Miracle-dz/UniFAR-FTUs huggingface dataset:
HOG and HOOF Spatio-Temporal Descriptors for Gesture Recognition

This article presents a gesture recognition system based on spatio-temporal descriptors such as Histogram of Oriented Gradients 3DHOG, Histogram of Oriented Optical Flow 3DHOOF. One-against-all SVM classifier is used to classify each gesture belonging to a predefined class using a dynamic dataset. Our method consists of implementing three architectures for our classification task: 3DHOG, 3DHOOF, 3DHOG-HOOF, and investigate the benefit of concatenating the two descriptors. Good recognition rate was obtained for the third architecture where 91.66% of efficiency was obtained.
Preprocessing Aided Spatial Modulation for Multi-User MIMO Downlink Transmission with Imperfect CSIT

In this paper, the preprocessing aided spatial modulation (PSM) is introduced for the downlink transmission in multi-user multiple-input multiple-output (MIMO) systems. In the proposed PSM scheme, the channel state information at transmitter (CSIT) is utilized to reduce the impact of the multi-user interference, while enabling successful signal detection at each user. We present a zero-forcing (ZF) preprocessing method that is designed in two stages. Moreover, this approach is extended to generalized preprocessing aided spatial modulation (GPSM), which significantly enhances the bandwidth efficiency of the proposed method. Since acquiring perfect CSIT is difficult in some scenarios, the proposed preprocessing technique is also adapted in presence of channel uncertainty. The simulation results indicate that the proposed PSM scheme outperforms the existing multi-user SM scenarios. Furthermore, the proposed scheme outperforms conventional multi-user MIMO scheme, while yielding satisfying performance in the case of erroneous channel estimation and low correlated channels.
No-Reference Image Quality Assessment using Transfer Learning

With the recent advancements in deep learning, high performance neural networks have been introduced. These neural networks also can be used to solve similar problems in a transfer learning approach. Recently, several state-of-the-art Convolutional Neural Networks (CNNs) are proposed for computer vision tasks. On the other hand, in-the-wild No-Reference (Blind) Image Quality Assessment (NR-IQA) problem is known as a challenging human perceptual problem. In this paper, a transfer learning approach is used to solve the problem of in-the-wild NR-IQA. With a few training times, the proposed neural network exceeds all the previous methods which are not using deep neural networks. Further, the proposed method predicts the opinion score distribution in its output which has more valuable information than single Mean Opinion Score (MOS). Moreover, the proposed method can accept arbitrary image size in its input which is often not applicable in the most CNNs which have a certain output size.
Single Carrier PWM Strategy for Grid Connected PV Transformerless Cascade Multilevel Inverters

Single-phase cascade multilevel inverters (CMI) allow to feed loads with multiple voltage levels, which reduces the total harmonic distortion (THD) when compared with traditional three-level inverters. Reducing the THD makes the filter size smaller and cheaper which contributes to improve the overall performance of the power converter. These advantages make CMI attractive in several applications like: photovoltaic (PV) systems, active filtering, motor drives, among others. Transformerless grid-connected PV systems require a specific design of the pulse width modulation (PWM) strategy in order to deal with the common mode current (CMC) issue. Then, five levels CMI can be controlled by using different PWM strategies since the electrical circuit can be configured in multiple combinations. In this paper, a PWM sequence is proposed in order to deal with CMC issue in a CMI devoted to transformerless PV systems. Numerical and experimental results show the proper operation of the inverter and the reduction of the CMC.
A Circularly Polarized Differentially Fed Transmission-Line-Excited Magnetoelectric Dipole Antenna Array for 5G Applications

A circularly polarized (CP) differentially fed magnetoelectric dipole (ME-dipole) array is proposed for fifth-generation applications. The proposed transmission-line-excited antenna, fabricated on a printed circuit board, can achieve wide impedance and axial ratio (AR) bandwidths and high gain. The antenna consists of a $2 \times 2$ ME-dipole array enclosed by a circular cavity. It is modified from our previous work on linearly polarized (LP) array with its element orientation selectively rotated by ±45° with respect to the differentially fed transmission line and the use of sequential rotation technique to generate CP radiation. A differential feed network is utilized to feed the prototype for experiments. Experiments show that the antenna can present an overlapping impedance and AR bandwidth of 32.2% from 52.2 to 72.2 GHz with a broadside left-handed CP gain from 10.2 to 11.8 dBic. The proposed CP antenna retains all the salient features of our previously proposed LP antenna in symmetric and stable radiation patterns and relatively low back radiation levels.
Introducing a Mixed-Mode Matrix for Investigation of Wireless Communication Related to Orbital Angular Momentum

This paper introduces a mixed-mode matrix representation of scattering parameters that is suitable for the investigation of wireless communication based on orbital angular momentum (OAM). For this purpose, a unitary transformation matrix is defined, which contains the transmitted and received amplitudes as basis vectors corresponding to OAM-based communication between two antenna arrays. The mixed-mode matrix is then obtained from the corresponding similarity transformation of the standard scattering matrix available, e.g., from numerical simulations or measurements. The mixed-mode matrix allows better physical insight into OAM-based communication by clearly separating all modes and is more efficient than postprocessing of single-antenna results in a system simulator. Mode conversion/isolation and proper mode termination can be easily quantified. Also, it allows generalizing the interpretation of OAM-based communication by focusing on the property of a constant phase difference within each antenna array. The usefulness of this approach is demonstrated using method of moments (MoM) simulations of dipole radiators in various arrangements of a transmitting and a receiving array. Systematic parameter studies that reveal dependencies of OAM-based communication are possible by using the mixed-mode matrix. As an application, communication patterns are studied, in order to obtain the suitable position and relative orientation in space for good mode isolation or communication.
Wrinkled Soft Sensor With Variable Afferent Morphology

There is an increasing interest in morphological computation due to its advantages in exploring underlying mechanism of soft robotics, especially in tactile sensing. This letter introduces the idea of variable afferent network morphology (VANmorph) for describing the phenomenon that morphology change of soft sensor varies the sensing capability. The characteristics of VANmorph are verified and evaluated based on a novel prototype of sensorized soft body inspired by water-induced wrinkle morphology of human fingers. Preliminary results reveal the advantages of such design in introducing multiple sensitivities to both normal indention and tangential sliding stimuli, and demonstrate potentials in future development of active tactile sensing system.
Stable Torque Optimization for Redundant Robots Using a Short Preview

We consider the known phenomenon of torque oscillations and motion instabilities that occur in redundant robots during the execution of sufficiently long Cartesian trajectories when the joint torque is instantaneously minimized. In the framework of on-line local redundancy resolution methods, we propose basic variations of the minimum torque scheme to address this issue. Either the joint torque norm is minimized over two successive discrete-time samples using a short preview window, or we minimize the norm of the difference with respect to a desired momentum-damping joint torque, or the two schemes are combined together. The resulting local control methods are all formulated as well-posed linear-quadratic problems, and their closed-form solutions also generate low joint velocities while addressing the primary torque optimization objectives. Stable and consistent behaviors are obtained along short or long Cartesian position trajectories, as illustrated with simulations on a 3R planar arm and with experiments on a 7R KUKA LWR robot.
Multilayer RGBD-Video Completion for Hole Filling in 3D-View Synthesis

Recent advances in video completion have made it possible to plausibly fill in large missing regions for a wide variety of unconstrained scenes captured with a freely moving camera. These advances enable automatic generation of high-quality background plates for filling holes during virtual-view synthesis. Most hole-filling approaches, however, still tend to impose restrictive assumptions, such as approximating the background as a single plane, or they forgo background reconstruction by copying from other input-video frames altogether. Moreover, all existing approaches either directly or indirectly rely on binary separation of the scene into background and foreground, which is sometimes not possible. In this paper we propose a multilayer extension of the video-completion algorithm in [5] to RGBD video and demonstrate its advantages compared with alternative approaches when filling holes for 3D-view synthesis.
Sorting of the Neuroendocrine Secretory Protein Secretogranin II into the Regulated Secretory Pathway

Secretogranin II (SgII) belongs to the granin family of prohormones widely distributed in dense-core secretory granules (DCGs) of endocrine, neuroendocrine, and neuronal cells, including sympathoadrenal chromaffin cells. The mechanisms by which secretory proteins, and granins in particular, are sorted into the regulated secretory pathway are unsettled. We designed a strategy based on novel chimeric forms of human SgII fused to fluorescent (green fluorescent protein) or chemiluminescent (embryonic alkaline phosphatase) reporters to identify trafficking determinants mediating DCG targeting of SgII in sympathoadrenal cells. Three-dimensional deconvolution fluorescence microscopy and secretagogue-stimulated release studies demonstrate that SgII chimeras are correctly targeted to DCGs and released by exocytosis in PC12 and primary chromaffin cells. Results from a Golgi-retained mutant form of SgII suggest that sorting of SgII into DCGs depends on a saturable sorting machinery at the trans-Golgi/trans-Golgi network. Truncation analyses reveal the presence of DCG-targeting signals within both the N- and C-terminal regions of SgII, with the putative α-helix-containing SgII-(25-41) and SgII-(334-348) acting as sufficient, independent sorting domains. This study defines sequence features of SgII mediating vesicular targeting in sympathoadrenal cells and suggests a mechanism by which discrete domains of the molecule function in sorting, perhaps by virtue of a particular arrangement in tertiary structure and/or interaction with a specific component of the DCG membrane.
Influence of the Constitutive Contact Law on the Anisotropic Material Parameters of Sheet-Layered Lamination Stacks

The specific design of components like rotor and stator as sheet-layered lamination stacks results in a structural behavior that is heavily dependent on the sheet interactions on the microscale. Due to the manufacturing process, these thin laminations may be just stacked and held together e.g. by welding or clamps, such that frictional contact of rough surfaces between single sheets is taking place and significantly affects the overall deformation behavior. Here, the elastic anisotropic, more precisely transversely isotropic, material parameters describing these lamination stacks are identified with the help of the homogenization taking efficiently care of the microstructure. For this purpose, different constitutive contact laws in normal direction capturing the sheet interactions by a penalty formulation and their effect on the macroscopic quantities are presented to emphasize the importance of this model parameter. Furthermore, it is shown that the derived stress-strain relation is identical to results of a numerical homogenization, where a representative volume element is simulated by the Finite-Element method incorporating Zero-Thickness elements for the contact simulation. The numerical results are finally compared to experiments showing a good accordance.
BER Comparison of OFDM with M-QAM Modulation Scheme of AWGN and Rayleigh Fading Channels

The wireless channel environment is critical to develop wireless communication. In Quadrature Amplitude Modulation (QAM), the constellation points are in square grid with equal vertical and horizontal spacing. Because of higher order modulation formats, more bit per symbol can be transmitted. M-QAM is the efficient digital modulation method because of its higher constellation points. In this paper, the Bit Error Rate (BER) performance of Orthogonal Frequency Division Multiplexing (OFDM) systems and different arrays of QAM (4, 8, 16, and 64-QAM) modulation techniques has been compared under the Rayleigh fading and Additive White Gaussian Noise (AWGN) channels. All the simulations are carried out in MATLAB. The investigation results shows that the Quadrature Phase Shift Keying (QPSK) modulation scheme gives the best performance in term of BER in OFDM system compared to the M-QAM modulation scheme.
A Smart Blood Bag Management System Using a Load-Integrated U-Shaped Near-Field RFID Antenna Array

For improving transfusion safety, a smart blood bag management system using a load-integrated U-shaped near-field antenna (LUNA) array is proposed in this paper. The proposed system consists of four LUNAs for ID sensing with blood information and a switching circuit for the sensing of blood bag localization. The LUNA, which is well impedance-matched within the universal ultrahigh-frequency radio frequency identification band, operates in the near-field region for precise localization, and includes a lumped Lattice-type $LC$ -balun which is exploited to cancel out currents through the ground plane of the LUNA and to obtain opposite directional currents in order to reinforce the magnetic field between two microstrip lines in the LUNA. Using a single-pole four-throw switching circuit, a centimeter-level precise localization of blood bags can be achieved. The proposed system can be used to prevent the mishandling of blood transfusions and to manage blood bags remotely and effectively.
Hardware-in-the-Loop Methods for Real-Time Frequency-Response Measurements of on-Board Power Distribution Systems

The operation of more electric aircraft is dependent on the embedded power grid. Therefore, the on-board power-distribution system must be reliable, having a high level of survivability, and promptly respond to any change in aircraft's operation. Recent studies have presented a number of frequency-response-based tools with which to analyze both single- and multiconverter systems. The methods can be efficiently applied for on-board system analysis, stability assessment, and adaptive control design. Most often, wideband measurement techniques have been applied to obtain the frequency response from a specific converter or a subsystem required for the analysis. In the methods, a broadband excitation such as a pseudorandom binary sequence (PRBS) is used as an external injection, and Fourier techniques are applied to extract the spectral information. This paper presents implementation techniques of the wideband methods using power-hardware-in-the-loop measurements based on OPAL-RT real-time simulator. The presented methods make it possible to modify the system characteristics, such as impedance behavior, in real time, thereby providing means for various stability and control design tools for on-board power distribution systems. Experimental measurements are shown from a high-power energy distribution system recently developed at DNV GL, Arnhem, The Netherlands.
Single-Shot Analysis of Refractive Shape Using Convolutional Neural Networks

The appearance of a transparent object is determined by a combination of refraction and reflection, as governed by a complex function of its shape as well as the surrounding environment. Prior works on 3D reconstruction have largely ignored transparent objects due to this challenge, yet they occur frequently in real-world scenes. This paper presents an approach to estimate depths and normals for transparent objects using a single image acquired under a distant but otherwise arbitrary environment map. In particular, we use a deep convolutional neural network (CNN) for this task. Unlike opaque objects, it is challenging to acquire ground truth training data for refractive objects, thus, we propose to use a large-scale synthetic dataset. To accurately capture the image formation process, we use a physically-based renderer. We demonstrate that a CNN trained on our dataset learns to reconstruct shape and estimate segmentation boundaries for transparent objects using a single image, while also achieving generalization to real images at test time. In experiments, we extensively study the properties of our dataset and compare to baselines demonstrating its utility.
Multi-Aspect Environment Mapping with a Group of Mobile Robots

Environment mapping is crucial for proper decision making in multi-robot systems. We propose multi-aspect mapping technology for a group of mobile robots that allows to perceive surrounding objects both at the level of fine-grained geometry and at the level of their semantic representation. The inputs of the presented mapping subsystem are series of RGB-D streams from multiple robots combined with their navigation information. The primary output is a set of discovered objects associated with their corresponding visual and semantic descriptions. The results of the conducted experiments confirm the sustainability of the proposed approach for exploration of indoor environments.
A DNN-based Mandarin-Tibetan cross-lingual speech synthesis

The paper proposed a deep neural network (DNN)-based Mandarin-Tibetan cross-lingual speech synthesis by adopting speaker adaptation training. The initial and the final are used as the speech synthesis units for both Mandarin and Tibetan to train a set of average voice model(AVM) based on DNN from a large Mandarin multi-speaker corpus and a small Tibetan one-speaker corpus. The speaker adaption is adopted to train a set of speaker-dependent DNN models of Mandarin or Tibetan appended with AVM. The Mandarin speech or Tibetan speech is then synthesized by their respective speaker-dependent DNN acoustic models. Both subjective evaluations and objective tests show that synthesized Tibetan speech by the proposed method are not only better than the traditional Hidden Markov Model(HMM)-based method, but also better than the DNN-based Tibetan speech synthesis with only Tibetan training corpus. Mixed Tibetan training speech have little effect on the quality of synthesized Mandarin speech. Therefore, the proposed method can be applied to the speech synthesis of minority language with rare speech resources.
Sequential Topic Modeling for Efficient Analysis of Traffic Scenes

A two-level Sparse Topical Coding (STC) topic model is proposed in this paper for analyzing video sequences of traffic surveillance containing hierarchical patterns accompanied by complicated motions and co-occurrences. In order to automatically cluster optical flow features into motion patterns, a first level STC model is used. Next, the second level STC model is applied for clustering motion patterns into traffic phases. The effectiveness of the suggested method is proved by experiments on a traffic dataset in the real world. Our simulations show that the proposed two-level STC is able to extract the motion patterns and traffic phases accurately, leading to realistic describing the traffic videos.
Pattern Reconfigurable Microstrip Antenna With Multidirectional Beam for Wireless Communication

In this communication, a compact pattern reconfigurable microstrip antenna with multidirectional beam is investigated. The proposed antenna has a simple structure and consists of an aperture feed microstrip antenna, two metal walls, and six p-i-n diodes. The metal wall connects to the ground plane by p-i-n diodes. By switching between different states of the p-i-n diodes, the proposed antenna can realize six radiation pattern modes, which are a narrow beamwidth pattern, a wide beamwidth pattern, and four directional patterns in the xoz plane and yoz plane. Meanwhile, the operating frequency band of the antenna is always in the bandwidth from 3.5 to 3.9 GHz. The cross polarization of the antenna in the whole modes is very low. The antenna is fabricated and measured to verify the design. The measured results are in good agreements with the simulated one. Owing to a novel design, good pattern reconfigurable characteristics of the proposed antenna have been obtained in the whole frequency band. It is a good candidate for the wireless communication system.
A phage protein that binds φC31 integrase to switch its directionality

The serine integrase, Int, from the Streptomyces phage φC31 mediates the integration and excision of the phage genome into and out of the host chromosome. Integrases usually require a recombination directionality factor (RDF) or Xis to control integration and excision and, as φC31 Int only mediates integration in the absence of other phage proteins, we sought to identify a φC31 RDF. Here we report that the φC31 early protein, gp3 activated attL x attR recombination and inhibited attP x attB recombination. Gp3 binds to Int in solution and when Int is bound to the attachment sites. Kinetic analysis of the excision reaction suggested that gp3 modifies the interactions between Int and the substrates to form an active recombinase. In the presence of gp3, Int assembles an excision synaptic complex and the accumulation of the integration complex is inhibited. The structure of the excision synaptic complex, like that of the hyperactive mutant of Int, IntE449K, appeared to be biased towards one that favours the production of correctly joined products. The functional properties of φC31 gp3 resemble those of the evolutionarily unrelated RDF from phage Bxb1, suggesting that these two RDFs have arisen through convergent evolution.
A Compact Wideband High-Gain Metasurface-Lens-Corrected Conical Horn Antenna

In this letter, a compact wideband high-gain metasurface-lens-corrected conical horn (meta-horn) antenna is developed. A metasurface lens that has a thickness of less than 0.1 λ is developed to provide wideband transmission phase compensation with high transmission efficiency. The ultrathin lens is then used to develop a wideband high-gain horn antenna that has a shorter horn length and a large flare angle, resulting in a compact horn structure that is easy to be fabricated and mounted, and at a low cost. Simulations and experiments were conducted to demonstrate the effectiveness of the design. Measured results show that the meta-horn has a peak gain of 24.2 dBi and a 3 dB gain bandwidth of over 26%.