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Attention-based spatio-temporal graph convolutional network considering external factors for multi-step traffic flow prediction

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Digital Communications and Networks 2022年第3期8卷 343-350页

作者： Jihua ye Shengjun Xue Aiwen jiang School of Computer and Information Engineering Jiangxi Normal UniversityNanchang330022China

Traffic flow prediction is an important part of the intelligent transportation system. Accurate multi-step traffic flow prediction plays an important role in improving the operational efficiency of the traffic network. Since traffic flow data has complex spatio-temporal correlation and non-linearity, existing prediction methods are mainly accomplished through a combination of a Graph Convolutional Network (GCN) and a recurrent neural network. The combination strategy has an excellent performance in traffic prediction tasks. However, multi-step prediction error accumulates with the predicted step size. Some scholars use multiple sampling sequences to achieve more accurate prediction results. But it requires high hardware conditions and multiplied training time. Considering the spatiotemporal correlation of traffic flow and influence of external factors, we propose an Attention Based Spatio-Temporal Graph Convolutional Network considering External Factors (ABSTGCN-EF) for multi-step traffic flow prediction. This model models the traffic flow as diffusion on a digraph and extracts the spatial characteristics of traffic flow through GCN. We add meaningful time-slots attention to the encoder-decoder to form an Attention Encoder Network (AEN) to handle temporal correlation. The attention vector is used as a competitive choice to draw the correlation between predicted states and historical states. We considered the impact of three external factors (daytime, weekdays, and traffic accident markers) on the traffic flow prediction tasks. Experiments on two public data sets show that it makes sense to consider external factors. The prediction performance of our ABSTGCN-EF model achieves 7.2%–8.7% higher than the state-of-the-art baselines.

关键词： Multi-step traffic flow prediction Graph convolutional network External factors Attentional encoder network Spatiotemporal correlation

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DZY-C型三叉神经立体定向仪的临床应用

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中华神经医学杂志 2005年第6期4卷 612-613页

作者：陈小华江野峰庄志浩何锦梁庆新广东省佛山市中医院神经外科 528000

目的总结应用DZY-C型三叉神经立体定向仪对120例三叉神经痛患者的治疗,寻求治疗三叉神经痛的良好方法。方法将病人头部固定在定向仪上,用普通X线机摄取颅底片及侧位片,测算卵圆孔的位置,在定向仪的引导下穿刺针经卵圆孔进入三叉神经半... 详细信息

目的总结应用DZY-C型三叉神经立体定向仪对120例三叉神经痛患者的治疗,寻求治疗三叉神经痛的良好方法。方法将病人头部固定在定向仪上,用普通X线机摄取颅底片及侧位片,测算卵圆孔的位置,在定向仪的引导下穿刺针经卵圆孔进入三叉神经半月节及三叉神经节池,注射甘油治疗原发性三叉神经痛。结果穿刺治疗120例三叉神经痛患者,一次性穿刺的成功率高达99.17%。结论应用立体定向仪定向穿刺,可将凭借经验性的不确定的穿刺变为标准化的穿刺,较徒手穿刺更具科学性。

关键词： DZY-C型三叉神经立体定向仪临床应用原发性三叉神经痛普通X线机三叉神经节甘油治疗穿刺治疗定向穿刺徒手穿刺侧位片颅底片半月节卵圆孔一次性标准化不确定经验性科学性患者

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Reaction network design and hybrid modeling of S Zorb

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Chinese Journal of Chemical Engineering 2024年第9期73卷 301-310页

作者： Kai Ji Zhencheng ye feng Qian Key Laboratory of Smart Manufacturing in Energy Chemical Process Ministry of EducationEast China University of Science and TechnologyShanghai 200237China Qingyuan Innovation Laboratory Quanzhou 362801China

At present,many countries are becoming more and more stringent in terms of sulfur content in fuel oil.S Zorb is a kind of desulfurization technology with advantages of exceptional desulfurization efficiency and small impact on octane *** meet the needs of environmental requirements and the trend of digitalization in the petrochemical industry,a first-principle model of S Zorb was established based on industry *** order to describe the desulfurization and the other side reactions,a reaction network was designed and the kinetic parameters were estimated by the particle swarm optimization *** hybrid models based on the first-principle model and support vector regression method were established to correct the mass fraction of sulfur and predict the research octane number of the refined gasoline *** results indicate that the hybrid models can predict the mass fraction of PIONA,sulfur content and research octane number of the refined gasoline accurately,of which the mean absolute percentage errors are less than 6%.Hybrid models were then applied to optimize the decision variables to minimize the research octane number *** results show that the average reduction of the loss of research octane number is 21.8%,which suggests that the models developed hold promise for guiding practical production.

关键词： Desulfurization Simulation Reaction kinetics Optimization

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Biomimetic photoelectric conversion systems based on artificial membranes

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Science China Chemistry 2011年第4期54卷 603-610页

作者： TIAN ye jiang Lei Center for Molecular Science Institute of ChemistryChinese Academy of SciencesBeijing 100190China

Biological light-driven proton pumps which could transfer light energy to electrical energy have aroused intense interest in the past *** related researches have been conducted to mimic this process in vitro because of its potential significant *** review describes the progress in biomimetic photoelectric conversion systems based on different kinds of promising artificial *** biological bacteriorhodopsin and the photosensitive chemical molecules which could be used to achieve the photoelectric conversion function are *** a short outlook in this field is demonstrated at the end.

关键词： biomimetic photoelectric conversion artificial membranes bacteriorhodopsin photosensitive chemical molecules

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基于手机信令数据的广州市居民公园访问行为空间分异及其影响因素分析

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中山大学学报（自然科学版）（中英文） 2025年第1期64卷 195-206页

作者：刘晔叶柏麟吴景豪中山大学地理科学与规划学院广东广州510006 广东省公共安全与灾害工程技术研究中心/广东省城市化与地理环境空间模拟重点实验室广东广州510006

加快推进城市公园建设是实现人与自然和谐共生的重要抓手。既有研究大多基于问卷调查数据和访谈资料分析城市居民的公园访问行为空间分异特征,研究结论的普适性和科学性有限。手机信令数据具有大样本、覆盖范围广、信息被动提供和动态... 详细信息

加快推进城市公园建设是实现人与自然和谐共生的重要抓手。既有研究大多基于问卷调查数据和访谈资料分析城市居民的公园访问行为空间分异特征,研究结论的普适性和科学性有限。手机信令数据具有大样本、覆盖范围广、信息被动提供和动态实时性强等优点。利用手机信令数据精准刻画城市居民的公园访问行为,有助于开展城市公园的布局优化与品质提升工作。基于个体尺度的手机信令数据,本研究试图揭示广州市居民公园访问行为的空间分异特征并识别其影响因素,尤其关注城区居民和郊区居民的差别。结果表明:(1)城区居民的公园访问频率、公园访问时长和公园访问强度均高于郊区居民,前者的公园平均访问距离低于后者;(2)公园访问频率、公园访问强度、公园平均逗留时间和公园平均访问距离呈现高值集聚区/低值集聚区在城区连片分布,在郊区零星分布的空间特征;(3)公园访问行为受性别、年龄、时空约束性、社会经济地位、公园可达性、社区出行便利性和出行适宜性等因素的共同影响。本研究为相关政府部门精准开展城市公园的规划、建设与管理工作提供决策参考。

关键词：城市公园公园访问行为空间分异手机信令数据广州

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Soil Microbial Activity During Secondary Vegetation Succession in Semiarid Abandoned Lands of Loess Plateau

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Pedosphere 2009年第6期19卷 735-747页

作者： jiang Jin-Ping XIONG You-Cai jiang Hong-Mei ye De-You SONG Ya-Jie LI feng-Min Key Laboratory of Arid and Grassland Ecology of Education Ministry of China School of Life Sciences Lanzhou University Lanzhou 730000 (China) Key Laboratory of Arid and Grassland Ecology of Education Ministry of China School of Resources and Environment Science Lanzhou University Lanzhou 730000 (China) Gansu Academy of Agricultural Science Lanzhou 730070 (China) Key Laboratory of Soil Environment and Pollution Remediation Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 (China) School of Forestry and Environment Studies Yale University New Haven CT06511 (USA)

To show the vegetation succession interaction with soil properties, microbial biomass, basal respiration, and enzyme activities in different soil layers （0-60 cm） were determined in six lands, i.e., 2-, 7-, 11-, 20-, and 43-year-old abandoned lands and one native grassland, in a semiarid hilly area of the Loess Plateau. The results indicated that the successional time and soil depths affected soil microbiological parameters significantly. In 20-cm soil layer, microbial biomass carbon （MBC）, microbial biomass nitrogen （MBN）, MBC/MBN, MBC to soil organic carbon ratio （MBC/SOC）, and soil basal respiration tended to increase with successional stages but decrease with soil depths. In contrast, metabolic quotient （qCO2） tended to decrease with successional stages but increase with soil depths. In addition, the activities of urease, catalase, neutral phosphatase, β-fructofuranosidase, and earboxymethyl cellulose （CMC） enzyme increased with successional stages and soil depths. They were significantly positively correlated with microbial biomass and SOC （P 〈 0.5）, whereas no obvious trend was observed for the polyphenoloxidase activity. The results indicated that natural vegetation succession could improve soil quality and promote ecosystem restoration, but it needed a long time under local climate conditions.

关键词： microbial biomass carbon microbial biomass nitrogen SOC soil enzyme activity

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Effect of agarose content on microstructures and mechanical properties of porous silicon nitride ceramics produced by gelcasting

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第10期11卷 771-775页

作者： Jing-yi ZHANG feng ye School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China

Porous Si3N4 self-reinforce ceramics were prepared by gelcasting using agarose solutions. By changing the agarose content in the slurries, the porous silicon nitride ceramics with different porosities, α→β-Si3N4 phase transformation, and mechanical properties were obtained. When the agarose content changed from 0.2% to 0.8% (w/w, based on powder), the porosities increased from 10.3% to 21.4%, while the fracture strength decreased from 455 to 316 MPa and the fracture toughness decreased from 6.6 to 5.5 MPa·m1/2. Many fibrous β-Si3N4 grains grown from the internal wall of the round pores is the typical microstructure of the gelcasting porous silicon nitride ceramic. Both elongated β-Si3N4 grains and suitable interfacial bonding strength contributes to high fracture toughness by favoring crack deflection and bridging. The growth mechanisms of fibrous grains resulted from the synergy of solution-diffusion-reprecipitation and vapor-liquid-solid (VLS).

关键词： Porous Si3N4 ceramics Gelcasting Microstructure Mechanical properties

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Optimal antenna placement in distributed antenna systems

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Journal of Systems Engineering and Electronics 2012年第4期23卷 467-472页

作者： Zhongzhao Zhang Zhun ye Weilin jiang School of Electronics and Information Engineering Harbin Institute of TechnologyHarbin 150080R R.China

To minimize the outage probability of the cell （OPC） in downlink distributed antenna systems with selection transmission, a complex-encoding genetic algorithm （GA） is proposed to find the optimal locations of the antenna elements （AEs）. First, the outage probability at a fixed location in the cell is investigated. Next, an analytical expression of the OPC is derived, which is a function of the AE locations. Then the OPC is used as the objective function of the antenna placement optimization problem, and the complex- encoding GA is used to find the optimal AE locations in the cell. Numerical results show that the optimal AE locations are symmetric about the cell center, and the outage probability contours are also given with the optimal antenna placement. The algorithm has a good convergence and can also be used to determine the number of AEs which should be installed in order to satisfy the certain OPC value. Lastly, verification of the OPC＇s analytical expression is carried out by Monte Carlo simulations. The OPC with optimal AE locations is about 10% lower than the values with completely random located AEs.

关键词： distributed antenna system (DAS) outage probability,genetic algorithm (GA).

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Fast approximate maximum likelihood period estimation from incomplete timing data

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Chinese Journal of Aeronautics 2013年第2期26卷 435-441页

作者： ye Haohuan Liu Zheng jiang Wenli College of Electronic Science & Engineering National University of Defense Technology

To estimate the period of a periodic point process from noisy and incomplete observations, the classical periodogram algorithm is modified. The original periodogram algorithm yields an estimate by performing grid search of the peak of a spectrum, which is equivalent to the periodogram of the periodic point process, thus its performance is found to be sensitive to the chosen grid spacing. This paper derives a novel grid spacing formula, after finding a lower bound of the width of the spectral mainlobe. By employing this formula, the proposed new estimator can determine an appropriate grid spacing adaptively, and is able to yield approximate maximum likelihood estimate （MLE） with a computational complexity of O（n2）. Experimental results prove that the proposed estimator can achieve better trade-off between statistical accuracy and complexity, as compared to existing methods. Simulations also show that the derived grid spacing formula is also applicable to other estimators that operate similarly by grid search.

关键词： Grid search Maximum likelihood period estimation Periodic point process Periodogram Pulse repetition frequency

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Influence of matrigel on the shape and dynamics of cancer cells

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Chinese Physics B 2019年第10期28卷 222-225页

作者： Teng ye feng Qiu First Clinical Medical College Nanchang UniversityNanchang 330006China Department of Oncology First Affiliated Hospital of Nanchang UniversityNanchang 330006China

The interaction between extracellular matrices and cancer cells plays an important role in regulating cancer cell behaviors. In this article, we use matrigel to mimic extracellular matrices and investigate experimentally how matrigel influences the shape and dynamics of breast cancer cells(MDA-MB-231-GFP cells). We find that matrigel facilitates cancer cells' migration and shape deformation. The influences of the matrigel concentration are also reported.

关键词： cancer cell matrigel migration shape deformation

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