Miracle-dz/UniFAR-FTUs huggingface dataset:
Qualitative Analysis of the Dynamics of a Trailed Wheeled Vehicle with Periodic Excitation

This article examines the dynamics of the movement of a wheeled vehicle consisting of two links (trolleys). The trolleys are articulated by a frame. One wheel pair is fixed on each link. Periodic excitation is created in the system due to the movement of a pair of masses along the axis of the first trolley. The center of mass of the second link coincides with the geometric center of the wheelset. The center of mass of the first link can be shifted along the axis relative to the geometric center of the wheelset. The movement of point masses does not change the center of mass of the trolley itself. Based on the joint solution of the Lagrange equations of motion with undetermined multipliers and time derivatives of nonholonomic coupling equations, a reduced system of differential equations is obtained, which is generally nonautonomous. A qualitative analysis of the dynamics of the system is carried out in the absence of periodic excitation and in the presence of periodic excitation. The article proves the boundedness of the solutions of the system under study, which gives the boundedness of the linear and angular velocities of the driving link of the articulated wheeled vehicle. Based on the numerical solution of the equations of motion, graphs of the desired mechanical parameters and the trajectory of motion are constructed. In the case of an unbiased center of mass, the solutions of the system can be periodic, quasi-periodic and asymptotic. In the case of a displaced center of mass, the system has asymptotic dynamics and the mobile transport system goes into rectilinear uniform motion.
Big Techs vs Banks

We study an economy in which large technology companies, big techs, provide credit to (cid:133)rms operating on their platforms. We focus on two advantages that big techs have with respect to banks: better information on their clients and better enforcement of credit repayment since big techs can exclude a defaulting (cid:133)rm from their ecosystem. While big techs have both superior enforcement and complete and private information of the (cid:133)rm type big techs can encroach on banks(cid:146)turf only if they guarantee some privacy to (cid:133)rms by tempering their drive to collect information about (cid:133)rm characteristics and leaving some rents to them. The way big techs share information i.e
A compact single layer branch-line coupler for ultra-wideband (UWB) applications

This paper presents the design of a compact, planar, single layer, tri-section ultra-wideband (UWB) branch-line (BL) coupler. The prototype offers 10 dB return loss characteristics from 3.1 to 13.7 GHz. Over a major portion of the band, phase imbalance of ±10° is achieved. The method of deploying multi stage impedance feed has been used to achieve improved bandwidth. To enhance the power output through the coupled port throughout the operating band, ring shaped slots have been introduced in the ground plane beneath the series arms. The performance of the fabricated prototype has also been validated experimentally.
White Paper on the New ABB Medium Voltage Drive System, Using IGCT Power Semiconductors and Direct Torque Control

AbstractThis paper describes the new medium voltage PWM converter developed by ABB for driving medium voltage squirrel cage induction motors in a power range of 500 kVA to 6000 kVA. The role of the author was to witness, as an academic party, the different features that the developer-manufacturer included to come to a competitive product. The paper is built up around the technical features that the developer’s team selected to reach their objectives: three level converter topology with LC output filter and input isolation transformer, advanced thyristor technology (IGCT-Integrated Gate Commutated Thyristor), advanced control principles (DTC = Direct Torque Control) and fuseless design. The author asked the manufacturer to provide comprehensive experimental data, which are reported in this paper, to evaluate the statements and the benefits of the drive.
Modelling the Effect of Virulent Variants with SIR

We study the effect of an emerging virus mutation on the evolution of an epidemic, inspired by the appearance of the delta variant of SARS-CoV-2. We show that if the new variant is markedly more infective than the existing ones the epidemic can resurge immediately. The vaccination of the population plays a crucial role in the evolution of the epidemic. When the older (and more vulnerable) layers of the population are protected, the new infections concern mainly younger people, resulting in fewer hospitalisations and a reduced stress on the health system. We study also the effects of vacations, partially effective vaccines and vaccination strategies based on epidemic-awareness. An important finding concerns vaccination deniers: their attitude may lead to a prolonged wave of epidemic and an increased number of hospital admissions.
A simple island biodiversity model is robust to trait dependence in diversification and colonization rates

The application of state-dependent speciation and extinction (SSE) models to phylogenetic trees has revealed an important role for traits in diversification. However, this role remains comparatively unexplored on islands, which can include multiple independent clades resulting from different colonization events. Here, we perform a robustness study to identify how trait-dependence in rates of island colonization, extinction and speciation (CES rates) affects the estimation accuracy of a phylogenetic model that assumes no rate variation between trait states. We extend the DAISIE (Dynamic Assembly of Islands through Speciation, Immigration and Extinction) simulation model to include state-dependent rates, and evaluate the robustness of the DAISIE inference model using simulated data. Our results show that when the CES rate differences between trait states are moderate, DAISIE shows negligible error for a variety of island diversity metrics. However, for large differences in speciation rates, we find large errors when reconstructing clade size variation and non-endemic species diversity through time. We conclude that for many biologically realistic scenarios with trait-dependent speciation and colonization, island diversity dynamics can be accurately estimated without the need to explicitly model trait dynamics. Nonetheless, our new simulation model may provide a useful tool for studying patterns of trait variation.
Production of Microalgal Biomass at Different Growth Phases to Use as Biofuel Feedstock

The growth of microalgae under optimized conditions was determined for assessing their growth rate and biomass production. In this study, the growth of both green algae (Chlamydomonas noctigama and Chlorella vulgaris) and cyanobacteria (Anabaena variabilis and Nostoc spongiaeforme) was measured as optical density. Chlamydomonas noctigama and Chlorella vulgaris showed the doubling time of 9.5 and 8.0 hours, respectively, whereas Anabaena variabilis and Nostoc spongiaeforme showed the doubling time of 14.8 and 16.6 hours, respectively. All the species exhibited the highest growth in terms of biomass at the phase in between stationary and death phases. J. Asiat. Soc. Bangladesh, Sci. 47(2): 161-171, December 2021
INOVAÇÃO E DESEMPENHO ORGANIZACIONAL: UM ESTUDO DAS PUBLICAÇÕES CIENTÍFICAS DA BASE WEB OF KNOWLEDGE INNOVATION AND ORGANIZATIONAL PERFORMANCE: A STUDY OF SCIENTIFIC PUBLICATIONS OF THE WEB OF KNOWLEDGE BASE

The researches that discuss innovation and organizational performance are in evidence, as companies, governments and research institutions are interested in fostering scientific and technological development, thus generating results for society. However, little is known about innovation and its impact on organizational performance. Thus this paper aims to identify the subjects discussed on this topic, analyzing the publications in the Web of Knowledge database, which groups the main international journals related to innovation. This work identifies subjects that received the most attention from researchers and was organized as a bibliometric research based on 488 selected articles. Using the Alceste software, two thematic groups were identified, one focusing on methodological aspects of innovation indicators, and the other focusing on human, social, economic and strategic aspects of innovation and organizational performance.
Improved homogenization procedure based on a Drude–Lorentz dispersive model for metamaterials

The extraction of constitutive parameters of metamaterials, i.e., electrical permittivity (ε) and magnetic permeability (μ), is quite challenging. Usually, two techniques are used for this purpose, namely, the Nicolson‐Ross‐Weir technique and the dispersive models technique (Lorentz and Drude). However, these techniques fail to produce accurate results when the operating frequency is near the cell resonance frequency. In this article, an improved transition layer‐based homogenization procedure is proposed where the metamaterial cell is homogenized as a Drude–Lorentz multilayer slab. This assumption considerably improves the scattering parameters approach, as demonstrated for a metamaterial slab with a thickness of three Omega cells. In addition, the proposed technique is more suitable for implementation in finite difference time domain (FDTD) methods. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1490–1494, 2016
A Comparison of Online Learning Challenges Between Young Learners and Adult Learners in ESL Classes During the COVID-19 Pandemic: A Critical Review

This critical review aims to make a comparison of online learning challenges between young learners and adult learners in ESL classes during the COVID-19 pandemic. The pandemic has forced the closure of schools and institutions and the shift from face to face classes to online learning which forced the learners to adapt with the transformation. The challenges being faced by the young and adult learners were categorized into three themes, namely learning styles, psychological effect and low academic performance. A total of 40 articles were screened from the years 2020 and 2021. Out of those articles, 29 articles were recognized for the adult learners’ challenges and 11 articles for the young learners’ challenges. The findings suggested there were differences of challenges between the young and adult learners. It is important to recognize the challenges faced by these two levels of learners so that these challenges can be addressed accordingly in the future.
Multi-level analysis of pulsed detonation engines

The present study explores some issues concerning the operational performance of pulsed detonation engines. Zero-, one-, and two-dimensional transient models are employed in a synergistic manner to elucidate the various characteristics that can be expected from each level of analysis. The zero-dimensional model provides rapid parametric trends that help to identify the global characteristics of pulsed detonation engines. The one-dimensional model adds key wave propagation issues that are omitted in the zero-dimensional model and helps to assess its limitations. Finally, the two-dimensional model allows estimates of the first-order multidimensional effects and provides an initial multidimensional end correction for the one-dimensional model. The zero-dimensional results indicate that the pulsed detonation engine is competitive with a rocket engine when exhausting to vacuum conditions. At finite back pressures, the pulsed detonation engine outperforms the rocket if the combustion pressure rise from the detonation is added to the chamber pressure in the rocket. If the two peak pressures are the same, the rocket performance is higher. Two-dimensional corrections added to the one-dimensional model appear to result in a modest improvement in predicted specific impulse over the constant pressure boundary condition.
Finite-time disturbance observer based non-singular terminal sliding-mode control for pulse width modulation based DC–DC buck converters with mismatched load disturbances

This study investigates a finite-time disturbance observer (FTDO) based non-singular terminal sliding-mode control (NTSMC) approach for pulse width modulation based DC-DC buck converters subject to matched/mismatched resistance load disturbances. Considering the mismatched resistance load disturbance which does not act in the same channel as the control input, a novel non-singular terminal sliding-mode manifold incorporating with a disturbance estimation technique is designed. A FTDO-based NTSMC method is introduced for DC-DC buck converter systems. A rigorous finite-time stability analysis is also presented. As compared with the nominal NTSMC and existed SMC+ extended stated observer (ESO) method, the proposed method obtains a better disturbance rejection ability no matter the disturbances satisfy the so-called matching condition or not. Simulation and experimental comparison results are implemented to verify the effectiveness of the proposed control method.
İşbirlikçi filtreleme için yeni tahminleme yöntemleri

Companies, in particular e-commerce companies, aims to increase customer satisfaction, hence in turn increase their profits, using recommender systems. Recommender Systems are widely used nowadays and they provide strategic advantages to the companies that use them. These systems consist of different stages. In the first stage, the similarities between the active user and other users are computed using the user-product ratings matrix. Then, the neighbors of the active user are found from these similarities. In prediction calculation stage, the similarities computed at the first stage are used to generate the weight vector of the closer neighbors. Neighbors affect the prediction value by the corresponding value of the weight vector. In this study, we developed two new methods for the prediction calculation stage which is the last stage of collaborative filtering. The performance of these methods are measured with evaluation metrics used in the literature and compared with other studies in this field.
Toward fully printed Organic Photovoltaics: Processing and Stability

presence of a brittle and expensive ITO electrode is a limiting factor towards low cost OPV modules. Moreover, ITO layers on PET or PEN substrates are typically characterized by relatively high sheet resistances and the presence of large amounts of spikes that lead to efficiency losses. We have developed an alternative for the ITO anode, based on highly conductive PEDOT:PSS in combination with current collecting grids. Moreover, initial experiments indicate that the stability of ITO-free devices is higher than the stability of standard devices based on ITO. This work will ultimately contribute toward fully printed devices, which will provide low-cost manufacturing and improved stability of organic photovoltaics.
Prediction of Nickel Removal using Diffusion Model in Flat Sheet Supported Liquid Membrane

Supported liquid membrane (SLM) is one of the potential extraction methods for the treatment of wastewater containing various toxic heavy metal ions. Advantageously, this process offers simultaneous removal and recovery, as well as low energy consumption and operational cost. In this study, the prediction of nickel removal was investigated using a diffusion model developed through MATLAB.
Interruption performance design of variable freedom mechanism triggered by electro-mechanical-magnetic coupling

Coupling mechanism plays an important role in transmitting, motivating and actuating mechanical functions. However, it is difficult to obtain the transient dynamics performance of mechanism with variable degree of freedom precisely. Therefore, an interruption performance design method of variable freedom mechanism triggered by electro-magneto-thermo coupling is put forward. The Euler-Lagrange partial differential equations of variable freedom mechanism are built using generalized coordinates. Degree of freedom reduction rules are proposed to merge transformation or rotation constraints and obtain the total degrees of freedom of variable freedom mechanism at each transient status. Bivariate interpolating is employed to determine the electro-mechanical-magnetic coupled Lorentz force. Dynamics performance is simulated by iteration of linear algebraic equations using implicit predictor-corrector integration method. The design parameters such as stiffness and pre-tightening force of trigger spring, permissible dimension deviations and hole-shaft fit tolerance are determined and improved using the sensitivity analysis of simulation results. The pneumatic mechanical endurance and thermal infrared temperature rise experiments are accomplished to determine the infrared radiation energy distribution and transient working status of components. It gives an auxiliary thermo-visual approach for transient performance design of coupling mechanism.
Implementation of M-Flex Based Moodle in Pancasila Course: An Initial Evaluation on Student’s View

Abstract M-Flex is the approach used by utilizing various interesting and quality online learning maneuvers. Moodle-based M-Flex learning specifically in Pancasila learning is the focus of this research. The research aimed to see students' initial responses to Moodle-based M-Flex and monitor any benefits and security felt by users. The approach used is qualitative, with interviews as research instruments. The research respondents were 9 students. Analysis procedures used descriptive qualitative methods. In conclusion, the application of M-Flex based on Moodle still faces several challenges related to students' internet connections, the lack of training in using Moodle for students in Pancasila classes, and the assessment design which is still less varied. M-Flex based on Moodle, on the other hand, shows an advantage because it is supported by Moodle features that continue to develop. AbstrakM-Flex adalah pendekatan yang digunakan dengan memanfaatkan berbagai manuver pembelajaran dalam jaringan yang menarik dan berkualitas. Pembelajaran M-Flex berbasis Moodle khusus dalam pembelajaran Pancasila dijadikan fokus dalam penelitian. Tujuan penelitian untuk melihat respons awal mahasiswa terhadap M-Flex berbasis Moodle dan memantau setiap manfaat serta keamanan yang dirasakan oleh penggunanya. Pendekatan yang digunakan adalah kualitatif dengan wawancara sebagai instrumen penelitian. Responden penelitian sebanyak 9 mahasiswa. Prosedur analisis menggunakan metode deskriptif kualitatif. Kesimpulannya penerapan M-Flex berbasis moodle masih menghadapi beberapa tantangan terkait koneksi internet mahasiswa, kurangnya pelatihan penggunaan moodle bagi mahasiswa dalam kelas Pancasila dan rancangan asesmen yang masih kurang variatif. M-Flex berbasis Moodle di sisi lain memperlihatkan keuntungan karena ditunjang fitur moodle yang terus berkembang.
Highly-selective, closely-spaced, dual-band FSS with second-order characteristic

In this study, a closely-spaced, dual-band, band-pass frequency selective surface (FSS) is presented by cascading a two-layer periodic array. The proposed FSS provides two compact pass-bands separated by two transmission zeros, leading to highly selective response. Each pass-band contains two transmission poles, which results in a broad band performance. In addition, the FSS has wide out-of-band rejection due to that the other two transmission zeros occur at upper side of the higher pass-band. The simulation is implemented using full wave electromagnetic wave simulator CST Microwave Studio. The proposed FSS structure is fabricated and measured. Both measured and simulated results show that the operating frequencies of the two pass-bands are, respectively, centred at 9.25 and 11.3 GHz, which are very close to each other. Furthermore, the FSS has the merits of polarisation insensitivity and incident angle stability.
COVID-19 health literacy, coping strategies and perception of COVID-19 containment measures among community members in a southwestern state in Nigeria.

Introduction This study aimed to describe COVID-19 health literacy, coping strategies and perception of COVID-19 containment measures among community members in a Southwestern state in Nigeria. Methods A descriptive cross-sectional design was used to enroll 691 respondents from households in Akure, Ondo state using a multi-stage sampling technique. Data were collected using an interviewer-administered questionnaire between 1st and 9th October, 2020. Bivariate Chi-square tests were conducted on respondents' COVID-19 health literacy while multivariate logistic analysis was performed on significant variables. Statistical significance levels were set at p<0.05. Results Respondents' mean age was 29.93±10.66 years, 352 (50.9%) were males. Also, 292 (49.7%) had high levels of trust in the World Health Organization regarding COVID-19 information, and 31 (33.3%) in the first wealth quintile had good health literacy (χ2=10.459, p=0.033). Respondents below 20 years were twice more likely to have good COVID-19 health literacy (OR=2.304, 95%CI=1.316-4.034, p=0.004). Also, respondents aged 21-29 years were three times more likely to have good COVID-19 health literacy (OR=2.587, 95%CI=1.559-4.293, p≤0.001). Conclusions Available media platforms should be actively engaged by the national government to ensure that community members especially the rich are equipped with good health literacy.
Temporal variation of patch connectivity determines biodiversity recovery from recurrent disturbances

Understanding the capacity of ecological systems to withstand and recover from disturbances is a major challenge for ecological research in the context of environmental change. Disturbances have multi-scale effects: they can cause species extinctions locally and alter connectivity between habitat patches at the metacommunity level. Yet, our understanding of how disturbances influence landscape connectivity remains limited. To fill this gap, we develop a novel connectivity index that integrates the temporal variation of patch connectivity induced by disturbances, which can be applied to any spatially-structured habitat. We then combine this index with a metacommunity model to specifically investigate biodiversity recovery from drying events in river network metacommunities. We demonstrate that patch connectivity explains variations of species richness between groups of organisms with contrasting dispersal modes and captures the effect of drying intensity (i.e., fraction of patches that dry-up) and drying location on community recovery. As a general rule, loss of patch connectivity decreases community recovery, regardless of patch location in the river network, dispersal mode, or drying intensity. Local communities of flying organisms maintained higher patch connectivity in drying river networks compared to organisms with strictly aquatic dispersal, which explained the higher recovery capacity of this group from drying events. The general relationship between patch connectivity and community recovery we found can be applied to any spatial network subject to temporal variation of connectivity, thus providing a powerful tool for biodiversity management in dynamic landscapes.