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Using Reduced Graphene Oxide to Generate Q-Switched Pulses in Er-Doped Fiber Laser

Chinese Physics Letters 2018年第11期35卷 32-34页

作者： Lu Li Rui-Dong Lv Si-Cong Liu Zhen-Dong Chen Jiang Wang Yong-Gang Wang Wei Ren School of Science Xi＇an University of Posts and TelecommunicationsXi＇an 710121 School of Physics and information Technology Shaanxi Normal UniversityXi＇an 710119 Shaanxi Key Laboratory of Information Communication Network and Security Xi＇an University of Posts and TelecommunicationsXi＇an 710121

Using the reduced graphene oxide（rGO） as a saturable absorber（SA） in an Er-doped fiber（EDF） laser cavity,we obtain the Q-switching operation. The rGO SA is prepared by depositing the GO on fluorine mica（FM） using the thermal reduction method. The modulation depth of rGO/FM is measured to be 3.2%. By incorporating the rGO/FM film into the EDF laser cavity, we obtain stable Q-switched pulses. The shortest pulse duration is3.53 μs, and the maximum single pulse energy is 48.19 nJ. The long-term stability of working is well *** experimental results show that the rGO possesses potential photonics applications.

关键词： EDF GO Using Reduced Graphene Oxide to Generate Q-Switched Pulses in Er-Doped Fiber Laser SA

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A Dynamic Time Warping Based Wake-Up Signal Detection Method for Underwater Acoustic communication Networks 2

A Dynamic Time Warping Based Wake-Up Signal Detection Method...

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2nd IEEE Advanced information Management, Communicates, Electronic and Automation control Conference, IMCEC 2018

作者： Ma, Lu Fan, Cheng Sun, Wei Qiao, Gang Science and Technology on Communication Information Security Control Laboratory Jiaxing Zhejiang China College of Underwater Acoustic Engineering Harbin Engineering University Harbin China

ISBN: (纸本)9781538618035

T400 conventional underwater acoustic (UWA) wakeup signals detection methods for both underwater cooperative nodes and non-cooperative nodes are FFT based signal detection and matched-filtered based signal detection. While there is a big performance degradation of these conventional frequency-offset sensitive methods due to the relative motion between nodes, complex underwater noise environment, channel time-varying and other interference sources. This paper proposes a dynamic time warping (DTW) algorithm to detect the wake-up signal in UWA communication networks, which is frequency-offset insensitive and performs better than the conventional methods in severe frequency-offset environment by simulations based on the true UWA channel measured from sea trial. © 2018 IEEE.

关键词： Signal detection

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A Real-Time Detection System for Non-Cooperative Underwater Acoustic DSSS Signals Based on LabVIEW 2

A Real-Time Detection System for Non-Cooperative Underwater ...

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2nd IEEE Advanced information Management, Communicates, Electronic and Automation control Conference, IMCEC 2018

ISBN: (纸本)9781538618035

B397 of the good concealment, the application of DSSS signals are more and more attractive in underwater acoustic (UWA) communication. While for UWA communication countermeasure system, blind detection of non-cooperative UWA DSSS signals is the first and essential step. A software for non-cooperative UWA DSSS signals detection is developed based on LabVIEW, which integrates power spectrum method, cepstrum method, autocorrelation method and corresponding improved methods. With the help of acquisition card and acoustic transducer, many functions can be implemented such as real-time acquisition and storage, detection processing and the results display for the received signals. What's more, different detection methods can be independently or jointly used by arbitrarily adjusting the display and control interface in real time. © 2018 IEEE.

关键词： Underwater acoustics

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Comparison of Jamming Methods for Underwater Acoustic DSSS communication Systems 2

Comparison of Jamming Methods for Underwater Acoustic DSSS C...

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2nd IEEE Advanced information Management, Communicates, Electronic and Automation control Conference, IMCEC 2018

ISBN: (纸本)9781538618035

W399 the development of underwater acoustic communications (UWAC), jamming methods for UWAC becomes much more attentive in communication countermeasure system. Direct sequence spread spectrum (DSSS) signal as a way of reliable covert communications is widely used for UWA channels. In this paper, single-tone jamming, narrowband jamming and correlated jamming based on PN code PSK modulation for UWA DSSS communication system are compared under different signal-to-noise ratio first, which assumes that the jammer knows perfect parameters in DSSS signal. Besides, performance of the above three jamming methods are compared by simulations under the blind estimates of carrier frequency, chip length, period of PN code and PN code itself, which demonstrates the influence of the estimation error on these jamming methods. © 2018 IEEE.

关键词： Underwater acoustic communication

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LOS/NLOS Channel Identification technology Based on CNN

LOS/NLOS Channel Identification Technology Based on CNN

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National Foundation for science and technology Development Conference on information and Computer science (NICS)

作者： Fei Wang Zhan Xu Ruxin Zhi Jinhui Chen Peiyue Zhang School of Information and Communication Engineering Beijing Information Science and Technology University Beijing China Key Laboratory of Modern Measurement & Control Technology Beijing Information Science & Technology University Beijing China

ISBN: (数字)9781728151632

ISBN: (纸本)9781728151649

In the field of indoor positioning, ultra-wideband (UWB) communication technology is the key technology. But the errors caused by non-line of sight (NLOS) communication channels could greatly affect the positioning accuracy. Therefore, identifying the channel type can effectively avoid the above-mentioned errors, thereby helping to reduce the loss of positioning accuracy. This paper proposes a LOS/NLOS channel identification method by using a convolutional neural network (CNN) to identifying the impulse response figures of the channels. This method is capable of identifying four different types of channel impulse response figures and providing excellent identification accuracy. The results show that the accuracy of identifying LOS (0-4m), NLOS (0-4m), NLOS (4-10m) and extreme NLOS channel impulse response figures can reach 98.24%.

关键词： Delays Training Support vector machines IEEE 802.15 Standard Computer science Channel models

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Fixed-state Log-MAP detection for intensity-modulation and direct-detection optical systems over dispersion-uncompensated links

arXiv

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arXiv 2020年

作者： Shuangyue, L.I.U. Zhou, Ji Wang, Haide Mengqi, G.U.O. Xuekai, X.U. Yueming, L.U. Qiao, Yaojun State Key Laboratory of Information Photonics and Optical Communications School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing100876 China Department of Electronic Engineering College of Information Science and Technology Jinan University Guangzhou510632 China Key Laboratory of Trustworthy Distributed Computing and Service Ministry of Education School ofCyberspace Security Beijing University of Posts and Telecommunications Beijing100876 China

In this paper, an optimized detection using log-maximum a posteriori estimation with a fixed number of surviving states (fixed-state Log-MAP) is proposed for a C-band 64-Gbit/s intensity-modulation and direct-detection (IM/DD) on-off keying (OOK) system over a 100-km dispersion-uncompensated link. For dispersion-uncompensated links, maximum likelihood sequence estimation (MLSE) is usually employed to deal with the severe inter-symbol interference (ISI) caused by chromatic dispersion. However, MLSE has an exponential increase in computational complexity and state storage with an increase in memory length, which overloads the computing resources and internal storage space of the hardware. Compared to MLSE, the fixed-state Log-MAP decreases the computational complexity and state storage from an exponential order of memory length to a linear order of surviving states. The memory length of fixed-state Log-MAP is no longer limited by computing resources and storage resources of the hardware, which has the potential to compensate larger ISI. The experimental results show that the optimal receiver sensitivity using fixed-state Log-MAP detection has a 2-dB improvement compared to that using MLSE. In conclusion, the fixed-state Log-MAP detection shows potential for practical IM/DD optical systems over dispersion-uncompensated links. Copyright © 2020, The Authors. All rights reserved.

关键词： Computational complexity

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Research on Evaluation Index System for Software Vulnerability Analysis Methods

Research on Evaluation Index System for Software Vulnerabili...

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IEEE International Conference on Data science in Cyberspace (DSC)

作者： Jin Li Min-Huan Huang Shuai-Bing Lu Hu Li Jin-Fu Chen National Key Laboratory of Science and Technology on Information System Security Beijing China School of Computer Science and Communication Engineering Jiangsu University China

Due to the diversity of existing software vulnerability analysis methods, a unified index system is required if we are to accurately and comprehensively evaluate the analytic effects in order to further improve the level of analysis. Accordingly, this paper first proposes the principles and process necessary to construct an evaluation index system for software vulnerability analysis. Moreover, by focusing on the problems identified in previous relevant research, an evaluation index system for software vulnerability analysis methods that contains four aspects-accuracy, coverage, value and performance-is proposed; this system is more comprehensive and complete than existing achievements. Finally, using the vulnerability analysis testing framework, the indexes of the three different versions of cppcheck are measured. The results show that the proposed evaluation index system can be used for the comparative evaluation of different vulnerability analysis methods.

关键词： Indexes Software Tools Testing Penetration testing

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SAR Ship Target Detection Based on 2D Singularity Power Spectrum

SAR Ship Target Detection Based on 2D Singularity Power Spec...

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IEEE International Conference on Radar

作者： Gang Xiong Fang Wang Lijun Wang Jin He School of Electronic Information and Electrical Engineering Shanghai Jiao Tong University Dept. of Statistical Information Shanghai Jiao Tong University Shanghai China Science and Technology on Communication Information Security Control Laboratory Jiaxing China

ISBN: (数字)9781728126609

ISBN: (纸本)9781728137858

A novel SAR ship target detection method based on two-dimensional singularity power spectrum (2DSPS) analysis is proposed. The 2D-SPS of SAR images explores a variety of coupling features, including the dispersion of singularity exponent and the power distribution in the singularity domain, and has strong ability in feature extraction for SAR images of pure sea surface, false alarm at sea, small targets and multiple targets under the conditions of complex sea surface. The method of SAR target detection based on 2D-SPS are designed. Using the OpenSAR Dataset, in the background of sea clutter, the simulation results show that the proposed method performs better than the traditional method under the condition of extremely low SNR and strong false alarm, especially for small SAR targets and multiple SAR targets.

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Heavy metals prediction in coastal marine sediments using hybridized machine learning models with metaheuristic optimization algorithm

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Chemosphere 2024年 352卷 141329页

作者： Yaseen, Zaher Mundher Melini Wan Mohtar, Wan Hanna Homod, Raad Z. Alawi, Omer A. Abba, Sani I. Oudah, Atheer Y. Togun, Hussein Goliatt, Leonardo Ul Hassan Kazmi, Syed Shabi Tao, Hai Civil and Environmental Engineering Department King Fahd University of Petroleum and Minerals Dhahran 31261 Saudi Arabia Interdisciplinary Research Center for Membranes and Water Security King Fahd University of Petroleum & Minerals (KFUPM) Dhahran Saudi Arabia Department of Civil Engineering Faculty of Engineering and Built Environment Universiti Kebangsaan Malaysia UKM Selangor Bangi 43600 Malaysia Environmental Management Centre Institute of Climate Change Universiti Kebangsaan Malaysia Selangor UKM Bangi 43600 Malaysia Department of Oil and Gas Engineering Basrah University for Oil and Gas Basra Iraq Department of Thermofluids School of Mechanical Engineering Universiti Teknologi Malaysia UTM Skudai Johor Bahru 81310 Malaysia Department of Computer Sciences College of Education for Pure Science University of Thi-Qar Nasiriyah 64001 Iraq Information and Communication Technology Research Group Scientific Research Center Al-Ayen University Nasiriyah 64001 Iraq Department of Mechanical Engineering College of Engineering University of Baghdad Baghdad Iraq Computational and Applied Mechanics Department Federal University of Juiz de Fora 36036-900 Brazil Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention and Guangdong Provincial Key Laboratory of Marine Biotechnology Shantou University Shantou 515063 China School of Computer and Information Qiannan Normal University for Nationalities Guizhou Duyun 558000 China Institute of Big Data Application and Artificial Intelligence Qiannan Normal University for Nationalities Guizhou Duyun 558000 China Faculty of Data Science and Information Technology INTI International University 71800 Malaysia

This study proposes different standalone models viz: Elman neural network (ENN), Boosted Tree algorithm (BTA), and f relevance vector machine (RVM) for modeling arsenic (As (mg/kg)) and zinc (Zn (mg/kg)) in marine sediments owing to anthropogenic activities. A heuristic algorithm based on the potential of RVM and a flower pollination algorithm (RVM-FPA) was developed to improve the prediction performance. Several evaluation indicators and graphical methods coupled with visualized cumulative probability function (CDF) were used to evaluate the accuracy of the models. Akaike (AIC) and Schwarz (SCI) information criteria based on Dickey-Fuller (ADF) and Philip Perron (PP) tests were introduced to check the reliability and stationarity of the data. The prediction performance in the verification phase indicated that RVM-M2 (PBAIS = -o.0465, MAE = 0.0335) and ENN-M2 (PBAIS = 0.0043, MAE = 0.0322) emerged as the best model for As (mg/kg) and Zn (mg/kg), respectively. In contrast with the standalone approaches, the simulated hybrid RVM-FPA proved merit and the most reliable, with a 5 % and 18 % predictive increase for As (mg/kg) and Zn (mg/kg), respectively. The study's findings validated the potential for estimating complex HMs through intelligent data-driven models and heuristic optimization. The study also generated valuable insights that can inform the decision-makers and stockholders for environmental management strategies. © 2024 Elsevier Ltd

关键词： Artificial intelligence Heavy metals Sensitivity analysis Soil contamination

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Reinforcement-learning-assisted nonreciprocal optomechanical gyroscope

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Physical Review A 2025年第6期111卷 063504-063504页

作者： Qing-Shou Tan Ya-Feng Jiao Yunlan Zuo Lan Xu Jie-Qiao Liao Le-Man Kuang Key Laboratory of Hunan Province on Information Photonics and Freespace Optical Communication College of Physics and Electronics Hunan Institute of Science and Technology Yueyang 414000 China School of Electronics and Information Zhengzhou University of Light Industry Zhengzhou 450001 China Academy for Quantum Science and Technology Zhengzhou University of Light Industry Zhengzhou 450002 China School of Physics and Chemistry Hunan First Normal University Changsha 410205 China Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Department of Physics and Synergetic Innovation Center for Quantum Effects and Applications Hunan Normal University Changsha 410081 China Institute of Interdisciplinary Studies Hunan Normal University Changsha Hunan 410081 China

We propose an optomechanical gyroscope architecture based on a spinning cavity optomechanical resonator evanescently coupled to a tapered optical fiber without relying on costly quantum light sources. Our study reveals a striking dependence of the gyroscope's sensitivity on the propagation direction of the driving optical field, manifesting robust quantum nonreciprocal behavior. This nonreciprocity significantly enhances the precision of the angular-velocity estimation, offering a unique advantage over conventional gyroscopic systems. Furthermore, we demonstrate that the operational range of this nonreciprocal gyroscope is fundamentally governed by the frequency of the pumping optical field, enabling localized sensitivity to angular velocity. Leveraging the adaptive capabilities of reinforcement learning (RL), we optimize the gyroscope's sensitivity within a targeted angular-velocity range, achieving unprecedented levels of precision. These results highlight the transformative potential of RL in advancing high-resolution, miniaturized optomechanical gyroscopes, opening new avenues for next-generation inertial sensing technologies.

关键词： Angular velocity

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