Engineering Commons^™

Constrained Biogeography-Based Optimization For Invariant Set Computation,, Arpit Shah, Daniel Simon, Hanz Richter

Hanz Richter

We discuss the application of biogeography-based optimization (BBO) to invariant set approximation. BBO is a recently developed evolutionary algorithm (EA) that is motivated by biogeography, which is the study and science of the geographical migration of biological species. Invariant sets are sets in the state space of a dynamic system such that if the state begins in the set, then it remains in the set for all time. Invariant sets have applications in many constrained control problems, and their computation amounts to a constrained optimization problem. We therefore frame the invariant set computation problem as a constrained optimization problem, and …

Seismic Isolation Of A Highly Skewed, Prestressed Concrete Girder Bridge, Bradley Robson, Issam Harik, David Allen

Issam E. Harik

A relatively new approach for designing or retrofitting highway bridges in seismic zones involves isolating the superstructure from the substructure. Through experimental and analytical investigations, this study evaluates the effectiveness of isolating one particular bridge: a highly skewed, prestressed concrete, slab-on-girder bridge. Dynamic testing of the bridge was performed using the pullback, quick-release method. A three dimensional finite element model of the bridge was created. It was refined, or calibrated, to match experimentally determined natural frequencies and mode shapes. Time-history analyzes, using site-specific acceleration records, were conducted for the seismically isolated bridge model and an identical, non-isolated bridge model.

For …

Optimization Of Threshold Values For Estimators Based On Single-Bit Quantized Sensors Using Genetic Algorithms, Nishant Unnikrishnan, Ajay Mahajan, Antonios Mengoulis, R. Viswanathan

Dr. Ajay Mahajan

The paper considers the problem of signal parameter estimation using a collection of distributed sensors called a sensor pack. Each sensor quantizes its data to one-bit information and sends it to a fusion processor for the estimation of the parameter. Estimation of a constant signal in additive noise is considered. Estimators are formulated based on one-bit sensor data and their mean squared error (MSE) performances are evaluated through simulation studies. It is shown that selecting certain threshold values for quantizing the sensor outputs can lower the MSE. Genetic algorithms are used to find the optimal threshold values for the sensors. …

Genetic Algorithms — A Novel Technique To Optimize Coal Preparation Plants, Vishal Gupta, Manoj Mohanty, Ajay Mahajan, S. Biswal

Dr. Ajay Mahajan

A coal preparation plant typically operates with multiple cleaning circuits based on the particle size distribution of run-of-mine coal. Clean coal product from a plant commonly has to satisfy multiple product quality constraints, including product ash, product sulfur, heating value, moisture content, etc. Numerous studies in the past illustrate that the optimal yield of the plant can be obtained by operating each circuit to produce the same incremental product quality. This equal incremental product quality approach optimizes the plant yield considering only one product quality at a time. Thus, when required to simultaneously satisfy multiple product quality constraints, the process …

Performance Optimization Of A Coal Preparation Plant Using Genetic Algorithms, Vishal Gupta, Manoj Mohanty, Ajay Mahajan, Surendra Biswal

Dr. Ajay Mahajan

A coal preparation plant typically has multiple cleaning circuits based on size of coal particles. The traditional way of optimizing the plant output and meeting the product constraints such as ash, sulfur and moisture content is to equalize the average product quality from each circuit. The present study includes multiple incremental product quality approach to optimize the clean coal recovery while satisfying the product constraints. The plant output was optimized at the given constraints of 7.5% ash and 1.3% sulfur. It was observed that utilizing incremental product quality process gives 2.13% higher yield which can generate additional revenue of $4,260,000 …

A Decision Support Model For The Location Of Hand Sanitizer Dispensers In Hospitals, Laila Cure

Laila Cure

Compliance with hand hygiene practices is directly affected by the accessibility and availability of cleaning agents. Nevertheless, the decision of where to locate these dispensers is often not explicitly or fully addressed in the literature. In this paper, we study the problem of selecting the locations to install alcohol-based hand sanitizer dispensers throughout a hospital unit. We investigate the relevant criteria in selecting dispenser locations that promote compliance with hand hygiene practices, propose metrics for the evaluation of various location configurations, and formulate a dispenser location optimization model that incorporates such criteria. A complete methodology to collect data and obtain …

Minimizing Hidden-Node Network Interference By Optimizing Siso And Mimo Spectral Efficiency, Daniel Bliss, Siddhartan Govindasamy

Siddhartan Govindasamy

In this paper, the optimal spectral efficiency (data rate divided by the message bandwidth) that minimizes the probability of causing disruptive interference for ad hoc wireless networks or cognitive radios is investigated. Two basic problem constraints are considered: a given message size, or fixed data rate. Implicitly, the trade being optimized is between longer transmit duration and wider bandwidth versus higher transmit power. Both single-input single-output (SISO) and multiple-input multiple-output (MIMO) links are considered. Here, a link optimizes its spectral efficiency to be a “good neighbor.” The probability of interference is characterized by the probability that the signal power received …

Multi-Channel Peer-To-Peer Streaming Systems As Resource Allocation Problems, Miao Wang

Miao Wang

In the past few years, the Internet has witnessed the success of Peer-to-Peer (P2P) streaming technology, which has attracted millions of users. More recently, commercial P2P streaming systems have begun to support multiple channels and a user in such systems is allowed to watch more than one channel at a time. We refer to such systems as multi-channel P2P streaming systems. In this dissertation, we focus on designing multi-channel P2P streaming systems with the goal of providing optimal streaming quality for all channels, termed as system-wide optimal streaming quality. Specifically, we design the systems from the perspective of how to …

Jamming-Aware Traffic Allocation For Multiple-Path Routing Using Portfolio Selection, Patrick Tague, Sidharth Nabar, James Ritcey, Radha Poovendran

Patrick Tague

Multiple-path source routing protocols allow a data source node to distribute the total traffic among available paths. In this article, we consider the problem of jamming-aware source routing in which the source node performs traffic allocation based on empirical jamming statistics at individual network nodes. We formulate this traffic allocation as a lossy network flow optimization problem using portfolio selection theory from financial statistics. We show that in multi-source networks, this centralized optimization problem can be solved using a distributed algorithm based on decomposition in network utility maximization (NUM). We demonstrate the network’s ability to estimate the impact of jamming …