用Excel软件实现最大似然估计数值计算的方法

本文给出用Excel软件实现最大似然估计数值计算求解的方法。内容包括对似然方程求数值解、直接对似然函数或对数似然函数求极大值以及分组数据最大似然估计的数值计算。     

New solution methods for single machine bicriteria scheduling problem: Minimization of average flowtime and number of tardy jobs

We consider the bicriteria scheduling problem of minimizing the number of tardy jobs and average flowtime on a single machine. This problem, which is known to be NP-hard, is important in practice, as the former criterion conveys the customer’s position, and the latter reflects the manufacturer’s perspective in the supply chain. We propose four new heuristics to solve this multiobjective scheduling problem. Two of these heuristics are constructive algorithms based on beam search methodology. The other two are metaheuristic approaches using a genetic algorithm and tabu-search. Our computational experiments indicate that the proposed beam search heuristics find efficient schedules optimally in most cases and perform better than the existing heuristics in the literature.     

Sum Multicoloring of Graphs

Scheduling dependent jobs on multiple machines is modeled by the graph multicoloring problem. In this paper we consider the problem of minimizing the average completion time of all jobs. This is formalized as the sum multicoloring problem: Given a graph and the number of colors required by each vertex, find a multicoloring which minimizes the sum of the largest colors assigned to the vertices. It reduces to the known sum coloring problem when each vertex requires exactly one color.This paper reports a comprehensive study of the sum multicoloring problem, treating three models: with and without preemptions, as well as co-scheduling where jobs cannot start while others are running. We establish a linear relation between the approximability of the maximum independent set problem and the approximability of the sum multicoloring problem in all three models, via a link to the sum coloring problem. Thus, for classes of graphs for which the independent set problem is ρ-approximable, we obtain O(ρ)-approximations for preemptive and co-scheduling sum multicoloring and O(ρ log n)-approximation for nonpreemptive sum multicoloring. In addition, we give constant ratio approximations for a number of fundamental classes of graphs, including bipartite, line, bounded degree, and planar graphs.     

关于高校图书馆典藏岗位设置的思考

本文探讨了传统典藏管理岗位设置的不合理性、新典藏管理方式与传统典藏管理方式相比较显示出的优越性及应注意的问题。     

平行机器的分批排序问题

本文研究一类具有分批约束的平行机排序问题.在恒同机情形导出Greedy算法,在m=2情形建立了匹配算法,在两台一致机器情形讨论了2-交换算法,并得到若干计算复杂性结果。     

高校图书馆勤工助学岗位培养与考核体系构建——以山东大学图书馆阅览部为例

在深入分析高校勤工助学岗位培养和考核工作存在问题基础上,探讨了勤工助学岗位培养与考核体系应遵循的原则,立足于山东大学图书馆管理工作的实际,以《山东大学勤工助学管理办法》为依据,全面细化了勤工助学岗位培养与考核办法,重新构建了勤工助学岗位培养和考核体系。     

众数计算的进一步讨论

在众数计算应该具备的两个假设和两个性质的条件下,常用的众数计算公式得到的结果只考虑了众数组及其前后两组,因此具有一定的局限性。一种考虑全部组频次的众数计算公式可以得到考虑更为全面的结果,并且这种计算公式也具有原公式所具有的一切良好属性。结合实例可以发现改进后的众数计算公式可以得到更佳的结果。