Miracle-dz/UniFAR-FTUs huggingface dataset:
Simulation of Hydraulic Stimulation: Acoustic Wave Emission in Fractured Porous Media Using Local and Global Partition-of-Unity Finite Element

Hydraulic Fracturing (HF) is an effective stimulation process for extracting oil and gas from unconventional low-permeable reservoirs. The process is conducted by injecting high-pressure fluids into the ground to generate fracture networks in rock masses and stimulate natural fractures to increase the permeability of formation and extract oil and gas. Due to the multipleand coupled-physics involved, hydraulic fracturing is a complex engineering process. The extent of the induced fractures and stimulated volume and reactivation of natural faults and fractures are some of the practical issues associated with hydraulic fracturing. Acoustic Emission (AE) monitoring and analysis are used to probe the behaviour of solid materials in such applications. The process of elastic wave propagation induced by an abrupt local release of stored strain energy is known as acoustic, microseismic, and seismic emission (depending on the context and the magnitude of the event). These emissions can be triggered by material bifurcation-instabilities like slope slipping, fault-reactivation, pore collapsing, and cracking processes that are all categorized as localization phenomena. The microseismic monitoring industry attempts to relate acoustic emissions measured by geophones to the nature of the stimulated volume created during hydraulic fracturing. This process is full of uncertainties and researchers have not yet focused on both explicitly modeling the process of fracture reactivation and the accurate simulation of acoustic wave propagations resulting from the localization. The biggest gap in the modeling literature is that most of the previous works fail to accurately simulate the process of transient acoustic wave propagation through the fractured porous media following the elastic energy release. Instead of explicitly
Physically real and virtual reality exposed line bisection response patterns: visuospatial attention allocation in virtual reality

Introduction To understand the nature of hemispatial attention allocation in virtual reality (VR), a line bisection task (LBT) was administered both in a real environment and a virtual environment to assess the rate of pseudoneglect. The mental construction of real and virtual environments was assumed to increase visuospatial activity in right hemisphere-related cognitive processes; an alteration in the activity that manifests in the direction and rate of line bisection lateral error. Methods In the present study, fifty-one right-handed healthy college students were recruited. They performed a line bisection task in real and virtual environments. Results The obtained data showed that LBT errors in real and VR environments were correlated and individually consistent. Furthermore, a leftward LBT error was found in the physically real environment, however, in a VR the line bisection bias drifted towards the right hemispace. Participants with a lower right-handedness score showed a lower rate of left LBT bias in a real environment, but in VR, their LBT error showed a stronger rightwards error. Discussion Participants showed an individually consistent pattern in both real and VR environments, but VR-induced visuospatial reality construction was associated with rightward LBT bias in a virtual environment.
Lie algebroids, gauge theories, and compatible geometrical structures

The construction of gauge theories beyond the realm of Lie groups and algebras leads one to consider Lie groupoids and algebroids equipped with additional geometrical structures which, for gauge invariance of the construction, need to satisfy particular compatibility conditions. This paper is supposed to analyze these compatibilities from a mathematical perspective.In particular, we show that the compatibility of a connection with a Lie algebroid that one finds is the Cartan condition, introduced previously by A. Blaom. For the metric on the base [Formula: see text] of a Lie algebroid equipped with any connection, we show that the compatibility suggested from gauge theories implies that the foliation induced by the Lie algebroid becomes a Riemannian foliation. Building upon a result of del Hoyo and Fernandes, we prove, furthermore, that every Lie algebroid integrating to a proper Lie groupoid admits a compatible Riemannian base. We also consider the case where the base is equipped with a compatible symplectic or generalized Riemannian structure.
xtdcce: Estimating Dynamic Common Correlated Effects in Stata

This article introduces a new Stata command, xtdcce, to estimate a dynamic common correlated effects model with heterogeneous coefficients. The estimation procedure mainly follows Chudik and Pesaran (2015b), in addition the common correlated effects estimator (Pesaran, 2006), as well as the mean group (Pesaran and Smith, 1995) and the pooled mean group estimator (Shin et al., 1999) are supported. Coefficients are allowed to be heterogeneous or homogeneous. In addition instrumental variable regressions and unbalanced panels are supported. The Cross Sectional Dependence Test (CD Test) is automatically calculated and presented in the estimation output. Small sample time series bias can be corrected by jackknife correction or recursive mean adjustment. Examples for empirical applications of all estimation methods mentioned above are given
Convective systems and rainfall in East Africa

East Africa is particularly vulnerable to weather extremes, with severe weather linked to thousands of deaths per year. Improved forecasts of convective events in this region are urgently needed, from both nowcasting and numerical weather prediction models. Improving these forecasts requires further knowledge of convection in this region. This study aims to improve understanding of convective events in East Africa, based on a six‐year climatology of convective life cycles and the associated precipitation. Convective systems are identified as contiguous areas of cold cloud in geostationary satellite measurements over East Africa. A tracking algorithm is used to trace the evolution of the properties of these systems through time and space. Matching the systems to surface precipitation obtained from satellite microwave observations provides insight into how the life cycles of these systems relate to precipitation at the surface. Over the region as a whole, 59% of the accumulated precipitation can be attributed to the tracked convective systems. The majority (81%) of heavy precipitation events ( ≥$$ \ge $$ 10 mm ·$$ \cdotp $$ hr−1) are attributable to convective systems, while light rainfall events ( <$$ < $$ 1 mm ·$$ \cdotp $$ hr−1) are not (1.8%). Most of the tracked convective systems have an area less than 400 km2 and last for less than an hour. However, the less frequent larger longer‐lived systems produce the majority of the regional accumulated precipitation. Composite life cycles of the tracked systems show rapid intensification and the heaviest precipitation initially, followed by a steady increase in area and weakening in intensity before the system decays. Finally, the Madden–Julian oscillation, which plays a key role in intraseasonal rainfall variability in the region, is also linked to the amount of rainfall due to convective systems through changes in the frequency and properties of these systems.
PASSIVE FUZZY CONTROLLER DESIGN FOR PERTURBED NONLINEAR DRUM-BOILER SYSTEM WITH MULTIPLICATIVE NOISE

This paper addresses the problem of designing robust passive fuzzy controller for uncertain nonlinear drum-boiler system with multiplicative noise. For this problem, the Takagi-Sugeno (T-S) fuzzy model is employed to represent the nonlinearities of boiler system to be an analyzed system. Based on the T-S fuzzy model, the sufficient stability conditions are developed as the Linear Matrix Inequality (LMI) problem by Ito’s formula and Lyapunov function. Besides, the strictly input passive theory is employed to discuss the external disturbance effect on system and investigate attenuation performance for disturbance. With applying the proposed controller design technique, the perturbed nonlinear boiler system with multiplicative noise can be guaranteed to be mean square stable and strict input passive.
Homologous Circular-ribbon Flares Driven by Twisted Flux Emergence

In this paper, we report two homologous circular-ribbon flares associated with two filament eruptions. They were well observed by the New Vacuum Solar Telescope and the Solar Dynamics Observatory on 2014 March 5. Prior to the flare, two small-scale filaments enclosed by a circular pre-flare brightening lie along the circular polarity inversion line around the parasitic polarity, which has shown a continuous rotation since its first appearance. Two filaments eventually erupt in sequence associated with two homologous circular-ribbon flares and display an apparent writhing signature. Supplemented by the nonlinear force-free field extrapolation and the magnetic field squashing factor investigation, the following are revealed. (1) This event involves the emergence of magnetic flux ropes into a pre-existing polarity area, which yields the formation of a 3D null-point topology in the corona. (2) Continuous input of the free energy in the form of a flux rope from beneath the photosphere may drive a breakout-type reconnection occurring high in the corona, supported by the pre-flare brightening. (3) This initiation reconnection could release the constraint on the flux rope and trigger the MHD instability to first make filament F1 lose equilibrium. The subsequent more violent magnetic reconnection with the overlying flux is driven during the filament rising. In return, the eruption of filament F2 is further facilitated by the reduction of the magnetic tension force above. These two processes form a positive feedback to each other to cause the energetic mass eruption and flare.
Moving Fast, Going Big, and Playing for Keeps: The Rapid Institutionalization of Bottom-up Change

Prior research suggests that frontline change ideas are especially valuable for improving organizational functioning. Yet bottom-up change processes are generally characterized as failure-prone, slow, and incremental, or as requiring heroic and politically fraught collective mobilization efforts. This paper offers a novel theoretical model that specifies how frontline change ideas can be implemented quickly, simultaneously, largely without protracted political battles, and in ways that promote their long-term institutionalization. We analyze data from a two-year qualitative field study of the trajectory of 33 changes ideas introduced by frontline staff—bedside nurses, physicians, frontline managers, and others— to address longstanding issues at a U.S. hospital responding to the exogenous shock of the Covid-19 pandemic. By comparing ideas that had become integrated into normal operations nearly two years later to those that failed to be implemented or to persist, we induce a set of practices associated with the rapid institutionalization of bottom-up change ideas. Our study suggests that traditional change management tactics supporting a slow, experimental and incremental “small-wins” or more political coalition-building approach to bottom-up change in the existing literature may be less effective at implementing change that endures in the aftermath of an exogenous shock. Exogenous shocks can temporarily shift both field-level and organizational-level opportunity structures in ways that create a favorable but unpredictably brief window of opportunity for implementing change amid lowered barriers. We find that to seize such a moment may require an alternative set of change tactics that entail moving fast, going big, and playing for keeps. Please do not cite or share without permission
The Effect of Self-Confidence, Adversity Quotient, and Self-Regulated Learning on Learning Motivation

This study aims to analyse: (1) The effect of self-confidence on learning motivation; (2) The effect of adversity quotient on learning motivation; and (3) The effect of self-regulated learning on learning motivation in economics subject for Class XI Social Sciences at Public High School 2 Purbalingga in the 2022 / 2023 academic year. The population in this study were all Class XI Social Sciences students at Public High School 2 Purbalingga for the 2022 / 2023 academic year. Sampling in this study used a proportionate stratified random sampling technique of 144 respondents. The data analysis technique used was multiple linear regression analysis with the SPSS version 23 program. The data collection method used questionnaires and interviews. Based on the results of research and data analysis, it can be concluded that self-confidence has a positive effect on learning motivation, adversity quotient has a positive effect on learning motivation, and self-regulated learning has a positive effect on learning motivation.
Stability and Set-Invariance Testing for Interval Systems

Many works dealing with the stability analysis of interval systems developed criteria based on matrices that majorize (in a certain sense) the interval matrices describing the system dynamics. Besides this already classical employment, we prove that the majorant matrices also contain valuable information for the study of the exponentially decreasing sets, invariant with respect to the trajectories of the interval systems. The interval systems are considered with both discrete- and continuous-time dynamics. The invariant sets are characterized by arbitrary shapes, defined in terms of Holder vector p-norms, 1 <= p <= infinite . Our results cover two types of interval systems, namely described by interval matrices of general form and by some particular classes of interval matrices. For the general case, we formulate necessary and sufficient conditions, when the shape of the invariant sets is defined by the norms p = 1, infinite, and sufficient conditions, when the shape is defined by the norms 1< p < infinite. For the particular cases, we provide necessary and sufficient conditions for all norms 1 <= p <= infinite.
Variations in VOCs Emissions and Their O3 and SOA Formation Potential among Different Ages of Plant Foliage

Volatile organic compounds (VOCs) emitted by plant foliage play an important role in ozone (O3) and secondary organic aerosol (SOA) formation. Their emissions can be influenced by the leaf age. We explored the VOCs emissions and their effects on the formation of O3 and SOA from plant foliage in different ages. VOCs emissions from the young, mature, and senescent leaves of Ginkgo biloba, Ligustrum lucidum, and Forsythia suspensa were measured using the dynamic enclosure system and the TD–GC–MS technique. Based on the emission rates of quantified compounds, their potential to form O3 and SOA was estimated. Results showed that there were significant differences in the VOCs emission rate and their composition among leaves in different ages. The emission rate of the total VOCs by young leaves was the highest, while the lowest by senescent leaves. Monoterpenes were the dominant VOCs category, and isoprene emission had the lowest contribution for the leaves at each age. With increasing leaf age, the proportion of monoterpenes emission increased, and the proportion of sesquiterpenes decreased. The variations of isoprene and other VOCs were different. The potentials of total VOCs, isoprene, monoterpenes, sesquiterpenes, and other VOCs to form O3 (OFP) and SOA (SOAP) varied significantly among leaves at different ages. The total OFP and SOAP were the highest by young leaves, while the lowest by senescent leaves. With increasing leaf age, the contribution of monoterpenes to OFP and SOAP also increased, while that of sesquiterpenes decreased. Our study will provide support for the more accurate parameterization of the emission model and help to understand the VOCs emissions and study the precise prevention and control of complex air pollution at different times.
Predictive Value of Perioperative Cardiac Troponin I in Patients Undergone Liver Transplantation: A Retrospective Cohort Study

Objective To examine the change rule and clinical significance of cardiac troponin I (cTnI) in the perioperative period of liver transplantation in adults, as well as its association with 28-day mortality. Methods This was a retrospective cohort study: patients who underwent elective orthotopic liver transplantation (OLT) in Beijing Chao-Yang Hospital between June 2015 and June 2020 were selected, and plasma cTnI values were collected through the electronic medical record system within 7 days after surgery. Furthermore, the baseline clinical data of these patients were collected, and the change curve of cTnI values following liver transplantation was plotted. Using univariate and multivariate logistic regression models, the relationship between the level of postoperative cTnI and short-term mortality was investigated. The primary study endpoint was mortality within 28 days after surgery. Results We included 414 patients who had undergone liver transplantation in this study, 48 of whom died within 28 days after surgery. cTnI, a specific marker of myocardial injury, could predict that the postoperative cardiovascular complications were higher in the death group and significantly affect the short-term prognosis of patients; however, its prognostic cut-off value was approximately 0.545 ng/mL (13×URL), indicating that a minor elevation of cTnI after liver transplantation did not significantly affect the prognosis. Moreover, a comparison of the baseline data and postoperative ICU management scores of the two groups revealed that diabetes, maximum value of cTnI >0.545 ng/mL within 7 days, and the need for postoperative renal replacement therapy (RRT) were independent prognostic factors of death within 28 days after liver transplantation. Conclusion Within 7 days after surgery, an increase in cTnI to the maximum value of 0.545 ng/mL (13×URL) could have a significant impact on the short-term prognosis of patients. Diabetes and postoperative RRT were two independent prognostic factors for liver transplantation perioperative mortality.
New Specimen and Redescription of Anisodontosaurus greeri (Moenkopi Formation: Middle Triassic) and the Spatiotemporal Origins of Trilophosauridae

ABSTRACT Anisodontosaurus greeri is an enigmatic small-bodied tetrapod with a heterodont dentition from the Holbrook Member of the Moenkopi Formation (Middle Triassic) of Arizona (U.S.A.). The evolutionary relationships of this taxon have long been debated and remain uncertain. Using micro-computed tomography (µCT) scans we redescribe the holotype of Anisodontosaurus greeri (UCMP 37804), as well as an additional specimen (MNA.V.1478) that had been informally referred to this taxon. Our new data reveal hidden details of the dentition (i.e., ankylothecodonty and absence of replacement teeth) that, in combination with the tricuspid and mediolaterally expanded crowns, support a referral of both specimens to the archosauromorph clade Trilophosauridae. The referral of MNA.V. 1478 to Anisodontosaurus greeri is supported by the unique anatomy of the highly differentiated dentition (i.e., ‘figure of 8’-shaped premolariforms in occlusal views; mesiodistally short tooth row; presence of a distal ‘molariform’ crown). Comparison of Anisodontosaurus greeri with other trilophosaurids highlights marked similarities with Variodens inopinatus from the Upper Triassic deposits of the U.K. Our cladistic analyses confirm these observations, and recover, for the first time, two distinct lineages within Trilophosauridae: one geologically long-lived and comprising Anisodontosaurus and Variodens; and one comprising Tricuspisaurus, Trilophosaurus spp. , and Spinosuchus. These results imply that: (i) Anisodontosaurus is one of the oldest known trilophosaurids worldwide and the oldest in North America; (ii) trilophosaurids achieved a broad distribution at low latitudes within western Pangea by the Middle Triassic; (iii) small body sizes were more common than previously thought among trilophosaurids.
On some methods in half-linear asymptotic theory

We study asymptotic behavior of eventually positive solutions of the second-order half-linear differential equation $(r(t)|y'|^{\alpha-1}\sgn y')'=p(t)|y|^{\alpha-1}\sgn y$, where $r(t)$ and $p(t)$ are positive continuous functions on $[a,\infty)$, $\alpha\in(1,\infty)$. The aim of this paper is twofold. On the one hand, we show applications of a wide variety of tools, like the Karamata theory of regular variation, the de Haan theory, the Riccati technique, comparison theorems, the reciprocity principle, a certain transformation of dependent variable, and principal solutions. On the other hand, we solve open problems posed in the literature and generalize existing results. The most of our observations is new also in the linear case.
Border collision bifurcations in tantalus oscillator

The Tantalus oscillator is a nonlinear system having a stable limit cycle. In this work we analytically obtain the Phase Transition Curve (PTC) ﬁnding a one-dimensional piecewise map which has a discontinuity. The map is deﬁned by a function which was experimentally veriﬁed with an excellent consistency between theoretical and experimental results. We iterate the obtained map to predict the coupling behavior of the system under periodic perturbations, ﬁnding that it presents Periodicity Diagrams that display a high number of bistabilities. We experimentally show the occurrence of the predicted behaviors. Bifurcations among periodicities resulted Border Collision Bifurcations. Finally, by studying the Two-parametric Bifurcations Diagram we conjecture that there is at least one point in the diagram which corresponds to a Big Bang Bifurcation. This point appears when the perturbation intensity leads to the discontinuity loss in the PTC.
Old and New Results for First Order Periodic ODEs without Uniqueness: a Comprehensive Study by Lower and Upper Solutions

Abstract An elementary approach, based on a systematic use of lower and upper solutions, is employed to detect the qualitative properties of solutions of first order scalar periodic ordinary differential equations. This study is carried out in the Carathéodory setting, avoiding any uniqueness assumption, in the future or in the past, for the Cauchy problem. Various classical and recent results are recovered and generalized.
Cognitive Radar Target Tracking Using Intelligent Waveforms Based on Reinforcement Learning

Cognitive radar (CR) automatically improves itself via ceaseless interaction with the environment and learning from the experience. It continuously adjusts its waveform and parameters and illuminates strategies based on obtained knowledge to achieve robust target tracking despite complex and changing scenarios. Waveform development for CR has attracted sustaining attention in promoting tracking performance. In this article, we propose a novel framework of CR waveform selection for the tracking of high maneuvering targets in a cluttered environment with an interactive multimodel (IMM) probabilistic data association (PDA) algorithm. Based on this framework, criterion-based optimization (CBO) and entropy-rewarded Q-learning (ERQL) methods are designed to perform waveform selection, which is divided into pure parameters selection and joint selection of waveforms and parameters. This method integrates the radar target into a closed loop and realizes the real-time update of the transmitted waveform with the change of the target state, to achieve the best tracking performance of the target. The simulations performed on radar target tracking have demonstrated that the proposed ERQL method outperforms the existing method in both time complexity and tracking accuracy. Furthermore, field experiments have confirmed that the ERQL method is more effective in target tracking than the existing method.