Engineering Commons^™

Optimization With Genetic Algorithm Of Temperature-Dependent Fiber Length Of L-Band Edfa Gain, Murat Yücel, Damt Adnan Mustafa Mustafa

Turkish Journal of Electrical Engineering and Computer Sciences

Erbium-doped fiber amplifiers (EDFAs) have great importance in long-distance communication. It is required to have equal gain for all signals that are transferred and to avoid loss in the receiver of long-distance communication systems. However, temperature dependence changes the output spectrum of the designed gain-flattening systems. In this study, each erbium-doped fiber (EDF) length of a two-stage L-band EDFA has been optimized using a genetic algorithm method; because of the temperature dependence of EDFAs, there is no general rule. Thus, a simple, fast, dynamic, and highly accurate model has been developed and obtained for different EDF lengths that will fix …

Gravitational Search Algorithm For Determining Controller Parameters In An Automatic Voltage Regulator System, Serhat Duman, Nuran Yörükeren, İsmai̇l Hakki Altaş

Turkish Journal of Electrical Engineering and Computer Sciences

proportional-integral-derivate (PID) controller for an automatic voltage regulator (AVR) system using a heuristic gravitational search algorithm (GSA) based on mass interactions and Newton's law of gravity. The determination of optimal controller parameters is considered an optimization problem in which different performance indexes and a performance criterion in the time domain have been used as objective functions to test the performance and effectiveness of the GSA. In the determining process of the parameters, the designed PID controller with the proposed approach is simulated under different conditions and the performance of the controller is compared with those reported in the literature. From …

Approximation For Single-Channel Multi-Server Queues And Queuing Networks With Generally Distributed Inter-Arrival And Service Times, Carlos Roberto Chaves

Doctoral Dissertations

"This dissertation is divided into two papers. The first paper is related to developing a closed-form approximation for single-channel multiple-server queues with generally distributed inter-arrival and service times, which are often found in numerous settings, e.g., airports and manufacturing systems. Unfortunately, exact models for such systems require distributions for the underlying random variables. Further, data for fitting distributions is sometimes not available, and one only has access to means and variances of the underlying input random variables. Under heavy traffic, excellent approximations already exist for this purpose. In the first paper, a new approximation method for medium traffic is presented. …

An Efficient Method For Optimizing Segmentation Parameters, Jacob D' Avy, Wei-Wen Hsu, Chung-Hao Chen, Andreas F. Koschan, Mongi Abidi

Electrical & Computer Engineering Faculty Publications

Segmenting an image into meaningful regions is an important step in many computer vision applications such as facial recognition, target tracking and medical image analysis. Because image segmentation is an ill-posed problem, parameters are needed to constrain the solution to one that is suitable for a given application. For a user, setting parameter values is often unintuitive. We present a method for automating segmentation parameter selection using an efficient search method to optimize a segmentation objective function. Efficiency is improved by utilizing prior knowledge about the relationship between a segmentation parameter and the objective function terms. An adaptive sampling of …

Applications Of Simulation And Optimization Techniques In Optimizing Room And Pillar Mining Systems, Angelina Konadu Anani

Doctoral Dissertations

"The goal of this research was to apply simulation and optimization techniques in solving mine design and production sequencing problems in room and pillar mines (R&P). The specific objectives were to: (1) apply Discrete Event Simulation (DES) to determine the optimal width of coal R&P panels under specific mining conditions; (2) investigate if the shuttle car fleet size used to mine a particular panel width is optimal in different segments of the panel; (3) test the hypothesis that binary integer linear programming (BILP) can be used to account for mining risk in R&P long range mine production sequencing; and (4) …

Utility-Scale Solar Energy Use Optimization By Using A Home Energy Management System, Mustafa A. Syed

All ETDs from UAB

Home energy management systems encourages the users coupled to the grid to modify their electricity consumption in response to fluctuating electricity rates. The purpose of this research is to develop a distributed home energy management system for the end-user to employ in order to minimize costs. Using the home energy management system, the end-user will find and optimal start times for their appliances in response to varying electricity prices. First, the cost for each user and time-constraints for the appliance is modeled. Then, an iterative greedy algorithm is employed by the user to create an appliance schedule. The only variable …

Automating Intensity Modulated Radiation Therapy Treatment Planning By Using Hierarchical Optimization, Paras Babu Tiwari

McKelvey School of Engineering Graduate Student Theses & Dissertations

The intensity modulated radiation therapy (IMRT) optimizes the beam’s intensity to deliver the prescribed dose to the target while minimizing the radiation exposure to normal structures. The IMRT optimization is a complex optimization problem because of the multiple conflicting objectives in it. Due to the complexity of the optimization, the IMRT treatment planning is still a trial and error process. Hierarchical optimization was proposed to automate the treatment planning process, but its potential has not been demonstrated in a clinical setting. Moreover, hierarchical optimization is slower than the traditional optimization. The dissertation studied a sampling algorithm to reduce the hierarchical …

Spacecraft Trajectory Optimization Suite (Stops): Optimization Of Multiple Gravity Assist Spacecraft Trajectories Using Modern Optimization Techniques, Timothy J. Fitzgerald

Master's Theses

In trajectory optimization, a common objective is to minimize propellant mass via multiple gravity assist maneuvers (MGAs). Some computer programs have been developed to analyze MGA trajectories. One of these programs, Parallel Global Multiobjective Optimization (PaGMO), uses an interesting technique known as the Island Model Paradigm. This work provides the community with a MATLAB optimizer, STOpS, that utilizes this same Island Model Paradigm with five different optimization algorithms. STOpS allows optimization of a weighted combination of many parameters. This work contains a study on optimization algorithm performance and how each algorithm is affected by its available settings.

STOpS successfully found …

Kinematic Control Of Redundant Mobile Manipulators, Mustafa Mashali

USF Tampa Graduate Theses and Dissertations

A mobile manipulator is a robotic arm mounted on a robotic mobile platform. In such a system, the degrees of freedom of the mobile platform are combined with that of the manipulator. As a result, the workspace of the manipulator is substantially extended. A mobile manipulator has two trajectories: the end-effector trajectory and the mobile platform trajectory. Typically, the mobile platform trajectory is not defined and is determined through inverse kinematics. But in some applications it is important to follow a specified mobile platform trajectory. The main focus of this work is to determine the inverse kinematics of a mobile …

Design And Control Of Chromatography Step In An Integrated Column Sequence, Bernt Nilsson, Niklas Andersson, Anders Holmqvist, Anton Sellberg, Peter Tiainen, Arne Staby

Integrated Continuous Biomanufacturing II

Integration of the purification steps in downstream processing is one way to minimize the number of storage tanks and reduce hold-up time. The result is an integrated column sequence that performs straight through processing of the target protein, with minimal time from expression to formulation. This paper discusses the overall integration design and its expected performance, together with a more detailed analysis of the step behavior based on column simulations. The optimal design of the individual steps in the sequence is presented, both with robustness margins and local control system, as well as with and without local recycle.

An optimization …

Evaluating Facility Design And Capacity Planning Decisions For Clinical And Commercial Supply With Hybrid Continuous Processes, Suzanne Farid

Integrated Continuous Biomanufacturing II

Assessing the value potential of alternative process and facility design strategies will be critical to the successful management of continuous processes. UCL’s Decisional Tools team have developed advanced decision-support tools that effectively integrate concepts from bioprocess economics, dynamic simulation, risk analysis, combinatorial optimization and operations research to address such challenges (e.g. 1-5). This presentation will show our latest practical applications of such models to industrially-relevant problems related to facility design and capacity sourcing for long-term commercial supply when dealing with processes with either continuous upstream or downstream processes. The results can be translated across a range of products such as …

Bioprocess Economics And Optimization Of Continuous And Pre-Packed Disposable Chromatography, Richard Allmendinger, Suzanne Farid

Integrated Continuous Biomanufacturing II

The biotech sector is facing increasing pressures to design more cost-efficient, robust and flexible manufacturing processes. Standard batch chromatography (BATCH) is an established but expensive approach to separate impurities related with both E.coli and mammalian cells expression systems. This study uses a computational framework to investigate if the application of continuous chromatography (CONTI) and disposable technologies can provide a competitive alternative to BATCH and reusable equipment. A set of general assumptions is presented on how some of the key downstream processing characteristics, such as chromatography operating conditions, resin properties and equipment requirements, vary as a function of the chromatography mode …

Process Optimization To Enhance Quality And Quantity Of Transiently Expressed Proteins | Biological Engineering, Usu College Of Engineering

College of Engineering News

Transient transfection is a method to introduce foreign DNA into a healthy cell population. Transient transfection can be accomplished by chemical, mechanical, and electrical delivery. Although foreign DNA is not incorporated into the host cell genome, host cell machinery is used to transcribe and translate the gene of interest. This presentation will illustrate the enhancement of transgene production through reagent optimization and feeds and show benefits of transient work, such as, eliminating the need for generation of a stable engineered cell line; allowing the process scaleability; and decreasing the time for generation of comparable amounts of product.

Role Of Thermal Conductivity For Thermoelectrics With Finite Contacts, Yee Rui Koh, Kazuaki Yazawa, Ali Shakouri

International Thermal Conductivity Conference (ITCC) and the International Thermal Expansion Symposium (ITES)

The role of thermal conductivity in the performance of thermoelectric (TE) devices as compared to other material properties such as Seebeck coefficient and the electrical conductivity will be discussed. A TE energy conversion system that includes thermal contacts for the hot side and the cold side with finite heat transfer performances is considered. Some of the trends in electronics cooling applications have been described. In this article, the effect of material properties as a function of energy current flow direction will be focused.

TEs have an advantage as solid-state heat energy conversion devices especially for applications with spatial constraints. A …

Engineering Optimization: Methods/Applications - Colorado State University, John Labadie

All ECSTATIC Materials

This course provides a comprehensive treatment of methods of optimization with focus on linear programming and its extensions, network flow optimization, integer programming, quadratic programming, and an introduction to nonlinear programming. The goal is to maintain a balance between theory, numerical computation, problem setup for solution by computer algorithms, and engineering applications. Course taught at Colorado State University.

Water Resources Systems Analysis - University Of Texas San Antonio, Marcio Giacomoni

All ECSTATIC Materials

Systems Analysis methods use algorithmic and mathematical approaches for problem-solving. These are powerful methods that can be applied to solve complex design and management problems for water resources systems and other engineering areas. This class will focus on optimization methods, such as linear programming, integer programming, nonlinear programming, genetic algorithms, and dynamic programming, and their application to water resources systems. Advanced Systems Analysis methods, including sensitivity analysis, alternatives generation, and multi-objective optimization will be introduced to address the complexities associated with public sector decision-making. Course taught at University of Texas San Antonio.

Environmental Systems Analysis - Hong Kong University Of Science And Technology, Hong Kong, Ng Tze Ling

All ECSTATIC Materials

Undergraduate course in environmental systems analysis offered at Hong Kong University of Science and Technology, Hong Kong in Fall 2015.

Improving Response Characteristics Of Split Ring Resonators Using Experimental Designs, Omer Faruk Keskin

Engineering Management & Systems Engineering Theses & Dissertations

The purpose of this thesis is to investigate the application of design of experiments approaches in the analysis of split ring resonators, and to compare two different approaches. The design parameters of the meta-material device are examined to study all the main effects, the two factor interactions, and the curvature effects. A full factorial design and a central composite design is utilized for the study. The results in improving split ring resonator design are discussed.

This study shows that the design of experiments approaches can effectively be utilized to examine the effects on the response values of a specific type …

Cfd Simulation And Shape Optimization Of Supersonic Ejectors For Refrigeration And Desalination Applications, Liju Su

McKelvey School of Engineering Graduate Student Theses & Dissertations

The aim of this thesis is to investigate the detailed flow field inside the supersonic ejector using numerical methods and to optimize the ejector’s mixing chamber wall shape to obtain a maximum entrainment ratio (ER) in order to obtain the highest possible efficiency that can be attained by the ejector. A steam ejector applied in the cooling industry is first studied to determine the most accurate turbulence model for its supersonic jet flow field simulation with mixing with the entrained steam in the mixing chamber. A commercial Computational Fluid Dynamics (CFD) package FLUENT 14.5 along with the meshing tool ICEM …

Optimization Of Blalock-Taussig Shunt And Anastomotic Geometry For Vascular Access Fistula Using A Genetic Algorithm, Guangyu Bao

McKelvey School of Engineering Graduate Student Theses & Dissertations

Blalock-Taussig (BT) shunts are used for defects that affect the flow of blood from the right ventricle, through the pulmonary artery, and to the lungs. Arteriovenous (AV) fistula is one type of vascular access which is a surgically created vein used to remove and return blood during hemodialysis. Plastic grafts used in the above two reconstructions may result in areas of non-physiologic flow in the grafts leading to risk of stenosis (blocked area) and thrombosis, which is the single major cause for access morbidity. The focus of this thesis is to study BT shunts and anastomoses models using Computational Fluid …

Analysis Of The Fabrication Conditions In Organic Field-Effect Transistors, Rachel M. Rahn, Yan Zhao, Jianguo Mei

The Summer Undergraduate Research Fellowship (SURF) Symposium

Polymer-based organic field-effect transistors have raised substantial awareness because they enable low-cost, solution processing techniques, and have the potential to be implemented in flexible, disposable organic electronic devices. The performance of these devices is highly dependent on the processing conditions, as well as the intrinsic properties of the polymer. Processing conditions play an important role in semiconductor film formation and device performance. These factors may provide an important link between structure and performance. In this study, an empirical analysis tool, Process Scout, was applied to assess processing factors such as polymer concentration and silicon modification. This sanctioned the creation of …

Optimization In The Simulation Of Jammed Polyhedral Particles, Joseph W. Mynhier, Ishan Srivastava, Timothy S. Fisher

The Summer Undergraduate Research Fellowship (SURF) Symposium

Energy loss due to poor transport properties in electrically and thermally conducting materials, such as battery electrodes and thermoelectric composites, contributes to the energy inefficiency of electronic devices. For conductive materials composed of granular materials, particle-particle contact topology strongly governs the efficiency of energy transfer. Although there is a large body of existing work on the arrangements made by granular materials comprised of spherical particles, less is known about the mechanically stable arrangements of granular materials made of convex polyhedra. This project seeks to create a computer simulation of the solidification of convex polyhedra from a diffuse state into a …

Ad-Hoc Automated Teller Machine Failure Forecast And Field Service Optimization, Michelle L. F. Cheong, Ping Shung Koo, B. Chandra Babu

Research Collection School Of Computing and Information Systems

As part of its overall effort to maintain good customer service while managing operational efficiency and reducing cost, a bank in Singapore has embarked on using data and decision analytics methodologies to perform better ad-hoc ATM failure forecasting and plan the field service engineers to repair the machines. We propose using a combined Data and Decision Analytics Framework which helps the analyst to first understand the business problem by collecting, preparing and exploring data to gain business insights, before proposing what objectives and solutions can and should be done to solve the problem. This paper reports the work in analyzing …

Design Method For Wideband Circularly Polarized Slot Antennas, Adam Narbudowicz, Matthias John, Vit Sipal, Xiulong Bao, Max Ammann

Articles

A compact ultrawideband (UWB) circularly polarized (CP) slot antenna is proposed with a methodology for automated reoptimization for packaging with proprietary devices. The slot structure employs a dual-feed with an integrated compact UWB phase shifter. The design process involves an advanced optimization algorithm and demonstrates the use of spline curves for generation of CP signals. These allow easy optimization, while preserving phase coherency across a wideband. The prototyped antennahas a CP bandwidth of 54% (from 3.2 to 6.1 GHz).

Comparison Of Two Wake Models For Use In Gradient-Based Wind Farm Layout Optimization, Jared Thomas, Eric Tingey, Andrew Ning

Faculty Publications

Wind farm layout has a significant impact on the productivity of a wind farm. To ensure that the turbines are placed in the most advantageous arrangement, optimization algorithms are often used during the layout design process. Depending on the wake model used for the optimization, optimizing the layout can be time intensive or potentially inaccurate. In this paper we present a comparison of optimization results using two simple wake models, the FLORIS model and the Jensen model. Results highlight some of the key similarities and differences of layout optimization results when different wake models are used.

A Methodology For The Optimization Of Disaggregated Space System Conceptual Designs, Robert E. Thompson

Theses and Dissertations

Optimal design techniques have proven to be an effective systems engineering tool. Using systems architecture as the foundation, this research explores the use of mixed variable optimization models for synthesizing and evaluating disaggregated space system concepts. Model-based conceptual design techniques are used to identify and assess system architectures based upon estimated system cost, performance trades, and cost risk. The Disaggregated Integral System Concept Optimization (DISCO) methodology is introduced, and then applied to representative space-based missions. Several results are obtained that indicate significant cost effectiveness gains from the optimization of multi-orbit and multi-function/multi-orbit disaggregated space systems. The general methodology has broad …

Strasbaugh Nonconforming Report Optimization, Eden Andersen, Angela Asgekar, Rebecca Gregg

Industrial and Manufacturing Engineering

This paper strives to convey the problems and proposed solutions for Strasbaugh’s Nonconforming Report (NCR) Optimization. Strasbaugh is a world leader in silicon wafer polisher and grinder technologies. After a significant down size to the company parts they used to manufacture now have to be purchased, and many of these incoming parts do not conform to Strasbaugh’s high standards. This has led to an increase in NCRs that need to be processed, which takes up time, resources and money.

The objective therefore became to update the multi-sheet carbon copy paper system to better optimize the use of these reports and …

The Arched Flexure Vsa: A Compact Variable Stiffness Actuator With Large Stiffness Range, Joseph M. Schimmels, Daniel Garces

Mechanical Engineering Faculty Research and Publications

The high stiffness of conventional robots is beneficial in attaining highly accurate positioning in free space. High stiffness, however, limits a robot's ability to perform constrained manipulation. Because of the high stiffness, geometric conflict between the robot and task constraints during constrained manipulation can lead to excessive forces and task failure. Variable stiffness actuators can be used to adjust the stiffness of robot joints to allow high stiffness in unconstrained directions and low stiffness in constrained directions. Two important design criteria for variable stiffness actuation are a large range of stiffness and a compact size. A new design, the Arched …

Uncertainty-Integrated Surrogate Modeling For Complex System Optimization, Ali Mehmani

Dissertations - ALL

Approximation models such as surrogate models provide a tractable substitute to expensive physical simulations and an effective solution to the potential lack of quantitative models of system behavior. These capabilities not only enable the efficient design of complex systems, but is also essential for the effective analysis of physical phenomena/characteristics in the different domains of Engineering, Material Science, Biomedical Science, and various other disciplines. Since these models provide an abstraction of the real system behavior (often a low-fidelity representative) it is important to quantify the accuracy and the reliability of such approximation models without investing additional expensive system evaluations (simulations …

Application-Specific Memory Subsystems, Joseph George Wingbermuehle

McKelvey School of Engineering Graduate Student Theses & Dissertations

The disparity in performance between processors and main memories has

led computer architects to incorporate large cache hierarchies in

modern computers. These cache hierarchies are designed to be

general-purpose in that they strive to provide the best possible

performance across a wide range of applications. However, such a memory

subsystem does not necessarily provide the best possible performance for

a particular application.

Although general-purpose memory subsystems are desirable when the

work-load is unknown and the memory subsystem must remain fixed,

when this is not the case a custom memory subsystem may be beneficial.

For example, in an application-specific integrated circuit …