Science.gov

Sample records for near-perfect retrieval efficiency

  1. Flying microwave qubits with nearly perfect transfer efficiency

    NASA Astrophysics Data System (ADS)

    Korotkov, Alexander N.

    2011-07-01

    We propose a procedure for transferring the state a microwave qubit via a transmission line from one resonator to another resonator, with a theoretical efficiency arbitrarily close to 100%. The emission and capture of the microwave energy is performed using tunable couplers, whose transmission coefficients vary in time. Using the superconducting phase qubit technology and tunable couplers with maximum coupling of 100 MHz, the procedure with theoretical efficiency η=0.999 requires a duration of about 400 ns (excluding propagation time) and an on/off ratio of 45. The procedure may also be used for a quantum state transfer with optical photons.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. [Comment on] Toward a near-perfect AGU

    NASA Astrophysics Data System (ADS)

    Ilyas, M.

    For many months I have been troubled by the thought of a near-perfect AGU, deriving my inspiration from the AIP (consisting of eight big scientific societies), which has successfully organized journals in a very information-efficient manner and is able to avoid duplication in its four-dozenodd publications. This is a great value to members who wish to subscribe to individual journals for personal use.The recent Publications Committee letter (Eos, 62, 19, 489) inquiring whether AGU journals should be further split up along our disciplinary lines provided the stimulus for this note. I feel that there is a lot of publication overlap between AGU and AMS. JGR-Space Physics, and JGR-Oceans and Atmospheres duplicate to some extent the coverage of the Journal of Atmospheric Sciences, the Monthly Weather Review, and the Journal of Physical Oceanography. Similarly there is overlap between the third section of JGR and Geophysics, the bulletin of the Society of Exploration Geophysicists. Could there not be a federation of these societies, with one of its primary tasks to reorganize journal publication, cutting down, but not necessarily eliminating, duplication along the AIP lines? I suspect there are a number of other societies that should be included in such a federation.

  9. Nearly Perfect Fluidity in a High Temperature Superconductor

    DOE PAGES

    Rameau, J. D.; Reber, T. J.; Yang, H. -B.; ...

    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.

  10. 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.

  11. 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.

  12. A near-perfect invisibility cloak constructed with homogeneous materials.

    PubMed

    Li, Wei; Guan, Jianguo; Sun, Zhigang; Wang, Wei; Zhang, Qingjie

    2009-12-21

    A near-perfect, non-singular cylindrical invisibility cloak with diamond cross section is achieved by a two-step coordinate transformation. A small line segment is stretched and then blown up into a diamond space, and finally the cloak consisting of four kinds and eight blocks of homogeneous transformation media is obtained. Numerical simulations confirm the well performance of the cloak. The operation bandwidth of the cloak is also investigated. Our scheme is promising to create a simple and well-performed cloak in practice.

  13. Homogeneous near-perfect invisible ground and free space cloak

    NASA Astrophysics Data System (ADS)

    Fazeli, Mohamad; Sedighy, Seyyed Hassan; Hassani, Hamid Reza

    2017-04-01

    A general approach to design near perfect invisible ground and free space cloaks is introduced in this paper. The proposed method which is based on the optical transformation theory, leads to homogeneous constitutive parameters for the cloaks without any singularities. Moreover, the single-step mapping process with linear relations achieves an uncomplicated designing process. Invisibility performance obtained by using this approach does not depend on the incident wave direction, also. The simplicity and design flexibility of the introduced approach with the homogeneity of extracted parameters greatly facilitate the design and fabrication processes of the both proposed ground and free space invisible cloaks. The numerical simulations prove the capability and universality of the proposed design approach.

  14. Near-perfect broadband absorption from hyperbolic metamaterial nanoparticles.

    PubMed

    Riley, Conor T; Smalley, Joseph S T; Brodie, Jeffrey R J; Fainman, Yeshaiahu; Sirbuly, Donald J; Liu, Zhaowei

    2017-02-07

    Broadband absorbers are essential components of many light detection, energy harvesting, and camouflage schemes. Current designs are either bulky or use planar films that cause problems in cracking and delamination during flexing or heating. In addition, transferring planar materials to flexible, thin, or low-cost substrates poses a significant challenge. On the other hand, particle-based materials are highly flexible and can be transferred and assembled onto a more desirable substrate but have not shown high performance as an absorber in a standalone system. Here, we introduce a class of particle absorbers called transferable hyperbolic metamaterial particles (THMMP) that display selective, omnidirectional, tunable, broadband absorption when closely packed. This is demonstrated with vertically aligned hyperbolic nanotube (HNT) arrays composed of alternating layers of aluminum-doped zinc oxide and zinc oxide. The broadband absorption measures >87% from 1,200 nm to over 2,200 nm with a maximum absorption of 98.1% at 1,550 nm and remains large for high angles. Furthermore, we show the advantages of particle-based absorbers by transferring the HNTs to a polymer substrate that shows excellent mechanical flexibility and visible transparency while maintaining near-perfect absorption in the telecommunications region. In addition, other material systems and geometries are proposed for a wider range of applications.

  15. Near-perfect broadband absorption from hyperbolic metamaterial nanoparticles

    NASA Astrophysics Data System (ADS)

    Riley, Conor T.; Smalley, Joseph S. T.; Brodie, Jeffrey R. J.; Fainman, Yeshaiahu; Sirbuly, Donald J.; Liu, Zhaowei

    2017-02-01

    Broadband absorbers are essential components of many light detection, energy harvesting, and camouflage schemes. Current designs are either bulky or use planar films that cause problems in cracking and delamination during flexing or heating. In addition, transferring planar materials to flexible, thin, or low-cost substrates poses a significant challenge. On the other hand, particle-based materials are highly flexible and can be transferred and assembled onto a more desirable substrate but have not shown high performance as an absorber in a standalone system. Here, we introduce a class of particle absorbers called transferable hyperbolic metamaterial particles (THMMP) that display selective, omnidirectional, tunable, broadband absorption when closely packed. This is demonstrated with vertically aligned hyperbolic nanotube (HNT) arrays composed of alternating layers of aluminum-doped zinc oxide and zinc oxide. The broadband absorption measures >87% from 1,200 nm to over 2,200 nm with a maximum absorption of 98.1% at 1,550 nm and remains large for high angles. Furthermore, we show the advantages of particle-based absorbers by transferring the HNTs to a polymer substrate that shows excellent mechanical flexibility and visible transparency while maintaining near-perfect absorption in the telecommunications region. In addition, other material systems and geometries are proposed for a wider range of applications.

  16. Near-perfect broadband absorption from hyperbolic metamaterial nanoparticles

    PubMed Central

    Riley, Conor T.; Smalley, Joseph S. T.; Brodie, Jeffrey R. J.; Fainman, Yeshaiahu; Sirbuly, Donald J.; Liu, Zhaowei

    2017-01-01

    Broadband absorbers are essential components of many light detection, energy harvesting, and camouflage schemes. Current designs are either bulky or use planar films that cause problems in cracking and delamination during flexing or heating. In addition, transferring planar materials to flexible, thin, or low-cost substrates poses a significant challenge. On the other hand, particle-based materials are highly flexible and can be transferred and assembled onto a more desirable substrate but have not shown high performance as an absorber in a standalone system. Here, we introduce a class of particle absorbers called transferable hyperbolic metamaterial particles (THMMP) that display selective, omnidirectional, tunable, broadband absorption when closely packed. This is demonstrated with vertically aligned hyperbolic nanotube (HNT) arrays composed of alternating layers of aluminum-doped zinc oxide and zinc oxide. The broadband absorption measures >87% from 1,200 nm to over 2,200 nm with a maximum absorption of 98.1% at 1,550 nm and remains large for high angles. Furthermore, we show the advantages of particle-based absorbers by transferring the HNTs to a polymer substrate that shows excellent mechanical flexibility and visible transparency while maintaining near-perfect absorption in the telecommunications region. In addition, other material systems and geometries are proposed for a wider range of applications. PMID:28119502

  17. Metallic rugate structures for near-perfect absorbers in visible and near-infrared regions.

    PubMed

    Shu, Shiwei; Li, Yang Yang

    2012-09-01

    Metallic rugate structures are theoretically investigated for achieving near-perfect absorption in the visible and near-infrared regions. Our model builds on nanoporous metal films whose porosity (volume fraction of voids) follows a sinewave along the film thickness. By setting the initial phase of porosity at the top surface as 0, near-perfect absorption is obtained. The impacts of various structural parameters on the characteristic absorption behaviors are studied. Furthermore, multiple peaks or bands with high absorption can be achieved by integrating several periodicities in one structure. The rugate absorbers show near-perfect absorption for TE and TM polarizations and large incident angles.

  18. Efficient search and retrieval in biometric databases

    NASA Astrophysics Data System (ADS)

    Mhatre, Amit J.; Palla, Srinivas; Chikkerur, Sharat; Govindaraju, Venu

    2005-03-01

    Biometric identification has emerged as a reliable means of controlling access to both physical and virtual spaces. Fingerprints, face and voice biometrics are being increasingly used as alternatives to passwords, PINs and visual verification. In spite of the rapid proliferation of large-scale databases, the research has thus far been focused only on accuracy within small databases. In larger applications, response time and retrieval efficiency also become important in addition to accuracy. Unlike structured information such as text or numeric data that can be sorted, biometric data does not have any natural sorting order. Therefore indexing and binning of biometric databases represents a challenging problem. We present results using parallel combination of multiple biometrics to bin the database. Using hand geometry and signature features we show that the search space can be reduced to just 5% of the entire database.

  19. 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

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed Central

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

    2015-01-01

    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. PMID:26195785

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

    PubMed

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

    2015-08-04

    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.

  3. Mid-IR near-perfect absorption with a SiC photonic crystal with angle-controlled polarization selectivity.

    PubMed

    Devarapu, G C R; Foteinopoulou, S

    2012-06-04

    We theoretically investigate mid-IR absorption enhancement with a SiC one-dimensional photonic crystal (PC) microstructure at the frequency regime of the phonon-polariton band gap, where efficient absorption is unattainable in the bulk material. Our study reveals an intricate relationship between absorption efficiency and the energy velocity of light propagation, that is far more complex than hitherto believed. In particular, our findings suggest that absorption peaks away from the photonic-crystal band edge where energy velocity is minimum. While efficient absorption is still associated with a slow-light mode, the latter is faster by at least an order of magnitude in comparison to the bulk material. Moreover, our calculations suggest that absorption becomes optimal when light gradually slow downs as it enters the PC. Relying on this insight, we achieved near-perfect absorption around the phonon-polariton mid-gap frequency with a PC with a suitably terminated end face. We further demonstrate that the near-perfect absorptive property can be tuned with the incident light angle, to be polarization insensitive or polarization selective. We believe our proposed non-metallic paradigm opens up a new route for harnessing infrared absorption with semiconductor and ionic-crystal materials.

  4. Experimental investigation of multiple near-perfect absorptions in sandwich structures containing thin metallic films.

    PubMed

    Liu, Bin; Lu, Guang; Cui, Liyong; Li, Jin; Sun, Feng; Liu, Fen; Li, Yanhui; Yang, Tianlin; Du, Guiqiang

    2017-06-12

    We experimentally investigated near-perfect optical absorption in sandwich structures comprising a thin metallic film whose thickness is larger than the skin depth, a top dielectric layer and a truncated photonic crystal. Single and multiple near-perfect absorptions were realized by tuning the thickness of the top layer. Based on the electromagnetic field intensity distributions at the absorption wavelengths, single near-perfect absorption originated from the tunneling effect of the optical Tamm state, while multiple near-complete absorptions mainly originated from Fabry-Perot resonances. Additionally, the structures showed good one-way absorption properties. The experimental results agreed well with theoretical values. These structures may be important for the fabrication of single or multichannel perfect absorbers.

  5. 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…

  6. 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.

  7. 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)

  8. 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)

  9. 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)

  10. 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.

  11. 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.

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

    SciTech Connect

    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 Al 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.

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

    DOE PAGES

    Hagglund, Carl; Zeltzer, Gabriel; Ruiz, Ricardo; ...

    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

  14. Comparison of texture models for efficient ultrasound image retrieval

    NASA Astrophysics Data System (ADS)

    Bansal, Maggi; Sharma, Vipul; Singh, Sukhwinder

    2013-02-01

    Due to availability of inexpensive and easily available image capturing devices, the size of digital image collection is increasing rapidly. Thus, there is need to create efficient access methods or retrieval tools to search, browse and retrieve images from large multimedia repositories. More specifically, researchers have been engaged on different ways of retrieving images based on their actual content. In particular, Content Based Image Retrieval (CBIR) systems have attracted considerable research and commercial interest in the recent years. In CBIR, visual features characterizing the image content are color, shape and texture. Currently, texture is used to quantify the image content of medical images as it is the most prominent feature that contains information about the spatial distribution of gray levels and variations in brightness. Various texture models like Haralick's Spatial Gray Level Co-occurence Matrix (SGLCM), Gray Level Difference Statistics (GLDS), First-order Statistics (FoS), Statistical Feature Matrix (SFM), Law's Texture Energy Measures (TEM), Fractal features and Fourier Power Spectrum (FPS) features exists in literature. Each of these models visualizes texture in a different way. Retrieval performance depends upon the choice of texture algorithm. Unfortunately, there is no texture model known to work best for encoding texture properties of liver ultrasound images or retrieving most similar images. An experimental comparison of different texture models for Content Based Medical Image Retrieval (CBMIR) is presented in this paper. For the experiments, liver ultrasound image database is used and the retrieval performance of the various texture models is analyzed in detail. The paper concludes with recommendations which texture model performs better for liver ultrasound images. Interestingly, FPS and SGLCM based Haralick's features perform well for liver ultrasound retrieval and thus can be recommended as a simple baseline for such images.

  15. Retrieval Efficiency from Titles and the Cost of Indexing

    ERIC Educational Resources Information Center

    Tell, Bjorn V.

    1971-01-01

    Three experiments were made by a flexible machine search system to test the retrieval efficiency of searching free text and keywords. Results based upon relevance judgements of users indicate that titles and abstracts are good index material which can be used for machine searching without human indexing. (Author/SJ)

  16. Efficient image retrieval approaches for different similarity requirements

    NASA Astrophysics Data System (ADS)

    Tsai, Chiou-Yann; Chen, Arbee L. P.; Essig, Kai

    1999-12-01

    The amount of pictorial data grows enormously with the expansion of the WWW. From the large number of images, it is very important for users to retrieve desired images via an efficient and effective mechanism. In this paper we prose two efficient approaches to facilitate image retrieval by using a simple method to represent the image content. Each image is partitioned into m X n equal-sized sub-images. A color that has enough number of pixels in a block is extracted to represent its content. In the first approach, the image content is represented by the extracted colors of the blocks. The spatial information of images is considered in image retrieval. In the second approach, the colors of the blocks in an image are used to extract objects. A block- level process is process is proposed to perform the region extraction. The spatial information of regions is considered unimportant in image retrieval. Our experiments show that these two block-based approaches can speed up the image retrieval. Moreover, the two approaches are effective for different requirements of image similarity. Users can choose a proper approach to process their queries based on their similarity requirements.

  17. Near-Perfect Synaptic Integration by Nav1.7 in Hypothalamic Neurons Regulates Body Weight.

    PubMed

    Branco, Tiago; Tozer, Adam; Magnus, Christopher J; Sugino, Ken; Tanaka, Shinsuke; Lee, Albert K; Wood, John N; Sternson, Scott M

    2016-06-16

    Neurons are well suited for computations on millisecond timescales, but some neuronal circuits set behavioral states over long time periods, such as those involved in energy homeostasis. We found that multiple types of hypothalamic neurons, including those that oppositely regulate body weight, are specialized as near-perfect synaptic integrators that summate inputs over extended timescales. Excitatory postsynaptic potentials (EPSPs) are greatly prolonged, outlasting the neuronal membrane time-constant up to 10-fold. This is due to the voltage-gated sodium channel Nav1.7 (Scn9a), previously associated with pain-sensation but not synaptic integration. Scn9a deletion in AGRP, POMC, or paraventricular hypothalamic neurons reduced EPSP duration, synaptic integration, and altered body weight in mice. In vivo whole-cell recordings in the hypothalamus confirmed near-perfect synaptic integration. These experiments show that integration of synaptic inputs over time by Nav1.7 is critical for body weight regulation and reveal a mechanism for synaptic control of circuits regulating long term homeostatic functions.

  18. 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.

  19. 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.

  20. Large-Scale Silicon Nanophotonic Metasurfaces with Polarization Independent Near-Perfect Absorption.

    PubMed

    Odebo Länk, Nils; Verre, Ruggero; Johansson, Peter; Käll, Mikael

    2017-04-04

    Optically thin perfect light absorbers could find many uses in science and technology. However, most physical realizations of perfect absorption for the optical range rely on plasmonic excitations in nanostructured metallic metasurfaces, for which the absorbed light energy is quickly lost as heat due to rapid plasmon decay. Here we show that a silicon metasurface excited in a total internal reflection configuration can absorb at least 97% of incident near-infrared light due to interferences between coherent electric and magnetic dipole scattering from the silicon nanopillars that build up the metasurface and the reflected wave from the supporting glass substrate. This "near-perfect" absorption phenomenon loads more than 50 times more light energy into the semiconductor than what would be the case for a uniform silicon sheet of equal surface density, irrespective of incident polarization. We envisage that the concept could be used for the development of novel light harvesting and optical sensor devices.

  1. Bi-layer metamaterials as fully functional near-perfect infrared absorbers

    NASA Astrophysics Data System (ADS)

    Adomanis, Bryan M.; Watts, Claire M.; Koirala, Machhindra; Liu, Xianliang; Tyler, Talmage; West, Kevin G.; Starr, Tatiana; Bringuier, Jonathan N.; Starr, Anthony F.; Jokerst, Nan Marie; Padilla, Willie J.

    2015-07-01

    In this letter, we discuss the design, fabrication, and experimental characterization of a bi-layer fully functional near-perfect metamaterial absorber (MMA) in the long-wavelength infrared (LWIR), which is broadband and generally insensitive to polarization up to a 60° incidence angle. A spectral absorptance of ≥99% was attained simultaneously at multiple LWIR wavelengths, with a bandwidth of 2 μm where the absorptance is ≥90%. This remarkable behavior is attributed to the strong mixing of coupling modes between the two resonators and the ground plane in the presence of a lossy dielectric, in which single layer structures do not exhibit. Furthermore, we show, by comparing two different MMA structures, how the absorption can be tailored by design within and across several IR subdivisions through a slight change in geometrical parameters. The bi-layer MMA has the immediate application of a functionally versatile, low-profile thermal sensor or emitter.

  2. Chip-integrated nearly perfect absorber at telecom wavelengths by graphene coupled with nanobeam cavity.

    PubMed

    Xu, W; Zhu, Z H; Liu, K; Zhang, J F; Yuan, X D; Lu, Q S; Qin, S Q

    2015-07-15

    We exploit the concept of critical coupling to graphene based chip-integrated applications and numerically demonstrate that a chip-integrated nearly perfect graphene absorber at wavelengths around 1.55 μm can be obtained by graphene nearly critical coupling with a nanobeam cavity. The key points are reducing the radiation loss and transmission possibly, together with controlling the coupling rate of the cavity to the input waveguide to be equal to the absorption rate of the cavity caused by graphene. Simulation results show that the absorption of monolayer graphene with a total length of only a few microns is raised up to 97%. Our study may have potential applications in chip-integrated photodetectors.

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    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.

  4. 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

    2013-06-04

    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.

  5. Dynamical tuning between nearly perfect reflection, absorption, and transmission of light via graphene/dielectric structures

    PubMed Central

    Linder, Jacob; Halterman, Klaus

    2016-01-01

    Exerting well-defined control over the reflection (R), absorption (A), and transmission (T) of electromagnetic waves is a key objective in quantum optics. To this end, one often utilizes hybrid structures comprised of elements with different optical properties in order to achieve features such as high R or high A for incident light. A desirable goal would be the possibility to tune between all three regimes of nearly perfect reflection, absorption, and transmission within the same device, thus swapping between the cases R → 1, A → 1, and T → 1 dynamically. We here show that a dielectric interfaced with a graphene layer on each side allows for precisely this: by tuning only the Fermi level of graphene, all three regimes can be reached in the THz regime and below. Moreover, we show that the inclusion of cylindrical defects in the system offers a different type of control of the scattering of electromagnetic waves by means of the graphene layers. PMID:27917886

  6. 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.

  7. Dynamical tuning between nearly perfect reflection, absorption, and transmission of light via graphene/dielectric structures.

    PubMed

    Linder, Jacob; Halterman, Klaus

    2016-12-05

    Exerting well-defined control over the reflection (R), absorption (A), and transmission (T) of electromagnetic waves is a key objective in quantum optics. To this end, one often utilizes hybrid structures comprised of elements with different optical properties in order to achieve features such as high R or high A for incident light. A desirable goal would be the possibility to tune between all three regimes of nearly perfect reflection, absorption, and transmission within the same device, thus swapping between the cases R → 1, A → 1, and T → 1 dynamically. We here show that a dielectric interfaced with a graphene layer on each side allows for precisely this: by tuning only the Fermi level of graphene, all three regimes can be reached in the THz regime and below. Moreover, we show that the inclusion of cylindrical defects in the system offers a different type of control of the scattering of electromagnetic waves by means of the graphene layers.

  8. Nearly Perfect Durable Superhydrophobic Surfaces Fabricated by a Simple One-Step Plasma Treatment.

    PubMed

    Ryu, Jeongeun; Kim, Kiwoong; Park, JooYoung; Hwang, Bae Geun; Ko, YoungChul; Kim, HyunJoo; Han, JeongSu; Seo, EungRyeol; Park, YongJong; Lee, Sang Joon

    2017-05-16

    Fabrication of superhydrophobic surfaces is an area of great interest because it can be applicable to various engineering fields. A simple, safe and inexpensive fabrication process is required to fabricate applicable superhydrophobic surfaces. In this study, we developed a facile fabrication method of nearly perfect superhydrophobic surfaces through plasma treatment with argon and oxygen gases. A polytetrafluoroethylene (PTFE) sheet was selected as a substrate material. We optimized the fabrication parameters to produce superhydrophobic surfaces of superior performance using the Taguchi method. The contact angle of the pristine PTFE surface is approximately 111.0° ± 2.4°, with a sliding angle of 12.3° ± 6.4°. After the plasma treatment, nano-sized spherical tips, which looked like crown-structures, were created. This PTFE sheet exhibits the maximum contact angle of 178.9°, with a sliding angle less than 1°. As a result, this superhydrophobic surface requires a small external force to detach water droplets dripped on the surface. The contact angle of the fabricated superhydrophobic surface is almost retained, even after performing an air-aging test for 80 days and a droplet impacting test for 6 h. This fabrication method can provide superb superhydrophobic surface using simple one-step plasma etching.

  9. High-corrosion-resistance Fe-Mn-Si-based alloys exhibiting nearly perfect shape memory effects

    NASA Astrophysics Data System (ADS)

    Dong, Zhizhong; Kajiwara, Setsuo; Kikuchi, Takehiko; Shinya, Norio

    2004-07-01

    Recently our group has succeeded, by producing very small particles of NbC carbides in austenite, in improvement of shape memory effect (SME) of the low-cost conventional Fe-Mn-Si based SMAs to such an extent that the so-called "training" treatment is no longer necessary. It was also found that the shape memory properties of the Fe-Mn-Si based SMAs were further improved by pre-rolling at 870K. The present paper describes similar improvement of shape memory properties of an Fe-15Mn-5Si-9Cr-5Ni-0.5NbC (mass %) by more convenient way of pre-extension at room temperature. This alloy is high corrosion-resistant (equivalent to SUS430) as well as low cost material, which is also one of the important requisites for industry application in various fields. A nearly perfect shape recover (90%) of an initial 4% strain was achieved when the alloy was pre-extended 12% at room temperature and then aged at 1070K for 10min. The origin of this improvement of SME has been studied by atomic force microscopy (AFM) and trasmission electron microscopy (TEM). It is concluded that uniform distribution of fine martensite plates with the same variant on the primary system is the key factor to obtain a perfect shape memory recovery.

  10. Copper-catalyzed asymmetric allylation of chiral N-tert-butanesulfinyl imines: dual stereocontrol with nearly perfect diastereoselectivity.

    PubMed

    Zhao, Yi-Shuang; Liu, Qiang; Tian, Ping; Tao, Jing-Chao; Lin, Guo-Qiang

    2015-04-14

    Copper-catalyzed asymmetric allylation of chiral N-tert-butanesulfinyl imines has been described. Dual stereocontrol, through the combination of a chiral auxiliary and a chiral copper complex, has played an important role in achieving the nearly perfect diastereoselectivities (all dr > 99 : 1), especially for ketimine substrates.

  11. 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

  12. Efficient Language-Independent Retrieval of Printed Documents without OCR

    NASA Astrophysics Data System (ADS)

    Magdy, Walid; Darwish, Kareem; El-Saban, Motaz

    Recent book digitization initiatives have facilitated the access and search of millions of books. Although OCR remains essential for retrieving printed documents, OCR engines remain limited in the languages they handle and are generally expensive to build. This paper proposes a language independent approach that enables search through printed documents in a way that combines image-based matching with conventional IR techniques without using OCR. While image-based matching can be effective in finding similar words, complementing it with efficient retrieval techniques allows for sub-word matching, term weighting, and document ranking. The basic idea is that similar connected elements in printed documents are clustered and represented with ID’s, which are then used to generate equivalent textual representations. The resultant representations are indexed using an IR engine and searched using the equivalent ID’s of the connected elements in queries. Though, the main benefit of the proposed approach lies in languages for which no OCR exists, the technique was tested on English and Arabic to ascertain the relative effectiveness of the approach. The approach achieves more than 61% relative effectiveness compared to using OCR for both languages. While the reported numbers are lower than that of OCR-based approaches, the proposed method is fully automated, does not require any supervised training, and allows documents to be searchable within a few hours.

  13. Efficient Index for Retrieving Top-k Most Frequent Documents

    NASA Astrophysics Data System (ADS)

    Hon, Wing-Kai; Shah, Rahul; Wu, Shih-Bin

    In the document retrieval problem [9], we are given a collection of documents (strings) of total length D in advance, and our target is to create an index for these documents such that for any subsequent input pattern P, we can identify which documents in the collection contain P. In this paper, we study a natural extension to the above document retrieval problem. We call this top-k frequent document retrieval, where instead of listing all documents containing P, our focus is to identify the top k documents having most occurrences of P. This problem forms a basis for search engine tasks of retrieving documents ranked with TFIDF metric.

  14. Custom Coordination Environments for Lanthanoids: Tripodal Ligands Achieve Near-Perfect Octahedral Coordination for Two Dysprosium-Based Molecular Nanomagnets.

    PubMed

    Lim, Kwang Soo; Baldoví, José J; Jiang, ShangDa; Koo, Bong Ho; Kang, Dong Won; Lee, Woo Ram; Koh, Eui Kwan; Gaita-Ariño, Alejandro; Coronado, Eugenio; Slota, Michael; Bogani, Lapo; Hong, Chang Seop

    2017-05-01

    Controlling the coordination sphere of lanthanoid complexes is a challenging critical step toward controlling their relaxation properties. Here we present the synthesis of hexacoordinated dysprosium single-molecule magnets, where tripodal ligands achieve a near-perfect octahedral coordination. We perform a complete experimental and theoretical investigation of their magnetic properties, including a full single-crystal magnetic anisotropy analysis. The combination of electrostatic and crystal-field computational tools (SIMPRE and CONDON codes) allows us to explain the static behavior of these systems in detail.

  15. 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

  16. 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…

  17. 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…

  18. 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.

  19. Resonance-based metamaterial in the shallow sub-wavelength regime: negative refractive index and nearly perfect absorption

    NASA Astrophysics Data System (ADS)

    Trang Pham, Thi; Nguyen, Hoang Tung; Tuyen Le, Dac; Tong, Ba Tuan; Giang Trinh, Thi; Tuong Pham, Van; Vu, Dinh Lam

    2016-12-01

    The research on magnetic resonances in typical meta-atoms has led to the discovery of electromagnetic metamaterials (MMs). These new materials played a crucial role in achieving extraordinary phenomena as well as promised potential applications. In this paper, we numerically and experimentally investigated two different MM effects: the absorption and the negative refraction, which induced by magnetic resonances in a symmetric structure. The meta-atom sandwich model that includes two parallel flat rings separated by an insulating slab was designed. Firstly, three resonances in sub-wavelength range were demonstrated, revealing the negative permittivity and permeability effects. Notably, negative refractive index (NRI) was gained at the third-gap resonance, resulting from superposition of the rest of the electric resonance and the magnetic one accompanied by multi-plasmon. Moreover, the manipulation of the structural parameters could control the NRI behavior and, interestingly, a nearly perfect absorption peak arises in shallow sub-wavelength regime.

  20. 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.

  1. 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.

  2. 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.

  3. Near-perfect sorting of orbital angular momentum and angular position states of light.

    PubMed

    O'Sullivan, Malcolm N; Mirhosseini, Mohammad; Malik, Mehul; Boyd, Robert W

    2012-10-22

    We present a novel method for efficient sorting of photons prepared in states of orbital angular momentum (OAM) and angular position (ANG). A log-polar optical transform is used in combination with a holographic beam-splitting method to achieve better mode discrimination and reduced cross-talk than reported previously. Simulating this method for 7 modes, we have calculated an improved mutual information of 2.43 bits/photon and 2.29 bits/photon for OAM and ANG modes respectively. In addition, we present preliminary results from an experimental implementation of this technique. This method is expected to have important applications for high-dimensional quantum key distribution systems.

  4. 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.

  5. Efficient retrieval of landscape Hessian: Forced optimal covariance adaptive learning

    NASA Astrophysics Data System (ADS)

    Shir, Ofer M.; Roslund, Jonathan; Whitley, Darrell; Rabitz, Herschel

    2014-06-01

    Knowledge of the Hessian matrix at the landscape optimum of a controlled physical observable offers valuable information about the system robustness to control noise. The Hessian can also assist in physical landscape characterization, which is of particular interest in quantum system control experiments. The recently developed landscape theoretical analysis motivated the compilation of an automated method to learn the Hessian matrix about the global optimum without derivative measurements from noisy data. The current study introduces the forced optimal covariance adaptive learning (FOCAL) technique for this purpose. FOCAL relies on the covariance matrix adaptation evolution strategy (CMA-ES) that exploits covariance information amongst the control variables by means of principal component analysis. The FOCAL technique is designed to operate with experimental optimization, generally involving continuous high-dimensional search landscapes (≳30) with large Hessian condition numbers (≳104). This paper introduces the theoretical foundations of the inverse relationship between the covariance learned by the evolution strategy and the actual Hessian matrix of the landscape. FOCAL is presented and demonstrated to retrieve the Hessian matrix with high fidelity on both model landscapes and quantum control experiments, which are observed to possess nonseparable, nonquadratic search landscapes. The recovered Hessian forms were corroborated by physical knowledge of the systems. The implications of FOCAL extend beyond the investigated studies to potentially cover other physically motivated multivariate landscapes.

  6. Efficient retrieval of landscape Hessian: forced optimal covariance adaptive learning.

    PubMed

    Shir, Ofer M; Roslund, Jonathan; Whitley, Darrell; Rabitz, Herschel

    2014-06-01

    Knowledge of the Hessian matrix at the landscape optimum of a controlled physical observable offers valuable information about the system robustness to control noise. The Hessian can also assist in physical landscape characterization, which is of particular interest in quantum system control experiments. The recently developed landscape theoretical analysis motivated the compilation of an automated method to learn the Hessian matrix about the global optimum without derivative measurements from noisy data. The current study introduces the forced optimal covariance adaptive learning (FOCAL) technique for this purpose. FOCAL relies on the covariance matrix adaptation evolution strategy (CMA-ES) that exploits covariance information amongst the control variables by means of principal component analysis. The FOCAL technique is designed to operate with experimental optimization, generally involving continuous high-dimensional search landscapes (≳30) with large Hessian condition numbers (≳10^{4}). This paper introduces the theoretical foundations of the inverse relationship between the covariance learned by the evolution strategy and the actual Hessian matrix of the landscape. FOCAL is presented and demonstrated to retrieve the Hessian matrix with high fidelity on both model landscapes and quantum control experiments, which are observed to possess nonseparable, nonquadratic search landscapes. The recovered Hessian forms were corroborated by physical knowledge of the systems. The implications of FOCAL extend beyond the investigated studies to potentially cover other physically motivated multivariate landscapes.

  7. Efficient view based 3-D object retrieval using Hidden Markov Model

    NASA Astrophysics Data System (ADS)

    Jain, Yogendra Kumar; Singh, Roshan Kumar

    2013-12-01

    Recent research effort has been dedicated to view based 3-D object retrieval, because of highly discriminative property of 3-D object and has multi view representation. The state-of-art method is highly depending on their own camera array setting for capturing views of 3-D object and use complex Zernike descriptor, HAC for representative view selection which limit their practical application and make it inefficient for retrieval. Therefore, an efficient and effective algorithm is required for 3-D Object Retrieval. In order to move toward a general framework for efficient 3-D object retrieval which is independent of camera array setting and avoidance of representative view selection, we propose an Efficient View Based 3-D Object Retrieval (EVBOR) method using Hidden Markov Model (HMM). In this framework, each object is represented by independent set of view, which means views are captured from any direction without any camera array restriction. In this, views are clustered (including query view) to generate the view cluster, which is then used to build the query model with HMM. In our proposed method, HMM is used in twofold: in the training (i.e. HMM estimate) and in the retrieval (i.e. HMM decode). The query model is trained by using these view clusters. The EVBOR query model is worked on the basis of query model combining with HMM. The proposed approach remove statically camera array setting for view capturing and can be apply for any 3-D object database to retrieve 3-D object efficiently and effectively. Experimental results demonstrate that the proposed scheme has shown better performance than existing methods. [Figure not available: see fulltext.

  8. Magnetic studies reveal near-perfect paramagnetism in the molecular semiconductor vanadyl phthalocyanine (C32H16N8VO)

    NASA Astrophysics Data System (ADS)

    Wang, Zhengjun; Pi, Li; Seehra, Mohindar S.; Bindra, Jasleen; van Tol, Hans; Dalal, Naresh S.

    2017-01-01

    Temperature (0.5-300 K) and magnetic field (H up to 90 kOe) dependences of the magnetization (M) of a powder sample of vanadyl phthalocyanine (VOPc) having the Phase II-triclinic structure are measured and analyzed. The data of χ = M/H vs. T measured in H = 1 kOe fit the modified Curie-Weiss (CW) law, χ = χo+C/(T-θ), with C = 6.266×10-4 emuK/gOe, θ = -0.1 K and χo = -9.3×10-7 emu/gOe. The Curie constant C yields magnetic moment μ = 1.704 μB, S = 1/2, and g = 1.967 characteristic of VO2+. The magnitude of θ = -0.1 K signifying very weak inter-ion antiferromagnetic exchange coupling is supported by the analysis of the variable frequency (9.8-336 GHz) electron paramagnetic resonance data. The isothermal data of M vs. H at ten temperatures between 0.5 K and 300 K when plotted as M vs. H/(T+0.1) collapses on to a single curve given by M = Motanh {gμBH/[2kB(T+0.1)]} with Mo = NgμBS = 9.48 emu/g expected for S = 1/2 system, thus signifying near perfect paramagnetism in VOPc.

  9. Toxoplasma gondii from liquid nitrogen for continuous cell culture: methods to maximise efficient retrieval.

    PubMed

    Mavin, S; Evans, R; Chatterton, J M W; Ashburn, D; Joss, A W L; Ho-Yen, D O

    2003-01-01

    This study aims to increase the efficiency of continuous growth of Toxoplasma gondii in HeLa cells from tachyzoite stocks frozen in liquid nitrogen. Freezing and retrieval of tachyzoites for continuous cell culture requires more stringent protocols than those published for animal culture. The freezing and retrieval conditions are optimised so that a quality harvest (> or = 1 x 10(6) tachyzoites/mL, > or = 90% viability) can be produced using T. gondii recovered from liquid nitrogen as fast and reliably as possible. Retrieval success rate increased from 36% to 100%. An improved freezing procedure using chilled reagents and freshly harvested parasites, and adoption of an effective recovery protocol with retrieval of 3 x 10(7) tachyzoites into 75 cm2 flasks, change of maintenance media after six hours and subsequent blind passage all contributed to this success. The result is faster and more dependable production of T. gondii for diagnostic and experimental use.

  10. Toxoplasma gondii from liquid nitrogen for continuous cell culture:methods to maximise efficient retrieval.

    PubMed

    Mavin, S; Evans, R; Chatterton, J M W; Ashburn, D; Joss, A W L; Ho-Yen, D O

    2003-01-01

    This study aims to increase the efficiency of continuous growth of Toxoplasma gondii in HeLa cells from tachyzoite stocks frozen in liquid nitrogen. Freezing and retrieval of tachyzoites for continuous cell culture requires more stringent protocols than those published for animal culture. The freezing and retrieval conditions are optimised so that a quality harvest (≥ 1 x 10(6) tachyzoites/mL, ≥ 90% viability) can be produced using T. gondii recovered from liquid nitrogen as fast and reliably as possible. Retrieval success rate increased from 36% to 100%. An improved freezing procedure using chilled reagents and freshly harvested parasites, and adoption of an effective recovery protocol with retrieval of 3 x 10(7) tachyzoites into 75cm(2) flasks, change of maintenance media after six hours and subsequent blind passage all contributed to this success. The result is faster and more dependable production of T. gondii for diagnostic and experimental use.

  11. SiNC: Saliency-injected neural codes for representation and efficient retrieval of medical radiographs

    PubMed Central

    Sajjad, Muhammad; Mehmood, Irfan; Baik, Sung Wook

    2017-01-01

    Medical image collections contain a wealth of information which can assist radiologists and medical experts in diagnosis and disease detection for making well-informed decisions. However, this objective can only be realized if efficient access is provided to semantically relevant cases from the ever-growing medical image repositories. In this paper, we present an efficient method for representing medical images by incorporating visual saliency and deep features obtained from a fine-tuned convolutional neural network (CNN) pre-trained on natural images. Saliency detector is employed to automatically identify regions of interest like tumors, fractures, and calcified spots in images prior to feature extraction. Neuronal activation features termed as neural codes from different CNN layers are comprehensively studied to identify most appropriate features for representing radiographs. This study revealed that neural codes from the last fully connected layer of the fine-tuned CNN are found to be the most suitable for representing medical images. The neural codes extracted from the entire image and salient part of the image are fused to obtain the saliency-injected neural codes (SiNC) descriptor which is used for indexing and retrieval. Finally, locality sensitive hashing techniques are applied on the SiNC descriptor to acquire short binary codes for allowing efficient retrieval in large scale image collections. Comprehensive experimental evaluations on the radiology images dataset reveal that the proposed framework achieves high retrieval accuracy and efficiency for scalable image retrieval applications and compares favorably with existing approaches. PMID:28771497

  12. 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.

  13. Improved Characterization of Photosynthetic Efficiency From Remote Sensing Based Leaf Chlorophyll Retrievals

    NASA Astrophysics Data System (ADS)

    Houborg, R.; Cescatti, A.

    2011-12-01

    Photosynthetic efficiency denotes the fraction of light energy conversion during photosynthesis and as a model parameter strongly controls the magnitude of carbon fluxes simulated within land surface modeling schemes. Photosynthetic efficiency is affected by a complex interplay of factors related to species type, plant phenology and physiological condition, nutrient availability and climate, which results in significant temporal and spatial variability. Nevertheless important determinants of photosynthetic efficiency such as the maximum rate of carboxylation (Vcmax) and optimum light-use-efficiency (LUE) are typically assigned fixed literature-based values for broad categories of vegetation environments, due to the lack of appropriate techniques for an accurate representation of their variability in space and time. Remote and proximal sensing retrievals may represent an alternative and effective technique to better characterize the range and variability of these key controls on primary productivity. Houborg et al. (Remote Sens. Env., 115, 2011) demonstrated promising utility of aircraft-based leaf chlorophyll (Cab) retrievals for constraining LUE and thus carbon fluxes over the growing season at a corn field exposed to severe environmental stresses. Here we extend the analysis and report on the utility of Cab retrieved from various remote sensing platforms as a proxy for photosynthetic efficiency and look into methodologies for exploiting Cab information within the Community Land Model (CLM4) for improved flux predictability. One of the major challenges to applying CLM4 over spatial and temporal domains lies in specifying reasonable inputs of Vcmax (or leaf nitrogen concentration) and the key objective is to work toward a verifiable and functional Vcmax - Cab relationship for this purpose.

  14. Multilayer SOM with tree-structured data for efficient document retrieval and plagiarism detection.

    PubMed

    Chow, Tommy W S; Rahman, M K M

    2009-09-01

    This paper proposes a new document retrieval (DR) and plagiarism detection (PD) system using multilayer self-organizing map (MLSOM). A document is modeled by a rich tree-structured representation, and a SOM-based system is used as a computationally effective solution. Instead of relying on keywords/lines, the proposed scheme compares a full document as a query for performing retrieval and PD. The tree-structured representation hierarchically includes document features as document, pages, and paragraphs. Thus, it can reflect underlying context that is difficult to acquire from the currently used word-frequency information. We show that the tree-structured data is effective for DR and PD. To handle tree-structured representation in an efficient way, we use an MLSOM algorithm, which was previously developed by the authors for the application of image retrieval. In this study, it serves as an effective clustering algorithm. Using the MLSOM, local matching techniques are developed for comparing text documents. Two novel MLSOM-based PD methods are proposed. Detailed simulations are conducted and the experimental results corroborate that the proposed approach is computationally efficient and accurate for DR and PD.

  15. Conversion of Wade-Giles to Pinyin: An Estimation of Efficiency Improvement in Retrieval for Item-Specific OPAC Searches.

    ERIC Educational Resources Information Center

    Arsenault, Clement

    1998-01-01

    Discusses the adoption of the pinyin Romanization standard over Wade-Giles and considers the impact on retrieval in online library catalogs. Describes an investigation that tested three factors that could influence retrieval efficiency: the number of usable syllables, the average number of letters per syllable, and users' familiarity with the…

  16. Efficiency image data retrieval based on asynchronous capability aware spatial search service middleware

    NASA Astrophysics Data System (ADS)

    Chen, Nengcheng; Chen, Zeqiang; Gong, Jianya

    2007-11-01

    Recent advances in open geospatial web service, such as Web Coverage Service as well as corresponding web ready data processing service, have led to the generation of large amounts of OGC enabled links on Internet. Recently a few search engines that are specialised with respect to geographic space have appeared. However, users do not always get the effective OGC WCS link information they expect when searching the Web. How to quickly find the correct spatial aware web service in a heterogeneous distributed environment has become a "bottleneck" of geospatial web-based applications. In order to improve the retrieval efficiency of OGC Web Coverage Service (WCS) on WWW, a new methodology for retrieving WCS based on clustering capability aware spatial search service middleware is put forward in this paper.

  17. Using PubMed search strings for efficient retrieval of manual therapy research literature.

    PubMed

    Pillastrini, Paolo; Vanti, Carla; Curti, Stefania; Mattioli, Stefano; Ferrari, Silvano; Violante, Francesco Saverio; Guccione, Andrew

    2015-02-01

    The aim of this study was to construct PubMed search strings that could efficiently retrieve studies on manual therapy (MT), especially for time-constrained clinicians. Our experts chose 11 Medical Subject Heading terms describing MT along with 84 additional potential terms. For each term that was able to retrieve more than 100 abstracts, we systematically extracted a sample of abstracts from which we estimated the proportion of studies potentially relevant to MT. We then constructed 2 search strings: 1 narrow (threshold of pertinent articles ≥40%) and 1 expanded (including all terms for which a proportion had been calculated). We tested these search strings against articles on 2 conditions relevant to MT (thoracic and temporomandibular pain). We calculated the number of abstracts needed to read (NNR) to identify 1 potentially pertinent article in the context of these conditions. Finally, we evaluated the efficiency of the proposed PubMed search strings to identify relevant articles included in a systematic review on spinal manipulative therapy for chronic low back pain. Fifty-five search terms were able to extract more than 100 citations. The NNR to find 1 potentially pertinent article using the narrow string was 1.2 for thoracic pain and 1.3 for temporomandibular pain, and the NNR for the expanded string was 1.9 and 1.6, respectively. The narrow search strategy retrieved all the randomized controlled trials included in the systematic review selected for comparison. The proposed PubMed search strings may help health care professionals locate potentially pertinent articles and review a large number of MT studies efficiently to better implement evidence-based practice. Copyright © 2015 National University of Health Sciences. Published by Elsevier Inc. All rights reserved.

  18. 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

  19. Ultra-broadband near perfect absorption of visible light based on one-dimensional metal-dielectric-metal grating for TM polarization

    NASA Astrophysics Data System (ADS)

    Luo, Minghui; Zhou, Yun; Chen, Linsen; Ye, Yan; Shen, Su; Wu, Shangliang

    2016-10-01

    We numerically and analytically report an ultra-broadband near perfect absorber based on one-dimensional metal-dielectric-metal grating at visible light for TM polarization. A unit cell of this design is composed of metal-dielectric-metal grating, where the bottom metallic layer and the upper metallic coating are separated from each other by the intermediate dielectric grating. The absorber exhibits an average absorption of over 90% in the range 400-700nm. Moreover, they remain very high over a wide range of incident angle up to 45°.The electromagnetic field distributions are investigated, which reveals that this broadband absorption behavior is ascribed to the combination of surface plasmon resonance and cavity resonance. Furthermore, impedance calculations were carried out to explain the absorption behavior. The ultra-broadband near-perfect angle-robust absorber can be a good candidate for many fascinating applications, including solar-energy harvesting as well as producing artificial colors on a large scale substrate.

  20. 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.

  1. Adaptive clustering of image database (ACID) as an efficient tool for improving retrieval in a CBIR system.

    PubMed

    Reljin, Branimir; Zajić, Goran; Reljin, Nikola; Reljin, Irini

    2012-01-01

    The paper describes a content-based image retrieval (CBIR) system with relevance feedback (RF). Instead of standard relevance feedback procedure, an adaptive clustering of image database (ACID) according to particular subjective needs is introduced in our system. Images labeled by the user as relevant are collected in clusters, and their representative members are used in further searching procedure instead of all images contained in the database. By this way, some history of previous retrieving is embedded into a searching process enabling faster and more subjective retrieval. Moreover, clusters are adaptively updated after each retrieving session, following actual user's needs. The efficiency of the proposed ACID system is tested with images from Corel and MIT datasets.

  2. 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

  3. 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.

  4. 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.

  5. Immobilized Pd on magnetic nanoparticles bearing proline as a highly efficient and retrievable Suzuki-Miyaura catalyst in aqueous media.

    PubMed

    Nehlig, E; Waggeh, B; Millot, N; Lalatonne, Y; Motte, L; Guénin, E

    2015-01-14

    A magnetically retrievable nanocatalyst was evaluated for a microwave assisted Suzuki-Miyaura reaction in aqueous media. Excellent yields and conversions were obtained with low Pd loadings (down to 0.01 mol% Pd). It was stable up to 6 months in water under aerobic conditions and efficiency remained unaltered even after 7 repeated cycles.

  6. 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.

  7. Lensless coherent imaging of proteins and supramolecular assemblies: Efficient phase retrieval by the charge flipping algorithm.

    PubMed

    Dumas, Christian; van der Lee, Arie; Palatinus, Lukáš

    2013-05-01

    Diffractive imaging using the intense and coherent beam of X-ray free-electron lasers opens new perspectives for structural studies of single nanoparticles and biomolecules. Simulations were carried out to generate 3D oversampled diffraction patterns of non-crystalline biological samples, ranging from peptides and proteins to megadalton complex assemblies, and to recover their molecular structure from nanometer to near-atomic resolutions. Using these simulated data, we show here that iterative reconstruction methods based on standard and variant forms of the charge flipping algorithm, can efficiently solve the phase retrieval problem and extract a unique and reliable molecular structure. Contrary to the case of conventional algorithms, where the estimation and the use of a compact support is imposed, our approach does not require any prior information about the molecular assembly, and is amenable to a wide range of biological assemblies. Importantly, the robustness of this ab initio approach is illustrated by the fact that it tolerates experimental noise and incompleteness of the intensity data at the center of the speckle pattern.

  8. 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…

  9. Improving the Efficiency of Problem-Solving Practice for Children with Retrieval Difficulties

    ERIC Educational Resources Information Center

    Hopkins, Sarah; de Villiers, Celeste

    2016-01-01

    Despite the importance placed on how children come to solve single-digit addition problems, many children count on to solve these problems when they are expected to use accurate retrieval-based strategies. In this study, we assessed if a subitising intervention improved the rate at which problem-solving practice promoted retrieval, using a…

  10. 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…

  11. Efficient Retrieval of Massive Ocean Remote Sensing Images via a Cloud-Based Mean-Shift Algorithm

    PubMed Central

    Song, Wei; Mei, Haibin

    2017-01-01

    The rapid development of remote sensing (RS) technology has resulted in the proliferation of high-resolution images. There are challenges involved in not only storing large volumes of RS images but also in rapidly retrieving the images for ocean disaster analysis such as for storm surges and typhoon warnings. In this paper, we present an efficient retrieval of massive ocean RS images via a Cloud-based mean-shift algorithm. Distributed construction method via the pyramid model is proposed based on the maximum hierarchical layer algorithm and used to realize efficient storage structure of RS images on the Cloud platform. We achieve high-performance processing of massive RS images in the Hadoop system. Based on the pyramid Hadoop distributed file system (HDFS) storage method, an improved mean-shift algorithm for RS image retrieval is presented by fusion with the canopy algorithm via Hadoop MapReduce programming. The results show that the new method can achieve better performance for data storage than HDFS alone and WebGIS-based HDFS. Speedup and scaleup are very close to linear changes with an increase of RS images, which proves that image retrieval using our method is efficient. PMID:28737699

  12. Efficient Retrieval of Massive Ocean Remote Sensing Images via a Cloud-Based Mean-Shift Algorithm.

    PubMed

    Yang, Mengzhao; Song, Wei; Mei, Haibin

    2017-07-23

    The rapid development of remote sensing (RS) technology has resulted in the proliferation of high-resolution images. There are challenges involved in not only storing large volumes of RS images but also in rapidly retrieving the images for ocean disaster analysis such as for storm surges and typhoon warnings. In this paper, we present an efficient retrieval of massive ocean RS images via a Cloud-based mean-shift algorithm. Distributed construction method via the pyramid model is proposed based on the maximum hierarchical layer algorithm and used to realize efficient storage structure of RS images on the Cloud platform. We achieve high-performance processing of massive RS images in the Hadoop system. Based on the pyramid Hadoop distributed file system (HDFS) storage method, an improved mean-shift algorithm for RS image retrieval is presented by fusion with the canopy algorithm via Hadoop MapReduce programming. The results show that the new method can achieve better performance for data storage than HDFS alone and WebGIS-based HDFS. Speedup and scaleup are very close to linear changes with an increase of RS images, which proves that image retrieval using our method is efficient.

  13. Efficient retrieval of vegetation leaf area index and canopy clumping factor from satellite data to support pollutant deposition assessments.

    PubMed

    Nikolov, Ned; Zeller, Karl

    2006-06-01

    Canopy leaf area index (LAI) is an important structural parameter of the vegetation controlling pollutant uptake by terrestrial ecosystems. This paper presents a computationally efficient algorithm for retrieval of vegetation LAI and canopy clumping factor from satellite data using observed Simple Ratios (SR) of near-infrared to red reflectance. The method employs numerical inversion of a physics-based analytical canopy radiative transfer model that simulates the bi-directional reflectance distribution function (BRDF). The algorithm is independent of ecosystem type. The method is applied to 1-km resolution AVHRR satellite images to retrieve a geo-referenced data set of monthly LAI values for the conterminous USA. Satellite-based LAI estimates are compared against independent ground LAI measurements over a range of ecosystem types. Verification results suggest that the new algorithm represents a viable approach to LAI retrieval at continental scale, and can facilitate spatially explicit studies of regional pollutant deposition and trace gas exchange.

  14. 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

  15. Analysis of osmoadaptation system in budding yeast suggests that regulated degradation of glycerol synthesis enzyme is key to near-perfect adaptation.

    PubMed

    Patel, Anilkumar K; Bhartiya, Sharad; Venkatesh, K V

    2014-06-01

    In order to maintain its turgor pressure at a desired homeostatic level, budding yeast, Saccharomyces cerevisiae responds to the external variation of the osmotic pressure by varying its internal osmotic pressure through regulation of synthesis and transport of the intracellular glycerol. Hog1PP (dually phosphorylated Hog1), a final effector in the signalling pathway of the hyper osmotic stress, regulates the glycerol synthesis both at transcriptional and non-transcriptional stages. It is known that for a step-change in salt concentration leading to moderate osmotic shock, Hog1PP activity shows a transient response before it returns to the vicinity of pre-stimulus level. It is believed that an integrating process in a negative feedback loop can be a design strategy to yield such an adaptive response. Several negative feedback loops have been identified in the osmoadaptation system in yeast. However, the precise location of the integrating process in the osmoadaptation system which includes signalling, gene regulation, metabolism and biophysical modules is unclear. To address this issue, we developed a reduced model which captures various experimental observations of the osmoadaptation behaviour of wild type and mutant strains. Dynamic simulations and steady state analysis suggested that known information about the osmoadaptation system of budding yeast does not necessarily give a perfect integrating process through the known feedback loops of Hog1PP. On the other hand, regulation of glycerol synthesising enzyme degradation can result in a near integrating process leading to a near-perfect adaptation.

  16. "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.

  17. Efficient Content-based Image Retrieval using Support Vector Machines for Feature Aggregation

    NASA Astrophysics Data System (ADS)

    Dimitrovski, Ivica; Loskovska, Suzana; Chorbev, Ivan

    In this paper, a content-based image retrieval system for aggregation and combination of different image features is presented. Feature aggregation is important technique in general content-based image retrieval systems that employ multiple visual features to characterize image content. We introduced and evaluated linear combination and support vector machines to fuse the different image features. The implemented system has several advantages over the existing content-based image retrieval systems. Several implemented features included in our system allow the user to adapt the system to the query image. The SVM-based approach for ranking retrieval results helps processing specific queries for which users do not have knowledge about any suitable descriptors.

  18. 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…

  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. On High Performance of Updates within an Efficient Document Retrieval System.

    ERIC Educational Resources Information Center

    Motzkin, D.

    1994-01-01

    Describes fast, dynamic update algorithms for document retrieval systems. B-trees are discussed; the M-B-T file directory structure is explained; insertions and deletions in inverted files are described; and performance evaluation is discussed. An appendix provides the formal definition of an M-B-T directory. (Contains 18 references.) (LRW)

  2. A viable circulating tumor cell isolation device with high retrieval efficiency using a reversibly deformable membrane barrier

    NASA Astrophysics Data System (ADS)

    Kim, Yoonji; Bu, Jiyoon; Cho, Young-Ho; Son, Il Tae; Kang, Sung-Bum

    2017-02-01

    Circulating tumor cells (CTCs) contain prognostic information of the tumor, since they shed from the primary tumor and invade into the bloodstream. Therefore, the viable isolation is necessary for a consequent analysis of CTCs. Here, we present a device for the viable isolation and efficient retrieval of CTCs using slanted slot filters, formed by a reversibly deformable membrane barrier. Conventional filters have difficulties in retrieving captured cells, since they easily clog the slots. Moreover, large stress concentration at the sharp edges of squared slots, causes cell lysis. In contrast, the present device shows over 94% of high retrieval efficiency, since the slots can be opened simply by relieving the pressure. Furthermore, the inflated membrane barrier naturally forms the slanted slots, thus reducing the cell damage. By using cancer cell lines, we verified that the present device successfully isolate targeted cells, even at an extremely low concentrations (~10 cells/0.1 ml). In the clinical study, 85.7% of patients initially showed CTC positive while the numbers generally decreased after the surgery. We have also proved that the number of CTCs were highly correlated with tumour invasiveness. Therefore, the present device has potential for use in cancer diagnosis, surgical validation, and invasiveness analysis.

  3. 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

    SciTech Connect

    Nouicer, R.

    2016-03-28

    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 ow; followed by hard probe measurements: high-pT hadron suppression, dijet fragment azimuthal correlations, and heavy favor 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 p sNN = 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 ow results from Au + Au at p sNN = 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, =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 facilities RHIC and the LHC

  4. 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

    DOE PAGES

    Nouicer, R.

    2016-03-28

    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 ow; followed by hard probe measurements: high-pT hadron suppression, dijet fragment azimuthal correlations, and heavy favor probes. These measurements are presented for particles of different species asmore » 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 p sNN = 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 ow results from Au + Au at p sNN = 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, =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 facilities RHIC and

  5. 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

  6. Semantic and phonological fluency in children with Down syndrome: atypical organization of language or less efficient retrieval strategies?

    PubMed

    Nash, Hannah M; Snowling, Margaret J

    2008-07-01

    In this study the verbal fluency procedure was used to investigate the organization of semantic and phonological representations in children with Down syndrome (DS) and typically developing children, matched pairwise for receptive vocabulary age. Productivity was found to be significantly reduced in the DS group in both the semantic and the phonological tasks. However, group differences in the number of clusters as opposed to cluster size suggest that this may reflect less efficient retrieval strategies rather than differences in the organization of linguistic representations. Together the findings point to executive deficits in Down syndrome rather than deviant language processes.

  7. 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.

  8. A new indicator of ecosystem water use efficiency based on surfacesoil moisture retrieved from remote sensing

    NASA Astrophysics Data System (ADS)

    Wang, Haiyan

    2017-04-01

    Ecosystem water use efficiency is an important indicator of carbon and water cycle coupling. This studypresents a new measure of water use efficiency, soil water use efficiency (SWUE), based on gross primaryproduction and surface soil moisture derived from remote sensing products (ECV-SM). Variation in SWUEamong biomes, climate conditions, and latitudes from 2000 to 2014 was comprehensively assessed. Aver-age global SWUE over this 15-year period was approximately 3.47 gC/kgH2O. SWUE was relatively highfor ecosystems near the equator and decreased gradually with increasing latitude. At the biome level,high SWUE was measured in evergreen broadleaf forests, and lower values were found in shrublands.Compared with two other commonly used indicators of water use efficiency, EWUE (ratio of gross primaryproduction to evapotranspiration) and RUE (ratio of gross primary production to precipitation), averageSWUE from 2000 to 2014 was significantly higher and had the largest range of values. In addition, spa-tial distributions of these three indicators varied greatly. The new indicator SWUE will help promoteunderstanding of soil water use in various ecosystems.

  9. Optimizing Schedules of Retrieval Practice for Durable and Efficient Learning: How Much Is Enough?

    ERIC Educational Resources Information Center

    Rawson, Katherine A.; Dunlosky, John

    2011-01-01

    The literature on testing effects is vast but supports surprisingly few prescriptive conclusions for how to schedule practice to achieve both durable and efficient learning. Key limitations are that few studies have examined the effects of initial learning criterion or the effects of relearning, and no prior research has examined the combined…

  10. Optimizing Schedules of Retrieval Practice for Durable and Efficient Learning: How Much Is Enough?

    ERIC Educational Resources Information Center

    Rawson, Katherine A.; Dunlosky, John

    2011-01-01

    The literature on testing effects is vast but supports surprisingly few prescriptive conclusions for how to schedule practice to achieve both durable and efficient learning. Key limitations are that few studies have examined the effects of initial learning criterion or the effects of relearning, and no prior research has examined the combined…

  11. Hierarchical hydrodynamic flow confinement: efficient use and retrieval of chemicals for microscale chemistry on surfaces.

    PubMed

    Autebert, Julien; Kashyap, Aditya; Lovchik, Robert D; Delamarche, Emmanuel; Kaigala, Govind V

    2014-04-01

    We devised, implemented, and tested a new concept for efficient local surface chemistry that we call hierarchical hydrodynamic flow confinement (hierarchical HFC). This concept leverages the hydrodynamic shaping of multiple layers of liquid to address challenges inherent to microscale surface chemistry, such as minimal dilution, economical consumption of reagent, and fast liquid switching. We illustrate two modes of hierarchical HFC, nested and pinched, by locally denaturing and recovering a 26 bp DNA with as little as 2% dilution and by efficiently patterning an antibody on a surface, with a 5 μm resolution and a 100-fold decrease of reagent consumption compared to microcontact printing. In addition, valveless switching between nanoliter volumes of liquids was achieved within 20 ms. We believe hierarchical HFC will have broad utility for chemistry on surfaces at the microscale.

  12. 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.

  13. Leveraging Web Services in Providing Efficient Discovery, Retrieval, and Integration of NASA-Sponsored Observations and Predictions

    NASA Astrophysics Data System (ADS)

    Bambacus, M.; Alameh, N.; Cole, M.

    2006-12-01

    The Applied Sciences Program at NASA focuses on extending the results of NASA's Earth-Sun system science research beyond the science and research communities to contribute to national priority applications with societal benefits. By employing a systems engineering approach, supporting interoperable data discovery and access, and developing partnerships with federal agencies and national organizations, the Applied Sciences Program facilitates the transition from research to operations in national applications. In particular, the Applied Sciences Program identifies twelve national applications, listed at http://science.hq.nasa.gov/earth-sun/applications/, which can be best served by the results of NASA aerospace research and development of science and technologies. The ability to use and integrate NASA data and science results into these national applications results in enhanced decision support and significant socio-economic benefits for each of the applications. This paper focuses on leveraging the power of interoperability and specifically open standard interfaces in providing efficient discovery, retrieval, and integration of NASA's science research results. Interoperability (the ability to access multiple, heterogeneous geoprocessing environments, either local or remote by means of open and standard software interfaces) can significantly increase the value of NASA-related data by increasing the opportunities to discover, access and integrate that data in the twelve identified national applications (particularly in non-traditional settings). Furthermore, access to data, observations, and analytical models from diverse sources can facilitate interdisciplinary and exploratory research and analysis. To streamline this process, the NASA GeoSciences Interoperability Office (GIO) is developing the NASA Earth-Sun System Gateway (ESG) to enable access to remote geospatial data, imagery, models, and visualizations through open, standard web protocols. The gateway (online

  14. Leveraging Open Standard Interfaces in Providing Efficient Discovery, Retrieval, and Information of NASA-Sponsored Observations and Predictions

    NASA Astrophysics Data System (ADS)

    Cole, M.; Alameh, N.; Bambacus, M.

    2006-05-01

    The Applied Sciences Program at NASA focuses on extending the results of NASA's Earth-Sun system science research beyond the science and research communities to contribute to national priority applications with societal benefits. By employing a systems engineering approach, supporting interoperable data discovery and access, and developing partnerships with federal agencies and national organizations, the Applied Sciences Program facilitates the transition from research to operations in national applications. In particular, the Applied Sciences Program identifies twelve national applications, listed at http://science.hq.nasa.gov/earth-sun/applications/, which can be best served by the results of NASA aerospace research and development of science and technologies. The ability to use and integrate NASA data and science results into these national applications results in enhanced decision support and significant socio-economic benefits for each of the applications. This paper focuses on leveraging the power of interoperability and specifically open standard interfaces in providing efficient discovery, retrieval, and integration of NASA's science research results. Interoperability (the ability to access multiple, heterogeneous geoprocessing environments, either local or remote by means of open and standard software interfaces) can significantly increase the value of NASA-related data by increasing the opportunities to discover, access and integrate that data in the twelve identified national applications (particularly in non-traditional settings). Furthermore, access to data, observations, and analytical models from diverse sources can facilitate interdisciplinary and exploratory research and analysis. To streamline this process, the NASA GeoSciences Interoperability Office (GIO) is developing the NASA Earth-Sun System Gateway (ESG) to enable access to remote geospatial data, imagery, models, and visualizations through open, standard web protocols. The gateway (online

  15. Selection of buffer pH by the isoelectric point of the antigen for the efficient heat-induced epitope retrieval: re-appraisal for nuclear protein pathobiology.

    PubMed

    Kajiya, Hanako; Takekoshi, Susumu; Takei, Mao; Egashira, Noboru; Miyakoshi, Takashi; Serizawa, Akihito; Teramoto, Akira; Osamura, Robert Y

    2009-12-01

    Epitope retrieval (ER) using heating causes a dramatic improvement in the sensitivity of immunohistochemistry for formalin-fixed paraffin-embedded (FFPE) tissue sections. Here, the relationship between the pH of the retrieval buffer used for heat-induced epitope retrieval (HIER) and the isoelectric points (pI) of the antigen recognized by antibodies against nuclear proteins (mainly human pituitary transcription factors in this study) was investigated using FFPE tissue sections. A universal buffer, with a buffering capacity over a wide pH range from 2.0 to 12.0, was used for HIER. We found that the intensity of staining for most nuclear proteins after HIER depended simply on the pH of the buffer. Importantly, for efficient HIER, antigens with acidic pI required basic pH buffer conditions, while antigens with alkaline pI required acidic conditions. This implies that the electrostatic charge of the antigens contributed significantly to the efficiency of HIER. We conclude that appropriate selection of the pH of the buffer based on the pI of the individual antigens is of great importance for efficient ER. It is concluded that the mechanism of HEIR may, therefore, depend to a large extent on the pI of the antigen under investigation.

  16. High Efficiency Restriction Enzyme–Free Linear Amplification-Mediated Polymerase Chain Reaction Approach for Tracking Lentiviral Integration Sites Does Not Abrogate Retrieval Bias

    PubMed Central

    Wu, Chuanfeng; Jares, Alexander; Winkler, Thomas; Xie, Jianjun; Metais, Jean-Yves

    2013-01-01

    Abstract Retroviral vectors are an efficient and widely employed means of introducing an exogenous expression cassette into target cells. These vectors have been shown to integrate semi-randomly into the cellular genome, and can be associated with genotoxicity due to impact on expression of proximate genes. Therefore, efficient and accurate integration site analysis, while quantifying contributions of individual vector-containing clones, is desirable. Linear amplification-mediated polymerase chain reaction (LAM-PCR) is a widely used technique for identifying integrated proviral and host genomic DNA junctions. However, LAM-PCR is subject to selection bias inherent in the reliance of the assay on the presence of a restriction enzyme–cutting site adjacent to a retrievable integration site, and it is further limited by an inability to discriminate prior to sequencing between the flanking genomic DNA of interest and uninformative internal vector DNA. We report a modified restriction enzyme–free LAM-PCR (Re-free LAM-PCR) approach that is less time and labor intensive compared to conventional LAM-PCR, but in contrast to some other nonrestrictive methods, compares in efficiency and sensitivity, excludes retrieval of uninformative internal vector sequences, and allows retrieval of integration sites unbiased by the presence of nearby restriction sites. However, we report that Re-free LAM-PCR remains inaccurate for quantitation of the relative contributions of individual integration site–containing clones in a polyclonal setting, suggesting that bias in LAM-PCR retrieval of integration sites is not wholly explained by restriction enzyme–related factors. PMID:22992116

  17. High efficiency restriction enzyme-free linear amplification-mediated polymerase chain reaction approach for tracking lentiviral integration sites does not abrogate retrieval bias.

    PubMed

    Wu, Chuanfeng; Jares, Alexander; Winkler, Thomas; Xie, Jianjun; Metais, Jean-Yves; Dunbar, Cynthia E

    2013-01-01

    Retroviral vectors are an efficient and widely employed means of introducing an exogenous expression cassette into target cells. These vectors have been shown to integrate semi-randomly into the cellular genome, and can be associated with genotoxicity due to impact on expression of proximate genes. Therefore, efficient and accurate integration site analysis, while quantifying contributions of individual vector-containing clones, is desirable. Linear amplification-mediated polymerase chain reaction (LAM-PCR) is a widely used technique for identifying integrated proviral and host genomic DNA junctions. However, LAM-PCR is subject to selection bias inherent in the reliance of the assay on the presence of a restriction enzyme-cutting site adjacent to a retrievable integration site, and it is further limited by an inability to discriminate prior to sequencing between the flanking genomic DNA of interest and uninformative internal vector DNA. We report a modified restriction enzyme-free LAM-PCR (Re-free LAM-PCR) approach that is less time and labor intensive compared to conventional LAM-PCR, but in contrast to some other nonrestrictive methods, compares in efficiency and sensitivity, excludes retrieval of uninformative internal vector sequences, and allows retrieval of integration sites unbiased by the presence of nearby restriction sites. However, we report that Re-free LAM-PCR remains inaccurate for quantitation of the relative contributions of individual integration site-containing clones in a polyclonal setting, suggesting that bias in LAM-PCR retrieval of integration sites is not wholly explained by restriction enzyme-related factors.

  18. 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.

  19. Improving carbon, water and energy land-surface flux retrievals using indicators of canopy light use efficiency

    USDA-ARS?s Scientific Manuscript database

    Recent studies have shown that chlorophyll (Cab) can be useful for constraining light-use-efficiency (LUE). LUE defines how efficiently a plant can assimilate carbon dioxide (CO2) given an amount of absorbed Photosynthetically Active Radiation (PAR) and is therefore useful for monitoring carbon flu...

  20. 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)

  1. Slotting optimization of automated storage and retrieval system (AS/RS) for efficient delivery of parts in an assembly shop using genetic algorithm: A case Study

    NASA Astrophysics Data System (ADS)

    Yue, L.; Guan, Z.; He, C.; Luo, D.; Saif, U.

    2017-06-01

    In recent years, the competitive pressure on manufacturing companies shifted them from mass production to mass customization to produce large variety of products. It is a great challenge for companies nowadays to produce customized mixed flow mode of production to meet customized demand on time. Due to large variety of products, the storage system to deliver variety of products to production lines influences on the timely production of variety of products, as investigated from by simulation study of an inefficient storage system of a real Company, in the current research. Therefore, current research proposed a slotting optimization model with mixed model sequence to assemble in consideration of the final flow lines to optimize whole automated storage and retrieval system (AS/RS) and distribution system in the case company. Current research is aimed to minimize vertical height of centre of gravity of AS/RS and total time spent for taking the materials out from the AS/RS simultaneously. Genetic algorithm is adopted to solve the proposed problem and computational result shows significant improvement in stability and efficiency of AS/RS as compared to the existing method used in the case company.

  2. Efficient Shallow Underwater UXO Retrieval

    DTIC Science & Technology

    2009-10-01

    contracted to perform FEA simulations of various sized detonations on the shroud and the recovery equipment. These simulations were performed using Autodyn ...Technology, Inc., http://www.mallett.com/ ANSYS AUTODYN , http://www.ansys.com/products/explicit-dynamics/ autodyn /default.asp A-1 APPENDIX A

  3. Efficient Shallow Underwater UXO Retrieval

    DTIC Science & Technology

    2008-11-01

    and switching capability. For the laboratory tests, the magnet was suspended above the floor using a gantry crane , and a test jig was constructed...4 2-5. The spud assemblies are shown deployed on the recovery vessel. Note the four function crane ...behind the skiff .....................................................................29 5-2. The four-function hydraulic crane from Steelhead

  4. Retrieving similar color images

    NASA Astrophysics Data System (ADS)

    Gagliardi, Isabella; Schettini, Raimondo

    1998-09-01

    There is a great demand for efficient tools that can, on the basis of the pictorial content, organize large quantities of images and rapidly retrieve those of interest. With that goal in mind we present a method for indexing complex color images. The basic idea is to exploit image data decomposition and compression based on the standard Haar multiresolution wavelet transform to describe image content. In this way we are able to effectively eliminate data redundancy and concisely represent the salient features of the image in image signatures of predefined lengths. In the retrieval phase image signatures are compared using a similarity measure that the system has 'learned' from user's. Experimental results confirm the feasibility of our approach, which outperforms more standard procedures, in retrieval accuracy and at lower computational costs.

  5. Golden Retrievers.

    ERIC Educational Resources Information Center

    Christensen, Deborah

    1999-01-01

    Provides a basic definition of metadata, including the usefulness of metatags for online information retrieval and documentation. Defines the elements of the Dublin Core, the next level of metadata. Discusses how librarians can take advantage of metadata. Describes the Gateway to Educational Materials (GEM) Project whose goal is to use metadata to…

  6. Information Retrieval.

    ERIC Educational Resources Information Center

    National Archives and Records Service (GSA), Washington, DC. Office of the National Archives.

    It is the purpose of this handbook to provide managers and their assistants with guidelines for determining where new information processing systems (dissemination, storage and retrieval) might profitably be employed in Government offices and with criteria for selecting the right methods and equipment. While the main objective is to encourage…

  7. Mobile medical image retrieval

    NASA Astrophysics Data System (ADS)

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

    2011-03-01

    Images are an integral part of medical practice for diagnosis, treatment planning and teaching. Image retrieval has gained in importance mainly as a research domain over the past 20 years. Both textual and visual retrieval of images are essential. In the process of mobile devices becoming reliable and having a functionality equaling that of formerly desktop clients, mobile computing has gained ground and many applications have been explored. This creates a new field of mobile information search & access and in this context images can play an important role as they often allow understanding complex scenarios much quicker and easier than free text. Mobile information retrieval in general has skyrocketed over the past year with many new applications and tools being developed and all sorts of interfaces being adapted to mobile clients. This article describes constraints of an information retrieval system including visual and textual information retrieval from the medical literature of BioMedCentral and of the RSNA journals Radiology and Radiographics. Solutions for mobile data access with an example on an iPhone in a web-based environment are presented as iPhones are frequently used and the operating system is bound to become the most frequent smartphone operating system in 2011. A web-based scenario was chosen to allow for a use by other smart phone platforms such as Android as well. Constraints of small screens and navigation with touch screens are taken into account in the development of the application. A hybrid choice had to be taken to allow for taking pictures with the cell phone camera and upload them for visual similarity search as most producers of smart phones block this functionality to web applications. Mobile information access and in particular access to images can be surprisingly efficient and effective on smaller screens. Images can be read on screen much faster and relevance of documents can be identified quickly through the use of images contained in

  8. Skill in Retrievals

    NASA Technical Reports Server (NTRS)

    Aumann, Hartmut H.; Manning, Evan

    2008-01-01

    Retrieval Skill quantifies the ability of one retrieval from a sounder to be more accurate than the best forecast relative to another with the same of another sounder. This is summarized using a Retrieval Anomaly Skill Score (RASS) which is the cor (retrieved-background, truth-background) * sqrt(f), Where f is defined as the ratio of accepted to the possible retrievals. Charts show various features and comparisons of RASS to other methods of retrieval.

  9. 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.

  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 nearly perfect crystals at very low temperatures

    NASA Technical Reports Server (NTRS)

    Weber, J.; Hamilton, J. J.

    1994-01-01

    Data shows that the frequency stability of 5 MHz AT-cut quartz crystal oscillators is improved by lowering the temperature to 4.3 K. The resultant level of stability is apparently not, at this point, sufficient for a clock accurate to 1 part in 10(exp 17). However, many improvements are possible in the scheme presented here. These would involve better temperature regulation, better crystal mounting and vibration isolation, and lower temperatures. Below the lambda-transition at 2.17 K the residual bubbling of the bath would be eliminated. Thus, the prospect of a successful clock built on this scheme is not ruled out.

  12. 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.

  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. Interaction Information Retrieval.

    ERIC Educational Resources Information Center

    Dominich, Sandor

    1994-01-01

    Discussion of information retrieval focuses on an Interaction Information Retrieval model in which documents are interconnected; queries and documents are treated in the same way; and retrieval is the result of the interconnection between query and documents. A theoretical mathematical formulation of this type of retrieval is given. (Contains 31…

  15. Document image retrieval through word shape coding.

    PubMed

    Lu, Shijian; Li, Linlin; Tan, Chew Lim

    2008-11-01

    This paper presents a document retrieval technique that is capable of searching document images without OCR (optical character recognition). The proposed technique retrieves document images by a new word shape coding scheme, which captures the document content through annotating each word image by a word shape code. In particular, we annotate word images by using a set of topological shape features including character ascenders/descenders, character holes, and character water reservoirs. With the annotated word shape codes, document images can be retrieved by either query keywords or a query document image. Experimental results show that the proposed document image retrieval technique is fast, efficient, and tolerant to various types of document degradation.

  16. 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.

  17. Use of light-use efficiency and land-surface temperature as joint constraints in coupled water, energy and carbon flux retrievals

    USDA-ARS?s Scientific Manuscript database

    Dr. John Monteith pioneered the use of light-use efficiency (LUE) as a simple and pragmatic method for studying the impacts of climate on crop growth. Defined as the ratio of carbon uptake and radiation absorbed by vegetation, LUE has become an integral component of many systems modeling carbon flu...

  18. More to Astronomical Images than Meets the Eye: Data Dimension Reduction for Efficient Data Organization, Retrieval and Advanced Visualization and Analysis of Large Multitemporal/Multispectral Data Sets

    NASA Astrophysics Data System (ADS)

    Pesenson, Meyer; Pesenson, I.; Carey, S.; Roby, W.; McCollum, B.; Ingalls, J.; Ardila, D.; Teplitz, H.

    2009-01-01

    Effective analysis of large multispectral and multitemporal data sets demands new ways of data representation. We present applications of standard and original methods of data dimension reduction to astrophysical images (finding significant low-dimensional structures concealed in high-dimensional data). Such methods are widely used already outside of astronomy to effectively analyze large data sets. Data dimension reduction facilitates data organization, retrieval, and analysis (by improving statistical inference), which are crucial to multiwavelength astronomy, archival research, large-scale digital sky surveys and temporal astronomy. These methods allow a user to reduce a large number of FITS images, e.g. each representing a different wavelength, into a few images retaining more than 95% of the original visual information. An immediate simple application of this would be creating a multiwavelength "quick-look" image that includes all essential information in a statistically justified way, and thus is much more accurate than a "quick-look" made by simple coadding with an ad hoc, heuristic weighting. The dimensionally-reduced image is also naturally much smaller in file size in bytes than the total summed size of the non-dimensionally-reduced images. Thus dimensionally-reduced images offer an enormous savings in storage space and database-transmission bandwidth for the user. An analogous process of dimension reduction is possible for a large set of images obtained at the same wavelength but at different times (e.g. LSST images). Other applications of data dimension reduction include, but are not limited to, decorrelating data elements, removing noise, artifact separation, feature extraction, clustering and pattern classification in astronomical images. We demonstrate applications of the algorithms to test cases of current space-based IR data from the Spitzer Space Telescope.

  19. 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.

  20. 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.

  1. 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…

  2. Microfilm and Information Retrieval.

    ERIC Educational Resources Information Center

    Teplitz, Arthur

    This paper was prepared to provide a frame of reference to the role of microfilm within the information retrieval world and to provide an opportunity for evaluation of the use of microforms for active retrieval applications. The paper discusses the principles of information retrieval, considers subject and classification indexing, and describes…

  3. 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…

  4. Retrieval of Emotional Memories

    PubMed Central

    Buchanan, Tony W.

    2008-01-01

    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 amygdala, in combination with the hippocampus and prefrontal cortex, plays an important role in the retrieval of memories for emotional events. The neural regions necessary for online emotional processing also influence emotional memory retrieval, perhaps through the reexperience of emotion during the retrieval process. PMID:17723029

  5. 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. Copyright © 2014 John Wiley & Sons, Ltd.

  6. 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.

  7. Information Retrieval System.

    ERIC Educational Resources Information Center

    Mahle, Jack D., Jr.

    The Fort Detrick Information Retrieval System is a system of computer programs written in COBOL for a CDC 3150 to store and retrieve information about the scientific and technical reports and documents of the Fort Detrick Technical Library. The documents and reports have been abstracted and indexed. This abstract, the subject matter descriptors,…

  8. Natural Language Information Retrieval.

    ERIC Educational Resources Information Center

    Strzalkowski, Tomek

    1995-01-01

    Describes an information retrieval system in which advanced natural language processing is used to enhance the effectiveness of term-based document retrieval by preprocessing the documents; discovering interterm dependencies and build a conceptual hierarchy specific to database domain; and processing the user's natural language requests into…

  9. 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)

  10. 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).

  11. 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

  12. Wire Retrieves Broken Pin

    NASA Technical Reports Server (NTRS)

    Burow, G. H.

    1984-01-01

    Safety wire retains pieces of broken tool. Retrieval wire running through shaft of tool used to pull pieces of tool out of hole, should tool break during use. Safety wire concept suitable for pins subject to deflection or breakage.

  13. RETRIEVAL EQUIPMENT DESCRIPTIONS

    SciTech Connect

    J. Steinhoff

    1997-08-25

    The objective and the scope of this document are to list and briefly describe the major mobile equipment necessary for waste package (WP) retrieval from the proposed subsurface nuclear waste repository at Yucca Mountain. Primary performance characteristics and some specialized design features of the equipment are explained and summarized in the individual subsections of this document. There are no quality assurance requirements or QA controls in this document. Retrieval under normal conditions is accomplished with the same fleet of equipment as is used for emplacement. Descriptions of equipment used for retrieval under normal conditions is found in Emplacement Equipment Descriptions, DI: BCAF00000-01717-5705-00002 (a document in progress). Equipment used for retrieval under abnormal conditions is addressed in this document and consists of the following: (1) Inclined Plane Hauler; (2) Bottom Lift Transporter; (3) Load Haul Dump (LHD) Loader; (4) Heavy Duty Forklift for Emplacement Drifts; (5) Covered Shuttle Car; (6) Multipurpose Vehicle; and (7) Scaler.

  14. Data-Retrieval System

    NASA Technical Reports Server (NTRS)

    Lawrence, P. R.

    1982-01-01

    NASA Graphics and Display System (NGDS) helps solve problem of data retrieval for management. Since NGDS is interactive online system, user controls display content and format, and has capability of always working with latest version of his data.

  15. 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.

  16. 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)

  17. 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)

  18. Personalized image retrieval with user's preference model

    NASA Astrophysics Data System (ADS)

    Kim, Yong-Hwan; Lee, K. E.; Choi, K. S.; Yoo, Ji-Beom; Rhee, Phill-Kyu; Park, Youngchoon

    1998-10-01

    Recently, available information resources in the form of various media have been increased with rapid speed. Many retrieval systems for multimedia information resources have been developed only focused on their efficiency and performance. Therefore, they cannot deal with user's preferences and interests well. In this paper, we present the framework design of a personalized image retrieval system (PIRS) which can reflect user's preferences and interests incrementally. The prototype of PIRS consists of two major parts: user's preference model (UPM) and retrieval module (RM). The UPM plays a role of refining user's query to meet with user's needs. The RM retrieves the proper images for refined query by computing the similarities between each image and refined query, and the retrieved images are ordered by these similarities. In this paper, we mainly discuss about UPM. The incremental machine learning technologies have been employed to provide the user adaptable and intelligent capability to the system. The UPM is implemented by decision tree based on incremental tree induction, and adaptive resonance theory network. User's feedbacks are returned to the UPM, and they modify internal structure of the UPM. User's iterative retrieval activities with PIRS cause the UPM to be revised for user's preferences and interests. Therefore, the PIRS can be adapted to user's preferences and interests. We have achieved encouraging results through experiments.

  19. 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.

  20. 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

  1. Retrieval with gene queries.

    PubMed

    Sehgal, Aditya K; Srinivasan, Padmini

    2006-04-21

    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. 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. 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.

  2. 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.

  3. A Semantic Medical Multimedia Retrieval Approach Using Ontology Information Hiding

    PubMed Central

    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. PMID:24082915

  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. 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.

  6. Retrieval of abstract semantics.

    PubMed

    Noppeney, Uta; Price, Cathy J

    2004-05-01

    Behavioural and neuropsychological evidence suggests that abstract and concrete concepts might be represented, retrieved and processed differently in the human brain. Using fMRI, we demonstrate that retrieval of abstract relative to sensory-based semantics during synonym judgements increased activation in a left frontotemporal system that has been associated with semantic processing particularly at the sentence level. Since activation increases were observed irrespective of the degree of difficulty, we suggest that these differential activations might reflect a particular retrieval mechanism or strategy for abstract concepts. In contrast to sensory-based semantics, the meaning of abstract concepts is largely specified by their usage in language rather than by their relations to the physical world. Subjects might therefore generate an appropriate semantic sentential context to fully explore and specify the meaning of abstract concepts. Our results also explain why abstract semantics is vulnerable to left frontotemporal lesions.

  7. 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.

  8. Retrieval of transuranic waste

    SciTech Connect

    Not Available

    1988-07-19

    Soil removal and drum retrieval equipment are being developed and demonstrated in support of the Transuranic Waste Facility (TWF) program. Accomplishments to date include: Soil removal equipment, a telescoping excavator and high velocity vacuum truck were selected for soil removal; Preliminary demonstrations, the capabilities of both the telescoping excavator and vacuum truck were demonstrated by the vendors; Shielding Lifting Canister, Functional parameters were defined and design is 95% complete; and Full-scale demonstration, SRL test mounds were selected for a full-scale drum retrieval demonstration. Further development will include an integrated full-scale demonstration. Several drums buried in non-radioactive TRU test mounds will be retrieved. Planning for the demonstration is underway. A telescoping excavator is being acquired, the shielded lifting canister will be fabricated and pre-tested, and a vacuum truck will be leased. 5 figs.

  9. Docking and retrieval mechanism

    NASA Technical Reports Server (NTRS)

    Tewell, J. R.; Spencer, R. A.

    1977-01-01

    An engineering prototype docking and retrieval mechanism (DRM) which enables two spacecraft to dock and be structurally joined on-orbit is described. The joining of two spacecraft or payloads on-orbit supports future planned space activities such as payload servicing, deployment and retrieval, and assembly or large space systems. Advantages of the DRM include: it is a nonimpact docking mechanism; does not require impact absorbing mechanisms or attitude stabilization on the target spacecraft; is capable of docking to a spinning spacecraft; and can spin up and deploy a spinning spacecraft or payload.

  10. Docking and retrieval mechanism

    NASA Technical Reports Server (NTRS)

    Tewell, J. R.; Spencer, R. A.

    1977-01-01

    An engineering prototype docking and retrieval mechanism (DRM) is described which enables two spacecraft to dock and be structurally joined on-orbit. The joining of two spacecraft or payloads on-orbit supports future planned space activities such as payload servicing, deployment and retrieval, and assembly of large space systems. The DRM, as developed, provides advantages over prior approaches because it is a nonimpact docking mechanism, does not require impact absorbing mechanisms or attitude stabilization on the target spacecraft, is capable of docking to a spinning spacecraft, and can spin up and deploy a spinning spacecraft or payload.

  11. 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'…

  12. Information Retrieval in Physics.

    ERIC Educational Resources Information Center

    Herschman, Arthur

    Discussed in this paper are the information problems in physics and the current program of the American Institute of Physics (AIP) being conducted in an attempt to develop an information retrieval system. The seriousness of the need is described by means of graphs indicating the exponential rise in the number of physics publications in the last…

  13. 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…

  14. 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…

  15. 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…

  16. 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…

  17. Adaptive MGS Phase Retrieval

    NASA Technical Reports Server (NTRS)

    Basinger, Scott A.; Bikkannavar, Siddarayappa; Cohen, David; Green, Joseph J.; Lou, John; Ohara, Catherine; Redding, David; Shi, Fang

    2008-01-01

    Adaptive MGS Phase Retrieval software uses the Modified Gerchberg-Saxton (MGS) algorithm, an image-based sensing method that can turn any focal plane science instrument into a wavefront sensor, avoiding the need to use external metrology equipment. Knowledge of the wavefront enables intelligent control of active optical systems.

  18. 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.…

  19. 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…

  20. Retrieval Hierarchies in Hypertext.

    ERIC Educational Resources Information Center

    Rada, Roy; And Others

    1993-01-01

    Describes a collaborative, reuse hypertext system, called MUCH (Many Using and Creating Hypertext). The novel browsing and retrieval characteristics of the system are based on a semantic net connecting documents, thesauri, and discussions. Word patterns are documented for reuse, creating and reorganizing network traversal according to user…

  1. Statistical Information Retrieval System.

    ERIC Educational Resources Information Center

    DiFondi, Nicholas M.

    An information retrieval system was developed using technical word occurrences as a basis for classification. A set of words, designated a vocabulary, was selected from the middle range of frequency listing of words occurring in an experimental sample of 94 documents. The selection produced 115 non-function words with technical definition that did…

  2. Indexing and retrieval strategies for natural language fact retrieval

    SciTech Connect

    Kolodner, J.L.

    1983-09-01

    Researchers in artificial intelligence have recently become interested in natural language fact retrieval; currently, their research is at a point where it can begin contributing to the field of information retrieval. In this paper, strategies for a natural language fact retrieval system are mapped out, and approaches to many of the organization and retrieval problems are presented. The CYRUS system, which keeps track of important people and is queried in English, is presented and used to illustrate those solutions. 30 references.

  3. 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.

  4. 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.

  5. 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…

  6. Memory Retrieval as Temporal Discrimination

    ERIC Educational Resources Information Center

    Brown, Gordon D. A.; Vousden, Janet I.; McCormack, Teresa

    2009-01-01

    Temporal distinctiveness models of memory retrieval claim that memories are organised partly in terms of their positions along a temporal dimension, and suggest that memory retrieval involves temporal discrimination. According to such models the retrievability of memories should be related to the discriminability of their temporal distances at the…

  7. 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…

  8. EFFECTIVENESS OF INFORMATION RETRIEVAL METHODS.

    ERIC Educational Resources Information Center

    SWETS, JOHN A.

    RESULTS OF FIFTY DIFFERENT RETRIEVAL METHODS AS APPLIED IN THREE EXPERIMENTAL RETRIEVAL SYSTEMS WERE SUBJECTED TO AN ANALYSIS SUGGESTED BY STATISTICAL DECISION THEORY. THE ANALYSIS USES A PREVIOUSLY-PROPOSED MEASURE OF EFFECTIVENESS AND DEMONSTRATES ITS SEVERAL PROPERTIES. SOME OF THESE PROPERTIES ARE--(1) IT ENABLES THE RETRIEVAL SYSTEM TO…

  9. 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.

  10. Initial retrieval shields against retrieval-induced forgetting.

    PubMed

    Racsmány, Mihály; Keresztes, Attila

    2015-01-01

    Testing, as a form of retrieval, can enhance learning but it can also induce forgetting of related memories, a phenomenon known as retrieval-induced forgetting (RIF). In four experiments we explored whether selective retrieval and selective restudy of target memories induce forgetting of related memories with or without initial retrieval of the entire learning set. In Experiment 1, subjects studied category-exemplar associations, some of which were then either restudied or retrieved. RIF occurred on a delayed final test only when memories were retrieved and not when they were restudied. In Experiment 2, following the study phase of category-exemplar associations, subjects attempted to recall all category-exemplar associations, then they selectively retrieved or restudied some of the exemplars. We found that, despite the huge impact on practiced items, selective retrieval/restudy caused no decrease in final recall of related items. In Experiment 3, we replicated the main result of Experiment 2 by manipulating initial retrieval as a within-subject variable. In Experiment 4 we replicated the main results of the previous experiments with non-practiced (Nrp) baseline items. These findings suggest that initial retrieval of the learning set shields against the forgetting effect of later selective retrieval. Together, our results support the context shift theory of RIF.

  11. 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.

  12. Passage Retrieval and Evaluation

    DTIC Science & Technology

    2005-02-01

    queries, is IDF(t) = log „ # docs. in corpus + 1 0.5 + # docs. t appears in « . (6) This rather ad hoc scoring formula is implemented in the Lemur ...problems with passage R-precision as an evaluation metric. Fernando was instrumental in extending the Lemur toolkit to make all of these experiments...and C. Zhai. The lemur toolkit for language modeling and information retrieval. http://www.cs.cmu.edu/∼ lemur /, 2003. [6] C. Buckley and E. M

  13. Retrievable Inferior Vena Cava Filters: Factors that Affect Retrieval Success

    SciTech Connect

    Geisbuesch, Philipp Benenati, James F.; Pena, Constantino S.; Couvillon, Joseph; Powell, Alex; Gandhi, Ripal; Samuels, Shaun; Uthoff, Heiko

    2012-10-15

    Purpose: To report and analyze the indications, procedural success, and complications of retrievable inferior vena cava filters (rIVCF) placement and to identify parameters that influence retrieval attempt and failure. Methods: Between January 2005 and December 2010, a total of 200 patients (80 men, median age 67 years, range 11-95 years) received a rIVCF with the clinical possibility that it could be removed. All patients with rIVCF were prospectively entered into a database and followed until retrieval or a decision not to retrieve the filter was made. A retrospective analysis of this database was performed. Results: Sixty-one percent of patients had an accepted indication for filter placement; 39% of patients had a relative indication. There was a tendency toward a higher retrieval rate in patients with relative indications (40% vs. 55%, P = 0.076). Filter placement was technically successful in all patients, with no procedure-related mortality. The retrieval rate was 53%. Patient age of >80 years (odds ratio [OR] 0.056, P > 0.0001) and presence of malignancy (OR 0.303, P = 0.003) was associated with a significantly reduced probability for attempted retrieval. Retrieval failure occurred in 7% (6 of 91) of all retrieval attempts. A time interval of > 90 days between implantation and attempted retrieval was associated with retrieval failure (OR 19.8, P = 0.009). Conclusions: Patient age >80 years and a history of malignancy are predictors of a reduced probability for retrieval attempt. The rate of retrieval failure is low and seems to be associated with a time interval of >90 days between filter placement and retrieval.

  14. 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.

  15. Sensitivity of aerosol retrieval over snow surfaces

    NASA Astrophysics Data System (ADS)

    Seidel, F. C.; Painter, T. H.

    2011-12-01

    Significant amounts of black carbon and dust aerosols are transported to and accumulated in snowpacks of mountain ranges around the globe. The direct climate forcing of these particles is increasingly understood, whereas its indirect radiative forcing due to snow albedo and snow cover changes is still under investigation. In-situ and new remote sensing techniques are used to estimate snowpack properties from local to regional scales. Nevertheless, orbital and suborbital Earth observation data are difficult to analyze due to high spatial variability of the snowpack in rugged terrain. In addition, changes in atmospheric turbidity significantly complicate the estimation of snow cover characteristics and requires prior retrieval of optical and microphysical aerosol properties. Unfortunately, most aerosol retrieval techniques work only over dark surfaces. We therefore present a study on the sensitivity of aerosol optical depth (AOD) retrieval over snow surfaces. Radiative transfer calculations show that the sensitivity to surface spectral albedo depends strongly on the aerosol single scattering albedo (ratio of scattering efficiency to total extinction efficiency). Absorbing aerosol types (e.g. soot) provide a relatively good AOD retrieval sensitivity for very bright surfaces. The findings provide a basis for the development of future techniques and algorithms, which are able to concurrently retrieve snow and aerosol properties using remote sensing data. We explore these sensitivities with synthetic data and a time series of imaging spectrometer data, in situ spectral irradiance measurements, and sunphotometer measurements of AOD in the mountains of the Upper Colorado River Basin, USA. Ultimately, this research is important to map and better understand regional influences of aerosol and climate forcings on the cryosphere and water cycle in mountainous and other cold regions.

  16. 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.

  17. 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

  18. Natural language information retrieval in digital libraries

    SciTech Connect

    Strzalkowski, T.; Perez-Carballo, J.; Marinescu, M.

    1996-12-31

    In this paper we report on some recent developments in joint NYU and GE natural language information retrieval system. The main characteristic of this system is the use of advanced natural language processing to enhance the effectiveness of term-based document retrieval. The system is designed around a traditional statistical backbone consisting of the indexer module, which builds inverted index files from pre-processed documents, and a retrieval engine which searches and ranks the documents in response to user queries. Natural language processing is used to (1) preprocess the documents in order to extract content-carrying terms, (2) discover inter-term dependencies and build a conceptual hierarchy specific to the database domain, and (3) process user`s natural language requests into effective search queries. This system has been used in NIST-sponsored Text Retrieval Conferences (TREC), where we worked with approximately 3.3 GBytes of text articles including material from the Wall Street Journal, the Associated Press newswire, the Federal Register, Ziff Communications`s Computer Library, Department of Energy abstracts, U.S. Patents and the San Jose Mercury News, totaling more than 500 million words of English. The system have been designed to facilitate its scalability to deal with ever increasing amounts of data. In particular, a randomized index-splitting mechanism has been installed which allows the system to create a number of smaller indexes that can be independently and efficiently searched.

  19. Inhibition and retrieval of facts in young and older adults.

    PubMed

    Gómez-Ariza, Carlos J; Pelegrina, Santiago; Lechuga, M Teresa; Suárez, Antonio; Bajo, M Teresa

    2009-01-01

    Inhibition is considered to have an important role in memory retrieval. However, many experimental results suggest that its efficiency declines with aging. In this study, the authors tested this hypothesis by using the retrieval-practice task. The retrieval-induced forgetting (RIF) observed with this paradigm is normally explained in terms of inhibition. Young (mean age 21.5 years) and older (mean age 71.6 years) adults studied sets of four shared-subject sentences. A retrieval-practice phase required participants to repeatedly recall a subset of the studied sentences. In the final test, participants were provided item-specific cues and told to recall all the studied sentences. RIF was similar for both age groups, suggesting comparable inhibitory efficiency in young and older adults.

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. The Text Retrieval Conferences (TRECs)

    DTIC Science & Technology

    1996-05-01

    Retrieval and Routing Using the INQUERY System" by John Broglio, James P. Callan, W. Bruce Croft and Daniel W. Nachbar) used a version of...University of Massachusetts at Amherst ("Document Retrieval and Routing Using the INQUERY System" by John Broglio, James P. Callan, W. Bruce Croft...342 terms were used. SIN002, SINOOI -- University of Massachusetts at Amherst ("Document Retrieval and Routing Using the INQUERY System" by John

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. High efficiency Raman memory by suppressing radiation trapping

    NASA Astrophysics Data System (ADS)

    Thomas, S. E.; Munns, J. H. D.; Kaczmarek, K. T.; Qiu, C.; Brecht, B.; Feizpour, A.; Ledingham, P. M.; Walmsley, I. A.; Nunn, J.; Saunders, D. J.

    2017-06-01

    Raman interactions in alkali vapours are used in applications such as atomic clocks, optical signal processing, generation of squeezed light and Raman quantum memories for temporal multiplexing. To achieve a strong interaction the alkali ensemble needs both a large optical depth and a high level of spin-polarisation. We implement a technique known as quenching using a molecular buffer gas which allows near-perfect spin-polarisation of over 99.5 % in caesium vapour at high optical depths of up to ∼ 2× {10}5; a factor of 4 higher than can be achieved without quenching. We use this system to explore efficient light storage with high gain in a GHz bandwidth Raman memory.

  10. NASA develops teleoperator retrieval system

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The teleoperator retrieval system vehicle was designed to reboost and/or deorbit the Skylab; however, usefulness in survey, stabilization, retrieval and delivery was examined. Thrusters, designed for cold gas propulsion, were adapted to hydrazine propulsion. Design specifications and cost analysis are given.

  11. Retrieval Effectiveness on the Web.

    ERIC Educational Resources Information Center

    Savoy, Jacques; Picard, Justin

    2001-01-01

    Discusses the role of search engines in Web usability and analyzes and evaluates the retrieval effectiveness of various indexing and searching strategies on a new Web text collection. Highlights include preprocessing techniques that might improve retrieval effectiveness; and hyperlinks as useful sources of evidence in improving retrieval…

  12. Organizing, Indexing, and Retrieving Information.

    ERIC Educational Resources Information Center

    Fidel, Raya

    1989-01-01

    Reviews the literature that examines new capabilities and new problems associated with online catalogs, online searching of bibliographic databases, indexing, full text retrieval, and expert systems. The need for research that focuses on individual needs and that adopts an integrated approach which views indexing and retrieval as interrelated…

  13. Indexing Depth and Retrieval Effectiveness

    ERIC Educational Resources Information Center

    Seely, Barbara J.

    1972-01-01

    There are six major studies of the effect of indexing depth on retrieval performance. They differ in purpose, methodology, measures, indexing language, field of study, and data base--nevertheless, all have found depth of indexing to have the same effect upon information retrieval. (13 references) (Author/NH)

  14. Student Attitude Toward Information Retrieval.

    ERIC Educational Resources Information Center

    Adair, Charles H.; Allen, Rodney F.

    This is an individually administered rating scale designed to evaluate teacher trainee attitudes toward an information retrieval system. A major goal of the scale is to seek responses that measure students' reactions to the cognitive interest and motivational nature of the information retrieval system through the use of Likert-type items. The…

  15. Vocabulary Control for Information Retrieval.

    ERIC Educational Resources Information Center

    Lancaster, F. W.

    This book deals with properties of vocabularies for indexing and searching document collections; the construction, organization, display, and maintenance of these vocabularies; and the vocabulary as a factor affecting the performance of retrieval systems. Most of the text is concerned with vocabularies for post-coordinate retrieval systems, with…

  16. 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…

  17. 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…

  18. 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…

  19. 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…

  20. Team 2: AIRS Only Retrieval

    NASA Technical Reports Server (NTRS)

    Lee, Sung-Yung; Manning, Evan; Blaisdell, John; Susskind, Joel; Barnet, Chris; Goldberg, Mitch; Cho, Chuck; Staelin, Dave; Blackwelll, Bill

    2005-01-01

    This slide presentation makes the case for the retrieval of data from the Atmospheric Infrared Sounder (AIRS) Advanced Microwave Sounding Unit (AMSU). AIRS only retrieval is not only a risk reduction for failure of AMSU, but also important because NWP centers are reluctant to assimilate AMSU twice.

  1. 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)

  2. An Image Retrieval System using Impressional Words Based on Individual Preference

    NASA Astrophysics Data System (ADS)

    Nambo, Hidetaka; Okamine, Tadashi; Kimura, Haruhiko; Nakazawa, Minoru; Hattori, Shimmi

    When we examine goods with their pictures at online shops, regarding flowers and drawings, it is difficult to give proper keywords for retrieving goods' pictures. To refer their pictures efficiently, image retrieval systems using adjectives called as Kansei words, which represent human feelings, impressions, etc., are proposed. However, since the current systems retrieve pictures without customers' preferences, outputs disagree with the preferences. To cope with the problem, we propose an image retrieval system with Kansei words according to users' preferences. Experimental results have shown the efficiencies of the proposed system comparing with performances of a conventional system.

  3. Learning Short Binary Codes for Large-scale Image Retrieval.

    PubMed

    Liu, Li; Yu, Mengyang; Shao, Ling

    2017-03-01

    Large-scale visual information retrieval has become an active research area in this big data era. Recently, hashing/binary coding algorithms prove to be effective for scalable retrieval applications. Most existing hashing methods require relatively long binary codes (i.e., over hundreds of bits, sometimes even thousands of bits) to achieve reasonable retrieval accuracies. However, for some realistic and unique applications, such as on wearable or mobile devices, only short binary codes can be used for efficient image retrieval due to the limitation of computational resources or bandwidth on these devices. In this paper, we propose a novel unsupervised hashing approach called min-cost ranking (MCR) specifically for learning powerful short binary codes (i.e., usually the code length shorter than 100 b) for scalable image retrieval tasks. By exploring the discriminative ability of each dimension of data, MCR can generate one bit binary code for each dimension and simultaneously rank the discriminative separability of each bit according to the proposed cost function. Only top-ranked bits with minimum cost-values are then selected and grouped together to compose the final salient binary codes. Extensive experimental results on large-scale retrieval demonstrate that MCR can achieve comparative performance as the state-of-the-art hashing algorithms but with significantly shorter codes, leading to much faster large-scale retrieval.

  4. 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)

  5. Annotation and retrieval in protein interaction databases

    NASA Astrophysics Data System (ADS)

    Cannataro, Mario; Hiram Guzzi, Pietro; Veltri, Pierangelo

    2014-06-01

    Biological databases have been developed with a special focus on the efficient retrieval of single records or the efficient computation of specialized bioinformatics algorithms against the overall database, such as in sequence alignment. The continuos production of biological knowledge spread on several biological databases and ontologies, such as Gene Ontology, and the availability of efficient techniques to handle such knowledge, such as annotation and semantic similarity measures, enable the development on novel bioinformatics applications that explicitly use and integrate such knowledge. After introducing the annotation process and the main semantic similarity measures, this paper shows how annotations and semantic similarity can be exploited to improve the extraction and analysis of biologically relevant data from protein interaction databases. As case studies, the paper presents two novel software tools, OntoPIN and CytoSeVis, both based on the use of Gene Ontology annotations, for the advanced querying of protein interaction databases and for the enhanced visualization of protein interaction networks.

  6. Research by retrieving experiments.

    PubMed

    Blagosklonny, Mikhail V

    2007-06-01

    Newton did not discover that apples fall: the information was available prior to his gravitational hypothesis. Hypotheses can be tested not only by performing experiments but also by retrieving experiments from the literature (via PubMed, for example). Here I show how disconnected facts from known data, if properly connected, can generate novel predictions testable in turn by other published data. With examples from cell cycle, aging, cancer and other fields of biology and medicine, I discuss how new knowledge was and will be derived from old information. Millions of experiments have been already performed to test unrelated hypotheses and the results of those experiments are available to 'test' your hypotheses too. But most data (99% by some estimates) remain unpublished, because they were negative, seemed of low priority, or did not fit the story. Yet for other investigators those data may be valuable. The well-known story of Franklin and Watson is a case in point. By making preliminary data widely available, 'data-owners' will benefit most, receiving the credit for otherwise unused results. If posted (pre-published) on searchable databases, these data may fuel thousands of projects without the need for repetitive experiments. Enormous 'pre-published' databases coupled with Google-like search engines can change the structure of scientific research, and shrinking funding will make this inevitable.

  7. 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.

  8. Skin image retrieval using Gabor wavelet texture feature.

    PubMed

    Ou, X; Pan, W; Zhang, X; Xiao, P

    2016-12-01

    Skin imaging plays a key role in many clinical studies. We have used many skin imaging techniques, including the recently developed capacitive contact skin imaging based on fingerprint sensors. The aim of this study was to develop an effective skin image retrieval technique using Gabor wavelet transform, which can be used on different types of skin images, but with a special focus on skin capacitive contact images. Content-based image retrieval (CBIR) is a useful technology to retrieve stored images from database by supplying query images. In a typical CBIR, images are retrieved based on colour, shape, texture, etc. In this study, texture feature is used for retrieving skin images, and Gabor wavelet transform is used for texture feature description and extraction. The results show that the Gabor wavelet texture features can work efficiently on different types of skin images. Although Gabor wavelet transform is slower compared with other image retrieval techniques, such as principal component analysis (PCA) and grey-level co-occurrence matrix (GLCM), Gabor wavelet transform is the best for retrieving skin capacitive contact images and facial images with different orientations. Gabor wavelet transform can also work well on facial images with different expressions and skin cancer/disease images. We have developed an effective skin image retrieval method based on Gabor wavelet transform, that it is useful for retrieving different types of images, namely digital colour face images, digital colour skin cancer and skin disease images, and particularly greyscale skin capacitive contact images. Gabor wavelet transform can also be potentially useful for face recognition (with different orientation and expressions) and skin cancer/disease diagnosis. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  9. 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)

  10. 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)

  11. 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.

  12. Enhancing Sketch-Based Image Retrieval by Re-Ranking and Relevance Feedback.

    PubMed

    Xueming Qian; Xianglong Tan; Yuting Zhang; Richang Hong; Meng Wang

    2016-01-01

    A sketch-based image retrieval often needs to optimize the tradeoff between efficiency and precision. Index structures are typically applied to large-scale databases to realize efficient retrievals. However, the performance can be affected by quantization errors. Moreover, the ambiguousness of user-provided examples may also degrade the performance, when compared with traditional image retrieval methods. Sketch-based image retrieval systems that preserve the index structure are challenging. In this paper, we propose an effective sketch-based image retrieval approach with re-ranking and relevance feedback schemes. Our approach makes full use of the semantics in query sketches and the top ranked images of the initial results. We also apply relevance feedback to find more relevant images for the input query sketch. The integration of the two schemes results in mutual benefits and improves the performance of the sketch-based image retrieval.

  13. 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.

  14. 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.

  15. 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.

  16. A passage retrieval method based on probabilistic information retrieval model and UMLS concepts in biomedical question answering.

    PubMed

    Sarrouti, Mourad; Ouatik El Alaoui, Said

    2017-04-01

    Passage retrieval, the identification of top-ranked passages that may contain the answer for a given biomedical question, is a crucial component for any biomedical question answering (QA) system. Passage retrieval in open-domain QA is a longstanding challenge widely studied over the last decades. However, it still requires further efforts in biomedical QA. In this paper, we present a new biomedical passage retrieval method based on Stanford CoreNLP sentence/passage length, probabilistic information retrieval (IR) model and UMLS concepts. In the proposed method, we first use our document retrieval system based on PubMed search engine and UMLS similarity to retrieve relevant documents to a given biomedical question. We then take the abstracts from the retrieved documents and use Stanford CoreNLP for sentence splitter to make a set of sentences, i.e., candidate passages. Using stemmed words and UMLS concepts as features for the BM25 model, we finally compute the similarity scores between the biomedical question and each of the candidate passages and keep the N top-ranked ones. Experimental evaluations performed on large standard datasets, provided by the BioASQ challenge, show that the proposed method achieves good performances compared with the current state-of-the-art methods. The proposed method significantly outperforms the current state-of-the-art methods by an average of 6.84% in terms of mean average precision (MAP). We have proposed an efficient passage retrieval method which can be used to retrieve relevant passages in biomedical QA systems with high mean average precision. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Highly Efficient visible-light-induced photoactivity of magnetically retrievable Fe3O4@SiO2@Bi2WO6@g-C3N4 hierarchical microspheres for the degradation of organic pollutant and production of hydrogen

    NASA Astrophysics Data System (ADS)

    Lu, Dingze; Wang, Hongmei; Shen, Qingqing; Kondamareddy, Kiran Kumar; Neena D

    2017-07-01

    The new multifunctional composite Fe3O4@SiO2@Bi2WO6@g-C3N4 (FSBG) hierarchical microspheres with Bi2WO6/g-C3N4 heterostructure as an outer shell and Fe3O4@SiO2 as a magnetic core have been synthesized and characterized for photocatalytic applications. An efficient and adoptable approach of synthesizing magnetic Bi2WO6/g-C3N4 hierarchical microspheres of grape-like morphology is realized. The as-synthesized structures exhibit highly efficient visible-light absorption and separation efficiency of photo-induced charge. The visible-light-induced photocatalytic activity of g-C3N4, Fe3O4@SiO2@Bi2WO6, and FSBG is evaluated by investigating the photodegradation of Rhodamine B (RhB) and hydrogen (H2) out of water. The comparative study reveals that the FSBG microspheres exhibit an optimum visible-light-induced photocatalytic activity in degrading Rhodamin B (RhB), which is 3.06 and 1.92 times to that of g-C3N4 and Fe3O4@SiO2@Bi2WO6 systems respectively and 3.89 and 2.31 times in the production of hydrogen (H2) out of water, respectively. The FSBG composite microspheres also exhibit good magnetic recoverability. An alternate mechanism for the enhanced visible-light photocatalytic activity is given in the present manuscript.

  18. Content based image retrieval based on wavelet transform coefficients distribution.

    PubMed

    Lamard, Mathieu; Cazuguel, Guy; Quellec, Gwénolé; Bekri, Lynda; Roux, Christian; Cochener, Béatrice

    2007-01-01

    In this paper we propose a content based image retrieval method for diagnosis aid in medical fields. We characterize images without extracting significant features by using distribution of coefficients obtained by building signatures from the distribution of wavelet transform. The research is carried out by computing signature distances between the query and database images. Several signatures are proposed; they use a model of wavelet coefficient distribution. To enhance results, a weighted distance between signatures is used and an adapted wavelet base is proposed. Retrieval efficiency is given for different databases including a diabetic retinopathy, a mammography and a face database. Results are promising: the retrieval efficiency is higher than 95% for some cases using an optimization process.

  19. Automatic Classification in Information Retrieval.

    ERIC Educational Resources Information Center

    van Rijsbergen, C. J.

    1978-01-01

    Addresses the application of automatic classification methods to the problems associated with computerized document retrieval. Different kinds of classifications are described, and both document and term clustering methods are discussed. References and notes are provided. (Author/JD)

  20. Improved image retrieval based on fuzzy colour feature vector

    NASA Astrophysics Data System (ADS)

    Ben-Ahmeida, Ahlam M.; Ben Sasi, Ahmed Y.

    2013-03-01

    One of Image indexing techniques is the Content-Based Image Retrieval which is an efficient way for retrieving images from the image database automatically based on their visual contents such as colour, texture, and shape. In this paper will be discuss how using content-based image retrieval (CBIR) method by colour feature extraction and similarity checking. By dividing the query image and all images in the database into pieces and extract the features of each part separately and comparing the corresponding portions in order to increase the accuracy in the retrieval. The proposed approach is based on the use of fuzzy sets, to overcome the problem of curse of dimensionality. The contribution of colour of each pixel is associated to all the bins in the histogram using fuzzy-set membership functions. As a result, the Fuzzy Colour Histogram (FCH), outperformed the Conventional Colour Histogram (CCH) in image retrieving, due to its speedy results, where were images represented as signatures that took less size of memory, depending on the number of divisions. The results also showed that FCH is less sensitive and more robust to brightness changes than the CCH with better retrieval recall values.

  1. Interactive ultrasound image retrieval using magnitude frequency spectrum

    NASA Astrophysics Data System (ADS)

    Son, Jae Gon; Kim, Nam Chul; Chun, Young Deok; Park, Jun Hyo; Bae, Jun Ik

    2003-05-01

    An efficient algorithm is proposed for interactive ultrasound image retrieval using magnitude frequency spectrum (MFS). The interactive retrieval is especially intended to be useful for training an intern to diagnose with ultrasound images. In the retrieval process, information on which are relevant to a query image among object images retrieved in the previous iteration is fed back by user interaction. In order to improve discrimination between a query image and each of object images in a database (DB) by using the MFS, which is powerful for ultrasound image retrieval, we incorporate feature vector normalization and root filtering in feature extraction. To effectively integrate the feedback information, we use a feedback scheme based on Rocchio equation, where the feature of a query image is replaced with the weighted average of the feature of a query image and those of object images. Experimental results for real ultrasound images show that while yielding a precision of about 75% at a recall of about 8% in the initial retrieval, the interactive procedure yields a great performance improvement, that is, a precision of about 95% in the third iteration.

  2. 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…

  3. 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…

  4. 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.…

  5. Teaching Skills in Medical Information Retrieval to Medical Students.

    ERIC Educational Resources Information Center

    Kolner, Stuart J.; And Others

    1986-01-01

    A project that attempts to overcome the principal obstacles and to provide an efficient and effective method of teaching information retrieval skills to second-year medical students is described. The method includes a pretest, a diagnosis of deficiencies in information skills, a self-paced learning module, and a posttest. (Author/MLW)

  6. 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.…

  7. 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.

  8. Analysis of a dual-twist Pancharatnam phase device with ultrahigh-efficiency large-angle optical beam steering.

    PubMed

    Cheng, HsienHui; Bhowmik, Achintya K; Bos, Philip J

    2015-12-01

    It has been previously shown that a Pancharatnam phase device with a dual-twist structure can deflect light up to 60° with nearly perfect efficiency. This was beyond the limits previously assumed for these types of devices, which were considered to be optically similar to Raman-Nath gratings. In this paper we first consider the range of parameters that will allow for high efficiency and show the results for a structure that demonstrates 80° deflection. We then explore the light propagation through these devices to point out interesting intensity variations in the deflected mode of light as it traverses the deflecting layer. Finally, we explain the key to understanding the efficiency of these devices, which is not the typical parameters that are important for traditional diffractive devices, but rather the control of the polarization state of light. We provide a simple design approach for optimizing the twist angle and retardation for high efficiency.

  9. 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…

  10. 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…

  11. When Practice Doesn't Lead to Retrieval: An Analysis of Children's Errors with Simple Addition

    ERIC Educational Resources Information Center

    de Villiers, Celéste; Hopkins, Sarah

    2013-01-01

    Counting strategies initially used by young children to perform simple addition are often replaced by more efficient counting strategies, decomposition strategies and rule-based strategies until most answers are encoded in memory and can be directly retrieved. Practice is thought to be the key to developing fluent retrieval of addition facts. This…

  12. 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

  13. 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…

  14. 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…

  15. The role of retrieval mode and retrieval orientation in retrieval practice: insights from comparing recognition memory testing formats and restudying.

    PubMed

    Gao, Chuanji; Rosburg, Timm; Hou, Mingzhu; Li, Bingbing; Xiao, Xin; Guo, Chunyan

    2016-12-01

    The effectiveness of retrieval practice for aiding long-term memory, referred to as the testing effect, has been widely demonstrated. However, the specific neurocognitive mechanisms underlying this phenomenon remain unclear. In the present study, we sought to explore the role of pre-retrieval processes at initial testing on later recognition performance by using event-related potentials (ERPs). Subjects studied two lists of words (Chinese characters) and then performed a recognition task or a source memory task, or restudied the word lists. At the end of the experiment, subjects received a final recognition test based on the remember-know paradigm. Behaviorally, initial testing (active retrieval) enhanced memory retention relative to restudying (passive retrieval). The retrieval mode at initial testing was indexed by more positive-going ERPs for unstudied items in the active-retrieval tasks than in passive retrieval from 300 to 900 ms. Follow-up analyses showed that the magnitude of the early ERP retrieval mode effect (300-500 ms) was predictive of the behavioral testing effect later on. In addition, the ERPs for correctly rejected new items during initial testing differed between the two active-retrieval tasks from 500 to 900 ms, and this ERP retrieval orientation effect predicted differential behavioral testing gains between the two active-retrieval conditions. Our findings confirm that initial testing promotes later retrieval relative to restudying, and they further suggest that adopting pre-retrieval processing in the forms of retrieval mode and retrieval orientation might contribute to these memory enhancements.

  16. 200 A GeV Au + Au collisions serve a nearly perfect quark-gluon liquid.

    PubMed

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

    2011-05-13

    A new robust method to extract the specific shear viscosity (η/s)(QGP) of a quark-gluon plasma (QGP) at temperatures T(c) < T ≲ 2T(c) from the centrality dependence of the eccentricity-scaled elliptic flow v2/ε measured in ultrarelativistic heavy-ion collisions is presented. Coupling viscous fluid dynamics for the QGP with a microscopic transport model for hadronic freeze-out we find for 200 A GeV Au + Au collisions that v2/ε is a universal function of multiplicity density (1/S)(dN(ch)/dy) that depends only on the viscosity but not on the model used for computing the initial fireball eccentricity ε. Comparing with measurements we find 1<4π(η/s)(QGP) < 2.5 where the uncertainty range is dominated by model uncertainties for the values of ε used to normalize the measured v2.

  17. Multi-Spectral Near Perfect Metamaterial Absorbers Using Spatially Multiplexed Plasmon Resonance Metal Square Structures (Preprint)

    DTIC Science & Technology

    2013-10-01

    Refractive properties of magnesium fluoride,” Appl. Opt. 23, 1980-1985 (1984). 41. H.-T. Chen, J. Zhou, J. F. O’Hara, F. Chen, A. K. Azad , and A. J...L. Huang, D. R. Chowdhury, S. Ramani, M. T. Reiten, S.-N. Luo, A. K. Azad , A. J. Taylor, and H. -T. Chen, “Impact of resonator geometry and its

  18. RAPID COMMUNICATION: Vibration immunity and Ampere's circuital law for a near perfect triangular Faraday current sensor

    NASA Astrophysics Data System (ADS)

    Fisher, N. E.; Jackson, D. A.

    1996-08-01

    We report a common-mode rejection scheme for a bulk-optic triangular Faraday current sensor that can eliminate optical noise induced by fibre-link vibration. The sensor's exploitation of Ampere's circuital law is also demonstrated.

  19. Near perfect ultrasonic omnidirectional transducer using the optimal patterning of the zero-index acoustic metamaterials

    NASA Astrophysics Data System (ADS)

    Hyun, Jaeyub; Wang, Semyung

    2016-11-01

    This study proposes the theoretical optimal patterning method based on the geometrical transformation acoustics to design an ultrasonic omnidirectional transducer system, which is composed of the designed near zero-index acoustic metamaterial (ZIAMM). The designed ZIAMM is made of circular rubber rods in water matrix. Meanwhile, the curved unit cell structure is necessary to arrange the designed ZIAMM effectively into the circular-shaped ultrasonic omnidirectional transducer system. To this end, we transform the square unit cell into the curved unit cell in the physical space, instead of starting from a homogeneous medium. Also the periodic boundary condition in the two-dimensional polar coordinate is proposed to calculate the dynamic characteristic (i.e., the effective material properties and the dispersion relation) according to the curvature of curved unit cell. The proposed optimal patterning method is verified through the ZIAMM-based ultrasonic omnidirectional transducer system. Especially the radiation performance of ZIAMM-based ultrasonic omnidirectional transducer system is greatly improved by this optimal patterning.

  20. Neural network analysis of lymphoma microarray data: prognosis and diagnosis near-perfect

    PubMed Central

    O'Neill, Michael C; Song, Li

    2003-01-01

    Background Microarray chips are being rapidly deployed as a major tool in genomic research. To date most of the analysis of the enormous amount of information provided on these chips has relied on clustering techniques and other standard statistical procedures. These methods, particularly with regard to cancer patient prognosis, have generally been inadequate in providing the reduced gene subsets required for perfect classification. Results Networks trained on microarray data from DLBCL lymphoma patients have, for the first time, been able to predict the long-term survival of individual patients with 100% accuracy. Other networks were able to distinguish DLBCL lymphoma donors from other donors, including donors with other lymphomas, with 99% accuracy. Differentiating the trained network can narrow the gene profile to less than three dozen genes for each classification. Conclusions Here we show that artificial neural networks are a superior tool for digesting microarray data both with regard to making distinctions based on the data and with regard to providing very specific reference as to which genes were most important in making the correct distinction in each case. PMID:12697066

  1. Phase retrieval and diffractive imaging based on Babinet's principle and complementary random sampling.

    PubMed

    Cheng, Zhen-Jia; Wang, Ben-Yi; Xie, Yi-Yan; Lu, Yu-Jie; Yue, Qing-Yang; Guo, Cheng-Shan

    2015-11-02

    We proposed an iterative method for phase retrieval and diffractive imaging based on Babinet's principle and complementary random sampling (CRS). We demonstrated that the whole complex amplitude (not sieved) of an object wave can be accurately retrieved from the diffraction intensities of the object wave sampled by a group of binary CRS masks and the diffractive imaging for the object can be realized through a single digital inverse diffraction. Some experimental results are given for the demonstration. Our experimental results reveal that, using CRS, the influence of a binary random sampling mask on the retrieved field can be well eliminated, and the accuracy and efficiency of the phase retrieval can be greatly improved.

  2. Temporal structure in associative retrieval

    PubMed Central

    Kurth-Nelson, Zeb; Barnes, Gareth; Sejdinovic, Dino; Dolan, Ray; Dayan, Peter

    2015-01-01

    Electrophysiological data disclose rich dynamics in patterns of neural activity evoked by sensory objects. Retrieving objects from memory reinstates components of this activity. In humans, the temporal structure of this retrieved activity remains largely unexplored, and here we address this gap using the spatiotemporal precision of magnetoencephalography (MEG). In a sensory preconditioning paradigm, 'indirect' objects were paired with 'direct' objects to form associative links, and the latter were then paired with rewards. Using multivariate analysis methods we examined the short-time evolution of neural representations of indirect objects retrieved during reward-learning about direct objects. We found two components of the evoked representation of the indirect stimulus, 200 ms apart. The strength of retrieval of one, but not the other, representational component correlated with generalization of reward learning from direct to indirect stimuli. We suggest the temporal structure within retrieved neural representations may be key to their function. DOI: http://dx.doi.org/10.7554/eLife.04919.001 PMID:25615722

  3. Web-based multimedia information retrieval for clinical application research

    NASA Astrophysics Data System (ADS)

    Cao, Xinhua; Hoo, Kent S., Jr.; Zhang, Hong; Ching, Wan; Zhang, Ming; Wong, Stephen T. C.

    2001-08-01

    We described a web-based data warehousing method for retrieving and analyzing neurological multimedia information. The web-based method supports convenient access, effective search and retrieval of clinical textual and image data, and on-line analysis. To improve the flexibility and efficiency of multimedia information query and analysis, a three-tier, multimedia data warehouse for epilepsy research has been built. The data warehouse integrates clinical multimedia data related to epilepsy from disparate sources and archives them into a well-defined data model.

  4. Image retrieval method based on metric learning for convolutional neural network

    NASA Astrophysics Data System (ADS)

    Wang, Jieyuan; Qian, Ying; Ye, Qingqing; Wang, Biao

    2017-09-01

    At present, the research of content-based image retrieval (CBIR) focuses on learning effective feature for the representations of origin images and similarity measures. The retrieval accuracy and efficiency are crucial to a CBIR. With the rise of deep learning, convolutional network is applied in the domain of image retrieval and achieved remarkable results, but the image visual feature extraction of convolutional neural network exist high dimension problems, this problem makes the image retrieval and speed ineffective. This paper uses the metric learning for the image visual features extracted from the convolutional neural network, decreased the feature redundancy, improved the retrieval performance. The work in this paper is also a necessary part for further implementation of feature hashing to the approximate-nearest-neighbor (ANN) retrieval method.

  5. A study of retrieval accuracy of pulmonary nodules based on external attachment

    NASA Astrophysics Data System (ADS)

    Dhara, Ashis Kumar; Mukhopadhyay, Sudipta; Mehre, Shrikant A.; Khandelwal, Niranjan; Prabhakar, Nidhi; Garg, Mandeep; Kalra, Naveen

    2017-03-01

    In this paper, retrieval accuracy of different types of pulmonary nodules is studied. The trainee radiologists could enrich their knowledge using the visual information of the retrieved nodules. In the proposed retrieval system, the pulmonary nodules are segmented using a semi-automated technique. Several 3D features are explored to improve the performance of the proposed retrieval system. A set of relevant shape and texture features is determined for efficient representation of the nodules in the feature space. The proposed CBIR system is validated on a data set of 542 nodules of Lung Image Database Consortium and Image Database Resource Initiative (LIDC/IDRI). The nodules with composite rank of malignancy "1", "2" are considered as benign and "4", "5" are considered as malignant. Considering top five retrieved images, the precision of the proposed retrieval system are 84.76%, 80.75%, and 80.34% for well-circumscribed, juxta-pleural, and juxtavascular nodules, respectively.

  6. Intelligent web image retrieval system

    NASA Astrophysics Data System (ADS)

    Hong, Sungyong; Lee, Chungwoo; Nah, Yunmook

    2001-07-01

    Recently, the web sites such as e-business sites and shopping mall sites deal with lots of image information. To find a specific image from these image sources, we usually use web search engines or image database engines which rely on keyword only retrievals or color based retrievals with limited search capabilities. This paper presents an intelligent web image retrieval system. We propose the system architecture, the texture and color based image classification and indexing techniques, and representation schemes of user usage patterns. The query can be given by providing keywords, by selecting one or more sample texture patterns, by assigning color values within positional color blocks, or by combining some or all of these factors. The system keeps track of user's preferences by generating user query logs and automatically add more search information to subsequent user queries. To show the usefulness of the proposed system, some experimental results showing recall and precision are also explained.

  7. Retrieval interference in sentence comprehension

    PubMed Central

    Van Dyke, Julie A.; McElree, Brian

    2007-01-01

    The role of interference effects in sentence processing has recently begun to receive attention, however whether these effects arise during encoding or retrieval remains unclear. This paper draws on basic memory research to help distinguish these explanations and reports data from an experiment that manipulates the possibility for retrieval interference while holding encoding conditions constant. We found clear support for the principle of cue-overload, wherein cues available at retrieval cannot uniquely distinguish among competitors, thus giving rise to interference effects. We discuss the data in relation to a cue-based parsing framework (Van Dyke & Lewis, 2003) and other interference effects observed in sentence processing (e.g., Gordon, Hendrick, & Johnson, 2001, 2004). We conclude from the available data that the memory system that subserves language comprehension operates according to similar principles as memory in other domains. PMID:18209744

  8. Rapid Retrieval of Lung Nodule CT Images Based on Hashing and Pruning Methods.

    PubMed

    Pan, Ling; Qiang, Yan; Yuan, Jie; Wu, Lidong

    2016-01-01

    The similarity-based retrieval of lung nodule computed tomography (CT) images is an important task in the computer-aided diagnosis of lung lesions. It can provide similar clinical cases for physicians and help them make reliable clinical diagnostic decisions. However, when handling large-scale lung images with a general-purpose computer, traditional image retrieval methods may not be efficient. In this paper, a new retrieval framework based on a hashing method for lung nodule CT images is proposed. This method can translate high-dimensional image features into a compact hash code, so the retrieval time and required memory space can be reduced greatly. Moreover, a pruning algorithm is presented to further improve the retrieval speed, and a pruning-based decision rule is presented to improve the retrieval precision. Finally, the proposed retrieval method is validated on 2,450 lung nodule CT images selected from the public Lung Image Database Consortium (LIDC) database. The experimental results show that the proposed pruning algorithm effectively reduces the retrieval time of lung nodule CT images and improves the retrieval precision. In addition, the retrieval framework is evaluated by differentiating benign and malignant nodules, and the classification accuracy can reach 86.62%, outperforming other commonly used classification methods.

  9. Rapid Retrieval of Lung Nodule CT Images Based on Hashing and Pruning Methods

    PubMed Central

    Pan, Ling; Yuan, Jie; Wu, Lidong

    2016-01-01

    The similarity-based retrieval of lung nodule computed tomography (CT) images is an important task in the computer-aided diagnosis of lung lesions. It can provide similar clinical cases for physicians and help them make reliable clinical diagnostic decisions. However, when handling large-scale lung images with a general-purpose computer, traditional image retrieval methods may not be efficient. In this paper, a new retrieval framework based on a hashing method for lung nodule CT images is proposed. This method can translate high-dimensional image features into a compact hash code, so the retrieval time and required memory space can be reduced greatly. Moreover, a pruning algorithm is presented to further improve the retrieval speed, and a pruning-based decision rule is presented to improve the retrieval precision. Finally, the proposed retrieval method is validated on 2,450 lung nodule CT images selected from the public Lung Image Database Consortium (LIDC) database. The experimental results show that the proposed pruning algorithm effectively reduces the retrieval time of lung nodule CT images and improves the retrieval precision. In addition, the retrieval framework is evaluated by differentiating benign and malignant nodules, and the classification accuracy can reach 86.62%, outperforming other commonly used classification methods. PMID:27995140

  10. Multimedia Information Retrieval Literature Review

    SciTech Connect

    Wong, Pak C.; Bohn, Shawn J.; Payne, Deborah A.

    2010-10-12

    This survey paper highlights some of the recent, influential work in multimedia information retrieval (MIR). MIR is a branch area of multimedia (MM). The young and fast-growing area has received strong industrial and academic support in the United States and around the world (see Section 7 for a list of major conferences and journals of the community). The term "information retrieval" may be misleading to those with different computer science or information technology backgrounds. As shown in our discussion later, it indeed includes topics from user interaction, data analytics, machine learning, feature extraction, information visualization, and more.

  11. A Web Information Retrieval System

    NASA Astrophysics Data System (ADS)

    Kim, Tae-Hyun; Park, Dong-Chul; Huh, Woong; Kim, Hyen-Ug; Yoon, Chung-Hwa; Park, Chong-Dae; Woo, Dong-Min; Jeong, Taikyeong; Cho, Il-Hwan; Lee, Yunsik

    An approach for the retrieval of price information from internet sites is applied to real-world application problems in this paper. The Web Information Retrieval System (WIRS) utilizes Hidden Markov Model (HMM) for its powerful capability to process temporal information. HMM is an extremely flexible tool and has been successfully applied to a wide variety of stochastic modeling tasks. In order to compare the prices and features of products from various web sites, the WIRS extracts prices and descriptions of various products within web pages. The WIRS is evaluated with real-world problems and compared with a conventional method and the result is reported in this paper.

  12. 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).

  13. 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

  14. Text Passage Retrieval Based on Colon Classification: Retrieval Performance.

    ERIC Educational Resources Information Center

    Shepherd, Michael A.

    1981-01-01

    Reports the results of experiments using colon classification for the analysis, representation, and retrieval of primary information from the full text of documents. Recall, precision, and search length measures indicate colon classification did not perform significantly better than Boolean or simple word occurrence systems. Thirteen references…

  15. A multiagent architecture for developing medical information retrieval agents.

    PubMed

    Walczak, Steven

    2003-10-01

    Information that is available on the world wide web (WWW) is already more vast than can be comprehensibly studied by individuals and this quantity is increasing at a staggering pace. The quality of service delivered by physicians is dependent on the availability of current information. The agent paradigm offers a means for enabling physicians to filter information and retrieve only information that is relevant to current patient treatments. As with many specialized domains, agent-based information retrieval in medical domains must satisfy several domain-dependent constraints. A multiple agent architecture is developed and described in detail to efficiently provide agent-based information retrieval from the WWW and other explicit information resources. A simulation of the proposed multiple agent architecture shows a 97% decrease in information overload and an 85% increase in information relevancy over existing meta-search tools (with even larger gains over standard search engines).

  16. 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

  17. Fast phase retrieval in slightly off-axis digital holography

    NASA Astrophysics Data System (ADS)

    Zhong, Zhi; Bai, Hongyi; Shan, Mingguang; Zhang, Yabin; Guo, Lili

    2017-10-01

    In this study, three efficient algorithms are proposed for fast phase retrieval in slightly off-axis digital holography using spectrum cropping, spatial multiplexing, and complex encoding. In the first algorithm, the real spectral order of the subtracted hologram is filtered and cropped, and the number of pixels is decreased in the subsequent retrieval operations. In the second algorithm, two sequential subtracted holograms are digitally phase shifted and spatial multiplexed into one synthetic hologram, and thus only one inverse Fourier transformation is then required. In the third algorithm, two sequential subtracted holograms are encoded separately into the real part and the imaginary part of a complex hologram. Two cross-correlations can be used to reconstruct the phase, thereby improving the utilization of the spectrum. The three new algorithms speed up our previously proposed retrieval method with the assistance of specimen-free holograms. Our experiments demonstrated the validity and improved time requirements of the proposed methods.

  18. Magnetic disk architecture yielding improved retrieval and update performance

    NASA Astrophysics Data System (ADS)

    Wright, William E.

    1996-01-01

    We describe an integrated disk and file design, called IIS, and present algorithms for processing operations using this design. The operations include sequential and random retrieval, range queries, insertion, deletion, and get next record. We analyze the disk space requirements of IIS files, and the primary memory requirements. We analyze the time requirements for the various operations and give results for some examples. We show that IIS files provide 1-access random retrieval with a small transfer time, very fast sequential retrieval, efficient insertion and deletion, good storage utilization, and low primary memory requirements. We show that the IIS design is potentially superior to other popular file organizations for a wide range of realistic applications using modern technology.

  19. Retrieval of transmembrane proteins to the endoplasmic reticulum

    PubMed Central

    1993-01-01

    A COOH-terminal double lysine motif maintains type I transmembrane proteins in the ER. Proteins tagged with this motif, eg., CD8/E19 and CD4/E19, rapidly receive post-translational modifications characteristic of the intermediate compartment and partially colocalized to this organelle. These proteins also received modifications characteristic of the Golgi but much more slowly. Lectin staining localized these Golgi modified proteins to ER indicating that this motif is a retrieval signal. Differences in the subcellular distribution and rate of post-translational modification of CD8 maintained in the ER by sequences derived from a variety of ER resident proteins suggested that the efficiency of retrieval was dependent on the sequence context of the double lysine motif and that retrieval may be initiated from multiple positions along the exocytotic pathway. PMID:8468349

  20. Flexible montage retrieval for image data

    NASA Astrophysics Data System (ADS)

    Sakamoto, Hiroaki; Suzuki, Hideharu; Uemori, Akira

    1994-04-01

    Academic and photo libraries require the reuse of images. If the database is large, similarity retrieval and retrieval by sketch are effective. However, similarity retrieval can retrieve images that are similar to only one key image. Retrieval by sketch can retrieve images that are similar to the sketch, but it is not always easy to make a sketch sufficiently similar to the desired image. To overcome these limitations, we propose a new flexible montage retrieval method (FMR) that allows the user to retrieve images by appropriately combining characteristics of the key images in the same way that a montage picture of a criminal is constructed. In FMR, the user selects one or more key images and specifies areas (called `key regions') manually or by using image manipulating tools. He then indicates the retrieval conditions, for example, the requirement that the image to be retrieved includes specified areas. This paper describes an FMR algorithm that uses a color histogram and texture to quantify the similarity between a key region and an image in the database. The effectiveness of FMR is then statistically demonstrated by comparing its correct retrieval rate with that of retrieval by sketch. The retrieval rate is calculated from the result of retrieving the images that include a specified sky image from among more than 150 images containing various sky images.

  1. Embedding and retrieving private metadata in electrocardiograms.

    PubMed

    Kozat, Suleyman S; Vlachos, Michail; Lucchese, Claudio; Van Herle, Helga; Yu, Philip S

    2009-08-01

    Due to the recent explosion of 'identity theft' cases, the safeguarding of private data has been the focus of many scientific efforts. Medical data contain a number of sensitive attributes, whose access the rightful owner would ideally like to disclose only to authorized personnel. One way of providing limited access to sensitive data is through means of encryption. In this work we follow a different path, by proposing the fusion of the sensitive metadata within the medical data. Our work is focused on medical time-series signals and in particular on Electrocardiograms (ECG). We present techniques that allow the embedding and retrieval of sensitive numerical data, such as the patient's social security number or birth date, within the medical signal. The proposed technique not only allows the effective hiding of the sensitive metadata within the signal itself, but it additionally provides a way of authenticating the data ownership or providing assurances about the origin of the data. Our methodology builds upon watermarking notions, and presents the following desirable characteristics: (a) it does not distort important ECG characteristics, which are essential for proper medical diagnosis, (b) it allows not only the embedding but also the efficient retrieval of the embedded data, (c) it provides resilience and fault tolerance by employing multistage watermarks (both robust and fragile). Our experiments on real ECG data indicate the viability of the proposed scheme.

  2. 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.

  3. Use of a JPEG-2000 Wavelet Compression Scheme for Content-Based Ophtalmologic Retinal Images Retrieval.

    PubMed

    Lamard, Mathieu; Daccache, Wissam; Cazuguel, Guy; Roux, Christian; Cochener, Beatrice

    2005-01-01

    In this paper we propose a content based image retrieval method for diagnosis aid in diabetic retinopathy. We characterize images without extracting significant features, and use histograms obtained from the compressed images in JPEG-2000 wavelet scheme to build signatures. The research is carried out by calculating signature distances between the query and database images. A weighted distance between histograms is used. Retrieval efficiency is given for different standard types of JPEG-2000 wavelets, and for different values of histogram weights. A classified diabetic retinopathy image database is built allowing algorithms tests. On this image database, results are promising: the retrieval efficiency is higher than 70% for some lesion types.

  4. 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…

  5. 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.

  6. Neural networks for atmospheric retrievals

    NASA Technical Reports Server (NTRS)

    Motteler, Howard E.; Gualtieri, J. A.; Strow, L. Larrabee; Mcmillin, Larry

    1993-01-01

    We use neural networks to perform retrievals of temperature and water fractions from simulated clear air radiances for the Atmospheric Infrared Sounder (AIRS). Neural networks allow us to make effective use of the large AIRS channel set, and give good performance with noisy input. We retrieve surface temperature, air temperature at 64 distinct pressure levels, and water fractions at 50 distinct pressure levels. Using 728 temperature and surface sensitive channels, the RMS error for temperature retrievals with 0.2K input noise is 1.2K. Using 586 water and temperature sensitive channels, the mean error with 0.2K input noise is 16 percent. Our implementation of backpropagation training for neural networks on the 16,000-processor MasPar MP-1 runs at a rate of 90 million weight updates per second, and allows us to train large networks in a reasonable amount of time. Once trained, the network can be used to perform retrievals quickly on a workstation of moderate power.

  7. 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.

  8. The Intrex Retrieval System Software.

    ERIC Educational Resources Information Center

    Hurlburt, Charles E.; And Others

    The report describes the general structure of the Intrex Retrieval Systems and each of the component subroutines. The report is not an introduction to Intrex. In addition to a general description, the report covers the following topics: (1) system architecture, (2) software details, (3) command control logic, (4) list manipulation logic, (5)…

  9. Information Retrieval in the Classroom.

    ERIC Educational Resources Information Center

    Oley, Elizabeth

    1989-01-01

    Explores aspects of information retrieval skills such as end user training, indexing, controlled vocabulary systems, search protocol, boolean logic, problem analysis, and decision making. Suggests techniques for classroom instruction using simulations of online databases, CD-ROMs, and DIALOG's classroom instruction program. Describes several…

  10. 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…

  11. Information Retrieval in the Classroom.

    ERIC Educational Resources Information Center

    Oley, Elizabeth

    1989-01-01

    Explores aspects of information retrieval skills such as end user training, indexing, controlled vocabulary systems, search protocol, boolean logic, problem analysis, and decision making. Suggests techniques for classroom instruction using simulations of online databases, CD-ROMs, and DIALOG's classroom instruction program. Describes several…

  12. 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…

  13. 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…

  14. Relational Thesauri in Information Retrieval.

    ERIC Educational Resources Information Center

    Wang, Yih-Chen; Vandendorpe, James

    1985-01-01

    Describes design and development of a thesaurus based on lexical-semantic relations, and compares results of experiments with queries enhanced using thesauri based on several different groups of relations against performance with original queries run on IRS information retrieval system developed at Illinois Institute of Technology. Twenty-one…

  15. 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,…

  16. How does antigen retrieval work?

    PubMed

    Leong, Trishe Y-M; Leong, Anthony S-Y

    2007-03-01

    The introduction of antigen retrieval has enabled immunohistology to become an integral component of morphologic diagnosis, routinely employed in cancer diagnosis, and for the identification of therapeutic and prognostic markers. The mechanism of antigen retrieval, however, remains speculative with the key to our understanding embedded in the actions of formaldehyde on proteins. One commonly held concept is that heat primarily breaks down protein cross-linkages that occur with aldehyde fixation, thus "unmasking" protein epitopes of interest. Enzymatic pretreatment is also thought to have a similar action whereas such "breakages" are the result of extremely rapid molecular movement induced by microwaves and ultrasound. The formation of rigid cagelike calcium complexes during formaldehyde fixation is another suggested mechanism of antigen masking requiring chelating agents for reversal. A more recent suggestion for the antigen retrieval phenomenon has evoked the Mannich reaction, which occurs with the cross-linking of some proteins. Such cross-linkages can be hydrolyzed by heat or alkalis so that the process of antigen retrieval may be the simple removal of such cross-linked proteins that are sterically interfering with the binding of antibodies to linear protein epitopes in the tissue section. We are clearly not yet in possession of all the answers to the problem.

  17. 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,…

  18. 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…

  19. Stress disrupts response memory retrieval.

    PubMed

    Guenzel, Friederike M; Wolf, Oliver T; Schwabe, Lars

    2013-08-01

    Stress effects on memory are well-known. Most studies, however, focused on the impact of stress on hippocampus-dependent 'declarative' memory processes. Less is known about whether stress influences also striatum-based memory processes, such as stimulus-response (S-R) memory. First evidence from rodent experiments shows that glucocorticoid stress hormones may enhance the consolidation of S-R memories. Whether stress affects also S-R memory retrieval remains largely elusive. Therefore, we tested in the present experiment in humans the effect of stress on the retrieval of S-R memories. Healthy men and women were trained to locate three objects in an S-R version of a virtual eight-arm radial maze. One week later, participants underwent a stressor or a control condition before their memory of the S-R task was tested. Our results showed that participants (n=43) who were exposed to the stressor before retention testing made significantly more errors in this test trial, suggesting that stress impaired S-R memory retrieval. Moreover, high cortisol concentrations were associated with reduced S-R memory. These findings indicate that stress may affect memory retrieval processes in humans beyond hippocampal 'declarative' memory.

  20. Cross-Language Information Retrieval.

    ERIC Educational Resources Information Center

    Oard, Douglas W.; Diekema, Anne R.

    1998-01-01

    Reviews research and practice in cross-language information retrieval (CLIR) that seeks to support the process of finding documents written in one natural language with automated systems that can accept queries expressed in other languages. Addresses user needs, document preprocessing, query formulation, matching strategies, sources of translation…

  1. 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…

  2. Phase 2, Solid waste retrieval strategy

    SciTech Connect

    Johnson, D.M.

    1994-09-29

    Solid TRU retrieval, Phase 1 is scheduled to commence operation in 1998 at 218W-4C-T01 and complete recovery of the waste containers in 2001. Phase 2 Retrieval will recover the remaining buried TRU waste to be retrieved and provide the preliminary characterization by non-destructive means to allow interim storage until processing for disposal. This document reports on researching the characterization documents to determine the types of wastes to be retrieved and where located, waste configurations, conditions, and required methods for retrieval. Also included are discussions of wastes encompassed by Phase 2 for which there are valid reasons to not retrieve.

  3. 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.

  4. Breast Histopathological Image Retrieval Based on Latent Dirichlet Allocation.

    PubMed

    Ma, Yibing; Jiang, Zhiguo; Zhang, Haopeng; Xie, Fengying; Zheng, Yushan; Shi, Huaqiang; Zhao, Yu

    2016-09-20

    In the field of pathology, whole slide image (WSI) has become the major carrier of visual and diagnostic information. Content based image retrieval among WSIs can aid the diagnosis of an unknown pathological image by finding its similar regions in WSIs with diagnostic information. However, the huge size and complex content of WSI pose several challenges for retrieval. In this paper, we propose an unsupervised, accurate and fast retrieval method for breast histopathological image. Specifically, the method presents local statistical feature of nuclei for morphology and distribution of nuclei, and employs Gabor feature to describe texture information. Latent Dirichlet Allocation model is utilized for high-level semantic mining. Locality- Sensitive Hashing is used to speed up the search. Experiments on a WSI database with over 8000 images from 15 types of breast histopathology demonstrate that our method achieves about 0.9 retrieval precision as well as promising efficiency. Based on the proposed framework, we are developing a search engine for an online digital slide browsing and retrieval platform, which can be applied in computer-aided diagnosis, pathology education, WSI archiving and management.

  5. Satellite Retrieval of Aerosol Properties

    NASA Astrophysics Data System (ADS)

    de Leeuw, G.; Robles Gonzalez, C.; Kusmierczyk-Michulec, J.; Decae, R.

    SATELLITE RETRIEVAL of AEROSOL PROPERTIES G. de Leeuw, C. Robles Gonzalez, J. Kusmierczyk-Michulec and R. Decae TNO Physics and Electronics Laboratory, The Hague, The Netherlands; deleeuw@fel.tno.nl Methods to retrieve aerosol properties over land and over sea were explored. The dual view offered by the ATSR-2 aboard ERS-2 was used by Veefkind et al., 1998. The retrieved AOD (aerosol optical depth) values compare favourably with collocated sun photometer measurements, with an accuracy of 0.06 +/- 0.05 in AOD. An algorithm developed for GOME on ERS-2 takes advantage of the low surface reflection in the UV (Veefkind et al., 2000). AOD values retrieved from ATSR-2 and GOME data over western Europe are consistent. The results were used to produce a map of mean AOD values over Europe for one month (Robles-Gonzalez et al., 2000). The ATSR-2 is al- gorithm is now extended with other aerosol types with the aim to apply it over the In- dian Ocean. A new algorithm is being developed for the Ozone Monitoring Instrument (OMI) to be launched in 2003 on the NASA EOS-AURA satellite. It is expected that, based on the different scattering and absorption properties of various aerosol types, five major aerosol classes can be distinguished. The experience with the retrieval of aerosol properties by using several wavelength bands is used to develop an algorithm for Sciamachy to retrieve aerosol properties both over land and over the ocean which takes advantage of the wavelengths from the UV to the IR. The variation of the AOD with wavelength is described by the Angstrom parameter. The AOD and the Angstrom parameter together yield information on the aerosol size distribution, integrated over the column. Analysis of sunphotometer data indicates a relation between the Angstrom parameter and the mass ratio of certain aerosols (black carbon, organic carbon and sea salt) to the total particulate matter. This relation has been further explored and was applied to satellite data over land to

  6. A new method of content based medical image retrieval and its applications to CT imaging sign retrieval.

    PubMed

    Ma, Ling; Liu, Xiabi; Gao, Yan; Zhao, Yanfeng; Zhao, Xinming; Zhou, Chunwu

    2017-02-01

    This paper proposes a new method of content based medical image retrieval through considering fused, context-sensitive similarity. Firstly, we fuse the semantic and visual similarities between the query image and each image in the database as their pairwise similarities. Then, we construct a weighted graph whose nodes represent the images and edges measure their pairwise similarities. By using the shortest path algorithm over the weighted graph, we obtain a new similarity measure, context-sensitive similarity measure, between the query image and each database image to complete the retrieval process. Actually, we use the fused pairwise similarity to narrow down the semantic gap for obtaining a more accurate pairwise similarity measure, and spread it on the intrinsic data manifold to achieve the context-sensitive similarity for a better retrieval performance. The proposed method has been evaluated on the retrieval of the Common CT Imaging Signs of Lung Diseases (CISLs) and achieved not only better retrieval results but also the satisfactory computation efficiency.

  7. Supervised graph hashing for histopathology image retrieval and classification.

    PubMed

    Shi, Xiaoshuang; Xing, Fuyong; Xu, KaiDi; Xie, Yuanpu; Su, Hai; Yang, Lin

    2017-08-01

    In pathology image analysis, morphological characteristics of cells are critical to grade many diseases. With the development of cell detection and segmentation techniques, it is possible to extract cell-level information for further analysis in pathology images. However, it is challenging to conduct efficient analysis of cell-level information on a large-scale image dataset because each image usually contains hundreds or thousands of cells. In this paper, we propose a novel image retrieval based framework for large-scale pathology image analysis. For each image, we encode each cell into binary codes to generate image representation using a novel graph based hashing model and then conduct image retrieval by applying a group-to-group matching method to similarity measurement. In order to improve both computational efficiency and memory requirement, we further introduce matrix factorization into the hashing model for scalable image retrieval. The proposed framework is extensively validated with thousands of lung cancer images, and it achieves 97.98% classification accuracy and 97.50% retrieval precision with all cells of each query image used. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. 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…

  9. 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.

  10. 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…

  11. To retrieve or not to retrieve: These are the issues

    SciTech Connect

    Hyde, R.A.; Dahlmeir, M.M.; Nickelson, D.F.; Swanson, S.P.

    1997-10-01

    There are many factors that must be evaluated when determining whether a buried mixed waste site should be retrieved and subsequently stored, treated, and/or disposed of or if some other action is more appropriate. The criteria developed for the evaluation of remedial actions at mixed waste sites under Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) regulation EPA, provide an excellent methodology for deciding upon a preferred action even if the site is not under CERCLA regulation. Each topic for evaluation in the criteria is not mutually exclusive, and many tradeoffs must be reviewed. The criteria have been broken down into a number of categories: overall protection of human health and the environment; compliance with Applicable or Relevant and Appropriate Requirements (ARARs); long-term effectiveness and permanence; reduction of toxicity, mobility, and volume; short-term effectiveness; implementability; cost; state acceptance; and community acceptance. Once the data is gathered, a Hazards Analysis must be performed to understand the risks of the site to workers, the public, and the environment. The Hazard Analysis is critical in helping personnel understand the associated issues so that an effective evaluation can take place. The intent of this paper is not to focus on a particular site, but to provide information that is useful for many problem holders to better understand the issues associated with buried mixed waste retrieval. Ultimately, these issues affect the final decision of whether or not retrieval is a feasible alternative.

  12. Memory as discrimination: a challenge to the encoding-retrieval match principle.

    PubMed

    Poirier, Marie; Nairne, James S; Morin, Caroline; Zimmermann, Friederike G S; Koutmeridou, Kyriaki; Fowler, James

    2012-01-01

    Four experiments contrasted the predictions of a general encoding-retrieval match hypothesis with those of a view claiming that the distinctiveness of the cue-target relationship is the causal factor in retrieval. In Experiments 1, 2, and 4 participants learned the relationships between 4 targets and trios of cues; in Experiment 3 there were 3 targets, each associated with a pair of cues. A learning phase was followed by a cued-recognition task where the correct target had to be identified based on 1 or more of the cues. The main performance measurement was response time. Learning was designed to lead to high accuracy so effects could be attributed to retrieval efficiency rather than to variations in encoding. The nature of the cues and targets was varied across experiments. The critical factor was whether each cue was uniquely associated with the to-be-recalled target. All experiments orthogonally manipulated (a) how discriminative-or uniquely associated with a target-each cue was and (b) the degree of overlap between the cues present during learning and those present at retrieval. The novel finding reported here is that increasing the encoding-retrieval match can hinder performance if the increase simultaneously reduces how well cues predict a target-that is, a cue's diagnostic value. Encoding-retrieval match was not the factor that determined the effectiveness of retrieval. Our findings suggest that increasing the encoding-retrieval match can lead to no change, an increase, or a decrease in retrieval performance.

  13. Adapting to changing memory retrieval demands: evidence from event-related potentials.

    PubMed

    Benoit, Roland G; Werkle-Bergner, Markus; Mecklinger, Axel; Kray, Jutta

    2009-06-01

    This study investigated preparatory processes involved in adapting to changing episodic memory retrieval demands. Event-related potentials (ERPs) were recorded while participants performed a general old/new recognition task and a specific task that also required retrieval of perceptual details. The relevant task remained either constant or changed (predictably or randomly) across trials. Responses were slowed when participants switched from the specific to the general task but not vice versa. Hence, asymmetrical switch costs were observed, suggesting that retrieval preparation is dependent not only on the current retrieval goal but also influenced by recent retrieval attempts. Consistently, over posterior scalp regions ERPs associated with advance preparation were modulated by the preceding task, reflecting increased attentional selection requirements for the general task, and by the foreknowledge about the task sequence. When retrieval demands remained constant, frontal slow-waves elicited by retrieval-cues were more positive going for the specific task, indicating full implementation of a retrieval orientation that allows more efficient retrieval of perceptual details.

  14. 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

  15. 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)

  16. 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…

  17. Retrieval Processes Supporting Judgments of Recency

    ERIC Educational Resources Information Center

    Grove, Kerrie L.; Wilding, Edward L.

    2009-01-01

    The circumstances under which different retrieval processes can support judgments about how long ago events occurred remain a matter of debate, as do the ways in which retrieved information can be employed in support of such judgments. In order to contribute to an understanding of the nature and number of distinct retrieval processes that support…

  18. 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…

  19. 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…

  20. Uterus retrieval in cadaver: technical aspects.

    PubMed

    Akar, M Erman; Ozkan, O; Ozekinci, M; Sindel, M; Yildirim, F; Oguz, N

    2014-01-01

    The authors describe uterus retrieval in cadavers. Uterine retrieval with its vasculature could be successfully achieved in four of the presented cases. Special attention was given to dissection of bilateral ureters and hypogastric vasculature. Uterine retrieval with its vasculature and supporting sacrouterine,vesicouterine peritoneal folds is an anatomically feasible procedure in preparation for uterus transplantation.

  1. 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…

  2. The Networking of Interactive Bibliographic Retrieval Systems.

    ERIC Educational Resources Information Center

    Marcus, Richard S.; Reintjes, J. Francis

    Research in networking of heterogeneous interactive bibliographic retrieval systems is being conducted which centers on the concept of a virtual retrieval system. Such a virtual system would be created through a translating computer interface that would provide access to the different retrieval systems and data bases in a uniform and convenient…

  3. RETRIEVAL OF TECHNICAL DOCUMENTS. FINAL SCIENTIFIC REPORT.

    ERIC Educational Resources Information Center

    BOHNERT, LEA M.

    A RETRIEVAL MODEL WAS DEVELOPED FOR TEACHING AND RESEARCH PURPOSES ON THE BASIS OF VARIED WORK EXPERIENCE AND ANALYSIS OF TECHNICAL DOCUMENT RETRIEVAL AND LIBRARY SERVICES. THE MODEL IS BASED ON SHANNON'S COMMUNICATION MODEL BUT IDENTIFIES THE WOULD BE READER, OR DESTINATION OF RECORDED MESSAGES, AS THE ACTIVATOR OF RETRIEVAL SERVICES. TWO MAIN…

  4. 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…

  5. 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…

  6. 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…

  7. A Logic Basis for Information Retrieval.

    ERIC Educational Resources Information Center

    Watters, C. R.; Shepherd, M. A.

    1987-01-01

    Discusses the potential of recent work in artificial intelligence, especially expert systems, for the development of more effective information retrieval systems. Highlights include the role of an expert bibliographic retrieval system and a prototype expert retrieval system, PROBIB-2, that uses MicroProlog to provide deductive reasoning…

  8. Undersampled Phase Retrieval with Outliers

    PubMed Central

    Weller, Daniel S.; Pnueli, Ayelet; Divon, Gilad; Radzyner, Ori; Eldar, Yonina C.; Fessler, Jeffrey A.

    2015-01-01

    This paper proposes a general framework for reconstructing sparse images from undersampled (squared)-magnitude data corrupted with outliers and noise. This phase retrieval method uses a layered approach, combining repeated minimization of a convex majorizer (surrogate for a nonconvex objective function), and iterative optimization of that majorizer using a preconditioned variant of the alternating direction method of multipliers (ADMM). Since phase retrieval is nonconvex, this implementation uses multiple initial majorization vectors. The introduction of a robust 1-norm data fit term that is better adapted to outliers exploits the generality of this framework. The derivation also describes a normalization scheme for the regularization parameter and a known adaptive heuristic for the ADMM penalty parameter. Both 1D Monte Carlo tests and 2D image reconstruction simulations suggest the proposed framework, with the robust data fit term, reduces the reconstruction error for data corrupted with both outliers and additive noise, relative to competing algorithms having the same total computation. PMID:26770999

  9. Phase retrieval in protein crystallography.

    PubMed

    Liu, Zhong Chuan; Xu, Rui; Dong, Yu Hui

    2012-03-01

    Solution of the phase problem is central to crystallographic structure determination. An oversampling method is proposed, based on the hybrid input-output algorithm (HIO) [Fienup (1982). Appl. Opt. 21, 2758-2769], to retrieve the phases of reflections in crystallography. This method can extend low-resolution structures to higher resolution for structure determination of proteins without additional sample preparation. The method requires an envelope of the protein which divides a unit cell into the density region where the proteins are located and the non-density region occupied by solvents. After a few hundred to a few thousand iterations, the correct phases and density maps are recovered. The method has been used successfully in several cases to retrieve the phases from the experimental X-ray diffraction data and the envelopes of proteins constructed from structure files downloaded from the Protein Data Bank. It is hoped that this method will greatly facilitate the ab initio structure determination of proteins.

  10. 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.

  11. 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

  12. 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.

  13. Rapidly Retargetable Interactive Translingual Retrieval

    DTIC Science & Technology

    2001-01-01

    vocabulary beyond that which was available af- ter term-by-term translation. This is analogous to the process that Singhal et al. applied to monolingual ...Language Evaluation Forum’s (CLEF) multilingual task. We used the English language forms of the queries to retrieve English, French, German, and...tracking task was multilingual , search- ing stories in both English and Mandarin Chinese, and multi-modal, involving both newswire text and broadcast

  14. Topic Models in Information Retrieval

    DTIC Science & Technology

    2007-08-01

    the combination: Hidden Markov Model. Miller et al. (1999) presented a Hidden Markov Model ( HMM ) Information Retrieval system. They take the...combination with different methods to estimate the combination weights. The parameter estimation in the HMM framework is simplified with strict...applied a Hidden Markov Model ( HMM ) framework; Zhai and Lafferty (2002) and Cao et al. (2005) used Expectation Maximization (EM) on the mixture

  15. LOCAT - A Data Retrieval Program.

    DTIC Science & Technology

    1984-12-01

    STANDARSIA1 3 -A Suznn Y4Sl ’ś’. Doc 0 006 U m Nalionai Deftense U’" Defence nationale LOCAT -A DATA RETRIEVAL PROGRAM by Suzanne Y. Slinn SA RSA T Project...2.1 DESIGN PHILOSOPHY...................2 2.2 SATELLITE AND LOCATION SOFT KEY DISPLAY .. .. ........ 3 2.3...LOCAT -Calling Sequence .. .. ...... ........ 2 FIGURE 2: SAT/LOC Soft Key Display .. .. ...... ..... 3 FIGURE 3 : Frequency Soft Key Display

  16. 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.

  17. 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.

  18. 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…

  19. Covert Retrieval Practice Benefits Retention as Much as Overt Retrieval Practice

    ERIC Educational Resources Information Center

    Smith, Megan A.; Roediger, Henry L., III; Karpicke, Jeffrey D.

    2013-01-01

    Many experiments provide evidence that practicing retrieval benefits retention relative to conditions of no retrieval practice. Nearly all prior research has employed retrieval practice requiring overt responses, but a few experiments have shown that covert retrieval also produces retention advantages relative to control conditions. However,…

  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. 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…

  2. Multispectral vegetative canopy parameter retrieval

    NASA Astrophysics Data System (ADS)

    Borel, Christoph C.; Bunker, David J.

    2011-11-01

    Precision agriculture, forestry and environmental remote sensing are applications uniquely suited to the 8 bands that DigitalGlobe's WorldView-2 provides. At the fine spatial resolution of 0.5 m (panchromatic) and 2 m (multispectral) individual trees can be readily resolved. Recent research [1] has shown that it is possible for hyper-spectral data to invert plant reflectance spectra and estimate nitrogen content, leaf water content, leaf structure, canopy leaf area index and, for sparse canopies, also soil reflectance. The retrieval is based on inverting the SAIL (Scattering by Arbitrary Inclined Leaves) vegetation radiative transfer model for the canopy structure and the reflectance model PROSPECT4/5 for the leaf reflectance. Working on the paper [1] confirmed that a limited number of adjacent bands covering just the visible and near infrared can retrieve the parameters as well, opening up the possibility that this method can be used to analyze multi-spectral WV-2 data. Thus it seems possible to create WV-2 specific inversions using 8 bands and apply them to imagery of various vegetation covered surfaces of agricultural and environmental interest. The capability of retrieving leaf water content and nitrogen content has important applications in determining the health of vegetation, e.g. plant growth status, disease mapping, quantitative drought assessment, nitrogen deficiency, plant vigor, yield, etc.

  3. 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.

  4. 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

  5. Text encoding for retrieving scientific and technical information

    SciTech Connect

    Strehlow, R.A.; Tallant, T.O.; Mason, J.D.; Kienlen, P.L.

    1991-01-01

    The authors have recently proposed a method a manage and to retrieve scientific and technical information based on the encoding of information within the document using Standard Generalized Markup Language (SGML). The encoding will include the scientific and technical information, as well as associated and ancillary scientific data, management data, and other metadata. The work proposed at the Oak Ridge National Laboratory will include tagset selection, document type definition writing, test document encoding, and programming that will permit various views of a document to be made. This paper describes the proposed method and work. Precise retrieval of contained information is conventionally done by means of Boolean searches to retrieve a set of documents that have been probability of containing the desired information. Standardized terminologies have long been a key element in constructing efficient search plans for these searches. Combined with added techniques of corpus selection, author or institution restriction, etc., effective searches can often be constructed. With the increase in corpus size, however, the standard methods become progressively less effective. The planned method described here involves a radically different approach to the retrieval problems. Its objective is the direct retrieval of information. The work of this study will be carried out by a multi-disciplinary team of engineering, scientific, publication, and information specialists. Computer programs to retrieve information from encoded sample documents will be either acquired or written and then tested. At the final stage of the work, after evaluation of the program, plans will be developed to apply the method to a wide range of specialized fields.

  6. Text encoding for retrieving scientific and technical information

    SciTech Connect

    Strehlow, R.A.; Tallant, T.O.; Mason, J.D.; Kienlen, P.L.

    1991-12-31

    The authors have recently proposed a method a manage and to retrieve scientific and technical information based on the encoding of information within the document using Standard Generalized Markup Language (SGML). The encoding will include the scientific and technical information, as well as associated and ancillary scientific data, management data, and other metadata. The work proposed at the Oak Ridge National Laboratory will include tagset selection, document type definition writing, test document encoding, and programming that will permit various views of a document to be made. This paper describes the proposed method and work. Precise retrieval of contained information is conventionally done by means of Boolean searches to retrieve a set of documents that have been probability of containing the desired information. Standardized terminologies have long been a key element in constructing efficient search plans for these searches. Combined with added techniques of corpus selection, author or institution restriction, etc., effective searches can often be constructed. With the increase in corpus size, however, the standard methods become progressively less effective. The planned method described here involves a radically different approach to the retrieval problems. Its objective is the direct retrieval of information. The work of this study will be carried out by a multi-disciplinary team of engineering, scientific, publication, and information specialists. Computer programs to retrieve information from encoded sample documents will be either acquired or written and then tested. At the final stage of the work, after evaluation of the program, plans will be developed to apply the method to a wide range of specialized fields.

  7. 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.

  8. Initial retrieval sequence and blending strategy

    SciTech Connect

    Pemwell, D.L.; Grenard, C.E.

    1996-09-01

    This report documents the initial retrieval sequence and the methodology used to select it. Waste retrieval, storage, pretreatment and vitrification were modeled for candidate single-shell tank retrieval sequences. Performance of the sequences was measured by a set of metrics (for example,high-level waste glass volume, relative risk and schedule).Computer models were used to evaluate estimated glass volumes,process rates, retrieval dates, and blending strategy effects.The models were based on estimates of component inventories and concentrations, sludge wash factors and timing, retrieval annex limitations, etc.

  9. A content based framework for mass retrieval in mammograms

    NASA Astrophysics Data System (ADS)

    Kaur, Simranjit; Sharma, Vipul; Singh, Sukhwinder; Gupta, Savita

    2014-03-01

    In the recent years, there has been a phenomenal growth in the volume of digital mammograms produced in hospitals and medical centers. Thus, there is a need to create efficient access methods or retrieval tools to search, browse and retrieve images from large repositories to aid diagnoses and research. This paper presents a Content Based Medical Image Retrieval (CBMIR) system for mass retrieval in mammograms using a two stage framework. Also, for mass segmentation, a semi-automatic method based on Seed Region Growing approach is proposed. Shape features are extracted at the first stage to find similar shape lesions and the second stage further refines the results by finding similar pathology bearing lesions using texture features. Various shape features used in this study are Compactness, Convexity, Spicularity, Radial Distance (RD) based features, Zernike Moments (ZM) and Fourier Descriptors (FD). The texture of mass lesions is characterized by Gray Level Co-occurrence Matrix (GLCM) features, Gray Level Run Length Matrix (GLRLM) features and Fourier Power Spectrum (FPS) features. In this paper, feature selection is done by Correlation based Feature Selection (CFS) technique to select the best subset of shape and texture features as high dimensionality of feature vector may limit computational efficiency. This study used the IRMA Version of DDSM LJPEG data to evaluate the retrieval performance of various shape and texture features. From the experimental results, it has been found that the proposed CBMIR system using merely the compactness or shape features selected by CFS provided better distinction among four categories of mass shape (Round, Oval, Lobulated and Irregular) at the first stage and FPS based texture features provided better distinction between pathology (Benign and Malignant) at the second stage.

  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. 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)

  12. 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.

  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. Striatal contributions to declarative memory retrieval

    PubMed Central

    Scimeca, Jason M.; Badre, David

    2012-01-01

    Declarative memory is known to depend on the medial temporal lobe memory system. Recently, there has been renewed focus on the relationship between the basal ganglia and declarative memory, including the involvement of striatum. However, the contribution of striatum to declarative memory retrieval remains unknown. Here, we review neuroimaging and neuropsychological evidence for the involvement of the striatum in declarative memory retrieval. From this review, we propose that, along with the prefrontal cortex (PFC), the striatum primarily supports cognitive control of memory retrieval. We conclude by proposing three hypotheses for the specific role of striatum in retrieval: (1) Striatum modulates the re-encoding of retrieved items in accord with their expected utility (adaptive encoding), (2) striatum selectively admits information into working memory that is expected to increase the likelihood of successful retrieval (adaptive gating), and (3) striatum enacts adjustments in cognitive control based on the outcome of retrieval (reinforcement learning). PMID:22884322

  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.

  16. 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)

  17. 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)

  18. 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.

  19. Data mining approaches for information retrieval from genomic databases

    NASA Astrophysics Data System (ADS)

    Liu, Donglin; Singh, Gautam B.

    2000-04-01

    Sequence retrieval in genomic databases is used for finding sequences related to a query sequence specified by a user. Comparison is the main part of the retrieval system in genomic databases. An efficient sequence comparison algorithm is critical in bioinformatics. There are several different algorithms to perform sequence comparison, such as the suffix array based database search, divergence measurement, methods that rely upon the existence of a local similarity between the query sequence and sequences in the database, or common mutual information between query and sequences in DB. In this paper we have described a new method for DNA sequence retrieval based on data mining techniques. Data mining tools generally find patterns among data and have been successfully applied in industries to improve marketing, sales, and customer support operations. We have applied the descriptive data mining techniques to find relevant patterns that are significant for comparing genetic sequences. Relevance feedback score based on common patterns is developed and employed to compute distance between sequences. The contigs of human chromosomes are used to test the retrieval accuracy and the experimental results are presented.

  20. Dictionary Pruning with Visual Word Significance for Medical Image Retrieval.

    PubMed

    Zhang, Fan; Song, Yang; Cai, Weidong; Hauptmann, Alexander G; Liu, Sidong; Pujol, Sonia; Kikinis, Ron; Fulham, Michael J; Feng, David Dagan; Chen, Mei

    2016-02-12

    Content-based medical image retrieval (CBMIR) is an active research area for disease diagnosis and treatment but it can be problematic given the small visual variations between anatomical structures. We propose a retrieval method based on a bag-of-visual-words (BoVW) to identify discriminative characteristics between different medical images with Pruned Dictionary based on Latent Semantic Topic description. We refer to this as the PD-LST retrieval. Our method has two main components. First, we calculate a topic-word significance value for each visual word given a certain latent topic to evaluate how the word is connected to this latent topic. The latent topics are learnt, based on the relationship between the images and words, and are employed to bridge the gap between low-level visual features and high-level semantics. These latent topics describe the images and words semantically and can thus facilitate more meaningful comparisons between the words. Second, we compute an overall-word significance value to evaluate the significance of a visual word within the entire dictionary. We designed an iterative ranking method to measure overall-word significance by considering the relationship between all latent topics and words. The words with higher values are considered meaningful with more significant discriminative power in differentiating medical images. We evaluated our method on two public medical imaging datasets and it showed improved retrieval accuracy and efficiency.

  1. Japanese document recognition and retrieval system using programmable SIMD processor

    NASA Astrophysics Data System (ADS)

    Miyahara, Sueharu; Suzuki, Akira; Tada, Shunkichi; Kawatani, Takahiko

    1991-02-01

    This paper describes a new efficient information-filing system for a large number of documents. The system is designed to recognize Japanese characters and make full-text searches across a document database. Key components of the system are a small fully-programmable parallel processor for both recognition and retrieval an image scanner for document input and a personal computer as the operator console. The processor is constructed by a bit-serial single instruction multiple data stream architecture (SIMD) and all components including the 256 processor elements and 11 MB of RAM are integrated on one board. The recognition process divides a document into text lines isolates each character extracts character pattern features and then identifies character categories. The entire process is performed by a single micro-program package down-loaded from the console. The recognition accuracy is more than 99. 0 for about 3 printed Japanese characters at a performance speed of more than 14 characters per second. The processor can also be made available for high speed information retrieval by changing the down-loaded microprogram package. The retrieval process can obtain sentences that include the same information as an inquiry text from the database previously created through character recognition. Retrieval performance is very fast with 20 million individual Japanese characters being examined each second when the database is stored in the processor''s IC memory. It was confirmed that a high performance but flexible and cost-effective document-information-processing system

  2. Dictionary Pruning with Visual Word Significance for Medical Image Retrieval

    PubMed Central

    Zhang, Fan; Song, Yang; Cai, Weidong; Hauptmann, Alexander G.; Liu, Sidong; Pujol, Sonia; Kikinis, Ron; Fulham, Michael J; Feng, David Dagan; Chen, Mei

    2016-01-01

    Content-based medical image retrieval (CBMIR) is an active research area for disease diagnosis and treatment but it can be problematic given the small visual variations between anatomical structures. We propose a retrieval method based on a bag-of-visual-words (BoVW) to identify discriminative characteristics between different medical images with Pruned Dictionary based on Latent Semantic Topic description. We refer to this as the PD-LST retrieval. Our method has two main components. First, we calculate a topic-word significance value for each visual word given a certain latent topic to evaluate how the word is connected to this latent topic. The latent topics are learnt, based on the relationship between the images and words, and are employed to bridge the gap between low-level visual features and high-level semantics. These latent topics describe the images and words semantically and can thus facilitate more meaningful comparisons between the words. Second, we compute an overall-word significance value to evaluate the significance of a visual word within the entire dictionary. We designed an iterative ranking method to measure overall-word significance by considering the relationship between all latent topics and words. The words with higher values are considered meaningful with more significant discriminative power in differentiating medical images. We evaluated our method on two public medical imaging datasets and it showed improved retrieval accuracy and efficiency. PMID:27688597

  3. Study of Query Expansion Techniques and Their Application in the Biomedical Information Retrieval

    PubMed Central

    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. PMID:24723793

  4. 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.

  5. Six sigma for revenue retrieval.

    PubMed

    Plonien, Cynthia

    2013-01-01

    Deficiencies in revenue retrieval due to failures in obtaining charges have contributed to a negative bottom line for numerous hospitals. Improving documentation practices through a Six Sigma process improvement initiative can minimize opportunities for errors through reviews and instill structure for compliance and consistency. Commitment to the Six Sigma principles with continuous monitoring of outcomes and constant communication of results to departments, management, and payers is a strong approach to reducing the financial impact of denials on an organization's revenues and expenses. Using Six Sigma tools can help improve the organization's financial performance not only for today, but also for health care's uncertain future.

  6. Solar Occultation Retrieval Algorithm Development

    NASA Technical Reports Server (NTRS)

    Lumpe, Jerry D.

    2004-01-01

    This effort addresses the comparison and validation of currently operational solar occultation retrieval algorithms, and the development of generalized algorithms for future application to multiple platforms. initial development of generalized forward model algorithms capable of simulating transmission data from of the POAM II/III and SAGE II/III instruments. Work in the 2" quarter will focus on: completion of forward model algorithms, including accurate spectral characteristics for all instruments, and comparison of simulated transmission data with actual level 1 instrument data for specific occultation events.

  7. 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.

  8. 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.

  9. Quantum memory in an orthogonal geometry of silenced echo retrieval

    NASA Astrophysics Data System (ADS)

    Gerasimov, K. I.; Minnegaliev, M. M.; Moiseev, S. A.; Urmancheev, R. V.; Chanelière, T.; Louchet-Chauvet, A.

    2017-08-01

    We experimentally realize a quantum-memory protocol based on retrieval of silenced echo (ROSE) in Tm3+:Y3Al5O12 crystal in an orthogonal geometry of the signal and control light fields. The silenced echo signal revival efficiency of 13% with 36 μs storage time is demonstrated. To achieve that we implemented a high-precision atomic coherence control via amplitude- and phase-modulated laser pulses. We also discuss capabilities of this configuration, ways to increase quantum efficiency and to combine it with a single-mode optical cavity.

  10. JPEG2000 compressed domain image retrieval using context labels of significance coding and wavelet autocorrelogram

    NASA Astrophysics Data System (ADS)

    Angkura, Navin; Aramvith, Supavadee; Siddhichai, Supakorn

    2007-09-01

    JPEG has been a widely recognized image compression standard for many years. Nevertheless, it faces its own limitations as compressed image quality degrades significantly at lower bit rates. This limitation has been addressed in JPEG2000 which also has a tendency to replace JPEG, especially in the storage and retrieval applications. To efficiently and practically index and retrieve compressed-domain images from a database, several image features could be extracted directly in compressed domain without having to fully decompress the JPEG2000 images. JPEG2000 utilizes wavelet transform. Wavelet transforms is one of widely-used to analyze and describe texture patterns of image. Another advantage of wavelet transform is that one can analyze textures with multiresolution and can classify directional texture pattern information into each directional subband. Where as, HL subband implies horizontal frequency information, LH subband implies vertical frequency information and HH subband implies diagonal frequency. Nevertheless, many wavelet-based image retrieval approaches are not good tool to use directional subband information, obtained by wavelet transforms, for efficient directional texture pattern classification of retrieved images. This paper proposes a novel image retrieval technique in JPEG2000 compressed domain using image significant map to compute an image context in order to construct image index. Experimental results indicate that the proposed method can effectively differentiate and categorize images with different texture directional information. In addition, an integration of the proposed features with wavelet autocorrelogram also showed improvement in retrieval performance using ANMRR (Average Normalized Modified Retrieval Rank) compared to other known methods.

  11. Rotation invariant texture retrieval considering the scale dependence of Gabor wavelet.

    PubMed

    Chaorong Li; Guiduo Duan; Fujin Zhong

    2015-08-01

    Obtaining robust and efficient rotation-invariant texture features in content-based image retrieval field is a challenging work. We propose three efficient rotation-invariant methods for texture image retrieval using copula model based in the domains of Gabor wavelet (GW) and circularly symmetric GW (CSGW). The proposed copula models use copula function to capture the scale dependence of GW/CSGW for improving the retrieval performance. It is well known that the Kullback-Leibler distance (KLD) is the commonly used similarity measurement between probability models. However, it is difficult to deduce the closed-form of KLD between two copula models due to the complexity of the copula model. We also put forward a kind of retrieval scheme using the KLDs of marginal distributions and the KLD of copula function to calculate the KLD of copula model. The proposed texture retrieval method has low computational complexity and high retrieval precision. The experimental results on VisTex and Brodatz data sets show that the proposed retrieval method is more effective compared with the state-of-the-art methods.

  12. 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.

  13. Older Adults' Use of Retrieval Strategies in Everyday Life.

    PubMed

    Frank, David J; Jordano, Megan L; Browne, Kelly; Touron, Dayna R

    2016-01-01

    Despite declines in cognitive abilities, older adults often perform comparable to younger adults in everyday tasks [J Am Geriatr Soc 1999;47:172-183]. Older adults may compensate for cognitive declines by using more efficient strategies. People often improve their efficiency by switching from an algorithmic strategy where information is computed or looked-up, to a strategy where the information is retrieved directly from memory [J Exp Psychol Gen 1988;117:258-275]. However, older adults are reluctant to shift from algorithmic strategies to retrieval strategies in the laboratory, and this reluctance to use retrieval is driven by both bottom-up (slower learning) and top-down influences (memory confidence, motivation to be quick/accurate) [Psychol Aging 2004;19:452-466; Mem Cognit 2004;32:298-310]. We investigated whether bottom-up and top-down factors influence younger and older adults' decisions to use retrieval-based or algorithmic strategies in everyday life. In two studies, participants completed a daily diary for 5 (study 1) or 7 (study 2) days. Participants were asked if and how they completed daily activities within several everyday task domains. They also indicated for how long and how often they completed the specific activity (bottom-up factors), as well as how confident they were in using their memory and how motivated they were to perform the specific activity quickly and accurately (top-down influences). Both studies provided evidence for bottom-up and top-down influences. Additionally, study 2 found that top-down factors (memory confidence and motivation to be quick) were more important for older compared to younger adults. These results indicate that strategy choices influence older adults' cognitive efficiency in everyday as well as laboratory learning. © 2016 S. Karger AG, Basel.

  14. 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.

  15. Biomedical information retrieval across languages.

    PubMed

    Daumke, Philipp; Markü, Kornél; Poprat, Michael; Schulz, Stefan; Klar, Rüdiger

    2007-06-01

    This work presents a new dictionary-based approach to biomedical cross-language information retrieval (CLIR) that addresses many of the general and domain-specific challenges in current CLIR research. Our method is based on a multilingual lexicon that was generated partly manually and partly automatically, and currently covers six European languages. It contains morphologically meaningful word fragments, termed subwords. Using subwords instead of entire words significantly reduces the number of lexical entries necessary to sufficiently cover a specific language and domain. Mediation between queries and documents is based on these subwords as well as on lists of word-n-grams that are generated from large monolingual corpora and constitute possible translation units. The translations are then sent to a standard Internet search engine. This process makes our approach an effective tool for searching the biomedical content of the World Wide Web in different languages. We evaluate this approach using the OHSUMED corpus, a large medical document collection, within a cross-language retrieval setting.

  16. Endoscopic retrieval of gastric trichophytobezoar

    PubMed Central

    Zhao, Jiu-ling; Zhao, Wei-chuan; Wang, Yu-shui

    2017-01-01

    Abstract Rationale: Trichophytobezoars, which are composed of hair and plant fibers, are usually located in the stomach. They are often associated with trichophagia and trichotillomania. The most commonly reported methods of trichophytobezoar treatment are open surgery and laparoscopic retrieval; there are few reports of endoscopic removal of trichophytobezoars. Patient concerns and Diagnoses: Twelve-year-old girl presented with a 3-day history of increasing upper abdominal pain, anorexia, and postprandial emesis. She had a 3-year history of pulling out and eating her own hair. Endoscopic examination showed a large intragastric trichophytobezoar measuring 10.5 cm × 3.5 cm in size, with extension of a few hairs through the pylorus. Interventions and Outcomes: The trichophytobezoar was packed with hair fibers and contained a hard core of mixed hair and vegetable fibers. After the core was cut, the trichophytobezoar was fragmented into pieces with the alternating use of a polypectomy snare and argon plasma coagulation. A small amount of hair and nondigestible food fibers was removed with grasping forceps during the initial procedure. The remaining hairball was loosened with biopsy forceps and was injected with sodium bicarbonate solution. The trichophytobezoar was removed completely at repeat endoscopy 5 days later. After 6 months of psychological intervention, the patient had no recurrence of trichophagia or trichophytobezoar. Lessons: Endoscopy with sodium bicarbonate injection is an effective and minimally invasive method of retrieving a gastric trichophytobezoar. PMID:28099364

  17. Retrieving fear memories, as time goes by…

    PubMed Central

    Do Monte, Fabricio H.; Quirk, Gregory J.; Li, Bo; Penzo, Mario A.

    2016-01-01

    Fear conditioning researches have led to a comprehensive picture of the neuronal circuit underlying the formation of fear memories. In contrast, knowledge about 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 clarity and raise awareness on 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 after conditioning. We focus on the temporal recruitment of the paraventricular nucleus of the thalamus, and its BDNFergic efferents to the central nucleus of the amygdala, for the retrieval and maintenance of fear memories. Finally, we speculate as to why retrieval circuits change across time, and the functional benefits of recruiting structures such as the paraventricular nucleus into the retrieval circuit. PMID:27217148

  18. 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.

  19. Scalable ranked retrieval using document images

    NASA Astrophysics Data System (ADS)

    Jain, Rajiv; Oard, Douglas W.; Doermann, David

    2013-12-01

    Despite the explosion of text on the Internet, hard copy documents that have been scanned as images still play a significant role for some tasks. The best method to perform ranked retrieval on a large corpus of document images, however, remains an open research question. The most common approach has been to perform text retrieval using terms generated by optical character recognition. This paper, by contrast, examines whether a scalable segmentation-free image retrieval algorithm, which matches sub-images containing text or graphical objects, can provide additional benefit in satisfying a user's information needs on a large, real world dataset. Results on 7 million scanned pages from the CDIP v1.0 test collection show that content based image retrieval finds a substantial number of documents that text retrieval misses, and that when used as a basis for relevance feedback can yield improvements in retrieval effectiveness.

  20. 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.

  1. 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.

  2. Retrieval-induced forgetting is retrieval-modality specific: Evidence from motor memory.

    PubMed

    Tempel, Tobias; Frings, Christian

    2017-05-01

    Three experiments examined the impact of matching retrieval modality at retrieval practice and at test on retrieval-induced forgetting. Participants learned sequential finger movements to be performed either with the left or with the right index finger. Subsequently, they selectively practiced half the items of one hand. A final recall test then assessed memory for all initially learned items. We contrasted different retrieval modalities. In Experiment 1, retrieval practice pertained to motor responses in one experimental condition but it pertained to visual sequence displays in another condition. The final recall test was motoric in both conditions. In Experiment 2, retrieval practice always pertained to visual sequence displays but the final recall test either pertained to motor responses or to visual sequence displays. Retrieval-induced forgetting emerged only when the modality of the final recall test matched the modality of retrieval practice. In Experiment 3, retrieval practice either involved executing motor sequences with the same finger as in the learning phase or participants had to use the opposite hand for indicating sequences. An effector change for retrieval practice eliminated retrieval-induced forgetting in a test requiring the execution of motor sequences again with the same finger as in the learning phase. We suggest that retrieval-induced forgetting occurred as a consequence of retrieval-modality-specific inhibition.

  3. 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.

  4. Towards Adaptive High-Resolution Images Retrieval Schemes

    NASA Astrophysics Data System (ADS)

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

    2016-10-01

    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.

  5. 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.

  6. Perception-based shape retrieval for 3D building models

    NASA Astrophysics Data System (ADS)

    Zhang, Man; Zhang, Liqiang; Takis Mathiopoulos, P.; Ding, Yusi; Wang, Hao

    2013-01-01

    With the help of 3D search engines, a large number of 3D building models can be retrieved freely online. A serious disadvantage of most rotation-insensitive shape descriptors is their inability to distinguish between two 3D building models which are different at their main axes, but appear similar when one of them is rotated. To resolve this problem, we present a novel upright-based normalization method which not only correctly rotates such building models, but also greatly simplifies and accelerates the abstraction and the matching of building models' shape descriptors. Moreover, the abundance of architectural styles significantly hinders the effective shape retrieval of building models. Our research has shown that buildings with different designs are not well distinguished by the widely recognized shape descriptors for general 3D models. Motivated by this observation and to further improve the shape retrieval quality, a new building matching method is introduced and analyzed based on concepts found in the field of perception theory and the well-known Light Field descriptor. The resulting normalized building models are first classified using the qualitative shape descriptors of Shell and Unevenness which outline integral geometrical and topological information. These models are then put in on orderly fashion with the help of an improved quantitative shape descriptor which we will term as Horizontal Light Field Descriptor, since it assembles detailed shape characteristics. To accurately evaluate the proposed methodology, an enlarged building shape database which extends previous well-known shape benchmarks was implemented as well as a model retrieval system supporting inputs from 2D sketches and 3D models. Various experimental performance evaluation results have shown that, as compared to previous methods, retrievals employing the proposed matching methodology are faster and more consistent with human recognition of spatial objects. In addition these performance

  7. Elaborative retrieval: Do semantic mediators improve memory?

    PubMed

    Lehman, Melissa; Karpicke, Jeffrey D

    2016-10-01

    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 retrieval than during restudy and that the generation of mediators facilitates later recall of targets. Although these assumptions are often discussed in the context of retrieval processes, we noted that there was little prior empirical evidence to support either assumption. We conducted a series of experiments to measure the generation of mediators during retrieval and restudy and to examine the effect of the generation of mediators on later target recall. Across 7 experiments, we found that the generation of mediators was not more likely during retrieval (and may be more likely during restudy), and that the activation of mediators was unrelated to subsequent free recall of targets and was negatively related to cued recall of targets. The results pose challenges for both assumptions of the elaborative retrieval account. (PsycINFO Database Record

  8. Wellhead bowl protector and retrieving tool

    SciTech Connect

    Young, J.A.

    1991-09-03

    This patent describes improvement in a wellhead protection system including a wear bushing and a retrieving tool. The improvement comprises a wear bushing supported within the wellhead, wherein the wear bushing includes an enlarged upper end having an external support shoulder for engagement with an internal support shoulder formed in the wellhead; wherein the wear bushing further includes an internal circumferential slot intersected by at least one vertically extending slot, the vertical slot extending from the circumferential slot to the upper end of the wear bushing; a retrieving tool having at least one outwardly biased, retractable lug member mounted thereon; and wherein the retrieving tool includes an enlarged portion adapted to be received within the enlarged upper end of the wear bushing. This patent also describes a method of retrieving a wear bushing from a wellhead comprising the steps of: lowering a retrieving tool into the wellhead for locking engagement with the wear bushing; aligning the retrieving tool with the wear bushing for automatically forcing lug members carried by the retrieving tool outwardly into locking engagement with the wear bushing; monitoring drill string weight for determining engagement of the retrieving tool with the wear bushing, wherein a substantial decrease in drill string weight is an indication that the retrieving tool is engaged with the wear bushing; and removing the wear bushing from the wellhead.

  9. 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.)

  10. 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.)

  11. Evaluation of AERONET Aerosol Retrievals

    NASA Astrophysics Data System (ADS)

    Schuster, G. L.; Dubovik, O.; Rutledge, C. K.

    2001-12-01

    The aerosol robotic network (AERONET) program provides aerosol retrievals at ground-based sunphotometer sites throughout the world. The aerosol size distributions and refractive index retrievals at two locations have been converted to phase functions and single-scattering albedo using Mie theory. These optical properties are incorporated into a discrete-ordinates radiative transfer model and calculations are compared to independent measurements obtained at the surface. The independent measurements include principle plane radiances from sunphotometer data and narrowband irradiances from multi-filter rotating shadowband radiometer (MFRSR) and rotating shadowband spectroradiometer (RSS) data. The two locations represent radically different environments. The Atmospheric Radiation Measurement (ARM) program Central Facility (CF) represents a rural continental environment, while the CERES (Clouds and the Earth's Radiant Energy System) Ocean Validation Experiment (COVE) site represents a coastal marine environment. Both sites exhibit good agreement between the model calculations and the principle plane radiances for the year 2000 (generally better than 15 percent at optical depths greater than 0.1). A comparison with RSS measurements in July 2000 at the ARM Central Facility shows an irradiance error of 12 percent or better at tested wavelenghs longer than 500 nm. Comparisons with MFRSR data fared less well, however, indicating a discrepancy between the instruments. Inspection of 28 whole-sky imager (WSI) files coincidental with all AERONET quality-controlled retrievals during 7 days reveals that no clouds were obstructing the almucantar field of view and that indeed the whole sky was clear during this period, indicating a degree of robustness in the AERONET cloud screening. Additionally, the size distributions were evaluated at COVE with hourly-averaged wind speed and direction. Linear regression indicates that the coarse mode column-integrated surface area increases from

  12. 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.

  13. 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.

  14. 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.

  15. PNRS: personalized news retrieval system

    NASA Astrophysics Data System (ADS)

    Dimitrova, Nevenka; Elenbaas, Herman; McGee, Thomas

    1999-08-01

    Personal News Retrieval System is a client-server application that delivers news segments on demand in a variety of information networks. At the server side, the news stories are segmented out from the digitized TV broadcast then classified and filtered based on consumers' preferences. At the client side, the user can access the preferred video news through the Web and watch stored video news in preferred order. Browsing preferences can be set based on anchorperson, broadcaster, category, location, top- stories and keywords. This system can be used to set up a news service run by content providers or independent media distribution companies. However, in the news era of enhanced PC/TV appliances, it is foreseeable that the whole system can run in the living room on a personal device. This paper describes the chosen server architecture, limitation of the system and solutions that can be implemented in the future.

  16. Iterative phase retrieval without support.

    PubMed

    Wu, J S; Weierstall, U; Spence, J C H; Koch, C T

    2004-12-01

    An iterative phase retrieval method for nonperiodic objects has been developed from the charge-flipping algorithm proposed in crystallography. A combination of the hybrid input-output (HIO) algorithm and the flipping algorithm has greatly improved performance. In this combined algorithm the flipping algorithm serves to find the support (object boundary) dynamically, and the HIO part improves convergence and moves the algorithm out of local minima. It starts with a single intensity measurement in the Fourier domain and does not require a priori knowledge of the support in the image domain. This method is suitable for general image recovery from oversampled diffuse elastic x-ray and electron-diffraction intensities. The relationship between this algorithm and the output-output algorithm is elucidated.

  17. Iterative phase retrieval without support

    NASA Astrophysics Data System (ADS)

    Wu, J. S.; Weierstall, U.; Spence, J. C. H.; Koch, C. T.

    2004-12-01

    An iterative phase retrieval method for nonperiodic objects has been developed from the charge-flipping algorithm proposed in crystallography. A combination of the hybrid input-output (HIO) algorithm and the flipping algorithm has greatly improved performance. In this combined algorithm the flipping algorithm serves to find the support (object boundary) dynamically, and the HIO part improves convergence and moves the algorithm out of local minima. It starts with a single intensity measurement in the Fourier domain and does not require a priori knowledge of the support in the image domain. This method is suitable for general image recovery from oversampled diffuse elastic x-ray and electron-diffraction intensities. The relationship between this algorithm and the output-output algorithm is elucidated.

  18. Optimizing CALIPSO Saharan dust retrievals

    NASA Astrophysics Data System (ADS)

    Amiridis, V.; Wandinger, U.; Marinou, E.; Giannakaki, E.; Tsekeri, A.; Basart, S.; Kazadzis, S.; Gkikas, A.; Taylor, M.; Baldasano, J.; Ansmann, A.

    2013-12-01

    We demonstrate improvements in CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) dust extinction retrievals over northern Africa and Europe when corrections are applied regarding the Saharan dust lidar ratio assumption, the separation of the dust portion in detected dust mixtures, and the averaging scheme introduced in the Level 3 CALIPSO product. First, a universal, spatially constant lidar ratio of 58 sr instead of 40 sr is applied to individual Level 2 dust-related backscatter products. The resulting aerosol optical depths show an improvement compared with synchronous and collocated AERONET (Aerosol Robotic Network) measurements. An absolute bias of the order of -0.03 has been found, improving on the statistically significant biases of the order of -0.10 reported in the literature for the original CALIPSO product. When compared with the MODIS (Moderate-Resolution Imaging Spectroradiometer) collocated aerosol optical depth (AOD) product, the CALIPSO negative bias is even less for the lidar ratio of 58 sr. After introducing the new lidar ratio for the domain studied, we examine potential improvements to the climatological CALIPSO Level 3 extinction product: (1) by introducing a new methodology for the calculation of pure dust extinction from dust mixtures and (2) by applying an averaging scheme that includes zero extinction values for the nondust aerosol types detected. The scheme is applied at a horizontal spatial resolution of 1° × 1° for ease of comparison with the instantaneous and collocated dust extinction profiles simulated by the BSC-DREAM8b dust model. Comparisons show that the extinction profiles retrieved with the proposed methodology reproduce the well-known model biases per subregion examined. The very good agreement of the proposed CALIPSO extinction product with respect to AERONET, MODIS and the BSC-DREAM8b dust model makes this dataset an ideal candidate for the provision of an accurate and robust multiyear dust

  19. Optimizing Saharan dust CALIPSO retrievals

    NASA Astrophysics Data System (ADS)

    Amiridis, V.; Wandinger, U.; Marinou, E.; Giannakaki, E.; Tsekeri, A.; Basart, S.; Kazadzis, S.; Gkikas, A.; Taylor, M.; Baldasano, J.; Ansmann, A.

    2013-06-01

    We demonstrate improvements in CALIPSO dust extinction retrievals over North Africa and Europe when corrections are applied regarding the Saharan dust lidar ratio assumption, the separation of dust portion in detected dust mixtures, and the averaging scheme introduced in the Level 3 CALIPSO product. First, a universal, spatially constant lidar ratio of 58 sr instead of 40 sr is applied to individual Level 2 dust-related backscatter products. The resulting aerosol optical depths show an improvement compared with synchronous and co-located AERONET measurements. An absolute bias of the order of -0.03 has been found, improving on the statistically significant biases of the order of -0.10 reported in the literature for the original CALIPSO product. When compared with the MODIS co-located AOD product, the CALIPSO negative bias is even less for the lidar ratio of 58 sr. After introducing the new lidar ratio for the domain studied, we examine potential improvements to the climatological CALIPSO Level 3 extinction product: (1) by introducing a new methodology for the calculation of pure dust extinction from dust mixtures and (2) by applying an averaging scheme that includes zero extinction values for the non-dust aerosol types detected. The scheme is applied at a horizontal spatial resolution of 1° × 1° for ease of comparison with the instantaneous and co-located dust extinction profiles simulated by the BSC-DREAM8b dust model. Comparisons show that the extinction profiles retrieved with the proposed methodology reproduce the well-known model biases per sub-region examined. The very good agreement of the proposed CALIPSO extinction product with respect to AERONET, MODIS and the BSC-DREAM8b dust model, makes this dataset an ideal candidate for the provision of an accurate and robust multi-year dust climatology over North Africa and Europe.

  20. 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

  1. 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)

  2. Enhanced Antigen Retrieval of Amyloid β Immunohistochemistry

    PubMed Central

    Kai, Hideaki; Ogino, Koichi; Hatsuta, Hiroyuki; Murayama, Shigeo; Kitamoto, Tetsuyuki

    2012-01-01

    Senile plaques, extracellular deposits of amyloid β peptide (Aβ), are one of the pathological hallmarks of Alzheimer disease (AD). As the standard immunohistochemical detection method for Aβ deposits, anti-Aβ immunohistochemistry combined with antigen retrieval (AR) by formic acid (FA) has been generally used. Here, we present a more efficient AR for Aβ antigen. On brain sections of AD and its mouse model, a double combination of either autoclave heating in EDTA buffer or digestion with proteinase K plus FA treatment reinforced Aβ immunoreactivity. A further triple combination of digestion with proteinase K (P), autoclave heating in EDTA buffer (A), and FA treatment (F), when employed in this order, gave a more enhanced immunoreactivity. Our PAF method prominently visualized various forms of Aβ deposits in AD that have not been clearly detected previously and revealed numerous minute-sized plaques both in AD and the mouse model. Quantification of Aβ loads showed that the AR effect by the PAF method was 1.86-fold (in the aged human brain) and 4.64-fold (in the mouse brain) higher than that by the FA method. Thus, the PAF method could have the potential to be the most sensitive tool so far to study Aβ pathology in AD and its mouse model. PMID:22821668

  3. 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.

  4. 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.

  5. Improving information retrieval in functional analysis.

    PubMed

    Rodriguez, Juan C; González, Germán A; Fresno, Cristóbal; Llera, Andrea S; Fernández, Elmer A

    2016-12-01

    Transcriptome analysis is essential to understand the mechanisms regulating key biological processes and functions. The first step usually consists of identifying candidate genes; to find out which pathways are affected by those genes, however, functional analysis (FA) is mandatory. The most frequently used strategies for this purpose are Gene Set and Singular Enrichment Analysis (GSEA and SEA) over Gene Ontology. Several statistical methods have been developed and compared in terms of computational efficiency and/or statistical appropriateness. However, whether their results are similar or complementary, the sensitivity to parameter settings, or possible bias in the analyzed terms has not been addressed so far. Here, two GSEA and four SEA methods and their parameter combinations were evaluated in six datasets by comparing two breast cancer subtypes with well-known differences in genetic background and patient outcomes. We show that GSEA and SEA lead to different results depending on the chosen statistic, model and/or parameters. Both approaches provide complementary results from a biological perspective. Hence, an Integrative Functional Analysis (IFA) tool is proposed to improve information retrieval in FA. It provides a common gene expression analytic framework that grants a comprehensive and coherent analysis. Only a minimal user parameter setting is required, since the best SEA/GSEA alternatives are integrated. IFA utility was demonstrated by evaluating four prostate cancer and the TCGA breast cancer microarray datasets, which showed its biological generalization capabilities. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. 3D HUMAN MOTION RETRIEVAL BASED ON HUMAN HIERARCHICAL INDEX STRUCTURE

    PubMed Central

    Guo, X.

    2013-01-01

    With the development and wide application of motion capture technology, the captured motion data sets are becoming larger and larger. For this reason, an efficient retrieval method for the motion database is very important. The retrieval method needs an appropriate indexing scheme and an effective similarity measure that can organize the existing motion data well. In this paper, we represent a human motion hierarchical index structure and adopt a nonlinear method to segment motion sequences. Based on this, we extract motion patterns and then we employ a fast similarity measure algorithm for motion pattern similarity computation to efficiently retrieve motion sequences. The experiment results show that the approach proposed in our paper is effective and efficient. PMID:24744481

  7. Indexing and Retrieval Performance: The Logical Evidence.

    ERIC Educational Resources Information Center

    Soergel, Dagobert

    1994-01-01

    Presents a logical analysis of the characteristics of indexing and their effects on retrieval. The foundational questions of performance evaluation and the basic quantitative performance measures for binary noninteractive retrieval systems are established. The effects of indexing devices, indexing exhaustivity, specificity, correctness, and…

  8. The Future of Indexing and Retrieval Vocabularies.

    ERIC Educational Resources Information Center

    Klingbiel, Paul H.

    The role of formal, controlled vocabularies for indexing and retrieval is contrasted with the use of natural language for these activities. The following credo is advanced for large central information processors as appropriate to the 1970's (1) Highly structured controlled vocabularies are obsolete for indexing and retrieval; (2) The natural…

  9. 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)…

  10. 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…

  11. Comparing Retrieval Performance in Online Data Bases.

    ERIC Educational Resources Information Center

    McCain, Katherine W.; And Others

    1987-01-01

    Assesses the impact of current coverage and indexing policies on MEDLINE's retrieval performance in the medical behavioral sciences literature by comparing retrievals in EXCERPTA MEDICA, PSYCHINFO, SCISEARCH, and SOCIAL SCISEARCH. Searches were made with descriptors, cited references, and natural language, and recall, precision, and novelty ratios…

  12. 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…

  13. 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…

  14. 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)

  15. 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…

  16. 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…

  17. 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…

  18. 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…

  19. 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…

  20. Advanced Feedback Methods in Information Retrieval.

    ERIC Educational Resources Information Center

    Salton, G.; And Others

    1985-01-01

    In this study, automatic feedback techniques are applied to Boolean query statements in online information retrieval to generate improved query statements based on information contained in previously retrieved documents. Feedback operations are carried out using conventional Boolean logic and extended logic. Experimental output is included to…

  1. Experiments in Multi-Lingual Information Retrieval.

    ERIC Educational Resources Information Center

    Salton, Gerard

    A comparison was made of the performance in an automatic information retrieval environment of user queries and document abstracts available in natural language form in both English and French. The results obtained indicate that the automatic indexing and retrieval techniques actually used appear equally effective in handling the query and document…

  2. Retrieval Testing with Hypergeometric Document Models.

    ERIC Educational Resources Information Center

    Wilbur, W. John

    1993-01-01

    Presents a method of modeling the relevance relationship in information retrieval to answer the question of the theoretical limits of certain statistical methods. Hypergeometric probability distribution is used to construct an abstract model of a database of MEDLINE records, and results of tests of vector retrieval methods are reported. (28…

  3. 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…

  4. 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…

  5. Relevance and Retrieval Evaluation: Perspectives from Medicine.

    ERIC Educational Resources Information Center

    Hersh, William

    1994-01-01

    Discusses topical relevance and situational relevance, which takes into account the impact of the retrieval system on the user, in the context of medicine. Topics addressed include scientific validity; limitations of current evaluation methodology, including recall and precision; and a framework for future retrieval research based on an…

  6. 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…

  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. 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;…

  9. 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…

  10. Relevance and Retrieval Evaluation: Perspectives from Medicine.

    ERIC Educational Resources Information Center

    Hersh, William

    1994-01-01

    Discusses topical relevance and situational relevance, which takes into account the impact of the retrieval system on the user, in the context of medicine. Topics addressed include scientific validity; limitations of current evaluation methodology, including recall and precision; and a framework for future retrieval research based on an…

  11. 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)

  12. 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…

  13. Relation of Resemblance in Information Retrieval.

    ERIC Educational Resources Information Center

    Pietilainen, Pirkko

    1982-01-01

    Presents a method for using the amount of semantic information in search-query terms as a weighting factor in constructing a fuzzy relation of resemblance between retrieved items in information retrieval online. Two tables, two figures, and a reference list accompany the text. (Author/JL)

  14. 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;…

  15. 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…

  16. 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…

  17. 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…

  18. The Future of Indexing and Retrieval Vocabularies.

    ERIC Educational Resources Information Center

    Klingbiel, Paul H.

    The role of formal, controlled vocabularies for indexing and retrieval is contrasted with the use of natural language for these activities. The following credo is advanced for large central information processors as appropriate to the 1970's (1) Highly structured controlled vocabularies are obsolete for indexing and retrieval; (2) The natural…

  19. 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…

  20. 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…

  1. 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…

  2. 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…

  3. 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

  4. Content based sub-image retrieval system for high resolution pathology images using salient interest points.

    PubMed

    Mehta, Neville; Alomari, Raja' S; Chaudhary, Vipin

    2009-01-01

    Content-based image retrieval systems for digital pathology require sub-image retrieval rather than the whole image retrieval for the system to be of clinical use. Digital pathology images are huge in size and thus the pathologist is interested in retrieving specific structures from the whole images in the database along with the previous diagnosis of the retrieved sub-image. We propose a content-based sub-image retrieval system (sCBIR) framework for high resolution digital pathology images. We utilize scale-invariant feature extraction and present an efficient and robust searching mechanism for indexing the images as well as for query execution of sub-image retrieval. We present a working sCBIR system and show results of testing our system on a set of queries for specific structures of interest for pathologists in clinical use. The outcomes of the sCBIR system are compared to manual search and there is an 80% match in the top five searches.

  5. Age differences in strategy shift: retrieval avoidance or general shift reluctance?

    PubMed

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

    2013-09-01

    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 attending to only that part of the stimulus. We adapted the AVT to include conditions that 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.

  6. Factors influencing sperm retrieval following testicular sperm extraction in nonobstructive azoospermia patients.

    PubMed

    Salehi, Peyman; Derakhshan-Horeh, Marzieh; Nadeali, Zakiye; Hosseinzadeh, Majid; Sadeghi, Erfan; Izadpanahi, Mohammad Hossein; Salehi, Mansour

    2017-03-01

    Azoospermia owing to testicular disorders is the most severe manifestation of male infertility. The main concern for patients with nonobstructive azoospermia (NOA) is the probability of successful sperm retrieval following testicular sperm extraction (TESE). Therefore, the goal of this study was to determine predictive factors correlated with sperm retrieval. We assessed the testicular histopathological patterns, the choice of TESE surgical procedure, hormone levels, and chromosomal abnormalities in patients with NOA (n=170). The histopathology specimens were analyzed based on the histopathological patterns of hypospermatogenesis, maturation arrest, and Sertoli cell-only syndrome. The mean rate of sperm retrieval was 48.8%. The rate of sperm retrieval was significantly higher in the hypospermatogenesis group than in the other groups (p<0.001). There was a positive correlation between micro-TESE (vs. conventional TESE) and the sperm retrieval rate (odds ratio, 8.077; p<0.01). A logistic regression model demonstrated that high levels of follicle-stimulating hormone (FSH) and small testicular volume were significantly associated with lower chances of successful sperm retrieval. Some parameters, including testicular histopathology patterns, FSH levels, testicular volume, and method of TESE surgery, may be able to predict the chances of obtaining spermatozoa in patients with NOA. However, despite the efficiency of some predictive models, the hope of retrieving any functioning spermatozoa may be sufficient to disregard predictive factors of the success of intracytoplasmic sperm injection in these patients.

  7. TRECVID: the utility of a content-based video retrieval evaluation

    NASA Astrophysics Data System (ADS)

    Hauptmann, Alexander G.

    2006-01-01

    TRECVID, an annual retrieval evaluation benchmark organized by NIST, encourages research in information retrieval from digital video. TRECVID benchmarking covers both interactive and manual searching by end users, as well as the benchmarking of some supporting technologies including shot boundary detection, extraction of semantic features, and the automatic segmentation of TV news broadcasts. Evaluations done in the context of the TRECVID benchmarks show that generally, speech transcripts and annotations provide the single most important clue for successful retrieval. However, automatically finding the individual images is still a tremendous and unsolved challenge. The evaluations repeatedly found that none of the multimedia analysis and retrieval techniques provide a significant benefit over retrieval using only textual information such as from automatic speech recognition transcripts or closed captions. In interactive systems, we do find significant differences among the top systems, indicating that interfaces can make a huge difference for effective video/image search. For interactive tasks efficient interfaces require few key clicks, but display large numbers of images for visual inspection by the user. The text search finds the right context region in the video in general, but to select specific relevant images we need good interfaces to easily browse the storyboard pictures. In general, TRECVID has motivated the video retrieval community to be honest about what we don't know how to do well (sometimes through painful failures), and has focused us to work on the actual task of video retrieval, as opposed to flashy demos based on technological capabilities.

  8. Phase retrieval with the reverse projection method in the presence of object's scattering

    NASA Astrophysics Data System (ADS)

    Wang, Zhili; Gao, Kun; Wang, Dajiang

    2017-08-01

    X-ray grating interferometry can provide substantially increased contrast over traditional attenuation-based techniques in biomedical applications, and therefore novel and complementary information. Recently, special attention has been paid to quantitative phase retrieval in X-ray grating interferometry, which is mandatory to perform phase tomography, to achieve material identification, etc. An innovative approach, dubbed ;Reverse Projection; (RP), has been developed for quantitative phase retrieval. The RP method abandons grating scanning completely, and is thus advantageous in terms of higher efficiency and reduced radiation damage. Therefore, it is expected that this novel method would find its potential in preclinical and clinical implementations. Strictly speaking, the reverse projection method is applicable for objects exhibiting only absorption and refraction. In this contribution, we discuss the phase retrieval with the reverse projection method for general objects with absorption, refraction and scattering simultaneously. Especially, we investigate the influence of the object's scattering on the retrieved refraction signal. Both theoretical analysis and numerical experiments are performed. The results show that the retrieved refraction signal is the product of object's refraction and scattering signals for small values. In the case of a strong scattering, the reverse projection method cannot provide reliable phase retrieval. Those presented results will guide the use of the reverse projection method for future practical applications, and help to explain some possible artifacts in the retrieved images and/or reconstructed slices.

  9. 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.

  10. 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.

  11. GOSAT BESD XCO2 Retrieval: First Results

    NASA Astrophysics Data System (ADS)

    Heymann, Jens; Reuter, Maximilian; Hilker, Michael; Buchwitz, Michael; Schneising, Oliver; Bovensmann, Heinrich; Burrows, John P.

    2013-04-01

    Carbon dioxide (CO2) is the most important anthropogenic greenhouse gas contributing to global climate change. Column-averaged dry air mole fractions of CO2 (XCO2) as retrieved from near-surface sensitive measurements of satellite instruments such as SCIAMACHY onboard ENVISAT have the potential to provide important missing global information on the sources and sinks of CO2. This however requires to meet challenging accuracy requirements. In order to retrieve XCO2 from SCIAMACHY, the Bremen Optimal Estimation - DOAS (BESD) retrieval algorithm has been developed. After the end of the ENVISAT mission in March 2012, the only satellite instrument with high sensitivity near the surface is TANSO onboard GOSAT (launched 2009). To obtain a consistant global long-term XCO2 data set from these two instruments, a modified version of the BESD algorithm is also used for the retrieval of XCO2 from GOSAT. Here, first GOSAT BESD XCO2 retrieval results are presented.

  12. Retrieval practice protects memory against acute stress.

    PubMed

    Smith, Amy M; Floerke, Victoria A; Thomas, Ayanna K

    2016-11-25

    More than a decade of research has supported a robust consensus: Acute stress impairs memory retrieval. We aimed to determine whether a highly effective learning technique could strengthen memory against the negative effects of stress. To bolster memory, we used retrieval practice, or the act of taking practice tests. Participants first learned stimuli by either restudying or engaging in retrieval practice. Twenty-four hours later, we induced stress in half of the participants and assessed subsequent memory performance. Participants who learned by restudying demonstrated the typical stress-related memory impairment, whereas those who learned by retrieval practice were immune to the deleterious effects of stress. These results suggest that the effects of stress on memory retrieval may be contingent on the strength of the memory representations themselves. Copyright © 2016, American Association for the Advancement of Science.

  13. Retrievals of heavy ozone with MIPAS

    NASA Astrophysics Data System (ADS)

    Jonkheid, Bastiaan; Röckmann, Thomas; Glatthor, Norbert; Janssen, Christof; Stiller, Gabriele; von Clarmann, Thomas

    2016-12-01

    A method for retrieval of 18O-substituted isotopomers of O3 in the stratosphere with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) is presented. Using a smoothing regularisation constraint, volume mixing ratio profiles are retrieved for the main isotopologue and the symmetric and asymmetric isotopomers of singly substituted O3. For the retrieval of the heavy isotopologues, two microwindows in the MIPAS A band (685-970 cm-1) and six in the AB band (1020-1170 cm-1) are used. As the retrievals are performed as perturbations on the previously retrieved a priori profiles, the vertical resolution of the individual isotopomer profiles is very similar, which is important when calculating the ratio between two isotopomers. The performance of the method is evaluated using 1044 vertical profiles recorded with MIPAS on 1 July 2003. The mean values are separated by latitude bands, along with estimates of their uncertainties. The asymmetric isotopomer shows a mean enrichment of ˜ 8 %, with a vertical profile that increases up to 33 km and decreases at higher altitudes. This decrease with altitude is a robust result that does not depend on retrieval settings, and it has not been reported clearly in previously published datasets. The symmetric isotopomer is considerably less enriched, with mean values around 3 % and with a large spread. In individual retrievals the uncertainty of the enrichment is dominated by the measurement noise (2-4 %), which can be reduced by averaging multiple retrievals; systematic uncertainties linked to the retrieval are generally small at ˜ 0.5 %, but this is likely underestimated because the uncertainties in key spectroscopic parameters are unknown. The variabilities in the retrieval results are largest for the Southern Hemisphere.

  14. Brain CT image similarity retrieval method based on uncertain location graph.

    PubMed

    Pan, Haiwei; Li, Pengyuan; Li, Qing; Han, Qilong; Feng, Xiaoning; Gao, Linlin

    2014-03-01

    A number of brain computed tomography (CT) images stored in hospitals that contain valuable information should be shared to support computer-aided diagnosis systems. Finding the similar brain CT images from the brain CT image database can effectively help doctors diagnose based on the earlier cases. However, the similarity retrieval for brain CT images requires much higher accuracy than the general images. In this paper, a new model of uncertain location graph (ULG) is presented for brain CT image modeling and similarity retrieval. According to the characteristics of brain CT image, we propose a novel method to model brain CT image to ULG based on brain CT image texture. Then, a scheme for ULG similarity retrieval is introduced. Furthermore, an effective index structure is applied to reduce the searching time. Experimental results reveal that our method functions well on brain CT images similarity retrieval with higher accuracy and efficiency.

  15. Quantitative interferometric microscopy with two dimensional Hilbert transform based phase retrieval method

    NASA Astrophysics Data System (ADS)

    Wang, Shouyu; Yan, Keding; Xue, Liang

    2017-01-01

    In order to obtain high contrast images and detailed descriptions of label free samples, quantitative interferometric microscopy combining with phase retrieval is designed to obtain sample phase distributions from fringes. As accuracy and efficiency of recovered phases are affected by phase retrieval methods, thus approaches owning higher precision and faster processing speed are still in demand. Here, two dimensional Hilbert transform based phase retrieval method is adopted in cellular phase imaging, it not only reserves more sample specifics compared to classical fast Fourier transform based method, but also overcomes disadvantages of traditional algorithm according to Hilbert transform which is a one dimensional processing causing phase ambiguities. Both simulations and experiments are provided, proving the proposed phase retrieval approach can acquire quantitative sample phases with high accuracy and fast speed.

  16. 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.

  17. Toward an episodic context account of retrieval-based learning: dissociating retrieval practice and elaboration.

    PubMed

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

    2014-11-01

    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 press) assumes that retrieval alters the representation of episodic context and improves one's ability to guide memory search on future tests. Subjects studied multiple word lists and either recalled each list (retrieval practice), did a math task (control), or generated associates for each word (elaboration) after each list. After studying the last list, all subjects recalled the list and, after a 5-min delay, recalled all lists. Analyses of correct recall, intrusions, response times, and temporal clustering dissociate retrieval practice from elaboration, supporting the episodic context account. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  18. 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.

  19. Antigen Retrieval Causes Protein Unfolding

    PubMed Central

    Fowler, Carol B.; Evers, David L.; O’Leary, Timothy J.; Mason, Jeffrey T.

    2011-01-01

    Antigen retrieval (AR), in which formalin-fixed paraffin-embedded tissue sections are briefly heated in buffers at high temperature, often greatly improves immunohistochemical staining. An important unresolved question regarding AR is how formalin treatment affects the conformation of protein epitopes and how heating unmasks these epitopes for subsequent antibody binding. The objective of the current study was to use model proteins to determine the effect of formalin treatment on protein conformation and thermal stability in relation to the mechanism of AR. Sodium dodecyl sulfate polyacrylamide gel electrophoresis was used to identify the presence of protein formaldehyde cross-links, and circular dichroism spectropolarimetry was used to determine the effect of formalin treatment and high-temperature incubation on the secondary and tertiary structure of the model proteins. Results revealed that for some proteins, formalin treatment left the native protein conformation unaltered, whereas for others, formalin denatured tertiary structure, yielding a molten globule protein. In either case, heating to temperatures used in AR methods led to irreversible protein unfolding, which supports a linear epitope model of recovered protein immunoreactivity. Consequently, the core mechanism of AR likely centers on the restoration of normal protein chemical composition coupled with improved accessibility to linear epitopes through protein unfolding. PMID:21411808

  20. 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.

  1. Paraparesis in a Golden Retriever.

    PubMed

    Aschenbroich, S; Woolcock, A; Rissi, D R

    2014-09-01

    A 7-year-old female spayed Golden Retriever dog presented with fever and a 10-day history of neurological signs, including ambulatory paraparesis and pelvic limb ataxia. Neurological examination initially revealed a T3-L3 myelopathy. Thoracic radiographs revealed a diffuse miliary pulmonary pattern. Endotracheal washes and fine-needle aspirates from several organs aimed at identifying a potential infectious agent or neoplastic process were all unsuccessful. Due to worsening of the clinical signs, euthanasia was elected. Necropsy findings included multifocal, pale to dark red, firm nodules infiltrating the lungs, heart, mesentery, pancreas, small intestine, brain, and spinal cord. Cytological examination of impression smears obtained from the pulmonary nodules during necropsy revealed clusters of epithelioid cells admixed with fewer spindle cells, erythrocytes, and scattered leukocytes. Clinical signs and cytological findings initially suggested the possibility of a widespread granulomatous disease or a metastatic epithelial neoplasm as possible clinical differentials in this case. The final diagnosis was based on the gross and histological findings, with confirmation following histochemistry and immunohistochemistry. © The Author(s) 2013.

  2. 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.

  3. Data storage and retrieval system

    NASA Technical Reports Server (NTRS)

    Nakamoto, Glen

    1991-01-01

    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.

  4. 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

  5. Multilingual retrieval of radiology images.

    PubMed

    Kahn, Charles E

    2009-01-01

    The multilingual search engine ARRS GoldMiner Global was created to facilitate broad international access to a richly indexed collection of more than 200,000 radiologic images. Images are indexed according to key-words and medical concepts that appear in the unstructured text of their English-language image captions. GoldMiner Global exploits the Unicode standard, which allows the accurate representation of characters and ideographs from virtually any language and which supports both left-to-right and right-to-left text directions. The user interface supports queries in Arabic, Chinese, French, German, Italian, Japanese, Korean, Portuguese, Russian, or Spanish. GoldMiner Global incorporates an interface to the United States National Library of Medicine that translates queries into English-language Medical Subject Headings (MeSH) terms. The translated MeSH terms are then used to search the image index and retrieve relevant images. Explanatory text, pull-down menu choices, and navigational guides are displayed in the selected language; search results are displayed in English. GoldMiner Global is freely available on the World Wide Web.

  6. Treelets Binary Feature Retrieval for Fast Keypoint Recognition.

    PubMed

    Zhu, Jianke; Wu, Chenxia; Chen, Chun; Cai, Deng

    2015-10-01

    Fast keypoint recognition is essential to many vision tasks. In contrast to the classification-based approaches, we directly formulate the keypoint recognition as an image patch retrieval problem, which enjoys the merit of finding the matched keypoint and its pose simultaneously. To effectively extract the binary features from each patch surrounding the keypoint, we make use of treelets transform that can group the highly correlated data together and reduce the noise through the local analysis. Treelets is a multiresolution analysis tool, which provides an orthogonal basis to reflect the geometry of the noise-free data. To facilitate the real-world applications, we have proposed two novel approaches. One is the convolutional treelets that capture the image patch information locally and globally while reducing the computational cost. The other is the higher-order treelets that reflect the relationship between the rows and columns within image patch. An efficient sub-signature-based locality sensitive hashing scheme is employed for fast approximate nearest neighbor search in patch retrieval. Experimental evaluations on both synthetic data and the real-world Oxford dataset have shown that our proposed treelets binary feature retrieval methods outperform the state-of-the-art feature descriptors and classification-based approaches.

  7. 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.

  8. Retrieval of a separated instrument using Masserann technique

    PubMed Central

    Thirumalai, Arun Kulandaivelu; Sekar, Mahalaxmi; Mylswamy, Sumitha

    2008-01-01

    The fracture of endodontic instruments is a procedural problem creating a major obstacle to normal routine therapy. The separated instrument, particularly a broken file, leads to metallic obstruction in the root canal and impedes efficient cleaning and shaping. When an attempt to bypass such a fragment becomes difficult, it should be retrieved by mechanical devices. Masserann kit is one such device for orthograde removal of intracanal metallic obstructions. These clinical cases demonstrate the usage of Masserann technique in removal of separated instruments in anterior and also the posterior teeth. PMID:20142883

  9. 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.

  10. TDPP FOR THE RETRIEVABILITY STRATEGY REPORT

    SciTech Connect

    P.D. Gehner

    1997-01-28

    The objective of this systems study is to produce a waste removability strategy document that contains sufficient details, recommended design alternatives, and the technical rationale (a) to support Licensing in the development of the License Application Plan, and (b) to provide input in the form of design requirements, for the FY 97 Retrieval Design & Operation activity in support of viability assessment. The intent of this systems study is to support a decision on how to proceed with design with respect to retrievability, regarding the extent to which the repository/waste package designs should accommodate the retrieval option.

  11. Fuel Retrieval System Design Verification Report

    SciTech Connect

    GROTH, B.D.

    2000-04-11

    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). A Design Verification Status Questionnaire, Table 1, is included which addresses Corrective Action SNF-EG-MA-EG-20000060, Item No.9 (Miller 2000).

  12. Uncertainty characterization in the retrieval of an atmospheric point release

    NASA Astrophysics Data System (ADS)

    Singh, Sarvesh Kumar; Kumar, Pramod; Turbelin, Grégory; Rani, Raj

    2017-03-01

    The study proposes a methodology in a recent inversion technique, called as Renormalization, to characterize the uncertainties in the reconstruction of a point source. The estimates are derived for measuring the inversion error, the degree of model fit towards measurements (model determination coefficient) and the confidence intervals for the retrieved point source parameters (mainly, location and strength). The inversion error is reflected through an angular estimate which measures the deviation between the measured and predicted concentrations. The uncertainty estimation methodology is evaluated for point source reconstruction studies, using real measurements from two field experiments, known as Fusion Field Trials 2007 (FFT07) in flat terrain and Mock Urban Setting Test (MUST) in urban like terrain. In FFT07 and MUST experiments, the point source location is retrieved with an average Euclidean distance of 22 m and 15 m respectively. The source strength is retrieved, on average, within a factor of 1.5 in both the datasets. The inversion error is observed as 24o and 21o in FFT07 and MUST experiment, respectively. The 95% confidence interval estimates show that the uncertainty in the retrieved parameters is relatively large in approximately 50% FFT07 and 30% MUST trials in spite of their closeness towards true source parameters. For a comparative analysis, the interval estimates are also compared with a more general method of uncertainty estimation, Residual Bootstrap Sampling. In most of the trials, we observed that the intervals estimates with the present method are comparable (within 10-20% variations) to bootstrap estimates. The proposed methodology provides near accurate and computationally efficient uncertainty estimates in comparison to the methods based on Hessian and sampling procedures.

  13. Shape Retrieval Using Hierarchical Total Bregman Soft Clustering

    PubMed Central

    Liu, Meizhu; Vemuri, Baba C.; Amari, Shun-ichi; Nielsen, Frank

    2012-01-01

    In this paper, we consider the family of total Bregman divergences (tBDs) as an efficient and robust “distance” measure to quantify the dissimilarity between shapes. We use the tBD based ℓ1-norm center as the representative of a set of shapes, and call it the t-center. First, we briefly present and analyze the properties of the tBDs and t-centers following our previous work in [1]. Then, we prove that for any tBD, there exists a distribution which belongs to the lifted exponential family of statistical distributions. Further, we show that finding the maximum a posteriori estimate of the parameters of the lifted exponential family distribution is equivalent to minimizing the tBD to find the t-centers. This leads to a new clustering technique namely, the total Bregman soft clustering algorithm. We evaluate the tBD, t-center and the soft clustering algorithm on shape retrieval applications. Our shape retrieval framework is composed of three steps: (1) extraction of the shape boundary points (2) affine alignment of the shapes and use of a Gaussian mixture model (GMM) [2], [3], [4] to represent the aligned boundaries, and (3) comparison of the GMMs using tBD to find the best matches given a query shape. To further speed up the shape retrieval algorithm, we perform hierarchical clustering of the shapes using our total Bregman soft clustering algorithm. This enables us to compare the query with a small subset of shapes which are chosen to be the cluster t-centers. We evaluate our method on various public domain 2D and 3D databases, and demonstrate comparable or better results than state-of-the-art retrieval techniques. PMID:22331859

  14. Retrieval-induced forgetting: dynamic effects between retrieval and restudy trials when practice is mixed.

    PubMed

    Dobler, Ina M; Bäuml, Karl-Heinz T

    2013-05-01

    Results from numerous previous studies suggest that when subjects study items from different categories and then repeatedly retrieve, or restudy, some of the items from some of the categories, repeated retrieval, but not repeated study, induces forgetting of related unpracticed items. We investigated in two experiments whether such effects of pure retrieval and pure study practice generalize to mixed practice-that is, when retrieval and restudy trials are randomly interleaved within a single experimental block. Experiment 1 employed cued recall; Experiment 2 employed item recognition testing. In both experiments, pure repeated retrieval, but not pure repeated study, caused forgetting of related unpracticed items, which is consistent with the prior work. In contrast, with mixed practice, both retrieval and restudy induced forgetting. Thus, whereas retrieval caused forgetting regardless of practice mode, restudy caused forgetting with mixed practice, but not with pure practice. The finding provides first evidence for dynamic effects between retrieval and restudy trials when practice is mixed. It is consistent with the view that, with mixed practice, subjects engage in more retrieval during restudy trials, so that restudy trials may trigger similar processes as retrieval trials and, thus, induce forgetting of related, not restudied, items.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Geometrical misalignment retrieval of the IASI interferometer

    NASA Astrophysics Data System (ADS)

    Henault, Francois; Hebert, Philippe-Jean; Lucchini, Christophe; Miras, Didier

    1999-12-01

    The IASI instrument (Infrared Atmospheric Sounding Interferometer) is a Fourier-Transform Spectrometer (FTS) providing spectra of the Earth's atmosphere observed from space. The heart of the instrument is a Michelson interferometer (IHOS) equipped with two hollow cube-corners retro-reflectors in place of the classical flat mirrors. The main alignment requirements of the IASI interferometer are the lateral shift, or shear, of the moving cube-corner (seen through the beamsplitter) and the misalignment of its scanning axis: these contributions should not exceed 20 micrometer and 250 (mu) rad respectively during the five years mission in orbit. Thus the most difficult challenge of the IHOS integration on-ground probably is their measurement accuracy, which shall respectively be better than 1 micrometer and 100 (mu) rad. The envisaged characterization method consists in a specific data processing of the fringe patterns created by the interferometer at four different points located in the IHOS Field of View (FoV), corresponding to the IASI instrument pixels. For each acquired interferogram the Optical Path Difference (OPD) created by the interferometer are evaluated using a double Fourier-transform algorithm, and the results are combined together in order to retrieve the apparent trajectory of the mobile cube-corner. This principle was tested on a breadboard interferometer already assembled in the CNES laboratories. The numerical results presented herein tend to demonstrate the efficiency of the method, since the achieved accuracy does not exceed 1.2 micrometer (whatever the cube-corner axial position) and 120 (mu) rad respectively. The main error sources also are discussed.

  20. Information retrieval using a "digital book shelf".

    PubMed Central

    Frisse, M. E.; Cousins, S. B.; Hassan, S. W.

    1991-01-01

    WALT (Washington University's Approach to Lots of Text), is a prototype interface designed to support information retrieval research. The WALT interface serves as a "front end" to a wide array of retrieval engines including those based on Boolean retrieval, latent semantic indexing, term frequency--inverse document frequency, and Bayesian inference techniques. The WALT interface is composed of seven distinct components: a document examination component known as the Document Browsing Area; four navigation components called the Book Shelf, the Book Spine, the Table of Contents, and the Path Clipboard; a term-based information retrieval component called Control Panel; and a relevance feedback component known as the Reader Feedback Panel. WALT's most unique feature may be it's use of "book shelf" and "book spine" metaphors both to facilitate navigation and to provide a histogram-based display showing documents deemed appropriate for answering user queries. PMID:1807717

  1. 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)

  2. Computerized Information Storage and Retrieval Systems.

    ERIC Educational Resources Information Center

    Azubuike, Abraham A.; Umoh, Jackson S.

    1988-01-01

    Describes the concept of maximum indexing, a system aimed at achieving maximum recall and maximum precision in computerized information retrieval. The indexing strategies used to achieve maximum indexing and the problems that arise are discussed. (9 references) (CLB)

  3. The Indexing and Retrieval of Digital Items.

    ERIC Educational Resources Information Center

    Beaney, Sandie; Carpenter, Leona

    1996-01-01

    Discusses cataloging and indexing for the retrieval of digital items as part of the British Library's Initiatives for Access program. Highlights include standards, digital catalogs, Novel access software that includes fuzzy matching, software choice and development, and future possibilities. (LRW)

  4. 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)

  5. Content-Based Medical Image Retrieval

    NASA Astrophysics Data System (ADS)

    Müller, Henning; Deserno, Thomas M.

    This chapter details the necessity for alternative access concepts to the currently mainly text-based methods in medical information retrieval. This need is partly due to the large amount of visual data produced, the increasing variety of medical imaging data and changing user patterns. The stored visual data contain large amounts of unused information that, if well exploited, can help diagnosis, teaching and research. The chapter briefly reviews the history of image retrieval and its general methods before technologies that have been developed in the medical domain are focussed. We also discuss evaluation of medical content-based image retrieval (CBIR) systems and conclude with pointing out their strengths, gaps, and further developments. As examples, the MedGIFT project and the Image Retrieval in Medical Applications (IRMA) framework are presented.

  6. On Relative Indexing in Fuzzy Retrieval Systems.

    ERIC Educational Resources Information Center

    Rousseau, Ronald

    1985-01-01

    Presents a modification function for weights of descriptors for documents in fuzzy retrieval systems which includes some desirable properties that are lacking in the model proposed by Choros and Danilowicz in their study on relative indexing. (MBR)

  7. 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.

  8. Idiopathic Horner's syndrome in the golden retriever.

    PubMed

    Boydell, P

    1995-09-01

    A prospective study was made of cases of idiopathic Horner's syndrome in dogs referred to the author. Over a six-year period the condition was recorded in 62 golden retrievers. Examination suggested that the lesions affected the preganglionic neuron.

  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. Simplified Approach Charts Improve Data Retrieval Performance

    PubMed Central

    Stewart, Michael; Laraway, Sean; Jordan, Kevin; Feary, Michael S.

    2016-01-01

    The effectiveness of different instrument approach charts to deliver minimum visibility and altitude information during airport equipment outages was investigated. Eighteen pilots flew simulated instrument approaches in three conditions: (a) normal operations using a standard approach chart (standard-normal), (b) equipment outage conditions using a standard approach chart (standard-outage), and (c) equipment outage conditions using a prototype decluttered approach chart (prototype-outage). Errors and retrieval times in identifying minimum altitudes and visibilities were measured. The standard-outage condition produced significantly more errors and longer retrieval times versus the standard-normal condition. The prototype-outage condition had significantly fewer errors and shorter retrieval times than did the standard-outage condition. The prototype-outage condition produced significantly fewer errors but similar retrieval times when compared with the standard-normal condition. Thus, changing the presentation of minima may reduce risk and increase safety in instrument approaches, specifically with airport equipment outages. PMID:28491009

  11. Multi-Spectral Cloud Property Retrieval

    NASA Technical Reports Server (NTRS)

    Carlson, Barbara E.; Lynch, R

    1999-01-01

    Despite numerous studies to retrieve cloud properties using infrared measurements the information content of the data has not yet been fully exploited. In an effort to more fully utilize the information content of infrared measurements, we have developed a multi-spectral technique for retrieving effective cloud particle size, optical depth and effective cloud temperature. While applicable to all cloud types, we begin by validating our retrieval technique through analysis of MS spectral radiances obtained during the SUCCESS field campaign over the ARM SGP CART facility, and compare our retrieval product with lidar and MODIS Airborne Simulator (MAS) measurement results. The technique is then applied to the Nimbus-4 MS infrared spectral measurements to obtain global cloud information.

  12. Generalized tetanus in a Labrador retriever

    PubMed Central

    Sprott, Kerri-Rae

    2008-01-01

    A 10-week-old, intact female, Labrador retriever was presented for progressive extensor rigidity, facial swelling, and difficulty in walking. Generalized tetanus was diagnosed and treated successfully. PMID:19252716

  13. 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.

  14. 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

  15. 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

  16. Retrieval of ash properties from IASI measurements

    NASA Astrophysics Data System (ADS)

    Ventress, Lucy J.; McGarragh, Gregory; Carboni, Elisa; Smith, Andrew J.; Grainger, Roy G.

    2016-11-01

    A new optimal estimation algorithm for the retrieval of volcanic ash properties has been developed for use with the Infrared Atmospheric Sounding Interferometer (IASI). The retrieval method uses the wave number range 680-1200 cm-1, which contains window channels, the CO2 ν2 band (used for the height retrieval), and the O3 ν3 band.Assuming a single infinitely (geometrically) thin ash plume and combining this with the output from the radiative transfer model RTTOV, the retrieval algorithm produces the most probable values for the ash optical depth (AOD), particle effective radius, plume top height, and effective radiating temperature. A comprehensive uncertainty budget is obtained for each pixel. Improvements to the algorithm through the use of different measurement error covariance matrices are explored, comparing the results from a sensitivity study of the retrieval process using covariance matrices trained on either clear-sky or cloudy scenes. The result showed that, due to the smaller variance contained within it, the clear-sky covariance matrix is preferable. However, if the retrieval fails to pass the quality control tests, the cloudy covariance matrix is implemented.The retrieval algorithm is applied to scenes from the Eyjafjallajökull eruption in 2010, and the retrieved parameters are compared to ancillary data sources. The ash optical depth gives a root mean square error (RMSE) difference of 0.46 when compared to retrievals from the MODerate-resolution Imaging Spectroradiometer (MODIS) instrument for all pixels and an improved RMSE of 0.2 for low optical depths (AOD < 0.1). Measurements from the Facility for Airborne Atmospheric Measurements (FAAM) and Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR) flight campaigns are used to verify the retrieved particle effective radius, with the retrieved distribution of sizes for the scene showing excellent consistency. Further, the plume top altitudes are compared to derived cloud-top altitudes from the Cloud

  17. Retrieval of ice cloud properties with visible/near-/shortwave-infrared (VNIR/SWIR) and thermal-infrared (TIR) obaservations

    NASA Astrophysics Data System (ADS)

    Wang, C.; Platnick, S. E.; Meyer, K.; Zhang, Z.; Yang, P.; Ding, J.

    2016-12-01

    An optical-estimation (OE) based ice cloud retrieval algorithm is developed with visible/near-/shortwave-infrared (VNIR/SWIR) and thermal-infrared (TIR) observations. It is known that VNIR/SWIR observations are more sensitive to optically thick clouds, while TIR observations are more sensitive to optically thin clouds. The combination of both VNIR/SWIR and TIR observations is expected to improve the overall ice cloud retrieval performance. In this study, we develop an optimal method to select different bands for retrieving different types of ice clouds (e.g., thin cirrus or deep convective cloud). With the optimally selected bands, retrieval uncertainties are minimized and information content are maximized. The retrieval algorithm is based on a clear-sky transmittance module and a radiative transfer model that cover the VNIR/SWIR and TIR regions. The forward model is computational efficiency and therefore can be used to a wide variaty of remote sensing applications.

  18. 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.

  19. 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

  20. 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.