A newly emerged coronavirus (COVID-19) seriously threatens human life and health worldwide. In coping fighting against COVID-19, the most critical step is to effectively screen diagnose infected patients. Among them, chest X-ray imaging technology a valuable diagnosis method. The use of computer-aided images COVID-19 cases can provide experts with auxiliary suggestions, which reduce burden certain extent. this study, we first used conventional transfer learning methods, using five...

It is well known that the handwritten Chinese text recognition a difficult problem since there are large number of classes. In order to solve this problem, we proposed whole new framework for unconstrained recognition. The core module heterogeneous CNN trained by deep knowledge. experimental results showed our method could achieve much better performance than state-of-the-art methods (96.28% vs. 91.39% CR on CASIA test set). Moreover, general, it can also be applied other time sequence...

Most of toolpaths for machining is composed series short linear segments (G01 command), which limits the feedrate and quality. To generate a smooth path, new optimization strategy proposed to optimize toolpath at curvature level. First, three essential components are introduced, local corner smoothness converted into an problem. The challenge then resolved by intelligent algorithm. Considering influence population size computational resources on algorithms, deep learning algorithm (the...

A high-performance data acquisition and processing system within a spectrometer provides powerful guarantee for obtaining high-precision in ground-based Fourier-transform infrared greenhouse-gas spectroscopy. Addressing the challenge of accurate interferogram sampling spectroscopy, dual-channel method was designed. Dual-channel analog-to-digital converters, acquiring interferograms at different gains, enable high dynamic range high-resolution interferometric signals; converter channel...

The impedance tube method, particularly the two-microphone is widely employed for measuring normal acoustic parameters. However, this method constrained by assumption of plane wave, leading to limitations on effective frequency range. To resolve limitations, paper proposes a data-driven capable accurately predicting sound absorption coefficient using only two microphones in multi-modal field. First, proposed integrates neural network model with transfer relationship tube, and generates large...

Aero-optic imaging deviation is a kind of aero-optic effect. It characterizes the image position displacement on an plane. This paper studies influence altitude deviation. The Reynolds-averaged Navier–Stokes solver provided in FLUENT was used for flow computations. Runge–Kutta method based ray tracing adopted optics calculations. orthogonal array brought experiment arrangement. Four representative suites deviations and slopes were obtained range 10–60 km. results show that as increases,...

RGB-Infrared (IR) person re-identification is very challenging due to the large cross-modality variations between RGB and IR images. The key solution learn aligned features bridge modalities. However, lack of correspondence labels every pair images, most methods try alleviate with set-level alignment by reducing distance entire sets. this may lead misalignment some instances, which limits performance for RGB-IR Re-ID. Different from existing methods, in paper, we propose generate...

Transient nearfield acoustic holography based on an interpolated time-domain equivalent source method (ESM) is proposed to reconstruct transient fields directly in the time domain. Since strengths solved by traditional ESM formulation cannot be used pressure surface directly, interpolation function introduced develop which permits one deduce iterative reconstruction process. As process ill-conditioned and especially there exists a cumulative effect of errors, Tikhonov regularization...

A backward ray-tracing method is proposed for aero-optics simulation. Different from forward tracing, the tracing direction internal sensor to distant target. Along this direction, in turn goes through gas region, flow field, and freestream. The coordinate value, density, refractive index are calculated at each step. stopping criterion developed ensure stops outer edge of field. As a demonstration, analysis carried out typical blunt nosed vehicle. greatly simplify computations they can be...

In order to overcome the shortcomings of traditional back propagation (BP) and single genetic algorithm (GA), a method based on quantum GA (QGA) is proposed optimize BP neural network for fault detection liquid rocket engines. this QGA-BP method, dynamic improvement strategy adopted adjust rotation angle according evolution situation, catastrophe used as an operation criterion during evolution. Then, improved QGA weight threshold from multiple spots. This applied typical process engine....

In this article, an improved particle swarm optimization (IPSO) algorithm based on similarity and random mutation is raised. The diversity of particles in the population decided by size aggregation. When aggregation degree surpass a certain threshold, concept used to measure between global extremum, with higher are discretized strategy. By increasing swarm's diversity, population's local search ability tend balance. weight threshold back propagation (BP) neural networks optimized IPSO...

Planar near-field acoustic holography has been successfully extended to reconstruct the sound field in a moving medium, however, reconstructed still contains convection effect that might lead wrong identification of sources. In order accurately identify sources time-domain equivalent source method is developed. method, real replaced by series whose strengths are solved iteratively utilizing measured pressure and known convective Green's function, time averaging used reduce instability...

A turbulent flow field is created in a vehicle's head during high-speed flight, and this causes the airborne optical system's receiving target images to be displaced, blurred, jittered. In study, we examine impact of 0°-15° angle attack on aero-optical imaging deviation. With use modeling meshing software, model conventional blunt-headed vehicle. Computational fluid dynamics calculations were performed using finite element analysis software; ray equations solved iteratively by Runge-Kutta...

During the process of infrared remote sensing monitoring, obtaining real-time measurements sky background radiation is extremely inconvenient. The current methods incur a certain amount lag. In this study, within existing theoretical framework, fast transmittance calculation method using interpolation was adopted, and simplified transmission model established. This led to development new for rapid temperature humidity retrieval. Compared line-by-line integration method, significantly...

In fields such as manufacturing and aerospace, remaining useful life (RUL) prediction estimates the failure time of high-value assets like industrial equipment aircraft engines by analyzing series data collected from various sensors, enabling more effective predictive maintenance. However, significant temporal diversity operational complexity during operation make it difficult for traditional single-scale, single-dimensional feature extraction methods to effectively capture complex...

Two sound field separation techniques based on equivalent source method are proposed:one is the double-layer pressure measurements and other single-layer pressure-velocity measurements. In this paper, a technique but using velocity proposed. First, theoretical description of given, then numerical simulations experiments conducted to demonstrate validity technique. By comparison with measurements, superiority proposed in separating particle shown. And also, simulations, influences strength...