bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distributed control system architecture for balancing and stabilizing traffic in the network of multiple autonomous intersections using feedback consensus and route assignment method
Authors: Wuthishuwong Chairit , Traechtler Ansgar 
Published: November 2019

Abstract
Autonomous and intelligent system show a remarkable step in urban traffic management. Autonomous Intersection Management (AIM) is an outstanding example of using an autonomous vehicle and wireless communication technology. The traffic performance of a single AIM system has been proved in many works however, traffic in the network of multiple AIMs is waiting for an implementation. Coordination of traffic between intersections in the network is an important step of managing the overall networked traffic throughput. The authors modeled the traffic network with the multi-agents concept and used the discrete consensus algorithm to coordinate between autonomous agents and implemented the rerouting algorithm in order to distribute the excessive traffics to neighbored intersections with the optimal condition. Our target is to have a balance traffic in each intersection and reaches the equilibrium where the stability has been not compromised. The results show that reaching consensus condition will bring the networked traffic to an equilibrium state where a peak traffic will not be happened. In addition, this method shows that when traffic in a network reached consensus, it will also converge to the Nash equilibrium in the finite time.
Testing effects of loss framing and checklists: evidence from a field experiment on wellness program participation in Philadelphia
Authors: Bhanot Syon P. , Roberto Christina A. , Chainani Anjali , Williamson Charles , den Braven Mehra 
Published: November 2019

AbstractLoss framing and checklist formatting are two oft-cited tools for encouraging behavior change, but there is little causal evidence on their impact in field settings. We partnered with the City of Philadelphia to test the effectiveness of these tools to increase completion of the City’s wellness program. In our experiment, 5235 City employees and retirees were randomly assigned to receive one of four postcard versions (using a 2 × 2 design), whereby we varied both framing (gain or loss) and how instructions were provided (information only or information in checklist format). Our results suggest that neither loss framing nor the checklist formatting significantly influenced the likelihood that individuals would complete the wellness tasks, or how quickly they completed the tasks. We conclude that this specific form of employee behavior may be difficult to influence through the “passive” behavioral interventions we tested, and suggest that a more “active” approach may be required in such instances.
Investigating the Effects of tDCS on Visual Orientation Discrimination Task Performance: “the Possible Influence of Placebo”
Authors: Bin Dawood A. , Dickinson A. , Aytemur A. , Howarth C. , Milne E. , Jones M. 
Published: November 2019

Abstract
The non-invasive neuromodulation technique tDCS offers the promise of a low-cost tool for both research and clinical applications in psychology, psychiatry, and neuroscience. However, findings regarding its efficacy are often equivocal. A key issue is that the clinical and cognitive applications studied are often complex and thus effects of tDCS are difficult to predict given its known effects on the basic underlying neurophysiology, namely alterations in cortical inhibition-excitation balance. As such, it may be beneficial to assess the effects of tDCS in tasks whose performance has a clear link to cortical inhibition-excitation balance such as the visual orientation discrimination task (ODT). In prior studies in our laboratory, no practice effects were found during 2 consecutive runs of the ODT, thus in the current investigation, to examine the effects of tDCS, subjects received 10 min of 2 mA occipital tDCS (sham, anode, cathode) between a first and second run of ODT. Surprisingly, subjects’ performance significantly improved in the second run of ODT compared to the first one regardless of the tDCS stimulation type they received (anodal, cathodal, or sham-tDCS). Possible causes for such an improvement could have been due to either a generic “placebo” effect of tDCS (as all subjects received some form of tDCS) or an increased delay period between the two runs of ODT of the current study compared to our previous work (10-min duration required to administer tDCS as opposed to ~ 2 min in previous studies as a “break”). As such, we tested these two possibilities with a subsequent experiment in which subjects received 2-min or 10-min delay between the 2 runs (with no tDCS) or 10 min of sham-tDCS. Only sham-tDCS resulted in improved performance thus these data add to a growing literature suggesting that tDCS has powerful placebo effect that may occur even in the absence of active cortical modulation.
Estimating Unknown Cycles in Geophysical Data
Authors: Shi Xueheng , Gallagher Colin 
Published: November 2019

AbstractExamples of cyclic (periodic) behavior in geophysical data abound. In many cases the primary period is known, such as in daily measurements of rain, temperature, and sea level. However, many time series of measurements contain cycles of unknown or varying length. We consider the problem of estimating the unknown period in a time series. We review the basic methods, compare their performance through a simulation study using observed sea level data, apply them to an astronomical data set, and discuss generalizations of the methods.
Analysis of Ocean Tide‐Induced Magnetic Fields Derived From Oceanic In Situ Observations: Climate Trends and the Remarkable Sensitivity of Shelf Regions
Authors: Petereit Johannes , Saynisch‐Wagner Jan , Irrgang Christopher , Thomas Maik 
Published: November 2019

AbstractTidal motion of oceanic salt water through the ambient geomagnetic field induces periodic electromagnetic field signals. Amplitudes of the induced signals are sensitive to variations in electrical seawater conductivity and, consequently, to changes in oceanic temperature and salinity. In this paper, we computed and analyzed time series of global ocean tide‐induced magnetic field amplitudes. For this purpose, we combined data of global in situ observations of oceanic temperature and salinity fields from 1990–2016 with data of oceanic tidal flow, the geomagnetic field, mantle conductivity, and sediment conductance to derive ocean tide‐induced magnetic field amplitudes. The results were used to compare present day developments in the oceanic climate with two existing climate model scenarios, namely, global oceanic warming and Greenland glacial melting. Model fits of linear and quadratic long‐term trends of the derived magnetic field amplitudes show indications for both scenarios. Also, we find that magnetic field amplitude anomalies caused by oceanic seasonal variability and oceanic climate variations are 10 times larger in shallow ocean regions than in the open ocean. Consequently, changes in the oceanic and therefore the Earth's climate system will be observed first in shelf regions. In other words, climate variations of ocean tide‐induced magnetic field amplitudes are best observed in shallow ocean regions using targeted monitoring techniques.
Strain Rate‐Dependent Hardening‐Softening Characteristics of Gas Hydrate‐Bearing Sediments
Authors: Deusner C. , Gupta S. , Xie X.‐G. , Leung Y. F. , Uchida S. , Kossel E. , Haeckel M. 
Published: November 2019

AbstractThe presence of gas hydrates (GHs) increases the stiffness and strength of marine sediments. In elasto‐plastic constitutive models, it is common to consider GH saturation (Sh) as key internal variable for defining the contribution of GHs to composite soil mechanical behavior. However, the stress‐strain behavior of GH‐bearing sediments (GHBS) also depends on the microscale distribution of GH and on GH‐sediment fabrics. A thorough analysis of GHBS is difficult, because there is no unique relation between Sh and GH morphology. To improve the understanding of stress‐strain behavior of GHBS in terms of established soil models, this study summarizes results from triaxial compression tests with different Sh, pore fluids, effective confining stresses, and strain histories. Our data indicate that the mechanical behavior of GHBS strongly depends on Sh and GH morphology, and also on the strain‐induced alteration of GH‐sediment fabrics. Hardening‐softening characteristics of GHBS are strain rate‐dependent, which suggests that GH‐sediment fabrics dynamically rearrange during plastic yielding events. We hypothesize that rearrangement of GH‐sediment fabrics, through viscous deformation or transient dissociation and reformation of GHs, results in kinematic hardening, suppressed softening, and secondary strength recovery, which could potentially mitigate or counteract large‐strain failure events. For constitutive modeling approaches, we suggest that strain rate‐dependent micromechanical effects from alterations of the GH‐sediment fabrics can be lumped into a nonconstant residual friction parameter. We propose simple empirical evolution functions for the mechanical properties and calibrate the model parameters against the experimental data.
Solar Wind Interaction With Jupiter's Magnetosphere: A Statistical Study of Galileo In Situ Data and Modeled Upstream Solar Wind Conditions
Authors: Vogt Marissa F. , Gyalay Szilard , Kronberg Elena A. , Bunce Emma J. , Kurth William S. , Zieger Bertalan , Tao Chihiro 
Published: November 2019

AbstractJupiter's magnetosphere is often said to be rotationally driven, with strong centrifugal stresses due to large spatial scales and a rapid planetary rotation period. While the solar wind is therefore expected to have a relatively small influence on Jupiter's magnetosphere and aurora, there is considerable observational evidence that the solar wind does affect the magnetopause standoff distance, auroral radio emissions, and the ultraviolet auroral position and brightness. We report on the results of a comprehensive, quantitative study of the influence of the solar wind dynamic pressure on magnetospheric data sets measured by the Galileo mission (1996–2003). Using model predictions of the solar wind conditions near Jupiter calculated by propagating measurements made near the Earth, we have established how predicted changes in the solar wind affect the magnitude and direction of the magnetic field in the magnetosphere, the hectometric auroral radio emissions, and energetic particles in Jupiter's magnetosphere. We find that increases in the solar wind dynamic pressure are statistically associated with magnetospheric compression events but that tail reconnection and plasmoid release is most likely driven internally by the Vasyliunas cycle. We find no link between solar wind conditions and the occurrence of quasiperiodic modulations in the magnetosphere. Overall, we conclude that activity in Jupiter's magnetosphere is both internally and solar wind driven. Finally, we examine the effects of solar wind‐induced magnetospheric compressions on Jupiter's auroral brightness and mapping, finding that a solar wind compression could shift the auroral mapping of a given point in the magnetosphere by ~3° on average.
Pump Power Effects on Second Harmonic Stimulated Electromagnetic Emissions During Ionosphere Heating
Authors: Yellu A. D. , Scales W. A. , Mahmoudian A. , Bernhardt P. A. , Siefring C. L. , Briczinski S. , Nossa E. , McCarrick M. J. 
Published: November 2019

AbstractDue to the potential for new diagnostic capabilities, there has been renewed interest in the generation of ionospheric stimulated electromagnetic emissions (SEEs) near the second harmonic of the pump frequency (ω0), a process known as second harmonic generation (SHG). Observations of SHG during experiments at the High Frequency Active Auroral Research Program facility in which ω0 was stepped near the third harmonic of the electron gyrofrequency, 3ωce, and the transmit power linearly increased over the heating cycle at each ω0, were reported recently. A key observation was the linkage between SEEs within ±30 Hz of ω0, due to stimulated Brillouin scatter, and within ±30 Hz of 2ω0. This current work reports further High Frequency Active Auroral Research Program observations that compare the time evolution of SEEs including SHG under the following two transmit power conditions (I) linear power ramp (II) maximum available power (2.8 MW). During these experiments, ω0 was stepped near 3ωce and also 2ωce. The results show that SEEs within ±100 Hz of ω0 and 2ω0 are both suppressed within a few seconds when the ionosphere is irradiated with the maximum available power. These SEEs appear to be suppressed before the onset of field‐aligned irregularities at the upper hybrid layer which is not in line with previous reports. Thus, other mechanisms, which are discussed, could possibly be responsible for the observed suppression of stimulated Brillouin scatter and SHG. Some preliminary diagnostics are derived from the SHG spectra temporal evolution by leveraging concepts from the field of laser plasma interactions.
MELISSA: System description and spectral features of pre‐ and post‐midnight F‐region echoes
Authors: Rodrigues Fabiano S. , Zhan Weijia , Milla Marco A. , Fejer Bela G. , de Paula Eurico R. , Neto Acacio C. , Santos Angela M. , Batista Inez S. 
Published: November 2019

AbstractMost of the low‐latitude ionospheric radar observations in South America come from the Jicamarca Radio Observatory, located in the western longitude sector (∼75°W). The deployment of the 30 MHz FAPESP‐Clemson‐INPE (FCI) coherent backscatter radar in the magnetic equatorial site of São Luis, Brazil, in 2001 allowed observations to be made in the eastern sector (∼45°W). However, despite being operational for several years (2001–2012), FCI only made observations during daytime and pre‐midnight hours, with a few exceptions. Here, we describe an upgraded system that replaced the FCI radar and present results of full‐night F‐region observations. This radar is referred to as Measurements of Equatorial and Low‐latitude Ionospheric irregularities over São Luís, South America (MELISSA), and made observations between March 2014 and December 2018. We present results of our analyses of pre‐ and post‐midnight F‐region echoes with focus on the spectral features of post‐midnight echoes and how they compare to spectra of echoes observed in the post‐sunset sector. The radar observations indicate that post‐midnight F‐region irregularities were generated locally and were not a result of “fossil” structures generated much earlier in time (in other longitude sectors) and that drifted into the radar field‐of‐view. This also includes cases where the echoes are weak and that would be associated with decaying equatorial spread F (ESF) structures. Collocated digisonde observations show modest but noticeable F‐region apparent uplifts prior to post‐midnight ESF events. We associate the equatorial uplifts with disturbed dynamo effects and with destabilizing F‐region conditions leading to ESF development.
Magma Oscillations in a Conduit‐Reservoir System, Application to Very Long Period (VLP) Seismicity at Basaltic Volcanoes: 1. Theory
Authors: Liang Chao , Karlstrom Leif , Dunham Eric M. 
Published: November 2019

AbstractVery long period (VLP, 2–100 s) seismic signals at basaltic volcanoes like Kilauea, Hawai‘i, and Mount Erebus, Antarctica are likely from resonant oscillations of magma within the shallow plumbing system. The system consists of conduits connected to cracks (dikes and sills) or reservoirs of other shapes. A quantitative understanding of wave propagation and resonance in a coupled conduit‐crack system is required to interpret observations. In this work, we idealize the system as an axisymmetric conduit coupled to a tabular crack, accounting for fluid inertia, compressibility, and viscosity, buoyancy, and crack wall elasticity. We perform time domain simulations and eigenmode analyses of the governing equations, linearized about a rest state. The fundamental mode or conduit‐reservoir mode reflects the balance of conduit magma inertia with buoyancy (and, for small cracks, crack wall elasticity). Magma oscillates in an effectively incompressible manner within the conduit, deflating and inflating the crack, which couples to the surrounding solid to produce observable surface displacements. For sufficiently low viscosity magmas, viscous effects are confined to boundary layers. Shorter period modes are primarily reverberating crack waves with negligible coupling to the conduit. Finally, we introduce an approximate reduced model for the conduit‐reservoir mode, which can also handle more general reservoir geometries (e.g., spherical chambers). The reduced model connects the observable VLP period and quality factor to two uniquely constrained parameters: the inviscid oscillation period T0 and the viscous diffusion time τvis across the conduit radius. Our models can be extended to study the seismic response of more complex magmatic systems.
Virtual Tide Gauges for Predicting Relative Sea Level Rise
Authors: Hawkins Rhys , Husson Laurent , Choblet Gaël , Bodin Thomas , Pfeffer Julia 
Published: November 2019

AbstractWe present a Bayesian method to map contemporary rates of relative sea level change using a joint inversion of vertical trends from tide gauges, GPS time series, and satellite radar altimetry measurements. Tide gauge measurements constrain rates of relative sea level change on decadal to secular time scales at a few hundred sites sparsely distributed along coastlines. Predicting the rates of relative sea level change from historical tide gauge measurements is difficult due to the paucity and uneven distribution of sites with high quality records. Since the late twentieth century, deployments of GPS stations have enabled accurate determination of the rates of vertical land motion. A series of satellite radar altimetry missions provide continuous and global monitoring of geocentric sea level changes since the launch of TOPEX/Poseidon in 1992. By combining these three observations types into a single Bayesian inversion, we construct continuous maps of rates of relative sea level change, geocentric sea level change, and vertical land motion assuming linear trends, with robust estimates of uncertainties at regional scales. Cross‐validation tests show that reliable predictions of relative sea level changes are still provided where only GPS and satellite altimetry data are used, suggesting this method is viable for studying potential sea level risk for communities where historical tide gauge data are not available. Our results provide spatially and temporally consistent estimates of the various contributions to relative sea level changes.
Seasonal Variation in Sediment Delivery Across the Bay‐Marsh Interface of an Estuarine Salt Marsh
Authors: Lacy Jessica R. , Foster‐Martinez Madeline R. , Allen Rachel M. , Ferner Matthew C. , Callaway John C. 
Published: November 2019

AbstractSediment transport across bay‐marsh interfaces depends on wave energy, vegetation, and marsh‐edge morphology and varies over a range of timescales. We investigated these dynamics in a tidal salt marsh with a gently sloped, vegetated edge adjacent to northern San Francisco Bay. Spartina foliosa (cordgrass) inhabits the lower marsh and Salicornia pacifica (pickleweed) predominates on the marsh plain. We measured suspended‐sediment concentration (SSC) and hydrodynamics in bay shallows and along a 100‐m cross‐shore transect in the marsh, during winter and summer. Four‐year averaged accretion measured with marker‐horizon plots was twice as great along the marsh transect as adjacent to a tidal creek, 50 m from the bay. We estimated deposition and trapping efficiency from the time series data to assess its variation with season and wave energy. At high tide the transition zone (between cordgrass and pickleweed) was usually erosional, the pickleweed zone was depositional, and both erosion and deposition increased with wave energy, as did the landward position of maximum deposition. Erosion from the transition zone accounted for approximately one third of the sediment flux into the pickleweed. In the pickleweed zone, SSC, the difference between flood‐ and ebb‐tide SSC, and trapping efficiency were greater in summer than winter for comparable wave conditions, which we attribute to increased sediment trapping by dense summer cordgrass. Moderate waves in summer (46%) accounted for more annual accretion in the pickleweed zone than larger waves in winter (28%), although the contribution of winter storms was diminished by the dry winter during the study.
Vertical Profiling of Aerosols With a Combined Raman‐Elastic Backscatter Lidar in the Remote Southern Ocean Marine Boundary Layer (43–66°S, 132–150°E)
Authors: Alexander S. P. , Protat A. 
Published: November 2019

AbstractA combined Raman‐elastic backscatter lidar, deployed aboard the research vessel RV Investigator for two campaigns for a total of 10 week's ship time, is used to quantify the properties of aerosols within the remote Southern Ocean marine boundary layer between Australia and Antarctica in the region 43–66°S and 132–150°E. Eleven Raman case studies are identified for analyses. Particle linear depolarization ratio and height‐resolved lidar ratio S, calculated from the Raman retrievals, are consistent with values expected within the surface mixed layer for clean marine conditions. We determine S=(19±7) sr across the Southern Ocean with the Raman lidar observations. Aerosol optical properties in the marine boundary layer close to Tasmania (43°S) sometimes indicate the influence of continental air masses. Aerosol optical depth at 355 nm calculated from the retrieved Raman extinction profiles within the surface mixed layer is τ=(0.11±0.04). Boundary‐layer height is determined from the lidar observations and decreases from (0.9±0.4) km north of the Polar Front (around 55°S) to (0.7±0.2) km south of the Polar Front. Dried sea salt is present above the midlatitude ocean in the dehumidified decoupled layer in different synoptic‐scale atmospheric conditions including beneath a high‐pressure system and in a post‐frontal air mass. At all latitudes across the Southern Ocean, large aerosol backscatter, low depolarization ratio, and high relative humidity indicate the presence of sea salt droplets within the well‐mixed near‐surface layer.
On the Causal Relationship Between the Moist Diabatic Circulation and Cloud Rapid Adjustment to Increasing CO2
Authors: Dinh T. , Fueglistaler S. 
Published: November 2019

AbstractGeneral circulation models predict that clouds in the atmosphere rapidly adjust to the radiative perturbation of an abrupt increase in atmospheric CO2 concentration on a short time scale of about 10 days. This rapid adjustment consists of an increase of clouds in the boundary layer and a decrease of clouds in the free troposphere. Our focus is the mechanism for the decrease of clouds in the free troposphere, which is the dominating component of cloud rapid adjustment in most general circulation models. We propose that the decrease in clouds in the free troposphere arises from the causal relationship between the moist diabatic circulation and the production of condensates that forms clouds in moist processes. As CO2 concentration increases, tropospheric radiative cooling is reduced, resulting in weakening of the moist diabatic circulation and a decrease in precipitation. As the hydrologic cycle weakens and the moist processes involving phase change of water vapor to form the condensates in the atmosphere lessen, the mass of cloud condensates decreases. This decrease in cloud condensates can be predicted from the decrease in the radiative subsidence mass flux, which is a metric for the strength of the moist diabatic circulation in the free troposphere.