Progress report on PIXIE3D, a fully implicit 3D extended MHD solver

NASA Astrophysics Data System (ADS)

Chacon, Luis

2008-11-01

Recently, invited talk at DPP07 an optimal, massively parallel implicit algorithm for 3D resistive magnetohydrodynamics (PIXIE3D) was demonstrated. Excellent algorithmic and parallel results were obtained with up to 4096 processors and 138 million unknowns. While this is a remarkable result, further developments are still needed for PIXIE3D to become a 3D extended MHD production code in general geometries. In this poster, we present an update on the status of PIXIE3D on several fronts. On the physics side, we will describe our progress towards the full Braginskii model, including: electron Hall terms, anisotropic heat conduction, and gyroviscous corrections. Algorithmically, we will discuss progress towards a robust, optimal, nonlinear solver for arbitrary geometries, including preconditioning for the new physical effects described, the implementation of a coarse processor-grid solver (to maintain optimal algorithmic performance for an arbitrarily large number of processors in massively parallel computations), and of a multiblock capability to deal with complicated geometries. L. Chac'on, Phys. Plasmas 15, 056103 (2008);

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Jian; Casey, Cameron P.; Zheng, Xueyun

Motivation: Drift tube ion mobility spectrometry (DTIMS) is increasingly implemented in high throughput omics workflows, and new informatics approaches are necessary for processing the associated data. To automatically extract arrival times for molecules measured by DTIMS coupled with mass spectrometry and compute their associated collisional cross sections (CCS) we created the PNNL Ion Mobility Cross Section Extractor (PIXiE). The primary application presented for this algorithm is the extraction of information necessary to create a reference library containing accu-rate masses, DTIMS arrival times and CCSs for use in high throughput omics analyses. Results: We demonstrate the utility of this approach bymore » automatically extracting arrival times and calculating the associated CCSs for a set of endogenous metabolites and xenobiotics. The PIXiE-generated CCS values were identical to those calculated by hand and within error of those calcu-lated using commercially available instrument vendor software.« less

Testing the Standard Model with the Primordial Inflation Explorer

NASA Technical Reports Server (NTRS)

Kogut, Alan J.

2011-01-01

The Primordial Inflation Explorer is an Explorer-class mission to measure the gravity-wave signature of primordial inflation through its distinctive imprint on the linear polarization of the cosmic microwave background. PIXIE uses an innovative optical design to achieve background-limited sensitivity in 400 spectral channels spanning 2.5 decades in frequency from 30 GHz to 6 THz (1 cm to 50 micron wavelength). The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r < 10A{-3) at 5 standard deviations. The rich PIXIE data set will also constrain physical processes ranging from Big Bang cosmology to the nature of the first stars to physical conditions within the interstellar medium of the Galaxy. I describe the PIXIE instrument and mission architecture needed to detect the inflationary signature using only 4 semiconductor bolometers.

Inflation, Reionization, and All That: The Primordial Inflation Explorer

NASA Technical Reports Server (NTRS)

Kogut, Alan J.

2011-01-01

The Primordial Inflation Explorer is an Explorer-class mission to measure the gravity-wave signature of primordial inflation through its distinctive imprint on the linear polarization of the cosmic microwave background. PIXIE uses an innovative optical design to achieve background-limited sensitivity in 400 spectral channels spanning 2.5 decades in frequency from 30 GHz to 6 THz (1 cm to 50 micron wavelength). The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r less than l0^{-3) at 5 standard deviations. The rich PIXIE data set will also constrain physical processes ranging from Big Bang cosmology to the nature of the first stars to physical conditions within the interstellar medium of the Galaxy. I describe the PIXIE instrument and mission architecture needed to detect the inflationary signature using only 4 semiconductor bolometers.

The Primordial Inflation Explorer

NASA Technical Reports Server (NTRS)

Kogut, Alan J.

2012-01-01

The Primordial Inflation Explorer is an Explorer-class mission to measure the gravity-wave signature of primordial inflation through its distinctive imprint on the linear polarization of the cosmic microwave background. PIXIE uses an innovative optical design to achieve background-limited sensitivity in 400 spectral channels spanning 2.5 decades in frequency from 30 GHz to 6 THz (1 cm to 50 micron wavelength). The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r < 10(exp -3) at 5 standard deviations. The rich PIXIE data set will also constrain physical processes ranging from Big Bang cosmology to the nature of the first stars to physical conditions within the interstellar medium of the Galaxy. I describe the PIXIE instrument and mission architecture needed to detect the inflationary signature using only 4 semiconductor bolometers.

Inflation, Reionization, and All That: The Primordial Inflation Explorer

NASA Technical Reports Server (NTRS)

Kogut, Alan J.

2012-01-01

The Primordial Inflation Explorer is an Explorer-class mission to measure the gravity-wave signature of primordial inflation through its distinctive imprint on the linear polarization of the cosmic microwave background. PIXIE uses an innovative optical design to achieve background-limited sensitivity in 400 spectral channels spanning 2.5 decades in frequency from 30 GHz to 6 THz (1 cm to 50 micron wavelength). The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r < 10(exp -3) at 5 standard deviations. The rich PIXIE data set will also constrain physical processes ranging from Big Bang cosmology to the nature of the first stars to physical conditions within the interstellar medium of the Galaxy. I describe the PIXIE instrument and mission architecture needed to detect the inflationary signature using only 4 semiconductor bolometers.

Inexpensive Audio Activities: Earbud-based Sound Experiments

NASA Astrophysics Data System (ADS)

Allen, Joshua; Boucher, Alex; Meggison, Dean; Hruby, Kate; Vesenka, James

2016-11-01

Inexpensive alternatives to a number of classic introductory physics sound laboratories are presented including interference phenomena, resonance conditions, and frequency shifts. These can be created using earbuds, economical supplies such as Giant Pixie Stix® wrappers, and free software available for PCs and mobile devices. We describe two interference laboratories (beat frequency and two-speaker interference) and two resonance laboratories (quarter- and half-wavelength). Lastly, a Doppler laboratory using rotating earbuds is explained. The audio signal captured by all experiments is analyzed on free spectral analysis software and many of the experiments incorporate the unifying theme of measuring the speed of sound in air.

Preliminary Design of the Continuous ADRs for the Primordial Inflation Explorer (PIXIE)

NASA Technical Reports Server (NTRS)

Shirron, Peter J.; Dipirro, Michael James; Fixsen, Dale J.; Kogut, Alan J.

2017-01-01

PIXIE is a recently proposed middle-class explorer mission designed to produce full-sky maps of polarization in the Cosmic Microwave Background (CMB). PIXIEs challenging science goals require not only measuring the extremely faint b-modes of the CMB, but distinguishing between true CMB signatures and 1) polarized light reflecting off local dust, and 2) signals arising from within the instrument. PIXIEs detectors will operate at 100 mK in order to achieve the required sensitivity. Instrument errors will be minimized in part by operating the telescope and optics at an average temperature close to that of the CMB (2.72 K) and systematically varying the temperature of various components by a small amount (10-20 mK). Signals appearing at the frequency of those variations can then be subtracted out. For this to be successful at the level required, it is necessary for the pattern of temperatures to be stable over very long time frames. Consequently, cooling of the detectors and telescope will be done using two 3-stage ADR assemblies that will produce continuous cooling, one at 100 mK and the other at approximately 2.65 K. The latter will act as the heat sink for 100 mK ADR and establish a base temperature from which the telescope and optics will be regulated. Its heat sink is a 4.5 K cryocooler. The design and operation of the ADRs will be discussed.

High-speed, multi-channel detector readout electronics for fast radiation detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hennig, Wolfgang

2012-06-22

In this project, we are developing a high speed digital spectrometer that a) captures detector waveforms at rates up to 500 MSPS b) has upgraded event data acquisition with additional data buffers for zero dead time operation c) moves energy calculations to the FPGA to increase spectrometer throughput in fast scintillator applications d) uses a streamlined architecture and high speed data interface for even faster readout to the host PC These features are in addition to the standard functions in our existing spectrometers such as digitization, programmable trigger and energy filters, pileup inspection, data acquisition with energy and time stamps,more » MCA histograms, and run statistics. In Phase I, we upgraded one of our existing spectrometer designs to demonstrate the key principle of fast waveform capture using a 500 MSPS, 12 bit ADC and a Xilinx Virtex-4 FPGA. This upgraded spectrometer, named P500, performed well in initial tests of energy resolution, pulse shape analysis, and timing measurements, thus achieving item (a) above. In Phase II, we are revising the P500 to build a commercial prototype with the improvements listed in items (b)-(d). As described in the previous report, two devices were built to pursue this goal, named the Pixie-500 and the Pixie-500 Express. The Pixie-500 has only minor improvements from the Phase I prototype and is intended as an early commercial product (its production and part of its development were funded outside the SBIR). It also allows testing of the ADC performance in real applications.The Pixie-500 Express (or Pixie-500e) includes all of the improvements (b)-(d). At the end of Phase II of the project, we have tested and debugged the hardware, firmware and software of the Pixie-500 Express prototype boards delivered 12/3/2010. This proved substantially more complex than anticipated. At the time of writing, all hardware bugs have been fixed, the PCI Express interface is working, the SDRAM has been successfully tested and the SHARC DSP has been booted with preliminary code. All new ICs and circuitry on the prototype are working properly, however some of the planned firmware and software functions have not yet been completely implemented and debugged. Overall, due to the unanticipated complexity of the PCI Express interface, some aspects of the project could not be completed with the time and funds available in Phase II. These aspects will be completed in self-funded Phase III.« less

Energetic Electron Transport in the Inner Magnetosphere During Geomagnetic Storms and Substorms

NASA Technical Reports Server (NTRS)

McKenzie, D. L.; Anderson, P. C.

2005-01-01

We propose to examine the relationship of geomagnetic storms and substorms and the transport of energetic particles in the inner magnetosphere using measurements of the auroral X-ray emissions by PIXIE. PIXIE provides a global view of the auroral oval for the extended periods of time required to study stormtime phenomena. Its unique energy response and global view allow separation of stormtime particle transport driven by strong magnetospheric electric fields from substorm particle transport driven by magnetic-field dipolarization and subsequent particle injection. The relative importance of substorms in releasing stored magnetospheric energy during storms and injecting particles into the inner magnetosphere and the ring current is currently hotly debated. The distribution of particles in the inner magnetosphere is often inferred from measurements of the precipitating auroral particles. Thus, the global distributions of the characteristics of energetic precipitating particles during storms and substorms are extremely important inputs to any description or model of the geospace environment and the Sun-Earth connection. We propose to use PIXIE observations and modeling of the transport of energetic electrons to examine the relationship between storms and substorms.

Helical flow in RFX-mod tokamak plasmas

NASA Astrophysics Data System (ADS)

Piron, L.; Zaniol, B.; Bonfiglio, D.; Carraro, L.; Kirk, A.; Marrelli, L.; Martin, R.; Piron, C.; Piovesan, P.; Zuin, M.

2017-05-01

This work presents the first evidence of helical flow in RFX-mod q(a)  <  2 tokamak plasmas. The flow pattern is characterized by the presence of convective cells with m  =  1 and n  =  1 periodicity in the poloidal and toroidal directions, respectively. A similar helical flow deformation has been observed in the same device when operated as a reversed field pinch (RFP). In RFP plasmas, the flow dynamic is tailored by the innermost resonant m  =  1, n  =  7 tearing mode, which sustains the magnetic field configuration through the dynamo mechanism (Bonomo et al 2011 Nucl. Fusion 51 123007). By contrast, in the tokamak experiments presented here, it is strongly correlated with the m  =  1, n  =  1 MHD activity. A helical deformation of the flow pattern, associated with the deformation of the magnetic flux surfaces, is predicted by several codes, such as Specyl (Bonfiglio et al 2005 Phys. Rev. Lett. 94 145001), PIXIE3D (Chacón et al 2008 Phys. Plasmas 15 056103), NIMROD (King et al 2012 Phys. Plasmas 19 055905) and M3D-C1 (Jardin et al 2015 Phys. Rev. Lett. 115 215001). Among them, the 3D fully non-linear PIXIE3D has been used to calculate synthetic flow measurements, using a 2D flow modelling code. Inputs to the code are the PIXIE3D flow maps, the ion emission profiles as calculated by a 1D collisional radiative impurity transport code (Carraro et al 2000 Plasma Phys. Control. Fusion 42 731) and a synthetic diagnostic with the same geometry installed in RFX-mod. Good agreement between the synthetic and the experimental flow behaviour has been obtained, confirming that the flow oscillations observed with the associated convective cells are a signature of helical flow.

Digital Data Acquisition System for experiments with segmented detectors at National Superconducting Cyclotron Laboratory

NASA Astrophysics Data System (ADS)

Starosta, K.; Vaman, C.; Miller, D.; Voss, P.; Bazin, D.; Glasmacher, T.; Crawford, H.; Mantica, P.; Tan, H.; Hennig, W.; Walby, M.; Fallu-Labruyere, A.; Harris, J.; Breus, D.; Grudberg, P.; Warburton, W. K.

2009-11-01

A 624-channel Digital Data Acquisition System capable of instrumenting the Segmented Germanium Array at National Superconducting Cyclotron Laboratory has been implemented using Pixie-16 Digital Gamma Finder modules by XIA LLC. The system opens an opportunity for determination of the first interaction position of a γ ray in a SeGA detector from implementation of γ-ray tracking. This will translate into a significantly improved determination of angle of emission, and in consequence much better Doppler corrections for experiments with fast beams. For stopped-beam experiments the system provides means for zero dead time measurements of rare decays, which occur on time scales of microseconds.

Nonlinear 3D MHD verification study: SpeCyl and PIXIE3D codes for RFP and Tokamak plasmas

NASA Astrophysics Data System (ADS)

Bonfiglio, D.; Cappello, S.; Chacon, L.

2010-11-01

A strong emphasis is presently placed in the fusion community on reaching predictive capability of computational models. An essential requirement of such endeavor is the process of assessing the mathematical correctness of computational tools, termed verification [1]. We present here a successful nonlinear cross-benchmark verification study between the 3D nonlinear MHD codes SpeCyl [2] and PIXIE3D [3]. Excellent quantitative agreement is obtained in both 2D and 3D nonlinear visco-resistive dynamics for reversed-field pinch (RFP) and tokamak configurations [4]. RFP dynamics, in particular, lends itself as an ideal non trivial test-bed for 3D nonlinear verification. Perspectives for future application of the fully-implicit parallel code PIXIE3D to RFP physics, in particular to address open issues on RFP helical self-organization, will be provided. [4pt] [1] M. Greenwald, Phys. Plasmas 17, 058101 (2010) [0pt] [2] S. Cappello and D. Biskamp, Nucl. Fusion 36, 571 (1996) [0pt] [3] L. Chac'on, Phys. Plasmas 15, 056103 (2008) [0pt] [4] D. Bonfiglio, L. Chac'on and S. Cappello, Phys. Plasmas 17 (2010)

General purpose pulse shape analysis for fast scintillators implemented in digital readout electronics

NASA Astrophysics Data System (ADS)

Asztalos, Stephen J.; Hennig, Wolfgang; Warburton, William K.

2016-01-01

Pulse shape discrimination applied to certain fast scintillators is usually performed offline. In sufficiently high-event rate environments data transfer and storage become problematic, which suggests a different analysis approach. In response, we have implemented a general purpose pulse shape analysis algorithm in the XIA Pixie-500 and Pixie-500 Express digital spectrometers. In this implementation waveforms are processed in real time, reducing the pulse characteristics to a few pulse shape analysis parameters and eliminating time-consuming waveform transfer and storage. We discuss implementation of these features, their advantages, necessary trade-offs and performance. Measurements from bench top and experimental setups using fast scintillators and XIA processors are presented.

The Primordial Inflation Explorer (PIXIE): A Nulling Polarimeter for Cosmic Microwave Background Observations

NASA Technical Reports Server (NTRS)

Kogut, Alan J.; Fixsen, D. J.; Chuss, D. T.; Dotson, J.; Dwek, E.; Halpern, M.; Hinshaw, G. F.; Meyer, S. M.; Moseley, S. H.; Seiffert, M. D.;

Nonlinear three-dimensional verification of the SPECYL and PIXIE3D magnetohydrodynamics codes for fusion plasmas

NASA Astrophysics Data System (ADS)

Bonfiglio, D.; Chacón, L.; Cappello, S.

2010-08-01

With the increasing impact of scientific discovery via advanced computation, there is presently a strong emphasis on ensuring the mathematical correctness of computational simulation tools. Such endeavor, termed verification, is now at the center of most serious code development efforts. In this study, we address a cross-benchmark nonlinear verification study between two three-dimensional magnetohydrodynamics (3D MHD) codes for fluid modeling of fusion plasmas, SPECYL [S. Cappello and D. Biskamp, Nucl. Fusion 36, 571 (1996)] and PIXIE3D [L. Chacón, Phys. Plasmas 15, 056103 (2008)], in their common limit of application: the simple viscoresistive cylindrical approximation. SPECYL is a serial code in cylindrical geometry that features a spectral formulation in space and a semi-implicit temporal advance, and has been used extensively to date for reversed-field pinch studies. PIXIE3D is a massively parallel code in arbitrary curvilinear geometry that features a conservative, solenoidal finite-volume discretization in space, and a fully implicit temporal advance. The present study is, in our view, a first mandatory step in assessing the potential of any numerical 3D MHD code for fluid modeling of fusion plasmas. Excellent agreement is demonstrated over a wide range of parameters for several fusion-relevant cases in both two- and three-dimensional geometries.

Nonlinear three-dimensional verification of the SPECYL and PIXIE3D magnetohydrodynamics codes for fusion plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bonfiglio, Daniele; Chacon, Luis; Cappello, Susanna

2010-01-01

With the increasing impact of scientific discovery via advanced computation, there is presently a strong emphasis on ensuring the mathematical correctness of computational simulation tools. Such endeavor, termed verification, is now at the center of most serious code development efforts. In this study, we address a cross-benchmark nonlinear verification study between two three-dimensional magnetohydrodynamics (3D MHD) codes for fluid modeling of fusion plasmas, SPECYL [S. Cappello and D. Biskamp, Nucl. Fusion 36, 571 (1996)] and PIXIE3D [L. Chacon, Phys. Plasmas 15, 056103 (2008)], in their common limit of application: the simple viscoresistive cylindrical approximation. SPECYL is a serial code inmore » cylindrical geometry that features a spectral formulation in space and a semi-implicit temporal advance, and has been used extensively to date for reversed-field pinch studies. PIXIE3D is a massively parallel code in arbitrary curvilinear geometry that features a conservative, solenoidal finite-volume discretization in space, and a fully implicit temporal advance. The present study is, in our view, a first mandatory step in assessing the potential of any numerical 3D MHD code for fluid modeling of fusion plasmas. Excellent agreement is demonstrated over a wide range of parameters for several fusion-relevant cases in both two- and three-dimensional geometries.« less

Design of the PIXIE Adiabatic Demagnetization Refrigerators

NASA Technical Reports Server (NTRS)

Shirron, Peter J.; Kimball, Mark Oliver; Fixsen, Dale J.; Kogut, Alan J.; Li, Xiaoyi; DiPirro, Michael

2012-01-01

The Primordial Inflation Explorer (PIXIE) is a proposed mission to densely map the polarization of the cosmic microwave background. It will operate in a scanning mode from a sun-synchronous orbit, using low temperature detectors (at 0.1 K) and located inside a teslescope that is cooled to approximately 2.73 K - to match the background temperature. A mechanical cryocooler operating at 4.5 K establishes a low base temperature from which two adiabatic demagnetization refrigerator (ADR) assemblies will cool the telescope and detectors. To achieve continuous scanning capability, the ADRs must operate continuously. Complicating the design are two factors: 1) the need to systematically vary the temperature of various telescope components in order to separate the small polarization signal variations from those that may arise from temperature drifts and changing gradients within the telescope, and 2) the orbital and monthly variations in lunar irradiance into the telescope barrels. These factors require the telescope ADR to reject quasi-continuous heat loads of 2-3 millwatts, while maintaining a peak heat reject rate of less than 12 milliwatts. The detector heat load at 0.1 K is comparatively small at 1-2 microwatts. This paper will describe the 3-stage and 2-stage continuous ADRs that will be used to meet the cooling power and temperature stability requirements of the PIXIE detectors and telescope.

Prospects for measuring cosmic microwave background spectral distortions in the presence of foregrounds

NASA Astrophysics Data System (ADS)

Abitbol, Maximilian H.; Chluba, Jens; Hill, J. Colin; Johnson, Bradley R.

2017-10-01

Measurements of cosmic microwave background (CMB) spectral distortions have profound implications for our understanding of physical processes taking place over a vast window in cosmological history. Foreground contamination is unavoidable in such measurements and detailed signal-foreground separation will be necessary to extract cosmological science. In this paper, we present Markov chain Monte Carlo based spectral distortion detection forecasts in the presence of Galactic and extragalactic foregrounds for a range of possible experimental configurations, focusing on the Primordial Inflation Explorer (PIXIE) as a fiducial concept. We consider modifications to the baseline PIXIE mission (operating ≃ 12 months in distortion mode), searching for optimal configurations using a Fisher approach. Using only spectral information, we forecast an extended PIXIE mission to detect the expected average non-relativistic and relativistic thermal Sunyaev-Zeldovich distortions at high significance (194σ and 11σ, respectively), even in the presence of foregrounds. The ΛCDM Silk damping μ-type distortion is not detected without additional modifications of the instrument or external data. Galactic synchrotron radiation is the most problematic source of contamination in this respect, an issue that could be mitigated by combining PIXIE data with future ground-based observations at low frequencies (ν ≲ 15-30 GHz). Assuming moderate external information on the synchrotron spectrum, we project an upper limit of |μ| < 3.6 × 10-7 (95 per cent c.l.), slightly more than one order of magnitude above the fiducial ΛCDM signal from the damping of small-scale primordial fluctuations, but a factor of ≃250 improvement over the current upper limit from COBE/Far Infrared Absolute Spectrophotometer. This limit could be further reduced to |μ| < 9.4 × 10-8 (95 per cent c.l.) with more optimistic assumptions about extra low-frequency information and would rule out many alternative inflation models and provide new constraints on decaying particle scenarios.

Comparison of a CCD and an APS for soft X-ray diffraction

NASA Astrophysics Data System (ADS)

Stewart, Graeme; Bates, R.; Blue, A.; Clark, A.; Dhesi, S. S.; Maneuski, D.; Marchal, J.; Steadman, P.; Tartoni, N.; Turchetta, R.

2011-12-01

We compare a new CMOS Active Pixel Sensor (APS) to a Princeton Instruments PIXIS-XO: 2048B Charge Coupled Device (CCD) with soft X-rays tested in a synchrotron beam line at the Diamond Light Source (DLS). Despite CCDs being established in the field of scientific imaging, APS are an innovative technology that offers advantages over CCDs. These include faster readout, higher operational temperature, in-pixel electronics for advanced image processing and reduced manufacturing cost. The APS employed was the Vanilla sensor designed by the MI3 collaboration and funded by an RCUK Basic technology grant. This sensor has 520 x 520 square pixels, of size 25 μm on each side. The sensor can operate at a full frame readout of up to 20 Hz. The sensor had been back-thinned, to the epitaxial layer. This was the first time that a back-thinned APS had been demonstrated at a beam line at DLS. In the synchrotron experiment soft X-rays with an energy of approximately 708 eV were used to produce a diffraction pattern from a permalloy sample. The pattern was imaged at a range of integration times with both sensors. The CCD had to be operated at a temperature of -55°C whereas the Vanilla was operated over a temperature range from 20°C to -10°C. We show that the APS detector can operate with frame rates up to two hundred times faster than the CCD, without excessive degradation of image quality. The signal to noise of the APS is shown to be the same as that of the CCD at identical integration times and the response is shown to be linear, with no charge blooming effects. The experiment has allowed a direct comparison of back thinned APS and CCDs in a real soft x-ray synchrotron experiment.

Characterisation of Redlen high-flux CdZnTe

NASA Astrophysics Data System (ADS)

Thomas, B.; Veale, M. C.; Wilson, M. D.; Seller, P.; Schneider, A.; Iniewski, K.

2017-12-01

CdZnTe is a promising material for the current generation of free electron laser light sources and future laser-driven γ-ray sources which require detectors capable of high flux imaging at X-ray and γ-ray energies (> 10 keV) . However, at high fluxes CdZnTe has been shown to polarise due to hole trapping, leading to poor performance. Novel Redlen CdZnTe material with improved hole transport properties has been designed for high flux applications. Small pixel CdZnTe detectors were fabricated by Redlen Technologies and flip-chip bonded to PIXIE ASICs. An XIA Digital Gamma Finder PIXIE-16 system was used to digitise each of the nine analogue signals with a timing resolution of 10 ns. Pulse shape analysis was used to extract the rise times and amplitude of signals. These were measured as a function of applied bias voltage and used to calculate the mobility (μ) and mobility-lifetime (μτ) of electrons and holes in the material for three identical detectors. The measured values of the transport properties of electrons in the high-flux-capable material was lower than previously reported for Redlen CdZnTe material (μeτe ~ 1 × 10-3 cm2V-1 and μe ~ 1000 cm2V-1s-1) while the hole transport properties were found to have improved (μhτh ~ 3 × 10-4 cm2V-1 and μh ~ 100 cm2V-1s-1).

Energetic Electron Populations in the Magnetosphere During Geomagnetic Storms and Substorms

NASA Technical Reports Server (NTRS)

McKenzie, David L.; Anderson, Phillip C.

2002-01-01

This report summarizes the scientific work performed by the Aerospace Corporation under NASA Grant NAG5-10278, 'Energetic Electron Populations in the Magnetosphere during Geomagnetic Storms and Subsisting.' The period of performance for the Grant was March 1, 2001 to February 28, 2002. The following is a summary of the Statement of Work for this Grant. Use data from the PIXIE instrument on the Polar spacecraft from September 1998 onward to derive the statistical relationship between particle precipitation patterns and various geomagnetic activity indices. We are particularly interested in the occurrence of substorms during storm main phase and the efficacy of storms and substorms in injecting ring-current particles. We will compare stormtime simulations of the diffuse aurora using the models of Chen and Schulz with stormtime PIXIE measurements.

Taking the Universe's Temperature with Spectral Distortions of the Cosmic Microwave Background.

PubMed

Hill, J Colin; Battaglia, Nick; Chluba, Jens; Ferraro, Simone; Schaan, Emmanuel; Spergel, David N

2015-12-31

The cosmic microwave background (CMB) energy spectrum is a near-perfect blackbody. The standard model of cosmology predicts small spectral distortions to this form, but no such distortion of the sky-averaged CMB spectrum has yet been measured. We calculate the largest expected distortion, which arises from the inverse Compton scattering of CMB photons off hot, free electrons, known as the thermal Sunyaev-Zel'dovich (TSZ) effect. We show that the predicted signal is roughly one order of magnitude below the current bound from the COBE-FIRAS experiment, but it can be detected at enormous significance (≳1000σ) by the proposed Primordial Inflation Explorer (PIXIE). Although cosmic variance reduces the effective signal-to-noise ratio to 230σ, this measurement will still yield a subpercent constraint on the total thermal energy of electrons in the observable Universe. Furthermore, we show that PIXIE can detect subtle relativistic effects in the sky-averaged TSZ signal at 30σ, which directly probe moments of the optical depth-weighted intracluster medium electron temperature distribution. These effects break the degeneracy between the electron density and the temperature in the mean TSZ signal, allowing a direct inference of the mean baryon density at low redshift. Future spectral distortion probes will thus determine the global thermodynamic properties of ionized gas in the Universe with unprecedented precision. These measurements will impose a fundamental "integral constraint" on models of galaxy formation and the injection of feedback energy over cosmic time.

A photo-cross-linking approach to monitor folding and assembly of newly synthesized proteins in a living cell.

PubMed

Miyazaki, Ryoji; Myougo, Naomi; Mori, Hiroyuki; Akiyama, Yoshinori

2018-01-12

Many proteins form multimeric complexes that play crucial roles in various cellular processes. Studying how proteins are correctly folded and assembled into such complexes in a living cell is important for understanding the physiological roles and the qualitative and quantitative regulation of the complex. However, few methods are suitable for analyzing these rapidly occurring processes. Site-directed in vivo photo-cross-linking is an elegant technique that enables analysis of protein-protein interactions in living cells with high spatial resolution. However, the conventional site-directed in vivo photo-cross-linking method is unsuitable for analyzing dynamic processes. Here, by combining an improved site-directed in vivo photo-cross-linking technique with a pulse-chase approach, we developed a new method that can analyze the folding and assembly of a newly synthesized protein with high spatiotemporal resolution. We demonstrate that this method, named the pulse-chase and in vivo photo-cross-linking experiment (PiXie), enables the kinetic analysis of the formation of an Escherichia coli periplasmic (soluble) protein complex (PhoA). We also used our new technique to investigate assembly/folding processes of two membrane complexes (SecD-SecF in the inner membrane and LptD-LptE in the outer membrane), which provided new insights into the biogenesis of these complexes. Our PiXie method permits analysis of the dynamic behavior of various proteins and enables examination of protein-protein interactions at the level of individual amino acid residues. We anticipate that our new technique will have valuable utility for studies of protein dynamics in many organisms. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

SOURCE APPORTIONMENT OF PM2.5 IN SEATTLE, WA URBAN IMPROVE SITE: COMPARISON OF THREE RECEPTOR MODELS AND SOURCE PROFILES

EPA Science Inventory

IMPROVE protocol data were collected at the urban Beacon Hill monitoring site in Seattle, WA from 1996-99. The 289 sets of PM2.5 filters were analyzed for: metals using PIXIE and XRF, anions using ion chromatography, elemental hydrogen (H) by proton scattering, and elemental an...

Pixie-Dust and Privacy: What's Happening to Children's Rights in England?

ERIC Educational Resources Information Center

Dowty, Terri

2008-01-01

Increasingly, Information Technology is being used to identify, record and track children in England under the banners of child protection, reducing risk and improving outcomes. Discussions about the importance of a child's right to privacy have been sidelined in the rush to embrace systems that seek to expand the amount and types of information…

Uses and Potentials of Wikis in the Classroom

ERIC Educational Resources Information Center

Ferris, S. Pixy; Wilder, Hilary

2006-01-01

S. Pixy Ferris and Hilary Wilder discuss the changes that are occurring in teaching and learning in a world where teachers and students are increasingly products of two different learning cultures. Adopting the linguistic theory of Walter J. Ong, they see teachers as part of a print paradigm of learning whereas they propose that students are…

Motion induced second order temperature and y-type anisotropies after the subtraction of linear dipole in the CMB maps

NASA Astrophysics Data System (ADS)

Sunyaev, Rashid A.; Khatri, Rishi

2013-03-01

y-type spectral distortions of the cosmic microwave background allow us to detect clusters and groups of galaxies, filaments of hot gas and the non-uniformities in the warm hot intergalactic medium. Several CMB experiments (on small areas of sky) and theoretical groups (for full sky) have recently published y-type distortion maps. We propose to search for two artificial hot spots in such y-type maps resulting from the incomplete subtraction of the effect of the motion induced dipole on the cosmic microwave background sky. This dipole introduces, at second order, additional temperature and y-distortion anisotropy on the sky of amplitude few μK which could potentially be measured by Planck HFI and Pixie experiments and can be used as a source of cross channel calibration by CMB experiments. This y-type distortion is present in every pixel and is not the result of averaging the whole sky. This distortion, calculated exactly from the known linear dipole, can be subtracted from the final y-type maps, if desired.

Motion induced second order temperature and y-type anisotropies after the subtraction of linear dipole in the CMB maps

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sunyaev, Rashid A.; Khatri, Rishi, E-mail: sunyaev@mpa-garching.mpg.de, E-mail: khatri@mpa-garching.mpg.de

2013-03-01

y-type spectral distortions of the cosmic microwave background allow us to detect clusters and groups of galaxies, filaments of hot gas and the non-uniformities in the warm hot intergalactic medium. Several CMB experiments (on small areas of sky) and theoretical groups (for full sky) have recently published y-type distortion maps. We propose to search for two artificial hot spots in such y-type maps resulting from the incomplete subtraction of the effect of the motion induced dipole on the cosmic microwave background sky. This dipole introduces, at second order, additional temperature and y-distortion anisotropy on the sky of amplitude few μKmore » which could potentially be measured by Planck HFI and Pixie experiments and can be used as a source of cross channel calibration by CMB experiments. This y-type distortion is present in every pixel and is not the result of averaging the whole sky. This distortion, calculated exactly from the known linear dipole, can be subtracted from the final y-type maps, if desired.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dimastrogiovanni, Emanuela; Emami, Razieh, E-mail: emanuela1573@gmail.com, E-mail: iasraziehm@ust.hk

Probing correlations among short and long-wavelength cosmological fluctuations is known to be decisive for deepening the current understanding of inflation at the microphysical level. Spectral distortions of the CMB can be caused by dissipation of cosmological perturbations when they re-enter Hubble after inflation. Correlating spectral distortions with temperature anisotropies will thus provide the opportunity to greatly enlarge the range of scales over which squeezed limits can be tested, opening up a new window on inflation complementing the ones currently probed with CMB and LSS. In this paper we discuss a variety of inflationary mechanisms that can be efficiently constrained withmore » distortion-temperature correlations. For some of these realizations (representative of large classes of models) we derive quantitative predictions for the squeezed limit bispectra, finding that their amplitudes are above the sensitivity limits of an experiment such as the proposed PIXIE.« less

The Fairy Who Wouldn't Fly: A Story of Subjection and Agency

ERIC Educational Resources Information Center

Davies, Bronwyn

2005-01-01

This article examines the discursive shifts in the story "The Fairy Who Wouldn't Fly," written and illustrated by Pixie O'Harris in 1945 and then retold by David Harris in 1974. The article examines the changes between the 1940s and the 1970s in the broader social world, in particular the ways the correction of children (or bringing children into…

Field-Programmable Gate Array (FPGA) Emulation for Computer Architecture

DTIC Science & Technology

2009-08-01

Execution with Versatile, Microarchitecture-Independent Snapshots, PhD thesis, MIT, Sep 2006. [10] Bienia, Christian, Kumar , Sanjeev, Singh , Jaswinder Pal...2] Pixie: MIPS Computer Systems, Inc. Assembly Language Programmer’s Guide, 1986. [3] Agarwal, Anant , Bianchini, Ricardo, Chaiken, David, David...pp. 68–79. [49] Woo, Steven Cameron, Ohara, Moriyoshi, Torrie, Evan, Singh , Jaswinder Pal, and Gupta, Anoop, “The SPLASH-2 programs

Constraints on hidden photons from current and future observations of CMB spectral distortions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kunze, Kerstin E.; Vázquez-Mozo, Miguel Á., E-mail: kkunze@usal.es, E-mail: Miguel.Vazquez-Mozo@cern.ch

2015-12-01

A variety of beyond the standard model scenarios contain very light hidden sector U(1) gauge bosons undergoing kinetic mixing with the photon. The resulting oscillation between ordinary and hidden photons leads to spectral distortions of the cosmic microwave background. We update the bounds on the mixing parameter χ{sub 0} and the mass of the hidden photon m{sub γ'} for future experiments measuring CMB spectral distortions, such as PIXIE and PRISM/COrE. For 10{sup −14} eV∼< m{sub γ'}∼< 10{sup −13} eV, we find the kinetic mixing angle χ{sub 0} has to be less than 10{sup −8} at 95% CL. These bounds are more than an ordermore » of magnitude stronger than those derived from the COBE/FIRAS data.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anthonisen, Madeleine; Brandenberger, Robert; Laguë, Alex

Cosmic string loops contain cusps which decay by emitting bursts of particles. A significant fraction of the released energy is in the form of photons. These photons are injected non-thermally and can hence cause spectral distortions of the Cosmic Microwave Background (CMB). Under the assumption that cusps are robust against gravitational back-reaction, we compute the fractional energy density released as photons in the redshift interval where such non-thermal photon injection causes CMB spectral distortions. Whereas current constraints on such spectral distortions are not strong enough to constrain the string tension, future missions such as the PIXIE experiment will be ablemore » to provide limits which rule out a range of string tensions between G μ ∼ 10{sup −15} and G μ ∼ 10{sup −12}, thus ruling out particle physics models yielding these kind of intermediate-scale cosmic strings.« less

Design and Optimization of a Dual-HPGe Gamma Spectrometer and Its Cosmic Veto System

NASA Astrophysics Data System (ADS)

Zhang, Weihua; Ro, Hyunje; Liu, Chuanlei; Hoffman, Ian; Ungar, Kurt

2017-03-01

In this paper, a dual high purity germanium (HPGe) gamma spectrometer detection system with an increased solid angle was developed. The detection system consists of a pair of Broad Energy Germanium (BE-5030p) detectors and an XIA LLC digital gamma finder/Pixie-4 data-acquisition system. A data file processor was developed containing five modules that parses Pixie-4 list-mode data output files and classifies detections into anticoincident/coincident events and their specific coincidence types (double/triple/quadruple) for further analysis. A novel cosmic veto system was installed in the detection system. It was designed to be easy to install around an existing system while still providing sufficient cosmic veto shielding comparable to other designs. This paper describes the coverage and efficiency of this cosmic veto and the data processing system. It has been demonstrated that the cosmic veto system can provide a mean background reduction of 66.1%, which results in a mean MDA improvement of 58.3%. The counting time to meet the required MDA for specific radionuclide can be reduced by a factor of 2-3 compared to those using a conventional HPGe system. This paper also provides an initial overview of coincidence timing distributions between an incoming event from a cosmic veto plate and HPGe detector.

Dealing with Beam Structure in PIXIE

NASA Technical Reports Server (NTRS)

Fixsen, D. J.; Kogut, Alan; Hill, Robert S.; Nagler, Peter C.; Seals, Lenward T., III; Howard, Joseph M.

2016-01-01

Measuring the B-mode polarization of the CMB radiation requires a detailed understanding of the projection of the detector onto the sky. We show how the combination of scan strategy and processing generates a cylindrical beam for the spectrum measurement. Both the instrumental design and the scan strategy reduce the cross coupling between the temperature variations and the B-modes. As with other polarization measurements some post processing may be required to eliminate residual errors.

Ex-vivo expansion of CFU-GM and BFU-E in unselected PBMC cultures with Flt3L is enhanced by autologous plasma.

PubMed

Guo, M; Miller, W M; Papoutsakis, E T; Patel, S; James, C; Goolsby, C; Winter, J N

1999-01-01

Previous ex-vivo expansion studies in our laboratory, comparing unselected and CD34(+)-selected PBMC, have shown no advantage for CD34(+) cell selection, in terms of the expansion achieved. Our goal was to develop procedures for consistent generation of large numbers of hematopoietic progenitor and post-progenitor cells from unselected PBMC. Unselected PBMC, collected from cancer patients undergoing apheresis prior to high-dose chemotherapy and autologous stem cell rescue, were expanded ex vivo in static cultures, without a stromal layer, in the presence of Flt3 ligand (Flt3L), a recombinant GM-CSF/IL-3 fusion protein (PIXY321), G-CSF and GM-CSF for 10 days. The addition of 2% autologous plasma to this cytokine combination enhanced expansion of total cell numbers (3.2 fold versus 1.9 fold; p < 0.01), colony-forming units granulocyte-macrophage (CFU-GM) (22.0 fold versus 8.1 fold, p < 0.01) and burst-forming units erythroid (BFU-E) (17.6 fold versus 7.0 fold, 0.01 < p < 0.02). The optimal seeding density for a given specimen was inversely related to the frequency of CD34(+) cells in the sample. CFU-GM expansion with the Flt3L-containing cytokine cocktail was equivalent to that obtained with IL-3, IL-6, G-CSF and SCF, whether or not the cultures were supplemented with autologous plasma. In plasma-free cultures, BFU-E expansion was significantly higher with IL-3, IL-6, G-CSF and SCF than with Flt3L, PIXY321, G-CSF and GM-CSF. In the presence of autologous plasma, however BFU-E expansion was higher in the Flt3L-containing media. In comparison studies, autologous plasma suppressed BFU-E expansion in SCF-containing cultures. Consistent with our colony assay results, dual-parameter flow cytometric analysis of the expanded cell population revealed that supplementation with autologous plasma yielded a significant increase in the numbers of myeloid progenitors in Flt3L-containing cultures. Unselected PBMC from cancer patients can be effectively expanded ex vivo in Flt3L, PIXY321, G-CSF and GM-CSF, supplemented with autologous plasma, yielding high numbers of myeloid and erythroid progenitors.

Limits on the fluctuating part of y-type distortion monopole from Planck and SPT results

NASA Astrophysics Data System (ADS)

Khatri, Rishi; Sunyaev, Rashid

2015-08-01

We use the published Planck and SPT cluster catalogs [1,2] and recently published y-distortion maps [3] to put strong observational limits on the contribution of the fluctuating part of the y-type distortions to the y-distortion monopole. Our bounds are 5.4× 10-8 < langle yrangle < 2.2× 10-6. Our upper bound is a factor of 6.8 stronger than the currently best upper 95% confidence limit from COBE-FIRAS of langle yrangle <15× 10-6. In the standard cosmology, large scale structure is the only source of such distortions and our limits therefore constrain the baryonic physics involved in the formation of the large scale structure. Our lower limit, from the detected clusters in the Planck and SPT catalogs, also implies that a Pixie-like experiment should detect the y-distortion monopole at >27-σ. The biggest sources of uncertainty in our upper limit are the monopole offsets between different HFI channel maps that we estimate to be <10-6.

VizieR Online Data Catalog: BVR light curves of UZ Leo (Lee+, 2018)

NASA Astrophysics Data System (ADS)

Lee, J. W.; Park, J.-H.

2018-04-01

We performed new CCD photometry of UZ Leo during two observing seasons between 2012 February and 2013 April, using a PIXIS: 2048B CCD and a BVR filter set attached to the 61 cm reflector at Sobaeksan Optical Astronomy Observatory (SOAO) in Korea. The CCD chip has 2048x2048pixels and a pixel size of 13.5um, so the field of view of a CCD frame is 17.6'x17.6'. (1 data file).

Precipitating auroral electrons and lower thermospheric nitric oxide densities: SNOE, POLAR, SAMPEX, and NOAA/POES Comparisons for Geomagnetic Storms in 1998-2001

NASA Astrophysics Data System (ADS)

Baker, D. N.; Fisher, T. A.; Barth, C. A.; Mankoff, K. D.; Kanekal, S. G.; Bailey, S. M.; Petrinec, S. M.; Luhmann, J. G.; Mason, G. M.; Mazur, J. E.; Evans, D. S.

2002-05-01

Nitric oxide (NO) densities measured at altitudes between 97 and 150 km have been acquired using the UVS sensor onboard the Student Nitric Oxide Explorer (SNOE) spacecraft during the years 1998-2001. These data are compared with energetic electron fluxes (E>25 keV) measured concurrently using a sensitive sensor system (LICA) onboard the Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX) spacecraft. Geomagnetic storm intervals are examined to determine altitude and latitude variations of NO density as it compares to energetic electron precipitation. A broader statistical analysis is then carried out using daily averages of peak NO densities (at 106 km altitudes) and electron intensities measured by SAMPEX/LICA and by the TED sensor system onboard the NOAA/Polar Orbiting Environmental Satellite (POES) spacecraft. We also use the PIXIE instrument onboard POLAR to obtain global views of 2-12 keV x-rays emanating from the upper atmosphere. This gives a broad synoptic measure of relatively low-energy electron precipitation into the atmosphere. Latitude versus time displays of the UVS, PIXIE, LICA and TED data show excellent temporal and spatial correlations of the data sets. More detailed comparisons help us to assess spectral and local time relationships between auroral particle inputs and lower thermospheric chemical responses. These results are potentially quite important since past modeling has shown that particle inputs are significant for changing the chemistry and subsequent dynamics of the atmosphere.

Sawtooth mitigation in 3D MHD tokamak modelling with applied magnetic perturbations

NASA Astrophysics Data System (ADS)

Bonfiglio, D.; Veranda, M.; Cappello, S.; Chacón, L.; Escande, D. F.

2017-01-01

The effect of magnetic perturbations (MPs) on the sawtoothing dynamics of the internal kink mode in the tokamak is discussed in the framework of nonlinear 3D MHD modelling. Numerical simulations are performed with the pixie3d code (Chacón 2008 Phys. Plasmas 15 056103) based on a D-shaped configuration in toroidal geometry. MPs are applied as produced by two sets of coils distributed along the toroidal direction, one set located above and the other set below the outboard midplane, like in experimental devices such as DIII-D and ASDEX Upgrade. The capability of n  =  1 MPs to affect quasi-periodic sawteeth is shown to depend on the toroidal phase difference Δ φ between the perturbations produced by the two sets of coils. In particular, sawtooth mitigation is obtained for the Δ φ =π phasing, whereas no significant effect is observed for Δ φ =0 . Numerical findings are explained by the interplay between different poloidal harmonics in the spectrum of applied MPs, and appear to be consistent with experiments performed in the DIII-D device. Sawtooth mitigation and stimulation of self-organized helical states by applied MPs have been previously demonstrated in both circular tokamak and reversed-field pinch (RFP) experiments in the RFX-mod device, and in related 3D MHD modelling.

CMB spectral distortion constraints on thermal inflation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cho, Kihyun; Stewart, Ewan D.; Hong, Sungwook E.

2017-08-01

Thermal inflation is a second epoch of exponential expansion at typical energy scales V {sup 1/4} ∼ 10{sup 6} {sup ∼} {sup 8} GeV. If the usual primordial inflation is followed by thermal inflation, the primordial power spectrum is only modestly redshifted on large scales, but strongly suppressed on scales smaller than the horizon size at the beginning of thermal inflation, k > k {sub b} = a {sub b} H {sub b}. We calculate the spectral distortion of the cosmic microwave background generated by the dissipation of acoustic waves in this context. For k {sub b} || 10{sup 3}more » Mpc{sup −1}, thermal inflation results in a large suppression of the μ-distortion amplitude, predicting that it falls well below the standard value of μ ≅ 2× 10{sup −8}. Thus, future spectral distortion experiments, similar to PIXIE, can place new limits on the thermal inflation scenario, constraining k {sub b} ∼> 10{sup 3} Mpc{sup −1} if μ ≅ 2× 10{sup −8} were found.« less

Polarizing beam-splitter rotation in Martin-Puplett interferometers for spectroscopic measurements at millimeter wavelengths

NASA Astrophysics Data System (ADS)

D'Alessandro, Giuseppe; de Bernardis, Paolo; di Tano, Silvio; Masi, Silvia; Mele, Lorenzo

2017-09-01

The spectroscopic measurement of the Cosmic Microwave Background at mm and sub-mm wavelengths received significant attention recently, aimed at measuring tiny spectral distortions of the Cosmic Microwave Background (CMB) relevant for cosmology. Several experiments, including OLIMPO (Masi et al. 2003), PRISM (André et al., 2014), MILLIMETRON (Smirnov and Baryshev, 2012), PIXIE (Kogut and Fixsen, 2011) are based on a Martin-Puplett Fourier-transform spectrometer. Its differential capabilities are the key to success in these difficult measurements. The polarizing beam splitter is the optical core of a Martin-Puplett interferometer. In this paper we analyze, analytically and experimentally, the systematic effects induced by a beam splitter orientation different from the canonical 45 ° . These effects are potenitally important for the delicate measurements of CMB spectral distortions. We find an analytical formula describing the effect, and verify experimentally, in the range 150-600 GHz, that our formula correctly describes the results (with a C.L. of 88 %). We also demonstrate that the rotation of the beam splitter does not induce distortions in the measured spectra.

Interaction of external n = 1 magnetic fields with the sawtooth instability in low- q RFX-mod and DIII-D tokamaks

DOE PAGES

Piron, C.; Martin, P.; Bonfiglio, D.; ...

2016-08-11

External n = 1 magnetic fields are applied in RFX-mod and DIII-D low safety factor Tokamak plasmas to investigate their interaction with the internal MHD dynamics and in particular with the sawtooth instability. In these experiments the applied magnetic fields cause a reduction of both the sawtooth amplitude and period, leading to an overall stabilizing effect on the oscillations. In RFX-mod sawteeth eventually disappear and are replaced by a stationary m = 1, n = 1 helical equilibrium without an increase in disruptivity. However toroidal rotation is significantly reduced in these plasmas, thus it is likely that the sawtooth mitigationmore » in these experiments is due to the combination of the helically deformed core and the reduced rotation. The former effect is qualitatively well reproduced by nonlinear MHD simulations performed with the PIXIE3D code. The results obtained in these RFX-mod experiments motivated similar ones in DIII-D L-mode diverted Tokamak plasmas at low q 95. These experiments succeeded in reproducing the sawtooth mitigation with the approach developed in RFX-mod. In DIII-D this effect is correlated with a clear increase of the n = 1 plasma response, that indicates an enhancement of the coupling to the marginally stable n = 1 external kink, as simulations with the linear MHD code IPEC suggest. A significant rotation braking in the plasma core is also observed in DIII-D. Finally, numerical calculations of the neoclassical toroidal viscosity (NTV) carried out with PENT identify this torque as a possible contributor for this effect.« less

Supraoptimal carbon dioxide effects on growth of soybean [Glycine max (L.) Merr.

NASA Technical Reports Server (NTRS)

Wheeler, R. M.; Mackowiak, C. L.; Siegriest, L. M.; Sager, J. C.; Knott, W. M. (Principal Investigator)

1993-01-01

In tightly closed environments used for human life support in space, carbon dioxide (CO2) partial pressures can reach 500 to 1000 Pa, which may be supraoptimal or toxic to plants used for life support. To study this, soybeans [Glycine max (L.) Merr. cvs. McCall and Pixie] were grown for 90 days at 50, 100, 200, and 500 Pa partial pressure CO2 (500, 1000, 2000, and 5000 ppm). Plants were grown using recirculating nutrient film technique with a 12-h photoperiod, a 26 degrees C/20 degrees C thermoperiod, and approximately 300 micromoles m-2 s-1 photosynthetic photon flux (PPF). Seed yield and total biomass were greatest at 100 Pa for cv. McCall, suggesting that higher CO2 levels were supraoptimal. Seed yield and total biomass for cv. Pixie showed little difference between CO2 treatments. Average stomatal conductance of upper canopy leaves at 50 Pa CO2 approximately 500 Pa > 200 Pa > 100 Pa. Total water use over 90 d for both cultivars (combined on one recirculating system) equalled 822 kg water for 100 Pa CO2, 845 kg for 50 Pa, 879 kg for 200 Pa, and 1194 kg for 500 Pa. Water use efficiences for both cultivars combined equalled 3.03 (g biomass kg-1 water) for 100 Pa CO2, 2.54 g kg-1 for 200 Pa, 2.42 g kg-1 for 50 Pa, and 1.91 g kg-1 for 500 Pa. The increased stomatal conductance and stand water use at the highest CO2 level (500 Pa) were unexpected and pose interesting considerations for managing plants in a tightly closed system where CO2 concentrations may reach high levels.

Poster - 33: Dosimetry Comparison of Prone Breast Forward and Inverse Treatment planning considering daily setup variations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, Runqing; Zhan, Lixin; Osei, Ernest

2016-08-15

Introduction: The purpose of this study is to investigate the effects of daily setup variations on prone breast forward field-in-field (FinF) and inverse IMRT treatment planning. Methods: Rando Phantom (Left breast) and Pixy phantom (Right breast) were built and CT scanned in prone position. The treatment planning (TP) is performed in Eclipse TP system. Forward FinF plan and inverse IMRT plan were created to satisfy the CTV coverage and OARs criteria. The daily setup variations were assumed to be 5 mm at left-right, superior-inferior, and anterior-posterior directions. The DVHs of CTV coverage and OARs were compared for both forward FinFmore » plan and inverse IMRT plans due to 5mm setup variation. Results and Discussions: DVHs of CTV coverage had fewer variations for 5m setup variation for forward FinF and inverse IMRT plan for both phantoms. However, for the setup variations in the left-right direction, the DVH of CTV coverage of IMRT plan showed the worst variation due to lateral setup variation for both phantoms. For anterior-posterior variation, the CTV could not get full coverage when the breast chest wall is shallow; however, with the guidance of MV imaging, breast chest wall will be checked during the MV imaging setup. So the setup variations have more effects on inverse IMRT plan, compared to forward FinF plan, especially in the left-right direction. Conclusions: The Forward FinF plan was recommended clinically considering daily setup variation.« less

Advancing Heliophysics and Space Weather Research with Student Internships and Faculty Development

NASA Astrophysics Data System (ADS)

Johnson, L. P.; Ng, C.; Marchese, P.; Austin, S. A.; Frost, J.; Cheung, T. K.; Tremberger, G.; Robbins, I.; Carlson, B. E.; Paglione, T.; Damas, C.; Steiner, J. C.; Rudolph, E.; Lewis, E.; Ford, K. S.; Cline, T.

2011-12-01

Expanding research capability in Heliophysics and Space Weather is the major focus of a collaboration between the City University of New York (CUNY) and NASA Goddard Space Fight Center (GSFC). The Heliophysics Education Consortium has a two-pronged approach centered on undergraduate research and faculty development. Summer 2011 student research projects include: Comparison of Fast Propagating Solar Waves and Slow Kelvin-Helmholtz Waves captured by SDO; Brightness Fluctuation of March 8, 2011 Eruption with Magnetic Rope Structure Measured by SDO; Investigation of Sunspot Regions, Coronal Mass Ejections and Solar Flares; An Integration and Testing Methodology for a Microsatellite; Comparative Analysis of Attitude Control Systems for Microsatellites; Spectral Analysis of Aerosols in Jupiter's Atmosphere Using HST Data; Alternative Sources of 5 GHz and 15 GHz Emissions in Active Galactic Nuclei; Probing Starburst-Driven Superwinds; Asteroid Astrometry; and Optimize an Electrostatic Deflection Element on PIXIES (Plasma Ion Experiment - Ion and Electron Sensor) for a CUNY student at GSFC. Faculty development workshops were conducted by Space Weather Action Center scientists. These workshops included a faculty development session at the CUNY Graduate Center and high school teachers professional development series at Queensborough Community College. The project is supported by NASA award NNX10AE72G.

A Multi-spacecraft Study of the Magnetospheric Influence on Ionospheric Chemistry - a Detailed Examination of Recent Geomagnetically Active Periods

NASA Astrophysics Data System (ADS)

Petrinec, S. M.; Chenette, D. L.; Imhof, W. L.; Baker, D. N.; Barth, C. A.; Mankoff, K. D.; Luhmann, J. G.; Mason, G. M.; Mazur, J. E.; Evans, D. S.

2001-12-01

A detailed analysis of the particle precipitation into the auroral regions during specific storm intervals is performed. The global energetic particle input to the ionosphere and lower thermosphere is provided by several monitors; namely the Polar Ionospheric X-ray Experiment (PIXIE) on board the NASA/GGS Polar satellite (for inferred electron energies greater than about 3 keV); the TED sensor system on board the NOAA/Polar Orbiting Environmental Satellite (POES) (particle energies between about 50 eV and 20 keV), and the sensor system (LICA) on board the Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX) spacecraft (for electron energies greater then 25 keV). Changes in nitric oxide (NO) densities at altitudes between 97 and 150 km during these storm intervals are studied using observations from the Student Nitric Oxide Explorer (SNOE). Solar wind observations are also used to provide important information regarding the external drivers for the magnetospheric input to the upper atmosphere. Specific intervals of examination include the recent large geomagnetic event of March 31-April 1, 2001, and other events from the most recent solar maximum.

Limits on the fluctuating part of y-type distortion monopole from Planck and SPT results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khatri, Rishi; Sunyaev, Rashid, E-mail: khatri@mpa-garching.mpg.de, E-mail: sunyaev@mpa-garching.mpg.de

2015-08-01

We use the published Planck and SPT cluster catalogs [1,2] and recently published y-distortion maps [3] to put strong observational limits on the contribution of the fluctuating part of the y-type distortions to the y-distortion monopole. Our bounds are 5.4× 10{sup −8} < ( y) < 2.2× 10{sup −6}. Our upper bound is a factor of 6.8 stronger than the currently best upper 95% confidence limit from COBE-FIRAS of ( y) <15× 10{sup −6}. In the standard cosmology, large scale structure is the only source of such distortions and our limits therefore constrain the baryonic physics involved in the formation of the large scale structure. Our lower limit, from themore » detected clusters in the Planck and SPT catalogs, also implies that a Pixie-like experiment should detect the y-distortion monopole at >27-σ. The biggest sources of uncertainty in our upper limit are the monopole offsets between different HFI channel maps that we estimate to be <10{sup −6}.« less

Beyond the Boost: Measuring the Intrinsic Dipole of the Cosmic Microwave Background Using the Spectral Distortions of the Monopole and Quadrupole.

PubMed

Yasini, Siavash; Pierpaoli, Elena

2017-12-01

We present a general framework for the accurate spectral modeling of the low multipoles of the cosmic microwave background (CMB) as observed in a boosted frame. In particular, we demonstrate how spectral measurements of the low multipoles can be used to separate the motion-induced dipole of the CMB from a possible intrinsic dipole component. In a moving frame, the leakage of an intrinsic dipole moment into the CMB monopole and quadrupole induces spectral distortions with distinct frequency functions that, respectively, peak at 337 and 276 GHz. The leakage into the quadrupole moment also induces a geometrical distortion to the spatial morphology of this mode. The combination of these effects can be used to lift the degeneracy between the motion-induced dipole and any intrinsic dipole that the CMB might possess. Assuming the current peculiar velocity measurements, the leakage of an intrinsic dipole with an amplitude of ΔT=30  μK into the monopole and quadrupole moments will be detectable by a PIXIE-like experiment at ∼40  nK (2.5σ) and ∼130  nK (11σ) level at their respective peak frequencies.

Interaction of external n  =  1 magnetic fields with the sawtooth instability in low-q RFX-mod and DIII-D tokamaks

NASA Astrophysics Data System (ADS)

Piron, C.; Martin, P.; Bonfiglio, D.; Hanson, J.; Logan, N. C.; Paz-Soldan, C.; Piovesan, P.; Turco, F.; Bialek, J.; Franz, P.; Jackson, G.; Lanctot, M. J.; Navratil, G. A.; Okabayashi, M.; Strait, E.; Terranova, D.; Turnbull, A.

2016-10-01

External n  =  1 magnetic fields are applied in RFX-mod and DIII-D low safety factor Tokamak plasmas to investigate their interaction with the internal MHD dynamics and in particular with the sawtooth instability. In these experiments the applied magnetic fields cause a reduction of both the sawtooth amplitude and period, leading to an overall stabilizing effect on the oscillations. In RFX-mod sawteeth eventually disappear and are replaced by a stationary m  =  1, n  =  1 helical equilibrium without an increase in disruptivity. However toroidal rotation is significantly reduced in these plasmas, thus it is likely that the sawtooth mitigation in these experiments is due to the combination of the helically deformed core and the reduced rotation. The former effect is qualitatively well reproduced by nonlinear MHD simulations performed with the PIXIE3D code. The results obtained in these RFX-mod experiments motivated similar ones in DIII-D L-mode diverted Tokamak plasmas at low q 95. These experiments succeeded in reproducing the sawtooth mitigation with the approach developed in RFX-mod. In DIII-D this effect is correlated with a clear increase of the n  =  1 plasma response, that indicates an enhancement of the coupling to the marginally stable n  =  1 external kink, as simulations with the linear MHD code IPEC suggest. A significant rotation braking in the plasma core is also observed in DIII-D. Numerical calculations of the neoclassical toroidal viscosity (NTV) carried out with PENT identify this torque as a possible contributor for this effect.

Testing inflation and curvaton scenarios with CMB distortions

NASA Astrophysics Data System (ADS)

Clesse, Sébastien; Garbrecht, Björn; Zhu, Yi

2014-10-01

Prior to recombination, Silk damping causes the dissipation of energy from acoustic waves into the monopole of the Cosmic Microwave Background (CMB), resulting in spectral distortions. These can be used to probe the primordial scalar power spectrum on smaller scales than it is possible with CMB anisotropies. An enhancement of power on these scales is nevertheless required for the resulting distortions to be detectable by future experiments like PIXIE. In this paper, we examine all 49 single-field inflation models listed by Martin et al. in the Encyclopaedia Inflationaris [1] and find that only one of these may lead to a detectable level of distortions in a tuned region of its parameter space, namely the original hybrid model. Three effective multi-field scenarios are also studied: with softly and suddenly turning trajectories, and with a mild waterfall trajectory. Softly turning trajectories do not induce distortions at any detectable level, whereas a sudden turn in the field space or a mild waterfall trajectory predicts a peak (plus damped oscillations in the sudden turn case) in the scalar power spectrum, which can lead to an observable amount of CMB distortions. Finally, another scenario leading to potentially detectable distortions involves a curvaton whose blue spectrum is subdominant on CMB angular scales and overtakes the inflaton spectrum on smaller scales. In this case however, we show that the bounds from ultra compact minihaloes are not satisfied. Expectations for an ultimate PRISM-class experiment characterized by an improvement in sensitivity by a factor of ten are discussed for some models.

Testing inflation and curvaton scenarios with CMB distortions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clesse, Sébastien; Garbrecht, Björn; Zhu, Yi, E-mail: s.clesse@tum.de, E-mail: garbrecht@tum.de, E-mail: yi.zhu@tum.de

2014-10-01

Prior to recombination, Silk damping causes the dissipation of energy from acoustic waves into the monopole of the Cosmic Microwave Background (CMB), resulting in spectral distortions. These can be used to probe the primordial scalar power spectrum on smaller scales than it is possible with CMB anisotropies. An enhancement of power on these scales is nevertheless required for the resulting distortions to be detectable by future experiments like PIXIE. In this paper, we examine all 49 single-field inflation models listed by Martin et al. in the Encyclopaedia Inflationaris [1] and find that only one of these may lead to amore » detectable level of distortions in a tuned region of its parameter space, namely the original hybrid model. Three effective multi-field scenarios are also studied: with softly and suddenly turning trajectories, and with a mild waterfall trajectory. Softly turning trajectories do not induce distortions at any detectable level, whereas a sudden turn in the field space or a mild waterfall trajectory predicts a peak (plus damped oscillations in the sudden turn case) in the scalar power spectrum, which can lead to an observable amount of CMB distortions. Finally, another scenario leading to potentially detectable distortions involves a curvaton whose blue spectrum is subdominant on CMB angular scales and overtakes the inflaton spectrum on smaller scales. In this case however, we show that the bounds from ultra compact minihaloes are not satisfied. Expectations for an ultimate PRISM-class experiment characterized by an improvement in sensitivity by a factor of ten are discussed for some models.« less

The role of autologous hematopoietic progenitor and cell reinfusion for intensive chemotherapy in women with poor-prognosis breast cancer. Clinical studies with ex-vivo expanded cells produced with the Aastrom Replicell technology.

PubMed

Chabannon, C; Novakovitch, G; Blache, J L; Olivero, S; Camerlo, J; Genre, D; Maraninchi, D; Viens, P

1999-04-01

In recent years, we have initiated two clinical studies, to evaluate the usefulness of ex-vivo expanded cells in patients with breast cancer who receive sequential high-dose chemotherapy. Ex-vivo expanded cells were produced from autologous cryopreserved bone marrow nucleated cells, using a biomedical device. The Aastrom Replicell system cultures cells in animal serum-replete medium, with a combination of flt3-L, PIXY321 and Epo, for 12 days. The initial pilot trial was set up to establish the feasibility and safety of the technique: 6 patients completed the study. An ongoing randomized study searches to establish whether ex-vivo expanded cells provide a clinical benefit.

Polarized anisotropic spectral distortions of the CMB: galactic and extragalactic constraints on photon-axion conversion

NASA Astrophysics Data System (ADS)

Mukherjee, Suvodip; Khatri, Rishi; Wandelt, Benjamin D.

2018-04-01

We revisit the cosmological constraints on resonant and non-resonant conversion of photons to axions in the cosmological magnetic fields. We find that the constraints on photon-axion coupling and primordial magnetic fields are much weaker than previously claimed for low mass axion like particles with masses ma lesssim 5× 10‑13 eV. {In particular we find that the axion mass range 10‑14 eV <= ma <= 5× 10‑13 eV is not excluded by {the} CMB data contrary to the previous claims.} We also examine the photon-axion conversion in the Galactic magnetic fields. Resonant conversion in the large scale coherent Galactic magnetic field results in 100% polarized anisotropic spectral distortions of the {CMB} for the mass range 10‑13 eV lesssim ma lesssim 10‑11 eV. The polarization pattern traces the transverse to line of sight component of the Galactic magnetic field while both the anisotropy in the Galactic magnetic field and electron distribution imprint a characteristic anisotropy pattern in the spectral distortion. Our results apply to scalar as well as pseudoscalar particles. {For conversion to scalar particles, the polarization is rotated by 90o allowing us to distinguish them from the pseudoscalars.} For ma lesssim 10‑14 eV we have non-resonant conversion in the small scale turbulent magnetic field of the Galaxy resulting in anisotropic but unpolarized spectral distortion in the CMB. These unique signatures are potential discriminants against the isotropic and non-polarized signals such as primary CMB, and μ and y distortions with the anisotropic nature making it accessible to experiments with only relative calibration like Planck, LiteBIRD, and CoRE. We forecast for PIXIE as well as for these experiments using Fisher matrix formalism.

PRIMORDIAL GRAVITATIONAL WAVE DETECTABILITY WITH DEEP SMALL-SKY COSMIC MICROWAVE BACKGROUND EXPERIMENTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farhang, M.; Bond, J. R.; Netterfield, C. B.

2013-07-01

We use the Bayesian estimation on direct T - Q - U cosmic microwave background (CMB) polarization maps to forecast errors on the tensor-to-scalar power ratio r, and hence on primordial gravitational waves, as a function of sky coverage f{sub sky}. This map-based likelihood filters the information in the pixel-pixel space into the optimal combinations needed for r detection for cut skies, providing enhanced information over a first-step linear separation into a combination of E, B, and mixed modes, and ignoring the latter. With current computational power and for typical resolutions appropriate for r detection, the large matrix inversions requiredmore » are accurate and fast. Our simulations explore two classes of experiments, with differing bolometric detector numbers, sensitivities, and observational strategies. One is motivated by a long duration balloon experiment like Spider, with pixel noise {proportional_to}{radical}(f{sub sky}) for a specified observing period. This analysis also applies to ground-based array experiments. We find that, in the absence of systematic effects and foregrounds, an experiment with Spider-like noise concentrating on f{sub sky} {approx} 0.02-0.2 could place a 2{sigma}{sub r} Almost-Equal-To 0.014 boundary ({approx}95% confidence level), which rises to 0.02 with an l-dependent foreground residual left over from an assumed efficient component separation. We contrast this with a Planck-like fixed instrumental noise as f{sub sky} varies, which gives a Galaxy-masked (f{sub sky} = 0.75) 2{sigma}{sub r} Almost-Equal-To 0.015, rising to Almost-Equal-To 0.05 with the foreground residuals. Using as the figure of merit the (marginalized) one-dimensional Shannon entropy of r, taken relative to the first 2003 WMAP CMB-only constraint, gives -2.7 bits from the 2012 WMAP9+ACT+SPT+LSS data, and forecasts of -6 bits from Spider (+ Planck); this compares with up to -11 bits for CMBPol, COrE, and PIXIE post-Planck satellites and -13 bits for a perfectly noiseless cosmic variance limited experiment. We thus confirm the wisdom of the current strategy for r detection of deeply probed patches covering the f{sub sky} minimum-error trough with balloon and ground experiments.« less

SYSTEMATIC EFFECTS IN POLARIZING FOURIER TRANSFORM SPECTROMETERS FOR COSMIC MICROWAVE BACKGROUND OBSERVATIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nagler, Peter C.; Tucker, Gregory S.; Fixsen, Dale J.

The detection of the primordial B-mode polarization signal of the cosmic microwave background (CMB) would provide evidence for inflation. Yet as has become increasingly clear, the detection of a such a faint signal requires an instrument with both wide frequency coverage to reject foregrounds and excellent control over instrumental systematic effects. Using a polarizing Fourier transform spectrometer (FTS) for CMB observations meets both of these requirements. In this work, we present an analysis of instrumental systematic effects in polarizing FTSs, using the Primordial Inflation Explorer (PIXIE) as a worked example. We analytically solve for the most important systematic effects inherentmore » to the FTS—emissive optical components, misaligned optical components, sampling and phase errors, and spin synchronous effects—and demonstrate that residual systematic error terms after corrections will all be at the sub-nK level, well below the predicted 100 nK B-mode signal.« less

A gamma-gamma coincidence/anticoincidence spectrometer for low-level cosmogenic (22)Na/(7)Be activity ratio measurement.

PubMed

Zhang, Weihua; Ungar, Kurt; Stukel, Matthew; Mekarski, Pawel

2014-04-01

In this study, a digital gamma-gamma coincidence/anticoincidence spectrometer was developed and examined for low-level cosmogenic (22)Na and (7)Be in air-filter sample monitoring. The spectrometer consists of two bismuth germanate scintillators (BGO) and an XIA LLC Digital Gamma Finder (DGF)/Pixie-4 software and card package. The spectrometer design allows a more selective measurement of (22)Na with a significant background reduction by gamma-gamma coincidence events processing. Hence, the system provides a more sensitive way to quantify trace amounts of (22)Na than normal high resolution gamma spectrometry providing a critical limit of 3 mBq within a 20 h count. The use of a list-mode data acquisition technique enabled simultaneous determination of (22)Na and (7)Be activity concentrations using a single measurement by coincidence and anticoincidence mode respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

Gravitational wave signatures of inflationary models from Primordial Black Hole dark matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

García-Bellido, Juan; Peloso, Marco; Unal, Caner, E-mail: juan.garciabellido@uam.es, E-mail: peloso@physics.umn.edu, E-mail: unal@physics.umn.edu

Primordial Black Holes (PBH) could be the cold dark matter of the universe. They could have arisen from large (order one) curvature fluctuations produced during inflation that reentered the horizon in the radiation era. At reentry, these fluctuations source gravitational waves (GW) via second order anisotropic stresses. These GW, together with those (possibly) sourced during inflation by the same mechanism responsible for the large curvature fluctuations, constitute a primordial stochastic GW background (SGWB) that unavoidably accompanies the PBH formation. We study how the amplitude and the range of frequencies of this signal depend on the statistics (Gaussian versus χ{sup 2})more » of the primordial curvature fluctuations, and on the evolution of the PBH mass function due to accretion and merging. We then compare this signal with the sensitivity of present and future detectors, at PTA and LISA scales. We find that this SGWB will help to probe, or strongly constrain, the early universe mechanism of PBH production. The comparison between the peak mass of the PBH distribution and the peak frequency of this SGWB will provide important information on the merging and accretion evolution of the PBH mass distribution from their formation to the present era. Different assumptions on the statistics and on the PBH evolution also result in different amounts of CMB μ-distortions. Therefore the above results can be complemented by the detection (or the absence) of μ-distortions with an experiment such as PIXIE.« less

Extracting foreground-obscured μ-distortion anisotropies to constrain primordial non-Gaussianity

NASA Astrophysics Data System (ADS)

Remazeilles, M.; Chluba, J.

2018-07-01

Correlations between cosmic microwave background (CMB) temperature, polarization, and spectral distortion anisotropies can be used as a probe of primordial non-Gaussianity. Here, we perform a reconstruction of μ-distortion anisotropies in the presence of Galactic and extragalactic foregrounds, applying the so-called Constrained ILC component separation method to simulations of proposed CMB space missions (PIXIE, LiteBIRD, CORE, and PICO). Our sky simulations include Galactic dust, Galactic synchrotron, Galactic free-free, thermal Sunyaev-Zeldovich effect, as well as primary CMB temperature and μ-distortion anisotropies, the latter being added as correlated field. The Constrained ILC method allows us to null the CMB temperature anisotropies in the reconstructed μ-map (and vice versa), in addition to mitigating the contaminations from astrophysical foregrounds and instrumental noise. We compute the cross-power spectrum between the reconstructed (CMB-free) μ-distortion map and the (μ-free) CMB temperature map, after foreground removal and component separations. Since the cross-power spectrum is proportional to the primordial non-Gaussianity parameter, fNL, on scales k˜eq 740 Mpc^{-1}, this allows us to derive fNL-detection limits for the aforementioned future CMB experiments. Our analysis shows that foregrounds degrade the theoretical detection limits (based mostly on instrumental noise) by more than one order of magnitude, with PICO standing the best chance at placing upper limits on scale-dependent non-Gaussianity. We also discuss the dependence of the constraints on the channel sensitivities and chosen bands. Like for B-mode polarization measurements, extended coverage at frequencies ν ≲ 40 GHz and ν ≳ 400 GHz provides more leverage than increased channel sensitivity.

Extracting foreground-obscured μ-distortion anisotropies to constrain primordial non-Gaussianity

NASA Astrophysics Data System (ADS)

Remazeilles, M.; Chluba, J.

2018-04-01

Correlations between cosmic microwave background (CMB) temperature, polarization and spectral distortion anisotropies can be used as a probe of primordial non-Gaussianity. Here, we perform a reconstruction of μ-distortion anisotropies in the presence of Galactic and extragalactic foregrounds, applying the so-called Constrained ILC component separation method to simulations of proposed CMB space missions (PIXIE, LiteBIRD, CORE, PICO). Our sky simulations include Galactic dust, Galactic synchrotron, Galactic free-free, thermal Sunyaev-Zeldovich effect, as well as primary CMB temperature and μ-distortion anisotropies, the latter being added as correlated field. The Constrained ILC method allows us to null the CMB temperature anisotropies in the reconstructed μ-map (and vice versa), in addition to mitigating the contaminations from astrophysical foregrounds and instrumental noise. We compute the cross-power spectrum between the reconstructed (CMB-free) μ-distortion map and the (μ-free) CMB temperature map, after foreground removal and component separation. Since the cross-power spectrum is proportional to the primordial non-Gaussianity parameter, fNL, on scales k˜eq 740 Mpc^{-1}, this allows us to derive fNL-detection limits for the aforementioned future CMB experiments. Our analysis shows that foregrounds degrade the theoretical detection limits (based mostly on instrumental noise) by more than one order of magnitude, with PICO standing the best chance at placing upper limits on scale-dependent non-Gaussianity. We also discuss the dependence of the constraints on the channel sensitivities and chosen bands. Like for B-mode polarization measurements, extended coverage at frequencies ν ≲ 40 GHz and ν ≳ 400 GHz provides more leverage than increased channel sensitivity.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zotti, G. De; Negrello, M.; Castex, G.

We review aspects of Cosmic Microwave Background (CMB) spectral distortions which do not appear to have been fully explored in the literature. In particular, implications of recent evidences of heating of the intergalactic medium (IGM) by feedback from active galactic nuclei are investigated. Taking also into account the IGM heating associated to structure formation, we argue that values of the y parameter of several × 10{sup −6}, i.e. a factor of a few below the COBE/FIRAS upper limit, are to be expected. The Compton scattering by the re-ionized plasma also re-processes primordial distortions, adding a y-type contribution. Hence no pure Bose-Einstein-likemore » distortions are to be expected. An assessment of Galactic and extragalactic foregrounds, taking into account the latest results from the Planck satellite as well as the contributions from the strong CII and CO lines from star-forming galaxies, demonstrates that a foreground subtraction accurate enough to fully exploit the PIXIE sensitivity will be extremely challenging. Motivated by this fact we also discuss methods to detect spectral distortions not requiring absolute measurements and show that accurate determinations of the frequency spectrum of the CMB dipole amplitude may substantially improve over COBE/FIRAS limits on distortion parameters. Such improvements may be at reach of next generation CMB anisotropy experiments. The estimated amplitude of the Cosmic Infrared Background (CIB) dipole might be detectable by careful analyses of Planck maps at the highest frequencies. Thus Planck might provide interesting constraints on the CIB intensity, currently known with a ≅ 30% uncertainty.« less

Host Range of a Population of Pratylenchus vulnus in Commercial Fruit, Nut, Citrus, and Grape Rootstocks in Spain.

PubMed

Pinochet, J; Verdejo, S; Soler, A; Canals, J

1992-12-01

In a host-range study carried out under greenhouse conditions, a total of 37 commercial fruit tree, grape, and citrus rootstocks were tested for their reaction to a population of the lesion nematode, Pratylenchus vulnus, in Spain. Twenty-five rootstocks had a Pf/Pi > 1.5. These included almond (Desmayo Rojo, 1143), apple (EM-9, EM-106), avocado (Hass), cherry (Santa Lucia 64, Camil, M x M 14, Masto de Montafiana), grape (41-B, Fercal, Ritcher 110), hazelnut (Pauetet), loquat (Nadal), peach (Montclar, GF-305), pear (OHF-333), pistachio (P. atlantica, P. vera, P. terebinthus), plum (San Julian 655-2, Montizo, Pixy, Myrobalan 605), and walnut (Serf). The peach rootstock Nemaguard and the grape 161-49 had Pf/Pi between 1.0 and 1.5 (slightly higher than inoculation level). All the tested citrus (Alemow, rough lemon, Carrizo citrange, sour orange, Troyer citrange, Citrumelo), plus three grape (SO4, Vitis rupestris, 1103-P), and the olive rootstock Arbequina had a Pf/Pi < 1.0.

Fourth order discretization of anisotropic heat conduction operator

NASA Astrophysics Data System (ADS)

Krasheninnikova, Natalia; Chacon, Luis

2008-11-01

In magnetized plasmas, heat conduction plays an important role in such processes as energy confinement, turbulence, and a number of instabilities. As a consequence of the presence of a magnetic field, heat transport is strongly anisotropic, with energy flowing preferentially along the magnetic field direction. This in turn results in parallel and perpendicular heat conduction coefficients being separated by orders of magnitude. The computational difficulties in treating such heat conduction anisotropies are significant, as perpendicular dynamics numerically is polluted by the parallel one. In this work, we report on progress of the implementation of a fourth order, conservative finite volume discretization scheme for the anisotropic heat conduction operator into the extended MHD code PIXIE3D [1]. We will demonstrate its spatial discretization accuracy and its effectiveness with two physical applications of interest, both of which feature a strong sensitivity to the heat conduction anisotropy: the thermal instability and the neoclassical tearing mode. [1] L. Chacon Phys. Plasmas 15, 056103 (2008)

Cosmic-muon intensity measurement and overburden estimation in a building at surface level and in an underground facility using two BC408 scintillation detectors coincidence counting system.

PubMed

Zhang, Weihua; Ungar, Kurt; Liu, Chuanlei; Mailhot, Maverick

2016-10-01

A series of measurements have been recently conducted to determine the cosmic-muon intensities and attenuation factors at various indoor and underground locations for a gamma spectrometer. For this purpose, a digital coincidence spectrometer was developed by using two BC408 plastic scintillation detectors and an XIA LLC Digital Gamma Finder (DGF)/Pixie-4 software and card package. The results indicate that the overburden in the building at surface level absorbs a large part of cosmic ray protons while attenuating the cosmic-muon intensity by 20-50%. The underground facility has the largest overburden of 39 m water equivalent, where the cosmic-muon intensity is reduced by a factor of 6. The study provides a cosmic-muon intensity measurement and overburden assessment, which are important parameters for analysing the background of an HPGe counting system, or for comparing the background of similar systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

Application of Cathodoluminescence to The Study of Feldspars: Imaging and Spectrometry

NASA Astrophysics Data System (ADS)

Fonseca, Rute; Couto, Helena

2017-12-01

Cathodoluminescence (CL) studies were carried out on polished thin sections of different feldspar samples (from migmatites, granites, aplite-pegmatites and granitic aggregates) using a hot cathode CL equipment HC3-LM coupled to an optical microscope and to a spectrometer (SpectraPro 2300i and a CCD Pixis 400B detector and the software Winspec32) from the Faculty of Sciences of University of Porto. The system was operated at 14kV and a filament current of 0.18 mA. The samples were coated with a thin gold film using a Cressington 108 Auto device. Luminescence images were acquired during the CL analysis with an adapted digital video-camera (KAPPA PS 40C-285 (DX) with dual stage Peltier cooling) and an acquisition time between 351ms and 3,52s. The CL study, including imaging and spectrometry, proved to be an important tool to complement the feldspar petrography as it contributes to the identification of features not observed under optical microscope. The application of the Cathodoluminescence to feldspar allows distinguishing between potassic feldspar and plagioclase, differentiating generations of feldspar and displaying internal zoning and growth areas, among other. The spectrometry complements the CL imaging. It allows obtaining a qualitative level of emission intensity, which permits the interpretation of the nature of this luminescence in each feldspar. Bands shown in the spectra are related to the existing activator elements. In the present study, it was found an association of each feldspar to different spectra and respective colour. The plagioclases exhibit yellow or green luminescence. The activator element is Mn2+, showing a broad emission band between 550 - 570 nm specially detected on this type of feldspars, due to the replacement of K+ for Mn2+. The potassium feldspars have more or less intense blue colour associated with various activators elements: the activator element is Cu2+ showing a broad emission band between 420±5 nm. This emission band can be detected either in potassium feldspar or in plagioclases, but when associated with the blue colour, it indicates that it is a potassium feldspar. Spectra with a wavelength of 460±10 nm, associated to the element activator/synthesizer Ti3+, which is initially deposited as Ti4+, replacing Al, as temperature rise. The emission band with a wavelength of 860 nm correspond to the activator element Pb+, and occurs specially in potassium feldspar like adularia and orthoclase. The activator element Al - O - Al, show a broad emission band between 450-480 nm. This emission in CL is caused by the replacement of Al3+ and Si4+ in feldspars.

DISSECTING THE HIGH- z INTERSTELLAR MEDIUM THROUGH INTENSITY MAPPING CROSS-CORRELATIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serra, Paolo; Doré, Olivier; Lagache, Guilaine, E-mail: Paolo.Serra@jpl.nasa.gov

We explore the detection, with upcoming spectroscopic surveys, of three-dimensional power spectra of emission line fluctuations produced in different phases of the interstellar medium (ISM) by forbidden transitions of ionized carbon [C ii] (157.7 μ m), ionized nitrogen [N ii] (121.9 and 205.2 μ m), and neutral oxygen [O i] (145.5 μ m) at redshift z  > 4. These lines are important coolants of both the neutral and the ionized medium, and probe multiple phases of the ISM. In the framework of the halo model, we compute predictions of the three-dimensional power spectra for two different surveys, showing that they havemore » the required sensitivity to detect cross-power spectra between the [C ii] line and both the [O i] line and the [N ii] lines with sufficient signal-to-noise ratio. The importance of cross-correlating multiple lines with the intensity mapping technique is twofold. On the one hand, we will have multiple probes of the different phases of the ISM, which is key to understanding the interplay between energetic sources, and the gas and dust at high redshift. This kind of study will be useful for a next-generation space observatory such as the NASA Far-IR Surveyor, which will probe the global star formation and the ISM of galaxies from the peak of star formation to the epoch of reionization. On the other hand, emission lines from external galaxies are an important foreground when measuring spectral distortions of the cosmic microwave background spectrum with future space-based experiments like PIXIE; measuring fluctuations in the intensity mapping regime will help constrain the mean amplitude of these lines, and will allow us to better handle this important foreground.« less

Robust forecasts on fundamental physics from the foreground-obscured, gravitationally-lensed CMB polarization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Errard, Josquin; Feeney, Stephen M.; Jaffe, Andrew H.

2016-03-01

Recent results from the BICEP, Keck Array and Planck Collaborations demonstrate that Galactic foregrounds are an unavoidable obstacle in the search for evidence of inflationary gravitational waves in the cosmic microwave background (CMB) polarization. Beyond the foregrounds, the effect of lensing by intervening large-scale structure further obscures all but the strongest inflationary signals permitted by current data. With a plethora of ongoing and upcoming experiments aiming to measure these signatures, careful and self-consistent consideration of experiments' foreground- and lensing-removal capabilities is critical in obtaining credible forecasts of their performance. We investigate the capabilities of instruments such as Advanced ACTPol, BICEP3more » and Keck Array, CLASS, EBEX10K, PIPER, Simons Array, SPT-3G and SPIDER, and projects as COrE+, LiteBIRD-ext, PIXIE and Stage IV, to clean contamination due to polarized synchrotron and dust from raw multi-frequency data, and remove lensing from the resulting co-added CMB maps (either using iterative CMB-only techniques or through cross-correlation with external data). Incorporating these effects, we present forecasts for the constraining power of these experiments in terms of inflationary physics, the neutrino sector, and dark energy parameters. Made publicly available through an online interface, this tool enables the next generation of CMB experiments to foreground-proof their designs, optimize their frequency coverage to maximize scientific output, and determine where cross-experimental collaboration would be most beneficial. We find that analyzing data from ground, balloon and space instruments in complementary combinations can significantly improve component separation performance, delensing, and cosmological constraints over individual datasets. In particular, we find that a combination of post-2020 ground- and space-based experiments could achieve constraints such as σ(r)∼1.3×10{sup −4}, σ(n{sub t})∼0.03, σ( n{sub s} )∼1.8×10{sup −3}, σ(α{sub s})∼1.7×10{sup −3}, σ( M{sub ν} )∼31 meV, σ( w )∼0.09, σ( w{sub 0} )∼ 0.25, 0σ( w{sub a} )∼ 0.5, σ( N{sub eff} )∼0.024 and σ( Ω{sub k} )∼1.5×10{sup −3}, after component separation and iterative delensing.« less

In vitro food production for isolated closed environments: formation of ripe tomato fruits from excised flower buds.

PubMed

Applewhite, P B; K-Sawhney, R; Galston, A W

1997-01-01

Excised preanthesis flower buds of young Pixie Hybrid tomato plants develop into red ripe fruits in aseptic culture on a modified Murashige-Skoog medium with 3% sucrose at pH 5.8. The addition of certain synthetic auxins (IAA, NAA, IBA), auxin precursors (ISA), or cytokinins (KIN, IPA, ZEA, BAP) to the medium improved the percentage of buds developing into fruits, the weight of the ripe fruits, or both. The best results were obtained by an auxin-cytokinin combination of 10 microM IBA with 1 microM BAP. Storage of the excised buds at low temperature (6 degrees C) for up to 4 weeks before transfer to 27 degrees C caused only minimal deterioration in size and number of the fruit crop. Extension of low-temperature storage to 8 weeks produced smaller fruits that took longer to develop. This system could produce fresh, ripe small tomatoes on a sustained basis for up to 2 months for an isolated environment such as a space vehicle or submarine.

New discoveries of mud volcanoes on the Moroccan Atlantic continental margin (Gulf of Cádiz): morpho-structural characterization

NASA Astrophysics Data System (ADS)

León, Ricardo; Somoza, Luis; Medialdea, Teresa; Vázquez, Juan Tomás; González, Francisco Javier; López-González, Nieves; Casas, David; del Pilar Mata, María; del Fernández-Puga, María Carmen; Giménez-Moreno, Carmen Julia; Díaz-del-Río, Víctor

2012-12-01

During the MVSEIS-08 cruise of 2008, ten new mud volcanoes (MVs) were discovered on the offshore Moroccan continental margin (Gulf of Cádiz) at water depths between 750 and 1,600 m, using multibeam bathymetry, backscatter imagery, high-resolution seismic and gravity core data. Mud breccias were recovered in all cases, attesting to the nature of extrusion of these cones. The mud volcanoes are located in two fields: the MVSEIS, Moundforce, Pixie, Las Negras, Madrid, Guadix, Almanzor and El Cid MVs in the western Moroccan field, where mud volcanoes have long been suspected but to date not identified, and the Boabdil and Al Gacel MVs in the middle Moroccan field. Three main morphologies were observed: asymmetric, sub-circular and flat-topped cone-shaped types, this being the first report of asymmetric morphologies in the Gulf of Cádiz. Based on morpho-structural analysis, the features are interpreted to result from (1) repeated constructive (expulsion of fluid mud mixtures) and destructive (gravity-induced collapse and submarine landsliding) episodes and (2) interaction with bottom currents.

Quantification of 235U and 238U activity concentrations for undeclared nuclear materials by a digital gamma-gamma coincidence spectroscopy.

PubMed

Zhang, Weihua; Yi, Jing; Mekarski, Pawel; Ungar, Kurt; Hauck, Barry; Kramer, Gary H

2011-06-01

The purpose of this study is to investigate the possibility of verifying depleted uranium (DU), natural uranium (NU), low enriched uranium (LEU) and high enriched uranium (HEU) by a developed digital gamma-gamma coincidence spectroscopy. The spectroscopy consists of two NaI(Tl) scintillators and XIA LLC Digital Gamma Finder (DGF)/Pixie-4 software and card package. The results demonstrate that the spectroscopy provides an effective method of (235)U and (238)U quantification based on the count rate of their gamma-gamma coincidence counting signatures. The main advantages of this approach over the conventional gamma spectrometry include the facts of low background continuum near coincident signatures of (235)U and (238)U, less interference from other radionuclides by the gamma-gamma coincidence counting, and region-of-interest (ROI) imagine analysis for uranium enrichment determination. Compared to conventional gamma spectrometry, the method offers additional advantage of requiring minimal calibrations for (235)U and (238)U quantification at different sample geometries. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

Simulations of Plasmasheet Electrons in a Model Magnetosphere with AMIE Potentials: Implications for Diffuse Aurora

NASA Astrophysics Data System (ADS)

Chen, M. W.; Schulz, M.; Lu, G.

2001-12-01

We obtain distributions of precipitating electrons by tracing drift shells of plasmasheet electrons in the limit of strong pitch angle diffusion in Dungey's model magnetosphere, which consists of a dipolar magnetic field plus a uniform southward field. Under strong pitch-angle diffusion particles drift so as to conserve an adiabatic invariant Λ equal to the enclosed phase-space volume (i.e., the cube of the particle momentum p times the occupied flux-tube volume per unit magnetic flux). In the past we applied a quiescent Stern-Volland electric-field model with a cross-tail potential drop of 25 kV and added to it a storm-associated Brice-Nishida cross-magnetospheric electric field with impulses to represent substorm effects. For the present study we use the more realistic Assimilative Model of Ionospheric Electrodynamics (AMIE). We use an analytical expansion to express the AMIE ionospheric potential as a function of latitude and magnetic local time. We map this AMIE potential to latitudes >= 50^o to magnetospheric field lines with (L \\ge 2.5) in Dungey's magnetic field model. We trace the bounce-averaged drift motion of representative plasmasheet electrons for values of \\Lambda corresponding to energies of 0.25-64 keV on field lines of equatorial radial distance r = 6 R_E (L = 5.7), which maps to \\approx 65^o$ latitude in the ionosphere. We use the simulation results to map stormtime phase space distributions taking into account loss due to precipitation. We consider 2 models of electron scattering: (1) the limit of strong scattering everywhere, and (2) an MLT-dependent scattering that is less than everywhere strong in the plasma sheet. From the phase space distributions we calculate the total precipitating electron energy flux into the ionosphere. For this study we focus on the October 19, 1998, storm. We compare qualitatively the simulated energy flux with X-ray intensity from Polar/PIXIE images during this storm.

Ethnic Differences in Bending Stiffness of the Ulna and Tibia

NASA Technical Reports Server (NTRS)

Arnaud, S. B.; Liang, M. T. C.; Bassin, S.; Braun, W.; Dutto, D.; Plesums, K.; Huvnh, H. T.; Cooper, D.; Wong, N.

2004-01-01

There is considerable information about the variations in bone mass associated with different opportunity to compare a mechanical property of bone in young college women of Caucasian, Hispanic and Asian descent who gave informed consent to participate in an exercise study. The subjects were sedentary, in good health, eumenorrheic, non-smokers and had body mass indices (BMI) less than 30. Measurements acquired were body weight, kg, and height, cm, calcaneal and wrist bone density, g/square cm (PIXI, Lunar GE) and bending stiffness (EI, Nm(exp 2)) in the ulna and tibia. E1 was determined non-invasively with an instrument called the Mechanical Response Tissue Analyzer (MRTA) that delivers a vibratory stimulus to the center of the ulna or tibia and analyzes the response curve based on the equation E1 = k(sub b) L(exp 3)/48 where k, is lateral bending stiffness, L is the length of the bone, E is Young's modulus of elasticity and I, the bending moment of inertia. The error of the test (CV) based on measurements of an aluminum rod with a known E1 was 4.8%, of calcaneal BMD, 0.54%, and of wrist bone density, 3.45%.

Nonlinear 3D visco-resistive MHD modeling of fusion plasmas: a comparison between numerical codes

NASA Astrophysics Data System (ADS)

Bonfiglio, D.; Chacon, L.; Cappello, S.

2008-11-01

Fluid plasma models (and, in particular, the MHD model) are extensively used in the theoretical description of laboratory and astrophysical plasmas. We present here a successful benchmark between two nonlinear, three-dimensional, compressible visco-resistive MHD codes. One is the fully implicit, finite volume code PIXIE3D [1,2], which is characterized by many attractive features, notably the generalized curvilinear formulation (which makes the code applicable to different geometries) and the possibility to include in the computation the energy transport equation and the extended MHD version of Ohm's law. In addition, the parallel version of the code features excellent scalability properties. Results from this code, obtained in cylindrical geometry, are compared with those produced by the semi-implicit cylindrical code SpeCyl, which uses finite differences radially, and spectral formulation in the other coordinates [3]. Both single and multi-mode simulations are benchmarked, regarding both reversed field pinch (RFP) and ohmic tokamak magnetic configurations. [1] L. Chacon, Computer Physics Communications 163, 143 (2004). [2] L. Chacon, Phys. Plasmas 15, 056103 (2008). [3] S. Cappello, Plasma Phys. Control. Fusion 46, B313 (2004) & references therein.

Effects of elevated atmospheric carbon dioxide concentrations on water and acid requirements of soybeans grown in a recirculating hydroponic system

NASA Technical Reports Server (NTRS)

Mackowiak, C. L.; Wheeler, R. M.; Lowery, W.; Sager, J. C.

1990-01-01

Establishing mass budgets of various crop needs, i.e. water and nutrients, in different environments is essential for the Controlled Ecological Life Support System (CELSS). The effects of CO2 (500 and 1000 umol mol (exp -1)) on water and acid use (for pH control) by soybeans in a recirculating hydroponic system were examined. Plants of cvs. McCall and Pixie were grown for 90 days using the nutrient film technique (NFT) and a nitrate based nutrient solution. System acid use for both CO2 levels peaked near 4 weeks during a phase of rapid vegetative growth, but acid use decreased more rapidly under 500 compared to 1000 umol mol (exp GR) CO2. Total system water use by 500 and 1000 umol mol (exp -1) plants was similar, leaving off at 5 weeks and declining as plants senesced (ca. 9 weeks). However, single leaf transpiration rates were consistently lower at 1000 umol mol (exp -1). The data suggest that high CO2 concentrations increase system acid (and nutrient) use because of increased vegetative growth, which in turn negates the benefit of reduced water use (lower transpiration rates) per unit leaf area.

Image quality scaling of electrophotographic prints

NASA Astrophysics Data System (ADS)

Johnson, Garrett M.; Patil, Rohit A.; Montag, Ethan D.; Fairchild, Mark D.

2003-12-01

Two psychophysical experiments were performed scaling overall image quality of black-and-white electrophotographic (EP) images. Six different printers were used to generate the images. There were six different scenes included in the experiment, representing photographs, business graphics, and test-targets. The two experiments were split into a paired-comparison experiment examining overall image quality, and a triad experiment judging overall similarity and dissimilarity of the printed images. The paired-comparison experiment was analyzed using Thurstone's Law, to generate an interval scale of quality, and with dual scaling, to determine the independent dimensions used for categorical scaling. The triad experiment was analyzed using multidimensional scaling to generate a psychological stimulus space. The psychophysical results indicated that the image quality was judged mainly along one dimension and that the relationships among the images can be described with a single dimension in most cases. Regression of various physical measurements of the images to the paired comparison results showed that a small number of physical attributes of the images could be correlated with the psychophysical scale of image quality. However, global image difference metrics did not correlate well with image quality.

Cosmological constraints on exotic injection of electromagnetic energy

NASA Astrophysics Data System (ADS)

Poulin, Vivian; Lesgourgues, Julien; Serpico, Pasquale D.

2017-03-01

We compute cosmic microwave background (CMB) anisotropy constraints on exotic forms of energy injection in electromagnetic (e.m.) channels over a large range of timescales. We show that these constraints are very powerful around or just after recombination, although CMB keeps some sensitivity e.g. to decaying species with lifetimes as long as 1025 s. These bounds are complementary to CMB spectral distortions and primordial nucleosynthesis ones, which dominate at earlier timescales, as we also review here. For the first time, we describe the effects of the e.m. energy injection on the CMB power spectra as a function of the injection epoch, using the lifetime of a decaying particle as proxy. We also identify a suitable on-the-spot approximation, that can be used to derive accurate constraints, and describe its differences with the most up-to-date treatment. Our results are of interest not only for early universe relics constituting (a fraction of) the dark matter, but also for other exotic injection of e.m. radiation. For illustration, we apply our formalism to: i) Primordial black holes of mass 1013.5 g lesssim M lesssim 1016.8 g, showing that the constraints are comparable to the ones obtained from gamma-ray background studies and even dominate below ~ 1014 g. ii) To a peculiar mass-mixing range in the sterile neutrino parameter space, complementary to other astrophysical and laboratory probes. iii) Finally, we provide a first estimate of the room for improvement left for forthcoming 21 cm experiments, comparing it with the reach of proposed CMB spectral distortion (PiXiE) and CMB angular power spectrum (CORE) missions. We show that the best and most realistic opportunity to look for this signal (or to improve over current constraints) in the 21 cm probe is to focus on the Cosmic Dawn epoch, 15 lesssim z lesssim 30, where the qualitatively unambiguous signature of a spectrum in emission can be expected for models that evade all current constraints.

V-Sipal - a Virtual Laboratory for Satellite Image Processing and Analysis

NASA Astrophysics Data System (ADS)

Buddhiraju, K. M.; Eeti, L.; Tiwari, K. K.

2011-09-01

In this paper a virtual laboratory for the Satellite Image Processing and Analysis (v-SIPAL) being developed at the Indian Institute of Technology Bombay is described. v-SIPAL comprises a set of experiments that are normally carried out by students learning digital processing and analysis of satellite images using commercial software. Currently, the experiments that are available on the server include Image Viewer, Image Contrast Enhancement, Image Smoothing, Edge Enhancement, Principal Component Transform, Texture Analysis by Co-occurrence Matrix method, Image Indices, Color Coordinate Transforms, Fourier Analysis, Mathematical Morphology, Unsupervised Image Classification, Supervised Image Classification and Accuracy Assessment. The virtual laboratory includes a theory module for each option of every experiment, a description of the procedure to perform each experiment, the menu to choose and perform the experiment, a module on interpretation of results when performed with a given image and pre-specified options, bibliography, links to useful internet resources and user-feedback. The user can upload his/her own images for performing the experiments and can also reuse outputs of one experiment in another experiment where applicable. Some of the other experiments currently under development include georeferencing of images, data fusion, feature evaluation by divergence andJ-M distance, image compression, wavelet image analysis and change detection. Additions to the theory module include self-assessment quizzes, audio-video clips on selected concepts, and a discussion of elements of visual image interpretation. V-SIPAL is at the satge of internal evaluation within IIT Bombay and will soon be open to selected educational institutions in India for evaluation.

Compton suppression and event triggering in a commercial data acquisition system

NASA Astrophysics Data System (ADS)

Tabor, Samuel; Caussyn, D. D.; Tripathi, Vandana; Vonmoss, J.; Liddick, S. N.

2012-10-01

A number of groups are starting to use flash digitizer systems to directly convert the preamplifier signals of high-resolution Ge detectors to a stream of digital data. Some digitizers are also equipped with software constant fraction discriminator algorithms capable of operating on the resulting digital data stream to provide timing information. Because of the dropping cost per channel of these systems, it should now be possible to also connect outputs of the Bismuth Germanate (BGO) scintillators used for Compton suppression to other digitizer inputs so that BGO logic signals can also be available in the same system. This provides the possibility to perform all the Compton suppression and multiplicity trigger logic within the digital system, thus eliminating the need for separate timing filter amplifiers (TFA), constant fraction discriminators (CFD), logic units, and lots of cables. This talk will describe the performance of such a system based on Pixie16 modules from XIA LLC with custom field programmable gate array (FPGA) programming for an array of Compton suppressed single Ge crystal and 4-crystal ``Clover'' detector array along with optional particle detectors. Initial tests of the system have produced results comparable with the current traditional system of individual electronics and peak sensing analog to digital converters. The advantages of the all digital system will be discussed.

Measurements of the ^89Y(n,n')^89Y^m reaction cross section using the ASP D-T fusion source

NASA Astrophysics Data System (ADS)

Simons, Andrew; Gardner, Matthew; Williams, Ben; Rubery, Michael

2012-10-01

A programme of measurements of the ^89Y(n,n')^89Y^m reaction cross section has commenced at AWE using the ASP accelerator to impinge deuterons onto tritiated titanium layers mounted on copper discs producing fluxes of approximately 10^11 neutrons per second. The neutrons are generated for up to half an hour and are used to excite Yttrium into its first isomeric state at 909.1 keV which then decays with a half life of 15.7 seconds. Two other high purity foils (of ^27Al and ^63,65Cu) are used as a reference to establish consistency between the isotopes energetic and temporal decay signatures. These foils mainly serve to check the reported total neutron fluence, produced by the accelerator, incident on the targets. The activation foils are extracted from the irradiation position by a pneumatic transfer system in ˜ 7 seconds and are transferred to the counting station in 5 to 30 seconds. Data are taken with a BEGe detector and recorded with both a Canberra Genie analogue system and a Xia Pixie-4 digital system. The results from the first campaigns are presented with a discussion of improvements and future plans.

How Visuo-Spatial Mental Imagery Develops: Image Generation and Maintenance

PubMed Central

Wimmer, Marina C.; Maras, Katie L.; Robinson, Elizabeth J; Doherty, Martin J; Pugeault, Nicolas

2015-01-01

Two experiments examined the nature of visuo-spatial mental imagery generation and maintenance in 4-, 6-, 8-, 10-year old children and adults (N = 211). The key questions were how image generation and maintenance develop (Experiment 1) and how accurately children and adults coordinate mental and visually perceived images (Experiment 2). Experiment 1 indicated that basic image generation and maintenance abilities are present at 4 years of age but the precision with which images are generated and maintained improves particularly between 4 and 8 years. In addition to increased precision, Experiment 2 demonstrated that generated and maintained mental images become increasingly similar to visually perceived objects. Altogether, findings suggest that for simple tasks demanding image generation and maintenance, children attain adult-like precision younger than previously reported. This research also sheds new light on the ability to coordinate mental images with visual images in children and adults. PMID:26562296

Magnetic Field Gradient Calibration as an Experiment to Illustrate Magnetic Resonance Imaging

ERIC Educational Resources Information Center

Seedhouse, Steven J.; Hoffmann, Markus M.

2008-01-01

A nuclear magnetic resonance (NMR) spectroscopy experiment for the undergraduate physical chemistry laboratory is described that encompasses both qualitative and quantitative pedagogical goals. Qualitatively, the experiment illustrates how images are obtained in magnetic resonance imaging (MRI). Quantitatively, students experience the…

MISR Browse Images: Cold Land Processes Experiment (CLPX)

Atmospheric Science Data Center

2013-04-02

... MISR Browse Images: Cold Land Processes Experiment (CLPX) These MISR Browse images provide a ... over the region observed during the NASA Cold Land Processes Experiment (CLPX). CLPX involved ground, airborne, and satellite measurements ...

What makes a face photo a 'good likeness'?

PubMed

Ritchie, Kay L; Kramer, Robin S S; Burton, A Mike

2018-01-01

Photographs of people are commonly said to be 'good likenesses' or 'poor likenesses', and this is a concept that we readily understand. Despite this, there has been no systematic investigation of what makes an image a good likeness, or of which cognitive processes are involved in making such a judgement. In three experiments, we investigate likeness judgements for different types of images: natural images of film stars (Experiment 1), images of film stars from specific films (Experiment 2), and iconic images and face averages (Experiment 3). In all three experiments, participants rated images for likeness and completed speeded name verification tasks. We consistently show that participants are faster to identify images which they have previously rated asa good likeness compared to a poor likeness. We also consistently show that the more familiar we are with someone, the higher likeness rating we give to all images of them. A key finding is that our perception of likeness is idiosyncratic (Experiments 1 and 2), and can be tied to our specific experience of each individual (Experiment 2). We argue that likeness judgements require a comparison between the stimulus and our own representation of the person, and that this representation differs according to our prior experience with that individual. This has theoretical implications for our understanding of how we represent familiar people, and practical implications for how we go about selecting images for identity purposes such as photo-ID. Copyright © 2017 Elsevier B.V. All rights reserved.

Pictures, images, and recollective experience.

PubMed

Dewhurst, S A; Conway, M A

1994-09-01

Five experiments investigated the influence of picture processing on recollective experience in recognition memory. Subjects studied items that differed in visual or imaginal detail, such as pictures versus words and high-imageability versus low-imageability words, and performed orienting tasks that directed processing either toward a stimulus as a word or toward a stimulus as a picture or image. Standard effects of imageability (e.g., the picture superiority effect and memory advantages following imagery) were obtained only in recognition judgments that featured recollective experience and were eliminated or reversed when recognition was not accompanied by recollective experience. It is proposed that conscious recollective experience in recognition memory is cued by attributes of retrieved memories such as sensory-perceptual attributes and records of cognitive operations performed at encoding.

ATM experiment S-056 image processing requirements definition

NASA Technical Reports Server (NTRS)

1972-01-01

A plan is presented for satisfying the image data processing needs of the S-056 Apollo Telescope Mount experiment. The report is based on information gathered from related technical publications, consultation with numerous image processing experts, and on the experience that was in working on related image processing tasks over a two-year period.

Imagery encoding and false recognition errors: Examining the role of imagery process and imagery content on source misattributions.

PubMed

Foley, Mary Ann; Foy, Jeffrey; Schlemmer, Emily; Belser-Ehrlich, Janna

2010-11-01

Imagery encoding effects on source-monitoring errors were explored using the Deese-Roediger-McDermott paradigm in two experiments. While viewing thematically related lists embedded in mixed picture/word presentations, participants were asked to generate images of objects or words (Experiment 1) or to simply name the items (Experiment 2). An encoding task intended to induce spontaneous images served as a control for the explicit imagery instruction conditions (Experiment 1). On the picture/word source-monitoring tests, participants were much more likely to report "seeing" a picture of an item presented as a word than the converse particularly when images were induced spontaneously. However, this picture misattribution error was reversed after generating images of words (Experiment 1) and was eliminated after simply labelling the items (Experiment 2). Thus source misattributions were sensitive to the processes giving rise to imagery experiences (spontaneous vs deliberate), the kinds of images generated (object vs word images), and the ways in which materials were presented (as pictures vs words).

Viewing experience and naturalness of 3D images

NASA Astrophysics Data System (ADS)

Seuntiëns, Pieter J.; Heynderickx, Ingrid E.; IJsselsteijn, Wijnand A.; van den Avoort, Paul M. J.; Berentsen, Jelle; Dalm, Iwan J.; Lambooij, Marc T.; Oosting, Willem

2005-11-01

The term 'image quality' is often used to measure the performance of an imaging system. Recent research showed however that image quality may not be the most appropriate term to capture the evaluative processes associated with experiencing 3D images. The added value of depth in 3D images is clearly recognized when viewers judge image quality of unimpaired 3D images against their 2D counterparts. However, when viewers are asked to rate image quality of impaired 2D and 3D images, the image quality results for both 2D and 3D images are mainly determined by the introduced artefacts, and the addition of depth in the 3D images is hardly accounted for. In this experiment we applied and tested the more general evaluative concepts of 'naturalness' and 'viewing experience'. It was hypothesized that these concepts would better reflect the added value of depth in 3D images. Four scenes were used varying in dimension (2D and 3D) and noise level (6 levels of white gaussian noise). Results showed that both viewing experience and naturalness were rated higher in 3D than in 2D when the same noise level was applied. Thus, the added value of depth is clearly demonstrated when the concepts of viewing experience and naturalness are being evaluated. The added value of 3D over 2D, expressed in noise level, was 2 dB for viewing experience and 4 dB for naturalness, indicating that naturalness appears the more sensitive evaluative concept for demonstrating the psychological impact of 3D displays.

Image dependency in the recognition of newly learnt faces.

PubMed

Longmore, Christopher A; Santos, Isabel M; Silva, Carlos F; Hall, Abi; Faloyin, Dipo; Little, Emily

2017-05-01

Research investigating the effect of lighting and viewpoint changes on unfamiliar and newly learnt faces has revealed that such recognition is highly image dependent and that changes in either of these leads to poor recognition accuracy. Three experiments are reported to extend these findings by examining the effect of apparent age on the recognition of newly learnt faces. Experiment 1 investigated the ability to generalize to novel ages of a face after learning a single image. It was found that recognition was best for the learnt image with performance falling the greater the dissimilarity between the study and test images. Experiments 2 and 3 examined whether learning two images aids subsequent recognition of a novel image. The results indicated that interpolation between two studied images (Experiment 2) provided some additional benefit over learning a single view, but that this did not extend to extrapolation (Experiment 3). The results from all studies suggest that recognition was driven primarily by pictorial codes and that the recognition of faces learnt from a limited number of sources operates on stored images of faces as opposed to more abstract, structural, representations.

The patient experience of high technology medical imaging: a systematic review of the qualitative evidence.

PubMed

Munn, Zachary; Jordan, Zoe

When presenting to an imaging department, the person who is to be imaged is often in a vulnerable state, and out of their comfort zone. It is the role of the medical imaging technician to produce a high quality image and facilitate patient care throughout the imaging process. Qualitative research is necessary to better inform the medical imaging technician and to help them to understand the experience of the person being imaged. Some issues that have been identified in the literature include fear, claustrophobia, dehumanisation, and an uncomfortable or unusual experience. There is now a small but worthwhile qualitative literature base focusing on the patient experience in high technology imaging. There is no current qualitative synthesis of the literature on the patient experience in high technology imaging. It is therefore timely and worthwhile to produce a systematic review to identify and summarise the existent literature exploring the patient experience of high technology imaging. To identify the patient experience of high technology medical imaging. Studies that were of a qualitative design that explored the phenomenon of interest, the patient experience of high technology medical imaging. Participants included anyone who had undergone one of these procedures. The search strategy aimed to find both published and unpublished studies, and was conducted over a period from June - September 2010. No time limits were imposed on this search strategy. A three-step search strategy was utilised in this review. All studies that met the criteria were selected for retrieval. They were then assessed by two independent reviewers for methodological validity prior to inclusion in the review using standardised critical appraisal instruments from the Joanna Briggs Institute Qualitative Assessment and Review Instrument. Data was extracted from papers included in the review using the standardised data extraction tool from the Joanna Briggs Institute Qualitative Assessment and Review Instrument. Research findings were pooled using the Qualitative Assessment and Review Instrument. Following the search and critical appraisal processes, 15 studies were identified that were deemed of suitable quality to be included in the review. From these 15 studies, 127 findings were extracted, forming 33 categories and 11 synthesised findings. These synthesised findings related to the patient experience, the emotions they felt (whether negative or positive), the need for support and information, and highlighted the importance of imaging to the patient. The synthesised findings in this review highlight the diverse, unique and challenging ways in which people experience imaging with MRI and CT scanners. All health professionals involved in imaging need to be aware of the different ways each patient may experience imaging, and provide them with ongoing support and information. The implications for practice are derived directly from the results of the meta-synthesis, and each of the 11 synthesised findings. There is still scope for further high methodological qualitative studies to be conducted in this field, particularly in the field of nuclear medicine imaging and Positron Emission Tomography. Further studies may be conducted in certain patient groups, and in certain age ranges. No studies were found assessing the experience of children undergoing high technology imaging.

Misleading first impressions: different for different facial images of the same person.

PubMed

Todorov, Alexander; Porter, Jenny M

2014-07-01

Studies on first impressions from facial appearance have rapidly proliferated in the past decade. Almost all of these studies have relied on a single face image per target individual, and differences in impressions have been interpreted as originating in stable physiognomic differences between individuals. Here we show that images of the same individual can lead to different impressions, with within-individual image variance comparable to or exceeding between-individuals variance for a variety of social judgments (Experiment 1). We further show that preferences for images shift as a function of the context (e.g., selecting an image for online dating vs. a political campaign; Experiment 2), that preferences are predictably biased by the selection of the images (e.g., an image fitting a political campaign vs. a randomly selected image; Experiment 3), and that these biases are evident after extremely brief (40-ms) presentation of the images (Experiment 4). We discuss the implications of these findings for studies on the accuracy of first impressions. © The Author(s) 2014.

Developing Students' Ideas about Lens Imaging: Teaching Experiments with an Image-Based Approach

ERIC Educational Resources Information Center

Grusche, Sascha

2017-01-01

Lens imaging is a classic topic in physics education. To guide students from their holistic viewpoint to the scientists' analytic viewpoint, an image-based approach to lens imaging has recently been proposed. To study the effect of the image-based approach on undergraduate students' ideas, teaching experiments are performed and evaluated using…

The meaning of body image experiences during the perinatal period: A systematic review of the qualitative literature.

PubMed

Watson, Brittany; Fuller-Tyszkiewicz, Matthew; Broadbent, Jaclyn; Skouteris, Helen

2015-06-01

Literature reporting body image disturbances across the perinatal period has produced inconsistent findings, owing to the complexity of body image experiences during pregnancy and the first year postpartum. Existing qualitative data might provide potential avenues to advance understanding of pregnancy-related body image experiences and guide future quantitative research. The present systematic review synthesised the findings of 10 qualitative studies exploring the body image experiences of women through the perinatal period, albeit the majority focused only on pregnancy. Themes emerging included malleability of body image ideals across pregnancy (including the shift from aesthetic to functional concerns about one's appearance), the salience of stomach and breasts for self-rated body satisfaction, and perceived pressure to limit weight gain across pregnancy in order to return quickly to pre-pregnancy figure following birth. These qualitative findings suggest greater complexity of body image experiences during perinatal period than can be captured by typically used self-report measures. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Analyses of requirements for computer control and data processing experiment subsystems. Volume 1: ATM experiment S-056 image data processing system techniques development

NASA Technical Reports Server (NTRS)

1972-01-01

The solar imaging X-ray telescope experiment (designated the S-056 experiment) is described. It will photograph the sun in the far ultraviolet or soft X-ray region. Because of the imaging characteristics of this telescope and the necessity of using special techniques for capturing images on film at these wave lengths, methods were developed for computer processing of the photographs. The problems of image restoration were addressed to develop and test digital computer techniques for applying a deconvolution process to restore overall S-056 image quality. Additional techniques for reducing or eliminating the effects of noise and nonlinearity in S-056 photographs were developed.

Objected-oriented remote sensing image classification method based on geographic ontology model

NASA Astrophysics Data System (ADS)

Chu, Z.; Liu, Z. J.; Gu, H. Y.

2016-11-01

Nowadays, with the development of high resolution remote sensing image and the wide application of laser point cloud data, proceeding objected-oriented remote sensing classification based on the characteristic knowledge of multi-source spatial data has been an important trend on the field of remote sensing image classification, which gradually replaced the traditional method through improving algorithm to optimize image classification results. For this purpose, the paper puts forward a remote sensing image classification method that uses the he characteristic knowledge of multi-source spatial data to build the geographic ontology semantic network model, and carries out the objected-oriented classification experiment to implement urban features classification, the experiment uses protégé software which is developed by Stanford University in the United States, and intelligent image analysis software—eCognition software as the experiment platform, uses hyperspectral image and Lidar data that is obtained through flight in DaFeng City of JiangSu as the main data source, first of all, the experiment uses hyperspectral image to obtain feature knowledge of remote sensing image and related special index, the second, the experiment uses Lidar data to generate nDSM(Normalized DSM, Normalized Digital Surface Model),obtaining elevation information, the last, the experiment bases image feature knowledge, special index and elevation information to build the geographic ontology semantic network model that implement urban features classification, the experiment results show that, this method is significantly higher than the traditional classification algorithm on classification accuracy, especially it performs more evidently on the respect of building classification. The method not only considers the advantage of multi-source spatial data, for example, remote sensing image, Lidar data and so on, but also realizes multi-source spatial data knowledge integration and application of the knowledge to the field of remote sensing image classification, which provides an effective way for objected-oriented remote sensing image classification in the future.

Breaking Be: a sterile neutrino solution to the cosmological lithium problem

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salvati, L.; Melchiorri, A.; Pagano, L.

2016-08-01

The possibility that the so-called ''lithium problem'', i.e., the disagreement between the theoretical abundance predicted for primordial {sup 7}Li assuming standard nucleosynthesis and the value inferred from astrophysical measurements, can be solved through a non-thermal Big Bang Nucleosynthesis (BBN) mechanism has been investigated by several authors. In particular, it has been shown that the decay of a MeV-mass particle, like, e.g., a sterile neutrino, decaying after BBN not only solves the lithium problem, but also satisfies cosmological and laboratory bounds, making such a scenario worth to be investigated in further detail. In this paper, we constrain the parameters of themore » model with the combination of current data, including Planck 2015 measurements of temperature and polarization anisotropies of the Cosmic Microwave Background (CMB), FIRAS limits on CMB spectral distortions, astrophysical measurements of primordial abundances and laboratory constraints. We find that a sterile neutrino with mass M {sub S} = 4.35{sub -0.17}{sup +0.13} MeV (at 95% c.l.), a decay time τ {sub S} = 1.8{sub -1.3}{sup +2.5} · 10{sup 5} s (at 95% c.l.) and an initial density n-bar {sub S} / n-bar {sub cmb} = 1.7{sub -0.6}{sup +3.5} · 10{sup -4} (at 95% c.l.) in units of the number density of CMB photons, perfectly accounts for the difference between predicted and observed {sup 7}Li primordial abundance. This model also predicts an increase of the effective number of relativistic degrees of freedom at the time of CMB decoupling Δ N {sub eff}{sup cmb} ≡ N {sub eff}{sup cmb} -3.046 = 0.34{sub -0.14}{sup +0.16} at 95% c.l.. The required abundance of sterile neutrinos is incompatible with the standard thermal history of the Universe, but could be realized in a low reheating temperature scenario. We also provide forecasts for future experiments finding that the combination of measurements from the COrE+ and PIXIE missions will allow to significantly reduce the permitted region for the sterile lifetime and density.« less

Cosmological constraints on exotic injection of electromagnetic energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poulin, Vivian; Serpico, Pasquale D.; Lesgourgues, Julien, E-mail: Vivian.Poulin@lapth.cnrs.fr, E-mail: Pasquale.Serpico@lapth.cnrs.fr, E-mail: Julien.Lesgourgues@physik.rwth-aachen.de

We compute cosmic microwave background (CMB) anisotropy constraints on exotic forms of energy injection in electromagnetic (e.m.) channels over a large range of timescales. We show that these constraints are very powerful around or just after recombination, although CMB keeps some sensitivity e.g. to decaying species with lifetimes as long as 10{sup 25} s. These bounds are complementary to CMB spectral distortions and primordial nucleosynthesis ones, which dominate at earlier timescales, as we also review here. For the first time, we describe the effects of the e.m. energy injection on the CMB power spectra as a function of the injectionmore » epoch , using the lifetime of a decaying particle as proxy. We also identify a suitable on-the-spot approximation, that can be used to derive accurate constraints, and describe its differences with the most up-to-date treatment. Our results are of interest not only for early universe relics constituting (a fraction of) the dark matter, but also for other exotic injection of e.m. radiation. For illustration, we apply our formalism to: i) Primordial black holes of mass 10{sup 13.5} g ∼< M ∼< 10{sup 16.8} g, showing that the constraints are comparable to the ones obtained from gamma-ray background studies and even dominate below ∼ 10{sup 14} g. ii) To a peculiar mass-mixing range in the sterile neutrino parameter space, complementary to other astrophysical and laboratory probes. iii) Finally, we provide a first estimate of the room for improvement left for forthcoming 21 cm experiments, comparing it with the reach of proposed CMB spectral distortion (PiXiE) and CMB angular power spectrum (CORE) missions. We show that the best and most realistic opportunity to look for this signal (or to improve over current constraints) in the 21 cm probe is to focus on the Cosmic Dawn epoch, 15 ∼< z ∼< 30, where the qualitatively unambiguous signature of a spectrum in emission can be expected for models that evade all current constraints.« less

The effects of the small-scale behaviour of dark matter power spectrum on CMB spectral distortion

NASA Astrophysics Data System (ADS)

Sarkar, Abir; Sethi, Shiv. K.; Das, Subinoy

2017-07-01

After numerous astronomical and experimental searches, the precise particle nature of dark matter is still unknown. The standard Weakly Interacting Massive Particle(WIMP) dark matter, despite successfully explaining the large-scale features of the universe, has long-standing small-scale issues. The spectral distortion in the Cosmic Microwave Background(CMB) caused by Silk damping in the pre-recombination era allows one to access information on a range of small scales 0.3 Mpc < k < 104 Mpc-1, whose dynamics can be precisely described using linear theory. In this paper, we investigate the possibility of using the Silk damping induced CMB spectral distortion as a probe of the small-scale power. We consider four suggested alternative dark matter candidates—Warm Dark Matter (WDM), Late Forming Dark Matter (LFDM), Ultra Light Axion (ULA) dark matter and Charged Decaying Dark Matter (CHDM); the matter power in all these models deviate significantly from the ΛCDM model at small scales. We compute the spectral distortion of CMB for these alternative models and compare our results with the ΛCDM model. We show that the main impact of alternative models is to alter the sub-horizon evolution of the Newtonian potential which affects the late-time behaviour of spectral distortion of CMB. The y-parameter diminishes by a few percent as compared to the ΛCDM model for a range of parameters of these models: LFDM for formation redshift zf = 105 (7%); WDM for mass mwdm = 1 keV (2%); CHDM for decay redshift zdecay = 105 (5%); ULA for mass ma = 10-24 eV (3%). This effect from the pre-recombination era can be masked by orders of magnitude higher y-distortions generated by late-time sources, e.g. the Epoch of Reionization and tSZ from the cluster of galaxies. We also briefly discuss the detectability of this deviation in light of the upcoming CMB experiment PIXIE, which might have the sensitivity to detect this signal from the pre-recombination phase.

The effects of the small-scale behaviour of dark matter power spectrum on CMB spectral distortion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sarkar, Abir; Sethi, Shiv K.; Das, Subinoy, E-mail: abir@rri.res.in, E-mail: sethi@rri.res.in, E-mail: subinoy@iiap.res.in

After numerous astronomical and experimental searches, the precise particle nature of dark matter is still unknown. The standard Weakly Interacting Massive Particle(WIMP) dark matter, despite successfully explaining the large-scale features of the universe, has long-standing small-scale issues. The spectral distortion in the Cosmic Microwave Background(CMB) caused by Silk damping in the pre-recombination era allows one to access information on a range of small scales 0.3 Mpc < k < 10{sup 4} Mpc{sup −1}, whose dynamics can be precisely described using linear theory. In this paper, we investigate the possibility of using the Silk damping induced CMB spectral distortion as amore » probe of the small-scale power. We consider four suggested alternative dark matter candidates—Warm Dark Matter (WDM), Late Forming Dark Matter (LFDM), Ultra Light Axion (ULA) dark matter and Charged Decaying Dark Matter (CHDM); the matter power in all these models deviate significantly from the ΛCDM model at small scales. We compute the spectral distortion of CMB for these alternative models and compare our results with the ΛCDM model. We show that the main impact of alternative models is to alter the sub-horizon evolution of the Newtonian potential which affects the late-time behaviour of spectral distortion of CMB. The y -parameter diminishes by a few percent as compared to the ΛCDM model for a range of parameters of these models: LFDM for formation redshift z {sub f} = 10{sup 5} (7%); WDM for mass m {sub wdm} = 1 keV (2%); CHDM for decay redshift z {sub decay} = 10{sup 5} (5%); ULA for mass m {sub a} = 10{sup −24} eV (3%). This effect from the pre-recombination era can be masked by orders of magnitude higher y -distortions generated by late-time sources, e.g. the Epoch of Reionization and tSZ from the cluster of galaxies. We also briefly discuss the detectability of this deviation in light of the upcoming CMB experiment PIXIE, which might have the sensitivity to detect this signal from the pre-recombination phase.« less

Remote Sensing Image Quality Assessment Experiment with Post-Processing

NASA Astrophysics Data System (ADS)

Jiang, W.; Chen, S.; Wang, X.; Huang, Q.; Shi, H.; Man, Y.

2018-04-01

This paper briefly describes the post-processing influence assessment experiment, the experiment includes three steps: the physical simulation, image processing, and image quality assessment. The physical simulation models sampled imaging system in laboratory, the imaging system parameters are tested, the digital image serving as image processing input are produced by this imaging system with the same imaging system parameters. The gathered optical sampled images with the tested imaging parameters are processed by 3 digital image processes, including calibration pre-processing, lossy compression with different compression ratio and image post-processing with different core. Image quality assessment method used is just noticeable difference (JND) subject assessment based on ISO20462, through subject assessment of the gathered and processing images, the influence of different imaging parameters and post-processing to image quality can be found. The six JND subject assessment experimental data can be validated each other. Main conclusions include: image post-processing can improve image quality; image post-processing can improve image quality even with lossy compression, image quality with higher compression ratio improves less than lower ratio; with our image post-processing method, image quality is better, when camera MTF being within a small range.

Cultivation of Tomato Tissues Capable of Forming Flowers and Fruits in Vitro

NASA Technical Reports Server (NTRS)

Galston, Arthur W.

1998-01-01

The final phase of this research project was designed to develop a practical method for producing a steady supply of fresh cherry tomato fruits over a period of several months, for possible use as a fresh vegetable supplement to a standard diet of astronauts on extended missions. This effort was successful. We were able to excise immature flowers from Pixie tomato plants grown in a controlled condition room, implant them on artificial media under aseptic conditions, and get them to develop into edible fruits in a little over a month. The medium (Murashige-Skoog) was purchased from Sigma, supplemented with sugar plus a synthetic analog of the plant hormone cytokinin, and adjusted to pH 5.8. A temperature of at least 25 C and visible light helped to produce ripe red fruits within 7 weeks. To ensure a steady supply of such tomatoes, we found it possible to store the explanted flower buds in MS medium at 5 C for at least 6 weeks without significant loss of ability to develop into fruits. This means that many containers could be prepared before launch and put into a refrigerator; a convenient number could then be removed periodically to guarantee a succession of harvests during the life of an extended mission. Details are found in the attached reprints. Subsequent applications for funds for flight or continued research were denied, and the project was terminated.

Clock and trigger synchronization between several chassis of digital data acquisition modules

NASA Astrophysics Data System (ADS)

Hennig, W.; Tan, H.; Walby, M.; Grudberg, P.; Fallu-Labruyere, A.; Warburton, W. K.; Vaman, C.; Starosta, K.; Miller, D.

2007-08-01

In applications with segmented high purity Ge detectors or other detector arrays with tens or hundreds of channels, the high development cost and limited flexibility of application specific integrated circuits outweigh their benefits of low power and small size. The readout electronics typically consist of multi-channel data acquisition modules in a common chassis for power, clock and trigger distribution, and data readout. As arrays become larger and reach several hundred channels, the readout electronics have to be divided over several chassis, but still must maintain precise synchronization of clocks and trigger signals across all channels. This division becomes necessary not only because of limits given by the instrumentation standards on module size and chassis slot numbers, but also because data readout times increase when more modules share the same data bus and because power requirements approach the limits of readily available power supplies. In this paper, we present a method for distributing clocks and triggers between 4 PXI chassis containing DGF Pixie-16 modules with up to 226 acquisition channels per chassis. The data acquisition system is intended to instrument the over 600 channels of the SeGA detector array at the National Superconducting Cyclotron Laboratory. Our solution is designed to achieve synchronous acquisition of detector waveforms from all channels with a jitter of less than 1 ns, and can be extended to a larger number of chassis if desired.

Design of an automated imaging system for use in a space experiment

NASA Technical Reports Server (NTRS)

Hartz, William G.; Bozzolo, Nora G.; Lewis, Catherine C.; Pestak, Christopher J.

1991-01-01

An experiment, occurring in an orbiting platform, examines the mass transfer across gas-liquid and liquid-liquid interfaces. It employs an imaging system with real time image analysis. The design includes optical design, imager selection and integration, positioner control, image recording, software development for processing and interfaces to telemetry. It addresses the constraints of weight, volume, and electric power associated with placing the experiment in the Space Shuttle cargo bay. Challenging elements of the design are: imaging and recording of a 200-micron-diameter bubble with a resolution of 2 microns to serve a primary source of data; varying frame rates from 500 per second to 1 frame per second, depending on the experiment phase; and providing three-dimensional information to determine the shape of the bubble.

Better safe than sorry: simplistic fear-relevant stimuli capture attention.

PubMed

Forbes, Sarah J; Purkis, Helena M; Lipp, Ottmar V

2011-08-01

It has been consistently demonstrated that fear-relevant images capture attention preferentially over fear-irrelevant images. Current theory suggests that this faster processing could be mediated by an evolved module that allows certain stimulus features to attract attention automatically, prior to the detailed processing of the image. The present research investigated whether simplified images of fear-relevant stimuli would produce interference with target detection in a visual search task. In Experiment 1, silhouettes and degraded silhouettes of fear-relevant animals produced more interference than did the fear-irrelevant images. Experiment 2, compared the effects of fear-relevant and fear-irrelevant distracters and confirmed that the interference produced by fear-relevant distracters was not an effect of novelty. Experiment 3 suggested that fear-relevant stimuli produced interference regardless of whether participants were instructed as to the content of the images. The three experiments indicate that even very simplistic images of fear-relevant animals can divert attention.

Attention to local and global levels of hierarchical Navon figures affects rapid scene categorization.

PubMed

Brand, John; Johnson, Aaron P

2014-01-01

In four experiments, we investigated how attention to local and global levels of hierarchical Navon figures affected the selection of diagnostic spatial scale information used in scene categorization. We explored this issue by asking observers to classify hybrid images (i.e., images that contain low spatial frequency (LSF) content of one image, and high spatial frequency (HSF) content from a second image) immediately following global and local Navon tasks. Hybrid images can be classified according to either their LSF, or HSF content; thus, making them ideal for investigating diagnostic spatial scale preference. Although observers were sensitive to both spatial scales (Experiment 1), they overwhelmingly preferred to classify hybrids based on LSF content (Experiment 2). In Experiment 3, we demonstrated that LSF based hybrid categorization was faster following global Navon tasks, suggesting that LSF processing associated with global Navon tasks primed the selection of LSFs in hybrid images. In Experiment 4, replicating Experiment 3 but suppressing the LSF information in Navon letters by contrast balancing the stimuli examined this hypothesis. Similar to Experiment 3, observers preferred to classify hybrids based on LSF content; however and in contrast, LSF based hybrid categorization was slower following global than local Navon tasks.

Attention to local and global levels of hierarchical Navon figures affects rapid scene categorization

PubMed Central

Brand, John; Johnson, Aaron P.

2014-01-01

In four experiments, we investigated how attention to local and global levels of hierarchical Navon figures affected the selection of diagnostic spatial scale information used in scene categorization. We explored this issue by asking observers to classify hybrid images (i.e., images that contain low spatial frequency (LSF) content of one image, and high spatial frequency (HSF) content from a second image) immediately following global and local Navon tasks. Hybrid images can be classified according to either their LSF, or HSF content; thus, making them ideal for investigating diagnostic spatial scale preference. Although observers were sensitive to both spatial scales (Experiment 1), they overwhelmingly preferred to classify hybrids based on LSF content (Experiment 2). In Experiment 3, we demonstrated that LSF based hybrid categorization was faster following global Navon tasks, suggesting that LSF processing associated with global Navon tasks primed the selection of LSFs in hybrid images. In Experiment 4, replicating Experiment 3 but suppressing the LSF information in Navon letters by contrast balancing the stimuli examined this hypothesis. Similar to Experiment 3, observers preferred to classify hybrids based on LSF content; however and in contrast, LSF based hybrid categorization was slower following global than local Navon tasks. PMID:25520675

Effects of Resolution, Range, and Image Contrast on Target Acquisition Performance.

PubMed

Hollands, Justin G; Terhaar, Phil; Pavlovic, Nada J

2018-05-01

We sought to determine the joint influence of resolution, target range, and image contrast on the detection and identification of targets in simulated naturalistic scenes. Resolution requirements for target acquisition have been developed based on threshold values obtained using imaging systems, when target range was fixed, and image characteristics were determined by the system. Subsequent work has examined the influence of factors like target range and image contrast on target acquisition. We varied the resolution and contrast of static images in two experiments. Participants (soldiers) decided whether a human target was located in the scene (detection task) or whether a target was friendly or hostile (identification task). Target range was also varied (50-400 m). In Experiment 1, 30 participants saw color images with a single target exemplar. In Experiment 2, another 30 participants saw monochrome images containing different target exemplars. The effects of target range and image contrast were qualitatively different above and below 6 pixels per meter of target for both tasks in both experiments. Target detection and identification performance were a joint function of image resolution, range, and contrast for both color and monochrome images. The beneficial effects of increasing resolution for target acquisition performance are greater for closer (larger) targets.

Experiences with digital processing of images at INPE

NASA Technical Reports Server (NTRS)

Mascarenhas, N. D. A. (Principal Investigator)

1984-01-01

Four different research experiments with digital image processing at INPE will be described: (1) edge detection by hypothesis testing; (2) image interpolation by finite impulse response filters; (3) spatial feature extraction methods in multispectral classification; and (4) translational image registration by sequential tests of hypotheses.

The Native American Experience. American Historical Images on File.

ERIC Educational Resources Information Center

Wardwell, Lelia, Ed.

This photo-documentation reference body presents more than 275 images chronicling the experiences of the American Indian from their prehistoric migrations to the present. The volume includes information and images illustrating the life ways of various tribes. The images are accompanied by historical information providing cultural context. The book…

Using an NMR Spectrometer to Do Magnetic Resonance Imaging: An Undergraduate Physical Chemistry Laboratory Experiment

ERIC Educational Resources Information Center

Steinmetz, Wayne E.; Maher, M. Cyrus

2007-01-01

A conventional Fourier-transform NMR spectrometer with a triple-axis gradient probe can function as a MRI imager. In this experiment students gain hands-on experience with MRI while they learn about important principles underlying the practice of NMR, such as gradients, multi-dimensional spectroscopy, and relaxation. Students image a biological…

Multispectral breast imaging using a ten-wavelength, 64 x 64 source/detector channels silicon photodiode-based diffuse optical tomography system.

PubMed

Li, Changqing; Zhao, Hongzhi; Anderson, Bonnie; Jiang, Huabei

2006-03-01

We describe a compact diffuse optical tomography system specifically designed for breast imaging. The system consists of 64 silicon photodiode detectors, 64 excitation points, and 10 diode lasers in the near-infrared region, allowing multispectral, three-dimensional optical imaging of breast tissue. We also detail the system performance and optimization through a calibration procedure. The system is evaluated using tissue-like phantom experiments and an in vivo clinic experiment. Quantitative two-dimensional (2D) and three-dimensional (3D) images of absorption and reduced scattering coefficients are obtained from these experiments. The ten-wavelength spectra of the extracted reduced scattering coefficient enable quantitative morphological images to be reconstructed with this system. From the in vivo clinic experiment, functional images including deoxyhemoglobin, oxyhemoglobin, and water concentration are recovered and tumors are detected with correct size and position compared with the mammography.

Detection of latent fingerprints by ultraviolet spectral imaging

NASA Astrophysics Data System (ADS)

Huang, Wei; Xu, Xiaojing; Wang, Guiqiang

2013-12-01

Spectral imaging technology research is becoming more popular in the field of forensic science. Ultraviolet spectral imaging technology is an especial part of the full spectrum of imaging technology. This paper finished the experiment contents of the ultraviolet spectrum imaging method and image acquisition system based on ultraviolet spectral imaging technology. Ultraviolet spectral imaging experiments explores a wide variety of ultraviolet reflectance spectra of the object material curve and its ultraviolet spectrum of imaging modalities, can not only gives a reference for choosing ultraviolet wavelength to show the object surface potential traces of substances, but also gives important data for the ultraviolet spectrum of imaging technology development.

The relationship study between image features and detection probability based on psychology experiments

NASA Astrophysics Data System (ADS)

Lin, Wei; Chen, Yu-hua; Wang, Ji-yuan; Gao, Hong-sheng; Wang, Ji-jun; Su, Rong-hua; Mao, Wei

2011-04-01

Detection probability is an important index to represent and estimate target viability, which provides basis for target recognition and decision-making. But it will expend a mass of time and manpower to obtain detection probability in reality. At the same time, due to the different interpretation of personnel practice knowledge and experience, a great difference will often exist in the datum obtained. By means of studying the relationship between image features and perception quantity based on psychology experiments, the probability model has been established, in which the process is as following.Firstly, four image features have been extracted and quantified, which affect directly detection. Four feature similarity degrees between target and background were defined. Secondly, the relationship between single image feature similarity degree and perception quantity was set up based on psychological principle, and psychological experiments of target interpretation were designed which includes about five hundred people for interpretation and two hundred images. In order to reduce image features correlativity, a lot of artificial synthesis images have been made which include images with single brightness feature difference, images with single chromaticity feature difference, images with single texture feature difference and images with single shape feature difference. By analyzing and fitting a mass of experiments datum, the model quantitys have been determined. Finally, by applying statistical decision theory and experimental results, the relationship between perception quantity with target detection probability has been found. With the verification of a great deal of target interpretation in practice, the target detection probability can be obtained by the model quickly and objectively.

A qualitative exploration of body image experiences of women progressing through pregnancy.

PubMed

Watson, Brittany; Broadbent, Jaclyn; Skouteris, Helen; Fuller-Tyszkiewicz, Matthew

2016-02-01

Pregnancy provides an interesting challenge to body image theories in that the natural physiological changes push women further from the socioculturally prescribed thin ideal which these theories hinge upon. The impact that these significant physiological changes have on the woman's body image during pregnancy may depend on the extent to which they retain or revise the ideal. However, little is known about body image experiences during pregnancy. To provide a comprehensive exploration of the body image experiences of pregnant women. Individual structured interviews were conducted with 19 currently pregnant women. Transcriptions were analysed using a thematic content analysis approach. Themes extracted from the qualitative data included: (1) women's body image experiences during pregnancy were complex and changing, and shaped by the salience of specific body parts, the women's expectations for future changes to their body within the perinatal period, the functionality of the body, and their experience of maternity clothing, (2) women were able to negotiate the changes to their bodies as they recognised the functionality of the pregnant body, (3) women were surprised by the public nature of the pregnant body, (4) partner support and positive feedback about the pregnant body was highly valued, and (5) the importance of open communication around weight and body image in antenatal healthcare. Our findings highlight the need for the adaptation and expansion of existing body image theories to be used as a framework for women's experiences of pregnancy. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Responses of chimpanzees to cues of conspecific observation☆

PubMed Central

Nettle, Daniel; Cronin, Katherine A.; Bateson, Melissa

2013-01-01

Recent evidence has shown that humans are remarkably sensitive to artificial cues of conspecific observation when making decisions with potential social consequences. Whether similar effects are found in other great apes has not yet been investigated. We carried out two experiments in which individual chimpanzees, Pan troglodytes, took items of food from an array in the presence of either an image of a large conspecific face or a scrambled control image. In experiment 1 we compared three versions of the face image varying in size and the amount of the face displayed. In experiment 2 we compared a fourth variant of the image with more prominent coloured eyes displayed closer to the focal chimpanzee. The chimpanzees did not look at the face images significantly more than at the control images in either experiment. Although there were trends for some individuals in each experiment to be slower to take high-value food items in the face conditions, these were not consistent or robust. We suggest that the extreme human sensitivity to cues of potential conspecific observation may not be shared with chimpanzees. PMID:24027343

Evaluation of SIR-A (Shuttle Imaging Radar) images from the Tres Marias region (Minas Gerais State, Brazil) using derived spatial features and registration with MSS-LANDSAT images

NASA Technical Reports Server (NTRS)

Parada, N. D. J. (Principal Investigator); Kux, H. J. H.; Dutra, L. V.

1984-01-01

Two image processing experiments are described using a MSS-LANDSAT scene from the Tres Marias region and a shuttle Imaging Radar SIR-A image digitized by a vidicon scanner. In the first experiment the study area is analyzed using the original and preprocessed SIR-A image data. The following thematic classes are obtained: (1) water, (2) dense savanna vegetation, (3) sparse savanna vegetation, (4) reforestation areas and (5) bare soil areas. In the second experiment, the SIR-A image was registered together with MSS-LANDSAT bands five, six, and seven. The same five classes mentioned above are obtained. These results are compared with those obtained using solely MSS-LANDSAT data. The spatial information as well as coregistered SIR-A and MSS-LANDSAT data can increase the separability between classes, as compared to the use of raw SIR-A data solely.

Measurement of fetal head descent using the 'angle of progression' on transperineal ultrasound imaging is reliable regardless of fetal head station or ultrasound expertise.

PubMed

Dückelmann, A M; Bamberg, C; Michaelis, S A M; Lange, J; Nonnenmacher, A; Dudenhausen, J W; Kalache, K D

2010-02-01

To assess whether ultrasound experience or fetal head station affects the reliability of measurement of fetal head descent using the angle of progression on intrapartum ultrasound images obtained by a single experienced operator, and to determine reliability of measurements when images were acquired by different operators with variable ultrasound experience. One experienced obstetrician performed 44 transperineal ultrasound examinations of women at term and in prolonged second stage of labor with the fetus in the occipitoanterior position. Three midwives without ultrasound experience, three obstetricians with < 5 years' experience and three obstetricians with > 10 years' experience measured fetal head descent based on the angle of progression in the images obtained. The angle of progression was measured by two obstetricians in independent ultrasound examinations of 24 laboring women at term with the fetus in the cephalic position to allow assessment of the reliability of image acquisition. Intraclass correlation coefficients (ICCs) with 95% confidence interval (CI) were used to evaluate interobserver reliability and Bland-Altman analysis was used to assess interobserver agreement. In total, 444 measurements were performed and compared. Interobserver reliability with respect to offline image analysis was substantial (overall ICC, 0.72; 95% CI, 0.63-0.81). ICCs were 0.82 (95% CI, 0.70-0.89), 0.81 (95% CI, 0.71-0.88) and 0.61 (95% CI, 0.43-074) for observers with > 10 years', < 5 years' and no ultrasound experience, respectively. There were no significant differences between ICCs among observer groups according to ultrasound experience. Fetal head station did not affect reliability. Bland-Altman analysis indicated reasonable agreement between measurements obtained by two different operators with > 10 years' and < 5 years' ultrasound experience (bias, -1.09 degrees ; 95% limits of agreement, -8.76 to 6.58). The reliability of measurement of the angle of progression following separate image acquisition by two experienced operators was similar to the reliability of offline image analysis (ICC, 0.86; 95% CI, 0.70-0.93). Measurement of the angle of progression on transperineal ultrasound imaging is reliable regardless of fetal head station or the clinician's level of ultrasound experience.

HICO and RAIDS Experiment Payload - Hyperspectral Imager for the Coastal Ocean

NASA Technical Reports Server (NTRS)

Corson, Mike

2009-01-01

HICO and RAIDS Experiment Payload - Hyperspectral Imager For The Coastal Ocean (HREP-HICO) will operate a visible and near-infrared (VNIR) Maritime Hyperspectral Imaging (MHSI) system, to detect, identify and quantify coastal geophysical features from the International Space Station.

Toward an implicit measure of emotions: ratings of abstract images reveal distinct emotional states.

PubMed

Bartoszek, Gregory; Cervone, Daniel

2017-11-01

Although implicit tests of positive and negative affect exist, implicit measures of distinct emotional states are scarce. Three experiments examined whether a novel implicit emotion-assessment task, the rating of emotion expressed in abstract images, would reveal distinct emotional states. In Experiment 1, participants exposed to a sadness-inducing story inferred more sadness, and less happiness, in abstract images. In Experiment 2, an anger-provoking interaction increased anger ratings. In Experiment 3, compared to neutral images, spider images increased fear ratings in spider-fearful participants but not in controls. In each experiment, the implicit task indicated elevated levels of the target emotion and did not indicate elevated levels of non-target negative emotions; the task thus differentiated among emotional states of the same valence. Correlations also supported the convergent and discriminant validity of the implicit task. Supporting the possibility that heuristic processes underlie the ratings, group differences were stronger among those who responded relatively quickly.

Not All Faces Are Processed Equally: Evidence for Featural Rather than Holistic Processing of One's Own Face in a Face-Imaging Task

ERIC Educational Resources Information Center

Greenberg, Seth N.; Goshen-Gottstein, Yonatan

2009-01-01

The present work considers the mental imaging of faces, with a focus in own-face imaging. Experiments 1 and 3 demonstrated an own-face disadvantage, with slower generation of mental images of one's own face than of other familiar faces. In contrast, Experiment 2 demonstrated that mental images of facial parts are generated more quickly for one's…

MISR Browse Images: Puerto Rico Dust Experiment (PRiDE)

Atmospheric Science Data Center

2013-04-02

MISR Browse Images: Puerto Rico Dust Experiment (PRiDE) These MISR Browse ... a quick visual overview of the region observed during the Puerto Rico Dust Experiment (PRiDE) field campaign. PRiDE was a study of the ...

Performance test and image correction of CMOS image sensor in radiation environment

NASA Astrophysics Data System (ADS)

Wang, Congzheng; Hu, Song; Gao, Chunming; Feng, Chang

2016-09-01

CMOS image sensors rival CCDs in domains that include strong radiation resistance as well as simple drive signals, so it is widely applied in the high-energy radiation environment, such as space optical imaging application and video monitoring of nuclear power equipment. However, the silicon material of CMOS image sensors has the ionizing dose effect in the high-energy rays, and then the indicators of image sensors, such as signal noise ratio (SNR), non-uniformity (NU) and bad point (BP) are degraded because of the radiation. The radiation environment of test experiments was generated by the 60Co γ-rays source. The camera module based on image sensor CMV2000 from CMOSIS Inc. was chosen as the research object. The ray dose used for the experiments was with a dose rate of 20krad/h. In the test experiences, the output signals of the pixels of image sensor were measured on the different total dose. The results of data analysis showed that with the accumulation of irradiation dose, SNR of image sensors decreased, NU of sensors was enhanced, and the number of BP increased. The indicators correction of image sensors was necessary, as it was the main factors to image quality. The image processing arithmetic was adopt to the data from the experiences in the work, which combined local threshold method with NU correction based on non-local means (NLM) method. The results from image processing showed that image correction can effectively inhibit the BP, improve the SNR, and reduce the NU.

Birdcage volume coils and magnetic resonance imaging: a simple experiment for students.

PubMed

Vincent, Dwight E; Wang, Tianhao; Magyar, Thalia A K; Jacob, Peni I; Buist, Richard; Martin, Melanie

2017-01-01

This article explains some simple experiments that can be used in undergraduate or graduate physics or biomedical engineering laboratory classes to learn how birdcage volume radiofrequency (RF) coils and magnetic resonance imaging (MRI) work. For a clear picture, and to do any quantitative MRI analysis, acquiring images with a high signal-to-noise ratio (SNR) is required. With a given MRI system at a given field strength, the only means to change the SNR using hardware is to change the RF coil used to collect the image. RF coils can be designed in many different ways including birdcage volume RF coil designs. The choice of RF coil to give the best SNR for any MRI study is based on the sample being imaged. The data collected in the simple experiments show that the SNR varies as inverse diameter for the birdcage volume RF coils used in these experiments. The experiments were easily performed by a high school student, an undergraduate student, and a graduate student, in less than 3 h, the time typically allotted for a university laboratory course. The article describes experiments that students in undergraduate or graduate laboratories can perform to observe how birdcage volume RF coils influence MRI measurements. It is designed for students interested in pursuing careers in the imaging field.

What you see is what you expect: rapid scene understanding benefits from prior experience.

PubMed

Greene, Michelle R; Botros, Abraham P; Beck, Diane M; Fei-Fei, Li

2015-05-01

Although we are able to rapidly understand novel scene images, little is known about the mechanisms that support this ability. Theories of optimal coding assert that prior visual experience can be used to ease the computational burden of visual processing. A consequence of this idea is that more probable visual inputs should be facilitated relative to more unlikely stimuli. In three experiments, we compared the perceptions of highly improbable real-world scenes (e.g., an underwater press conference) with common images matched for visual and semantic features. Although the two groups of images could not be distinguished by their low-level visual features, we found profound deficits related to the improbable images: Observers wrote poorer descriptions of these images (Exp. 1), had difficulties classifying the images as unusual (Exp. 2), and even had lower sensitivity to detect these images in noise than to detect their more probable counterparts (Exp. 3). Taken together, these results place a limit on our abilities for rapid scene perception and suggest that perception is facilitated by prior visual experience.

Adapting Local Features for Face Detection in Thermal Image.

PubMed

Ma, Chao; Trung, Ngo Thanh; Uchiyama, Hideaki; Nagahara, Hajime; Shimada, Atsushi; Taniguchi, Rin-Ichiro

2017-11-27

A thermal camera captures the temperature distribution of a scene as a thermal image. In thermal images, facial appearances of different people under different lighting conditions are similar. This is because facial temperature distribution is generally constant and not affected by lighting condition. This similarity in face appearances is advantageous for face detection. To detect faces in thermal images, cascade classifiers with Haar-like features are generally used. However, there are few studies exploring the local features for face detection in thermal images. In this paper, we introduce two approaches relying on local features for face detection in thermal images. First, we create new feature types by extending Multi-Block LBP. We consider a margin around the reference and the generally constant distribution of facial temperature. In this way, we make the features more robust to image noise and more effective for face detection in thermal images. Second, we propose an AdaBoost-based training method to get cascade classifiers with multiple types of local features. These feature types have different advantages. In this way we enhance the description power of local features. We did a hold-out validation experiment and a field experiment. In the hold-out validation experiment, we captured a dataset from 20 participants, comprising 14 males and 6 females. For each participant, we captured 420 images with 10 variations in camera distance, 21 poses, and 2 appearances (participant with/without glasses). We compared the performance of cascade classifiers trained by different sets of the features. The experiment results showed that the proposed approaches effectively improve the performance of face detection in thermal images. In the field experiment, we compared the face detection performance in realistic scenes using thermal and RGB images, and gave discussion based on the results.

"My body was my temple": a narrative revealing body image experiences following treatment of a spinal cord injury.

PubMed

Bailey, K Alysse; Gammage, Kimberley L; van Ingen, Cathy; Ditor, David S

2017-09-01

This narrative explores the lived experience of a young woman, Rebecca, and her transitioned body image after sustaining and being treated for a spinal cord injury. Data were collected from a single semi-structured in-depth interview. Rebecca disclosed her transitioned body image experiences after sustaining a spinal cord injury and being treated by medical staff immediately following her injury. Before her injury, she described a holistic body experience and named this experience her "temple". During intensive care in the hospital, she explained her body was treated as an object. The disconnected treatment of her body led to a loss of the private self, as she described her sacred body being stripped away - her "temple" lost and in ruins. Body image may be an overlooked component of health following a spinal cord injury. This narrative emphasizes the importance of unveiling body image experiences after the treatment of a spinal cord injury to medical professionals. Lessons of the importance of considering the transitioned body experiences after a spinal cord injury may help prevent body-related depression and other subsequent health impacts. Recommendations for best practice are provided. Implications for Rehabilitation    Spinal Cord Injury   • A spinal cord injury may drastically change a person's body image, thereby significantly impacting psychological health   • More effective screening for body image within the medical/rehabilitation context is needed to help practitioners recognize distress   • Practitioners should be prepared to refer clients to distress hotlines they may need once released from treatment.

Acquiring skill at medical image inspection: learning localized in early visual processes

NASA Astrophysics Data System (ADS)

Sowden, Paul T.; Davies, Ian R. L.; Roling, Penny; Watt, Simon J.

1997-04-01

Acquisition of the skill of medical image inspection could be due to changes in visual search processes, 'low-level' sensory learning, and higher level 'conceptual learning.' Here, we report two studies that investigate the extent to which learning in medical image inspection involves low- level learning. Early in the visual processing pathway cells are selective for direction of luminance contrast. We exploit this in the present studies by using transfer across direction of contrast as a 'marker' to indicate the level of processing at which learning occurs. In both studies twelve observers trained for four days at detecting features in x- ray images (experiment one equals discs in the Nijmegen phantom, experiment two equals micro-calcification clusters in digitized mammograms). Half the observers examined negative luminance contrast versions of the images and the remainder examined positive contrast versions. On the fifth day, observers swapped to inspect their respective opposite contrast images. In both experiments leaning occurred across sessions. In experiment one, learning did not transfer across direction of luminance contrast, while in experiment two there was only partial transfer. These findings are consistent with the contention that some of the leaning was localized early in the visual processing pathway. The implications of these results for current medical image inspection training schedules are discussed.

Pipeline for illumination correction of images for high-throughput microscopy.

PubMed

Singh, S; Bray, M-A; Jones, T R; Carpenter, A E

2014-12-01

The presence of systematic noise in images in high-throughput microscopy experiments can significantly impact the accuracy of downstream results. Among the most common sources of systematic noise is non-homogeneous illumination across the image field. This often adds an unacceptable level of noise, obscures true quantitative differences and precludes biological experiments that rely on accurate fluorescence intensity measurements. In this paper, we seek to quantify the improvement in the quality of high-content screen readouts due to software-based illumination correction. We present a straightforward illumination correction pipeline that has been used by our group across many experiments. We test the pipeline on real-world high-throughput image sets and evaluate the performance of the pipeline at two levels: (a) Z'-factor to evaluate the effect of the image correction on a univariate readout, representative of a typical high-content screen, and (b) classification accuracy on phenotypic signatures derived from the images, representative of an experiment involving more complex data mining. We find that applying the proposed post-hoc correction method improves performance in both experiments, even when illumination correction has already been applied using software associated with the instrument. To facilitate the ready application and future development of illumination correction methods, we have made our complete test data sets as well as open-source image analysis pipelines publicly available. This software-based solution has the potential to improve outcomes for a wide-variety of image-based HTS experiments. © 2014 The Authors. Journal of Microscopy published by John Wiley & Sons Ltd on behalf of Royal Microscopical Society.

Animals In Synchrotrons: Overcoming Challenges For High-Resolution, Live, Small-Animal Imaging

NASA Astrophysics Data System (ADS)

Donnelley, Martin; Parsons, David; Morgan, Kaye; Siu, Karen

2010-07-01

Physiological studies in small animals can be complicated, but the complexity is increased dramatically when performing live-animal synchrotron X-ray imaging studies. Our group has extensive experience in high-resolution live-animal imaging at the Japanese SPring-8 synchrotron, primarily examining airways in two-dimensions. These experiments normally image an area of 1.8 mm×1.2 mm at a pixel resolution of 0.45 μm and are performed with live, intact, anaesthetized mice. There are unique challenges in this experimental setting. Importantly, experiments must be performed in an isolated imaging hutch not specifically designed for small-animal imaging. This requires equipment adapted to remotely monitor animals, maintain their anesthesia, and deliver test substances while collecting images. The horizontal synchrotron X-ray beam has a fixed location and orientation that limits experimental flexibility. The extremely high resolution makes locating anatomical regions-of-interest slow and can result in a high radiation dose, and at this level of magnification small animal movements produce motion-artifacts that can render acquired images unusable. Here we describe our experimental techniques and how we have overcome several challenges involved in performing live mouse synchrotron imaging. Experiments have tested different mouse strains, with hairless strains minimizing overlying skin and hair artifacts. Different anesthetics have also be trialed due to the limited choices available at SPring-8. Tracheal-intubation methods have been refined and controlled-ventilation is now possible using a specialized small-animal ventilator. With appropriate animal restraint and respiratory-gating, motion-artifacts have been minimized. The animal orientation (supine vs. head-high) also appears to affect animal physiology, and can alter image quality. Our techniques and image quality at SPring-8 have dramatically improved and in the near future we plan to translate this experience to the Imaging and Medical Beamline at the Australian Synchrotron. Overcoming these challenges has permitted increasingly sophisticated imaging of animals with synchrotron X-rays, and we expect a bright future for these techniques.

Animals In Synchrotrons: Overcoming Challenges For High-Resolution, Live, Small-Animal Imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Donnelley, Martin; Parsons, David; Women's and Children's Health Research Institute, Adelaide, South Australia

Physiological studies in small animals can be complicated, but the complexity is increased dramatically when performing live-animal synchrotron X-ray imaging studies. Our group has extensive experience in high-resolution live-animal imaging at the Japanese SPring-8 synchrotron, primarily examining airways in two-dimensions. These experiments normally image an area of 1.8 mmx1.2 mm at a pixel resolution of 0.45 {mu}m and are performed with live, intact, anaesthetized mice.There are unique challenges in this experimental setting. Importantly, experiments must be performed in an isolated imaging hutch not specifically designed for small-animal imaging. This requires equipment adapted to remotely monitor animals, maintain their anesthesia, andmore » deliver test substances while collecting images. The horizontal synchrotron X-ray beam has a fixed location and orientation that limits experimental flexibility. The extremely high resolution makes locating anatomical regions-of-interest slow and can result in a high radiation dose, and at this level of magnification small animal movements produce motion-artifacts that can render acquired images unusable. Here we describe our experimental techniques and how we have overcome several challenges involved in performing live mouse synchrotron imaging.Experiments have tested different mouse strains, with hairless strains minimizing overlying skin and hair artifacts. Different anesthetics have also be trialed due to the limited choices available at SPring-8. Tracheal-intubation methods have been refined and controlled-ventilation is now possible using a specialized small-animal ventilator. With appropriate animal restraint and respiratory-gating, motion-artifacts have been minimized. The animal orientation (supine vs. head-high) also appears to affect animal physiology, and can alter image quality. Our techniques and image quality at SPring-8 have dramatically improved and in the near future we plan to translate this experience to the Imaging and Medical Beamline at the Australian Synchrotron.Overcoming these challenges has permitted increasingly sophisticated imaging of animals with synchrotron X-rays, and we expect a bright future for these techniques.« less

Quantitative Imaging in Laboratory: Fast Kinetics and Fluorescence Quenching

ERIC Educational Resources Information Center

Cumberbatch, Tanya; Hanley, Quentin S.

2007-01-01

The process of quantitative imaging, which is very commonly used in laboratory, is shown to be very useful for studying the fast kinetics and fluorescence quenching of many experiments. The imaging technique is extremely cheap and hence can be used in many absorption and luminescence experiments.

Image Data Processing System (IDAPS) user manual, S-056 experiment. Volume 1: System description. Volume 2: Batch IDAPS. Volume 3: Interactive IDAPS

NASA Technical Reports Server (NTRS)

1975-01-01

Image data processing system (IDAPS) developed to satisfy the image processing requirements of the Skylab S-056 experiment is described. The S-056 experiment was designed to obtain high-resolution photographs of the sun in the far ultraviolet, or soft X-ray, portion of the electromagnetic spectrum. Thirty-five thousand photographs were obtained by the three flights of the program; and, faced with such a massive volume of imagery, the designers of the experiment decided to develop a computer-based system which would reduce the image processing workload. The purpose of the IDAPS User Manual is to give the IDAPS user the necessary information and instructions to effectively utilize the system.

An active seismic experiment at Tenerife Island (Canary Island, Spain): Imaging an active volcano edifice

NASA Astrophysics Data System (ADS)

Garcia-Yeguas, A.; Ibañez, J. M.; Rietbrock, A.; Tom-Teidevs, G.

2008-12-01

An active seismic experiment to study the internal structure of Teide Volcano was carried out on Tenerife, a volcanic island in Spain's Canary Islands. The main objective of the TOM-TEIDEVS experiment is to obtain a 3-dimensional structural image of Teide Volcano using seismic tomography and seismic reflection/refraction imaging techniques. At present, knowledge of the deeper structure of Teide and Tenerife is very limited, with proposed structural models mainly based on sparse geophysical and geological data. This multinational experiment which involves institutes from Spain, Italy, the United Kingdom, Ireland, and Mexico will generate a unique high resolution structural image of the active volcano edifice and will further our understanding of volcanic processes.

Impact of helical boundary conditions in MHD modeling of RFP and tokamak plasmas

NASA Astrophysics Data System (ADS)

Bonfiglio, D.; Cappello, S.; Escande, D. F.; Piovesan, P.; Veranda, M.; Chacón, L.

2012-10-01

Helical boundary conditions imposed by the active control system of the RFX-mod device provide a handle to govern the plasma dynamics in both RFP and Ohmic tokamak discharges [1]. By applying an edge radial magnetic field with proper helicity, it is possible to increase the persistence of the spontaneous helical RFP states at high current,and to stimulate them also at low current or high density. Helical BCs even allow to access helical states with different helicity than the spontaneous one [2]. In Ohmic tokamak operation at q(a)<2, the presence of the 2/1 RWM reduces the sawtoothing activity of the 1/1 internal kink, which takes a stationary snake-like character instead. Many of these features are qualitatively reproduced in 3D nonlinear MHD modeling. We study the impact of helical BCs on the MHD dynamics in both RFP and tokamak with two successfully benchmarked numerical tools, SpeCyl and PIXIE3D [3]. We recover the bifurcation from a sawtooth to a snake solution when imposing a 2/1 BC in the tokamak case and we interpret this as a toroidal/nonlinear coupling effect. We show that the bifurcation is more easily stimulated with a 1/1 BC.[4pt] [1] P. Piovesan, invited talk this meeting[0pt] [2] M. Veranda et al EPS-ICPP Conference (2012) P4.004[0pt] [3] D. Bonfiglio et al Phys. Plasmas (2010)

An approach to optimize sample preparation for MALDI imaging MS of FFPE sections using fractional factorial design of experiments.

PubMed

Oetjen, Janina; Lachmund, Delf; Palmer, Andrew; Alexandrov, Theodore; Becker, Michael; Boskamp, Tobias; Maass, Peter

2016-09-01

A standardized workflow for matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI imaging MS) is a prerequisite for the routine use of this promising technology in clinical applications. We present an approach to develop standard operating procedures for MALDI imaging MS sample preparation of formalin-fixed and paraffin-embedded (FFPE) tissue sections based on a novel quantitative measure of dataset quality. To cover many parts of the complex workflow and simultaneously test several parameters, experiments were planned according to a fractional factorial design of experiments (DoE). The effect of ten different experiment parameters was investigated in two distinct DoE sets, each consisting of eight experiments. FFPE rat brain sections were used as standard material because of low biological variance. The mean peak intensity and a recently proposed spatial complexity measure were calculated for a list of 26 predefined peptides obtained by in silico digestion of five different proteins and served as quality criteria. A five-way analysis of variance (ANOVA) was applied on the final scores to retrieve a ranking of experiment parameters with increasing impact on data variance. Graphical abstract MALDI imaging experiments were planned according to fractional factorial design of experiments for the parameters under study. Selected peptide images were evaluated by the chosen quality metric (structure and intensity for a given peak list), and the calculated values were used as an input for the ANOVA. The parameters with the highest impact on the quality were deduced and SOPs recommended.

Bodily Deviations and Body Image in Adolescence

ERIC Educational Resources Information Center

Vilhjalmsson, Runar; Kristjansdottir, Gudrun; Ward, Dianne S.

2012-01-01

Adolescents with unusually sized or shaped bodies may experience ridicule, rejection, or exclusion based on their negatively valued bodily characteristics. Such experiences can have negative consequences for a person's image and evaluation of self. This study focuses on the relationship between bodily deviations and body image and is based on a…

Effect of Reading Ability and Internet Experience on Keyword-Based Image Search

ERIC Educational Resources Information Center

Lei, Pei-Lan; Lin, Sunny S. J.; Sun, Chuen-Tsai

2013-01-01

Image searches are now crucial for obtaining information, constructing knowledge, and building successful educational outcomes. We investigated how reading ability and Internet experience influence keyword-based image search behaviors and performance. We categorized 58 junior-high-school students into four groups of high/low reading ability and…

Changing job seekers' image perceptions during recruitment visits: the moderating role of belief confidence.

PubMed

Slaughter, Jerel E; Cable, Daniel M; Turban, Daniel B

2014-11-01

The purpose of this study was to understand how an important construct in social psychology-confidence in one's beliefs-could both (a) influence the effectiveness of organizations' recruiting processes and (b) be changed during recruitment. Using a sample of recruits to a branch of the United States military, the authors studied belief confidence before and after recruits' formal visits to the organization's recruiting stations. Personal sources of information had a stronger influence on recruits' belief confidence than impersonal sources. Moreover, recruits' confidence in their initial beliefs affected how perceptions of the recruiter changed their employer images. Among participants with low-initial confidence, the relation between recruitment experiences and employer images was positive and linear across the whole range of recruitment experiences. Among recruits with high-initial confidence, however, the recruitment experience-image relationship was curvilinear, such that recruitment experiences were related to images only at more positive recruitment experiences. The relationship between recruitment experiences and changes in belief confidence was also curvilinear, such that only more positive recruitment experiences led to changes in confidence. These results indicate not only that belief confidence influences the effectiveness of recruiting efforts but also that recruiting efforts can influence belief confidence. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

The effect of dental artifacts, contrast media, and experience on interobserver contouring variations in head and neck anatomy.

PubMed

O'Daniel, Jennifer C; Rosenthal, David I; Garden, Adam S; Barker, Jerry L; Ahamad, Anesa; Ang, K Kian; Asper, Joshua A; Blanco, Angel I; de Crevoisier, Renaud; Holsinger, F Christopher; Patel, Chirag B; Schwartz, David L; Wang, He; Dong, Lei

2007-04-01

To investigate interobserver variability in the delineation of head-and-neck (H&N) anatomic structures on CT images, including the effects of image artifacts and observer experience. Nine observers (7 radiation oncologists, 1 surgeon, and 1 physician assistant) with varying levels of H&N delineation experience independently contoured H&N gross tumor volumes and critical structures on radiation therapy treatment planning CT images alongside reference diagnostic CT images for 4 patients with oropharynx cancer. Image artifacts from dental fillings partially obstructed 3 images. Differences in the structure volumes, center-of-volume positions, and boundary positions (1 SD) were measured. In-house software created three-dimensional overlap distributions, including all observers. The effects of dental artifacts and observer experience on contouring precision were investigated, and the need for contrast media was assessed. In the absence of artifacts, all 9 participants achieved reasonable precision (1 SD < or =3 mm all boundaries). The structures obscured by dental image artifacts had larger variations when measured by the 3 metrics (1 SD = 8 mm cranial/caudal boundary). Experience improved the interobserver consistency of contouring for structures obscured by artifacts (1 SD = 2 mm cranial/caudal boundary). Interobserver contouring variability for anatomic H&N structures, specifically oropharyngeal gross tumor volumes and parotid glands, was acceptable in the absence of artifacts. Dental artifacts increased the contouring variability, but experienced participants achieved reasonable precision even with artifacts present. With a staging contrast CT image as a reference, delineation on a noncontrast treatment planning CT image can achieve acceptable precision.

Compact Microscope Imaging System Developed

NASA Technical Reports Server (NTRS)

McDowell, Mark

2001-01-01

The Compact Microscope Imaging System (CMIS) is a diagnostic tool with intelligent controls for use in space, industrial, medical, and security applications. The CMIS can be used in situ with a minimum amount of user intervention. This system, which was developed at the NASA Glenn Research Center, can scan, find areas of interest, focus, and acquire images automatically. Large numbers of multiple cell experiments require microscopy for in situ observations; this is only feasible with compact microscope systems. CMIS is a miniature machine vision system that combines intelligent image processing with remote control capabilities. The software also has a user-friendly interface that can be used independently of the hardware for post-experiment analysis. CMIS has potential commercial uses in the automated online inspection of precision parts, medical imaging, security industry (examination of currency in automated teller machines and fingerprint identification in secure entry locks), environmental industry (automated examination of soil/water samples), biomedical field (automated blood/cell analysis), and microscopy community. CMIS will improve research in several ways: It will expand the capabilities of MSD experiments utilizing microscope technology. It may be used in lunar and Martian experiments (Rover Robot). Because of its reduced size, it will enable experiments that were not feasible previously. It may be incorporated into existing shuttle orbiter and space station experiments, including glove-box-sized experiments as well as ground-based experiments.

Seeing mathematics: perceptual experience and brain activity in acquired synesthesia.

PubMed

Brogaard, Berit; Vanni, Simo; Silvanto, Juha

2013-01-01

We studied the patient JP who has exceptional abilities to draw complex geometrical images by hand and a form of acquired synesthesia for mathematical formulas and objects, which he perceives as geometrical figures. JP sees all smooth curvatures as discrete lines, similarly regardless of scale. We carried out two preliminary investigations to establish the perceptual nature of synesthetic experience and to investigate the neural basis of this phenomenon. In a functional magnetic resonance imaging (fMRI) study, image-inducing formulas produced larger fMRI responses than non-image inducing formulas in the left temporal, parietal and frontal lobes. Thus our main finding is that the activation associated with his experience of complex geometrical images emerging from mathematical formulas is restricted to the left hemisphere.

NMR-based diffusion pore imaging.

PubMed

Laun, Frederik Bernd; Kuder, Tristan Anselm; Wetscherek, Andreas; Stieltjes, Bram; Semmler, Wolfhard

2012-08-01

Nuclear magnetic resonance (NMR) diffusion experiments offer a unique opportunity to study boundaries restricting the diffusion process. In a recent Letter [Phys. Rev. Lett. 107, 048102 (2011)], we introduced the idea and concept that such diffusion experiments can be interpreted as NMR imaging experiments. Consequently, images of closed pores, in which the spins diffuse, can be acquired. In the work presented here, an in-depth description of the diffusion pore imaging technique is provided. Image artifacts due to gradient profiles of finite duration, field inhomogeneities, and surface relaxation are considered. Gradients of finite duration lead to image blurring and edge enhancement artifacts. Field inhomogeneities have benign effects on diffusion pore images, and surface relaxation can lead to a shrinkage and shift of the pore image. The relation between boundary structure and the imaginary part of the diffusion weighted signal is analyzed, and it is shown that information on pore coherence can be obtained without the need to measure the phase of the diffusion weighted signal. Moreover, it is shown that quite arbitrary gradient profiles can be used for diffusion pore imaging. The matrices required for numerical calculations are stated and provided as supplemental material.

Genome image programs: visualization and interpretation of Escherichia coli microarray experiments.

PubMed

Zimmer, Daniel P; Paliy, Oleg; Thomas, Brian; Gyaneshwar, Prasad; Kustu, Sydney

2004-08-01

We have developed programs to facilitate analysis of microarray data in Escherichia coli. They fall into two categories: manipulation of microarray images and identification of known biological relationships among lists of genes. A program in the first category arranges spots from glass-slide DNA microarrays according to their position in the E. coli genome and displays them compactly in genome order. The resulting genome image is presented in a web browser with an image map that allows the user to identify genes in the reordered image. Another program in the first category aligns genome images from two or more experiments. These images assist in visualizing regions of the genome with common transcriptional control. Such regions include multigene operons and clusters of operons, which are easily identified as strings of adjacent, similarly colored spots. The images are also useful for assessing the overall quality of experiments. The second category of programs includes a database and a number of tools for displaying biological information about many E. coli genes simultaneously rather than one gene at a time, which facilitates identifying relationships among them. These programs have accelerated and enhanced our interpretation of results from E. coli DNA microarray experiments. Examples are given. Copyright 2004 Genetics Society of America

The impact of early shame memories in Binge Eating Disorder: The mediator effect of current body image shame and cognitive fusion.

PubMed

Duarte, Cristiana; Pinto-Gouveia, José

2017-12-01

This study examined the phenomenology of shame experiences from childhood and adolescence in a sample of women with Binge Eating Disorder. Moreover, a path analysis was investigated testing whether the association between shame-related memories which are traumatic and central to identity, and binge eating symptoms' severity, is mediated by current external shame, body image shame and body image cognitive fusion. Participants in this study were 114 patients, who were assessed through the Eating Disorder Examination and the Shame Experiences Interview, and through self-report measures of external shame, body image shame, body image cognitive fusion and binge eating symptoms. Shame experiences where physical appearance was negatively commented or criticized by others were the most frequently recalled. A path analysis showed a good fit between the hypothesised mediational model and the data. The traumatic and centrality qualities of shame-related memories predicted current external shame, especially body image shame. Current shame feelings were associated with body image cognitive fusion, which, in turn, predicted levels of binge eating symptomatology. Findings support the relevance of addressing early shame-related memories and negative affective and self-evaluative experiences, namely related to body image, in the understanding and management of binge eating. Copyright © 2017 Elsevier B.V. All rights reserved.

Students' ideas about prismatic images: teaching experiments for an image-based approach

NASA Astrophysics Data System (ADS)

Grusche, Sascha

2017-05-01

Prismatic refraction is a classic topic in science education. To investigate how undergraduate students think about prismatic dispersion, and to see how they change their thinking when observing dispersed images, five teaching experiments were done and analysed according to the Model of Educational Reconstruction. For projection through a prism, the students used a 'split image projection' conceptualisation. For the view through a prism, this conceptualisation was not fruitful. Based on the observed images, six of seven students changed to a 'diverted image projection' conceptualisation. From a comparison between students' and scientists' ideas, teaching implications are derived for an image-based approach.

Developing students’ ideas about lens imaging: teaching experiments with an image-based approach

NASA Astrophysics Data System (ADS)

Grusche, Sascha

2017-07-01

Lens imaging is a classic topic in physics education. To guide students from their holistic viewpoint to the scientists’ analytic viewpoint, an image-based approach to lens imaging has recently been proposed. To study the effect of the image-based approach on undergraduate students’ ideas, teaching experiments are performed and evaluated using qualitative content analysis. Some of the students’ ideas have not been reported before, namely those related to blurry lens images, and those developed by the proposed teaching approach. To describe learning pathways systematically, a conception-versus-time coordinate system is introduced, specifying how teaching actions help students advance toward a scientific understanding.

Performance evaluation of infrared imaging system in field test

NASA Astrophysics Data System (ADS)

Wang, Chensheng; Guo, Xiaodong; Ren, Tingting; Zhang, Zhi-jie

2014-11-01

Infrared imaging system has been applied widely in both military and civilian fields. Since the infrared imager has various types and different parameters, for system manufacturers and customers, there is great demand for evaluating the performance of IR imaging systems with a standard tool or platform. Since the first generation IR imager was developed, the standard method to assess the performance has been the MRTD or related improved methods which are not perfect adaptable for current linear scanning imager or 2D staring imager based on FPA detector. For this problem, this paper describes an evaluation method based on the triangular orientation discrimination metric which is considered as the effective and emerging method to evaluate the synthesis performance of EO system. To realize the evaluation in field test, an experiment instrument is developed. And considering the importance of operational environment, the field test is carried in practical atmospheric environment. The test imagers include panoramic imaging system and staring imaging systems with different optics and detectors parameters (both cooled and uncooled). After showing the instrument and experiment setup, the experiment results are shown. The target range performance is analyzed and discussed. In data analysis part, the article gives the range prediction values obtained from TOD method, MRTD method and practical experiment, and shows the analysis and results discussion. The experimental results prove the effectiveness of this evaluation tool, and it can be taken as a platform to give the uniform performance prediction reference.

Enhancements to the Image Analysis Tool for Core Punch Experiments and Simulations (vs. 2014)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hogden, John Edward; Unal, Cetin

A previous paper (Hogden & Unal, 2012, Image Analysis Tool for Core Punch Experiments and Simulations) described an image processing computer program developed at Los Alamos National Laboratory. This program has proven useful so developement has been continued. In this paper we describe enhacements to the program as of 2014.

Sequential Processes in Image Generation: An Objective Measure. Technical Report #6.

ERIC Educational Resources Information Center

Kosslyn, Stephen M.; And Others

This paper investigates the processes by which visual mental images--the precept-like short-term memory representations--are created from information stored in long-term memory. It also presents a new method for studying image generation. Three experiments were conducted using college students as subjects. In the first experiment, a Podgorny and…

Image Schemas in Verb-Particle Constructions: Evidence from a Behavioral Experiment

ERIC Educational Resources Information Center

Yang, Tangfeng

2016-01-01

Cognitive linguists claim that verb-particle constructions are compositional and analyzable, and that the particles contribute to the overall meaning in the form of image schemas. This article examined this claim with a behavioral experiment, in which participants were asked to judge the sensibility of short sentences primed by image-schematic…

Students' Ideas about Prismatic Images: Teaching Experiments for an Image-Based Approach

ERIC Educational Resources Information Center

Grusche, Sascha

2017-01-01

Prismatic refraction is a classic topic in science education. To investigate how undergraduate students think about prismatic dispersion, and to see how they change their thinking when observing dispersed images, five teaching experiments were done and analysed according to the Model of Educational Reconstruction. For projection through a prism,…

The meaning of body experience evaluation in oncology.

PubMed

Slatman, Jenny

2011-12-01

Evaluation of quality of life, psychic and bodily well-being is becoming increasingly important in oncology aftercare. This type of assessment is mainly carried out by medical psychologists. In this paper I will seek to show that body experience valuation has, besides its psychological usefulness, a normative and practical dimension. Body experience evaluation aims at establishing the way a person experiences and appreciates his or her physical appearance, intactness and competence. This valuation constitutes one's 'body image'. While, first, interpreting the meaning of body image and, second, indicating the limitations of current psychological body image assessment, I argue that the normative aspect of body image is related to the experience of bodily wholeness or bodily integrity. Since this experience is contextualized by a person's life story, evaluation should also focus on narrative aspects. I finally suggest that the interpretation of body experience is not only valuable to assess a person's quality of life after treatment, but that it can also be useful in counseling prior to interventions, since it can support patients in making decisions about interventions that will change their bodies. To apply this type of evaluation to oncology practice, a rich and tailored vocabulary of body experiences has to be developed.

Development of a Machine-Vision System for Recording of Force Calibration Data

NASA Astrophysics Data System (ADS)

Heamawatanachai, Sumet; Chaemthet, Kittipong; Changpan, Tawat

This paper presents the development of a new system for recording of force calibration data using machine vision technology. Real time camera and computer system were used to capture images of the reading from the instruments during calibration. Then, the measurement images were transformed and translated to numerical data using optical character recognition (OCR) technique. These numerical data along with raw images were automatically saved to memories as the calibration database files. With this new system, the human error of recording would be eliminated. The verification experiments were done by using this system for recording the measurement results from an amplifier (DMP 40) with load cell (HBM-Z30-10kN). The NIMT's 100-kN deadweight force standard machine (DWM-100kN) was used to generate test forces. The experiments setup were done in 3 categories; 1) dynamics condition (record during load changing), 2) statics condition (record during fix load), and 3) full calibration experiments in accordance with ISO 376:2011. The captured images from dynamics condition experiment gave >94% without overlapping of number. The results from statics condition experiment were >98% images without overlapping. All measurement images without overlapping were translated to number by the developed program with 100% accuracy. The full calibration experiments also gave 100% accurate results. Moreover, in case of incorrect translation of any result, it is also possible to trace back to the raw calibration image to check and correct it. Therefore, this machine-vision-based system and program should be appropriate for recording of force calibration data.

Visual properties and memorising scenes: Effects of image-space sparseness and uniformity.

PubMed

Lukavský, Jiří; Děchtěrenko, Filip

2017-10-01

Previous studies have demonstrated that humans have a remarkable capacity to memorise a large number of scenes. The research on memorability has shown that memory performance can be predicted by the content of an image. We explored how remembering an image is affected by the image properties within the context of the reference set, including the extent to which it is different from its neighbours (image-space sparseness) and if it belongs to the same category as its neighbours (uniformity). We used a reference set of 2,048 scenes (64 categories), evaluated pairwise scene similarity using deep features from a pretrained convolutional neural network (CNN), and calculated the image-space sparseness and uniformity for each image. We ran three memory experiments, varying the memory workload with experiment length and colour/greyscale presentation. We measured the sensitivity and criterion value changes as a function of image-space sparseness and uniformity. Across all three experiments, we found separate effects of 1) sparseness on memory sensitivity, and 2) uniformity on the recognition criterion. People better remembered (and correctly rejected) images that were more separated from others. People tended to make more false alarms and fewer miss errors in images from categorically uniform portions of the image-space. We propose that both image-space properties affect human decisions when recognising images. Additionally, we found that colour presentation did not yield better memory performance over grayscale images.

Biomedical imaging and sensing using flatbed scanners.

PubMed

Göröcs, Zoltán; Ozcan, Aydogan

2014-09-07

In this Review, we provide an overview of flatbed scanner based biomedical imaging and sensing techniques. The extremely large imaging field-of-view (e.g., ~600-700 cm(2)) of these devices coupled with their cost-effectiveness provide unique opportunities for digital imaging of samples that are too large for regular optical microscopes, and for collection of large amounts of statistical data in various automated imaging or sensing tasks. Here we give a short introduction to the basic features of flatbed scanners also highlighting the key parameters for designing scientific experiments using these devices, followed by a discussion of some of the significant examples, where scanner-based systems were constructed to conduct various biomedical imaging and/or sensing experiments. Along with mobile phones and other emerging consumer electronics devices, flatbed scanners and their use in advanced imaging and sensing experiments might help us transform current practices of medicine, engineering and sciences through democratization of measurement science and empowerment of citizen scientists, science educators and researchers in resource limited settings.

Biomedical Imaging and Sensing using Flatbed Scanners

PubMed Central

Göröcs, Zoltán; Ozcan, Aydogan

2014-01-01

In this Review, we provide an overview of flatbed scanner based biomedical imaging and sensing techniques. The extremely large imaging field-of-view (e.g., ~600–700 cm2) of these devices coupled with their cost-effectiveness provide unique opportunities for digital imaging of samples that are too large for regular optical microscopes, and for collection of large amounts of statistical data in various automated imaging or sensing tasks. Here we give a short introduction to the basic features of flatbed scanners also highlighting the key parameters for designing scientific experiments using these devices, followed by a discussion of some of the significant examples, where scanner-based systems were constructed to conduct various biomedical imaging and/or sensing experiments. Along with mobile phones and other emerging consumer electronics devices, flatbed scanners and their use in advanced imaging and sensing experiments might help us transform current practices of medicine, engineering and sciences through democratization of measurement science and empowerment of citizen scientists, science educators and researchers in resource limited settings. PMID:24965011

A learning tool for optical and microwave satellite image processing and analysis

NASA Astrophysics Data System (ADS)

Dashondhi, Gaurav K.; Mohanty, Jyotirmoy; Eeti, Laxmi N.; Bhattacharya, Avik; De, Shaunak; Buddhiraju, Krishna M.

2016-04-01

This paper presents a self-learning tool, which contains a number of virtual experiments for processing and analysis of Optical/Infrared and Synthetic Aperture Radar (SAR) images. The tool is named Virtual Satellite Image Processing and Analysis Lab (v-SIPLAB) Experiments that are included in Learning Tool are related to: Optical/Infrared - Image and Edge enhancement, smoothing, PCT, vegetation indices, Mathematical Morphology, Accuracy Assessment, Supervised/Unsupervised classification etc.; Basic SAR - Parameter extraction and range spectrum estimation, Range compression, Doppler centroid estimation, Azimuth reference function generation and compression, Multilooking, image enhancement, texture analysis, edge and detection. etc.; SAR Interferometry - BaseLine Calculation, Extraction of single look SAR images, Registration, Resampling, and Interferogram generation; SAR Polarimetry - Conversion of AirSAR or Radarsat data to S2/C3/T3 matrix, Speckle Filtering, Power/Intensity image generation, Decomposition of S2/C3/T3, Classification of S2/C3/T3 using Wishart Classifier [3]. A professional quality polarimetric SAR software can be found at [8], a part of whose functionality can be found in our system. The learning tool also contains other modules, besides executable software experiments, such as aim, theory, procedure, interpretation, quizzes, link to additional reading material and user feedback. Students can have understanding of Optical and SAR remotely sensed images through discussion of basic principles and supported by structured procedure for running and interpreting the experiments. Quizzes for self-assessment and a provision for online feedback are also being provided to make this Learning tool self-contained. One can download results after performing experiments.

Telescope performance and image simulations of the balloon-borne coded-mask protoMIRAX experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Penacchioni, A. V., E-mail: ana.penacchioni@inpe.br; Braga, J., E-mail: joao.braga@inpe.br; Castro, M. A., E-mail: manuel.castro@inpe.br

2015-12-17

In this work we present the results of imaging simulations performed with the help of the GEANT4 package for the protoMIRAX hard X-ray balloon experiment. The instrumental background was simulated taking into account the various radiation components and their angular dependence, as well as a detailed mass model of the experiment. We modelled the meridian transits of the Crab Nebula and the Galactic Centre (CG) region during balloon flights in Brazil (∼ −23° of latitude and an altitude of ∼40 km) and introduced the correspondent spectra as inputs to the imaging simulations. We present images of the Crab and ofmore » three sources in the GC: 1E 1740.7-2942, GRS 1758-258 and GX 1+4. The results show that the protoMIRAX experiment is capable of making spectral and timing observations of bright hard X-ray sources as well as important imaging demonstrations that will contribute to the design of the MIRAX satellite mission.« less

Decision-Based Design of a Low Vision Aid

DTIC Science & Technology

1999-12-05

No loss ML 32 Aniridia Cloudy No Loss TT 35 Glaucoma Cloudy No Loss MM 23 Stargardt Disease Clear Loss AP 40 Congenital Retinal Malformations...brief clinical background evaluation, and a post-experiment questionnaire. The study was further expanded in scope to gather data for the VRD...Introduction and clinical evaluation 3) Experiments with red, blue and green images 4) Experiments with white images 5) Post experiment

Pupillary Responses to Static Images of Men and Women: A Possible Measure of Sexual Interest?

PubMed

Snowden, Robert J; McKinnon, Aimee; Fitoussi, Julie; Gray, Nicola S

2017-12-08

The pupil dilates to images that are arousing. In Experiment 1, we examined if the pupil's response to brief presentations (2,000 ms) of static images could be used to identify individuals' sexual orientation. Participants were grouped according to their self-reported gender and sexual orientation (male heterosexual, N = 20; male bisexual, N = 13; male homosexual, N = 19; female heterosexual, N = 28; female bisexual, N = 21; female homosexual, N = 17). Pupil size was monitored to images of men in seminude poses, women in seminude poses, or neutral images. Every group showed the same pattern of responses, with the greatest dilation to male images, then female images, and least dilation to the neutral images. Experiment 2 used more tightly controlled stimuli and tested at two different image durations (150 and 3,000 ms). Both heterosexual men (N = 18) and women (N = 20) showed greater pupil dilation to images of nude men than to nude women. However, in Experiment 3, where we reduced the erotic content by using images of clothed models, both heterosexual men and women showed greater pupil dilation to images of women. The results showed that while the pupil does dilate strongly to sexual imagery, its response to these brief static images does not correspond to a person's sexual orientation in a simple manner.

Simultaneous neutron and x-ray imaging of inertial confinement fusion experiments along a single line of sight at Omega.

PubMed

Danly, C R; Day, T H; Fittinghoff, D N; Herrmann, H; Izumi, N; Kim, Y H; Martinez, J I; Merrill, F E; Schmidt, D W; Simpson, R A; Volegov, P L; Wilde, C H

2015-04-01

Neutron and x-ray imaging provide critical information about the geometry and hydrodynamics of inertial confinement fusion implosions. However, existing diagnostics at Omega and the National Ignition Facility (NIF) cannot produce images in both neutrons and x-rays along the same line of sight. This leads to difficulty comparing these images, which capture different parts of the plasma geometry, for the asymmetric implosions seen in present experiments. Further, even when opposing port neutron and x-ray images are available, they use different detectors and cannot provide positive information about the relative positions of the neutron and x-ray sources. A technique has been demonstrated on implosions at Omega that can capture x-ray images along the same line of sight as the neutron images. The technique is described, and data from a set of experiments are presented, along with a discussion of techniques for coregistration of the various images. It is concluded that the technique is viable and could provide valuable information if implemented on NIF in the near future.

Simultaneous neutron and x-ray imaging of inertial confinement fusion experiments along a single line of sight at Omega

DOE Office of Scientific and Technical Information (OSTI.GOV)

Danly, C. R.; Day, T. H.; Fittinghoff, D. N.

Neutron and x-ray imaging provide critical information about the geometry and hydrodynamics of inertial confinement fusion implosions. However, existing diagnostics at Omega and the National Ignition Facility (NIF) cannot produce images in both neutrons and x-rays along the same line of sight. This leads to difficulty comparing these images, which capture different parts of the plasma geometry, for the asymmetric implosions seen in present experiments. Further, even when opposing port neutron and x-ray images are available, they use different detectors and cannot provide positive information about the relative positions of the neutron and x-ray sources. A technique has been demonstratedmore » on implosions at Omega that can capture x-ray images along the same line of sight as the neutron images. Thus, the technique is described, and data from a set of experiments are presented, along with a discussion of techniques for coregistration of the various images. It is concluded that the technique is viable and could provide valuable information if implemented on NIF in the near future.« less

Simultaneous neutron and x-ray imaging of inertial confinement fusion experiments along a single line of sight at Omega

DOE Office of Scientific and Technical Information (OSTI.GOV)

Danly, C. R.; Day, T. H.; Herrmann, H.

Neutron and x-ray imaging provide critical information about the geometry and hydrodynamics of inertial confinement fusion implosions. However, existing diagnostics at Omega and the National Ignition Facility (NIF) cannot produce images in both neutrons and x-rays along the same line of sight. This leads to difficulty comparing these images, which capture different parts of the plasma geometry, for the asymmetric implosions seen in present experiments. Further, even when opposing port neutron and x-ray images are available, they use different detectors and cannot provide positive information about the relative positions of the neutron and x-ray sources. A technique has been demonstratedmore » on implosions at Omega that can capture x-ray images along the same line of sight as the neutron images. The technique is described, and data from a set of experiments are presented, along with a discussion of techniques for coregistration of the various images. It is concluded that the technique is viable and could provide valuable information if implemented on NIF in the near future.« less

Simultaneous neutron and x-ray imaging of inertial confinement fusion experiments along a single line of sight at Omega

DOE PAGES

Danly, C. R.; Day, T. H.; Fittinghoff, D. N.; ...

2015-04-16

Neutron and x-ray imaging provide critical information about the geometry and hydrodynamics of inertial confinement fusion implosions. However, existing diagnostics at Omega and the National Ignition Facility (NIF) cannot produce images in both neutrons and x-rays along the same line of sight. This leads to difficulty comparing these images, which capture different parts of the plasma geometry, for the asymmetric implosions seen in present experiments. Further, even when opposing port neutron and x-ray images are available, they use different detectors and cannot provide positive information about the relative positions of the neutron and x-ray sources. A technique has been demonstratedmore » on implosions at Omega that can capture x-ray images along the same line of sight as the neutron images. Thus, the technique is described, and data from a set of experiments are presented, along with a discussion of techniques for coregistration of the various images. It is concluded that the technique is viable and could provide valuable information if implemented on NIF in the near future.« less

From Horse-Drawn Wagon to Hot Rod: The University of California's Digital Image Service Experience

ERIC Educational Resources Information Center

Burns, Maureen A.

2006-01-01

This article proposes that a viable approach archivists might consider to meet increasing demands for access to digital images with functional presentation tools is to develop a reciprocal partnership with a digital library. The University of California's experience with the federation of licensed and UC-owned digital image collections is…

Reflections From a Fresnel Lens

ERIC Educational Resources Information Center

Keeports, David

2005-01-01

Reflection of light by a convex Fresnel lens gives rise to two distinct images. A highly convex inverted real reflective image forms on the object side of the lens, while an upright virtual reflective image forms on the opposite side of the lens. I describe here a set of laser experiments performed upon a Fresnel lens. These experiments provide…

Investigation of the Helmholtz-Kohlrausch effect using wide-gamut display

NASA Astrophysics Data System (ADS)

Oh, Semin; Kwak, Youngshin

2015-01-01

The aim of this study is to investigate whether the Helmholtz-Kohlrausch effect exists among the images having various luminance and chroma levels. Firstly, five images were selected. Then each image was adjusted to have 4 different average CIECAM02 C and 5 different average CIECAM02 J. In total 20 test images were generated per each image for the psychophysical experiment. The psychophysical experiment was done in a dark room using a LCD display. To evaluate the overall perceived brightness of images a magnitude estimation method was used. Fifteen participants evaluated the brightness of each image comparing with the reference image. As a result, participants tended to evaluate the brightness higher as the average CIECAM02 J and also CIECAM02 C of the image increases proving the Helmholtz- Kohlrausch effect in images.

VQone MATLAB toolbox: A graphical experiment builder for image and video quality evaluations: VQone MATLAB toolbox.

PubMed

Nuutinen, Mikko; Virtanen, Toni; Rummukainen, Olli; Häkkinen, Jukka

2016-03-01

This article presents VQone, a graphical experiment builder, written as a MATLAB toolbox, developed for image and video quality ratings. VQone contains the main elements needed for the subjective image and video quality rating process. This includes building and conducting experiments and data analysis. All functions can be controlled through graphical user interfaces. The experiment builder includes many standardized image and video quality rating methods. Moreover, it enables the creation of new methods or modified versions from standard methods. VQone is distributed free of charge under the terms of the GNU general public license and allows code modifications to be made so that the program's functions can be adjusted according to a user's requirements. VQone is available for download from the project page (http://www.helsinki.fi/psychology/groups/visualcognition/).

Viewing Artworks: Contributions of Cognitive Control and Perceptual Facilitation to Aesthetic Experience

ERIC Educational Resources Information Center

Cupchik, Gerald C.; Vartanian, Oshin; Crawley, Adrian; Mikulis, David J.

2009-01-01

When we view visual images in everyday life, our perception is oriented toward object identification. In contrast, when viewing visual images "as artworks", we also tend to experience subjective reactions to their stylistic and structural properties. This experiment sought to determine how cognitive control and perceptual facilitation contribute…

Automated camera-phone experience with the frequency of imaging necessary to capture diet.

PubMed

Arab, Lenore; Winter, Ashley

2010-08-01

Camera-enabled cell phones provide an opportunity to strengthen dietary recall through automated imaging of foods eaten during a specified period. To explore the frequency of imaging needed to capture all foods eaten, we examined the number of images of individual foods consumed in a pilot study of automated imaging using camera phones set to an image-capture frequency of one snapshot every 10 seconds. Food images were tallied from 10 young adult subjects who wore the phone continuously during the work day and consented to share their images. Based on the number of images received for each eating experience, the pilot data suggest that automated capturing of images at a frequency of once every 10 seconds is adequate for recording foods consumed during regular meals, whereas a greater frequency of imaging is necessary to capture snacks and beverages eaten quickly. 2010 American Dietetic Association. Published by Elsevier Inc. All rights reserved.

[Application possibilities and initial experience with digital volume tomography in hand and wrist imaging].

PubMed

Goerke, Sebastian M; Neubauer, J; Zajonc, H; Thiele, J R; Kotter, E; Langer, M; Stark, G B; Lampert, F M

2015-02-01

During the last decade, DVT (digital volume tomography) imaging has become a widely used standard technique in head and neck imaging. Lower radiation exposure compared to conventional computed tomography (MDCT) has been described. Recently, DVT has been developed as an extremity scanner and as such represents a new imaging technique for hand surgery. We here describe the first 24 months experience with this new imaging modality in hand and wrist imaging by presenting representative cases and by describing the technical background. Furthermore, the method's advantages and disadvantages are discussed with reference to the given literature. © Georg Thieme Verlag KG Stuttgart · New York.

Simulation and measurement of total ionizing dose radiation induced image lag increase in pinned photodiode CMOS image sensors

NASA Astrophysics Data System (ADS)

Liu, Jing; Chen, Wei; Wang, Zujun; Xue, Yuanyuan; Yao, Zhibin; He, Baoping; Ma, Wuying; Jin, Junshan; Sheng, Jiangkun; Dong, Guantao

2017-06-01

This paper presents an investigation of total ionizing dose (TID) induced image lag sources in pinned photodiodes (PPD) CMOS image sensors based on radiation experiments and TCAD simulation. The radiation experiments have been carried out at the Cobalt -60 gamma-ray source. The experimental results show the image lag degradation is more and more serious with increasing TID. Combining with the TCAD simulation results, we can confirm that the junction of PPD and transfer gate (TG) is an important region forming image lag during irradiation. These simulations demonstrate that TID can generate a potential pocket leading to incomplete transfer.

Psychophysical experiments on the PicHunter image retrieval system

NASA Astrophysics Data System (ADS)

Papathomas, Thomas V.; Cox, Ingemar J.; Yianilos, Peter N.; Miller, Matt L.; Minka, Thomas P.; Conway, Tiffany E.; Ghosn, Joumana

2001-01-01

Psychophysical experiments were conducted on PicHunter, a content-based image retrieval (CBIR) experimental prototype with the following properties: (1) Based on a model of how users respond, it uses Bayes's rule to predict what target users want, given their actions. (2) It possesses an extremely simple user interface. (3) It employs an entropy- based scheme to improve convergence. (4) It introduces a paradigm for assessing the performance of CBIR systems. Experiments 1-3 studied human judgment of image similarity to obtain data for the model. Experiment 4 studied the importance of using: (a) semantic information, (b) memory of earlier input, and (c) relative and absolute judgments of similarity. Experiment 5 tested an approach that we propose for comparing performances of CBIR systems objectively. Finally, experiment 6 evaluated the most informative display-updating scheme that is based on entropy minimization, and confirmed earlier simulation results. These experiments represent one of the first attempts to quantify CBIR performance based on psychophysical studies, and they provide valuable data for improving CBIR algorithms. Even though they were designed with PicHunter in mind, their results can be applied to any CBIR system and, more generally, to any system that involves judgment of image similarity by humans.

Positive media portrayals of obese persons: impact on attitudes and image preferences.

PubMed

Pearl, Rebecca L; Puhl, Rebecca M; Brownell, Kelly D

2012-11-01

The purpose of this research was to assess the impact of nonstereotypical, positive media portrayals of obese persons on biased attitudes, as well as propose a change in media practices that could reduce public weight bias and consequent negative health outcomes for those who experience weight stigma. Two online experiments were conducted in which participants viewed either a stigmatizing or a positive photograph of an obese model. In Experiment 1 (N = 146), participants viewed a photograph of either a Caucasian or African American obese woman; in Experiment 2 (N = 145), participants viewed either a Caucasian male or female obese model. Multiple linear regression models were used to analyze outcomes for social distance attitudes toward the obese models depicted in the images, in addition to other negative attitudes and image preferences. Participants who viewed the stigmatizing images endorsed stronger social distance attitudes and more negative attitudes toward obese persons than participants who viewed the positive images, and there was a stronger preference for the positive images than the stigmatizing images. These results were consistent regardless of the race or gender of the obese model pictured. The findings indicate that more positive media portrayals of obese individuals may help reduce weight stigma and its associated negative health outcomes.

The SPQR experiment: detecting damage to orbiting spacecraft with ground-based telescopes

NASA Astrophysics Data System (ADS)

Paolozzi, Antonio; Porfilio, Manfredi; Currie, Douglas G.; Dantowitz, Ronald F.

2007-09-01

The objective of the Specular Point-like Quick Reference (SPQR) experiment was to evaluate the possibility of improving the resolution of ground-based telescopic imaging of manned spacecraft in orbit. The concept was to reduce image distortions due to atmospheric turbulence by evaluating the Point Spread Function (PSF) of a point-like light reference and processing the spacecraft image accordingly. The target spacecraft was the International Space Station (ISS) and the point-like reference was provided by a laser beam emitted by the ground station and reflected back to the telescope by a Cube Corner Reflector (CCR) mounted on an ISS window. The ultimate objective of the experiment was to demonstrate that it is possible to image spacecraft in Low Earth Orbit (LEO) with a resolution of 20 cm, which would have probably been sufficient to detect the damage which caused the Columbia disaster. The experiment was successfully performed from March to May 2005. The paper provides an overview of the SPQR experiment.

The power of Kawaii: viewing cute images promotes a careful behavior and narrows attentional focus.

PubMed

Nittono, Hiroshi; Fukushima, Michiko; Yano, Akihiro; Moriya, Hiroki

2012-01-01

Kawaii (a Japanese word meaning "cute") things are popular because they produce positive feelings. However, their effect on behavior remains unclear. In this study, three experiments were conducted to examine the effects of viewing cute images on subsequent task performance. In the first experiment, university students performed a fine motor dexterity task before and after viewing images of baby or adult animals. Performance indexed by the number of successful trials increased after viewing cute images (puppies and kittens; M ± SE=43.9 ± 10.3% improvement) more than after viewing images that were less cute (dogs and cats; 11.9 ± 5.5% improvement). In the second experiment, this finding was replicated by using a non-motor visual search task. Performance improved more after viewing cute images (15.7 ± 2.2% improvement) than after viewing less cute images (1.4 ± 2.1% improvement). Viewing images of pleasant foods was ineffective in improving performance (1.2 ± 2.1%). In the third experiment, participants performed a global-local letter task after viewing images of baby animals, adult animals, and neutral objects. In general, global features were processed faster than local features. However, this global precedence effect was reduced after viewing cute images. Results show that participants performed tasks requiring focused attention more carefully after viewing cute images. This is interpreted as the result of a narrowed attentional focus induced by the cuteness-triggered positive emotion that is associated with approach motivation and the tendency toward systematic processing. For future applications, cute objects may be used as an emotion elicitor to induce careful behavioral tendencies in specific situations, such as driving and office work.

The Power of Kawaii: Viewing Cute Images Promotes a Careful Behavior and Narrows Attentional Focus

PubMed Central

Nittono, Hiroshi; Fukushima, Michiko; Yano, Akihiro; Moriya, Hiroki

2012-01-01

Kawaii (a Japanese word meaning “cute”) things are popular because they produce positive feelings. However, their effect on behavior remains unclear. In this study, three experiments were conducted to examine the effects of viewing cute images on subsequent task performance. In the first experiment, university students performed a fine motor dexterity task before and after viewing images of baby or adult animals. Performance indexed by the number of successful trials increased after viewing cute images (puppies and kittens; M ± SE = 43.9±10.3% improvement) more than after viewing images that were less cute (dogs and cats; 11.9±5.5% improvement). In the second experiment, this finding was replicated by using a non-motor visual search task. Performance improved more after viewing cute images (15.7±2.2% improvement) than after viewing less cute images (1.4±2.1% improvement). Viewing images of pleasant foods was ineffective in improving performance (1.2±2.1%). In the third experiment, participants performed a global–local letter task after viewing images of baby animals, adult animals, and neutral objects. In general, global features were processed faster than local features. However, this global precedence effect was reduced after viewing cute images. Results show that participants performed tasks requiring focused attention more carefully after viewing cute images. This is interpreted as the result of a narrowed attentional focus induced by the cuteness-triggered positive emotion that is associated with approach motivation and the tendency toward systematic processing. For future applications, cute objects may be used as an emotion elicitor to induce careful behavioral tendencies in specific situations, such as driving and office work. PMID:23050022

Imaging experiment: The Viking Lander

USGS Publications Warehouse

Mutch, T.A.; Binder, A.B.; Huck, F.O.; Levinthal, E.C.; Morris, E.C.; Sagan, C.; Young, A.T.

1972-01-01

The Viking Lander Imaging System will consist of two identical facsimile cameras. Each camera has a high-resolution mode with an instantaneous field of view of 0.04??, and survey and color modes with instantaneous fields of view of 0.12??. Cameras are positioned one meter apart to provide stereoscopic coverage of the near-field. The Imaging Experiment will provide important information about the morphology, composition, and origin of the Martian surface and atmospheric features. In addition, lander pictures will provide supporting information for other experiments in biology, organic chemistry, meteorology, and physical properties. ?? 1972.

Display gamma is an important factor in Web image viewing

NASA Astrophysics Data System (ADS)

Zhang, Xuemei; Lavin, Yingmei; Silverstein, D. Amnon

2001-06-01

We conducted a perceptual image preference experiment over the web to find our (1) if typical computer users have significant variations in their display gamma settings, and (2) if so, do the gamma settings have significant perceptual effect on the appearance of images in their web browsers. The digital image renderings used were found to have preferred tone characteristics from a previous lab- controlled experiment. They were rendered with 4 different gamma settings. The subjects were asked to view the images over the web, with their own computer equipment and web browsers. The subjects werewe asked to view the images over the web, with their own computer equipment and web browsers. The subjects made pair-wise subjective preference judgements on which rendering they liked bets for each image. Each subject's display gamma setting was estimated using a 'gamma estimator' tool, implemented as a Java applet. The results indicated that (1) the user's gamma settings, as estimated in the experiment, span a wide range from about 1.8 to about 3.0; (2) the subjects preferred images that werewe rendered with a 'correct' gamma value matching their display setting. Subjects disliked images rendered with a gamma value not matching their displays'. This indicates that display gamma estimation is a perceptually significant factor in web image optimization.

Reduced variability of visual left ventricular ejection fraction assessment with reference images: The Japanese Association of Young Echocardiography Fellows multicenter study.

PubMed

Kusunose, Kenya; Shibayama, Kentaro; Iwano, Hiroyuki; Izumo, Masaki; Kagiyama, Nobuyuki; Kurosawa, Koji; Mihara, Hirotsugu; Oe, Hiroki; Onishi, Tetsuari; Onishi, Toshinari; Ota, Mitsuhiko; Sasaki, Shunsuke; Shiina, Yumi; Tsuruta, Hikaru; Tanaka, Hidekazu

2018-07-01

Visual estimation of left ventricular ejection fraction (LVEF) is widely applied to confirm quantitative EF. However, visual assessment is subjective, and variability may be influenced by observer experience. We hypothesized that a learning session might reduce the misclassification rate. Protocol 1: Visual LVEFs for 30 cases were measured by 79 readers from 13 cardiovascular tertiary care centers. Readers were divided into 3 groups by their experience: limited (1-5 years, n=28), intermediate (6-11 years, n=26), and highly experienced (12-years, n=25). Protocol 2: All readers were randomized to assess the effect of a learning session with reference images only or feedback plus reference images. After the session, 20 new cases were shown to all readers following the same methodology. To assess the concordance and accuracy pre- and post-intervention, each visual LVEF measurement was compared to overall average values as a reference. Experience affected the concordance in visual EF values among the readers. Groups with intermediate and high experience showed significantly better mean difference (MD), standard deviation (SD), and coefficient of variation (CV) than those with limited experience at baseline. The learning session with reference image reduced the MD, SD, and CV in readers with limited experience. The learning session with reference images plus feedback also reduced proportional bias. Importantly, the misclassification rate for mid-range EF cases was reduced regardless of experience. This large multicenter study suggested that a simple learning session with reference images can successfully reduce the misclassification rate for LVEF assessment. Copyright © 2018 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

The application of digital techniques to the analysis of metallurgical experiments

NASA Technical Reports Server (NTRS)

Rathz, T. J.

1977-01-01

The application of a specific digital computer system (known as the Image Data Processing System) to the analysis of three NASA-sponsored metallurgical experiments is discussed in some detail. The basic hardware and software components of the Image Data Processing System are presented. Many figures are presented in the discussion of each experimental analysis in an attempt to show the accuracy and speed that the Image Data Processing System affords in analyzing photographic images dealing with metallurgy, and in particular with material processing.

Feasibility study of hidden flow imaging based on laser speckle technique using multiperspectives contrast images

NASA Astrophysics Data System (ADS)

Abookasis, David; Moshe, Tomer

2014-11-01

This paper demonstrates the insertion of lens array in the front of a CCD camera in a laser speckle imaging (LSI) like-technique to acquire multiple speckle reflectance projections for imaging blood flow in an intact biological tissue. In some of LSI applications, flow imaging is obtained by thinning or removing of the upper tissue layers to access blood vessels. In contrast, with the proposed approach flow imaging can be achieved while the tissue is intact. In the system, each lens from an hexagonal lens array observed the sample from slightly different perspectives and captured with a CCD camera. In the computer, these multiview raw images are converted to speckled contrast maps. Then, a self-deconvolution shift-and-add algorithm is employed for processing yields high contrast flow information. The method is experimentally validated first with a plastic tube filled with scattering liquid running at different controlled flow rates hidden in a biological tissue and then extensively tested for imaging of cerebral blood flow in an intact rodent head experience different conditions. A total of fifteen mice were used in the experiments divided randomly into three groups as follows: Group 1 (n=5) consisted of injured mice experience hypoxic ischemic brain injury monitored for ~40 min. Group 2 (n=5) injured mice experience anoxic brain injury monitored up to 20 min. Group 3 (n=5) experience functional activation monitored up to ~35 min. To increase tissue transparency and the penetration depth of photons through head tissue layers, an optical clearing method was employed. To our knowledge, this work presents for the first time the use of lens array in LSI scheme.

Content dependent selection of image enhancement parameters for mobile displays

NASA Astrophysics Data System (ADS)

Lee, Yoon-Gyoo; Kang, Yoo-Jin; Kim, Han-Eol; Kim, Ka-Hee; Kim, Choon-Woo

2011-01-01

Mobile devices such as cellular phones and portable multimedia player with capability of playing terrestrial digital multimedia broadcasting (T-DMB) contents have been introduced into consumer market. In this paper, content dependent image quality enhancement method for sharpness and colorfulness and noise reduction is presented to improve perceived image quality on mobile displays. Human visual experiments are performed to analyze viewers' preference. Relationship between the objective measures and the optimal values of image control parameters are modeled by simple lookup tables based on the results of human visual experiments. Content dependent values of image control parameters are determined based on the calculated measures and predetermined lookup tables. Experimental results indicate that dynamic selection of image control parameters yields better image quality.

Individual Differences in Selective Attention among Prereaders: A Key to Mirror-Image Confusions.

ERIC Educational Resources Information Center

Casey, M. Beth

1986-01-01

Experiment 1 examined the position that mirror-image confusions reflect an inability among three- to five-year-olds to determine whether their performance level differences reflect differences among nonreaders already attending and those not yet attending to reading cues. Experiment 2 examined the Experiment 1 four- and five-year-olds, identified…

The Shuttle Imaging Radar B (SIR-B) experiment report

NASA Technical Reports Server (NTRS)

Cimino, Jo Bea; Holt, Benjamin; Richardson, Annie

1988-01-01

The primary objective of the SIR-B experiment was to acquire multiple-incidence-angle radar imagery of a variety of Earth's surfaces to better understand the effects of imaging geometry on radar backscatter. A complementary objective was to map extensive regions of particular interest. Under these broad objectives, many specific scientific experiments were defined by the 43 SIR-B Science Team members, including studies in the area of geology, vegetation, radar penetration, oceanography, image analysis, and calibration technique development. Approximately 20 percent of the planned digital data were collected, meeting 40 percent of the scientific objectives. This report is an overview of the SIR-B experiment and includes the science investigations, hardware design, mission scenario, mission operations, events of the actual missions, astronaut participation, data products (including auxiliary data), calibrations, and a summary of the actual coverage. Also included are several image samples.

Correlated Imaging – A Grand Challenge in Chemical Analysis

PubMed Central

Masyuko, Rachel; Lanni, Eric; Sweedler, Jonathan V.; Bohn, Paul W.

2013-01-01

Correlated chemical imaging is an emerging strategy for acquisition of images by combining information from multiplexed measurement platforms to track, visualize, and interpret in situ changes in the structure, organization, and activities of interesting chemical systems, frequently spanning multiple decades in space and time. Acquiring and correlating information from complementary imaging experiments has the potential to expose complex chemical behavior in ways that are simply not available from single methods applied in isolation, thereby greatly amplifying the information gathering power of imaging experiments. However, in order to correlate image information across platforms, a number of issues must be addressed. First, signals are obtained from disparate experiments with fundamentally different figures of merit, including pixel size, spatial resolution, dynamic range, and acquisition rates. In addition, images are often acquired on different instruments in different locations, so the sample must be registered spatially so that the same area of the sample landscape is addressed. The signals acquired must be correlated in both spatial and temporal domains, and the resulting information has to be presented in a way that is readily understood. These requirements pose special challenges for image cross-correlation that go well beyond those posed in single technique imaging approaches. The special opportunities and challenges that attend correlated imaging are explored by specific reference to correlated mass spectrometric and Raman imaging, a topic of substantial and growing interest. PMID:23431559

Remote sensing image denoising application by generalized morphological component analysis

NASA Astrophysics Data System (ADS)

Yu, Chong; Chen, Xiong

2014-12-01

In this paper, we introduced a remote sensing image denoising method based on generalized morphological component analysis (GMCA). This novel algorithm is the further extension of morphological component analysis (MCA) algorithm to the blind source separation framework. The iterative thresholding strategy adopted by GMCA algorithm firstly works on the most significant features in the image, and then progressively incorporates smaller features to finely tune the parameters of whole model. Mathematical analysis of the computational complexity of GMCA algorithm is provided. Several comparison experiments with state-of-the-art denoising algorithms are reported. In order to make quantitative assessment of algorithms in experiments, Peak Signal to Noise Ratio (PSNR) index and Structural Similarity (SSIM) index are calculated to assess the denoising effect from the gray-level fidelity aspect and the structure-level fidelity aspect, respectively. Quantitative analysis on experiment results, which is consistent with the visual effect illustrated by denoised images, has proven that the introduced GMCA algorithm possesses a marvelous remote sensing image denoising effectiveness and ability. It is even hard to distinguish the original noiseless image from the recovered image by adopting GMCA algorithm through visual effect.

Adsorption configurations and scanning voltage determined STM images of small hydrogen clusters on bilayer graphene.

PubMed

Cao, Teng Fei; Huang, Liang Feng; Zheng, Xiao Hong; Zhou, Wang Huai; Zeng, Zhi

2013-11-21

By density functional theory calculations, the scanning tunneling microscopy (STM) images of various hydrogen clusters adsorbed on bilayer-graphene are systematically simulated. The hydrogen configurations of the STM images observed in the experiments have been thoroughly figured out. In particular, two kinds of hydrogen dimers (ortho-dimer, para-dimer) and two kinds of tetramers (tetramer-A, -B) are determined to be the hydrogen configurations corresponding to the ellipsoidal-like STM images with different structures and sizes. One particular hexamer (hexamer-B) is the hydrogen configuration generating the star-like STM images. For each hydrogen cluster, the simulated STM images show unique voltage-dependent features, which provides a feasible way to determine hydrogen adsorption states on graphene or graphite surface in the experiments by varying-voltage measurements. Stability analysis proves that the above determined hydrogen configurations are quite stable on graphene, hence they are likely to be detected in the STM experiments. Consequently, through systematic analysis of the STM images and the stability of hydrogen clusters on bilayer graphene, many experimental observations have been consistently explained.

Particle image velocimetry experiments for the IML-I spaceflight. [International Microgravity Laboratory

NASA Technical Reports Server (NTRS)

Trolinger, J. D.; Lal, R. B.; Batra, A. K.; Mcintosh, D.

1991-01-01

The first International Microgravity Laboratory (IML-1), scheduled for spaceflight in early 1992 includes a crystal-growth-from-solution experiment which is equipped with an array of optical diagnostics instrumentation which includes transmission and reflection holography, tomography, schlieren, and particle image displacement velocimetry. During the course of preparation for this spaceflight experiment we have performed both experimentation and analysis for each of these diagnostics. In this paper we describe the work performed in the development of holographic particle image displacement velocimetry for microgravity application which will be employed primarily to observe and quantify minute convective currents in the Spacelab environment and also to measure the value of g. Additionally, the experiment offers a unique opportunity to examine physical phenomena which are normally negligible and not observable. A preliminary analysis of the motion of particles in fluid was performed and supporting experiments were carried out. The results of the analysis and the experiments are reported.

It's like being in another world--patients' lived experience of magnetic resonance imaging.

PubMed

Törnqvist, Erna; Månsson, Asa; Larsson, Elna-Marie; Hallström, Inger

2006-08-01

The aim of this study was to illuminate patients' lived experience during magnetic resonance imaging. Magnetic resonance imaging has increased in importance since the early 1980s and is today a common useful diagnostic tool. Although magnetic resonance imaging are non-invasive and considered painless, many patients experience anxiety, sometimes so strong that the scan has to be terminated. The study had an inductive design and a hermeneutic phenomenological methodology was used. The essential theme of going through magnetic resonance imaging was a feeling of being in another world. The strange environment and isolation inside the scanner made the participants' experiences unusual, with varying degrees of difficulty dealing with it. Being in the other world caused a threat to the participants' self-control. There was a relation between threat to self-control, effort and need for support in the sense that the magnitude of threat to self-control had an impact on the effort it took to handle the situation and on the need for support, and conversely that the support received could affect the effort and threat to self-control. The study shows that the information received and the interaction between patients and staff have a significant influence on patients' lived experiences. The individual experience of threat to self-control requires the need for support to be individualized and care need to be adjusted for each patient.

Imaging cochlear soft tissue displacement with coherent x-rays

NASA Astrophysics Data System (ADS)

Rau, Christoph; Richter, Claus-Peter

2015-10-01

At present, imaging of cochlear mechanics at mid-cochlear turns has not been accomplished. Although challenging, this appears possible with partially coherent hard x-rays. The present study shows results from stroboscopic x-ray imaging of a test object at audio frequencies. The vibration amplitudes were quantified. In a different set of experiments, an intact and calcified gerbil temporal bone was used to determine displacements of the reticular lamina, tectorial membrane, and Reissner’s membrane with the Lucas and Kanade video flow algorithm. The experiments validated high frequency x-ray imaging and imaging in a calcified cochlea. The present work is key for future imaging of cochlear micromechanics at a high spatial resolution.

Recognising the forest, but not the trees: an effect of colour on scene perception and recognition.

PubMed

Nijboer, Tanja C W; Kanai, Ryota; de Haan, Edward H F; van der Smagt, Maarten J

2008-09-01

Colour has been shown to facilitate the recognition of scene images, but only when these images contain natural scenes, for which colour is 'diagnostic'. Here we investigate whether colour can also facilitate memory for scene images, and whether this would hold for natural scenes in particular. In the first experiment participants first studied a set of colour and greyscale natural and man-made scene images. Next, the same images were presented, randomly mixed with a different set. Participants were asked to indicate whether they had seen the images during the study phase. Surprisingly, performance was better for greyscale than for coloured images, and this difference is due to the higher false alarm rate for both natural and man-made coloured scenes. We hypothesized that this increase in false alarm rate was due to a shift from scrutinizing details of the image to recognition of the gist of the (coloured) image. A second experiment, utilizing images without a nameable gist, confirmed this hypothesis as participants now performed equally on greyscale and coloured images. In the final experiment we specifically targeted the more detail-based perception and recognition for greyscale images versus the more gist-based perception and recognition for coloured images with a change detection paradigm. The results show that changes to images are detected faster when image-pairs were presented in greyscale than in colour. This counterintuitive result held for both natural and man-made scenes (but not for scenes without nameable gist) and thus corroborates the shift from more detailed processing of images in greyscale to more gist-based processing of coloured images.

Imaging an Active Volcano Edifice at Tenerife Island, Spain

NASA Astrophysics Data System (ADS)

Ibáñez, Jesús M.; Rietbrock, Andreas; García-Yeguas, Araceli

2008-08-01

An active seismic experiment to study the internal structure of Teide volcano is being carried out on Tenerife, a volcanic island in Spain's Canary Islands archipelago. The main objective of the Tomography at Teide Volcano Spain (TOM-TEIDEVS) experiment, begun in January 2007, is to obtain a three-dimensional (3-D) structural image of Teide volcano using seismic tomography and seismic reflection/refraction imaging techniques. At present, knowledge of the deeper structure of Teide and Tenerife is very limited, with proposed structural models based mainly on sparse geophysical and geological data. The multinational experiment-involving institutes from Spain, the United Kingdom, Italy, Ireland, and Mexico-will generate a unique high-resolution structural image of the active volcano edifice and will further our understanding of volcanic processes.

Comparison of three-dimensional particle tracking and sizing using plenoptic imaging and digital in-line holography.

PubMed

Hall, Elise M; Thurow, Brian S; Guildenbecher, Daniel R

2016-08-10

Digital in-line holography (DIH) and plenoptic photography are two techniques for single-shot, volumetric measurement of 3D particle fields. Here we present a comparison of the two methods by applying plenoptic imaging to experimental configurations that have been previously investigated with DIH. These experiments include the tracking of secondary droplets from the impact of a water drop on a thin film of water and tracking of pellets from a shotgun. Both plenoptic imaging and DIH successfully quantify the 3D nature of these particle fields. This includes measurement of the 3D particle position, individual particle sizes, and three-component velocity vectors. For the initial processing methods presented here, both techniques give out-of-plane positional accuracy of approximately 1-2 particle diameters. For a fixed image sensor, digital holography achieves higher effective in-plane spatial resolutions. However, collimated and coherent illumination makes holography susceptible to image distortion through index of refraction gradients, as demonstrated in the shotgun experiments. In contrast, plenoptic imaging allows for a simpler experimental configuration and, due to the use of diffuse, white-light illumination, plenoptic imaging is less susceptible to image distortion in the shotgun experiments.

Processing of Fear and Anger Facial Expressions: The Role of Spatial Frequency

PubMed Central

Comfort, William E.; Wang, Meng; Benton, Christopher P.; Zana, Yossi

2013-01-01

Spatial frequency (SF) components encode a portion of the affective value expressed in face images. The aim of this study was to estimate the relative weight of specific frequency spectrum bandwidth on the discrimination of anger and fear facial expressions. The general paradigm was a classification of the expression of faces morphed at varying proportions between anger and fear images in which SF adaptation and SF subtraction are expected to shift classification of facial emotion. A series of three experiments was conducted. In Experiment 1 subjects classified morphed face images that were unfiltered or filtered to remove either low (<8 cycles/face), middle (12–28 cycles/face), or high (>32 cycles/face) SF components. In Experiment 2 subjects were adapted to unfiltered or filtered prototypical (non-morphed) fear face images and subsequently classified morphed face images. In Experiment 3 subjects were adapted to unfiltered or filtered prototypical fear face images with the phase component randomized before classifying morphed face images. Removing mid frequency components from the target images shifted classification toward fear. The same shift was observed under adaptation condition to unfiltered and low- and middle-range filtered fear images. However, when the phase spectrum of the same adaptation stimuli was randomized, no adaptation effect was observed. These results suggest that medium SF components support the perception of fear more than anger at both low and high level of processing. They also suggest that the effect at high-level processing stage is related more to high-level featural and/or configural information than to the low-level frequency spectrum. PMID:23637687

A Preliminary Comparison of Three Dimensional Particle Tracking and Sizing using Plenoptic Imaging and Digital In-line Holography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guildenbecher, Daniel Robert; Munz, Elise Dahnke; Farias, Paul Abraham

2015-12-01

Digital in-line holography and plenoptic photography are two techniques for single-shot, volumetric measurement of 3D particle fields. Here we present a preliminary comparison of the two methods by applying plenoptic imaging to experimental configurations that have been previously investigated with digital in-line holography. These experiments include the tracking of secondary droplets from the impact of a water drop on a thin film of water and tracking of pellets from a shotgun. Both plenoptic imaging and digital in-line holography successfully quantify the 3D nature of these particle fields. This includes measurement of the 3D particle position, individual particle sizes, and three-componentmore » velocity vectors. For the initial processing methods presented here, both techniques give out-of-plane positional accuracy of approximately 1-2 particle diameters. For a fixed image sensor, digital holography achieves higher effective in-plane spatial resolutions. However, collimated and coherent illumination makes holography susceptible to image distortion through index of refraction gradients, as demonstrated in the shotgun experiments. On the other hand, plenotpic imaging allows for a simpler experimental configuration. Furthermore, due to the use of diffuse, white-light illumination, plenoptic imaging is less susceptible to image distortion in the shotgun experiments. Additional work is needed to better quantify sources of uncertainty, particularly in the plenoptic experiments, as well as develop data processing methodologies optimized for the plenoptic measurement.« less

A Preliminary Comparison of Three Dimensional Particle Tracking and Sizing using Plenoptic Imaging and Digital In-line Holography [PowerPoint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guildenbecher, Daniel Robert; Munz, Elise Dahnke; Farias, Paul Abraham

2015-12-01

Digital in-line holography and plenoptic photography are two techniques for single-shot, volumetric measurement of 3D particle fields. Here we present a preliminary comparison of the two methods by applying plenoptic imaging to experimental configurations that have been previously investigated with digital in-line holography. These experiments include the tracking of secondary droplets from the impact of a water drop on a thin film of water and tracking of pellets from a shotgun. Both plenoptic imaging and digital in-line holography successfully quantify the 3D nature of these particle fields. This includes measurement of the 3D particle position, individual particle sizes, and three-componentmore » velocity vectors. For the initial processing methods presented here, both techniques give out-of-plane positional accuracy of approximately 1-2 particle diameters. For a fixed image sensor, digital holography achieves higher effective in-plane spatial resolutions. However, collimated and coherent illumination makes holography susceptible to image distortion through index of refraction gradients, as demonstrated in the shotgun experiments. On the other hand, plenotpic imaging allows for a simpler experimental configuration. Furthermore, due to the use of diffuse, white-light illumination, plenoptic imaging is less susceptible to image distortion in the shotgun experiments. Additional work is needed to better quantify sources of uncertainty, particularly in the plenoptic experiments, as well as develop data processing methodologies optimized for the plenoptic measurement.« less

Influence of the light propagation models on a linearized photoacoustic image reconstruction of the light absorption coefficient

NASA Astrophysics Data System (ADS)

Okawa, Shinpei; Hirasawa, Takeshi; Kushibiki, Toshihiro; Ishihara, Miya

2015-03-01

Quantification of the optical properties of the tissues and blood by noninvasive photoacoustic (PA) imaging may provide useful information for screening and early diagnosis of diseases. Linearized 2D image reconstruction algorithm based on PA wave equation and the photon diffusion equation (PDE) can reconstruct the image with computational cost smaller than a method based on 3D radiative transfer equation. However, the reconstructed image is affected by the differences between the actual and assumed light propagations. A quantitative capability of a linearized 2D image reconstruction was investigated and discussed by the numerical simulations and the phantom experiment in this study. The numerical simulations with the 3D Monte Carlo (MC) simulation and the 2D finite element calculation of the PDE were carried out. The phantom experiment was also conducted. In the phantom experiment, the PA pressures were acquired by a probe which had an optical fiber for illumination and the ring shaped P(VDF-TrFE) ultrasound transducer. The measured object was made of Intralipid and Indocyanine green. In the numerical simulations, it was shown that the linearized image reconstruction method recovered the absorption coefficients with alleviating the dependency of the PA amplitude on the depth of the photon absorber. The linearized image reconstruction method worked effectively under the light propagation calculated by 3D MC simulation, although some errors occurred. The phantom experiments validated the result of the numerical simulations.

Full-wave Nonlinear Inverse Scattering for Acoustic and Electromagnetic Breast Imaging

NASA Astrophysics Data System (ADS)

Haynes, Mark Spencer

Acoustic and electromagnetic full-wave nonlinear inverse scattering techniques are explored in both theory and experiment with the ultimate aim of noninvasively mapping the material properties of the breast. There is evidence that benign and malignant breast tissue have different acoustic and electrical properties and imaging these properties directly could provide higher quality images with better diagnostic certainty. In this dissertation, acoustic and electromagnetic inverse scattering algorithms are first developed and validated in simulation. The forward solvers and optimization cost functions are modified from traditional forms in order to handle the large or lossy imaging scenes present in ultrasonic and microwave breast imaging. An antenna model is then presented, modified, and experimentally validated for microwave S-parameter measurements. Using the antenna model, a new electromagnetic volume integral equation is derived in order to link the material properties of the inverse scattering algorithms to microwave S-parameters measurements allowing direct comparison of model predictions and measurements in the imaging algorithms. This volume integral equation is validated with several experiments and used as the basis of a free-space inverse scattering experiment, where images of the dielectric properties of plastic objects are formed without the use of calibration targets. These efforts are used as the foundation of a solution and formulation for the numerical characterization of a microwave near-field cavity-based breast imaging system. The system is constructed and imaging results of simple targets are given. Finally, the same techniques are used to explore a new self-characterization method for commercial ultrasound probes. The method is used to calibrate an ultrasound inverse scattering experiment and imaging results of simple targets are presented. This work has demonstrated the feasibility of quantitative microwave inverse scattering by way of a self-consistent characterization formalism, and has made headway in the same area for ultrasound.

Energy-resolved neutron imaging for inertial confinement fusion

NASA Astrophysics Data System (ADS)

Moran, M. J.; Haan, S. W.; Hatchett, S. P.; Izumi, N.; Koch, J. A.; Lerche, R. A.; Phillips, T. W.

2003-03-01

The success of the National Ignition Facility program will depend on diagnostic measurements which study the performance of inertial confinement fusion (ICF) experiments. Neutron yield, fusion-burn time history, and images are examples of important diagnostics. Neutron and x-ray images will record the geometries of compressed targets during the fusion-burn process. Such images provide a critical test of the accuracy of numerical modeling of ICF experiments. They also can provide valuable information in cases where experiments produce unexpected results. Although x-ray and neutron images provide similar data, they do have significant differences. X-ray images represent the distribution of high-temperature regions where fusion occurs, while neutron images directly reveal the spatial distribution of fusion-neutron emission. X-ray imaging has the advantage of a relatively straightforward path to the imaging system design. Neutron imaging, by using energy-resolved detection, offers the intriguing advantage of being able to provide independent images of burning and nonburning regions of the nuclear fuel. The usefulness of energy-resolved neutron imaging depends on both the information content of the data and on the quality of the data that can be recorded. The information content will relate to the characteristic neutron spectra that are associated with emission from different regions of the source. Numerical modeling of ICF fusion burn will be required to interpret the corresponding energy-dependent images. The exercise will be useful only if the images can be recorded with sufficient definition to reveal the spatial and energy-dependent features of interest. Several options are being evaluated with respect to the feasibility of providing the desired simultaneous spatial and energy resolution.

Research on active imaging information transmission technology of satellite borne quantum remote sensing

NASA Astrophysics Data System (ADS)

Bi, Siwen; Zhen, Ming; Yang, Song; Lin, Xuling; Wu, Zhiqiang

2017-08-01

According to the development and application needs of Remote Sensing Science and technology, Prof. Siwen Bi proposed quantum remote sensing. Firstly, the paper gives a brief introduction of the background of quantum remote sensing, the research status and related researches at home and abroad on the theory, information mechanism and imaging experiments of quantum remote sensing and the production of principle prototype.Then, the quantization of pure remote sensing radiation field, the state function and squeezing effect of quantum remote sensing radiation field are emphasized. It also describes the squeezing optical operator of quantum light field in active imaging information transmission experiment and imaging experiments, achieving 2-3 times higher resolution than that of coherent light detection imaging and completing the production of quantum remote sensing imaging prototype. The application of quantum remote sensing technology can significantly improve both the signal-to-noise ratio of information transmission imaging and the spatial resolution of quantum remote sensing .On the above basis, Prof.Bi proposed the technical solution of active imaging information transmission technology of satellite borne quantum remote sensing, launched researches on its system composition and operation principle and on quantum noiseless amplifying devices, providing solutions and technical basis for implementing active imaging information technology of satellite borne Quantum Remote Sensing.

The importance of the keyword-generation method in keyword mnemonics.

PubMed

Campos, Alfredo; Amor, Angeles; González, María Angeles

2004-01-01

Keyword mnemonics is under certain conditions an effective approach for learning foreign-language vocabulary. It appears to be effective for words with high image vividness but not for words with low image vividness. In this study, two experiments were performed to assess the efficacy of a new keyword-generation procedure (peer generation). In Experiment 1, a sample of 363 high-school students was randomly into four groups. The subjects were required to learn L1 equivalents of a list of 16 Latin words (8 with high image vividness, 8 with low image vividness), using a) the rote method, or the keyword method with b) keywords and images generated and supplied by the experimenter, c) keywords and images generated by themselves, or d) keywords and images previously generated by peers (i.e., subjects with similar sociodemographic characteristics). Recall was tested immediately and one week later. For high-vivideness words, recall was significantly better in the keyword groups than the rote method group. For low-vividness words, learning method had no significant effect. Experiment 2 was basically identical, except that the word lists comprised 32 words (16 high-vividness, 16 low-vividness). In this experiment, the peer-generated-keyword group showed significantly better recall of high-vividness words than the rote method groups and the subject generated keyword group; again, however, learning method had no significant effect on recall of low-vividness words.

Technology study of quantum remote sensing imaging

NASA Astrophysics Data System (ADS)

Bi, Siwen; Lin, Xuling; Yang, Song; Wu, Zhiqiang

2016-02-01

According to remote sensing science and technology development and application requirements, quantum remote sensing is proposed. First on the background of quantum remote sensing, quantum remote sensing theory, information mechanism, imaging experiments and prototype principle prototype research situation, related research at home and abroad are briefly introduced. Then we expounds compress operator of the quantum remote sensing radiation field and the basic principles of single-mode compression operator, quantum quantum light field of remote sensing image compression experiment preparation and optical imaging, the quantum remote sensing imaging principle prototype, Quantum remote sensing spaceborne active imaging technology is brought forward, mainly including quantum remote sensing spaceborne active imaging system composition and working principle, preparation and injection compression light active imaging device and quantum noise amplification device. Finally, the summary of quantum remote sensing research in the past 15 years work and future development are introduced.

Assessing product image quality for online shopping

NASA Astrophysics Data System (ADS)

Goswami, Anjan; Chung, Sung H.; Chittar, Naren; Islam, Atiq

2012-01-01

Assessing product-image quality is important in the context of online shopping. A high quality image that conveys more information about a product can boost the buyer's confidence and can get more attention. However, the notion of image quality for product-images is not the same as that in other domains. The perception of quality of product-images depends not only on various photographic quality features but also on various high level features such as clarity of the foreground or goodness of the background etc. In this paper, we define a notion of product-image quality based on various such features. We conduct a crowd-sourced experiment to collect user judgments on thousands of eBay's images. We formulate a multi-class classification problem for modeling image quality by classifying images into good, fair and poor quality based on the guided perceptual notions from the judges. We also conduct experiments with regression using average crowd-sourced human judgments as target. We compute a pseudo-regression score with expected average of predicted classes and also compute a score from the regression technique. We design many experiments with various sampling and voting schemes with crowd-sourced data and construct various experimental image quality models. Most of our models have reasonable accuracies (greater or equal to 70%) on test data set. We observe that our computed image quality score has a high (0.66) rank correlation with average votes from the crowd sourced human judgments.

Towards a robust HDR imaging system

NASA Astrophysics Data System (ADS)

Long, Xin; Zeng, Xiangrong; Huangpeng, Qizi; Zhou, Jinglun; Feng, Jing

2016-07-01

High dynamic range (HDR) images can show more details and luminance information in general display device than low dynamic image (LDR) images. We present a robust HDR imaging system which can deal with blurry LDR images, overcoming the limitations of most existing HDR methods. Experiments on real images show the effectiveness and competitiveness of the proposed method.

Fear of eyes: triadic relation among social anxiety, trypophobia, and discomfort for eye cluster.

PubMed

Chaya, Kengo; Xue, Yuting; Uto, Yusuke; Yao, Qirui; Yamada, Yuki

2016-01-01

Imagine you are being gazed at by multiple individuals simultaneously. Is the provoked anxiety a learned social-specific response or related to a pathological disorder known as trypophobia? A previous study revealed that spectral properties of images induced aversive reactions in observers with trypophobia. However, it is not clear whether individual differences such as social anxiety traits are related to the discomfort associated with trypophobic images. To investigate this issue, we conducted two experiments with social anxiety and trypophobia and images of eyes and faces. In Experiment 1, participants completed a social anxiety scale and trypophobia questionnaire before evaluation of the discomfort experienced upon exposure to pictures of eye. The results showed that social anxiety had a significant indirect effect on the discomfort associated with the eye clusters, and that the effect was mediated by trypophobia. Experiment 2 replicated Experiment 1 using images of human face. The results showed that, as in Experiment 1, a significant mediation effect of trypophobia was obtained, although the relationship between social anxiety and the discomfort rating was stronger than in Experiment 1. Our findings suggest that both social anxiety and trypophobia contribute to the induction of discomfort when one is gazed at by many people.

GIFTS EDU Ground-based Measurement Experiment

NASA Technical Reports Server (NTRS)

Zhou, Daniel K.; Smith, W. L., Sr.; Zollinger, L. J.; Huppi, R. J.; Reisse, R. A.; Larar, A. M.; Liu, X.; Tansock, J. J., Jr.; Jensen, S. M.; Revercomb, H. E.;

Development of a telediagnosis endoscopy system over secure internet.

PubMed

Ohashi, K; Sakamoto, N; Watanabe, M; Mizushima, H; Tanaka, H

2008-01-01

We developed a new telediagnosis system to securely transmit high-quality endoscopic moving images over the Internet in real time. This system would enable collaboration between physicians seeking advice from endoscopists separated by long distances, to facilitate diagnosis. We adapted a new type of digital video streaming system (DVTS) to our teleendoscopic diagnosis system. To investigate its feasibility, we conducted a two-step experiment. A basic experiment was first conducted to transmit endoscopic video images between hospitals using a plain DVTS. After investigating the practical usability, we incorporated a secure and reliable communication function into the system, by equipping DVTS with "TCP2", a new security technology that establishes secure communication in the transport layer. The second experiment involved international transmission of teleendoscopic image between Hawaii and Japan using the improved system. In both the experiments, no serious transmission delay was observed to disturb physicians' communications and, after subjective evaluation by endoscopists, the diagnostic qualities of the images were found to be adequate. Moreover, the second experiment showed that "TCP2-equipped DVTS" successfully executed high-quality secure image transmission over a long distance network. We conclude that DVTS technology would be promising for teleendoscopic diagnosis. It was also shown that a high quality, secure teleendoscopic diagnosis system can be developed by equipping DVTS with TCP2.

Theory, Image Simulation, and Data Analysis of Chemical Release Experiments

NASA Technical Reports Server (NTRS)

Wescott, Eugene M.

1994-01-01

The final phase of Grant NAG6-1 involved analysis of physics of chemical releases in the upper atmosphere and analysis of data obtained on previous NASA sponsored chemical release rocket experiments. Several lines of investigation of past chemical release experiments and computer simulations have been proceeding in parallel. This report summarizes the work performed and the resulting publications. The following topics are addressed: analysis of the 1987 Greenland rocket experiments; calculation of emission rates for barium, strontium, and calcium; the CRIT 1 and 2 experiments (Collisional Ionization Cross Section experiments); image calibration using background stars; rapid ray motions in ionospheric plasma clouds; and the NOONCUSP rocket experiments.

A study of the method of the video image presentation for the manipulation of forceps.

PubMed

Kono, Soichi; Sekioka, Toshiharu; Matsunaga, Katsuya; Shidoji, Kazunori; Matsuki, Yuji

2005-01-01

Recently, surgical operations have sometimes been tried under laparoscopic video images using teleoperation robots or forceps manipulators. Therefore, in this paper, forceps manipulation efficiencies were evaluated when images for manipulation had some transmission delay (Experiment 1), and when the convergence point of the stereoscopic video cameras was either fixed and variable (Experiment 2). The operators' tasks in these experiments were sewing tasks which simulated telesurgery under 3-dimensional scenography. As a result of experiment 1, the operation at a 200+/-100 ms delay was kept at almost the same accuracy as that without delay. As a result of experiment 2, work accuracy was improved by using the zooming lens function; however the working time became longer. These results seemed to show the relation of a trade-off between working time and working accuracy.

The representation of conceptual knowledge: visual, auditory, and olfactory imagery compared with semantic processing.

PubMed

Palmiero, Massimiliano; Di Matteo, Rosalia; Belardinelli, Marta Olivetti

2014-05-01

Two experiments comparing imaginative processing in different modalities and semantic processing were carried out to investigate the issue of whether conceptual knowledge can be represented in different format. Participants were asked to judge the similarity between visual images, auditory images, and olfactory images in the imaginative block, if two items belonged to the same category in the semantic block. Items were verbally cued in both experiments. The degree of similarity between the imaginative and semantic items was changed across experiments. Experiment 1 showed that the semantic processing was faster than the visual and the auditory imaginative processing, whereas no differentiation was possible between the semantic processing and the olfactory imaginative processing. Experiment 2 revealed that only the visual imaginative processing could be differentiated from the semantic processing in terms of accuracy. These results showed that the visual and auditory imaginative processing can be differentiated from the semantic processing, although both visual and auditory images strongly rely on semantic representations. On the contrary, no differentiation is possible within the olfactory domain. Results are discussed in the frame of the imagery debate.

Research Issues in Image Registration for Remote Sensing

NASA Technical Reports Server (NTRS)

Eastman, Roger D.; LeMoigne, Jacqueline; Netanyahu, Nathan S.

2007-01-01

Image registration is an important element in data processing for remote sensing with many applications and a wide range of solutions. Despite considerable investigation the field has not settled on a definitive solution for most applications and a number of questions remain open. This article looks at selected research issues by surveying the experience of operational satellite teams, application-specific requirements for Earth science, and our experiments in the evaluation of image registration algorithms with emphasis on the comparison of algorithms for subpixel accuracy. We conclude that remote sensing applications put particular demands on image registration algorithms to take into account domain-specific knowledge of geometric transformations and image content.

Imaging learning and memory: classical conditioning.

PubMed

Schreurs, B G; Alkon, D L

2001-12-15

The search for the biological basis of learning and memory has, until recently, been constrained by the limits of technology to classic anatomic and electrophysiologic studies. With the advent of functional imaging, we have begun to delve into what, for many, was a "black box." We review several different types of imaging experiments, including steady state animal experiments that image the functional labeling of fixed tissues, and dynamic human studies based on functional imaging of the intact brain during learning. The data suggest that learning and memory involve a surprising conservation of mechanisms and the integrated networking of a number of structures and processes. Copyright 2001 Wiley-Liss, Inc.

Pioneer: First to Jupiter, Saturn, and beyond. Bibliography

NASA Technical Reports Server (NTRS)

1980-01-01

The reference citatons are grouped by experiment. Experiments include: the charged particle instrument experiment; the ultraviolet photometer experiment; imaging experiments; and magnetometer experiments. The asteroid detector experiment and the plasma analyser experiment are also included.

Coastal Zone Color Scanner (CZCS): Imagery of near-surface phytoplankton pigment concentrations from the first coastal ocean dynamics experiment (CODE-1), March - July 1981

NASA Technical Reports Server (NTRS)

Abbott, M. R.; Zion, P. M.

1984-01-01

As part of the first Coastal Ocean Dynamics Experiment, images of ocean color were collected from late March until late July, 1981, by the Coastal Zone Color Scanner aboard Nimbus-7. Images that had sufficient cloud-free area to be of interest were processed to yield near-surface phytoplankton pigment concentrations. These images were then remapped to a fixed equal-area grid. This report contains photographs of the digital images and a brief description of the processing methods.

Automatic segmentation of time-lapse microscopy images depicting a live Dharma embryo.

PubMed

Zacharia, Eleni; Bondesson, Maria; Riu, Anne; Ducharme, Nicole A; Gustafsson, Jan-Åke; Kakadiaris, Ioannis A

2011-01-01

Biological inferences about the toxicity of chemicals reached during experiments on the zebrafish Dharma embryo can be greatly affected by the analysis of the time-lapse microscopy images depicting the embryo. Among the stages of image analysis, automatic and accurate segmentation of the Dharma embryo is the most crucial and challenging. In this paper, an accurate and automatic segmentation approach for the segmentation of the Dharma embryo data obtained by fluorescent time-lapse microscopy is proposed. Experiments performed in four stacks of 3D images over time have shown promising results.

Taxonomy of Individual Variations in Aesthetic Responses to Fractal Patterns

PubMed Central

Spehar, Branka; Walker, Nicholas; Taylor, Richard P.

2016-01-01

In two experiments, we investigate group and individual preferences in a range of different types of patterns with varying fractal-like scaling characteristics. In Experiment 1, we used 1/f filtered grayscale images as well as their thresholded (black and white) and edges only counterparts. Separate groups of observers viewed different types of images varying in slope of their amplitude spectra. Although with each image type, the groups exhibited the “universal” pattern of preference for intermediate amplitude spectrum slopes, we identified 4 distinct sub-groups in each case. Sub-group 1 exhibited a typical peak preference for intermediate amplitude spectrum slopes (“intermediate”; approx. 50%); sub-group 2 exhibited a linear increase in preference with increasing amplitude spectrum slope (“smooth”; approx. 20%), while sub-group 3 exhibited a linear decrease in preference as a function of the amplitude spectrum slope (“sharp”; approx. 20%). Sub-group 4 revealed no significant preference (“other”; approx. 10%). In Experiment 2, we extended the range of different image types and investigated preferences within the same observers. We replicate the results of our first experiment and show that individual participants exhibit stable patterns of preference across a wide range of image types. In both experiments, Q-mode factor analysis identified two principal factors that were able to explain more than 80% of interindividual variations in preference across all types of images, suggesting a highly similar dimensional structure of interindividual variations in preference for fractal-like scaling characteristics. PMID:27458365

Measurements of Low-Frequency Acoustic Attenuation in Soils.

DTIC Science & Technology

1994-10-13

Engineering Research Laboratory to design an acoustic subsurface imaging system, a set of experiments was conducted in which the attenuation and the velocity...support of the U.S. Army Construction Engineering Research Laboratory’s efforts to design an acoustic subsurface imaging system which would ideally be...of acoustic waves such as those generated by a subsurface imaging system. An experiment reported in the literature characterized the acoustic

Remote sensing image segmentation based on Hadoop cloud platform

NASA Astrophysics Data System (ADS)

Li, Jie; Zhu, Lingling; Cao, Fubin

2018-01-01

To solve the problem that the remote sensing image segmentation speed is slow and the real-time performance is poor, this paper studies the method of remote sensing image segmentation based on Hadoop platform. On the basis of analyzing the structural characteristics of Hadoop cloud platform and its component MapReduce programming, this paper proposes a method of image segmentation based on the combination of OpenCV and Hadoop cloud platform. Firstly, the MapReduce image processing model of Hadoop cloud platform is designed, the input and output of image are customized and the segmentation method of the data file is rewritten. Then the Mean Shift image segmentation algorithm is implemented. Finally, this paper makes a segmentation experiment on remote sensing image, and uses MATLAB to realize the Mean Shift image segmentation algorithm to compare the same image segmentation experiment. The experimental results show that under the premise of ensuring good effect, the segmentation rate of remote sensing image segmentation based on Hadoop cloud Platform has been greatly improved compared with the single MATLAB image segmentation, and there is a great improvement in the effectiveness of image segmentation.

Fourier Analysis and Structure Determination. Part II: Pulse NMR and NMR Imaging.

ERIC Educational Resources Information Center

Chesick, John P.

1989-01-01

Uses simple pulse NMR experiments to discuss Fourier transforms. Studies the generation of spin echoes used in the imaging procedure. Shows that pulse NMR experiments give signals that are additions of sinusoids of differing amplitudes, frequencies, and phases. (MVL)

Imaging Research With Non-Periodic Multilayers for Inertial Confinement Fusion Diagnostic Experiments

NASA Astrophysics Data System (ADS)

L. Wang, F.; Mu, B. Z.; Wang, Z. S.; Gu, C. S.; Zhang, Z.; Qin, S. J.; Chen, L. Y.

A grazing Kirkpatrick-Baez (K-B) microscope was designed for hard x-ray (8keV; Cu Ka radiation) imaging in Inertial Confinement Fusion (ICF) diagnostic experiments. Ray tracing software was used to simulate optical system performance. The optimized theoretical resolution of K-B microscope was about 2 micron and better than 10 micron in 200 micron field of view. Tungsten and boron carbide were chosen as multilayer materials and the multilayer was deposited onto the silicon wafer substrate and the reflectivity was measured by x-ray diffraction (XRD). The reflectivity of supermirror was about 20 % in 0.3 % of bandwidth. 8keV Cu target x-ray tube source was used in x-ray imaging experiments and the magnification of 1x and 2x x-ray images were obtained.

Validating a Geographical Image Retrieval System.

ERIC Educational Resources Information Center

Zhu, Bin; Chen, Hsinchun

2000-01-01

Summarizes a prototype geographical image retrieval system that demonstrates how to integrate image processing and information analysis techniques to support large-scale content-based image retrieval. Describes an experiment to validate the performance of this image retrieval system against that of human subjects by examining similarity analysis…

Laboratory demonstration of image reconstruction for coherent optical system of modular imaging collectors (COSMIC)

NASA Technical Reports Server (NTRS)

Traub, W. A.

1984-01-01

The first physical demonstration of the principle of image reconstruction using a set of images from a diffraction-blurred elongated aperture is reported. This is an optical validation of previous theoretical and numerical simulations of the COSMIC telescope array (coherent optical system of modular imaging collectors). The present experiment utilizes 17 diffraction blurred exposures of a laboratory light source, as imaged by a lens covered by a narrow-slit aperture; the aperture is rotated 10 degrees between each exposure. The images are recorded in digitized form by a CCD camera, Fourier transformed, numerically filtered, and added; the sum is then filtered and inverse Fourier transformed to form the final image. The image reconstruction process is found to be stable with respect to uncertainties in values of all physical parameters such as effective wavelength, rotation angle, pointing jitter, and aperture shape. Future experiments will explore the effects of low counting rates, autoguiding on the image, various aperture configurations, and separated optics.

Image stitching and image reconstruction of intestines captured using radial imaging capsule endoscope

NASA Astrophysics Data System (ADS)

Ou-Yang, Mang; Jeng, Wei-De; Wu, Yin-Yi; Dung, Lan-Rong; Wu, Hsien-Ming; Weng, Ping-Kuo; Huang, Ker-Jer; Chiu, Luan-Jiau

2012-05-01

This study investigates image processing using the radial imaging capsule endoscope (RICE) system. First, an experimental environment is established in which a simulated object has a shape that is similar to a cylinder, such that a triaxial platform can be used to push the RICE into the sample and capture radial images. Then four algorithms (mean absolute error, mean square error, Pearson correlation coefficient, and deformation processing) are used to stitch the images together. The Pearson correlation coefficient method is the most effective algorithm because it yields the highest peak signal-to-noise ratio, higher than 80.69 compared to the original image. Furthermore, a living animal experiment is carried out. Finally, the Pearson correlation coefficient method and vector deformation processing are used to stitch the images that were captured in the living animal experiment. This method is very attractive because unlike the other methods, in which two lenses are required to reconstruct the geometrical image, RICE uses only one lens and one mirror.

Automatic colorimetric calibration of human wounds

PubMed Central

2010-01-01

Background Recently, digital photography in medicine is considered an acceptable tool in many clinical domains, e.g. wound care. Although ever higher resolutions are available, reproducibility is still poor and visual comparison of images remains difficult. This is even more the case for measurements performed on such images (colour, area, etc.). This problem is often neglected and images are freely compared and exchanged without further thought. Methods The first experiment checked whether camera settings or lighting conditions could negatively affect the quality of colorimetric calibration. Digital images plus a calibration chart were exposed to a variety of conditions. Precision and accuracy of colours after calibration were quantitatively assessed with a probability distribution for perceptual colour differences (dE_ab). The second experiment was designed to assess the impact of the automatic calibration procedure (i.e. chart detection) on real-world measurements. 40 Different images of real wounds were acquired and a region of interest was selected in each image. 3 Rotated versions of each image were automatically calibrated and colour differences were calculated. Results 1st Experiment: Colour differences between the measurements and real spectrophotometric measurements reveal median dE_ab values respectively 6.40 for the proper patches of calibrated normal images and 17.75 for uncalibrated images demonstrating an important improvement in accuracy after calibration. The reproducibility, visualized by the probability distribution of the dE_ab errors between 2 measurements of the patches of the images has a median of 3.43 dE* for all calibrated images, 23.26 dE_ab for all uncalibrated images. If we restrict ourselves to the proper patches of normal calibrated images the median is only 2.58 dE_ab! Wilcoxon sum-rank testing (p < 0.05) between uncalibrated normal images and calibrated normal images with proper squares were equal to 0 demonstrating a highly significant improvement of reproducibility. In the second experiment, the reproducibility of the chart detection during automatic calibration is presented using a probability distribution of dE_ab errors between 2 measurements of the same ROI. Conclusion The investigators proposed an automatic colour calibration algorithm that ensures reproducible colour content of digital images. Evidence was provided that images taken with commercially available digital cameras can be calibrated independently of any camera settings and illumination features. PMID:20298541

Web Mining for Web Image Retrieval.

ERIC Educational Resources Information Center

Chen, Zheng; Wenyin, Liu; Zhang, Feng; Li, Mingjing; Zhang, Hongjiang

2001-01-01

Presents a prototype system for image retrieval from the Internet using Web mining. Discusses the architecture of the Web image retrieval prototype; document space modeling; user log mining; and image retrieval experiments to evaluate the proposed system. (AEF)

Perspective: Advanced particle imaging

DOE PAGES

Chandler, David W.; Houston, Paul L.; Parker, David H.

2017-05-26

This study discuss, the first ion imaging experiment demonstrating the capability of collecting an image of the photofragments from a unimolecular dissociation event and analyzing that image to obtain the three-dimensional velocity distribution of the fragments, the efficacy and breadth of application of the ion imaging technique have continued to improve and grow. With the addition of velocity mapping, ion/electron centroiding, and slice imaging techniques, the versatility and velocity resolution have been unmatched. Recent improvements in molecular beam, laser, sensor, and computer technology are allowing even more advanced particle imaging experiments, and eventually we can expect multi-mass imaging with co-variancemore » and full coincidence capability on a single shot basis with repetition rates in the kilohertz range. This progress should further enable “complete” experiments—the holy grail of molecular dynamics—where all quantum numbers of reactants and products of a bimolecular scattering event are fully determined and even under our control.« less

The HRSC on Mars Express: Mert Davies' Involvement in a Novel Planetary Cartography Experiment

NASA Astrophysics Data System (ADS)

Oberst, J.; Waehlisch, M.; Giese, B.; Scholten, F.; Hoffmann, H.; Jaumann, R.; Neukum, G.

2002-12-01

Mert Davies was a team member of the HRSC (High Resolution Stereo Camera) imaging experiment (PI: Gerhard Neukum) on ESA's Mars Express mission. This pushbroom camera is equipped with 9 forward- and backward-looking CCD lines, 5184 samples each, mounted in parallel, perpendicular to the spacecraft velocity vector. Flight image data with resolutions of up to 10m/pix (from an altitude of 250 km) will be acquired line by line as the spacecraft moves. This acquisition strategy will result in 9 separate almost completely overlapping image strips, each of them having more than 27,000 image lines, typically. [HRSC is also equipped with a superresolution channel for imaging of selected targets at up to 2.3 m/pixel]. The combined operation of the nadir and off-nadir CCD lines (+18.9°, 0°, -18.9°) gives HRSC a triple-stereo capability for precision mapping of surface topography and for modelling of spacecraft orbit- and camera pointing errors. The goals of the camera are to obtain accurate control point networks, Digital Elevation Models (DEMs) in Mars-fixed coordinates, and color orthoimages at global (100% of the surface will be covered with resolutions better than 30m/pixel) and local scales. With his long experience in all aspects of planetary geodesy and cartography, Mert Davies was involved in the preparations of this novel Mars imaging experiment which included: (a) development of a ground data system for the analysis of triple-stereo images, (b) camera testing during airborne imaging campaigns, (c) re-analysis of the Mars control point network, and generation of global topographic orthoimage maps on the basis of MOC images and MOLA data, (d) definition of the quadrangle scheme for a new topographic image map series 1:200K, (e) simulation of synthetic HRSC imaging sequences and their photogrammetric analysis. Mars Express is scheduled for launch in May of 2003. We miss Mert very much!

Image quality of the cat eye measured during retinal ganglion cell experiments

PubMed Central

Bonds, A. B.; Enroth-Cugell, Christina; Pinto, L. H.

1972-01-01

1. The modulation transfer function (MTF) of the dioptrics of fifteen cat eyes was determined. The aerial image, formed by the eye of a standard object (a 0·5-1·0° annulus), was photographed. The transmission of the film negative was measured with a scanning microdensitometer to yield the light distribution within the aerial image. Correcting for the double passage, this experimentally determined light distribution and the known object light distribution were used to obtain the MTF, applying Fourier methods. Each MTF was used to calculate the light distribution within the retinal image of stimuli of various geometry used in experiments on retinal ganglion cells in the same eye. 2. When the eye was equipped with an artificial pupil of the same size as that used in the neurophysiological experiments (4·0-4·8 mm diam.) the MTF had fallen to 0·5 at 2·43 c/deg. When the pupil was removed the MTF had fallen to 0·5 at a much lower spatial frequency (1·0 c/deg). This shows that even when one uses an artificial pupil too large to provide optimal image quality there is a vast improvement over using no pupil. 3. These image quality measurements were prompted by the need to know the actual stimulus image in experiments on the functional organization of the receptive field, a need exemplified in this paper by a few specific physiological results. The full neurophysiological results appear in the next two papers. ImagesFig. 3Fig. 4 PMID:5014105

Galileo Optical Experiment GOPEX

NASA Image and Video Library

1996-02-08

Two sets of laser pulses transmitted from Earth to a spacecraft over a distance of 1.4 million kilometers 870,000 miles in a communications experiment are shown in this long-exposure image made by NASA’s Galileo spacecraft imaging system. http://photojournal.jpl.nasa.gov/catalog/PIA00230

Not looking yourself: The cost of self-selecting photographs for identity verification.

PubMed

White, David; Burton, Amy L; Kemp, Richard I

2016-05-01

Photo-identification is based on the premise that photographs are representative of facial appearance. However, previous studies show that ratings of likeness vary across different photographs of the same face, suggesting that some images capture identity better than others. Two experiments were designed to examine the relationship between likeness judgments and face matching accuracy. In Experiment 1, we compared unfamiliar face matching accuracy for self-selected and other-selected high-likeness images. Surprisingly, images selected by previously unfamiliar viewers - after very limited exposure to a target face - were more accurately matched than self-selected images chosen by the target identity themselves. Results also revealed extremely low inter-rater agreement in ratings of likeness across participants, suggesting that perceptions of image resemblance are inherently unstable. In Experiment 2, we test whether the cost of self-selection can be explained by this general disagreement in likeness judgments between individual raters. We find that averaging across rankings by multiple raters produces image selections that provide superior identification accuracy. However, benefit of other-selection persisted for single raters, suggesting that inaccurate representations of self interfere with our ability to judge which images faithfully represent our current appearance. © 2015 The British Psychological Society.

Multispectral imaging of plant stress for detection of CO2 leaking from underground

NASA Astrophysics Data System (ADS)

Rouse, J.; Shaw, J. A.; Repasky, K. S.; Lawrence, R. L.

2008-12-01

Multispectral imaging of plant stress is a potentially useful method of detecting CO2 leaking from underground. During the summers of 2007 and 2008, we deployed a multispectral imager for vegetation sensing as part of an underground CO2 release experiment conducted at the Zero Emission Research and Technology (ZERT) field site near the Montana State University campus in Bozeman, Montana. The imager was mounted on a low tower and observed the vegetation in a region near an underground pipe during a multi-week CO2 release. The imager was calibrated to measure absolute reflectance, from which vegetation indices were calculated as a measure of vegetation health. The temporal evolution of these indices over the course of the experiment show that the vegetation nearest the pipe exhibited more stress than the vegetation located further from the pipe. The imager observed notably increased stress in vegetation at locations exhibiting particularly high flux of CO2 from the ground into the atmosphere. These data from the 2007 and 2008 experiments will be used to demonstrate the utility of a tower-mounted multispectral imaging system for detecting CO2 leakage from below ground with the ability to operate continuously during clear and cloudy conditions.

Visual mental image generation does not overlap with visual short-term memory: a dual-task interference study.

PubMed

Borst, Gregoire; Niven, Elaine; Logie, Robert H

2012-04-01

Visual mental imagery and working memory are often assumed to play similar roles in high-order functions, but little is known of their functional relationship. In this study, we investigated whether similar cognitive processes are involved in the generation of visual mental images, in short-term retention of those mental images, and in short-term retention of visual information. Participants encoded and recalled visually or aurally presented sequences of letters under two interference conditions: spatial tapping or irrelevant visual input (IVI). In Experiment 1, spatial tapping selectively interfered with the retention of sequences of letters when participants generated visual mental images from aural presentation of the letter names and when the letters were presented visually. In Experiment 2, encoding of the sequences was disrupted by both interference tasks. However, in Experiment 3, IVI interfered with the generation of the mental images, but not with their retention, whereas spatial tapping was more disruptive during retention than during encoding. Results suggest that the temporary retention of visual mental images and of visual information may be supported by the same visual short-term memory store but that this store is not involved in image generation.

In Situ 3D Coherent X-ray Diffraction Imaging of Shock Experiments: Possible?

NASA Astrophysics Data System (ADS)

Barber, John

2011-03-01

In traditional coherent X-ray diffraction imaging (CXDI), a 2D or quasi-2D object is illuminated by a beam of coherent X-rays to produce a diffraction pattern, which is then manipulated via a process known as iterative phase retrieval to reconstruct an image of the original 2D sample. Recently, there have been dramatic advances in methods for performing fully 3D CXDI of a sample from a single diffraction pattern [Raines et al, Nature 463 214-7 (2010)], and these methods have been used to image samples tens of microns in size using soft X-rays. In this work, I explore the theoretical possibility of applying 3D CXDI techniques to the in situ imaging of the interaction between a shock front and a polycrystal, a far more stringent problem. A delicate trade-off is required between photon energy, spot size, imaging resolution, and the dimensions of the experimental setup. In this talk, I will outline the experimental and computational requirements for performing such an experiment, and I will present images and movies from simulations of one such hypothetical experiment, including both the time-resolved X-ray diffraction patterns and the time-resolved sample imagery.

Psychophysical studies of the performance of an image database retrieval system

NASA Astrophysics Data System (ADS)

Papathomas, Thomas V.; Conway, Tiffany E.; Cox, Ingemar J.; Ghosn, Joumana; Miller, Matt L.; Minka, Thomas P.; Yianilos, Peter N.

1998-07-01

We describe psychophysical experiments conducted to study PicHunter, a content-based image retrieval (CBIR) system. Experiment 1 studies the importance of using (a) semantic information, (2) memory of earlier input and (3) relative, rather than absolute, judgements of image similarity. The target testing paradigm is used in which a user must search for an image identical to a target. We find that the best performance comes from a version of PicHunter that uses only semantic cues, with memory and relative similarity judgements. Second best is use of both pictorial and semantic cues, with memory and relative similarity judgements. Most reports of CBIR systems provide only qualitative measures of performance based on how similar retrieved images are to a target. Experiment 2 puts PicHunter into this context with a more rigorous test. We first establish a baseline for our database by measuring the time required to find an image that is similar to a target when the images are presented in random order. Although PicHunter's performance is measurably better than this, the test is weak because even random presentation of images yields reasonably short search times. This casts doubt on the strength of results given in other reports where no baseline is established.

Computer-aided analysis for the Mechanics of Granular Materials (MGM) experiment

NASA Technical Reports Server (NTRS)

Parker, Joey K.

1986-01-01

The Mechanics of Granular Materials (MGM) program is planned to provide experimental determinations of the mechanics of granular materials under very low gravity conditions. The initial experiments will use small glass beads as the granular material, and a precise tracking of individual beads during the test is desired. Real-time video images of the experimental specimen were taken with a television camera, and subsequently digitized by a frame grabber installed in a microcomputer. Easily identified red tracer beads were randomly scattered throughout the test specimen. A set of Pascal programs was written for processing and analyzing the digitized images. Filtering the image with Laplacian, dilation, and blurring filters when using a threshold function produced a binary (black on white) image which clearly identified the red beads. The centroids and areas for each bead were then determined. Analyzing a series of the images determined individual red bead displacements throughout the experiment. The system can provide displacement accuracies on the order of 0.5 to 1 pixel is the image is taken directly from the video camera. Digitizing an image from a video cassette recorder introduces an additional repeatability error of 0.5 to 1 pixel. Other programs were written to provide hardcopy prints of the digitized images on a dot-matrix printer.

The application of digital image plane holography technology to identify Chinese herbal medicine

NASA Astrophysics Data System (ADS)

Wang, Huaying; Guo, Zhongjia; Liao, Wei; Zhang, Zhihui

2012-03-01

In this paper, the imaging technology of digital image plane holography to identify the Chinese herbal medicine is studied. The optical experiment system of digital image plane holography which is the special case of pre-magnification digital holography was built. In the record system, one is an object light by using plane waves which illuminates the object, and the other one is recording hologram by using spherical light wave as reference light. There is a Micro objective lens behind the object. The second phase factor which caus ed by the Micro objective lens can be eliminated by choosing the proper position of the reference point source when digital image plane holography is recorded by spherical light. In this experiment, we use the Lygodium cells and Onion cells as the object. The experiment results with Lygodium cells and Onion cells show that digital image plane holography avoid the process of finding recording distance by using auto-focusing approach, and the phase information of the object can be reconstructed more accurately. The digital image plane holography is applied to the microscopic imaging of cells more effectively, and it is suit to apply for the identify of Chinese Herbal Medicine. And it promotes the application of digital holographic in practice.

Comparison of three-dimensional particle tracking and sizing using plenoptic imaging and digital in-line holography

DOE PAGES

Hall, Elise M.; Thurow, Brian S.; Guildenbecher, Daniel R.

2016-08-08

Digital in-line holography (DIH) and plenoptic photography are two techniques for single-shot, volumetric measurement of 3D particle fields. Here we present a comparison of the two methods by applying plenoptic imaging to experimental configurations that have been previously investigated with DIH. These experiments include the tracking of secondary droplets from the impact of a water drop on a thin film of water and tracking of pellets from a shotgun. Both plenoptic imaging and DIH successfully quantify the 3D nature of these particle fields. Furthermore, this includes measurement of the 3D particle position, individual particle sizes, and three-component velocity vectors. Formore » the initial processing methods presented here, both techniques give out-of-plane positional accuracy of approximately 1–2 particle diameters. For a fixed image sensor, digital holography achieves higher effective in-plane spatial resolutions. However, collimated and coherent illumination makes holography susceptible to image distortion through index of refraction gradients, as demonstrated in the shotgun experiments. In contrast, plenoptic imaging allows for a simpler experimental configuration and, due to the use of diffuse, white-light illumination, plenoptic imaging is less susceptible to image distortion in the shotgun experiments.« less

Remote sensing with spaceborne synthetic aperture imaging radars: A review

NASA Technical Reports Server (NTRS)

Cimino, J. B.; Elachi, C.

1983-01-01

A review is given of remote sensing with Spaceborne Synthetic Aperture Radars (SAR's). In 1978, a spaceborne SA was flown on the SEASAT satellite. It acquired high resulution images over many regions in North America and the North Pacific. The acquired data clearly demonstrate the capability of spaceborne SARs to: image and track polar ice floes; image ocean surface patterns including swells, internal waves, current boundaries, weather boundaries and vessels; and image land features which are used to acquire information about the surface geology and land cover. In 1981, another SAR was flown on the second shuttle flight. This Shuttle Imaging Radar (SIR-A) acquired land and ocean images over many areas around the world. The emphasis of the SIR-A experiment was mainly toward geologic mapping. Some of the key results of the SIR-A experiment are given.

The Use of Enteric Contrast Media for Diagnostic CT, MRI, and Ultrasound in Infants and Children: A Practical Approach.

PubMed

Callahan, Michael J; Talmadge, Jennifer M; MacDougall, Robert; Buonomo, Carlo; Taylor, George A

2016-05-01

Enteric contrast media are commonly administered for diagnostic cross-sectional imaging studies in the pediatric population. The purpose of this manuscript is to review the use of enteric contrast media for CT, MRI, and ultrasound in infants, children, and adolescents and to share our experiences at a large tertiary care pediatric teaching hospital. The use of enteric contrast material for diagnostic imaging in infants and children continues to evolve with advances in imaging technology and available enteric contrast media. Many principles of enteric contrast use in pediatric imaging are similar to those in adult imaging, but important differences must be kept in mind when imaging the gastrointestinal tract in infants and children, and practical ways to optimize the imaging examination and the patient experience should be employed where possible.

Imaging photonic crystals using hemispherical digital condensers and phase-recovery techniques.

PubMed

Alotaibi, Maged; Skinner-Ramos, Sueli; Farooq, Hira; Alharbi, Nouf; Alghasham, Hawra; de Peralta, Luis Grave

2018-05-10

We describe experiments where Fourier ptychographic microscopy (FPM) and dual-space microscopy (DSM) are implemented for imaging photonic crystals using a hemispherical digital condenser (HDC). Phase-recovery imaging simulations show that both techniques should be able to image photonic crystals with a period below the Rayleigh resolution limit. However, after processing the experimental images using both phase-recovery algorithms, we found that DSM can, but FPM cannot, image periodic structures with a period below the diffraction limit. We studied the origin of this apparent contradiction between simulations and experiments, and we concluded that the occurrence of unwanted reflections in the HDC is the source of the apparent failure of FPM. We thereafter solved the problem of reflections by using a single-directional illumination source and showed that FPM can image photonic crystals with a period below the Rayleigh resolution limit.

Tradeoff between picture element dimensions and noncoherent averaging in side-looking airborne radar

NASA Technical Reports Server (NTRS)

Moore, R. K.

1979-01-01

An experiment was performed in which three synthetic-aperture images and one real-aperture image were successively degraded in spatial resolution, both retaining the same number of independent samples per pixel and using the spatial degradation to allow averaging of different numbers of independent samples within each pixel. The original and degraded images were provided to three interpreters familiar with both aerial photographs and radar images. The interpreters were asked to grade each image in terms of their ability to interpret various specified features on the image. The numerical interpretability grades were then used as a quantitative measure of the utility of the different kinds of image processing and different resolutions. The experiment demonstrated empirically that the interpretability is related exponentially to the SGL volume which is the product of azimuth, range, and gray-level resolution.

Processing Translational Motion Sequences.

DTIC Science & Technology

1982-10-01

the initial ROADSIGN image using a (del)**2g mask with a width of 5 pixels The distinctiveness values were computed using features which were 5x5 pixel...the initial step size of the local search quite large. 34 4. EX P R g NTg The following experiments were performed using the roadsign and industrial...the initial image of the sequence. The third experiment involves processing the roadsign image sequence using the features extracted at the positions

3D reconstruction of internal structure of animal body using near-infrared light

NASA Astrophysics Data System (ADS)

Tran, Trung Nghia; Yamamoto, Kohei; Namita, Takeshi; Kato, Yuji; Shimizu, Koichi

2014-03-01

To realize three-dimensional (3D) optical imaging of the internal structure of animal body, we have developed a new technique to reconstruct CT images from two-dimensional (2D) transillumination images. In transillumination imaging, the image is blurred due to the strong scattering in the tissue. We had developed a scattering suppression technique using the point spread function (PSF) for a fluorescent light source in the body. In this study, we have newly proposed a technique to apply this PSF for a light source to the image of unknown light-absorbing structure. The effectiveness of the proposed technique was examined in the experiments with a model phantom and a mouse. In the phantom experiment, the absorbers were placed in the tissue-equivalent medium to simulate the light-absorbing organs in mouse body. Near-infrared light was illuminated from one side of the phantom and the image was recorded with CMOS camera from another side. Using the proposed techniques, the scattering effect was efficiently suppressed and the absorbing structure can be visualized in the 2D transillumination image. Using the 2D images obtained in many different orientations, we could reconstruct the 3D image. In the mouse experiment, an anesthetized mouse was held in an acrylic cylindrical holder. We can visualize the internal organs such as kidneys through mouse's abdomen using the proposed technique. The 3D image of the kidneys and a part of the liver were reconstructed. Through these experimental studies, the feasibility of practical 3D imaging of the internal light-absorbing structure of a small animal was verified.

A novel scheme for automatic nonrigid image registration using deformation invariant feature and geometric constraint

NASA Astrophysics Data System (ADS)

Deng, Zhipeng; Lei, Lin; Zhou, Shilin

2015-10-01

Automatic image registration is a vital yet challenging task, particularly for non-rigid deformation images which are more complicated and common in remote sensing images, such as distorted UAV (unmanned aerial vehicle) images or scanning imaging images caused by flutter. Traditional non-rigid image registration methods are based on the correctly matched corresponding landmarks, which usually needs artificial markers. It is a rather challenging task to locate the accurate position of the points and get accurate homonymy point sets. In this paper, we proposed an automatic non-rigid image registration algorithm which mainly consists of three steps: To begin with, we introduce an automatic feature point extraction method based on non-linear scale space and uniform distribution strategy to extract the points which are uniform distributed along the edge of the image. Next, we propose a hybrid point matching algorithm using DaLI (Deformation and Light Invariant) descriptor and local affine invariant geometric constraint based on triangulation which is constructed by K-nearest neighbor algorithm. Based on the accurate homonymy point sets, the two images are registrated by the model of TPS (Thin Plate Spline). Our method is demonstrated by three deliberately designed experiments. The first two experiments are designed to evaluate the distribution of point set and the correctly matching rate on synthetic data and real data respectively. The last experiment is designed on the non-rigid deformation remote sensing images and the three experimental results demonstrate the accuracy, robustness, and efficiency of the proposed algorithm compared with other traditional methods.

Gray-scale transform and evaluation for digital x-ray chest images on CRT monitor

NASA Astrophysics Data System (ADS)

Furukawa, Isao; Suzuki, Junji; Ono, Sadayasu; Kitamura, Masayuki; Ando, Yutaka

1997-04-01

In this paper, an experimental evaluation of a super high definition (SHD) imaging system for digital x-ray chest images is presented. The SHD imaging system is proposed as a platform for integrating conventional image media. We are involved in the use of SHD images in the total digitizing of medical records that include chest x-rays and pathological microscopic images, both which demand the highest level of quality among the various types of medical images. SHD images use progressive scanning and have a spatial resolution of 2000 by 2000 pixels or more and a temporal resolution (frame rate) of 60 frames/sec or more. For displaying medical x-ray images on a CRT, we derived gray scale transform characteristics based on radiologists' comments during the experiment, and elucidated the relationship between that gray scale transform and the linearization transform for maintaining the linear relationship with the luminance of film on a light box (luminance linear transform). We then carried out viewing experiments based on a five-stage evaluation. Nine radiologists participated in our experiment, and the ten cases evaluated included pulmonary fibrosis, lung cancer, and pneumonia. The experimental results indicated that conventional film images and those on super high definition CRT monitors have nearly the same quality. They also show that the gray scale transform for CRT images decided according to radiologists' comments agrees with the luminance linear transform in the high luminance region. And in the low luminance region, it was found that the gray scale transform had the characteristics of level expansion to increase the number of levels that can be expressed.

Visual long-term memory and change blindness: Different effects of pre- and post-change information on one-shot change detection using meaningless geometric objects.

PubMed

Nishiyama, Megumi; Kawaguchi, Jun

2014-11-01

To clarify the relationship between visual long-term memory (VLTM) and online visual processing, we investigated whether and how VLTM involuntarily affects the performance of a one-shot change detection task using images consisting of six meaningless geometric objects. In the study phase, participants observed pre-change (Experiment 1), post-change (Experiment 2), or both pre- and post-change (Experiment 3) images appearing in the subsequent change detection phase. In the change detection phase, one object always changed between pre- and post-change images and participants reported which object was changed. Results showed that VLTM of pre-change images enhanced the performance of change detection, while that of post-change images decreased accuracy. Prior exposure to both pre- and post-change images did not influence performance. These results indicate that pre-change information plays an important role in change detection, and that information in VLTM related to the current task does not always have a positive effect on performance. Copyright © 2014 Elsevier Inc. All rights reserved.

Experiment research on infrared targets signature in mid and long IR spectral bands

NASA Astrophysics Data System (ADS)

Wang, Chensheng; Hong, Pu; Lei, Bo; Yue, Song; Zhang, Zhijie; Ren, Tingting

2013-09-01

Since the infrared imaging system has played a significant role in the military self-defense system and fire control system, the radiation signature of IR target becomes an important topic in IR imaging application technology. IR target signature can be applied in target identification, especially for small and dim targets, as well as the target IR thermal design. To research and analyze the targets IR signature systematically, a practical and experimental project is processed under different backgrounds and conditions. An infrared radiation acquisition system based on a MWIR cooled thermal imager and a LWIR cooled thermal imager is developed to capture the digital infrared images. Furthermore, some instruments are introduced to provide other parameters. According to the original image data and the related parameters in a certain scene, the IR signature of interested target scene can be calculated. Different background and targets are measured with this approach, and a comparison experiment analysis shall be presented in this paper as an example. This practical experiment has proved the validation of this research work, and it is useful in detection performance evaluation and further target identification research.

Automated analysis of siRNA screens of cells infected by hepatitis C and dengue viruses based on immunofluorescence microscopy images

NASA Astrophysics Data System (ADS)

Matula, Petr; Kumar, Anil; Wörz, Ilka; Harder, Nathalie; Erfle, Holger; Bartenschlager, Ralf; Eils, Roland; Rohr, Karl

2008-03-01

We present an image analysis approach as part of a high-throughput microscopy siRNA-based screening system using cell arrays for the identification of cellular genes involved in hepatitis C and dengue virus replication. Our approach comprises: cell nucleus segmentation, quantification of virus replication level in the neighborhood of segmented cell nuclei, localization of regions with transfected cells, cell classification by infection status, and quality assessment of an experiment and single images. In particular, we propose a novel approach for the localization of regions of transfected cells within cell array images, which combines model-based circle fitting and grid fitting. By this scheme we integrate information from single cell array images and knowledge from the complete cell arrays. The approach is fully automatic and has been successfully applied to a large number of cell array images from screening experiments. The experimental results show a good agreement with the expected behaviour of positive as well as negative controls and encourage the application to screens from further high-throughput experiments.

Adaptive Optical System for Retina Imaging Approaches Clinic Applications

NASA Astrophysics Data System (ADS)

Ling, N.; Zhang, Y.; Rao, X.; Wang, C.; Hu, Y.; Jiang, W.; Jiang, C.

We presented "A small adaptive optical system on table for human retinal imaging" at the 3rd Workshop on Adaptive Optics for Industry and Medicine. In this system, a 19 element small deformable mirror was used as wavefront correction element. High resolution images of photo receptors and capillaries of human retina were obtained. In recent two years, at the base of this system a new adaptive optical system for human retina imaging has been developed. The wavefront correction element is a newly developed 37 element deformable mirror. Some modifications have been adopted for easy operation. Experiments for different imaging wavelengths and axial positions were conducted. Mosaic pictures of photoreceptors and capillaries were obtained. 100 normal and abnormal eyes of different ages have been inspected.The first report in the world concerning the most detailed capillary distribution images cover ±3° by ± 3° field around the fovea has been demonstrated. Some preliminary very early diagnosis experiment has been tried in laboratory. This system is being planned to move to the hospital for clinic experiments.

Photo-reconnaissance applications of computer processing of images.

NASA Technical Reports Server (NTRS)

Billingsley, F. C.

1971-01-01

An imaging processing technique is developed for enhancement and calibration of imaging experiments. The technique is shown to be useful not only for the original application but also when applied to images from a wide variety of sources.

Image quality of the cat eye measured during retinal ganglion cell experiments.

PubMed

Bonds, A B; Enroth-Cugell, C; Pinto, L H

1972-01-01

1. The modulation transfer function (MTF) of the dioptrics of fifteen cat eyes was determined. The aerial image, formed by the eye of a standard object (a 0.5-1.0 degrees annulus), was photographed. The transmission of the film negative was measured with a scanning microdensitometer to yield the light distribution within the aerial image. Correcting for the double passage, this experimentally determined light distribution and the known object light distribution were used to obtain the MTF, applying Fourier methods. Each MTF was used to calculate the light distribution within the retinal image of stimuli of various geometry used in experiments on retinal ganglion cells in the same eye.2. When the eye was equipped with an artificial pupil of the same size as that used in the neurophysiological experiments (4.0-4.8 mm diam.) the MTF had fallen to 0.5 at 2.43 c/deg. When the pupil was removed the MTF had fallen to 0.5 at a much lower spatial frequency (1.0 c/deg). This shows that even when one uses an artificial pupil too large to provide optimal image quality there is a vast improvement over using no pupil.3. These image quality measurements were prompted by the need to know the actual stimulus image in experiments on the functional organization of the receptive field, a need exemplified in this paper by a few specific physiological results. The full neurophysiological results appear in the next two papers.

Esthetics and psyche-part 1: assessment of the influence of patients' perceptions of body image and body experience on selection of existing natural tooth color.

PubMed

Bauer, Julia; Vasilache, Iliana; Schlegel, Andreas Karl; Wichmann, Manfred; Eitner, Stephan

2012-01-01

The aim of this research was to test the hypothesis that patients' attitudes toward their body affect their capacity to accurately select their existing natural tooth color. Standard validated psychologic assessments were used to determine a person's perception of body image and experience. Oral images were compared with the patients' perceptions of their natural tooth color, which were then compared with the actual tooth color judged by a dental professional. For the vital body dynamic and disliking body experience subscales, women exhibited a significantly more negative attitude toward their bodies than men (P = .000). Patients with a negative attitude toward their body tended to choose a lighter tooth color. The correlation between patients' and the testing physician's choices of color was r = 0.540 for women and r = 0.746 for men. Unhappiness with body image and experience results in poor perception of a patient's own oral image, which in turn results in a patient perceiving that his or her natural tooth color is lighter than that judged by a dental professional. This has clinical implications when trying to achieve patient satisfaction with dental prostheses.

Ultrahigh sensitivity endoscopic camera using a new CMOS image sensor: providing with clear images under low illumination in addition to fluorescent images.

PubMed

Aoki, Hisae; Yamashita, Hiromasa; Mori, Toshiyuki; Fukuyo, Tsuneo; Chiba, Toshio

2014-11-01

We developed a new ultrahigh-sensitive CMOS camera using a specific sensor that has a wide range of spectral sensitivity characteristics. The objective of this study is to present our updated endoscopic technology that has successfully integrated two innovative functions; ultrasensitive imaging as well as advanced fluorescent viewing. Two different experiments were conducted. One was carried out to evaluate the function of the ultrahigh-sensitive camera. The other was to test the availability of the newly developed sensor and its performance as a fluorescence endoscope. In both studies, the distance from the endoscopic tip to the target was varied and those endoscopic images in each setting were taken for further comparison. In the first experiment, the 3-CCD camera failed to display the clear images under low illumination, and the target was hardly seen. In contrast, the CMOS camera was able to display the targets regardless of the camera-target distance under low illumination. Under high illumination, imaging quality given by both cameras was quite alike. In the second experiment as a fluorescence endoscope, the CMOS camera was capable of clearly showing the fluorescent-activated organs. The ultrahigh sensitivity CMOS HD endoscopic camera is expected to provide us with clear images under low illumination in addition to the fluorescent images under high illumination in the field of laparoscopic surgery.

Pornographic image detection with Gabor filters

NASA Astrophysics Data System (ADS)

Durrell, Kevan; Murray, Daniel J. C.

2002-04-01

As Internet-enabled computers become ubiquitous in homes, schools, and other publicly accessible locations, there are more people 'surfing the net' who would prefer not to be exposed to offensive material. There is a lot of material freely available on the Internet that we, as a responsible and caring society, would like to keep our children from viewing. Pornographic image content is one category of material over which we would like some control. We have been conducting experiments to determine the effectiveness of using characteristic feature vectors and neural networks to identify semantic image content. This paper will describe our approach to identifying pornographic images using Gabor filters, Principal Component Analysis (PCA), Correllograms, and Neural Networks. In brief, we used a set of 5,000 typical images available from the Internet, 20% of which were judged to be pornographic, to train a neural network. We then apply the trained neural network to feature vectors from images that had not been used in training. We measure our performance as Recall, how many of the verification images labeled pornographic were correctly identified, and Precision, how many images deemed pornographic by the neural network are in fact pornographic. The set of images that were used in the experiment described in this paper for its training and validation sets are freely available on the Internet. Freely available is an important qualifier, since high-resolution, studio-quality pornographic images are often protected by portals that charge members a fee to gain access to their material. Although this is not a hard and fast rule, many of the pornographic images that are available easily and without charge on the Internet are of low image quality. Some of these images are collages or contain textual elements or have had their resolution intentionally lowered to reduce their file size. These are the offensive images that a user, without a credit card, might inadvertently come across on the Internet. Identifying this type of pornographic pictures of low image quality poses particular challenges for any detection software. This paper will address some of the challenges and hurdles we faced in designing and carrying out our experiments. The paper will also discuss the main results of our experiments, as well as some confounds that, at present, limit the effectiveness of our approach to identifying pornographic images, and some directions that may be taken in future research.

An automated image-collection system for crystallization experiments using SBS standard microplates.

PubMed

Brostromer, Erik; Nan, Jie; Su, Xiao Dong

2007-02-01

As part of a structural genomics platform in a university laboratory, a low-cost in-house-developed automated imaging system for SBS microplate experiments has been designed and constructed. The imaging system can scan a microplate in 2-6 min for a 96-well plate depending on the plate layout and scanning options. A web-based crystallization database system has been developed, enabling users to follow their crystallization experiments from a web browser. As the system has been designed and built by students and crystallographers using commercially available parts, this report is aimed to serve as a do-it-yourself example for laboratory robotics.

Coherent Diffractive Imaging: From Nanometric Down to Picometric Resolution

NASA Astrophysics Data System (ADS)

De Caro, Liberato; Carlino, Elvio; Siliqi, Dritan; Giannini, Cinzia

Coherent diffractive imaging (CDI) is a novel technique for inspecting (crystalline and non-crystalline) matter from nanometric down to picometric resolution. It was used originally with X-rays and, more recently, with electrons (so-called electron diffractive imaging, or EDI). This chapter introduces basic concepts concerning CDI and addresses the different types of X-ray CDI experiments that have been conducted, namely plane wave CDI from isolated objects in forward scattering, focused-beam Fresnel CDI from isolated objects in forward scattering, Bragg CDI from nanocrystals, and keyhole CDI and ptychography from extended objects. A CDI experiment with a transmission electron microscope, alternatively named an EDI experiment, is also introduced.

Modifications to the synthetic aperture microwave imaging diagnostic.

PubMed

Brunner, K J; Chorley, J C; Dipper, N A; Naylor, G; Sharples, R M; Taylor, G; Thomas, D A; Vann, R G L

2016-11-01

The synthetic aperture microwave imaging diagnostic has been operating on the MAST experiment since 2011. It has provided the first 2D images of B-X-O mode conversion windows and showed the feasibility of conducting 2D Doppler back-scattering experiments. The diagnostic heavily relies on field programmable gate arrays to conduct its work. Recent successes and newly gained experience with the diagnostic have led us to modify it. The enhancements will enable pitch angle profile measurements, O and X mode separation, and the continuous acquisition of 2D DBS data. The diagnostic has also been installed on the NSTX-U and is acquiring data since May 2016.

The contribution of physical activity and media use during childhood and adolescence to adult women's body image.

PubMed

Slater, Amy; Tiggemann, Marika

2006-07-01

This study aimed to investigate the effects of both past and current physical activity and media use on women's body image. A sample of 144 female undergraduate students completed measures of current physical activity, media use and body image, as well as providing retrospective reports of their physical activity participation and media usage during childhood and adolescence. Regression analyses showed that childhood experiences of physical activity and media use predicted adult body-image concerns more strongly than current activities. It was concluded that early experiences of both physical activity and media use during childhood and adolescence play an important role in the development of adult women's body image.

Midcourse Space Experiment Data Certification and Technology Transfer

NASA Technical Reports Server (NTRS)

Pollock, David B.

1997-01-01

The University of Alabama in Huntsville contributes to the Technical Management of the Midcourse Space Experiment Program, to the Certification of the Level 2 data produced by the Midcourse Space Experiment's suite of in-orbit imaging radiometers, imaging spectra-radiometers and an interferometer and to the Transfer of the Midcourse Space Experiment Technology to other Government Programs. The Technical Management of the Midcourse Space Experiment Program is expected to continue through out the spacecraft's useful life time, 5 years after its 1996 launch. The Transfer of Midcourse Space Experiment Technology to other government elements is expected to be on a demand basis by the United States Government and other organizations. The University of Alabama Huntsville' contribution specifically supports the nine Ultraviolet Visible Imagers and Spectrographic Imagers (UVISI) and the Pointing and Alignment of all eleven of the science instruments. The science instruments effectively cover the 0.1 to 28 micron spectral region. The Midcourse Space Experiment spacecraft, launched April 24, 1996, is expected to have a 5 year useful lifetime with a 12 month lifetime for the cryogenically cooled IR sensor. A pre-launch, ground based calibration of the instruments provided a basis for the pre-launch certification of the Level 2 data base these instruments produce. With the spacecraft in-orbit the certification of the instruments' Level 2 data base is being extended to the in-orbit environment.

Transducer Design Experiments for Ground-Penetrating Acoustic Systems

DTIC Science & Technology

1996-03-19

subsurface imaging experiments have utilized a source (Tx) and receiver (Rx) configuration in which signals produced by a transmitter at the soil surface...development in the field of acoustic subsurface imaging are as follows. First, a transmitter designed to minimize the emission of surface waves, while

Exploring Feminist Women's Body Consciousness

ERIC Educational Resources Information Center

Rubin, Lisa R.; Nemeroff, Carol J.; Russo, Nancy Felipe

2004-01-01

In a qualitative investigation of young feminists' experience of body consciousness, 25 feminist women each participated in one of 6 focus groups examining the ways they experienced body image and negotiated cultural messages about women's appearance. Participants described their experience with objectification and its impact on their body image,…

Fear of eyes: triadic relation among social anxiety, trypophobia, and discomfort for eye cluster

PubMed Central

Xue, Yuting; Uto, Yusuke; Yao, Qirui; Yamada, Yuki

2016-01-01

Imagine you are being gazed at by multiple individuals simultaneously. Is the provoked anxiety a learned social-specific response or related to a pathological disorder known as trypophobia? A previous study revealed that spectral properties of images induced aversive reactions in observers with trypophobia. However, it is not clear whether individual differences such as social anxiety traits are related to the discomfort associated with trypophobic images. To investigate this issue, we conducted two experiments with social anxiety and trypophobia and images of eyes and faces. In Experiment 1, participants completed a social anxiety scale and trypophobia questionnaire before evaluation of the discomfort experienced upon exposure to pictures of eye. The results showed that social anxiety had a significant indirect effect on the discomfort associated with the eye clusters, and that the effect was mediated by trypophobia. Experiment 2 replicated Experiment 1 using images of human face. The results showed that, as in Experiment 1, a significant mediation effect of trypophobia was obtained, although the relationship between social anxiety and the discomfort rating was stronger than in Experiment 1. Our findings suggest that both social anxiety and trypophobia contribute to the induction of discomfort when one is gazed at by many people. PMID:27168967

Inelastic neutron scattering experiments with the monochromatic imaging mode of the RITA-II spectrometer

NASA Astrophysics Data System (ADS)

Bahl, C. R. H.; Lefmann, K.; Abrahamsen, A. B.; Rønnow, H. M.; Saxild, F.; Jensen, T. B. S.; Udby, L.; Andersen, N. H.; Christensen, N. B.; Jakobsen, H. S.; Larsen, T.; Häfliger, P. S.; Streule, S.; Niedermayer, Ch.

2006-05-01

Recently a monochromatic multiple data taking mode has been demonstrated for diffraction experiments using a RITA type cold neutron spectrometer with a multi-bladed analyser and a position-sensitive detector. Here, we show how this mode can be used in combination with a flexible radial collimator to perform real inelastic neutron scattering experiments. We present the results from inelastic powder, single crystal dispersion and single crystal constant energy mapping experiments. The advantages and complications of performing these experiments are discussed along with a comparison between the imaging mode and the traditional monochromatic focussing mode.

The Image of Mathematics Held by Irish Post-Primary Students

ERIC Educational Resources Information Center

Lane, Ciara; Stynes, Martin; O'Donoghue, John

2014-01-01

The image of mathematics held by Irish post-primary students was examined and a model for the image found was constructed. Initially, a definition for "image of mathematics" was adopted with image of mathematics hypothesized as comprising attitudes, beliefs, self-concept, motivation, emotions and past experiences of mathematics. Research…

An evaluation on CT image acquisition method for medical VR applications

NASA Astrophysics Data System (ADS)

Jang, Seong-wook; Ko, Junho; Yoo, Yon-sik; Kim, Yoonsang

2017-02-01

Recent medical virtual reality (VR) applications to minimize re-operations are being studied for improvements in surgical efficiency and reduction of operation error. The CT image acquisition method considering three-dimensional (3D) modeling for medical VR applications is important, because the realistic model is required for the actual human organ. However, the research for medical VR applications has focused on 3D modeling techniques and utilized 3D models. In addition, research on a CT image acquisition method considering 3D modeling has never been reported. The conventional CT image acquisition method involves scanning a limited area of the lesion for the diagnosis of doctors once or twice. However, the medical VR application is required to acquire the CT image considering patients' various postures and a wider area than the lesion. A wider area than the lesion is required because of the necessary process of comparing bilateral sides for dyskinesia diagnosis of the shoulder, pelvis, and leg. Moreover, patients' various postures are required due to the different effects on the musculoskeletal system. Therefore, in this paper, we perform a comparative experiment on the acquired CT images considering image area (unilateral/bilateral) and patients' postures (neutral/abducted). CT images are acquired from 10 patients for the experiments, and the acquired CT images are evaluated based on the length per pixel and the morphological deviation. Finally, by comparing the experiment results, we evaluate the CT image acquisition method for medical VR applications.

Impact of assimilating GOES imager clear-sky radiance with a rapid refresh assimilation system for convection-permitting forecast over Mexico

NASA Astrophysics Data System (ADS)

Yang, Chun; Liu, Zhiquan; Gao, Feng; Childs, Peter P.; Min, Jinzhong

2017-05-01

The Geostationary Operational Environmental Satellite (GOES) imager data could provide a continuous image of the evolutionary pattern of severe weather phenomena with its high spatial and temporal resolution. The capability to assimilate the GOES imager radiances has been developed within the Weather Research and Forecasting model's data assimilation system. Compared to the benchmark experiment with no GOES imager data, the impact of assimilating GOES imager radiances on the analysis and forecast of convective process over Mexico in 7-10 March 2016 was assessed through analysis/forecast cycling experiments using rapid refresh assimilation system with hybrid-3DEnVar scheme. With GOES imager radiance assimilation, better analyses were obtained in terms of the humidity, temperature, and simulated water vapor channel brightness temperature distribution. Positive forecast impacts from assimilating GOES imager radiance were seen when verified against the Tropospheric Airborne Meteorological Data Reporting observation, GOES imager observation, and Mexico station precipitation data.

Image Size Variation Influence on Corrupted and Non-viewable BMP Image

NASA Astrophysics Data System (ADS)

Azmi, Tengku Norsuhaila T.; Azma Abdullah, Nurul; Rahman, Nurul Hidayah Ab; Hamid, Isredza Rahmi A.; Chai Wen, Chuah

2017-08-01

Image is one of the evidence component seek in digital forensics. Joint Photographic Experts Group (JPEG) format is most popular used in the Internet because JPEG files are very lossy and easy to compress that can speed up Internet transmitting processes. However, corrupted JPEG images are hard to recover due to the complexities of determining corruption point. Nowadays Bitmap (BMP) images are preferred in image processing compared to another formats because BMP image contain all the image information in a simple format. Therefore, in order to investigate the corruption point in JPEG, the file is required to be converted into BMP format. Nevertheless, there are many things that can influence the corrupting of BMP image such as the changes of image size that make the file non-viewable. In this paper, the experiment indicates that the size of BMP file influences the changes in the image itself through three conditions, deleting, replacing and insertion. From the experiment, we learnt by correcting the file size, it can able to produce a viewable file though partially. Then, it can be investigated further to identify the corruption point.

Cardiovascular applications of magnetic resonance imaging

PubMed Central

Pflugfelder, Peter W.; Wisenberg, Gerald; Prato, Frank S.

1985-01-01

Magnetic resonance (MR) imaging is a unique imaging modality that is gaining rapid acceptance for a variety of medical indications. Diagnostic information is obtained noninvasively, without the potential hazards of ionizing radiation. The spatial resolution and anatomic detail of MR imaging rival those of other currently available imaging methods. By gating to an electrocardiographic signal cardiac imaging is possible. Since March 1983 the authors have had experience with cardiac MR imaging in both animals and humans. Cardiac anatomy is well shown by this technique, which allows detection and characterization of intracardiac masses, congenital heart disease and anomalies of the great vessels. Myocardial infarction has been detected in both animals and humans without the use of contrast agents, and acute cardiac transplant rejection has been visualized in an animal model. Limitations of MR imaging primarily have been lengthy imaging times and the sensitivity of the images to motion. With further investigation and experience this technique may become useful for studying a wide variety of cardiovascular disorders. ImagesFig. 2Fig. 3Fig. 4Fig. 5Fig. 6 PMID:3904969

De-aliasing for signal restoration in Propeller MR imaging.

PubMed

Chiu, Su-Chin; Chang, Hing-Chiu; Chu, Mei-Lan; Wu, Ming-Long; Chung, Hsiao-Wen; Lin, Yi-Ru

2017-02-01

Objects falling outside of the true elliptical field-of-view (FOV) in Propeller imaging show unique aliasing artifacts. This study proposes a de-aliasing approach to restore the signal intensities in Propeller images without extra data acquisition. Computer simulation was performed on the Shepp-Logan head phantom deliberately placed obliquely to examine the signal aliasing. In addition, phantom and human imaging experiments were performed using Propeller imaging with various readouts on a 3.0 Tesla MR scanner. De-aliasing using the proposed method was then performed, with the first low-resolution single-blade image used to find out the aliasing patterns in all the single-blade images, followed by standard Propeller reconstruction. The Propeller images without and with de-aliasing were compared. Computer simulations showed signal loss at the image corners along with aliasing artifacts distributed along directions corresponding to the rotational blades, consistent with clinical observations. The proposed de-aliasing operation successfully restored the correct images in both phantom and human experiments. The de-aliasing operation is an effective adjunct to Propeller MR image reconstruction for retrospective restoration of aliased signals. Copyright © 2016 Elsevier Inc. All rights reserved.

Analysis on the Effect of Sensor Views in Image Reconstruction Produced by Optical Tomography System Using Charge-Coupled Device.

PubMed

Jamaludin, Juliza; Rahim, Ruzairi Abdul; Fazul Rahiman, Mohd Hafiz; Mohd Rohani, Jemmy

2018-04-01

Optical tomography (OPT) is a method to capture a cross-sectional image based on the data obtained by sensors, distributed around the periphery of the analyzed system. This system is based on the measurement of the final light attenuation or absorption of radiation after crossing the measured objects. The number of sensor views will affect the results of image reconstruction, where the high number of sensor views per projection will give a high image quality. This research presents an application of charge-coupled device linear sensor and laser diode in an OPT system. Experiments in detecting solid and transparent objects in crystal clear water were conducted. Two numbers of sensors views, 160 and 320 views are evaluated in this research in reconstructing the images. The image reconstruction algorithms used were filtered images of linear back projection algorithms. Analysis on comparing the simulation and experiments image results shows that, with 320 image views giving less area error than 160 views. This suggests that high image view resulted in the high resolution of image reconstruction.

The Enceladus Atlas

NASA Image and Video Library

2010-05-13

This map sheet covers a 15-series image set covering the entire surface of Enceladus. The map data was acquired by NASA Cassini imaging experiment. Individual images can be viewed via the Photojournal.

Dictionary Learning for Data Recovery in Positron Emission Tomography

PubMed Central

Valiollahzadeh, SeyyedMajid; Clark, John W.; Mawlawi, Osama

2015-01-01

Compressed sensing (CS) aims to recover images from fewer measurements than that governed by the Nyquist sampling theorem. Most CS methods use analytical predefined sparsifying domains such as Total variation (TV), wavelets, curvelets, and finite transforms to perform this task. In this study, we evaluated the use of dictionary learning (DL) as a sparsifying domain to reconstruct PET images from partially sampled data, and compared the results to the partially and fully sampled image (baseline). A CS model based on learning an adaptive dictionary over image patches was developed to recover missing observations in PET data acquisition. The recovery was done iteratively in two steps: a dictionary learning step and an image reconstruction step. Two experiments were performed to evaluate the proposed CS recovery algorithm: an IEC phantom study and five patient studies. In each case, 11% of the detectors of a GE PET/CT system were removed and the acquired sinogram data were recovered using the proposed DL algorithm. The recovered images (DL) as well as the partially sampled images (with detector gaps) for both experiments were then compared to the baseline. Comparisons were done by calculating RMSE, contrast recovery and SNR in ROIs drawn in the background, and spheres of the phantom as well as patient lesions. For the phantom experiment, the RMSE for the DL recovered images were 5.8% when compared with the baseline images while it was 17.5% for the partially sampled images. In the patients’ studies, RMSE for the DL recovered images were 3.8%, while it was 11.3% for the partially sampled images. Our proposed CS with DL is a good approach to recover partially sampled PET data. This approach has implications towards reducing scanner cost while maintaining accurate PET image quantification. PMID:26161630

Magnetoacoustic tomography with magnetic induction for high-resolution bioimepedance imaging through vector source reconstruction under the static field of MRI magnet.

PubMed

Mariappan, Leo; Hu, Gang; He, Bin

2014-02-01

Magnetoacoustic tomography with magnetic induction (MAT-MI) is an imaging modality to reconstruct the electrical conductivity of biological tissue based on the acoustic measurements of Lorentz force induced tissue vibration. This study presents the feasibility of the authors' new MAT-MI system and vector source imaging algorithm to perform a complete reconstruction of the conductivity distribution of real biological tissues with ultrasound spatial resolution. In the present study, using ultrasound beamformation, imaging point spread functions are designed to reconstruct the induced vector source in the object which is used to estimate the object conductivity distribution. Both numerical studies and phantom experiments are performed to demonstrate the merits of the proposed method. Also, through the numerical simulations, the full width half maximum of the imaging point spread function is calculated to estimate of the spatial resolution. The tissue phantom experiments are performed with a MAT-MI imaging system in the static field of a 9.4 T magnetic resonance imaging magnet. The image reconstruction through vector beamformation in the numerical and experimental studies gives a reliable estimate of the conductivity distribution in the object with a ∼ 1.5 mm spatial resolution corresponding to the imaging system frequency of 500 kHz ultrasound. In addition, the experiment results suggest that MAT-MI under high static magnetic field environment is able to reconstruct images of tissue-mimicking gel phantoms and real tissue samples with reliable conductivity contrast. The results demonstrate that MAT-MI is able to image the electrical conductivity properties of biological tissues with better than 2 mm spatial resolution at 500 kHz, and the imaging with MAT-MI under a high static magnetic field environment is able to provide improved imaging contrast for biological tissue conductivity reconstruction.

Dictionary learning for data recovery in positron emission tomography

NASA Astrophysics Data System (ADS)

Valiollahzadeh, SeyyedMajid; Clark, John W., Jr.; Mawlawi, Osama

2015-08-01

Compressed sensing (CS) aims to recover images from fewer measurements than that governed by the Nyquist sampling theorem. Most CS methods use analytical predefined sparsifying domains such as total variation, wavelets, curvelets, and finite transforms to perform this task. In this study, we evaluated the use of dictionary learning (DL) as a sparsifying domain to reconstruct PET images from partially sampled data, and compared the results to the partially and fully sampled image (baseline). A CS model based on learning an adaptive dictionary over image patches was developed to recover missing observations in PET data acquisition. The recovery was done iteratively in two steps: a dictionary learning step and an image reconstruction step. Two experiments were performed to evaluate the proposed CS recovery algorithm: an IEC phantom study and five patient studies. In each case, 11% of the detectors of a GE PET/CT system were removed and the acquired sinogram data were recovered using the proposed DL algorithm. The recovered images (DL) as well as the partially sampled images (with detector gaps) for both experiments were then compared to the baseline. Comparisons were done by calculating RMSE, contrast recovery and SNR in ROIs drawn in the background, and spheres of the phantom as well as patient lesions. For the phantom experiment, the RMSE for the DL recovered images were 5.8% when compared with the baseline images while it was 17.5% for the partially sampled images. In the patients’ studies, RMSE for the DL recovered images were 3.8%, while it was 11.3% for the partially sampled images. Our proposed CS with DL is a good approach to recover partially sampled PET data. This approach has implications toward reducing scanner cost while maintaining accurate PET image quantification.

Whole slide images and digital media in pathology education, testing, and practice: the Oklahoma experience.

PubMed

Fung, Kar-Ming; Hassell, Lewis A; Talbert, Michael L; Wiechmann, Allan F; Chaser, Brad E; Ramey, Joel

2012-01-01

Examination of glass slides is of paramount importance in pathology training. Until the introduction of digitized whole slide images that could be accessed through computer networks, the sharing of pathology slides was a major logistic issue in pathology education and practice. With the help of whole slide images, our department has developed several online pathology education websites. Based on a modular architecture, this program provides online access to whole slide images, still images, case studies, quizzes and didactic text at different levels. Together with traditional lectures and hands-on experiences, it forms the back bone of our histology and pathology education system for residents and medical students. The use of digitized whole slide images has a.lso greatly improved the communication between clinicians and pathologist in our institute.

A Review of Multidimensional, Multifluid Intermediate-scale Experiments: Flow Behavior, Saturation Imaging, and Tracer Detection and Quantification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oostrom, Mart; Dane, J. H.; Wietsma, Thomas W.

2007-08-01

A review is presented of original multidimensional, intermediate-scale experiments involving non-aqueous phase liquid (NAPL) flow behavior, imaging, and detection/quantification with solute tracers. In a companion paper (Oostrom, M., J.H. Dane, and T.W. Wietsma. 2006. A review of multidimensional, multifluid intermediate-scale experiments: Nonaqueous phase dissolution and enhanced remediation. Vadose Zone Journal 5:570-598) experiments related to aqueous dissolution and enhanced remediation were discussed. The experiments investigating flow behavior include infiltration and redistribution experiments with both light and dense NAPLs in homogeneous and heterogeneous porous medium systems. The techniques used for NAPL saturation mapping for intermediate-scale experiments include photon-attenuation methods such as gammamore » and X-ray techniques, and photographic methods such as the light reflection, light transmission, and multispectral image analysis techniques. Solute tracer methods used for detection and quantification of NAPL in the subsurface are primarily limited to variations of techniques comparing the behavior of conservative and partitioning tracers. Besides a discussion of the experimental efforts, recommendations for future research at this laboratory scale are provided.« less

Feasibility study for wax deposition imaging in oil pipelines by PGNAA technique.

PubMed

Cheng, Can; Jia, Wenbao; Hei, Daqian; Wei, Zhiyong; Wang, Hongtao

2017-10-01

Wax deposition in pipelines is a crucial problem in the oil industry. A method based on the prompt gamma-ray neutron activation analysis technique was applied to reconstruct the image of wax deposition in oil pipelines. The 2.223MeV hydrogen capture gamma rays were used to reconstruct the wax deposition image. To validate the method, both MCNP simulation and experiments were performed for wax deposited with a maximum thickness of 20cm. The performance of the method was simulated using the MCNP code. The experiment was conducted with a 252 Cf neutron source and a LaBr 3 : Ce detector. A good correspondence between the simulations and the experiments was observed. The results obtained indicate that the present approach is efficient for wax deposition imaging in oil pipelines. Copyright © 2017 Elsevier Ltd. All rights reserved.

Background oriented schlieren in a density stratified fluid.

PubMed

Verso, Lilly; Liberzon, Alex

2015-10-01

Non-intrusive quantitative fluid density measurement methods are essential in the stratified flow experiments. Digital imaging leads to synthetic schlieren methods in which the variations of the index of refraction are reconstructed computationally. In this study, an extension to one of these methods, called background oriented schlieren, is proposed. The extension enables an accurate reconstruction of the density field in stratified liquid experiments. Typically, the experiments are performed by the light source, background pattern, and the camera positioned on the opposite sides of a transparent vessel. The multimedia imaging through air-glass-water-glass-air leads to an additional aberration that destroys the reconstruction. A two-step calibration and image remapping transform are the key components that correct the images through the stratified media and provide a non-intrusive full-field density measurements of transparent liquids.

Focal-Plane Imaging of Crossed Beams in Nonlinear Optics Experiments

NASA Technical Reports Server (NTRS)

Bivolaru, Daniel; Herring, G. C.

2007-01-01

An application of focal-plane imaging that can be used as a real time diagnostic of beam crossing in various optical techniques is reported. We discuss two specific versions and demonstrate the capability of maximizing system performance with an example in a combined dual-pump coherent anti-Stokes Raman scattering interferometric Rayleigh scattering experiment (CARS-IRS). We find that this imaging diagnostic significantly reduces beam alignment time and loss of CARS-IRS signals due to inadvertent misalignments.

Magnetoacoustic Tomography with Magnetic Induction for Electrical Conductivity based Tissue imaging

NASA Astrophysics Data System (ADS)

Mariappan, Leo

Electrical conductivity imaging of biological tissue has attracted considerable interest in recent years owing to research indicating that electrical properties, especially electrical conductivity and permittivity, are indicators of underlying physiological and pathological conditions in biological tissue. Also, the knowledge of electrical conductivity of biological tissue is of interest to researchers conducting electromagnetic source imaging and in design of devices that apply electromagnetic energy to the body such as MRI. So, the need for a non-invasive, high resolution impedance imaging method is highly desired. To address this need we have studied the magnetoacoustic tomography with magnetic induction (MAT-MI) method. In MAT-MI, the object is placed in a static and a dynamic magnetic field giving rise to ultrasound waves. The dynamic field induces eddy currents in the object, and the static field leads to generation of acoustic vibrations from Lorentz force on the induced currents. The acoustic vibrations are at the same frequency as the dynamic magnetic field, which is chosen to match the ultrasound frequency range. These ultrasound signals can be measured by ultrasound probes and are used to reconstruct MAT-MI acoustic source images using possible ultrasound imaging approaches .The reconstructed high spatial resolution image is indicative of the object's electrical conductivity contrast. We have investigated ultrasound imaging methods to reliably reconstruct the MAT-MI image under the practical conditions of limited bandwidth and transducer geometry. The corresponding imaging algorithm, computer simulation and experiments are developed to test the feasibility of these different methods. Also, in experiments, we have developed a system with the strong static field of an MRI magnet and a strong pulsed magnetic field to evaluate MAT-MI in biological tissue imaging. It can be seen from these simulations and experiments that conductivity boundary images with millimeter resolution can be reliably reconstructed with MAT-MI. Further, to estimate the conductivity distribution throughout the object, we reconstruct a vector source image corresponding to the induced eddy currents. As the current source is uniformly present throughout the object, we are able to reliably estimate the internal conductivity distribution for a more complete imaging. From the computer simulations and experiments it can be seen that MAT-MI method has the potential to be a clinically applicable, high resolution, non-invasive method for electrical conductivity imaging.

Synthetic aperture ultrasound imaging with a ring transducer array: preliminary ex vivo results.

PubMed

Qu, Xiaolei; Azuma, Takashi; Yogi, Takeshi; Azuma, Shiho; Takeuchi, Hideki; Tamano, Satoshi; Takagi, Shu

2016-10-01

The conventional medical ultrasound imaging has a low lateral spatial resolution, and the image quality depends on the depth of the imaging location. To overcome these problems, this study presents a synthetic aperture (SA) ultrasound imaging method using a ring transducer array. An experimental ring transducer array imaging system was constructed. The array was composed of 2048 transducer elements, and had a diameter of 200 mm and an inter-element pitch of 0.325 mm. The imaging object was placed in the center of the ring transducer array, which was immersed in water. SA ultrasound imaging was then employed to scan the object and reconstruct the reflection image. Both wire phantom and ex vivo experiments were conducted. The proposed method was found to be capable of producing isotropic high-resolution images of the wire phantom. In addition, preliminary ex vivo experiments using porcine organs demonstrated the ability of the method to reconstruct high-quality images without any depth dependence. The proposed ring transducer array and SA ultrasound imaging method were shown to be capable of producing isotropic high-resolution images whose quality was independent of depth.

Memory states influence value-based decisions.

PubMed

Duncan, Katherine D; Shohamy, Daphna

2016-11-01

Using memory to guide decisions allows past experience to improve future outcomes. However, the circumstances that modulate how and when memory influences decisions are not well understood. Here, we report that the use of memories to guide decisions depends on the context in which these decisions are made. We show that decisions made in the context of familiar images are more likely to be influenced by past events than are decisions made in the context of novel images (Experiment 1), that this bias persists even when a temporal gap is introduced between the image presentation and the decision (Experiment 2), and that contextual novelty facilitates value learning whereas familiarity facilitates the retrieval and use of previously learned values (Experiment 3). These effects are consistent with neurobiological and computational models of memory, which propose that familiar images evoke a lingering "retrieval state" that facilitates the recollection of other episodic memories. Together, these experiments highlight the importance of episodic memory for decision-making and provide an example of how computational and neurobiological theories can lead to new insights into how and when different types of memories guide our choices. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

The relationship between ambient illumination and psychological factors in viewing of display Images

NASA Astrophysics Data System (ADS)

Iwanami, Takuya; Kikuchi, Ayano; Kaneko, Takashi; Hirai, Keita; Yano, Natsumi; Nakaguchi, Toshiya; Tsumura, Norimichi; Yoshida, Yasuhiro; Miyake, Yoichi

2009-01-01

In this paper, we have clarified the relationship between ambient illumination and psychological factors in viewing of display images. Psychological factors were obtained by the factor analysis with the results of the semantic differential (SD) method. In the psychological experiments, subjects evaluated the impressions of displayed images with changing ambient illuminating conditions. The illumination conditions were controlled by a fluorescent ceiling light and a color LED illumination which was located behind the display. We experimented under two kinds of conditions. One was the experiment with changing brightness of the ambient illumination. The other was the experiment with changing the colors of the background illumination. In the results of the experiment, two factors "realistic sensation, dynamism" and "comfortable," were extracted under different brightness of the ambient illumination of the display surroundings. It was shown that the "comfortable" was improved by the brightness of display surroundings. On the other hand, when the illumination color of surroundings was changed, three factors "comfortable," "realistic sensation, dynamism" and "activity" were extracted. It was also shown that the value of "comfortable" and "realistic sensation, dynamism" increased when the display surroundings were illuminated by the average color of the image contents.

Experimental Demonstration of Longitudinal Magnification

ERIC Educational Resources Information Center

Razpet, Nada; Susman, Katarina; Cepic, Mojca

2009-01-01

We describe an experiment which enables the observation of longitudinal magnification for the real image of a three-dimensional (3D) object formed by a converging lens. The experiment also shows the absence of longitudinal inversion. Possible reasons for misconceptions with respect to real images and longitudinal inversions are discussed and a…

Centroiding Experiment for Determining the Positions of Stars with High Precision

NASA Astrophysics Data System (ADS)

Yano, T.; Araki, H.; Hanada, H.; Tazawa, S.; Gouda, N.; Kobayashi, Y.; Yamada, Y.; Niwa, Y.

2010-12-01

We have experimented with the determination of the positions of star images on a detector with high precision such as 10 microarcseconds, required by a space astrometry satellite, JASMINE. In order to accomplish such a precision, we take the following two procedures. (1) We determine the positions of star images on the detector with the precision of about 0.01 pixel for one measurement, using an algorithm for estimating them from photon weighted means of the star images. (2) We determine the positions of star images with the precision of about 0.0001-0.00001 pixel, which corresponds to that of 10 microarcseconds, using a large amount of data over 10000 measurements, that is, the error of the positions decreases according to the amount of data. Here, we note that the procedure 2 is not accomplished when the systematic error in our data is not excluded adequately even if we use a large amount of data. We first show the method to determine the positions of star images on the detector using photon weighted means of star images. This algorithm, used in this experiment, is very useful because it is easy to calculate the photon weighted mean from the data. This is very important in treating a large amount of data. Furthermore, we need not assume the shape of the point spread function in deriving the centroid of star images. Second, we show the results in the laboratory experiment for precision of determining the positions of star images. We obtain that the precision of estimation of positions of star images on the detector is under a variance of 0.01 pixel for one measurement (procedure 1). We also obtain that the precision of the positions of star images becomes a variance of about 0.0001 pixel using about 10000 measurements (procedure 2).

Intrasubject multimodal groupwise registration with the conditional template entropy.

PubMed

Polfliet, Mathias; Klein, Stefan; Huizinga, Wyke; Paulides, Margarethus M; Niessen, Wiro J; Vandemeulebroucke, Jef

2018-05-01

Image registration is an important task in medical image analysis. Whereas most methods are designed for the registration of two images (pairwise registration), there is an increasing interest in simultaneously aligning more than two images using groupwise registration. Multimodal registration in a groupwise setting remains difficult, due to the lack of generally applicable similarity metrics. In this work, a novel similarity metric for such groupwise registration problems is proposed. The metric calculates the sum of the conditional entropy between each image in the group and a representative template image constructed iteratively using principal component analysis. The proposed metric is validated in extensive experiments on synthetic and intrasubject clinical image data. These experiments showed equivalent or improved registration accuracy compared to other state-of-the-art (dis)similarity metrics and improved transformation consistency compared to pairwise mutual information. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

A universal fluid cell for the imaging of biological specimens in the atomic force microscope.

PubMed

Kasas, Sandor; Radotic, Ksenja; Longo, Giovanni; Saha, Bashkar; Alonso-Sarduy, Livan; Dietler, Giovanni; Roduit, Charles

2013-04-01

Recently, atomic force microscope (AFM) manufacturers have begun producing instruments specifically designed to image biological specimens. In most instances, they are integrated with an inverted optical microscope, which permits concurrent optical and AFM imaging. An important component of the set-up is the imaging chamber, whose design determines the nature of the experiments that can be conducted. Many different imaging chamber designs are available, usually designed to optimize a single parameter, such as the dimensions of the substrate or the volume of fluid that can be used throughout the experiment. In this report, we present a universal fluid cell, which simultaneously optimizes all of the parameters that are important for the imaging of biological specimens in the AFM. This novel imaging chamber has been successfully tested using mammalian, plant, and microbial cells. Copyright © 2013 Wiley Periodicals, Inc.

On pictures and stuff: image quality and material appearance

NASA Astrophysics Data System (ADS)

Ferwerda, James A.

2014-02-01

Realistic images are a puzzle because they serve as visual representations of objects while also being objects themselves. When we look at an image we are able to perceive both the properties of the image and the properties of the objects represented by the image. Research on image quality has typically focused improving image properties (resolution, dynamic range, frame rate, etc.) while ignoring the issue of whether images are serving their role as visual representations. In this paper we describe a series of experiments that investigate how well images of different quality convey information about the properties of the objects they represent. In the experiments we focus on the effects that two image properties (contrast and sharpness) have on the ability of images to represent the gloss of depicted objects. We found that different experimental methods produced differing results. Specifically, when the stimulus images were presented using simultaneous pair comparison, observers were influenced by the surface properties of the images and conflated changes in image contrast and sharpness with changes in object gloss. On the other hand, when the stimulus images were presented sequentially, observers were able to disregard the image plane properties and more accurately match the gloss of the objects represented by the different quality images. These findings suggest that in understanding image quality it is useful to distinguish between quality of the imaging medium and the quality of the visual information represented by that medium.

Adolescents' behavioral and neural responses to e-cigarette advertising.

PubMed

Chen, Yvonnes; Fowler, Carina H; Papa, Vlad B; Lepping, Rebecca J; Brucks, Morgan G; Fox, Andrew T; Martin, Laura E

2018-03-01

Although adolescents are a group heavily targeted by the e-cigarette industry, research in cue-reactivity has not previously examined adolescents' behavioral and neural responses to e-cigarette advertising. This study addressed this gap through two experiments. In Experiment One, adult traditional cigarette smokers (n = 41) and non-smokers (n = 41) answered questions about e-cigarette and neutral advertising images. The 40 e-cigarette advertising images that most increased desire to use the product were matched to 40 neutral advertising images with similar content. In Experiment Two, the 80 advertising images selected in Experiment One were presented to adolescents (n = 30) during an functional magnetic resonance imaging brain scan. There was a range of traditional cigarette smoking across the sample with some adolescents engaging in daily smoking and others who had never smoked. Adolescents self-reported that viewing the e-cigarette advertising images increased their desire to smoke. Additionally, all participants regardless of smoking statuses showed significantly greater brain activation to e-cigarette advertisements in areas associated with cognitive control (left middle frontal gyrus), reward (right medial frontal gyrus), visual processing/attention (left lingual gyrus/fusiform gyrus, right inferior parietal lobule, left posterior cingulate, left angular gyrus) and memory (right parahippocampus, left insula). Further, an exploratory analysis showed that compared with age-matched non-smokers (n = 7), adolescent smokers (n = 7) displayed significantly greater neural activation to e-cigarette advertising images in the left inferior temporal gyrus/fusiform gyrus, compared with their responses to neutral advertising images. Overall, participants' brain responses to e-cigarette advertisements suggest a need to further investigate the long-run impact of e-cigarette advertising on adolescents. © 2017 Society for the Study of Addiction.

The role of external features in face recognition with central vision loss: A pilot study

PubMed Central

Bernard, Jean-Baptiste; Chung, Susana T.L.

2016-01-01

Purpose We evaluated how the performance for recognizing familiar face images depends on the internal (eyebrows, eyes, nose, mouth) and external face features (chin, outline of face, hairline) in individuals with central vision loss. Methods In Experiment 1, we measured eye movements for four observers with central vision loss to determine whether they fixated more often on the internal or the external features of face images while attempting to recognize the images. We then measured the accuracy for recognizing face images that contained only the internal, only the external, or both internal and external features (Experiment 2), and for hybrid images where the internal and external features came from two different source images (Experiment 3), for five observers with central vision loss and four age-matched control observers. Results When recognizing familiar face images, approximately 40% of the fixations of observers with central vision loss were centered on the external features of faces. The recognition accuracy was higher for images containing only external features (66.8±3.3% correct) than for images containing only internal features (35.8±15.0%), a finding contradicting that of control observers. For hybrid face images, observers with central vision loss responded more accurately to the external features (50.4±17.8%) than to the internal features (9.3±4.9%), while control observers did not show the same bias toward responding to the external features. Conclusions Contrary to people with normal vision who rely more on the internal features of face images for recognizing familiar faces, individuals with central vision loss show a higher dependence on using external features of face images. PMID:26829260

The Role of External Features in Face Recognition with Central Vision Loss.

PubMed

Bernard, Jean-Baptiste; Chung, Susana T L

2016-05-01

We evaluated how the performance of recognizing familiar face images depends on the internal (eyebrows, eyes, nose, mouth) and external face features (chin, outline of face, hairline) in individuals with central vision loss. In experiment 1, we measured eye movements for four observers with central vision loss to determine whether they fixated more often on the internal or the external features of face images while attempting to recognize the images. We then measured the accuracy for recognizing face images that contained only the internal, only the external, or both internal and external features (experiment 2) and for hybrid images where the internal and external features came from two different source images (experiment 3) for five observers with central vision loss and four age-matched control observers. When recognizing familiar face images, approximately 40% of the fixations of observers with central vision loss was centered on the external features of faces. The recognition accuracy was higher for images containing only external features (66.8 ± 3.3% correct) than for images containing only internal features (35.8 ± 15.0%), a finding contradicting that of control observers. For hybrid face images, observers with central vision loss responded more accurately to the external features (50.4 ± 17.8%) than to the internal features (9.3 ± 4.9%), whereas control observers did not show the same bias toward responding to the external features. Contrary to people with normal vision who rely more on the internal features of face images for recognizing familiar faces, individuals with central vision loss show a higher dependence on using external features of face images.

High sensitivity optical molecular imaging system

NASA Astrophysics Data System (ADS)

An, Yu; Yuan, Gao; Huang, Chao; Jiang, Shixin; Zhang, Peng; Wang, Kun; Tian, Jie

2018-02-01

Optical Molecular Imaging (OMI) has the advantages of high sensitivity, low cost and ease of use. By labeling the regions of interest with fluorescent or bioluminescence probes, OMI can noninvasively obtain the distribution of the probes in vivo, which play the key role in cancer research, pharmacokinetics and other biological studies. In preclinical and clinical application, the image depth, resolution and sensitivity are the key factors for researchers to use OMI. In this paper, we report a high sensitivity optical molecular imaging system developed by our group, which can improve the imaging depth in phantom to nearly 5cm, high resolution at 2cm depth, and high image sensitivity. To validate the performance of the system, special designed phantom experiments and weak light detection experiment were implemented. The results shows that cooperated with high performance electron-multiplying charge coupled device (EMCCD) camera, precision design of light path system and high efficient image techniques, our OMI system can simultaneously collect the light-emitted signals generated by fluorescence molecular imaging, bioluminescence imaging, Cherenkov luminance and other optical imaging modality, and observe the internal distribution of light-emitting agents fast and accurately.

'What women want': Using image theory to develop expectations of maternity care framework.

PubMed

Clark, Kim; Beatty, Shelley; Reibel, Tracy

2015-05-01

to develop, in consultation with women, a theoretically-grounded framework to guide the assessment of women's maternity-care experiences. qualitative research was undertaken with women to examine the appropriateness of Image Theory as a heuristic for understanding how women plan and evaluate their maternity-care experiences. maternity-care services in metropolitan and regional communities in Western Australia. an Episodes of Maternity Care Framework grounded in Image Theory was established that addressed various domains of women's perceptions and expectations of their maternity-care experience. previously-identified weaknesses of methods used to measure patient satisfaction were addressed and a valid framework for investigating women's perception of their maternity-services experiences was developed. This framework has the potential to contribute to the ongoing development and improvement of maternity-care service. Copyright © 2015 Elsevier Ltd. All rights reserved.

Analyses of requirements for computer control and data processing experiment subsystems. Volume 2: ATM experiment S-056 image data processing system software development

NASA Technical Reports Server (NTRS)

1972-01-01

The IDAPS (Image Data Processing System) is a user-oriented, computer-based, language and control system, which provides a framework or standard for implementing image data processing applications, simplifies set-up of image processing runs so that the system may be used without a working knowledge of computer programming or operation, streamlines operation of the image processing facility, and allows multiple applications to be run in sequence without operator interaction. The control system loads the operators, interprets the input, constructs the necessary parameters for each application, and cells the application. The overlay feature of the IBSYS loader (IBLDR) provides the means of running multiple operators which would otherwise overflow core storage.

Identification of Surface and Near Surface Defects and Damage Evaluation by Laser Speckle Techniques

NASA Technical Reports Server (NTRS)

Gowda, Chandrakanth H.

2001-01-01

As a part of the grant activity, a laboratory was established within the Department of Electrical Engineering for the study for measurements of surface defects and damage evaluation. This facility has been utilized for implementing several algorithms for accurate measurements of defects. Experiments were conducted using simulated images and multiple images were fused to achieve accurate measurements. During the nine months of the grants when the principal investigator was transferred in my name, experiments were conducted using simulated synthetic aperture radar (SAR) images. This proved useful when several algorithms were used on images of smooth objects with minor deformalities. Given the time constraint, the derived algorithms could not be applied to actual images of smooth objects with minor abnormalities.

A spectrum fractal feature classification algorithm for agriculture crops with hyper spectrum image

NASA Astrophysics Data System (ADS)

Su, Junying

2011-11-01

A fractal dimension feature analysis method in spectrum domain for hyper spectrum image is proposed for agriculture crops classification. Firstly, a fractal dimension calculation algorithm in spectrum domain is presented together with the fast fractal dimension value calculation algorithm using the step measurement method. Secondly, the hyper spectrum image classification algorithm and flowchart is presented based on fractal dimension feature analysis in spectrum domain. Finally, the experiment result of the agricultural crops classification with FCL1 hyper spectrum image set with the proposed method and SAM (spectral angle mapper). The experiment results show it can obtain better classification result than the traditional SAM feature analysis which can fulfill use the spectrum information of hyper spectrum image to realize precision agricultural crops classification.

AFFINE-CORRECTED PARADISE: FREE-BREATHING PATIENT-ADAPTIVE CARDIAC MRI WITH SENSITIVITY ENCODING

PubMed Central

Sharif, Behzad; Bresler, Yoram

2013-01-01

We propose a real-time cardiac imaging method with parallel MRI that allows for free breathing during imaging and does not require cardiac or respiratory gating. The method is based on the recently proposed PARADISE (Patient-Adaptive Reconstruction and Acquisition Dynamic Imaging with Sensitivity Encoding) scheme. The new acquisition method adapts the PARADISE k-t space sampling pattern according to an affine model of the respiratory motion. The reconstruction scheme involves multi-channel time-sequential imaging with time-varying channels. All model parameters are adapted to the imaged patient as part of the experiment and drive both data acquisition and cine reconstruction. Simulated cardiac MRI experiments using the realistic NCAT phantom show high quality cine reconstructions and robustness to modeling inaccuracies. PMID:24390159

The Mast Cameras and Mars Descent Imager (MARDI) for the 2009 Mars Science Laboratory

NASA Technical Reports Server (NTRS)

Malin, M. C.; Bell, J. F.; Cameron, J.; Dietrich, W. E.; Edgett, K. S.; Hallet, B.; Herkenhoff, K. E.; Lemmon, M. T.; Parker, T. J.; Sullivan, R. J.

2005-01-01

Based on operational experience gained during the Mars Exploration Rover (MER) mission, we proposed and were selected to conduct two related imaging experiments: (1) an investigation of the geology and short-term atmospheric vertical wind profile local to the Mars Science Laboratory (MSL) landing site using descent imaging, and (2) a broadly-based scientific investigation of the MSL locale employing visible and very near infra-red imaging techniques from a pair of mast-mounted, high resolution cameras. Both instruments share a common electronics design, a design also employed for the MSL Mars Hand Lens Imager (MAHLI) [1]. The primary differences between the cameras are in the nature and number of mechanisms and specific optics tailored to each camera s requirements.

Combining textual and visual information for image retrieval in the medical domain.

PubMed

Gkoufas, Yiannis; Morou, Anna; Kalamboukis, Theodore

2011-01-01

In this article we have assembled the experience obtained from our participation in the imageCLEF evaluation task over the past two years. Exploitation on the use of linear combinations for image retrieval has been attempted by combining visual and textual sources of images. From our experiments we conclude that a mixed retrieval technique that applies both textual and visual retrieval in an interchangeably repeated manner improves the performance while overcoming the scalability limitations of visual retrieval. In particular, the mean average precision (MAP) has increased from 0.01 to 0.15 and 0.087 for 2009 and 2010 data, respectively, when content-based image retrieval (CBIR) is performed on the top 1000 results from textual retrieval based on natural language processing (NLP).

Quantitative analysis of phosphoinositide 3-kinase (PI3K) signaling using live-cell total internal reflection fluorescence (TIRF) microscopy.

PubMed

Johnson, Heath E; Haugh, Jason M

2013-12-02

This unit focuses on the use of total internal reflection fluorescence (TIRF) microscopy and image analysis methods to study the dynamics of signal transduction mediated by class I phosphoinositide 3-kinases (PI3Ks) in mammalian cells. The first four protocols cover live-cell imaging experiments, image acquisition parameters, and basic image processing and segmentation. These methods are generally applicable to live-cell TIRF experiments. The remaining protocols outline more advanced image analysis methods, which were developed in our laboratory for the purpose of characterizing the spatiotemporal dynamics of PI3K signaling. These methods may be extended to analyze other cellular processes monitored using fluorescent biosensors. Copyright © 2013 John Wiley & Sons, Inc.

Geometric error analysis for shuttle imaging spectrometer experiment

NASA Technical Reports Server (NTRS)

Wang, S. J.; Ih, C. H.

1984-01-01

The demand of more powerful tools for remote sensing and management of earth resources steadily increased over the last decade. With the recent advancement of area array detectors, high resolution multichannel imaging spectrometers can be realistically constructed. The error analysis study for the Shuttle Imaging Spectrometer Experiment system is documented for the purpose of providing information for design, tradeoff, and performance prediction. Error sources including the Shuttle attitude determination and control system, instrument pointing and misalignment, disturbances, ephemeris, Earth rotation, etc., were investigated. Geometric error mapping functions were developed, characterized, and illustrated extensively with tables and charts. Selected ground patterns and the corresponding image distortions were generated for direct visual inspection of how the various error sources affect the appearance of the ground object images.

Plans for a new rio-imager experiment in Northern Scandinavia

NASA Astrophysics Data System (ADS)

Nielsen, E.; Hagfors, T.

1997-05-01

To observe the spatial variations and dynamics of charged particle precipitation in the high latitude ionosphere, a riometer experiment is planned, which from the ground will image the precipitation regions over an area of 300 × 300 km with a spatial resolution of 6 km in the zenith, increasing to 12 km at 60° zenith angle. The time resolution is one second. The spatial resolution represents a considerable improvement over existing imaging systems. The experiment employs a Mill's Cross technique not used before in riometer work: two 32 element rows of antennas form the antenna array, two 32 element Butler Matrices achieve directionality, and cross-correlation yield the directional intensities.

Demonstration of x-ray fluorescence imaging of a high-energy-density plasma.

PubMed

MacDonald, M J; Keiter, P A; Montgomery, D S; Biener, M M; Fein, J R; Fournier, K B; Gamboa, E J; Klein, S R; Kuranz, C C; LeFevre, H J; Manuel, M J-E; Streit, J; Wan, W C; Drake, R P

2014-11-01

Experiments at the Trident Laser Facility have successfully demonstrated the use of x-ray fluorescence imaging (XRFI) to diagnose shocked carbonized resorcinol formaldehyde (CRF) foams doped with Ti. One laser beam created a shock wave in the doped foam. A second laser beam produced a flux of vanadium He-α x-rays, which in turn induced Ti K-shell fluorescence within the foam. Spectrally resolved 1D imaging of the x-ray fluorescence provided shock location and compression measurements. Additionally, experiments using a collimator demonstrated that one can probe specific regions within a target. These results show that XRFI is a capable alternative to path-integrated measurements for diagnosing hydrodynamic experiments at high energy density.

Modifications to the synthetic aperture microwave imaging diagnostic

DOE PAGES

Brunner, K. J.; Chorley, J. C.; Dipper, N. A.; ...

2016-09-02

The synthetic aperture microwave imaging diagnostic has been operating on the MAST experiment since 2011. It has provided the first 2D images of B-X-O mode conversion windows and showed the feasibility of conducting 2D Doppler back-scattering experiments. The diagnostic heavily relies on field programmable gate arrays to conduct its work. Recent successes and newly gained experience with the diagnostic have led us to modify it. The enhancements will enable pitch angle profile measurements, O and X mode separation, and the continuous acquisition of 2D DBS data. Finally, the diagnostic has also been installed on the NSTX-U and is acquiring datamore » since May 2016.« less

Body Image in Patients With Spinal Cord Injury During Inpatient Rehabilitation.

PubMed

van Diemen, Tijn; van Leeuwen, Christel; van Nes, Ilse; Geertzen, Jan; Post, Marcel

2017-06-01

(1) To investigate the course of body image in patients with spinal cord injury (SCI) during their first inpatient rehabilitation stay; and (2) to explore the association between demographic and injury-related variables and body image and the association between body image and psychological distress. Longitudinal inception cohort study. Rehabilitation center. Of the 210 people admitted for their first inpatient SCI rehabilitation program (between March 2011 and April 2015), 188 met the inclusion criteria. Of these, N=150 (80%) agreed to participate. Not applicable. The Body Experience Questionnaire was used to measure 2 dimensions of body image: alienation and harmony. Mean scores on the Body Experience Questionnaire alienation subscale decreased significantly during the rehabilitation program. Mean scores on the Body Experience Questionnaire harmony subscale did not increase significantly but showed a trend in the hypothesized direction. The 2 subscales showed weak correlations with demographic and injury-related variables. The 2 subscales together explained 16% and 14% of the variance of depression and anxiety, respectively, after correction for demographic and injury-related variables. During participants' first inpatient rehabilitation stay after SCI, body image progressed toward a healthier state. Body image explains part of the variance in depression and anxiety, and the entire rehabilitation team should be targeting interventions to improve body image. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Comparison of a flexible versus a rigid breast compression paddle: pain experience, projected breast area, radiation dose and technical image quality.

PubMed

Broeders, Mireille J M; Ten Voorde, Marloes; Veldkamp, Wouter J H; van Engen, Ruben E; van Landsveld-Verhoeven, Cary; 't Jong-Gunneman, Machteld N L; de Win, Jos; Greve, Kitty Droogh-de; Paap, Ellen; den Heeten, Gerard J

2015-03-01

To compare pain, projected breast area, radiation dose and image quality between flexible (FP) and rigid (RP) breast compression paddles. The study was conducted in a Dutch mammographic screening unit (288 women). To compare both paddles one additional image with RP was made, consisting of either a mediolateral-oblique (MLO) or craniocaudal-view (CC). Pain experience was scored using the Numeric Rating Scale (NRS). Projected breast area was estimated using computer software. Radiation dose was estimated using the model by Dance. Image quality was reviewed by three radiologists and three radiographers. There was no difference in pain experience between both paddles (mean difference NRS: 0.08 ± 0.08, p = 0.32). Mean radiation dose was 4.5 % lower with FP (0.09 ± 0.01 p = 0.00). On MLO-images, the projected breast area was 0.79 % larger with FP. Paired evaluation of image quality indicated that FP removed fibroglandular tissue from the image area and reduced contrast in the clinically relevant retroglandular area at chest wall side. Although FP performed slightly better in the projected breast area, it moved breast tissue from the image area at chest wall side. RP showed better contrast, especially in the retroglandular area. We therefore recommend the use of RP for standard MLO and CC views.

Experimental study of an off-axis three mirror anastigmatic system with wavefront coding technology.

PubMed

Yan, Feng; Tao, Xiaoping

2012-04-10

Wavefront coding (WFC) is a kind of computational imaging technique that controls defocus and defocus related aberrations of optical systems by introducing a specially designed phase distribution to the pupil function. This technology has been applied in many imaging systems to improve performance and/or reduce cost. The application of WFC technology in an off-axis three mirror anastigmatic (TMA) system has been proposed, and the design and optimization of optics, the restoration of degraded images, and the manufacturing of wavefront coded elements have been researched in our previous work. In this paper, we describe the alignment, the imaging experiment, and the image restoration of the off-axis TMA system with WFC technology. The ideal wavefront map is set to be the system error of the interferometer to simplify the assembly, and the coefficients of certain Zernike polynomials are monitored to verify the result in the alignment process. A pinhole of 20 μm diameter and the third plate of WT1005-62 resolution patterns are selected as the targets in the imaging experiment. The comparison of the tail lengths of point spread functions is represented to show the invariance of the image quality in the extended depth of focus. The structure similarity is applied to estimate the relationship among the captured images with varying defocus. We conclude that the experiment results agree with the earlier theoretical analysis.

Differential standard deviation of log-scale intensity based optical coherence tomography angiography.

PubMed

Shi, Weisong; Gao, Wanrong; Chen, Chaoliang; Yang, Victor X D

2017-12-01

In this paper, a differential standard deviation of log-scale intensity (DSDLI) based optical coherence tomography angiography (OCTA) is presented for calculating microvascular images of human skin. The DSDLI algorithm calculates the variance in difference images of two consecutive log-scale intensity based structural images from the same position along depth direction to contrast blood flow. The en face microvascular images were then generated by calculating the standard deviation of the differential log-scale intensities within the specific depth range, resulting in an improvement in spatial resolution and SNR in microvascular images compared to speckle variance OCT and power intensity differential method. The performance of DSDLI was testified by both phantom and in vivo experiments. In in vivo experiments, a self-adaptive sub-pixel image registration algorithm was performed to remove the bulk motion noise, where 2D Fourier transform was utilized to generate new images with spatial interval equal to half of the distance between two pixels in both fast-scanning and depth directions. The SNRs of signals of flowing particles are improved by 7.3 dB and 6.8 dB on average in phantom and in vivo experiments, respectively, while the average spatial resolution of images of in vivo blood vessels is increased by 21%. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Joint Spatial-Spectral Reconstruction and k-t Spirals for Accelerated 2D Spatial/1D Spectral Imaging of 13C Dynamics

PubMed Central

Gordon, Jeremy W.; Niles, David J.; Fain, Sean B.; Johnson, Kevin M.

2014-01-01

Purpose To develop a novel imaging technique to reduce the number of excitations and required scan time for hyperpolarized 13C imaging. Methods A least-squares based optimization and reconstruction is developed to simultaneously solve for both spatial and spectral encoding. By jointly solving both domains, spectral imaging can potentially be performed with a spatially oversampled single echo spiral acquisition. Digital simulations, phantom experiments, and initial in vivo hyperpolarized [1-13C]pyruvate experiments were performed to assess the performance of the algorithm as compared to a multi-echo approach. Results Simulations and phantom data indicate that accurate single echo imaging is possible when coupled with oversampling factors greater than six (corresponding to a worst case of pyruvate to metabolite ratio < 9%), even in situations of substantial T2* decay and B0 heterogeneity. With lower oversampling rates, two echoes are required for similar accuracy. These results were confirmed with in vivo data experiments, showing accurate single echo spectral imaging with an oversampling factor of 7 and two echo imaging with an oversampling factor of 4. Conclusion The proposed k-t approach increases data acquisition efficiency by reducing the number of echoes required to generate spectroscopic images, thereby allowing accelerated acquisition speed, preserved polarization, and/or improved temporal or spatial resolution. Magn Reson Med PMID:23716402

Sociocultural experiences, body image, and indoor tanning among young adult women.

PubMed

Stapleton, Jerod L; Manne, Sharon L; Greene, Kathryn; Darabos, Katie; Carpenter, Amanda; Hudson, Shawna V; Coups, Elliot J

2017-10-01

The purpose of this survey study was to evaluate a model of body image influences on indoor tanning behavior. Participants were 823 young adult women recruited from a probability-based web panel in the United States. Consistent with our hypothesized model, tanning-related sociocultural experiences were indirectly associated with lifetime indoor tanning use and intentions to tan as mediated through tan surveillance and tan dissatisfaction. Findings suggest the need for targeting body image constructs as mechanisms of behavior change in indoor tanning behavioral interventions.

Mechanisms of Radiation-Induced Bone Loss and Effect on Prostate Cancer Bone Metastases

DTIC Science & Technology

2012-06-01

Develop intravital multiphoton fluorescence microscopy (IVFM) for real-time imaging of osteocytes in calvariae of transgenic mice using i) GFP to...OT, OB counting) and in vivo bone imaging (months 6-10) 8 20 week old female C57Bl/6 mice (n=30) were used in this experiment. The mice were...divided into 2 groups. One group (group A, n=15) was imaged twice by microCT during the experiment that included a baseline microCT that was given 2 days

Chemistry Graduate Teaching Assistants' Experiences in Academic Laboratories and Development of a Teaching Self-image

NASA Astrophysics Data System (ADS)

Gatlin, Todd Adam

Graduate teaching assistants (GTAs) play a prominent role in chemistry laboratory instruction at research based universities. They teach almost all undergraduate chemistry laboratory courses. However, their role in laboratory instruction has often been overlooked in educational research. Interest in chemistry GTAs has been placed on training and their perceived expectations, but less attention has been paid to their experiences or their potential benefits from teaching. This work was designed to investigate GTAs' experiences in and benefits from laboratory instructional environments. This dissertation includes three related studies on GTAs' experiences teaching in general chemistry laboratories. Qualitative methods were used for each study. First, phenomenological analysis was used to explore GTAs' experiences in an expository laboratory program. Post-teaching interviews were the primary data source. GTAs experiences were described in three dimensions: doing, knowing, and transferring. Gains available to GTAs revolved around general teaching skills. However, no gains specifically related to scientific development were found in this laboratory format. Case-study methods were used to explore and illustrate ways GTAs develop a GTA self-image---the way they see themselves as instructors. Two general chemistry laboratory programs that represent two very different instructional frameworks were chosen for the context of this study. The first program used a cooperative project-based approach. The second program used weekly, verification-type activities. End of the semester interviews were collected and served as the primary data source. A follow-up case study of a new cohort of GTAs in the cooperative problem-based laboratory was undertaken to investigate changes in GTAs' self-images over the course of one semester. Pre-semester and post-semester interviews served as the primary data source. Findings suggest that GTAs' construction of their self-image is shaped through the interaction of 1) prior experiences, 2) training, 3) beliefs about the nature of knowledge, 4) beliefs about the nature of laboratory work, and 5) involvement in the laboratory setting. Further GTAs' self-images are malleable and susceptible to change through their laboratory teaching experiences. Overall, this dissertation contributes to chemistry education by providing a model useful for exploring GTAs' development of a self-image in laboratory teaching. This work may assist laboratory instructors and coordinators in reconsidering, when applicable, GTA training and support. This work also holds considerable implications for how teaching experiences are conceptualized as part of the chemistry graduate education experience. Findings suggest that appropriate teaching experiences may contribute towards better preparing graduate students for their journey in becoming scientists.

Embodied memory allows accurate and stable perception of hidden objects despite orientation change.

PubMed

Pan, Jing Samantha; Bingham, Ned; Bingham, Geoffrey P

2017-07-01

Rotating a scene in a frontoparallel plane (rolling) yields a change in orientation of constituent images. When using only information provided by static images to perceive a scene after orientation change, identification performance typically decreases (Rock & Heimer, 1957). However, rolling generates optic flow information that relates the discrete, static images (before and after the change) and forms an embodied memory that aids recognition. The embodied memory hypothesis predicts that upon detecting a continuous spatial transformation of image structure, or in other words, seeing the continuous rolling process and objects undergoing rolling observers should accurately perceive objects during and after motion. Thus, in this case, orientation change should not affect performance. We tested this hypothesis in three experiments and found that (a) using combined optic flow and image structure, participants identified locations of previously perceived but currently occluded targets with great accuracy and stability (Experiment 1); (b) using combined optic flow and image structure information, participants identified hidden targets equally well with or without 30° orientation changes (Experiment 2); and (c) when the rolling was unseen, identification of hidden targets after orientation change became worse (Experiment 3). Furthermore, when rolling was unseen, although target identification was better when participants were told about the orientation change than when they were not told, performance was still worse than when there was no orientation change. Therefore, combined optic flow and image structure information, not mere knowledge about the rolling, enables accurate and stable perception despite orientation change. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

High resolution imaging science experiment (HiRISE) images of volcanic terrains from the first 6 months of the Mars reconnaissance orbiter primary science phase

USGS Publications Warehouse

Keszthelyi, L.; Jaeger, W.; McEwen, A.; Tornabene, L.; Beyer, R.A.; Dundas, C.; Milazzo, M.

2008-01-01

In the first 6 months of the Mars Reconnaissance Orbiter's Primary Science Phase, the High Resolution Imaging Science Experiment (HiRISE) camera has returned images sampling the diversity of volcanic terrains on Mars. While many of these features were noted in earlier imaging, they are now seen with unprecedented clarity. We find that some volcanic vents produced predominantly effusive products while others generated mostly pyroclastics. Flood lavas were emplaced in both turbulent and gentle eruptions, producing roofed channels and inflation features. However, many areas on Mars are too heavily mantled to allow meter-scale volcanic features to be discerned. In particular, the major volcanic edifices are extensively mantled, though it is possible that some of the mantle is pyroclastic material rather than atmospheric dust. Support imaging by the Context Imager (CTX) and topographic information derived from stereo imaging are both invaluable in interpreting the HiRISE data. Copyright 2008 by the American Geophysical Union.

[An improved low spectral distortion PCA fusion method].

PubMed

Peng, Shi; Zhang, Ai-Wu; Li, Han-Lun; Hu, Shao-Xing; Meng, Xian-Gang; Sun, Wei-Dong

2013-10-01

Aiming at the spectral distortion produced in PCA fusion process, the present paper proposes an improved low spectral distortion PCA fusion method. This method uses NCUT (normalized cut) image segmentation algorithm to make a complex hyperspectral remote sensing image into multiple sub-images for increasing the separability of samples, which can weaken the spectral distortions of traditional PCA fusion; Pixels similarity weighting matrix and masks were produced by using graph theory and clustering theory. These masks are used to cut the hyperspectral image and high-resolution image into some sub-region objects. All corresponding sub-region objects between the hyperspectral image and high-resolution image are fused by using PCA method, and all sub-regional integration results are spliced together to produce a new image. In the experiment, Hyperion hyperspectral data and Rapid Eye data were used. And the experiment result shows that the proposed method has the same ability to enhance spatial resolution and greater ability to improve spectral fidelity performance.

Perspective: Advanced particle imaging

PubMed Central

Chandler, David W.

2017-01-01

Since the first ion imaging experiment [D. W. Chandler and P. L. Houston, J. Chem. Phys. 87, 1445–1447 (1987)], demonstrating the capability of collecting an image of the photofragments from a unimolecular dissociation event and analyzing that image to obtain the three-dimensional velocity distribution of the fragments, the efficacy and breadth of application of the ion imaging technique have continued to improve and grow. With the addition of velocity mapping, ion/electron centroiding, and slice imaging techniques, the versatility and velocity resolution have been unmatched. Recent improvements in molecular beam, laser, sensor, and computer technology are allowing even more advanced particle imaging experiments, and eventually we can expect multi-mass imaging with co-variance and full coincidence capability on a single shot basis with repetition rates in the kilohertz range. This progress should further enable “complete” experiments—the holy grail of molecular dynamics—where all quantum numbers of reactants and products of a bimolecular scattering event are fully determined and even under our control. PMID:28688442

Are there age differences in attention to emotional images following a sad mood induction? Evidence from a free-viewing eye-tracking paradigm.

PubMed

Speirs, Calandra; Belchev, Zorry; Fernandez, Amanda; Korol, Stephanie; Sears, Christopher

2017-10-30

Two experiments examined age differences in the effect of a sad mood induction (MI) on attention to emotional images. Younger and older adults viewed sets of four images while their eye gaze was tracked throughout an 8-s presentation. Images were viewed before and after a sad MI to assess the effect of a sad mood on attention to positive and negative scenes. Younger and older adults exhibited positively biased attention after the sad MI, significantly increasing their attention to positive images, with no evidence of an age difference in either experiment. A test of participants' recognition memory for the images indicated that the sad MI reduced memory accuracy for sad images for younger and older adults. The results suggest that heightened attention to positive images following a sad MI reflects an affect regulation strategy related to mood repair. The implications for theories of the positivity effect are discussed.

Temperature, Pressure, and Infrared Image Survey of an Axisymmetric Heated Exhaust Plume

NASA Technical Reports Server (NTRS)

Nelson, Edward L.; Mahan, J. Robert; Birckelbaw, Larry D.; Turk, Jeffrey A.; Wardwell, Douglas A.; Hange, Craig E.

1996-01-01

The focus of this research is to numerically predict an infrared image of a jet engine exhaust plume, given field variables such as temperature, pressure, and exhaust plume constituents as a function of spatial position within the plume, and to compare this predicted image directly with measured data. This work is motivated by the need to validate computational fluid dynamic (CFD) codes through infrared imaging. The technique of reducing the three-dimensional field variable domain to a two-dimensional infrared image invokes the use of an inverse Monte Carlo ray trace algorithm and an infrared band model for exhaust gases. This report describes an experiment in which the above-mentioned field variables were carefully measured. Results from this experiment, namely tables of measured temperature and pressure data, as well as measured infrared images, are given. The inverse Monte Carlo ray trace technique is described. Finally, experimentally obtained infrared images are directly compared to infrared images predicted from the measured field variables.

Experimenting liver fibrosis diagnostic by two photon excitation microscopy and Bag-of-Features image classification.

PubMed

Stanciu, Stefan G; Xu, Shuoyu; Peng, Qiwen; Yan, Jie; Stanciu, George A; Welsch, Roy E; So, Peter T C; Csucs, Gabor; Yu, Hanry

2014-04-10

The accurate staging of liver fibrosis is of paramount importance to determine the state of disease progression, therapy responses, and to optimize disease treatment strategies. Non-linear optical microscopy techniques such as two-photon excitation fluorescence (TPEF) and second harmonic generation (SHG) can image the endogenous signals of tissue structures and can be used for fibrosis assessment on non-stained tissue samples. While image analysis of collagen in SHG images was consistently addressed until now, cellular and tissue information included in TPEF images, such as inflammatory and hepatic cell damage, equally important as collagen deposition imaged by SHG, remain poorly exploited to date. We address this situation by experimenting liver fibrosis quantification and scoring using a combined approach based on TPEF liver surface imaging on a Thioacetamide-induced rat model and a gradient based Bag-of-Features (BoF) image classification strategy. We report the assessed performance results and discuss the influence of specific BoF parameters to the performance of the fibrosis scoring framework.

Experimenting Liver Fibrosis Diagnostic by Two Photon Excitation Microscopy and Bag-of-Features Image Classification

PubMed Central

Stanciu, Stefan G.; Xu, Shuoyu; Peng, Qiwen; Yan, Jie; Stanciu, George A.; Welsch, Roy E.; So, Peter T. C.; Csucs, Gabor; Yu, Hanry

2014-01-01

The accurate staging of liver fibrosis is of paramount importance to determine the state of disease progression, therapy responses, and to optimize disease treatment strategies. Non-linear optical microscopy techniques such as two-photon excitation fluorescence (TPEF) and second harmonic generation (SHG) can image the endogenous signals of tissue structures and can be used for fibrosis assessment on non-stained tissue samples. While image analysis of collagen in SHG images was consistently addressed until now, cellular and tissue information included in TPEF images, such as inflammatory and hepatic cell damage, equally important as collagen deposition imaged by SHG, remain poorly exploited to date. We address this situation by experimenting liver fibrosis quantification and scoring using a combined approach based on TPEF liver surface imaging on a Thioacetamide-induced rat model and a gradient based Bag-of-Features (BoF) image classification strategy. We report the assessed performance results and discuss the influence of specific BoF parameters to the performance of the fibrosis scoring framework. PMID:24717650

Experimenting Liver Fibrosis Diagnostic by Two Photon Excitation Microscopy and Bag-of-Features Image Classification

NASA Astrophysics Data System (ADS)

Stanciu, Stefan G.; Xu, Shuoyu; Peng, Qiwen; Yan, Jie; Stanciu, George A.; Welsch, Roy E.; So, Peter T. C.; Csucs, Gabor; Yu, Hanry

2014-04-01

The accurate staging of liver fibrosis is of paramount importance to determine the state of disease progression, therapy responses, and to optimize disease treatment strategies. Non-linear optical microscopy techniques such as two-photon excitation fluorescence (TPEF) and second harmonic generation (SHG) can image the endogenous signals of tissue structures and can be used for fibrosis assessment on non-stained tissue samples. While image analysis of collagen in SHG images was consistently addressed until now, cellular and tissue information included in TPEF images, such as inflammatory and hepatic cell damage, equally important as collagen deposition imaged by SHG, remain poorly exploited to date. We address this situation by experimenting liver fibrosis quantification and scoring using a combined approach based on TPEF liver surface imaging on a Thioacetamide-induced rat model and a gradient based Bag-of-Features (BoF) image classification strategy. We report the assessed performance results and discuss the influence of specific BoF parameters to the performance of the fibrosis scoring framework.

Whole Slide Images and Digital Media in Pathology Education, Testing, and Practice: The Oklahoma Experience

PubMed Central

Fung, Kar-Ming; Hassell, Lewis A.; Talbert, Michael L.; Wiechmann, Allan F.; Chaser, Brad E.; Ramey, Joel

2012-01-01

Examination of glass slides is of paramount importance in pathology training. Until the introduction of digitized whole slide images that could be accessed through computer networks, the sharing of pathology slides was a major logistic issue in pathology education and practice. With the help of whole slide images, our department has developed several online pathology education websites. Based on a modular architecture, this program provides online access to whole slide images, still images, case studies, quizzes and didactic text at different levels. Together with traditional lectures and hands-on experiences, it forms the back bone of our histology and pathology education system for residents and medical students. The use of digitized whole slide images has a.lso greatly improved the communication between clinicians and pathologist in our institute. PMID:21965282

Simultaneous usage of pinhole and penumbral apertures for imaging small scale neutron sources from inertial confinement fusion experiments.

PubMed

Guler, N; Volegov, P; Danly, C R; Grim, G P; Merrill, F E; Wilde, C H

2012-10-01

Inertial confinement fusion experiments at the National Ignition Facility are designed to understand the basic principles of creating self-sustaining fusion reactions by laser driven compression of deuterium-tritium (DT) filled cryogenic plastic capsules. The neutron imaging diagnostic provides information on the distribution of the central fusion reaction region and the surrounding DT fuel by observing neutron images in two different energy bands for primary (13-17 MeV) and down-scattered (6-12 MeV) neutrons. From this, the final shape and size of the compressed capsule can be estimated and the symmetry of the compression can be inferred. These experiments provide small sources with high yield neutron flux. An aperture design that includes an array of pinholes and penumbral apertures has provided the opportunity to image the same source with two different techniques. This allows for an evaluation of these different aperture designs and reconstruction algorithms.

Flexible sample environment for high resolution neutron imaging at high temperatures in controlled atmosphere

DOE Office of Scientific and Technical Information (OSTI.GOV)

Makowska, Małgorzata G.; Theil Kuhn, Luise; Cleemann, Lars N.

In high material penetration by neutrons allows for experiments using sophisticated sample environments providing complex conditions. Thus, neutron imaging holds potential for performing in situ nondestructive measurements on large samples or even full technological systems, which are not possible with any other technique. Our paper presents a new sample environment for in situ high resolution neutron imaging experiments at temperatures from room temperature up to 1100 degrees C and/or using controllable flow of reactive atmospheres. The design also offers the possibility to directly combine imaging with diffraction measurements. Design, special features, and specification of the furnace are described. In addition,more » examples of experiments successfully performed at various neutron facilities with the furnace, as well as examples of possible applications are presented. Our work covers a broad field of research from fundamental to technological investigations of various types of materials and components.« less

Flexible sample environment for high resolution neutron imaging at high temperatures in controlled atmosphere

DOE PAGES

Makowska, Małgorzata G.; Theil Kuhn, Luise; Cleemann, Lars N.; ...

2015-12-17

In high material penetration by neutrons allows for experiments using sophisticated sample environments providing complex conditions. Thus, neutron imaging holds potential for performing in situ nondestructive measurements on large samples or even full technological systems, which are not possible with any other technique. Our paper presents a new sample environment for in situ high resolution neutron imaging experiments at temperatures from room temperature up to 1100 degrees C and/or using controllable flow of reactive atmospheres. The design also offers the possibility to directly combine imaging with diffraction measurements. Design, special features, and specification of the furnace are described. In addition,more » examples of experiments successfully performed at various neutron facilities with the furnace, as well as examples of possible applications are presented. Our work covers a broad field of research from fundamental to technological investigations of various types of materials and components.« less

Virtual Reality: Bringing the Awe of Our Science into The Classroom with VR

NASA Astrophysics Data System (ADS)

Bell, R. E.; Turrin, M.; Frearson, N.; Boghosian, A.; Ferrini, V. L.; Simpson, F.

2016-12-01

The geosciences are rich in imagery, making them compelling material for immersive teaching experiences. We often work in remote locations, places where few others are able to travel. Flat 2 D images from the field have served explorers and scientists well from the lantern slides brought back from Antarctica to the images scientists and educators now use in powerpoint presentations. These images provide a backdrop to introduce the experience for formal classes and informal presentations. Our stories from the field bring the setting alive for the participants. The travelers presented and the audience passively listened. Immersive learning opportunities are much more powerful than lecturing. We have enlisted both VR and drone imagery to bring learners fully into the experience of science. A 360 VR image brings the viewer into the moment of discovery. Both have been shown to create an active learning setting fully under the learner's control; they explore at their own pace and following their own interest. This learning `sticks', becoming part of the participant's own unique experience in the space. We are building VR images of field experiences and VR data immersion experiences that will transport people into new locations, building a field experience that they can not only see but fully explore. Through VR we introduce new experiences that showcase our science, our careers and our collaborations. Users can spin the view up to see the helicopter landing in a remote field location by the ice. Spin to the right and see a colleague collecting a reading from instruments that have been pulled from the LC130 aircraft. Turn the view to the left and see the harsh windswept environment along the edge of an ice shelf. Look down and note that you feet are encased in snow boots to keep them warm and stable on the ice. The viewer is in the field as part of the science team. Learning in the classroom and through social media is now fully 360 and fully immersive.

Nighttime images fusion based on Laplacian pyramid

NASA Astrophysics Data System (ADS)

Wu, Cong; Zhan, Jinhao; Jin, Jicheng

2018-02-01

This paper expounds method of the average weighted fusion, image pyramid fusion, the wavelet transform and apply these methods on the fusion of multiple exposures nighttime images. Through calculating information entropy and cross entropy of fusion images, we can evaluate the effect of different fusion. Experiments showed that Laplacian pyramid image fusion algorithm is suitable for processing nighttime images fusion, it can reduce the halo while preserving image details.

Social Inferences from Faces: Ambient Images Generate a Three-Dimensional Model

ERIC Educational Resources Information Center

Sutherland, Clare A. M.; Oldmeadow, Julian A.; Santos, Isabel M.; Towler, John; Burt, D. Michael; Young, Andrew W.

2013-01-01

Three experiments are presented that investigate the two-dimensional valence/trustworthiness by dominance model of social inferences from faces (Oosterhof & Todorov, 2008). Experiment 1 used image averaging and morphing techniques to demonstrate that consistent facial cues subserve a range of social inferences, even in a highly variable sample of…

In-Situ Visualization Experiments with ParaView Cinema in RAGE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kares, Robert John

2015-10-15

A previous paper described some numerical experiments performed using the ParaView/Catalyst in-situ visualization infrastructure deployed in the Los Alamos RAGE radiation-hydrodynamics code to produce images from a running large scale 3D ICF simulation. One challenge of the in-situ approach apparent in these experiments was the difficulty of choosing parameters likes isosurface values for the visualizations to be produced from the running simulation without the benefit of prior knowledge of the simulation results and the resultant cost of recomputing in-situ generated images when parameters are chosen suboptimally. A proposed method of addressing this difficulty is to simply render multiple images atmore » runtime with a range of possible parameter values to produce a large database of images and to provide the user with a tool for managing the resulting database of imagery. Recently, ParaView/Catalyst has been extended to include such a capability via the so-called Cinema framework. Here I describe some initial experiments with the first delivery of Cinema and make some recommendations for future extensions of Cinema’s capabilities.« less

Quantitative imaging biomarker ontology (QIBO) for knowledge representation of biomedical imaging biomarkers.

PubMed

Buckler, Andrew J; Liu, Tiffany Ting; Savig, Erica; Suzek, Baris E; Ouellette, M; Danagoulian, J; Wernsing, G; Rubin, Daniel L; Paik, David

2013-08-01

A widening array of novel imaging biomarkers is being developed using ever more powerful clinical and preclinical imaging modalities. These biomarkers have demonstrated effectiveness in quantifying biological processes as they occur in vivo and in the early prediction of therapeutic outcomes. However, quantitative imaging biomarker data and knowledge are not standardized, representing a critical barrier to accumulating medical knowledge based on quantitative imaging data. We use an ontology to represent, integrate, and harmonize heterogeneous knowledge across the domain of imaging biomarkers. This advances the goal of developing applications to (1) improve precision and recall of storage and retrieval of quantitative imaging-related data using standardized terminology; (2) streamline the discovery and development of novel imaging biomarkers by normalizing knowledge across heterogeneous resources; (3) effectively annotate imaging experiments thus aiding comprehension, re-use, and reproducibility; and (4) provide validation frameworks through rigorous specification as a basis for testable hypotheses and compliance tests. We have developed the Quantitative Imaging Biomarker Ontology (QIBO), which currently consists of 488 terms spanning the following upper classes: experimental subject, biological intervention, imaging agent, imaging instrument, image post-processing algorithm, biological target, indicated biology, and biomarker application. We have demonstrated that QIBO can be used to annotate imaging experiments with standardized terms in the ontology and to generate hypotheses for novel imaging biomarker-disease associations. Our results established the utility of QIBO in enabling integrated analysis of quantitative imaging data.

Simulations, Imaging, and Modeling: A Unique Theme for an Undergraduate Research Program in Biomechanics.

PubMed

George, Stephanie M; Domire, Zachary J

2017-07-01

As the reliance on computational models to inform experiments and evaluate medical devices grows, the demand for students with modeling experience will grow. In this paper, we report on the 3-yr experience of a National Science Foundation (NSF) funded Research Experiences for Undergraduates (REU) based on the theme simulations, imaging, and modeling in biomechanics. While directly applicable to REU sites, our findings also apply to those creating other types of summer undergraduate research programs. The objective of the paper is to examine if a theme of simulations, imaging, and modeling will improve students' understanding of the important topic of modeling, provide an overall positive research experience, and provide an interdisciplinary experience. The structure of the program and the evaluation plan are described. We report on the results from 25 students over three summers from 2014 to 2016. Overall, students reported significant gains in the knowledge of modeling, research process, and graduate school based on self-reported mastery levels and open-ended qualitative responses. This theme provides students with a skill set that is adaptable to other applications illustrating the interdisciplinary nature of modeling in biomechanics. Another advantage is that students may also be able to continue working on their project following the summer experience through network connections. In conclusion, we have described the successful implementation of the theme simulation, imaging, and modeling for an REU site and the overall positive response of the student participants.

Midcourse Space Experiment Data Certification and Technology Transfer. Supplement 1

NASA Technical Reports Server (NTRS)

Pollock, David B.

1998-01-01

The University of Alabama in Huntsville contributes to the Technical Management of the Midcourse Space Experiment Program, to the Certification of the Level 2 data produced by the Midcourse Space Experiment's suite of in-orbit imaging radiometers, imaging spectro-radiometers and an interferometer and to the Transfer of the Midcourse Space Experiment Technology to other Government Programs. The Technical Management of the Midcourse Space Experiment Program is expected to continue through out the spacecraft's useful life time. The Transfer of Midcourse Space Experiment Technology to other government elements is expected to be on a demand basis by the United States Government and other organizations. The University, of Alabama Huntsville' contribution specifically supports the Principal Investigator's Executive Committee, the Deputy Principal Investigator for Data Certification and Technology Transfer team, the nine Ultraviolet Visible Imagers and Spectrographic Imagers (UVISI) and the Pointing and Alignment of all eleven of the science instruments. The science instruments effectively cover the 0.1 to 28 micron spectral region. The Midcourse Space Experiment spacecraft, launched April 24, 1996, is expected to have a 5 year useful lifetime. The cryogenically cooled IR sensor, SPIRIT III, performed through February, 1997 when its cryogen expired. A pre-launch, ground based calibration of the instruments provided a basis for the pre-launch certification of the Level 2 data base these instruments produce. With the spacecraft in-orbit the certification of the instrument's Level 2 data base was extended to the in-orbit environment.

Disgust Enhances the Recollection of Negative Emotional Images

PubMed Central

Croucher, Camilla J.; Calder, Andrew J.; Ramponi, Cristina; Barnard, Philip J.; Murphy, Fionnuala C.

2011-01-01

Memory is typically better for emotional relative to neutral images, an effect generally considered to be mediated by arousal. However, this explanation cannot explain the full pattern of findings in the literature. Two experiments are reported that investigate the differential effects of categorical affective states upon emotional memory and the contributions of stimulus dimensions other than pleasantness and arousal to any memory advantage. In Experiment 1, disgusting images were better remembered than equally unpleasant frightening ones, despite the disgusting images being less arousing. In Experiment 2, regression analyses identified affective impact – a factor shown previously to influence the allocation of visual attention and amygdala response to negative emotional images – as the strongest predictor of remembering. These findings raise significant issues that the arousal account of emotional memory cannot readily address. The term impact refers to an undifferentiated emotional response to a stimulus, without requiring detailed consideration of specific dimensions of image content. We argue that ratings of impact relate to how the self is affected. The present data call for further consideration of the theoretical specifications of the mechanisms that lead to enhanced memory for emotional stimuli and their neural substrates. PMID:22110588

Determining biosonar images using sparse representations.

PubMed

Fontaine, Bertrand; Peremans, Herbert

2009-05-01

Echolocating bats are thought to be able to create an image of their environment by emitting pulses and analyzing the reflected echoes. In this paper, the theory of sparse representations and its more recent further development into compressed sensing are applied to this biosonar image formation task. Considering the target image representation as sparse allows formulation of this inverse problem as a convex optimization problem for which well defined and efficient solution methods have been established. The resulting technique, referred to as L1-minimization, is applied to simulated data to analyze its performance relative to delay accuracy and delay resolution experiments. This method performs comparably to the coherent receiver for the delay accuracy experiments, is quite robust to noise, and can reconstruct complex target impulse responses as generated by many closely spaced reflectors with different reflection strengths. This same technique, in addition to reconstructing biosonar target images, can be used to simultaneously localize these complex targets by interpreting location cues induced by the bat's head related transfer function. Finally, a tentative explanation is proposed for specific bat behavioral experiments in terms of the properties of target images as reconstructed by the L1-minimization method.

Desensitizing Addiction: Using Eye Movements to Reduce the Intensity of Substance-Related Mental Imagery and Craving.

PubMed

Littel, Marianne; van den Hout, Marcel A; Engelhard, Iris M

2016-01-01

Eye movement desensitization and reprocessing (EMDR) is an effective treatment for posttraumatic stress disorder. During this treatment, patients recall traumatic memories while making horizontal eye movements (EM). Studies have shown that EM not only desensitize negative memories but also positive memories and imagined events. Substance use behavior and craving are maintained by maladaptive memory associations and visual imagery. Preliminary findings have indicated that these mental images can be desensitized by EMDR techniques. We conducted two proof-of-principle studies to investigate whether EM can reduce the sensory richness of substance-related mental representations and accompanying craving levels. We investigated the effects of EM on (1) vividness of food-related mental imagery and food craving in dieting and non-dieting students and (2) vividness of recent smoking-related memories and cigarette craving in daily smokers. In both experiments, participants recalled the images while making EM or keeping eyes stationary. Image vividness and emotionality, image-specific craving and general craving were measured before and after the intervention. As a behavioral outcome measure, participants in study 1 were offered a snack choice at the end of the experiment. Results of both experiments showed that image vividness and craving increased in the control condition but remained stable or decreased after the EM intervention. EM additionally reduced image emotionality (experiment 2) and affected behavior (experiment 1): participants in the EM condition were more inclined to choose healthy over unhealthy snack options. In conclusion, these data suggest that EM can be used to reduce intensity of substance-related imagery and craving. Although long-term effects are yet to be demonstrated, the current studies suggest that EM might be a useful technique in addiction treatment.

Variable-Speed Instrumented Centrifuges

NASA Technical Reports Server (NTRS)

Chapman, David K.; Brown, Allan H.

1991-01-01

Report describes conceptual pair of centrifuges, speed of which varied to produce range of artificial gravities in zero-gravity environment. Image and data recording and controlled temperature and gravity provided for 12 experiments. Microprocessor-controlled centrifuges include video cameras to record stop-motion images of experiments. Potential applications include studies of effect of gravity on growth and on production of hormones in corn seedlings, experiments with magnetic flotation to separate cells, and electrophoresis to separate large fragments of deoxyribonucleic acid.

(DURIP 10) High Speed Intensified Imaging System For Studies Of Mixing And Combustion In Supersonic Flows And Hydrocarbon Flame Structure Measurements At Elevated Pressures

DTIC Science & Technology

2016-11-09

software, and their networking to augment optical diagnostics employed in supersonic reacting and non-reacting flow experiments . A high-speed...facility at Caltech. Experiments to date have made use of this equipment, extending previous capabilities to high-speed schlieren quantitative flow...visualization and image correlation velocimetry, with further experiments currently in progress. 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17

Learning the names of people: the role of image mediators.

PubMed

Groninger, L D; Groninger, D H; Stiens, J

1995-06-01

Four experiments are reported involving the effects of bizarre and common imagery mediation techniques on the learning and 1-week retention of surnames, given videotaped faces as cues. The videotapes contained 24 undergraduates who were photographed from about the chest up, and who introduced themselves at a 20-second rate. Experiment 1 showed that for both concrete and abstract names, immediate recall of the list was better under imagery mediation instructions than under control instructions. Experiment 2 studied the same conditions using immediate recognition memory of the list as a retrieval measure for the names, and found, despite ceiling effects, that bizarre imagery instructions facilitated recognition for concrete names. Experiment 3 showed that immediate recall could be improved if subjects were given an image mediator for every face-name pair as opposed to generating their own image mediators. Experiment 4 yielded three important findings: (a) 84% of the variance in the 1-week retention of initially recalled names was explained by the presence of absence of the original mediator during 1-week recall; (b) instructions to form image mediators facilitate recall not because image mediators are more effective than other types of mediators, but because they increase the likelihood that a mediator will be formed; (c) 1-week retention could be enhanced with an increased focus during encoding on the points where the mediation process is most likely to fail. The results of these studies are discussed within the context of mediation model wherein recall can fail at any of four stages.

Usage of CT data in biomechanical research

NASA Astrophysics Data System (ADS)

Safonov, Roman A.; Golyadkina, Anastasiya A.; Kirillova, Irina V.; Kossovich, Leonid Y.

2017-02-01

Object of study: The investigation is focused on development of personalized medicine. The determination of mechanical properties of bone tissues based on in vivo data was considered. Methods: CT, MRI, natural experiments on versatile test machine Instron 5944, numerical experiments using Python programs. Results: The medical diagnostics methods, which allows determination of mechanical properties of bone tissues based on in vivo data. The series of experiments to define the values of mechanical parameters of bone tissues. For one and the same sample, computed tomography (CT), magnetic resonance imaging (MRI), ultrasonic investigations and mechanical experiments on single-column test machine Instron 5944 were carried out. The computer program for comparison of CT and MRI images was created. The grayscale values in the same points of the samples were determined on both CT and MRI images. The Haunsfield grayscale values were used to determine rigidity (Young module) and tensile strength of the samples. The obtained data was compared to natural experiments results for verification.

Color Image of Phoenix Lander on Mars Surface

NASA Image and Video Library

2008-05-27

This is an enhanced-color image from Mars Reconnaissance Orbiter High Resolution Imaging Science Experiment HiRISE camera. It shows the NASA Mars Phoenix lander with its solar panels deployed on the Mars surface

Experience with Delay-Tolerant Networking from Orbit

NASA Technical Reports Server (NTRS)

Ivancic, W.; Eddy, W. M.; Stewart, D.; Wood, L.; Northam, J.; Jackson, C.

2010-01-01

We describe the first use from space of the Bundle Protocol for Delay-Tolerant Networking (DTN) and lessons learned from experiments made and experience gained with this protocol. The Disaster Monitoring Constellation (DMC), constructed by Surrey Satellite Technology Ltd (SSTL), is a multiple-satellite Earth-imaging low-Earth-orbit sensor network in which recorded image swaths are stored onboard each satellite and later downloaded from the satellite payloads to a ground station. Store-and-forward of images with capture and later download gives each satellite the characteristics of a node in a disruption-tolerant network. Originally developed for the Interplanetary Internet, DTNs are now under investigation in an Internet Research Task Force (IRTF) DTN research group (RG), which has developed a bundle architecture and protocol. The DMC is technically advanced in its adoption of the Internet Protocol (IP) for its imaging payloads and for satellite command and control, based around reuse of commercial networking and link protocols. These satellites use of IP has enabled earlier experiments with the Cisco router in Low Earth Orbit (CLEO) onboard the constellation s UK-DMC satellite. Earth images are downloaded from the satellites using a custom IP-based high-speed transfer protocol developed by SSTL, Saratoga, which tolerates unusual link environments. Saratoga has been documented in the Internet Engineering Task Force (IETF) for wider adoption. We experiment with the use of DTNRG bundle concepts onboard the UK-DMC satellite, by examining how Saratoga can be used as a DTN convergence layer to carry the DTNRG Bundle Protocol, so that sensor images can be delivered to ground stations and beyond as bundles. Our practical experience with the first successful use of the DTNRG Bundle Protocol in a space environment gives us insights into the design of the Bundle Protocol and enables us to identify issues that must be addressed before wider deployment of the Bundle Protocol. Published in 2010 by John Wiley & Sons, Ltd. KEY WORDS: Internet; UK-DMC; satellite; Delay-Tolerant Networking (DTN); Bundle Protocol

Idioms and mental imagery: the metaphorical motivation for idiomatic meaning.

PubMed

Gibbs, R W; O'Brien, J E

1990-07-01

We conducted three experiments to investigate the mental images associated with idiomatic phrases in English. Our hypothesis was that people should have strong conventional images for many idioms and that the regularity in people's knowledge of their images for idioms is due to the conceptual metaphors motivating the figurative meanings of idioms. In the first study, subjects were asked to form and describe their mental images for different idiomatic expressions. Subjects were then asked a series of detailed questions about their images regarding the causes and effects of different events within their images. We found high consistency in subjects' images of idioms with similar figurative meanings despite differences in their surface forms (e.g., spill the beans and let the cat out of the bag). Subjects' responses to detailed questions about their images also showed a high degree of similarity in their answers. Further examination of subjects' imagery protocols supports the idea that the conventional images and knowledge associated with idioms are constrained by the conceptual metaphors (e.g., the MIND IS A CONTAINER and IDEAS ARE ENTITIES) which motivate the figurative meanings of idioms. The results of two control studies showed that the conventional images associated with idioms are not solely based on their figurative meanings (Experiment 2) and that the images associated with literal phrases (e.g., spill the peas) were quite varied and unlikely to be constrained by conceptual metaphor (Experiment 3). These findings support the view that idioms are not "dead" metaphors with their meanings being arbitrarily determined. Rather, the meanings of many idioms are motivated by speakers' tacit knowledge of the conceptual metaphors underlying the meanings of these figurative phrases.

High-frame-rate digital radiographic videography

NASA Astrophysics Data System (ADS)

King, Nicholas S. P.; Cverna, Frank H.; Albright, Kevin L.; Jaramillo, Steven A.; Yates, George J.; McDonald, Thomas E.; Flynn, Michael J.; Tashman, Scott

1994-10-01

High speed x-ray imaging can be an important tool for observing internal processes in a wide range of applications. In this paper we describe preliminary implementation of a system having the eventual goal of observing the internal dynamics of bone and joint reactions during loading. Two Los Alamos National Laboratory (LANL) gated and image intensified camera systems were used to record images from an x-ray image convertor tube to demonstrate the potential of high frame-rate digital radiographic videography in the analysis of bone and joint dynamics of the human body. Preliminary experiments were done at LANL to test the systems. Initial high frame-rate imaging (from 500 to 1000 frames/s) of a swinging pendulum mounted to the face of an X-ray image convertor tube demonstrated high contrast response and baseline sensitivity. The systems were then evaluated at the Motion Analysis Laboratory of Henry Ford Health Systems Bone and Joint Center. Imaging of a 9 inch acrylic disk with embedded lead markers rotating at approximately 1000 RPM, demonstrated the system response to a high velocity/high contrast target. By gating the P-20 phosphor image from the X-ray image convertor with a second image intensifier (II) and using a 100 microsecond wide optical gate through the second II, enough prompt light decay from the x-ray image convertor phosphor had taken place to achieve reduction of most of the motion blurring. Measurement of the marker velocity was made by using video frames acquired at 500 frames/s. The data obtained from both experiments successfully demonstrated the feasibility of the technique. Several key areas for improvement are discussed along with salient test results and experiment details.

Rapid analysis and exploration of fluorescence microscopy images.

PubMed

Pavie, Benjamin; Rajaram, Satwik; Ouyang, Austin; Altschuler, Jason M; Steininger, Robert J; Wu, Lani F; Altschuler, Steven J

2014-03-19

Despite rapid advances in high-throughput microscopy, quantitative image-based assays still pose significant challenges. While a variety of specialized image analysis tools are available, most traditional image-analysis-based workflows have steep learning curves (for fine tuning of analysis parameters) and result in long turnaround times between imaging and analysis. In particular, cell segmentation, the process of identifying individual cells in an image, is a major bottleneck in this regard. Here we present an alternate, cell-segmentation-free workflow based on PhenoRipper, an open-source software platform designed for the rapid analysis and exploration of microscopy images. The pipeline presented here is optimized for immunofluorescence microscopy images of cell cultures and requires minimal user intervention. Within half an hour, PhenoRipper can analyze data from a typical 96-well experiment and generate image profiles. Users can then visually explore their data, perform quality control on their experiment, ensure response to perturbations and check reproducibility of replicates. This facilitates a rapid feedback cycle between analysis and experiment, which is crucial during assay optimization. This protocol is useful not just as a first pass analysis for quality control, but also may be used as an end-to-end solution, especially for screening. The workflow described here scales to large data sets such as those generated by high-throughput screens, and has been shown to group experimental conditions by phenotype accurately over a wide range of biological systems. The PhenoBrowser interface provides an intuitive framework to explore the phenotypic space and relate image properties to biological annotations. Taken together, the protocol described here will lower the barriers to adopting quantitative analysis of image based screens.

The effects of video compression on acceptability of images for monitoring life sciences experiments

NASA Astrophysics Data System (ADS)

Haines, Richard F.; Chuang, Sherry L.

1992-07-01

Future manned space operations for Space Station Freedom will call for a variety of carefully planned multimedia digital communications, including full-frame-rate color video, to support remote operations of scientific experiments. This paper presents the results of an investigation to determine if video compression is a viable solution to transmission bandwidth constraints. It reports on the impact of different levels of compression and associated calculational parameters on image acceptability to investigators in life-sciences research at ARC. Three nonhuman life-sciences disciplines (plant, rodent, and primate biology) were selected for this study. A total of 33 subjects viewed experimental scenes in their own scientific disciplines. Ten plant scientists viewed still images of wheat stalks at various stages of growth. Each image was compressed to four different compression levels using the Joint Photographic Expert Group (JPEG) standard algorithm, and the images were presented in random order. Twelve and eleven staffmembers viewed 30-sec videotaped segments showing small rodents and a small primate, respectively. Each segment was repeated at four different compression levels in random order using an inverse cosine transform (ICT) algorithm. Each viewer made a series of subjective image-quality ratings. There was a significant difference in image ratings according to the type of scene viewed within disciplines; thus, ratings were scene dependent. Image (still and motion) acceptability does, in fact, vary according to compression level. The JPEG still-image-compression levels, even with the large range of 5:1 to 120:1 in this study, yielded equally high levels of acceptability. In contrast, the ICT algorithm for motion compression yielded a sharp decline in acceptability below 768 kb/sec. Therefore, if video compression is to be used as a solution for overcoming transmission bandwidth constraints, the effective management of the ratio and compression parameters according to scientific discipline and experiment type is critical to the success of remote experiments.

The effects of video compression on acceptability of images for monitoring life sciences experiments

NASA Technical Reports Server (NTRS)

Haines, Richard F.; Chuang, Sherry L.

1992-01-01

Future manned space operations for Space Station Freedom will call for a variety of carefully planned multimedia digital communications, including full-frame-rate color video, to support remote operations of scientific experiments. This paper presents the results of an investigation to determine if video compression is a viable solution to transmission bandwidth constraints. It reports on the impact of different levels of compression and associated calculational parameters on image acceptability to investigators in life-sciences research at ARC. Three nonhuman life-sciences disciplines (plant, rodent, and primate biology) were selected for this study. A total of 33 subjects viewed experimental scenes in their own scientific disciplines. Ten plant scientists viewed still images of wheat stalks at various stages of growth. Each image was compressed to four different compression levels using the Joint Photographic Expert Group (JPEG) standard algorithm, and the images were presented in random order. Twelve and eleven staffmembers viewed 30-sec videotaped segments showing small rodents and a small primate, respectively. Each segment was repeated at four different compression levels in random order using an inverse cosine transform (ICT) algorithm. Each viewer made a series of subjective image-quality ratings. There was a significant difference in image ratings according to the type of scene viewed within disciplines; thus, ratings were scene dependent. Image (still and motion) acceptability does, in fact, vary according to compression level. The JPEG still-image-compression levels, even with the large range of 5:1 to 120:1 in this study, yielded equally high levels of acceptability. In contrast, the ICT algorithm for motion compression yielded a sharp decline in acceptability below 768 kb/sec. Therefore, if video compression is to be used as a solution for overcoming transmission bandwidth constraints, the effective management of the ratio and compression parameters according to scientific discipline and experiment type is critical to the success of remote experiments.

A content-based image retrieval method for optical colonoscopy images based on image recognition techniques

NASA Astrophysics Data System (ADS)

Nosato, Hirokazu; Sakanashi, Hidenori; Takahashi, Eiichi; Murakawa, Masahiro

2015-03-01

This paper proposes a content-based image retrieval method for optical colonoscopy images that can find images similar to ones being diagnosed. Optical colonoscopy is a method of direct observation for colons and rectums to diagnose bowel diseases. It is the most common procedure for screening, surveillance and treatment. However, diagnostic accuracy for intractable inflammatory bowel diseases, such as ulcerative colitis (UC), is highly dependent on the experience and knowledge of the medical doctor, because there is considerable variety in the appearances of colonic mucosa within inflammations with UC. In order to solve this issue, this paper proposes a content-based image retrieval method based on image recognition techniques. The proposed retrieval method can find similar images from a database of images diagnosed as UC, and can potentially furnish the medical records associated with the retrieved images to assist the UC diagnosis. Within the proposed method, color histogram features and higher order local auto-correlation (HLAC) features are adopted to represent the color information and geometrical information of optical colonoscopy images, respectively. Moreover, considering various characteristics of UC colonoscopy images, such as vascular patterns and the roughness of the colonic mucosa, we also propose an image enhancement method to highlight the appearances of colonic mucosa in UC. In an experiment using 161 UC images from 32 patients, we demonstrate that our method improves the accuracy of retrieving similar UC images.

Flexible reduced field of view magnetic resonance imaging based on single-shot spatiotemporally encoded technique

NASA Astrophysics Data System (ADS)

Li, Jing; Cai, Cong-Bo; Chen, Lin; Chen, Ying; Qu, Xiao-Bo; Cai, Shu-Hui

2015-10-01

In many ultrafast imaging applications, the reduced field-of-view (rFOV) technique is often used to enhance the spatial resolution and field inhomogeneity immunity of the images. The stationary-phase characteristic of the spatiotemporally-encoded (SPEN) method offers an inherent applicability to rFOV imaging. In this study, a flexible rFOV imaging method is presented and the superiority of the SPEN approach in rFOV imaging is demonstrated. The proposed method is validated with phantom and in vivo rat experiments, including cardiac imaging and contrast-enhanced perfusion imaging. For comparison, the echo planar imaging (EPI) experiments with orthogonal RF excitation are also performed. The results show that the signal-to-noise ratios of the images acquired by the proposed method can be higher than those obtained with the rFOV EPI. Moreover, the proposed method shows better performance in the cardiac imaging and perfusion imaging of rat kidney, and it can scan one or more regions of interest (ROIs) with high spatial resolution in a single shot. It might be a favorable solution to ultrafast imaging applications in cases with severe susceptibility heterogeneities, such as cardiac imaging and perfusion imaging. Furthermore, it might be promising in applications with separate ROIs, such as mammary and limb imaging. Project supported by the National Natural Science Foundation of China (Grant Nos. 11474236, 81171331, and U1232212).

A New 4D Imaging Method for Three-Phase Analogue Experiments in Volcanology (and Other Three-Phase Systems)

NASA Astrophysics Data System (ADS)

Oppenheimer, J.; Patel, K. B.; Lev, E.; Hillman, E. M. C.

2017-12-01

Bubbles and crystals suspended in magmas interact with each other on a small scale, which affects large-scale volcanic processes. Studying these interactions on relevant scales of time and space is a long-standing challenge. Therefore, the fundamental explanations for the behavior of bubble- and crystal-rich magmas are still largely speculative. Recent application of X-ray tomography to experiments with synthetic magmas has already improved our understanding of small-scale 4D (3D + time) phenomena. However, this technique has low imaging rates < 20 volumes per second (vps) and does not work well with analogues, making experiments costly and slow. We demonstrate a novel methodology for imaging bubble-particle interactions in analogue suspensions by utilizing Swept Confocally Aligned Planar Excitation (SCAPE) microscopy. This method based on laser-fluorescence has been used to image live biological processes at high speed and in 3D. It allows imaging rates of up to several hundred vps and image volumes up to 1 x 1 x 0.5 mm3, with a trade-off between speed and spatial resolution. We ran two sets of experiments with silicone oil and soda-lime glass beads of <50 µm diameter, contained within a vertical glass casing 50 x 5 x 4 mm3. We used two different bubble generation methods. In the first set of experiments, small air bubbles (< 1 mm) were introduced through a hole at the bottom of the sample and allowed to rise through a suspension with low-viscosity oil. We successfully imaged bubble rise and particle movements around the bubble. In the second set, bubbles were generated by mixing acetone into the suspension and decreasing the surface pressure to cause a phase change to gaseous acetone. This bubble generation method compared favorably with previous gum rosin-acetone experiments: they provided similar degassing behaviors, along with more control on suspension viscosity and optimal optical properties for laser transmission. Large volumes of suspended bubbles, however, interfered with the laser path. In this set, we were able to track bubble nucleation sites and nucleation rates in 4D. This promising technique allows the study of small-scale interactions in two- and three-phase systems, at high imaging rates and at low cost.

Solution of the problem of superposing image and digital map for detection of new objects

NASA Astrophysics Data System (ADS)

Rizaev, I. S.; Miftakhutdinov, D. I.; Takhavova, E. G.

2018-01-01

The problem of superposing the map of the terrain with the image of the terrain is considered. The image of the terrain may be represented in different frequency bands. Further analysis of the results of collation the digital map with the image of the appropriate terrain is described. Also the approach to detection of differences between information represented on the digital map and information of the image of the appropriate area is offered. The algorithm for calculating the values of brightness of the converted image area on the original picture is offered. The calculation is based on using information about the navigation parameters and information according to arranged bench marks. For solving the posed problem the experiments were performed. The results of the experiments are shown in this paper. The presented algorithms are applicable to the ground complex of remote sensing data to assess differences between resulting images and accurate geopositional data. They are also suitable for detecting new objects in the image, based on the analysis of the matching the digital map and the image of corresponding locality.

Image aesthetic quality evaluation using convolution neural network embedded learning

NASA Astrophysics Data System (ADS)

Li, Yu-xin; Pu, Yuan-yuan; Xu, Dan; Qian, Wen-hua; Wang, Li-peng

2017-11-01

A way of embedded learning convolution neural network (ELCNN) based on the image content is proposed to evaluate the image aesthetic quality in this paper. Our approach can not only solve the problem of small-scale data but also score the image aesthetic quality. First, we chose Alexnet and VGG_S to compare for confirming which is more suitable for this image aesthetic quality evaluation task. Second, to further boost the image aesthetic quality classification performance, we employ the image content to train aesthetic quality classification models. But the training samples become smaller and only using once fine-tuning cannot make full use of the small-scale data set. Third, to solve the problem in second step, a way of using twice fine-tuning continually based on the aesthetic quality label and content label respective is proposed, the classification probability of the trained CNN models is used to evaluate the image aesthetic quality. The experiments are carried on the small-scale data set of Photo Quality. The experiment results show that the classification accuracy rates of our approach are higher than the existing image aesthetic quality evaluation approaches.

A dual wavelength imaging system for plasma-surface interaction studies on the National Spherical Torus Experiment Upgrade

DOE PAGES

Scotti, F.; Soukhanovskii, V. A.

2015-12-09

A two-channel spectral imaging system based on a charge injection device radiation-hardened intensified camera was built for studies of plasma-surface interactions on divertor plasma facing components in the National Spherical Torus Experiment Upgrade (NSTX-U) tokamak. By means of commercially available mechanically referenced optical components, the two-wavelength setup images the light from the plasma, relayed by a fiber optic bundle, at two different wavelengths side-by-side on the same detector. Remotely controlled filter wheels are used for narrow band pass and neutral density filters on each optical path allowing for simultaneous imaging of emission at wavelengths differing in brightness up to 3more » orders of magnitude. Applications on NSTX-U will include the measurement of impurity influxes in the lower divertor strike point region and the imaging of plasma-material interaction on the head of the surface analysis probe MAPP (Material Analysis and Particle Probe). Furthermore, the diagnostic setup and initial results from its application on the lithium tokamak experiment are presented.« less

The utility of multiple synthesized views in the recognition of unfamiliar faces.

PubMed

Jones, Scott P; Dwyer, Dominic M; Lewis, Michael B

2017-05-01

The ability to recognize an unfamiliar individual on the basis of prior exposure to a photograph is notoriously poor and prone to errors, but recognition accuracy is improved when multiple photographs are available. In applied situations, when only limited real images are available (e.g., from a mugshot or CCTV image), the generation of new images might provide a technological prosthesis for otherwise fallible human recognition. We report two experiments examining the effects of providing computer-generated additional views of a target face. In Experiment 1, provision of computer-generated views supported better target face recognition than exposure to the target image alone and equivalent performance to that for exposure of multiple photograph views. Experiment 2 replicated the advantage of providing generated views, but also indicated an advantage for multiple viewings of the single target photograph. These results strengthen the claim that identifying a target face can be improved by providing multiple synthesized views based on a single target image. In addition, our results suggest that the degree of advantage provided by synthesized views may be affected by the quality of synthesized material.

"Afterlife experiment": use of MALDI-MS and SIMS imaging for the study of the nitrogen cycle within plants.

PubMed

Seaman, Callie; Flinders, Bryn; Eijkel, Gert; Heeren, Ron M A; Bricklebank, Neil; Clench, Malcolm R

2014-10-21

As part of a project to demonstrate the science of decay, a series of mass spectrometry imaging experiments were performed. The aim was to demonstrate that decay and decomposition are only part of the story and to show pictorially that atoms and molecules from dead plants and animals are incorporated into new life. Radish plants (Raphanus sativus) were grown hydroponically using a nutrient system containing (15)N KNO3 (98% labeled) as the only source of nitrogen. Plants were cropped and left to ferment in water for 2 weeks to create a radish "tea", which was used as a source of nitrogen for radish grown in a second hydroponics experiment. After 5 weeks of growth, the radish plants were harvested and cryosectioned, and sections were imaged by positive-ion MALDI and SIMS mass spectrometry imaging. The presence of labeled species in the plants grown using (15)N KNO3 as nutrient and those grown from the radish "tea" was readily discernible. The uptake of (15)N into a number of identifiable metabolites has been studied by MALDI-MS and SIMS imaging.

Computers in Public Schools: Changing the Image with Image Processing.

ERIC Educational Resources Information Center

Raphael, Jacqueline; Greenberg, Richard

1995-01-01

The kinds of educational technologies selected can make the difference between uninspired, rote computer use and challenging learning experiences. University of Arizona's Image Processing for Teaching Project has worked with over 1,000 teachers to develop image-processing techniques that provide students with exciting, open-ended opportunities for…

Digital Image Quality And Interpretability: Database And Hardcopy Studies

NASA Astrophysics Data System (ADS)

Snyder, H. L.; Maddox, M. E.; Shedivy, D. I.; Turpin, J. A.; Burke, J. J.; Strickland, R. N.

1982-02-01

Two hundred fifty transparencies, displaying a new digital database consisting of 25 degraded versions (5 blur levels x 5 noise levels) of each of 10 digitized, first-generation positive transparencies, were used in two experiments involving 15 trained military photointer-preters. Each image is 86 mm square and represents 40962 8-bit pixels. In the "interpretation" experiment, each photointerpreter (judge) spent approximately two days extracting essential elements of information (EEls) from one degraded version of each scene at a constant Gaussian blur level (FWHM = 40, 84, or 322 Am). In the scaling experiment, each judge assigned a numerical value to each of the 250 images, according to its perceived position on a 10-point NATO-standardized scale (0 = useless through 9 = nearly perfect), to the nearest 0.1 unit. Eighty-eight of the 100 possible values were used by the judges, indicating that 62 categories, based on the Shannon-Wiener measure of information, are needed to scale these hardcopy images. The overall correlation between the scaling and interpretation results was 0.9. Though the main effect of blur was not statistically significant in the interpretation experiment, that of noise was significant, and all main factors (blur, noise, scene, order of battle) and most interactions were statistically significant in the scaling experiment.

Defect-induced mix experiment for NIF

NASA Astrophysics Data System (ADS)

Schmitt, M. J.; Bradley, P. A.; Cobble, J. A.; Hsu, S. C.; Krasheninnikova, N. S.; Kyrala, G. A.; Magelssen, G. R.; Murphy, T. J.; Obrey, K. A.; Tregillis, I. L.; Wysocki, F. J.; Finnegan, S. M.

2013-11-01

The Defect Induced Mix Experiment (DIME-II) will measure the implosion and mix characteristics of CH capsules filled with 5 atmospheres of DT by incorporating mid-Z dopant layers of Ge and Ga. This polar direct drive (PDD) experiment also will demonstrate the filling of a CH capsule at target chamber center using a fill tube. Diagnostics for these experiments include areal x-ray backlighting to obtain early time images of the implosion trajectory and a multiple-monochromatic imager (MMI) to collect spectrally-resolved images of the capsule dopant line emission near bangtime. The inclusion of two (or more) thin dopant layers at separate depths within the capsule shell facilitates spatial correlation of mix between the layers and the hot gas core on a single shot. The dopant layers are typically 2 μm thick and contain dopant concentrations of 1.5%. Three dimensional Hydra simulations have been performed to assess the effects of PDD asymmetry on capsule performance.

Hypomanic Experience in Young Adults Confers Vulnerability to Intrusive Imagery After Experimental Trauma

PubMed Central

Malik, Aiysha; Goodwin, Guy M.; Hoppitt, Laura

2014-01-01

Emotional mental imagery occurs across anxiety disorders, yet is neglected in bipolar disorder despite high anxiety comorbidity. Furthermore, a heightened susceptibility to developing intrusive mental images of stressful events in bipolar disorder and people vulnerable to it (with hypomanic experience) has been suggested. The current study assessed, prospectively, whether significant hypomanic experience (contrasting groups scoring high vs. low on the Mood Disorder Questionnaire, MDQ) places individuals at increased risk of visual reexperiencing after experimental stress. A total of 110 young adults watched a trauma film and recorded film-related intrusive images for 6 days. Compared to the low MDQ group, the high MDQ group experienced approximately twice as many intrusive images, substantiated by convergent measures. Findings suggest hypomanic experience is associated with developing more frequent intrusive imagery of a stressor. Because mental imagery powerfully affects emotion, such imagery may contribute to bipolar mood instability and offer a cognitive treatment target. PMID:25419498

Effects of Exposure to Advertisements on Audience Impressions

NASA Astrophysics Data System (ADS)

Hasegawa, Hiroshi; Sato, Mie; Kasuga, Masao; Nagao, Yoshihide; Shono, Toru; Norose, Yuka; Oku, Ritsuya; Nogami, Akira; Miyazawa, Yoshitaka

This study investigated effects of listening and/or watching commercial-messages (CMs) on audience impressions. We carried out experiments of TV advertisements presentation in conditions of audio only, video only, and audio-video. As results, we confirmed the following two effects: image-multiple effect, that is, the audience brings to mind various images that are not directly expressed in the content, and marking-up effect, that is, the audience concentrates on some images that are directly expressed in the content. The image-multiple effect, in particular, strongly appeared under the audio only condition. Next, we investigated changes in the following seven subjective responses; usage image, experience, familiarity, exclusiveness, feeling at home, affection, and willingness to buy, after exposure to advertisements under conditions of audio only and audio-video. As a result, noting that the image-multiple effect became stronger as the evaluation scores of the responses increased.

Low-temperature magnetic resonance imaging with 2.8 μm isotropic resolution

NASA Astrophysics Data System (ADS)

Chen, Hsueh-Ying; Tycko, Robert

2018-02-01

We demonstrate the feasibility of high-resolution 1H magnetic resonance imaging (MRI) at low temperatures by obtaining an MRI image of 20 μm diameter glass beads in glycerol/water at 28 K with 2.8 μm isotropic resolution. The experiments use a recently-described MRI apparatus (Moore and Tycko, 2015) with minor modifications. The sample is contained within a radio-frequency microcoil with 150 μm inner diameter. Sensitivity is additionally enhanced by paramagnetic doping, optimization of the sample temperature, three-dimensional phase-encoding of k-space data, pulsed spin-lock detection of 1H nuclear magnetic resonance signals, and spherical sampling of k-space. We verify that the actual image resolution is 2.7 ± 0.3 μm by quantitative comparisons of experimental and calculated images. Our imaging approach is compatible with dynamic nuclear polarization, providing a path to significantly higher resolution in future experiments.

Comparison of mechanisms involved in image enhancement of Tissue Harmonic Imaging

NASA Astrophysics Data System (ADS)

Cleveland, Robin O.; Jing, Yuan

2006-05-01

Processes that have been suggested as responsible for the improved imaging in Tissue Harmonic Imaging (THI) include: 1) reduced sensitivity to reverberation, 2) reduced sensitivity to aberration, and 3) reduction in the amplitude of diffraction side lobes. A three-dimensional model of the forward propagation of nonlinear sound beams in media with arbitrary spatial properties (a generalized KZK equation) was developed and solved using a time-domain code. The numerical simulations were validated through experiments with tissue mimicking phantoms. The impact of aberration from tissue-like media was determined through simulations using three-dimensional maps of tissue properties derived from datasets available through the Visible Female Project. The experiments and simulations demonstrated that second harmonic imaging suffers less clutter from reverberation and side-lobes but is not immune to aberration effects. The results indicate that side lobe suppression is the most significant reason for the improvement of second harmonic imaging.

Breadboard linear array scan imager using LSI solid-state technology

NASA Technical Reports Server (NTRS)

Tracy, R. A.; Brennan, J. A.; Frankel, D. G.; Noll, R. E.

1976-01-01

The performance of large scale integration photodiode arrays in a linear array scan (pushbroom) breadboard was evaluated for application to multispectral remote sensing of the earth's resources. The technical approach, implementation, and test results of the program are described. Several self scanned linear array visible photodetector focal plane arrays were fabricated and evaluated in an optical bench configuration. A 1728-detector array operating in four bands (0.5 - 1.1 micrometer) was evaluated for noise, spectral response, dynamic range, crosstalk, MTF, noise equivalent irradiance, linearity, and image quality. Other results include image artifact data, temporal characteristics, radiometric accuracy, calibration experience, chip alignment, and array fabrication experience. Special studies and experimentation were included in long array fabrication and real-time image processing for low-cost ground stations, including the use of computer image processing. High quality images were produced and all objectives of the program were attained.

Multimodal imaging of cutaneous wound tissue

NASA Astrophysics Data System (ADS)

Zhang, Shiwu; Gnyawali, Surya; Huang, Jiwei; Ren, Wenqi; Gordillo, Gayle; Sen, Chandan K.; Xu, Ronald

2015-01-01

Quantitative assessment of wound tissue ischemia, perfusion, and inflammation provides critical information for appropriate detection, staging, and treatment of chronic wounds. However, few methods are available for simultaneous assessment of these tissue parameters in a noninvasive and quantitative fashion. We integrated hyperspectral, laser speckle, and thermographic imaging modalities in a single-experimental setup for multimodal assessment of tissue oxygenation, perfusion, and inflammation characteristics. Algorithms were developed for appropriate coregistration between wound images acquired by different imaging modalities at different times. The multimodal wound imaging system was validated in an occlusion experiment, where oxygenation and perfusion maps of a healthy subject's upper extremity were continuously monitored during a postocclusive reactive hyperemia procedure and compared with standard measurements. The system was also tested in a clinical trial where a wound of three millimeters in diameter was introduced on a healthy subject's lower extremity and the healing process was continuously monitored. Our in vivo experiments demonstrated the clinical feasibility of multimodal cutaneous wound imaging.

Shuttle imaging radar views the Earth from Challenger: The SIR-B experiment

NASA Technical Reports Server (NTRS)

Ford, J. P.; Cimino, J. B.; Holt, B.; Ruzek, M. R.

1986-01-01

In October 1984, SIR-B obtained digital image data of about 6.5 million km2 of the Earth's surface. The coverage is mostly of selected experimental test sites located between latitudes 60 deg north and 60 deg south. Programmed adjustments made to the look angle of the steerable radar antenna and to the flight attitude of the shuttle during the mission permitted collection of multiple-incidence-angle coverage or extended mapping coverage as required for the experiments. The SIR-B images included here are representative of the coverage obtained for scientific studies in geology, cartography, hydrology, vegetation cover, and oceanography. The relations between radar backscatter and incidence angle for discriminating various types of surfaces, and the use of multiple-incidence-angle SIR-B images for stereo measurement and viewing, are illustrated with examples. Interpretation of the images is facilitated by corresponding images or photographs obtained by different sensors or by sketch maps or diagrams.

Harmonic vibro-acoustography.

PubMed

Chen, Shigao; Kinnick, Randall R; Greenleaf, James F; Fatemi, Mostafa

2007-07-01

Vibro-acoustography is an imaging method that uses the radiation force of two interfering ultrasound beams of slightly different frequency to probe an object. An image is made using the acoustic emission resulted from the object vibration at the difference frequency. In this paper, the feasibility of imaging objects at twice the difference frequency (harmonic acoustic emission) is studied. Several possible origins of harmonic acoustic emission are explored. As an example, it is shown that microbubbles close to resonance can produce significant harmonic acoustic emission due to its high nonlinearity. Experiments demonstrate that, compared to the fundamental acoustic emission, harmonic acoustic emission greatly improves the contrast between microbubbles and other objects in vibro-acoustography (an improvement of 17-23 dB in these experiments). Applications of this technique include imaging the nonlinearity of the object and selective detection of microbubbles for perfusion imaging. The impact of microbubble destruction during the imaging process also is discussed.

Histogram-based normalization technique on human brain magnetic resonance images from different acquisitions.

PubMed

Sun, Xiaofei; Shi, Lin; Luo, Yishan; Yang, Wei; Li, Hongpeng; Liang, Peipeng; Li, Kuncheng; Mok, Vincent C T; Chu, Winnie C W; Wang, Defeng

2015-07-28

Intensity normalization is an important preprocessing step in brain magnetic resonance image (MRI) analysis. During MR image acquisition, different scanners or parameters would be used for scanning different subjects or the same subject at a different time, which may result in large intensity variations. This intensity variation will greatly undermine the performance of subsequent MRI processing and population analysis, such as image registration, segmentation, and tissue volume measurement. In this work, we proposed a new histogram normalization method to reduce the intensity variation between MRIs obtained from different acquisitions. In our experiment, we scanned each subject twice on two different scanners using different imaging parameters. With noise estimation, the image with lower noise level was determined and treated as the high-quality reference image. Then the histogram of the low-quality image was normalized to the histogram of the high-quality image. The normalization algorithm includes two main steps: (1) intensity scaling (IS), where, for the high-quality reference image, the intensities of the image are first rescaled to a range between the low intensity region (LIR) value and the high intensity region (HIR) value; and (2) histogram normalization (HN),where the histogram of low-quality image as input image is stretched to match the histogram of the reference image, so that the intensity range in the normalized image will also lie between LIR and HIR. We performed three sets of experiments to evaluate the proposed method, i.e., image registration, segmentation, and tissue volume measurement, and compared this with the existing intensity normalization method. It is then possible to validate that our histogram normalization framework can achieve better results in all the experiments. It is also demonstrated that the brain template with normalization preprocessing is of higher quality than the template with no normalization processing. We have proposed a histogram-based MRI intensity normalization method. The method can normalize scans which were acquired on different MRI units. We have validated that the method can greatly improve the image analysis performance. Furthermore, it is demonstrated that with the help of our normalization method, we can create a higher quality Chinese brain template.

Effect of High Impact or Non-impact Loading Activity on Bone Bending Stiffness and Mineral Density

NASA Technical Reports Server (NTRS)

Liang, Michael T. C.; Arnnud, Sara B.; Steele, Charles R.; Moreno, Alexjandro

2003-01-01

Material properties of conical bone, including mineral density (BMD) and its geometry is closely related to its load-carrying capacity. These two primary components determine the strength of conical bone. High impact loading involving acceleration and deceleration movements used in gymnastics induce higher BMD of the affected bone compared to the non-impact acceleration and deceleration movements used in swimming. Study of these two groups of athletes on bone bending stiffness has not been reported. The purpose of this study was to compare differences in bone bending stiffness and BMD between competitive female synchronized swimmers and female gymnasts. Thirteen world class female synchronized swimmers (SYN) and 8 female gymnasts (GYM), mean age 21 +/- 2.9 yr. were recruited for this study. We used a mechanical response tissue analyzer (Gaitscan, NJ) to calculate EI, where E is Young's modulus of elasticity and I is the cross-sectional moment of inertia. EI was obtained from tissue response to a vibration probe placed directly on the skin of the mid-region of tibia and ulna. BMD of the heel and wrist were measured with a probe densitometer (PIXI, Lunor, WI). The SYN were taller than (p < 0.05) the GYM but weighed the same as the GYM. EI obtained from tibia and ulna of the SYN (291 +/- 159 and 41 +/- 19.4, respectively) were not significantly different from thc GYM (285 +/- 140 and 44 +/- 18.3, respectively). BMD of the heel and wrist in GYM were higher than in SYN (p < 0.001). High impact weight-bearing activities promote similar bone strength but greater BMD response than non-impact activities performed in a buoyant environment.

Search for C II Emission on Cosmological Scales at Redshift Z ˜ 2.6

NASA Astrophysics Data System (ADS)

Pullen, Anthony R.; Serra, Paolo; Chang, Tzu-Ching; Doré, Olivier; Ho, Shirley

2018-05-01

We present a search for Cii emission over cosmological scales at high-redshifts. The Cii line is a prime candidate to be a tracer of star formation over large-scale structure since it is one of the brightest emission lines from galaxies. Redshifted Cii emission appears in the submillimeter regime, meaning it could potentially be present in the higher frequency intensity data from the Planck satellite used to measure the cosmic infrared background (CIB). We search for Cii emission over redshifts z = 2 - 3.2 in the Planck 545 GHz intensity map by cross-correlating the 3 highest frequency Planck maps with spectroscopic quasars and CMASS galaxies from the Sloan Digital Sky Survey III (SDSS-III), which we then use to jointly fit for Cii intensity, CIB parameters, and thermal Sunyaev-Zeldovich (SZ) emission. We report a measurement of an anomalous emission I_ν =6.6^{+5.0}_{-4.8}× 10^4Jy/sr at 95% confidence, which could be explained by Cii emission, favoring collisional excitation models of Cii emission that tend to be more optimistic than models based on Cii luminosity scaling relations from local measurements; however, a comparison of Bayesian information criteria reveal that this model and the CIB & SZ only model are equally plausible. Thus, more sensitive measurements will be needed to confirm the existence of large-scale Cii emission at high redshifts. Finally, we forecast that intensity maps from Planck cross-correlated with quasars from the Dark Energy Spectroscopic Instrument (DESI) would increase our sensitivity to Cii emission by a factor of 5, while the proposed Primordial Inflation Explorer (PIXIE) could increase the sensitivity further.

Don't Look down: Emotional Arousal Elevates Height Perception

ERIC Educational Resources Information Center

Stefanucci, Jeanine K.; Storbeck, Justin

2009-01-01

In a series of experiments, it was found that emotional arousal can influence height perception. In Experiment 1, participants viewed either arousing or nonarousing images before estimating the height of a 2-story balcony and the size of a target on the ground below the balcony. People who viewed arousing images overestimated height and target…

Flow Visualization Studies in the Novacor Left Ventricular Assist System CRADA PC91-002, Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Borovetz, H.S.; Shaffer, F.; Schaub, R.

This paper discusses a series of experiments to visualize and measure flow fields in the Novacor left ventricular assist system (LVAS). The experiments utilize a multiple exposure, optical imaging technique called fluorescent image tracking velocimetry (FITV) to hack the motion of small, neutrally-buoyant particles in a flowing fluid.

Mission Specialist Hawley works with the SWUIS experiment

NASA Image and Video Library

2013-11-18

STS093-350-022 (22-27 July 1999) --- Astronaut Steven A. Hawley, mission specialist, works with the Southwest Ultraviolet Imaging System (SWUIS) experiment onboard the Earth-orbiting Space Shuttle Columbia. The SWUIS is based around a Maksutov-design Ultraviolet (UV) telescope and a UV-sensitive, image-intensified Charge-Coupled Device (CCD) camera that frames at video frame rates.

Ethical Considerations of Children's Digital Image-Making and Image-Audiancing in Early Childhood Environments

ERIC Educational Resources Information Center

Eckhoff, Angela

2015-01-01

This research examines a multi-year investigation of preschoolers' experiences participating in a media-driven exploration of informal play experiences as a means to engage children as artists, researchers, and documenters of their own worlds. In this writing, I will explore the ethical issues that arise for adult researchers engaged in…

Visualization of hydrogen injection in a scramjet engine by simultaneous PLIF imaging and laser holographic imaging

NASA Technical Reports Server (NTRS)

Anderson, Robert C.; Trucco, Richard E.; Rubin, L. F.; Swain, D. M.

1992-01-01

Flowfield characterization has been accomplished for several fuel injector configurations using simultaneous planar laser induced fluorescence (PLIF) and laser holographic imaging (LHI). The experiments were carried out in the GASL-NASA HYPULSE real gas expansion tube facility, a pulsed facility with steady test times of about 350 microsec. The tests were done at simulated Mach numbers 13.5 and 17. The focus of this paper is on the measurement technologies used and their application in a research facility. The HYPULSE facility, the models used for the experiments, and the setup for the LHI and PLIF measurements are described. Measurement challenges and solutions are discussed. Results are presented for experiments with several fuel injector configurations and several equivalence ratios.

It's not just a "woman thing:" the current state of normative discontent.

PubMed

Tantleff-Dunn, Stacey; Barnes, Rachel D; Larose, Jessica Gokee

2011-01-01

This study assessed "normative discontent," the concept that most women experience weight dissatisfaction, as an emerging societal stereotype for women and men (Rodin, Silberstein, & Streigel-Moore, 1984). Participants (N = 472) completed measures of stereotypes, eating disorders, and body image. Normative discontent stereotypes were pervasive for women and men. Endorsing stereotypes varied by sex and participants' own disturbance, with trends towards eating disorder symptomotology being positively correlated with stereotype endorsement. Individuals with higher levels of body image and eating disturbance may normalize their behavior by perceiving that most people share their experiences. Future research needs to test prevention and intervention strategies that incorporate the discrepancies between body image/eating-related stereotypes and reality with focus on preventing normalization of such experiences.

Scalable High Performance Image Registration Framework by Unsupervised Deep Feature Representations Learning

PubMed Central

Wu, Guorong; Kim, Minjeong; Wang, Qian; Munsell, Brent C.

2015-01-01

Feature selection is a critical step in deformable image registration. In particular, selecting the most discriminative features that accurately and concisely describe complex morphological patterns in image patches improves correspondence detection, which in turn improves image registration accuracy. Furthermore, since more and more imaging modalities are being invented to better identify morphological changes in medical imaging data,, the development of deformable image registration method that scales well to new image modalities or new image applications with little to no human intervention would have a significant impact on the medical image analysis community. To address these concerns, a learning-based image registration framework is proposed that uses deep learning to discover compact and highly discriminative features upon observed imaging data. Specifically, the proposed feature selection method uses a convolutional stacked auto-encoder to identify intrinsic deep feature representations in image patches. Since deep learning is an unsupervised learning method, no ground truth label knowledge is required. This makes the proposed feature selection method more flexible to new imaging modalities since feature representations can be directly learned from the observed imaging data in a very short amount of time. Using the LONI and ADNI imaging datasets, image registration performance was compared to two existing state-of-the-art deformable image registration methods that use handcrafted features. To demonstrate the scalability of the proposed image registration framework image registration experiments were conducted on 7.0-tesla brain MR images. In all experiments, the results showed the new image registration framework consistently demonstrated more accurate registration results when compared to state-of-the-art. PMID:26552069

Scalable High-Performance Image Registration Framework by Unsupervised Deep Feature Representations Learning.

PubMed

Wu, Guorong; Kim, Minjeong; Wang, Qian; Munsell, Brent C; Shen, Dinggang

2016-07-01

Feature selection is a critical step in deformable image registration. In particular, selecting the most discriminative features that accurately and concisely describe complex morphological patterns in image patches improves correspondence detection, which in turn improves image registration accuracy. Furthermore, since more and more imaging modalities are being invented to better identify morphological changes in medical imaging data, the development of deformable image registration method that scales well to new image modalities or new image applications with little to no human intervention would have a significant impact on the medical image analysis community. To address these concerns, a learning-based image registration framework is proposed that uses deep learning to discover compact and highly discriminative features upon observed imaging data. Specifically, the proposed feature selection method uses a convolutional stacked autoencoder to identify intrinsic deep feature representations in image patches. Since deep learning is an unsupervised learning method, no ground truth label knowledge is required. This makes the proposed feature selection method more flexible to new imaging modalities since feature representations can be directly learned from the observed imaging data in a very short amount of time. Using the LONI and ADNI imaging datasets, image registration performance was compared to two existing state-of-the-art deformable image registration methods that use handcrafted features. To demonstrate the scalability of the proposed image registration framework, image registration experiments were conducted on 7.0-T brain MR images. In all experiments, the results showed that the new image registration framework consistently demonstrated more accurate registration results when compared to state of the art.

GOES Satellite Observations for the FIRE/SRB Wisconsin Experiment Region from October 11 Through November 2, 1986

NASA Technical Reports Server (NTRS)

Whitlock, Charles H.; T R. acraitch, Eric J.

1987-01-01

A map, concise tables, and satellite images are presented which show ground-site locations, GOES visible/infrared instrument counts above each site, and cloud spatial distribution for the experiment region from 11 October through 2 November 1986. The cloud images are presented near times of the afternoon NOAA-9 satellite overpasses in order to provide a qualitative aid in the interpretation of TOVS, AVHRR, and heat budget data during the FIRE/SRB experiment.

Magnetoacoustic tomography with magnetic induction for high-resolution bioimepedance imaging through vector source reconstruction under the static field of MRI magnet

PubMed Central

Mariappan, Leo; Hu, Gang; He, Bin

2014-01-01

Purpose: Magnetoacoustic tomography with magnetic induction (MAT-MI) is an imaging modality to reconstruct the electrical conductivity of biological tissue based on the acoustic measurements of Lorentz force induced tissue vibration. This study presents the feasibility of the authors' new MAT-MI system and vector source imaging algorithm to perform a complete reconstruction of the conductivity distribution of real biological tissues with ultrasound spatial resolution. Methods: In the present study, using ultrasound beamformation, imaging point spread functions are designed to reconstruct the induced vector source in the object which is used to estimate the object conductivity distribution. Both numerical studies and phantom experiments are performed to demonstrate the merits of the proposed method. Also, through the numerical simulations, the full width half maximum of the imaging point spread function is calculated to estimate of the spatial resolution. The tissue phantom experiments are performed with a MAT-MI imaging system in the static field of a 9.4 T magnetic resonance imaging magnet. Results: The image reconstruction through vector beamformation in the numerical and experimental studies gives a reliable estimate of the conductivity distribution in the object with a ∼1.5 mm spatial resolution corresponding to the imaging system frequency of 500 kHz ultrasound. In addition, the experiment results suggest that MAT-MI under high static magnetic field environment is able to reconstruct images of tissue-mimicking gel phantoms and real tissue samples with reliable conductivity contrast. Conclusions: The results demonstrate that MAT-MI is able to image the electrical conductivity properties of biological tissues with better than 2 mm spatial resolution at 500 kHz, and the imaging with MAT-MI under a high static magnetic field environment is able to provide improved imaging contrast for biological tissue conductivity reconstruction. PMID:24506649

Integrated Spectral Low Noise Image Sensor with Nanowire Polarization Filters for Low Contrast Imaging

DTIC Science & Technology

2015-11-05

AFRL-AFOSR-VA-TR-2015-0359 Integrated Spectral Low Noise Image Sensor with Nanowire Polarization Filters for Low Contrast Imaging Viktor Gruev...To) 02/15/2011 - 08/15/2015 4. TITLE AND SUBTITLE Integrated Spectral Low Noise Image Sensor with Nanowire Polarization Filters for Low Contrast...investigate alternative spectral imaging architectures based on my previous experience in this research area. I will develop nanowire polarization

Research on simulated infrared image utility evaluation using deep representation

NASA Astrophysics Data System (ADS)

Zhang, Ruiheng; Mu, Chengpo; Yang, Yu; Xu, Lixin

2018-01-01

Infrared (IR) image simulation is an important data source for various target recognition systems. However, whether simulated IR images could be used as training data for classifiers depends on the features of fidelity and authenticity of simulated IR images. For evaluation of IR image features, a deep-representation-based algorithm is proposed. Being different from conventional methods, which usually adopt a priori knowledge or manually designed feature, the proposed method can extract essential features and quantitatively evaluate the utility of simulated IR images. First, for data preparation, we employ our IR image simulation system to generate large amounts of IR images. Then, we present the evaluation model of simulated IR image, for which an end-to-end IR feature extraction and target detection model based on deep convolutional neural network is designed. At last, the experiments illustrate that our proposed method outperforms other verification algorithms in evaluating simulated IR images. Cross-validation, variable proportion mixed data validation, and simulation process contrast experiments are carried out to evaluate the utility and objectivity of the images generated by our simulation system. The optimum mixing ratio between simulated and real data is 0.2≤γ≤0.3, which is an effective data augmentation method for real IR images.

X-ray penumbral imaging diagnostic developments at the National Ignition Facility

NASA Astrophysics Data System (ADS)

Bachmann, B.; Abu-Shawareb, H.; Alexander, N.; Ayers, J.; Bailey, C. G.; Bell, P.; Benedetti, L. R.; Bradley, D.; Collins, G.; Divol, L.; Döppner, T.; Felker, S.; Field, J.; Forsman, A.; Galbraith, J. D.; Hardy, C. M.; Hilsabeck, T.; Izumi, N.; Jarrot, C.; Kilkenny, J.; Kramer, S.; Landen, O. L.; Ma, T.; MacPhee, A.; Masters, N.; Nagel, S. R.; Pak, A.; Patel, P.; Pickworth, L. A.; Ralph, J. E.; Reed, C.; Rygg, J. R.; Thorn, D. B.

2017-08-01

X-ray penumbral imaging has been successfully fielded on a variety of inertial confinement fusion (ICF) capsule implosion experiments on the National Ignition Facility (NIF). We have demonstrated sub-5 μm resolution imaging of stagnated plasma cores (hot spots) at x-ray energies from 6 to 30 keV. These measurements are crucial for improving our understanding of the hot deuterium-tritium fuel assembly, which can be affected by various mechanisms, including complex 3-D perturbations caused by the support tent, fill tube or capsule surface roughness. Here we present the progress on several approaches to improve x-ray penumbral imaging experiments on the NIF. We will discuss experimental setups that include penumbral imaging from multiple lines-of-sight, target mounted penumbral apertures and variably filtered penumbral images. Such setups will improve the signal-to-noise ratio and the spatial imaging resolution, with the goal of enabling spatially resolved measurements of the hot spot electron temperature and material mix in ICF implosions.

A two layer chaotic encryption scheme of secure image transmission for DCT precoded OFDM-VLC transmission

NASA Astrophysics Data System (ADS)

Wang, Zhongpeng; Chen, Fangni; Qiu, Weiwei; Chen, Shoufa; Ren, Dongxiao

2018-03-01

In this paper, a two-layer image encryption scheme for a discrete cosine transform (DCT) precoded orthogonal frequency division multiplexing (OFDM) visible light communication (VLC) system is proposed. Firstly, in the proposed scheme the transmitted image is first encrypted by a chaos scrambling sequence,which is generated from the hybrid 4-D hyper- and Arnold map in the upper-layer. After that, the encrypted image is converted into digital QAM modulation signal, which is re-encrypted by chaos scrambling sequence based on Arnold map in physical layer to further enhance the security of the transmitted image. Moreover, DCT precoding is employed to improve BER performance of the proposed system and reduce the PAPR of OFDM signal. The BER and PAPR performances of the proposed system are evaluated by simulation experiments. The experiment results show that the proposed two-layer chaos scrambling schemes achieve image secure transmission for image-based OFDM VLC. Furthermore, DCT precoding can reduce the PAPR and improve the BER performance of OFDM-based VLC.

3D super resolution range-gated imaging for canopy reconstruction and measurement

NASA Astrophysics Data System (ADS)

Huang, Hantao; Wang, Xinwei; Sun, Liang; Lei, Pingshun; Fan, Songtao; Zhou, Yan

2018-01-01

In this paper, we proposed a method of canopy reconstruction and measurement based on 3D super resolution range-gated imaging. In this method, high resolution 2D intensity images are grasped by active gate imaging, and 3D images of canopy are reconstructed by triangular-range-intensity correlation algorithm at the same time. A range-gated laser imaging system(RGLIS) is established based on 808 nm diode laser and gated intensified charge-coupled device (ICCD) camera with 1392´1040 pixels. The proof experiments have been performed for potted plants located 75m away and trees located 165m away. The experiments show it that can acquire more than 1 million points per frame, and 3D imaging has the spatial resolution about 0.3mm at the distance of 75m and the distance accuracy about 10 cm. This research is beneficial for high speed acquisition of canopy structure and non-destructive canopy measurement.

Characterization of controlled bone defects using 2D and 3D ultrasound imaging techniques.

PubMed

Parmar, Biren J; Longsine, Whitney; Sabonghy, Eric P; Han, Arum; Tasciotti, Ennio; Weiner, Bradley K; Ferrari, Mauro; Righetti, Raffaella

2010-08-21

Ultrasound is emerging as an attractive alternative modality to standard x-ray and CT methods for bone assessment applications. As of today, however, there is a lack of systematic studies that investigate the performance of diagnostic ultrasound techniques in bone imaging applications. This study aims at understanding the performance limitations of new ultrasound techniques for imaging bones in controlled experiments in vitro. Experiments are performed on samples of mammalian and non-mammalian bones with controlled defects with size ranging from 400 microm to 5 mm. Ultrasound findings are statistically compared with those obtained from the same samples using standard x-ray imaging modalities and optical microscopy. The results of this study demonstrate that it is feasible to use diagnostic ultrasound imaging techniques to assess sub-millimeter bone defects in real time and with high accuracy and precision. These results also demonstrate that ultrasound imaging techniques perform comparably better than x-ray imaging and optical imaging methods, in the assessment of a wide range of controlled defects both in mammalian and non-mammalian bones. In the future, ultrasound imaging techniques might provide a cost-effective, real-time, safe and portable diagnostic tool for bone imaging applications.

Reach out to one and you reach out to many: social touch affects third-party observers.

PubMed

Schirmer, Annett; Reece, Christy; Zhao, Claris; Ng, Erik; Wu, Esther; Yen, Shih-Cheng

2015-02-01

Casual social touch influences emotional perceptions, attitudes, and behaviours of interaction partners. We asked whether these influences extend to third-party observers. To this end, we developed the Social Touch Picture Set comprising line drawings of dyadic interactions, half of which entailed publicly acceptable casual touch and half of which served as no-touch controls. In Experiment 1, participants provided basic image norms by rating how frequently they observed a displayed touch gesture in everyday life and how comfortable they were observing it. Results implied that some touch gestures were observed more frequently and with greater comfort than others (e.g., handshake vs. hug). All gestures, however, obtained rating scores suitable for inclusion in Experiments 2 and 3. In Experiment 2, participants rated perceived valence, arousal, and likeability of randomly presented touch and no-touch images without being explicitly informed about touch. Image characters seemed more positive, aroused, and likeable when they touched as compared to when they did not touch. Image characters seemed more negative and aroused, but were equally likeable, when they received touch as compared to when there was no physical contact. In Experiment 3, participants passively viewed touch and no-touch images while their eye movements were recorded. Differential gazing at touch as compared to no-touch images emerged within the first 500 ms following image exposure and was largely restricted to the characters' upper body. Gazing at the touching body parts (e.g., hands) was minimal and largely unaffected by touch, suggesting that touch processing occurred outside the focus of visual attention. Together, these findings establish touch as an important visual cue and provide novel insights into how this cue modulates socio-emotional processing in third-party observers. © 2014 The British Psychological Society.

Experiments on automatic classification of tissue malignancy in the field of digital pathology

NASA Astrophysics Data System (ADS)

Pereira, J.; Barata, R.; Furtado, Pedro

2017-06-01

Automated analysis of histological images helps diagnose and further classify breast cancer. Totally automated approaches can be used to pinpoint images for further analysis by the medical doctor. But tissue images are especially challenging for either manual or automated approaches, due to mixed patterns and textures, where malignant regions are sometimes difficult to detect unless they are in very advanced stages. Some of the major challenges are related to irregular and very diffuse patterns, as well as difficulty to define winning features and classifier models. Although it is also hard to segment correctly into regions, due to the diffuse nature, it is still crucial to take low-level features over individualized regions instead of the whole image, and to select those with the best outcomes. In this paper we report on our experiments building a region classifier with a simple subspace division and a feature selection model that improves results over image-wide and/or limited feature sets. Experimental results show modest accuracy for a set of classifiers applied over the whole image, while the conjunction of image division, per-region low-level extraction of features and selection of features, together with the use of a neural network classifier achieved the best levels of accuracy for the dataset and settings we used in the experiments. Future work involves deep learning techniques, adding structures semantics and embedding the approach as a tumor finding helper in a practical Medical Imaging Application.

Fine-grained visual marine vessel classification for coastal surveillance and defense applications

NASA Astrophysics Data System (ADS)

Solmaz, Berkan; Gundogdu, Erhan; Karaman, Kaan; Yücesoy, Veysel; Koç, Aykut

2017-10-01

The need for capabilities of automated visual content analysis has substantially increased due to presence of large number of images captured by surveillance cameras. With a focus on development of practical methods for extracting effective visual data representations, deep neural network based representations have received great attention due to their success in visual categorization of generic images. For fine-grained image categorization, a closely related yet a more challenging research problem compared to generic image categorization due to high visual similarities within subgroups, diverse applications were developed such as classifying images of vehicles, birds, food and plants. Here, we propose the use of deep neural network based representations for categorizing and identifying marine vessels for defense and security applications. First, we gather a large number of marine vessel images via online sources grouping them into four coarse categories; naval, civil, commercial and service vessels. Next, we subgroup naval vessels into fine categories such as corvettes, frigates and submarines. For distinguishing images, we extract state-of-the-art deep visual representations and train support-vector-machines. Furthermore, we fine tune deep representations for marine vessel images. Experiments address two scenarios, classification and verification of naval marine vessels. Classification experiment aims coarse categorization, as well as learning models of fine categories. Verification experiment embroils identification of specific naval vessels by revealing if a pair of images belongs to identical marine vessels by the help of learnt deep representations. Obtaining promising performance, we believe these presented capabilities would be essential components of future coastal and on-board surveillance systems.

Improved in-plane visibility of tumors using breast tomosynthesis

NASA Astrophysics Data System (ADS)

Ruschin, Mark; Timberg, Pontus; Svahn, Tony; Andersson, Ingvar; Hemdal, Bengt; Mattsson, Sören; Båth, Magnus; Tingberg, Anders

2007-03-01

The purpose of this work was to evaluate and compare the visibility of tumors in digital mammography (DM) and breast tomosynthesis (BT) images. Images of the same women were acquired on both a DM system (Mammomat Novation, Siemens) and a BT prototype system adapted from the same type of DM system. Simulated 3D tumors (average dimension: 8.4 mm x 6.6 mm x 5 mm) were projected and added to each DM image as well as each BT projection image prior to 3D reconstruction. The same beam quality and approximately the same total absorbed dose were used for each breast image acquisition on both systems. Two simulated tumors were added to each of thirty breast scans, yielding sixty cases. A series of 4-alternative forced choice (4-AFC) human observer performance experiments were conducted in order to determine what projected tumor signal intensity in the DM images would be needed to achieve the same detectability as in the reconstructed BT images. Nine observers participated. For the BT experiment, when the tumor signal intensity on the central projection was 0.010 the mean percent of correct responses (PC) was measured to be 81.5%, which converted to a detectability index value (d') of 1.96. For the DM experiments, the same detectability was achieved at a signal intensity determined to be 0.038. Equivalent tumor detection in BT images were thus achieved at around four times less projected signal intensity than in DM images, indicating that the use of BT may lead to earlier detection of breast cancer.

Methods for Dichoptic Stimulus Presentation in Functional Magnetic Resonance Imaging - A Review

PubMed Central

Choubey, Bhaskar; Jurcoane, Alina; Muckli, Lars; Sireteanu, Ruxandra

2009-01-01

Dichoptic stimuli (different stimuli displayed to each eye) are increasingly being used in functional brain imaging experiments using visual stimulation. These studies include investigation into binocular rivalry, interocular information transfer, three-dimensional depth perception as well as impairments of the visual system like amblyopia and stereodeficiency. In this paper, we review various approaches of displaying dichoptic stimulus used in functional magnetic resonance imaging experiments. These include traditional approaches of using filters (red-green, red-blue, polarizing) with optical assemblies as well as newer approaches of using bi-screen goggles. PMID:19526076

FRAP Analysis: Accounting for Bleaching during Image Capture

PubMed Central

Wu, Jun; Shekhar, Nandini; Lele, Pushkar P.; Lele, Tanmay P.

2012-01-01

The analysis of Fluorescence Recovery After Photobleaching (FRAP) experiments involves mathematical modeling of the fluorescence recovery process. An important feature of FRAP experiments that tends to be ignored in the modeling is that there can be a significant loss of fluorescence due to bleaching during image capture. In this paper, we explicitly include the effects of bleaching during image capture in the model for the recovery process, instead of correcting for the effects of bleaching using reference measurements. Using experimental examples, we demonstrate the usefulness of such an approach in FRAP analysis. PMID:22912750

Image compression software for the SOHO LASCO and EIT experiments

NASA Technical Reports Server (NTRS)

Grunes, Mitchell R.; Howard, Russell A.; Hoppel, Karl; Mango, Stephen A.; Wang, Dennis

1994-01-01

This paper describes the lossless and lossy image compression algorithms to be used on board the Solar Heliospheric Observatory (SOHO) in conjunction with the Large Angle Spectrometric Coronograph and Extreme Ultraviolet Imaging Telescope experiments. It also shows preliminary results obtained using similar prior imagery and discusses the lossy compression artifacts which will result. This paper is in part intended for the use of SOHO investigators who need to understand the results of SOHO compression in order to better allocate the transmission bits which they have been allocated.

Computer Assisted Thermography And Its Application In Ovulation Detection

NASA Astrophysics Data System (ADS)

Rao, K. H.; Shah, A. V.

1984-08-01

Hardware and software of a computer-assisted image analyzing system used for infrared images in medical applications are discussed. The application of computer-assisted thermography (CAT) as a complementary diagnostic tool in centralized diagnostic management is proposed. The authors adopted 'Computer Assisted Thermography' to study physiological changes in the breasts related to the hormones characterizing the menstrual cycle of a woman. Based on clinical experi-ments followed by thermal image analysis, they suggest that 'differential skin temperature (DST)1 be measured to detect the fertility interval in the menstrual cycle of a woman.

Research and Analysis of Image Processing Technologies Based on DotNet Framework

NASA Astrophysics Data System (ADS)

Ya-Lin, Song; Chen-Xi, Bai

Microsoft.Net is a kind of most popular program development tool. This paper gave a detailed analysis concluded about some image processing technologies of the advantages and disadvantages by .Net processed image while the same algorithm is used in Programming experiments. The result shows that the two best efficient methods are unsafe pointer and Direct 3D, and Direct 3D used to 3D simulation development, and the others are useful in some fields while these technologies are poor efficiency and not suited to real-time processing. The experiment results in paper will help some projects about image processing and simulation based DotNet and it has strong practicability.

Sub-10-ms X-ray tomography using a grating interferometer

NASA Astrophysics Data System (ADS)

Yashiro, Wataru; Noda, Daiji; Kajiwara, Kentaro

2017-05-01

An X-ray phase tomogram was successfully obtained with an exposure time of less than 10 ms by X-ray grating interferometry, an X-ray phase imaging technique that enables high-sensitivity X-ray imaging even of materials consisting of light elements. This high-speed X-ray imaging experiment was performed at BL28B2, SPring-8, where a white X-ray beam is available, and the tomogram was reconstructed from projection images recorded at a frame rate of 100,000 fps. The setup of the experiment will make it possible to realize three-dimensional observation of unrepeatable high-speed phenomena with a time resolution of less than 10 ms.

Body image and sexual orientation: The experiences of lesbian and bisexual women.

PubMed

Smith, Marie L; Telford, Elina; Tree, Jeremy J

2017-02-01

Western cultures promote a thin and curvaceous ideal body size that most women find difficult to achieve by healthy measures, resulting in poor body image and increased risk for eating pathology. Research focusing on body image in lesbian and bisexual women has yielded inconsistent results. In total, 11 lesbian and bisexual women were interviewed regarding their experiences with body image. Interpretative phenomenological analysis revealed that these women experienced similar mainstream pressures to conform to a thin body ideal. Furthermore, participants perceived additional pressure to conform to heteronormative standards of beauty since the normalisation of homosexuality and the increase in Lesbian, Gay, Bisexual and Transgender representation in mainstream media.

Fast live cell imaging at nanometer scale using annihilating filter-based low-rank Hankel matrix approach

NASA Astrophysics Data System (ADS)

Min, Junhong; Carlini, Lina; Unser, Michael; Manley, Suliana; Ye, Jong Chul

2015-09-01

Localization microscopy such as STORM/PALM can achieve a nanometer scale spatial resolution by iteratively localizing fluorescence molecules. It was shown that imaging of densely activated molecules can accelerate temporal resolution which was considered as major limitation of localization microscopy. However, this higher density imaging needs to incorporate advanced localization algorithms to deal with overlapping point spread functions (PSFs). In order to address this technical challenges, previously we developed a localization algorithm called FALCON1, 2 using a quasi-continuous localization model with sparsity prior on image space. It was demonstrated in both 2D/3D live cell imaging. However, it has several disadvantages to be further improved. Here, we proposed a new localization algorithm using annihilating filter-based low rank Hankel structured matrix approach (ALOHA). According to ALOHA principle, sparsity in image domain implies the existence of rank-deficient Hankel structured matrix in Fourier space. Thanks to this fundamental duality, our new algorithm can perform data-adaptive PSF estimation and deconvolution of Fourier spectrum, followed by truly grid-free localization using spectral estimation technique. Furthermore, all these optimizations are conducted on Fourier space only. We validated the performance of the new method with numerical experiments and live cell imaging experiment. The results confirmed that it has the higher localization performances in both experiments in terms of accuracy and detection rate.

Could This Be the Mars Soviet 3 Lander?

NASA Image and Video Library

2013-04-11

This set of images shows what might be hardware from the Soviet Union 1971 Mars 3 lander, seen in a pair of images from the High Resolution Imaging Science Experiment HiRISE camera on NASA Mars Reconnaissance Orbiter.

Oblique View of Victoria Crater

NASA Image and Video Library

2009-08-12

This image of Victoria Crater in the Meridiani Planum region of Mars was taken by the High Resolution Imaging Science Experiment HiRISE camera on NASA Mars Reconnaissance Orbiter at more of a sideways angle than earlier orbital images of this crater.

Image Quality Assessment of High-Resolution Satellite Images with Mtf-Based Fuzzy Comprehensive Evaluation Method

NASA Astrophysics Data System (ADS)

Wu, Z.; Luo, Z.; Zhang, Y.; Guo, F.; He, L.

2018-04-01

A Modulation Transfer Function (MTF)-based fuzzy comprehensive evaluation method was proposed in this paper for the purpose of evaluating high-resolution satellite image quality. To establish the factor set, two MTF features and seven radiant features were extracted from the knife-edge region of image patch, which included Nyquist, MTF0.5, entropy, peak signal to noise ratio (PSNR), average difference, edge intensity, average gradient, contrast and ground spatial distance (GSD). After analyzing the statistical distribution of above features, a fuzzy evaluation threshold table and fuzzy evaluation membership functions was established. The experiments for comprehensive quality assessment of different natural and artificial objects was done with GF2 image patches. The results showed that the calibration field image has the highest quality scores. The water image has closest image quality to the calibration field, quality of building image is a little poor than water image, but much higher than farmland image. In order to test the influence of different features on quality evaluation, the experiment with different weights were tested on GF2 and SPOT7 images. The results showed that different weights correspond different evaluating effectiveness. In the case of setting up the weights of edge features and GSD, the image quality of GF2 is better than SPOT7. However, when setting MTF and PSNR as main factor, the image quality of SPOT7 is better than GF2.

Quantum imaging with undetected photons.

PubMed

Lemos, Gabriela Barreto; Borish, Victoria; Cole, Garrett D; Ramelow, Sven; Lapkiewicz, Radek; Zeilinger, Anton

2014-08-28

Information is central to quantum mechanics. In particular, quantum interference occurs only if there exists no information to distinguish between the superposed states. The mere possibility of obtaining information that could distinguish between overlapping states inhibits quantum interference. Here we introduce and experimentally demonstrate a quantum imaging concept based on induced coherence without induced emission. Our experiment uses two separate down-conversion nonlinear crystals (numbered NL1 and NL2), each illuminated by the same pump laser, creating one pair of photons (denoted idler and signal). If the photon pair is created in NL1, one photon (the idler) passes through the object to be imaged and is overlapped with the idler amplitude created in NL2, its source thus being undefined. Interference of the signal amplitudes coming from the two crystals then reveals the image of the object. The photons that pass through the imaged object (idler photons from NL1) are never detected, while we obtain images exclusively with the signal photons (from NL1 and NL2), which do not interact with the object. Our experiment is fundamentally different from previous quantum imaging techniques, such as interaction-free imaging or ghost imaging, because now the photons used to illuminate the object do not have to be detected at all and no coincidence detection is necessary. This enables the probe wavelength to be chosen in a range for which suitable detectors are not available. To illustrate this, we show images of objects that are either opaque or invisible to the detected photons. Our experiment is a prototype in quantum information--knowledge can be extracted by, and about, a photon that is never detected.

Effectiveness of Global Features for Automatic Medical Image Classification and Retrieval – the experiences of OHSU at ImageCLEFmed

PubMed Central

Kalpathy-Cramer, Jayashree; Hersh, William

2008-01-01

In 2006 and 2007, Oregon Health & Science University (OHSU) participated in the automatic image annotation task for medical images at ImageCLEF, an annual international benchmarking event that is part of the Cross Language Evaluation Forum (CLEF). The goal of the automatic annotation task was to classify 1000 test images based on the Image Retrieval in Medical Applications (IRMA) code, given a set of 10,000 training images. There were 116 distinct classes in 2006 and 2007. We evaluated the efficacy of a variety of primarily global features for this classification task. These included features based on histograms, gray level correlation matrices and the gist technique. A multitude of classifiers including k-nearest neighbors, two-level neural networks, support vector machines, and maximum likelihood classifiers were evaluated. Our official error rates for the 1000 test images were 26% in 2006 using the flat classification structure. The error count in 2007 was 67.8 using the hierarchical classification error computation based on the IRMA code in 2007. Confusion matrices as well as clustering experiments were used to identify visually similar classes. The use of the IRMA code did not help us in the classification task as the semantic hierarchy of the IRMA classes did not correspond well with the hierarchy based on clustering of image features that we used. Our most frequent misclassification errors were along the view axis. Subsequent experiments based on a two-stage classification system decreased our error rate to 19.8% for the 2006 dataset and our error count to 55.4 for the 2007 data. PMID:19884953

Design and utilisation of protocols to characterise dynamic PET uptake of two tracers using basis pursuit.

PubMed

Bell, Christopher; Puttick, Simon; Rose, Stephen; Smith, Jye; Thomas, Paul; Dowson, Nicholas

2017-06-21

Imaging using more than one biological process using PET could be of great utility, but despite previously proposed approaches to dual-tracer imaging, it is seldom performed. The alternative of performing multiple scans is often infeasible for clinical practice or even in research studies. Dual-tracer PET scanning allows for multiple PET radiotracers to be imaged within the same imaging session. In this paper we describe our approach to utilise the basis pursuit method to aid in the design of dual-tracer PET imaging experiments, and later in separation of the signals. The advantage of this approach is that it does not require a compartment model architecture to be specified or even that both signals are distinguishable in all cases. This means the method for separating dual-tracer signals can be used for many feasible and useful combinations of biology or radiotracer, once an appropriate scanning protocol has been decided upon. Following a demonstration in separating the signals from two consecutively injected radionuclides in a controlled experiment, phantom and list-mode mouse experiments demonstrated the ability to test the feasibility of dual-tracer imaging protocols for multiple injection delays. Increases in variances predicted for kinetic macro-parameters V D and K I in brain and tumoral tissue were obtained when separating the synthetically combined data. These experiments confirmed previous work using other approaches that injections delays of 10-20 min ensured increases in variance were kept minimal for the test tracers used. On this basis, an actual dual-tracer experiment using a 20 min delay was performed using these radio tracers, with the kinetic parameters (V D and K I ) extracted for each tracer in agreement with the literature. This study supports previous work that dual-tracer PET imaging can be accomplished provided certain constraints are adhered to. The utilisation of basis pursuit techniques, with its removed need to specify a model architecture, allows the feasibility of a range of imaging protocols to be investigated via simulation in a straight-forward manner for a wide range of possible scenarios. The hope is that the ease of utilising this approach during feasibility studies and in practice removes any perceived technical barrier to performing dual-tracer imaging.

Design and utilisation of protocols to characterise dynamic PET uptake of two tracers using basis pursuit

NASA Astrophysics Data System (ADS)

Bell, Christopher; Puttick, Simon; Rose, Stephen; Smith, Jye; Thomas, Paul; Dowson, Nicholas

2017-06-01

Imaging using more than one biological process using PET could be of great utility, but despite previously proposed approaches to dual-tracer imaging, it is seldom performed. The alternative of performing multiple scans is often infeasible for clinical practice or even in research studies. Dual-tracer PET scanning allows for multiple PET radiotracers to be imaged within the same imaging session. In this paper we describe our approach to utilise the basis pursuit method to aid in the design of dual-tracer PET imaging experiments, and later in separation of the signals. The advantage of this approach is that it does not require a compartment model architecture to be specified or even that both signals are distinguishable in all cases. This means the method for separating dual-tracer signals can be used for many feasible and useful combinations of biology or radiotracer, once an appropriate scanning protocol has been decided upon. Following a demonstration in separating the signals from two consecutively injected radionuclides in a controlled experiment, phantom and list-mode mouse experiments demonstrated the ability to test the feasibility of dual-tracer imaging protocols for multiple injection delays. Increases in variances predicted for kinetic macro-parameters V D and K I in brain and tumoral tissue were obtained when separating the synthetically combined data. These experiments confirmed previous work using other approaches that injections delays of 10-20 min ensured increases in variance were kept minimal for the test tracers used. On this basis, an actual dual-tracer experiment using a 20 min delay was performed using these radio tracers, with the kinetic parameters (V D and K I) extracted for each tracer in agreement with the literature. This study supports previous work that dual-tracer PET imaging can be accomplished provided certain constraints are adhered to. The utilisation of basis pursuit techniques, with its removed need to specify a model architecture, allows the feasibility of a range of imaging protocols to be investigated via simulation in a straight-forward manner for a wide range of possible scenarios. The hope is that the ease of utilising this approach during feasibility studies and in practice removes any perceived technical barrier to performing dual-tracer imaging.

Body Image and Body Experience Disturbances in Schizophrenia: an Attempt to Introduce the Concept of Body Self as a Conceptual Framework.

PubMed

Sakson-Obada, Olga; Chudzikiewicz, Paulina; Pankowski, Daniel; Jarema, Marek

2018-01-01

Disturbances in body experience are described as key schizophrenia symptoms and early disease predictors. In case studies, different disorders relating to body experience are presented, but only a few empirical studies have aimed to distinguish the characteristics of body experience in schizophrenia, and these have been selected arbitrarily and without reference to cohesive theoretical model. To integrate this fragmentary approach, we propose a body self (BS) model, composed of: functions; representations (e.g., body image); and sense of body identity. The aim of the study was to determine whether the BS differentiates schizophrenic patients from healthy controls, and to investigate the relations between aspects of BS and a history of illness and clinical characteristics. The Body Self Questionnaire and the Positive and Negative Syndrome Scale were administered to 63 schizophrenic patients and 63 healthy subjects. The difference was found in the functions of the body-self (perceiving, interpreting, and regulating body experience), in the sense of body identity, and in one of three aspects of body image explored (e.g., acceptance of biological sex). Disturbances in BS were related to positive symptoms and to the number of hospitalizations for other diseases. Together, the results demonstrate that schizophrenia is more body experience than body image disorder, since the negative emotional attitude towards the body and acceptance of fitness were not distinctive for schizophrenia. The link between the disturbances in BS and the number of nonpsychiatric hospitalizations suggests that misinterpretation of body experiences in schizophrenia can promote a search for medical attention.

Dual-axis reflective continuous-wave terahertz confocal scanning polarization imaging and image fusion

NASA Astrophysics Data System (ADS)

Zhou, Yi; Li, Qi

2017-01-01

A dual-axis reflective continuous-wave terahertz (THz) confocal scanning polarization imaging system was adopted. THz polarization imaging experiments on gaps on film and metallic letters "BeLLE" were carried out. Imaging results indicate that the THz polarization imaging is sensitive to the tilted gap or wide flat gap, suggesting the THz polarization imaging is able to detect edges and stains. An image fusion method based on the digital image processing was proposed to ameliorate the imaging quality of metallic letters "BeLLE." Objective and subjective evaluation both prove that this method can improve the imaging quality.

Recognition of blurred images by the method of moments.

PubMed

Flusser, J; Suk, T; Saic, S

1996-01-01

The article is devoted to the feature-based recognition of blurred images acquired by a linear shift-invariant imaging system against an image database. The proposed approach consists of describing images by features that are invariant with respect to blur and recognizing images in the feature space. The PSF identification and image restoration are not required. A set of symmetric blur invariants based on image moments is introduced. A numerical experiment is presented to illustrate the utilization of the invariants for blurred image recognition. Robustness of the features is also briefly discussed.

Toward a Theoretical Model of Women's Body Image Resilience

ERIC Educational Resources Information Center

Choate, Laura Hensley

2005-01-01

This article discusses women's body image resilience. Body image dissatisfaction is prevalent among girls and women. Girls as young as 6 years old experience negative body image, and there is evidence that women struggle with body concerns throughout the life cycle (Lewis & Cachelin, 2001; Smolak, 2002; Striegel-Moore & Franko, 2002). In fact,…

Precise and Efficient Retrieval of Captioned Images: The MARIE Project.

ERIC Educational Resources Information Center

Rowe, Neil C.

1999-01-01

The MARIE project explores knowledge-based information retrieval of captioned images of the kind found in picture libraries and on the Internet. MARIE's five-part approach exploits the idea that images are easier to understand with context, especially descriptive text near them, but it also does image analysis. Experiments show MARIE prototypes…

The Evaluation of Students' Mental Images of Cigarette through Metaphor Analysis

ERIC Educational Resources Information Center

Gerçek, Cem

2017-01-01

Concepts change into mental images through individuals' experiences. Therefore, mental images can differ from culture to culture. This study aims to analyse students' mental images of cigarette through metaphors. This research uses phenomenology, one of qualitative research designs. The study group was composed of 986 secondary school, high school…

Computer-aided light sheet flow visualization using photogrammetry

NASA Technical Reports Server (NTRS)

Stacy, Kathryn; Severance, Kurt; Childers, Brooks A.

1994-01-01

A computer-aided flow visualization process has been developed to analyze video images acquired from rotating and translating light sheet visualization systems. The computer process integrates a mathematical model for image reconstruction, advanced computer graphics concepts, and digital image processing to provide a quantitative and a visual analysis capability. The image reconstruction model, based on photogrammetry, uses knowledge of the camera and light sheet locations and orientations to project two-dimensional light sheet video images into three-dimensional space. A sophisticated computer visualization package, commonly used to analyze computational fluid dynamics (CFD) results, was chosen to interactively display the reconstructed light sheet images with the numerical surface geometry for the model or aircraft under study. The photogrammetric reconstruction technique and the image processing and computer graphics techniques and equipment are described. Results of the computer-aided process applied to both a wind tunnel translating light sheet experiment and an in-flight rotating light sheet experiment are presented. The capability to compare reconstructed experimental light sheet images with CFD solutions in the same graphics environment is also demonstrated.

Computer-Aided Light Sheet Flow Visualization

NASA Technical Reports Server (NTRS)

Stacy, Kathryn; Severance, Kurt; Childers, Brooks A.

1993-01-01

A computer-aided flow visualization process has been developed to analyze video images acquired from rotating and translating light sheet visualization systems. The computer process integrates a mathematical model for image reconstruction, advanced computer graphics concepts, and digital image processing to provide a quantitative and visual analysis capability. The image reconstruction model, based on photogrammetry, uses knowledge of the camera and light sheet locations and orientations to project two-dimensional light sheet video images into three-dimensional space. A sophisticated computer visualization package, commonly used to analyze computational fluid dynamics (CFD) data sets, was chosen to interactively display the reconstructed light sheet images, along with the numerical surface geometry for the model or aircraft under study. A description is provided of the photogrammetric reconstruction technique, and the image processing and computer graphics techniques and equipment. Results of the computer aided process applied to both a wind tunnel translating light sheet experiment and an in-flight rotating light sheet experiment are presented. The capability to compare reconstructed experimental light sheet images and CFD solutions in the same graphics environment is also demonstrated.

IDEAL: Images Across Domains, Experiments, Algorithms and Learning

NASA Astrophysics Data System (ADS)

Ushizima, Daniela M.; Bale, Hrishikesh A.; Bethel, E. Wes; Ercius, Peter; Helms, Brett A.; Krishnan, Harinarayan; Grinberg, Lea T.; Haranczyk, Maciej; Macdowell, Alastair A.; Odziomek, Katarzyna; Parkinson, Dilworth Y.; Perciano, Talita; Ritchie, Robert O.; Yang, Chao

2016-11-01

Research across science domains is increasingly reliant on image-centric data. Software tools are in high demand to uncover relevant, but hidden, information in digital images, such as those coming from faster next generation high-throughput imaging platforms. The challenge is to analyze the data torrent generated by the advanced instruments efficiently, and provide insights such as measurements for decision-making. In this paper, we overview work performed by an interdisciplinary team of computational and materials scientists, aimed at designing software applications and coordinating research efforts connecting (1) emerging algorithms for dealing with large and complex datasets; (2) data analysis methods with emphasis in pattern recognition and machine learning; and (3) advances in evolving computer architectures. Engineering tools around these efforts accelerate the analyses of image-based recordings, improve reusability and reproducibility, scale scientific procedures by reducing time between experiments, increase efficiency, and open opportunities for more users of the imaging facilities. This paper describes our algorithms and software tools, showing results across image scales, demonstrating how our framework plays a role in improving image understanding for quality control of existent materials and discovery of new compounds.

Computer-aided light sheet flow visualization

NASA Technical Reports Server (NTRS)

Stacy, Kathryn; Severance, Kurt; Childers, Brooks A.

1993-01-01

A computer-aided flow visualization process has been developed to analyze video images acquired from rotating and translating light sheet visualization systems. The computer process integrates a mathematical model for image reconstruction, advanced computer graphics concepts, and digital image processing to provide a quantitative and visual analysis capability. The image reconstruction model, based on photogrammetry, uses knowledge of the camera and light sheet locations and orientations to project two-dimensional light sheet video images into three-dimensional space. A sophisticated computer visualization package, commonly used to analyze computational fluid dynamics (CFD) data sets, was chosen to interactively display the reconstructed light sheet images, along with the numerical surface geometry for the model or aircraft under study. A description is provided of the photogrammetric reconstruction technique, and the image processing and computer graphics techniques and equipment. Results of the computer aided process applied to both a wind tunnel translating light sheet experiment and an in-flight rotating light sheet experiment are presented. The capability to compare reconstructed experimental light sheet images and CFD solutions in the same graphics environment is also demonstrated.

Intrinsic motivations drive learning of eye movements: an experiment with human adults.

PubMed

Caligiore, Daniele; Mustile, Magda; Cipriani, Daniele; Redgrave, Peter; Triesch, Jochen; De Marsico, Maria; Baldassarre, Gianluca

2015-01-01

Intrinsic motivations drive the acquisition of knowledge and skills on the basis of novel or surprising stimuli or the pleasure to learn new skills. In so doing, they are different from extrinsic motivations that are mainly linked to drives that promote survival and reproduction. Intrinsic motivations have been implicitly exploited in several psychological experiments but, due to the lack of proper paradigms, they are rarely a direct subject of investigation. This article investigates how different intrinsic motivation mechanisms can support the learning of visual skills, such as "foveate a particular object in space", using a gaze contingency paradigm. In the experiment participants could freely foveate objects shown in a computer screen. Foveating each of two "button" pictures caused different effects: one caused the appearance of a simple image (blue rectangle) in unexpected positions, while the other evoked the appearance of an always-novel picture (objects or animals). The experiment studied how two possible intrinsic motivation mechanisms might guide learning to foveate one or the other button picture. One mechanism is based on the sudden, surprising appearance of a familiar image at unpredicted locations, and a second one is based on the content novelty of the images. The results show the comparative effectiveness of the mechanism based on image novelty, whereas they do not support the operation of the mechanism based on the surprising location of the image appearance. Interestingly, these results were also obtained with participants that, according to a post experiment questionnaire, had not understood the functions of the different buttons suggesting that novelty-based intrinsic motivation mechanisms might operate even at an unconscious level.

syris: a flexible and efficient framework for X-ray imaging experiments simulation.

PubMed

Faragó, Tomáš; Mikulík, Petr; Ershov, Alexey; Vogelgesang, Matthias; Hänschke, Daniel; Baumbach, Tilo

2017-11-01

An open-source framework for conducting a broad range of virtual X-ray imaging experiments, syris, is presented. The simulated wavefield created by a source propagates through an arbitrary number of objects until it reaches a detector. The objects in the light path and the source are time-dependent, which enables simulations of dynamic experiments, e.g. four-dimensional time-resolved tomography and laminography. The high-level interface of syris is written in Python and its modularity makes the framework very flexible. The computationally demanding parts behind this interface are implemented in OpenCL, which enables fast calculations on modern graphics processing units. The combination of flexibility and speed opens new possibilities for studying novel imaging methods and systematic search of optimal combinations of measurement conditions and data processing parameters. This can help to increase the success rates and efficiency of valuable synchrotron beam time. To demonstrate the capabilities of the framework, various experiments have been simulated and compared with real data. To show the use case of measurement and data processing parameter optimization based on simulation, a virtual counterpart of a high-speed radiography experiment was created and the simulated data were used to select a suitable motion estimation algorithm; one of its parameters was optimized in order to achieve the best motion estimation accuracy when applied on the real data. syris was also used to simulate tomographic data sets under various imaging conditions which impact the tomographic reconstruction accuracy, and it is shown how the accuracy may guide the selection of imaging conditions for particular use cases.

The role of figure-ground segregation in change blindness.

PubMed

Landman, Rogier; Spekreijse, Henk; Lamme, Victor A F

2004-04-01

Partial report methods have shown that a large-capacity representation exists for a few hundred milliseconds after a picture has disappeared. However, change blindness studies indicate that very limited information remains available when a changed version of the image is presented subsequently. What happens to the large-capacity representation? New input after the first image may interfere, but this is likely to depend on the characteristics of the new input. In our first experiment, we show that a display containing homogeneous image elements between changing images does not render the large-capacity representation unavailable. Interference occurs when these new elements define objects. On that basis we introduce a new method to produce change blindness: The second experiment shows that change blindness can be induced by redefining figure and background, without an interval between the displays. The local features (line segments) that defined figures and background were swapped, while the contours of the figures remained where they were. Normally, changes are easily detected when there is no interval. However, our paradigm results in massive change blindness. We propose that in a change blindness experiment, there is a large-capacity representation of the original image when it is followed by a homogeneous interval display, but that change blindness occurs whenever the changed image forces resegregation of figures from the background.

Local multifractal detrended fluctuation analysis for non-stationary image's texture segmentation

NASA Astrophysics Data System (ADS)

Wang, Fang; Li, Zong-shou; Li, Jin-wei

2014-12-01

Feature extraction plays a great important role in image processing and pattern recognition. As a power tool, multifractal theory is recently employed for this job. However, traditional multifractal methods are proposed to analyze the objects with stationary measure and cannot for non-stationary measure. The works of this paper is twofold. First, the definition of stationary image and 2D image feature detection methods are proposed. Second, a novel feature extraction scheme for non-stationary image is proposed by local multifractal detrended fluctuation analysis (Local MF-DFA), which is based on 2D MF-DFA. A set of new multifractal descriptors, called local generalized Hurst exponent (Lhq) is defined to characterize the local scaling properties of textures. To test the proposed method, both the novel texture descriptor and other two multifractal indicators, namely, local Hölder coefficients based on capacity measure and multifractal dimension Dq based on multifractal differential box-counting (MDBC) method, are compared in segmentation experiments. The first experiment indicates that the segmentation results obtained by the proposed Lhq are better than the MDBC-based Dq slightly and superior to the local Hölder coefficients significantly. The results in the second experiment demonstrate that the Lhq can distinguish the texture images more effectively and provide more robust segmentations than the MDBC-based Dq significantly.

Neuropsychological Evidence for Visual- and Motor-Based Affordance: Effects of Reference Frame and Object-Hand Congruence

ERIC Educational Resources Information Center

Humphreys, Glyn W.; Wulff, Melanie; Yoon, Eun Young; Riddoch, M. Jane

2010-01-01

Two experiments are reported that use patients with visual extinction to examine how visual attention is influenced by action information in images. In Experiment 1 patients saw images of objects that were either correctly or incorrectly colocated for action, with the objects held by hands that were congruent or incongruent with those used…

Determination of Surface Tension of Surfactant Solutions through Capillary Rise Measurements: An Image-Processing Undergraduate Laboratory Experiment

ERIC Educational Resources Information Center

Huck-Iriart, Cristia´n; De-Candia, Ariel; Rodriguez, Javier; Rinaldi, Carlos

2016-01-01

In this work, we described an image processing procedure for the measurement of surface tension of the air-liquid interface using isothermal capillary action. The experiment, designed for an undergraduate course, is based on the analysis of a series of solutions with diverse surfactant concentrations at different ionic strengths. The objective of…

PDSS/IMC CIS user's guide

NASA Technical Reports Server (NTRS)

1984-01-01

The Spacelab Payload Development Support System PDSS Image Motion Compensator (IMC) computer interface simulation (CIS) user's manual is given. The software provides a real time interface simulation for the following IMC subsystems: the Dry Rotor Reference Unit, the Advanced Star/Target Reference Optical sensor, the Ultra Violet imaging telescope, the Wisconson Ultraviolet Photopolarimetry Experiment, the Cruciform Power distributor, and the Spacelab Experiment Computer Operating System.

Hyperspectral imaging of skin and lung cancers

NASA Astrophysics Data System (ADS)

Zherdeva, Larisa A.; Bratchenko, Ivan A.; Alonova, Marina V.; Myakinin, Oleg O.; Artemyev, Dmitry N.; Moryatov, Alexander A.; Kozlov, Sergey V.; Zakharov, Valery P.

2016-04-01

The problem of cancer control requires design of new approaches for instrumental diagnostics, as the accuracy of cancer detection on the first step of diagnostics in clinics is slightly more than 50%. In this study, we present a method of visualization and diagnostics of skin and lung tumours based on registration and processing of tissues hyperspectral images. In a series of experiments registration of hyperspectral images of skin and lung tissue samples is carried out. Melanoma, basal cell carcinoma, nevi and benign tumours are studied in skin ex vivo and in vivo experiments; adenocarcinomas and squamous cell carcinomas are studied in ex vivo lung experiments. In a series of experiments the typical features of diffuse reflection spectra for pathological and normal tissues were found. Changes in tissues morphology during the tumour growth lead to the changes of blood and pigments concentration, such as melanin in skin. That is why tumours and normal tissues maybe differentiated with information about spectral response in 500-600 nm and 600 - 670 nm areas. Thus, hyperspectral imaging in the visible region may be a useful tool for cancer detection as it helps to estimate spectral properties of tissues and determine malignant regions for precise resection of tumours.

Particle image velocimetry for the Surface Tension Driven Convection Experiment using a particle displacement tracking technique

NASA Technical Reports Server (NTRS)

Wernet, Mark P.; Pline, Alexander D.

1991-01-01

The Surface Tension Driven Convection Experiment (STDCE) is a Space Transportation System flight experiment to study both transient and steady thermocapillary fluid flows aboard the USML-1 Spacelab mission planned for 1992. One of the components of data collected during the experiment is a video record of the flow field. This qualitative data is then quantified using an all electronic, two-dimensional particle image velocimetry technique called particle displacement tracking (PDT) which uses a simple space domain particle tracking algorithm. The PDT system is successful in producing velocity vector fields from the raw video data. Application of the PDT technique to a sample data set yielded 1606 vectors in 30 seconds of processing time. A bottom viewing optical arrangement is used to image the illuminated plane, which causes keystone distortion in the final recorded image. A coordinate transformation was incorporated into the system software to correct this viewing angle distortion. PDT processing produced 1.8 percent false identifications, due to random particle locations. A highly successful routine for removing the false identifications was also incorporated, reducing the number of false identifications to 0.2 percent.

Particle image velocimetry for the surface tension driven convection experiment using a particle displacement tracking technique

NASA Technical Reports Server (NTRS)

Wernet, Mark P.; Pline, Alexander D.

1991-01-01

The Surface Tension Driven Convection Experiment (STDCE) is a Space Transportation System flight experiment to study both transient and steady thermocapillary fluid flows aboard the USML-1 Spacelab mission planned for 1992. One of the components of data collected during the experiment is a video record of the flow field. This qualitative data is then quantified using an all electronic, two-dimensional particle image velocimetry technique called particle displacement tracking (PDT) which uses a simple space domain particle tracking algorithm. The PDT system is successful in producing velocity vector fields from the raw video data. Application of the PDT technique to a sample data set yielded 1606 vectors in 30 seconds of processing time. A bottom viewing optical arrangement is used to image the illuminated plane, which causes keystone distortion in the final recorded image. A coordinate transformation was incorporated into the system software to correct this viewing angle distortion. PDT processing produced 1.8 percent false identifications, due to random particle locations. A highly successful routine for removing the false identifications was also incorporated, reducing the number of false identifications to 0.2 percent.

Topological charge number multiplexing for JTC multiple-image encryption

NASA Astrophysics Data System (ADS)

Chen, Qi; Shen, Xueju; Dou, Shuaifeng; Lin, Chao; Wang, Long

2018-04-01

We propose a method of topological charge number multiplexing based on the JTC encryption system to achieve multiple-image encryption. Using this method, multi-image can be encrypted into single ciphertext, and the original images can be recovered according to the authority level. The number of encrypted images is increased, moreover, the quality of decrypted images is improved. Results of computer simulation and initial experiment identify the validity of our proposed method.

Full-Frame Reference for Test Photo of Moon

NASA Image and Video Library

2005-09-10

This pair of views shows how little of the full image frame was taken up by the Moon in test images taken Sept. 8, 2005, by the High Resolution Imaging Science Experiment HiRISE camera on NASA Mars Reconnaissance Orbiter.

Cascade classification of endocytoscopic images of colorectal lesions for automated pathological diagnosis

NASA Astrophysics Data System (ADS)

Itoh, Hayato; Mori, Yuichi; Misawa, Masashi; Oda, Masahiro; Kudo, Shin-ei; Mori, Kensaku

2018-02-01

This paper presents a new classification method for endocytoscopic images. Endocytoscopy is a new endoscope that enables us to perform conventional endoscopic observation and ultramagnified observation of cell level. This ultramagnified views (endocytoscopic images) make possible to perform pathological diagnosis only on endo-scopic views of polyps during colonoscopy. However, endocytoscopic image diagnosis requires higher experiences for physicians. An automated pathological diagnosis system is required to prevent the overlooking of neoplastic lesions in endocytoscopy. For this purpose, we propose a new automated endocytoscopic image classification method that classifies neoplastic and non-neoplastic endocytoscopic images. This method consists of two classification steps. At the first step, we classify an input image by support vector machine. We forward the image to the second step if the confidence of the first classification is low. At the second step, we classify the forwarded image by convolutional neural network. We reject the input image if the confidence of the second classification is also low. We experimentally evaluate the classification performance of the proposed method. In this experiment, we use about 16,000 and 4,000 colorectal endocytoscopic images as training and test data, respectively. The results show that the proposed method achieves high sensitivity 93.4% with small rejection rate 9.3% even for difficult test data.

Transcranial phase aberration correction using beam simulations and MR-ARFI

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vyas, Urvi, E-mail: urvi.vyas@gmail.com; Kaye, Elena; Pauly, Kim Butts

2014-03-15

Purpose: Transcranial magnetic resonance-guided focused ultrasound surgery is a noninvasive technique for causing selective tissue necrosis. Variations in density, thickness, and shape of the skull cause aberrations in the location and shape of the focal zone. In this paper, the authors propose a hybrid simulation-MR-ARFI technique to achieve aberration correction for transcranial MR-guided focused ultrasound surgery. The technique uses ultrasound beam propagation simulations with MR Acoustic Radiation Force Imaging (MR-ARFI) to correct skull-caused phase aberrations. Methods: Skull-based numerical aberrations were obtained from a MR-guided focused ultrasound patient treatment and were added to all elements of the InSightec conformal bone focusedmore » ultrasound surgery transducer during transmission. In the first experiment, the 1024 aberrations derived from a human skull were condensed into 16 aberrations by averaging over the transducer area of 64 elements. In the second experiment, all 1024 aberrations were applied to the transducer. The aberrated MR-ARFI images were used in the hybrid simulation-MR-ARFI technique to find 16 estimated aberrations. These estimated aberrations were subtracted from the original aberrations to result in the corrected images. Each aberration experiment (16-aberration and 1024-aberration) was repeated three times. Results: The corrected MR-ARFI image was compared to the aberrated image and the ideal image (image with zero aberrations) for each experiment. The hybrid simulation-MR-ARFI technique resulted in an average increase in focal MR-ARFI phase of 44% for the 16-aberration case and 52% for the 1024-aberration case, and recovered 83% and 39% of the ideal MR-ARFI phase for the 16-aberrations and 1024-aberration case, respectively. Conclusions: Using one MR-ARFI image and noa priori information about the applied phase aberrations, the hybrid simulation-MR-ARFI technique improved the maximum MR-ARFI phase of the beam's focus.« less

A Unified Steganalysis Framework

DTIC Science & Technology

2013-04-01

contains more than 1800 images of different scenes. In the experiments, we used four JPEG based steganography techniques: Out- guess [13], F5 [16], model...also compressed these images again since some of the steganography meth- ods are double compressing the images . Stego- images are generated by embedding...randomly chosen messages (in bits) into 1600 grayscale images using each of the four steganography techniques. A random message length was determined

Visualizing 3D Objects from 2D Cross Sectional Images Displayed "In-Situ" versus "Ex-Situ"

ERIC Educational Resources Information Center

Wu, Bing; Klatzky, Roberta L.; Stetten, George

2010-01-01

The present research investigates how mental visualization of a 3D object from 2D cross sectional images is influenced by displacing the images from the source object, as is customary in medical imaging. Three experiments were conducted to assess people's ability to integrate spatial information over a series of cross sectional images in order to…

Translating statistical images to text summaries for partially sighted persons on mobile devices: iconic image maps approach

NASA Astrophysics Data System (ADS)

Williams, Godfried B.

2005-03-01

This paper attempts to demonstrate a novel based idea for transforming statistical image data to text using autoassociative and unsupervised artificial neural network and iconic image maps using the shape and texture genetic algorithm, underlying concepts translating the image data to text. Full details of experiments could be assessed at http://www.uel.ac.uk/seis/applications/.

The application of similar image retrieval in electronic commerce.

PubMed

Hu, YuPing; Yin, Hua; Han, Dezhi; Yu, Fei

2014-01-01

Traditional online shopping platform (OSP), which searches product information by keywords, faces three problems: indirect search mode, large search space, and inaccuracy in search results. For solving these problems, we discuss and research the application of similar image retrieval in electronic commerce. Aiming at improving the network customers' experience and providing merchants with the accuracy of advertising, we design a reasonable and extensive electronic commerce application system, which includes three subsystems: image search display subsystem, image search subsystem, and product information collecting subsystem. This system can provide seamless connection between information platform and OSP, on which consumers can automatically and directly search similar images according to the pictures from information platform. At the same time, it can be used to provide accuracy of internet marketing for enterprises. The experiment shows the efficiency of constructing the system.

The Application of Similar Image Retrieval in Electronic Commerce

PubMed Central

Hu, YuPing; Yin, Hua; Han, Dezhi; Yu, Fei

2014-01-01

Traditional online shopping platform (OSP), which searches product information by keywords, faces three problems: indirect search mode, large search space, and inaccuracy in search results. For solving these problems, we discuss and research the application of similar image retrieval in electronic commerce. Aiming at improving the network customers' experience and providing merchants with the accuracy of advertising, we design a reasonable and extensive electronic commerce application system, which includes three subsystems: image search display subsystem, image search subsystem, and product information collecting subsystem. This system can provide seamless connection between information platform and OSP, on which consumers can automatically and directly search similar images according to the pictures from information platform. At the same time, it can be used to provide accuracy of internet marketing for enterprises. The experiment shows the efficiency of constructing the system. PMID:24883411

Visual improvement for bad handwriting based on Monte-Carlo method

NASA Astrophysics Data System (ADS)

Shi, Cao; Xiao, Jianguo; Xu, Canhui; Jia, Wenhua

2014-03-01

A visual improvement algorithm based on Monte Carlo simulation is proposed in this paper, in order to enhance visual effects for bad handwriting. The whole improvement process is to use well designed typeface so as to optimize bad handwriting image. In this process, a series of linear operators for image transformation are defined for transforming typeface image to approach handwriting image. And specific parameters of linear operators are estimated by Monte Carlo method. Visual improvement experiments illustrate that the proposed algorithm can effectively enhance visual effect for handwriting image as well as maintain the original handwriting features, such as tilt, stroke order and drawing direction etc. The proposed visual improvement algorithm, in this paper, has a huge potential to be applied in tablet computer and Mobile Internet, in order to improve user experience on handwriting.

Infrared Imaging of Boundary Layer Transition Flight Experiments

NASA Technical Reports Server (NTRS)

Berry, Scott A.; Horvath, Thomas J., Jr.; Schwartz, Richard; Ross, Martin; Anderson, Brian; Campbell, Charles H.

2008-01-01

The Hypersonic Thermodynamic Infrared Measurement (HYTHIRM) project is presently focused on near term support to the Shuttle program through the development of an infrared imaging capability of sufficient spatial and temporal resolution to augment existing on-board Orbiter instrumentation. Significant progress has been made with the identification and inventory of relevant existing optical imaging assets and the development, maturation, and validation of simulation and modeling tools for assessment and mission planning purposes, which were intended to lead to the best strategies and assets for successful acquisition of quantitative global surface temperature data on the Shuttle during entry. However, there are longer-term goals of providing global infrared imaging support to other flight projects as well. A status of HYTHIRM from the perspective of how two NASA-sponsored boundary layer transition flight experiments could benefit by infrared measurements is provided. Those two flight projects are the Hypersonic Boundary layer Transition (HyBoLT) flight experiment and the Shuttle Boundary Layer Transition Flight Experiment (BLT FE), which are both intended for reducing uncertainties associated with the extrapolation of wind tunnel derived transition correlations for flight application. Thus, the criticality of obtaining high quality flight data along with the impact it would provide to the Shuttle program damage assessment process are discussed. Two recent wind tunnel efforts that were intended as risk mitigation in terms of quantifying the transition process and resulting turbulent wedge locations are briefly reviewed. Progress is being made towards finalizing an imaging strategy in support of the Shuttle BLT FE, however there are no plans currently to image HyBoLT.

Effects of self-directed and other-directed introspection and emotional valence on activation of the rostral prefrontal cortex during aesthetic experience.

PubMed

Kreplin, Ute; Fairclough, Stephen H

2015-05-01

The medial area of the rostral prefrontal cortex (rPFC) has been implicated in self-relevant processing, autobiographical memory and emotional processing, including the processing of pleasure during aesthetic experiences. The goal of this study was to investigate changes in rPFC activity using functional near-infrared spectroscopy (fNIRS) in response to affective stimuli viewed in a self-relevant or other-relevant context. Positive and negative images were displayed to 20 participants under two viewing conditions where participants were asked to think of their own emotions (self) or think about the emotions of the artist who created the work (other). The results revealed an increase of HbO when participants viewed images during the other-condition compared to the self-condition. It was concluded that viewing stimuli from the perspective of another was associated with an increase of cognitive demand. The analysis of deoxygenated haemoglobin (HHb) at right hemispheric areas revealed that activation of the rPFC during the other-condition was specific to the negative images. When images were viewed from the perspective of the self, activation of the rPFC significantly increased at the right-medial area of the rPFC for positive images. Our findings indicate that the influence of valence on rPFC activation during aesthetic experience is contingent on the context of the viewing experience and there is a bias towards positive emotion when images are viewed from the context of the self. Copyright © 2015 Elsevier Ltd. All rights reserved.

Final design of the Energy-Resolved Neutron Imaging System “RADEN” at J-PARC

NASA Astrophysics Data System (ADS)

Shinohara, T.; Kai, T.; Oikawa, K.; Segawa, M.; Harada, M.; Nakatani, T.; Ooi, M.; Aizawa, K.; Sato, H.; Kamiyama, T.; Yokota, H.; Sera, T.; Mochiki, K.; Kiyanagi, Y.

2016-09-01

A new pulsed-neutron instrument, named the Energy-Resolved Neutron Imaging System “RADEN”, has been constructed at the beam line of BL22 in the Materials and Life Science Experimental Facility (MLF) of J-PARC. The primary purpose of this instrument is to perform energy-resolved neutron imaging experiments through the effective utilization of the pulsed nature of the neutron beam, making this the world's first instrument dedicated to pulsed neutron imaging experiments. RADEN was designed to cover a broad energy range: from cold neutrons with energy down to 1.05 meV (or wavelength up to 8.8 Å) with a good wavelength resolution of 0.20% to high-energy neutrons with energy of several tens keV (or wavelength of 10-3 Å). In addition, this instrument is intended to perform state-of-the-art neutron radiography and tomography experiments in Japan. Hence, a maximum beam size of 300 mm square and a high L/D value of up to 7500 are provided.

Creating an Immersive Mars Experience Using Unity3D

NASA Technical Reports Server (NTRS)

Miles, Sarah

2011-01-01

Between the two Mars Exploration Rovers, Spirit and Opportunity, NASA has collected over 280,000 images while studying the Martian surface. This number will continue to grow, with Opportunity continuing to send images and with another rover, Curiosity, launching soon. Using data collected by and for these Mars rovers, I am contributing to the creation of virtual experiences that will expose the general public to Mars. These experiences not only work to increase public knowledge, but they attempt to do so in an engaging manner more conducive to knowledge retention by letting others view Mars through the rovers' eyes. My contributions include supporting image viewing (for example, allowing users to click on panoramic images of the Martian surface to access closer range photos) as well as enabling tagging of points of interest. By creating a more interactive way of viewing the information we have about Mars, we are not just educating the public about a neighboring planet. We are showing the importance of doing such research.

Mapping Antiretroviral Drugs in Tissue by IR-MALDESI MSI Coupled to the Q Exactive and Comparison with LC-MS/MS SRM Assay

NASA Astrophysics Data System (ADS)

Barry, Jeremy A.; Robichaud, Guillaume; Bokhart, Mark T.; Thompson, Corbin; Sykes, Craig; Kashuba, Angela D. M.; Muddiman, David C.

2014-12-01

This work describes the coupling of the IR-MALDESI imaging source with the Q Exactive mass spectrometer. IR-MALDESI MSI was used to elucidate the spatial distribution of several HIV drugs in cervical tissues that had been incubated in either a low or high concentration. Serial sections of those analyzed by IR-MALDESI MSI were homogenized and analyzed by LC-MS/MS to quantify the amount of each drug present in the tissue. By comparing the two techniques, an agreement between the average intensities from the imaging experiment and the absolute quantities for each drug was observed. This correlation between these two techniques serves as a prerequisite to quantitative IR-MALDESI MSI. In addition, a targeted MS2 imaging experiment was also conducted to demonstrate the capabilities of the Q Exactive and to highlight the added selectivity that can be obtained with SRM or MRM imaging experiments.

Results and experiences from the NATO Common Shield DAT#7 experiment for the Defence Against Terrorism program

NASA Astrophysics Data System (ADS)

Peichl, Markus; Dill, Stephan; Jirousek, Matthias; Süß, Helmut

2009-05-01

Passive microwave imaging allows a daytime independent observation and examination of objects and persons without artificial exposure under nearly all weather conditions. The penetration capability of microwaves allows the detection of hidden objects like weapons and explosive devices under the clothing. In August/September 2008 a comprehensive military experiment was conducted by the German armed forces at the naval base Eckernfoerde, Germany. One activity in the Eckernfoerde trial was the simulation of a military entrance portal by a tent including various imaging and a chemical sensor suite. Besides commercial optical and infrared cameras various passive millimeter-wave imagers have been used from different German research institutions. The DLR Microwaves and Radar Institute, Department for Reconnaissance and Security (HR-AS), provided an imaging radiometer scanner operating at W band. A multitude of situations have been simulated and many persons carrying hidden objects under their clothing have been scanned. Some exemplary results from the trial are shown and discussed in the paper.

A Validation Approach for Quasistatic Numerical/Experimental Indentation Analysis in Soft Materials Using 3D Digital Image Correlation.

PubMed

Felipe-Sesé, Luis; López-Alba, Elías; Hannemann, Benedikt; Schmeer, Sebastian; Diaz, Francisco A

2017-06-28

A quasistatic indentation numerical analysis in a round section specimen made of soft material has been performed and validated with a full field experimental technique, i.e., Digital Image Correlation 3D. The contact experiment specifically consisted of loading a 25 mm diameter rubber cylinder of up to a 5 mm indentation and then unloading. Experimental strains fields measured at the surface of the specimen during the experiment were compared with those obtained by performing two numerical analyses employing two different hyperplastic material models. The comparison was performed using an Image Decomposition new methodology that makes a direct comparison of full-field data independently of their scale or orientation possible. Numerical results show a good level of agreement with those measured during the experiments. However, since image decomposition allows for the differences to be quantified, it was observed that one of the adopted material models reproduces lower differences compared to experimental results.

A Validation Approach for Quasistatic Numerical/Experimental Indentation Analysis in Soft Materials Using 3D Digital Image Correlation

PubMed Central

Felipe-Sesé, Luis; López-Alba, Elías; Hannemann, Benedikt; Schmeer, Sebastian; Diaz, Francisco A.

2017-01-01

A quasistatic indentation numerical analysis in a round section specimen made of soft material has been performed and validated with a full field experimental technique, i.e., Digital Image Correlation 3D. The contact experiment specifically consisted of loading a 25 mm diameter rubber cylinder of up to a 5 mm indentation and then unloading. Experimental strains fields measured at the surface of the specimen during the experiment were compared with those obtained by performing two numerical analyses employing two different hyperplastic material models. The comparison was performed using an Image Decomposition new methodology that makes a direct comparison of full-field data independently of their scale or orientation possible. Numerical results show a good level of agreement with those measured during the experiments. However, since image decomposition allows for the differences to be quantified, it was observed that one of the adopted material models reproduces lower differences compared to experimental results. PMID:28773081

Similarity analysis between quantum images

NASA Astrophysics Data System (ADS)

Zhou, Ri-Gui; Liu, XingAo; Zhu, Changming; Wei, Lai; Zhang, Xiafen; Ian, Hou

2018-06-01

Similarity analyses between quantum images are so essential in quantum image processing that it provides fundamental research for the other fields, such as quantum image matching, quantum pattern recognition. In this paper, a quantum scheme based on a novel quantum image representation and quantum amplitude amplification algorithm is proposed. At the end of the paper, three examples and simulation experiments show that the measurement result must be 0 when two images are same, and the measurement result has high probability of being 1 when two images are different.

Multi-Pixel Simultaneous Classification of PolSAR Image Using Convolutional Neural Networks

PubMed Central

Xu, Xin; Gui, Rong; Pu, Fangling

2018-01-01

Convolutional neural networks (CNN) have achieved great success in the optical image processing field. Because of the excellent performance of CNN, more and more methods based on CNN are applied to polarimetric synthetic aperture radar (PolSAR) image classification. Most CNN-based PolSAR image classification methods can only classify one pixel each time. Because all the pixels of a PolSAR image are classified independently, the inherent interrelation of different land covers is ignored. We use a fixed-feature-size CNN (FFS-CNN) to classify all pixels in a patch simultaneously. The proposed method has several advantages. First, FFS-CNN can classify all the pixels in a small patch simultaneously. When classifying a whole PolSAR image, it is faster than common CNNs. Second, FFS-CNN is trained to learn the interrelation of different land covers in a patch, so it can use the interrelation of land covers to improve the classification results. The experiments of FFS-CNN are evaluated on a Chinese Gaofen-3 PolSAR image and other two real PolSAR images. Experiment results show that FFS-CNN is comparable with the state-of-the-art PolSAR image classification methods. PMID:29510499

Human pose tracking from monocular video by traversing an image motion mapped body pose manifold

NASA Astrophysics Data System (ADS)

Basu, Saurav; Poulin, Joshua; Acton, Scott T.

2010-01-01

Tracking human pose from monocular video sequences is a challenging problem due to the large number of independent parameters affecting image appearance and nonlinear relationships between generating parameters and the resultant images. Unlike the current practice of fitting interpolation functions to point correspondences between underlying pose parameters and image appearance, we exploit the relationship between pose parameters and image motion flow vectors in a physically meaningful way. Change in image appearance due to pose change is realized as navigating a low dimensional submanifold of the infinite dimensional Lie group of diffeomorphisms of the two dimensional sphere S2. For small changes in pose, image motion flow vectors lie on the tangent space of the submanifold. Any observed image motion flow vector field is decomposed into the basis motion vector flow fields on the tangent space and combination weights are used to update corresponding pose changes in the different dimensions of the pose parameter space. Image motion flow vectors are largely invariant to style changes in experiments with synthetic and real data where the subjects exhibit variation in appearance and clothing. The experiments demonstrate the robustness of our method (within +/-4° of ground truth) to style variance.

Research on the principle and experimentation of optical compressive spectral imaging

NASA Astrophysics Data System (ADS)

Chen, Yuheng; Chen, Xinhua; Zhou, Jiankang; Ji, Yiqun; Shen, Weimin

2013-12-01

The optical compressive spectral imaging method is a novel spectral imaging technique that draws in the inspiration of compressed sensing, which takes on the advantages such as reducing acquisition data amount, realizing snapshot imaging, increasing signal to noise ratio and so on. Considering the influence of the sampling quality on the ultimate imaging quality, researchers match the sampling interval with the modulation interval in former reported imaging system, while the depressed sampling rate leads to the loss on the original spectral resolution. To overcome that technical defect, the demand for the matching between the sampling interval and the modulation interval is disposed of and the spectral channel number of the designed experimental device increases more than threefold comparing to that of the previous method. Imaging experiment is carried out by use of the experiment installation and the spectral data cube of the shooting target is reconstructed with the acquired compressed image by use of the two-step iterative shrinkage/thresholding algorithms. The experimental result indicates that the spectral channel number increases effectively and the reconstructed data stays high-fidelity. The images and spectral curves are able to accurately reflect the spatial and spectral character of the target.

Multi-Pixel Simultaneous Classification of PolSAR Image Using Convolutional Neural Networks.

PubMed

Wang, Lei; Xu, Xin; Dong, Hao; Gui, Rong; Pu, Fangling

2018-03-03

Convolutional neural networks (CNN) have achieved great success in the optical image processing field. Because of the excellent performance of CNN, more and more methods based on CNN are applied to polarimetric synthetic aperture radar (PolSAR) image classification. Most CNN-based PolSAR image classification methods can only classify one pixel each time. Because all the pixels of a PolSAR image are classified independently, the inherent interrelation of different land covers is ignored. We use a fixed-feature-size CNN (FFS-CNN) to classify all pixels in a patch simultaneously. The proposed method has several advantages. First, FFS-CNN can classify all the pixels in a small patch simultaneously. When classifying a whole PolSAR image, it is faster than common CNNs. Second, FFS-CNN is trained to learn the interrelation of different land covers in a patch, so it can use the interrelation of land covers to improve the classification results. The experiments of FFS-CNN are evaluated on a Chinese Gaofen-3 PolSAR image and other two real PolSAR images. Experiment results show that FFS-CNN is comparable with the state-of-the-art PolSAR image classification methods.

It’s Not Just a “Woman Thing:” The Current State of Normative Discontent

PubMed Central

TANTLEFF-DUNN, STACEY; BARNES, RACHEL D.; LAROSE, JESSICA GOKEE

2013-01-01

This study assessed “normative discontent,” the concept that most women experience weight dissatisfaction, as an emerging societal stereotype for women and men (Rodin, Silberstein, & Streigel-Moore, 1984). Participants (N = 472) completed measures of stereotypes, eating disorders, and body image. Normative discontent stereotypes were pervasive for women and men. Endorsing stereotypes varied by sex and participants’ own disturbance, with trends towards eating disorder symptomotology being positively correlated with stereotype endorsement. Individuals with higher levels of body image and eating disturbance may normalize their behavior by perceiving that most people share their experiences. Future research needs to test prevention and intervention strategies that incorporate the discrepancies between body image/eating-related stereotypes and reality with focus on preventing normalization of such experiences. PMID:21932970

Rover Soil Experiments Near Yogi

NASA Technical Reports Server (NTRS)

1997-01-01

Sojourner, while on its way to the rock Yogi, performed several soil mechanics experiments. Piles of loose material churned up from the experiment are seen in front of and behind the Rover. The rock Pop-Tart is visible near the front right rover wheel. Yogi is at upper right. The image was taken by the Imager for Mars Pathfinder.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

Animal Detection in Natural Images: Effects of Color and Image Database

PubMed Central

Zhu, Weina; Drewes, Jan; Gegenfurtner, Karl R.

2013-01-01

The visual system has a remarkable ability to extract categorical information from complex natural scenes. In order to elucidate the role of low-level image features for the recognition of objects in natural scenes, we recorded saccadic eye movements and event-related potentials (ERPs) in two experiments, in which human subjects had to detect animals in previously unseen natural images. We used a new natural image database (ANID) that is free of some of the potential artifacts that have plagued the widely used COREL images. Color and grayscale images picked from the ANID and COREL databases were used. In all experiments, color images induced a greater N1 EEG component at earlier time points than grayscale images. We suggest that this influence of color in animal detection may be masked by later processes when measuring reation times. The ERP results of go/nogo and forced choice tasks were similar to those reported earlier. The non-animal stimuli induced bigger N1 than animal stimuli both in the COREL and ANID databases. This result indicates ultra-fast processing of animal images is possible irrespective of the particular database. With the ANID images, the difference between color and grayscale images is more pronounced than with the COREL images. The earlier use of the COREL images might have led to an underestimation of the contribution of color. Therefore, we conclude that the ANID image database is better suited for the investigation of the processing of natural scenes than other databases commonly used. PMID:24130744

Source misattributions and false recognition errors: examining the role of perceptual resemblance and imagery generation processes.

PubMed

Foley, Mary Ann; Bays, Rebecca Brooke; Foy, Jeffrey; Woodfield, Mila

2015-01-01

In three experiments, we examine the extent to which participants' memory errors are affected by the perceptual features of an encoding series and imagery generation processes. Perceptual features were examined by manipulating the features associated with individual items as well as the relationships among items. An encoding instruction manipulation was included to examine the effects of explicit requests to generate images. In all three experiments, participants falsely claimed to have seen pictures of items presented as words, committing picture misattribution errors. These misattribution errors were exaggerated when the perceptual resemblance between pictures and images was relatively high (Experiment 1) and when explicit requests to generate images were omitted from encoding instructions (Experiments 1 and 2). When perceptual cues made the thematic relationships among items salient, the level and pattern of misattribution errors were also affected (Experiments 2 and 3). Results address alternative views about the nature of internal representations resulting in misattribution errors and refute the idea that these errors reflect only participants' general impressions or beliefs about what was seen.

BlochSolver: A GPU-optimized fast 3D MRI simulator for experimentally compatible pulse sequences

NASA Astrophysics Data System (ADS)

Kose, Ryoichi; Kose, Katsumi

2017-08-01

A magnetic resonance imaging (MRI) simulator, which reproduces MRI experiments using computers, has been developed using two graphic-processor-unit (GPU) boards (GTX 1080). The MRI simulator was developed to run according to pulse sequences used in experiments. Experiments and simulations were performed to demonstrate the usefulness of the MRI simulator for three types of pulse sequences, namely, three-dimensional (3D) gradient-echo, 3D radio-frequency spoiled gradient-echo, and gradient-echo multislice with practical matrix sizes. The results demonstrated that the calculation speed using two GPU boards was typically about 7 TFLOPS and about 14 times faster than the calculation speed using CPUs (two 18-core Xeons). We also found that MR images acquired by experiment could be reproduced using an appropriate number of subvoxels, and that 3D isotropic and two-dimensional multislice imaging experiments for practical matrix sizes could be simulated using the MRI simulator. Therefore, we concluded that such powerful MRI simulators are expected to become an indispensable tool for MRI research and development.

Relative expertise affects N170 during selective attention to superimposed face-character images.

PubMed

Ip, Chengteng; Wang, Hailing; Fu, Shimin

2017-07-01

It remains unclear whether the N170 of ERPs reflects domain-specific or domain-general visual object processing. In this study, we used superimposed images of a face and a Chinese character such that participants' relative expertise for the two object types was either similar (Experiment 1 and 2) or different (Experiment 3). Experiment 1 showed that N170 amplitude was larger when participants attended to the character instead of the face of a face-character combination. This result was unchanged in Experiment 2, in which task difficulty was selectively increased for the face component of the combined stimuli. Experiment 3 showed that, although this N170 enhancement for attending to characters relative to faces persisted for false characters with recognizable parts, it disappeared for unrecognizable characters. Therefore, N170 amplitude was significantly greater for Chinese characters than for faces presented within a combined image, independent of the relative task difficulty. This result strongly calls N170 face selectivity into question, demonstrating that, contrary to the expectations established by a domain-specific account, N170 is modulated by expertise. © 2017 Society for Psychophysiological Research.

Reversible watermarking for authentication of DICOM images.

PubMed

Zain, J M; Baldwin, L P; Clarke, M

2004-01-01

We propose a watermarking scheme that can recover the original image from the watermarked one. The purpose is to verify the integrity and authenticity of DICOM images. We used 800x600x8 bits ultrasound (US) images in our experiment. SHA-256 of the whole image is embedded in the least significant bits of the RONI (Region of Non-Interest). If the image has not been altered, the watermark will be extracted and the original image will be recovered. SHA-256 of the recovered image will be compared with the extracted watermark for authentication.

Iterative image-domain ring artifact removal in cone-beam CT

NASA Astrophysics Data System (ADS)

Liang, Xiaokun; Zhang, Zhicheng; Niu, Tianye; Yu, Shaode; Wu, Shibin; Li, Zhicheng; Zhang, Huailing; Xie, Yaoqin

2017-07-01

Ring artifacts in cone beam computed tomography (CBCT) images are caused by pixel gain variations using flat-panel detectors, and may lead to structured non-uniformities and deterioration of image quality. The purpose of this study is to propose a method of general ring artifact removal in CBCT images. This method is based on the polar coordinate system, where the ring artifacts manifest as stripe artifacts. Using relative total variation, the CBCT images are first smoothed to generate template images with fewer image details and ring artifacts. By subtracting the template images from the CBCT images, residual images with image details and ring artifacts are generated. As the ring artifact manifests as a stripe artifact in a polar coordinate system, the artifact image can be extracted by mean value from the residual image; the image details are generated by subtracting the artifact image from the residual image. Finally, the image details are compensated to the template image to generate the corrected images. The proposed framework is iterated until the differences in the extracted ring artifacts are minimized. We use a 3D Shepp-Logan phantom, Catphan©504 phantom, uniform acrylic cylinder, and images from a head patient to evaluate the proposed method. In the experiments using simulated data, the spatial uniformity is increased by 1.68 times and the structural similarity index is increased from 87.12% to 95.50% using the proposed method. In the experiment using clinical data, our method shows high efficiency in ring artifact removal while preserving the image structure and detail. The iterative approach we propose for ring artifact removal in cone-beam CT is practical and attractive for CBCT guided radiation therapy.

Water surface capturing by image processing

USDA-ARS?s Scientific Manuscript database

An alternative means of measuring the water surface interface during laboratory experiments is processing a series of sequentially captured images. Image processing can provide a continuous, non-intrusive record of the water surface profile whose accuracy is not dependent on water depth. More trad...

High-Resolution Mars Camera Test Image of Moon Infrared

NASA Image and Video Library

2005-09-13

This crescent view of Earth Moon in infrared wavelengths comes from a camera test by NASA Mars Reconnaissance Orbiter spacecraft on its way to Mars. This image was taken by taken by the High Resolution Imaging Science Experiment camera Sept. 8, 2005.

Beauty in abstract paintings: perceptual contrast and statistical properties

PubMed Central

Mallon, Birgit; Redies, Christoph; Hayn-Leichsenring, Gregor U.

2014-01-01

In this study, we combined the behavioral and objective approach in the field of empirical aesthetics. First, we studied the perception of beauty by investigating shifts in evaluation on perceived beauty of abstract artworks (Experiment 1). Because the participants showed heterogeneous individual preferences for the paintings, we divided them into seven clusters for the test. The experiment revealed a clear pattern of perceptual contrast. The perceived beauty of abstract paintings increased after exposure to paintings that were rated as less beautiful, and it decreased after exposure to paintings that were rated as more beautiful. Next, we searched for correlations of beauty ratings and perceptual contrast with statistical properties of abstract artworks (Experiment 2). The participants showed significant preferences for particular image properties. These preferences differed between the clusters of participants. Strikingly, next to color measures like hue, saturation, value and lightness, the recently described Pyramid of Histograms of Orientation Gradients (PHOG) self-similarity value seems to be a predictor for aesthetic appreciation of abstract artworks. We speculate that the shift in evaluation in Experiment 1 was, at least in part, based on low-level adaptation to some of the statistical image properties analyzed in Experiment 2. In conclusion, our findings demonstrate that the perception of beauty in abstract artworks is altered after exposure to beautiful or non-beautiful images and correlates with particular image properties, especially color measures and self-similarity. PMID:24711791

Optics for Advanced Neutron Imaging and Scattering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moncton, David E.; Khaykovich, Boris

2016-03-30

During the report period, we continued the work as outlined in the original proposal. We have analyzed potential optical designs of Wolter mirrors for the neutron-imaging instrument VENUS, which is under construction at SNS. In parallel, we have conducted the initial polarized imaging experiment at Helmholtz Zentrum, Berlin, one of very few of currently available polarized-imaging facilities worldwide.

Rescripting Early Memories Linked to Negative Images in Social Phobia: A Pilot Study

ERIC Educational Resources Information Center

Wild, Jennifer; Hackmann, Ann; Clark, David M.

2008-01-01

Negative self-images are a maintaining factor in social phobia. A retrospective study (Hackmann, A., Clark, D.M., McManus, F. (2000). Recurrent images and early memories in social phobia. Behaviour Research and Therapy, 38, 601-610) suggested that the images may be linked to early memories of unpleasant social experiences. This preliminary study…

Polarimetric SAR calibration experiment using active radar calibrators

NASA Astrophysics Data System (ADS)

Freeman, Anthony; Shen, Yuhsyen; Werner, Charles L.

1990-03-01

Active radar calibrators are used to derive both the amplitude and phase characteristics of a multichannel polarimetric SAR from the complex image data. Results are presented from an experiment carried out using the NASA/JPL DC-8 aircraft SAR over a calibration site at Goldstone, California. As part of the experiment, polarimetric active radar calibrators (PARCs) with adjustable polarization signatures were deployed. Experimental results demonstrate that the PARCs can be used to calibrate polarimetric SAR images successfully. Restrictions on the application of the PARC calibration procedure are discussed.

Polarimetric SAR calibration experiment using active radar calibrators

NASA Technical Reports Server (NTRS)

Freeman, Anthony; Shen, Yuhsyen; Werner, Charles L.

1990-01-01

Active radar calibrators are used to derive both the amplitude and phase characteristics of a multichannel polarimetric SAR from the complex image data. Results are presented from an experiment carried out using the NASA/JPL DC-8 aircraft SAR over a calibration site at Goldstone, California. As part of the experiment, polarimetric active radar calibrators (PARCs) with adjustable polarization signatures were deployed. Experimental results demonstrate that the PARCs can be used to calibrate polarimetric SAR images successfully. Restrictions on the application of the PARC calibration procedure are discussed.

A Control System and Streaming DAQ Platform with Image-Based Trigger for X-ray Imaging

NASA Astrophysics Data System (ADS)

Stevanovic, Uros; Caselle, Michele; Cecilia, Angelica; Chilingaryan, Suren; Farago, Tomas; Gasilov, Sergey; Herth, Armin; Kopmann, Andreas; Vogelgesang, Matthias; Balzer, Matthias; Baumbach, Tilo; Weber, Marc

2015-06-01

High-speed X-ray imaging applications play a crucial role for non-destructive investigations of the dynamics in material science and biology. On-line data analysis is necessary for quality assurance and data-driven feedback, leading to a more efficient use of a beam time and increased data quality. In this article we present a smart camera platform with embedded Field Programmable Gate Array (FPGA) processing that is able to stream and process data continuously in real-time. The setup consists of a Complementary Metal-Oxide-Semiconductor (CMOS) sensor, an FPGA readout card, and a readout computer. It is seamlessly integrated in a new custom experiment control system called Concert that provides a more efficient way of operating a beamline by integrating device control, experiment process control, and data analysis. The potential of the embedded processing is demonstrated by implementing an image-based trigger. It records the temporal evolution of physical events with increased speed while maintaining the full field of view. The complete data acquisition system, with Concert and the smart camera platform was successfully integrated and used for fast X-ray imaging experiments at KIT's synchrotron radiation facility ANKA.

Roadway Marking Optics for Autonomous Vehicle Guidance and Other Machine Vision Applications

NASA Astrophysics Data System (ADS)

Konopka, Anthony T.

This work determines optimal planar geometric light source and optical imager configurations and electromagnetic wavelengths for maximizing the reflected signal intensity when using machine vision technology to image roadway markings with embedded spherical glass beads. It is found through a first set of experiments that roadway marking samples exhibiting little or no bead rolling effects are uniformly reflective with respect to the azimuthal angle of observation when measured for retroreflectivity within industry standard 30-meter geometry. A second set of experiments indicate that white roadway markings exhibit higher reflectivity throughout the visible spectrum than yellow roadway markings. A roadway marking optical model capable of being used to determine optimal geometric light source and optical imager configurations for maximizing the reflected signal intensities of roadway marking targets is constructed and simulated using optical engineering software. It is found through a third set of experiments that high signal intensities can be measured when the polar angles of the light source and optical imager along a plane normal to a roadway marking are equal, with the maximum signal intensity being measured when the polar angles of both the light source and optical imager are 90°.

Fabrication of Indocyanine Green and 2H, 3H-perfluoropentane loaded microbubbles for fluorescence and ultrasound imaging

NASA Astrophysics Data System (ADS)

He, Yutong; Wu, Qiang; Ma, Rong; Chang, Shufang; Shao, Pengfei; Xu, Ronald

2016-03-01

As a near-infrared (NIR) fluorescence dye, Indocyanine Green (ICG) has not gained broader clinical applications, owing to its multiple limitations such as concentration-dependent aggregation, low fluorescence quantum yield, poor physicochemical stability and rapid elimination from the body. In the meanwhile, 2H,3H-perfluoropentane (H-PFP) has been widely studied in ultrasound imaging as a vehicle for targeted delivery of contrast agents and drugs. We synthesized a novel dual-modal fluorescence and ultrasound contrast agent by encapsulating ICG and H-PFP in lipid microbubbles using a liquid-driven coaxial flow focusing (LDCFF) process. Uniform microbubbles with the sizes ranging from 1-10um and great ICG loading efficiency was achieved by this method. Our benchtop experiments showed that ICG/H-PFP microbubbles exhibited less aggregation, increased fluorescence intensity and more stable photostability compared to free ICG aqueous solution. Our phantom experiments demonstrated that ICG/H-PFP microbubbles enhanced the imaging contrasts in fluorescence imaging and ultrasonography. Our animal experiments indicated that ICG/H-PFP microbubbles extended the ICG life time and facilitated dual mode fluorescence and ultrasound imaging in vivo.

Forming impressions of facial attractiveness is mandatory.

PubMed

Ritchie, Kay L; Palermo, Romina; Rhodes, Gillian

2017-03-28

First impressions of social traits, such as attractiveness, from faces are often claimed to be made automatically, given their speed and reliability. However, speed of processing is only one aspect of automaticity. Here we address a further aspect, asking whether impression formation is mandatory. Mandatory formation requires that impressions are formed about social traits even when this is task-irrelevant, and that once formed, these impressions are difficult to inhibit. In two experiments, participants learned what new people looked like for the purpose of future identification, from sets of images high or low in attractiveness. They then rated middle-attractiveness images of each person, for attractiveness. Even though instructed to rate the specific images, not the people, their ratings were biased by the attractiveness of the learned images. A third control experiment, with participants rating names, demonstrated that participants in Experiments 1 and 2 were not simply rating the people, rather than the specific images as instructed. These results show that the formation of attractiveness impressions from faces is mandatory, thus broadening the evidence for automaticity of facial impressions. The mandatory formation of impressions is likely to have an important impact in real-world situations such as online dating sites.

Hard X-ray Imaging for Measuring Laser Absorption Spatial Profiles on the National Ignition Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dewald, E L; Jones, O S; Landen, O L

2006-04-25

Hard x-ray (''Thin wall'') imaging will be employed on the National Ignition Facility (NIF) to spatially locate laser beam energy deposition regions on the hohlraum walls in indirect drive Inertial Confinement Fusion (ICF) experiments, relevant for ICF symmetry tuning. Based on time resolved imaging of the hard x-ray emission of the laser spots, this method will be used to infer hohlraum wall motion due to x-ray and laser ablation and any beam refraction caused by plasma density gradients. In optimizing this measurement, issues that have to be addressed are hard x-ray visibility during the entire ignition laser pulse with intensitiesmore » ranging from 10{sup 13} to 10{sup 15} W/cm{sup 2}, as well as simultaneous visibility of the inner and the outer laser drive cones. In this work we will compare the hard x-ray emission calculated by LASNEX and analytical modeling with thin wall imaging data recorded previously on Omega and during the first hohlraum experiments on NIF. Based on these calculations and comparisons the thin wall imaging will be optimized for ICF/NIF experiments.« less

Photoelectrocyclization as an activation mechanism for organelle-specific live-cell imaging probes.

PubMed

Tran, Mai N; Chenoweth, David M

2015-05-26

Photoactivatable fluorophores are useful tools in live-cell imaging owing to their potential for precise spatial and temporal control. In this report, a new photoactivatable organelle-specific live-cell imaging probe based on a 6π electrocyclization/oxidation mechanism is described. It is shown that this new probe is water-soluble, non-cytotoxic, cell-permeable, and useful for mitochondrial imaging. The probe displays large Stokes shifts in both pre-activated and activated forms, allowing simultaneous use with common dyes and fluorescent proteins. Sequential single-cell activation experiments in dense cellular environments demonstrate high spatial precision and utility in single- or multi-cell labeling experiments. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Automated Quality Assessment of Colour Fundus Images for Diabetic Retinopathy Screening in Telemedicine.

PubMed

Saha, Sajib Kumar; Fernando, Basura; Cuadros, Jorge; Xiao, Di; Kanagasingam, Yogesan

2018-04-27

Fundus images obtained in a telemedicine program are acquired at different sites that are captured by people who have varying levels of experience. These result in a relatively high percentage of images which are later marked as unreadable by graders. Unreadable images require a recapture which is time and cost intensive. An automated method that determines the image quality during acquisition is an effective alternative. To determine the image quality during acquisition, we describe here an automated method for the assessment of image quality in the context of diabetic retinopathy. The method explicitly applies machine learning techniques to access the image and to determine 'accept' and 'reject' categories. 'Reject' category image requires a recapture. A deep convolution neural network is trained to grade the images automatically. A large representative set of 7000 colour fundus images was used for the experiment which was obtained from the EyePACS that were made available by the California Healthcare Foundation. Three retinal image analysis experts were employed to categorise these images into 'accept' and 'reject' classes based on the precise definition of image quality in the context of DR. The network was trained using 3428 images. The method shows an accuracy of 100% to successfully categorise 'accept' and 'reject' images, which is about 2% higher than the traditional machine learning method. On a clinical trial, the proposed method shows 97% agreement with human grader. The method can be easily incorporated with the fundus image capturing system in the acquisition centre and can guide the photographer whether a recapture is necessary or not.

When is an image a health claim? A false-recollection method to detect implicit inferences about products' health benefits.

PubMed

Klepacz, Naomi A; Nash, Robert A; Egan, M Bernadette; Hodgkins, Charo E; Raats, Monique M

2016-08-01

Images on food and dietary supplement packaging might lead people to infer (appropriately or inappropriately) certain health benefits of those products. Research on this issue largely involves direct questions, which could (a) elicit inferences that would not be made unprompted, and (b) fail to capture inferences made implicitly. Using a novel memory-based method, in the present research, we explored whether packaging imagery elicits health inferences without prompting, and the extent to which these inferences are made implicitly. In 3 experiments, participants saw fictional product packages accompanied by written claims. Some packages contained an image that implied a health-related function (e.g., a brain), and some contained no image. Participants studied these packages and claims, and subsequently their memory for seen and unseen claims were tested. When a health image was featured on a package, participants often subsequently recognized health claims that-despite being implied by the image-were not truly presented. In Experiment 2, these recognition errors persisted despite an explicit warning against treating the images as informative. In Experiment 3, these findings were replicated in a large consumer sample from 5 European countries, and with a cued-recall test. These findings confirm that images can act as health claims, by leading people to infer health benefits without prompting. These inferences appear often to be implicit, and could therefore be highly pervasive. The data underscore the importance of regulating imagery on product packaging; memory-based methods represent innovative ways to measure how leading (or misleading) specific images can be. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

ViCAR: An Adaptive and Landmark-Free Registration of Time Lapse Image Data from Microfluidics Experiments

PubMed Central

Hattab, Georges; Schlüter, Jan-Philip; Becker, Anke; Nattkemper, Tim W.

2017-01-01

In order to understand gene function in bacterial life cycles, time lapse bioimaging is applied in combination with different marker protocols in so called microfluidics chambers (i.e., a multi-well plate). In one experiment, a series of T images is recorded for one visual field, with a pixel resolution of 60 nm/px. Any (semi-)automatic analysis of the data is hampered by a strong image noise, low contrast and, last but not least, considerable irregular shifts during the acquisition. Image registration corrects such shifts enabling next steps of the analysis (e.g., feature extraction or tracking). Image alignment faces two obstacles in this microscopic context: (a) highly dynamic structural changes in the sample (i.e., colony growth) and (b) an individual data set-specific sample environment which makes the application of landmarks-based alignments almost impossible. We present a computational image registration solution, we refer to as ViCAR: (Vi)sual (C)ues based (A)daptive (R)egistration, for such microfluidics experiments, consisting of (1) the detection of particular polygons (outlined and segmented ones, referred to as visual cues), (2) the adaptive retrieval of three coordinates throughout different sets of frames, and finally (3) an image registration based on the relation of these points correcting both rotation and translation. We tested ViCAR with different data sets and have found that it provides an effective spatial alignment thereby paving the way to extract temporal features pertinent to each resulting bacterial colony. By using ViCAR, we achieved an image registration with 99.9% of image closeness, based on the average rmsd of 4.10−2 pixels, and superior results compared to a state of the art algorithm. PMID:28620411

Bone surface enhancement in ultrasound images using a new Doppler-based acquisition/processing method.

PubMed

Yang, Xu; Tang, Songyuan; Tasciotti, Ennio; Righetti, Raffaella

2018-01-17

Ultrasound (US) imaging has long been considered as a potential aid in orthopedic surgeries. US technologies are safe, portable and do not use radiations. This would make them a desirable tool for real-time assessment of fractures and to monitor fracture healing. However, image quality of US imaging methods in bone applications is limited by speckle, attenuation, shadow, multiple reflections and other imaging artifacts. While bone surfaces typically appear in US images as somewhat 'brighter' than soft tissue, they are often not easily distinguishable from the surrounding tissue. Therefore, US imaging methods aimed at segmenting bone surfaces need enhancement in image contrast prior to segmentation to improve the quality of the detected bone surface. In this paper, we present a novel acquisition/processing technique for bone surface enhancement in US images. Inspired by elastography and Doppler imaging methods, this technique takes advantage of the difference between the mechanical and acoustic properties of bones and those of soft tissues to make the bone surface more easily distinguishable in US images. The objective of this technique is to facilitate US-based bone segmentation methods and improve the accuracy of their outcomes. The newly proposed technique is tested both in in vitro and in vivo experiments. The results of these preliminary experiments suggest that the use of the proposed technique has the potential to significantly enhance the detectability of bone surfaces in noisy ultrasound images.

Bone surface enhancement in ultrasound images using a new Doppler-based acquisition/processing method

NASA Astrophysics Data System (ADS)

Yang, Xu; Tang, Songyuan; Tasciotti, Ennio; Righetti, Raffaella

2018-01-01

Ultrasound (US) imaging has long been considered as a potential aid in orthopedic surgeries. US technologies are safe, portable and do not use radiations. This would make them a desirable tool for real-time assessment of fractures and to monitor fracture healing. However, image quality of US imaging methods in bone applications is limited by speckle, attenuation, shadow, multiple reflections and other imaging artifacts. While bone surfaces typically appear in US images as somewhat ‘brighter’ than soft tissue, they are often not easily distinguishable from the surrounding tissue. Therefore, US imaging methods aimed at segmenting bone surfaces need enhancement in image contrast prior to segmentation to improve the quality of the detected bone surface. In this paper, we present a novel acquisition/processing technique for bone surface enhancement in US images. Inspired by elastography and Doppler imaging methods, this technique takes advantage of the difference between the mechanical and acoustic properties of bones and those of soft tissues to make the bone surface more easily distinguishable in US images. The objective of this technique is to facilitate US-based bone segmentation methods and improve the accuracy of their outcomes. The newly proposed technique is tested both in in vitro and in vivo experiments. The results of these preliminary experiments suggest that the use of the proposed technique has the potential to significantly enhance the detectability of bone surfaces in noisy ultrasound images.

Influence of study design on digital pathology image quality evaluation: the need to define a clinical task

PubMed Central

Platiša, Ljiljana; Brantegem, Leen Van; Kumcu, Asli; Ducatelle, Richard; Philips, Wilfried

2017-01-01

Abstract. Despite the current rapid advance in technologies for whole slide imaging, there is still no scientific consensus on the recommended methodology for image quality assessment of digital pathology slides. For medical images in general, it has been recommended to assess image quality in terms of doctors’ success rates in performing a specific clinical task while using the images (clinical image quality, cIQ). However, digital pathology is a new modality, and already identifying the appropriate task is difficult. In an alternative common approach, humans are asked to do a simpler task such as rating overall image quality (perceived image quality, pIQ), but that involves the risk of nonclinically relevant findings due to an unknown relationship between the pIQ and cIQ. In this study, we explored three different experimental protocols: (1) conducting a clinical task (detecting inclusion bodies), (2) rating image similarity and preference, and (3) rating the overall image quality. Additionally, within protocol 1, overall quality ratings were also collected (task-aware pIQ). The experiments were done by diagnostic veterinary pathologists in the context of evaluating the quality of hematoxylin and eosin-stained digital pathology slides of animal tissue samples under several common image alterations: additive noise, blurring, change in gamma, change in color saturation, and JPG compression. While the size of our experiments was small and prevents drawing strong conclusions, the results suggest the need to define a clinical task. Importantly, the pIQ data collected under protocols 2 and 3 did not always rank the image alterations the same as their cIQ from protocol 1, warning against using conventional pIQ to predict cIQ. At the same time, there was a correlation between the cIQ and task-aware pIQ ratings from protocol 1, suggesting that the clinical experiment context (set by specifying the clinical task) may affect human visual attention and bring focus to their criteria of image quality. Further research is needed to assess whether and for which purposes (e.g., preclinical testing) task-aware pIQ ratings could substitute cIQ for a given clinical task. PMID:28653011

Influence of study design on digital pathology image quality evaluation: the need to define a clinical task.

PubMed

Platiša, Ljiljana; Brantegem, Leen Van; Kumcu, Asli; Ducatelle, Richard; Philips, Wilfried

2017-04-01

Despite the current rapid advance in technologies for whole slide imaging, there is still no scientific consensus on the recommended methodology for image quality assessment of digital pathology slides. For medical images in general, it has been recommended to assess image quality in terms of doctors' success rates in performing a specific clinical task while using the images (clinical image quality, cIQ). However, digital pathology is a new modality, and already identifying the appropriate task is difficult. In an alternative common approach, humans are asked to do a simpler task such as rating overall image quality (perceived image quality, pIQ), but that involves the risk of nonclinically relevant findings due to an unknown relationship between the pIQ and cIQ. In this study, we explored three different experimental protocols: (1) conducting a clinical task (detecting inclusion bodies), (2) rating image similarity and preference, and (3) rating the overall image quality. Additionally, within protocol 1, overall quality ratings were also collected (task-aware pIQ). The experiments were done by diagnostic veterinary pathologists in the context of evaluating the quality of hematoxylin and eosin-stained digital pathology slides of animal tissue samples under several common image alterations: additive noise, blurring, change in gamma, change in color saturation, and JPG compression. While the size of our experiments was small and prevents drawing strong conclusions, the results suggest the need to define a clinical task. Importantly, the pIQ data collected under protocols 2 and 3 did not always rank the image alterations the same as their cIQ from protocol 1, warning against using conventional pIQ to predict cIQ. At the same time, there was a correlation between the cIQ and task-aware pIQ ratings from protocol 1, suggesting that the clinical experiment context (set by specifying the clinical task) may affect human visual attention and bring focus to their criteria of image quality. Further research is needed to assess whether and for which purposes (e.g., preclinical testing) task-aware pIQ ratings could substitute cIQ for a given clinical task.

Deep Learning Automates the Quantitative Analysis of Individual Cells in Live-Cell Imaging Experiments.

PubMed

Van Valen, David A; Kudo, Takamasa; Lane, Keara M; Macklin, Derek N; Quach, Nicolas T; DeFelice, Mialy M; Maayan, Inbal; Tanouchi, Yu; Ashley, Euan A; Covert, Markus W

2016-11-01

Live-cell imaging has opened an exciting window into the role cellular heterogeneity plays in dynamic, living systems. A major critical challenge for this class of experiments is the problem of image segmentation, or determining which parts of a microscope image correspond to which individual cells. Current approaches require many hours of manual curation and depend on approaches that are difficult to share between labs. They are also unable to robustly segment the cytoplasms of mammalian cells. Here, we show that deep convolutional neural networks, a supervised machine learning method, can solve this challenge for multiple cell types across the domains of life. We demonstrate that this approach can robustly segment fluorescent images of cell nuclei as well as phase images of the cytoplasms of individual bacterial and mammalian cells from phase contrast images without the need for a fluorescent cytoplasmic marker. These networks also enable the simultaneous segmentation and identification of different mammalian cell types grown in co-culture. A quantitative comparison with prior methods demonstrates that convolutional neural networks have improved accuracy and lead to a significant reduction in curation time. We relay our experience in designing and optimizing deep convolutional neural networks for this task and outline several design rules that we found led to robust performance. We conclude that deep convolutional neural networks are an accurate method that require less curation time, are generalizable to a multiplicity of cell types, from bacteria to mammalian cells, and expand live-cell imaging capabilities to include multi-cell type systems.

A magnetic resonance image-guided breast needle intervention robot system: overview and design considerations.

PubMed

Park, Samuel Byeongjun; Kim, Jung-Gun; Lim, Ki-Woong; Yoon, Chae-Hyun; Kim, Dong-Jun; Kang, Han-Sung; Jo, Yung-Ho

2017-08-01

We developed an image-guided intervention robot system that can be operated in a magnetic resonance (MR) imaging gantry. The system incorporates a bendable needle intervention robot for breast cancer patients that overcomes the space limitations of the MR gantry. Most breast coil designs for breast MR imaging have side openings to allow manual localization. However, for many intervention procedures, the patient must be removed from the gantry. A robotic manipulation system with integrated image guidance software was developed. Our robotic manipulator was designed to be slim, so as to fit between the patient's side and the MR gantry wall. Only non-magnetic materials were used, and an electromagnetic shield was employed for cables and circuits. The image guidance software was built using open source libraries. In situ feasibility tests were performed in a 3-T MR system. One target point in the breast phantom was chosen by the clinician for each experiment, and our robot moved the needle close to the target point. Without image-guided feedback control, the needle end could not hit the target point (distance = 5 mm) in the first experiment. Using our robotic system, the needle hits the target lesion of the breast phantom at a distance of 2.3 mm from the same target point using image-guided feedback. The second experiment was performed using other target points, and the distance between the final needle end point and the target point was 0.8 mm. We successfully developed an MR-guided needle intervention robot for breast cancer patients. Further research will allow the expansion of these interventions.

Deep Learning Automates the Quantitative Analysis of Individual Cells in Live-Cell Imaging Experiments

DOE PAGES

Van Valen, David A.; Kudo, Takamasa; Lane, Keara M.; ...

2016-11-04

Live-cell imaging has opened an exciting window into the role cellular heterogeneity plays in dynamic, living systems. A major critical challenge for this class of experiments is the problem of image segmentation, or determining which parts of a microscope image correspond to which individual cells. Current approaches require many hours of manual curation and depend on approaches that are difficult to share between labs. They are also unable to robustly segment the cytoplasms of mammalian cells. Here, we show that deep convolutional neural networks, a supervised machine learning method, can solve this challenge for multiple cell types across the domainsmore » of life. We demonstrate that this approach can robustly segment fluorescent images of cell nuclei as well as phase images of the cytoplasms of individual bacterial and mammalian cells from phase contrast images without the need for a fluorescent cytoplasmic marker. These networks also enable the simultaneous segmentation and identification of different mammalian cell types grown in co-culture. A quantitative comparison with prior methods demonstrates that convolutional neural networks have improved accuracy and lead to a significant reduction in curation time. We relay our experience in designing and optimizing deep convolutional neural networks for this task and outline several design rules that we found led to robust performance. We conclude that deep convolutional neural networks are an accurate method that require less curation time, are generalizable to a multiplicity of cell types, from bacteria to mammalian cells, and expand live-cell imaging capabilities to include multi-cell type systems.« less

Edge detection for optical synthetic aperture based on deep neural network

NASA Astrophysics Data System (ADS)

Tan, Wenjie; Hui, Mei; Liu, Ming; Kong, Lingqin; Dong, Liquan; Zhao, Yuejin

2017-09-01

Synthetic aperture optics systems can meet the demands of the next-generation space telescopes being lighter, larger and foldable. However, the boundaries of segmented aperture systems are much more complex than that of the whole aperture. More edge regions mean more imaging edge pixels, which are often mixed and discretized. In order to achieve high-resolution imaging, it is necessary to identify the gaps between the sub-apertures and the edges of the projected fringes. In this work, we introduced the algorithm of Deep Neural Network into the edge detection of optical synthetic aperture imaging. According to the detection needs, we constructed image sets by experiments and simulations. Based on MatConvNet, a toolbox of MATLAB, we ran the neural network, trained it on training image set and tested its performance on validation set. The training was stopped when the test error on validation set stopped declining. As an input image is given, each intra-neighbor area around the pixel is taken into the network, and scanned pixel by pixel with the trained multi-hidden layers. The network outputs make a judgment on whether the center of the input block is on edge of fringes. We experimented with various pre-processing and post-processing techniques to reveal their influence on edge detection performance. Compared with the traditional algorithms or their improvements, our method makes decision on a much larger intra-neighbor, and is more global and comprehensive. Experiments on more than 2,000 images are also given to prove that our method outperforms classical algorithms in optical images-based edge detection.

Deep Learning Automates the Quantitative Analysis of Individual Cells in Live-Cell Imaging Experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van Valen, David A.; Kudo, Takamasa; Lane, Keara M.

Live-cell imaging has opened an exciting window into the role cellular heterogeneity plays in dynamic, living systems. A major critical challenge for this class of experiments is the problem of image segmentation, or determining which parts of a microscope image correspond to which individual cells. Current approaches require many hours of manual curation and depend on approaches that are difficult to share between labs. They are also unable to robustly segment the cytoplasms of mammalian cells. Here, we show that deep convolutional neural networks, a supervised machine learning method, can solve this challenge for multiple cell types across the domainsmore » of life. We demonstrate that this approach can robustly segment fluorescent images of cell nuclei as well as phase images of the cytoplasms of individual bacterial and mammalian cells from phase contrast images without the need for a fluorescent cytoplasmic marker. These networks also enable the simultaneous segmentation and identification of different mammalian cell types grown in co-culture. A quantitative comparison with prior methods demonstrates that convolutional neural networks have improved accuracy and lead to a significant reduction in curation time. We relay our experience in designing and optimizing deep convolutional neural networks for this task and outline several design rules that we found led to robust performance. We conclude that deep convolutional neural networks are an accurate method that require less curation time, are generalizable to a multiplicity of cell types, from bacteria to mammalian cells, and expand live-cell imaging capabilities to include multi-cell type systems.« less