Bezier曲线在轮廓字中的应用

从Bezier曲线的数学表达式、二次三次Bezier曲线的矩阵表示、Bezier曲线的性质等出发，组合SPDOS曲线字库内部结构和TURBOC语言程序，来具体说明Bezier曲线在轮廓字中的应用。     

基于视觉信息的四轴飞行器位姿估计研究

提出一种基于已知特征点的单目视觉位姿估计方法。根据摄像机透视投影成像关系,建立四轴飞行器视觉位姿估计模型,设计一种着陆目标图案,提出着陆目标图案特征点提取及标记方法。实验结果表明,该位姿估计算法是有效的。     

基于深度学习的工业机器人位姿误差自动补偿方法

为提高工业机器人在运行过程中的位姿精度,引入深度学习,开展对其位姿误差自动补偿方法的设计研究。结合深度学习,建立机器人位姿目标识别定位模型,并在RPN网络中完成模型的迭代和学习;为实现对工业机器人位姿误差的自动补偿控制,导入误差自动补偿模糊控制器;最后将位姿误差及补偿结果输出,实现对工业机器人位姿误差的补偿。通过对比实验的方式证明,新的补偿方法可以有效提高工业机器人运行时的位姿精度,进而促进工业机器人运行质量的提升。     

一类类Bezier曲线及其扩展

该文研究一类类Bezier曲线及其扩展。主要根据一组三角基函数构造由四个控制顶点组成的类Bezier曲线,随后引入基函数中的形状控制参数得到带形状参数的类Bezier曲线,进而构造了带形状参数的类Bezier插值曲线,这是基于通过混合函数混合参数化的控制多边形及类Bezier曲线得到的一类曲线。它具有局部性、端点性质、几何不变性与仿射不变性、对称性、凸包性、变差缩减性等性质。同时它可以表示Bezier曲线所不能表示的圆锥曲线,最重要的性质是其具有插值性,这样就大大增强了其在实际领域中得到应用的可能性。     

一类类Bézier曲线及其扩展

该文研究一类类Bezier曲线及其扩展。主要根据一组三角基函数构造由四个控制顶点组成的类Bezier曲线,随后引入基函数中的形状控制参数得到带形状参数的类Bezier曲线,进而构造了带形状参数的类Bezier插值曲线,这是基于通过混合函数混合参数化的控制多边形及类Bezier曲线得到的一类曲线。它具有局部性、端点性质、几何不变性与仿射不变性、对称性、凸包性、变差缩减性等性质。同时它可以表示Bezier曲线所不能表示的圆锥曲线,最重要的性质是其具有插值性,这样就大大增强了其在实际领域中得到应用的可能性。     

一种切削位姿动态优化全局刀路技术的五轴曲面插补方法设计及验证

针对五轴加工反向运动学映射机制下,给定刀路轨迹驱动各轴的位移量会随工件切削位姿的不同而存在差异,进而影响进给速度曲线各轴分量的光滑性问题,提出了五轴曲面在线插补实验方法。将工件实际切削位姿综合信息应用于设计前端环节,关注于刀路形貌和切削位姿作用于进给速度曲线的非线性影响,以复杂曲面加工的综合最优效率为目标,开展由切削位姿逆向驱动刀路纹理规划的曲面直接插补方法设计。结果表明,切削位姿反向优化于插补刀路技术作用下的工件表面质量更优于传统五轴曲面加工工件,实现了数控五轴曲面的高速高质量的加工。     

有理Bezier曲面模型的构建与应用

传统的建模方法不能精确表示曲面体的弯曲度,针对这些不足,本文采用有理Bezier方法构建曲面模型,给出了椭球体标准型有理二次Bezier控制点和权因子的求解算法;利用非有理Bezier的升阶算法将有理二次Bezier升阶为有理三次Bezier,给出了标准型有理三次Bezier曲线控制点和权因子的求解算法,构建了有理双三次Bezier椭球体曲面模型,通过调整控制点或权因子参数可生成如葫芦、青椒、鸡蛋等光滑的曲面模型.实验表明,该算法具有很好的设计灵活性和交互性,为构建曲面模型提供了新的技术支持.     

Bezier曲线与曲面极值问题的研究

由于Bezier曲线与曲面的特性,它在计算机的辅助几何设计方面得到广泛的应用。本文在分析Bezier曲线与曲面的基础上,提出了Bezier曲线与曲面极值问题,即最短Bezier曲线与最小Bezier曲面问题,并提出了用模式搜索法与在matlab中用变量极值函数来解决该问题的解法,最后通过实例验证了该解法。     

二次Bezier曲线与三次非均匀B样条曲线的拼接

利用B样条曲线的Bezier构造方法,把二次Bezier曲线与三次非均匀B样条曲线的拼接转化为二次Bezier曲线与三次Bezier曲线之间的拼接问题,并分别给出了二次Bezier曲线与三次非均匀B样条曲线的拼接的G0,G1,G2光滑拼接条件．     

线切割CAD/CAM系统开发中的自由曲线造型方法的研究

本文介绍了线切割CAD/CAM系统的自由曲线生成方法.通过比较Bezier曲线、B样条曲线、非均匀有理B样条(NURBS)曲线等主要造型方法,选择了一种适合线切割CAD/CAM系统的简单、易用的几何造型方法,并阐述其算法.     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

Western and Eastern culture differences in commercial field

The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity.     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

风的曲线

Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose.     

团图为数的图中的闭团贯数

Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.