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At least 1,747 records · Page 97

Mixed-integer programming models for optimal constellation scheduling given cloud cover uncertainty

We introduce the problem of scheduling observations on a constellation of remote sensors, to maximize the aggregate quality of the collections obtained. While automated tools exist to schedule remote sensors, they are often based on heuristic scheduling techniques, which typically fail to provide bounds on the quality of the resultant schedules. To address this issue, we first introduce a novel deterministic mixed-integer programming (MIP) model for scheduling a constellation of one to n satellites, which relies on extensive pre-computations associated with orbital propagators and sensor collection simulators to mitigate model size and complexity. Our MIP model captures realistic and complex constellation-target geometries, with solutions providing optimality guarantees. We then extend our base deterministic MIP model to obtain two-stage and three-stage stochastic MIP models that proactively schedule to maximize expected collection quality across a set of scenarios representing cloud cover uncertainty. Our experimental conclusions on instances of one and two satellites demonstrate that our stochastic MIP models yield significantly improved collection quality relative to our base deterministic MIP model. We further demonstrate that commercial off-the-shelf MIP solvers can produce provably optimal or near-optimal schedules from these models in time frames suitable for sensor operations.

47 OTHER INSTRUMENTATION↗

Tuning successive linear programming to solve AC optimal power flow problem for large networks

Successive linear programming (SLP) is a practical approach for solving large-scale nonlinear optimization problems. Alternating current optimal power flow (ACOPF) is no exception, particularly the large size of real-world networks. However, in order to achieve tractability, it is essential to tune the SLP algorithm presented in the literature. This paper presents a modified SLP algorithm to solve the ACOPF problem, specified by the U.S. Department of Energy’s (DOE) Grid Optimization (GO) Competition Challenge 1, within strict time limits. The algorithm first finds a near-optimal solution for the relaxed problem (i.e., Stage 1). Then, it finds a feasible solution in the proximity of the near-optimal solution (i.e., Stage 2 and Stage 3). The numerical experiments on test cases ranging from 500-bus to 30,000-bus systems show that the algorithm is tractable. Here the results show that our proposed algorithm is tractable and can solve more than 80% of test cases faster than the well-known Interior Point Method while significantly reduce the number of iterations required to solve ACOPF. The number of iterations is considered an important factor in the examination of tractability which can drastically reduce the computational time required within each iteration.

24 POWER TRANSMISSION AND DISTRIBUTION↗

Integration of progressive hedging and dual decomposition in stochastic integer programs

We present a method for integrating the Progressive Hedging (PH) algorithm and the Dual Decomposition (DD) algorithm of Carøe and Schultz for stochastic mixed-integer programs. Based on the correspondence between lower bounds obtained with PH and DD, a method to transform weights from PH to Lagrange multipliers in DD is found. Fast progress in early iterations of PH speeds up convergence of DD to an exact solution. As a result, we report computational results on server location and unit commitment instances.

97 MATHEMATICS AND COMPUTING↗

Two-Stage Distributionally Robust Conic Linear Programming over 1-Wasserstein Balls

Here, this paper studies two-stage distributionally robust conic linear programming under constraint uncertainty over type-1 Wasserstein balls. We present optimality conditions for the dual of the worst-case expectation problem, which characterizes worst-case uncertain parameters for its inner maximization problem. This condition offers an alternative proof, a counterexample, and an extension to previous works. Additionally, the condition highlights the potential advantage of a specific distance metric for out-of-sample performance, as exemplified in a numerical study on a facility location problem with demand uncertainty. Furthermore, cutting-plane-based algorithms, equipped with a unified scenario generation framework, are proposed for addressing both unbounded support and second-stage dual feasible regions, with a finite convergence proof under less stringent assumptions.

Wasserstein↗

eXascale PRogramming Environment and System Software (XPRESS)

Exascale systems, with a thousand times the compute capacity of today’s leading edge petascale computers, are expected to emerge during the next decade. Their software systems will need to facilitate the exploitation of exceptional amounts of concurrency in applications, and ensure that jobs continue to run despite the occurrence of system failures and other kinds of hard and soft errors. Adapting computations at runtime to cope with changes in the execution environment, as well as to improve power and performance characteristics, is likely to become the norm. As a result, considerable innovation is required to develop system support to meet the needs of future computing platforms. The XPRESS project aims to develop and prototype a revolutionary software system for extreme-­scale computing for both exascale and strong­scaled problems. The XPRESS collaborative research project will advance the state-­of-­the-­art in high performance computing and enable exascale computing for current and future DOE mission-­critical applications and supporting systems. The goals of the XPRESS research project are to: A. enable exascale performance capability for DOE applications, both current and future, B. develop and deliver a practical computing system software X-­stack, OpenX, for future practical DOE exascale computing systems, and C. provide programming methods and environments for effective means of expressing application and system software for portable exascale system execution.

97 MATHEMATICS AND COMPUTING↗

Federal Government Energy Management and Conservation Programs (Fiscal Year 2008)

Annual reports on Federal energy management respond to section 548 of the National Energy Conservation Policy Act (NECPA, Pub. L. No. 95-619), as amended, and provide information on energy consumption in Federal buildings, operations, and vehicles. Compiled by the Federal Energy Management Program, these reports document activities conducted by Federal agencies under the: Energy management and energy consumption requirements of section 543 of NECPA, as amended (42 U.S.C. § 8253); Energy savings performance contract authority of section 801 of NECPA, Pub. L. No. 95-619, as amended (42 U.S.C. §§ 8287-8287d); Renewable energy purchase goal of section 203 of the Energy Policy Act (EPAct) of 2005, Pub. L. No. 109-58 (codified at 42 U.S.C. § 15852); Federal building performance standard requirements under Section 109 of EPAct 2005, Pub. L. No. 109-58 (codified at 42 U.S.C. § 6834(a)); Requirements on the procurement and identification of energy efficient products under section 161 of EPAct 1992, Pub. L. No. 102-486 (codified at 42 U.S.C. § 8262g); Sections 431, 432, and 434 of the Energy Independence and Security Act of 2007 (EISA), Pub. L. No. 110-140 (42 U.S.C. § 8253) and section 527 of EISA (42 U.S.C. § 17143); Executive Order 13423, Strengthening Federal Environmental, Energy, and Transportation Management, 72 Fed. Reg. 3,919 (Jan. 26, 2007); Executive Order 13514, Federal Leadership in Environmental, Energy, and Economic Performance, 74 Fed. Reg. 52,117 (Oct. 5, 2009).

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Annual Report on Federal Government Energy Management and Conservation Programs (Fiscal Year 2010)

Annual reports on Federal energy management respond to section 548 of the National Energy Conservation Policy Act (NECPA, Pub. L. No. 95-619), as amended, and provide information on energy consumption in Federal buildings, operations, and vehicles. Compiled by the Federal Energy Management Program, these reports document activities conducted by Federal agencies under the: Energy management and energy consumption requirements of section 543 of NECPA, as amended (42 U.S.C. § 8253); Energy savings performance contract authority of section 801 of NECPA, Pub. L. No. 95-619, as amended (42 U.S.C. §§ 8287-8287d); Renewable energy purchase goal of section 203 of the Energy Policy Act (EPAct) of 2005, Pub. L. No. 109-58 (codified at 42 U.S.C. § 15852); Federal building performance standard requirements under Section 109 of EPAct 2005, Pub. L. No. 109-58 (codified at 42 U.S.C. § 6834(a)); Requirements on the procurement and identification of energy efficient products under section 161 of EPAct 1992, Pub. L. No. 102-486 (codified at 42 U.S.C. § 8262g); Sections 431, 432, and 434 of the Energy Independence and Security Act of 2007 (EISA), Pub. L. No. 110-140 (42 U.S.C. § 8253) and section 527 of EISA (42 U.S.C. § 17143); Executive Order 13423, Strengthening Federal Environmental, Energy, and Transportation Management, 72 Fed. Reg. 3,919 (Jan. 26, 2007); Executive Order 13514, Federal Leadership in Environmental, Energy, and Economic Performance, 74 Fed. Reg. 52,117 (Oct. 5, 2009).

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Annual Report on Federal Government Energy Management and Conservation Programs (Fiscal Year 2011)

Annual reports on Federal energy management respond to section 548 of the National Energy Conservation Policy Act (NECPA, Pub. L. No. 95-619), as amended, and provide information on energy consumption in Federal buildings, operations, and vehicles. Compiled by the Federal Energy Management Program, these reports document activities conducted by Federal agencies under the: Energy management and energy consumption requirements of section 543 of NECPA, as amended (42 U.S.C. § 8253); Energy savings performance contract authority of section 801 of NECPA, Pub. L. No. 95-619, as amended (42 U.S.C. §§ 8287-8287d); Renewable energy purchase goal of section 203 of the Energy Policy Act (EPAct) of 2005, Pub. L. No. 109-58 (codified at 42 U.S.C. § 15852); Federal building performance standard requirements under Section 109 of EPAct 2005, Pub. L. No. 109-58 (codified at 42 U.S.C. § 6834(a)); Requirements on the procurement and identification of energy efficient products under section 161 of EPAct 1992, Pub. L. No. 102-486 (codified at 42 U.S.C. § 8262g); Sections 431, 432, and 434 of the Energy Independence and Security Act of 2007 (EISA), Pub. L. No. 110-140 (42 U.S.C. § 8253) and section 527 of EISA (42 U.S.C. § 17143); Executive Order 13423, Strengthening Federal Environmental, Energy, and Transportation Management, 72 Fed. Reg. 3,919 (Jan. 26, 2007); Executive Order 13514, Federal Leadership in Environmental, Energy, and Economic Performance, 74 Fed. Reg. 52,117 (Oct. 5, 2009).

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Annual Report on Federal Government Energy Management and Conservation Programs (Fiscal Year 2012)

Annual reports on Federal energy management respond to section 548 of the National Energy Conservation Policy Act (NECPA, Pub. L. No. 95-619), as amended, and provide information on energy consumption in Federal buildings, operations, and vehicles. Compiled by the Federal Energy Management Program, these reports document activities conducted by Federal agencies under the: Energy management and energy consumption requirements of section 543 of NECPA, as amended (42 U.S.C. § 8253); Energy savings performance contract authority of section 801 of NECPA, Pub. L. No. 95-619, as amended (42 U.S.C. §§ 8287-8287d); Renewable energy purchase goal of section 203 of the Energy Policy Act (EPAct) of 2005, Pub. L. No. 109-58 (codified at 42 U.S.C. § 15852); Federal building performance standard requirements under Section 109 of EPAct 2005, Pub. L. No. 109-58 (codified at 42 U.S.C. § 6834(a)); Requirements on the procurement and identification of energy efficient products under section 161 of EPAct 1992, Pub. L. No. 102-486 (codified at 42 U.S.C. § 8262g); Sections 431, 432, and 434 of the Energy Independence and Security Act of 2007 (EISA), Pub. L. No. 110-140 (42 U.S.C. § 8253) and section 527 of EISA (42 U.S.C. § 17143); Executive Order 13423, Strengthening Federal Environmental, Energy, and Transportation Management, 72 Fed. Reg. 3,919 (Jan. 26, 2007); Executive Order 13514, Federal Leadership in Environmental, Energy, and Economic Performance, 74 Fed. Reg. 52,117 (Oct. 5, 2009).

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Annual Report on Federal Government Energy Management and Conservation Programs (Fiscal Year 2013)

Annual reports on Federal energy management respond to section 548 of the National Energy Conservation Policy Act (NECPA, Pub. L. No. 95-619), as amended, and provide information on energy consumption in Federal buildings, operations, and vehicles. Compiled by the Federal Energy Management Program, these reports document activities conducted by Federal agencies under the: Energy management and energy consumption requirements of section 543 of NECPA, as amended (42 U.S.C. § 8253); Energy savings performance contract authority of section 801 of NECPA, Pub. L. No. 95-619, as amended (42 U.S.C. §§ 8287-8287d); Renewable energy purchase goal of section 203 of the Energy Policy Act (EPAct) of 2005, Pub. L. No. 109-58 (codified at 42 U.S.C. § 15852); Federal building performance standard requirements under Section 109 of EPAct 2005, Pub. L. No. 109-58 (codified at 42 U.S.C. § 6834(a)); Requirements on the procurement and identification of energy efficient products under section 161 of EPAct 1992, Pub. L. No. 102-486 (codified at 42 U.S.C. § 8262g); Sections 431, 432, and 434 of the Energy Independence and Security Act of 2007 (EISA), Pub. L. No. 110-140 (42 U.S.C. § 8253) and section 527 of EISA (42 U.S.C. § 17143); Executive Order 13423, Strengthening Federal Environmental, Energy, and Transportation Management, 72 Fed. Reg. 3,919 (Jan. 26, 2007); Executive Order 13514, Federal Leadership in Environmental, Energy, and Economic Performance, 74 Fed. Reg. 52,117 (Oct. 5, 2009).

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Federal Government Energy Management and Conservation Programs (Fiscal Year 2009)

Annual reports on Federal energy management respond to section 548 of the National Energy Conservation Policy Act (NECPA, Pub. L. No. 95-619), as amended, and provide information on energy consumption in Federal buildings, operations, and vehicles. Compiled by the Federal Energy Management Program, these reports document activities conducted by Federal agencies under the: Energy management and energy consumption requirements of section 543 of NECPA, as amended (42 U.S.C. § 8253); Energy savings performance contract authority of section 801 of NECPA, Pub. L. No. 95-619, as amended (42 U.S.C. §§ 8287-8287d); Renewable energy purchase goal of section 203 of the Energy Policy Act (EPAct) of 2005, Pub. L. No. 109-58 (codified at 42 U.S.C. § 15852); Federal building performance standard requirements under Section 109 of EPAct 2005, Pub. L. No. 109-58 (codified at 42 U.S.C. § 6834(a)); Requirements on the procurement and identification of energy efficient products under section 161 of EPAct 1992, Pub. L. No. 102-486 (codified at 42 U.S.C. § 8262g); Sections 431, 432, and 434 of the Energy Independence and Security Act of 2007 (EISA), Pub. L. No. 110-140 (42 U.S.C. § 8253) and section 527 of EISA (42 U.S.C. § 17143); Executive Order 13423, Strengthening Federal Environmental, Energy, and Transportation Management, 72 Fed. Reg. 3,919 (Jan. 26, 2007); Executive Order 13514, Federal Leadership in Environmental, Energy, and Economic Performance, 74 Fed. Reg. 52,117 (Oct. 5, 2009).

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Final Prototype Microreactor Transportation Safety Program

This report fulfills the fiscal year 2025 M2 Milestone M2AT-25PN0802042, Final Microreactor Transportation Safety Program Planning Framework. Microreactors are compact reactors capable of producing less than 50 megawatts of electrical energy. Typically, these reactors are factory-fabricated and designed to be easily transportable by truck, rail, vessel, or air. Microreactor designs often assume that the unit can be transported containing either unirradiated or irradiated fuel. Interest in microreactors is driven by several factors, including the need to generate power at remote locations, military installations, and facilities such as data centers, and in areas recovering from natural disasters.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Packaging Certification program Methodology for Determining Dose Rates for Small Gram Quantities in Shipping Packagings

The Small Gram Quantity (SGQ) concept is based on the understanding that small amounts of hazardous materials, in this case radioactive materials (RAM), are significantly less hazardous than large amounts of the same materials. This paper describes a methodology designed to estimate an SGQ for several neutron and gamma emitting isotopes that can be shipped in a package compliant with 10 CFR Part 71 external radiation level limits regulations. These regulations require packaging for the shipment of radioactive materials, under both normal and accident conditions, to perform the essential functions of material containment, subcriticality, and maintain external radiation levels within the specified limits. By placing the contents in a helium leak-tight containment vessel, and limiting the mass to ensure subcriticality, the first two essential functions are readily met. Some isotopes emit sufficiently strong photon radiation that small amounts of material can yield a large dose rate outside the package. Quantifying the dose rate for a proposed content is a challenging issue for the SGQ approach. It is essential to quantify external radiation levels from several common gamma and neutron sources that can be safely placed in a specific packaging, to ensure compliance with federal regulations. The Packaging Certification Program (PCP) Methodology for Determining Dose Rate for Small Gram Quantities in Shipping Packagings provides bounding shielding calculations that define mass limits compliant with 10 CFR 71.47 for a set of proposed SGQ isotopes. The approach is based on energy superposition with dose response calculated for a set of spectral groups for a baseline physical packaging configuration. The methodology includes using the MCNP radiation transport code to evaluate a family of neutron and photon spectral groups using the 9977 shipping package and its associated shielded containers as the base case. This results in a set of multipliers for 'dose per particle' for each spectral group. For a given isotope, the source spectrum is folded with the response for each group. The summed contribution from all isotopes determines the total dose from the RAM in the container.

42 ENGINEERING↗

Benchmark Evaluation of the Medium-Power Reactor Experiment Program Critical Configurations

A series of small, compact critical assembly (SCCA) experiments were performed in 1962-1965 at the Oak Ridge National Laboratory Critical Experiments Facility (ORCEF) for the Medium-Power Reactor Experiment (MPRE) program. The MPRE was a stainless-steel clad, highly enriched uranium (HEU)-O 2 fueled, BeO reflected reactor design to provide electrical power to space vehicles. Cooling and heat transfer were to be achieved by boiling potassium in the reactor core and passing vapor directly through a turbine. Graphite- and beryllium-reflected assemblies were constructed at ORCEF to verify the critical mass, power distribution, and other reactor physics measurements needed to validate reactor calculations and reactor physics methods. The experimental series was broken into three parts, with the third portion of the experiments representing the beryllium-reflected measurements. The latter experiments are of interest for validating current reactor design efforts for a fission surface power reactor. The entire series has been evaluated as acceptable benchmark experiments and submitted for publication in the International Handbook of Evaluated Criticality Safety Benchmark Experiments and in the International Handbook of Evaluated Reactor Physics Benchmark Experiments .

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Comparison between the United States and United Kingdom Criticality Safety Personnel Training Program Guidance

The discipline of criticality safety (CS) has been developed in order to maintain safety in operations where significant amounts of fissionable material are to be manipulated. The operation is assessed by an individual or team of CS practitioners and an operational safety envelope is developed. The envelope can consist of limits on materials (i.e. fissionable mass, reflectors, moderators etc.), geometry (i.e. spacing, volume, etc.), and/or proscribed operating procedures which uphold a level of safety margin for personnel and equipment involved. The following paper is an overview of the similarities and differences in guidance on training programs for CS personnel at United States (US) and United Kingdom (UK) laboratories. This work was performed under the auspices of Joint Working Group 30 of the Mutual Defence Agreement between the United States and United Kingdom.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

State Energy Program Fact Sheet

The U.S. Department of Energy’s State Energy Program (SEP) provides funding and technical assistance to states, territories, and the District of Columbia to enhance energy security, advance state-led energy initiatives, and maximize the benefits of decreasing energy waste.

weatherization and intergovernmental program offic↗

On Mixed Integer Programming Formulations for the Unit Commitment Problem

We provide a comprehensive overview of mixed integer programming formulations for the unit commitment problem (UC). UC formulations have been an especially active area of research over the past twelve years, due to their practical importance in power grid operations, and this paper serves as a capstone for this line of work. We additionally provide publicly available reference implementations of all formulations examined. We computationally test existing and novel UC formulations on a suite of instances drawn from both academic and real-world data sources. Driven by our computational experience from this and previous work, we contribute some additional formulations for both production upper bound and piecewise linear produc- tion costs. By composing new UC formulations using existing components found in the literature and new components introduced in this paper, we demonstrate that performance can be significantly improved – and in the process, we identify a new state-of-the-art UC formulation.

97 MATHEMATICS AND COMPUTING↗

Communities LEAP (Local Energy Action Program) Cohort 2

The U.S. Department of Energy's (DOE) Communities LEAP (Local Energy Action Program) partners with low income, energy-burdened communities that are disadvantaged and/or experience direct economic impacts from reducing their historical reliance on fossil fuels to build community-driven action plans for clean energy-related economic development.

C-LEAP↗