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一种基于时域融合Transformer的4D航迹预测方法
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作者 孔建国 马珂昕 +2 位作者 梁海军 张向伟 常瀚文 《电讯技术》 北大核心 2026年第1期21-29,共9页
针对传统4D航迹预测方法在数据单一和特征选择上的局限,提出了一种基于时域融合Transformer(Temporal Fusion Transformer,TFT)模型的4D航迹预测方法。引入下降率、时序分量等多元特征,并将数据按是否随时间变化及数值属性进行分类,以... 针对传统4D航迹预测方法在数据单一和特征选择上的局限,提出了一种基于时域融合Transformer(Temporal Fusion Transformer,TFT)模型的4D航迹预测方法。引入下降率、时序分量等多元特征,并将数据按是否随时间变化及数值属性进行分类,以体现飞行过程中不同阶段的差异;采用TFT模型有效捕捉各特征之间的隐式相关性,从而提高了预测精度;同时,结合分位数回归实现不确定性量化,提供了具有置信区间的航迹预测结果。实验表明,所提方法在真实数据上优于传统模型:与CNNLSTM模型和LSTM模型相比,平均距离误差分别减少了22.7%和50.9%,纵向、横向和垂直误差分别为305.01 m、177.91 m和25.23 m,验证了模型在解决航迹预测问题上的有效性,能够为管制精细化调控提供有效支持。 展开更多
关键词 空中交通管制 4d航迹预测 自动相关监视系统数据 时域融合transformer 时间序列预测
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DEVELOPMENT OF COMPUTER SIMULATION SOFTWAREON PHASE TRANSFORMATION DURING QUENCHING 被引量:5
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作者 L. Chen, W. Xia and X. J. Chen Department of Materials Science and Engineering, Nanchang Institute of Aeronautical Technology, Nanchang 330034, China 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2000年第2期618-622,共5页
A computer software to simulate the phase transformation during quenching is designed based on Avrami equation and Scheil additivity principle of incubation period. The isothermal transformation diagrams of supercool... A computer software to simulate the phase transformation during quenching is designed based on Avrami equation and Scheil additivity principle of incubation period. The isothermal transformation diagrams of supercooled austenite are described by cubic spline functions. This software is possess of a good graphic interface of Windows style, can simulate the whole process in austenite decomposition during continuous cooling. If the cooling rate was given, the fraction of various microstructures transformed of austenite decomposition during continuous cooling at any temperature can be calculated. The simulation results are checked with the quenching experiment of 45 steel. The results indicate that the simulation results are comparatively close to the experimental results. 展开更多
关键词 QUENCHING phase transformation computer simulation software
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How Software Engineering Transforms Organizations: An Open and Qualitative Study on the Organizational Objectives and Motivations in Agile Transformations
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作者 Alonso Alvarez Borja Bordel Sánchez 《Computers, Materials & Continua》 SCIE EI 2024年第11期2935-2966,共32页
Agile Transformations are challenging processes for organizations that look to extend the benefits of Agile philosophy and methods beyond software engineering.Despite the impact of these transformations on orga-nizati... Agile Transformations are challenging processes for organizations that look to extend the benefits of Agile philosophy and methods beyond software engineering.Despite the impact of these transformations on orga-nizations,they have not been extensively studied in academia.We conducted a study grounded in workshops and interviews with 99 participants from 30 organizations,including organizations undergoing transformations(“final organizations”)and companies supporting these processes(“consultants”).The study aims to understand the motivations,objectives,and factors driving and challenging these transformations.Over 700 responses were collected to the question and categorized into 32 objectives.The findings show that organizations primarily aim to achieve customer centricity and adaptability,both with 8%of the mentions.Other primary important objectives,with above 4%of mentions,include alignment of goals,lean delivery,sustainable processes,and a flatter,more team-based organizational structure.We also detect discrepancies in perspectives between the objectives identified by the two kinds of organizations and the existing agile literature and models.This misalignment highlights the need for practitioners to understand with the practical realities the organizations face. 展开更多
关键词 Business agility AGILE agile transformations agile enterprises adaptive organizations AdAPTABILITY agile software development software engineering computer engineering
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Towards automated software model checking using graph transformation systems and Bogor
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作者 Vahid RAFE Adel T.RAHMANI 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2009年第8期1093-1105,共13页
Graph transformation systems have become a general formal modeling language to describe many models in software development process.Behavioral modeling of dynamic systems and model-to-model transformations are only a ... Graph transformation systems have become a general formal modeling language to describe many models in software development process.Behavioral modeling of dynamic systems and model-to-model transformations are only a few examples in which graphs have been used to software development.But even the perfect graph transformation system must be equipped with automated analysis capabilities to let users understand whether such a formal specification fulfills their requirements.In this paper,we present a new solution to verify graph transformation systems using the Bogor model checker.The attributed graph grammars(AGG)-like graph transformation systems are translated to Bandera intermediate representation(BIR),the input language of Bogor,and Bogor verifies the model against some interesting properties defined by combining linear temporal logic(LTL) and special-purpose graph rules.Experimental results are encouraging,showing that in most cases our solution improves existing approaches in terms of both performance and expressiveness. 展开更多
关键词 Graph transformation VERIFICATION Bogor Attributed graph grammars (AGG) software model checking
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A Neuro-Based Software Fault Prediction with Box-Cox Power Transformation
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作者 Momotaz Begum Tadashi Dohi 《Journal of Software Engineering and Applications》 2017年第3期288-309,共22页
Software fault prediction is one of the most fundamental but significant management techniques in software dependability assessment. In this paper we concern the software fault prediction using a multilayer-perceptron... Software fault prediction is one of the most fundamental but significant management techniques in software dependability assessment. In this paper we concern the software fault prediction using a multilayer-perceptron neural network, where the underlying software fault count data are transformed to the Gaussian data, by means of the well-known Box-Cox power transformation. More specially, we investigate the long-term behavior of software fault counts by the neural network, and perform the multi-stage look ahead prediction of the cumulative number of software faults detected in the future software testing. In numerical examples with two actual software fault data sets, we compare our neural network approach with the existing software reliability growth models based on nonhomogeneous Poisson process, in terms of predictive performance with average relative error, and show that the data transformation employed in this paper leads to an improvement in prediction accuracy. 展开更多
关键词 software Reliability Artificial Neural Network Box-Cox Power transformation LONG-TERM PREdICTION FAULT COUNT data Empirical Validation
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SESDP:A Sentiment Analysis-Driven Approach for Enhancing Software Product Security by Identifying Defects through Social Media Reviews
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作者 Farah Mohammad Saad Al-Ahmadi Jalal Al-Muhtadi 《Computers, Materials & Continua》 2025年第4期1327-1345,共19页
Software defect prediction is a critical component in maintaining software quality,enabling early identification and resolution of issues that could lead to system failures and significant financial losses.With the in... Software defect prediction is a critical component in maintaining software quality,enabling early identification and resolution of issues that could lead to system failures and significant financial losses.With the increasing reliance on user-generated content,social media reviews have emerged as a valuable source of real-time feedback,offering insights into potential software defects that traditional testing methods may overlook.However,existing models face challenges like handling imbalanced data,high computational complexity,and insufficient inte-gration of contextual information from these reviews.To overcome these limitations,this paper introduces the SESDP(Sentiment Analysis-Based Early Software Defect Prediction)model.SESDP employs a Transformer-Based Multi-Task Learning approach using Robustly Optimized Bidirectional Encoder Representations from Transformers Approach(RoBERTa)to simultaneously perform sentiment analysis and defect prediction.By integrating text embedding extraction,sentiment score computation,and feature fusion,the model effectively captures both the contextual nuances and sentiment expressed in user reviews.Experimental results show that SESDP achieves superior performance with an accuracy of 96.37%,precision of 94.7%,and recall of 95.4%,particularly excelling in handling imbalanced datasets compared to baseline models.This approach offers a scalable and efficient solution for early software defect detection,enhancing proactive software quality assurance. 展开更多
关键词 software defect data balancing feature extraction RoBERTa transformer
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基于3D-CNN和融合Transformer的步态识别算法 被引量:1
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作者 李金成 代雪晶 闫睿骜 《科学技术与工程》 北大核心 2025年第17期7276-7284,共9页
当前,步态识别的主流方法常依赖堆叠卷积层来逐步扩大感受野,以融合局部特征,这种方法大多采用浅层网络,在提取步态图像的全局特征时存在一定的局限性,并缺乏对时序周期特征信息的关注。因此提出一种融合Transformer和3D卷积的深层神经... 当前,步态识别的主流方法常依赖堆叠卷积层来逐步扩大感受野,以融合局部特征,这种方法大多采用浅层网络,在提取步态图像的全局特征时存在一定的局限性,并缺乏对时序周期特征信息的关注。因此提出一种融合Transformer和3D卷积的深层神经网络算法(3D convolutional gait recognition network based on adaptFormer and spect-conv,3D-ASgaitNet)。首先,初始残差卷积层将二进制轮廓数据转换为浮点编码特征图,以提供密集的低级结构特征;在此基础上,光谱层通过频域和时域的联合处理增强特征提取能力,并使用伪3D残差卷积模块进一步提取高级时空特征;最后融合AdaptFormer模块,通过轻量级的下采样-上采样网络结构,以适应不同的数据分布和任务需求,提供灵活的特征变换能力。3D-ASgaitNet分别在4个公开的室内数据集(CASIA-B、OU-MVLP)、室外数据集(GREW、Gait3D)上进行,分别取得99.84%、87.83%、45.32%、72.12%的识别准确率。实验结果表明,所提出方法在CASIA-B、Gait3D数据集中的识别准确率接近SOTA性能。 展开更多
关键词 步态识别 融合transformer 3d残差卷积 二进制轮廓数据
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血清TGF-β1、CRP和维生素D水平与子宫肌瘤患者术后转归的相关性
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作者 卫伟 王一娜 +1 位作者 唐梅兰 蒋嫒 《西部医学》 2026年第3期451-454,459,共5页
目的 探讨血清转化生长因子-β1(TGF-β1)、C反应蛋白(CRP)和维生素D(VD)水平与子宫肌瘤患者术后转归的相关性。方法 选取2019年3月—2023年3月于本院行子宫肌瘤剔除术的患者254例为研究对象,并根据是否复发分为非复发组(n=171)和复发组... 目的 探讨血清转化生长因子-β1(TGF-β1)、C反应蛋白(CRP)和维生素D(VD)水平与子宫肌瘤患者术后转归的相关性。方法 选取2019年3月—2023年3月于本院行子宫肌瘤剔除术的患者254例为研究对象,并根据是否复发分为非复发组(n=171)和复发组(n=83)。收集患者临床资料、血清TGF-β1、CRP和VD水平检测数据进行单因素分析;Spearman相关性分析相关因素与术后复发的相关性;多因素二元Logistic回归分析术后复发的独立影响因素。结果 行子宫剔除术的患者术后复发病理类型为弥漫型、肌瘤位置位于肌壁间以及数目≥4个的占比、TGF-β1、CRP水平更高,而VD水平更低(P<0.05);术后复发与病理类型、肌瘤位置以及数目的占比、TGF-β1、CRP水平呈显著正相关,而与VD水平呈显著负相关(P<0.05),TGF-β1水平具有最强相关性(r=0.741,P<0.001);肌瘤数目、TGF-β1、CRP以及VD水平均为子宫肌瘤患者术后复发的独立影响因素。结论 肌瘤数目≥4个、较高水平的TGF-β1和CRP、较低水平的VD能够增加患者术后复发风险,该结果能够为临床实践的早期预防、干预以及治疗方案提供参考。 展开更多
关键词 子宫肌瘤 转化生长因子-Β1 C反应蛋白 维生素d 复发 相关性
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基于Transformer模型的3D NAND闪存剩余寿命预测方法
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作者 石颖 杨少华 +2 位作者 周斌 吴福根 胡湘洪 《微电子学》 北大核心 2025年第2期327-334,共8页
为了预测3D NAND闪存的剩余使用寿命以及提高数据存储的可靠性,设计了3D NAND闪存的高温和温度循环实验,分析了各项操作时间和原始错误比特数的变化趋势。同时建立了一种改进的Transformer模型,以预处理后的寿命特征数据为输入,对3D NAN... 为了预测3D NAND闪存的剩余使用寿命以及提高数据存储的可靠性,设计了3D NAND闪存的高温和温度循环实验,分析了各项操作时间和原始错误比特数的变化趋势。同时建立了一种改进的Transformer模型,以预处理后的寿命特征数据为输入,对3D NAND闪存的剩余使用寿命进行预测。与LSTM、GRU相比,所建立模型在高温擦写实验数据集中的均方根误差分别下降了20.5%、21.0%;在温度循环擦写实验数据集中则分别下降2.5%和7.8%。实验结果表明,该模型可以准确预测3D NAND闪存的剩余寿命,优化闪存寿命管理策略。 展开更多
关键词 3d NANd闪存 剩余使用寿命 transformer模型 寿命预测
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Uses of a dedicated 3D reconstruction software with augmented and mixed reality in planning and performing advanced liver surgery and living donor liver transplantation(with videos) 被引量:8
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作者 Deniz Balci Elvan Onur Kirimker +2 位作者 Dimitri Aristotle Raptis Yujia Gao Alfred Wei Chieh Kow 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS CSCD 2022年第5期455-461,共7页
The development of digital intelligent diagnostic and treatment technology has opened countless new opportunities for liver surgery from the era of digital anatomy to a new era of digital diagnostics,virtual surgery s... The development of digital intelligent diagnostic and treatment technology has opened countless new opportunities for liver surgery from the era of digital anatomy to a new era of digital diagnostics,virtual surgery simulation and using the created scenarios in real-time surgery using mixed reality.In this article,we described our experience on developing a dedicated 3 dimensional visualization and reconstruction software for surgeons to be used in advanced liver surgery and living donor liver transplantation.Furthermore,we shared the recent developments in the field by explaining the outreach of the software from virtual reality to augmented reality and mixed reality. 展开更多
关键词 Living donor liver transplantation 3d reconstruction software 3d volumetry Precision medicine Augmented reality Mixed reality
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Design and implementation of five-axis transformation function in CNC system 被引量:6
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作者 Wang Feng Lin Hu +3 位作者 Zheng Liaomo Yang Lei Feng Jinjin Zhang Han 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2014年第2期425-437,共13页
To implement five-axis functions in CNC system, based on domestic system Lan Tian series, an improved design method for the system software structure is proposed in this paper. The numerical control kernel of CNC syst... To implement five-axis functions in CNC system, based on domestic system Lan Tian series, an improved design method for the system software structure is proposed in this paper. The numerical control kernel of CNC system is divided into the task layer and the motion layer. A five-axis transformation unit is integrated into the motion layer. After classifying five-axis machines into different types and analyzing their geometry information, the five-axis kinematic library is designed according to the abstract factory pattern. Furthermore, by taking CA spindle- tilting machine as an example, the forward and the inverse kinematic transformations are deduced. Based on the new software architecture and the five-axis kinematic library, algorithms of RTCP (rotation tool center point control) and 3D radius compensation for end-milling are designed and realized. The milling results show that, with five-axis functions based on such software struc- ture, the instructions with respect to the cutter's position and orientation can be directly carried out in the CNC system. 展开更多
关键词 3d cutter radiuscompensation CNC software structure Five-axis transformationfunction Motion control Rotation tool center pointcontrol
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Applications of Lodrigues Matrix in 3D Coordinate Transformation 被引量:3
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作者 YAO Jili XU Yufei XIAO Wei 《Geo-Spatial Information Science》 2007年第3期173-176,共4页
Three transformation models (Bursa-Wolf, Molodensky, and WTUSM) are generally used between two data systems transformation. The linear models are used when the rotation angles are small; however, when the rotation a... Three transformation models (Bursa-Wolf, Molodensky, and WTUSM) are generally used between two data systems transformation. The linear models are used when the rotation angles are small; however, when the rotation angles get bigger, model errors will be produced. In this paper, we present a method with three main terms:① the traditional rotation angles θ,φ,ψ are substituted with a,b,c which are three respective values in the anti-symmetrical or Lodrigues matrix; ② directly and accurately calculating the formula of seven parameters in any value of rotation angles; and ③ a corresponding adjustment model is established. This method does not use the triangle function. Instead it uses addition, subtraction, multiplication and division, and the complexity of the equation is reduced, making the calculation easy and quick. 展开更多
关键词 3d transformation linear model transformation equation Lodrigues matrix
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基于Transformer全局-局部特征融合的RGB-D显著性检测 被引量:2
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作者 宋梦柯 王芸 郑元超 《计算机应用与软件》 北大核心 2025年第3期176-182,共7页
现有的RGB-D方法一般通过局部操作分别应用多尺度和多模态融合,但这无法捕获远程依赖性,因此对特征整体表征能力不足。针对此问题,提出一种全局-局部特征融合网络。在低层特征提取阶段,将两个分支特征直接融合;在高层特征提取阶段,将融... 现有的RGB-D方法一般通过局部操作分别应用多尺度和多模态融合,但这无法捕获远程依赖性,因此对特征整体表征能力不足。针对此问题,提出一种全局-局部特征融合网络。在低层特征提取阶段,将两个分支特征直接融合;在高层特征提取阶段,将融合后特征送入Transformer编码器通过在所有位置同时整合多尺度和多模态的特征来进行充分的特征融合,获得全局特征依赖关系之后再送入主干网络提取全局—局部融合特征。同时提出双重注意力模块,用来增强两个分支特征的融合效果。在五个公开数据集上进行的实验表明,该网络在三个评价指标上均取得了较好的表现。 展开更多
关键词 RGB-d显著性检测 全局-局部特征 跨模态融合 多尺度 transformER
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A three-dimensional transient electromagnetic data inversion method based on a time–frequency transformation 被引量:3
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作者 Yang Yun-Jian Wang Xu-Ben +2 位作者 Liu Xue-Jun Mi Xiao-Li Mao Lifeng 《Applied Geophysics》 SCIE CSCD 2020年第3期361-376,共16页
Herein,a three-dimensional(3D)inversion method in the frequency domain based on a time–frequency transformation was developed to improve the efficiency of the 3D inversion of transient electromagnetic(TEM)data.The Fo... Herein,a three-dimensional(3D)inversion method in the frequency domain based on a time–frequency transformation was developed to improve the efficiency of the 3D inversion of transient electromagnetic(TEM)data.The Fourier transform related to the electromagnetic response in the frequency and time domains becomes a sine or cosine transform under the excitation of downward-step current.We established a transformation matrix based on the digital fi ltering calculation for the sine transform,and then the frequency domain projection of the TEM data was determined from the linear transformation system using the smoothing constrained least squares inversion method,in which only the imaginary part was used to maintain the TEM data transformation equivalence in the bidirectional projection.Thus,the time-domain TEM inversion problem was indirectly and effectively solved in the frequency domain.In the 3D inversion of the transformed frequency-domain data,the limited-memory Broyden–Fletcher–Goldfarb–Shannoquasi–Newton(L-BFGS)method was used and modifi ed with a restart strategy to adjust the regularization parameter when the algorithm tended to a local minimum.Synthetic data tests showed that our domain transformation method can stably project the TEM data into the frequency domain with very high accuracy;furthe rmore,the 3D inversion of the transformed frequency-domain data is stable,can be used to recover the real resistivity model with an acceptable effi ciency. 展开更多
关键词 Transient electromagnetic method TEM digital filtering time-frequency transformation 3d EM forward 3d EM inversion
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A complete solution of an improved universal 3D coordinate similarity transformation model 被引量:3
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作者 Leyang Wang Jianqiang Sun Qiwen Wu 《Geodesy and Geodynamics》 CSCD 2021年第2期125-132,共8页
When linearizing three-dimensional(3 D)coordinate similarity transformation model with large rotations,we usually encounter the ill-posed normal matrix which may aggravate the instability of solutions.To alleviate the... When linearizing three-dimensional(3 D)coordinate similarity transformation model with large rotations,we usually encounter the ill-posed normal matrix which may aggravate the instability of solutions.To alleviate the problem,a series of conversions are contributed to the 3 D coordinate similarity transformation model in this paper.We deduced a complete solution for the 3 D coordinate similarity transformation at any rotation with the nonlinear adjustment methodology,which involves the errors of the common and the non-common points.Furthermore,as the large condition number of the normal matrix resulted in an intractable form,we introduced the bary-centralization technique and a surrogate process for deterministic element of the normal matrix,and proved its benefit for alleviating the condition number.The experimental results show that our approach can obtain the smaller condition number to stabilize the convergence of the interested parameters.Especially,our approach can be implemented for considering the errors of the common and the non-common points,thus the accuracy of the transformed coordinates improves. 展开更多
关键词 3d coordinate transformation Nonlinear adjustment Complete solution Condition number Bary-centralization
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An iterative algorithm of NWTLS-EC for three dimensional-datum transformation with large rotation angle 被引量:2
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作者 Hu Chuan Chen Yi 《Geodesy and Geodynamics》 2014年第4期38-48,共11页
The Gauss-Markov (GM) model and the Errors-in-Variables (EIV) model are frequently used to perform 3D coordinate transformations in geodesy and engineering surveys. In these applications, because the observation e... The Gauss-Markov (GM) model and the Errors-in-Variables (EIV) model are frequently used to perform 3D coordinate transformations in geodesy and engineering surveys. In these applications, because the observation errors in original coordinates system are also taken into account, the latter is more accurate and reasonable than the former. Although the Weighted Total Least Squares (WTLS) technique has been intro- duced into coordinate transformations as the measured points are heteroscedastic and correlated, the Variance- Covariance Matrix (VCM) of observations is restricted by a particular structure, namely, only the correlations of each points are taken into account. Because the 3D datum transformation with large rotation angle is a non- linear problem, the WTLS is no longer suitable in this ease. In this contribution, we suggested the nonlinear WTLS adjustments with equality constraints (NWTLS-EC) for 3D datum transformation with large rotation an- gle, which removed the particular structure restriction on the VCM. The Least Squares adjustment with Equality (LSE) constraints is employed to solve NWTLS-EC as the nonlinear model has been linearized, and an iterative algorithm is proposed with the LSE solution. A simulation study of 3D datum transformation with large rotation angle is given to insight into the feasibility of our algorithm at last. 展开更多
关键词 nonlinear weighted total least squares equality constraints 3d datum transformation heterosce-dastic and correlated orthogonal transformation
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融合Vision Transformer与3D CNN的深度伪造视频篡改检测
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作者 孙立信 吴永飞 +2 位作者 李心宇 任杰煌 刘西林 《计算机应用与软件》 北大核心 2025年第11期121-127,共7页
Deepfake技术的出现,使人们可以轻松地对人脸视频进行篡改,对社会造成巨大的危害。现有的篡改检测方法主要侧重于视频帧间的局部人脸区域空间特征变化检测,并没有考虑连续全局区域的时域特征,且不能检测视频帧中的细微空域特征变化。针... Deepfake技术的出现,使人们可以轻松地对人脸视频进行篡改,对社会造成巨大的危害。现有的篡改检测方法主要侧重于视频帧间的局部人脸区域空间特征变化检测,并没有考虑连续全局区域的时域特征,且不能检测视频帧中的细微空域特征变化。针对此问题,提出融合Vision Transformer和3D CNN的视频篡改检测方法ViT-3DCNN。该方法无需对人脸进行裁剪,直接学习视频帧间的连续时域特征以及每一帧的空间特征。实验结果表明,不依赖于人脸剪裁的情况下,ViT-3DCNN模型分别在DFDC数据集及Celeb-DF数据集上取得了93.3%与90.65%的分类准确性,充分验证了该模型在检测精度和泛化性等方面相较于现有检测方法具有明显的优势。 展开更多
关键词 伪造视频篡改检测 时空特征 Vision transformer 3d卷积
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基于时空感知Transformer的进近管制区4D航迹预测模型
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作者 霍丹 夏付豪 《空军工程大学学报》 北大核心 2025年第6期1-11,共11页
为保证进近管制区空中交通服务质量与飞行安全,提出一种基于时空感知Transformer模型的4D航迹预测方法,将轨迹预测转换成时间序列预测问题,通过挖掘航迹历史飞行数据的时空特征作为模型输入,综合考虑起飞机场、航空器类型、尾流类型、... 为保证进近管制区空中交通服务质量与飞行安全,提出一种基于时空感知Transformer模型的4D航迹预测方法,将轨迹预测转换成时间序列预测问题,通过挖掘航迹历史飞行数据的时空特征作为模型输入,综合考虑起飞机场、航空器类型、尾流类型、落地跑道、航空器位姿等关键维度,采用门控循环单元(GRU)提取航迹数据中时间依赖性,并结合时间卷积-门控循环单元网络(TCN-GRU)提取航迹数据的空间特征,从而构建4D航迹时序预测模型,实现高精度的多步航迹预测。实验表明,提出的预测模型相较于传统Transformer模型,随着步长的递增,预测精度的均方根误差减少了20.1%,平均绝对误差减少了27.82%,该研究成果对于提升空中交通的效率和安全性具有重要意义。 展开更多
关键词 空中交通管理 4d航迹预测 时空特征提取 transformer模型 深度学习
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Improvement in salt tolerance of Populus tomentosa from transformation by a mtl-D gene 被引量:4
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作者 Li Min Wang Hua-fang +2 位作者 Yin Wei-lun He Si-jie Chen Shou-yi 《Forestry Studies in China》 CAS 2006年第4期20-24,共5页
Transgenic lines were achieved by transforming the E. coli 1-phosphate mannitol dehydrogenase gene (mtl-D) into the Populus tomentosa Cart. genome. An Agrobacterium tumefaciens strain (AGL1), constructed by clonin... Transgenic lines were achieved by transforming the E. coli 1-phosphate mannitol dehydrogenase gene (mtl-D) into the Populus tomentosa Cart. genome. An Agrobacterium tumefaciens strain (AGL1), constructed by cloning mtl-D into the disarmed plasmid pBin438, was used to infect leaves of the clone YW2. The infected leaf discs were cultured on a medium containing 30 mg.L 1 kanamycin and 500 mg.L 1 cefotaxime. Transgenic plantlets regenerated from the infected leaves, rooted on the medium con- taining 30 mg.L 1 kanamycin. PCR and a Southern blotting test verified that the exogenous mtl-D gene had integrated into the trans- formation plants of the P. tomentosa genome. The mannitol content in control plant was 69 gg.gl FW, and the mannitol contents of the transgenic lines T1 to T5 ranged between 103.7 and 289.5 μg·g^-1 FW. Of the shoots of the control plants 20% survived; on the medium containing 0.6% NaCl, 60% and 70% of two transgenic shoots survived on a medium containing 0.8% NaCI. 展开更多
关键词 Populus tomentosa Carr mtl-d transformation salt tolerance
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基于“序列-结构-机理”的计算机辅助DAEase新序列挖掘
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作者 丁文涛 黄驰 +3 位作者 刘臣飒 李若涵 王昌禄 郭庆彬 《天津科技大学学报》 2026年第1期1-10,共10页
为丰富D-阿洛酮糖-3-差向异构酶(D-allulose 3-epimerase,DAEase)家族成员,采用序列比对、同源建模、分子对接、蛋白表达、酶活检测等方法,建立基于“序列-结构-机理”的计算机辅助DAEase挖掘新策略,成功筛选到DAEase新序列并对其进行... 为丰富D-阿洛酮糖-3-差向异构酶(D-allulose 3-epimerase,DAEase)家族成员,采用序列比对、同源建模、分子对接、蛋白表达、酶活检测等方法,建立基于“序列-结构-机理”的计算机辅助DAEase挖掘新策略,成功筛选到DAEase新序列并对其进行表征。利用模板探针从NCBI数据库中筛选同源序列,根据对接质量、关键氨基酸数量、底物氢键个数及催化机理对候选序列进行综合评分;合成不同分值的DAEase候选序列进行表达验证,发现2个高分候选序列具备明显DAEase催化活性,而3个低分候选序列催化活性极低,与预测相吻合。对活性较高的来源于厚壁细菌(Firmicutes bacterium)HGW的DAEase(Fbh-DAEase)进行表征,结果显示:Fbh-DAEase为非金属离子依赖酶,其最适反应pH为6.5;最适温度为55℃,45、50、55℃的半衰期分别为3.9、2.3、1.7 h;最适反应条件下Fbh-DAEase的比活力达到254.3 U/mg。以500 g/L D-果糖为底物时,Fbh-DAEase催化反应8 h后D-阿洛酮糖产量达到137.8 g/L,转化率为27.56%。与现有DAEase相比,Fbh-DAEase的比活力和热稳定性都达到较高水平,且最适pH为弱酸性,具有一定的应用价值。 展开更多
关键词 d-阿洛酮糖-3-差向异构酶 新酶挖掘 d-阿洛酮糖 生物转化 合成生物学
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