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A robust photonic DIFF exploiting the slow light effect in a photonic crystal waveguide is proposed and experimentally demonstrated. Input Gaussian pulses with full-width half-maximums ranging from 2.7 ps to 81.4 ps can be accurately differentiated.
A novel concept to generate linear chirped microwave signal is proposed and experimentally verified. The frequency to time mapping method is used while the Mach-Zehnder interferometer based on the photonic crystal waveguide is employed as the key device with its significant advantages of the ultra-compact footprint and simple design.
Wireless Software Defined Network (W-SDN) is the application of SDN technology in wireless network and has been widely used in sensor network, 5G communication network, et al. Since SDN needs to install flow entries at every hop to match each data packet, then it may bring heavy burden to the wireless nodes as the wireless node usually has much smaller memory space comparing with network devices in...
In view of the emotional polarity classification problem, the deep learning has the disadvantages of incomplete information extraction and low precision, a model combining bi-directional gated recurrent unit with multiple convolution neural network is proposed. The unit is used to extract the history and future information of the sentence, then use the multi-convolution neural network for system training,...
This article presents a developmental method to identify the maximum pose error for Stewart platform. The pose error is mainly caused by installation errors, joint clearance errors and the actuation errors. The relationship between pose error and installation errors, as well as branch length errors, are derived from inverse kinematic equations. Utilizing D-H (Denavit-Hartenberg) matrix differential...
The modern image search system requires semantic understanding of image, and a key yet under-addressed problem is to learn a good metric for measuring the similarity between images. While deep metric learning has yielded impressive performance gains by extracting high level abstractions from image data, a proper objective loss function becomes the central issue to boost the performance. In this paper,...
This paper describes the design, fabrication, and testing of a photonic MEMS accelerometer that uses a hemispherical microcavity to transduce the motion of the proof mass. The cavity design provides stable operation that is relatively tolerant of misalignment errors. The prototype sensor is shown to have optical resonances that closely match the expected Airy function model.
A new plastic-rubber water lubricated bearing material SPB-N has been developed by blending the mixture of Ultra-high molecular weight polyethylene(UHMWPE) and graphite into nitrile rubber(NBR). It has good wear resistance and low friction. The friction coefficient was measured on the test rig SSB-100 to evaluate the friction characteristics under different velocities and specific pressures. Furthermore,...
Traditional shipping industry has been artificially divided into two relatively independent closed circulatory systems of river and sea for a long time. However, it has been unable to meet the service requirements of the shipping industry in rapidity and logistics at present. Therefore the original systems should be upgraded. The 45000 DWT Sea-River Bulk Carrier model is proposed in this paper. The...
Hazardous to synthetic aperture radar (SAR), the radio frequency interference (RFI) significantly degrades the SAR imaging quality and prevents accurate image interpretation. In recent years, RFI mitigation has received intensive attention in the active microwave remote sensing community. Making use of the statistical distribution of RFI and SAR echoes, this paper proposes a new method for RFI suppression...
Radio frequency interference (RFI) is a major issue for synthetic aperture radar (SAR), and would affect the image quality and image interpretation. The majority of existing methods are applied on each azimuth echoes along range direction with the assumption that bandwidth of RFI is less than that of SAR. However, if SAR echoes are contaminated by ultra wide-band RFI, i.e., the bandwidth of RFI is...
Radio frequency interference (RFI) is a critical issue for Polarimetric synthetic aperture radar (PolSAR). The analysis of RFI signatures and its influence on PolSAR data seems to be lacking in existing literatures, especially for PolSAR post products, such as the polarimetric decomposition parameters and clustering result. The goal of this paper is trying to reveal the link between RFI and polarization,...
We demonstrate that by inserting bi-layer graphene inside silicon waveguide, the modulation ability of the overall waveguide can be greatly enhanced. A Mach-Zehnder modulator based on this structure is proposed and the calculated results show the modulator exhibits an excellent performance in terms of small footprint (35 μm2) and high extinction ration (31 dB). Besides, it requires low applied voltage...
Convolutional Neural Networks (CNNs) with Bilinear Pooling, initially in their full form and later using compact representations, have yielded impressive performance gains on a wide range of visual tasks, including fine-grained visual categorization, visual question answering, face recognition, and description of texture and style. The key to their success lies in the spatially invariant modeling...
Multiple informative polarimetric descriptors can be computed from direct measurements of polarimetric covariance matrix and target decomposition theorems. Under the tensor algebra framework, each pixel is modeled as a third-order tensor object by combining multi-features and incorporating neighborhood spatial information together. Typically, the tensor object is of high correlation and redundancy...
Digital metering devices is taking important place in new generation of intelligent substation, but the method to analysis their error is not fit to its new characteristics. Aiming to improve the accuracy of error analysis result, this paper analyzed the error source of digital metering devices, and attempted to acquire how much do these influences affects the metering accuracy of digital metering...
We propose and experimentally demonstrate an on-chip low power consumption optical diode based on the optomechanical effect. The forward-backward nonreciprocal transmission ratio (NTR) is 10.9 dB under 3.5 mW input power, the resonance red-shift is up to 0.70 nm.
We propose and experimentally demonstrate a temporal cloak with the new capability not only to conceal pseudorandom inverted return-to-zero optical data (cloaking mode), but also to create “illusion” optical data for observer at telecommunication data rate (romanticizing mode).
In this paper, the problem of robust minimax testing of binary composite hypothesis is considered, while the actual probability densities are located in neighborhoods characterized by the Itakura-Saito divergence. And then the existence of a saddle value condition is proved under Sion's minimax theorem. Moreover, we derive the least favorable distributions and the robust decision rule involved four...
More and more on-line experiments have been done in E-Commerce in order to understand the behavior of users or customers and then apply the data analysis technique to provide business guidance. One of the techniques is A/B testing. However, there is not clear guidance on the sample size in order for us to have valuable, trustable discovery. The purpose of this work is to find out a way to group customers...
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