Annadurai C.,Anna University |
Computers and Electrical Engineering | Year: 2015
Cooperative ad-hoc networks are popular because of their ability to provide reliable communication. In this paper, we consider a cooperative ad-hoc network consisting of a source, two decode-and-forward relays and a destination. The source intends to transmit its data to the destination directly as well as through relays. We employ a weighted selection combining at the destination which chooses either the weighted source-to-relay1-to-relay2-to-destination link or source-to-destination link depending upon the instantaneous signal-to-noise-ratio. We derive the end-to-end symbol error probability (SEP) of a triple-hop cooperative network with binary phase-shift keying for a flat, slow Rayleigh fading channel. Further, we develop an algorithm which investigates the performance of this cooperative ad-hoc network in terms of SEP. Results show that the cooperation among the nodes and weighted selection combining improves the performance of ad-hoc networks when compared to a point-to-point link and conventional selection combining. © 2015 Elsevier Ltd.
Canada's Prime Minister Justin Trudeau (R) greets Saskatchewan Premier Brad Wall during the First Ministers' meeting in Ottawa, Canada November 23, 2015. Canada's Prime Minister Justin Trudeau (R) greets Ontario Premier Kathleen Wynne during the First Ministers' meeting in Ottawa, Canada November 23 2015. Canada's Prime Minister Justin Trudeau (R) greets Alberta Premier Rachel Notley during the First Ministers' meeting in Ottawa, Canada November 23, 2015. Canada's Prime Minister Justin Trudeau (R) greets Saskatchewan Premier Brad Wall during the First Ministers' meeting in Ottawa, Canada November 23, 2015. Canada's Prime Minister Justin Trudeau (R) greets Ontario Premier Kathleen Wynne during the First Ministers' meeting in Ottawa, Canada November 23, 2015. Canada's Prime Minister Justin Trudeau (R) greets British Columbia Premier Christy Clark during the First Ministers' meeting in Ottawa, Canada November 23, 2015. Canada's Prime Minister Justin Trudeau (R) wears maple leaf-themed socks during the First Ministers' meeting in Ottawa, Canada November 23, 2015. Canada's Prime Minister Justin Trudeau (R) poses with Quebec Premier Philippe Couillard during the First Ministers' meeting in Ottawa, Canada November 23, 2015. Canada's Prime Minister Justin Trudeau speaks during the First Ministers' meeting in Ottawa, Canada November 23, 2015. Canadian Prime Minister Justin Trudeau gestures as he speaks during a news conference after attending the 21-member Asia-Pacific Economic Cooperation (APEC) Summit in Manila November 19, 2015. Saskatchewan Premier Brad Wall (L) speaks during a news conference with Canada's Prime Minister Justin Trudeau at the First Ministers' meeting in Ottawa, Canada November 23, 2015. Canada's Prime Minister Justin Trudeau (6th R) poses with provincial and territorial premiers during the First Ministers' meeting in Ottawa, Canada November 23, 2015. Also pictured are L-R Nunavut Premier Peter Taptuna, Alberta Premier Rachel Notley, Prince Edward Island... Trudeau's Liberals won an election last month promising radical change on the environment from the previous Conservative administration, which was widely criticized for not doing enough to combat global warming during its near decade in power. Trudeau, who will attend a United Nations environmental summit in Paris next week, says Canada must curb its emissions of greenhouse gases. "In Paris a united Canada will demonstrate that we are serious about climate change," Trudeau told a late-night news conference after meeting with premiers of the 10 provinces and three territories. Alberta, home to most of Canada's oil sands, said on Sunday in a ground-breaking move that it would implement an economy-wide tax on carbon emissions in 2017. Trudeau and the provinces hope their united approach and Alberta's move will help dispel some of the international suspicion about Canada and climate change. At previous U.N. summits the Conservative government sometimes found itself openly at odds with activist groups and even some provinces. Those days were over, said Trudeau. "We need to show a renewed image of Canada to the world," said Quebec premier Philippe Couillard. Some premiers are nervous about the idea. Brad Wall of Saskatchewan says Canada must find a balance between the environment and protecting employment. "As we prepare for Paris and to present a constructive and national front to the world, we just need to be mindful of that fact," he told the closing news conference. Although the Conservatives had pledged to cut greenhouse gas emissions to 30 percent below 2005 levels by 2030, government figures show rising emissions mean the goal is out of reach. Trudeau will not be going to Paris with a new target, but has committed to coming up with a goal with the provinces within 90 days of returning from the talks. Two government scientists told the strategy meeting that Canada's rate of warming was about twice the global rate. This means hotter summers with more forest fires, melting permafrost and a smaller Arctic ice cover that will force polar bears onto land as they search for food, they said.
News Article | November 23, 2015
A new report from the New Climate Economy highlights lessons learned from 15 countries who have undertaken reforms of fossil fuel subsidy policy. The paper, Fossil Fuel Subsidy Reform: From Rhetoric to Reality, was partly responsible for the 2015 New Climate Economy report, and now goes further in an effort to articulate “practical steps that policymakers can take to phase out fossil fuel subsidies” — a vital discussion in the lead up to the UN climate conference set to be held in Paris at the end of this month. The report examines what has worked and what hasn’t in attempts to reform fossil fuel subsidy policy, and provides “in-depth case studies of 15 countries.” “Phasing out fossil fuel subsidies offers both economic and climate gains,” said Ngozi Okonjo-Iweala, former finance minister of Nigeria and a member of the Global Commission on the Economy and Climate. “Reform could allow for targeted spending on public services for those who need it most and boost economic efficiency. And on the climate front, it could deliver global greenhouse gas emissions reductions of as much as 13% by 2050. Undertaking subsidy reform – and getting it right – is critical for better growth and better climate.” Over the past year we have seen numerous reports published identifying the extent to which industrialized nations around the world are supporting the fossil fuel industry with government-backed subsidies. The latest of these reports was published earlier this month by the Overseas Development Institute (ODI) and Oil Change Institute (OCI), and found that G20 nations are spending $452 billion on fossil fuel subsidies per year. “G20 governments are paying fossil fuel producers to undermine their own policies on climate change,” said Shelagh Whitley, of the Overseas Development Institute. “Scrapping these subsidies would rebalance energy markets and allow a level playing field for clean and efficient alternatives.” The latest report by the New Climate Economy forecasts worldwide governments will spend $650 billion funding fossil fuel subsidies in 2015. “Fossil fuel subsidies create significant burdens on government budgets, taking up as much as 5% of GDP in as many as 40 countries, often more than is spent on health or education,” said Helen Mountford, Program Director of the New Climate Economy. “Removing these subsidies can spur a virtuous circle, freeing up scarce government funds to be spent on other critical priorities, including better targeted support for the poor.” Specifically, in an attempt to provide clear principles for reforming fossil fuel subsidy policy, the report identifies the following steps: “The G20 and APEC have committed to phasing out inefficient fossil fuel subsidies, but most haven’t yet delivered,” added Shelagh Whitely, lead author of the report and a Research Fellow at the Overseas Development Institute. “They should follow the positive examples of change and scale reforms to eliminate fossil fuel subsidies by no later than 2025. In a time when low oil prices are expected to continue and many governments are looking to create fiscal space, there’s no excuse to delay phasing out fossil fuel subsidies any longer.” The full report is available here (PDF) Get CleanTechnica’s 1st (completely free) electric car report → “Electric Cars: What Early Adopters & First Followers Want.” Come attend CleanTechnica’s 1st “Cleantech Revolution Tour” event → in Berlin, Germany, April 9–10. Keep up to date with all the hottest cleantech news by subscribing to our (free) cleantech newsletter, or keep an eye on sector-specific news by getting our (also free) solar energy newsletter, electric vehicle newsletter, or wind energy newsletter.
Natural Hazards | Year: 2010
Iso-intensity contour maps were calculated on the basis of the intensity data derived from historical information about strongest earthquakes in Mexico. Intensity data contain a great deal of information that can be used to constrain the essential characteristics of the seismic source. In particular, both the seismological theory and its practice suggest that the orientation of the source of significant earthquakes is reflected in the elongation of the associated damage pattern. The present paper uses information about historical seismicity in Mexico from 1568 to 1837 to point out the sites, where the strongest damages took place. After information selection, maps of iso-intensities were built to determine epicentres. This information was interpreted, and damages and major risk zones were mapped. The systematic application of this method to all the M > 5.5 earthquakes that occurred in Mexico in the past five centuries produced encouraging results about the determination of the seismic source parameters that compare well with existing instrumental, geological, and geodynamic evidence. © 2010 Springer Science+Business Media B.V.
Mari J.L.,French Institute of Petroleum |
Gaudiani P.,APEC |
Delay J.,Andra Inc
Physics and Chemistry of the Earth | Year: 2011
In this paper, we will show through a field example that full wave form acoustic logging allows a quantitative evaluation of geological formations. For that purpose, conventional logs and their associated standard deviation (Std) must be computed (formation velocities, amplitudes, frequencies, etc.) since the Std is used to estimate the uncertainties associated with the log and to edit other logs. The missing values are then reconstructed by geostatistical interpolation (ordinary kriging and co-kriging). The shear velocity and density of the formation are also estimated in order to obtain mechanical parameters such as Poisson's ratio or shear modulus. Since the converted refracted shear waves can be recorded in fast formations, a joint method based on the local measurement of the shear velocity by picking the arrival times of the refracted S wave and interpolation by co-kriging with P-wave velocity log has been used to compute a continuous shear velocity log. The Analysis of the dispersive properties of the Stoneley modes has then been used to estimate density variations and build iteratively a density log from an a priori density model. Furthermore, we will show that a dimensionless shape index can be used as a qualitative acoustic attribute to detect the presence of interfering waves, anomalic zones and to obtain a measurement of the attenuation. We will also show that P-wave attenuation, P-wave frequency and acoustic porosity logs can be fruitfully used to compute an acoustic permeability log. © 2011 Elsevier Ltd.