Engineering Commons^™

Monte-Carlo-Based Analysis Of Traffic Flow For Urban Air Mobility Vehicles, Sara Ghayouraneh

Graduate Theses and Dissertations

The research conducted in this dissertation is focused on developing a simulation tool that can predict the traffic flow patterns of the Urban Air Mobility vehicles to alleviate some of the challenges related to their traffic management. First, an introduction to the concept of Urban Air Mobility is given, the usage of Automatic Dependent Surveillance-Broadcast systems for Urban Air Mobility vehicles is suggested and dynamic addressing concept is introduced as an answer to a part of air traffic management and address scarcity challenge for Urban air Mobility vehicles. Next, in order to simulate the traffic flow patterns of the Urban …

Direct Torque Control For Silicon Carbide Motor Drives, Mohammad Hazzaz Mahmud

Graduate Theses and Dissertations

Direct torque control (DTC) is an extensively used control method for motor drives due to its unique advantages, e.g., the fast dynamic response and the robustness against motor parameters variations, uncertainties, and external disturbances. Using higher switching frequency is generally required by DTC to reduce the torque ripples and decrease stator current total harmonic distortion (THD), which however can lower the drive efficiency. Through the use of the emerging silicon carbide (SiC) devices, which have lower switching losses compared to their silicon counterparts, it is feasible to achieve high efficiency and low torque ripple simultaneously for DTC drives.

To overcome …

Use Of The Igbt Module In The Active Region To Design A High Current Active Filter, Jorge F. Galarraga

Graduate Theses and Dissertations

Particle accelerators require high-precision magnetic fields on the order or 100ppm or less. This implies that the precision of the associated electrical current in the electromagnet that generates these fields should be smaller than 100ppm. However, conventional switching power supplies cannot offer this precision due to the frequency limitation of the switches. This research considers the use of power electronics devices operating in a linear as an alternative solution to meet the requirements of particle accelerator electromagnets.

This thesis presents the study of an insulated-gate bipolar transistor (IGBT) driver using a new control method that linearizes the IGBT’s collector-emitter voltage …

Computational Modeling Of Black Phosphorus Terahertz Photoconductive Antennas Using Comsol Multiphysics With Experimental Comparison Against A Commercial Lt-Gaas Emitter, Jose Isaac Santos Batista

Graduate Theses and Dissertations

This thesis presents computational models of terahertz (THz) photoconductive antenna (PCA) emitter using COMSOL Multiphysics commercial package. A comparison of the computer simulated radiated THz signal against that of an experimentally measured signal of commercial reference LT-GaAs emitter is presented. The two-dimensional model (2D) aimed at calculating the photoconductivity of a black phosphorus (BP) PCA at two laser wavelengths of 780 nm and 1560 nm. The 2D model was applied to the BP PCA emitter and the LT-GaAs devices to compare their simulated performance in terms of the photocurrent and radiated THz signal pulse. The results showed better performance of …

Deployment Policies To Reliably Maintain And Maximize Expected Coverage In A Wireless Sensor Network, Nicholas T. Boardman

Graduate Theses and Dissertations

The long-term operation of a wireless sensor network (WSN) requires the deployment of new sensors over time to restore any loss in network coverage and communication ability resulting from sensor failures. Over the course of several deployment actions it is important to consider the cost of maintaining the WSN in addition to any desired performance measures such as coverage, connectivity, or reliability. The resulting problem formulation is approached first through a time-based deployment model in which the network is restored to a fixed size at periodic time intervals. The network destruction spectrum (D-spectrum) has been introduced to estimate reliability and …

High Temperature Degradation In Gan-Based Hall Effect Sensors, Alexis Anne Krone

Graduate Theses and Dissertations

This research focuses on understanding the effects of accelerated aging through temperature and environment on novel gallium nitride-based Hall effect magnetic field sensors and determining device reliability under electric vehicle operating conditions. The device reliability was modeled using accelerated aging for the temperatures of 200 °C, 350 °C, 450 °C, and 600 °C under various time steps unique to each temperature and either air, which is identical to operating circumstances, or argon, which would model the hermetic packaging environment. Using a high temperature furnace and oven, devices underwent high temperature storage tests at a chosen temperature and time step. Afterwards, …

Grid Strength Assessment Trough Q-V Modal Analysis And Maximum Loadability Of A Wind-Dominated Power System Using P-Q Regions, Pierre Obed Dorile

Graduate Theses and Dissertations

Climate change is a menace to the existence of the world and policymakers are trying totackle this phenomenon by deploying large-scale wind farms into their grids. Among them, wind energy shows a promising future to substitute the traditional power plants. However, the deployment of these wind farms into the grid is not a panacea that does not pose any challenges to the grid operators. Keeping the power system voltage stable while considering the strength of the transmission grid is among the major challenges facing by the transmission system operators. Amid normal operation and fault conditions, wind farms should help the …

Fabrication And Characterization Of Photodetector Devices Based On Nanostructured Materials: Graphene And Colloidal Nanocrystals, Wafaa Gebril

Graduate Theses and Dissertations

Photodetectors are devices that capture light signals and convert them into electrical signals. High performance photodetectors are in demand in a variety of applications, such as optical communication, security, and environmental monitoring. Among many appealing nanomaterials for novel photodetection devices, graphene and semiconductor colloidal nanocrystals are promising candidates because of their desirable and unique properties compared to conventional materials.

Photodetector devices based on different types of nanostructured materials including graphene and colloidal nanocrystals were investigated. First, graphene layers were mechanically exfoliated and characterized for device fabrication. Self-powered few layers graphene phototransistors were studied. At zero drain voltage bias and room …

Reference Design Of An Online Emulation And Hot-Patching Approach For Power Electronic Controller Validation, Estefano Soria Pearson

Graduate Theses and Dissertations

This thesis aims to develop a reference design of an online security system approach embedded in a power electronic controller for cybersecurity purposes. Cybersecurity in power electronics focuses on reducing vulnerabilities in the system, where most reside in the communication with the hardware devices. Although methods to secure communications lessen the probability and effects of cyber-attacks, discovering vulnerabilities is inevitable. This thesis attempts to provide a fail-safe approach to securing the system by targeting the safety of the power-electronic controller. This approach applies an additional security layer in case of a malicious or accidental controller firmware malfunction.

The online security …

Signal Processing And Data Analysis For Real-Time Intermodal Freight Classification Through A Multimodal Sensor System., Enrique J. Sanchez Headley

Graduate Theses and Dissertations

Identifying freight patterns in transit is a common need among commercial and municipal entities. For example, the allocation of resources among Departments of Transportation is often predicated on an understanding of freight patterns along major highways. There exist multiple sensor systems to detect and count vehicles at areas of interest. Many of these sensors are limited in their ability to detect more specific features of vehicles in traffic or are unable to perform well in adverse weather conditions. Despite this limitation, to date there is little comparative analysis among Laser Imaging and Detection and Ranging (LIDAR) sensors for freight detection …

Nanomaterial-Based Biosensors For Detection Of Salmonella Typhimurium And Avian Influenza Virus H5n1 In Poultry, Xinge Xi

Graduate Theses and Dissertations

This research focused on developing biosensing method and biosensing device for rapid detection of pathogens in poultry: Salmonella Typhimurium and avian influenza virus H5N1. The first part of the dissertation reports an original research on the development of a portable biosensing device for Salmonella detection. The device was designed and constructed based on a previously developed optical biosensing method, using immuno-magnetic nanoparticles to specifically capture target bacteria, and immuno-quantum dot beads to label the target bacteria for fluorescence detection. All the actions of sample mixing, magnetic separation, and fluorescence detection were controlled automatically in a disposable microfluidic chip in the …

Optimization Of Vaccine Supply Chains In Low- And Middle-Income Countries Utilizing Drones, Maximilian Kolter

Graduate Theses and Dissertations

Despite tremendous efforts from governments and humanitarian organizations, millions of children in low- and low-middle-income countries (LICs and LMICs) are still excluded from the benefits of immunization. The vaccine distribution in LICs and LMICs is challenging for several reasons, such as limited cold chain capacities, vaccine wastage, uncertain demand, and lack of access to immunization services. A promising avenue to address these issues is the utilization of drones for vaccine delivery. Drones can fly at high speed on direct paths and could enable on-demand deliveries to mitigate limited storage capacities. Further, their independence of road networks could allow them reaching …

The Impact Of Nanopulse Treatment On The Tumor Microenvironment In Breast Cancer: Overturning The Treg Immunosuppressive Dominance, Anthony Nanajian

Biomedical Sciences Theses & Dissertations

Nanopulse treatment (NPT) is a high-power electric engineering modality that has been shown to be an effective local tumor treatment approach in multiple cancer models. Our previous studies on the orthotopic 4T1-luc breast cancer model demonstrated that NPT ablated local tumors. The treatment consequently conferred protection against a second live tumor challenge and minimized spontaneous metastasis. This study aims to understand how NPT mounts a potent immune response in a predominantly immunosuppressive tumor.

NPT changed the local and systemic dynamics of immunosuppressive cells by significantly reducing the numbers of regulatory T cells (Tregs), myeloid-derived suppressor cells (MDSCs), and tumor-associated macrophages …

Quantifying Cyber Risk By Integrating Attack Graph And Impact Graph, Omer F. Keskin

Engineering Management & Systems Engineering Theses & Dissertations

Being a relatively new risk source, models to quantify cyber risks are not well developed; therefore, cyber risk management in most businesses depends on qualitative assessments. With the increase in the economic consequences of cyber incidents, the importance of quantifying cyber risks has increased. Cyber risk quantification is also needed to establish communication among decision-makers of different levels of an enterprise, from technical personnel to top management.

The goal of this research is to build a probabilistic cybersecurity risk analysis model that relates attack propagation with impact propagation through internal dependencies and allows temporal analysis.

The contributions of the developed …

Development And Applications Of Adjoint-Based Aerodynamic And Aeroacoustic Multidisciplinary Optimization For Rotorcraft, Ramiz Omur Icke

Mechanical & Aerospace Engineering Theses & Dissertations

Urban Air Mobility (UAM) is one of the most popular proposed solutions for alleviating traffic problems in populated areas. In this context, the proposed types of vehicles mainly consist of rotors and propellers powered by electric motors. However, those rotary-wing components can contribute excessively to noise generation. Therefore, a significant noise concern emerges due to urban air vehicles in or around residential areas. Reducing noise emitted by air vehicles is critically important to improve public acceptance of such vehicles for operations in densely populated areas.

Two main objectives of the present dissertation are: (1) to expand the multidisciplinary optimization to …

Wiener-Fliess Composition Of Formal Power Series: Additive Static Feedback And Shuffle Rational Series, Subbarao Venkatesh Guggilam

Electrical & Computer Engineering Theses & Dissertations

The problem statement for this dissertation is two-fold. The first problem considered is when does a Chen-Fliess series in an additive static feedback connection with a formal static map yield a closed-loop system with a Chen-Fliess series expansion? This work proves that such a closed-loop system always has a Chen-Fliess series representation. Furthermore, an algorithm based on the Hopf algebras for the shuffle group and the dynamic output feedback group is designed to compute the generating series of the closed-loop system. It is proved that the additive static feedback connection preserves local convergence and relative degree, but a counterexample shows …

A Digital One Degree Of Freedom Model Of An Electromagnetic Position Sensor, Michelle Elizabeth Weinmann

Mechanical & Aerospace Engineering Theses & Dissertations

The purpose of this project was to improve an existing system currently in use by NASA Langley Research Center (LaRC). The 6-inch Magnetic Suspension and Balance System (MSBS) built at MIT is operational with control in three degrees of freedom, with two additional degrees of freedom exhibiting passive stability. The means for measuring model displacement within the magnetic environment is an Electromagnetic Position Sensor (EPS), consisting of excitation coils at 20 kHz and multiple sets of pickup coils. The pickup coil voltages are proportional to model displacement in each degree of freedom. However, the EPS electronic signal processing system is …

What Internal Variables Affect Sensorimotor Rhythm Brain-Computer Interface (Smr-Bci) Performance?, Alex J. Horowitz, Christoph Guger, Milena Korostenskaja

HCA Healthcare Journal of Medicine

In this review article, we aimed to create a summary of the effects of internal variables on the performance of sensorimotor rhythm-based brain computer interfaces (SMR-BCIs). SMR-BCIs can be potentially used for interfacing between the brain and devices, bypassing usual central nervous system output, such as muscle activity. The careful consideration of internal factors, affecting SMR-BCI performance, can maximize BCI application in both healthy and disabled people. Internal variables may be generalized as descriptors of the processes mainly dependent on the BCI user and/or originating within the user. The current review aimed to critically evaluate and summarize the currently accumulated …

What External Variables Affect Sensorimotor Rhythm Brain-Computer Interface (Smr-Bci) Performance?, Alex J. Horowitz, Christoph Guger, Milena Korostenskaja

HCA Healthcare Journal of Medicine

Sensorimotor rhythm-based brain-computer interfaces (SMR-BCIs) are used for the acquisition and translation of motor imagery-related brain signals into machine control commands, bypassing the usual central nervous system output. The selection of optimal external variable configuration can maximize SMR-BCI performance in both healthy and disabled people. This performance is especially important now when the BCI is targeted for everyday use in the environment beyond strictly regulated laboratory settings. In this review article, we summarize and critically evaluate the current body of knowledge pertaining to the effect of the external variables on SMR-BCI performance. When assessing the relationship between SMR-BCI performance and …

Journal Of Pre-College Engineering Education Research (J-Peer) Annual Report From January 1, 2020 To December 31, 2020, Senay Purzer, Kami N. Schwatz

Journal of Pre-College Engineering Education Research (J-PEER)

Over the last ten years, the Journal of Pre-College Engineering Education Research (J-PEER) has been disseminating research that seeks to investigate, enhance, and transform pre-college engineering education and, ultimately, to create an engineering‐literate society. The 2020 annual report presents readership metrics and statistics of the decade, trends and metrics on J-PEER's authorship in 2020, and our reflections on the last year.

Properties Of Concrete Containing Crushed Limestone As Total Replacement Of Natural Sand And Recycled Engine Oil, Mohammad El Bast M. El Bast, Jamal Khatib, Oussama Baalbaki, Adel Elkordi

BAU Journal - Science and Technology

The rapid growth in the construction industry at the global level has made concrete the most widely used construction material throughout the world. Accordingly, the consumption of natural sand which is one the main raw material constituent of concrete is continuously growing. The demand for river sand is highly increasing due to its scarcity in the market. Manufactured sand produced by crushed rock is being considered as an appropriate alternative to replace river sand in concrete. In recent years, there is a growing interest in the use of crushed sand obtained from limestone quarries in some countries where river sand …

Dynamic Soil-Structure Interaction Analysis: Detecting The Reliability Of Modelling The Piles As A Plate Element For A Multistory Building Resting On Deep Foundation, Zeinab Hussein Zein Z.H.Zein, Lina Jaber L. Jaber, Yehya Temsah Y. Temsah

BAU Journal - Science and Technology

The assessment of seismic responses of buildings in dynamic-soil-pile-structure interaction problems has been one of the main interests among researchers in recent decades. Simulating such problems is usually done by two-dimensional models to overcome the difficulties encountered in 3D models. Commonly, piles were represented by plate elements of infinite length, disregarding the soil flowing between piles. Recently, Plaxis – a finite element software- implemented a new feature known as “the embedded pile row” that allows the definition of piles' out of plane spacing in a 2D model. Many researchers proved its validity in accurately simulating the real 3D pile’s behavior. …

A Novel Probabilistic Framework Of Rc Corroded Structures Under Dynamic Loading, Rawan Mouin Mashmoushy Eng., Wael Slika, Adel Elkordi

BAU Journal - Science and Technology

Steel corrosion in reinforced concrete structures can lead to severe deterioration damage under static and seismic loads. In practice, it is essential to mitigate failure risk by quantifying the extent of damage and simulating the structural response of damaged structures. However, numerical modeling of the dynamic behavior of corroded structure is challenging due to high nonlinearity of the problem and its multidisciplinary nature. In addition, corrosion damage exhibits various sources of uncertainty that impede accurate deterministic modeling of the dynamic response of RC structures. Therefore, this study presents a simplified framework, to simulate the non-linear response of corroded structures under …

Technology Of Mobility Hubs In Autopian Futuristic Cities, Mohamad Abdallah M.Abdallah, Marwan Halabi, Hiba Mohsen, Maged Youssef

BAU Journal - Science and Technology

Utopias envision perfect societies, however in practice, when imperfect humans attempt perfection they fail miserably. Hence, if Utopia means no place, then Autopia is the alternative place where progress is steadfast and measured by securing a better world for tomorrow. In 2012, the UN issued a report stating that population growth will increase exponentially, reaching up to 9 billion by 2040. The report also states that melted ice due to global warming will eventually cover up to 7% of the world’s land. At this rate, humans will require three times the earth’s land area to keep up with their required …

Optimization Of Supermarket Checkout Counters Using Integrated Greedy Algorithm, Ramzi Fayad, Hadi Abou Chakra

BAU Journal - Science and Technology

Supermarkets worldwide are facing a service dilemma whether to increase or decrease their number of counters used at checkouts. A higher number of checkouts will undoubtedly reduce waiting time at checkout, a factor in improving customer satisfaction and service quality but this will come at a cost to the Supermarket. The work conducted in this paper will therefore focus on this tradeoff between improving the customer shopping experience versus the Supermarket Cost and profitability margins. It will do so by using an optimization algorithm that can help find the optimum number of checkouts and utilization of staff resources. The optimization …

Comparative Study Of Nano-Rod And Nano-Sphere Based Localized Surface Plasmon Resonance Refractive Index Biosensors, Mariam M. Moussilli M. M. Moussilli, Abdul Rahman El Falou

BAU Journal - Science and Technology

Localized Surface Plasmon Resonance (LSPR) waves generated by the interaction of light with noble metal nanoparticles has been of great interest in recent years due to the high sensitivity of the extinction spectra of these nanoparticles to the medium's surrounding refractive index up to the atomic level.

In this article, we simulate the extinction spectra of noble metal sphere and rod nanoparticles in order to study the effect of the geometrical shape and size of the nanoparticle on the sensitivity and detection accuracy performance parameters of the extinction spectra. We also simulated the response of the sphere and rod nanoparticle's …

An Improvement Of Cross Entropy Thresholding For Skin Cancer, Nancy Aref Zreika N, A. Zreika, Ali El Zaart, Abdallah Al Shakik

BAU Journal - Science and Technology

Image processing procedures in medical diagnosis are used to improve diagnosis accuracy. An example of this is skin cancer detection using the thresholding approach. Thus, research studies involved in identification of inherited mutations predisposing family members to malignant melanoma have been performed in the Cancer Genetics field. Melanoma is one of the deadliest cancers, but could be cured when diagnosed early. A fundamental step in image processing is segmentation that includes thresholding, among others. Thresholding is based on finding the optimal thresholds value that partitions the image into multiple classes to be able to distinguish the objects from the background. …

Unsteady Rotational Motion Of A Micropolar Fluid Inside A Right Circular Cylinder Using State Space Approach, Sarah Ahmad Slayi S.A.Slayi, Emad Ashmawy

BAU Journal - Science and Technology

In this work, the unsteady rotational motion of an incompressible micropolar fluid inside a right circular cylinder is investigated. The classical no-slip and no-spin boundary conditions are proposed. The problem is solved analytically using the state space approach together with Laplace transform technique. The inverse Laplace transform is carried out numerically using a numerical technique based on Fourier series expansion. Numerical results for the flow field functions are represented graphically for different values of the time and micropolarity parameters.

Impact Of Regional Climate Changes On Changes In River Water Content In Uzbekistan, A.T. Salokhiddinov, P.A. Khakimova, R.V. Toryanniova, O.A. Ashirova, A.G. Gofurov

Irrigation and Melioration

The paper presents the research results on the analysis of the climate change impacts on the potential of water resources in Central Asia. We analyzed the materials of an extensive database of monitoring data from numerous gauge stations on different river basins and satellite data information. A quantitative assessment of the transformation of river hydrographs, the growth of flow variability in the Republic of Uzbekistan's major rivers, in connection with climate change, was performed. The specific features of the impact of climate changes on changes in the water content of rivers in Uzbekistan in large and small river basins are …

Washing Technology For Medium And Highly Saline Soils, B.K. Saliev, M. S. Yuldashev, N.O. Shaimanov

Irrigation and Melioration

The article discusses the issues of conducting field experiments to assess the reclamation conditions of soils, which are a particular issue of managing salinity and water-salt regime, as well as increasing the efficiency of desalination. Today, 46.6% of the irrigated lands of the Republic of Uzbekistan have salinization of varying degrees, of which 30.9% are weak, 13.3% are moderate and 2.5% are highly saline. Medium and highly saline lands make up 15.8%. The essence of the proposed method of flushing from the traditional one is that in late autumn or winter, the collectors-ditches are closed, and the groundwater is artificially …