Search Results

open access

Adaptive dimension reduction for clustering high dimensional data

Description: It is well-known that for high dimensional data clustering, standard algorithms such as EM and the K-means are often trapped in local minimum. many initialization methods were proposed to tackle this problem, but with only limited success. In this paper they propose a new approach to resolve this problem by repeated dimension reductions such that K-means or EM are performed only in very low dimensions. Cluster membership is utilized as a bridge between the reduced dimensional sub-space and the original space, providing flexibility and ease of implementation. Clustering analysis performed on highly overlapped Gaussians, DNA gene expression profiles and internet newsgroups demonstrate the effectiveness of the proposed algorithm.
Date: October 1, 2002
Creator: Ding, Chris; He, Xiaofeng; Zha, Hongyuan & Simon, Horst
Partner: UNT Libraries Government Documents Department
open access

ADVANCED GASIFICATION-BASED FUEL CONVERSION AND ELECTRIC ENERGY PRODUCTION SYSTEM

Description: Boise Paper Solutions and the Gas Technology Institute (GTI) are cooperating to develop, demonstrate and place in continuous operation an advanced biomass gasification-based power generation system suitable for near-term commercial deployment in the Forest Products Industry. The system will be used in conjunction with, rather than in place of, existing wood waste fired boilers and flue gas cleanup systems. The novel system will include three advanced technological components based on GTI's RENUGAS{reg_sign} and three-stage stoker combustion technologies, and a gas turbine-based power generation concept developed in DOE's High Performance Power System (HIPPS) program. The system has, as its objective, to avoid the major hurdles of high-pressure gasification, i.e., high-pressure fuel feeding and ash removal, and hot gas cleaning that are typical for conventional IGCC power generation. It aims to also minimize capital intensity and technology risks. The system is intended to meet the immediate needs of the forest products industry for highly efficient and environmentally friendly electricity and steam generation systems utilizing existing wood waste as fuel resources. The overall objective of this project is to demonstrate the commercial applicability of an advanced biomass gasification-based power generation system at Boise Paper Solutions' pulp and paper mill located at DeRidder, Louisiana.
Date: October 1, 2002
Creator: Rabovitser, Joseph & Bryan, Bruce
Partner: UNT Libraries Government Documents Department
open access

Advanced Stripper Gas Produced Water Remediation, Quarterly Technical Report: July-September 2002

Description: Natural gas and oil production from stripper wells also produces water contaminated with hydrocarbons, and in most locations, salts and trace elements. The hydrocarbons are not generally present in concentrations that allow the operator to economically recover these liquids. Produced liquids, (Stripper Gas Water) which are predominantly water, present the operator with two options; purify the water to acceptable levels of contaminates, or pay for the disposal of the water. The project scope involves testing SynCoal as a sorbent to reduce the levels of contamination in stripper gas well produced water to a level that the water can be put to a productive use. Produced water is to be filtered with SynCoal, a processed sub-bituminous coal. It is expected that the surface area of and in the SynCoal would sorb the hydrocarbons and other contaminates and the effluent would be usable for agricultural purposes. Test plan anticipates using two well locations described as being disparate in the level and type of contaminates present. The loading capacity and the rate of loading for the sorbent should be quantified in field testing situations which include unregulated and widely varying liquid flow rates. This will require significant flexibility in the initial stages of the investigation. The scope of work outlined below serves as the guidelines for the testing of SynCoal carbon product as a sorbent to remove hydrocarbons and other contaminants from the produced waters of natural gas wells. A maximum ratio of 1 lb carbon to 100 lbs water treated is the initial basis for economic design. While the levels of contaminants directly impact this ratio, the ultimate economics will be dictated by the filter servicing requirements. This experimental program is intended to identify those treatment parameters that yield the best technological practice for a given set of operating conditions. The goal …
Date: October 2002
Creator: Bonner, Harry & Malmquist, Roger
Partner: UNT Libraries Government Documents Department
open access

Advanced Tokamak Operation Using the DIII-D Plasma Control System

Description: A271 ADVANCED TOKAMAK OPERATION USING THE DIII-D PLASMA CONTROL SYSTEM. The principal focus of experimental operations in the DIII-D tokamak is the advanced tokamak (AT) regime to achieve, which requires highly integrated and flexible plasma control. In a high performance advanced tokamak, accurate regulation of the plasma boundary, internal profiles, pumping, fueling, and heating must be well coordinated with MHD control action to stabilize such instabilities as tearing modes and resistive wall modes. Sophisticated monitors of the operational regime must provide detection of off-normal conditions and trigger appropriate safety responses with acceptable levels of reliability. Many of these capabilities are presently implemented in the DIII-D plasma control system (PCS), and are now in frequent or routine operational use. The present work describes recent development, implementation, and operational experience with AT regime control elements for equilibrium control, MHD suppression, and off-normal event detection and response.
Date: October 1, 2002
Creator: Humphreys, D. A.; Ferron, J. R.; Garofalo, A. M.; Hyatt, A. W.; Jernigan, T. C.; Johnson, R. D. et al.
Partner: UNT Libraries Government Documents Department
open access

ALEGRA: User Input and Physics Descriptions Version 4.2

Description: ALEGRA is an arbitrary Lagrangian-Eulerian finite element code that emphasizes large distortion and shock propagation. This document describes the user input language for the code.
Date: October 1, 2002
Creator: BOUCHERON, EDWARD A.; BROWN, KEVIN H.; BUDGE, KENT G.; BURNS, SHAWN P.; CARROLL, DANIEL E.; CARROLL, SUSAN et al.
Partner: UNT Libraries Government Documents Department
open access

Annual Technical Status Report of the Regulatory Assistance Project: September 2000--September 2001

Description: This report summarizes the work in 2001 by the Regulatory Assistance Project (RAP), under contract to the National Renewable Energy Laboratory. This work focused on identifying and removing the regulatory and institutional barriers that keep the full economic value of distributed resources from being realized. The following five reports present the work details: (1) Accommodating Distributed Resources in Wholesale Markets, NREL/SR-560-32497; (2) Distributed Resource Distribution Credit Pilot Programs - Revealing the Value to Consumers and Vendors, NREL/SR-560-32499; (3) Distributed Resources and Electric System Reliability, NREL/SR-560-32498; (4) Distribution System Cost Methodologies for Distributed Generation, NREL/SR-560-32500; (5) Distribution System Cost Methodologies for Distributed Generation Appendices, NREL/SR. Visit www.eren.doe.gov/distributedpower for more information about RAP contract activity to establish environmental output air emissions standards for small-scale electricity generation (to be published as a future NREL subcontract report).
Date: October 1, 2002
Partner: UNT Libraries Government Documents Department
open access

Apollo(R) Thin Film Process Development: Final Technical Report, April 1998 - April 2002

Description: BP Solar first started investigative work on CdTe photovoltaics in 1986. The module product name chosen for the CdTe devices is Apollo. The deposition method chosen was electrochemical deposition due to its simplicity and good control of stoichiometric composition. The window layer used is CdS, produced from a chemical-bath deposition. Initial work focused on increasing photovoltaic cell size from a few mm2 to 900 cm2. At BP Solar's Fairfield plant, work is focused on increasing semiconductor deposition to 1 m2. The primary objective of this subcontract is to establish the conditions required for the efficient plating of CdS/CdTe on large-area, transparent conducting tin-oxide-coated glass superstrate. The initial phase concentrates on superstrate sizes up to 0.55 m2. Later phases will include work on 0.94 m2 superstrates. The tasks in this subcontract have been split into four main categories: (1) CdS and CdTe film studies; (2) Enhanced laser processing; (3) Outdoor testing program for the Apollo module; and (4) Production waste abatement and closed loop study.
Date: October 1, 2002
Creator: Cunningham, D. W.
Partner: UNT Libraries Government Documents Department
open access

An Approach to Wireless Communications at Sandia National Laboratories

Description: Wireless communication plays an increasing role in military, industrial, public safety, and academic computer networks. Although in general, radio transmitters are not currently permitted in secured areas at Sandia, wireless communications would open new opportunities, allowing mobile and pervasive user access. Without wireless communications, we must live in a ''non-mainstream'' world of fixed, wired networks, where it becomes ever more difficult to attract and retain the best professionals. This report provides a review of the current state of wireless communications, which direction wireless technology is heading, and where wireless technology could be employed at Sandia. A list of recommendations on harnessing the power of wireless communications is provided to aid in building a state-of-the-art communication environment for the 21st century at Sandia.
Date: October 1, 2002
Creator: WITZKE, EDWARD L.
Partner: UNT Libraries Government Documents Department
open access

Appropriations for FY2003: Commerce, Justice, and State, the Judiciary, and Related Agencies

Description: Appropriations are one part of a complex federal budget process that includes budget resolutions, appropriations (regular, supplemental, and continuing) bills, rescissions, and budget reconciliation bills. This report is a guide to one of the 13 regular appropriations bills that Congress passes each year. It is designed to supplement information provided by the House and Senate Commerce, Justice, State Appropriations Subcommittees.
Date: October 1, 2002
Creator: Epstein, Susan B.
Partner: UNT Libraries Government Documents Department
open access

Assessing the Reliability of Computer-Processed Data (Superseded by GAO-09-680G)

Description: Guidance issued by the General Accounting Office with an abstract that begins "This publication has been superseded by GAO-09-680G, Assessing the Reliability of Computer-Processed Data, July 2009. GAO published a guide to assist its auditing staff in ensuring the reliability of computer-based data. The guidance provides a flexible, risk-based framework for data reliability assessments that can be geared to the specific circumstances of each engagement. The framework is built on (1) making use of all existing information about the data; (2) performing at least a minimal level of data testing; (3) doing only the amount of work necessary to determine whether the data are reliable enough for GAO's purposes; (4) maximizing professional judgment; and (5) bringing the appropriate people, including management, to the table at key decision points."
Date: October 1, 2002
Creator: United States. General Accounting Office.
Partner: UNT Libraries Government Documents Department
open access

Associations of Indoor Carbon Dioxide Concentrations, VOCS, Environmental Susceptibilities With Mucous Membrane and Lower Respiratory Sick Building Syndrome Symptoms in the Base Study: Analyses of the 100 Building Dataset

Description: Using the 100 office-building Building Assessment Survey and Evaluation (BASE) Study dataset, we performed multivariate logistic regression analyses to quantify the associations between indoor minus outdoor CO{sub 2} (dCO{sub 2}) concentrations and mucous membrane (MM) and lower respiratory system (Lresp) Sick Building Syndrome (SBS) symptoms, adjusting for age, sex, smoking status, presence of carpet in workspace, thermal exposure, relative humidity, and a marker for entrained automobile exhaust. Using principal components analysis we identified a number of possible sources of 73 measured volatile organic compounds in the office buildings, and assessed the impact of these VOCs on the probability of presenting the SBS symptoms. Additionally we included analysis adjusting for the risks for predisposition of having SBS symptoms associated with the allergic, asthmatic, and environmentally sensitive subpopulations within the office buildings. Adjusted odds ratios (ORs) for statistically significant, dose-dependant associations (p<0.05) for dry eyes, sore throat, nose/sinus congestion, and wheeze symptoms with 100-ppm increases in dCO{sub 2} ranged from 1.1 to 1.2. These results suggest that increases in the ventilation rates per person among typical office buildings will, on average significantly reduce the prevalence of several SBS symptoms, up to 80%, even when these buildings meet the existing ASHRAE ventilation standards for office buildings. VOC sources were observed to play an role in direct association with mucous membrane and lower respiratory irritation, and possibly to be indirectly involved in indoor chemical reactions with ozone that produce irritating compounds associated with SBS symptoms. O-xylene, possibly emitted from furniture coatings was associated with shortness of breath (OR at the maximum concentration = 8, p < 0.05). The environmental sensitivities of a large subset of the office building population add to the overall risk of SBS symptoms (ORs ranging from 2 to above 11) within the buildings.
Date: October 1, 2002
Creator: Apte, M. G. & Erdmann, C. A.
Partner: UNT Libraries Government Documents Department
open access

ATR WG-MOX Fuel Pellet Burnup Measurement by Monte Carlo - Mass Spectrometric Method

Description: This paper presents a new method for calculating the burnup of nuclear reactor fuel, the MCWO-MS method, and describes its application to an experiment currently in progress to assess the suitability for use in light-water reactors of Mixed-OXide (MOX) fuel that contains plutonium derived from excess nuclear weapons material. To demonstrate that the available experience base with Reactor-Grade Mixed uranium-plutonium OXide (RGMOX) can be applied to Weapons-Grade (WG)-MOX in light water reactors, and to support potential licensing of MOX fuel made from weapons-grade plutonium and depleted uranium for use in United States reactors, an experiment containing WG-MOX fuel is being irradiated in the Advanced Test Reactor (ATR) at the Idaho National Engineering and Environmental Laboratory. Fuel burnup is an important parameter needed for fuel performance evaluation. For the irradiated MOX fuel’s Post-Irradiation Examination, the 148Nd method is used to measure the burnup. The fission product 148Nd is an ideal burnup indicator, when appropriate correction factors are applied. In the ATR test environment, the spectrum-dependent and burnup-dependent correction factors (see Section 5 for detailed discussion) can be substantial in high fuel burnup. The validated Monte Carlo depletion tool (MCWO) used in this study can provide a burnup-dependent correction factor for the reactor parameters, such as capture-to-fission ratios, isotopic concentrations and compositions, fission power, and spectrum in a straightforward fashion. Furthermore, the correlation curve generated by MCWO can be coupled with the 239Pu/Pu ratio measured by a Mass Spectrometer (in the new MCWO-MS method) to obtain a best-estimate MOX fuel burnup. A Monte Carlo - MCWO method can eliminate the generation of few-group cross sections. The MCWO depletion tool can analyze the detailed spatial and spectral self-shielding effects in UO2, WG-MOX, and reactor-grade mixed oxide (RG-MOX) fuel pins. The MCWO-MS tool only needs the MS-measured 239Pu/Pu ratio, without the measured isotope 148Nd …
Date: October 1, 2002
Creator: Chang, Gray Sen I
Partner: UNT Libraries Government Documents Department
open access

Best Estimate Radiation Flux Value-Added Procedure: Algorithm Operational Details and Explanations

Description: This document describes some specifics of the algorithm for best estimate evaluation of radiation fluxes at Southern Great Plains (SGP) Central Facility (CF). It uses the data available from the three co-located surface radiometer platforms at the SGP CF to automatically determine the best estimate of the irradiance measurements available. The Best Estimate Flux (BEFlux) value-added procedure (VAP) was previously named Best Estimate ShortWave (BESW) VAP, which included all of the broadband and spectral shortwave (SW) measurements for the SGP CF. In BESW, multiple measurements of the same quantities were handled simply by designating one as the primary measurement and using all others to merely fill in any gaps. Thus, this “BESW” is better termed “most continuous,” since no additional quality assessment was applied. We modified the algorithm in BESW to use the average of the closest two measurements as the best estimate when possible, if these measurements pass all quality assessment criteria. Furthermore, we included longwave (LW) fields in the best estimate evaluation to include all major components of the surface radiative energy budget, and renamed the VAP to Best Estimate Flux (BEFLUX1LONG).
Date: October 1, 2002
Creator: Shi, Y. & Long, C. N.
Partner: UNT Libraries Government Documents Department
open access

Better Understanding Public Perceptions of Risk: Possible Implications for Long-term Environmental Stewardship and Hazardous Waste Management

Description: In the treatment, disposition, and long-term stewardship (e.g., storage) of hazardous waste forms, questions that are of particular concern are: • What is technically feasible and safe, • What is economically affordable, • What is legally mandated and allowable, and • What is publicly acceptable? Although DOE is exerting considerable effort in making sound science-based decisions that are economical and meet legal requirements, it may be lapse in not gaining a better understanding of how public perceptions are formed. This observation appears especially true in regards to the perceived long-term integrity and safety of various proposed hazardous waste storage options. The purpose of this research was to investigate how differences in how hazardous materials are configured and how those configurations are presented affect peoples’ perceptions of how safe they are. Specifically, we designed a preliminary experiment that assessed the public’s perception of risk for various storage configurations of hazardous materials. We included into the design factors to measure participants’ deliberative and spontaneous response to the perceived safety (or danger) posed by different hazardous materials storage configurations. The critical objectives of the proposed effort were to identify specific characteristics of hazardous materials storage configuration and to identify possible differences in deliberative and spontaneous processing of those specific characteristics. Identification of these objectives is critical in understanding what does and does not constitute an acceptable approach to hazardous waste treatment, disposition, and long-term storage. FY01 TECHNICAL OBJECTIVES • Develop an experimental process for collecting perceptions regarding the perceived safety and long-term integrity of hazardous waste storage systems. • Develop a computer-based, reusable collection instrument “system” with associated graphical images. • Validate the applicability and value of the developed methodology by conducting an on-site experiment. • Submit results for publication in an applicable, peer-reviewed scientific journal. • Propose follow-on work and funding requests …
Date: October 1, 2002
Creator: Joe, Jeffrey Clark & Harbour, Gerald Lee
Partner: UNT Libraries Government Documents Department
open access

Blade Manufacturing Improvement Project: Final Report

Description: The Blade Manufacturing Improvement Project explores new, unique and improved materials integrated with innovative manufacturing techniques that promise substantial economic enhancements for the fabrication of wind turbine blades. The primary objectives promote the development of advanced wind turbine blade manufacturing in ways that lower blade costs, cut rotor weight, reduce turbine maintenance costs, improve overall turbine quality and increase ongoing production reliability. Foam Matrix (FMI) has developed a wind turbine blade with an engineered foam core, incorporating advanced composite materials and using Resin Transfer Molding (RTM) processes to form a monolithic blade structure incorporating a single molding tool. Patented techniques are employed to increase blade load bearing capability and insure the uniform quality of the manufactured blade. In production quantities, FMI manufacturing innovations may return a sizable per blade cost reduction when compared to the cost of producing comparable blades with conventional methods.
Date: October 1, 2002
Creator: SHERWOOD, KENT
Partner: UNT Libraries Government Documents Department
open access

Breakthrough in precision (0.3 percent) of neutron activation analyses applied to provenience studies of obsidian

Description: A gamma ray spectrometer at LBNL (the Luis W. Alvarez Iridium Coincidence Spectrometer), that was specifically designed for high sensitivity measurements of iridium abundances, has been significantly modified in order to provide precisions of measurement in neutron activation analysis of obsidian significantly better than previously obtained (about 1%). Repeated measurements on a single sample of obsidian from a deposit near Chivay, Arequipa, Peru, showed a precision (average coefficient of variation) of 0.19% for the 6 best-measured elements, the value anticipated from the known random errors of measurement. In measurement of samples made from 7 different obsidian nodules from two locations near Chivay, a group of 5 had a spread of 0.30% for the 6 elements measured with counting statistics of better than 0.3% (and 1.8% for the remaining 6 elements). The data suggest there are source inhomogeneity and/or sample preparation contamination errors totaling 0.24 {+-} .05% for the 6 best measured elements. A sixth obsidian sample could be distinguished from the main group because it differed by +0.8% for most elements, and the last sample could be easily distinguished because several elements differed by more than 1%. The precision of measurements now being developed may provide a significantly more precise determination of the provenience of obsidian artifacts than has been heretofore possible. Also the techniques of measurement developed for obsidian will provide even better precisions with pottery, as many elements are more abundant in pottery than in obsidian.
Date: October 1, 2002
Creator: Asaro, Frank; Stross, Fred H. & Burger, Richard L.
Partner: UNT Libraries Government Documents Department
open access

Building America Field Project: Results for the Consortium for Advanced Residential Buildings (CARB), January to October 2001

Description: This report describes the various projects by the Consortium for Advanced Residential Buildings (CARB) that were active during the first 10 months of 2001, summarizing results, benefits, lessons learned, and future plans. The second part of this report describes technical matters, summarizing innovative technologies, systems engineering and results, and industry team member contributions.
Date: October 1, 2002
Partner: UNT Libraries Government Documents Department
Back to Top of Screen