bluuebunny/crossref_metadata_2025 huggingface dataset:
Weakly supervised classification model for zero‐shot semantic segmentation
Authors: Shen Fengli , Wang Zong‐Hui , Lu Zhe‐Ming
Published: September 2020

As one of the most fundamental tasks in computer vision, semantic segmentation assigns per pixel prediction of object categories. Training a robust model for semantic segmentation is challenging since pixel‐level annotations are expensive to obtain. To alleviate the burden of annotations, the authors propose a weakly‐supervised framework for zero‐shot semantic segmentation, which can segment images having target classes without any pixel‐level labelled instances. Under the assumption that the accessibility to image‐level annotations of target classes does not violate the principle of zero pixel‐level label in zero‐shot semantic segmentation, we utilised image‐level annotations to improve the proposed model's ability to extract pixel‐level features. Furthermore, unlike existing zero‐shot semantic segmentation methods, which use semantic embeddings as class embeddings to transfer knowledge from source classes to target classes, we use image‐level features as their class embeddings to transfer knowledge since the distribution of pixel‐level features is more similar to the distribution of image‐level features rather than the distribution of semantic embeddings. Experimental results on the PASCAL‐VOC data set under different data splits demonstrate that the proposed model achieves promising results.
Methodology to incorporate stuck condition of the circuit breaker in reliability evaluation of electrical distribution networks
Authors: Raj Timalsena Kiran , Karki Rajesh , Bhattarai Safal
Published: September 2020

The random failure of a circuit breaker (CB) in a power distribution network adversely impacts its ability to maintain supply continuity to its electricity customers. Among different CB failure modes, the failure to open, or the stuck condition, of a normally closed CB causes the operation of its backup breaker(s) leading to outages of multiple healthy feeders. Stuck condition is a low‐probability failure event, but has wide‐spread consequences when it occurs. This study proposes a generalised analytical methodology to identify the failure events due to the stuck breaker condition. The complexity of the reliability evaluation of a modern distribution system involving multiple switching arrangements is achieved through a search algorithm and repeated matrix operations that can readily be implemented in a computer program. The methodology is illustrated using a test distribution network. The usefulness of the methodology is demonstrated by quantifying the impact of the stuck breaker condition on load point and system reliability indices. The developed methodology can be a useful tool for industrial/commercial customers and utilities to incorporate the impact of breaker failures, including stuck breaker conditions, and make wise investment decisions in the upgrade and maintenance of the distribution network components and the protection system.
Transmission and distribution co‐simulation: a review and propositions
Authors: Mohseni‐Bonab Seyed Masoud , Hajebrahimi Ali , Kamwa Innocent , Moeini Ali
Published: September 2020

With the growing trend of emerging new technologies in distribution networks, such as wind turbines, solar panels, electric vehicles, and distributed generations, the passive distribution systems may become ‘active’ which requires more study in the area of integrated transmission and distribution systems (ITDSs) and corresponding bilateral interactions. To solve this problem, most of the studies connect distinct simulators to create a novel co‐simulation framework for ITDS. In this study, the authors present a literature survey of existing ITDS co‐simulation frameworks along co‐optimisation in ITDS. These frameworks are categorised on multiple characteristics, such as simulation tools, synchronisation methods, and research topics. Furthermore, they propose a software platform that is focused on the integrated generation, transmission, distribution, and customer systems (IGTDCSs). The proposed framework also comprises several technological dimensions such as stochastic optimisation, high‐performance computing, and high‐level design software architecture for planning integrated and flexible power networks and optimising their technological trajectories and operational functioning considering uncertainties. By developing a prototype informed with software engineering and complex system design approaches, they will demonstrate the relevance of a unified vision of IGTDCS simulation in a minute‐by‐minute horizon, a vision that may later benefit electromagnetic transient simulation or stability co‐simulation tools, in horizons from the microsecond to the second.
Development of a new multi‐graded winding to alleviate resonant characteristic of EHV transformers
Authors: De Shampa , De Abhinandan , Bandyopadhyay Gautam
Published: September 2020

Mitigation of winding resonance triggered by oscillatory transient over voltages is one of the key challenges in designing high‐voltage transformer windings. Internal resonance is typically an issue with high‐voltage transformers with homogeneous winding, manifesting identical natural frequency for the uniform winding sections. Self‐capacitance grading can be a possible remedy to resonance issue which incorporates diversification in the natural frequencies of winding disk coils. Practical implementation of this concept is however difficult due to economic and design constraints. This study proposes a practical method of implementing the concept of natural frequency diversification by use of ‘multi‐graded inter‐winding electrostatic shields’. The concept, theory, design and implementation of the proposed winding method have been presented in this study. A scaled‐down prototype of a typical high‐voltage transformer has been developed to illustrate the real‐time implementation of the proposed method. Both simulation and experimental results established that the proposed winding can effectively suppress oscillatory characteristics under transient over voltages and overcome winding resonance.
Electromagnetic scattering from time‐varying breaking waves generated by FLUENT
Authors: Luo Gen , Xiong Zhihua , Zhou Mingbin , Ren Zhong
Published: September 2020

In this study, a series of time‐varying breaking waves are generated by FLUENT. The backscattering normalised radar cross sections of the time‐varying braking wave at different incidence angles are analysed by employing the method of moments. The scattering results can present the high polarisation ratios and sea spikes. In addition, the Doppler spectrums of the breaking waves are calculated for different incidence angles, and the computational results can indicate the large Doppler offsets and relatively big bandwidths for large incidence angles. Generally speaking, the scattering results in this study could play a part in explaining the super‐scattering events from the breaking wave on the sea surface.
Low‐profile ring slot SIW antenna based on higher‐order cylindrical cavity modes
Authors: Aghabeyki Peyman , Moradi Gholamreza , Sarraf Shirazi Reza
Published: September 2020

A novel ring slot substrate‐integrated waveguides (SIW) antenna is presented based on higher‐order cylindrical cavity mode. First, TM02 is used to realise a conical beam antenna. Electric field distribution on slot aperture generates four pairs of magnetic monopoles, each rotated 90° with respect to the centre of the cavity, resulting in a conical beam. By applying an offset to the feed point, the loading effect of slots generates a hybrid mode, which is a combination of TM31 and TM12. The hybrid mode aligns the magnetic monopoles; thus, a high‐gain antenna with broadside radiation can be realised. The measured results show a 10.5% impedance bandwidth, 11.5 dBi gain, and 90% radiation efficiency. The proposed antenna is low‐profile and compact with a planar structure that could be integrated with other planar circuits; therefore, it could have many practical applications in communication systems.
RCS reduction of microstrip antenna using split square loop thin absorber
Authors: Das Priyanka , Mandal Kaushik
Published: September 2020

This study proposes an electrically thin frequency‐selective surface‐based microwave absorber without using resistive surface and lumped resistors to make it simple and inexpensive. The ground plane of the microstrip antenna (MSA) serves as the metallic back of the absorber. The top two layers of the proposed absorber are printed on both sides of the top FR4 sheet in a square annular ring form to encircle the square patch. Both simulations and measurements are carried out to obtain the scattering parameters, which are used to retrieve the absorption coefficient, relative permittivity (ɛr), and relative permeability (μr). An equivalent circuit model for the proposed absorber is constructed and validated. The absorption performance is insensitive to the angle of incidence (θ) up to 50°. The absorption mechanisms are studied based on the surface current distribution, electric field distribution, and constitutive parameters. The absorber is then integrated with an MSA operating at 4.2GHz, which gives a maximum monostatic radar cross‐section (RCS) reduction of 15dB. Numerical and experimental results of the radiation performance and the RCS of the absorber integrated antenna structure have been presented. A very good agreement between simulation and measurement results is observed.
Dual‐band polarisation reconfigurable grounded fractal slot antenna
Authors: Saraswat Kapil , Harish Ayyangar R.
Published: September 2020

A polarisation reconfigurable fractal slot antenna with dual‐band performance is proposed in this study. The antenna consists of a Minkowski Island fractal inspired slot in the ground plane, which is excited by a microstrip line. The input match of the antenna is improved by placing two protruding horizontal stubs inside the two corners of the fractal slot. Four p‐i‐n diodes are placed within the grounded fractal structure to realise polarisation reconfigurability. Based on the switching states of the p‐i‐n didoes, the proposed antenna can produce right‐hand circular polarisation or left‐hand circular polarisation. A novel biasing network is used, which uses only two wires for polarisation switching. A prototype of the proposed antenna is fabricated and tested. When the antenna is configured to radiate circular polarisation, the measured reflection coefficient bandwidths (corresponding to  dB) for the two bands are 15.44 and 13.16% and the measured axial ratio bandwidths (corresponding to AR 3 dB) are 17.61 and 8.69%, respectively.
Wideband circularly polarised antenna based on interelement mutual coupling effect
Authors: Zhou Peng , Huang Qiu‐Lin , Yang Lin , Li Xi , Shi Xiao‐Wei
Published: September 2020

This study presents a circularly polarised (CP) antenna with a wideband characteristic, which is caused by the interelement mutual coupling effect. The proposed antenna consists of a dipole array with four elements in centre symmetry and a wideband feed network. In order to extend the lowest working frequency, a strong mutual coupling effect is introduced to the adjacent co‐polarisation elements. What's more, the introduced effects of capacitive coupling reactance counteract the effects of the element's inductively reactive ground plane. Then, a small, tightly coupled array is formed that possesses wide impedance bandwidth and orthogonal polarisation component. A wideband feed network, including Wilkinson power dividers, phase shifters, and impedance converters, is designed to provide amplitudes and phases excitation that circular polarisation antenna required. Finally, a prototype is fabricated and tested. Measured results show a VSWR<2 impedance bandwidth of 102.7% (2.09–6.5 GHz) and a 3‐dB axial ratio bandwidth of 94.2% (2.25–6.25 GHz). Besides, a relatively stable gain is realised across the operating band.
Precision indoor three‐dimensional visible light positioning using receiver diversity and multi‐layer perceptron neural network
Authors: Mahmoud Abdulrahman A. , Ahmad Zahir Uddin , Haas Olivier C.L. , Rajbhandari Sujan
Published: September 2020

In recent times, several applications requiring highly accurate indoor positioning systems have been developed. Since the global positioning system is unavailable/less accurate in the indoor environment, alternative techniques such as visible light positioning (VLP) are considered. The VLP system benefits from the wide availability of illumination infrastructure, energy efficiency and the absence of electromagnetic interference. However, there is a limited number of studies on three‐dimensional (3D) VLP and the effect of multipath propagation on the accuracy of the 3D VLP. This study proposes a supervised artificial neural network to provide accurate 3D VLP whilst considering multipath propagation using receiver diversity. The results show that the proposed system can accurately estimate the 3D position with an average root mean square (RMS) error of 0.0198 and 0.021 m for line‐of‐sight (LOS) and non‐LOS link, respectively. For 2D localisation, the average RMS errors are 0.0103 and 0.0133 m, respectively.
Gain‐flattened hybrid EDFA operating in C + L band with parallel pumping distribution technique
Authors: Al‐Azzawi Alabbas A. , Almukhtar Aya A. , Dhar Anirban , Paul Mukul C. , Ahmad Harith , Altuncu Ahmet , Apsari Retna , Harun Sulaiman Wadi
Published: September 2020

A novel C + L band hybrid erbium‐doped fibre amplifier (EDFA) using a two‐stage configuration was proposed and demonstrated experimentally. The amplifier is composed of a 0.5‐m long hafnium bismuth erbium co‐doped fibre (EDF) to provide gain within the C‐band and a 4‐m long zirconia‐based EDF to provide gain within the L‐band. The proposed amplifier was examined based on the multi‐wavelength input source. A parallel pumping distribution technique was used to mitigate the amplifier complexity. The C + L band amplifier achieved a gain flattening of over 55 nm bandwidth for the three levels of the input powers. A gain‐flattening of roughly 10.9, 15.5, and 19.2 dB were obtained, respectively, for the input signal powers of −5, −10, and −15 dBm. An average noise figure of 6.4, 5.4, and 4.7 dB was achieved, respectively, for the input signal powers of −5, −10, and −15 dBm.
Alleviating the right‐half‐plane zero effect on Z‐source converter output voltage regulation using the cascaded sliding mode controller
Authors: Ahmadzadeh Soheil , Arab Markadeh Gholamreza , Abjadi Navidreza
Published: September 2020

This study presents the cascaded variable structure control approach with respect to the non‐minimum phase nature of the DC–DC Z‐source converter (ZSC). The method is based on the sliding mode control technique for output voltage regulation. The control‐to‐output transfer function of the ZSC contains a right‐half‐plane (RHP) zero in continuous conduction mode. The RHP zero, obtained by a linearised small‐signal model, results in frequency response limitation. In this case, the converter output voltage control should be studied regarding to the RHP zero effect. To alleviate this effect and enhance the dynamic performance, the cascaded sliding mode control method is proposed. The cascaded sliding mode controller guarantees asymptotically minimum phase stability as well as robustness against input voltage variation and load resistance uncertainty. The capability and effectiveness of the proposed control method are supported by experimental results.
Predictive torque control of induction motor with integrated DC‐link voltage optimisation
Authors: Karlovsky Pavel , Lipcak Ondrej , Bauer Jan , Lettl Jiri
Published: September 2020

This study proposes a new method leading to a reduction in the current and torque ripple of an induction motor (IM) drive controlled by predictive torque control (PTC). The method lies within the optimisation of a DC‐link voltage magnitude by the PTC cost function. Using a three‐phase silicon‐controlled rectifier, the DC‐link voltage can be adjusted in such way that the current and torque ripple, caused mainly by treating the inverter as a source of only eight voltage vectors, is significantly reduced. The DC‐link optimisation algorithm is integrated into the PTC that is used for the torque and flux control. In another prediction stage, the influence of the DC‐link voltage on the torque and flux ripple is directly evaluated and then optimised by a second cost function. The theoretical analysis of the DC‐link voltage influence on the drive behaviour is supported by simulation and experimental results conducted on a 5.5 kW IM drive, which confirm the benefits of the PTC with the DC‐link voltage optimisation, especially if the drive operates in a region below the nominal speed.
Analysis and design of LLC resonant converter with variable magnetising inductance control
Authors: Wei Yuqi , Luo Quanming , Chen Jian , Alan Mantooth Homer
Published: September 2020

A conventional pulse frequency modulation (PFM) controlled LLC resonant converter requires a wide switching frequency operating range to regulate the output voltage. There are some disadvantages of PFM LLC resonant converters: (i) the design and optimisation of magnetic components and gate driver circuitry are challenging; (ii) due to the variable switching frequency operating range, electro‐magnetic interference performance of the converter is degraded; (iii) efficiency degradation; (iv) inability to achieve independent control in multiple‐output applications. To address the above‐mentioned problems and achieve fixed switching frequency operation, a variable magnetising inductance control (VMIC) strategy is proposed. In the proposed VMIC control strategy, the operating switching frequency of the primary switch is fixed and the duty cycle remains constant at 0.5. At the resonant frequency operating point, the output voltage is independent of both the magnetising inductance and load. In addition, the zero current turn‐off operation of the secondary rectifier requires that the switching frequency be designed below the resonant frequency. The operational principles and design considerations of the LLC resonant converter with VMIC are presented. Experimental results from a 200 W prototype are presented to validate the theoretical analysis and the effectiveness of the proposed VMIC control strategy.
Analytical estimation of parasitic capacitances in high‐voltage switching transformers
Authors: Mirzadarani Reza , Mohammadi Hamid Reza , Ketabi Abbas , Motahari Seyed Reza , Ghorbani Alimorad
Published: September 2020

Parasitic capacitances in transformers consist of three main groups: winding‐to‐winding, layer‐to‐layer, and stray capacitances. Stray capacitance is also made of turn‐to‐turn and turn‐to‐core capacitances. This study presents a novel analytical method for calculating the values of turn‐to‐turn, turn‐to‐core, and stray capacitances in each winding, and employs the results to calculate the equivalent parasitic capacitance especially for high‐voltage switching transformers. The proposed analytical method introduces an explicit formula in terms of the winding and core dimensions. This formula can be applied in performance analysis and design optimisation methods. By utilising the proposed formula, calculation of the equivalent parasitic capacitance neither takes a great deal of time nor requires a particular computer system. The analytical results are verified by simulation results using the finite‐element method and experimental results achieved by a practical prototype of a high‐voltage switching transformer employed in a 390 W, 15 kV inductor–capacitor–inductor–capacitor resonant converter.
Soft‐switching and sensorless voltage balancing modulation for unidirectional modular multilevel DC–DC converter
Authors: Zheng Gengzhe , Chen Yu , Chen Ziduo , Kang Yong
Published: September 2020

DC–DC converters are important in medium‐voltage direct current (MVDC) distribution networks. For the scenarios where energy flows unidirectionally from MVDC distribution networks to low‐voltage direct current (LVDC) loads, the DC–DC converter, which composes of a modular multilevel converter (MMC) on the MVDC side, an uncontrolled rectifier on the LVDC side and a high‐frequency transformer as the AC link, is the most cost‐efficient candidate. In this study, a new modulation method with quasi‐triangular AC‐link current is presented to realise zero‐voltage turning‐on for all switches on the MVDC side, as well as zero‐current‐switching for the uncontrolled rectifier on the LVDC side. Besides, by adding simple and low‐cost voltage‐balancing D‐L auxiliary circuits between adjacent submodules (SMs), all SM capacitor voltages can be well balanced without voltage sensors. The validity and effectiveness of the proposed method are verified by the simulation and experimental results.
Effects of the LED modelling on the output capacitance of power converters
Authors: Salazar‐Pérez Daniel , Ponce‐Silva Mario , Aqui‐Tapia Juan Antonio , García‐Guzmán Jesús , Pérez‐Cruz Jose Humberto
Published: September 2020

The main contribution of this study is to show the effect of light‐emitting diode (LED) modelling in the design of offline drives. The authors propose the use of a source voltage and resistance model (SVRM), consisting of a threshold voltage source in series with the characteristic resistance, for the modelling of the LED. The offline drive used for the analysis is the flyback converter operating in discontinuous conduction mode. The equivalent circuit is analysed by superposition and the AC circuit is analysed with phasors. The analysis has proven that the flyback converter can be modelled as a current source feeding the output capacitor in parallel with the load. Likewise, the analysis demonstrated that the current ripple is always greater than the voltage ripple when an LED is used as a load. In order to validate the theoretical analysis, a design methodology for the flyback converter with the SVRM as a load was developed. The designed circuit was simulated in Spice and implemented in a prototype. Experimental results using an LED as load are compared with the same circuit using a simple resistance as load. The experimental results confirm the theoretical analysis with an error of <6.6%.
Interaction characteristics between multi‐port hybrid DC circuit breaker and MVDC distribution system under diversified working conditions
Authors: Wen Weijie , Li Pengyu , Cao Hong , Liu Haijin , Wang Xingguo , Lv Hui , Li Bin , Popov Marjan
Published: September 2020

Due to the progressive penetration and usage of renewable sources and loads based on power electronics, medium voltage direct current (MVDC) distribution system is getting broad attention. Direct current circuit breakers (DCCBs) are of vital importance for the reliability and flexibility of power system. With features of low cost and micro‐operating losses, multi‐port hybrid DCCB with negative voltage source (NVS) has been proposed by the authors and might be a better choice. To further promote its industry application in MVDC system, interaction characteristics between DCCB and power system are investigated in this study. The structure of multi‐port hybrid DCCB is briefly introduced. Then, considering the diversified working conditions, e.g. single fault, multiple faults and switching load current with random direction, the cooperation sequence of components in multi‐port DCCB under all these working conditions is proposed, respectively. Then, based on simulation model established in PSCAD/EMTDC, transient current/voltage distribution pattern inside multi‐port DCCB and its mechanism are discussed, and simulation results have verified the superiority and effectiveness of multi‐port hybrid DCCB with NVS in MVDC system.
Decentralised coordinated energy management for hybrid AC/DC microgrid by using fuzzy control strategy
Authors: Lv Zeyan , Zhang Yong , Yu Miao , Xia Yanghong , Wei Wei
Published: September 2020

The islanded hybrid AC/DC microgrid consisting of battery energy storage (BES) systems, photovoltaic (PV) generators, and bidirectional power converter (BPC) possesses the advantages of flexibility and extendibility. To ensure the safety and stability of operation, the power of BES and BPC needs to be restrained within their designed limits regardless of the power fluctuation in the hybrid microgrid. Besides, the over‐charge and over‐discharge of BES should be prohibited. In this study, a decentralised generation‐storage‐subgrid coordination control for power management is proposed to assure the power limitation and state of charge (SOC) protection. In the control strategy of BES, a modified droop method is adopted to deliver the storage's both SOC and output power signals without communication links. Meanwhile, a fuzzy logic controller is adopted in BPC, which can prevent the overuse of BESs in both subgrids and limit the maximum output power of BPC. In addition, a modified P&O strategy is applied in PV systems as a supplement of overuse protection. Finally, the effectiveness of the proposed control strategy is verified on RT‐Lab experimental platform.
Joint optimisation of sizing and fuzzy logic power management of a hybrid storage system considering economic reliability indices
Authors: Krim Youssef , Abbes Dhaker , Robyns Benoit
Published: September 2020

This study is interested in optimisation of both sizing and energy management system of a hybrid storage system (HSS) associated with photovoltaic panels. The battery (BT) considered as the principal storage organ and a super‐capacitor used as the secondary storage system to improve the BT life span makes up the HSS. The main purpose of this study is to explore a novel optimisation approach to jointly optimise the sizing and the fuzzy logic energy management system (FLEMS). In fact, an optimisation function based on sequential quadratic programming algorithm is proposed. The optimisation methodology has been performed jointly and successfully for the sizing of the BT storage system and the membership functions parameters of the FLEMS in order to decrease the levelised cost of energy with a violation time by 5% of mean absolute percentage error score <1.5% throughout the year. According to the simulations results, a benefit analysis has been done to assess the associated financial impact.
Vital signs monitoring using pseudo‐random noise coded Doppler radar with Delta–Sigma modulation
Authors: Abouzaid Salah H. , Ahmad Wael A. , Eibert Thomas F. , Ng Herman Jalli
Published: September 2020

A distance selective pseudo‐random noise (PRN)‐coded Doppler radar is proposed. The radar is capable of measuring the vital signs of a human in a noisy environment with high precision. The distance selectivity feature is achieved by the use of PRN modulation to focus on the desired target at a certain distance and suppress the Doppler frequencies of other targets at different distances. In addition, an offset signal using Delta–Sigma modulation is generated to cope with the suppression of low‐Doppler frequencies, very close to DC, in AC‐coupled systems. The authors compare the performance of the proposed radar system to a frequency modulated continuous wave radar in measuring the Doppler frequencies of two loudspeakers located at different ranges. In addition, they experimentally evaluated the proposed radar in measuring the vital signs of a human in a noisy environment. The radar is capable of isolating the Doppler frequencies of the vital signs from the surrounding noise. In addition, vital signs information is preserved at higher frequencies away from the high‐pass filter in AC‐coupled systems.
Testing of VoLTE mean opinion score in reverberation chambers
Authors: Barazzetta Massimo , Colombo Michele , Bastianelli Luca , Moglie Franco , Mariani Primiani Valter , Diamanti Riccardo , Micheli Davide
Published: September 2020

In this study, the authors present results of a call testing campaign using voice over long term evolution (VoLTE) technology on the radio access network of the operator Telecom Italia mobile. The quality of the voice call is expressed by means of the mean opinion score (MOS). The electromagnetic propagation environment has been reproduced within a reverberation chamber, and its effect on MOS has been evaluated by varying the signal strength, i.e. the reference signal received power and the signal‐to‐interference noise ratio. The aim is to find a correlation between the radio propagation environment and the perceived quality of the speech. Regardless of the networks technology, voice quality could be impacted by several factors: traffic load of LTE evolved Node B, quality of service, radio pathloss, mutual radio interference, multipath and so on. Interference and multipath are added to the useful signal in order to deteriorate the MOS, until the VoLTE calls dropped. Target of such work is to properly set the thresholds that trigger a handover of single radio voice call continuity to other radio access technologies (UMTS or GSM). Tests take also into account the adaptive multi‐rate CoDec selected by the network.
GIS partial discharge pattern recognition via lightweight convolutional neural network in the ubiquitous power internet of things context
Authors: Wang Yanxin , Yan Jing , Yang Zhou , Zhao Yiming , Liu Tingliang
Published: September 2020

The construction of the ubiquitous power internet of things (UPIoT) provides a new feasible solution for gas‐insulated switchgear (GIS) online monitoring and fault diagnosis, but it also puts forward greater requirements for time and accuracy. How to find an effective real‐time model that can be applied to the UPIoT mobile terminals has become an urgent problem needing to be solved. To this end, this study proposes a lightweight convolutional neural network (LCNN) for GIS partial discharge (PD) pattern recognition using three lightweight convolutional blocks, and introduces the lowest recognition accuracy of single‐class faults as the primary indicator for selecting the optimal model under the UPIoT. First, three lightweight convolutional blocks are introduced for constructing an LCNN. Then, the optimal model constructed by the lightweight blocks is sought. Next, criteria for determining the best model are introduced, and the best model under the UPIoT is selected. This study provides a reference standard for the construction of GIS PD pattern recognition under the UPIoT. Meanwhile, through the balance of evaluation indicators, this study verifies that the minimum recognition accuracy of the MnasNet model is 98.8%, which is obviously better than other methods and lays a solid foundation for GIS PD pattern recognition.
Accuracy of meteor positioning from space- and ground-based observations
Authors: Chen Hongru , Rambaux Nicolas , Vaubaillon Jérémie
Published: September 2020

Aims. The knowledge of the orbits and origins derived from meteors is important for the study of meteoroids and of the early solar system. With an increase in nano-satellite projects dedicated to Earth observations or directly to meteor observations (e.g., the Meteorix CubeSat), we investigate the stereoscopic measurement of meteor positions using a pair of cameras, one deployed in space and one on the ground, and aim to understand the accuracy and the main driving factors. This study will reveal the requirements for system setups and the geometry favorable for meteor triangulation.

Methods. This Letter presents the principle of the stereoscopic measurement from space and the ground, and an error analysis. Specifically, the impacts of the resolutions of the cameras, the attitude and orbit determination accuracy of the satellite, and the geometry formed by the moving target and observers are investigated.

Results. To reach a desirable positioning accuracy of 1 km it is necessary to equip the satellite with high-accuracy sensors (e.g., star tracker and GPS receiver) to perform fine attitude and orbit determination. The best accuracy can occur when the target is at an elevation of 30° with respect to the ground station.
The principle of maximum entropy explains the cores observed in the mass distribution of dwarf galaxies
Authors: Sánchez Almeida Jorge , Trujillo Ignacio , Plastino Angel Ricardo
Published: September 2020

Cold dark matter (CDM) simulations predict a central cusp in the mass distribution of galaxies. This prediction is in stark contrast with observations of dwarf galaxies that show a central plateau or “core” in their density distribution. The proposed solutions to this core-cusp problem can be classified into two types. One invokes feedback mechanisms produced by the baryonic component of the galaxies and the other assumes that the properties of the dark matter particle depart from the CDM hypothesis. Here we propose an alternative yet complementary explanation. We argue that cores are unavoidable in the self-gravitating systems of maximum entropy that result from non-extensive statistical mechanics. Their structure follows from the Tsallis entropy, which is attributed to systems with long-range interactions. Strikingly, the mass density profiles predicted by such thermodynamic equilibrium match the observed cores without any adjustment or tuning. Thus, the principle of maximum Tsallis entropy explains the presence of cores in dwarf galaxies.
Effect of Plate Type and Working Length on a Synthetic Compressed Juxta-Articular Fracture Model
Authors: Bird Guy , Glyde Mark , Hosgood Giselle , Hayes Alex , Day Rob
Published: September 2020

Objective This investigation compared the biomechanical properties of a 2.0 mm locking compression notched head T-plate (NHTP) and 2.0 mm straight locking compression plate (LCP), in a compressed, short, juxta-articular fragment fracture model.

Methods Two different screw configurations were compared for the NHTP and LCP, modelling short (configuration 1) and long working length (configuration 2). Constructs were tested in compression, perpendicular and tension four-point bending and torsion. Plate surface strain was measured at 12 regions of interest using three-dimensional digital image correlation. Stiffness and strain were compared.

Results The LCP was stiffer than the NHTP in all three planes of bending (p < 0.05). The NHTP was stiffer than the LCP in torsion (p < 0.05). The NHTP had greater strain than the LCP during compression bending and torsion (p < 0.0005). The short working length NHTP was stiffer in all three planes of bending and in torsion (p < 0.05) than the longer working length. The short working length LCP was stiffer in compression bending and in torsion (p < 0.05) than the longer working length. The long working length showed greater strain than the short working length at multiple regions of interest.

Conclusion In this experimental model of a compressed transverse fracture with a juxta-articular 9 mm fragment, a 2.0 mm LCP with two hybrid screws in the short fragment was stiffer than a 2.0 mm NHTP with three locking screws in the short fragment in three planes of bending but not torsion. Extending the working length of each construct reduced construct stiffness and increased plate strain.
Antecedents of intentional and incidental exposure modes on social media and consequences for political participation: a panel study
Authors: Nanz Andreas , Heiss Raffael , Matthes Jörg
Published: September 2020

This study investigates antecedents and consequences of incidental and intentional exposure behavior to political information on social media. Based on the Social Media Political Participation Model (SMPPM), we investigated how political and non-political motivations predict intentional and incidental exposure modes while accounting for moderators (i.e., personal curation skills and the frequency of social media political exposure). We also examined how intentional and incidental exposure modes affect low- and high-effort political participation. We rely on data from a two-wave panel survey based on representative quotas for the Austrian population (N = 559) to run autoregressive models. Political information motivation predicted the intentional mode, and this relationship was stronger with rising levels of curation skills. By contrast, entertainment and social interaction motivations increased individuals’ incidental exposure mode. The intentional mode led to low-effort political participation but not to high-effort participation. However, the incidental mode was unrelated to both low- and high-effort participation.
How does playing position affect fatigue‐induced changes in high‐intensity locomotor and micro‐movements patterns during professional rugby union games?
Authors: Fornasier‐Santos Charly , Millet Grégoire P. , Stridgeon Paul , Brocherie Franck , Girard Olivier , Nottin Stéphane
Published: September 2020

We questioned whether changes in high‐intensity locomotor and micro‐movements patterns between the first and second part of each half depend on playing position in the 2014–2015 European rugby union championship winning team. Thirty‐three rugby players were grouped according to five playing positions. Players were equipped with micro‐electromechanical system including a GPS sampling at 10 Hz and high temporal resolution micro‐sensors during 17 Top14 and 7 European games. High‐speed movements (HSM), high‐intensity accelerations (HIA), repeated high‐intensity efforts (RHIE), and high‐intensity micro‐movements (HIMM) were subsequently compared between four 20‐min game periods. No significant group × time interactions were observed for any locomotor variables (p > 0.283). Irrespectively of playing position, the number of HSM (p = 0.019), decreased from 0–20 min to 60–80 min as well as from 40–60 to 60–80 min (p < 0.001) with HIA (p = 0.020) and RHIE (p < 0.001). Significant group × time interaction was found for HIMM (p = 0.03) with a significant decrease observed in back row forwards from 0–20 to 60–80 min periods (−17.5%; ES = 0.6; p = 0.031). In elite rugby union, fatigue‐induced changes during the last 20 min are independent from playing positions in high‐intensity locomotor patterns in contrary to HIMM. Training drills that include specific RHIE (high‐speed and HIA efforts) may be useful to postpone match‐related fatigue.
Personality traits, stress appraisals and sleep in young elite athletes: A profile approach
Authors: Nédélec Mathieu , Lienhart Noémie , Martinent Guillaume , Doron Julie
Published: September 2020

The aim of this study was to identify young elite athletes’ personality profiles using a person‐centred approach and to investigate whether the profiles significantly differ in stress and sleep. 260 athletes from a variety of sports completed a questionnaire package to assess neuroticism and conscientiousness traits, stress appraisals (i.e. intensity and directional interpretation of stress, challenge and threat appraisals), and various indicators of sleep (i.e. sleep quality, social jet lag, Ford insomnia response to stress test (FIRST)). A latent profile analysis (LPA) approach was used to identify personality profiles based on the scores of neuroticism and conscientiousness. A multivariate analysis of variance was performed to examine if the athletes belonging to different personality profiles differ on stress appraisals and indicators of sleep. Three profiles emerged: Maladaptive profile (high levels of conscientiousness and neuroticism); Highly adaptive profile (moderate level of conscientiousness and low level of neuroticism); Adaptive profile (high level of conscientiousness and moderate level of neuroticism). Results showed that athletes from the adaptive profile reported significantly lower scores of stress intensity and threat appraisal than those from other profiles. Athletes from the maladaptive profile reported significantly higher levels of FIRST than those from other profiles as well as worse sleep quality and lower levels of challenge appraisal than the athletes from the highly adaptive profile. These results suggest that investigating personality profile may be useful in identifying athletes at higher risk of stress sensitivity and worsening sleep that are likely to benefit from preventive actions (e.g. cognitive behavioural therapy interventions).
The factor affecting heat stress in industrial workers exposed to extreme heat: A case study of methodology
Authors: Rasdan Ismail Ahmad , Jusoh Norfadzilah , Amin Mahd Asri Mohd , Md Zein Raemy , Abdul Rahman Ismail , Kamilah Makhtar Nor , Mohamed Darliana
Published: September 2020

Excessive heat during work creates occupational health risks; it restricts a worker’s physical functions and capabilities, work capacity and productivity. Temperatures above 24–26 °C are associated with reduced labour productivity. Exposure to excessive heat levels can lead to heatstroke, sometimes even with a fatal outcome. The aim of this study is to discuss the methodology in experimental of the factor affecting heat stress in industrial workers exposed to extreme heat. The experiment will be conducted in an environmental chamber which simulates the same environment of the manufacturing industry and another arrangement which simulates the environment of a construction industry. The environmental parameters will be recorded such as the temperature, relative humidity and also the physiological parameters such as the volume oxygen uptake level and the heart rate. The heart rate and the volume of oxygen uptake will be recorded for a 15-minute interval for one shift (2 shift-manufacturing and construction). This study is conducted based on two tasks in two different conditions, outdoor and indoor. It simulates the lifting work at both manufacturing and construction industry. For manufacturing industry, the subjects are demanded to lift boxes (10kg). Meanwhile, for the construction industry, the subjects are demanded to lift a sand bag (10kg). From this study, the optimum values of temperature and humidity can be obtained which can lead to the optimum workers’ performance. The increase of performance will ensure the production level at the manufacturing industries at its best and will lead to monetary gain. Besides, this can ensure that a construction project can be delivered at the right time while reducing the cost lost and the accidents at the site.
A Modified GAN for Compressed Sensing MRI
Authors: Geng Zelong , Tao Jinxu , Xu Jinzhang
Published: September 2020

Magnetic resonance imaging is a commonly used diagnosis method in medicine. Most reconstruction methods are based on the compressed sensing theory, while it is inefficient and time-consuming. In recent years, deep neural networks have developed rapidly. GAN architecture has been widely used in various image tasks after published. This paper proposes a new MRI reconstruction method RISEGAN. The generator uses U-Net structure to extract multi-scale features in the down sampling and up sampling modules. Combined with the residual learning and squeeze excitation blocks, the mapping between the under sampled and the fully sampled image is established. Experiment results show that our method can finish reconstruction with premium quality. Evaluation indicators have also improved.
Dual Channel Attention Networks
Authors: Bian Jingchen , Liu Yugui
Published: September 2020

Channel attention is currently widely used in Computer Vision. Most existing channel attention networks are proposed based on Squeeze-and-Excitation Networks (SE- Net),which can obtain excellent performance by designing complex structures, however, they also has more additional network parameters and higher floating point operations per second (FLOPs). We propose a novel lightweight attention structure called Dual Channel Attention Networks (DCA-Net). By introducing the channel attention preprocessing module and using 1-D convolution with K=1, DCA-Net has a more straightforward and delicate structure. We add DCA-Net to ResNet and perform image classification experiments on CIFAR-100 dataset, object detection and instance segmentation experiments on MS-COCO dataset. Experimental results show that our DCA-Net achieves better results than the existing attention networks, such as SE-Net, ECA-Net and so on. For example, in the image classification task on CIFAR-100, the parameter amount of DCA-Net using ResNet-50 decreases by 50.03 compared to SE-Net using ResNet-101, and decreases by 44.48 compared to ECA-Net using ResNet-101, GFLOPs decreased by 48.41 and 48.21, respectively. At the same time, the Top-1 accuracy of DCA-Net using ResNet-50 is 0.3 higher than that of SE-Net using ResNet-101, and 0.86 higher than that of ECA-Net using ResNet-101.
A Smoothing-Type Algorithm for Solving Monotone Weighted Complementarity Problems
Authors: Jiang Xiaoqin , Huang Yujin
Published: September 2020

The weighted complementarity problem is an extension of the standard finite dimensional complementarity problem. It is well known that the smoothing-type algorithm is a powerful tool of solving the standard complementarity problem. In this paper, we propose a smoothing-type algorithm for solving the weighted complementarity problem with a monotone function, which needs only to solve one linear system of equations and performs one line search at each iteration. We show that the proposed method is globally convergent under the assumption that the problem is solvable. The preliminary numerical results indicate that the proposed method is effective and robust for solving the monotone weighted complementarity problem.
Open-Circuit Fault Diagnosis of Power Rectifier Using Deep Convolutional Neural Network
Authors: Wang Ruoyue
Published: September 2020

Aimed to automatically provide accurate fault diagnosis of data from failed power electronics, various studies have been researched based on different approaches. Recently, data driven methods based on deep learning have required increasing attention because of their automatic feature learning abilities. Nonetheless, one of the challenges using these methods in practice is how to obtain the most representative fault features and ensure the better predication performances at the same time. This paper is in respect of the open-circuit fault diagnosis of the phase-controlled three-phase full-bridge power rectifier using deep convolutional neural network (DCNN) for extracting and further classifying fault features. The process mainly includes four steps. Firstly, a presupposed approach of DCNN which is applied to automatically capture the paramount fault features from the raw data is briefly introduced. Then a structure of DCNN is designed to extract the features from output data. Furthermore, the model and framework of the fault diagnosis system are developed to diagnose the open-circuit fault of the power rectifier. Finally, the effectiveness of the proposed method is validated using simulation results. Experiments illustrate that the DCNN model can achieve high accuracy in different fault cases and present great capability of diagnosing fault types in open-circuit fault of power rectifiers.
Matching Neural Network for Extreme Multi-Label Learning
Authors: Zhao Zhiyun , Li Fengzhi , Zuo Yuan , Wu Junjie
Published: September 2020

Multi-label learning involving hundreds of thousands or even millions of labels is referred to as extreme multi-label learning, in which the labels often follow a power-law distribution with the majority occurring in very few data points as tail labels. As a promising solution of multi-label learning, however, the embedding-based methods face a problem that most of them have the basic low-rank assumption but the widespread of tail labels in data violates it. Recently, research efforts have been put on building tail label tolerant embedding-based models, however, for real-life datasets containing substantial data points with only tail labels, simply treating them as label matrix outliers will incur severe information loss, meanwhile accurately computing the pairwise distances between label vectors turns infeasible. In light of this, we present the Matching Neural Network (MNN), which learns two neural mapping functions that encode feature vectors and label vectors into their distributed representations, respectively. A noise contrastive loss is also proposed to guide the training of the functions so as to ensure matched features and labels have similar distributed representation measured by cosine similarity. Extensive experiments on various benchmark datasets with state-of-the-art baselines demonstrate the more accurate predictions of MNN.