Accounting for Global Climate Model Projection Uncertainty in Modern Statistical Downscaling (open access)

Accounting for Global Climate Model Projection Uncertainty in Modern Statistical Downscaling

Future climate change has emerged as a national and a global security threat. To carry out the needed adaptation and mitigation steps, a quantification of the expected level of climate change is needed, both at the global and the regional scale; in the end, the impact of climate change is felt at the local/regional level. An important part of such climate change assessment is uncertainty quantification. Decision and policy makers are not only interested in 'best guesses' of expected climate change, but rather probabilistic quantification (e.g., Rougier, 2007). For example, consider the following question: What is the probability that the average summer temperature will increase by at least 4 C in region R if global CO{sub 2} emission increases by P% from current levels by time T? It is a simple question, but one that remains very difficult to answer. It is answering these kind of questions that is the focus of this effort. The uncertainty associated with future climate change can be attributed to three major factors: (1) Uncertainty about future emission of green house gasses (GHG). (2) Given a future GHG emission scenario, what is its impact on the global climate? (3) Given a particular evolution of the …
Date: March 17, 2010
Creator: Johannesson, G
Object Type: Report
System: The UNT Digital Library
CO2 MONITORING FOR DEMAND CONTROLLED VENTILATION IN COMMERCIAL BUILDINGS (open access)

CO2 MONITORING FOR DEMAND CONTROLLED VENTILATION IN COMMERCIAL BUILDINGS

Carbon dioxide (CO{sub 2}) sensors are often deployed in commercial buildings to obtain CO{sub 2} data that are used, in a process called demand-controlled ventilation, to automatically modulate rates of outdoor air ventilation. The objective is to keep ventilation rates at or above design specifications and code requirements and also to save energy by avoiding excessive ventilation rates. Demand controlled ventilation is most often used in spaces with highly variable and sometime dense occupancy. Reasonably accurate CO{sub 2} measurements are needed for successful demand controlled ventilation; however, prior research has suggested substantial measurement errors. Accordingly, this study evaluated: (a) the accuracy of 208 CO{sub 2} single-location sensors located in 34 commercial buildings, (b) the accuracy of four multi-location CO{sub 2} measurement systems that utilize tubing, valves, and pumps to measure at multiple locations with single CO{sub 2} sensors, and (c) the spatial variability of CO{sub 2} concentrations within meeting rooms. The field studies of the accuracy of single-location CO{sub 2} sensors included multi-concentration calibration checks of 90 sensors in which sensor accuracy was checked at multiple CO{sub 2} concentrations using primary standard calibration gases. From these evaluations, average errors were small, -26 ppm and -9 ppm at 760 and 1010 …
Date: March 17, 2010
Creator: Fisk, William J.; Sullivan, Douglas P.; Faulkner, David & Eliseeva, Ekaterina
Object Type: Report
System: The UNT Digital Library
A Comparison of Three Voting Methods for Bagging with the MLEM2 Algorithm (open access)

A Comparison of Three Voting Methods for Bagging with the MLEM2 Algorithm

This paper presents results of experiments on some data sets using bagging on the MLEM2 rule induction algorithm. Three different methods of ensemble voting, based on support (a non-democratic voting in which ensembles vote with their strengths), strength only (an ensemble with the largest strength decides to which concept a case belongs) and democratic voting (each ensemble has at most one vote) were used. Our conclusions are that though in most cases democratic voting was the best, it is not significantly better than voting based on support. The strength voting was the worst voting method.
Date: March 17, 2010
Creator: Cohagan, Clinton; Grzymala-Busse, Jerzy W. & Hippe, Zdzislaw S.
Object Type: Article
System: The UNT Digital Library
Final Report for "Verification and Validation of Radiation Hydrodynamics for Astrophysical Applications" (open access)

Final Report for "Verification and Validation of Radiation Hydrodynamics for Astrophysical Applications"

The motivation for this work is to gain experience in the methodology of verification and validation (V&V) of astrophysical radiation hydrodynamics codes. In the first period of this work, we focused on building the infrastructure to test a single astrophysical application code, Castro, developed in collaboration between Lawrence Livermore National Laboratory (LLNL) and Lawrence Berkeley Laboratory (LBL). We delivered several hydrodynamic test problems, in the form of coded initial conditions and documentation for verification, routines to perform data analysis, and a generalized regression test suite to allow for continued automated testing. Astrophysical simulation codes aim to model phenomena that elude direct experimentation. Our only direct information about these systems comes from what we observe, and may be transient. Simulation can help further our understanding by allowing virtual experimentation of these systems. However, to have confidence in our simulations requires us to have confidence in the tools we use. Verification and Validation is a process by which we work to build confidence that a simulation code is accurately representing reality. V&V is a multistep process, and is never really complete. Once a single test problem is working as desired (i.e. that problem is verified), one wants to ensure that subsequent code …
Date: March 17, 2010
Creator: Zingale, M & Howell, L H
Object Type: Report
System: The UNT Digital Library
Northwest Open Automated Demand Response Technology Demonstration Project (open access)

Northwest Open Automated Demand Response Technology Demonstration Project

The Lawrence Berkeley National Laboratory (LBNL) Demand Response Research Center (DRRC) demonstrated and evaluated open automated demand response (OpenADR) communication infrastructure to reduce winter morning and summer afternoon peak electricity demand in commercial buildings the Seattle area. LBNL performed this demonstration for the Bonneville Power Administration (BPA) in the Seattle City Light (SCL) service territory at five sites: Seattle Municipal Tower, Seattle University, McKinstry, and two Target stores. This report describes the process and results of the demonstration. OpenADR is an information exchange model that uses a client-server architecture to automate demand-response (DR) programs. These field tests evaluated the feasibility of deploying fully automated DR during both winter and summer peak periods. DR savings were evaluated for several building systems and control strategies. This project studied DR during hot summer afternoons and cold winter mornings, both periods when electricity demand is typically high. This is the DRRC project team's first experience using automation for year-round DR resources and evaluating the flexibility of commercial buildings end-use loads to participate in DR in dual-peaking climates. The lessons learned contribute to understanding end-use loads that are suitable for dispatch at different times of the year. The project was funded by BPA and SCL. …
Date: March 17, 2010
Creator: Kiliccote, Sila; Piette, Mary Ann & Dudley, Junqiao
Object Type: Report
System: The UNT Digital Library
PACE and the Federal Housing Finance Agency (FHFA) (open access)

PACE and the Federal Housing Finance Agency (FHFA)

The FHFA regulates Fannie Mae, Freddie Mac, and the 12 Federal Home Loan Banks (the government-sponsored enterprises - GSEs). On June 18, 2009, James B. Lockhart III, then Director of FHFA, released a letter expressing concern about the negative impact of energy loan tax assessment programs (ELTAPs) - also known as Property Assessed Clean Energy (PACE) programs - on both the housing finance system and homeowner program participants. Subsequently, a number of PACE proponents responded to the concerns laid out in the FHFA letter. In early Fall 2009, word circulated that FHFA was planning to follow its June letter with guidance to other agencies, possibly including Fannie Mae and Freddie Mac, discouraging them from buying loans on properties subject to PACE-type assessment liens. This triggered a second round of stakeholder letters, several of which were addressed to President Obama. On October 18, 2009, the White House, in what some believe was an attempt to obviate the need for FHFA guidance, released a Policy Framework for PACE Financing Programs that outlined best practices guidance for homeowner and lender protection. As of February 2010, FHFA and the GSEs have agreed to monitor PACE programs and work with stakeholders and the Administration to …
Date: March 17, 2010
Creator: Zimring, Mark & Fuller, Merrian
Object Type: Report
System: The UNT Digital Library
Proceedings of RIKEN BNL Research Center Workshop: Progress in High-pT Physics at RHIC (open access)

Proceedings of RIKEN BNL Research Center Workshop: Progress in High-pT Physics at RHIC

This volume archives the presentations at the RIKEN BNL Research Center workshop 'Progress in High-PT Physics at RHIC', held at BNL in March 2010. Much has been learned from high-p{sub T} physics after 10 years of RHIC operations for heavy-ion collisions, polarized proton collisions and d+Au collisions. The workshop focused on recent progress in these areas by both theory and experiment. The first morning saw review talks on the theory of RHIC high-p{sub T} physics by G. Sterman and J. Soffer, and on the experimental results by M. Tannenbaum. One of the most exciting recent results from the RHIC spin program is the first observation of W bosons and their associated single-spin asymmetry. The new preliminary data were reported on the first day of our workshop, along with a theoretical perspective. There also were detailed discussions on the global analysis of polarized parton distributions, including the knowledge on gluon polarization and the impact of the W-data. The main topic of the second workshop day were single-transverse spin asymmetries and their analysis in terms of transverse-momentum dependent parton distributions. There is currently much interest in a future Drell-Yan program at RHIC, thanks to the exciting physics opportunities this would offer. This …
Date: March 17, 2010
Creator: Bazilevsky, A.; Bland, L. & Vogelsang, W.
Object Type: Report
System: The UNT Digital Library
X-ray source brightness comparison: Rigaku rotating anode source vs. Kevex microfocus tube (open access)

X-ray source brightness comparison: Rigaku rotating anode source vs. Kevex microfocus tube

In 2007, we began to explore alternative x-ray sources for application to refraction-enhanced (phase contrast) x-ray radiography of cryogenic NIF ignition capsules containing frozen deuterium-tritium (D-T) ice layers. These radiographs are currently obtained using Kevex microfocus tubes as backlights, and for these sources the x-ray source size is approximately 5 {micro}m. As part of this exploration, we obtained refraction-enhanced radiographs of empty plastic capsules using the Janus laser facility at LLNL, demonstrating that even large ({approx} 100 {micro}m) sources can be utilized in refraction-enhanced radiography provided the source/sample distance is sufficiently large, and provided the final x-ray detector has sufficient spatial resolution. Essentially, in the current geometry, we rely on a small source to provide spatial resolution and on the source/sample distance to provide refraction contrast, but an equally useful alternative geometry is to use a large source and rely on fine detector spatial resolution to provide spatial resolution and on the sample/detector distance to provide refraction contrast.
Date: March 17, 2010
Creator: Koch, J A; Dewald, E & Kozioziemski, B
Object Type: Report
System: The UNT Digital Library