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Accelerating the Payment of PACE Assessments By Mark Zimring and Merrian Fulle

Description: The 'acceleration' of land-secured assessments allows municipalities to declare the entire value (not just the late payments) of a property owner's outstanding balance payable if a default occurs. State laws vary on whether acceleration is required, permitted, or prohibited. Acceleration can be attractive to bond investors because it strips out non-performing assessments, and may avoid delays in debt service payments to investors. The risk that non-acceleration will negatively impact bond investors is a particular issue in states without a process for rapidly resolving defaults. However, acceleration may also increase the risk to mortgage holders, as the full amount of the outstanding assessment becomes due and traditionally has priority over other lien holders. Acceleration also places a greater burden on the property owner.
Date: May 4, 2010
Creator: Zimring, Mark & Fuller, Merrian
Partner: UNT Libraries Government Documents Department

Architecture Concepts and Technical Issues for an Open,Interoperable Automated Demand Response Infrastructure

Description: This paper presents the technical and architectural issues associated with automating Demand Response (DR) programs. The paper focuses on a description of the Demand Response Automation Server (DRAS), which is the main component used to automate the interactions between the Utilities and their customers for DR programs. Use cases are presented that show the role of the DRAS in automating various aspects of DR programs. This paper also describes the various technical aspects of the DRAS including its interfaces and major modes of operation. This includes how the DRAS supports automating such Utility/Customer interactions as automated DR bidding, automated DR event handling, and finally real-time pricing.
Date: October 1, 2007
Creator: Koch, Ed & Piette, Mary Ann
Partner: UNT Libraries Government Documents Department

ATLAS TrackingEvent Data Model -- 12.0.0

Description: In this report the event data model (EDM) relevant for tracking in the ATLAS experiment is presented. The core component of the tracking EDM is a common track object which is suited to describe tracks in the innermost tracking sub-detectors and in the muon detectors in offline as well as online reconstruction. The design of the EDM was driven by a demand for modularity and extensibility while taking into account the different requirements of the clients. The structure of the track object and the representation of the tracking-relevant information are described in detail.
Date: July 23, 2006
Creator: ATLAS; Akesson, F.; Atkinson, T.; Costa, M.J.; Elsing, M.; Fleischmann, S. et al.
Partner: UNT Libraries Government Documents Department

DNAPL invasion into a partially saturated dead-end fracture

Description: The critical height for DNAPL entry into a partially watersaturated, dead-end fracture is derived and compared to laboratoryobservations. Experiments conducted in an analog, parallel-plate fracturedemonstrate that DNAPL accumulates above the water until the height ofthe DNAPL overcomes the sum of the capillary forces at the DNAPL-airinterface and at the DNAPL-water interface. These experiments also showthat DNAPL preferentially enters the water at locations where DNAPL haspreviously entered, and the entry heights for these subsequent entriesare lower than the heights measured for the initial invasion. The wettingcontact angle at the DNAPL-water interface becomes larger at thelocations where the DNAPL has already entered the water because ofresidual DNAPL on the fracture walls, which results in lowering thecritical entry height at those locations. The experiments alsodemonstrate that a DNAPL lens can remain nearly immobile above the waterfor a period of time before eventually redistributing itself and enteringthe water.
Date: June 17, 2004
Creator: gwsu@lbl.gov
Partner: UNT Libraries Government Documents Department

BDDC for nonsymmetric positive definite and symmetric indefinite problems

Description: The balancing domain decomposition methods by constraints are extended to solving both nonsymmetric, positive definite and symmetric, indefinite linear systems. In both cases, certain nonstandard primal constraints are included in the coarse problems of BDDC algorithms to accelerate the convergence. Under the assumption that the subdomain size is small enough, a convergence rate estimate for the GMRES iteration is established that the rate is independent of the number of subdomains and depends only slightly on the subdomain problem size. Numerical experiments for several two-dimensional examples illustrate the fast convergence of the proposed algorithms.
Date: December 10, 2008
Creator: Tu, Xuemin & Li, Jing
Partner: UNT Libraries Government Documents Department

Fast marching methods for the continuous traveling salesman problem

Description: We consider a problem in which we are given a domain, a cost function which depends on position at each point in the domain, and a subset of points ('cities') in the domain. The goal is to determine the cheapest closed path that visits each city in the domain once. This can be thought of as a version of the Traveling Salesman Problem, in which an underlying known metric determines the cost of moving through each point of the domain, but in which the actual shortest path between cities is unknown at the outset. We describe algorithms for both a heuristic and an optimal solution to this problem. The order of the heuristic algorithm is at worst case M * N logN, where M is the number of cities, and N the size of the computational mesh used to approximate the solutions to the shortest paths problems. The average runtime of the heuristic algorithm is linear in the number of cities and O(N log N) in the size N of the mesh.
Date: December 1, 2008
Creator: Andrews, J. & Sethian, J.A.
Partner: UNT Libraries Government Documents Department

A Three-level BDDC algorithm for saddle point problems

Description: BDDC algorithms have previously been extended to the saddle point problems arising from mixed formulations of elliptic and incompressible Stokes problems. In these two-level BDDC algorithms, all iterates are required to be in a benign space, a subspace in which the preconditioned operators are positive definite. This requirement can lead to large coarse problems, which have to be generated and factored by a direct solver at the beginning of the computation and they can ultimately become a bottleneck. An additional level is introduced in this paper to solve the coarse problem approximately and to remove this difficulty. This three-level BDDC algorithm keeps all iterates in the benign space and the conjugate gradient methods can therefore be used to accelerate the convergence. This work is an extension of the three-level BDDC methods for standard finite element discretization of elliptic problems and the same rate of convergence is obtained for the mixed formulation of the same problems. Estimate of the condition number for this three-level BDDC methods is provided and numerical experiments are discussed.
Date: December 10, 2008
Creator: Tu, X.
Partner: UNT Libraries Government Documents Department

Phase patterns of coupled oscillators with application to wireless communication

Description: Here we study the plausibility of a phase oscillators dynamical model for TDMA in wireless communication networks. We show that emerging patterns of phase locking states between oscillators can eventually oscillate in a round-robin schedule, in a similar way to models of pulse coupled oscillators designed to this end. The results open the door for new communication protocols in a continuous interacting networks of wireless communication devices.
Date: January 2, 2008
Creator: Arenas, A.
Partner: UNT Libraries Government Documents Department

Multiscale integration schemes for jump-diffusion systems

Description: We study a two-time-scale system of jump-diffusion stochastic differential equations. We analyze a class of multiscale integration methods for these systems, which, in the spirit of [1], consist of a hybridization between a standard solver for the slow components and short runs for the fast dynamics, which are used to estimate the effect that the fast components have on the slow ones. We obtain explicit bounds for the discrepancy between the results of the multiscale integration method and the slow components of the original system.
Date: December 9, 2008
Creator: Givon, D. & Kevrekidis, I.G.
Partner: UNT Libraries Government Documents Department

HELIUM THREE

Description: A review is given of the present state of knowledge concerning the condensed phases of He{sup 3}. Attention is confined to the pure substance, and emphasis is placed upon the theoretical understanding of the material.
Date: September 11, 1962
Creator: Sessler, Andrew M.
Partner: UNT Libraries Government Documents Department

Magnetic structure near the Co/NiO(001) interface

Description: We investigate the magnetic coupling at the Co/NiO interface using soft x-ray magnetic linear dichroism (XMLD) and circular dichroism taking explicitly into account the recently observed angular dependence of the XMLD with respect to the crystallographic axes. We find that the Co moments are aligned perpendicular to the NiO moments. We discuss the impact of the anisotropic XMLD on the intensity ratio of the two peaks at the Ni L{sub 2} edge, which is commonly employed to determine the spin orientation in antiferromagnets using XMLD.
Date: August 29, 2008
Creator: Arenholz, Elke; van der Laan, Gerrit & Nolting, Frithjof
Partner: UNT Libraries Government Documents Department

Bounding CKM Mixing with a Fourth Family

Description: CKM mixing between third family quarks and a possible fourth family is constrained by global fits to the precision electroweak data. The dominant constraint is from nondecoupling oblique corrections rather than the vertex correction to Z {yields} {bar b}b used in previous analyses. The possibility of large mixing suggested by some recent analyses of FCNC processes is excluded, but 3-4 mixing of the same order as the Cabbibo mixing of the first two families is allowed.
Date: April 22, 2009
Creator: Chanowitz, Michael S.
Partner: UNT Libraries Government Documents Department

Interium Report on An Exact Analysis of a Limited Plane Plasma in a Magnetic Field

Description: Prior analyses of a plasma in a magnetic field have been limited, as far as the writer is aware, to cases in which the relative change in field over the orbital distance and the relative change in ion concentration are both small, or in which the relations have been viewed in a purely hydrodynamical way. The first approach excludes cases which can be of considerable interest, for it fails for a plasma edge. The second loses all sight of the structure imposed by the orbital motions.
Date: January 1, 1947
Creator: Tonka, Lewi
Partner: UNT Libraries Government Documents Department

Comment regarding"On the Crooks fluctuation theorem and the Jarzynski equality" [J. Chem. Phys. 129, 091101 (2008)]and"Nonequilibrium fluctuation-dissipation theorem of Brownian dynamics" [J. Chem. Phys. 129, 144113 (2008)]

Description: The incongruous"unexpected inapplicability of the [Crook's fluctuation theorem]" is due to an inexplicable, inappropriate use of inconsistent expressions. The girding is secure.
Date: March 4, 2009
Creator: Crooks, Gavin E
Partner: UNT Libraries Government Documents Department

Fermi Timing and Synchronization System

Description: The Fermi FEL will depend critically on precise timing of its RF, laser and diagnostic subsystems. The timing subsystem to coordinate these functions will need to reliably maintain sub-100fs synchronicity between distant points up to 300m apart in the Fermi facility. The technology to do this is not commercially available, and has not been experimentally demonstrated in a working facility. Therefore, new technology must be developed to meet these needs. Two approaches have been researched by different groups working with the Fermi staff. At MIT, a pulse transmission scheme has been developed for synchronization of RF and laser devices. And at LBL, a CW transmission scheme has been developed for RF and laser synchronization. These respective schemes have advantages and disadvantages that will become better understood in coming years. This document presents the work done by both teams, and suggests a possible system design which integrates them both. The integrated system design provides an example of how choices can be made between the different approaches without significantly changing the basic infrastructure of the system. Overall system issues common to any synchronization scheme are also discussed.
Date: July 19, 2006
Creator: Wilcox, R.; Staples, J.; Doolittle, L.; Byrd, J.; Ratti, A.; Kaertner, F.X. et al.
Partner: UNT Libraries Government Documents Department

Observation of field-induced domain wall propagation in magnetic nanowires by magnetic transmission X-ray microscopy

Description: Magnetic transmission X-ray microscopy (M-TXM) is used to image domain walls in magnetic ring structures formed by a 300 nm wide, 24 nm thick Ni{sub 81}Fe{sub 19} nanowire. Both transverse and vortex type domain walls are observed after application of different field sequences. Domain walls can be observed by comparing images obtained from opposite field sequences, or else domain wall propagation observed by comparing successive images in a particular field sequence. This demonstrates the potential use of M-TXM in developing and understanding planar magnetic nanowire behavior.
Date: December 1, 2007
Creator: Bryan, M. T.; Fry, P. W.; Fischer, P. & Allwood, D. A.
Partner: UNT Libraries Government Documents Department

MOSAIC: a new wavefront metrology

Description: MOSAIC is a new wavefront metrology that enables complete wavefront characterization from print or aerial image based measurements. Here we describe MOSAIC and verify its utility with a model-based proof of principle.
Date: February 2, 2009
Creator: Anderson, Christopher & Naulleau, Patrick
Partner: UNT Libraries Government Documents Department