Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “DECISION”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 379 records · Page 21
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

A Decision Support System for Extravehicular Operations Under Significant Communication Latency

Humanity hopes to perform extravehicular activities (EVAs) on the surface of Mars; however, several technical and operational challenges must first be overcome. Foremost among these challenges is managing a significant communication latency between Earth and Mars. Current and historical paradigms of EVA operations have required near-real-time communication between the crewmember(s) and Earth-based mission control. Nextgeneration operational paradigms for supporting deep space exploration will necessitate a distributed decision authority system, including delayed Earth-based mission control, the onplanet extravehicular crewmember(s), and intermediate mission support from intravehicular (IV) crewmember(s) within real-time communication range. This latter group is of particular interest: they must provide operations support without the plentiful resources available to mission control on Earth. Thus, NASA is developing the Personalized EVA Informatics and Decision Support (PersEIDS) software platform. PersEIDS is designed to bolster operator situational awareness and offload operator workload by automatically tracking and projecting consumables usage over an EVA timeline, providing real-time probabilistic safety assessments and recommending alternative EVA timeline(s) when the active timeline is not expected to be completed under consumables limits. The PersEIDS concept of operations, use cases, and models will be presented. A limited version of PersEIDS was demonstrated during a three-day-long study where each day a roughly four-hour-long simulated Martian EVA was performed in virtual reality at the NASA Johnson Space Center. The first day was a control trial without PersEIDS support; the second and third days represented different levels of decision support provided by PersEIDS to the IV crewmember acting as mission control. With PersEIDS support, the IV crewmember was able to manage the mission to completion faster and with more remaining consumables; however, additional testing is required to understand confounding factors, e.g., training bias.

Mars↗
NASA NTRSDate not supplied

PersEIDS: A Biomedical Decision Support System for Extravehicular Operations Under Significant Communication Latency

Humanity hopes to perform extravehicular activities (EVAs) on the surface of Mars; however, several technical and operational challenges must first be overcome. Foremost among these challenges is managing a significant communication latency between Earth and Mars. Current and historical paradigms of EVA operations have required near-real-time communication between the crewmember(s) and Earth-based mission control. Nextgeneration operational paradigms for supporting deep space exploration will necessitate a distributed decision authority system, including delayed Earth-based mission control, the onplanet extravehicular crewmember(s), and intermediate mission support from intravehicular (IV) crewmember(s) within real-time communication range. This latter group is of particular interest: they must provide operations support without the plentiful resources available to mission control on Earth. Thus, NASA is developing the Personalized EVA Informatics and Decision Support (PersEIDS) software platform. PersEIDS is designed to bolster operator situational awareness and offload operator workload by automatically tracking and projecting consumables usage over an EVA timeline, providing real-time probabilistic safety assessments and recommending alternative EVA timeline(s) when the active timeline is not expected to be completed under consumables limits. The PersEIDS concept of operations, use cases, and models will be presented. A limited version of PersEIDS was demonstrated during a three-day-long study where each day a roughly four-hour-long simulated Martian EVA was performed in virtual reality at the NASA Johnson Space Center. The first day was a control trial without PersEIDS support; the second and third days represented different levels of decision support provided by PersEIDS to the IV crewmember acting as mission control. With PersEIDS support, the IV crewmember was able to manage the mission to completion faster and with more remaining consumables; however, additional testing is required to understand confounding factors, e.g., training bias.

Mars↗
DOE OSTI2017

An Introduction to Solar Decision-Making Tools

The National Renewable Energy Laboratory (NREL) offers a variety of models and analysis tools to help decision makers evaluate and make informed decisions about solar projects, policies, and programs. This fact sheet aims to help decision makers determine which NREL tool to use for a given solar project or policy question, depending on its scope.

14 SOLAR ENERGY↗
DOE OSTI2019

Renewable Energy Data, Analysis, and Decisions Viewed through a Case Study in Bangladesh: Preprint

Many developing countries around the world have signaled their intention to transition their energy sectors to rely on cleaner sources of electricity generation for a variety of reasons that may include complying with their Nationally Determined Contributions (in support of the Paris Climate Agreement), increasing energy security, or reducing air pollution. Renewable energy resources are increasingly a cost competitive option for new electricity generation; however, nations must consider renewable energy potential if they wish to increase these technologies in their electricity generation mix. Yet, goal setting, policymaking, grid modeling, and investment decisions that will enable renewable energy development all depend on the existence and quality of renewable energy resource data. This paper aims to summarize the relationship between renewable energy data, analysis, and decision making for developing countries seeking to transition their energy sector and to consider Bangladesh as a case study of a country that has worked with development organizations and the National Renewable Energy Laboratory to develop a national inventory of renewable energy resource data to enable critical decision making.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2019

Renewable Energy Data and Decision Support for Kazakhstan - RE Data Explorer in Action

In 2016, with support from USAID Central Asia and the U.S. Department of State Leadership Compact, and in collaboration with the Government of Kazakhstan and other Central Asian governments, NREL launched the RE Data Explorer for Central Asia, including world-class wind and solar resource data for Kazakhstan and surrounding countries. The RE Data Explorer provides an easy- to-use online platform for users to view, analyze, and download high-quality datasets for informed decision-making. The RE Data Explorer is part of a broader platform called the RE Explorer that provides expertly curated materials and knowledge resources to enable data-driven decisions. This case study documents how the RE Data Explorer was used to support renewable energy decision-making in Kazakhstan.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2017

Decision trees for incorporating the likelihood of excessive hydrologic alteration into hydropower-ecosystem tradeoffs

Detrimental ecological impacts have often been observed or anticipated when changes in streamflow indicators exceed percent deviation thresholds believed to be ecologically critical. Yet, short pre- and post-impact flow records often make it difficult to determine whether changes exceeding tolerable thresholds are due to dam operations or natural variability. Through a hypothetical reservoir operations example, we incorporate the uncertainty of dam-induced streamflow changes into a Bayesian decision tree framework that evaluates tradeoffs between expected regrets associated with hydropower and ecology. The likelihood of over-protection (type I) and under-protection (type II) errors associated with hypothesis tests are used to compute expected hydropower and ecosystem regrets associated with dam operation decisions. We examine changes to high (annual Q5) and low flows (annual Q95) in typical years using a modified and extended nonparametric ranked-sum test that accounts for percent deviation thresholds. A multiple comparison test is then used to determine the likelihood of at least one threshold violation. An example shows that our decision-theoretic approach can lead to different dam operation recommendations than do other common methods, and highlights limitations that arise when the type I error rate is selected a priori. While we illustrate a hydropower-ecosystem tradeoff, our approach can also be applied to other multi-stakeholder reservoir and river management conflicts.

Bayesian decision-making, environmental flows, flo↗
DOE OSTI2017

Integrated Disposal Facility Performance Assessment: Modeling Consistency to Support Regulatory Decision Making at Hanford - 17398

Under DOE Order 435.1, 'Radioactive Waste Management', Washington River Protection Solutions, LLC and INTERA, Inc are currently preparing a performance assessment for the Hanford Integrated Disposal Facility, a near-surface low-activity waste disposal facility located on the Hanford Site in southeast Washington State. The disposal facility is expected to receive vitrified low-activity waste produced at the Hanford Waste Treatment and Immobilization Plant, as well as other secondary solid wastes generated during the treatment process. The performance assessment performs the analyses that will be relied upon to receive the Disposal Authorization Statement, establish waste acceptance criteria, modify the RCRA permit for the facility and make a waste-incidental-to-reprocessing determination for the vitrified tank waste. In January 2006 in the case State of Washington v. Bodman (Civil No. 2:03-cv-05018-AAM), DOE, the Washington State Department of Ecology (Ecology) and the State of Washington Attorney General's office reached a settlement agreement in Ecology's claim regarding off-site waste shipments to Hanford and the adequacy of modeling in the environmental impact statement. In response to the agreement, the DOE Office of Environmental Management set a policy to establish a consistent use of commercially available and public domain software for a vadose zone and groundwater model platform to support regulatory decisions at Hanford. In October 2012, the Associate Principal Deputy Assistant Secretary for Environmental Management released a memorandum to the manager of the Richland Operation Office directing how future environmental modeling activities to support regulatory decision making on the Hanford Site would be undertaken to be consistent with the 2006 settlement agreement. The preparation of the performance assessment must meet DOE Order 435.1 requirements and the additional direction provided by DOE. This paper will identify the approach taken to comply with the requirements in the 2012 memorandum. The paper will describe how environmental modeling performed for the 2017 Integrated Disposal Facility Performance Assessment was planned in a phased approach and how the current modeling is tied to the analyses that supported the decisions made in the environmental impact statement published in 2012. Additionally, the selection and qualification of the software selected to perform modeling activities for the performance assessment will be described. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Integrating regulatory, programmatic and technical needs for modeling tools to support decision-making - 15219

The U.S. Department of Energy (US DOE) Office of Environmental Management (EM), Office of Soil and Groundwater Remediation, is supporting development of the Advanced Simulation Capability for Environmental Management (ASCEM). ASCEM provides a modeling work-flow to support decision-making for site restoration, tank closure and waste management activities. Potential users involved in regulatory applications (e.g., performance and risk assessments and other activities supporting regulatory decisions) are a key target group for the tool-set. Decision-making in these applications often requires consideration of multiple perspectives, including: regulators and the public, oversight and project management personnel, as well as practitioners involved in conducting the calculations, each with different interests. From its inception, a key objective of the ASCEM project has been to actively seek input from these different user perspectives to help guide development. ASCEM formed a User Steering Committee (USC) with membership representing interests from management/staff at DOE Site Contractors, DOE-HQ and Field offices and Regulators (State and Federal). The project also provides opportunities for input from the broader user community through participation in meetings of the Performance and Risk Assessment (P and RA) Community of Practice (CoP), routine briefings and participation in meetings of the Low-Level Waste Disposal Facility Federal Review Group, and direct interactions with users involved in regulatory applications. Interactions with users involved in regulatory applications have influenced the requirements for the tool-sets and are reflected in capabilities that have been and are being implemented. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Needs for integrated risk assessment to support optimal environmental management decisions - 15455

Cleaning up legacy waste from 50 years of nuclear weapons production and energy research still remains a challenge for the U.S. Department of Energy (DOE). The DOE environmental management program is currently forecasted to run through at least late 2060's with an estimated liability of $204 billion. Risks to human health of workers and the public, the ecological system, and nuclear safety of cleanup activities continue to drive the cost of DOE's cleanup programs. Currently, these risks are generally assessed and managed independently of each other. Except for DOE self-regulated on-site disposal activities of low-level radioactive waste, risks to human health and the environment are generally under the purview of U.S. Environmental Protection Agency and State regulatory agencies, while nuclear safety risks are regulated by DOE with oversight from the U.S. Nuclear Regulatory Commission and the Defense Nuclear Facilities Safety Board where appropriate. When managing health and environmental risks, the individual regulatory authorities often use an area-by-area (or unit-by-unit), contaminant-by-contaminant (chemical-by-chemical or radionuclide-by-radionuclide) approach, focusing on a single medium (soil, water, or air), a single source (e.g., a burial ground or a processing facility), and a single receptor (e.g, a groundwater well or a creek). This level of segregation in risk evaluations by risk category, geographical location, and operational unit, as well as the corresponding separation of regulatory authorities poses a significant challenge to reaching an optimal decision in prioritizing and managing cleanup activities. This management challenge adds another layer of complexity to large-scale cleanup effort at complex sites such as the Hanford site in eastern Washington. Therefore, to support a scientifically sound, operationally robust decision making process, there is a need for an integrated, holistic approach to risk assessment that addresses the combined effects of all major contributing factors. Previous studies have pointed out the need for integrated risk assessments that address multi-contaminant, multimedia, multi-pathway exposures, for the purposes of evaluating risks to human health and the environment. We believe that a comprehensive risk assessment should also take into nuclear safety risks that are associated with handling of nuclear material either retrieved from burial sites or to be decommissioned from nuclear facilities. Recent efforts, such as the Consortium for Risk Evaluation with Stakeholder Participation (CRESP)-led Hanford site-wide independent risk review that will categorize all types of risks at the Hanford site and the DOE complex-wide risk review mandated by the Fiscal Year 2014 Consolidated Appropriations Act ('Omnibus bill'), are beginning to more comprehensively address this need. This paper provides a categorization of various types of risks present at typical DOE sites, reviews the current risk assessment and management practices, and discusses the needs for integrating nuclear safety into performance and risk assessments for optimal cleanup decisions. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Panel Session 33: Aligning Decision-Making to Deliver Timely Performance in Large Results-Based Programs

The panel focused on results-based project execution and ways to improve the effectiveness of program and project-specific decisions by gearing them to consistently achieving timely, cost-efficient, and sustainable results. Panelists discussed the complexities of making sound, actionable decisions in the face of budgetary, resource and technological constraints. Toward that end, the 10 panelists responded to the following questions: 1. What decision-making process has been most effective for you and your project team? 2. How effective are the incentives in your contract? 3. What would you be doing differently if your project were being executed on purely commercial terms? 4. Are your Contractor Assurance Programs effective? 5. Have we challenged industry and national laboratories to deliver revolutionary rather than evolutionary technologies to solve challenges? 6. What can we do to make stakeholder involvement more meaningful? 7. How do you apply lessons learned from events and issues like the Mixed Oxide Facility (MOX), the Plutonium Finishing Plant (PFP) event, and the Waste Isolation Pilot Plant (WIPP) incident?.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2022

Effects of random forest modeling decisions on biogeochemical time series predictions

Abstract Random forests (RF) are an increasingly popular machine learning approach used to model biogeochemical processes in the Earth system. While RF models are robust to many assumptions that complicate deterministic models, there are several important parameterization decisions for appropriate use and optimal model fit. We explored the role that parameter decisions, including training/testing data splitting strategies, variable selection, and hyperparameters play on RF goodness‐of‐fit by constructing models using 1296 unique parameter combinations to predict concentrations of nitrate, a key nutrient for biogeochemical cycling in aquatic ecosystems. Models were built on long‐term, publicly available water quality and meteorology time series collected by the National Estuarine Research Reserve monitoring network for two contrasting ecosystems representing freshwater and brackish estuaries. We found that accounting for temporal dependence when splitting data into training and testing subsets was key for avoiding over‐estimation of model predictive power. In addition, variable selection, the ratio of training to testing data, and to a lesser degree, variables per split and number of trees, were significant parameters for optimizing RF goodness‐of‐fit. We also explored how model parameter decisions influenced interpretation of the relative importance of predictors to the model, and model predictor‐dependent variable relationships, with results suggesting that both data structure and model parameterization influence these factors. Because much of the current RF literature is written for the computational and statistical science communities, the primary goal of this study is to provide guidelines for aquatic scientists new to machine learning to apply RF techniques appropriately to aquatic biogeochemical datasets.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

Communities in energy transition: exploring best practices and decision support tools to provide equitable outcomes

Abstract The U.S. coal industry has been in a state of decline for the past decade, a trend ushered by flat electricity demand, increased regulatory pressure, and market competition from cost-competitive clean energy sources. The receding economic viability of the coal industry has been acutely felt by the communities with immediate economic ties to coal-fired generation. With the energy transition underway, the question of how to engage communities as stakeholders in the decision-making process and address their needs through an equitable and just transition remains unresolved. To that end, this paper explores the economic, environmental, and social challenges presented by the energy transition at the community level, highlighting four case studies from transitioning coal-dependent communities across the United States to ultimately identify best practices in coal plant decommissioning processes. This paper weaves these community-identified best practices into two support tools—a decommissioning checklist and a redevelopment decision-making framework—that can be used to engage communities in the power plant retirement decision, the site reclamation phase, and eventual redevelopment of the site and revitalization of the surrounding community.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2015

Creating a spatial multi-criteria decision support system for energy related integrated environmental impact assessment

By their spatially very distributed nature, profitability and impacts of renewable energy resources are highly correlated with the geographic locations of power plant deployments. A web-based Spatial Decision Support System (SDSS) based on a Multi-Criteria Decision Analysis (MCDA) approach has been implemented for identifying preferable locations for solar power plants based on user preferences. The designated areas found serve for the input scenario development for a subsequent integrated Environmental Impact Assessment. The capabilities of the SDSS service get showcased for Concentrated Solar Power (CSP) plants in the region of Andalusia, Spain. The resulting spatial patterns of possible power plant sites are an important input to the procedural chain of assessing impacts of renewable energies in an integrated effort. The applied methodology and the implemented SDSS are applicable for other renewable technologies as well. - Highlights: • The proposed tool facilitates well-founded CSP plant siting decisions. • Spatial MCDA methods are implemented in a WebGIS environment. • GIS-based SDSS can contribute to a modern integrated impact assessment workflow. • The conducted case study proves the suitability of the methodology.

14 SOLAR ENERGY↗
DOE OSTI2015

Analysis of the Environmental Impact Assessment (EIA) Directive and the EIA decision in Turkey

The Environmental Impact Assessment (EIA) Directive first entered into force in the United States in 1969, and began to be implemented in many other countries by 1990. The first Environmental Impact Assessment (EIA) Directive in Turkey was published on February 7, 1993, under the Environmental Law No. 2872. The EIA Directive was revised seven times on June 23, 1997, June 6, 2002, December 16, 2003, July 17, 2008, October 3, 2013, and November 25, 2014. Several amendments were made during this process. The first EIA Directive dated 1993 was narrow in scope and its procedure was long, while the amendments in 2003, 2008, 2013, and 2014 widened the scope of the EIA, and shortened the EIA assessment procedures. In this study, the amendments to the Turkish EIA Directive were analysed, and their effect on the number of EIA decisions made was addressed. It was concluded that the uncertainties in EIA procedures were removed, procedures were shortened, and as a result, the number of EIA decisions increased thanks to the revisions made in line with harmonisation with European Union (EU) acquis. - Highlights: • Demonstrates the Environmental Impact Assessment practices in Turkey. • Demonstrates the application of the EIA in Turkey by sector. • Demonstrates the amendments of the EIA by-laws in Turkey. • Demonstrates the changes in EIA practices and EIA decisions.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Combination of life cycle assessment, risk assessment and human biomonitoring to improve regulatory decisions and policy making for chemicals

Prior to market entry, new chemical substances are assessed for their risk to human health and the environment. Conventional risk assessment (RA) is limited in scope, i.e. it usually does not cover the entire life cycle of a substance, nor does it take into account sustainability aspects such as the amount of raw materials and energy required to produce the substance. Life cycle assessment (LCA) can provide this pivotal information to support an informed decision on the sustainability of a new substance. Unfortunately, LCA has had little regulatory application up to now. We believe that increasing the focus on combined use of LCA and life cycle-based RA could lead to improved regulatory long-term decisions for marketed chemicals. Inclusion of human biomonitoring could increase the robustness of such decisions even further. In addition, the combined use of the three methods allows a robust search for sustainable alternatives of currently marketed chemicals that have an unfavourable risk profile. - Highlights: •We recommend a framework of three approaches for a chemical safety assessment. •LCA evaluates the sustainability of chemicals in comparison to alternatives. •Human biomonitoring allows the assessment of total exposure to critical chemicals. •A case study on nanomaterials demonstrates the value of the combined approach.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2021

Farmer characteristics and decision-making: A model for bioenergy crop adoption

We report the commercial development of biofuels and bioproducts depends on whether renewable biomass feedstock is available while not directly competing with the production of food. Farmers are one of the most important stakeholders in the biofuel supply chain and confront a range of uncertainties while entering the bioenergy market. Their decision-making process is extremely complex and rarely purely rational. Modeling farmer behavior requires considering a wide range of individual-level factors, socio-temporal dynamics, institutional settings, and their interactions. These characteristics make agent-based modeling a suitable framework for evaluating such systems. We developed a model to simulate farmer bioenergy crop adoption behavior across a 50-county study region in Nebraska, Kansas, and Colorado. The analysis considers adoption decisions for two bioenergy feedstocks, crop residues and energy crops. We examine the influence of individual and farm characteristics, market structure, social networks, and media influence on farmer adoption decisions. Our results indicate that different factors can have varied impacts on the speed of adoption for the crop residues and energy crops. Identifying levers that have the most impact on grower adoption can inform the design of interventions both from policy and private sector standpoints with important implications for the future the bioenergy industry.

09 BIOMASS FUELS↗
DOE OSTI2022

Economic dispatch for electricity merchant with energy storage and wind plant: State of charge based decision making considering market impact and uncertainties

Here this paper investigates how the market impact of electricity merchants and uncertainty of wind generation affect their co-optimized scheduling policy, specifically for merchants who have both energy storage and wind plants. In the existing literature, merchants' trading actions are usually assumed not to affect market prices; however, a large-scale energy storage merchant's actions can affect market prices. To this end, we approximate the electricity price by a linear function of the quantity of power traded by the merchant in the reward function to achieve decision-making incorporating the market impact. This paper utilizes the dynamic programming approach to analyze merchants' optimal multi-period decision-making incorporating market impact, uncertain wind generation, and energy storage constraints. First, our results demonstrate that for a merchant with co-located energy storage facilities and wind power plants, the energy storage's feasible state of charge (SOC) range can be segmented into four possible sub-ranges by three analytically developed SOC reference points. The unique optimal trading decision can be achieved by comparing the current energy inventory and the SOC references of the next period. Second, our results show that market impact and uncertainties substantially change the optimal storage scheduling policy by impacting the values of the reference points. To mitigate the negative effect of the merchant's market impact on buying and selling actions, the merchant may reduce the amount of generating or pumping electricity each period to maximize profit. Moreover, we identify and investigate the trade-off between market price and transaction quantity. Our findings provide co-optimized scheduling guidance for electricity merchants with co-located energy storage and renewable power plants systems.

17 WIND ENERGY↗
DOE OSTI2020

A web-based decision support system for collaborative mitigation of multiple water-related hazards using serious gaming

The paper presents a web-based application developed as a medium for executing a serious game to enhance multi-jurisdictional collaborative planning and decision making for mitigation of multiple hazards related to water (i.e., floods, soil erosions, water quality). The gaming application is integrated into the Iowa Watershed Decision Support System (IoWaDSS) designed to serve as a comprehensive multi-sectoral data repository along with the simulation results of process modeling to educate and inform communities on the status of their watersheds during extreme conditions. The interactive serious gaming application was devised to encourage public engagement, facilitate communication and positive relationship between watershed communities, and make the decision process more attractive and transparent for the stakeholders. The web environment offers easily-accessible, user-friendly interfaces that match the skills and knowledge level of a non-technical user. Developed with adaptive design and flexible architecture, the gaming application is generalizable and extendable to support hazard mitigation in other watersheds.

54 ENVIRONMENTAL SCIENCES↗