JIT方式下的单机分批调度问题的一种算法

在现代生产管理中,合理安排工件的加工顺序使所有的工件准时完工极为重要．文中研究工件不允许拖期的单机分批调度问题,目标是使加工．总成本最小,目标函数不仅考虑了工件提前完工有提前惩罚成本,还考虑了批加工成本费用．提出了一种多项式时间的最优算法．     

加工时间依赖工件位置的树约束单机排序问题

讨论了工件的加工时间依赖于工件位置的树约束单机排序问题,给出了目标函数为最大完工时间的多项式算法.结果表明,最大家庭树中的工件优先于其它家庭树中的工件加工,并且其工件要连续加工所得到的排序为最优排序.     

“合成链”算法与一类链优先约束的单机分批排序问题

讨论问题1| chains,B|Cmax具体可描述为:有m条链,其中一条链上有n个工件,其余的m-1条链上的工件数之和为常数k,且工件的加工时间不限制,目标函数为最大完工时间.我们对该问题B=2的情况进行了深入的探讨,在研究过程中首次提出“合成链“算法,给出了时间复杂性为O(nk)的多项式时间算法.     

工件带拒绝费用的单机排序问题

在经典排序模型中,我们往往假定机器必须加工所有的工件,并且它们的加工时间都是给定的。但是在许多现实的应用中,若某个工件的加工时间或者加工费用很大,我们就会考虑是否要加工该工件,我们既可以选择付出一定的费用而拒绝加工该工件也可以选择不付费而加工它。这时目标函数不再是传统的最大总完工时间,极小化最大完工时间,最大延迟等,而是要同时考虑费用,我们把这种排序称为可拒绝排序[1][2]。本文研究了工件带拒绝费用的单机分族分批排序问题。主要证明了问题1,sfg|family-jobs,rej|Cmax+∑j∈sej和1,sfg|family-jobs,rej,b|Cmax+jisej是NP-难的,给出了它们的近似算法。     

工件具有学习效应的分批排序问题

讨论了分批排序中工件具有学习效应、目标函数为极小化加权总完工时间的几个问题,分别就所有工件的基本加工时间都相等的情况给出了几种算法,并证明了算法的最优性.     

一类带批安装时间的平行机在线分批排序问题

研究一类带批安装时间的平行机排序问题。工件按时间到达,在任何时刻,只知道当前已经就绪工件的信息。工件成批加工,同一批中工件的完工时间为批中最后一个工件的完工时间,每批开工前有一个固定的批安装时间。目标函数为极小化所有工件的总完工时间。主要考虑两个到达时间且工件加工时间都相等的特殊情形,给出竞争比为3/2的在线算法,并且有实例说明此界为紧致的。     

工件有优先约束和尺寸的单机分批排序问题

研究了工件有优先约束和尺寸大小关系的分批排序问题,这里目标函数为工件的极大完工时间,这类问题是NP—完备的.对工件加工时间相同和有特殊到达时间的情况给出了它的近似算法,并证明其最差性能比不超过2.     

带学习效应的单机成组排序问题

考虑了在工件具有学习效应的条件下,目标函数为最大完工时间和总完工时间的单机成组排序问题.对这两个问题分别给出了多项式时问算法并证明了其算法的最优性.     

一类超前有奖延误受罚的排序问题

讨论了带有学习效应的排序问题,目标函数为超前有奖延误受罚的几个问题.对所有工件加工时间不相同和相同的情形,分别给出了算法,并证明了算法的最优性.     

关于机器排序虚图问题

1 问题的提出及模型设有 N 个工件要在 M 台机器上加工,按工艺技术的要求或规定,某个工件必须在特定的机器上加工,每个工件在某个机器上加工所需时间是一定的,每个工件由于规格要求不同,它在各台机器上加工的顺序也不同,并且也可能仅在 M 台机器中的一部分机器上     

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.