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Sample records for near-perfect retrieval efficiency

  1. Algorithms for efficient near-perfect phylogenetic tree reconstruction in theory and practice.

    PubMed

    Sridhar, Srinath; Dhamdhere, Kedar; Blelloch, Guy; Halperin, Eran; Ravi, R; Schwartz, Russell

    2007-01-01

    We consider the problem of reconstructing near-perfect phylogenetic trees using binary character states (referred to as BNPP). A perfect phylogeny assumes that every character mutates at most once in the evolutionary tree, yielding an algorithm for binary character states that is computationally efficient but not robust to imperfections in real data. A near-perfect phylogeny relaxes the perfect phylogeny assumption by allowing at most a constant number of additional mutations. We develop two algorithms for constructing optimal near-perfect phylogenies and provide empirical evidence of their performance. The first simple algorithm is fixed parameter tractable when the number of additional mutations and the number of characters that share four gametes with some other character are constants. The second, more involved algorithm for the problem is fixed parameter tractable when only the number of additional mutations is fixed. We have implemented both algorithms and shown them to be extremely efficient in practice on biologically significant data sets. This work proves the BNPP problem fixed parameter tractable and provides the first practical phylogenetic tree reconstruction algorithms that find guaranteed optimal solutions while being easily implemented and computationally feasible for data sets of biologically meaningful size and complexity.

  2. CRISPR/Cas9-Assisted Transformation-Efficient Reaction (CRATER) for Near-Perfect Selective Transformation

    NASA Technical Reports Server (NTRS)

    Rothschild, Lynn J.; Greenberg, Daniel T.; Takahashi, Jack R.; Thompson, Kirsten A.; Maheshwari, Akshay J.; Kent, Ryan E.; McCutcheon, Griffin; Shih, Joseph D.; Calvet, Charles; Devlin, Tyler D.; Ju, Tina; Kunin, Daniel; Lieberman, Erica; Nguyen, Thai; Tran, Forrest; Xiang, Daniel; Fujishima, Kosuke

    2015-01-01

    The CRISPR (Clustered, Regularly Interspaced, Short Palindromic Repeats)/Cas9 system has revolutionized genome editing by providing unprecedented DNA-targeting specificity. Here we demonstrate that this system can be also applied in vitro to fundamental cloning steps to facilitate efficient plasmid selection for transformation and selective gene insertion into plasmid vectors by cleaving unwanted plasmid byproducts with a single-guide RNA (sgRNA)-Cas9 nuclease complex. Using fluorescent and chromogenic proteins as reporters, we demonstrate that CRISPR/Cas9 cleavage excludes multiple plasmids as well as unwanted ligation byproducts resulting in an unprecedented increase in the transformation success rate from approximately 20% to nearly 100%. Thus, this CRISPR/Cas9-Assisted Transformation-Efficient Reaction (CRATER) protocol is a novel, inexpensive, and convenient application to conventional molecular cloning to achieve near-perfect selective transformation.

  3. Near perfect optics

    SciTech Connect

    Goeke, R.; Farnsworth, A.V.; Neumann, C.C.; Sweatt, W.C.; Warren, M.E.; Weed, J.W.

    1996-06-01

    This report discusses a novel fabrication process to produce nearly perfect optics. The process utilizes vacuum deposition techniques to optimally modify polished optical substrate surfaces. The surface figure, i.e. contour of a polished optical element, is improved by differentially filling in the low spots on the surface using flux from a physical vapor deposition source through an appropriate mask. The process is expected to enable the manufacture of diffraction-limited optical systems for the UV, extreme UV, and soft X-ray spectral regions, which would have great impact on photolithography and astronomy. This same technique may also reduce the fabrication cost of visible region optics with aspheric surfaces.

  4. Artificial perfect electric conductor-perfect magnetic conductor anisotropic metasurface for generating orbital angular momentum of microwave with nearly perfect conversion efficiency

    NASA Astrophysics Data System (ADS)

    Chen, Menglin L. N.; Jiang, Li Jun; Sha, Wei E. I.

    2016-02-01

    Orbital angular momentum (OAM) is a promising degree of freedom for fundamental studies in electromagnetics and quantum mechanics. The unlimited state space of OAM shows a great potential to enhance channel capacities of classical and quantum communications. By exploring the Pancharatnam-Berry phase concept and engineering anisotropic scatterers in a metasurface with spatially varying orientations, a plane wave with zero OAM can be converted to a vortex beam carrying nonzero OAM. In this paper, we proposed two types of novel perfect electric conductor-perfect magnetic conductor anisotropic metasurfaces. One is composed of azimuthally continuous loops and the other is constructed by azimuthally discontinuous dipole scatterers. Both types of metasurfaces are mounted on a mushroom-type high impedance surface. Compared to previous metasurface designs for generating OAM, the proposed ones achieve nearly perfect conversion efficiency. In view of the eliminated vertical component of electric field, the continuous metasurface shows very smooth phase pattern at the near-field region, which cannot be achieved by convectional metasurfaces composed of discrete scatterers. On the other hand, the metasurface with discrete dipole scatterers shows a great flexibility to generate OAM with arbitrary topological charges. Our work is fundamentally and practically important to high-performance OAM generation.

  5. Efficient Graffiti Image Retrieval

    SciTech Connect

    Yang, Chunlei; Wong, Pak C.; Ribarsky, William; Fan, Jianping

    2012-07-05

    Research of graffiti character recognition and retrieval, as a branch of traditional optical character recognition (OCR), has started to gain attention in recent years. We have investigated the special challenge of the graffiti image retrieval problem and propose a series of novel techniques to overcome the challenges. The proposed bounding box framework locates the character components in the graffiti images to construct meaningful character strings and conduct image-wise and semantic-wise retrieval on the strings rather than the entire image. Using real world data provided by the law enforcement community to the Pacific Northwest National Laboratory, we show that the proposed framework outperforms the traditional image retrieval framework with better retrieval results and improved computational efficiency.

  6. Near-perfect diffraction grating rhomb

    DOEpatents

    Wantuck, Paul J.

    1990-01-01

    A near-perfect grating rhomb enables an output beam to be diffracted to an angle offset from the input beam. The correcting grating is tipped relative to the dispersing grating to provide the offset angle. The correcting grating is further provided with a groove spacing which differs from the dispersing grating groove space by an amount effective to substantially remove angular dispersion in the output beam. A near-perfect grating rhomb has the capability for selective placement in a FEL to suppress sideband instabilities arising from the FEL.

  7. Nearly Perfect Fluidity in a High Temperature Superconductor

    DOE PAGESBeta

    Rameau, J. D.; Reber, T. J.; Yang, H. -B.; Akhanjee, S.; Gu, G. D.; Johnson, P. D.; Campbell, S.

    2014-10-13

    Perfect fluids are characterized as having the smallest ratio of shear viscosity to entropy density, η/s, consistent with quantum uncertainty and causality. So far, nearly perfect fluids have only been observed in the quark-gluon plasma and in unitary atomic Fermi gases, exotic systems that are amongst the hottest and coldest objects in the known universe, respectively. We use angle resolved photoemission spectroscopy to measure the temperature dependence of an electronic analog of η/s in an optimally doped cuprate high-temperature superconductor, finding it too is a nearly perfect fluid around, and above, its superconducting transition temperature Tc.

  8. Nearly Perfect Fluidity in a High Temperature Superconductor

    SciTech Connect

    Rameau, J. D.; Reber, T. J.; Yang, H. -B.; Akhanjee, S.; Gu, G. D.; Johnson, P. D.; Campbell, S.

    2014-10-13

    Perfect fluids are characterized as having the smallest ratio of shear viscosity to entropy density, η/s, consistent with quantum uncertainty and causality. So far, nearly perfect fluids have only been observed in the quark-gluon plasma and in unitary atomic Fermi gases, exotic systems that are amongst the hottest and coldest objects in the known universe, respectively. We use angle resolved photoemission spectroscopy to measure the temperature dependence of an electronic analog of η/s in an optimally doped cuprate high-temperature superconductor, finding it too is a nearly perfect fluid around, and above, its superconducting transition temperature Tc.

  9. Perfect and Near-Perfect Adaptation in Cell Signaling.

    PubMed

    Ferrell, James E

    2016-02-24

    Adaptation is an important basic feature of cellular regulation. Previous theoretical work has identified three types of circuits-negative feedback loops, incoherent feedforward systems, and state-dependent inactivation systems-that can achieve perfect or near-perfect adaptation. Recent work has added another strategy, termed antithetic integral feedback, to the list of motifs capable of robust perfect adaptation. Here, we discuss the properties, limitations, and biological relevance of each of these circuits. PMID:27135159

  10. Mirror-backed Dark Alumina: A Nearly Perfect Absorber for Thermoelectronics and Thermophotovotaics

    PubMed Central

    Farhat, Mohamed; Cheng, Tsung-Chieh; Le, Khai. Q.; Cheng, Mark Ming-Cheng; Bağcı, Hakan; Chen, Pai-Yen

    2016-01-01

    We present here a broadband, wide-angle, and polarization-independent nearly perfect absorber consisting of mirror-backed nanoporous alumina. By electrochemically anodizing the disordered multicomponent aluminum and properly tailoring the thickness and air-filling fraction of nanoporous alumina, according to the Maxwell-Garnet mixture theory, a large-area dark alumina can be made with excellent photothermal properties and absorption larger than 93% over a wide wavelength range spanning from near-infrared to ultraviolet light, i.e. 250 nm–2500 nm. The measured absorption is orders of magnitude greater than other reported anodized porous alumina, typically semi-transparent at similar wavelengths. This simple yet effective approach, however, does not require any lithography, nano-mixture deposition, pre- and post-treatment. Here, we also envisage and theoretically investigate the practical use of proposed absorbers and/or photothermal converters in integrated thermoelectronic and/or thermophotovoltaic energy conversion devices, which make efficient use of the entire spectrum of ambient visible to near-infrared radiation. PMID:26817710

  11. Simple mechanism whereby the F1-ATPase motor rotates with near-perfect chemomechanical energy conversion.

    PubMed

    Saita, Ei-ichiro; Suzuki, Toshiharu; Kinosita, Kazuhiko; Yoshida, Masasuke

    2015-08-01

    F1-ATPase is a motor enzyme in which a central shaft γ subunit rotates 120° per ATP in the cylinder made of α3β3 subunits. During rotation, the chemical energy of ATP hydrolysis (ΔGATP) is converted almost entirely into mechanical work by an elusive mechanism. We measured the force for rotation (torque) under various ΔGATP conditions as a function of rotation angles of the γ subunit with quasi-static, single-molecule manipulation and estimated mechanical work (torque × traveled angle) from the area of the function. The torque functions show three sawtooth-like repeats of a steep jump and linear descent in one catalytic turnover, indicating a simple physical model in which the motor is driven by three springs aligned along a 120° rotation angle. Although the second spring is unaffected by ΔGATP, activation of the first spring (timing of the torque jump) delays at low [ATP] (or high [ADP]) and activation of the third spring delays at high [Pi]. These shifts decrease the size and area of the sawtooth (magnitude of the work). Thus, F1-ATPase responds to the change of ΔGATP by shifting the torque jump timing and uses ΔGATP for the mechanical work with near-perfect efficiency.

  12. High-index dielectric meta-materials for near-perfect broadband reflectors

    NASA Astrophysics Data System (ADS)

    Liu, Zhengqi; Liu, Xiaoshan; Wang, Yan; Pan, Pingping

    2016-05-01

    All-dielectric meta-materials offer a potential alternative to plasmonic meta-materials at optical frequencies. Herein, we take advantage of loss-less as well as simple unit cell geometry to demonstrate near-perfect broadband reflectors made from all-dielectric materials. These near-perfect reflectors, consisting of high-index cross-shaped resonators (n  =  3.5, Si), operating in the telecommunications bands, exhibit novel optical properties including polarization-independent, wide-angle near-unity reflection. The average reflectance is exceeding 98% at the wavelength range from 1.261 μm to 1.533 μm. At 1.310 μm, the average reflectance (R) reaches 99.7%, surpassing the reflectance of metallic mirrors. A near-perfect super-broadband reflection spectrum with bandwidth of 0.330 μm (R  >  98%) is achieved for a system with a higher index dielectric resonator array (n  =  4.0, Ge). Moreover, the optical properties of the reflector provide high scalability across the wavelength range via tuning of dielectric resonators. The whole structure, with common triple-layer features, can be mass-produced using standard lithography methods and deposition techniques. These optical and structural features make the proposed near-perfect broadband reflectors feasible avenues for manipulating light in important applications in spectroscopy, photovoltaics and light emission.

  13. Why They Stayed: Near-Perfect Retention in an Online Certification Program in Library Media

    ERIC Educational Resources Information Center

    Meyer, Katrina A.; Bruwelheide, Janis; Poulin, Russell

    2009-01-01

    This paper focuses on an assessment of an online certification program in K-12 library media which has a near-perfect record of retaining students. Students and graduates of the program were asked to identify reasons for enrolling (and staying enrolled) in the program as well as functions that faculty performed well. These reasons were drawn upon…

  14. An Expressive and Efficient Language for XML Information Retrieval.

    ERIC Educational Resources Information Center

    Chinenyanga, Taurai Tapiwa; Kushmerick, Nicholas

    2002-01-01

    Discusses XML and information retrieval and describes a query language, ELIXIR (expressive and efficient language for XML information retrieval), with a textual similarity operator that can be used for similarity joins. Explains the algorithm for answering ELIXIR queries to generate intermediate relational data. (Author/LRW)

  15. General-Purpose Compression for Efficient Retrieval.

    ERIC Educational Resources Information Center

    Cannane, Adam; Williams, Hugh E.

    2001-01-01

    Discusses compression of databases that reduces space requirements and retrieval times; considers compression of documents in text databases based on semistatic modeling with words; and proposes a scheme for general purpose compression that can be applied to all types of data stored in large collections. (Author/LRW)

  16. Near-Perfect Adaptation in the E. coli Chemotaxis Signal Transduction Network

    NASA Astrophysics Data System (ADS)

    Yang, Yang; Setayeshgar, Sima

    2007-03-01

    Biochemical reaction networks constitute the computing language of the cell, from converting external stimuli into appropriate intracellular signals to regulating gene expression. Precise adaptation is an important property of many signaling networks, allowing compensation for continued stimulation without saturation. Furthermore, a common feature of intracellular reaction networks is the ability to operate in a noisy environment where concentrations of key components, such as signaling molecules and enzymes controlling reaction rates are typically small and therefore fluctuations in their numbers are significant. In the context of the well- characterized E. coli chemotaxis signal transduction network, we present a new computational scheme that explores surfaces in the space of total protein concentrations and reaction rates on which (near-)perfect adaptation holds. The resulting dependencies between parameters provide conditions for (near-)perfect adaptation as well as ranges of numerical values for parameters not reliably known from experiments. We generalize the applicability of this scheme to other signaling networks.

  17. HOTTER, SMALLER, DENSER, FASTER...AND NEARLY-PERFECT: WHAT IS THE MATTER AT RHIC?

    SciTech Connect

    STEINBERG,P.

    2006-07-03

    The experimental and theoretical status of the ''near perfect fluid'' at RHIC is discussed. While the hydrodynamic paradigm for understanding collisions at RHIC is well established, there remain many important open questions to address in order to understand its relevance and scope. It is also a crucial issue to understand how the early equilibration is achieved, requiring insight into the active degrees of freedom at early times.

  18. Strong coupling of plasmon and nanocavity modes for dual-band, near-perfect absorbers and ultrathin photovoltaics

    DOE PAGESBeta

    Hagglund, Carl; Zeltzer, Gabriel; Ruiz, Ricardo; Wangperawong, Artit; Roelofs, Katherine E.; Bent, Stacey F.

    2016-01-29

    In this study, when optical resonances interact strongly, hybridized modes are formed with mixed properties inherited from the basic modes. Strong coupling therefore tends to equalize properties such as damping and oscillator strength of the spectrally separate resonance modes. This effect is here shown to be very useful for the realization of near-perfect dual-band absorption with ultrathin (~10 nm) layers in a simple geometry. Absorber layers are constructed by atomic layer deposition of the heavy-damping semiconductor tin monosulfide (SnS) onto a two-dimensional gold nanodot array. In combination with a thin (55 nm) SiO2 spacer layer and a highly reflective Almore » film on the back, a semiopen nanocavity is formed. The SnS-coated array supports a localized surface plasmon resonance in the vicinity of the lowest order antisymmetric Fabry–Perot resonance of the nanocavity. Very strong coupling of the two resonances is evident through anticrossing behavior with a minimum peak splitting of 400 meV, amounting to 24% of the plasmon resonance energy. The mode equalization resulting from this strong interaction enables simultaneous optical impedance matching of the system at both resonances and thereby two near-perfect absorption peaks, which together cover a broad spectral range. When paired with the heavy damping from SnS band-to-band transitions, this further enables approximately 60% of normal incident solar photons with energies exceeding the band gap to be absorbed in the 10 nm SnS coating. Thereby, these results establish a distinct relevance of strong coupling phenomena to efficient, nanoscale photovoltaic absorbers and more generally for fulfilling a specific optical condition at multiple spectral positions.« less

  19. Evaluating cloud precipitation efficiency with satellite retrievals of water isotopologues

    NASA Astrophysics Data System (ADS)

    Bailey, A.; Noone, D. C.; Wood, R.

    2015-12-01

    The efficiency with which clouds precipitate is believed to influence climate by modifying cloud lifetime and, ultimately, cloud amount. Aerosols can influence this linkage by reducing the effective radii of cloud droplets and suppressing precipitation. This relationship, however, is not unidirectional. Cloud precipitation efficiency can also regulate particle concentrations, since precipitation effectively scavenges aerosols from the atmosphere. One challenge in studying how aerosols, clouds, and precipitation processes interrelate is that observational constraints are difficult to attain. This work evaluates the ability of isotope ratios in water vapor to quantify cloud precipitation efficiency across the tropical and subtropical oceans. Theory suggests isotope ratios will record the precipitation efficiency of a convective plume, since heavier isotopologues precipitate preferentially; and a recent analysis of in situ measurements from the Mauna Loa Observatory (MLO, Hawaii, USA) verifies this to be the case. The challenge now lies in understanding whether satellite retrievals of isotope ratios in water vapor are sensitive enough to track precipitation efficiency globally. To answer this question, vertical profiles of the D/H ratio derived from NASA's Tropospheric Emission Spectrometer (TES) are first compared with the MLO in situ measurements. A qualitative match indicates the satellite retrievals can distinguish high from low precipitation efficiency convection. To expand the analysis geographically, TES profiles between 40°S and 40°N are compared with estimates of precipitation efficiency derived from the Tropical Rainfall Measuring Mission (TRMM) and ECMWF's ERA-Interim. Retrievals are binned by lower-tropospheric humidity and by vertical velocity in order to minimize large-scale thermodynamical influences. Co-located cloud retrievals provide the context necessary to evaluate the utility of these new estimates in elucidating cloud feedbacks on climate.

  20. Efficient medical information retrieval in encrypted Electronic Health Records.

    PubMed

    Pruski, Cédric; Wisniewski, François

    2012-01-01

    The recent development of eHealth platforms across the world, whose main objective is to centralize patient's healthcare information to ensure the best continuity of care, requires the development of advanced tools and techniques for supporting health professionals in retrieving relevant information in this vast quantity of data. However, for preserving patient's privacy, some countries decided to de-identify and encrypt data contained in the shared Electronic Health Records, which reinforces the complexity of proposing efficient medical information retrieval approach. In this paper, we describe an original approach exploiting standards metadata as well as knowledge organizing systems to overcome the barriers of data encryption for improving the results of medical information retrieval in centralized and encrypted Electronic Health Records. This is done through the exploitation of semantic properties provided by knowledge organizing systems, which enable query expansion. Furthermore, we provide an overview of the approach together with illustrating examples and a discussion on the advantages and limitations of the provided framework.

  1. Near perfect mode overlap between independently seeded, gain-switched lasers

    NASA Astrophysics Data System (ADS)

    Comandar, L. C.; Lucamarini, M.; Fröhlich, B.; Dynes, J. F.; Yuan, Z. L.; Shields, A. J.

    2016-08-01

    We drastically improve the mode overlap between independently seeded, gain-switched laser diodes operating at gigahertz repetition rates by implementing a pulsed light seeding technique. Injecting pulsed light reduces the emission time jitter and enables frequency chirp synchronization while maintaining random optical phases of the emitted laser pulses. We measure interference of these pulsed sources both in the macroscopic regime, where we demonstrate near perfect mode overlap, and in the single photon regime, where we achieve a Hong-Ou-Mandel dip visibility of 0.499+/-0.004, thus saturating the theoretical limit of 0.5. The measurement results are reproduced by Monte-Carlo simulations with no free parameters. Our light source is an ideal solution for generation of high rate, indistinguishable coherent pulses for quantum information applications.

  2. Self-assembly and near perfect macroscopic alignment of fluorescent triangulenium salt in spin-cast thin films on PTFE.

    PubMed

    Westerlund, Fredrik; Lemke, Henrik T; Hassenkam, Tue; Simonsen, Jens B; Laursen, Bo W

    2013-06-01

    Highly fluorescent, discotic trioxatriangulenium dyes were aligned by simple spin-casting on substrates with friction transferred PTFE layers. The fluorescent crystalline thin films show near perfect macroscopic alignment on centimeter large areas directly from spin-casting. Gracing Incidence X-ray Diffraction (GIXD) unambiguously allowed the determination of a long-range order unit cell as well as its orientation with respect to the PTFE fibers. Further analysis of the X-ray data, in conjunction with polarized absorption spectroscopy, suggest a lamellar packing model with alternating layers of alkyl chains and ionic dyes oriented parallel to the substrate. This structure results in a highly anisotropic electrostatic potential around the cationic chromophore, causing significant shifts in energy and orientation of the optical transitions. Thus, the optical properties of the material are, to a large extent, controlled by the position of the otherwise inert PF6(-) counterions. The bright fluorescence from the films is also polarized parallel to the PTFE alignment layer. Doping of the thin films with fluorescent energy acceptor traps shows that efficient exciton migration takes place in the thin films. The excellent exciton transfer capabilities, in conjunction with the perfect alignment, might be of interest in future applications in solar energy harvesting or as thin film sensors. PMID:23627252

  3. Nearly Perfect Spin Filter, Spin Valve and Negative Differential Resistance Effects in a Fe4-based Single-molecule Junction

    PubMed Central

    Zu, Fengxia; Liu, Zuli; Yao, Kailun; Gao, Guoying; Fu, Huahua; Zhu, Sicong; Ni, Yun; Peng, Li

    2014-01-01

    The spin-polarized transport in a single-molecule magnet Fe4 sandwiched between two gold electrodes is studied, using nonequilibrium Green's functions in combination with the density-functional theory. We predict that the device possesses spin filter effect (SFE), spin valve effect (SVE), and negative differential resistance (NDR) behavior. Moreover, we also find that the appropriate chemical ligand, coupling the single molecule to leads, is a key factor for manipulating spin-dependent transport. The device containing the methyl ligand behaves as a nearly perfect spin filter with efficiency approaching 100%, and the transport is dominated by transmission through the Fe4 metal center. However, in the case of phenyl ligand, the spin filter effect seems to be reduced, but the spin valve effect is significantly enhanced with a large magnetoresistance ratio, reaching 1800%. This may be attributed to the blocking effect of the phenyl ligands in mediating transport. Our findings suggest that such a multifunctional molecular device, possessing SVE, NDR and high SFE simultaneously, would be an excellent candidate for spintronics of molecular devices. PMID:24787446

  4. Nearly perfect spin filter, spin valve and negative differential resistance effects in a Fe4-based single-molecule junction.

    PubMed

    Zu, Fengxia; Liu, Zuli; Yao, Kailun; Gao, Guoying; Fu, Huahua; Zhu, Sicong; Ni, Yun; Peng, Li

    2014-01-01

    The spin-polarized transport in a single-molecule magnet Fe4 sandwiched between two gold electrodes is studied, using nonequilibrium Green's functions in combination with the density-functional theory. We predict that the device possesses spin filter effect (SFE), spin valve effect (SVE), and negative differential resistance (NDR) behavior. Moreover, we also find that the appropriate chemical ligand, coupling the single molecule to leads, is a key factor for manipulating spin-dependent transport. The device containing the methyl ligand behaves as a nearly perfect spin filter with efficiency approaching 100%, and the transport is dominated by transmission through the Fe4 metal center. However, in the case of phenyl ligand, the spin filter effect seems to be reduced, but the spin valve effect is significantly enhanced with a large magnetoresistance ratio, reaching 1800%. This may be attributed to the blocking effect of the phenyl ligands in mediating transport. Our findings suggest that such a multifunctional molecular device, possessing SVE, NDR and high SFE simultaneously, would be an excellent candidate for spintronics of molecular devices. PMID:24787446

  5. A Silicon-Based, Sequential Coat-and-Etch Process to Fabricate Nearly Perfect Substrate Surfaces

    SciTech Connect

    Mirkarimi, P B; Spiller, E; Baker, S L; Stearns, D G; Robinson, J C; Olynick, D L; Salmassi, F; Liddle, J A; Liang, T; Stivers, A R

    2005-07-05

    For many thin-film applications substrate imperfections such as particles, pits, scratches, and general roughness, can nucleate film defects which can severely detract from the coating's performance. Previously we developed a coat-and-etch process, termed the ion beam thin film planarization process, to planarize substrate particles up to {approx} 70 nm in diameter. The process relied on normal incidence etching; however, such a process induces defects nucleated by substrate pits to grow much larger. We have since developed a coat-and-etch process to planarize {approx}70 nm deep by 70 nm wide substrate pits; it relies on etching at an off-normal incidence angle, i.e., an angle of {approx} 70{sup o} from the substrate normal. However, a disadvantage of this pit smoothing process is that it induces defects nucleated by substrate particles to grow larger. Combining elements from both processes we have been able to develop a silicon-based, coat-and-etch process to successfully planarize {approx}70 nm substrate particles and pits simultaneously to at or below 1 nm in height; this value is important for applications such as extreme ultraviolet lithography (EUVL) masks. The coat-and-etch process has an added ability to significantly reduce high-spatial frequency roughness, rendering a nearly perfect substrate surface.

  6. Adsorption of Te on Ge(001): Nearly Perfect Dereconstruction and Structural Phase Transition

    NASA Astrophysics Data System (ADS)

    Lyman, P. F.; Marasco, D. L.; Bedzyk, M. J.

    1998-03-01

    The (001) face of a diamond-structure semiconductor has two dangling bonds per surface atom. Therefore, the adsorption of 1 ML of a hexavalent group VI element could saturate all available surface bonds, resulting in a perfect (1×1) termination. This adsorbate-induced dereconstruction has previously been demonstrated for S/Ge(001) and, somewhat imperfectly, for Te/Si(001). Here we describe a study of the local structure and long-range order of Te/Ge(001) using x-ray standing waves (XSW) and LEED for annealing temperatures of 540 K and 670 K. At 540 K, Te exclusively occupied the expected bridge sites, forming a (1×1) local structure. Thus, the Te atoms caused a nearly perfect dereconstruction of the Ge(001) dimerized clean surface. The streaky (2×1) LEED pattern betrayed a small remaining pairing tendency. Upon annealing to 670 K, the Te exhibited a new and surprising behavior. A clear phase transition occurred, indicated both by a dramatic change in the LEED pattern to a streaky c(2×2), and decrease of the Te adsorption height by 0.07 ÅWe hypothesize that approximately half of the Te desorbed, and some of the Ge surface atoms redimerized; the remaining Te atoms occupy "cave" (or long bridge) sites, between two Ge dimers.

  7. Efficient Lookup Table Retrievals of Gas Abundance from CRISM Spectra

    NASA Astrophysics Data System (ADS)

    Toigo, A. D.; Smith, M. D.; Seelos, F. P.; CRISM Science; Operations Teams

    2011-12-01

    The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument on the Mars Reconnaissance Orbiter (MRO) spacecraft has been collecting spectra in the visible to near-infrared on Mars for over 5 years (almost 3 Martian years). Observations consist of image cubes, with two main spectral samplings (approximately 70 and 550 spectral channels) and two main imaging resolutions (approximately 20 and 200 m/pixel). We present retrievals of gas abundances, specifically CO2, H2O, and CO, from spectra collected in all observation modes. The retrievals are efficiently performed using a lookup table, where the strength of gas absorption features are pre-calculated for an N-dimensional discrete grid of known input parameters (season, location, environment, viewing geometry, etc.) and the one unknown parameter to be retrieved (gas abundance). A reverse interpolation in the lookup table is used to match the observed strength of the gas absorption to the gas abundance. This algorithm is extremely fast compared to traditional radiative transfer computations that seek to recursively fit calculated results to an observed spectral feature, and can therefore be applied on a pixel-by-pixel basis to the tens of thousands of CRISM images, to examine cross-scene structure as well as to produce climatological averages.

  8. Despite slow catalysis and confused substrate specificity, all ribulose bisphosphate carboxylases may be nearly perfectly optimized

    PubMed Central

    Tcherkez, Guillaume G. B.; Farquhar, Graham D.; Andrews, T. John

    2006-01-01

    The cornerstone of autotrophy, the CO2-fixing enzyme, d-ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), is hamstrung by slow catalysis and confusion between CO2 and O2 as substrates, an “abominably perplexing” puzzle, in Darwin's parlance. Here we argue that these characteristics stem from difficulty in binding the featureless CO2 molecule, which forces specificity for the gaseous substrate to be determined largely or completely in the transition state. We hypothesize that natural selection for greater CO2/O2 specificity, in response to reducing atmospheric CO2:O2 ratios, has resulted in a transition state for CO2 addition in which the CO2 moiety closely resembles a carboxylate group. This maximizes the structural difference between the transition states for carboxylation and the competing oxygenation, allowing better differentiation between them. However, increasing structural similarity between the carboxylation transition state and its carboxyketone product exposes the carboxyketone to the strong binding required to stabilize the transition state and causes the carboxyketone intermediate to bind so tightly that its cleavage to products is slowed. We assert that all Rubiscos may be nearly perfectly adapted to the differing CO2, O2, and thermal conditions in their subcellular environments, optimizing this compromise between CO2/O2 specificity and the maximum rate of catalytic turnover. Our hypothesis explains the feeble rate enhancement displayed by Rubisco in processing the exogenously supplied carboxyketone intermediate, compared with its nonenzymatic hydrolysis, and the positive correlation between CO2/O2 specificity and 12C/13C fractionation. It further predicts that, because a more product-like transition state is more ordered (decreased entropy), the effectiveness of this strategy will deteriorate with increasing temperature. PMID:16641091

  9. An efficient and effective region-based image retrieval framework.

    PubMed

    Jing, Feng; Li, Mingjing; Zhang, Hong-Jiang; Zhang, Bo

    2004-05-01

    An image retrieval framework that integrates efficient region-based representation in terms of storage and complexity and effective on-line learning capability is proposed. The framework consists of methods for region-based image representation and comparison, indexing using modified inverted files, relevance feedback, and learning region weighting. By exploiting a vector quantization method, both compact and sparse (vector) region-based image representations are achieved. Using the compact representation, an indexing scheme similar to the inverted file technology and an image similarity measure based on Earth Mover's Distance are presented. Moreover, the vector representation facilitates a weighted query point movement algorithm and the compact representation enables a classification-based algorithm for relevance feedback. Based on users' feedback information, a region weighting strategy is also introduced to optimally weight the regions and enable the system to self-improve. Experimental results on a database of 10,000 general-purposed images demonstrate the efficiency and effectiveness of the proposed framework.

  10. Efficient Query-by-Content Audio Retrieval by Locality Sensitive Hashing and Partial Sequence Comparison

    NASA Astrophysics Data System (ADS)

    Yu, Yi; Joe, Kazuki; Downie, J. Stephen

    This paper investigates suitable indexing techniques to enable efficient content-based audio retrieval in large acoustic databases. To make an index-based retrieval mechanism applicable to audio content, we investigate the design of Locality Sensitive Hashing (LSH) and the partial sequence comparison. We propose a fast and efficient audio retrieval framework of query-by-content and develop an audio retrieval system. Based on this framework, four different audio retrieval schemes, LSH-Dynamic Programming (DP), LSH-Sparse DP (SDP), Exact Euclidian LSH (E2LSH)-DP, E2LSH-SDP, are introduced and evaluated in order to better understand the performance of audio retrieval algorithms. The experimental results indicate that compared with the traditional DP and the other three compititive schemes, E2LSH-SDP exhibits the best tradeoff in terms of the response time, retrieval accuracy and computation cost.

  11. Efficient Methods to Assimilate Satellite Retrievals Based on Information Content. Part 2; Suboptimal Retrieval Assimilation

    NASA Technical Reports Server (NTRS)

    Joiner, J.; Dee, D. P.

    1998-01-01

    One of the outstanding problems in data assimilation has been and continues to be how best to utilize satellite data while balancing the tradeoff between accuracy and computational cost. A number of weather prediction centers have recently achieved remarkable success in improving their forecast skill by changing the method by which satellite data are assimilated into the forecast model from the traditional approach of assimilating retrievals to the direct assimilation of radiances in a variational framework. The operational implementation of such a substantial change in methodology involves a great number of technical details, e.g., pertaining to quality control procedures, systematic error correction techniques, and tuning of the statistical parameters in the analysis algorithm. Although there are clear theoretical advantages to the direct radiance assimilation approach, it is not obvious at all to what extent the improvements that have been obtained so far can be attributed to the change in methodology, or to various technical aspects of the implementation. The issue is of interest because retrieval assimilation retains many practical and logistical advantages which may become even more significant in the near future when increasingly high-volume data sources become available. The central question we address here is: how much improvement can we expect from assimilating radiances rather than retrievals, all other things being equal? We compare the two approaches in a simplified one-dimensional theoretical framework, in which problems related to quality control and systematic error correction are conveniently absent. By assuming a perfect radiative transfer model and perfect knowledge of radiance and background error covariances, we are able to formulate a nonlinear local error analysis for each assimilation method. Direct radiance assimilation is optimal in this idealized context, while the traditional method of assimilating retrievals is suboptimal because it

  12. 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…

  13. Conformal dual-band near-perfectly absorbing mid-infrared metamaterial coating.

    PubMed

    Jiang, Zhi Hao; Yun, Seokho; Toor, Fatima; Werner, Douglas H; Mayer, Theresa S

    2011-06-28

    Metamaterials offer a new approach to create surface coatings with highly customizable electromagnetic absorption from the microwave to the optical regimes. Thus far, efficient metamaterial absorbers have been demonstrated at microwave frequencies, with recent efforts aimed at much shorter terahertz and infrared wavelengths. The present infrared absorbers have been constructed from arrays of nanoscale metal resonators with simple circular or cross-shaped geometries, which provide a single band response. In this paper, we demonstrate a conformal metamaterial absorber with a narrow band, polarization-independent absorptivity of >90% over a wide ±50° angular range centered at mid-infrared wavelengths of 3.3 and 3.9 μm. The highly efficient dual-band metamaterial was realized by using a genetic algorithm to identify an array of H-shaped nanoresonators with an effective electric and magnetic response that maximizes absorption in each wavelength band when patterned on a flexible Kapton and Au thin film substrate stack. This conformal metamaterial absorber maintains its absorption properties when integrated onto curved surfaces of arbitrary materials, making it attractive for advanced coatings that suppress the infrared reflection from the protected surface. PMID:21456579

  14. Conformal dual-band near-perfectly absorbing mid-infrared metamaterial coating.

    PubMed

    Jiang, Zhi Hao; Yun, Seokho; Toor, Fatima; Werner, Douglas H; Mayer, Theresa S

    2011-06-28

    Metamaterials offer a new approach to create surface coatings with highly customizable electromagnetic absorption from the microwave to the optical regimes. Thus far, efficient metamaterial absorbers have been demonstrated at microwave frequencies, with recent efforts aimed at much shorter terahertz and infrared wavelengths. The present infrared absorbers have been constructed from arrays of nanoscale metal resonators with simple circular or cross-shaped geometries, which provide a single band response. In this paper, we demonstrate a conformal metamaterial absorber with a narrow band, polarization-independent absorptivity of >90% over a wide ±50° angular range centered at mid-infrared wavelengths of 3.3 and 3.9 μm. The highly efficient dual-band metamaterial was realized by using a genetic algorithm to identify an array of H-shaped nanoresonators with an effective electric and magnetic response that maximizes absorption in each wavelength band when patterned on a flexible Kapton and Au thin film substrate stack. This conformal metamaterial absorber maintains its absorption properties when integrated onto curved surfaces of arbitrary materials, making it attractive for advanced coatings that suppress the infrared reflection from the protected surface.

  15. Electric- and exchange-field controlled transport through silicene barriers: Conductance gap and near-perfect spin polarization

    SciTech Connect

    Vargiamidis, V.; Vasilopoulos, P.

    2014-12-01

    We study ballistic electron transport through silicene barriers, of width d and height U, in the presence of an exchange field M and a normal electric field E{sub z}. Away from the Dirac point (DP), the spin- and valley-resolved conductances, as functions of U, exhibit resonances while close to it there is a pronounced dip that can be transformed into a transport gap by varying E{sub z}. The charge conductance g{sub c} changes from oscillatory to a monotonically decreasing function of d beyond a critical E{sub z} and this can be used to realize electric-field-controlled switching. Further, the field M splits each resonance of g{sub c} into two spin-resolved peaks. The spin polarization near the DP increases with E{sub z} or M and becomes nearly perfect above certain of their values. Similar results hold for double barriers.

  16. A Continuing Search for a Near-Perfect Numerical Flux Scheme. Part 1; [AUSM+

    NASA Technical Reports Server (NTRS)

    Liou, Meng-Sing

    1994-01-01

    While enjoying demonstrated improvement in accuracy, efficiency, and robustness over existing schemes, the Advection Upstream Splitting Scheme (AUSM) was found to have some deficiencies in extreme cases. This recent progress towards improving the AUSM while retaining its advantageous features is described. The new scheme, termed AUSM+, features: unification of velocity and Mach number splitting; exact capture of a single stationary shock; and improvement in accuracy. A general construction of the AUSM+ scheme is layed out and then focus is on the analysis of the a scheme and its mathematical properties, heretofore unreported. Monotonicity and positivity are proved, and a CFL-like condition is given for first and second order schemes and for generalized curvilinear co-ordinates. Finally, results of numerical tests on many problems are given to confirm the capability and improvements on a variety of problems including those failed by prominent schemes.

  17. Retrieval practice is an efficient method of enhancing the retention of anatomy and physiology information.

    PubMed

    Dobson, John L

    2013-06-01

    Although a great deal of empirical evidence has indicated that retrieval practice is an effective means of promoting learning and memory, very few studies have investigated the strategy in the context of an actual class. The primary purpose of this study was to determine if a series of very brief retrieval quizzes could significantly improve the retention of previously tested information throughout an anatomy and physiology course. A second purpose was to determine if there were any significant differences between expanding and uniform patterns of retrieval that followed a standardized initial retrieval delay. Anatomy and physiology students were assigned to either a control group or groups that were repeatedly prompted to retrieve a subset of previously tested course information via a series of quizzes that were administered on either an expanding or a uniform schedule. Each retrieval group completed a total of 10 retrieval quizzes, and the series of quizzes required (only) a total of 2 h to complete. Final retention of the exam subset material was assessed during the last week of the semester. There were no significant differences between the expanding and uniform retrieval groups, but both retained an average of 41% more of the subset material than did the control group (ANOVA, F = 129.8, P = 0.00, ηp(2) = 0.36). In conclusion, retrieval practice is a highly efficient and effective strategy for enhancing the retention of anatomy and physiology material.

  18. Efficient multifeature index structures for music data retrieval

    NASA Astrophysics Data System (ADS)

    Lee, Wegin; Chen, Arbee L. P.

    1999-12-01

    In this paper, we propose four index structures for music data retrieval. Based on suffix trees, we develop two index structures called combined suffix tree and independent suffix trees. These methods still show shortcomings for some search functions. Hence we develop another index, called Twin Suffix Trees, to overcome these problems. However, the Twin Suffix Trees lack of scalability when the amount of music data becomes large. Therefore we propose the fourth index, called Grid-Twin Suffix Trees, to provide scalability and flexibility for a large amount of music data. For each index, we can use different search functions, like exact search and approximate search, on different music features, like melody, rhythm or both. We compare the performance of the different search functions applied on each index structure by a series of experiments.

  19. Vapor-deposited amorphous metamaterials as visible near-perfect absorbers with random non-prefabricated metal nanoparticles

    PubMed Central

    Zhang, Yun; Wei, Tiaoxing; Dong, Wenjing; Zhang, Kenan; Sun, Yan; Chen, Xin; Dai, Ning

    2014-01-01

    Spatial order or periodicity is usually required and constructed with tens of nanometers in the feature size, which makes it difficult to process the near-perfect metamaterial absorbers (PMAs) working in the visible range in large-area and mass-production scale. Although many established technologies and theoretical modeling methods used for order-based metamaterials, aperiodic or disordered structures have been gradually recognized to achieve similar functionalities for which the ordered structures are overwhelmingly used. Here, we demonstrated the vapor-deposited ‘amorphous’ metamaterials as controlled-reflectance surfaces and tunable PMAs without the use of the lithographically ordered arrays, the prefabricated colloidal metal nanoparticles (MNPs) or the multilayer of nanoparticles. The flexible construction, the control of the monolayer of MNPs and the atomic-layer-deposited (ALD) dielectric spacer layer provide more insight for understanding the controlled-reflectance surfaces. Such processes have a few key advantages of CMOS-compatible simple processing, low cost and large-area plating, allowing the PMAs to be flexibly constructed in mass-production scale. PMID:24810434

  20. On the retrieval efficiency of light storage in an EIT medium

    NASA Astrophysics Data System (ADS)

    Chough, Young-Tak

    2016-08-01

    We investigate the retrieval efficiency of light slowed and/or stored in a medium with electromagnetically-induced transparency (an EIT medium) by numerical simulations based on first principles. Starting from the master equation formulation, we derive the full dynamics of the system and then show how the approximations are applied to reduce the number of dynamical equations. While operating the system as an optical "retarder," a "reflector," and a "beam-splitter," we find that the total retrieval efficiency in the case of the "beam-splitter" operation is lower than that in either of the other two operations. Nevertheless, we find that (1) when an appropriate value of detuning is applied between the two counter-propagating " read"-fields, the retrieval efficiency in the latter case can be significantly improved, (2) storing the signal in the form of the atomic spin wave is more advantageous than storing it in the form of a stationary light pulse (SLP), and (3) the retrieval efficiency can be augmented by increasing the strengths of the " read"-fields.

  1. Intelligence as the efficiency of cue-driven retrieval from secondary memory.

    PubMed

    Liesefeld, Heinrich René; Hoffmann, Eugenia; Wentura, Dirk

    2016-01-01

    Complex-span (working-memory-capacity) tasks are among the most successful predictors of intelligence. One important contributor to this relationship is the ability to efficiently employ cues for the retrieval from secondary memory. Presumably, intelligent individuals can considerably restrict their memory search sets by using such cues and can thereby improve recall performance. We here test this assumption by experimentally manipulating the validity of retrieval cues. When memoranda are drawn from the same semantic category on two successive trials of a verbal complex-span task, the category is a very strong retrieval cue on its first occurrence (strong-cue trial) but loses some of its validity on its second occurrence (weak-cue trial). If intelligent individuals make better use of semantic categories as retrieval cues, their recall accuracy suffers more from this loss of cue validity. Accordingly, our results show that less variance in intelligence is explained by recall accuracy on weak-cue compared with strong-cue trials.

  2. High efficient methods of content-based 3D model retrieval

    NASA Astrophysics Data System (ADS)

    Wu, Yuanhao; Tian, Ling; Li, Chenggang

    2013-03-01

    Content-based 3D model retrieval is of great help to facilitate the reuse of existing designs and to inspire designers during conceptual design. However, there is still a gap to apply it in industry due to the low time efficiency. This paper presents two new methods with high efficiency to build a Content-based 3D model retrieval system. First, an improvement is made on the "Shape Distribution (D2)" algorithm, and a new algorithm named "Quick D2" is proposed. Four sample 3D mechanical models are used in an experiment to compare the time cost of the two algorithms. The result indicates that the time cost of Quick D2 is much lower than that of D2, while the descriptors extracted by the two algorithms are almost the same. Second, an expandable 3D model repository index method with high performance, namely, RBK index, is presented. On the basis of RBK index, the search space is pruned effectively during the search process, leading to a speed up of the whole system. The factors that influence the values of the key parameters of RBK index are discussed and an experimental method to find the optimal values of the key parameters is given. Finally, "3D Searcher", a content-based 3D model retrieval system is developed. By using the methods proposed, the time cost for the system to respond one query online is reduced by 75% on average. The system has been implemented in a manufacturing enterprise, and practical query examples during a case of the automobile rear axle design are also shown. The research method presented shows a new research perspective and can effectively improve the content-based 3D model retrieval efficiency.

  3. Carbon nanotube-based tandem absorber with tunable spectral selectivity: transition from near-perfect blackbody absorber to solar selective absorber.

    PubMed

    Selvakumar, N; Krupanidhi, S B; Barshilia, Harish C

    2014-04-23

    CVD grown CNT thin film with a thickness greater than 10 μm behaves like a near-perfect blackbody absorber (i.e., α/ε = 0.99/0.99). Whereas, for a thickness ≤ 0.4 µm, the CNT based tandem absorber acts as a spectrally selective coating (i.e., α/ε = 0.95/0.20). These selective coatings exhibit thermal stability up to 650 °C in vacuum, which can be used for solar thermal power generation. PMID:24474148

  4. Knowledge-Based Query Construction Using the CDSS Knowledge Base for Efficient Evidence Retrieval.

    PubMed

    Afzal, Muhammad; Hussain, Maqbool; Ali, Taqdir; Hussain, Jamil; Khan, Wajahat Ali; Lee, Sungyoung; Kang, Byeong Ho

    2015-08-28

    Finding appropriate evidence to support clinical practices is always challenging, and the construction of a query to retrieve such evidence is a fundamental step. Typically, evidence is found using manual or semi-automatic methods, which are time-consuming and sometimes make it difficult to construct knowledge-based complex queries. To overcome the difficulty in constructing knowledge-based complex queries, we utilized the knowledge base (KB) of the clinical decision support system (CDSS), which has the potential to provide sufficient contextual information. To automatically construct knowledge-based complex queries, we designed methods to parse rule structure in KB of CDSS in order to determine an executable path and extract the terms by parsing the control structures and logic connectives used in the logic. The automatically constructed knowledge-based complex queries were executed on the PubMed search service to evaluate the results on the reduction of retrieved citations with high relevance. The average number of citations was reduced from 56,249 citations to 330 citations with the knowledge-based query construction approach, and relevance increased from 1 term to 6 terms on average. The ability to automatically retrieve relevant evidence maximizes efficiency for clinicians in terms of time, based on feedback collected from clinicians. This approach is generally useful in evidence-based medicine, especially in ambient assisted living environments where automation is highly important.

  5. Knowledge-Based Query Construction Using the CDSS Knowledge Base for Efficient Evidence Retrieval

    PubMed Central

    Afzal, Muhammad; Hussain, Maqbool; Ali, Taqdir; Hussain, Jamil; Khan, Wajahat Ali; Lee, Sungyoung; Kang, Byeong Ho

    2015-01-01

    Finding appropriate evidence to support clinical practices is always challenging, and the construction of a query to retrieve such evidence is a fundamental step. Typically, evidence is found using manual or semi-automatic methods, which are time-consuming and sometimes make it difficult to construct knowledge-based complex queries. To overcome the difficulty in constructing knowledge-based complex queries, we utilized the knowledge base (KB) of the clinical decision support system (CDSS), which has the potential to provide sufficient contextual information. To automatically construct knowledge-based complex queries, we designed methods to parse rule structure in KB of CDSS in order to determine an executable path and extract the terms by parsing the control structures and logic connectives used in the logic. The automatically constructed knowledge-based complex queries were executed on the PubMed search service to evaluate the results on the reduction of retrieved citations with high relevance. The average number of citations was reduced from 56,249 citations to 330 citations with the knowledge-based query construction approach, and relevance increased from 1 term to 6 terms on average. The ability to automatically retrieve relevant evidence maximizes efficiency for clinicians in terms of time, based on feedback collected from clinicians. This approach is generally useful in evidence-based medicine, especially in ambient assisted living environments where automation is highly important. PMID:26343669

  6. Near perfect light trapping in a 2D gold nanotrench grating at oblique angles of incidence and its application for sensing.

    PubMed

    Guo, Junpeng; Li, Zhitong; Guo, Hong

    2016-07-25

    A two-dimensional nanotrench cavity grating on a thick gold film was fabricated by using e-beam lithography. Optical reflection spectra from the fabricated device were measured at oblique angles of incidence for TE and TM polarizations. Near perfect light absorption was observed at different wavelengths for TE and TM polarizations at oblique angles of incidence. The peak absorption wavelength of TM polarization red-shifts significantly as angle of incidence increases. The peak absorption wavelength of TE polarization blue-shifts slightly as incident angle increases. Using finite-difference time-domain (FDTD) simulations, two orders of magnitude magnetic field enhancement was revealed inside nanotrenches, indicating strong light trapping inside the nanostructure. The fabricated device was investigated as a refractive index chemical sensor. It was found that sensitivity increases for TM polarization and decreases for TE polarization when angle of incidence increases from zero. PMID:27464175

  7. SLUDGE PARTICLE SEPAPATION EFFICIENCIES DURING SETTLER TANK RETRIEVAL INTO SCS-CON-230

    SciTech Connect

    DEARING JI; EPSTEIN M; PLYS MG

    2009-07-16

    The purpose of this document is to release, into the Hanford Document Control System, FA1/0991, Sludge Particle Separation Efficiencies for the Rectangular SCS-CON-230 Container, by M. Epstein and M. G. Plys, Fauske & Associates, LLC, June 2009. The Sludge Treatment Project (STP) will retrieve sludge from the 105-K West Integrated Water Treatment System (IWTS) Settler Tanks and transfer it to container SCS-CON-230 using the Settler Tank Retrieval System (STRS). The sludge will enter the container through two distributors. The container will have a filtration system that is designed to minimize the overflow of sludge fines from the container to the basin. FAI/09-91 was performed to quantify the effect of the STRS on sludge distribution inside of and overflow out of SCS-CON-230. Selected results of the analysis and a system description are discussed. The principal result of the analysis is that the STRS filtration system reduces the overflow of sludge from SCS-CON-230 to the basin by roughly a factor of 10. Some turbidity can be expected in the center bay where the container is located. The exact amount of overflow and subsequent turbidity is dependent on the density of the sludge (which will vary with location in the Settler Tanks) and the thermal gradient between the SCS-CON-230 and the basin. Attachment A presents the full analytical results. These results are applicable specifically to SCS-CON-230 and the STRS filtration system's expected operating duty cycles.

  8. Predicting performance on the Raven’s Matrices: The roles of associative learning and retrieval efficiency

    PubMed Central

    Lilienthal, Lindsey; Tamez, Elaine; Myerson, Joel; Hale, Sandra

    2013-01-01

    Previous studies have shown that performance on Williams and Pearlberg’s (2006) complex associative learning task is a good predictor of fluid intelligence. This task is similar in structure to that used in studying the fan effect (Anderson, 1974), as both tasks involve forming multiple associations and require retrieval in the face of interference. The purpose of the present study was to investigate the relations among complex associative learning, working memory, and fluid intelligence. Specifically, we asked whether retrieval efficiency, as measured by the fan effect, could account for the relation between complex associative learning and performance on Raven’s Advanced Progressive Matrices. Consistent with previous findings, complex associative learning predicted Raven’s performance, but the fan effect did not account for this relation. Notably, the learning phase of the fan effect task was significantly correlated with both complex associative learning and Raven’s performance, providing further support for the importance of learning as a predictor of fluid intelligence. PMID:24187609

  9. A safe and efficient method to retrieve mesenchymal stem cells from three-dimensional fibrin gels.

    PubMed

    Carrion, Bita; Janson, Isaac A; Kong, Yen P; Putnam, Andrew J

    2014-03-01

    Mesenchymal stem cells (MSCs) display multipotent characteristics that make them ideal for potential therapeutic applications. MSCs are typically cultured as monolayers on tissue culture plastic, but there is increasing evidence suggesting that they may lose their multipotency over time in vitro and eventually cease to retain any resemblance to in vivo resident MSCs. Three-dimensional (3D) culture systems that more closely recapitulate the physiological environment of MSCs and other cell types are increasingly explored for their capacity to support and maintain the cell phenotypes. In much of our own work, we have utilized fibrin, a natural protein-based material that serves as the provisional extracellular matrix during wound healing. Fibrin has proven to be useful in numerous tissue engineering applications and has been used clinically as a hemostatic material. Its rapid self-assembly driven by thrombin-mediated alteration of fibrinogen makes fibrin an attractive 3D substrate, in which cells can adhere, spread, proliferate, and undergo complex morphogenetic programs. However, there is a significant need for simple cost-effective methods to safely retrieve cells encapsulated within fibrin hydrogels to perform additional analyses or use the cells for therapy. Here, we present a safe and efficient protocol for the isolation of MSCs from 3D fibrin gels. The key ingredient of our successful extraction method is nattokinase, a serine protease of the subtilisin family that has a strong fibrinolytic activity. Our data show that MSCs recovered from 3D fibrin gels using nattokinase are not only viable but also retain their proliferative and multilineage potentials. Demonstrated for MSCs, this method can be readily adapted to retrieve any other cell type from 3D fibrin gel constructs for various applications, including expansion, bioassays, and in vivo implantation.

  10. A Safe and Efficient Method to Retrieve Mesenchymal Stem Cells from Three-Dimensional Fibrin Gels

    PubMed Central

    Carrion, Bita; Janson, Isaac A.; Kong, Yen P.

    2014-01-01

    Mesenchymal stem cells (MSCs) display multipotent characteristics that make them ideal for potential therapeutic applications. MSCs are typically cultured as monolayers on tissue culture plastic, but there is increasing evidence suggesting that they may lose their multipotency over time in vitro and eventually cease to retain any resemblance to in vivo resident MSCs. Three-dimensional (3D) culture systems that more closely recapitulate the physiological environment of MSCs and other cell types are increasingly explored for their capacity to support and maintain the cell phenotypes. In much of our own work, we have utilized fibrin, a natural protein-based material that serves as the provisional extracellular matrix during wound healing. Fibrin has proven to be useful in numerous tissue engineering applications and has been used clinically as a hemostatic material. Its rapid self-assembly driven by thrombin-mediated alteration of fibrinogen makes fibrin an attractive 3D substrate, in which cells can adhere, spread, proliferate, and undergo complex morphogenetic programs. However, there is a significant need for simple cost-effective methods to safely retrieve cells encapsulated within fibrin hydrogels to perform additional analyses or use the cells for therapy. Here, we present a safe and efficient protocol for the isolation of MSCs from 3D fibrin gels. The key ingredient of our successful extraction method is nattokinase, a serine protease of the subtilisin family that has a strong fibrinolytic activity. Our data show that MSCs recovered from 3D fibrin gels using nattokinase are not only viable but also retain their proliferative and multilineage potentials. Demonstrated for MSCs, this method can be readily adapted to retrieve any other cell type from 3D fibrin gel constructs for various applications, including expansion, bioassays, and in vivo implantation. PMID:23808842

  11. A novel method for efficient archiving and retrieval of biomedical images using MPEG-7

    NASA Astrophysics Data System (ADS)

    Meyer, Joerg; Pahwa, Ash

    2004-10-01

    Digital archiving and efficient retrieval of radiological scans have become critical steps in contemporary medical diagnostics. Since more and more images and image sequences (single scans or video) from various modalities (CT/MRI/PET/digital X-ray) are now available in digital formats (e.g., DICOM-3), hospitals and radiology clinics need to implement efficient protocols capable of managing the enormous amounts of data generated daily in a typical clinical routine. We present a method that appears to be a viable way to eliminate the tedious step of manually annotating image and video material for database indexing. MPEG-7 is a new framework that standardizes the way images are characterized in terms of color, shape, and other abstract, content-related criteria. A set of standardized descriptors that are automatically generated from an image is used to compare an image to other images in a database, and to compute the distance between two images for a given application domain. Text-based database queries can be replaced with image-based queries using MPEG-7. Consequently, image queries can be conducted without any prior knowledge of the keys that were used as indices in the database. Since the decoding and matching steps are not part of the MPEG-7 standard, this method also enables searches that were not planned by the time the keys were generated.

  12. Avoided resonance crossing and non-reciprocal nearly perfect absorption in plasmonic nanodisks with near-field and far-field couplings.

    PubMed

    Chang, Shih-Hui Gilbert; Sun, Chia-Yi

    2016-07-25

    Avoided resonance crossings (ARC) in plasmonic nanodisk structures due to near field or far field couplings were numerically demonstrated. Near field coupling in disk dimmer with both vertical or side-by-side arrangement leads to both energy and linewidth anti-crossing by varying one disk size across the other. Far field coupling in double layered disk arrays of extremely small gap size or gap size with Fabry Perot resonant condition close to the frequency selective surface (FSS) stopband center leads to non-reciprocal absorption spectrum as one disk size varying across the other. We observe linewidth anti-crossing but energy crossing of the absorption peak from different side illumination by varying either the size of one disk array or the gap in hetero disk arrays. The disappearing of Fabry-Perot resonant mode from one side illumination and the appearing of nonreciprocal nearly perfect absorption from the other side illumination are well explained by a FSS-Fabry-Perot model.

  13. "Near perfect" amphiphilic conetwork based on end-group cross-linking of polydimethylsiloxane triblock copolymer via atom transfer radical polymerization.

    PubMed

    Xu, Jianfeng; Qiu, Ming; Ma, Bomou; He, Chunju

    2014-09-10

    Novel amphiphilic conetworks (APCNs) with uniform channel size were synthesized through end-cross-linking of well-defined amphiphilic triblock copolymers via atom transfer radical polymerization (ATRP). A new ditelechelic polydimethylsiloxane macroinitiator was synthesized to initiate the polymerization of N,N-dimethylacrylamide. The resulting triblock copolymers show well-defined molecular weight with narrow polydisperisty, which are telechelic modified by allylamine and fully cross-linked with polyhydrosiloxanes through hydrosilylation. Transmission electron microscopy shows that the APCN has the behavior of microphase separation with small channel size and uniform phase domain. The resulting APCNs with idealized microstructure exhibit a combination of excellent properties, i.e., superhigh mechanical strength (4 ± 1 MPa) and elongation ratio (175 ± 25%), outstanding oxygen permeability (350 ± 150 barrers), a high water uptake property, and excellent biocompatibility, indicating that in this way, "near perfect" networks are obtained. These results are better than those reported in the literature, suggesting a promising semipermeable barrier for islet encapsulation in relative biomaterial fields.

  14. Nearly Perfect Spin Filter Based on a Wire of Half-Metallic (η5-C5H5)Ti (η8-C8H8)Ti Units

    NASA Astrophysics Data System (ADS)

    Zhu, Sicong; Fang, Jianming; Yao, Kailun; Wu, Yanqing

    2015-07-01

    Organic molecular devices show strong potential for future nanoelectronics applications, many of which require multifunction capability. Organometallic [(C5H5)Ti(C8H8)] n clusters are one of the few molecular material clusters that have been synthesized experimentally. Here we present a theoretical study of the spin-polarized transport on the clusters of [(C5H5)Ti(C8H8)] n by using nonequilibrium Green's functions combined with the density-functional theory. Results indicate that one-dimensional, organic (η5-C5H5)Ti (η8-C8H8)Ti wire has unique half-metallic properties with 100% spin polarization near the Fermi level in the ground state. We predict that finite-layer [(C5H5)Ti (C8H8)] n clusters coupled to gold electrodes exhibit a near-perfect spin-filter effect. Furthermore, due to the large spin coherence originated from its organic nature, these devices possess a spin-valve effect with large magnetoresistance. Our findings suggest that such a multifunctional molecular device is an excellent candidate for future molecule-based spintronic applications.

  15. A novel video recommendation system based on efficient retrieval of human actions

    NASA Astrophysics Data System (ADS)

    Ramezani, Mohsen; Yaghmaee, Farzin

    2016-09-01

    In recent years, fast growth of online video sharing eventuated new issues such as helping users to find their requirements in an efficient way. Hence, Recommender Systems (RSs) are used to find the users' most favorite items. Finding these items relies on items or users similarities. Though, many factors like sparsity and cold start user impress the recommendation quality. In some systems, attached tags are used for searching items (e.g. videos) as personalized recommendation. Different views, incomplete and inaccurate tags etc. can weaken the performance of these systems. Considering the advancement of computer vision techniques can help improving RSs. To this end, content based search can be used for finding items (here, videos are considered). In such systems, a video is taken from the user to find and recommend a list of most similar videos to the query one. Due to relating most videos to humans, we present a novel low complex scalable method to recommend videos based on the model of included action. This method has recourse to human action retrieval approaches. For modeling human actions, some interest points are extracted from each action and their motion information are used to compute the action representation. Moreover, a fuzzy dissimilarity measure is presented to compare videos for ranking them. The experimental results on HMDB, UCFYT, UCF sport and KTH datasets illustrated that, in most cases, the proposed method can reach better results than most used methods.

  16. Retrieval Practice Is an Efficient Method of Enhancing the Retention of Anatomy and Physiology Information

    ERIC Educational Resources Information Center

    Dobson, John L.

    2013-01-01

    Although a great deal of empirical evidence has indicated that retrieval practice is an effective means of promoting learning and memory, very few studies have investigated the strategy in the context of an actual class. The primary purpose of this study was to determine if a series of very brief retrieval quizzes could significantly improve the…

  17. Poor readers' retrieval mechanism: efficient access is not dependent on reading skill

    PubMed Central

    Johns, Clinton L.; Matsuki, Kazunaga; Van Dyke, Julie A.

    2015-01-01

    A substantial body of evidence points to a cue-based direct-access retrieval mechanism as a crucial component of skilled adult reading. We report two experiments aimed at examining whether poor readers are able to make use of the same retrieval mechanism. This is significant in light of findings that poor readers have difficulty retrieving linguistic information (e.g., Perfetti, 1985). Our experiments are based on a previous demonstration of direct-access retrieval in language processing, presented in McElree et al. (2003). Experiment 1 replicates the original result using an auditory implementation of the Speed-Accuracy Tradeoff (SAT) method. This finding represents a significant methodological advance, as it opens up the possibility of exploring retrieval speeds in non-reading populations. Experiment 2 provides evidence that poor readers do use a direct-access retrieval mechanism during listening comprehension, despite overall poorer accuracy and slower retrieval speeds relative to skilled readers. The findings are discussed with respect to hypotheses about the source of poor reading comprehension. PMID:26528212

  18. New state of nuclear matter: Nearly perfect fluid of quarks and gluons in heavy-ion collisions at RHIC energies. From charged particle density to jet quenching

    NASA Astrophysics Data System (ADS)

    Nouicer, R.

    2016-03-01

    This article reviews several important results from RHIC experiments and discusses their implications. They were obtained in a unique environment for studying QCD matter at temperatures and densities that exceed the limits wherein hadrons can exist as individual entities and raises to prominence the quark-gluon degrees of freedom. These findings are supported by major experimental observations via measuring of the bulk properties of particle production, particle ratios and chemical freeze-out conditions, and elliptic flow; followed by hard probe measurements: high- pT hadron suppression, dijet fragment azimuthal correlations, and heavy-flavor probes. These measurements are presented for particles of different species as a function of system sizes, collision centrality, and energy carried out in RHIC experiments. The results reveal that a dense, strongly interacting medium is created in central Au+Au collisions at sqrt{s_{NN}} = 200 GeV at RHIC. This revelation of a new state of nuclear matter has also been observed in measurements at the LHC. Further, the IP-Glasma model coupled with viscous hydrodynamic models, which assumes the formation of a QGP, reproduces well the experimental flow results from Au+Au at sqrt{s_{NN}} = 200 GeV. This implies that the fluctuations in the initial geometry state are important and the created medium behaves as a nearly perfect liquid of nuclear matter because it has an extraordinarily low ratio of shear viscosity to entropy density, η/s≈ 0.12. However, these discoveries are far from being fully understood. Furthermore, recent experimental results from RHIC and LHC in small p+A, d+ Au and 3He+Au collision systems provide brand new insight into the role of initial and final state effects. These have proven to be interesting and more surprising than originally anticipated; and could conceivably shed new light in our understanding of collective behavior in heavy-ion physics. Accordingly, the focus of the experiments at both

  19. A Semantic Rule-Based Framework for Efficient Retrieval of Educational Materials

    ERIC Educational Resources Information Center

    Mahmoudi, Maryam Tayefeh; Taghiyareh, Fattaneh; Badie, Kambiz

    2013-01-01

    Retrieving resources in an appropriate manner has a promising role in increasing the performance of educational support systems. A variety of works have been done to organize materials for educational purposes using tagging techniques. Despite the effectiveness of these techniques within certain domains, organizing resources in a way being…

  20. Using Taxonomic Indexing Trees to Efficiently Retrieve SCORM-Compliant Documents in e-Learning Grids

    ERIC Educational Resources Information Center

    Shih, Wen-Chung; Tseng, Shian-Shyong; Yang, Chao-Tung

    2008-01-01

    With the flourishing development of e-Learning, more and more SCORM-compliant teaching materials are developed by institutes and individuals in different sites. In addition, the e-Learning grid is emerging as an infrastructure to enhance traditional e-Learning systems. Therefore, information retrieval schemes supporting SCORM-compliant documents…

  1. Development of digital dashboard system for medical practice: maximizing efficiency of medical information retrieval and communication.

    PubMed

    Lee, Kee Hyuck; Yoo, Sooyoung; Shin, HoGyun; Baek, Rong-Min; Chung, Chin Youb; Hwang, Hee

    2013-01-01

    It is reported that digital dashboard systems in hospitals provide a user interface (UI) that can centrally manage and retrieve various information related to patients in a single screen, support the decision-making of medical professionals on a real time basis by integrating the scattered medical information systems and core work flows, enhance the competence and decision-making ability of medical professionals, and reduce the probability of misdiagnosis. However, the digital dashboard systems of hospitals reported to date have some limitations when medical professionals use them to generally treat inpatients, because those were limitedly used for the work process of certain departments or developed to improve specific disease-related indicators. Seoul National University Bundang Hospital developed a new concept of EMR system to overcome such limitations. The system allows medical professionals to easily access all information on inpatients and effectively retrieve important information from any part of the hospital by displaying inpatient information in the form of digital dashboard. In this study, we would like to introduce the structure, development methodology and the usage of our new concept.

  2. A Fine Balance of Synaptophysin Levels Underlies Efficient Retrieval of Synaptobrevin II to Synaptic Vesicles

    PubMed Central

    Gordon, Sarah L.; Harper, Callista B.; Smillie, Karen J.; Cousin, Michael A.

    2016-01-01

    Synaptobrevin II (sybII) is a vesicular soluble NSF attachment protein receptor (SNARE) protein that is essential for neurotransmitter release, and thus its correct trafficking to synaptic vesicles (SVs) is critical to render them fusion competent. The SV protein synaptophysin binds to sybII and facilitates its retrieval to SVs during endocytosis. Synaptophysin and sybII are the two most abundant proteins on SVs, being present in a 1:2 ratio. Synaptophysin and sybII are proposed to form a large multimeric complex, and the copy number of the proteins in this complex is also in a 1:2 ratio. We investigated the importance of this ratio between these proteins for the localisation and trafficking of sybII in central neurons. SybII was overexpressed in mouse hippocampal neurons at either 1.6 or 2.15–2.35-fold over endogenous protein levels, in the absence or presence of varying levels of synaptophysin. In the absence of exogenous synaptophysin, exogenous sybII was dispersed along the axon, trapped on the plasma membrane and retrieved slowly during endocytosis. Co-expression of exogenous synaptophysin rescued all of these defects. Importantly, the expression of synaptophysin at nerve terminals in a 1:2 ratio with sybII was sufficient to fully rescue normal sybII trafficking. These results demonstrate that the balance between synaptophysin and sybII levels is critical for the correct targeting of sybII to SVs and suggests that small alterations in synaptophysin levels might affect the localisation of sybII and subsequent presynaptic performance. PMID:26871701

  3. A Fine Balance of Synaptophysin Levels Underlies Efficient Retrieval of Synaptobrevin II to Synaptic Vesicles.

    PubMed

    Gordon, Sarah L; Harper, Callista B; Smillie, Karen J; Cousin, Michael A

    2016-01-01

    Synaptobrevin II (sybII) is a vesicular soluble NSF attachment protein receptor (SNARE) protein that is essential for neurotransmitter release, and thus its correct trafficking to synaptic vesicles (SVs) is critical to render them fusion competent. The SV protein synaptophysin binds to sybII and facilitates its retrieval to SVs during endocytosis. Synaptophysin and sybII are the two most abundant proteins on SVs, being present in a 1:2 ratio. Synaptophysin and sybII are proposed to form a large multimeric complex, and the copy number of the proteins in this complex is also in a 1:2 ratio. We investigated the importance of this ratio between these proteins for the localisation and trafficking of sybII in central neurons. SybII was overexpressed in mouse hippocampal neurons at either 1.6 or 2.15-2.35-fold over endogenous protein levels, in the absence or presence of varying levels of synaptophysin. In the absence of exogenous synaptophysin, exogenous sybII was dispersed along the axon, trapped on the plasma membrane and retrieved slowly during endocytosis. Co-expression of exogenous synaptophysin rescued all of these defects. Importantly, the expression of synaptophysin at nerve terminals in a 1:2 ratio with sybII was sufficient to fully rescue normal sybII trafficking. These results demonstrate that the balance between synaptophysin and sybII levels is critical for the correct targeting of sybII to SVs and suggests that small alterations in synaptophysin levels might affect the localisation of sybII and subsequent presynaptic performance.

  4. A new efficient data structure for storage and retrieval of multiple biosequences.

    PubMed

    Steinbiss, Sascha; Kurtz, Stefan

    2012-01-01

    Today's genome analysis applications require sequence representations allowing for fast access to their contents while also being memory-efficient enough to facilitate analyses of large-scale data. While a wide variety of sequence representations exist, lack of a generic implementation of efficient sequence storage has led to a plethora of poorly reusable or programming language-specific implementations. We present a novel, space-efficient data structure (GtEncseq) for storing multiple biological sequences of variable alphabet size, with customizable character transformations, wildcard support and an assortment of internal representations optimized for different distributions of wildcards and sequence lengths. For the human genome (3.1 gigabases, including 237 million wildcard characters) our representation requires only 2 + 8 × 10^-6bits per character. Implemented in C, our portable software implementation provides a variety of methods for random and sequential access to characters and substrings (including different reading directions) using an object-oriented interface. In addition, it includes access to metadata like sequence descriptions or character distributions. The library is extensible to be used from various scripting languages. GtEncseq is much more versatile than previous solutions, adding features that were previously unavailable. Benchmarks show that it is competitive with respect to space and time requirements. PMID:22084150

  5. Experimental study of the dependences of retrieval efficiencies on time delay between magneto-optical-trap being turned off and optical storage

    NASA Astrophysics Data System (ADS)

    Li-Rong, Chen; Zhong-Xiao, Xu; Ping, Li; Ya-Fei, Wen; Wei-Qing, Zeng; Yue-Long, Wu; Long, Tian; Shu-Jing, Li; Hai, Wang

    2016-02-01

    We report an experimental study of electromagnetically induced transparency (EIT)-based light storage in a cloud of cold atoms loaded into a magneto-optical-trap (MOT). After the MOT is turned off, the retrieval efficiencies of right- and left-circularly polarized signal light fields each as a function of storage time are measured for different time delays between MOT off and the storage event, respectively. The results show that in the delay ranging from 0.015 ms to 3.5 ms, the retrieval efficiency for a zero-storage time (0.2 μs) and the storage lifetime can exceed 15% and 1.4 ms, respectively. The measured results will provide important help for optimizing the storage of the polarized entanglement photons in cold atomic ensembles. Project supported by the National Basic Research Program of China (Grant No. 2010CB923103) and the National Natural Science Foundation of China (Grant Nos. 11475109, 11274211, and 60821004).

  6. Class of near-perfect coded apertures

    NASA Technical Reports Server (NTRS)

    Cannon, T. M.; Fenimore, E. E.

    1977-01-01

    Coded aperture imaging of gamma ray sources has long promised an improvement in the sensitivity of various detector systems. The promise has remained largely unfulfilled, however, for either one of two reasons. First, the encoding/decoding method produces artifacts, which even in the absence of quantum noise, restrict the quality of the reconstructed image. This is true of most correlation-type methods. Second, if the decoding procedure is of the deconvolution variety, small terms in the transfer function of the aperture can lead to excessive noise in the reconstructed image. It is proposed to circumvent both of these problems by use of a uniformly redundant array (URA) as the coded aperture in conjunction with a special correlation decoding method.

  7. Nearly perfect valley filter in silicene.

    PubMed

    Zhang, Qingtian; Chan, K S; Long, Mengqiu

    2016-02-10

    We demonstrate theoretically how a perfect valley filter can be obtained in silicene under the effects of a ferromagnetic stripe and an electric field perpendicular to silicene. A ferromagnetic stripe or an electric field alone can not generate any valley polarization in silicene, but a combination of them can make a perfect valley filter. Two configurations, one with magnetization of the ferromagnetic stripe being perpendicular to the silicene plane and one being parallel to the current direction, are considered. Our proposed device is useful for the realization of a valley beam filter in the development of valleytronic devices.

  8. Idea Retrieval.

    ERIC Educational Resources Information Center

    Shively, Daniel

    1988-01-01

    Discusses the need to retrieve ideas in addition to content retrieval by such means as classification, subject headings, and keywords. Three models for idea retrieval are described, and a new model is proposed which combines selection, a controlled vocabulary, and logical structure. (seven references) (CLB)

  9. Pseudo Relevance Feedback Using Fast XML Retrieval

    NASA Astrophysics Data System (ADS)

    Tanioka, Hiroki

    This paper reports the result of experimentation of our approach using the vector space model for retrieving large-scale XML data. The purposes of the experiments are to improve retrieval precision on the INitiative for the Evaluation of XML Retrieval (INEX) 2008 Adhoc Track, and to compare the retrieval time of our system to other systems on the INEX 2008 Efficiency Track. For the INEX 2007 Adhoc Track, we developed a system using a relative inverted-path (RIP) list and a Bottom-UP approach. The system achieved reasonable retrieval time for XML data. However the system has a room for improvement in terms of retrieval precision. So for INEX 2008, the system uses CAS titles and Pseudo Relevance Feedback (PRF) to improve retrieval precision.

  10. A Near Perfect Spin Balance (Measurement in Chaos)

    NASA Technical Reports Server (NTRS)

    Luntz, R. A.

    1997-01-01

    The stringent spin balance requirements arise from the predecessor of SSMIS, the SSMI. The SSMI sensor spinning portion weighed only 85 pounds and contained 7 channels of radiometric data. The Aerospace Corporation recommended to pass on the same requirements from the smaller SSMI to our larger SSMIS (with slight change for increased weight). The SSMIS spinning portion will weigh about 155 pounds and contain 24 channels of radiometeric data. The SSMIS, on orbit, spins a CCW direction at 31.6 RPM its own drive motor. The packaging of this SSMIS is unique, as it combines three sensor into one unit. This combination allows for concurrently reading data in one beam. The unit will have a polar orbit about 500 miles above the earths surface. One of the primary influences for our receipt of the follow-on contract for the next generation sensor, was the ability to package 24 channels of radiometeric data into about the some volume as its predecessor. The data from SSMIS will be used to measure the following: (1) Ocean surface wind speed, (2) Rain over land an ocean, (3) Cloud water over Ocean, (4) Soil moisture, (5) Ice Concentration, (6) Ice age, (7) Ice Edge and snow edge, (8) Water vapor over Ocean, (9) Surface type, (10) Snow water content, (11) Land surface Temperature, (12) Cloud amount over ocean.

  11. Properties of large nearly perfect crystals at very low temperatures

    NASA Technical Reports Server (NTRS)

    Davis, W.; Krack, K. R.; Richard, J. P.; Weber, J.

    1983-01-01

    A liquid helium cryostat of a size and construction unavailable commercially, was built for use in measuring the Q of several materials at milli-Kelvin temperatures. The design and testing of the cryostat is described as well as the design of the experiment vacuum chamber and adaptor for the dilution refrigerator insert. Theory, design, and testing are also discussed for the magnetic coils built to levitate the materials so as to isolate them and increase the measured Q. A four point suspension with capacitor end plates as the transducer was used to obtain preliminary Q measurements of 6061 aluminum alloy and single crystal silicon. Results are tabulated.

  12. Towards Near Perfect Crystals With Only Well-Characterized Imperfections

    PubMed Central

    Peiser, H. Steffen

    2001-01-01

    Throughout the past century NBS/NIST supported a great variety of research studies in crystallography where the aim was the highest attainable accuracy in measurements. While avoiding overlap with other papers in this volume, this article summarizes results from: 1) early work on crystallization as a method of purification, in contributions to sugar chemistry, and in solution growth of large crystals; 2) the NBS/ARPA Program of research on crystal growth and characterization; 3) the NBS Free-Radical Research Program; 4) the XRCD method as a direct path to relative atomic mass data and the fundamental physical constants; 5) the dynamical theory of x-ray diffraction; and 6) symmetry considerations such as are involved in the influence on crystals of mechanical stress or fields, and of point defect motion. PMID:27500069

  13. INFORMATION RETRIEVAL EXPERIMENT. FINAL REPORT.

    ERIC Educational Resources Information Center

    SELYE, HANS

    THIS REPORT IS A BRIEF REVIEW OF RESULTS OF AN EXPERIMENT TO DETERMINE THE INFORMATION RETRIEVAL EFFICIENCY OF A MANUAL SPECIALIZED INFORMATION SYSTEM BASED ON 700,000 DOCUMENTS IN THE FIELDS OF ENDOCRINOLOGY, STRESS, MAST CELLS, AND ANAPHYLACTOID REACTIONS. THE SYSTEM RECEIVES 30,000 PUBLICATIONS ANNUALLY. DETAILED INFORMATION IS REPRESENTED BY…

  14. Transuranic (TRU) Waste Phase I Retrieval Plan

    SciTech Connect

    MCDONALD, K.M.

    1999-08-27

    Phase I retrieval of post-1970 TRU wastes from burial ground 218-W-4C can be done in a safe, efficient, and cost-effective manner. Initiating TRU retrieval by retrieving uncovered drums from Trenches 1, 20, and 29, will allow retrieval to begin under the current SWBG safety authorization basis. The retrieval of buried drums from Trenches 1, 4, 20, and 29, which will require excavation, will commence once the uncovered drum are retrieved. This phased approach allows safety analysis for drum venting and drum module excavation to be completed and approved before the excavation proceeds. In addition, the lessons learned and the operational experience gained from the retrieval of uncovered drums can be applied to the more complicated retrieval of the buried drums. Precedents that have been set at SRS and LANL to perform retrieval without a trench cover, in the open air, should be followed. Open-air retrieval will result in significant cost savings over the original plans for Phase I retrieval (Project W-113). Based on LANL and SRS experience, open-air retrieval will have no adverse impacts to the environment or to the health and safety of workers or the public. Assaying the waste in the SWBG using a mobile assay system, will result in additional cost savings. It is expected that up to 50% of the suspect-TRU wastes will assay as LLW, allowing those waste to remain disposed of in the SWBG. Further processing, with its associated costs, will only occur to the portion of the waste that is verified to be TRU. Retrieval should be done, to the extent possible, under the current SWBG safety authorization basis as a normal part of SWBG operations. The use of existing personnel and existing procedures should be optimized. By working retrieval campaigns, typically during the slow months, it is easier to coordinate the availability of necessary operations personnel, and it is easier to coordinate the availability of a mobile assay vendor.

  15. The present status and problems in document retrieval system : document input type retrieval system

    NASA Astrophysics Data System (ADS)

    Inagaki, Hirohito

    The office-automation (OA) made many changes. Many documents were begun to maintained in an electronic filing system. Therefore, it is needed to establish efficient document retrieval system to extract useful information. Current document retrieval systems are using simple word-matching, syntactic-matching, semantic-matching to obtain high retrieval efficiency. On the other hand, the document retrieval systems using special hardware devices, such as ISSP, were developed for aiming high speed retrieval. Since these systems can accept a single sentence or keywords as input, it is difficult to explain searcher's request. We demonstrated document input type retrieval system, which can directly accept document as an input, and can search similar documents from document data-base.

  16. Analyzing Document Retrievability in Patent Retrieval Settings

    NASA Astrophysics Data System (ADS)

    Bashir, Shariq; Rauber, Andreas

    Most information retrieval settings, such as web search, are typically precision-oriented, i.e. they focus on retrieving a small number of highly relevant documents. However, in specific domains, such as patent retrieval or law, recall becomes more relevant than precision: in these cases the goal is to find all relevant documents, requiring algorithms to be tuned more towards recall at the cost of precision. This raises important questions with respect to retrievability and search engine bias: depending on how the similarity between a query and documents is measured, certain documents may be more or less retrievable in certain systems, up to some documents not being retrievable at all within common threshold settings. Biases may be oriented towards popularity of documents (increasing weight of references), towards length of documents, favour the use of rare or common words; rely on structural information such as metadata or headings, etc. Existing accessibility measurement techniques are limited as they measure retrievability with respect to all possible queries. In this paper, we improve accessibility measurement by considering sets of relevant and irrelevant queries for each document. This simulates how recall oriented users create their queries when searching for relevant information. We evaluate retrievability scores using a corpus of patents from US Patent and Trademark Office.

  17. EVA Retriever Demonstration

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The EVA retriever is demonstrated in the Manipulator Development Facility (MDF). The retriever moves on the air bearing table 'searching' for its target, in this case tools 'dropped' by astronauts on orbit.

  18. Connectionist Interaction Information Retrieval.

    ERIC Educational Resources Information Center

    Dominich, Sandor

    2003-01-01

    Discussion of connectionist views for adaptive clustering in information retrieval focuses on a connectionist clustering technique and activation spreading-based information retrieval model using the interaction information retrieval method. Presents theoretical as well as simulation results as regards computational complexity and includes…

  19. Challenges in Web Information Retrieval

    NASA Astrophysics Data System (ADS)

    Arora, Monika; Kanjilal, Uma; Varshney, Dinesh

    The major challenge in information access is the rich data available for information retrieval, evolved to provide principle approaches or strategies for searching. The search has become the leading paradigm to find the information on World Wide Web. For building the successful web retrieval search engine model, there are a number of challenges that arise at the different levels where techniques, such as Usenet, support vector machine are employed to have a significant impact. The present investigations explore the number of problems identified its level and related to finding information on web. This paper attempts to examine the issues by applying different methods such as web graph analysis, the retrieval and analysis of newsgroup postings and statistical methods for inferring meaning in text. We also discuss how one can have control over the vast amounts of data on web, by providing the proper address to the problems in innovative ways that can extremely improve on standard. The proposed model thus assists the users in finding the existing formation of data they need. The developed information retrieval model deals with providing access to information available in various modes and media formats and to provide the content is with facilitating users to retrieve relevant and comprehensive information efficiently and effectively as per their requirements. This paper attempts to discuss the parameters factors that are responsible for the efficient searching. These parameters can be distinguished in terms of important and less important based on the inputs that we have. The important parameters can be taken care of for the future extension or development of search engines

  20. Information retrieval for ecological syntheses.

    PubMed

    Bayliss, Helen R; Beyer, Fiona R

    2015-06-01

    Research syntheses are increasingly being conducted within the fields of ecology and environmental management. Information retrieval is crucial in any synthesis in identifying data for inclusion whilst potentially reducing biases in the dataset gathered, yet the nature of ecological information provides several challenges when compared with medicine that should be considered when planning and undertaking searches. We present ten recommendations for anyone considering undertaking information retrieval for ecological research syntheses that highlight the main differences with medicine and, if adopted, may help reduce biases in the dataset retrieved, increase search efficiency and improve reporting standards. They are as follows: (1) plan for information retrieval at an early stage, (2) identify and use sources of help, (3) clearly define the question to be addressed, (4) ensure that provisions for managing, recording and reporting the search are in place, (5) select an appropriate search type, (6) identify sources to be used, (7) identify limitations of the sources, (8) ensure that the search vocabulary is appropriate, (9) identify limits and filters that can help direct the search, and (10) test the strategy to ensure that it is realistic and manageable. These recommendations may be of value for other disciplines where search infrastructures are not yet sufficiently well developed.

  1. Antigen Retrieval Immunohistochemistry

    PubMed Central

    Shi, Shan-Rong; Shi, Yan; Taylor, Clive R.

    2011-01-01

    As a review for the 20th anniversary of publishing the antigen retrieval (AR) technique in this journal, the authors intend briefly to summarize developments in AR-immunohistochemistry (IHC)–based research and diagnostics, with particular emphasis on current challenges and future research directions. Over the past 20 years, the efforts of many different investigators have coalesced in extending the AR approach to all areas of anatomic pathology diagnosis and research and further have led to AR-based protein extraction techniques and tissue-based proteomics. As a result, formalin-fixed paraffin-embedded (FFPE) archival tissue collections are now seen as a literal treasure of materials for clinical and translational research to an extent unimaginable just two decades ago. Further research in AR-IHC is likely to focus on tissue proteomics, developing a more efficient protocol for protein extraction from FFPE tissue based on the AR principle, and combining the proteomics approach with AR-IHC to establish a practical, sophisticated platform for identifying and using biomarkers in personalized medicine. PMID:21339172

  2. Knowledge Retrieval Solutions.

    ERIC Educational Resources Information Center

    Khan, Kamran

    1998-01-01

    Excalibur RetrievalWare offers true knowledge retrieval solutions. Its fundamental technologies, Adaptive Pattern Recognition Processing and Semantic Networks, have capabilities for knowledge discovery and knowledge management of full-text, structured and visual information. The software delivers a combination of accuracy, extensibility,…

  3. RETRIEVAL EVENTS EVALUATION

    SciTech Connect

    T. Wilson

    1999-11-12

    The purpose of this analysis is to evaluate impacts to the retrieval concept presented in the Design Analysis ''Retrieval Equipment and Strategy'' (Reference 6), from abnormal events based on Design Basis Events (DBE) and Beyond Design Basis Events (BDBE) as defined in two recent analyses: (1) DBE/Scenario Analysis for Preclosure Repository Subsurface Facilities (Reference 4); and (2) Preliminary Preclosure Design Basis Event Calculations for the Monitored Geologic Repository (Reference 5) The objective of this task is to determine what impacts the DBEs and BDBEs have on the equipment developed for retrieval. The analysis lists potential impacts and recommends changes to be analyzed in subsequent design analyses for developed equipment, or recommend where additional equipment may be needed, to allow retrieval to be performed in all DBE or BDBE situations. This analysis supports License Application design and therefore complies with the requirements of Systems Description Document input criteria comparison as presented in Section 7, Conclusions. In addition, the analysis discusses the impacts associated with not using concrete inverts in the emplacement drifts. The ''Retrieval Equipment and Strategy'' analysis was based on a concrete invert configuration in the emplacement drift. The scope of the analysis, as presented in ''Development Plan for Retrieval Events Evaluation'' (Reference 3) includes evaluation and criteria of the following: Impacts to retrieval from the emplacement drift based on DBE/BDBEs, and changes to the invert configuration for the preclosure period. Impacts to retrieval from the main drifts based on DBE/BDBEs for the preclosure period.

  4. Retrieval of Emotional Memories

    ERIC Educational Resources Information Center

    Buchanan, Tony W.

    2007-01-01

    Long-term memories are influenced by the emotion experienced during learning as well as by the emotion experienced during memory retrieval. The present article reviews the literature addressing the effects of emotion on retrieval, focusing on the cognitive and neurological mechanisms that have been revealed. The reviewed research suggests that the…

  5. Indexing and retrieval of MPEG compressed video

    NASA Astrophysics Data System (ADS)

    Kobla, Vikrant; Doermann, David S.

    1998-04-01

    To keep pace with the increased popularity of digital video as an archival medium, the development of techniques for fast and efficient analysis of ideo streams is essential. In particular, solutions to the problems of storing, indexing, browsing, and retrieving video data from large multimedia databases are necessary to a low access to these collections. Given that video is often stored efficiently in a compressed format, the costly overhead of decompression can be reduced by analyzing the compressed representation directly. In earlier work, we presented compressed domain parsing techniques which identified shots, subshots, and scenes. In this article, we present efficient key frame selection, feature extraction, indexing, and retrieval techniques that are directly applicable to MPEG compressed video. We develop a frame type independent representation which normalizes spatial and temporal features including frame type, frame size, macroblock encoding, and motion compensation vectors. Features for indexing are derived directly from this representation and mapped to a low- dimensional space where they can be accessed using standard database techniques. Spatial information is used as primary index into the database and temporal information is used to rank retrieved clips and enhance the robustness of the system. The techniques presented enable efficient indexing, querying, and retrieval of compressed video as demonstrated by our system which typically takes a fraction of a second to retrieve similar video scenes from a database, with over 95 percent recall.

  6. Semantic-based surveillance video retrieval.

    PubMed

    Hu, Weiming; Xie, Dan; Fu, Zhouyu; Zeng, Wenrong; Maybank, Steve

    2007-04-01

    Visual surveillance produces large amounts of video data. Effective indexing and retrieval from surveillance video databases are very important. Although there are many ways to represent the content of video clips in current video retrieval algorithms, there still exists a semantic gap between users and retrieval systems. Visual surveillance systems supply a platform for investigating semantic-based video retrieval. In this paper, a semantic-based video retrieval framework for visual surveillance is proposed. A cluster-based tracking algorithm is developed to acquire motion trajectories. The trajectories are then clustered hierarchically using the spatial and temporal information, to learn activity models. A hierarchical structure of semantic indexing and retrieval of object activities, where each individual activity automatically inherits all the semantic descriptions of the activity model to which it belongs, is proposed for accessing video clips and individual objects at the semantic level. The proposed retrieval framework supports various queries including queries by keywords, multiple object queries, and queries by sketch. For multiple object queries, succession and simultaneity restrictions, together with depth and breadth first orders, are considered. For sketch-based queries, a method for matching trajectories drawn by users to spatial trajectories is proposed. The effectiveness and efficiency of our framework are tested in a crowded traffic scene. PMID:17405446

  7. Using ontology for domain specific information retrieval

    NASA Astrophysics Data System (ADS)

    Shashirekha, H. L.; Murali, S.; Nagabhushan, P.

    2010-02-01

    This paper presents a system for retrieving information from a domain specific document collection made up of data rich unnatural language text documents. Instead of conventional keyword based retrieval, our system makes use of domain ontology to retrieve the information from a collection of documents. The system addresses the problem of representing unnatural language text documents and constructing a classifier model that helps in the efficient retrieval of relevant information. Query to this system may be either the key phrases in terms of concepts or a domain specific unnatural language text document. The classifier used in this system can also be used to assign multiple labels to the previously unseen text document belonging to the same domain. An empirical evaluation of the system is conducted on the domain of text documents describing the classified matrimonial advertisements to determine its performance.

  8. Topological Aspects of Information Retrieval.

    ERIC Educational Resources Information Center

    Egghe, Leo; Rousseau, Ronald

    1998-01-01

    Discusses topological aspects of theoretical information retrieval, including retrieval topology; similarity topology; pseudo-metric topology; document spaces as topological spaces; Boolean information retrieval as a subsystem of any topological system; and proofs of theorems. (LRW)

  9. Retrieval options study

    SciTech Connect

    Not Available

    1980-03-01

    This Retrieval Options Study is part of the systems analysis activities of the Office of Nuclear Waste Isolation to develop the scientific and technological bases for radioactive waste repositories in various geologic media. The study considers two waste forms, high level waste and spent fuel, and defines various classes of waste retrieval and recovery. A methodology and data base are developed which allow the relative evaluation of retrieval and recovery costs and the following technical criteria: safety; technical feasibility; ease of retrieval; probable intact retrieval time; safeguards; monitoring; criticality; and licensability. A total of 505 repository options are defined and the cost and technical criteria evaluated utilizing a combination of facts and engineering judgments. The repositories evaluated are selected combinations of the following parameters: Geologic Media (salt, granite, basalt, shale); Retrieval Time after Emplacement (5 and 25 years); Emplacement Design (nominal hole, large hole, carbon steel canister, corrosion resistant canister, backfill in hole, nominal sleeves, thick wall sleeves); Emplacement Configuration (single vertical, multiple vertical, single horizontal, multiple horizontal, vaults; Thermal Considerations; (normal design, reduced density, once-through ventilation, recirculated ventilation); Room Backfill; (none, run-of-mine, early, 5 year delay, 25 year delay, decommissioned); and Rate of Retrieval; (same as emplacement, variably slower depending on repository/canister condition).

  10. Retrieval medicine: a review and guide for UK practitioners. Part 2: safety in patient retrieval systems

    PubMed Central

    Hearns, S; Shirley, P J

    2006-01-01

    Retrieval and transfer of critically ill and injured patients is a high risk activity. Risk can be minimised with robust safety and clinical governance systems in place. This article describes the various governance systems that can be employed to optimise safety and efficiency in retrieval services. These include operating procedure development, equipment management, communications procedures, crew resource management, significant event analysis, audit and training. PMID:17130608

  11. Retrieving Patent Information Online

    ERIC Educational Resources Information Center

    Kaback, Stuart M.

    1978-01-01

    This paper discusses patent information retrieval from online files in terms of types of questions, file contents, coverage, timeliness, and other file variations. CLAIMS, Derwent, WPI, APIPAT and Chemical Abstracts Service are described. (KP)

  12. Information retrieval system

    NASA Technical Reports Server (NTRS)

    Berg, R. F.; Holcomb, J. E.; Kelroy, E. A.; Levine, D. A.; Mee, C., III

    1970-01-01

    Generalized information storage and retrieval system capable of generating and maintaining a file, gathering statistics, sorting output, and generating final reports for output is reviewed. File generation and file maintenance programs written for the system are general purpose routines.

  13. Retrievability Strategy Report

    SciTech Connect

    Gehner, P; Gilstrap, O J; Memory, R D; Wagner, R C

    1997-04-30

    Section 122 of the ''Nuclear Waste Policy Act'' requires that a repository be designed and constructed to permit retrieval of any spent fuel placed in such repository, during an appropriate period of operation of the facility, for one of these reasons: (1) to protect public health and safety, or the environment; and (2) to permit the recovery of the economically valuable contents of such spent fuel. The Act also requires the Secretary to specify an appropriate period of retrievability at the time of the design of a repository. The Secretary has not yet defined any such period. However, the Nuclear Regulatory Commission, in the Code of Federal Regulations Title 10 Part 60.111, requires the design of a geologic repository operations area to allow the retrieval of any or all waste on a reasonable schedule starting at any time up to 50 years after waste operations are initiated. NRC describes a reasonable schedule as one that would permit retrieval in about the same time as it took to construct the repository and emplace the waste. Based on the existing conceptual repository and waste package design and analysis, the Yucca Mountain Project described retrieval operations under normal and abnormal conditions in the 1988 ''Site Characterization Plan (SCP)'' document. In 1991, under the same design assumptions, the Project issued a ''Retrieval Strategy Report for a Potential High-Level Nuclear Waste Repository''. Both the conceptual design of the waste package and the emplacement methods have since changed significantly. This report presents the results of a study to determine whether and to what degree these design and other changes require a revision of the retrieval strategy and, if they do, to recommend a revised strategy. The aim of such a revised strategy was to inform decision makers on how to proceed with design to allow retrievability.

  14. Online medication history retrieval.

    PubMed

    Herdman, Bruce W; Varghese, Sandy R; Domer-Shank, Reed Bosch

    2015-01-01

    The difficulty of obtaining accurate medication history from inmates at the time of incarceration is daunting. This article summarizes the success of a large urban jail in the use of online data to identify medication history upon incarceration. This article describes the scope of available prescription data, the implementation of online retrieval, system limitations, planned improvements, and suggestions of additional applications of online retrieval services.

  15. Highly retrievable spin-wave-photon entanglement source.

    PubMed

    Yang, Sheng-Jun; Wang, Xu-Jie; Li, Jun; Rui, Jun; Bao, Xiao-Hui; Pan, Jian-Wei

    2015-05-29

    Entanglement between a single photon and a quantum memory forms the building blocks for a quantum repeater and quantum network. Previous entanglement sources are typically with low retrieval efficiency, which limits future larger-scale applications. Here, we report a source of highly retrievable spin-wave-photon entanglement. Polarization entanglement is created through interaction of a single photon with an ensemble of atoms inside a low-finesse ring cavity. The cavity is engineered to be resonant for dual spin-wave modes, which thus enables efficient retrieval of the spin-wave qubit. An intrinsic retrieval efficiency up to 76(4)% has been observed. Such a highly retrievable atom-photon entanglement source will be very useful in future larger-scale quantum repeater and quantum network applications.

  16. Exploiting salient semantic analysis for information retrieval

    NASA Astrophysics Data System (ADS)

    Luo, Jing; Meng, Bo; Quan, Changqin; Tu, Xinhui

    2016-11-01

    Recently, many Wikipedia-based methods have been proposed to improve the performance of different natural language processing (NLP) tasks, such as semantic relatedness computation, text classification and information retrieval. Among these methods, salient semantic analysis (SSA) has been proven to be an effective way to generate conceptual representation for words or documents. However, its feasibility and effectiveness in information retrieval is mostly unknown. In this paper, we study how to efficiently use SSA to improve the information retrieval performance, and propose a SSA-based retrieval method under the language model framework. First, SSA model is adopted to build conceptual representations for documents and queries. Then, these conceptual representations and the bag-of-words (BOW) representations can be used in combination to estimate the language models of queries and documents. The proposed method is evaluated on several standard text retrieval conference (TREC) collections. Experiment results on standard TREC collections show the proposed models consistently outperform the existing Wikipedia-based retrieval methods.

  17. RETRIEVAL & TREATMENT OF HANFORD TANK WASTE

    SciTech Connect

    EACKER, J.A.; SPEARS, J.A.; STURGES, M.H.; MAUSS, B.M.

    2006-01-20

    The Hanford Tank Farms contain 53 million gal of radioactive waste accumulated during over 50 years of operations. The waste is stored in 177 single-shell and double-shell tanks in the Hanford 200 Areas. The single-shell tanks were put into operation from the early 1940s through the 1960s with wastes received from several generations of processing facilities for the recovery of plutonium and uranium, and from laboratories and other ancillary facilities. The overall hanford Tank Farm system represents one of the largest nuclear legacies in the world driving towards completion of retrieval and treatment in 2028 and the associated closure activity completion by 2035. Remote operations, significant radiation/contamination levels, limited access, and old facilities are just some of the challenges faced by retrieval and treatment systems. These systems also need to be able to successfully remove 99% or more of the waste, and support waste treatment, and tank closure. The Tank Farm retrieval program has ramped up dramatically in the past three years with design, fabrication, installation, testing, and operations ongoing on over 20 of the 149 single-shell tanks. A variety of technologies are currently being pursued to retrieve different waste types, applications, and to help establish a baseline for recovery/operational efficiencies. The paper/presentation describes the current status of retrieval system design, fabrication, installation, testing, readiness, and operations, including: (1) Saltcake removal progress in Tanks S-102, S-109, and S-112 using saltcake dissolution, modified sluicing, and high pressure water lancing techniques; (2) Sludge vacuum retrieval experience from Tanks C-201, C-202, C-203, and C-204; (3) Modified sluicing experience in Tank C-103; (4) Progress on design and installation of the mobile retrieval system for sludge in potentially leaking single-shell tanks, particularly Tank C-101; and (5) Ongoing installation of various systems in the next

  18. An Intelligent System for Document Retrieval in Distributed Office Environments.

    ERIC Educational Resources Information Center

    Mukhopadhyay, Uttam; And Others

    1986-01-01

    MINDS (Multiple Intelligent Node Document Servers) is a distributed system of knowledge-based query engines for efficiently retrieving multimedia documents in an office environment of distributed workstations. By learning document distribution patterns and user interests and preferences during system usage, it customizes document retrievals for…

  19. Retrieval with gene queries

    PubMed Central

    Sehgal, Aditya K; Srinivasan, Padmini

    2006-01-01

    Background Accuracy of document retrieval from MEDLINE for gene queries is crucially important for many applications in bioinformatics. We explore five information retrieval-based methods to rank documents retrieved by PubMed gene queries for the human genome. The aim is to rank relevant documents higher in the retrieved list. We address the special challenges faced due to ambiguity in gene nomenclature: gene terms that refer to multiple genes, gene terms that are also English words, and gene terms that have other biological meanings. Results Our two baseline ranking strategies are quite similar in performance. Two of our three LocusLink-based strategies offer significant improvements. These methods work very well even when there is ambiguity in the gene terms. Our best ranking strategy offers significant improvements on three different kinds of ambiguities over our two baseline strategies (improvements range from 15.9% to 17.7% and 11.7% to 13.3% depending on the baseline). For most genes the best ranking query is one that is built from the LocusLink (now Entrez Gene) summary and product information along with the gene names and aliases. For others, the gene names and aliases suffice. We also present an approach that successfully predicts, for a given gene, which of these two ranking queries is more appropriate. Conclusion We explore the effect of different post-retrieval strategies on the ranking of documents returned by PubMed for human gene queries. We have successfully applied some of these strategies to improve the ranking of relevant documents in the retrieved sets. This holds true even when various kinds of ambiguity are encountered. We feel that it would be very useful to apply strategies like ours on PubMed search results as these are not ordered by relevance in any way. This is especially so for queries that retrieve a large number of documents. PMID:16630348

  20. Late removal of retrievable caval filters.

    PubMed

    von Segesser, Ludwig K; Ferrari, Enrico; Tozzi, Piergiorgio; Abdel-Sayed, Saad; Berdajs, Denis

    2014-01-01

    devices should be removed early on, and replaced if indicated with a device which is both, efficient and retrievable.

  1. Late removal of retrievable caval filters.

    PubMed

    von Segesser, Ludwig K; Ferrari, Enrico; Tozzi, Piergiorgio; Abdel-Sayed, Saad; Berdajs, Denis

    2014-01-01

    devices should be removed early on, and replaced if indicated with a device which is both, efficient and retrievable. PMID:25375823

  2. A content-based news video retrieval system: NVRS

    NASA Astrophysics Data System (ADS)

    Liu, Huayong; He, Tingting

    2009-10-01

    This paper focus on TV news programs and design a content-based news video browsing and retrieval system, NVRS, which is convenient for users to fast browsing and retrieving news video by different categories such as political, finance, amusement, etc. Combining audiovisual features and caption text information, the system automatically segments a complete news program into separate news stories. NVRS supports keyword-based news story retrieval, category-based news story browsing and generates key-frame-based video abstract for each story. Experiments show that the method of story segmentation is effective and the retrieval is also efficient.

  3. A semantic medical multimedia retrieval approach using ontology information hiding.

    PubMed

    Guo, Kehua; Zhang, Shigeng

    2013-01-01

    Searching useful information from unstructured medical multimedia data has been a difficult problem in information retrieval. This paper reports an effective semantic medical multimedia retrieval approach which can reflect the users' query intent. Firstly, semantic annotations will be given to the multimedia documents in the medical multimedia database. Secondly, the ontology that represented semantic information will be hidden in the head of the multimedia documents. The main innovations of this approach are cross-type retrieval support and semantic information preservation. Experimental results indicate a good precision and efficiency of our approach for medical multimedia retrieval in comparison with some traditional approaches.

  4. Science information systems: Archive, access, and retrieval

    NASA Technical Reports Server (NTRS)

    Campbell, William J.

    1991-01-01

    The objective of this research is to develop technology for the automated characterization and interactive retrieval and visualization of very large, complex scientific data sets. Technologies will be developed for the following specific areas: (1) rapidly archiving data sets; (2) automatically characterizing and labeling data in near real-time; (3) providing users with the ability to browse contents of databases efficiently and effectively; (4) providing users with the ability to access and retrieve system independent data sets electronically; and (5) automatically alerting scientists to anomalies detected in data.

  5. Retrieval Studies with LIDORT

    NASA Technical Reports Server (NTRS)

    Bhartia, P. K. (Technical Monitor); Spurr, Robert J. D.; Chance, K. V.

    2003-01-01

    This short program of LIDORT-based research in atmospheric trace gas retrieval was conducted over the 1 year period 01 July 2002 to 30 June 2003. After consultation with the NASA reporting officer, the first of the two original proposal activities (development of a direct-fitting total O3 column retrieval algorithm with operational capability for GOME data) was replaced by other tasks. The three activities addressed were: (1) Sensitivity studies for column and profile retrieval of NO2 distributions from a new generation of multi-axis ground-based spectrometers; (2) use of the LIDORT-RRS model to determine the effect of inelastic rotational Raman scattering at SBUV wavelengths; (3) an examination of ozone profile weighting functions in the presence of optically thick tropospheric clouds.

  6. A diagram retrieval method with multi-label learning

    NASA Astrophysics Data System (ADS)

    Fu, Songping; Lu, Xiaoqing; Liu, Lu; Qu, Jingwei; Tang, Zhi

    2015-01-01

    In recent years, the retrieval of plane geometry figures (PGFs) has attracted increasing attention in the fields of mathematics education and computer science. However, the high cost of matching complex PGF features leads to the low efficiency of most retrieval systems. This paper proposes an indirect classification method based on multi-label learning, which improves retrieval efficiency by reducing the scope of compare operation from the whole database to small candidate groups. Label correlations among PGFs are taken into account for the multi-label classification task. The primitive feature selection for multi-label learning and the feature description of visual geometric elements are conducted individually to match similar PGFs. The experiment results show the competitive performance of the proposed method compared with existing PGF retrieval methods in terms of both time consumption and retrieval quality.

  7. Information Retrieval Techniques.

    ERIC Educational Resources Information Center

    Kantor, Paul B.

    1994-01-01

    Identifies current trends in the automation of indexing, of information retrieval, and of interaction between the system and the users. Topics discussed include location, navigation, and indexing; digital libraries; matching documents to queries; weight of concepts; query structure, including fuzzy sets; algorithms; stemming; clustering; users'…

  8. Online Information Retrieval Bibliography

    ERIC Educational Resources Information Center

    Hawkins, Donald T.

    1978-01-01

    This is the first update of the bibliography on online information retrieval that was published as a supplement to Vol. 1 of this journal. Entries are divided into seven sections; within each section, they are listed alphabetically by author. Permuted titled (KWIC) and author indexes are included. (Author/JPF)

  9. Music Information Retrieval.

    ERIC Educational Resources Information Center

    Downie, J. Stephen

    2003-01-01

    Identifies MIR (Music Information Retrieval) computer system problems, historic influences, current state-of-the-art, and future MIR solutions through an examination of the multidisciplinary approach to MIR. Highlights include pitch; temporal factors; harmonics; tone; editorial, textual, and bibliographic facets; multicultural factors; locating…

  10. Information Retrieval by Television.

    ERIC Educational Resources Information Center

    Billowes, C. A.

    1968-01-01

    Bell Canada, the Public School and Collegiate Institute Boards of Ottawa, and the Ontario Institute for Studies in Education are collaborating on an educational television project which will provide a retrieval system that can supply any given program at any time under the control of the classroom teacher. Four schools in Ottawa will participate…

  11. Collaborative Information Retrieval.

    ERIC Educational Resources Information Center

    Bruce, Harry; Fidel, Raya

    1999-01-01

    Researchers from the University of Washington, Microsoft Research, Boeing, and Risoe National Laboratory in Denmark have embarked on a project to explore the manifestations of Collaborative Information Retrieval (CIR) in work settings and to propose technological innovations and organizational changes that can support, facilitate, and improve CIR.…

  12. Feedback in Information Retrieval.

    ERIC Educational Resources Information Center

    Spink, Amanda; Losee, Robert M.

    1996-01-01

    As Information Retrieval (IR) has evolved, it has become a highly interactive process, rooted in cognitive and situational contexts. Consequently the traditional cybernetic-based IR model does not suffice for interactive IR or the human approach to IR. Reviews different views of feedback in IR and their relationship to cybernetic and social…

  13. Retrieving Product Documentation Online.

    ERIC Educational Resources Information Center

    Racine, Sam J.; Crandall, Irving B.

    2001-01-01

    Discusses demands users face when searching for information in online libraries of product documentation. Demonstrates how physical libraries provide a helpful metaphor for design. Offers heuristics and a conceptual prototype for facilitating electronic document retrieval. Argues that the search form itself should communicate the way materials are…

  14. Multimedia Document Retrieval.

    ERIC Educational Resources Information Center

    Ozkarahan, Esen

    1995-01-01

    This study develops an integrated conceptual representation scheme for multimedia documents that are viewed to comprise an object-oriented database; the necessary abstractions for the conceptual model and extensions to the relational model used as the search structure; a retrieval model that includes associative, semantic and media-specific…

  15. Multiple image encryption by phase retrieval

    NASA Astrophysics Data System (ADS)

    Di, Hong; Kang, Yanmei; Liu, Yueqin; Zhang, Xin

    2016-07-01

    Multiple image encryption (MIE) was proposed to increase the efficiency of encrypting images by processing several images simultaneously. Because of the advantage of optical technology in processing twodimensional images at high throughput, MIE has been significantly improved by use of methods originating from optics. Phase retrieval was the process of algorithmically finding solutions to the phase loss problem due to light detectors only capturing the intensity. It was to retrieve phase information for the determination of a structure from diffraction data. Error-reduction algorithm is a typical phase retrieval method. Here, we employ it to illustrate that methods in phase retrieval are able to encrypt multiple images and compress them into encrypted data simultaneously. Moreover, the decryption is also designed to handle multiple images at the same time. The whole process including both the encryption and decryption is proposed to improve MIE with respect to the compression and efficiency. The feasibility and encryption of the MIE scheme is demonstrated with encryption experiments under Gaussian white noise and unauthorized access.

  16. Semantic-Aware Co-Indexing for Image Retrieval.

    PubMed

    Zhang, Shiliang; Yang, Ming; Wang, Xiaoyu; Lin, Yuanqing; Tian, Qi

    2015-12-01

    In content-based image retrieval, inverted indexes allow fast access to database images and summarize all knowledge about the database. Indexing multiple clues of image contents allows retrieval algorithms search for relevant images from different perspectives, which is appealing to deliver satisfactory user experiences. However, when incorporating diverse image features during online retrieval, it is challenging to ensure retrieval efficiency and scalability. In this paper, for large-scale image retrieval, we propose a semantic-aware co-indexing algorithm to jointly embed two strong cues into the inverted indexes: 1) local invariant features that are robust to delineate low-level image contents, and 2) semantic attributes from large-scale object recognition that may reveal image semantic meanings. Specifically, for an initial set of inverted indexes of local features, we utilize semantic attributes to filter out isolated images and insert semantically similar images to this initial set. Encoding these two distinct and complementary cues together effectively enhances the discriminative capability of inverted indexes. Such co-indexing operations are totally off-line and introduce small computation overhead to online retrieval, because only local features but no semantic attributes are employed for the query. Hence, this co-indexing is different from existing image retrieval methods fusing multiple features or retrieval results. Extensive experiments and comparisons with recent retrieval methods manifest the competitive performance of our method. PMID:26539859

  17. Semantic-Aware Co-Indexing for Image Retrieval.

    PubMed

    Zhang, Shiliang; Yang, Ming; Wang, Xiaoyu; Lin, Yuanqing; Tian, Qi

    2015-12-01

    In content-based image retrieval, inverted indexes allow fast access to database images and summarize all knowledge about the database. Indexing multiple clues of image contents allows retrieval algorithms search for relevant images from different perspectives, which is appealing to deliver satisfactory user experiences. However, when incorporating diverse image features during online retrieval, it is challenging to ensure retrieval efficiency and scalability. In this paper, for large-scale image retrieval, we propose a semantic-aware co-indexing algorithm to jointly embed two strong cues into the inverted indexes: 1) local invariant features that are robust to delineate low-level image contents, and 2) semantic attributes from large-scale object recognition that may reveal image semantic meanings. Specifically, for an initial set of inverted indexes of local features, we utilize semantic attributes to filter out isolated images and insert semantically similar images to this initial set. Encoding these two distinct and complementary cues together effectively enhances the discriminative capability of inverted indexes. Such co-indexing operations are totally off-line and introduce small computation overhead to online retrieval, because only local features but no semantic attributes are employed for the query. Hence, this co-indexing is different from existing image retrieval methods fusing multiple features or retrieval results. Extensive experiments and comparisons with recent retrieval methods manifest the competitive performance of our method.

  18. Language Processing in Information Retrieval.

    ERIC Educational Resources Information Center

    Doszkocs, Tamase

    1986-01-01

    Examines role and contributions of natural-language processing in information retrieval and artificial intelligence research in context of large operational information retrieval systems and services. State-of-the-art information retrieval systems combining the functional capabilities of conventional inverted file term adjacency approach with…

  19. DORS: DDC Online Retrieval System.

    ERIC Educational Resources Information Center

    Liu, Songqiao; Svenonius, Elaine

    1991-01-01

    Describes the Dewey Online Retrieval System (DORS), which was developed at the University of California, Los Angeles (UCLA), to experiment with classification-based search strategies in online catalogs. Classification structures in automated information retrieval are discussed; and specifications for a classification retrieval interface are…

  20. A Visual Information Retrieval Tool.

    ERIC Educational Resources Information Center

    Zhang, Jin

    2000-01-01

    Discussion of visualization for information retrieval, that transforms unseen internal semantic representation of a document collection into visible geometric displays, focuses on DARE (Distance Angle Retrieval Environment). Highlights include expression of information need; interpretation and manipulation of information retrieval models; ranking…

  1. Practical quantum retrieval games

    NASA Astrophysics Data System (ADS)

    Arrazola, Juan Miguel; Karasamanis, Markos; Lütkenhaus, Norbert

    2016-06-01

    Complex cryptographic protocols are often constructed from simpler building blocks. In order to advance quantum cryptography, it is important to study practical building blocks that can be used to develop new protocols. An example is quantum retrieval games (QRGs), which have broad applicability and have already been used to construct quantum money schemes. In this work, we introduce a general construction of quantum retrieval games based on the hidden matching problem and show how they can be implemented in practice using available technology. More precisely, we provide a general method to construct (1-out-of-k ) QRGs, proving that their cheating probabilities decrease exponentially in k . In particular, we define QRGs based on coherent states of light, which can be implemented even in the presence of experimental imperfections. Our results constitute a tool in the arsenal of the practical quantum cryptographer.

  2. REMOTE RETRIEVING TOOL

    DOEpatents

    Fromm, L.W. Jr.

    1958-08-19

    A retrieving tool is described to securely grasp an object for emplacement in, or withdrawal from, an elongated tube. The object is grasped by hooks actuated by a wedge and cann mechanism. The mechanism on the end of a long rodlike structure is controlled by levers or bars at the access end of the tube. This device is particularly useful for positioning fuel elements within a reactor core.

  3. Magnetic junk retriever

    SciTech Connect

    Moseley, M.D.

    1980-10-07

    An improved magnetic junk retriever arranged to magnetize a drill bit just prior to its removal from the bottom of the well bore. A wound, electromagnet subassembly is connected between the drill bit and the drill collar. A battery-pack tool is used to energize the electromagnet by lowering the tool through the bore of the drill pipe and collars to contact pins projecting into the bore of the sub. Energizing the electromagnet causes the drill bit to be magnetized.

  4. Content based retrieval of lesioned brain images

    NASA Astrophysics Data System (ADS)

    Batty, Stephen; Blandford, Ann; Clark, John; Fryer, Tim; Gao, Xiaohong

    2002-05-01

    HI-PACS enable more efficient data-management leading to increased operating efficiency and therefore better patient care, a content based pet image retrieval system would contribute to the development of a HI-PACS. A database of PET neuro-images has been created with a facility for retrieving via visual content. The adaptation of algorithms developed for alternate imaging modalities (eg-MRI) formed the basis of feature detection and measurement algorithms. The application of these algorithms to greyscale PET images results in data that is employed as database indices and similarity metrics. The feature detection and measurement algorithms can be split into two different methods. The first uses the extracted ideal mid sagittal symmetry line to detect differences between the two hemisphere of the brain, while the second utilizes Gabor filters to measure the texture of the whole brain.

  5. Representation, indexing, and retrieval of moving objects

    NASA Astrophysics Data System (ADS)

    Ye, Huanzhuo; Gong, Jianya; Li, Deren; Pan, Jianping; Chen, Yumin

    2003-12-01

    Moving objects are complicated to manage because they involve temporal attributes as well as spatial attributes. There are two methods to represent the motion of moving objects, function method and sampling method. Motion state modeling, based on sampling method, can give object's position, orientation and their changes at a specific epoch, and encapsulates all the calculation by object orientation method. A big job is to search the motion state vectors efficiently, which can be performed with the help of 2n index trees. 2n index tree is an efficient index method to multi-dimensional data. Different kinds of motion data retrieval can be transformed to basic searching in 2n index trees. With proper operation algorithm, 2n index trees work well with the indexing and retrieval of moving objects.

  6. JURASSIC Retrieval Processing

    NASA Astrophysics Data System (ADS)

    Blank, J.; Ungermann, J.; Guggenmoser, T.; Kaufmann, M.; Riese, M.

    2012-04-01

    The Gimballed Limb Observer for Radiance Imaging in the Atmosphere (GLORIA) is an aircraft based infrared limb-sounder. This presentation will give an overview of the retrieval techniques used for the analysis of data produced by the GLORIA instrument. For data processing, the JUelich RApid Spectral SImulation Code 2 (JURASSIC2) was developed. It consists of a set of programs to retrieve atmospheric profiles from GLORIA measurements. The GLORIA Michelson interferometer can run with a wide range of parameters. In the dynamics mode, spectra are generate with a medium spectral and a very high temporal and spatial resolution. Each sample can contain thousands of spectral lines for each contributing trace gas. In the JURASSIC retrieval code this is handled by using a radiative transport model based on the Emissivity Growth Approximation. Deciding which samples should be included in the retrieval is a non-trivial task and requires specific domain knowledge. To ease this problem we developed an automatic selection program by analysing the Shannon information content. By taking into account data for all relevant trace gases and instrument effects, optimal integrated spectral windows are computed. This includes considerations for cross-influence of trace gases, which has non-obvious consequence for the contribution of spectral samples. We developed methods to assess the influence of spectral windows on the retrieval. While we can not exhaustively search the whole range of possible spectral sample combinations, it is possible to optimize information content using a genetic algorithm. The GLORIA instrument is mounted with a viewing direction perpendicular to the flight direction. A gimbal frame makes it possible to move the instrument 45° to both direction. By flying on a circular path, it is possible to generate images of an area of interest from a wide range of angles. These can be analyzed in a 3D-tomographic fashion, which yields superior spatial resolution along line of

  7. Physical Retrieval of Surface Emissivity Spectrum from Hyperspectral Infrared Radiances

    NASA Technical Reports Server (NTRS)

    Li, Jun; Weisz, Elisabeth; Zhou, Daniel K.

    2007-01-01

    Retrieval of temperature, moisture profiles and surface skin temperature from hyperspectral infrared (IR) radiances requires spectral information about the surface emissivity. Using constant or inaccurate surface emissivities typically results in large retrieval errors, particularly over semi-arid or arid areas where the variation in emissivity spectrum is large both spectrally and spatially. In this study, a physically based algorithm has been developed to retrieve a hyperspectral IR emissivity spectrum simultaneously with the temperature and moisture profiles, as well as the surface skin temperature. To make the solution stable and efficient, the hyperspectral emissivity spectrum is represented by eigenvectors, derived from the laboratory measured hyperspectral emissivity database, in the retrieval process. Experience with AIRS (Atmospheric InfraRed Sounder) radiances shows that a simultaneous retrieval of the emissivity spectrum and the sounding improves the surface skin temperature as well as temperature and moisture profiles, particularly in the near surface layer.

  8. Guenter Tulip Filter Retrieval Experience: Predictors of Successful Retrieval

    SciTech Connect

    Turba, Ulku Cenk Arslan, Bulent Meuse, Michael Sabri, Saher; Macik, Barbara Gail

    2010-08-15

    We report our experience with Guenter Tulip filter placement indications, retrievals, and procedural problems, with emphasis on alternative retrieval techniques. We have identified 92 consecutive patients in whom a Guenter Tulip filter was placed and filter removal attempted. We recorded patient demographic information, filter placement and retrieval indications, procedures, standard and nonstandard filter retrieval techniques, complications, and clinical outcomes. The mean time to retrieval for those who experienced filter strut penetration was statistically significant [F(1,90) = 8.55, p = 0.004]. Filter strut(s) IVC penetration and successful retrieval were found to be statistically significant (p = 0.043). The filter hook-IVC relationship correlated with successful retrieval. A modified guidewire loop technique was applied in 8 of 10 cases where the hook appeared to penetrate the IVC wall and could not be engaged with a loop snare catheter, providing additional technical success in 6 of 8 (75%). Therefore, the total filter retrieval success increased from 88 to 95%. In conclusion, the Guenter Tulip filter has high successful retrieval rates with low rates of complication. Additional maneuvers such as a guidewire loop method can be used to improve retrieval success rates when the filter hook is endothelialized.

  9. Improved bidirectional retrieval of sparse patterns stored by Hebbian learning.

    PubMed

    Sommer, Friedrich T.; Palm, Gunther

    1999-03-01

    The Willshaw model is asymptotically the most efficient neural associative memory (NAM), but its finite version is hampered by high retrieval errors. Iterative retrieval has been proposed in a large number of different models to improve performance in auto-association tasks. In this paper, bidirectional retrieval for the hetero-associative memory task is considered: we define information efficiency as a general performance measure for bidirectional associative memory (BAM) and determine its asymptotic bound for the bidirectional Willshaw model. For the finite Willshaw model, an efficient new bidirectional retrieval strategy is proposed, the appropriate combinatorial model analysis is derived, and implications of the proposed sparse BAM for applications and brain theory are discussed. The distribution of the dendritic sum in the finite Willshaw model given by Buckingham and Willshaw [Buckingham, J., & Willshaw, D. (1992). Performance characteristics of associative nets. Network, 3, 407-414] allows no fast numerical evaluation. We derive a combinatorial formula with a highly reduced evaluation time that is used in the improved error analysis of the basic model and for estimation of the retrieval error in the naive model extension, where bidirectional retrieval is employed in the hetero-associative Willshaw model. The analysis rules out the naive BAM extension as a promising improvement. A new bidirectional retrieval algorithm - called crosswise bidirectional (CB) retrieval - is presented. The cross talk error is significantly reduced without employing more complex learning procedures or dummy augmentation in the pattern coding, as proposed in other refined BAM models [Wang, Y. F., Cruz, J. B., & Mulligan, J. H. (1990). Two coding strategies for bidirectional associative memory. IEEE Trans. Neural Networks, 1(1), 81-92; Leung, C.-S., Chan, L.-W., & Lai, E. (1995). Stability, capacity and statistical dynamics of second-order bidirectional associative memory. IEEE Trans

  10. Medical Image Retrieval: A Multimodal Approach

    PubMed Central

    Cao, Yu; Steffey, Shawn; He, Jianbiao; Xiao, Degui; Tao, Cui; Chen, Ping; Müller, Henning

    2014-01-01

    Medical imaging is becoming a vital component of war on cancer. Tremendous amounts of medical image data are captured and recorded in a digital format during cancer care and cancer research. Facing such an unprecedented volume of image data with heterogeneous image modalities, it is necessary to develop effective and efficient content-based medical image retrieval systems for cancer clinical practice and research. While substantial progress has been made in different areas of content-based image retrieval (CBIR) research, direct applications of existing CBIR techniques to the medical images produced unsatisfactory results, because of the unique characteristics of medical images. In this paper, we develop a new multimodal medical image retrieval approach based on the recent advances in the statistical graphic model and deep learning. Specifically, we first investigate a new extended probabilistic Latent Semantic Analysis model to integrate the visual and textual information from medical images to bridge the semantic gap. We then develop a new deep Boltzmann machine-based multimodal learning model to learn the joint density model from multimodal information in order to derive the missing modality. Experimental results with large volume of real-world medical images have shown that our new approach is a promising solution for the next-generation medical imaging indexing and retrieval system. PMID:26309389

  11. Medical Image Retrieval: A Multimodal Approach.

    PubMed

    Cao, Yu; Steffey, Shawn; He, Jianbiao; Xiao, Degui; Tao, Cui; Chen, Ping; Müller, Henning

    2014-01-01

    Medical imaging is becoming a vital component of war on cancer. Tremendous amounts of medical image data are captured and recorded in a digital format during cancer care and cancer research. Facing such an unprecedented volume of image data with heterogeneous image modalities, it is necessary to develop effective and efficient content-based medical image retrieval systems for cancer clinical practice and research. While substantial progress has been made in different areas of content-based image retrieval (CBIR) research, direct applications of existing CBIR techniques to the medical images produced unsatisfactory results, because of the unique characteristics of medical images. In this paper, we develop a new multimodal medical image retrieval approach based on the recent advances in the statistical graphic model and deep learning. Specifically, we first investigate a new extended probabilistic Latent Semantic Analysis model to integrate the visual and textual information from medical images to bridge the semantic gap. We then develop a new deep Boltzmann machine-based multimodal learning model to learn the joint density model from multimodal information in order to derive the missing modality. Experimental results with large volume of real-world medical images have shown that our new approach is a promising solution for the next-generation medical imaging indexing and retrieval system.

  12. Human memory retrieval as Lévy foraging

    NASA Astrophysics Data System (ADS)

    Rhodes, Theo; Turvey, Michael T.

    2007-11-01

    When people attempt to recall as many words as possible from a specific category (e.g., animal names) their retrievals occur sporadically over an extended temporal period. Retrievals decline as recall progresses, but short retrieval bursts can occur even after tens of minutes of performing the task. To date, efforts to gain insight into the nature of retrieval from this fundamental phenomenon of semantic memory have focused primarily upon the exponential growth rate of cumulative recall. Here we focus upon the time intervals between retrievals. We expected and found that, for each participant in our experiment, these intervals conformed to a Lévy distribution suggesting that the Lévy flight dynamics that characterize foraging behavior may also characterize retrieval from semantic memory. The closer the exponent on the inverse square power-law distribution of retrieval intervals approximated the optimal foraging value of 2, the more efficient was the retrieval. At an abstract dynamical level, foraging for particular foods in one's niche and searching for particular words in one's memory must be similar processes if particular foods and particular words are randomly and sparsely located in their respective spaces at sites that are not known a priori. We discuss whether Lévy dynamics imply that memory processes, like foraging, are optimized in an ecological way.

  13. Compressive Shift Retrieval

    NASA Astrophysics Data System (ADS)

    Ohlsson, Henrik; Eldar, Yonina C.; Yang, Allen Y.; Sastry, S. Shankar

    2014-08-01

    The classical shift retrieval problem considers two signals in vector form that are related by a shift. The problem is of great importance in many applications and is typically solved by maximizing the cross-correlation between the two signals. Inspired by compressive sensing, in this paper, we seek to estimate the shift directly from compressed signals. We show that under certain conditions, the shift can be recovered using fewer samples and less computation compared to the classical setup. Of particular interest is shift estimation from Fourier coefficients. We show that under rather mild conditions only one Fourier coefficient suffices to recover the true shift.

  14. Music retrieval in ICOR

    NASA Astrophysics Data System (ADS)

    Finsterle, Lutz; Fischer, Stephan; Rimac, Ivica; Steinmetz, Ralf

    1999-08-01

    In this paper we describe music retrieval in ICOR, a project of Darmstadt TU. It is the goal of ICOR to find new interfaces to support applications of music video and music CDs. Although the project consists of audio and video analysis we concentrate on a description of the audio algorithms in this paper. We describe our MPEG-7 like data structure to store meta information for music pieces and explain which algorithms we use to analyze the content of music pieces automatically. We currently use an applause detection to distinguish live music from studio recordings, a genre classifier to distinguish pieces with beats form classical music, and a singer recognition.

  15. 2. VIEW OF INTERIOR OF XY RETRIEVER. THE XY RETRIEVER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW OF INTERIOR OF X-Y RETRIEVER. THE X-Y RETRIEVER WAS HOUSED IN MODULE K AND WAS USED TO SORT AND RETRIEVE PLUTONIUM METAL FROM A STORAGE VAULT FOR DISTRIBUTION TO OTHER PROCESSES IN BUILDING 707. (11/29/88) - Rocky Flats Plant, Plutonium Manufacturing Facility, North-central section of Plant, just south of Building 776/777, Golden, Jefferson County, CO

  16. Classification and retrieval on macroinvertebrate image databases.

    PubMed

    Kiranyaz, Serkan; Ince, Turker; Pulkkinen, Jenni; Gabbouj, Moncef; Ärje, Johanna; Kärkkäinen, Salme; Tirronen, Ville; Juhola, Martti; Turpeinen, Tuomas; Meissner, Kristian

    2011-07-01

    Aquatic ecosystems are continuously threatened by a growing number of human induced changes. Macroinvertebrate biomonitoring is particularly efficient in pinpointing the cause-effect structure between slow and subtle changes and their detrimental consequences in aquatic ecosystems. The greatest obstacle to implementing efficient biomonitoring is currently the cost-intensive human expert taxonomic identification of samples. While there is evidence that automated recognition techniques can match human taxa identification accuracy at greatly reduced costs, so far the development of automated identification techniques for aquatic organisms has been minimal. In this paper, we focus on advancing classification and data retrieval that are instrumental when processing large macroinvertebrate image datasets. To accomplish this for routine biomonitoring, in this paper we shall investigate the feasibility of automated river macroinvertebrate classification and retrieval with high precision. Besides the state-of-the-art classifiers such as Support Vector Machines (SVMs) and Bayesian Classifiers (BCs), the focus is particularly drawn on feed-forward artificial neural networks (ANNs), namely multilayer perceptrons (MLPs) and radial basis function networks (RBFNs). Since both ANN types have been proclaimed superior by different investigations even for the same benchmark problems, we shall first show that the main reason for this ambiguity lies in the static and rather poor comparison methodologies applied in most earlier works. Especially the most common drawback occurs due to the limited evaluation of the ANN performances over just one or few network architecture(s). Therefore, in this study, an extensive evaluation of each classifier performance over an ANN architecture space is performed. The best classifier among all, which is trained over a dataset of river macroinvertebrate specimens, is then used in the MUVIS framework for the efficient search and retrieval of particular

  17. Active index for content-based medical image retrieval.

    PubMed

    Chang, S K

    1996-01-01

    This paper introduces the active index for content-based medical image retrieval. The dynamic nature of the active index is its most important characteristic. With an active index, we can effectively and efficiently handle smart images that respond to accessing, probing and other actions. The main applications of the active index are to prefetch image and multimedia data, and to facilitate similarity retrieval. The experimental active index system is described. PMID:8954230

  18. Active index for content-based medical image retrieval.

    PubMed

    Chang, S K

    1996-01-01

    This paper introduces the active index for content-based medical image retrieval. The dynamic nature of the active index is its most important characteristic. With an active index, we can effectively and efficiently handle smart images that respond to accessing, probing and other actions. The main applications of the active index are to prefetch image and multimedia data, and to facilitate similarity retrieval. The experimental active index system is described.

  19. [Spectral curve shape feature-based hyperspectral remote sensing image retrieval].

    PubMed

    Li, Fei; Zhou, Cheng-Hu; Chen, Rong-Guo

    2008-11-01

    With the rapid development of technology of sensors and data transmission, using all kinds of airplane sensors and satellite sensors, the authors can get different voluminous remote sensing image data of earth. Those voluminous remote sensing image data bring problems of data storage and management. It is becoming increasingly necessary to retrieve some information the authors need from those voluminous image data. Image retrieval was proposed by CHANG firstly in 1980 and can be regarded as expansion of traditional information retrieval. Oriented to the demands of efficient retrieval for voluminous remote sensing image, and considering that there are many bands in hyperspectral remote sensing image, the authors first analyzed image distance function and similarity measure in image retrieval. The most crucial issues in retrieval are spectral features extraction and similarity measure. In the present paper, the authors used classical Douglas-Peucker algorithm (hereinafter referred to DP algorithm) for curve simplification to extract shape features of spectral curve, in order to speed up hyperspectral remote sensing image retrieval. And the authors proposed a new method of spectral curve and remote sensing image retrieval, called Douglas-Peucker Spectral Retrieval algorithm (hereinafter referred to DPSR algorithm). Spectral shape features were used in image retrieval. DPSR used features of spectral curve, reduced the computation amount, realized match and retrieval efficiently, and is suitable for spectral curve retrieval in hyperspectral remote sensing image. The authors selected four ground features (grass, apple garden, grape garden and pond) in OMISI hyperspectral remote sensing image to compute similarity measure results, in order to test the effect of DPSR algorithm. Compared with traditional analysis method such as spectral angle match (SAM) and spectral information divergence (SID), DPSR can maintain high precision of results with less amount of computation

  20. EM-21 Retrieval Knowledge Center: Waste Retrieval Challenges

    SciTech Connect

    Fellinger, Andrew P.; Rinker, Michael W.; Berglin, Eric J.; Minichan, Richard L.; Poirier, Micheal R.; Gauglitz, Phillip A.; Martin, Bruce A.; Hatchell, Brian K.; Saldivar, Eloy; Mullen, O Dennis; Chapman, Noel F.; Wells, Beric E.; Gibbons, Peter W.

    2009-04-10

    EM-21 is the Waste Processing Division of the Office of Engineering and Technology, within the U.S. Department of Energy’s (DOE) Office of Environmental Management (EM). In August of 2008, EM-21 began an initiative to develop a Retrieval Knowledge Center (RKC) to provide the DOE, high level waste retrieval operators, and technology developers with centralized and focused location to share knowledge and expertise that will be used to address retrieval challenges across the DOE complex. The RKC is also designed to facilitate information sharing across the DOE Waste Site Complex through workshops, and a searchable database of waste retrieval technology information. The database may be used to research effective technology approaches for specific retrieval tasks and to take advantage of the lessons learned from previous operations. It is also expected to be effective for remaining current with state-of-the-art of retrieval technologies and ongoing development within the DOE Complex. To encourage collaboration of DOE sites with waste retrieval issues, the RKC team is co-led by the Savannah River National Laboratory (SRNL) and the Pacific Northwest National Laboratory (PNNL). Two RKC workshops were held in the Fall of 2008. The purpose of these workshops was to define top level waste retrieval functional areas, exchange lessons learned, and develop a path forward to support a strategic business plan focused on technology needs for retrieval. The primary participants involved in these workshops included retrieval personnel and laboratory staff that are associated with Hanford and Savannah River Sites since the majority of remaining DOE waste tanks are located at these sites. This report summarizes and documents the results of the initial RKC workshops. Technology challenges identified from these workshops and presented here are expected to be a key component to defining future RKC-directed tasks designed to facilitate tank waste retrieval solutions.

  1. Semantic processing in information retrieval.

    PubMed Central

    Rindflesch, T. C.; Aronson, A. R.

    1993-01-01

    Intuition suggests that one way to enhance the information retrieval process would be the use of phrases to characterize the contents of text. A number of researchers, however, have noted that phrases alone do not improve retrieval effectiveness. In this paper we briefly review the use of phrases in information retrieval and then suggest extensions to this paradigm using semantic information. We claim that semantic processing, which can be viewed as expressing relations between the concepts represented by phrases, will in fact enhance retrieval effectiveness. The availability of the UMLS domain model, which we exploit extensively, significantly contributes to the feasibility of this processing. PMID:8130547

  2. Tank Waste Retrieval Lessons Learned at the Hanford Site

    SciTech Connect

    Dodd, R.A.

    2008-07-01

    {sup 3}. Tank S-112 retrieval was completed February 28, 2007, meeting the TPA Limits of less than 360 cu ft using salt-cake dissolution, modified sluicing, in-tank vehicle with high pressure water spray and caustic dissolution. Tanks C-108 and C-109 have been retrieved to 90% and 85% respectively. Modified sluicing was no longer effective at retrieving the remaining 5,000 to 10,000 gallons of residual. A Mobile Retrieval Tool (FoldTrac) is scheduled for installation early in 2008 to assist in breaking up chunks of waste and mobilizing the waste for transfer. Lessons learned from application of new tank waste retrieval methods are being documented and incorporated into future retrieval operations. They address all phases of retrieval including process design, equipment procurement and installation, supporting documentation, and system operations. Information is obtained through interviews with retrieval project personnel, focused workshops, review of problem evaluation requests, and evaluation of retrieval performance data. This paper presents current retrieval successes and lessons learned from retrieval of tank waste at the Hanford Site and discusses how this information is used to optimize retrieval system efficiency, improve overall cost effectiveness of retrieval operations, and ensure that HFFACO requirements are met. (authors)

  3. Topology of Document Retrieval Systems.

    ERIC Educational Resources Information Center

    Everett, Daniel M.; Cater, Steven C.

    1992-01-01

    Explains the use of a topological structure to examine the closeness between documents in retrieval systems and analyzes the topological structure of a vector-space model, a fuzzy-set model, an extended Boolean model, a probabilistic model, and a TIRS (Topological Information Retrieval System) model. Proofs for the results are appended. (17…

  4. Intelligent Information Retrieval: An Introduction.

    ERIC Educational Resources Information Center

    Gauch, Susan

    1992-01-01

    Discusses the application of artificial intelligence to online information retrieval systems and describes several systems: (1) CANSEARCH, from MEDLINE; (2) Intelligent Interface for Information Retrieval (I3R); (3) Gausch's Query Reformulation; (4) Environmental Pollution Expert (EP-X); (5) PLEXUS (gardening); and (6) SCISOR (corporate…

  5. Detecting Mood-Dependent Retrieval.

    ERIC Educational Resources Information Center

    Mayer, John D.; Bower, Gordon H.

    The mood-dependent retrieval hypothesis states that mood will enhance recall by acting as a recall cue if the stimuli have been learned initially in the same mood. Material learned in a happy mood will be best recalled when the person returns to a happy mood; the same holds for a sad mood. Mood-dependent retrieval effect has been regulary…

  6. Indexing Theory and Retrieval Effectiveness.

    ERIC Educational Resources Information Center

    Robertson, Stephen E.

    1978-01-01

    Describes recent attempts to make explicit connections between the indexing process and the use of the index or information retrieval system, particularly the utility-theoretic and automatic indexing models of William Cooper and Stephen Harter. Theory and performance, information storage and retrieval, search stage feedback, and indexing are also…

  7. Document Retrieval: A Structural Approach.

    ERIC Educational Resources Information Center

    Lu, Xin

    1990-01-01

    Describes the development of a structural model of document retrieval based on lexical-semantic relationships between index terms. An algorithm that uses tree-to-tree distance to measure structural closeness between a document and a query statement is explained, and the proposed model is compared to a vector retrieval model. (18 references) (LRW)

  8. Passage Retrieval: A Probabilistic Technique.

    ERIC Educational Resources Information Center

    Melucci, Massimo

    1998-01-01

    Presents a probabilistic technique to retrieve passages from texts having a large size or heterogeneous semantic content. Results of experiments comparing the probabilistic technique to one based on a text segmentation algorithm revealed that the passage size affects passage retrieval performance; text organization and query generality may have an…

  9. Application of Rough Sets to Information Retrieval.

    ERIC Educational Resources Information Center

    Miyamoto, Sadaaki

    1998-01-01

    Develops a method of rough retrieval, an application of the rough set theory to information retrieval. The aim is to: (1) show that rough sets are naturally applied to information retrieval in which categorized information structure is used; and (2) show that a fuzzy retrieval scheme is induced from the rough retrieval. (AEF)

  10. FPGA implementation of sparse matrix algorithm for information retrieval

    NASA Astrophysics Data System (ADS)

    Bojanic, Slobodan; Jevtic, Ruzica; Nieto-Taladriz, Octavio

    2005-06-01

    Information text data retrieval requires a tremendous amount of processing time because of the size of the data and the complexity of information retrieval algorithms. In this paper the solution to this problem is proposed via hardware supported information retrieval algorithms. Reconfigurable computing may adopt frequent hardware modifications through its tailorable hardware and exploits parallelism for a given application through reconfigurable and flexible hardware units. The degree of the parallelism can be tuned for data. In this work we implemented standard BLAS (basic linear algebra subprogram) sparse matrix algorithm named Compressed Sparse Row (CSR) that is showed to be more efficient in terms of storage space requirement and query-processing timing over the other sparse matrix algorithms for information retrieval application. Although inverted index algorithm is treated as the de facto standard for information retrieval for years, an alternative approach to store the index of text collection in a sparse matrix structure gains more attention. This approach performs query processing using sparse matrix-vector multiplication and due to parallelization achieves a substantial efficiency over the sequential inverted index. The parallel implementations of information retrieval kernel are presented in this work targeting the Virtex II Field Programmable Gate Arrays (FPGAs) board from Xilinx. A recent development in scientific applications is the use of FPGA to achieve high performance results. Computational results are compared to implementations on other platforms. The design achieves a high level of parallelism for the overall function while retaining highly optimised hardware within processing unit.

  11. National Water Data Exchange (NAWDEX) System 2000 data retrieval manual

    USGS Publications Warehouse

    Williams, Owen O.; Knecht, William A.

    1981-01-01

    The manual offers general instructions on the use of SYSTEM 2000 to retrieve any type of data, and specific instructions on how to retrieve data from the U.S. Geological Survey 's Water Data Sources Directory and Master Water Data Index Data Bases. The manual is divided into five major sections plus six appendixes for reference. Section I contains introductory material, including the purpose and scope of the manual, instructions on how to use the manual, basic computer concepts, and basic SYSTEM 2000 concepts. Section II contains basic instructions on retrieving and displaying data, and section III goes into more complex retrievals. Section IV explains how to make efficient use of techniques developed in sections II and III. Section V summarizes and discusses practical applications, and section IV contains all the appendixes required for reference. (USGS)

  12. Adaptive multi-agent system for information retrieval

    NASA Astrophysics Data System (ADS)

    Maleki-dizaji, Saeedeh; Nyongesa, H. O.; Siddiqqi, J.

    2001-10-01

    The current exponential growth of the Internet precipitates a need for improved tools to help people cope with the volume of information available. Existing search engines such, as Yahoo, Alta vista and Excite are efficient in terms of high recall (percentage of relevant document that are retrieved from Internet), and fast response time, at the cost of poor precision (percentage of documents retrieved that are considered relevant). The problem is due to the lack of filtering, lack of specialisation, lack of relevance feedback, lack of adaptation and lack of exploration. One solution for the above problems is to use intelligent agents, which can operate autonomously and become better over time. The agents rely on a user model to improve their performance in retrieving the information. This paper presents an adaptive information retrieval (IR) that learns from the user feedback through an evolutionary method, namely, genetic algorithms (GA).

  13. The remote sensing image retrieval based on multi-feature

    NASA Astrophysics Data System (ADS)

    Duan, Jian-bo; Ma, Cai-hong; Liu, Shi-bin; Zhang, Jing

    2013-10-01

    With the rapid development of remote sensing technology and variety of earth observation satellites have been successfully launched, the volume of image datasets is growing exponentially in many application areas. The Contentbased image retrieval (CBRSIR), as an efficient means for management and utilization of the information in image database from the viewpoint of comprehension of image content, is applied on the remote sensing images retrieval. However, one kind of features always can't express the image content exactly. So, a multi-feature retrieval model based on three color features and four texture features is proposed in this paper. The experiment results show that the multifeatures model can improve the retrieval results than other model just by each singular feature.

  14. Content-aware network storage system supporting metadata retrieval

    NASA Astrophysics Data System (ADS)

    Liu, Ke; Qin, Leihua; Zhou, Jingli; Nie, Xuejun

    2008-12-01

    Nowadays, content-based network storage has become the hot research spot of academy and corporation[1]. In order to solve the problem of hit rate decline causing by migration and achieve the content-based query, we exploit a new content-aware storage system which supports metadata retrieval to improve the query performance. Firstly, we extend the SCSI command descriptor block to enable system understand those self-defined query requests. Secondly, the extracted metadata is encoded by extensible markup language to improve the universality. Thirdly, according to the demand of information lifecycle management (ILM), we store those data in different storage level and use corresponding query strategy to retrieval them. Fourthly, as the file content identifier plays an important role in locating data and calculating block correlation, we use it to fetch files and sort query results through friendly user interface. Finally, the experiments indicate that the retrieval strategy and sort algorithm have enhanced the retrieval efficiency and precision.

  15. Pareto-depth for multiple-query image retrieval.

    PubMed

    Hsiao, Ko-Jen; Calder, Jeff; Hero, Alfred O

    2015-02-01

    Most content-based image retrieval systems consider either one single query, or multiple queries that include the same object or represent the same semantic information. In this paper, we consider the content-based image retrieval problem for multiple query images corresponding to different image semantics. We propose a novel multiple-query information retrieval algorithm that combines the Pareto front method with efficient manifold ranking. We show that our proposed algorithm outperforms state of the art multiple-query retrieval algorithms on real-world image databases. We attribute this performance improvement to concavity properties of the Pareto fronts, and prove a theoretical result that characterizes the asymptotic concavity of the fronts.

  16. 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)

  17. Launchable and Retrievable Tetherobot

    NASA Technical Reports Server (NTRS)

    Younse, Paulo; Aghazarian, Hrand

    2010-01-01

    A proposed robotic system for scientific exploration of rough terrain would include a stationary or infrequently moving larger base robot, to which would be tethered a smaller hopping robot of the type described in the immediately preceding article. The two-robot design would extend the reach of the base robot, making it possible to explore nearby locations that might otherwise be inaccessible or too hazardous for the base robot. The system would include a launching mechanism and a motor-driven reel on the larger robot. The outer end of the tether would be attached to the smaller robot; the inner end of the tether would be attached to the reel. The figure depicts the launching and retrieval process. The launching mechanism would aim and throw the smaller robot toward a target location, and the tether would be paid out from the reel as the hopping robot flew toward the target. Upon completion of exploratory activity at the target location, the smaller robot would be made to hop and, in a coordinated motion, the tether would be wound onto the reel to pull the smaller robot back to the larger one.

  18. Solid rocket booster retrieval operations

    NASA Technical Reports Server (NTRS)

    Rasmussen, A. M.

    1985-01-01

    Solid Rocket Booster Retrieval operations are discussed in detail. The recovery of expended boosters and associated hardware without damage attributable to retrieval procedures is the main goal. The retrieval force consists tof ship's personnel and retrieval team members, each of whom has been trained and is highly skilled in multi-faceted operations. The retrieval force is equipped with two specially-built, highly maneuverable ships outfitted with parachute reels, retrieval cranes, towing winches, large volume-low pressure air compressors, SCUBA diving gear, inflatable boats with outboard motors and diver-operated SRB dewatering devices. The two ships are deployed in sufficient time to conduct an electronic and visual search of the impact area prior to launch. Upon search completeion, each ship takes station a safe distance from the predetermined impact point initiating both visual and electronic search in the direction of flight path, ensuring SRB acquisition at splashdown. When safe, the ships enter the impact area and commence recovery of all floating flight hardware which is subsequently returned to the Disassembly Facility for refurbishment and reuse. Retrieval techniques have evolved in parallel with equipment and flight hardware configuration changes. Additional changes have been initiated to improve personnel safety.

  19. Polar Embedding for Aurora Image Retrieval.

    PubMed

    Yang, Xi; Gao, Xinbo; Tian, Qi

    2015-11-01

    Exploring the multimedia techniques to assist scientists for their research is an interesting and meaningful topic. In this paper, we focus on the large-scale aurora image retrieval by leveraging the bag-of-visual words (BoVW) framework. To refine the unsuitable representation and improve the retrieval performance, the BoVW model is modified by embedding the polar information. The superiority of the proposed polar embedding method lies in two aspects. On the one hand, the polar meshing scheme is conducted to determine the interest points, which is more suitable for images captured by circular fisheye lens. Especially for the aurora image, the extracted polar scale-invariant feature transform (polar-SIFT) feature can also reflect the geomagnetic longitude and latitude, and thus facilitates the further data analysis. On the other hand, a binary polar deep local binary pattern (polar-DLBP) descriptor is proposed to enhance the discriminative power of visual words. Together with the 64-bit polar-SIFT code obtained via Hamming embedding, the multifeature index is performed to reduce the impact of false positive matches. Extensive experiments are conducted on the large-scale aurora image data set. The experimental result indicates that the proposed method improves the retrieval accuracy significantly with acceptable efficiency and memory cost. In addition, the effectiveness of the polar-SIFT scheme and polar-DLBP integration are separately demonstrated. PMID:26068312

  20. Using radiance of cloud shadow for retrieve Investigation of AOD retrieval with Himawari-8 satellite data

    NASA Astrophysics Data System (ADS)

    Sun, Ta-Min; Chang, Yuan-Hsiang; Chang, Kuo-En; Lin, Tang-Huang

    2016-04-01

    As we know, the emission of pollutants, such as dust storm, biomass burning and anthropogenic pollution are serious issues related to the environmental change and human health topics in Asia. With the high temporal observation over a broad area, the new generated geostationary satellite, Himawari-8 (H-8) seems to be a good choice for atmospheric pollution monitor. It can provide the observation over Asia with 16 bands in visible and thermal infrared spectral every 10 minutes. For the atmospheric pollutant monitor by means of remote sensing, the retrieval of aerosol optical depth (AOD) is the most important index. In this study, the long method is employed for AOD retrieval which depends on the path radiance significantly. Apparent radiance of the suitable cloud shadow is selected as the path radiance. In order to let the atmospheric pollution monitor is used efficiently, so the distribution of the path radiance is using the objective analysis to expand it. The results of AOD retrieval from H-8 visible data are well consistent with MODIS (Moderate Resolution Imaging Spectroradiometer) AOD products and ground measurements AERONET (Aerosol Robotic Networks), indicating the practical of proposed approach for the AOD retrieval with H-8 data.

  1. Network and User-Perceived Performance of Web Page Retrievals

    NASA Technical Reports Server (NTRS)

    Kruse, Hans; Allman, Mark; Mallasch, Paul

    1998-01-01

    The development of the HTTP protocol has been driven by the need to improve the network performance of the protocol by allowing the efficient retrieval of multiple parts of a web page without the need for multiple simultaneous TCP connections between a client and a server. We suggest that the retrieval of multiple page elements sequentially over a single TCP connection may result in a degradation of the perceived performance experienced by the user. We attempt to quantify this perceived degradation through the use of a model which combines a web retrieval simulation and an analytical model of TCP operation. Starting with the current HTTP/l.1 specification, we first suggest a client@side heuristic to improve the perceived transfer performance. We show that the perceived speed of the page retrieval can be increased without sacrificing data transfer efficiency. We then propose a new client/server extension to the HTTP/l.1 protocol to allow for the interleaving of page element retrievals. We finally address the issue of the display of advertisements on web pages, and in particular suggest a number of mechanisms which can make efficient use of IP multicast to send advertisements to a number of clients within the same network.

  2. System For Retrieving Reusable Software

    NASA Technical Reports Server (NTRS)

    Van Warren, Lloyd; Beckman, Brian C.

    1993-01-01

    Encyclopedia of Software Components (ESC) is information-retrieval system of computer hardware and software providing access to generic reusable software tools and parts. Core of ESC is central tool base, which is repository of reusable software. It receives queries and submissions from user through local browser subsystem and receives authorized updates from maintenance subsystem. Sends retrievals to local browser subsystem and user's submissions to maintenance subsystem. Future versions will provide for advanced media, including voice and video, and will link system to database-management system. Programmers will not only retrieve software, but also modify, execute, and cross-link with other software.

  3. Mobile medical visual information retrieval.

    PubMed

    Depeursinge, Adrien; Duc, Samuel; Eggel, Ivan; Müller, Henning

    2012-01-01

    In this paper, we propose mobile access to peer-reviewed medical information based on textual search and content-based visual image retrieval. Web-based interfaces designed for limited screen space were developed to query via web services a medical information retrieval engine optimizing the amount of data to be transferred in wireless form. Visual and textual retrieval engines with state-of-the-art performance were integrated. Results obtained show a good usability of the software. Future use in clinical environments has the potential of increasing quality of patient care through bedside access to the medical literature in context.

  4. Highly efficient terahertz wave modulators by photo-excitation of organics/silicon bilayers

    SciTech Connect

    Yoo, Hyung Keun; Kang, Chul; Hwang, In-Wook; Yoon, Youngwoon; Lee, Kiejin; Kee, Chul-Sik; Lee, Joong Wook

    2014-07-07

    Using hybrid bilayer systems comprising a molecular organic semiconductor and silicon, we achieve optically controllable active terahertz (THz) modulators that exhibit extremely high modulation efficiencies. A modulation efficiency of 98% is achieved from thermally annealed C{sub 60}/silicon bilayers, due to the rapid photo-induced electron transfer from the excited states of the silicon onto the C{sub 60} layer. Furthermore, we demonstrate the broadband modulation of THz waves. The cut-off condition of the system that is determined by the formation of efficient charge separation by the photo-excitation is highly variable, changing the system from insulating to metallic. The phenomenon enables an extremely high modulation bandwidth and rates of electromagnetic waves of interest. The realization of near-perfect modulation efficiency in THz frequencies opens up the possibilities of utilizing active modulators for THz spectroscopy and communications.

  5. High-efficiency spectral purity filter for EUV lithography

    DOEpatents

    Chapman, Henry N.

    2006-05-23

    An asymmetric-cut multilayer diffracts EUV light. A multilayer cut at an angle has the same properties as a blazed grating, and has been demonstrated to have near-perfect performance. Instead of having to nano-fabricate a grating structure with imperfections no greater than several tens of nanometers, a thick multilayer is grown on a substrate and then cut at an inclined angle using coarse and inexpensive methods. Effective grating periods can be produced this way that are 10 to 100 times smaller than those produced today, and the diffraction efficiency of these asymmetric multilayers is higher than conventional gratings. Besides their ease of manufacture, the use of an asymmetric multilayer as a spectral purity filter does not require that the design of an EUV optical system be modified in any way, unlike the proposed use of blazed gratings for such systems.

  6. Phase retrieval using nonlinear diversity.

    PubMed

    Lu, Chien-Hung; Barsi, Christopher; Williams, Matthew O; Kutz, J Nathan; Fleischer, Jason W

    2013-04-01

    We extend the Gerchberg-Saxton algorithm to phase retrieval in a nonlinear system. Using a tunable photorefractive crystal, we experimentally demonstrate the noninterferometric technique by reconstructing an unknown phase object from optical intensity measurements taken at different nonlinear strengths.

  7. Cranfield Conference on Information Retrieval.

    ERIC Educational Resources Information Center

    Kuo, Franklin F.

    The Third Cranfield Conference on Mechanised Information Storage and Retrieval Systems was held on 20-23 July 1971 in Cranfield, England. The report describes a number of the key papers presented at this conference. (Author)

  8. Catalogue Retrieval: A Library Economy

    ERIC Educational Resources Information Center

    Ready, William

    1970-01-01

    An evaluation of the Information Dynamics Corporation Retrieval System in an academic library, describing the specification of the machine and the various reader printers tested at Mills Memorial Library, McMaster University. (Author)

  9. Measuring the Storage and Retrieval of Knowledge Units: An Empirical Study Using MES

    NASA Astrophysics Data System (ADS)

    Justus, Selwyn; Iyakutti, K.

    Computer applications are smart that they require efficient storage and retrieval of data. Object-relational data models are the opted and the widely appreciable approach because of their power in object representation and relational retrieval. Two OR models were designed for representing knowledge units in the Music Expert System and three metrics were proposed to study the storage and retrieval of the knowledge units from the OR schemas. Experiments conducted to asses the storage efficiency and relational retrieval of the objects indicated significant results. The metrics were used to keep in check the size of the objects created during runtime and their relational coupling helped in the retrieval of objects, with minimal disk reads. The empirical results and interpretations concludes the work, focusing on the efficient design of OR schema models which commend the functioning of the system’s performance.

  10. Content-based image retrieval on mobile devices

    NASA Astrophysics Data System (ADS)

    Ahmad, Iftikhar; Abdullah, Shafaq; Kiranyaz, Serkan; Gabbouj, Moncef

    2005-03-01

    Content-based image retrieval area possesses a tremendous potential for exploration and utilization equally for researchers and people in industry due to its promising results. Expeditious retrieval of desired images requires indexing of the content in large-scale databases along with extraction of low-level features based on the content of these images. With the recent advances in wireless communication technology and availability of multimedia capable phones it has become vital to enable query operation in image databases and retrieve results based on the image content. In this paper we present a content-based image retrieval system for mobile platforms, providing the capability of content-based query to any mobile device that supports Java platform. The system consists of light-weight client application running on a Java enabled device and a server containing a servlet running inside a Java enabled web server. The server responds to image query using efficient native code from selected image database. The client application, running on a mobile phone, is able to initiate a query request, which is handled by a servlet in the server for finding closest match to the queried image. The retrieved results are transmitted over mobile network and images are displayed on the mobile phone. We conclude that such system serves as a basis of content-based information retrieval on wireless devices and needs to cope up with factors such as constraints on hand-held devices and reduced network bandwidth available in mobile environments.

  11. Systematically Retrieving Research: A Case Study Evaluating Seven Databases

    ERIC Educational Resources Information Center

    Taylor, Brian; Wylie, Emma; Dempster, Martin; Donnelly, Michael

    2007-01-01

    Objective: Developing the scientific underpinnings of social welfare requires effective and efficient methods of retrieving relevant items from the increasing volume of research. Method: We compared seven databases by running the nearest equivalent search on each. The search topic was chosen for relevance to social work practice with older people.…

  12. Data retrieval system provides unlimited hardware design information

    NASA Technical Reports Server (NTRS)

    Rawson, R. D.; Swanson, R. L.

    1967-01-01

    Data is input to magnetic tape on a single format card that specifies the system, location, and component, the test point identification number, the operators initial, the date, a data code, and the data itself. This method is efficient for large volume data storage and retrieval, and permits output variations without continuous program modifications.

  13. Retrieval of ERIC Files. An On-Line Approach.

    ERIC Educational Resources Information Center

    McIsaac, Donald N.; Olson, Thomas

    A description is provided for WISE-ONE, an information retrieval program designed to provide fast, efficient access to computer-based information files. The author focuses upon WISE-ONE's application to the Educational Resources Information Center's (ERIC) data base; WISE-ONE was designed specifically to meet the needs of researchers using ERIC,…

  14. Test-Retest Stability of Word Retrieval in Aphasic Discourse

    ERIC Educational Resources Information Center

    Boyle, Mary

    2014-01-01

    Purpose: This study examined the test-retest stability of select word-retrieval measures in the discourses of people with aphasia who completed a 5-stimulus discourse task. Method: Discourse samples across 3 sessions from 12 individuals with aphasia were analyzed for the stability of measures of informativeness, efficiency, main concepts, noun and…

  15. Retrieval experience in prospective memory: strategic monitoring and spontaneous retrieval.

    PubMed

    Meier, Beat; Zimmermann, Thomas D; Perrig, Walter J

    2006-10-01

    According to the multi-process model of prospective memory (McDaniel & Einstein, 2000), performance in a prospective memory task may be due to spontaneous retrieval processes or due to strategic monitoring. Spontaneous retrieval is typically accompanied by a pop up experience and strategic monitoring by a search experience. In this study we report two experiments with young adults in which we systematically investigated whether retrieval experience differed across experimental conditions. In Experiment 1 some prospective memory targets were preceded by associated primes. We expected that presenting primes would enhance performance by an automatic activation of the intention and hence lead to an increase in pop up experiences. In Experiment 2 half of the participants received instructions containing information about the specific context in which the prospective memory task would occur, whereas the other half of the participants received no such information. We expected that specific context instructions would enhance performance by legitimate anticipation of the prospective memory task and hence would lead to an increase in search experiences. The results confirmed these expectations. They indicate that the assessment of retrieval experience can provide valuable insights into the processes underlying prospective memory performance. They also suggest that retrieval experience can vary systematically across experimental situations as predicted by the multi-process model.

  16. Inefficiency and Bias of Search Engines in Retrieving References Containing Scientific Names of Fossil Amphibians

    ERIC Educational Resources Information Center

    Brown, Lauren E.; Dubois, Alain; Shepard, Donald B.

    2008-01-01

    Retrieval efficiencies of paper-based references in journals and other serials containing 10 scientific names of fossil amphibians were determined for seven major search engines. Retrievals were compared to the number of references obtained covering the period 1895-2006 by a Comprehensive Search. The latter was primarily a traditional…

  17. Elaborative Retrieval: Do Semantic Mediators Improve Memory?

    ERIC Educational Resources Information Center

    Lehman, Melissa; Karpicke, Jeffrey D.

    2016-01-01

    The elaborative retrieval account of retrieval-based learning proposes that retrieval enhances retention because the retrieval process produces the generation of semantic mediators that link cues to target information. We tested 2 assumptions that form the basis of this account: that semantic mediators are more likely to be generated during…

  18. Robust segmentation and retrieval of environmental sounds

    NASA Astrophysics Data System (ADS)

    Wichern, Gordon

    The proliferation of mobile computing has provided much of the world with the ability to record any sound of interest, or possibly every sound heard in a lifetime. The technology to continuously record the auditory world has applications in surveillance, biological monitoring of non-human animal sounds, and urban planning. Unfortunately, the ability to record anything has led to an audio data deluge, where there are more recordings than time to listen. Thus, access to these archives depends on efficient techniques for segmentation (determining where sound events begin and end), indexing (storing sufficient information with each event to distinguish it from other events), and retrieval (searching for and finding desired events). While many such techniques have been developed for speech and music sounds, the environmental and natural sounds that compose the majority of our aural world are often overlooked. The process of analyzing audio signals typically begins with the process of acoustic feature extraction where a frame of raw audio (e.g., 50 milliseconds) is converted into a feature vector summarizing the audio content. In this dissertation, a dynamic Bayesian network (DBN) is used to monitor changes in acoustic features in order to determine the segmentation of continuously recorded audio signals. Experiments demonstrate effective segmentation performance on test sets of environmental sounds recorded in both indoor and outdoor environments. Once segmented, every sound event is indexed with a probabilistic model, summarizing the evolution of acoustic features over the course of the event. Indexed sound events are then retrieved from the database using different query modalities. Two important query types are sound queries (query-by-example) and semantic queries (query-by-text). By treating each sound event and semantic concept in the database as a node in an undirected graph, a hybrid (content/semantic) network structure is developed. This hybrid network can

  19. Free-space to single-mode collection efficiency enhancement using photonic lanterns.

    PubMed

    Ozdur, Ibrahim; Toliver, Paul; Agarwal, Anjali; Woodward, T K

    2013-09-15

    We demonstrate single-mode collection efficiency enhancement for free space optical systems using a photonic lantern to collect scattered infrared light from diffuse objects at far- and near-field distances. A single-mode collection efficiency improvement of ∼8  dB is demonstrated in the near-field region relative to standard single-mode fiber. The insertion loss properties of the photonic lantern are also analyzed, and an additional insertion loss penalty is observed for near-field distances when the transmitted beam is collimated. The photonic lantern can be used for coherent detection systems such as light detection and ranging and free-space optical communication with improved collection efficiency and nearly perfect mode matching.

  20. Retrieval of GOMOS bright limb ozone profiles

    NASA Astrophysics Data System (ADS)

    Tukiainen, Simo; Verronen, Pekka T.; Kyrola, Erkki; Tamminen, Johanna

    GOMOS is a stellar occultation instrument on board the ENVISAT satellite. During day time occultations limb scattered sunlight spectra are also recorded. These can be used to retrieve vertical profiles of ozone between 15-70 km. The retrieval method is the modified onion peeling inversion method that we have used earlier for retrievals from the OSIRIS instrument. In the retrieval we use an accurate single scattering modeling and look up tables for the multiple scattering modeling. The look up tables are produced using the Monte Carlo radiative transfer model Siro. We present here examples of the retrievals and compare our results with GOMOS occultation retrievals and OSIRIS retrievals.

  1. Predicting quantitative traits from genome and phenome with near perfect accuracy

    PubMed Central

    Märtens, Kaspar; Hallin, Johan; Warringer, Jonas; Liti, Gianni; Parts, Leopold

    2016-01-01

    In spite of decades of linkage and association studies and its potential impact on human health, reliable prediction of an individual's risk for heritable disease remains difficult. Large numbers of mapped loci do not explain substantial fractions of heritable variation, leaving an open question of whether accurate complex trait predictions can be achieved in practice. Here, we use a genome sequenced population of ∼7,000 yeast strains of high but varying relatedness, and predict growth traits from family information, effects of segregating genetic variants and growth in other environments with an average coefficient of determination R2 of 0.91. This accuracy exceeds narrow-sense heritability, approaches limits imposed by measurement repeatability and is higher than achieved with a single assay in the laboratory. Our results prove that very accurate prediction of complex traits is possible, and suggest that additional data from families rather than reference cohorts may be more useful for this purpose. PMID:27160605

  2. Vanadyl Phthalocyanine (C32H16N8VO): a near-perfect molecular paramagnet

    NASA Astrophysics Data System (ADS)

    Wang, Z.; Seehra, M. S.

    Transition-metal-doped phthalocyanines (TMPc, TM = Mn, Fe, Co, Ni, and Cu) are semiconductors with interesting photoconductive properties and so have potential applications in optoelectronic devices. TMPc are planar molecules with the TM atom at the center bound to four N atoms and forming a linear chain along the monoclinic b-axis. Recent magnetic studies reported in CuPc, CoPc, and MnPc show that the exchange coupling between the TM ions are either ferromagnetic as in MnPc or antiferromagnetic as in CuPc and CoPc. In contrast to TMPc, VOPc has a five- coordinate square pyramidal structure with a single electron associated with VO2+ ion. Here we report results from detailed investigations of the magnetic properties of powder sample of VOPc X-ray diffraction of which shows it to be triclinic. Temperature dependence of magnetization M from 2 K to 300 K in H = 1 kOe fits the Curie-Weiss (CW) law with θ = 0 K, μ = 1.665μB and g = 1.922 for spin S = 1/2 which indicates VOPc is paramagnetic without any exchange coupling between VO2+ ions, quite different from CuPc, CoPc and MnPc. Also, M vs. H data (up to 90 kOe) at 2 K, 5 K, 10 K, 25 K, 50 K, 100 K, and 300 K fit well with the Brillouin function variation for S = 1/2, again confirming perfect paramagnetism in VOPc.

  3. Nearly Perfect Absorbers Operating Associated with Fano Resonance in the Infrared Range

    NASA Astrophysics Data System (ADS)

    Huang, Wan-Xia; Zhao, Guo-Ren; Guo, Juan-Juan; Wang, Mao-Sheng; Shi, Jian-Ping

    2016-08-01

    Not Available Supported by the National Natural Science Foundation of China under Grant No 11304002, the Natural Science Foundation of Education Bureau of Anhui Province under Grant No KJ2013A136, and the Natural Science Foundation of Anhui Province under Grant No 1208085MA07.

  4. Document image retrieval with morphology-based segmentation and features combination

    NASA Astrophysics Data System (ADS)

    Bockholt, Tiago C.; Cavalcanti, George D. C.; Mello, Carlos A. B.

    2011-01-01

    Digital libraries need more than just a retrieval based on keywords, which can be inefficient for some applications. Thus, a document retrieval based on content of the digitized image version of the document can be a more appropriated approach. This paper discusses the retrieval of document images by means of identifying a variety of elements present in the document's image body. We propose a new strategy to identify and combine features extracted from a document image. We also consider the task of constructing an optimized feature set to improve the retrieval performance and to validate our experiments on an assorted database. Experimental results show that the proposed segmentation together with a wisely feature combination increase the overall retrieval performance. Moreover the retrieved images demonstrate the generality and effectiveness of our approach for an efficient segmentation and classification of document images.

  5. Content-based ultrasound image retrieval using a coarse to fine approach.

    PubMed

    Kwak, Dong-Min; Kim, Bum-Soo; Yoon, Ock-Kyung; Park, Chul-Hyung; Won, Jong-Un; Park, Kil-Houm

    2002-12-01

    One of the current issues for picture archiving and communication systems (PACS) is extending retrieval technologies to deal with multimedia information. This is particularly important for medical applications that assist in diagnostic processes and pathology studies. Accordingly, this paper presents a new approach to content-based image retrieval (CBIR) for a clinical ultrasound image database (DB). The proposed algorithm consists of two stages so as to maximize the retrieval efficiency. In the first stage, a coarse retrieval is performed using the statistical characteristics of the wavelet coefficients that narrow the search by eliminating up to 70% of the total DB images. In the second stage, a fine retrieval is carried out using the Legendre moment of the global histogram pdf on the reduced image set preretrieved by the coarse retrieval. When tested on an abdominal ultrasound image DB and compared with various other methods, the proposed algorithm gave promising results for applying CBIR to clinical ultrasound images. PMID:12594091

  6. Publication search and retrieval system

    USGS Publications Warehouse

    Winget, Elizabeth A.

    1981-01-01

    The publication search and retrieval system of the Branch of Atlantic-Gulf of Mexico Geology, U.S. Geological Survey, Woods Hole, Mass., is a procedure for listing and describing branch-sponsored publications. It is designed for maintenance and retrieval by those having limited knowledge of computer languages and programs. Because this branch currently utilizes the Hewlett-Packard HP-1000 computer with RTE-IVB operating system, database entry and maintenance is performed in accordance with the TE-IVB Terminal User’s Reference Manual (Hewlett-Packard Company, 1980) and within the constraints of GRASP (Bowen and Botbol, 1975) and WOLF (Evenden, 1978).

  7. Information retrieval for patient care.

    PubMed Central

    Gardner, M.

    1997-01-01

    Doctors need clinical information during most consultations with patients, and much of this need could be satisfied by material from online sources. Advances in data communication technologies mean that multimedia information can be transported rapidly to various clinical care locations. However, selecting the few items of information likely to be useful in a particular clinical situation from the mass of information available is a major problem. Current information retrieval systems are designed primarily for use in research rather than clinical care. The design, implementation, and critical evaluation of new information retrieval systems for clinical care should be guided by knowledgeable clinical users. PMID:9099122

  8. Content-based image retrieval by feature point matching

    NASA Astrophysics Data System (ADS)

    Hsu, Chiou-Ting; Wu, Ya-Ting; Chen, Arbee L. P.

    2001-01-01

    With the advance of multimedia technologies and the explosive expansion of the World Wide Web, the volume of image and video data increases rapidly. An efficient and effective multimedia data retrieval technique is needed. In this paper, we propose an approach based on feature points for the content-based image retrieval. The feature points extracted from the multiresolution representation of the query image and database image are first matched to determine the matching pairs. Then, the marching pairs are classified into groups. Finally, two similarity measurements based on different similarity requirements are proposed to compute the similarity degree. We perform a series of experiments to study the characteristics of this approach, and compare with the region-based approach on similar-shot sequence retrieval. The comparison shows the superiority of this approach.

  9. Content-based image retrieval by feature point matching

    NASA Astrophysics Data System (ADS)

    Hsu, Chiou-Ting; Wu, Ya-Ting; Chen, Arbee L.

    2000-12-01

    With the advance of multimedia technologies and the explosive expansion of the World Wide Web, the volume of image and video data increases rapidly. An efficient and effective multimedia data retrieval technique is needed. In this paper, we propose an approach based on feature points for the content-based image retrieval. The feature points extracted from the multiresolution representation of the query image and database image are first matched to determine the matching pairs. Then, the marching pairs are classified into groups. Finally, two similarity measurements based on different similarity requirements are proposed to compute the similarity degree. We perform a series of experiments to study the characteristics of this approach, and compare with the region-based approach on similar-shot sequence retrieval. The comparison shows the superiority of this approach.

  10. Spectral Multimodal Hashing and Its Application to Multimedia Retrieval.

    PubMed

    Zhen, Yi; Gao, Yue; Yeung, Dit-Yan; Zha, Hongyuan; Li, Xuelong

    2016-01-01

    In recent years, multimedia retrieval has sparked much research interest in the multimedia, pattern recognition, and data mining communities. Although some attempts have been made along this direction, performing fast multimodal search at very large scale still remains a major challenge in the area. While hashing-based methods have recently achieved promising successes in speeding-up large-scale similarity search, most existing methods are only designed for uni-modal data, making them unsuitable for multimodal multimedia retrieval. In this paper, we propose a new hashing-based method for fast multimodal multimedia retrieval. The method is based on spectral analysis of the correlation matrix of different modalities. We also develop an efficient algorithm that learns some parameters from the data distribution for obtaining the binary codes. We empirically compare our method with some state-of-the-art methods on two real-world multimedia data sets.

  11. A humming retrieval system based on music fingerprint

    NASA Astrophysics Data System (ADS)

    Han, Xingkai; Cao, Baiyu

    2011-10-01

    In this paper, we proposed an improved music information retrieval method utilizing the music fingerprint. The goal of this method is to represent the music with compressed musical information. Based on the selected MIDI files, which are generated automatically as our music target database, we evaluate the accuracy, effectiveness, and efficiency of this method. In this research we not only extract the feature sequence, which can represent the file effectively, from the query and melody database, but also make it possible for retrieving the results in an innovative way. We investigate on the influence of noise to the performance of our system. As experimental result shows, the retrieval accuracy arriving at up to91% without noise is pretty well

  12. Semantic Annotation for Biological Information Retrieval System

    PubMed Central

    Oshaiba, Mohamed Marouf Z.; El Houby, Enas M. F.; Salah, Akram

    2015-01-01

    Online literatures are increasing in a tremendous rate. Biological domain is one of the fast growing domains. Biological researchers face a problem finding what they are searching for effectively and efficiently. The aim of this research is to find documents that contain any combination of biological process and/or molecular function and/or cellular component. This research proposes a framework that helps researchers to retrieve meaningful documents related to their asserted terms based on gene ontology (GO). The system utilizes GO by semantically decomposing it into three subontologies (cellular component, biological process, and molecular function). Researcher has the flexibility to choose searching terms from any combination of the three subontologies. Document annotation is taking a place in this research to create an index of biological terms in documents to speed the searching process. Query expansion is used to infer semantically related terms to asserted terms. It increases the search meaningful results using the term synonyms and term relationships. The system uses a ranking method to order the retrieved documents based on the ranking weights. The proposed system achieves researchers' needs to find documents that fit the asserted terms semantically. PMID:25737720

  13. Semantic annotation for biological information retrieval system.

    PubMed

    Oshaiba, Mohamed Marouf Z; El Houby, Enas M F; Salah, Akram

    2015-01-01

    Online literatures are increasing in a tremendous rate. Biological domain is one of the fast growing domains. Biological researchers face a problem finding what they are searching for effectively and efficiently. The aim of this research is to find documents that contain any combination of biological process and/or molecular function and/or cellular component. This research proposes a framework that helps researchers to retrieve meaningful documents related to their asserted terms based on gene ontology (GO). The system utilizes GO by semantically decomposing it into three subontologies (cellular component, biological process, and molecular function). Researcher has the flexibility to choose searching terms from any combination of the three subontologies. Document annotation is taking a place in this research to create an index of biological terms in documents to speed the searching process. Query expansion is used to infer semantically related terms to asserted terms. It increases the search meaningful results using the term synonyms and term relationships. The system uses a ranking method to order the retrieved documents based on the ranking weights. The proposed system achieves researchers' needs to find documents that fit the asserted terms semantically.

  14. An Interactive Document Retrieval System.

    ERIC Educational Resources Information Center

    Carroll, D.E.; And Others

    The document retrieval system at Coordinated Science Laboratory is implemented on a Control Data 1604 computer system. Recorded information from each source article includes 1) conventional bibliographic data such as authorship, author affiliation, title, year of publication, etc., 2) detailed bibliographic data from each of the cited references,…

  15. Hypermedia and Free Text Retrieval.

    ERIC Educational Resources Information Center

    Dunlop, Mark D.; van Rijsbergen, C. J.

    1993-01-01

    Discusses access to nontextual documents in large multimedia document bases. A hybrid information retrieval model, using queries in a hypertext environment for location of browsing areas, is presented; and two experiments using cluster-based descriptions of content are reported. (23 references) (EA)

  16. A Theory of Memory Retrieval

    ERIC Educational Resources Information Center

    Ratcliff, Roger

    1978-01-01

    Cognitive psychology lacks explicit theories that encompass more than a single experimental paradigm. This research presents a theory of memory retrieval that not only applies over a range of paradigms but also deals with experimental data in greater depth and more detail than competing models. The theory provides a rationale for relating…

  17. Semantic Tools in Information Retrieval.

    ERIC Educational Resources Information Center

    Rubinoff, Morris; Stone, Don C.

    This report discusses the problem of the meansings of words used in information retrieval systems, and shows how semantic tools can aid in the communication which takes place between indexers and searchers via index terms. After treating the differing use of semantic tools in different types of systems, two tools (classification tables and…

  18. Information Retrieval for Ecological Syntheses

    ERIC Educational Resources Information Center

    Bayliss, Helen R.; Beyer, Fiona R.

    2015-01-01

    Research syntheses are increasingly being conducted within the fields of ecology and environmental management. Information retrieval is crucial in any synthesis in identifying data for inclusion whilst potentially reducing biases in the dataset gathered, yet the nature of ecological information provides several challenges when compared with…

  19. Information Retrieval in Virtual Universities

    ERIC Educational Resources Information Center

    Puustjärvi, Juha; Pöyry, Päivi

    2006-01-01

    Information retrieval in the context of virtual universities deals with the representation, organization, and access to learning objects. The representation and organization of learning objects should provide the learner with an easy access to the learning objects. In this article, we give an overview of the ONES system, and analyze the relevance…

  20. Hubble Space Telescope prescription retrieval.

    PubMed

    Redding, D; Dumont, P; Yu, J

    1993-04-01

    Prescription retrieval is a technique for directly estimating optical prescription parameters from images. We apply it to estimate the value of the Hubble Space Telescope primary mirror conic constant. Our results agree with other studies that examined primary-mirror test fixtures and results. In addition they show that small aberrations exist on the planetary-camera repeater optics.

  1. Photopolarimetric Retrievals of Snow Properties

    NASA Technical Reports Server (NTRS)

    Ottaviani, M.; van Diedenhoven, B.; Cairns, B.

    2015-01-01

    Polarimetric observations of snow surfaces, obtained in the 410-2264 nm range with the Research Scanning Polarimeter onboard the NASA ER-2 high-altitude aircraft, are analyzed and presented. These novel measurements are of interest to the remote sensing community because the overwhelming brightness of snow plagues aerosol and cloud retrievals based on airborne and spaceborne total reflection measurements. The spectral signatures of the polarized reflectance of snow are therefore worthwhile investigating in order to provide guidance for the adaptation of algorithms currently employed for the retrieval of aerosol properties over soil and vegetated surfaces. At the same time, the increased information content of polarimetric measurements allows for a meaningful characterization of the snow medium. In our case, the grains are modeled as hexagonal prisms of variable aspect ratios and microscale roughness, yielding retrievals of the grains' scattering asymmetry parameter, shape and size. The results agree with our previous findings based on a more limited data set, with the majority of retrievals leading to moderately rough crystals of extreme aspect ratios, for each scene corresponding to a single value of the asymmetry parameter.

  2. Telecommunications Networking in Online Retrieval.

    ERIC Educational Resources Information Center

    Mahon, Barry

    1991-01-01

    Reviews the development of telecommunications networks and describes current technology being used for online information retrieval. Highlights include use for military and research needs; experiences in Europe versus those in the United States; value-added networks (VANs); local area networks (LANs) and personal computers; and the Integrated…

  3. The Ecosystem of Information Retrieval

    ERIC Educational Resources Information Center

    Rodriguez-Munoz, Jose-Vicente; Martinez-Mendez, Francisco-Javier; Pastor-Sanchez, Juan-Antonio

    2012-01-01

    Introduction: This paper presents an initial proposal for a formal framework that, by studying the metric variables involved in information retrieval, can establish the sequence of events involved and how to perform it. Method: A systematic approach from the equations of Shannon and Weaver to establish the decidability of information retrieval…

  4. Artificial Intelligence and Information Retrieval.

    ERIC Educational Resources Information Center

    Teodorescu, Ioana

    1987-01-01

    Compares artificial intelligence and information retrieval paradigms for natural language understanding, reviews progress to date, and outlines the applicability of artificial intelligence to question answering systems. A list of principal artificial intelligence software for database front end systems is appended. (CLB)

  5. Research Toward Enhancing Retrieval Effectiveness.

    ERIC Educational Resources Information Center

    Schipma, Peter B.

    Two programs addressed the development of information retrieval systems useful to a variety of users. One program was designed to examine aspects of indexing and information display. Experiments with different indexing and display systems revealed that for good relevance judgements, a display with full citation, keyboards, and abstract is…

  6. Mixed Layers and Satellite Retrievals

    NASA Technical Reports Server (NTRS)

    Boers, R.

    1984-01-01

    As part of the process to determine whether it is possible to retrieve boundary layer structure with the current sounding techniques, temperature retievals were performed for radiosonde profiles that showed temperature inversions. It was found that when temperature inversions exceed 8 to 10 C a retrieval will indeed show a temperature increase with height over a limited vertical distance. For weaker inversions retrieved temperatures are generally smoothly decreasing with height. It is, however, impossible to determine the actual mixed layer height from the retrievals. Whether the water vapor channels could be used in observing mixed layer structure was investigated. Temperature inversions are accompanied by significant drops in relative humidity. While this effect is very pronounced in parts of the trade wind regimes with relative humidity drops of up to 60%, it is widespread in other areas of the ocean as well. A simulation experiment was performed in which brightness temperatures were computed for smooth temperature and humidity profiles and compared with those computed from inversion profiles.

  7. Platform for distributed image processing and image retrieval

    NASA Astrophysics Data System (ADS)

    Gueld, Mark O.; Thies, Christian J.; Fischer, Benedikt; Keysers, Daniel; Wein, Berthold B.; Lehmann, Thomas M.

    2003-06-01

    We describe a platform for the implementation of a system for content-based image retrieval in medical applications (IRMA). To cope with the constantly evolving medical knowledge, the platform offers a flexible feature model to store and uniformly access all feature types required within a multi-step retrieval approach. A structured generation history for each feature allows the automatic identification and re-use of already computed features. The platform uses directed acyclic graphs composed of processing steps and control elements to model arbitrary retrieval algorithms. This visually intuitive, data-flow oriented representation vastly improves the interdisciplinary communication between computer scientists and physicians during the development of new retrieval algorithms. The execution of the graphs is fully automated within the platform. Each processing step is modeled as a feature transformation. Due to a high degree of system transparency, both the implementation and the evaluation of retrieval algorithms are accelerated significantly. The platform uses a client-server architecture consisting of a central database, a central job scheduler, instances of a daemon service, and clients which embed user-implemented feature ansformations. Automatically distributed batch processing and distributed feature storage enable the cost-efficient use of an existing workstation cluster.

  8. Multi-clues image retrieval based on improved color invariants

    NASA Astrophysics Data System (ADS)

    Liu, Liu; Li, Jian-Xun

    2012-05-01

    At present, image retrieval has a great progress in indexing efficiency and memory usage, which mainly benefits from the utilization of the text retrieval technology, such as the bag-of-features (BOF) model and the inverted-file structure. Meanwhile, because the robust local feature invariants are selected to establish BOF, the retrieval precision of BOF is enhanced, especially when it is applied to a large-scale database. However, these local feature invariants mainly consider the geometric variance of the objects in the images, and thus the color information of the objects fails to be made use of. Because of the development of the information technology and Internet, the majority of our retrieval objects is color images. Therefore, retrieval performance can be further improved through proper utilization of the color information. We propose an improved method through analyzing the flaw of shadow-shading quasi-invariant. The response and performance of shadow-shading quasi-invariant for the object edge with the variance of lighting are enhanced. The color descriptors of the invariant regions are extracted and integrated into BOF based on the local feature. The robustness of the algorithm and the improvement of the performance are verified in the final experiments.

  9. High temperature application of retrievable MWD systems

    SciTech Connect

    Coe, R.; Saito, S.

    1995-12-31

    MWD systems are currently used to monitor the direction of wellbores. MWD systems with higher temperature capabilities are required to meet the needs of deep and geothermal drilling. A technique has been developed for geothermal drilling that allows a fully retrievable MWD system to be used in wells with formation temperatures in excess of 350{degrees}C. This operational technique involves use of the MWD system in combination with operational procedures adapted to cope with the need for continuous directional control while drilling. Descriptions of the drilling environment are given in areas of Japan where high temperature drilling is performed. Possible future requirements are reviewed. The MWD system is described giving current technical specifications and capabilities. The operational method for utilizing the MWD is detailed. A summary of successful applications is discussed and specific case studies given. The efficiency of using the technique is reviewed.

  10. Brewer Umkehr ozone profile retrievals

    NASA Astrophysics Data System (ADS)

    Petropavlovskikh, I. V.; Disterhoft, P.; Lantz, K. O.; Bhartia, P. K.; McPeters, R. D.; Flynn, L. E.; Oltmans, S. J.; Johnson, B. J.; Stanek, M.

    2011-12-01

    The Dobson Umkehr network has been a key data set for stratospheric ozone trend calculations (WMO Ozone assessments) and has earned its place as a benchmark network for stratospheric ozone profile observations. The Umkehr data has also been used to provide a long-term reference to the merging of the satellite ozone records (MOD), estimate the seasonal influence of an 11-year solar signal in the vertical distribution of stratospheric ozone, and to assess the ability of several remote and in-situ sensing systems in capturing ozone variability. It was found that Dobson Umkehr measurement errors were often comparable to errors derived for satellite and ozone-sounding methods. The Umkehr measurements are also available from the Brewer spectrophotometers [McElroy et al., 1995]. In 2005, the Dobson Umkehr algorithm (UMK04) was modified to retrieve ozone profile data from Brewer Umkehr measurements taken at two spectral channels [Petropavlovskikh et al, 2011]. The PC version of the Brewer algorithm was developed by M. Stanek (IOC, Canada and Czech Republic Meteorological Institute) in close collaboration with I. Petropavlovskikh. It was implemented at the NEUBrew network for operational processing of Umkehr data retrieved daily for all operational sites. The most recently developed Brewer ozone retrieval algorithm (MSBU) utilizes measurements that are currently available from the operational Brewer instruments. Umkehr measurements at multiple wavelength channels (similar to the satellite BUV method) and significantly reduced range of solar zenith angle are used for the twice a day operational ozone profile retrievals. Intercomparisons against ozone climatology, sounding, satellite overpasses and Dobson ozone datasets for NOASA/Goddard, Boulder, CO and MLO, HI sites are presented in this paper. The MSBU algorithm reduces noise in the intra-annual variability of the Brewer retrieved ozone as compared to the single pair ozone retrieval. Tropospheric ozone retrievals also

  11. Online Retrieval Systems Users Survey from Texas.

    ERIC Educational Resources Information Center

    White, Phillip M.

    Based on a survey of 160 Texas college and university libraries, this study reports on their access to and usage of 3 online information retrieval systems: Bibliographic Retrieval Services (BRS), Lockheed's DIALOG Information Services, and System Development Corporation's ORBIT Information Retrieval System. The study finds that 24 percent of all…

  12. Information Retrieval in Medicine: The SAPHIRE Experience.

    ERIC Educational Resources Information Center

    Hersh, William R.; Hickam, David

    1995-01-01

    Describes the SAPHIRE (Semantic and Probabilistic Heuristic Information Retrieval Environment) that was developed to identify optimal approaches to indexing, retrieval, and evaluation of information retrieval systems in the biomedical domain. Six evaluation studies that have been done with SAPHIRE are summarized and future challenges are…

  13. EXPERIMENTAL RETRIEVAL SYSTEMS STUDIES, REPORT NUMBER 3.

    ERIC Educational Resources Information Center

    ANDERSON, RONALD R.; AND OTHERS

    CONTENTS--(1) AN ASSOCIATIVITY TECHNIQUE FOR AUTOMATICALLY OPTIMIZING RETRIEVAL RESULTS BY RONALD R. ANDERSON. AN ASSOCIATIVE TECHNIQUE BY WHICH IT IS POSSIBLE TO AUTOMATICALLY EXPAND AND NARROW THE NUMBER OF DOCUMENTS RETRIEVED AND TO RETRIEVE DOCUMENTS RELATED TO A REQUEST EVEN THOUGH THEY MAY NOT BE INDEXED BY THE EXACT TERMS OF THE REQUEST IS…

  14. 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…

  15. A Fuzzy Model of Document Retrieval Systems

    ERIC Educational Resources Information Center

    Tahani, Valiollah

    1976-01-01

    This paper is concerned with the organization and retrieval of records in document retrieval systems which admit of imprecision in the form of fuzziness in document characterization and retrieval rules. A mathematical model for such systems, based on the theory of fuzzy sets, is introduced. (Author)

  16. Image Indexing and Retrieval by Content.

    ERIC Educational Resources Information Center

    Cawkell, Tony

    2000-01-01

    Reviews content-based image retrieval and discusses the increase in large picture databases that are now available. Describes some of the proceedings from the Brighton (United Kingdom) conference, including the retrieval of video clips; discusses image indexing; and provides examples of image indexing and retrieval projects. (Author/LRW)

  17. Intelligent Information Retrieval Using Rough Set Approximations.

    ERIC Educational Resources Information Center

    Srinivasan, Padmini

    1989-01-01

    Describes rough sets theory and discusses the advantages it offers for information retrieval, including the implicit inclusion of Boolean logic, term weighting, ranked retrieval output, and relevance feedback. Rough set formalism is compared to Boolean, vector, and fuzzy models of information retrieval and a small scale evaluation of rough sets is…

  18. Natural Language Information Retrieval: Progress Report.

    ERIC Educational Resources Information Center

    Perez-Carballo, Jose; Strzalkowski, Tomek

    2000-01-01

    Reports on the progress of the natural language information retrieval project, a joint effort led by GE (General Electric) Research, and its evaluation at the sixth TREC (Text Retrieval Conference). Discusses stream-based information retrieval, which uses alternative methods of document indexing; advanced linguistic streams; weighting; and query…

  19. Spectral embedded hashing for scalable image retrieval.

    PubMed

    Chen, Lin; Xu, Dong; Tsang, Ivor Wai-Hung; Li, Xuelong

    2014-07-01

    We propose a new graph based hashing method called spectral embedded hashing (SEH) for large-scale image retrieval. We first introduce a new regularizer into the objective function of the recent work spectral hashing to control the mismatch between the resultant hamming embedding and the low-dimensional data representation, which is obtained by using a linear regression function. This linear regression function can be employed to effectively handle the out-of-sample data, and the introduction of the new regularizer makes SEH better cope with the data sampled from a nonlinear manifold. Considering that SEH cannot efficiently cope with the high dimensional data, we further extend SEH to kernel SEH (KSEH) to improve the efficiency and effectiveness, in which a nonlinear regression function can also be employed to obtain the low dimensional data representation. We also develop a new method to efficiently solve the approximate solution for the eigenvalue decomposition problem in SEH and KSEH. Moreover, we show that some existing hashing methods are special cases of our KSEH. Our comprehensive experiments on CIFAR, Tiny-580K, NUS-WIDE, and Caltech-256 datasets clearly demonstrate the effectiveness of our methods.

  20. Toward an Episodic Context Account of Retrieval-Based Learning: Dissociating Retrieval Practice and Elaboration

    ERIC Educational Resources Information Center

    Lehman, Melissa; Smith, Megan A.; Karpicke, Jeffrey D.

    2014-01-01

    We tested the predictions of 2 explanations for retrieval-based learning; while the elaborative retrieval hypothesis assumes that the retrieval of studied information promotes the generation of semantically related information, which aids in later retrieval (Carpenter, 2009), the episodic context account proposed by Karpicke, Lehman, and Aue (in…

  1. Retrieval Attempts Enhance Learning, but Retrieval Success (versus Failure) Does Not Matter

    ERIC Educational Resources Information Center

    Kornell, Nate; Klein, Patricia Jacobs; Rawson, Katherine A.

    2015-01-01

    Retrieving information from memory enhances learning. We propose a 2-stage framework to explain the benefits of retrieval. Stage 1 takes place as one attempts to retrieve an answer, which activates knowledge related to the retrieval cue. Stage 2 begins when the answer becomes available, at which point appropriate connections are strengthened and…

  2. Phase retrieval for optical metrology

    NASA Astrophysics Data System (ADS)

    Pedrini, Giancarlo; Faridian, Ahmad; Singh, Alok Kumar; Osten, Wolfgang

    2014-11-01

    Phase retrieval methods have useful applications for optical imaging, metrology and 3D reconstruction. One such technique to recover the phase of the object wavefront is digital holography. In this paper we will show applications of digital holographic techniques for the time resolved measurement of deformation of microelectromechanical systems (MEMS) and for determination of residual stresses. Furthermore digital holography can be used for the investigations of microscopic samples and its resolution can be increased by using short wavelength and oblique illumination. We will see as well that dark-field digital holographic microscopy can be used to visualize biological specimens. A phase retrieval methods, which does not use a reference wave is also described in the last part of the paper.

  3. Automated information retrieval using CLIPS

    NASA Technical Reports Server (NTRS)

    Raines, Rodney Doyle, III; Beug, James Lewis

    1991-01-01

    Expert systems have considerable potential to assist computer users in managing the large volume of information available to them. One possible use of an expert system is to model the information retrieval interests of a human user and then make recommendations to the user as to articles of interest. At Cal Poly, a prototype expert system written in the C Language Integrated Production System (CLIPS) serves as an Automated Information Retrieval System (AIRS). AIRS monitors a user's reading preferences, develops a profile of the user, and then evaluates items returned from the information base. When prompted by the user, AIRS returns a list of items of interest to the user. In order to minimize the impact on system resources, AIRS is designed to run in the background during periods of light system use.

  4. Aerosols and Precipitation Retrievals over Eureka by Remote Sensing: Validation of Space Based Profiling Retrievals

    NASA Astrophysics Data System (ADS)

    Chaubey, J. P.; O'Neill, N. T.; Hudak, D. R.; Rodriguez, P.; Ivanescu, L.; Eloranta, E.; Duck, T.

    2014-12-01

    Aerosols and precipitation are among the agents responsible for the ongoing changes in the Arctic climate and the hydrological cycle. The seasonal variations of Arctic aerosols (Arctic haze for e.g.) are linked to the transport efficiency as well as precipitation (wet) scavenging. Aside from affecting aerosol concentrations, precipitation is an important hydrological variable that affects the moisture budget of the atmosphere. Aerosols, in turn, influence the vertical distribution of clouds and this induces changes in the precipitation pattern. The spatial and temporal sparsity of precipitation measurements over the Arctic region means that satellite remote sensing techniques take on an importance that considerably exceeds their role south of the Arctic circle. Radar reflectivity and snow profiles from CloudSat (in support of cloud and precipitation analyses) and backscattering measurements from CALIOP (investigations of aerosol and small cloud particle properties) can be used to study Arctic winter clouds and precipitation and the role of aerosols in their formation. In this study we attempt to validate satellite-based profiling retrievals of precipitation parameters using AHSRL (Arctic High Spectral Resolution Lidar), CRL (CANDAC Raman Lidar) and MMCR (Milli-Meter Cloud Radar) profiles acquired at the PEARL high-Arctic site in Eureka (80 °N, 86 °W), Nunavut, Canada. As part of the process of validating the profiling retrievals we aspire to learn more about the mechanisms controlling aerosol, cloud and precipitation inter-dynamics. In addition, ground-based, high-frequency observations of precipitation will be used for characterizing precipitation totals as well as the conditional probability of the type of precipitation (rain or snow) and thus to help understand and validate comparable information extracted from the satellite retrievals. We also aim to characterize different particle types using AHSRL and CRL depolarization profiles, MMCR Doppler velocity

  5. Desert Dust Satellite Retrieval Intercomparison

    NASA Technical Reports Server (NTRS)

    Carboni, E.; Thomas, G. E.; Sayer, A. M.; Siddans, R.; Poulsen, C. A.; Grainger, R. G.; Ahn, C.; Antoine, D.; Bevan, S.; Braak, R.; Brindley, H.; DeSouza-Mchado, S.; Deuze, J. L.; Diner, D.; Ducos, F.; Grey, W.; Hsu, C.; Kalashnikova, O. V.; Kahn, R.; North, P. R. J.; Salustro, C.; Smith, A.; Tanre, D.; Torres, O.; Veihelmann, B.

    2012-01-01

    This work provides a comparison of satellite retrievals of Saharan desert dust aerosol optical depth (AOD) during a strong dust event through March 2006. In this event, a large dust plume was transported over desert, vegetated, and ocean surfaces. The aim is to identify and understand the differences between current algorithms, and hence improve future retrieval algorithms. The satellite instruments considered are AATSR, AIRS, MERIS, MISR, MODIS, OMI, POLDER, and SEVIRI. An interesting aspect is that the different algorithms make use of different instrument characteristics to obtain retrievals over bright surfaces. These include multi-angle approaches (MISR, AATSR), polarisation measurements (POLDER), single-view approaches using solar wavelengths (OMI, MODIS), and the thermal infrared spectral region (SEVIRI, AIRS). Differences between instruments, together with the comparison of different retrieval algorithms applied to measurements from the same instrument, provide a unique insight into the performance and characteristics of the various techniques employed. As well as the intercomparison between different satellite products, the AODs have also been compared to co-located AERONET data. Despite the fact that the agreement between satellite and AERONET AODs is reasonably good for all of the datasets, there are significant differences between them when compared to each other, especially over land. These differences are partially due to differences in the algorithms, such as as20 sumptions about aerosol model and surface properties. However, in this comparison of spatially and temporally averaged data, at least as significant as these differences are sampling issues related to the actual footprint of each instrument on the heterogeneous aerosol field, cloud identification and the quality control flags of each dataset.

  6. Ethics, genomics, and information retrieval.

    PubMed

    Goodman, K W

    1996-05-01

    The union of genomics and computational information retrieval raises a number of ethical issues, including data sharing, database accuracy, group and subgroup stigma, and privacy and confidentiality. These issues are introduced and assigned a preliminary analysis which, it is hoped, may be of use in more sustained efforts to identify issues, solutions and potential guidelines, to stimulate education, and to strike the most appropriate balance between the rights of individuals and the needs of researchers and society.

  7. Retrieval of Mir Solar Array

    NASA Technical Reports Server (NTRS)

    Rutledge, Sharon K.; deGroh, Kim K.

    1999-01-01

    A Russian solar array panel removed in November 1997 from the non-articulating photovoltaic array on the Mir core module was returned to Earth on STS-89 in January 1998. The panel had been exposed to low Earth orbit (LEO) for 10 years prior to retrieval. The retrieval provided a unique opportunity to study the effects of the LEO environment on a functional solar array. To take advantage of this opportunity, a team composed of members from RSC-Energia (Russia), the Boeing Company, and the following NASA Centers--Johnson Space Center, Kennedy Space Center, Langley Research Center, Marshall Space Flight Center, and Lewis Research Center--was put together to analyze the array. After post-retrieval inspections at the Spacehab Facility at Kennedy in Florida, the array was shipped to Lewis in Cleveland for electrical performance tests, closeup photodocumentation, and removal of selected solar cells and blanket material. With approval from RSC-Energia, five cell pairs and their accompanying blanket and mesh material, and samples of painted handrail materials were selected for removal on the basis of their ability to provide degradation information. Sites were selected that provided different sizes and shapes of micrometeoroid impacts and different levels of surface contamination. These materials were then distributed among the team for round robin testing.

  8. Phase retrieval from speckle images.

    PubMed

    Rondeau, Xavier; Thiébaut, Eric; Tallon, Michel; Foy, Renaud

    2007-10-01

    In ground-based astronomy, the inverse problem of phase retrieval from speckle images is a means to calibrate static aberrations for correction by active optics. It can also be used to sense turbulent wavefronts. However, the number of local minima drastically increases with the turbulence strength, mainly because of phase wrapping ambiguities. Multifocal phase diversity has been considered to overcome some ambiguities of the phase retrieval problem. We propose an effective algorithm for phase retrieval from a single focused image. Our algorithm makes use of a global optimization strategy and an automatically tuned smoothness prior to overcome local minima and phase degeneracies. We push the limit of D/r(0)=4 achieved by Irwan and Lane [J. Opt. Soc. Am. A.15, 2302 (1998)] up to D/r(0)=11, which is a major improvement owing to the drastic increase in the problem complexity. We estimate the performances of our approach from consistent simulations for different turbulence strengths and noise levels (down to 1500 photons per image). We also investigate the benefit of temporal correlation.

  9. THE RETRIEVAL KNOWLEDGE CENTER EVALUATION OF LOW TANK LEVEL MIXING TECHNOLOGIES FOR DOE HIGH LEVEL WASTE TANK RETRIEVAL 10516

    SciTech Connect

    Fellinger, A.

    2009-12-08

    The Department of Energy (DOE) Complex has over two-hundred underground storage tanks containing over 80-million gallons of legacy waste from the production of nuclear weapons. The majority of the waste is located at four major sites across the nation and is planned for treatment over a period of almost forty years. The DOE Office of Technology Innovation & Development within the Office of Environmental Management (DOE-EM) sponsors technology research and development programs to support processing advancements and technology maturation designed to improve the costs and schedule for disposal of the waste and closure of the tanks. Within the waste processing focus area are numerous technical initiatives which included the development of a suite of waste removal technologies to address the need for proven equipment and techniques to remove high level radioactive wastes from the waste tanks that are now over fifty years old. In an effort to enhance the efficiency of waste retrieval operations, the DOE-EM Office of Technology Innovation & Development funded an effort to improve communications and information sharing between the DOE's major waste tank locations as it relates to retrieval. The task, dubbed the Retrieval Knowledge Center (RKC) was co-lead by the Savannah River National Laboratory (SRNL) and the Pacific Northwest National Laboratory (PNNL) with core team members representing the Oak Ridge and Idaho sites, as well as, site contractors responsible for waste tank operations. One of the greatest challenges to the processing and closure of many of the tanks is complete removal of all tank contents. Sizeable challenges exist for retrieving waste from High Level Waste (HLW) tanks; with complications that are not normally found with tank retrieval in commercial applications. Technologies currently in use for waste retrieval are generally adequate for bulk removal; however, removal of tank heels, the materials settled in the bottom of the tank, using the same

  10. A Unified Mathematical Definition of Classical Information Retrieval.

    ERIC Educational Resources Information Center

    Dominich, Sandor

    2000-01-01

    Presents a unified mathematical definition for the classical models of information retrieval and identifies a mathematical structure behind relevance feedback. Highlights include vector information retrieval; probabilistic information retrieval; and similarity information retrieval. (Contains 118 references.) (Author/LRW)

  11. Statistical Techniques for Efficient Indexing and Retrieval of Document Images

    ERIC Educational Resources Information Center

    Bhardwaj, Anurag

    2010-01-01

    We have developed statistical techniques to improve the performance of document image search systems where the intermediate step of OCR based transcription is not used. Previous research in this area has largely focused on challenges pertaining to generation of small lexicons for processing handwritten documents and enhancement of poor quality…

  12. An Efficient Method for Rare Spectra Retrieval in Astronomical Databases

    NASA Astrophysics Data System (ADS)

    Du, Changde; Luo, Ali; Yang, Haifeng; Hou, Wen; Guo, Yanxin

    2016-03-01

    One of the most important aims of astronomical data mining is to systematically search for specific rare objects in a massive spectral data set, given a small fraction of identified samples with the same type. Most existing methods are mainly based on binary classification, which usually suffers from incompleteness when there are too few known samples. Rank-based methods could provide good solutions for such cases. After investigating several algorithms, a method combining a bipartite ranking model with bootstrap aggregating techniques was developed in this paper. The method was applied while searching for carbon stars in the spectral data of Sloan Digital Sky Survey Data Release 10 and compared with several other popular methods used for data mining. Experimental results validate that the proposed method is not only the most effective but also the least time-consuming technique among its competitors when searching for rare spectra in a large but unlabeled data set.

  13. Using Induction to Refine Information Retrieval Strategies

    NASA Technical Reports Server (NTRS)

    Baudin, Catherine; Pell, Barney; Kedar, Smadar

    1994-01-01

    Conceptual information retrieval systems use structured document indices, domain knowledge and a set of heuristic retrieval strategies to match user queries with a set of indices describing the document's content. Such retrieval strategies increase the set of relevant documents retrieved (increase recall), but at the expense of returning additional irrelevant documents (decrease precision). Usually in conceptual information retrieval systems this tradeoff is managed by hand and with difficulty. This paper discusses ways of managing this tradeoff by the application of standard induction algorithms to refine the retrieval strategies in an engineering design domain. We gathered examples of query/retrieval pairs during the system's operation using feedback from a user on the retrieved information. We then fed these examples to the induction algorithm and generated decision trees that refine the existing set of retrieval strategies. We found that (1) induction improved the precision on a set of queries generated by another user, without a significant loss in recall, and (2) in an interactive mode, the decision trees pointed out flaws in the retrieval and indexing knowledge and suggested ways to refine the retrieval strategies.

  14. Retrieval of buried depleted uranium from the T-1 trench

    SciTech Connect

    Burmeister, M.; Castaneda, N.; Greengard, T. |; Hull, C.; Barbour, D.; Quapp, W.J.

    1998-07-01

    The Trench 1 remediation project will be conducted this year to retrieve depleted uranium and other associated materials from a trench at Rocky Flats Environmental Technology Site. The excavated materials will be segregated and stabilized for shipment. The depleted uranium will be treated at an offsite facility which utilizes a novel approach for waste minimization and disposal through utilization of a combination of uranium recycling and volume efficient uranium stabilization.

  15. The CIRSE Retrievable IVC Filter Registry: Retrieval Success Rates in Practice.

    PubMed

    Lee, M J; Valenti, D; de Gregorio, M A; Minocha, J; Rimon, U; Pellerin, O

    2015-12-01

    CIRSE established a registry of retrievable filter use with the primary aim of determining the success of IVC Filter retrieval and associated complications. Secondary endpoints included filter indications, imaging strategies before retrieval, filter dwell times, and anticoagulation status. A web-based electronic registry was hosted between 01/12/2010 and 30/06/2012. Data entry occurred at the date of IVC filter retrieval and included items such as filter type, indication for filter insertion, access route, dwell time, retrieval success, complications, reasons for failed retrieval, and anticoagulation status. 671 filter retrievals were entered (male:female 333:295, mean age 55, median 57). Retrieval data were not entered in 43/671 leaving 628 patients for analysis. The 4 commonest retrievable filters used were the Celect in 182 patients, the OPTEASE in 161, ALN in 120, and Gunther Tulip in 98. Filters were inserted for absolute indications 40%, relative indications in 31%, and prophylactic in 24%, with 5% missing. Mean filter dwell time was 90 days. Filters were successfully retrieved in 576/628 patients (92%). The mean dwell time for successful retrievals was 85 days versus 145 days for unsuccessful retrievals (p = 0.001). Major complications occurred in 2 patients (0.03%). In summary, the CIRSE retrievable filter registry demonstrates a retrieval rate of 92% across a range of filter types, with a low major complication rate, reflecting current practice. There is an increase in trend of retrievable filter use for relative and prophylactic indications. PMID:25933644

  16. Design of a polarization-insensitive superconducting nanowire single photon detector with high detection efficiency

    NASA Astrophysics Data System (ADS)

    Zheng, Fan; Xu, Ruiying; Zhu, Guanghao; Jin, Biaobing; Kang, Lin; Xu, Weiwei; Chen, Jian; Wu, Peiheng

    2016-03-01

    Superconducting nanowire single photon detectors (SNSPDs) deliver superior performance over their competitors in the near-infrared regime. However, these detectors have an intrinsic polarization dependence on the incident wave because of their one-dimensional meander structure. In this paper, we propose an approach to eliminate the polarization sensitivity of SNSPDs by using near-field optics to increase the absorption of SNSPDs under transverse magnetic (TM) illumination. In addition, an optical cavity is added to our SNSPD to obtain nearly perfect absorption of the incident wave. Numerical simulations show that the maximum absorption of a designed SNSPD can reach 96% at 1550 nm, and indicate that the absorption difference between transverse electric (TE) and TM polarization is less than 0.5% across a wavelength window of 300 nm. Our work provides the first demonstration of the possibility of designing a polarization-insensitive and highly efficient SNSPD without performing device symmetry improvements.

  17. Design of a polarization-insensitive superconducting nanowire single photon detector with high detection efficiency.

    PubMed

    Zheng, Fan; Xu, Ruiying; Zhu, Guanghao; Jin, Biaobing; Kang, Lin; Xu, Weiwei; Chen, Jian; Wu, Peiheng

    2016-01-01

    Superconducting nanowire single photon detectors (SNSPDs) deliver superior performance over their competitors in the near-infrared regime. However, these detectors have an intrinsic polarization dependence on the incident wave because of their one-dimensional meander structure. In this paper, we propose an approach to eliminate the polarization sensitivity of SNSPDs by using near-field optics to increase the absorption of SNSPDs under transverse magnetic (TM) illumination. In addition, an optical cavity is added to our SNSPD to obtain nearly perfect absorption of the incident wave. Numerical simulations show that the maximum absorption of a designed SNSPD can reach 96% at 1550 nm, and indicate that the absorption difference between transverse electric (TE) and TM polarization is less than 0.5% across a wavelength window of 300 nm. Our work provides the first demonstration of the possibility of designing a polarization-insensitive and highly efficient SNSPD without performing device symmetry improvements. PMID:26948672

  18. Design of a polarization-insensitive superconducting nanowire single photon detector with high detection efficiency

    PubMed Central

    Zheng, Fan; Xu, Ruiying; Zhu, Guanghao; Jin, Biaobing; Kang, Lin; Xu, Weiwei; Chen, Jian; Wu, Peiheng

    2016-01-01

    Superconducting nanowire single photon detectors (SNSPDs) deliver superior performance over their competitors in the near-infrared regime. However, these detectors have an intrinsic polarization dependence on the incident wave because of their one-dimensional meander structure. In this paper, we propose an approach to eliminate the polarization sensitivity of SNSPDs by using near-field optics to increase the absorption of SNSPDs under transverse magnetic (TM) illumination. In addition, an optical cavity is added to our SNSPD to obtain nearly perfect absorption of the incident wave. Numerical simulations show that the maximum absorption of a designed SNSPD can reach 96% at 1550 nm, and indicate that the absorption difference between transverse electric (TE) and TM polarization is less than 0.5% across a wavelength window of 300 nm. Our work provides the first demonstration of the possibility of designing a polarization-insensitive and highly efficient SNSPD without performing device symmetry improvements. PMID:26948672

  19. Advanced parameter retrievals for metamaterial slabs using an inhomogeneous model

    NASA Astrophysics Data System (ADS)

    Li Hou, Ling; Chin, Jessie Yao; Yang, Xin Mi; Lin, Xian Qi; Liu, Ruopeng; Xu, Fu Yong; Cui, Tie Jun

    2008-03-01

    The S-parameter retrieval has proved to be an efficient approach to obtain electromagnetic parameters of metamaterials from reflection and transmission coefficients, where a slab of metamaterial with finite thickness is regarded as a homogeneous medium slab with the same thickness [D. R. Smith and S. Schultz, Phys. Rev. B 65, 195104 (2002)]. However, metamaterial structures composed of subwavelength unit cells are different from homogeneous materials, and the conventional retrieval method is, under certain circumstances, not accurate enough. In this paper, we propose an advanced parameter retrieval method for metamaterial slabs using an inhomogeneous model. Due to the coupling effects of unit cells in a metamaterial slab, the roles of edge and inner cells in the slab are different. Hence, the corresponding equivalent medium parameters are different, which results in the inhomogeneous property of the metamaterial slab. We propose the retrievals of medium parameters for edge and inner cells from S parameters by considering two- and three-cell metamaterial slabs, respectively. Then we set up an inhomogeneous three-layer model for arbitrary metamaterial slabs, which is much more accurate than the conventional homogeneous model. Numerical simulations verify the above conclusions.

  20. Innovative grout/retrieval demonstration final report

    SciTech Connect

    Loomis, G.G.; Thompson, D.N.

    1995-01-01

    This report presents the results of an evaluation of an innovative retrieval technique for buried transuranic waste. Application of this retrieval technique was originally designed for full pit retrieval; however, it applies equally to a hot spot retrieval technology. The technique involves grouting the buried soil waste matrix with a jet grouting procedure, applying an expansive demolition grout to the matrix, and retrieving the debris. The grouted matrix provides an agglomeration of fine soil particles and contaminants resulting in an inherent contamination control during the dusty retrieval process. A full-scale field demonstration of this retrieval technique was performed on a simulated waste pit at the Idaho National Engineering Laboratory. Details are reported on all phases of this proof-of-concept demonstration including pit construction, jet grouting activities, application of the demolition grout, and actual retrieval of the grouted pit. A quantitative evaluation of aerosolized soils and rare earth tracer spread is given for all phases of the demonstration, and these results are compared to a baseline retrieval activity using conventional retrieval means. 8 refs., 47 figs., 10 tabs.

  1. Study of query expansion techniques and their application in the biomedical information retrieval.

    PubMed

    Rivas, A R; Iglesias, E L; Borrajo, L

    2014-01-01

    Information Retrieval focuses on finding documents whose content matches with a user query from a large document collection. As formulating well-designed queries is difficult for most users, it is necessary to use query expansion to retrieve relevant information. Query expansion techniques are widely applied for improving the efficiency of the textual information retrieval systems. These techniques help to overcome vocabulary mismatch issues by expanding the original query with additional relevant terms and reweighting the terms in the expanded query. In this paper, different text preprocessing and query expansion approaches are combined to improve the documents initially retrieved by a query in a scientific documental database. A corpus belonging to MEDLINE, called Cystic Fibrosis, is used as a knowledge source. Experimental results show that the proposed combinations of techniques greatly enhance the efficiency obtained by traditional queries.

  2. The validation of AIRS retrievals

    NASA Technical Reports Server (NTRS)

    Fetzer, Eric J.; Olsen, Edward T.; Chen, Luke L.; Hagan, Denise E.; Fishbein, Evan; McMillin, Larry; Zhou, Jiang; McMillan, Wallace W.

    2003-01-01

    The initial validation of Atmospheric Infrared Sounder (SIRS) experiment retrievals were completed in August 2003 as part of public release of version 3.0 data. The associated analyses are reported at http://daac.gsfc.nasa.gov/atmodyn/airs/, where data may be accessed. Here we describe some of those analyses, with an emphasis on cloud cleared radiances, atmospheric temperature profiles, sea surface temperature, total water vapor and atmospheric water vapor profiles. The results are applicable over ocean in the latitude band +/-40 degrees.

  3. Compressed sensing for phase retrieval.

    PubMed

    Newton, Marcus C

    2012-05-01

    To date there are several iterative techniques that enjoy moderate success when reconstructing phase information, where only intensity measurements are made. There remains, however, a number of cases in which conventional approaches are unsuccessful. In the last decade, the theory of compressed sensing has emerged and provides a route to solving convex optimisation problems exactly via ℓ(1)-norm minimization. Here the application of compressed sensing to phase retrieval in a nonconvex setting is reported. An algorithm is presented that applies reweighted ℓ(1)-norm minimization to yield accurate reconstruction where conventional methods fail.

  4. Phase retrieval with prior information.

    PubMed

    Irwan, R; Lane, R G

    1998-09-01

    An algorithm for phase retrieval with Bayesian statistics is discussed. It is shown how the statistics of Kolmogorov turbulence can be used to compute the likelihood for a particular phase screen. This likelihood is then added to that of the observed data to produce a functional that is maximized directly by use of conjugate gradient maximization. It is shown that although this can significantly improve the quality of the phase estimate,the issue is complicated by local maxima introduced by the possibility of phase wrapping. The causes of the local maxima are analyzed, and a method that increases the likelihood of convergence to the global maximum is presented.

  5. Controlling storage/retrieval system

    SciTech Connect

    Conrad, S.J.

    1984-11-15

    This article discusses the combination of a vertical carousel storage and retrieval system and computerized material requirements planning and inventory control which has resulted in a material handling system that is saving money and increasing productivity for Hewlett-Packard. The combination is also proving to be very versatile, with different plants opting for various levels of automation to suit their particular needs. This article reviews what Hewlett-Packard is doing and discusses why the company decided to purchase high-density vertical carousels. Three company divisions' needs and operations are outlined.

  6. Efficient spin filter and spin valve in a single-molecule magnet Fe{sub 4} between two graphene electrodes

    SciTech Connect

    Zu, Feng-Xia; Gao, Guo-Ying; Fu, Hua-Hua; Peng, Li; Yao, Kai-Lun; Xiong, Lun; Zhu, Si-Cong

    2015-12-21

    We propose a magnetic molecular junction consisting of a single-molecule magnet Fe{sub 4} connected two graphene electrodes and investigate transport properties, using the nonequilibrium Green's function method in combination with spin-polarized density-functional theory. The results show that the device can be used as a nearly perfect spin filter with efficiency approaching 100%. Our calculations provide crucial microscopic information how the four iron cores of the chemical structure are responsible for the spin-resolved transmissions. Moreover, it is also found that the device behaves as a highly efficient spin valve, which is an excellent candidate for spintronics of molecular devices. The idea of combining single-molecule magnets with graphene provides a direction in designing a new class of molecular spintronic devices.

  7. Sperm retrieval during critical illness.

    PubMed

    Powner, David J; Rumohr, Jon A; Lipshultz, Larry I

    2010-06-01

    Objective of this study is to review technical methods to retrieve sperm from critically ill/injured patients after an appropriate family request, possible harmful effects on sperm production/function by ICU medications or concurrent illnesses, and ethical considerations for hospitals and care providers in providing this resource. Design used for this study includes: literature review, PubMed 1998-2009, and authors' files. There are no interventions. In conclusion, although successful and unsuccessful pregnancies following sperm removal from critically-ill patients are reported, no firm probability predictions for either result are known. Acute and chronic diseases that effect the hypothalamic-pituitary-gonadal axis and multiple medications common to the ICU may reduce sperm production or function. Retrieval methods before and after cardio-respiratory death differ and often require intracytoplasmic sperm injection or other in vitro fertilization techniques to achieve a subsequent pregnancy. The proactive development of a collaborative policy/procedure to identify appropriate roles for the hospital, its employees, and affiliated critical care and urology physicians is strongly recommended.

  8. Antigen retrieval techniques: current perspectives.

    PubMed

    Shi, S R; Cote, R J; Taylor, C R

    2001-08-01

    Development of the antigen retrieval (AR) technique, a simple method of boiling archival paraffin-embedded tissue sections in water to enhance the signal of immunohistochemistry (IHC), was the fruit of pioneering efforts guided by the philosophy of rendering IHC applicable to routine formalin-fixed, paraffin-embedded tissues for wide application of IHC in research and clinical pathology. On the basis of thousands of articles and many reviews, a book has recently been published that summarizes basic principles for practice and further development of the AR technique. Major topics with respect to several critical issues, such as the definition, application, technical principles, and further studies of the AR technique, are highlighted in this article. In particular, a further application of the heat-induced retrieval approach for sufficient extraction of nucleic acids in addition to proteins, and standardization of routine IHC based on the AR technique in terms of a test battery approach, are also addressed. Furthermore, understanding the mechanism of the AR technique may shed light on facilitating the development of molecular morphology.

  9. The Aquarius Salinity Retrieval Algorithm

    NASA Technical Reports Server (NTRS)

    Meissner, Thomas; Wentz, Frank; Hilburn, Kyle; Lagerloef, Gary; Le Vine, David

    2012-01-01

    The first part of this presentation gives an overview over the Aquarius salinity retrieval algorithm. The instrument calibration [2] converts Aquarius radiometer counts into antenna temperatures (TA). The salinity retrieval algorithm converts those TA into brightness temperatures (TB) at a flat ocean surface. As a first step, contributions arising from the intrusion of solar, lunar and galactic radiation are subtracted. The antenna pattern correction (APC) removes the effects of cross-polarization contamination and spillover. The Aquarius radiometer measures the 3rd Stokes parameter in addition to vertical (v) and horizontal (h) polarizations, which allows for an easy removal of ionospheric Faraday rotation. The atmospheric absorption at L-band is almost entirely due to molecular oxygen, which can be calculated based on auxiliary input fields from numerical weather prediction models and then successively removed from the TB. The final step in the TA to TB conversion is the correction for the roughness of the sea surface due to wind, which is addressed in more detail in section 3. The TB of the flat ocean surface can now be matched to a salinity value using a surface emission model that is based on a model for the dielectric constant of sea water [3], [4] and an auxiliary field for the sea surface temperature. In the current processing only v-pol TB are used for this last step.

  10. Retrieving fear memories, as time goes by….

    PubMed

    Do Monte, F H; Quirk, G J; Li, B; Penzo, M A

    2016-08-01

    Research in fear conditioning has provided a comprehensive picture of the neuronal circuit underlying the formation of fear memories. In contrast, our understanding of the retrieval of fear memories is much more limited. This disparity may stem from the fact that fear memories are not rigid, but reorganize over time. To bring some clarity and raise awareness about the time-dependent dynamics of retrieval circuits, we review current evidence on the neuronal circuitry participating in fear memory retrieval at both early and late time points following auditory fear conditioning. We focus on the temporal recruitment of the paraventricular nucleus of the thalamus (PVT) for the retrieval and maintenance of fear memories. Finally, we speculate as to why retrieval circuits change with time, and consider the functional strategy of recruiting structures not previously considered as part of the retrieval circuit.

  11. Retrieving fear memories, as time goes by….

    PubMed

    Do Monte, F H; Quirk, G J; Li, B; Penzo, M A

    2016-08-01

    Research in fear conditioning has provided a comprehensive picture of the neuronal circuit underlying the formation of fear memories. In contrast, our understanding of the retrieval of fear memories is much more limited. This disparity may stem from the fact that fear memories are not rigid, but reorganize over time. To bring some clarity and raise awareness about the time-dependent dynamics of retrieval circuits, we review current evidence on the neuronal circuitry participating in fear memory retrieval at both early and late time points following auditory fear conditioning. We focus on the temporal recruitment of the paraventricular nucleus of the thalamus (PVT) for the retrieval and maintenance of fear memories. Finally, we speculate as to why retrieval circuits change with time, and consider the functional strategy of recruiting structures not previously considered as part of the retrieval circuit. PMID:27217148

  12. ARM Cloud Retrieval Ensemble Data Set (ACRED)

    SciTech Connect

    Zhao, C; Xie, S; Klein, SA; McCoy, R; Comstock, JM; Delanoë, J; Deng, M; Dunn, M; Hogan, RJ; Jensen, MP; Mace, GG; McFarlane, SA; O’Connor, EJ; Protat, A; Shupe, MD; Turner, D; Wang, Z

    2011-09-12

    This document describes a new Atmospheric Radiation Measurement (ARM) data set, the ARM Cloud Retrieval Ensemble Data Set (ACRED), which is created by assembling nine existing ground-based cloud retrievals of ARM measurements from different cloud retrieval algorithms. The current version of ACRED includes an hourly average of nine ground-based retrievals with vertical resolution of 45 m for 512 layers. The techniques used for the nine cloud retrievals are briefly described in this document. This document also outlines the ACRED data availability, variables, and the nine retrieval products. Technical details about the generation of ACRED, such as the methods used for time average and vertical re-grid, are also provided.

  13. On the Efficiency of Best-Match Cluster Searches.

    ERIC Educational Resources Information Center

    Can, Fazli

    1994-01-01

    Discussion of relevancy in information retrieval systems focuses on an analysis of the efficiency of various cluster-based retrieval (CBR) strategies. A method for combining CBR and inverted index search is proposed that is cost effective in terms of time efficiency; and results of experiments are reported. (Contains 32 references.) (LRW)

  14. PICTURES OF A SUSPECT-TRU RETRIEVAL

    SciTech Connect

    GADD, R.R.

    2007-05-24

    Retrieving ''suspect'' transuranic (TRU) waste from the Hanford Site's low-level waste burial grounds is a tall order, due to conditions that have changed as the work progresses. Project personnel developed several new methods for handling the waste that other retrieval operations may find useful. The Waste Retrieval Project is operated by Fluor Hanford, a prime contractor for the U.S. Department of Energy's Richland Operations Office since 1996.

  15. Post-mortem sperm retrieval in Australasia.

    PubMed

    Kroon, Benjamin; Kroon, Frederick; Holt, Saul; Wong, Brittany; Yazdani, Anusch

    2012-10-01

    Post-mortem Sperm Retrieval (PMSR) is seldom requested in Australasia. The retrieval of sperm is permitted only by prior written consent or by order of the court. Sperm should be retrieved within 24 h following death; however, collection within 36 h may still be successful. The clinical response to such a request must be mindful of complex ethical and legal considerations. Clear, accessible and consistent law in this area would benefit medical, legal and societal stakeholders. PMID:22862141

  16. MIARS: a medical image retrieval system.

    PubMed

    Mueen, A; Zainuddin, R; Baba, M Sapiyan

    2010-10-01

    The next generation of medical information system will integrate multimedia data to assist physicians in clinical decision-making, diagnoses, teaching, and research. This paper describes MIARS (Medical Image Annotation and Retrieval System). MIARS not only provides automatic annotation, but also supports text based as well as image based retrieval strategies, which play important roles in medical training, research, and diagnostics. The system utilizes three trained classifiers, which are trained using training images. The goal of these classifiers is to provide multi-level automatic annotation. Another main purpose of the MIARS system is to study image semantic retrieval strategy by which images can be retrieved according to different levels of annotation.

  17. Supervised learning of semantic classes for image annotation and retrieval.

    PubMed

    Carneiro, Gustavo; Chan, Antoni B; Moreno, Pedro J; Vasconcelos, Nuno

    2007-03-01

    A probabilistic formulation for semantic image annotation and retrieval is proposed. Annotation and retrieval are posed as classification problems where each class is defined as the group of database images labeled with a common semantic label. It is shown that, by establishing this one-to-one correspondence between semantic labels and semantic classes, a minimum probability of error annotation and retrieval are feasible with algorithms that are 1) conceptually simple, 2) computationally efficient, and 3) do not require prior semantic segmentation of training images. In particular, images are represented as bags of localized feature vectors, a mixture density estimated for each image, and the mixtures associated with all images annotated with a common semantic label pooled into a density estimate for the corresponding semantic class. This pooling is justified by a multiple instance learning argument and performed efficiently with a hierarchical extension of expectation-maximization. The benefits of the supervised formulation over the more complex, and currently popular, joint modeling of semantic label and visual feature distributions are illustrated through theoretical arguments and extensive experiments. The supervised formulation is shown to achieve higher accuracy than various previously published methods at a fraction of their computational cost. Finally, the proposed method is shown to be fairly robust to parameter tuning.

  18. Towards Adaptive High-Resolution Images Retrieval Schemes

    NASA Astrophysics Data System (ADS)

    Kourgli, A.; Sebai, H.; Bouteldja, S.; Oukil, Y.

    2016-06-01

    Nowadays, content-based image-retrieval techniques constitute powerful tools for archiving and mining of large remote sensing image databases. High spatial resolution images are complex and differ widely in their content, even in the same category. All images are more or less textured and structured. During the last decade, different approaches for the retrieval of this type of images have been proposed. They differ mainly in the type of features extracted. As these features are supposed to efficiently represent the query image, they should be adapted to all kind of images contained in the database. However, if the image to recognize is somewhat or very structured, a shape feature will be somewhat or very effective. While if the image is composed of a single texture, a parameter reflecting the texture of the image will reveal more efficient. This yields to use adaptive schemes. For this purpose, we propose to investigate this idea to adapt the retrieval scheme to image nature. This is achieved by making some preliminary analysis so that indexing stage becomes supervised. First results obtained show that by this way, simple methods can give equal performances to those obtained using complex methods such as the ones based on the creation of bag of visual word using SIFT (Scale Invariant Feature Transform) descriptors and those based on multi scale features extraction using wavelets and steerable pyramids.

  19. TANK WASTE RETRIEVAL LESSONS LEARNED AT THE HANFORD SITE

    SciTech Connect

    DODD, R.A.

    2006-01-17

    One of the environmental remediation challenges facing the nation is the retrieval and permanent disposal of approximately 90 million gallons of radioactive waste stored in underground tanks at the US Department of Energy (DOE) facilities. The Hanford Site is located in southeastern Washington State and stores roughly 60% of this waste. An estimated 53 million gallons of high-level, transuranic, and low-level radioactive waste is stored underground in 149 single-shell tanks (SSTs) and 28 newer double-shell tanks (DSTs) at the Hanford Site. These SSTs range in size from 55,000 gallons to 1,000,000 gallon capacity. Approximately 30 million gallons of this waste is stored in SSTs. The SSTs were constructed between 1943 and 1964 and all have exceeded the nominal 20-year design life. Sixty-seven SSTs are known or suspected to have leaked an estimated 1,000,000 gallons of waste. The risk of additional SST leakage has been greatly reduced by removing more than 3 million gallons of interstitial liquids and supernatant and transferring the waste to the DST system since 1997 as part of the interim stabilization program. Retrieval of SST saltcake and sludge waste is underway to further reduce risks and stage feed materials for the Hanford Site Waste Treatment Plant. This paper presents lessons learned from retrieval of tank waste at the Hanford Site and discusses how this information is used to optimize retrieval system efficiency, improve overall cost effectiveness of retrieval operations, and ensure that HFFACO requirements are met.

  20. On-Demand Single Photons with High Extraction Efficiency and Near-Unity Indistinguishability from a Resonantly Driven Quantum Dot in a Micropillar.

    PubMed

    Ding, Xing; He, Yu; Duan, Z-C; Gregersen, Niels; Chen, M-C; Unsleber, S; Maier, S; Schneider, Christian; Kamp, Martin; Höfling, Sven; Lu, Chao-Yang; Pan, Jian-Wei

    2016-01-15

    Scalable photonic quantum technologies require on-demand single-photon sources with simultaneously high levels of purity, indistinguishability, and efficiency. These key features, however, have only been demonstrated separately in previous experiments. Here, by s-shell pulsed resonant excitation of a Purcell-enhanced quantum dot-micropillar system, we deterministically generate resonance fluorescence single photons which, at π pulse excitation, have an extraction efficiency of 66%, single-photon purity of 99.1%, and photon indistinguishability of 98.5%. Such a single-photon source for the first time combines the features of high efficiency and near-perfect levels of purity and indistinguishabilty, and thus opens the way to multiphoton experiments with semiconductor quantum dots.

  1. On-Demand Single Photons with High Extraction Efficiency and Near-Unity Indistinguishability from a Resonantly Driven Quantum Dot in a Micropillar.

    PubMed

    Ding, Xing; He, Yu; Duan, Z-C; Gregersen, Niels; Chen, M-C; Unsleber, S; Maier, S; Schneider, Christian; Kamp, Martin; Höfling, Sven; Lu, Chao-Yang; Pan, Jian-Wei

    2016-01-15

    Scalable photonic quantum technologies require on-demand single-photon sources with simultaneously high levels of purity, indistinguishability, and efficiency. These key features, however, have only been demonstrated separately in previous experiments. Here, by s-shell pulsed resonant excitation of a Purcell-enhanced quantum dot-micropillar system, we deterministically generate resonance fluorescence single photons which, at π pulse excitation, have an extraction efficiency of 66%, single-photon purity of 99.1%, and photon indistinguishability of 98.5%. Such a single-photon source for the first time combines the features of high efficiency and near-perfect levels of purity and indistinguishabilty, and thus opens the way to multiphoton experiments with semiconductor quantum dots. PMID:26824530

  2. On-Demand Paging and Retrieval in a Semiautomated Environment at Georgia Southern University: The First Two Years

    ERIC Educational Resources Information Center

    Smith, Fred W.

    2010-01-01

    An automated retrieval system, adapted from a commercial warehouse application, has been installed at Georgia Southern University and has been well accepted by patrons and library personnel due to its reliability, efficiency, cost-effectiveness, and responsiveness. (Contains 1 figure.)

  3. Compression and Progressive Retrieval of Multi-Dimensional Sensor Data

    NASA Astrophysics Data System (ADS)

    Lorkowski, P.; Brinkhoff, T.

    2016-06-01

    Since the emergence of sensor data streams, increasing amounts of observations have to be transmitted, stored and retrieved. Performing these tasks at the granularity of single points would mean an inappropriate waste of resources. Thus, we propose a concept that performs a partitioning of observations by spatial, temporal or other criteria (or a combination of them) into data segments. We exploit the resulting proximity (according to the partitioning dimension(s)) within each data segment for compression and efficient data retrieval. While in principle allowing lossless compression, it can also be used for progressive transmission with increasing accuracy wherever incremental data transfer is reasonable. In a first feasibility study, we apply the proposed method to a dataset of ARGO drifting buoys covering large spatio-temporal regions of the world's oceans and compare the achieved compression ratio to other formats.

  4. Instability of induction cooker (electromagnetic stove) antigen retrieval in immunohistochemistry.

    PubMed

    Ding, Wei; Zheng, Xiang-Yi

    2012-03-01

    An induction cooker is a modern electric cooker that takes electromagnetic induction principle to heat. As it has high efficiency, no open flame, and is safe and convenient, more and more laboratories use it as an antigen retrieval heating tool in immunohistochemistry. We found that there was still some instability with the induction cooker, because with certain antigens the power change influenced the results of immunohistochemistry staining, showing weaker staining intensity or decreased number of positive cells, but which were not entirely negative. For some antigens, it had no influence on results. The instability of this heating tool for antigen retrieval was caused partly by negligent operators, and which may influence the experimental results and the pathologic diagnosis.

  5. Models for motion-based video indexing and retrieval.

    PubMed

    Dağtaş, S; Al-Khatib, W; Ghafoor, A; Kashyap, R L

    2000-01-01

    With the rapid proliferation of multimedia applications that require video data management, it is becoming more desirable to provide proper video data indexing techniques capable of representing the rich semantics in video data. In real-time applications, the need for efficient query processing is another reason for the use of such techniques. We present models that use the object motion information in order to characterize the events to allow subsequent retrieval. Algorithms for different spatiotemporal search cases in terms of spatial and temporal translation and scale invariance have been developed using various signal and image processing techniques. We have developed a prototype video search engine, PICTURESQUE (pictorial information and content transformation unified retrieval engine for spatiotemporal queries) to verify the proposed methods. Development of such technology will enable true multimedia search engines that will enable indexing and searching of the digital video data based on its true content. PMID:18255375

  6. Cross-modal retrieval of scripted speech audio

    NASA Astrophysics Data System (ADS)

    Owen, Charles B.; Makedon, Fillia

    1997-12-01

    This paper describes an approach to the problem of searching speech-based digital audio using cross-modal information retrieval. Audio containing speech (speech-based audio) is difficult to search. Open vocabulary speech recognition is advancing rapidly, but cannot yield high accuracy in either search or transcription modalities. However, text can be searched quickly and efficiently with high accuracy. Script- light digital audio is audio that has an available transcription. This is a surprisingly large class of content including legal testimony, broadcasting, dramatic productions and political meetings and speeches. An automatic mechanism for deriving the synchronization between the transcription and the audio allows for very accurate retrieval of segments of that audio. The mechanism described in this paper is based on building a transcription graph from the text and computing biphone probabilities for the audio. A modified beam search algorithm is presented to compute the alignment.

  7. Memory engram storage and retrieval.

    PubMed

    Tonegawa, Susumu; Pignatelli, Michele; Roy, Dheeraj S; Ryan, Tomás J

    2015-12-01

    A great deal of experimental investment is directed towards questions regarding the mechanisms of memory storage. Such studies have traditionally been restricted to investigation of the anatomical structures, physiological processes, and molecular pathways necessary for the capacity of memory storage, and have avoided the question of how individual memories are stored in the brain. Memory engram technology allows the labeling and subsequent manipulation of components of specific memory engrams in particular brain regions, and it has been established that cell ensembles labeled by this method are both sufficient and necessary for memory recall. Recent research has employed this technology to probe fundamental questions of memory consolidation, differentiating between mechanisms of memory retrieval from the true neurobiology of memory storage.

  8. Retrieving the ars moriendi tradition.

    PubMed

    Leget, Carlo

    2007-09-01

    North Atlantic culture lacks a commonly shared view on dying well that helps the dying, their social environment and caregivers to determine their place and role, interpret death and deal with the process of ethical deliberation. What is lacking nowadays, however, has been part of Western culture in medieval times and was known as the ars moriendi (art of dying well) tradition. In this paper an updated version of this tradition is presented that meets the demands of present day secularized and multiform society. Five themes are central to the new art of dying: autonomy and the self, pain control and medical intervention, attachment and relations, life balance and guilt, death and afterlife. The importance of retrieving the ancient ars moriendi outreaches the boundaries of palliative medicine, since it deals with issues that play a central role in every context of medical intervention and treatment.

  9. Trends in Research on Information Retrieval--The Potential for Improvements in Conventional Boolean Retrieval Systems.

    ERIC Educational Resources Information Center

    Radecki, Tadeusz

    1988-01-01

    Discusses the inability of the standard Boolean logic model of information retrieval to deal effectively with the inherent fallibility of retrieval decisions. Recent advances in information retrieval research are reviewed, and their practical potential for overcoming the deficiencies of the Boolean model is examined. (45 references) (Author/CLB)

  10. Content-based hyperspectral image retrieval using spectral unmixing

    NASA Astrophysics Data System (ADS)

    Plaza, Antonio J.

    2011-11-01

    The purpose of content-based image retrieval (CBIR) is to retrieve, from real data stored in a database, information that is relevant to a query. A major challenge for the development of efficient CBIR systems in the context of hyperspectral remote sensing applications is how to deal with the extremely large volumes of data produced by current Earth-observing (EO) imaging spectrometers. The data resulting from EO campaigns often comprises many Gigabytes per flight. When multiple instruments or timelines are combined, this leads to the collection of massive amounts of data coming from heterogeneous sources, and these data sets need to be effectively stored, managed, shared and retrieved. Furthermore, the growth in size and number of hyperspectral data archives demands more sophisticated search capabilities to allow users to locate and reuse data acquired in the past. In this paper we develop a new strategy to effectively retrieve hyperspectral image data sets using spectral unmixing concepts. Spectral unmixing is a very important task for hyperspectral data exploitation since the spectral signatures collected in natural environments are invariably a mixture of the pure signatures of the various materials found within the spatial extent of the ground instantaneous field view of the imaging instrument. In this work, we use the information provided by spectral unmixing (i.e. the spectral endmembers and their corresponding abundances in the scene) as effective meta-data to develop a new CBIR system that can assist users in the task of efficiently searching hyperspectral image instances in large data repositories. The proposed approach is validated using a collection of 154 hyperspectral data sets (comprising seven full flightlines) gathered by NASA using the Airborne Visible Infra-Red Imaging Spectrometer (AVIRIS) over the World Trade Center (WTC) area in New York City during the last two weeks of September, 2001, only a few days after the terrorist attacks that

  11. Functional-anatomic study of episodic retrieval using fMRI. I. Retrieval effort versus retrieval success.

    PubMed

    Buckner, R L; Koutstaal, W; Schacter, D L; Wagner, A D; Rosen, B R

    1998-04-01

    A number of recent functional imaging studies have identified brain areas activated during tasks involving episodic memory retrieval. The identification of such areas provides a foundation for targeted hypotheses regarding the more specific contributions that these areas make to episodic retrieval. As a beginning effort toward such an endeavor, whole-brain functional magnetic resonance imaging (fMRI) was used to examine 14 subjects during episodic word recognition in a block-designed fMRI experiment. Study conditions were manipulated by presenting either shallow or deep encoding tasks. This manipulation yielded two recognition conditions that differed with regard to retrieval effort and retrieval success: shallow encoding yielded low levels of recognition success with high levels of retrieval effort, and deep encoding yielded high levels of recognition success with low levels of effort. Many brain areas were activated in common by these two recognition conditions compared to a low-level fixation condition, including left and right prefrontal regions often detected during PET episodic retrieval paradigms (e.g., R. L. Buckner et al., 1996, J. Neurosci. 16, 6219-6235) thereby generalizing these findings to fMRI. Characterization of the activated regions in relation to the separate recognition conditions showed (1) bilateral anterior insular regions and a left dorsal prefrontal region were more active after shallow encoding, when retrieval demanded greatest effort, and (2) right anterior prefrontal cortex, which has been implicated in episodic retrieval, was most active during successful retrieval after deep encoding. We discuss these findings in relation to component processes involved in episodic retrieval and in the context of a companion study using event-related fMRI.

  12. Compressed sensing phase retrieval with phase diversity

    NASA Astrophysics Data System (ADS)

    Qin, Shun; Hu, Xinqi; Qin, Qiong

    2014-01-01

    The compressed sensing (CS) theory shows that sparse signal can be reconstructed accurately with some randomly observed measurements that are much fewer than what traditional method requires. Since it takes structure of signals into consideration, it has many advantages in the structured signals process. With CS, measuring can be speeded up and the cost of hardware can be decreased significantly. However, it faces great challenge in the amplitude-only measurement. In this article, we study the magnitude-only compressed sensing phase retrieval (CSPR) problem, and propose a practical recovery algorithm. In our algorithm, we introduce the powerful Hybrid-Input-Output algorithm with phase diversity to make our algorithm robust and efficient. A relaxed ℓ0 norm constrain is also introduced to help PR find a sparse solution with fewer measurements, which is demonstrated to be essential and effective to CSPR. We finally successfully apply it into complex-valued object recovery in THz imaging. The numerical results show that the proposed algorithm can recover the object pretty well with fewer measurements than what PR traditionally requires.

  13. Interactive layout mechanisms for image database retrieval

    SciTech Connect

    MacCuish, J.; McPherson, A.; Barros, J.; Kelly, P.

    1996-01-29

    In this paper we present a user interface, CANDID Camera, for image retrieval using query-by-example technology. Included in the interface are several new layout algorithms based on multidimensional scaling techniques that visually display global and local relationships between images within a large image database. We use the CANDID project algorithms to create signatures of the images, and then measure the dissimilarity between the signatures. The layout algorithms are of two types. The first are those that project the all-pairs dissimilarities to two dimensions, presenting a many-to-many relationship for a global view of the entire database. The second are those that relate a query image to a small set of matched images for a one-to-many relationship that provides a local inspection of the image relationships. Both types are based on well-known multidimensional scaling techniques that have been modified and used together for efficiency and effectiveness. They include nonlinear projection and classical projection. The global maps are hybrid algorithms using classical projection together with nonlinear projection. We have developed several one-to-many layouts based on a radial layout, also using modified nonlinear and classical projection.

  14. Interactive layout mechanisms for image database retrieval

    NASA Astrophysics Data System (ADS)

    MacCuish, John; McPherson, Allen; Barros, Julio E.; Kelly, Patrick M.

    1996-03-01

    In this paper we present a user interface, CANDID Camera, for image retrieval using query- by-example technology. Included in the interface are several new layout algorithms based on multidimensional scaling techniques that visually display global and local relationships between images within a large image database. We use the CANDID project algorithms to create signatures of the images, and then measure the dissimilarity between the signatures. The layout algorithms are of two types. The first are those that project the all-pairs dissimilarities to two dimensions, presenting a many-to-many relationship for a global view of the entire database. The second are those that relate a query image to a small set of matched images for a one-to-many relationship that provides a local inspection of the image relationships. Both types are based on well-known multidimensional scaling techniques that have been modified and used together for efficiency and effectiveness. They include nonlinear projection and classical projection. The global maps are hybrid algorithms using classical projection together with nonlinear projection. We have developed several one-to-many layouts based on a radial layout, also using modified nonlinear and classical projection.

  15. Unsuccessful Retrieval Attempts Enhance Subsequent Learning

    ERIC Educational Resources Information Center

    Kornell, Nate; Hays, Matthew Jensen; Bjork, Robert A.

    2009-01-01

    Taking tests enhances learning. But what happens when one cannot answer a test question--does an unsuccessful retrieval attempt impede future learning or enhance it? The authors examined this question using materials that ensured that retrieval attempts would be unsuccessful. In Experiments 1 and 2, participants were asked fictional…

  16. Retrieval during Learning Facilitates Subsequent Memory Encoding

    ERIC Educational Resources Information Center

    Pastotter, Bernhard; Schicker, Sabine; Niedernhuber, Julia; Bauml, Karl-Heinz T.

    2011-01-01

    In multiple-list learning, retrieval during learning has been suggested to improve recall of the single lists by enhancing list discrimination and, at test, reducing interference. Using electrophysiological, oscillatory measures of brain activity, we examined to what extent retrieval during learning facilitates list encoding. Subjects studied 5…

  17. Making Space: Automated Storage and Retrieval.

    ERIC Educational Resources Information Center

    Tanis, Norman; Ventuleth, Cindy

    1987-01-01

    Describes a pilot project in automated storage and retrieval of library materials which uses miniload cranes to retrieve bins of materials, and an interface with an online catalog that patrons use to request materials. Savings in space and money and potential problems with the system are discussed. (CLB)

  18. Expert Systems and Intelligent Information Retrieval.

    ERIC Educational Resources Information Center

    Brooks, H. M.

    1987-01-01

    Explores what an intelligent information retrieval system involves and why expert system techniques might interest system designers. Expert systems research is reviewed with emphasis on components, architecture, and computer interaction, and it is concluded that information retrieval is not an ideal problem domain for expert system application at…

  19. The State of Retrieval System Evaluation.

    ERIC Educational Resources Information Center

    Salton, Gerald

    1992-01-01

    The current state of information retrieval (IR) evaluation is reviewed with criticisms directed at the available test collections and the research and evaluation methodologies used, including precision and recall rates for online searches and laboratory tests not including real users. Automatic text retrieval systems are also discussed. (32…

  20. Indexing and Retrieval for the Web.

    ERIC Educational Resources Information Center

    Rasmussen, Edie M.

    2003-01-01

    Explores current research on indexing and ranking as retrieval functions of search engines on the Web. Highlights include measuring search engine stability; evaluation of Web indexing and retrieval; Web crawlers; hyperlinks for indexing and ranking; ranking for metasearch; document structure; citation indexing; relevance; query evaluation;…

  1. Memory Retrieval and Interference: Working Memory Issues

    ERIC Educational Resources Information Center

    Radvansky, Gabriel A.; Copeland, David E.

    2006-01-01

    Working memory capacity has been suggested as a factor that is involved in long-term memory retrieval, particularly when that retrieval involves a need to overcome some sort of interference (Bunting, Conway, & Heitz, 2004; Cantor & Engle, 1993). Previous work has suggested that working memory is related to the acquisition of information during…

  2. Information Retrieval beyond the Text Document.

    ERIC Educational Resources Information Center

    Rui, Yong; Ortega, Michael; Huang, Thomas S.; Mehrotra, Sharad

    1999-01-01

    Reports some of the progress made over the years toward exploring information beyond the text domain. Describes the Multimedia Analysis and Retrieval Systems (MARS), developed to increase access to non-textual information. Addresses the following aspects of MARS: (1) visual feature extraction; (2) retrieval models; (3) query reformulation…

  3. Fuzzy Set Theoretical Approach to Document Retrieval.

    ERIC Educational Resources Information Center

    Radecki, Tadeusz

    1979-01-01

    Presents a new method of document retrieval based on the fundamental operations of fuzzy set theory. Basic notions are introduced. Then the syntax and semantics of the proposed language for document retrieval is given, and an algorithm allocating documents to particular queries is described and its properties are discussed. (Author/CWM)

  4. Attentional Limits in Memory Retrieval--Revisited

    ERIC Educational Resources Information Center

    Green, Collin; Johnston, James C.; Ruthruff, Eric

    2011-01-01

    Carrier and Pashler (1995) concluded--based on locus-of-slack dual-task methodology--that memory retrieval was subject to a central bottleneck. However, this conclusion conflicts with evidence from other lines of research suggesting that memory retrieval proceeds autonomously, in parallel with many other mental processes. In the present…

  5. Retrieval from Memory: Vulnerable or Inviolable?

    ERIC Educational Resources Information Center

    Jones, Dylan M.; Marsh, John E.; Hughes, Robert W.

    2012-01-01

    We show that retrieval from semantic memory is vulnerable even to the mere presence of speech. Irrelevant speech impairs semantic fluency--namely, lexical retrieval cued by a semantic category name--but only if it is meaningful (forward speech compared to reversed speech or words compared to nonwords). Moreover, speech related semantically to the…

  6. Facilitating Internet-Scale Code Retrieval

    ERIC Educational Resources Information Center

    Bajracharya, Sushil Krishna

    2010-01-01

    Internet-Scale code retrieval deals with the representation, storage, and access of relevant source code from a large amount of source code available on the Internet. Internet-Scale code retrieval systems support common emerging practices among software developers related to finding and reusing source code. In this dissertation we focus on some…

  7. Enhanced Text Retrieval Using Natural Language Processing.

    ERIC Educational Resources Information Center

    Liddy, Elizabeth D.

    1998-01-01

    Defines natural language processing (NLP); describes the use of NLP in information retrieval (IR); provides seven levels of linguistic analysis: phonological, morphological, lexical, syntactic, semantic, discourse, and pragmatic. Discusses the commercial use of NLP in IR with the example of DR-LINK (Document Retrieval using LINguistic Knowledge)…

  8. Progress in Documentation: Pictorial Information Retrieval.

    ERIC Educational Resources Information Center

    Enser, P. G. B.

    1995-01-01

    Surveys theoretical and practical issues associated with pictorial information retrieval. Concentrating on still and moving pictorial forms of the visual image, this paper focuses on indexing pictorial material and discusses four models of pictorial information retrieval corresponding with permutations of the verbal and visual modes for the…

  9. Exploiting Multimodal Context in Image Retrieval.

    ERIC Educational Resources Information Center

    Srihari, Rohini K.; Zhang, Zhongfei

    1999-01-01

    Finding information on the Web without encountering numerous false positives poses a challenge to multimedia information retrieval systems (MMIR). This research focuses on improving precision and recall in an MMIR system by interactively combining text processing with image processing in both the indexing and retrieval phases. A picture search…

  10. Applications of Optical Technology: Information Retrieval.

    ERIC Educational Resources Information Center

    O'Connor, Mary Ann

    1991-01-01

    Discusses applications of optical technology, especially CD-ROMs, to information management needs. Information retrieval problems are discussed; design questions that concern the format of the data, indexing methods, and retrieval capabilities are presented; the need for updates is considered; access requirements are discussed; and the importance…

  11. Information Retrieval and the Philosophy of Language.

    ERIC Educational Resources Information Center

    Blair, David C.

    2003-01-01

    Provides an overview of some of the main ideas in the philosophy of language that have relevance to the issues of information retrieval, focusing on the description of the intellectual content. Highlights include retrieval problems; recall and precision; words and meanings; context; externalism and the philosophy of language; and scaffolding and…

  12. Chinese Information Retrieval: Using Characters or Words?

    ERIC Educational Resources Information Center

    Nie, Jian-Yun; Ren, Fuji

    1999-01-01

    Discussion of Chinese information retrieval proposes a relaxed segmentation process which extracts the longest words and also the short words implied. Experiments show that information retrieval based on this segmentation gives a slightly higher effectiveness than n-grams or bigrams, and requires less time and space for document and query…

  13. Employing Multiple Representations for Chinese Information Retrieval.

    ERIC Educational Resources Information Center

    Kwok, K. L.

    1999-01-01

    Discusses information retrieval in the Chinese language and describes three representation methods for texts: 1-gram or character, bigram, and short-word. Describes a study that investigated using more than one method simultaneously to improve retrieval effectiveness and considers word segmentation and costs. (Author/LRW)

  14. Strategic Retrieval in a Reality Monitoring Task

    ERIC Educational Resources Information Center

    Rosburg, Timm; Mecklinger, Axel; Johansson, Mikael

    2011-01-01

    Strategic recollection refers to control processes that allow the retrieval of information that is relevant for a specific situation. These processes can be studied in memory exclusion tasks, which require the retrieval of particular kinds of episodic information. In the current study, we investigated strategic recollection in reality monitoring…

  15. Representation of Legal Knowledge for Conceptual Retrieval.

    ERIC Educational Resources Information Center

    Cross, George R.; deBessonet, Cary G.

    1985-01-01

    Describes traditional legal information retrieval systems--Juris, Lexis, Westlaw--and several new rule-based, knowledge-based, legal knowledge reasoning, and analytical legal information systems--Waterman and Peterson's Legal Decisionmaking System, Hafner's Legal Information Retrieval System, McCarty's TAXMAN, and the deBessonet representation of…

  16. Storage and Retrieval of Structured Documents.

    ERIC Educational Resources Information Center

    Macleod, Ian A.

    1990-01-01

    Describes a conceptual model for bibliographic data called Maestro (Management Environment for Structured Text Retrieval and Organization) that is being developed both to support structured documents in databases, and to provide a query language to link information contained in these structures. Traditional text retrieval systems are discussed,…

  17. Single Shell Tank (SST) Retrieval Sequence FY 2000 Update

    SciTech Connect

    GARFIELD, J.S.

    2000-09-27

    This document describes the baseline single-shell tank (SST) waste retrieval sequence for the River Protection Project (RPP) updated for Fiscal Year 2000. The SST retrieval sequence identifies the proposed retrieval order (sequence), the tank selection and prioritization rationale, and planned retrieval dates for Hanford SSTs. In addition, the tank selection criteria and reference retrieval method for this sequence are discussed.

  18. Design and evaluation of a curve matching-based spine x-ray image retrieval system

    NASA Astrophysics Data System (ADS)

    Lee, D. J.; Antani, Sameer; Xu, Xiaoqian; Long, L. Rodney

    2005-04-01

    A spine x-ray image retrieval system has been developed for retrieving images based on the pathology information such as the osteophyte. Osteophyte shows only in particular regions on the vertebra. This means the contour information on the vertebra regions that are not of interest hinder the image retrieval relevance precision. Curve matching or partial shape matching (PSM) methods based on dynamic programming for matching shapes with variable number of points and with different data point distribution have been developed to detect the osteophyte with similar shapes. Based on the shape property of spines, corner guided dynamic programming (DP) is introduced as the new enhanced searching strategy which dramatically increases the processing efficiency of the traditional DP. Shape representation method using multiple open triangles is presented in this paper. Performance evaluation of corner-guided DP on this shape representation based on human relevance judgment is presented. This paper also presents the implementation and performance of the retrieval system. The retrieval system consists of a user friendly graphical user interface (GUI) which has been developed for testing. All the shape matching methods that have been developed have been integrated into the system for the user to choose during a retrieval process. The retrieval results are ranked from the most similar to the least similar and can be all viewed by the user.

  19. Age Differences in Strategy Shift: Retrieval Avoidance or General Shift Reluctance?

    PubMed Central

    Frank, David J.; Touron, Dayna R.; Hertzog, Christopher

    2013-01-01

    Previous studies of metacognitive age differences in skill acquisition strategies have relied exclusively on tasks with a processing shift from an algorithm to retrieval strategy. Older adults’ demonstrated reluctance to shift strategies in such tasks could reflect either a specific aversion to a memory retrieval strategy or a general, inertial resistance to strategy change. Haider and Frensch’s (1999) alphabet verification task (AVT) affords a non-retrieval-based strategy shift. Participants verify the continuation of alphabet strings such as D E F G [4] L, with the bracketed digit indicating a number of letters to be skipped. When all deviations are restricted to the letter-digit-letter portion, participants can speed their responses by selectively attend only to that part of the stimulus. We adapted the AVT to include conditions which promoted shift to a retrieval strategy, a selective attention strategy, or both strategies. Item-level strategy reports were validated by eye movement data. Older adults shifted more slowly to the retrieval strategy but more quickly to the selective attention strategy than young adults, indicating a retrieval-strategy avoidance. Strategy confidence and perceived strategy difficulty correlated with shift to the two strategies in both age groups. Perceived speed of responses with each strategy specifically correlated with older adults’ strategy choices, suggesting that some older adults avoid retrieval because they do not appreciate its efficiency benefits. PMID:23088195

  20. Comprehension of Linguistic Dependencies: Speed-Accuracy Tradeoff Evidence for Direct-Access Retrieval From Memory

    PubMed Central

    Foraker, Stephani; McElree, Brian

    2012-01-01

    Comprehenders can rapidly and efficiently interpret expressions with various types of non-adjacent dependencies. In the sentence The boy that the teacher warned fell, boy is readily interpreted as the subject of the verb fall despite the fact that a relative clause, that the teacher warned, intervenes between the two dependent elements. We review research investigating three memory operations proposed for resolving this and other types of non-adjacent dependencies: serial search retrieval, in which the dependent constituent is recovered by a search process through representations in memory, direct-access retrieval in which the dependent constituent is recovered directly by retrieval cue operations without search, and active maintenance of the dependent constituent in focal attention. Studies using speed-accuracy tradeoff methodology to examine the full timecourse of interpreting a wide range of non-adjacent dependencies indicate that comprehenders retrieve dependent constituents with a direct-access operation, consistent with the claim that representations formed during comprehension are accessed with a cue-driven, content-addressable retrieval process. The observed timecourse profiles are inconsistent with a broad class of models based on several search operations for retrieval. The profiles are also inconsistent with active maintenance of a constituent while concurrently processing subsequent material, and suggest that, with few exceptions, direct-access retrieval is required to process non-adjacent dependencies. PMID:22448181

  1. Compact binary hashing for music retrieval

    NASA Astrophysics Data System (ADS)

    Seo, Jin S.

    2014-03-01

    With the huge volume of music clips available for protection, browsing, and indexing, there is an increased attention to retrieve the information contents of the music archives. Music-similarity computation is an essential building block for browsing, retrieval, and indexing of digital music archives. In practice, as the number of songs available for searching and indexing is increased, so the storage cost in retrieval systems is becoming a serious problem. This paper deals with the storage problem by extending the supervector concept with the binary hashing. We utilize the similarity-preserving binary embedding in generating a hash code from the supervector of each music clip. Especially we compare the performance of the various binary hashing methods for music retrieval tasks on the widely-used genre dataset and the in-house singer dataset. Through the evaluation, we find an effective way of generating hash codes for music similarity estimation which improves the retrieval performance.

  2. Validation of MODIS Aerosol Retrieval Over Ocean

    NASA Technical Reports Server (NTRS)

    Remer, Lorraine A.; Tanre, Didier; Kaufman, Yoram J.; Ichoku, Charles; Mattoo, Shana; Levy, Robert; Chu, D. Allen; Holben, Brent N.; Dubovik, Oleg; Ahmad, Ziauddin; Einaudi, Franco (Technical Monitor)

    2001-01-01

    The MODerate resolution Imaging Spectroradiometer (MODIS) algorithm for determining aerosol characteristics over ocean is performing with remarkable accuracy. A two-month data set of MODIS retrievals co-located with observations from the AErosol RObotic NETwork (AERONET) ground-based sunphotometer network provides the necessary validation. Spectral radiation measured by MODIS (in the range 550 - 2100 nm) is used to retrieve the aerosol optical thickness, effective particle radius and ratio between the submicron and micron size particles. MODIS-retrieved aerosol optical thickness at 660 nm and 870 nm fall within the expected uncertainty, with the ensemble average at 660 nm differing by only 2% from the AERONET observations and having virtually no offset. MODIS retrievals of aerosol effective radius agree with AERONET retrievals to within +/- 0.10 micrometers, while MODIS-derived ratios between large and small mode aerosol show definite correlation with ratios derived from AERONET data.

  3. Memory retrieval and its lasting consequences.

    PubMed

    Izquierdo, Iván; Vianna, Mónica R.M.; Izquierdo, Luciana A.; Barros, Daniela M.; Szapiro, Germán; Coitinho, Adriana S.; Muller, Lionel; Cammarota, Martín; Bevilaqua, Lia R.M.; Medina, Jorge H.

    2002-01-01

    Many, if not all psychiatric diseases are accompanied by memory disturbances, in particular, the dementias, schizophrenia, and, to an extent, mood disorders. Anxiety and stress, on the other hand, cause important alterations of memory, particularly its retrieval. Here we discuss several new findings on the basic mechanisms of consolidation, retrieval and extinction of a prototype form of episodic memory in the rat: conditioned fear. The findings point the way for investigations on the pathology of these aspects of memory in health and disease. Emphasis is placed on the parallel processing of retrieval in several cortical areas, on the links between retrieval and the onset of extinction, on the fact that extinction involves new learning requiring gene expression, and on the differences between the retrieval of recent or remote long-term memories.

  4. Retrieval-practice task affects relationship between working memory capacity and retrieval-induced forgetting.

    PubMed

    Storm, Benjamin C; Bui, Dung C

    2016-11-01

    Retrieving a subset of items from memory can cause forgetting of other items in memory, a phenomenon referred to as retrieval-induced forgetting (RIF). Individuals who exhibit greater amounts of RIF have been shown to also exhibit superior working memory capacity (WMC) and faster stop-signal reaction times (SSRTs), results which have been interpreted as suggesting that RIF reflects an inhibitory process that is mediated by the processes of executive control. Across four experiments, we sought to further elucidate this issue by manipulating the way in which participants retrieved items during retrieval practice and examining how the resulting effects of forgetting correlated with WMC (Experiments 1-3) and SSRT (Experiment 4). Significant correlations were observed when participants retrieved items from an earlier study phase (within-list retrieval practice), but not when participants generated items from semantic memory (extra-list retrieval practice). These results provide important new insight into the role of executive-control processes in RIF.

  5. Retrieving clinically relevant diabetic retinopathy images using a multi-class multiple-instance framework

    NASA Astrophysics Data System (ADS)

    Chandakkar, Parag S.; Venkatesan, Ragav; Li, Baoxin

    2013-02-01

    Diabetic retinopathy (DR) is a vision-threatening complication from diabetes mellitus, a medical condition that is rising globally. Unfortunately, many patients are unaware of this complication because of absence of symptoms. Regular screening of DR is necessary to detect the condition for timely treatment. Content-based image retrieval, using archived and diagnosed fundus (retinal) camera DR images can improve screening efficiency of DR. This content-based image retrieval study focuses on two DR clinical findings, microaneurysm and neovascularization, which are clinical signs of non-proliferative and proliferative diabetic retinopathy. The authors propose a multi-class multiple-instance image retrieval framework which deploys a modified color correlogram and statistics of steerable Gaussian Filter responses, for retrieving clinically relevant images from a database of DR fundus image database.

  6. Layout-based substitution tree indexing and retrieval for mathematical expressions

    NASA Astrophysics Data System (ADS)

    Schellenberg, Thomas; Yuan, Bo; Zanibbi, Richard

    2012-01-01

    We introduce a new system for layout-based (LATEX) indexing and retrieval of mathematical expressions using substitution trees. Substitution trees can efficiently store and find expressions based on the similarity of their symbols, symbol layout, sub-expressions and size. We describe our novel implementation and some of our modifications to the substitution tree indexing and retrieval algorithms. We provide an experiment testing our system against the TF-IDF keyword-based system of Zanibbi and Yuan and demonstrate that, in many cases, the quality of search results returned by both systems is comparable (overall means, substitution tree vs. keywordbased: 100% vs. 89% for top 1; 48% vs. 51% for top 5; 22% vs. 28% for top 20). Overall, we present a promising first attempt at layout-based substitution tree indexing and retrieval for mathematical expressions and believe that this method will prove beneficial to the field of mathematical information retrieval.

  7. Efficient sampling of protein conformational space using fast loop building and batch minimization on highly parallel computers.

    PubMed

    Tyka, Michael D; Jung, Kenneth; Baker, David

    2012-12-01

    All-atom sampling is a critical and compute-intensive end stage to protein structural modeling. Because of the vast size and extreme ruggedness of conformational space, even close to the native structure, the high-resolution sampling problem is almost as difficult as predicting the rough fold of a protein. Here, we present a combination of new algorithms that considerably speed up the exploration of very rugged conformational landscapes and are capable of finding heretofore hidden low-energy states. The algorithm is based on a hierarchical workflow and can be parallelized on supercomputers with up to 128,000 compute cores with near perfect efficiency. Such scaling behavior is notable, as with Moore's law continuing only in the number of cores per chip, parallelizability is a critical property of new algorithms. Using the enhanced sampling power, we have uncovered previously invisible deficiencies in the Rosetta force field and created an extensive decoy training set for optimizing and testing force fields.

  8. Below the Surface: Analogical Similarity and Retrieval Competition in Reminding.

    ERIC Educational Resources Information Center

    Wharton, Charles M.; And Others

    1994-01-01

    Three experiments involving 222 undergraduates investigated whether and when human memory retrieval is influenced by structural consistency. In all experiments, retrieval competition was manipulated. Results indicate that both retrieval competition and structural consistency influence reminding. Implications for psychological and artificial…

  9. Spaced retrieval treatment of anomia

    PubMed Central

    Fridriksson, Julius; Holland, Audrey L.; Beeson, Pélagie; Morrow, Leigh

    2006-01-01

    Background Spaced Retrieval (SR) is a treatment approach developed to facilitate recall of information by individuals with dementia. Essentially an errorless learning procedure that can be used to facilitate recall of a variety of information, SR gradually increases the interval between correct recall of target items. Aims Given the success of using SR in dementia, the purpose of this study was to explore its usefulness in improving naming by individuals with aphasia. The rate of acquisition and retention of items was compared between SR and a more traditional treatment technique—cueing hierarchy (CH). Also, each oral naming treatment was run concurrently with a single word writing treatment. Methods & Procedures Three participants who had moderate or severe naming impairments and agraphia were studied. Single-subject design was applied across oral and written naming and treated and untreated items. Outcomes & Results The results indicate that for these participants, SR resulted in improved naming of specific items. The data further suggest that SR compared favourably to CH with regard to both acquisition and retention of items. The participants also benefited nicely from the writing treatment. Conclusions These findings suggest SR may be an alternative for managing naming impairment resulting from aphasia. Furthermore, the study supports providing treatments aimed at two different modalities concurrently. PMID:16823467

  10. Data storage and retrieval system

    NASA Technical Reports Server (NTRS)

    Nakamoto, Glen

    1992-01-01

    The Data Storage and Retrieval System (DSRS) consists of off-the-shelf system components integrated as a file server supporting very large files. These files are on the order of one gigabyte of data per file, although smaller files on the order of one megabyte can be accommodated as well. For instance, one gigabyte of data occupies approximately six 9-track tape reels (recorded at 6250 bpi). Due to this large volume of media, it was desirable to 'shrink' the size of the proposed media to a single portable cassette. In addition to large size, a key requirement was that the data needs to be transferred to a (VME based) workstation at very high data rates. One gigabyte (GB) of data needed to be transferred from an archiveable media on a file server to a workstation in less than 5 minutes. Equivalent size, on-line data needed to be transferred in less than 3 minutes. These requirements imply effective transfer rates on the order of four to eight megabytes per second (4-8 MB/s). The DSRS also needed to be able to send and receive data from a variety of other sources accessible from an Ethernet local area network.

  11. Retrieved Latent Heating from TRMM

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Smith, Eric A.; Houze Jr, Robert

    2008-01-01

    The global hydrological cycle is central to the Earth's climate system, with rainfall and the physics of precipitation formation acting as the key links in the cycle. Two-thirds of global rainfall occurs in the tropics with the associated latent heating (LH) accounting for three-fourths of the total heat energy available to the Earth's atmosphere. In addition, fresh water provided by tropical rainfall and its variability exerts a large impact upon the structure and motions of the upper ocean layer. In the last decade, it has been established that standard products of LH from satellite measurements, particularly TRMM measurements, would be a valuable resource for scientific research and applications. Such products would enable new insights and investigations concerning the complexities of convection system life cycles, the diabatic heating controls and feedbacks related to meso-synoptic circulations and their forecasting, the relationship of tropical patterns of LH to the global circulation and climate, and strategies for improving cloud parameterizations in environmental prediction models. The status of retrieved TRMM LH products, TRMM LH inter-comparison and validation project, current TRMM LH applications and critic issues/action items (based on previous five TRMM LH workshops) is presented in this article.

  12. The OMPS Limb Profiler Instrument: Two-Dimensional Retrieval Algorithm

    NASA Technical Reports Server (NTRS)

    Rault, Didier F.

    2010-01-01

    radiances within a non-uniform atmosphere and evaluate 2D analytical partial derivatives) and (2) an optimal estimator inversion routine. The algorithm uses the typically sparse nature of the kernel matrices as well as fast matrix inversion techniques to allow for fast inversion of limb data with efficient memory management (as was done for MIPAS data processing). While the method has so far only been developed in the context of Single Scatter, the paper will show how the CPU intensive Multiple Scatter modeling can be implemented using parallel CPU processing. Initial results will be presented in terms of retrieved ozone profiles and code performance.

  13. Fast large-scale object retrieval with binary quantization

    NASA Astrophysics Data System (ADS)

    Zhou, Shifu; Zeng, Dan; Shen, Wei; Zhang, Zhijiang; Tian, Qi

    2015-11-01

    The objective of large-scale object retrieval systems is to search for images that contain the target object in an image database. Where state-of-the-art approaches rely on global image representations to conduct searches, we consider many boxes per image as candidates to search locally in a picture. In this paper, a feature quantization algorithm called binary quantization is proposed. In binary quantization, a scale-invariant feature transform (SIFT) feature is quantized into a descriptive and discriminative bit-vector, which allows itself to adapt to the classic inverted file structure for box indexing. The inverted file, which stores the bit-vector and box ID where the SIFT feature is located inside, is compact and can be loaded into the main memory for efficient box indexing. We evaluate our approach on available object retrieval datasets. Experimental results demonstrate that the proposed approach is fast and achieves excellent search quality. Therefore, the proposed approach is an improvement over state-of-the-art approaches for object retrieval.

  14. Dielectric GaAs antenna ensuring an efficient broadband coupling between an InAs quantum dot and a Gaussian optical beam.

    PubMed

    Munsch, Mathieu; Malik, Nitin S; Dupuy, Emmanuel; Delga, Adrien; Bleuse, Joël; Gérard, Jean-Michel; Claudon, Julien; Gregersen, Niels; Mørk, Jesper

    2013-04-26

    We introduce the photonic trumpet, a dielectric structure which ensures a nearly perfect coupling between an embedded quantum light source and a Gaussian free-space beam. A photonic trumpet exploits both the broadband spontaneous emission control provided by a single-mode photonic wire and the expansion of this mode within a conical taper. Numerical simulations highlight the performance and robustness of this concept. As a first application in the field of quantum optics, we report the realization of an ultrabright single-photon source. The device, a high aspect ratio GaAs photonic trumpet containing a few InAs quantum dots, demonstrates a first-lens external efficiency of 0.75±0.1 and an external coupling efficiency to a Gaussian beam as high as 0.58±0.08. PMID:23679773

  15. Query Specific Rank Fusion for Image Retrieval.

    PubMed

    Zhang, Shaoting; Yang, Ming; Cour, Timothee; Yu, Kai; Metaxas, Dimitris N

    2015-04-01

    Recently two lines of image retrieval algorithms demonstrate excellent scalability: 1) local features indexed by a vocabulary tree, and 2) holistic features indexed by compact hashing codes. Although both of them are able to search visually similar images effectively, their retrieval precision may vary dramatically among queries. Therefore, combining these two types of methods is expected to further enhance the retrieval precision. However, the feature characteristics and the algorithmic procedures of these methods are dramatically different, which is very challenging for the feature-level fusion. This motivates us to investigate how to fuse the ordered retrieval sets, i.e., the ranks of images, given by multiple retrieval methods, to boost the retrieval precision without sacrificing their scalability. In this paper, we model retrieval ranks as graphs of candidate images and propose a graph-based query specific fusion approach, where multiple graphs are merged and reranked by conducting a link analysis on a fused graph. The retrieval quality of an individual method is measured on-the-fly by assessing the consistency of the top candidates' nearest neighborhoods. Hence, it is capable of adaptively integrating the strengths of the retrieval methods using local or holistic features for different query images. This proposed method does not need any supervision, has few parameters, and is easy to implement. Extensive and thorough experiments have been conducted on four public datasets, i.e., the UKbench, Corel-5K, Holidays and the large-scale San Francisco Landmarks datasets. Our proposed method has achieved very competitive performance, including state-of-the-art results on several data sets, e.g., the N-S score 3.83 for UKbench. PMID:26353295

  16. Iterative phase retrieval strategy of transient events.

    PubMed

    Ng, Tuck Wah; Chua, Adrian Sau Ling

    2012-01-20

    Important nuances of a process or processes in action can be obtained from the phase retrieval of diffraction patterns for analysis of transient events. A significant limitation associated with the iterative approach is that predictive input functions are needed and can result in situations of nonconvergence. In dealing with a transient event recorded as a series of Fourier magnitude patterns, such a hit-and-miss characteristic, on the surface, appears computationally daunting. We report and demonstrate a strategy here that effectively minimizes this by using a prior retrieved frame as the predictive function for the current retrieval process. PMID:22270666

  17. Solid waste retrieval. Phase 1, Operational basis

    SciTech Connect

    Johnson, D.M.

    1994-09-30

    This Document describes the operational requirements, procedures, and options for execution of the retrieval of the waste containers placed in buried storage in Burial Ground 218W-4C, Trench 04 as TRU waste or suspect TRU waste under the activity levels defining this waste in effect at the time of placement. Trench 04 in Burial Ground 218W-4C is totally dedicated to storage of retrievable TRU waste containers or retrievable suspect TRU waste containers and has not been used for any other purpose.

  18. Günter tulip filter retrieval experience: predictors of successful retrieval.

    PubMed

    Turba, Ulku Cenk; Arslan, Bulent; Meuse, Michael; Sabri, Saher; Macik, Barbara Gail; Hagspiel, Klaus D; Matsumoto, Alan H; Angle, John F

    2010-08-01

    We report our experience with Günter Tulip filter placement indications, retrievals, and procedural problems, with emphasis on alternative retrieval techniques. We have identified 92 consecutive patients in whom a Günter Tulip filter was placed and filter removal attempted. We recorded patient demographic information, filter placement and retrieval indications, procedures, standard and nonstandard filter retrieval techniques, complications, and clinical outcomes. The mean time to retrieval for those who experienced filter strut penetration was statistically significant [F(1,90) = 8.55, p = 0.004]. Filter strut(s) IVC penetration and successful retrieval were found to be statistically significant (p = 0.043). The filter hook-IVC relationship correlated with successful retrieval. A modified guidewire loop technique was applied in 8 of 10 cases where the hook appeared to penetrate the IVC wall and could not be engaged with a loop snare catheter, providing additional technical success in 6 of 8 (75%). Therefore, the total filter retrieval success increased from 88 to 95%. In conclusion, the Günter Tulip filter has high successful retrieval rates with low rates of complication. Additional maneuvers such as a guidewire loop method can be used to improve retrieval success rates when the filter hook is endothelialized.

  19. Information retrieval from black holes

    NASA Astrophysics Data System (ADS)

    Lochan, Kinjalk; Chakraborty, Sumanta; Padmanabhan, T.

    2016-08-01

    It is generally believed that, when matter collapses to form a black hole, the complete information about the initial state of the matter cannot be retrieved by future asymptotic observers, through local measurements. This is contrary to the expectation from a unitary evolution in quantum theory and leads to (a version of) the black hole information paradox. Classically, nothing else, apart from mass, charge, and angular momentum is expected to be revealed to such asymptotic observers after the formation of a black hole. Semiclassically, black holes evaporate after their formation through the Hawking radiation. The dominant part of the radiation is expected to be thermal and hence one cannot know anything about the initial data from the resultant radiation. However, there can be sources of distortions which make the radiation nonthermal. Although the distortions are not strong enough to make the evolution unitary, these distortions carry some part of information regarding the in-state. In this work, we show how one can decipher the information about the in-state of the field from these distortions. We show that the distortions of a particular kind—which we call nonvacuum distortions—can be used to fully reconstruct the initial data. The asymptotic observer can do this operationally by measuring certain well-defined observables of the quantum field at late times. We demonstrate that a general class of in-states encode all their information content in the correlation of late time out-going modes. Further, using a 1 +1 dimensional dilatonic black hole model to accommodate backreaction self-consistently, we show that observers can also infer and track the information content about the initial data, during the course of evaporation, unambiguously. Implications of such information extraction are discussed.

  20. Accelerated Adaptive MGS Phase Retrieval

    NASA Technical Reports Server (NTRS)

    Lam, Raymond K.; Ohara, Catherine M.; Green, Joseph J.; Bikkannavar, Siddarayappa A.; Basinger, Scott A.; Redding, David C.; Shi, Fang

    2011-01-01

    The Modified Gerchberg-Saxton (MGS) algorithm is an image-based wavefront-sensing method that can turn any science instrument focal plane into a wavefront sensor. MGS characterizes optical systems by estimating the wavefront errors in the exit pupil using only intensity images of a star or other point source of light. This innovative implementation of MGS significantly accelerates the MGS phase retrieval algorithm by using stream-processing hardware on conventional graphics cards. Stream processing is a relatively new, yet powerful, paradigm to allow parallel processing of certain applications that apply single instructions to multiple data (SIMD). These stream processors are designed specifically to support large-scale parallel computing on a single graphics chip. Computationally intensive algorithms, such as the Fast Fourier Transform (FFT), are particularly well suited for this computing environment. This high-speed version of MGS exploits commercially available hardware to accomplish the same objective in a fraction of the original time. The exploit involves performing matrix calculations in nVidia graphic cards. The graphical processor unit (GPU) is hardware that is specialized for computationally intensive, highly parallel computation. From the software perspective, a parallel programming model is used, called CUDA, to transparently scale multicore parallelism in hardware. This technology gives computationally intensive applications access to the processing power of the nVidia GPUs through a C/C++ programming interface. The AAMGS (Accelerated Adaptive MGS) software takes advantage of these advanced technologies, to accelerate the optical phase error characterization. With a single PC that contains four nVidia GTX-280 graphic cards, the new implementation can process four images simultaneously to produce a JWST (James Webb Space Telescope) wavefront measurement 60 times faster than the previous code.

  1. A similarity learning approach to content-based image retrieval: application to digital mammography.

    PubMed

    El-Naqa, Issam; Yang, Yongyi; Galatsanos, Nikolas P; Nishikawa, Robert M; Wernick, Miles N

    2004-10-01

    In this paper, we describe an approach to content-based retrieval of medical images from a database, and provide a preliminary demonstration of our approach as applied to retrieval of digital mammograms. Content-based image retrieval (CBIR) refers to the retrieval of images from a database using information derived from the images themselves, rather than solely from accompanying text indices. In the medical-imaging context, the ultimate aim of CBIR is to provide radiologists with a diagnostic aid in the form of a display of relevant past cases, along with proven pathology and other suitable information. CBIR may also be useful as a training tool for medical students and residents. The goal of information retrieval is to recall from a database information that is relevant to the user's query. The most challenging aspect of CBIR is the definition of relevance (similarity), which is used to guide the retrieval machine. In this paper, we pursue a new approach, in which similarity is learned from training examples provided by human observers. Specifically, we explore the use of neural networks and support vector machines to predict the user's notion of similarity. Within this framework we propose using a hierarchal learning approach, which consists of a cascade of a binary classifier and a regression module to optimize retrieval effectiveness and efficiency. We also explore how to incorporate online human interaction to achieve relevance feedback in this learning framework. Our experiments are based on a database consisting of 76 mammograms, all of which contain clustered microcalcifications (MCs). Our goal is to retrieve mammogram images containing similar MC clusters to that in a query. The performance of the retrieval system is evaluated using precision-recall curves computed using a cross-validation procedure. Our experimental results demonstrate that: 1) the learning framework can accurately predict the perceptual similarity reported by human observers, thereby

  2. EM-31 RETRIEVAL KNOWLEDGE CENTER MEETING REPORT: MOBILIZE AND DISLODGE TANK WASTE HEELS

    SciTech Connect

    Fellinger, A.

    2010-02-16

    The Retrieval Knowledge Center sponsored a meeting in June 2009 to review challenges and gaps to retrieval of tank waste heels. The facilitated meeting was held at the Savannah River Research Campus with personnel broadly representing tank waste retrieval knowledge at Hanford, Savannah River, Idaho, and Oak Ridge. This document captures the results of this meeting. In summary, it was agreed that the challenges to retrieval of tank waste heels fell into two broad categories: (1) mechanical heel waste retrieval methodologies and equipment and (2) understanding and manipulating the heel waste (physical, radiological, and chemical characteristics) to support retrieval options and subsequent processing. Recent successes and lessons from deployments of the Sand and Salt Mantis vehicles as well as retrieval of C-Area tanks at Hanford were reviewed. Suggestions to address existing retrieval approaches that utilize a limited set of tools and techniques are included in this report. The meeting found that there had been very little effort to improve or integrate the multiple proven or new techniques and tools available into a menu of available methods for rapid insertion into baselines. It is recommended that focused developmental efforts continue in the two areas underway (low-level mixing evaluation and pumping slurries with large solid materials) and that projects to demonstrate new/improved tools be launched to outfit tank farm operators with the needed tools to complete tank heel retrievals effectively and efficiently. This document describes the results of a meeting held on June 3, 2009 at the Savannah River Site in South Carolina to identify technology gaps and potential technology solutions to retrieving high-level waste (HLW) heels from waste tanks within the complex of sites run by the U. S. Department of Energy (DOE). The meeting brought together personnel with extensive tank waste retrieval knowledge from DOE's four major waste sites - Hanford, Savannah River

  3. Content-based vessel image retrieval

    NASA Astrophysics Data System (ADS)

    Mukherjee, Satabdi; Cohen, Samuel; Gertner, Izidor

    2016-05-01

    This paper describes an approach to vessel classification from satellite images using content based image retrieval methodology. Content-based image retrieval is an important problem in both medical imaging and surveillance applications. In many cases the archived reference database is not fully structured, thus making content-based image retrieval a challenging problem. In addition, in surveillance applications, the query image may be affected by weather or/and geometric distortions. Our approach of content-based vessel image retrieval consists of two phases. First, we create a structured reference database, then for each new query image of a vessel we find the closest cluster of images in the structured reference database, thus identifying and classifying the vessel. Then we update the closest cluster with new query image.

  4. Environmental impacts of proposed Monitored Retrievable Storage

    SciTech Connect

    Scharber, Wayne K.; Macintire, H. A.; Davis, Paul E.; Cothron, Terry K.; Stephens, Barry K.; Travis, Norman; Walter, George; Mobley, Mike

    1985-12-17

    This report describes environmental impacts from a proposed monitored retrievable storage facility for spent fuels to be located in Tennessee. Areas investigated include: water supply, ground water, air quality, solid waste management, and health hazards. (CBS)

  5. Improving case retrieval by remembering questions

    SciTech Connect

    Alterman, R.; Griffin, D.

    1996-12-31

    This paper discusses techniques that improve the performance of a case retrieval system, after it is deployed, as a result of the continued usage of the system, by remembering previous episodes of question answering. The user generates a request for information and the system responds with the retrieval of relevant case(s). A history of such transactional behavior over a given set of data is maintained by the system and used as a foundation for adapting its future retrieval behavior. With each transaction, the system acquires information about the usage of the system that is subsequently used to adjust the behavior of the system. This notion of a case retrieval system draws on a distinction between the system in isolation and the system as it is used for a particular set of cases. It also draws on distinctions between the designed system, the deployed system, and the system that emerges as it is used.

  6. Fuel Retrieval System (FRS) Design Verification

    SciTech Connect

    YANOCHKO, R.M.

    2000-01-27

    This document was prepared as part of an independent review to explain design verification activities already completed, and to define the remaining design verification actions for the Fuel Retrieval System. The Fuel Retrieval Subproject was established as part of the Spent Nuclear Fuel Project (SNF Project) to retrieve and repackage the SNF located in the K Basins. The Fuel Retrieval System (FRS) construction work is complete in the KW Basin, and start-up testing is underway Design modifications and construction planning are also underway for the KE Basin. An independent review of the design verification process as applied to the K Basin projects was initiated in support of preparation for the SNF Project operational readiness review (ORR).

  7. The JPL Library Information Retrieval System

    ERIC Educational Resources Information Center

    Walsh, Josephine

    1975-01-01

    The development, capabilities, and products of the computer-based retrieval system of the Jet Propulsion Laboratory Library are described. The system handles books and documents, produces a book catalog, and provides a machine search capability. (Author)

  8. Memory Retrieval in Mice and Men.

    PubMed

    Ben-Yakov, Aya; Dudai, Yadin; Mayford, Mark R

    2015-10-05

    Retrieval, the use of learned information, was until recently mostly terra incognita in the neurobiology of memory, owing to shortage of research methods with the spatiotemporal resolution required to identify and dissect fast reactivation or reconstruction of complex memories in the mammalian brain. The development of novel paradigms, model systems, and new tools in molecular genetics, electrophysiology, optogenetics, in situ microscopy, and functional imaging, have contributed markedly in recent years to our ability to investigate brain mechanisms of retrieval. We review selected developments in the study of explicit retrieval in the rodent and human brain. The picture that emerges is that retrieval involves coordinated fast interplay of sparse and distributed corticohippocampal and neocortical networks that may permit permutational binding of representational elements to yield specific representations. These representations are driven largely by the activity patterns shaped during encoding, but are malleable, subject to the influence of time and interaction of the existing memory with novel information.

  9. Information content of ozone retrieval algorithms

    NASA Technical Reports Server (NTRS)

    Rodgers, C.; Bhartia, P. K.; Chu, W. P.; Curran, R.; Deluisi, J.; Gille, J. C.; Hudson, R.; Mateer, C.; Rusch, D.; Thomas, R. J.

    1989-01-01

    The algorithms are characterized that were used for production processing by the major suppliers of ozone data to show quantitatively: how the retrieved profile is related to the actual profile (This characterizes the altitude range and vertical resolution of the data); the nature of systematic errors in the retrieved profiles, including their vertical structure and relation to uncertain instrumental parameters; how trends in the real ozone are reflected in trends in the retrieved ozone profile; and how trends in other quantities (both instrumental and atmospheric) might appear as trends in the ozone profile. No serious deficiencies were found in the algorithms used in generating the major available ozone data sets. As the measurements are all indirect in someway, and the retrieved profiles have different characteristics, data from different instruments are not directly comparable.

  10. Technical requirements specification for tank waste retrieval

    SciTech Connect

    Lamberd, D.L.

    1996-09-26

    This document provides the technical requirements specification for the retrieval of waste from the underground storage tanks at the Hanford Site. All activities covered by this scope are conducted in support of the Tank Waste Remediation System (TWRS) mission.

  11. HTI retrieval demonstration project execution plan

    SciTech Connect

    Ellingson, D.R.

    1997-09-04

    This plan describes the process for demonstrating the retrieval of difficult Hanford tank waste forms utilizing commercial technologies and the private sector to conduct the operations. The demonstration is to be conducted in Tank 241-C-106.

  12. Texture based feature extraction methods for content based medical image retrieval systems.

    PubMed

    Ergen, Burhan; Baykara, Muhammet

    2014-01-01

    The developments of content based image retrieval (CBIR) systems used for image archiving are continued and one of the important research topics. Although some studies have been presented general image achieving, proposed CBIR systems for archiving of medical images are not very efficient. In presented study, it is examined the retrieval efficiency rate of spatial methods used for feature extraction for medical image retrieval systems. The investigated algorithms in this study depend on gray level co-occurrence matrix (GLCM), gray level run length matrix (GLRLM), and Gabor wavelet accepted as spatial methods. In the experiments, the database is built including hundreds of medical images such as brain, lung, sinus, and bone. The results obtained in this study shows that queries based on statistics obtained from GLCM are satisfied. However, it is observed that Gabor Wavelet has been the most effective and accurate method. PMID:25227014

  13. Texture based feature extraction methods for content based medical image retrieval systems.

    PubMed

    Ergen, Burhan; Baykara, Muhammet

    2014-01-01

    The developments of content based image retrieval (CBIR) systems used for image archiving are continued and one of the important research topics. Although some studies have been presented general image achieving, proposed CBIR systems for archiving of medical images are not very efficient. In presented study, it is examined the retrieval efficiency rate of spatial methods used for feature extraction for medical image retrieval systems. The investigated algorithms in this study depend on gray level co-occurrence matrix (GLCM), gray level run length matrix (GLRLM), and Gabor wavelet accepted as spatial methods. In the experiments, the database is built including hundreds of medical images such as brain, lung, sinus, and bone. The results obtained in this study shows that queries based on statistics obtained from GLCM are satisfied. However, it is observed that Gabor Wavelet has been the most effective and accurate method.

  14. Symposium on Human-Computer Information Retrieval.

    PubMed

    Tunkelang, Daniel; Capra, Robert; Golovchinsky, Gene; Kules, Bill; Smith, Catherine; White, Ryen

    2013-03-01

    Human-computer information retrieval (HCIR) is the study of information retrieval techniques that integrate human intelligence and algorithmic search to help people explore, understand, and use information. Since 2007, we have held an annual gathering of researchers and practitioners to advance the state of the art in this field. This meeting report summarizes the history of the HCIR symposium and emphasizes its relevance to the data science community.

  15. Gunther Tulip Retrievable Inferior Vena Caval Filters: Indications, Efficacy, Retrieval, and Complications

    SciTech Connect

    Looby, S.; Given, M.F.; Geoghegan, T.; McErlean, A.; Lee, M.J.

    2007-02-15

    Purpose. We evaluated the Gunther Tulip (GT) retrievable inferior vena cava (IVC) filter with regard to indications, filtration efficacy, complications, retrieval window, and use of anticoagulation. Method. A retrospective study was performed of 147 patients (64 men, 83 women; mean age 58.8 years) who underwent retrievable GT filter insertion between 2001 and 2005. The indications for placement included a diagnosis of pulmonary embolism or deep venous thrombosis with a contraindication to anticoagulation (n = 68), pulmonary embolism or deep venous thrombosis while on anticoagulation (n = 49), prophylactic filter placement for high-risk surgical patients with a past history of pulmonary embolism or deep venous thrombosis (n = 20), and a high risk of pulmonary embolism or deep venous thrombosis (n = 10). Forty-nine of the 147 patients did not receive anticoagulation (33.7%) while 96 of 147 patients did, 82 of these receiving warfarin (56.5%), 11 receiving low-molecular weight heparins (7.58%), and 3 receiving antiplatelet agents alone (2.06%). Results. Filter placement was successful in 147 patients (100%). Two patients had two filters inserted. Of the 147 patients, filter deployment was on a permanent basis in 102 and with an intention to retrieve in 45 patients. There were 36 (80%) successful retrievals and 9 (20%) failed retrievals. The mean time to retrieval was 33.6 days. The reasons for failed retrieval included filter struts tightly adherent to the IVC wall (5/9), extreme filter tilt (2/9), and extensive filter thrombus (2/9). Complications included pneumothorax (n = 4), failure of filter expansion (n = 1), and breakthrough pulmonary embolism (n = 1). No IVC thrombotic episodes were recorded. Discussion. The Gunther Tulip retrievable filter can be used as a permanent or a retrievable filter. It is safe and efficacious. GT filters can be safely retrieved at a mean time interval of 33.6 days. The newly developed Celect filter may extend the retrieval interval.

  16. Retrieval opportunities while multitasking improve name recall.

    PubMed

    Helder, Elizabeth; Shaughnessy, John J

    2008-11-01

    In two experiments we tested whether providing retrieval opportunities while people were multitasking would improve memory for names. College students (n=195) in Experiment 1 did addition problems and intermittently were "introduced" to 12 face-name pairs to learn. For half the names students were given three within-list retrieval opportunities. Name recall (cued with the faces) was tested either immediately or after 24 hours. Retrieval opportunities improved name recall with both immediate and delayed tests. Experiment 2 more closely resembled the multitasking required in a real-life social situation. College students (n=98) viewed a videotape and were asked to learn the names of 12 dormitory residents who were introduced during an ongoing conversation. Retrieval opportunities were provided for 8 of the 12 residents by having them appear three additional times in the video without repeating their names. Retrieval opportunities improved name recall, but the effect was much smaller than in Experiment 1. The present research demonstrates that distributed retrieval can be effective when people are multitasking including when the multitasking involves a conversation.

  17. Working memory retrieval as a decision process

    PubMed Central

    Pearson, Benjamin; Raškevičius, Julius; Bays, Paul M.; Pertzov, Yoni; Husain, Masud

    2014-01-01

    Working memory (WM) is a core cognitive process fundamental to human behavior, yet the mechanisms underlying it remain highly controversial. Here we provide a new framework for understanding retrieval of information from WM, conceptualizing it as a decision based on the quality of internal evidence. Recent findings have demonstrated that precision of WM decreases with memory load. If WM retrieval uses a decision process that depends on memory quality, systematic changes in response time distribution should occur as a function of WM precision. We asked participants to view sample arrays and, after a delay, report the direction of change in location or orientation of a probe. As WM precision deteriorated with increasing memory load, retrieval time increased systematically. Crucially, the shape of reaction time distributions was consistent with a linear accumulator decision process. Varying either task relevance of items or maintenance duration influenced memory precision, with corresponding shifts in retrieval time. These results provide strong support for a decision-making account of WM retrieval based on noisy storage of items. Furthermore, they show that encoding, maintenance, and retrieval in WM need not be considered as separate processes, but may instead be conceptually unified as operations on the same noise-limited, neural representation. PMID:24492597

  18. Easily retrievable objects among the NEO population

    NASA Astrophysics Data System (ADS)

    García Yárnoz, D.; Sanchez, J. P.; McInnes, C. R.

    2013-08-01

    Asteroids and comets are of strategic importance for science in an effort to understand the formation, evolution and composition of the Solar System. Near-Earth Objects (NEOs) are of particular interest because of their accessibility from Earth, but also because of their speculated wealth of material resources. The exploitation of these resources has long been discussed as a means to lower the cost of future space endeavours. In this paper, we consider the currently known NEO population and define a family of so-called Easily Retrievable Objects (EROs), objects that can be transported from accessible heliocentric orbits into the Earth's neighbourhood at affordable costs. The asteroid retrieval transfers are sought from the continuum of low energy transfers enabled by the dynamics of invariant manifolds; specifically, the retrieval transfers target planar, vertical Lyapunov and halo orbit families associated with the collinear equilibrium points of the Sun-Earth Circular Restricted Three Body problem. The judicious use of these dynamical features provides the best opportunity to find extremely low energy Earth transfers for asteroid material. A catalogue of asteroid retrieval candidates is then presented. Despite the highly incomplete census of very small asteroids, the ERO catalogue can already be populated with 12 different objects retrievable with less than 500 m/s of Δ v. Moreover, the approach proposed represents a robust search and ranking methodology for future retrieval candidates that can be automatically applied to the growing survey of NEOs.

  19. Operant conditioning of autobiographical memory retrieval.

    PubMed

    Debeer, Elise; Raes, Filip; Williams, J Mark G; Craeynest, Miet; Hermans, Dirk

    2014-01-01

    Functional avoidance is considered as one of the key mechanisms underlying overgeneral autobiographical memory (OGM). According to this view OGM is regarded as a learned cognitive avoidance strategy, based on principles of operant conditioning; i.e., individuals learn to avoid the emotionally painful consequences associated with the retrieval of specific negative memories. The aim of the present study was to test one of the basic assumptions of the functional avoidance account, namely that autobiographical memory retrieval can be brought under operant control. Here 41 students were instructed to retrieve personal memories in response to 60 emotional cue words. Depending on the condition, they were punished with an aversive sound for the retrieval of specific or nonspecific memories in an operant conditioning procedure. Analyzes showed that the course of memory specificity significantly differed between conditions. After the procedure participants punished for nonspecific memories retrieved significantly more specific memories compared to participants punished for specific memories. However, whereas memory specificity significantly increased in participants punished for specific memories, it did not significantly decrease in participants punished for nonspecific memories. Thus, while our findings indicate that autobiographical memory retrieval can be brought under operant control, they do not support a functional avoidance view on OGM.

  20. Activities of information retrieval in Daicel Corporation : The roles and efforts of information retrieval team

    NASA Astrophysics Data System (ADS)

    Yamazaki, Towako

    In order to stabilize and improve quality of information retrieval service, the information retrieval team of Daicel Corporation has given some efforts on standard operating procedures, interview sheet for information retrieval, structured format for search report, and search expressions for some technological fields of Daicel. These activities and efforts will also lead to skill sharing and skill tradition between searchers. In addition, skill improvements are needed not only for a searcher individually, but also for the information retrieval team totally when playing searcher's new roles.

  1. Retrieval-Based Learning: Positive Effects of Retrieval Practice in Elementary School Children.

    PubMed

    Karpicke, Jeffrey D; Blunt, Janell R; Smith, Megan A

    2016-01-01

    A wealth of research has demonstrated that practicing retrieval is a powerful way to enhance learning. However, nearly all prior research has examined retrieval practice with college students. Little is known about retrieval practice in children, and even less is known about possible individual differences in retrieval practice. In three experiments, 88 children (mean age 10 years) studied a list of words and either restudied the items or practiced retrieving them. They then took a final free recall test (Experiments 1 and 2) or recognition test (Experiment 3). In all experiments, children showed robust retrieval practice effects. Although a range of individual differences in reading comprehension and processing speed were observed among these children, the benefits of retrieval practice were independent of these factors. The results contribute to the growing body of research supporting the mnemonic benefits of retrieval practice and provide preliminary evidence that practicing retrieval may be an effective learning strategy for children with varying levels of reading comprehension and processing speed. PMID:27014156

  2. Retrieval-Based Learning: Positive Effects of Retrieval Practice in Elementary School Children

    PubMed Central

    Karpicke, Jeffrey D.; Blunt, Janell R.; Smith, Megan A.

    2016-01-01

    A wealth of research has demonstrated that practicing retrieval is a powerful way to enhance learning. However, nearly all prior research has examined retrieval practice with college students. Little is known about retrieval practice in children, and even less is known about possible individual differences in retrieval practice. In three experiments, 88 children (mean age 10 years) studied a list of words and either restudied the items or practiced retrieving them. They then took a final free recall test (Experiments 1 and 2) or recognition test (Experiment 3). In all experiments, children showed robust retrieval practice effects. Although a range of individual differences in reading comprehension and processing speed were observed among these children, the benefits of retrieval practice were independent of these factors. The results contribute to the growing body of research supporting the mnemonic benefits of retrieval practice and provide preliminary evidence that practicing retrieval may be an effective learning strategy for children with varying levels of reading comprehension and processing speed. PMID:27014156

  3. Diffused holographic information storage and retrieval using photorefractive optical materials

    NASA Astrophysics Data System (ADS)

    McMillen, Deanna Kay

    Holography offers a tremendous opportunity for dense information storage, theoretically one bit per cubic wavelength of material volume, with rapid retrieval, of up to thousands of pages of information simultaneously. However, many factors prevent the theoretical storage limit from being reached, including dynamic range problems and imperfections in recording materials. This research explores new ways of moving closer to practical holographic information storage and retrieval by altering the recording materials, in this case, photorefractive crystals, and by increasing the current storage capacity while improving the information retrieved. As an experimental example of the techniques developed, the information retrieved is the correlation peak from an optical recognition architecture, but the materials and methods developed are applicable to many other holographic information storage systems. Optical correlators can potentially solve any signal or image recognition problem. Military surveillance, fingerprint identification for law enforcement or employee identification, and video games are but a few examples of applications. A major obstacle keeping optical correlators from being universally accepted is the lack of a high quality, thick (high capacity) holographic recording material that operates with red or infrared wavelengths which are available from inexpensive diode lasers. This research addresses the problems from two positions: find a better material for use with diode lasers, and reduce the requirements placed on the material while maintaining an efficient and effective system. This research found that the solutions are new dopants introduced into photorefractive lithium niobate to improve wavelength sensitivities and the use of a novel inexpensive diffuser that reduces the dynamic range and optical element quality requirements (which reduces the cost) while improving performance. A uniquely doped set of 12 lithium niobate crystals was specified and

  4. Integrating pretreatment and retrieval: Results from the July 1997 Tanks Focus Area workshop

    SciTech Connect

    1998-07-01

    If scientists and researchers working to solve the tank waste challenges, technical program office managers at the tank sites, and others understand the connection between retrieval and pretreatment activities, more efficient processes and reduced costs can be achieved. To make this possible, researchers involved in retrieval and pretreatment activities met at the Conference Center in Richland, Washington, on July 16 and 17, 1997, to discuss the connections between these activities. The purpose of the workshop was to help participants (1) gain a better understanding of retrieval and pretreatment process needs and experiences; (2) gain practical knowledge of the applications, capabilities, and requirements of retrieval and pretreatment technologies being developed and deployed; and (3) focus on identifying and troubleshooting interface issues and problems. The end product of this meeting was to create a checklist of retrieval and pretreatment parameters to consider when developing new technologies or managing work at the sites in these areas. For convenience, the information is also organized by pretreatment parameter and retrieval-pretreatment parameter in Section 5.0.

  5. Deeply learnt hashing forests for content based image retrieval in prostate MR images

    NASA Astrophysics Data System (ADS)

    Shah, Amit; Conjeti, Sailesh; Navab, Nassir; Katouzian, Amin

    2016-03-01

    Deluge in the size and heterogeneity of medical image databases necessitates the need for content based retrieval systems for their efficient organization. In this paper, we propose such a system to retrieve prostate MR images which share similarities in appearance and content with a query image. We introduce deeply learnt hashing forests (DL-HF) for this image retrieval task. DL-HF effectively leverages the semantic descriptiveness of deep learnt Convolutional Neural Networks. This is used in conjunction with hashing forests which are unsupervised random forests. DL-HF hierarchically parses the deep-learnt feature space to encode subspaces with compact binary code words. We propose a similarity preserving feature descriptor called Parts Histogram which is derived from DL-HF. Correlation defined on this descriptor is used as a similarity metric for retrieval from the database. Validations on publicly available multi-center prostate MR image database established the validity of the proposed approach. The proposed method is fully-automated without any user-interaction and is not dependent on any external image standardization like image normalization and registration. This image retrieval method is generalizable and is well-suited for retrieval in heterogeneous databases other imaging modalities and anatomies.

  6. Cluster-Based Query Expansion Using Language Modeling for Biomedical Literature Retrieval

    ERIC Educational Resources Information Center

    Xu, Xuheng

    2011-01-01

    The tremendously huge volume of biomedical literature, scientists' specific information needs, long terms of multiples words, and fundamental problems of synonym and polysemy have been challenging issues facing the biomedical information retrieval community researchers. Search engines have significantly improved the efficiency and effectiveness of…

  7. The Design of Document Retrieval Systems for Academic Users: Implications of Students on Users' Relevance Criteria.

    ERIC Educational Resources Information Center

    Wang, Peiling

    1997-01-01

    Proposes principles for the design of effective document retrieval (DR) systems incorporating users' cognitive behaviors. Addresses three issues: (1) effective representations for documents to enable users' relevance judgments and decision making; (2) efficient presentations of documents to facilitate users' information processing and decision…

  8. Motion feature extraction scheme for content-based video retrieval

    NASA Astrophysics Data System (ADS)

    Wu, Chuan; He, Yuwen; Zhao, Li; Zhong, Yuzhuo

    2001-12-01

    This paper proposes the extraction scheme of global motion and object trajectory in a video shot for content-based video retrieval. Motion is the key feature representing temporal information of videos. And it is more objective and consistent compared to other features such as color, texture, etc. Efficient motion feature extraction is an important step for content-based video retrieval. Some approaches have been taken to extract camera motion and motion activity in video sequences. When dealing with the problem of object tracking, algorithms are always proposed on the basis of known object region in the frames. In this paper, a whole picture of the motion information in the video shot has been achieved through analyzing motion of background and foreground respectively and automatically. 6-parameter affine model is utilized as the motion model of background motion, and a fast and robust global motion estimation algorithm is developed to estimate the parameters of the motion model. The object region is obtained by means of global motion compensation between two consecutive frames. Then the center of object region is calculated and tracked to get the object motion trajectory in the video sequence. Global motion and object trajectory are described with MPEG-7 parametric motion and motion trajectory descriptors and valid similar measures are defined for the two descriptors. Experimental results indicate that our proposed scheme is reliable and efficient.

  9. USB: ultrashort binary descriptor for fast visual matching and retrieval.

    PubMed

    Zhang, Shiliang; Tian, Qi; Huang, Qingming; Gao, Wen; Rui, Yong

    2014-08-01

    Currently, many local descriptors have been proposed to tackle a basic issue in computer vision: duplicate visual content matching. These descriptors either are represented as high-dimensional vectors relatively expensive to extract and compare or are binary codes limited in robustness. Bag-of-visual words (BoWs) model compresses local features into a compact representation that allows for fast matching and scalable indexing. However, the codebook training, high-dimensional feature extraction, and quantization significantly degrade the flexibility and efficiency of BoWs model. In this paper, we study an alternative to current local descriptors and BoWs model by extracting the ultrashort binary descriptor (USB) and a compact auxiliary spatial feature from each keypoint detected in images. A typical USB is a 24-bit binary descriptor, hence it directly quantizes visual clues of image keypoints to about 16 million unique IDs. USB allows fast image matching and indexing and avoids the expensive codebook training and feature quantization in BoWs model. The spatial feature complementarily captures the spatial configuration in neighbor region of each keypoint, hence is used to filter mismatched USBs in a cascade verification. In image matching task, USB shows promising accuracy and nearly one-order faster speed than SIFT. We also test USB in retrieval tasks on UKbench, Oxford5K, and 1.2 million distractor images. Comparisons with recent retrieval methods manifest the competitive accuracy, memory consumption, and significantly better efficiency of our approach.

  10. Content-based retrieval in videos from laparoscopic surgery

    NASA Astrophysics Data System (ADS)

    Schoeffmann, Klaus; Beecks, Christian; Lux, Mathias; Uysal, Merih Seran; Seidl, Thomas

    2016-03-01

    In the field of medical endoscopy more and more surgeons are changing over to record and store videos of their endoscopic procedures for long-term archival. These endoscopic videos are a good source of information for explanations to patients and follow-up operations. As the endoscope is the "eye of the surgeon", the video shows the same information the surgeon has seen during the operation, and can describe the situation inside the patient much more precisely than an operation report would do. Recorded endoscopic videos can also be used for training young surgeons and in some countries the long-term archival of video recordings from endoscopic procedures is even enforced by law. A major challenge, however, is to efficiently access these very large video archives for later purposes. One problem, for example, is to locate specific images in the videos that show important situations, which are additionally captured as static images during the procedure. This work addresses this problem and focuses on contentbased video retrieval in data from laparoscopic surgery. We propose to use feature signatures, which can appropriately and concisely describe the content of laparoscopic images, and show that by using this content descriptor with an appropriate metric, we are able to efficiently perform content-based retrieval in laparoscopic videos. In a dataset with 600 captured static images from 33 hours recordings, we are able to find the correct video segment for more than 88% of these images.

  11. The Use of Semantic Links in Hypertext Information Retrieval.

    ERIC Educational Resources Information Center

    Frei, H. P.; Stieger, D.

    1995-01-01

    Highlights semantic links and shows how the semantic content of hypertext links can be used for information retrieval. Discussion includes indexing and retrieval algorithms that exploit link content and node content; retrieval strategies exploiting semantic links, including conventional retrieval and constrained spreading activation techniques;…

  12. A Learning Scheme for Information Retrieval in Hypertext.

    ERIC Educational Resources Information Center

    Savoy, Jacques

    1994-01-01

    Proposes a new learning algorithm to improve the retrieval effectiveness of the search system used in the hypertext environment using an extended Boolean model with links to improve the ranking of retrieved items. Highlights include the basic retrieval scheme, the learning scheme, and a review of basic probabilistic retrieval models. (Contains 32…

  13. Transuranic (TRU) Waste Phase I Retrieval Plan

    SciTech Connect

    MCDONALD, K.M.

    2000-09-28

    From 1970 to 1987, TRU and suspect TRU wastes at Hanford were placed in the SWBG. At the time of placement in the SWBG these wastes were not regulated under existing Resource Conservation and Recovery Act (RCRA) regulations, since they were generated and disposed of prior to the effective date of RCRA at the Hanford Site (1987). From the standpoint of DOE Order 5820.2A1, the TRU wastes are considered retrievably stored, and current plans are to retrieve these wastes for shipment to WIPP for disposal. This plan provides a strategy for the Phase I retrieval that meets the intent of TPA milestone M-91 and Project W-113, and incorporates the lessons learned during TRU retrieval campaigns at Hanford, LANL, and SRS. As in the original Project W-113 plans, the current plan calls for examination of approximately 10,000 suspect-TRU drums located in the 218-W-4C burial ground followed by the retrieval of those drums verified to contain TRU waste. Unlike the older plan, however, this plan proposes an open-air retrieval scenario similar to those used for TRU drum retrieval at LANL and SRS. Phase I retrieval consists of the activities associated with the assessment of approximately 10,000 55-gallon drums of suspect TRU-waste in burial ground 218-W-4C and the retrieval of those drums verified to contain TRU waste. Four of the trenches in 218-W-4C (Trenches 1, 4, 20, and 29) are prime candidates for Phase I retrieval because they contain large numbers of suspect TRU drums, stacked from 2 to 5 drums high, on an asphalt pad. In fact, three of the trenches (Trenches 1 , 20, and 29) contain waste that has not been covered with soil, and about 1500 drums can be retrieved without excavation. The other three trenches in 218-W-4C (Trenches 7, 19, and 24) are not candidates for Phase I retrieval because they contain significant numbers of boxes. Drums will be retrieved from the four candidate trenches, checked for structural integrity, overpacked, if necessary, and assayed at the burial

  14. Retrieval of spheroidal particle size distribution using the approximate method in spectral extinction technique

    NASA Astrophysics Data System (ADS)

    Wang, Li; Sun, Xiaogang; Xing, Jian

    2012-04-01

    Retrieval of spheroidal particle size distribution using an approximate method in spectral extinction technique is proposed. The combined approximate method, which is the combination of Mie method and generalized eikonal approximation (GEA) method, is used as an alternative to the rigorous solutions to calculate the averaging extinction efficiency of spheroid. Based on the averaging extinction efficiency, the accuracy and limitations of the retrieval are then investigated. Moreover, the validity range and effect of the refractive index are also examined. The Johnson's SB function in this paper is used as a versatile function to fit the commonly used particle size distribution functions in the dependent model. Simulations and experimental results show that the combined approximate method can be successfully applied to retrieval of spheroidal particle size distribution. In certain constraint conditions, the retrieval results demonstrate the high reliability and stability of the method. By using the combined approximate method, the complexity and computation time of the retrieval are significantly reduced, which is more suitable for quick and easy measurement. The method can also be used as a replacement when the rigorous solutions suffer computationally intractable difficulties.

  15. X-linked intellectual disability-associated mutations in synaptophysin disrupt synaptobrevin II retrieval.

    PubMed

    Gordon, Sarah L; Cousin, Michael A

    2013-08-21

    Synaptophysin is an integral synaptic vesicle (SV) protein that accounts for ∼10% of total SV protein cargo. Deletion of synaptophysin results in the defective retrieval of synaptobrevin II (sybII) from the plasma membrane during endocytosis, coupled with a slowing in the speed of endocytosis. Synaptophysin has been implicated in X-linked intellectual disability, with a recent study identifying four separate synaptophysin gene mutations in families affected by the disorder. To determine how these mutations may affect synaptophysin function, we expressed them in cultured neurons derived from synaptophysin knock-out mice. Two distinct truncating mutants were mislocalized throughout the axon and phenocopied the arrest of sybII retrieval in synaptophysin knock-out cultures. The remaining two mutants displayed a nerve terminal localization but did not support efficient sybII retrieval. Interestingly, one mutant fully rescued SV endocytosis kinetics, suggesting that sybII retrieval and endocytosis speed are independent from each other. These studies suggest that the efficient retrieval of sybII by synaptophysin may be key to maintaining synaptic health and perturbation of this event may contribute to the pathogenesis underlying neurodevelopmental disorders such as X-linked intellectual disability.

  16. Alternate retrieval technology demonstrations program - test report (ARD Environmental, Inc.)

    SciTech Connect

    Berglin, E.J.

    1997-07-31

    on the tether, even if the vehicle wheels were locked or the vehicle was on its side. Line pull required to retrieve the vehicle was measured, and side load on the riser calculated from the line pull and line angles. Finally, the decontamination test demonstrated the ability to effectively clean the umbilical and vehicle. The issues addressed and resolved during the testing were: Feasibility of deploying a vehicle- based system, mobility, production rate and limitation of water in the tank during sluicing, mining strategy, operator efficiency, vehicle recovery, and decontamination. Water usage and waste removal rates were used to estimate the time and water usage requirements for cleaning a Hanford SST.

  17. Strategic retrieval in a reality monitoring task.

    PubMed

    Rosburg, Timm; Mecklinger, Axel; Johansson, Mikael

    2011-08-01

    Strategic recollection refers to control processes that allow the retrieval of information that is relevant for a specific situation. These processes can be studied in memory exclusion tasks, which require the retrieval of particular kinds of episodic information. In the current study, we investigated strategic recollection in reality monitoring by event-related potentials (ERPs). Participants studied object words, followed by a picture of the denoted object (perceive condition) or followed by the instruction to imagine such a picture (imagine condition). At test, subjects had to identify words of one study condition and to reject words of the second study condition together with newly presented items. Data analysis showed that object names were better identified when items of the perceive condition were targeted. In this test condition, a left parietal old/new effect (the ERP correlate of recollection) was observed only in response to targets. In contrast, both targets and nontargets elicited this old/new effect when items of the imagine condition were targeted. The magnitude of the left parietal old/new effect to nontargets in this condition (but no other left parietal old/new effect) correlated positively with the discrimination indices of both test conditions. In addition, ERPs to targets and nontargets differed at right frontal electrode sites at longer latencies (1500-1800 ms), with more positive ERPs for targets. Findings indicate that subjects retrieved nontarget information in the more difficult task condition, while they relied on target information alone in the less difficult task. This kind of strategic retrieval was not mirrored in other old/new effects. The correlation between the left parietal old/new effect for nontargets in the imagined item target condition and the discrimination indices of both conditions may indicate that the ease of nontarget retrieval, rather than the difficulty of target retrieval, increases the likelihood that nontarget

  18. TOFIR: A Tool of Facilitating Information Retrieval - Introduce a Visual Retrieval Model.

    ERIC Educational Resources Information Center

    Zhang, Jin

    2001-01-01

    Introduces a new method for the visualization of information retrieval called TOFIR (Tool of Facilitating Information Retrieval). Discusses the use of angle attributes of a document to construct the angle-based visual space; two-dimensional and three-dimensional visual tools; ambiguity; and future research directions. (Author/LRW)

  19. Challenging Conventional Assumptions of Automated Information Retrieval with Real Users: Boolean Searching and Batch Retrieval Evaluations.

    ERIC Educational Resources Information Center

    Hersh, William; Turpin, Andrew; Price, Susan; Kraemer, Dale; Olson, Daniel; Chan, Benjamin; Sacherek, Lynetta

    2001-01-01

    Describes research conducted at the TREC (Text Retrieval Conference) interactive track that compared Boolean and natural language searching, showing they achieved comparable results; and assessed the validity of batch-oriented retrieval evaluations, showing that the results from batch evaluations were not comparable to those obtained in…

  20. System engineering approach to GPM retrieval algorithms

    SciTech Connect

    Rose, C. R.; Chandrasekar, V.

    2004-01-01

    System engineering principles and methods are very useful in large-scale complex systems for developing the engineering requirements from end-user needs. Integrating research into system engineering is a challenging task. The proposed Global Precipitation Mission (GPM) satellite will use a dual-wavelength precipitation radar to measure and map global precipitation with unprecedented accuracy, resolution and areal coverage. The satellite vehicle, precipitation radars, retrieval algorithms, and ground validation (GV) functions are all critical subsystems of the overall GPM system and each contributes to the success of the mission. Errors in the radar measurements and models can adversely affect the retrieved output values. Ground validation (GV) systems are intended to provide timely feedback to the satellite and retrieval algorithms based on measured data. These GV sites will consist of radars and DSD measurement systems and also have intrinsic constraints. One of the retrieval algorithms being studied for use with GPM is the dual-wavelength DSD algorithm that does not use the surface reference technique (SRT). The underlying microphysics of precipitation structures and drop-size distributions (DSDs) dictate the types of models and retrieval algorithms that can be used to estimate precipitation. Many types of dual-wavelength algorithms have been studied. Meneghini (2002) analyzed the performance of single-pass dual-wavelength surface-reference-technique (SRT) based algorithms. Mardiana (2003) demonstrated that a dual-wavelength retrieval algorithm could be successfully used without the use of the SRT. It uses an iterative approach based on measured reflectivities at both wavelengths and complex microphysical models to estimate both No and Do at each range bin. More recently, Liao (2004) proposed a solution to the Do ambiguity problem in rain within the dual-wavelength algorithm and showed a possible melting layer model based on stratified spheres. With the No and Do

  1. Percutaneous Retrieval of Chronic Intravascular Foreign Bodies

    SciTech Connect

    Savage, Clare; Ozkan, Orhan S.; Walser, Eric M.; Wang Dongfang; Zwischenberger, Joseph B.

    2003-09-15

    To evaluate the feasibility of intravascular retrieval of chronic foreign bodies, we retrospectively reviewed an 8 year experience (1993-2001) of percutaneous retrieval of chronically retained intravascular foreign bodies (n = 6). In 6 of 6 cases (4 catheter fragments, 2 guidewires), 5-90 days elapsed before retrieval via the femoral or internal jugular vein. Under fluoroscopy, we determined the foreign body's course, position and size. A guidewire was advanced through a multipurpose catheter to the foreign body. The multipurpose catheter was replaced with a gooseneck snare catheter and the snare advanced to grasp and remove the foreign body. Percutaneous retrieval was successful in all 6 cases. One patient experienced mild hemoptysis, which resolved within 24 hr of observation. No patient experienced long-term sequelae. Given the potential life-threatening complications from intravascular foreign bodies and the low complication rate from percutaneous retrieval, we recommend extraction of the foreign body even if it is asymptomatic in the chronic setting (> 24 hr)

  2. Web information retrieval based on ontology

    NASA Astrophysics Data System (ADS)

    Zhang, Jian

    2013-03-01

    The purpose of the Information Retrieval (IR) is to find a set of documents that are relevant for a specific information need of a user. Traditional Information Retrieval model commonly used in commercial search engine is based on keyword indexing system and Boolean logic queries. One big drawback of traditional information retrieval is that they typically retrieve information without an explicitly defined domain of interest to the users so that a lot of no relevance information returns to users, which burden the user to pick up useful answer from these no relevance results. In order to tackle this issue, many semantic web information retrieval models have been proposed recently. The main advantage of Semantic Web is to enhance search mechanisms with the use of Ontology's mechanisms. In this paper, we present our approach to personalize web search engine based on ontology. In addition, key techniques are also discussed in our paper. Compared to previous research, our works concentrate on the semantic similarity and the whole process including query submission and information annotation.

  3. AIRS Retrieval Validation During the EAQUATE

    NASA Technical Reports Server (NTRS)

    Zhou, Daniel K.; Smith, William L.; Cuomo, Vincenzo; Taylor, Jonathan P.; Barnet, Christopher D.; DiGirolamo, Paolo; Pappalardo, Gelsomina; Larar, Allen M.; Liu, Xu; Newman, Stuart M.

    2006-01-01

    Atmospheric and surface thermodynamic parameters retrieved with advanced hyperspectral remote sensors of Earth observing satellites are critical for weather prediction and scientific research. The retrieval algorithms and retrieved parameters from satellite sounders must be validated to demonstrate the capability and accuracy of both observation and data processing systems. The European AQUA Thermodynamic Experiment (EAQUATE) was conducted mainly for validation of the Atmospheric InfraRed Sounder (AIRS) on the AQUA satellite, but also for assessment of validation systems of both ground-based and aircraft-based instruments which will be used for other satellite systems such as the Infrared Atmospheric Sounding Interferometer (IASI) on the European MetOp satellite, the Cross-track Infrared Sounder (CrIS) from the NPOESS Preparatory Project and the following NPOESS series of satellites. Detailed inter-comparisons were conducted and presented using different retrieval methodologies: measurements from airborne ultraspectral Fourier transform spectrometers, aircraft in-situ instruments, dedicated dropsondes and radiosondes, and ground based Raman Lidar, as well as from the European Center for Medium range Weather Forecasting (ECMWF) modeled thermal structures. The results of this study not only illustrate the quality of the measurements and retrieval products but also demonstrate the capability of these validation systems which are put in place to validate current and future hyperspectral sounding instruments and their scientific products.

  4. Ultraspectral Sounding Retrieval Error Budget and Estimation

    NASA Technical Reports Server (NTRS)

    Zhou, Daniel K.; Larar, Allen M.; Liu, Xu; Smith, William L.; Strow, L. Larrabee; Yang, Ping

    2011-01-01

    The ultraspectral infrared radiances obtained from satellite observations provide atmospheric, surface, and/or cloud information. The intent of the measurement of the thermodynamic state is the initialization of weather and climate models. Great effort has been given to retrieving and validating these atmospheric, surface, and/or cloud properties. Error Consistency Analysis Scheme (ECAS), through fast radiative transfer model (RTM) forward and inverse calculations, has been developed to estimate the error budget in terms of absolute and standard deviation of differences in both spectral radiance and retrieved geophysical parameter domains. The retrieval error is assessed through ECAS without assistance of other independent measurements such as radiosonde data. ECAS re-evaluates instrument random noise, and establishes the link between radiometric accuracy and retrieved geophysical parameter accuracy. ECAS can be applied to measurements of any ultraspectral instrument and any retrieval scheme with associated RTM. In this paper, ECAS is described and demonstration is made with the measurements of the METOP-A satellite Infrared Atmospheric Sounding Interferometer (IASI)..

  5. The transition from memory retrieval to extinction.

    PubMed

    Cammarota, Martín; Barros, Daniela M; Vianna, Mónica R M; Bevilaqua, Lia R M; Coitinho, Adriana; Szapiro, Germán; Izquierdo, Luciana A; Medina, Jorge H; Izquierdo, Iván

    2004-09-01

    Memory is measured by measuring retrieval. Retrieval is often triggered by the conditioned stimulus (CS); however, as known since Pavlov, presentation of the CS alone generates extinction. One-trial avoidance (IA) is a much used conditioned fear paradigm in which the CS is the safe part of a training apparatus, the unconditioned stimulus (US) is a footshock and the conditioned response is to stay in the safe area. In IA, retrieval is measured without the US, as latency to step-down from the safe area (i.e., a platform). Extinction is installed at the moment of the first unreinforced test session, as clearly shown by the fact that many drugs, including PKA, ERK and protein synthesis inhibitors as well as NMDA receptor antagonists, hinder extinction when infused into the hippocampus or the basolateral amygdala at the moment of the first test session but not later. Some, but not all the molecular systems required for extinction are also activated by retrieval, further endorsing the hypothesis that although retrieval is behaviorally and biochemically necessary for the generation of extinction, this last process constitutes a new learning secondary to the unreinforced expression of the original trace.

  6. Extinction learning, which consists of the inhibition of retrieval, can be learned without retrieval.

    PubMed

    de Carvalho Myskiw, Jociane; Furini, Cristiane Regina Guerino; Schmidt, Bianca; Ferreira, Flávia; Izquierdo, Ivan

    2015-01-13

    In the present study we test the hypothesis that extinction is not a consequence of retrieval in unreinforced conditioned stimulus (CS) presentation but the mere perception of the CS in the absence of a conditioned response. Animals with cannulae implanted in the CA1 region of hippocampus were subjected to extinction of contextual fear conditioning. Muscimol infused intra-CA1 before an extinction training session of contextual fear conditioning (CFC) blocks retrieval but not consolidation of extinction measured 24 h later. Additionally, this inhibition of retrieval does not affect early persistence of extinction when tested 7 d later or its spontaneous recovery after 2 wk. Furthermore, both anisomycin, an inhibitor of ribosomal protein synthesis, and rapamycin, an inhibitor of extraribosomal protein synthesis, given into the CA1, impair extinction of CFC regardless of whether its retrieval was blocked by muscimol. Therefore, retrieval performance in the first unreinforced session is not necessary for the installation, maintenance, or spontaneous recovery of extinction of CFC.

  7. STUDIES OF THE DIFFUSE INTERSTELLAR BANDS. IV. THE NEARLY PERFECT CORRELATION BETWEEN lambdalambda6196.0 AND 6613.6

    SciTech Connect

    McCall, Benjamin J.; Drosback, Meredith M.; Snow, Theodore P.; Thorburn, Julie A.; York, Donald G.; Hobbs, L. M.; Friedman, Scott D.; Rachford, Brian L.; Sonnentrucker, Paule; Welty, Daniel E.

    2010-01-10

    In a sample of 114 diffuse cloud sightlines spanning a wide range of interstellar environments, we find the equivalent widths of the diffuse interstellar bands (DIBs) lambda6196.0 and lambda6613.6 to be extremely well correlated, with a correlation coefficient of 0.986. A maximum likelihood functional relationship analysis shows that the observations are consistent with a perfect correlation if the observational errors, which are dominated by continuum placement and other systematics such as interfering lines, have been underestimated by a factor of 2. The quality of this correlation far exceeds other previously studied correlations, such as that between the lambda5780.5 DIB and either the color excess or the atomic hydrogen column density. The unusually tight correlation between these two DIBs would seem to suggest that they might represent the first pair of DIBs known to be due to the same molecular carrier. However, further theoretical work will be required to determine whether the different linewidths and band shapes of these two DIBs can be consistent with a common carrier. If the two DIBs do not in fact share the same molecular carrier, their two carriers must be chemically very closely related.

  8. 200 A GeV Au+Au Collisions Serve a Nearly Perfect Quark-Gluon Liquid

    SciTech Connect

    Song Huichao; Bass, Steffen A.; Heinz, Ulrich; Shen, Chun; Hirano, Tetsufumi

    2011-05-13

    A new robust method to extract the specific shear viscosity ({eta}/s){sub QGP} of a quark-gluon plasma (QGP) at temperatures T{sub c}

  9. Caveats in Transneuronal Tracing with Unmodified Rabies Virus: An Evaluation of Aberrant Results Using a Nearly Perfect Tracing Technique

    PubMed Central

    Ruigrok, Tom J. H.; van Touw, Sven; Coulon, Patrice

    2016-01-01

    Apart from the genetically engineered, modified, strains of rabies virus (RABV), unmodified ‘fixed’ virus strains of RABV, such as the ‘French’ subtype of CVS11, are used to examine synaptically connected networks in the brain. This technique has been shown to have all the prerequisite characteristics for ideal tracing as it does not metabolically affect infected neurons within the time span of the experiment, it is transferred transneuronally in one direction only and to all types of neurons presynaptic to the infected neuron, number of transneuronal steps can be precisely controlled by survival time and it is easily detectable with a sensitive technique. Here, using the ‘French’ CVS 11 subtype of RABV in Wistar rats, we show that some of these characteristics may not be as perfect as previously indicated. Using injection of RABV in hind limb muscles, we show that RABV-infected spinal motoneurons may already show lysis 1 or 2 days after infection. Using longer survival times we were able to establish that Purkinje cells may succumb approximately 3 days after infection. In addition, some neurons seem to resist infection, as we noted that the number of RABV-infected inferior olivary neurons did not progress in the same rate as other infected neurons. Furthermore, in our hands, we noted that infection of Purkinje cells did not result in expected transneuronal labeling of cell types that are presynaptic to Purkinje cells such as molecular layer interneurons and granule cells. However, these cell types were readily infected when RABV was injected directly in the cerebellar cortex. Conversely, neurons in the cerebellar nuclei that project to the inferior olive did not take up RABV when this was injected in the inferior olive, whereas these cells could be infected with RABV via a transneuronal route. These results suggest that viral entry from the extracellular space depends on other factors or mechanisms than those used for retrograde transneuronal transfer. We conclude that transneuronal tracing with RABV may result in unexpected results, as not all properties of RABV seem to be ubiquitously valid. PMID:27462206

  10. Porosity-Permeability Relationships Around the Percolation Threshold in a Near-Perfect Crystalline Rock Under Hydrostatic and Deviatoric Stress.

    NASA Astrophysics Data System (ADS)

    Clint, O. C.; Meredith, P. G.; Main, I. G.

    2001-12-01

    We are investigating the scaling properties of crack populations near the percolation thresholds for fracture and fluid flow. Here we report measurements of changes in fluid permeability and porosity during hydrostatic and deviatoric stressing on samples of Ailsa Craig Microgranite (ACM) with increasing levels of damage. We show virgin ACM to be almost perfectly isotropic with P & S wave velocity anisotropy coefficients of 0.05% and 0.08% respectively. The fluid permeability of the undeformed rock is 1.5 x 10-23 m2 determined at an effective pressure of 10MPa and it has a porosity <<1%. These properties show that ACM is a near-ideal material to investigate the percolation threshold. We have used thermal stressing to different elevated temperatures up to 900° C to induce crack damage in samples of ACM. For hydrostatic experiments; P and S wave velocities and the fluid permeability are then measured on each sample after the heat treatment process. Connected porosity is calculated using a novel ferrofluid saturation technique and the permeability is measured over a range of effective pressures up to 100MPa with a mean pore pressure of 10MPa. For the triaxial deformation experiments; a confining pressure of 40MPa, mean pore fluid pressure of 10MPa and a strain rates of 1.5 x 10-5 s-1 was employed. Permeability and porosity is calculated continuously during deformation from the steady-state flow rate, controlled by a servo-controlled double acting permeameter system. P and S wave velocities reduce by 48% and 32% respectively for thermal stressing up to 800° C, indicating the high level of cracking induced in the sample, while damage is found to remain isotropic over the temperature range, confirmed by magnetic susceptibility measurements. The fluid permeability increases by 7 orders of magnitude and connected crack porosity is increased by 4 orders of magnitude over this temperature range as induced cracks create more pathways available for fluid flow. This resulting behaviour is extremely non-linear in nature as would be expected for a percolation process. The presence and geometry of these induced cracks has also been studied using fluorescent dye microscopy. With permeability and porosity during hydrostatic and deviatoric stressing, we can begin to understand more the behaviour of transport properties around the percolation threshold.

  11. Alignment control of carbon nanotube forest from random to nearly perfectly aligned by utilizing the crowding effect.

    PubMed

    Xu, Ming; Futaba, Don N; Yumura, Motoo; Hata, Kenji

    2012-07-24

    Alignment represents an important structural parameter of carbon nanotubes (CNTs) owing to their exceptionally high aspect ratio, one-dimensional property. In this paper, we demonstrate a general approach to control the alignment of few-walled CNT forests from nearly random to nearly ideally aligned by tailoring the density of active catalysts at the catalyst formation stage, which can be experimentally achieved by controlling the CNT forest mass density. Experimentally, we found that the catalyst density and the degree of alignment were inseparably linked because of a crowding effect from neighboring CNTs, that is, the increasing confinement of CNTs with increased density. Therefore, the CNT density governed the degree of alignment, which increased monotonically with the density. This relationship, in turn, allowed the precise control of the alignment through control of the mass density. To understand this behavior further, we developed a simple, first-order model based on the flexural modulus of the CNTs that could quantitatively describe the relationship between the degree of alignment (HOF) and carbon nanotube spacing (crowding effect) of any type of CNTs.

  12. Caveats in Transneuronal Tracing with Unmodified Rabies Virus: An Evaluation of Aberrant Results Using a Nearly Perfect Tracing Technique.

    PubMed

    Ruigrok, Tom J H; van Touw, Sven; Coulon, Patrice

    2016-01-01

    Apart from the genetically engineered, modified, strains of rabies virus (RABV), unmodified 'fixed' virus strains of RABV, such as the 'French' subtype of CVS11, are used to examine synaptically connected networks in the brain. This technique has been shown to have all the prerequisite characteristics for ideal tracing as it does not metabolically affect infected neurons within the time span of the experiment, it is transferred transneuronally in one direction only and to all types of neurons presynaptic to the infected neuron, number of transneuronal steps can be precisely controlled by survival time and it is easily detectable with a sensitive technique. Here, using the 'French' CVS 11 subtype of RABV in Wistar rats, we show that some of these characteristics may not be as perfect as previously indicated. Using injection of RABV in hind limb muscles, we show that RABV-infected spinal motoneurons may already show lysis 1 or 2 days after infection. Using longer survival times we were able to establish that Purkinje cells may succumb approximately 3 days after infection. In addition, some neurons seem to resist infection, as we noted that the number of RABV-infected inferior olivary neurons did not progress in the same rate as other infected neurons. Furthermore, in our hands, we noted that infection of Purkinje cells did not result in expected transneuronal labeling of cell types that are presynaptic to Purkinje cells such as molecular layer interneurons and granule cells. However, these cell types were readily infected when RABV was injected directly in the cerebellar cortex. Conversely, neurons in the cerebellar nuclei that project to the inferior olive did not take up RABV when this was injected in the inferior olive, whereas these cells could be infected with RABV via a transneuronal route. These results suggest that viral entry from the extracellular space depends on other factors or mechanisms than those used for retrograde transneuronal transfer. We conclude that transneuronal tracing with RABV may result in unexpected results, as not all properties of RABV seem to be ubiquitously valid. PMID:27462206

  13. Dissociating the "retrieval success" regions of the brain: effects of retrieval delay.

    PubMed

    Huijbers, W; Pennartz, C M A; Daselaar, S M

    2010-01-01

    There is abundant evidence that the hippocampal formation critically supports episodic memory retrieval, the remembering of episodes including contextual details. Yet, a group of other brain regions has also been consistently implicated in successful episodic retrieval. This retrieval success network (RSN) includes the posterior midline region, medial prefrontal cortex (mPFC), and posterior parietal cortex (PPC). Despite these consistent findings, the functional roles of the RSN regions remain poorly understood. Given that vivid remembering leads to high-confidence retrieval decisions, it is unclear whether activity in these regions reflects episodic long-term memory, or is merely associated with retrieval confidence. In order to distinguish between these alternatives, we manipulated study-test delays within the context of a continuous recognition task during fMRI-scanning. The design was based on previous evidence indicating that retrieval at short delays is easier leading to high-evidence mnemonic decisions, whereas retrieval at longer delays is more difficult but also more hippocampus-dependent. Confirming previous findings, we found that retrieval decisions at short delays were more accurate and faster, and that the hippocampus showed greater activity at longer delays. Within the other RSN regions, we found three distinct activation patterns as a function of delay. Similar to the hippocampus, the retrosplenial cortex showed increased activity as a function of retrieval delay. Dorsal PPC and the precuneus showed decreased activity. Finally, the posterior cingulate, medial PFC and ventral PPC showed a V-shaped pattern. These findings support the idea that dorsal PPC and the precuneus are involved in decision-related retrieval processes rather than successful remembering.

  14. Retrieving autobiographical memories: How different retrieval strategies associated with different cues explain reaction time differences.

    PubMed

    Uzer, Tugba

    2016-02-01

    Previous research has shown that memories cued by concrete concepts, such as objects, are retrieved faster than those cued by more abstract concepts, such as emotions. This effect has been explained by the fact that more memories are directly retrieved from object versus emotion cues. In the present study, we tested whether RT differences between memories cued by emotion versus object terms occur not only because object cues elicit direct retrieval of more memories (Uzer, Lee, & Brown, 2012), but also because of differences in memory generation in response to emotions versus objects. One hundred university students retrieved memories in response to basic-level (e.g. orange), superordinate-level (e.g. plant), and emotion (e.g. surprised) cues. Retrieval speed was measured and participants reported whether memories were directly retrieved or generated on each trial. Results showed that memories were retrieved faster in response to basic-level versus superordinate-level and emotion cues because a) basic-level cues elicited more directly retrieved memories, and b) generating memories was more difficult when cues were abstract versus concrete. These results suggest that generative retrieval is a cue generation process in which additional cues that provide contextual information including the target event are produced. Memories are retrieved more slowly in response to emotion cues in part because emotion labels are less effective cues of appropriate contextual information. This particular finding is inconsistent with the idea that emotion is a primary organizational unit for autobiographical memories. In contrast, the difficulty of emotional memory generation implies that emotions represent low-level event information in the organization of autobiographical memory.

  15. Melody retrieval on the web

    NASA Astrophysics Data System (ADS)

    Chai, Wei; Vercoe, Barry

    2001-12-01

    This paper explores issues involved in a web-based query-by-humming system, which can find a piece of music in the digital music repository based on hummed melodies. Melody representation, melody matching, melody extraction and query construction are critical for an efficient and robust query-by-humming system and thus the focuses of this paper. Compared to previous systems, a new and more effective melody representation and corresponding melody matching methods which combined both pitch and rhythmic information were adopted, a whole set of tools and deliverable software were implemented, and experiments were conducted to evaluate the system. The experimental results demonstrate that our methods are more effective for most users than other existing methods.

  16. Three-dimensional propagation in near-field tomographic X-ray phase retrieval.

    PubMed

    Ruhlandt, Aike; Salditt, Tim

    2016-03-01

    This paper presents an extension of phase retrieval algorithms for near-field X-ray (propagation) imaging to three dimensions, enhancing the quality of the reconstruction by exploiting previously unused three-dimensional consistency constraints. The approach is based on a novel three-dimensional propagator and is derived for the case of optically weak objects. It can be easily implemented in current phase retrieval architectures, is computationally efficient and reduces the need for restrictive prior assumptions, resulting in superior reconstruction quality. PMID:26919373

  17. Face-sets based video shot retrieval using the text-search analogous approach

    NASA Astrophysics Data System (ADS)

    Liu, Rui; Zhen, Haiyang; Zhu, Ming

    2011-11-01

    The objective of this work is to retrieve shots containing particular people in video material. Due to well known problems such as illumination, pose and expression variations, it has been a challenging task. To this end, a robust and scalable approach analogized with text search method is proposed in this paper, which mainly consists of four steps: Obtaining sets of face exemplars by tracking, Local Facial Features Extraction and Fusion, Visual words established, Document descriptor obtained and VSM established for shot retrieval. Experimental results demonstrate that the proposed approach is not only efficient but also outperforms the competing methods.

  18. Single-Footprint Retrievals from AIRS

    NASA Astrophysics Data System (ADS)

    Irion, F. W.; Fishbein, E.; Fu, D.; Hulley, G. C.; Kahn, B. H.; Schreier, M. M.; Yue, Q.; Wong, S.; Strow, L. L.; Desouza-Machado, S. G.; Kulawik, S. S.

    2014-12-01

    The Atmospheric Infrared Sounder, on the EOS-Aqua platform, retrieves temperature, water vapor and ozone profiles (among other constituents) in the thermal infrared, as well as cloud and aerosol information. The production version retrieves profiles using L2 cloud-cleared radiances, which are created using spectral data from adjacent scenes and data from the co-located AMSU microwave instrument. Current AIRS L2 profiles have a horizontal footprint of ~40 km at nadir. We present a new research retrieval using cloudy radiances directly from AIRS L1b radiances under an optimal estimation framework. Using co-located MODIS cloud results as a priori, and updated emissivitivies derived from a new database derived from ASTER and MODIS, this reduces the nadir footprint to 13.5 km. We present early L2 results from this effort and describe how this effort will be used to better understand the atmospheric water cycle.

  19. Nonstationary signal analysis in episodic memory retrieval

    NASA Astrophysics Data System (ADS)

    Ku, Y. G.; Kawasumi, Masashi; Saito, Masao

    2004-04-01

    The problem of blind source separation from a mixture that has nonstationarity can be seen in signal processing, speech processing, spectral analysis and so on. This study analyzed EEG signal during episodic memory retrieval using ICA and TVAR. This paper proposes a method which combines ICA and TVAR. The signal from the brain not only exhibits the nonstationary behavior, but also contain artifacts. EEG data at the frontal lobe (F3) from the scalp is collected during the episodic memory retrieval task. The method is applied to EEG data for analysis. The artifact (eye movement) is removed by ICA, and a single burst (around 6Hz) is obtained by TVAR, suggesting that the single burst is related to the brain activity during the episodic memory retrieval.

  20. Conditions under which lorazepam can facilitate retrieval.

    PubMed

    File, S E; Fluck, E; Joyce, E M

    1999-08-01

    Memory is composed of three stages: acquisition, consolidation, and retrieval. By impairing acquisition processes, benzodiazepines cause anterograde amnesia while leaving intact information learned before the drug was taken. In some circumstances, retrieval of this information is even improved by benzodiazepines. It has been hypothesized that this phenomenon is not a true facilitation of retrieval processes, but is the result of reduced interference from items presented after drug administration and is thus a secondary consequence of drug-induced amnesia. Experiment 1 investigated the effect of 0.5, 1, and 2.5 mg of lorazepam on explicit episodic memory in healthy young volunteers. The 1-mg dose was found to significantly improve recall of items presented before drug administration without causing amnesia for items presented after drug administration, thus excluding an interference explanation. Experiment 2 investigated the conditions necessary to obtain facilitated retrieval with 1 mg of lorazepam. The results showed that facilitation was found only when two lists of semantically related material were presented, but that both of the lists could be presented before drug administration, thus excluding an effect of lorazepam on consolidation. Facilitation could be demonstrated in both direct (free recall) and indirect (backwards reading) retrieval tasks and when all of the material was presented after lorazepam administration. This improved retrieval could therefore be of clinical relevance, but any benefits would be reduced at higher doses that at the same time impair acquisition of new information. However, because 1 mg of lorazepam is an effective anxiolytic dose, these results suggest that it is possible to combine effective anxiety reduction with some benefits to memory.

  1. Evolutionary Computing Methods for Spectral Retrieval

    NASA Technical Reports Server (NTRS)

    Terrile, Richard; Fink, Wolfgang; Huntsberger, Terrance; Lee, Seugwon; Tisdale, Edwin; VonAllmen, Paul; Tinetti, Geivanna

    2009-01-01

    A methodology for processing spectral images to retrieve information on underlying physical, chemical, and/or biological phenomena is based on evolutionary and related computational methods implemented in software. In a typical case, the solution (the information that one seeks to retrieve) consists of parameters of a mathematical model that represents one or more of the phenomena of interest. The methodology was developed for the initial purpose of retrieving the desired information from spectral image data acquired by remote-sensing instruments aimed at planets (including the Earth). Examples of information desired in such applications include trace gas concentrations, temperature profiles, surface types, day/night fractions, cloud/aerosol fractions, seasons, and viewing angles. The methodology is also potentially useful for retrieving information on chemical and/or biological hazards in terrestrial settings. In this methodology, one utilizes an iterative process that minimizes a fitness function indicative of the degree of dissimilarity between observed and synthetic spectral and angular data. The evolutionary computing methods that lie at the heart of this process yield a population of solutions (sets of the desired parameters) within an accuracy represented by a fitness-function value specified by the user. The evolutionary computing methods (ECM) used in this methodology are Genetic Algorithms and Simulated Annealing, both of which are well-established optimization techniques and have also been described in previous NASA Tech Briefs articles. These are embedded in a conceptual framework, represented in the architecture of the implementing software, that enables automatic retrieval of spectral and angular data and analysis of the retrieved solutions for uniqueness.

  2. Trends in medical information retrieval on Internet.

    PubMed

    Baujard, O; Baujard, V; Aurel, S; Boyer, C; Appel, R D

    1998-09-01

    Information on the World Wide Web is unstructured, distributed, multimedia and multilingual. Many tools have been developed to help users search for useful information: subject hierarchies, general search engines, browsers and search assistants. Although helpful, they present serious limitations, mainly in terms of precision, multilingual indexing and distribution. In this paper, we cover some on-line solutions to medical information discovery and present our own approach, the MARVIN (multi-agent retrieval vagabond on information network) project, which tackles medical information research with specialized cooperative retrieval agents. We also draw some outlines for future extensions. PMID:9861514

  3. [Brain Mechanism for Successful Memory Retrieval].

    PubMed

    Takeda, Masaki

    2016-04-01

    Previous neuropsychological studies that investigated patients with brain injury have revealed the presense of multiple memory systems and the related brain regions. Recent functional imaging studies have identified a neuronal network including the temporal cortex and hippocampus that is responsible for the retrieval of semantic memory. This memory network was further investigated by electrophysiology using a simultaneous recording technique. This new technique revealed that a coupling of inter-area top-down signal within the temporal cortex with translaminar signal processing is required for successful memory retrieval of visual objects.

  4. Surface UV retrieval from satellite data.

    PubMed

    Tikkanen, T

    2000-01-01

    Irradiance of biologically effective ultraviolet radiation on the Earth's surface is retrieved from satellite measurements using radiative transfer models. Retrieval methods are reviewed with a special emphasis on questions pertinent to the Arctic environment. In general, the main problem is the high variability of cloudiness. The most prominent features of high latitudes are the low Sun and the high UV reflectivity of snow-covered terrain. Being white like clouds, snow is a challenge for satellite imagery. The dependence of UV albedo on the properties of snow and ambient conditions is discussed. The use of auxiliary snow cover data from a meteorological model is planned.

  5. Practical video indexing and retrieval system

    NASA Astrophysics Data System (ADS)

    Liang, Yiqing; Wolf, Wayne H.; Liu, Bede; Huang, Jeffrey R.

    1998-03-01

    We integrated a practical digital video database system based on language and image analysis with components from digital video processing, still image search, information retrieval, closed captioning processing. The attempt is to utilize the multiple modalities of information in video and implement data fusion among the multiple modalities; image information, speech/dialog information, closed captioning information, sound track information such as music, gunfire, explosion, caption information, motion information, temporal information. Effort is made to allow access video contents at different levels including video program level, scene level, shot level, and object level. Approaches of browsing, subject-based classification, and random retrieving are available to gain access to the contents.

  6. Scaling laws of associative memory retrieval.

    PubMed

    Romani, Sandro; Pinkoviezky, Itai; Rubin, Alon; Tsodyks, Misha

    2013-10-01

    Most people have great difficulty in recalling unrelated items. For example, in free recall experiments, lists of more than a few randomly selected words cannot be accurately repeated. Here we introduce a phenomenological model of memory retrieval inspired by theories of neuronal population coding of information. The model predicts nontrivial scaling behaviors for the mean and standard deviation of the number of recalled words for lists of increasing length. Our results suggest that associative information retrieval is a dominating factor that limits the number of recalled items.

  7. Development of microwave rainfall retrieval algorithm for climate applications

    NASA Astrophysics Data System (ADS)

    KIM, J. H.; Shin, D. B.

    2014-12-01

    With the accumulated satellite datasets for decades, it is possible that satellite-based data could contribute to sustained climate applications. Level-3 products from microwave sensors for climate applications can be obtained from several algorithms. For examples, the Microwave Emission brightness Temperature Histogram (METH) algorithm produces level-3 rainfalls directly, whereas the Goddard profiling (GPROF) algorithm first generates instantaneous rainfalls and then temporal and spatial averaging process leads to level-3 products. The rainfall algorithm developed in this study follows a similar approach to averaging instantaneous rainfalls. However, the algorithm is designed to produce instantaneous rainfalls at an optimal resolution showing reduced non-linearity in brightness temperature (TB)-rain rate(R) relations. It is found that the resolution tends to effectively utilize emission channels whose footprints are relatively larger than those of scattering channels. This algorithm is mainly composed of a-priori databases (DBs) and a Bayesian inversion module. The DB contains massive pairs of simulated microwave TBs and rain rates, obtained by WRF (version 3.4) and RTTOV (version 11.1) simulations. To improve the accuracy and efficiency of retrieval process, data mining technique is additionally considered. The entire DB is classified into eight types based on Köppen climate classification criteria using reanalysis data. Among these sub-DBs, only one sub-DB which presents the most similar physical characteristics is selected by considering the thermodynamics of input data. When the Bayesian inversion is applied to the selected DB, instantaneous rain rate with 6 hours interval is retrieved. The retrieved monthly mean rainfalls are statistically compared with CMAP and GPCP, respectively.

  8. A comparison of Boolean-based retrieval to the WAIS system for retrieval of aeronautical information

    NASA Technical Reports Server (NTRS)

    Marchionini, Gary; Barlow, Diane

    1994-01-01

    An evaluation of an information retrieval system using a Boolean-based retrieval engine and inverted file architecture and WAIS, which uses a vector-based engine, was conducted. Four research questions in aeronautical engineering were used to retrieve sets of citations from the NASA Aerospace Database which was mounted on a WAIS server and available through Dialog File 108 which served as the Boolean-based system (BBS). High recall and high precision searches were done in the BBS and terse and verbose queries were used in the WAIS condition. Precision values for the WAIS searches were consistently above the precision values for high recall BBS searches and consistently below the precision values for high precision BBS searches. Terse WAIS queries gave somewhat better precision performance than verbose WAIS queries. In every case, a small number of relevant documents retrieved by one system were not retrieved by the other, indicating the incomplete nature of the results from either retrieval system. Relevant documents in the WAIS searches were found to be randomly distributed in the retrieved sets rather than distributed by ranks. Advantages and limitations of both types of systems are discussed.

  9. Forgetting as a consequence of retrieval: a meta-analytic review of retrieval-induced forgetting.

    PubMed

    Murayama, Kou; Miyatsu, Toshiya; Buchli, Dorothy; Storm, Benjamin C

    2014-09-01

    Retrieving a subset of items can cause the forgetting of other items, a phenomenon referred to as retrieval-induced forgetting. According to some theorists, retrieval-induced forgetting is the consequence of an inhibitory mechanism that acts to reduce the accessibility of nontarget items that interfere with the retrieval of target items. Other theorists argue that inhibition is unnecessary to account for retrieval-induced forgetting, contending instead that the phenomenon can be best explained by noninhibitory mechanisms, such as strength-based competition or blocking. The current article provides the first major meta-analysis of retrieval-induced forgetting, conducted with the primary purpose of quantitatively evaluating the multitude of findings that have been used to contrast these 2 theoretical viewpoints. The results largely supported inhibition accounts but also provided some challenging evidence, with the nature of the results often varying as a function of how retrieval-induced forgetting was assessed. Implications for further research and theory development are discussed. PMID:25180807

  10. Rapid storage and retrieval of genomic intervals from a relational database system using nested containment lists.

    PubMed

    Wiley, Laura K; Sivley, R Michael; Bush, William S

    2013-01-01

    Efficient storage and retrieval of genomic annotations based on range intervals is necessary, given the amount of data produced by next-generation sequencing studies. The indexing strategies of relational database systems (such as MySQL) greatly inhibit their use in genomic annotation tasks. This has led to the development of stand-alone applications that are dependent on flat-file libraries. In this work, we introduce MyNCList, an implementation of the NCList data structure within a MySQL database. MyNCList enables the storage, update and rapid retrieval of genomic annotations from the convenience of a relational database system. Range-based annotations of 1 million variants are retrieved in under a minute, making this approach feasible for whole-genome annotation tasks. Database URL: https://github.com/bushlab/mynclist. PMID:23894185

  11. Rapid storage and retrieval of genomic intervals from a relational database system using nested containment lists.

    PubMed

    Wiley, Laura K; Sivley, R Michael; Bush, William S

    2013-01-01

    Efficient storage and retrieval of genomic annotations based on range intervals is necessary, given the amount of data produced by next-generation sequencing studies. The indexing strategies of relational database systems (such as MySQL) greatly inhibit their use in genomic annotation tasks. This has led to the development of stand-alone applications that are dependent on flat-file libraries. In this work, we introduce MyNCList, an implementation of the NCList data structure within a MySQL database. MyNCList enables the storage, update and rapid retrieval of genomic annotations from the convenience of a relational database system. Range-based annotations of 1 million variants are retrieved in under a minute, making this approach feasible for whole-genome annotation tasks. Database URL: https://github.com/bushlab/mynclist.

  12. Design of knowledge-based image retrieval system: implications from radiologists' cognitive processes

    NASA Astrophysics Data System (ADS)

    Liu Sheng, Olivia R.; Wei, Chih-Ping; Ozeki, Takeshi; Ovitt, Theron W.; Ishida, Jiro

    1992-07-01

    In a radiological examination reading, radiologists usually compare a newly generated examination with previous examinations of the same patient. For this reason, the retrieval of old images is a critical design requirement of totally digital radiology using Picture Archiving and Communication Systems (PACS). To achieve the required performance in a PACS with a hierarchical and possibly distributed image archival system, pre-fetching of images from slower or remote storage devices to the local buffers of workstations is proposed. Image Retrieval Expert System (IRES) is a knowledge-based image retrieval system which will predict and then pre-fetch relevant old images. Previous work on IRES design focused on the knowledge acquisition phase and the development of an efficient modeling methodology and architecture. The goal of this paper is to evaluate the effectiveness of the current IRES design and to identify appropriate directions for exploring other design features and alternatives by means of a cognitive study and an associated survey study.

  13. FRESCO+: an improved O2 A-band cloud retrieval algorithm for tropospheric trace gas retrievals

    NASA Astrophysics Data System (ADS)

    Wang, P.; Stammes, P.; van der A, R.; Pinardi, G.; van Roozendael, M.

    2008-11-01

    The FRESCO (Fast Retrieval Scheme for Clouds from the Oxygen A-band) algorithm has been used to retrieve cloud information from measurements of the O2 A-band around 760 nm by GOME, SCIAMACHY and GOME-2. The cloud parameters retrieved by FRESCO are the effective cloud fraction and cloud pressure, which are used for cloud correction in the retrieval of trace gases like O3 and NO2. To improve the cloud pressure retrieval for partly cloudy scenes, single Rayleigh scattering has been included in an improved version of the algorithm, called FRESCO+. We compared FRESCO+ and FRESCO effective cloud fractions and cloud pressures using simulated spectra and one month of GOME measured spectra. As expected, FRESCO+ gives more reliable cloud pressures over partly cloudy pixels. Simulations and comparisons with ground-based radar/lidar measurements of clouds show that the FRESCO+ cloud pressure is about the optical midlevel of the cloud. Globally averaged, the FRESCO+ cloud pressure is about 50 hPa higher than the FRESCO cloud pressure, while the FRESCO+ effective cloud fraction is about 0.01 larger. The effect of FRESCO+ cloud parameters on O3 and NO2 vertical column density (VCD) retrievals is studied using SCIAMACHY data and ground-based DOAS measurements. We find that the FRESCO+ algorithm has a significant effect on tropospheric NO2 retrievals but a minor effect on total O3 retrievals. The retrieved SCIAMACHY tropospheric NO2 VCDs using FRESCO+ cloud parameters (v1.1) are lower than the tropospheric NO2VCDs which used FRESCO cloud parameters (v1.04), in particular over heavily polluted areas with low clouds. The difference between SCIAMACHY tropospheric NO2 VCDs v1.1 and ground-based MAXDOAS measurements performed in Cabauw, The Netherlands, during the DANDELIONS campaign is about -2.12×1014molec cm-2.

  14. Long-Term Health Effects of Neutering Dogs: Comparison of Labrador Retrievers with Golden Retrievers

    PubMed Central

    Hart, Benjamin L.; Hart, Lynette A.; Thigpen, Abigail P.; Willits, Neil H.

    2014-01-01

    Our recent study on the effects of neutering (including spaying) in Golden Retrievers in markedly increasing the incidence of two joint disorders and three cancers prompted this study and a comparison of Golden and Labrador Retrievers. Veterinary hospital records were examined over a 13-year period for the effects of neutering during specified age ranges: before 6 mo., and during 6–11 mo., year 1 or years 2 through 8. The joint disorders examined were hip dysplasia, cranial cruciate ligament tear and elbow dysplasia. The cancers examined were lymphosarcoma, hemangiosarcoma, mast cell tumor, and mammary cancer. The results for the Golden Retriever were similar to the previous study, but there were notable differences between breeds. In Labrador Retrievers, where about 5 percent of gonadally intact males and females had one or more joint disorders, neutering at <6 mo. doubled the incidence of one or more joint disorders in both sexes. In male and female Golden Retrievers, with the same 5 percent rate of joint disorders in intact dogs, neutering at <6 mo. increased the incidence of a joint disorder to 4–5 times that of intact dogs. The incidence of one or more cancers in female Labrador Retrievers increased slightly above the 3 percent level of intact females with neutering. In contrast, in female Golden Retrievers, with the same 3 percent rate of one or more cancers in intact females, neutering at all periods through 8 years of age increased the rate of at least one of the cancers by 3–4 times. In male Golden and Labrador Retrievers neutering had relatively minor effects in increasing the occurrence of cancers. Comparisons of cancers in the two breeds suggest that the occurrence of cancers in female Golden Retrievers is a reflection of particular vulnerability to gonadal hormone removal. PMID:25020045

  15. Strategic retrieval and retrieval orientation in reality monitoring studied by event-related potentials (ERPs).

    PubMed

    Rosburg, Timm; Johansson, Mikael; Mecklinger, Axel

    2013-02-01

    Reality monitoring requires the differentiation between perceived and imagined events or between our own actions and the actions of others. The role of control processes in reality monitoring is yet not fully understood. In the current event-related potential (ERP) study, we investigated such control processes in the form of retrieval orientation and strategic retrieval of nontarget information. At study, complete or incomplete object words were presented in sentences. Participants had to identify the words as the subject of the sentence (perceive condition) or had to complete them upon presentation of a word fragment (self-generate condition). The participants' memory accuracy was better for generated items than for perceived items, as tested in a subsequent memory exclusion task. Comparison of ERPs to new items between the two test conditions (i.e. assessing retrieval orientation) showed more positive ERPs when generated object names were targeted. Retrieval orientation also modulated the early midfrontal old/new effect: Items of the self-generate condition elicited this effect irrespective of their target/nontarget status, while in response to the less well remembered items of the perceive condition it was only found when these items were defined as targets. Target retrieval (as reflected in the left-parietal old/new effect) occurred in both test conditions, but nontarget retrieval was observed only for generated items (when perceived items were targeted). Current findings indicate that retrieval orientation can modulate familiarity-related processes. The selective occurrence of nontarget retrieval for generated items corroborates the concept that the ease with which nontarget information can be accessed promotes nontarget retrieval.

  16. User centered and ontology based information retrieval system for life sciences

    PubMed Central

    2012-01-01

    Background Because of the increasing number of electronic resources, designing efficient tools to retrieve and exploit them is a major challenge. Some improvements have been offered by semantic Web technologies and applications based on domain ontologies. In life science, for instance, the Gene Ontology is widely exploited in genomic applications and the Medical Subject Headings is the basis of biomedical publications indexation and information retrieval process proposed by PubMed. However current search engines suffer from two main drawbacks: there is limited user interaction with the list of retrieved resources and no explanation for their adequacy to the query is provided. Users may thus be confused by the selection and have no idea on how to adapt their queries so that the results match their expectations. Results This paper describes an information retrieval system that relies on domain ontology to widen the set of relevant documents that is retrieved and that uses a graphical rendering of query results to favor user interactions. Semantic proximities between ontology concepts and aggregating models are used to assess documents adequacy with respect to a query. The selection of documents is displayed in a semantic map to provide graphical indications that make explicit to what extent they match the user's query; this man/machine interface favors a more interactive and iterative exploration of data corpus, by facilitating query concepts weighting and visual explanation. We illustrate the benefit of using this information retrieval system on two case studies one of which aiming at collecting human genes related to transcription factors involved in hemopoiesis pathway. Conclusions The ontology based information retrieval system described in this paper (OBIRS) is freely available at: http://www.ontotoolkit.mines-ales.fr/ObirsClient/. This environment is a first step towards a user centred application in which the system enlightens relevant information to provide

  17. Retrievability of the Physical Parameters for Frozen Precipitation

    NASA Astrophysics Data System (ADS)

    Niamsuwan, N.

    2010-12-01

    With a newly designed dual frequency radar and higher frequency channels of its microwave imager, Global Precipitation Measurement (GPM) satellite soon will extend the observation capabilities of its predecessor program, Tropical Rainfall Measuring Mission (TRMM), to include snow and light rain. Detection of frozen precipitation such as snow is complicated by the fact that the morphologies of snow crystals and their aggregates are much more variable than the liquid kinds. To evaluate the significant of the variability of the snow particles’ geometry and orientation, forward simulations for the scattering/emission/absorption properties for a single particle and the ensemble of particles under realistic assumptions are needed. This presentation reports an examination of the retrievability of the physical parameters of the frozen particles using Instrument Simulator Suite for Atmospheric Remote Sensing (ISSARS) system. With ISSARS’ current capability to efficiently compute the scattering characteristics of the atmosphere simulated by widely used numerical programs, a variety of atmospheric scenarios with different geophysical assumptions can be studied using ISSARS as a test bed. The variability of radiative properties and their sensitivity to the change in physical parameters (size, shape, and orientation) will also be presented. These knowledge can allow a complex set of particle descriptions to be represented by a simpler variant. An ability to retrieve these parameters using GPM instruments will also be addressed.

  18. Image retrieval based on local grey-level invariants

    NASA Astrophysics Data System (ADS)

    Bordeaux, Eva; Shrikhande, Neelima

    2005-10-01

    During past decades, the enormous growth of image archives has significantly increased the demand for research efforts aimed at efficiently finding specific images within large databases. This paper investigates matching of images of buildings, architectural designs, blueprints and sketches. Their geometrical constrains lead to the proposed approach: the use of local grey-level invariants based on internal contours of the object. The problem involves three key phases: object recognition in image data, matching two images and searching the database of images. The emphasis of this paper is on object recognition based on internal contours of image data. In her master's thesis, M.M. Kulkarni described a technique for image retrieval by contour analysis implemented on external contours of an object in an image data. This is used to define the category of a building (tower, dome, flat, etc). Integration of these results with local grey-level invariant analysis creates a more robust image retrieval system. Thus, the best match result is the intersection of the results of contour analysis and grey-level invariants analysis. Experiments conducted for the database of architectural buildings have shown robustness w.r.t. to image rotation, translation, small view-point variations, partial visibility and extraneous features. The recognition rate is above 99% for a variety of tested images taken under different conditions.

  19. Advances in audio source seperation and multisource audio content retrieval

    NASA Astrophysics Data System (ADS)

    Vincent, Emmanuel

    2012-06-01

    Audio source separation aims to extract the signals of individual sound sources from a given recording. In this paper, we review three recent advances which improve the robustness of source separation in real-world challenging scenarios and enable its use for multisource content retrieval tasks, such as automatic speech recognition (ASR) or acoustic event detection (AED) in noisy environments. We present a Flexible Audio Source Separation Toolkit (FASST) and discuss its advantages compared to earlier approaches such as independent component analysis (ICA) and sparse component analysis (SCA). We explain how cues as diverse as harmonicity, spectral envelope, temporal fine structure or spatial location can be jointly exploited by this toolkit. We subsequently present the uncertainty decoding (UD) framework for the integration of audio source separation and audio content retrieval. We show how the uncertainty about the separated source signals can be accurately estimated and propagated to the features. Finally, we explain how this uncertainty can be efficiently exploited by a classifier, both at the training and the decoding stage. We illustrate the resulting performance improvements in terms of speech separation quality and speaker recognition accuracy.

  20. Information Management For Data Retrieval In A PACS

    NASA Astrophysics Data System (ADS)

    Prior, Fred W.; Nabijee, Kamal H.

    1989-05-01

    Data stored in a PACS archive must be organized to permit efficient retrieval. The concept of a unique data object identifier (UID) permits a fundamental partitioning of the problem into a storage system indexed by UID and a database containing descriptive elements. The database serves to map user retrieval requests, expressed in terms of clinically relevant descriptive elements, into UIDs of specific data objects. Different data organization mechanisms are employed by imaging modalities, thereby making the structure of a generic PACS database difficult. One solution may be derived by analogy from film based systems. Images and other data objects may be organized, by application of modality and site specific rules, into electronic folders. Folders, in turn may be organized into a patient master folder or user defined reference folders. Such an organization provides an easily understood user access model for information stored in PACS archives. This paper presents a PACS architecture comprising an Information Management System (IMS), and Image Storage System (ISS). Entity-Relationship diagrams are presented to define a schema for the IMS database based on the folder analogy. The folder concept and its relationship to the ACR-NEMA Standard are discussed.

  1. Multimedia content analysis, management and retrieval: trends and challenges

    NASA Astrophysics Data System (ADS)

    Hanjalic, Alan; Sebe, Nicu; Chang, Edward

    2006-01-01

    Recent advances in computing, communications and storage technology have made multimedia data become prevalent. Multimedia has gained enormous potential in improving the processes in a wide range of fields, such as advertising and marketing, education and training, entertainment, medicine, surveillance, wearable computing, biometrics, and remote sensing. Rich content of multimedia data, built through the synergies of the information contained in different modalities, calls for new and innovative methods for modeling, processing, mining, organizing, and indexing of this data for effective and efficient searching, retrieval, delivery, management and sharing of multimedia content, as required by the applications in the abovementioned fields. The objective of this paper is to present our views on the trends that should be followed when developing such methods, to elaborate on the related research challenges, and to introduce the new conference, Multimedia Content Analysis, Management and Retrieval, as a premium venue for presenting and discussing these methods with the scientific community. Starting from 2006, the conference will be held annually as a part of the IS&T/SPIE Electronic Imaging event.

  2. Bibliographic Information Retrieval Systems: Increasing Cognitive Compatibility.

    ERIC Educational Resources Information Center

    Smith, Philip J.; And Others

    1987-01-01

    Discusses the impact of research in artificial intelligence and human computer interaction on the design of bibliographic information retrieval systems, and presents design principles of a prototype system that uses semantically based searches and a knowledge base consisting of conceptual frames. (10 references) (CLB)

  3. Retrieval, Analysis, and Display of Numeric Data.

    ERIC Educational Resources Information Center

    Berger, Mary C.; Wanger, Judith

    1982-01-01

    This introduction to online numeric database systems describes the types of databases associated with such systems, shows the major functions which they can perform (retrieval, analysis, display), and identifies the major characteristics of user interfaces. Examples of numeric database use are appended. (EJS)

  4. Loss of Retrieval Information in Prose Recall.

    ERIC Educational Resources Information Center

    Sehulster, Jerome R.; And Others

    The purpose of this research was to experimentally manipulate input and output orders of information and separate storage and retrieval components of prose free recall. The cued partial recall method, used in word list recall, was adapted to a prose learning task. Four short biographical stories of about 55 words each were systematically combined…

  5. Retrieving Information from a Hierarchical Plan

    ERIC Educational Resources Information Center

    Schneider, Darryl W.; Logan, Gordon D.

    2007-01-01

    Plans give structure to behavior by specifying whether and when different tasks must be performed. However, the structure of behavior need not mirror the structure of the plan. To investigate this idea, the authors studied how plan information is retrieved in the context of a novel sequence-position cuing procedure, wherein subjects memorize two…

  6. Online Literature Retrieval: An Alternative Strategy.

    ERIC Educational Resources Information Center

    Piotrowski, Chris; Perdue, Robert

    This study investigated the efficacy of utilizing comprehensive database search strategies in performing an online literature search in the subject area of psychology, with special interest in the performance of the database PsycInfo. The DIALOG Information Retrieval Service's DIALINDEX subject category options were used as the major search…

  7. Millennial Students' Mental Models of Information Retrieval

    ERIC Educational Resources Information Center

    Holman, Lucy

    2009-01-01

    This qualitative study examines first-year college students' online search habits in order to identify patterns in millennials' mental models of information retrieval. The study employed a combination of modified contextual inquiry and concept mapping methodologies to elicit students' mental models. The researcher confirmed previously observed…

  8. Simulating Network Retrieval of Arithmetic Facts.

    ERIC Educational Resources Information Center

    Ashcraft, Mark H.

    This report describes a simulation of adults' retrieval of arithmetic facts from a network-based memory representation. The goals of the simulation project are to: demonstrate in specific form the nature of a spreading activation model of mental arithmetic; account for three important reaction time effects observed in laboratory investigations;…

  9. Neural Systems behind Word and Concept Retrieval

    ERIC Educational Resources Information Center

    Damasio, H.; Tranel, D.; Grabowski, T.; Adolphs, R.; Damasio, A.

    2004-01-01

    Using both the lesion method and functional imaging (positron emission tomography) in large cohorts of subjects investigated with the same experimental tasks, we tested the following hypotheses: (A) that the retrieval of words which denote concrete entities belonging to distinct conceptual categories depends upon partially segregated regions in…

  10. Interaction in Information Searching and Retrieval.

    ERIC Educational Resources Information Center

    Beaulieu, Micheline

    2000-01-01

    Explores the concepts of interaction and interactivity presented in different theoretical models in the fields of human-computer interaction (HCI) and information-seeking/searching behavior, and relates these to information retrieval (IR) research. Suggests that interaction in HCI is primarily concerned with establishing a user/system dialogue at…

  11. Document Retrieval Systems; Factors Affecting Search Time.

    ERIC Educational Resources Information Center

    Montgomery, K. Leon, Ed.

    An experiment was conducted to identify some of the important parameters affecting search time, a critical cost factor in retrieval systems. Using actual computer searches of Chemical Abstracts Condensate, a comparison was made between the effectiveness of linear and inverted filing systems. Since the results indicated that it was the type and…

  12. An improved glyoxal retrieval from OMI measurements

    NASA Astrophysics Data System (ADS)

    Alvarado, L. M. A.; Richter, A.; Vrekoussis, M.; Wittrock, F.; Hilboll, A.; Schreier, S. F.; Burrows, J. P.

    2014-06-01

    Satellite observations from the SCIAMACHY, GOME-2, and OMI spectrometers have been used to retrieve atmospheric columns of glyoxal (CHOCHO) with the DOAS method. High CHOCHO levels are found over regions with large biogenic and pyrogenic emissions, and hot-spots have been identified over areas of anthropogenic activities. This study focuses on the development of an improved retrieval for CHOCHO from measurements by the OMI instrument. From sensitivity tests, an optimal fitting window and polynomial degree are determined. Two different approaches to reduce the interference of liquid water absorption over oceanic regions are evaluated, achieving significant reduction of negative columns over clear water regions. Moreover, a high temperature absorption cross-section of nitrogen dioxide (NO2) is introduced in the DOAS retrieval to account for potential interferences of NO2 over regions with large anthropogenic emissions, leading to improved fit quality over these areas. A comparison with vertical CHOCHO columns retrieved from measurements of the GOME-2 and SCIAMACHY instruments over continental regions is performed, showing overall good consistency. Using the new OMI CHOCHO data set, the link between fires and glyoxal columns is investigated for two selected regions in Africa. In addition, mapped averages are computed for a fire event in the east of Moscow between mid-July and mid-August 2010. In both cases, enhanced CHOCHO levels are found in close spatial and temporal proximity to MODIS fire radiative power, demonstrating that pyrogenic emissions can be clearly identified in the OMI CHOCHO product.

  13. Fernald Silo Remote Retrieval Tool Development

    SciTech Connect

    Varma, V.K.

    2004-05-18

    A long-reach tool was developed to remove discrete objects from the silos at the Fernald Environmental Management Project in Ohio. If they are not removed, these objects can potentially cause problems during the retrieval and transfer of waste from the silos. Most of the objects are on top of the Bentogrout cap inside the silos at or near the primary opening into the tank and will therefore require only vertical lifting. The objects are located about 20 ft from the top of the silo. Although most of the objects can be retrieved from 20 ft, the long-reach tool was designed to for a reach up to 40 ft in case objects roll towards the walls of the tank or need to be removed during heel retrieval operations. This report provides a detailed description of the tool that was developed, tested, and demonstrated at the Tanks Technology Cold Test Facility at Oak Ridge National Laboratory. Scaffolding was erected over two experimental cells to simulate the 40-ft maximum working depth anticipated in the silos at Fernald. Plastic bottles and plastic sheeting simulated the debris that could be encountered during waste retrieval operations.

  14. A Microprocessor Architecture for Bibliographic Retrieval System.

    ERIC Educational Resources Information Center

    Martella, G.; Gobbi, G.

    1981-01-01

    Proposes a microprocessor-based architecture that makes large use of parallelism both in processing and in retrieval operations. The proposed system consists of three functional blocks: the query processor, simple query executers, and the answer composer. Twenty-one references are listed. (FM)

  15. Exploring biases in exoplanet spectroscopy retrievals

    NASA Astrophysics Data System (ADS)

    Feng, Ying; Fortney, Jonathan; Line, Michael R.; Morley, Caroline

    2015-12-01

    Spectra from the atmospheres of transiting planets and imaged planets are now being routinely achieved. The interpretation of these spectra gives us a window into the physics and chemistry of these atmospheres, as well as a better understanding of planet formation. Over the past several years retrievals of exoplanet spectra have been used to obtain chemical abundances and thermal structures, along with assessments of uncertainties on these quantities. However, any potential biases inherent in these methods have yet to be fully explored. The atmospheres we observe are inherently three-dimensional (3D) structures that feature gradients in temperatures and chemical abundances, as well as hot spots, cold spots, storms, and cloud patchiness. How well does the assumption of retrieving 1D hemispheric average conditions represent the true state of a 3D atmosphere? Can we be led astray? Answering these questions are important today, and will only become more important as data quality improves. Using a descendent of the CHIMERA retrieval code, here I present the results of how retrievals perform on more complex scenarios. We start with the emitted spectrum from the average of two pressure-temperature profiles, one warmer, one colder, and move on to more sophisticated, but still realistic, scenarios. Our work makes use of a new code we have developed to construct spectra from arbitrary 3D model atmospheres.

  16. Improving aerosol retrieval over urban areas

    NASA Astrophysics Data System (ADS)

    Picón, A. J.; Wu, Y.; Gross, B.; Moshary, F.; Ahmed, S. A.

    2010-12-01

    Aerosol retrieval over urban areas is complicated since surface models in the operational algorithms are based on vegetation models such as the case of MODIS. To improve satellite retrieval of aerosols in urban areas, we use simultaneous AERONET radiometer and MODIS measurements in combination to refine surface albedo models. Refined surface models have been implemented for NYC and Mexico City demonstrating significant improvement in AOD in terms of accuracy and spatial resolution. Based on these direct retrievals of the surface reflection for the MODIS Land Aerosol Bands, we were able to show that current parameterizations of the surface as a function of the Modified Vegetation Index are not in good agreement either quantitatively or qualitatively. Further comparisons in other urban areas (eg. Beijing) show that for cases with surface reflectance ratios sufficiently high at the AERONET site, similar over biases can be observed. On the other hand, other cities such as Kanpur, Buenos Aires and Rome do not show any significant bias which can be traced to the fact that these sites are located in regions with less urban surface correlations. Further comparisons in these urban centers are also made with other satellites aerosol retrievals such as POLDER, MISR and OMI.

  17. Applications of Machine Learning in Information Retrieval.

    ERIC Educational Resources Information Center

    Cunningham, Sally Jo; Witten, Ian H.; Littin, James

    1999-01-01

    Introduces the basic ideas that underpin applications of machine learning to information retrieval. Describes applications of machine learning to text categorization. Considers how machine learning can be applied to the query-formulation process. Examines methods of document filtering, where the user specifies a query that is to be applied to an…

  18. Stability of disposal rooms during waste retrieval

    SciTech Connect

    Brandshaug, T.

    1989-03-01

    This report presents the results of a numerical analysis to determine the stability of waste disposal rooms for vertical and horizontal emplacement during the period of waste retrieval. It is assumed that waste retrieval starts 50 years after the initial emplacement of the waste, and that access to and retrieval of the waste containers take place through the disposal rooms. It is further assumed that the disposal rooms are not back-filled. Convective cooling of the disposal rooms in preparation for waste retrieval is included in the analysis. Conditions and parameters used were taken from the Nevada Nuclear Waste Storage Investigation (NNWSI) Project Site Characterization Plan Conceptual Design Report (MacDougall et al., 1987). Thermal results are presented which illustrate the heat transfer response of the rock adjacent to the disposal rooms. Mechanical results are presented which illustrate the predicted distribution of stress, joint slip, and room deformations for the period of time investigated. Under the assumption that the host rock can be classified as ``fair to good`` using the Geomechanics Classification System (Bieniawski, 1974), only light ground support would appear to be necessary for the disposal rooms to remain stable. 23 refs., 28 figs., 2 tabs.

  19. Retrieval-Induced Forgetting: A Developmental Study

    ERIC Educational Resources Information Center

    Ford, Ruth M.; Keating, Sam; Patel, Rina

    2004-01-01

    Two studies examined the possibility of retrieval-induced forgetting by 7-year-olds. Children heard a story while viewing pictures of events mentioned in the story, each highlighting objects drawn from two distinct semantic categories (e.g. animals and food). Over the next several days, children were asked the same yes/no questions about half the…

  20. Chinese Brush Calligraphy Character Retrieval and Learning

    ERIC Educational Resources Information Center

    Zhuang, Yueting; Zhang, Xiafen; Lu, Weiming; Wu, Fei

    2007-01-01

    Chinese brush calligraphy is a valuable civilization legacy and a high art of scholarship. It is still popular in Chinese banners, newspaper mastheads, university names, and celebration gifts. There are Web sites that try to help people enjoy and learn Chinese calligraphy. However, there lacks advanced services such as content-based retrieval or…

  1. A Bayesian Approach to Interactive Retrieval

    ERIC Educational Resources Information Center

    Tague, Jean M.

    1973-01-01

    A probabilistic model for interactive retrieval is presented. Bayesian statistical decision theory principles are applied: use of prior and sample information about the relationship of document descriptions to query relevance; maximization of expected value of a utility function, to the problem of optimally restructuring search strategies in an…

  2. Optical Storage and Retrieval of Library Material.

    ERIC Educational Resources Information Center

    Folen, Doris R.; Stackpole, Laurie E.

    1993-01-01

    Describes the newly installed optical disk storage system at the Naval Research Laboratory's Research Library and Technical Information Center. Planning and design of the system, the conversion of 140,000 reports to optical disk, the information retrieval process, and future plans are covered. (Contains nine references.) (KRN)

  3. BELTracker: evidence sentence retrieval for BEL statements.

    PubMed

    Rastegar-Mojarad, Majid; Komandur Elayavilli, Ravikumar; Liu, Hongfang

    2016-01-01

    Biological expression language (BEL) is one of the main formal representation models of biological networks. The primary source of information for curating biological networks in BEL representation has been literature. It remains a challenge to identify relevant articles and the corresponding evidence statements for curating and validating BEL statements. In this paper, we describe BELTracker, a tool used to retrieve and rank evidence sentences from PubMed abstracts and full-text articles for a given BEL statement (per the 2015 task requirements of BioCreative V BEL Task). The system is comprised of three main components, (i) translation of a given BEL statement to an information retrieval (IR) query, (ii) retrieval of relevant PubMed citations and (iii) finding and ranking the evidence sentences in those citations. BELTracker uses a combination of multiple approaches based on traditional IR, machine learning, and heuristics to accomplish the task. The system identified and ranked at least one fully relevant evidence sentence in the top 10 retrieved sentences for 72 out of 97 BEL statements in the test set. BELTracker achieved a precision of 0.392, 0.532 and 0.615 when evaluated with three criteria, namely full, relaxed and context criteria, respectively, by the task organizers. Our team at Mayo Clinic was the only participant in this task. BELTracker is available as a RESTful API and is available for public use.Database URL: http://www.openbionlp.org:8080/BelTracker/finder/Given_BEL_Statement. PMID:27173525

  4. How to Choose a Media Retrieval System.

    ERIC Educational Resources Information Center

    Huber, Joe

    1995-01-01

    Provides guidelines for schools choosing a media retrieval system. Topics include broadband, baseband, coaxial cable, or fiber optic decisions; the control network; selecting scheduling software; presentation software; device control; control from the classroom; and a comparison of systems offered by five companies. (LRW)

  5. Microwave soil moisture retrieval under trees

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During 2007 a field experiment was conducted with a goal of optimizing microwave soil moisture retrieval algorithms for small to medium deciduous trees. After initial field checkout in Fall 2006, the ComRAD microwave truck instrument system was deployed to a test site with several stands of deciduo...

  6. Artist drawings of the Teleoperator Retrieval System

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A drawing of a Teleoperator Retrieval System (TRS) which is being developed by NASA for use begining in late 1979. This spacecraft is illustrated being used to re-boost the Skylab space station to a higher orbit (23630); A labeled drawing of a TRS which is being developed by NASA (23631).

  7. Telerobotic excavation system for unexploded ordnance retrieval

    SciTech Connect

    Burks, B.L.; Killough, S.M.; Thompson, D.H.; Rossi, R.A.

    1994-12-31

    The small emplacement excavator (SEE) is a ruggedized military vehicle with backhoe and front loader used by the US Army for unexploded ordnance (UXO) retrieval and general utility excavation activities. In order to evaluate the feasibility of removing personnel from the vehicle during high-risk excavation tasks a development and demonstration project was initiated to evaluate performance capabilities of the SEE under telerobotic control. A technology demonstration of the TSEE was conducted at McKinley Range, Redstone Arsenal, Huntsville, Alabama on 13--17 September, 1993. The primary objective of the demonstration was to evaluate and demonstrate the feasibility of remote UXO retrieval. During the demonstration, explosive ordnance disposal specialists were instructed on telerobotic operation of the TSEE, and then were asked to complete a simulated UXO retrieval task. Participants then submitted an evaluation of the system including human factors performance data. This presentation will describe the TSEE, retrieval demonstration, and summarize results of the performance evaluations. Some examples of the results are given below. Seventy percent of the demonstration participants found the tasks were as easy or easier to accomplish utilizing the remote system than with an unmodified system. Similarly, eighty percent of the participants found the TSEE hand controller was as easy or easier to use than the normal manual controls.

  8. Robust keyword retrieval method for OCRed text

    NASA Astrophysics Data System (ADS)

    Fujii, Yusaku; Takebe, Hiroaki; Tanaka, Hiroshi; Hotta, Yoshinobu

    2011-01-01

    Document management systems have become important because of the growing popularity of electronic filing of documents and scanning of books, magazines, manuals, etc., through a scanner or a digital camera, for storage or reading on a PC or an electronic book. Text information acquired by optical character recognition (OCR) is usually added to the electronic documents for document retrieval. Since texts generated by OCR generally include character recognition errors, robust retrieval methods have been introduced to overcome this problem. In this paper, we propose a retrieval method that is robust against both character segmentation and recognition errors. In the proposed method, the insertion of noise characters and dropping of characters in the keyword retrieval enables robustness against character segmentation errors, and character substitution in the keyword of the recognition candidate for each character in OCR or any other character enables robustness against character recognition errors. The recall rate of the proposed method was 15% higher than that of the conventional method. However, the precision rate was 64% lower.

  9. Information Retrieval in Education - A Worthy Tradition?

    ERIC Educational Resources Information Center

    Irving, Ann

    1982-01-01

    Because information handling applies to all forms of learning, one Microelectronics Education Programme (MEP) INSET strategy is devoted to a discussion of the generation, storage, retrieval, communication, and use of information in all subject areas. Discusses the nature of information; MEP and the information domain; information gathering, use,…

  10. Iterative Algorithms for Ptychographic Phase Retrieval

    SciTech Connect

    Yang, Chao; Qian, Jianliang; Schirotzek, Andre; Maia, Filipe; Marchesini, Stefano

    2011-05-03

    Ptychography promises diffraction limited resolution without the need for high resolution lenses. To achieve high resolution one has to solve the phase problem for many partially overlapping frames. Here we review some of the existing methods for solving ptychographic phase retrieval problem from a numerical analysis point of view, and propose alternative methods based on numerical optimization.

  11. Vertical grid of retrieved atmospheric profiles

    NASA Astrophysics Data System (ADS)

    Ceccherini, Simone; Carli, Bruno; Raspollini, Piera

    2016-05-01

    The choice of the vertical grid of atmospheric profiles retrieved from remote sensing observations is discussed considering the two cases of profiles used to represent the results of individual measurements and of profiles used for subsequent data fusion applications. An ozone measurement of the MIPAS instrument is used to assess, for different vertical grids, the quality of the retrieved profiles in terms of profile values, retrieval errors, vertical resolutions and number of degrees of freedom. In the case of individual retrievals no evident advantage is obtained with the use of a grid finer than the one with a reduced number of grid points, which are optimized according to the information content of the observations. Nevertheless, this instrument dependent vertical grid, which seems to extract all the available information, provides very poor results when used for data fusion applications. A loss of about a quarter of the degrees of freedom is observed when the data fusion is made using the instrument dependent vertical grid relative to the data fusion made using a vertical grid optimized for the data fusion product. This result is explained by the analysis of the eigenvalues of the Fisher information matrix and leads to the conclusion that different vertical grids must be adopted when data fusion is the expected application.

  12. Strategies for Building Distributed Information Retrieval Systems.

    ERIC Educational Resources Information Center

    Macleod, Ian A.; And Others

    1987-01-01

    Discussion of the need for distributed information retrieval systems focuses on a model system, Fulcrum FUL/Text. Differences from distributed database management systems are described; system design is discussed; implementation requirements are explained including remote operation calls (ROC's); and a prototype simulation model based on FUL/Text…

  13. Understanding Student Article Retrieval Behaviors: Instructional Implications

    ERIC Educational Resources Information Center

    Cook-Cottone, Catherine P.; Dutt-Doner, Karen; Schoen, David

    2005-01-01

    This study evaluates the use of full-text databases amongst 425 undergraduate and graduate students in western New York. A review of literature implicated convenience, time issues, article retrieval option knowledge, and the appreciation and understanding of research article quality as potential predictors of full-text reliance. These variables…

  14. CALIPSO lidar ratio retrieval over the ocean.

    PubMed

    Josset, Damien; Rogers, Raymond; Pelon, Jacques; Hu, Yongxiang; Liu, Zhaoyan; Omar, Ali; Zhai, Peng-Wang

    2011-09-12

    We are demonstrating on a few cases the capability of CALIPSO to retrieve the 532 nm lidar ratio over the ocean when CloudSat surface scattering cross section is used as a constraint. We are presenting the algorithm used and comparisons with the column lidar ratio retrieved by the NASA airborne high spectral resolution lidar. For the three cases presented here, the agreement is fairly good. The average CALIPSO 532 nm column lidar ratio bias is 13.7% relative to HSRL, and the relative standard deviation is 13.6%. Considering the natural variability of aerosol microphysical properties, this level of accuracy is significant since the lidar ratio is a good indicator of aerosol types. We are discussing dependencies of the accuracy of retrieved aerosol lidar ratio on atmospheric aerosol homogeneity, lidar signal to noise ratio, and errors in the optical depth retrievals. We are obtaining the best result (bias 7% and standard deviation around 6%) for a nighttime case with a relatively constant lidar ratio (in the vertical) indicative of homogeneous aerosol type.

  15. Neural Network Model of Memory Retrieval

    PubMed Central

    Recanatesi, Stefano; Katkov, Mikhail; Romani, Sandro; Tsodyks, Misha

    2015-01-01

    Human memory can store large amount of information. Nevertheless, recalling is often a challenging task. In a classical free recall paradigm, where participants are asked to repeat a briefly presented list of words, people make mistakes for lists as short as 5 words. We present a model for memory retrieval based on a Hopfield neural network where transition between items are determined by similarities in their long-term memory representations. Meanfield analysis of the model reveals stable states of the network corresponding (1) to single memory representations and (2) intersection between memory representations. We show that oscillating feedback inhibition in the presence of noise induces transitions between these states triggering the retrieval of different memories. The network dynamics qualitatively predicts the distribution of time intervals required to recall new memory items observed in experiments. It shows that items having larger number of neurons in their representation are statistically easier to recall and reveals possible bottlenecks in our ability of retrieving memories. Overall, we propose a neural network model of information retrieval broadly compatible with experimental observations and is consistent with our recent graphical model (Romani et al., 2013). PMID:26732491

  16. Retrieval-Induced Forgetting of Arithmetic Facts

    ERIC Educational Resources Information Center

    Campbell, Jamie I. D.; Thompson, Valerie A.

    2012-01-01

    Retrieval-induced forgetting (RIF) is a widely studied phenomenon of human memory, but RIF of arithmetic facts remains relatively unexplored. In 2 experiments, we investigated RIF of simple addition facts (2 + 3 = 5) from practice of their multiplication counterparts (2 x 3 = 6). In both experiments, robust RIF expressed in response times occurred…

  17. 3D object retrieval using salient views

    PubMed Central

    Shapiro, Linda G.

    2013-01-01

    This paper presents a method for selecting salient 2D views to describe 3D objects for the purpose of retrieval. The views are obtained by first identifying salient points via a learning approach that uses shape characteristics of the 3D points (Atmosukarto and Shapiro in International workshop on structural, syntactic, and statistical pattern recognition, 2008; Atmosukarto and Shapiro in ACM multimedia information retrieval, 2008). The salient views are selected by choosing views with multiple salient points on the silhouette of the object. Silhouette-based similarity measures from Chen et al. (Comput Graph Forum 22(3):223–232, 2003) are then used to calculate the similarity between two 3D objects. Retrieval experiments were performed on three datasets: the Heads dataset, the SHREC2008 dataset, and the Princeton dataset. Experimental results show that the retrieval results using the salient views are comparable to the existing light field descriptor method (Chen et al. in Comput Graph Forum 22(3):223–232, 2003), and our method achieves a 15-fold speedup in the feature extraction computation time. PMID:23833704

  18. BELTracker: evidence sentence retrieval for BEL statements

    PubMed Central

    Rastegar-Mojarad, Majid; Komandur Elayavilli, Ravikumar; Liu, Hongfang

    2016-01-01

    Biological expression language (BEL) is one of the main formal representation models of biological networks. The primary source of information for curating biological networks in BEL representation has been literature. It remains a challenge to identify relevant articles and the corresponding evidence statements for curating and validating BEL statements. In this paper, we describe BELTracker, a tool used to retrieve and rank evidence sentences from PubMed abstracts and full-text articles for a given BEL statement (per the 2015 task requirements of BioCreative V BEL Task). The system is comprised of three main components, (i) translation of a given BEL statement to an information retrieval (IR) query, (ii) retrieval of relevant PubMed citations and (iii) finding and ranking the evidence sentences in those citations. BELTracker uses a combination of multiple approaches based on traditional IR, machine learning, and heuristics to accomplish the task. The system identified and ranked at least one fully relevant evidence sentence in the top 10 retrieved sentences for 72 out of 97 BEL statements in the test set. BELTracker achieved a precision of 0.392, 0.532 and 0.615 when evaluated with three criteria, namely full, relaxed and context criteria, respectively, by the task organizers. Our team at Mayo Clinic was the only participant in this task. BELTracker is available as a RESTful API and is available for public use. Database URL: http://www.openbionlp.org:8080/BelTracker/finder/Given_BEL_Statement PMID:27173525

  19. Guidelines for Teachers of Online Information Retrieval.

    ERIC Educational Resources Information Center

    Wood, F. E.

    These guidelines are intended to provide realistic and practical guidance about the options available to teachers and planners of education and training programs wholly or partly concerned with online information retrieval, particularly those in academic departments of library and information studies. Seven sections address: (1) the aims and scope…

  20. Introduction to Data Transmission for Information Retrieval

    ERIC Educational Resources Information Center

    Kallenbach, P. A.

    1975-01-01

    An introduction is presented to data transmission technology and networks for information retrieval purposes. Data signals are analyzed, modulation techniques are discussed, communication procedures between terminals and the central processing unit are surveyed, and possible network configurations are considered. (Author/PF)

  1. Introduction and Overview: Visualization, Retrieval, and Knowledge.

    ERIC Educational Resources Information Center

    Rorvig, Mark; Lunin, Lois F.

    1999-01-01

    Describes this perspectives issue that was designed to provide an historical background to visualization in information retrieval. Topics include knowledge, digital technology, the first visual interface to a collection at NASA (National Aeronautics and Space Administration), theoretical foundations, and applications. (LRW)

  2. Retrieval-induced forgetting in schizophrenia

    PubMed Central

    Nestor, Paul G.; Piech, Richard; Allen, Christopher; Niznikiewicz, Margaret; Shenton, Martha; McCarley, Robert W.

    2009-01-01

    Retrieving category associates (e.g., FRUIT-ORANGE) may induce forgetting other category members (e.g., FRUIT-BANANA), a phenomenon known as retrieval-induced forgetting (RIF). We designed 2 experiments to examine the role of RIF in the associative memory impairment of schizophrenia (SZ). Subjects studied 36 category-exemplar pairs, generated from 6 categories composed of 6 members each. For half of the studied category-exemplar pairs, subjects practiced retrieval by completing word stems, followed by a delayed category-cued recall on all of the practiced and unpracticed items. Experiment 1 used unrelated category exemplars-pairs (e.g., FRUIT-ORANGE, METALS-IRON), whereas experiment 2 included related category exemplar pairs (e.g., COTTON-SHIRT, LEATHER-SKIRT). SZ showed reduced associative memory but normal RIF for unrelated categories used in experiment 1. For experiment 2, SZ showed a significant decline in associative memory for related but not unrelated category-exemplars in comparison to controls. Results suggested faulty specificity/distinctiveness for encoding and retrieval, but not abnormal RIF in the associative memory disturbance of SZ. PMID:15885511

  3. Third LDEF Post-Retrieval Symposium Abstracts

    NASA Technical Reports Server (NTRS)

    Levine, Arlene S. (Compiler)

    1993-01-01

    This volume is a compilation of abstracts submitted to the Third Long Duration Exposure Facility (LDEF) Post-Retrieval Symposium. The abstracts represent the data analysis of the 57 experiments flown on the LDEF. The experiments include materials, coatings, thermal systems, power and propulsion, science (cosmic ray, interstellar gas, heavy ions, micrometeoroid, etc.), electronics, optics, and life science.

  4. Body Posture Facilitates Retrieval of Autobiographical Memories

    ERIC Educational Resources Information Center

    Dijkstra, Katinka; Kaschak, Michael P.; Zwaan, Rolf A.

    2007-01-01

    We assessed potential facilitation of congruent body posture on access to and retention of autobiographical memories in younger and older adults. Response times were shorter when body positions during prompted retrieval of autobiographical events were similar to the body positions in the original events than when body position was incongruent.…

  5. Knowledge Discovery in Spatial Cartographic Information Retrieval.

    ERIC Educational Resources Information Center

    Yu, Lixin

    1999-01-01

    Describes a prototype system--GeoMatch--that allows users to interactively define geographic areas of interest on a background map and to define, qualitatively or quantitatively, the relationship between the user-defined area and the map coverage. The knowledge discovery in database (KDD) factor is analyzed in the retrieval process. The MARC…

  6. AEROMETRIC INFORMATION RETRIEVAL SYSTEM (AIRS) - GRAPHICS

    EPA Science Inventory

    Aerometric Information Retrieval System (AIRS) is a computer-based repository of information about airborne pollution in the United States and various World Health Organization (WHO) member countries. AIRS is administered by the U.S. Environmental Protection Agency, and runs on t...

  7. Microcomputers for Information Storage and Retrieval.

    ERIC Educational Resources Information Center

    Kanters, Ben

    1983-01-01

    Report on use of the microcomputer for information storage and retrieval (ISR) notes hardware (floppy disks, keyboard, screen, printer); functions of ISR software; standardization of the operating system; database creation; data entry; indexing; search process; choice of ISR software package; software market and user; training and instruction; and…

  8. IMIRSEL: a secure music retrieval testing environment

    NASA Astrophysics Data System (ADS)

    Downie, John S.

    2004-10-01

    The Music Information Retrieval (MIR) and Music Digital Library (MDL) research communities have long noted the need for formal evaluation mechanisms. Issues concerning the unavailability of freely-available music materials have greatly hindered the creation of standardized test collections with which these communities could scientifically assess the strengths and weaknesses of their various music retrieval techniques. The International Music Information Retrieval Systems Evaluation Laboratory (IMIRSEL) is being developed at the University of Illinois at Urbana-Champaign (UIUC) specifically to overcome this hindrance to the scientific evaluation of MIR/MDL systems. Together with its subsidiary Human Use of Music Information Retrieval Systems (HUMIRS) project, IMIRSEL will allow MIR/MDL researchers access to the standardized large-scale collection of copyright-sensitive music materials and standardized test queries being housed at UIUC's National Center for Supercomputing Applications (NCSA). Virtual Research Labs (VRL), based upon NCSA's Data-to-Knowledge (D2K) tool set, are being developed through which MIR/MDL researchers will interact with the music materials under a "trusted code" security model.

  9. Teaching a Heuristic Approach to Information Retrieval.

    ERIC Educational Resources Information Center

    Ury, Connie Jo; And Others

    1997-01-01

    Discusses lifelong learning and the need for information retrieval skills, and describes how Northwest Missouri State University incorporates a heuristic model of library instruction in which students continually evaluate and refine information-seeking practices while progressing through all levels of courses in diverse disciplines. (Author/LRW)

  10. The JPL Library information retrieval system

    NASA Technical Reports Server (NTRS)

    Walsh, J.

    1975-01-01

    The development, capabilities, and products of the computer-based retrieval system of the Jet Propulsion Laboratory Library are described. The system handles books and documents, produces a book catalog, and provides a machine search capability. Programs and documentation are available to the public through NASA's computer software dissemination program.

  11. Neural Network Model of Memory Retrieval.

    PubMed

    Recanatesi, Stefano; Katkov, Mikhail; Romani, Sandro; Tsodyks, Misha

    2015-01-01

    Human memory can store large amount of information. Nevertheless, recalling is often a challenging task. In a classical free recall paradigm, where participants are asked to repeat a briefly presented list of words, people make mistakes for lists as short as 5 words. We present a model for memory retrieval based on a Hopfield neural network where transition between items are determined by similarities in their long-term memory representations. Meanfield analysis of the model reveals stable states of the network corresponding (1) to single memory representations and (2) intersection between memory representations. We show that oscillating feedback inhibition in the presence of noise induces transitions between these states triggering the retrieval of different memories. The network dynamics qualitatively predicts the distribution of time intervals required to recall new memory items observed in experiments. It shows that items having larger number of neurons in their representation are statistically easier to recall and reveals possible bottlenecks in our ability of retrieving memories. Overall, we propose a neural network model of information retrieval broadly compatible with experimental observations and is consistent with our recent graphical model (Romani et al., 2013). PMID:26732491

  12. Bucknell Automated Retrieval and Display System.

    ERIC Educational Resources Information Center

    Rivoire, Helena; Lozoski, Laurene

    This report describes the development and operation of BARDS, the Bucknell Automated Retrieval and Display System, an online bibliographic access system for a selected section of the collection at the Ellen Clarke Bertrand Library. This system was used by the Bucknell University community from June 1974 through January 1975; further development…

  13. A User Interface for Multiple Retrieval Systems.

    ERIC Educational Resources Information Center

    Teskey, Niall; And Others

    1987-01-01

    Reviews current systems designed to help end-users search online databases without the assistance of an intermediary and describes a prototype system which emulates the Deco (the text storage and retrieval system used by Unilever) interface on Dialog and Data-Star. Initial trials of the prototype system are reported. (15 references) (MES)

  14. Retrieval and classification of dental research articles.

    PubMed

    Bartling, W C; Schleyer, T K; Visweswaran, S

    2003-12-01

    Successful retrieval of a corpus of literature on a broad topic can be difficult. This study demonstrates a method to retrieve the dental and craniofacial research literature. We explored MeSH manually for dental or craniofacial indexing terms. MEDLINE was searched using these terms, and a random sample of references was extracted from the resulting set. Sixteen dental research experts categorized these articles, reading only the title and abstract, as either: (1) dental research, (2) dental non-research, (3) non-dental, or (4) not sure. Identify Patient Sets (IPS), a probabilistic text classifier, created models, based on the presence or absence of words or UMLS phrases, that distinguished dental research articles from all others. These models were applied to a test set with different inputs for each article: (1) title and abstract only, (2) MeSH terms only, or (3) both. By title and abstract only, IPS correctly classified 64% of all dental research articles present in the test set. The percentage of correctly classified dental research articles in this retrieved set was 71%. MeSH term inclusion decreased performance. Computer programs that use text input to categorize articles may aid in retrieval of a broad corpus of literature better than indexing terms or key words alone.

  15. Prediction During Learning of Later Retrievability.

    ERIC Educational Resources Information Center

    Lovelace, Eugene A.

    Evidence was found for an ability to monitor during learning the degree of retrievability of the to-be-learned material from memory at time of a subsequent test. Students were given three successive study trials to learn either a list of 60 paired associates or a free-recall list of 60 "unrelated" words. During a fourth study trial, they rated on…

  16. Bullet retrieval in the operating room.

    PubMed

    Hanshaw, S L

    1994-10-01

    Valuable trace evidence is often lost or destroyed because of faulty collection and preservation techniques during surgical management of gunshot wounds. An experiment was conducted to show the importance of proper collection techniques and preservation of forensic evidence. Results are noted, a discussion is given, and a protocol for the surgical retrieval of bullets is presented.

  17. Retrievals with the Infrared Atmospheric Sounding Interferometer

    NASA Technical Reports Server (NTRS)

    Zhou, Daniel K.; Liu, Xu; Larar, Allen M.; Smith, William L.; Taylor, Jonathan P.; Schlussel, Peter; Strow, L. Larrabee; Calbet, Xavier; Mango, Stephen A.

    2007-01-01

    The Infrared Atmospheric Sounding Interferometer (IASI) on the MetOp satellite was launched on October 19, 2006. The Joint Airborne IASI Validation Experiment (JAIVEx) was conducted during April 2007 mainly for validation of the IASI on the MetOp satellite. IASI possesses an ultra-spectral resolution of 0.25/cm and a spectral coverage from 645 to 2760/cm. Ultraspectral resolution infrared spectral radiance obtained from near nadir observations provide atmospheric, surface, and cloud property information. An advanced retrieval algorithm with a fast radiative transfer model, including cloud effects, is used for atmospheric profile and cloud parameter retrieval. Preliminary retrievals of atmospheric soundings, surface properties, and cloud optical/microphysical properties with the IASI observations during the JAIVEx are obtained and presented. These retrievals are further inter-compared with those obtained from airborne FTS system, such as the NPOESS Airborne Sounder Testbed Interferometer (NAST-I), dedicated dropsondes, radiosondes, and ground based Raman Lidar. The capabilities of satellite ultra-spectral sounder such as the IASI are investigated.

  18. Encoding and Retrieval During Bimanual Rhythmic Coordination

    ERIC Educational Resources Information Center

    Shockley, Kevin; Turvey, Michael T.

    2005-01-01

    In 2 experiments, bimanual 1:1 rhythmic coordination was performed concurrently with encoding or retrieval of word lists. Effects of divided attention (DA) on coordination were indexed by changes in mean relative phase and recurrence measures of shared activity between the 2 limbs. Effects of DA on memory were indexed by deficits in recall…

  19. Identify, Organize, and Retrieve Items Using Zotero

    ERIC Educational Resources Information Center

    Clark, Brian; Stierman, John

    2009-01-01

    Librarians build collections. To do this they use tools that help them identify, organize, and retrieve items for the collection. Zotero (zoh-TAIR-oh) is such a tool that helps the user build a library of useful books, articles, web sites, blogs, etc., discovered while surfing online. A visit to Zotero's homepage, www.zotero.org, shows a number of…

  20. Using Projects To Teach Information Retrieval.

    ERIC Educational Resources Information Center

    Pode, Adam

    2001-01-01

    Discusses the approach of using student projects to teach information retrieval. Examines projects completed by students at Mercyhurst College (Erie, Pennsylvania), and includes examples of their work. Discusses problems encountered, weaknesses exposed, and strengths of the project genre overall. Other issues raised include methods for reinforcing…

  1. Dual-Retrieval Models and Neurocognitive Impairment

    ERIC Educational Resources Information Center

    Brainerd, C. J.; Reyna, V. F.; Gomes, C. F. A.; Kenney, A. E.; Gross, C. J.; Taub, E. S.; Spreng, R. N.

    2014-01-01

    Advances in dual-retrieval models of recall make it possible to use clinical data to test theoretical hypotheses about mild cognitive impairment (MCI) and Alzheimer's dementia (AD), the most common forms of neurocognitive impairment. Hypotheses about the nature of the episodic memory declines in these diseases, about decline versus sparing of…

  2. Methods of Cost Reduction in Information Retrieval.

    ERIC Educational Resources Information Center

    Wilmoth, James Noel

    Cost effectiveness of the QUERY program for searching the Educational Resources Information Center (ERIC) data base has been an important issue at Auburn University. At least two broad categories of costs are associated with information retrieval from a data base such as ERIC: fixed costs or overhead and data base associated costs. The concern at…

  3. Knowledge Retrieval through Virtual Communities of Practice

    ERIC Educational Resources Information Center

    Gammelgaard, Jens

    2010-01-01

    This article explores how Computer Sciences Corporation (CSC) manages knowledge retrieval by employees when they need to access documents written by colleagues in geographically distant units. CSC's establishment of virtual communities of practice facilitates the coordination of knowledge, and minimises contextual gaps between senders and…

  4. The Pragmatics of Information Retrieval Experimentation, Revisited.

    ERIC Educational Resources Information Center

    Tague-Sutcliffe, Jean

    1992-01-01

    This overview of the research process for the novice information retrieval (IR) researcher provides guidance on selecting a research question, choosing the type of test, defining variables, developing or using databases, finding and processing queries, assigning treatments to experimental units, collecting and analyzing the data, and presenting…

  5. Retrieval and the extinction of memory.

    PubMed

    Cammarota, Martín; Bevilaqua, Lia R M; Barros, Daniela M; Vianna, Mônica R M; Izquierdo, Luciana A; Medina, Jorge H; Izquierdo, Iván

    2005-06-01

    1. Memory is assessed by measuring retrieval which is often elicited by the solely presentation of the conditioned stimulus (CS). However, as known since Pavlov, presentation of the CS alone generates extinction. 2. One-trial avoidance (IA) is a much used conditioned fear paradigm in which the CS is the safe part of a training apparatus, the unconditioned stimulus (US) is a footshock and the conditioned response (CR) is to stay in the safe area. Retrieval of the memory for the step-down version of this task is measured in the absence of the US, as latency to step-down from the safe area (i.e., a platform). 3. Extinction of the IA response is installed at the moment of the first non-reinforced test session, as clearly shown by the fact that many drugs, including PKA, ERK and protein synthesis inhibitors as well as NMDA receptor antagonists, hinder extinction when infused into the hippocampus or the basolateral amygdala at the moment of the first test session but not later. 4. Some, but not all the molecular systems required for extinction are also activated by retrieval, further endorsing the hypothesis that although retrieval is necessary for the generation of extinction this last process constitutes a new learning secondary to the non-reinforced expression of the original trace.

  6. Interpolation of the Extended Boolean Retrieval Model.

    ERIC Educational Resources Information Center

    Zanger, Daniel Z.

    2002-01-01

    Presents an interpolation theorem for an extended Boolean information retrieval model. Results show that whenever two or more documents are similarly ranked at any two points for a query containing exactly two terms, then they are similarly ranked at all points in between; and that results can fail for queries with more than two terms. (Author/LRW)

  7. A Context Vector Model for Information Retrieval.

    ERIC Educational Resources Information Center

    Billhardt, Holger; Borrajo, Daniel; Maojo, Victor

    2002-01-01

    Presents an indexing and information retrieval method that, based on the vector space model, incorporates term dependencies and thus obtains semantically richer representations of documents. Highlights include term context vectors; techniques for estimating the dependencies among terms; term weights; experimental results on four text collections;…

  8. Video and image retrieval beyond the cognitive level: the needs and possibilities

    NASA Astrophysics Data System (ADS)

    Hanjalic, Alan

    2000-12-01

    The worldwide research efforts in the are of image and video retrieval have concentrated so far on increasing the efficiency and reliability of extracting the elements of image and video semantics and so on improving the search and retrieval performance at the cognitive level of content abstraction. At this abstraction level, the user is searching for 'factual' or 'objective' content such as image showing a panorama of San Francisco, an outdoor or an indoor image, a broadcast news report on a defined topic, a movie dialog between the actors A and B or the parts of a basketball game showing fast breaks, steals and scores. These efforts, however, do not address the retrieval applications at the so-called affective level of content abstraction where the 'ground truth' is not strictly defined. Such applications are, for instance, those where subjectivity of the user plays the major role, e.g. the task of retrieving all images that the user 'likes most', and those that are based on 'recognizing emotions' in audiovisual data. Typical examples are searching for all images that 'radiate happiness', identifying all 'sad' movie fragments and looking for the 'romantic landscapes', 'sentimental' movie segments, 'movie highlights' or 'most exciting' moments of a sport event. This paper discusses the needs and possibilities for widening the current scope of research in the area of image and video search and retrieval in order to enable applications at the affective level of content abstraction.

  9. Video and image retrieval beyond the cognitive level: the needs and possibilities

    NASA Astrophysics Data System (ADS)

    Hanjalic, Alan

    2001-01-01

    The worldwide research efforts in the are of image and video retrieval have concentrated so far on increasing the efficiency and reliability of extracting the elements of image and video semantics and so on improving the search and retrieval performance at the cognitive level of content abstraction. At this abstraction level, the user is searching for 'factual' or 'objective' content such as image showing a panorama of San Francisco, an outdoor or an indoor image, a broadcast news report on a defined topic, a movie dialog between the actors A and B or the parts of a basketball game showing fast breaks, steals and scores. These efforts, however, do not address the retrieval applications at the so-called affective level of content abstraction where the 'ground truth' is not strictly defined. Such applications are, for instance, those where subjectivity of the user plays the major role, e.g. the task of retrieving all images that the user 'likes most', and those that are based on 'recognizing emotions' in audiovisual data. Typical examples are searching for all images that 'radiate happiness', identifying all 'sad' movie fragments and looking for the 'romantic landscapes', 'sentimental' movie segments, 'movie highlights' or 'most exciting' moments of a sport event. This paper discusses the needs and possibilities for widening the current scope of research in the area of image and video search and retrieval in order to enable applications at the affective level of content abstraction.

  10. The iTRAPs: Guardians of Synaptic Vesicle Cargo Retrieval During Endocytosis.

    PubMed

    Gordon, Sarah L; Cousin, Michael A

    2016-01-01

    The reformation of synaptic vesicles (SVs) during endocytosis is essential for the maintenance of neurotransmission in central nerve terminals. Newly formed SVs must be generated with the correct protein cargo in the correct stoichiometry to be functional for exocytosis. Classical clathrin adaptor protein complexes play a key role in sorting and clustering synaptic vesicle cargo in this regard. However it is becoming increasingly apparent that additional "fail-safe" mechanisms exist to ensure the accurate retrieval of essential cargo molecules. For example, the monomeric adaptor proteins AP180/CALM and stonin-2 are required for the efficient retrieval of synaptobrevin II (sybII) and synaptotagmin-1 respectively. Furthermore, recent studies have revealed that sybII and synaptotagmin-1 interact with other SV cargoes to ensure a high fidelity of retrieval. These cargoes are synaptophysin (for sybII) and SV2A (for synaptotagmin-1). In this review, we summarize current knowledge regarding the retrieval mechanisms for both sybII and synaptotagmin-1 during endocytosis. We also define and set criteria for a new functional group of SV molecules that facilitate the retrieval of their interaction partners. We have termed these molecules intrinsic trafficking partners (iTRAPs) and we discuss how the function of this group impacts on presynaptic performance in both health and disease.

  11. The iTRAPs: Guardians of Synaptic Vesicle Cargo Retrieval During Endocytosis

    PubMed Central

    Gordon, Sarah L.; Cousin, Michael A.

    2016-01-01

    The reformation of synaptic vesicles (SVs) during endocytosis is essential for the maintenance of neurotransmission in central nerve terminals. Newly formed SVs must be generated with the correct protein cargo in the correct stoichiometry to be functional for exocytosis. Classical clathrin adaptor protein complexes play a key role in sorting and clustering synaptic vesicle cargo in this regard. However it is becoming increasingly apparent that additional “fail-safe” mechanisms exist to ensure the accurate retrieval of essential cargo molecules. For example, the monomeric adaptor proteins AP180/CALM and stonin-2 are required for the efficient retrieval of synaptobrevin II (sybII) and synaptotagmin-1 respectively. Furthermore, recent studies have revealed that sybII and synaptotagmin-1 interact with other SV cargoes to ensure a high fidelity of retrieval. These cargoes are synaptophysin (for sybII) and SV2A (for synaptotagmin-1). In this review, we summarize current knowledge regarding the retrieval mechanisms for both sybII and synaptotagmin-1 during endocytosis. We also define and set criteria for a new functional group of SV molecules that facilitate the retrieval of their interaction partners. We have termed these molecules intrinsic trafficking partners (iTRAPs) and we discuss how the function of this group impacts on presynaptic performance in both health and disease. PMID:26903854

  12. Innovative systems for mixed waste retrieval and/or treatment in confined spaces

    SciTech Connect

    Fekete, L.J.; Ghusn, A.E.

    1993-03-01

    Fernald established operations in 1951 and produced uranium and other metals for use at other DOE facilities. A part of the sitewide remediation effort is the removal, treatment, and disposal of the K-65 wastes from Silos 1 and 2. These silos contain radium-bearing residues from the processing of pitchblende ore. An Engineering Evaluation/Cost Analysis was prepared to evaluate the removal action alternatives using the preliminary characterization data and select a preferred alternative. The selected alternative consisted of covering the K-65 residues and the silo dome. The remediation of the K-65 wastes consists of the retrieval and treatment of the wastes prior to final disposal, which has not yet been determined. Treatment will be performed in a new facility to be built adjacent to the silos. The wastes must be retrieved from silos in an efficient and reliable way and delivered to the treatment facility. The first challenge of covering the wastes with bentonite has been successfully met. The second phase of retrieving the wastes from the silos is not due for a few years. However, conceptual design and configuration of the retrieval system have been developed as part of the Conceptual Design Report. The system is based on the utilization of hydraulic mining techniques, and is based on similar successful applications. This report describes the emplacement of the bentonite grant and the design for the slurry retrieval system.

  13. High-efficiency x-ray gratings with asymmetric-cut multilayers.

    PubMed

    Bajt, Saša; Chapman, Henry N; Aquila, Andrew; Gullikson, Eric

    2012-03-01

    We present the fabrication and analysis of efficient and highly dispersive gratings for the x-ray and extreme ultraviolet (EUV) regime. We show that an asymmetric-cut multilayer structure can act as a near-perfect blazed grating. The precision and high line density are achieved by layer deposition of materials, which can be controlled to the angstrom level. We demonstrate this in the EUV regime with two structures made by cutting and polishing magnetron-sputtered multilayer mirrors of over 2000 bilayers thick, each with a period of 6.88 nm. These were cut at angles of 2.9° and 7.8° to the surface. Within the 3% bandwidth rocking curve of the multilayer, the angular dispersion of the diffracted wave was in agreement with the grating equation for elements with 7250 and 19,700 line pairs/mm, respectively. The dependence of the measured efficiency was in excellent agreement with a formulation of dynamical diffraction theory for multilayered structures. At a wavelength of 13.2 nm, the efficiency of the first-order diffraction was over 95% of the reflectivity of the uncut multilayer. We predict that such structures should also be effective at shorter x-ray wavelengths. Both the Laue (transmitting) and Bragg (reflecting) geometries are incorporated in our formalism, which is applied to the analysis of multilayer Laue lenses and focusing and dispersing Bragg optics. PMID:22472750

  14. Waste Emplacement/Retrieval System Description Document

    SciTech Connect

    Eric Loros

    2001-07-25

    The Waste Emplacement/Retrieval System transports Waste Packages (WPs) from the Waste Handling Building (WHB) to the subsurface area of emplacement, and emplaces the WPs once there. The Waste Emplacement/Retrieval System also, if necessary, removes some or all of the WPs from the underground and transports them to the surface. Lastly, the system is designed to remediate abnormal events involving the portions of the system supporting emplacement or retrieval. During emplacement operations, the system operates on the surface between the WHB and North Portal, and in the subsurface in the North Ramp, access mains, and emplacement drifts. During retrieval or abnormal conditions, the operations areas may also extend to a surface retrieval storage site and South Portal on the surface, and the South Ramp in the subsurface. A typical transport and emplacement operation involves the following sequence of events. A WP is loaded into a WP transporter at the WHB, and coupled to a pair of transport locomotives. The locomotives transport the WP from the WHB, down the North Ramp, and to the entrance of an emplacement drift. Once docked at the entrance of the emplacement drift, the WP is moved outside of the WP transporter, and engaged by a WP emplacement gantry. The WP emplacement gantry lifts the WP, and transports it to its emplacement location, where the WP is then lowered to its final resting position. The WP emplacement gantry remains in the drift while the WP transporter is returned to the WHB by the locomotives. When the transporter reaches the WHB, the sequence of operations is repeated. Retrieval of all the WPs, or a large group of WPs, under normal conditions is achieved by reversing the emplacement operations. Retrieval of a small set of WPs, under normal or abnormal conditions, is known as recovery. Recovery performed under abnormal conditions will involve a suite of specialized equipment designed to perform a variety of tasks to enable the recovery process. Recovery

  15. Regularization for Atmospheric Temperature Retrieval Problems

    NASA Technical Reports Server (NTRS)

    Velez-Reyes, Miguel; Galarza-Galarza, Ruben

    1997-01-01

    Passive remote sensing of the atmosphere is used to determine the atmospheric state. A radiometer measures microwave emissions from earth's atmosphere and surface. The radiance measured by the radiometer is proportional to the brightness temperature. This brightness temperature can be used to estimate atmospheric parameters such as temperature and water vapor content. These quantities are of primary importance for different applications in meteorology, oceanography, and geophysical sciences. Depending on the range in the electromagnetic spectrum being measured by the radiometer and the atmospheric quantities to be estimated, the retrieval or inverse problem of determining atmospheric parameters from brightness temperature might be linear or nonlinear. In most applications, the retrieval problem requires the inversion of a Fredholm integral equation of the first kind making this an ill-posed problem. The numerical solution of the retrieval problem requires the transformation of the continuous problem into a discrete problem. The ill-posedness of the continuous problem translates into ill-conditioning or ill-posedness of the discrete problem. Regularization methods are used to convert the ill-posed problem into a well-posed one. In this paper, we present some results of our work in applying different regularization techniques to atmospheric temperature retrievals using brightness temperatures measured with the SSM/T-1 sensor. Simulation results are presented which show the potential of these techniques to improve temperature retrievals. In particular, no statistical assumptions are needed and the algorithms were capable of correctly estimating the temperature profile corner at the tropopause independent of the initial guess.

  16. Remote technologies for buried waste retrieval

    SciTech Connect

    Smith, A.M.; Rice, P.

    1995-10-01

    The DOE is evaluating what should be done with this buried waste. Although the radioactive waste is not particularly mobile unless airborne, some of it was buried with volatile organics and/or other substances that tend to spread easily to surrounding soil or water tables. Volatile organics are hazardous materials (such as trichloroethylene) and require clean-up at certain levels in drinking water. There is concern that the buried volatile organics will spread into the water table and contaminate drinking water. Because of this, the DOE is considering options for handling this buried waste and reducing the risks of spreading or exposure. There are two primary options: containment and stabilization, or retrieval. Containment and stabilization systems would include systems that would leave the waste where it is, but contain and stabilize it so that the radioactive and hazardous materials would not spread to the surrounding soil, water, or air. For example, an in situ vitrification system could be used to melt the waste into a composite glass-like material that would not leach into the surrounding soil, water, or air. Retrieval systems are those that would remove the waste from its burial location for treatment and/or repackaging for long term storage. The objective of this project was to develop and demonstrate remote technologies that would minimize dust generation and the spread of airborne contaminants during buried waste retrieval. Remote technologies are essential for the retrieval of buried waste because they remove workers from the hazardous environment and provide greater automation, reducing the chances of human error. Minimizing dust generation is also essential to increased safety for the workers and the environment during buried waste retrieval. The main contaminants within the waste are micron-sized particles of plutonium and americium oxides, chlorides, and hydroxides, which are easily suspended in air and spread if disturbed.

  17. Final report for the cryogenic retrieval demonstration

    SciTech Connect

    Valentich, D.J.; Yokuda, E.L.

    1992-09-01

    This report documents a demonstration of a proposed buried transuranic waste retrieval concept that uses cryogenic ground freezing and remote excavation. At the Idaho National Engineering Laboratory (INEL), there are over 8 million ft{sup 3} of intermingled soil and transuranic (TRU) wastes in shallow land burial, and retrieval of the material is one of the options being considered by the Buried Waste Integrated Demonstration for the Environmental Restoration program. Cryogenically freezing contaminated soil and buried waste has been proposed as a way to greatly reduce or eliminate the climate the threat of contamination spread during retrieval activities. In support of this idea, a demonstration of an innovative ground freezing and retrieval technology was performed at the INEL. This initial demonstration was held near the Radioactive Waste Management Complex at a ``cold test pit`` that was built in 1988 as a test bed for the demonstration of retrieval contamination control technologies. This pit is not contaminated with any radioactive or hazardous wastes. Barrels and boxes filled with metals, plastics, tools, paper, cloth, etc. configured in the same manner as expected in contaminated pits and trenches are buried at the cold test pit. After design, fabrication, and shop testing, Sonsub mobilized to the field in early July 1992 to perform the field demonstration. It was planned to freeze and extract four pits, each 9 {times} 9 {times} 10 ft. Each pit represented a different configuration of buried waste (stacked boxes, stacked barrels, random dumped barrels and boxes, and random dumped barrels). Sonsub`s proposed technology consisted of driving a series of freeze pipes into the soil and waste, using liquid nitrogen to freeze the mass, and extracting the soil and debris using a series of remote operated, bridge crane mounted tools. In conjunction with the freezing and removal activities, temperature and moisture measurements, and air monitoring were performed.

  18. Final report for the cryogenic retrieval demonstration

    SciTech Connect

    Valentich, D.J.; Yokuda, E.L.

    1992-09-01

    This report documents a demonstration of a proposed buried transuranic waste retrieval concept that uses cryogenic ground freezing and remote excavation. At the Idaho National Engineering Laboratory (INEL), there are over 8 million ft[sup 3] of intermingled soil and transuranic (TRU) wastes in shallow land burial, and retrieval of the material is one of the options being considered by the Buried Waste Integrated Demonstration for the Environmental Restoration program. Cryogenically freezing contaminated soil and buried waste has been proposed as a way to greatly reduce or eliminate the climate the threat of contamination spread during retrieval activities. In support of this idea, a demonstration of an innovative ground freezing and retrieval technology was performed at the INEL. This initial demonstration was held near the Radioactive Waste Management Complex at a cold test pit'' that was built in 1988 as a test bed for the demonstration of retrieval contamination control technologies. This pit is not contaminated with any radioactive or hazardous wastes. Barrels and boxes filled with metals, plastics, tools, paper, cloth, etc. configured in the same manner as expected in contaminated pits and trenches are buried at the cold test pit. After design, fabrication, and shop testing, Sonsub mobilized to the field in early July 1992 to perform the field demonstration. It was planned to freeze and extract four pits, each 9 [times] 9 [times] 10 ft. Each pit represented a different configuration of buried waste (stacked boxes, stacked barrels, random dumped barrels and boxes, and random dumped barrels). Sonsub's proposed technology consisted of driving a series of freeze pipes into the soil and waste, using liquid nitrogen to freeze the mass, and extracting the soil and debris using a series of remote operated, bridge crane mounted tools. In conjunction with the freezing and removal activities, temperature and moisture measurements, and air monitoring were performed.

  19. Improved Stratospheric Temperature Retrievals for Climate Reanalysis

    NASA Technical Reports Server (NTRS)

    Rokke, L.; Joiner, J.

    1999-01-01

    The Data Assimilation Office (DAO) is embarking on plans to generate a twenty year reanalysis data set of climatic atmospheric variables. One of the focus points will be in the evaluation of the dynamics of the stratosphere. The Stratospheric Sounding Unit (SSU), flown as part of the TIROS Operational Vertical Sounder (TOVS), is one of the primary stratospheric temperature sensors flown consistently throughout the reanalysis period. Seven unique sensors made the measurements over time, with individual instrument characteristics that need to be addressed. The stratospheric temperatures being assimilated across satellite platforms will profoundly impact the reanalysis dynamical fields. To attempt to quantify aspects of instrument and retrieval bias we are carefully collecting and analyzing all available information on the sensors, their instrument anomalies, forward model errors and retrieval biases. For the retrieval of stratospheric temperatures, we adapted the minimum variance approach of Jazwinski (1970) and Rodgers (1976) and applied it to the SSU soundings. In our algorithm, the state vector contains an initial guess of temperature from a model six hour forecast provided by the Goddard EOS Data Assimilation System (GEOS/DAS). This is combined with an a priori covariance matrix, a forward model parameterization, and specifications of instrument noise characteristics. A quasi-Newtonian iteration is used to obtain convergence of the retrieved state to the measurement vector. This algorithm also enables us to analyze and address the systematic errors associated with the unique characteristics of the cell pressures on the individual SSU instruments and the resolving power of the instruments to vertical gradients in the stratosphere. The preliminary results of the improved retrievals and their assimilation as well as baseline calculations of bias and rms error between the NESDIS operational product and col-located ground measurements will be presented.

  20. FRESCO+: an improved O2 A-band cloud retrieval algorithm for tropospheric trace gas retrievals

    NASA Astrophysics Data System (ADS)

    Wang, P.; Stammes, P.; van der A, R.; Pinardi, G.; van Roozendael, M.

    2008-05-01

    The FRESCO (Fast Retrieval Scheme for Clouds from the Oxygen A-band) algorithm has been used to retrieve cloud information from measurements of the O2 A-band around 760 nm by GOME, SCIAMACHY and GOME-2. The cloud parameters retrieved by FRESCO are the effective cloud fraction and cloud pressure, which are used for cloud correction in the retrieval of trace gases like O3 and NO2. To improve the cloud pressure retrieval for partly cloudy scenes, single Rayleigh scattering has been included in an improved version of the algorithm, called FRESCO+. We compared FRESCO+ and FRESCO effective cloud fractions and cloud pressures using simulated spectra and one month of GOME measured spectra. As expected, FRESCO+ gives more reliable cloud pressures over partly cloudy pixels. Simulations and comparisons with ground-based radar/lidar measurements of clouds shows that the FRESCO+ cloud pressure is about the optical midlevel of the cloud. Globally averaged, the FRESCO+ cloud pressure is about 50 hPa higher than the FRESCO cloud pressure, while the FRESCO+ effective cloud fraction is about 0.01 larger. The effect of FRESCO+ cloud parameters on O3 and NO2 vertical column densities (VCD) is studied using SCIAMACHY data and ground-based DOAS measurements. We find that the FRESCO+ algorithm has a significant effect on tropospheric NO2 retrievals but a minor effect on total O3 retrievals. The retrieved SCIAMACHY tropospheric NO2 VCDs using FRESCO+ cloud parameters (v1.1) are lower than the tropospheric NO2 VCDs which used FRESCO cloud parameters (v1.04), in particular over heavily polluted areas with low clouds. The difference between SCIAMACHY tropospheric NO2 VCDs v1.1 and ground-based MAXDOAS measurements performed in Cabauw, The Netherlands, during the DANDELIONS campaign is about -2.12×1014 molec cm-2.

  1. A probabilistic approach to information retrieval in heterogeneous databases

    SciTech Connect

    Chatterjee, A.; Segev, A.

    1991-08-01

    During the post decade, organizations have increased their scope and operations beyond their traditional geographic boundaries. At the same time, they have adopted heterogeneous and incompatible information systems independent of each other without a careful consideration that one day they may need to be integrated. As a result of this diversity, many important business applications today require access to data stored in multiple autonomous databases. This paper examines a problem of inter-database information retrieval in a heterogeneous environment, where conventional techniques are no longer efficient. To solve the problem, broader definitions for join, union, intersection and selection operators are proposed. Also, a probabilistic method to specify the selectivity of these operators is discussed. An algorithm to compute these probabilities is provided in pseudocode.

  2. 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.

  3. 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. PMID:24883411

  4. Word Spotting for Indic Documents to Facilitate Retrieval

    NASA Astrophysics Data System (ADS)

    Bhardwaj, Anurag; Setlur, Srirangaraj; Govindaraju, Venu

    With advances in the field of digitization of printed documents and several mass digitization projects underway, information retrieval and document search have emerged as key research areas. However, most of the current work in these areas is limited to English and a few oriental languages. The lack of efficient solutions for Indic scripts has hampered information extraction from a large body of documents of cultural and historical importance. This chapter presents two relevant topics in this area. First, we describe the use of a script-specific keyword spotting for Devanagari documents that makes use of domain knowledge of the script. Second, we address the needs of a digital library to provide access to a collection of documents from multiple scripts. This requires intelligent solutions which scale across different scripts. We present a script-independent keyword spotting approach for this purpose. Experimental results illustrate the efficacy of our methods.

  5. Algebraic Modeling of Information Retrieval in XML Documents

    NASA Astrophysics Data System (ADS)

    Georgiev, Bozhidar; Georgieva, Adriana

    2009-11-01

    This paper presents an information retrieval approach in XML documents using tools, based on the linear algebra. The well-known transformation languages as XSLT (XPath) are grounded on the features of higher-order logic for manipulating hierarchical trees. The presented conception is compared to existing higher-order logic formalisms, where the queries are realized by both languages XSLT and XPath. The possibilities of the proposed linear algebraic model combined with hierarchy data models permit more efficient solutions for searching, extracting and manipulating semi-structured data with hierarchical structures avoiding the global navigation over the XML tree components. The main purpose of this algebraic model representation, applied to the hierarchical relationships in the XML data structures, is to make the implementation of linear algebra tools possible for XML data manipulations and to eliminate existing problems, related to regular grammars theory and also to avoid the difficulties, connected with higher -order logic (first-order logic, monadic second- order logic etc.).

  6. 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

  7. Single Shell Tank (SST) Retrieval Project Plan for Tank 241-C-104 Retrieval

    SciTech Connect

    DEFIGH PRICE, C.

    2000-09-20

    In support of the SST Interim Closure Project, Project W-523 ''Tank 241-C-104 Waste Retrieval System'' will provide systems for retrieval and transfer of radioactive waste from tank 241-C-104 (C-104) to the DST staging tank 241-AY-101 (AY-101). At the conclusion of Project W-523, a retrieval system will have been designed and tested to meet the requirements for Acceptance of Beneficial Use and been turned over to operations. Completion of construction and operations of the C-104 retrieval system will meet the recently proposed near-term Tri-Party Agreement milestone, M-45-03F (Proposed Tri-Party Agreement change request M-45-00-01A, August, 30 2000) for demonstrating limits of retrieval technologies on sludge and hard heels in SSTs, reduce near-term storage risks associated with aging SSTs, and provide feed for the tank waste treatment plant. This Project Plan documents the methodology for managing Project W-523; formalizes responsibilities; identifies key interfaces required to complete the retrieval action; establishes the technical, cost, and schedule baselines; and identifies project organizational requirements pertaining to the engineering process such as environmental, safety, quality assurance, change control, design verification, testing, and operational turnover.

  8. Reconstructed key frame and object motion based video retrieval

    NASA Astrophysics Data System (ADS)

    Hu, Shuangyan; Li, Junshan; Li, Kun; Wang, Rui; Yang, Weijun

    2007-11-01

    This paper proposes a video retrieval scheme which can retrieve desired video clips from video databases using color and object motion. The retrieval method includes two steps. In the first step, get the Intra picture frames (I-frames) set from the query MPEG video and reconstruct the key frame of the video based on the set. Then, the video retrieval equals to the retrieval of the reconstructed key frame(R-key frame) and can be easily performed according the methods of content based image retrieval. The second step, the local object motion information that is local motion vector field, is extracted from the video clips set which is the result of the first step, and the final similarity of videos is measured based on the constructed directional histogram. Experimental results show that the proposed two-step retrieval method performed excellently for video retrieval.

  9. Self-generated retrievals while multitasking improve memory for names.

    PubMed

    Helder, Elizabeth; Shaughnessy, John J

    2011-11-01

    We used a translational research paradigm to investigate whether distributed retrievals could benefit name learning in social situations. Undergraduates (N=64) were trained to generate distributed retrievals while they were multitasking. Students learned to generate distributed retrievals according to either an expanding or a uniform schedule. Their self-generated distributed retrievals while they were multitasking were effective in improving name recall for both retrieval schedules. The increase with self-generated retrievals while multitasking was greater (η² =.76) than the increase that Helder and Shaughnessy ( 2008 ) found with experimenter-controlled retrievals while multitasking (η² =.42). These findings provide evidence that the beneficial effect of distributed retrievals can extend to learning names in a social situation.

  10. An integrated content and metadata based retrieval system for art.

    PubMed

    Lewis, Paul H; Martinez, Kirk; Abas, Fazly Salleh; Fauzi, Mohammad Faizal Ahmad; Chan, Stephen C Y; Addis, Matthew J; Boniface, Mike J; Grimwood, Paul; Stevenson, Alison; Lahanier, Christian; Stevenson, James

    2004-03-01

    A new approach to image retrieval is presented in the domain of museum and gallery image collections. Specialist algorithms, developed to address specific retrieval tasks, are combined with more conventional content and metadata retrieval approaches, and implemented within a distributed architecture to provide cross-collection searching and navigation in a seamless way. External systems can access the different collections using interoperability protocols and open standards, which were extended to accommodate content based as well as text based retrieval paradigms. After a brief overview of the complete system, we describe the novel design and evaluation of some of the specialist image analysis algorithms including a method for image retrieval based on sub-image queries, retrievals based on very low quality images and retrieval using canvas crack patterns. We show how effective retrieval results can be achieved by real end-users consisting of major museums and galleries, accessing the distributed but integrated digital collections.

  11. Retrieval Lesson Learned from NAST-I Hyperspectral Data

    NASA Technical Reports Server (NTRS)

    Zhou, Daniel K.; Smith, William L.; Liu, Xu; Larar, Allen M.; Mango, Stephen A.

    2007-01-01

    The retrieval lesson learned is important to many current and future hyperspectral remote sensors. Validated retrieval algorithms demonstrate the advancement of hyperspectral remote sensing capabilities to be achieved with current and future satellite instruments.

  12. A semantic image retrieval approach between visual features and medical concepts

    NASA Astrophysics Data System (ADS)

    Li, Jin; Liang, Hong; Yang, Guangda; Feng, Yaoyu; Lv, Meichao

    2009-07-01

    In the medical domain, digital images are produced in ever-increasing quantities, which offer great opportunities for diagnostics, therapy and training. So how to manage these data and utilize them effectively and efficiently possess significant technical challenges. Thus, the technique of Content-based Medical Image Retrieval (CBMIR) emerges as the times require. However, current CBMIR is not sufficient to capture the semantic content of images. Accordingly, in this paper, an innovative approach for medical image knowledge representation and retrieval is proposed by focusing on the mapping modeling between visual feature and semantic concept. Firstly, the low-level fusion visual features are extracted based on statistical features. Secondly, a set of disjoint semantic tokens with appearance in medical images is selected to define a Visual and Medical Vocabulary. Thirdly, to narrow down the semantic gap and increase the retrieval efficiency, we investigate support vector machine (SVM) to associate low-level visual image features with their highlevel semantic. Experiments are conducted with a medical image DB consisting of 300 diverse medical images obtained from the Hei Longjiang Province Hospital. And the comparison of the retrieval results shows that the approach proposed in this paper is effective.

  13. Formaldehyde scavengers function as novel antigen retrieval agents.

    PubMed

    Vollert, Craig T; Moree, Wilna J; Gregory, Steven; Bark, Steven J; Eriksen, Jason L

    2015-11-27

    Antigen retrieval agents improve the detection of formaldehyde-fixed proteins, but how they work is not well understood. We demonstrate that formaldehyde scavenging represents a key characteristic associated with effective antigen retrieval; under controlled temperature and pH conditions, scavenging improves the typical antigen retrieval process through reversal of formaldehyde-protein adduct formation. This approach provides a rational framework for the identification and development of more effective antigen retrieval agents.

  14. Formaldehyde scavengers function as novel antigen retrieval agents

    PubMed Central

    Vollert, Craig T.; Moree, Wilna J.; Gregory, Steven; Bark, Steven J.; Eriksen, Jason L.

    2015-01-01

    Antigen retrieval agents improve the detection of formaldehyde-fixed proteins, but how they work is not well understood. We demonstrate that formaldehyde scavenging represents a key characteristic associated with effective antigen retrieval; under controlled temperature and pH conditions, scavenging improves the typical antigen retrieval process through reversal of formaldehyde-protein adduct formation. This approach provides a rational framework for the identification and development of more effective antigen retrieval agents. PMID:26612041

  15. Modeling and Retrieval of Cometary Gas Spectral Lines for Rosetta-MIRO Observations Of Comet 67p

    NASA Astrophysics Data System (ADS)

    Lee, Seungwon; von Allmen, P.; Gulkis, S.; Hofstadter, M.; Kamp, L.

    2012-10-01

    The Microwave Instrument for the Rosetta Orbiter (MIRO), on board the ESA Rosetta spacecraft, will observe spectral lines of water, carbon monoxide, ammonia, and methanol at submillimeter wavelengths from the coma of Comet 67P Churyumov-Gerasimenko. Realistic modeling of observations of the cometary gas spectral lines is critical in preparation and interpretation of the MIRO observations. In addition, a reliable and efficient inverse method to retrieve cometary parameters from the observed lines is needed to interprete the observation results and to refine the future observation planning. This paper reports the forward models and retrieval methods developed for the Rosetta-MIRO observations. The forward models start from a nucleus and coma surface condition to a coma profile, to a molecular level distribution, to MIRO spectral lines. A Direct-Simulation Monte Carlo (DSMC) technique is applied to model the gas kinetics in the cometary coma. The population distribution of the molecular levels is calculated using the accelerated Monte Carlo method. The retrieval problem that we faces with MIRO observation is (1) to retrieve coma profiles from the MIRO spectral lines and (2) to retrieve nucleus and coma surface conditions (jets, outgassing rate, outgassing velocity distribution) from the MIRO retrieved coma profile. The optimal estimation theory is applied for the MIRO retrieval problem. By using the forward models in combination, we studied the effect of the physical conditions of the comet nucleus and coma on the observations by MIRO at various observational conditions such as different heliocentric distances, local solar phases, observation distances to the comet nucleus, and viewing angles (e.g. nadir or limb). We also studied the behavior and performance of the retrieval method for various observational data and a priori knowledge. The study results are used to prepare the MIRO observations and refine the forward model and the retrieval scheme.

  16. Assimilating compact phase space retrievals of atmospheric composition with WRF-Chem/DART: a regional chemical transport/ensemble Kalman filter data assimilation system

    NASA Astrophysics Data System (ADS)

    Mizzi, Arthur P.; Arellano, Avelino F., Jr.; Edwards, David P.; Anderson, Jeffrey L.; Pfister, Gabriele G.

    2016-03-01

    This paper introduces the Weather Research and Forecasting Model with chemistry/Data Assimilation Research Testbed (WRF-Chem/DART) chemical transport forecasting/data assimilation system together with the assimilation of compact phase space retrievals of satellite-derived atmospheric composition products. WRF-Chem is a state-of-the-art chemical transport model. DART is a flexible software environment for researching ensemble data assimilation with different assimilation and forecast model options. DART's primary assimilation tool is the ensemble adjustment Kalman filter. WRF-Chem/DART is applied to the assimilation of Terra/Measurement of Pollution in the Troposphere (MOPITT) carbon monoxide (CO) trace gas retrieval profiles. Those CO observations are first assimilated as quasi-optimal retrievals (QORs). Our results show that assimilation of the CO retrievals (i) reduced WRF-Chem's CO bias in retrieval and state space, and (ii) improved the CO forecast skill by reducing the Root Mean Square Error (RMSE) and increasing the Coefficient of Determination (R2). Those CO forecast improvements were significant at the 95 % level. Trace gas retrieval data sets contain (i) large amounts of data with limited information content per observation, (ii) error covariance cross-correlations, and (iii) contributions from the retrieval prior profile that should be removed before assimilation. Those characteristics present challenges to the assimilation of retrievals. This paper addresses those challenges by introducing the assimilation of compact phase space retrievals (CPSRs). CPSRs are obtained by preprocessing retrieval data sets with an algorithm that (i) compresses the retrieval data, (ii) diagonalizes the error covariance, and (iii) removes the retrieval prior profile contribution. Most modern ensemble assimilation algorithms can efficiently assimilate CPSRs. Our results show that assimilation of MOPITT CO CPSRs reduced the number of observations (and assimilation computation

  17. Image-Based Airborne LiDAR Point Cloud Encoding for 3d Building Model Retrieval

    NASA Astrophysics Data System (ADS)

    Chen, Yi-Chen; Lin, Chao-Hung

    2016-06-01

    With the development of Web 2.0 and cyber city modeling, an increasing number of 3D models have been available on web-based model-sharing platforms with many applications such as navigation, urban planning, and virtual reality. Based on the concept of data reuse, a 3D model retrieval system is proposed to retrieve building models similar to a user-specified query. The basic idea behind this system is to reuse these existing 3D building models instead of reconstruction from point clouds. To efficiently retrieve models, the models in databases are compactly encoded by using a shape descriptor generally. However, most of the geometric descriptors in related works are applied to polygonal models. In this study, the input query of the model retrieval system is a point cloud acquired by Light Detection and Ranging (LiDAR) systems because of the efficient scene scanning and spatial information collection. Using Point clouds with sparse, noisy, and incomplete sampling as input queries is more difficult than that by using 3D models. Because that the building roof is more informative than other parts in the airborne LiDAR point cloud, an image-based approach is proposed to encode both point clouds from input queries and 3D models in databases. The main goal of data encoding is that the models in the database and input point clouds can be consistently encoded. Firstly, top-view depth images of buildings are generated to represent the geometry surface of a building roof. Secondly, geometric features are extracted from depth images based on height, edge and plane of building. Finally, descriptors can be extracted by spatial histograms and used in 3D model retrieval system. For data retrieval, the models are retrieved by matching the encoding coefficients of point clouds and building models. In experiments, a database including about 900,000 3D models collected from the Internet is used for evaluation of data retrieval. The results of the proposed method show a clear superiority

  18. A retrieval algorithm for approaching XCH4 from satellite measurements: Sensitivity study and preliminary test

    NASA Astrophysics Data System (ADS)

    Deng, Jianbo; Liu, Yi; Yang, Dongxu; Cai, Zhaonan

    2014-05-01

    Satellite measurements of column-averaged dry air mole fractions of CH4 (XCH4) in shortwave infrared (SWIR) with very high spectral resolution and high sensitivity near the surface, such as the Thermal And Near-infrared Sensor for carbon Observation (TANSO) onboard the Green gas Observing SATellite (GOSAT, launched 2009), are expected to provide the large spatial and temporal information on the sources and sinks of CH4, which would contribute to the understanding of CH4 variation in global region and its impact on climate change. One of the important science requirements of monitoring CH4 from hypsespectral measurements is to establish a highly accurate retrieval algorithm. To approach XCH4efficiently, we developed a SWIR two-band (5900-6150 cm-1 and 4800-4900 cm-1) physical retrieval algorithm after a series of sensitivity study. The forward model in this algorithm was based on a vector linearized discrete ordinate radiative transfer (VLIDORT) model coupled with a line-by-line radiative transfer model (LBLRTM), which was applied to realize online calculation of absorption coefficient and backscattered solar radiance. The information content of CH4, H2O, CO2 and temperature in different retrieval band and bands combination was investigated in order to improve the algorithm. The selected retrieval bands retains more than 90% of the information content of CH4, CO2, and temperature, and more than 85% of that of H2O. The sensitivity studies demonstrate that the uncertainty of H2O, temperature and CO2 will cause unacceptable errors if they were ignored, for example, a 10% bias on H2O profile will lead to 50 ppb retrieval error, and a 5 K shift on temperature profile will cause 20 ppb error to the result while CO2 has little influence. The simulated retrieval test shows it is more efficient to revise the influence of temperature and H2O with a profile model than with a temperature offset and a H2O scale factor model. A preliminarily retrieval test using GOSAT Level 1B

  19. Multiple Object Retrieval in Image Databases Using Hierarchical Segmentation Tree

    ERIC Educational Resources Information Center

    Chen, Wei-Bang

    2012-01-01

    The purpose of this research is to develop a new visual information analysis, representation, and retrieval framework for automatic discovery of salient objects of user's interest in large-scale image databases. In particular, this dissertation describes a content-based image retrieval framework which supports multiple-object retrieval. The…

  20. Visual Based Retrieval Systems and Web Mining--Introduction.

    ERIC Educational Resources Information Center

    Iyengar, S. S.

    2001-01-01

    Briefly discusses Web mining and image retrieval techniques, and then presents a summary of articles in this special issue. Articles focus on Web content mining, artificial neural networks as tools for image retrieval, content-based image retrieval systems, and personalizing the Web browsing experience using media agents. (AEF)