing hardware required for SKA wide field imaging is estimated to cost up to $500M (2015 dollars). This is about half the target cost of the SKA. Reconfigurable computing is one way in which the costs can be decreased dramatically.

  10. The Wide Field Imager for Athena

    Science.gov (United States)

    Rau, A.; Nandra, K.; Meidinger, N.; Plattner, M.

    2017-10-01

    The Wide Field Imager (WFI) is one of the two scientific instruments of Athena, ESA's next large X-ray Observatory with launch in 2028. The instrument will provide two defining capabilities to the mission sensitive wide-field imaging spectroscopy and excellent high-count rate performance. It will do so with the use of two separate detectors systems, the Large Detector Array (LDA) optimized for its field of view (40'×40') with a 100 fold survey speed increase compared to existing X-ray missions, and the Fast Detector (FD) tweaked for high throughput and low pile-up for point sources as bright as the Crab. In my talk I will present the key performance parameters of the instrument and their links to the scientific goals of Athena and summarize the status of the ongoing development activities.

  11. Athena Wide Field Imager key science drivers

    Science.gov (United States)

    Rau, Arne; Nandra, Kirpal; Aird, James; Comastri, Andrea; Dauser, Thomas; Merloni, Andrea; Pratt, Gabriel W.; Reiprich, Thomas H.; Fabian, Andy C.; Georgakakis, Antonis; Güdel, Manuel; RóŻańska, Agata; Sanders, Jeremy S.; Sasaki, Manami; Vaughan, Simon; Wilms, Jörn; Meidinger, Norbert

    2016-07-01

    The Wide Field Imager (WFI) is one of two instruments for the Advanced Telescope for High-ENergy Astrophysics (Athena). In this paper we summarise three of the many key science objectives for the WFI { the formation and growth of supermassive black holes, non-gravitational heating in clusters of galaxies, and spin measurements of stellar mass black holes { and describe their translation into the science requirements and ultimately instrument requirements. The WFI will be designed to provide excellent point source sensitivity and grasp for performing wide area surveys, surface brightness sensitivity, survey power, and absolute temperature and density calibration for in-depth studies of the outskirts of nearby clusters of galaxies and very good high-count rate capability, throughput, and low pile-up, paired with very good spectral resolution, for detailed explorations of bright Galactic compact objects.

  12. The Wide Field Imager Instrument for Athena

    OpenAIRE

    Meidinger, Norbert; Eder, Josef; Eraerds, Tanja; Nandra, Kirpal; Pietschner, Daniel; Plattner, Markus; Rau, Arne; Strecker, Rafael

    2017-01-01

    The WFI (Wide Field Imager) instrument is planned to be one of two complementary focal plane cameras on ESA's next X-ray observatory Athena. It combines unprecedented survey power through its large field of view of 40 amin x 40 amin together with excellent count rate capability (larger than 1 Crab). The energy resolution of the silicon sensor is state-of-the-art in the energy band of interest from 0.2 keV to 15 keV, e.g. the full width at half maximum of a line at 7 keV will be better than 17...

  13. K-band spectroscopic metallicities and temperatures of M-dwarf stars

    Directory of Open Access Journals (Sweden)

    Rojas-Ayala Bárbara

    2013-04-01

    Full Text Available I present the metallicity and effective temperature techniques developed for M dwarf stars by Rojas-Ayala et al. (2010, 2012. These techniques are based on absorption features present in the modest resolution K-band spectra (R∼2700 of M dwarfs and have been calibrated using FGK+M dwarf pairs and synthetic atmosphere models. The H2O-K2 index seems to overestimate the effective temperatures of M dwarfs when compared to interferometric measurements. The metallicity distribution of the M dwarf host candidates by the Kepler Mission hints that jovian-size planets form preferentially around solar and super-solar metallicity environments, while small rocky planet host exhibit a wide range of metallicities, just like in their solar-type counterparts.

  14. The Wide Field Imager instrument for Athena

    Science.gov (United States)

    Meidinger, Norbert; Barbera, Marco; Emberger, Valentin; Fürmetz, Maria; Manhart, Markus; Müller-Seidlitz, Johannes; Nandra, Kirpal; Plattner, Markus; Rau, Arne; Treberspurg, Wolfgang

    2017-08-01

    ESA's next large X-ray mission ATHENA is designed to address the Cosmic Vision science theme 'The Hot and Energetic Universe'. It will provide answers to the two key astrophysical questions how does ordinary matter assemble into the large-scale structures we see today and how do black holes grow and shape the Universe. The ATHENA spacecraft will be equipped with two focal plane cameras, a Wide Field Imager (WFI) and an X-ray Integral Field Unit (X-IFU). The WFI instrument is optimized for state-of-the-art resolution spectroscopy over a large field of view of 40 amin x 40 amin and high count rates up to and beyond 1 Crab source intensity. The cryogenic X-IFU camera is designed for high-spectral resolution imaging. Both cameras share alternately a mirror system based on silicon pore optics with a focal length of 12 m and large effective area of about 2 m2 at an energy of 1 keV. Although the mission is still in phase A, i.e. studying the feasibility and developing the necessary technology, the definition and development of the instrumentation made already significant progress. The herein described WFI focal plane camera covers the energy band from 0.2 keV to 15 keV with 450 μm thick fully depleted back-illuminated silicon active pixel sensors of DEPFET type. The spatial resolution will be provided by one million pixels, each with a size of 130 μm x 130 μm. The time resolution requirement for the WFI large detector array is 5 ms and for the WFI fast detector 80 μs. The large effective area of the mirror system will be completed by a high quantum efficiency above 90% for medium and higher energies. The status of the various WFI subsystems to achieve this performance will be described and recent changes will be explained here.

  15. Lunar Reconnaissance Orbiter K-Band (26 GHz) Signal Analysis: Initial Study Results

    Science.gov (United States)

    Morabito, D. D.; Heckman, D.

    2017-11-01

    Lower frequency telemetry bands are becoming more limited in bandwidth due to increased competition between flight projects and other entities. Higher frequency bands offer significantly more bandwidth and hence the prospect of much higher data rates. Future or prospective flight projects considering higher frequency bands such as Ka-band (32 GHz) for deep-space and K-band (26 GHz) for near-Earth telemetry links are interested in past flight experience with available received data at these frequencies. Given that there is increased degradation due to the atmosphere at these higher frequencies, there is an effort to retrieve flight data of received signal strength to analyze performance under a variety of factors. Such factors include elevation angle, season, and atmospheric conditions. This article reports on the analysis findings of over 10 million observations of received signal strength of the Lunar Reconnaissance Orbiter (LRO) spacecraft collected between 2014 and 2017. We analyzed these data to characterize link performance over a wide range of weather conditions, season, and as a function of elevation angle. Based on this analysis, we have confirmed the safety of using a 3-dB margin for preflight planning purposes. These results suggest that a 3-dB margin with respect to adverse conditions will ensure a 98 to 99 percent data return under 95 percent weather conditions at 26 GHz (K-band), thus confirming expectations from link budget predictions. The results suggest that this margin should be applicable for all elevation angles above 10 deg. Thus, missions that have sufficient power for their desired data rates may opt to use 10 deg as their minimum elevation angle. Limitations of this study include climate variability and the fact that the observations require removal of hotbody noise in order to perform an adequate cumulative distribution function (CDF) analysis, which is planned for a future comprehensive study. Flight projects may use other link margins

  16. The wide field imager instrument for Athena

    Science.gov (United States)

    Meidinger, Norbert; Nandra, Kirpal; Plattner, Markus; Porro, Matteo; Rau, Arne; Santangelo, Andrea E.; Tenzer, Chris; Wilms, Jörn

    2014-07-01

    The "Hot and Energetic Universe" has been selected as the science theme for ESA's L2 mission, scheduled for launch in 2028. The proposed Athena X-ray observatory provides the necessary capabilities to achieve the ambitious goals of the science theme. The X-ray mirrors are based on silicon pore optics technology and will have a 12 m focal length. Two complementary camera systems are foreseen which can be moved in and out of the focal plane by an interchange mechanism. These instruments are the actively shielded micro-calorimeter spectrometer X-IFU and the Wide Field Imager (WFI). The WFI will combine an unprecedented survey power through its large field of view of 40 arcmin with a high countrate capability (approx. 1 Crab). It permits a state-of-the-art energy resolution in the energy band of 0.1 keV to 15 keV during the entire mission lifetime (e.g. FWHM serial analog output. The architecture of sensor and readout ASIC allows readout in full frame mode and window mode as well by addressing selectively arbitrary sub-areas of the sensor allowing time resolution in the order of 10 μs. The further detector electronics has mainly the following tasks: digitization, pre-processing and telemetry of event data as well as supply and control of the detector system. Although the sensor will already be equipped with an on-chip light blocking filter, a filter wheel is necessary to provide an additional external filter, an on-board calibration source, an open position for outgassing, and a closed position for protection of the sensor. The sensor concept provides high quantum efficiency over the entire energy band and we intend to keep the instrumental background as low as possible by designing a graded Z-shield around the sensor. All these properties make the WFI a very powerful survey instrument, significantly surpassing currently existing observatories and in addition allow high-time resolution of the brightest X-ray sources with low pile-up and high efficiency. This

  17. Ku and K band GaN High Power Amplifier MMICs

    Science.gov (United States)

    2017-03-20

    Ku- and K -band GaN High Power Amplifier MMICs Val Kaper, Scott Harris, Keith Kessler Raytheon, Andover MA 01810 vkaper@raytheon.com Abstract: This...paper describes development and characteri- zation of three Ku- and K -band GaN High Power Amplifier (HPA) MMICs. The circuits are implemented in...delivers 25 Watts of output power with 45% PAE. A K -band HPA operates from 19.5 to 22 GHz and delivers 18 Watts of output power with 29% PAE

  18. The wide field imager instrument for Athena

    Science.gov (United States)

    Meidinger, Norbert; Eder, Josef; Eraerds, Tanja; Nandra, Kirpal; Pietschner, Daniel; Plattner, Markus; Rau, Arne; Strecker, Rafael

    2016-07-01

    The WFI (Wide Field Imager) instrument is planned to be one of two complementary focal plane cameras on ESA's next X-ray observatory Athena. It combines unprecedented survey power through its large field of view of 40 amin x 40 amin together with excellent count rate capability (>= 1 Crab). The energy resolution of the silicon sensor is state-of-the-art in the energy band of interest from 0.2 keV to 15 keV, e.g. the full width at half maximum of a line at 7 keV will be MOSFET integrated onto a fully depleted 450 μm thick silicon bulk. Two detectors are planned for the WFI instrument: A large-area detector comprising four sensors with a total of 1024 x 1024 pixels and a fast detector optimized for high count rate observations. This high count rate capable detector permits for bright point sources with an intensity of 1 Crab a throughput of more than 80% and a pile-up of less than 1%. The fast readout of the DEPFET pixel matrices is facilitated by an ASIC development, called VERITAS-2. Together with the Switcher-A, a control ASIC that allows for operation of the DEPFET in rolling shutter mode, these elements form the key components of the WFI detectors. The detectors are surrounded by a graded-Z shield, which has in particular the purpose to avoid fluorescence lines that would contribute to the instrument background. Together with ultra-thin coating of the sensor and particle identification by the detector itself, the particle induced background shall be minimized in order to achieve the scientific requirement of a total instrumental background value smaller than 5 x 10-3 cts/cm2/s/keV. Each detector has its dedicated detector electronics (DE) for supply and data acquisition. Due to the high frame rate in combination with the large pixel array, signal correction and event filtering have to be done on-board and in real-time as the raw data rate would by far exceed the feasible telemetry rate. The data streams are merged and compressed in the Instrument Control and

  19. Wide-Field, Deep UV Raman Hyperspectral Imager Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ChemImage Sensor Systems (CISS), teaming with the University of South Carolina, proposes a revolutionary wide-field Raman hyperspectral imaging system capable of...

  20. A monolithic K-band phase-locked loop for microwave radar application

    Science.gov (United States)

    Zhou, Guangyao; Ma, Shunli; Li, Ning; Ye, Fan; Ren, Junyan

    2017-02-01

    A monolithic K-band phase-locked loop (PLL) for microwave radar application is proposed and implemented in this paper. By eliminating the tail transistor and using optimized high-Q LC-tank, the proposed voltage-controlled oscillator (VCO) achieves a tuning range of 18.4 to 23.3 GHz and reduced phase noise. Two cascaded current-mode logic (CML) divide-by-two frequency prescalers are implemented to bridge the frequency gap, in which inductor peaking technique is used in the first stage to further boost allowable input frequency. Six-stage TSPC divider chain is used to provide programmable division ratio from 64 to 127, and a second-order passive loop filter with 825 kHz bandwidth is also integrated on-chip to minimize required external components. The proposed PLL needs only approximately 18.2 μs settling time, and achieves a wide tuning range from 18.4 to 23.3 GHz, with a typical output power of -0.84 dBm and phase noise of -91.92 dBc/Hz @ 1 MHz. The chip is implemented in TSMC 65 nm CMOS process, and occupies an area of 0.56 mm2 without pads under a 1.2 V single voltage supply. Project supported by the National High-Tech Research and Development Program of China (No. 2013AA014101).

  1. Ultra-wide-field imaging in diabetic retinopathy.

    Science.gov (United States)

    Ghasemi Falavarjani, Khalil; Tsui, Irena; Sadda, Srinivas R

    2017-10-01

    Since 1991, 7-field images captured with 30-50 degree cameras in the Early Treatment Diabetic Retinopathy Study were the gold standard for fundus imaging to study diabetic retinopathy. Ultra-wide-field images cover significantly more area (up to 82%) of the fundus and with ocular steering can in many cases image 100% of the fundus ("panretinal"). Recent advances in image analysis of ultra-wide-field imaging allow for precise measurements of the peripheral retinal lesions. There is a growing consensus in the literature that ultra-wide-field imaging improves detection of peripheral lesions in diabetic retinopathy and leads to more accurate classification of the disease. There is discordance among studies, however, on the correlation between peripheral diabetic lesions and diabetic macular edema and optimal management strategies to treat diabetic retinopathy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Study of dental enamel and synthetic hydroxyapatite irradiated by EPR at K-band

    Energy Technology Data Exchange (ETDEWEB)

    Santos, A.B. [Departamento Fisica e Matematica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto, SP (Brazil); Universidade Federal do Tocantins, 77020-120 Palmas, Tocantins (Brazil)]. E-mail: adevailton@uft.edu.br; Rossi, A.M. [Centro Brasileiro de Pesquisas Fisicas, 22290 180 Rio de Janeiro, RJ (Brazil); Baffa, O. [Departamento Fisica e Matematica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto, SP (Brazil)

    2005-02-01

    In this preliminary work the EPR spectra of a small dental enamel block and a synthetic B-type hydroxyapatite in powder form, both irradiated with gamma rays, were analyzed in K-band. The spectra of the dental enamel block allow the analysis of independent components with different angular orientations, while the study of the dosimetric properties of the synthetic hydroxyapatites showed good performance of this spectrometer. K-band spectra show better resolution when compared to X-band, while using significantly less sample material.

  3. Study of dental enamel and synthetic hydroxyapatite irradiated by EPR at K-band.

    Science.gov (United States)

    Santos, A B; Rossi, A M; Baffa, O

    2005-02-01

    In this preliminary work the EPR spectra of a small dental enamel block and a synthetic B-type hydroxyapatite in powder form, both irradiated with gamma rays, were analyzed in K-band. The spectra of the dental enamel block allow the analysis of independent components with different angular orientations, while the study of the dosimetric properties of the synthetic hydroxyapatites showed good performance of this spectrometer. K-band spectra show better resolution when compared to X-band, while using significantly less sample material.

  4. Wide-angle fundus imaging through the Boston keratoprosthesis.

    Science.gov (United States)

    Sayegh, Rony R; Dohlman, Claes H

    2013-06-01

    To explore the feasibility and compare the outcomes of three wide-angle fundus cameras for imaging the peripheral retina through the Type 1 Boston keratoprosthesis. The noncontact Optos and the contact RetCam and Panoret wide-angle imaging systems were used to image the retina of eyes implanted with a keratoprosthesis. The failure-to-image rate, ease of acquisition, and quality of the images were noted, and the field of view was compared. Limitations and complications were recorded. Optos was then performed on patients referred for ultrasound B-scan evaluation, and the imaging findings were correlated. Retinal images with all three cameras were obtained on four eyes. Optos could be performed on all four eyes, RetCam on three, and Panoret on two. The field of view was comparable between the three different cameras. The best quality images were obtained with Optos. The external illumination of the Panoret made it impossible to image the only darkly pigmented individual in the series. Both contact devices failed to image another patient who was too agitated. Two patients had some ocular irritation from the coupling agent that resolved with replacement of the contact lens. Optos images were obtained on an additional six eyes, and findings correlated well with those on B-scan. Optos was superior to B-scan in an eye with silicone oil filling. Wide-angle fundus imaging through the keratoprosthesis is possible, and all three cameras performed similarly. The good quality of pictures obtained with the noncontact Optos, as well as its ease of use, comfort, and safety make it a preferred choice. Optos complements B-scan in the examination of the peripheral retina through the keratoprosthesis, and it may even be superior in certain settings.

  5. Image and video search engine for the World Wide Web

    Science.gov (United States)

    Smith, John R.; Chang, Shih-Fu

    1997-01-01

    We describe a visual information system prototype for searching for images and videos on the World-Wide Web. New visual information in the form of images, graphics, animations and videos is being published on the Web at an incredible rate. However, cataloging this visual data is beyond the capabilities of current text-based Web search engines. In this paper, we describe a complete system by which visual information on the Web is (1) collected by automated agents, (2) processed in both text and visual feature domains, (3) catalogued and (4) indexed for fast search and retrieval. We introduce an image and video search engine which utilizes both text-based navigation and content-based technology for searching visually through the catalogued images and videos. Finally, we provide an initial evaluation based upon the cataloging of over one half million images and videos collected from the Web.

  6. Two wide-angle imaging neutral-atom spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    McComas, D.J.

    1997-12-31

    The Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS) mission provides a new capability for stereoscopically imaging the magnetosphere. By imaging the charge exchange neutral atoms over a broad energy range (1 < E , {approximately} 100 keV) using two identical instruments on two widely-spaced high-altitude, high-inclination spacecraft, TWINS will enable the 3-dimensional visualization and the resolution of large scale structures and dynamics within the magnetosphere for the first time. These observations will provide a leap ahead in the understanding of the global aspects of the terrestrial magnetosphere and directly address a number of critical issues in the ``Sun-Earth Connections`` science theme of the NASA Office of Space Science.

  7. Retrospective biodosimetry with small tooth enamel samples using K-Band and X-Band

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, Jorge A. [Departamento de Fisica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto, Sao Paulo (Brazil); Kinoshita, Angela [Departamento de Fisica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto, Sao Paulo (Brazil); Universidade Sagrado Coracao - USC, 17011-160 Bauru, Sao Paulo (Brazil); Leonor, Sergio J. [Departamento de Fisica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto, Sao Paulo (Brazil); Belmonte, Gustavo C. [Universidade Sagrado Coracao - USC, 17011-160 Bauru, Sao Paulo (Brazil); Baffa, Oswaldo, E-mail: baffa@usp.br [Departamento de Fisica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto, Sao Paulo (Brazil)

    2011-09-15

    In an attempt to make the in vitro electron spin resonance (ESR) retrospective dosimetry of the tooth enamel a lesser invasive method, experiments using X-Band and K-Band were performed, aiming to determine conditions that could be used in cases of accidental exposures. First, a small prism from the enamel was removed and ground with an agate mortar and pestle until particles reach a diameter of approximately less than 0.5 mm. This enamel extraction process resulted in lower signal artifact compared with the direct enamel extraction performed with a diamond burr abrasion. The manual grinding of the enamel does not lead to any induced ESR signal artifact, whereas the use of a diamond burr at low speed produces a signal artifact equivalent to the dosimetric signal induced by a dose of 500 mGy of gamma irradiation. A mass of 25 mg of enamel was removed from a sound molar tooth previously irradiated in vitro with a dose of 100 mGy. This amount of enamel was enough to detect the dosimetric signal in a standard X-Band spectrometer. However using a K-Band spectrometer, samples mass between 5 and 10 mg were sufficient to obtain the same sensitivity. An overall evaluation of the uncertainties involved in the process in this and other dosimetric assessments performed at our laboratory indicates that it is possible at K-Band to estimate a 100 mGy dose with 25% accuracy. In addition, the use of K-Band also presented higher sensitivity and allowed the use of smaller sample mass in comparison with X-Band. Finally, the restoration process performed on a tooth after extraction of the 25 mg of enamel is described. This was conducted by dental treatment using photopolymerizable resin which enabled complete recovery of the tooth from the functional and aesthetic viewpoint showing that this procedure can be minimally invasive.

  8. World Wide Web Based Image Search Engine Using Text and Image Content Features

    Science.gov (United States)

    Luo, Bo; Wang, Xiaogang; Tang, Xiaoou

    2003-01-01

    Using both text and image content features, a hybrid image retrieval system for Word Wide Web is developed in this paper. We first use a text-based image meta-search engine to retrieve images from the Web based on the text information on the image host pages to provide an initial image set. Because of the high-speed and low cost nature of the text-based approach, we can easily retrieve a broad coverage of images with a high recall rate and a relatively low precision. An image content based ordering is then performed on the initial image set. All the images are clustered into different folders based on the image content features. In addition, the images can be re-ranked by the content features according to the user feedback. Such a design makes it truly practical to use both text and image content for image retrieval over the Internet. Experimental results confirm the efficiency of the system.

  9. Wide-field fundus imaging with trans-palpebral illumination

    Science.gov (United States)

    Toslak, Devrim; Thapa, Damber; Chen, Yanjun; Erol, Muhammet Kazim; Chan, R. V. Paul; Yao, Xincheng

    2017-02-01

    In conventional fundus imaging devices, transpupillary illumination is used for illuminating the inside of the eye. In this method, the illumination light is directed into the posterior segment of the eye through the cornea and passes the pupillary area. As a result of sharing the pupillary area for the illumination beam and observation path, pupil dilation is typically necessary for wide-angle fundus examination, and the field of view is inherently limited. An alternative approach is to deliver light from the sclera. It is possible to image a wider retinal area with transcleral-illumination. However, the requirement of physical contact between the illumination probe and the sclera is a drawback of this method. We report here trans-palpebral illumination as a new method to deliver the light through the upper eyelid (palpebra). For this study, we used a 1.5 mm diameter fiber with a warm white LED light source. To illuminate the inside of the eye, the fiber illuminator was placed at the location corresponding to the pars plana region. A custom designed optical system was attached to a digital camera for retinal imaging. The optical system contained a 90 diopter ophthalmic lens and a 25 diopter relay lens. The ophthalmic lens collected light coming from the posterior of the eye and formed an aerial image between the ophthalmic and relay lenses. The aerial image was captured by the camera through the relay lens. An adequate illumination level was obtained to capture wide angle fundus images within ocular safety limits, defined by the ISO 15004-2: 2007 standard. This novel trans-palpebral illumination approach enables wide-angle fundus photography without eyeball contact and pupil dilation.

  10. WFIRST: Astrometry with the Wide-Field Imager

    Science.gov (United States)

    Bellini, Andrea; WFIRST Astrometry Working Group

    2018-01-01

    The wide field of view and stable, sharp images delivered by WFIRST's Wide-Field Imager make it an excellent instrument for astrometry, one of five major discovery areas identified in the 2010 Decadal Survey. Compared to the Hubble Space Telescope, WFIRST's wider field of view with similar image quality will provide hundreds more astrometric targets per image as well as background galaxies and stars with precise positions in the Gaia catalog. In addition, WFIRST will operate in the infrared, a wavelength regime where the most precise astrometry has so far been achieved with adaptive optics images from large ground-based telescopes. WFIRST will provide at least a factor of three improvement in astrometry over the current state of the art in this wavelength range, while spanning a field of view thousands of times larger. WFIRST is thus poised to make major contributions to multiple science topics in which astrometry plays an important role, without major alterations to the planned mission or instrument. We summarize a few of the most compelling science cases where WFIRST astrometry could prove transformational.

  11. Study of Wide Swath Synthetic Aperture Ladar Imaging Techology

    Directory of Open Access Journals (Sweden)

    Zhang Keshu

    2017-02-01

    Full Text Available Combining synthetic-aperture imaging and coherent-light detection technology, the weak signal identification capacity of Synthetic Aperture Ladar (SAL reaches the photo level, and the image resolution exceeds the diffraction limit of the telescope to obtain high-resolution images irrespective to ranges. This paper introduces SAL, including the development path, technology characteristics, and the restriction of imaging swath. On the basis of this, we propose to integrate the SAL technology for extending its swath. By analyzing the scanning-operation mode and the signal model, the paper explicitly proposes that the former mode will be the developmental trend of the SAL technology. This paper also introduces the flight demonstrations of the SAL and the imaging results of remote targets, showing the potential of the SAL in long-range, high-resolution, and scanning-imaging applications. The technology and the theory of the scanning mode of SAL compensates for the defects related to the swath and operation efficiency of the current SAL. It provides scientific foundation for the SAL system applied in wide swath, high resolution earth observation, and the ISAL system applied in space-targets imaging.

  12. A World Wide Web Region-Based Image Search Engine

    DEFF Research Database (Denmark)

    Kompatsiaris, Ioannis; Triantafyllou, Evangelia; Strintzis, Michael G.

    2001-01-01

    information. These features along with additional information such as the URL location and the date of index procedure are stored in a database. The user can access and search this indexed content through the Web with an advanced and user friendly interface. The output of the system is a set of links......In this paper the development of an intelligent image content-based search engine for the World Wide Web is presented. This system will offer a new form of media representation and access of content available in WWW. Information Web Crawlers continuously traverse the Internet and collect images...

  13. WIDE-FIELD WIDE-BAND INTERFEROMETRIC IMAGING: THE WB A-PROJECTION AND HYBRID ALGORITHMS

    Energy Technology Data Exchange (ETDEWEB)

    Bhatnagar, S.; Rau, U.; Golap, K., E-mail: sbhatnag@nrao.edu, E-mail: rurvashi@nrao.edu, E-mail: kgolap@nrao.edu [National Radio Astronomy Observatory, Socorro, NM 87801 (United States)

    2013-06-20

    Variations of the antenna primary beam (PB) pattern as a function of time, frequency, and polarization form one of the dominant direction-dependent effects at most radio frequency bands. These gains may also vary from antenna to antenna. The A-Projection algorithm, published earlier, accounts for the effects of the narrow-band antenna PB in full polarization. In this paper, we present the wide-band A-Projection algorithm (WB A-Projection) to include the effects of wide bandwidth in the A-term itself and show that the resulting algorithm simultaneously corrects for the time, frequency, and polarization dependence of the PB. We discuss the combination of the WB A-Projection and the multi-term multi-frequency synthesis (MT-MFS) algorithm for simultaneous mapping of the sky brightness distribution and the spectral index distribution across a wide field of view. We also discuss the use of the narrow-band A-Projection algorithm in hybrid imaging schemes that account for the frequency dependence of the PB in the image domain.

  14. Wide Field-of-View Fluorescence Imaging of Coral Reefs

    Science.gov (United States)

    Treibitz, Tali; Neal, Benjamin P.; Kline, David I.; Beijbom, Oscar; Roberts, Paul L. D.; Mitchell, B. Greg; Kriegman, David

    2015-01-01

    Coral reefs globally are declining rapidly because of both local and global stressors. Improved monitoring tools are urgently needed to understand the changes that are occurring at appropriate temporal and spatial scales. Coral fluorescence imaging tools have the potential to improve both ecological and physiological assessments. Although fluorescence imaging is regularly used for laboratory studies of corals, it has not yet been used for large-scale in situ assessments. Current obstacles to effective underwater fluorescence surveying include limited field-of-view due to low camera sensitivity, the need for nighttime deployment because of ambient light contamination, and the need for custom multispectral narrow band imaging systems to separate the signal into meaningful fluorescence bands. Here we describe the Fluorescence Imaging System (FluorIS), based on a consumer camera modified for greatly increased sensitivity to chlorophyll-a fluorescence, and we show high spectral correlation between acquired images and in situ spectrometer measurements. This system greatly facilitates underwater wide field-of-view fluorophore surveying during both night and day, and potentially enables improvements in semi-automated segmentation of live corals in coral reef photographs and juvenile coral surveys. PMID:25582836

  15. Wide-field single photon counting imaging with an ultrafast camera and an image intensifier

    Energy Technology Data Exchange (ETDEWEB)

    Zanda, Gianmarco, E-mail: gianmarco.zanda@kcl.ac.uk [King' s College London, Department of Physics, Strand, London WC2R 2LS (United Kingdom); Sergent, Nicolas; Green, Mark; Levitt, James A. [King' s College London, Department of Physics, Strand, London WC2R 2LS (United Kingdom); Petrasek, Zdenek [Biotechnologisches Zentrum, Technische Universitaet Dresden, Tatzberg 47/49, 01307 Dresden (Germany); Suhling, Klaus, E-mail: klaus.suhling@kcl.ac.uk [King' s College London, Department of Physics, Strand, London WC2R 2LS (United Kingdom)

    2012-12-11

    We are reporting a method for wide-field photon counting imaging using a CMOS camera with a 40 kHz frame rate coupled with a three-stage image intensifier mounted on a standard fluorescence microscope. This system combines high frame rates with single photon sensitivity. The output of the phosphor screen, consisting of single-photon events, is collected by a CMOS camera allowing to create a wide-field image with parallel positional and timing information of each photon. Using a pulsed excitation source and a luminescent sample, the arrival time of hundreds of photons can be determined simultaneously in many pixels with microsecond resolution.

  16. Wide-field single photon counting imaging with an ultrafast camera and an image intensifier

    Science.gov (United States)

    Zanda, Gianmarco; Sergent, Nicolas; Green, Mark; Levitt, James A.; Petrášek, Zdeněk; Suhling, Klaus

    2012-12-01

    We are reporting a method for wide-field photon counting imaging using a CMOS camera with a 40 kHz frame rate coupled with a three-stage image intensifier mounted on a standard fluorescence microscope. This system combines high frame rates with single photon sensitivity. The output of the phosphor screen, consisting of single-photon events, is collected by a CMOS camera allowing to create a wide-field image with parallel positional and timing information of each photon. Using a pulsed excitation source and a luminescent sample, the arrival time of hundreds of photons can be determined simultaneously in many pixels with microsecond resolution.

  17. THz Imaging by a Wide-band Compact FEL

    CERN Document Server

    Uk Jeong Young; Cheol Lee Byung; Hee-Park, S

    2004-01-01

    We have developed a laboratory-scale users facility with a compact THz FEL. The FEL operates in the wide wavelength range of 100–1200 μm, which corresponds to 0.3-3 THz. THz radiation from the FEL shows well collimated Gaussian spatial distribution and narrow spectral width of 0.3 μm, which is Fourier transform limited by the estimated pulse duration of 20 ps. The main application of the FEL is THz imaging for bio-medical researches. We are developing THz imaging techniques by 2-D scanning, single pulse capturing with the electro-optic method, and 3-D holography. High power, coherent, and pulsed feature of the FEL radiation is expected to show much better performance in advanced THz imaging of 3-D tomography by comparing with incoherent and weak THz sources. By controlling the optical delay between reference beam and scattered light from an object, we can get its 3-D tomography by the holograms. The coherent and pulse length of the FEL beam is measured to be 3-6 mm. In this paper we will show a...

  18. Preliminary Results on VLT K-band Imaging Observations of GRB ...

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... The derived magnitudes, combined with other photometric data taken from the literature, are used to investigate the – colors of GRB hosts. We do not find any extremely reddened starbursts in our sample, despite the capability of GRBs to trace star formation even in dusty regions. The observed – ...

  19. Compact K-band bandpass filter on high- k LiNbO 3 substrate

    Science.gov (United States)

    Wu, Chia-Sung; Liu, Hsing-Chung; Liu, Zhi-Ping; Chiu, Hsien-Chin

    2007-06-01

    A novel miniaturized microstrip-line filter with a pair of meandering resonators on lithium niobate LiNbO 3 substrate with a high dielectric constant is proposed. A stepped-impedance structure is integrated into this new filter simultaneously to reduce dimensions and suppress the spurious responses. A substrate with a high dielectric constant is also effective in reducing the filter size because it has a high coupling efficiency. The cross-coupling effect can be achieved in this designed filter. A copper (Cu) interconnection was also used in this investigation to improve further the quality factor and the insertion loss of this filter. The filter has two transmission zeros one on each side of the passband. The experimental results in the K-band verify the design.

  20. Substrate integrated waveguide (SIW 3 dB coupler for K-Band applications

    Directory of Open Access Journals (Sweden)

    Khalid Nurehansafwanah

    2017-01-01

    Full Text Available This paper presented a designed coupler by using Rogers RO4003C with thickness (h 0.508 mm and relative permittivity (εr 3.55. The four port network coupler operates in K-band (18-27 GHz and design by using substrate integrated waveguide (SIW method. The reflection coefficient and isolation coefficient of propose Substrate Integrated Waveguide (SIW coupler is below than -10 dB. Meanwhile the coupler requirements are phase shift 90° between coupled port and output. SIW are high performance broadband interconnects with excellent immunity to electromagnetic interference and suitable for use in microwave and communication electronics, as well as increase bandwidth systems. The designs of coupler are investigated using CST Microwave Studio simulation tool. This proposed couplers are varied from parameters that cover the frequency range (21 -24 GHz and better performance of scattering (S-parameter.

  1. K-Band Power Enbedded Transmission Line (ETL) MMIC Amplifiers for Satellite Communication Applications

    Science.gov (United States)

    Tserng, Hua-Quen; Ketterson, Andrew; Saunier, Paul; McCarty, Larry; Davis, Steve

    1998-01-01

    The design, fabrication, and performance of K-band high-efficiency, linear power pHEMT amplifiers implemented in Embedded Transmission Line (ETL) MMIC configuration with unthinned GaAs substrate and topside grounding are reported. A three-stage amplifier achieved a power-added efficiency of 40.5% with 264 mW output at 20.2 GHz. The linear gain is 28.5 dB with 1-dB gain compression output power of 200 mW and 31% power-added efficiency. The carrier-to-third-order intermodulation ratio is approx. 20 dBc at the 1-dB compression point. A RF functional yield of more than 90% has been achieved.

  2. Development of the wide field imager for Athena

    Science.gov (United States)

    Meidinger, Norbert; Eder, Josef; Fürmetz, Maria; Nandra, Kirpal; Pietschner, Daniel; Plattner, Markus; Rau, Arne; Reiffers, Jonas; Strecker, Rafael; Barbera, Marco; Brand, Thorsten; Wilms, Jörn

    2015-08-01

    The WFI (Wide Field Imager) instrument is planned to be one of two complementary focal plane cameras on ESA's next X-ray observatory Athena. It combines unprecedented survey power through its large field of view of 40 arcmin x 40 arcmin together with excellent count-rate capability (>= 1 Crab). The energy resolution of the silicon sensor is state-of-the-art in the energy band of interest from 0.2 keV to 15 keV, e.g. the full width at half maximum of a line at 6 keV will be MOSFET integrated onto a fully depleted 450 μm thick silicon bulk. Two different types of DEPFET sensors are planned for the WFI instrument: A set of four large-area sensors to cover the physical size of 14 cm x 14 cm in the focal plane and a single smaller gateable DEPFET sensor matrix optimized for high count-rate observations. Here we present the conceptual design of the instrument with focus on the critical subsystems and describe the instrument performance expectations. An outline of the model philosophy and the project organization completes the presentation.

  3. CHARACTERIZING THE COOL KOIs. VI. H- AND K-BAND SPECTRA OF KEPLER M DWARF PLANET-CANDIDATE HOSTS

    Energy Technology Data Exchange (ETDEWEB)

    Muirhead, Philip S. [Department of Astronomy, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Becker, Juliette; Price, Ellen M.; Thorp, Rachel; Riddle, Reed [California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Feiden, Gregory A. [Department of Physics and Astronomy, Uppsala University, Box 516, SE-75120 Uppsala (Sweden); Rojas-Ayala, Bárbara [Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Oporto (Portugal); Vanderburg, Andrew; Johnson, John Asher [Harvard College Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Law, Nicholas M. [Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3255 (United States); Baranec, Christoph [Institute for Astronomy, University of Hawai' i at Mānoa, Hilo, HI 96720-2700 (United States); Hamren, Katherine [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Schlawin, Everett; Lloyd, James P. [Department of Astronomy, Cornell University, Ithaca, NY 14583 (United States); Covey, Kevin R., E-mail: philipm@bu.edu [Lowell Observatory, 1400 W Mars Hill Road, Flagstaff, AZ 86001 (United States)

    2014-07-01

    We present H- and K-band spectra for late-type Kepler Objects of Interest (the {sup C}ool KOIs{sup )}: low-mass stars with transiting-planet candidates discovered by NASA's Kepler Mission that are listed on the NASA Exoplanet Archive. We acquired spectra of 103 Cool KOIs and used the indices and calibrations of Rojas-Ayala et al. to determine their spectral types, stellar effective temperatures, and metallicities, significantly augmenting previously published values. We interpolate our measured effective temperatures and metallicities onto evolutionary isochrones to determine stellar masses, radii, luminosities, and distances, assuming the stars have settled onto the main sequence. As a choice of isochrones, we use a new suite of Dartmouth predictions that reliably include mid-to-late M dwarf stars. We identify five M4V stars: KOI-961 (confirmed as Kepler 42), KOI-2704, KOI-2842, KOI-4290, and the secondary component to visual binary KOI-1725, which we call KOI-1725 B. We also identify a peculiar star, KOI-3497, which has Na and Ca lines consistent with a dwarf star but CO lines consistent with a giant. Visible-wavelength adaptive optics imaging reveals two objects within a 1 arcsec diameter; however, the objects' colors are peculiar. The spectra and properties presented in this paper serve as a resource for prioritizing follow-up observations and planet validation efforts for the Cool KOIs and are all available for download online using the ''data behind the figure'' feature.

  4. Airborne Wide Area Imager for Wildfire Mapping and Detection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An advanced airborne imaging system for fire detection/mapping is proposed. The goal of the project is to improve control and management of wildfires in order to...

  5. Airborne Wide Area Imager for Wildfire Mapping and Detection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An autonomous airborne imaging system for earth science research, disaster response, and fire detection is proposed. The primary goal is to improve information to...

  6. Monthly gravity field recovery from GRACE orbits and K-band measurements using variational equations approach

    Directory of Open Access Journals (Sweden)

    Changqing Wang

    2015-07-01

    Full Text Available The Gravity Recovery and Climate Experiment (GRACE mission can significantly improve our knowledge of the temporal variability of the Earth's gravity field. We obtained monthly gravity field solutions based on variational equations approach from GPS-derived positions of GRACE satellites and K-band range-rate measurements. The impact of different fixed data weighting ratios in temporal gravity field recovery while combining the two types of data was investigated for the purpose of deriving the best combined solution. The monthly gravity field solution obtained through above procedures was named as the Institute of Geodesy and Geophysics (IGG temporal gravity field models. IGG temporal gravity field models were compared with GRACE Release05 (RL05 products in following aspects: (i the trend of the mass anomaly in China and its nearby regions within 2005–2010; (ii the root mean squares of the global mass anomaly during 2005–2010; (iii time-series changes in the mean water storage in the region of the Amazon Basin and the Sahara Desert between 2005 and 2010. The results showed that IGG solutions were almost consistent with GRACE RL05 products in above aspects (i–(iii. Changes in the annual amplitude of mean water storage in the Amazon Basin were 14.7 ± 1.2 cm for IGG, 17.1 ± 1.3 cm for the Centre for Space Research (CSR, 16.4 ± 0.9 cm for the GeoForschungsZentrum (GFZ and 16.9 ± 1.2 cm for the Jet Propulsion Laboratory (JPL in terms of equivalent water height (EWH, respectively. The root mean squares of the mean mass anomaly in Sahara were 1.2 cm, 0.9 cm, 0.9 cm and 1.2 cm for temporal gravity field models of IGG, CSR, GFZ and JPL, respectively. Comparison suggested that IGG temporal gravity field solutions were at the same accuracy level with the latest temporal gravity field solutions published by CSR, GFZ and JPL.

  7. A World Wide Web Region-Based Image Search Engine

    OpenAIRE

    Kompatsiaris, Ioannis; Triantafyllou, Evangelia; Strintzis, Michael G.

    2001-01-01

    In this paper the development of an intelligent imagecontent-based search engine for the World Wide Web is presented.This system will offer a new form of media representationand access of content available in WWW. InformationWeb Crawlers continuously traverse the Internet and collectimages that are subsequently indexed based on integratedfeature vectors. As a basis for the indexing, the K-Meansalgorithm is used, modified so as to take into account thecoherence of the regions. Based on the ext...

  8. 76 FR 46854 - Hewlett Packard Company, Imaging and Printing Group, World Wide Product Data Management...

    Science.gov (United States)

    2011-08-03

    ... Employment and Training Administration Hewlett Packard Company, Imaging and Printing Group, World Wide..., 2010, applicable to workers of Hewlett Packard Company, Imaging and Printing Group, World Wide Products..., now known as Experis, were employed on-site at the Boise, Idaho location of Hewlett Packard Company...

  9. Integration of digital gross pathology images for enterprise-wide access

    Directory of Open Access Journals (Sweden)

    Milon Amin

    2012-01-01

    Full Text Available Background: Sharing digital pathology images for enterprise- wide use into a picture archiving and communication system (PACS is not yet widely adopted. We share our solution and 3-year experience of transmitting such images to an enterprise image server (EIS. Methods: Gross pathology images acquired by prosectors were integrated with clinical cases into the laboratory information system′s image management module, and stored in JPEG2000 format on a networked image server. Automated daily searches for cases with gross images were used to compile an ASCII text file that was forwarded to a separate institutional Enterprise Digital Imaging and Communications in Medicine (DICOM Wrapper (EDW server. Concurrently, an HL7-based image order for these cases was generated, containing the locations of images and patient data, and forwarded to the EDW, which combined data in these locations to generate images with patient data, as required by DICOM standards. The image and data were then "wrapped" according to DICOM standards, transferred to the PACS servers, and made accessible on an institution-wide basis. Results: In total, 26,966 gross images from 9,733 cases were transmitted over the 3-year period from the laboratory information system to the EIS. The average process time for cases with successful automatic uploads (n=9,688 to the EIS was 98 seconds. Only 45 cases (0.5% failed requiring manual intervention. Uploaded images were immediately available to institution- wide PACS users. Since inception, user feedback has been positive. Conclusions: Enterprise- wide PACS- based sharing of pathology images is feasible, provides useful services to clinical staff, and utilizes existing information system and telecommunications infrastructure. PACS-shared pathology images, however, require a "DICOM wrapper" for multisystem compatibility.

  10. Structured illumination for wide-field Raman imaging of cell membranes

    Science.gov (United States)

    Chen, Houkai; Wang, Siqi; Zhang, Yuquan; Yang, Yong; Fang, Hui; Zhu, Siwei; Yuan, Xiaocong

    2017-11-01

    Although the diffraction limit still restricts their lateral resolution, conventional wide-field Raman imaging techniques offer fast imaging speeds compared with scanning schemes. To extend the lateral resolution of wide-field Raman microscopy using filters, standing-wave illumination technique is used, and an improvement of lateral resolution by a factor of more than two is achieved. Specifically, functionalized surface enhanced Raman scattering nanoparticles are employed to strengthen the desired scattering signals to label cell membranes. This wide-field Raman imaging technique affords various significant opportunities in the biological applications.

  11. Properties of the Variation of the Infrared Emission of OH/IR Stars I. The K Band Light Curves

    Directory of Open Access Journals (Sweden)

    Kyung-Won Suh

    2009-09-01

    Full Text Available To study properties of the variation of the infrared emission of OH/IR stars, we collect and analyze the infrared observational data in K band for nine OH/IR stars. We use the observational data obtained for about three decades including recent data from the two micron all sky survey (2MASS and the deep near infrared survey of the southern sky (DENIS. We use Marquardt-Levenberg algorithm to determine the pulsation period and amplitude for each star and compare them with previous results of infrared and radio investigations.

  12. Direct transitions from high-K isomers to low-K bands -- {gamma} softness or coriolis coupling

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Yoshifumi R.; Narimatsu, Kanako; Ohtsubo, Shin-Ichi [Kyushu Univ., Fukuoka (Japan)] [and others

    1996-12-31

    Recent measurements of direct transitions from high-K isomers to low-K bands reveal severe break-down of the K-selection rule and pose the problem of how to understand the mechanism of such K-violation. The authors recent systematic calculations by using a simple {gamma}-tunneling model reproduced many of the observed hindrances, indicating the importance of the {gamma} softness. However, there are some data which cannot be explained in terms of the {gamma}-degree of freedom. In this talk, the authors also discuss the results of conventional Coriolis coupling calculations, which is considered to be another important mechanism.

  13. Hospital-wide PACS with a digital image intensifier TV system.

    Science.gov (United States)

    Okaniwa, H; Tsuneyoshi, H; Kabata, S; Satoh, K; Yokouchi, H; Okabe, T

    1994-05-01

    Tokyo Hitachi Hospital, Hitachi Ltd., has used a hospital-wide PACS for over 1 year. The system runs a 100 Mb/s optical fiber network over the whole hospital including wards and outpatient clinic rooms, with 11 image workstations. The network links digital imaging modalities such as X-CT, MRI, computed radiography (CR) and digital radiography (DR) with a 2048 x 2048 (2k x 2k) matrix image intensifier television (I.I.-TV) system. These modalities generate about 200 images/day. The system has managed over 300,000 images of about 8000 patients so far. Although being still under improvement, the system has really been used for routine work. The hospital-wide PACS of a small hospital has been proved to be very useful for both image diagnosis and image management.

  14. Wide Field-of-View (FOV) Soft X-Ray Imager Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Wide Field-of-View (FOV) Soft X-Ray Imager proposes to be a state-of-art instrument with applications for numerous heliospheric and planetary...

  15. A Compact, Wide Area Surveillance 3D Imaging LIDAR Providing UAS Sense and Avoid Capabilities Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Eye safe 3D Imaging LIDARS when combined with advanced very high sensitivity, large format receivers can provide a robust wide area search capability in a very...

  16. A K-Band RF-MEMS-Enabled Reconfigurable and Multifunctional Low-Noise Amplifier Hybrid Circuit

    OpenAIRE

    Malmqvist, R.; Samuelsson, C.; Gustafsson, A.; Rantakari, P.; Reyaz, S.; Vähä-Heikkilä, T.; Rydberg, A.; Varis, J.; Smith, D.; Baggen, R.

    2011-01-01

    A K-band (18–26.5 GHz) RF-MEMS-enabled reconfigurable and multifunctional dual-path LNA hybrid circuit (optimised for lowest/highest possible noise figure/linearity, resp.) is presented, together with its subcircuit parts. The two MEMS-switched low-NF (higher gain) and high-linearity (lower gain) LNA circuits (paths) present 16.0 dB/8.2 dB, 2.8 dB/4.9 dB and 15 dBm/20 dBm of small-signal gain, noise figure, and 1 dB compression point at 24 GHz, respectively. Compared with the two (fixed) LNA ...

  17. Investigation of ground target detection methods in fully polarimetric wide angle synthetic aperture radar images

    Science.gov (United States)

    Laggan, Wayne B.

    1995-03-01

    Target detection is a high priority of the Air Force for the purpose of reconnaissance and bombardment. This research investigates and develops methods to distinguish ground targets from clutter (i.e. foliage, landscape etc.) in Wide Angle Synthetic Aperture Radar (WASAR) images. WASAR uses multiple aspect angle SAR images of the same target scene. The WASAR data was generated from a pre-release software package (XPATCH-ES) provided by the sponsor (WL-AARA). A statistical analysis and feature extraction is performed on the XPATCH-ES data. Polarimetric and wide angle covariance matrices are estimated and analyzed. From an analysis of the wide angle covariance matrix it is shown that natural clutter has in general a uniform radar return for changing aspect angles, whereas the radar return for a target varies. Based on this analysis, two new wide angle algorithms, the WASAR Whitening Filter and the Adaptive WASAR Whitening Filter (AWWF) are developed. The target detection performance of polarimetric and multi aspect angle image combining algorithms are quantified using Receiver Operating Characteristic curves and target to clutter ratios. It is shown that wide angle processing provides superior target detection performance over polarimetric processing. Combinations of wide angle and polarimetric algorithms were used to achieve a 13.7 dB processing gain in target to clutter ratio when compared to unprocessed images of the target scene. This represents a significant improvement in target detection capabilities.

  18. A wide-FoV athermalized infrared imaging system with a two-element lens

    Science.gov (United States)

    Feng, Bin; Shi, Zelin; Zhao, Yaohong; Liu, Haizheng; Liu, Li

    2017-12-01

    For infrared imaging systems to achieve wide field of view (FoV), wide operating temperature and low weight, this work designs a wide-FoV athermalized infrared imaging system (AIIS) with a two-element lens. Its principle, design, manufacture, measurement and performance validation are successively discussed. The two-element lens contains four surfaces, where three aspheric surfaces are introduced to reduce optical off-axis aberrations and a cubic surface is introduced to achieve athermalization. The key coding mask containing an aspheric surface and a cubic surface is manufactured by nano-metric machining of ion implanted material (NiIM). Experimental results validate that our wide-FoV wavefront coding AIIS has a full FoV of 26.10° and an operating temperature over -20 °C to +70 °C.

  19. Wide-field TCSPC-based fluorescence lifetime imaging (FLIM) microscopy

    Science.gov (United States)

    Suhling, Klaus; Hirvonen, Liisa M.; Becker, Wolfgang; Smietana, Stefan; Netz, Holger; Milnes, James; Conneely, Thomas; Le Marois, Alix; Jagutzki, Ottmar

    2016-05-01

    Time-correlated single photon counting (TCSPC) is a widely used, sensitive, precise, robust and mature technique to measure photon arrival times in applications such as fluorescence spectroscopy and microscopy, light detection and ranging (lidar) and optical tomography. Wide-field TCSPC detection techniques, where the position and the arrival time of the photons are recorded simultaneously, have seen several advances in the last few years, from the microsecond to the picosecond time scale. Here, we summarise some of our recent work in this field with emphasis on microsecond resolution phosphorescence lifetime imaging (PLIM) and nanosecond fluorescence lifetime imaging (FLIM) microscopy.

  20. Wide-field mid-infrared hyperspectral imaging of adhesives using a bolometer camera

    OpenAIRE

    Sugawara, Shigeru; Nakayama, Yoshihiko; Taniguchi, Hideya; Ishimaru, Ichiro

    2017-01-01

    By combining a bolometer detector with an imaging-type interferometer, an inexpensive, easy-to-handle wide-field mid-infrared hyperspectral imaging apparatus was produced. We measured the distributions of four types of thin adhesive layers on an aluminium plate and analysed the results using correlation coefficients to visualise the distribution of various adhesives that cannot be discerned by the naked eye or conventional methods such as visible/near-infrared spectroscopic/fluorescent photog...

  1. Wide-field Imaging of the Environments of LITTLE THINGS Dwarf Irregular Galaxies

    Science.gov (United States)

    Hunter, Deidre A.; Melton, Casey; Leshin, Stephen; Wong, Alson; Clark, Maurice; Kamienski, Jerald; Moriya, Netzer; Packwood, Burley; Birket, Bob; Edwards, William; Millward, Mervyn; Wheelband, Ian

    2018-01-01

    We have obtained wide-field images of 36 of the 41 LITTLE THINGS (Local Irregulars That Trace Luminosity Extremes, The H I Nearby Galaxy Survey) nearby (limiting magnitudes of the images range from 19.7 to 28.3 mag arcsec‑2, with a median value of 25.9 mag arcsec‑2. We did not find any unknown companions. Two of the LITTLE THINGS galaxies, NGC 4163 and NGC 4214, and the fainter dwarf, UGCA 276, lie potentially within 100 kpc of each other, but our imaging does not reveal any stellar bridge between the galaxies. This project was part of the Lowell Amateur Research Initiative.

  2. Compressive imaging for difference image formation and wide-field-of-view target tracking

    Science.gov (United States)

    Shikhar

    2010-11-01

    Use of imaging systems for performing various situational awareness tasks in military and commercial settings has a long history. There is increasing recognition, however, that a much better job can be done by developing non-traditional optical systems that exploit the task-specific system aspects within the imager itself. In some cases, a direct consequence of this approach can be real-time data compression along with increased measurement fidelity of the task-specific features. In others, compression can potentially allow us to perform high-level tasks such as direct tracking using the compressed measurements without reconstructing the scene of interest. In this dissertation we present novel advancements in feature-specific (FS) imagers for large field-of-view surveillence, and estimation of temporal object-scene changes utilizing the compressive imaging paradigm. We develop these two ideas in parallel. In the first case we show a feature-specific (FS) imager that optically multiplexes multiple, encoded sub-fields of view onto a common focal plane. Sub-field encoding enables target tracking by creating a unique connection between target characteristics in superposition space and the target's true position in real space. This is accomplished without reconstructing a conventional image of the large field of view. System performance is evaluated in terms of two criteria: average decoding time and probability of decoding error. We study these performance criteria as a function of resolution in the encoding scheme and signal-to-noise ratio. We also include simulation and experimental results demonstrating our novel tracking method. In the second case we present a FS imager for estimating temporal changes in the object scene over time by quantifying these changes through a sequence of difference images. The difference images are estimated by taking compressive measurements of the scene. Our goals are twofold. First, to design the optimal sensing matrix for taking

  3. Astro-WISE Processing of Wide-field Images and Other Data

    NARCIS (Netherlands)

    Buddelmeijer, H.; Williams, O.R.; McFarland, J. P.; Belikov, A.; Ballester, P.; Egret, D.; Lorente, N.P.F.

    Astro-WISE (Vriend et al. 2012) is the Astronomical Wide-field Imaging System for Europe (Valentijn et al. 2007). It is a scientific information system which consists of hardware and software federated over about a dozen institutes throughout Europe. It has been developed to exploit the ever

  4. Focusing, imaging, and ATR for the Gotcha 2008 wide angle SAR collection

    Science.gov (United States)

    Gianelli, Christopher D.; Xu, Luzhou

    2013-05-01

    The following work discusses IAA's approach to tackling the wide angle, circular spotlight, synthetic aperture radar (SAR) problem from the 2008 Gotcha wide angle SAR data set, which is publicly released, with unlimited distribution. This data set comes with a MATLAB image formation routine and attendant graphical user inter- face (GUI). We begin by introducing a simple approach to focusing the collected phase history data that utilizes point targets (quadrahedral targets) present in the scene. Two SAR imaging algorithms are then presented, namely, the data-independent backprojection (BP) algorithm and the data-adaptive sparse learning via itera- tive minimization (SLIM) algorithm. These imaging approaches are compared using the 2008 Gotcha wide angle SAR data to perform both a clutter discrimination experiment, as well as an automatic target recognition (ATR) experiment. The ATR system is composed of a target pose and target center estimation preprocessing system, and includes a novel target feature for the final classification stage. Empirical results obtained by applying the focusing approach and imaging algorithms to the 2008 Gotcha wide angle SAR data set are presented and described. The results presented highlight the benefit of applying the SLIM algorithm over its data-independent counterpart, as well as the utility of the novel target feature.

  5. Scalable wide-field optical coherence tomography-based angiography for in vivo imaging applications.

    Science.gov (United States)

    Xu, Jingjiang; Wei, Wei; Song, Shaozhen; Qi, Xiaoli; Wang, Ruikang K

    2016-05-01

    Recent advances in optical coherence tomography (OCT)-based angiography have demonstrated a variety of biomedical applications in the diagnosis and therapeutic monitoring of diseases with vascular involvement. While promising, its imaging field of view (FOV) is however still limited (typically less than 9 mm(2)), which somehow slows down its clinical acceptance. In this paper, we report a high-speed spectral-domain OCT operating at 1310 nm to enable wide FOV up to 750 mm(2). Using optical microangiography (OMAG) algorithm, we are able to map vascular networks within living biological tissues. Thanks to 2,048 pixel-array line scan InGaAs camera operating at 147 kHz scan rate, the system delivers a ranging depth of ~7.5 mm and provides wide-field OCT-based angiography at a single data acquisition. We implement two imaging modes (i.e., wide-field mode and high-resolution mode) in the OCT system, which gives highly scalable FOV with flexible lateral resolution. We demonstrate scalable wide-field vascular imaging for multiple finger nail beds in human and whole brain in mice with skull left intact at a single 3D scan, promising new opportunities for wide-field OCT-based angiography for many clinical applications.

  6. Enterprise-wide PACS: beyond radiology, an architecture to manage all medical images.

    Science.gov (United States)

    Bandon, David; Lovis, Christian; Geissbühler, Antoine; Vallée, Jean-Paul

    2005-08-01

    Picture archiving and communication systems (PACS) have the vocation to manage all medical images acquired within the hospital. To address the various situations encountered in the imaging specialties, the traditional architecture used for the radiology department has to evolve. We present our preliminarily results toward an enterprise-wide PACS intended to support all kind of image production in medicine, from biomolecular images to whole-body pictures. Our solution is based on an existing radiologic PACS system from which images are distributed through an electronic patient record to all care facilities. This platform is enriched with a flexible integration framework supporting digital image communication in medicine (DICOM) and DICOM-XML formats. In addition, a generic workflow engine highly customizable is used to drive work processes. Echocardiology; hematology; ear, nose, and throat; and dermatology, including wounds, follow-up is the first implemented extensions outside of radiology. We also propose a global strategy for further developments based on three possible architectures for an enterprise-wide PACS.

  7. Optically sectioned wide-field fluorescence lifetime imaging endoscopy enabled by structured illumination (Conference Presentation)

    Science.gov (United States)

    Hinsdale, Taylor; Malik, Bilal H.; Rico-Jimenez, Jose J.; Jo, Javier A.; Maitland, Kristen C.

    2016-03-01

    We present a wide-field fluorescence lifetime imaging (FLIM) system with optical sectioning by structured illumination microscopy (SIM). FLIM measurements were made using a time gated ICCD camera in conjunction with a pulsed nitrogen dye laser operating at 450 nm. Intensity images were acquired at multiple time delays from a trigger initiated by a laser pulse to create a wide-field FLIM image, which was then combined with three phase SIM to provide optical sectioning. Such a mechanism has the potential to increase the reliability and accuracy of the FLIM measurements by rejecting background intensity. SIM also provides the opportunity to create volumetric FLIM images with the incorporation of scanning mechanisms for the sample plane. We present multiple embodiments of such a system: one as a free space endoscope and the other as a fiber microendoscope enabled by the introduction of a fiber bundle. Finally, we demonstrate the efficacy of such an imaging system by imaging dyes embedded in a tissue phantom.

  8. Backscanning step and stare imaging system with high frame rate and wide coverage.

    Science.gov (United States)

    Sun, Chongshang; Ding, Yalin; Wang, Dejiang; Tian, Dapeng

    2015-06-01

    Step and stare imaging with staring arrays has become the main approach to realizing wide area coverage and high resolution imagery of potential targets. In this paper, a backscanning step and stare imaging system is described. Compared with traditional step and stare imaging systems, this system features a much higher frame rate by using a small-sized array. In order to meet the staring requirements, a fast steering mirror is employed to provide backscan motion to compensate for the image motion caused by the continuously scanning of the gimbal platform. According to the working principle, the control system is designed to step/stare the line of sight at a high frame rate with a high accuracy. Then a proof-of-concept backscanning step and stare imaging system is established with a CMOS camera. Finally, the modulation transfer function of the imaging system is measured by the slanted-edge method, and a quantitative analysis is made to evaluate the performance of image motion compensation. Experimental results confirm that both high frame rate and image quality improvement can be achieved by adopting this method.

  9. A K-Band RF-MEMS-Enabled Reconfigurable and Multifunctional Low-Noise Amplifier Hybrid Circuit

    Directory of Open Access Journals (Sweden)

    R. Malmqvist

    2011-01-01

    Full Text Available A K-band (18–26.5 GHz RF-MEMS-enabled reconfigurable and multifunctional dual-path LNA hybrid circuit (optimised for lowest/highest possible noise figure/linearity, resp. is presented, together with its subcircuit parts. The two MEMS-switched low-NF (higher gain and high-linearity (lower gain LNA circuits (paths present 16.0 dB/8.2 dB, 2.8 dB/4.9 dB and 15 dBm/20 dBm of small-signal gain, noise figure, and 1 dB compression point at 24 GHz, respectively. Compared with the two (fixed LNA subcircuits used within this design, the MEMS-switched LNA circuit functions show minimum 0.6–1.3 dB higher NF together with similar values of P1 dB at 18–25 GHz. The gain of one LNA circuit path is reduced by 25–30 dB when the MEMS switch and active circuitry used within in the same switching branch are switched off to select the other LNA path and minimise power consumption.

  10. High-Efficiency K-Band Space Traveling-Wave Tube Amplifier for Near-Earth High Data Rate Communications

    Science.gov (United States)

    Simons, Rainee N.; Force, Dale A.; Spitsen, Paul C.; Menninger, William L.; Robbins, Neal R.; Dibb, Daniel R.; Todd, Phillip C.

    2010-01-01

    The RF performance of a new K-Band helix conduction cooled traveling-wave tube amplifier (TWTA), is presented in this paper. A total of three such units were manufactured, tested and delivered. The first unit is currently flying onboard NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft and has flawlessly completed over 2000 orbits around the Moon. The second unit is a proto-flight model. The third unit will fly onboard NASA's International Space Station (ISS) as a very compact and lightweight transmitter package for the Communications, Navigation and Networking Reconfigurable Testbed (CoNNeCT), which is scheduled for launch in 2011. These TWTAs were characterized over the frequencies 25.5 to 25.8 GHz. The saturated RF output power is greater than 40 W and the saturated RF gain is greater than 46 dB. The saturated AM-to-PM conversion is 3.5 /dB and the small signal gain ripple is 0.46 dB peak-to-peak. The overall efficiency of the TWTA, including that of the electronic power conditioner (EPC) is as high as 45%.

  11. NIR Imaging of the AKARI North Ecliptic Pole Wide Survey Field

    Science.gov (United States)

    Im, Myungshin; Lee, Hyung Mok; Lee, Myung Gyoon; Matsuhara, Hideo; Wada, Takehiko; Oyabu, Shinki; Akari Nep Survey Team

    2008-02-01

    We propose to perform J- and H-band wide-field imaging of the north ecliptic pole (NEP) area which has been surveyed by the AKARI Infrared Space Telescope. The NEP-Wide survey, one of the AKARI's key scientific programs, images a 5.8 deg^2 circular area centered on the north ecliptic pole with contiguous 9 passbands between 2.5 and 24 (micron) to the flux limit ranging from 15 (mu)Jy to 500 (mu)Jy (plus FIR data), including 11, 15, and 18 (micron) bands where the Spitzer has limitations. Thus, NEP-Wide is the only wide-area IR survey that allows us to study the evolution of various mid-IR features from z=0 to z=2 such as PAHs, silicate absorptions, and power-slopes of AGNs, and their connection to IR-luminosity, star formation and AGN activities of IR sources not bright enough for the Spitzer spectroscopy. Optical imaging as well as radio/X-ray data exist over this field, however there is a gaping hole at NIR between the AKARI and the optical coverage. In order to fill the wavelength gap, we propose to obtain J-, and H-band images to 15 (mu)Jy at 5-σ using FLAMINGOS on the 2.1-m. Filling the hole in the spectral energy distribution will significantly increase the value of the NEP-Wide dataset by permitting us to add more accurate stellar mass and photo-z estimates, and also a large number of SEDs from optical to IR without a gap in wavelength coverage.

  12. Speckle correlation resolution enhancement of wide-field fluorescence imaging (Conference Presentation)

    Science.gov (United States)

    Yilmaz, Hasan

    2016-03-01

    Structured illumination enables high-resolution fluorescence imaging of nanostructures [1]. We demonstrate a new high-resolution fluorescence imaging method that uses a scattering layer with a high-index substrate as a solid immersion lens [2]. Random scattering of coherent light enables a speckle pattern with a very fine structure that illuminates the fluorescent nanospheres on the back surface of the high-index substrate. The speckle pattern is raster-scanned over the fluorescent nanospheres using a speckle correlation effect known as the optical memory effect. A series of standard-resolution fluorescence images per each speckle pattern displacement are recorded by an electron-multiplying CCD camera using a commercial microscope objective. We have developed a new phase-retrieval algorithm to reconstruct a high-resolution, wide-field image from several standard-resolution wide-field images. We have introduced phase information of Fourier components of standard-resolution images as a new constraint in our algorithm which discards ambiguities therefore ensures convergence to a unique solution. We demonstrate two-dimensional fluorescence images of a collection of nanospheres with a deconvolved Abbe resolution of 116 nm and a field of view of 10 µm × 10 µm. Our method is robust against optical aberrations and stage drifts, therefore excellent for imaging nanostructures under ambient conditions. [1] M. G. L. Gustafsson, J. Microsc. 198, 82-87 (2000). [2] H. Yilmaz, E. G. van Putten, J. Bertolotti, A. Lagendijk, W. L. Vos, and A. P. Mosk, Optica 2, 424-429 (2015).

  13. Cost-effective and compact wide-field fluorescent imaging on a cell-phone.

    Science.gov (United States)

    Zhu, Hongying; Yaglidere, Oguzhan; Su, Ting-Wei; Tseng, Derek; Ozcan, Aydogan

    2011-01-21

    We demonstrate wide-field fluorescent and darkfield imaging on a cell-phone with compact, light-weight and cost-effective optical components that are mechanically attached to the existing camera unit of the cell-phone. For this purpose, we used battery powered light-emitting diodes (LEDs) to pump the sample of interest from the side using butt-coupling, where the pump light was guided within the sample cuvette to uniformly excite the specimen. The fluorescent emission from the sample was then imaged using an additional lens that was positioned right in front of the existing lens of the cell-phone camera. Because the excitation occurs through guided waves that propagate perpendicular to our detection path, an inexpensive plastic colour filter was sufficient to create the dark-field background required for fluorescent imaging, without the need for a thin-film interference filter. We validate the performance of this platform by imaging various fluorescent micro-objects in 2 colours (i.e., red and green) over a large field-of-view (FOV) of ∼81 mm(2) with a raw spatial resolution of ∼20 μm. With additional digital processing of the captured cell-phone images, through the use of compressive sampling theory, we demonstrate ∼2 fold improvement in our resolving power, achieving ∼10 μm resolution without a trade-off in our FOV. Further, we also demonstrate darkfield imaging of non-fluorescent specimen using the same interface, where this time the scattered light from the objects is detected without the use of any filters. The capability of imaging a wide FOV would be exceedingly important to probe large sample volumes (e.g., >0.1 mL) of e.g., blood, urine, sputum or water, and for this end we also demonstrate fluorescent imaging of labeled white-blood cells from whole blood samples, as well as water-borne pathogenic protozoan parasites such as Giardia Lamblia cysts. Weighing only ∼28 g (∼1 ounce), this compact and cost-effective fluorescent imaging platform

  14. A Wide Field Auroral Imager (WFAI for low Earth orbit missions

    Directory of Open Access Journals (Sweden)

    N. P. Bannister

    2007-03-01

    Full Text Available A comprehensive understanding of the solar wind interaction with Earth's coupled magnetosphere-ionosphere system requires an ability to observe the charged particle environment and auroral activity from the same platform, generating particle and photon image data which are matched in time and location. While unambiguous identification of the particles giving rise to the aurora requires a Low Earth Orbit satellite, obtaining adequate spatial coverage of aurorae with the relatively limited field of view of current space bourne auroral imaging systems requires much higher orbits. A goal for future satellite missions, therefore, is the development of compact, wide field-of-view optics permitting high spatial and temporal resolution ultraviolet imaging of the aurora from small spacecraft in low polar orbit. Microchannel plate optics offer a method of achieving the required performance. We describe a new, compact instrument design which can observe a wide field-of-view with the required spatial resolution. We report the focusing of 121.6 nm radiation using a spherically-slumped, square-pore microchannel plate with a focal length of 32 mm and an F number of 0.7. Measurements are compared with detailed ray-trace simulations of imaging performance. The angular resolution is 2.7±0.2° for the prototype, corresponding to a footprint ~33 km in diameter for an aurora altitude of 110 km and a spacecraft altitude of 800 km. In preliminary analysis, a more recent optic has demonstrated a full width at half maximum of 5.0±0.3 arcminutes, corresponding to a footprint of ~1 km from the same spacecraft altitude. We further report the imaging properties of a convex microchannel plate detector with planar resistive anode readout; this detector, whose active surface has a radius of curvature of only 100 mm, is shown to meet the spatial resolution and sensitivity requirements of the new wide field auroral imager (WFAI.

  15. Wide-azimuth angle-domain imaging for anisotropic reverse-time migration

    KAUST Repository

    Sava, Paul C.

    2011-01-01

    Extended common-image-point gathers (CIP) constructed by wide-azimuth TI wave-equation migration contain all the necessary information for angle decomposition as a function of the reflection and azimuth angles at selected locations in the subsurface. The reflection and azimuth angles are derived from the extended images using analytic relations between the space-lag and time-lag extensions. This post-imaging decomposition requires only information which is already available at the time of migration, i.e. the model parameters and the tilt angles of the TI medium. The transformation amounts to a linear Radon transform applied to the CIPs obtained after the application of the extended imaging condition. If information about the reflector dip is available at the CIP locations, then only two components of the space-lag vectors are required, thus reducing computational cost and increasing the affordability of the method. This efficient angle decomposition method is suitable for wide-azimuth imaging in anisotropic media with arbitrary orientation of the symmetry plane. © 2011 Society of Exploration Geophysicists.

  16. Wide-field and high-resolution optical imaging for early detection of oral neoplasia

    Science.gov (United States)

    Pierce, Mark C.; Schwarz, Richard A.; Rosbach, Kelsey; Roblyer, Darren; Muldoon, Tim; Williams, Michelle D.; El-Naggar, Adel K.; Gillenwater, Ann M.; Richards-Kortum, Rebecca

    2010-02-01

    Current procedures for oral cancer screening typically involve visual inspection of the entire tissue surface at risk under white light illumination. However, pre-cancerous lesions can be difficult to distinguish from many benign conditions when viewed under these conditions. We have developed wide-field (macroscopic) imaging system which additionally images in cross-polarized white light, narrowband reflectance, and fluorescence imaging modes to reduce specular glare, enhance vascular contrast, and detect disease-related alterations in tissue autofluorescence. We have also developed a portable system to enable high-resolution (microscopic) evaluation of cellular features within the oral mucosa in situ. This system is a wide-field epi-fluorescence microscope coupled to a 1 mm diameter, flexible fiber-optic imaging bundle. Proflavine solution was used to specifically label cell nuclei, enabling the characteristic differences in N/C ratio and nuclear distribution between normal, dysplastic, and cancerous oral mucosa to be quantified. This paper discusses the technical design and performance characteristics of these complementary imaging systems. We will also present data from ongoing clinical studies aimed at evaluating diagnostic performance of these systems for detection of oral neoplasia.

  17. Testing a new surfactant in a widely-used blood mimic for ultrasound flow imaging.

    Science.gov (United States)

    Zhou, Xiaowei; Hoskins, Peter R

    2017-11-01

    A blood-mimicking fluid developed by Ramnarine et al. has been widely used in flow phantoms for ultrasound flow imaging research, and it has also been cited by IEC 61685 as a reference for making blood-mimicking fluid.However, the surfactant material Synperonic N in this blood-mimicking fluid recipe is phased out from the European market due to environmental issues. The aim of this study is to test whether Synperonic N can be substituted by biodegradable Synperonic A7 in making blood-mimicking fluid for ultrasound flow imaging research. A flow phantom was fabricated to test the blood-mimicking fluid with Synperonic N and Synperonic A7 as surfactants separately. Doppler images and velocity data were collected using a clinical ultrasound scanner under constant and pulsatile flows; and images and measured velocities were compared. It was found that both blood mimics can provide exactly the same images under spectral Doppler ultrasound and colour Doppler ultrasound in terms of their image qualities. The maximum velocities under constant flow were measured by the spectral Doppler ultrasound as 0.4714 ± 0.001 m.s-1 and 0.4644 ± 0.001 m.s-1 for blood-mimicking fluid with Synperonic N and blood-mimicking fluid with Synperonic A7, respectively. Measured velocities using the two different blood-mimicking fluids were statistically different (p flow imaging research.

  18. Wide area 2D/3D imaging development, analysis and applications

    CERN Document Server

    Langmann, Benjamin

    2014-01-01

    Imaging technology is an important research area and it is widely utilized in a growing number of disciplines ranging from gaming, robotics and automation to medicine. In the last decade 3D imaging became popular mainly driven by the introduction of novel 3D cameras and measuring devices. These cameras are usually limited to indoor scenes with relatively low distances. Benjamin Langmann introduces medium and long-range 2D/3D cameras to overcome these limitations. He reports measurement results for these devices and studies their characteristic behavior. In order to facilitate the application o

  19. Automatic detection of diabetic retinopathy features in ultra-wide field retinal images

    Science.gov (United States)

    Levenkova, Anastasia; Sowmya, Arcot; Kalloniatis, Michael; Ly, Angelica; Ho, Arthur

    2017-03-01

    Diabetic retinopathy (DR) is a major cause of irreversible vision loss. DR screening relies on retinal clinical signs (features). Opportunities for computer-aided DR feature detection have emerged with the development of Ultra-WideField (UWF) digital scanning laser technology. UWF imaging covers 82% greater retinal area (200°), against 45° in conventional cameras3 , allowing more clinically relevant retinopathy to be detected4 . UWF images also provide a high resolution of 3078 x 2702 pixels. Currently DR screening uses 7 overlapping conventional fundus images, and the UWF images provide similar results1,4. However, in 40% of cases, more retinopathy was found outside the 7-field ETDRS) fields by UWF and in 10% of cases, retinopathy was reclassified as more severe4 . This is because UWF imaging allows examination of both the central retina and more peripheral regions, with the latter implicated in DR6 . We have developed an algorithm for automatic recognition of DR features, including bright (cotton wool spots and exudates) and dark lesions (microaneurysms and blot, dot and flame haemorrhages) in UWF images. The algorithm extracts features from grayscale (green "red-free" laser light) and colour-composite UWF images, including intensity, Histogram-of-Gradient and Local binary patterns. Pixel-based classification is performed with three different classifiers. The main contribution is the automatic detection of DR features in the peripheral retina. The method is evaluated by leave-one-out cross-validation on 25 UWF retinal images with 167 bright lesions, and 61 other images with 1089 dark lesions. The SVM classifier performs best with AUC of 94.4% / 95.31% for bright / dark lesions.

  20. Automatic Processing of Chinese GF-1 Wide Field of View Images

    Science.gov (United States)

    Zhang, Y.; Wan, Y.; Wang, B.; Kang, Y.; Xiong, J.

    2015-04-01

    The wide field of view (WFV) imaging instrument carried on the Chinese GF-1 satellite includes four cameras. Each camera has 200km swath-width that can acquire earth image at the same time and the observation can be repeated within only 4 days. This enables the applications of remote sensing imagery to advance from non-scheduled land-observation to periodically land-monitoring in the areas that use the images in such resolutions. This paper introduces an automatic data analysing and processing technique for the wide-swath images acquired by GF-1 satellite. Firstly, the images are validated by a self-adaptive Gaussian mixture model based cloud detection method to confirm whether they are qualified and suitable to be involved into the automatic processing workflow. Then the ground control points (GCPs) are quickly and automatically matched from the public geo-information products such as the rectified panchromatic images of Landsat-8. Before the geometric correction, the cloud detection results are also used to eliminate the invalid GCPs distributed in the cloud covered areas, which obviously reduces the ratio of blunders of GCPs. The geometric correction module not only rectifies the rational function models (RFMs), but also provides the self-calibration model and parameters for the non-linear distortion, and it is iteratively processed to detect blunders. The maximum geometric distortion in WFV image decreases from about 10-15 pixels to 1-2 pixels when compensated by self-calibration model. The processing experiments involve hundreds of WFV images of GF-1 satellite acquired from June to September 2013, which covers the whole mainland of China. All the processing work can be finished by one operator within 2 days on a desktop computer made up by a second-generation Intel Core-i7 CPU and a 4-solid-State-Disk array. The digital ortho maps (DOM) are automatically generated with 3 arc second Shuttle Radar Topography Mission (SRTM). The geometric accuracies of the

  1. Efficient Terahertz Wide-Angle NUFFT-Based Inverse Synthetic Aperture Imaging Considering Spherical Wavefront

    Directory of Open Access Journals (Sweden)

    Jingkun Gao

    2016-12-01

    Full Text Available An efficient wide-angle inverse synthetic aperture imaging method considering the spherical wavefront effects and suitable for the terahertz band is presented. Firstly, the echo signal model under spherical wave assumption is established, and the detailed wavefront curvature compensation method accelerated by 1D fast Fourier transform (FFT is discussed. Then, to speed up the reconstruction procedure, the fast Gaussian gridding (FGG-based nonuniform FFT (NUFFT is employed to focus the image. Finally, proof-of-principle experiments are carried out and the results are compared with the ones obtained by the convolution back-projection (CBP algorithm. The results demonstrate the effectiveness and the efficiency of the presented method. This imaging method can be directly used in the field of nondestructive detection and can also be used to provide a solution for the calculation of the far-field RCSs (Radar Cross Section of targets in the terahertz regime.

  2. Widely tunable, high peak power ultrafast laser sources in biological imaging (Conference Presentation)

    Science.gov (United States)

    Klein, Julien

    2017-02-01

    Widely tunable ultrafast lasers have enabled a large number of biological imaging techniques including point scanning multiphoton excited fluorescence (MPEF), SHG/THG and stimulated Raman imaging. Tunable ultrafast lasers offer spectral agility, covering the entire relative transparency window in live tissue (700-1300nnm) and flexibility with multi-color, synchronized outputs to support sophisticated label free techniques (e.g. stimulated Raman modalities). More recently newly available high peak power lasers based on Ytterbium technology drive advances in two-photon light-sheet, 3 photon excited fluorescence and holographic patterning for optogenetics photo-stimulation. These laser platforms offer a unique blend of compactness, ease of use and cost efficiency, and ideally complement tunable platforms typically based on Ti:Sapphire and IR optical parametric oscillators (OPO). We present various types of ultrafast laser architectures, link their optical characteristics to key bio-imaging requirements, and present relevant examples and images illustrating their impact in biological science. In particular we review the use of ultrafast lasers in optogenetics and fast in-vivo Calcium imaging deep in mouse brain.

  3. Microlensing Surveys of M31 in the Wide Field Imaging ERA

    Energy Technology Data Exchange (ETDEWEB)

    Baltz, E.

    2004-10-27

    The Andromeda Galaxy (M31) is the closest large galaxy to the Milky Way, thus it is an important laboratory for studying massive dark objects in galactic halos (MACHOs) by gravitational microlensing. Such studies strongly complement the studies of the Milky Way halo using the Large and Small Magellanic Clouds. We consider the possibilities for microlensing surveys of M31 using the next generation of wide field imaging telescopes with fields of view in the square degree range. We consider proposals for such imagers both on the ground and in space. For concreteness, we specialize to the SNAP proposal for a space telescope and the LSST proposal for a ground based telescope. We find that a modest space-based survey of 50 visits of one hour each is considerably better than current ground based surveys covering 5 years. Crucially, systematic effects can be considerably better controlled with a space telescope because of both the infrared sensitivity and the angular resolution. To be competitive, 8 meter class wide-field ground based imagers must take exposures of several hundred seconds with several day cadence.

  4. Wide-field mid-infrared hyperspectral imaging of adhesives using a bolometer camera.

    Science.gov (United States)

    Sugawara, Shigeru; Nakayama, Yoshihiko; Taniguchi, Hideya; Ishimaru, Ichiro

    2017-09-29

    By combining a bolometer detector with an imaging-type interferometer, an inexpensive, easy-to-handle wide-field mid-infrared hyperspectral imaging apparatus was produced. We measured the distributions of four types of thin adhesive layers on an aluminium plate and analysed the results using correlation coefficients to visualise the distribution of various adhesives that cannot be discerned by the naked eye or conventional methods such as visible/near-infrared spectroscopic/fluorescent photography. The measurement wavelength range, obtained spectrum's wavenumber resolution, and measurement time was 8-14 μm, about 9 cm-1, and about 30 s, respectively. Using conventional methods, adhesives could not be distinguished from the others. By using this method, we found that adhesives could be precisely distinguished by setting an appropriate threshold value for the correlation coefficient. Thus, our approach can accurately measure the spatial distribution of different types of adhesive that cannot be discriminated by conventional methods.

  5. High throughput holographic imaging-in-flow for the analysis of a wide plankton size range.

    Science.gov (United States)

    Yourassowsky, Catherine; Dubois, Frank

    2014-03-24

    We developed a Digital Holographic Microscope (DHM) working with a partial coherent source specifically adapted to perform high throughput recording of holograms of plankton organisms in-flow, in a size range of 3 µm-300 µm, which is of importance for this kind of applications. This wide size range is achieved with the same flow cell and with the same microscope magnification. The DHM configuration combines a high magnification with a large field of view and provides high-resolution intensity and quantitative phase images refocusing on high sample flow rate. Specific algorithms were developed to detect and extract automatically the particles and organisms present in the samples in order to build holograms of each one that are used for holographic refocusing and quantitative phase contrast imaging. Experimental results are shown and discussed.

  6. Note: Grazing incidence small and wide angle x-ray scattering combined with imaging ellipsometry

    Energy Technology Data Exchange (ETDEWEB)

    Koerstgens, V.; Meier, R.; Ruderer, M. A.; Guo, S.; Chiang, H.-Y.; Mueller-Buschbaum, P. [Technische Universitaet Muenchen, Physik-Department, Lehrstuhl fuer Funktionelle Materialien, James-Franck-Str. 1, 85748 Garching (Germany); Perlich, J.; Roth, S. V.; Gehrke, R. [HASYLAB, DESY, Notkestr. 85, 22607, Hamburg (Germany)

    2012-07-15

    The combination of grazing incidence small angle x-ray scattering (GISAXS) and grazing incidence wide angle x-ray scattering (GIWAXS) with optical imaging ellipsometry is presented as an upgrade of the available measurement techniques at the wiggler beamline BW4 of the Hamburger Synchrotronstrahlungslabor. The instrument is introduced with the description of the alignment procedure to assure the measurement of imaging ellipsometry and GISAXS/GIWAXS on the same sample spot. To demonstrate the possibilities of the new instrument examples of morphological investigation on films made of poly(3-hexylthiophene) and [6,6]-phenyl-C{sub 61} butyric acid methyl ester as well as textured poly(9,9-dioctylfluorene-alt-benzo-thia-diazole) are shown.

  7. Wide-field fluorescent microscopy and fluorescent imaging flow cytometry on a cell-phone.

    Science.gov (United States)

    Zhu, Hongying; Ozcan, Aydogan

    2013-04-11

    Fluorescent microscopy and flow cytometry are widely used tools in biomedical research and clinical diagnosis. However these devices are in general relatively bulky and costly, making them less effective in the resource limited settings. To potentially address these limitations, we have recently demonstrated the integration of wide-field fluorescent microscopy and imaging flow cytometry tools on cell-phones using compact, light-weight, and cost-effective opto-fluidic attachments. In our flow cytometry design, fluorescently labeled cells are flushed through a microfluidic channel that is positioned above the existing cell-phone camera unit. Battery powered light-emitting diodes (LEDs) are butt-coupled to the side of this microfluidic chip, which effectively acts as a multi-mode slab waveguide, where the excitation light is guided to uniformly excite the fluorescent targets. The cell-phone camera records a time lapse movie of the fluorescent cells flowing through the microfluidic channel, where the digital frames of this movie are processed to count the number of the labeled cells within the target solution of interest. Using a similar opto-fluidic design, we can also image these fluorescently labeled cells in static mode by e.g. sandwiching the fluorescent particles between two glass slides and capturing their fluorescent images using the cell-phone camera, which can achieve a spatial resolution of e.g. - 10 μm over a very large field-of-view of - 81 mm(2). This cell-phone based fluorescent imaging flow cytometry and microscopy platform might be useful especially in resource limited settings, for e.g. counting of CD4+ T cells toward monitoring of HIV+ patients or for detection of water-borne parasites in drinking water.

  8. Mapping of summer sea ice in the Chukchi Sea using KOMPSAT-5 wide swath SAR images

    Science.gov (United States)

    Han, H.; Kim, H. C.

    2016-12-01

    Synthetic Aperture Radar (SAR) has been widely used for mapping sea ice because it can observe Earth's surface regardless of sun altitudes and weather conditions. Korea Multi-Purpose SATellte-5 (KOMPSAT-5) is South Korea's first satellite equipped with X-band SAR system that provides high-resolution images in various observation modes. In this study, sea ice mapping model based on Random Forest (RF), a rule-based machine learning approach, was developed for KOMPSAT-5 Enhanced Wide (EW) swath SAR data obtained from August to September 2015 in the Chukchi Sea of the Arctic Ocean. All SAR images were acquired in HH-polarization at incidence angle ranging from 17 to 50°. Each SAR image covers the area of 100 km × 100 km. A total of 12 texture features derived from backscattering intensity and grey level co-occurrence matrix (GLCM) were used as input variables for sea ice mapping model. The sea ice mapping model based on the RF produced sea ice map with a grid size of 125 m, with the overall accuracy of 99.2% and the kappa coefficient of 98.5% in the classification of sea ice and open water. Sea ice concentration (SIC) was computed from the RF-derived sea ice maps and compared with that from the observations of two passive microwave sensors— the Special Sensor Microwave Imager/Sounder (SSMIS) and the Advanced Microwave Scanning Radiometer 2 (AMSR2). SSMIS and AMSR2 estimates SIC using the NASA Team (NT) and Turbulence Interaction STudy (ARTIST) Sea Ice (ASI) algorithm, respectively. The SSMIS NT SIC was underestimated in marginal ice zone and compact ice zone, while they were overestimated in sea ice edge. Meanwhile, the AMSR2 ASI SIC was underestimated in compact ice zone and overestimated in other regions. This research was funded by the Korea Polar Research Institute (KOPRI) under the project titled `SaTellite remote sensing on west Antarctic ocean Research (STAR) (PE16040)'.

  9. New Approach for Unambiguous High-Resolution Wide-Swath SAR Imaging

    Directory of Open Access Journals (Sweden)

    Yueguan Lin

    2014-01-01

    Full Text Available The high-resolution wide-swath (HRWS SAR system uses a small antenna for transmitting waveform and multiple antennas both in elevation and azimuth for receiving echoes. It has the potential to achieve wide spatial coverage and fine azimuth resolution, while it suffers from elevation pattern loss caused by the presence of topographic height and impaired azimuth resolution caused by nonuniform sampling. A new approach for HRWS SAR imaging based on compressed sensing (CS is introduced. The data after range compression of multiple elevation apertures are used to estimate direction of arrival (DOA of targets via CS, and the adaptive digital beamforming in elevation is achieved accordingly, which avoids the pattern loss of scan-on-receive (SCORE algorithm when topographic height exists. The effective phase centers of the system are nonuniformly distributed when displaced phase center antenna (DPCA technology is adopted, which causes Doppler ambiguities under traditional SAR imaging algorithms. Azimuth reconstruction based on CS can resolve this problem via precisely modeling the nonuniform sampling. Validation with simulations and experiment in an anechoic chamber are presented.

  10. Wide-field imaging through scattering media by scattered light fluorescence microscopy

    Science.gov (United States)

    Zhou, Yulan; Li, Xun

    2017-08-01

    To obtain images through scattering media, scattered light fluorescence (SLF) microscopy that utilizes the optical memory effect has been developed. However, the small field of view (FOV) of SLF microscopy limits its application. In this paper, we have introduced a re-modulation method to achieve wide-field imaging through scattering media by SLF microscopy. In the re-modulation method, to raster scan the focus across the object plane, the incident wavefront is re-modulated via a spatial light modulator (SLM) in the updated phase compensation calculated using the optimized iterative algorithm. Compared with the conventional optical memory effect method, the re-modulation method can greatly increase the FOV of a SLF microscope. With the phase compensation theoretically calculated, the process of updating the phase compensation of a high speed SLM is fast. The re-modulation method does not increase the imaging time. The re-modulation method is, therefore, expected to make SLF microscopy have much wider applications in biology, medicine and physiology.

  11. Automated segmentation of oral mucosa from wide-field OCT images (Conference Presentation)

    Science.gov (United States)

    Goldan, Ryan N.; Lee, Anthony M. D.; Cahill, Lucas; Liu, Kelly; MacAulay, Calum; Poh, Catherine F.; Lane, Pierre

    2016-03-01

    Optical Coherence Tomography (OCT) can discriminate morphological tissue features important for oral cancer detection such as the presence or absence of basement membrane and epithelial thickness. We previously reported an OCT system employing a rotary-pullback catheter capable of in vivo, rapid, wide-field (up to 90 x 2.5mm2) imaging in the oral cavity. Due to the size and complexity of these OCT data sets, rapid automated image processing software that immediately displays important tissue features is required to facilitate prompt bed-side clinical decisions. We present an automated segmentation algorithm capable of detecting the epithelial surface and basement membrane in 3D OCT images of the oral cavity. The algorithm was trained using volumetric OCT data acquired in vivo from a variety of tissue types and histology-confirmed pathologies spanning normal through cancer (8 sites, 21 patients). The algorithm was validated using a second dataset of similar size and tissue diversity. We demonstrate application of the algorithm to an entire OCT volume to map epithelial thickness, and detection of the basement membrane, over the tissue surface. These maps may be clinically useful for delineating pre-surgical tumor margins, or for biopsy site guidance.

  12. Wide-field OCT imaging of oral lesions in vivo: quantification and classification (Conference Presentation)

    Science.gov (United States)

    Raizada, Rashika; Lee, Anthony M. D.; Liu, Kelly Y.; MacAulay, Calum E.; Ng, Samson; Poh, Catherine F.; Lane, Pierre M.

    2017-02-01

    Worldwide, there are over 450,000 new cases of oral cancer reported each year. Late-stage diagnosis remains a significant factor responsible for its high mortality rate (>50%). In-vivo non-invasive rapid imaging techniques, that can visualise clinically significant changes in the oral mucosa, may improve the management of oral cancer. We present an analysis of features extracted from oral images obtained using our hand- held wide-field Optical Coherence Tomography (OCT) instrument. The images were analyzed for epithelial scattering, overall tissue scattering, and 3D basement membrane topology. The associations between these three features and disease state (benign, pre-cancer, or cancer), as measured by clinical assessment or pathology, were determined. While scattering coefficient has previously been shown to be sensitive to cancer and dysplasia, likely due to changes in nuclear and cellular density, the addition of basement membrane topology may increase diagnostic ability- as it is known that the presence of bulbous rete pegs in the basement membrane are characteristic of dysplasia. The resolution and field-of-view of our oral OCT system allowed analysis of these features over large areas of up to 2.5mm x 90mm, in a timely fashion, which allow for application in clinical settings.

  13. A low-noise wide dynamic range CMOS image sensor with low and high temperatures resistance

    Science.gov (United States)

    Mizobuchi, Koichi; Adachi, Satoru; Tejada, Jose; Oshikubo, Hiromichi; Akahane, Nana; Sugawa, Shigetoshi

    2008-02-01

    A temperature-resistant 1/3 inch SVGA (800×600 pixels) 5.6 μm pixel pitch wide-dynamic-range (WDR) CMOS image sensor has been developed using a lateral-over-flow-integration-capacitor (LOFIC) in a pixel. The sensor chips are fabricated through 0.18 μm 2P3M process with totally optimized front-end-of-line (FEOL) & back-end-of-line (BEOL) for a lower dark current. By implementing a low electrical field potential design for photodiodes, reducing damages, recovering crystal defects and terminating interface states in the FEOL+BEOL, the dark current is improved to 12 e - /pixel-sec at 60 deg.C with 50% reduction from the previous very-low-dark-current (VLDC) FEOL and its contribution to the temporal noise is improved. Furthermore, design optimizations of the readout circuits, especially a signal-and noise-hold circuit and a programmable-gain-amplifier (PGA) are also implemented. The measured temporal noise is 2.4 e -rms at 60 fps (:36 MHz operation). The dynamic-range (DR) is extended to 100 dB with 237 ke - full well capacity. In order to secure the temperature-resistance, the sensor chip also receives both an inorganic cap onto micro lens and a metal hermetic seal package assembly. Image samples at low & high temperatures show significant improvement in image qualities.

  14. Dosimetric impact of image artifact from a wide-bore CT scanner in radiotherapy treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Vincent; Podgorsak, Matthew B.; Tran, Tuan-Anh; Malhotra, Harish K.; Wang, Iris Z. [Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263 (United States); Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263 and Department of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, New York 14214 (United States); Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263 (United States); Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263 and Department of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, New York 14214 (United States)

    2011-07-15

    Purpose: Traditional computed tomography (CT) units provide a maximum scan field-of-view (sFOV) diameter of 50 cm and a limited bore size, which cannot accommodate a large patient habitus or an extended simulation setup in radiation therapy (RT). Wide-bore CT scanners with increased bore size were developed to address these needs. Some scanners have the capacity to reconstruct the CT images at an extended FOV (eFOV), through data interpolation or extrapolation, using projection data acquired with a conventional sFOV. Objects that extend past the sFOV for eFOV reconstruction may generate image artifacts resulting from truncated projection data; this may distort CT numbers and structure contours in the region beyond the sFOV. The purpose of this study was to evaluate the dosimetric impact of image artifacts from eFOV reconstruction with a wide-bore CT scanner in radiotherapy (RT) treatment planning. Methods: Testing phantoms (i.e., a mini CT phantom with equivalent tissue inserts, a set of CT normal phantoms and anthropomorphic phantoms of the thorax and the pelvis) were used to evaluate eFOV artifacts. Reference baseline images of these phantoms were acquired with the phantom centrally positioned within the sFOV. For comparison, the phantoms were then shifted laterally and scanned partially outside the sFOV, but still within the eFOV. Treatment plans were generated for the thoracic and pelvic anthropomorphic phantoms utilizing the Eclipse treatment planning system (TPS) to study the potential effects of eFOV artifacts on dose calculations. All dose calculations of baseline and test treatment plans were carried out using the same MU. Results: Results show that both body contour and CT numbers are altered by image artifacts in eFOV reconstruction. CT number distortions of up to -356 HU for bone tissue and up to 323 HU for lung tissue were observed in the mini CT phantom. Results from the large body normal phantom, which is close to a clinical patient size, show

  15. Wide-field microscopic FRET imaging using simultaneous spectral unmixing of excitation and emission spectra.

    Science.gov (United States)

    Du, Mengyan; Zhang, Lili; Xie, Shusen; Chen, Tongsheng

    2016-07-11

    Simultaneous spectral unmixing of excitation and emission spectra (ExEm unmixing) has the inherent ability to resolve donor emission, fluorescence resonance energy transfer (FRET)-sensitized acceptor emission and directly excited acceptor emission. We here develop an ExEm unmixing-based quantitative FRET measurement method (EES-FRET) independent of excitation intensity and detector parameter setting. The ratio factor (rK), predetermined using a donor-acceptor tandem construct, of total acceptor absorption to total donor absorption in excitation wavelengths used is introduced for determining the concentration ratio of acceptor to donor. We implemented EES-FRET method on a wide-field microscope to image living cells expressing tandem FRET constructs with different donor-acceptor stoichiometry.

  16. Homography Propagation and Optimization for Wide-Baseline Street Image Interpolation.

    Science.gov (United States)

    Nie, Yongwei; Zhang, Zhensong; Sun, Hanqiu; Su, Tan; Li, Guiqing

    2017-10-01

    Wide-baseline street image interpolation is useful but very challenging. Existing approaches either rely on heavyweight 3D reconstruction or computationally intensive deep networks. We present a lightweight and efficient method which uses simple homography computing and refining operators to estimate piecewise smooth homographies between input views. To achieve the goal, we show how to combine homography fitting and homography propagation together based on reliable and unreliable superpixel discrimination. Such a combination, other than using homography fitting only, dramatically increases the accuracy and robustness of the estimated homographies. Then, we integrate the concepts of homography and mesh warping, and propose a novel homography-constrained warping formulation which enforces smoothness between neighboring homographies by utilizing the first-order continuity of the warped mesh. This further eliminates small artifacts of overlapping, stretching, etc. The proposed method is lightweight and flexible, allows wide-baseline interpolation. It improves the state of the art and demonstrates that homography computation suffices for interpolation. Experiments on city and rural datasets validate the efficiency and effectiveness of our method.

  17. Wide-Field Imaging Telescope-0 (WIT0) with automatic observing system

    Science.gov (United States)

    Ji, Tae-Geun; Byeon, Seoyeon; Lee, Hye-In; Park, Woojin; Lee, Sang-Yun; Hwang, Sungyong; Choi, Changsu; Gibson, Coyne Andrew; Kuehne, John W.; Prochaska, Travis; Marshall, Jennifer L.; Im, Myungshin; Pak, Soojong

    2018-01-01

    We introduce Wide-Field Imaging Telescope-0 (WIT0), with an automatic observing system. It is developed for monitoring the variabilities of many sources at a time, e.g. young stellar objects and active galactic nuclei. It can also find the locations of transient sources such as a supernova or gamma-ray bursts. In 2017 February, we installed the wide-field 10-inch telescope (Takahashi CCA-250) as a piggyback system on the 30-inch telescope at the McDonald Observatory in Texas, US. The 10-inch telescope has a 2.35 × 2.35 deg field-of-view with a 4k × 4k CCD Camera (FLI ML16803). To improve the observational efficiency of the system, we developed a new automatic observing software, KAOS30 (KHU Automatic Observing Software for McDonald 30-inch telescope), which was developed by Visual C++ on the basis of a windows operating system. The software consists of four control packages: the Telescope Control Package (TCP), the Data Acquisition Package (DAP), the Auto Focus Package (AFP), and the Script Mode Package (SMP). Since it also supports the instruments that are using the ASCOM driver, the additional hardware installations become quite simplified. We commissioned KAOS30 in 2017 August and are in the process of testing. Based on the WIT0 experiences, we will extend KAOS30 to control multiple telescopes in future projects.

  18. Clustering phenotype populations by genome-wide RNAi and multiparametric imaging

    Science.gov (United States)

    Fuchs, Florian; Pau, Gregoire; Kranz, Dominique; Sklyar, Oleg; Budjan, Christoph; Steinbrink, Sandra; Horn, Thomas; Pedal, Angelika; Huber, Wolfgang; Boutros, Michael

    2010-01-01

    Genetic screens for phenotypic similarity have made key contributions to associating genes with biological processes. With RNA interference (RNAi), highly parallel phenotyping of loss-of-function effects in cells has become feasible. One of the current challenges however is the computational categorization of visual phenotypes and the prediction of biological function and processes. In this study, we describe a combined computational and experimental approach to discover novel gene functions and explore functional relationships. We performed a genome-wide RNAi screen in human cells and used quantitative descriptors derived from high-throughput imaging to generate multiparametric phenotypic profiles. We show that profiles predicted functions of genes by phenotypic similarity. Specifically, we examined several candidates including the largely uncharacterized gene DONSON, which shared phenotype similarity with known factors of DNA damage response (DDR) and genomic integrity. Experimental evidence supports that DONSON is a novel centrosomal protein required for DDR signalling and genomic integrity. Multiparametric phenotyping by automated imaging and computational annotation is a powerful method for functional discovery and mapping the landscape of phenotypic responses to cellular perturbations. PMID:20531400

  19. Wide-field time-resolved luminescence imaging and spectroscopy to decipher obliterated documents in forensic science

    Science.gov (United States)

    Suzuki, Mototsugu; Akiba, Norimitsu; Kurosawa, Kenji; Kuroki, Kenro; Akao, Yoshinori; Higashikawa, Yoshiyasu

    2016-01-01

    We applied a wide-field time-resolved luminescence (TRL) method with a pulsed laser and a gated intensified charge coupled device (ICCD) for deciphering obliterated documents for use in forensic science. The TRL method can nondestructively measure the dynamics of luminescence, including fluorescence and phosphorescence lifetimes, which prove to be useful parameters for image detection. First, we measured the TRL spectra of four brands of black porous-tip pen inks on paper to estimate their luminescence lifetimes. Next, we acquired the TRL images of 12 obliterated documents at various delay times and gate times of the ICCD. The obliterated contents were revealed in the TRL images because of the difference in the luminescence lifetimes of the inks. This method requires no pretreatment, is nondestructive, and has the advantage of wide-field imaging, which makes it is easy to control the gate timing. This demonstration proves that TRL imaging and spectroscopy are powerful tools for forensic document examination.

  20. Evaluation of illumination system uniformity for wide-field biomedical hyperspectral imaging

    Science.gov (United States)

    Sawyer, Travis W.; Siri Luthman, A.; E Bohndiek, Sarah

    2017-04-01

    Hyperspectral imaging (HSI) systems collect both spatial (morphological) and spectral (chemical) information from a sample. HSI can provide sensitive analysis for biological and medical applications, for example, simultaneously measuring reflectance and fluorescence properties of a tissue, which together with structural information could improve early cancer detection and tumour characterisation. Illumination uniformity is a critical pre-condition for quantitative data extraction from an HSI system. Non-uniformity can cause glare, specular reflection and unwanted shading, which negatively impact statistical analysis procedures used to extract abundance of different chemical species. Here, we model and evaluate several illumination systems frequently used in wide-field biomedical imaging to test their potential for HSI. We use the software LightTools and FRED. The analysed systems include: a fibre ring light; a light emitting diode (LED) ring; and a diffuse scattering dome. Each system is characterised for spectral, spatial, and angular uniformity, as well as transfer efficiency. Furthermore, an approach to measure uniformity using the Kullback-Leibler divergence (KLD) is introduced. The KLD is generalisable to arbitrary illumination shapes, making it an attractive approach for characterising illumination distributions. Although the systems are quite comparable in their spatial and spectral uniformity, the most uniform angular distribution is achieved using a diffuse scattering dome, yielding a contrast of 0.503 and average deviation of 0.303 over a ±60° field of view with a 3.9% model error in the angular domain. Our results suggest that conventional illumination sources can be applied in HSI, but in the case of low light levels, bespoke illumination sources may offer improved performance.

  1. Wide field imaging - I. Applications of neural networks to object detection and star/galaxy classification

    Science.gov (United States)

    Andreon, S.; Gargiulo, G.; Longo, G.; Tagliaferri, R.; Capuano, N.

    2000-12-01

    Astronomical wide-field imaging performed with new large-format CCD detectors poses data reduction problems of unprecedented scale, which are difficult to deal with using traditional interactive tools. We present here NExt (Neural Extractor), a new neural network (NN) based package capable of detecting objects and performing both deblending and star/galaxy classification in an automatic way. Traditionally, in astronomical images, objects are first distinguished from the noisy background by searching for sets of connected pixels having brightnesses above a given threshold; they are then classified as stars or as galaxies through diagnostic diagrams having variables chosen according to the astronomer's taste and experience. In the extraction step, assuming that images are well sampled, NExt requires only the simplest a priori definition of `what an object is' (i.e. it keeps all structures composed of more than one pixel) and performs the detection via an unsupervised NN, approaching detection as a clustering problem that has been thoroughly studied in the artificial intelligence literature. The first part of the NExt procedure consists of an optimal compression of the redundant information contained in the pixels via a mapping from pixel intensities to a subspace individualized through principal component analysis. At magnitudes fainter than the completeness limit, stars are usually almost indistinguishable from galaxies, and therefore the parameters characterizing the two classes do not lie in disconnected subspaces, thus preventing the use of unsupervised methods. We therefore adopted a supervised NN (i.e. a NN that first finds the rules to classify objects from examples and then applies them to the whole data set). In practice, each object is classified depending on its membership of the regions mapping the input feature space in the training set. In order to obtain an objective and reliable classification, instead of using an arbitrarily defined set of features

  2. Body-wide hierarchical fuzzy modeling, recognition, and delineation of anatomy in medical images.

    Science.gov (United States)

    Udupa, Jayaram K; Odhner, Dewey; Zhao, Liming; Tong, Yubing; Matsumoto, Monica M S; Ciesielski, Krzysztof C; Falcao, Alexandre X; Vaideeswaran, Pavithra; Ciesielski, Victoria; Saboury, Babak; Mohammadianrasanani, Syedmehrdad; Sin, Sanghun; Arens, Raanan; Torigian, Drew A

    2014-07-01

    To make Quantitative Radiology (QR) a reality in radiological practice, computerized body-wide Automatic Anatomy Recognition (AAR) becomes essential. With the goal of building a general AAR system that is not tied to any specific organ system, body region, or image modality, this paper presents an AAR methodology for localizing and delineating all major organs in different body regions based on fuzzy modeling ideas and a tight integration of fuzzy models with an Iterative Relative Fuzzy Connectedness (IRFC) delineation algorithm. The methodology consists of five main steps: (a) gathering image data for both building models and testing the AAR algorithms from patient image sets existing in our health system; (b) formulating precise definitions of each body region and organ and delineating them following these definitions; (c) building hierarchical fuzzy anatomy models of organs for each body region; (d) recognizing and locating organs in given images by employing the hierarchical models; and (e) delineating the organs following the hierarchy. In Step (c), we explicitly encode object size and positional relationships into the hierarchy and subsequently exploit this information in object recognition in Step (d) and delineation in Step (e). Modality-independent and dependent aspects are carefully separated in model encoding. At the model building stage, a learning process is carried out for rehearsing an optimal threshold-based object recognition method. The recognition process in Step (d) starts from large, well-defined objects and proceeds down the hierarchy in a global to local manner. A fuzzy model-based version of the IRFC algorithm is created by naturally integrating the fuzzy model constraints into the delineation algorithm. The AAR system is tested on three body regions - thorax (on CT), abdomen (on CT and MRI), and neck (on MRI and CT) - involving a total of over 35 organs and 130 data sets (the total used for model building and testing). The training and

  3. Wide field imaging spectrometer for ESA's future X-ray mission: XEUS

    CERN Document Server

    Strüder, L

    1999-01-01

    An active pixel sensor (APS) based on the DEpleted P-channel junction Field Effect Transistor (DEPFET) concept will be described as a potential wide field imager for ESA's high resolution, high throughput mission: 'X-ray Evolving Universe Spectroscopy' (XEUS). It comprises a parallel multichannel readout, low noise at high speed readout, backside illumination and a fill factor of 100% over the whole field of view. The depleted thickness will be 500 microns. These design parameters match the scientific requirements of the mission. The fabrication techniques of the DEPFET arrays are related to the high resistivity process of the X-ray pn-CCDs. Potential extensions of the already realized DEPFET structures are a non-destructive repetitive readout of the signal charges. This concept will be presented. As an alternative solution, frame store pn-CCDs are considered having the same format and pixel sizes as the proposed DEPFET arrays. Their development is a low risk, straightforward continuation of the XMM devices. ...

  4. Studies of prototype DEPFET sensors for the Wide Field Imager of Athena

    Science.gov (United States)

    Treberspurg, Wolfgang; Andritschke, Robert; Bähr, Alexander; Behrens, Annika; Hauser, Günter; Lechner, Peter; Meidinger, Norbert; Müller-Seidlitz, Johannes; Treis, Johannes

    2017-08-01

    The Wide Field Imager (WFI) of ESA's next X-ray observatory Athena will combine a high count rate capability with a large field of view, both with state-of-the-art spectroscopic performance. To meet these demands, specific DEPFET active pixel detectors have been developed and operated. Due to the intrinsic amplification of detected signals they are best suited to achieve a high speed and low noise performance. Different fabrication technologies and transistor geometries have been implemented on a dedicated prototype production in the course of the development of the DEPFET sensors. The main modifications between the sensors concern the shape of the transistor gate - regarding the layout - and the thickness of the gate oxide - regarding the technology. To facilitate the fabrication and testing of the resulting variety of sensors the presented studies were carried out with 64×64 pixel detectors. The detector comprises a control ASIC (Switcher-A), a readout ASIC (VERITAS- 2) and the sensor. In this paper we give an overview on the evaluation of different prototype sensors. The most important results, which have been decisive for the identification of the optimal fabrication technology and transistor layout for subsequent sensor productions are summarized. It will be shown that the developments result in an excellent performance of spectroscopic X-ray DEPFETs with typical noise values below 2.5 ENC at 2.5 μs/row.

  5. Lensfree Fluorescent On-Chip Imaging of Transgenic Caenorhabditis elegans Over an Ultra-Wide Field-of-View

    Science.gov (United States)

    Ozcan, Aydogan

    2011-01-01

    We demonstrate lensfree on-chip fluorescent imaging of transgenic Caenorhabditis elegans (C. elegans) over an ultra-wide field-of-view (FOV) of e.g., >2–8 cm2 with a spatial resolution of ∼10µm. This is the first time that a lensfree on-chip platform has successfully imaged fluorescent C. elegans samples. In our wide-field lensfree imaging platform, the transgenic samples are excited using a prism interface from the side, where the pump light is rejected through total internal reflection occurring at the bottom facet of the substrate. The emitted fluorescent signal from C. elegans samples is then recorded on a large area opto-electronic sensor-array over an FOV of e.g., >2–8 cm2, without the use of any lenses, thin-film interference filters or mechanical scanners. Because fluorescent emission rapidly diverges, such lensfree fluorescent images recorded on a chip look blurred due to broad point-spread-function of our platform. To combat this resolution challenge, we use a compressive sampling algorithm to uniquely decode the recorded lensfree fluorescent patterns into higher resolution images, demonstrating ∼10 µm resolution. We tested the efficacy of this compressive decoding approach with different types of opto-electronic sensors to achieve a similar resolution level, independent of the imaging chip. We further demonstrate that this wide FOV lensfree fluorescent imaging platform can also perform sequential bright-field imaging of the same samples using partially-coherent lensfree digital in-line holography that is coupled from the top facet of the same prism used in fluorescent excitation. This unique combination permits ultra-wide field dual-mode imaging of C. elegans on a chip which could especially provide a useful tool for high-throughput screening applications in biomedical research. PMID:21253611

  6. Wide field imager instrument for the Advanced Telescope for High Energy Astrophysics

    Science.gov (United States)

    Meidinger, Norbert; Nandra, Kirpal; Plattner, Markus; Porro, Matteo; Rau, Arne; Santangelo, Andrea; Tenzer, Chris; Wilms, Jörn

    2015-01-01

    The Advanced Telescope for High Energy Astrophysics (Athena) has been selected for ESA's L2 mission, scheduled for launch in 2028. It will provide the necessary capabilities to achieve the ambitious goals of the science theme "The Hot and Energetic Universe." Athena's x-ray mirrors will be based on silicon pore optics technology with a 12-m focal length. Two complementary focal plane camera systems are foreseen, which can be moved interchangeably to the focus of the mirror system: the actively shielded micro-calorimeter spectrometer X-IFU and the wide field imager (WFI). The WFI camera will provide an unprecedented survey power through its large field of view of 40 arc min with a high count-rate capability (˜1 Crab). It permits a state-of-the-art energy resolution in the energy band of 0.1 to 15 keV during the entire mission lifetime (e.g., full width at half maximum ≤150 eV at 6 keV). This performance is accomplished by a set of depleted P-channel field effect transistor (DEPFET) active pixel sensor matrices with a pixel size well suited to the angular resolution of 5 arc sec (on-axis) of the mirror system. Each DEPFET pixel is a combined detector-amplifier structure with a MOSFET integrated onto a fully depleted 450-μm-thick silicon bulk. This manuscript will summarize the current instrument concept and design, the status of the technology development, and the envisaged baseline performance.

  7. Rapid wide-field Mueller matrix polarimetry imaging based on four photoelastic modulators with no moving parts.

    Science.gov (United States)

    Alali, Sanaz; Gribble, Adam; Vitkin, I Alex

    2016-03-01

    A new polarimetry method is demonstrated to image the entire Mueller matrix of a turbid sample using four photoelastic modulators (PEMs) and a charge coupled device (CCD) camera, with no moving parts. Accurate wide-field imaging is enabled with a field-programmable gate array (FPGA) optical gating technique and an evolutionary algorithm (EA) that optimizes imaging times. This technique accurately and rapidly measured the Mueller matrices of air, polarization elements, and turbid phantoms. The system should prove advantageous for Mueller matrix analysis of turbid samples (e.g., biological tissues) over large fields of view, in less than a second.

  8. Comparison of multispectral wide-field optical imaging modalities to maximize image contrast for objective discrimination of oral neoplasia

    Science.gov (United States)

    Roblyer, Darren; Kurachi, Cristina; Stepanek, Vanda; Schwarz, Richard A.; Williams, Michelle D.; El-Naggar, Adel K.; Lee, J. Jack; Gillenwater, Ann M.; Richards-Kortum, Rebecca

    2010-11-01

    Multispectral widefield optical imaging has the potential to improve early detection of oral cancer. The appropriate selection of illumination and collection conditions is required to maximize diagnostic ability. The goals of this study were to (i) evaluate image contrast between oral cancer/precancer and non-neoplastic mucosa for a variety of imaging modalities and illumination/collection conditions, and (ii) use classification algorithms to evaluate and compare the diagnostic utility of these modalities to discriminate cancers and precancers from normal tissue. Narrowband reflectance, autofluorescence, and polarized reflectance images were obtained from 61 patients and 11 normal volunteers. Image contrast was compared to identify modalities and conditions yielding greatest contrast. Image features were extracted and used to train and evaluate classification algorithms to discriminate tissue as non-neoplastic, dysplastic, or cancer; results were compared to histologic diagnosis. Autofluorescence imaging at 405-nm excitation provided the greatest image contrast, and the ratio of red-to-green fluorescence intensity computed from these images provided the best classification of dysplasia/cancer versus non-neoplastic tissue. A sensitivity of 100% and a specificity of 85% were achieved in the validation set. Multispectral widefield images can accurately distinguish neoplastic and non-neoplastic tissue; however, the ability to separate precancerous lesions from cancers with this technique was limited.

  9. A K-Band Low-Power Phase Shifter Based on Injection Locked Oscillator in 0.13 μm CMOS Technology

    Science.gov (United States)

    Qiu, Qi-Lin; Yu, Xiao-Peng; Sui, Wen-Quan

    2017-11-01

    In this paper, the design challenges of the injection-locked oscillator (ILO)-based phase shifter are reviewed and analyzed. The key design considerations such as the operating frequency, locking range, and linearity of the phase shifters are analysed in detail. It is possible to optimize the phase shifter in certain parameters such as ultra-low power while meeting the requirements of a certain system. As a design example, a K-band phase shifter is implemented using a commercial 0.13 μm CMOS technology, where a conventional LC tank based topology is implemented but optimised with a good balance among power consumption, working range, sensitivity, and silicon area, etc. Measurement results show that the proposed phase shift is able to work at 22-23.4 GHz with a range of 180∘ while consuming 3.14 mW from a 1.2 V supply voltage.

  10. Singapore National Medical Image Resource Centre (SN.MIRC): a world wide web resource for radiology education.

    Science.gov (United States)

    Yang, Guo-Liang; Lim, C C Tchoyoson

    2006-08-01

    Radiology education is heavily dependent on visual images, and case-based teaching files comprising medical images can be an important tool for teaching diagnostic radiology. Currently, hardcopy film is being rapidly replaced by digital radiological images in teaching hospitals, and an electronic teaching file (ETF) library would be desirable. Furthermore, a repository of ETFs deployed on the World Wide Web has the potential for e-learning applications to benefit a larger community of learners. In this paper, we describe a Singapore National Medical Image Resource Centre (SN.MIRC) that can serve as a World Wide Web resource for teaching diagnostic radiology. On SN.MIRC, ETFs can be created using a variety of mechanisms including file upload and online form-filling, and users can search for cases using the Medical Image Resource Center (MIRC) query schema developed by the Radiological Society of North America (RSNA). The system can be improved with future enhancements, including multimedia interactive teaching files and distance learning for continuing professional development. However, significant challenges exist when exploring the potential of using the World Wide Web for radiology education.

  11. The Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS) NASA Mission-of- Opportunity - Up and Operational

    Science.gov (United States)

    McComas*, D. J.

    2008-12-01

    *Presented on behalf of the entire TWINS Team Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS) is a NASA Explorer Mission-of-Opportunity to stereoscopically image the Earth's magnetosphere for the first time [McComas et al., 2008]. TWINS extends our understanding of magnetospheric structure and processes by providing simultaneous Energetic Neutral Atom (ENA) imaging from two widely separated locations. TWINS observes ENAs from 1-100 keV with high angular (~4° x 4°) and time (~1-minute) resolution. The TWINS Ly-α monitor measures the geocoronal hydrogen density to aid in ENA analysis while environmental sensors provide contemporaneous measurements of the local charged particle environments. By imaging ENAs with identical instruments from two widely spaced, high-altitude, high-inclination spacecraft, TWINS enables three-dimensional visualization of the large-scale structures and dynamics within the magnetosphere for the first time. As of the summer of 2008, both TWINS instruments are finally on orbit and operational and stereo imaging of the magnetosphere has begun. This talk briefly summarizes the TWINS mission and instruments and shows some of the 'first-light' observations. More information about TWINS and access to these data are available at http://twins.swri.edu. Reference: McComas, D.J., F. Allegrini, J. Baldonado, B. Blake, P. C. Brandt, J. Burch, J. Clemmons, W. Crain, D. Delapp, R. DeMajistre, D. Everett, H. Fahr, L. Friesen, H. Funsten, J. Goldstein, M. Gruntman, R. Harbaugh, R. Harper, H. Henkel, C. Holmlund, G. Lay, D. Mabry, D. Mitchell, U. Nass, C. Pollock, S. Pope, M. Reno, S. Ritzau, E. Roelof, E. Scime, M. Sivjee, R. Skoug, T. S. Sotirelis, M. Thomsen, C. Urdiales, P. Valek, K. Viherkanto, S. Weidner, T. Ylikorpi, M. Young, J. Zoennchen, The Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS) NASA Mission-of-Opportunity, Submitted to Space Science Reviews, 2008.

  12. The Initial Configuration of Young Stellar Clusters: A K-Band Number Counts Analysis of the Surface Density of Stars

    Science.gov (United States)

    Gutermuth, Robert A.; Megeath, S. Thomas; Pipher, Judith L.; Williams, Jonathan P.; Allen, Lori E.; Myers, Philip C.; Raines, S. Nicholas

    2005-10-01

    We present an analysis of stellar distributions for the young stellar clusters GGD 12-15, IRAS 20050+2720, and NGC 7129, which range in far-IR luminosity from 227 to 5.68×103 Lsolar and are all still associated with their natal molecular clouds. The data used for this analysis include near-IR data obtained with FLAMINGOS on the MMT and newly obtained wide-field 850 μm emission maps from SCUBA on the JCMT. Cluster size and azimuthal asymmetry are measured via azimuthal and radial averaging methods, respectively. To quantify the deviation of the distribution of stars from circular symmetry, we define an azimuthal asymmetry parameter, and we investigate the statistical properties of this parameter through Monte Carlo simulations. The distribution of young stars is compared to the morphology of the molecular gas using stellar surface density maps and the 850 μm maps. We find that two of the clusters are not azimuthally symmetric and show a high degree of structure. The GGD 12-15 cluster is elongated and is aligned with newly detected filamentary structure at 850 μm. IRAS 20050+2720 is composed of a chain of three subclusters, in agreement with Chen and coworkers, although our results show that two of the subclusters appear to overlap. Significant 850 μm emission is detected toward two of the subclusters but is not detected toward the central subcluster, suggesting that the dense gas may already be cleared there. In contrast to these two highly embedded subclusters, we find an anticorrelation of the stars and dust in NGC 7129, indicating that much of the parental gas and dust has been dispersed. The NGC 7129 cluster exhibits a higher degree of azimuthal symmetry, a lower stellar surface density, and a larger size than the other two clusters, suggesting that the cluster may be dynamically expanding following the recent dispersal of natal molecular gas. These analyses are further evidence that embedded, forming clusters are often not spherically symmetric structures

  13. Image Centroid Algorithms for Sun Sensors with Super Wide Field of View

    Directory of Open Access Journals (Sweden)

    ZHAN Yinhu

    2015-10-01

    Full Text Available Sun image centroid algorithm is one of the key technologies of celestial navigation using sun sensors, which directly determine the precision of the sensors. Due to the limitation of centroid algorithm for non-circular sun image of the sun sensor of large field of view, firstly, the ellipse fitting algorithm is proposed for solving elliptical or sub-elliptical sun images. Then the spherical circle fitting algorithm is put forward. Based on the projection model and distortion model of the camera, the spherical circle fitting algorithm is used to obtain the edge points of the sun in the object space, and then the centroid of the sun can be determined by fitting the edge points as a spherical circle. In order to estimate the precision of spherical circle fitting algorithm, the centroid of the sun should be projected back to the image space. Theoretically, the spherical circle fitting algorithm is no longer need to take into account the shape of the sun image, the algorithm is more precise. The results of practical sun images demonstrate that the ellipse fitting algorithm is more suitable for the sun image with 70°~80.3° half angle of view, and the mean precision is about 0.075 pixels; the spherical circle fitting algorithm is more suitable for the sun image with a half angle of view larger than 80.3°, and the mean precision is about 0.082 pixels.

  14. Compressive hyperspectral time-resolved wide-field fluorescence lifetime imaging

    Science.gov (United States)

    Pian, Qi; Yao, Ruoyang; Sinsuebphon, Nattawut; Intes, Xavier

    2017-07-01

    Spectrally resolved fluorescence lifetime imaging and spatial multiplexing have offered information content and collection-efficiency boosts in microscopy, but efficient implementations for macroscopic applications are still lacking. An imaging platform based on time-resolved structured light and hyperspectral single-pixel detection has been developed to perform quantitative macroscopic fluorescence lifetime imaging (MFLI) over a large field of view (FOV) and multiple spectral bands simultaneously. The system makes use of three digital micromirror device (DMD)-based spatial light modulators (SLMs) to generate spatial optical bases and reconstruct N by N images over 16 spectral channels with a time-resolved capability (∼40 ps temporal resolution) using fewer than N2 optical measurements. We demonstrate the potential of this new imaging platform by quantitatively imaging near-infrared (NIR) Förster resonance energy transfer (FRET) both in vitro and in vivo. The technique is well suited for quantitative hyperspectral lifetime imaging with a high sensitivity and paves the way for many important biomedical applications.

  15. Small Airborne Hyperspectral Wide Area Imager for Disaster Response and Earth Science Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed hyperspectral plus LWIR system will deliver high signal to noise performance, a wide spectral range, nominally 365 nm to 1.7 um, a single long wave IR...

  16. Microwave power imaging for ultra-wide band early breast cancer detection

    Science.gov (United States)

    Shao, Wenyi

    Due to the critical need for complementary or/and alternative modalities to current X-ray mammography for early-stage breast cancer detection, a 3D active microwave imaging system has been developed. This thesis presents a detailed method for rapid, high contrast microwave imaging for the purpose of breast survey. In the proposed imaging system, several transmitters polarized in different directions take turns sending out a low-power UWB pulse into the breast; backscattered signals are recorded by a synthetic aperture antenna array. These backscattered signals are passed through a beamformer, which spatially focuses the waveforms to image backscattered energy as a function of location in the breast. A simple Delay-and-Sum algorithm is applied to test the proposed multistatic multi-polarized detection scheme. The obtained 2-D and 3-D numerical results have demonstrated the feasibility and superiority of detecting small malignant breast tumors using our antenna strategy. An improved algorithm of microwave power imaging for detecting small breast tumors within an MRI-derived phantom is also introduced. Our imaging results demonstrate that a high-quality image can be reached without solving the inverse problem. To set up an experimental system for future clinical investigation, we developed two Vivaldi antennas, which have a notable broad band property, good radiation pattern, and a suitable size for breast cancer detection. Finally, an antenna array which consists of eight proposed Vivaldi antennas is introduced. By conveniently moving up/down and rotating this antenna array, it can be used for the multistatic breast cancer imaging and qualified for our multi-polarized scan mode.

  17. Wide-field flexible endoscope for simultaneous color and NIR fluorescence image acquisition during surveillance colonoscopy

    Science.gov (United States)

    García-Allende, P. Beatriz; Nagengast, Wouter B.; Glatz, Jürgen; Ntziachristos, Vasilis

    2013-03-01

    Colorectal cancer (CRC) is the third most common form of cancer and, despite recent declines in both incidence and mortality, it still remains the second leading cause of cancer-related deaths in the western world. Colonoscopy is the standard for detection and removal of premalignant lesions to prevent CRC. The major challenges that physicians face during surveillance colonoscopy are the high adenoma miss-rates and the lack of functional information to facilitate decision-making concerning which lesions to remove. Targeted imaging with NIR fluorescence would address these limitations. Tissue penetration is increased in the NIR range while the combination with targeted NIR fluorescent agents provides molecularly specific detection of cancer cells, i.e. a red-flag detection strategy that allows tumor imaging with optimal sensitivity and specificity. The development of a flexible endoscopic fluorescence imaging method that can be integrated with standard medical endoscopes and facilitates the clinical use of this potential is described in this work. A semi-disposable coherent fiber optic imaging bundle that is traditionally employed in the exploration of biliary and pancreatic ducts is proposed, since it is long and thin enough to be guided through the working channel of a traditional video colonoscope allowing visualization of proximal lesions in the colon. A custom developed zoom system magnifies the image of the proximal end of the imaging bundle to fill the dimensions of two cameras operating in parallel providing the simultaneous color and fluorescence video acquisition.

  18. Wide area coverage radar imaging satellite for earth applications. [surveillance and mapping of ice on Great Lakes

    Science.gov (United States)

    Stevens, G. H.; Ramler, J. R.

    1974-01-01

    A preliminary study was made of a radar imaging satellite for earth applications. A side-looking synthetic-aperture radar was considered and the feasibility of obtaining a wide area coverage to reduce the time required to image a given area was investigated. Two basic approaches were examined; low altitude sun-synchronous orbits using a multibeam/multifrequency radar system and equatorial orbits up to near-synchronous altitude using a single beam system. Surveillance and mapping of ice on the Great Lakes was used as a typical application to focus the study effort.

  19. Wide Field-of-View Fluorescence Imaging with Optical-Quality Curved Microfluidic Chamber for Absolute Cell Counting

    Directory of Open Access Journals (Sweden)

    Mohiuddin Khan Shourav

    2016-07-01

    Full Text Available Field curvature and other aberrations are encountered inevitably when designing a compact fluorescence imaging system with a simple lens. Although multiple lens elements can be used to correct most such aberrations, doing so increases system cost and complexity. Herein, we propose a wide field-of-view (FOV fluorescence imaging method with an unconventional optical-quality curved sample chamber that corrects the field curvature caused by a simple lens. Our optics simulations and proof-of-concept experiments demonstrate that a curved substrate with lens-dependent curvature can reduce greatly the distortion in an image taken with a conventional planar detector. Following the validation study, we designed a curved sample chamber that can contain a known amount of sample volume and fabricated it at reasonable cost using plastic injection molding. At a magnification factor of approximately 0.6, the curved chamber provides a clear view of approximately 119 mm2, which is approximately two times larger than the aberration-free area of a planar chamber. Remarkably, a fluorescence image of microbeads in the curved chamber exhibits almost uniform intensity over the entire field even with a simple lens imaging system, whereas the distorted boundary region has much lower brightness than the central area in the planar chamber. The absolute count of white blood cells stained with a fluorescence dye was in good agreement with that obtained by a commercially available conventional microscopy system. Hence, a wide FOV imaging system with the proposed curved sample chamber would enable us to acquire an undistorted image of a large sample volume without requiring a time-consuming scanning process in point-of-care diagnostic applications.

  20. Retinal changes detected by wide-field autofluorescence imaging of patients with primary rhegmatogenous retinal detachment

    DEFF Research Database (Denmark)

    Poulsen, Christina Døfler; Grauslund, Jakob; Peto, Tunde

    2014-01-01

    and 2 months follow-up and 59 had gradable images with characteristics studied in this part of the study. Exclusions were: poor images (n=8), major surgery or changes on fellow-eye (n=11), no baseline or 2-month image (n=7), re-detachment at 2-month follow-up (n=1) and eyes traumas (n=2). Retinal.......2 million inhabitants. Methods: A clinical prospective study of 99 eyes in 99 patients undergoing surgery for primary RRD between 1st of January 2013 and 12th of July 2013. All patients underwent surgery with pars plana vitrectomy (PPV) and had either gas or silicone oil tamponade. Patients were examined...... eye history (including cataract surgery), present symptoms, IOP, time from RRD to surgery, preoperative proliferative vitreoretinopathy (PVR) graded according to standardized protocol as follows: A (vitreous haze, pigment, vitreous cells and clumps) , B (wrinkling of inner retinal suface, vessel...

  1. VizieR Online Data Catalog: Wide field imagers ground-based astrometry. V. (Libralato+, 2014)

    Science.gov (United States)

    Libralato, M.; Bellini, A.; Bedin, L. R.; Piotto, G.; Platais, I.; Kissler-Patig, M.; Milone, A. P.

    2014-01-01

    Astro-photometric catalogs of 7 different fields. For each field we provide equatorial and pixel coordinates, infrared wide-band photometry. For NGC 6656 and NGC 6121 we also provide proper motions and an estimate of the membership probability. (11 data files).

  2. "Adam Smith Meets Walt Disney": School Image on the World Wide Web

    Science.gov (United States)

    Smith, Alison

    2007-01-01

    This article describes a small-scale research project undertaken as part of the coursework in a Doctor of Education programme. The project investigated the organisational images or identities portrayed by ten secondary schools in Auckland, New Zealand on their school websites. The recent proliferation of school websites has provided schools with a…

  3. Wide-band IR imaging in the NIR-MIR-FIR regions for in situ analysis of frescoes

    Science.gov (United States)

    Daffara, C.; Pezzati, L.; Ambrosini, D.; Paoletti, D.; Di Biase, R.; Mariotti, P. I.; Frosinini, C.

    2011-06-01

    Imaging methods offer several advantages in the field of conservation allowing to perform non-invasive inspection of works of art. In particular, non-invasive techniques based on imaging in different infrared (IR) regions are widely used for the investigation of paintings. Using radiation beyond the visible range, different characteristics of the inspected artwork may be revealed according to the bandwidth acquired. In this paper we present the recent results of a joint project among the two research institutes DIMEG and CNR-INO, and the restoration facility Opificio delle Pietre Dure, concerning the wide-band integration of IR imaging techniques, in the spectral ranges NIR 0.8-2.5 μm, MIR 3-5 μm, and FIR 8-12 μm, for in situ analysis of artworks. A joint, multi-mode use of reflection and thermal bands is proposed for the diagnostics of mural paintings, and it is demonstrated to be an effective tool in inspecting the layered structure. High resolution IR reflectography and, to a greater extent, IR imaging in the 3-5 μm band, are effectively used to characterize the superficial layer of the fresco and to analyze the stratigraphy of different pictorial layers. IR thermography in the 8-12 μm band is used to characterize the support deep structure. The integration of all the data provides a multi- layered and multi-spectral representation of the fresco that yields a comprehensive analysis.

  4. Miniature spectral imaging device for wide-field quantitative functional imaging of the morphological landscape of breast tumor margins

    Science.gov (United States)

    Nichols, Brandon S.; Llopis, Antonio; Palmer, Gregory M.; McCachren, Samuel S., III; Senlik, Ozlem; Miller, David; Brooke, Martin A.; Jokerst, Nan M.; Geradts, Joseph; Greenup, Rachel; Ramanujam, Nimmi

    2017-02-01

    We have developed a portable, breast margin assessment probe leveraging diffuse optical spectroscopy to quantify the morphological landscape of breast tumor margins during breast conserving surgery. The approach presented here leverages a custom-made 16-channel annular photodiode imaging array (arranged in a 4×4 grid), a raster-scanning imaging platform with precision pressure control, and compressive sensing with an optimized set of eight wavelengths in the visible spectral range. A scalable Monte-Carlo-based inverse model is used to generate optical property [μs‧(λ) and μa(λ)] measures for each of the 16 simultaneously captured diffuse reflectance spectra. Subpixel sampling (0.75 mm) is achieved through incremental x, y raster scanning of the imaging probe, providing detailed optical parameter maps of breast margins over a 2×2 cm2 area in ˜9 min. The morphological landscape of a tumor margin is characterized using optical surrogates for the fat to fibroglandular content ratio, which has demonstrated diagnostic utility in delineating tissue subtypes in the breast.

  5. Optically sectioned wide-field fluorescence lifetime imaging microscopy enabled by structured illumination

    Science.gov (United States)

    Hinsdale, Taylor; Olsovsky, Cory; Rico-Jimenez, Jose J.; Maitland, Kristen C.; Jo, Javier A.; Malik, Bilal H.

    2017-01-01

    In this paper, we demonstrate the ability of structured illumination microscopy to enhance the ability of fluorescence lifetime imaging to resolve fluorescence lifetimes in relatively thick samples that possess distinct but spectrally overlapping fluorescent layers. Structured illumination fluorescent lifetime imaging microscopy (SI-FLIM) is shown to be able to accurately reconstruct lifetime values in homogenous fluorophore samples (POPOP, NADH, and FAD) as well as accurately measure fluorescent lifetime in two layer models that are layered with NADH/FAD over POPOP, where NADH/FAD and POPOP have spectral overlap. Finally, the ability of SI-FLIM was demonstrated in a hamster cheek pouch ex vivo to show that more accurate lifetimes could be measured for each layer of interest in the oral mucosa (epithelium and submucosa). PMID:28663841

  6. World Wide Web platform-independent access to biomedical text/image databases

    Science.gov (United States)

    Long, L. Rodney; Goh, Gin-Hua; Neve, Leif; Thoma, George R.

    1998-07-01

    The biomedical digital library of the future is expected to provide access to stores of biomedical database information containing text and images. Developing efficient methods for accessing such databases is a research effort at the Lister Hill National Center for Biomedical Communications of the National Library of Medicine. In this paper we examine issues in providing access to databases across the Web and describe a tool we have developed: the Web-based Medical Information Retrieval System (WebMIRS). We address a number of critical issues, including preservation of data integrity, efficient database design, access to documentation, quality of query and results interfaces, capability to export results to other software, and exploitation of multimedia data. WebMIRS is implemented as a Java applet that allows database access to text and to associated image data, without requiring any user software beyond a standard Web browser. The applet implementation allows WebMIRS to run on any hardware platform (such as PCs, the Macintosh, or Unix machines) which supports a Java-enabled Web browser, such as Netscape or Internet Explorer. WebMIRS is being tested on text/x-ray image databases created from the National Health and Nutrition Examination Surveys (NHANES) data collected by the National Center for Health Statistics.

  7. The Demographics and Properties of Wide-Orbit, Planetary-Mass Companions from PSF Fitting of Spitzer/IRAC Images

    Science.gov (United States)

    Martinez, Raquel; Kraus, Adam L.

    2017-06-01

    Over the past decade, a growing population of planetary-mass companions ( 100 AU) from their host stars, challenging existing models of both star and planet formation. It is unclear whether these systems represent the low-mass extreme of stellar binary formation or the high-mass and wide-orbit extreme of planet formation theories, as various proposed formation pathways inadequately explain the physical and orbital aspects of these systems. Even so, determining which scenario best reproduces the observed characteristics of the PMCs will come once a statistically robust sample of directly-imaged PMCs are found and studied.We are developing an automated pipeline to search for wide-orbit PMCs to young stars in Spitzer/IRAC images. A Markov Chain Monte Carlo (MCMC) algorithm is the backbone of our novel point spread function (PSF) subtraction routine that efficiently creates and subtracts χ2-minimizing instrumental PSFs, simultaneously measuring astrometry and infrared photometry of these systems across the four IRAC channels (3.6 μm, 4.5 μm, 5.8 μm, and 8 μm). In this work, we present the results of a Spitzer/IRAC archival imaging study of 11 young, low-mass (0.044-0.88 M⊙ K3.5-M7.5) stars known to have faint, low-mass companions in 3 nearby star-forming regions (Chameleon, Taurus, and Upper Scorpius). We characterize the systems found to have low-mass companions with non-zero [I1] - [I4] colors, potentially signifying the presence of a circum(sub?)stellar disk. Plans for future pipeline improvements and paths forward will also be discussed. Once this computational foundation is optimized, the stage is set to quickly scour the nearby star-forming regions already imaged by Spitzer, identify potential candidates for further characterization with ground- or space-based telescopes, and increase the number of widely-separated PMCs known.

  8. Wide-area mapping of resting state hemodynamic correlations at microvascular resolution with multi-contrast optical imaging (Conference Presentation)

    Science.gov (United States)

    Senarathna, Janaka; Hadjiabadi, Darian; Gil, Stacy; Thakor, Nitish V.; Pathak, Arvind P.

    2017-02-01

    Different brain regions exhibit complex information processing even at rest. Therefore, assessing temporal correlations between regions permits task-free visualization of their `resting state connectivity'. Although functional MRI (fMRI) is widely used for mapping resting state connectivity in the human brain, it is not well suited for `microvascular scale' imaging in rodents because of its limited spatial resolution. Moreover, co-registered cerebral blood flow (CBF) and total hemoglobin (HbT) data are often unavailable in conventional fMRI experiments. Therefore, we built a customized system that combines laser speckle contrast imaging (LSCI), intrinsic optical signal (IOS) imaging and fluorescence imaging (FI) to generate multi-contrast functional connectivity maps at a spatial resolution of 10 μm. This system comprised of three illumination sources: a 632 nm HeNe laser (for LSCI), a 570 nm ± 5 nm filtered white light source (for IOS), and a 473 nm blue laser (for FI), as well as a sensitive CCD camera operating at 10 frames per second for image acquisition. The acquired data enabled visualization of changes in resting state neurophysiology at microvascular spatial scales. Moreover, concurrent mapping of CBF and HbT-based temporal correlations enabled in vivo mapping of how resting brain regions were linked in terms of their hemodynamics. Additionally, we complemented this approach by exploiting the transit times of a fluorescent tracer (Dextran-FITC) to distinguish arterial from venous perfusion. Overall, we demonstrated the feasibility of wide area mapping of resting state connectivity at microvascular resolution and created a new toolbox for interrogating neurovascular function.

  9. SkICAT: A cataloging and analysis tool for wide field imaging surveys

    Science.gov (United States)

    Weir, N.; Fayyad, U. M.; Djorgovski, S. G.; Roden, J.

    1992-01-01

    We describe an integrated system, SkICAT (Sky Image Cataloging and Analysis Tool), for the automated reduction and analysis of the Palomar Observatory-ST ScI Digitized Sky Survey. The Survey will consist of the complete digitization of the photographic Second Palomar Observatory Sky Survey (POSS-II) in three bands, comprising nearly three Terabytes of pixel data. SkICAT applies a combination of existing packages, including FOCAS for basic image detection and measurement and SAS for database management, as well as custom software, to the task of managing this wealth of data. One of the most novel aspects of the system is its method of object classification. Using state-of-theart machine learning classification techniques (GID3* and O-BTree), we have developed a powerful method for automatically distinguishing point sources from non-point sources and artifacts, achieving comparably accurate discrimination a full magnitude fainter than in previous Schmidt plate surveys. The learning algorithms produce decision trees for classification by examining instances of objects classified by eye on both plate and higher quality CCD data. The same techniques will be applied to perform higher-level object classification (e.g., of galaxy morphology) in the near future. Another key feature of the system is the facility to integrate the catalogs from multiple plates (and portions thereof) to construct a single catalog of uniform calibration and quality down to the faintest limits of the survey. SkICAT also provides a variety of data analysis and exploration tools for the scientific utilization of the resulting catalogs. We include initial results of applying this system to measure the counts and distribution of galaxies in two bands down to Bj is approximately 21 mag over an approximate 70 square degree multi-plate field from POSS-II. SkICAT is constructed in a modular and general fashion and should be readily adaptable to other large-scale imaging surveys.

  10. Light-pollution measurement with the Wide-field all-sky image analyzing monitoring system

    Science.gov (United States)

    Vítek, S.

    2017-07-01

    The purpose of this experiment was to measure light pollution in the capital of Czech Republic, Prague. As a measuring instrument is used calibrated consumer level digital single reflex camera with IR cut filter, therefore, the paper reports results of measuring and monitoring of the light pollution in the wavelength range of 390 - 700 nm, which most affects visual range astronomy. Combining frames of different exposure times made with a digital camera coupled with fish-eye lens allow to create high dynamic range images, contain meaningful values, so such a system can provide absolute values of the sky brightness.

  11. Multimodal wide-field two-photon excitation imaging: characterization of the technique for in vivo applications.

    Science.gov (United States)

    Hwang, Jae Youn; Wachsmann-Hogiu, Sebastian; Ramanujan, V Krishnan; Nowatzyk, Andreas G; Koronyo, Yosef; Medina-Kauwe, Lali K; Gross, Zeev; Gray, Harry B; Farkas, Daniel L

    2011-01-13

    We report fast, non-scanning, wide-field two-photon fluorescence excitation with spectral and lifetime detection for in vivo biomedical applications. We determined the optical characteristics of the technique, developed a Gaussian flat-field correction method to reduce artifacts resulting from non-uniform excitation such that contrast is enhanced, and showed that it can be used for ex vivo and in vivo cellular-level imaging. Two applications were demonstrated: (i) ex vivo measurements of beta-amyloid plaques in retinas of transgenic mice, and (ii) in vivo imaging of sulfonated gallium(III) corroles injected into tumors. We demonstrate that wide-field two photon fluorescence excitation with flat-field correction provides more penetration depth as well as better contrast and axial resolution than the corresponding one-photon wide field excitation for the same dye. Importantly, when this technique is used together with spectral and fluorescence lifetime detection modules, it offers improved discrimination between fluorescence from molecules of interest and autofluorescence, with higher sensitivity and specificity for in vivo applications.

  12. GravityCam: ground-based wide-field high-resolution imaging and high-speed photometry

    Science.gov (United States)

    Dominik, Martin; Mackay, Craig; Steele, Iain; Snodgrass, Colin; Hirsch, Michael; Gråe Jørgensen, Uffe; Hundertmark, Markus; Rebolo, Rafael; Horne, Keith; Bridle, Sarah; Sicardy, Bruno; Bramich, Daniel; Alsubai, Khalid

    2015-12-01

    The image blurring by the Earth's atmosphere generally poses a substantial limitation to ground-based observations. While opportunities in space are scarce, lucky imaging can correct over a much larger patch of sky and with much fainter reference stars. We propose the first of a new kind of versatile instruments, "GravityCam", composed of ~100 EMCCDs, that will open up two entirely new windows to ground-based astronomy: (1) wide-field high-resolution imaging, and (2) wide-field high-speed photometry. Potential applications include (a) a gravitational microlensing survey going 4 magnitudes deeper than current efforts, and thereby gaining a factor 100 in mass at the same sensitivity, which means probing down to Lunar mass or even below, (b) extra-solar planet hunting via transits in galactic bulge fields, with high time resolution well-suited for transit timing variation studies, (c) variable stars in crowded fields, with sensitivity to very short periods, (d) asteroseismology with many bright stars in one pointing, (e) serendipitous occultations of stars by small solar system bodies, giving access to the small end of the Kuiper Belt size distribution and potentially leading to the first detection of true Oort cloud objects, while predicted occultations at high time resolution can reveal atmospheres, satellites, or rings, (f) general data mining of the high-speed variable sky (down to 40 ms cadence).

  13. THE IMAGE OF INVESTMENT AND FINANCIAL SERVICES COMPANIES IN WWW LANDSCAPE (WORLD WIDE WEB

    Directory of Open Access Journals (Sweden)

    Iancu Ioana Ancuta

    2011-07-01

    Full Text Available In a world where the internet and its image are becoming more and more important, this study is about the importance of Investment and Financial Services Companies web sites. Market competition, creates the need of studies, focused on assessing and analyzing the websites of companies who are active in this sector. Our study wants to respond at several questions related to Romanian Investment and Financial Services Companies web sites through four dimensions: content, layout, handling and interactivity. Which web sites are best and from what point of view? Where should financial services companies direct their investments to differentiate themselves and their sites? In fact we want to rank the 58 Investment and Financial Services Companies web sites based on 127 criteria. There are numerous methods for evaluating web pages. The evaluation methods are similar from the structural point of view and the most popular are: Serqual, Sitequal, Webqual / Equal EtailQ, Ewam, e-Serqual, WebQEM (Badulescu, 2008:58. In the paper: "Assessment of Romanian Banks E-Image: A Marketing Perspective" (Catana, Catana and Constantinescu, 2006: 4 the authors point out that there are at least four complex variables: accessibility, functionality, performance and usability. Each of these can be decomposed into simple ones. We used the same method, and we examined from the utility point of view, 58 web sites of Investment and Financial Services Companies based on 127 criteria following a procedure developed by Institut fur ProfNet Internet Marketing, Munster (Germany. The data collection period was 1-30 September 2010. The results show that there are very large differences between corporate sites; their creators are concentrating on the information required by law and aesthetics, neglecting other aspects as communication and online service. In the future we want to extend this study at international level, by applying the same methods of research in 5 countries from

  14. Real-time in vitro Fourier ptychographic microscopy for high resolution wide field of view phase imaging

    CERN Document Server

    Tian, Lei; Yeh, Li-Hao; Chen, Michael; Waller, Laura

    2015-01-01

    For centuries, microscopes have had to trade field of view (FOV) for resolution. Recently, a new computational imaging technique, termed Fourier ptychographic microscopy (FPM), circumvents this limit in order to capture gigapixel-scale images having both wide FOV and high resolution. FPM has enormous potential for revolutionizing biomedical microscopy; however, it has until now been limited to fixed samples, since acquisition time is on the order of minutes. Live biological samples are continuously evolving on multiple spatial and temporal scales, which can cause motion blur. Here, we present a Fast FPM method to achieve sub-second capture times for FPM results with 0.8 NA resolution across a 4x objective's FOV. We demonstrate the first FPM quantitative phase results for both growing and confluent in vitro cell cultures. Experiments capture real-time videos of HeLa and human mammary epithelial (MCF10A) cell division and migration and subcellular dynamical phenomena in adult rat neural stem cells.

  15. Wide-field spectral imaging of human ovary autofluorescence and oncologic diagnosis via previously collected probe data

    Science.gov (United States)

    Renkoski, Timothy E.; Hatch, Kenneth D.; Utzinger, Urs

    2012-03-01

    With no sufficient screening test for ovarian cancer, a method to evaluate the ovarian disease state quickly and nondestructively is needed. The authors have applied a wide-field spectral imager to freshly resected ovaries of 30 human patients in a study believed to be the first of its magnitude. Endogenous fluorescence was excited with 365-nm light and imaged in eight emission bands collectively covering the 400- to 640-nm range. Linear discriminant analysis was used to classify all image pixels and generate diagnostic maps of the ovaries. Training the classifier with previously collected single-point autofluorescence measurements of a spectroscopic probe enabled this novel classification. The process by which probe-collected spectra were transformed for comparison with imager spectra is described. Sensitivity of 100% and specificity of 51% were obtained in classifying normal and cancerous ovaries using autofluorescence data alone. Specificity increased to 69% when autofluorescence data were divided by green reflectance data to correct for spatial variation in tissue absorption properties. Benign neoplasm ovaries were also found to classify as nonmalignant using the same algorithm. Although applied ex vivo, the method described here appears useful for quick assessment of cancer presence in the human ovary.

  16. Gradient Permittivity Meta-Structure model for Wide-field Super-resolution imaging with a sub-45 nm resolution.

    Science.gov (United States)

    Cao, Shun; Wang, Taisheng; Xu, Wenbin; Liu, Hua; Zhang, Hongxin; Hu, Bingliang; Yu, Weixing

    2016-03-21

    A gradient permittivity meta-structure (GPMS) model and its application in super-resolution imaging were proposed and discussed in this work. The proposed GPMS consists of alternate metallic and dielectric films with a gradient permittivity which can support surface plasmons (SPs) standing wave interference patterns with a super resolution. By employing the rigorous numerical FDTD simulation method, the GPMS was carefully simulated to find that the period of the SPs interference pattern is only 84 nm for a 532 nm incident light. Furthermore, the potential application of the GPMS for wide-field super-resolution imaging was also discussed and the simulation results show that an imaging resolution of sub-45 nm can be achieved based on the plasmonic structure illumination microscopic method, which means a 5.3-fold improvement on resolution has been achieved in comparison with conventional epifluorescence microscopy. Moreover, besides the super-resolution imaging application, the proposed GPMS model can also be applied for nanolithography and other areas where super resolution patterns are needed.

  17. A Multi-Frequency Wide-Swath Spaceborne Cloud and Precipitation Imaging Radar

    Science.gov (United States)

    Li, Lihua; Racette, Paul; Heymsfield, Gary; McLinden, Matthew; Venkatesh, Vijay; Coon, Michael; Perrine, Martin; Park, Richard; Cooley, Michael; Stenger, Pete; hide

    2016-01-01

    Microwave and millimeter-wave radars have proven their effectiveness in cloud and precipitation observations. The NASA Earth Science Decadal Survey (DS) Aerosol, Cloud and Ecosystems (ACE) mission calls for a dual-frequency cloud radar (W band 94 GHz and Ka-band 35 GHz) for global measurements of cloud microphysical properties. Recently, there have been discussions of utilizing a tri-frequency (KuKaW-band) radar for a combined ACE and Global Precipitation Measurement (GPM) follow-on mission that has evolved into the Cloud and Precipitation Process Mission (CaPPM) concept. In this presentation we will give an overview of the technology development efforts at the NASA Goddard Space Flight Center (GSFC) and at Northrop Grumman Electronic Systems (NGES) through projects funded by the NASA Earth Science Technology Office (ESTO) Instrument Incubator Program (IIP). Our primary objective of this research is to advance the key enabling technologies for a tri-frequency (KuKaW-band) shared-aperture spaceborne imaging radar to provide unprecedented, simultaneous multi-frequency measurements that will enhance understanding of the effects of clouds and precipitation and their interaction on Earth climate change. Research effort has been focused on concept design and trade studies of the tri-frequency radar; investigating architectures that provide tri-band shared-aperture capability; advancing the development of the Ka band active electronically scanned array (AESA) transmitreceive (TR) module, and development of the advanced radar backend electronics.

  18. Wide-field retinal optical coherence tomography with wavefront sensorless adaptive optics for enhanced imaging of targeted regions.

    Science.gov (United States)

    Polans, James; Keller, Brenton; Carrasco-Zevallos, Oscar M; LaRocca, Francesco; Cole, Elijah; Whitson, Heather E; Lad, Eleonora M; Farsiu, Sina; Izatt, Joseph A

    2017-01-01

    The peripheral retina of the human eye offers a unique opportunity for assessment and monitoring of ocular diseases. We have developed a novel wide-field (>70°) optical coherence tomography system (WF-OCT) equipped with wavefront sensorless adaptive optics (WSAO) for enhancing the visualization of smaller (23°) retina. We demonstrated the ability of our WF-OCT system to acquire non wavefront-corrected wide-field images rapidly, which could then be used to locate regions of interest, zoom into targeted features, and visualize the same region at different time points. A pilot clinical study was conducted on seven healthy volunteers and two subjects with prodromal Alzheimer's disease which illustrated the capability to image Drusen-like pathologies as far as 32.5° from the fovea in un-averaged volume scans. This work suggests that the proposed combination of WF-OCT and WSAO may find applications in the diagnosis and treatment of ocular, and potentially neurodegenerative, diseases of the peripheral retina, including diabetes and Alzheimer's disease.

  19. Real-time, wide-area hyperspectral imaging sensors for standoff detection of explosives and chemical warfare agents

    Science.gov (United States)

    Gomer, Nathaniel R.; Tazik, Shawna; Gardner, Charles W.; Nelson, Matthew P.

    2017-05-01

    Hyperspectral imaging (HSI) is a valuable tool for the detection and analysis of targets located within complex backgrounds. HSI can detect threat materials on environmental surfaces, where the concentration of the target of interest is often very low and is typically found within complex scenery. Unfortunately, current generation HSI systems have size, weight, and power limitations that prohibit their use for field-portable and/or real-time applications. Current generation systems commonly provide an inefficient area search rate, require close proximity to the target for screening, and/or are not capable of making real-time measurements. ChemImage Sensor Systems (CISS) is developing a variety of real-time, wide-field hyperspectral imaging systems that utilize shortwave infrared (SWIR) absorption and Raman spectroscopy. SWIR HSI sensors provide wide-area imagery with at or near real time detection speeds. Raman HSI sensors are being developed to overcome two obstacles present in standard Raman detection systems: slow area search rate (due to small laser spot sizes) and lack of eye-safety. SWIR HSI sensors have been integrated into mobile, robot based platforms and handheld variants for the detection of explosives and chemical warfare agents (CWAs). In addition, the fusion of these two technologies into a single system has shown the feasibility of using both techniques concurrently to provide higher probability of detection and lower false alarm rates. This paper will provide background on Raman and SWIR HSI, discuss the applications for these techniques, and provide an overview of novel CISS HSI sensors focusing on sensor design and detection results.

  20. Development of digital system for the wide-field x-ray imaging detector aboard Kanazawa-SAT3

    Science.gov (United States)

    Kagawa, Yasuaki; Yonetoku, Daisuke; Sawano, Tatsuya; Mihara, Tatehiro; Kyutoku, Koutarou; Ikeda, Hirokazu; Yoshida, Kazuki; Ina, Masao; Ota, Kaichi; Suzuki, Daichi; Miyao, Kouga; Watanabe, Syouta; Hatori, Satoshi; Kume, Kyo; Mizushima, Satoshi; Hasegawa, Takashi

    2017-08-01

    We are planning to launch a micro satellite, Kanazawa-SAT3 , at the end of FY2018 to localize X-ray transients associated with gravitational wave sources. Now we are testing a prototype model of wide-field Xray imaging detector named T-LEX (Transient Localization EXperiment). T-LEX is an orthogonally distributed two sets of 1-dimensional silicon strip detectors with coded aperture masks, and covers more than 1 steradian field of view in the energy range of 1 - 20 keV. Each dimension has 512 readout electrodes (totally 1,024 channels), and they are read out with application specific integrated circuits (ASICs) controlled by two onboard FPGAs. Moreover, each FPGA calculates the cross correlation between the X-ray intensity and mask patterns every 64 msec, makes a histogram of lightcurves and energy spectra, and also plays a role of telemetry/command interface to mission CPU. In this paper, we report an overview of digital electronics system. Especially, we focus on the high-speed imaging processor on FPGA and demonstrate its performance as an X-ray imaging system.

  1. A Very Low Dark Current Temperature-Resistant, Wide Dynamic Range, Complementary Metal Oxide Semiconductor Image Sensor

    Science.gov (United States)

    Mizobuchi, Koichi; Adachi, Satoru; Tejada, Jose; Oshikubo, Hiromichi; Akahane, Nana; Sugawa, Shigetoshi

    2008-07-01

    A very low dark current (VLDC) temperature-resistant approach which best suits a wide dynamic range (WDR) complementary metal oxide semiconductor (CMOS) image sensor with a lateral over-flow integration capacitor (LOFIC) has been developed. By implementing a low electric field photodiode without a trade-off of full well-capacity, reduced plasma damage, re-crystallization, and termination of silicon-silicon dioxide interface states in the front end of line and back end of line (FEOL and BEOL) in a 0.18 µm, two polycrystalline silicon, three metal (2P3M) process, the dark current is reduced to 11 e-/s/pixel (0.35 e-/s/µm2: pixel area normalized) at 60 °C, which is the lowest value ever reported. For further robustness at low and high temperatures, 1/3-in., 5.6-µm pitch, 800×600 pixel sensor chips with low noise readout circuits designed for a signal and noise hold circuit and a programmable gain amplifier (PGA) have also been deposited with an inorganic cap layer on a micro-lens and covered with a metal hermetically sealed package assembly. Image sensing performance results in 2.4 e-rms temporal noise and 100 dB dynamic range (DR) with 237 ke- full well-capacity. The operating temperature range is extended from -40 to 85 °C while retaining good image quality.

  2. Portable lensless wide-field microscopy imaging platform based on digital inline holography and multi-frame pixel super-resolution

    National Research Council Canada - National Science Library

    Antonio C Sobieranski; Fatih Inci; H Cumhur Tekin; Mehmet Yuksekkaya; Eros Comunello; Daniel Cobra; Aldo Von Wangenheim; Utkan Demirci

    2015-01-01

      In this paper, an irregular displacement-based lensless wide-field microscopy imaging platform is presented by combining digital in-line holography and computational pixel super-resolution using multi-frame processing...

  3. Imaging the Moho and V(p)/V(s) ratio in the western Superior Archean craton with wide angle reflections

    Science.gov (United States)

    Kay, I.; Musacchio, G.; White, D.; Asudeh, I.; Roberts, B.; Forsyth, D.; Hajnal, Z.; Koperwhats, B.; Farrell, D.

    1999-01-01

    A refraction/wide-angle reflection survey in northwestern Ontario investigated the Archean Superior Province of the Canadian Shield. Images of apparent Moho topography were produced from both the PmP and SmS Moho wide angle reflections. The average Moho depth is 41 km, and average P- and S-wave velocities 6.6 and 3.8 (??0.05) km/s respectively. The Moho dips southward from 39.5 to 42 km depth over roughly 400 km. From ratios of S and P travel times to the Moho, profiles of V(p)/V(s) were constructed. The average V(p)/V(s) ratios are 1.74 and 1.76 for on the E-W and N-S lines (Poisson's ratio ?? = 0.253 and 0.262 respectively). V(p)/V(s) profiles show a sharp increase from west to east and a gradual increase from north to south, correlating with the distribution of more felsic continental crust and composite crust in the Western Superior.A refraction/wide-angle reflection survey in northwestern Ontario investigated the Archean Superior Province of the Canadian Shield. Images of apparent Moho topography were produced from both the PmP and SmS Moho wide angle reflections. The average Moho depth is 41 km, and average P- and S-wave velocities 6.6 and 3.8 (?? 0.05) km/s respectively. The Moho dips southward from 39.5 to 42 km depth over roughly 400 km. From ratios of S and P travel times to the Moho, profiles of Vp/Vs were constructed. The average Vp/Vs ratios are 1.74 and 1.76 for on the E-W and N-S lines (Poisson's ratio ?? = 0.253 and 0.262 respectively). Vp/Vs profiles show a sharp increase from west to east and a gradual increase from north to south, correlating with the distribution of more felsic continental crust and composite crust in the Western Superior.

  4. Wide-field color imaging of scatter-based tissue contrast using both high spatial frequency illumination and cross-polarization gating.

    Science.gov (United States)

    Carlson, Mackenzie L; McClatchy, David M; Gunn, Jason R; Elliott, Jonathan T; Paulsen, Keith D; Kanick, Stephen C; Pogue, Brian W

    2017-08-11

    This study characterizes the scatter-specific tissue contrast that can be obtained by high spatial frequency (HSF) domain imaging and cross-polarization (CP) imaging, using a standard color imaging system, and how combining them may be beneficial. Both HSF and CP approaches are known to modulate the sensitivity of epi-illumination reflectance images between diffuse multiply scattered and superficially backscattered photons, providing enhanced contrast from microstructure and composition than what is achieved by standard wide-field imaging. Measurements in tissue-simulating optical phantoms show that CP imaging returns localized assessments of both scattering and absorption effects, while HSF has uniquely specific sensitivity to scatter-only contrast, with a strong suppression of visible contrast from blood. The combination of CP and HSF imaging provided an expanded sensitivity to scatter compared with CP imaging, while rejecting specular reflections detected by HSF imaging. ex vivo imaging of an atlas of dissected rodent organs/tissues demonstrated the scatter-based contrast achieved with HSF, CP and HSF-CP imaging, with the white light spectral signal returned by each approach translated to a color image for intuitive encoding of scatter-based contrast within images of tissue. The results suggest that visible CP-HSF imaging could have the potential to aid diagnostic imaging of lesions in skin or mucosal tissues and organs, where just CP is currently the standard practice imaging modality. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. ProtoEXIST2: Advanced Wide-field Imaging CZT Detector Development For The HET On The Proposed EXIST Mission

    Science.gov (United States)

    Hong, JaeSub; Allen, B.; Grindlay, J.; Barthelmy, S.; Baker, R.; Gehrels, N.; Cook, W.; Kaye, S.; Harrison, F.

    2010-03-01

    We describe our development of ProtoEXIST2, the advanced CZT imaging detector and wide field telescope prototype for the High Energy Telescope (HET) on the proposed Energetic X-ray Imaging Survey Telescope (EXIST) mission. EXIST is a multi-wavelength Medium class mission which would explore the early Universe using high redshift Gamma-ray Bursts and survey black holes on all scales. ProtoEXIST2 will demonstrate the feasibility of a large scale imaging module (256 cm2) with a close-tiled array of fine pixel (0.6 mm) CZT with a balloon flight test in 2010 or 2011. This second generation close-tiled CZT imager follows ProtoEXIST1, which had a recent successful balloon flight (see Allen et al in this meeting) using the same area CZT detector module (256 cm2) but with larger pixel size (2.5mm). For signal readout and event processing, we use the Direct-Bond (DB) ASIC, developed for the NuSTAR mission to be used in a close-tiled 2 x 2 array of 2x2 cm2 CZT detectors, each with 32x32 pixels. The DB-ASIC is attractive for a large scale implementation of tiled imaging CZT detectors given its low noise and power consumption (70uW/pixel). We are developing readout for the DB-ASIC that incorporates our back-end FPGA readout architecture developed for ProtoEXIST1 in order to accomplish the 256 cm2 detector module area with totally vertical integration (i.e. no auxialliary boards to the sides of the module. This is required to tile large numbers of modules into the very large total area (4.5m^2) proposed for the HET on EXIST. We review the design of the EXIST/HET and its optimum shielding in light of our ProtoEXIST1 balloon flight and our plan for future development of ProtoEXIST3, a final EXIST/HET detector module that would incorporate a still lower power version of the DB ASIC.

  6. Automated choroid segmentation in three-dimensional 1 - μ m wide-view OCT images with gradient and regional costs

    Science.gov (United States)

    Shi, Fei; Tian, Bei; Zhu, Weifang; Xiang, Dehui; Zhou, Lei; Xu, Haobo; Chen, Xinjian

    2016-12-01

    Choroid thickness and volume estimated from optical coherence tomography (OCT) images have emerged as important metrics in disease management. This paper presents an automated three-dimensional (3-D) method for segmenting the choroid from 1-μm wide-view swept source OCT image volumes, including the Bruch's membrane (BM) and the choroidal-scleral interface (CSI) segmentation. Two auxiliary boundaries are first detected by modified Canny operators and then the optical nerve head is detected and removed. The BM and the initial CSI segmentation are achieved by 3-D multiresolution graph search with gradient-based cost. The CSI is further refined by adding a regional cost, calculated from the wavelet-based gradual intensity distance. The segmentation accuracy is quantitatively evaluated on 32 normal eyes by comparing with manual segmentation and by reproducibility test. The mean choroid thickness difference from the manual segmentation is 19.16±4.32 μm, the mean Dice similarity coefficient is 93.17±1.30%, and the correlation coefficients between fovea-centered volumes obtained on repeated scans are larger than 0.97.

  7. Handheld and mobile hyperspectral imaging sensors for wide-area standoff detection of explosives and chemical warfare agents

    Science.gov (United States)

    Gomer, Nathaniel R.; Gardner, Charles W.; Nelson, Matthew P.

    2016-05-01

    Hyperspectral imaging (HSI) is a valuable tool for the investigation and analysis of targets in complex background with a high degree of autonomy. HSI is beneficial for the detection of threat materials on environmental surfaces, where the concentration of the target of interest is often very low and is typically found within complex scenery. Two HSI techniques that have proven to be valuable are Raman and shortwave infrared (SWIR) HSI. Unfortunately, current generation HSI systems have numerous size, weight, and power (SWaP) limitations that make their potential integration onto a handheld or field portable platform difficult. The systems that are field-portable do so by sacrificing system performance, typically by providing an inefficient area search rate, requiring close proximity to the target for screening, and/or eliminating the potential to conduct real-time measurements. To address these shortcomings, ChemImage Sensor Systems (CISS) is developing a variety of wide-field hyperspectral imaging systems. Raman HSI sensors are being developed to overcome two obstacles present in standard Raman detection systems: slow area search rate (due to small laser spot sizes) and lack of eye-safety. SWIR HSI sensors have been integrated into mobile, robot based platforms and handheld variants for the detection of explosives and chemical warfare agents (CWAs). In addition, the fusion of these two technologies into a single system has shown the feasibility of using both techniques concurrently to provide higher probability of detection and lower false alarm rates. This paper will provide background on Raman and SWIR HSI, discuss the applications for these techniques, and provide an overview of novel CISS HSI sensors focused on sensor design and detection results.

  8. Outcome of universal newborn eye screening with wide-field digital retinal image acquisition system: a pilot study.

    Science.gov (United States)

    Goyal, P; Padhi, T R; Das, T; Pradhan, L; Sutar, S; Butola, S; Behera, U C; Jain, L; Jalali, S

    2017-07-24

    PurposeTo evaluate the outcome of universal newborn eye screening with wide-field digital retinal imaging (WFDRI) system.MethodsIn this pilot study, we examined 1152 apparently healthy newborn infants in the obstetrics and gynecology ward of a civil hospital in Eastern India over 1.5 years. The examination included external eye examination, red reflex test and fundus imaging by WFDRI (RetCam II, Clarity medical system, Pleasanton, CA, USA) by a trained optometrist. The pathologies detected, net monetary gain and skilled manpower saved were documented. The results were compared with three similar studies thus far published in the literature.ResultsOcular abnormality of any kind was seen in 172 (14.93%) babies. Retinal hemorrhage in 153 babies (88.9% of all abnormal findings) was the most common abnormality; it was bilateral in 118 (77.12%) babies and 4 babies had foveal hemorrhage. Other abnormalities included vitreous hemorrhage (n=1), congenital glaucoma (n=2), uveal coloboma (n=2), retinopathy mimicking retinopathy of prematurity (n=2), and cystic fovea (n=3). The retinal hemorrhages resolved spontaneously in all eyes. One baby with congenital glaucoma received surgery and the other was treated medically. The benefits included savings in skilled manpower, a net monetary gain of INR 4.195 million (US$ 62,612) and skilled manpower saving by 319.4 h.ConclusionsThe universal neonatal eye screening using WFDRI detected pathologies that needed immediate care or regular follow up; saved skilled manpower with a net monetary gain. But compared to a red reflex test the benefits were marginal in terms of detecting treatment warranting ocular pathologies.Eye advance online publication, 24 July 2017; doi:10.1038/eye.2017.129.

  9. Wide range instantaneous temperature measurements of convective fluid flows by using a schlieren system based in color images

    Science.gov (United States)

    Martínez-González, A.; Moreno-Hernández, D.; Monzón-Hernández, D.; León-Rodríguez, M.

    2017-06-01

    In the schlieren method, the deflection of light by the presence of an inhomogeneous medium is proportional to the gradient of its refractive index. Such deflection, in a schlieren system, is represented by light intensity variations on the observation plane. Then, for a digital camera, the intensity level registered by each pixel depends mainly on the variation of the medium refractive index and the status of the digital camera settings. Therefore, in this study, we regulate the intensity value of each pixel by controlling the camera settings such as exposure time, gamma and gain values in order to calibrate the image obtained to the actual temperature values of a particular medium. In our approach, we use a color digital camera. The images obtained with a color digital camera can be separated on three different color-channels. Each channel corresponds to red, green, and blue color, moreover, each one has its own sensitivity. The differences in sensitivity allow us to obtain a range of temperature values for each color channel. Thus, high, medium and low sensitivity correspond to green, blue, and red color channel respectively. Therefore, by adding up the temperature contribution of each color channel we obtain a wide range of temperature values. Hence, the basic idea in our approach to measure temperature, using a schlieren system, is to relate the intensity level of each pixel in a schlieren image to the corresponding knife-edge position measured at the exit focal plane of the system. Our approach was applied to the measurement of instantaneous temperature fields of the air convection caused by a heated rectangular metal plate and a candle flame. We found that for the metal plate temperature measurements only the green and blue color-channels were required to sense the entire phenomena. On the other hand, for the candle case, the three color-channels were needed to obtain a complete measurement of temperature. In our study, the candle temperature was took as

  10. Mapping the Tidal Destruction of the Hercules Dwarf: A Wide-field DECam Imaging Search for RR Lyrae Stars

    Science.gov (United States)

    Garling, Christopher; Willman, Beth; Sand, David J.; Hargis, Jonathan; Crnojević, Denija; Bechtol, Keith; Carlin, Jeffrey L.; Strader, Jay; Zou, Hu; Zhou, Xu; Nie, Jundan; Zhang, Tianmeng; Zhou, Zhimin; Peng, Xiyan

    2018-01-01

    We investigate the hypothesized tidal disruption of the Hercules ultra-faint dwarf galaxy (UFD). Previous tidal disruption studies of the Hercules UFD have been hindered by the high degree of foreground contamination in the direction of the dwarf. We bypass this issue by using RR Lyrae stars, which are standard candles with a very low field-volume density at the distance of Hercules. We use wide-field imaging from the Dark Energy Camera on CTIO to identify candidate RR Lyrae stars, supplemented with observations taken in coordination with the Beijing–Arizona Sky Survey on the Bok Telescope. Combining color, magnitude, and light-curve information, we identify three new RR Lyrae stars associated with Hercules. All three of these new RR Lyrae stars lie outside its published tidal radius. When considered with the nine RR Lyrae stars already known within the tidal radius, these results suggest that a substantial fraction of Hercules’ stellar content has been stripped. With this degree of tidal disruption, Hercules is an interesting case between a visibly disrupted dwarf (such as the Sagittarius dwarf spheroidal galaxy) and one in dynamic equilibrium. The degree of disruption also shows that we must be more careful with the ways we determine object membership when estimating dwarf masses in the future. One of the three discovered RR Lyrae stars sits along the minor axis of Hercules, but over two tidal radii away. This type of debris is consistent with recent models that suggest Hercules’ orbit is aligned with its minor axis.

  11. Argus+: The Future of Wide-Field, Spectral-Line Imaging at 3-mm with the Green Bank Telescope

    Science.gov (United States)

    Maddalena, Ronald; Frayer, David; Lockman, Felix; O'Neil, Karen; White, Steven; Argus+ Collaboration

    2018-01-01

    The Robert C Byrd Green Bank Telescope has met its design goal of providing high-quality observations at 115 GHz. Observers also have access to the new, 16-pixel, 3-mm Argus receiver, which is providing high-dynamic range images over wide fields for the multitude of spectral lines between 85 and 115 GHz, including CO, 13CO, C18O, SiO, HCN, HCO+, HNC, N2H+, and CS. The small number of pixels in Argus limits its ability to map many of the most interesting objects whose extent exceeds many arc-minutes. The successful performance of Argus, and its modular design, demonstrates that receivers with many more pixels could be built for the GBT. A 12 x 12 array of the Argus design would have mapping speeds about nine times faster than Argus without suffering any degradation in performance for the outer pixels in the array. We present our plans to build the next-generation Argus instrument (Argus+) with 144-pixels, a footprint 5’x5’, and 7" resolution at 110 GHz. The project will be a collaboration between the Green Bank Observatory and university groups, who will supply key components. The key science drivers for Argus+ are studies of molecular filaments in the Milky Way, studies of molecular clouds in nearby galaxies, and the observations of rapidly evolving solar system objects.

  12. Combine TV-L1 model with guided image filtering for wide and faint ring artifacts correction of in-line x-ray phase contrast computed tomography.

    Science.gov (United States)

    Ji, Dongjiang; Qu, Gangrong; Hu, Chunhong; Zhao, Yuqing; Chen, Xiaodong

    2017-08-24

    In practice, mis-calibrated detector pixels give rise to wide and faint ring artifacts in the reconstruction image of the In-line phase-contrast computed tomography (IL-PC-CT). Ring artifacts correction is essential in IL-PC-CT. In this study, a novel method of wide and faint ring artifacts correction was presented based on combining TV-L1 model with guided image filtering (GIF) in the reconstruction image domain. The new correction method includes two main steps namely, the GIF step and the TV-L1 step. To validate the performance of this method, simulation data and real experimental synchrotron data are provided. The results demonstrate that TV-L1 model with GIF step can effectively correct the wide and faint ring artifacts for IL-PC-CT.

  13. The ESO-Spitzer Imaging extragalactic Survey (ESIS). II. VIMOS I, z wide field imaging of ELAIS-S1 and selection of distant massive galaxies

    Science.gov (United States)

    Berta, S.; Rubele, S.; Franceschini, A.; Held, E. V.; Rizzi, L.; Rodighiero, G.; Cimatti, A.; Dias, J. E.; Feruglio, C.; La Franca, F.; Lonsdale, C. J.; Maiolino, R.; Matute, I.; Rowan-Robinson, M.; Sacchi, N.; Zamorani, G.

    2008-09-01

    Context: The ESO-Spitzer Imaging extragalactic Survey (ESIS) is the optical follow up of the Spitzer Wide-area Infra-Red Extragalactic survey (SWIRE) in the ELAIS-S1 region of the sky. Aims: In the era of observational cosmology, the main efforts are focused on the study of galaxy evolution and its environmental dependence. Wide area, multiwavelength, extragalactic surveys are needed in order to probe sufficiently large volumes, minimize cosmic variance and find significant numbers of rare objects. Methods: We present VIMOS I and z band imaging belonging to the ESIS survey. A total of ~4 deg2 was targeted in I and ~1 deg2 in z. Accurate data processing includes removal of fringing, and mosaicking of the complex observing pattern. Completeness levels and photometric uncertainties are estimated through simulations. The multi-wavelength data available in the area are exploited to identify high-redshift galaxies, using the IR-peak technique. Results: More than 300 000 galaxies have been detected in the I band and ~50 000 in the z band. Object coordinates are defined within an uncertainty of ~0.2 arcsec rms, with respect to GSC 2.2. We reach a 90% average completeness at 23.1 and 22.5 mag (Vega) in the I and z bands, respectively. On the basis of IRAC colors, we identify galaxies having the 1.6 μm stellar peak shifted to z = 1-3. The new I, z band data provide reliable constraints to help avoid low-redshift interlopers and reinforce this selection. Roughly 1000 galaxies between z = 2-3 are identified over the ESIS ~4 deg^2, at the SWIRE 5.8 μm depth (25.8 μJy at 3σ). These are the best galaxy candidates to dominate the massive tail (M > 1011 M_⊙) of the z > 2 mass function. Based on observations collected at the European Southern Observatory, Chile, ESO No. 168.A-0322(A). ESIS web page:http://www.astro.unipd.it/esis Appendix A, Tables 4 and 5 are only available at http://www.aanda.org The full I and z band catalogs (see Table [see full textsee full textsee full

  14. Low-frequency wide-field fluorescence lifetime imaging using a high-power near-infrared light-emitting diode light source

    OpenAIRE

    Gioux, Sylvain; Lomnes, Stephen J.; Choi, Hak Soo; Frangioni, John V.

    2010-01-01

    Fluorescence lifetime imaging (FLi) could potentially improve exogenous near-infrared (NIR) fluorescence imaging, because it offers the capability of discriminating a signal of interest from background, provides real-time monitoring of a chemical environment, and permits the use of several different fluorescent dyes having the same emission wavelength. We present a high-power, LED-based, NIR light source for the clinical translation of wide-field (larger than 5 cm in diameter) FLi at frequenc...

  15. High-throughput dual-color precision imaging for brain-wide mapping of the connectome with cytoarchitectonic landmarks at the cellular level (Conference Presentation)

    Science.gov (United States)

    Luo, Qingming; Gong, Hui; Yuan, Jing; Li, Xiangning; Li, Anan; Xu, Tonghui

    2017-02-01

    Deciphering the fine morphology and precise location of neurons and neural circuits are crucial to enhance our understanding of brain function and diseases. Traditionally, we have to map brain images to coarse axial-sampling planar reference atlases to orient neural structures. However, this means might fail to orient neural projections at single-cell resolution due to position errors resulting from individual differences at the cellular level. Here, we present a high-throughput imaging method that can automatically obtain the fine morphologies and precise locations of both neurons and circuits, employing wide-field large-volume tomography to acquire three-dimensional images of thick tissue and implementing real-time soma counterstaining to obtain cytoarchitectonic landmarks during the imaging process. The reconstruction and orientation of brain-wide neural circuits at single-neuron resolution can be accomplished for the same mouse brain without additional counterstains or image registration. Using our method, mouse brain imaging datasets of multiple type-specific neurons and circuits were successfully acquired, demonstrating the versatility. The results show that the simultaneous acquisition of labeled neural structures and cytoarchitecture reference at single-neuron resolution in the same brain greatly facilitates precise tracing of long-range projections and accurate locating of nuclei. Our method provides a novel and effective tool for application in studies on genetic dissection, brain function and the pathology of the nervous system.

  16. A population-wide screening and tailored intervention platform for eating disorders on college campuses: the healthy body image program.

    Science.gov (United States)

    Jones, Megan; Kass, Andrea E; Trockel, Mickey; Glass, Alan I; Wilfley, Denise E; Taylor, C Barr

    2014-01-01

    This article presents a new approach to intervention for eating disorders and body image concerns on college campuses, using a model of integrated eating disorder screening and intervention. Formative data on implementation feasibility are presented. College students enrolled at 2 universities between 2011 and 2012. The Healthy Body Image program is an evidence-based screening and intervention platform, enacted via community and online resources. An online screen was used to identify students at varying levels of risk or eating disorder symptom status; responses were used to direct students to universal or targeted online interventions or further evaluation. Universal prevention programs to improve healthy weight regulation and body image culture were offered to all students. Formative data from 1,551 students illustrates the application of this model. The Healthy Body Image program is feasible to deliver and provides a comprehensive system of screening, evidence-based intervention, and community culture change.

  17. Wide-field, full-field optical coherence microscopy for high-axial-resolution phase and amplitude imaging.

    Science.gov (United States)

    Federici, Antoine; da Costa, Henrique S Gutierrez; Ogien, Jonas; Ellerbee, Audrey K; Dubois, Arnaud

    2015-09-20

    An original single-objective, full-field optical coherence microscopy system is reported that is capable of imaging both the phase and the amplitude of semi-transparent samples over a field of view of 17.5  mm×17.5  mm with an axial sectioning resolution of 1.5 μm. A special stack acquisition arrangement ensures optimal reachable imaging depth. Several phase-shifting interferometry algorithms for phase measurement with broadband light are compared theoretically and experimentally. Using the phase information, noninvasive depth-resolved topographic images of multilayer samples are produced to characterize each layer by measuring their defects and curvature with a nanometric scale precision. Using the amplitude information, tomographic images with a constant detection sensitivity of ∼80  dB through the entire field of view are obtained and applied to biological specimens.

  18. Challenges and advantages in wide-field optical coherence tomography angiography imaging of the human retinal and choroidal vasculature at 1.7-MHz A-scan rate

    Science.gov (United States)

    Poddar, Raju; Migacz, Justin V.; Schwartz, Daniel M.; Werner, John S.; Gorczynska, Iwona

    2017-10-01

    We present noninvasive, three-dimensional, depth-resolved imaging of human retinal and choroidal blood circulation with a swept-source optical coherence tomography (OCT) system at 1065-nm center wavelength. Motion contrast OCT imaging was performed with the phase-variance OCT angiography method. A Fourier-domain mode-locked light source was used to enable an imaging rate of 1.7 MHz. We experimentally demonstrate the challenges and advantages of wide-field OCT angiography (OCTA). In the discussion, we consider acquisition time, scanning area, scanning density, and their influence on visualization of selected features of the retinal and choroidal vascular networks. The OCTA imaging was performed with a field of view of 16 deg (5 mm×5 mm) and 30 deg (9 mm×9 mm). Data were presented in en face projections generated from single volumes and in en face projection mosaics generated from up to 4 datasets. OCTA imaging at 1.7 MHz A-scan rate was compared with results obtained from a commercial OCTA instrument and with conventional ophthalmic diagnostic methods: fundus photography, fluorescein, and indocyanine green angiography. Comparison of images obtained from all methods is demonstrated using the same eye of a healthy volunteer. For example, imaging of retinal pathology is presented in three cases of advanced age-related macular degeneration.

  19. Wide-field-of-view phase-contrast imaging of nanostructures with a comparatively large polychromatic soft x-ray plasma source.

    Science.gov (United States)

    Gasilov, S V; Faenov, A Ya; Pikuz, T A; Fukuda, Y; Kando, M; Kawachi, T; Skobelev, I Yu; Daido, H; Kato, Y; Bulanov, S V

    2009-11-01

    Polychromatic soft x-ray plasma sources were not previously considered to be among the sources suitable for the propagation based phase contrast imaging because of their comparatively large emission-zone size. In the current work a scheme based on the combination of soft x-ray emission of multicharged ions, generated by the interaction of femtosecond laser pulses with an ultrasonic jet of gas clusters, and an LiF crystal detector was used to obtain phase-enhanced high-resolution images of micro- and nanoscale objects in a wide field of view.

  20. An automated wide-field time-gated optically sectioning fluorescence lifetime imaging multiwell plate reader for high-content analysis of protein-protein interactions

    Science.gov (United States)

    Alibhai, Dominic; Kumar, Sunil; Kelly, Douglas; Warren, Sean; Alexandrov, Yuriy; Munro, Ian; McGinty, James; Talbot, Clifford; Murray, Edward J.; Stuhmeier, Frank; Neil, Mark A. A.; Dunsby, Chris; French, Paul M. W.

    2011-03-01

    We describe an optically-sectioned FLIM multiwell plate reader that combines Nipkow microscopy with wide-field time-gated FLIM, and its application to high content analysis of FRET. The system acquires sectioned FLIM images in protein. It has been applied to study the formation of immature HIV virus like particles (VLPs) in live cells by monitoring Gag-Gag protein interactions using FLIM FRET of HIV-1 Gag transfected with CFP or YFP. VLP formation results in FRET between closely packed Gag proteins, as confirmed by our FLIM analysis that includes automatic image segmentation.

  1. Enterprise-wide implementation of digital radiography in oral and maxillofacial imaging: the University of Florida Dentistry System.

    Science.gov (United States)

    Nair, Madhu K; Pettigrew, James C; Loomis, Jeffrey S; Bates, Robert E; Kostewicz, Stephen; Robinson, Boyd; Sweitzer, Jean; Dolan, Teresa A

    2009-06-01

    The implementation of digital radiography in dentistry in a large healthcare enterprise setting is discussed. A distinct need for a dedicated dental picture archiving and communication systems (PACS) exists for seamless integration of different vendor products across the system. Complex issues are contended with as each clinical department migrated to a digital environment with unique needs and workflow patterns. The University of Florida has had a dental PACS installed over 2 years ago. This paper describes the process of conversion from film-based imaging from the planning stages through clinical implementation. Dentistry poses many unique challenges as it strives to achieve better integration with systems primarily designed for imaging; however, the technical requirements for high-resolution image capture in dentistry far exceed those in medicine, as most routine dental diagnostic tasks are challenging. The significance of specification, evaluation, vendor selection, installation, trial runs, training, and phased clinical implementation is emphasized.

  2. Ultra Wide X-Band Microwave Imaging of Concealed Weapons and Explosives Using 3D-SAR Technique

    Directory of Open Access Journals (Sweden)

    P. Millot

    2015-01-01

    Full Text Available In order to detect and image concealed weapons and explosives, an electromagnetic imaging tool with its related signal processing is presented. The aim is to penetrate clothes and to find personal-born weapons and explosives under clothes. The chosen UWB frequency range covers the whole X-band. The frequency range is justified after transmission measurements of numerous clothes that are dry or slightly wet. The apparatus and the 3D near-field SAR processor are described. A strategy for contour identification is presented with results of some simulants of weapon and explosive. A conclusion is drawn on the possible future of this technique.

  3. Long-range and depth-selective imaging of macroscopic targets using low-coherence and wide-field interferometry (Conference Presentation)

    Science.gov (United States)

    Woo, Sungsoo; Kang, Sungsam; Yoon, Changhyeong; Choi, Wonshik

    2016-03-01

    With the advancement of 3D display technology, 3D imaging of macroscopic objects has drawn much attention as they provide the contents to display. The most widely used imaging methods include a depth camera, which measures time of flight for the depth discrimination, and various structured illumination techniques. However, these existing methods have poor depth resolution, which makes imaging complicated structures a difficult task. In order to resolve this issue, we propose an imaging system based upon low-coherence interferometry and off-axis digital holographic imaging. By using light source with coherence length of 200 micro, we achieved the depth resolution of 100 micro. In order to map the macroscopic objects with this high axial resolution, we installed a pair of prisms in the reference beam path for the long-range scanning of the optical path length. Specifically, one prism was fixed in position, and the other prism was mounted on a translation stage and translated in parallel to the first prism. Due to the multiple internal reflections between the two prisms, the overall path length was elongated by a factor of 50. In this way, we could cover a depth range more than 1 meter. In addition, we employed multiple speckle illuminations and incoherent averaging of the acquired holographic images for reducing the specular reflections from the target surface. Using this newly developed system, we performed imaging targets with multiple different layers and demonstrated imaging targets hidden behind the scattering layers. The method was also applied to imaging targets located around the corner.

  4. UltraWide Band (UWB) Radar for the High-resolution Imaging of Martian Regolith for Human Exploration

    Science.gov (United States)

    Gim, Y.; Jordan, R.; Quddus, M.; Heggy, E.; Plaut, J.-J.

    2012-06-01

    We propose to develop an Ultra-WideBand (UWB) radar that would enable a rover or an astronaut on the surface of Mars to survey their surroundings and readily identify water ice, hydrate minerals, or volatiles buried at Mars shallow subsurface < 1m.

  5. 3D wide field-of-view Gabor-domain optical coherence microscopy advancing real-time in-vivo imaging and metrology

    Science.gov (United States)

    Canavesi, Cristina; Cogliati, Andrea; Hayes, Adam; Tankam, Patrice; Santhanam, Anand; Rolland, Jannick P.

    2017-02-01

    Real-time volumetric high-definition wide-field-of-view in-vivo cellular imaging requires micron-scale resolution in 3D. Compactness of the handheld device and distortion-free images with cellular resolution are also critically required for onsite use in clinical applications. By integrating a custom liquid lens-based microscope and a dual-axis MEMS scanner in a compact handheld probe, Gabor-domain optical coherence microscopy (GD-OCM) breaks the lateral resolution limit of optical coherence tomography through depth, overcoming the tradeoff between numerical aperture and depth of focus, enabling advances in biotechnology. Furthermore, distortion-free imaging with no post-processing is achieved with a compact, lightweight handheld MEMS scanner that obtained a 12-fold reduction in volume and 17-fold reduction in weight over a previous dual-mirror galvanometer-based scanner. Approaching the holy grail of medical imaging - noninvasive real-time imaging with histologic resolution - GD-OCM demonstrates invariant resolution of 2 μm throughout a volume of 1 x 1 x 0.6 mm3, acquired and visualized in less than 2 minutes with parallel processing on graphics processing units. Results on the metrology of manufactured materials and imaging of human tissue with GD-OCM are presented.

  6. Development of Tiled Imaging CZT Detectors for Sensitive Wide-Field Hard X-Ray Surveys to EXIST

    Science.gov (United States)

    Grindlay, J.; Hong, J.; Allen, B.; Barthelmy, S.; Baker, R.

    2011-01-01

    Motivated by the proposed EXIST mission, a "medium-class" space observatory to survey black holes and the Early Universe proposed to the 2010 NAS/NRC Astronomy and Astrophysics Decadal Survey, we have developed the first "large" area 256 sq cm close-tiled (0.6 mm gaps) hard X-ray (20-600 keV) imaging detector employing pixelated (2.5 mm) CdZnTe (CZT) detectors, each 2 x 2 x 0.5 cubic cm. We summarize the design, development and operation of this detector array (8 x 8 CZTs) and its performance as the imager for a coded aperture telescope on a high altitude (40 km) balloon flight in October. 2009, as the ProtoEX1STl payload. We then outline our current development of a second-generation imager, ProtcEXIST2. with 0.6 mm pixels on a 32 x 32 array on each CZT, and how it will lead to the ultimate imaging system needed for EXIST. Other applications of this technology will also be mentioned.

  7. HST far-ultraviolet imaging of DG Tauri. Fluorescent molecular hydrogen emission from the wide opening-angle outflow

    Science.gov (United States)

    Schneider, P. C.; Eislöffel, J.; Güdel, M.; Günther, H. M.; Herczeg, G.; Robrade, J.; Schmitt, J. H. M. M.

    2013-09-01

    One of the most thoroughly studied jets from all young stellar objects is the jet of DG Tau, which we imaged in the far-ultraviolet with the Hubble Space Telescope for the first time. These high spatial resolution images were obtained with long-pass filters and allow us to construct images tracing mainly H2 and C iv emission. We find that the H2 emission appears as a limb-brightened cone with additional emission close to the jet axis. The length of the rims is about 0.″3 or 42 AU before their brightness strongly drops, and the opening angle is about 90°. Comparing our far-ultraviolet data with near-infrared data we find that the fluorescent H2 emission probably traces the outer, cooler part of the disk wind while an origin of the H2 emission in the surface layers (atmosphere) of the (flared) disk is unlikely. Furthermore, the spatial shape of the H2 emission shows little variation over six years which suggests that the outer part of the disk wind is rather stable and probably not associated with the formation of individual knots. The C iv image shows that the emission is concentrated towards the jet axis. We find no indications for additional C iv emission at larger distances, which strengthens the association with the X-ray emission observed to originate within the DG Tau jet.

  8. Development of tiled imaging CZT detectors for sensitive wide-field hard X-ray surveys to EXIST

    Science.gov (United States)

    Grindlay, J.; Hong, J.; Allen, B.; Barthelmy, S.; Baker, R.

    2011-10-01

    Motivated by the proposed EXIST mission, a "medium-class" space observatory to survey black holes and the Early Universe proposed to the 2010 NAS/NRC Astronomy and Astrophysics Decadal Survey, we have developed the first "large" area 256 cm 2 close-tiled (0.6 mm gaps) hard X-ray (20-600 keV) imaging detector employing pixelated (2.5 mm) CdZnTe (CZT) detectors, each 2×2×0.5 cm 3. We summarize the design, development and operation of this detector array (8×8 CZTs) and its performance as the imager for a coded aperture telescope on a high altitude (40 km) balloon flight in October, 2009, as the ProtoEXIST1 payload. We then outline our current development of a second-generation imager, ProtoEXIST2, with 0.6 mm pixels on a 32×32 array on each CZT, and how it will lead to the ultimate imaging system needed for EXIST. Other applications of this technology will also be mentioned.

  9. Photon counting imaging with an electron-bombarded CCD: Towards wide-field time-correlated single photon counting (TCSPC)

    Energy Technology Data Exchange (ETDEWEB)

    Hirvonen, Liisa M.; Jiggins, Stephen; Sergent, Nicolas; Zanda, Gianmarco; Suhling, Klaus, E-mail: klaus.suhling@kcl.ac.uk

    2015-07-01

    Single photon detecting capabilities of an electron-bombarded CCD (EBCCD), where a photon is converted into a photoelectron that is accelerated through a high voltage before hitting the CCD chip, were characterised. The photon event pulse height distribution was found to be linearly dependent on the gain voltage. Based on these results, we propose that a gain voltage sweep during exposure in an EBCCD or EBCMOS camera would allow photon arrival time determination from the photon event pulse height with sub-frame exposure time resolution. This effectively uses an electron-bombarded sensor as a parallel-processing photoelectronic time-to-amplitude converter (TAC), or a 2-dimensional streak camera. Several applications that require timing of photon arrival, including fluorescence lifetime imaging microscopy (FLIM), may benefit from this approach. Moreover, the EBCCD was used on a fluorescence microscope to image fluorescently labelled cells in single photon counting mode.

  10. Preclinical evaluation of spatial frequency domain-enabled wide-field quantitative imaging for enhanced glioma resection

    Science.gov (United States)

    Sibai, Mira; Fisher, Carl; Veilleux, Israel; Elliott, Jonathan T.; Leblond, Frederic; Roberts, David W.; Wilson, Brian C.

    2017-07-01

    5-Aminolevelunic acid-induced protoporphyrin IX (PpIX) fluorescence-guided resection (FGR) enables maximum safe resection of glioma by providing real-time tumor contrast. However, the subjective visual assessment and the variable intrinsic optical attenuation of tissue limit this technique to reliably delineating only high-grade tumors that display strong fluorescence. We have previously shown, using a fiber-optic probe, that quantitative assessment using noninvasive point spectroscopic measurements of the absolute PpIX concentration in tissue further improves the accuracy of FGR, extending it to surgically curable low-grade glioma. More recently, we have shown that implementing spatial frequency domain imaging with a fluorescent-light transport model enables recovery of two-dimensional images of [PpIX], alleviating the need for time-consuming point sampling of the brain surface. We present first results of this technique modified for in vivo imaging on an RG2 rat brain tumor model. Despite the moderate errors in retrieving the absorption and reduced scattering coefficients in the subdiffusive regime of 14% and 19%, respectively, the recovered [PpIX] maps agree within 10% of the point [PpIX] values measured by the fiber-optic probe, validating its potential as an extension or an alternative to point sampling during glioma resection.

  11. Wide range local resistance imaging on fragile materials by conducting probe atomic force microscopy in intermittent contact mode

    Energy Technology Data Exchange (ETDEWEB)

    Vecchiola, Aymeric [Laboratoire de Génie électrique et électronique de Paris (GeePs), UMR 8507 CNRS-CentraleSupélec, Paris-Sud and UPMC Universities, 11 rue Joliot-Curie, Plateau de Moulon, 91192 Gif-sur-Yvette (France); Concept Scientific Instruments, ZA de Courtaboeuf, 2 rue de la Terre de Feu, 91940 Les Ulis (France); Unité Mixte de Physique CNRS-Thales UMR 137, 1 avenue Augustin Fresnel, 91767 Palaiseau (France); Chrétien, Pascal; Schneegans, Olivier; Mencaraglia, Denis; Houzé, Frédéric, E-mail: frederic.houze@geeps.centralesupelec.fr [Laboratoire de Génie électrique et électronique de Paris (GeePs), UMR 8507 CNRS-CentraleSupélec, Paris-Sud and UPMC Universities, 11 rue Joliot-Curie, Plateau de Moulon, 91192 Gif-sur-Yvette (France); Delprat, Sophie [Unité Mixte de Physique CNRS-Thales UMR 137, 1 avenue Augustin Fresnel, 91767 Palaiseau (France); UPMC, Université Paris 06, 4 place Jussieu, 75005 Paris (France); Bouzehouane, Karim; Seneor, Pierre; Mattana, Richard [Unité Mixte de Physique CNRS-Thales UMR 137, 1 avenue Augustin Fresnel, 91767 Palaiseau (France); Tatay, Sergio [Molecular Science Institute, University of Valencia, 46980 Paterna (Spain); Geffroy, Bernard [Lab. Physique des Interfaces et Couches minces (PICM), UMR 7647 CNRS-École polytechnique, 91128 Palaiseau (France); Lab. d' Innovation en Chimie des Surfaces et Nanosciences (LICSEN), NIMBE UMR 3685 CNRS-CEA Saclay, 91191 Gif-sur-Yvette (France); and others

    2016-06-13

    An imaging technique associating a slowly intermittent contact mode of atomic force microscopy (AFM) with a home-made multi-purpose resistance sensing device is presented. It aims at extending the widespread resistance measurements classically operated in contact mode AFM to broaden their application fields to soft materials (molecular electronics, biology) and fragile or weakly anchored nano-objects, for which nanoscale electrical characterization is highly demanded and often proves to be a challenging task in contact mode. Compared with the state of the art concerning less aggressive solutions for AFM electrical imaging, our technique brings a significantly wider range of resistance measurement (over 10 decades) without any manual switching, which is a major advantage for the characterization of materials with large on-sample resistance variations. After describing the basics of the set-up, we report on preliminary investigations focused on academic samples of self-assembled monolayers with various thicknesses as a demonstrator of the imaging capabilities of our instrument, from qualitative and semi-quantitative viewpoints. Then two application examples are presented, regarding an organic photovoltaic thin film and an array of individual vertical carbon nanotubes. Both attest the relevance of the technique for the control and optimization of technological processes.

  12. Evaluation of Visunex Medical's PanoCam(TM) LT and PanoCam(TM) Pro wide-field imaging systems for the screening of ROP in newborn infants.

    Science.gov (United States)

    Wood, Edward H; Moshfeghi, Andrew A; Nudleman, Eric D; Moshfeghi, Darius M

    2016-08-01

    Retinopathy of Prematurity (ROP) is a leading cause of childhood blindness. The incidence of ROP is rising, placing greater demands on the healthcare providers that serve these patients and their families. Telemedicine remote digital fundus imaging (TM-RDFI) plays a pivotal role in ROP management, and has allowed for the expansion of ROP care into previously underserved areas. A broad literature review through the pubmed index was undertaken with the goal of summarizing the current state of ROP and guidelines for its screening . Furthermore, all currently used telemedicine remote digital fundus imaging devices were analyzed both via the literature and the companies' websites/brochures. Finally, the PanoCam LT™ and PanoCam™ Pro created by Visunex Medical were analyzed via the company website/brochures. Expert commentary: The PanoCam LT™ and PanoCam™ Pro have recently been approved for use within the USA and CE marked for international commercialization in European Union and other countries requiring CE mark. These wide-field imaging systems have the intended use of ophthalmic imaging of all newborn babies and meet the requirements for ROP screening, thereby serving as competition within the ROP screening market previously dominated by one camera imaging system.

  13. The FLARE mission: deep and wide-field 1-5um imaging and spectroscopy for the early universe: a proposal for M5 cosmic vision call

    Science.gov (United States)

    Burgarella, D.; Levacher, P.; Vives, S.; Dohlen, K.; Pascal, S.

    2016-07-01

    FLARE (First Light And Reionization Explorer) is a space mission that will be submitted to ESA (M5 call). Its primary goal (~80% of lifetime) is to identify and study the universe before the end of the reionization at z > 6. A secondary objective (~20% of lifetime) is to survey star formation in the Milky Way. FLARE's strategy optimizes the science return: imaging and spectroscopic integral-field observations will be carried out simultaneously on two parallel focal planes and over very wide instantaneous fields of view. FLARE will help addressing two of ESA's Cosmic Vision themes: a) universe originate and what is it made of? » and b) « What are the conditions for planet formation and the emergence of life? >> and more specifically, >. FLARE will provide to the ESA community a leading position to statistically study the early universe after JWST's deep but pin-hole surveys. Moreover, the instrumental development of wide-field imaging and wide-field integral-field spectroscopy in space will be a major breakthrough after making them available on ground-based telescopes.

  14. Reconsidering the advantages of the three-dimensional representation of the interferometric transform for imaging with non-coplanar baselines and wide fields of view

    Science.gov (United States)

    Smith, D. M. P.; Young, A.; Davidson, D. B.

    2017-07-01

    Radio telescopes with baselines that span thousands of kilometres and with fields of view that span tens of degrees have been recently deployed, such as the Low Frequency Array, and are currently being developed, such as the Square Kilometre Array. Additionally, there are proposals for space-based instruments with all-sky imaging capabilities, such as the Orbiting Low Frequency Array. Such telescopes produce observations with three-dimensional visibility distributions and curved image domains. In most work to date, the visibility distribution has been converted to a planar form to compute the brightness map using a two-dimensional Fourier transform. The celestial sphere is faceted in order to counter pixel distortion at wide angles, with each such facet requiring a unique planar form of the visibility distribution. Under the above conditions, the computational and storage complexities of this approach can become excessive. On the other hand, when using the direct Fourier transform approach, which maintains the three-dimensional shapes of the visibility distribution and celestial sphere, the non-coplanar visibility component requires no special attention. Furthermore, as the celestial samples are placed directly on the curved surface of the celestial sphere, pixel distortion at wide angles is avoided. In this paper, a number of examples illustrate that under these conditions (very long baselines and very wide fields of view) the costs of the direct Fourier transform may be comparable to (or even lower than) methods that utilise the two-dimensional fast Fourier transform.

  15. A compact wide-range spectrometer with image intensifier: unexpected advantages, new functions, and a variety of applications.

    Science.gov (United States)

    Protopopov, Vladimir

    2012-05-01

    Gated intensified spectrometers are very efficient instruments not only in time-resolved applications but also in all other fields were traditional non-gated and non-intensified devices are so popular today. This paper describes the design and performance of a simple, reliable, and relatively inexpensive wide-range gated intensified spectrometer that was conceived as a prototype for volume production. With 200-900 nm spectral range, 3 ns temporal resolution, variable optical gain up to 4000, repetition rate up to 200 kHz, spectral resolution 2 nm (0.9 nm with deconvolution), and affordable price, such a device may be useful for budget research laboratories working in the fields of cell biology, laser-induced breakdown spectroscopy, molecular kinetics, plasma diagnostics, materials characterization, combustion analysis, and forensic analysis.

  16. Deep wide-field imaging down to the oldest main sequence turn-offs in the Sculptor dwarf spheroidal galaxy

    Science.gov (United States)

    de Boer, T. J. L.; Tolstoy, E.; Saha, A.; Olsen, K.; Irwin, M. J.; Battaglia, G.; Hill, V.; Shetrone, M. D.; Fiorentino, G.; Cole, A.

    2011-04-01

    We present wide-field photometry of resolved stars in the nearby Sculptor dwarf spheroidal galaxy using CTIO/MOSAIC, going down to the oldest main sequence turn-off. The accurately flux calibrated wide field colour-magnitude diagrams can be used to constrain the ages of different stellar populations, and also their spatial distribution. The Sculptor dSph contains a predominantly ancient stellar population (>10 Gyr old) which can be easily resolved into individual stars. A galaxy dominated by an old population provides a clear view of ancient processes of galaxy formation unimpeded by overlying younger populations. By using spectroscopic metallicities of RGB stars in combination with our deep main sequence turn-off photometry we can constrain the ages of different stellar populations with particular accuracy. We find that the known metallicity gradient in Sculptor is well matched to an age gradient. This is the first time that this link with age has been directly quantified. This gradient has been previously observed as a variation in horizontal branch properties and is now confirmed to exist for main sequence turn-offs as well. It is likely the Sculptor dSph first formed an extended metal-poor population at the oldest times, and subsequent more metal-rich, younger stars were formed more towards the centre until the gas was depleted or lost roughly 7 Gyr ago. The fact that these clear radial gradients have been preserved up to the present day is consistent with the apparent lack of signs of recent tidal interactions. Appendices are only available in electronic form at http://www.aanda.org

  17. Analog Encoding Voltage—A Key to Ultra-Wide Dynamic Range and Low Power CMOS Image Sensor

    Directory of Open Access Journals (Sweden)

    Orly Yadid-Pecht

    2013-03-01

    Full Text Available Usually Wide Dynamic Range (WDR sensors that autonomously adjust their integration time to fit intra-scene illumination levels use a separate digital memory unit. This memory contains the data needed for the dynamic range. Motivated by the demands for low power and chip area reduction, we propose a different implementation of the aforementioned WDR algorithm by replacing the external digital memory with an analog in-pixel memory. This memory holds the effective integration time represented by analog encoding voltage (AEV. In addition, we present a “ranging” scheme of configuring the pixel integration time in which the effective integration time is configured at the first half of the frame. This enables a substantial simplification of the pixel control during the rest of the frame and thus allows for a significantly more remarkable DR extension. Furthermore, we present the implementation of “ranging” and AEV concepts on two different designs, which are targeted to reach five and eight decades of DR, respectively. We describe in detail the operation of both systems and provide the post-layout simulation results for the second solution. The simulations show that the second design reaches DR up to 170 dBs. We also provide a comparative analysis in terms of the number of operations per pixel required by our solution and by other widespread WDR algorithms. Based on the calculated results, we conclude that the proposed two designs, using “ranging” and AEV concepts, are attractive, since they obtain a wide dynamic range at high operation speed and low power consumption.

  18. Reflection, phase and en- face sectional imaging of scattering objects using quasi-single-shot wide-field optical coherence tomography

    Science.gov (United States)

    Anna, Tulsi; Kimura, Satoshi; Mehta, Dalip Singh; Sato, Manabu

    2015-10-01

    We report a quasi-single-shot wide-field optical coherence tomography system that enables to measure the reflection, phase and en- face OCT images from the same setup using the glass jig. The jig consisting of a wedge glass substrate and a glue dot is contacted to the tissue surfaces, and the data within glue dot is used to reduce the phase noise of the interference signal. The reconstructed image size of the object was 4.0 mm × 4.3 mm. The standard deviation (STD) of the phase variation was minimized by 54 % and obtained to be 0.027 rad for the poke tissue. The corresponding STD in optical path length change was measured to be 1.4 nm. The refractive index of the water and poke tissue at the surface is also evaluated as 1.36 and 1.39, respectively, using reflection intensity images. Further, the en- face sectional images of the tissue sample are also measured.

  19. Noncontact and Wide-Field Characterization of the Absorption and Scattering Properties of Apple Fruit Using Spatial-Frequency Domain Imaging

    Science.gov (United States)

    Hu, Dong; Fu, Xiaping; He, Xueming; Ying, Yibin

    2016-12-01

    Spatial-frequency domain imaging (SFDI), as a noncontact, low-cost and wide-field optical imaging technique, offers great potential for agro-product safety and quality assessment through optical absorption (μa) and scattering (μ) property measurements. In this study, a laboratory-based SFDI system was constructed and developed for optical property measurement of fruits and vegetables. The system utilized a digital light projector to generate structured, periodic light patterns and illuminate test samples. The diffuse reflected light was captured by a charge coupled device (CCD) camera with the resolution of 1280 × 960 pixels. Three wavelengths (460, 527, and 630 nm) were selected for image acquisition using bandpass filters in the system. The μa and μ were calculated in a region of interest (ROI, 200 × 300 pixels) via nonlinear least-square fitting. Performance of the system was demonstrated through optical property measurement of ‘Redstar’ apples. Results showed that the system was able to acquire spatial-frequency domain images for demodulation and calculation of the μa and μ. The calculated μa of apple tissue experiencing internal browning (IB) were much higher than healthy apple tissue, indicating that the SFDI technique had potential for IB tissue characterization.

  20. Low-frequency wide-field fluorescence lifetime imaging using a high-power near-infrared light-emitting diode light source.

    Science.gov (United States)

    Gioux, Sylvain; Lomnes, Stephen J; Choi, Hak Soo; Frangioni, John V

    2010-01-01

    Fluorescence lifetime imaging (FLi) could potentially improve exogenous near-infrared (NIR) fluorescence imaging, because it offers the capability of discriminating a signal of interest from background, provides real-time monitoring of a chemical environment, and permits the use of several different fluorescent dyes having the same emission wavelength. We present a high-power, LED-based, NIR light source for the clinical translation of wide-field (larger than 5 cm in diameter) FLi at frequencies up to 35 MHz. Lifetime imaging of indocyanine green (ICG), IRDye 800-CW, and 3,3(')-diethylthiatricarbocyanine iodide (DTTCI) was performed over a large field of view (10 cm by 7.5 cm) using the LED light source. For comparison, a laser diode light source was employed as a gold standard. Experiments were performed both on the bench by diluting the fluorescent dyes in various chemical environments in Eppendorf tubes, and in vivo by injecting the fluorescent dyes mixed in Matrigel subcutaneously into CD-1 mice. Last, measured fluorescence lifetimes obtained using the LED and the laser diode sources were compared with those obtained using a state-of-the-art time-domain imaging system and with those previously described in the literature. On average, lifetime values obtained using the LED and the laser diode light sources were consistent, exhibiting a mean difference of 3% from the expected values and a coefficient of variation of 12%. Taken together, our study offers an alternative to laser diodes for clinical translation of FLi and explores the use of relatively low frequency modulation for in vivo imaging.

  1. PYM: a new, affordable, image-based method using a Raspberry Pi to phenotype plant leaf area in a wide diversity of environments

    Directory of Open Access Journals (Sweden)

    Benoît Valle

    2017-11-01

    Full Text Available Abstract Background Plant science uses increasing amounts of phenotypic data to unravel the complex interactions between biological systems and their variable environments. Originally, phenotyping approaches were limited by manual, often destructive operations, causing large errors. Plant imaging emerged as a viable alternative allowing non-invasive and automated data acquisition. Several procedures based on image analysis were developed to monitor leaf growth as a major phenotyping target. However, in most proposals, a time-consuming parameterization of the analysis pipeline is required to handle variable conditions between images, particularly in the field due to unstable light and interferences with soil surface or weeds. To cope with these difficulties, we developed a low-cost, 2D imaging method, hereafter called PYM. The method is based on plant leaf ability to absorb blue light while reflecting infrared wavelengths. PYM consists of a Raspberry Pi computer equipped with an infrared camera and a blue filter and is associated with scripts that compute projected leaf area. This new method was tested on diverse species placed in contrasting conditions. Application to field conditions was evaluated on lettuces grown under photovoltaic panels. The objective was to look for possible acclimation of leaf expansion under photovoltaic panels to optimise the use of solar radiation per unit soil area. Results The new PYM device proved to be efficient and accurate for screening leaf area of various species in wide ranges of environments. In the most challenging conditions that we tested, error on plant leaf area was reduced to 5% using PYM compared to 100% when using a recently published method. A high-throughput phenotyping cart, holding 6 chained PYM devices, was designed to capture up to 2000 pictures of field-grown lettuce plants in less than 2 h. Automated analysis of image stacks of individual plants over their growth cycles revealed unexpected

  2. PYM: a new, affordable, image-based method using a Raspberry Pi to phenotype plant leaf area in a wide diversity of environments.

    Science.gov (United States)

    Valle, Benoît; Simonneau, Thierry; Boulord, Romain; Sourd, Francis; Frisson, Thibault; Ryckewaert, Maxime; Hamard, Philippe; Brichet, Nicolas; Dauzat, Myriam; Christophe, Angélique

    2017-01-01

    Plant science uses increasing amounts of phenotypic data to unravel the complex interactions between biological systems and their variable environments. Originally, phenotyping approaches were limited by manual, often destructive operations, causing large errors. Plant imaging emerged as a viable alternative allowing non-invasive and automated data acquisition. Several procedures based on image analysis were developed to monitor leaf growth as a major phenotyping target. However, in most proposals, a time-consuming parameterization of the analysis pipeline is required to handle variable conditions between images, particularly in the field due to unstable light and interferences with soil surface or weeds. To cope with these difficulties, we developed a low-cost, 2D imaging method, hereafter called PYM. The method is based on plant leaf ability to absorb blue light while reflecting infrared wavelengths. PYM consists of a Raspberry Pi computer equipped with an infrared camera and a blue filter and is associated with scripts that compute projected leaf area. This new method was tested on diverse species placed in contrasting conditions. Application to field conditions was evaluated on lettuces grown under photovoltaic panels. The objective was to look for possible acclimation of leaf expansion under photovoltaic panels to optimise the use of solar radiation per unit soil area. The new PYM device proved to be efficient and accurate for screening leaf area of various species in wide ranges of environments. In the most challenging conditions that we tested, error on plant leaf area was reduced to 5% using PYM compared to 100% when using a recently published method. A high-throughput phenotyping cart, holding 6 chained PYM devices, was designed to capture up to 2000 pictures of field-grown lettuce plants in less than 2 h. Automated analysis of image stacks of individual plants over their growth cycles revealed unexpected differences in leaf expansion rate between

  3. MUSIC - Multifunctional stereo imaging camera system for wide angle and high resolution stereo and color observations on the Mars-94 mission

    Science.gov (United States)

    Oertel, D.; Jahn, H.; Sandau, R.; Walter, I.; Driescher, H.

    1990-10-01

    Objectives of the multifunctional stereo imaging camera (MUSIC) system to be deployed on the Soviet Mars-94 mission are outlined. A high-resolution stereo camera (HRSC) and wide-angle opto-electronic stereo scanner (WAOSS) are combined in terms of hardware, software, technology aspects, and solutions. Both HRSC and WAOSS are push-button instruments containing a single optical system and focal plates with several parallel CCD line sensors. Emphasis is placed on the MUSIC system's stereo capability, its design, mass memory, and data compression. A 1-Gbit memory is divided into two parts: 80 percent for HRSC and 20 percent for WAOSS, while the selected on-line compression strategy is based on macropixel coding and real-time transform coding.

  4. Direct wide-angle measurement of a photonic band structure in a three-dimensional photonic crystal using infrared Fourier imaging spectroscopy.

    Science.gov (United States)

    Chen, Lifeng; Lopez-Garcia, Martin; Taverne, Mike P C; Zheng, Xu; Ho, Ying-Lung D; Rarity, John

    2017-04-15

    We propose a method to directly visualize the photonic band-structure of micrometer-sized photonic crystals using wide-angle spectroscopy. By extending Fourier imaging spectroscopy sensitivity into the infrared range, we have obtained accurate measurements of the band structures along the high-symmetry directions (X-W-K-L-U) of polymeric three-dimensional, rod-connected diamond photonic crystals. Our implementation also allows us to record single-wavelength reflectance far-field patterns showing very good agreement with simulations of the same designs. This technique is suitable for the characterization of photonic structures working in the infrared and, in particular, to obtain band-structure information of complete photonic band gap materials.

  5. Soft x-ray free-electron laser imaging by LiF crystal and film detectors over a wide range of fluences.

    Science.gov (United States)

    Pikuz, Tatiana A; Faenov, Anatoly Ya; Fukuda, Yuji; Kando, Masaki; Bolton, Paul; Mitrofanov, Alexander; Vinogradov, Alexander V; Nagasono, Mitsuru; Ohashi, Haruhiko; Yabashi, Makina; Tono, Kensuke; Senba, Yasunori; Togashi, Tadashi; Ishikawa, Tetsuya

    2013-01-20

    LiF crystal and film detectors were used to measure the far-field fluence profile of a self-amplified spontaneous-emission free-electron laser beam and diffraction imaging with high spatial resolution. In these measurements the photoluminescence (PL) response of LiF crystal and film was compared over a wide range of soft x-ray fluences. It was found that the soft x-ray fluence dependences of LiF crystal and film differ. At low fluence, the LiF crystal shows higher PL response compared to LiF film, while this comparison is the opposite at higher fluence. Accurate measurement of LiF crystal and film PL response is important for precise characterization of the spatial, spectral, and coherence features of x-ray beams across the full profile and in localized areas. For such measurements, crucial LiF detector attributes are high spatial resolution and high dynamic range.

  6. Deep K-band Observations of TMC-1 with the Green Bank Telescope: Detection of HC7O, Nondetection of HC11N, and a Search for New Organic Molecules

    Science.gov (United States)

    Cordiner, M. A.; Charnley, S. B.; Kisiel, Z.; McGuire, B. A.; Kuan, Y.-J.

    2017-12-01

    The 100 m Robert C. Byrd Green Bank Telescope K-band (KFPA) receiver was used to perform a high-sensitivity search for rotational emission lines from complex organic molecules in the cold interstellar medium toward TMC-1 (cyanopolyyne peak), focussing on the identification of new carbon-chain-bearing species as well as molecules of possible prebiotic relevance. We report a detection of the carbon-chain oxide species HC7O and derive a column density of (7.8+/- 0.9)× {10}11 cm-2. This species is theorized to form as a result of associative electron detachment reactions between oxygen atoms and C7H-, and/or reaction of C6H2 + with CO (followed by dissociative electron recombination). Upper limits are given for the related HC6O, C6O, and C7O molecules. In addition, we obtained the first detections of emission from individual 13C isotopologues of HC7N, and derive abundance ratios HC7N/HCCC13CCCCN = 110 ± 16 and HC7N/HCCCC13CCCN = 96 ± 11, indicative of significant 13C depletion in this species relative to the local interstellar elemental 12C/13C ratio of 60-70. The observed spectral region covered two transitions of HC11N, but emission from this species was not detected, and the corresponding column density upper limit is 7.4× {10}10 {{cm}}-2 (at 95% confidence). This is significantly lower than the value of 2.8× {10}11 {{cm}}-2 previously claimed by Bell et al. and confirms the recent nondetection of HC11N in TMC-1 by Loomis et al. Upper limits were also obtained for the column densities of malononitrile and the nitrogen heterocycles quinoline, isoquinoline, and pyrimidine.

  7. Wide area Hyperspectral Motion Imaging

    Science.gov (United States)

    2017-02-03

    digital focal plane array (bottom of Figure 1), each pixel has an analog-to- digital converter ( ADC ). The ADC converts the input photocurrent into a...applied. In addition, multiple counters can be connected to the digital bit stream output of the ADC . To decode the three channel example, each...hypercube acquisition. At the DFPA, selected codes or linear combinations of codes can be decoded. This capability can be useful for decoding only

  8. Microneedles rollers as a potential device to increase ALA diffusion and PpIX production: evaluations by wide-field fluorescence imaging and fluorescence spectroscopy

    Science.gov (United States)

    Gracielli Sousa, R. Phamilla; de Menezes, Priscila F. C.; Fujita, Alessandra K. L.; Requena, Michelle B.; Govone, Angelo Biassi; Escobar, André; de Nardi, Andrigo B.; Kurachi, Cristina; Bagnato, Vanderlei Salvador

    2014-03-01

    One of the limitations of topical photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA) is the poor ability to penetrate biological barriers of skin and the recurrence rates in treatments. This study aimed to identify possible signs of increased diffusion of ALA-induced PpIX by fluorescence images and fluorescence spectroscopy. The research was done using in vivo porcine skin model. Before the cream application, microholes was performed with microneedles rollers in only one direction, afterward the ALA cream was applied at a 2.5cm2 area in triplicate and an occlusive dressing was placed. PpIX production was monitored using fluorescence spectroscopy collected at skin surface after 70, 100, 140, and 180 minutes of ALA incubation. About 100 fluorescence spectra of each treatment were collected, distributed by about five points for each site. Wide-field fluorescence imaging was made after 70, 90, and 170 minutes after treatment. The results obtained by imaging analysis indicated increase of the PpIX diffusion in the skin surface using the microneedles rollers (MNs) before ALA application. Circular regions of red fluorescence around the microholes were observed. In addition, the fluorescence spectra showed a greater intensity (2 times as many) in groups microneedles rollers associated. In conclusion, our data shown greater homogeneity and PpIX production in the groups pre-treated with microneedles indicating that the technique can be used to greater uniformity of PpIX production throughout the area to be treated reducing the chances of recurrent tumor as well as has potential for decreasing the time of therapy. (FUNDING SUPPORT:CAPES, CNPq and FAPESP)

  9. Flight performance of an advanced CZT imaging detector in a balloon-borne wide-field hard X-ray telescope—ProtoEXIST1

    Science.gov (United States)

    Hong, J.; Allen, B.; Grindlay, J.; Barthelemy, S.; Baker, R.; Garson, A.; Krawczynski, H.; Apple, J.; Cleveland, W. H.

    2011-10-01

    We successfully carried out the first high-altitude balloon flight of a wide-field hard X-ray coded-aperture telescope ProtoEXIST1, which was launched from the Columbia Scientific Balloon Facility at Ft. Sumner, New Mexico on October 9, 2009. ProtoEXIST1 is the first implementation of an advanced CdZnTe (CZT) imaging detector in our ongoing program to establish the technology required for next generation wide-field hard X-ray telescopes such as the High Energy Telescope (HET) in the Energetic X-ray Imaging Survey Telescope (EXIST). The CZT detector plane in ProtoEXIST1 consists of an 8×8 array of closely tiled 2 cm×2 cm×0.5 cm thick pixellated CZT crystals, each with 8×8 pixels, mounted on a set of readout electronics boards and covering a 256 cm2 active area with 2.5 mm pixels. A tungsten mask, mounted at 90 cm above the detector provides shadowgrams of X-ray sources in the 30-600 keV band for imaging, allowing a fully coded field of view of 9°×9° (and 19°×19° for 50% coding fraction) with an angular resolution of 20‧. In order to reduce the background radiation, the detector is surrounded by semi-graded (Pb/Sn/Cu) passive shields on the four sides all the way to the mask. On the back side, a 26 cm×26 cm×2 cm CsI(Na) active shield provides signals to tag charged particle induced events as well as ≳100keV background photons from below. The flight duration was only about 7.5 h due to strong winds (60 knots) at float altitude (38-39 km). Throughout the flight, the CZT detector performed excellently. The telescope observed Cyg X-1, a bright black hole binary system, for ˜1h at the end of the flight. Despite a few problems with the pointing and aspect systems that caused the telescope to track about 6.4° off the target, the analysis of the Cyg X-1 data revealed an X-ray source at 7.2σ in the 30-100 keV energy band at the expected location from the optical images taken by the onboard daytime star camera. The success of this first flight is very

  10. Gemini Frontier Fields: Wide-field Adaptive Optics Ks-band Imaging of the Galaxy Clusters MACS J0416.1-2403 and Abell 2744

    Science.gov (United States)

    Schirmer, M.; Carrasco, E. R.; Pessev, P.; Garrel, V.; Winge, C.; Neichel, B.; Vidal, F.

    2015-04-01

    We have observed two of the six Frontier Fields galaxy clusters, MACS J0416.1-2403 and Abell 2744, using the Gemini Multi-Conjugate Adaptive Optics System (GeMS) and the Gemini South Adaptive Optics Imager (GSAOI). With 0.″ 08-0.″ 10 FWHM our data are nearly diffraction-limited over a 100\\prime\\prime × 100\\prime\\prime wide area. GeMS/GSAOI complements the Hubble Space Telescope (HST) redwards of 1.6 μm with twice the angular resolution. We reach a 5σ depth of {{K}s}˜ 25.6 mag (AB) for compact sources. In this paper, we describe the observations, data processing, and initial public data release. We provide fully calibrated, co-added images matching the native GSAOI pixel scale as well as the larger plate scales of the HST release, adding to the legacy value of the Frontier Fields. Our work demonstrates that even for fields at high galactic latitude where natural guide stars are rare, current multi-conjugated adaptive optics technology at 8 m telescopes has opened a new window on the distant universe. Observations of a third Frontier Field, Abell 370, are planned. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência, Tecnologia e Inovação (Brazil) and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina). Based on observations made with ESO Telescopes at the La Silla and Paranal Observatories, Chile.

  11. A Wide-Field Fluorescence Microscope Extension for Ultrafast Screening of One-Bead One-Compound Libraries Using a Spectral Image Subtraction Approach.

    Science.gov (United States)

    Heusermann, Wolf; Ludin, Beat; Pham, Nhan T; Auer, Manfred; Weidemann, Thomas; Hintersteiner, Martin

    2016-05-09

    The increasing involvement of academic institutions and biotech companies in drug discovery calls for cost-effective methods to identify new bioactive molecules. Affinity-based on-bead screening of combinatorial one-bead one-compound libraries combines a split-mix synthesis design with a simple protein binding assay operating directly at the bead matrix. However, one bottleneck for academic scale on-bead screening is the unavailability of a cheap, automated, and robust screening platform that still provides a quantitative signal related to the amount of target protein binding to individual beads for hit bead ranking. Wide-field fluorescence microscopy has long been considered unsuitable due to significant broad spectrum autofluorescence of the library beads in conjunction with low detection sensitivity. Herein, we demonstrate how such a standard microscope equipped with LED-based excitation and a modern CMOS camera can be successfully used for selecting hit beads. We show that the autofluorescence issue can be overcome by an optical image subtraction approach that yields excellent signal-to-noise ratios for the detection of bead-associated target proteins. A polymer capillary attached to a semiautomated bead-picking device allows the operator to efficiently isolate individual hit beads in less than 20 s. The system can be used for ultrafast screening of >200,000 bead-bound compounds in 1.5 h, thereby making high-throughput screening accessible to a wider group within the scientific community.

  12. Optimizing ultrafast wide field-of-view illumination for high-throughput multi-photon imaging and screening of mutant fluorescent proteins

    Science.gov (United States)

    Stoltzfus, Caleb; Mikhailov, Alexandr; Rebane, Aleksander

    2017-02-01

    Fluorescence induced by 1wo-photon absorption (2PA) and three-photon absorption (3PA) is becoming an increasingly important tool for deep-tissue microscopy, especially in conjunction with genetically-encoded functional probes such as fluorescent proteins (FPs). Unfortunately, the efficacy of the multi-photon excitation of FPs is notoriously low, and because relations between a biological fluorophore's nonlinear-optical properties and its molecular structure are inherently complex, there are no practical avenues available that would allow boosting the performance of current FPs. Here we describe a novel method, where we apply directed evolution to optimize the 2PA properties of EGFP. Key to the success of this approach consists in high-throughput screening of mutants that would allow selection of variants with promising 2PA and 3PA properties in a broad near-IR excitation range of wavelength. For this purpose, we construct and test a wide field-of-view (FOV), femtosecond imaging system that we then use to quantify the multi-photon excited fluorescence in the 550- 1600 nm range of tens of thousands of E. coli colonies expressing randomly mutated FPs in a standard 10 cm diameter Petri dish configuration. We present a quantitative analysis of different factors that are currently limiting the maximum throughput of the femtosecond multi-photon screening techniques and also report on quantitative measurement of absolute 2PA and 3PA cross sections spectra.

  13. Wide beam reconstruction "quarter-time" gated myocardial perfusion SPECT functional imaging: a comparison to "full-time" ordered subset expectation maximum.

    Science.gov (United States)

    DePuey, E Gordon; Bommireddipalli, Srinivas; Clark, John; Thompson, Linda; Srour, Yossi

    2009-01-01

    Previously we reported that compared to iterative reconstruction with ordered subset expectation maximum (OSEM), wide beam reconstruction (WBR), which incorporates resolution recovery and controls noise during reconstruction without applying a post-processing filter, allows half-time SPECT acquisition with preserved diagnostic quality. We now postulate that with further Poisson noise treatment, quarter-time acquisition is possible. The half-time WBR algorithm was optimized for quarter-time acquisition based upon anthropomorphic cardiac phantom data and a pilot group of 48 patients (pts). Then using the modified algorithm, 209 pts (91 men, 118 women, mean chest circumference = 40 in) were imaged at rest (R) and stress (S) (9/32 mCi (99m)Tc-sestamibi) full-time with OSEM, and again quarter-time with the modified WBR algorithm. The 180 degrees , 64-stop, full-time single-day rest (R) (25 second-per-stop, sps) and 8-frame per cardiac cycle post-stress (S) (20 sps) gated SPECT, and then quarter-time R (6 sps) and post-S (4 sps) gated SPECT were acquired. Blinded observers graded scan quality (1 = poor to 5 = excellent) based on myocardial uniformity, endocardial/epicardial edge definition, and background noise. Perfusion defects were scored using a 17-segment model. Using three commercially available software methods, end-diastolic volume (EDV), end-systolic volume (ESV), and left ventricular ejection fraction (LVEF) were calculated. For the 209 prospective pts, mean image quality for R full-time OSEM and quarter-time WBR were similar (3.5 +/- 0.9 vs 3.6 +/- 0.7, p NS). For S, quarter-time WBR quality was superior to full-time OSEM (4.3 +/- 0.7 vs 3.9 +/- 0.7) (P = 1.78 x 10(-17)). In 35 pts with chest circumferences >44 inches a longer, 10 sps WBR acquisition improved resting image quality. Of 48 pts with abnormal scans (SSSs > 2 by OSEM) mean summed stress scores, summed rest scores, and summed difference scores were not significantly different with quarter-time WBR

  14. Images

    Data.gov (United States)

    National Aeronautics and Space Administration — Images for the website main pages and all configurations. The upload and access points for the other images are: Website Template RSW images BSCW Images HIRENASD...

  15. NEAR-INFRARED IMAGING OF A z = 6.42 QUASAR HOST GALAXY WITH THE HUBBLE SPACE TELESCOPE WIDE FIELD CAMERA 3

    Energy Technology Data Exchange (ETDEWEB)

    Mechtley, M.; Windhorst, R. A.; Cohen, S. H.; Jansen, R. A.; Scannapieco, E. [School of Earth and Space Exploration, Arizona State University, P.O. Box 871404, Tempe, AZ 85287 (United States); Ryan, R. E.; Koekemoer, A. M. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Schneider, G.; Fan, X. [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Hathi, N. P. [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Keel, W. C. [Department of Physics and Astronomy, University of Alabama, Box 870324, Tuscaloosa, AL 35487 (United States); Roettgering, H. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA, Leiden (Netherlands); Schneider, D. P. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States); Strauss, M. A. [Princeton University Observatory, Princeton, NJ 08544 (United States); Yan, H. J. [Department of Physics and Astronomy, The University of Missouri, 701 South College Ave, Columbia, MO 65211 (United States)

    2012-09-10

    We report on deep near-infrared F125W (J) and F160W (H) Hubble Space Telescope Wide Field Camera 3 images of the z = 6.42 quasar J1148+5251 to attempt to detect rest-frame near-ultraviolet emission from the host galaxy. These observations included contemporaneous observations of a nearby star of similar near-infrared colors to measure temporal variations in the telescope and instrument point-spread function (PSF). We subtract the quasar point source using both this direct PSF and a model PSF. Using direct subtraction, we measure an upper limit for the quasar host galaxy of m{sub J} > 22.8 and m{sub H} > 23.0 AB mag (2 {sigma}). After subtracting our best model PSF, we measure a limiting surface brightness from 0.''3 to 0.''5 radius of {mu}{sub J} > 23.5 and {mu}{sub H} > 23.7 AB mag arcsec{sup -2} (2 {sigma}). We test the ability of the model subtraction method to recover the host galaxy flux by simulating host galaxies with varying integrated magnitude, effective radius, and Sersic index, and conducting the same analysis. These models indicate that the surface brightness limit ({mu}{sub J} > 23.5 AB mag arcsec{sup -2}) corresponds to an integrated upper limit of m{sub J} > 22-23 AB mag, consistent with the direct subtraction method. Combined with existing far-infrared observations, this gives an infrared excess log (IRX) > 1.0 and corresponding ultraviolet spectral slope {beta} > -1.2 {+-} 0.2. These values match those of most local luminous infrared galaxies, but are redder than those of almost all local star-forming galaxies and z {approx_equal} 6 Lyman break galaxies.

  16. Invited Article: First Flight in Space of a Wide-field-of-view Soft X-Ray Imager Using Lobster-Eye Optics: Instrument Description and Initial Flight Results

    Science.gov (United States)

    Collier, Michael; Porter, F. Scott; Sibeck, David G.; Carter, Jenny A.; Chiao, Meng P.; Chomay, Dennis J.; Cravens, Thomas E.; Galeazzi, Massiniliano; Keller, John; Koutroumpa, Dimitra

    2015-01-01

    We describe the development, launch into space, and initial results from a prototype wide eld-of-view (FOV) soft X-ray imager that employs Lobster-eye optics and targets heliophysics, planetary, and astrophysics science. The Sheath Transport Observer for the Redistribution of Mass (STORM) is the rst instrument using this type of optics launched into space and provides proof-of-concept for future ight instruments capable of imaging structures such as the terrestrial cusp, the entire dayside magnetosheath from outside the magnetosphere, comets, the moon, and the solar wind interaction with planetary bodies like Venus and Mars.

  17. Invited Article: First flight in space of a wide-field-of-view soft x-ray imager using lobster-eye optics: Instrument description and initial flight results.

    Science.gov (United States)

    Collier, Michael R; Porter, F Scott; Sibeck, David G; Carter, Jenny A; Chiao, Meng P; Chornay, Dennis J; Cravens, Thomas E; Galeazzi, Massimiliano; Keller, John W; Koutroumpa, Dimitra; Kujawski, Joseph; Kuntz, Kip; Read, Andy M; Robertson, Ina P; Sembay, Steve; Snowden, Steven L; Thomas, Nicholas; Uprety, Youaraj; Walsh, Brian M

    2015-07-01

    We describe the development, launch into space, and initial results from a prototype wide field-of-view soft X-ray imager that employs lobster-eye optics and targets heliophysics, planetary, and astrophysics science. The sheath transport observer for the redistribution of mass is the first instrument using this type of optics launched into space and provides proof-of-concept for future flight instruments capable of imaging structures such as the terrestrial cusp, the entire dayside magnetosheath from outside the magnetosphere, comets, the Moon, and the solar wind interaction with planetary bodies like Venus and Mars [Kuntz et al., Astrophys. J. (in press)].

  18. Metamaterial Apertures for Computational Imaging

    Science.gov (United States)

    Hunt, John; Driscoll, Tom; Mrozack, Alex; Lipworth, Guy; Reynolds, Matthew; Brady, David; Smith, David R.

    2013-01-01

    By leveraging metamaterials and compressive imaging, a low-profile aperture capable of microwave imaging without lenses, moving parts, or phase shifters is demonstrated. This designer aperture allows image compression to be performed on the physical hardware layer rather than in the postprocessing stage, thus averting the detector, storage, and transmission costs associated with full diffraction-limited sampling of a scene. A guided-wave metamaterial aperture is used to perform compressive image reconstruction at 10 frames per second of two-dimensional (range and angle) sparse still and video scenes at K-band (18 to 26 gigahertz) frequencies, using frequency diversity to avoid mechanical scanning. Image acquisition is accomplished with a 40:1 compression ratio.

  19. Observations and Modeling of Solar Coronal Structures Using High-Resolution Eclipse Images and Space-based Telescopes with Wide Field of View

    Science.gov (United States)

    Lu, Muzhou; Pasachoff, J. M.; Su, Y.; Van Ballegooijen, A. A.; Seaton, D. B.; West, M.

    2013-07-01

    We present a comparison of the solar corona observed during the total solar eclipses on 2010 July 11 and on 2012 November 13. The white light images were taken at Easter Island in 2010 and at Northeast Queensland, Australia, in 2012; while the concurrent EUV images were take with SDO/AIA and PROBA2/SWAP. The 2010 eclipse was observed at the beginning of Sunspot Cycle 24 [1], which peaked near our 2012 observation. We compare a plethora of corona features in the white light images and reveal some interesting differences in the enhanced EUV images taken by SDO/AIA and PROBA2/SWAP. We construct potential field models using our newly refined Coronal Modeling System (CMS2) software with line-of-sight photospheric magnetograms from SDO/HMI. The source surface heights derived from detailed comparison between our models and observations are compared to the standard source-surface model. We also compare the dynamics of the two eclipse observations. Similar to the 2010 eclipse, a CME was observed using temporally spaced eclipse images. We address unresolved problems in the models and observations with the hope of correcting them for future eclipse observations, such as the 2017 total solar eclipse across the continental U.S. References [1] Pasachoff, J. M., Rusin, V., Druckmüllerová, H., Saniga, M., Lu, M., Malamut, C., Seaton, D. B., Golub, L., Engell, A. J., Hill, S. W., Lucas, R., 2011, ApJ, 734, 114

  20. Comparison of glomerular activity patterns by fMRI and wide-field calcium imaging: implications for principles underlying odor mapping

    Science.gov (United States)

    Sanganahalli, Basavaraju G.; Rebello, Michelle R.; Herman, Peter; Papademetris, Xenophon; Shepherd, Gordon M.; Verhagen, Justus V.; Hyder, Fahmeed

    2015-01-01

    Functional imaging signals arise from distinct metabolic and hemodynamic events at the neuropil, but how these processes are influenced by pre- and post-synaptic activities need to be understood for quantitative interpretation of stimulus-evoked mapping data. The olfactory bulb (OB) glomeruli, spherical neuropil regions with well-defined neuronal circuitry, can provide insights into this issue. Optical calcium-sensitive fluorescent dye imaging (OICa2+) reflects dynamics of pre-synaptic input to glomeruli, whereas high-resolution functional magnetic resonance imaging (fMRI) using deoxyhemoglobin contrast reveals neuropil function within the glomerular layer where both pre- and post-synaptic activities contribute. We imaged odor-specific activity patterns of the dorsal OB in the same anesthetized rats with fMRI and OICa2+ and then co-registered the respective maps to compare patterns in the same space. Maps by each modality were very reproducible as trial-to-trial patterns for a given odor, overlapping by ~80%. Maps evoked by ethyl butyrate and methyl valerate for a given modality overlapped by ~80%, suggesting activation of similar dorsal glomerular networks by these odors. Comparison of maps generated by both methods for a given odor showed ~70% overlap, indicating similar odor-specific maps by each method. These results suggest that odor-specific glomerular patterns by high-resolution fMRI primarily tracks pre-synaptic input to the OB. Thus combining OICa2+ and fMRI lays the framework for studies of OB processing over a range of spatiotemporal scales, where OICa2+ can feature the fast dynamics of dorsal glomerular clusters and fMRI can map the entire glomerular sheet in the OB. PMID:26631819

  1. Constraints on the Progenitor System of the Type Ia Supernova 2014J from Pre-Explosion Hubble Space Telescope Imaging

    Science.gov (United States)

    Kelly, Patrick L.; Fox, Ori D.; Filippenko, Alexei V.; Cenko, S. Bradley; Prato, Lisa; Schaefer, Gail; Shen, Ken J.; Zheng, WeiKang; Graham, Melissa L.; Tucker, Brad E.

    2014-01-01

    We constrain the properties of the progenitor system of the highly reddened Type Ia supernova (SN Ia) 2014J in Messier 82 (M82; d (is) approx. 3.5 Mpc). We determine the supernova (SN) location using Keck-II K-band adaptive optics images, and we find no evidence for flux from a progenitor system in pre-explosion near-ultraviolet through near-infrared Hubble Space Telescope (HST) images. Our upper limits exclude systems having a bright red giant companion, including symbiotic novae with luminosities comparable to that of RS Ophiuchi. While the flux constraints are also inconsistent with predictions for comparatively cool He-donor systems (T (is) approximately 35,000 K), we cannot preclude a system similar to V445 Puppis. The progenitor constraints are robust across a wide range of RV and AV values, but significantly greater values than those inferred from the SN light curve and spectrum would yield proportionally brighter luminosity limits. The comparatively faint flux expected from a binary progenitor system consisting of white dwarf stars would not have been detected in the pre-explosion HST imaging. Infrared HST exposures yield more stringent constraints on the luminosities of very cool (T (is) less than 3000 K) companion stars than was possible in the case of SN Ia 2011fe.

  2. Simulations of the x-ray imaging capabilities of the silicon drift detectors (SDD) for the LOFT wide-field monitor

    DEFF Research Database (Denmark)

    Evangelista, Y.; Campana, R.; Del Monte, E.

    2012-01-01

    The Large Observatory For X-ray Timing (LOFT), selected by ESA as one of the four Cosmic Vision M3 candidate missions to undergo an assessment phase, will revolutionize the study of compact objects in our galaxy and of the brightest supermassive black holes in active galactic nuclei. The Large Area...... Detector (LAD), carrying an unprecedented effective area of 10 m^2, is complemented by a coded-mask Wide Field Monitor, in charge of monitoring a large fraction of the sky potentially accessible to the LAD, to provide the history and context for the sources observed by LAD and to trigger its observations...

  3. Assessment of Gastric Accommodation in Patients with Functional Dyspepsia by 99mTc-Pertechtenate Single Photon Emission Computed Tomography Imaging: Practical but not Widely Accepted

    Directory of Open Access Journals (Sweden)

    Taghi Amiriani

    2015-10-01

    Full Text Available Objective: Impaired gastric accommodation is one of the main symptoms in patients with functional dyspepsia. The aim of the present study was to assess gastric accommodation in patients with functional dyspepsia using single photon emission computed tomography (SPECT imaging. Methods: Twenty-four patients with functional dyspepsia and 50 healthy volunteers as control group were enrolled in this study. All participants were given 5 mCi 99mTc-pertechtenate intravenously, served with a low fat meal, and underwent SPECT scanning 20 minutes after the meal. Results: Based on the scintigraphic data, gastric volumes were found to be significantly increased after food ingestion in both patient and control groups. We also found that while there was no significant difference between patient and control groups in terms of fasting gastric volumes, postprandial gastric volume was significantly lower in patients as compared to healthy individuals (p<0.05. Conclusion: Measuring gastric volume by using SPECT can be a valuable method in the detection of functional dyspepsia and in differentiation of this entity from other organic disorders.

  4. Reclassification Rates of Patients Eligible for Active Surveillance After the Addition of Magnetic Resonance Imaging-Ultrasound Fusion Biopsy: An Analysis of 7 Widely Used Eligibility Criteria.

    Science.gov (United States)

    Nahar, Bruno; Katims, Andrew; Barboza, Marcelo Panizzutti; Soodana Prakash, Nachiketh; Venkatramani, Vivek; Kava, Bruce; Satyanarayana, Ramgopal; Gonzalgo, Mark L; Ritch, Chad R; Parekh, Dipen J; Punnen, Sanoj

    2017-12-01

    To evaluate the impact of adding magnetic resonance imaging-ultrasound (MRI-US) fusion biopsy cores to standard 12-core biopsy in selecting men for active surveillance (AS). Among men undergoing a fusion biopsy for evaluation of prostate cancer, we selected men who were eligible for at least 1 of 7 different AS criteria based on the standard biopsy alone. We assessed each patient's eligibility for each AS criterion with and without the inclusion of fusion biopsy cores. The primary end point was the proportion of men who were initially eligible for AS but became ineligible after addition of the fusion biopsy cores. A total of 100 men were eligible for at least 1 AS criterion. After addition of fusion biopsy cores, the proportion of men who became ineligible for AS varied from 10.3% to 40.7%. Criteria that incorporated an absolute maximum number of cores positive had the highest rates of ineligibility. Using a percentage of cores positive helped to reduce the number of patients who would have been excluded. Combining the targeted biopsy cores into one, or taking the single core with the highest grade or volume did not appear to reduce the proportion of men who became ineligible. The addition of fusion biopsy to standard 12-core biopsy significantly increased the number of men who became ineligible for AS. Using the percent of cores positive, instead of an absolute number, allowed fewer exclusions. AS criteria may need to be updated to prevent the unnecessary exclusion of men due to an oversampling of low-risk disease. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Effect of Filmless Imaging on Utilization of Radiologic Services with a Two-stage, Hospital-Wide Implementation of a Picture Archiving and Communication System: Initial Experience of a Fee-for-Service Model

    Directory of Open Access Journals (Sweden)

    Yu-Ting Kuo

    2003-02-01

    Full Text Available A medium-sized general hospital using a fee-for-service model implemented a hospital-wide picture archiving and communication system (PACS in two stages. This study evaluated the reporting time with filmless operation and the effect of filmless imaging on referring physicians' use of the radiologic service before and after completion of the second stage of PACS implementation. The relationship between the total number of hospital patients and the number of radiologic department patients was also evaluated. All sample images were retrieved from the PACS. All corresponding reports except for one for a computerized tomography study were available. The median reporting time for different studies performed during working hours was less than 2 hours. There was a significantly positive and linear relationship (p < 0.01 between the total number of hospital patients and the number of radiologic department patients after hospital-wide implementation of PACS. We conclude that the fee-for-service model had no negative impact on referring physicians' use of radiologic services in a filmless hospital.

  6. Images.

    Science.gov (United States)

    Barr, Catherine, Ed.

    1997-01-01

    The theme of this month's issue is "Images"--from early paintings and statuary to computer-generated design. Resources on the theme include Web sites, CD-ROMs and software, videos, books, and others. A page of reproducible activities is also provided. Features include photojournalism, inspirational Web sites, art history, pop art, and myths. (AEF)

  7. Rational Design of Multifunctional Fe@γ-Fe2O3@H-TiO2Nanocomposites with Enhanced Magnetic and Photoconversion Effects for Wide Applications: From Photocatalysis to Imaging-Guided Photothermal Cancer Therapy.

    Science.gov (United States)

    Wang, Meifang; Deng, Kerong; Lü, Wei; Deng, Xiaoran; Li, Kai; Shi, Yanshu; Ding, Binbin; Cheng, Ziyong; Xing, Bengang; Han, Gang; Hou, Zhiyao; Lin, Jun

    2018-02-14

    Titanium dioxide (TiO 2 ) has been widely investigated and used in many areas due to its high refractive index and ultraviolet light absorption, but the lack of absorption in the visible-near infrared (Vis-NIR) region limits its application. Herein, multifunctional Fe@γ-Fe 2 O 3 @H-TiO 2 nanocomposites (NCs) with multilayer-structure are synthesized by one-step hydrogen reduction, which show remarkably improved magnetic and photoconversion effects as a promising generalists for photocatalysis, bioimaging, and photothermal therapy (PTT). Hydrogenation is used to turn white TiO 2 in to hydrogenated TiO 2 (H-TiO 2 ), thus improving the absorption in the Vis-NIR region. Based on the excellent solar-driven photocatalytic activities of the H-TiO 2 shell, the Fe@γ-Fe 2 O 3 magnetic core is introduced to make it convenient for separating and recovering the catalytic agents. More importantly, Fe@γ-Fe 2 O 3 @H-TiO 2 NCs show enhanced photothermal conversion efficiency due to more circuit loops for electron transitions between H-TiO 2 and γ-Fe 2 O 3 , and the electronic structures of Fe@γ-Fe 2 O 3 @H-TiO 2 NCs are calculated using the Vienna ab initio simulation package based on the density functional theory to account for the results. The reported core-shell NCs can serve as an NIR-responsive photothermal agent for magnetic-targeted photothermal therapy and as a multimodal imaging probe for cancer including infrared photothermal imaging, magnetic resonance imaging, and photoacoustic imaging. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. K-Band Radio frequency Interference Survey of Southeastern Michigan

    DEFF Research Database (Denmark)

    Curry, Shannon; Ahlers, Michael Faursby; Elliot, Harvey

    2010-01-01

    The Radio frequency Interference Survey of Earth (RISE) is a new type of instrument used to survey and characterize the presence of Radio Frequency Interference (RFI) that can affect microwave radiometers. It consists of a combined microwave radiometer and kurtosis spectrometer with broad frequency...

  9. A microwave window for K band electromagnetic systems

    DEFF Research Database (Denmark)

    Rybalko, Oleksandr

    2017-01-01

    and simulation results the prototype of the window is realized by implementing into transition section and tested experimentally. The microwave window provides low return loss |S11| below −30 dB, low insertion loss |S21| below −0.5 dB and can be used for electromagnetic systems where vacuum sealing is required...

  10. Steady-State Equilibrium Phase Inversion Recovery ON-resonant Water Suppression (IRON) Magnetic Resonance Angiography in Conjunction with Superparamagnetic Nanoparticles. A Robust Technique for Imaging within a Wide Range of Contrast Agent Dosages

    Science.gov (United States)

    Gitsioudis, Gitsios; Stuber, Matthias; Arend, Ingolf; Thomas, Moritz; Yu, Jing; Hilbel, Thomas; Giannitsis, Evangelos; Katus, Hugo A.; Korosoglou, Grigorios

    2012-01-01

    Objectives To investigate the ability of inversion recovery ON-resonant water suppression (IRON) in conjunction with P904 (superparamagnetic nanoparticles which consisting of a maghemite core coated with a low-molecular-weight amino-alcohol derivative of glucose) to perform steady-state equilibrium phase magnetic resonance angiography (MRA) over a wide dose range. Materials and Methods Experiments were approved by the institutional animal care committee. Rabbits (n=12) were imaged at baseline and serially after the administration of 10 incremental dosages of 0.57–5.7 mgFe/Kg P904. Conventional T1-weighted and IRON MRA were obtained on a clinical 1.5-T scanner to image the thoracic and abdominal aorta, and peripheral vessels. Contrast-to-noise ratios (CNR) and vessel sharpness were quantified. Results Using IRON MRA, CNR and vessel sharpness progressively increased with incremental dosages of the contrast agent P904, exhibiting constantly higher contrast values than T1-weighted MRA over a very wide range of contrast agent doses (CNR of 18.8±5.6 for IRON versus 11.1±2.8 for T1-weighted MRA at 1.71 mgFe/kg, p=0.02 and 19.8±5.9 for IRON versus −0.8±1.4 for T1-weighted MRA at 3.99 mgFe/kg, p=0.0002). Similar results were obtained for vessel sharpness in peripheral vessels, (Vessel sharpness of 46.76±6.48% for IRON versus 33.20±3.53% for T1-weighted MRA at 1.71 mgFe/Kg, p=0.002, and of 48.66±5.50% for IRON versus 19.00±7.41% for T1-weighted MRA at 3.99 mgFe/Kg, p=0.003). Conclusion Our study suggests that quantitative CNR and vessel sharpness after the injection of P904 are consistently higher for IRON MRA when compared to conventional T1-weighted MRA. These findings apply for a wide range of contrast agent dosages. PMID:23418107

  11. Sharpest Ever VLT Images at NAOS-CONICA "First Light"

    Science.gov (United States)

    2001-12-01

    Very Promising Start-Up of New Adaptive Optics Instrument at Paranal Summary A team of astronomers and engineers from French and German research institutes and ESO at the Paranal Observatory is celebrating the successful accomplishment of "First Light" for the NAOS-CONICA Adaptive Optics facility . With this event, another important milestone for the Very Large Telescope (VLT) project has been passed. Normally, the achievable image sharpness of a ground-based telescope is limited by the effect of atmospheric turbulence. However, with the Adaptive Optics (AO) technique, this drawback can be overcome and the telescope produces images that are at the theoretical limit, i.e., as sharp as if it were in space . Adaptive Optics works by means of a computer-controlled, flexible mirror that counteracts the image distortion induced by atmospheric turbulence in real time. The larger the main mirror of the telescope is, and the shorter the wavelength of the observed light, the sharper will be the images recorded. During a preceding four-week period of hard and concentrated work, the expert team assembled and installed this major astronomical instrument at the 8.2-m VLT YEPUN Unit Telescope (UT4). On November 25, 2001, following careful adjustments of this complex apparatus, a steady stream of photons from a southern star bounced off the computer-controlled deformable mirror inside NAOS and proceeded to form in CONICA the sharpest image produced so far by one of the VLT telescopes. With a core angular diameter of only 0.07 arcsec, this image is near the theoretical limit possible for a telescope of this size and at the infrared wavelength used for this demonstration (the K-band at 2.2 µm). Subsequent tests reached the spectacular performance of 0.04 arcsec in the J-band (wavelength 1.2 µm). "I am proud of this impressive achievement", says ESO Director General Catherine Cesarsky. "It shows the true potential of European science and technology and it provides a fine

  12. Health Care Wide Hazards

    Science.gov (United States)

    ... Scope | Glossary | References | Site Map | Credits Hospital eTool Administration Central Supply Clinical Services Dietary Emergency Engineering Healthcare Wide Hazards Heliport Housekeeping ICU Laboratory Laundry ...

  13. Eyes Wide Open

    OpenAIRE

    Zoi Manesi; Van Lange, Paul A. M.; Pollet, Thomas V.

    2016-01-01

    Research from evolutionary psychology suggests that the mere presence of eye images can promote prosocial behavior. However, the “eye images effect” is a source of considerable debate, and findings across studies have yielded somewhat inconsistent support. We suggest that one critical factor may be whether the eyes really need to be watching to effectively enhance prosocial behavior. In three experiments, we investigated the impact of eye images on prosocial behavior, assessed in a laboratory...

  14. Eyes Wide Open

    Directory of Open Access Journals (Sweden)

    Zoi Manesi

    2016-04-01

    Full Text Available Research from evolutionary psychology suggests that the mere presence of eye images can promote prosocial behavior. However, the “eye images effect” is a source of considerable debate, and findings across studies have yielded somewhat inconsistent support. We suggest that one critical factor may be whether the eyes really need to be watching to effectively enhance prosocial behavior. In three experiments, we investigated the impact of eye images on prosocial behavior, assessed in a laboratory setting. Participants were randomly assigned to view an image of watching eyes (eyes with direct gaze, an image of nonwatching eyes (i.e., eyes closed for Study 1 and averted eyes for Studies 2 and 3, or an image of flowers (control condition. Upon exposure to the stimuli, participants decided whether or not to help another participant by completing a dull cognitive task. Three independent studies produced somewhat mixed results. However, combined analysis of all three studies, with a total of 612 participants, showed that the watching component of the eyes is important for decision-making in this context. Images of watching eyes led to significantly greater inclination to offer help as compared to images of nonwatching eyes (i.e., eyes closed and averted eyes or images of flowers. These findings suggest that eyes gazing at an individual, rather than any proxy to social presence (e.g., just the eyes, serve as a reminder of reputation. Taken together, we conclude that it is “eyes that pay attention” that can lift the veil of anonymity and potentially facilitate prosocial behavior.

  15. AWARE Wide Field View

    Science.gov (United States)

    2016-04-29

    RGB colors to the standard sRGB to allow spectrally consistent colors on monitors for viewing . Finally, the images from each sensor are corrected based ...on the exposure time used and the calibrated sensitivity of each image sensor, again based on the flat field calibration, to allow viewing of imagery...prediction is scaled based on available bandwidth and the computational resources of the cluster. In addition to the interface described in the

  16. Combining image analysis, genome wide association studies and different field trials to reveal stable genetic regions related to panicle architecture and the number of spikelets per panicle in rice

    Directory of Open Access Journals (Sweden)

    Maria Camila Rebolledo

    2016-09-01

    Full Text Available Number of spikelets per panicle (NSP is a key trait to increase yield potential in rice (O. sativa. The architecture of the rice inflorescence which is mainly determined by the length and number of primary (PBL and PBN and secondary (SBL and SBN branches can influence NSP. Although several genes controlling panicle architecture and NSP in rice have been identified, there is little evidence of (i the genetic control of panicle architecture and NSP in different environments and (ii the presence of stable genetic associations with panicle architecture across environments. This study combines image phenotyping of 225 accessions belonging to a genetic diversity array of indica rice grown under irrigated field condition in two different environments and Genome Wide Association Studies (GWAS based on the genotyping of the diversity panel, providing 83,374 SNPs.Accessions sown under direct seeding in one environement had reduced Panicle Length (PL, NSP, PBN, PBL, SBN and SBL compared to those established under transplanting in the second environment. Across environments, NSP was significantly and positively correlated with PBN, SBN and PBL. However, the length of branches (PBL and SBL was not significantly correlated with variables related to number of branches (PBN and SBN , suggesting independent genetic control.Twenty- three GWAS sites were detected with P-values ≤ 1.0E-04 and 27 GWAS sites with p ≤ 5.9E-04. We found 17 GWAS sites related to NSP, 10 for PBN and 11 for SBN, 7 for PBL and 11 for SBL. This study revealed new regions related to NSP, but only three associations were related to both branching number (PBN and SBN and NSP. Two GWAS sites associated with SBL and SBN were stable across contrasting environments and were not related to genes previously reported.The new regions reported in this study can help improving NSP in rice for both direct seeded and transplanted conditions. The integrated approach of high-throughput phenotyping, multi

  17. Wide-Gap Chalcopyrites

    CERN Document Server

    Siebentritt, Susanne

    2006-01-01

    Chalcopyrites, in particular those with a wide band gap, are fascinating materials in terms of their technological potential in the next generation of thin-film solar cells and in terms of their basic material properties. They exhibit uniquely low defect formation energies, leading to unusual doping and phase behavior and to extremely benign grain boundaries. This book collects articles on a number of those basic material properties of wide-gap chalcopyrites, comparing them to their low-gap cousins. They explore the doping of the materials, the electronic structure and the transport through interfaces and grain boundaries, the formation of the electric field in a solar cell, the mechanisms and suppression of recombination, the role of inhomogeneities, and the technological role of wide-gap chalcopyrites.

  18. Ultra wide band antennas

    CERN Document Server

    Begaud, Xavier

    2013-01-01

    Ultra Wide Band Technology (UWB) has reached a level of maturity that allows us to offer wireless links with either high or low data rates. These wireless links are frequently associated with a location capability for which ultimate accuracy varies with the inverse of the frequency bandwidth. Using time or frequency domain waveforms, they are currently the subject of international standards facilitating their commercial implementation. Drawing up a complete state of the art, Ultra Wide Band Antennas is aimed at students, engineers and researchers and presents a summary of internationally recog

  19. Jihadism, Narrow and Wide

    DEFF Research Database (Denmark)

    Sedgwick, Mark

    2015-01-01

    The term “jihadism” is popular, but difficult. It has narrow senses, which are generally valuable, and wide senses, which may be misleading. This article looks at the derivation and use of “jihadism” and of related terms, at definitions provided by a number of leading scholars, and at media usage...

  20. World wide biomass resources

    NARCIS (Netherlands)

    Faaij, A.P.C.

    2012-01-01

    In a wide variety of scenarios, policy strategies, and studies that address the future world energy demand and the reduction of greenhouse gas emissions, biomass is considered to play a major role as renewable energy carrier. Over the past decades, the modern use of biomass has increased

  1. Wide angle pinhole camera

    Science.gov (United States)

    Franke, J. M.

    1978-01-01

    Hemispherical refracting element gives pinhole camera 180 degree field-of-view without compromising its simplicity and depth-of-field. Refracting element, located just behind pinhole, bends light coming in from sides so that it falls within image area of film. In contrast to earlier pinhole cameras that used water or other transparent fluids to widen field, this model is not subject to leakage and is easily loaded and unloaded with film. Moreover, by selecting glass with different indices of refraction, field at film plane can be widened or reduced.

  2. Wide Band Artificial Pulsar

    Science.gov (United States)

    Parsons, Zackary

    2017-01-01

    The Wide Band Artificial Pulsar (WBAP) is an instrument verification device designed and built by the National Radio Astronomy Observatory (NRAO) in Green Bank, West Virgina. The site currently operates the Green Bank Ultimate Pulsar Processing Instrument (GUPPI) and the Versatile Green Bank Astronomical Spectrometer (VEGAS) digital backends for their radio telescopes. The commissioning and continued support for these sophisticated backends has demonstrated a need for a device capable of producing an accurate artificial pulsar signal. The WBAP is designed to provide a very close approximation to an actual pulsar signal. This presentation is intended to provide an overview of the current hardware and software implementations and to also share the current results from testing using the WBAP.

  3. L’image du père et du jardin : Jane Eyre de Charlotte Brontë  et WideSargasso Sea de Jean Rhys Of Father Figures and Gardens: Charlotte Brontë’s Jane Eyre and Jean Rhys’s Wide Sargasso Sea

    Directory of Open Access Journals (Sweden)

    Anne-Marie Baranowski

    2009-10-01

    Full Text Available Though no father actually appears as a character either in Jane Eyre or in Wide Sargasso Sea, the father figure looms large in both novels, as a complex, protean and paradoxical entity, playing a crucial part in the fate of the protagonists. Jane Eyre and Antoinette Cosway are orphaned at an early age, Rochester’s father is depicted as remote and insensitive; the surrogate fathers —Antoinette’s stepfather, Jane’s uncles— mostly fail when they try to replace the missing one. Rochester himself is an ambiguous character who appears in both novels as a son, lover and husband on the one side, as a father figure on the other. In Wide Sargasso Sea he acquires through his marriage to the heiress Antoinette Cosway a legal authority which he eventually uses to destroy his wife; in Jane Eyre he first appears as the wealthier, more knowledgeable, stronger character before he discovers a female counterpart who does more than merely hold her ground.These different aspects of the father figure are closely linked to the motif of the garden which mirrors the inner development of the —mostly— female characters. It is not entirely similar to nature itself, though it is part of it; the latter means in both novels lethal dangers and elemental violence, whereas the garden is a sheltered place. In Wide Sargasso Sea, the debased garden of Coulibri simultaneously conveys a distorted, though by no means untrue reflection of the father figure and a sanctuary from the harshness of the outside world. It also means a place of peace and of simple joys for Jane Eyre, making up for the deprived life at the Lowood boarding school; but contrasting with Coulibri it does not preclude the contact with the outside world which she actually longs for. Hence the garden mirrors the crucial moments and experiences in the lives of both heroines, including love, married life and loss.

  4. Mile wide, inch deep?

    Science.gov (United States)

    Carlowicz, Michael

    Compared to their counterparts in other nations, American grade school students learn a lot less about a lot more. According to a new report entitled A Splintered Vision: An Investigation of U.S. Science and Mathematics Education, a student in the United States is expected to absorb information about a wide array of topics in a school year, yet he or she is seldom given the opportunity to explore any one topic in depth. The report was funded by the National Science Foundation (NSF) and is part of the Third International Mathematics and Science Study (TIMSS), a five-year project to compare teaching and student achievement in 45 countries.Before they reach high school, American students will have covered more topics than 75% of the students in other countries; yet in many cases, they will have been taught some of the same topics several years in a row. Researchers also criticized conventional U.S. education standards for being unfocused and aimed at the lowest common denominator. They noted that most American textbooks make minimal demands on students and they represent “a limited notion” of what should be discussed in “basic” texts.

  5. The KIDROP model of combining strategies for providing retinopathy of prematurity screening in underserved areas in India using wide-field imaging, tele-medicine, non-physician graders and smart phone reporting

    Directory of Open Access Journals (Sweden)

    Anand Vinekar

    2014-01-01

    Full Text Available Aim: To report the Karnataka Internet Assisted Diagnosis of Retinopathy of Prematurity (KIDROP program for retinopathy of prematurity (ROP screening in underserved rural areas using an indigenously developed tele-ROP model. Materials and Methods: KIDROP currently provides ROP screening and treatment services in three zones and 81 neonatal units in Karnataka, India. Technicians were trained to use a portable Retcam Shuttle (Clarity, USA and validated against ROP experts performing indirect ophthalmoscopy. An indigenously developed 20-point score (STAT score graded their ability (Level I to III to image and decide follow-up based on a three-way algorithm. Images were also uploaded on a secure tele-ROP platform and accessed and reported by remote experts on their smart phones (iPhone, Apple. Results: 6339 imaging sessions of 1601 infants were analyzed. A level III technician agreed with 94.3% of all expert decisions. The sensitivity, specificity, positive predictive value and negative predictive value for treatment grade disease were 95.7, 93.2, 81.5 and 98.6 respectively. The kappa for technicians to decide discharge of babies was 0.94 (P < 0.001. Only 0.4% of infants needing treatment were missed.The kappa agreement of experts reporting on the iPhone vs Retcam for treatment requiring and mild ROP were 0.96 and 0.94 (P < 0.001 respectively. Conclusions: This is the first and largest real-world program to employ accredited non-physicians to grade and report ROP. The KIDROP tele-ROP model demonstrates that ROP services can be delivered to the outreach despite lack of specialists and may be useful in other middle-income countries with similar demographics.

  6. Construction of imaging system for wide-field-range ESR spectra using localized microwave field and its case study of crystal orientation in suspension of copper sulfate pentahydrate (CuSO4 . 5H2O).

    Science.gov (United States)

    Tani, Atsushi; Ueno, Takehiro; Yamanaka, Chihiro; Katsura, Makoto; Ikeya, Motoji

    2005-02-01

    A scanning electron spin resonance (ESR) microscope using a localized microwave field was redesigned to measure ESR spectra from 0 to 400 mT using electromagnets. Divalent copper ion (Cu2+) in copper sulfate pentahydrate (CuSO4 . 5H2O) was imaged, after the powdered samples were cemented in silicone rubber under a magnetic field. The ratio of the two signal intensities at g=2.27 and 2.08 clearly indicates the orientation of the particles. This method can be used for mapping the local magnetic field and its direction.

  7. Construction of imaging system for wide-field-range ESR spectra using localized microwave field and its case study of crystal orientation in suspension of copper sulfate pentahydrate (CuSO{sub 4}.5H{sub 2}O)

    Energy Technology Data Exchange (ETDEWEB)

    Tani, Atsushi [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama Toyonaka, Osaka 560-0043 (Japan)]. E-mail: atani@ess.sci.osaka-u.ac.jp; Ueno, Takehiro [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama Toyonaka, Osaka 560-0043 (Japan); Yamanaka, Chihiro [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama Toyonaka, Osaka 560-0043 (Japan); Katsura, Makoto [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama Toyonaka, Osaka 560-0043 (Japan); Ikeya, Motoji [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama Toyonaka, Osaka 560-0043 (Japan)

    2005-02-01

    A scanning electron spin resonance (ESR) microscope using a localized microwave field was redesigned to measure ESR spectra from 0 to 400mT using electromagnets. Divalent copper ion (Cu{sup 2+}) in copper sulfate pentahydrate (CuSO{sub 4}.5H{sub 2}O) was imaged, after the powdered samples were cemented in silicone rubber under a magnetic field. The ratio of the two signal intensities at g=2.27 and 2.08 clearly indicates the orientation of the particles. This method can be used for mapping the local magnetic field and its direction.

  8. IMAGES, IMAGES, IMAGES

    Energy Technology Data Exchange (ETDEWEB)

    Marcus, A.

    1980-07-01

    The role of images of information (charts, diagrams, maps, and symbols) for effective presentation of facts and concepts is expanding dramatically because of advances in computer graphics technology, increasingly hetero-lingual, hetero-cultural world target populations of information providers, the urgent need to convey more efficiently vast amounts of information, the broadening population of (non-expert) computer users, the decrease of available time for reading texts and for decision making, and the general level of literacy. A coalition of visual performance experts, human engineering specialists, computer scientists, and graphic designers/artists is required to resolve human factors aspects of images of information. The need for, nature of, and benefits of interdisciplinary effort are discussed. The results of an interdisciplinary collaboration are demonstrated in a product for visualizing complex information about global energy interdependence. An invited panel will respond to the presentation.

  9. Wide-Bandgap Semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Chinthavali, M.S.

    2005-11-22

    With the increase in demand for more efficient, higher-power, and higher-temperature operation of power converters, design engineers face the challenge of increasing the efficiency and power density of converters [1, 2]. Development in power semiconductors is vital for achieving the design goals set by the industry. Silicon (Si) power devices have reached their theoretical limits in terms of higher-temperature and higher-power operation by virtue of the physical properties of the material. To overcome these limitations, research has focused on wide-bandgap materials such as silicon carbide (SiC), gallium nitride (GaN), and diamond because of their superior material advantages such as large bandgap, high thermal conductivity, and high critical breakdown field strength. Diamond is the ultimate material for power devices because of its greater than tenfold improvement in electrical properties compared with silicon; however, it is more suited for higher-voltage (grid level) higher-power applications based on the intrinsic properties of the material [3]. GaN and SiC power devices have similar performance improvements over Si power devices. GaN performs only slightly better than SiC. Both SiC and GaN have processing issues that need to be resolved before they can seriously challenge Si power devices; however, SiC is at a more technically advanced stage than GaN. SiC is considered to be the best transition material for future power devices before high-power diamond device technology matures. Since SiC power devices have lower losses than Si devices, SiC-based power converters are more efficient. With the high-temperature operation capability of SiC, thermal management requirements are reduced; therefore, a smaller heat sink would be sufficient. In addition, since SiC power devices can be switched at higher frequencies, smaller passive components are required in power converters. Smaller heat sinks and passive components result in higher-power-density power converters

  10. Michelson wide-field stellar interferometry : Principles and experimental verification

    NARCIS (Netherlands)

    Montilla, I.; Pereira, S.F.; Braat, J.J.M.

    2005-01-01

    A new interferometric technique for Michelson wide-field interferometry is presented that consists of a Michelson pupil-plane combination scheme in which a wide field of view can be achieved in one shot. This technique uses a stair-shaped mirror in the intermediate image plane of each telescope in

  11. Imaging genomics.

    Science.gov (United States)

    Thompson, Paul M; Martin, Nicholas G; Wright, Margaret J

    2010-08-01

    Imaging genomics is an emerging field that is rapidly identifying genes that influence the brain, cognition, and risk for disease. Worldwide, thousands of individuals are being scanned with high-throughput genotyping (genome-wide scans), and new imaging techniques [high angular resolution diffusion imaging and resting state functional magnetic resonance imaging (MRI)] that provide fine-grained measures of the brain's structural and functional connectivity. Along with clinical diagnosis and cognitive testing, brain imaging offers highly reproducible measures that can be subjected to genetic analysis. Recent studies of twin, pedigree, and population-based datasets have discovered several candidate genes that consistently show small to moderate effects on brain measures. Many studies measure single phenotypes from the images, such as hippocampal volume, but voxel-wise genomic methods can plot the profile of genetic association at each 3D point in the brain. This exploits the full arsenal of imaging statistics to discover and replicate gene effects. Imaging genomics efforts worldwide are now working together to discover and replicate many promising leads. By studying brain phenotypes closer to causative gene action, larger gene effects are detectable with realistic sample sizes obtainable from meta-analysis of smaller studies. Imaging genomics has broad applications to dementia, mental illness, and public health.

  12. Calibration and testing of wide-field UV instruments

    Science.gov (United States)

    Frey, H. U.; Mende, S. B.; Loicq, J.; Habraken, S.

    2017-06-01

    As with all optical systems the calibration of wide-field ultraviolet (UV) systems includes three main areas: sensitivity, imaging quality, and imaging capability. The one thing that makes UV calibrations difficult is the need for working in vacuum substantially extending the required time and effort compared to visible systems. In theory a ray tracing and characterization of each individual component of the optical system (mirrors, windows, and grating) should provide the transmission efficiency of the combined system. However, potentially unknown effects (contamination, misalignment, and measurement errors) can make the final error too large and unacceptable for most applications. Therefore, it is desirable to test and measure the optical properties of the whole system in vacuum and compare the overall response to the response of a calibrated photon detector. A proper comparison then allows the quantification of individual sources of uncertainty and ensures that the whole instrument performance is within acceptable tolerances or pinpoints which parts fail to meet requirements. Based on the experience with the IMAGE Spectrographic Imager, the Wide-band Imaging Camera, and the ICON Far Ultraviolet instruments, we discuss the steps and procedures for the proper radiometric sensitivity and passband calibration, spot size, imaging distortions, flatfield, and field of view determination.Plain Language SummaryAs with all optical systems the calibration of wide-field ultraviolet (UV) systems includes three main areas: sensitivity, imaging quality, and imaging capability. The one thing that makes UV calibrations difficult is the need for working in vacuum substantially extending the required time and effort compared to visible systems. Based on the experience with the IMAGE Spectrographic Imager, the Wide-band Imaging Camera (WIC), and the ICON Far Ultraviolet instruments, we discuss the steps and procedures for the proper radiometric sensitivity and pass-band calibration

  13. Wide-angle energy-momentum spectroscopy

    CERN Document Server

    Dodson, Christopher M; Li, Dongfang; Zia, Rashid

    2014-01-01

    Light emission is defined by its distribution in energy, momentum, and polarization. Here, we demonstrate a method that resolves these distributions by means of wide-angle energy-momentum spectroscopy. Specifically, we image the back focal plane of a microscope objective through a Wollaston prism to obtain polarized Fourier-space momentum distributions, and disperse these two-dimensional radiation patterns through an imaging spectrograph without an entrance slit. The resulting measurements represent a convolution of individual radiation patterns at adjacent wavelengths, which can be readily deconvolved using any well-defined basis for light emission. As an illustrative example, we use this technique with the multipole basis to quantify the intrinsic emission rates for electric and magnetic dipole transitions in europium-doped yttrium oxide (Eu$^{3+}$:Y$_{2}$O$_{3}$) and chromium-doped magnesium oxide (Cr$^{3+}$:MgO). Once extracted, these rates allow us to reconstruct the full, polarized, two-dimensional radi...

  14. High resolution imaging of the Venus night side using a Rockwell 128x128 HgCdTe array

    Science.gov (United States)

    Hodapp, K.-W.; Sinton, W.; Ragent, B.; Allen, D.

    1989-01-01

    The University of Hawaii operates an infrared camera with a 128x128 HgCdTe detector array on loan from JPL's High Resolution Imaging Spectrometer (HIRIS) project. The characteristics of this camera system are discussed. The infrared camera was used to obtain images of the night side of Venus prior to and after inferior conjunction in 1988. The images confirm Allen and Crawford's (1984) discovery of bright features on the dark hemisphere of Venus visible in the H and K bands. Our images of these features are the best obtained to date. Researchers derive a pseudo rotation period of 6.5 days for these features and 1.74 microns brightness temperatures between 425 K and 480 K. The features are produced by nonuniform absorption in the middle cloud layer (47 to 57 Km altitude) of thermal radiation from the lower Venus atmosphere (20 to 30 Km altitude). A more detailed analysis of the data is in progress.

  15. The HST Medium Deep Survey: Steward BVRIJK and FASTTRAK JHK imaging and photometry of faint field galaxies from parallel WF/PC images

    Science.gov (United States)

    Mutz, S. B.; Windhorst, R. A.; Ostrander, E. J.; Wittman, D.; Close, L.; McCarthy, D.; Griffiths, R. E.; Neuschaefer, L. W.

    1994-12-01

    We present ground-based optical (BVRI) and infrared (JHK) photometry for 15 galaxy fields previously observed with HST as part of the Medium-Deep Survey. We use the HST images to determine bulge and disk scale-lengths at 0.1 - 0.2'' FWHM for 70 galaxies in the V and I-bands. We constrain their star-formation history from their ground-based + HST BVRIJHK colors. For galaxies too faint for MMT spectroscopy, we use their BVRIJHK photometry to constrain their redshift-range through Bruzual's (1990) spectral evolution models. Comparing these photometric redshift estimates to spectroscopic redshifts for a brighter subsample, we find acceptable agreement.We conclude this is an efficient way of finding large numbers of field galaxies with z >= 0.8. Using photometric redshift estimates, we extend the Theta -z relation for HST bulges and disks (using world models with q_o = 0.0 - 1.0, see Mutz et al. 1994, ApJL, 434, L055) to z >= 0.8 (V >= 24 mag), beyond most ground-based spectroscopy. We also observed three brighter (17.5 <= I <= 19.0) galaxies with spectroscopic redshifts of z = 0.12 - 0.28 in the K-band with the Steward 90 inch FASTTRAC tip/tilt corrector system. Under seeing conditions of 1.75'' FWHM for a single image of 1.0 second, we derived K-band imaging with FWHM = 1.076'' for a stack of 158 60-second images. We present their V, I, and K-band light profiles, and V-I and I-K color gradients. The V-I and V-K color profiles show that the object at z = 0.12 is likely an early-type galaxy with an exponentially declining star formation parameter mu = 0.4. The object at z = 0.23 is an early-type galaxy with mu = 0.7. The object at z = 0.28 is a late-type disk galaxy seen nearly edge-on. We discuss using FASTTRAC under better seeing conditions and at telescopes with a more optimal ratio of Fried-parameter to mirror-diameter. This work was supported by NASA/HST grants GO-2684-0*-93A from STScI, which is operated by AURA, Inc., under NASA contract NAS5-26555.

  16. Reconfigurable metasurface aperture for security screening and microwave imaging

    Science.gov (United States)

    Sleasman, Timothy; Imani, Mohammadreza F.; Boyarsky, Michael; Pulido-Mancera, Laura; Reynolds, Matthew S.; Smith, David R.

    2017-05-01

    Microwave imaging systems have seen growing interest in recent decades for applications ranging from security screening to space/earth observation. However, hardware architectures commonly used for this purpose have not seen drastic changes. With the advent of metamaterials a wealth of opportunities have emerged for honing metasurface apertures for microwave imaging systems. Recent thrusts have introduced dynamic reconfigurability directly into the aperture layer, providing powerful capabilities from a physical layer with considerable simplicity. The waveforms generated from such dynamic metasurfaces make them suitable for application in synthetic aperture radar (SAR) and, more generally, computational imaging. In this paper, we investigate a dynamic metasurface aperture capable of performing microwave imaging in the K-band (17.5-26.5 GHz). The proposed aperture is planar and promises an inexpensive fabrication process via printed circuit board techniques. These traits are further augmented by the tunability of dynamic metasurfaces, which provides the dexterity necessary to generate field patterns ranging from a sequence of steered beams to a series of uncorrelated radiation patterns. Imaging is experimentally demonstrated with a voltage-tunable metasurface aperture. We also demonstrate the aperture's utility in real-time measurements and perform volumetric SAR imaging. The capabilities of a prototype are detailed and the future prospects of general dynamic metasurface apertures are discussed.

  17. VizieR Online Data Catalog: Kepler follow-up observation program. I. Imaging (Furlan+, 2017)

    Science.gov (United States)

    Furlan, E.; Ciardi, D. R.; Everett, M. E.; Saylors, M.; Teske, J. K.; Horch, E. P.; Howell, S. B.; van Belle, G. T.; Hirsch, L. A.; Gautier, T. N.; Adams, E. R.; Barrado, D.; Cartier, K. M. S.; Dressing, C. D.; Dupree, A. K.; Gilliland, R. L.; Lillo-Box, J.; Lucas, P. W.; Wang, J.

    2017-07-01

    We present results from six years of follow-up imaging observations of KOI host stars, including work done by teams from the Kepler Community Follow-up Observation Program (CFOP; https://exofop.ipac.caltech.edu/cfop.php) and by other groups. Several observing facilities were used to obtain high-resolution images of KOI host stars. Table1 lists the various telescopes, instruments used, filter bandpasses, typical Point Spread Function (PSF) widths, number of targets observed, and main references for the published results. The four main observing techniques employed are adaptive optics (Keck, Palomar, Lick, MMT), speckle interferometry (Gemini North, WIYN, DCT), lucky imaging (Calar Alto), and imaging from space with HST. A total of 3557 KOI host stars were observed at 11 facilities with 9 different instruments, using filters from the optical to the near-infrared. In addition, 10 of these stars were also observed at the 8m Gemini North telescope by Ziegler et al. 2016 (AJ accepted, arXiv:1605.03584) using laser guide star adaptive optics. The largest number of KOI host stars (3320) were observed using Robo-AO at the Palomar 1.5m telescope (Baranec et al. 2014ApJ...790L...8B; Baranec et al. 2016, Cat. J/AJ/152/18; Law et al. 2014, Cat. J/ApJ/791/35; Ziegler et al. 2016, AJ accepted, arXiv:1605.03584). A total of 8332 observations were carried out from 2009 September to 2015 October covering 3557 stars. We carried out observations at the Keck, Palomar, and Lick Observatory using the facility adaptive optics systems and near-infrared cameras from 2009 to 2015. At Keck, we observed with the 10m Keck II telescope and Near-Infrared Camera, second generation (NIRC2). The pixel scale of NIRC2 was 0.01''/pixel, resulting in a field of view of about 10''*10''. We observed our targets in a narrow K-band filter, Brγ, which has a central wavelength of 2.1686μm. In most cases, when a companion was detected, we also observed the target in a narrow-band J filter, Jcont, which is

  18. System Wide Information Management (SWIM)

    Science.gov (United States)

    Hritz, Mike; McGowan, Shirley; Ramos, Cal

    2004-01-01

    This viewgraph presentation lists questions regarding the implementation of System Wide Information Management (SWIM). Some of the questions concern policy issues and strategies, technology issues and strategies, or transition issues and strategies.

  19. Wide spectrum microwave pulse measurement

    Energy Technology Data Exchange (ETDEWEB)

    King, R.J.

    1986-01-01

    Various techniques are postulated as diagnostics for wide band microwave pulses. The diagnostics include determinations of both the instantaneous amplitude and the frequency content of one-shot pulses. 6 refs., 11 figs. (WRF)

  20. Image Segmentation Algorithms Overview

    OpenAIRE

    Yuheng, Song; Hao, Yan

    2017-01-01

    The technology of image segmentation is widely used in medical image processing, face recognition pedestrian detection, etc. The current image segmentation techniques include region-based segmentation, edge detection segmentation, segmentation based on clustering, segmentation based on weakly-supervised learning in CNN, etc. This paper analyzes and summarizes these algorithms of image segmentation, and compares the advantages and disadvantages of different algorithms. Finally, we make a predi...

  1. High Resolution Wide Field of View Stereographic Imaging System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The overarching challenge of tele-presence is to provide an environment to the human operator that is sufficiently familiar that the interface itself does not become...

  2. Wide-Field Plate Database

    Science.gov (United States)

    Tsvetkov, M. K.; Stavrev, K. Y.; Tsvetkova, K. P.; Semkov, E. H.; Mutatov, A. S.

    The Wide-Field Plate Database (WFPDB) and the possibilities for its application as a research tool in observational astronomy are presented. Currently the WFPDB comprises the descriptive data for 400 000 archival wide field photographic plates obtained with 77 instruments, from a total of 1 850 000 photographs stored in 269 astronomical archives all over the world since the end of last century. The WFPDB is already accessible for the astronomical community, now only in batch mode through user requests sent by e-mail. We are working on on-line interactive access to the data via INTERNET from Sofia and parallel from the Centre de Donnees Astronomiques de Strasbourg. (Initial information can be found on World Wide Web homepage URL http://www.wfpa.acad.bg.) The WFPDB may be useful in studies of a variety of astronomical objects and phenomena, andespecially for long-term investigations of variable objects and for multi-wavelength research. We have analysed the data in the WFPDB in order to derive the overall characteristics of the totality of wide-field observations, such as the sky coverage, the distributions by observation time and date, by spectral band, and by object type. We have also examined the totality of wide-field observations from point of view of their quality, availability and digitisation. The usefulness of the WFPDB is demonstrated by the results of identification and investigation of the photometrical behaviour of optical analogues of gamma-ray bursts.

  3. Medication-wide association studies

    NARCIS (Netherlands)

    P.B. Ryan (Patrick); D. Madigan (David); P.E. Stang (Paul); M.J. Schuemie (Martijn); G. Hripcsak (G.)

    2013-01-01

    textabstractUndiscovered side effects of drugs can have a profound effect on the health of the nation, and electronic health-care databases offer opportunities to speed up the discovery of these side effects. We applied a "medication-wide association study" approach that combined multivariate

  4. The Ooty Wide Field Array

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy; Volume 38; Issue 1. The Ooty Wide Field Array. C. R. Subrahmanya P. K. Manoharan Jayaram N. Chengalur. Review Article Volume 38 Issue 1 March 2017 Article ID ... Keywords. Cosmology: large scale structure of Universe; intergalactic medium; diffuse radiation.

  5. Wide Bandgap Extrinsic Photoconductive Switches

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, James S. [State Univ. of New York (SUNY), Plattsburgh, NY (United States); Univ. of California, Davis, CA (United States)

    2012-01-20

    Photoconductive semiconductor switches (PCSS) have been investigated since the late 1970s. Some devices have been developed that withstand tens of kilovolts and others that switch hundreds of amperes. However, no single device has been developed that can reliably withstand both high voltage and switch high current. Yet, photoconductive switches still hold the promise of reliable high voltage and high current operation with subnanosecond risetimes. Particularly since good quality, bulk, single crystal, wide bandgap semiconductor materials have recently become available. In this chapter we will review the basic operation of PCSS devices, status of PCSS devices and properties of the wide bandgap semiconductors 4H-SiC, 6H-SiC and 2H-GaN.

  6. Wide and High Additive Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Post, Brian K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Roschli, Alex C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-03-01

    The goal of this project is to develop and demonstrate the enabling technologies for Wide and High Additive Manufacturing (WHAM). WHAM will open up new areas of U.S. manufacturing for very large tooling in support of the transportation and energy industries, significantly reducing cost and lead time. As with Big Area Additive Manufacturing (BAAM), the initial focus is on the deposition of composite materials.

  7. Wide Bandgap Extrinsic Photoconductive Switches

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, James S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2013-07-03

    Semi-insulating Gallium Nitride, 4H and 6H Silicon Carbide are attractive materials for compact, high voltage, extrinsic, photoconductive switches due to their wide bandgap, high dark resistance, high critical electric field strength and high electron saturation velocity. These wide bandgap semiconductors are made semi-insulating by the addition of vanadium (4H and 6HSiC) and iron (2H-GaN) impurities that form deep acceptors. These deep acceptors trap electrons donated from shallow donor impurities. The electrons can be optically excited from these deep acceptor levels into the conduction band to transition the wide bandgap semiconductor materials from a semi-insulating to a conducting state. Extrinsic photoconductive switches with opposing electrodes have been constructed using vanadium compensated 6H-SiC and iron compensated 2H-GaN. These extrinsic photoconductive switches were tested at high voltage and high power to determine if they could be successfully used as the closing switch in compact medical accelerators.

  8. Large scale track analysis for wide area motion imagery surveillance

    NARCIS (Netherlands)

    Leeuwen, C.J. van; Huis, J.R. van; Baan, J.

    2016-01-01

    Wide Area Motion Imagery (WAMI) enables image based surveillance of areas that can cover multiple square kilometers. Interpreting and analyzing information from such sources, becomes increasingly time consuming as more data is added from newly developed methods for information extraction. Captured

  9. Comprehensive simulation platform for a metamaterial imaging system.

    Science.gov (United States)

    Lipworth, Guy; Rose, Alec; Yurduseven, Okan; Gowda, Vinay R; Imani, Mohammadreza F; Odabasi, Hayrettin; Trofatter, Parker; Gollub, Jonah; Smith, David R

    2015-11-01

    Recently, a frequency-diverse, metamaterial-based aperture has been introduced in the context of microwave and millimeter wave imaging. The generic form of the aperture is that of a parallel plate waveguide, in which complementary metamaterial elements patterned into the upper plate couple energy from the waveguide mode to the scene. To reliably predict the imaging performance of such an aperture prior to fabrication and experiments, it is necessary to have an accurate forward model that predicts radiation from the aperture, a model for scattering from an arbitrary target in the scene, and a set of image reconstruction approaches that allow scene estimation from an arbitrary set of measurements. Here, we introduce a forward model in which the metamaterial elements are approximated as polarizable magnetic dipoles, excited by the fields propagating within the waveguide. The dipoles used in the model can have arbitrarily assigned polarizability characteristics. Alternatively, fields measured from actual metamaterial samples can be decomposed into a set of effective dipole radiators, allowing the performance of actual samples to be quantitatively modeled and compared with simulated apertures. To confirm the validity of our model, we simulate measurements and scene reconstructions with a virtual multiaperture imaging system operating in the K-band spectrum (18-26.5 GHz) and compare its performance with an experimental system.

  10. WFIRST: Simulating the Wide-Field Sky

    Science.gov (United States)

    Peeples, Molly; WFIRST Wide Field Imager Simulations Working Group

    2018-01-01

    As astronomy’s first high-resolution wide-field multi-mode instrument, simulated data will play a vital role in the planning for and analysis of data from WFIRST’s WFI (Wide Field Imager) instrument. Part of the key to WFIRST’s scientific success lies in our ability to push the systematics limit, but in order to do so, the WFI pipeline will need to be able to measure and take out said systematics. The efficacy of this pipeline can only be verified with large suites of synthetic data; these data must include both the range of astrophysical sky scenes (from crowded starfields to high-latitude grism data observations) and the systematics from the detector and telescope optics the WFI pipeline aims to mitigate. We summarize here(1) the status of current and planned astrophysical simulations in support of the WFI,(2) the status of current WFI instrument simulators and requirements on future generations thereof, and(3) plans, methods, and requirements on interfacing astrophysical simulations and WFI instrument simulators.

  11. EGSIEM combination service: combination of GRACE monthly K-band solutions on normal equation level

    Science.gov (United States)

    Meyer, Ulrich; Jean, Yoomin; Arnold, Daniel; Jäggi, Adrian

    2017-04-01

    The European Gravity Service for Improved Emergency Management (EGSIEM) project offers a scientific combination service, combining for the first time monthly GRACE gravity fields of different analysis centers (ACs) on normal equation (NEQ) level and thus taking all correlations between the gravity field coefficients and pre-eliminated orbit and instrument parameters correctly into account. Optimal weights for the individual NEQs are commonly derived by variance component estimation (VCE), as is the case for the products of the International VLBI Service (IVS) or the DTRF2008 reference frame realisation that are also derived by combination on NEQ-level. But variance factors are based on post-fit residuals and strongly depend on observation sampling and noise modeling, which both are very diverse in case of the individual EGSIEM ACs. These variance factors do not necessarily represent the true error levels of the estimated gravity field parameters that are still governed by analysis noise. We present a combination approach where weights are derived on solution level, thereby taking the analysis noise into account.

  12. Evolution of the K-band Galaxy Cluster Luminosity Function and Scaling Relations

    OpenAIRE

    Lin, Yen-Ting; Mohr, Joseph J.; Gonzalez, Anthony H.; Stanford, S Adam

    2006-01-01

    We study the evolution of two fundamental properties of galaxy clusters: the luminosity function (LF) and the scaling relations between the total galaxy number N (or luminosity) and cluster mass M. Using a sample of 27 clusters (0

  13. The LOFT wide field monitor

    DEFF Research Database (Denmark)

    Brandt, Søren; Hernanz, M.; Alvarez, L.

    2012-01-01

    be able to address fundamental questions about strong gravity in the vicinity of black holes and the equation of state of nuclear matter in neutron stars. The prime goal of the WFM will be to detect transient sources to be observed by the LAD. However, with its wide field of view and good energy...... to the community of ~100 gamma ray burst positions per year with a ~1 arcmin location accuracy within 30 s of the burst. This paper provides an overview of the design, configuration, and capabilities of the LOFT WFM instrument....

  14. Review of advanced imaging techniques

    OpenAIRE

    Yu Chen; Chia-Pin Liang; Yang Liu; Fischer, Andrew H.; Parwani, Anil V.; Liron Pantanowitz

    2012-01-01

    Pathology informatics encompasses digital imaging and related applications. Several specialized microscopy techniques have emerged which permit the acquisition of digital images ("optical biopsies") at high resolution. Coupled with fiber-optic and micro-optic components, some of these imaging techniques (e.g., optical coherence tomography) are now integrated with a wide range of imaging devices such as endoscopes, laparoscopes, catheters, and needles that enable imaging inside the body. These...

  15. Geriatric imaging

    Energy Technology Data Exchange (ETDEWEB)

    Guglielmi, Giuseppe [Scientific Institute Casa Sollievo della Sofferenza Hospital, San Giovanni Rotondo (Italy). Dept. of Radiology; Peh, Wilfred C.G. [Khoo Teck Puat Hospital, Singapore (Singapore). Dept. of Diagnostic Radiology; Guermazi, Ali (eds.) [Boston Univ. School of Medicine, Boston, MA (United States). Dept. of Radiology

    2013-08-01

    Considers all aspect of geriatric imaging. Explains clearly how to distinguish the healthy elderly from those in need of treatment. Superbly illustrated. Written by recognized experts in field. In the elderly, the coexistence of various diseases, the presence of involutional and degenerative changes, and the occurrence of both physical and cognitive problems represent ''the norm.'' It is therefore important to know how to distinguish the healthy elderly from those in need of treatment as a sound basis for avoiding overdiagnosis and overtreatment. This aspect is a central theme in Geriatric Imaging, which covers a wide range of applications of different imaging techniques and clearly explains both the potential and the limitations of diagnostic imaging in geriatric patients. Individual sections are devoted to each major region or system of the body, and a concluding section focuses specifically on interventional procedures. The book, written by recognized experts in the field, is superbly illustrated and will be an ideal resource for geriatricians, radiologists, and trainees.

  16. Biomedical photoacoustic imaging.

    Science.gov (United States)

    Beard, Paul

    2011-08-06

    Photoacoustic (PA) imaging, also called optoacoustic imaging, is a new biomedical imaging modality based on the use of laser-generated ultrasound that has emerged over the last decade. It is a hybrid modality, combining the high-contrast and spectroscopic-based specificity of optical imaging with the high spatial resolution of ultrasound imaging. In essence, a PA image can be regarded as an ultrasound image in which the contrast depends not on the mechanical and elastic properties of the tissue, but its optical properties, specifically optical absorption. As a consequence, it offers greater specificity than conventional ultrasound imaging with the ability to detect haemoglobin, lipids, water and other light-absorbing chomophores, but with greater penetration depth than purely optical imaging modalities that rely on ballistic photons. As well as visualizing anatomical structures such as the microvasculature, it can also provide functional information in the form of blood oxygenation, blood flow and temperature. All of this can be achieved over a wide range of length scales from micrometres to centimetres with scalable spatial resolution. These attributes lend PA imaging to a wide variety of applications in clinical medicine, preclinical research and basic biology for studying cancer, cardiovascular disease, abnormalities of the microcirculation and other conditions. With the emergence of a variety of truly compelling in vivo images obtained by a number of groups around the world in the last 2-3 years, the technique has come of age and the promise of PA imaging is now beginning to be realized. Recent highlights include the demonstration of whole-body small-animal imaging, the first demonstrations of molecular imaging, the introduction of new microscopy modes and the first steps towards clinical breast imaging being taken as well as a myriad of in vivo preclinical imaging studies. In this article, the underlying physical principles of the technique, its practical

  17. New Subarray Readout Patterns for the ACS Wide Field Channel

    Science.gov (United States)

    Golimowski, D.; Anderson, J.; Arslanian, S.; Chiaberge, M.; Grogin, N.; Lim, Pey Lian; Lupie, O.; McMaster, M.; Reinhart, M.; Schiffer, F.; Serrano, B.; Van Marshall, M.; Welty, A.

    2017-04-01

    At the start of Cycle 24, the original CCD-readout timing patterns used to generate ACS Wide Field Channel (WFC) subarray images were replaced with new patterns adapted from the four-quadrant readout pattern used to generate full-frame WFC images. The primary motivation for this replacement was a substantial reduction of observatory and staff resources needed to support WFC subarray bias calibration, which became a new and challenging obligation after the installation of the ACS CCD Electronics Box Replacement during Servicing Mission 4. The new readout patterns also improve the overall efficiency of observing with WFC subarrays and enable the processing of subarray images through stages of the ACS data calibration pipeline (calacs) that were previously restricted to full-frame WFC images. The new readout patterns replace the original 512×512, 1024×1024, and 2048×2046-pixel subarrays with subarrays having 2048 columns and 512, 1024, and 2048 rows, respectively. Whereas the original square subarrays were limited to certain WFC quadrants, the new rectangular subarrays are available in all four quadrants. The underlying bias structure of the new subarrays now conforms with those of the corresponding regions of the full-frame image, which allows raw frames in all image formats to be calibrated using one contemporaneous full-frame "superbias" reference image. The original subarrays remain available for scientific use, but calibration of these image formats is no longer supported by STScI.

  18. Neutron imaging and applications a reference for the imaging community

    CERN Document Server

    McGreevy, Robert L; Bilheux, Hassina Z

    2009-01-01

    Offers an introduction to the basics of neutron beam production in addition to the wide scope of techniques that enhance imaging application capabilities. This title features a section that describes imaging single grains in polycrystalline materials, neutron imaging of geological materials and other materials science and engineering areas.

  19. GEMINI PLANET IMAGER SPECTROSCOPY OF THE HR 8799 PLANETS c AND d

    Energy Technology Data Exchange (ETDEWEB)

    Ingraham, Patrick; Macintosh, Bruce [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305 (United States); Marley, Mark S. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Saumon, Didier [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Marois, Christian; Dunn, Jennifer; Erikson, Darren [NRC Herzberg Astronomy and Astrophysics, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Barman, Travis [Lunar and Planetary Laboratory, University of Arizona, Tucson, Arizona 85721-0092 (United States); Bauman, Brian [Lawrence Livermore National Lab, 7000 East Avenue, Livermore, CA 94551 (United States); Burrows, Adam [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Chilcote, Jeffrey K.; Fitzgerald, Michael P. [Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095 (United States); De Rosa, Robert J. [School of Earth and Space Exploration, Arizona State University, PO Box 871404, Tempe, AZ 85287 (United States); Dillon, Daren; Gavel, Donald [Department of Astronomy, UC Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States); Doyon, René [Department de Physique, Université de Montréal, Montréal QC H3C 3J7 (Canada); Goodsell, Stephen J.; Hartung, Markus; Hibon, Pascale [Gemini Observatory, Casilla 603, La Serena (Chile); Graham, James R. [Department of Astronomy, UC Berkeley, Berkeley CA, 94720 (United States); and others

    2014-10-10

    During the first-light run of the Gemini Planet Imager we obtained K-band spectra of exoplanets HR 8799 c and d. Analysis of the spectra indicates that planet d may be warmer than planet c. Comparisons to recent patchy cloud models and previously obtained observations over multiple wavelengths confirm that thick clouds combined with horizontal variation in the cloud cover generally reproduce the planets' spectral energy distributions. When combined with the 3 to 4 μm photometric data points, the observations provide strong constraints on the atmospheric methane content for both planets. The data also provide further evidence that future modeling efforts must include cloud opacity, possibly including cloud holes, disequilibrium chemistry, and super-solar metallicity.

  20. Iris recognition via plenoptic imaging

    Energy Technology Data Exchange (ETDEWEB)

    Santos-Villalobos, Hector J.; Boehnen, Chris Bensing; Bolme, David S.

    2017-11-07

    Iris recognition can be accomplished for a wide variety of eye images by using plenoptic imaging. Using plenoptic technology, it is possible to correct focus after image acquisition. One example technology reconstructs images having different focus depths and stitches them together, resulting in a fully focused image, even in an off-angle gaze scenario. Another example technology determines three-dimensional data for an eye and incorporates it into an eye model used for iris recognition processing. Another example technology detects contact lenses. Application of the technologies can result in improved iris recognition under a wide variety of scenarios.

  1. Imaging in nuclear medicine

    CERN Document Server

    Hoeschen, Christoph

    2013-01-01

    This volume addresses a wide range of issues in the field of nuclear medicine imaging, with an emphasis on the latest research findings. Initial chapters set the scene by considering the role of imaging in nuclear medicine from the medical perspective and discussing the implications of novel agents and applications for imaging. The physics at the basis of the most modern imaging systems is described, and the reader is introduced to the latest advances in image reconstruction and noise correction. Various novel concepts are then discussed, including those developed within the framework of the EURATOM FP7 MADEIRA research project on the optimization of imaging procedures in order to permit a reduction in the radiation dose to healthy tissues. Advances in quality control and quality assurance are covered, and the book concludes by listing rules of thumb for imaging that will be of use to both beginners and experienced researchers.

  2. Learning chest imaging

    Energy Technology Data Exchange (ETDEWEB)

    Pedrozo Pupo, John C. (ed.) [Magdalena Univ., Santa Maria (Colombia). Respire - Inst. for Respiratory Care

    2013-03-01

    Useful learning tool for practitioners and students. Overview of the imaging techniques used in chest radiology. Aid to the correct interpretation of chest X-ray images. Radiology of the thorax forms an indispensable element of the basic diagnostic process for many conditions and is of key importance in a variety of medical disciplines. This user-friendly book provides an overview of the imaging techniques used in chest radiology and presents numerous instructive case-based images with accompanying explanatory text. A wide range of clinical conditions and circumstances are covered with the aim of enabling the reader to confidently interpret chest images by correctly identifying structures of interest and the causes of abnormalities. This book, which will be an invaluable learning tool, forms part of the Learning Imaging series for medical students, residents, less experienced radiologists, and other medical staff. Learning Imaging is a unique case-based series for those in professional education in general and for physicians in prarticular.

  3. Wide spectral band beam analysis

    Science.gov (United States)

    Aharon, Oren

    2015-03-01

    The reality in laser beam profiling is that measurements are performed over a wide spectrum of wavelengths and power ranges. Many applications use multiple laser wavelengths with very different power levels, a fact which dictates a need for a better measuring tool. Rapid progress in the fiber laser area has increased the demand for lasers in the wavelength range of 900 - 1030 nm, while the telecommunication market has increased the demand for wavelength range of 1300nm - 1600 nm, on the other hand the silicone chip manufacturing and mass production requirements tend to lower the laser wavelength towards the 190nm region. In many cases there is a need to combine several lasers together in order to perform a specific task. A typical application is to combine one visible laser for pointing, with a different laser for material processing with a very different wavelength and power level. The visible laser enables accurate pointing before the second laser is operated. The beam profile of the intensity distribution is an important parameter that indicates how a laser beam will behave in an application. Currently a lab, where many different lasers are used, will find itself using various laser beam profilers from several vendors with different specifications and accuracies. It is the propose of this article to present a technological breakthrough in the area of detectors, electronics and optics allowing intricate measurements of lasers with different wavelength and with power levels that vary many orders of magnitude by a single beam profiler.

  4. Wide area continuous offender monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Hoshen, J. [Lucent Technologies (United States); Drake, G. [New Mexico Dept. of Corrections, Santa Fe, NM (United States); Spencer, D. [Sandia National Labs., Albuquerque, NM (United States)

    1996-11-01

    The corrections system in the U.S. is supervising over five million offenders. This number is rising fast and so are the direct and indirect costs to society. To improve supervision and reduce the cost of parole and probation, first generation home arrest systems were introduced in 1987. While these systems proved to be helpful to the corrections system, their scope is rather limited because they only cover an offender at a single location and provide only a partial time coverage. To correct the limitations of first-generation systems, second-generation wide area continuous electronic offender monitoring systems, designed to monitor the offender at all times and locations, are now on the drawing board. These systems use radio frequency location technology to track the position of offenders. The challenge for this technology is the development of reliable personal locator devices that are small, lightweight, with long operational battery life, and indoors/outdoors accuracy of 100 meters or less. At the center of a second-generation system is a database that specifies the offender`s home, workplace, commute, and time the offender should be found in each. The database could also define areas from which the offender is excluded. To test compliance, the system would compare the observed coordinates of the offender with the stored location for a given time interval. Database logfiles will also enable law enforcement to determine if a monitored offender was present at a crime scene and thus include or exclude the offender as a potential suspect.

  5. Imaging in Psoriatic Arthritis

    DEFF Research Database (Denmark)

    Poggenborg, René Panduro; Østergaard, Mikkel; Terslev, Lene

    2015-01-01

    resonance imaging (MRI); other modalities such as computed tomography are not used routinely. Imaging is an integral part of management of PsA. In this article, we provide an overview of the status, virtues, and limitations of imaging modalities in PsA, focusing on radiography, US, and MRI.......Psoriatic arthritis (PsA) is an inflammatory joint disease characterized by arthritis and often enthesitis in patients with psoriasis, presenting a wide range of manifestations in various patterns. Imaging procedures are primarily conventional radiography, ultrasonography (US), and magnetic...

  6. Digital color imaging

    CERN Document Server

    Fernandez-Maloigne, Christine; Macaire, Ludovic

    2013-01-01

    This collective work identifies the latest developments in the field of the automatic processing and analysis of digital color images.For researchers and students, it represents a critical state of the art on the scientific issues raised by the various steps constituting the chain of color image processing.It covers a wide range of topics related to computational color imaging, including color filtering and segmentation, color texture characterization, color invariant for object recognition, color and motion analysis, as well as color image and video indexing and retrieval. <

  7. Unit 148 - World Wide Web Basics

    OpenAIRE

    148, CC in GIScience; Yeung, Albert K.

    2000-01-01

    This unit explains the characteristics and the working principles of the World Wide Web as the most important protocol of the Internet. Topics covered in this unit include characteristics of the World Wide Web; using the World Wide Web for the dissemination of information on the Internet; and using the World Wide Web for the retrieval of information from the Internet.

  8. A wide field of view plasma spectrometer

    Science.gov (United States)

    Skoug, R. M.; Funsten, H. O.; Möbius, E.; Harper, R. W.; Kihara, K. H.; Bower, J. S.

    2016-07-01

    We present a fundamentally new type of space plasma spectrometer, the wide field of view plasma spectrometer, whose field of view is > 1.25π ster using fewer resources than traditional methods. The enabling component is analogous to a pinhole camera with an electrostatic energy-angle filter at the image plane. Particle energy-per-charge is selected with a tunable bias voltage applied to the filter plate relative to the pinhole aperture plate. For a given bias voltage, charged particles from different directions are focused by different angles to different locations. Particles with appropriate locations and angles can transit the filter plate and are measured using a microchannel plate detector with a position-sensitive anode. Full energy and angle coverage are obtained using a single high-voltage power supply, resulting in considerable resource savings and allowing measurements at fast timescales. We present laboratory prototype measurements and simulations demonstrating the instrument concept and discuss optimizations of the instrument design for application to space measurements.

  9. Overview of Medical Imaging

    Science.gov (United States)

    Hendee, William

    2008-03-01

    The use of radiation probes to image tissues in the human body has progressed through an extraordinary evolution in the past three decades. Beginning with transmission computed tomography in the 1970s, this evolution has included real-time ultrasound, emission computed tomography, magnetic resonance imaging and digital radiography. These advances have recently yielded major improvements in imaging such as multi-detector transmission computed tomography, functional magnetic resonance imaging, dual imaging modalities built on a common platform, and image-guided intervention. These improvements and others have accelerated the usefulness of imaging methods in the early detection, definitive diagnosis, and effective intervention of a wide spectrum of diseases and disabilities. They also have led to increases in radiation doses to patients and the population, an issue of major concern to physicists and physicians. At this time there are four major frontiers for research in medical imaging: (1) molecular imaging; (2) functional imaging; (3) multi-modality imaging; and (4) information management. These research frontiers, together with the use of sophisticated imaging technologies in clinical practice, offer rich professional opportunities for physicists.

  10. Advanced MOKE magnetometry in wide-field Kerr-microscopy

    Science.gov (United States)

    Soldatov, I. V.; Schäfer, R.

    2017-10-01

    The measurement of MOKE (Magneto-Optical Kerr Effect) magnetization loops in a wide-field Kerr microscope offers the advantage that the relevant domain images along the loop can be readily recorded. As the microscope's objective lens is exposed to the magnetic field, the loops are usually strongly distorted by non-linear Faraday rotations of the polarized light that occur in the objective lens and that are superimposed to the MOKE signal. In this paper, an experimental method, based on a motorized analyzer, is introduced which allows to compensate the Faraday contributions, thus leading to pure MOKE loops. A wide field Kerr microscope, equipped with this technology, works well as a laser-based MOKE magnetometer, additionally offering domain images and thus providing the basis for loop interpretation.

  11. Printing images from the Web

    Science.gov (United States)

    Eschbach, Reiner

    2000-12-01

    Images have become ubiquitous, virtually every personal computer and every Internet WEB site contains at least some number of images. Professional as well as amateur artists display their work on the net and large image collections exist, spanning all aspects of art, hobby and daily life. The images vary widely in content, but more importantly, they also vary widely in general image quality attributes. Some of the quality variation is caused by the actual image creation or internet posting process, whereas some other quality variations are caused by the lack of defining image data description, like color-space definition. This paper describes problems and possible solutions associated with the printing of images from unknown sources.

  12. New Methods and Tools for the World Wide Web Search

    OpenAIRE

    Ceric, Vlatko

    2000-01-01

    Explosive growth of the World Wide Web as well as its heterogeneity call for powerful and easy to use search tools capable to provide the user with a moderate number of relevant answers. This paper presents analysis of key aspects of recently developed Web search methods and tools: visual representation of subject trees, interactive user interfaces, linguistic approaches, image search, ranking and grouping of search results, database search, and scientific information retrieval. Current trend...

  13. Photonics-based broadband radar for high-resolution and real-time inverse synthetic aperture imaging.

    Science.gov (United States)

    Zhang, Fangzheng; Guo, Qingshui; Wang, Ziqian; Zhou, Pei; Zhang, Guoqiang; Sun, Jun; Pan, Shilong

    2017-07-10

    A photonics-based radar with generation and de-chirp processing of broadband linear frequency modulated continuous-wave (LFMCW) signal in optical domain is proposed for high-resolution and real-time inverse synthetic aperture radar (ISAR) imaging. In the proposed system, a broadband LFMCW signal is generated by a photonic frequency quadrupler based on a single integrated electro-optical modulator, and the echoes reflected from the targets are de-chirped to a low frequency signal by a microwave photonic frequency mixer. The proposed radar can operate at a high frequency with a large bandwidth, and thus achieve an ultra-high range resolution for ISAR imaging. Thanks to the wideband photonic de-chirp technique, the radar receiver could apply low-speed analog-to-digital conversion and mature digital signal processing, which makes real-time ISAR imaging possible. A K-band photonics-based radar with an instantaneous bandwidth of 8 GHz (18-26 GHz) is established and its performance for ISAR imaging is experimentally investigated. Results show that a recorded two-dimensional imaging resolution of ~2 cm × ~2 cm is achieved with a sampling rate of 100 MSa/s in the receiver. Besides, fast ISAR imaging with 100 frames per second is verified. The proposed radar is an effective solution to overcome the limitations on operation bandwidth and processing speed of current radar imaging technologies, which may enable applications where high-resolution and real-time radar imaging is required.

  14. Histology on the World Wide Web: A Digest of Resources for Students and Teachers.

    Science.gov (United States)

    Cotter, John R.

    1997-01-01

    Provides a list of 37 World Wide Web sites that are devoted to instruction in histology and include electronic manuals, syllabi, atlases, image galleries, and quizzes. Reviews the topics, content, and highlights of these Web sites. (DDR)

  15. Hubble Space Telescope NICMOS observations of the host galaxies of powerful radio sources : Does size matter?

    NARCIS (Netherlands)

    de Vries, WH; O'Dea, CP; Barthel, PD; Fanti, C; Fanti, R; Lehnert, MD

    2000-01-01

    We present near-infrared J- and K-band imaging of a sample of powerful radio source host galaxies with the Hubble Space Telescope NICMOS2 camera. These sources have been selected on their double-lobed radio structure and include a wide range of projected radio source sizes. The largest projected

  16. Transformation of Cortex-wide Emergent Properties during Motor Learning.

    Science.gov (United States)

    Makino, Hiroshi; Ren, Chi; Liu, Haixin; Kim, An Na; Kondapaneni, Neehar; Liu, Xin; Kuzum, Duygu; Komiyama, Takaki

    2017-05-17

    Learning involves a transformation of brain-wide operation dynamics. However, our understanding of learning-related changes in macroscopic dynamics is limited. Here, we monitored cortex-wide activity of the mouse brain using wide-field calcium imaging while the mouse learned a motor task over weeks. Over learning, the sequential activity across cortical modules became temporally more compressed, and its trial-by-trial variability decreased. Moreover, a new flow of activity emerged during learning, originating from premotor cortex (M2), and M2 became predictive of the activity of many other modules. Inactivation experiments showed that M2 is critical for the post-learning dynamics in the cortex-wide activity. Furthermore, two-photon calcium imaging revealed that M2 ensemble activity also showed earlier activity onset and reduced variability with learning, which was accompanied by changes in the activity-movement relationship. These results reveal newly emergent properties of macroscopic cortical dynamics during motor learning and highlight the importance of M2 in controlling learned movements. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Computational methods for molecular imaging

    CERN Document Server

    Shi, Kuangyu; Li, Shuo

    2015-01-01

    This volume contains original submissions on the development and application of molecular imaging computing. The editors invited authors to submit high-quality contributions on a wide range of topics including, but not limited to: • Image Synthesis & Reconstruction of Emission Tomography (PET, SPECT) and other Molecular Imaging Modalities • Molecular Imaging Enhancement • Data Analysis of Clinical & Pre-clinical Molecular Imaging • Multi-Modal Image Processing (PET/CT, PET/MR, SPECT/CT, etc.) • Machine Learning and Data Mining in Molecular Imaging. Molecular imaging is an evolving clinical and research discipline enabling the visualization, characterization and quantification of biological processes taking place at the cellular and subcellular levels within intact living subjects. Computational methods play an important role in the development of molecular imaging, from image synthesis to data analysis and from clinical diagnosis to therapy individualization. This work will bring readers fro...

  18. Introducing Zoomify Image

    Directory of Open Access Journals (Sweden)

    Adam Smith

    2007-03-01

    Full Text Available Zoomify Image is a mature product for easily publishing large, high-resolution images on the Web. End users view these images with existing Webbrowser software as quickly as they do normal, downsampled images. A Flash-based Zoomifyer client asynchronously streams image data to the Web browser as needed, resulting in response times approaching those of desktop applications using minimal bandwidth. The author, a librarian at Cornell University and the principal architect of a small, open-source company, worked closely with Zoomify to produce a cross-platform, opensource implementation of that company’s image-processing software and discusses how to easily deploy the product into a widely used Webpublishing environment. Limitations are also discussed as are areas of improvement and alternatives.

  19. Imaging in nuclear medicine

    Energy Technology Data Exchange (ETDEWEB)

    Giussani, Augusto [BfS - Federal Office for Radiation Protection, Oberschleissheim (Germany). Dept. of Radiation Protection and Health; Hoeschen, Christoph (eds.) [Helmholtz Zentrum Muenchen - German Research Center for Environmental Health, Neuherberg (Germany). Research Unit Medical Raditation Physics and Diagnostics

    2013-08-01

    Presents the most recent developments in nuclear medicine imaging, with emphasis on the latest research findings. Considers the latest advances in imaging systems, image reconstruction, noise correction, and quality assurance. Discusses novel concepts, including those developed within the framework of the EURATOM FP7 MADEIRA project. Lists rules of thumb for imaging of use to both beginners and experienced researchers. This volume addresses a wide range of issues in the field of nuclear medicine imaging, with an emphasis on the latest research findings. Initial chapters set the scene by considering the role of imaging in nuclear medicine from the medical perspective and discussing the implications of novel agents and applications for imaging. The physics at the basis of the most modern imaging systems is described, and the reader is introduced to the latest advances in image reconstruction and noise correction. Various novel concepts are then discussed, including those developed within the framework of the EURATOM FP7 MADEIRA research project on the optimization of imaging procedures in order to permit a reduction in the radiation dose to healthy tissues. Advances in quality control and quality assurance are covered, and the book concludes by listing rules of thumb for imaging that will be of use to both beginners and experienced researchers.

  20. Fundamental mathematics and physics of medical imaging

    CERN Document Server

    Lancaster, Jack

    2016-01-01

    Authored by a leading educator, this book is ideal for medical imaging courses. Rather than focus on imaging modalities the book delves into the mechanisms of image formation and image quality common to all imaging systems: contrast mechanisms, noise, and spatial and temporal resolution. This is an extensively revised new edition of The Physics of Medical X-Ray Imaging by Bruce Hasegawa (Medical Physics Publishing, 1991). A wide range of modalities are covered including X-ray CT, MRI and SPECT.

  1. Gemini planet imager observational calibrations X: non-redundant masking on GPI

    Science.gov (United States)

    Greenbaum, Alexandra Z.; Cheetham, Anthony; Sivaramakrishnan, Anand; Tuthill, Peter; Norris, Barnaby; Pueyo, Laurent; Sadakuni, Naru; Rantakyrö, Fredrik; Hibon, Pascale; Goodsell, Stephen; Hartung, Markus; Serio, Andrew; Cardwell, Andrew; Poyneer, Lisa; Macintosh, Bruce; Savransky, Dmitry; Perrin, Marshall D.; Wolff, Schuyler; Ingraham, Patrick; Thomas, Sandrine

    2014-08-01

    The Gemini Planet Imager (GPI) Extreme Adaptive Optics Coronograph contains an interferometric mode: a 10-hole non-redundant mask (NRM) in its pupil wheel. GPI operates at Y, J, H, and K bands, using an integral field unit spectrograph (IFS) to obtain spectral data at every image pixel. NRM on GPI is capable of imaging with a half resolution element inner working angle at moderate contrast, probing the region behind the coronagraphic spot. The fine features of the NRM PSF can provide a reliable check on the plate scale, while also acting as an attenuator for spectral standard calibrators that would otherwise saturate the full pupil. NRM commissioning data provides details about wavefront error in the optics as well as operations of adaptive optics control without pointing control from the calibration system. We compare lab and on-sky results to evaluate systematic instrument properties and examine the stability data in consecutive exposures. We discuss early on-sky performance, comparing images from integration and tests with the first on-sky images, and demonstrate resolving a known binary. We discuss the status of NRM and implications for future science with this mode.

  2. Tourist destination image

    Directory of Open Access Journals (Sweden)

    Korićanin Maja

    2008-01-01

    Full Text Available In taking an advantages in tourism seems that image of specific tourist destination play an important role. This is very complex process but also a target for a wide list of potential stakeholders - not only organizations in this industry. Paper discuss a few relevant issues in connection to importance as well as development process of creating an image of tourist destination including well known Anhold model.

  3. Body Image

    Science.gov (United States)

    ... Blog About Us Contact Us Text size | Print | Body Image Developing a positive body image and a healthy mental attitude is crucial ... Read on for tips to have a healthy body image. Â Topics About body image When you ...

  4. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... wide range of conditions in children due to injury, illness or congenital abnormalities. When imaging of a child’s brain and spinal cord is needed, MRI is useful because of ...

  5. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... wide range of conditions in children due to injury, illness or congenital abnormalities. When imaging of a ... detect damage to the brain caused by an injury or a stroke diagnose infectious or autoimmune diseases ...

  6. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... wide range of conditions in children due to injury, illness or congenital abnormalities. When imaging of a child’s brain and spinal cord is needed, MRI is useful because of its ...

  7. Imaging the trigeminal nerve

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Alexandra [Radiology Department, Instituto Portugues de Oncologia Francisco Gentil, Centro de Lisboa, Rua Prof. Lima Basto, 1093, Lisboa (Portugal)], E-mail: borgalexandra@gmail.com; Casselman, Jan [Department of Radiology, A. Z. St Jan Brugge and A. Z. St Augustinus Antwerpen Hospitals (Belgium)

    2010-05-15

    Of all cranial nerves, the trigeminal nerve is the largest and the most widely distributed in the supra-hyoid neck. It provides sensory input from the face and motor innervation to the muscles of mastication. In order to adequately image the full course of the trigeminal nerve and its main branches a detailed knowledge of neuroanatomy and imaging technique is required. Although the main trunk of the trigeminal nerve is consistently seen on conventional brain studies, high-resolution tailored imaging is mandatory to depict smaller nerve branches and subtle pathologic processes. Increasing developments in imaging technique made possible isotropic sub-milimetric images and curved reconstructions of cranial nerves and their branches and led to an increasing recognition of symptomatic trigeminal neuropathies. Whereas MRI has a higher diagnostic yield in patients with trigeminal neuropathy, CT is still required to demonstrate the bony anatomy of the skull base and is the modality of choice in the context of traumatic injury to the nerve. Imaging of the trigeminal nerve is particularly cumbersome as its long course from the brainstem nuclei to the peripheral branches and its rich anastomotic network impede, in most cases, a topographic approach. Therefore, except in cases of classic trigeminal neuralgia, in which imaging studies can be tailored to the root entry zone, the full course of the trigeminal nerve has to be imaged. This article provides an update in the most recent advances on MR imaging technique and a segmental imaging approach to the most common pathologic processes affecting the trigeminal nerve.

  8. Tendon and ligament imaging

    Science.gov (United States)

    Hodgson, R J; O'Connor, P J; Grainger, A J

    2012-01-01

    MRI and ultrasound are now widely used for the assessment of tendon and ligament abnormalities. Healthy tendons and ligaments contain high levels of collagen with a structured orientation, which gives rise to their characteristic normal imaging appearances as well as causing particular imaging artefacts. Changes to ligaments and tendons as a result of disease and injury can be demonstrated using both ultrasound and MRI. These have been validated against surgical and histological findings. Novel imaging techniques are being developed that may improve the ability of MRI and ultrasound to assess tendon and ligament disease. PMID:22553301

  9. Large scale track analysis for wide area motion imagery surveillance

    Science.gov (United States)

    van Leeuwen, C. J.; van Huis, J. R.; Baan, J.

    2016-10-01

    Wide Area Motion Imagery (WAMI) enables image based surveillance of areas that can cover multiple square kilometers. Interpreting and analyzing information from such sources, becomes increasingly time consuming as more data is added from newly developed methods for information extraction. Captured from a moving Unmanned Aerial Vehicle (UAV), the high-resolution images allow detection and tracking of moving vehicles, but this is a highly challenging task. By using a chain of computer vision detectors and machine learning techniques, we are capable of producing high quality track information of more than 40 thousand vehicles per five minutes. When faced with such a vast number of vehicular tracks, it is useful for analysts to be able to quickly query information based on region of interest, color, maneuvers or other high-level types of information, to gain insight and find relevant activities in the flood of information. In this paper we propose a set of tools, combined in a graphical user interface, which allows data analysts to survey vehicles in a large observed area. In order to retrieve (parts of) images from the high-resolution data, we developed a multi-scale tile-based video file format that allows to quickly obtain only a part, or a sub-sampling of the original high resolution image. By storing tiles of a still image according to a predefined order, we can quickly retrieve a particular region of the image at any relevant scale, by skipping to the correct frames and reconstructing the image. Location based queries allow a user to select tracks around a particular region of interest such as landmark, building or street. By using an integrated search engine, users can quickly select tracks that are in the vicinity of locations of interest. Another time-reducing method when searching for a particular vehicle, is to filter on color or color intensity. Automatic maneuver detection adds information to the tracks that can be used to find vehicles based on their

  10. Stereoscopic Integrated Imaging Goggles for Multimodal Intraoperative Image Guidance.

    Directory of Open Access Journals (Sweden)

    Christopher A Mela

    Full Text Available We have developed novel stereoscopic wearable multimodal intraoperative imaging and display systems entitled Integrated Imaging Goggles for guiding surgeries. The prototype systems offer real time stereoscopic fluorescence imaging and color reflectance imaging capacity, along with in vivo handheld microscopy and ultrasound imaging. With the Integrated Imaging Goggle, both wide-field fluorescence imaging and in vivo microscopy are provided. The real time ultrasound images can also be presented in the goggle display. Furthermore, real time goggle-to-goggle stereoscopic video sharing is demonstrated, which can greatly facilitate telemedicine. In this paper, the prototype systems are described, characterized and tested in surgeries in biological tissues ex vivo. We have found that the system can detect fluorescent targets with as low as 60 nM indocyanine green and can resolve structures down to 0.25 mm with large FOV stereoscopic imaging. The system has successfully guided simulated cancer surgeries in chicken. The Integrated Imaging Goggle is novel in 4 aspects: it is (a the first wearable stereoscopic wide-field intraoperative fluorescence imaging and display system, (b the first wearable system offering both large FOV and microscopic imaging simultaneously,

  11. BMC Ecology image competition: the winning images.

    Science.gov (United States)

    Harold, Simon; Wong, Yan; Baguette, Michel; Bonsall, Michael B; Clobert, Jean; Royle, Nick J; Settele, Josef

    2013-03-22

    BMC Ecology announces the winning entries in its inaugural Ecology Image Competition, open to anyone affiliated with a research institute. The competition, which received more than 200 entries from international researchers at all career levels and a wide variety of scientific disciplines, was looking for striking visual interpretations of ecological processes. In this Editorial, our academic Section Editors and guest judge Dr Yan Wong explain what they found most appealing about their chosen winning entries, and highlight a few of the outstanding images that didn't quite make it to the top prize.

  12. BMC Ecology image competition: the winning images

    Science.gov (United States)

    2013-01-01

    BMC Ecology announces the winning entries in its inaugural Ecology Image Competition, open to anyone affiliated with a research institute. The competition, which received more than 200 entries from international researchers at all career levels and a wide variety of scientific disciplines, was looking for striking visual interpretations of ecological processes. In this Editorial, our academic Section Editors and guest judge Dr Yan Wong explain what they found most appealing about their chosen winning entries, and highlight a few of the outstanding images that didn’t quite make it to the top prize. PMID:23517630

  13. Region of Interest Selection Interface for Wide-Angle Arthroscope

    Directory of Open Access Journals (Sweden)

    Jung Kyunghwa

    2015-01-01

    Full Text Available We have proposed a new interface for an wide-angle endoscope for solo surgery. The wide-angle arthroscopic view and magnified region of interest (ROI within the wide view were shown simultaneously. With a camera affixed to surgical instruments, the position of the ROI could be determined by manipulating the surgical instrument. Image features acquired by the A-KAZE approach were used to estimate the change of position of the surgical instrument by tracking the features every time the camera moved. We examined the accuracy of ROI selection using three different images, which were different-sized square arrays and tested phantom experiments. When the number of ROIs was twelve, the success rate was best, and the rate diminished as the size of ROIs decreased. The experimental results showed that the method of using a camera without additional sensors satisfied the appropriate accuracy required for ROI selection, and this interface was helpful in performing surgery with fewer assistants.

  14. IMAGE QUATY ASSESSMENT FOR VHR REMOTE SENSING IMAGE CLASSIFICATION

    Directory of Open Access Journals (Sweden)

    Z. Li

    2016-06-01

    Full Text Available The data from remote sensing images are widely used for characterizing land use and land cover at present. With the increasing availability of very high resolution (VHR remote sensing images, the remote sensing image classification becomes more and more important for information extraction. The VHR remote sensing images are rich in details, but high within-class variance as well as low between-class variance make the classification of ground cover a difficult task. What’s more, some related studies show that the quality of VHR remote sensing images also has a great influence on the ability of the automatic image classification. Therefore, the research that how to select the appropriate VHR remote sensing images to meet the application of classification is of great significance. In this context, the factors of VHR remote sensing image classification ability are discussed and some indices are selected for describing the image quality and the image classification ability objectively. Then, we explore the relationship of the indices of image quality and image classification ability under a specific classification framework. The results of the experiments show that these image quality indices are not effective for indicating the image classification ability directly. However, according to the image quality metrics, we can still propose some suggestion for the application of classification.

  15. Pancreatitis-imaging approach

    Science.gov (United States)

    Busireddy, Kiran K; AlObaidy, Mamdoh; Ramalho, Miguel; Kalubowila, Janaka; Baodong, Liu; Santagostino, Ilaria; Semelka, Richard C

    2014-01-01

    Pancreatitis is defined as the inflammation of the pancreas and considered the most common pancreatic disease in children and adults. Imaging plays a significant role in the diagnosis, severity assessment, recognition of complications and guiding therapeutic interventions. In the setting of pancreatitis, wider availability and good image quality make multi-detector contrast-enhanced computed tomography (MD-CECT) the most used imaging technique. However, magnetic resonance imaging (MRI) offers diagnostic capabilities similar to those of CT, with additional intrinsic advantages including lack of ionizing radiation and exquisite soft tissue characterization. This article reviews the proposed definitions of revised Atlanta classification for acute pancreatitis, illustrates a wide range of morphologic pancreatic parenchymal and associated peripancreatic changes for different types of acute pancreatitis. It also describes the spectrum of early and late chronic pancreatitis imaging findings and illustrates some of the less common types of chronic pancreatitis, with special emphasis on the role of CT and MRI. PMID:25133027

  16. Amplitudes, acquisition and imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bloor, Robert

    1998-12-31

    Accurate seismic amplitude information is important for the successful evaluation of many prospects and the importance of such amplitude information is increasing with the advent of time lapse seismic techniques. It is now widely accepted that the proper treatment of amplitudes requires seismic imaging in the form of either time or depth migration. A key factor in seismic imaging is the spatial sampling of the data and its relationship to the imaging algorithms. This presentation demonstrates that acquisition caused spatial sampling irregularity can affect the seismic imaging and perturb amplitudes. Equalization helps to balance the amplitudes, and the dealing strategy improves the imaging further when there are azimuth variations. Equalization and dealiasing can also help with the acquisition irregularities caused by shot and receiver dislocation or missing traces. 2 refs., 2 figs.

  17. THE PDS 66 CIRCUMSTELLAR DISK AS SEEN IN POLARIZED LIGHT WITH THE GEMINI PLANET IMAGER

    Energy Technology Data Exchange (ETDEWEB)

    Wolff, Schuyler G.; Greenbaum, Alexandra Z. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Perrin, Marshall; Hines, Dean C. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Millar-Blanchaer, Maxwell A. [Department of Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3H4 (Canada); Nielsen, Eric L. [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305 (United States); Wang, Jason; Dong, Ruobing; Duchêne, Gaspard; Graham, James R.; Kalas, Paul [Astronomy Department, University of California, Berkeley, Berkeley, CA 94720 (United States); Cardwell, Andrew [LBT Observatory, University of Arizona, 933 N. Cherry Avenue, Room 552, Tucson, AZ 85721 (United States); Chilcote, Jeffrey [Dunlap Institute for Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3H4 (Canada); Draper, Zachary H. [University of Victoria, 3800 Finnerty Road, Victoria, BC V8P 5C2 (Canada); Fitzgerald, Michael P.; Hung, Li-Wei [Department of Physics and Astronomy, University of California, Los Angeles, 430 Portola Plaza, Los Angeles, CA 90095 (United States); Goodsell, Stephen J. [Gemini Observatory, 670 N. A’ohoku Place, Hilo, HI 96720 (United States); Grady, Carol A. [Eureka Scientific, 2452 Delmer, Suite 100, Oakland, CA 96002 (United States); Hartung, Markus; Hibon, Pascale, E-mail: swolff9@jh.edu [Gemini Observatory, Casilla 603, La Serena (Chile); and others

    2016-02-10

    We present H- and K-band imaging polarimetry for the PDS 66 circumstellar disk obtained during the commissioning of the Gemini Planet Imager (GPI). Polarization images reveal a clear detection of the disk in to the 0.″12 inner working angle (IWA) in the H band, almost three times closer to the star than the previous Hubble Space Telescope (HST) observations with NICMOS and STIS (0.″35 effective IWA). The centro-symmetric polarization vectors confirm that the bright inner disk detection is due to circumstellar scattered light. A more diffuse disk extends to a bright outer ring centered at 80 AU. We discuss several physical mechanisms capable of producing the observed ring + gap structure. GPI data confirm enhanced scattering on the east side of the disk that is inferred to be nearer to us. We also detect a lateral asymmetry in the south possibly due to shadowing from material within the IWA. This likely corresponds to a temporally variable azimuthal asymmetry observed in HST/STIS coronagraphic imaging.

  18. Versatile, Compact, Low-Cost, MEMS-Based Image Stabilization for Imaging Sensor Performance Enhancement Project

    Data.gov (United States)

    National Aeronautics and Space Administration — LW Microsystems proposes to develop a compact, low-cost image stabilization system suitable for use with a wide range of focal-plane imaging systems in remote...

  19. State machine replication for wide area networks

    OpenAIRE

    Mao, Yanhua

    2010-01-01

    State machine replication is the most general approach for providing highly available services with strong consistency guarantees. This dissertation studies protocols for implementing replicated state machines for wide area networks. First it demonstrates the challenges by comparing two protocols designed for local area networks in a cluster-based wide-area setting and shows that existing protocols designed for local area networks do not perform well in wide-area settings. A generic rotating ...

  20. Dynamical Imaging with Interferometry

    Science.gov (United States)

    Johnson, Michael D.; Bouman, Katherine L.; Blackburn, Lindy; Chael, Andrew A.; Rosen, Julian; Shiokawa, Hotaka; Roelofs, Freek; Akiyama, Kazunori; Fish, Vincent L.; Doeleman, Sheperd S.

    2017-12-01

    By linking widely separated radio dishes, the technique of very long baseline interferometry (VLBI) can greatly enhance angular resolution in radio astronomy. However, at any given moment, a VLBI array only sparsely samples the information necessary to form an image. Conventional imaging techniques partially overcome this limitation by making the assumption that the observed cosmic source structure does not evolve over the duration of an observation, which enables VLBI networks to accumulate information as Earth rotates and changes the projected array geometry. Although this assumption is appropriate for nearly all VLBI, it is almost certainly violated for submillimeter observations of the Galactic center supermassive black hole, Sagittarius A* (Sgr A*), which has a gravitational timescale of only ∼ 20 s and exhibits intrahour variability. To address this challenge, we develop several techniques to reconstruct dynamical images (“movies”) from interferometric data. Our techniques are applicable to both single-epoch and multiepoch variability studies, and they are suitable for exploring many different physical processes including flaring regions, stable images with small time-dependent perturbations, steady accretion dynamics, or kinematics of relativistic jets. Moreover, dynamical imaging can be used to estimate time-averaged images from time-variable data, eliminating many spurious image artifacts that arise when using standard imaging methods. We demonstrate the effectiveness of our techniques using synthetic observations of simulated black hole systems and 7 mm Very Long Baseline Array observations of M87, and we show that dynamical imaging is feasible for Event Horizon Telescope observations of Sgr A*.

  1. Automated medical image segmentation techniques

    Directory of Open Access Journals (Sweden)

    Sharma Neeraj

    2010-01-01

    Full Text Available Accurate segmentation of medical images is a key step in contouring during radiotherapy planning. Computed topography (CT and Magnetic resonance (MR imaging are the most widely used radiographic techniques in diagnosis, clinical studies and treatment planning. This review provides details of automated segmentation methods, specifically discussed in the context of CT and MR images. The motive is to discuss the problems encountered in segmentation of CT and MR images, and the relative merits and limitations of methods currently available for segmentation of medical images.

  2. Image Reconstruction for Prostate Specific Nuclear Medicine imagers

    Energy Technology Data Exchange (ETDEWEB)

    Mark Smith

    2007-01-11

    There is increasing interest in the design and construction of nuclear medicine detectors for dedicated prostate imaging. These include detectors designed for imaging the biodistribution of radiopharmaceuticals labeled with single gamma as well as positron-emitting radionuclides. New detectors and acquisition geometries present challenges and opportunities for image reconstruction. In this contribution various strategies for image reconstruction for these special purpose imagers are reviewed. Iterative statistical algorithms provide a framework for reconstructing prostate images from a wide variety of detectors and acquisition geometries for PET and SPECT. The key to their success is modeling the physics of photon transport and data acquisition and the Poisson statistics of nuclear decay. Analytic image reconstruction methods can be fast and are useful for favorable acquisition geometries. Future perspectives on algorithm development and data analysis for prostate imaging are presented.

  3. Flare Activity of Wide Binary Stars with Kepler

    Science.gov (United States)

    Clarke, Riley W.; Davenport, James R. A.; Covey, Kevin R.; Baranec, Christoph

    2018-01-01

    We present an analysis of flare activity in wide binary stars using a combination of value-added data sets from the NASA Kepler mission. The target list contains a set of previously discovered wide binary star systems identified by proper motions in the Kepler field. We cross-matched these systems with estimates of flare activity for ∼200,000 stars in the Kepler field, allowing us to compare relative flare luminosity between stars in coeval binaries. From a sample of 184 previously known wide binaries in the Kepler field, we find 58 with detectable flare activity in at least 1 component, 33 of which are similar in mass (q > 0.8). Of these 33 equal-mass binaries, the majority display similar (±1 dex) flare luminosity between both stars, as expected for stars of equal mass and age. However, we find two equal-mass pairs where the secondary (lower mass) star is more active than its counterpart, and two equal-mass pairs where the primary star is more active. The stellar rotation periods are also anomalously fast for stars with elevated flare activity. Pairs with discrepant rotation and activity qualitatively seem to have lower mass ratios. These outliers may be due to tidal spin-up, indicating these wide binaries could be hierarchical triple systems. We additionally present high-resolution adaptive optics images for two wide binary systems to test this hypothesis. The demographics of stellar rotation and magnetic activity between stars in wide binaries may be useful indicators for discerning the formation scenarios of these systems.

  4. Wide-Field Ultraviolet Spectrometer for Planetary Exospheres and Thermospheres

    Science.gov (United States)

    Fillingim, M. O.; Wishnow, E. H.; Miller, T.; Edelstein, J.; Lillis, R. J.; Korpela, E.; England, S.; Shourt, W. V.; Siegmund, O.; McPhate, J.; Courtade, S.; Curtis, D. W.; Deighan, J.; Chaffin, M.; Harmoul, A.; Almatroushi, H. R.

    2016-12-01

    Understanding the composition, structure, and variability of a planet's upper atmosphere - the exosphere and thermosphere - is essential for understanding how the upper atmosphere is coupled to the lower atmosphere, magnetosphere and near-space environment, and the Sun. Ultraviolet spectroscopy can directly observe emissions from constituents in the exosphere and thermosphere. From such observations, the structure, composition, and variability can be determined.We will present the preliminary design for a wide field ultraviolet imaging spectrometer for remote sensing of planetary atmospheres. The imaging spectrometer achieves an extremely large instantaneous 110 degree field of view with no moving scanning mirror. The imaging resolution is very appropriate for extended atmospheric emission studies, with a resolution of better than 0.3 degrees at the center to 0.4 degrees at the edges of the field. The spectral range covers 120 - 170 nm, encompassing emissions from H, O, C, N, CO, and N2, with an average spectral resolution of 1.5 nm. The instrument is composed of a 2-element wide-field telescope, a 3-element Offner spectrometer, and a sealed MCP detector system contained within a compact volume of about 40 x 25 x 20 cm. We will present the optical and mechanical design as well as the predicted optical performance.The wide instantaneous FOV simplifies instrument and spacecraft operations by removing the need for multiple scans (either from a scan mirror or spacecraft slews) to cover the regions of interest. This instrumentation can allow for two-dimensional spectral information to be built up with simple spacecraft operation or just using spacecraft motion. Applications to the terrestrial geocorona and thermosphere will be addressed as well as applications to the upper atmospheres of other planetary objects.

  5. Multispectral Imaging for Surveillance Applications

    OpenAIRE

    Riseby, Emil; Svensson, Alexander

    2015-01-01

    Silicon based sensors is a commonly used technology in digital cameras today. That has made such cameras relatively cheap and widely used. Unfortunately they are constructed to capture and represent image quality for humans. Several image applications work better without the restrictions of the visible spectrum. Human visual restrictions are often indirectly put on technology by using images showing only visible light. Thinking outside the box in this case is seeing beyond the visible spectrum.

  6. Wide-field subdiffraction RESOLFT microscopy using fluorescent protein photoswitching.

    Science.gov (United States)

    Schwentker, Miriam A; Bock, Hannes; Hofmann, Michael; Jakobs, Stefan; Bewersdorf, Jörg; Eggeling, Christian; Hell, Stefan W

    2007-03-01

    Subdiffraction fluorescence imaging is presented in a parallelized wide-field arrangement exploiting the principle of reversible saturable/switchable optical transitions (RESOLFT). The diffraction barrier is overcome by photoswitching ensembles of the label protein asFP595 between a nonfluorescent off- and a fluorescent on-state. Relying on ultralow continuous-wave intensities, reversible protein switching facilitates parallelized fast image acquisition. The RESOLFT principle is implemented by illuminating with intensity distributions featuring zero intensity lines that are further apart than the conventional Abbe resolution limit. The subdiffraction resolution is verified by recording live Escherichia coli bacteria labeled with asFP595. The obtained resolution of 50 nm ( approximately lambda/12) is limited only by the spectroscopic properties of the proteins and the imperfections of the optical implementation, but not on principle grounds. (c) 2007 Wiley-Liss, Inc.

  7. A wide-angle camera module for disposable endoscopy

    Science.gov (United States)

    Shim, Dongha; Yeon, Jesun; Yi, Jason; Park, Jongwon; Park, Soo Nam; Lee, Nanhee

    2016-08-01

    A wide-angle miniaturized camera module for disposable endoscope is demonstrated in this paper. A lens module with 150° angle of view (AOV) is designed and manufactured. All plastic injection-molded lenses and a commercial CMOS image sensor are employed to reduce the manufacturing cost. The image sensor and LED illumination unit are assembled with a lens module. The camera module does not include a camera processor to further reduce its size and cost. The size of the camera module is 5.5 × 5.5 × 22.3 mm3. The diagonal field of view (FOV) of the camera module is measured to be 110°. A prototype of a disposable endoscope is implemented to perform a pre-clinical animal testing. The esophagus of an adult beagle dog is observed. These results demonstrate the feasibility of a cost-effective and high-performance camera module for disposable endoscopy.

  8. Photometric Calibration of the Gemini South Adaptive Optics Imager

    Science.gov (United States)

    Stevenson, Sarah Anne; Rodrigo Carrasco Damele, Eleazar; Thomas-Osip, Joanna

    2017-01-01

    The Gemini South Adaptive Optics Imager (GSAOI) is an instrument available on the Gemini South telescope at Cerro Pachon, Chile, utilizing the Gemini Multi-Conjugate Adaptive Optics System (GeMS). In order to allow users to easily perform photometry with this instrument and to monitor any changes in the instrument in the future, we seek to set up a process for performing photometric calibration with standard star observations taken across the time of the instrument’s operation. We construct a Python-based pipeline that includes IRAF wrappers for reduction and combines the AstroPy photutils package and original Python scripts with the IRAF apphot and photcal packages to carry out photometry and linear regression fitting. Using the pipeline, we examine standard star observations made with GSAOI on 68 nights between 2013 and 2015 in order to determine the nightly photometric zero points in the J, H, Kshort, and K bands. This work is based on observations obtained at the Gemini Observatory, processed using the Gemini IRAF and gemini_python packages, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the National Research Council (Canada), CONICYT (Chile), Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina), and Ministério da Ciência, Tecnologia e Inovação (Brazil).

  9. Wireless Wide Area Networks for School Districts.

    Science.gov (United States)

    Nair, Prakash

    This paper considers a basic question that many schools districts face in attempting to develop affordable, expandable district-wide computer networks that are resistant to obsolescence: Should these wide area networks (WANs) employ wireless technology, stick to venerable hard-wired solutions, or combine both. This publication explores the…

  10. Michelson wide-field stellar interferometry

    NARCIS (Netherlands)

    Montilla, I.

    2004-01-01

    The main goal of this thesis is to develop a system to permit wide field operation of Michelson Interferometers. A wide field of view is very important in applications such as the observation of extended or multiple objects, the fringe acquisition and/ or tracking on a nearby unresolved object, and

  11. Two Objections to Wide-Scoping

    NARCIS (Netherlands)

    Evers, Daan

    2011-01-01

    Wide-scopers argue that the detachment of intuitively false ‘ought’ claims from hypothetical imperatives is blocked because ‘ought’ takes wide, as opposed to narrow, scope. I present two arguments against this view. The first questions the premise that natural language conditionals are true just in

  12. Management van World-Wide Web Servers

    NARCIS (Netherlands)

    van Hengstum, F.P.H.; Pras, Aiko

    1996-01-01

    Het World Wide Web is een populaire Internet toepassing waarmee het mogelijk is documenten aan willekeurige Internet gebruikers aan te bieden. Omdat hiervoor nog geen voorzieningen zijn getroffen, was het tot voor kort niet goed mogelijk het World Wide Web op afstand te beheren. De Universiteit

  13. Innovation in Science Education - World-Wide.

    Science.gov (United States)

    Baez, Albert V.

    The purpose of this book is to promote improvements in science education, world-wide, but particularly in developing countries. It is addressed to those in positions to make effective contributions to the improvement of science education. The world-wide role of science education, the goals of innovative activities, past experience in efforts to…

  14. Image Statistics

    Energy Technology Data Exchange (ETDEWEB)

    Wendelberger, Laura Jean [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-08

    In large datasets, it is time consuming or even impossible to pick out interesting images. Our proposed solution is to find statistics to quantify the information in each image and use those to identify and pick out images of interest.

  15. Image Guidance

    Science.gov (United States)

    Guidance that explains the process for getting images approved in One EPA Web microsites and resource directories. includes an appendix that shows examples of what makes some images better than others, how some images convey meaning more than others

  16. Consistency in the World Wide Web

    DEFF Research Database (Denmark)

    Thomsen, Jakob Grauenkjær

    Tim Berners-Lee envisioned that computers will behave as agents of humans on the World Wide Web, where they will retrieve, extract, and interact with information from the World Wide Web. A step towards this vision is to make computers capable of extracting this information in a reliable...... and consistent way. In this dissertation we study steps towards this vision by showing techniques for the specication, the verication and the evaluation of the consistency of information in the World Wide Web. We show how to detect certain classes of errors in a specication of information, and we show how...... the World Wide Web, in order to help perform consistent evaluations of web extraction techniques. These contributions are steps towards having computers reliable and consistently extract information from the World Wide Web, which in turn are steps towards achieving Tim Berners-Lee's vision. ii...

  17. Identification of neural outgrowth genes using genome-wide RNAi.

    Directory of Open Access Journals (Sweden)

    Katharine J Sepp

    2008-07-01

    Full Text Available While genetic screens have identified many genes essential for neurite outgrowth, they have been limited in their ability to identify neural genes that also have earlier critical roles in the gastrula, or neural genes for which maternally contributed RNA compensates for gene mutations in the zygote. To address this, we developed methods to screen the Drosophila genome using RNA-interference (RNAi on primary neural cells and present the results of the first full-genome RNAi screen in neurons. We used live-cell imaging and quantitative image analysis to characterize the morphological phenotypes of fluorescently labelled primary neurons and glia in response to RNAi-mediated gene knockdown. From the full genome screen, we focused our analysis on 104 evolutionarily conserved genes that when downregulated by RNAi, have morphological defects such as reduced axon extension, excessive branching, loss of fasciculation, and blebbing. To assist in the phenotypic analysis of the large data sets, we generated image analysis algorithms that could assess the statistical significance of the mutant phenotypes. The algorithms were essential for the analysis of the thousands of images generated by the screening process and will become a valuable tool for future genome-wide screens in primary neurons. Our analysis revealed unexpected, essential roles in neurite outgrowth for genes representing a wide range of functional categories including signalling molecules, enzymes, channels, receptors, and cytoskeletal proteins. We also found that genes known to be involved in protein and vesicle trafficking showed similar RNAi phenotypes. We confirmed phenotypes of the protein trafficking genes Sec61alpha and Ran GTPase using Drosophila embryo and mouse embryonic cerebral cortical neurons, respectively. Collectively, our results showed that RNAi phenotypes in primary neural culture can parallel in vivo phenotypes, and the screening technique can be used to identify many new

  18. Structure from motion with wide circular field of view cameras.

    Science.gov (United States)

    Micusík, Branislav; Pajdla, Tomás

    2006-07-01

    This paper presents a method for fully automatic and robust estimation of two-view geometry, autocalibration, and 3D metric reconstruction from point correspondences in images taken by cameras with wide circular field of view. We focus on cameras which have more than 180 degrees field of view and for which the standard perspective camera model is not sufficient, e.g., the cameras equipped with circular fish-eye lenses Nikon FC-E8 (183 degrees), Sigma 8mm-f4-EX (180 degrees), or with curved conical mirrors. We assume a circular field of view and axially symmetric image projection to autocalibrate the cameras. Many wide field of view cameras can still be modeled by the central projection followed by a nonlinear image mapping. Examples are the above-mentioned fish-eye lenses and properly assembled catadioptric cameras with conical mirrors. We show that epipolar geometry of these cameras can be estimated from a small number of correspondences by solving a polynomial eigenvalue problem. This allows the use of efficient RANSAC robust estimation to find the image projection model, the epipolar geometry, and the selection of true point correspondences from tentative correspondences contaminated by mismatches. Real catadioptric cameras are often slightly noncentral. We show that the proposed autocalibration with approximate central models is usually good enough to get correct point correspondences which can be used with accurate noncentral models in a bundle adjustment to obtain accurate 3D scene reconstruction. Noncentral camera models are dealt with and results are shown for catadioptric cameras with parabolic and spherical mirrors.

  19. Intuitionistic fuzzy approach in enhancing image of flat EEG

    Science.gov (United States)

    Zenian, Suzelawati; Ahmad, Tahir; Idris, Amidora

    2014-07-01

    Image enhancement is a process to improve the quality of an image which mainly due to presence of noise. It is an initial step in medical imaging. Fuzzy approach has been used widely in the area of image processing. However, in this paper, image enhancement of Flat EEG (fEEG) during epileptic seizures using intuitionistic fuzzy set (IFS) is presented and compared.

  20. ROI-ORIENTATED SENSOR CORRECTION BASED ON VIRTUAL STEADY REIMAGING MODEL FOR WIDE SWATH HIGH RESOLUTION OPTICAL SATELLITE IMAGERY

    Directory of Open Access Journals (Sweden)

    Y. Zhu

    2017-09-01

    Full Text Available To meet the requirement of high accuracy and high speed processing for wide swath high resolution optical satellite imagery under emergency situation in both ground processing system and on-board processing system. This paper proposed a ROI-orientated sensor correction algorithm based on virtual steady reimaging model for wide swath high resolution optical satellite imagery. Firstly, the imaging time and spatial window of the ROI is determined by a dynamic search method. Then, the dynamic ROI sensor correction model based on virtual steady reimaging model is constructed. Finally, the corrected image corresponding to the ROI is generated based on the coordinates mapping relationship which is established by the dynamic sensor correction model for corrected image and rigours imaging model for original image. Two experimental results show that the image registration between panchromatic and multispectral images can be well achieved and the image distortion caused by satellite jitter can be also corrected efficiently.

  1. An Evolutionary Algorithm for Enhanced Magnetic Resonance Imaging Classification

    OpenAIRE

    T.S. Murunya; S. Audithan

    2014-01-01

    This study presents an image classification method for retrieval of images from a multi-varied MRI database. With the development of sophisticated medical imaging technology which helps doctors in diagnosis, medical image databases contain a huge amount of digital images. Magnetic Resonance Imaging (MRI) is a widely used imaging technique which picks signals from a body's magnetic particles spinning to magnetic tune and through a computer converts scanned data into pictures of internal organs...

  2. Noise Removal in SAR Images using Orthonormal Ridgelet Transform

    OpenAIRE

    A. Ravi,; Dr. P.V.Naganjaneyulu

    2015-01-01

    Development in the field of image processing for reducing speckle noise from digital images/satellite images is a challenging task for image processing applications. Previously many algorithms were proposed to de-speckle the noise in digital images. Here in this article we are presenting experimental results on de-speckling of Synthetic Aperture RADAR (SAR) images. SAR images have wide applications in remote sensing and mapping the surfaces of all planets. SAR can also be implemen...

  3. Learning musculoskeletal imaging

    Energy Technology Data Exchange (ETDEWEB)

    Vilanova, Joan C. (eds.) [Girona Univ. (Spain). Clinica Girona; Ribes, Ramon

    2010-07-01

    This introduction to musculoskeletal imaging is a further volume in the Learning Imaging series. Written in a user-friendly format, it takes into account that musculoskeletal radiology is a subspecialty which has widely expanded its scope and imaging capabilities with the advent of ultrasound, MRI, multidetector CT, and PET. The book is divided into ten sections covering: infection and arthritis, tumors, tendons and muscles, bone marrow, spine, shoulder, elbow, hand and wrist, hip and pelvis, knee, and ankle and foot. Each chapter is presented with an introduction and ten case studies with illustrations and comments from anatomical, physiopathological and radiological standpoints along with bibliographic recommendations. Learning Imaging is a unique case-based series for those in professional education in general and for physicians in particular. (orig.)

  4. The World Wide Web of War

    National Research Council Canada - National Science Library

    Smith, Craig A

    2006-01-01

    Modern communications, combined with the near instantaneous publication of information on the World Wide Web, are providing the means to dramatically affect the pursuit, conduct, and public opinion of war on both sides...

  5. Wide Bandgap Nanostructured Space Photovoltaics Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Firefly, in collaboration with Rochester Institute of Technology, proposes an STTR program for the development of a wide-bandgap GaP-based space solar cell capable...

  6. Final Range Wide Environmental Impact Statement

    National Research Council Canada - National Science Library

    Botdorf, Charles

    2001-01-01

    This Final Range Wide Environmental Impact Statement presents the impacts associated with the direct, indirect, and cumulative effects of mission diversification and changes to land use for Yuma Proving Ground, Arizona...

  7. Tomographic imaging in CWI: Algorithms and applications

    NARCIS (Netherlands)

    H.H. Der Sarkissian (Henri)

    2018-01-01

    textabstractTomography is a widely used imaging tool to explore the 3D inner structure of object without having to cut it open using penetrating beams. In this talk, I will present the different aspects of tomographic imaging handled and developed at the Computational Imaging group in CWI,

  8. Image processing

    NARCIS (Netherlands)

    van der Heijden, Ferdinand; Spreeuwers, Lieuwe Jan; Blanken, Henk; Vries de, A.P.; Blok, H.E.; Feng, L; Feng, L.

    2007-01-01

    The field of image processing addresses handling and analysis of images for many purposes using a large number of techniques and methods. The applications of image processing range from enhancement of the visibility of cer- tain organs in medical images to object recognition for handling by

  9. Image city

    DEFF Research Database (Denmark)

    2003-01-01

    Image city exhibition explores a condition of mediation, through a focus on image and sound narratives with a point of departure on a number of Asian cities.......Image city exhibition explores a condition of mediation, through a focus on image and sound narratives with a point of departure on a number of Asian cities....

  10. AA, assembly of wide bending magnet

    CERN Multimedia

    CERN PhotoLab

    1980-01-01

    The very particular lattice of the AA required 2 types of dipoles (bending magnets; BST, short and wide; BLG, long and narrow). The wide ones had a steel length of 2.71 m, a "good field" width of 0.564 m, and a weight of about 75 t. Here we see the copper coils being hoisted onto the lower half of a BST. See also 7811105, 8006050. For a BLG, see 8001044.

  11. AA, wide quadrupole on measurement stand

    CERN Multimedia

    CERN PhotoLab

    1981-01-01

    Please look up 8101024 first. Shims and washers on the wide quadrupoles (QFW, QDW; located in the lattice where dispersion was large) served mostly for corrections of those lattice parameters which were a function of momentum. After mounting shims and washers, the quadrupoles were measured to determine their magnetic centre and to catalogue the effect of washer constellations. Raymond Brown is busy measuring a wide quad.

  12. Emergency Medicine for medical students world wide!

    DEFF Research Database (Denmark)

    Perinpam, Larshan; Thi Huynh, Anh-Nhi

    2015-01-01

    A guest blog from Larshan Perinpam (President of ISAEM) and Anh-Nhi Thi Huynh (Vice president of external affairs, ISAEM) - http://blogs.bmj.com/emj/2015/04/17/emergency-medicine-for-medical-students-world-wide/......A guest blog from Larshan Perinpam (President of ISAEM) and Anh-Nhi Thi Huynh (Vice president of external affairs, ISAEM) - http://blogs.bmj.com/emj/2015/04/17/emergency-medicine-for-medical-students-world-wide/...

  13. Wooden Model of Wide AA Bending Magnet

    CERN Multimedia

    CERN PhotoLab

    1978-01-01

    The very particular lattice of the AA required 2 types of dipoles (bending magnets: BLG, long and narrow; BST, short and wide). The wide ones had a steel length of 2.71 m, a "good field" width of 0.564 m, and a weight of about 75 t. Here we see a wooden model, built in 1978, to gain dimensional experience with such a monster.

  14. Pixel History for Advanced Camera for Surveys Wide Field Channel

    Science.gov (United States)

    Borncamp, D.; Grogin, N.; Bourque, M.; Ogaz, S.

    2017-06-01

    Excess thermal energy present in a Charged Coupled Device (CCD) can result in additional electrical current. This excess charge is trapped within the silicon lattice structure of the CCD electronics. It can persist through multiple exposures and have an adverse effect on science performance of the detectors unless properly flagged and corrected for. The traditional way to correct for this extra charge is to take occasional long-exposure images with the camera shutter closed. These images, generally referred to as "dark" images, allow for the measurement of the thermal-electron contamination present in each pixel of the CCD lattice. This so-called "dark current" can then be subtracted from the science images by re-scaling the dark to the corresponding exposure times. Pixels that have signal above a certain threshold are traditionally marked as "hot" and flagged in the data quality array. Many users will discard these because of the extra current. However, these pixels may not be unusable because of an unreliable dark subtraction; if we find these pixels to be stable over an anneal period, we can properly subtract the charge and the extra Poisson noise from this dark current will be propagated into the error arrays. Here we present the results of a pixel history study that analyzes every individual pixel of the Hubble Space Telescope's (HST) Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) CCDs over time and allows pixels that were previously flagged as unusable to be brought back into the science image as a reliable pixel.

  15. A novel digital shearography with wide angle of view for nondestructive inspection

    Science.gov (United States)

    Wu, Sijin; Yang, Lianxiang

    2011-05-01

    Digital shearography is widely accepted in non-destructive inspection of honeycomb sandwich structures due to its advantages of validity, non-contact, simple setup and robustness. In digital shearography, Michelson shear interferometer (MSI) is a dominant shearing device because it is easy to change the shearing amount and direction. However, the conventional digital shearography based on MSI suffers from the small angle of view which limits its employments in full field inspection of a big size sample at a short working distance. A novel structure digital shearography with wide angle of view introduced in this paper is developed to overcome the disadvantage. In the new shearography optical arrangement, the image lens is separated with the camera and locates at the front of system. A 4f imaging system is used to transmit the image of object from the imaging lens to the camera. The shearing device, MSI, locates between the imaging lens and camera. The angle of view in this shearography has no limit to the setup but it is based on several parameters, such as the focus length of the imaging lens and the size of the imaging device inside the camera. Thus wide angle of view can be easily achieved by changing those parameters. Using this novel digital shearography, full field inspection of the big size honeycomb sandwich structure can be rapidly conducted at a short working distance.

  16. DMD-based programmable wide field spectrograph for Earth observation

    Science.gov (United States)

    Zamkotsian, Frédéric; Lanzoni, Patrick; Liotard, Arnaud; Viard, Thierry; Costes, Vincent; Hébert, Philippe-Jean

    2015-03-01

    In Earth Observation, Universe Observation and Planet Exploration, scientific return could be optimized in future missions using MOEMS devices. In Earth Observation, we propose an innovative reconfigurable instrument, a programmable wide-field spectrograph where both the FOV and the spectrum could be tailored thanks to a 2D micromirror array (MMA). For a linear 1D field of view (FOV), the principle is to use a MMA to select the wavelengths by acting on intensity. This component is placed in the focal plane of a first grating. On the MMA surface, the spatial dimension is along one side of the device and for each spatial point, its spectrum is displayed along the perpendicular direction: each spatial and spectral feature of the 1D FOV is then fully adjustable dynamically and/or programmable. A second stage with an identical grating recomposes the beam after wavelengths selection, leading to an output tailored 1D image. A mock-up has been designed, fabricated and tested. The micromirror array is the largest DMD in 2048 x 1080 mirrors format, with a pitch of 13.68μm. A synthetic linear FOV is generated and typical images have been recorded o at the output focal plane of the instrument. By tailoring the DMD, we could modify successfully each pixel of the input image: for example, it is possible to remove bright objects or, for each spatial pixel, modify the spectral signature. The very promising results obtained on the mock-up of the programmable wide-field spectrograph reveal the efficiency of this new instrument concept for Earth Observation.

  17. The development of WIFIS: a wide integral field infrared spectrograph

    Science.gov (United States)

    Sivanandam, Suresh; Chou, Richard C. Y.; Moon, Dae-Sik; Ma, Ke; Millar-Blanchaer, Maxwell; Eikenberry, Stephen S.; Chun, Moo-Young; Kim, Sang Chul; Raines, Steven N.; Eisner, Joshua

    2012-09-01

    We present the current results from the development of a wide integral field infrared spectrograph (WIFIS). WIFIS offers an unprecedented combination of etendue and spectral resolving power for seeing-limited, integral field observations in the 0.9 - 1.8 μm range and is most sensitive in the 0.9 - 1.35 μ,m range. Its optical design consists of front-end re-imaging optics, an all-reflective image slicer-type, integral field unit (IFU) called FISICA, and a long-slit grating spectrograph back-end that is coupled with a HAWAII 2RG focal plane array. The full wavelength range is achieved by selecting between two different gratings. By virtue of its re-imaging optics, the spectrograph is quite versatile and can be used at multiple telescopes. The size of its field-of-view is unrivalled by other similar spectrographs, offering a 4.511x 1211 integral field at a 10-meter class telescope (or 2011 x 5011 at a 2.3-meter telescope). The use of WIFIS will be crucial in astronomical problems which require wide-field, two-dimensional spectroscopy such as the study of merging galaxies at moderate redshift and nearby star/planet-forming regions and supernova remnants. We discuss the final optical design of WIFIS, and its predicted on-sky performance on two reference telescope platforms: the 2.3-m Steward Bok telescope and the 10.4-m Gran Telescopio Canarias. We also present the results from our laboratory characterization of FISICA. IFU properties such as magnification, field-mapping, and slit width along the entire slit length were measured by our tests. The construction and testing of WIFIS is expected to be completed by early 2013. We plan to commission the instrument at the 2.3-m Steward Bok telescope at Kitt Peak, USA in Spring 2013.

  18. Imaging with Raman spectroscopy.

    Science.gov (United States)

    Zhang, Yin; Hong, Hao; Cai, Weibo

    2010-09-01

    Raman spectroscopy, based on the inelastic scattering of a photon, has been widely used as an analytical tool in many research fields. Recently, Raman spectroscopy has also been explored for biomedical applications (e.g. cancer diagnosis) because it can provide detailed information on the chemical composition of cells and tissues. For imaging applications, several variations of Raman spectroscopy have been developed to enhance its sensitivity. This review article will provide a brief summary of Raman spectroscopy-based imaging, which includes the use of coherent anti-Stokes Raman spectroscopy (CARS, primarily used for imaging the C-H bond in lipids), surface-enhanced Raman spectroscopy (SERS, for which a variety of nanoparticles can be used as contrast agents), and single-walled carbon nanotubes (SWNTs, with its intrinsic Raman signal). The superb multiplexing capability of SERS-based Raman imaging can be extremely powerful in future research where different agents can be attached to different Raman tags to enable the interrogation of multiple biological events simultaneously in living subjects. The primary limitations of Raman imaging in humans are those also faced by other optical techniques, in particular limited tissue penetration. Over the last several years, Raman spectroscopy imaging has advanced significantly and many critical proof-of-principle experiments have been successfully carried out. It is expected that imaging with Raman Spectroscopy will continue to be a dynamic research field over the next decade.

  19. Brain Image Motion Correction

    DEFF Research Database (Denmark)

    Jensen, Rasmus Ramsbøl; Benjaminsen, Claus; Larsen, Rasmus

    2015-01-01

    The application of motion tracking is wide, including: industrial production lines, motion interaction in gaming, computer-aided surgery and motion correction in medical brain imaging. Several devices for motion tracking exist using a variety of different methodologies. In order to use such devices...... offset and tracking noise in medical brain imaging. The data are generated from a phantom mounted on a rotary stage and have been collected using a Siemens High Resolution Research Tomograph for positron emission tomography. During acquisition the phantom was tracked with our latest tracking prototype...

  20. Imaging of shoulder instability

    Science.gov (United States)

    Martínez Martínez, Alberto; Tomás Muñoz, Pablo; Pozo Sánchez, José; Zarza Pérez, Antonio

    2017-01-01

    This extended review tries to cover the imaging findings of the wide range of shoulder injuries secondary to shoulder joint instability. Usefulness of the different imaging methods is stressed, including radiography, computed tomography (CT) and magnetic resonance. The main topics to be covered include traumatic, atraumatic and minor instability syndromes. Radiography may show bone abnormalities associated to instability, including developmental and post-traumatic changes. CT is the best technique depicting and quantifying skeletal changes. MR-arthrography is the main tool in diagnosing the shoulder instability injuries. PMID:28932699

  1. Radiometric calibration of wide-field camera system with an application in astronomy

    Science.gov (United States)

    Vítek, Stanislav; Nasyrova, Maria; Stehlíková, Veronika

    2017-09-01

    Camera response function (CRF) is widely used for the description of the relationship between scene radiance and image brightness. Most common application of CRF is High Dynamic Range (HDR) reconstruction of the radiance maps of imaged scenes from a set of frames with different exposures. The main goal of this work is to provide an overview of CRF estimation algorithms and compare their outputs with results obtained under laboratory conditions. These algorithms, typically designed for multimedia content, are unfortunately quite useless with astronomical image data, mostly due to their nature (blur, noise, and long exposures). Therefore, we propose an optimization of selected methods to use in an astronomical imaging application. Results are experimentally verified on the wide-field camera system using Digital Single Lens Reflex (DSLR) camera.

  2. Imaging angiogenesis.

    Science.gov (United States)

    Charnley, Natalie; Donaldson, Stephanie; Price, Pat

    2009-01-01

    There is a need for direct imaging of effects on tumor vasculature in assessment of response to antiangiogenic drugs and vascular disrupting agents. Imaging tumor vasculature depends on differences in permeability of vasculature of tumor and normal tissue, which cause changes in penetration of contrast agents. Angiogenesis imaging may be defined in terms of measurement of tumor perfusion and direct imaging of the molecules involved in angiogenesis. In addition, assessment of tumor hypoxia will give an indication of tumor vasculature. The range of imaging techniques available for these processes includes positron emission tomography (PET), dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), perfusion computed tomography (CT), and ultrasound (US).

  3. Imaging of renal osteodystrophy

    Energy Technology Data Exchange (ETDEWEB)

    Jevtic, V. E-mail: vladimir.jevtic@mf.uni-lj.si

    2003-05-01

    Chronic renal insufficiency, hemodialysis, peritoneal dialysis, renal transplantation and administration of different medications provoke complex biochemical disturbances of the calcium-phosphate metabolism with wide spectrum of bone and soft tissue abnormalities termed renal osteodystrophy. Clinically most important manifestation of renal bone disease includes secondary hyperparathyroidism, osteomalacia/rickets, osteoporosis, adynamic bone disease and soft tissue calcification. As a complication of long-term hemodialysis and renal transplantation amyloid deposition, destructive spondyloarthropathy, osteonecrosis, and musculoskeletal infections may occur. Due to more sophisticated diagnostic methods and more efficient treatment classical radiographic features of secondary hyperparathyroidism and osteomalacia/rickets are now less frequently seen. Radiological investigations play an important role in early diagnosis and follow-up of the renal bone disease. Although numerous new imaging modalities have been introduced in clinical practice (scintigraphy, CT, MRI, quantitative imaging), plain film radiography, especially fine quality hand radiograph, still represents most widely used examination.

  4. Wide-field surface-enhanced CARS microscopy of cells (Conference Presentation)

    Science.gov (United States)

    Fast, Alexander; Kenison, John T.; Potma, Eric O.

    2017-02-01

    We have previously demonstrated a total internal reflection, wide-field CARS microscope, where the signal is enhanced with the aid of a thin gold layer that supports surface plasmon polariton resonances. This surface-enhanced CARS microscope is capable of generating images of lipid structures in close proximity (visualizing lipids in aqueous media, including imaging of cells, with a unique surface-sensitive contrast that cannot be obtained with conventional CARS microscopy.

  5. Digital demodulator for wide bandwidth SAR

    DEFF Research Database (Denmark)

    Jørgensen, Jørn Hjelm

    2000-01-01

    A novel approach to the design of efficient digital quadrature demodulators for wide bandwidth SAR systems is described. Efficiency is obtained by setting the intermediate frequency to 1/4 the ADC sampling frequency. One channel is made filter-free by synchronizing the local oscillator with the o......A novel approach to the design of efficient digital quadrature demodulators for wide bandwidth SAR systems is described. Efficiency is obtained by setting the intermediate frequency to 1/4 the ADC sampling frequency. One channel is made filter-free by synchronizing the local oscillator...

  6. Wooden Model of Wide AA Bending Magnet

    CERN Multimedia

    CERN PhotoLab

    1978-01-01

    The very particular lattice of the AA required 2 types of dipoles (bending magnets: BLG, long and narrow; BST, short and wide). A wide one had a steel length of 2.71 m, a "good field" width of 0.564 m, and a weight of about 75 t. A wooden model was build in 1978, to gain dimensional experience. Here, Peter Zettwoch, one of the largest men at CERN at that time, is putting a hand in the mouth of the wooden BST monster.

  7. Genome-wide association study of pathological gambling.

    Science.gov (United States)

    Lang, M; Leménager, T; Streit, F; Fauth-Bühler, M; Frank, J; Juraeva, D; Witt, S H; Degenhardt, F; Hofmann, A; Heilmann-Heimbach, S; Kiefer, F; Brors, B; Grabe, H-J; John, U; Bischof, A; Bischof, G; Völker, U; Homuth, G; Beutel, M; Lind, P A; Medland, S E; Slutske, W S; Martin, N G; Völzke, H; Nöthen, M M; Meyer, C; Rumpf, H-J; Wurst, F M; Rietschel, M; Mann, K F

    2016-08-01

    Pathological gambling is a behavioural addiction with negative economic, social, and psychological consequences. Identification of contributing genes and pathways may improve understanding of aetiology and facilitate therapy and prevention. Here, we report the first genome-wide association study of pathological gambling. Our aims were to identify pathways involved in pathological gambling, and examine whether there is a genetic overlap between pathological gambling and alcohol dependence. Four hundred and forty-five individuals with a diagnosis of pathological gambling according to the Diagnostic and Statistical Manual of Mental Disorders were recruited in Germany, and 986 controls were drawn from a German general population sample. A genome-wide association study of pathological gambling comprising single marker, gene-based, and pathway analyses, was performed. Polygenic risk scores were generated using data from a German genome-wide association study of alcohol dependence. No genome-wide significant association with pathological gambling was found for single markers or genes. Pathways for Huntington's disease (P-value=6.63×10(-3)); 5'-adenosine monophosphate-activated protein kinase signalling (P-value=9.57×10(-3)); and apoptosis (P-value=1.75×10(-2)) were significant. Polygenic risk score analysis of the alcohol dependence dataset yielded a one-sided nominal significant P-value in subjects with pathological gambling, irrespective of comorbid alcohol dependence status. The present results accord with previous quantitative formal genetic studies which showed genetic overlap between non-substance- and substance-related addictions. Furthermore, pathway analysis suggests shared pathology between Huntington's disease and pathological gambling. This finding is consistent with previous imaging studies. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  8. Spinal imaging and image analysis

    CERN Document Server

    Yao, Jianhua

    2015-01-01

    This book is instrumental to building a bridge between scientists and clinicians in the field of spine imaging by introducing state-of-the-art computational methods in the context of clinical applications.  Spine imaging via computed tomography, magnetic resonance imaging, and other radiologic imaging modalities, is essential for noninvasively visualizing and assessing spinal pathology. Computational methods support and enhance the physician’s ability to utilize these imaging techniques for diagnosis, non-invasive treatment, and intervention in clinical practice. Chapters cover a broad range of topics encompassing radiological imaging modalities, clinical imaging applications for common spine diseases, image processing, computer-aided diagnosis, quantitative analysis, data reconstruction and visualization, statistical modeling, image-guided spine intervention, and robotic surgery. This volume serves a broad audience as  contributions were written by both clinicians and researchers, which reflects the inte...

  9. Image denoising using cloud images

    Science.gov (United States)

    Yue, Huanjing; Sun, Xiaoyan; Yang, Jingyu; Wu, Feng

    2013-09-01

    Image denoising manages to recover a digital image from its noisy version by exploring the statistical features inside a given noisy image. Most denoising methods perform well at low noise levels but lose efficiency at higher ones. In this paper, we propose a novel image denoising method, which restores an image by exploiting the correlations between the noisy image and the images retrieved from the cloud. Given a noisy image, we first retrieve relevant images based on feature-level similarity. These images are then geometrically aligned to the noisy image to increase global statistical correlation. Using the aligned images as references, we propose recovering the image with patch-level noise removal. For each noisy patch, we first retrieve similar patches from the references and stack these patches (including the noisy one) into a three dimensional (3D) group. We then obtain the noise free (NF) patches by collaborative filtering over the 3D groups. These recovered NF patches are aggregated together, producing the desired NF image. Experimental results demonstrate that our scheme achieves significantly better results compared to state-of-the-art methods in terms of both objective and subjective qualities.

  10. Systems, computer-implemented methods, and tangible computer-readable storage media for wide-field interferometry

    Science.gov (United States)

    Lyon, Richard G. (Inventor); Leisawitz, David T. (Inventor); Rinehart, Stephen A. (Inventor); Memarsadeghi, Nargess (Inventor)

    2012-01-01

    Disclosed herein are systems, computer-implemented methods, and tangible computer-readable storage media for wide field imaging interferometry. The method includes for each point in a two dimensional detector array over a field of view of an image: gathering a first interferogram from a first detector and a second interferogram from a second detector, modulating a path-length for a signal from an image associated with the first interferogram in the first detector, overlaying first data from the modulated first detector and second data from the second detector, and tracking the modulating at every point in a two dimensional detector array comprising the first detector and the second detector over a field of view for the image. The method then generates a wide-field data cube based on the overlaid first data and second data for each point. The method can generate an image from the wide-field data cube.

  11. Wide Area Wind Field Monitoring Status & Results

    Energy Technology Data Exchange (ETDEWEB)

    Alan Marchant; Jed Simmons

    2011-09-30

    Volume-scanning elastic has been investigated as a means to derive 3D dynamic wind fields for characterization and monitoring of wind energy sites. An eye-safe volume-scanning lidar system was adapted for volume imaging of aerosol concentrations out to a range of 300m. Reformatting of the lidar data as dynamic volume images was successfully demonstrated. A practical method for deriving 3D wind fields from dynamic volume imagery was identified and demonstrated. However, the natural phenomenology was found to provide insufficient aerosol features for reliable wind sensing. The results of this study may be applicable to wind field measurement using injected aerosol tracers.

  12. Visibility retrieval in Michelson wide-field stellar interferometry

    Science.gov (United States)

    Montilla, I.; Sellos, J.; Pereira, S. F.; Braat, J. J. M.

    2006-04-01

    Wide-field interferometry has become a subject of increasing interest in recent years. New methods have been suggested in order to avoid the drawbacks of the standard wide-field method (homothetic mapping), which is not applicable when the aperture is highly diluted; for this reason, imaging with non-homothetic arrays is being extensively studied (E. Pedretti, et al., Astron. Astrophys. Suppl. Ser. 147 285 (2000); S. Gillet, et al., Astron. Astrophys. 400 393 (2003)). The field of view of a pupil-plane interferometer or a densified array consists of only a few resolution elements; in order to improve these systems, we have developed a new method consisting of a Michelson pupil-plane combination scheme where a wide field of view can be achieved in one shot. This technique, called the ‘staircase mirror’ approach, has been described in a previous paper (I. Montilla, S.F. Pereira and J.J.M. Braat, Appl. Optics 44 328 (2005)) and uses a stair-shaped mirror in the intermediate image plane of each telescope in the array, allowing for simultaneous correction of the differential delay for both the on- and off-axis image positions. Experimental results have been obtained showing the simultaneous recovery of the fringes of off-axis stars with an appreciable angular separation, and with a contrast similar to that of the on-axis reference star. With this example we demonstrate an increase of the field of view by a factor of 5, with no need for extra observation time. In this article, we present a further analysis of the method. We investigate how to retrieve the visibility when a star is focused on the edge of a step of the stair-shaped mirror. Even though the optical pathlength difference correction is discontinuous, we show both numerically and analytically that the visibility can be completely recovered, so that no information is lost. Our experimental results demonstrate that the visibility can be retrieved to within a 1% error.

  13. School-Wide Discipline and Classroom Ecology.

    Science.gov (United States)

    Marr, Mary Beth; Audette, Bob; White, Richard; Ellis, Edward; Algozzine, Bob

    2002-01-01

    Shortages of teachers with specialized skills, coupled with increased difficulty accommodating students with problem behaviors in general education classrooms, create pressures for performance and accountability in schools. Describes improvements in classroom ecology after implementation of a school-wide discipline model. These outcomes were…

  14. Re-Framing the World Wide Web

    Science.gov (United States)

    Black, August

    2011-01-01

    The research presented in this dissertation studies and describes how technical standards, protocols, and application programming interfaces (APIs) shape the aesthetic, functional, and affective nature of our most dominant mode of online communication, the World Wide Web (WWW). I examine the politically charged and contentious battle over browser…

  15. AA, wide quadrupole on measurement stand

    CERN Multimedia

    CERN PhotoLab

    1981-01-01

    Please look up 8101024 and 8103203 first. Wide quadrupole (QFW, QDW) with end-shims and shimming washers on the measurement stand. With the measurement coil one measured the harmonics of the magnetic field, determined the magnetic centre, and catalogued the effect of washer constellations.

  16. Enterprise-Wide Process & Performance Excellence:

    DEFF Research Database (Denmark)

    Edgeman, Rick; Kristensen, Kai; Eskildsen, Jacob Kjær

    2013-01-01

    Program value proposition, content, organization, and strategy are elaborated herein. This elaboration is the result of careful study of business and social trends, along with careful listening to collaborating enterprises. It is in this latter sense that the Enterprise-Wide Process & Performance...

  17. Inbreeding in genome-wide selection

    NARCIS (Netherlands)

    Daetwyler, H.D.; Villanueva, B.; Bijma, P.; Woolliams, J.A.

    2007-01-01

    Traditional selection methods, such as sib and best linear unbiased prediction (BLUP) selection, which increased genetic gain by increasing accuracy of evaluation have also led to an increased rate of inbreeding per generation (¿FG). This is not necessarily the case with genome-wide selection, which

  18. Welcome to the World-Wide Web.

    Science.gov (United States)

    Davis, Philip

    1995-01-01

    World Wide Web (WWW) is a multimedia, globally distributed, client/server information system based on hypertext. WWW browser software (Mosaic, Cello, and Samba) allows users to navigate hypertext documents via the Internet. Libraries are taking advantage of the fact that hypertext linked documents can be easily and inexpensively shared. (JMV)

  19. Happy 20th Birthday, World Wide Web!

    CERN Multimedia

    2009-01-01

    On 13 March CERN celebrated the 20th anniversary of the World Wide Web. Check out the video interview with Web creator Tim Berners-Lee and find out more about the both the history and future of the Web. To celebrate CERN also launched a brand new website, CERNland, for kids.

  20. Internet and The World Wide Web

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 2. Internet and The World Wide Web. Neelima Shrikhande. General Article Volume 2 Issue 2 February 1997 pp 64-74. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/002/02/0064-0074 ...

  1. The LOFT wide field monitor simulator

    DEFF Research Database (Denmark)

    Donnarumma, I.; Evangelista, Y.; Campana, R.

    2012-01-01

    We present the simulator we developed for the Wide Field Monitor (WFM) aboard the Large Observatory For Xray Timing (LOFT) mission, one of the four ESA M3 candidate missions considered for launch in the 2022–2024 timeframe. The WFM is designed to cover a large FoV in the same bandpass as the Larg...

  2. Proteome-Wide Quantitation by SILAC

    DEFF Research Database (Denmark)

    Rigbolt, Kristoffer T G; Blagoev, Blagoy

    2010-01-01

    Ongoing improvements in instrumentation, fractionation techniques, and enrichment procedures have dramatically increased the coverage of the proteome achievable via LC-MS/MS-based methodologies, opening the call for approaches to quantitatively assess differences at a proteome-wide scale. Stable...

  3. So Wide a Web, So Little Time.

    Science.gov (United States)

    McConville, David; And Others

    1996-01-01

    Discusses new trends in the World Wide Web. Highlights include multimedia; digitized audio-visual files; compression technology; telephony; virtual reality modeling language (VRML); open architecture; and advantages of Java, an object-oriented programming language, including platform independence, distributed development, and pay-per-use software.…

  4. Manual Colostomy Reversals Following Wide Colorectal Resections ...

    African Journals Online (AJOL)

    Manual Colostomy Reversals Following Wide Colorectal Resections at Poorly Equipped Surgical Facilities. EBFK Odimba, M Nthele, M Mbambiko. Abstract. Background: The decision for colostomy reversal is usually not easy and often reflects patient's desire, fully analyzed and agreed by the surgeon. The unavailability of ...

  5. Microwave imaging

    CERN Document Server

    Pastorino, Matteo

    2010-01-01

    An introduction to the most relevant theoretical and algorithmic aspects of modern microwave imaging approaches Microwave imaging-a technique used in sensing a given scene by means of interrogating microwaves-has recently proven its usefulness in providing excellent diagnostic capabilities in several areas, including civil and industrial engineering, nondestructive testing and evaluation, geophysical prospecting, and biomedical engineering. Microwave Imaging offers comprehensive descriptions of the most important techniques so far proposed for short-range microwave imaging-in

  6. Image reconstruction method IRBis for optical/infrared long-baseline interferometry

    Science.gov (United States)

    Hofmann, Karl-Heinz; Heininger, Matthias; Schertl, Dieter; Weigelt, Gerd; Millour, Florentin; Berio, Philippe

    2016-07-01

    IRBis is an image reconstruction method for optical/infrared long-baseline interferometry. IRBis can reconstruct images from (a) measured visibilities and closure phases, or from (b) measured complex visibilities (i.e. the Fourier phases and visibilities). The applied optimization routine ASA CG is based on conjugate gradients. The method allows the user to implement different regularizers, as for example, maximum entropy, smoothness, total variation, etc., and apply residual ratios as an additional metric for goodness-of-fit. In addition, IRBis allows the user to change the following reconstruction parameters: (a) FOV of the area to be reconstructed, (b) the size of the pixel-grid used, (c) size of a binary mask in image space allowing reconstructed intensities real astronomical objects: (a) We have investigated image reconstruction experiments of MATISSE target candidates by computer simulations. We have modeled gaps in a disk of a young stellar object and have simulated interferometric data (squared visibilities and closure phases) with a signal-to-noise ratio as expected for MATISSE observations. We have performed image reconstruction experiments with this model for different flux levels of the target and different amount of observing time, that is, with different uv coverages. As expected, the quality of the reconstructions clearly depends on the flux of the source and the completeness of the uv coverage. (b) We also discuss reconstructions of the Luminous Blue Variable η Carinae obtained from AMBER observations in the high spectral resolution mode in the K band. The images were reconstruction (1) using the closure phases and (2) using the absolute phases derived from the measured wavelength-differential phases and the closure phase reconstruction in the continuum.

  7. Image blur

    Energy Technology Data Exchange (ETDEWEB)

    Nissen, M.R.

    1993-04-01

    The image blur in a photograph is produced by the exposure of a moving object. Knowing the amount of image blur is important for recording useful data. If there is too much blur, it becomes hard to make quantitative measurements. This report discusses image blur, the parameters used to control it, and how to calculate it.

  8. The image of accountants

    DEFF Research Database (Denmark)

    Baldvinsdottir, Gudrun; Burns, John; Nørreklit, Hanne

    2009-01-01

    the accountant appeared as a more hedonistic person. Overall, the changes observed reflect changes in wider social practice from modernity, through high modernity, to hyper-modernity. Research limitations/implications - The image of the accountants has implications for the development of the accounting......, and whether the image produced reflects a wide social change in society. Findings - It was found that in the 1970s and the 1980s the accountant was constructed as a responsible and rational person. In the 1990s, the accountant was presented as an instructed action man. However, in a recent advert...... of accountants, particularly in the media and popular movies, extant works have mostly investigated how others perceive accountants and how accountants are generally portrayed. The paper however, places more stress on the construction of the image of the accountants when appealing to the accountants....

  9. Micropower impulse radar imaging

    Energy Technology Data Exchange (ETDEWEB)

    Hall, M.S.

    1995-11-01

    From designs developed at the Lawrence Livermore National Laboratory (LLNL) in radar and imaging technologies, there exists the potential for a variety of applications in both public and private sectors. Presently tests are being conducted for the detection of buried mines and the analysis of civil structures. These new systems use a patented ultra-wide band (impulse) radar technology known as Micropower Impulse Radar (GPR) imaging systems. LLNL has also developed signal processing software capable of producing 2-D and 3-D images of objects embedded in materials such as soil, wood and concrete. My assignment while at LLNL has focused on the testing of different radar configurations and applications, as well as assisting in the creation of computer algorithms which enable the radar to scan target areas of different geometeries.

  10. Simultaneous in vivo positron emission tomography and magnetic resonance imaging

    OpenAIRE

    Catana, Ciprian; Procissi, Daniel; Wu, Yibao; Judenhofer, Martin S.; Qi, Jinyi; Pichler, Bernd J.; Jacobs, Russell E.; Cherry, Simon R.

    2008-01-01

    Positron emission tomography (PET) and magnetic resonance imaging (MRI) are widely used in vivo imaging technologies with both clinical and biomedical research applications. The strengths of MRI include high-resolution, high-contrast morphologic imaging of soft tissues; the ability to image physiologic parameters such as diffusion and changes in oxygenation level resulting from neuronal stimulation; and the measurement of metabolites using chemical shift imaging. PET images the distribution o...

  11. Thermal design of the Wide Field/Planetary Camera

    Science.gov (United States)

    Garcia, R. D.; Jones, J. A.; Stultz, J. W.

    1989-01-01

    The Wide Field/Planetary Camera is an imaging system developed by the Jet Propulsion Laboratory for the NASA Hubble Space Telescope currently scheduled to be launched in December 1989 aboard the space shuttle. The temperature control design of the instrument utilizes multilayered insulation, electric resistance heaters, aluminum/ammonia heat pipes, thermoelectric coolers, temperature control coatings, and space radiators. A feedback control system maintains stable sensor temperatures. Thermal capacitance maintains stable optics and electronics temperatures during transient conditions. Schedule slips and launch delays have allowed extensive thermal testing of the instrument. Six instrument thermal vacuum tests and a spacecraft thermal vacuum test were performed. Several modifications have been made to the instrument to correct icing and contamination problems that have been discovered during thermal vacuum testing. This paper describes the thermal design, last instrument thermal vacuum test, results, and thermal model correlation.

  12. Broadband Wide Angle Lens Implemented with Dielectric Metamaterials

    Directory of Open Access Journals (Sweden)

    Anthony Starr

    2011-08-01

    Full Text Available The Luneburg lens is a powerful imaging device, exhibiting aberration free focusing for parallel rays incident from any direction. However, its advantages are offset by a focal surface that is spherical and thus difficult to integrate with standard planar detector and emitter arrays. Using the recently developed technique of transformation optics, it is possible to transform the curved focal surface to a flat plane while maintaining the perfect focusing behavior of the Luneburg over a wide field of view. Here we apply these techniques to a lesser-known refractive Luneburg lens and implement the design with a metamaterial composed of a semi-crystalline distribution of holes drilled in a dielectric. In addition, we investigate the aberrations introduced by various approximations made in the implementation of the lens. The resulting design approach has improved mechanical strength with small aberrations and is ideally suited to implementation at infrared and visible wavelengths.

  13. Blind deconvolution with principal components analysis for wide-field and small-aperture telescopes

    Science.gov (United States)

    Jia, Peng; Sun, Rongyu; Wang, Weinan; Cai, Dongmei; Liu, Huigen

    2017-09-01

    Telescopes with a wide field of view (greater than 1°) and small apertures (less than 2 m) are workhorses for observations such as sky surveys and fast-moving object detection, and play an important role in time-domain astronomy. However, images captured by these telescopes are contaminated by optical system aberrations, atmospheric turbulence, tracking errors and wind shear. To increase the quality of images and maximize their scientific output, we propose a new blind deconvolution algorithm based on statistical properties of the point spread functions (PSFs) of these telescopes. In this new algorithm, we first construct the PSF feature space through principal component analysis, and then classify PSFs from a different position and time using a self-organizing map. According to the classification results, we divide images of the same PSF types and select these PSFs to construct a prior PSF. The prior PSF is then used to restore these images. To investigate the improvement that this algorithm provides for data reduction, we process images of space debris captured by our small-aperture wide-field telescopes. Comparing the reduced results of the original images and the images processed with the standard Richardson-Lucy method, our method shows a promising improvement in astrometry accuracy.

  14. Spatially Resolved Two-Dimensional Infrared Spectroscopy via Wide-Field Microscopy.

    Science.gov (United States)

    Ostrander, Joshua S; Serrano, Arnaldo L; Ghosh, Ayanjeet; Zanni, Martin T

    2016-07-20

    We report the first wide-field microscope for measuring two-dimensional infrared (2D IR) spectroscopic images. We concurrently collect more than 16 000 2D IR spectra, made possible by a new focal plane array detector and mid-IR pulse shaping, to generate hyperspectral images with multiple frequency dimensions and diffraction-limited spatial resolution. Both frequency axes of the spectra are collected in the time domain by scanning two pairs of femtosecond pulses using a dual acousto-optic modulator pulse shaper. The technique is demonstrated by imaging a mixture of metal carbonyl absorbed polystyrene beads. The differences in image formation between FTIR and 2D IR microscopy are also explored by imaging a patterned USAF test target. We find that our 2D IR microscope has diffraction-limited spatial resolution and enhanced contrast compared to FTIR microscopy because of the nonlinear scaling of the 2D IR signal to the absorptivity coefficient for the vibrational modes. Images generated using off-diagonal peaks, created from vibrational anharmonicities, improve the molecular discrimination and eliminate noise. Two-dimensional wide-field IR microscopy provides information on vibrational lifetimes, molecular couplings, transition dipole orientations, and many other quantities that can be used for creating image contrast to help disentangle and interpret complex and heterogeneous samples. Such experiments made possible could include the study of amyloid proteins in tissues, protein folding in heterogeneous environments, and structural dynamics in devices employing mid-IR materials.

  15. Chapter 11: Genome-wide association studies.

    Directory of Open Access Journals (Sweden)

    William S Bush

    Full Text Available Genome-wide association studies (GWAS have evolved over the last ten years into a powerful tool for investigating the genetic architecture of human disease. In this work, we review the key concepts underlying GWAS, including the architecture of common diseases, the structure of common human genetic variation, technologies for capturing genetic information, study designs, and the statistical methods used for data analysis. We also look forward to the future beyond GWAS.

  16. Wide bandgap matrix switcher, amplifier and oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Sampayan, Stephen

    2016-08-16

    An electronic device comprising an optical gate, an electrical input an electrical output and a wide bandgap material positioned between the electrical input and the electrical output to control an amount of current flowing between the electrical input and the electrical output in response to a stimulus received at the optical gate can be used in wideband telecommunication applications in transmission of multi-channel signals.

  17. Requirements for company-wide management

    Science.gov (United States)

    Southall, J. W.

    1980-01-01

    Computing system requirements were developed for company-wide management of information and computer programs in an engineering data processing environment. The requirements are essential to the successful implementation of a computer-based engineering data management system; they exceed the capabilities provided by the commercially available data base management systems. These requirements were derived from a study entitled The Design Process, which was prepared by design engineers experienced in development of aerospace products.

  18. 256-slice wide-detector computed tomography.

    Science.gov (United States)

    2007-11-01

    This article provides opinions and predictions about an emerging technology-256-slice wide-detector computed tomography-to help healthcare facilities decide whether the technology is worth tracking and when it might be ready for adoption. We believe 256-slice CT is worth monitoring based on its predicted clinical and business impact. We consider it unlikely, however, that more than a few select facilities will begin adopting this technology within the next three years.

  19. A Genome-Wide Perspective on Metabolism

    DEFF Research Database (Denmark)

    Rauch, Alexander; Mandrup, Susanne

    2015-01-01

    number of technologies that can be used to obtain genome-wide insight into how genomes are reprogrammed during development and in response to specific external signals. By applying such technologies, we have begun to reveal the cross-talk between metabolism and the genome, i.e., how genomes...... are reprogrammed in response to metabolites, and how the regulation of metabolic networks is coordinated at the genomic level....

  20. Epigenome-Wide Association Study of Wellbeing.

    Science.gov (United States)

    Baselmans, Bart M L; van Dongen, Jenny; Nivard, Michel G; Lin, Bochao D; Zilhão, Nuno R; Boomsma, Dorret I; Bartels, Meike

    2015-12-01

    Wellbeing (WB) is a major topic of research across several scientific disciplines, partly driven by its strong association with psychological and mental health. Twin-family studies have found that both genotype and environment play an important role in explaining the variance in WB. Epigenetic mechanisms, such as DNA methylation, regulate gene expression, and may mediate genetic and environmental effects on WB. Here, for the first time, we apply an epigenome-wide association study (EWAS) approach to identify differentially methylated sites associated with individual differences in WB. Subjects were part of the longitudinal survey studies of the Netherlands Twin Register (NTR) and participated in the NTR biobank project between 2002 and 2011. WB was assessed by a short inventory that measures satisfaction with life (SAT). DNA methylation was measured in whole blood by the Illumina Infinium HumanMethylation450 BeadChip (HM450k array) and the association between WB and DNA methylation level was tested at 411,169 autosomal sites. Two sites (cg10845147, p = 1.51 * 10(-8) and cg01940273, p = 2.34 * 10(-8)) reached genome-wide significance following Bonferonni correction. Four more sites (cg03329539, p = 2.76* 10(-7); cg09716613, p = 3.23 * 10(-7); cg04387347, p = 3.95 * 10(-7); and cg02290168, p = 5.23 * 10(-7)) were considered to be genome-wide significant when applying the widely used criterion of a FDR q value system categories among higher-ranking methylation sites. Overall, these results provide a first insight into the epigenetic mechanisms associated with WB and lay the foundations for future work aiming to unravel the biological mechanisms underlying a complex trait like WB.

  1. Community relations via the World Wide Web

    Energy Technology Data Exchange (ETDEWEB)

    Gossman, D.G.; Gossman, S.E. [Gossman Consulting, Inc., Hampshire, IL (United States)

    1998-12-31

    The Internet or world wide web provides an unprecedented opportunity to communicate with the public and improve community relations. By providing a Virtual Plant Tour{trademark} and important environmental plans and reports on line, industry can short circuit the rumor mill and provide information to the local community, regulatory officials, and the world at large. Audience, content, maintenance, design considerations and costs are all examined.

  2. Objective and expert-independent validation of retinal image registration algorithms by a projective imaging distortion model

    NARCIS (Netherlands)

    Lee, Sangyeol; Reinhardt, Joseph M.; Cattin, Philippe C.; Abramoff, M.D.

    2010-01-01

    Fundus camera imaging of the retina is widely used to diagnose and manage ophthalmologic disorders including diabetic retinopathy, glaucoma, and age-related macular degeneration. Retinal images typically have a limited field of view, and multiple images can be joined together using an image

  3. A hierarchical SVG image abstraction layer for medical imaging

    Science.gov (United States)

    Kim, Edward; Huang, Xiaolei; Tan, Gang; Long, L. Rodney; Antani, Sameer

    2010-03-01

    As medical imaging rapidly expands, there is an increasing need to structure and organize image data for efficient analysis, storage and retrieval. In response, a large fraction of research in the areas of content-based image retrieval (CBIR) and picture archiving and communication systems (PACS) has focused on structuring information to bridge the "semantic gap", a disparity between machine and human image understanding. An additional consideration in medical images is the organization and integration of clinical diagnostic information. As a step towards bridging the semantic gap, we design and implement a hierarchical image abstraction layer using an XML based language, Scalable Vector Graphics (SVG). Our method encodes features from the raw image and clinical information into an extensible "layer" that can be stored in a SVG document and efficiently searched. Any feature extracted from the raw image including, color, texture, orientation, size, neighbor information, etc., can be combined in our abstraction with high level descriptions or classifications. And our representation can natively characterize an image in a hierarchical tree structure to support multiple levels of segmentation. Furthermore, being a world wide web consortium (W3C) standard, SVG is able to be displayed by most web browsers, interacted with by ECMAScript (standardized scripting language, e.g. JavaScript, JScript), and indexed and retrieved by XML databases and XQuery. Using these open source technologies enables straightforward integration into existing systems. From our results, we show that the flexibility and extensibility of our abstraction facilitates effective storage and retrieval of medical images.

  4. Thermal imaging in medicine

    Directory of Open Access Journals (Sweden)

    Jaka Ogorevc

    2015-12-01

    be widely used also in the field of medicine. Implementation of every new technology in a daily clinical practice requires large number of measurements with such equipment compared by reference method for the purpose of clinical validation. The knowledge of measurement problematics is crucial. Collaboration between physicians and engineers on multi- and interdisciplinary level is of high importance for thermal imaging to win confidence of physicians and to gain reliability as a clinical diagnostic tool.

  5. Wide-field interferometric phase microscopy with molecular specificity using plasmonic nanoparticles.

    Science.gov (United States)

    Turko, Nir A; Peled, Anna; Shaked, Natan T

    2013-11-01

    We present a method for adding molecular specificity to wide-field interferometric phase microscopy (IPM) by recording the phase signatures of gold nanoparticles (AuNPs) labeling targets of interest in biological cells. The AuNPs are excited by time-modulated light at a wavelength corresponding to their absorption spectral peak, evoking a photothermal (PT) effect due to their plasmonic resonance. This effect induces a local temperature rise, resulting in local refractive index and phase changes that can be detected optically. Using a wide-field interferometric phase microscope, we acquired an image sequence of the AuNP sample phase profile without requiring lateral scanning, and analyzed the time-dependent profile of the entire field of view using a Fourier analysis, creating a map of the locations of AuNPs in the sample. The system can image a wide-field PT phase signal from a cluster containing down to 16 isolated AuNPs. AuNPs are then conjugated to epidermal growth factor receptor (EGFR) antibodies and inserted to an EGFR-overexpressing cancer cell culture, which is imaged using IPM and verified by confocal microscopy. To the best of our knowledge, this is the first time wide-field interferometric PT imaging is performed at the subcellular level without the need for total internal reflection effects or scanning.

  6. Vehicle tracking in wide area motion imagery from an airborne platform

    NARCIS (Netherlands)

    Eekeren, A.W.M. van; Huis, J.R. van; Eendebak, P.T.; Baan, J.

    2015-01-01

    Airborne platforms, such as UAV's, with Wide Area Motion Imagery (WAMI) sensors can cover multiple square kilometers and produce large amounts of video data. Analyzing all data for information need purposes becomes increasingly labor-intensive for an image analyst. Furthermore, the capacity of the

  7. Predicting the behaviour of a wide sandwich beam under pressure loading

    NARCIS (Netherlands)

    Davies, P.; Bigourdan, B.; Chaudot, P.; Choqueuse, D.; Ferreira, A.; Karjalainen, J.P.; Hildebrand, M.; Mustakangas, M.; Gaarder, R.; Carli, F.; Straalen, IJ.J. van; Sargent, J.P.; Adams, R.D.; Broughton, J.; Beevers, A.

    2000-01-01

    This paper presents results from analytical and finite elenent modelling of the response of a wide foam core sandwich beam to uniform pressure loading. New tests have been performed using an image analysis system which allows core shear strain mapping. Predicted panel displacenpnts and strains are

  8. EVIDENCE FOR INTERMEDIATE-AGE STELLAR POPULATIONS IN EARLY-TYPE GALAXIES FROM K-BAND SPECTROSCOPY

    NARCIS (Netherlands)

    Marmol-Queralto, E.; Cardiel, N.; Sanchez-Blazquez, P.; Trager, S. C.; Peletier, R. F.; Kuntschner, H.; Silva, D. R.; Cenarro, A. J.; Vazdekis, A.; Gorgas, J.

    2009-01-01

    The study of stellar populations in early-type galaxies in different environments is a powerful tool for constraining their star formation histories. This study has been traditionally restricted to the optical range, where dwarfs around the turn-off and stars at the base of the red giant branch

  9. Detecting metal-rich intermediate-age globular clusters in NGC4570 using K-band photometry

    NARCIS (Netherlands)

    Kotulla, R.; Fritze, U.; Anders, P.

    2009-01-01

    Globular cluster systems (GCSs) of most early-type galaxies feature two peaks in their optical colour distributions. Blue-peak globular clusters (GCs) are believed to be old and metal-poor, whereas the ages, metallicities, and the origin of the red-peak GCs are still being debated. We obtained deep

  10. Probing the ejecta of evolved massive stars in transition A VLT/SINFONI K-band survey

    Czech Academy of Sciences Publication Activity Database

    Oksala, Mary E.; Kraus, Michaela; Cidale, L.S.; Muratore, M.F.; Borges Fernandes, M.

    2013-01-01

    Roč. 558, October (2013), A17/1-A17/20 ISSN 0004-6361 R&D Projects: GA ČR(CZ) GAP209/11/1198; GA MŠk 7AMB12AR021 Institutional support: RVO:67985815 Keywords : infrared stars * spectroscopic techniques * massive stars Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.479, year: 2013

  11. Chemical evolution of fluorine in the bulge. High-resolution K-band spectra of giants in three fields

    Science.gov (United States)

    Jönsson, H.; Ryde, N.; Harper, G. M.; Cunha, K.; Schultheis, M.; Eriksson, K.; Kobayashi, C.; Smith, V. V.; Zoccali, M.

    2014-04-01

    Context. Possible main formation sites of fluorine in the Universe include asymptotic giant branch (AGB) stars, the ν-process in Type II supernova, and/or Wolf-Rayet stars. The importance of the Wolf-Rayet stars has theoretically been questioned and they are probably not needed in modeling the chemical evolution of fluorine in the solar neighborhood. It has, however, been suggested that Wolf-Rayet stars are indeed needed to explain the chemical evolution of fluorine in the bulge. The molecular spectral data, needed to determine the fluorine abundance, of the often used HF-molecule has not been presented in a complete and consistent way and has recently been debated in the literature. Aims: We intend to determine the trend of the fluorine-oxygen abundance ratio as a function of a metallicity indicator in the bulge to investigate the possible contribution from Wolf-Rayet stars. Additionally, we present here a consistent HF line list for the K- and L-bands including the often used 23 358.33 Å line. Methods: High-resolution near-infrared spectra of eight K giants were recorded using the spectrograph CRIRES mounted at the VLT. A standard setting was used that covered the HF molecular line at 23 358.33 Å. The fluorine abundances were determined using spectral fitting. We also re-analyzed five previously published bulge giants observed with the Phoenix spectrograph on Gemini using our new HF molecular data. Results: We find that the fluorine-oxygen abundance in the bulge probably cannot be explained with chemical evolution models that only include AGB stars and the ν-process in supernovae Type II, that is a significant amount of fluorine production in Wolf-Rayet stars is most likely needed to explain the fluorine abundance in the bulge. For the HF line data, we find that a possible reason for the inconsistencies in the literature, where two different excitation energies were used, is two different definitions of the zero-point energy for the HF molecule and therefore also two accompanying different dissociation energies. Both line lists are correct as long as the corresponding consistent partition function is used in the spectral synthesis. However, we suspect this has not been the case in several earlier works, which led to fluorine abundances ~0.3 dex too high. We present a line list for the K- and L-bands and an accompanying partition function. Based on observations collected at the European Southern Observatory, Chile (ESO programs 71.B-0617(A), 073.B0074(A), and 079.B-0338(A)) and observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), CNPq (Brazil), and CONICRT (Argentina), as program GS-2004A-Q-20.Figure 4 and Tables 5 and 6 are available in electronic form at http://www.aanda.org

  12. Uniformity measurement of wide area reference sources for beta emitters.

    Science.gov (United States)

    Ohshiro, Masahiro; Shiina, Takuya; Yamada, Takahiro

    2016-03-01

    When conducting uniformity measurements of a wide area reference source with a detector having a window of a size similar to that of a gridded individual portion area on the source, it is important to carefully consider neighbor effects on measuring emission rates of the individual target portion resulting from the gap between the source and detector window. Optimization of the uniformity measurement conditions was studied for beta-emitting wide area reference sources in this study. A measurement system consisting of a PR-gas (Ar: 90%+CH4: 10%) flow type windowed proportional counter and a motorized XY stage was installed. This system is adapted to the uniformity measurement of two different types of (36)Cl sources made by different manufacturers. Uniformity measurement of a 100mm×100mm source divided into 16 portions of 6.25cm(2) (25mm squared) each could be conducted using our system under the present conditions with a neighbor effect of around 15% or less. The measurement results by use of this system were also compared with those using the imaging plate technique. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Tracking small targets in wide area motion imagery data

    Science.gov (United States)

    Mathew, Alex; Asari, Vijayan K.

    2013-03-01

    Object tracking in aerial imagery is of immense interest to the wide area surveillance community. In this paper, we propose a method to track very small targets such as pedestrians in AFRL Columbus Large Image Format (CLIF) Wide Area Motion Imagery (WAMI) data. Extremely small target sizes, combined with low frame rates and significant view changes, make tracking a very challenging task in WAMI data. Two problems should be tackled for object tracking frame registration and feature extraction. We employ SURF for frame registration. Although there are several feature extraction methods that work reasonably well when the scene is of high resolution, most methods fail when the resolution is very low. In our approach, we represent the target as a collection of intensity histograms and use a robust statistical distance to distinguish between the target and the background. We divide the object into m ×n regions and compute the normalized intensity histogram in each region to build a histogram matrix. The features can be compared using the histogram comparison techniques. For tracking, we use a combination of a bearing-only Kalman filter and the proposed feature extraction technique. The problem of template drift is solved by further localizing the target with a blob detection algorithm. The new template is taken as the detected blob. We show the robustness of the algorithm by giving a comparison of feature extraction part of our method with other feature extraction methods like SURF, SIFT and HoG and tracking part with mean-shift tracking.

  14. Remote sensing education and Internet/World Wide Web technology

    Science.gov (United States)

    Griffith, J.A.; Egbert, S.L.

    2001-01-01

    Remote sensing education is increasingly in demand across academic and professional disciplines. Meanwhile, Internet technology and the World Wide Web (WWW) are being more frequently employed as teaching tools in remote sensing and other disciplines. The current wealth of information on the Internet and World Wide Web must be distilled, nonetheless, to be useful in remote sensing education. An extensive literature base is developing on the WWW as a tool in education and in teaching remote sensing. This literature reveals benefits and limitations of the WWW, and can guide its implementation. Among the most beneficial aspects of the Web are increased access to remote sensing expertise regardless of geographic location, increased access to current material, and access to extensive archives of satellite imagery and aerial photography. As with other teaching innovations, using the WWW/Internet may well mean more work, not less, for teachers, at least at the stage of early adoption. Also, information posted on Web sites is not always accurate. Development stages of this technology range from on-line posting of syllabi and lecture notes to on-line laboratory exercises and animated landscape flyovers and on-line image processing. The advantages of WWW/Internet technology may likely outweigh the costs of implementing it as a teaching tool.

  15. Wide-Field Slitless Spectroscopy with JWST/NIRISS

    Science.gov (United States)

    Dixon, William V.

    2013-01-01

    The Near Infrared Imager and Slitless Spectrograph (NIRISS) is one of four scientific instruments that will fly aboard the James Webb Space Telescope (JWST) later in this decade. Among its capabilities, NIRISS offers wide-field slitless spectroscopy (WFSS) with a resolving power R = 150 over the wavelength range 1.0 to 2.25 microns using a pair of grisms that disperse light in orthogonal directions. Employing the software packages aXe and Source Extractor, we have developed the configuration files needed to model WFSS observations with NIRISS and to extract and calibrate the resulting spectra. These files, together with a cookbook detailing their use, are available on the JWST/NIRISS web site at STScI. Using these tools, we construct synthetic images of the near-IR sky, identify and extract the spectra of individual sources, and demonstrate that NIRISS can observe galaxies with redshifts up to z = 17. NIRISS is provided to the JWST project by the Canadian Space Agency under the leadership of René Doyon of the Université de Montréal. The prime contractor is COM DEV Canada.

  16. Development of Autonomous Magnetometer Rotorcraft For Wide Area Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Mark D. McKay; Matthew O. Anderson

    2011-08-01

    Large areas across the United States and internationally are potentially contaminated with unexploded ordinance (UXO), with some ranges encompassing tens to hundreds of thousands of acres. Technologies are needed which will allow for cost effective wide area scanning with (1) near 100% coverage and (2) near 100% detection of subsurface ordnance or features indicative of subsurface ordnance. The current approach to wide area assessment is a multi-level one, in which medium - altitude fixed wing optical imaging is used for an initial site assessment. This assessment is followed with low altitude manned helicopter based magnetometry. Subsequent to this wide area assessment targeted surface investigations are performed using either towed geophysical sensor arrays or man portable sensors. In order to be an effective tool for small UXO detection, the sensing altitude for magnetic site investigations needs to be on the order of 1 to 3 meters. These altitude requirements mean that manned helicopter surveys will generally only be feasible in large, open and relatively flat terrains. While such surveys are effective in mapping large areas relatively fast there are substantial mobilization/demobilization, staffing and equipment costs associated with these surveys, resulting in costs of approximately $100-$150/acre. In addition, due to the low altitude there are substantial risks to pilots and equipment. Surface towed arrays provide highresolution maps but have other limitations, e.g. in their ability to navigate rough terrain effectively. Thus there is a need for other systems, which can be used for effective data collection. An Unmanned Aerial Vehicle (UAV) magnetometer platform is an obvious alternative. The motivation behind such a system is that it reduces risk to operators, is lower in initial and Operational and Maintenance (O&M) costs (and can thus potentially be applied to smaller sites) and has the potential of being more effective in terms of detection and possibly

  17. Acoustical Imaging

    CERN Document Server

    Litniewski, Jerzy; Kujawska, Tamara; 31st International Symposium on Acoustical Imaging

    2012-01-01

    The International Symposium on Acoustical Imaging is a unique forum for advanced research, covering new technologies, developments, methods and theories in all areas of acoustics. This interdisciplinary Symposium has been taking place continuously since 1968. In the course of the years the proceedings volumes in the Acoustical Imaging Series have become a reference for cutting-edge research in the field. In 2011 the 31st International Symposium on Acoustical Imaging was held in Warsaw, Poland, April 10-13. Offering both a broad perspective on the state-of-the-art as well as  in-depth research contributions by the specialists in the field, this Volume 31 in the Series contains an excellent collection of papers in six major categories: Biological and Medical Imaging Physics and Mathematics of Acoustical Imaging Acoustic Microscopy Transducers and Arrays Nondestructive Evaluation and Industrial Applications Underwater Imaging

  18. Image Inpainting

    Science.gov (United States)

    2005-01-01

    Image Inpainting Marcelo Bertalmio and Guillermo Sapiro Electrical and Computer Engineering, University of Minnesota Vicent Caselles and Coloma...Ballester Escola Superior Politecnica, Universitat Pompeu Fabra Abstract Inpainting , the technique of modifying an image in an undetectable form, is as...removal/replacement of selected objects. In this paper, we introduce a novel algorithm for digital inpainting of still images that attempts to replicate the

  19. {beta} - amyloid imaging probes

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jae Min [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2007-04-15

    Imaging distribution of {beta} - amyloid plaques in Alzheimer's disease is very important for early and accurate diagnosis. Early trial of the {beta} -amyloid plaques includes using radiolabeled peptides which can be only applied for peripheral {beta} - amyloid plaques due to limited penetration through the blood brain barrier (BBB). Congo red or Chrysamine G derivatives were labeled with Tc-99m for imaging {beta} - amyloid plaques of Alzheimer patient's brain without success due to problem with BBB penetration. Thioflavin T derivatives gave breakthrough for {beta} - amyloid imaging in vivo, and a benzothiazole derivative [C-11]6-OH-BTA-1 brought a great success. Many other benzothiazole, benzoxazole, benzofuran, imidazopyridine, and styrylbenzene derivatives have been labeled with F-18 and I-123 to improve the imaging quality. However, [C-11]6-OH-BTA-1 still remains as the best. However, short half-life of C-11 is a limitation of wide distribution of this agent. So, it is still required to develop an Tc-99m, F-18 or I-123 labeled agent for {beta} - amyloid imaging agent.

  20. Magnetic Resonance Imaging and Spectroscopy in Cancer Theranostic Imaging.

    Science.gov (United States)

    Penet, Marie-France; Jin, Jiefu; Chen, Zhihang; Bhujwalla, Zaver M

    2016-10-01

    With its exquisite anatomical resolution and wide-ranging functional imaging capabilities, magnetic resonance imaging (MRI) has found multiple applications in detection, staging, and monitoring treatment response in cancer. The metabolic information provided by magnetic resonance spectroscopy (MRS) is being actively investigated to complement MRI parameters, as well as existing biomarkers, in cancer detection and in monitoring response to treatment. Located at the interface of detection and therapy, theranostic imaging is a rapidly expanding new field that is showing significant promise for precision medicine of cancer. Innovations in the development of novel nanoparticles decorated with imaging reporters that can be used to deliver therapeutic cargo to specific cells and environments have provided new roles for MRI and MRS in theranostic imaging.

  1. Imaging spectroscopy for scene analysis

    CERN Document Server

    Robles-Kelly, Antonio

    2012-01-01

    This book presents a detailed analysis of spectral imaging, describing how it can be used for the purposes of material identification, object recognition and scene understanding. The opportunities and challenges of combining spatial and spectral information are explored in depth, as are a wide range of applications. Features: discusses spectral image acquisition by hyperspectral cameras, and the process of spectral image formation; examines models of surface reflectance, the recovery of photometric invariants, and the estimation of the illuminant power spectrum from spectral imagery; describes

  2. WIRELESS MINE-WIDE TELECOMMUNICATIONS TECHNOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    Zvi H. Meiksin

    2004-03-01

    A comprehensive mine-wide, two-way wireless voice and data communication system for the underground mining industry was developed. The system achieves energy savings through increased productivity and greater energy efficiency in meeting safety requirements within mines. The mine-wide system is comprised of two interfaced subsystems: a through-the-earth communications system and an in-mine communications system. The mine-wide system permits two-way communication among underground personnel and between underground and surface personnel. The system was designed, built, and commercialized. Several systems are in operation in underground mines in the United States. The use of these systems has proven they result in considerable energy savings. A system for tracking the location of vehicles and people within the mine was also developed, built and tested successfully. Transtek's systems are being used by the National Institute of Occupational Safety and Health (NIOSH) in their underground mine rescue team training program. This project also resulted in a spin-off rescue team lifeline and communications system. Furthermore, the project points the way to further developments that can lead to a GPS-like system for underground mines allowing the use of autonomous machines in underground mining operations, greatly reducing the amount of energy used in these operations. Some products developed under this program are transferable to applications in fields other than mining. The rescue team system is applicable to use by first responders to natural, accidental, or terrorist-caused building collapses. The in-mine communications system can be installed in high-rise buildings providing in-building communications to security and maintenance personnel as well as to first responders.

  3. Intermediate Images

    Directory of Open Access Journals (Sweden)

    Paech Joachim

    2014-12-01

    Full Text Available Starting from a definition of the word ‘picture’ as a real-world object that shows other objects on its surface as a representation of its image, I propose that the intermediality of pictures of all kinds is only possible through their images, after they have been separated from their material basis or foundation (for example, a painting in its physical reality can never be directly connected with a movie. In all technical reproductions of images, such as printing processes, an image is taken from a negative matrix in order to realize multiple prints of the same representation. The most effective model of this procedure is photography: photographic images can easily be connected with their media forms to produce other, more complex forms, such as magazines, printed books, or films. Intermediate images in the form of matrices - sometimes transparent (e.g. in the light beam of a film projection, sometimes opaque - are required to transform one pictorial media form into another. Finally, for the digital matrix-image, there is no longer any difference between the matrix and the image: the matrix has become its own image, which can be linked to all other media forms.

  4. Promoting and supporting PBL interests world wide

    DEFF Research Database (Denmark)

    Enemark, Stig; Kolmos, Anette; Moesby, Egon

    2006-01-01

    of projects world wide focusing on institutional change toward a more student centred, project organised, and problem based approach to learning. The Centre is also establishing a UCPBL Global Network on Problem Based Learning in order to facilitate better access to and co-operation within the PBL area.......-Based Learning (PBL) in Engineering Education, an increasing number of universities and engineering schools throughout the world are seeking consultancy and cooperation with Aalborg University. The establishment of UCPBL is therefore a timely opportunity to merge the efforts into one organisational structure...

  5. Image processing for cameras with fiber bundle image relay.

    Science.gov (United States)

    Olivas, Stephen J; Arianpour, Ashkan; Stamenov, Igor; Morrison, Rick; Stack, Ron A; Johnson, Adam R; Agurok, Ilya P; Ford, Joseph E

    2015-02-10

    Some high-performance imaging systems generate a curved focal surface and so are incompatible with focal plane arrays fabricated by conventional silicon processing. One example is a monocentric lens, which forms a wide field-of-view high-resolution spherical image with a radius equal to the focal length. Optical fiber bundles have been used to couple between this focal surface and planar image sensors. However, such fiber-coupled imaging systems suffer from artifacts due to image sampling and incoherent light transfer by the fiber bundle as well as resampling by the focal plane, resulting in a fixed obscuration pattern. Here, we describe digital image processing techniques to improve image quality in a compact 126° field-of-view, 30 megapixel panoramic imager, where a 12 mm focal length F/1.35 lens made of concentric glass surfaces forms a spherical image surface, which is fiber-coupled to six discrete CMOS focal planes. We characterize the locally space-variant system impulse response at various stages: monocentric lens image formation onto the 2.5 μm pitch fiber bundle, image transfer by the fiber bundle, and sensing by a 1.75 μm pitch backside illuminated color focal plane. We demonstrate methods to mitigate moiré artifacts and local obscuration, correct for sphere to plane mapping distortion and vignetting, and stitch together the image data from discrete sensors into a single panorama. We compare processed images from the prototype to those taken with a 10× larger commercial camera with comparable field-of-view and light collection.

  6. Multiscale image contrast amplification (MUSICA)

    Science.gov (United States)

    Vuylsteke, Pieter; Schoeters, Emile P.

    1994-05-01

    This article presents a novel approach to the problem of detail contrast enhancement, based on multiresolution representation of the original image. The image is decomposed into a weighted sum of smooth, localized, 2D basis functions at multiple scales. Each transform coefficient represents the amount of local detail at some specific scale and at a specific position in the image. Detail contrast is enhanced by non-linear amplification of the transform coefficients. An inverse transform is then applied to the modified coefficients. This yields a uniformly contrast- enhanced image without artefacts. The MUSICA-algorithm is being applied routinely to computed radiography images of chest, skull, spine, shoulder, pelvis, extremities, and abdomen examinations, with excellent acceptance. It is useful for a wide range of applications in the medical, graphical, and industrial area.

  7. Live cell imaging of mechanotransduction

    OpenAIRE

    Liu, Bo; Kim, Tae-Jin; Wang, Yingxiao

    2010-01-01

    Mechanical forces play important roles in the regulation of cellular functions, including polarization, migration and stem cell differentiation. Tremendous advancement in our understanding of mechanotransduction has been achieved with the recent development of imaging technologies and molecular biosensors. In particular, genetically encoded biosensors based on fluorescence resonance energy transfer (FRET) technology have been widely developed and applied in the field of mechanobiology. In thi...

  8. Neuroperformance Imaging

    Science.gov (United States)

    2014-10-01

    the descent into sleep and are altered by sleep deprivation; 3) EEG /fMRI studies designed to improve our understanding of the interaction between sleep ... studies clearly indicate changes in resting state brain network connectivity in the transition from alert wakefulness to sleep . 15. SUBJECT TERMS...Neuroperformance, Sleep cycle, metabolism, thalamic structures, PET Imaging, MR Imaging, functional MRI, electroencephalography ( EEG ) 16. SECURITY

  9. Star Imager

    DEFF Research Database (Denmark)

    Madsen, Peter Buch; Jørgensen, John Leif; Thuesen, Gøsta

    1997-01-01

    The version of the star imager developed for Astrid II is described. All functions and features are described as well as the operations and the software protocol.......The version of the star imager developed for Astrid II is described. All functions and features are described as well as the operations and the software protocol....

  10. Incompatible Images

    DEFF Research Database (Denmark)

    Sassene, Michel J.; Hertzum, Morten

    2008-01-01

    is, however, based on a taken-for-granted image of asthmatics as, per se, striving to be symptom-free. This image is incompatible with interviewed asthmatics' day-to-day performances of their asthma, and renders invisible (a) that their asthma performances emphasize an economy of good passages...

  11. Blurred Image

    Science.gov (United States)

    Conde, Maryse

    1975-01-01

    The growing influence of Western culture has greatly affected African women's status and image in the traditional society. Working women are confronted with the dilemma of preserving family traditions while changing their behavior and image to become members of the labor force. (MR)

  12. Imaging Genetics

    Science.gov (United States)

    Munoz, Karen E.; Hyde, Luke W.; Hariri, Ahmad R.

    2009-01-01

    Imaging genetics is an experimental strategy that integrates molecular genetics and neuroimaging technology to examine biological mechanisms that mediate differences in behavior and the risks for psychiatric disorder. The basic principles in imaging genetics and the development of the field are discussed.

  13. Digital image correlation in experimental mechanics and image registration in computer vision: Similarities, differences and complements

    Science.gov (United States)

    Wang, Zhaoyang; Kieu, Hien; Nguyen, Hieu; Le, Minh

    2015-02-01

    Digital image correlation and image registration or matching are among the most widely used techniques in the fields of experimental mechanics and computer vision, respectively. Despite their applications in separate fields, both techniques primarily involve detecting the same physical points in two or more images. In this paper, a brief technical comparison of the two techniques is reviewed, and their similarities and differences as well as complements are presented. It is shown that some concepts from the image registration or matching technique can be applied to the digital image correlation technique to substantially enhance its performance, which can help broaden the applications of digital image correlation in scientific research and engineering practice.

  14. Acoustical Imaging

    CERN Document Server

    Akiyama, Iwaki

    2009-01-01

    The 29th International Symposium on Acoustical Imaging was held in Shonan Village, Kanagawa, Japan, April 15-18, 2007. This interdisciplinary Symposium has been taking place every two years since 1968 and forms a unique forum for advanced research, covering new technologies, developments, methods and theories in all areas of acoustics. In the course of the years the volumes in the Acoustical Imaging Series have developed and become well-known and appreciated reference works. Offering both a broad perspective on the state-of-the-art in the field as well as an in-depth look at its leading edge research, this Volume 29 in the Series contains again an excellent collection of seventy papers presented in nine major categories: Strain Imaging Biological and Medical Applications Acoustic Microscopy Non-Destructive Evaluation and Industrial Applications Components and Systems Geophysics and Underwater Imaging Physics and Mathematics Medical Image Analysis FDTD method and Other Numerical Simulations Audience Researcher...

  15. Research on image registration based on D-Nets

    Science.gov (United States)

    Wu, Cengceng; Liu, Zhaoguang; Cheng, Hongtan

    2017-06-01

    Image registration is the key technology of digital imaging applications, it is used widely. We researched the image registration techniques in this paper. Based on the basis of D-Nets image registration algorithms, we propose a new innovation. We turn first to process image, so we can get synthetic images of original images and enhanced images. Then we extract SIFT feature in the original image. Next, in order to reduce noise of the image, we use the Gauss filter to process the synthesized image. Then we do experiments with synthetic images in the process of image registration. In this process, we use the D-Nets algorithm to achieve. Compared to the existing method, it can greatly improve the accuracy and recall.

  16. Retinal image analysis: preprocessing and feature extraction

    Energy Technology Data Exchange (ETDEWEB)

    Marrugo, Andres G; Millan, Maria S, E-mail: andres.marrugo@upc.edu [Grup d' Optica Aplicada i Processament d' Imatge, Departament d' Optica i Optometria Univesitat Politecnica de Catalunya (Spain)

    2011-01-01

    Image processing, analysis and computer vision techniques are found today in all fields of medical science. These techniques are especially relevant to modern ophthalmology, a field heavily dependent on visual data. Retinal images are widely used for diagnostic purposes by ophthalmologists. However, these images often need visual enhancement prior to apply a digital analysis for pathological risk or damage detection. In this work we propose the use of an image enhancement technique for the compensation of non-uniform contrast and luminosity distribution in retinal images. We also explore optic nerve head segmentation by means of color mathematical morphology and the use of active contours.

  17. Hologram production and representation for corrected image

    Science.gov (United States)

    Jiao, Gui Chao; Zhang, Rui; Su, Xue Mei

    2015-12-01

    In this paper, a CCD sensor device is used to record the distorted homemade grid images which are taken by a wide angle camera. The distorted images are corrected by using methods of position calibration and correction of gray with vc++ 6.0 and opencv software. Holography graphes for the corrected pictures are produced. The clearly reproduced images are obtained where Fresnel algorithm is used in graph processing by reducing the object and reference light from Fresnel diffraction to delete zero-order part of the reproduced images. The investigation is useful in optical information processing and image encryption transmission.

  18. Terahertz Imaging Systems With Aperture Synthesis Techniques

    DEFF Research Database (Denmark)

    Krozer, Viktor; Löffler, Torsten; Dall, Jørgen

    2010-01-01

    in this paper. An active system operation allows for a wide dynamic range, which is important for image quality. The described instruments employ a multichannel high-sensitivity heterodyne architecture and aperture filling techniques, with close to real-time image acquisition time. In the case of the photonic...... imaging system, mechanical scanning is completely obsolete. We show 2-D images of simulated 3-D image data for both systems. The reconstruction algorithms are suitable for 3-D real-time operation, only limited by mechanical scanning....

  19. Still Persistent Global Problem of Scientists' Image

    Science.gov (United States)

    Türkmen, Hakan

    2015-01-01

    Pre-service teachers' views of science and scientists have been widely studied. The purpose of this study is to identify whether there is problem of image of scientists and determine where they receive about scientist image. Three hundred thirty five (105 from Turkey, 162 from Europe, 68 from US) elementary pre-service teachers participated in…

  20. Toward wide-angle microvision sensors.

    Science.gov (United States)

    Koppal, Sanjeev J; Gkioulekas, Ioannis; Young, Travis; Park, Hyunsung; Crozier, Kenneth B; Barrows, Geoffrey L; Zickler, Todd

    2013-12-01

    Achieving computer vision on microscale devices is a challenge. On these platforms, the power and mass constraints are severe enough for even the most common computations (matrix manipulations, convolution, etc.) to be difficult. This paper proposes and analyzes a class of miniature vision sensors that can help overcome these constraints. These sensors reduce power requirements through template-based optical convolution, and they enable a wide field-of-view within a small form through a refractive optical design. We describe the tradeoffs between the field-of-view, volume, and mass of these sensors and we provide analytic tools to navigate the design space. We demonstrate milliscale prototypes for computer vision tasks such as locating edges, tracking targets, and detecting faces. Finally, we utilize photolithographic fabrication tools to further miniaturize the optical designs and demonstrate fiducial detection onboard a small autonomous air vehicle.

  1. Genome-Wide Association Studies of Cancer

    Science.gov (United States)

    Stadler, Zsofia K.; Thom, Peter; Robson, Mark E.; Weitzel, Jeffrey N.; Kauff, Noah D.; Hurley, Karen E.; Devlin, Vincent; Gold, Bert; Klein, Robert J.; Offit, Kenneth

    2010-01-01

    Knowledge of the inherited risk for cancer is an important component of preventive oncology. In addition to well-established syndromes of cancer predisposition, much remains to be discovered about the genetic variation underlying susceptibility to common malignancies. Increased knowledge about the human genome and advances in genotyping technology have made possible genome-wide association studies (GWAS) of human diseases. These studies have identified many important regions of genetic variation associated with an increased risk for human traits and diseases including cancer. Understanding the principles, major findings, and limitations of GWAS is becoming increasingly important for oncologists as dissemination of genomic risk tests directly to consumers is already occurring through commercial companies. GWAS have contributed to our understanding of the genetic basis of cancer and will shed light on biologic pathways and possible new strategies for targeted prevention. To date, however, the clinical utility of GWAS-derived risk markers remains limited. PMID:20585100

  2. [Wide QRS tachycardia preceded by pacemaker spikes].

    Science.gov (United States)

    Romero, M; Aranda, A; Gómez, F J; Jurado, A

    2014-04-01

    The differential diagnosis and therapeutic management of wide QRS tachycardia preceded by pacemaker spike is presented. The pacemaker-mediated tachycardia, tachycardia fibrillo-flutter in patients with pacemakers, and runaway pacemakers, have a similar surface electrocardiogram, but respond to different therapeutic measures. The tachycardia response to the application of a magnet over the pacemaker could help in the differential diagnosis, and in some cases will be therapeutic, as in the case of a tachycardia-mediated pacemaker. Although these conditions are diagnosed and treated in hospitals with catheterization laboratories using the application programmer over the pacemaker, patients presenting in primary care clinic and emergency forced us to make a diagnosis and treat the haemodynamically unstable patient prior to referral. Copyright © 2012 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España. All rights reserved.

  3. World Wide Web Metasearch Clustering Algorithm

    Directory of Open Access Journals (Sweden)

    Adina LIPAI

    2008-01-01

    Full Text Available As the storage capacity and the processing speed of search engine is growing to keep up with the constant expansion of the World Wide Web, the user is facing an increasing list of results for a given query. A simple query composed of common words sometimes have hundreds even thousands of results making it practically impossible for the user to verify all of them, in order to identify a particular site. Even when the list of results is presented to the user ordered by a rank, most of the time it is not sufficient support to help him identify the most relevant sites for his query. The concept of search result clustering was introduced as a solution to this situation. The process of clustering search results consists of building up thematically homogenous groups from the initial list results provided by classic search tools, and using up characteristics present within the initial results, without any kind of predefined categories.

  4. World-Wide Web the information universe

    CERN Document Server

    Berners-Lee, Tim; Groff, Jean-Francois; Pollermann, Bernd

    1992-01-01

    Purpose - The World-Wide Web (W-3) initiative is a practical project designed to bring a global information universe into existence using available technology. This paper seeks to describe the aims, data model, and protocols needed to implement the "web" and to compare them with various contemporary systems. Design/methodology/approach - Since Vannevar Bush's article, men have dreamed of extending their intellect by making their collective knowledge available to each individual by using machines. Computers provide us two practical techniques for human-knowledge interface. One is hypertext, in which links between pieces of text (or other media) mimic human association of ideas. The other is text retrieval, which allows associations to be deduced from the content of text. The W-3 ideal world allows both operations and provides access from any browsing platform. Findings - Various server gateways to other information systems have been produced, and the total amount of information available on the web is...

  5. Teacher Reviews of Widely Used Physics Textbooks

    Science.gov (United States)

    2011-05-01

    Holt Physics (Serway & Faughn), Physics Principles and Problems (Zitzewitz), Conceptual Physics (Hewitt), and Physics: Principles with Applications (Giancoli) were the most widely used textbooks for regular high school physics courses during the 2008-09 academic year. Holt Physics and Zitzewitz were each used by about one-third of the teachers responding to our Nationwide Survey of High School Physics Teachers. Hewitt's text was used by approximately one-fourth of the teachers who responded, and 6% of the respondents reported using Giancoli. We also asked the respondents to tell us how well the text worked for the course. The good news is that well over 80% of the teachers find that all four of these texts work quite well or somewhat well for teaching regular physics.

  6. Wide-Stopband Aperiodic Phononic Filters

    Science.gov (United States)

    Rostem, Karwan; Chuss, David; Denis, K. L.; Wollack, E. J.

    2016-01-01

    We demonstrate that a phonon stopband can be synthesized from an aperiodic structure comprising a discrete set of phononic filter stages. Each element of the set has a dispersion relation that defines a complete bandgap when calculated under a Bloch boundary condition. Hence, the effective stopband width in an aperiodic phononic filter (PnF) may readily exceed that of a phononic crystal with a single lattice constant or a coherence scale. With simulations of multi-moded phononic waveguides, we discuss the effects of finite geometry and mode-converting junctions on the phonon transmission in PnFs. The principles described may be utilized to form a wide stopband in acoustic and surface wave media. Relative to the quantum of thermal conductance for a uniform mesoscopic beam, a PnF with a stopband covering 1.6-10.4 GHz is estimated to reduce the thermal conductance by an order of magnitude at 75 mK.

  7. Plant Wide Assessment for SIFCO Industries, Inc.

    Energy Technology Data Exchange (ETDEWEB)

    Kelly Kissock, Arvind Thekdi et. al.

    2005-07-06

    Sifco Industries carreid out a plant wide energy assessment under a collaborative program with the U.S. Department of Energy during October 2004 to September 2005. During the year, personnel from EIS, E3M, DPS, BuyCastings.Com, and Sifco plant facilities and maintenance personnel, as a team collected energy use, construction, process, equipment and operational information about the plant. Based on this information, the team identified 13 energy savings opportunities. Near term savings opportunities have a total potential savings of about $1,329,000 per year and a combined simple payback of about 11 months. Implementation of these recommendations would reduce CO2 emissions by about 16,000,000 pounds per year, which would reduce overall plant CO2 emissions by about 45%. These totals do not include another $830,000 per year in potential savings with an estimated 9-month payback, from converting the forging hammers from steam to compressed air.

  8. Fundus imaging with a nasal endoscope

    Directory of Open Access Journals (Sweden)

    P Mahesh Shanmugam

    2015-01-01

    Full Text Available Wide field fundus imaging is needed to diagnose, treat, and follow-up patients with retinal pathology. This is more applicable for pediatric patients as repeated evaluation is a challenge. The presently available imaging machines though provide high definition images, but carry the obvious disadvantages of either being costly or bulky or sometimes both, which limits its usage only to large centers. We hereby report a technique of fundus imaging using a nasal endoscope coupled with viscoelastic. A regular nasal endoscope with viscoelastic coupling was placed on the cornea to image the fundus of infants under general anesthesia. Wide angle fundus images of various fundus pathologies in infants could be obtained easily with readily available instruments and without the much financial investment for the institutes.

  9. Micromachined Ultrasonic Transducers for 3-D Imaging

    DEFF Research Database (Denmark)

    Christiansen, Thomas Lehrmann

    Real-time ultrasound imaging is a widely used technique in medical diagnostics. Recently, ultrasound systems offering real-time imaging in 3-D has emerged. However, the high complexity of the transducer probes and the considerable increase in data to be processed compared to conventional 2-D...... techniques, a complete hand-held 3MHz λ/2-pitch ultrasound probe for volumetric imaging with 62+62 elements and in-handle electronics is produced and used on a commercial bk3000 scanner from BK Medical. The scanner is made for conventional 2-D ultrasound imaging, proving that the developed technology enables...... ultrasound imaging results in expensive systems, which limits the more wide-spread use and clinical development of volumetric ultrasound. The main goal of this thesis is to demonstrate new transducer technologies that can achieve real-time volumetric ultrasound imaging without the complexity and cost...

  10. Magnetopause reconnection across wide local time

    Directory of Open Access Journals (Sweden)

    M. W. Dunlop

    2011-09-01

    Full Text Available During April to July 2007 a combination of 10 spacecraft provided simultaneous monitoring of the dayside magnetopause across a wide range of local times. The array of four Cluster spacecraft, separated at large distances (10 000 km, were traversing the dawn-side magnetopause at high and low latitudes; the five THEMIS spacecraft were often in a 4 + 1 grouped configuration, traversing the low latitude, dusk-side magnetosphere, and the Double star, TC-1 spacecraft was in an equatorial orbit between the local times of the THEMIS and Cluster orbits. We show here a number of near simultaneous conjunctions of all 10 spacecraft at the magnetopause. One conjunction identifies an extended magnetic reconnection X-line, tilted in the low latitude, sub-solar region, which exists together with active anti-parallel reconnection sites extending to locations on the dawn-side flank. Oppositely moving FTE's are observed on all spacecraft, consistent with the initially strong IMF By conditions and the comparative locations of the spacecraft both dusk-ward and dawn-ward of noon. Comparison with other conjunctions of magnetopause crossings, which are also distributed over wide local times, supports the result that reconnection activity may occur at many sites simultaneously across the sub-solar and flank magnetopause, but linked to the large scale (extended configuration of the merging line; broadly depending on IMF orientation. The occurrence of MR therefore inherently follows a "component" driven scenario irrespective of the guide field conditions. Some conjunctions allow the global magnetopause response to IMF changes to be observed and the distribution of spacecraft can directly confirm its shape, motion and deformation at local noon, dawn and dusk-side, simultaneously.

  11. Magnetopause reconnection across wide local time

    Directory of Open Access Journals (Sweden)

    M. W. Dunlop

    2011-09-01

    Full Text Available During April to July 2007 a combination of 10 spacecraft provided simultaneous monitoring of the dayside magnetopause across a wide range of local times. The array of four Cluster spacecraft, separated at large distances (10 000 km, were traversing the dawn-side magnetopause at high and low latitudes; the five THEMIS spacecraft were often in a 4 + 1 grouped configuration, traversing the low latitude, dusk-side magnetosphere, and the Double star, TC-1 spacecraft was in an equatorial orbit between the local times of the THEMIS and Cluster orbits. We show here a number of near simultaneous conjunctions of all 10 spacecraft at the magnetopause. One conjunction identifies an extended magnetic reconnection X-line, tilted in the low latitude, sub-solar region, which exists together with active anti-parallel reconnection sites extending to locations on the dawn-side flank. Oppositely moving FTE's are observed on all spacecraft, consistent with the initially strong IMF By conditions and the comparative locations of the spacecraft both dusk-ward and dawn-ward of noon. Comparison with other conjunctions of magnetopause crossings, which are also distributed over wide local times, supports the result that reconnection activity may occur at many sites simultaneously across the sub-solar and flank magnetopause, but linked to the large scale (extended configuration of the merging line; broadly depending on IMF orientation. The occurrence of MR therefore inherently follows a "component" driven scenario irrespective of the guide field conditions. Some conjunctions allow the global magnetopause response to IMF changes to be observed and the distribution of spacecraft can directly confirm its shape, motion and deformation at local noon, dawn and dusk-side, simultaneously.

  12. Planet-wide sand motion on mars

    Science.gov (United States)

    Bridges, N.T.; Bourke, M.C.; Geissler, P.E.; Banks, M.E.; Colon, C.; Diniega, S.; Golombek, M.P.; Hansen, C.J.; Mattson, S.; McEwen, A.S.; Mellon, M.T.; Stantzos, N.; Thomson, B.J.

    2012-01-01

    Prior to Mars Reconnaissance Orbiter data, images of Mars showed no direct evidence for dune and ripple motion. This was consistent with climate models and lander measurements indicating that winds of sufficient intensity to mobilize sand were rare in the low-density atmosphere. We show that many sand ripples and dunes across Mars exhibit movement of as much as a few meters per year, demonstrating that Martian sand migrates under current conditions in diverse areas of the planet. Most motion is probably driven by wind gusts that are not resolved in global circulation models. A past climate with a thicker atmosphere is only required to move large ripples that contain coarse grains. ?? 2012 Geological Society of America.

  13. COLOR IMAGES

    Directory of Open Access Journals (Sweden)

    Dominique Lafon

    2011-05-01

    Full Text Available The goal of this article is to present specific capabilities and limitations of the use of color digital images in a characterization process. The whole process is investigated, from the acquisition of digital color images to the analysis of the information relevant to various applications in the field of material characterization. A digital color image can be considered as a matrix of pixels with values expressed in a vector-space (commonly 3 dimensional space whose specificity, compared to grey-scale images, is to ensure a coding and a representation of the output image (visualisation printing that fits the human visual reality. In a characterization process, it is interesting to regard color image attnbutes as a set of visual aspect measurements on a material surface. Color measurement systems (spectrocolorimeters, colorimeters and radiometers and cameras use the same type of light detectors: most of them use Charge Coupled Devices sensors. The difference between the two types of color data acquisition systems is that color measurement systems provide a global information of the observed surface (average aspect of the surface: the color texture is not taken into account. Thus, it seems interesting to use imaging systems as measuring instruments for the quantitative characterization of the color texture.

  14. Image compression for medical diagnosis using neural networks

    OpenAIRE

    Lanzarini, Laura Cristina; Vargas Camacho, María Teresa; Flores Badrán, Amado; De Giusti, Armando Eduardo

    2000-01-01

    Images compression is a widely studied topic. Conventional situations offer variable compression ratios depending on the image in question and, in general, do not yield good results for images that are rich in tones. This work is an application of images compression of patient s computed tomographies using neural networks, which allows to carry out both compression and decompression of the images with a fixed ratio of 8:1 and a loss of 2%. Facultad de Informática

  15. Color Image Segmentation Using Fuzzy C-Regression Model

    OpenAIRE

    Min Chen; Ludwig, Simone A.

    2017-01-01

    Image segmentation is one important process in image analysis and computer vision and is a valuable tool that can be applied in fields of image processing, health care, remote sensing, and traffic image detection. Given the lack of prior knowledge of the ground truth, unsupervised learning techniques like clustering have been largely adopted. Fuzzy clustering has been widely studied and successfully applied in image segmentation. In situations such as limited spatial resolution, poor contrast...

  16. Generalized image deconvolution by exploiting spatially variant point spread functions

    OpenAIRE

    Lee, Sangyun; Lee, KyeoReh; Shin, Seungwoo; Park, YongKeun

    2017-01-01

    An optical imaging system forms an object image by recollecting light scattered by the object. However, intact optical information of the object delivered through the imaging system is deteriorated by imperfect optical elements and unwanted defects. Image deconvolution, also known as inverse filtering, has been widely exploited as a recovery technique because of its practical feasibility, and operates by assuming the linear shift-invariant property of the imaging system. However, shift invari...

  17. IMAGE RETRIEVAL: A STATE OF THE ART APPROACH FOR CBIR

    OpenAIRE

    AMANDEEP KHOKHER; DR. RAJNEESH TALWAR

    2011-01-01

    The emergence of multimedia, the availability of large image archives, and the rapid growth of the World Wide Web Web (WWW) have attracted significant research efforts in providing tools for effective retrieval and management of visual data. A major approach directed towards achieving this goal is to use visual contents ofthe image data to segment, index and retrieve relevant images from the image database. The commonest approaches use the so-called Content-Based Image Retrieval (CBIR) system...

  18. Color Image Quality in Presentation Software

    Directory of Open Access Journals (Sweden)

    Edison Valencia

    2008-01-01

    Full Text Available The color image quality of presentation programs is evaluated and measured using S-CIELAB and CIEDE2000 color difference formulae. A color digital image in its original format is compared with the same image already imported by the program and introduced as a part of a slide. Two widely used presentation programs—Microsoft PowerPoint 2004 for Mac and Apple's Keynote 3.0.2—are evaluated in this work.

  19. Handheld microwave bomb-detecting imaging system

    Science.gov (United States)

    Gorwara, Ashok; Molchanov, Pavlo

    2017-05-01

    Proposed novel imaging technique will provide all weather high-resolution imaging and recognition capability for RF/Microwave signals with good penetration through highly scattered media: fog, snow, dust, smoke, even foliage, camouflage, walls and ground. Image resolution in proposed imaging system is not limited by diffraction and will be determined by processor and sampling frequency. Proposed imaging system can simultaneously cover wide field of view, detect multiple targets and can be multi-frequency, multi-function. Directional antennas in imaging system can be close positioned and installed in cell phone size handheld device, on small aircraft or distributed around protected border or object. Non-scanning monopulse system allows dramatically decrease in transmitting power and at the same time provides increased imaging range by integrating 2-3 orders more signals than regular scanning imaging systems.

  20. SEEDS ADAPTIVE OPTICS IMAGING OF THE ASYMMETRIC TRANSITION DISK OPH IRS 48 IN SCATTERED LIGHT

    Energy Technology Data Exchange (ETDEWEB)

    Follette, Katherine B.; Close, Laird M. [Steward Observatory, The University of Arizona, 933 N. Cherry Ave., Tucson, AZ 85721 (United States); Grady, Carol A. [Eureka Scientific, 2452 Delmer, Suite 100, Oakland, CA 96002 (United States); Swearingen, Jeremy R.; Sitko, Michael L.; Champney, Elizabeth H. [Department of Physics, University of Cincinnati, Cincinnati, OH 45221 (United States); Van der Marel, Nienke; Maaskant, Koen; Min, Michiel [Leiden Observatory, Leiden University, P.O. Box 9513, 2300-RA Leiden (Netherlands); Takami, Michihiro [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 106, Taiwan (China); Kuchner, Marc J; McElwain, Michael W. [NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics Laboratory, Code 667, Greenbelt, MD 20771 (United States); Muto, Takayuki [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo 152-8551 (Japan); Mayama, Satoshi [The Graduate University for Advanced Studies (SOKENDAI), Shonan International Village, Hayama-cho, Miura-gun, Kanagawa 240-0193 (Japan); Fukagawa, Misato [Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Russell, Ray W. [The Aerospace Corporation, Los Angeles, CA 90009 (United States); Kudo, Tomoyuki [Subaru Telescope, 650 North A' ohoku Place, Hilo, HI 96720 (United States); Kusakabe, Nobuhiko [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Hashimoto, Jun [H. L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 West Brooks St., Norman, OK 73019 (United States); Abe, Lyu [Laboratoire Lagrange, UMR7293, Université de Nice-Sophia Antipolis, CNRS, Observatoire de la Côte d' Azur, 28 avenue Valrose, F-06108 Nice Cedex 2 (France); and others

    2015-01-10

    We present the first resolved near-infrared imagery of the transition disk Oph IRS 48 (WLY 2-48), which was recently observed with ALMA to have a strongly asymmetric submillimeter flux distribution. H-band polarized intensity images show a ∼60 AU radius scattered light cavity with two pronounced arcs of emission, one from northeast to southeast and one smaller, fainter, and more distant arc in the northwest. K-band scattered light imagery reveals a similar morphology, but with a clear third arc along the southwestern rim of the disk cavity. This arc meets the northwestern arc at nearly a right angle, revealing the presence of a spiral arm or local surface brightness deficit in the disk, and explaining the east-west brightness asymmetry in the H-band data. We also present 0.8-5.4 μm IRTF SpeX spectra of this object, which allow us to constrain the spectral class to A0 ± 1 and measure a low mass accretion rate of 10{sup –8.5} M {sub ☉} yr{sup –1}, both consistent with previous estimates. We investigate a variety of reddening laws in order to fit the multiwavelength spectral energy distribution of Oph IRS 48 and find a best fit consistent with a younger, higher luminosity star than previous estimates.

  1. Community wide interventions for increasing physical activity.

    Science.gov (United States)

    Baker, Philip R A; Francis, Daniel P; Soares, Jesus; Weightman, Alison L; Foster, Charles

    2015-01-05

    Multi-strategic community wide interventions for physical activity are increasingly popular but their ability to achieve population level improvements is unknown. To evaluate the effects of community wide, multi-strategic interventions upon population levels of physical activity. We searched the Cochrane Public Health Group Segment of the Cochrane Register of Studies,The Cochrane Library, MEDLINE, MEDLINE in Process, EMBASE, CINAHL, LILACS, PsycINFO, ASSIA, the British Nursing Index, Chinese CNKI databases, EPPI Centre (DoPHER, TRoPHI), ERIC, HMIC, Sociological Abstracts, SPORT Discus, Transport Database and Web of Science (Science Citation Index, Social Sciences Citation Index, Conference Proceedings Citation Index). We also scanned websites of the EU Platform on Diet, Physical Activity and Health; Health-Evidence.org; the International Union for Health Promotion and Education; the NIHR Coordinating Centre for Health Technology (NCCHTA); the US Centre for Disease Control and Prevention (CDC) and NICE and SIGN guidelines. Reference lists of all relevant systematic reviews, guidelines and primary studies were searched and we contacted experts in the field. The searches were updated to 16 January 2014, unrestricted by language or publication status. Cluster randomised controlled trials, randomised controlled trials, quasi-experimental designs which used a control population for comparison, interrupted time-series studies, and prospective controlled cohort studies were included. Only studies with a minimum six-month follow up from the start of the intervention to measurement of outcomes were included. Community wide interventions had to comprise at least two broad strategies aimed at physical activity for the whole population. Studies which randomised individuals from the same community were excluded. At least two review authors independently extracted the data and assessed the risk of bias. Each study was assessed for the setting, the number of included components

  2. Digital imaging and fabrication.

    Science.gov (United States)

    Zandparsa, Roya

    2014-01-01

    Bioceramics have been adopted in dental restorations for implants, bridges, inlays, onlays, and all-ceramic crowns. Dental bioceramics include glass ceramics, reinforced porcelains, zirconias, aluminas, fiber-reinforced ceramic composites, and multilayered ceramic structures. The process of additive manufacturing is ideally suited to dentistry. Models are designed using data from a computed tomography scan or magnetic resonance imaging. Since its development in 2001, direct ceramic machining of presintered yttria tetragonal zirconia polycrystal has become increasingly popular in dentistry. There are wide variety commercially available cements for luting all-ceramic restorations. However, resin cements have lower solubility and better aesthetic characteristics. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Selected aspects of wide-field stellar interferometry

    Science.gov (United States)

    D'Arcio, Luigi Arsenio

    1999-11-01

    In Michelson stellar interferometry, the high-resolution information about the source structure is detected by performing observations with widely separated telescopes, interconnected to form an interferometer. At optical wavelengths, this method provides a technically viable approach for achieving angular resolutions in the milliarcsecond range, comparable to those of a 100 m diameter telescope, whose realization is beyond the immediate engineering capabilities. Considerable efforts are currently devoted to the definition of dedicated interferometric instruments, which will allow to address ambitious astronomical tasks such as high-resolution imaging, astrometry at microarcsecond level, and the direct detection of exoplanets. Astrometry and related techniques employ the so-called wide field-of-view interferometric mode, where phase measurements are performed simultaneously at two (or more) sources; often, the actual observable is the instantaneous phase difference of the two object signals. The future success of wide-field interferometry critically depends on the development of techniques for the accurate control of field-dependent (anisoplanatic) phase errors. In this thesis, we address two aspects of this problem in detail. The first one is theoretical in nature. For ground-based measurements, atmospheric turbulence is the largest source of random phase fluctuations between the on- and the off-axis fringes. We developed a model of the temporal power spectrum of this disturbance, whose validity is not limited to low frequencies only, as it is the case with earlier models. This extension opens the possibility of the analysis of dynamic issues, such as the determination of the allowable coherent integration time T for the off-axis fringes. The spectrum turns out to be well approximated by a sequences of four power-law branches. In first instance, its overall form is determined by the values of the baseline length, telescope diameter, and average beam separation in

  4. A Galaxy Zoo - WorldWide Telescope Mashup: Expanding User Defined Exploration

    Science.gov (United States)

    Luebbert, Jarod; Sands, M.; Fay, J.; Smith, A.; Gay, P. L.; Galaxy Zoo Team

    2010-01-01

    We present a new way of exploring your favorite Galaxy Zoo galaxies within the context of the sky using Microsoft Research's WorldWide Telescope. Galaxy Zoo has a fantastic community that is eager to learn and contribute to science through morphological classifications of galaxies. WorldWide Telescope is an interactive observatory that allows users to explore the sky. WorldWide Telescope uses images from the world's best telescopes, including the galaxies of the Sloan Digital Sky Survey. WorldWide Telescope provides a fantastic sense of size and distance that is hard to experience in Galaxy Zoo. Creating tours from favorite galaxies directly from Galaxy Zoo aims to solve this dilemma.The incorporation of Galaxy Zoo and WorldWide telescope provides a great resource for users to learn more about the galaxies they are classifying. Users can now explore the areas around certain galaxies and view information about that location from within WorldWide Telescope. Not only does this encourage self-motivated research but after tours are created they can be shared with anyone. We hope this will help spread citizen science to different audiences via email, Facebook, and Twitter.Without the WorldWide Telescope team at Microsoft Research this project would not have been possible. Please go start exploring at http://wwt.galaxyzoo.org. This project was funded through the Microsoft Research Academic Program.

  5. Image analysis and modeling in medical image computing. Recent developments and advances.

    Science.gov (United States)

    Handels, H; Deserno, T M; Meinzer, H-P; Tolxdorff, T

    2012-01-01

    Medical image computing is of growing importance in medical diagnostics and image-guided therapy. Nowadays, image analysis systems integrating advanced image computing methods are used in practice e.g. to extract quantitative image parameters or to support the surgeon during a navigated intervention. However, the grade of automation, accuracy, reproducibility and robustness of medical image computing methods has to be increased to meet the requirements in clinical routine. In the focus theme, recent developments and advances in the field of modeling and model-based image analysis are described. The introduction of models in the image analysis process enables improvements of image analysis algorithms in terms of automation, accuracy, reproducibility and robustness. Furthermore, model-based image computing techniques open up new perspectives for prediction of organ changes and risk analysis of patients. Selected contributions are assembled to present latest advances in the field. The authors were invited to present their recent work and results based on their outstanding contributions to the Conference on Medical Image Computing BVM 2011 held at the University of Lübeck, Germany. All manuscripts had to pass a comprehensive peer review. Modeling approaches and model-based image analysis methods showing new trends and perspectives in model-based medical image computing are described. Complex models are used in different medical applications and medical images like radiographic images, dual-energy CT images, MR images, diffusion tensor images as well as microscopic images are analyzed. The applications emphasize the high potential and the wide application range of these methods. The use of model-based image analysis methods can improve segmentation quality as well as the accuracy and reproducibility of quantitative image analysis. Furthermore, image-based models enable new insights and can lead to a deeper understanding of complex dynamic mechanisms in the human body

  6. Clinical assessment of human breast cancer margins with wide-field optical coherence micro-elastography (Conference Presentation)

    Science.gov (United States)

    Allen, Wes M.; Chin, Lixin; Wijesinghe, Philip; Kirk, Rodney W.; Latham, Bruce; Sampson, David D.; Saunders, Christobel M.; Kennedy, Brendan F.

    2017-02-01

    Breast cancer has the second highest mortality rate of all cancers in females. Surgical excision of malignant tissue forms a central component of breast-conserving surgery (BCS) procedures. Incomplete excision of malignant tissue is a major issue in BCS with typically 20 - 30% cases requiring a second surgical procedure due to postoperative detection of tumor in the margin. A major challenge for surgeons during BCS is the lack of effective tools to assess the surgical margin intraoperatively. Such tools would enable the surgeon to more effectively remove all tumor during the initial surgery, hence reducing re-excision rates. We report advances in the development of a new tool, optical coherence micro-elastography, which forms images, known as elastograms, based on mechanical contrast within the tissue. We demonstrate the potential of this technique to increase contrast between malignant tumor and healthy stroma in elastograms over OCT images. We demonstrate a key advance toward clinical translation by conducting wide-field imaging in intraoperative time frames with a wide-field scanning system, acquiring mosaicked elastograms with overall dimensions of 50 × 50 mm, large enough to image an entire face of most lumpectomy specimens. We describe this wide-field imaging system, and demonstrate its operation by presenting wide-field optical coherence tomography images and elastograms of a tissue mimicking silicone phantom and a number of representative freshly excised human breast specimens. Our results demonstrate the feasibility of scanning large areas of lumpectomies, which is an important step towards practical intraoperative margin assessment.

  7. Body Imaging

    Science.gov (United States)

    2001-01-01

    The high-tech art of digital signal processing (DSP) was pioneered at NASA's Jet Propulsion Laboratory (JPL) in the mid-1960s for use in the Apollo Lunar Landing Program. Designed to computer enhance pictures of the Moon, this technology became the basis for the Landsat Earth resources satellites and subsequently has been incorporated into a broad range of Earthbound medical and diagnostic tools. DSP is employed in advanced body imaging techniques including Computer-Aided Tomography, also known as CT and CATScan, and Magnetic Resonance Imaging (MRI). CT images are collected by irradiating a thin slice of the body with a fan-shaped x-ray beam from a number of directions around the body's perimeter. A tomographic (slice-like) picture is reconstructed from these multiple views by a computer. MRI employs a magnetic field and radio waves, rather than x-rays, to create images.

  8. Simple concept for a wide-field lensless digital holographic microscope using a laser diode

    Directory of Open Access Journals (Sweden)

    Adinda-Ougba A.

    2015-09-01

    Full Text Available Wide-field, lensless digital holographic microscopy is a new microscopic imaging technique for telemedicine and for resource limited setting [1]. In this contribution we propose a very simple wide-field lensless digital holographic microscope using a laser diode. It is based on in-line digital holography which is capable to provide amplitude and phase images of a sample resulting from numerical reconstruction. The numerical reconstruction consists of the angular spectrum propagation method together with a phase retrieval algorithm. Amplitude and phase images of the sample with a resolution of ∽2 µm and with ∽24 mm2 field of view are obtained. We evaluate our setup by imaging first the 1951 USAF resolution test chart to verify the resolution. Second, we record holograms of blood smear and diatoms. The individual specimen can be easily identified after the numerical reconstruction. Our system is a very simple, compact and low-cost possibility of realizing a microscope capable of imaging biological samples. The availability of the phase provide topographic information of the sample extending the application of this system to be not only for biological sample but also for transparent microstructure. It is suitable for fault detection, shape and roughness measurements of these structures.

  9. Research on an Improved Medical Image Enhancement Algorithm Based on P-M Model.

    Science.gov (United States)

    Dong, Beibei; Yang, Jingjing; Hao, Shangfu; Zhang, Xiao

    2015-01-01

    Image enhancement can improve the detail of the image and so as to achieve the purpose of the identification of the image. At present, the image enhancement is widely used in medical images, which can help doctor's diagnosis. IEABPM (Image Enhancement Algorithm Based on P-M Model) is one of the most common image enhancement algorithms. However, it may cause the lost of the texture details and other features. To solve the problems, this paper proposes an IIEABPM (Improved Image Enhancement Algorithm Based on P-M Model). Simulation demonstrates that IIEABPM can effectively solve the problems of IEABPM, and improve image clarity, image contrast, and image brightness.

  10. Traffic Flow Wide-Area Surveillance system

    Energy Technology Data Exchange (ETDEWEB)

    Allgood, G.O.; Ferrell, R.K.; Kercel, S.W.; Abston, R.A.

    1994-09-01

    Traffic management can be thought of as a stochastic queuing process where the serving time at one of its control points is dynamically linked to the global traffic pattern, which is, in turn, dynamically linked to the control point. For this closed-loop system to be effective, the traffic management system must sense and interpret a large spatial projection of data originating from multiple sensor suites. This concept is the basis for the development of a Traffic Flow Wide-Area Surveillance (TFWAS) system. This paper presents the results of a study by Oak Ridge National Laboratory to define the operational specifications and characteristics, to determine the constraints, and to examine the state of technology of a TFWAS system in terms of traffic management and control. In doing so, the functions and attributes of a TFWAS system are mapped into an operational structure consistent with the Intelligent Vehicle Highway System (IVHS) concept and the existing highway infrastructure. This mapping includes identifying candidate sensor suites and establishing criteria, requirements, and performance measures by which these systems can be graded in their ability and practicality to meet the operational requirements of a TFWAS system. In light of this, issues such as system integration, applicable technologies, impact on traffic management and control, and public acceptance are addressed.

  11. Neurology of widely embedded free will.

    Science.gov (United States)

    de Jong, Bauke M

    2011-01-01

    Free will is classically attributed to the prefrontal cortex. In clinical neurology, prefrontal lesions have consistently been shown to cause impairment of internally driven action and increased reflex-like behaviour. Recently, parietal contributions to both free selection at early stages of sensorimotor transformations and perception of specifically self-intended movements were demonstrated in the healthy brain. Such findings generated the concept that 'free will' is not a function restricted to the prefrontal cortex but is more widely embedded in the brain, indeed including the parietal cortex. In this paper, a systematic re-interpretation of parietal symptoms, such as apraxia and reduced sense of agency, is given with reference to the consequences of reduced freedom of selection at early stages of sensorimotor transformation. Failed selection between possible movement options is argued to represent an intrinsic characteristic of apraxia. Paradoxical response facilitation supports this view. Perception of self-intended movement corresponds with a sense of agency. Impaired parietal distinction between predicted and perceived movement sensations may thus equal a restricted repertoire for selection between possible movement options of which intention is attributed to either oneself, others or an alien hand. Sense of agency, and thus perception of free will, logically fits a model of the parietal cortex as a neuronal interface between the internal drive to reach a goal and a body scheme required to select possible effectors for motor preparation. Copyright © 2011 Elsevier Srl. All rights reserved.

  12. Bitcoin – the World-Wide Currency

    Directory of Open Access Journals (Sweden)

    Shuba Olena А.

    2017-11-01

    Full Text Available The article is aimed at researching bitcoin, the digital currency. It has been found that Bitcoin is a cryptocurrency, that is, the virtual money, which has no material equivalent. The history of creation and development of cryptocurrency was reviewed. There is a reduction in volatility, which guarantees the security of currency, as well as the increase in currency volume and the inability to estimate the profitability of bitcoins. The dynamics of the value of digital currency in US dollars over recent years has been analyzed. Improvement of attitude of many countries to the considered cryptocurrency, in particular the USA, Germany, Spain, Canada, Australia, Israel and Scandinavian countries has been identified. The reasons of Ukraine’s interest in Bitcoin have been considered. Possibilities of creation of cryptocurrency on the territory of Ukraine have been analyzed, i.e. cost of electricity for mining, the legal status of mining firms, and the attitude of the National Bank of Ukraine to the digital currency. It has been concluded that the recognition of Bitcoin by the world countries in the future will allow it to be granted the status of world-wide currency.

  13. Traffic flow wide-area surveillance system

    Science.gov (United States)

    Allgood, Glenn O.; Ferrell, Regina K.; Kercel, Stephen W.; Abston, Ruth A.

    1995-01-01

    Traffic management can be thought of as a stochastic queuing process where the serving time at one of its control points is dynamically linked to the global traffic pattern, which is, in turn, dynamically linked to the control point. For this closed-loop system to be effective, the traffic management system must sense and interpret a large spatial projection of data originating from multiple sensor suites. This concept is the basis for the development of a traffic flow wide-area surveillance (TFWAS) system. This paper presents the results of a study by Oak Ridge National Laboratory to define the operational specifications and characteristics, to determine the constraints, and to examine the state of technology of a TFWAS system in terms of traffic management and control. In doing so, the functions and attributes of a TFWAS system are mapped into an operational structure consistent with the Intelligent Vehicle Highway System (IVHS) concept and the existing highway infrastructure. This mapping includes identifying candidate sensor suites and establishing criteria, requirements, and performance measures by which these systems can be graded in their ability and practicality to meet the operational requirements of a TFWAS system. In light of this, issues such as system integration, applicable technologies, impact on traffic management and control, and public acceptance are addressed.

  14. Faciocardiorenal syndrome: a wide clinical spectrum?

    Science.gov (United States)

    Brambila Tapia, A J L; Vásquez Velásque, A I; González Mercado, M G; Macías Chumacera, A; Gutierrez-Amavizca, B E; Lara Aguilar, R A; Pérez Juárez, Canton R; Moreno Andrade, A; Figuera, L E

    2012-01-01

    Faciocardiorenal syndrome (FCRS), also named Eastman-Bixler syndrome, is an apparent autosomal recessive entity, characterized by endocardial fibroelastosis, unusual facial appearance, renal defects and mental retardation. We report a 7 months male patient, with the diagnosis of endocardial fibroelastosis, an abnormal facial appearance (arched eyebrows, broad nasal root, long philtrum and microretrognathia) and psychomotor delay. Associated anomalies were: plagiocephaly, broad halluces, nail hypoplasia, cryptorchidism, diastasis recti, and adducted thumbs. Focal seizures in the mouth were also observed. The radiographs revealed advanced bone age and metaphyseal widening of femur and tibia. FCRS has an unknown etiology with only three reported cases so far (since 1977). We report a patient with the main features of FCRS but without the renal component, suggesting that this entity can present a wide clinical spectrum. Based on these findings and on the few previously reported cases with a highly variable phenotype when compared with the original report, we suggest that FCRS should be further clinical delineated according to the following leading anomalies: endocardial fibroelastosis, unusual facial appearance and mental retardation, in order to find more cases that allow a wider clinical description and the identification of the genetic defect(s).

  15. Golden Jubilee Photos: World Wide Web

    CERN Multimedia

    2004-01-01

    At the end of the 1980s, the Internet was already a valuable tool to scientists, allowing them to exchange e-mails and to access powerful computers remotely. A more simple means of sharing information was needed, however, and CERN, with its long tradition of informatics and networking, was the ideal place to find it. Moreover, hundreds of scientists from all over the world were starting to work together on preparations for the experiments at the Large Electron-Positron (LEP) collider. In 1989, Tim Berners-Lee (see photo), a young scientist working at CERN, drafted a proposal for an information-management system combining the internet, personal computers and computer-aided document consultation, known as hypertext. In 1990 he was joined by Robert Cailliau and the weaving of the World Wide Web began in earnest, even though only two CERN computers were allocated to the task at the time. The Web subsequently underwent a steady expansion to include the world's main particle physics institutes. The Web was not the...

  16. Monitoring city wide patterns of cycling safety.

    Science.gov (United States)

    Boss, Darren; Nelson, Trisalyn; Winters, Meghan

    2018-02-01

    Many cities are making significant financial investments in cycling infrastructure with the aim of making cycling safer for riders of all ages and abilities. Methods for evaluating cycling safety tend to summarize average change for a city or emphasize change on a single road segment. Few spatially explicit approaches are available to evaluate how patterns of safety change throughout a city due to cycling infrastructure investments or other changes. Our goal is to demonstrate a method for monitoring changes in the spatial-temporal distribution of cycling incidents across a city. Using cycling incident data provided by the Insurance Corporation of British Columbia, we first compare planar versus network constrained kernel density estimation for visualizing incident intensity across the street network of Vancouver, Canada. Second, we apply a change detection algorithm explicitly designed for detecting statistically significant change in kernel density estimates. The utility of network kernel density change detection is demonstrated through the comparison of cycling incident densities following the construction of two cycle tracks in the downtown core of Vancouver. The methods developed and demonstrated for this study provide city planners, transportation engineers and researchers a means of monitoring city-wide change in the intensity of cycling incidents following enhancements to cycling infrastructure or other significant changes to the transportation network. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Emerging images

    KAUST Repository

    Mitra, Niloy J.

    2009-01-01

    Emergence refers to the unique human ability to aggregate information from seemingly meaningless pieces, and to perceive a whole that is meaningful. This special skill of humans can constitute an effective scheme to tell humans and machines apart. This paper presents a synthesis technique to generate images of 3D objects that are detectable by humans, but difficult for an automatic algorithm to recognize. The technique allows generating an infinite number of images with emerging figures. Our algorithm is designed so that locally the synthesized images divulge little useful information or cues to assist any segmentation or recognition procedure. Therefore, as we demonstrate, computer vision algorithms are incapable of effectively processing such images. However, when a human observer is presented with an emergence image, synthesized using an object she is familiar with, the figure emerges when observed as a whole. We can control the difficulty level of perceiving the emergence effect through a limited set of parameters. A procedure that synthesizes emergence images can be an effective tool for exploring and understanding the factors affecting computer vision techniques. © 2009 ACM.

  18. A Wide New Window on the Universe

    Energy Technology Data Exchange (ETDEWEB)

    Hazi, A

    2006-01-25

    For decades, ground-based astronomy has consisted mostly of a lone astronomer earning the right to train a powerful telescope for a few nights on an extremely small patch of sky. If the astronomer is fortunate, a celestial discovery will be shared many months later with colleagues through a journal article or private correspondence. Lawrence Livermore is a major partner in a new telescope project that promises to forever change that scenario--and all of astronomy--by taking advantage of advanced optical manufacturing techniques, digital imaging, supercomputer data processing, and the Internet. The ground-based Large Synoptic Survey Telescope (LSST), scheduled for completion in 2012, will provide, for the first time, digital imaging of objects, including changing events, in deep space across the entire sky. Data from LSST's Reprinted from Science & Technology Review, November 2005 UCRL-TR-218446 observation will catch a transient event. Furthermore, such an instrument would take many years to map the entire sky. Current all-sky maps made with smaller telescopes are limited in depth (faintness) and detail. LSST will overcome these drawbacks by mapping the entire sky deeply, rapidly, and continuously with a 10-square-degree field of view. What's more, when the telescope detects an object of interest, such as an exploding supernova, it will send out an alert for more specialized telescopes to follow up with higher resolution images. Livermore researchers are participating in all aspects of the LSST project, from management to research efforts. For example, Bill Goldstein, associate director of the Physics and Advanced Technologies (PAT) Directorate, is on the governing board of the nonprofit LSST Corporation. Physicist Don Sweeney is the LSST project manager and manages the entire LSST effort from the project offices in Tucson, Arizona. Astrophysicist Kem Cook is a key member of the LSST science team astronomical surveys will be accessible almost immediately

  19. Review of advanced imaging techniques.

    Science.gov (United States)

    Chen, Yu; Liang, Chia-Pin; Liu, Yang; Fischer, Andrew H; Parwani, Anil V; Pantanowitz, Liron

    2012-01-01

    Pathology informatics encompasses digital imaging and related applications. Several specialized microscopy techniques have emerged which permit the acquisition of digital images ("optical biopsies") at high resolution. Coupled with fiber-optic and micro-optic components, some of these imaging techniques (e.g., optical coherence tomography) are now integrated with a wide range of imaging devices such as endoscopes, laparoscopes, catheters, and needles that enable imaging inside the body. These advanced imaging modalities have exciting diagnostic potential and introduce new opportunities in pathology. Therefore, it is important that pathology informaticists understand these advanced imaging techniques and the impact they have on pathology. This paper reviews several recently developed microscopic techniques, including diffraction-limited methods (e.g., confocal microscopy, 2-photon microscopy, 4Pi microscopy, and spatially modulated illumination microscopy) and subdiffraction techniques (e.g., photoactivated localization microscopy, stochastic optical reconstruction microscopy, and stimulated emission depletion microscopy). This article serves as a primer for pathology informaticists, highlighting the fundamentals and applications of advanced optical imaging techniques.

  20. Review of advanced imaging techniques

    Directory of Open Access Journals (Sweden)

    Yu Chen

    2012-01-01

    Full Text Available Pathology informatics encompasses digital imaging and related applications. Several specialized microscopy techniques have emerged which permit the acquisition of digital images ("optical biopsies" at high resolution. Coupled with fiber-optic and micro-optic components, some of these imaging techniques (e.g., optical coherence tomography are now integrated with a wide range of imaging devices such as endoscopes, laparoscopes, catheters, and needles that enable imaging inside the body. These advanced imaging modalities have exciting diagnostic potential and introduce new opportunities in pathology. Therefore, it is important that pathology informaticists understand these advanced imaging techniques and the impact they have on pathology. This paper reviews several recently developed microscopic techniques, including diffraction-limited methods (e.g., confocal microscopy, 2-photon microscopy, 4Pi microscopy, and spatially modulated illumination microscopy and subdiffraction techniques (e.g., photoactivated localization microscopy, stochastic optical reconstruction microscopy, and stimulated emission depletion microscopy. This article serves as a primer for pathology informaticists, highlighting the fundamentals and applications of advanced optical imaging techniques.

  1. The UKIRT wide-field camera (WFCAM): commissioning and performance on the telescope

    Science.gov (United States)

    Hirst, Paul; Casali, Mark; Adamson, Andy; Ives, Derek; Kerr, Tom

    2006-06-01

    The UKIRT Wide-Field Camera (WFCAM) was commissioned in two phases between October and December 2004, and March and April 2005. It has been carrying out full-scale sky survey operations since May 2005. This paper describes the commissioning process and compares actual performance on the telescope with specifications in four key areas: optical image quality including delivered FWHM and ghosting etc., noise and sensitivity in the infrared and on the visible autoguider, array artifacts such as crosstalk and persistent images, and observing efficiency. A comprehensive program of science verification was carried out before commencing the UKIRT Infrared Deep Sky Survey (UKIDSS).

  2. Data analysis using the Internet: the World Wide Web scanning probe microscopy data analysis system.

    Science.gov (United States)

    Williams, P M; Davies, M C; Roberts, C J; Tendler, S J

    1997-10-01

    The first interactive world-wide web-based image analysis system is presented (http://pharm6.pharm.nottingham.ac.uk/processing/main. html). The system, currently tailored to scanning probe microscopy image data, has been developed to permit the use of software algorithms developed within our laboratory by researchers throughout the world. The implementation and functionality of the scanning probe microscopy server is described. Feedback from users of the facility has demonstrated its value within the research community, and highlighted key operational issues which are to be addressed. A future role of Internet-based data processing software is also discussed.

  3. World Wide Web of Your Wide Web? Juridische aspecten van zoekmachine-personalisatie

    NARCIS (Netherlands)

    Oostveen, M.

    2012-01-01

    Het world wide web is een enorme bron van informatie. Iedere internetgebruiker maakt gebruik van zoekmachines om die informatie te kunnen vinden. Veel gebruikers weten echter niet dat zoekresultaten behorende bij een bepaalde zoekterm niet voor iedereen hetzelfde zijn. Dit personaliseren van

  4. Robustness of an artificially tailored fisheye imaging system with a curvilinear image surface

    Science.gov (United States)

    Lee, Gil Ju; Nam, Won Il; Song, Young Min

    2017-11-01

    Curved image sensors inspired by animal and insect eyes have provided a new development direction in next-generation digital cameras. It is known that natural fish eyes afford an extremely wide field of view (FOV) imaging due to the geometrical properties of the spherical lens and hemispherical retina. However, its inherent drawbacks, such as the low off-axis illumination and the fabrication difficulty of a 'dome-like' hemispherical imager, limit the development of bio-inspired wide FOV cameras. Here, a new type of fisheye imaging system is introduced that has simple lens configurations with a curvilinear image surface, while maintaining high off-axis illumination and a wide FOV. Moreover, through comparisons with commercial conventional fisheye designs, it is determined that the volume and required number of optical elements of the proposed design is practical while capturing the fundamental optical performances. Detailed design guidelines for tailoring the proposed optic system are also discussed.

  5. Selections from 2017: Image Processing with AstroImageJ

    Science.gov (United States)

    Kohler, Susanna

    2017-12-01

    Editors note:In these last two weeks of 2017, well be looking at a few selections that we havent yet discussed on AAS Nova from among the most-downloaded paperspublished in AAS journals this year. The usual posting schedule will resume in January.AstroImageJ: Image Processing and Photometric Extraction for Ultra-Precise Astronomical Light CurvesPublished January2017The AIJ image display. A wide range of astronomy specific image display options and image analysis tools are available from the menus, quick access icons, and interactive histogram. [Collins et al. 2017]Main takeaway:AstroImageJ is a new integrated software package presented in a publication led byKaren Collins(Vanderbilt University,Fisk University, andUniversity of Louisville). Itenables new users even at the level of undergraduate student, high school student, or amateur astronomer to quickly start processing, modeling, and plotting astronomical image data.Why its interesting:Science doesnt just happen the momenta telescope captures a picture of a distantobject. Instead, astronomical images must firstbe carefully processed to clean up thedata, and this data must then be systematically analyzed to learn about the objects within it. AstroImageJ as a GUI-driven, easily installed, public-domain tool is a uniquelyaccessible tool for thisprocessing and analysis, allowing even non-specialist users to explore and visualizeastronomical data.Some features ofAstroImageJ:(as reported by Astrobites)Image calibration:generate master flat, dark, and bias framesImage arithmetic:combineimages viasubtraction, addition, division, multiplication, etc.Stack editing:easily perform operations on a series of imagesImage stabilization and image alignment featuresPrecise coordinate converters:calculate Heliocentric and Barycentric Julian DatesWCS coordinates:determine precisely where atelescope was pointed for an image by PlateSolving using Astronomy.netMacro and plugin support:write your own macrosMulti-aperture photometry

  6. Genome wide application of DNA melting analysis.

    Science.gov (United States)

    Jost, Daniel; Everaers, Ralf

    2009-01-21

    Correspondences between functional and thermodynamic melting properties in a genome are being increasingly employed for ab initio gene finding and for the interpretation of the evolution of genomes. Here we present the first systematic genome wide comparison between biologically coding domains and thermodynamically stable regions. In particular, we develop statistical methods to estimate the reliability of the resulting predictions. Not surprisingly, we find that the success of the approach depends on the difference in GC content between the coding and the non-coding parts of the genome and on the percentage of coding base-pairs in the sequence. These prerequisites vary strongly between species, where we observe no systematic differences between eukaryotes and prokaryotes. We find a number of organisms in which the strong correlation of coding domains and thermodynamically stable regions allows us to identify putative exons or genes to complement existing approaches. In contrast to previous investigations along these lines we have not employed the Poland-Scheraga (PS) model of DNA melting but use the earlier Zimm-Bragg (ZB) model. The Ising-like form of the ZB model can be viewed as an approximation to the PS model, with averaged loop entropies included into the cooperative factor [Formula: see text]. This results in a speed-up by a factor of 20-100 compared to the Fixman-Freire algorithm for the solution of the PS model. We show that for genomic sequences the resulting systematic errors are negligible compared to the parameterization uncertainty of the models. We argue that for limited computing resources, available CPU power is better invested in broadening the statistical base for genomic investigations than in marginal improvements of the description of the physical melting behavior.

  7. Genome wide selection in Citrus breeding.

    Science.gov (United States)

    Gois, I B; Borém, A; Cristofani-Yaly, M; de Resende, M D V; Azevedo, C F; Bastianel, M; Novelli, V M; Machado, M A

    2016-10-17

    Genome wide selection (GWS) is essential for the genetic improvement of perennial species such as Citrus because of its ability to increase gain per unit time and to enable the efficient selection of characteristics with low heritability. This study assessed GWS efficiency in a population of Citrus and compared it with selection based on phenotypic data. A total of 180 individual trees from a cross between Pera sweet orange (Citrus sinensis Osbeck) and Murcott tangor (Citrus sinensis Osbeck x Citrus reticulata Blanco) were evaluated for 10 characteristics related to fruit quality. The hybrids were genotyped using 5287 DArT_seq TM (diversity arrays technology) molecular markers and their effects on phenotypes were predicted using the random regression - best linear unbiased predictor (rr-BLUP) method. The predictive ability, prediction bias, and accuracy of GWS were estimated to verify its effectiveness for phenotype prediction. The proportion of genetic variance explained by the markers was also computed. The heritability of the traits, as determined by markers, was 16-28%. The predictive ability of these markers ranged from 0.53 to 0.64, and the regression coefficients between predicted and observed phenotypes were close to unity. Over 35% of the genetic variance was accounted for by the markers. Accuracy estimates with GWS were lower than those obtained by phenotypic analysis; however, GWS was superior in terms of genetic gain per unit time. Thus, GWS may be useful for Citrus breeding as it can predict phenotypes early and accurately, and reduce the length of the selection cycle. This study demonstrates the feasibility of genomic selection in Citrus.

  8. Wide Bandgap Semiconductor Opportunities in Power Electronics

    Energy Technology Data Exchange (ETDEWEB)

    Das, Sujit [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Marlino, Laura D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Armstrong, Kristina O. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2018-01-01

    The report objective is to explore the Wide Bandgap (WBG) Power Electronics (PE) market, applications, and potential energy savings in order to identify key areas where further resources and investments of the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (DOE EERE) would have the most impact on U.S. competiveness. After considering the current market, several potential near-term application areas were identified as having significant market and energy savings potential with respect to clean energy applications: (1) data centers (uninterruptible power supplies and server power supplies); (2) renewable energy generation (photovoltaic-solar and wind); (3) motor drives (industrial, commercial and residential); (4) rail traction; and, (5) hybrid and electric vehicles (traction and charging). After the initial explorative analyses, it became clear that, SiC, not GaN, would be the principal WBG power device material for the chosen markets in the near future. Therefore, while GaN is discussed when appropriate, this report focuses on SiC devices, other WBG applications (e.g., solid-state transformers, combined heat and power, medical, and wireless power), the GaN market, and GaN specific applications (e.g., LiDAR, 5G) will be explored at a later date. In addition to the market, supply and value chain analyses addressed in Section 1 of this report, a SWOT (Strength, Weakness, Opportunity, Threat) analysis and potential energy savings analysis was conducted for each application area to identify the major potential WBG application area(s) with a U.S. competitiveness opportunity in the future.

  9. Wide Area Security Region Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Makarov, Yuri V.; Lu, Shuai; Guo, Xinxin; Gronquist, James; Du, Pengwei; Nguyen, Tony B.; Burns, J. W.

    2010-03-31

    This report develops innovative and efficient methodologies and practical procedures to determine the wide-area security region of a power system, which take into consideration all types of system constraints including thermal, voltage, voltage stability, transient and potentially oscillatory stability limits in the system. The approach expands the idea of transmission system nomograms to a multidimensional case, involving multiple system limits and parameters such as transmission path constraints, zonal generation or load, etc., considered concurrently. The security region boundary is represented using its piecewise approximation with the help of linear inequalities (so called hyperplanes) in a multi-dimensional space, consisting of system parameters that are critical for security analyses. The goal of this approximation is to find a minimum set of hyperplanes that describe the boundary with a given accuracy. Methodologies are also developed to use the security hyperplanes, pre-calculated offline, to determine system security margins in real-time system operations, to identify weak elements in the system, and to calculate key contributing factors and sensitivities to determine the best system controls in real time and to assist in developing remedial actions and transmission system enhancements offline . A prototype program that automates the simulation procedures used to build the set of security hyperplanes has also been developed. The program makes it convenient to update the set of security hyperplanes necessitated by changes in system configurations. A prototype operational tool that uses the security hyperplanes to assess security margins and to calculate optimal control directions in real time has been built to demonstrate the project success. Numerical simulations have been conducted using the full-size Western Electricity Coordinating Council (WECC) system model, and they clearly demonstrated the feasibility and the effectiveness of the developed

  10. Terpene synthases are widely distributed in bacteria

    Science.gov (United States)

    Yamada, Yuuki; Kuzuyama, Tomohisa; Komatsu, Mamoru; Shin-ya, Kazuo; Omura, Satoshi; Cane, David E.; Ikeda, Haruo

    2015-01-01

    Odoriferous terpene metabolites of bacterial origin have been known for many years. In genome-sequenced Streptomycetaceae microorganisms, the vast majority produces the degraded sesquiterpene alcohol geosmin. Two minor groups of bacteria do not produce geosmin, with one of these groups instead producing other sesquiterpene alcohols, whereas members of the remaining group do not produce any detectable terpenoid metabolites. Because bacterial terpene synthases typically show no significant overall sequence similarity to any other known fungal or plant terpene synthases and usually exhibit relatively low levels of mutual sequence similarity with other bacterial synthases, simple correlation of protein sequence data with the structure of the cyclized terpene product has been precluded. We have previously described a powerful search method based on the use of hidden Markov models (HMMs) and protein families database (Pfam) search that has allowed the discovery of monoterpene synthases of bacterial origin. Using an enhanced set of HMM parameters generated using a training set of 140 previously identified bacterial terpene synthase sequences, a Pfam search of 8,759,463 predicted bacterial proteins from public databases and in-house draft genome data has now revealed 262 presumptive terpene synthases. The biochemical function of a considerable number of these presumptive terpene synthase genes could be determined by expression in a specially engineered heterologous Streptomyces host and spectroscopic identification of the resulting terpene products. In addition to a wide variety of terpenes that had been previously reported from fungal or plant sources, we have isolated and determined the complete structures of 13 previously unidentified cyclic sesquiterpenes and diterpenes. PMID:25535391

  11. Geomorphology and the World Wide Web

    Science.gov (United States)

    Shroder, John F.; Bishop, Michael P.; Olsenholler, Jeffrey; Craiger, J. Philip

    2002-10-01

    The Internet and the World Wide Web have brought many dimensions of new technology to education and research in geomorphology. As with other disciplines on the Web, Web-based geomorphology has become an eclectic mix of whatever material an individual deems worthy of presentation, and in many cases is without quality control. Nevertheless, new electronic media can facilitate education and research in geomorphology. For example, virtual field trips can be developed and accessed to reinforce concepts in class. Techniques for evaluating Internet references helps students to write traditional term papers, but professional presentations can also involve student papers that are published on the Web. Faculty can also address plagiarism issues by using search engines. Because of the lack of peer review of much of the content on the Web, care must be exercised in using it for reference searches. Today, however, refereed journals are going online and can be accessed through subscription or payment per article viewed. Library reference desks regularly use the Web for searches of refereed articles. Research on the Web ranges from communication between investigators, data acquisition, scientific visualization, or comprehensive searches of refereed sources, to interactive analyses of remote data sets. The Nanga Parbat and the Global Land Ice Measurements from Space (GLIMS) Projects are two examples of geomorphologic research that are achieving full potential through use of the Web. Teaching and research in geomorphology are undergoing a beneficial, but sometimes problematic, transition with the new technology. The learning curve is steep for some users but the view from the top is bright. Geomorphology can only prosper from the benefits offered by computer technologies.

  12. System-wide immunohistochemical analysis of protein co-localization.

    Directory of Open Access Journals (Sweden)

    Minjung Kim

    Full Text Available The analysis of co-localized protein expression in a tissue section is often conducted with immunofluorescence histochemical staining which is typically visualized in localized regions. On the other hand, chromogenic immunohistochemical staining, in general, is not suitable for the detection of protein co-localization. Here, we developed a new protocol, based on chromogenic immunohistochemical stain, for system-wide detection of protein co-localization and differential expression.In combination with a removable chromogenic stain, an efficient antibody stripping method was developed to enable sequential immunostaining with different primary antibodies regardless of antibody's host species. Sections were scanned after each staining, and the images were superimposed together for the detection of protein co-localization and differential expression. As a proof of principle, differential expression and co-localization of glutamic acid decarboxylase67 (GAD67 and parvalbumin proteins was examined in mouse cortex.All parvalbumin-containing neurons express GAD67 protein, and GAD67-positive neurons that do not express parvalbumin were readily visualized from thousands of other neurons across mouse cortex. The method provided a global view of protein co-localization as well as differential expression across an entire tissue section. Repeated use of the same section could combine assessments of co-localization and differential expression of multiple proteins.

  13. Wide Stiffness Range Cavity Optomechanical Sensors for Atomic Force Microscopy

    CERN Document Server

    Liu, Yuxiang; Aksyuk, Vladimir; Srinivasan, Kartik

    2012-01-01

    We report on progress in developing compact sensors for atomic force microscopy (AFM), in which the mechanical transducer is integrated with near-field optical readout on a single chip. The motion of a nanoscale, doubly-clamped cantilever was transduced by an adjacent high quality factor silicon microdisk cavity. In particular, we show that displacement sensitivity on the order of 1 fm/(Hz)^(1/2) can be achieved while the cantilever stiffness is varied over four orders of magnitude (\\approx 0.01 N/m to \\approx 290 N/m). The ability to transduce both very soft and very stiff cantilevers extends the domain of applicability of this technique, potentially ranging from interrogation of microbiological samples (soft cantilevers) to imaging with high resolution (stiff cantilevers). Along with mechanical frequencies (> 250 kHz) that are much higher than those used in conventional AFM probes of similar stiffness, these results suggest that our cavity optomechanical sensors may have application in a wide variety of hig...

  14. Hubble Images Reveal Jupiter's Auroras

    Science.gov (United States)

    1996-01-01

    These images, taken by the Hubble Space Telescope, reveal changes in Jupiter's auroral emissions and how small auroral spots just outside the emission rings are linked to the planet's volcanic moon, Io. The images represent the most sensitive and sharply-detailed views ever taken of Jovian auroras.The top panel pinpoints the effects of emissions from Io, which is about the size of Earth's moon. The black-and-white image on the left, taken in visible light, shows how Io and Jupiter are linked by an invisible electrical current of charged particles called a 'flux tube.' The particles - ejected from Io (the bright spot on Jupiter's right) by volcanic eruptions - flow along Jupiter's magnetic field lines, which thread through Io, to the planet's north and south magnetic poles. This image also shows the belts of clouds surrounding Jupiter as well as the Great Red Spot.The black-and-white image on the right, taken in ultraviolet light about 15 minutes later, shows Jupiter's auroral emissions at the north and south poles. Just outside these emissions are the auroral spots. Called 'footprints,' the spots are created when the particles in Io's 'flux tube' reach Jupiter's upper atmosphere and interact with hydrogen gas, making it fluoresce. In this image, Io is not observable because it is faint in the ultraviolet.The two ultraviolet images at the bottom of the picture show how the auroral emissions change in brightness and structure as Jupiter rotates. These false-color images also reveal how the magnetic field is offset from Jupiter's spin axis by 10 to 15 degrees. In the right image, the north auroral emission is rising over the left limb; the south auroral oval is beginning to set. The image on the left, obtained on a different date, shows a full view of the north aurora, with a strong emission inside the main auroral oval.The images were taken by the telescope's Wide Field and Planetary Camera 2 between May 1994 and September 1995.This image and other images and data

  15. Molecular imaging. Fundamentals and applications

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Jie (ed.) [Chinese Academy of Sciences, Beijing (China). Intelligent Medical Research Center

    2013-07-01

    Covers a wide range of new theory, new techniques and new applications. Contributed by many experts in China. The editor has obtained the National Science and Technology Progress Award twice. ''Molecular Imaging: Fundamentals and Applications'' is a comprehensive monograph which describes not only the theory of the underlying algorithms and key technologies but also introduces a prototype system and its applications, bringing together theory, technology and applications. By explaining the basic concepts and principles of molecular imaging, imaging techniques, as well as research and applications in detail, the book provides both detailed theoretical background information and technical methods for researchers working in medical imaging and the life sciences. Clinical doctors and graduate students will also benefit from this book.

  16. How images make world politics

    DEFF Research Database (Denmark)

    Hansen, Lene

    2015-01-01

    of the icon into new images. Appropriations might be used and read as critical interventions into foreign policy debates, but such readings should themselves be subjected to analysis. A three-tier analytical and methodological framework for studying international icons is presented and applied in a case study......This article introduces international icons to the field of International Relations. International icons are freestanding images that are widely circulated, recognised, and emotionally responded to. International icons come in the form of foreign policy icons familiar to a specific domestic...... audience, regional icons, and global icons. Icons do not speak foreign policy in and of themselves rather their meaning is constituted in discourse. Images rise to the status of international icons in part through images that appropriate the icon itself, either in full or through inserting parts...

  17. Presenting 3-D models of geological materials on the World Wide Web

    Science.gov (United States)

    Marschallinger, R.; Johnson, S. E.

    2001-05-01

    In this article, we show how current World Wide Web technology can be used to present computerized 3-D models of geological materials. Unlike traditional, paper-based publishing, World Wide Web documents can incorporate several visualization techniques, some of which allow interactive user control. The concepts behind still images, animations, video sequences, object movies and virtual reality models are introduced. The advantages and pitfalls of the different visualization techniques are described, and their potential for the communication of 3-D models of geological materials is discussed. Web-resources providing the necessary browsing, playback and interaction software as well as specific authoring tools are referenced. In the HTML version of this article, which can be found on the accompanying CD-ROM, examples of 3-D macro- and microstructure reconstructions of geological materials are included as color images, animated sequences and interactive 3-D models.

  18. Reconstruction of Optical Thickness from Hoffman Modulation Contrast Images

    DEFF Research Database (Denmark)

    Olsen, Niels Holm; Sporring, Jon; Nielsen, Mads

    2003-01-01

    Hoffman microscopy imaging systems are part of numerous fertility clinics world-wide. We discuss the physics of the Hoffman imaging system from optical thickness to image intensity, implement a simple, yet fast, reconstruction algorithm using Fast Fourier Transformation and discuss the usability...

  19. Ensembles of Novel Visual Keywords Descriptors for Image Categorization

    NARCIS (Netherlands)

    Abdullah, Azizi; Veltkamp, Remco C.; Wiering, Marco

    2010-01-01

    Object recognition systems need effective image descriptors to obtain good performance levels. Currently, the most widely used image descriptor is the SIFT descriptor that computes histograms of orientation gradients around points in an image. A possible problem of this approach is that the number

  20. Image processing techniques for quantification and assessment of brain MRI

    NARCIS (Netherlands)

    Kuijf, H.J.

    2013-01-01

    Magnetic resonance imaging (MRI) is a widely used technique to acquire digital images of the human brain. A variety of acquisition protocols is available to generate images in vivo and noninvasively, giving great opportunities to study the anatomy and physiology of the human brain. In my thesis,

  1. Analysis of Fourier ptychographic microscopy with half reduced images

    Science.gov (United States)

    Zhou, Ao; Chen, Ni; Situ, Guohai

    2018-01-01

    Fourier ptychography microscopy (FPM) provides gigapixel imaging with both a high image resolution and a wide field-of-view (FOV). However, it is time consuming during the image capture process. In this paper, we perform an analysis on the FPM imaging process. With numerical and experimental comparison, we find that the reconstructed high resolution images with half number of the total captured images is less degenerated compare to that using all the captured images, especially in the case that the object is amplitude or phase-only.

  2. Deployable Wide-Aperture Array Antennas

    Science.gov (United States)

    Fink, Patrick W.; Dobbins, Justin A.; Lin, Greg Y.; Chu, Andrew; Scully, Robert C.

    2005-01-01

    membrane, can also be used. Finally, wide bandwidth antennas or arrays can be formed in which the principal direction of radiation is in the plane of the membrane. For this embodiment, the set of elements on the membrane is arranged to form one or more traveling wave antennas. In this case, a nonconductive form of the perimeter springlike material is required to provide the deploying force.

  3. Developing Basic Space Science World-Wide

    Science.gov (United States)

    Wamsteker, W.; Albrecht, Rudolf; Haubold, Hans J.

    2004-03-01

    When the first United Nations/European Space Agency Workshop for Basic Space Science was planned to be held in Bangalore, India (1991) on the invitation of ISRO, few of those involved could expect that a unique forum was going to be created for scientific dialogue between scientists from developing and industrialized nations. As the format of the first workshop was on purpose left free with time for presentations, working sessions, and plenary discussions, the workshop was left to find its own dynamics. After a decade of UN/ESA Workshops, this book brings together the historical activities, the plans which have been developed over the past decade in the different nations, and the results which have materialized during this time in different developing nations. It aims to achieve for development agencies to be assisted in ways to find more effective tools for the application of development aid. The last section of the book contains a guide for teachers to introduce astrophysics into university physics courses. This will be of use to teachers in many nations. Everything described in this book is the result of a truly collective effort from all involved in all UN/ESA workshops. The mutual support from the participants has helped significantly to implement some of the accomplishments described in the book. Rather than organizing this book in a subject driven way, it is essentially organized according to the common economic regions of the world, as defined by the United Nations (Africa, Asia and the Pacific, Europe, Latin America and the Caribbean, Western Asia). This allows better recognition of the importance of a regional (and at times) global approach to basic space science for the developing nation's world wide. It highlights very specific scientific investigations which have been completed successfully in the various developing nations. The book supplements the published ten volumes of workshop proceedings containing scientific papers presented in the workshops

  4. Real Time Wide Area Radiation Surveillance System

    Science.gov (United States)

    Biafore, M.

    2012-04-01

    We present the REWARD project, financed within the FP7 programme, theme SEC-2011.1.5-1 (Development of detection capabilities of difficult to detect radioactive sources and nuclear materials - Capability Project). Within this project, we propose a novel mobile system for real time, wide area radiation surveillance. The system is based on the integration of new miniaturized solid-state radiation sensors: a CdZnTe detector for gamma radiation and a high efficiency neutron detector based on novel silicon technologies. The sensing unit will include a wireless communication interface to send the data remotely to a monitoring base station which also uses a GPS system to calculate the position of the tag. The system will also incorporate middleware and high level software to provide web-service interfaces for the exchange of information, and that will offer top level functionalities as management of users, mobile tags and environment data and alarms, database storage and management and a web-based graphical user interface. Effort will be spent to ensure that the software is modular and re-usable across as many architectural levels as possible. Finally, an expert system will continuously analyze the information from the radiation sensor and correlate it with historical data from the tag location in order to generate an alarm when an abnormal situation is detected. The system will be useful for many different scenarios, including such lost radioactive sources and radioactive contamination. It will be possible to deploy in emergency units and in general in any type of mobile or static equipment. The sensing units will be highly portable thanks to their low size and low energy consumption. The complete system will be scalable in terms of complexity and cost and will offer very high precision on both the measurement and the location of the radiation. The modularity and flexibility of the system will allow for a realistic introduction to the market. Authorities may start with a

  5. Multi-dimensional effects of color on the world wide web

    Science.gov (United States)

    Morton, Jill

    2002-06-01

    Color is the most powerful building material of visual imagery on the World Wide Web. It must function successfully as it has done historically in traditional two-dimensional media, as well as address new challenges presented by this electronic medium. The psychological, physiological, technical and aesthetic effects of color have been redefined by the unique requirements of the electronic transmission of text and images on the Web. Color simultaneously addresses each of these dimensions in this electronic medium.

  6. Camera Networks The Acquisition and Analysis of Videos over Wide Areas

    CERN Document Server

    Roy-Chowdhury, Amit K

    2012-01-01

    As networks of video cameras are installed in many applications like security and surveillance, environmental monitoring, disaster response, and assisted living facilities, among others, image understanding in camera networks is becoming an important area of research and technology development. There are many challenges that need to be addressed in the process. Some of them are listed below: - Traditional computer vision challenges in tracking and recognition, robustness to pose, illumination, occlusion, clutter, recognition of objects, and activities; - Aggregating local information for wide

  7. Laser light-field fusion for wide-field lensfree on-chip phase contrast nanoscopy

    OpenAIRE

    Kazemzadeh, Farnoud; Wong, Alexander

    2016-01-01

    Wide-field lensfree on-chip microscopy, which leverages holography principles to capture interferometric light-field encodings without lenses, is an emerging imaging modality with widespread interest given the large field-of-view compared to lens-based techniques. In this study, we introduce the idea of laser light-field fusion for lensfree on-chip phase contrast nanoscopy, where interferometric laser light-field encodings acquired using an on-chip setup with laser pulsations at different wav...

  8. Imaging of Muscle Injuries in Sports Medicine: Sports Imaging Series.

    Science.gov (United States)

    Guermazi, Ali; Roemer, Frank W; Robinson, Philip; Tol, Johannes L; Regatte, Ravindar R; Crema, Michel D

    2017-03-01

    In sports-related muscle injuries, the main goal of the sports medicine physician is to return the athlete to competition-balanced against the need to prevent the injury from worsening or recurring. Prognosis based on the available clinical and imaging information is crucial. Imaging is crucial to confirm and assess the extent of sports-related muscle injuries and may help to guide management, which directly affects the prognosis. This is especially important when the diagnosis or grade of injury is unclear, when recovery is taking longer than expected, and when interventional or surgical management may be necessary. Several imaging techniques are widely available, with ultrasonography and magnetic resonance imaging currently the most frequently applied in sports medicine. This state of the art review will discuss the main imaging modalities for the assessment of sports-related muscle injuries, including advanced imaging techniques, with the focus on the clinical relevance of imaging features of muscle injuries. © RSNA, 2017 Online supplemental material is available for this article.

  9. Medical imaging displays and their use in image interpretation.

    Science.gov (United States)

    Kagadis, George C; Walz-Flannigan, Alisa; Krupinski, Elizabeth A; Nagy, Paul G; Katsanos, Konstantinos; Diamantopoulos, Athanasios; Langer, Steve G

    2013-01-01

    The adequate and repeatable performance of the image display system is a key element of information technology platforms in a modern radiology department. However, despite the wide availability of high-end computing platforms and advanced color and gray-scale monitors, the quality and properties of the final displayed medical image may often be inadequate for diagnostic purposes if the displays are not configured and maintained properly. In this article-an expanded version of the Radiological Society of North America educational module "Image Display"-the authors discuss fundamentals of image display hardware, quality control and quality assurance processes for optimal image interpretation settings, and parameters of the viewing environment that influence reader performance. Radiologists, medical physicists, and other allied professionals should strive to understand the role of display technology and proper usage for a quality radiology practice. The display settings and display quality control and quality assurance processes described in this article can help ensure high standards of perceived image quality and image interpretation accuracy.

  10. Edge enhanced morphology for infrared image analysis

    Science.gov (United States)

    Bai, Xiangzhi; Liu, Haonan

    2017-01-01

    Edge information is one of the critical information for infrared images. Morphological operators have been widely used for infrared image analysis. However, the edge information in infrared image is weak and the morphological operators could not well utilize the edge information of infrared images. To strengthen the edge information in morphological operators, the edge enhanced morphology is proposed in this paper. Firstly, the edge enhanced dilation and erosion operators are given and analyzed. Secondly, the pseudo operators which are derived from the edge enhanced dilation and erosion operators are defined. Finally, the applications for infrared image analysis are shown to verify the effectiveness of the proposed edge enhanced morphological operators. The proposed edge enhanced morphological operators are useful for the applications related to edge features, which could be extended to wide area of applications.

  11. A small animal time-resolved optical tomography platform using wide-field excitation

    Science.gov (United States)

    Venugopal, Vivek

    Small animal imaging plays a critical role in present day biomedical research by filling an important gap in the translation of research from the bench to the bedside. Optical techniques constitute an emerging imaging modality which have tremendous potential in preclinical applications. Optical imaging methods are capable of non-invasive assessment of the functional and molecular characteristics of biological tissue. The three-dimensional optical imaging technique, referred to as diffuse optical tomography, provides an approach for the whole-body imaging of small animal models and can provide volumetric maps of tissue functional parameters (e.g. blood volume, oxygen saturation etc.) and/or provide 3D localization and quantification of fluorescence-based molecular markers in vivo. However, the complex mathematical reconstruction problem associated with optical tomography and the cumbersome instrumental designs limits its adoption as a high-throughput quantitative whole-body imaging modality in current biomedical research. The development of new optical imaging paradigms is thus necessary for a wide-acceptance of this new technology. In this thesis, the design, development, characterization and optimization of a small animal optical tomography system is discussed. Specifically, the platform combines a highly sensitive time-resolved imaging paradigm with multi-spectral excitation capability and CCD-based detection to provide a system capable of generating spatially, spectrally and temporally dense measurement datasets. The acquisition of such data sets however can take long and translate to often unrealistic acquisition times when using the classical point source based excitation scheme. The novel approach in the design of this platform is the adoption of a wide-field excitation scheme which employs extended excitation sources and in the process allows an estimated ten-fold reduction in the acquisition time. The work described herein details the design of the imaging

  12. Evaluation of disturbing effect of mesh holes in wide-acceptance-angle electrostatic mesh lenses

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Hiroyuki, E-mail: hmatsuda@ms.naist.jp [Nara Institute of Science and Technology (NAIST), 8916-5 Takayama, Ikoma, Nara 630-0192 (Japan); Tóth, László [University of Debrecen, H-4032 Debrecen, Egyetemtér 1 (Hungary); Matsui, Fumihiko; Daimon, Hiroshi [Nara Institute of Science and Technology (NAIST), 8916-5 Takayama, Ikoma, Nara 630-0192 (Japan)

    2014-08-15

    Highlights: • A practical method to evaluate the disturbing effect of mesh holes in electrostatic mesh lenses is described. • The method evaluates the image blur due to a mesh hole using the Davisson–Calbick formula. • The method considers the discrepancy in focal length in tangential and saggital planes. • The method can be applied to wide-acceptance-angle electrostatic mesh lenses. • The mesh-hole effect of a wide-acceptance-angle electrostatic lens considerably decreases with increasing the emission angle. - Abstract: A curved mesh electrode introduced into an electrostatic lens enables spherical aberration correction over a wide acceptance angle. This technique has great advantages in X-ray photoelectron spectroscopy and related techniques, allowing considerable increase in photoelectron intensity and efficient measurement of photoelectron angular distribution. However, the use of meshes severely limits spatial resolution, as the image produced through each mesh hole is blurred by the lens action of the hole. This feature is studied in detail in this paper, in order to determine the best possible resolution that can be attained in electrostatic mesh lenses with wide acceptance angles. A simple way to evaluate the mesh-hole effect is to use the Davisson–Calbick formula, which expresses the focal length of a single-aperture lens. To make this approach more feasible, we take into account the influence of the angle of incidence to a mesh hole. We characterize the image blur due to each mesh hole in two orthogonal directions, considering the discrepancy in focal length in tangential and sagittal planes. After the demonstration of the validity of our approach in a simple example, the mesh-hole effect of a wide-acceptance-angle electrostatic mesh lens is evaluated.

  13. Picosecond wide-field time-correlated single photon counting fluorescence microscopy with a delay line anode detector

    Energy Technology Data Exchange (ETDEWEB)

    Hirvonen, Liisa M.; Le Marois, Alix; Suhling, Klaus, E-mail: klaus.suhling@kcl.ac.uk [Department of Physics, King' s College London, Strand, London WC2R 2LS (United Kingdom); Becker, Wolfgang; Smietana, Stefan [Becker & Hickl GmbH, Nahmitzer Damm 30, 12277 Berlin (Germany); Milnes, James; Conneely, Thomas [Photek Ltd., 26 Castleham Rd, Saint Leonards-on-Sea TN38 9NS (United Kingdom); Jagutzki, Ottmar [Institut für Kernphysik, Max-von-Laue-Str. 1, 60438 Frankfurt (Germany)

    2016-08-15

    We perform wide-field time-correlated single photon counting-based fluorescence lifetime imaging (FLIM) with a crossed delay line anode image intensifier, where the pulse propagation time yields the photon position. This microchannel plate-based detector was read out with conventional fast timing electronics and mounted on a fluorescence microscope with total internal reflection (TIR) illumination. The picosecond time resolution of this detection system combines low illumination intensity of microwatts with wide-field data collection. This is ideal for fluorescence lifetime imaging of cell membranes using TIR. We show that fluorescence lifetime images of living HeLa cells stained with membrane dye di-4-ANEPPDHQ exhibit a reduced lifetime near the coverslip in TIR compared to epifluorescence FLIM.

  14. Applied medical image processing a basic course

    CERN Document Server

    Birkfellner, Wolfgang

    2014-01-01

    A widely used, classroom-tested text, Applied Medical Image Processing: A Basic Course delivers an ideal introduction to image processing in medicine, emphasizing the clinical relevance and special requirements of the field. Avoiding excessive mathematical formalisms, the book presents key principles by implementing algorithms from scratch and using simple MATLAB®/Octave scripts with image data and illustrations on an accompanying CD-ROM or companion website. Organized as a complete textbook, it provides an overview of the physics of medical image processing and discusses image formats and data storage, intensity transforms, filtering of images and applications of the Fourier transform, three-dimensional spatial transforms, volume rendering, image registration, and tomographic reconstruction.

  15. World Wide Web voted most wonderful wonder by web-wide world

    CERN Multimedia

    2007-01-01

    The results are in, and the winner is...the World Wide Web! An online survey conducted by the CNN news group ranks the World Wide Web-invented at CERN--as the most wonderful of the seven modern wonders of the world. (See Bulletin No. 49/2006.) There is currently no speculation about whether they would have had the same results had they distributed the survey by post. The World Wide Web won with a whopping 50 per cent of the votes (3,665 votes). The runner up was CERN again, with 16 per cent of voters (1130 votes) casting the ballot in favour of the CERN particle accelerator. Stepping into place behind CERN and CERN is 'None of the Above' with 8 per cent of the votes (611 votes), followed by the development of Dubai (7%), the bionic arm (7%), China's Three Gorges Damn (5%), The Channel Tunnel (4%), and France's Millau viaduct (3%). Thanks to everyone from CERN who voted. You can view the results on http://edition.cnn.com/SPECIALS/2006/modern.wonders/

  16. Multi-modal small-animal imaging : image processing challenges and applications

    NARCIS (Netherlands)

    Khmelinskii, Artem

    2013-01-01

    In pre-clinical research, whole-body small-animal imaging is widely used for in vivo visualization of functional and anatomical information to study cancer, neurological and cardiovascular diseases and help with a faster development of new drugs. Functional information is provided by imaging

  17. Combining magnetic resonance imaging and genome-wide genetic mapping in epilepsy

    OpenAIRE

    Whelan, Christopher D.

    2015-01-01

    Recent attempts to elucidate the genetic architecture of complex epilepsies have been limited by a variety of issues including phenotypic ambiguities, small sample sizes and restricted genetic scope. This thesis employed a diverse array of genetic mapping and MRI techniques to help improve the power of genetic mapping efforts and thus our understanding of the neurobiological factors contributing towards common forms of the disorder. As part of a collaborative meta-analysis of GWAS data on ...

  18. The First Wide-field X-ray Imaging Telescope for Observations of Charge Exchange Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We will demonstrate a full, end-to-end, lobster-eye optic instrument at GSFC. The STORM prototype is fully self-contained, including integrated pre-amps, HV power...

  19. Wide-Angle Multistatic Synthetic Aperture Radar: Focused Image Formation and Aliasing Artifact Mitigation

    Science.gov (United States)

    2005-07-01

    ogive ( football -like) shape and is tipped towards the TX antenna. These two features minimize the pylon’s RCS. The pylon also contains a stepper...Figure 7.5: |χ(te, 0)| for an LFM waveform. Time mis- match error te converted to range r via r = cte /2. 208 Analytically, an SF subpulse with duration...range r via r = cte /2. more significant consequence occurs when Bτ > N2, as illustrated by the following figures. Figure 7.15 shows the frequency

  20. Image Analysis

    DEFF Research Database (Denmark)

    The 19th Scandinavian Conference on Image Analysis was held at the IT University of Copenhagen in Denmark during June 15-17, 2015. The SCIA conference series has been an ongoing biannual event for more than 30 years and over the years it has nurtured a world-class regional research and development....... The topics of the accepted papers range from novel applications of vision systems, pattern recognition, machine learning, feature extraction, segmentation, 3D vision, to medical and biomedical image analysis. The papers originate from all the Scandinavian countries and several other European countries...