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The influence of temperature, irradiance and shielding ratio on the output characteristic curve of photovoltaic cells was studied in this paper. In order to improve the photoelectric conversion efficiency of photovoltaic cells, combining three major factors that affect photovoltaic cells, a maximum power point tracking (MPPT) scheme based on large variation genetic algorithm was proposed. In this...
A PD nonlinear dynamic inverse guidance law finite time convergence is proposed for the problem of UAV's collision avoidance in this paper. First, a proportional-derivative nonlinear dynamic inverse guidance law, which can be applied to multiple initial angles and speeds, is designed to ensure the security of UAV's collision avoidance. In addition, the stability of guidance law is proved by the circle...
As a special task beyond general object detection, pedestrian detection has attracted much attention in recent years. Despite the significant improvements, detecting pedestrians is still a challenging task, especially for small-size pedestrians. In this paper, we present a multi-scale feature fusion convolutional neural network (MFF-CNN) for pedestrian detection. The MFF-CNN is benchmarked on three...
This paper proposes a novel method to acquire MEMS resonator's temperature based on the measurement of quality factor via continuous ring-down without additional thermometer. Quality factor, a parameter of resonator is utilized as a virtual thermometer, which attenuates measuring hysteresis and improves the performance of temperature compensation. In addition, to precisely measure the quality factor,...
Safety and efficiency of carrier flight deck are two important factors that have great effects on the comprehensive performance of carrier. This paper studies on path planning algorithms for carrier aircraft on the deck in consideration of safety and efficiency requirements. Firstly, a kinematic model of the carrier aircraft, obstacle avoidance models and boundary constraints are proposed. Subsequently,...
An all-optical multilevel amplitude regenerator is optimized based on the transmission response of a nonlinear optical loop mirror (NOLM). Three regenerative regions defined by the power-transfer-function (PTF) slope of less than 1 are obtained, and noise suppression is shown for a PAM4 signal. Using amplitude dithering we were able to experimentally characterize the transfer function slope and confirm...
By an orchestra of multiple enabling techniques at the transmitter and receiver, we experimentally demonstrate a single-channel 102.4-Gb/s transmission up to 240-km standard single-mode fiber (SSMF) at C-band with direct detection. At the transmitter, we realize Nyquist-pulse shaping PAM-4 (NPAM-4) modulation and single-sideband modulation by using a dual-drive Mach-Zehnder modulator. At the receiver,...
We study the artificial neural network (ANN) and feed forward equalizer jointly to mitigate the inter-symbol interference (ISI) and the nonlinear distortions in the optical single-side band and direct-detection (DD) system. The optical SSB signal is generated by a relatively low-cost dual-drive Mach-Zehnder modulator (DDMZM). The two driving signals are a pair of Hilbert signals with Nyquist pulse-shaped...
A new low-loss quasi-transverse electromagnetic (TEM) microstrip line, called as a self-packaged microstrip line, is proposed for microwave and millimeter-wave applications. It is fully based on the low-cost PCB process, but without the issues of radiation and surface waves by using a top layer perfect magnetic conductor (PMC) substrate. The self-packaged microstrip line consists of three layer substrates:...
In fact, the blackbody furnace running in high temperature is a typical unsteady linear system which is discovered by experiment. Temperature control characteristic is changing with the internal temperature of the furnace. Conventional control methods can not meet the control demand which result in the fluctuation of the internal temperature. Therefore, this paper introduces a control method which...
A miniaturized dual-band Vivaldi antenna based on low frequency resonance is presented. Compared with traditional traveling wave mode Vivaldi antenna, the proposed antenna has a smaller size due to the use of self-resonant mode. The antenna is designed to operate at WLAN 2.4/5.2/5.8 GHz band and has a physical dimension of 25 × 28 mm2. A prototype was fabricated and tested, the results show that the...
This paper presents a variational Bayesian-based adaptive unscented particle filter (VB-AUPF) to improve the positioning accuracy of BDS/INS integrated system under the condition without accurate measurement noise covariance. This method approximates the joint posterior distribution of states and measurement noise by using variational Bayesian approach on each time step. Based on this, the measurement...
This paper presents a novel unsupervised domain adaptation method for cross-domain visual recognition. We propose a unified framework that reduces the shift between domains both statistically and geometrically, referred to as Joint Geometrical and Statistical Alignment (JGSA). Specifically, we learn two coupled projections that project the source domain and target domain data into low-dimensional...
In this paper, aiming to improving robustness of the antenna used both on metallic objects and in air, a novel method including two steps is implemented. The first and the second steps are to ensure a good property of the antenna on metallic objects and in air, respectively. Noticeably, this method is univeral. Using the above method, a compact UHF RFID antenna with meandered dipoles and modified...
In this paper, we address a haze removal problem from a single nighttime image, even in the presence of varicolored and non-uniform illumination. The core idea lies in a novel maximum reflectance prior. We first introduce the nighttime hazy imaging model, which includes a local ambient illumination item in both direct attenuation term and scattering term. Then, we propose a simple but effective image...
A method of fabricating silicon microsphere resonators feathered high quality factor whispering gallery modes of ∼ 0.8 × 106 is demonstrated. We fabricate the silicon microspheres from silica-cladding/silicon-core fiber based on the CO2 laser induced in-fiber capillary instability phenomenon.
By introducing sinusoidal phase-modulated feedback to semiconductor lasers of closed-loop chaos-based communication system, the efficient bandwidth of chaotic carrier can be broadened greatly, the BER performance can be improved, and the communication security is enhanced.
A simulation design was presented to optimise the model of long period grating based fibre devices. The simulation used a modified phase matching condition to better estimate the resonance wavelengths in the transmission profile. Experiments were conducted to verify the results obtained in the simulation. The experimental results matched closely with the simulations.
Opinion target extraction aims to find the object to which an opinion is expressed. It is helpful in getting a comprehensive understanding about public opinions on hot spot social events. In Chinese microblog posts analysis, due to the absence of words with emotional tendency (opinion words), traditional approaches relying on opinion words are not suitable. In this paper, we propose an unsupervised...
We propose and demonstrate a Hilbert Superposition (HS) scheme in an optical single side-band (SSB) modulation and direct-detection system. The optical SSB signal is generated by a relatively low-cost dual-drive Mach-Zehnder modulator (DDMZM) biased at the quadrature point. The two driving signals are a pair of Hilbert signals with Nyquist pulse-shaped four-level pulse amplitude modulation (NPAM-4)...
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