Engineering Commons^™

Study Of Fundamental Tradeoff Between Deliverable And Private Information In Statistical Inference, Farhang Bayat

LSU Doctoral Dissertations

My primary objective in this dissertation is to establish a framework under which I launch a systematic study of the fundamental tradeoff between deliverable and private information in statistical inference. My research was partly motivated by arising and prevailing privacy concerns of users in many machine learning problems.

In this dissertation, I begin by introducing examples where I am concerned of privacy leakage versus decision utility in statistical inference problems. I then go into further details about what I have achieved in formulating and solving such problems using information theory related metrics in a variety of settings. Both related works …

Noble-Transition Alloy Absorbers For Near-Infrared Hot-Carrier Optoelectronics, Sara Karoline Figueiredo Stofela

LSU Doctoral Dissertations

Optoelectronics is the field of technology concerned with the study and application of electronic devices that source, detect and control light. Here we focus on the optical communications field which relies on optical fiber systems to carry signals to their destinations operating in the near-infrared range. To improve the performance of current optical fiber systems, one of the paths is to develop better near-infrared photodetectors.

The current group of materials used for near-infrared photodetection relies in the III-V semiconductor family. Although their spectral photosensitivity correlates well with the near-infrared, response time performance and electronic circuit integration remain limited for this …

Bio-Mechanical Characterization Of Adherent Cell Layers With A Pdms Cantilever, Merrel Truly Holley

LSU Doctoral Dissertations

In the last few decades, the mechanical characteristics of human cells has been linked to many physiological processes and pathological conditions, illustrating the importance as effective biomarkers. Mounting research has shown the mechanical force between cells and the extracellular matrix (ECM) plays a vital role in cellular processes such as tissue homeostasis, wound healing, cancer metastasis, and the progression of various diseases. This mechanical force, or the force that a cell produces on its surroundings, is termed as the cellular traction force (CTF). Precise characterization of the CTF can expand our knowledge of these important cellular processes as well as …

Unidirectional And Nonreciprocal Nanophotonic Devices Based On Graphene And Magneto-Optical Materials, Vahid Foroughi Nezhad

LSU Doctoral Dissertations

In this dissertation, we first introduce compact tunable spatial mode converters for graphene parallel plate (GPP) waveguides. The converters are reciprocal and based on spatial modulation of graphene’s conductivity. The wavelength of operation of the mode converters is tunable in the mid-infrared wavelength range by adjusting the chemical potential of a strip on one of the graphene layers of the GPP waveguides. We also introduce optical diodes for GPP waveguides based on a spatial mode converter and a coupler, which consists of a single layer of graphene placed in the middle between the two plates of two GPP waveguides. \par …

Neurostimulator With Waveforms Inspired By Nature For Wearable Electro-Acupuncture, Jose Aquiles Parodi Amaya

LSU Doctoral Dissertations

The work presented here has 3 goals: establish the need for novel neurostimulation waveform solutions through a literature review, develop a neurostimulation pulse generator, and verify the operation of the device for neurostimulation applications.

The literature review discusses the importance of stimulation waveforms on the outcomes of neurostimulation, and proposes new directions for neurostimulation research that would help in improving the reproducibility and comparability between studies.

The pulse generator circuit is then described that generates signals inspired by the shape of excitatory or inhibitory post-synaptic potentials (EPSP, IPSP). The circuit analytical equations are presented, and the effects of the circuit …

Graph Information Processing For Artificial Intelligence, Limeng Pu

LSU Doctoral Dissertations

In the last decade, techniques for artificial intelligence (AI) has advanced tremendously, which lead to solutions to many problems that have long-troubled us. Such examples include image/video recognition, speech recognition, and 3D scenario recognition. As the tool become more and more powerful, we started to explore data types that have never been handled in an AI fashion. Graph is undoubtedly the first one that comes to mind. Many important real-life data is or can be represented as graphs or networks: social networks, communication networks, protein-protein interaction networks, molecular structures, etc. Yet very little attention has been devoted to the study …

System Identification Based On Errors-In-Variables System Models, Hyundeok Kang

LSU Doctoral Dissertations

We study the identification problem for errors-in-variables (EIV) systems. Such an EIV model assumes that the measurement data at both input and output of the system involve corrupting noises. The least square (LS) algorithm has been widely used in this area. However, it results in biased estimates for the EIV-based system identification. In contrast, the total least squares (TLS) algorithm is unbiased, which is now well-known, and has been effective for estimating the system parameters in the EIV system identification.

In this dissertation, we first show that the TLS algorithm computes the approximate maximum likelihood estimate (MLE) of the system …

Cost Effective, Highly Efficient Wireless Power Transfer Systems For Ev Battery Charging, Amir Masoud Bozorgi

LSU Doctoral Dissertations

The impact of changing inner diameter of wireless power transfer (WPT) coils on coupling coefficient is studied. It is demonstrated that at a certain outer and inner coil diameter, turn space variation has minor effect on the coupling coefficient. Next, two compensation networks, namely primary LCC and secondary LCC, which offer load-independent voltage transfer ratio and zero voltage switching for WPT, are presented. For both compensation networks, the condition for having zero voltage switching operation are derived. In addition, load-independent voltage transfer ratio (VTR) frequencies are obtained and VTR at each frequency is derived. Then, required equations for calculation of …

Developing An Optomechanical Approach For Characterizing Mechanical Properties Of Single Adherent Cells, Ali Mehrnezhad

LSU Doctoral Dissertations

Mechanical properties of a cell reflect its biological and pathological conditions including cellular disorders and fundamental cellular processes such as cell division and differentiation. There have been active research efforts to develop high-throughput platforms to mechanically characterize single cells. Yet, many of these research efforts are focused on suspended cells and use a flow-through configuration. Therefore, adherent cells are detached prior to the characterization, which seriously perturbs the cellular conditions. Also, methods for adherent cells are limited in their throughput.

My study is aimed to fill the technical gap in the field of single cell analysis, which is a high-throughput …

Optimal And Efficient Decision-Making For Power System Expansion Planning, Mahdi Mehrtash

LSU Doctoral Dissertations

A typical power system consists of three major sectors: generation, transmission, and distribution. Due to ever increasing electricity consumption and aging of the existing components, generation, transmission, and distribution systems and equipment must be analyzed frequently and if needed be replaced and/or expanded timely. By definition, the process of power system expansion planning aims to decide on new as well as upgrading existing system components in order to adequately satisfy the load for a foreseen future.

In this dissertation, multiple economically optimal and computationally efficient methods are proposed for expanding power generation, transmission, and distribution systems. First, a computationally efficient …

A Model-Based Framework For The Smart Manufacturing Of Polymers, Santiago D. Salas Ortiz

LSU Doctoral Dissertations

It is hard to point a daily activity in which polymeric materials or plastics are not involved. The synthesis of polymers occurs by reacting small molecules together to form, under certain conditions, long molecules. In polymer synthesis, it is mandatory to assure uniformity between batches, high-quality of end-products, efficiency, minimum environmental impact, and safety. It remains as a major challenge the establishment of operational conditions capable of achieving all objectives together. In this dissertation, different model-centric strategies are combined, assessed, and tested for two polymerization systems.

The first system is the synthesis of polyacrylamide in aqueous solution using potassium persulfate …

Thermal And Mechanical Energy Harvesting Using Lead Sulfide Colloidal Quantum Dots, Taher Ghomian

LSU Doctoral Dissertations

The human body is an abundant source of energy in the form of heat and mechanical movement. The ability to harvest this energy can be useful for supplying low-consumption wearable and implantable devices. Thermoelectric materials are usually used to harvest human body heat for wearable devices; however, thermoelectric generators require temperature gradient across the device to perform appropriately. Since they need to attach to the heat source to absorb the heat, temperature equalization decreases their efficiencies. Moreover, the electrostatic energy harvester, working based on the variable capacitor structure, is the most compatible candidate for harvesting low-frequency-movement of the human body. …

Economic Approaches And Market Structures For Temporal-Spatial Spectrum Sharing, Feixiang Zhang

LSU Doctoral Dissertations

In wireless communication systems, economic approaches can be applied to spectrum sharing and enhance spectrum utilization.

In this research, we develop a model where geographic information, including licensed areas of primary users (PUs) and locations of secondary users (SUs), plays an important role in the spectrum sharing system. We consider a multi-price policy and the pricing power of noncooperative PUs in multiple geographic areas. Meanwhile, the value assessment of a channel is price-related and the demand from the SUs is price-elastic. By applying an evolutionary procedure, we prove the existence and uniqueness of the optimal payoff for each PU selling …

Techniques Of Energy-Efficient Vlsi Chip Design For High-Performance Computing, Zhou Zhao

LSU Doctoral Dissertations

How to implement quality computing with the limited power budget is the key factor to move very large scale integration (VLSI) chip design forward. This work introduces various techniques of low power VLSI design used for state of art computing. From the viewpoint of power supply, conventional in-chip voltage regulators based on analog blocks bring the large overhead of both power and area to computational chips. Motivated by this, a digital based switchable pin method to dynamically regulate power at low circuit cost has been proposed to make computing to be executed with a stable voltage supply. For one of …

Spectrum- And Energy-Efficient Radio Resource Allocation For Wireless Communications, Shengjie Guo

LSU Doctoral Dissertations

Wireless communications has been evolved significantly over the last decade. During this period, higher quality of service (QoS) requirements have been proposed to support various services. In addition, due to the increasing number of wireless devices and transmission, the energy consumption of the wireless networks becomes a burden. Therefore, the energy efficiency is considered as important as spectrum efficiency for future wireless communications networks, and spectrum and energy efficiency have become essential research topics in wireless communications. Moreover, due to the exploding of number mobile devices, the limited radio resources have become more and more scarce. With large numbers of …

Decentralized Optimal Control With Application In Power System, Boyu Wang

LSU Doctoral Dissertations

An output-feedback decentralized optimal controller is proposed for power systems with renewable energy penetration. Renewable energy source is modeled similar to the classical generator model and is equipped with the unified power flow controller (UPFC). The transient performance of power system is considered and stability of the dynamical states are investigated. An offline decentralized optimal controller is designed that utilizes only the local states. The network comprises conventional synchronous generators as well as renewable sources with inverter equipped with UPFC. Subsequently, the optimal decentralized controller is compared to the initial stabilizing controller used to obtain the optimal controller. An online …

A Study Of Scalability And Cost-Effectiveness Of Large-Scale Scientific Applications Over Heterogeneous Computing Environment, Arghya K. Das

LSU Doctoral Dissertations

Recent advances in large-scale experimental facilities ushered in an era of data-driven science. These large-scale data increase the opportunity to answer many fundamental questions in basic science. However, these data pose new challenges to the scientific community in terms of their optimal processing and transfer. Consequently, scientists are in dire need of robust high performance computing (HPC) solutions that can scale with terabytes of data.

In this thesis, I address the challenges in three major aspects of scientific big data processing as follows: 1) Developing scalable software and algorithms for data- and compute-intensive scientific applications. 2) Proposing new cluster architectures …

Voltage-Controlled Deposition Of Nanoparticles For Next Generation Electronic Materials, Subhodip Maulik

LSU Doctoral Dissertations

This work presents both a feasibility study and an investigation into the voltage-controlled spray deposition of different nanoparticles, namely, carbon nanotubes (CNTs), as well as molybdenum disulfide (MoS₂) and tungsten disulfide (WS₂) from the transition metal dichalcogenides (TMDCs) family of materials. The study considers five different types of substrates as per their potential application to next-generation device electronics. The substrates selected for this research were: 1) aluminum as a conducting substrate, 2) silicon as a semiconducting substrate, 3) glass, silicon dioxide (SiO₂), and syndiotactic poly methyl methacrylate (syndiotactic PMMA) as insulating substrates.

Since the …

Hypothesis Testing And Model Estimation With Dependent Observations In Heterogeneous Sensor Networks, Sima Sobhiyeh

LSU Doctoral Dissertations

Advances in microelectronics, communication and signal processing have enabled the development of inexpensive sensors that can be networked to collect vital information from their environment to be used in decision-making and inference. The sensors transmit their data to a central processor which integrates the information from the sensors using a so-called fusion algorithm. Many applications of sensor networks (SNs) involve hypothesis testing or the detection of a phenomenon. Many approaches to data fusion for hypothesis testing assume that, given each hypothesis, the sensors' measurements are conditionally independent. However, since the sensors are densely deployed in practice, their field of views …

Advanced Modeling, Design, And Control Of Ac-Dc Microgrids, Hossein Saberi Khorzoughi

LSU Doctoral Dissertations

An interconnected dc grid that comprises resistive and constant-power loads (CPLs) that is fed by Photovoltaic (PV) units is studied first. All the sources and CPLs are connected to the grid via dc-dc buck converters. Nonlinear behavior of PV units in addition to the effect of the negative-resistance CPLs can destabilize the dc grid. A decentralized nonlinear model and control are proposed where an adaptive output-feedback controller is employed to stabilize the dc grid with assured stability through Lyapunov stability method while each converter employs only local measurements. Adaptive Neural Networks (NNs) are utilized to overcome the unknown dynamics of …

Image Processing Applications In Real Life: 2d Fragmented Image And Document Reassembly And Frequency Division Multiplexed Imaging, Houman Kamran Habibkhani

LSU Doctoral Dissertations

In this era of modern technology, image processing is one the most studied disciplines of signal processing and its applications can be found in every aspect of our daily life. In this work three main applications for image processing has been studied.

In chapter 1, frequency division multiplexed imaging (FDMI), a novel idea in the field of computational photography, has been introduced. Using FDMI, multiple images are captured simultaneously in a single shot and can later be extracted from the multiplexed image. This is achieved by spatially modulating the images so that they are placed at different locations in the …

Plasmonic Structures For Subwavelength Guiding And Enhanced Light-Matter Interactions, Amirreza Mahigir

LSU Doctoral Dissertations

In this dissertation we design and analyze nanostructures for subwavelength guiding and enhanced light-matter interactions.

We first investigate three-dimensional plasmonic waveguide-cavity structures, built by side-coupling stub resonators that consist of plasmonic coaxial waveguides of finite length, to a plasmonic coaxial waveguide. These structures are capable of guiding and manipulating light in deep-subwavelength volumes. We show that three-dimensional plasmonic coaxial waveguides offer a platform for practical realization of deep-subwavelength optical waveguides.

We then introduce compact wavelength-scale slit-based structures for coupling free space light into the fundamental mode of plasmonic coaxial waveguides. We consider single-, double-, and triple-slit structures optimized at the …

Surface Enhanced Raman Scattering (Sers) Substrates And Probes, Srismrita Basu

LSU Doctoral Dissertations

Raman spectroscopy is a well-known technique for complex molecular detection. In Raman spectrometry, laser beam is focused on a sample to generate a unique "fingerprint" of the molecule. The Raman signal is very weak. To overcome this problem nano rough metallic substrates are fabricated to enhance the signal strength. In clinical applications, remote contact and minimally invasive probes inside the specimen are needed.

This research work is divided in: (1) development of Surface Enhanced Raman Scattering (SERS) substrate using gold coated etched aluminum foil, (2) development of the SERS probe using the aluminum based substrate with a single optical fiber …

A Study Of Very Short Intermittent Ddos Attacks On The Performance Of Web Services In Clouds, Huasong Shan

LSU Doctoral Dissertations

Distributed Denial-of-Service (DDoS) attacks for web applications such as e-commerce are increasing in size, scale, and frequency. The emerging elastic cloud computing cannot defend against ever-evolving new types of DDoS attacks, since they exploit various newly discovered network or system vulnerabilities even in the cloud platform, bypassing not only the state-of-the-art defense mechanisms but also the elasticity mechanisms of cloud computing.

In this dissertation, we focus on a new type of low-volume DDoS attack, Very Short Intermittent DDoS Attacks, which can hurt the performance of web applications deployed in the cloud via transiently saturating the critical bottleneck resource of the …

Modeling Of Thermally Aware Carbon Nanotube And Graphene Based Post Cmos Vlsi Interconnect, K M Mohsin

LSU Doctoral Dissertations

This work studies various emerging reduced dimensional materials for very large-scale integration (VLSI) interconnects. The prime motivation of this work is to find an alternative to the existing Cu-based interconnect for post-CMOS technology nodes with an emphasis on thermal stability. Starting from the material modeling, this work includes material characterization, exploration of electronic properties, vibrational properties and to analyze performance as a VLSI interconnect. Using state of the art density functional theories (DFT) one-dimensional and two-dimensional materials were designed for exploring their electronic structures, transport properties and their circuit behaviors. Primarily carbon nanotube (CNT), graphene and graphene/copper based interconnects were …

Hierarchical Fusion Based Deep Learning Framework For Lung Nodule Classification, Kazim Sekeroglu

LSU Doctoral Dissertations

Lung cancer is the leading cancer type that causes the mortality in both men and women. Computer aided detection (CAD) and diagnosis systems can play a very important role for helping the physicians in cancer treatments. This dissertation proposes a CAD framework that utilizes a hierarchical fusion based deep learning model for detection of nodules from the stacks of 2D images. In the proposed hierarchical approach, a decision is made at each level individually employing the decisions from the previous level. Further, individual decisions are computed for several perspectives of a volume of interest (VOI). This study explores three different …

Information Theoretic Study Of Gaussian Graphical Models And Their Applications, Ali Moharrer

LSU Doctoral Dissertations

In many problems we are dealing with characterizing a behavior of a complex stochastic system or its response to a set of particular inputs. Such problems span over several topics such as machine learning, complex networks, e.g., social or communication networks; biology, etc. Probabilistic graphical models (PGMs) are powerful tools that offer a compact modeling of complex systems. They are designed to capture the random behavior, i.e., the joint distribution of the system to the best possible accuracy. Our goal is to study certain algebraic and topological properties of a special class of graphical models, known as Gaussian graphs. First, …

Protection Challenges Of Distributed Energy Resources Integration In Power Systems, Pooria Mohammadi

LSU Doctoral Dissertations

It is a century that electrical power system are the main source of energy for the societies and industries. Most parts of these infrastructures are built long time ago. There are plenty of high rating high voltage equipment which are designed and manufactured in mid-20th and are currently operating in United States’ power network. These assets are capable to do what they are doing now. However, the issue rises with the recent trend, i.e. DERs integration, causing fundamental changes in electrical power systems and violating traditional network design basis in various ways. Recently, there have been a steep rise in …

Channel Estimation And Symbol Detection In Massive Mimo Systems Using Expectation Propagation, Kamran Ghavami

LSU Doctoral Dissertations

The advantages envisioned from using large antenna arrays have made massive multiple- input multiple-output systems (also known as massive MIMO) a promising technology for future wireless standards. Despite the advantages that massive MIMO systems provide, increasing the number of antennas introduces new technical challenges that need to be resolved. In particular, symbol detection is one of the key challenges in massive MIMO. Obtaining accurate channel state information (CSI) for the extremely large number of chan- nels involved is a difficult task and consumes significant resources. Therefore for Massive MIMO systems coherent detectors must be able to cope with highly imperfect …

Modeling Of Two Dimensional Graphene And Non-Graphene Material Based Tunnel Field Effect Transistors For Integrated Circuit Design, Md Shamiul Fahad

LSU Doctoral Dissertations

The Moore’s law of scaling of metal oxide semiconductor field effect transistor (MOSFET) had been a driving force toward the unprecedented advancement in development of integrated circuit over the last five decades. As the technology scales down to 7 nm node and below following the Moore’s law, conventional MOSFETs are becoming more vulnerable to extremely high off-state leakage current exhibiting a tremendous amount of standby power dissipation. Moreover, the fundamental physical limit of MOSFET of 60 mV/decade subthreshold slope exacerbates the situation further requiring current transport mechanism other than drift and diffusion for the operation of transistors. One way to …