碰撞检测算法研究

针对传统数值方法求解非线性方程组时对初始值敏感与收敛性差等问题,探讨了应用人工鱼群算法求解非线性方程组的方法。将非线性方程组的求解问题转化为函数优化问题,应用人工鱼群算法进行优化求解。使用该方法不需要借助目标函数的初始点信息和导数信息,通过数值实验结果可知该方法具有有效性和可行性。     

求解一类均衡约束优化问题的交替束方法

非光滑均衡问题包括很多优化问题,例如变分不等式问题、互补问题、约束为广义方程的数学规划问题、标准的约束优化问题等等。目前求解均衡问题的算法有邻近点算法、直接搜索法、投影收缩算法、光滑化投影梯度算法等,而交替束方法是一类求解目标函数具有可分离结构的有效算法,可以看成是一类特殊的邻近点法。针对均衡约束数学规划问题中的双层规划问题,首先最为核心的思想是应用参数极小化技术将该约束优化问题转化为一序列的极小化两个凸函数和的无约束单层优化问题;然后构造两个近似的子问题,应用交替束方法交替求解,最后建立算法的收敛性分析。     

求解非线性方程组的智能新方法

求解方程组是工程研究中的基本问题,因此将非线性方程组的求解问题转化为函数优化问题,应用一种新的智能优化算法-布谷鸟搜索算法求解此优化问题,数值实验结果表明了该算法在求解非线性方程组时的可行性和有效性。     

一类无穷边值问题的数值模拟

应用一种非线性变换,将一类无穷边值问题转化为等价带奇异项的Dirichle问题,并利用有限差分方法、Newton迭代法和多重网格方法,对该问题进行了数值模拟,验证了该方法的可行性.     

分数阶微分方程边值问题正解的局部存在与多解性

应用Green函数将分数微分方程边值问题转化为积分方程的方法讨论分数阶微分方程边值问题正解的存在性.研究非线性分数阶微分方程的两点边值问题,主要工具是锥上的Krasnosel'skii不动点定理.结果表明:只要非线性项在某些有界集合上的"高度"是适当的,该问题有n个正解(n是一个任意给定的正整数).     

极大极小值问题修正的SQP算法

提出了一种修正的SQP算法求解带约束的极大极小问题,仅添加一个额外的变量,将带约束的极大极小问题转化为序列二次规划问题。证明了在合理的假设条件下,序列二次规划问题的极小值点就是原问题的极小值点。数值结果表明这种SQP算法是求解带约束有限极大极小问题的一种有效算法。     

一种间接求解约束优化问题的遗传算法

传统的遗传算法在求解带约束的数值优化问题时,主要采用罚函数法。文章针对罚函数法在实际应用中的不足,提出了一种将约束优化问题转化为双目标优化问题,然后使用双目标遗传算法进行求解的方法。仿真结果表明该方法是一种有效的约束问题寻优方法。     

关于非线性方程组HX+VX=0解的球形算法

关于非线性方程组HX+VX＝O的求解;Peaceman—Rachford提出了一种方法,该法对求解的误差估计及收敛速度无法确定,因而在计算机上很难应用此法求解。本文构造一种球形算子,采用球形算法求其解,可克服上述方法之不足,并应用此球形算法可求解两点边值问题。     

具有两个边界层的奇异摄动转向点问题的数值方法

基于再生核理论,提出了求解具有两个边界层的奇异摄动转向点问题的数值方法.首先通过一个合适的变量变换,把原问题转化成不再具有边界层的边值问题,转化后的边值问题通过再生核方法进行求解,数值算例的结果表明该方法是有效的.     

约束优化问题的一种投影梯度Lagrange乘子法

运用Lagrange乘子法,将一般约束优化转化为仅含等式约束的优化问题,然后就线性与非线性两种情况进行讨论,通过投影梯度法来求解优化子问题.对于线性的情况得到一种可以不用计算初始点的最优化算法,最后的数值算例说明了算法的可行性与有效性.     

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,     

汉字倒说

汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。     

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.     

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.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

钱生钱!

我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了     

Inequalities for inscribed simplexes

The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex.     

胡主席在印度,我却在中国

Today, Sunday morning, I sit thinking and typing at my computer. My thoughts are in my homeland, India and my body is in China. The body is here and mind there for a good reason. Mr. Hu is president and I am resident and both are in each other's countries (what a difference the absence of one small letter makes!). Mr. Hu will return in a few days and I will stay on longer.