962 research outputs found

    K Means Segmentation of Alzheimers Disease in PET scan datasets: An implementation

    Full text link
    The Positron Emission Tomography (PET) scan image requires expertise in the segmentation where clustering algorithm plays an important role in the automation process. The algorithm optimization is concluded based on the performance, quality and number of clusters extracted. This paper is proposed to study the commonly used K Means clustering algorithm and to discuss a brief list of toolboxes for reproducing and extending works presented in medical image analysis. This work is compiled using AForge .NET framework in windows environment and MATrix LABoratory (MATLAB 7.0.1)Comment: International Joint Conference on Advances in Signal Processing and Information Technology, SPIT201

    Observations of temporal group delays in slow-light multiple coupled photonic crystal cavities

    Get PDF
    We demonstrate temporal group delays in coherently-coupled high-Q multi-cavity photonic crystals, in an all-optical analogue to electromagnetically induced transparency. We report deterministic control of the group delay up to 4× the single cavity lifetime in our CMOS-fabricated room-temperature chip. Supported by three-dimensional numerical simulations and theoretical analyses, our multi-pump beam approach enables control of the multi-cavity resonances and inter-cavity phase, in both single and double transparency peaks. The standing-wave wavelength-scale photon localization allows direct scalability for chip-scale optical pulse trapping and coupled-cavity QED

    Efficient Red Organic Light Emitting Diodes of Nona Coordinate Europium Tris(β-diketonato) Complexes Bearing 4'-Phenyl-2,2':6',2''- terpyridine

    Get PDF
    Two novel nona-coordinated Eu(III) complexes [Eu(btfa) 3(Ph-TerPyr)] (Eu-1) and [Eu(NTA) 3(Ph-TerPyr)] (Eu-2) have been synthesized and characterized. The structure of the complexes was elucidated by density functional theory (DFT) methods. The experimental photophysical properties of the complexes were investigated and complemented with theoretical calculations. Effective energy transfer (ET) pathways for the sensitized red luminescence is discussed. The complexes were tested as emitting layers (EML) in organic light emitting diodes (OLEDs). At the optimum doping concentration of 4 wt.%, the double-EML OLEDs of Eu-1 exhibited red electroluminescence (EL) with an EQE of 4.0 % and maximum brightness (B)=1179 cd/m 2, maximum current efficiency (η c)=5.64 cd/A, and maximum power efficiency (η p)=4.78 lm/W at the current density (J) of 10 mA/cm 2. Interestingly, the double-EML OLEDs of Eu-2 at the optimum concentration of 3 wt.%, displayed an outstanding EL performance with EQE of 7.32 % and B=838 cd/m 2, η c=10.19 cd/A and η p=10.33 lm/W at J=10 mA/cm 2. The EL performance of this device is among the best reported for devices incorporating a europium complex as a red emitter.</p

    Efficient Red Organic Light Emitting Diodes of Nona Coordinate Europium Tris(β-diketonato) Complexes Bearing 4'-Phenyl-2,2':6',2''- terpyridine

    Get PDF
    Two novel nona-coordinated Eu(III) complexes [Eu(btfa) 3(Ph-TerPyr)] (Eu-1) and [Eu(NTA) 3(Ph-TerPyr)] (Eu-2) have been synthesized and characterized. The structure of the complexes was elucidated by density functional theory (DFT) methods. The experimental photophysical properties of the complexes were investigated and complemented with theoretical calculations. Effective energy transfer (ET) pathways for the sensitized red luminescence is discussed. The complexes were tested as emitting layers (EML) in organic light emitting diodes (OLEDs). At the optimum doping concentration of 4 wt.%, the double-EML OLEDs of Eu-1 exhibited red electroluminescence (EL) with an EQE of 4.0 % and maximum brightness (B)=1179 cd/m 2, maximum current efficiency (η c)=5.64 cd/A, and maximum power efficiency (η p)=4.78 lm/W at the current density (J) of 10 mA/cm 2. Interestingly, the double-EML OLEDs of Eu-2 at the optimum concentration of 3 wt.%, displayed an outstanding EL performance with EQE of 7.32 % and B=838 cd/m 2, η c=10.19 cd/A and η p=10.33 lm/W at J=10 mA/cm 2. The EL performance of this device is among the best reported for devices incorporating a europium complex as a red emitter.</p

    A Tris β-Diketonate Europium(III) Complex Based OLED Fabricated by Thermal Evaporation Method Displaying Efficient Bright Red Emission

    Get PDF
    202209 bcwwNot applicableRGCOthersHis Majesty’s Trust Fund for Strategic Research; Brazilian funding agencies: CAPES, CNPq,FACEPE and FAPITEC/SE; Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials; Hong Kong Polytechnic University; Endowed Professorship in Energy from Ms Clarea Au; NSFC; outh Innovation Promotion Association of Chinese Academy of Sciences; Engineering and Physical Sciences Research Council (EPSRC)Published24 month

    The Muonium Atom as a Probe of Physics beyond the Standard Model

    Get PDF
    The observed interactions between particles are not fully explained in the successful theoretical description of the standard model to date. Due to the close confinement of the bound state muonium (M=μ+eM = \mu^+ e^-) can be used as an ideal probe of quantum electrodynamics and weak interaction and also for a search for additional interactions between leptons. Of special interest is the lepton number violating process of sponteanous conversion of muonium to antimuonium.Comment: 15 pages,6 figure

    Synthesis and Photophysical Properties of Ternary β-Diketonate Europium(III) Complexes Incorporating Bipyridine and its Derivatives

    Get PDF
    Two new octa-coordinated ternary europium(III) complexes of the type [Eu(btfa)3(Br2-bpy)] (Eu-1) and [Eu(btfa)3(PhE2-bpy)] (Eu-2) (where btfa = 4,4,4-trifluoro-1-phenyl-1,3-butanedione, Br2-bpy = 5,5'-dibromo-2,2'-bipyridine, PhE2-bpy 5,5'-bis(phenylethynyl)-2,2'-bipyridine) together with a previously reported complex [Eu(btfa)3(bpy)] (Eu-3) have been synthesized. The complexes have been characterized by analytical and spectroscopic methods. The photophysical properties of the complexes have also been analyzed both experimentally and theoretically. The contribution of each ligand to the sensitized Eu(III) photoluminescence (PL) has been analyzed and is discussed. An energy transfer (ET) mechanism is proposed and discussed for the sensitized Eu(III) emission using experimental and theoretical data. The Eu(III) complex incorporating the parent bpy showed impressive performance as a double-emitting layer (EML) red organic light emitting diodes (R-OLEDs)

    Entanglement, Mixedness, and Spin-Flip Symmetry in Multiple-Qubit Systems

    Full text link
    A relationship between a recently introduced multipartite entanglement measure, state mixedness, and spin-flip symmetry is established for any finite number of qubits. It is also shown that, within those classes of states invariant under the spin-flip transformation, there is a complementarity relation between multipartite entanglement and mixedness. A number of example classes of multiple-qubit systems are studied in light of this relationship.Comment: To appear in Physical Review A; submitted 14 May 200
    corecore