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The Journal of China Universities of Posts and Telecommunications 2018年第2期25卷 89-95页

作者： chen biyun Zhang Yerong Pan Xin College of Electronic Science and Engineering Nanjing University of Posts and Telecommunications School of Information Engineering Yancheng Teachers University Fuxin Branch Campus Aviation University of Air Force

The finite-difference time-domain （FDTD） method is extensively applied in dealing with time-domain microwave imaging（MWI） problems since it is robust, fast, simple to implement. However, the FDTD method is an explicit time-stepping technique, due to the constraint of the Courant-Friedrich-Levy （CFL） stability condition, the time step needs to be as small as the size of the fine cells, which brings a major increase in computational costs. A fast nonlinear electromagnetic reconstruction algorithm for layered loss-y media by using the alternating-direction implicit finite-difference time-domain （ADI-FDTD） method is proposed. This algorithm is based on an adjoint method, and the nonlinear iterations apply the ADI-FDTD method to calculate the forward and adjoint field, and adopt the Polak, Ribiere, Polyar conjugate-gradient （PRP-CG） optimization scheme. By comparing the simulation results based on ADI-FDTD method and the FDTD method, the validity and efficiency of the proposed algorithm have been proved. Furthermore, the relative residual errors （RRE） are introduced as the iterative computation termination conditions, which further prove the accuracy of this algorithm.

关键词： reconstruction algorithm ADI-FDTD MWI

Evaluation of Genetic and Epigenetic Modification in Rapeseed(Brassica napus)Induced by Salt Stress

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Journal of Integrative Plant Biology 2007年第11期49卷 1599-1607页

作者： Guangyuan Lu Xiaoming Wu biyun chen Guizhen Gao Kun Xu Brassica Germplasm Division Oil Crops Research Institute Chinese Academy of Agricultural Science Wuhan 430062 China

Salinity is an important limiting environmental factor for rapeseed production worldwide. In this study, we assessed the extent and pattern of DNA damages caused by salt stress in rapeseed plants. Amplified fragment length polymorphism （AFLP） analysis revealed dose-related increases in sequence alterations in plantlets exposed to 10-1000 mmol/L sodium chloride. In addition, individual plantlets exposed to the same salt concentration showed different AFLP and selected region amplified polymorphism banding patterns. These observations suggested that DNA mutation in response to salt stress was random in the genome and the effect was dose-dependant. DNA methylation changes in response to salt stress were also evaluated by methylation sensitive amplified polymorphism （MSAP）. Three types of MSAP bands were recovered. Type Ⅰ bands were observed with both isoschizomers Hpa Ⅱ and Msp Ⅰ, while type Ⅱ and type Ⅲ bands were observed only with Hpa Ⅱ and Msp Ⅰ, respectively. Extensive changes in types of MSAP bands after NaCI treatments were observed, including appearance and disappearance of type Ⅰ, Ⅱ and Ⅲ bands, as well as exchanges between either type Ⅰand type Ⅱ or type Ⅰ and type Ⅲ bands. An increase of 0.2-17.6% cytosine methylated CCGG sites were detected in plantlets exposed to 10- 200 mmol/L salt compared to the control, and these changes included both de novo methylation and demethylation events. Nine methylation related fragments were also recovered and sequenced, and one sharing a high sequence homology with the ethylene responsive element binding factor was identified. These results demonstrated clear DNA genetic and epigenetic alterations in planUets as a response to salt stress, and these changes may suggest a mechanism for plants adaptation under salt stress.

关键词： Brassica napus DNA-methylation genetic variation methylation sensitive amplified polymorphism salt stress.

Detection of DNA methylation changes during seed germination in rapeseed (Brassica napus)

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Chinese Science Bulletin 2006年第2期51卷 182-190页

作者： LU Guangyuan WU Xiaoming chen biyun GAO Guizhen XU Kun LI Xiangzhi Key Laboratory of Oil Crops Genetic Improvement of the Ministry of Agriculture Oil Crops Research Institute CAAS Wuhan 430062 China

DNA methylation is known to play a crucial role in regulating plant development and or- gan or tissue differentiation. In this study, we as- sessed the extent and pattern of cytosine methylation during rapeseed (Brassica napus L.) seed germina- tion, and compared the methylation level of various tissues in seedling, using the techniques of methyla- tion-sensitive amplified polymorphism (MSAP) and HPLC separation and quantification of nucleosides. In all, 484 bands, each representing a recognition site cleaved by either or both of the isoschizomers, were amplified by 12 pairs of selective primers in DNA ob- tained from dry seeds. A total of 76 sites were found to be differentially digested by the isoschizomers, indicating that approximately 15.7% of 5′-CCGG-3′ sites in the genome were cytosine methylated. Four classes of patterns were observed in a comparative assay of cytosine methylation in the dry and germi- nating seeds; a small number of hypermethylation events occurred at 5′-CCGG-3′ sites in germinating seeds compared with dry seeds, while many more hypomethylation events were detected after seed germination. Differences in DNA methylation level in various tissues were also detected; radicel was less methylated than hypocotyl and cotyledon. These observations were further confirmed by HPLC analy- sis. In addition, sequencing of eleven differentially methylated fragments and the subsequent blast search revealed that cytosine methylated 5′-CCGG- 3′ sequences were equally distributed between cod- ing and non-coding regions. These results clearly demonstrate the power of MSAP technique for large-scale DNA methylation detection in rapeseed genome, and the complexity of DNA methylationchange during seed germination. DNA Hypomethyla- tion going with seed germination appears to be a necessary step toward transcriptional activation in gene expression, and may well contribute to the de- velopmental gene regulation.

关键词：油菜籽芸苔属 DNA甲基化作用种子萌芽 MSAP HPLC

Prediction of Wordle Scores Based on ARIMA and LSTM Models

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Journal of Applied Mathematics and Physics 2024年第2期12卷 543-553页

作者： biyun chen Wenqiang Li College of Information Engineering Yancheng Teachers University Yancheng China

This paper examines the effectiveness of the Differential autoregressive integrated moving average (ARIMA) model in comparison to the Long Short Term Memory (LSTM) neural network model for predicting Wordle user-reported scores. The ARIMA and LSTM models were trained using Wordle data from Twitter between 7th January 2022 and 31st December 2022. User-reported scores were predicted using evaluation metrics such as MSE, RMSE, R2, and MAE. Various regression models, including XG-Boost and Random Forest, were used to conduct comparison experiments. The MSE, RMSE, R2, and MAE values for the ARIMA(0,1,1) and LSTM models are 0.000, 0.010, 0.998, and 0.006, and 0.000, 0.024, 0.987, and 0.013, respectively. The results indicate that the ARIMA model is more suitable for predicting Wordle user scores than the LSTM model.

关键词： Time Series ARIMA LSTM Wordle Prediction

An XPS Study of Nitrogen Structures in Soil Humic Substances

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Pedosphere 2001年第4期11卷 321-326页

作者： WEN QIXIAO, chenG LILI and chen biyun Institute of Soil Science, the Chinese Academy of Sciences, Nanjing 210008 (China) 中科院南京土壤所江苏南京 210008

X-ray photoelectron spectroscopy (XPS) was applied to examine the N structures of soil humic substances and some of their analogues. It was found that for soil humic substances XPS method gave similar results as those obtained by 15N CPMAS NMR (cross-polarization magic-angle spinning nuclear magnetic resonance) method. 70%～86% of total N in soil humic substances was in the form of amide, and 6%～13% was presented as amines, with the remaining part as heterocyclic N. There was no difference in the distribution of the forms of N between the humic substances from soils formed over hundreds or thousands of years and the newly formed ones. For fulvic acid from weathered coal and benzoqu inone- (N H-4 )-2 S O-4 polymer the XPS results deviated significantly from the 15N CPMAS NMR data.

关键词： distribution of N forms 15N CPMAS NMR soil humic substances XPS.

Intelligent In-Vehicle Safety System Based on Yolov5

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Journal of Computer and Communications 2024年第3期12卷 207-218页

作者： biyun chen Wei Cai Jinwen Zhu College of Computer Information and Engineering Yancheng Teachers University Yancheng China

In order to reduce the occurrence of traffic accidents and assist drivers to avoid dangerous driving. This paper presents a smart in-vehicle safety system that utilises the Yolov5 algorithm. Yolov5 algorithm is used to anticipate driver fatigue and distraction behaviours, and remind drivers to pay attention to safe driving in time. The system continuously splits the frames and analyses the frame content through the video feedback from the front camera, compared to the traditional machine learning, Yolov5’s mosaic data is enhanced, resulting in a batch size enhancement of 92.3%, and it also uses the Drop Block mechanism to prevent overfitting. The hardware of this system uses STM32 microcontroller and uses system DMA interrupt control and buzzer alarm device to warn about dangerous driving behaviour.

关键词： Behaviour Detection STM32 Pyside2 Yolov5 Dlib Open Source Library Perclos Model

Analysis of the Thyroid Carcinoma Incidence in Tianjin Over a Recent Twenty-Year Period

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Chinese Journal of Clinical Oncology 2005年第5期2卷 815-819页

作者： biyun Qian Kexin chen Min He Shufen Dong Haixin Li Fengju Song Department of Cancer Epidemiology Tianjin Medical University Cancer Institute and Hospital Tianjin 300060China.

OBJECTIVE To analyze the incidence rate and trend of thyroid cancer in Tianjin over a recent 20-year period. METHODS A method of descriptive epidemiology was used to study the occurrence of thyroid cancer. RESULTS During 1981-2001, the average incidence rate of thyroid cancer was 1.770 per 100,000 with a male to female incidence ratio of 1： 2.74, the occurrence being higher in females than in males. Thyroid cancer incidence increased gradually with time over the 20 years in both males and females, especially the incidence peaked in females of 35-50 years of age. CONCLUSION The rapid increase in the incidence rate of thyroid cancer, especially in females, suggests that further research on the risk factors and preventive efforts related to high-risk women should be conducted.

关键词： thyroid cancer epidemiology incidence rate time trend.

Characterization of Humic Fractions in a ^(15)N-labelled Soil by Solid-State ^(13)C and ^(15)N NMR

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Pedosphere 2001年第2期11卷 151-157页

作者： chenG LILI, WEN QIXIAO and chen biyun Institute of Soil Science, the Chinese Academy of Sciences, Nanjing 210008 (China)

Five humic fractions were obtained from a uniformly 15N-labelled soil by extraction with 0.1 mol L-1 Na4P207, 0.1 mol L-1 NaOH, and HF/HCI-0.1 mol L-1 NaOH, consecutively, and analyzed by 13C and 15N CPMAS NMR (cross polarization and magic angle spinning nuclear magnetic resonance). Compared with those of native soils humic fractions studied as a whole contained more alkyls, methoxyls and O-alkyls, being 27%-36%, 17%-21% and 36%-40%, respectively, but fewer aromatics and carboxyls (being 14%-20% and 13%-90%, respectively). Among those humic fractions, the humic acid (HA) and fulvic acid (FA) extracted by 0.1 mol L-1 Na4P207 contained slightly more carboxyls than corresponding humic fractions extracted by 0.1 mol L-1 NaOH, and the HA extracted by 0.1 mol L-1 NaOH after treatment with HF/HCI contained the least aromatics and carboxyls. The distribution of nitrogen functional groups of soil humic fractions studied was quite similar to each other and also quite similar to that of humic fraction from native soils. More than 75% of total N in each fraction was in amide form, with 9%-13% present as aromatic and/or aliphatic amines and the remainder as hoterocyclic N.

关键词： aromaticity 13C CPMAS NMR humic substances 15N CPMAS NMR nitrogen forms

Urban structure and the risk of influenza A(H1N1) outbreaks in municipal districts

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Chinese Science Bulletin 2014年第5期59卷 554-562页

作者： Hong Xiao Xiaoling Lin Gerardo Chowell Cunrui Huang Lidong Gao biyun chen Zheng Wang Liang Zhou Xinguang He Haining Liu Xixing Zhang Huisuo Yang College of Resources and Environment Science Hunan Normal University Mathematical Computational and Modeling Sciences CenterSchool of Human Evolution and Social Change Arizona State University Division of International Epidemiology and Population Studies Fogarty International Center National Institutes of Health Centre for Environment and Population Health School of Environment Griffith University Hunan Provincial Center for Disease Control and Prevention Department of Respiratory and Critical Care Medicine Beijing Institute of Respiratory Medicine Beijing Chaoyang Hospital Affiliated to Capital Medical University Changsha Municipal Center for Disease Prevention and Control Center for Disease Control and Prevention of Beijing Military Region

Changsha was one of the most affected areas during the 2009 A(H1N1)influenza pandemic in ***,we analyze the spatial–temporal dynamics of the 2009 pandemic across Changsha municipal districts,evaluate the relationship between case incidence and the local urban spatial structure and predict high-risk areas of influenza A(H1N1).We obtained epidemiological data on all cases of influenza A(H1N1)reported across municipal districts in Changsha during period May 2009–December 2010 and data on population density and basic geographic characteristics for 239 primary schools,97 middle schools,347 universities,96 malls and markets,674 business districts and 121 ***–temporal K functions,proximity models and logistic regression were used to analyze the spatial distribution pattern of influenza A(H1N1)incidence and the association between influenza A(H1N1)cases and spatial risk factors and predict the infection *** found that the 2009 influenza A(H1N1)was driven by a transmission wave from the center of the study area to surrounding areas and reported cases increased significantly after September *** also found that the distribution of influenza A(H1N1)cases was associated with population density and the presence of nearest public places,especially universities(OR=10.166).The final predictive risk map based on the multivariate logistic analysis showed high-risk areas concentrated in the center areas of the study area associated with high population *** findings support the identification of spatial risk factors and highrisk areas to guide the prioritization of preventive and mitigation efforts against future influenza pandemics.

关键词：风险图流感甲型城市结构 Logistic回归分析 logistic回归城市空间结构爆发

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应对极端灾害的韧性配电网自动开关优化配置

电力自动化设备 2019年第11期39卷 71-77页

作者：陈碧云陈灏颖李滨广西大学广西电力系统最优化与节能技术重点实验室

以台风灾害为例研究了考虑配电网抗灾韧性的自动开关优化配置模型。首先考虑台风风场、配电系统故障状态、系统负荷的不确定性,生成随机场景。其次分析台风灾害期间的配电网故障处理及供电恢复过程中的负荷区域供电状态,将自动开关优化... 详细信息

以台风灾害为例研究了考虑配电网抗灾韧性的自动开关优化配置模型。首先考虑台风风场、配电系统故障状态、系统负荷的不确定性,生成随机场景。其次分析台风灾害期间的配电网故障处理及供电恢复过程中的负荷区域供电状态,将自动开关优化配置问题进行建模,转换为两阶段的混合整数线性规划框架,第一阶段获取以投资运维费用和韧性成本的总费用最小为目标的自动开关配置方案,第二阶段求解以台风期间系统韧性指标最小为目标的负荷区域供电状态。最后,以IEEE 33节点系统为算例进行仿真分析,仿真结果表明所提出的模型应用自动开关配置方案后,具有较好的经济效益和韧性提升效率。

关键词：配电网韧性自动开关优化规划台风灾害