Miracle-dz/UniFAR-FTUs huggingface dataset:
Graphene Foam Decorated With ZnO as a Humidity Sensor

The effect of ZnO nanorods on the humidity-sensing performance of graphene foam (GF) has been studied. The GF is synthesized by atmospheric pressure chemical vapor deposition (APCVD) using xylene as the hydrocarbon source. Hydrothermal rout is utilized for getting ZnO nanorods loaded on the surface of GF. The obtained materials are characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, Furrier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), BET surface area and BJH pore diameter distribution. The results of this study showed that ZnO nanorods are densely and homogeneously loaded over GF Skelton. The peak values of surface areas are estimated to be 2011.1 cm2/g, and 452.3 cm2/g for GF and GF/ZnO respectively. The humidity sensing performance of ZnO/GF composite shows a linear relationship with the RH value from 20% to 95%.
Design of Control System for Smooth Mode-Transfer of Grid-Tied Mode and Islanding Mode in Microgrid

A complete control system of microgrid with hierarchical control structure based on voltage-source control is proposed in this article, in order to realize the smooth mode-transfer of grid-tied mode (GTM) and islanding mode (ILM), and satisfy the individual design requirements of GTM and ILM simultaneously. This system consists of GTM control, ILM control and mode-transfer control, and high similarity of GTM and ILM control is the most important feature. ILM control adopts an improved parallel-operation droop control, to realize accurate power sharing and eliminate the steady-state voltage bias; GTM control adopts an improved grid-tied droop control, to realize accurate power-flow control and restrain the harmonic current injected to grid. These two methods adopt similar control equations to generate their respective reference voltages (Vref), and uses the same output-voltage control to track Vref. Moreover, the mode-transfer control adopts a grid-tracking control loop to synchronize the ac bus of microgrid with the grid. Based on this design, GTM and ILM can switch directly and smoothly between each other, because the mode transfer is transformed to the switching of Vref generated by GTM and ILM control. Finally, experiment results are presented, which validate the overall performance of the proposed control system.
Extended Look-Ahead Tracking Controller With Orientation-Error Observer for Vehicle Platooning

This paper presents a novel extended look-ahead concept of an integrated lateral and longitudinal vehicle following controller with an orientation-error observer. The control law is based on input-output feedback to address a local tracking problem. It is known that due to the position control in the look-ahead approach, the follower vehicle may cut corners. To address this problem, a reference-induced extended look-ahead tracking point is introduced such that the cutting-corner is compensated. Moreover, the stability of the internal dynamics is analyzed. To address the situation where the orientation tracking error is not measurable or corrupted by noise, an orientation-error observer, constructed from the position tracking error, is designed. The performance of the extended look-ahead controller and the orientation-error observer is investigated by means of a simulation study, and validated with experiments on a mobile robot platform.
Design of a Miniature Underwater Angle-of-Attack Sensor and Its Application to a Self-Propelled Robotic Fish

This article proposes a miniature underwater angle-of-attack (AoA) sensor appropriate to self-propelled fin-actuated underwater robots, featuring real-time measurement of AoA relative to the incoming flow. Specifically, the developed sensor adopts a vane-rotating structure with a high-performance Hall chip that is responsible for detection of the angular deviation. Meanwhile, the Hall-effect-based acquisition scheme endows the device with several features, including low rotational damping, to satisfy underwater usage requirements. Another contribution is that an AoA model is derived to allow the real-time acquisition of AoA at the trailing edge of the caudal fin assumed in a quiescent flow. Based on this model, the AoA profile is obtained as theoretical reference with only the control laws required. Finally, the performance of the numerical model and the developed sensor are investigated through aquatic experiments assisted by a global visual measurement system. The experimental results demonstrate that the acquired AoA possesses over 0.97 Parson correlation coefficient with the theoretical data, verifying the effectiveness of the proposed mechatronic design. The developed AoA sensor and its application to robotic fish could provide potential assistance for the flow control and hydrodynamic optimization of fin-actuated underwater robots.
Multiple-model switching control for vibration suppression of planar membrane structures

Membrane space structures have received widespread attention because of their small packaging volume and low mass. However, because membranes are very flexible and lightly damped, vibration suppression in membrane structures is very difficult. The objective of this study was to solve this problem. The first part of this article describes the influence of wrinkling in a membrane structure on the structure’s vibration characteristics. On this basis, the vibration deformations of a wrinkled square membrane structure were derived from the dynamic equations, and the correctness of this vibration model was verified by numerical simulation and experiment. A multi-model system is proposed to simulate the dynamic response of a membrane structure under different boundary conditions. In combination with the drive system, a multi-model switching control method based on adaptive and proportional–integral–derivative control is proposed. Under the initial disturbance, when the vibration amplitude dropped below 0.01 mm, the vibration duration was reduced to 2.96 s, compared with the duration of 12.37 s without control. The duration was shortened by approximately 39.7%, compared with the duration of 4.91 s achieved by the traditional proportional–integral–derivative control method, and by approximately 15.9% compared with the 3.52 s achieved by the out-plane control method. When there were multiple disturbances and the proposed method was used, the boundary displacement loadings did not increase when a certain value was exceeded. This prevented the breaking of the membrane by overstretching and provides a theoretical foundation for setting the initial pre-stress values.
Speed Sensorless Control for Permanent Magnet Synchronous Motors Based on Finite Position Set

This article presents a novel method for the sensorless control of interior permanent-magnet synchronous motors. An iterative search strategy based on dichotomy is proposed to provide a finite number of rotor position angles with good accuracy. These position angles are used to calculate the back electromotive force (EMF) in d-axis. The optimal rotor position angle is the one that yields a back EMF minimizing the defined cost function. With the increase of the iterations, the accuracy of rotor position angle increases geometrically. To effectively extract the back EMF signal under the low-speed condition, the high-frequency signal injection method is used to realize the low-speed operation of the motor. A hybrid control strategy is adopted to achieve the smooth switching from the low-speed to high-speed. The performance of the proposed method has been validated experimentally and compared with that of the conventional phase locked loop under different conditions.
Summary of Findings from The New Zealand Army Recruit Nutrition and Health Project - 2009

Nutrition and physical training play an important role in the physical and cognitive development of military personnel. This report summarises the extensive findings of each phase of the New Zealand Army Recruit Nutrition and Health Project and provides recommendations to help enhance physical and cognitive performance, both during training and throughout a soldier’s career. Defence Technology Agency Auckland, New Zealand 1 CAPT Nicola Martin is currently the New Zealand Army Dietitian.
Multi-Objective Demand Side Management at Distribution Network Level in Support of Transmission Network Operation

This paper proposes a methodology for advanced demand side management (DSM) in the distribution network (DN), catering at the same time for the requirements of the network operator, transmission or distribution, the available flexibility of the demand side, and the preservation of network performance. The basic premise of the study is that the distribution network operator is providing flexibility to the transmission system operator through load shaping. Different, one or more, indicators can be chosen to assess preservation of network performance. In this paper, for illustrative purposes of the methodology, the steady state voltage stability index, namely the load margin, is chosen as the network performance indicator. This is evaluated before and after a DSM action, in order to analyse the possible effect of DSM on network loadability. Load at each DN bus is represented using a realistic composite load model comprising controllable and uncontrollable loads. The DSM is initially performed based on optimal power flow calculation to ensure that the distribution system load profile at the grid supply point follows the required (pre-specified) load profile during a 24 hour period. Following this, a particle swarm optimisation is used to modify DSM program in those time steps of the planning horizon where load margin is reduced. The methodology is illustrated on a number of case studies using modified IEEE 33 bus distribution network model. The results illustrate the extent to which the available flexibility of demand can be used in support of transmission network operation when the preservation of network performance and appropriate load modeling are considered.
Dimensions Selection Criteria of Stair shaped Slot for Obtaining the Wideband Response of CPDRA

The analysis of a circularly polarised (CP) dielectric resonator antenna (DRA) with the aperture coupled feeding technique is presented in this paper. Until now, the random techniques have been developed for obtaining the CP response in DRA. It is glaringly required to develop a fixed mathematical criterion for the selection of dimensions of the antenna structure. The criterion for selection of the stair-shaped slot dimensions, which is utilised for obtaining the CP response, is defined in this paper. The ranges of slot length ratios are investigated so that a wide CP bandwidth can be obtained. The antenna offers the 10-dB impedance of 58.62% (4.1 GHz - 7.5 GHz) and 3-dB axial ratio bandwidth of 40.86 per cent (4.26GHz - 6.385 GHz).
Separated Phase–Current Controls Using Inverter-Based DGs to Mitigate Effects of Fault Current Contribution from Synchronous DGs on Recloser–Fuse

Synchronous distributed generators (SDGs) significantly affect recloser–fuse coordination due to the high fault current contribution. This paper proposes a separated phase–current control using inverter-based distributed generators (IBDGs) to remove the effects of fault current contributions from SDGs during unsymmetrical faults. The three-phase current produced by IBDGs is independently controlled. While the total fault current is reduced by adjusting the current phase angle in the faulty phase, the energy in the DC-link capacitor (Cdc) is delivered to the grid in order to avoid the rise of DC-link voltage (Vdc) by means of injection of the active current into the nonfaulty phase. To maintain the proper grid voltage, the voltage regulation feature is installed in the IBDGs. Moreover, current estimations programmed within the IBDGs are introduced to avoid the performance degradation of separated phase–current controls caused by phasor measurement units (PMUs). The dynamic performance of the separated phase–current controls using IBDGs was evaluated using an IEEE 34-node radial test feeder. According to the simulation results, the IBDGs could eliminate the effects of fault current contributions from the SDG without interruption since the disconnections caused by excessive Vdc were prevented. They could also regulate the grid voltage in the nonfaulty phase.
Integrated Predictor Based on Decomposition Mechanism for PM2.5 Long-Term Prediction

It is crucial to predict PM2.5 concentration for early warning regarding and the control of air pollution. However, accurate PM2.5 prediction has been challenging, especially in long-term prediction. PM2.5 monitoring data comprise a complex time series that contains multiple components with different characteristics; therefore, it is difficult to obtain an accurate prediction by a single model. In this study, an integrated predictor is proposed, in which the original data are decomposed into three components, that is, trend, period, and residual components, and then different sub-predictors including autoregressive integrated moving average (ARIMA) and two gated recurrent units are used to separately predict the different components. Finally, all the predictions from the sub-predictors are combined in fusion node to obtain the final prediction for the original data. The results of predicting the PM2.5 time series for Beijing, China showed that the proposed predictor can effectively improve prediction accuracy for long-term prediction.
Analysis of existing gender differences in the effect of using the Virtual Campus platform of the Politehnica University of Timisoara

Admitting the increasing interest for education delivered by the means of technology is relevant if we consider all the aspects, including features related to gender. Several studies point out that women and men differ in their way of interacting with technology, ICT being traditionally associated with men [1]. In the context of blended learning settings, there are several existing gender differences, which means a statistical analysis focused on differences between men and women users of the Virtual Campus platform is needed. The main objective of this study is to provide evidence of significant gender differences in the effect of using certain platform tools by both genders. A subsequent objective is to test if the efficiency of both manners of working with e-learning tools eventually converge around similar results (in case the results point to scarce differences). The research was conducted by looking at the final number of students following the Distance Learning program run by the eLearning Center at UPT, during the first semester of the academic year 2017-2018. Distance learning students enrolled at Politehnica University Timisoara are mostly digital natives, consumers of technology in order to support the teaching and learning processes. The aim of this paper is to analyze the gender differences in using the platform, based on the students’ online activity statistics from Moodle and all the resulting data.
Disturbance-Observer-Based Sensorless Control of PMSM Using Integral State Feedback Controller

The objective of this article is to design robust speed control of a permanent magnet synchronous motor (PMSM). The mathematical model of the PMSM is highly nonlinear with uncertainties and disturbances. The most obvious method is to estimate these disturbances and design a robust controller to attenuate the effect of disturbances from the output. In this article, the load torque, which typically occurs as disturbance in the servo system, is estimated using a disturbance observer (DO). A nonlinear model of the PMSM is linearized using the Jacobian linearization around an operating point, and a state feedback controller with an integral term is designed at this operating point. Novelty of the proposed method lies in the way the DO is used to update this operating point, which is similar to the gain scheduling approach. To extend this method for a sensorless operation, a sliding-mode observer is used with the DO in cascade. The proposed scheme is validated using simulations on MATLAB/Simulink and an experimental setup using TMS320F28027. The results show improved performance as compared to traditional methods over a wide range of speed.
Inter‐laminar fault analysis of magnetic cores with grain‐oriented electrical steels under harmonic distortion magnetisations

Inter-laminar faults (ILFs) have major impacts on the overall performance of the electrical machines and power transformers, among which extra power loss and hence lower efficiency could be highlighted. This paper presents an in depth analysis on energy loss and energy loss components of stacks of Grain-Oriented (GO) electrical steels subjected to different kinds of ILFs, under sinusoidal and non-sinusoidal inductions. Practical methods are developed to monitor quality of the magnetic cores, based on the measured static and dynamic hysteresis loops (SHL and DHL). The experimental results showed that, ILFs have a significant impact on the dynamic performance and dynamic energy loss of the cores, while their impact on the hysteresis loss is negligible. Furthermore, they become more destructive under non-sinusoidal inductions, and hence condition monitoring of the magnetic cores is more important for these applications.
A 10-kS/s 625-Hz-Bandwidth 65-dB SNDR Second-Order Noise-Shaping SAR ADC for Biomedical Sensor Applications

This paper introduces a low-power noise-shaping SAR ADC which is suitable for biomedical sensor applications. In this ADC, a low power consumption and area-efficient integrator is proposed, which is comprised of several switches, replica capacitors and a dynamic amplifier (DA). With a mode control logic circuit, the comparator in the ADC is reused as an amplifier for three times (three amplification phases) in a single conversion period to save area and power consumption. With the introduction of the first amplification phase, the additional capacitance can be greatly reduced without increasing overall kT/C noise. The second and third amplification phases decouple NTF zeros from the attenuation factor, allowing further area reduction. The comparator in amplification mode is designed more robust than prior arts. Fabricated in $0.18\mu \text{m}$ CMOS process, the prototype ADC has a 7-bit DAC and occupies a core area of 0.12mm2. Operating at 10kS/s, it consumes 90nW from a 1-V supply. At an OSR of 8, the SAR ADC achieves 65dB SNDR resulting in a FoMs of 163.5dB, and a FoMw of 50fJ/conv. -step.
Comparison of Health of Height-Weight Matched Young-Adult Female Athletes of Hilly and Plane Regions in Selected Anthropometric Measurements

Height and weight are the major two determinants for various anthropometric properties at any age in life. People of different racial origins and geographical locations have specific anthropometric features. Purpose of this study was to compare health status of height-weight matched young-adult females of hill and plane regions through selected anthropometric measurements. Sixty (N=60) 18– 25 years female, thirty from each of the hill and plane localities were the subjects. The height range was 157.5 – 162.5 cm and weight was 52.5 – 55.5 kg. Seven skin-folds, six body circumferences and three body composition measures, namely – body mass index (BMI), waist-to-hip ratio (WHR) and body fat percentage (%BF), derived from respective anthropometric measurements, all were the variables of the study. Out of seven skin-folds, plane subjects were significantly higher (P>0.05) at only biceps site and hilly subjects at sub-scapula, suprailiac, abdomen and thigh but no difference existed at triceps and calf. Among the seven body circumferences, hilly girls were superior at upper limb, lower limb and waist circumferences; however, at thigh, calf, abdomen and hip sites there was no any significant difference between the groups. Among the three body composition measures, only %BF and WHR was higher in hilly subjects. But LBM and BMI did not differ in both groups.
Visual SLAM With BoPLW Pairs Using Egocentric Stereo Camera for Wearable-Assisted Substation Inspection

The combination of wearable sensors and Augmented Reality (AR) technology has shown promising prospects in assisting substation inspection, especiallywhen the tasks are infrequent and unfamiliar to human operators. In this paper, a wearable-assisted system (WAS) is proposed for task-specific global navigation and position-aware workflow guidance using a head-mounted stereo camera. The key of our proposal is an extended stereo visual SLAM approach is proposed with Bags of Point and Line Word (BoPLW) pairs, which ensuresmore accurate and robust dynamic egolocalization performance against several challenges that are typical in substations, such as similar facilities, low-textured scenes and lighting changes. In addition, the paper proposes to learn a global Metric-Topological Abstract map (MTA-map) for supporting map-based re-localization and navigation guidance. A prototype of WAS is developed in which augmentations of guidance are delivered to users via an optical see-through display. The system is evaluated in field experiments designed as an substation inspection scenario and other similar industrial inspection applications. The results validate the practicability and effectiveness of the system. Our code is available at https://github.com/robotseu/ORB_Line_SLAM.
A Chance-Constrained Multistage Planning Method for Active Distribution Networks

This paper introduces a multistage planning method for active distribution networks (ADNs) considering multiple alternatives. The uncertainties of load, wind and solar generation are taken into account and a chance constrained programming (CCP) model is developed to handle these uncertainties in the planning procedure. A method based on a k-means clustering technique is employed for the modelling of renewable generation and load demand. The proposed solution methodology, which is based on a genetic algorithm, considers multiple planning alternatives, such as the reinforcement of substations and distribution lines, the addition of new lines, and the placement of capacitors and it aims at minimizing the net present value of the total operation cost plus the total investment cost of the reinforcement and expansion plan. The active network management is incorporated into planning method in order to exploit the control capabilities of the output power of the distributed generation units. To validate its effectiveness and performance, the proposed method is applied to a 24-bus distribution system.
A New Family of 1-φ Five-Level Transformerless Inverters for Solar PV Applications

This article presents a family of 1-φ transformerless switched-capacitor based five-level inverter (TSC5LI) topologies for photovoltaic (PV) applications. The proposed family comprises four inverter topologies: H8, H8-UPF, H10, and H10-UPF capable of mitigating the leakage current by having continuous grid frequency voltage at PV parasitic capacitor in spite of considering switch terminal capacitances. A distinctive attribute of the TSC5LI is that 100% dc-bus utilization, symmetrical operation, and constant total common-mode voltage (TCMV) are achieved together. H8 variant of the proposed inverter family is studied extensively. The control strategy used is a simple level-shifted sine-triangle pulsewidth modulation followed by the synthesis of the gate pulses utilizing logical functions. Switching function based TCMV analysis, switched capacitor design, and loss analysis are presented. Simulation and experimental results of H8 variant are presented to validate the theoretical claims. Proposed topology is also compared with the existing five-level transformerless inverters to prove its various advantages.