摘要:

Generally, processing a new order in a job-shop production system affects the schedule of other products. This change of schedule of other products results in some costs such as set-up cost, inventory cost, re-schedule cost. The amount of these costs depends upon the schedule (process starting time) of the new order for processing in a predetermined schedule of multiple products in a job-shop. The application of queuing theory for determining the optimal scheduling of a new order in a job-shop manufacturing system is discussed. The basic criterion considered for the new order scheduling/process starting date is the minimization of total variable cost. The total variable cost consists of the cost elements: (i) raw material waiting cost or unavoidable waiting time for the new order; (ii) inventory carrying cost for the new order due to early completion or penalty cosl due to late completion or delivery; (iii) re-schedule cost due to change in schedule of the other items. An example is given to illustrate the application of the model.

ISSN:0020-7721    

DOI:10.1080/00207729408928965

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

An adaptive first-order W-E generalized analytical predictor (GAP) is presented lo overcome the difficulty that is caused by possible changes in the load transfer function for output disturbances. An on-line adaptive algorithm for updating the parameter in the load transfer function is derived and the convergence of the algorithm is also analysed. This algorithm contains tuning parameters that can be chosen for the purpose of its robust stability. The proposed adaptive W-E GAP is implemented during the second phase of a two-phase adaptive system for predictive control.

ISSN:0020-7721    

DOI:10.1080/00207729408928966

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The optimal control of linear systems with quadratic cost functional is considered. The method is based on shifted Legendre approximation of each state variable that converts the linear quadratic problem to a system of linear algebraic equations. An illustrative example is included to demonstrate the validity and applicability of the technique.

ISSN:0020-7721    

DOI:10.1080/00207729408928967

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Two scheduling problems are considered: (1) scheduling n jobs non-preemptively on a single machine to minimize total weighted earliness and tardiness (WET); (2) scheduling n jobs non-preemptively on two parallel identical processors to minimize weighted mean flow time. In the second problem, a pre-ordering of the jobs is assumed that must be satisfied for any set of jobs scheduled on each specific machine. Both problems are known to be NP-complete. A 0-1 quadratic assignment formulation of the problems is presented. An equivalent 0-1 mixed integer linear programming approach for the problems are considered and a numerical example is given. The formulations presented enable one to use optimal and heuristic available algorithms of 0-1 quadratic assignment for the problems considered here.

ISSN:0020-7721    

DOI:10.1080/00207729408928968

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor