Miracle-dz/UniFAR-FTUs huggingface dataset:
Robust stability of time-delay systems

There are two fundamental results available when we study stability of a polynomial family that is described by convex polytope in the coefficient space: the edge theorem and the theory based on the concept of convex directions. Many known results can be explained with these two results. This paper deals with a generalization of this line of research to the case of quasipolynomials that are entire functions which include both degree of the independent variable and exponential functions. The main objects of the paper are the developing of the concept of convex directions for quasipolynomials and exploiting this concept for construction of testing sets for quasipolynomial families. One of the primary sources of motivation for the class of problems considered in this paper is derived from process control. A typical problem formulation almost always includes a delay element in each subsystem process block. When we interconnect a number of such blocks in a feedback system, the study of robust stability involves quasipolynomials of the sort considered in this paper. >
InP-based reversed-mesa ridge-waveguide structure for high-performance long-wavelength laser diodes

A novel structure for an InP-based ridge-waveguide (RWG) laser is demonstrated. It has a reverse-trapezoid-ridge shape which offers reduced threshold current and smaller electrical and thermal resistances over the conventional vertical-mesa (VM) RWG devices. We found this new RWG laser quite suitable for wide-temperature-range and high-power operations. 1.3-1.55-/spl mu/m wavelength strained InGaAsP-InP multiple quantum-well (MQW) lasers were demonstrated with the new ridge structure, which showed sufficient lasing behavior such as high-temperature lasing up to 165/spl deg/C and a high light output over 300 mW. This simple and high-performance laser structure was also applied for integrated lasers with other functional elements such as an absorption-type modulator or a beam-expander waveguide lens. To achieve low-threshold current operation in RWG lasers, suppression of the lateral-current spreading is important. We proposed a new method to effectively reduce this lateral diffusion current by using a doped active region with n-type dopant. Combined by the reduced transparency carrier density in the n-doped active region, this leads to a very low-threshold current of less than 2.2 mA for a coated 200-/spl mu/m-long cavity device, which is comparable to those of recent advanced same-material buried-heterostructure (BH) lasers. These excellent lasing properties, along with the sufficient device reliability under strict environmental conditions, make this reversed-mesa (RM) RWG a promising candidate for the widespread use of low-cost long-wavelength light sources.
Analysis of Unsteady Rotor–Stator Flow with Variable Viscosity Based on Experiments and CFD Simulations

In recent years, computational fluid dynamics (CFD) has been widely used in calculating flow characteristics and heat–flow coupling. However, heat generated during fluid transportation is always ignored and the density and viscosity of the working medium are supposed to be constant. In this article, heat generation was taken into consideration. Accordingly, the thermophysical properties working of the medium are variable. A typical rotor–stator fluid machine, a hydraulic retarder, was chosen to investigate the relationship between the heat transfer characteristics of the fluid and the braking torque. The conclusions were obtained by analyzing the flow conditions which involved Re, vorticity, and rothalpy in the flow passage and viscous dissipation. When the viscous dissipation generated heat in the passage, temperature was increased and viscosity was decreased, thus accelerating the development of turbulence. Moreover, Re was increased at the same time. Furthermore, the dissipation of vorticity was reduced constantly and rothalpy reduced. The braking torque was decreased finally because the wall shear stress was decreased. The conclusions in this article are of practical significance for forecasting other turbomachine characteristics.
The Resilience of South African School Teachers in the Time of COVID-19: Coping with Risk of Infection, Loneliness, and Anxiety

The COVID-19 pandemic precipitated an overall increase in the global prevalence of mental health disorders and psychological distress. However, against this backdrop, there was also evidence of adaptation and coping, which suggested the influence of protective factors. The current study aims to extend previous research on the role of protective factors by investigating the health-sustaining and mediating roles of resilience in the relationship between perceived vulnerability to disease, loneliness, and anxiety. Participants consisted of a convenience sample of schoolteachers (N = 355) who completed the Perceived Vulnerability to Disease Questionnaire, the short form of the Connor–Davidson Resilience Scale, the University of California, Los Angeles Loneliness Scale, and the trait scale of the Spielberger State-Trait Anxiety Scale, through an online link created with Google Forms. The results of path analysis indicated significant negative associations between resilience and both loneliness and anxiety. These results indicate the health-sustaining role of resilience. In addition, resilience mediated the relationships between germ aversion and perceived infectability, on the one hand, and loneliness and anxiety, on the other hand. The findings confirm that resilience can play a substantial role in counteracting the negative impact of the pandemic on mental health.
Nonlinear Parabolic Equations with Measure Data

In this paper we give summability results for the gradients of solutions of nonlinear parabolic equations whose model isu′−div(|∇u|p−2∇u)=μonΩ×(0,T), (P)with homogeneous Cauchy–Dirichlet boundary conditions, wherep>1 andμis a bounded measure on Ω×(0, T). We also study how the summability of the gradient improves if the measureμis a function inLm(Ω×(0, T)), withm“small. ” Moreover we give a new proof of the existence of a solution for problem (P).
A study of three-dimensional aspects of vortex shedding from a bluff body with a mild geometric disturbance

Experiments have been carried out to study the three-dimensional characteristics of vortex shedding from a half-ellipse shape with a blunt trailing edge. In order to control the occurrence of vortex dislocations, the trailing edges of the models used were constructed with a series of periodic waves across their spans. Flow visualization was carried out in a water tunnel at a Reynolds number of 2500, based on trailing-edge thickness. A number of shedding modes were observed and the sequence of mode transitions recorded. Quantitative data were obtained from wind tunnel measurements performed at a Reynolds number of 40000. Two shedding frequencies were recorded with the higher frequency occurring at spanwise positions coinciding with minima in the chord. At these same positions the base pressure was lowest and the vortex formation length longest. Arguments are put forward to explain these observations. It is shown that the concept of a universal Strouhal number holds, even when the flow is three-dimensional. The spanwise variation in time-average base pressure is predicted using the estimated amount of time the flow spends at the two shedding frequencies.
Diffusion and propagation characteristics of buried single-mode waveguides in glass

Diffusion and propagation characteristics of single-mode shallow buried planar waveguides fabricated by purely thermal back diffusion of K/sup +/ ions in soda-lime glass are presented. The refractive index profile is determined using scanning electron microscopy and theoretically modeled by a Rayleigh function after solving the diffusion equation numerically. The dispersion curves are computed by solving the Helmholtz equation with a Runge-Kutta procedure and agree well with measured mode indexes. A decrease in the birefringence of the waveguides is observed by increasing the back diffusion time. Measured propagation losses remain less than 1.0 dB/cm for short back diffusion times at a wavelength of 0.633 mu m. >
On Identities of a Ternary Quaternion Algebra

This article studies a simple 4-dimensional ternary algebra 𝒜 which appears analogously to the quaternions from the Lie algebra 𝔰𝔩(2). We describe the heights 1 and 2 identities, and the derivations of 𝒜. Based on 𝒜, some ternary enveloping algebras for ternary Filippov algebras are constructed.
Extratropical forcing of tropical convection in a northern winter simulation with the UGAMP GCM

The role of the extratropics in determining the distribution of tropical convection and its inherent time‐scales has been investigated, using results from a perpetual January integration of the UK Universties Global Atmospheric Modelling Programme (UGAMP) General Circulation Model. This study has concentrated on the influence of upper tropospheric extratropical troughs in the Pacific waveguide, and of the east Asian cold surge events. The mechanisms through which the extratropics influence the model's tropical convection have been identified, and the validity of the model's behaviour has been assessed by comparing the results with previous observational studies.
Tensor product systems of Hilbert modules and dilations of completely positive semigroups

In this paper we study the problem of dilating unital completely positive (CP) semigroups (quantum dynamical semigroups) to weak Markov flows and then to semigroups of endomorphisms (E0-semigroups) using the language of Hilbert modules. This is a very effective, representation free approach to dilation. In this way we are able to identify the right algebra (maximal in some sense) for endomorphisms to act. We are led inevitably to the notion of tensor product systems of Hilbert modules and units for them, generalizing Arveson's notions for Hilbert spaces. In the course of our investigations we are not only able to give new natural and transparent proofs of well-known facts for semigroups on , but also extend the results immediately to much more general setups. For instance, Arveson classifies E0-semigroups on up to cocycle conjugacy by product systems of Hilbert spaces.5 We find that conservative CP-semigroups on arbitrary unital C*-algebras are classified up to cocycle conjugacy by product systems of Hilbert modules. Looking at other generalizations, it turns out that the role played by E0-semigroups on in dilation theory for CP-semigroups on is now played by E0-semigroups on , the full algebra of adjointable operators on a Hilbert module E. We have CP-semigroup versions of many results proved by Paschke27 for CP maps.
Listening to Their Nights: Sleep Disruptions in Captive Housed Chimpanzees Affect Their Daytime Behavior

Simple Summary Ensuring proper sleep is essential for the health of all animals, including chimpanzees. Many studies have demonstrated that sleep plays a crucial role in physical and behavioral regulation, and sleep disruptions may cause negative consequences for both. This study explores how environmental conditions and nocturnal disturbances affect the sleep and daytime behavior of sanctuary-housed chimpanzees, respectively. Our results indicate that indoor temperature and humidity affect chimpanzee nocturnal activity. Furthermore, the frequency and intensity of nocturnal disturbances influence the chimpanzee’s behavior the following day, i.e., time spent in inactivity, abnormal, self-directed, and affiliative behaviors. These findings highlight the importance of controlling factors that affect the quality of chimpanzees’ sleep at night. The use of affordable audio recordings has the potential to provide valuable information regarding the chimpanzee’s nocturnal activity and wellbeing. Abstract Chimpanzee’s nocturnal sleep is a dynamic and complex process, still not fully understood. As in humans, not getting enough quality sleep due to frequent or lasting disruptions may affect their physical and mental health, hence wellbeing, which may be reflected in their daytime behavior. This study aims to understand the impact of abiotic factors, such as temperature and humidity on the nocturnal activity as well as the impact of nocturnal awakening events on daytime behavior in sanctuary-housed chimpanzees. We monitored noisy nocturnal activity through audio recordings for one year, documenting the number and duration of sound events produced by chimpanzees to indicate sleep fragmentation and disruption intensity, respectively. Our results indicate that indoor temperature and humidity indeed influence the chimpanzee’s nocturnal activity. Furthermore, sleep fragmentation and intensity of nocturnal events significantly influenced the following day’s behavior. After nights marked by frequent and/or intense sleep disruptions, higher levels of inactivity, and abnormal and self-directed behaviors were observed, and chimpanzees spent more time on affiliative interactions and in social proximity. These findings highlight the importance of controlling factors influencing nocturnal sleep quality. Furthermore, we demonstrated that economic audio recordings used to monitor nocturnal activity, provide insights into the chimpanzee’s behavior and wellbeing.
CHALLENGES FOR COLLEGE ENGLISH TEACHERS AS ASSESSORS

The present case study aims to explore the challenges that the teachers in a Vietnamese university have faced with in the role of language assessors in their outcome-based English courses. In order to fulfil this aim, the study employs Activity Theory (Engeström, 1987, 2015) as the theoretical framework and narratives as a data collection tool. It is revealed from the three selected teachers’ narratives about their personal and professional background, the experienced reality in their assessment work that their challenges are related to inadequate assessment literacy, lack of shared knowledge and unclear assessment identity, inadequate professional training and discussions. In light of the theoretical framework (i.e., Activity Theory), these challenges result from the tensions between the subject and the rules, between the mediating artifacts and the rules, and within the division of labor. With such findings, the study is expected to raise the teachers’ and the educational managers’ awareness of the contextual conditions for better teacher assessment competence and the assessment quality in the current education reform context. Accordingly, the study proposes a framework of college English teacher professional development.
Basics of structural equation modeling

PART ONE: BACKGROUND What Does It Mean to Model Hypothesized Causal Processes with Nonexperimental Data? History and Logic of Structural Equation Modeling PART TWO: BASIC APPROACHES TO MODELING WITH SINGLE OBSERVED MEASURES OF THEORETICAL VARIABLES The Basics Path Analysis and Partitioning of Variance Effects of Collinearity on Regression and Path Analysis Effects of Random and Nonrandom Error on Path Models Recursive and Longitudinal Models Where Causality Goes in More Than One Direction and Where Data Are Collected Over Time PART THREE: FACTOR ANALYSIS AND PATH MODELING Introducing the Logic of Factor Analysis and Multiple Indicators to Path Modeling PART FOUR: LATENT VARIABLE STRUCTURAL EQUATION MODELS Putting It All Together Latent Variable Structural Equation Modeling Using Latent Variable Structural Equation Modeling to Examine Plausability of Models Logic of Alternative Models and Significance Tests Variations on the Basic Latent Variable Structural Equation Model Wrapping up
Investigation of Bubble Behavior in Subcooled Flow Boiling of Water in a Horizontal Annulus Using High-Speed Flow Visualization

Experiments have been carried out to study bubble behavior in subcooled flow boiling of water in a horizontal annulus at mass fluxes from 400 to 1200 kg/m2-s, heat fluxes from 0.1 to 1 MW/m2, and pressures varying from 1 to 4 bar using high-speed visualization methods. National Instruments Labview IMAQ Vision Builder automated image-processing software was used to analyze the images obtained by high-speed visualization to obtain bubble size and bubble density. The parametric effects of pressure, mass flux, and heat flux on bubble behavior have also been brought out. Experimental results were validated by comparing with the predicted bubble sizes by using the Zeitoun and Shoukri (1996) correlation and were found to be in good agreement. It was found that bubble behavior is significantly affected by mass flux of working fluid and applied heat flux, whereas pressure of working fluid influences the bubble formation process indirectly.
Motivations and Limitations of Pursuing a Career in Psychiatry: A Cross-Sectional Study from the United Arab Emirates

Background. The global burden of mental disorders continues to grow with significant health, social, and economic consequences. Unfortunately, the gap between the need for mental healthcare and its provision remains wide all over the world. The recruitment and retention of psychiatrists is a long-standing concern in the United Arab Emirates, with social stigma playing a potential role. This study is aimed at investigating the factors that affect psychiatrists’ choice of psychiatry as an area of practice in the United Arab Emirates. Methods. This cross-sectional study was undertaken using an anonymized 30-item online questionnaire. Ethical approval was obtained from the United Arab Emirates University Social Sciences Research Ethics Committee prior to participant recruitment. We recruited qualified psychiatrists currently working in the United Arab Emirates. The structured questionnaire assessed the participants’ sociodemographic factors and reasons for choosing psychiatry. Statistical analysis, including Pearson correlations and chi-square tests, was performed using the statistical package for the social sciences (SPSS) version 26. Results. We found that the doctors trained in the United Arab Emirates were statistically more likely to face opposition to specializing in psychiatry ( p value < 0.001). Participants with a family member or friend as a psychiatrist were more likely to choose psychiatry as a first-choice specialty ( p value 0.01). Psychiatrists below the age of 35 were more statistically likely to face opposition to their decision to specialize in psychiatry ( p value 0.006). Psychiatrists who regretted their decision to specialize in psychiatry were statistically more likely to feel this way in their first year of residency ( p value < 0.001). Conclusions. Multiple sociodemographic factors influence responses to the decision to specialize in psychiatry in the United Arab Emirates. Younger people and people who studied in or were a citizen of the United Arab Emirates were more likely to face opposition to their decision to specialize in psychiatry, indicating why there are such high rates of psychiatrists from overseas in the United Arab Emirates and shortages in the profession.
Enhancing Detection of Control State for High-Speed Asynchronous SSVEP-BCIs Using Frequency-Specific Framework

This study proposed a novel frequency-specific (FS) algorithm framework for enhancing control state detection using short data length toward high-performance asynchronous steady-state visual evoked potential (SSVEP)-based brain-computer interfaces (BCI). The FS framework sequentially incorporated task-related component analysis (TRCA)-based SSVEP identification and a classifier bank containing multiple FS control state detection classifiers. For an input EEG epoch, the FS framework first identified its potential SSVEP frequency using the TRCA-based method and then recognized its control state using one of the classifiers trained on the features specifically related to the identified frequency. A frequency-unified (FU) framework that conducted control state detection using a unified classifier trained on features related to all candidate frequencies was proposed to compare with the FS framework. Offline evaluation using data lengths within 1 s found that the FS framework achieved excellent performance and significantly outperformed the FU framework. 14-target FS and FU asynchronous systems were separately constructed by incorporating a simple dynamic stopping strategy and validated using a cue-guided selection task in an online experiment. Using averaged data length of 591.63±5.65 ms, the online FS system significantly outperformed the FU system and achieved an information transfer rate, true positive rate, false positive rate, and balanced accuracy of 124.95±12.35 bits/min, 93.16±4.4%, 5.21±5.85%, and 92.89±4.02%, respectively. The FS system was also of higher reliability by accepting more correctly identified SSVEP trials and rejecting more wrongly identified ones. These results suggest that the FS framework has great potential to enhance the control state detection for high-speed asynchronous SSVEP-BCIs.
Rapid Whole Genome Sequencing Diagnoses and Guides Treatment in Critically Ill Children in Belgium in Less than 40 Hours

Rapid Whole Genome Sequencing (rWGS) represents a valuable exploration in critically ill pediatric patients. Early diagnosis allows care to be adjusted. We evaluated the feasibility, turnaround time (TAT), yield, and utility of rWGS in Belgium. Twenty-one unrelated critically ill patients were recruited from the neonatal intensive care units, the pediatric intensive care unit, and the neuropediatric unit, and offered rWGS as a first tier test. Libraries were prepared in the laboratory of human genetics of the University of Liège using Illumina DNA PCR-free protocol. Sequencing was performed on a NovaSeq 6000 in trio for 19 and in duo for two probands. The TAT was calculated from the sample reception to the validation of results. Clinical utility data were provided by treating physicians. A definite diagnosis was reached in twelve (57.5%) patients in 39.80 h on average (range: 37.05–43.7). An unsuspected diagnosis was identified in seven patients. rWGS guided care adjustments in diagnosed patients, including a gene therapy, an off-label drug trial and two condition-specific treatments. We successfully implemented the fastest rWGS platform in Europe and obtained one of the highest rWGS yields. This study establishes the path for a nationwide semi-centered rWGS network in Belgium.
Numerical Simulations of the Steady and Unsteady Aerodynamic Characteristics of a Circulation Control Wing Airfoil

The aerodynamic characteristics of a Circulation Control Wing (CCW) airfoil have been numerically investigated, and comparisons with experimental data have been made. The configuration chosen was a supercritical airfoil with a 30 degree dual-radius CCW flap. Steady and pulsed jet calculations were performed. It was found that the use of steady jets, even at very small mass flow rates, yielded a lift coefficient that is comparable or superior to conventional high-lift systems. The attached flow over the flap also gave rise to lower drag coefficients, and high L/D ratios. Pulsed jets with a 50% duty cycle were also studied. It was found that they were effective in generating lift at lower reduced mass flow rates compared to a steady jet, provided the pulse frequency was sufficiently high. This benefit was attributable to the fact that the momentum coefficient of the pulsed jet, during the portions of the cycle when the jet was on, was typically twice as much as that of a steady jet. NOMENCLATURE