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51.
Ranganathan Radha Somanathan Bhuvaneswari Kannan Kathiravan 《Wireless Personal Communications》2020,110(3):1533-1549
Wireless Personal Communications - Wireless sensor networks (WSN) consist of large number of sensor nodes that work collaboratively. Sensors segregate groups with similar traits and get arranged in... 相似文献
52.
Using signal processing techniques to model worm propagation over wireless sensor networks 总被引:3,自引:0,他引:3
This paper describes how a topologically aware worm propagation model (TWPM) for wireless sensor networks is formulated and derived. The paper defines worm propagation characteristics that are specific to sensor networks. It also parameterize the effects of physical channel conditions, medium access control (MAC) layer contention, network layer routing, and transport layer protocol on worm propagation in sensor networks. The basic model formulation results in a partial differential equation, which is solved in the frequency domain to yield a closed-form solution for the TWPM. It is shown that in the spatial domain, the TWPM spread function is low-pass filtered by a two-dimensional isotropic Gaussian filter, thereby providing an intuitive feel for the dependence of the model on its underlying parameters. Simulation results demonstrate that the TWPM provides an effective and accurate worm propagation model for sensor networks 相似文献
53.
Nanduri Gayatri Devi Nanduri Veera Naga Bala Srinivasa Rao Maganti Radha Sirija Dittakavi Ramachandran 《Korean Journal of Chemical Engineering》2018,35(7):1488-1499
Densities ‘ρ’, ultrasonic speeds of sound ‘u’ of binary mixtures of propiophenone (PPH) with aniline, N-Methylaniline, N,N-dimethylaniline and N,N-diethylaniline were measured over the entire composition range from 303.15 K to 318.15 K and at atmospheric pressure 0.1 MPa. Experimental data of ultrasonic sound were compared and discussed with the computed values of ‘u’ from various velocity theories like Nomoto’s relation (UNOM), impedance relation (UIMP), Van Dael and Vangeel’s ideal mix relation (UVDV), Rao’s specific velocity relation (URAO), Junjie’s theory (UJUN) and Jouyban-Acree’s (UJOE) relation for the above binary mixtures over the entire mole fraction range at the studied temperatures. The results are satisfactory and are in agreement between the theoretical and the experimental values. Further, the molecular interaction parameter (α), average percentage error and Chi-square test values were computed by using the values of experimental and theoretical ultrasonic velocities. The Δu values were correlated with Redlich-Kister polynomial equation to compute the coefficients and the standard deviations of the binary mixtures. The results were analyzed in terms of intermolecular interactions. 相似文献
54.
随着在线社会关系网络的迅猛发展,每天数以千万计的人通过发表、评论、分享等方式,产生和传播各类话题.对在线社会关系数据的感知与收集、存储管理、群体行为等进行研究,能更好地挖掘和分析社会关系网络.由于微博平台的登录、数据显示与处理等方面与传统网络平台有很大差异,传统网络爬虫不适于对微博信息的全面抓取.本文采用模拟用户浏览行为方法来爬取海量微博数据,通过数据包截取与分析等手段获取相关信息.实验结果表明该方法的有效性.在此基础上,以收集的微博数据为研究对象,对群体行为进行了分析. 相似文献
55.
56.
Radical Roles for RAGE in the Pathogenesis of Oxidative Stress in Cardiovascular Diseases and Beyond
Gurdip Daffu Carmen Hurtado del Pozo Karen M. O’Shea Radha Ananthakrishnan Ravichandran Ramasamy Ann Marie Schmidt 《International journal of molecular sciences》2013,14(10):19891-19910
Oxidative stress is a central mechanism by which the receptor for advanced glycation endproducts (RAGE) mediates its pathological effects. Multiple experimental inquiries in RAGE-expressing cultured cells have demonstrated that ligand-RAGE interaction mediates generation of reactive oxygen species (ROS) and consequent downstream signal transduction and regulation of gene expression. The primary mechanism by which RAGE generates oxidative stress is via activation of NADPH oxidase; amplification mechanisms in the mitochondria may further drive ROS production. Recent studies indicating that the cytoplasmic domain of RAGE binds to the formin mDia1 provide further support for the critical roles of this pathway in oxidative stress; mDia1 was required for activation of rac1 and NADPH oxidase in primary murine aortic smooth muscle cells treated with RAGE ligand S100B. In vivo, in multiple distinct disease models in animals, RAGE action generates oxidative stress and modulates cellular/tissue fate in range of disorders, such as in myocardial ischemia, atherosclerosis, and aneurysm formation. Blockade or genetic deletion of RAGE was shown to be protective in these settings. Indeed, beyond cardiovascular disease, evidence is accruing in human subjects linking levels of RAGE ligands and soluble RAGE to oxidative stress in disorders such as doxorubicin toxicity, acetaminophen toxicity, neurodegeneration, hyperlipidemia, diabetes, preeclampsia, rheumatoid arthritis and pulmonary fibrosis. Blockade of RAGE signal transduction may be a key strategy for the prevention of the deleterious consequences of oxidative stress, particularly in chronic disease. 相似文献
57.
Shirish S. Karande Hayder Radha 《Multimedia, IEEE Transactions on》2007,9(2):307-319
Many recently proposed cross-layer protocols for wireless video, have advocated the relay of corrupted packet to higher layers. Such protocols lead to both errors and erasures at the compressed video application layer. We generically refer to such schemes as hybrid erasure-error protocols (HEEPs). In this paper, we analyze the utility of HEEPs for efficient transmission of video over wireless channels. In order to maintain the generic nature of the deductions in this paper, we base our analysis on two (rather abstract) communication schemes for wireless video: hybrid error-erasure cross-layer design (CLD) and hybrid error-erasure cross-layer design with side-information (CLDS). We make a comparative analysis of the channel capacities of these schemes over single and multi-hop wireless channels to identify the conditions under which the HEEPs can provide improved performance over conventional (CON) protocols. In addition, we employ Reed Solomon (RS) and low-density parity check (LDPC)-code-based forward-error correction (FEC) schemes to illustrate that the improvement in capacity can easily enable an FEC scheme employed in conjunction with a HEEP to provide improved throughput. Finally we compare the performance of CON, CLD, and CLDS in terms of video quality using the H.264 video standard. The simulation results show a significant advantage for the HEEPs 相似文献
58.
Florence Gnana Poovathy J. Radha S. Suganesh V. 《Multidimensional Systems and Signal Processing》2019,30(2):921-941
Multidimensional Systems and Signal Processing - Non-iterative compressed sensing (CS) based recovery algorithms have been proposed in the recent years that efficiently recover the input from CS... 相似文献
59.
60.
Aradhya SV Meisner JS Krikorian M Ahn S Parameswaran R Steigerwald ML Nuckolls C Venkataraman L 《Nano letters》2012,12(3):1643-1647
Electronic factors in molecules such as quantum interference and cross-conjugation can lead to dramatic modulation and suppression of conductance in single-molecule junctions. Probing such effects at the single-molecule level requires simultaneous measurements of independent junction properties, as conductance alone cannot provide conclusive evidence of junction formation for molecules with low conductivity. Here, we compare the mechanics of the conducting para-terminated 4,4'-di(methylthio)stilbene and moderately conducting 1,2-bis(4-(methylthio)phenyl)ethane to that of insulating meta-terminated 3,3'-di(methylthio)stilbene single-molecule junctions. We simultaneously measure force and conductance across single-molecule junctions and use force signatures to obtain independent evidence of junction formation and rupture in the meta-linked cross-conjugated molecule even when no clear low-bias conductance is measured. By separately quantifying conductance and mechanics, we identify the formation of atypical 3,3'-di(methylthio)stilbene molecular junctions that are mechanically stable but electronically decoupled. While theoretical studies have envisaged many plausible systems where quantum interference might be observed, our experiments provide the first direct quantitative study of the interplay between contact mechanics and the distinctively quantum mechanical nature of electronic transport in single-molecule junctions. 相似文献