3854 research outputs found
Sort by
Queuing-Inventory Models with MAP Demands and Random Replenishment Opportunities
Get PDFCombining the study of queuing with inventory is very common and such systems are referred to as queuing-inventory systems in the literature. These systems occur naturally in practice and have been studied extensively in the literature. The inventory systems considered in the literature generally include (s, S)-type. However, in this paper we look at opportunistic-type inventory replenishment in which there is an independent point process that is used to model events that are called opportunistic for replenishing inventory. When an opportunity (to replenish) occurs, a probabilistic rule that depends on the inventory level is used to determine whether to avail it or not. Assuming that the customers arrive according to a Markovian arrival process, the demands for inventory occur in batches of varying size, the demands require random service times that are modeled using a continuous-time phase-type distribution, and the point process for the opportunistic replenishment is a Poisson process, we apply matrix-analytic methods to study two of such models. In one of the models, the customers are lost when at arrivals there is no inventory and in the other model, the customers can enter into the system even if the inventory is zero but the server has to be busy at that moment. However, the customers are lost at arrivals when the server is idle with zero inventory or at service completion epochs that leave the inventory to be zero. Illustrative numerical examples are presented, and some possible future work is highlighted
2/10/2021: Summary of Changes to the Chemistry Program
No full textSummary of changes and rationale
The following changes are being implemented:
Removal of CHEM 247 as a course requirement for the Chemistry, Biochemistry, and Applied Biology Programs and deletion of the course
Change the number of required elective courses from 12 to 10 credits.
Change credit hours for upper division lab courses CHEM 352, CHEM 362, CHEM 364, CHEM 374, and CHEM 438 from 2 credits to 3 credits
Revision of CHEM 494
Creation of new service course: CHEM 381 – 3D Printing
Minor course changes to Chem 135, 437, 438
Please see attached Summary, Course Change Form
3/24/2021: Course Change Form CS6823
No full textThis is a version of the CS 682 course that will be used in the MEng program. The general content is roughly the same with the exception that lectures on large datasets and reinforcement learning have been removed. For other topics the depth of coverage of each topic will be slightly less to match the 3 versus 4 credit hours and the needs of the MEng students
3/24/2021: Course Change Form MGMT6093
No full textThe addition of this course supports the management component of the MEng degree program. MGMT 6093 will be one of the two required management courses in all four of the MEng concentrations: General, Artificial Intelligence, Autonomous Vehicles, and Electrified Vehicles
3/24/2021: Course Change Form CE 695
No full textThe proposed change is so that we can comply with the changes at the registrar that has moved away from P/F to S/U grading
Analysis of MAP/PH/1 Queueing System with Degrading Service Rate and Phase Type Vacation
No full textDegradation of services arises in practice due to a variety of reasons including wear-and-tear of machinery and fatigue. In this paper, we look at MAP/PH/1-type queueing models in which degradation is introduced. There are several ways to incorporate degradation into a service system. Here, we model the degradation in the form of the service rate declining (i.e., the service rate decreases with the number of services offered) until the degradation is addressed. The service rate is reset to the original rate either after a fixed number of services is offered or when the server becomes idle. We look at two models. In the first, we assume that the degradation is instantaneously fixed, and in the second model, there is a random time that is needed to address the degradation issue. These models are analyzed in steady state using the classical matrix-analytic methods. Illustrative numerical examples are provided. Comparisons of both the models are drawn
