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At least 1,243 records · Page 69

Implementing efficient data compression and encryption in a persistent key-value store for HPC

Recently, persistent data structures, like key-value stores (KVSs), which are stored in a high-performance computing (HPC) system’s nonvolatile memory, provide an attractive solution for a number of emerging challenges like limited I/O performance. Data compression and encryption are two well-known techniques for improving several properties of such data-oriented systems. This article investigates how to efficiently integrate data compression and encryption into persistent KVSs for HPC with the ultimate goal of hiding their costs and complexity in terms of performance and ease of use. Our compression technique exploits deep memory hierarchy in an HPC system to achieve both storage reduction and performance improvement. Our encryption technique provides a practical level of security and enables sharing of sensitive data securely in complex scientific workflows with nearly imperceptible cost. We implement the proposed techniques on top of a distributed embedded KVS to evaluate the benefits and costs of incorporating these capabilities along different points in the dataflow path, illustrating differences in effective bandwidth, latency, and additional computational expense on Swiss National Supercomputing Centre’s Grand Tavé and National Energy Research Scientific Computing Center’s Cori.

97 MATHEMATICS AND COMPUTING↗

An Effective Earned Value Management System (EVMS) is a Team Sport

We present a novel framework to assess 27 earned value management system (EVMS) environment factors and investigate their impact on project performance. A study of the EVMS literature, a survey of practitioners, and focus group meetings with 36 EVMS industry and government experts, supported the development of the framework. Focus groups involving 80 practitioners refined and tested it. We analyzed performance data from 35 completed projects/programs representing over US$21.8 billion in total cost; a project demonstrating a positive environment could save up to 25% in cost versus baseline. Practitioners can develop an effective EVMS environment by following the provided guidance.

Aramali, Vartenie↗

Technoeconomic evaluation of recent process improvements in production of sugar and high-value lignin co-products via two-stage Cu-catalyzed alkaline-oxidative pretreatment

Abstract Background A lignocellulose-to-biofuel biorefinery process that enables multiple product streams is recognized as a promising strategy to improve the economics of this biorefinery and to accelerate technology commercialization. We recently identified an innovative pretreatment technology that enables of the production of sugars at high yields while simultaneously generating a high-quality lignin stream that has been demonstrated as both a promising renewable polyol replacement for polyurethane applications and is highly susceptible to depolymerization into monomers. This technology comprises a two-stage pretreatment approach that includes an alkaline pre-extraction followed by a metal-catalyzed alkaline-oxidative pretreatment. Our recent work demonstrated that H 2 O 2 and O 2 act synergistically as co-oxidants during the alkaline-oxidative pretreatment and could significantly reduce the pretreatment chemical input while maintaining high sugar yields (~ 95% glucose and ~ 100% xylose of initial sugar composition), high lignin yields (~ 75% of initial lignin), and improvements in lignin usage. Results This study considers the economic impact of these advances and provides strategies that could lead to additional economic improvements for future commercialization. The results of the technoeconomic analysis (TEA) demonstrated that adding O 2 as a co-oxidant at 50 psig for the alkaline-oxidative pretreatment and reducing the raw material input reduced the minimum fuel selling price from $1.08/L to $0.85/L, assuming recoverable lignin is used as a polyol replacement. If additional lignin can be recovered and sold as more valuable monomers, the minimum fuel selling price (MFSP) can be further reduced to $0.73/L. Conclusions The present work demonstrated that high sugar and lignin yields combined with low raw material inputs and increasing the value of lignin could greatly increase the economic viability of a poplar-based biorefinery. Continued research on integrating sugar production with lignin valorization is thus warranted to confirm this economic potential as the technology matures.

09 BIOMASS FUELS↗

The Prognostic Value of a Pathologic Complete Response After Neoadjuvant Therapy for Digestive Cancer: Systematic Review and Meta-Analysis of 21 Studies

Background: Neoadjuvant therapy (NAT) before radical excision has become the preferred initial option for locally advanced digestive cancers such as esophageal cancer (EC), esophagogastric junction adenocarcinoma (EGJAC), gastric adenocarcinoma (GAC), rectal cancer (RC), and pancreatic cancer (PC). Although some patients reportedly achieve a pathologic complete response (pCR) after neoadjuvant therapy, the published data are inconsistent regarding whether pCR yields a survival benefit. The current meta-analysis was performed to assess the potential prognostic value of pCR after preoperative therapy for patients with digestive cancers. Methods: An extensive electronic search in PubMed, Web of Science, and the Cochrane Library was performed for relevant articles, from which data relative to independent correlations of pCR with overall survival (OS) and disease-free survival (DFS) were extracted for analysis. A random-effects model was used to calculate the pooled hazard ratios (HRs) with their corresponding 95% confidence intervals (CIs). Results: The study identified 6780 patients who met the inclusion and exclusion criteria. The results showed that pCR was significantly correlated with better OS (HR, 0.50; 95% CI, 0.43–0.58; P < 0.001) and DFS (HR, 0.49; 95% CI, 0.40–0.60; P < 0.001) for the digestive cancer patients who achieved pCR than for those who did not achieve pCR. Subgroup analysis showed that the correlation of pCR with OS was significant in EC (HR, 0.57; 95% CI, 0.47–0.69; P < 0.001), EGJAC/GAC (HR, 0.38; 95% CI, 0.17–0.86; P = 0.02), RC (HR, 0.48; 95% CI, 0.28–0.81; P = 0.006), and PC (HR, 0.41; 95% CI, 0.17–0.97; P = 0.04). In addition, the survival benefit for pCR patients was of similar magnitude, irrespective of the type of study, type of NAT, or ethnicity. Conclusions: A pCR is correlated with favorable survival outcomes compared with a non-pCR for digestive cancer patients after NAT.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Ethanol and High-Value Terpene Co-Production from Lignocellulosic Biomass of Cymbopogon flexuosus and Cymbopogon martinii

Cymbopogon flexuosus, lemongrass, and C. martinii, palmarosa, are perennial grasses grown to produce essential oils for the fragrance industry. The objectives of this study were (1) to evaluate biomass and oil yields as a function of nitrogen and sulfur fertilization, and (2) to characterize their utility for lignocellulosic ethanol compared to Panicum virgatum (switchgrass). Mean biomass yields were 12.83 Mg lemongrass ha -1 and 15.11 Mg palmarosa ha -1 during the second harvest year resulting in theoretical biofuel yields of 2541 and 2569 L ethanol ha -1 respectively compared to reported 1749–3691 L ethanol ha -1 for switchgrass. Pretreated lemongrass yielded 198 mL ethanol (g biomass) -1 and pretreated palmarosa yielded 170 mL ethanol (g biomass) -1 . Additionally, lemongrass yielded 85.7 kg essential oil ha-1 and palmarosa yielded 67.0 kg ha -1 with an estimated value of USD $857 and $1005 ha -1 . These data suggest that dual-use crops such as lemongrass and palmarosa may increase the economic viability of lignocellulosic biofuels.

09 BIOMASS FUELS↗

The Microbase Value-Added Product: A Baseline Retrieval of Cloud Microphysical Properties

This report describes the Atmospheric Radiation Measurement (ARM) Climate Research Facility baseline cloud microphysical properties (MICROBASE) value-added product (VAP). MICROBASE uses a combination of millimeter-wavelength cloud radar, microwave radiometer, and radiosonde observations to estimate the vertical profiles of the primary microphysical parameters of clouds including the liquid/ice water content and liquid/ice cloud particle effective radius. MICROBASE is a baseline algorithm designed to apply to most conditions and locations using a single set of parameterizations and a simple determination of water phase based on temperature. This document provides the user of this product with guidelines to assist in determining the accuracy of the product under certain conditions. Quality control flags are designed to identify outliers and indicate instances where the retrieval assumptions may not be met. The overall methodology is described in this report through a detailed description of the input variables, algorithms, and output products.

54 ENVIRONMENTAL SCIENCES↗

ARM Climate Research Facility Quarterly Value-Added Product Report January 1–March 30, 2011

The purpose of this report is to provide a concise status update for value-added products (VAP) implemented by the Atmospheric Radiation Measurement Climate Research Facility. The report is divided into the following sections: (1) new VAPs for which development has begun, (2) progress on existing VAPs, and (3) future VAPs that have been recently approved.

54 ENVIRONMENTAL SCIENCES↗

Maximizing the Value of Photovoltaic Installations on Schools in California: Choosing the Best Electricity Rates

Schools in California often have a choice between multiple electricity rate options. For schools with photovoltaic (PV) installations, choosing the right rate is essential to maximize the value of PV generation. The rate option that minimizes a school's electricity expenses often does not remain the most economical choice after the school installs a PV system. The complex interaction between PVgeneration, building load, and rate structure makes determining the best rate a challenging task. This report evaluates 22 rate structures across three of California's largest electric utilities--Pacific Gas and Electric Co. (PG&E), Southern California Edison (SCE), and San Diego Gas and Electric (SDG&E)--in order to identify common rate structure attributes that are favorable to PVinstallations.

14 SOLAR ENERGY↗

Micropulse Lidar Cloud Mask (MPLCMASK) Value-Added Product for the Fast-Switching Polarized Micropulse Lidar Technical Report

Lidar backscattered signal is a useful tool for identifying vertical cloud structure in the atmosphere in optically thin clouds. Cloud boundaries derived from lidar signals are a necessary input for popular ARM data products, such as the Active Remote Sensing of Clouds (ARSCL) product. An operational cloud boundary algorithm (Wang and Sassen 2001) has been implemented for use with the ARM Micropulse Lidar (MPL) systems. In addition to retrieving cloud boundaries above 500 m, the value-added product (VAP) named Micropulse Lidar Cloud Mask (MPLCMASK) applies lidar-specific corrections (i.e., range-square, background, deadtime, and overlap) as described in Campbell et al. (2002) to the measured backscattered lidar. Depolarization ratio is computed using the methodology developed by Flynn et al. (2007) for polarization-capable MPL systems. The cloud boundaries output from MPLCMASK will be the primary lidar cloud mask for input to the ARSCL product and will be applied to all MPL systems, including historical data sets.

54 ENVIRONMENTAL SCIENCES↗

MWRRET Value-Added Product: The Retrieval of Liquid Water Path and Precipitable Water Vapor from Microwave Radiometer (MWR) Data Sets (Revision 2)

This report provides a short description of the Atmospheric Radiation Measurement (ARM) Climate Research Facility microwave radiometer (MWR) Retrieval (MWRRET) value-added product (VAP) algorithm. This algorithm utilizes a complementary physical retrieval method and applies brightness temperature offsets to reduce spurious liquid water path (LWP) bias in clear skies resulting in significantly improved precipitable water vapor (PWV) and LWP retrievals. We present a general overview of the technique, input parameters, output products, and describe data quality checks. A more complete discussion of the theory and results is given in Turner et al. (2007b).

54 ENVIRONMENTAL SCIENCES↗

ARM Climate Research Facility Quarterly Value-Added Product Report Third Quarter: April 01–June 30, 2011

The purpose of this report is to provide a concise status update for value-added products (VAP) implemented by the Atmospheric Radiation Measurement Climate Research Facility. The report is divided into the following sections: (1) new VAPs for which development has begun, (2) progress on existing VAPs, (3) future VAPs that have been recently approved, (4) other work that leads to a VAP, and (5) top requested VAPs from the archive

54 ENVIRONMENTAL SCIENCES↗

Raman Lidar Profiles Best Estimate Value-Added Product Technical Report

The ARM Raman lidars are semi-autonomous ground-based systems that transmit at a wavelength of 355 nm with 300 mJ, ~5 ns pulses, and a pulse repetition frequency of 30Hz. Signals from the various detection channels are processed to produce time- and height-resolved estimates of several geophysical quantities, such as water vapor mixing ratio, relative humidity, aerosol scattering ratio, backscatter, optical depth, extinction, and depolarization ratio. Data processing is currently handled by a suite of six value-added product (VAP) processes. Collectively, these processes are known as the Raman Lidar Profiles VAP (RLPROF). The top-level best-estimate (BE) VAP process was introduced in order to bring together the most relevant information from the intermediate-level VAPs. As such, the BE process represents the final stage in data processing for the Raman lidar. Its principal function is to extract the primary variables from each of the intermediate-level VAPs, perform additional quality control, and combine all of this information into a single output file for the end-user. The focus of this document is to describe the processing performed by the BE VAP process.

54 ENVIRONMENTAL SCIENCES↗

Aerosol Best Estimate (AEROSOLBE) Value-Added Product

The objective of the Aerosol Best Estimate (AEROSOLBE) value-added product (VAP) is to provide vertical profiles of aerosol extinction, single scatter albedo, asymmetry parameter, and Angstroem exponents for the atmospheric column above the Central Facility at the ARM Southern Great Plains (SGP) site. We expect that AEROSOLBE will provide nearly continuous estimates of aerosol optical properties under a range of conditions (clear, broken clouds, overcast clouds, etc.). The primary requirement of this VAP was to provide an aerosol data set as continuous as possible in both time and height for the Broadband Heating Rate Profile (BBHRP) VAP in order to provide a structure for the comprehensive assessment of our ability to model atmospheric radiative transfer for all conditions. Even though BBHRP has been completed, AEROSOLBE results are very valuable for environmental, atmospheric, and climate research.

54 ENVIRONMENTAL SCIENCES↗

Raman Lidar Profiles–Temperature (RLPROFTEMP) Value-Added Product

The purpose of this document is to describe the Raman Lidar Profiles–Temperature (RLPROFTEMP) value-added product (VAP) and the procedures used to derive atmospheric temperature profiles from the raw RL measurements. Sections 2 and 4 describe the input and output variables, respectively. Section 3 discusses the theory behind the measurement and the details of the algorithm, including calibration and overlap correction.

47 OTHER INSTRUMENTATION↗

G-Band Vapor Radiometer Precipitable Water Vapor (GVRPWV) Value-Added Product

The G-Band Vapor Radiometer Precipitable Water Vapor (GVRPWV) value-added product (VAP) computes precipitable water vapor using neural network techniques from data measured by the GVR. The GVR reports time-series measurements of brightness temperatures for four channels located at 183.3 ± 1, 3, 7, and 14 GHz.

54 ENVIRONMENTAL SCIENCES↗

Production of High Value Cellulose from Tobacco

The Kentucky Rural Energy Supply Program was established in 2005 by a federal direct appropriation to benefit the citizens of the Commonwealth by creating a unified statewide consortium to promote renewable energy and energy efficiency in Kentucky. The U.S. Department of Energy's (DOE) Office of Biomass Programs initially funded the consortium in 2005 with a $2 million operational grant. The Kentucky Rural Energy Consortium (KREC) was formed at the outset of the program to advance energy efficiency and comprehensive research on biomass and bioenergy of importance to Kentucky agriculture, rural communities, and related industries. In recognition of the successful efforts of the program, KREC received an additional $1.96 million federal appropriation in 2008 for renewal of the DOE grant. From the beginning, KREC understood the value of providing a statewide forum for the discussion of Kentucky's long term energy needs and economic development potential. The new funding allowed KREC to continue to serve as a clearinghouse and support new research and development and outreach programs for energy efficiency and renewable energy.

Renewable Energy, Energy Efficiency↗