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法向量位置模型下旋转调制惯导极区综合校正算法 被引量:1
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作者 刘潺 吴文启 +1 位作者 冯国虎 王茂松 《中国惯性技术学报》 EI CSCD 北大核心 2023年第2期107-113,共7页
为抑制极区惯性导航系统随时间积累的导航误差,提出一种基于法向量位置模型的综合校正算法,对旋转调制惯导系统的等效方位陀螺常值漂移进行了估计。在法向量位置模型下建立了位置误差与漂移角之间的数学模型,推导了漂移角和等效方位陀... 为抑制极区惯性导航系统随时间积累的导航误差,提出一种基于法向量位置模型的综合校正算法,对旋转调制惯导系统的等效方位陀螺常值漂移进行了估计。在法向量位置模型下建立了位置误差与漂移角之间的数学模型,推导了漂移角和等效方位陀螺常值漂移的方程,在外水平阻尼条件下设计实现了综合校正算法。基于北极实际航测数据的处理试验结果表明,提出的综合校正算法具有全球适用性,能够估计等效方位陀螺常值漂移以提高导航定位精度,采用所提综合校正算法后的归一化定位误差相比于阻尼后的结果大约减小53%。 展开更多
关键词 法向量模型 极区惯性导航 全球适用性 综合校正
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有向地理信息要素方向的自动推演方法研究
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作者 曹贇昀 王慧 +2 位作者 吴承红 江宁 盛利杰 《测绘与空间地理信息》 2024年第1期39-41,共3页
为自动化解决地理空间数据库中有向要素空间冲突检测和推演问题,在空间关系理论和有向线模型的指导下,提出一种基于法向量模型的有向线方向推演算法,能够自动化实现有向要素方向的推演,为提升地理信息数据实际生产中的效率和质量提供了... 为自动化解决地理空间数据库中有向要素空间冲突检测和推演问题,在空间关系理论和有向线模型的指导下,提出一种基于法向量模型的有向线方向推演算法,能够自动化实现有向要素方向的推演,为提升地理信息数据实际生产中的效率和质量提供了解决方案。 展开更多
关键词 有向要素 法向量模型 方向自动推演
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向量空间模型法用于网上卫生装备信息资源自动搜集技术研究
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作者 孟海滨 《医疗卫生装备》 CAS 2002年第5期11-13,共3页
目的:实现网上卫生装备信息资源自动搜集。方法:采用向量空间模型法标识网页的类别特征,并研究用于网上卫生装备信息搜集的特征向量及识别阈值参数计算实现方法。结果:初步试验表明,通过合理确定各项参数使该系统运行达到了较好的效果,... 目的:实现网上卫生装备信息资源自动搜集。方法:采用向量空间模型法标识网页的类别特征,并研究用于网上卫生装备信息搜集的特征向量及识别阈值参数计算实现方法。结果:初步试验表明,通过合理确定各项参数使该系统运行达到了较好的效果,能够获取典型的卫生装备网页信息。结论:向量空间模型法适合于网上卫生装备信息的识别,在系统收集效率和精度上及分类收集方面仍需对算法进行优化。 展开更多
关键词 向量空间模型 INTERNET 卫生装备 信息搜集
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基于新的边缘保真项的有偏法向梯度向量流snakes模型
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作者 翟鹏飞 石成英 《计算机应用》 CSCD 北大核心 2016年第A02期160-164,共5页
梯度向量流(GVF)有效解决了主动轮廓(snakes)模型初始化和凹陷区域收敛的问题,但由于其各向同性的扩散特性,使得对弱边缘和角点的捕获能力不足。因此,致力于寻求一种GVF各向异性扩散机制。通过将拉普拉斯算子进行正交分解,分析了GVF模... 梯度向量流(GVF)有效解决了主动轮廓(snakes)模型初始化和凹陷区域收敛的问题,但由于其各向同性的扩散特性,使得对弱边缘和角点的捕获能力不足。因此,致力于寻求一种GVF各向异性扩散机制。通过将拉普拉斯算子进行正交分解,分析了GVF模型的法向和切向扩散作用,发现(类似)角点处的GVF场存在明显的曲率收缩和切向退化,进一步揭示了角点和弱边缘丢失的原因。在此基础上,通过对法向GVF(NGVF)模型引入新的边缘保真项和有偏的权重系数,提出一种新的外力模型。最后,通过实验对该方法的分割准确性和计算效率进行了比较分析。实验结果表明,该方法在保持一定计算优势同时,能准确地捕获弱边缘和角点。 展开更多
关键词 梯度向量 曲率收缩 切向退化 角点和弱边缘保持 向梯度向量模型 SNAKES模型
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有向地理信息要素方向的自动推演方法研究
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作者 江宁 王慧 《浙江测绘》 2022年第4期5-9,共5页
为解决地理空间数据库中有向要素空间冲突检测和推演自动化问题,在空间关系理论和有向线模型的指导下,提出一种基于法向量模型的有向线方向推演算法,能够实现有向要素方向的自动化推演,为提升地理信息数据生产效率和质量提供了解决方案。
关键词 有向要素 法向量模型 方向自动推演
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基于投入产出模型对机场出租车决策的研究
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作者 高志旭 何则浒 《科技创新与应用》 2020年第16期66-67,69,共3页
针对机场出租车司机决策及资源配置问题,文章综合考虑出租车司机和乘客双重效益,把出租车司机的决策过程看作对投入产出预估进而决策的过程,建立投入产出系统及向量法决策模型,应用Poisson分布、基于Delphi法改进后的AHP等方法量化各指... 针对机场出租车司机决策及资源配置问题,文章综合考虑出租车司机和乘客双重效益,把出租车司机的决策过程看作对投入产出预估进而决策的过程,建立投入产出系统及向量法决策模型,应用Poisson分布、基于Delphi法改进后的AHP等方法量化各指标,分析得到决策方案。并选取2017年首都机场的实际相关数据,结合圈层外推法,对模型进行检验,验证了模型的有效性。该模型可更好地对机场出租车司机的决策进行量化研究,也可以为机场制定相关政策提供可靠依据。 展开更多
关键词 向量决策模型 改进AHP POISSON分布 选择策略
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基于词频统计的个性化信息过滤技术 被引量:12
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作者 张国印 陈先 皮鹏 《哈尔滨工程大学学报》 EI CAS CSCD 2003年第1期63-67,共5页
对Internet信息进行过滤,筛选出与用户兴趣最相符的文档,是智能搜索引擎要解决的一个重要问题.本文在介绍搜索引擎基本原理的基础上,提出了一种文档学习和用户个性词典构建的实现方法,其中包括内码转换、分词、摘词处理、用户个性词典... 对Internet信息进行过滤,筛选出与用户兴趣最相符的文档,是智能搜索引擎要解决的一个重要问题.本文在介绍搜索引擎基本原理的基础上,提出了一种文档学习和用户个性词典构建的实现方法,其中包括内码转换、分词、摘词处理、用户个性词典的构建及词条权值调整等环节.然后提出了一种基于词频统计的个性化文档过滤算法,该算法对传统的向量空间模型法做了改进,使之能够更好地计算文档与用户个性词典之间的相关度,根据用户的兴趣爱好对文档进行相关度的过滤、排序,并给出了实验数据.实验结果表明该方法较好地解决了智能搜索引擎中Internet信息过滤、排序的问题. 展开更多
关键词 搜索引擎 文档过滤 向量空间模型 词频统计 个性词典
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个性化信息服务中的内容过滤技术研究
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作者 张宇光 鞠彦辉 《情报科学》 CSSCI 北大核心 2005年第1期131-133,共3页
本文通过资源的表达、用户兴趣文件的表达和匹配技术来研究矢量空间模型表示法和概率模型表示法 ,提出了一个改进的概率模型表示法 。
关键词 信息过滤 向量空间模型表示 概率模型表示
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A Novel Feature-based Method for Sentiment Analysis of Chinese Product Reviews 被引量:5
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作者 LIU Lizhen SONG Wei +2 位作者 WANG Hanshi LI Chuchu LU Jingli 《China Communications》 SCIE CSCD 2014年第3期154-164,共11页
Sentiment analysis of online reviews and other user generated content is an important research problem for its wide range of applications.In this paper,we propose a feature-based vector model and a novel weighting alg... Sentiment analysis of online reviews and other user generated content is an important research problem for its wide range of applications.In this paper,we propose a feature-based vector model and a novel weighting algorithm for sentiment analysis of Chinese product reviews.Specifically,an opinionated document is modeled by a set of feature-based vectors and corresponding weights.Different from previous work,our model considers modifying relationships between words and contains rich sentiment strength descriptions which are represented by adverbs of degree and punctuations.Dependency parsing is applied to construct the feature vectors.A novel feature weighting algorithm is proposed for supervised sentiment classification based on rich sentiment strength related information.The experimental results demonstrate the effectiveness of the proposed method compared with a state of the art method using term level weighting algorithms. 展开更多
关键词 sentiment analysis sentimentstrength opinion mining dependency parsing
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Optimization of support vector machine power load forecasting model based on data mining and Lyapunov exponents 被引量:7
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作者 牛东晓 王永利 马小勇 《Journal of Central South University》 SCIE EI CAS 2010年第2期406-412,共7页
According to the chaotic and non-linear characters of power load data,the time series matrix is established with the theory of phase-space reconstruction,and then Lyapunov exponents with chaotic time series are comput... According to the chaotic and non-linear characters of power load data,the time series matrix is established with the theory of phase-space reconstruction,and then Lyapunov exponents with chaotic time series are computed to determine the time delay and the embedding dimension.Due to different features of the data,data mining algorithm is conducted to classify the data into different groups.Redundant information is eliminated by the advantage of data mining technology,and the historical loads that have highly similar features with the forecasting day are searched by the system.As a result,the training data can be decreased and the computing speed can also be improved when constructing support vector machine(SVM) model.Then,SVM algorithm is used to predict power load with parameters that get in pretreatment.In order to prove the effectiveness of the new model,the calculation with data mining SVM algorithm is compared with that of single SVM and back propagation network.It can be seen that the new DSVM algorithm effectively improves the forecast accuracy by 0.75%,1.10% and 1.73% compared with SVM for two random dimensions of 11-dimension,14-dimension and BP network,respectively.This indicates that the DSVM gains perfect improvement effect in the short-term power load forecasting. 展开更多
关键词 power load forecasting support vector machine (SVM) Lyapunov exponent data mining embedding dimension feature classification
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Support vector machine forecasting method improved by chaotic particle swarm optimization and its application 被引量:11
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作者 李彦斌 张宁 李存斌 《Journal of Central South University》 SCIE EI CAS 2009年第3期478-481,共4页
By adopting the chaotic searching to improve the global searching performance of the particle swarm optimization (PSO), and using the improved PSO to optimize the key parameters of the support vector machine (SVM) for... By adopting the chaotic searching to improve the global searching performance of the particle swarm optimization (PSO), and using the improved PSO to optimize the key parameters of the support vector machine (SVM) forecasting model, an improved SVM model named CPSO-SVM model was proposed. The new model was applied to predicting the short term load, and the improved effect of the new model was proved. The simulation results of the South China Power Market’s actual data show that the new method can effectively improve the forecast accuracy by 2.23% and 3.87%, respectively, compared with the PSO-SVM and SVM methods. Compared with that of the PSO-SVM and SVM methods, the time cost of the new model is only increased by 3.15 and 4.61 s, respectively, which indicates that the CPSO-SVM model gains significant improved effects. 展开更多
关键词 chaotic searching particle swarm optimization (PSO) support vector machine (SVM) short term load forecast
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Forecasting of wind velocity:An improved SVM algorithm combined with simulated annealing 被引量:2
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作者 刘金朋 牛东晓 +1 位作者 张宏运 王官庆 《Journal of Central South University》 SCIE EI CAS 2013年第2期451-456,共6页
Accurate forecasting of wind velocity can improve the economic dispatch and safe operation of the power system. Support vector machine (SVM) has been proved to be an efficient approach for forecasting. According to th... Accurate forecasting of wind velocity can improve the economic dispatch and safe operation of the power system. Support vector machine (SVM) has been proved to be an efficient approach for forecasting. According to the analysis with support vector machine method, the drawback of determining the parameters only by experts' experience should be improved. After a detailed description of the methodology of SVM and simulated annealing, an improved algorithm was proposed for the automatic optimization of parameters using SVM method. An example has proved that the proposed method can efficiently select the parameters of the SVM method. And by optimizing the parameters, the forecasting accuracy of the max wind velocity increases by 34.45%, which indicates that the new SASVM model improves the forecasting accuracy. 展开更多
关键词 wind velocity forecasting improved algorithm simulated annealing support vector machine
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A new approach to test generation for combinational circuits
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作者 赵春晖 侯艳丽 +1 位作者 胡佳伟 兰海燕 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2009年第1期61-65,共5页
Aimed at the generation of high-quality test set in the shortest possible time, the test generation for combinational circuits (CC) based on the chaotic particle swarm optimization (CPSO) algorithm is presented ac... Aimed at the generation of high-quality test set in the shortest possible time, the test generation for combinational circuits (CC) based on the chaotic particle swarm optimization (CPSO) algorithm is presented according to the analysis of existent problems of CC test generation, and an appropriate CPSO algorithm model has been constructed. With the help of fault simulator, the test set of ISCAS' 85 benchmark CC is generated using the CPSO, and some techniques are introduced such as half-random generation, and simulation of undetected fauhs.with original test vector, and inverse test vector. Experimental results show that this algorithm can generate the same fault coverage and small-size test set in short time compared with other known similar methods, which proves that the proposed method is applicable and effective. 展开更多
关键词 test generation combinational circuits: particle swarm ootimization: chaotic ontimization
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Self-contained eigenvector algorithm applied to the identification of aerodynamic derivatives of bridge model 被引量:3
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作者 ZHANG XiaoXu CHEN LiFen SONG HanWen 《Science China(Technological Sciences)》 SCIE EI CAS 2011年第5期1134-1140,共7页
On one hand, when the bridge stays in a windy environment, the aerodynamic power would reduce it to act as a non-classic system. Consequently, the transposition of the system’s right eigenmatrix will not equal its le... On one hand, when the bridge stays in a windy environment, the aerodynamic power would reduce it to act as a non-classic system. Consequently, the transposition of the system’s right eigenmatrix will not equal its left eigenmatrix any longer. On the other hand, eigenmatrix plays an important role in model identification, which is the basis of the identification of aerodynamic derivatives. In this study, we follow Scanlan’s simple bridge model and utilize the information provided by the left and right eigenmatrixes to structure a self-contained eigenvector algorithm in the frequency domain. For the purpose of fitting more accurate transfer function, the study adopts the combined sine-wave stimulation method in the numerical simulation. And from the simulation results, we can conclude that the derivatives identified by the self-contained eigenvector algorithm are more dependable. 展开更多
关键词 bridge model aerodynamic derivatives eigenvector modal analysis parameter identification
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A HYBRID PSO-SA OPTIMIZING APPROACH FOR SVM MODELS IN CLASSIFICATION
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作者 HUIYAN JIANG LINGBO ZOU 《International Journal of Biomathematics》 2013年第5期189-206,共18页
Support vector machine (SVM) is a widely used tool in the field of image processing and pattern recognition. However, the parameters selection of SVMs is a dilemma in disease identification and clinical diagnosis. T... Support vector machine (SVM) is a widely used tool in the field of image processing and pattern recognition. However, the parameters selection of SVMs is a dilemma in disease identification and clinical diagnosis. This paper proposed an improved parameter optimization method based on traditional particle swarm optimization (PSO) algorithm by changing the fitness function in the traditional evolution process of SVMs. Then, this PSO method was combined with simulated annealing global searching algorithm to avoid local convergence that traditional PSO algorithms usually run into. And this method has achieved better results which reflected in the receiver-operating characteristic curves in medical images classification and has gained considerable identification accuracy in clinical disease detection. 展开更多
关键词 Support vector machine disease detection global optimization.
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