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基于Filter Encoding的GML空间数据查询 被引量:3
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作者 苗立志 张书亮 +2 位作者 伍蓝 闾国年 焦东来 《计算机工程》 CAS CSCD 北大核心 2008年第3期59-61,共3页
随着地理数据网络化程度的提高和GML空间数据的应用越来越广泛,如何从海量的GML空间数据中检索出符合特定条件的地理要素数据成为目前GML研究的焦点问题之一。该文根据OGC制定的过滤编码执行规程,应用规程中的谓词作为查询关键字,结合GM... 随着地理数据网络化程度的提高和GML空间数据的应用越来越广泛,如何从海量的GML空间数据中检索出符合特定条件的地理要素数据成为目前GML研究的焦点问题之一。该文根据OGC制定的过滤编码执行规程,应用规程中的谓词作为查询关键字,结合GML空间数据的特点,通过查询转译器和优化器实现了一种应用于GML空间数据查询的可行性方法。 展开更多
关键词 查询转译器 查询优化器 过滤编码
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Fast encoding algorithm for vector quantization based on subvector L_2-norm 被引量:1
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作者 Chen Shanxue Li Fangwei Zhu Weile 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2008年第3期611-617,共7页
A fast encoding algorithm based on the mean square error (MSE) distortion for vector quantization is introduced. The vector, which is effectively constructed with wavelet transform (WT) coefficients of images, can... A fast encoding algorithm based on the mean square error (MSE) distortion for vector quantization is introduced. The vector, which is effectively constructed with wavelet transform (WT) coefficients of images, can simplify the realization of the non-linear interpolated vector quantization (NLIVQ) technique and make the partial distance search (PDS) algorithm more efficient. Utilizing the relationship of vector L2-norm and its Euclidean distance, some conditions of eliminating unnecessary codewords are obtained. Further, using inequality constructed by the subvector L2-norm, more unnecessary codewords are eliminated. During the search process for code, mostly unlikely codewords can be rejected by the proposed algorithm combined with the non-linear interpolated vector quantization technique and the partial distance search technique. The experimental results show that the reduction of computation is outstanding in the encoding time and complexity against the full search method. 展开更多
关键词 image compression fast encoding subvector wavelet transform vector quantization.
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Dynamic matrix encoding strategy for voice-over-IP steganography 被引量:5
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作者 田晖 周可 冯丹 《Journal of Central South University》 SCIE EI CAS 2010年第6期1285-1292,共8页
In order to optionally regulate embedding capacity and embedding transparency according to user's requirements in voice-over-IP(VoIP) steganography,a dynamic matrix encoding strategy(DMES) was presented.Differing ... In order to optionally regulate embedding capacity and embedding transparency according to user's requirements in voice-over-IP(VoIP) steganography,a dynamic matrix encoding strategy(DMES) was presented.Differing from the traditional matrix encoding strategy,DMES dynamically chose the size of each message group in a given set of adoptable message sizes.The appearance possibilities of all adoptable sizes were set in accordance with the desired embedding performance(embedding rate or bit-change rate).Accordingly,a searching algorithm that could provide an optimal combination of appearance possibilities was proposed.Furthermore,the roulette wheel algorithm was employed to determine the size of each message group according to the optimal combination of appearance possibilities.The effectiveness of DMES was evaluated in StegVoIP,which is a typical covert communication system based on VoIP.The experimental results demonstrate that DMES can adjust embedding capacity and embedding transparency effectively and flexibly,and achieve the desired embedding performance in any case.For the desired embedding rate,the average errors are not more than 0.000 8,and the standard deviations are not more than 0.002 0;for the desired bit-change rate,the average errors are not more than 0.001 4,and the standard deviations are not more than 0.002 6. 展开更多
关键词 STEGANOGRAPHY embedding transparency dynamic matrix encoding strategy voice over IP
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Therapeutic effect of intravesical or intratumoral injection of oncolysate transfected with recombinant vaccinia virus encoding human IL-2 gene on murine melanoma model 被引量:1
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作者 Bruce Acres 《中国实验血液学杂志》 CAS CSCD 1997年第3期317-317,共1页
Oncolysate, a debris of tumor cells, has been provento be effective in tumor active immunotherapy, it wasreported that the vaccinia virus, especially recombinantvaccinia viruses encoding human IL-2 (rVV-IL-2 ),enhance... Oncolysate, a debris of tumor cells, has been provento be effective in tumor active immunotherapy, it wasreported that the vaccinia virus, especially recombinantvaccinia viruses encoding human IL-2 (rVV-IL-2 ),enhanced the immunogenicity of transfected tumor cells.In this experiment, the murine melanoma cell B16-F10oncolysates trans fected by rVV-IL-2 (IL-2VBO) wereused as vaccine. The IL-2VBO or TK-VBO was preparedby incubating B16-F10 cells with rVV-IL-2 or rVV-TK 展开更多
关键词 MELANOMA encoding immunotherapy DEBRIS MURINE vaccine PROLONGED inhibited cytotoxicity markedly
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苹果NBS-encoding基因对斑点落叶病菌侵染的表达响应 被引量:2
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作者 童月霞 胡晓璇 +1 位作者 程宗明 仲岩 《南京农业大学学报》 CAS CSCD 北大核心 2019年第2期253-260,共8页
[目的]本文旨在分析苹果差异表达NBS-encoding基因的特征,挖掘在苹果斑点落叶病菌侵染过程中的潜在响应基因。[方法]通过苹果斑点落叶病菌侵染‘红星’后的RNA-seq数据筛选出差异表达的NBS-encoding基因,并利用ProtParam、Pfam、SMART... [目的]本文旨在分析苹果差异表达NBS-encoding基因的特征,挖掘在苹果斑点落叶病菌侵染过程中的潜在响应基因。[方法]通过苹果斑点落叶病菌侵染‘红星’后的RNA-seq数据筛选出差异表达的NBS-encoding基因,并利用ProtParam、Pfam、SMART等网站分析了其理化性质;利用R studio软件构建表达热图并分析其表达模式;利用Fast Tree 2软件构建苹果NBS-encoding基因家族的系统进化树,并利用MEGA 6.0软件计算差异表达的NBS-encoding基因所在系统进化支的Ka/Ks值,研究NBS-encoding基因在进化过程中受到的选择压力;利用Cytoscape 3.0软件构建共表达网络图,分析NBS-encoding基因之间的关联性。[结果]共筛选得到了19个差异表达NBS-encoding基因。表达模式分析表明,有3个基因(登录号为MDP0000259862、MDP0000304378和MDP0000292810)可能在响应苹果斑点落叶病的过程中起了关键作用。19个差异表达基因分布在系统进化树的15个进化支中,其中进化支10、12、14、15的平均Ka/Ks值均大于1,说明这些进化支中的基因受到正选择压力的作用,尤其是登录号为MDP0000210357、MDP0000751628、MDP0000147704和MDP0000372663的基因;而其余15个NBS-encoding基因的平均Ka/Ks值均小于1,说明它们受到纯化选择的作用。此外,有16个基因处于同一个共表达网络中,登录号为MDP0000210357、MDP0000240537和MDP0000291205的基因扮演着重要的角色。[结论]19个苹果NBS-encoding基因参与苹果斑点落叶病菌侵染后的响应过程,其中登录号为MDP0000259862、MDP0000304378、MDP0000292810、MDP0000210357、MDP0000240537和MDP0000291205的基因可作为候选基因进行苹果抗病品种选育。 展开更多
关键词 苹果斑点落叶病 NBS-encoding基因 表达模式 选择压力 共表达网络
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Novel joint encoding/decoding algorithms of fountain codes for underwater acoustic communication 被引量:1
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作者 Mingshen Liang Jinjue Duan +2 位作者 Danfeng Zhao Jiaxi Si Xiangyu Song 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2016年第4期772-779,共8页
Fountain codes are considered to be a promising coding technique in underwater acoustic communication(UAC) which is challenged with the unique propagation features of the underwater acoustic channel and the harsh ma... Fountain codes are considered to be a promising coding technique in underwater acoustic communication(UAC) which is challenged with the unique propagation features of the underwater acoustic channel and the harsh marine environment. And Luby transform(LT) codes are the first codes fully realizing the digital fountain concept. However, in conventional LT encoding/decoding algorithms, due to the imperfect coverage(IC) of input symbols and short cycles in the generator matrix, stopping sets would occur and terminate the decoding. Thus, the recovery probability is reduced,high coding overhead is required and decoding delay is increased.These issues would be disadvantages while applying LT codes in underwater acoustic communication. Aimed at solving those issues, novel encoding/decoding algorithms are proposed. First,a doping and non-uniform selecting(DNS) encoding algorithm is proposed to solve the IC and the generation of short cycles problems. And this can reduce the probability of stopping sets occur during decoding. Second, a hybrid on the fly Gaussian elimination and belief propagation(OFG-BP) decoding algorithm is designed to reduce the decoding delay and efficiently utilize the information of stopping sets. Comparisons via Monte Carlo simulation confirm that the proposed schemes could achieve better overall decoding performances in comparison with conventional schemes. 展开更多
关键词 underwater acoustic communication(UAC) fountain codes non-uniform encoding hybrid decoding algorithm stopping sets
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Cloning and Characterization of a Tau Glutathione S-transferase Subunit Encoding Gene in Gossypium hirsutum 被引量:3
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作者 MA Zhi-ying,LI Zhi-kun,WANG Xing-fen,MA Jun,ZHANG Gui-yin(Agricultural University of Hebei,Baoding 071001,China) 《棉花学报》 CSCD 北大核心 2008年第S1期61-,共1页
A predicted tau glutathione S-transferase(GST) subunit encoding gene,named GhGST,was isolated from Gossypium hirsutum with RACE method from SSH library based on Verticillium
关键词 Cloning and Characterization of a Tau Glutathione S-transferase Subunit encoding Gene in Gossypium hirsutum
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In vivo gene therapy of murine melanoma mediated by recombinant vaccinia virus encoding human IL-2 gene
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作者 Bruce Acres 《中国实验血液学杂志》 CAS CSCD 1997年第3期317-318,共2页
Direct gene transfer into somatic tissue in vivo is adeveloping technology with potential application forcancer gene therapy. Retrovirus vector, which was aneffective vehicle, still has some disadvantages ingenerating... Direct gene transfer into somatic tissue in vivo is adeveloping technology with potential application forcancer gene therapy. Retrovirus vector, which was aneffective vehicle, still has some disadvantages ingenerating high titer recombinant vectors andmanipulating to mediate in viro gene transfer. In thispaper, recombinant vaccinia virus vector encoding 展开更多
关键词 MELANOMA encoding disadvantages SOMATIC MURINE TITER transfection HOMOLOGOUS expanded plaque
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The development and characterization ot recombinant adenovirus encoding RA538, p53 or p16 for gene therapy of cancer
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作者 Jinke Cheng, Chen Lin, Xueyan Zhang, Rong Xing, Juwei Mu, Min WuNational Laboratory of Molecular Oncology, Cancer Institute, Chinese Academy of Medical Sciences, and Peking Union Medical College, Beijing 100021 《中国实验血液学杂志》 CAS CSCD 1997年第3期331-332,共2页
We have constructed three recombinantadenoviruses encoding RA538, p53 or p16 respec-tively. These recombinant adenoviruses are able toexpress RA538, p53 or p16 in infected human cancercells. The transduction efficienc... We have constructed three recombinantadenoviruses encoding RA538, p53 or p16 respec-tively. These recombinant adenoviruses are able toexpress RA538, p53 or p16 in infected human cancercells. The transduction efficiency assay showed thatthe infected cancer cells inoculated with theserecombinant adenoviruses at MOI of 25 or greaterexhibited 100% transduction efficiency. The growthrates and colony formation of cancer cells infectedwith these recombinant adenoviruses were 展开更多
关键词 adenovirus encoding infected transduction CYTOMETRY inoculated colony SUBCUTANEOUS NUDE ARREST
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Improved encoding structure and decoding algorithms for spinal codes
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作者 HUANG Wensha WANG Lina 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2022年第4期856-866,共11页
To improve the error correction performance, an innovative encoding structure with tail-biting for spinal codes is designed. Furthermore, an adaptive forward stack decoding(A-FSD) algorithm with lower complexity for s... To improve the error correction performance, an innovative encoding structure with tail-biting for spinal codes is designed. Furthermore, an adaptive forward stack decoding(A-FSD) algorithm with lower complexity for spinal codes is proposed. In the A-FSD algorithm, a flexible threshold parameter is set by a variable channel state to narrow the scale of nodes accessed. On this basis, a new decoding method of AFSD with early termination(AFSD-ET) is further proposed. The AFSD-ET decoder not only has the ability of dynamically modifying the number of stored nodes, but also adopts the early termination criterion to curtail complexity. The complexity and related parameters are verified through a series of simulations. The simulation results show that the proposed spinal codes with tail-biting and the AFSD-ET decoding algorithms can reduce the complexity and improve the decoding rate without sacrificing correct decoding performance. 展开更多
关键词 spinal code tail-biting encoding lower decoding complexity early termination strategy
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Identification and Cloning of Resistance Gene Analogues (RGAs) Encoding NBS-LRR Proteins from Gossypium arboreum L.
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作者 AZHAR Muhammad Tehseen BASHIR Aftab BRIDDON Rob W MANSOOR Shahid 《棉花学报》 CSCD 北大核心 2008年第S1期42-,共1页
Plants have developed a complicated defense mechanism during evolution to resist the harmful pathogens they encountered.The mechanism involves the interaction of the plant resistance(R)
关键词 NBS encoding NBS-LRR Proteins from Gossypium arboreum L Identification and Cloning of Resistance Gene Analogues LRR RGAs
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An Improved Method of Linear Encoding Representation-A Cell Linear Quadtree
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作者 He Yu Zhang Qianren Ye Yizheng Li Zhongrong (Department of Computer science) 《哈尔滨工业大学学报》 EI CAS CSCD 北大核心 1990年第3期28-31,共4页
The linear encoding of a quadtree is an efficient way to represent the quadtree. In this paper, an improved linear quadtree, a cell linear quadtree, is proposed, in which its redundant storage is eliminated and the co... The linear encoding of a quadtree is an efficient way to represent the quadtree. In this paper, an improved linear quadtree, a cell linear quadtree, is proposed, in which its redundant storage is eliminated and the concept of a cell is introduced. Therefore, it has higher storage efficiency than a conventional linear quadtree. 展开更多
关键词 分支树 图像处理 图像编码 层状数据结构 编码表达法
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A position distribution measurement method and mathematical modeling of two projectiles simultaneous hitting target based on three photoelectric encoder detection screens
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作者 Hanshan Li Zixuan Cao Xiaoqian Zhang 《Defence Technology(防务技术)》 2025年第11期151-168,共18页
To solve the problem of identification and measurement of two projectiles hitting the target at the same time,this paper proposes a projectile coordinate test method combining three photoelectric encoder detection scr... To solve the problem of identification and measurement of two projectiles hitting the target at the same time,this paper proposes a projectile coordinate test method combining three photoelectric encoder detection screens,and establishes a coordinate calculation model for two projectiles to reach the same detection screen at the same time.The design method of three photoelectric encoder detection screens and the position coordinate recognition algorithm of the blocked array photoelectric detector when projectile passing through the photoelectric encoder detection screen are studied.Using the screen projection method,the intersected linear equation of the projectile and the line laser with the main detection screen as the core coordinate plane is established,and the projectile coordinate data set formed by any two photoelectric encoder detection screens is constructed.The principle of minimum error of coordinate data set is used to determine the coordinates of two projectiles hitting the target at the same time.The rationality and feasibility of the proposed test method are verified by experiments and comparative tests. 展开更多
关键词 Photoelectric encoder detection screen PROJECTILE Matching and recognition Linear laser Position distribution
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ENCODE计划和功能基因组研究 被引量:5
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作者 丁楠 渠鸿竹 方向东 《遗传》 CAS CSCD 北大核心 2014年第3期237-247,共11页
人类基因组计划完成以来,科学家们一直在努力阐释基因组信息所代表的生物学意义。自2003年开始,美国国家人类基因组研究所(National Human Genome Research Institute,NHGRI)投资近3亿美元启动"DNA元件百科全书(Encyclopedia of DN... 人类基因组计划完成以来,科学家们一直在努力阐释基因组信息所代表的生物学意义。自2003年开始,美国国家人类基因组研究所(National Human Genome Research Institute,NHGRI)投资近3亿美元启动"DNA元件百科全书(Encyclopedia of DNA Elements,ENCODE)"计划,集结了来自美国、中国、英国、日本、西班牙和新加坡等国家的32个实验室的440余名科学家,共同鉴定并分析人类基因组中所有的功能调控元件。高通量测序技术等实验手段的发展和生物信息学技术的不断完善使得ENCODE计划取得了丰硕的成果:确定了甲基化和组蛋白修饰等表观修饰区域及其对染色质结构的作用,进而确定染色质结构的改变影响基因表达;确定了转录因子及其结合位点的信息,并构建了转录因子调控网络;进一步修订更新了假基因和非编码RNA数据库;并确定了调控序列的单核苷酸多态性(Single nucleotide polymorphism,SNP)并与疾病相关联。这些发现一方面有助于系统解析基因和基因组信息、调控元件的调控作用以及非编码区转录调控等分子机制;同时也将为转化医学等生命科学研究领域提供丰富的数据来源。文章综述了高通量测序技术等实验手段的发展和生物信息学技术的不断完善对ENCODE计划的贡献、表观遗传学研究与ENCODE计划的关联性、ENCODE计划的主要科学成果等,同时展望了ENCODE计划对基础医学、临床医学和转化医学等生命科学研究领域的巨大推动作用。 展开更多
关键词 encodE 表观遗传学 新一代测序技术 转录调控
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一种融合AutoEncoder与CNN的混合算法用于图像特征提取 被引量:20
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作者 刘兴旺 王江晴 徐科 《计算机应用研究》 CSCD 北大核心 2017年第12期3839-3843,3847,共6页
深度学习方法在图像的特征提取方面具有优势。针对传统特征提取方法需要先验知识的不足,提出一种自动编码器(Auto Encoder)与卷积神经网络(convolutional neural network,CNN)相结合的深度学习特征提取方法。该方法给Auto Encoder加入... 深度学习方法在图像的特征提取方面具有优势。针对传统特征提取方法需要先验知识的不足,提出一种自动编码器(Auto Encoder)与卷积神经网络(convolutional neural network,CNN)相结合的深度学习特征提取方法。该方法给Auto Encoder加入快速稀疏性控制,据此对图像训练出基本构件,并初始化CNN的卷积核;同时,给CNN加入了滤波机制,使输出特征保持稀疏性。实验结果表明,在Minist手写数字库和Yale人脸库的识别效果上,提出的特征提取方法均取得了较好的结果,实验进一步通过交叉验证T检验指出,引入滤波机制的特征提取模型优于没有采用滤波机制的模型。 展开更多
关键词 深度学习 卷积神经网络 自动编码器 滤波 稀疏控制
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基于ENCODER_ATT机制的远程监督关系抽取
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作者 王健 郑七凡 +1 位作者 李超 石晶 《广西师范大学学报(自然科学版)》 CAS 北大核心 2019年第4期53-60,共8页
在信息抽取中,关系抽取是一项准确识别自然语言中实体间关系的关键技术。针对关系抽取模型中容易丢失关键语义特征问题及远程监督的基本假设容易引入噪声数据的问题,本文提出一种基于远程监督的ENCODER_ATT关系抽取模型。基于循环神经... 在信息抽取中,关系抽取是一项准确识别自然语言中实体间关系的关键技术。针对关系抽取模型中容易丢失关键语义特征问题及远程监督的基本假设容易引入噪声数据的问题,本文提出一种基于远程监督的ENCODER_ATT关系抽取模型。基于循环神经网络构造的ENCODER模型在以词级别进行特征记忆提取,并在句子层面进行语义特征信息整合,保证不遗失关键语义特征的同时去除冗余特征。然后在句子层面引入了注意力机制来降低噪声数据对实验结果的影响。在真实的数据集上进行实验,并绘制准确率-召回率曲线,实验结果表明ENCODER_ATT模型对比同类型的关系抽取方法有明显的提升。 展开更多
关键词 关系抽取 远程监督 encodER 注意力机制
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基于时空特征融合的Encoder-Decoder多步4D短期航迹预测 被引量:2
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作者 石庆研 张泽中 韩萍 《信号处理》 CSCD 北大核心 2023年第11期2037-2048,共12页
航迹预测在确保空中交通安全、高效运行中扮演着至关重要的角色。所预测的航迹信息是航迹优化、冲突告警等决策工具的输入,而预测准确性取决于模型对航迹序列特征的提取能力。航迹序列数据是具有丰富时空特征的多维时间序列,其中每个变... 航迹预测在确保空中交通安全、高效运行中扮演着至关重要的角色。所预测的航迹信息是航迹优化、冲突告警等决策工具的输入,而预测准确性取决于模型对航迹序列特征的提取能力。航迹序列数据是具有丰富时空特征的多维时间序列,其中每个变量都呈现出长短期的时间变化模式,并且这些变量之间还存在着相互依赖的空间信息。为了充分提取这种时空特征,本文提出了基于融合时空特征的编码器-解码器(Spatio-Temporal EncoderDecoder,STED)航迹预测模型。在Encoder中使用门控循环单元(Gated Recurrent Unit,GRU)、卷积神经网络(Convolutional Neural Network,CNN)和注意力机制(Attention,AT)构成的双通道网络来分别提取航迹时空特征,Decoder对时空特征进行拼接融合,并利用GRU对融合特征进行学习和递归输出,实现对未来多步航迹信息的预测。利用真实的航迹数据对算法性能进行验证,实验结果表明,所提STED网络模型能够在未来10 min预测范围内进行高精度的短期航迹预测,相比于LSTM、CNN-LSTM和AT-LSTM等数据驱动航迹预测模型具有更高的精度。此外,STED网络模型预测一个航迹点平均耗时为0.002 s,具有良好的实时性。 展开更多
关键词 4D航迹预测 时空特征 encoder-Decoder 门控循环单元
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基于encoder-decoder框架的城镇污水厂出水水质预测 被引量:4
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作者 史红伟 陈祺 +1 位作者 王云龙 李鹏程 《中国农村水利水电》 北大核心 2023年第11期93-99,共7页
由于污水厂的出水水质指标繁多、污水处理过程中反应复杂、时序非线性程度高,基于机理模型的预测方法无法取得理想效果。针对此问题,提出基于深度学习的污水厂出水水质预测方法,并以吉林省某污水厂监测水质为来源数据,利用多种结合encod... 由于污水厂的出水水质指标繁多、污水处理过程中反应复杂、时序非线性程度高,基于机理模型的预测方法无法取得理想效果。针对此问题,提出基于深度学习的污水厂出水水质预测方法,并以吉林省某污水厂监测水质为来源数据,利用多种结合encoder-decoder结构的神经网络预测水质。结果显示,所提结构对LSTM和GRU网络预测能力都有一定提升,对长期预测能力提升更加显著,ED-GRU模型效果最佳,短期预测中的4个出水水质指标均方根误差(RMSE)为0.7551、0.2197、0.0734、0.3146,拟合优度(R2)为0.9013、0.9332、0.9167、0.9532,可以预测出水质局部变化,而长期预测中的4个指标RMSE为1.7204、1.7689、0.4478、0.8316,R2为0.4849、0.5507、0.4502、0.7595,可以预测出水质变化趋势,与顺序结构相比,短期预测RMSE降低10%以上,R2增加2%以上,长期预测RMSE降低25%以上,R2增加15%以上。研究结果表明,基于encoder-decoder结构的神经网络可以对污水厂出水水质进行准确预测,为污水处理工艺改进提供技术支撑。 展开更多
关键词 污水厂出水 encoder-decoder 多指标水质预测 GRU模型
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基于Auto Encoder的智能监控指纹识别系统
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作者 常峰 贺元骅 《中国测试》 CAS 北大核心 2015年第8期71-74,93,共5页
针对目前已有的嵌入式指纹识别系统往往采用手工提取,不能自动学习并提取识别所需的特征及识别正确率仍然不高的缺点,提出一种基于自动编码器(Auto Encoder)和LSSVM的指纹识别系统。首先,提出采用FPS200作为指纹传感器采集指纹数据,然... 针对目前已有的嵌入式指纹识别系统往往采用手工提取,不能自动学习并提取识别所需的特征及识别正确率仍然不高的缺点,提出一种基于自动编码器(Auto Encoder)和LSSVM的指纹识别系统。首先,提出采用FPS200作为指纹传感器采集指纹数据,然后将采集的数据经过滤波和二值化等预处理,通过比较差异算法获得Auto Encoder中的权值和偏置等参数,从而得到训练好的Auto Encoder用于指纹图像特征提取。最后,将自动提取的特征进行训练和分类,将投票最多的分类作为指纹识别的结果。通过测试表明,系统能较精确地实现指纹识别,具有收敛速度快、正确识别率高和匹配时间短的优点。 展开更多
关键词 指纹 识别率 匹配 自动编码器
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基于Encoder-CNN的土壤氮含量光谱预测模型研究 被引量:5
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作者 冀荣华 赵迎迎 +1 位作者 李民赞 郑立华 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2022年第5期1372-1377,共6页
基于光谱的土壤氮含量预测模型泛化能力弱是制约其推广应用的瓶颈。鉴于特征提取及非线性表达能力方面的优势,深度学习模型具有较强的泛化能力。提出一种融合自动编码器和卷积神经网络(Encoder-CNN)的土壤氮含量光谱预测模型,探索模型... 基于光谱的土壤氮含量预测模型泛化能力弱是制约其推广应用的瓶颈。鉴于特征提取及非线性表达能力方面的优势,深度学习模型具有较强的泛化能力。提出一种融合自动编码器和卷积神经网络(Encoder-CNN)的土壤氮含量光谱预测模型,探索模型结构和参数对模型性能的影响。根据以往研究成果和相关性分析,获得180个与氮含量强相关的波长,将其作为Encoder-CNN模型输入,而将土壤氮含量作为模型输出。Encoder-CNN模型利用自动编码器的编码部分进行光谱数据降维,然后输入到卷积神经网络进行土壤氮含量预测。设计2种网络结构,每种网络结构包含2种不同参数设置,共4个模型,用以探索Encoder-CNN土壤氮含量光谱预测模型结构和参数对模型性能的影响。利用公开数据集LUCAS对模型进行训练。按3σ原则对公开数据集LUCAS进行异常值检测与处理,获得20791个数据,其中18711个样本作为训练集,2080个样本作为测试集,对Encoder-CNN模型进行训练。结果表明:对于自动编码器,在相同隐含层数下,最后的隐含层神经元个数为30时,复现效果最优。增加隐含层数,会提升复现效果。增加卷积核数量,特别是尺寸为1×1卷积核,能够提高模型的预测性能与可靠性。增加池化层的网络结构,模型预测精度提升至0.90以上。增加全连接层神经元数量也会提升模型性能。利用自采集的黑龙江黑土实时光谱数据集进行模型迁移,观察模型泛化能力。当模型迭代100次后,在黑龙江数据集上的预测精度即可达到0.90以上;当迭代次数为900时,模型在训练集和测试集上的预测精度可以达到0.98。结果表明,所构建的Encoder-CNN土壤氮含量光谱预测模型具有较好的泛化能力。 展开更多
关键词 土壤 氮含量 光谱预测 卷积神经网络 自动编码器
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