Engineering Commons^™

A Novel Optimum Pi Controller Design Based On Stability Boundary Locussupported Particle Swarm Optimization In Avr System, Mahmut Temel Özdemi̇r

Turkish Journal of Electrical Engineering and Computer Sciences

This study proposes a new approach that combines stability and optimization in the design of proportional? integral (PI) controller of automatic voltage regulators (AVR) of synchronous generators with variable system parameters. Thanks to this approach, a PI controller, providing the desired performance and the stability of the AVR system, has been designed. The approach follows a method investigating the PI gain values to achieve the desired goals. In the first step of the study, a new stability boundary locus is calculated for the case in which AVR system?s parameters have changed. The stability boundary locus (SBL) method is a graphic-based …

A Novel Data Placement Strategy To Reduce Data Traffic During Run-Time, Sridevi Sridhar, Rhymend Uthariaraj Vaidyanathan

Turkish Journal of Electrical Engineering and Computer Sciences

High impact scientific applications processed in distributed data centers often involve big data. To avoid the intolerable delays due to huge data movements across data centers during processing, the concept of moving tasks to data was introduced in the last decade. Even after the realization of this concept termed as data locality, the expected quality of service was not achieved. Later, data colocality was introduced where data groupings were identified and then data chunks were placed wisely. However, the aspect of the expected data traffic during run time is generally not considered while placing data. To identify the expected data …

Performance Improvement Of The Shunt Active Power Filter Using A Novel Adaptivefiltering Approach, Abderrezzaq Zoghbi, Daoud Berkani

Turkish Journal of Electrical Engineering and Computer Sciences

This paper introduces an efficient control approach to enhance harmonics mitigation performance of the shunt active power filter (SAPF). This approach is based on adaptive filters favored by their built-in automatic parameters adaptation capability. The proposed filter, which uses a variable leaky least mean square (VLLMS) adaptation, is applied with a modified instantaneous power PQ theory. This enhances its dynamic performance over the use of conventional time-invariant filters, and overcomes its limitations in the presence of nonsinusoidal voltage conditions. The studied SAPF model is simulated in MATLAB/SIMULINK with combinations of nonlinear and unbalanced loads. Simulation results indicate a significant improvement …

A Two-Stage Hair Region Localization Method For Guided Laser Hair Removal, Murat Avşar, İmam Şami̇l Yeti̇k

Turkish Journal of Electrical Engineering and Computer Sciences

Removal of hair using laser is a widely used method, where our goal is to permanently remove hair by using laser to cause heat in order to thermally damage the hair follicle. However, currently available laser hair removal systems affect the outer skin layers besides hair follicles. This is a disadvantage of classical methods with major health risks. We propose a method to overcome these health risks by guiding the laser beam only to automatically localized hair regions. This study aims to develop an automated feature-based hair region localization method as an integral part of the proposed hair removal system …

Investigation Of Spontaneously Patterned Nanoporous Organosilicate Thin Film Channels For Liquid Chromatography Applications., Ashwin Sanjay Bhaskaran

Graduate Research Theses & Dissertations

Microscale devices are attractive options for the advancement of biomedical engineering and life science. They have huge potential in the pharmaceutical and biomedical fields provided the critical factors such as device size, product purity and efficiency are not a hindrance. In most cases, traditional microelectronics fabrication processes are quite costly and complicated. By improving on them, their application in fields such as chemical sensing, detection and analysis is possible. By implementing this on a chip, we can reduce the cost and improve portability. This thesis focuses on the investigation of a novel class of spontaneously patterned nanoporous organosilicate nanoparticle-based films …

Application Of Data And Geospatial Analysis In Energy And Health Systems, Ali Faghani

Graduate Research Theses & Dissertations

Having sustainable energy and health systems are the main factors in the vision plan of every country. Both of these systems are correlated with a variety of frameworks, including social, physical, technological, political, and economic factors. Therefore, different types of analytics methods can be implemented to develop the required assessments for those who make plans since understanding the effect of such factors individually, also their interactions, and the overall effect is crucial. With this regard, applications of data analysis and geospatial techniques in both energy, and health systems have recently gained attention. The proposed research here deployed advanced data analytics …

Thermal/Structural Analysis Of The Axion Quantum Metrology Cavity And Its Components, Tyler Funk

Graduate Research Theses & Dissertations

This research was centered around maximizing the capability to cool dielectric material within a containment unit, or Photonic Band Gap (PBG) cavity, designed for detecting axion dark matter and identifying the unit’s thermal properties. There are multiple types of PBG cavities, but the latest version that axion researchers wish to use has been theorized to contain possible issues related to its thermal properties. Thermal conductivity is an issue with the dielectric material because it is made from alumina which is highly insulative. This is important since the research is being done in a cryogenic environment and the thermal noise affects …

Microfluidics Design Considering Hyperuniformity And Cell Transport In Flow For Improved Circulating Tumor Cell Capture Efficiency, Michael Clarence Hood

Graduate Research Theses & Dissertations

Isolation of circulating tumor cells (CTCs) from patient derived blood samples for cancerdiagnostics and monitoring is challenging due to the extremely low CTC concentration. This thesis work evaluates the performance of passive microfluidics devices with different designs based on computational modeling. A new cell separation method is proposed based on velocity differentiation of varying cell sizes. All numerical studies were conducted in 2D based on a fluid structure interaction code where the fluid flow was solved based on the lattice Boltzmann method (LBM) implemented in Palabos, and the cell dynamics were simulated based on the molecular dynamics package LAMMPS, with …

Hydrocarbons In The Niobrara Formation, Powder River Basin, Northeast Wyoming, From Geophysical Well Logs, Jennifer Shilo James

Graduate Research Theses & Dissertations

The Powder River Basin, located in Wyoming, is a moderate producer of hydrocarbons with production hovering around 100 million barrels of oil per year. Recently the Niobrara Formation has garnered attention for hydrocarbon exploration and production using both conventional and unconventional drilling. A quick-look method for evaluating organic content, using either existing or real time data sets gathered from geophysical well logs, provides an opportunity to rapidly, accurately, and economically assess the formation’s organic content and thus hydrocarbon bearing potential. The popular Schmoker method determines organic content by relating gamma ray intensity to formation density. It has been successfully employed …

Coaxially Electrospun Fibrous Polymer Scaffolds For Tissue Regeneration And Drug Delivery, Matthew Michael Kleszynski

Graduate Research Theses & Dissertations

A biomaterial is a substance that is specifically engineered to take on a role within the body, either alone or in conjunction with other materials, with the purpose of influencing the body. Using Polymers as a biomaterial is an exciting field of study that has the potential to further our abilities to help those in need. Creating composite nanofibrous scaffolds composed of hydrophobic and hydrophilic polymers may outperform structures made of a single polymer in both in vitro and in vivo environments. Hydrophilicity governs the behavior of polymers in the body and has influence over the mechanical properties of the …

Optimizing Sensor Locations To Improve The Worst Case Detection Performance Of Sensor Detection Systems, Ryan Taylor Vegrzyn

Graduate Research Theses & Dissertations

This thesis discusses the optimization of distributed sensor systems to maximizedetection of an emitter at an unknown location. More specifically, this thesis discusses the creation of an algorithm that seeks to optimize the spatial positions of sensors in a distributed sensor array in order to maximize the chance of detecting an emitter even if it were to occur in the worst possible location for detection. Two versions of this algorithm are discussed. The first algorithm considers a fusion rule that detects the emitter based on the sum of all sensor measurements. The second algorithm considers the scan statistic fusion rule. …

New Features For Speech Processing Standard Pronunciation Classification, Mutian Zhuang

Graduate Research Theses & Dissertations

Pronunciation is essential in language learning. Standard English speakers could pronounce in the right way, because their pronunciation procedure is correct. The aim of this research is to see how an artificial intelligence program can be developed to provide feedback to people while they learn to generate accurate phoneme /r/. The audio signal will first be detected, after which features of audio signal will be extracted, and finally, classification will be performed. This suggested algorithm and method may be applied to other related topics. This thesis proposes new features and uses them to classify standard English speakers and non-standard English …

Large-Scale Replication Of Anisotropic Nanostructures For Development Of Anti-Reflective Surface On Glass, Amritha Narayanan

Graduate Research Theses & Dissertations

Improvement in the Anti-reflection coating (ARC) technology is considered as one of the most important advances made in modern lens design, for microscopes, cameras, and other optical devices. In the semiconductor industry, integrated circuit (IC) chip manufactures face increasing challenges posed by reflections from the underlying substrate during photolithography, a process used for the fabrication of IC’s. Without the introduction of ARC materials, the nanoscale circuitry that drives today’s modern electronic devices would not be possible. Despite its technological significance, real materialistic solutions with low refractive index (less than 1.3) are limited. Antireflection (AR) coatings today are most often based …

Blood Flow Simulation In A Microvascular Network, Kacper Ostalowski

Graduate Research Theses & Dissertations

Cardiovascular disease such as heart attack or stroke has been the leading cause of death in the US for over 100 years. Understanding the blood cell transport physics in a vascular network is important in both fundamental research and clinical practices. In this study, 3Dnumerical simulations on blood flow in a complex retina vascular network were performed considering deformable red blood cells (RBCs), white blood cells (WBCs), and obstructed vessels. The blood was modeled as a mixture of RBCs and WBCs suspended in fluid. The fluid was solved using the lattice Boltzmann method (LBM), and blood cells were modeled by …

Superconducting Cuprates: Synthesis, Characterization And Diffuse Scattering Properties, Bisham Poudel

Graduate Research Theses & Dissertations

Since its discovery more than a century ago, the fascinating phenomenon of superconductivity remains as mysterious as ever with the greatest challenge facing the condensed matter community being the elusive understanding of the microscopic origin leading to its inception. Many outstanding questions remain of which the role played by nematic fluctuations and structural disorder for the stabilization of superconductivity is not well understood. In this respect, superconducting YBa2Cu3O6+x (YBCO)-type cuprates present an ideal framework in which charge doping, structural disorder and various site manipulations can be explored in efforts to address some of these questions. Extensive synthesis and characterization efforts …

Barcode Biosensors Based On Surface Plasmon Resonance, Sneha Ramesh

Graduate Research Theses & Dissertations

Affordable and easy to use biological assays are the current need of the day owing to the rising cost of health care within the US and worldwide. The goal of this thesis is to develop a sensitive label-free biosensing scheme exploiting surface plasmon resonance (SPR) that yields the sensor output in an easy-to-read optical bio-barcode format for high through put and multiplexed medical diagnostics. Through this research, we would like to investigate if SPR phenomena can be achieved by fabricating SP supporting metallic structures over a nanoporous dielectric layer whose optical constants are progressively varied across the substrate in a …

Developing A Standard Platform To Predict The Drag Coefficient Of Irregular Shape Particles, Amin Roostaeehosseinabadi

Graduate Research Theses & Dissertations

Solid-fluid interactions are commonly observed in natural transport phenomena and industrial applications such as sedimentation in rivers and pneumatic and hydraulic conveying of coarse particles. Here particle and fluid motion affect each other through force interactions, especially via drag force. To evaluate the magnitude of the drag force first the drag coefficient (CD) of the particle needs to be measured mostly experimentally. The CD depends on the particle’s geometry (i.e., shape, dimension, …) and the properties of the fluid medium. Since the solid particles commonly observed in nature or used in industrial setups come with irregular shapes, finding a relation …

Tailoring Thermoresponsive Poly(N-Isopropylacrylamide) Toward Sensing Perfluoroalkyl Acids, Dustin Thomas Savage

Theses and Dissertations--Chemical and Materials Engineering

Widespread distribution of poly- and perfluoroalkyl substances (PFAS) in the environment combined with concerns for their potentially negative health effects has motivated regulators to establish strict standards for their surveillance. The United States Environmental Protection Agency issued a cumulative domestic threshold of 70 ppt for water supplies, and this bar is even lower in some local districts and other countries. Monitoring PFAS consequently requires sensitive analytical equipment to meet regulatory specifications, and liquid chromatography with tandem mass spectroscopy (LC/MS/MS) is the most common technique used to satisfy these requirements. Though extremely sensitive, the instrument is often burdened by pretreatment regimens, …

Development Of Novel Polymeric Materials For Their Application In Monitoring And Remediation Of Environmental Pollutants, Rishabh Shah

Theses and Dissertations--Chemical and Materials Engineering

Remediation of environmental pollutants from water is one of the major challenges in the 21st century. Utilizing novel polymeric materials to accomplish this challenge has garnered a lot of interest in recent times. Flexibility in synthesizing as well as functionalizing makes them attractive for their application in pollutant remediation. This work is based on development and characterization of novel crosslinked polymeric as well as linear polymeric materials from biphenyl-based monomers, biphenyl based crosslinker and a temperature responsive monomer (Nisopropylacrylamide (NIPAAm)) for their application in remediation of toxic pollutants such as polychlorinated biphenyls (PCBs), polyaromatic hydrocarbons (PAHs) and iron oxide nanoparticle …

A Dynamic Active Noise Control System For Live Music Attenuation, Elliot James Krueger

Graduate Research Theses & Dissertations

This thesis proposes a system design that will be suitable for applying active noise control (ANC) effectively to live musical instruments. The design consists of three parts: a signal separation section, an instrument classification section, and the active noise control section. The signal separation section will split up the music signals. The instrument classification section will identify the signals, and the ANC section will attenuate the music signal based on the previous information from the other sections. The two instruments of focus will be the trombone and tuba for their low frequency and ability to be quite loud in a …

Human-Aware Information-Theoretic Control Of Robotic Swarms, Rafal David Krzysiak

Graduate Research Theses & Dissertations

Robotic swarms provide a scalable and robust solution for monitoring large environments. In this context, the inclusion of a human has the potential advantage of incorporating prior knowledge about the target location or dynamics, thus increasing the overall efficiency of the task at hand. This is especially critical when dealing with time-intensive missions such as search and rescue. In this thesis we develop a general information-theoretic framework to control multiple autonomous robots in search and rescue missions that include a human teleoperator. Human prior knowledge is modeled to capture target location and dynamics, and a mutual information based control is …

Rebuild The Niu Split-Hopkinson Pressure Bar Apparatus For High Strain Rate Tensile Test, Dian Li

Graduate Research Theses & Dissertations

A Split-Hopkinson apparatus is a device used to dynamically test material properties for constructing constitutive model and can be used for high strain rate deformation research and experiments. NIU currently has a Split-Hopkinson apparatus that can conduct compressive tests only. The goal of this thesis is to redesign and rebuild the existing apparatus, so the high strain rate tensile tests can be conducted.

Multi-improvements were applied to the Split Hopkinson apparatus in order to improve its working performance. For conducting high strain rate tensile test, the Split-Hopkinson system has been rebuilt with a load-inversion device. The load-inversion device was designed …

Developing A Machine Learning Framework For Upwind Surveyed Regions, Witenberg Santiago Rodrigues Souza

Graduate Research Theses & Dissertations

Every year, the Oil & Gas industry loses $2B dollars due to fugitive natural gas leaks. Identifying the source of a leak is a complex challenge, especially in suburban areas where gas leakage may be mixed with other sources. Besides the multitude of possible locations for a leak in an urban area, surveying an entire city may take considerable time and funds depending on the chosen method. This work proposes a framework based on unmanned areal vehicles (UAV) to survey a region for gas leaks. To accomplish this goal, we rely on the concept of a Upwind Survey Region (USR). …

Clinical Applications And Feasibility Of Proton Ct And Proton Radiography, Christina Marie Sarosiek

Graduate Research Theses & Dissertations

Proton therapy is a form of radiation treatment for cancer that utilizes the Bragg peak to create conformal high dose regions around the tumor volume. However, the use of x-ray computed tomography (CT) and x-ray radiography for treatment planning and pre-treatment quality assurance procedures improves the achievable effectiveness of proton treatment plans (using proton CT) and the pretreatment verification (using proton radiography). Errors in the conversion from x-ray Hounsfield units (HU) to proton relative stopping powers (RSP) leads to errors in the predicted proton range. To account for the errors, 3.5% margins are included in the treatment plan. This means …

Goal Programming Approach For Bi-Objective Optimization For A Single Batch Processing Machine, Dheeban Kumar Srinivasan Sampathi

Graduate Research Theses & Dissertations

This research considers a real-time problem where jobs need to be batched and scheduled to a single batch processing machine to minimize makespan and maximum tardiness. Jobs must be placed in batches such that the machine capacity is not violated. The jobs considered have unequal ready times, unequal processing times, and unequal sizes. This research aims to develop an effective solution approach for the proposed problem. The problem under study can be denoted as 1|p-batch, sj, rj| Cmax, Tmax.

The problem under study is NP-Hard. A new Mixed Integer Linear Programming (MILP) formulation using Goal programming (MILP-G) and Column Generation …

A Theory-Supported Machine Learning Model For The Prediction Of Melt Pool Geometry And Optimal Process Window In Metal Additive Manufacturing, Sina Tayebati

Graduate Research Theses & Dissertations

Direct Energy Deposition (DED) is an additive manufacturing (AM) process capable of producing complicate-shaped or functionally graded components, and it is getting intense attention as a revolutionary technology to satisfy high demand in manufacturing process for the aerospace, automotive, and medical industries. However, the repeatability in geometries and properties of fabricated products is one of the most challenging issues for the DED process to be fully utilized, requiring comprehensive understanding of effect of processing conditions on the properties of fabricated parts, and development of relations among those conditions and properties. That is the motivation of this research. In this study, …

Object Detection And Tracking With Occlusion Handling In Autonomous Vehicles, Bhuvan Tiruttani Reddy

Graduate Research Theses & Dissertations

Object detection and tracking are important modules that need to be mastered for safe autonomous driving. Various detection and tracking algorithms have been developed in the past decade to detect and track objects accurately and efficiently in a variety of scenarios. However, most of them perform poorly during occlusion and are unable to reassociate the object IDs after the event of occlusion. In this thesis, a single unified algorithm is developed to detect, track, and display the trajectories of multiple objects in real-time, in the perceptive surroundings of an autonomous car. An Enhanced DeepSORT (EDS) tracker is proposed to better …

Evaluating And Predicting The Risk Of Algal Blooms In A Freshwater Lake Through A 4-Dimensional Approach: A Case Study On Lake Mitchell, Sumit Kumar Ghosh

Electronic Theses and Dissertations

Excessive algal growth in freshwater lakes can negatively impact ecosystems, recreation, and human health. Though algae are a natural part of freshwater ecosystems, elevated nutrient loading from anthropogenic and natural sources can lead to algal blooms. Both algae and blue-green algae (BGA) are responsible for algal blooms; however, BGA (cyanobacteria) is more dangerous. The first objective of this research was to prepare a conceptual model to understand how various environmental variables affect algae. This conceptual model was used to choose the environmental variables that help increase or decrease algae in the water environment. The second objective was to develop empirical …

Leveraging Aircraft Transponder Signals For Measuring Aircraft Fleet Mix At Non-Towered Airports, Chuyang Yang, John Mott, Darcy M. Bullock

International Journal of Aviation, Aeronautics, and Aerospace

The general aviation sector has contributed significantly to the overall growth of the aviation industry. Fleet mix and operations information is important for the analysis of both the safety and the environmental and economic impact of general aviation activity. Factual data on the impact of environment and safety is particularly important, given the scarcity of airport improvement funds and the strong stakeholder engagement that often occurs when airport investments are evaluated. The research presented herein evaluates Mode S short and extended squitter data collected from three general aviation airports over a one-month period. This article demonstrates that by utilizing the …

Free-Space Nonreciprocal Transmission Based On Nonlinear Coupled Fano Metasurfaces, Ahmed Mekawy, Dimitrios L. Sounas, Andrea Alù

Advanced Science Research Center

Optical nonlinearities can enable unusual light–matter interactions, with functionalities that would be otherwise inaccessible relying only on linear phenomena. Recently, several studies have harnessed the role of optical nonlinearities to implement nonreciprocal optical devices that do not require an external bias breaking time-reversal symmetry. In this work, we explore the design of a metasurface embedding Kerr nonlinearities to break reciprocity for free-space propagation, requiring limited power levels. After deriving the general design principles, we demonstrate an all-dielectric flat metasurface made of coupled nonlinear Fano silicon resonant layers realizing large asymmetry in optical transmission at telecommunication frequencies. We show that the …