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Essays On Perioperative Services Problems In Healthcare, Amogh S. Bhosekar
Essays On Perioperative Services Problems In Healthcare, Amogh S. Bhosekar
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One of the critical challenges in healthcare operations management is to efficiently utilize the expensive resources needed while maintaining the quality of care provided. Simulation and optimization methods can be effectively used to provide better healthcare services. This can be achieved by developing models to minimize patient waiting times, minimize healthcare supply chain and logistics costs, and maximize access. In this proposal, we study some of the important problems in healthcare operations management. More specifically, we focus on perioperative services and study scheduling of operating rooms (ORs) and management of necessary resources such as staff, equipment, and surgical instruments. We …
A Study Of Scheduling Problems With Sequence Dependent Restrictions And Preferences, Nitin Srinath
A Study Of Scheduling Problems With Sequence Dependent Restrictions And Preferences, Nitin Srinath
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In some applications like fabric dying, semiconductor wafer processing, and flexible manufacturing, the machines being used to process jobs must be set up and serviced frequently. These setup processes and associated setup times between jobs often depend on the jobs and the sequence in which jobs are placed onto machines. That is, the scheduling of jobs on machines must account for the sequence-dependent setup times as well. These setup times can be a major factor in operational costs. In fabric dyeing processes, the sequence in which jobs are processed is also important for quality, i.e., there is a strong preference …
Scheduling Control For Many-Server Queues When Customers Change Class, Mary Elizabeth Saine
Scheduling Control For Many-Server Queues When Customers Change Class, Mary Elizabeth Saine
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We consider a two class, many-server queueing system which allows for customer abandonment and class changes. With the objective to minimize the long-run average holding cost, we formulate a stochastic queueing control problem. Instead of solving this directly, we apply a fluid scaling to obtain a deterministic counterpart to the problem. By considering the equilibrium of the deterministic solution, we can solve the resulting control problem, referred to as the equilibrium control problem (ECP), and use the solution to propose a priority policy for the original stochastic queueing system. We prove that in an overloaded system, under a fluid scaling, …
Balancing And Sequencing Of Mixed Model Assembly Lines, Anas Alsayed Alghazi
Balancing And Sequencing Of Mixed Model Assembly Lines, Anas Alsayed Alghazi
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Assembly lines are cost efficient production systems that mass produce identical products. Due to customer demand, manufacturers use mixed model assembly lines to produce customized products that are not identical. To stay efficient, management decisions for the line such as number of workers and assembly task assignment to stations need to be optimized to increase throughput and decrease cost. In each station, the work to be done depends on the exact product configuration, and is not consistent across all products. In this dissertation, a mixed model line balancing integer program (IP) that considers parallel workers, zoning, task assignment, and ergonomic …
Co-Design Of Dynamic Real-Time Scheduling And Cooperative Control For Human-Agent Collaboration Systems Based On Mutual Trust, Xiaotian Wang
Co-Design Of Dynamic Real-Time Scheduling And Cooperative Control For Human-Agent Collaboration Systems Based On Mutual Trust, Xiaotian Wang
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Mutual trust is a key factor in human-human collaboration. Inspired by this social interaction, we analyze human-agent mutual trust in the collaboration of one human and (semi)autonomous multi-agent systems. In the thesis, we derive time-series human-agent mutual trust models based on results from human factors engineering. To avoid both over- trust and under-trust, we set up dynamic timing models for the multi-agent scheduling problem and develop necessary and sufficient conditions to test the schedulability of the human multi-agent collaborative task. Furthermore, we extend the collaboration between one human and multiple agents into the collaboration between multi-human network and swarm-based agents …
Improved Photolithography Scheduling In Semiconductor Manufacturing, Sreenath Chalil Madathil
Improved Photolithography Scheduling In Semiconductor Manufacturing, Sreenath Chalil Madathil
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Photolithography is typically the bottleneck process in semiconductor manufacturing. In this thesis, we present a model for optimizing photolithography job scheduling in the presence of both individual and cluster tools. The combination of individual and cluster tools that process various layers or stages of the semiconductor manufacturing process flow is a special type of flexible flowshop. We seek separately to minimize total weighted completion time and maximize on-time delivery performance. Experimental results suggest that our mathematical- and heuristic-based solution approaches show promise for real world implementation as they can help to improve resource utilization, reduce job completion times, and decrease …
Towards Viable Large Scale Heterogeneous Wireless Networks, Rahul Amin
Towards Viable Large Scale Heterogeneous Wireless Networks, Rahul Amin
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We explore radio resource allocation and management issues related to a large-scale heterogeneous (hetnet) wireless system made up of several Radio Access Technologies (RATs) that collectively provide a unified wireless network to a diverse set of users through co-ordination managed by a centralized Global Resource Controller (GRC). We incorporate 3G cellular technologies HSPA and EVDO, 4G cellular technologies WiMAX and LTE, and WLAN technology Wi-Fi as the RATs in our hetnet wireless system. We assume that the user devices are either multi-modal or have one or more reconfigurable radios which makes it possible for each device to use any available …
An Optimization Model For Class Scheduling At A Dance Studio, Chirag Ojha
An Optimization Model For Class Scheduling At A Dance Studio, Chirag Ojha
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Scheduling has been a large area of research for decades. A substantial amount of work has been done to express, classify, and solve scheduling problems. Most of these problems are computationally difficult to solve and require complex algorithms. In this thesis, we develop a mixed-integer linear program for a real world optimization problem at a dance studio. Similar to a university, the students in this studio request a particular class and instructors teach the classes under constrained resources such as a limited number of classrooms. The priorities of instructors as well as dancers are included to further mimic reality. Experimental …
A New Metaheuristic Algorithm Motivated By The Rooting Phenomena In Plants, Behzad Nemati
A New Metaheuristic Algorithm Motivated By The Rooting Phenomena In Plants, Behzad Nemati
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In this thesis, we present a new metaheuristic algorithm for analyzing challenging optimization problems. Initial testing reveals the potential for the algorithm, which is based on the rooting phenomena found in plants in nature, to quickly produce effective solutions to challenging combinatorial optimization problems in the class NP. We present computational results describing the proposed metaheuristic's efficacy for an important class of scheduling problems and discuss areas of future work and application.
A Ptas For The Uncertain Capacity Knapsack Problem, Matthew Dabney
A Ptas For The Uncertain Capacity Knapsack Problem, Matthew Dabney
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The standard NP-hard knapsack problem can be interpreted as a scheduling problem with n jobs with weights w1 . . .wn and processing times p1 . . . pn, where our goal is to order the jobs on a single machine so as to maximize the weight of all jobs completing prior to a known common deadline d. In this paper, we study the uncertain capacity knapsack problem (UCKP), a generalization of this problem in which the deadline d is not known with certainty, but rather is provided as a probability distribution, and our goal …
The Steiner Linear Ordering Problem: Application To Resource-Constrained Scheduling Problems, Mariah Magagnotti
The Steiner Linear Ordering Problem: Application To Resource-Constrained Scheduling Problems, Mariah Magagnotti
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When examined through polyhedral study, the resource-constrained scheduling problems have always dealt with processes which have the same priority. With the Steiner Linear Ordering problem, we can address systems where the elements involved have different levels of priority, either high or low. This allows us greater flexibility in modeling different resource-constrained scheduling problems. In this paper, we address both the linear ordering problem and its application to scheduling problems, and provide a polyhedral study of the associated polytopes.
Modeling Systems For Optimal Resource Allocation, Scheduling, And Decision Making, Esengul Tayfur
Modeling Systems For Optimal Resource Allocation, Scheduling, And Decision Making, Esengul Tayfur
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This dissertation focuses on the resource requirements and scheduling problem for logistic systems. We investigate solutions to this problem in two different logistic systems: logistic system of the health care facilities during emergency evacuations and delivery and distribution system of production industries. All hospitals must have an evacuation plan to ensure the safety of patients and prevent the loss of life. However, hospital operators have not been able to quantify how resource availability, the cost of acquiring those resources, and evacuation completion time are related. This research addresses this problem and contributes two methodologies to solve this problem. In the …