Miracle-dz/UniFAR-FTUs huggingface dataset:
Communication Improvements for Intelligent Systems in Microgrids - Part II

The development of microgrids allows improving the electrical system from renewable energy sources. Costumers have started to install small-scale microgrids formed by wind turbines and photovoltaic panels, to guarantee their energy needs. This paper presents an evaluation of communication performance in small-scale microgrids and vehicle to grid (V2G), based on standard protocol IEC 61850. Three technologies were compared, Ethernet, WiFi and ZigBee according to the costs of implementation, reliability and end-to-end delay. To simulate the behavior of each technology in small-scale microgrids, the Riverbed Modeler software was used. The simulation uses three types of data to evaluate the performance of the network, such as periodic data stream, random data stream and burst data stream, accordingly to the control on intelligent applications. The specific study using these models allowed to reveal the behavior of each technology in front of different data streams and performance of the best technology, according to CPU utilization, data size and application protocol.
A Broadband Circular Polarized Microstrip Antenna Based on Artificial Magnetic Conductor

In this paper, a new octagonal artificial magnetic conductor unit is proposed. The bandwidth of in-phase reflection characteristics is from 8.36GHz to 9.55GHz. Then a circularly polarized microstrip antenna loading a C-shaped slot in the circular microstrip patch with 7×7 artificial magnetic conductor is designed. Simulation results show that the antenna operates in 7.42 GHz~ 10.74 GHz with return loss less than −10dB. And relative bandwidth of the antenna is 36.6%. The frequency range is from 8.30 GHz to 9.37 GHz which axial ratio is less than 3 dB. Gain of the antenna is more than 6dB in the bandwidth.
Performance Analysis of Superdirectivity of Circular Arrays and Implications for Sonar Systems

Superdirective beamforming (SDB) has received a lot of interest recently since by this technique a small circular array, i.e., small <inline-formula><tex-math notation="LaTeX">$ka$</tex-math></inline-formula>, where <inline-formula><tex-math notation="LaTeX">$a$</tex-math></inline-formula> is the radius and <inline-formula><tex-math notation="LaTeX">$k$</tex-math></inline-formula> is the wave number, can achieve small beamwidth, and high directivity factor (DF) as offered by a large circular array using conventional beamforming (CBF). However, the nice features derived theoretically are difficult to achieve in practice since SDB is highly sensitive to signal mismatch, such as errors in array configuration, incorrect signal model, etc. Many methods have been proposed to balance the performance (beamwidth and DF) against the sensitivity. The tradeoff analyses are application and data dependent and computationally intensive. We show in this paper, by deconvolving the CBF beam output using the known beam pattern, that the deconvolved beam output can achieve a narrower beamwidth, higher DF, and lower sidelode level than the SDB, and offers the same robustness as CBF. The performance of the various beamforming methods are quantitatively analyzed and systematically compared in this paper for a wide range of <inline-formula><tex-math notation="LaTeX">$ka$</tex-math></inline-formula> and input signal level. Deconvolution takes negligible processing time and can be applied to existing systems where the beam data are often the only data available.
A Ground Elevation and Vegetation Height Retrieval Algorithm Using Micro-Pulse Photon-Counting Lidar Data

The Ice, Cloud and Land Elevation Satellite-2 (ICESat-2) mission employs a micro-pulse photon-counting LiDAR system for mapping and monitoring the biomass and carbon of terrestrial ecosystems over large areas. In preparation for ICESat-2 data processing and applications, this paper aimed to develop and validate an effective algorithm for better estimating ground elevation and vegetation height from photon-counting LiDAR data. Our new proposed algorithm consists of three key steps. Firstly, the noise photons were filtered out using a noise removal algorithm based on localized statistical analysis. Secondly, we classified the signal photons into canopy photons and ground photons by conducting a series of operations, including elevation frequency histogram building, empirical mode decomposition (EMD), and progressive densification. At the same time, we also identified the top of canopy (TOC) photons from canopy photons by percentile statistics method. Thereafter, the ground and TOC surfaces were generated from ground photons and TOC photons by cubic spline interpolation, respectively. Finally, the ground elevation and vegetation height were estimated by retrieved ground and TOC surfaces. The results indicate that the noise removal algorithm is effective in identifying background noise and preserving signal photons. The retrieved ground elevation is more accurate than the retrieved vegetation height, and the results of nighttime data are better than those of the corresponding daytime data. Specifically, the root-mean-square error (RMSE) values of ground elevation estimates range from 2.25 to 6.45 m for daytime data and 2.03 to 6.03 m for nighttime data. The RMSE values of vegetation height estimates range from 4.63 to 8.92 m for daytime data and 4.55 to 8.65 m for nighttime data. Our algorithm performs better than the previous algorithms in estimating ground elevation and vegetation height due to lower RMSE values. Additionally, the results also illuminate that the photon classification algorithm effectively reduces the negative effects of slope and vegetation coverage. Overall, our paper provides an effective solution for estimating ground elevation and vegetation height from micro-pulse photon-counting LiDAR data.
Time-varying metamaterial Doppler cloak: applications to invisibility and antennas

Doppler cloak is a cover to be placed in front or wrapped around a moving object to restore the source illumination frequency, as if it were not in motion, bringing the object to operate again in the standard static conditions. This feature is useful in narrowband applications, such as invisibility cloaks and highly resonant antennas, where a small detuning from the design operation frequency is sufficient for losing the invisibility effect or the communication link, respectively. Here, we show some results on the application of Doppler cloaks in these two scenarios. First, we consider the simple case of a cloaked cylindrical metallic scatterer in motion and, then, an antenna system composed of two antennas that are moving with respect to each other. Our preliminary results show that the Doppler cloak can shift the band of the propagating signal within the operative band of the cloak and of the receiving antenna, restoring the operative conditions for both cases.
Simple and Broadband Transition Between Rectangular Waveguide and Groove Gap Waveguide for MM-Wave Applications

A vertical wide band transition between a standard WR-15 rectangular waveguide (RW) and groove gap waveguide (GGW) in the V-band is presented. A simple step is applied to achieve a good impedance matching in transition between the RW and the GGW. A back-to-back transition is designed and fabricated to verify the simulation results. The measured results of the fabricated prototype show the insertion loss of less than 0.2 dB and the input reflection coefficient better than −16 dB over almost the whole V-band (50–75 GHz).
A Novel L-CRLH Based Compact Wide Band Filtered Power Divider for WLAN Applications

A new compact power divider based on inductor loaded composite right/left-handed transmission line (L-CRLH) is presented in this paper. The proposed power divider size is only 17.3 × 15.4 mm2, (0.53×0.47) λ2 g at mid frequency. The results show 3 dB insertion losses and 14 dB return losses at each output port in the frequency band 5 GHz to 6.5 GHz. Moreover, the power divider has filtering function
SIW Structure Explored as a Low-Profile Wideband Antenna bearing User-Friendly Characteristics for Wireless Transceivers

A compact low profile wideband antenna is developed and discussed. Its basic structure is derived from the circular cavity following the repetitive segmentation along the quasi-magnetic wall to obtain the 16th mode geometry. Periodic slots have been etched out alternatively from the top metallic surface, the thickness of which has been engineered to obtain wideband operation from the antenna. The ground plane has been modified for achieving an user-friendly radiation characteristics.
Investigation on Balanced Double-Sided Gap Waveguide for W-Band Applications

In this paper, a double-sided gap waveguide (DSGWG) working at W-band has been proposed. For the conventional double-sided parallel strip line (DSPSL), its performance is deteriorated by the losses at W -band. Based on the newly proposed half-height pins structure, the DSGWG has been investigated. For this new DSGWG, there is no dielectric loss compared to DSPSL since waves propagate in the air-filled gap. In addition, the spurious radiation has been suppressed by the half height pins. This DSGWG has achieved the good transmission performance at W -band. The characteristics impedance of offset DSGWG has been investigated. It shows that the offset DSGWG can realize a relatively high impedance without change the line width. Furthermore, the DSGWG with an inserted conductor plane is researched as well. The inserted conductor can function as a virtual ground (GND) to isolate different circuits on the top and bottom layers. Based on those characteristics, some results based on offset structure and dual band structure have been given to verify the DSGWG's performance.
Tunable Deep-Red Electroluminescence From Flexible Quasi-2D Perovskites Light-Emitting Diodes

In this letter, we synthesize and characterize a new series of organic/inorganic hybrid quasi-2D perovskites PEA <sub>2</sub>(FA)<sub>n–1</sub>Pb<sub>n</sub>I<sub>3n+1</sub> (<inline-formula> <tex-math notation="LaTeX">$n = 2, 3, 5$ </tex-math></inline-formula>). The quantum well thickness of perovskites could be adjusted by regulating the crystal structure, which resulted in a tunable bandgap and emission spectra. The deep-red emissions from the flexible light-emitting diodes have been successfully achieved. The optimal device presents a maximum luminance of 212 cd/m<sup>2</sup>, a maximum current efficiency of 0.44 cd/A, and a maximum external quantum efficiency of 0.148% with an electroluminescent spectrum peak of 720 nm and the corresponding CIE coordinates of (0.691, 0.291).
Design of Frequency Selective Paper for Crack Detection of Concrete Building Structure

In this paper, a frequency selective paper with X-band reflection characteristics is designed for the crack detection of concrete building structures and the change of resonant frequency characteristics according to cracks are investigated. Based on the crossed dipole unit cell known to have narrow-band reflection characteristics, a frequency selective paper operating in the X-band was designed and the frequency characteristics of the frequency selective paper unit structure including cracks were observed. As the crack width increased by 0.2mm, the resonance frequency tended to move to the higher band by about 90MHz. It was confirmed through simulation that the existence and the width of the crack can be predicted. Designed frequency selective paper was fabricated and frequency reflection characteristics were measured for six types of cracks. From the measurement result, the existence of cracks and the shape of cracks can be predicted according to the polarization of the incident angle.
Mutual Coupling Reduction Between Two Closely Spaced PIFAs

This paper presents the design of two PIFAs antennas array with decoupling structure to enhance the isolation between the elements for MIMO applications. The array is built on flexible polyimide substrate with relative permittivity of 4.3 and thickness of 50 um. The decoupling structure is rectangular loop placed between the two PIFAs. The array resonant at 2.45 GHz. An isolation of 7 dB has been achieved between the two elements at 2.45 GHz with separation of 2 mm. The total realized gain of the two elements excited in the array has been increased to 1.4 dB. The array is suitable for MIMO applications where compact size and high isolation between elements are required.
A Polarization-Agile Stub-Loaded Square Patch Antenna with Proximity Coupled Feed

A novel design of a polarization-agile microstrip-line-coupled-fed patch antenna is proposed. The simple structure of the proposed antenna consists of a square patch symmetrically loaded with two PIN -diode connected short-circuited stubs, and the use of proximity-coupled feed allows inherent impedance matching and RF and DC signal isolation without the need of DC blocking components. The fabricated 1.6-GHz prototype of our proposed antenna, when biased with different DC voltages, can achieve linear and right- and left-handed circular polarizations, respectively.
Journal of Field Robotics special issue on MBZIRC 2017 Challenges in Autonomous Field Robotics

Robotics has the potential to have an impact that is as transformative as the Internet, with robotics technology poised to fuel a broad range of next‐generation products and applications in a diverse array of fields. These include robot applications in disaster response, manufacturing, construction, healthcare, and household chores. In the past few decades, robot competitions have been a catalyst for accelerating technological advancements in robotics and autonomous systems. The Mohamed Bin Zayed International Robotics Challenge (MBZIRC) is a biennial robotic competition motivated by some of the technological challenges faced by the next generation of robots. The enabling technologies for next‐generation robot applications include robots working more autonomously in dynamic, unstructured environments, while collaborating and interacting with other robots and humans. MBZIRC 2017 focused on some of these enabling technologies, by providing a demanding set of robotics benchmarks, and has attracted some of the best international research groups. Similar to other major competitions, MBZIRC provided an environment to foster innovation and technical excellence, while encouraging entertaining performance. Simultaneously, as usual in scientific robot competitions, the different approaches to the same challenge were tested under very demanding and realistic scenarios, where experimental conditions are not controlled as in a research laboratory, and are compared regarding their performance when facing the same challenge. This special issue provides a collection of papers describing original approaches developed to solve the MBZIRC 2017 Challenges. Those three Challenges consisted of
Research on the Construction of the Attractiveness of Universities WeChat Public Accounts — Taking Communist Youth League Public Platform of Guangxi University as an Example

With the wide usage of the WeChat public platforms, universities have also established their own WeChat public platform to provide information services to teachers and students. The WeChat public account has become a new form of campus media. This study takes the WeChat public platform of Guangxi University Communist Youth League (XDTXXW) as an Example to find the main affecting factors of increasing users of campus WeChat public account and its influence mechanism. Study finds that entertainment and the usefulness of the service are the main factors that increase users to the campus media. Suggestions for the operation of WeChat public account in universities are put forward.
OligoArchive: Using DNA in the DBMS storage hierarchy

The demand for data-driven decision making coupled with need to retain data to meet regulatory compliance requirements has resulted in a rapid increase in the amount of archival data stored by enterprises. As data generation rate far outpaces the rate of improvement in storage density of media like HDD and tape, researchers have started investigating new architectures and media types that can store such “cold”, infrequently accessed data at very low cost. Synthetic DNA is one such storage media that has received some attention recently due to its high density and durability. In this paper, we investigate the problem of integrating DNA in the database storage hierarchy. More speciﬁcally, we ask the following two questions: (i) how can database knowledge help optimize DNA encoding and decoding? and (ii) how can biochemical mechanisms used for DNA manipulation be used to perform in-vitro, near-data SQL query processing? In answering these questions, we present OligoArchive , an architecture for using DNA-based storage system as the archival tier of a relational database. We demonstrate that OligoArchive can be realized in practice by building archiving and recovery tools (pg_oligo_dump and pg_oligo_restore) for PostgreSQL that perform schema-aware encoding and decoding of relational data on DNA, and using these tools to archive a 12KB TPC-H database to DNA, perform in-vitro computation, and restore it back again.
A High-Gain Dual-Frequency Dual-Polarization Feed System for 5G Communication

A design of a high-gain dual-frequency dual-polarization feed system for 5G communication is presented. The feed system operating at 28 GHz and 60 GHz is composed of a dual-band coaxial horn, a coaxial orthomode transducer (Coaxial OMT) for 28 GHz, and an orthomode transducer (OMT) for 60GHz. The simulation results show that the reflection coefficient is less than -10 dB in the frequency range of 27.7-28.3 GHz and 59–61 GHz. Simulated gains at 28GHz and 60GHz are both 17dB and the radiation patterns are basically rotationally symmetrical. Besides, the feed system possesses a near constant phase center over the high and low frequencies. The proposed feed system can be used to illuminate the reflector antenna or reflectarray.
A Flexible 202-Channel Epidural ECoG Array With PEDOT: PSS Coated Electrodes for Chronic Recording of the Visual Cortex

Electrocorticography (ECoG) electrode arrays for epidural implantation allow establishing neural interfaces, which promote investigation of complex distributed brain functions and development of neuroprosthetic systems while having reduced invasiveness in comparison to intracortical or subdural electrode placement. In this paper, we present the design, fabrication, and both <italic>in-vitro</italic> and <italic>in-vivo</italic> evaluation of a flexible ECoG array with 202 closely spaced electrodes of 560-<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> diameter, each coated with the polymer poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT: PSS) for chronic recording in two visual cortical areas V1 and V4 of macaque monkeys. The specific layout of the array provides a close fit to the curved surface of the brain. We confirm its chronic recording functionality <italic>in-vivo</italic> by estimating visual receptive fields for the individual electrodes.
Joint Opportunistic Routing and Intra-Flow Network Coding in Multi-Hop Wireless Networks: A Survey

Opportunistic routing and network coding are two promising techniques that have been proposed for wireless networks. These techniques have significantly improved the performance of multi-hop wireless networks by utilizing the broadcast nature of wireless media and optimizing the capacity of lossy wireless networks. Recent research has shown that the combination of opportunistic routing and network coding in a single joint protocol outperforms each of them individually. This article explains the motivation and interaction effect of the joint protocols. We provide a taxonomy of joint protocols and illustrate the benefit and cost by highlighting their fundamental components and comparing different solutions. We also present a conclusion along with the outline of future research direction.
Low-Voltage, Flexible InGaZnO Thin-Film Transistors Gated With Solution-Processed, Ultra-Thin AlxOy

Indium–gallium–zinc-oxide thin-film transistors gated with solution-processed, ultra-thin AlxOy have been fabricated on a plastic substrate. The effects of bending on the gate dielectric in terms of leakage current density and capacitance density have been studied. The devices show a low operating voltage of less than 1 V, a high current on/off ratio >105, and a low subthreshold swing <90 mV/decade. The devices maintain their high performance even when flexed to a curvature radius of 11 mm. As a result, such devices possess a great potential for low-power, flexible electronics.
A Compact Dual-Band Antenna Based on SIW Technology

In this paper. , a compact dual-band antenna based on substrate-integrated waveguide (SIW) technology is proposed. The antenna is comprised by three layers. The top layer is a SIW cavity-backed slot antenna while the middle layer is a quarter-mode SIW (QMSIW) antenna. A microstrip feeding line is configured on the bottom layer connecting to a vertically-oriented probe penetrating through the three layers to feed the antenna. Full-wave simulations show that two operational bands with unidirectional radiation along broadside direction are successfully achieved at 2.6 and 5.9 GHz. The fractional bandwidths are equal to 1.54% and 2.71 %. , respectively. The overall size of the antenna is 33mm×43mm×5. 23mm, which is extremely compact. Moreover. , parametric studies revealed that the two bands can be tuned separately by adjusting the appropriate design parameters.
Détection des nanoparticules manufacturées sur les places de travail

Depuis plusieurs annees, la production et l'utilisation de nanoparticules manufacturees a l'echelle industrielle sont en plein essor. A l'echelle nanometrique, les materiaux developpent des proprietes physico-chimiques nouvelles, tres utiles dans de nombreux secteurs industriels (pharmacie, electronique, materiaux .). Cet engouement industriel souleve quelques interrogations relatives a la securite sur les lieux de travail. En effet, si les proprietes physico-chimiques de tels objets sont accrues, il en est de meme concernant leur toxicite [1] et leur capacite a s'enflammer [2]. Ainsi, les risques sanitaires et accidentels potentiels lies a la manipulation des nanoparticules manufacturees (production, transport, stockage) sur les places de travail representent un sujet d'actualite faisant echo jusque dans la sphere publique [3]. Bien que les procedes de fabrication soient de plus en plus surs, les risques d'emission lies a des fuites, des mises en suspension accidentelles ou encore a la manipulation de poudres manufacturees sont mal connus. Cette lacune s'explique notamment par le fait qu'il est difficile d'effectuer des mesures des concentrations de nanoparticules manufacturees en ambiance de travail
A Broadband RHCP/LHCP SIW-Integrated Patch Array Antenna for MM-Wave Applications

Right-hand (RH)/ left-hand (LH) circularly polarized (CP) antenna, made of two integrated linear polarized (LP) microstrip patch antennas (MPA) fed by substrate integrated waveguide (SIW), is presented. The antenna uses a 3dB SIW quadrature hybrid coupler to generate right/left hand CP radiated field from two LP antennas with two excitation ports. The structure was designed and simulated. Simulation results reveal that the antennas show 3dB axial-ratio (AR) bandwidth over the frequency band ~51.15-68.5 GHz.