Miracle-dz/UniFAR-FTUs huggingface dataset:
Research on Drogue Detection Algorithm for Aerial Refueling (IEEE/CSAA GNCC)*

Unmanned aerial vehicle(UAV) has become more and more widely used in military and non-military applications, but endurance has become a major limiting factor in the development of UAV. In order to increase the UAV’s endurance, this paper uses a vision guidance method to achieve automatic aerial refueling technology. This paper proposes an automatic refueling technology based on a deep-learning algorithm for detection. The Faster Rcnn algorithm can simultaneously recognize the fuel receiver and the Drogue at long-distance and returns the center coordinate value of the receiver. If the pixel area of the identified Drogue is greater than a certain threshold, the central coordinate value of the Drogue is returned. The experiment results show that the average accuracy of the algorithm reaches 67.75%, and the real-time performance is about 5HZ.
Investigation of Electric and Electrocaloric Properties for Sm-Doped 71PMN–29PT Ceramics

Sm-doped 0.71Pb(Mg1/3Nb2/3)O3–0.29PbTiO3 ceramics (denoted as xSm-71PMN–29PT, 0 ≤ x ≤ 5 mol. %) were synthesized by sol-gel method. The effects of Sm-doping on the electrical and electrocaloric properties of the 71PMN-29PT were investigated. Among all samples prepared, 3Sm-71PMN–29PT displays the optimal piezoelectric and dielectric properties – piezoelectric coefficient d33 of 1040 pC/N, relative dielectric constant εr of 8078, electromechanical coupling factor kp of 0.60. With the increase of Sm doping amount, the dielectric-peak temperature Tm decreases from 405 K to 318 K. Moreover, the electrocaloric (EC) effect in the related ceramics was calculated via indirect method. Under the electric field of 40 kV/cm, the EC temperature change (ΔT) reach their maximal values when the testing temperature is near Tm. The largest electrocaloric response is found in 71PMN–29PT ceramic at T = 428 K with ΔT = 1.49 K, and the largest room temperature electrocaloric response is found in 5Sm-71PMN–29PT ceramic with ΔT = 0.77 K. The excellent comprehensive electrical properties and room temperature electrocaloric performances make Sm-doped 71PMN–29PT ceramics to be one of the most promising candidates for solid- refrigerator applications.
Attitude Maneuver of Spacecraft With Angular Velocity Constraint

This paper is concerned with a rest-to-rest attitude maneuver of spacecraft subject to angular velocity constraint and external disturbances. An auxiliary sliding vector is first introduced and its state trajectory is restrained a priori by relative prescribed performance functions. Then, an adaptive controller incorporating error transformed technique is proposed, which enables the spacecraft to orientate any specified trajectory with high precision. It is shown that the developed control scheme is not only robust against unexpected environmental disturbances, but also able to ensure the constraint on angular velocity is perfectly fulfilled. Based on the standard Lyapunov theory, all signals in the closed-loop system are proved to be uniformly ultimately bounded. Finally, numerical simulations performed on a microsatellite are presented to illustrate the effectiveness of the proposed control algorithm.
Software Correction of Defective Lossy Transmission Line Networks

In this paper, we pave the way to identify the temporal profile of electromagnetic (EM) sources satisfying particular properties for a given target voltage. For this purpose, we generalize the linear combination of configuration field (LCCF) method in the framework of identifying voltage signals that would generate a specified voltage over a time interval at distinct points of a transmission line (TL) network. In this paper, the LCCF method is applied to bring a voltage software correction to a lossy TL network distorted by an interfering external signal. With a view to consider experimental validations, constraints are then added to the LCCF method to decrease the maximum frequencies of the computed signals.
Deployment trajectory tracking control of tethered satellite system based on fast model predictive control

The stable deployment is one of the key problems for the tethered satellites system (TSS). The deployment of TSS has properties of strong nonlinearity and under-actuated, which is susceptible to external disturbance and parameters uncertainty. This paper proposes the fast model predictive control (FMPC) for the process of deployment with inputs and states constraints. Firstly, the mathematical model of TSS is derived by Lagrange mechanics theory. The nominal deployment trajectory is obtained by using the typical tension control law while parameters in the law are optimized. A fast online controller developed by the model predictive control (MPC) is designed to ensure the precision. To reduce the computation time, the system model is linearized along the nominal trajectory, obtaining a set of linear time varying (LTV) model to be the prediction models. Then, the problem of nominal trajectory tracking with nonlinear model predictive control (NMPC) is transformed into the optimization problem of LTV-MPC scheme by simplifying a nonlinear programming (NP) problem to quadratic programming (QP) problem in each sampling period. The feasibility and rapidity of the proposed controller is verified through numerical case for the deployment of TSS.
Powerful and Low Time Phase-Based Video Magnification Enhancing Technique

Video processing techniques become major role with the wildly spread of smartphones and other new technologies. One of the high impact video processing is a magnification. Magnification refers to amplify a region or special bands of video frames in order to detect subtle information. The famous approach to achieve magnification is Eulerian-based. This paper proposes a developed approach for a phase-based Eulerian video magnification (PB-EVM) in order to reduce the processing time. The proposed approach reduces the processed data in PB-EVM by resizing-down the source video size with maintaining the video quality. Subsequently, the resulted video is decomposed using complex steerable pyramid. Then, the decomposed video is entered to temporal filters in order to pass only specific frequency bands, and then amplified the energy of these bands by multiplying by magnification factor. Finally, the video magnified video is reconstructed by steerable pyramid and resizing-up to come back to the original video size. The experimental results of the proposed approach show that there is a 60–65% reduction in the execution time compare to the conventional PB-EVM. Furthermore, the magnified video quality is maintained as it in the conventional PB-EVM.
Grasp It Like a Pro: Grasp of Unknown Objects With Robotic Hands Based on Skilled Human Expertise

This work proposes a method to grasp unknown objects with robotic hands based on demonstrations by a skilled human operator. Not only are humans efficacious at grasping with their own hands but are also capable of grasping objects using robotic hands. Therefore, we consider how the grasping skills of a human trained in robotic hand use can be transferred to a robot equipped with the same hand. We propose that a skilled human user manually operates the robotic hand to grasp a number of elementary objects, consisting of different boxes. A Decision Tree Regressor is trained on the data acquired from the human operator to generate hand poses able to grasp a general box. This is extended to grasp objects of unknown and general shape leveraging upon the state-of-the-art Minimum Volume Bounding Box decomposition algorithm that approximates with a number of boxes the point cloud of the object. We report on extensive tests of the proposed approach on a Panda manipulator equipped with a Pisa/IIT SoftHand, achieving a success rate of 86.7% over 105 grasps of 21 different objects.
Combining Machine Learning and Behavior Analysis Techniques for Network Security

Network traffic attacks are increasingly common and varied, this is a big problem especially when the target network is centralized. The creation of IDS (Intrusion Detection Systems) capable of detecting various types of attacks is necessary. Machine learning algorithms are widely used in the classification of data, bringing a good result in the area of computer networks. In addition, the analysis of entropy and distance between data sets are also very effective in detecting anomalies. However, each technique has its limitations, so this work aims to study their combination in order to improve their performance and create a new intrusion detection system capable of well detect some of the most common attacks. Reliability indices will be used as metrics to the combination decision and they will be updated in each new dataset according to the decision made earlier.
Dynamic hand gesture recognition based on textural features

This article proposes an implementation of a dynamic gesture recognition system using different textural descriptors such as the basic Local Binary Patterns (LBP), Rotation Invariant and Uniform LBP (LBPriu2), Center-Symmetric LBP (CS-LBP) and Edge Histogram Descriptor (EHD). The recognition task is performed using two variants of the Artificial Neural Network (ANN), which are the Multilayer Perceptron (MLP) and the Radial Basis Function neural network (RBF). Experiments were performed on a user-independent database with a simple background where 95.83% recognition rate was achieved. A comparison with previous works shows the efficiency of our system.
High-power laser beam formation and focusing by means of adaptive optics : (Invited)

The transformation of an intensity distribution from Gaussian to a flattop, doughnut, etc. is a very important task due to rapid development of laser technology and its applications. And the necessary result could be obtained with the use of flexible deformable mirrors that changes the phase of the beam and modifies the shape of the focal spot in the farfield zone. In this paper, we present the theoretical and experimental results of the flattop and doughnut beam formation with the use of a bimorph and stacked-actuator deformable mirrors as well as LC phase modulator.
Research on Ultrasonic Damage Imaging Based on Total Focus Method

Ultrasonic phased array Total Focus Method (TFM) is used to process the signal with the data obtained by the Full Matrix Capture(FMC) mode, which has the advantages of high imaging accuracy and high signal-to-noise ratio(SNR). However, the frequency dispersion of the Lamb wave largelyaffected the imaging accuracy of the TFM. Therefore, the wavelet analysis time domain filtering in multi-band method was proposed to decompose an ultrasonic wide frequency band signal into several narrow band ones for suppressing dispersion effect, furthermore, the damage signal is extracted without reference signal and thus the damage is imaged in frequency domain, which improves the imaging accuracy. In this paper also analyzes the whole process of ultrasonic excitation, the interaction between the incident wavefield and damage as well as the sensor receiving signal, and establishes a quantitative imaging method of inverse scattering model with the reflectivity of the damaged surface as the index,further improve the imaging accuracy. Moreover, a numerical model and an experimental platform for prefabricated artificial damage of metal aluminum plate were established to compare the imaging effects of TFM in frequency domain and TFM with inverse scattering model in frequency domain. The results show that new algorithm is more accurate in locating damage and has stronger characterization ability.
Ocean bathymetry as an inverse problem for the radiative transfer equation

We consider the bathymetry problem which is based on the mathematical model of the acoustic signal propagation in a fluctuating medium. Solution of the direct problem for determination of the flux density is obtained in the double scattering approximation. The inverse problem is formulated as determination of the function describing deviation from a reference value. As a solution to the problem, a non-linear differential equation is obtained with some assumptions for the directivity pattern of the receiving antenna. A numerical analysis of the bathymetry problem is conducted, and the influence of a double scattering signal on the reconstruction of the bathymetric function is investigated.
A New Replay Attack Against Automatic Speaker Verification Systems

With the increasing popularity of automatic speaker verification (ASV), the reliability of ASV systems has also gained importance. ASV is vulnerable to various spoofing attacks, especially replay attacks. Thus, recent public competitions and studies based on spoofing attack detection for ASV have mainly focused on the detection of replay attacks. Generally, replayed speech includes the attributes of one playback and two recording devices: the playback device, the recording device used by the attacker, and the recording device embedded in any system to verify input utterances. Therefore, the main attributes differentiating a replayed speech from the genuine speech are the attributes of the playback and the recording devices used by the attacker. In this paper, we propose a novel replay attack and its defense through observation of the general speech-spoofing process. The proposed attack includes only the attribute of one recording device embedded in an ASV system; genuine speech passes through the recording device only once, and the replayed speech produced for the proposed attack passes through the same recording device twice. Because the proposed attack is feasible, it can be considered a new task for replay countermeasures in the training process in order to develop a robust ASV protection system. The experimental results show that this novel replay attack cannot be detected by several of the existing state-of-the-art replay attack detection systems. Furthermore, the new attack can be detected by the same systems successfully if they are retrained with an appropriate dataset designed for the new task.
Comparative study of a self-excited induction and synchronous reluctance generators capabilities

The paper compares the performance of aero-generators for a low-power wind application in an isolated site focused on a conventional squirrel-cage induction generator and an innovative synchronous reluctance generator characterized by their simple and rugged structure (low cost), and reliability (lowest maintenance). This study is based on an exhaustive review of the state of research in this field. To facilitate the comparison, we used two machines with the same power (1kW), the same speed (1500 rpm), and the same stator lamination and winding. However, the machine’s rotors are different. We analyzed the self-excitation criteria, we specified the electrical models of the two machines, and then performed various simulations for different load regimes, using the MATLABSimulink software. The results of these simulations are discussed and validated by experimental tests.
A Novel Microstrip Dual-Band Bandpass Filter Design with Harmonic-Suppression

In this article, a novel microstrip dual-band bandpass filter is designed with harmonic suppression. The design employs source loaded feeding technique to act with double role: feeding the structure and eliminating harmonics at the same time. The employed method gives a solution to suppress harmonics without introducing large extension in filter dimensions which is a great advantage. The first undesirable harmonic was cleaned from the second passband of the filter and in addition the out-of-band attenuation is improved. A prototype is fabricated to validate the design and the filter dimension is $25.8 \times 22$ mm2. The measured out-of-band attenuation levels are better than -20dB up to 10GHz. The measured insertion losses are better than 1.5dB at both passband center frequencies 2.44 GHz and 5.75 GHz. The measured results are in good agreement with the simulated ones and the proposed filter can be used for WLAN application.
Zero-Sequence Current Suppression for Open-Winding Permanent Magnet Brushless Motor Driving System Based on Second Order Generalized Integrator

The open-winding driving system can improve power density and torque output capacity of the motor. However, the open-winding topology with a common direct current (DC) power supply provides a path for the zero-sequence current, which contributes to the power loss but not the torque output. The zero-sequence current is produced by the common-mode voltage and zero-sequence components of the back electromotive force (EMF). For the purpose of eliminating the common-mode voltage as well as improving the utilization of DC supply voltage, a 120° decoupling space vector pulse width modulation strategy is adopted. Meanwhile, a proportional unit combined with second order generalized integrator (SOGI) is proposed to suppress the zero-sequence current caused by the zero-sequence components of the back EMF. A test bench is built for the experiment. The effectiveness of the proposed suppression strategy is verified by the experimental results.
Comparative analysis of machine learning classification of time series with fractal properties

The article analyses the classification of time series according to their fractal properties by machine learning. The classification was carried out using neural networks and the random forest method. Objects were the model fractal time series with given the Hurst exponent. Each class was a set of time series with the Hurst exponent values in a predetermined range. Input features were the values of time series. It was demonstrated that in this case the classification accuracy is high enough. The most accurate classification results were obtained using recurrent neural network. The proposed method can be readily used in practice for recognition, classification and clustering of time series with fractal properties.
Design and Verification of ECC Scheme to optimize area and tester time in OTP ROM Controller

The One Time Programmable ROM consists of bitcells of efuse which consists of programming transistor and Fuse Link. High densities of current through the Fuse link, causes the metal to electromigrate which creates high resistance path through the fuse. The resistance of an unblown fuse is very less and that of a blown fuse is more in the order of kilo ohms. The metal fuses tend to regrow over time and usage. In digital logic, this would translate to a value of 1 of a blown fuse, flipping to a value of 0 in the unblown state. Redundancy techniques are used in OTP controller to correct and detect such errors. It borrows the FEC 63/56 (Forward Error Correction) scheme and a shadow redundancy technique to provide a redundant fuse for every regular fuse-the protection is in such a way that even if one of the fuse bits fail, the other good fuse bit will help. But with the current stable fabrication technology, high Stress Test samples on different wafers of various technologies have shown very good yield and no aging related errors, i.e errors are lesser than 1 ppm. Hence the inference is that the current shadow and FEC ECC scheme employed is an overkill and implementation need to be reconsidered. In this paper, an alternative ECC scheme is developed which provides the recommended redundancy support with fewer fuse bits, by which we achieve the area and tester time reduction. The Register Transfer Logic for Hamming Code and Checksum has been developed and integrated into the architecture of One Time Programmable Read Only Memory Controller. Core level and chip level verification has been done. Synthesis results show that area of the memory is reduced from 0.19 mm2to 0.12 mm2and the reduction in tester time is from 1000–1200 ms.
Dual-Band Shared-Aperture Reflectarray Antenna Element at Ku-Band for the TT&C Application of a Geostationary Satellite

A dual-band reflectarray microstrip patch antenna element is presented in this paper. The concept of polarization diversity is effectively utilized in the design with the cross-polarization level obtained well below -25dB in both the principal planes. This supports the implementation of dual-band operation from the same element. The two orthogonal modes of a rectangular patch: TM01, and TM10, are exploited for the dual-band operation. The inherent narrow bandwidth of the element fulfils the requirement of the present work at both the downlink and uplink frequencies of 11.4 GHz and 13.2 GHz respectively. The bandwidth is measured to be 2% to 3%, which effectively keeps the design simple. Also, a good port isolation of 27 dB at downlink band and 20 dB at uplink band are observed. A measured return loss of 17.7 dB at 11.4 GHz and 26 dB at 13.2 GHz are obtained with an acceptable deviation of only 0.65% (75 MHz) at downlink frequency. Based on this element a configuration for dual-band reflectarray is also proposed.
Multi-channel Complex for Non-contact Aggressive Movement Detection

The paper presents a multi-channel complex for non-contact movement detection, which consists of bioradar sensors and an RGB-D camera. The proposed system was validated on an experimental dataset of scenarios performed by 10 volunteers (3 males and 7 females) in the age group between 20 and 36 years participating in the study. All subjects gave their informed consent prior to the start of the experiments. During the experiments, the signals from two bioradars were recorded simultaneously with the data from the RGB-D camera. Each subject was asked to perform 11 different types of common everyday motion patterns and aggressive movements, each repeated three times. During the experiments, 330 records corresponding to non-aggressive activities and 30 to aggressive behavior were collected. The proposed classification algorithm showed 98% accuracy and Cohen's kappa of 78% for the non-aggressive/aggressive behavior classification. The future activity will consider expanding the dataset considering different surrounding and lighting conditions.
A Study with Simulation of Range Free Localization Techniques in Wireless Sensors Networks

Wireless sensors networks are used in several fields of application, in most applications, knowing the location of the sensors nodes is necessary. According to the distribution of the calculations on sensors nodes, the localization techniques are classified into two techniques: centralized and decentralized (distributed). Distributed localization techniques can be classified into two categories: range free and range based. DV-HOP is a range free simple localization algorithm, but it has low localization accuracy, despite the improvements of the proposed DV-Hop algorithms. Maintaining a balance between a high location accuracy and good stability and simplicity is always a challenge. In this article, we have focused our study on the localization algorithm range free DV-HOP, the study is based on the accuracy error which is the most important factor in the localization. To better study the DV-HOP algorithm, we implemented DV-HOP using MATLAB. The purpose of this article is to present Range Free localization techniques and open up a perspective of proposing new localization techniques in wireless sensors networks.