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Efficient Packet Scheduling technique for Data Merging in Wireless Sensor Networks

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China Communications 2017年第4期14卷 35-46页

作者： V.Akila t.Sheela g.Adiline Macriga Computer Science and Engineering Bharath University Chennai India Information technology Sri Sai Ram Engineering College Chennai India

Wireless Sensor Networks(WSNs) has become a popular research topic due to its resource constraints. Energy consumption and transmission delay is crucial requirement to be handled to enhance the popularity of WSNs. In order to overcome these issues, we have proposed an Efficient Packet Scheduling technique for Data Merging in WSNs. Packet scheduling is done by using three levels of priority queue and to reduce the transmission delay. Real-time data packets are placed in high priority queue and Non real-time data packets based on local or remote data are placed on other queues. In this paper, we have used time Division Multiple Access(tDMA) scheme to efficiently determine the priority of the packet at each level and transmit the data packets from lower level to higher level through intermediate nodes. to reduce the number of transmission, efficient data merge technique is used to merge the data packet in intermediate nodes which has same destination node. Data merge utilize the maximum packet size by appending the merged packets with received packets till the maximum packet size or maximum waiting time is reached. Real-time data packets are directly forwarded to the next node without applying data merge. the performance is evaluated under various metrics like packet delivery ratio, packet drop, energy consumption and delay based on changing the number of nodes and transmission rate. Our results show significant reduction in various performance metrics.

关键词： wireless sensor networks data aggregation packet scheduling time division multiple access

Influence of Quantal and Statistical Fluctuations on Phase transitions in Finite Nuclei

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Communications in theoretical Physics 2011年第10期56卷 718-726页

作者： g.Kanthimathi N.Boomadevi t.R.Rajasekaran R.M.D.Engineering College R.S.M.NagarKavaraipettai-601206Tamil NaduIndia Department of Physics Manonmaniam Sundaranar UniversityTirunelveli-627012Tamil NaduIndia

Investigations on thermal evolution of pairing-phase transition and shape-phase transition in light nuclei are made as a function of pair gap, deformation, temperature and angular momentum using a finite temperature statistical approach with main emphasis to fluctuations. the occurrence of a peak structure in the specific heat predicted as signals of the pairing-phase and shape-phase transitions are reviewed and it is found that they are not actually true phase transitions and it is only an artifact of the mean field models. Since quantal number and spin fluctuations and statistical fluctuations in pair gap, deformation degrees of freedom and energy when incorporated, it wash out the pairing-phase transition and smooth out the shape-phase transition. Phase transitions due to collapse of pair gap and deformation is discussed and a clear picture of pairing-phase transition in light nuclei is presented in which pairing transition is reconciled.

关键词： phase transitions specific heat fluctuations

gA and PSO culled hybrid technique for economic dispatch problem with prohibited operating zones

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第6期8卷 896-903页

作者： SUDHAKARAN M. AJAY-D-VIMALRAJ P. PALANIVELU t.g. ECE Department of Pondicherry University College Pondicherry University Pondicherry 605014 India

this paper presents an efficient and reliable genetic algorithm (gA) based particle swarm optimization (PSO) tech- nique (hybrid gAPSO) for solving the economic dispatch (ED) problem in power systems. the non-linear characteristics of the generators, such as prohibited operating zones, ramp rate limits and non-smooth cost functions of the practical generator operation are considered. the proposed hybrid algorithm is demonstrated for three different systems and the performance is compared with the gA and PSO in terms of solution quality and computation efficiency. Comparison of results proved that the proposed algo- rithm can obtain higher quality solutions efficiently in ED problems. A comprehensive software package is developed using MAtLAB.

关键词： Economic dispatch (ED) genetic algorithm (gA) Particle swarm optimization (PSO) Hybrid gAPSO Prohibited operating zone Crossover Mutation Velocity

Real-time wavelength routing based on Bragg reflection with integrated forward Raman for long-reach networks

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Optoelectronics Letters 2020年第1期16卷 40-44页

作者： g.M.Isoe t.B.gibbon South African Radio Astronomy Observatory(SARAO) Cape Town 7925South Africa Centre for Broadband Communication Nelson Mandela UniversityPort Elizabeth 6031South Africa

We experimentally demonstrate the all-optical efficient technique for dynamic full-duplex wavelength routing and reach extension through adoption of passive fibre Bragg grating(FBg),energy efficient vertical cavity surface emitting lasers(VCSELs)and high gain forward Raman *** this study,two VCSEL channels at 1549.62 nm and 1550.01 nm are directly modulated with a 8.5 gbit/s data signal each,and transmitted over 25.5 km fibre to a passive single mode FBg-based wavelength routing *** precise wavelength selectivity of the FBg is exploited to achieve all-optical real-time wavelength routing of the 1549.62 nm VCSEL channel with a maximum insertion loss of 22.1 *** 1550.01 nm channel is transmitted through the FBg with a maximum penalty of 1.03 *** utilizing the 7.2 dB flat gain of a forward Raman pump,the routed 1549.62 nm VCSEL channel is transmitted over 76.7 km fibre with a maximum penalty of 3.84 dB at bit error rate(BER)of *** technique is all-optical,power efficient as it employs passive FBg and circulators and has low cross talk allied to precise wavelength selectivity of the technique.

关键词： passive pump fibre

StUDY OF RAY IRRADIAtION ON DIAMOND-LIKE CARBON FILMS

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Acta Metallurgica Sinica(English Letters) 2002年第1期15卷 26-32页

作者： g.A. Liu t.M. Wang E.Q Department of Applied Physics Southwest Jiao Tong University Chengdu 610031 China Beijing University of Aeronautics and Astronautics Beijing 100083 China Department of Physics Lanzhou University Lanzhou 730000 China

Diamond-like carbon (DLC) films have been deposited on glass substrates usingradio-frequency (rf) plasma deposition method. gamma -ray, ultraviolet (UV) ray were used toirradiate the DLC films. Raman spectroscopy and infrared (IR) spectroscopy were use to characterizethe changing characteristics of SP^3 C-H bond and hydrogen content in the films due to theirradiations. the results show that, the damage degrees induced by the UV ray on the SP^3 C-H bondsare much stronger than that by the gamma -ray. When the irradiation dose of gamma -ray reaches 1 OX10^4 gy, the SP^3 C-H bond reduces about 50 percent in number. the square electrical resistance ofthe films is reduced due to the irradiation of UV ray and this is caused by severe oxidation of thefilms. By using the results on optical gap of the films and the fully constrained network theory,the hydrogen content in the as-deposited films is estimated to be l0-25at. percent.

关键词： diamond-like carbon film gamma -ray irradiation ultraviolet rayirradiation SP^3 C-H bond infrared transmittance

tRANSIENt FLOWS AND PRESSURE WAVES IN PIPES

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Journal of Hydrodynamics 1995年第2期7卷 51-59页

作者： Wang, Xiuqing Sun, J.g. Sha, W.t. Nuclear Industry Management Inst Beijing China

transient laminar flows and pressure-wave propagation in pipes, commonly called as water hammer, have been analyzed. A pressure-wave equation and a linearized velocity equation were derived from the equations of mass and momentum conservation. the waveform distortion due to viscous dissipation and elastic expansion of pipe wall was characterized by a dimensionless transmission number. the damping coefficients of pressure waves were found to be related to the roots of Bessel function. An exact solution of pressure-wave equation was obtained numerically. the relationship between the distortion of a traveling wave and transmission number was studied. the problem was also calculated with a general-purpose computer code, COMMIX, which solves exact mass conservation equation and Navier-Stokes equations. the computational results of the COMMIX code agreed well with the analytical solutions.

关键词： Computer simulation Differential equations Pipe flow Water wave effects

Inherent EDFA cross-gain saturation functionality for 17 gbit/s PAM-3 all-optical wavelength reuse PON

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Optoelectronics Letters 2020年第2期16卷 122-125页

作者： g.M.Isoe t.B.gibbon South African Radio Astronomy Observatory(SARAO) Cape town 7925South Africa Centre for Broadband Communication Nelson Mandela UniversityPort Elizabeth 6031South Africa

In this work, inherent data-erasing functionality of a saturated erbium doped fibre amplifier(EDFA) is exploited to achieve an all-optical wavelength reuse with pulse amplitude modulation(PAM) format. A 10 gHz bandwidth distributed feedback laser(DFB) is directly modulated with 17 gbit/s PAM-3 data signal and transmitted downstream over a 26.58 km fibre optical line terminal(OLt) incurring a maximum penalty of 1.81 d B. A saturated EDFA deployed at the optical network unit(ONU) terminal is utilized to optically suppress the extinction ratio of residual 17 gbit/s PAM-3 downstream data significantly from 7.1 d B to 830 md B. this facilitates direct reuse of the downstream carrier without the need for an additional electrical data eraser. With the all optical data erasing capability of EDFA over-10 d Bm input power, the carrier re-used upstream transmission successfully delivers 17 gbit/s PAM-3 data with a maximum transmission penalty of 0.99 d B. PAM-3 modulation format maximizes network efficiency by doubling the transmitted bits per symbol. Our technique is all-optical, it can support ultrafast systems with higher modulation formats and is power efficient.

关键词： EDFA network amplifier

Autoheated thermophilic aerobic sludge digestion and metal bioleaching in a two-stage reactor system

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Journal of Environmental Sciences 2010年第2期22卷 230-236页

作者： Rohan Jain Ashish Pathak t.R.Sreekrishnan M.g.Dastidar Department of Biochemical Engineering & Biotechnology Indian Institute of technology Hauz KhasNew Delhi-110016India Centre for Energy Studies Indian Institute of TechnologyHauz KhasNew Delhi-110016India

A two-stage process has been developed for stabilization of sludge and removal of heavy metals from the secondary activated sludge with high rate of energy and time conservation. the first stage of the process involves autoheated thermophilic aerobic digestion at 55-60℃ inoculated with less-acidophilic thermophilic sulfur-oxidizing microorganisms （AtAD）. the results show that it is possible to maintain the autoheated conditions （55-60℃） in the AtAD reactor up to 24 hr, leading to reduction of 21% total solids （tS）, 27% volatile solids （VS）, 27% suspended solids （SS） and 33% volatile suspended solids （VSS） from the sludge. the sludge pH also decreased from 7 to 4.6 due to the activity of less-acidophilic thermophilic microorganisms. In the second stage operation, the digested sludge （pH 4.6, tS 31.6 g/L） from stage one was subjected to bioleaching in a continuous stirred tank reactor, operated at mean hydraulic retention times （HRts） of 12, 24 and 36 hr at 30℃. An HRt of 24 hr was found to be sufficient for removal of 70% Cu, 70% Mn, 75% Ni, and 80% Zn from the sludge. In all, 39% VSS, 76% Cu, 78.2% Mn, 79.5% Ni and 84.2% Zn were removed from the sludge in both the stages.

关键词： bioleaching thermophilic aerobic digestion heavy metals sludge

thermal conductivity of complex materials

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National Science Review 2019年第3期6卷 380-381页

作者： g.Jeffrey Snyder Matthias t.Agne Ramya gurunathan Department of Materials Science and Engineering Northwestern University

In the discussion and analysis of thermal properties (e.g. heat capacity, thermal conductivity) the Debye approximation is typically used to describe the collective behavior of lattice vibrations (phonons) in solid ma... 详细信息

关键词： thermal conductivity of complex materials