257 research outputs found

    On Power Allocation for Distributed Detection with Correlated Observations and Linear Fusion

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    We consider a binary hypothesis testing problem in an inhomogeneous wireless sensor network, where a fusion center (FC) makes a global decision on the underlying hypothesis. We assume sensors observations are correlated Gaussian and sensors are unaware of this correlation when making decisions. Sensors send their modulated decisions over fading channels, subject to individual and/or total transmit power constraints. For parallel-access channel (PAC) and multiple-access channel (MAC) models, we derive modified deflection coefficient (MDC) of the test statistic at the FC with coherent reception.We propose a transmit power allocation scheme, which maximizes MDC of the test statistic, under three different sets of transmit power constraints: total power constraint, individual and total power constraints, individual power constraints only. When analytical solutions to our constrained optimization problems are elusive, we discuss how these problems can be converted to convex ones. We study how correlation among sensors observations, reliability of local decisions, communication channel model and channel qualities and transmit power constraints affect the reliability of the global decision and power allocation of inhomogeneous sensors

    Tweet2Vec: Learning Tweet Embeddings Using Character-level CNN-LSTM Encoder-Decoder

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    We present Tweet2Vec, a novel method for generating general-purpose vector representation of tweets. The model learns tweet embeddings using character-level CNN-LSTM encoder-decoder. We trained our model on 3 million, randomly selected English-language tweets. The model was evaluated using two methods: tweet semantic similarity and tweet sentiment categorization, outperforming the previous state-of-the-art in both tasks. The evaluations demonstrate the power of the tweet embeddings generated by our model for various tweet categorization tasks. The vector representations generated by our model are generic, and hence can be applied to a variety of tasks. Though the model presented in this paper is trained on English-language tweets, the method presented can be used to learn tweet embeddings for different languages.Comment: SIGIR 2016, July 17-21, 2016, Pisa. Proceedings of SIGIR 2016. Pisa, Italy (2016

    Reproduction and maturity of false trevally (Lactarius lactarius) in coastal waters of the Oman Sea

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    In order to determine the reproduction period, the peak time of spawning, length of maturity and mesh standard size for False Trevally (Lactarius lactarius), we conducted a study from November 2007 to October 2008 in coastal waters of the Oman Sea. A total of 702 False Trevally specimens were collected randomly from the catch composition of gillnets and Ferdows-3 stem trawler. Mean total length and total weight were estimated at 22.7 plus or minus 2.13cm and 142.2 plus or minus 41.64g for females and 20.4c 1.89cm and 103.14c 29.07g for males respectively. Male to female sex ratio was 0.37:1 and females were more abundant than males in all months except June and August. Males had smaller sizes than females and the females outnumbered the mails up to the total length 25.5cm. The maximum of GS delta was estimated at 3.69 for females in June and 0.89 for males in July. The trend of GS delta and the frequency of maturity stages showed that reproduction period was from February to September with a spawning peak in August. Absolute fecundity was calculated at 102032 ova and relative fecundity was estimated at 4491.9 ova and 780.7 ova to total length and total weight respectively. Lm sub(50%) (length of maturity) and standard mesh size was calculated at 24.4cm and 3.9cm, respectively

    Gene 18s rRNA variation of cuttlefish population (Sepia pharaonis) in the Persian Gulf and the Oman Sea using PCR-RFLP method

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    We used PCR-RFLP method to identify cuttlefish (Sepia pharaonis) populations in the Persian Gulf and the Sea of Oman. Bottom trawling method was used to collect a range of 20 to 40 specimens from each 15 stations in the study area. Genomic DNA was extracted by phenol-chloroform method and one pair primer was designed for the analysis based on 1 Ss rRNA gene nucleotide sequences. A PCR product with 502 pair bases in length was obtained for all specimens and subjected to digestion by eight restriction enzymes Alui, Tacit, MO, Rsal, Hinalli, Dral, Prull and Mien DNA banding, patterns in all specimens were similar and no polymorphism was detected among them. We conclude that cuttlefish populations cannot be isolated using 18s rRNA gene extracts in the area of study

    Effects of anethum graveolens and garlic on lipid profile in hyperlipidemic patients

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    BACKGROUND: hyperlipidemia as a major risk factor of atherosclerosis is treated with different drugs. Concerning length of therapy and vast majority of side effects, herbal medication may be suitable substitute for these drugs. METHODS: In this single-blind, placebo controlled study, lipid profiles of 150 hyperlipidemic patients in cardiology outpatient department of Shiraz University of Medical Sciences were checked at same conditions. They were divided into three equal groups randomly (each composing of 50 patients). They were given enteric-coated garlic powder tablet (equal to 400 mg garlic, 1 mg allicin) twice daily, anethum tablet (650 mg) twice daily, and placebo tablet. All patients were put on NCEP type Π diet and Six weeks later, lipid profiles were checked. RESULTS: In garlic group: total cholesterol (decreased by 26.82 mg/dl, 12.1% reduction, and P-value: .000), and LDL-cholesterol (decreased by 22.18 mg/dl, 17.3% reduction, and P-value: .000) dropped. HDL-cholesterol (increased by 10.02 mg/dl, 15.7% increase, and P-value: .000) increased. Although triglyceride dropped by 13.72 mg/dl (6.3%) but this was not significant statistically (P-value: .222). In anethum group: surprisingly, triglyceride increased by 14.74 mg/dl (6.0%). Anethum could reduce total cholesterol by 0.4 % and LDL-cholesterol by 6.3% but these were not significant statistically (P-value: .828, and .210, respectively). CONCLUSION: Anethum has no significant effect on lipid profile, but garlic tablet has significant favorable effect on cholesterol, LDL-cholesterol, and HDL-cholesterol. Garlic may play an important role in therapy of hypercholesterolemia

    Estimation growth parameters of Parastromateus niger in the coastal waters of Sistan and Baluchestan, Oman Sea

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    Using length frequency information collected for Parastromateus niger catch in the coastal waters of Sistan and Baluchestan, Oman Sea, we estimated growth parameters of the fish. The data were collected of the fork length of around 887 fish each month during 2001. The length infinity (L∞), growth coefficient (K) and the length at age zero (t0) of the fish measured as 57.8 cm, 0.3 per year and -0.003 respectively. The relationship between the length and weight of the fish was estimated as 0.0469 for “a” , 2.829 for "b" and 0.914 for the correlation coefficient. The average length of the fish in different months of the year calculated and a Tukey test showed that this was significantly different

    Building data warehouses in the era of big data: an approach for scalable and flexible big data warehouses

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    During the last few years, the concept of Big Data Warehousing gained significant attention from the scientific community, highlighting the need to make design changes to the traditional Data Warehouse (DW) due to its limitations, in order to achieve new characteristics relevant in Big Data contexts (e.g., scalability on commodity hardware, real-time performance, and flexible storage). The state-of-the-art in Big Data Warehousing reflects the young age of the concept, as well as ambiguity and the lack of common approaches to build Big Data Warehouses (BDWs). Consequently, an approach to design and implement these complex systems is of major relevance to business analytics researchers and practitioners. In this tutorial, the design and implementation of BDWs is targeted, in order to present a general approach that researchers and practitioners can follow in their Big Data Warehousing projects, exploring several demonstration cases focusing on system design and data modelling examples in areas like smart cities, retail, finance, manufacturing, among others

    Waste sludge from shipping docks as a catalyst to remove amoxicillin in water with hydrogen peroxide and ultrasound

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    The waste sludge from shipping docks contains important elements that can be used as a catalyst after proper processing. The purpose of this study was to remove of amoxicillin (AMX) from the aquatic environment using waste sludge from shipping docks as catalyst in the presence of hydrogen peroxide/ultrasound waves. The catalyst was produced by treating waste sludge at 400 °C for 2 h. N2 adsorption, SEM, XRD, XRF, and FTIR techniques characterized the structural and physical properties of the catalyst. The BET-specific surface area of the catalyst reduced after AMX removal from 4.4 m2/g to 3.6 m2/g. To determine the optimal removal conditions, the parameters of the design of experiments were pH (5–9), contaminant concentration (5–100 mg/L), catalyst dosage (0.5–6 g/L), and concentration of hydrogen peroxide (10–100 mM). The maximum removal of AMX (98%) was obtained in the catalyst/hydrogen peroxide/ultrasound system at pH 5, catalyst dose of 4.5 g/L, H2O2 concentration of 50 mM, AMX concentration of 5 mg/L, and contact time of 60 min. The kinetics of removal of AMX from urine (k = 0.026 1/min), hospital wastewater (k = 0.021 1/min), and distilled water (k = 0.067 1/min) followed a first-order kinetic model (R2>0.91). The catalyst was reused up to 8 times and the AMX removal decreased to 45% in the last use. The byproducts and reaction pathway of AMX degradation were also investigated. The results clearly show that to achieve high pollutant removal rate the H2O2/ultrasound and catalyst/ultrasound synergy plays a key role
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