bluuebunny/crossref_metadata_2025_split huggingface dataset:
INITIAL IMPROVEMENT OF THE HYBRID ACCELERATED GRADIENT DESCENT PROCESS
Authors: PANIĆ STEFAN , PETROVIĆ MILENA J. , CAREVIĆ MIROSLAVA MIHAJLOV 
Published: August 2018

We improve the convergence properties of the iterative scheme for solving unconstrained optimisation problems introduced in Petrovic et al. [‘Hybridization of accelerated gradient descent method’, Numer. Algorithms (2017), doi:10.1007/s11075-017-0460-4] by optimising the value of the initial step length parameter in the backtracking line search procedure. We prove the validity of the algorithm and illustrate its advantages by numerical experiments and comparisons.
Effects of prebiotic inulin-type fructans on blood metabolite and hormone concentrations and faecal microbiota and metabolites in overweight dogs
Authors: Alexander Celeste , Cross Tzu-Wen L. , Devendran Saravanan , Neumer Franka , Theis Stephan , Ridlon Jason M. , Suchodolski Jan S. , de Godoy Maria R. C. , Swanson Kelly S. 
Published: August 2018

AbstractBecause obesity is associated with many co-morbidities, including diabetes mellitus, this study evaluated the second-meal effect of a commercial prebiotic, inulin-type fructans, and the effects of the prebiotic on faecal microbiota, metabolites and bile acids (BA). Nine overweight beagles were used in a replicated 3×3 Latin square design to test a non-prebiotic control (cellulose) against a low (equivalent to 0·5 % diet) and high dose (equivalent to 1·0 % diet) of prebiotic over 14-d treatments. All dogs were fed the same diet twice daily, with treatments provided orally via gelatin capsules before meals. On days 13 or 14 of each period, fresh faecal samples were collected, dogs were fed at 08.00 hours and then challenged with 1 g/kg body weight of maltodextrin in place of the 16.00 hours meal. Repeated blood samples were analysed for glucose and hormone concentrations to determine postprandial incremental AUC (IAUC) data. Baseline glucose, insulin and active glucagon-like peptide-1 levels were similar between all groups (P>0·10). Glucose and insulin IAUC after glucose challenge appeared lower following the high dose, but did not reach statistical relevance. Prebiotic intervention resulted in an increase in relative abundance of some Firmicutes and a decrease in the relative abundance of some Proteobacteria. Individual and total faecal SCFA were significantly increased (P<0·05) following prebiotic supplementation. Total concentration of excreted faecal BA tended to increase in dogs fed the prebiotic (P=0·06). Our results indicate that higher doses of inulin-type prebiotics may serve as modulators of gut microbiota, metabolites and BA pool in overweight dogs.
Modeling and trajectory tracking control of a two-wheeled mobile robot: Gibbs–Appell and prediction-based approaches
Authors: Mirzaeinejad Hossein , Shafei Ali Mohammad 
Published: August 2018

SUMMARYThis study deals with the problem of trajectory tracking of wheeled mobile robots (WMR's) under non-holonomic constraints and in the presence of model uncertainties. To solve this problem, the kinematic and dynamic models of a WMR are first derived by applying the recursive Gibbs–Appell method. Then, new kinematics- and dynamics-based multivariable controllers are analytically developed by using the predictive control approach. The control laws are optimally derived by minimizing a pointwise quadratic cost function for the predicted tracking errors of the WMR. The main feature of the obtained closed-form control laws is that online optimization is not needed for their implementation. The prediction time, as a free parameter in the control laws, makes it possible to achieve a compromise between tracking accuracy and implementable control inputs. Finally, the performance of the proposed controller is compared with that of a sliding mode controller, reported in the literature, through simulations of some trajectory tracking maneuvers.
Multi-robot system optimization based on redundant serial spherical mechanism for robotic minimally invasive surgery
Authors: Nelson C. A. , Laribi M. A. , Zeghloul S. 
Published: August 2018

SUMMARYSerial spherical linkages have been used in the design of a number of robots for minimally invasive surgery, in order to mechanically constrain the surgical instrument with respect to the incision. However, the typical serial spherical mechanism suffers from conflicting design objectives, resulting in an unsuitable compromise between avoiding collision with the patient and producing good kinematic and workspace characteristics. In this paper, we propose a multi-robot system composed of two redundant serial spherical linkages to achieve this purpose. A multi-objective optimization for achieving the aforementioned design goals is presented first for a single redundant robot and then for a multi-robot system. The problem of mounting multiple robots on the operating table as well as the way cooperative actions can be performed is addressed. The sensitivity of each optimal solution (single-robot and multi-robot) to uncertainties in the design parameters is investigated.
Abstract allocation as a unified approach to polyvariance in control-flow analyses
Authors: GILRAY THOMAS , ADAMS MICHAEL D. , MIGHT MATTHEW 
Published: August 2018

AbstractIn higher order settings, control-flow analysis aims to model the propagation of both data and control by finitely approximating program behaviors across all possible executions. The polyvariance of an analysis describes the number of distinct abstract representations, or variants, for each syntactic entity (e.g., functions, variables, or intermediate expressions). Monovariance, one of the most basic forms of polyvariance, maintains only a single abstract representation for each variable or expression. Other polyvariant strategies allow a greater number of distinct abstractions and increase analysis complexity with the aim of increasing analysis precision. For example,k-call sensitivity distinguishes flows by the most recentkcall sites,k-object sensitivity by a history of allocation points, and argument sensitivity by a tuple of dynamic argument types. From this perspective, even a concrete operational semantics may be thought of as an unboundedly polyvariant analysis. In this paper, we develop a unified methodology that fully captures this design space. It is easily tunable and guarantees soundness regardless of how tuned. We accomplish this by extending the method of abstracting abstract machines, a systematic approach to abstract interpretation of operational abstract-machine semantics. Our approach permits arbitrary instrumentation of the underlying analysis and arbitrary tuning of an abstract-allocation function. We show that the design space of abstract allocators both unifies and generalizes existing notions of polyvariance. Simple changes to the behavior of this function recapitulate classic styles of analysis and yield novel combinations and variants.
Ventricular tachycardia in a 16-year-old boy with primary hyperparathyroidism
Authors: Marčinković Nedo , Dilber Daniel , Velagić Vedran 
Published: August 2018

AbstractWe report a case of primary hyperparathyroidism with hypercalcaemia in a 16-year-old boy who had spontaneous attack of ventricular tachycardia. To our knowledge, presentation of ventricular tachycardia caused by primary hyperparathyroidism in such a young patient has not been reported in medical literature so far.
Self-Reference Effect and Self-Reference Recollection Effect for Trait Adjectives in Amnestic Mild Cognitive Impairment
Authors: Carson Nicole , Rosenbaum R. Shayna , Moscovitch Morris , Murphy Kelly J. 
Published: August 2018

AbstractObjectives:The self-reference effect (SRE), enhanced memory for self-related information, has been studied in healthy young and older adults but has had little investigation in people with age-related memory disorders, such as amnestic mild cognitive impairment (aMCI). Self-referential encoding may help to improve episodic memory in aMCI. Additionally, self-referential processing has been shown to benefitrecollection, the vivid re-experiencing of past events, a phenomenon that has been termed theself-reference recollection effect(SRRE; Conway & Dewhurst, 1995). Furthermore, it remains unclear whether the valence of stimuli influences the appearance of the SRE and SRRE.Methods:The current study investigated the SRE and SRRE for trait adjective words in 20 individuals with aMCI and 30 healthy older adult controls. Ninety trait adjective words were allocated to self-reference, semantic, or structural encoding conditions; memory was later tested using a recognition test.Results:While healthy older adults showed a SRE, individuals with aMCI did not benefit from self-referential encoding over and above that of semantic encoding (an effect of “deep encoding”). A similar pattern was apparent for the SRRE; healthy controls showed enhanced recollection for words encoded in the self-reference condition, while the aMCI group did not show specific benefit to recollection for self-referenced over semantically encoded items. No effects of valence were found.Conclusions:These results indicate that while memory for trait adjective words can be improved in aMCI with deep encoding strategies (whether self-reference or semantic), self-referencing does not provide an additional benefit. (JINS, 2018,24, 821–832)
From status inconsistency to revisionism: Russian foreign policy after color revolutions
Authors: Mazloomi Esmaeil , Yeoh Emile Kok-Kheng , Karim Mohd Aminul 
Published: August 2018

AbstractThis paper delves into the shifts in the foreign policy of Russia, considering what has determined Russia's grand strategy orientation after the collapse of the Soviet Union. It also attempts to offer an explanation of why Russia becomes discounted with the ‘constitutive and normative structure’, and how its foreign policy shifted toward the anti-status quo orientation, especially after the color revolutions. The main purpose of this paper is to explain the shift in Russia's foreign policy, from the search for the ‘greatpowerness’ status via different enhancement strategies in light of status quo in the ‘revolutionary decade’, to revisionism after the color revolutions in Commonwealth of Independent States region (2003–2005). To substantiate this, the study uses process-tracing and document analysis to show the changes in Russia's foreign policy. As demonstrated in this paper, power rendered is unable of directing or disinclined to direct its policies toward status quo, due to internal effects of perceived ‘status immobility’ resulting from the failure of several status enhancement strategies. Accordingly, the shift in Russia's foreign policy was a result of changing the Russian perception from status inconsistency to status immobility.
Wideband dual-polarized Vivaldi antenna with improved balun feed
Authors: Song Lizhong , Zhou Huiyuan 
Published: August 2018

AbstractThe paper researches a kind of wideband dual-polarized Vivaldi antenna with improved balun feed which consists of slot line and two bent coplanar strip lines. The whole of antenna structure is composed of two orthogonal Vivaldi antenna elements, and the mode of feeding adopts electromagnetic coupling from micro-strip line to slot line. The improved balun can avoid the intersection of transmission lines, reduce the size, and simplify the assembly. The electromagnetic simulation and optimization design of proposed antenna are carried out by using electromagnetic simulation software, CST. Simulation results show that the isolation between two polarized ports is more than 15 dB within working frequency range of 2–3.5 GHz and VSWRs of two ports are lower than 2.5 at the range of 2–3.5 GHz. The designed antenna is fabricated and measured. The measured results indicate that the designed antenna achieves anticipated patterns and feasible design of the dual-polarized Vivaldi antenna. The dual-polarized Vivaldi antenna with improved balun feed is suitable for some application fields, such as passive electronic reconnaissance, passive radar, and wideband communication and detection.
On the Quasi‐linear Saturation of the Parallel Proton Firehose Instability Using a Full‐f Approach
Authors: Astfalk Patrick , Jenko Frank 
Published: August 2018

AbstractA classic example for the application of quasi‐linear theory to electromagnetic wave‐particle interactions, the saturation of the parallel proton firehose instability, is usually considered in the long‐wavelength approximation although for
this instability is dominated by anomalous cyclotron resonance, which invalidates a macroscopic treatment (Gary et al., 1998, https://doi.org/10.1029/98JA01174). To relax the long‐wavelength approximation, Seough et al. (2015, https://doi.org/10.1063/1.4905230) solved the microscopic weak turbulence kinetic equation to model the temperature anisotropy reduction of the firehose also in the resonant regime. However, the employed moment‐kinetic approach assumes the preservation of the initially bi‐Maxwellian shape of the underlying proton velocity distribution throughout the saturation process, leading to poor results for low β∥,p. In this work, we lift the limitations of the moment‐kinetic approach and we demonstrate that allowing for distribution deformation due to anomalous cyclotron‐resonant scattering greatly improves the predictions of the kinetic quasi‐linear model except for cases of very strong firehose growth. We conclude that quasi‐linear theory can be a valid model for studying the parallel firehose saturation even in the strongly cyclotron‐resonant regime as long as the initial temperature anisotropy is not too large.
Growth of Self‐Assembling Tubular Structures of Magnesium Oxy/Hydroxide and Silicate Related With Seafloor Hydrothermal Systems Driven by Serpentinization
Authors: Sainz‐Díaz C. Ignacio , Escamilla‐Roa Elizabeth , Cartwright Julyan H. E. 
Published: August 2018

AbstractTubular structures self‐assemble from precipitating magnesium salts under the chemical garden chemobrionic growth process. Two experimental procedures, the dissolution of magnesium salt pellets and the injection of magnesium salt solutions into silicate solutions, were explored to reproduce in the laboratory the geochemical conditions under which similar structures may form from mineral‐rich fluids at some seafloor hydrothermal vents driven by serpentinization. X‐ray diffraction and Raman microspectroscopy applied to the materials formed indicated the presence of layers of magnesium silicate and magnesium oxide/hydroxide. Quantum mechanical calculations based on density functional theory were performed on models of hydrated magnesium silicate surfaces and related minerals to explain the Raman spectroscopy results. We examine the precipitate morphology, chemical structure, and crystal or mineral structure in our experiments and how these change with the reaction conditions. This is a fascinating example in geochemistry of a self‐organizing nonequilibrium process that creates complex structures.
First Daily Mapping of Surface Moisture from Cellular Network Data and Comparison with Both Observations/ECMWF Product
Authors: Alpert P. , Rubin Y. 
Published: August 2018

AbstractAir‐moisture maps were generated based on commercial microwave links data over N. Israel and compared for the first time to European Centre for Medium‐Range Weather Forecasts (ECMWF) ERA‐Interim maps for April 2017. Several skill scores of the different maps were calculated against the observed humidity from 39 weather stations. High correlations range, 0.75–0.9, were found between the new links' humidity fields and the stations. The numbers of best correlated links are found to be higher compared to ECMWF, that is, 31 stations versus 8. Also, in the measure of standard deviation the links performed better, 38 versus 1. However, for the mean humidity, the ECMWF is doing better, that is 14/25 for links/ECMWF. The links' humidity thus provides a more accurate picture of the observed moisture as compared to current weather prediction product. Consequently, the high‐resolution humidity fields obtained from the commercial microwave link seem to have the potential to improve future forecasting of precipitation.
Imaging of Lithospheric Structure Beneath Jeju Volcanic Island by Teleseismic Traveltime Tomography
Authors: Song Jung‐Hun , Kim Seongryong , Rhie Junkee , Lee Sang‐Hyun , Kim YoungHee , Kang Tae‐Seob 
Published: August 2018

AbstractJeju Island (JI) is an intraplate volcanic field located at the continental margin of Northeast Asia. This volcanic island has been formed by multiple eruptions from the Pleistocene to the Holocene (~3.7 ka), which have yielded hundreds of monogenetic volcanic cones and a central basaltic shield. To understand the volcanic structures and mechanism beneath JI, we deployed 20 broadband temporary seismometers across the island for over two years (October 2013 to November 2015). We investigated the crustal and upper mantle structures in JI for the first time using the gathered data. Through teleseismic traveltime tomography, we obtained images of the lithospheric structure related to the volcanic system. A major finding was the identification of a prominent low‐velocity anomaly (<−0.3 km/s in P wave velocity relative to the surrounding high‐velocity region) beneath the summit of the central shield volcano at greater depths (50–60 km), which separates into low‐velocity zones at shallower depths (10–45 km). Based on previous geological observations, the anomalies were interpreted as a magmatic system, potentially with partial melting. Moreover, relatively high velocity zones were consistently imaged to the north, east, and west of the island, indicating relatively thick lithospheric structures at the southern margin of the continental lithosphere beneath the Korean Peninsula. Based on the geometries of the imaged structures, we suggest that a focused decompressional melting at sublithospheric depths and complex magma interactions within the lithosphere resulted in the characteristics of JI volcanism as intraplate magmatic activities that are isolated in space and confined in time.
Forecasting the Arrival Time of Coronal Mass Ejections: Analysis of the CCMC CME Scoreboard
Authors: Riley Pete , Mays M. Leila , Andries Jesse , Amerstorfer Tanja , Biesecker Douglas , Delouille Veronique , Dumbović Mateja , Feng Xueshang , Henley Edmund , Linker Jon A. , Möstl Christian , Nuñez Marlon , Pizzo Vic , Temmer Manuela , Tobiska W. K. , Verbeke C. , West Matthew J , Zhao Xinhua 
Published: August 2018

AbstractAccurate forecasting of the properties of coronal mass ejections (CMEs) as they approach Earth is now recognized as an important strategic objective for both NOAA and NASA. The time of arrival of such events is a key parameter, one that had been anticipated to be relatively straightforward to constrain. In this study, we analyze forecasts submitted to the Community Coordinated Modeling Center at NASA's Goddard Space Flight Center over the last 6 years to answer the following questions: (1) How well do these models forecast the arrival time of CME‐driven shocks? (2) What are the uncertainties associated with these forecasts? (3) Which model(s) perform best? (4) Have the models become more accurate during the past 6 years? We analyze all forecasts made by 32 models from 2013 through mid‐2018, and additionally focus on 28 events, all of which were forecasted by six models. We find that the models are generally able to predict CME‐shock arrival times—in an average sense—to within ±10 hr, but with standard deviations often exceeding 20 hr. The best performers, on the other hand, maintained a mean error (bias) of −1 hr, a mean absolute error of 13 hr, and a precision (standard deviation) of 15 hr. Finally, there is no evidence that the forecasts have become more accurate during this interval. We discuss the intrinsic simplifications of the various models analyzed, the limitations of this investigation, and suggest possible paths to improve these forecasts in the future.
Approaches for Estimating Soil Water Retention Curves at Various Bulk Densities With the Extended Van Genuchten Model
Authors: Tian Zhengchao , Gao Weida , Kool Dilia , Ren Tusheng , Horton Robert , Heitman Joshua L. 
Published: August 2018

AbstractSoil bulk density (ρb) variations influence soil hydraulic properties, such as the water retention curve (WRC), but they are usually ignored in soil water simulation models. We extend the van Genuchten WRC model parameters to account for ρb variations using a series of empirical expressions. WRC measurements made on eight soils with various ρb, and textures are used to calibrate these ρb‐related empirical equations. Accordingly, two approaches are developed to estimate WRCs of soils at various ρb. Another eight soils with a wide range of ρb and textures are used to evaluate the accuracy of the new approaches. Approach 1 estimates WRCs for each soil at various ρb using a WRC measurement made at a reference ρb and the soil texture fractions. This approach gives reasonable WRC estimates for the eight validation soils, with an average root‐mean‐square error (RMSE) of 0.025 m3/m3 and an average determination coefficient (R2) of 0.94. For Approach 2, a WRC measurement made at a reference ρb and one additional water content‐matric potential value measured at a different ρb value are used, which produces WRC estimates with an average RMSE of 0.017 m3/m3 and an average R2 of 0.97. The methodology used in Approach 2 is also applied to the Brooks and Corey WRC model to obtain accurate and precise WRC estimates. The proposed approaches have the potential to be incorporated into simulation models for estimating soil hydraulic properties that are affected by transient and variable ρb.
Identification of Pollutant Source for Super‐Diffusion in Aquifers and Rivers with Bounded Domains
Authors: Zhang Yong , Sun HongGuang , Neupauer Roseanna M. , Straka Peter , Kelly James F. , Lu Bingqing , Zheng Chunmiao 
Published: August 2018

AbstractBackward models for super‐diffusion in infinite domains have been developed to identify pollutant sources, while backward models for non‐Fickian diffusion in bounded domains remain unknown. To restrict possible source locations and improve the accuracy of backward probabilities, this technical note develops the backward model for super‐diffusion governed by the fractional‐divergence advection‐dispersion equation (FD‐ADE) in bounded domains. The resultant backward model is the fractional‐flux advection‐dispersion equation (FF‐ADE) with modified boundary conditions. In particular, the Dirichlet boundary condition in the forward FD‐ADE becomes a spatial‐nonlocal sink term in the backward FF‐ADE (to account for preferential flow), while the nonlocal, non‐zero‐value Neumann (or Robin) boundary condition in the forward FD‐ADE switches to the zero‐value Robin (or Neumann) boundary condition in the backward FF‐ADE (to eliminate pollutant source outside the domain). Field applications show that the backward location probability density function can approximate the point source location in a natural river or fluvial aquifer. The impact of reflective/absorbing boundaries and the upstream boundary location on the backward probability density function is also discussed.