3,954 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

    Improved Approximation Algorithms for Computing k Disjoint Paths Subject to Two Constraints

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    For a given graph GG with positive integral cost and delay on edges, distinct vertices ss and tt, cost bound CZ+C\in Z^{+} and delay bound DZ+D\in Z^{+}, the kk bi-constraint path (kkBCP) problem is to compute kk disjoint stst-paths subject to CC and DD. This problem is known NP-hard, even when k=1k=1 \cite{garey1979computers}. This paper first gives a simple approximation algorithm with factor-(2,2)(2,2), i.e. the algorithm computes a solution with delay and cost bounded by 2D2*D and 2C2*C respectively. Later, a novel improved approximation algorithm with ratio (1+β,max{2,1+ln1β})(1+\beta,\,\max\{2,\,1+\ln\frac{1}{\beta}\}) is developed by constructing interesting auxiliary graphs and employing the cycle cancellation method. As a consequence, we can obtain a factor-(1.369,2)(1.369,\,2) approximation algorithm by setting 1+ln1β=21+\ln\frac{1}{\beta}=2 and a factor-(1.567,1.567)(1.567,\,1.567) algorithm by setting 1+β=1+ln1β1+\beta=1+\ln\frac{1}{\beta}. Besides, by setting β=0\beta=0, an approximation algorithm with ratio (1,O(lnn))(1,\, O(\ln n)), i.e. an algorithm with only a single factor ratio O(lnn)O(\ln n) on cost, can be immediately obtained. To the best of our knowledge, this is the first non-trivial approximation algorithm for the kkBCP problem that strictly obeys the delay constraint.Comment: 12 page

    CMB Power Spectrum from Noncommutative Spacetime

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    Very recent CMB data of WMAP offers an opportunity to test inflation models, in particular, the running of spectral index is quite new and can be used to rule out some models. We show that an noncommutative spacetime inflation model gives a good explanation of these new results. In fitting the data, we also obtain a relationship between the noncommutative parameter (string scale) and the ending time of inflation.Comment: 8 pages, 2 figures; v2: refs. added and minor corrections; v3: further minor correctio

    An Operational Statistical Scheme for Tropical Cyclone-Induced Rainfall Forecast

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    Nonparametric methods are used in this study to analyze and predict short-term rainfall due to tropical cyclones (TCs) in a coastal meteorological station. All 427 TCs during 1953–2011, which made landfall along the Southeast China coast with a distance less than 700 km to a certain meteorological station, Shenzhen, are analyzed and grouped according to their landfalling direction, distance, and intensity. The corresponding daily rainfall records at Shenzhen Meteorological Station (SMS) during TCs landfalling period (a couple of days before and after TC landfall) are collected. The maximum daily rainfall (R24) and maximum 3-day accumulative rainfall (R72) records at SMS for each TC category are analyzed by a nonparametric statistical method, percentile estimation. The results are plotted by statistical boxplot, expressing in the probability of precipitation. The performance of the statistical boxplots was evaluated to forecast the short-term rainfall at SMS during the TC seasons in 2012 and 2013. The results show that the boxplot scheme can be used as a valuable reference to predict the short-term rainfall at SMS due to TCs landfalling along the Southeast China coast

    Effects of Applied Loads, Effective Contact Area and Surface Roughness on the Dicing Yield of 3D Cu Bonded Interconnects

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    Bonded copper interconnects were created using thermo-compression bonding and the dicing yield was used as an indication of the bond quality. SEM images indicated that the Cu was plastically deformed. Our experimental and modeling results indicate that the effective contact area is directly proportional to the applied load. Furthermore, for first time, results have been obtained that indicate that the dicing yield is proportional to the measured bond strength, and the bond strength is proportional to the effective contact area. It is also shown that films with rougher surfaces (and corresponding lower effective bonding areas) have lower bond strengths and dicing yields. A quantitative model for the relationship between measured surface roughness and the corresponding dicing yield has been developed. An appropriate surface-roughness data acquisition methodology has also been developed. The maximum possible applied load and the minimum possible surface roughness are required to obtain the maximum effective contact area, and hence to achieve optimum yields (both mechanically and electrically).Singapore-MIT Alliance (SMA

    Exact solution of the An1(1)A^{(1)}_{n-1} trigonometric vertex model with non-diagonal open boundaries

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    The An1(1)A^{(1)}_{n-1} trigonometric vertex model with {\it generic non-diagonal} boundaries is studied. The double-row transfer matrix of the model is diagonalized by algebraic Bethe ansatz method in terms of the intertwiner and the corresponding face-vertex relation. The eigenvalues and the corresponding Bethe ansatz equations are obtained.Comment: Latex file, 25 pages; V2: minor typos corrected, the version appears in JHE

    Hamiltonian Formalism of the de-Sitter Invariant Special Relativity

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    Lagrangian of the Einstein's special relativity with universal parameter cc (SRc\mathcal{SR}_c) is invariant under Poincar\'e transformation which preserves Lorentz metric ημν\eta_{\mu\nu}. The SRc\mathcal{SR}_c has been extended to be one which is invariant under de Sitter transformation that preserves so called Beltrami metric BμνB_{\mu\nu}. There are two universal parameters cc and RR in this Special Relativity (denote it as SRcR\mathcal{SR}_{cR}). The Lagrangian-Hamiltonian formulism of SRcR\mathcal{SR}_{cR} is formulated in this paper. The canonic energy, canonic momenta, and 10 Noether charges corresponding to the space-time's de Sitter symmetry are derived. The canonical quantization of the mechanics for SRcR\mathcal{SR}_{cR}-free particle is performed. The physics related to it is discussed.Comment: 24 pages, no figur

    Lamellar Phase of Stacked Two-Dimensional Rafts of Actin Filaments

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    We examined liquid crystalline phases of the cytoskeletal polyelectrolyte filamentous (F-)actin in the presence of multivalent counterions. As a function of increasing ion concentration, the F-actin rods in either an isotropic or a nematic phase will transform into a new and unexpected lamellar phase of crosslinked rafts (LXR phase), before condensing into a bundled phase of parallel, close-packed rods. This behavior is generic for alkali earth divalent ions Mg2+, Ca2+, Sr2+, and Ba2+, and the structural transitions are achieved without any architecture-specific actin-binding linker proteins

    Curved Flats, Pluriharmonic Maps and Constant Curvature Immersions into Pseudo-Riemannian Space Forms

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    We study two aspects of the loop group formulation for isometric immersions with flat normal bundle of space forms. The first aspect is to examine the loop group maps along different ranges of the loop parameter. This leads to various equivalences between global isometric immersion problems among different space forms and pseudo-Riemannian space forms. As a corollary, we obtain a non-immersibility theorem for spheres into certain pseudo-Riemannian spheres and hyperbolic spaces. The second aspect pursued is to clarify the relationship between the loop group formulation of isometric immersions of space forms and that of pluriharmonic maps into symmetric spaces. We show that the objects in the first class are, in the real analytic case, extended pluriharmonic maps into certain symmetric spaces which satisfy an extra reality condition along a totally real submanifold. We show how to construct such pluriharmonic maps for general symmetric spaces from curved flats, using a generalised DPW method.Comment: 21 Pages, reference adde
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