Radar

Unmanned Aerial Vehicle (UAV) deployment has risen rapidly in recent years. They are now used in a wide range of applications, from critical safety-of-life scenarios like nuclear power plant surveillance to entertainment and hobby applications. While the popularity of drones has grown lately, the associated intentional and unintentional security threats require adequate consideration. Thus, there is an urgent need for real-time accurate detection and classification of drones. This article provides an overview of drone detection approaches, highlighting their benefits and limitations...

The potential of microwave Doppler radar in non-contact vital sign detection is significant; however, prevailing radar-based heart rate (HR) and heart rate variability (HRV) monitoring technologies often necessitate data lengths surpassing 10 s, leading to increased detection latency and inaccurate HRV estimates. To address this problem, this paper introduces a novel network integrating a frequency representation module and a residual in residual module for the precise estimation and tracking of HR from concise time series, followed by HRV monitoring...

PURPOSE: Cochlear implantation is a standard approach to hearing rehabilitation and encompasses three main stages: appropriate patient selection, a challenging surgical procedure, which should be as atraumatic as possible and preserve cochlear structures, and lifelong postoperative follow-up. Computed tomography (CT) is performed to assess postoperative implant position. The Siemens Advanced Radar Target Identification System (ARTIS) Pheno provides fluoroscopic imaging during surgery and has so far been mainly used by cardiologists, neurosurgeons and trauma surgeons...

Syndromic surveillance is an effective tool for enabling the timely detection of infectious disease outbreaks and facilitating the implementation of effective mitigation strategies by public health authorities. While various information sources are currently utilized to collect syndromic signal data for analysis, the aggregated measurement of cough, an important symptom for many illnesses, is not widely employed as a syndromic signal. With recent advancements in ubiquitous sensing technologies, it becomes feasible to continuously measure population-level cough incidence in a contactless, unobtrusive, and automated manner...

The development of stealth devices that are compatible with both infrared (IR) and radar systems remains a significant challenge, as the material properties required for effective IR and radar stealth are often contradictory. In this work, based on an IR electrochromic device (IR-ECD), concepts of metamaterial manipulating electromagnetic waves are applied to develop a multifunctional ultrathin metasurface with a low radar cross section (RCS) and variable infrared emissivity. This paper presents a linear-to-linear polarization conversion metasurface (PCM) designed by hollowing the IR-ECD...

OBJECTIVES: Our previous studies revealed the significant roles of FK506-binding protein 4 (FKBP4) in tumorigenesis, however, there has been no pan-cancer analysis of FKBP4. Using bioinformatics, the current study reported the expression and prognostic role of FKBP4, and the correlation between FKBP4 and clinicopathological parameters, methylation, molecular network, immunological traits and drug sensitivity. METHODS: RNA sequencing data, somatic mutation, and related clinical information were obtained from TCGA using UCSC Xena...

Fundamental data analysis assists in the evaluation of critical questions to discern essential facts and elicit formerly invisible evidence. In this article, we provide clarity into a subtle phenomenon observed in cancer incidences throughout the time of the COVID-19 pandemic. We analyzed the cancer incidence data from the American Cancer Society [1]. We partitioned the data into three groups: the pre-COVID-19 years (2017, 2018), during the COVID-19 years (2019, 2020, 2021), and the post-COVID-19 years (2022, 2023)...

INTRODUCTION: Remote monitoring technologies (RMTs) can measure cognitive and functional decline objectively at-home, and offer opportunities to measure passively and continuously, possibly improving sensitivity and reducing participant burden in clinical trials. However, there is skepticism that age and cognitive or functional impairment may render participants unable or unwilling to comply with complex RMT protocols. We therefore assessed the feasibility and usability of a complex RMT protocol in all syndromic stages of Alzheimer's disease and in healthy control participants...

The surge in urban development has resulted in a substantial accumulation of construction solid waste (CSW). However, prevailing identification methods of CSW need to be more efficient and remain predominantly two-dimensional in scope. This study employs an approach, combining simulation and experimental analyses, to delve into the factors influencing the electromagnetic scattering characteristics of CSW, investigating the feasibility of employing Synthetic Aperture Radar (SAR) to recognize CSW. The findings show that the computational time of MLFMM and PO is only 3...

In this paper, a wideband polarization conversion metasurface is designed. Additionally, coding and chessboard metasurfaces are specifically tailored for radar cross-section reduction (RCS). Initially, a compact unit cell demonstrating exceptional polarization conversion performance is introduced, achieving a polarization conversion ratio (PCR) exceeding 90 <mml:math xmlns:mml="https://www.w3.org/1998/Math/MathML"><mml:mo>%</mml:mo></mml:math> across frequencies ranging from 7.9 to 22...

This trial presents a laboratory model investigating the effect of quick returns (QRs, <11 h time off between shifts) on sleep and pre-sleep arousal. Using a crossover design, 63 participants worked a simulated QR condition (8 h time off between consecutive evening- and day shifts) and a day-day (DD) condition (16 h time off between consecutive day shifts). Participants slept at home and sleep was measured using a sleep diary and sleep radar. Compared to the DD condition, the QR condition reduced subjective and objective total sleep time by approximately one hour (both p < ...

The role of tropical forests in the global carbon budget remains controversial, as carbon emissions from deforestation are highly uncertain. This high uncertainty arises from the use of either fixed forest carbon stock density or maps generated from satellite-based optical reflectance with limited sensitivity to biomass to generate accurate estimates of emissions from deforestation. New space missions aiming to accurately map the carbon stock density rely on direct measurements of the spatial structures of forests using lidar and radar...

Wencheng waxy yam is famous for its glutinous and resilient taste, similar to waxy rice, but there is currently a lack of systematic research on the quality of this featured product, and little is known about its pesticide residues. We carried out a 2 year investigation of Wencheng waxy yam at seven sites from 2021 to 2022 to determine the oxidase content and phytochemical characteristics, namely, amylose, amylopectin, protein, reducing sugar, and mineral contents, such as K, Fe, and Zn, including the status of pesticide residues...

Polymer-based nanomotors are attracting increasing interest in the biomedical field due to their microscopic size and kinematic properties which support overcoming biological barriers, completing cellular uptake and targeted blasting in limited spaces. However, their applications are limited by the complex viscous physiological environment and lack of sufficient biocompatibility. This manuscript firstly reports a natural melanin nano-missile of MNP@HA-EDA@Urease@AIE PS (MHUA) based on photothermally accelerated urease-driven to achieve chemodrug-free phototherapy...

BACKGROUND Endometriosis is a common cause of chronic pelvic pain among women globally. Pharmacological therapy for endometriosis includes non-steroidal anti-inflammatory drugs (NSAIDs) and hormonal contraceptives, while surgical therapy often involves either laparoscopic excision and ablation of endometriosis implants or open surgery. Surgical therapy is one of the mainstays of treatment especially for extrapelvic endometriomas. However, little guidance exists for the treatment of non-palpable or intermittently palpable lesions of this nature...

Achieving radar-infrared compatible camouflage with dynamic adaptability has been a long-sought goal, but faces significant challenges owing to the limited dispersion relations of conventional material systems operating in different wavelength ranges. Here, we propose the concept of pneumatic multiscale shape morphing and design a periodically arranged pneumatic unit consisting of MXene-based morphable conductors and intake platforms. During gas actuation, the morphable conductor transforms centimeter-scale 2D flat sheets into 3D balloon shapes to enhance microwave absorption behavior, and also reconfigures micrometer-scale MXene wrinkles into smooth planes in combination with cavity-induced low heat transfer to minimize infrared (IR) signatures...

Conventional conductive materials such as metals are crucial functional components of conductive systems in diverse electronic instruments. However, their severe intrinsic impedance mismatch with the air dielectric causes strong reflection of the incident electromagnetic waves, and the resulting low electromagnetic transmissivity typically interferes with the surrounding electromagnetic signal communications in modern multifunction-integrated instruments. In this study, a graphene glass fiber fabric (GGFF) that merged the intrinsic electrical and electromagnetic properties of graphene with the dielectric attributes and highly porous macrostructure of a glass fiber fabric (GFF) was innovatively developed...

By using an external injection locking method, for what we believe to be the first time, we experimentally demonstrate continuous ultra-wideband signal regeneration in random optoelectronic oscillators, achieving more adaptable signal processing capabilities than self-oscillation methods. Supported by theoretical analysis and experimental evidences, this system can regenerate any signal with sufficient gain in a random-feedback cavity, independent of cavity filters. Remarkably, enhanced phase noise performance with over 35...

A closed-form model of bistatic multiphoton quantum radar cross section (QRCS) for the cylindrical surface, the main structure of typical aircraft, especially missiles, is established to analyze the system and scattering characteristics. The influence of curvature of the three-dimensional target on QRCS is analyzed. By comparing and analyzing the bistatic multiphoton QRCS for a cylinder and a rectangular plate, we find that the QRCS for the convex surface target is the extension of the QRCS for the planar target with inhomogeneous atomic arrangement intervals and patterns...

Laser-guided detector and infrared detection have attracted increasing attention in a wide range of research fields, including multispectral detection, radiative cooling, and thermal management. Previously reported absorbers presented shortcomings of lacking either tunability or compatibility. In this study, a metamaterial perfect absorber based on a Helmholtz resonator and fractal structure is proposed, which realizes tunable perfect absorptivity ( α 1.06 μ m >0.99, α 10.6 μ m >0...