Miracle-dz/UniFAR-FTUs huggingface dataset:
Integrated Vivaldi antenna for UWB/diversity applications in vehicular environment

This article presents the design of a three‐port diversity antenna capable of producing three‐directional radiation pattern for vehicular communications. The proposed antenna consists of three uncorrelated Vivaldi antennas that are interconnected and developed on a single printed circuit board. Unlike many other antennas reported for the vehicular environment, the proposed antenna offers ultra‐wideband characteristics with end‐fire radiation pattern leading to high realized antenna gain. The integrated antenna has a footprint of 65 × 40 × 1.6 mm3 and offers 6 GHz impedance bandwidth extending from 5 to 11 GHz. The port‐to‐port isolation is greater than 20 dB within the operating bandwidth. Furthermore, the diversity performance of the proposed three‐port antenna system is evaluated and presented. The calculated envelope correlation coefficient, diversity gain, and mean effective gain are well above the minimum requirement. The prototype antenna is fabricated and the experimental results are presented.
Energy harvesting of beam vibration based on piezoelectric stacks

Piezoelectric stacks demonstrate excellent properties for energy harvesting owing to the high energy conversion efficiency and long lifetime. However, force amplification frames are commonly required to amplify the load applied to piezoelectric stacks. This paper proposes an energy harvester based on piezoelectric stacks without force amplification frames. The piezoelectric stacks are composed of annular piezoelectric sheets separated into several conductive sectors on the surface and mounted on a beam through a threaded sleeve and a nut. Experiments and simulations are carried out to evaluate the output performance of the energy harvester when the beam vibrates in transverse direction. The effects of excitation frequency, sector number, preload level, mounting position and piezoelectric sheet number on the output voltage are evaluated. Results from experiments and simulations show that the energy harvester gets the highest output gain as the excitation frequency reaches the resonant frequency of beam. When the piezoelectric sheets are divided into two insulated semi-circular regions, the best output performance can be obtained under the same loading conditions. Increasing the preload level is also beneficial for achieving high output voltage. However, this effect gets insignificant when the preload reaches to a certain value. The output gain of the energy harvester increases with the number of piezoelectric sheets. The output voltage is higher when the energy harvester is mounted at the beam center than that mounted at the beam ends.
Design and Experimental Evaluation of Immersion and Invariance Observer for Low-Cost Attitude-Heading Reference System

This article presents a new immersion and invariance (I&I) observer for inertial microelectromechanical systems (MEMS) sensors-based, low-cost attitude-heading reference systems (AHRSs). Using the I&I methodology, the observer design problem is formulated as finding a dynamics system, called the observer, and a differentiable manifold in the extended state space of the Euler angles-observer dynamics. The manifold is required to be practically stable with respect to the system trajectories. By imposing this requirement, an observer is derived to robustly estimate the Euler angles. To show the efficacy of the I&I observer and to compare its performance with the extended Kalman filter, rigorous simulations are performed using the raw data of a set of urban vehicular AHRS tests.
BIM adoption and implementation: focusing on SMEs

Purpose To reach its full potential, Building Information Modelling (BIM) should be implemented throughout the supply chain. The purpose of this study is to explore BIM implementation and adoption among Small and Medium Enterprises (SMEs) in the UK Architecture, Engineering and Construction (AEC) sector. The paper addresses two key issues: the slow rate and lack of homogeneity of BIM adoption in the SME sector. Design/methodology/approach The study uses qualitative and quantitative methods to investigate BIM uptake and test for correlations between organisational features and BIM aspects. The sample includes data from SMEs based in the South East of England, which are then analysed using descriptive and inferential statistics. Findings The results show that, although SMEs have some understanding of BIM-related concepts, their familiarity with existing BIM software support systems is particularly low. Limited financial capacity is identified as the primary barrier to BIM adoption while knowledge exchange initiatives are the most useful measure in facilitating further implementation. The variations of SMEs in the adoption and implementation of BIM are mostly affected by company size, professional discipline and offered services. The paper also demonstrates that a one-size-fits-all approach to BIM implementation in the AEC sector has limited potential. Originality/value The heterogeneity of SMEs in the AEC sector has been considered to a very limited extent. This paper considers the nature, characteristics and core business areas of SMEs as factors affecting BIM adoption and implementation.
The Innovation of Glassfiber Reinforced Cement (GRC) Application in Buildings

One example of the innovation in building construction that is expansively used at present is Glassfiber Reinforced Cement (GRC). GRC is a cement product based on material mixed with fiberglass. GRC is one of the developments of concrete. This product easily and efficiently provides solutions to a variety of building designs. Additionally, its various forms can be applied to numerous types and functions of buildings. This research aimed to identify the suitability of GRC for several functions. The methods in this study employed a type of qualitative research, with data collection techniques in the form of observation and documentation in several examples of buildings that applied the GRC material innovation. Data analysis was obtained from observation related to GRC types, sizes, installation techniques, and functions in the building. Results showed that the GRC had various types, shapes, and sizes. It could be applied to the building exterior or interior. Each building used different GRC specifications tailored to meet needs and design of the building. GRC installation techniques could use the frame or without frames, adapted to the needs and types of GRC used
Dynamic Analysis of a Francis Turbine

Using software to simulate behavior of structures and components has been an important tool in engineering for the last decades. The demand for more complex applications has arisen and the software has developed simultaneously, thanks to the exponentially growth of faster computers. This implies that one has the possibility to do what was previously unthinkable, on a regular computer. Numerical analysis of complex geometries such as a Francis turbine interacting with a fluid are still reserved high-end hardware, and not applicable to laptops. Simplified geometries are therefore considered to keep simulation time at an acceptable level. Fluid-structure interaction (FSI) couples the structural dynamics with the fluid dynamics and letting them interact with each other. From a two-way coupling it is also possible the separately examine the behavior, due to the fact that in some cases the fluid dynamics are of interest and in other cases it is the structural dynamics which are of interest. For the situation with an immersed steel structure with a surrounding fluid and with only interest of the dynamics of the steel structure, the problem can be simulated in different ways. This master thesis contains a coupled acoustic-structure (CAS) numerical analysis and a coupled Eulerian-Lagrangian (CEL) numerical analysis. The simulations are executed in Abaqus 2017 software and primary focus will be at the structural response and energies. Comparison of the different approaches indicates that the CAS technique is slightly more accurate from a numerical point of view, has easier setup and requires less processor power. Nevertheless the CAS technique is not that versatile and unable to simulate real situations, due to the use of acoustic elements. The CEL technique offers more input parameters and easy access for changing the parameters of the fluid. A complete overview of the fluid flow is also available. Complex setup, no possibility for re-meshing and a need for using small elements in the Eulerian domain are the drawbacks.
Physical activity and physical function in older adults living in a retirement community or single family dwellings

The primary purpose of the study was to compare the home size to a person’s daily level of physical activity (measured by the StepWatch 3.1) and physical function (measured by the Continuous Scale Physical Functional Performance Test). Older adults ( x̄ = 79.4 years) living in a retirement community (RC) (N = 30) or community dwellers (CD) (N = 31) living in a single family dwelling were examined. The living space of the RC ( x̄ = 68.72 m) was smaller than the CD ( x̄ = 178.97 m) (p = 0.001). After correcting for age, the RC took fewer total steps per day excluding exercise (p = 0.03) and had lower function (p = 0.005) than CD. In conclusion, the smaller living space and lower function were the primary contributors to the fewer steps per day taken by the RC.
SiC‐based active quasi‐Z‐source inverter with improved PWM control strategy

In this study, an improved pulse width modulation (PWM) scheme was proposed for an active quasi-Z source inverter (AqZSI). Compared to the quasi-Z-source inverter (qZSI), the AqZSI with improved PWM strategy can operate in a wide range of input voltage with higher efficiency. Furthermore, the AqZSI can operate with a higher modulation index, a lower inductor current stress, and a reduced shoot-through current. A procedure flowchart is presented for the optimal selection of the shoot-through duty cycle, the switching ratio of the additional switch, and the modulation index for AqZSI. Moreover, some comparative results between the AqZSI, qZSI and conventional two-stage inverter with a boost DC–DC converter are shown in detail. Finally, 1.2 kVA SiC-based three-phase inverter prototypes are built to verify the agreement between theory and measurement.
Design and implementation of a novel nine‐level MT‐MLI with a self‐voltage‐balancing switching technique

In this study, a novel nine-level modified T-type multilevel inverter (MT-MLI) with a simple capacitor balancing technique is proposed. The proposed MT-MLI circuit can generate higher levels with a single DC source and the minimum number of switching components. Each phase of the proposed topology contains ten switches and one flying capacitor (FC). The DC source voltage is divided into two parts with the help of capacitors. Phase disposition-sine pulse-width modulation technique is employed to regulate the DC-link capacitors and FC voltages. To reduce the control complexity of FC-based circuits, quarter-cycle selector is introduced to control the FC voltage within the given half fundamental cycle using redundant states, so an external capacitor charging setup is not required. Furthermore, to highlight the potential merits of the proposed MT-MLI, the comparison is made among state-of-the-art MLIs. Simulation verification of the MT-MLI is done using MATLAB/Simulink, and then hardware verifications are done using the laboratory prototype setup with Opal-RT controller. Finally, adequate results are presented to validate the proposed MT-MLI.
Modified Low Rank Approximation for Detection of Weak Target by Noise space Exploitation in Through Wall Imaging

Low dielectric materials referred as weak targets are very difficult to detect behind the wall in through wall imaging (TWI) due to strong reflections from wall. TWI Experimental data collected for low dielectric target behind the wall and transceiver on another side of the wall. Recently several researchers are using low-rank approximation (LRA) for reduction of random noise in the various data. Explore the possibilities of using LRA for TWI data for improving the detection of low dielectric material. A novel approach using modification of LRA with exploiting the noise subspace in singular value decomposition (SVD) to detect weak target behind the wall is introduced. LRA consider data has low rank in f-x domain for noisy data, local windows are implemented in LRA approach to satisfy the principle assumptions required by the LRA algorithm itself. Decomposed TWI data in the noise space of the SVD to detect the weak target adaptively. Results for modified LRA for detection of weak target behind the wall are very encouraging over LRA.
Measuring continuous-variable quantum entanglement with parametric-amplifier-assisted homodyne detection

Traditional method for measuring continuous-variable quantum entanglement relies on balanced homodyne detections, which are sensitive to vacuum quantum noise coupled in through losses resulted from many factors such as detector's quantum efficiency and mode mismatching between detected field and local oscillator. In this paper, we propose and analyze a new measurement method, which is realized by assisting the balanced homodyne detections with a high gain phase sensitive parametric amplifier. The employment of the high gain parametric amplifier helps to tackle the vacuum quantum noise originated from detection losses. Moreover, because the high gain parametric amplifier can couple two fields of different types in a phase sensitive manner, the proposed scheme can be used to reveal quantum entanglement between two fields of different types by using only one balanced homodyne detection. Furthermore, detailed analysis shows that in the multi-mode case, the proposed scheme is also advantageous over the traditional method. Such a new measurement method should find wide applications in quantum information and quantum metrology involving measurement of continuous variables.
A Comprehensive Load Flow Approach for Grid-Connected and Islanded AC Microgrids

This paper proposes a comprehensive load flow algorithm for balanced and unbalanced distribution systems considering the effect of a multi-grounded neutral conductor. The method is based on the implicit ZBUS method presenting fast convergence and robustness regardless of the R/X ratio of the lines. Its distinct feature is its ability to handle all network configurations, including highly meshed distribution systems that operate in either islanded or grid-connected mode. Furthermore, an algorithm is proposed for overcoming the limitation of implicit ZBUS method to treat PV nodes. Additionally, the concept of virtual impedance is incorporated into the proposed algorithm to accurately simulate the behavior of distributed generators (DGs) during the islanded operation. Numerical simulations are conducted in 33-Bus and 38-Bus balanced networks as well as in 25-Bus and 30-Bus unbalanced networks to verify the validity of the proposed load flow algorithm.
Orientation-Aided Stochastic Magnetic Matching for Indoor Localization

Indoor localization using magnetic and inertial sensors has shown its effectiveness due to the pervasiveness of magnetic fields and independence from external infrastructure. However, when massive crowdsourced data are obtained in mass-market applications, new issues occur and degrade the magnetic matching (MM) performance. To alleviate these issues, an orientation-aided stochastic MM method is presented. First, orientation-aided magnetic fingerprints are applied to effectively improve fingerprint fidelity when massive data are used. Second, this paper characterizes crowdsourced magnetic fingerprints and reveals that the stochastic magnetic components may have different histograms, such as the symmetric, left-skewed, bimodal, and irregular ones. Based on such outcome, Gaussian distribution and histogram model based stochastic MM methods are presented to mitigate the degradation from stochastic magnetic components, which have not been involved in the existing MM methods such as nearest neighbor and dynamic time warping. Compared to the deterministic MM methods, this research provides a deeper insight into the use of magnetic fingerprints and more accurate MM and MM/dead-reckoning integrated localization solutions.
Optimal Investment of Electrolyzers and Seasonal Storages in Hydrogen Supply Chains Incorporated With Renewable Electric Networks

Converting surplus renewable electricity into hydrogen by electrolyzers has been recognized as a promising scheme to reduce renewable energy spillage and to meet the increasing hydrogen demand. However, the scheme is challenged by the inherent spatiotemporal imbalance between renewable energy and hydrogen demand. Seasonal storages and interregional hydrogen supply chains (HSCs) are commonly employed in the literature to eliminate this imbalance, but long-distance hydrogen transportation can be costly. In this paper, we incorporated the electric network (EN) into the HSC for its ability to promptly and economically deliver energy at long distances. The uniform hierarchical time discretization method is utilized to achieve the unified operation of the HSC and the EN. On this basis, an integrated HSC-EN model is elaborated upon to investigate the optimal investment and operation of electrolyzers and storage. Finally, an industrial case in Sichuan province, China is analyzed to illustrate the benefits of incorporating the EN to reduce the investment cost and improve electrolyzers’ utilization.
Secure On-Off Transmission in UAV Relay-Assisted mmWave Networks

This paper investigates secure transmission in unmanned aerial vehicle (UAV) relay-assisted millimeter wave (mmWave) networks, where the selected UAV relay performs secure transmission in both the on-off and non-on-off schemes. Meanwhile, there are multiple eavesdroppers randomly distributed on the ground and attempting to wiretap the transmission. Leveraging the air-to-ground channel model and the tools of stochastic geometry, the novel expressions of transmit probability (TP) and secrecy outage probability (SOP) are derived in both the on-off and non-on-off transmission schemes with perfect beam alignment. The secrecy performance improvement is demonstrated in the on-off transmission scheme, and we find that there exists an optimal altitude of UAV relays to achieve the best TP. In addition, due to the limitations of UAV carriers, such as its low computational capacity and high mobility, the perfect beam alignment is difficult to achieve in the mmWave networks aided by UAV relays, and the effect of beam alignment error on the secrecy performance is investigated in the considered networks. Analyzing the numerical and simulation results, we find that the SOP will not have obvious deterioration when the beam alignment error is relatively small, and the SOP can be improved by using the antennas with a large number of elements. However, in high beam alignment error regime, the antenna arrays with a smaller number of elements will provide the better SOP.
Automatic Detection and Segmentation of Laser Stripes for Industrial Measurement

Laser stripes play an important role in industrial vision measurement as the major auxiliary feature. The existing research works mainly focused on the application of small size parts. However, with the increase of field of view (FOV), it is difficult to extract laser stripes robustly in varying field measurement situations because of the complex background, low proportion, and uneven characteristic of laser stripes. To increase the measurement adaptability in a complex environment, an automatic laser stripe detection and segmentation algorithm is proposed. First, the data set is constructed by a large number of image patches collected in the field and laboratory, and laser stripe patches in the imbalanced dataset are expanded by the data augmentation method. Next, the detection of the laser stripe is initially realized based on the training results of the convolutional neural network (CNN), and then the laser stripe is accurately detected by nonfeature filtering criteria based on area constraints. Finally, a subregional feature clustering method is proposed to realize effective segmentation of uneven laser stripes. A large number of verification experiments have been carried out in both the laboratory and field, and the results show that the proposed method can achieve automatic and accurate extraction of laser stripes, which has strong adaptability to both the complex background in the field and the uneven brightness characteristic of laser stripes, thereby satisfying the engineering requirements of large-scale part field measurement.
A Comparison of the Predictive Validities of Single- and Dual-Task Measures

An experiment comparing the predictive validity of single-versus dual-task measures is reported. Fifty-seven males received two trials on each of two identical one-dimensional compensatory tracking tasks followed by 25 dual-task trials. Finally, they performed each task alone for one trial. The subjects then were given a short basic flight course consisting of ground instruction and practice in a GAT-2 simulator. After completing the course, the subjects performed four repetitions of three maneuvers. Performance in the simulator then was correlated with performance on each tracking trial. The predictive validity of the early single-task scores decreased with practice while the dual-task validity increased throughout the testing session. However, the predictive validity of the late single-task scores was almost as large as that of the late dual-task scores.
Automated tool for 3D planar magnetic temperature modelling: application to EE and E/PLT core‐based components

Thermal performance of power converters is a key issue for the power integration. Temperatures inside the active and passive devices can be determined using thermal models. Modelling the temperature distribution of high-frequency magnetic components is quite complex due to the diversity of their geometries and used materials. This study presents a thermal modelling method based on lumped elements thermal network model, applied to planar magnetic components made of double planar E shaped cores (EE) and planar E core combined with plate one (E/PLT). The 3D model is automatically generated from the component's geometry. The computation enables to obtain 3D temperature distribution inside windings and core of planar transformers or inductors, in steady state or in transient case. This study details the proposed modelling method as well as the automated tool including the problem definition and the solving process. The obtained temperature distributions are compared with finite-element simulation results and measurements on different planar transformers.