Guo-zhong Bai’s research while affiliated with Guangdong University of Foreign Studies and other places

The k-cardinality assignment problem is a generalization of the assignment problem in which a cost matrix and a positive integer k are given and one wants to assign k rows to k columns so that the sum of the corresponding costs is a minimum. M. Dell' Amico and S. Martello are the first who considered the k-cardinality assignment problem (1997). In 2001, M. Dell' Amico, A. Lodi and S. Martello considered further specialized efficient algorithm. The object of this paper is to show the k-cardinality assignment problem is solvable by transforming it into a classical assignment problem, and obtain a new algorithm.

This paper establishes a new assignment problem called the time limit assignment problem (TLAP) which pursues the best overall efficiency only if all tasks have been completed in time or very close to the deadline. The time limit assignment problem contains one discrete goal constraint, and therefore it is a special goal programming problem. This paper provides a mathematical model for such a time limit assignment problem and introduces a method to find its optimal solutions and the deviation of the optimal solution to the warning time. We also provide an example that illustrates how to solve the time limit assignment problem.

This paper introduces a new assignment problem called the Grey Assignment Problem, in which the cost of assigning every worker to every job is a grey number rather than a real number. We establish the mathematical model of the grey assignment problems and concerned theory, and also give some methods for solving the grey assignment problems.