共查询到19条相似文献，搜索用时 203 毫秒
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采用GPS控制网做施工测量控制网时,和传统测量控制网一样,存在任意高程基准变换（高程投影面补偿）和中央子午线投影变形问题;如何判断和消除投影变形的影响,仍是GPS控制网解算工作的重点。 相似文献
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在矿井日常生产的实际测量工作中，应用直线方程和直线方程组的求解，确定井下巷道位置，满足设计要求，取得较好效果。 相似文献
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张树刚 《内蒙古科技与经济》2003,(4):138-138
导入新课 ,是《机械制图》课堂教学的重要一环 ,是为讲解新内容做的铺垫。在教学的起始阶段 ,如果教师能引入富有魅力的导语 ,以新颖的材料吸引学生 ,就能让学生的注意力迅速集中起来 ,产生学习新内容的强烈要求和愿望 ,从而为教师讲解新内容打好基础。1 检查复习法教师引导学生复习总结那些与新知识有联系的问题 ,从新旧知识的紧密联系中 ,合乎逻辑地提出这节课将要讲解的问题。例如在“直线的投影”一节教学中 ,首先学生一起复习点的投影 ,接着与学生重温两点确定一条直线的几何原理 ,然后启发学生 ;如果想画出直线的投影 ,应该怎么办 ?… 相似文献
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随着我国煤炭产量的逐年递增,煤矿采掘作业面逐步向纵深方向发展,这使得大倾角煤层随之不断增多。由于大倾角作业面本身具有一定的特殊性,需要采取与之相配套的开采工艺。目前,国内的各大煤矿在对大倾角作业面进行开采时,一般采用的都是仰斜综采工艺,该工艺是倾斜长壁采煤法的一种庀具有缓斜煤层倾斜长壁采煤法的一般规律。然而由于开采过程的推进方向与实际走向均与长壁不同,所以必须采取相应的技术措施,确保开采工作顺利进行。基于此点,本文就大倾角仰斜综采工艺的应用进行浅谈。 相似文献
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随着经济的发展,线路工程如高等级公路、油气管线等的建设越来越多。在公路控制测量中,为了满足施工放样中的变形达到测量规范的规定,就需要选择一个合适的投影面和投影带,亦即合理地确立工程平面控制网的坐标系。本文将结合实际探讨几种线路工程测量中的投影长度变形值控制方法,即分带投影法、分区抵偿法、边长约束法。 相似文献
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高职机械类专业的机械制图课程中,点线面的投影是学习后续内容的基础,也是教学的重点和难点之一。本文分析了点、线、面的投影在教学中存在难度的原因,探讨了以长方体为空间点、各种位置直线、各种位置平面的载体,结合举例法、自主探究法、归纳法、逆向思维法等教学方法,多种教学手段,学习这部分内容的方法。 相似文献
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带前馈输入观测——状态反馈控制系统的设计过程,涉及带符号变量的矩阵方程组求解,其通解一般难于求出,国内外大多数文献只能用递推法求其前几个采样值。借助MATLAB符号数学工具箱的有关函数,直接进行带符号变量矩阵运算和方程组求解,得到其准确的通解,系统设计全过程由编制的M文件自动完成。仿真结果表明,提出的设计方法和求解过程是正确的。 相似文献
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In this paper, the Bagley-Torvik equation, which has an important role in fractional calculus, is solved by generalizing the Taylor collocation method. The proposed method has a new algorithm for solving fractional differential equations. This new method has many advantages over variety of numerical approximations for solving fractional differential equations. To assess the effectiveness and preciseness of the method, results are compared with other numerical approaches. Since the Bagley-Torvik equation represents a general form of the fractional problems, its solution can give many ideas about the solution of similar problems in fractional differential equations. 相似文献
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《Journal of The Franklin Institute》2023,360(5):3825-3848
Iterative learning control (ILC) applies to systems that repeat the same finite duration task repeatedly. Each repetition is usually termed as a trial, and the associated duration is called the trial length. Once a trial is completed, all information is available for use in updating the control input for the subsequent trial. The vast majority of the currently available designs demand a strictly identical trial length. This paper gives a new result on the design and analysis for continuous-time linear dynamics based on a modified alternating projection method, where the trial lengths may be nonidentical. This result employs multiple sets to represent the actual varying trial length dynamics and is developed by reformulating the problem to one that minimizes the defined distance in a Hilbert space setting. Compared to the standard alternating projections using two sets, the theory of alternating projections between multiple sets is employed to obtain deterministic convergence result for the nonidentical trial length problem. A numerical case study is also given to illustrate the application of the new design. 相似文献
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利用常数变易法求解具有实特征根的四阶常系数非齐次线性微分方程，在无需求其特解及基本解组的情况下给出其通解公式，并举例验证公式的适用性。 相似文献
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Nonlinear two-point boundary value problems have always been difficult to solve. The difficulty is compounded if the problem tends to be inherently unstable. This paper describes an algorithm for solving such sensitive boundary value problems. The procedure is based on a computational method for finding the general solution of systems of ordinary differential equations used in conjunction with the multi-point quasilinearization method of Miele. The method is demonstrated by solving Troesch's problem and a singular perturbation problem. 相似文献
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公司治理研究所有权与经营权分离情况下的“代理人问题”，其焦点在于使所有者与经营者利益尽可能相一致。在对管理者和股东之间的利益冲突、债权人与股东的利益冲突分析的基础上，提出了代理问题的一般解决方法并指出公司治理研究的未来发展方向。 相似文献
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A numerical method is proposed for solving multi-dimensional hyperbolic–parabolic differential equations with the nonlocal boundary condition in t and Dirichlet and Neumann conditions in space variables. The first and second order of accuracy difference schemes are presented. The stability estimates for the solution and its first and second orders difference derivatives are established. A procedure of modified Gauss elimination method is used for solving these difference schemes in the case of a one-dimensional hyperbolic–parabolic differential equations with variable coefficients in x and two-dimensional hyperbolic–parabolic equation. 相似文献