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Full-Text Articles in Physical Sciences and Mathematics

Multi-Device Data Analysis For Fault Localization In Electrical Distribution Grids, Jacob D L Hunte Apr 2022

Multi-Device Data Analysis For Fault Localization In Electrical Distribution Grids, Jacob D L Hunte

Electronic Thesis and Dissertation Repository

The work presented in this dissertation represents work which addresses some of the main challenges of fault localization methods in electrical distribution grids. The methods developed largely assume access to sophisticated data sources that may not be available and that any data sets recorded by devices are synchronized. These issues have created a barrier to the adoption of many solutions by industry. The goal of the research presented in this dissertation is to address these challenges through the development of three elements. These elements are a synchronization protocol, a fault localization technique, and a sensor placement algorithm.

The synchronization protocol …


High Multiplicity Strip Packing Problem With Three Rectangle Types, Andy Yu Nov 2019

High Multiplicity Strip Packing Problem With Three Rectangle Types, Andy Yu

Electronic Thesis and Dissertation Repository

The two-dimensional strip packing problem (2D-SPP) involves packing a set R = {r1, ..., rn} of n rectangular items into a strip of width 1 and unbounded height, where each rectangular item ri has width 0 < wi ≤ 1 and height 0 < hi ≤ 1. The objective is to find a packing for all these items, without overlaps or rotations, that minimizes the total height of the strip used. 2D-SPP is strongly NP-hard and has practical applications including stock cutting, scheduling, and reducing peak power demand in smart-grids.

This thesis considers …


Optimization Studies And Applications: In Retail Gasoline Market, Daero Kim Jun 2018

Optimization Studies And Applications: In Retail Gasoline Market, Daero Kim

Electronic Thesis and Dissertation Repository

The study of the retail gasoline market is of great interest in financial economics, since it allows many theories about price formation, oligopolistic markets, and consumer search to be tested. In addition, the risk management of gasoline prices is an important instance of the management of any consumable commodity cost. For the retailer, the tool of dynamic pricing may be found to be useful.

This thesis contributes to the study of retail gasoline markets in three main ways, each in its own paper. The first paper tests various economic models to confirm earlier results about pricing behavior in retail gasoline …


Probability Models For Health Care Operations With Application To Emergency Medicine, Azaz Bin Sharif Feb 2016

Probability Models For Health Care Operations With Application To Emergency Medicine, Azaz Bin Sharif

Electronic Thesis and Dissertation Repository

This thesis consists of four contributing chapters; two of which are inspired by practical problems related to emergency department (ED) operations management and the remaining two are motivated by the theoretical problem related to the time-dependent priority queue. Unlike classical priority queue, priorities in the time-dependent priority queue depends on the amount of time an arrival waits for service in addition to the priority class they belong. The mismatch between the demand for ED services and the available resources have direct and indirect negative consequences. Moreover, ED physician pay in some jurisdictions reflects pay-for-performance contracts based on operational benchmarks. To …


Recent Advances In Accumulating Priority Queues, Na Li Dec 2015

Recent Advances In Accumulating Priority Queues, Na Li

Electronic Thesis and Dissertation Repository

This thesis extends the theory underlying the Accumulating Priority Queue (APQ) in three directions. In the first, we present a multi-class multi-server accumulating priority queue with Poisson arrivals and heterogeneous services. The waiting time distributions for different classes have been derived. A conservation law for systems with heterogeneous servers has been studied. We also investigate an optimization problem to find the optimal level of heterogeneity in the multi-server system. Numerical investigations through simulation are carried out to validate the model.

We next focus on a queueing system with Poisson arrivals, generally distributed service times and nonlinear priority accumulation functions. We …


Optimal Contract Design For Co-Development Of Companion Diagnostics, Rodney T. Tembo Sep 2014

Optimal Contract Design For Co-Development Of Companion Diagnostics, Rodney T. Tembo

Electronic Thesis and Dissertation Repository

As the number of new drugs requiring companion diagnostics rises, more and more partnerships are formed between drug and diagnostics manufacturers to develop the necessary companion diagnostic. An increasingly significant issue is that of the optimal revenue/profit sharing or compensation schemes for such partnerships. We investigate the structure of an optimal compensation scheme under a scenario where a large pharmaceutical firm that is developing a drug intends to partner with a smaller diagnostics firm to develop a companion diagnostic test for the drug. We describe an optimal contract as one that maximizes the pharmaceutical firm's expected profits while offering enough …


High Multiplicity Strip Packing, Devin Price Mar 2014

High Multiplicity Strip Packing, Devin Price

Electronic Thesis and Dissertation Repository

An instance of the two-dimensional strip packing problem is specified by n rectangular items, each having a width, 0 < wn ≤ 1, and height, 0 < hn ≤ 1. The objective is to place these items into a strip of width 1, without rotations, such that they are nonoverlapping and the total height of the resulting packing is minimized. In this thesis, we consider the version of the two-dimensional strip packing problem where there is a constant number K of distinct rectangle sizes and present an OPT + K - 1 polynomial-time approximation algorithm for it. This beats a previous algorithm …