bluuebunny/crossref_metadata_2025_split huggingface dataset:
A monotone combination scheme of diffusion equations on polygonal meshes
Authors: Zhao Fei , Sheng Zhiqiang , Yuan Guangwei 
Published: March 2020

AbstractWe present a novel monotone scheme which is a combination of linear scheme and nonlinear monotone scheme for solving diffusion problems on general polygonal meshes. It will be called as a combination scheme and consists of two steps. Firstly, a second‐order accurate linear scheme is used to obtain an approximate solution. Secondly, a nonlinear monotone scheme is used to solve the diffusion equation, where the unknowns in the nonlinear coefficient of the nonlinear monotone scheme are taken as the approximate solution of the linear scheme above, i.e., a linearized monotone scheme is obtained. So the combination scheme does not require nonlinear iterations for solving linear diffusion problems, moreover, it benefits from the accuracy and efficiency of the linear scheme, as well as the monotonicity of nonlinear monotone scheme. We also analyze some properties satisfied by the combination scheme, such as conservation, stability, monotonicity and convergence. Numerical results are presented to show the performance of the monotone combination scheme on distorted meshes, especially some numerical comparisons among our combination scheme with some existing linear and nonlinear monotone schemes are given.
The Study of Irregular Migration
Authors: Echeverría Gabriel 
Published: March 2020

AbstractThe study of irregular migration as a specific social phenomenon took off during the 70s in the US. Since then, the academic interest has continually grown and spread, first to Europe and, in the last years, to other regions worldwide. This interest can certainly be related to the increasing attention paid to the study of migrations more in general (Castles & Miller, 1993). The trend can be linked to those broad and complex social and economic changes, often subsumed under the concept of globalization. The specific focus on irregular migration, though gaining momentum throughout the 1980s, reached preeminent attention in the 1990s. On both sides of the Atlantic, the explosion of the so-called “migration crisis” (Zolberg & Benda, 2001) and the emergence of irregular migration as a widespread social fact raised the attention of public opinion and academics alike. Moreover, in recent years, what seemed at first to be an issue concerning only the high-income regions of the planet, now involves also medium and low-income ones, making irregular migration a truly global structural phenomenon (Cvajner & Sciortino, 2010a; Düvell, 2006).
Understanding Irregular Migration Through a Social Systems Perspective
Authors: Echeverría Gabriel 
Published: March 2020

AbstractThe numerous problems and limitations that have affected the theoretical understanding of irregular migration cannot be simply related to a lack of empirical data or to the complexity of the phenomenon. Rather, they reveal important obstacles épistémologiques (Luhmann, 2007, p. 11) and conceptual problems that demand a reconsideration of many of the theoretical assumptions that have been generally used. Both the lack of differentiated analysis and the use of mono-causal explanations, which have been indicated as the most evident symptoms of theoretical ineffectiveness, have been linked to three broader and deeper causes. In particular: (a) a limited and often misguiding conception of society, usually subsumed within the concept of state; (b) the simplistic understanding of the different social actors and their interests; (c) the deterministic, cause-effect interpretation of social interactions. The extent and complexity of these issues, that evidently surpass the confines of the so-called migration studies, require a more general reflection on contemporary society and its functioning. From this perspective, international migration and, in our case, irregular migration, need to be considered as part and parcel, both products and determinants, of the broader social processes and structures. A satisfactory understanding of them can only be achieved in connection with a more general interpretation of contemporary society, one that critically reviews many important assumptions and preconceptions that have been imposed by the effects of methodological nationalism.
Methodological Note
Authors: Echeverría Gabriel 
Published: March 2020

AbstractThe second part of the book will present the results of an empirical study of the experience of Ecuadorian irregular migrants in the cities of Amsterdam and Madrid. While the general overview of the methodological conceptualization that is the backbone of the whole research work has already been outlined in the introduction, in this brief chapter the focus will be centred on the specific methodological issues concerning the empirical study.
Ecuadorian Migration in Amsterdam and Madrid: The Structural Contexts
Authors: Echeverría Gabriel 
Published: March 2020

AbstractThe scope of this chapter is to outline the main characteristics of the two contexts that were the scenario of the phenomenon that is the object of this book. The analysis will centre on those structural features of the cities of Amsterdam and Madrid and, more in general, of the Netherlands and Spain, that may have had an influence on the experience of Ecuadorian irregular migrants.
Steps Towards a Systemic Theory of Irregular Migration
Authors: Echeverría Gabriel 
Published: March 2020

AbstractIn this last, conclusive chapter, the main question at the origin of all the research work in this book – how can irregular migration be explained? – will be the focus of the discussion. The chapter is divided into two parts. In the first part, the aforementioned question will be addressed in relation to cases of the empirical study and it will then be reframed in the following terms: how can Ecuadorian irregular migration in Amsterdam and Madrid be explained? To answer this question, the efficacy of the “classic” theories, discussed in the Chap. 3, will be firstly tested. As it will be pointed out, many of the limitations which emerged in the theoretical discussion will become evident also when those theories are applied to concrete cases. Then, a systemic explanation, based on the theoretical approach developed in Chap. 4, will be proposed as a possible alternative.
The partonic structure of the electron at the next-to-leading logarithmic accuracy in QED
Authors: Bertone V. , Cacciari M. , Frixione S. , Stagnitto G. 
Published: March 2020

Abstract
By working in QED, we obtain the electron, positron, and photon Parton Distribution Functions (PDFs) of the unpolarised electron at the next-to-leading logarithmic accuracy. The PDFs account for all of the universal effects of initial-state collinear origin, and are key ingredients in the calculations of cross sections in the so-called structure- function approach. We present both numerical and analytical results, and show that they agree extremely well with each other. The analytical predictions are defined by means of an additive formula that matches a large-z solution that includes all orders in the QED coupling constant α, with a small- and intermediate-z solution that includes terms up to $$ \mathcal{O} $$
O
(α3).
Quasi-integrable KdV models, towers of infinite number of anomalous charges and soliton collisions
Authors: Blas H. , Ochoa R. , Suarez D. 
Published: March 2020

Abstract
We found, through analytical and numerical methods, new towers of infinite number of asymptotically conserved charges for deformations of the Korteweg-de Vries equation (KdV). It is shown analytically that the standard KdV also exhibits some towers of infinite number of anomalous charges, and that their relevant anomalies vanish for N −soliton solution. Some deformations of the KdV model are performed through the Riccati-type pseudo-potential approach, and infinite number of exact non-local conservation laws is provided using a linear formulation of the deformed model. In order to check the degrees of modifications of the charges around the soliton interaction regions, we compute numerically some representative anomalies, associated to the lowest order quasi-conservation laws, depending on the deformation parameters {ϵ1, ϵ2}, which include the standard KdV (ϵ1 = ϵ2 = 0), the regularized long-wave (RLW) (ϵ1 = 1, ϵ2 = 0), the modified regularized long-wave (mRLW) (ϵ1 = ϵ2 = 1) and the KdV-RLW (KdV-BBM) type (ϵ2 = 0, ≠ = {0, 1}) equations, respectively. Our numerical simulations show the elastic scattering of two and three solitons for a wide range of values of the set {ϵ1, ϵ2}, for a variety of amplitudes and relative velocities. The KdV-type equations are quite ubiquitous in several areas of non-linear science, and they find relevant applications in the study of General Relativity on AdS3, Bose-Einstein condensates, superconductivity and soliton gas and turbulence in fluid dynamics.
Precision calculation of the axion-nucleon coupling in chiral perturbation theory
Authors: Vonk Thomas , Guo Feng-Kun , Meißner Ulf-G. 
Published: March 2020

Abstract
We derive the axion-nucleon interaction Lagrangian in heavy baryon chiral perturbation theory up to next-to-next-to-leading order. The effective axion-nucleon coupling is calculated to a few percent accuracy.
The Higgs trilinear coupling and the scale of new physics
Authors: Chang Spencer , Luty Markus A. 
Published: March 2020

AbstractWe consider modifications of the Higgs potential due to new physics at high energy scales. These upset delicate cancellations predicted by the Standard Model for processes involving Higgs bosons and longitudinal gauge bosons, and lead to a breakdown of the theory at high energies. We focus on modifications of the Higgs trilinear coupling and use the violation of tree-level unitarity as an estimate of the scale where the theory breaks down. We obtain a completely model-independent bound of $$ \underset{\sim }{<} $$

<
˜

13 TeV for an order-1 modification of the trilinear. We argue that this bound can be saturated only in fine-tuned models, and the scale of new physics is likely to be much lower. The most stringent bounds are obtained from amplitudes involving multiparticle states that are not conventional scattering states. Our results show that a future determination of the Higgs cubic coupling can point to a well-defined scale of new physics that can be targeted and explored at future colliders.
The Page curve of Hawking radiation from semiclassical geometry
Authors: Almheiri Ahmed , Mahajan Raghu , Maldacena Juan , Zhao Ying 
Published: March 2020

Abstract
We consider a gravity theory coupled to matter, where the matter has a higher-dimensional holographic dual. In such a theory, finding quantum extremal surfaces becomes equivalent to finding the RT/HRT surfaces in the higher-dimensional theory. Using this we compute the entropy of Hawking radiation and argue that it follows the Page curve, as suggested by recent computations of the entropy and entanglement wedges for old black holes. The higher-dimensional geometry connects the radiation to the black hole interior in the spirit of ER=EPR. The black hole interior then becomes part of the entanglement wedge of the radiation. Inspired by this, we propose a new rule for computing the entropy of quantum systems entangled with gravitational systems which involves searching for “islands” in determining the entanglement wedge.
Information flow in black hole evaporation
Authors: Chen Hong Zhe , Fisher Zachary , Hernandez Juan , Myers Robert C. , Ruan Shan-Ming 
Published: March 2020

Abstract
Recently, new holographic models of black hole evaporation have given fresh insights into the information paradox [1–3]. In these models, the black hole evaporates into an auxiliary bath space after a quantum quench, wherein the holographic theory and the bath are joined. One particularly exciting development is the appearance of ‘ER=EPR’-like wormholes in the (doubly) holographic model of [3]. At late times, the entanglement wedge of the bath includes the interior of the black hole. In this paper, we employ both numerical and analytic methods to study how information about the black hole interior is encoded in the Hawking radiation. In particular, we systematically excise intervals from the bath from the system and study the corresponding Page transition. Repeating this process ad infinitum, we end up with a fractal structure on which the black hole interior is encoded, implementing the überholography protocol of [4].
Deformations of boards from uneven-aged Norway spruce stands
Authors: Piispanen Riikka , Heikkinen Juha , Valkonen Sauli 
Published: March 2020

AbstractThis study focused on wood distortion of boards sawn from Norway spruce (Picea abies (L.) Karst.) trees grown in uneven-aged stands. The stands were multi-aged with tree ages up to 170 years. In total, 60 trees were harvested from six stands that had been managed by single-tree selection for decades. A butt log and a top log were sawn from each tree, both 2.5 m long. Wood deformations were measured from boards dried to an average moisture content of 7–10% from the 2.5 m long boards. A linear mixed model was constructed to describe the variation in twist deformations in the boards after drying. According to the model analysis, twist increased with greater grain angle, greater average annual ring width and relative ring width difference, greater knot size and count, and the interaction of grain angle with the vertical log position along the stem. Greater distance of the board from the pith was associated with lesser twist. Contrary to expectations, proportion of compression wood and tree position in the stand diameter distribution were not correlated with twist. Pin knots, although their occurrence and size was minimal, had a high degree of correlation with twist. The occurrence and severity of twist remained approximately at the same level as in even-aged Norway spruce as observed in other studies.
Viewpoint oscillation improves the perception of distance travelled in static observers but not during treadmill walking
Authors: Bossard Martin , Goulon Cédric , Mestre Daniel 
Published: March 2020

AbstractOptic flow has been found to be a significant cue for static observers’ perception of distance travelled. In previous research conducted in a large-scale immersive display (CAVE), adding viewpoint oscillations to a radial optic flow simulating forward self-motion was found to modulate this perception. In the present two experiments, we investigated (1) whether the improved distance travelled perceptions observed with an oscillating viewpoint in a CAVE were also obtained when the subjects were wearing a head mounted display (HMD, an Oculus Rift) and (2) whether the absence of viewpoint oscillations during treadmill walking was liable to affect the subjects’ perception of self-motion. In Experiment 1, static observers performed a distance travelled estimation task while facing either a purely linear visual simulation of self-motion (in depth) or the same flow in addition to viewpoint oscillations based on the subjects’ own head oscillations previously recorded during treadmill walking. Results show that the benefits of viewpoint oscillations observed in a CAVE persisted when the participants were wearing an HMD. In Experiment 2, participants had to carry out the same task while walking on a treadmill under two different visual conditions simulating self-motion in depth: the one with and the other without the visual consequences of their head translations. Results showed that viewpoint oscillations did not improve the accuracy of subjects’ distance travelled estimations. A comparison between the two experiments showed that adding internal dynamic information about actual self-motion to visual information did not allow participants better estimates.
Hydrogeologische Herkunft und geothermisches Potenzial der Thermalquellen von Hintertux, Österreich
Authors: Heldmann Claus-Dieter , Sass Ingo , Schäffer Rafael 
Published: March 2020

ZusammenfassungEuropas höchste Thermalquellen in Hintertux, Tirol, sind bis zu 22,5 °C warm und werden zu etwa 30 % genutzt. Bisher lag kein detailliertes konzeptionelles Modell vor, das alle Besonderheiten der Anomalie gemeinsam erklärt hätte. Nur mit einem hydrogeologischen Modell ist eine Erweiterung der Nutzung nachhaltig planbar. Es wurden klassische hydrogeologische und hydrochemische Methoden eingesetzt, unter anderem natürliche Tracer, geochemische Indikatoren und stabile Isotopen (δ18O, δD, δ34S), um die Entstehung der Thermalwässer und darin involvierte Grundwasserleiter zu identifizieren. Die Untersuchungen wurden 2011–2018 an Wässern aus 14 weiteren Quellen und zwei Tunneln durchgeführt. Die Studie zeigt, dass das Grierkar zum meteorischen Einzugsgebiet der Thermalquellen gehört, wobei der Abfluss über die Schwinden an der Grieralm in den Hochstegenmarmor gelangt. Die Temperaturerhöhung erfolgt ursächlich aus dem weiteren Zufluss (20–40 %) von tieferen Zentralgneiswässern im Nordhang des Schmittenberges, wobei diese hydraulische Verbindung wahrscheinlich im Zusammenhang mit den Tuxer Scherzonen steht.
Climate humanitarian visa: international migration opportunities as post-disaster humanitarian intervention
Authors: Matias Denise Margaret S. 
Published: March 2020

AbstractWith global action being outpaced by climate change impacts, communities in climate-vulnerable countries are at increased risk of incurring climate-induced losses and damages. In the last few years, disasters from extreme weather events such as typhoons have increased and have breached records, with typhoon Haiyan being the strongest ever typhoon to make landfall. Such an event solicited global compassion and altruism where Canada and the USA, apart from doling out traditional humanitarian aid, also offered immigration relief opportunities to typhoon Haiyan victims who have familial connections to their residents. Drawing from these immigration relief interventions, this paper uses a sociopolitical approach in proposing a climate humanitarian visa that would be offered to climate change victims on the basis of transnational family networks and skilled labor. Noting that several countries such as in Europe have demographic deficits and labor shortages, such a scheme would benefit both climate change victims and receiving countries. To counter the risk of selective compassion against economically trapped populations, potential receiving countries could provide skills upgrading geared toward addressing their labor shortages through their existing development programs. While migration is only one strategy in a spectrum of responses to climate change impacts, a climate humanitarian visa could provide climate change victims a legal choice for mobility while invoking altruism, hospitality, and compassion from potential receiving countries, whether or not they historically cause climate change.
Participatory design of persuasive technology in a blended learning course: A qualitative study
Authors: Engelbertink Monique M. J. , Kelders Saskia M. , Woudt-Mittendorff Kariene M. , Westerhof Gerben J. 
Published: March 2020

AbstractWhereas blended learning can deliver several benefits to students in higher education, their achievement depends on how exactly it is designed. A participatory design is recommendable to try to meet the needs of all stakeholders. The Persuasive System Design-model can be used to motivate students during the online part of the course. In the design there has to be an optimal blend between the different parts of the course. A participatory design is used to design a blended learning course of autobiographical reflection for second year social work students. The blended course was developed in six meetings with a working group, including all stakeholders (students, teachers, instructional designers, educational experts and professionals). Almost all techniques of the first three categories of the PSD-model were used in the design of the blended course. None of the techniques of the fourth category ‘Social Support’ of the PSD-model were used, mostly because they touch on the personal process of autobiographical reflection. It was considered helpful for teachers to have a protocol that assists them in blending the different parts and this in turn could stimulate students to be engaged in the different parts of the blended learning course. In this study, we found that the participatory design approach may lead to an engaging blended learning course that encourages the use of persuasive technology with an optimal focus on content, target group, context and ethical aspects of the blended course. We suggest adding a new fifth category ‘Blended Learning Support’.
Identifying areas of degrading and improving groundwater-quality conditions in the State of California, USA, 1974–2014
Authors: Jurgens Bryant C. , Fram Miranda S. , Rutledge Jeffrey , Bennett V. George L. 
Published: March 2020

AbstractAreas of improving and degrading groundwater-quality conditions in the State of California were assessed using spatial weighting of a new metric for scoring wells based on constituent concentrations and the direction and magnitude of a trend slope (Sen). Individual well scores were aggregated across 2135 equal-area grid cells covering the entire groundwater resource used for public supply in the state. Spatial weighting allows results to be aggregated locally (well or grid cell), regionally (groundwater basin), provincially, or statewide. Results differentiate degrading (increasing concentration trends) areas with low to moderate concentrations (unimpaired) from degrading areas with moderate to high concentrations (impaired). Results also differentiate improving areas (decreasing concentration trends) in the same manner. Multi-year to decadal groundwater-quality trends were computed from periodic, inorganic water-quality data for 38 constituents collected between 1974 and 2014 for compliance monitoring of nearly 13,000 public-supply wells (PSWs) in the State of California. Mann-Kendall (MK) rank correlations and Sen’s slope estimator were used to detect statistically significant trends for the entire period of recorded data (long-term trend), for the period since 2000 (recent trend), for different pumping seasons (seasonal trend), and for reversals of trends. Statewide, the most frequently detected trends since 2000 were for nitrate (36%), gross alpha/uranium (10%), arsenic (14%), total dissolved solids (TDS) (23%), and the major ions that contribute to TDS (19–28%). The Transverse and Selected Peninsular Ranges (TSPR) and the San Joaquin Valley (SJV) hydrogeologic provinces had the largest percentage of areas with moderate to high nitrate concentrations and groundwater quality trends. Improving nitrate concentrations in parts of the TSPR is associated with long-term managed aquifer recharge that has replaced historical, agriculturally affected groundwater with low-nitrate recharge in parts of the TSPR. This example suggests that application of dilute, excess surface water to agricultural fields during the winter could improve groundwater-quality in the SJV over the long term.