2019
2019
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Record 37 of
Title:Microcomb-based RF transversal filters
Author(s):Xu, Xingyuan(1); Tan, Mengxi(1); Wu, Jiayang(1); Nguyen, Thach G.(2); Chu, Sai T.(3); Little, Brent E.(4); Morandotti, Roberto(5,6,7); Mitchell, Arnan(2); Moss, David J.(1)Source: Optics InfoBase Conference Papers Volume: Part F144-FiO 2019 Issue: DOI: 10.1364/FIO.2019.FW6C.4.pdf Published: 2019Abstract:We demonstrate high-Q RF filters based on a 49GHz-FSR integrated microcomb source that provides 80 wavelengths across the C-band. A Q factor of 73.7 and an out-of-band rejection of 48.9 dB are demonstrated. ? 2019 The Author(s)Accession Number: 20202008652569 -
Record 38 of
Title:A Novel Double-Index-Constrained, Multi-View, Fuzzy-Clustering Algorithm and its Application for Detecting Epilepsy Electroencephalogram Signals
Author(s):Zhu, Jiaqi(1,2,3); Li, Kang(1,2,3); Xia, Kaijian(4); Gu, Xiaoqing(5); Xue, Jing(6); Qiu, Shi(7); Jiang, Yizhang(1,2,3); Qian, Pengjiang(1,2,3)Source: IEEE Access Volume: 7 Issue: DOI: 10.1109/ACCESS.2019.2931695 Published: 2019Abstract:When processing a multi-view, epilepsy electroencephalogram (EEG) dataset, the traditional single-view clustering algorithms cannot fully mine the correlation information between each view and identify the importance of each view because of the limitations of its own methods. This limitation causes poor clustering performance when using these classic, single-view clustering algorithms. To solve this problem, a novel double-index-constrained, multi-view, fuzzy clustering algorithm (DIC-MV-FCM) is proposed for the automatic detection of epilepsy EEG data. The DIC-MV-FCM algorithm is integrated into the multi-view clustering technology and the view-weighted adaptive learning strategy, which can effectively use the correlation information between each view and control the importance of each view to improve the final clustering performance. The experimental results using several epilepsy EEG datasets show that the proposed DIC-MV-FCM algorithm has better clustering performance than the traditional clustering algorithms for processing multi-view EEG data. ? 2013 IEEE.Accession Number: 20205009608371 -
Record 39 of
Title:Optimal Gimbal System Control Strategy for Error Prediction Compensation
Author(s):Yang, Yongqing(1); Hao, Wei(1); Yu, Tianye(2); Xie, Meilin(2); Liang, Yanbing(1); Liu, Peng(1)Source: Proceedings - 5th International Conference on Control Science and Systems Engineering, ICCSSE 2019 Volume: Issue: DOI: 10.1109/ICCSSE.2019.00022 Published: August 2019Abstract:In order to suppress the periodic error in the control of the gimbal, an error prediction compensation model is established based on the error compensation theory in predictive control. The error feature extraction and matching of the servo gimbal system is completed based on the error time domain and frequency domain analysis results. Based on the analysis of the error energy spectral density characteristics, according to the energy distribution of different frequency bands, combined with the design of the gimbal control system, the influencing factors such as position sensor error, motor drive error and system structure error are obtained. At the same time, determine the impact domain of each factor. Based on this, through the optimal parameter estimation, the design of the error prediction compensation controller is completed, and finally a new optimal control strategy for error prediction compensation gimbal is obtained. Test verification in a high-precision gimbal shows that the control strategy can significantly improve the speed stability of the gimbal system by about 78%. ? 2019 IEEE.Accession Number: 20201708554036 -
Record 40 of
Title:Study on the technology of high-dynamic-range low-light-level remote-sensing camera
Author(s):Bai, Zhe(1); Ma, Yilong(1); Huang, Chao(1); Fan, Xuewu(1)Source: 2019 IEEE 3rd International Conference on Electronic Information Technology and Computer Engineering, EITCE 2019 Volume: Issue: DOI: 10.1109/EITCE47263.2019.9094905 Published: October 2019Abstract:In recent years, Low-Light-Level (LLL) remote-sensing camera has become a novel subject for the development of aerospace optical remote-sensing payloads. In this article, the status quo and trend of LLL remote-sensing imaging technology is introduced. The technical method for LLL remote-sensing imaging is studied. In view of the requirement of high-dynamic-range (HDR) LLL imaging in space remote sensing, a camera based on an Intensified Charge-Coupled Device (ICCD) is designed. A method to measure the signal-to-noise ratio (SNR) of the LLL camera is proposed and tested. A field experiment for the LLL camera is also carried out. The results of testing and experiment indicate that the designed camera is capable of HDR LLL imaging. ? 2019 IEEE.Accession Number: 20202308784554 -
Record 41 of
Title:High-Sensitivity and Long-Life Microchannel Plate Processed by Atomic Layer Deposition
Author(s):Cao, Weiwei(1,2,3); Zhu, Bingli(3); Bai, Xiaohong(3); Xu, Peng(3); Wang, Bo(4); Qin, Junjun(4,5); Gou, Yongsheng(4); Lei, Fanpu(4); Liu, Baiyu(1); Guo, Junjiang(1,2,3); Zhu, Jingping(2); Bai, Yonglin(1)Source: Nanoscale Research Letters Volume: 14 Issue: DOI: 10.1186/s11671-019-2983-1 Published: 2019Abstract:As a key component of electron multiplier device, a microchannel plate (MCP) can be applied in many scientific fields. Pure aluminum oxide (Al2O3) as secondary electron emission (SEE) layer were deposited in the pores of MCP via atomic layer deposition (ALD) to overcome problems such as high dark current and low lifetime which often occur on traditional MCP. In this paper, we systematically investigate the morphology, element distribution, and structure of samples by scanning electron microscopy (SEM) and energy disperse spectroscopy (EDS), respectively. Output current of different thickness of Al2O3 was studied and an optimal thickness was found. Experimental tests show that the average gain of ALD-MCP was nearly five times better than that of traditional MCP, and the ALD-MCP showed better sensitivity and longer lifetime. ? 2019, The Author(s).Accession Number: 20192006915284 -
Record 42 of
Title:Compact optical phased array using a serial grating antenna design
Author(s):Zhang, Lingxuan(1,2); Sun, Xiaochen(1,2); Zhang, Wenfu(1,2); Wang, Guoxi(1,2); Feng, Ningning(1,2); Zhao, Wei(1,2)Source: arXiv Volume: Issue: DOI: null Published: February 16, 2019Abstract:We propose an on-chip Si photonics optical phased array based on a serial grating design which eliminates the use of directional couplers in previous designs. It significantly reduces overall phased array size especially when the number of the antenna is small which is often demanded in practice. The simulation results show our design reduces overall phased array size, increases optical power utilization while maintains comparable far field performance. Copyright ? 2019, The Authors. All rights reserved.Accession Number: 20200232219 -
Record 43 of
Title:MF2.1-On-chip generation, coherent control and processing of complex entangled photon states (invited)
Author(s):Sciara, Stefania(1,2); Reimer, Christian(1,3); Kues, Michael(1,4); Roztocki, Piotr(1); Islam, Mehedi(1); Romero Cortes, Luis(1); Zhang, Yanbing(1); Fisher, Bennet(1); Loranger, Sebastien(5); Kashyap, Raman(5,6); Cino, Alfonso Carmelo(2); Chu, Sai T.(7); Little, Brent E.(8); Moss, David J.(9); Caspani, Lucia(10); Munro, William J.(11,12); Azana, Jose(1); Morandotti, Roberto(1,13,14)Source: IEEE Photonics Society Summer Topical Meeting Series 2019, SUM 2019 Volume: Issue: DOI: 10.1109/PHOSST.2019.8795038 Published: July 2019Abstract:We demonstrate the on-chip generation of time-bin entangled two- and multi-photon qubit states, as well as high-dimensional frequency-entangled photon pairs. Combining time and frequency entanglement, we generate high-dimensional optical cluster states and implement proof-of-concept high-dimensional one-way quantum computing. This, by using standard, fiber-based telecommunication components. ? 2019 IEEE.Accession Number: 20193607403223 -
Record 44 of
Title:Determination of noise index of piezoelectric ceramic drive system based on coupled electro-mechanical model
Author(s):Wang, Xuan(1); Su, Xiuqin(1); Liu, Guizhong(2); Han, Junfeng(1); Yu, Tingting(1)Source: IEEE/ASME International Conference on Advanced Intelligent Mechatronics, AIM Volume: 2019-July Issue: DOI: 10.1109/AIM.2019.8868902 Published: July 2019Abstract:Piezoelectric ceramic ( PZT ) driver is a key component in PZT micro-displacement systems, and the noise index determines the accuracy of the output displacement of the PTZ actuator. In fast steering mirror (FSM) systems, the response of noise in a mechanical system is bound to affect resolution of the system. This paper analyzes the PZT driver system from the perspective of coupled electro-mechanical. By establishing a mathematical model of the coupled electro-mechanical system, we determine the energy of the output noise of the drive system in the mechanical system and the transfer of the electrical noise energy on the electromechanical system actuator. It is then determined that the power consumption of the PTZ actuator is mainly composed of two parts: the energy used to drive the deformation of the system and the dissipation of heat due to structural damping. The noise index of the PTZ driver system is 192.3dB when the accuracy of the output displacement is 1 nm through the energy conversion. The method is universal to be applied to determine the system noise index in various mechatronic systems, as well as to more complex mechanical systems. ? 2019 IEEE.Accession Number: 20194507619909 -
Record 45 of
Title:Open-category classification of hyperspectral images based on convolutional neural networks
Author(s):Huang, Tingting(1,2); Wang, Shuang(3); Zhang, Geng(3); Wang, Xueji(3); Liu, Song(1,2)Source: ACM International Conference Proceeding Series Volume: Issue: DOI: 10.1145/3331453.3362049 Published: October 22, 2019Abstract:The application of the hyperspectral image (HSI) classification has become increasingly important in industry, agriculture and military. In recent years, the accuracy of HIS classification has been greatly improved through deep learning based methods. However, most of the deep learning models tend to classify all the samples into categories that exist in the training data. In real-world classification tasks, it is difficult to obtain samples from all categories that exist in the whole hyperspectral image. In this paper, we design a framework based on convolutional neural networks and probability thresholds(CNPT) in order to deal with the open-category classification(OCC) problem. Instead of classifying samples of categories that do not exist in the training process to be any known class, the proposed method mark them as unseen category. We first get samples of unseen class from labeled data. With a lightweight convolutional network that fully uses the spectral-spatial information of HSI, we obtain the probabilities for each seen class for every sample. By adding a threshold to the maximum probabilities, we classify some samples to unseen category. A balanced score called Fue which considers both the recall rate of unseen class and the overall accuracy of seen classes is proposed in this paper, and we use it to select the threshold and evaluate the performance of CNPT. The experimental results show that our proposed algorithm performs well on hyperspectral data, and has generalizability on different datasets. ? 2019 Association for Computing Machinery.Accession Number: 20194607684207 -
Record 46 of
Title:Structural parameters optimization of lens hood based on a kind of surrogate model
Author(s):Song, Yang(1); Chai, Wenyi(1); Xin, Wei(1); Xu, Yang(1); Hu, Yongming(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11170 Issue: DOI: 10.1117/12.2531069 Published: 2019Abstract:With the wide use of earth-based laser communication system, more and more engineers like to pursue the design of lightweight structure. Nowadays, engineers often firstly depend on the project experience to design the lens hood, then make analysis based on finite element method to verify its feasibility, but it costs too much time. The paper attempts to give a new optimization design method. Surrogate model are widely used in the fields of aerodynamics parameters optimization, but barely used in design of optical structure. The paper makes an optimal design about lens hood with wide aperture based on surrogate model. First of all, the paper generates some samples by finite element method; secondly, uses the samples to get the surrogate model by surface interpolation; then finds the optimal solution by surrogate model and constraint conditions. The aperture of the lens hood in this paper is 450 mm. One end of the lens hood is attached to main structure, and the other end is free. Middle part of the lens hood is supported by rods which are made of carbon fiber. The optimization variables in this paper is the thickness of the lens hood and the location of the supports robs. The purpose of the optimization is to find the case that the weight is light and displacement of the free end is small. It will not let the miscellaneous light make a negative effect on incident or outgoing path of light. In other words, it will ensure the quality of imagining or effect of detection. The appropriate solution is found by the method proposed in this paper. ? 2019 SPIE.Accession Number: 20193107262576 -
Record 47 of
Title:Micro-vibration test and imaging analysis during space camera thermal-optical test
Author(s):She, Wenji(1); Cui, Kai(1); Gao, Xiong(1); Li, Shuxiu(1); Wang, Huan(1); Yang, Wei(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11341 Issue: DOI: 10.1117/12.2543762 Published: 2019Abstract:The high resolution space optical camera imaging quality was sensitive to micro-vibration both in space and on the ground test. When performing the thermal-optical test within a vacuum tank, the affiliated air compressor pump, the turbo molecular pump and other pump assembles may cause micro-vibration transmitting to the payload. Firstly, the threshold and frequency bandwidth of the camera mounting flange micro-vibration were calculated based on the cameral optics and structure rigid-body theory. Secondly, three linear accelerometers were used for micro-vibration signals acquiring, and the identification plate was used for imaging. The signals and photos were acquired at the same time during the pumps turned on and turned off separately. Finally, the vibration caused by the pump assembles were analyzed after the thermal-optical experiment process, together with the images' MTF. It's shown that even the vacuum tank was isolated on the ground, the affiliated s' micro-vibration ed to the inside payload, causing a previous vibration The STD of Z axis micro-vibration signal more than 3 times from 2.1mg to 9.5mg, Exceeding the analysised threshold from 9Hz to 16Hz and near the 146Hz, the peak vealue was about 3 times of the threshold at 13 Hz, while the MTF declined little, just about 2.5%. ? 2019 SPIE.Accession Number: 20200408063354 -
Record 48 of
Title:Multi-Modal Gated Recurrent Units for Image Description
Author(s):Li, Xuelong(2); Li, Xuelong(1,2); Yuan, Aihong(2); Lu, Xiaoqiang(2)Source: arXiv Volume: Issue: DOI: null Published: April 20, 2019Abstract:Using a natural language sentence to describe the content of an image is a challenging but very important task. It is challenging because a description must not only capture objects contained in the image and the relationships among them, but also be relevant and grammatically correct. In this paper a multi-modal embedding model based on gated recurrent units (GRU) which can generate variable-length description for a given image. In the training step, we apply the convolutional neural network (CNN) to extract the image feature. Then the feature is imported into the multi-modal GRU as well as the corresponding sentence representations. The multi-modal GRU learns the inter-modal relations between image and sentence. And in the testing step, when an image is imported to our multi-modal GRU model, a sentence which describes the image content is generated. The experimental results demonstrate that our multi-modal GRU model obtains the state-of-the-art performance on Flickr8K, Flickr30K and MS COCO datasets. Copyright ? 2019, The Authors. All rights reserved.Accession Number: 20200266505