Miracle-dz/UniFAR-FTUs huggingface dataset:
Constraints-Aware Trajectory Tracking Control of Spacecraft Attitude using LPV and MPC

This paper presents an approach for trajectory tracking of quaternions representing spacecrafts attitude. A nonlinear controller is applied to a time-varying error system to track realizable trajectories of quaternions. The resulting closed loop is linearized leading to a linear parameter varying system (LPV), which is then used to analyze the closed loop and parameterize the nonlinear controller. Additionally, an outer-loop controller is applied to achieve objectives beyond closed-loop stability. Results demonstrate the effectiveness of the overall controller with two different linear controllers, LQR and MPC, for improving attitude control performance and input constraint satisfaction, respectively.
A Compact Polarization Insensitive Triple-band Artificial Magnetic Conductor using Complementary Structures

This paper presents the design of a compact triple-band artificial magnetic conductor using stacking of the complementary structure. The proposed triple-band complementary AMC is formed by combining the cross-shaped structure with three stubs of different lengths at each arm on one dielectric slab and its complementary geometry on the other dielectric slab. The proposed AMC provides the three 0° degree reflection phase frequencies at 2.45 GHz, 3.5 GHz, and 5.99 GHz with a ±90° reflection phase bandwidth of 0.2 GHz, 0.17 GHz, and 0.94 GHz, respectively. The unit cell size is 13 mm×13 mm (0.1λ0×0.1λ0), where λ0 is the wavelength at the lowest resonance frequency of 2.45 GHz. The proposed structure is insensitive to incident polarization and angles due to the four-fold symmetry of the unit cell. In addition, on rotating the complementary structure, the AMC unit cell exhibits the two closely spaced reflection phase frequencies.
Design and Optimization of Compact multi band Metamaterial antenna using Machine Learning Algorithm

In this article compact multi band meta material antenna by using split ring resonator concept is present and thoughtful attempt is made to introduce machine learning optimization for the designed antenna. The designed (10 X 10) mm compact multiband metamaterial antenna on FR-4 substrate (ɛr =4.4) using line feeding is working at 14.42GHz, 18.92GHz & 25.22GHz frequencies with operating bandwidth of 1820MHz, 340MHz & 960MHz and VSWR of 0.17dB, 2.82dB & 0.48dB, S11 of -40.04dB, -15.91dB -31.17dB respectively. Split ring resonator concept is used for the basic design in high frequency structural simulator for the multi band antenna design. The Machine Learning (ML) approach for the optimization of antenna is discussed at length. The output error and standard deviation for the standard ML model is discussed. The proposed antenna has potential applications at 5G frequencies with multiple band operation for GSM, high data rate transmission, body area networks and Tera hertz applications.
Multi-hop Wireless Transmission for Maritime Scenarios

The collection and processing of maritime information is an essential task that demands extensive analysis to achieve a more profound understanding of coastal regions. Usually, data is gathered through sensors placed on buoys and transmitted to onshore data centres for storage and examination. Nevertheless, the harsh marine environment, including waves, wind, and vessel traffic, creates substantial challenges for effectively managing this task. This paper focuses on two key objectives: firstly, introducing a physical model for electromagnetic propagation in a buoy network that takes into account the unique characteristics of the marine environment, and secondly, evaluating the performance of the physical model in a multi-hop data transmission scenario using a LoRaWAN mesh network. The main aim of the proposed approach is to facilitate efficient communication while optimising the utilisation of reconfigurable devices to reduce power consumption and accelerate data transmission. To gauge the effectiveness of the proposed solution, we explored a multi-hop approach centred on a single relay node that receives packets from other nodes and forwards them to the gateway. We analyse two quality-of-service parameters: throughput and packet losses. Our proposed solution indicates that employing a straightforward one-hop relay can enhance throughput up to three times during the transmission process.
A Novel Fundamental PWM Excitation-Based Rotor Position Estimation Method for Precision Sensorless Control of IPMSMs

In sensorless control of interior permanent magnet synchronous motors (IPMSMs), the fundamental PWM excitation (FPE)-based methods use PWM signals excitation and measure the derivative of the stator current as responses to estimate the rotor position. As the signal injection is no more required, the FPE-based methods have the potential to simplify the controller and achieve precision sensorless servo control. However, the current derivative is hard to measure accurately. Therefore, existing FPE-based methods usually suffer from significant position estimation errors. In this paper, a novel FPE-based rotor position estimation method is proposed with high stability and accuracy. Different from existing methods which usually sample current derivative only 2 times per PWM cycle, the proposed method takes 2 to 6 samples, depending on the amplitude and direction of the voltage vector. To make full use of all recent sample points, a first-in-first-out (FIFO)-based least squares algorithm is proposed. The optimal rotor position estimation can be obtained with only a small amount of computation since the analytical solution is given. Simulation results demonstrate that the rotor position can be estimated with an accuracy of 1 electrical degree under various speed and load. Sensorless closed-loop trajectory tracking control based on the proposed method is realized, which shows an exciting prospect of sensorless control in high-performance servo systems.
CPW-Fed Multiband CRLH Antenna for GPS, ISM and 5G Applications

A coplanar waveguide-fed multiband composite right/left-handed (CRLH) antenna, a class of metamaterials (MTMs) is presented in this paper. It is designed by embedding two unit-cells of CRLH transmission line on the top and bottom surfaces of an FR4 epoxy substrate with the help of metallic vias. The multiband characteristic is obtained by generating four resonances due to CRLH unit-cells, feed-patch and the ground plane. The simulated results show three frequency bands spanning over 1.3 to 1.87 GHz, 2.36 to 2.63 GHz and 3.14 to 4.62 GHz with return loss below – 10 dB. The realized gains have been found as 2.5, 2.56, 4.85 and 4.9 dB at the resonant frequencies of 1.57, 2.4, 3.4 and 4.2 GHz respectively. The radiation efficiency is well above 77% at each resonant frequency with a peak value of 94.76%. The proposed antenna is suitable for Global Positioning System (GPS) (1.57 GHz), Industrial, Scientific and Medical (ISM) (2.4 GHz), and 5G sub-6 GHz infrastructure (3.3-4.2 GHz) applications.
Millimeter-wave open resonator-based dielectric characterization of printed circuit boards

In this work, a low-permittivity polymer rod-based open-resonator has been demonstrated for the dielectric characterization of some commonly used printed circuit board substrates at Ka-band (26.5 GHz to 40 GHz). The concept of Fabry-Perot has been adapted at millimeter-wave frequency while ensuring a low-cost and robust design. First, the dielectric parameters and possible dielectric dispersion of the dielectric rod waveguide used in the open-resonator are investigated. This is done by fitting full-wave electromagnetic simulation results to the measured response. It is followed by introducing the test substrates into the resonant cavity of the open-resonator, thereby leading to an electromagnetic perturbation of the resonances. Finally, the dielectric parameters are extracted from the measured resonance frequency shifts for different test substrates. A wide range of relative permittivity is tested in the proposed setup, which features repeatability, considerable sensitivity to dielectric parameters, and relaxed assembly tolerances.
Phase-Correlation Based Sea Ice Motion Tracking and Classification Using Spaceborne SAR Imagery

Sea ice is subject to continual change. It arises as seawater freezes, and is driven and deformed by winds, currents, ocean waves and temperature fluctuations. To observe the sea ice and its motion on a broad scale, Synthetic Aperture Radar (SAR) satellites are well suited, particularly as they provide images of land and frozen waters though clouds and regardless of solar illumination. In this paper, we present a software processor that is intended for the retrieval of high-resolution sea ice drift vector fields from pairs of subsequent, co-located SAR images. The core of the sea ice drift tracking algorithm is the well-known phase correlation technique executed hierarchically in a multiscale Gaussian pyramid. We explore the capabilities of the algorithm with a SAR image time series taken by the European satellite mission Sentinel-1 over the Arctic Ocean offshore close to Cape Morris Jesup during December 2021, when the ocean showed a closed cover of mainly multiyear ice. The retrieved sea ice drift vectors are validated with buoy data. In addition, we applied sea ice type classification on the SAR image series using the drift tracking algorithm for fusing classification results of the individual, subsequent SAR images. In so doing, we overcome inconsistent classification results and overall increase stability and reliability of the classification results.
Fixed-Time Adaptive Neural Prescribed Performance Control for Nonlinear MIMO Singularly Perturbed Systems

This paper focuses on the adaptive neural fixed-time prescribed performance control for a class of multi-input and multi-output (MIMO) nonlinear singularly perturbed systems (SPSs). At first, a fixed-time prescribed performance function is introduced to adjust the transient and steady-state performance of the system, which enables the tracking errors can converge to a preassigned area within a given fixed time. Then, by integrating the fixed-time stability and the backstepping control technique, an adaptive neural fixed-time trajectory tracking controller is designed to guarantee that all the signals in the closed-loop system (CLS) are semi-global uniformly ultimately practically fixed-time bounded. Finally, the effectiveness of the developed control approach is verified through simulation results.
An Optimum Microwave Filter Design Using Groove Gap Waveguide Technology for Low-loss High-power Applications at Ku and Q-band

This paper presents an optimum design of groove gap waveguide filter at Ku and Q-band. The row of bed of nails is varied to improve the in-band performance (insertion loss) of the filter. The concept is validated through third order Chebyshev filter designed with fractional bandwidth 1.92% at 13 GHz and 1.97% at 38GHz respectively. The filter is designed with different number of rows of nails and its performance is simulated. The high-power analysis of the filter is carried out which finds it to be a prospective candidate for high power filter application. The filter designed with groove gap waveguide technology offers the advantage of easier manufacturing compared to cavity filter, which reduces the overall cost involved in the production and makes it a suitable candidate for bulk production.
Analysis of LF Disturbances and Immunity Improvement Techniques for Automotive Distance Ranging Sensors

This paper presents improvement potentials and noise mitigation techniques at the use case of ultrasonic distance ranging sensors for automotive applications. The key element of the product development for improved immunity behavior against noise sources in the low frequency band of below 200 kHz was the fusion of chip level noise quantification using system plausibility check features with the electromagnetic compatibility design optimization of electromechanical subcomponents. For this purpose, empirical and 3D simulation data are generated and analyzed. In addition, radiated immunity measurement methods are presented for the final component evaluation of the low frequency electric and magnetic immunity performance below 200 kHz.
Observing intertidal coastal areas using full-polarimetric C- and X-band synthetic aperture radar measurements

This study is to analyze the multi-polarization/multi-frequency backscattering from intertidal areas using polarimetric Synthetic Aperture Radar (SAR) imagery collected by the C-band Radarsat-2 (RS2) and the X-band Cosmo-SkyMed Second Generation (CSG) satellite missions.
Mangrove Ecosystem Services in the Mekong Delta: Combining Socio-Economic Household Surveying with Remote Sensing based Analyses

Knowledge about the region and occurring classes Introduction Knowing the real value of mangrove ecosystem service is playing an important role in our life, it can be an important feedback signal to the management of human activities in natural ecosystem. Remote sensing data have been used in a wide range of applications such as land cover, biodiversity, species richness monitoring, inventory of forest quality and quantity. The functions and services provided by mangrove ecosystems have positive economic value and these are often ignored in the ongoing precess of mangrove conversion. Therefore, it is an urgent need to develop a valuation model that aquately estimate all mangroves services and functions in the coastal zone areas in the Mekong delta MANGROVE ECOSYSTEM SERVICES IN THE MEKONG DELTA: COMBINING SOCIO-ECONOMIC HOUSEHOLD SURVEYING WITH REMOTE SENSING BASED ANALYSES
Multi-view Canonical Representation Discriminant Analysis

Multi-view classification that classifies samples from heterogeneous views is still a challenging problem in computer vision. The multi-view discriminant analysis is an effective method for this problem based on seeking a common subspace for multi-view data. However, existing methods usually fail to learn optimal discriminant projection matrix due to the possible singularity of the within-class scatter matrix. In this paper, we propose a novel multi-view canonical representation discriminant analysis (MCRDA) approach.Specially, our MCRDA joins the supervised information with common representation extraction to obtain a discriminant common subspace. By utilizing the equivalence of least squares regression (LSR) and linear discriminant analysis (LDA), an efficient iterative optimization algorithm is proposed to solve the method, we perform extensive experiments on several benchmark data sets in comparison with some state-of the-art multi-view discriminant analysis methods. Experimental results illustrate that the proposed method shows promising classification performance.
Beam-steering Transmitarray Antenna for 5G Application

In this work, a linearly polarized, high gain, low profile, symmetrical metasurface-based transmitarray antenna is presented. To design the transmitarray, two RT/duroid 5880 substrates of thickness 0.787 mm are sandwiched between three conducting layers. The geometry of conducting layers in the unit cell is altered accordingly to obtain the desired phase shifting characteristics. These unit cells are then arranged in a particular fashion, obtained from the phase difference equation, to make the transmitarray. The transmitarray is illuminated by a 2×2 microstrip patch antenna array placed at the focal distance (D = 43.2 mm). The F/D ratio of the design is 0.8 which makes it a low-profile antenna. Beam-steering is achieved by moving the feed source along the focal plane. The design transmitarray antenna operates in 25.2-30.5 GHz (BW=19%) band having bandwidth 5.3 GHz. The simulation results show a maximum gain of 17.7 dBi in the broadside direction, scan angle is 46° (-23° to +23°) in both the E-plane and H-plane, with a scan loss of 1.45 dB.
Detection methods of surface defects of sintering material based on machine vision

The iron and steel industry is one of the pillar industries in the national economy. Blast furnace (BF) ironmaking is the core step in long-process ironmaking. Before BF production, to improve the ore quality, sintering is adopted to provide high-quality man-made ore from raw materials. In the sintering process, the material surface state is the main indicator for monitoring the ignition effect. During the actual production process, due to the influence of the ingredients and the ignition effect, there are defects on the sintering material surface, including yellow mud, mouse holes, and cracks. Detection of defect information on the material surface is conducive to ensuring the stable quality of the sinter and the stable operation of sintering production. This paper designs the corresponding detection methods for the three defects based on machine vision algorithms, 1) Yellow mud detection: separate the material surface area of the sintering trolley by semantic segmentation, and judge whether there is yellow mud according to the HSV histogram correlation combined with the shape judgment condition of yellow mud; 2) Mouse hole detection: use the target detection method of YOLOv5 without Mosaic detects mouse holes and improves the detection ability of small targets; 3) Crack detection: transfer learning and improved DeepLabv3+ network semantic segmentation are used for crack detection to improve the accuracy of crack detection. Finally, all methods are applied to the actual production line, and the detection accuracy and effectiveness of the above methods are verified through image testing and calculation of evaluation indicators, which can meet the needs of on-site use.
Design and Implementation of Circular patch antenna for Wi-Fi 7 and 5G applications

This paper present the design & simulation of slotted – circular Micro strip patch antennas which is resonate at 6.5 GHz and 3.5GHz frequencies. The first slotted circular patch antenna operated at 6.5 GHz frequency, which is lies in between (5.925GHz-7.1GHz) of 6GHz frequency band. This frequency range is suitable for future wireless application i.e. Wi-Fi 7. Also other two designs of single slotted – circular Micro strip patch antenna element & its 2×1 element array were implemented and both designs operated at 3.5 GHz frequency & falls in between (3.3GHz- 4.2GHz) band and this range is the birth place of 5th generation communication (5G). The presented antennas were design and simulated by HFSS software.
One-Dimensional Radiation Beam Tilting Using Thin Planner Phase Gradient Metasurfaces Array Lens at millimeter-Wave Band for 5G Applications

In this paper, a thin planner metasurface (MS) lens technique is reported to deflect the radiation beam in predetermined direction at mm-Wave band for 5G applications. The MS lens array consists of phase gradient unit cells which capable to manipulates the phase of the incoming wave and transformed into the tilted beam. The unit cell has a square ring resonator and cross bar slots. The gradient phase is achieved by controlling the length of the square ring resonator slot. The total phase variation by tuning the length of the resonator is achieved 2170 at 28 GHz. To check the authenticity of tilted radiation beam, the phase gradient metasurfaces (PGMS) array lens is fed by a conventional microstrip patch antenna. The patch antenna covers 27.5 – 28.5 GHz band with realized gain of 7.9 dBi at 28 GHz. The MS lens is loaded in the main radiation beam direction of the patch antenna i.e., at the top side. With this, the radiation beam is tilting ≈ 210 from the original radiation beam direction. Moreover, the MS array confined the radiation beam as a result the gain of the patch antenna is significantly increased about 2.17 dBi at 28 GHz.
A Sensorless Parameter Independent Controller for Brushless Doubly-Fed Reluctance Wind Generators

A model reference adaptive system (MRAS) based sensor-less control scheme for variable speed wind power applications of the prominent brushless doubly fed reluctance generator (BDFRG) technology is presented. The machine parameter independence of the field-oriented algorithm, offering robust, inherently decoupled real and reactive power control of the grid-connected winding, is achieved by on-line estimation of the inductance ratio, the underlying rotor angular velocity and position MRAS observer being reliant upon. The excellent power controller performance has been demonstrated by realistic simulation studies using large-scale BDFRG design data.
DC-5 GHz GaAs HEMT Absorptive SP4T Switch

An absorptive single pole four throw (SP4T) broadband MMIC switch is designed using the PE15 GaAs HEMT process of WIN foundry. The designed switch has inbuilt decoder and driver circuitry. This MMIC process has both depletion as well as enhancement (0.5 μm) FET capability where depletion mode FET is used for the design of RF switches while depletion and enhancement mode is used for the design of decoder and its driver circuitry to minimize power consumption. The assembled switch provides greater than 25 dB isolation and less than 2.8 dB insertion loss up to 5 GHz. The return losses are better than 11.5 dB over the entire frequency range and works with the control voltage of 0 and 5V. The switch is realized within the footprint of 3.5mm x 2.5mm x 0.1mm and consumes only 75mW of power.
A Conformal, Planar Inverted F Antenna using Low-Cost Multilayer PET sheet for Vehicular Application

A planar inverted F antenna (PIFA) has been designed using low-cost PET sheets for vehicular application. Energy dispersive X-ray (EDX) and microstrip ring resonator method is used for material characterization of PET sheets. The dielectric properties of PET sheet are found to be єr =2.63 and tanδ =0.004 respectively. The planar PIFA antenna was designed and analyzed using ANSYSS HFSS software. It is evident from the analysis that the PIFA works at its fundamental mode (TM10) for desired frequency band. The proposed antenna is fabricated and tested in planar as well conformal conditions. A good match has been observed between the simulated and the measured results. The measured realized gain of the PIFA antenna on planar and conformal conditions was nearly same (≈ 6.0 dBi). As per the literature survey, it is evident that this is the first attempt to use the reported methodology for conformal PIFA design on PET sheets for vehicular application.
Mechanical Design and Obstacle-avoidance-based Motion Control for Cable-driven Hyper-redundant Manipulator

In this paper, a mechanical design of cable-driven hyper-redundant manipulator (CDHRM) is presented, and for which an obstacle-avoidance-based motion control method is proposed. First, cables are mounted to drive CDHRM, and the actuating subsystem is designed to be separated from the driving subsystem, which makes the redundant degrees of freedom (DOF) and flexibility possible, and makes CDHRM suitable to work in space-restricted environments. Second, based on the structure of CDHRM, the forward and inverse kinematics are established. Then, to implement CDHRM in space-restricted environments, a motion controller is proposed to guarantee both the control accuracy and obstacle avoidance. Finally, the proposed motion control method is verified through simulation and experiment, which demonstrate the effectiveness and feasibility of the proposed method in obstacles avoiding and precise motion controlling of CDHRM.