Miracle-dz/UniFAR-FTUs huggingface dataset:
Non-Isolated High-Gain Triple Port DC–DC Buck-Boost Converter With Positive Output Voltage for Photovoltaic Applications

The solar PV based power generation systems are growing faster due to the depletion of fossil fuels and environmental concerns. Combining PV panels and energy buffers such as battery through multi-port converter is one of the viable solutions to deal with the intermittency of PV power. The goal of this paper is to design and analyze the proposed triple port DC-DC buck-boost converter for high step-up/step-down applications. It has two unidirectional ports (port-1 and port-3) and one bi-directional port (port-2) for harnessing photovoltaic energy and charging the battery. At port-1, the combined structure of buck and buck-boost converter is used with a particular arrangement of switches and inductors. The step-up/step-down voltage conversion ratio is higher than the conventional buck-boost converter, and the polarity of the output voltage is maintained positive. The battery is added at the bi-directional port, for the storage of energy through the bi-directional boost converter. The switches operate synchronously for most of the modes making the control strategy simple. The characteristics and modes of operation along with a switching strategy, are elaborated. Experimental results are presented which validate the agreement with the developed theoretical expectation.
Wireless Power Transformation for Data Centers and Medium Voltage Applications

Wireless power transfer (WPT) techniques have been widely explored for various applications including for electric vehicle (EV) and mobile phone charging. Less attention has been paid to the use of WPT for commercial or industrial applications and for power distribution. An isolated wireless power link can enable a touch safe interface without electrically energized contacts eliminating any arc flash or electrocution hazard. This concept can for example enable safe medium voltage distribution inside data centers eliminating low voltage distribution with its large bus bars and cables and bring voltages larger than 1kV directly to the rack. A design methodology is developed for a low loss, high voltage-transfer-ratio wireless power link and a high efficiency medium voltage power converter. The proposed design methodology is evaluated using a 10kW design example and verified by finite element analysis (FEA) and experimental tests. The WPT transformer is developed with a planar magnetics structure. A U-shape ferrite configuration is proposed to improve mutual coupling by providing a low magnetic reluctance coupling path for the magnetic flux. A high efficiency power converter is developed to maintain the output voltage (48V) with a 1kV input over a wide load range. The power transfer efficiency and loss distribution are analyzed.
MIXED-SPECIES FLOCKING AND FORAGING BEHAVIOR OF FOUR NEOTROPICAL WARBLERS IN PANAMANIAN SHADE COFFEE FIELDS AND FORESTS

Abstract We quantified foraging rates and foraging visibility metrics for four Neotropical warblers—Slate-throated Redstart (Myoborus miniatus), Golden-crowned Warbler (Basileuterus culicivorus), Wilson's Warbler (Wilsonia pusilla), and Black-and-White Warbler (Mniotilta varia)—under flocking and solitary conditions in western Panama to test hypotheses regarding the relative influences of predation pressure and social facilitation on foraging behavior. We also compared foraging behavior in primary forests and in traditionally managed shade coffee fields for two species (Slate-throated Redstart and Wilson's Warbler) to estimate spatial variation in foraging behavior and compare it to variation due to social situation (flocking or solitary). We then assessed the contribution of spatial variation in flocking propensity to the total spatial variation in foraging rates within species. We observed very little overall within-species variability in foraging behavior between social situations or study locations. Only Slate-throated Redstart's behavior was consistent with the hypothesis that flock membership reduces predation pressure and therefore reduces the amount of foraging time spent being vigilant against predators, allowing birds to forage more quickly and find more prey items per minute. No species' behavior supported the hypothesis that flocking birds forage more efficiently than solitary birds by obtaining useful information from flock mates about the location or suitability of foraging resources or techniques. The effort required to find prey items did not vary between study locations (forest and coffee field plots) for Wilson's Warbler. Because flocking also had no effect on foraging behavior of Wilson's Warbler, a reduction in flocking propensity in coffee habitat, relative to forest, did not cause further foraging behavior differences between study locations. Spatial variation in Slate-throated Redstart's foraging behavior independent of a flocking effect was minor; but flocking affected foraging rates, and flocking propensity was lower in coffee fields than in forest, so that location and flocking effects combined to widen foraging rate differences between locations. Thus, variations in flocking behavior and foraging behavior interacted differently for those two species.
STEM Educator challenges and professional development needs: the educators’ views

This work researched the educators’ views regarding the challenges, the difficulties and the professional development needs of STEM educators. Drawing on an online survey, based on specially designed close-ended and open-ended questions, we analyzed the educators’ views in order to understand critical factors and to provide more insight regarding the successful preparation of STEM educators. In this study, 59 educators, who have been involved in the implementation of STEM educational programs in Greece, were participated. Results showed that educators face several challenges and difficulties, while the misunderstandings of parents about STEM education also affect educators’ work. In addition, although professional development on different topics was considered necessary depending on educators’ needs and academic background, technical training was a common need for the participants. Our findings suggest that redesign of the national curriculum and the implementation of targeted training programs based on specific needs are needed to better support the role of STEM educator.
Expanding the level of engineer knowledge for software modeling within corporate education by active and collaborative learning

Educational training for employee development inside an IT company should result in an efficient increase in professional knowledge. The reasons are the significant impact on work productivity and the high dependency on project success, influenced by that knowledge. The bottleneck in communication between engineers, architects, business analysts, and the client is the basis to gain mutual understanding in defining requirements, transposing into specifications, and finally accepting a software. To reach that demand for efficiency, everyone in the chain of software development should be familiar with the mastery of software modeling. In this paper, authors share their experiences and explain how to leverage that knowledge through project-based learning, active and collaborative learning, delivered as face-to-face, self-paced e-learning, and online training courses, under the mentorship of experienced business analysts.
Two-Stage Hybrid Beamforming Design for mmWave Multi-User Massive MIMO Systems

Hybrid beamforming (HBF) with massive multiple-input multiple-output (MIMO) is a promising technology for reaching a compromise between hardware complexity and system performance in 5G millimeter-wave (mmWave) communications systems. In this paper, we investigate the hybrid beamforming design in the downlink multi-user massive MIMO systems. According to information theory, we divide the communication procedure with hybrid beamforming into two different stages. In the analog stage, we propose an alternating optimization scheme to design the analog precoder and combiner, thereby maximizing the capacity of the equivalent baseband channel. Then, in the digital stage, we exploit the baseband block diagonalization method for the design of digital beamformer to eliminate inter-user interference. Finally, simulation results demonstrate that the proposed algorithm can achieve a higher sum-rate than some existing multi-user HBF schemes, while the convergence of the proposed algorithm is relatively fast.
Bioaccumulation of Selected Metals and Histopathological Alterations in Tissues of Oreochromis niloticus and Lates niloticus from Lake Nasser, Egypt

The concentration of some heavy metals (Fe, Zn, Cu, Pb, Cd and Co) in water and liver, gills, intestine, testis, heart and muscle of O. niloticus and L. niloticus obtained from four khors (El-Ramla, Kalabsha, Korosko and Toushka) of Lake Nasser, Egypt during 2006 was investigated (atomic absorption spectrophotometry) with emphasis on the histological alterations in these organs. Metal concentrations in the water of khors (mg/l) followed an abundance of: Fe>Zn>Pb>Cu>Cd>Co. The highest values of metals were reported in khor Toushka. It was found that the metals were accumulated in different tissues of both fish by various levels, where, the non-edible parts accumulated more metals than the edible muscles. Zn, Cu, Pb and Cd concentrations in the fish muscles were blow the maximum permissible limit, however, Fe in the muscles exceeded the permissible limit. Several histopathological alterations, including vacuolar degeneration with focal areas of necrosis in liver, proliferation in the epithelium of gill filaments and fusion of secondary lamellae, severe degenerative and necrotic changes in the intestinal mucosa and seminiferous tubules, degeneration and atrophy in cardiac muscle fibers and degeneration in muscle bundles were observed in the studied tissues of both fish as a result of the accumulated metals.
The Algorithm of UAV Automatic Landing System Using Computer Vision

This paper discusses the algorithms of vision systems for automatic UAV (Unmanned Aerial Vehicle) landing. The basic algorithms for finding helipad and adapting the UAV control system to an autonomous UAV landing are presented. The authors consider algorithms to solve navigation problems, building block diagrams of automatic UAV control. Also, the developed algorithms make it possible to implement an automatic landing system for UAVs using technical vision systems, using various camera parameters, algorithms allowing research, as part of the autonomous navigation of unmanned aerial vehicles. The article discusses the developed algorithm that allows you to highlight certain characteristic points for visual navigation. Also, a search system for characteristic points has been developed that allows automatic UAV landing. These algorithms may be useful for the autonomous landing UAV systems. Algorithms can also be used to track a trajectory of the UAV system.
Analysis of High Frequency AC Link Isolated Three Port Resonant Converter for UAV Applications

A high frequency AC link isolated three port semi-bridgeless resonant converter is analyzed for unmanned aerial vehicle (UAV) applications in this study. The proposed topology is established by replacing rectifier lover diodes with synchronous switches. A phase shifted pulse width modulation (PS-PWM) technique adjusts bi-directional power flow between ports. Proposed control technique provides high efficiency by reducing switching losses with zero voltage switching (ZVS) and zero current switching (ZCS) in a wide power range regulation. Compared to integrated PWM converters in a bi-directional mode, the proposed topology reduces the number of converter stages and allows centralized control at high operating frequency. Theoretical and experimental results demonstrate the feasibility and effectiveness of the proposed converter at a full power of 500 W in laboratory conditions.
Multi-Attention Network for Stereo Matching

In recent years, convolutional neural network (CNN) algorithms promote the development of stereo matching and make great progress, but some mismatches still occur in textureless, occluded and reflective regions. In feature extraction and cost aggregation, CNNs will greatly improve the accuracy of stereo matching by utilizing global context information and high-quality feature representations. In this paper, we design a novel end-to-end stereo matching algorithm named Multi-Attention Network (MAN). To obtain the global context information in detail at the pixel-level, we propose a Multi-Scale Attention Module (MSAM), combining a spatial pyramid module with an attention mechanism, when we extract the image features. In addition, we introduce a feature refinement module (FRM) and a 3D attention aggregation module (3D AAM) during cost aggregation so that the network can extract informative features with high representational ability and high-quality channel attention vectors. Finally, we obtain the final disparity through bilinear interpolation and disparity regression. We evaluate our method on the Scene Flow, KITTI 2012 and KITTI 2015 stereo datasets. The experimental results show that our method achieves state-of-the-art performance and that every component of our network is effective.
Smart Technology to Improve Cultural and Gender Diversity in Engineering Education

Women, people from non-academic families, single parents and those with a migration background represent an underutilized pool of potential future professionals in engineering disciplines. Many potential candidates from these underrepresented groups may not even consider a career in engineering due to language, bureaucratic and financial hurdles as well as a lack of identification with traditional role models. The requirements engineering, prototypical development and initial testing of a smart technology chat bot to recruit engineering students from underrepresented groups is presented.
Cascaded Packed U-Cell STATCOM With Low Capacitance And Its Third Harmonic Control

This paper proposes a novel STATCOM by cascading packed U-cell (CPUC) and using low capacitance. Compared to cascaded H-bridge, the CPUC-STATCOM can largely reduce switch counts and their related gate driver circuits. Then, skillfully utilizing the principle that the second-order harmonic component of capacitor voltage is in phase with the absolute value of grid voltage in capacitive mode, low capacitance is used in CPUC-STATCOM. It can reduce cost, weight and volume of system compared to usually using large capacitance to limit voltage ripple within 10% of nominal capacitor voltage. However, it has limited compensation capability in inductive mode by using low capacitance. Aiming at overcome the aforementioned drawback, a flexible third harmonic control method is proposed, which can reduce capacitor peak voltage and averaged voltage. Finally, the simulation results verified the performance of the proposed topology and control method.1
Exploiting the Agent's Memory in Asymptotic and Finite-Time Consensus Over Multi-Agent Networks

This article proposes two average consensus algorithms exploiting the memory of agents. The performance of the proposed as well as of several state-of-the-art consensus algorithms is evaluated considering different communication ranges, and evaluating the impact of transmission errors. To compare asymptotic and finite-time average consensus schemes, the <inline-formula><tex-math notation="LaTeX">$\varepsilon$</tex-math></inline-formula>-convergence time is adopted for a fair comparison. A discussion about memory requirements, transmission overhead, <italic>a priori</italic> information on network topology, and robustness to errors is provided.
Data-Aided Sensing Where Communication and Sensing Meet: An Introduction

Since there are a number of Internet-of-Things (IoT) applications that need to collect data sets from a large number of sensors or devices in real-time, sensing and communication need to be integrated for efficient uploading from devices. In this paper, we introduce the notion of data-aided sensing (DAS) where a base station (BS) utilizes a subset of data that is already uploaded and available to select the next device for efficient data collection or sensing. Thus, using DAS, certain tasks in IoT applications, including federated learning, can be completed by uploading from a small number of selected devices. Two different types of DAS are considered: one is centralized DAS and the other is distributed DAS. In centralized DAS, the BS decides the uploading order, while each device can decide when to upload its own local data set among multiple uploading rounds in distributed DAS. In distributed DAS, random access is employed where the access probability of each device is decided according to its local measurement for efficient uploading.
Small-signal Modeling for Adaptive Closed-loop Control in Two-coil Wireless Power System

In this paper, a small-signal modeling for an adaptive closed-loop control in two-coil wireless power transfer (WPT) system is presented and discussed. In the WPT system, the output voltage/power is controlled to maintain constant under changing transmission distances (DIS) and misalignment (MIS) conditions between transmitter coil (Tx) and receiver coil (Rx). The WPT system consists of a non-inverting buck-boost converter, a switching power amplifier (for DC to AC conversion), a Tx coil, a Rx coil, a full-bridge rectifier (for AC to DC conversion) and a micro controller unit. Modeling for the system is analyzed to facilitate and guide the design of the controller. The developed small-signal modeling is evaluated and validated by the system bode plots and voltage reference transient experimental results. Detailed sets of modeling derivation are analyzed and discussed throughout the paper and the system operation and performance are evaluated.
Vocational Education and Training Apprenticeship: Using Teaching and Learning Analytics in a Learning Management System for improved Collaboration, Individual Empowerment and Development of Apprentices

The Vocational Education and Training (VET) curriculum aims to provide students with the necessary skills to make them employable and successful in their specialties. Therefore, an increasing number of VET curricula are employing various resources to equip students with 21st century skills such as critical thinking, creativity, communication, collaboration, and information literacy. In this paper, we explore the key dimensions of active learning for empowering and enriching Collaboration, Individual Empowerment, and Development of the apprentices’ learning processes through Teaching and Learning Analytics (TLA), in a Learning Management System (LMS) for VET apprenticeships. We describe in detail “how TLA can “work” in a VET environment, and we present how we organize the TLA methodology inside the proposed LMS.
From monsoons to mantas: seasonal distribution of Manta alfredi in the Maldives

The Republic of Maldives in the central Indian Ocean is home to large numbers of manta rays, Manta alfredi. They are known to undertake seasonal migrations within the Maldives, but these movements have not been well documented. The aims of this study were to map the seasonal distribution of manta rays within the Maldives, and to provide some indications of the physical and biological oceanographic processes affecting their distribution. The seasonal distribution of mantas was determined from a national survey of fishermen, interviews with experienced divers and personal observations. The data demonstrate that the distribution of mantas is strongly influenced by the seasonally reversing monsoon currents. Mantas occur on the downstream sides of the atolls, and are rare on the upstream sides, switching sides biannually as the monsoon currents change direction. These seasonally alternating currents are driven by monsoon winds which also alternate according to the season, and bring clear oceanic water to the upstream sides of the atolls. As the currents pass over the Maldives ridge, nutrient-rich waters are lifted to the surface, promoting phytoplankton blooms (as demonstrated by the distribution of chlorophyll-a) on the downstream sides of the atolls. This manifestation of the island mass effect supports an abundance of zooplankton, which in turn supports the manta rays.
Microsatellite markers for Sachalin fir (Abies sachalinensis Masters)

We developed eight polymorphic microsatellite markers from the Sachalin fir (Abies sachalinensis Masters). The number of alleles per locus ranged from eight to 31, with an average of 21.4. The observed and expected heterozygosities ranged from 0.656 to 0.937 and from 0.710 to 0.945, respectively. These markers will be available for population genetic studies and parentage analysis.
Defending Blockchain Forking Attack by Delaying MTC Confirmation

In terms of security, blockchain technology faces the potential risks of enormous attacks, among which forking attack is the most common one. Because of the decentralized structure of a blockchain, the trust degree directly relies on the length of the blockchain, which makes the longest chain on the current network the most trusted chain (MTC). The forking attack is the kind of hazard behavior that aims to replace the MTC by launching an alternative chain to gain benefits. Blockchain plays a vital role in multiple applications, such as cryptocurrency, and hence such forking attack leads to huge financial loss if it succeeds. In this paper, we propose a novel MTC confirmation mechanism to defend the forking attack. First, we theoretically analyze the success probability distribution of the forking attack and propose an estimation model of the attack’s expected profit. Then, we propose an arbitration mechanism to enforce branches from a fork to have competition. With the arbitration mechanism, we delay the confirmation of the MTC until the end of the competition. We set up an end threshold as the termination condition of the competition process to help the MTC become the winner. Finally, we define two dynamic difficulty factors and apply them for changing the difficulty of mining to reduce the value of the end threshold, which can improve the performance of the mechanism. The experiments demonstrate our proposed MTC confirmation mechanism can enhance the blockchain security by enforcing the expected profit of an attack to be negative. In the meantime, the mechanism balances well in both effectiveness and efficiency.