Miracle-dz/UniFAR-FTUs huggingface dataset:
Phase change materials for non-volatile electronic memories

Starting from a brief introduction into the physics of phase change materials their applications in the field of data storage are reviewed. Without the latter there would certainly be less attention paid to the topic today, even in basic research. For years now, optical data storage media based on phase change materials have been successfully produced for the mass market. Despite its maturity there are still new ideas on how to further improve this technology in order to stay competible with other storage media in the future. In contrast, for the application of phase change materials in electronic memories the situation is completely different. Although proposed decades ago, today it is still a rather young and promising technology. In this work both applications are analyzed with respect to their requirements to the incorporated phase change material, with an emphasis on the second one. For optical storage and especially in the case of electronic memories the author arrives at the conclusion, that the crystallization kinetics of phase change materials is the most urgent and fundamental problem that needs to be solved. The emphasis on a deep and quantitative understanding of this phenomenon implicitely criticizes the popular approach of studying the switching of electronic cells for phase change based memories without an in-depth research of the crystallization kinetics. After this identification of the research objective, the result of a thorough review of the literature on the theory of crystallization is presented. The understanding of glass formation turns out to be extremely important, since it deals with the stability of an amorphous solid or undercooled liquid against structural reconfiguration. Consequently, a separate chapter is dedicated to the theory of glass formation. Based on the knowledge of the theoretical connections between glass transition and crystallization it is investigated how meaningful a calculation of the enthalpy of atomization is for a prediction of stoichiometric trends not only of glass transition, but also of crystallization. The sparce experimental evidence on the glass transition temperature of phase change materials is compared to the calculated enthalpies. The same is done for a series of measurements of crystallization. These comparisons show that the proposed strategy works well for predicting the influence of a stoichiometric
Fuzzy-based power exchange management between grid-tied interconnected residential microgrids

This paper presents a fuzzy-based power exchange management between two neighboring residential grid-connected microgrids comprising both photovoltaic generation and battery energy storage system (BESS). The proposed power exchange management accounts for the magnitude of the energy rate-of-change of each microgrid and the charge difference between the BESSs of both microgrids to charge the ESS that has an energy deficit. As such, the proposed power exchange management can reduce the amount of power absorbed from the mains of each microgrid by operating jointly with each other rather than separately, and it also synchronizes the ESS of both microgrids, improving the behavior of ESSs. A comparison of the simulated results for a scenario with and without power exchange is presented in order to demonstrate the adequate behavior of the proposed power exchange management.
An Online Failure Assessment Approach for SiC-based MOSFET Power Modules Using Iterative Condition Monitoring Technique

Characterization and monitoring of the faults in Wide Bandgap-based power modules are the prerequisites to achieve robust and reliable high density power electronic design. Due to the basic differences between wide bandgap and Silicon - based power modules, applying the existing condition monitoring approaches - which are mostly designed for Silicon-based devices - does not necessarily provide the expected accuracy in these circuits. Comprehensive and accurate reliability assessment can be addressed using condition monitoring techniques, specialized for wide bandgap-based devices. Real-time observation of the switch junction temperature, as the main failure indicator, is considered in this paper, and it has led to a more accurate estimation of the switch failure rate. In this paper, employing an iterative failure rate assessment with the capability to monitor the device condition and renew the assessment in specific time intervals has addressed the required condition monitoring criteria in wide bandgap-based devices. A coupled simulation platform, consisting of PLECS, COMSOL, and MATLAB is developed to obtain the switch operational parameters during an iterative realtime process. Bayerer lifetime model is employed to estimate the switch failure rate based on the real-time switch parameters. The developed real-time iterative condition monitoring technique is tested for a 1200V/50A SiC MOSFET power module as the case study. DSPACE is employed in the experimental setup as a high bandwidth signal interface, and it was shown that by employing the proposed condition monitoring technique, the switch failure rate can be acquired based on a real-time process in order to achieve more accurate reliability assessment during the switch operation.
Mechanical Design of a Knee Prosthesis for Transfemoral Amputation

In the present investigation, the design and simulation of a polycentric knee mechanism with four-bar of voluntary control is performed, posing its mathematical model using the vector loop equation, so that its instantaneous center of rotation (CIR) meets the stability criteria established by Hosmer-Dorrance. The design of a four-bar system and the clamping for a hydraulic actuator were performed, followed by the simulation using finite elements in SolidWorks. The results obtained indicate that the maximum Von Mises tension in the four-bar mechanism is 5.161x107N/m2 and 3.834x107N/m2 in the actuator clamp, with a safety factor of the entire system greater than 1, guaranteeing to support a maximum weight of 102Kg. A prototype was built by additive and subtractive manufacturing, verifying the correct operation of the system, complying with angular displacements.
Why the Concept of Shopping Baskets helps to analyze Team-Handball

This paper summarizes the current results of a 3-year project that applies data science methods in the context of a traditional team ball game. Based on a simple model of the game it will be described how data was collected and analyzed, including a description of the concepts that have been used. An important aspect of the paper is the new perspective of looking at team-handball data. We use sport-specific events like goals and passes to analyze the stream of indicators rather than abstract concepts like the time or just the simple sequence of events. Thus, the discovered patterns become actionable for coaches.
Research on weather radar nowcasting extrapolation

The purpose of heavy rainfall forecast is to predict the distribution of local rainfall intensity in the next 0-2 hours, and the accurate extrapolation image can provide accurate spatial-temporal data reference for the nowcasting of heavy rainfall forecast. Although the accuracy of the radar extrapolation results of the deep learning model based on the recurrent network has been greatly improved compared with the traditional extrapolation model in recent two years, it still needs to be further improved in many aspects of the model. Based on the analysis of the existing ConvSLTM model and TrajGRU model of radar extrapolation, this paper improves them by increasing the number of radar layers and the weight of prediction results. Experiments are carried out with open competition data and real radar data as samples. The experimental results show that the modified network model can better capture spatiotemporal correlation and has more accurate extrapolation effect.
Delay-dependent output feedback integral sliding mode control of singularly perturbed systems

This paper presents a descriptor system method for output feedback integral sliding mode control of singularly perturbed systems. The fast state, representing the derivative of output, is approximated with aid of an artificial time-delay estimator. Then, a delay-dependent integral sliding mode controller is designed to ensure the occurrence of sliding phase since the initial time instant. The finite frequency uncertainty is divided into the matched and uncertainty uncertainty. On this basis, the proposed controller contains the nominal part to attain the robustness to the unmatched uncertainty, and the switching part to compensate the matched uncertainty. Finally, the effectiveness of the design method is verified in a mass-damper-spring system subject to finite frequency perturbations. Keywords: Sliding mode control, time delay, singular perturbation, state estimation
Expanded bed adsorption of bromelain (E.C. 3.4.22.33) from Ananas comosus crude extract

This work focuses on the adsorption of Bromelain in expanded bed conditions, such as the adsorption kinetics parameters. The adsorption kinetics parameters showed that after 40 minutes equilibrium was achieved and maximum adsorption capacity was 6.11 U per resin mL. However, the maximum adsorption capacity was only determined by measuring the adsorption isotherm. Only by the Langmuir model the maximum adsorption capacity, Qm, and dissociation constant, kd, values could be estimated as 9.18 U/mL and 0.591, respectively, at 25 oC and 0.1 mol/L phosphate buffer pH 7.5. A column made of glass with an inner diameter of 1 cm was used for the expanded bed adsorption (EBA). The residence time was reduced 10 fold by increasing the expansion degree 2.5 times; nonetheless, the plate number (N) value was reduced only 2 fold. After adsorption, the bromelain was eluted in packed bed mode, with a downward flow. The purification factor was about 13 fold and the total protein was reduced 4 fold. EBA showed to be feasible for purification of bromelain.
Harmonic Excitation Concepts for Wound-Rotor Synchronous Machines with Power-Electronics on the Rotor

In this work, a brushless, harmonic-excited wound-rotor synchronous machine is investigated which utilizes special stator and rotor windings. The windings magnetically decouple the fundamental torque-producing field from the harmonic field required for the inductive power transfer to the field coil. In contrast to conventional harmonic-excited synchronous machines, the whole winding is utilized for both torque production and harmonic excitation such that no additional copper for auxiliary windings is needed. Different rotor topologies using rotating power electronic components are investigated and their efficiencies have been compared based on Finite-Element calculation and circuit analysis.
Bayesian Optimized XGBoost Model for Traffic Speed Prediction Incorporating Weather Effects

Accurate traffic speed prediction is essential to devise traffic control strategies, travelling plans, identifying congestion, reducing travel times and related intelligent decision making. Large amounts of historical traffic speed and weather data contain complex non-linear interdependencies, but at the same time, incorporating weather effects in short to medium term travel speed prediction has been much less explored in the existing literature. With the growth in the amount of traffic speed-related data, tree-boosting algorithms like XGBoost have empirically proven to be very efficient for predictive modeling. However, this algorithm necessitates several hyperparameters to be optimized and searched in a whole complex parameter space. Moreover, using the traditional grid and random search is computationally expensive and an inefficient way in the context of traffic Big data sets. To address these challenges we propose an approach using a Bayesian-based Optimization for systematic exploration of the complex parameter space and including of weather conditions variables. Experiments were conducted using travel speed data collected through speed detectors and weather information for Manhattan, New York. Extensive data preprocessing, missing value imputation, feature selection using sequential feature selection and Bayesian optimization were implemented. The results demonstrated that the proposed approach is able to extract complex patterns from multivariate data comprising speed and weather variables lags for a more accurate prediction, particularly for medium-range horizon.
Factors Affecting Intention to Use of Government Websites in Thai Elder: The Webqual Model

The main objective of this research is to identify factor affecting the intention to use of government websites among Thai Elderly. The proposed model was framed by the Webqual conceptual framework. From the literature review we were able to identify 7 factors, namely Completeness of Information, Tailored Communication, Navigation, Ease of Understanding, Multimedia, Trust and Response time. We argue that these factors directly influence elder people’s intention to use government websites in Thailand. The data were collected with a questionnaire asking 250 elders in Thailand. A total of 88 valid questionnaire copies were analyzed using multiple regression analysis. The results suggest that Completeness of Information, Tailored Communication and Trust are significantly and directly affect Thai elders’ intention to use government website. These could help the government in their effort to digitalization the services and improve the accessibility and quality of services for elder people in Thailand.
A New Four-Layer Inverse Scale Height Grid Model of China for Zenith Tropospheric Delay Correction

To reduce the convergence time in the real-time precise point positioning (PPP), the zenith tropospheric delay (ZTD) needs to be modeled with high accuracy and sent to the users to be introduced as a priori value. Because of the height difference between the model height and user’s location, the ZTD at the model height must be converted to that at the user’s height. Therefore, it is crucial to investigate an optimal method for this height correction of ZTD. It is normally assumed that the ZTD decreases exponentially with the altitude and an empirical decrease factor is adopted for depicting the ZTD variation with altitude. In this study, the performance of the commonly used single-layer model of the decrease factor was investigated. Based on the investigation of the single-layer model, a new four-layer grid model ( $0.25^{\circ }\times 0.25^{\circ }$ ) over China was constructed with 10-year (from 2009 to 2018) ERA5 data, and its performance was validated. The results indicate that the newly constructed four-layer model has a better performance than the single-layer model with the bias and root mean square (RMS) of the determined ZTD reduced by 54.4% and 27.6%, respectively. With the four- and single-layer grid model and GNSS-derived ZTD, two ZTD models i.e. four-layer ZTD and single-layer ZTD were constructed over China. The experiment shows that the convergence time of PPP can be obviously reduced when introducing these two ZTD models and the four-layer ZTD model has a much better performance than the single-layer ZTD, especially at stations with a high altitude.
Re-examination of Vth Window and Reliability in HfO2 FeFET Based on the Direct Extraction of Spontaneous Polarization and Trap Charge during Memory Operation

We re-examine the dominant factors of the memory window (MW) and reliability of HfO<inf>2</inf> FeFET using a new technique to extract both spontaneous polarization <tex>$(\mathrm{P}_{\mathrm{s}})$</tex> and interface trap charges <tex>$(\mathrm{Q}_{\mathrm{t}})$</tex> by one-time current measurement of an FeFET during the memory operation. FeFET characteristics are strongly affected by unstable <tex>$\mathrm{Q}_{t}$</tex> (unrelated to ferroelectric) which causes <tex>$\mathrm{V}_{\mathrm{th}}$</tex> instability just after programming, and stable <tex>$\mathrm{Q}_{1}$</tex> which compensates most of electric(E)- field generated by <tex>$\mathrm{P}_{\mathrm{s}}$</tex>. Stable <tex>$\mathrm{Q}_{\mathrm{t}}$</tex> is coupled to <tex>$\mathrm{P}_{\mathrm{s}}$</tex> with constant ratio (~90%), and reduce MW to the value much lower than the coercive voltage <tex>$(\mathrm{V}_{\mathrm{c}})$</tex> limitation. Unlike the conventional model, <tex>$\mathrm{P}_{\mathrm{s}}$</tex> increase and stabilization are still effective to improve MW and retention, respectively. During cycling, MW is degraded by <tex>$\Delta \mathrm{P}_{\mathrm{s}}$</tex> reduction as well as the increase of the compensation ratio <tex>$(\Delta \mathrm{Q}_{\mathrm{t}}/\Delta \mathrm{P}_{\mathrm{s}})$</tex> which can be mitigated by suppressing charge injection/ejection via interfacial <tex>$\mathrm{SiO}_{2}$</tex>.
Success Factors Influencing Citizens’ Adoption of IoT Service Orchestration for Public Value Creation in Smart Government

Digitization and lightning expansions in digital technology have made it possible to collect data on almost anything, making it easier to quantify and integrate the collected data. The diffusion of IoT technologies has fostered the government-citizen relationship, creating a powerful argument for public value creation. Thus, IoT service orchestration can influence the development and trustworthiness of intention to use behavior. This study aims to explore the success factors of IoT service orchestration to create public value in smart government by integrating ISST and cognitive trust into TAM. Based on the literature and research outcomes, a comprehensive IoT-based Public Value Model (IoT-PVM) was developed to provide a complete picture of system success. This conceptual model is validated analytically through a quantitative method using PLS-SEM. The findings highlight that IoT service orchestration can enable the government to deliver public value, just as public trust has a parental role in building citizens’ positive behavior intentions towards the use of IoT in e-government services. The model explains 71.8% variance in perceived ease of use, 59.7% in public trust, 62.6% in perceived usefulness, 61.9% in usage behavior intention, and 69.8% of public value creation. The study results and discussion offer valuable insights regarding the public value creation of IoT-empowered public services and also contribute to academic research literature and are practically helpful for policymakers for designing IoT service orchestration and making government smarter, more transparent, and responsive to citizens.
Optimal Rotor Bars Number in Four Pole Cage Induction Motor with 36 Stator Slots—Part II: Results

The identification of the optimal number of rotor bars in grid-fed, four-poles, three-phase cage induction motor is addressed in this two-part work for the frequent case of 36 stator slots. The optimization criterion being adopted is the minimization of the electromagnetic torque pulsations in fullload steady-state conditions. In Part I of the work a parameterized winding function (PWF) model was successfully validated through commercially available finite element software. In this Part II of the work, electromagnetic torque is investigated using the validated PWF model as it allows for investigating a wide range of design alternatives in a very short time, taking into account the skewing of rotor bars. Electromagnetic pulsations for different continuously changed number of rotor bars in a rather wide range are numerically evaluated using the torque ripple factor as a performance index. The evaluation is applied to both possible practical cases of unskewed rotor bars and rotor bars that are skewed by one stator slot pitch.
The effect of TEE on treatment change in patients with acute ischemic stroke

Background and purpose Ischemic stroke is a widespread disease carrying high morbidity and mortality. Transesophageal echocardiography (TEE) is considered an important tool in the work-up of patients with acute ischemic stroke (AIS) and transient ischemic attack (TIA) patients; its utility is limited by a semi-invasive nature. The purpose of this study was to evaluate the probability of treatment change due to TEE findings (yield) in the work-up of AIS and TIA patients. Methods Retrospective data on patients with AIS or TIA who underwent TEE examination between 2000–2013 were collected from the institutional registry. Results The average age of 1284 patients who were included in the study was 57±10.4, 66% of patients were male. The most frequent TEE findings included aortic plaques in 54% and patent foramen ovale (PFO) in 15%. TEE findings led to treatment change in 135 (10.5%) patients; anticoagulant treatment was initiated in 110 of them (81%). Most common etiology for switch to anticoagulation was aortic plaques (71 patients); PFO was second most common reason (26 patients). Significant TEE findings (thrombus, endocarditis, tumor) were found in 1.9% of patients, they were more common in young patients (<55; 56% of the patients). Conclusions The beginning of anticoagulation treatment in patients with thick and complicated plaques was found frequently in our study. Significant TEE findings, were infrequent, constituted an absolute indication for treatment change and were more common in younger patients.
Social Reward, Punishment, and Prosociality in Paranoia

Paranoia is the exaggerated belief that harm will occur and is intended by others. Although commonly framed in terms of attributing malicious intent to others, recent work has explored how paranoia also affects social decision-making, using economic games. Previous work found that paranoia is associated with decreased cooperation and increased punishment in the Dictator Game (where cooperating and punishing involve paying a cost to respectively increase or decrease a partner’s income). These findings suggest that paranoia might be associated with variation in subjective reward from positive and/or negative social decision-making, a possibility we explore using a preregistered experiment with U.S.-based participants (n = 2,004). Paranoia was associated with increased self-reported enjoyment of negative social interactions and decreased self-reported enjoyment of prosocial interactions. More paranoid participants attributed stronger harmful intent to a partner. Harmful intent attributions and the enjoyment of negative social interactions positively predicted the tendency to pay to punish the partner. Cooperation was positively associated with the tendency to enjoy prosocial interactions and increased with participant age. There was no main effect of paranoia on tendency to cooperate in this setting. We discuss these findings in light of previous research.
Social Enhancement and Compensation in Online Social Support among Cancer Patients: The Role of Social Network Properties

ABSTRACT Although several researchers have reported evidence that the benefits of Internet use depend on users’ offline resources, the factors responsible for this phenomenon are not well understood. We examined a network-based explanation for social enhancement (i.e., rich get richer) and social compensation (i.e., poor get richer) in the context of received social support among adults coping with cancer. After first controlling for support received offline, we tested the role of two offline network properties in predicting support received online. The results were mostly consistent with social enhancement. Offline group affiliation was associated with greater levels of support received online. Additionally, significant indirect effects were observed from offline group affiliation to support received online through online group affiliation as well as from offline tie strength to support received online through online tie strength.