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基于改进Seq2Seq的船舶轨迹预测模型 被引量:1
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作者 唐家乐 段兴锋 姚鹏 《上海海事大学学报》 北大核心 2025年第2期18-22,共5页
针对传统循环神经网络(recurrent neural network,RNN)模型收敛速度慢、精度低,导致海上船舶预测轨迹与真实轨迹之间差别较大的问题,构建由RNN组成的Seq2Seq(sequence to sequence)模型。引入注意力机制和卷积神经网络(convolutional ne... 针对传统循环神经网络(recurrent neural network,RNN)模型收敛速度慢、精度低,导致海上船舶预测轨迹与真实轨迹之间差别较大的问题,构建由RNN组成的Seq2Seq(sequence to sequence)模型。引入注意力机制和卷积神经网络(convolutional neural network,CNN)对模型进行改进,加强对数据特征的提取能力,加快模型收敛速度并提高轨迹预测精度。实验结果显示:与传统RNN模型相比,Seq2Seq模型的均方误差、均方根误差和平均绝对误差分别降低81.41%、12.67%和62.43%;与Seq2Seq模型相比,改进Seq2Seq模型的均方误差、均方根误差和平均绝对误差分别降低42.87%、69.27%和45.79%。 展开更多
关键词 船舶轨迹预测 Seq2Seq(sequence to sequence) 注意力机制 卷积神经网络(CNN) 循环神经网络(RNN)
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马铃薯卷叶病毒56kD蛋白基因及3'端非编码区克隆和序列分析 被引量:6
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作者 张荣信 哈斯阿古拉 张鹤龄 《病毒学报》 CAS CSCD 北大核心 1997年第3期247-254,共8页
根据已报道的马铃薯卷叶病毒基因组序列,设计合成一对特异性引物。以马铃薯卷叶病毒中国分离株(PLRV-Ch)的RNA为模板,反转录合成了cDNA第一条链,经PCR扩增后克隆于pUC19质粒中。进一步用PCR鉴定,限制酶... 根据已报道的马铃薯卷叶病毒基因组序列,设计合成一对特异性引物。以马铃薯卷叶病毒中国分离株(PLRV-Ch)的RNA为模板,反转录合成了cDNA第一条链,经PCR扩增后克隆于pUC19质粒中。进一步用PCR鉴定,限制酶切分析和序列分析。结果表明,PLRV-Ch56kD蛋白基因由1527个核苷酸组成,编码508个氨基酸,3'端非编码区由141个核苷酸组成,与国外报道的苏格兰PLRV-S、荷兰PLRV-N、加拿大PLRV-C、澳大利亚PLRV-A各株系核苷酸序列和氨基酸序列有很高的同源性。56kD蛋白基因核苷酸同源率分别为97.1%、97.8%、97.1%和93.9%,推测的氨基酸同源率分别为96.2%、96.4%、95.8%和94.6%,非编码区核苷酸同源率分别为97.9%、97.2%、98.6%和98.6%。 展开更多
关键词 马铃薯卷叶病毒 56KD蛋白基因 3'端非编码区
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致密砂岩储层成岩过程及其与油气充注的关系——以鄂尔多斯盆地富县地区长8储层为例 被引量:12
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作者 丁超 郭顺 +1 位作者 郭兰 郭小波 《非常规油气》 2024年第4期29-38,共10页
储层致密化与油气充注的时间过程及其相互关系在勘探评价中具有关键作用。将铸体薄片观察、X射线衍射、扫描电镜及核磁共振相结合,细致分析了储层砂岩成岩过程与孔隙演化。结合已有油气成藏资料,综合建立了储层砂岩埋藏-成岩-孔隙演化-... 储层致密化与油气充注的时间过程及其相互关系在勘探评价中具有关键作用。将铸体薄片观察、X射线衍射、扫描电镜及核磁共振相结合,细致分析了储层砂岩成岩过程与孔隙演化。结合已有油气成藏资料,综合建立了储层砂岩埋藏-成岩-孔隙演化-油气充注的演化序列。结果表明:富县地区长8储层类型以长石砂岩和岩屑长石砂岩为主,孔喉关系复杂,为低-特低孔及特低-超低渗致密储层。早成岩阶段A期,长8储层经历机械压实(压溶)作用(Φ_(2)=21.6%),少量胶结物生成,距今192.5~152.0 Ma(J_(1)~K_(1)),Ⅰ期油气充注;早成岩阶段B期,大量胶结物生成(Φ_(3)=6.9%);中成岩阶段,距今152~126 Ma(K_(1)),Ⅱ期油气充注(主成藏阶段);晚期盆地构造抬升(Φ_(3)=10.8%),距今65.0~36.5 Ma(E_(1)),Ⅲ期油气充注。成岩过程导致油气充注的选择性与储层含油的差异性,研究成果对于寻找富县地区长8储层的“甜点区”具有重要的实际意义。 展开更多
关键词 富县地区 长8储层 成岩过程 孔隙演化 成藏时序
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乙烯装置热泵联锁保护系统改造
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作者 杨年青 石高峰 《乙烯工业》 CAS 2006年第4期44-47,共4页
10-K-650热泵机组自乙烯装置扩建投用以来,其联锁保护系统存在较多问题。该机组联锁保护由配套的PLC完成。由于维护人员对该套GE公司的PLC比较陌生,且其自身系统组态方面也不完整,机组在联锁方面遇到了很多无法确定及解决的难题。最后... 10-K-650热泵机组自乙烯装置扩建投用以来,其联锁保护系统存在较多问题。该机组联锁保护由配套的PLC完成。由于维护人员对该套GE公司的PLC比较陌生,且其自身系统组态方面也不完整,机组在联锁方面遇到了很多无法确定及解决的难题。最后决定用现有装置ESD系统来实现热泵机组的联锁保护。文中着重阐述了10-K-650热泵机组的联锁保护系统改造的原理及实现的过程。 展开更多
关键词 可编程逻辑控制器(Programmable Logic Controller) 分散控制系统(DCS:Distributed Control Systen) 紧急停车(EIlle唱f.ncy Shutdown) 事件记忆(sequence of Events) 联锁 旁路 数字量 模拟量
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用CS1000设计实现转化系统的停车联锁控制
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作者 胡红兵 《新疆化工》 2011年第2期40-43,48,共5页
新化公司拟在今后几年内,对转化系统的DCS控制系统进行更新。将现用的罗斯蒙特的RS3系统,更换为YOKOGAWA的CS1000/CS3000系统。本文阐述了用CS1000的顺控表模块(SequenceTableBlock)来实现转化系统停车联锁控制的组态过程。
关键词 顺控表(sequence TABLE Block) 转化停车联锁 组态
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The Prime Sequence: Demonstrably Highly Organized While Also Opaque and Incomputable-With Remarks on Riemann’s Hypothesis, Partition, Goldbach’s Conjecture, Euclid on Primes, Euclid’s Fifth Postulate, Wilson’s Theorem along with Lagrange’s Proof of It and Pascal’s Triangle, and Rational Human Intelligence
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作者 Leo Depuydt 《Advances in Pure Mathematics》 2014年第8期400-466,共67页
The main design of this paper is to determine once and for all the true nature and status of the sequence of the prime numbers, or primes—that is, 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, and so on. The ma... The main design of this paper is to determine once and for all the true nature and status of the sequence of the prime numbers, or primes—that is, 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, and so on. The main conclusion revolves entirely around two points. First, on the one hand, it is shown that the prime sequence exhibits an extremely high level of organization. But second, on the other hand, it is also shown that the clearly detectable organization of the primes is ultimately beyond human comprehension. This conclusion runs radically counter and opposite—in regard to both points—to what may well be the default view held widely, if not universally, in current theoretical mathematics about the prime sequence, namely the following. First, on the one hand, the prime sequence is deemed by all appearance to be entirely random, not organized at all. Second, on the other hand, all hope has not been abandoned that the sequence may perhaps at some point be grasped by human cognition, even if no progress at all has been made in this regard. Current mathematical research seems to be entirely predicated on keeping this hope alive. In the present paper, it is proposed that there is no reason to hope, as it were. According to this point of view, theoretical mathematics needs to take a drastic 180-degree turn. The manner of demonstration that will be used is direct and empirical. Two key observations are adduced showing, 1), how the prime sequence is highly organized and, 2), how this organization transcends human intelligence because it plays out in the dimension of infinity and in relation to π. The present paper is part of a larger project whose design it is to present a complete and final mathematical and physical theory of rational human intelligence. Nothing seems more self-evident than that rational human intelligence is subject to absolute limitations. The brain is a material and physically finite tool. Everyone will therefore readily agree that, as far as reasoning is concerned, there are things that the brain can do and things that it cannot do. The search is therefore for the line that separates the two, or the limits beyond which rational human intelligence cannot go. It is proposed that the structure of the prime sequence lies beyond those limits. The contemplation of the prime sequence teaches us something deeply fundamental about the human condition. It is part of the quest to Know Thyself. 展开更多
关键词 Absolute Limitations of Rational Human Intelligence Analytic Number Theory Aristotle’s Fundamental Axiom of Thought Euclid’s Fifth Postulate Euclid on Numbers Euclid on Primes Euclid’s Proof of the Primes’ Infinitude Euler’s Infinite Prime Product Euler’s Infinite Prime Product Equation Euler’s Product Formula Godel’s Incompleteness Theorem Goldbach’s Conjecture Lagrange’s Proof of Wilson’s Theorem Number Theory Partition Partition Numbers Prime Numbers (Primes) Prime sequence (sequence of the Prime Numbers) Rational Human Intelligence Rational Thought and Language Riemann’s Hypothesis Riemann’s Zeta Function Wilson’s Theorem
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SCAR Marker and Detection Technique of Bursaphelenchus xylophilus
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作者 Chen Fengmao Ye Jianren +2 位作者 Wu Xiaoqin Huang Lin Tang Jiajin 《Chinese Forestry Science and Technology》 2012年第3期84-84,共1页
OPM<sub>05</sub>-M<sub>2100</sub>,the specific RAPD fragment of Bursaphelenchus xylophilus,was collected from agarose gels and purified.Then,the purified fragment was inserted into the pGEM<... OPM<sub>05</sub>-M<sub>2100</sub>,the specific RAPD fragment of Bursaphelenchus xylophilus,was collected from agarose gels and purified.Then,the purified fragment was inserted into the pGEM<sup>R</sup> -T Vector that was transformed into Escherichia.coli and cloned and sequenced.Based on the sequence of RAPD marker,the sequences characterized amplified region(SCAR) primers were designed by the aid of the software Oligo5.0.The forward primer is M<sub>05</sub>F<sub>2</sub> (5’-CGGGT CATGG CTGGA GGTAT CGT-3’),and the backward primer is M<sub>05</sub>R<sub>1</sub>(5’-TGGCT CAATG GCAAA TCCTT CGTA-3’.The specific fragment (OPM<sub>05</sub>-M<sub>2100</sub>) was successfully converted to SCAR marker(SCAR-M<sub>05</sub>-X<sub>600</sub>) by using M<sub>05</sub> F<sub>2</sub>/R<sub>1</sub>,which was the specific markers of B.xylophilus.Then, the DNA of 92 isolates of Bursaphelenchus,B. mucronatus,B.hofmanni,Aphelenchoides macronucleatus and Seinura sp.which were isolated from dead pines,were marked,and the DNA of a single nematode extracted with a simple method was detected using this set of specific primers.The results indicated that the PCR product of all 81 isolates of B.xylophilus was a clear and bright fragment about 600 bp with M<sub>05</sub> F<sub>2</sub>/R<sub>1</sub>.But eight isolates of B. mucronatus,one B.hofmanni,one A.macronucleatus and one Seinura sp.had no any fragments.Assay M<sub>05</sub> F<sub>2</sub>/R<sub>1</sub> also successfully detected single pinewood nematode.Therefore,the specific pairwises would be used for constructing identification kits of B. xylophilus,implementing the aim of quick detection, and achieving the purpose of identify juvenile successfully. 展开更多
关键词 BURSAPHELENCHUS xylophilus SCAR MARKER SPECIFIC FRAGMENT detection technique SCAR(sequence characterized amplified region)
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