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直标尺代替圆标尺而引入的读数误差
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作者 何克明 徐理中 《浙江大学学报(理学版)》 CAS CSCD 1995年第S1期93-93,共1页
本文导出了一个由直标尺代替圆标尺而引入的读数误差修正式.
关键词 读数误差 圆标 冲击电流计 尺零点 镜式检流计 修正式 磁感强度 螺线管 使用说明书 伸长法
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近景摄影测量中圆标靶圆心提取的方法 被引量:1
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作者 鄢咏折 黄先锋 +1 位作者 张帆 范晓燕 《地理空间信息》 2018年第10期94-97,共4页
对近景摄影测量中常使用的圆形标靶,提出了一种识别并提取圆心的方法。该方法通过二值化、区域增长、边缘点提取、最小二乘拟合等一系列图像处理后,最终实现圆标靶的识别及提取。实验结果验证了该方法的可行性。
关键词 近景摄影测量 圆标 心提取
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黑龙江省获中国方圆标志认证委员会GB/T19000-ISO9000认证企业名录
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《质量天地》 2001年第1期17-17,共1页
2000年,我省企业积极贯彻GBT/1990-ISO9000族标准,建立健全企业质量体系,努力提高企业质量管理水平,实现与国际惯例接轨,以高质量的产品和科学的质量管理参与市场竞争。一年来,全省共有46家企业通过了中国... 2000年,我省企业积极贯彻GBT/1990-ISO9000族标准,建立健全企业质量体系,努力提高企业质量管理水平,实现与国际惯例接轨,以高质量的产品和科学的质量管理参与市场竞争。一年来,全省共有46家企业通过了中国方圆标志认证委员会黑龙江审核中心现场审核,加上前几年通过认证的企业,我省已有8家企业获得了中国方圆标志认证委员会GB/T19000-ISO900质量认证证书。现将获证企业名 单公布如下。 展开更多
关键词 GB/T19000-ISO9000 认证委员会 黑龙江省 中国方 认证证书 圆标 核中心 企业质量体系 管理参与 与国际惯例接轨
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变形模板匹配的圆标靶中心点优化方法
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作者 苟国华 李大军 +1 位作者 郭丙轩 陈志高 《测绘科学》 CSCD 北大核心 2020年第7期120-125,共6页
针对近景摄影测量常用的圆形标靶的中心点进行识别和定位时,如何提高圆标靶中心点提取的精准度问题,该文提出了一种基于变形模板匹配的优化方法,对初步识别的中心点做进一步优化,以此获得精准的标靶中心。该方法首先利用物体在相机中的... 针对近景摄影测量常用的圆形标靶的中心点进行识别和定位时,如何提高圆标靶中心点提取的精准度问题,该文提出了一种基于变形模板匹配的优化方法,对初步识别的中心点做进一步优化,以此获得精准的标靶中心。该方法首先利用物体在相机中的成像特点,模拟标靶成像时的状态,构造一个与目标所成之像高度相似的变形模板影像;然后以影像间的相关系数作为匹配测度,用这个模板在原始影像上进行滑动匹配,寻找到相关系数最大时的模板中心点坐标作为优化后的标靶中心点坐标;最后通过改变滑动的步距可将优化精度提升到子像素级。实验结果表明,优化后的标靶的中心点的精确度得到了明显的提高。 展开更多
关键词 圆标靶中心点优化 模板匹配 变形模板 相关系数 子像素级
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圆环式标靶在三维激光扫描法检定铁路罐车容积中的应用
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作者 沈明伟 李翠玲 +1 位作者 刘振忠 王红雨 《铁道技术监督》 2023年第10期25-28,共4页
Z坐标是通过扫描点云计算铁路罐车容积的基准点。采用三维激光扫描法检定铁路罐车时,需要通过扫描标靶获取检尺点的Z坐标。设计一款圆环式标靶,使激光束直接在铁路罐车罐体内表面反射,应用这种标靶,在后期计算时无需输入标靶高度,而且... Z坐标是通过扫描点云计算铁路罐车容积的基准点。采用三维激光扫描法检定铁路罐车时,需要通过扫描标靶获取检尺点的Z坐标。设计一款圆环式标靶,使激光束直接在铁路罐车罐体内表面反射,应用这种标靶,在后期计算时无需输入标靶高度,而且圆环式标靶具有质量轻、易于平衡放置等优点。对圆环式标靶,与采用圆锥式标靶扫描点云的容积计算结果进行比对,基本一致,符合测量结果不确定度要求。 展开更多
关键词 铁路罐车 容积检定 三维激光扫描法 环式
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管道内表面圆结构光视觉三维测量系统 被引量:22
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作者 王颖 张瑞 《红外与激光工程》 EI CSCD 北大核心 2014年第3期891-896,共6页
为保证管道运输安全,需要对管道进行定期维护和检测。采用视觉检测原理,提出了一种基于圆结构光三维视觉检测的管道内表面测量系统。针对管道内表面测量空间受限的约束,基于圆结构光视觉检测原理,提出了视觉传感器的纵向排列结构模式,... 为保证管道运输安全,需要对管道进行定期维护和检测。采用视觉检测原理,提出了一种基于圆结构光三维视觉检测的管道内表面测量系统。针对管道内表面测量空间受限的约束,基于圆结构光视觉检测原理,提出了视觉传感器的纵向排列结构模式,并搭建了管道内表面圆结构光视觉检测系统。针对圆结构光特点,设计了圆环形平面标定靶标,实现了圆结构光检测系统的标定,并基于该圆结构光视觉检测系统对工业管道内表面进行了三维测量。实验结果表明:该系统的标定不确定度为0.081 mm,针对管道内表面,具有较高的测量精度。 展开更多
关键词 激光投射器 系统校准 环靶 管道 视觉测量
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FINITE RANGE SET WITH TRUNCATED MULTIPLICITY FOR MEROMORPHIC FUNCTIONS ON SOME COMPLEX DISC
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作者 WANG Yu-ting CAO Hong-zhe 《数学杂志》 2024年第5期383-396,共14页
In this paper,we consider the truncated multiplicity finite range set problem of meromorphic functions on some complex disc.By using the value distribution theory of meromorphic functions,we establish a second main th... In this paper,we consider the truncated multiplicity finite range set problem of meromorphic functions on some complex disc.By using the value distribution theory of meromorphic functions,we establish a second main theorem for meromorphic functions with finite growth index which share meromorphic functions(may not be small functions).As its application,we also extend the result of a finite range set with truncated multiplicity. 展开更多
关键词 meromorphic functions finite growth index complex disc finite range set trun-cated multiplicity
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A stepwise camera calibration method incorporating compensation for eccentricity error
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作者 WEI Jiaqi WANG Peng +4 位作者 LI Yue LI Mojing LI Lin SUN Changku FU Luhua 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2024年第4期445-457,共13页
In visual measurement,high-precision camera calibration often employs circular targets.To address issues in mainstream methods,such as the eccentricity error of the circle from using the circle’s center for calibrati... In visual measurement,high-precision camera calibration often employs circular targets.To address issues in mainstream methods,such as the eccentricity error of the circle from using the circle’s center for calibration,overfitting or local minimum from fullparameter optimization,and calibration errors due to neglecting the center of distortion,a stepwise camera calibration method incorporating compensation for eccentricity error was proposed to enhance monocular camera calibration precision.Initially,the multiimage distortion correction method calculated the common center of distortion and coefficients,improving precision,stability,and efficiency compared to single-image distortion correction methods.Subsequently,the projection point of the circle’s center was compared with the center of the contour’s projection to iteratively correct the eccentricity error,leading to more precise and stable calibration.Finally,nonlinear optimization refined the calibration parameters to minimize reprojection error and boosts precision.These processes achieved stepwise camera calibration,which enhanced robustness.In addition,the module comparison experiment showed that both the eccentricity error compensation and the camera parameter optimization could improve the calibration precision,but the latter had a greater impact.The combined use of the two methods further improved the precision and stability.Simulations and experiments confirmed that the proposed method achieved high precision,stability,and robustness,suitable for high-precision visual measurements. 展开更多
关键词 camera calibration error compensation eccentricity error distortion correction center of distortion optical measurement
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让系统完整:找回WINDOWSXP的隐藏组件
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《软件》 2003年第3期58-59,共2页
Windows XP界面华丽功能多多,想必不少朋友都用着吧。可是你有没有发现Windows XP喜欢和我们玩儿捉迷蔵的游戏,一些原本在windows系统中应该出现的选项都不见了,甚至有时另一些选项会突然消火!其实它们都被Windows XP藏了起来,今天我们... Windows XP界面华丽功能多多,想必不少朋友都用着吧。可是你有没有发现Windows XP喜欢和我们玩儿捉迷蔵的游戏,一些原本在windows系统中应该出现的选项都不见了,甚至有时另一些选项会突然消火!其实它们都被Windows XP藏了起来,今天我们就来和Windows XP玩儿一把,找出这些被藏起来的项目。 展开更多
关键词 WINDOWSXP 组件 操作系统 系统托盘圆标 控制面板
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Circular L(j,k)-labeling numbers of trees and products of graphs 被引量:3
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作者 吴琼 林文松 《Journal of Southeast University(English Edition)》 EI CAS 2010年第1期142-145,共4页
Let j, k and m be three positive integers, a circular m-L(j, k)-labeling of a graph G is a mapping f: V(G)→{0, 1, …, m-1}such that f(u)-f(v)m≥j if u and v are adjacent, and f(u)-f(v)m≥k if u and v are... Let j, k and m be three positive integers, a circular m-L(j, k)-labeling of a graph G is a mapping f: V(G)→{0, 1, …, m-1}such that f(u)-f(v)m≥j if u and v are adjacent, and f(u)-f(v)m≥k if u and v are at distance two,where a-bm=min{a-b,m-a-b}. The minimum m such that there exists a circular m-L(j, k)-labeling of G is called the circular L(j, k)-labeling number of G and is denoted by σj, k(G). For any two positive integers j and k with j≤k,the circular L(j, k)-labeling numbers of trees, the Cartesian product and the direct product of two complete graphs are determined. 展开更多
关键词 circular L(j k)-labeling number TREE Cartesian product of graphs direct product of graphs
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Multi-solution of Semilinear Elliptic Equation on R^N
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作者 冯秀芳 郑驻军 +1 位作者 赵秀娥 郑君英 《Chinese Quarterly Journal of Mathematics》 CSCD 2001年第2期98-103,共6页
In this paper, we give a Z 2 index theory of generalized critical point. By this theory we get a sufficient condition on the existing result of a class functional, as an example we give a new result that the equa... In this paper, we give a Z 2 index theory of generalized critical point. By this theory we get a sufficient condition on the existing result of a class functional, as an example we give a new result that the equation-Δu+u=|u| p-1 u, x∈R N,(1)has infinite solutions. 展开更多
关键词 generalized critical point Z 2 index semilinear equation
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MWI in Cylindrical Coordinates and Its Application
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作者 谢袁春 高本庆 邓次平 《Journal of Beijing Institute of Technology》 EI CAS 2000年第2期176-182,共7页
Based on FDTD difference expressions and eigenfunctions of Maxwell functions in cylindrical coordinates, mesh wave impedances (MWIs) in 2D and 3D cylindrical coordinates were introduced. Combined with the concept of p... Based on FDTD difference expressions and eigenfunctions of Maxwell functions in cylindrical coordinates, mesh wave impedances (MWIs) in 2D and 3D cylindrical coordinates were introduced. Combined with the concept of perfectly matched layer (PML), MWI PML absorbing boundary condition (ABC) algorithm was deduced in 2D cylindrical coordinates. Numerical experiments were done to investigate the validity of MWI and its application in cylindrical coordinates FDTD algorithm. The results showed that MWI in cylindrical coordinates can be used to accurately calculate the numerical reflection error caused by different mesh increments in non uniform FDTD. MWI can also provide theoretical criterion to define the permitted variable range of mesh dimension. MWI PML ABC is easy to be applied and reduces low numerical reflection, which only causes a little higher reflection error compared with Teixeira's PML. 展开更多
关键词 mesh wave impedance cylindrical coordinates finite-difference time-domain perfectly matched layer absorbing boundary condition
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正确安装字体及警示音文件
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《桌面出版与设计》 1998年第3期59-59,共2页
关键词 正确安装 应用程序 字体 系统文件夹 重新启动 无法使用 三种方法 圆标 合文 按钮
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Flow of a Jeffery-Six Constant Fluid Between Coaxial Cylinders with Heat Transfer Analysis 被引量:1
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作者 Muhammad Yousaf Malik Azad Hussain Sohail Nadeem 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第8期345-351,共7页
In the present investigation we have discussed the flow of a Jeffrey-six constant incompressible fluid between two infinite coaxial cylinders in the presence of heat transfer analysis. The governing equations of Jeffr... In the present investigation we have discussed the flow of a Jeffrey-six constant incompressible fluid between two infinite coaxial cylinders in the presence of heat transfer analysis. The governing equations of Jeffrey-six constant fluid along with energy equation have been derived in cylindrical coordinates. The highly nonlinear equations are simplified with the help of non-dimensional parameters and then solved analytically with the help of homotopy analysis method (HAM) for two fundamental flows namely Couette and Generalized Couette flow. The effects of emerging parameters are discussed through graphs. The convergence of the HAM solution has been discussed by plotting h-curves. 展开更多
关键词 Jeffery-six constant fluid coaxial cylinders heat transfer analysis HAM solutions
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Standard and Economical Cascadic Multigrid Methods for the Mortar Finite Element Methods 被引量:3
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作者 Xuejun Xu Wenbin Chen 《Numerical Mathematics(Theory,Methods and Applications)》 SCIE 2009年第2期180-201,共22页
In this paper, standard and economical cascadic multigrid methods are considered for solving the algebraic systems resulting from the mortar finite element methods. Both cascadic multigrid methods do not need full ell... In this paper, standard and economical cascadic multigrid methods are considered for solving the algebraic systems resulting from the mortar finite element methods. Both cascadic multigrid methods do not need full elliptic regularity, so they can be used to tackle more general elliptic problems. Numerical experiments are reported to suonort our theorv. 展开更多
关键词 Cascadic multigrid mortar finite elements.
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A Heuristic Method of Scalar Multiplication of Elliptic Curve over OEF 被引量:1
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作者 刘铎 罗平 戴一奇 《Journal of Shanghai Jiaotong university(Science)》 EI 2006年第2期177-183,共7页
Elliptic curve cryptosystem is the focus of public key cryptology nowadays, for it has many advantages RSA lacks. This paper introduced a new heuristic algorithm on computing multiple scalar multiplications of a given... Elliptic curve cryptosystem is the focus of public key cryptology nowadays, for it has many advantages RSA lacks. This paper introduced a new heuristic algorithm on computing multiple scalar multiplications of a given point. Based on this algorithm, a new method of computing scalar multiplication of elliptic curve over optimal extension field (OEF) using Frobenius map was presented. The new method is more efficient than the traditional ones. In the last part of this paper, the comparison was given in the end. 展开更多
关键词 CRYPTOLOGY elliptic curve optimal extension field FROBENIUS
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Cylindrical coordinate measuring machines: probe offset and workpiece clamping error
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作者 QIU Zu-rong WANG Cheng-lin +4 位作者 SU Zhi-kun LI Hao-peng XUE Jie LI Xing-hua LU Yao-huan 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2019年第3期205-212,共8页
A cylindrical coordinate measuring machine for the detection of large-size rotational parts is introduced. The measuring machine can simultaneously measure the geometrical dimensions, form and position errors of the i... A cylindrical coordinate measuring machine for the detection of large-size rotational parts is introduced. The measuring machine can simultaneously measure the geometrical dimensions, form and position errors of the inner and outer surfaces. Since the maximum length of the workpiece can reach 2 000 mm , it is difficult to be clamped and adjusted and easy to produce clamping error. The eccentricity can be up to 1.5 mm, which has an interaction effect with the probe mounting offset. We mainly study the probe offset of the measuring machine and the influence of the workpiece clamping error on the measurement. A method of controlling the offset of the measuring probe is proposed. The effect of the clamping error is eliminated through the space coordinate transformation of the workpiece axis, and the axis is fitted by the least square method. Finally, a common fixture can be realized to meet the clamping requirements of the workpiece. 展开更多
关键词 rotational parts probe offset ECCENTRICITY cylindrical coordinate measuring machine
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SPEED UP RATIONAL POINT SCALAR MULTIPLICATIONS ON ELLIPTIC CURVES BY FROBENIUS EQUATIONS
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作者 You Lin Zhao Junzhong Xu Maozhi 《Journal of Electronics(China)》 2006年第1期58-63,共6页
Let q be a power of a prime and φ be the Frobenius endomorphism on E(Fqk), then q = tφ - φ^2. Applying this equation, a new algorithm to compute rational point scalar multiplications on elliptic curves by finding... Let q be a power of a prime and φ be the Frobenius endomorphism on E(Fqk), then q = tφ - φ^2. Applying this equation, a new algorithm to compute rational point scalar multiplications on elliptic curves by finding a suitable small positive integer s such that q^s can be represented as some very sparse φ-polynomial is proposed. If a Normal Basis (NB) or Optimal Normal Basis (ONB) is applied and the precomputations are considered free, our algorithm will cost, on average, about 55% to 80% less than binary method, and about 42% to 74% less than φ-ary method. For some elliptic curves, our algorithm is also taster than Mǖller's algorithm. In addition, an effective algorithm is provided for finding such integer s. 展开更多
关键词 Elliptic curve Point scalar multiplication Frobenius equation q-ary method φ-polynomial
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TWO FAST ALGORITHMS FOR COMPUTING POINT SCALAR MULTIPLICATIONS ON ELLIPTIC CURVES 被引量:1
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作者 YouLin WenQiaoyan XuMaozhi 《Journal of Electronics(China)》 2004年第5期366-375,共10页
The key operation in Elliptic Curve Cryptosystems(ECC) is point scalar multiplication. Making use of Frobenius endomorphism, Muller and Smart proposed two efficient algorithms for point scalar multiplications over eve... The key operation in Elliptic Curve Cryptosystems(ECC) is point scalar multiplication. Making use of Frobenius endomorphism, Muller and Smart proposed two efficient algorithms for point scalar multiplications over even or odd finite fields respectively. This paper reduces the corresponding multiplier by modulo Υk-1 +…+Υ+ 1 and improves the above algorithms. Implementation of our Algorithm 1 in Maple for a given elliptic curve shows that it is at least as twice fast as binary method. By setting up a precomputation table, Algorithm 2, an improved version of Algorithm 1, is proposed. Since the time for the precomputation table can be considered free, Algorithm 2 is about (3/2) log2 q - 1 times faster than binary method for an elliptic curve over 展开更多
关键词 Frobenius endomorphism Frobenius expansion Point scalar multiplication Binary method
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Mathieu Progressive Waves
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作者 Andrei B.Utkin 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第10期733-739,共7页
A new family of exact solutions to the wave equation representing relatively undistorted progressive waves is constructed using separation of variables in the elliptic cylindrical coordinates and one of the Bateman tr... A new family of exact solutions to the wave equation representing relatively undistorted progressive waves is constructed using separation of variables in the elliptic cylindrical coordinates and one of the Bateman transforms. The general form of this Bateman transform in an orthogonal eurvilinear cylindrical coordinate system is discussed and a specific problem of physical feasibility of the obtained solutions, connected with their dependence on the cyclic coordinate, is addressed. The limiting case of zero eccentricity, in which the elliptic cylindrical coordinates turn into their circular cylindrical counterparts, is shown to correspond to the focused wave modes of the Bessel-Gauss type. 展开更多
关键词 wave equation Bateman transform progressive wave Mathieu function
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