A wavelet-based neural network is described. The structure of this similar to that the radial basis function (RBF) network, except in present paper functions are replaced by orthonormal scaling not necessarily radial-symmetric. efficacy type learning and estimation demonstrated through theoretical analysis experimental results. In particular, it has been shown wavelet universal L/sup 2/ approximation properties a consistent estimator. Convergence rates associated with these obtained for...

Abstract Neurons in ventral pallidum fire to reward and its predictive cues. We tested mesolimbic activation effects on neural coding. Rats learned that a Pavlovian conditioned stimulus (CS+1 tone) predicted second (CS+2 feeder click) followed by an unconditioned (UCS sucrose reward). Some rats were sensitized amphetamine after training. Electrophysiological activity of pallidal neurons stimuli was later recorded under the influence vehicle or acute injection. Both sensitization increased...

Recent experimental results of three kinds long-pulse high-power microwave (HPM) sources operating in S-, C-, and X-bands are reported. The difficulties producing a HPM for the O-type Cerenkov source were analyzed theoretically. In S- C-bands, single-mode relativistic backward-wave oscillators designed to achieve outputs; X-band, because its shorter wavelength, an with overmoded slow-wave systems was increase power capacity. experiments, driven by repetitive accelerator, both C-band...

The deployment of deep convolutional neural networks (CNNs) in synthetic aperture radar (SAR) ship real-time detection is largely hindered by huge computational cost. In this article, we propose a novel learning scheme for training lightweight detector called Tiny YOLO-Lite, which simultaneously 1) reduces the model storage size; 2) decreases floating point operations (FLOPs) calculation; and 3) guarantees high accuracy with faster speed. This achieved self-designed backbone structure...

Even after 50 years of development, narrowband high-power microwave (HPM) source technologies remain the focus much research due to intense interest in innovative applications HPMs fields such as directed energy, space propulsion, and radar. A few decades ago, main aim investigations this field was enhance output power a single HPM tens or hundreds gigawatts, but goal has proven difficult physical limitations. Therefore, recent into sources focused on five targets: phase locking combination,...

The static world assumption is standard in most simultaneous localisation and mapping (SLAM) algorithms. Increased deployment of autonomous systems to unstructured dynamic environments driving a need identify moving objects estimate their velocity real-time. Most existing SLAM based approaches rely on database 3D models or impose significant motion constraints. In this paper, we propose new feature-based, model-free, object-aware algorithm that exploits semantic segmentation allow estimation...

At present, deep learning has been widely used in SAR ship target detection, but the accurate and real-time detection of multi-scale targets still faces tough challenges. CNN-based detectors are challenged to meet requirements because a large number parameters. In this paper, we propose lightweight, single-stage model called YOLO-based lightweight detector (LMSD-YOLO), with better adaptation capabilities. The proposed LMSD-YOLO consists depthwise separable convolution, batch normalization...

Unmanned aerial vehicles (UAVs) have been widely used in post-disaster search and rescue operations, object tracking, other tasks. Therefore, the autonomous perception of UAVs based on computer vision has become a research hotspot recent years. However, UAV images include dense objects, small arbitrary directions, which bring about significant challenges to existing detection methods. To alleviate these issues, we propose global-local feature enhanced network (GLF-Net). Considering...

Research progresses on Cherenkov and transit-time high-power microwave (HPM) sources in National University of Defense Technology (NUDT) China are presented. The research issues focused the following aspects. pulse-shortening phenomenon O-type Cerenkov HPM devices is suppressed. compact coaxial relativistic backward-wave oscillators (RBWOs) at low bands developed. power efficiency M-Type tubes without guiding magnetic field increased. capacities efficiencies triaxial klystron amplifier (TKA)...

The newly raised two-dimensional material MoS2 is regarded as an ideal candidate for saturated absorbers. Here, the open-aperture Z-scan method used to study saturation absorption (SA) response of monolayer and multilayer MoS2, considering laser irradiation with different pulse widths. Specifically, in cases 10 ns ps pulses, accumulative nonlinearity [e.g., free carrier (FCA)] coupled SA found both MoS2. However, under a 65 fs laser, instantaneous two-photon (TPA)] effect turn play...

Abstract The acquisition of near‐infrared (NIR) spectral information is most notably accessed in the scientific analysis and industrial technology. With development artificial intelligence technology, miniature NIR spectrometers are usually required to realize compact equipment. Quantum dot spectrometer demonstrated be a promising reconstructive spectrometer; however, range limited visible due lack high‐resolution detectors quantum filters. In this work, constructed by integrating 195 finely...

In this article, an ultrahigh repetition frequency sub-nanosecond pulse generator based on vanadium-compensated semi-insulating (VCSI) 4H-SiC photoconductive semiconductor switch (PCSS) under high bias electric field is presented. work, the 0.8 mm-thick PCSS was found to work with fields up 200 kV/cm and power capacity of 176 kW. The VCSI response test performed a 1 MHz, 1030 nm laser cluster driver configurable optical pulsewidth current viewing resistor (CVR) circuit. experiment, varied...

With ultrashort laser pulses (25 fs) and low energy (E=15 mJ), we observe plasma channels with a length over 5 m in air. The diameter of the channel is measured to be 120 microm. average electron density inferred about 10(18) W/cm(3) an interferometric method. At same time, temporal evolution investigated. resistivity less than 1 Omega cm. It suggested that lifetime can greatly prolonged by launching another long pulse along channel.

The initial experimental results of an L-band coaxial relativistic backward wave oscillator with mechanical frequency tunability are presented. key effects the inner-conductor contributing to investigated theoretically and experimentally. In experiments, microwave 1.58 GHz is radiated when radius 1.5 cm. Meanwhile, S-band 2.31 generated after removing inner-conductor. addition, tuning within 4% realized by mechanically altering at a half power level.

Digital holographic microscopy allows determination of dynamic changes in the optical thickness profile a transparent object with sub-wavelength accuracy. Here, we report quantitative phase laser microsurgery system for evaluation cellular/ sub-cellular during micro-dissection. The proposed method takes advantage precise manipulation by microbeam and imaging digital high spatial temporal resolution. This will permit damage and/or repair cell or organelles real time.

Current synthetic aperture radar (SAR) ship detectors achieve excellent performance with sufficient samples while encountering degraded results when the sensors and imaging conditions change. The mismatch of view, shape, illumination inevitably result in variations feature distribution between source domain target domain, which will lead to detection degradation. Therefore, devising a detector well transferability new domains remains challenging issue. To this end, letter proposes novel...

The initial experimental results of an L-band relativistic backward wave oscillator with a coaxial slow-wave structure are presented. asymmetric-mode-competition mechanism in the device is investigated theoretically and experimentally. It shown that diode voltage, guiding-magnetic field, concentricity play key role suppression excitation asymmetric-mode (coaxial quasi-TE11 mode). In experiments, frequency 2.05 GHz suppressed excited, which good agreement theoretical results.

Overmoded slow wave structures (SWSs) with large diameter are utilized in O-type Cerenkov high-power microwave (HPM) sources for their high power capacity. However, multi-modes may be output simultaneously the overmoded HPM sources. In order to achieve mode purity, composition of should analyzed quantitatively when structure this type device is being optimized. Two accurate numerical methods making quantitative analysis particle-in-cell model introduced paper. And then, an X-band oscillator...

This paper proposes to integrate two different distances measure the dissimilarity between neighboring pixels in PolSAR images, and introduces entropy rate method into image superpixel segmentation. Since Gaussian model is commonly used for homogeneous scenes less suitable heterogeneous scenes, we adopt spherically invariant random vector (SIRV) describe back-scattering characteristics areas. Moreover, a directional span-driven adaptive (DSDA) region proposed such that it contains...

Continuous action recognition in video is more complicated compared with traditional isolated recognition. Besides the high variability of postures and appearances each action, complex temporal dynamics continuous makes this problem challenging. In study, authors propose a hierarchical framework combining convolutional neural network (CNN) hidden Markov model (HMM), which recognises segments actions simultaneously. The utilise CNN's powerful capacity learning level features directly from raw...

A frequency-agile microwave generating system is examined in this letter. Vanadium-compensated semi-insulation (VCSI) 4H-SiC photoconductive semi- conductor switch (PCSS) has been introduced to achieve wide-range frequency tuning. The output tuned by adjusting the pulse width of laser. Both simulation and experimental results show a tuning range 0.5 GHz 10.0 GHz. maximum operating power at 10 1.13 W, equivalent charging voltage 1.5 kV modulated light wavelength 1064 nm. Further experiment...

In order to increase the power conversion efficiency of a magnetically insulated line oscillator (MILO), an axially extracted virtual cathode (VCO) is introduced utilize load current in MILO, so it called MILO-VCO. this device, MILO and VCO are operated synchronously generate high-power microwaves. The MILO-VCO investigated detail with particle-in-cell (PIC) methods (KARAT code). simulation, diode voltage 640 kV 50 kA. total peak 5.22 GW corresponding 16.3%. MILO-VCO, 3.91 its frequency 1.76...

An X-band magnetically insulated transmission line oscillator has been investigated theoretically and experimentally in our laboratory. However, severe pulse shortening electrode erosion are observed the experiments. The theoretical analyses show that anode plasma formation load region is essential reason for erosion. In order to eliminate or at least minimize region, an improved beam dump presented. can be eliminated minimized dump.