Miracle-dz/UniFAR-FTUs huggingface dataset:
Distributed Event-Triggered Secondary Control for Islanded Microgrids With Disturbances: A Hybrid Systems Approach

This paper focuses on the event-triggered secondary control problem of islanded microgrid with nonlinear dynamics and unknown external disturbances. Distributed secondary control law is proposed to compensate for frequency and voltage deviation caused by primary control, and to realize accurate active power sharing. In order to save communication resources, a novel hybrid event-triggering mechanism (ETM) is proposed to schedule the information transmission for each distributed generator. A hybrid model is constructed to describe the closed-loop dynamics and incorporate the ETM into flow and jump sets. Based on this model, Lyapunov stability conditions and ETM design are developed. Compared with the existing results, the proposed hybrid event-triggered control strategy not only has potential to reduce triggering number, but also guarantee a strictly positive minimum event-triggering interval even in the presence of external disturbances, that is important for physical implementation. Finally, simulation results are provided to illustrate the proposed method.
On measures with the doubling condition

The author characterizes metric spaces that carry a nontrivial measure with the doubling condition 0 \qquad \mu(B(x, 2R)) \le C \mu(B(x, R)), $ SRC=http://ej.iop. org/images/0025-5726/30/3/A10/tex_im_1034_img3. gif/> where . In particular, such a measure exists on any compact set in . Bibliography: 14 titles.
Interstellar dust from the Milky Way to the Magellanic Clouds

Interstellar dust in the Magellanic Clouds, with a weak or nearly absent 2175 A extinction feature, may be of interest in studies of galaxies in early stages of chemical evolution. To this inquiry, we extend the graphite-silicate grain model, introduced by Mathis, Rumpl, and Nordsieck and developed by Draine and Lee (1984) from the Milky Way to the Magellanic Clouds. We find that the empirical extinction curves in the Large and Small Magellanic Clouds can be reproduced by adjusting only the relative abundances of graphite and silicate grains, while leaving all other model properties fixed to those appropriate for the Galactic extinction curve. Using the graphite-silicate models, we calculate the absorption and scattering optical depths, the mass-density ratio of interstellar dust to neutral hydrogen, and the Kramers-Kronig relation for all three galaxies. We also present a fitting function for the three extinction curves, valid not only over the observed range of wavelengths but also over the full range as predicted by the models. All the quantities we derived here are independent of the dust-to-gas ratios in the Milky Way and the Magellanic Clouds, and can be applied to other galaxies if they contain Galactic or Magellanic-type dust.
On Semi-Global Exponential Stability Under Sampling for Locally Lipschitz Time-Delay Systems

In this article, the stability preservation problem for locally Lipschitz nonlinear time-delay systems, by emulation of continuous-time dynamic output feedback controllers, is studied. Sufficient Lyapunov-like conditions are provided such that, by suitably fast sampling, the Euler emulation of continuous-time dynamic output feedback controllers ensures the semiglobal exponential stability of the related sampled-data closed-loop system. If other emulation schemes than the Euler one are used, practical semiglobal exponential stability is guaranteed, with arbitrarily small final target ball, by suitably fast sampling. The intersampling system behavior, as well as time-varying sampling intervals, is taken into account. In the provided results, the delay-free case is included as a special case. The practical applicability of the provided results is shown through the study of a nonlinear chemical reactor system with recycle and a glucose–insulin system.
Drag prediction, decomposition and visualization in unstructured mesh CFD solver of TAS‐code

The accuracy of drag prediction in unstructured mesh CFD solver of TAS (Tohoku University Aerodynamic Simulation) code is discussed using a drag decomposition method. The drag decomposition method decomposes total drag into wave, profile, induced and spurious drag components, the latter resulting from numerical diffusion and errors. The mesh resolution analysis is conducted by the drag decomposition method. The effect of an advanced unstructured mesh scheme of U‐MUSCL reconstruction is also investigated by the drag decomposition method. The computational results show that the drag decomposition method reliably predicts drag and is capable of meaningful drag decomposition. The accuracy of drag prediction is increased by eliminating the spurious drag component from the total drag. It is also confirmed that the physical drag components are almost independent of the mesh resolution and scheme modification. Copyright © 2007 John Wiley & Sons, Ltd.
A Large-Stroke Tip-Tilt-Piston Micromirror with Electromagnetic Actuators Based on Metallic Glass

An electromagnetically driven 3-DOF (Degrees of Freedom) micromirror with a large stroke is presented. The stroke reaches the highest level of electromagnetic micromirrors with a tilting angle control mechanism, which allows spectrometers to achieve higher resolution. This research employs a novel actuation structure made of a unique material, metallic glass. It is the first attempt to integrate two functional elements, an electromagnetic actuation element and a mechanical supporting structure, into a single-layer spring made of metallic glass. The fabricated device achieves ±400 μm stroke, providing higher performance and robustness for micro-interferometer applications.
A Study on the Customer Buying Behaviour on E-Commerce Websites with Respect to Electronics during Covid-19

During Covid 19, except for essential commodities, all physical outlets were shut, and e-commerce played an important role in catering electronics products to consumers. The factors taken into consideration were Income, Occupation, Education, Gender, Age, and Experience with respect to the customer buying behaviour. An overall study reveals that experience in using e-commerce websites is a major factor influencing customer buying behaviour, and other factors such as income, occupation, education, gender, and age do not have any effect on the buying decision. The inferences are, to a large extent, in the interest of e-commerce providers whose structure of the business solely relies on the behaviour of e-customers. The study attempts to analyze the influence of the extent of consumer buying behaviour during Covid 19 for e-commerce electronics products. This paper tests that e-com shopping was raised due to the coronavirus.
White Flies and Black Aphids Detection in Field Vegetable Crops using Deep Learning

Digital image processing for the early detection of plant pests as insects in vegetable crops is essential for plant's yield and quality. In recent years, deep learning has made strides in the digital image processing, opening up new possibilities for pest monitoring. In this paper, state-of-the-art deep learning models are presented to detect common insect pests in vegetable cultivation named whiteflies and black aphids. Due to the absence of data sources addressing the aforementioned insect pests, adhesive traps for catching the target insects were used for the creation of an annotated image dataset. In total 225 images were collected, and 5904 insect instances were labelled by expert agronomists. This dataset faces many challenges such as the tiny size of objects, occlusions and resemblance. Object detection models were used like YOLOv3, YOLOv5, Faster R-CNN, Mask R-CNN, and RetinaNet as baseline algorithms for benchmark experiments. For achieving accurate results, data augmentation was used. This study has addressed these challenges by applying deep learning models which are able to deal with tiny object detection ascribed to very small insect size. The experiment results exhibit a mean Average Precision (mAP) of 75%. Dataset is available for download at https://zenodo.org/record/7139220
Comparison of time-frequency distributions for Doppler spectral estimation

The time-frequency distribution (TFD) of Doppler blood flow signals is usually obtained using the spectrogram, which requires signal stationarity and is known to produce large estimation variance. The authors examine three alternative, nonstationary spectral estimators: the Choi-Williams distribution (CWD), the Bessel distribution (ED) and the novel, adaptive-Q distribution (AQD) for their applicability to Doppler ultrasound. A synthetic Doppler signal, simulating the nonaxial and pulsatile flow of the common carotid artery, was used as the test signal. The theoretical distribution was compared to each technique, with the cross-correlation (/spl rho/) and the root-mean-square-error (RMSE) providing a quantitative assessment. The AQD had the lowest RMSE and the highest /spl rho/ of all the TFDs, while the CWD and the ED were very similar and better than the spectrogram (but both were prone to low-level noise). In conclusion, the AQD performed better than the traditional spectrogram and the other TFDs, but it was more computationally demanding.
Comment on “The electron glass in a switchable mirror: relaxation, ageing and universality”

A simple explanation for the logarithmic ageing of the photoconductivity in YH3−δ is proposed. We show that the scaling (‘simple’ ageing) of the relaxation response with the illumination time tw is consistent with the superposition of independently relaxing excitations with time offsets distributed over a window of width tw.
A Microfabricated Diamond Quantum Magnetometer with Picotesla Scale Sensitivity

This research reports a microfabricated diamond quantum magnetometer based on ensemble nitrogen-vacancy (NV) centers. The sensor device is fabricated with a standard MEMS process and integrated with optical fiber and photodiode (PD). The sensitivity of the sensor and signal-to-noise ratio (SNR) are determined by the detection efficiency of photons emitted from NVs in bulk diamonds. The miniaturized and portable diamond sensor shows a 132-fold enhancement of fluorescence collection efficiency over the fiber confocal system and an unshielded sensitivity of 334 pT•Hz-1/2 under ambient conditions. The essential sensor component is 1×1×0.1 cm3 in volume. Sensors with improved integration and sensitivity are possible to be used for practical applications, such as magnetocardiography and precision current sensing.
On metabelian groups of prime-power exponent

Meier-Wunderli has shown that every metabelian group of exponent p is nilpotent. Here we show that the subgroup generated by pk-1th powers of elements in a metabelian group of exponent pk is nilpotent. We also obtain some information on the subgroup generated by pk-2th powers. Finally we obtain a bound for the nilpotency class of n-generator metabelian groups of exponent pk.
3D Spatial Focal Control by Arrayed Optofluidic Prisms

A new 3D focal control system composed of arrayed optofluidic prisms is presented. Through dynamic control of the fluid-fluid interface via electrowetting, incoming rays are spatially steered to achieve 3D focal control. Analytical study identifies the prism angle required to obtain a focal point at P<inf>focal</inf> = (f<inf>x</inf>, f<inf>y</inf>, f<inf>z</inf>) located in 3D space. Experimentally, an arrayed system has demonstrated its 3D focal tunability along 0 ≤ f<inf>x</inf> ≤ 30, 0 ≤ f<inf>y</inf> ≤ 30, and 500 ≤ f<inf>z</inf> ≤ ∞ in millimeters. This new lens capability for 3D focal control can be potentially used for tracking eye movement for smart displays, or solar tracking for smart compact concentrated photovoltaic systems.
Green Supply Chain Management and Organizational Performance in Bahrain

This study investigates Green Supply Chain Management (GSCM) practices by exploring the level of their implementation and the relationship between seven specific GSCM practices and three organizational performance measures-economic performance, environmental performance, and operational performance- in the food and beverage (F&B) manufacturers in Bahrain. A deductive and cross-sectional approach has been used. A total of 69 responses were collected from 149 Bahraini F&B manufacturing managers using a convenience sampling method with a response rate of 61.6%. Partial least squares structural equation modeling (PLS-SEM) has been used to test the study’s hypotheses. The results showed that each of the following GSCM practices had a positive correlation to at least one of the organizational performance measures used: green purchasing (GP), cooperation with customers (CC), investment recovery (IR), green packaging (GrP), and reverse logistics (RL). However, the GCSM practices of internal environmental management (IEM) and eco-design (ED) did not show any significant relationship with organizational performance. Of the twenty-one hypotheses, seven were found to be statistically significant. The findings of this research indicate that the implementation level of GSCM is still in its early stages in Bahraini firms. Therefore, managers need to put more effort into adopting GSCM concepts efficiently in their firms.
Engagement measurement of a learner during e-learning: A deep learning architecture

Teaching in online mode is challenging, but measurement of student engagement is even more challenging and complex but crucial to overall learning of the participants. Although online environment improves the overall learning and removes the barriers of time schedules, it requires a high level of self motivation from the learners. Those at the brink of self motivation may perform exceedingly better under online learning if a tool can help them concentrate. These tools require the overall engagement level of the learner. The current manuscript proposes a multi module deep learning based engagement level predictor model. Basically, three modules, a convolutional neural network (CNN) module-for hierarchical feature extraction and other two modules-LSTM and attention based network, for temporal modeling of task are utilized in the proposed architecture. A dataset consisting of 9068 video sequences is used to measure the engagement level of the learners. The proposed model also introduced a novel cost function for prediction. Experimental results validate the usefulness of proposed loss function over traditional loss functions.
Labor-Saving Platform for Characterization of Membrane Proteins by Automated Monitoring and Data Reporting

This paper describes an automated platform for lipid bilayer studies, which dramatically reduces manual labor. Lipid bilayers are widely used to investigate the functions of membrane proteins in vitro. However, the experimental processes, such as monitoring of bilayer functionality during the experiment and analysis of protein properties after the experiment, have relied on manual labor. In this study, we propose a platform that automates the monitoring and post-analysis, which are the most critical and labor-intensive processes. The platform integrates three developed functions: (1) an acquisition system that obtains transmembrane current in real-time, (2) digital filters for the analysis of the current, and (3) a bilayer reformation system that immediately activates when the measurement failure is detected. Combining all, the platform enables automated monitoring of bilayer status, allowing us to continue the measurement for a long period without human supervision. It also allows us to automatically create reports of the analyzed data, saving the trouble of manual post-analysis. We applied the system to gather a large amount of data of α-hemolysin (αHL) to create a histogram of their electrophysiological conductance values. Not only were the values well-estimated, but the time of manual labor throughout the experiment was also reduced to 1 min, which was far less than the 2 h or more required in a conventional procedure.
Estimation of errors associated with the EarthCARE 3D scene construction algorithm

The EarthCARE satellite mission plans to perform a continuous closure experiment to assess the quality of retrieved cloud and aerosol properties. It will do so by comparing top‐of‐atmosphere (TOA) broad‐band (BB) fluxes with simulated values produced by three‐dimensional (3D) radiative transfer models that act on the two‐dimensional (2D) retrieved cross‐section and a 3D atmosphere around it produced by a scene construction algorithm (SCA). This study proposes and tests a method for estimating errors in simulated TOA BB fluxes due to the SCA.
The Relationship Between Trauma and Substance Use Among Healthcare Workers

Abstract Trauma exposure is prevalent in the general population, but healthcare workers may be at greater risks for additional work-related trauma. Trauma is a known risk factor for substance use, particularly tobacco and risky alcohol use. Few studies have examined the relationship between trauma and substance use in healthcare workers. Among healthcare workers, the aims of our study were to examine (a) frequency of current tobacco use and risky alcohol use, (b) frequency and types of traumatic experiences, and (c) the associations between trauma experiences and current tobacco and risky alcohol use controlling for demographic factors. This study is a secondary analysis of cross-sectional survey data from healthcare workers (N = 850) in an academic medical center. Demographic and work-related variables, trauma experience, and substance use were examined. Multivariate logistic regression analysis examined associations between trauma exposure and tobacco and risky alcohol use controlling for demographic and work-related variables. Nearly 75% of respondents reported at least one lifetime traumatic experience, and one in 10 reported tobacco and risky alcohol use. When controlling for demographic and work-related variables, a dose-response relationship was observed such that the higher the number of traumatic experiences, there was a greater likelihood of reporting tobacco or risky alcohol use. Because healthcare providers have additional work-related trauma risk above the public, and greater trauma is associated with increased risk for substance use, it is important to screen for trauma and provide appropriate treatment resources to healthcare providers. Future research is needed to better delineate the relationship between specific traumas and risky substance use among healthcare providers.
A population-based autopsy study

Despite numerous studies documenting the association between cancer and venous thromboembolism (VTE), the reason for the excessive risk in certain cancers remains obscure. No large-scale studies have yet investigated the independent effects of cancer type,site and growth pattern.Between 1970 and 1982, 23,796 standardised autopsies were performed, representing 84% of all in-hospital deaths in an urban Swedish population.The relationship between cancer and PE was evaluated with logistic regression.The overall PE prevalence was 23%, and 10% of the population had a fatal PE. Forty-two per cent of pancreatic cancer patients had PE (OR 2.55; 95% CI 2.10–3.09) (p<0.001); gall bladder, gastric, colorectal and pulmonary adenocarcinomas were similarly independently associated with PE. In comparison
Gap detection in a narrow band of noise in the presence of a flanking band of noise

This study examined gap detection in a narrow band of noise in the presence of a flanking band of noise which did not carry the gap. The study was motivated by the phenomenon of comodulation masking release (CMR) where coherent amplitude modulation at a distal frequency facilitates the detection of a signal at a target frequency. The results showed that gap detection in the target band of noise was disrupted by the presence of a flanking narrow band of noise, particularly if the flanking band was gated on and off synchronously with the target band. The disruption was greater for a comodulated flanking band. It was concluded that a necessary condition for the interference was either the presence of modulation or the occurrence of synchronous gating, since the interference did not occur for a continuous pure tone of equal energy. The findings were interpreted in terms of modulation detection interference (MDI).
THE ROLE OF ACTIVE REGION LOOP GEOMETRY. II. SYMMETRY BREAKING IN THREE-DIMENSIONAL ACTIVE REGION: WHY ARE VERTICAL KINK OSCILLATIONS OBSERVED SO RARELY?

We present numerical results of simulations of kink oscillations of coronal loops in an idealized active region (AR) that is initialized as a potential dipole magnetic configuration with gravitationally stratified density. We consider loops, with density higher than the surrounding plasma, embedded into the dipolar AR. We study the excitation of kink oscillations of such loops by velocity pulses at different positions, of a given duration and amplitude. The position of the pulse varies in the parametric studies. For a central (symmetric) loop within the AR, we find that the amplitude of vertical kink oscillations is significantly amplified in comparison to horizontal kink oscillations for exciters located centrally (symmetrically) below the loop. For pulses initiated further from such a symmetric loop a combination of vertical and horizontal oscillations is excited. The scenario changes significantly when we study an inclined loop (non-symmetric within a dipole field). In this case, we do not see vertical kink oscillations of any significant amplitude being excited, while horizontal ones can be easily detected. These results indicate that the reason why vertical kink oscillations are observed so rarely is that their excitation requires a set of conditions to occur simultaneously: the exciting pulse must be located roughly below the loop apex and the loop itself must be located symmetrically within the group of loops. The new findings of the present study show the importance of not only the position of the pulse, but mainly of the location of the loop within the set of field lines having the same magnetic connectivity. We find that the slow propagating wave is excited in all the studied loops and its excitation does not depend either on the geometry of the loop or the pulse. We discuss TRACE observations of coronal loop oscillations in view of our findings and find that our results can be used for identifying the polarization of the kink mode based on the location of the loop within the set of field lines of the same connectivity and the position of the flare.
Evaluation of Ice-Adhesion Strength on Erosion-Resistant Materials

Ice-adhesion properties were evaluated for coating systems based on titanium nitride applied via cathodic-arc physical vapor deposition developed for rotorcraft erosion caps. The ice-adhesion strength of titanium nitride and titanium aluminum nitride was determined experimentally and compared to the ice-adhesion strength of uncoated metallic materials currently used on rotor-blade leading-edge caps: stainless steel 430, Inconel 625, and titanium grade 2. Environmental and material parameters were investigated to identify which were most influential on impact ice-adhesion strength. The effects of median volumetric diameter of the cloud droplets, liquid water content of the cloud, ambient temperature, surface roughness, and material grain direction were tested on stainless steel 430. Tests revealed that surface roughness and temperature have the greatest effect on ice-adhesion strength. There was an increase in adhesion strength of 670% from −8 to −16 °C and 250% increase from 0.61 to 2.67Ra μm. An increas.