Miracle-dz/UniFAR-FTUs huggingface dataset:
Accurate and Efficient Multi-robot Collaborative Stereo SLAM for Mars Exploration

In recent years, planetary exploration has received a lot of attention in the aerospace field, and Mars is favored because of its cosmic environment that is very similar to the Earth. So far, human have sent six rovers and a helicopter to Mars. However, the GNSS global navigation system is unavailable on Mars, and there is a communication delay of 7 to 45 minutes between the Earth and Mars, which poses a huge challenge to the autonomous navigation and obstacle avoidance of the Mars robot. At the same time, the current exploration is carried out by a single robot, so the exploration range is limited. Multi-robot collaboration can improve the efficiency and robustness of planetary task execution. Multi-robot collaborative Simultaneous Localization and Mapping (SLAM) is conducive to enhancing the localization and mapping capabilities of robots. To achieve the goal, we propose an accurate and efficient Multi-robot collaborative stereo SLAM(MCS-SLAM). While ensuring that each robot works independently, MCS-SLAM collects the robot's localization and mapping results to the server through wireless communication, and completes the fusion optimization of multi-robot's localization and mapping data on the server. We generated six sets of image data, which were respectively captured by the stereo cameras carried by the simulated three rovers and three UAVs. Considering the limited CPU performance of Mars robot's computing device, we conducted experiments on Nvidia's edge computing equipment. The experimental results show that MCS-SLAM achieves real-time localization effects of 6fps and 10fps on Jeston TX2 and Jeston Xavier. Overall, when only stereo cameras are configured for collaborative work, the localization accuracy of the rover team and the UAV team reached 1.97m and 0.89m, respectively, and the average localization accuracy of 100 meters was 0.36m and 0.17m.
Creating Sharp Nulls at Broadside using a 2-D Leaky-Wave Antenna with a Vertical Dipole Source

A two-dimensional leaky-wave antenna (2-D LWA) is one that uses a cylindrically propagating leaky wave to form a narrow beam, which is usually a pencil beam at broadside when a horizontal dipole source is used. When excited with a vertical dipole source, however, a null at broadside is instead produced, which might be beneficial for some applications. This peculiar feature is scarcely investigated in the literature and a preliminary analysis is here reported. Relations between the half-power beamwidth and the half-power nullwidth of the beams radiated by 2-D LWAs are found and demonstrated through numerical results.
A 2×2 paralleling GaN half-bridge power module for high-density 500kHz 3.3kW CLLC converter

A 2×2 paralleling GaN half-bridge power module is developed, where four GaN dies are encapsulated with minimizing parasitic inductances. It is suitable for high-power, highly efficient and high-density power converters under high frequency operation. It is confirmed that the module board has small parasitic components by electromagnetic field simulation. In this paper, we demonstrate a 3.3 kW CLLC converter which is operated at the switching frequency of around 500 kHz employing the developed 2×2 paralleling GaN half-bridge power module. The power density and the peak efficiency of the CLLC board are 8.8 W/cm3 and 97.1 % respectively, which correspond to 25 % and 0.3 % improvement compared with the case in which four discrete GaN power transistors are employed, respectively. The obtained improvements are attributable to the smaller parasitic inductances of the developed GaN module.
Electromechanical-electromagnetic Transient Hybrid Simulation Research on AC Fault Ride-through Characteristics at Receiving-end of LCC-VSC Hybrid Cascaded DC System

Line commutated converter-voltage source converter (LCC-VSC) hybrid cascaded DC system combines the advantages of LCC and VSC. The topology structure that the rectified side adopts LCC, and the inverse side adopts LCC connected by VSC groups shows the advantages of large-capacity power transmission. Based on advanced digital power system simulator (ADPSS), the electromechanical-electromagnetic transient hybrid simulation model of large power grid containing LCC-VSC hybrid cascaded DC is set up, and the research on characteristics of AC fault ride-through at receiving-end is carried out, which takes into account simulation accuracy and scale. The results show that compared with the electromagnetic transient simulation using equivalent network, the hybrid simulation can more accurately simulate the voltage drop and recovery characteristics of AC system, and verify the necessity of using this simulation method. The research of ride-through characteristics needs to focus on the scene where only two VSCs are in operation at either of the two poles and comprehensively consider the faults in the nearby areas around DC drop point. The spinning reserve proportion and inductive motor proportion in load in the nearby areas around DC drop point are strongly related to the recovery characteristics of AC voltage, which are two important factors affecting the ride-through characteristics of AC fault at receiving-end.
Low-Profile UWB Probe For Precise Time-Domain Functional Imaging

In this paper a Double Ridge Waveguide (DRW) antenna fed by a microstrip line covering a frequency band from 0.5GHz to 2.5GHz is designed, fabricated, and measured, for functional microwave imaging. The proposed DRW antenna is used as the probe element in a collateral multi-static system to detect a cylindrical target located inside a human brain liquid medium. Also an approach for the spatial reconstruction accuracy based on maximum time resolution is presented. Measured and simulated results are conducted and discussed.
Numerical Study on Osmotic Equilibrium Timeliness of Oil-Gas Separation Membrane in Online Monitoring System of Transformer Oil Chromatogram

Oil-gas separation is an important part of dissolved gas analysis technology for monitoring transformer status. Compared with the traditional vacuum pump degassing method and solution equilibrium method, the membrane separation method is simple in structure, does not produce waste oil, and can be used for continuous separation. It has become one of the hot spots in the analysis of dissolved gases in oil. Poor timeliness is the main bottleneck of the application of polymer membrane separation technology. This paper first analyzes the mechanism of oil-gas separation by polymer permeable membrane. Then, the key factors affecting the timeliness of oil-gas separation are studied through calculation and simulation. Finally, according to the conclusions of this paper, we summarize some rules and reasonable opinions for improving the timeliness of oil-gas Separation.
Measurement-based Analysis of Multi-band Assisted Beam-forming at mmWave in Industrial Scenarios

The mmWave and sub-THz bands are foreseen as candidates to achieve the data-rate demands in the beyond 5G and 6G wireless communication networks. The co-existence of multiple radio interfaces at several bands enables data fusion and the utilization of the similarities and differences on propagation and system properties for communication and sensing applications. MmWave radio interfaces rely on directive beams that require high training overhead for beam steering. Sensors in the network infrastructure and co-located radio interfaces at sub-6 GHz and mmWave can be used to assist the beam-forming process at mmWave. In the present paper we investigate the performance of multi-band assisted beam-forming in an industrial environment. We empirically demonstrate from real-world measurements that even in NLOS, the direction of the beams estimated at sub-6 GHz can be used to established a link at mmWave.
Achievability Approximation of IDS Hub Using Collaborative Network Model With ML

Intrusion detection systems (IDSs) have been generally sent in PCs and organizations to recognize a variety of attacks. Yet, network intrusions are presently turning out to be more modern to distinguish, accordingly collaborative intrusion detection networks (CIDNs) have been proposed which empower an IDS to gather data and take in experience from different IDS hubs. By keeping up with associations among a bunch of IDS hubs, a CIDN is relied upon to be all the more remarkable in recognizing some muddled assaults like denial-of-service (DoS) than a solitary IDS. In genuine organization, we distinguish that every IDS might have various degrees of affectability in recognizing various sorts of interruptions (i.e., because of their marks and settings). In this paper, we along with these lines characterize a thought of interruption affectability and examine the achievability of utilizing it to assess the reliability of an IDS hub. What’s more, we describe a few difficulties when utilizing this idea in practice.
Impact of the Asymmetric Signal Routing on the Wideband Spatial Behavior of Large Modular Phased Arrays

Phased arrays have typically equal lengths for all antenna paths. This paper compares three phased array architectures for 5/6G applications. The first two arrays present unequal-length feeding networks, while the third array is the corporate-fed one. The first array is fed from the center, while the second is fed from the side. The impacts of the unsymmetrical feeding network on the bandwidths are analyzed and compared to the corporate-fed array. We show that side-fed arrays present higher bandwidths for higher steering angles, while center-fed arrays work better in the broadside region. Moreover, side-fed arrays can also be better than corporate-fed ones near the end-fire region, making them a good alternative to reduce the footprint of the feeding networks. Finally, we illustrate that if the feeding point can be varied as a function of the desired steering angle, the broadband performance of the array can be optimized for different steering angles.
A uniplanar low-sidelobe periodic leaky-wave antenna based on a metamaterial-inspired substrate integrated waveguide

We analyze and design a uniplanar and low-sidelobe periodic leaky-wave antenna (PLWA), suitable for millimeter- wave 5G applications. The antenna is synthesized by etching a non-uniform pattern of transverse slots on the top plane of a metamaterial-inspired substrate integrated waveguide (SIW). Uniplanar complementary split-ring resonators (CSRRs) sub- stitute the conventional metalized via holes, to construct the CSRR SIW. The CSRR SIW is uniplanar and presents a low- loss, low-cost and easy-to-fabricate alternative for millimeter- wave communications. The proposed CSRR-SIW-based PLWA features low sidelobes, high gain and a beam-scanning ability. The antenna performance is similar to PLWAs implemented using the conventional SIW. The proposed design is also accompanied by a considerably simpler fabrication process, hence rendering the CSRR-SIW PLWA an appealing choice for 5G applications.
An Ultra-high Gain Current-fed Universal Auxiliary Power Module for 400V/800V Electric Vehicles

As the counterparts of alternators, the auxiliary power modules (APM) in electric vehicles (EVs) play an irreplaceable role in bridging the high-voltage (HV) propulsion system and low-voltage (LV) auxiliary system. With the increasing demands on fast charging, the HV propulsion system is seeing an involution from 400 V system to 800 V system. To adapt to the trends, the APM also faces the challenge of accepting a wider input voltage range, particularly in EVs with a reconfigurable battery pack. This paper proposed a reconfigurable current-fed dual active bridges (CFDAB) based converter which accepts an ultra-wide-range input from 180V to 900V and an output from 6V to 16V to cover both 400 V and 800 V systems. Topology, operation principles, and simple control to minimize the switching loss are discussed in the paper. A >3 kW prototype with a peak efficiency of 97% was built and tested, which successfully validated the proposed topology and control.
On Small Antennas with Circular Polarization, Bandwidth Estimates and Design Considerations

Circular polarization is an essential feature for small antennas designed to connect with satellite navigation systems. Here, a Q-factor optimization problem constrained with a circular polarization radiation requirement is formulated and solved. The constrained problem is shown to be solvable as fast as calculating the Q-factor bound without the constraint. Two antenna models are designed to assess the bounds. One aims for bandwidth, and the other for circular polarisation. The well-known relation between the Q-factor and the available bandwidth is used to evaluate the designs. The circularly polarised antenna is close to the bound and has a wide field of view. The Q-factor bound provides insight into desirable antenna positions on the small device.
SbD-Driven Microwave Imaging for Biomedical Diagnosis

Microwave Imaging (MI) provides a low-cost and safe approach to the non-invasive diagnosis of biological structures. However, solving the associated Inverse Scattering Problem (ISP) in a timely manner poses several challenges. To jointly achieve high reconstruction accuracy and low computation time, an imaging strategy based on the System-by-Design (SbD) paradigm is presented. The proposed SbD approach can deal with ISPs with an inhomogeneous background and is capable of exploiting a-priori information on the electromagnetic (EM) characteristics of the biological structure under investigation. Preliminary results based on a realistic brain phantom show that a remarkable reconstruction accuracy is achieved together with a significant reduction in terms of computation times as compared to competitive state-of-the-art approaches.
Spectral Floquet-spatial modulations devoted to strongly coupled periodic arrays: metasurfaces, dense massive MIMO, reconfigurable-intelligent-surfaces (RIS), 5G and 6G uses

In this paper, we propose a spectral modulation technique with its spatial equivalent to studying the coupled largely finite and infinite periodic arrays, useful for 5G and 6G applications (e.g., reconfigurable smart surfaces for 6G systems). Several forms of spectral and spatial modulations are presented. The sum of these modulations based on their large spatial periods allows the estimation of the total large array response (and to control their beam orientation in any desired direction) in the presence of a large number of elements (e.g., dense massive MIMO). The decomposition into sub-arrays where each of them has its own modulation character is demonstrated based on the Floquet analysis (steering the beam of each modulation zone independently of the other neighboring zones is possible in the same panel structure). Various numerical methods use these modulation properties in their kernels, including the MoMGEC.
Renumbering strategies based on multilevel techniques combined with ILU decompositions

In this paper, we present an incomplete-factorization technique that uses a renumbering of the unknowns, based on a sequence of grids as in an multigrid. For many problems discretized on structured grids e obtain almost grid-independent convergence when this factorization is combined with a certain conjugate gradient-like method. Also, a similar preconditioning technique is described, which can he used for matrices with arbitrary sparsity patterns, as those arising from finite-element methods on unstructured grids. During factorization, we use a reordering to guarantee that the diagonal blocks to be inverted remain strongly diagonally dominant. This makes it possible to approximate the needed inverses by only a diagonal matrix, leading to more potential parallelism. The method is demonstrated for a number of test problems and compared with some standard methods.
Higher Spatial Harmonic Leaky Wave Antenna Design Based on Meandering Microstrips

A Leaky Wave Antenna (LWA) design with high scanning rate (the ratio of beam scanning range and bandwidth) is proposed in this work. The antenna is based on a periodic meandering microstrip line operating in K-Band with continuous beam scanning from backward-to-forward direction in the elevation plane. The height of the transverse lines is varied periodically in the unit cell to increase the electrical length. Hence, the antenna operates in higher spatial order which increases the scanning rate. The final antenna shows a scanning range in the elevation plane from −40° to 45° in the frequency range from 20.6 GHz to 24.6 GHz corresponding to a scanning rate of 21.25 ° GHz−1. The antenna performance is compared with conventional meandering leaky wave antenna design to demonstrate notable increase in the scanning rate with very less impact on gain while also maintaining low profile.
Networking Technology of Plug-and-Play Multi-DT in Distribution IoT

The distribution Internet of Things (IoT) has realized the integration of heterogeneous devices and heterogeneous information. However, due to the difficult operation and maintenance by the diverse equipment, the existing research on the networking technology of multiple distribution terminals (DT) is less involved in optimizing the communication technology to improve the economy and communication reliability of networking. And the plug-and-play technology of distribution IoT equipment can effectively solve the engineering problems such as complex types of distribution equipment, long installation time, and large maintenance workload. It has broad application prospects. Therefore, this paper proposes a plug-and-play multi-DT networking technology for distribution IoT. Firstly, a multi-DT networking architecture based on IEC61850 standard is proposed; A multi-dimensional evaluation model and optimization technology are proposed to deal with the communication protocol difference of mass devices; Based on the above technical support, the multi-DT automatic networking technology of the distribution network of things is constructed. Finally, taking the 35kV distribution network in the Taishan District, Tai'an, China, as an example, the proposed method is verified to prove its effectiveness, to provide reference for the construction of the distribution IoT.
Submillimeter wavelength radiometry dedicated to spectral analysis of planetary atmospheres: Low noise system development at Paris Observatory

We address the development of low noise system radiometer for heterodyne detection at Terahertz frequencies for high spectral resolution instruments (typ. 107) at Observatoire de Paris PSL. This work highlights constant effort to aim at keeping state-of-the-art receiver noise performances from 300 GHz to 1200 GHz and above for molecular line and continuum detection. In this work we concentrate on the mixer element as the first active element of the radiometric chain. We present the current ongoing work for the demonstration of a low-noise 325 GHz radiometer for earth atmospheric sounding applications. Three types of mixer configurations have been optimized and some of them fabricated and measured. We discuss some, but not all, of the system related aspect and the choice of mixer parameters for best performance that will provide stability for the long-term operation.
The Smart EM Environment Paradigm - From the Idea Towards the Implementation

The Smart ElectroMagnetic Environment (SEME) is a revolutionary paradigm that is expected to become a fundamental pillar in the design of next generation wireless communication systems. It is based on the disruptive idea that the environment should be regarded, differently from the past, as an additional degree-of-freedom (DoF) to improve the overall Quality-of-Service (QoS), rather than an uncontrollable obstacle to the propagation of electromagnetic (EM) waves. This work summarizes the basic concepts and ideas on which the SEME is founded, surveying some of its most recent implementations and envisaging some future trends in this emerging research area, as well.
Contrast Study of Sub-pixel Edge Detection Based on Moment

The moment- based sub- pixel edge detection is one of the most available and mature algorithm. In this paper, the three methods based on moment will be analyzed, and gray moment will be improved because of the limitation in judging edge. At last the contrast study of three methods will be presented. All these works are propitious to the selection of methods in practice.
Price-taker Bidding and Pricing Strategy Using Deep Deterministic Policy Gradient Algorithm with Transformer Neural Networks

The joint strategy optimization problem of a load serving entity (LSE) in both wholesale electricity market (WEM) and retail electricity market (REM) is converted into an aggregated load prediction problem and a sequential decision optimization problem, under the condition of "price-taker". By formulating the original retail price optimizing problem as a Markov decision process (MDP), a novel deep deterministic policy gradient (DDPG) algorithm combining with a transformer based representation network (DDPG-TSFR) is proposed to solve this MDP. A new network structure is designed for the proposed DDPG-TSFR by using multiple loss functions, and a method based on gradient normalization (GradNorm) is adopted to realize adaptive loss weighting factors. We conduct several numerical experiments to compare the training and computational behaviors of the proposed DDPG-TSFR with different DRL based approaches. Numerical results validate the effectiveness and superiority of the proposed approach.
Analysis and Synthesis of Phased Antenna Arrays through Quantum Computing

The analysis and synthesis of phased array (PA) antennas are addressed and reformulated in a Quantum Computing (QC) framework by adopting the Quantum Fourier Transform (QFT) to perform fundamental calculations as an alternative to the classical discrete Fourier transform (DFT). Numerical results obtained by simulation of quantum devices are also presented to support the proposed methodology.
The Power Optimization of mm Wave Circular Array Antenna for 5G Communications

5G network requires large link capacity and minimal latency. mm wave technology i.e., waves having very short wavelength is widely used in 5G. These high frequency signals suffer from attenuation as signals tend to travel along the surface of traces. Signal attenuation can be mitigated by increasing the gain of the antenna. The project propounds the design implementation of a $4\times 4$ circular patch array antenna tuned at a frequency range of 24.35 to 28.5GHz which is the ideal range for mm wave. Usage of this antenna helps to reduce interference and improves signal quality. The designed antenna resulted a return loss and is observed to be −22 dB making it ideal for real time applications.
IoT-based Transceiver Antenna System for 5G Future High-Speed Train Communications

The serious problems with rail radio systems across the world mainly originated from poor train antenna design and deployment. Hence designing antennas for reliable radio access is so essential in public advanced railway systems. On the other hand, the mm-wave frequency spectrums are recognized sources of valuable frequencies to supply the high-rate 5G and beyond 5G Internet services with a speed of over than 10 GB per second. In this article, an mm-wave 5G transceiver antenna which includes a tapered-slot antenna and an EM signal distribution network has been introduced to overcome the challenges of harmful interaction between the transmitting and receiving high-speed train antennas and reduce their technical conflicts in the installation.