Uncertainty in near-surface wind speed trends at seasonal time scales

Observational studies have identified wind speed trends in the last decades [1,2] attributed to several factors such as changes in the land use, aerosol emissions or atmospheric circulation. However, in spite of the potential impact of this long-term variability in wind energy activities, this type of variability has not been fully characterized yet. As a consequence such information is not currently incorporated in wind power decision-making processes related to planning and management. long-term wind speed variability. For some of these users it is still difficult to identify the most suitable dataset for their specific needs, because a comparison of the quality of the wind speed data from different reanalyses at global scale is not readily available. For this reason, the present study investigates the wind speed long-term trends at global scale in the last decades (1981-2015) using three state-of-the-art reanalyses: ERA-Interim (ERA-I), the Japanese 55-year Reanalysis (JRA-55) and Modern Era Retrospective-Analysis for Research and Applications (MERRA-2)

Lightweight Acquisition and Ranging of Flows in the Data Plane

As networks get more complex, the ability to track almost all the flows is becoming of paramount importance. This is because we can then detect transient events impacting only a subset of the traffic. Solutions for flow monitoring exist, but it is getting very difficult to produce accurate estimations for every tuple given the memory constraints of commodity programmable switches. Indeed, as networks grow in size, more flows have to be tracked, increasing the number of tuples to be recorded. At the same time, end-host virtualization requires more specific flowIDs, enlarging the memory cost for every single entry. Finally, the available memory resources have to be shared with other important functions as well (e.g., load balancing, forwarding, ACL). To address those issues, we present FlowLiDAR (Flow Lightweight Detection and Ranging), a new solution that is capable of tracking almost all the flows in the network while requiring only a modest amount of data plane memory which is not dependent on the size of flowIDs. We implemented the scheme in P4, tested it using real traffic from ISPs and compared it against four state-of-the-art solutions: FlowRadar, NZE, PR-sketch, and Elastic Sketch. While those can only reconstruct up to 60% of the tuples, FlowLiDAR can track 98.7% of them with the same amount of memory

MCU Tolerance in SRAMs through Low Redundancy Triple Adjacent Error Correction

(c) 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.[EN] Static random access memories (SRAMs) are key in electronic systems. They are used not only as standalone devices, but also embedded in application specific integrated circuits. One key challenge for memories is their susceptibility to radiation-induced soft errors that change the value of memory cells. Error correction codes (ECCs) are commonly used to ensure correct data despite soft errors effects in semiconductor memories. Single error correction/double error detection (SEC-DED) codes have been traditionally the preferred choice for data protection in SRAMs. During the last decade, the percentage of errors that affect more than one memory cell has increased substantially, mainly due to multiple cell upsets (MCUs) caused by radiation. The bits affected by these errors are physically close. To mitigate their effects, ECCs that correct single errors and double adjacent errors have been proposed. These codes, known as single error correction/double adjacent error correction (SEC-DAEC), require the same number of parity bits as traditional SEC-DED codes and a moderate increase in the decoder complexity. However, MCUs are not limited to double adjacent errors, because they affect more bits as technology scales. In this brief, new codes that can correct triple adjacent errors and 3-bit burst errors are presented. They have been implemented using a 45-nm library and compared with previous proposals, showing that our codes have better error protection with a moderate overhead and low redundancy.This work was supported in part by the Universitat Politecnica de Valencia, Valencia, Spain, through the DesTT Research Project under Grant SP20120806; in part by the Spanish Ministry of Science and Education under Project AYA-2009-13300-C03; in part by the Arenes Research Project under Grant TIN2012-38308-C02-01; and in part by the Research Project entitled Manufacturable and Dependable Multicore Architectures at Nanoscale within the framework of COST ICT Action under Grant 1103.Saiz-Adalid, L.; Reviriego, P.; Gil, P.; Pontarelli, S.; Maestro, JA. (2015). MCU Tolerance in SRAMs through Low Redundancy Triple Adjacent Error Correction. IEEE Transactions on Very Large Scale Integration (VLSI) Systems. 23(10):2332-2336. https://doi.org/10.1109/TVLSI.2014.2357476S23322336231

The ubiquitin-like modifier FAT10 inhibits retinal PDE6 activity and mediates its proteasomal degradation

The retina-specific chaperone aryl hydrocarbon interacting protein-like 1 (AIPL1) is essential for the correct assembly of phosphodiesterase 6 (PDE6), which is a pivotal effector enzyme for phototransduction and vision because it hydrolyzes cGMP. AIPL1 interacts with the cytokine-inducible ubiquitin-like modifier FAT10, which gets covalently conjugated to hundreds of proteins and targets its conjugation substrates for proteasomal degradation, but whether FAT10 affects PDE6 function or turnover is unknown. Here, we show that FAT10 mRNA is expressed in human retina and identify rod PDE6 as a retina-specific substrate of FAT10 conjugation. We found that AIPL1 stabilizes the FAT10 monomer and the PDE6-FAT10 conjugate. Additionally, we elucidated the functional consequences of PDE6 FAT10ylation. On the one hand, we demonstrate that FAT10 targets PDE6 for proteasomal degradation by formation of a covalent isopeptide linkage. On the other hand, FAT10 inhibits PDE6 cGMP hydrolyzing activity by noncovalently interacting with the PDE6 GAFa and catalytic domains. Therefore, FAT10 may contribute to loss of PDE6 and, as a consequence, degeneration of retinal cells in eye diseases linked to inflammation and inherited blindness-causing mutations in AIPL1

Towards an energy efficient 10 Gb/s optical ethernet: performance analysis and viability

The new IEEE 802.3az Energy Efficient Ethernet (EEE) standard will improve significantly the energy efficiency of 10 Gbps copper transceivers by the introduction of a sleep mode for idle transmission times. The next step towards energy saving seems to be the application of similar concepts to Optical Ethernet, both for short and long range links. To this aim, this paper starts by proposing an analytical model to estimate the energy consumption of a link that uses a sleep-mode power saving mechanism. This model can be useful to answer a number of questions that need to be carefully studied. Otherwise, the complexity of optical components could be increased for the sake of an energy saving that could turn out negligible. In the rest of the paper we analyze three key questions to try to shed some light on this design decision: (a) is the new copper EEE actually outperforming the current regular optical Ethernet in terms of energy saving in such a way that optical PHYs (transceivers) actually need a green upgrade to remain more energy efficient than their copper counterparts? (b) How much energy saving could be actually achieved by EE optical Ethernet? (c) What is the transition time required to achieve a substantial energy saving at medium traffic loads on EE 10 Gb/s optical Ethernet links? The answer to the latter question sets a concrete goal for short-term research in fast on–off laser technology.This work has been supported by a Google Research Award, by the BONE project ("Building the Future Optical Network in Europe"), a Network of Excellence funded by the European Commission through the 7th ICT-Framework Program, by the MEDIANET project and by the Spanish MCINN grants TIN2008-06739-C04-01/TSI and PR2009- 0221. The authors would also like to acknowledge the support for this work from the UC3M-CAM Greencom research grant (under code CCG10-UC3M/TIC- 5624) and TEC2008-02552-E/TEC.Publicad

Increasing the MTU size for Energy Efficiency in Ethernet

Abstract-The commonly used Maximum Transfer Unit (MTU) on the Internet has remained unchanged for many years at around 1500 bytes due mainly to backward compatibility issues. This is in contrast with link data rate, which has increased by several orders of magnitude. In this paper, a new advantage of using larger MTUs is introduced, namely Energy Efficiency. In wire-line environments, the link power consumption is generally roughly independent of the number of frames that are transmitted resulting in a poor energy efficiency. This will change with the development of standards like IEEE 802.3az, Energy Efficient Ethernet. This new standard allows a link to enter a low power mode when there are no frames to transmit therefore making power consumption almost proportional to the link load. In this context the use of larger MTUs minimizes the number of transitions between the active and low power modes thereby improving energy efficiency. The benefits of using larger MTUs in terms of energy efficiency are analyzed in this paper

Novel reaction force for ultra-relativistic dynamics of a classical point charge

The problem of the electromagnetic radiation of an accelerated charged particle is one of the most controversial issues in Physics since the beginning of the last century, representing one of the most popular unsolved problems of the Modern Physics. Different equations of motion have been proposed throughout history for a point charge including the electromagnetic radiation emitted, but all these expressions show some limitations. An equation based on the principle of conservation of energy is proposed in this work for the ultra-relativistic motion. Different examples are analyzed showing that the energy lost by the charge agrees with the Li\'enard formula. This proposed equation has been compared with the Landau-Lifshitz equation obtaining a good agreement in the range of application of the Landau-Lifshitz formula.Comment: 9 pages, 10 figure

Numerical study of dark current dynamics in a high-gradient backward travelling wave accelerating cavity using the electromagnetic simulation software CST studio.

High-Gradient accelerating cavities are one of the main research lines in the development of compact linear colliders. However, the operation of such cavities is currently limited by nonlinear effects that are intensified at high electric fields, such as dark currents and radiation emission or RF breakdowns. A new normal-conducting High-Gradient S-band Backward Travelling Wave accelerating cavity for medical application (v=0.38c) designed and constructed at Conseil Européen pour la Recherche Nucléaire (CERN) is being tested at Instituto de Física Corpuscular (IFIC) High Power RF Laboratory. The objective consists of studying its viability in the development of compact linear accelerators for hadrontherapy treatments in hospitals. Due to the high surface electric field in the cavity, electrons are emitted following Fowler- Nordheim equation, also known as dark currents. The emission and dynamic of these electrons are of fundamental importance on different phenomena such as RF Breakdowns or radiation dose emission. In this work, 3D electromagnetic numerical simulations have been performed using the computer simulation technology software CST Studio Suite. Then, the resulting EM field maps are used to study the emission and electron dynamics inside the cavity. The simulation results are compared with experimental data and first conclusions discussed

Relativistic particle motion of a charge including the radiation reaction

The problem of the electromagnetic radiation of an accelerated charged particle is one of the most controversial issues in Physics since the beginning of the last century representing one of the most popular unsolved problems of the Modern Physics. Different equations of motion for a point charge including the electromagnetic radiation emitted have been proposed throughout history, but all these expressions show some limitations. An equation based on the principle of conservation of energy is proposed for the ultra-relativistic motion. Different examples are analyzed showing that the energy lost by the charge agrees with the relativistic generalization of the Larmor formula. This proposed equation has been compared with the Landau-Lifshitz equation obtaining a good agreement in the range of application of the Landau-Lifshitz formula. Finally, it is discussed a possible variation of the typical relativistic particle integrators (e.g. Boris, Vay or Higuera-Cary methods) in order to include the radiation reaction