3,131 research outputs found

    ACH: Away Cluster Heads Scheme for Energy Efficient Clustering Protocols in WSNs

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    This paper deals with the routing protocols for distributed wireless sensor networks. The conventional protocols for WSNs like Low Energy adaptive Clustering Hierarchy (LEACH), Stable Election Protocol (SEP), Threshold Sensitive Energy Efficient Network (TEEN), Distributed Energy Efficient Clustering Protocol (DEEC) may not be optimal. We propose a scheme called Away Cluster Head (ACH) which effectively increases the efficiency of conventional clustering based protocols in terms of stability period and number of packets sent to base station (BS). We have implemented ACH scheme on LEACH, SEP, TEEN and DEEC. Simulation results show that LEACHACH, SEP-ACH, TEEN-ACH and DEEC-ACH performs better than LEACH, SEP, TEEN and DEEC respectively in terms of stability period and number of packets sent to BS. The stability period of the existing protocols prolongs by implementing ACH on them.Comment: 2nd IEEE Saudi International Electronics, Communications and Photonics Conference (SIECPC 13), 2013, Riyadh, Saudi Arabi

    Superior performance of engineered mannitol as a carrier in dry powder inhalations containing salbutamol sulphate

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    The use of freeze drying technique can constitute an important step used in the pharmaceutical industry towards preparing freeze dried carrier particles which could help to solve some problems connected to drug-carrier dry powder aerosol formulations

    Using TF-IDF n-gram and word embedding cluster ensembles for author profiling: Notebook for PAN at CLEF 2017

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    This paper presents our approach and results for the 2017 PAN Author Profiling Shared Task. Language-specific corpora were provided for four langauges: Spanish, English, Portuguese, and Arabic. Each corpus consisted of tweets authored by a number of Twitter users labeled with their gender and the specific variant of their language which was used in the documents (e.g. Brazilian or European Portuguese). The task was to develop a system to infer the same attributes for unseen Twitter users. Our system employs an ensemble of two probabilistic classifiers: a Logistic regression classifier trained on TF-IDF transformed n-grams and a Gaussian Process classifier trained on word embedding clusters derived for an additional, external corpus of tweets

    Magnetic resonance imaging findings in patients with schizophrenia

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    OBJECTIVE: To determine structural abnormalities in the brain of patients with schizophrenia by Magnetic Resonance Imaging (MRI). STUDY DESIGN: Comparative study. PLACE AND DURATION OF STUDY: The Departments of Radiology and Psychiatry, the Aga Khan University Hospital, Karachi, from January 2007 to June 2008. METHODOLOGY: Thirty-three cases of schizophrenia (n=33) and thirty-three age-matched controls, (n=33) were enrolled for this study. Screening Magnetic Resonance Imaging (MRI) of brain was done in order to see structural changes in brain matter. Findings were compared among groups using chi-square and Fisher\u27s exact test with significance at p \u3c 0.05. RESULTS: Among the total of 66 (n=66) MRI films studied for brain abnormalities, brain atrophy, presence of septum pellucidum and enlarged Virchow-Robins spaces were significantly associated with schizophrenia (p \u3c 0.001). There was no significant difference between cases and controls for ventricular dilatation (p=0.5). Sinusitis was mostly associated with controls and well correlated with their symptoms (p \u3c 0.001). CONCLUSION: Brain atrophy was the most commonly seen brain change in the studied sample of patients with schizophrenia. MRI brain can be used to identify structural abnormalities in patients with schizophrenia

    Preconditioning Maximal Center Gauge with Stout Link Smearing in SU(3)

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    Center vortices are studied in SU(3) gauge theory using Maximal Center Gauge (MCG) fixing. Stout link smearing and over-improved stout link smearing are used to construct a preconditioning gauge field transformation, applied to the original gauge field before fixing to MCG. We find that preconditioning successfully achieves higher gauge fixing maxima. We observe a reduction in the number of identified vortices when preconditioning is used, and also a reduction in the vortex-only string tension.Comment: 9 pages, 4 figure

    Quantum gas microscopy of an attractive Fermi-Hubbard system

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    The attractive Fermi-Hubbard model is the simplest theoretical model for studying pairing and superconductivity of fermions on a lattice. Although its s-wave pairing symmetry excludes it as a microscopic model for high-temperature superconductivity, it exhibits much of the relevant phenomenology, including a short-coherence length at intermediate coupling and a pseudogap regime with anomalous properties. Here we study an experimental realization of this model using a two-dimensional (2D) atomic Fermi gas in an optical lattice. Our site-resolved measurements on the normal state reveal checkerboard charge-density-wave correlations close to half-filling. A "hidden" SU(2) pseudo-spin symmetry of the Hubbard model at half-filling guarantees superfluid correlations in our system, the first evidence for such correlations in a single-band Hubbard system of ultracold fermions. Compared to the paired atom fraction, we find the charge-density-wave correlations to be a much more sensitive thermometer, useful for optimizing cooling into superfluid phases in future experiments
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