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Towards Accurate bit Error Simulation in Wireless Sensor Networks Including Environmental Influences

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Journal of Computer Science & Technology 2020年第4期35卷 809-824页

作者： Sven Pullwitt Robert Hartung Ulf Kulau Lars Wolf Institute for Operating Systems and Computer Networks Technische Universitat BraunschweigBraunschweig 38106 Germany

Simulation is a common technique for the evaluation of new approaches and protocols in networked systems and provides many benefits.However,it is also well known that the relevance of the simulation results for real-world applications depends on the various models which are used within the simulation,e.g.,for the characteristics of the radio communication.In this paper,we introduce the Extended Multipath Raytracing Model,an extension to the ray-tracing radio medium available in Cooja,to improve the modelling of wireless links in simulated Wireless Sensor Networks.Our extension allows the simulation of environmental influences onto links on a per node basis,allowing the analysis of various effects observed in experiments in a virtual environment.Furthermore,the packet-based modelling of transmission errors is extended to provide the simulation of bit errors,allowing new usage scenarios,like the simulation of error detection and Forward Error Correction codes in Cooja.

关键词： bit error Contiki Cooja environmental influence simulation wireless sensor network

Test results judgment method based on bit faults

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Chinese Journal of Aeronautics 2015年第6期28卷 1650-1657页

作者： Wang Gang Qiu Jing Liu Guanjun Lyu Kehong Science and Technology on Integrated Logistics Support Laboratory National University of Defense Technology College of Mechatronics and Automation National University of Defense Technology

Built-in-test （bit） is responsible for equipment fault detection, so the test data correct- ness directly influences diagnosis results. Equipment suffers all kinds of environment stresses, such as temperature, vibration, and electromagnetic stress. As embedded testing facility, bit also suffers from these stresses and the interferences/faults are caused, so that the test course is influenced, resulting in incredible results. Therefore it is necessary to monitor test data and judge test failures. Stress monitor and bit self-diagnosis would redound to bit reliability, but the existing anti- jamming researches are mainly safeguard design and signal process. This paper focuses on test results monitor and bit equipment （bitE） failure judge, and a series of improved approaches is proposed. Firstly the stress influences on components are illustrated and the effects on the diagnosis results are summarized. Secondly a composite bit program is proposed with information integra- tion, and a stress monitor program is given. Thirdly, based on the detailed analysis of system faults and forms of bit results, the test sequence control method is proposed. It assists bitE failure judge and reduces error probability. Finally the validation cases prove that these approaches enhance credibility.

关键词： bit Composite bit program Stress monitor Test course Test sequence control

Soil pH impact on microbial tetraether lipids and terrestrial input index (bit) in China

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Science China Earth Sciences 2012年第2期55卷 236-245页

作者： YANG Huan DING WeiHua WANG JinXiang JIN ChengSheng HE GangQiang QIN YangMin XIE ShuCheng State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences Wuhan 430074 China State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Wuhan 430074 China

The distributions of microbial tetraether lipids i.e. glycerol dialkyl glycerol tetraethers (GDGTs) were investigated in a variety of Chinese soils featured by a wide range of pH values in different climate zones. The bacterial branched GDGTs and archaeal isoprenoid GDGTs were found to be widely distributed in Chinese soils and their relative abundance was controlled primarily by soil pH. The bacterial bGDGTs usually dominate over archaeal iGDGTs in abundance when the soil pH is below 8.0. However archaeal iGDGTs become dominant and the abundance of halophilic archaea characterized by GDGT V without cyclopentyl ring increases dramatically in the alkaline soil with pH greater than 8.0. The relative abundance of archaeal iGDGTs to bacterial bGDGTs was defined here as RAI index. The RAI index decreases with elevated soil pH and a linear correlation is found between them indicating that the relative abundance of archaeal iGDGTs to bacterial bGDGTs increases with increased pH. The RAI index thus could be a novel proxy of the pH values of paleosol. The terrestrial input index bit (Branched and Isoprenoid Tetraethers Index) decreases with increased soil pH suggesting that soil pH should be taken into consideration when the terrestrial contribution to marine sediments is estimated by bit index. Moreover the TEX86 index cannot be used to reconstruct sea surface temperature in the sediments featured by a large terrestrial input.

关键词： pH值控制土壤微生物中国土壤输入功能陆地 bit 土壤pH值海洋沉积物

QUANTIZATION AND TRAINING OF LOW bit-WIDTH CONVOLUTIONAL NEURAL NETWORKS FOR OBJECT DETECTION

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Journal of Computational Mathematics 2019年第3期37卷 349-359页

作者： Penghang Yin Shuai Zhang Yingyong Qi Jack Xin Department of Mathematics University of CaliforniaLos AngelesCA 90095USA Department of Mathematics University of CaliforniaIrvineCA 92697USA

We presen t LBW-Net,an efficient optimization based method for qua nt ization and training of the low bit-width convolutional neural networks(CNNs).Specifically,we quantize the weights to zero or powers of 2 by minimizing the Euclidean distance between full-precision weights and quantized weights during backpropagation(weight learning).We characterize the combinatorial nature of the low bit-width quantization problem.For 2-bit(ternary)CNNs,the quantization of N weights can be done by an exact formula in O(N log N)complexity.When the bit-width is 3 and above,we further propose a semi-analytical thresholding scheme with a single free parameter for quantization that is computationally inexpensive.The free parameter is further determined by network retraining and object detection tests.The LBW-Net has several desirable advantages over full-precision CNNs,including considerable memory savings,energy efficiency,and faster deployment.Our experiments on PASCAL VOC dataset show that compared with its 32-bit floating-point counterpart,the performance of the 6-bit LBW-Net is nearly lossless in the object detection tasks,and can even do better in real world visual scenes,while empirically enjoying more than 4× faster deployment.

关键词： Quantization Low bit width deep neural networks Exact and approximate analytical formulas Network training Object detection

Performance analysis and design of MIMO-OFDM system using concatenated forward error correction codes

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Journal of Central South University 2017年第6期24卷 1322-1343页

作者： Arun Agarwal Saurabh N.Mehta PhD Scholar School of Electrical EngineeringDepartment of Information TechnologyAMET UniversityTamil NaduChennai 603112India Department of Electronics and Telecommunication Engineering Vidyalankar Institute of TechnologyMumbai-400037MaharashtraIndia

This work investigates the performance of various forward error correction codes, by which the MIMO-OFDM system is deployed. To ensure fair investigation, the performance of four modulations, namely, binary phase shift keying(BPSK), quadrature phase shift keying(QPSK), quadrature amplitude modulation(QAM)-16 and QAM-64 with four error correction codes(convolutional code(CC), Reed-Solomon code(RSC)+CC, low density parity check(LDPC)+CC, Turbo+CC) is studied under three channel models(additive white Guassian noise(AWGN), Rayleigh, Rician) and three different antenna configurations(2×2, 2×4, 4×4). The bit error rate(BER) and the peak signal to noise ratio(PSNR) are taken as the measures of performance. The binary data and the color image data are transmitted and the graphs are plotted for various modulations with different channels and error correction codes. Analysis on the performance measures confirm that the Turbo + CC code in 4×4 configurations exhibits better performance.

关键词： bit error rate (BER) convolutional code (CC) forward error correction peak signal to noise ratio (PSNR) Turbo code

Use of a coded voltage signal for cable switching and fault isolation in cabled seafloor observatories

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Frontiers of Information Technology & Electronic Engineering 2018年第11期19卷 1328-1339页

作者： Zhi-feng ZHANG Yan-hu CHEN De-jun LI Bo JIN Can-jun YANG Jun WANG State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang University

Cabled seafloor observatories play an important role in ocean exploration for its long-term, real-time, and in-situ observation characteristics. In establishing a permanent, reliable, and robust seafloor observatory, a highly reliable cable switching and fault isolation method is essential. After reviewing the advantages and disadvantages of existing switching methods, we propose a novel active switching method for network configuration. Without additional communication path requirements, the switching method provides a way to communicate with a shore station through an existing power transmission path. A coded voltage signal with a distinct sequence is employed as the communication medium to transmit commands. The analysis of the maximum bit frequency of the voltage signals guarantees the accuracy of command recognition. A prototype based on the switching method is built and tested in a laboratory environment, which validated the functionality and reliability of the method.

关键词： Cabled seafloor observatories Cable switching and fault isolation Coded voltage signal Maximum bit frequency

Performance Analysis of AF Relaying Aided Space Shift Keying System with Imperfect Channel Estimation

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Transactions of Nanjing University of Aeronautics and Astronautics 2018年第6期35卷 1038-1046页

作者： Pan Qing Yu Xiangbin Hu Yaping Wang Xi Wang Cheng College of Electronic and Information Engineering Nanjing University of Aeronautics and Astronautics

Space shift keying (SSK) is a spectrally efficient and low-complexity technique that only uses antenna index to convey information.Combining SSK with cooperative communication,the transmission reliability of SSK system can be improved effectively.In this paper,considering imperfect channel information,the performance of cooperative SSK system with amplify-and-forward (AF) relaying protocol is investigated,and the effect of estimation error on the performance is analyzed.According to the performance analysis,the probability density function and moment generating function of effective signal-to-noise ratio are derived,respectively.Using these results,the closed-form expression of average bit error rate (BER) can be achieved.Meanwhile,the asymptotically approximated BER and the corresponding diversity order analysis are presented for the performance evaluation.By computer simulations,the validness of the presented theoretical analysis is verified,and the theoretical BERs with different estimation errors are shown to be close to those of the corresponding simulations.

关键词： space shift keying amplify-and-forward channel-estimation error bit error rate diversity order

接枝bit的有机硅基丙烯酸防污树脂的制备和性能研究

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涂料工业 2023年第10期53卷 1-7页

作者：刘礼菊董苗王大壮刘若彤林心蕊张苹薛行华杨建新海口市绿色催化与反应工程重点实验室海南大学理学院海口570228 海南大学生态与环境学院海口570228

将有机硅材料和防污剂共聚接枝到丙烯酸树脂中,制备了一种接枝bit(1,2-苯并异噻唑啉-3-酮)的、具有协同防污机制的有机硅基丙烯酸防污树脂。通过红外光谱、凝胶渗透色谱对树脂的结构和相对分子质量进行测定,并对树脂分别进行了接触角、... 详细信息

将有机硅材料和防污剂共聚接枝到丙烯酸树脂中,制备了一种接枝bit(1,2-苯并异噻唑啉-3-酮)的、具有协同防污机制的有机硅基丙烯酸防污树脂。通过红外光谱、凝胶渗透色谱对树脂的结构和相对分子质量进行测定,并对树脂分别进行了接触角、静态海水浸泡质量损失、抑藻性能测试以及实海挂板实验。结果表明:树脂表面接触角随着有机硅含量的增加而增加;在海水中,接枝到树脂上的bit-W可以缓慢稳定地释放,其质量损失曲线近似呈线性变化,平均质量损失在0.03~0.09 mg之间;树脂对旋链角毛藻和小球藻均具有良好的抑制作用,调整bit-W含量使得树脂对2种藻类的抑制率分别达到了70.8%和82.7%。此研究中的防污树脂合成方法简单、原料成本低廉,同时引入防污剂和有机硅基材料,赋予防污树脂在静态水和动态水中良好的防污性能。

关键词： bit 有机硅丙烯酸海洋防污

Performance Analysis of Non-Identically Distributed FSO Systems with Dual- and Triple- Branch Based on MRC over Gamma-Gamma Fading Channels

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China Communications 2018年第1期15卷 45-51页

作者： Tao Liu Hailin Zhang Jiaoying Wang Huihua Fu Ping Wang Jing Li State Key Laboratory of Integrated Service Networks School of Telecommunications Engineering Xidian University Xi'an 710071 China Xi'an Institute of Applied Optics Xi'an 71007 l China

In this work, the performance of free-space optical(FSO) communication system based on maximal ratio combining using binary phase shift keying subcarrier intensity modulation over Gamma-Gamma fading channels has been studied systematically. Under identically or non-identically distributed branches, the analytical expressions for the bit error rate function of signal-to-noise are derived by expressing the modified Bessel function of second kind with Meijer G-function for dualand triple-branch systems, respectively. In terms of H-fox function, the new expressions have more general forms and are more efficient for computation. It is found that the dual-and triple-branch systems significantly outperform the direct link system under weak, moderate and strong turbulence conditions. Monte Carlo simulation is also provided to confirm the accuracy of the proposed model.

关键词： bit error rate dual-and triple-branch flee-space optical systems Gamma-Gamma fad-ing maximal ratio combining (MRC)