巧用割补法进行转化

割补法应当说是学生比较熟悉的一种方法．因为在小学推导平行四边形的面积公式、三角形的面积公式等，就是采用的割补法．割补法包含“割”、和“补”两个方面．所谓“割”，就是把一个复杂面积或体积的计算，分割成若干个简单图形的有关计算；所谓“补”，就是将一个不易求出面积或体积的几何图形，补足为较易计算的几何图形，     

非主割边与次连通性在寻求欧拉路中的应用

本文运用图论中无向图的割边及连通性的理论，阐述无向图的主割边与次连通的概念，推导出若干有关性质，并给出一种在无向图中寻求一条欧拉路的有效方法─—取非主割边法。     

村落仪式的逻辑与意义——以石上村客家元宵“割鸡担灯”为分析对象

江西宁都石上村客家"割鸡担灯"仪式的单一性和纯正性,使之并不适用阿诺尔德·范热内普"过渡礼仪"的分析范式。"鸡"和"灯"两个主要意象共同指向生育男孩的自豪与自信。整个仪式过程是男性意识的张扬和抒发,"男丁——家族"的叙述结构模式展示了村落、家族和个体高度一致的生活意义和理想状况。"割鸡担灯"仪式年复一年的展示,成为理解石上村客家生存愿望和精神依托的最有效的程式化叙事。     

多状态流约束通讯网络可靠度计算的一个组合割算法

给出了计算多状态流约束通讯网络可靠度一个有效算法,这个算法从割集出发,找出每个极小割中的有效割组,求出网络的不可靠度,进而求出网络的可靠度.     

割补法的应用

割补法是初中几何中的一种常用解题方法，特别是在有关求面积的问题中，如对图形进行合理的分割或补形，题目就可容易求解。     

多状态流约束通讯网络可靠度的计算

通过依次组合每个极小割的有效子割生成所有的有效组 ,利用生成树实现了多状态流约束网络可靠度的一个新算法 .     

限定顶点个数为p的最大割问题的一种近似算法

给出了求解限定顶点个数为P的最大割问题的一种近似算法,讨论了它的性能保证,利用Pipage技术,为最大割问题设计出了0．5-近似算法．     

基于模糊PID算法的玉米收获机割台高度自动控制系统的设计与试验

目的:为提高玉米收获机的作业效率,降低其劳动强度,解决割台高度调节实时性和准确度差的问题,提出一种基于模糊PID算法的割台高度控制策略.方法:对割台留茬高度控制原理进行优化,将高效的PID算法和模糊控制相结合,运用模糊推理方法实现对割台高度调控参数的在线自整定.在sim ulink环境下对模糊PID控制和传统PID控制进行仿真对比分析,并对控制系统进行现场试验运行测试.结果:割台高度控制误差小于1.5cm,系统响应速度约为0.22m/s,割台调控时间较现有玉米收获机提升约10％.结论:该系统不仅实现了割台高度的实时调控和优化,而且相比传统的控制系统,具有更稳定的动态响应、鲁棒性和精确度,完全满足玉米收获机田间作业的设计要求.     

秋季不同刈割时期对柱花草根系贮藏养分动态的影响

通过分析秋季不同刈割时期对奎安柱花草１８４品系根系贮藏养分动态的影响，对柱花草冬前刈割的临界危险期进行了初步的探讨．根据柱花草根系积累养分的开始期以及根系粗蛋白质和淀粉含量动态对９月１０日和１０月１０日刈割处理的反应，柱花草在试验年度的冬前刈割的临界危险期为９月初～１０月底     

关于曲面切平面的一些讨论

该文给出了曲面切平面的定义并证明了曲面的切平面存在的充要条件,指出了在函数可微的情况下割平面的极限位置、曲面上所有曲线的切线所在的平面都是切平面,同时提出了若要把割平面的极限位置、曲面上所有曲线的切线所在的平面都作为切平面的等价定义有待证明探讨的问题.     

BMP图形文件的特征线识别

在三维物体视频扫描系统中,需要对扫描到的图片逐一进行处理,由于系统是利用物体的明暗暴光来识别扫描的,所以对特征线的识别是系统工作的一个必备步骤．BMP图形文件的特征线识别主要实现以下几个方面的功能：图形增强、图形特征线的细化、图形特征线的连贯、图形特征线的奇异点的处理以及图形特征线的滤波．     

对称性在积分中的应用

给出了奇偶函数的一般性定义。讨论了利用奇偶性求解定积分、重积分、线积分、面积分等积分     

C2连续奇异混合插值曲面

利用奇异混合函数将双三次B样条曲面与虚拟曲面片作混合,构造一类可插值给定数据点的插值曲面,该类曲面在边界处可达到C~2连续,参数α可对曲面片整体形状进行调控。进一步,构造了可局部调控形状的带形状参数的插值曲面。     

Traversing the singularity hypersurface by applying the input disturbances to 6-SPS parallel manipulator

The singular points of a 6-SPS Stewart platform are distributed on the multi-dimensional singularity hypersurface in the task-space, which divides the workspace of the manipulator into several singularity-free regions. Because of the motion un- certainty at singular points, while the manipulator traverses this kind of hypersurface from one singularity-free region to another, its motion cannot be predetermined. In this paper, a detailed approach for the manipulator to traverse the singularity hypersurface with its non-persistent configuration is presented. First, the singular point transfer disturbance and the pose disturbance, which make the perturbed singular point transfer horizontally and vertically, respectively, are constructed. Through applying these disturbances into the input parameters within the maximum loss control domain, the perturbed persistent configuration is transformed into its corresponding non-persistent one. Under the action of the disturbances, the manipulator can traverse the singularity hypersurface from one singularity-flee region to another with a desired configuration.     

一类新的直纹面(英文)

为建筑设计和雕塑构造一类具有优美形状的新型直纹面是有趣的.被构造的这一类新型直纹面是由通过两个互相垂直圆上经过两个动点的直线而生成.它包含类似莫比乌斯带和正劈锥面的特殊案例.此外还分别确定了它们自交线的轨迹.     

Improved response surface method for anti-slide reliability analysis of gravity dam based on weighted regression

The aim of this study was to design and construct an improved response surface method （RSM） based on weighted regression for the anti-slide reliability analysis of concrete gravity dam. The limitation and lacuna of the traditional RSM were briefly analyzed. Firstly, based on small experimental points, research was devoted to an improved RSM with singular value decomposition techniques. Then, the method was used on the basis of weighted regression and deviation coefficient correction to reduce iteration times and experimental points and improve the calculation method of checking point. Finally, a test example was given to verify this method. Compared with other conventional algorithms, this method has some strong advantages： this algorithm not only saves the arithmetic operations but also greatly enhances the calculation efficiency and the storage efficiency.     

一类多分子反应模型的全局结构相图

对一类多分子反应系统进行了完备的全局分析.首先通过寻找该系统的分界线的存在,判定了该系统的闭轨的不存在性.其次,讨论了系统其中的一个奇点只可能是结点.证明了轨道在一象限的走向与p,q的取值无关.最终,通过对有限远奇点,无限远奇点,分界线和闭轨不存在性这四部分的讨论,给出了这类系统的全局结构相图.     

平面多点共线的一个判定方法

给出平面直角坐标系下多点共线的一个判定方法。     

Subdivision processes in mathematics and science

In the course of a research project now in progress, three successive division problems were presented to students in Grades 7–12. The first problem concerned a geometrical line segment, while the other two dealt with material substances (copper wire and water). All three problems involved the same process: successive division. Two of the problems (line segment and copper wire) were also figurally similar. Our data indicate that the similarity in the process had a profound effect on students' responses. The effect of the similarity in process suggests that the repeated process of division has a coercive effect, imposing itself on students' responses and encouraging then to view successive division processes as finite or infinite regardless of the content of the problem. It is possible to trace out, step by step, a more or less parallel process of development for the ideas of points and continuity and those dealing with atoms and physical objects in the child's conception of the ideal world. The only difference between these two processes is that to the child's way of thinking physical points or atoms still possess surface and volume, whereas mathematical points tend to lose all extension (though during the stages of development which concerns us here, this remains only a tendency.) (Piaget & Inhelder, 1948, pp. 126). Our first naive impression of nature and matter is that of continuity. Be it a piece of matter or a volume of liquid we invariably conceive it as divisible into infinity, and even so small a part of it appears to us to possess the same properties as the whole. (Hilbert, 1925, pp. 162).     

Line clipping against polygonal window algorithm based on the multiple virtual boxes rejecting

This paper presents a new algorithm for line clipping against a polygonal window by exploiting the local relationship between each line segment and the polygon. Firstly, a minimal enclosing box (MEB) of the polygon is adopted to reject the invisible line segments located outside the MEB. Secondly, a 45° rotated box is used to encode the endpoint of the line segment, and then reject a portion of the invisible segments crossing polygon corners. Finally, instead of encoding the endpoints of all line segments with respect to the polygonal window, each vertex of the polygon is encoded, taking the line segment to be clipped as reference. For efficient encoding of the polygon vertices, a new concept, termed with slope adaptive virtual box, is introduced regarding each line segment. Such a box can not only conveniently reject all totally invisible lines lying outside the MEB conveniently, but also precisely identify the edges of the polygon with which the line segment potentially intersects. With the summation of the vertex codes, it can be verified whether the line segment is separated from or potentially intersects the polygon window. Based on the product of the codes of adjacent vertices, singular cases of intersection can be solved accurately. Experimental results demonstrate the efficiency and stability of the new algorithm.