Underwater acoustic localization (UWAL) is a useful technique, and applied in finding the acoustical sources, such as black box. The existing UWAL methods are mainly based on time of arrival (TOA), difference (TDOA), direction (DOA), which need synchronization, knowledge signal period, high precision angular measurement, respectively. However, these conditions difficult to be satisfied scene locating box utilizing single autonomous underwater vehicle. In this article, we propose definition...

Reasoning LLMs such as OpenAI o1, o3 and DeepSeek R1 have made significant progress in mathematics coding, yet find challenging advanced tasks International Mathematical Olympiad (IMO) combinatorics problems, Abstraction Corpus (ARC) puzzles, Humanity's Last Exam (HLE) questions. We use a diverse inference approach that combines multiple models methods at test time. verifying code rejection sampling on other problems is simple effective. automatically verify correctness of solutions to IMO...

To solve the problem of increasing network parameters and fitting fluctuation during training due to improvement or expansion image steganalysis network, a framework for strengthening was considered. The principle searching space optimization by evolutionary algorithm used guide adjustment parameter direction training. Firstly, diversity is initialized based on rules algorithm, coding mapping carried out according structure achieve purpose unifying subsequent objects. Then, state...

Geosynchronous synthetic aperture radar (SAR) (GEO SAR) has the characteristic of long integration time; thus, time-freezing model assumption background ionosphere for traditional low Earth orbit (LEO) SAR no longer holds in GEO SAR. Furthermore, variation within time cannot be omitted either. In this letter, total electron content is analyzed and described detail by using polynomial approximation, a new signal influenced also proposed. view novel model, analytical expression image shift...

Automatic map extraction is of great importance to urban computing and location-based services. Aerial image GPS trajectory data refer two different sources that could be leveraged generate the map, although they carry types information. Most previous works on fusion between aerial images from auxiliary sensors do not fully utilize information both modalities hence suffer issue loss. We propose a deep convolutional neural network called DeepDualMapper which fuses in more seamless manner...

The UAV-borne video SAR (ViSAR) imaging system requires miniaturization, low power consumption, high frame rates, and high-resolution real-time imaging. In order to satisfy the requirements of processing for ViSAR under limited memory parallel computing resources, this paper proposes a method embedded GPU-based ViSAR. Based on programming model compute unified device architecture (CUDA), designed range-Doppler (RD) map drift (MD) algorithms. By utilizing advantages GPU characterized with...

This paper addresses the problem of direction finding for bistatic MIMO radar in presence unknown spatially colored noise. Taking stationary property noise into consideration, a covariance differencing-based method is presented. The proposed has computational complexity very close to that ESPRIT. besides, it can suppress without any virtual aperture loss. Therefore, improves accuracy angle estimation compared with existing de-noising algorithms. Numerical experiments are provided examine...

The unmanned aerial vehicle (UAV)-borne video synthetic aperture radar (SAR) possesses the characteristic of having high-continuous-frame-rate imaging, which is conducive to real-time monitoring ground-moving targets. imaging-processing system for UAV-borne SAR (ViSAR) requires miniaturization, low power consumption, high frame rate, and high-resolution imaging. In order achieve high-frame-rate imaging on limited payload-carrying platforms, this study proposes a miniaturization design...

The state of art Visual SLAM is going from sparse feature to semi-dense provide more information for environment perception, whereas the methods often suffer inaccurate depth map estimation and are easy become instable some real-world scenarios. paper proposes extend ORB-SLAM2 framework, which a robust system tracking camera motion with maintenance loop closure, by introducing unified spherical model map. fits omnidirectional well, therefore proposed could handle fisheye cameras commonly...

Security risks and economic losses of civil aviation caused by Foreign Object Debris (FOD) have increased rapidly. Synthetic Aperture Radars (SARs) with high resolutions potentially the capability to detect FODs on runways, but target echo is hard be distinguished from strong clutter. This paper proposes a clutter-analysis-based Space-time Adaptive Processing (STAP) method in order obtain effective clutter suppression moving FOD indication, under inhomogeneous background. Specifically, we...

An optimization algorithm combining particle swarm (PSO) with convolutional neural network (CNN) is proposed for the design of high-dimensional, and compact segment antennas. Firstly, PSO used to optimize weight CNN, which called PSO-CNN. It can solve local optimal problem backpropagation algorithm. After that, PSO-CNN applied optimized Fragment-type antenna. Compared results traditional simulation software, rapid are obtained.

Traditional constant false alarm rate (CFAR) methods have shown their potential for foreign object debris (FOD) indication. However, the performance of these would deteriorate under complex clutter background in airport scenes. This paper presents a threshold-improved approach based on cell-averaging clutter-map (CA-CM-) CFAR and tests it millimeter-wave (MMW) radar system. Clutter cases are first classified with variability indexes (VIs). In homogeneous background, threshold is calculated...

The dynamics and vibrations of camshaft excited by multi-follower elements are modeled analyzed. A pushrod valve train system from a four-cylinder diesel engine is selected as the case study. to analyze interactions elements. Both angular vibration bending taken into consideration. Each follower element simplified multi-mass system. lumped masses connected spring damping contact force model at cam–tappet interfaces was developed based on elasto-hydrodynamic lubrication theory finite line...

The analysis of intake silencer insertion loss (IL) was conducted using a hybrid numerical method, which combined computational fluid dynamics (CFD) and acoustic finite element method (FEM). First, an experimental test to obtain the compressor noise spectrum under two different conditions: turbocharger directly connected substitution duct silencer, respectively. Then, introduced predict propagation. unsteady flow calculated conditions, pressure fluctuation on impeller inlet plane then...

This paper focuses on the development of absorbing boundary conditions and their implementation in smoothed particle hydrodynamics (SPH) method for wave propagation problems. A compact perfectly matched layer (C-PML) approach is formulated transient acoustic problems an infinite space using SPH models with a computational domain finite dimensions. The proposed based concept fictitious physical damping acting within additional layers (PMLs) to absorb outgoing waves practically eliminate...

The most common type of mixed jamming is composed blanket and deception jamming. In order to effectively detect the target signal in this kind jamming, study presents an algorithm based on side-lobe cancellation (SLC) slope-varying linear frequency modulation signal. entire anti-jamming process divided into two steps. SLC used suppress first, then matched filtering combination these algorithms can accurately target. simulation analysis shows that method

Trains are an important means of transportation for people to travel. The train's soft sleeper compartment space is relatively small, and the density large. Therefore, improving thermal comfort air quality great significance ensuring a healthy travel environment. To analyze appropriate mode conditioned supply in train compartments, airflow distribution inside compartments simulated numerically at four different modes, namely, sidewall with slot diffusers, perforated ceiling supply, bedside...

Radio-frequency (RF) Radiance Field reconstruction is a challenging problem. The difficulty lies in the interactions between propagating signal and objects, such as reflections diffraction, which are hard to model precisely, especially when shapes materials of objects unknown. Previously, neural network-based method was proposed reconstruct RF Field, showing promising results. However, this has some limitations: it requires large number samples for training computationally expensive....

Mainstream DNN-based SAR-ATR methods still face issues such as easy overfitting of a few training data, high computational overhead, and poor interpretability the black-box model. Integrating physical knowledge into DNNs to improve performance achieve higher level becomes key solving above problems. This paper begins by focusing on electromagnetic (EM) backscattering mechanism. We extract EM scattering (EMS) information from complex SAR data integrate properties target network through...

Synthetic Aperture Radar (SAR) is a remote sensing technology capable of high-resolution imaging the ground surface under any weather and light conditions. SAR image ship detection technique that uses target features in images to identify locate ships, which great value for applications fields maritime traffic management, marine environment monitoring, security defence. However, also faces some challenges, such as complex sea background, low signal-to-noise ratio, diversity density targets,...