A quad-band filtering antenna based on a slotted half-mode substrate-integrated waveguide cavity is proposed. Three cavity edges are shorted by metallic posts and one edge is opened. Then three rectangular slots are etched to obtain multi-band operations and coaxial feeding is employed. Four radiation frequencies with similar field distributions but different resonating size can effectively radiate

Accurate prediction of intended gait speed is crucial for facilitating volitional muscle activity during robot-assisted gait training. Considering that most patients find it difficult to perform gait at relatively high speeds, it is also imperative that the prediction model performs well at slow gait speed. Furthermore, ample time for signal processing should be given prior to robot assistance such

The sigmoid activation function plays an essential role in implementing neural networks in hardware. However, due to a high degree of non-linearity, the hardware implementation of the activation function itself is a daunting job. In this Letter, the authors proposed an accuracy controlled iterative algorithm for the piecewise linear approximation of the sigmoid function. The proposed algorithm approximates

A background calibration technique is proposed to correct bit weights in pipelined-successive-approximation-register (SAR) analogue-to-digital converters (ADCs). By splitting the second stage, the input signal interference is mostly removed, thereby greatly enhancing the convergence speed of the algorithm. Besides, the dither signal assists to eliminate mismatch issues between the partially split ADCs

This Letter presents an improvement of disparity map refinement stage using adaptive least square plane fitting technique. This technique is proposed to increase the accuracy on the final stage of stereo matching algorithm. Fundamentally, the accuracy of matching process depends on the robustness of an algorithm on the plain colour region, depth discontinuity and repetitive pattern area. These regions

A novel deep-learning-based method for semantic segmentation of RGB and thermal images is introduced. The proposed method employs a novel neural network design for multi-modal fusion based on multi-resolution patch processing. A novel decoder module is introduced to fuse the RGB and thermal features extracted by separate encoder streams. Experimental results on synthetic and real-world data demonstrate

Digital multitoning is an advanced form of halftoning-based printing technique which renders multiple tones at each pixel of an image. This superior scheme delivers an improved print quality in terms of smooth texture, homogeneity and the suppression of artefacts. This Letter examines the potential scope of multitoning as an effective strategy to embed a binary watermark within a multitoned image.

In this Letter, a multiscale kurtosis maps fusion method is proposed for small infrared target detection. The authors have made two main contributions: first, they propose the scheme of using multiscale kurtosis maps to match the shape and the size of the small target; second, they present a dot product operation to achieve the fusion of multiscale kurtosis maps. Experimental results show that the

While promising progress has been achieved in the zero-shot learning (ZSL) task. The existing approaches still suffer from the strong bias problem between the unseen and seen classes. This Letter presents a unified feature generating framework equipped with a boundary decision loss to tackle this issue in ZSL. Specifically, the hybrid semantic and visual classification strategy is proposed, which can

A design of 4/6 intertrack-interference (ITI)-mitigating error correction modulation code for bit-patterned media recording systems is proposed in this Letter. Generally, coding schemes in data storage devices are usually accomplished using a combination of error-correction coding and modulation coding. However, an interesting approach is that the modulation code itself has the capability of correcting

This Letter presents a dual-mode substrate integrated coaxial line (SICL) based bandpass filter for -band application. The proposed bandpass filter is realised by exciting the even and odd modes in an SICL ring resonator. A novel perturbation technique to control the coupling between orthogonal modes is realised by varying the width of the outer conductor formed by metallic vias in this planar coaxial

In this Letter, a new dual-band filtering power divider (FPD) with high isolation and high frequency selectivity by using self-packaged substrate integrated suspended line (SISL) technology has been developed. Both passbands of the proposed FPD can be designed and controlled individually. A pair of transmission zeros at either passband which are due to the multiple coupling paths with electric/magnetic

A self-diplexing mixed-coupling bandpass filter based on a single slotted substrate-integrated-waveguide (SIW) cavity is proposed. By etching a wide slot, two unequal half-mode SIW parts are constructed and then fed by four coaxial ports to realise two bandpass filters with different centre frequencies. Since this etched slot can serve as a divider and an isolator, a flexible frequency ratio of 0.60–1

The accuracy of contact resistance values of two-dimensional (2D) field-effect transistors extracted with the Y -function considering the impact of the intrinsic mobility degradation is evaluated here. The difference between methodologies that take this factor into account and ignore it is pointed out by a detailed analysis of the approximations of the transport model used for each extraction. In contrast

In this Letter, a recorded single channel of 6.915-Gbit/s white-light visible light communication (VLC) system is reported and experimentally demonstrated. By optimising the bit-loading algorithm onto the direct-current optical OFDM signal and without using an optical blue filter, the high data rate can be achieved. After a free-space propagation distance of 1.5 m, the white-light beam diameter of

The authors experimentally demonstrate an ultra-low repetition rate passive mode-locked fibre ring laser with a semiconductor optical amplifier works like as a gain medium and non-linear polarisation rotation. A unidirectional erbium-doped fibre amplifier provides additional gain to increase cavity power. By exploiting non-linear polarisation rotation combined with dispersion management stable 5.18

A novel topology of the ac–dc power converter to supply neutral-point-clamped inverters used in ac motor drives and wind offshore power grids is proposed. It is based on the T-type multi-state switching cell, which allows obtaining a five-level voltage waveform downstream of the input filter inductor. The converter presents a high voltage gain due to the transformer secondary windings associated with

In this Letter, a demodulation based pre-filtering technique is proposed for fast detection of the single-phase grid variables. The estimation of grid voltage parameters is achieved through a Type-I synchronous reference frame phase-locked loop (PLL). The modified bandpass filter in the pre-filtering stage ensure a better rejection of the DC-offset and harmonics. Thus, the grid variables are estimated

Due to the sparse nature of inverse synthetic aperture radar (ISAR) images, sparsity-driven algorithms have been developed for high-resolution ISAR imaging. Recently, alternating direction method of multipliers (ADMMs) has been introduced for sparse signal recovery. In this Letter, based on ADMM, a fast algorithm for ISAR imaging is proposed which has lower computational complexity than that of conventional

With the development of the array signal processing techniques, more and more robust methods are proposed for non-stationary interference cancellation at the beamforming stage. Among these methods, null widening methods or well-known covariance matrix taper (CMT) methods are the research hotspots. However, the typical CMT-class methods modified the whole covariance matrix with the same taper matrix

This Letter demonstrates the technical capability of millimetre wave pulse-Doppler radar to identify safety-critical operating status information for parked cars. A simple 94-GHz pulsed linear frequency modulated radar with stretch processing on receive provides range-selective detection of small-scale vibration along the length of a parked car. The resulting range-Doppler signature clearly differentiates

When a small number of snapshots are used, the performance of the direction-of-arrival (DOA) estimation method based on the least squares (LS) degrades severely because of inadequate estimation of the covariance matrix. Although the subspace-based DOA estimation methods were proposed to improve the performance of DOA estimation method based on the LS; however these methods are computationally complex

Jitter and shimmer appear as symptoms of disordered voices and they are defined as the cycle-to-cycle variation of the cycle length and cycle amplitude, respectively. The frequency modulation of the phonatory excitation, i.e. vocal jitter, causes amplitude modulation (shimmer) of the speech signal due to the action of the vocal tract transfer function. In this Letter, the authors investigate the extent

In this Letter, a new construction of complementary sequence sets (CSSs) is proposed by concatenating Golay complementary pairs (GCPs) which could have different lengths. The constructed CSSs have flexible sequence lengths, i.e. , where L and N are the lengths of two constituting GCPs. For example, the proposed method can be used to construct quadriphase CSSs of all lengths up to 100, except 87 and

Semi-transparent wide-band coplanar waveguide slot antennas based on commercial indium tin oxide (CITO) and silver sandwiched indium tin oxide (AgITO) conductor thin films on soda-lime glass substrate are proposed. RF/DC sputtering was functionalised to deposit the AgITO and obtaining sheet resistance ( Rs ) below 1 Ω/Sq. coupled with ∼52% transparency. The associated three thin films (AgITO) deposition

In this Letter, a hierarchical conditional random field (HCRF) model-based gastric histopathology image segmentation (GHIS) method is proposed, which can localise abnormal (cancer) regions in gastric histopathology images to assist histopathologists in medical work. First, to obtain pixel-level segmentation information, the authors retrain a convolutional neural network (CNN) to build up their pixel-level

A background calibration technique for time-interleaved analogue-to-digital converter (TIADC) over Sub-Nyquist frequency timing mismatch is proposed. When the input signal only satisfies the Nyquist sampling theorem of the overall TIADC rather than sub-ADC, both directions of estimation based on correlation and compensation based on differentiator may be opposite to the actual value, which results

In this Letter, a general compensation method for finite parasitic output impedance of G m in G m -C lossless integrator is discussed. The use of a G m -simulated negative resistor in series with an integrating capacitor in a lossless integrator is shown to minimise the effects of the finite output impedance of G m -cell. The proposed method is employed in a second-order G m -C notch filter to improve

Aiming at the problem that the traditional prior information-based defogging algorithm fails in some special scenarios, an end-to-end convolutional defogging network based on attention mechanism is proposed. The network consists of two modules: parameter estimation and image restoration. First, multi-scale convolution is used to extract image feature information. Residual network and skip connection

The fusion of infrared and visible images has been playing an important role in various scenarios all over the world. For the fusion results from most of the existing techniques in this area, some features, such as the image contrast and edge details, are still needed to be improved. In this Letter, a new fusion method of the infrared and visible image is rendered. In this method, the infrared image

Recently, transformer has been applied to the image caption model, in which the convolutional neural network and the transformer encoder act as the image encoder of the model, and the transformer decoder acts as the decoder of the model. However, transformer may suffer from the interference of non-critical objects of a scene and meet with difficulty to fully capture image information due to its self-attention

This Letter reports a method to obtain fine-grained energy consumption analysis of programs running on the low-power internet of things (IoT) devices. In the energy estimation domain, most state-of-the-art solutions focus on the coarse-grained approach to monitor the energy consumption of a device or an application. However, few solutions addressed energy monitoring to analyse fine-grained energy consumption

This Letter presents a new second-order discrete map model, which is derived from a simple sampling switch-based memristor-capacitor circuit. The memristor-based map model has infinite unstable and critical stable fixed points, and exhibits chaotic and hyperchaotic behaviours via a period-doubling bifurcation scenario. These complex dynamical behaviours are confirmed by the phase portraits, iterative

In this Letter, performance of multiple users in downlink of non-orthogonal multiple access (NOMA) network considering the general shadowed fading model which was proposed in recent years is studied. In particular, main metrics including the outage probability, ergodic rate related to ordered channels are derived in novel and exact expressions for arbitrary values of the fading parameters. Moreover

A wideband filtering phase shifter is proposed using a cascaded single line and coupled line as a shunt stub of the centre-coupled line. Such kind of a shunt stub provides the possibility to achieve wideband impedance matching, wideband phase shift, and multiple controllable transmission zeros (TZs) at the same time. The coupling between the shunt stubs of the practical layout can generate extra TZs

A continuously tunable phase shifter based on a substrate integrated waveguide (SIW) is proposed for high-performance applications at millimetre-wave frequencies. The proposed phase shifter consists of two slots cut on the SIW's broad wall and a high dielectric constant (HDC) slab over the slots. The phase shifting mechanism is based on perturbing the electric field of the SIW-slot by putting a HDC

A broadband rectangular waveguide TE 10 –TE 20 mode converter with high mode purity and conversion efficiency is designed, fabricated and measured in this Letter. Based on the broadband characteristic of ridged twist waveguide and its characteristic of polarisation direction torsion of electromagnetic wave, this mode converter achieves broadband and high-efficiency TE 10 –TE 20 mode conversion. Simulation

A novel out-of-plane integration of multilayer strip-resonators is proposed. This kind of structure retains the merit of traditional in-plane integrated ones – simple and compact-sized, meanwhile, achieves the same amount of coupling with smaller horizontal space between resonators. Further miniaturisation of the previous bandpass filters (BPFs) can be realised by re-designing them based on the proposed

The authors present the implementation of two amplifiers in a commercial flexible amorphous Indium Gallium Zinc Oxide (a-IGZO) thin-film transistor (TFT) technology: a Cherry Hooper (CH) amplifier and a 4-stage common source amplifier. The CH amplifier is designed as a pre-amplifier for wireless receivers. It is optimised for a high gain-bandwidth product (GBW). From a supply voltage of V it provides

The lateral diffusion length ( L h ) of minority carriers in LWIR InAs/GaSb superlattice detectors grown by metalorganic chemical vapour deposition was evaluated. The deeply-etched PNn device exhibits a diffusion-limited behaviour at 80 K, with a dark current density as low as 9.1 × 10 −6 A/cm 2 at −0.1 V and a 50% cut-off of 10.1 μm. In shallow-etched pixels with a common absorber, both the photo-current

Herein, for the first time, the role of double-layer electron transporting layer (ETL), i.e. ZnO/SnO 2 on the efficiency of lead sulfide quantum dots solar cells is demonstrated. Using this approach, a device with power conversion efficiency of 10.6% is achieved mainly due to the enhancement of open circuit voltage ( V OC ). The authors reduce the loss-in-potential by 80 mV using ZnO/SnO 2 double-layer

A novel ultrathin barrier AlGaN/GaN hybrid-anode-diode (UTB-HAD) with in-situ Si 3 N 4 -cap passivation is experimentally demonstrated. The forward turn-on voltage ( V on ) of the UTB-HAD is determined by the intrinsic threshold voltage of the two-dimension electron gas (2DEG) channel, which can be precisely controlled by tailoring the as-grown AlGaN-barrier thickness. The typical V on as low as 0

Similarity measures play a significant role in adaptive filtering. Previous work such as correntropy and kernel risk-sensitive loss (KRSL), has successfully improved the technology of adaptive filtering in terms of robustness against outliers, fast convergence speed and high filtering accuracy. Based on KRSL, a newly raised similarity measure, complex KRSL (CKRSL), was proposed by extending KRSL to

In this Letter, the Logical Jaya optimisation is proposed as an extension of the Jaya optimisation algorithm to improve the cognitive workload (CW) assessment technique where channel selection for the EEG signal act as a binary optimisation problem. Channel selection is very crucial, time-consuming and requires expertise, specially when brain cognitive load is considered. The proposed approach is designed

The improvement of the ultra-wideband (UWB) biconical antenna directional characteristics at the upper part of the bandwidth by filling the aperture with the inhomogeneous dielectric lens is discussed in this Letter. The inhomogeneity of the filling was achieved by the complex three-dimensional configuration of the air gaps and the dielectric with constant permittivity. The distribution law of permittivity

Reliable rainfall rate complementary cumulative distributions are critical for the design of microwave communications systems operating above around 8 GHz. This Letter presents the results of the analysis of more than 5 years of 1-minute integrated rainfall accumulation data for 12 stations. This new dataset will prove useful considering the sharing analyses that must be executed for IMT services in

Electroencephalogram (EEG) signals are widely used in diagnosis of epilepsy. Accurate classification of seizure types based on EEG signals can provide vital information for diagnosis and treatment. Since visual inspection and interpretation of seizure types are time consuming and prone to errors, a novel classification method combining wavelet packet decomposition (WPD) and local detrended fluctuation

With the progression of picture archiving and communication systems (PACSs) over the past decade, it has become imperative that such systems be optimised in security, storage, and transmission aspects. The work presented in this Letter shows a framework for medical image compression and secure image transmission for PACSs. The work aims to achieve a lower dimensionality of input medical image signified

This Letter presents the implementation in a hardware device of the mean arterial pressure (MAP) response model of patients subjected to the infusion of the vasoconstrictor drug phenylephrine, enabling the development of automatic control systems in the future. The proposed model was firstly developed in a software platform with Simulink/MatLab using block libraries based on previous research carried

The author proposes an incremental windowing technique based on graph technique to detect hardware Trojan triggering signal. First, they analyse the switching activity file generated during simulation. Then, based on the window size of choice, they extract paths of n-HT (n-hardware Trojan; n is the number of triggering signals) and compare the path information with the HT instances from HT database

The magnetic field integral equation based method of moments (MoM) with the Kirchhoff approximation can predict the interior scattering from cavities with impedance boundary condition (IBC) walls. However, if the IBC wall is a small part of the whole wall and is modified multiple times, the conventional MoM may be time-consuming due to the repeated and expensive lower–upper (LU) decompositions of impedance

Discriminative correlation filters (DCFs) have recently achieved competitive performance in visual tracking benchmarks. However, such trackers perform poorly when the target undergoes occlusion, viewpoint variation or other challenging attributes. To tackle these issues, in this Letter, the authors combine the fast DCF trackers with the precise deep learning methods to eliminate the accumulating drift

Synthetic aperture radar (SAR) images can be utilised in various fields because they are not affected by the time of day or weather conditions. However, in the process of employing active sensors to obtain a SAR image, speckle noise is generated in the image. Speckle noise degrades the ability of computer vision to observe the Earth. To improve imaging performance, an algorithm for removing speckle

Generative models such as variational autoencoders (VAEs) and generative adversarial networks (GANs) have been recently applied to various fields. However, the VAE and GAN models have blur and mode collapse problems, respectively. Here, the authors propose a novel generative model, self-converging generative network (SCGN), to address the issues. Self-converging means the convergence of latent vectors

The term ‘collective’ is used to refer to a group of animals such as a flock of birds or a herd of elephants. Aggregate motions of such collectives often give rise to visually pleasing shapes and patterns (e.g. V-shape formation of geese while they migrate from one place to another). While shapes of moving collectives are of great interest in many scientific studies, scant attention has been given

This Letter proposes a novel state estimator called the visual odometry particle filter (VOPF) for improving accuracy of visual object trackers. For the VOPF, a novel visual odometry motion model that is better than the conventional constant velocity motion model is proposed. In addition, a new particle injection method to prevent sample impoverishment and the incorrect measurement detection method

An optimised low numerical dispersion unconditionally stable finite-difference time-domain (FDTD) method based on the isotropic dispersion (ID) scheme and weighted Laguerre polynomials (WLP) is presented. The proposed method adopts a scaling factor for permittivity and permeability in the ID-WLP-FDTD method, which can generate almost the exact phase velocity for a single frequency. In contrast with

In this Letter, the authors present a reconfigurable power divider using a hybrid matrix with variable impedance tuners. The proposed hybrid matrix-based power divider with varactor-tuned impedance tuners (VTITs) can simultaneously obtain variable power-dividing ratios at the centre frequency and variable operating frequencies for the 3 dB coupling states. The VTITs, consisting of a transmission line

The authors report quartz crystal microbalance (QCM) integrated with hexagonal boron nitride–graphene (hg) monolayer heterostructure as a sensor to detect mass flow of sulphur hexafluoride (SF 6 ), an important electrical insulating gas, under humid conditions. Their recent work demonstrated an enhancement in QCM sensing characteristics upon attaching monolayer 2D materials onto the QCM electrode surface

This Letter presents a novel RF ground lead structure for surface-mount-type optical modules that enables RF crosstalk reduction and bandwidth enhancements. Conventional RF lead-pins of a surface-mount-type optical module have a bent shape that affects on RF ground stability and RF crosstalk between channels. The authors introduced an enhanced ground lead with an optimised shape for RF ground scheme