Engineering Commons^™

An Improved Earned Value Management Method Integrating Quality And Safety, Brian Briggs

LSU Doctoral Dissertations

The construction industry invests significant time and money to improve quality and safety while reducing cost and schedule impacts. The industry has a sincere desire to improve construction project management methods to improve efficiency. Historically, quality and safety underperformances result from undermanaged quality control and safety activities. The cost and schedule impacts associated with poor quality work have always had an impact on construction operations. The unprecedented challenges and uncertainties of COVID-19 highlighted the need to improve the Earned Value Management (EVM) method within construction to reflect these quality and safety activities. The central goal of this dissertation is to …

Advanced Methods For Steady-State And Stability Analyses Of Hybrid Power Systems, Mohammad Mehdi Rezvani

LSU Doctoral Dissertations

The term hybrid power grids refer to the combination of two power systems with different intrinsic characteristic. For instance, ac-dc grids and transmission-distribution systems are kinds of hybrid power grids. Challenges in analyzing the hybrid power grids arise since two sets of equations should be solved either simultaneously or sequentially. In the simultaneous (unified) methods, the ac and dc system of equations are solved simultaneously, while, in the sequential approaches, these equations are solved in an error loop. In this dissertation, a unified method is proposed for steady-state and fault analyses of hybrid ac-dc power grids, while a sequential approach …

Semantics-Guided Human Motion Modeling In Virtual Reality Environment, Matthew Korban

LSU Doctoral Dissertations

Human Motion Modeling is essential in Computer Animation and Human-Computer Interaction. This dissertation studies how to enhance the speed and robustness of Human Motion Modeling in Virtual Reality (VR) environments. Specifically, we aim to design a pipeline to effectively capture and use semantic action information to guide the motion capturing from users in physical worlds and its transfer onto digital avatars in VR environments. To recognize the user's action, we first proposed a new Dynamic Directed Graph Convolutional Network (DDGCN) to model spatial and temporal features from users' skeletal representations. The DDGCN consists of several dynamic feature modeling modules to …

Error Prevention In Sensors And Sensor Systems, Pedro J. Chacon Dominguez

LSU Doctoral Dissertations

Achievements in all fields of engineering and fabrication methods have led towards optimization and integration of multiple sensing devices into a concise system. These advances have caused significant innovation in various commercial, industrial, and research efforts. Integrations of subsystems have important applications for sensor systems in particular. The need for reporting and real time awareness of a device’s condition and surroundings have led to sensor systems being implemented in a wide variety of fields. From environmental sensors for agriculture, to object characterization and biomedical sensing, the application for sensor systems has impacted all modern facets of innovation. With these innovations, …

A Comprehensive Study On Printed Circuit Board Backdoor Coupling In High Intensity Radiated Fields Environments, Ryan Patrick Tortorich

LSU Doctoral Dissertations

Due to the prevalence of unintentional electromagnetic interference (EMI) and the growth of intentional electromagnetic interference (IEMI) or high power microwave (HPM) sources, it is now more important than ever to understand how electronic systems are affected by high intensity radiated fields (HIRF) environments. Both historic events and experimental testing have demonstrated that HIRF environments are capable of disrupting and potentially damaging critical systems including but not limited to civil and military aircraft, industrial control systems (ICS), and internet of things (IoT) devices. However, there is limited understanding on the complex electromagnetic interactions that lead to such effects. This study …

Led-Based Optical Sensing Platforms For Multi-Analyte Detection, Youngho Shin

LSU Doctoral Dissertations

Real-time monitoring of phytoplankton groups provides important information about aquatic ecological states, nutrient abundance, and water pollution. A rapid and accurate method for monitoring phytoplankton in water is commonly performed by detecting fluorescence emission from the plankton; however, commercially available portable fluorescence sensors are still expensive, bulky, and limited in functions, such as lacking the capability of selectively detecting multiple phytoplankton groups. In this regard, a low-cost and portable fluorometer platform for phytoplankton detection was developed in order to address the issues that current portable fluorometers have.

This dissertation has four main goals: (1) perform a study on fluorescence measurement …

Channel Estimation In Multi-User Massive Mimo Systems By Expectation Propagation Based Algorithms, Mohammed Rashid

LSU Doctoral Dissertations

Massive multiple input multiple output (MIMO) technology uses large antenna arrays with tens or hundreds of antennas at the base station (BS) to achieve high spectral efficiency, high diversity, and high capacity. These benefits, however, rely on obtaining accurate channel state information (CSI) at the receiver for both uplink and downlink channels. Traditionally, pilot sequences are transmitted and used at the receiver to estimate the CSI. Since the length of the pilot sequences scale with the number of transmit antennas, for massive MIMO systems downlink channel estimation requires long pilot sequences resulting in reduced spectral efficiency and the so-called pilot …