636 research outputs found

    Automatic domain ontology extraction for context-sensitive opinion mining

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    Automated analysis of the sentiments presented in online consumer feedbacks can facilitate both organizations’ business strategy development and individual consumers’ comparison shopping. Nevertheless, existing opinion mining methods either adopt a context-free sentiment classification approach or rely on a large number of manually annotated training examples to perform context sensitive sentiment classification. Guided by the design science research methodology, we illustrate the design, development, and evaluation of a novel fuzzy domain ontology based contextsensitive opinion mining system. Our novel ontology extraction mechanism underpinned by a variant of Kullback-Leibler divergence can automatically acquire contextual sentiment knowledge across various product domains to improve the sentiment analysis processes. Evaluated based on a benchmark dataset and real consumer reviews collected from Amazon.com, our system shows remarkable performance improvement over the context-free baseline

    Information Granulation for the Design of Granular Information Retrieval Systems

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    With the explosive growth of the amount of information stored on computer networks such as the Internet, it is increasingly more difficult for information seekers to retrieve relevant information. Traditional document ranking functions employed by Internet search engines can be enhanced to improve the effectiveness of information retrieval (IR). This paper illustrates the design and development of a granular IR system to facilitate domain specific search. In particular, a novel computational model is designed to rank documents according the searchers’ specific granularity requirements. The initial experiments confirm that our granular IR system outperforms a classical vector-based IR system. In addition, user-based evaluations also demonstrate that our granular IR system is effective when compared with a well-known Internet search engine. Our research work opens the door to the design and development of the next generation of Internet search engines to alleviate the problem of information overload

    Photo-induced reduction of graphene oxide coating on optical waveguide and consequent optical intermodulation

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    Increased absorption of transverse-magnetic (TM) - polarised light by a graphene-oxide (GO) coated polymer waveguide has been observed in the presence of transverse-electric (TE) - polarised light. The GO-coated waveguide exhibits very strong photo-absorption of TE-polarised light - and acts as a TM-pass waveguide polariser. The absorbed TE-polarised light causes a significant temperature increase in the GO film and induces thermal reduction of the GO, resulting in an increase in optical-frequency conductivity and consequently increased optical propagation loss. This behaviour in a GO-coated waveguide gives the action of an inverted optical switch/modulator. By varying the incident TE-polarised light power, a maximum modulation efficiency of 72% was measured, with application of an incident optical power level of 57 mW. The GO-coated waveguide was able to respond clearly to modulated TE-polarised light with a pulse duration of as little as 100 μs. In addition, no wavelength dependence was observed in the response of either the modulation (TE-polarised light) or the signal (TM-polarised light)

    Circulating human leucine-rich a-2-glycoprotein 1 mRNA and protein levels to detect acute appendicitis in patients with acute abdominal pain

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    Background Elevated levels of circulating plasma and urine leucine-rich-2-glycoprotein-1 (LRG1) protein has been found in patients with acute appendicitis (AA) and may be useful for diagnosis. This study aimed to investigate whether combined tests including circulating LRG1 mRNA levels improve the early diagnosis of AA. Methods Between December 2011 and October 2012, a prospective study was conducted on patients aged 18 years or older presenting to the ED with acute abdominal pain (< 7 days of symptom onset). Levels of whole blood LRG1 mRNA and plasma LRG1 protein taken from these patients within 24 h of arrival (mean 12.4 h) were analyzed. The primary outcome was AA. Results Eighty-four patients (40 (47.6%) with AA and 44 (52.4%) without AA; mean age 35 years; 41.6% males) were recruited. Median whole blood LRG1 mRNA and plasma LRG1 levels were higher in AA patients than in non-AA. Of 40 AA patients, 13 (32.5%) were diagnosed as complicated AA. In ROC analysis of LRG1 mRNA (normalized to GAPDH), LRG1 protein and Alvarado score for discriminating AA and non-AA, the areas under the curve (AUC) were 0.723, 0.742 and 0.805 respectively. The AUC of combination of normalized LRG1 mRNA, LRG1 protein and Alvarado score was 0.845. Conclusion A combination of modified whole blood LRG1 mRNA levels, plasma LRG1 protein and Alvarado score at the ED may be useful to diagnose simple and complicated AA from other causes of abdominal pain

    Pion and Kaon Production in e+e−e^+e^- and epep Collisions at Next-to-Leading Order

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    We present new sets of fragmentation functions for charged pions and kaons, both at leading and next-to-leading order. They are fitted to data on inclusive charged-hadron production in e+e−e^+e^- annihilation taken by TPC at PEP (s=29\sqrt s=29~GeV) and to similar data by ALEPH at LEP, who discriminated between events with charm, bottom, and light- flavour fragmentation in their charged-hadron sample. We treat all partons independently and to properly incorporate the charm and bottom thresholds. Due to the sizeable energy gap between PEP and LEP, we are sensitive to the scaling violation in the fragmentation process, which allows us to extract a value for the asymptotic scale parameter of QCD, Λ\Lambda. Recent data on inclusive charged-hadron production in tagged three-jet events by OPAL and similar data for longitudinal electron polarization by ALEPH allow us to pin down the gluon fragmentation functions. Our new fragmentation functions lead to an excellent description of a multitude of other e+e−e^+e^- data on inclusive charged-hadron production, ranging from s=5.2\sqrt s=5.2~GeV to LEP energy. In addition, they agree nicely with the transverse-momentum spectra of single charged hadrons measured by H1 and ZEUS in photoproduction at the epep collider HERA, which represents a nontrivial check of the factorization theorem of the QCD-improved parton model.Comment: 22 pages, latex, 13 compressed ps figures in separate fil

    Approximate k-state solutions to the Dirac-Yukawa problem based on the spin and pseudospin symmetry

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    Using an approximation scheme to deal with the centrifugal (pseudo-centrifugal) term, we solve the Dirac equation with the screened Coulomb (Yukawa) potential for any arbitrary spin-orbit quantum number {\kappa}. Based on the spin and pseudospin symmetry, analytic bound state energy spectrum formulas and their corresponding upper- and lower-spinor components of two Dirac particles are obtained using a shortcut of the Nikiforov-Uvarov method. We find a wide range of permissible values for the spin symmetry constant C_{s} from the valence energy spectrum of particle and also for pseudospin symmetry constant C_{ps} from the hole energy spectrum of antiparticle. Further, we show that the present potential interaction becomes less (more) attractive for a long (short) range screening parameter {\alpha}. To remove the degeneracies in energy levels we consider the spin and pseudospin solution of Dirac equation for Yukawa potential plus a centrifugal-like term. A few special cases such as the exact spin (pseudospin) symmetry Dirac-Yukawa, the Yukawa plus centrifugal-like potentials, the limit when {\alpha} becomes zero (Coulomb potential field) and the non-relativistic limit of our solution are studied. The nonrelativistic solutions are compared with those obtained by other methods.Comment: 21 pages, 6 figure

    Partial Wave Analysis of J/ψ→γ(K+K−π+π−)J/\psi \to \gamma (K^+K^-\pi^+\pi^-)

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    BES data on J/ψ→γ(K+K−π+π−)J/\psi \to \gamma (K^+K^-\pi^+\pi^-) are presented. The K∗Kˉ∗K^*\bar K^* contribution peaks strongly near threshold. It is fitted with a broad 0−+0^{-+} resonance with mass M=1800±100M = 1800 \pm 100 MeV, width Γ=500±200\Gamma = 500 \pm 200 MeV. A broad 2++2^{++} resonance peaking at 2020 MeV is also required with width ∼500\sim 500 MeV. There is further evidence for a 2−+2^{-+} component peaking at 2.55 GeV. The non-K∗Kˉ∗K^*\bar K^* contribution is close to phase space; it peaks at 2.6 GeV and is very different from K∗K∗ˉK^{*}\bar{K^{*}}.Comment: 15 pages, 6 figures, 1 table, Submitted to PL

    Measurements of the observed cross sections for e+e−→e^+e^-\to exclusive light hadrons containing π0π0\pi^0\pi^0 at s=3.773\sqrt s= 3.773, 3.650 and 3.6648 GeV

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    By analyzing the data sets of 17.3, 6.5 and 1.0 pb−1^{-1} taken, respectively, at s=3.773\sqrt s= 3.773, 3.650 and 3.6648 GeV with the BES-II detector at the BEPC collider, we measure the observed cross sections for e+e−→π+π−π0π0e^+e^-\to \pi^+\pi^-\pi^0\pi^0, K+K−π0π0K^+K^-\pi^0\pi^0, 2(π+π−π0)2(\pi^+\pi^-\pi^0), K+K−π+π−π0π0K^+K^-\pi^+\pi^-\pi^0\pi^0 and 3(π+π−)π0π03(\pi^+\pi^-)\pi^0\pi^0 at the three energy points. Based on these cross sections we set the upper limits on the observed cross sections and the branching fractions for ψ(3770)\psi(3770) decay into these final states at 90% C.L..Comment: 7 pages, 2 figure
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