Intermediate wheatgrass (Thinopyrum intermedium) (IWG) is a perennial grass being domesticated for grain production with potential to provide economic return and ecosystem services across broad geographic range in North America, yet optimum seeding dates biomass yield are unknown. Our objective was determine the effect of late-summer, fall, spring on grain-type IWG population. Trials were condu...

We present a novel model for due date quotation. Jobs arrive at a single server over time. Upon arrival, the processing time of each job is known, and due dates must be quoted for each job. The jobs must be sequenced on the server so that all jobs complete processing at or before their due dates, and the sum of quoted due dates is minimized. We develop several variations of an on-line heuristic...

We consider the single-machine problem of scheduling n jobs to minimize the total weighted deviation from a given common due date, where the weights for early and tardy completion are asymmetric. First, we assume that the common due date is large. We formulate this problem as an integer linear program with an exponential number of variables and present a column generation algorithm to solve e c...

Project expediting is often viewed as a corrective action taken in response to prior scheduling errors and is usually applied in the later stages of projects when it appears that predefined due dates will not be met. However, large-scale projects with uncertain activity durations tend to have numerous probabilistic network paths with complex interactions that require some level of expediting to...

In this paper we study the problem of scheduling n deteriorating jobs on m identical parallel machines. Each job’s processing time is a nondecreasing function of its start time. The problem is to determine an optimal combination of the due-date and schedule so as to minimize the sum of the due-date, earliness and tardiness penalties. We show that this problem is NP-hard, and we present a heuris...

WC consider the nonprccmptivc single machine scheduling problem with multiple due-dates (delivery dates). where the time between two consecutive due-dates is a constant. Given a set of jobs, we are interested in scheduling the jobs such that the sum of the total due-date cost and the total earliness cost is minimized with the constraint that each job must be finished at or before its due-date. ...