bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recovery with Applications to Forecasting Equity Disaster Probability and Testing the Spanning Hypothesis in the Treasury Market
Authors: Bakshi Gurdip , Gao Xiaohui , Xue Jinming 
Published: July 2022

AbstractWe investigate the implications of recovering real-world conditional expectation of return functions using options on the S&P 500 index and Treasury bond futures. First, we construct estimates of the probability of disasters, defined as higher than 6%, 5%, or 4% equity market declines over option expiration cycles. This measure of disaster probability forecasts realized disasters. Second, we employ options on the futures of the 10- and 30-year Treasury bonds to construct estimates for the expected return of bond futures. These measures display forecasting ability for subsequent futures returns beyond the level, slope, and curvature variables extracted from the yield curve.
Are people with obsessive-compulsive disorder under-confident in their memory and perception? A review and meta-analysis
Authors: Dar Reuven , Sarna Noam , Yardeni Gal , Lazarov Amit 
Published: July 2022

AbstractPeople with obsessive-compulsive disorder (OCD) tend to distrust their memory, perception, and other cognitive functions, and many OCD symptoms can be traced to diminished confidence in one's cognitive processes. For example, poor confidence in recall accuracy can cause doubt about one's memory and motivate repeated checking. At the same time, people with OCD also display performance deficits in a variety of cognitive tasks, so their reduced confidence must be evaluated in relation to their actual performance. To that end, we conducted an exhaustive review and meta-analysis of studies in which OCD participants and non-clinical control participants performed cognitive tasks and reported their confidence in their performance. Our search resulted in 19 studies that met criteria for inclusion in the quantitative analysis, with all studies addressing either memory or perception. We found that both performance and reported confidence were lower in OCD than in control participants. Importantly, however, confidence was more impaired than performance in participants with OCD. These findings suggest that people with OCD are less confident in their memory and perception than they should be, indicating a genuineunder-confidencein this population. We discuss potential mechanisms that might account for this finding and suggest avenues for further research into under-confidence and related meta-cognitive characteristics of OCD.
Indoor Built Environment and Older Adults’ Activity: A Systematic Review
Authors: Azim Farah T. , Ariza-Vega Patrocinio , Gardiner Paul A. , Ashe Maureen C. 
Published: July 2022

AbstractAlthough the physical environment can influence people’s activity, there are few knowledge syntheses for indoor environments and older adults’ daily life routines. Therefore, we conducted a systematic review of peer-reviewed evidence to inform future research and practice. Inclusion criteria were studies with any research designs, across all years and languages focused on older adults 60 years of age or more, on physical activity/sedentary behaviour and the indoor environment. After searching five databases, two authors completed title/abstract and full-text screening. The last search was on December 19, 2020. We screened 1,367 citations, and included 23 studies situated in private or collective dwellings (e.g., assisted living). We identified physical activity-supportive indoor features across three domains: campus (e.g., amenities, pathways), building (e.g., area, floor level), and fixtures (e.g., elevators, hallways). Knowledge of indoor environmental factors for older adults’ engagement in daily activities can guide future research and policy on housing design.
Current developments of robotic hip exoskeleton toward sensing, decision, and actuation: A review
Authors: Yang Canjun , Yu Linfan , Xu Linghui , Yan Zehao , Hu Dongming , Zhang Sheng , Yang Wei 
Published: July 2022

Abstract
The aging population is now a global challenge, and impaired walking ability is a common feature in the elderly. In addition, some occupations such as military and relief workers require extra physical help to perform tasks efficiently. Robotic hip exoskeletons can support ambulatory functions in the elderly and augment human performance in healthy people during normal walking and loaded walking by providing assistive torque. In this review, the current development of robotic hip exoskeletons is presented. In addition, the framework of actuation joints and the high-level control strategy (including the sensors and data collection, the way to recognize gait phase, the algorithms to generate the assist torque) are described. The exoskeleton prototypes proposed by researchers in recent years are organized to benefit the related fields realizing the limitations of the available robotic hip exoskeletons, therefore, this work tends to be an influential factor with a better understanding of the development and state-of-the-art technology.
Hydroelectricity Modeling for Low‐Carbon and No‐Carbon Grids: Empirical Operational Parameters for Optimization and Dispatch Models
Authors: Marshall Adrienne M. , Grubert Emily 
Published: July 2022

AbstractHydroelectric power has unusual technical characteristics that could become more valuable as the penetration of variable generation renewables grows, but its use for electricity generation is constrained by complex physical, safety, and socioenvironmental considerations. Hydroelectricity can therefore be difficult to represent in national‐scale energy models, and is frequently presumed to be either overly flexible or inflexible. While a few grid models address this complexity via detailed hydraulic process models, more simplified optimization and dispatch models could benefit from the use of empirical parameter values. In this study, we combine a new data set comprising 7.8 million flow‐hours of data from 2011 to 2016 at 158 dams across the United States with monthly and hourly generation data from the U.S. Energy Information Administration (EIA) to elucidate such empirical constraints for the continental United States. We introduce an approach for estimating power generation from hourly water discharge, then present regionally resolved interannual seasonal and diurnal generation patterns; frequency analyses of ramp rates; minimum and maximum generation rates; daily reversals; and load duration curves, all available interactively with a new data visualization tool. We suggest that due largely to hydropower's role as power generation that also serves non‐energy purposes, it acts as a predictable variable generator with constrained dispatchability, more like a supply side analog to demand response resources than like a battery. This observation is particularly relevant for high penetration renewable energy scenarios, given hydroelectric generators' expected value for grid stabilization and load balancing.
Rheological Controls on Magma Reservoir Failure in a Thermo‐Viscoelastic Crust
Authors: Head Matthew , Hickey James , Thompson Joe , Gottsmann Joachim , Fournier Nicolas 
Published: July 2022

AbstractAs volcanoes undergo unrest, understanding the conditions and timescales required for magma reservoir failure, and the links to geodetic observations, are critical when evaluating the potential for magma migration to the surface and eruption. Inferring the dynamics of a pressurized magmatic system from episodes of surface deformation is heavily reliant on the assumed crustal rheology, typically represented by an elastic medium. Here, we use Finite Element models to identify the rheological response to reservoir pressurization within a temperature‐dependent Standard Linear Solid viscoelastic (“thermo‐viscoelastic”) domain. We assess the mechanical stability of a deforming reservoir by evaluating the overpressures required to initiate brittle failure along the reservoir wall, and the sensitivity to key parameters. Reservoir inflation facilitates compression of the ductile wall rock, due to the non‐uniform crustal viscosity, impacting the temporal evolution of the induced tensile stress. Thermo‐viscoelasticity enables a deforming reservoir to sustain greater overpressures prior to failure, compared to elastic analyses. High‐temperature (e.g., mafic) reservoirs fail at lower overpressures compared to low‐temperature (e.g., felsic) reservoirs, producing smaller coincident displacements at the ground surface. The impact of thermo‐viscoelasticity on reservoir failure is significant across a wide range of overpressure loading rates. By resisting mechanical failure on the reservoir wall, thermo‐viscoelasticity impacts dyke nucleation and formation of shear fractures. Numerical models may need to incorporate additional processes that act to promote failure, such as regional stresses (e.g., topographic and tectonic), external triggers (e.g., earthquake stress drops), or pre‐existing weaknesses along the reservoir wall.
Constraining Upper Mantle Viscosity Using Temperature and Water Content Inferred From Seismic and Magnetotelluric Data
Authors: Ramirez F. D. C. , Selway K. , Conrad C. P. , Lithgow‐Bertelloni C. 
Published: July 2022

AbstractMantle viscosity controls a variety of geodynamic processes such as glacial isostatic adjustment (GIA), but it is poorly constrained because it cannot be measured directly from geophysical measurements. Here we develop a method that calculates viscosity using empirical viscosity flow laws coupled with mantle parameters (temperature and water content) inferred from seismic and magnetotelluric (MT) observations. We find that combining geophysical constraints allows us to place significantly tighter bounds on viscosity estimates compared to using seismic or MT observations alone. In particular, electrical conductivity inferred from MT data can determine whether upper mantle minerals are hydrated, which is important for viscosity reduction. Additionally, we show that rock composition should be considered when estimating viscosity from geophysical data because composition directly affects seismic velocity and electrical conductivity. Therefore, unknown composition increases uncertainty in temperature and water content, and makes viscosity more uncertain. Furthermore, calculations that assume pure thermal control of seismic velocity may misinterpret compositional variations as temperature, producing erroneous interpretations of mantle temperature and viscosity. Stress and grain size also affect the viscosity and its associated uncertainty, particularly via their controls on deformation regime. Dislocation creep is associated with larger viscosity uncertainties than diffusion creep. Overall, mantle viscosity can be estimated best when both seismic and MT data are available and the mantle composition, grain size and stress can be estimated. Collecting additional MT data probably offers the greatest opportunity to improve geodynamic or GIA models that rely on viscosity estimates.
Diurnal Variation in Clouds and Radiative Budgets Over the Tibetan Plateau During Summer Using CERES Data
Authors: Chen Guangcan , Zhang Xiangdong , Fu Yunfei 
Published: July 2022

AbstractDiurnal variations in clouds and radiation budgets over four subareas of the Tibetan Plateau (TP) during summer (June–August) are analyzed using the Clouds and the Earth's Radiant Energy System (CERES) synoptic 1° (SYN1deg) data from 2000 to 2020. The results show that the total cloud amount decreases from southeast to northwest and is larger during daytime (71.1%) than nighttime (67.2%) over the entire TP. High‐clouds develop in the afternoon, persist during nighttime, and dissipate after sunrise. Low clouds develop after sunrise and dissipate in the afternoon over the entire TP, but show opposite temporal variation over the Kunlun Mountains. The net radiation budget at the top‐of‐atmosphere reaches its maximum at noon. The surface net radiation budget is positive in the daytime and negative at nighttime. These features are mainly adjusted by the cloud distribution. The diurnal variations in heating rate over the four subareas are similar in the upper atmosphere but different in the lower layer. The low‐atmosphere heating rate shows a maximum value over the center‐south (CS) subarea, while it is lowest over the west (W) subarea. Internal cloud forcing has distinct regional differences over the four subareas: it shows a heating effect in the low atmosphere and a cooling effect in the middle atmosphere over the CS subarea, whereas over the W subarea it shows a radiative cooling effect in the low atmosphere and no significant radiative effect in the middle layer. The findings of this study help toward improving our understanding of the TP's energy cycle.
Improving Multiday Solar Wind Speed Forecasts
Authors: Elliott H. A. , Arge C. N. , Henney C. J. , Dayeh M. A. , Livadiotis G. , Jahn J.‐M. , DeForest C. E. 
Published: July 2022

AbstractWe analyze the residual errors for the Wang‐Sheeley‐Arge (WSA) solar wind speed forecasts as a function of the photospheric magnetic field expansion factor (fp) and the minimum separation angle (d) in the photosphere between the footpoints of open field lines and the nearest coronal hole boundary. We find the map of residual speed errors are systematic when examined as a function of fp and d. We use these residual error maps to apply corrections to the model speeds. We test this correction approach using 3‐day lead time speed forecasts for an entire year of observations and model results. Our methods can readily be applied to develop corrections for the remaining WSA forecast lead times which range from 1 to 7 days in 1‐day increments. Since the solar wind density, temperature, and the interplanetary magnetic field strength all correlate well with the solar wind speed, the improved accuracy of solar wind speed forecasts enables the production of multiday forecasts of the solar wind density, temperature, pressure, and interplanetary field strength, and geophysical indices. These additional parameters would expand the usefulness of Air Force Data Assimilative Photospheric Flux Transport‐WSA forecasts for space weather clients.
Resolving Continental Magma Reservoirs With 3D Surface Wave Tomography
Authors: Maguire Ross , Schmandt Brandon , Chen Min , Jiang Chengxin , Li Jiaqi , Wilgus Justin 
Published: July 2022

AbstractSurface wave tomography is widely used to improve our understanding of continental magma reservoirs that may be capable of fueling explosive volcanic eruptions. However, traditional surface wave tomography based on inversions for phase velocity maps and locally 1D shear velocity may have difficulty resolving strong 3D low‐velocity anomalies associated with crustal magma reservoirs. Here, we perform synthetic tomography experiments based on 3D seismic waveform simulations to understand how the limitations of surface wave tomography could affect interpretations of tomography in volcanic settings. We focus our modeling on the Yellowstone volcanic system, one of the largest and most thoroughly studied continental magmatic systems, and explore scenarios in which the maximum shear velocity anomaly associated with the crustal magma reservoir ranges between −10% and −66%. We find that even with the well‐instrumented setting near Yellowstone, the recovered shear velocity anomalies in the mid‐to‐upper crust are severely diminished due to the small spatial scale of the reservoir with respect to the seismic wavelengths that sample it. In particular, recovered VS anomalies could be reduced by a factor of two or more, implying that the inferred melt fraction of large‐scale continental magma reservoirs may be considerably underestimated.
DMSP Poynting Flux: Data Processing and Inter‐Spacecraft Comparisons
Authors: Kilcommons Liam M. , Knipp Delores J. , Hairston Marc , Coley W. Robin 
Published: July 2022

AbstractPoynting flux (PF) calculated from low Earth orbit spacecraft in situ ion drift and magnetic field measurements is an important measure of energy exchange between the magnetosphere and ionosphere. Defense Meteorological Satellite Program (DMSP) spacecraft provide an extensive back‐catalog of ion drift and magnetic perturbation measurements, from which quasi‐steady PF could be calculated. However, since DMSP are operations‐focused spacecraft, data must be carefully preprocessed for research use. We describe an automated approach for calculating earthward PF focusing on pre‐processing and quality control. We produce a PF data set using nine satellite‐years of DMSP F15, F16, and F18 observations. To validate our process we inter‐compare PF from different spacecraft using more than 2,000 magnetic conjunction events. We find no serious systematic differences. We further describe and apply an equal‐area binning technique to obtain average spatial patterns of PF, magnetic perturbation, electric field and ion drift velocity. We perform our analysis using all components of electric and magnetic field and comment on the adverse consequences of the typical single‐electric‐field‐component DMSP PF approximation on inter‐spacecraft agreement. Including full‐field components significantly increases the relative strength of near‐cusp PF and increases the integrated high‐latitude PF by ∼25%.
Strain Partitioning Among Forearc Faults in Southern Cascadia Inferred From GNSS
Authors: Nuyen Carolyn P. , Schmidt David A. 
Published: July 2022

AbstractCrustal faults in the southern Cascadia forearc help to accommodate strains related to plate interactions near the Mendocino triple junction (MTJ). Geologic work has identified the Little Salmon fault, Mad River fault zone (MRFZ), and Grogan fault as Quaternary‐active structures; however, the slip rates on these major fault systems are poorly constrained. This work constructs elastic block models of the MTJ region and leverages GNSS velocity data to better understand how strain is partitioned among these three faults. We evaluate models with various forearc fault structures and apply a bootstrap analysis to provide independent slip rate distributions for each fault. Model results indicate that the Little Salmon fault zone is an important structure that accommodates both thrust and right‐lateral shear motion in the forearc. Appreciable right‐lateral slip rates on the MRFZ indicate that this system plays an important role in facilitating translation of the forearc and may serve as an extension of the northern San Andreas fault system. In contrast, the models place very little strike‐slip motion on the Grogan fault and prefer this structure to mainly host reverse slip. We observe the highest slip rates on the Bear River fault zone, indicating significant strain to the north of the MTJ.
Drivers, Dynamics, and Persistence of the 2017/2018 Tasman Sea Marine Heatwave
Authors: Kajtar Jules B. , Bachman Scott D. , Holbrook Neil J. , Pilo Gabriela S. 
Published: July 2022

AbstractDuring the austral summer of 2017/2018, the Tasman Sea experienced an intense marine heatwave over an extensive area. It persisted for approximately 3 months and caused substantial ecological impacts. The marine heatwave was understood to have been driven primarily by increased net downward heat flux associated with a high pressure system. However, it has been unclear why the marine heatwave persisted. Using an ultra‐high‐resolution (∼1 km) regional ocean model simulation, the drivers, dynamics, and persistence of the 2017/2018 marine heatwave are explored in detail. It is found that a burst of warm water advection helped to initiate the event, but a shallower than usual mixed layer, coupled with near continuous net downward air‐sea heat flux, caused the marine heatwave to persist. Submesoscale dynamics were found to be relatively unimportant to the marine heatwave's persistence.
Sensitivity Analysis of Wind and Turbulence Predictions With Mesoscale‐Coupled Large Eddy Simulations Using Ensemble Machine Learning
Authors: Kaul Colleen M. , Hou Zhangshuan Jason , Zhou Huifen , Rai Raj K. , Berg Larry K. 
Published: July 2022

AbstractCoupling between mesoscale models and large‐eddy simulation (LES) models is increasingly used to more realistically represent the wide range of scales of atmospheric motions affecting boundary layer winds and turbulence that need to be simulated accurately for applications such as wind energy. However, such mesoscale‐to‐microscale coupled modeling frameworks are potentially affected by a large number of uncertain closure parameters. Here, we investigate the sensitivity associated with six closure parameters related to a 1.5‐order subgrid‐scale turbulence closure for an ensemble of mesoscale‐coupled LES. The simulations are performed using the Weather Research and Forecasting model nested from horizontal resolutions of greater than a kilometer down to tens of meters. Closure parameters are varied to generate perturbed parameter ensembles for two case studies of highly sheared, convective boundary layers observed in the Columbia Basin of Oregon and Washington during the Second Wind Forecast Improvement Project. Machine learning algorithms are used to explore the sensitivity of LES predictions, considering the effects of the perturbed physical parameters alongside categorical factors such as the case study identity, measurement location, and LES resolution. For the conditions we examine, a single parameter, the eddy viscosity coefficient, is the dominant source of parametric sensitivity and its importance is comparable to the categorical factors for several of the simulation response variables we examine.
A 4DEnVar‐Based Ensemble Four‐Dimensional Variational (En4DVar) Hybrid Data Assimilation System for Global NWP: System Description and Primary Tests
Authors: Zhu Shujun , Wang Bin , Zhang Lin , Liu Juanjuan , Liu Yongzhu , Gong Jiandong , Xu Shiming , Wang Yong , Huang Wenyu , Liu Li , He Yujun , Wu Xiangjun , Zhao Bin , Chen Fajing 
Published: July 2022

AbstractThis study developed an ensemble four‐dimensional variational (En4DVar) hybrid data assimilation system. Different from most of the available En4DVar systems that adopted ensemble Kalman Filter class or ensemble data assimilation approaches to produce ensemble covariances for their hybrid background error covariances (BECs), it used a four‐dimensional ensemble variational (4DEnVar) system to obtain the ensemble covariance. The localization scheme for 4DEnVar applied orthogonal functions to decompose the correlation matrix so that it was implemented easily and rapidly. In terms of analysis quality and forecast skill, the En4DVar system was evaluated in the single‐point observation experiments and observing system simulation experiments (OSSEs) with sounding and cloud‐derived wind observations, using its standalone four‐dimensional variational (4DVar) and 4DEnVar components as references. The single‐point observation experiments visually verified the explicit flow‐dependent characteristic of the BEC due to the introduction of the ensemble covariance from the 4DEnVar system. The OSSE‐based sensitivity experiments revealed different contributions of the weight for the ensemble covariance in the En4DVar system to the forecasts in the Northern and Southern Extratropics and Tropics. A much higher weight for the ensemble covariance in a properly inflated hybrid covariance helped En4DVar produce the most reasonable analysis. The forecast initialized by En4DVar is overall better than by 4DVar and 4DEnVar, although the quality of En4DVar analysis is between those of 4DVar and 4DEnVar ensemble mean analyses. It indicates that the flow‐dependent ensemble covariance provided by 4DEnVar dominantly contributes to the improvements in the En4DVar‐initialized forecast, with certain but necessary constraint from the balanced climatological covariance.