Miracle-dz/UniFAR-FTUs huggingface dataset:
Computational Methods for Nonlinear Systems Analysis With Applications in Mathematics and Engineering

COMPUTATIONAL METHODS FOR NONLINEAR SYSTEMS ANALYSIS WITH APPLICATIONS IN MATHEMATICS AND ENGINEERING Geoffrey Kenneth Rose Old Dominion University, 2017 Co-directors: Dr. Brett A. Newman Dr. Duc T. Nguyen An investigation into current methods and new approaches for solving systems of nonlinear equations was performed. Nontraditional methods for implementing arc-length type solvers were developed in search of a more robust capability for solving general systems of nonlinear algebraic equations. Processes for construction of parameterized curves representing the many possible solutions to systems of equations versus finding single or point solutions were established. A procedure based on these methods was then developed to identify static equilibrium states for solutions to multi-body-dynamic systems. This methodology provided for a pictorial of the overall solution to a given system, which demonstrated the possibility of multiple candidate equilibrium states for which a procedure for selection of the proper state was proposed. Arc-length solvers were found to identify and more readily trace solution curves as compared to other solvers making such an approach practical. Comparison of proposed methods was made to existing methods found in the literature and commercial software with favorable results. Finally, means for parallel processing of the Jacobian matrix inherent to the arc-length and other nonlinear solvers were investigated, and an efficient approach for implementation was identified. Several case studies were performed to substantiate results. Commercial software was also used in some instances for additional results verification.
Immersion and invariance adaptive control for discrete‐time systems in strict‐feedback form with input delay and disturbances

This work presents a new adaptive control algorithm for a class of discrete‐time systems in strict‐feedback form with input delay and disturbances. The immersion and invariance formulation is used to estimate the disturbances and to compensate the effect of the input delay, resulting in a recursive control law. The stability of the closed‐loop system is studied using Lyapunov functions, and guidelines for tuning the controller parameters are presented. An explicit expression of the control law in the case of multiple simultaneous disturbances is provided for the tracking problem of a pneumatic drive. The effectiveness of the control algorithm is demonstrated with numerical simulations considering disturbances and input‐delay representative of the application.
Flicker stabilization in image sequences

Flicker is an artefact appearing in old movies or in some videos, which is characterized by intensity changes from a frame to another. Some of these contrast changes are not global and may be localized only on a part of the image. In this paper, a new method to stabilize flicker in image sequences is proposed. This stabilization is local and relies on image patches. Local contrast changes are performed in order to equalize the grey level distribution of an image patch with the grey level distributions of all its corresponding patches in the previous and following frames. The correspondences of a patch are computed thanks to a similarity measure that is built to be robust to contrast changes.
Volunteers Motivations in Brazillian´s Mega Sporting Events: Similar or Different?

Identifying volunteer motivation is fundamental to the management of this segment in sporting events. Therefore, this present article aimed to identify if there are differences among volunteer motivation between two mega sporting events held in Brazil. The empiric part of this article had the lócus of Formula 1 Grand Prix held in Interlagos in the city of São Paulo in the year 2018 and the Olympic Games held in Rio de Janeiro in 2016. Data for this research have been collected using a questionnaire based upon the theoretical model of Bang and Chelladurai (2009) and Bang et al. (2009). It used the quantitative research method, encompassing the application of 600 forms to the volunteers involved in the events, with 400 in the Olympics and 200 in the Formula 1. The research showed that motivations are different, depending upon the type of sporting event held in Brazil. The more specific the sporting event, in the case of Formula 1, the more is the affinity shown by the volunteer with the event, contributing, above all in the withholding of these volunteers.
Low-Profile Four-Port Patch Antenna With Wide Isolation Bandwidth and Same Polarization: Principle and Design Approach

In this letter, a low-profile four-port microstrip patch antenna (MPA) with a wide isolation bandwidth and same polarization is proposed by using characteristic mode analysis. First, the internal electric field and modal significance (MS) of the shorted two-port MPA are theoretically studied. It shows that the null point of its internal electric field can be reallocated to the unexcited feeding port by combining different modes. As such, the specific pins1, pins2, and pins3 are loaded so as to gain three minimum poles for mutual coupling reduce. After that, the pins4 are further inserted to achieve wideband isolation and broadside-beam. In addition, ring slots are etched to improve its input impedance. In final, our proposed four-port MPA is designed and tested. The results prove that its isolation bandwidth (|S11| of -10 dB and isolation of above 20 dB) is obviously extended to about 16.2%, while keeping the broadside pattern with the same polarization. Additionally, the MPA remains low-profile (0.06λ0), single-layer, and single-radiator.
The 23–26 September 2012 U.K. Floods: Using PV Surgery to Quantify Sensitivity to Upper-Level Forcing

AbstractMajor river flooding affected the United Kingdom in late September 2012 as a slow-moving extratropical cyclone brought over 150 mm of rain to parts of northern England and north Wales. The cyclone deepened over the United Kingdom on 24–26 September as a potential vorticity (PV) anomaly approached from the northwest, elongated into a PV streamer, and wrapped around the cyclone. The strength and position of the PV anomaly is modified in the initial conditions of Weather Research and Forecasting Model simulations, using PV surgery, to examine whether different upper-level forcing, or different phasing between the PV anomaly and cyclone, could have produced an even more extreme event. These simulations reveal that quasigeostrophic (QG) forcing for ascent ahead of the anomaly contributed to the persistence of the rainfall over the United Kingdom. Moreover, weakening the anomaly resulted in lower rainfall accumulations across the United Kingdom, suggesting that the impact of the event might be proportio.
Online Switching Strategy Between Dual Three-Phase PMSM and Open-Winding PMSM

To make full use of the advantages of dual three-phase permanent magnet synchronous motor (DTP-PMSM) and three-phase open-winding permanent magnet synchronous motor (OW-PMSM), this article proposed a novel typology of the motor drive which can switch between dual three-phase (DTP) structure and three-phase open-winding (OW) structure online. On this basis, the basic control and fault-tolerant control are studied to explore the superiority of the proposed typology. Under healthy conditions, no adjustment is required for the modulation method of the proposed control scheme when switching between DTP and OW mode. By using two bidirectional thyristors, smooth switching between the two modes can be guaranteed. Besides, the power weight of two inverters can be adjusted by changing the current ratio in DTP mode and changing the voltage ratio in OW mode. For the fault-tolerant control, when an open-phase fault occurs, DTP mode will be used to provide sufficient dimensions of current control and the fault-tolerant scheme can be realized through current compensation without changing the control framework. When an open-switch fault or short-switch fault occurs, OW mode will be adopted to guarantee symmetrical phase currents, and the remaining healthy switches in the faulty inverter are fully used to share the loss of the healthy inverter. The experiment has been conducted to prove the feasibility and superiority of the proposed typology and control scheme.
Synthesis, Characterization and Biological Properties of Type I Collagen–Chitosan Mixed Hydrogels: A Review

Type I collagen and chitosan are two of the main biological macromolecules used to design scaffolds for tissue engineering. The former has the benefits of being biocompatible and provides biochemical cues for cell adhesion, proliferation and differentiation. However, collagen hydrogels usually exhibit poor mechanical properties and are difficult to functionalize. Chitosan is also often biocompatible, but is much more versatile in terms of structure and chemistry. Although it does have important biological properties, it is not a good substrate for mammalian cells. Combining of these two biomacromolecules is therefore a strategy of choice for the preparation of interesting biomaterials. The aim of this review is to describe the different protocols available to prepare Type I collagen–chitosan hydrogels for the purpose of presenting their physical and chemical properties and highlighting the benefits of mixed hydrogels over single-macromolecule ones. A critical discussion of the literature is provided to point out the poor understanding of chitosan–type I collagen interactions, in particular due to the lack of systematic studies addressing the effect of chitosan characteristics.
The effect of multiple segment interaction dynamics on elbow valgus load during baseball pitching

Elbow valgus load generated in baseball pitching is a risk factor for throwing-related injuries. However, an induced acceleration analysis establishing the cause–effect relationship between elbow valgus load and causal joint kinematics is lacking. The purpose of this study was to identify the underlying mechanism of how the elbow valgus load is generated by muscular and non-muscular interactive torque effects. The throwing motions of five fastball pitches from 16 male collegiate baseball pitchers were measured by a three-dimensional motion capture system. The induced acceleration analysis developed in this study was used to separate the elbow valgus stress of the throwers into causal muscular and interactive torque components. The results showed that the shoulder internal rotation torque-induced component was greatest, accounting for 73.0% of the valgus-related contribution, while the other joint components in the muscular and interactive torque components were relatively smaller. This implied that the elbow valgus stress was highly influenced by the internal rotation torque effect, while the motion-dependent effect due to the trunk and shoulder kinematics was not influential. In conclusion, to reduce the risk of injury, pitchers should acquire proper coordination without excessive shoulder internal rotation action.
Towards an Integrative Model of Math Cognition: Interactions between Working Memory and Emotions in Explaining Children’s Math Performance

Individual variation in mathematical skills can be ascribed to differences in cognitive ability, but also to students’ emotional experiences of mathematics, such as enjoyment and anxiety. The current study investigated how the interplay of working memory with math anxiety and enjoyment explains mathematical performance in primary school students. We also explored whether these relations differed with the type of math test and students’ age. Using mixed effect models, we reanalyzed data from 4471 Dutch primary school students (grades 2–6) who had completed two computerized working memory tasks, had filled out a questionnaire on math emotions, and had completed two math tests: story problems and speeded arithmetic. Findings showed that working memory, anxiety, and enjoyment were linear (but not curvilinear) predictors of performance on both tests, while some relations were stronger for the math (story)-problem-solving test. Higher math anxiety negatively impacted performance more strongly for students with stronger working memory skills, but only on the arithmetic test. No interaction between working memory and enjoyment was found. The relation between math anxiety and math performance increased with grade level, but no other age-related changes were found. Interpretations and recommendations focus on situated views on learning and emotion.
Instant formation of nanopores on flexible polymer membranes using intense pulsed light and nanoparticle templates

ABSTRACT The development of simple and high-throughput approaches to yield solid-state nanopores on large surface membranes may facilitate the prevalence of nanopore analysis technology and in-vitro diagnosis using portable devices. However, solid-state nanopores are typically realized by complex and high-end nanofabrication equipments. Here, we present a method to achieve nanopores on polymer membranes using silver nanoparticles (AgNPs) as templates and intense pulsed light (IPL) as a heating source. The density and size of nanopores are controllable by adjusting the spin coating rate, the concentration of nanoparticle suspension, and the size of nanoparticles (NPs). The temperature of the AgNPs can rapidly reach 1132 K under instant heating of photothermal effect through light irradiation in 2 ms, resulting in localized melting and decomposition of an underneath polycarbonate (PC) membrane to yield nanopores with sizes ranging from 10 to 270 nm. After removing the nanoparticle residues, the flexible membrane with nanopores can be integrated into a flow cell to achieve a nanopore sensor that has been used to measure the translocation behaviors of bovine serum albumin (BSA). The results have demonstrated the capability of the sensor in protein denaturation identification. This low-cost and high-throughput technique to fabricate solid-state nanopores on flexible polymeric membranes may facilitate the development of more nanopore-based flexible sensors that can be integrated with other flexible components for wearable diagnosis. GRAPHICAL ABSTRACT
Moral reasoning through the eyes of persons with behavioral variant frontotemporal dementia

Introduction Persons with behavioral variant frontotemporal dementia (bvFTD) can exhibit apparently antisocial behaviors. An example is their tendency to adopt utilitarian choices in sacrificial moral dilemmas, i.e. harmful actions to promote overall welfare. Moral cognition models interpret such tendencies as deriving from a lack of emotional engagement and selective impairment in prosocial sentiments. Methods We applied a qualitative approach to test those theoretical assumptions and to further explore the emotional experiences and values of people with bvFTD while they contemplate moral scenarios. We conducted semistructured interviews with 14 participants: 7 persons with bvFTD and 7 older healthy controls. Transcripts were coded using ATLAS.ti 5.0. Results During the moral reasoning task, persons with bvFTD reported more positive emotions than negative and showed significantly less cognitive precision in their moral reasoning compared to controls. Persons with bvFTD also organized their choices predominantly around kindness and altruism, and their responses reflected higher rule compliance. Our study showed that bvFTD persons’ utilitarian responses to moral dilemmas did not arise from an emotionally disengaged or antisocial perspective. Instead, they were underpinned by positive emotionality and prosocial values. Discussion These findings enrich current understandings of moral cognition and highlight the importance of incorporating mixed methods approaches in dementia research that take into consideration the viewpoint of cognitively impaired individuals
Thong-Bhitongan: Development of Educational Media based on Ethnomatematics of Madura Coastal Culture

This study is aimed to develop mathematics learning media inspired by the typical games of the coastal communities of Sumenep Madura Regency. We provide the media with "Thong-Bhitongan" which is defined as a counting tool in Indonesian. This development uses a development design adapted from Thiagarajan, which consists of a definition, design, and development. "Thong-Bhitongan" is a concrete media that students can play with. The validation results of the "Thong-Bhitongan" media were 82.5, and the material validation was 85. Product trials were carried out at three target schools of Kampus Mengajar 4: Duko II Elementary School, Guluk-guluk II Elementary School, and Guluk-guluk IV Elementary School. The results of the product trials showed that the "Thong-Bhitongan" learning media developed was effective in helping to increase students' understanding of numeracy material, as evidenced by the post-test results which were better than the pre-test results and had exceeded the minimum completeness score. In addition, the media "Thong-Bhitongan" also achieved a good response from students. It is expected that the product of this research, namely the mathematics learning media "Thong-Bhitongan" will become an alternative medium in improving students' nomural abilities.
Mathematical analysis of SAR imaging through a turbulent ionosphere

Synthetic aperture radar (SAR) imaging though the Earth ionosphere is subject to distortions due to ionospheric turbulence. We consider the limiting cases of small-scale and large-scale turbulence and characterize the distortions in terms of image blurring and azimuthal shift. It is shown that in the large-scale case, a high level of eikonal fluctuations can coexist with the low degree of image distortions, and that blurring becomes significant at much higher levels of fluctuations than the shift. In the small-scale case, a low level of eikonal fluctuations is a precondition for imaging, while the magnitude of distortions depends on the ratio between the eikonal correlation radius and the length of the synthetic aperture.
Comparison between process simulation and deformation measured by defocused speckle photography

Defocused laser speckle photography is used as a tool to measure the heat responses in a titanium component during laser heating. The evolution of the response is compared with a set of preprocessed Finite Element Simulations of the corresponding process with the aim to verify the simulation model and to find the simulation settings that best resemble the experimental results. The titanium component consists of a 300 x 100 mm2 substrate of thickness 3.2 mm on which a 200 x 30 x 11 mm3 ridge is built up using the laser metal deposition by wire process. The component is heated on the top of the ridge by a 300 W laser for 10 s and the deformation of the subtrate is followed throughout the heating-cooling cycle. The simulated deformation gradient is shown to resemble the measured response, and the magnitude of the response indicates that about 70 % of the laser power transferres into heat in the metal.
Recent Advances in Applying Machine Learning and Deep Learning to Detect Upper Gastrointestinal Tract Lesions

The clinical application of a real-time artificial intelligence (AI) image processing system to diagnose upper gastrointestinal (GI) malignancies remains an experimental research and engineering problem. Understanding these commonly used technical techniques is required to appreciate the scientific quality and novelty of AI studies. Clinicians frequently lack this technical background, and AI experts may be unaware of such clinical relevance and implications in daily practice. As a result, there is a growing need for a multidisciplinary, international assessment of how to conduct high-quality AI research in upper GI malignancy detection. This research will help endoscopists build approaches or models to increase diagnosis accuracy for upper GI malignancies despite variances in experience, education, personnel, and resources, as it offers real-time and retrospective chances to improve upper GI malignancy diagnosis and screening. This comprehensive review sheds light on potential enhancements to computer-aided diagnostic (CAD) systems for GI endoscopy. The survey includes 65 studies on automatic upper GI malignancy diagnosis and evaluation, which are compared by endoscopic modalities, image counts, models, validation methods, and results. The main goal of this research is to assess and compare each AI method’s current stage and potential improvement to boost performance, maturity, and the possibility to open new research areas for the application of a real-time AI image recognition system that diagnoses upper GI malignancies. The findings of this study suggest that Support Vector Machines (SVM) are frequently utilized in gastrointestinal (GI) image processing within the context of machine learning (ML). Moreover, the analysis reveals that CNN-based supervised learning object detection models are widely employed in GI image analysis within the deep learning (DL) context. The results of this study also suggest that RGB is the most commonly used image modality for GI analysis, with color playing a vital role in detecting bleeding locations. Researchers rely on public datasets from 2018–2019 to develop AI systems, but combining them is challenging due to their unique classes. To overcome the problem of insufficient data to train a new DL model, a standardized database is needed to hold different datasets for the development of AI-based GI endoscopy systems.
Lifestyle Patterns in Patients with Type 2 Diabetes

Modern lifestyles have led to sedentary behavior, lower participation in active movement and physical activities during leisure time, unhealthy diets, and increased exposure to stress. It is important to examine the interaction of several lifestyle risk factors instead of focusing on one alone. The purpose of this study was to identify lifestyle patterns in a group of patients with type 2 diabetes and the associations of its components with certain metabolic parameters. Using principal component analysis, we identified three dietary patterns: the prudent pattern (fat, oil, cereals, potatoes, vegetables, fish, nuts, seeds and fruits), the Western pattern (meat and meat products, eggs and soft drinks) and the traditional pattern (milk and its derivatives, soups and sauces, with a low intake of sugar/snacks). In addition, using the same method of analysis, we identified two lifestyle patterns: the inadequate lifestyle pattern (Western dietary pattern, increased hours of sleep and lower levels of stress) and the traditional lifestyle pattern (traditional dietary pattern, increased physical activity (PA) and non-smoking status). The inadequate lifestyle pattern was associated with younger age, hypertension and diabetic neuropathy. The traditional lifestyle pattern was related to lower postprandial blood glucose levels. Sedentary individuals were more likely to be over 65 years old and to have higher glycated hemoglobin (HbA1c). Smokers were also more likely to have inadequate glycemic and lipid profile control.
Internal wave generation by tidal flow over a two-dimensional ridge: energy flux asymmetries induced by a steady surface trapped current

The effects of a surface trapped steady background current on internal waves generated by tidal currents oscillating over a small symmetric ridge are investigated using a two-dimensional primitive equation model. A rigid lid is used with a linearly stratified fluid and the effects of rotation are not considered. We consider uni-directional background currents $\bar{U}(z)\geqslant 0$ confined to a surface layer lying well above the ridge. The current introduces asymmetries in the generated wave field. For sufficiently narrow ridges the upstream energy flux is larger than the downstream flux while the opposite is the case for sufficiently wide ridges. The total energy flux radiating away from the ridge is not significantly affected by the current. Mean second-order currents and pressure fields are shown to make important contributions to the total energy flux. A first-order linear theory, valid for a general stratification and surface current, which accurately predicts the wave field is also developed.