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This article presents the possibility of controlling/managing the frequency selection ability of membrane-based broadband frequency sensors (MB2FS), exploiting systematic selection of membrane stiffness. MB2FS is a bio-inspired system mimicking the geometry and functionality of the basilar membrane (BM) in the mammalian cochlea. The actual BM is tapered in geometry (both length wise and thickness wise), which makes the stiffness of the membrane uniformly varied over its length. Because of varied stiffness, different locations of the BM show resonance deflection at different frequency inputs, which allow the BM to select/sense the entire sonic frequency band within its 35 mm length. While actual BM and conventional MB2FS possess homogeneous stiffness over the domain length, in this article, a comprehensive insight is provided of how the frequency selection ability of the sensors can be manipulated and controlled, predictively, using functionally graded structural stiffness. Therefore, this work is not intended to develop an artificial BM, rather is focused on developing frequency sensors inspired by the membrane stiffness of BM, which plays a vital role in the spatial selection of acoustic frequencies. The study is performed using a numerically validated predictive model developed in a semi-analytical interface to explain the effects of MB2FS stiffness variations. Based on biological occurrence of stiffness in natural BM, three functions (logarithmic, linear, and exponential) are assumed to predict the FSP. While a random sonic frequency band of 10–12 kHz is targeted in this study to demonstrate the stiffness grading principle of MB2FS, a similar process (e.g., choosing the appropriate stiffness distribution of the beam) can be used to develop both sonic and ultrasonic frequency sensors. This study presents a detailed framework of how the sensing parameters of a specific frequency band (e.g., sensing location of band start and end frequencies and membrane segment width necessary to sense the entire frequency band) are dependent on the function coefficients. Finally, a comprehensive guideline is provided to predictively determine the function coefficients for user-defined frequency selection parameters. While existing state-of-the-art only allows designing MB2FS for a specific frequency band, the work presented in this study will open the opportunity to select multiple frequency bands of an MB2FS without altering its geometric configuration. [ABSTRACT FROM AUTHOR]

Anomalous Hall effect (AHE) sensor has attracted significant attention in recent years due to its simpler structure and better sensitivity as compared to semiconductor-based Hall sensors. However, up to now, most of the work has been focused on its basic functionalities, with very little attention given to optimizing its performance for practical applications. In this work, we systematically investigated how the lateral dimension affects the performance of CoFeB-based AHE sensors. By adjusting the sensor width while keeping the length and other parameters constant, it is found that although the output signal amplitude decreases with increasing the sensor width, the noise and power consumption also decrease simultaneously, leading to an overall enhancement of the sensor performances with a sensitivity, detectivity, and power efficiency of 8960 Ω/T, 205 nT / Hz @ 1 Hz , and 2009 V/WT, respectively. To illustrate the potential applications of AHE sensors, we demonstrate a proof-of-concept experiment to showcase the potential AHE sensor in pulse detection. [ABSTRACT FROM AUTHOR]

Four types of barrier detectors based on a type II InAs/InAsSb superlattice with a wide-gap barrier made of a solid AlInAsSb lattice matched to the GaSb buffer were compared. The tested detectors differed in the type of doping of the active layer and the level and type of doping of the contact layer at the barrier. The epitaxial layers were deposited on GaAs (100) substrates using the molecular beam epitaxy method. The spectral and current–voltage characteristics of the analyzed detectors were compared. The highest current responsivities were observed in the structure with a p-type absorber (p+BpN+). Detectors with an n-type absorber (p+Bnn+, n+Bnn+, and nBnn+) show an increase in the current responsivity with an increase in the reverse bias voltage due to the reduction in the undesirable barrier in the valence band. Arrhenius characteristics for the dark current show that only in nBnn+ detectors, it was possible to limit the generation–recombination current. These detectors at 150 K were characterized by the highest normalized detectivity of approximately 3 × 1011 cm · Hz1/2/W. The obtained results were compared with literature data, showing that the parameters of type II superlattice photodetectors are close to those of HgCdTe photodiodes according to the "Rule 07" and "Rule 22" principles. [ABSTRACT FROM AUTHOR]

Transition-edge sensors (TESs) have the potential to perform electron spectroscopic measurements with far greater measurement rates and efficiencies than can be achieved using existing electron spectrometers. Existing spectrometers filter electrons by energy before detecting a narrow energy band at a time, discarding the vast majority of electrons available for measurement. In contrast, TESs have intrinsic energy sensitivity and so do not require prior filtering to perform energy-resolved measurements. Despite this fundamental advantage, TES electron spectroscopy has not, to our knowledge, previously been reported in the literature. We present the results of a set of proof-of-principle experiments demonstrating TES electron spectroscopy experiments using Mo/Au TESs repurposed for electron calorimetry. Using these detectors, we successfully measured the electron spectrum generated by an electron beam striking a graphite target with energies between 750 and 2000 eV, at a noise-limited energy resolution of 4 eV. Based on the findings of these experiments, we suggest improvements that could be made to TES design to enhance their electron detection capabilities through the use of a dedicated electron absorber in the device with integrated electron optics. [ABSTRACT FROM AUTHOR]

Dual-energy imaging represents a versatile and evolving technology with wide-ranging applications in medicine and beyond. Recent technological developments increased the potential for improved diagnostic accuracy and expanded imaging capabilities across various fields. The purpose of this work is to design and develop an energy-integrating multilayer detector, known as a sandwich detector, aimed at single-shot dual-energy imaging tasks such as material discrimination and contrast cancellation. The sandwich detector uses two complementary metal oxide semiconductor advanced pixel sensors of 50 μm pixel size. The top and bottom sensors detect low-energy (LE) and high-energy (HE) photons, with sensors coupled with 250 and 600 μm scintillators, respectively. For better spectral separation between layers without excessively affecting the detected statistic in the bottom layer, the insertion of a 0.25-mm Cu filter between the layers was found to be the optimal choice, from among the tested 0-, 0.25-, and 0.5-mm filter options. The thickness selection for scintillator and intermediate Cu filter was carried out through a dual-energy simulation model. The experiments confirmed the model's reliability in selecting the optimal thicknesses of the intermediate Cu filter, thereby providing reassurance also on the choice of the top scintillator. [ABSTRACT FROM AUTHOR]

Miniaturized photoionization detectors (PIDs) are used in conjunction with gas chromatography systems to detect volatile compounds in gases by collecting the current from the photoionized gas analytes. PIDs should be inexpensive and compatible with a wide range of analyte species. One such PID is based on the formation of a He plasma in a dielectric barrier discharge (DBD), which generates vacuum UV (VUV) photons from excited states of He to photoionize gas analytes. There are several design parameters that can be leveraged to increase the ionizing photon flux to gas analytes to increase the sensitivity of the PID. To that end, the methods to maximize the photon flux from a pulsed He plasma in a DBD-PID were investigated using a two-dimensional plasma hydrodynamics model. The ionizing photon flux originated from the resonance states of helium, He(3P) and He(21P), and from the dimer excimer He2*. While the photon flux from the resonant states was modulated over the voltage pulse, the photon flux from He2* persisted long after the voltage pulse passed. Several geometrical optimizations were investigated, such as using an array of pointed electrodes. However, increasing the capacitance of the dielectric enclosing the plasma chamber had the largest effect on increasing the VUV photon fluence to gas analytes. [ABSTRACT FROM AUTHOR]

In the semiconductor industry, virtual metrology (VM) is a cost-effective and efficient technique for monitoring the processes from one wafer to another. This technique is implemented by generating a predictive model that uses real-time data from equipment sensors in conjunction with measured wafer quality characteristics. Before establishing a prediction model for the VM system, appropriate selection of relevant input variables should be performed to maintain the efficiency of subsequent analyses considering the large dimensionality of the sensor data inputs. However, wafer production processes usually employ multiple sensors, which leads to cost escalations. Herein, we propose a variant of the sparse principal component analysis (PCA) called true sparse PCA (TSPCA). The proposed method uses a small number of input variables in the first few principal components. The main contribution of the proposed TSPCA is reducing the number of essential sensors. Our experimental results demonstrate that compared to the existing sparse PCA methods, the proposed approach can reduce the number of sensors required while explaining an approximately equivalent amount of variance. [ABSTRACT FROM AUTHOR]

A novel mode-localized acceleration sensor employing an electrostatically coupled resonator and integrating a lever with proof mass is micromachined using standard silicon on insulator (SOI) technology. In order to determine the linear dynamic range of the sensor, a reduced order model is developed while assuming that the resonators vibrate below the critical amplitude. Then, open-loop and closed-loop testing platforms are established to measure the performance of the linearly operating accelerometer in a vacuum environment (less than 5 Pa). Moreover, the corresponding amplifier circuit based on the capacitive detection principle is designed in order to extract and amplify the current signal from the resonators. The obtained results show that the accelerometer sensitivity can be increased by three orders of magnitude when using the relative shift of amplitude ratio as the output metric instead of the relative shift of frequency, and the experimental measurements are consistent with the theoretical predictions. Remarkably, the Allan standard deviation of the mode-localized acceleration sensor obtained from the closed-loop testing circuit is around 5.03 μg. [ABSTRACT FROM AUTHOR]

In this work, we studied the free-carrier transport properties and space-charge formation/polarization in a CdZnTe bar-shaped radiation detector using the Laser-Induced Transient Current technique. We found out that a steady-state space charge ranging from 8 × 108 to 2.1 × 109 cm−3 is formed throughout the detector at about 0.5 s following biasing. The measured current waveforms were modeled by Monte Carlo simulations after taking into account the electric and weighting fields inside the detector and shielding box. Modeling of the unpolarized waveforms revealed an exceptionally high electron mobility-lifetime product μ e τ e ≥ 0.095 c m 2 V − 1 . The observed formation of positive space charge in the biased detector and linear scaling of the current waveform shapes on applied bias revealed that the detector polarization is attributed to carrier injection at the anode. Measurements in pulsed and DC bias in modified electrode geometry proved the surface-charge formation. [ABSTRACT FROM AUTHOR]

Millimeter-thick methylammonium lead tribromide (MAPbBr3) single crystal x-ray detectors have recently raised attention due to their high x-ray attenuation efficiency and good charge transport properties. However, an intriguing feature of the photocurrent response of MAPbBr3 detectors has been largely overlooked in the literature. After biasing, transient sensitivity is measured under x rays at short-circuit (bias = 0 V), thus revealing a large remnant electric field that builds up under bias. Here, we exploit the x-ray sensitivity of MAPbBr3 detectors at zero-bias in order to probe the internal built-in field, as well as to investigate the charge transport properties of the perovskite material. Our model derived from the Hecht equation is able to fully rationalize the response of the detectors both at short-circuit and under moderate applied bias. Moreover, we provide a method for the estimation of the internal electric field, and for the sum of the electrons and holes mobility–lifetime products μ e τ e + μ h τ h. This general method could extend to any perovskite-based x-ray detector exhibiting transient sensitivity at zero-bias. [ABSTRACT FROM AUTHOR]

We propose and analyze the performance of terahertz (THz) room-temperature bolometric detectors based on the graphene channel field-effect transistors (GC-FET). These detectors comprise the gate barrier layer (BL) composed of the lateral hexagonal-boron nitride black-phosphorus/hexagonal-boron nitride (h-BN/b-P/h-BN) structure. The main part of the GC is encapsulated in h-BN, whereas a short section of the GC is sandwiched between the b-P gate BL and the h-BN bottom layer. The b-P gate BL serves as the window for the electron thermionic current from the GC. The electron mobility in the GC section encapsulated in h-BN can be fairly large. This might enable a strong resonant plasmonic response of the GC-FET detectors despite relatively lower electron mobility in the GC section covered by the b-P window BL. The narrow b-P window diminishes the Peltier cooling and enhances the detector performance. The proposed device structure and its operation principle promote elevated-temperature GC-FET THz detector responsivity values and other characteristics, especially at the plasmonic resonances. [ABSTRACT FROM AUTHOR]

Analytical instruments or scientific instruments are indispensable for scientific research and industry. The analytical instruments require a detector that converts physical quantities to be measured (measurands) to electric signals. This Tutorial describes the basics of quantum and thermal detectors, the operation principles of superconductor detectors, and the ultimate performance of state-of-art analytical instruments with superconductivity. We still face fundamental issues, such as the classical Fano factor, the relation between energy gap and mean carrier creation energy, quasiparticle dynamics, and the intermediate state in the middle of superconducting transition; and engineering issues, such as the small sensitive area and the spatially nonuniform response. Nevertheless, enormous efforts have matured superconductor detectors, which enables us to solve the inherent problems of conventional analytical instruments. As an example of the analytical results, we describe x-ray spectroscopy and mass spectrometry at our institute by using three detector types: superconductor tunnel junction, transition edge sensor, and superconductor strip. Microwave kinetic inductance and metallic magnetic calorimetric types are also described. The analytical results may contribute to a wide range of fields, such as dentistry, molecular biology, energy-saving society, planetary science, and prebiotic organic molecules in space. [ABSTRACT FROM AUTHOR]

Recent studies have provided conclusive evidence for the existence of a liquid–liquid critical point in numerical models of water. Such a scenario implies the competition between two local molecular arrangements of different densities: a high-density liquid (HDL) and a low-density liquid (LDL). Within this context, the development of accurate structural indicators to properly characterize the two interconverting local structures is demanded. In a previous study, we introduced a reliable energy-based structural descriptor that properly discriminates water molecules into tetrahedrally arranged molecules (T molecules) and distorted molecules (D molecules). The latter constitute defects in terms of hydrogen bond (HB) coordination and have been shown to represent a minority component, even at high temperatures above the melting point. In addition, the D molecules tend to form high-quality HBs with three T molecules and to be surrounded by T and D molecules at further distances. Thus, it became evident that, while the LDL state might consist of a virtually pure T state, the HDL state would comprise mixed molecular arrangements including the D molecules. Such a need to abandon the single-molecule description requires the investigation of the degree of structural information to be incorporated in order to build an appropriate multi-molecule indicator. Hence, in this work, we shall study the effect of the local structural constraints on the water molecules in order to discriminate the different molecular arrangements into two disjoint classes. This will enable us to build a multi-molecule structural indicator for water whose performance will then be investigated within the water's supercooled regime. [ABSTRACT FROM AUTHOR]

Sensor limitations in capturing devices and environmental factors can result in radiance artifacts in rendered images. This paper presents an entropy-driven exposure interpolation framework in the context of large exposure-ratio fusion. The proposed framework generates intermediate exposure-corrected images through transmission map estimation to obtain initial radiance and illumination maps. Fusion weight maps, within a pyramidal framework, are derived from the transmission map and spatial entropy, thereby enhancing the visual quality of images while preventing color artifacts. Experiments demonstrate that the proposed framework outperforms several state-of-the-art multi-exposure fusion schemes. [ABSTRACT FROM AUTHOR]

Summary: It is well known that hardware impairments (HWIs) can worthy reduce the wireless system performance at high carrier frequencies by showing random effects. Most current researches for 5 GB systems assume that transmitters and receivers (transceivers) are perfectly equipped. But wireless transceivers (TxRx) are affected by HWIs in practice. Considering the previous studies in the literature, it is reported that HWIs have devastating effects on the performance of OFDM and OFDM‐index modulation (IM) systems with fading channels. In this paper, in‐phase and quadrature phase imbalance (IQI), which is the one of most HWIs between transmitter and receiver in wireless communication systems, is examined on OFDM‐IM system over Rayleigh and Nakagami‐ m fading channels. Two well‐known detectors, the maximum likelihood (ML) detector and the log‐likelihood ratio (LLR) detector are used under the effect of the IQI at TxRx. Error performance analyzes over fading channels of the IQI effect on OFDM‐IM system are realized first theoretically and then by computer simulations. Results obtained for the presence of IQI at TxRx show that a performance evaluation based only on the presence of IQI in the receiver would be optimistic and misleading in terms of the performance of real‐life OFDM‐IM systems. [ABSTRACT FROM AUTHOR]

The event‐triggered extended dissipativity control problem for semi‐Markov jump systems (SMJSs) on the basis of multiple types of deception attacks is discussed in this paper. The mode‐ and disturbance‐dependent event‐triggered mechanism (ETM), unlike the traditional ETM, is designed to identify the triggered moments which can prevent network resources from being wasted. Additionally, as the attack evolves into a more intelligent and complex strategy, It is hypothesized that there are multiple deception attacks that can be applied to the communication channels between the sensor and the controller, which are modeled by a more general semi‐Markov process (SMP). As a result, by using stochastic analysis techniques and system‐mode‐dependent and attack‐mode‐dependent Lyapunov‐Krasovskii functional (LKF), a new sufficient condition is established to guarantee the stochastic stability and extended dissipativity of the closed‐loop SMJSs. Four numerical cases are given to illustrate the effectiveness of the developed method. [ABSTRACT FROM AUTHOR]

For Deepfake detection, many existing works use the cross-entropy loss to enforce the classifier network to learn the mapping relationship from the RGB domain to the class domain, lacking an explicit constraint to guide the feature extraction network to learn discriminative features from an input image. This constrains the feature representation capability to expose deepfake. In this work, we analyze the feature extraction network in terms of both difference and similarity capabilities and propose a new constraint called similarity loss (SL) to improve the detection performance of the convolutional neural network (CNN) based detector. Moreover, according to the experimental results of the SL on data augmentation effectiveness, we propose a simple yet efficient framework, which is called as efficient similarity representation learning (ESRL), for deepfake detection. Extensive experiments on three public datasets (namely FF++, DFDC, and Celeb-DF) show that the feature extraction network trained with the help of SL can map forged faces and real faces to different feature embedding and map the same type of forged faces to similar feature embedding. [ABSTRACT FROM AUTHOR]

Semi-supervised object detection aims to enhance object detectors by utilizing a large number of unlabeled images, which has gained increasing attention in natural scenes. However, when these methods are directly applied to scenes with tiny objects, they face the challenge of selecting pseudo-labels with high localization quality due to the minuscule and blurred characteristics of these objects. To address this issue, we propose a novel method called semi-supervised tiny object detection (STOD). Firstly, to enhance the localization accuracy of pseudo-labels, we design a dense IoU-aware head that evaluates the quality of bounding box localization by incorporating additional predicted overlap values. Secondly, to mine more potential pseudo-labels, we propose a GMM-based multi-threshold pseudo-labels mining module that dynamically generates multiple thresholds using classification scores and overlap values to classify bounding boxes into strong positive and weak positive pseudo-labels. Lastly, we design the localization-aware weighting loss to incorporate the localization quality of both positive and negative samples in order to enhance the accuracy of pseudo-label localization. The experimental results show that STOD achieves comparable performance when compared to both fully and semi-supervised methods. Notably, on the VisDrone-Partial benchmark, STOD achieves outstanding results by outperforming our baseline model with improvements of 3.1 mAP, 5.7 A P 50 , and 3.0 A P 75 . [ABSTRACT FROM AUTHOR]

Real-time monitoring of structural health status is very important for supersonic aircraft, since the long-term operation in harsh service environments, such as high temperatures, can cause potential damage. Structural health monitoring (SHM) based on lamb wave has been approved to be a critical technique for the reliable operation of supersonic aircraft, but is limited by the operating temperature of conventional piezoelectric sensors, which makes it difficult to meet the high-temperature monitoring requirements. The BiFeO 3 –BaTiO 3 ceramics exhibit excellent piezoelectric properties and high Curie temperature (T c), making them promising for high-temperature SHM of supersonic aircraft. Here, we fabricated a piezoelectric sensor using 0.67BiFeO 3 -0.33BaTiO 3 -0.25%molMnO 2 (BF33BTMN-025) ceramic, which exhibits a piezoelectric charge constant (d 33) of 135 pC/N at room temperature and a T c of 448 °C. The BF33BTMN-025 ceramic sensor operates effectively at temperatures up to 200 °C and maintains stable damage monitoring sensitivity as well. Compared with Pb(Zr, Ti)O 3 (PZT), BaTiO 3 (BTO) and other piezoelectric sensors commonly used in SHM field, the BF33BTMN-025 ceramic sensor has a higher operating temperature and a comparable sensitivity. Our work demonstrates that the BF33BTMN-025 ceramic sensor can be employed as piezoelectric sensor for high-temperature SHM, which has a wide application potential in the field of real-time monitoring of supersonic aircraft. [ABSTRACT FROM AUTHOR]

For the on-line stable detection of TEA, mixed potential gas sensor based on GDC (gadolinium doped cerium oxide, Ce 0.8 Gd 0.2 O 1.95) solid electrolyte and MFe 2 O 4 (M = Ni, Cu, Zn) sensing electrode has been fabricated in this work. The influence of element type and sintering temperature of the sensing materials on the sensing performance were mainly discussed, the sensor manufactured with CuFe 2 O 4 sintered at 800 °C generates the highest response (−50.7 mV) to 20 ppm TEA compared with other sensors. The response value changed proportionally with the logarithm of TEA concentration, with the sensitivity of −21.9 and −43.6 mV/decade in the range of 0.5–5 and 5–100 ppm, respectively. The sensor exhibited excellent repeatability towards 2 and 10 ppm TEA for 7 continuous tests, and great selectivity for 10 various gases. Moreover, the sensor also demonstrated good moisture resistance and terrific long-term stability at 500 °C for 30 days continuous work. Based on the excellent sensing properties, this work supplied a stable TEA sensor fabricated with CuFe 2 O 4 sintered at 800 °C, which has a great potential application prospect for the accurate detection towards TEA. [Display omitted] [ABSTRACT FROM AUTHOR]

A hot spot which is a glowing orange local area appears in RE Ba 2 Cu 3 O y (RE : rare earth) ceramic rods when a voltage higher than a certain value is applied at room temperature. After the hot spot appears, the oxygen partial pressure in the ambient atmosphere changes the current through the rod, which can be used as an oxygen sensor without the need for a heating system. In this study, the authors investigated the oxygen-sensing characteristics and the power-saving effect of the sandwich structure in which the sensor layer was stacked between insulation layers. The sample rods were prepared by the solid-state reaction at 960 °C. Materials of 5 mol% Nd 2 BaCuO 5 -added Nd 1.4 Ba 1.6 Cu 3 O y and 20 mol% Nd 1.4 Ba 1.6 Cu 3 O y -added Nd 2 BaCuO 5 were used for the sensor layer and the insulation layer, respectively. The sensitivity to the oxygen increased with increasing voltage applied to the rod. Under the condition where 17.8 V was applied to the rod with the sandwich structure and 6.6 V to the rod with the monolithic structure, the sensitivities of both rods were almost the same. The sandwich structure had a reduced current value and consumed approximately 26 % less power than the monolithic structure. The response time for the sandwich structure and the monolithic structure were comparable, meaning that the insulation layer did not impair the response time. [ABSTRACT FROM AUTHOR]

In the domain of object detection, the performance of a detector depend heavily on the quality of features extracted by the backbone network. Extraordinary feature representation has significantly improved the performance of the detector. As we all know, proposing a novel backbone structure requires meticulous structural design, a wealth of expert experience and tricks, and consumes a lot of computing resources. Therefore, it is meaningful to effectively leveraging the existing pre-trained backbones and maximize their performance to improve the accuracy of object detection. In this paper, we propose a novel Feature-enhanced Composite Backbone Network to improve the feature representation capability of the backbone, which called FECNet, equipped with Proportional Feature Fusion Module(PFF) and Multi-Granularity Information Aggregation and Interaction Method(MIAM). In particular, FECNet combines the existing backbones, which are connected by PFF, and FECNet pays more attention to extracting the discriminative features related to the object that are suitable for classification and the edge information suitable for bounding box regression through MIAM. Experiments show that FECNet is easily integrated into mainstream detectors and improve their performances. On the COCO 2017 dataset, employing ResNet50 as the foundational backbone, our approach attains a notable 3 percent increment in performance within the Fast R-CNN framework. Simultaneously, our method yields 2.1 percent enhancement when applied to the ResNet101 + Cascade R-CNN. And it's worth noting that applying our approach on the backbone swin transformer which is based on the trasformer structure gets an increase of more than 2 percent. [ABSTRACT FROM AUTHOR]

Microimage strain sensing (MISS) is a novel piston‐type sensor based on microscopic vision. In this study, optical disc slice is used as information carriers to improve MISS. There are multiple pits on the surface of an optical disc. By using machine vision algorithms, the pits can be converted into digital information, making them scales for recording displacements. By this means, we proposed a sensing method that combines high resolution, wide range, and strong robustness. The study measured displacement under different conditions. To address inevitable factors such as pixel drift, and manufacturing errors, corresponding compensation methods were provided. The results show that the measurements closely match those of the linear variable differential transformer, with a resolution of up to 20 nm and a range approaching the sensor size. Despite the sensor's dependence on machine vision, it demonstrates strong resistance to environmental factors such as brightness and angle. Combining compensation methods for pixel drift, and manufacturing errors, this sensor can be well‐applied in various working conditions. [ABSTRACT FROM AUTHOR]

Object detectors are used for searching all objects belonging to a pre-defined set of categories contained in a given picture. However, users are often not interested in finding all objects, but only those that pertain to a small set of categories or concepts. Nowadays, the standard approach to solve this task involves initially employing an object detector to identify all objects within the image, followed by refining the outcomes to retain only the ones of interest. Nevertheless, the object detector does not take advantage of the user's prior intent that, when used, can potentially improve the detection performance of the model. This work presents a method to condition an existing object detector with the user's intent, encoded as one or more concepts from the WordNet graph, to find just those objects of interest. The proposed approach takes advantage of existing datasets for object detection without the need for new annotations, and it allows to adapt the already existing object detector models with minor changes. The evaluation, performed on the COCO and the Visual Genome datasets considering several object detector architectures, shows that conditioning the search on concepts is actually beneficial. The code and the pre-trained model weights are released at: https://github.com/drigoni/Concept-Conditioned-Object-Detector. [ABSTRACT FROM AUTHOR]

This paper addresses the issue of actuator and sensor faults causing instability in leaderless/follower multi‐agent systems (MASs) and investigates adaptive fault‐tolerant control (FTC) algorithms to secure stability. Sensor faults can disrupt conventional observers by interfering with system state measurements. To address this issue, the descriptor approach is introduced to construct an augmented system from the original system, which converts the faults into components of the augmented system state. Next, by utilizing a sliding‐mode term to compensate for the lumped uncertainty's impact, an observer is designed to realize state estimation for the augmented system. Then, based on the estimations, adaptive FTC protocols are investigated for leaderless/leader‐follower MASs to retain stability against concurrent faults and uncertainties. To enhance control efficiency, the control gains are updated with the estimations from neighbors and proved to be ultimately upper bounded. Finally, the proposed method is validated through numerical simulations of multiple quadrotors. [ABSTRACT FROM AUTHOR]

Electrochemical sensors provide an affordable and reliable approach towards the detection and monitoring of important biological species ranging from simple ions to complex biomolecules. The ability to miniaturize electrochemical sensors, coupled with their affordability and simple equipment requirements for signal readout, permits the use of these sensors at the point-of-care where analysis using non-invasively obtainable biofluids is receiving growing interest by the research community. This paper describes the design, fabrication, and integration of a 3D printed Mg2+ potentiometric sensor into a 3D printed microfluidic device for the quantification of Mg2+ in low-sample volume biological fluids. The sensor employs a functionalized 3D printable photocurable methacrylate-based ion-selective membrane affixed to a carbon-mesh/epoxy solid-contact transducer for the selective determination of Mg2+ in sweat, saliva and urine. The 3D printed Mg2+ ion-selective electrode (3Dp-Mg2+-ISE) provided a Nernstian response of 27.5 mV per decade with a linear range of 10 mM to 39 μM, covering the normal physiological and clinically relevant levels of Mg2+ in biofluids. 3Dp-Mg2+-ISEs selectively measure Mg2+ over other biologically present cations – sodium, potassium, calcium, ammonium – as well as provide high stability in the analytical signal with a drift of just 13 μV h−1 over 10 hours. Comparison with poly(vinylchloride)-based Mg2+-ISEs showed distinct advantages to the use of 3Dp-Mg2+-ISEs, with respect to stability, resilience towards biofouling and importantly providing a streamlined and rapid approach towards mass production of selective and reliable sensors. The miniaturization capabilities of 3D printing coupled with the benefits of microfluidic analysis (i.e., low sample volumes, minimal reagent consumption, automation of multiple assays, etc.), provides exciting opportunities for the realization of the next-generation of point-of-care diagnostic devices. [ABSTRACT FROM AUTHOR]

In this study, we developed an isothermal fluorometric diagnostic method for DNA virus-generating disorders such as Mpox. Our results showed that the release of a large number of protons during multiplex-LAMP markedly lowered the pH level, which transformed the retinoblastoma (Rb) linear ssDNA into i-motifs. Consequently, thiazole orange (TO; a fluorometric probe sensitive to the i-motif) boosted the signal-on fluorescence because of its ability to bind selectively to i-motifs. This multiplex-LAMP/i-motif-TO system enabled simultaneous detection aimed at numerous potential targets with remarkable sensitivity (1.47 pg per mL) and efficiency (30 minutes). Our method is expected to enable DNA-virus-related diseases to be efficiently and accurately assessed. [ABSTRACT FROM AUTHOR]

To ensure the accuracy of radiation delivery to patients in a 1.5 T MRI-linac, the implementation of quality assurance (QA) devices compatible with MR technology is essential. The OCTAVIUS 4D MR, made by PTW (Freiburg, Germany) is designed to ensure consistent and ideal alignment of its detectors with the direction of each beam segment. This study focuses on investigating the fundamental characteristics of the detector response for the OCTAVIUS Detector (OD) 1500 MR and OCTAVIUS 1600 MR when used in the MR-compatible OCTAVIUS 4D. Characteristics examined included short-term reproducibility, dose linearity, field size dependency, monitor unit (MU) rate dependency, dose-per-pulse dependency, and angular dependency. The evaluation of OD 1500 MR also involved measuring 25 clinical treatment plans across diverse target sizes and anatomical sites, including the liver/pancreas, rectum, prostate, lungs, and lymph nodes. One plan was measured with the standard setup and with a 5 cm left offset. The OD 1600 MR was not available for these measurements. The capability of the OD 1500 MR to identify potential errors was assessed by introducing a MU and positional shift within the software. The results demonstrated no significant differences in short-term reproducibility ( < 0.2 % ), dose linearity ( < 1 % ), field size dependency ( < 0.7 % for field sizes larger than 5 cm × 5 cm), MU rate dependency ( < 0.8 % ), dose-per-pulse dependency ( < 0.4 % ) and angular dependency (standard deviation < 0.5 % ). All tests of clinical plans were successfully completed. The OD 1500 MR demonstrated compatibility with the standard 95% pass rate when employing a global 3%/3 mm gamma criterion, and a 90% pass rate using a global 2%/2 mm gamma criterion. The detector demonstrated the capacity to measure treatment plans with a 5 cm left offset. With the standard parameters, the gamma test was sensitive to position errors but required an addition tests of mean/median dose or point dose in order to detect small dose difference. [ABSTRACT FROM AUTHOR]

The sensor that simultaneously perceives bending strain and magnetic field has the potential to detect the finger bending state and hand position of the human and robot. Based on unique magneto-mechanical coupling effect of magnetostrictive materials, the proposed a bi-perceptive flexible sensor, consisting of the Co–Fe film and magnetic sensing plane coils, can realize dual information perception of strain/magnetic field through the change of magnetization state. The sensor structure and interface circuit of the sensing system are designed to provide high sensitivity and fast response, based on the input–output characteristics of the simulation model. An asynchronous multi-task deep learning method is proposed, which takes the output of the position task as the partial input of the bending state task to analyze the output information of the sensor quickly and accurately. The sensing system, integrating with the proposed model, can better predict the bending state and approach distance of human or robot hand. [ABSTRACT FROM AUTHOR]

In this article, a reflector back ultra-wide band (UWB), circularly polarized (CP) antenna is presented using asymmetric circularly curved radiating elements. The circular aperture on the reflector plane is connected with the radiating plane using two shorting pins to maintain the impedance bandwidth and axial ratio (AR) bandwidth. In addition to the frequency domain, time domain performances are investigated to understand the receiving signal quality, considering the pulse spreading effects. The received signal quality is quantified for near field (NF) and far field (FF) with the parameter system fidelity factor (SFF). It is observed that the SFF becomes stable and less dispersive from the minimum distance 75 mm from the antenna at near field. The measurement result also shows that the proposed antenna can provide maximum 10.2 dBic peak gain, $ 78.9\% $ 78.9% of impedance bandwidth and $ 82.3\% $ 82.3% of axial ratio bandwidth with system fidelity factor (SFF) of 0.95 and 0.97 for NF and FF respectively. In addition to this, the variation of group delay is within 1.3 ns for NF and FF cases. [ABSTRACT FROM AUTHOR]

Bound states in the continuum (BICs) are an excellent platform enabling highly efficient light–matter interaction in applications for lasing, nonlinear generation, and sensing. However, the current focus in implementing BICs has primarily been on single sharp resonances, limiting the extent of electric field enhancement for multiple resonances. In this study, experimental demonstrations are conducted to showcase how metasurfaces can enable the control of symmetry‐broken and Friedrich–Wintgen BICs by leveraging the asymmetry of split resonant rings. This approach allows for the existence of multiple free‐control BIC resonances and tailored enhancement of controlling light–matter interactions. Further experiments are conducted to validate the effectiveness and performance of meta‐sensors for the identification of the distinct fingerprint of α‐lactose with high sensitivity using only one single metasurface. These findings present a novel and efficient platform for the development of miniaturized and chip‐scale photonics devices with intense light–matter interaction. [ABSTRACT FROM AUTHOR]

We answer frequently asked questions (FAQs) about the Hellings and Downs correlation curve—the 'smoking-gun' signature that pulsar timing arrays (PTAs) have detected gravitational waves (GWs). Many of these questions arise from inadvertently applying intuition about the effects of GWs on LIGO-like detectors to the case of pulsar timing, where not all of it applies. This is because Earth-based detectors, like LIGO and Virgo, have arms that are short (km scale) compared to the wavelengths of the GWs that they detect ( ≈ 10 2 –104 km). In contrast, PTAs respond to GWs whose wavelengths (tens of light-years) are much shorter than their arms (a typical PTA pulsar is hundreds to thousands of light-years from Earth). To demonstrate this, we calculate the time delay induced by a passing GW along an Earth-pulsar baseline (a 'one-arm, one-way' detector) and compare it in the 'short-arm' (LIGO-like) and 'long-arm' (PTA) limits. This provides qualitative and quantitative answers to many questions about the Hellings and Downs curve. The resulting FAQ sheet should help in understanding the 'evidence for GWs' recently announced by several PTA collaborations. [ABSTRACT FROM AUTHOR]

3D printing has revolutionised the design and manufacturing of high-temperature thin/thick-film sensors (TFSs). However, existing printable high-temperature materials face cost-performance trade-offs. This study proposes a silicate and RuO 2 composite for the 3D printing of TFSs. A silicate compound (SiO 2 –Al 2 O 3 –CaO, SAC) was used as a sintering aid to reduce the sintering temperature of RuO 2 , forming a silicate glass phase that enhanced film density and substrate adhesion. The SAC also minimised RuO 2 particle volatilisation at high temperatures, thus enhancing the stability of the SAC/RuO 2 composite. The SAC/RuO 2 TFSs demonstrated exceptional performance, with a positive temperature coefficient (502 ppm/°C) from room temperature to 800 °C, high linearity, and stability (resistance drift rate of 0.1 %/h at 800 °C), extending the application temperature of RuO 2 by nearly 200 °C from the previous application temperature of 600 °C. Therefore, the SAC/RuO2 composite offers a new low-cost and high-performance solution for using 3D printing technology in harsh environmental sensors such as turbine blades. [ABSTRACT FROM AUTHOR]

A highly sensitive and repeatable humidity sensor that can measure relative humidity at room temperature (25 °C) was fabricated using activated carbon-ZnO (AC/ZnO) nanocomposites. The AC/ZnO nanocomposites with high oxygen vacancies were prepared by a facile one-pot synthesis method through carbonization of ZnCl 2 -impregnated biomass precursor. The sensor exhibited a better response (96 % at 0.5 V biasing), short response time (17.4 s), and recovery time (32.1 s). The same 96 % relative response at 0.5V biasing for all four consecutive cycles was observed without losing the response-recovery time, indicating excellent repeatability. On the other hand, biomass-derived single-phase activated carbon (AC) did not respond to humidity change at room temperature. The improved humidity sensing in AC/ZnO nanocomposites was ascribed to the synergistic effects of increased oxygen vacancies, increased active sites in the AC phase, and the formation of p–n heterojunction at the composite interface, substantiated with X-ray diffraction (XRD), Raman and X-ray photoelectron spectroscopy (XPS) studies. The sensing mechanism of AC/ZnO nanocomposite was discussed based on the enhanced reduction of H 2 O by adsorbed O 2 − at AC/ZnO heterojunction, leading to increasing sensor resistance. [Display omitted] [ABSTRACT FROM AUTHOR]

Quantum sensors find applications ranging from material science to biophysics. Nitrogen‐vacancy (NV) center in diamond has been successfully implemented for measuring various types of signals. Optical NV center readout, routinely used in confocal microscopes, allows achieving high spatial resolution down to the diffraction limit. This work describes in detail the combined confocal‐atomic‐force microscope (confocal‐AFM), which takes advantage of sharp AFM cantilevers, and shows its possible applications for nanoscale resolution. It demonstrates the sub‐diffractional localization of NV centers with platinum‐coated cantilevers and the ability to separately address optically unresolved sensors using cantilevers with ferromagnetic coating. The presented setup exhibits a lateral resolution of 13 nm, providing a tool for nanoscale quantum sensing. [ABSTRACT FROM AUTHOR]

Spiral phase contrast imaging alleviates the information load by extracting the geometric features of objects and is one of the most representative branches of instant imaging processing. The self-healing capacity of edge detectors can enhance their robustness to obstacles in practical applications. Here, a self-healing spiral phase contrast imaging scheme is proposed and experimentally demonstrated by a liquid crystal edge detector combining a spiral phase, an axicon phase, and a lens phase. The spiral phase is encoded into a liquid crystal by photopatterning. Self-healing contrast imaging is characterized by a series of edge images of both high-contrast amplitude-type and low-contrast phase-type objects. This work extends the self-healing capacity of these detectors to instant imaging processing and paves the way for optical applications with self-healing features. [ABSTRACT FROM AUTHOR]

Herein, we have developed a non-enzymatic, isothermal amplification assay (NIA sensor) based on a catalytic hairpin assembly (CHA) reaction for quantifying the relative abundance of Akkermansia muciniphila. Through detection of the MUC-1437 gene (limit of detection: 8.3 fM) in a dynamic range from 10 fM to 1 nM, the NIA sensor shows high sensitivity and selectivity in preclinical models of mice fed a normal or high-fat diet (HFD), and treated with antibiotics (ATB). The NIA sensor, which operates without the use of any enzymes, leading to simplicity and cost-effectiveness, has great potential for biosensing research and clinical diagnostic applications. [ABSTRACT FROM AUTHOR]

Multimodal tactile sensors, as key information input channel in human‐machine interactions, have faced the significant challenges including high power‐consumption, multimodal data fusion, and wireless transmission. In this work, a battery‐free multimodal wireless tactile sensor (TC‐MWTS) based on tribo‐capacitive coupled effect for normal and shear force fusion sensing is proposed, which is enabled by a 3D structure combining a triboelectric sensor and a capacitive sensor coupled with an inductive coil. A triboelectric sensor equipped with contact‐discharge structures exhibits 25‐fold wireless signal enhancement compared to conventional triboelectric sensors. Based on the characteristics of dual time‐frequency domain information existing in the wireless signals, both normal and shear forces can simultaneously be converted into voltage amplitude V and eigenfrequency f, respectively, without crosstalk and complex decoupling signals. The TC‐MWTS exhibits a maximum sensitivity of 2.47 V kPa−1 for normal force from 2 to 30 kPa and a sensitivity of 0.28 MHz N−1 for shear force between 0.3 and 1.0 N. Finally, the excellent sensing capability of TC‐MWTS to sense complex multidimensional forces in human‐machine interaction is demonstrated. This work innovatively proposes a new mechanism and methodology for effectively fusing and processing multimodal tactile information, which may drive the tremendous development of low‐power multimodal tactile sensing system. [ABSTRACT FROM AUTHOR]

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