bluuebunny/crossref_metadata_2025_split huggingface dataset:
Krylov Solvability of Unbounded Inverse Linear Problems
Authors: Caruso Noè Angelo , Michelangeli Alessandro 
Published: December 2020

AbstractThe abstract issue of ‘Krylov solvability’ is extensively discussed for the inverse problem$$Af=g$$Af=gwhereAis a (possibly unbounded) linear operator on an infinite-dimensional Hilbert space, andgis a datum in the range ofA. The question consists of whether the solutionfcan be approximated in the Hilbert norm by finite linear combinations of$$g,Ag,A^2g,\dots $$g,Ag,A2g,⋯, and whether solutions of this sort exist and are unique. After revisiting the known picture whenAis bounded, we study the general case of a densely defined and closedA. Intrinsic operator-theoretic mechanisms are identified that guarantee or prevent Krylov solvability, with new features arising due to the unboundedness. Such mechanisms are checked in the self-adjoint case, where Krylov solvability is also proved by conjugate-gradient-based techniques.
On Efficiently Solvable Cases of Quantum k-SAT
Authors: Aldi Marco , de Beaudrap Niel , Gharibian Sevag , Saeedi Seyran 
Published: December 2020

AbstractEstimating ground state energies of local Hamiltonian models is a central problem in quantum physics. The question of whether a given local Hamiltonian is frustration-free, meaning the ground state is the simultaneous ground state of all local interaction terms, is known as the Quantum k-SAT (k-QSAT) problem. In analogy to its classical Boolean constraint satisfaction counterpart, the NP-complete problem k-SAT, Quantum k-SAT is $$\hbox {QMA}_1$$

QMA
1

-complete (for $$k\ge 3$$

k
≥
3

, and where $$\hbox {QMA}_1$$

QMA
1

is a quantum generalization of NP with one-sided error), and thus likely intractable. But whereas k-SAT has been well-studied for special tractable cases, as well as from a “parameterized complexity” perspective, much less is known in similar settings for k-QSAT. Here, we study the open problem of computing satisfying assignments to k-QSAT instances which have a “dimer covering” or “matching”; such systems are known to be frustration-free, but it remains open whether one can efficiently compute a ground state. Our results fall into three directions, all of which relate to the “dimer covering” setting: (1) We give a polynomial-time classical algorithm for k-QSAT when all qubits occur in at most two interaction terms or clauses. (2) We give a “parameterized algorithm” for k-QSAT instances from a certain non-trivial class, which allows us to obtain exponential speedups over brute force methods in some cases. This is achieved by reducing the problem to solving for a single root of a single univariate polynomial. An explicit family of hypergraphs, denoted Crash, for which such a speedup is obtained is introduced. (3) We conduct a structural graph theoretic study of 3-QSAT interaction graphs which have a “dimer covering”. We remark that the results of (2), in particular, introduce a number of new tools to the study of Quantum SAT, including graph theoretic concepts such as transfer filtrations and blow-ups from algebraic geometry.
Cylindric Hecke Characters and Gromov–Witten Invariants via the Asymmetric Six-Vertex Model
Authors: Korff Christian 
Published: December 2020

AbstractWe construct a family of infinite-dimensional positive sub-coalgebras within the Grothendieck ring of Hecke algebras, when viewed as a Hopf algebra with respect to the induction and restriction functor. These sub-coalgebras have as structure constants the 3-point genus zero Gromov–Witten invariants of Grassmannians and are spanned by what we call cylindric Hecke characters, a particular set of virtual characters for whose computation we give several explicit combinatorial formulae. One of these expressions is a generalisation of Ram’s formula for irreducible Hecke characters and uses cylindric broken rim hook tableaux. We show that the latter are in bijection with so-called ‘ice configurations’ on a cylindrical square lattice, which define the asymmetric six-vertex model in statistical mechanics. A key ingredient of our construction is an extension of the boson-fermion correspondence to Hecke algebras and employing the latter we find new expressions for Jing’s vertex operators of Hall–Littlewood functions in terms of the six-vertex transfer matrices on the infinite planar lattice.
A $$C^1$$-continuous Trace-Finite-Cell-Method for linear thin shell analysis on implicitly defined surfaces
Authors: Gfrerer Michael H. 
Published: December 2020

AbstractA Trace-Finite-Cell-Method for the numerical analysis of thin shells is presented combining concepts of the TraceFEM and the Finite-Cell-Method. As an underlying shell model we use the Koiter model, which we re-derive in strong form based on first principles of continuum mechanics by recasting well-known relations formulated in local coordinates to a formulation independent of a parametrization. The field approximation is constructed by restricting shape functions defined on a structured background grid on the shell surface. As shape functions we use on a background grid the tensor product of cubic splines. This yields $$C^1$$

C
1

-continuous approximation spaces, which are required by the governing equations of fourth order. The parametrization-free formulation allows a natural implementation of the proposed method and manufactured solutions on arbitrary geometries for code verification. Thus, the implementation is verified by a convergence analysis where the error is computed with an exact manufactured solution. Furthermore, benchmark tests are investigated.
Evaluation of contact force distribution along a curve, based on measured electric potentials
Authors: Magyar Bálint , Wohlfart Richárd , Zana Roland , Hénap Gábor , Csernák Gábor , Stepan Gabor 
Published: December 2020

AbstractThe paper presents the first results of an exploratory research work, aiming the experimental evaluation of the mechanical contact between conforming surfaces of metallic bodies. The proposed procedure—that is based on the measurement of electric potentials—is able to determine the actual contact pattern and estimate the force distribution on the opposing surfaces. In the present paper, the contact properties along a curve are evaluated, but the basic principles supporting the solution of the more general surface contact problem are also laid down. The goal of this research work is to provide a reliable basis for the investigation of contact-related effects on the modal properties of structures and machines. The distribution of electric contact resistivity can also be assessed using this method, opening the way to the refined characterization of electric switches and connectors. During the application of the method, measured electric voltage values are processed by a neural network trained on a data set generated by finite element software. The resulting electric contact conductivity distribution is used to determine the contact force distribution, taking into account the equilibrium of forces and moments. The results are also checked by available alternative experimental methods.
The cognitive ability and working memory framework: Interpreting cognitive reflection test results in the domain of the cognitive experiential theory
Authors: Engin Ayşegül 
Published: December 2020

AbstractThe cognitive reflection test (hereafter, CRT) is a widely used tool in studies that deal with human decision-making and problem-solving. However, the interpretation of the results of the test remains an open discussion in extant literature. Despite the high predictive power, the characteristics of a decision-maker measured by the CRT remain unclear. This article suggests a novel and inclusive framework that relates the CRT to the cognitive experiential theory (hereafter, CET), which is a well-established dual-process theory. The framework explains the observed phenomena (e.g., individual decision-maker differences) using data from five laboratory experiments. The framework is inclusive because it provides possible explanations for the results in the published literature. The overall results support the argument that the CRT measures the efficiency of the resources of an individual’s working memory. In contrast, the rationality experientiality inventory (hereafter, REI) (a measurement tool of the cognitive experiential theory) captures an individual’s cognitive ability. The efficient use of the working memory leads to the full potential of decision-makers’ cognitive abilities in analytical tasks, thereby indicating thatcognitive ability and working memoryform a viable framework for studies in the disciplines behavioral operational research (hereafter, OR) and decision sciences.
Incentivizing by example and money
Authors: Bauer Thomas , Wirl Franz 
Published: December 2020

AbstractLeaders are role models that affect their employees’ efforts. The effect depends on how much an employee identifies with the “boss”. Since this degree of identification is private information of the employee, additional financial incentives must be provided. Therefore, we study a principal-agent problem in which the principal affects the agent’s effort by her own effort and by financial incentives. The resulting principal-agent problem has a few non-standard specifics such as: (i) bilateral externalities as the principal’s effort affects the agent and vice versa and (ii) endogenous reservation utility of the agent. Combined, this leads to non-trivial and interesting contracts.
An analysis of capability meta-models for expressing dynamic business transformation
Authors: Koutsopoulos Georgios , Henkel Martin , Stirna Janis 
Published: December 2020

AbstractEnvironmental dynamism is gaining ground as a driving force for enterprise transformation. To address the changes, the capabilities of digital enterprises need to adapt. Capability modeling can facilitate this process of transformation. However, a plethora of approaches for capability modeling exist. This study explores how concepts relevant to change have been implemented in the meta-models of these approaches, aiming to visualize relationships among change-related concepts, and identify ways to improve capability modeling toward a more efficient depiction of capability change. The concepts are visualized in concept maps, and a framework is developed to assist the classification of concepts relevant to change functions. Similarities and differences among the existing models are discussed, leading to suggestions toward improvements of capability modeling for capability adaptation.
Evolvement of Peer Support Workers’ Roles in Psychiatric Hospitals: A Longitudinal Qualitative Observation Study
Authors: Nossek Alexa , Werning Anna , Otte Ina , Vollmann Jochen , Juckel Georg , Gather Jakov 
Published: December 2020

AbstractPeer support workers (PSWs) use their experiential knowledge and specific skills to support patients in their recovery process. The aim of our study was to examine the integration and role-finding process of PSWs in adult psychiatric hospitals in Germany. We conducted open nonparticipant observations of 25 multiprofessional team meetings and 5 transregional peer support worker meetings over a period of six months. The data were analyzed using qualitative content analysis. Regarding the integration of PSWs into multiprofessional teams, we identified three subcategories: “Features of success,” “challenges” and “positioning between team and patients.” Concerning the PSWs’ roles, we developed two subcategories: “Offers” and “self-perception.” The PSWs’ specific roles within a multiprofessional mental healthcare team evolve in a process over a longer period of time. This role-finding process should be supported by a framework role description which leaves sufficient freedom for individual development. Regular opportunities for mutual exchange among PSWs can help to address specific support needs at different points in time.
AnnuityRIR: an R-package to approximate the value of an annuity according to the non-central moments of the capitalization factor
Authors: Rambaud Salvador Cruz , Maturo Fabrizio , Pérez Ana Maria Sánchez , Squillante Massimo 
Published: December 2020

AbstractThe aim of this paper is to design the package of the R statistical software called “Annuity Random Interest Rate”, referred hereinafter as , in order to calculate the value of ann-annuity with payments of one unit each when the interest rate is random. To do this, we have employed different approaches; the two main methodologies treated in this study consider that all non-central moments of the capitalization factor are known, or contrarily some of them are unknown. Consequently, five different approaches have been developed and the practical application of the proposed methods is reflected in this paper by pricing an annuity with a random risk-free interest rate during the last ten years. The version is available from CRAN:https://cran.r-project.org/web/packages/AnnuityRIR/index.html.
Dynamics of N-P-K demand and uptake in cassava
Authors: Adiele Joy Geraldine , Schut Antonius G. T. , Ezui Kodjovi S. , Pypers Pieter , Giller Ken E. 
Published: December 2020

AbstractFertilizers are required to improve productivity of cassava and meet the increasing demand for cassava as food, feed, or raw material for processing industries. Our objective was to develop nutrition indices for N, P, and K to provide quantitative insight in the dynamics of nutrient demand and uptake of cassava. On-farm experiments were conducted at six locations in Nigeria from 2016 to 2018, across the major cassava growing agro-ecologies of West Africa. Nitrogen, P, and K were applied at different rates. Uptake of nutrients was measured in leaves, stems, and storage roots at 4, 8, and 12 or 14 months after planting (MAP) and used to construct NPK dilution curves and nutrition indices. About 67, 61, and 52% of total N, P, and K were taken up at 4 MAP, with a maximum uptake rate of 0.21, 0.03, and 0.12 g/m2/d for N, P, and K, respectively. Nutrient concentrations in stems and storage roots declined gradually, in contrast to concentrations in the leaves that fluctuated within narrow ranges. Dilution curves and nutrition indices for N, P, and K were established for the first time in cassava. Dilution curves of N, P, and K in the crop for the highest NPK application treatment were described as Nc = 82DM−0.61, Pc = 7.4DM−0.54, and Kc = 43DM−0.54, when total biomass was between 5 and 57 t/ha dry matter (DM). The nutrition indices were linearly related to relative crop biomass. Insight into the nutrient uptake and dilution patterns during the growth cycle can help to understand the temporal nutrient demands of cassava and identify sustainable management practices. Initial ample supply of N and P and moderate K, with extra K top-dress during the second growth phase, will benefit cassava growth and yield. Furthermore, such information provides a basis to develop a dynamic model to simulate nutrient-limited growth of cassava.
Productive integration, economic recession and employment in Europe: an assessment based on vertically integrated sectors
Authors: Villani Davide , Fana Marta 
Published: December 2020

AbstractThe Covid-19 crisis has revamped the discussion about the redefinition of GVC. This paper contributes to the debate, analysing the productive relationships between European countries in four key manufacturing activities. In particular, the paper addresses two objectives. First, it maps the degree of productive integration in Europe, focusing on the generation of employment in the production of exported intermediate inputs and final goods. Second, it provides a preliminary assessment of the potential impact on employment that the current economic crisis will have on some manufacturing activities across Europe. The analysis is realised employing the concept of vertically integrated labour (Pasinetti 1973) which allows to account for the employment directly and indirectly involved in the production of final goods. The estimations are derived from Multi-Regional Input–Output tables to map the supply chain and to differentiate between the employment involved in the production of exported intermediate inputs and final goods. The results show that most of the employment involved in the production of final output of the activities studied in the paper is linked to international trade. Although Europe shows a high degree of productive links, there are important differences in the modality of insertion in the productive structure of European countries. Moreover, the impact on the level of employment due to the current economic crisis can be significant, affecting more than 1.3 million of people in Europe. These results are relevant to policy makers, who should consider carefully the high degree of linkages of the European economies when designing industrial policies and measure of support to the economy.
scLM: Automatic Detection of Consensus Gene Clusters Across Multiple Single-Cell Datasets
Authors: Song Qianqian , Su Jing , Miller Lance D. , Zhang Wei 
Published: December 2020

Abstract
In gene expression profiling studies, including single-cell RNAsequencing (scRNA-seq) analyses, the identification and characterization of co-expressed genes provides critical information on cell identity and function. Gene co-expression clustering in scRNA-seq data presents certain challenges. We show that commonly used methods for single-cell data are not capable of identifying co-expressed genes accurately, and produce results that substantially limit biological expectations of co-expressed genes. Herein, we present single-cell Latent-variable Model (scLM), a gene co-clustering algorithm tailored to single-cell data that performs well at detecting gene clusters with significant biologic context. Importantly, scLM can simultaneously cluster multiple single-cell datasets, i.e., consensus clustering, enabling users to leverage single-cell data from multiple sources for novel comparative analysis. scLM takes raw count data as input and preserves biological variation without being influenced by batch effects from multiple datasets. Results from both simulation data and experimental data demonstrate that scLM outperforms the existing methods with considerably improved accuracy. To illustrate the biological insights of scLM, we apply it to our in-house and public experimental scRNA-seq datasets. scLM identifies novel functional gene modules and refines cell states, which facilitates mechanism discovery and understanding of complex biosystems such as cancers. A user-friendly R package with all the key features of the scLM method is available at https://github.com/QSong-github/scLM.
Determining Gravity Wave Sources and Propagation in the Southern Hemisphere by Ray‐Tracing AIRS Measurements
Authors: Perrett Jon A. , Wright Corwin J. , Hindley Neil P. , Hoffmann Lars , Mitchell Nicholas J. , Preusse Peter , Strube Cornelia , Eckermann Stephen D. 
Published: December 2020

AbstractGravity waves (GWs) are key drivers of atmospheric circulation. Understanding their sources and propagation is essential to improving weather and climate models. We apply a 3D Stockwell Transform to 1 month of stratospheric temperature data from NASA's Atmospheric InfraRed Sounder to obtain 3D GW measurements and parameters. We use ray‐tracing methods to determine the sources and propagation characteristics of these GWs over the entire Southern Ocean. We trace 1.28 million GW measurements per day for the month of June 2010. Our analysis suggests that ground‐based sources around the Andes, Antarctic Peninsula, and Kerguelen play major roles, and that the GWs generated by these and other sources travel large zonal distances. We show evidence that GWs propagate into the 60°S belt, a possible source of “missing momentum flux” in GCMs at this latitude. These results emphasize the need for models to incorporate the possibility that GWs can exhibit large horizontal propagation.
Inherited State of Stress as a Key Factor Controlling Slip and Slip Mode: Inference From the Study of a Slow Slip Event in the Longitudinal Valley, Taiwan
Authors: Canitano Alexandre , Godano Maxime , Thomas Marion Y. 
Published: December 2020

AbstractUsing borehole strainmeters, we detected a 13‐day long slow slip event in 2011 with Mw = 5.45 on the Longitudinal Valley Fault, Taiwan. It has been likely promoted by the significant Coulomb stress changes (∼0.5–1 MPa) imparted by a combination of coseismic and postseismic slip of the 2003 Chengkung earthquake. Using kinematic slip models, we infer that the slow event has accommodated about 15%–35% of the slip deficit accumulated from 1997 to 2011 in its source region. Further, we find that inherited state of stress may have controlled the slow event southward propagation. We also highlight a spatiotemporal correlation between the slow event and a cluster of repeating microearthquakes, suggesting a complex interplay between seismic and aseismic processes on the fault, where transient aseismic regions are adjacent to highly coupled zones.
Implications of Electron Detachment in Associative Collisions of Atomic Oxygen Anion with Molecular Nitrogen for Modeling of Transient Luminous Events
Authors: Janalizadeh Reza , Pasko Victor P. 
Published: December 2020

AbstractElectron detachment from O− is important for understanding of lightning‐induced upper atmospheric discharges. Contrary to previous studies, Rayment and Moruzzi (1978) (RM78) argue that the associative detachment reaction of O− with N2 proceeds with N2 in its ground state. Here, we analyze the experimental setup in RM78 and demonstrate that vibrationally excited N2 may have in fact contaminated the results, the theoretical approach in RM78 requires corrections, and the rate calculations provided in RM78 are inconsistent. As the vibrational temperature of N2 remains relatively low in the initial stages of gas discharges in air, i.e., streamer formation, we conclude that if in fact vibrationally excited N2 is required for the O− + N2 → N2O + e reaction to proceed, the process will happen only in later stages of the discharge, e.g., during streamer to leader transition. Controlled experiments are required to reconcile the literature on the reaction of O− with ground state N2.
Comprehensive Study of the Climatology of the Quasi‐6‐Day Wave in the MLT Region Based on Aura/MLS Observations and SD‐WACCM‐X Simulations
Authors: Qin Yusong , Gu Sheng‐Yang , Teng Chen‐Ke‐Min , Dou Xian‐Kang , Yu You , Li Na 
Published: December 2020

AbstractThe westward quasi‐6‐day wave (Q6DW) with zonal wavenumber 1 is a prominent and recurrent phenomenon in the mesosphere and lower thermosphere (MLT) and has a significant impact on day‐to‐day ionospheric variability. Geopotential height measurements from Aura Microwave Limb Sounder and Specified Dynamics Whole Atmosphere Community Climate Model eXtended Version simulations during 2005–2019 are utilized to study the climatological variations of Q6DW. The spectral analysis clearly indicates that four typical Q6DW events occur in the MLT region before and after the two equinoxes in 1 year. The wave amplitudes in the summer hemisphere are considerably larger than the amplitudes in the winter hemisphere. The Eliassen‐Palm flux diagnostics show that the wave source of the post‐September equinox event is located in both hemispheres, while the sources of the other three Q6DW events are in the winter hemisphere. The diagnostic analysis results show that the climatological features of Q6DW are primarily due to the seasonal variations of the mean flow, which can determine the Q6DW critical layers, baroclinic/barotropic instability, and waveguides. Specifically, the Q6DW can be amplified in the summer hemisphere mesosphere at high latitudes during pre‐ and postequinox periods when the critical layers penetrate the unstable region. At the two equinoxes, the Q6DW can also propagate into the MLT region with similar amplitudes in both hemispheres due to the weak zonal mean flow but without additional amplification. At the two solstices, the Q6DW is suppressed because the critical layers envelop the whole unstable region, which prevents its amplification through wave‐mean flow interaction.