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A memory read operation is directed at a group of semiconductor devices from which a first semiconductor device has been removed. An error in data for the memory read operation is detected based on error-correction coding (ECC). The error is caused at least in part by the first semiconductor device having been removed. ECC is used to determine corrected data for the memory read operation.
Hybrid x-ray fluorescence and K-edge densitometry is used at nuclear fuel reprocessing facilities to determine the concentrations of uranium and plutonium in the input accountability vessel. The uranium concentration is determined by K-edge densitometry, that is, from the step-difference in transmission on either side of the K-absorption edge measured using a continuous x-ray spectrum on a vial of the solution defining a well-known geometry. Historically this was done using a basic region of interest analysis but recently to accommodate more challenging solution full spectral analysis has been developed with considerable benefits. In parallel with the transmission measurement, the relative plutonium-to-uranium concentration is obtained from the relative strength of the x-ray–induced K-shell x-ray fluorescence production measured at a backward angle in energy-dispersive mode. However, gamma-ray emissions from fission products present in the solution also cause fluorescence of the characteristic actinide x-rays. Uncorrected, these self-irradiation–induced x-rays can introduce a bias into the reported U:Pu result. The commonly implemented method to correct this interference requires acquisition of a long (~8 hour) passive spectra for the sample. Although effective, it is often impractical to perform a passive measurement on every sample such that a representative passive spectrum is used. We have developed an alternative correction methodology using only the active x-ray fluorescence spectrum that eliminates the requirement for the time-consuming passive count. The active self-interrogation methodology will be discussed and initial performance results presented.
In general, data is susceptible to errors caused by faults in hardware (i.e. permanent faults), such as faults in the functioning of memory and/or communication channels. To detect errors in data caused by hardware faults, the error correcting code (ECC) was introduced, which essentially provides a sort of redundancy to the data that can be used to validate that the data is free from errors caused by hardware faults. In some cases, the ECC can also be used to correct errors in the data caused by hardware faults. However, the ECC itself is also susceptible to errors, including specifically errors caused by faults in the ECC logic. A method, computer readable medium, and system are thus provided for securing against errors in an ECC.
Neutrino oscillation experiments at accelerator energies aim to establish CP violation in the neutrino sector by measuring the energy-dependent rate of $\nu_e$ appearance and $\nu_\mu$ disappearance in a $\nu_\mu$ beam. Extracting the correct oscillation rate demands control over QED radiative corrections at the percent level. Focusing on the critical charged-current neutrino-nucleon scattering process, we show that the cross section factorizes into two pieces. The first piece depends on hadron structure but is universal for $\nu_e$ and $\nu_\mu$, and hence constrained by high-statistics $\nu_\mu$ data. The second piece is nonuniversal and suffers large logarithm enhancements, but is computed to high precision using renormalization group improved perturbation theory. Our results provide a missing ingredient for the robust interpretation of current NOvA and T2K experiments, and can be applied to future experiments such as DUNE and HyperK.
Isospin-breaking corrections to the hadron vacuum polarization component of the anomalous magnetic moment of the muon are needed to ensure the theoretical precision of $g_\mu -2$ is below the experimental precision. We describe the status of our work calculating, using lattice QCD, the QED correction to the light and strange connected hadronic vacuum polarization in a Dashen scheme. We report results using physical $N_f=2+1+1$ HISQ ensembles at three lattice spacings and three heavier-than-light valence quark masses.
Embodiments of the present disclosure are related to training one or more of machine learning algorithms in a virtual reality environment for error detection and correction and/or for employing one or more trained machine learning models in an augmented reality environment to detect and/or correct user errors associated the performance of one or more tasks.
The description of deep-inelastic lepton-nucleon scattering at finite values of Q2 requires subleading corrections such as those arising from target mass corrections (TMCs) to be accounted for, particularly at large values of the parton momentum fraction x. The standard method of incorporating TMCs via Nachtmann moments of structure functions, constructed from local operators within the operator product expansion, is known to have practical difficulties reproducing the corresponding Cornwall-Norton moments of the structure functions without TMCs. We consider several potential resolutions of this paradox, and discuss consequences for the interpretation of parton distributions at finite values of Q2.
The Tomographic Gamma Scanner (TGS) is a Non-Destructive Assay (NDA) instrument that combines high-resolution gamma spectroscopy with low spatial resolution three-dimensional image reconstruction in order to reduce bias and improve precision for measurements of drummed waste. The TGS technique is especially suited to measure containers with non-uniform source distributions and low-to me-dium-density heterogeneous matrices, compared with traditional NDA methods. Canberra recently built, installed, and commissioned a TGS system, intended primarily for the measurement of plutonium (Pu) bearing waste, at a European nu-clear fuel reprocessing facility. Pu assays using the TGS technique present technical challenges distinct from those typically encountered in traditional LLW applications. Among these is the need to apply corrections for self-absorption effects that occur on scales smaller than the TGS spatial resolution, and can compromise the assay result if not included in the TGS imaging methodology. We present a brief review of the Self Absorption Correction (SAC) technique, and discuss the complications involved with its application to the TGS methodology with examples from our recent experience. This work continues a Canberra history of further developing and refining a technique to solve emerging problems, having commercialized the original methodology by partnering with the research institution that pioneered it. The TGS and the SAC methodologies were originally developed by Los Alamos National Laboratory (LANL) and John Fleissner respectively, and this work illustrates how Canberra has implemented an advancement of these techniques in a new TGS system. (authors)
The strategy to close the Rainier Mesa/Shoshone Mountain (RMSM) Corrective Action Unit (CAU) of the Underground Test Area (UGTA) Project at the Nevada National Security Site (NNSS) is defined under a joint agreement between the State of Nevada, the U.S. Department of Energy (DOE) and the Department of Defense (DoD). That strategy required a corrective action investigation (CAI) to define the evolution of contaminated volumes of groundwater under uncertainty as a means to define a surface-projected contaminant boundary and serve as a basis for longer term monitoring. As the initial phase of the CAI was nearing completion in 2012, concerns were raised as to whether the original Federal Facility Agreement and Consent Order (FFACO) strategy was achievable. This was evident when the complexity of the system and the additional costs required to sufficiently characterize it were judged to be out of balance with the overall perceived risks (low) associated with this particular CAU. As a result, an Alternative Modeling Strategy (AMS) and New FFACO Strategy Decision Process for UGTA RM/SM CAU were approved in November 2013. The AMS removes the requirement for developing ensembles of 3D contaminant transport simulations and replaces it with a simpler one requiring the generation of multiple 1D streamline models. These are meant to encompass a range of alternative, yet plausible release and transport scenarios as a means to bound the overall lateral extent of contaminant transport. The new Decision Process is streamlined and progresses from the revised CAI stage, to an external peer review, and then, upon favorable evaluation, directly to a closure stage. Although the project has suffered some delays from implementation of the new strategy, the new process of achieving closure is expected to save several years in time and several million dollars over the original process while still protecting human health and the environment over the 1,000-year compliance period stipulated in the FFACO. (authors)
Non-destructive active neutron assay techniques such as active neutron coincidence counting, differential die away analysis or the californium shuffler method rely on the interrogation of fissile nuclear materials by an external neutron source. Whether it is a spontaneous fission or (α,n) neutron source, like {sup 252}Cf or AmLi; or a fusion neutron generator, all of these techniques rely on induced secondary fission events to provide prompt or delayed neutron signals that serve as the basis for the fissile material quantification. The accuracy of these fissile mass measurements is therefore dependent on the neutron interrogation efficiencies determined for calibration reference standards and whether the measured items are comparable to the calibration condition. In such favorable conditions, it is possible to establish a reliable empirical non-linear relationship between apparent (uncorrected) and real or true fissile mass. However, in waste measurements, this is unlikely to be the case; thus a calibration approach that takes account of the neutron self-shielding effect is required. By incorporating the Self-Shielding Factor (SSF) of the calibration reference standards, a linear mass calibration factor [s{sup -1}. {sup 239}Pu{sub eq} g{sup -1}] can be found; this calibration is accurate for waste in which the fissile material is 'infinitely dilute' i.e. the waste exhibits no self-shielding; this is assumed to be representative of dispersed material. The self-shielding correction and its systematic uncertainty are then left to be treated as part of the Total Measurement Uncertainty (TMU) evaluation associated with the assay result. The derivation of the TMU contribution associated with the self-shielding effect in nuclear waste is a complex problem for which a reliable evaluation has to be performed. This is usually based on assuming 'worst case scenarios' for the distribution of material that can arise in a particular waste stream. Such an approach is conservative, but often very penalizing, especially if one considers larger lumps (those containing grams of fissile material); for such lumps, the self-shielding correction becomes very significant, potentially altering the mass of {sup 239}Pu{sub eq} by over an order of magnitude. A worst case 'nuclear safety value' may not be the most appropriate choice for building a consignment best estimate or repository sentencing value for an item. In the present work the authors describe a numerical approach to study the variability of neutron self-shielding factors associated with distributions of a wide range of lump characteristics in terms of size, shape, chemical composition, density and isotopic composition. The described novel calculation tool is capable of accurately predicting the real impact of random distribution of lumps in a waste material, and allowed to show that given reasonable, defensible, assumptions on the composition of the lumps in waste stream, the systematic error component of the DDA TMU can be significantly reduced. (authors)
The numerical code DRSPALL (from direct release spallings) is written to calculate the volume of Waste Isolation Pilot Plant solid waste subject to material failure and transport to the surface (i.e., spallings) as a result of a hypothetical future inadvertent drilling intrusion into the repository. An error in the implementation of the DRSPALL finite difference equations was discovered and documented in a software problem report in accordance with the quality assurance procedure for software requirements. This paper describes the corrections to DRSPALL and documents the impact of the new spallings data from the modified DRSPALL on previous performance assessment calculations. Updated performance assessments result in more simulations with spallings, which generally translates to an increase in spallings releases to the accessible environment. Total normalized radionuclide releases using the modified DRSPALL data were determined by forming the summation of releases across each potential release pathway, namely borehole cuttings and cavings releases, spallings releases, direct brine releases, and transport releases. Because spallings releases are not a major contributor to the total releases, the updated performance assessment calculations of overall mean complementary cumulative distribution functions for total releases are virtually unchanged. Therefore, the corrections to the spallings volume calculation did not impact Waste Isolation Pilot Plant performance assessment calculation results. (authors)
The Underground Test Area (UGTA) Project of the U.S Department of Energy (DOE) is investigating radionuclide contaminant movements in groundwater derived from a decades-long period of underground nuclear testing at the Nevada National Security Site (NNSS) to support regulatory corrective action and closure requirements. The project is built around an integrated campaign of drilling and sampling, data interpretation, computer modeling, and broader monitoring activities conducted under a joint Federal Facilities Agreement and Consent Order (1996 as amended) (FFACO) between the State of Nevada, the DOE, and the U.S. Department of Defense. The FFACO strategy is applied to individual Corrective Action Units (CAUs) that roughly envelop disparate geographic testing areas at the NNSS. The Rainier Mesa/Shoshone Mountain (RMSM) CAU is a geologically and hydrologically complex system lying in a remote up-gradient section of the NNSS. It was the site of 67 underground tests conducted between 1957 and 1992, 61 at Rainier Mesa proper, and 6 at Shoshone Mountain, isolated to its south. The original strategy to close the RMSM CAU required a simulation-based investigation to define the evolution of contaminated volumes of groundwater (in 3D) under uncertainty as a means to define a surface-projected contaminant boundary and to serve as a basis for longer term monitoring activities. Early models developed under this strategy proved to be quite complex and difficult to calibrate. Additional costs required to better characterize the system were judged to be out of balance with the low risks associated with this particular CAU. As a result, an Alternative Modeling Strategy (AMS) was adopted. The AMS removes the requirement for developing ensembles of 3D simulations and replaces it with a simpler one requiring the generation of multiple 1D streamline models. These are meant to encompass a range of alternative, yet plausible release and transport scenarios as a means to bound the overall lateral extent of contaminant transport. This paper will review the modeling approach developed under the AMS and its application to the Rainier Mesa portion of the CAU. Preliminary model results made under different parametric assumptions and boundary condition scenarios will be presented. Additional refinements of the model and its further application will be discussed. (authors)
This work will compare the Allen method and Walker method of accounting for subhourly inverter clipping power losses in hourly PV performance models. The Allen method uses a matrix lookup based on DNI clearness and clipping potential to assign a clipping correction loss at each simulation timestep. The Walker method models the PV DC power input to the inverter as a distribution over the hourly timestep and uses integration over the timestep to determine the amount of clipping that occurs within the timestep. Both these models have been recently implemented in the System Advisor Model's (SAM) open-source code, and will be applied to hourly SURFRAD datasets to analyze the subhourly clipping loss predicted by each model for different system designs and inverter loading conditions. Both models will be compared to "true" 1-minute SURFRAD data simulations to see their accuracy against more accurate 1-minute clipping correction loss predictions. This model comparisons will be investigated in more detail at the PVSC conference in Seattle, Washington June 2024.
Approximate quantum error correction (AQEC) not only dictates the performance of discrete- and continuous-variable quantum error correction codes but also serves as a unifying framework across various physical disciplines. Identifying the optimal recovery channel to maximize the entanglement fidelity via standard semidefinite programming is computationally bottlenecked by the exponentially growing number of Kraus operators with system size, rendering large-scale optimization prohibitive. While analytical near-optimal maps exist, they typically work only when the Knill-Laflamme conditions are nearly satisfied. In this Letter, we establish an efficient framework by leveraging the duality between recovery and environment decoupling. This framework yields a tighter analytical lower bound on entanglement fidelity than the conventional limit set by the transpose channel. Furthermore, by exploiting the decayed weights of noise Kraus operators, we introduce a framework based on principal component analysis to reduce the dimension. In thermal loss channels where the weights decay exponentially, our approach achieves a 33-fold computational speedup while maintaining rigorous accuracy. Our approach enables high-precision optimization for AQEC codes that were previously intractable due to the curse of dimensionality.
Motivated by the wide range of kinematics covered by current and planned deep-inelastic scattering (DIS) facilities, we revisit the formalism, practical implementation, and numerical impact of target mass corrections (TMCs) for DIS on unpolarized nuclear targets. An important aspect is that we only use nuclear and later partonic degrees of freedom, carefully avoiding a picture of the nucleus in terms of nucleons. After establishing that formulae used for individual nucleon targets (p,n), derived in the Operator Product Expansion (OPE) formalism, are indeed applicable to nuclear targets, here we rewrite expressions for nuclear TMCs in terms of re-scaled (or averaged) kinematic variables. As a consequence, we find a representation for nuclear TMCs that is approximately independent of the nuclear target. We go on to construct a single-parameter fit for all nuclear targets that is in good numerical agreement with full computations of TMCs. We discuss in detail qualitative and quantitative differences between nuclear TMCs built in the OPE and the parton model formalisms, as well as give numerical predictions for current and future facilities.
The electronic properties and Seebeck coefficients of Ce{sub 3}Te{sub 4} and La{sub 3}Te{sub 4} are computed using Density Functional Theory with on-site Coulomb interaction correction. We found that the Seebeck coefficients of Ce{sub 3}Te{sub 4} and La{sub 3}Te{sub 4} are almost equal at temperatures larger than the Curie temperature of Ce{sub 3}Te{sub 4}, and in good agreement with the measurements reported by May et al. [Phys. Rev. B 86, 035135 (2012)]. At temperatures below the Curie temperature, the Seebeck coefficient of Ce{sub 3}Te{sub 4} increases due to the ferromagnetic ordering, which leads the f-electron of Ce to contribute to the Seebeck coefficient in the relevant range of electron concentration.
In this paper, we investigate the electronic structure of a planar mononuclear Cu-based molecule [Cu(C 6 H 4 S 2 ) 2 ] z in two oxidation states ( z = –2, –1) using density-functional theory (DFT) with Fermi–Löwdin orbital (FLO) self-interaction correction (SIC). The dianionic Cu-based molecule was proposed to be a promising qubit candidate. Self-interaction error within approximate DFT functionals renders severe delocalization of electron and spin densities arising from 3 d orbitals. The FLO-SIC method relies on optimization of Fermi–Löwdin orbital descriptors (FODs) with which localized occupied orbitals are constructed to create SIC potentials. Starting with many initial sets of FODs, we employ a frozen-density loop algorithm within the FLO-SIC method to study the Cu-based molecule. We find that the electronic structure of the molecule remains unchanged despite somewhat different final FOD configurations. In the dianionic state (spin S = 1/2), FLO-SIC spin density originates from the Cu d and S p orbitals with an approximate ratio of 2:1, in quantitative agreement with multireference calculations, while in the case of SIC-free DFT, the orbital ratio is reversed. Overall, FLO-SIC lowers the energies of the occupied orbitals and, in particular, the 3 d orbitals unhybridized with the ligands significantly, which substantially increases the energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) compared to SIC-free DFT results. The FLO-SIC HOMO–LUMO gap of the dianionic state is larger than that of the monoanionic state, which is consistent with experiment. Our results suggest a positive outlook of the FLO-SIC method in the description of magnetic exchange coupling within 3 d -element-based systems.
I examine the accuracy of the TOPEX ionosphere correction; its dependence on ocean and satellite parameters is less than 1 cm.