79 resultados para LEAST-SQUARE METHOD
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
Singular value decomposition - least squares (SVDLS), a new method for processing the multiple spectra with multiple wavelengths and multiple components in thin layer spectroelectrochemistry has been developed. The CD spectra of three components, norepinephrine reduced form of norepinephrinechrome and norepinephrinequinone, and their fraction distributions with applied potential were obtained in three redox processes of norepinephrine from 30 experimental CD spectra, which well explains electrochemical mechanism of norepinephrine as well as the changes in the CD spectrum during the electrochemical processes.
Resumo:
提出一种步进扫描投影光刻机承片台不平度检测新技术。在晶圆与承片台存在不同偏移量时,利用线性差分传感器在线测量晶圆上不同点的局部高度;通过建立临时边界条件,以递推法消除晶圆面形影响,并逐行计算出承片台的相对不平度;通过逐行计算的结果递推相邻行之间的高度差,并将该高度差叠加到每一行,以消除临时边界条件的限制,得到处于同一高度上的承片台不平度;将计算的结果作为初始值,根据最小二乘原理,以邻近的四个测量点作为参考,逐步逼近得到承片台的真实不平度。计算机仿真结果验证了该检测方法的正确性,计算结果逐步收敛并逼近真实值
Resumo:
提出一种新的步进扫描投影光刻机工件台方镜不平度测量方法。以方镜平移补偿量与旋转补偿量为测量目标,使用两个双频激光干涉仪分别测量工件台在x和y方向的位置和旋转量;将方镜不平度的测量按照一定的偏移量分成若干个序列,每一个序列包括对方镜有效区域的若干次往返测量;根据所有序列的测量结果计算出方镜的旋转补偿量;为每一个序列建立临时边界条件,并据此计算出每一序列所测得的方镜粗略平移补偿量;采用三次样条插值与最小二乘法建立每一个序列间的关系,以平滑连接所有测量序列得到精确的方镜平移补偿量。结果表明,该方法用于测量方镜平
Resumo:
BR-D96N is a kind of genetically site-specific mutants of bacteriorhodopsin (BR) with obvious photochromic effect. Compared to the wild type BR, the lifetime of M state of BR-D96N is prolonged to several minutes so that the photochromic kinetics and the intermediates formation can be studied by the conventional spectra analysis. In the experiment, the absorption spectra of the sample at different time after light illumination are measured with spectrophotometer. By fitting and analyzing the variation of the spectra, we suppose that there are three main states in the, photochromic process, i.e., B state (light-adapted state), M state and D state (dark-adapted state). The absorption spectra of the B state, M state and D state are extracted from the experimental data based on this three-state model and the spectra at various time are fitted with the least-square method. So, the variations of population percentages of the M state, B state and D state are obtained and the M state and B state lifetimes are estimated. In another way, from the measurement of the absorption dynamics at 407 and 568 nm, the M state and B state lifetimes are also obtained by two exponential data fitting, which give coincident results with those of the spectra analysis. (C) 2003 Elsevier Science B.V. All rights reserved.
Resumo:
BR-D96N is a kind of genetically site-specific mutant of bacteriorhodopsin (BR) with obvious photochromic effect. Compared to the wild type BR, the lifetime of M state of BR-D96N is prolonged to several minutes so that the photochromic kinetics and the intermediates formation can be studied by the conventional spectra analysis. In the experiment, the absorption spectra of the sample at different time after light illumination are measured with spectrophotometer. By fitting and analyzing the variation of the spectra, we suppose there-are three main states in the photochromic process, i.e. B state (light-adapted state), M state and D state (dark-adapted state). The absorption spectra of the B state, M state and D state are extracted from the experimental data based on this three-state model and the spectra at various time are fitted With the least square method. So, the variations of population percentages of the M state, B state and D state are obtained and the M state and B state lifetimes are estimated. In another,way, from measuring the absorption dynamics at 407 nm and 568 nm, the M state and B state lifetimes are also obtained by two exponential data fitting, which give coincident results with those of the spectra analysis.
Resumo:
The neutron deficient nuclide Ir-175 was produced by irradiation of Nd-146 with 210 MeV Cl-35 via a fusion-evaporation reaction channel. The reaction products were transported to a low-background location using a helium-jet recoil fast-moving tape-transport system for measurement. The experimental devices and data analysis method are introduced. Based on the decay-curve fitting of the beta-delayed gamma ray from Ir-175, realized by the least-square method, a new long-lived isomeric state of Ir-175 is proposed and briefly discussed.
Resumo:
研发了基于眼固定安装方式的机器人定位系统,提出了一种方便有效的手眼标定方法。通过最小二乘法求解手眼坐标的变换关系,再根据工作台平面与摄像机成像模型的约束关系,求解出目标物体的三维位姿,并最终实现了机械手的精确定位。
Resumo:
应用于融动化生产线基于眼固定安装方式的机器人定位系统,提出了一种方便有效的手眼标方法。通过最小二乘法求解手眼坐标的变换关系,再根据工作台平面与摄像机成像模型的约束关系,求解出目标物体的三维位姿,并最终实现丁机械手的精确定位。
Resumo:
作为可再生能源,波浪能的吸收和利用一直是国内外热点研究内容之一。本文提出一种新的基于惯性摆结构的波浪能吸收转换方法,对这种结构在波浪力作用下的频域响应进行了分析,建立了其最优化能量获取模型,提出采用多种群遗传算法对其结构进行优化设计,并针对系统所受波浪力(矩)随载体半径改变而改变,且求取困难的问题,采用最小二乘法对波浪力(矩)与载体半径变化的关系进行了拟和。通过优化结果找出影响结构获取波浪能量的因素,仿真结果表明了方法的先进性,为进一步的应用研究和频域波能获取研究奠定了基础。
Resumo:
要测量出一组特征点分别在两个空间坐标系下的坐标 ,就可以求解两个空间目标间的位姿关系 .实现上述目标位姿测量方法的前提条件是要保证该组特征点在不同坐标系下 ,其位置关系相同 ,但计算误差的存在却破坏了这种固定的位置关系 .为此 ,提出了两种基于模型的三维视觉方法——基于模型的单目视觉和基于模型的双目视觉 ,前者从视觉计算的物理意义入手 ,通过简单的约束迭代求解实现模型约束 ;后者则将简单的约束最小二乘法和基于模型的单目视觉方法融合在一起来实现模型约束 .引入模型约束后 ,单目视觉方法可以达到很高的测量精度 .而基于模型的双目视觉较传统的无模型立体视觉方法位移精度提高有限 ,但姿态精度提高很多
Resumo:
本文主要研究完全未知结构化环境下的移动机器人二维几何地图构建及其不确定性描述问题。在考虑测量噪声干扰的基础上,基于改进的角度直方图算法进行环境线段特征提取和参数初始估计,然后利用加权最小二乘法对线段特征参数及其方差进行精确估计,并同时给出了多位姿地图合并的处理方法.文章最后给出了在SmartROB2机器人平台上进行的实验结果,证明了算法的有效性和实用性。
Resumo:
描述了水下滑翔机器人3个运动调节机构的设计,即浮力调节机构、俯仰调节机构和横滚调节机构,分析了运动调节机构与运动之间的关系.提出了采用CFX水动力计算软件分析水下滑翔机器人运动性能的方法.根据CFX计算结果,用最小二乘法参数辨识方法辨识出定常滑翔运动的水动力参数.简化了空间螺旋回转运动过程,通过CFX水动力计算方法进行回转特性分析,估算回转半径.
Resumo:
As a fast and effective method for approximate calculation of seismic numerical simulation, ray tracing method, which has important theory and practical application value, in terms of seismic theory and seismic simulation, inversion, migration, imaging, simplified from seismic theory according to geometric seismic, means that the main energy of seismic wave field propagates along ray paths in condition of high-frequency asymptotic approximation. Calculation of ray paths and traveltimes is one of key steps in seismic simulation, inversion, migration, and imaging. Integrated triangular grids layout on wavefront with wavefront reconstruction ray tracing method, the thesis puts forward wavefront reconstruction ray tracing method based on triangular grids layout on wavefront, achieves accurate and fast calculation of ray paths and traveltimes. This method has stable and reasonable ray distribution, and overcomes problems caused by shadows in conventional ray tracing methods. The application of triangular grids layout on wavefront, keeps all the triangular grids stable, and makes the division of grids and interpolation of a new ray convenient. This technology reduces grids and memory, and then improves calculation efficiency. It enhances calculation accuracy by accurate and effective description and division on wavefront. Ray tracing traveltime table, which shares the character of 2-D or 3-D scatter data, has great amount of data points in process of seismic simulation, inversion, migration, and imaging. Therefore the traveltime table file will be frequently read, and the calculation efficiency is very low. Due to these reasons, reasonable traveltime table compression will be very necessary. This thesis proposes surface fitting and scattered data compression with B-spline function method, applies to 2-D and 3-D traveltime table compression. In order to compress 2-D (3-D) traveltime table, first we need construct a smallest rectangular (cuboidal) region with regular grids to cover all the traveltime data points, through the coordinate range of them in 2-D surface (3-D space). Then the value of finite regular grids, which are stored in memory, can be calculated using least square method. The traveltime table can be decompressed when necessary, according to liner interpolation method of 2-D (3-D) B-spline function. In the above calculation, the coefficient matrix is stored using sparse method and the liner system equations are solved using LU decomposition based on the multi-frontal method according to the sparse character of the least square method matrix. This method is practiced successfully in several models, and the cubic B-spline function can be the best basal function for surface fitting. It make the construction surface smooth, has stable and effective compression with high approximate accuracy using regular grids. In this way, through constructing reasonable regular grids to insure the calculation efficiency and accuracy of compression and surface fitting, we achieved the aim of traveltime table compression. This greatly improves calculation efficiency in process of seismic simulation, inversion, migration, and imaging.
Resumo:
At first, the article has an introduction of the basic theory of magnetotelluric and the essential methods of data acquisition and preprocessing. After that, the article introduces the methods together with their predominance of computing transfering function such as the Least-square method, the Remote-Reference method and the Robust method. The article also describe the cause and influence of static shift, and has a summarize of how to correct the static shift efficiently, then emphasizes on the theories of the popular impedance tensor decomposition methods as Phase-sensitivity method, Groom and Bailey method, General tensor-analyzed method and Mohr circle-analyzed method. The kernal step of magnetotelluric data-processing is inversion, which is also an important content of the article. Firstly, the article introduces the basic theories of both the popular one-dimensional inversion methods as Automod, Occam, Rhoplus, Bostick and Ipi2win and the two-dimensional inversion methods as Occam, Rebocc, Abie and Nlcg. Then, the article is focused on parallel-analysis of the applying advantage of each inversion method with practical models, and obtains meaningful conclusion. Visual program design of magnetotelluric data-processing is another kernal part of the article. The bypast visual program design of magnetotelluric data-processing is not satisfied and systemic, for example, the data-processing method is single, the data-management is not systemic, the data format is not uniform. The article bases the visual program design of magnetotelluric data-processing upon practicability, structurality, variety and extensibility, and adopts database technology and mixed language program design method; finally, a magnetotelluric data management and processing system that integrates database saving and fetching system, data-processing system and graphical displaying system. Finally, the article comes onto the magnetotelluric application.takeing the Tulargen Cu-Ni mining area in Xingjiang as the practical example, using the data-processing methods introduced before, the article has a detailed introduction of magnetotelluric data interpretation procedure.
Resumo:
A novel method to construct a quality map, called modulation-phase-gradient variance (MPGV), is proposed, based on modulation and the phase gradient. The MPGV map is successfully applied to two phase-unwrapping algorithms - the improved weighted least square and the quality-guided unwrapping algorithm. Both simulated and experimental data testify to the validity of our proposed quality map. Moreover, the unwrapped-phase results show that the new quality map can have higher reliability than the conventional phase-derivative variance quality map in helping to unwrap noisy, low-modulation, and/or discontinuous phase maps. (c) 2006 Society of Photo-Optical Instrumentation Engineers.