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基于矢量化运算模式的电力系统潮流计算 被引量:12
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作者 苏津 阳育德 覃智君 《电网技术》 EI CSCD 北大核心 2008年第3期88-92,共5页
通过把电力系统潮流方程的求解转化为一个新的非线性规划模型的求解,解决了病态系统潮流计算发散的问题,为给定条件下的潮流计算是否有解提供了一个新的判断途径。利用牛顿法获得具有对称不定系数矩阵的修正方程后,采用AMD算法对系数矩... 通过把电力系统潮流方程的求解转化为一个新的非线性规划模型的求解,解决了病态系统潮流计算发散的问题,为给定条件下的潮流计算是否有解提供了一个新的判断途径。利用牛顿法获得具有对称不定系数矩阵的修正方程后,采用AMD算法对系数矩阵进行排序,并采用LDLT算法进行求解,提高了修正方程的求解速度。整个潮流计算模型以矢量化形式表达,简化了程序复杂度,提高了代码的通用性和易维护性。对节点数从118到703共3个测试系统进行了仿真计算,结果验证了文中所提方法的正确性。 展开更多
关键词 电力系统 潮流计算 矢量化计算 非线性规划
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以编译为导向的Matrix-DSP程序分析与优化 被引量:2
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作者 荀长庆 陈照云 +2 位作者 文梅 孙海燕 马奕民 《计算机工程与科学》 CSCD 北大核心 2020年第10期1791-1800,共10页
数字信号处理器(DSP)在图像处理、自动化控制、信号处理等多个领域具有广泛应用。自主研发的Matrix DSP采用了典型的单指令多数据SIMD+超长指令字VLIW的向量化架构,因此面向该架构如何实现高效的向量化编程与优化是一项重要挑战。基于Ma... 数字信号处理器(DSP)在图像处理、自动化控制、信号处理等多个领域具有广泛应用。自主研发的Matrix DSP采用了典型的单指令多数据SIMD+超长指令字VLIW的向量化架构,因此面向该架构如何实现高效的向量化编程与优化是一项重要挑战。基于Matrix DSP的体系结构特点,以编译器性能为导向,对内核级代码常用的分析优化手段进行梳理和总结,并结合一个通用矩阵乘的例子进行展示,其执行性能可最高提升1个数量级。最后,从编译器优化和程序员高效编程的角度提出了一些后续的思考与讨论。 展开更多
关键词 Matrix DSP 向量化编程 程序优化 编译器
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空间桁架有限元分析向量化编程技术研究 被引量:2
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作者 刘磊 刚宪约 柴山 《山东理工大学学报(自然科学版)》 CAS 2008年第2期1-4,共4页
利用基于MATLAB的向量化编程方法,研究了空间桁架有限元分析中单元刚度矩阵形成、边界条件处理、单元应力与约束反力求解等关键问题的编程技术,所编程序具有语句简洁、数学物理意义清晰和运行效率高的优点,可以方便地应用于桁架结构的... 利用基于MATLAB的向量化编程方法,研究了空间桁架有限元分析中单元刚度矩阵形成、边界条件处理、单元应力与约束反力求解等关键问题的编程技术,所编程序具有语句简洁、数学物理意义清晰和运行效率高的优点,可以方便地应用于桁架结构的工程计算和有限元教学. 展开更多
关键词 桁架 有限元 向量化编程
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Matlab编程技巧二则 被引量:1
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作者 代西武 《北京建筑工程学院学报》 2008年第2期59-60,63,共3页
通过两个示例,研究了Matlab编程的向量化方法,并且与一般的编程方法进行比较,发现向量化编程确实很简单.
关键词 MATLAB 向量化 编程
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基于动态规划的自动向量化方法 被引量:1
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作者 吕鹏伟 刘从新 +1 位作者 赵一明 沈绪榜 《北京理工大学学报》 EI CAS CSCD 北大核心 2017年第5期544-550,共7页
由于SLP自动向量化算法使用的启发式策略会丢失一定的向量化机会,本文提出一种基于动态规划的自动向量化方法DPSLP,该方法采用比SLP更加激进的策略在基本块内寻找候选的SIMD指令分组,依据动态规划方程计算指令分组的代价并从众多指令分... 由于SLP自动向量化算法使用的启发式策略会丢失一定的向量化机会,本文提出一种基于动态规划的自动向量化方法DPSLP,该方法采用比SLP更加激进的策略在基本块内寻找候选的SIMD指令分组,依据动态规划方程计算指令分组的代价并从众多指令分组中选择最优的分组进行向量化转换.实验结果显示,DPSLP与SLP相比测试程序的运行时间平均减少了8%,静态指令代价平均减少10%,平均向量宽度增加66.4%. 展开更多
关键词 自动向量化 动态规划 指令代价
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基于小波变换和压缩感知的低速率语音编码方案 被引量:23
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作者 叶蕾 杨震 郭海燕 《仪器仪表学报》 EI CAS CSCD 北大核心 2010年第7期1569-1575,共7页
本文提出一种新的低速率语音编码方案,基于语音信号小波变换高频系数的稀疏性,利用压缩感知原理,将小波变换高频系数进行压缩感知投影成数据量大大减少的观测序列,然后对观测序列采用码激励线性预测技术进行编解码,根据解码后的观测序列... 本文提出一种新的低速率语音编码方案,基于语音信号小波变换高频系数的稀疏性,利用压缩感知原理,将小波变换高频系数进行压缩感知投影成数据量大大减少的观测序列,然后对观测序列采用码激励线性预测技术进行编解码,根据解码后的观测序列,利用线性规划技术对小波变换高频系数进行重构,小波变换低频系数采用矢量量化技术编解码,并采用后置低通滤波器改善解码后小波高低频系数合成语音的听觉效果。该编码方案在低数码率(2.64~3.5 Kb/s)时得到的重构语音平均MOS分为3.0~3.4,达到4.8 Kb/s码激励线性预测语音编码质量。 展开更多
关键词 小波变换 压缩感知 码激励线性预测 矢量量化 线性规划
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一种新型支持向量机 被引量:8
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作者 杨强 吴中福 +1 位作者 余萍 钟将 《重庆大学学报(自然科学版)》 EI CAS CSCD 北大核心 2005年第2期81-84,共4页
讨论了现有的用于分类的支持向量机 (SVM)所确定的边界在抗干扰方面的局限性。在此基础之上提出了一种新型支持向量机,即基于边界调节的支持向量机,并利用K-T条件得到了这种支持向量机的对偶目标函数。通过对人工数据集和真实数据集的... 讨论了现有的用于分类的支持向量机 (SVM)所确定的边界在抗干扰方面的局限性。在此基础之上提出了一种新型支持向量机,即基于边界调节的支持向量机,并利用K-T条件得到了这种支持向量机的对偶目标函数。通过对人工数据集和真实数据集的仿真实验表明,相对于L1-SVM而言,基于边界调节的支持向量机具有更少的支持向量和更好的推广性能。 展开更多
关键词 支持向量机SVM 最优超平面 核函数 二次规划
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AHP中排序向量的LAM算法 被引量:5
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作者 杜之韩 《系统工程》 CSCD 1995年第6期62-65,共4页
本文提出求解AHP中判断矩阵的排序向量的新思路,并由此获得一个较为简捷的计算排序向量的新算法——最小夹角法(LAM).运用LAM,使用者只须用计算器就可获得相当精确的排序向量.
关键词 判断矩阵 排序向量 层次分析法 最小夹角法
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Sentiment Analysis with Tweets Behaviour in Twitter Streaming API 被引量:1
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作者 Kuldeep Chouhan Mukesh Yadav +4 位作者 Ranjeet Kumar Rout Kshira Sagar Sahoo NZ Jhanjhi Mehedi Masud Sultan Aljahdali 《Computer Systems Science & Engineering》 SCIE EI 2023年第5期1113-1128,共16页
Twitter is a radiant platform with a quick and effective technique to analyze users’perceptions of activities on social media.Many researchers and industry experts show their attention to Twitter sentiment analysis t... Twitter is a radiant platform with a quick and effective technique to analyze users’perceptions of activities on social media.Many researchers and industry experts show their attention to Twitter sentiment analysis to recognize the stakeholder group.The sentiment analysis needs an advanced level of approaches including adoption to encompass data sentiment analysis and various machine learning tools.An assessment of sentiment analysis in multiple fields that affect their elevations among the people in real-time by using Naive Bayes and Support Vector Machine(SVM).This paper focused on analysing the distinguished sentiment techniques in tweets behaviour datasets for various spheres such as healthcare,behaviour estimation,etc.In addition,the results in this work explore and validate the statistical machine learning classifiers that provide the accuracy percentages attained in terms of positive,negative and neutral tweets.In this work,we obligated Twitter Application Programming Interface(API)account and programmed in python for sentiment analysis approach for the computational measure of user’s perceptions that extract a massive number of tweets and provide market value to the Twitter account proprietor.To distinguish the results in terms of the performance evaluation,an error analysis investigates the features of various stakeholders comprising social media analytics researchers,Natural Language Processing(NLP)developers,engineering managers and experts involved to have a decision-making approach. 展开更多
关键词 Machine learning Naive Bayes natural language processing sentiment analysis social media analytics support vector machine Twitter application programming interface
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局部区域模型垂线偏差快速算法 被引量:5
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作者 邢志斌 李姗姗 +3 位作者 曲政豪 王伟 范昊鹏 贾鲁 《测绘科学》 CSCD 北大核心 2015年第12期38-43,共6页
针对利用地球重力场模型计算大范围、高分辨率局部区域模型垂线偏差速度慢这一问题,该文在对位系数模型泰勒级数展开的基础上,提出了采用向量运算、混合编程、预先计算缔合勒让德函数Belikov递推方法中与经纬度无关量的方法;最后与严密... 针对利用地球重力场模型计算大范围、高分辨率局部区域模型垂线偏差速度慢这一问题,该文在对位系数模型泰勒级数展开的基础上,提出了采用向量运算、混合编程、预先计算缔合勒让德函数Belikov递推方法中与经纬度无关量的方法;最后与严密公式计算结果作对比。实验结果表明,该方法不仅可以满足精度要求,而且可以有效提高计算速度。 展开更多
关键词 模型垂线偏差 泰勒级数展开 向量运算 混合编程 预先计算
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基向量变化的灵敏度分析 被引量:2
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作者 李敏 夏少刚 魏华 《大连海事大学学报》 CAS CSCD 1996年第1期101-104,共4页
采用一定技巧和简捷的方法,对基向量变化的灵敏度作了分析,从根本上改进了文献[1]的作法.
关键词 基向量 线性规划 灵敏度 分析
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五轴机床的RTCP功能开发与应用研究 被引量:4
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作者 刘沛 刘静文 黄玉彤 《制造技术与机床》 北大核心 2021年第5期151-157,共7页
RTCP功能是五轴机床的一种重要的标志性功能,高档数控系统开发时RTCP功能属于必备功能。高档数控系统的RTCP功能不能仅是基本的RTCP功能,还需要支持多结构机床、倾斜旋转轴、3+2斜面加工以及矢量插补等高级插补功能。总结了整个RTCP功... RTCP功能是五轴机床的一种重要的标志性功能,高档数控系统开发时RTCP功能属于必备功能。高档数控系统的RTCP功能不能仅是基本的RTCP功能,还需要支持多结构机床、倾斜旋转轴、3+2斜面加工以及矢量插补等高级插补功能。总结了整个RTCP功能开发的各个方面,对数控系统的RTCP功能开发具有一定的指导意义。 展开更多
关键词 五轴机床 RTCP 矢量编程
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An Improved HVQ Algorithm for Compression and Rendering of Space Environment Volume Data with Multi-correlated Variables
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作者 BAO Lili CAI Yanxia +2 位作者 WANG Rui ZOU Yenan SHI Liqin 《空间科学学报》 CAS CSCD 北大核心 2023年第4期780-785,共6页
Volume visualization can not only illustrate overall distribution but also inner structure and it is an important approach for space environment research.Space environment simulation can produce several correlated var... Volume visualization can not only illustrate overall distribution but also inner structure and it is an important approach for space environment research.Space environment simulation can produce several correlated variables at the same time.However,existing compressed volume rendering methods only consider reducing the redundant information in a single volume of a specific variable,not dealing with the redundant information among these variables.For space environment volume data with multi-correlated variables,based on the HVQ-1d method we propose a further improved HVQ method by compositing variable-specific levels to reduce the redundant information among these variables.The volume data associated with each variable is divided into disjoint blocks of size 43 initially.The blocks are represented as two levels,a mean level and a detail level.The variable-specific mean levels and detail levels are combined respectively to form a larger global mean level and a larger global detail level.To both global levels,a splitting based on a principal component analysis is applied to compute initial codebooks.Then,LBG algorithm is conducted for codebook refinement and quantization.We further take advantage of progressive rendering based on GPU for real-time interactive visualization.Our method has been tested along with HVQ and HVQ-1d on high-energy proton flux volume data,including>5,>10,>30 and>50 MeV integrated proton flux.The results of our experiments prove that the method proposed in this paper pays the least cost of quality at compression,achieves a higher decompression and rendering speed compared with HVQ and provides satisficed fidelity while ensuring interactive rendering speed. 展开更多
关键词 Compressed volume rendering Multi-correlated variables Space environment vector quantization GPU programming
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Prediction of coal ash fusion temperatures using computational intelligence based models 被引量:3
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作者 Sanjeev S.Tambe Makarand Naniwadekar +2 位作者 Shishir Tivvary Ashis Mukherjee Tarit Baran Das 《International Journal of Coal Science & Technology》 EI 2018年第4期486-507,共22页
In the coal-based combustion and gasification processes, the mineral matter contained in the coal (predominantly oxides), is left as an incombustible residue, termed ash. Commonly, ash deposits are formed on the heat ... In the coal-based combustion and gasification processes, the mineral matter contained in the coal (predominantly oxides), is left as an incombustible residue, termed ash. Commonly, ash deposits are formed on the heat absorbing surfaces of the exposed equipment of the combustion/gasification processes. These deposits lead to the occurrence of slagging or fouling and. consequently, reduced process efficiency. The ash fusion temperatures (AFTs) signify the temperature range over which the ash deposits are formed on the heat absorbing surfaces of the process equipment. Thus, for designing and operating the coal-based processes, it is important to have mathematical models predicting accurately the four types of AFTs namely initial deformation temperature, softening temperature, hemispherical temperature, and flow temperature. Several linear/nonlinear models with varying prediction accuracies and complexities are available for the AFT prediction. Their principal drawback is their applicability to the coals originating from a limited number of geographical regions. Accordingly, this study presents computational intelligenee (CI) based nonlinear models to predict the four AFTs using the oxide composition of the coal ash as the model input. The CI methods used in the modeling are genetic programming (GP), artificial neural networks, and support vector regression. The no table features of this study are that the models with a better AFT prediction and generalization performanee, a wider application potential, and reduced complexity, have been developed. Among the Ci-based models, GP and MLP based models have yielded overall improved performanee in predicting all four AFTs. 展开更多
关键词 ASH fusion temperature Artificial NEURAL networks Support vector regression GENETIC programming DATA-DRIVEN modeling
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Dynamic forecasting and optimal scheduling of by-product gases in integrated iron and steel works 被引量:3
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作者 Qi Zhang Hui Li +4 位作者 Jia-lin Ma Hua-yan Xu Bo-yang Yu Gang Wang Shan Jiang 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2019年第5期529-546,共18页
The by-product gases, which are generated in ironmaking, coking and steel making processes, can be used as fuel for the metallurgical processes and on-site power plants. However, if the supply and demand of by-product... The by-product gases, which are generated in ironmaking, coking and steel making processes, can be used as fuel for the metallurgical processes and on-site power plants. However, if the supply and demand of by-product gases are imbalanced, gas flaring may occur, leading to energy wastage and environmental pollution. Therefore, optimal scheduling of by-product gases is important in iron and steel works. A BP_LSSVM model, which combines back-propagation (BP) neural network and least squares support vector machine (LSSVM), and an improved mixed integer linear programming model were proposed to forecast the surplus gases and allocate them optimally. To maximize energy utilization, the stability of gas holders and boilers was considered and a concise heuristic procedure was proposed to assign penalties for boilers and gas holders. Moreover, the optimal level of gas holder was studied to enhance the stability of the gas system. Compared to the manual operation, the optimal results showed that the electricity generated by the power plant increased by 2.93% in normal condition and by 22.2% in overhaul condition. The proposed model minimizes the total cost by optimizing the boiler load with less adjustment frequency and the stability of gas holders and can be used as a guidance in dynamic forecasting and optimal scheduling of by-product gases in integrated iron and steel works. 展开更多
关键词 Iron and steel WORKS BACK-PROPAGATION neural network Least SQUARES support vector machine Mixed INTEGER linear programming Dynamic forecasting Optimal scheduling
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The Uniqueness of Major Efficient Solution for Multiobjective Programming Problem
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作者 KONG Xiang\|qing Zhejiang Economic College, Jiaxing 314001, China 《Systems Science and Systems Engineering》 CSCD 2000年第1期125-128,共4页
In this paper, weak strictly convex vector function and weak strictly H\-α convex vector function are introduced. We prove the uniqueness of major efficient solution when the objective function is weak strictly c... In this paper, weak strictly convex vector function and weak strictly H\-α convex vector function are introduced. We prove the uniqueness of major efficient solution when the objective function is weak strictly convex vector function, and the uniqueness of α major efficient solution when the objective function is weak strictly H α convex vector function. 展开更多
关键词 multiobjective programming weak strictly convex vector function weak strictly H α convex vector function major efficient solution
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On First Order Optimality Conditions for Vector Optimization 被引量:1
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作者 L.M.Gra■a Drummond A.N.Iusem B.F.Svaiter 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2003年第3期371-386,共16页
We develop first order optimality conditions for constrained vector optimization. The partial orders for the objective and the constraints are induced by closed and convex cones with nonempty interior. After presentin... We develop first order optimality conditions for constrained vector optimization. The partial orders for the objective and the constraints are induced by closed and convex cones with nonempty interior. After presenting some well known existence results for these problems, based on a scalarization approach, we establish necessity of the optimality conditions under a Slater-like constraint qualification, and then sufficiency for the K-convex case. We present two alternative sets of optimality conditions, with the same properties in connection with necessity and sufficiency, but which are different with respect to the dimension of the spaces to which the dual multipliers belong. We introduce a duality scheme, with a point-to-set dual objective, for which strong duality holds. Some examples and open problems for future research are also presented. 展开更多
关键词 Cone constraints vector optimization Pareto minimization first order optimality conditions convex programming DUALITY
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异构传感器网络多目标多重覆盖策略 被引量:2
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作者 罗旭 柴利 杨君 《电子与信息学报》 EI CSCD 北大核心 2014年第3期690-695,共6页
在传感器网络环境监测应用中,常存在多种监测对象。此类应用中,每个异构网络节点搭配不同类型的传感器,要求网络部署可多重覆盖监测区以监测各个子对象。针对节点随机分布的传感器网络,该文提出一种平均子网寿命模型以评价网络中某子对... 在传感器网络环境监测应用中,常存在多种监测对象。此类应用中,每个异构网络节点搭配不同类型的传感器,要求网络部署可多重覆盖监测区以监测各个子对象。针对节点随机分布的传感器网络,该文提出一种平均子网寿命模型以评价网络中某子对象的监测寿命。在给定成本预算与各子对象的基本覆盖率需求下,采用一种基于整数向量规划的多目标多重覆盖算法权衡成本、网络覆盖性能以及网络中不同子对象的监测寿命。该算法分两部分,首先确定监测不同子对象的传感器数量,然后基于平均子网寿命模型,确定不同类型的异构节点数量。针对向量规划问题,文中给出两种不同次优解法。在仿真实验部分,将不同次优解法进行了对比,并分析了算法计算复杂度。仿真示例验证了该文的覆盖算法在多对象监测应用中的有效性。 展开更多
关键词 传感器网络 多对象监测 平均子网寿命 向量规划 异构节点
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基于压缩感知的低速率语音编码新方案 被引量:2
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作者 叶蕾 杨震 孙林慧 《仪器仪表学报》 EI CAS CSCD 北大核心 2011年第12期2688-2692,共5页
利用语音小波高频系数的稀疏性和压缩感知原理,提出一种新的基于压缩感知的低速率语音编码方案,其中小波高频系数的压缩感知重构分别采用l1范数优化方案及码本预测方案进行,前者对大幅度样值重构效果较好,且不仅适用于语音,也适用于音... 利用语音小波高频系数的稀疏性和压缩感知原理,提出一种新的基于压缩感知的低速率语音编码方案,其中小波高频系数的压缩感知重构分别采用l1范数优化方案及码本预测方案进行,前者对大幅度样值重构效果较好,且不仅适用于语音,也适用于音乐信号,具有传统的线性预测编码方法无法比拟的优势,后者对稀疏系数位置的估计较好,且不需要采用压缩感知重构常用的基追踪算法或匹配追踪算法,从而减少了计算量。两种方法的联合使用能发挥各自的优势,使得重构语音的音质进一步改善。 展开更多
关键词 小波变换 压缩感知 矢量量化 线性规划
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三维空间小孔电火花编程加工工艺方法研究 被引量:2
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作者 李树枫 徐佩 +1 位作者 陈阳 王增坤 《电加工与模具》 2015年第A01期44-46,53,共4页
结合国内多轴电火花小孔加工机床的特点,利用UG建模工具获取三维空间小孔的位置与矢量信息,巧妙地利用接触感知功能得到设备回转轴的回转偏差,最后通过坐标变换获得对随机分布的空间矢量小孔精准定位的电火花加工方案。
关键词 电火花小孔加工 坐标变换 矢量编程
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