388,175 research outputs found
Pay While You Save: Utility-bill Financing for Energy-efficiency Improvements
Utility-bill financing or repayment allows consumers to upgrade their homes and business to be more energy efficientand pay for the work over time through a monthly upgrade fee on their utility bill. Energy savings on gas and electric billsshould outweigh the monthly upgrade fee, depending in part on the length of the payment term and which measures are implemented. Essentially, consumers pay for the upgrade while they save from it
Non-linear effects in electron cyclotron current drive applied for the stabilization of neoclassical tearing modes
Due to the smallness of the volumes associated with the flux surfaces around
the O-point of a magnetic island, the electron cyclotron power density applied
inside the island for the stabilization of neoclassical tearing modes (NTMs)
can exceed the threshold for non-linear effects as derived previously by Harvey
et al, Phys. Rev. Lett. 62 (1989) 426. We study the non-linear electron
cyclotron current drive (ECCD) efficiency through bounce-averaged, quasi-linear
Fokker-Planck calculations in the magnetic geometry as created by the islands.
The calculations are performed for the parameters of a typical NTM
stabilization experiment on ASDEX Upgrade. A particular feature of these
experiments is that the rays of the EC wave beam propagate tangential to the
flux surfaces in the power deposition region. The calculations show significant
non-linear effects on the ECCD efficiency, when the ECCD power is increased
from its experimental value of 1 MW to a larger value of 4 MW. The nonlinear
effects are largest in case of locked islands or when the magnetic island
rotation period is longer than the collisional time scale. The non-linear
effects result in an overall reduction of the current drive efficiency for this
case with absorption of the EC power on the low field side of the electron
cyclotron resonance layer. As a consequence of the non-linear effects, also the
stabilizing effect of the ECCD on the island is reduced from linear
expectations
Progress in AI Planning Research and Applications
Planning has made significant progress since its inception in the 1970s, in terms both of the efficiency and sophistication of its algorithms and representations and its potential for application to real problems. In this paper we sketch the foundations of planning as a sub-field of Artificial Intelligence and the history of its development over the past three decades. Then some of the recent achievements within the field are discussed and provided some experimental data demonstrating the progress that has been made in the application of general planners to realistic and complex problems. The paper concludes by identifying some of the open issues that remain as important challenges for future research in planning
Comparison of Material Properties and Microstructure of Specimens Built Using the 3D Systems Vanguard HS and Vanguard HiQ+HSSLS Systems
The HiQ upgrade to the 3D Systems Vanguard selective laser sintering (SLS) machine incorporates a revised thermal calibration system and new control software. The paper compares
the tensile modulus, tensile strength, elongation at break, flexural modulus, Izod impact resistance and microstructure of two batteries of standard specimens built from recycled Duraform
PA (Nylon 12). The first set is built on a Vanguard HS system and the second on the same
system with the HiQ upgrade installed. The upgrade reduces user intervention, decreases total build time and improves surface finish. However, using the default processing parameters,
tensile, flexure and impact properties are all found to decline after the upgrade is installed.Mechanical Engineerin
Overview of ASDEX Upgrade results
The ASDEX Upgrade (AUG) programme is directed towards physics input to critical elements of the ITER design and the preparation of ITER operation, as well as addressing physics issues for a future DEMO design. Since 2015, AUG is equipped with a new pair of 3-strap ICRF antennas, which were designed for a reduction of tungsten release during ICRF operation. As predicted, a factor two reduction on the ICRF-induced W plasma content could be achieved by the reduction of the sheath voltage at the antenna limiters via the compensation of the image currents of the central and side straps in the antenna frame. There are two main operational scenario lines in AUG. Experiments with low collisionality, which comprise current drive, ELM mitigation/suppression and fast ion physics, are mainly done with freshly boronized walls to reduce the tungsten influx at these high edge temperature conditions. Full ELM suppression and non-inductive operation up to a plasma current of Ip = 0.8 MA could be obtained at low plasma density. Plasma exhaust is studied under conditions of high neutral divertor pressure and separatrix electron density, where a fresh boronization is not required. Substantial progress could be achieved for the understanding of the confinement degradation by strong D puffing and the improvement with nitrogen or carbon seeding. Inward/outward shifts of the electron density profile relative to the temperature profile effect the edge stability via the pressure profile changes and lead to improved/decreased pedestal performance. Seeding and D gas puffing are found to effect the core fueling via changes in a region of high density on the high field side (HFSHD). The integration of all above mentioned operational scenarios will be feasible and naturally obtained in a large device where the edge is more opaque for neutrals and higher plasma temperatures provide a lower collisionality. The combination of exhaust control with pellet fueling has been successfully demonstrated. High divertor enrichment values of nitrogen En > 10 have been obtained during pellet injection, which is a prerequisite for the simultaneous achievement of good core plasma purity and high divertor radiation levels. Impurity accumulation observed in the all-metal AUG device caused by the strong neoclassical inward transport of tungsten in the pedestal is expected to be relieved by the higher neoclassical temperature screening in larger devices.This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018
under grant agreement number 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission.Peer ReviewedPostprint (published version
Generalizing Permissive-Upgrade in Dynamic Information Flow Analysis
Preventing implicit information flows by dynamic program analysis requires
coarse approximations that result in false positives, because a dynamic monitor
sees only the executed trace of the program. One widely deployed method is the
no-sensitive-upgrade check, which terminates a program whenever a variable's
taint is upgraded (made more sensitive) due to a control dependence on tainted
data. Although sound, this method is restrictive, e.g., it terminates the
program even if the upgraded variable is never used subsequently. To counter
this, Austin and Flanagan introduced the permissive-upgrade check, which allows
a variable upgrade due to control dependence, but marks the variable
"partially-leaked". The program is stopped later if it tries to use the
partially-leaked variable. Permissive-upgrade handles the dead-variable
assignment problem and remains sound. However, Austin and Flanagan develop
permissive-upgrade only for a two-point (low-high) security lattice and
indicate a generalization to pointwise products of such lattices. In this
paper, we develop a non-trivial and non-obvious generalization of
permissive-upgrade to arbitrary lattices. The key difficulty lies in finding a
suitable notion of partial leaks that is both sound and permissive and in
developing a suitable definition of memory equivalence that allows an inductive
proof of soundness
The Jefferson Lab 12 GeV Upgrade
Construction of the 12 GeV upgrade to the Continuous Electron Beam
Accelerator Facility (CEBAF) at the Thomas Jefferson National Accelerator
Facility is presently underway. This upgrade includes doubling the energy of
the electron beam to 12 GeV, the addition of a new fourth experimental hall,
and the construction of upgraded detector hardware. An overview of this upgrade
project is presented, along with highlights of the anticipated experimental
program.Comment: 6 pages, 3 figures,Invited Talk compiled for INPC 201
Description of the CUDF Format
This document contains several related specifications, together they describe
the document formats related to the solver competition which will be organized
by Mancoosi. In particular, this document describes: - DUDF (Distribution
Upgradeability Description Format), the document format to be used to submit
upgrade problem instances from user machines to a (distribution-specific)
database of upgrade problems; - CUDF (Common Upgradeability Description
Format), the document format used to encode upgrade problems, abstracting over
distribution-specific details. Solvers taking part in the competition will be
fed with input in CUDF format
The LHCb Upgrade
The LHCb experiment is designed to perform high-precision measurements of CP
violation and search for New Physics using the enormous flux involving beauty
and charm quarks produced at the LHC. The operation and the results obtained
from the data collected in 2010 and 2011 demonstrate that the detector is
robust and functioning very well. However, the limit of 1 fb^-1 of data per
nominal year cannot be overcome without improving the detector. We therefore
plan for an upgraded spectrometer by 2018 with a 40 MHz readout and a much more
flexible software-based triggering system that will increase the data rate as
well as the efficiency specially in the hadronic channels. Here we present the
LHCb detector upgrade plans, based on the Letter of Intent and Framework
Technical Design Report.Comment: Presentation at the DPF 2013 Meeting of the American Physical Society
Division of Particles and Fields, Santa Cruz, California, August 13-17, 201
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