1,006 research outputs found

    Hybrid Coding Technique for Pulse Detection in an Optical Time Domain Reflectometer

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    The paper introduces a novel hybrid coding technique for improved pulse detection in an optical time domain reflectometer. The hybrid schemes combines Simplex codes with signal averaging to articulate a very sophisticated coding technique that considerably reduces the processing time to extract specified coding gains in comparison to the existing techniques. The paper quantifies the coding gain of the hybrid scheme mathematically and provide simulative results in direct agreement with the theoretical performance. Furthermore, the hybrid scheme has been tested on our self-developed OTDR

    Predicting parking space availability based on heterogeneous data using Machine Learning techniques

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    Abstract. These days, smart cities are focused on improving their services and bringing quality to everyday life, leveraging modern ICT technologies. For this reason, the data from connected IoT devices, environmental sensors, economic platforms, social networking sites, governance systems, and others can be gathered for achieving such goals. The rapid increase in the number of vehicles in major cities of the world has made mobility in urban areas difficult, due to traffic congestion and parking availability issues. Finding a suitable parking space is often influenced by various factors such as weather conditions, traffic flows, and geographical information (markets, hospitals, parks, and others). In this study, a predictive analysis has been performed to estimate the availability of parking spaces using heterogeneous data from Cork County, Ireland. However, accumulating, processing, and analysing the produced data from heterogeneous sources is itself a challenge, due to their diverse nature and different acquisition frequencies. Therefore, a data lake has been proposed in this study to collect, process, analyse, and visualize data from disparate sources. In addition, the proposed platform is used for predicting the available parking spaces using the collected data from heterogeneous sources. The study includes proposed design and implementation details of data lake as well as the developed parking space availability prediction model using machine learning techniques

    Holistic Influence Maximization: Combining Scalability and Efficiency with Opinion-Aware Models

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    The steady growth of graph data from social networks has resulted in wide-spread research in finding solutions to the influence maximization problem. In this paper, we propose a holistic solution to the influence maximization (IM) problem. (1) We introduce an opinion-cum-interaction (OI) model that closely mirrors the real-world scenarios. Under the OI model, we introduce a novel problem of Maximizing the Effective Opinion (MEO) of influenced users. We prove that the MEO problem is NP-hard and cannot be approximated within a constant ratio unless P=NP. (2) We propose a heuristic algorithm OSIM to efficiently solve the MEO problem. To better explain the OSIM heuristic, we first introduce EaSyIM - the opinion-oblivious version of OSIM, a scalable algorithm capable of running within practical compute times on commodity hardware. In addition to serving as a fundamental building block for OSIM, EaSyIM is capable of addressing the scalability aspect - memory consumption and running time, of the IM problem as well. Empirically, our algorithms are capable of maintaining the deviation in the spread always within 5% of the best known methods in the literature. In addition, our experiments show that both OSIM and EaSyIM are effective, efficient, scalable and significantly enhance the ability to analyze real datasets.Comment: ACM SIGMOD Conference 2016, 18 pages, 29 figure

    Exhaust Plume Flow Visualization for Qualitative Analysis of Engine Combustion Performance

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    This work explores use of Thermal Infrared Image based Flow Visualization (TIIFV) for qualitative analysis of gasoline engine combustion performance. It proposes determining engine combustion performance through analysis of the exhaust plume turbulence and radiation extinction patterns. The employed methodology requires estimating the point spread function (PSF) prevailing in a LWIR image and using the PSF estimates for enhancing the engine exhaust plume LWIR images. Influence of exhaust plume composition on the plume flow characteristics, made evident by the turbulence and radiation extinction patterns, is then ascertained. The observed plume flow characteristics and underlying flow patterns are used to qualitatively determine the engine combustion performance. Results suggest that engine exhaust flow visualization can help in qualitative analysis of combustion performance from a distance and our reliance on photochemical-based analysis of gasoline engine combustion efficiency can be reduced. Thus a time consuming and untidy process, difficult to be carried out in real life situations, may be replaced with a swift and cleaner one

    Going Against the Grain of Optimism: Flour Fortification in Pakistan

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    Food fortification is a popular strategy for addressing ‘hidden hunger’, and staple foods are seen as promising, if unproven, vehicles for the delivery of essential micronutrients to poor people in developing countries. This article examines wheat flour fortification with iron in Pakistan as a case of technocratic optimism in the face of institutional constraints. An evaluative framework based on the analysis of entire value chains can provide a reality check on technocratic optimism. We find that poor people based their preferences for different types of flour on price as well as perceptions of nutritional value. Many of these flour types are not covered by fortification programmes. Fortification interventions, meanwhile, have attempted to leverage public–private partnerships in a segment of the wheat flour value chain which is beset with regulatory weakness. This article illustrates why technical interventions should support rather than ignore a broader agenda of reforms in food policy.Department for International Development (DFID

    tert-Butyl N-[1-diazo­acetyl-3-(methyl­sulfan­yl)prop­yl]carbamate

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    In the enanti­omerically pure title compound, C11H19N3O3S, the chain C—N—C(O)—O—C—C (from the asymmetric carbon to a methyl of the tert-butyl group) displays an extended conformation. In the crystal, mol­ecules are linked into chains parallel to the c axis by classical N—H⋯Odiazo­carbon­yl hydrogen bonding and an unusual inter­molecular three-centre inter­action involving the amino acid (aa) carbonyl Oaa and the diazo­carbonyl grouping C(O)—CH—N N, with H⋯Oaa = 2.51 Å and N⋯Oaa = 2.8141 (14) Å

    C and S induces changes in the electronic and geometric structure of Pd(533) and Pd(320)

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    We have performed ab initio electronic structure calculations of C and S adsorption on two vicinal surfaces of Pd with different terrace geometry and width. We find both adsorbates to induce a significant perturbation of the surface electronic and geometric structure of Pd(533) and Pd(320). In particular C adsorbed at the bridge site at the edge of a Pd chain in Pd(320) is found to penetrate the surface to form a sub-surface structure. The adsorption energies show almost linear dependence on the number of adsorbate-metal bonds, and lie in the ranges of 5.31eV to 8.58eV for C and 2.89eV to 5.40eV for S. A strong hybridization between adsorbate and surface electronic states causes a large splitting of the bands leading to a drastic decrease in the local densities of electronic states at the Fermi-level for Pd surface atoms neighboring the adsorbate which may poison catalytic activity of the surface. Comparison of the results for Pd(533) with those obtained earlier for Pd(211) suggests the local character of the impact of the adsorbate on the geometric and electronic structures of Pd surfaces.Comment: 14 pages 9 figs, Accepted J. Phys: Conden

    To Perform Thrombolysis or Not: A Case of Acute Pancreatitis Presenting with Chest Pain and Transient Left Bundle Branch Block

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    A suspected case of acute coronary syndrome presented with new-onset left bundle branch and first-degree heart blocks. The decision to thrombolyse was reverted as ECG changes proved to be transient within fifteen minutes of presentation. Later on the patient was diagnosed with acute pancreatitis based on laboratory results of serum amylase, confirmed on radiological investigations

    Studies on the antihypertensive and antidyslipidemic activities of Viola odorata leaves extract

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    <p>Abstract</p> <p>Background</p> <p>This study was undertaken to provide pharmacological basis for the medicinal use of <it>Viola odorata </it>Linn. in hypertension and dyslipidemia using the <it>in vivo </it>and <it>in vitro </it>assays.</p> <p>Results</p> <p><it>Viola odorata </it>leaves extract (Vo.Cr), which tested positive for alkaloids, saponins, tannins, phenolics, coumarins and flavonoids, caused a dose-dependent (0.1-1.0 mg/kg) decrease in mean arterial blood pressure in anaesthetized rats. In isolated guinea-pig atria, Vo.Cr equally inhibited force and rate of spontaneous atrial contractions. On the baseline of rat thoracic aortae (endothelium-intact and denuded), the plant extract caused phentolamine-sensitive vasoconstriction. When tested on phenylephrine (PE, 1 μM) and K<sup>+ </sup>(80 mM)-induced vasoconstriction, Vo.Cr caused a concentration-dependent relaxation and also caused a rightward shift of Ca<sup>++ </sup>concentration-response curves as well as suppression of PE (1 μM) control peaks in Ca<sup>++</sup>-free medium, similar to that caused by verapamil. In the presence of L-NAME, the relaxation curve of Vo.Cr was partially inhibited showing involvement of Nitric oxide (NO) mediated pathway. In Tyloxapol-induced dyslipidemia, Vo.Cr caused reduction in total cholesterol and triglyceride levels. In high-fat diet-induced dyslipidemia model, the plant extract caused a significant decrease in total cholesterol, LDL-C, atherogenic index and prevented the increase in average body weights, while it increased HDL-C.</p> <p>Conclusions</p> <p>These data indicate that the vasodilator effect of the plant extract is mediated through multiple pathways like inhibition of Ca<sup>++ </sup>influx via membranous Ca<sup>++ </sup>channels, its release from intracellular stores and NO-mediated pathways, which possibly explain the fall in BP. The plant also showed reduction in body weight and antidyslipidemic effect which may be due to the inhibition of synthesis and absorption of lipids and antioxidant activities. Thus, this study provides a pharmacologic rationale to the medicinal use of <it>Viola odorata </it>in hypertension and dyslipidemia.</p
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