Engineering Commons^™

Improving Pure-Tone Audiometry Using Probabilistic Machine Learning Classification, Xinyu Song

McKelvey School of Engineering Graduate Student Theses & Dissertations

Hearing loss is a critical public health concern, affecting hundreds millions of people worldwide and dramatically impacting quality of life for affected individuals. While treatment techniques have evolved in recent years, methods for assessing hearing ability have remained relatively unchanged for decades. The standard clinical procedure is the modified Hughson-Westlake procedure, an adaptive pure-tone detection task that is typically performed manually by audiologists, costing millions of collective hours annually among healthcare professionals. In addition to the high burden of labor, the technique provides limited detail about an individual’s hearing ability, estimating only detection thresholds at a handful of pre-defined pure-tone …

Composition-Dependent Mechanisms Of Multiscale Tendon Mechanics, Fei Fang

McKelvey School of Engineering Graduate Student Theses & Dissertations

Tendons serve as an integral part of the musculoskeletal system by transferring loads from muscle to bone and providing joint mobility and stability. From the physiologically-loading perspective, while progress has been made in evaluating mechanical behavior of different types of tendons in tension, further work is needed to relate tendon mechanics to compositional and microstructural properties, particularly under non-tensile loading modalities (i.e., shear, compression). This information is vital to explore mechanisms of how mechanical signals lead to changes in tendon structure and composition to enable these tissues to function properly, including in in vivo multiaxial loading conditions. From the structural …

Hollow And Porous Plasmonic Nanostructures For Highly Efficient Chemical And Biological Sensing, Keng-Ku Liu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Localized surface plasmon resonance (LSPR) involves the collective and coherent oscillation of dielectrically confined conduction electrons. The LSPR wavelength of noble metal nanoparticles (such as gold, silver and copper), which falls into the visible and near infrared range of the electromagnetic spectrum, is sensitive to the composition, size, shape, dielectric properties of the surrounding medium, and proximity to other nanostructures (plasmon coupling). Based on the sensitivity of the surface plasmon resonance to the changes in the dielectric properties of the surrounding medium and the enhancement of the electromagnetic (EM) field in proximity of metal nanostructures, two important classes of plasmonic …

Photodynamic Therapy: Agents And Mechanisms, Rebecca Claire Gilson

McKelvey School of Engineering Graduate Student Theses & Dissertations

Despite enormous efforts, cancer remains a leading cause of morbidity and mortality world-wide. The main challenges currently facing cancer therapy include lack of adequate tumor targeting, failure to treat hypoxic tumor cells, and induction therapy resistant tumors. A solution to these limitations can be found in photodynamic therapy (PDT) which combines light and light activatable compounds, photosensitizers (PSs), to produce cytotoxic reactive oxygen species (ROS) to damage tumor tissue. This creates a spatiotemporal therapeutic effect, where cell damage only occurs at the intersection of the PS and light. PDT can treat tumors through unique mechanisms which reduce induction of tumor …

Numerical Methods For Nonlinear Optimal Control Problems And Their Applications In Indoor Climate Control, Runxin He

McKelvey School of Engineering Graduate Student Theses & Dissertations

Efficiency, comfort, and convenience are three major aspects in the design of control systems for residential Heating, Ventilation, and Air Conditioning (HVAC) units. In this dissertation, we study optimization-based algorithms for HVAC control that minimizes energy consumption while maintaining a desired temperature, or even human comfort in a room. Our algorithm uses a Computer Fluid Dynamics (CFD) model, mathematically formulated using Partial Differential Equations (PDEs), to describe the interactions between temperature, pressure, and air flow. Our model allows us to naturally formulate problems such as controlling the temperature of a small region of interest within a room, or to control …

Sorption Of Metals Onto Natural Sediments And Engineered Iron Oxide Nanoparticles, Zezhen Pan

McKelvey School of Engineering Graduate Student Theses & Dissertations

Metal contamination of subsurface environments and engineered water systems can be derived from natural processes and anthropogenic activities associated with industrial processes, past weapons production, and mining works. The toxic and carcinogenic effects of uranium and chromium pose a significant risk to the environment and human health. For uranium contamination in subsurface environments, phosphate addition has been performed for in-situ immobilization, which can avoid the costs associated with pump-and-treat or excavation-based remediation strategies. The interactions of uranium and phosphate in Hanford sediments had been insufficiently explored in terms of its site-specific groundwater chemistry and aquifer sediment properties. For water treatment …

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, …

Oblique Wave Scattering By A Submerged Porous Breakwater With A Partially Reflecting Sidewall, Yang Zhao, Hua-Jun Li, Yong Liu

Journal of Marine Science and Technology–Taiwan

This study develops an analytical solution for oblique wave scattering by a submerged porous breakwater with a leeside partially reflecting vertical wall. The matched eigenfunction expansion method is used to develop the analytical solution. The whole fluid domain is divided into three regions according to the geometries of the structures. The series solution of the velocity potential in each region is obtained by the separation of the variables, and the unknown expansion coefficients are determined using the pressure and velocity continuous conditions on interfaces of different regions. The newly developed analytical solution is confirmed by an independently developed multi-domain boundary …

Studies In Pressurized Oxy-Combustion: Process Development And Control Of Radiative Heat Transfer, Akshay Gopan

McKelvey School of Engineering Graduate Student Theses & Dissertations

Fossil fuels supply over 80% of the world’s primary energy and more than two-thirds of the world’s electricity. Of this, coal alone accounts for over 41% of the electricity supplied globally. Though coal is globally well-distributed and can provide stable and reliable energy on demand, it emits a large amount of carbon dioxide—a greenhouse gas responsible for global warming. Serious concerns over the implication of the increased global temperature have prompted the investigation into low carbon energy alternatives. The idea of capturing the carbon dioxide emitted from the combustion sources is considered as one of the viable alternatives. This would …

Minimum Induced Power For A Helicopter In High-Speed Forward Flight, Junsoo (Sean) Hong

McKelvey School of Engineering Graduate Student Theses & Dissertations

A dynamic inflow model is used to calculate minimum induced power for a helicopter in high-speed forward flight with infinite and finite number of blades. Comparisons between analytical and numerical results are shown and they show good agreement. Different flow conditions (such as with and without reverse flow or inflow feedback) are used to show how each condition affects optimum induced power. Several results confirm the findings of earlier investigations such as a singularity in rotor power in reverse flow and induced power reduction with increase in blade number. Some of the new findings are that greater inflow feedback (due …

Non-Parametric Identification Of Nonlinear Damping And Restoring Forces For Ship Free Roll Decay In Numerical Tank, Yin Jiang, Ren-Chuan Zhu, Guo-Ping Miao, Ju Fan, Chao Ma

Journal of Marine Science and Technology–Taiwan

Numerical simulations of free roll decay are carried out for the DTMB 5512 based on computational fluid dynamics (CFD) theory and adoption of overset mesh technology. The numerical time history of the ship roll shows good quantitative agreement with the experimental time history in the case of Fr = 0.138 with an angle of list of θa0 = 10°. The natural period is well estimated, there is less than 2% error. According to the time history of the roll angle and the corresponding angular velocity, the nonlinear ship roll damping and restoring force of the hull are identified by solving …

Robust Odorant Recognition In Biological And Artificial Olfaction, Nalin Katta

McKelvey School of Engineering Graduate Student Theses & Dissertations

Accurate detection and identification of gases pose a number of challenges for chemical sensory systems. The stimulus space is enormous; volatile compounds vary in size, charge, functional groups, and isomerization among others. Furthermore, variability arises from intrinsic (poisoning of the sensors or degradation due to aging) and extrinsic (environmental: humidity, temperature, flow patterns) sources. Nonetheless, biological olfactory systems have been refined over time to overcome these challenges. The main objective of this work is to understand how the biological olfactory system deals with these challenges, and translate them to artificial olfaction to achieve comparable capabilities. In particular, this thesis focuses …

Designing Metabolite Biosensors And Engineering Genetic Circuits To Regulate Metabolic Pathways, Di Liu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Microbial production of chemicals has provided an attractive alternative to chemical synthesis. A key to make this technology economically viable is to improve titers, productivities, and strain robustness. However, pathway productivities and yields are often limited by metabolic imbalances that inhibit cell growth and chemical production. In contrast, natural metabolic pathways are dynamically regulated according to cellular metabolic status. Dynamic regulation allows cells to adjust metabolite concentrations to optimal levels and avoid wasting carbon and energy. Inspired by nature, synthetic regulatory circuits have shown great promise in improving titers and productivities, because they can balance the metabolism by dynamically adjusting …

Fundamental Studies Of Flame Structure Through Laser Plasma Diagnostics, Wendong Wu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Increasing concerns about air pollution and global climate change are drawing attention to the need for efficiency improvements and emission reductions for combustion processes, which account for more than 85% of energy production in United States. Combustion efficiency and emissions are affected by the mixing and reacting of fuel and oxidizer. Understanding such behavior plays a critical role in flame structure studies and combustion optimization. However, experimentally obtaining mixture fraction, which is a widely used quantity to describe the mixing behavior, has proven to be a challenge, especially for heavier hydrocarbon fuels or fuel rich flames. Moreover, measuring flame temperature …

Mechanobiology Of Epithelial Clusters In Ecms Of Diverse Mechanical Properties, Samila Nasrollahi

McKelvey School of Engineering Graduate Student Theses & Dissertations

Cell clusters reside in complex extracellular matrices (ECMs) of varying mechanical properties. Epithelial cells sense and translate the mechanical cues presented by the surrounding ECM into biochemical signals through a process called ‘mechanotransduction’, which controls fundamental aspects of disease and development. During the course of metastasis, mechanical changes in the tumor microenvironment can lead to declustering of epithelial cells through a process called epithelial-to-mesenchymal transition (EMT). Throughout different steps of metastasis, escaped epithelial clusters encounter heterogeneous tissues of varying mechanical properties that ultimately influence their behavior in distant locations within the body. This dissertation investigates the mechanobiology of epithelial clusters …

Energy Absorbing Guardrail System, John R. Rohde, John D. Reid, King K. Mak, Dean L. Sicking

Department of Mechanical and Materials Engineering: Faculty Publications

A highway crash attenuation system having W - beam rail elements attached to a plurality of vertical posts . An impact terminal with a feeder chute guides one or more of the W - beam rail elements through the impact terminal . The feeder chute has an impact shield extending along a traffic facing side of the chute from an upstream - most end to a downstream - most end of the chute closing the traffic - facing side of the chute . The system also has an anchor cable release mechanism for releasing the cable downstream of the first …

Biofuels From Crop Residue: Soil Organic Carbon And Climate Impacts In The Us And India, Adam Liska

Adam Liska Papers

The transformation of crop residue to soil organic carbon and CO₂ is a conserved process that occurs globally. Due to the mathematics of carbon intensity calculations found in government regulations, the amount of CO₂ emitted from crop residue per unit of energy in biofuel is largely independent of the amount of residue removed and the location of its removal, as shown by results from the US and India.

Soil organic carbon (SOC) levels are at equilibria determined by carbon inputs from plant material (+I_c) and loss from oxidation to CO₂

Are the US results relevant …

Feasibility Assessment Of Substituting Stainless Steel With Aluminum Alloy For Hydraulic Gate, Kuo-Ho Chen, Tien-Kuen Huang

Journal of Marine Science and Technology–Taiwan

In this paper, the feasibility of using aluminum alloy 5083 as a replacement for currently used stainless steel SUS 304L on hydraulic gate is evaluated. Relevant properties of these two materials are compared for use in hydraulic gates. Forty common types of hydraulic gates were analyzed through the finite element program PLAXIS 3D Foundation. It shows the weight for most types of hydraulic gates with aluminum alloy 5083 is in the range of 37.6-45.9% of that of stainless steel SUS 304L. At the same time, the cost of gate manufacturing is reduced 39.6-50.5% and cost of maintanence/operation can be reduced …

Improved Analysis Of Bolted Shear Connection Under Eccentric Loads, Dung-Myau Lue, Cheng-Yen Liao, Chien-Chien Chang, Wei-Ting Hsu

Journal of Marine Science and Technology–Taiwan

Almost all bolted connections are eccentrically loaded. The American Institute of Steel Construction (AISC) permits the use of elastic and instantaneous center of rotation (IC) methods to analyze eccentric bolted connections. The elastic method normally yields relatively conservative designs and the IC method, which provides more realistic analyses, is rather complex and tedious. The current AISC manual provides tables for determining coefficient C, which is used to obtain the design strength of bolt group patterns. However, the tables provide values for only six angles of inclination (θ = 0°, 15°, 30°, 45°, 60°, and 75°). For other angles, a direct …

Comparison Of Fatty Acid Compositions And Fuel Characteristics Of Biodiesels Made From Isochrysis Galbana Lipids And From Used Cooking Oil, Cherng-Yuan Lin, Bo-Yu Lin

Journal of Marine Science and Technology–Taiwan

The fatty acid compositions and typical fuel characteristics of the biodiesels produced from Isochrysis galbana lipids and used cooking oil were analyzed and compared in this study. The experimental results showed that the major fatty acid compositions of the biodiesel made from the extracted Isochrysis galbana lipids were significantly different from those of the biodiesel made from used cooking oil. The biodiesel made from the microalgae lipids primarily comprised 35.34 wt. % myristic acid (C14:0) whereas the major compound of the used cooking-oil biodiesel was 47.51 wt. % oleic acid (C18:1). Docosahexaenoic acid (DHA) at 4.67 wt. % was only …

Mixed H2/Passivity Performances Control Of Discrete-Time Linear Stochastic Systems, Cheung-Chieh Ku, Rui-Wen Chen

Journal of Marine Science and Technology–Taiwan

A mixed performance control problem of discrete-time linear stochastic systems is discussed and investigated subject to H2 and passivity performances in this paper. Based on Itô modeling approach, stochastic systems can be represented as deterministic difference equation with multiplicative noise term. For the stochastic systems, H2 minimization problem and passivity constraint are simultaneously considered to achieve minimum output energy and attenuation performance. Applying Lyapunov theory, some sufficient conditions are derived into extended Linear Matrix Inequality (LMI) form to apply convex optimization algorithm. Moreover, a mixed H2/Passivity performance controller can be designed such that asymptotical stability and required performances of closed-loop …

An Improved Algorithm Of Trubulence Signal Denoising Based On Lms Adaptive Filtering, Xue Chen, Da-Lei Song, Xin Luan, Hua Yang, Xiu-Yan Liu

Journal of Marine Science and Technology–Taiwan

Restricted by observation instruments and methods, the measured turbulence signals in the open ocean are inevitably affected by noise. To maximum eliminate the noise caused by the vibration of the instruments and improve the accuracy of the measured turbulence signals, an improved turbulence signal denoising algorithm based on least mean square (LMS) adaptive filter is proposed in this paper. The key point of the improved algorithm is to obtain the optimal weight value by the adaptive adjustment and remove the vibration noise from the measured shear signals in frequency domain. Through taking the Nasmyth theoretical spectrum as the desired signal …

Intelligent Computation And Dsp-Based Landing Control, Jih-Gau Juang, Hou-Kai Chiou, Chia-Ling Lee

Journal of Marine Science and Technology–Taiwan

This paper presents several digital signal processor (DSP) based intelligent controllers for aircraft automatic landing systems (ALSs). Proportional-Integral-Derivative (PID) control law is adopted in the intelligent controller design. A fuzzy cerebellar model articulation controller (CMAC) is utilized to compensate for the PID control signal. Control gains are selected by evolutionary computation. The controllers' tracking performance of preset landing paths and capability to adaptively respond to different disturbances are demonstrated through hardware simulations. Different evolution methods, namely Adewuya crossover, arithmetical crossover, average crossover, convex crossover and blend crossover are utilized to analyze the controllers’ performances in terms of optimal parameter search. …

Evaluation Of Different Trading Routes On Fatigue Damage For A 216k M3 Lng Carrier, Ozgur Ozguc

Journal of Marine Science and Technology–Taiwan

This paper aims to address long term loads and fatigue damage accumulation for different trading routes relative to North Atlantic operations based on IACS scatter diagram for a 216,000 m3 LNG carrier. The evaluation is based on direct wave load analysis using WASIM and scatter diagrams created in accordance with DNV Code 30.5 for the following trades: 1. North Atlantic 2. World Wide 3. Qatar - Boston 4. Qatar - UK 5. Murmansk - Boston 6. Murmansk - Rotterdam 7. St. Petersburg - Canada 8. Sakhalin - Mexico port close to California USA 9. Sakhalin - Shanghai, China It is …

The Underwater Towed System Behavior During Ship Turning Maneuvers, Zhi-Jiang Yuan, Liang-An Jin, Wei Chi, Xiao-Gang Jiang, Zhi-Lin Zheng

Journal of Marine Science and Technology–Taiwan

The depth and attitude of underwater towed system show complex behavior during the towing ship turning maneuvers. However, it remains unclear how the two indexes change when the coupling relationship between the cable and the towed vehicle is considered. Here, to solve this issue, and we develop a new numerical method that can be used to predict the behavior of towed system during towing ship turning maneuvers. Specially, a finite difference method and six-degree-of-freedom equations are used to describe the motion of towed cable and towed vehicle respectively. Based on the center finite difference method, the partial differential equations and …

A Numerical Identification Of Excitation Force And Nonlinear Restoring Characteristics Of Ship Roll Motion, Jinsoo Park, Hong Gun Sung, Fayyaz Ahmad, Soo Hyun So, Stavros Syngellakis, Kwang Hyo Jung, Taek Soo Jang

Journal of Marine Science and Technology–Taiwan

The present work identifies the nonlinear restoring characteristics and excitation force of ship roll motion in regular beam waves. The steady-state roll response data measured from a numerical simulation is utilized for the experiments of the applied method. Using the approach proposed by Jang (2014), the J-function and its one of zero-crossing times play a crucial role in the identification. The J-function is defined to be the sum of inertia force and nonlinear damping. For the zero-crossing time to be measured, system responses of angular displacement, velocity and acceleration need to be known and so does the numerical interpolation. Numerical …

Distributed Control System For Parallel-Connected Dc Boost Converters, Steven Goldsmith

Michigan Tech Patents

The disclosed invention is a distributed control system for operating a DC bus fed by disparate DC power sources that service a known or unknown load. The voltage sources vary in v-i characteristics and have time-varying, maximum supply capacities. Each source is connected to the bus via a boost converter, which may have different dynamic characteristics and power transfer capacities, but are controlled through PWM. The invention tracks the time-varying power sources and apportions their power contribution while maintaining the DC bus voltage within the specifications. A central digital controller solves the steady-state system for the optimal duty cycle settings …

Intrinsic And Extrinsic Biomechanical Factors In A Co-Adaptive Ecog-Based Brain Computer Interface, Jonathan Carl Landes

McKelvey School of Engineering Graduate Student Theses & Dissertations

Paralysis, due to spinal cord injury, amyotrophic lateral sclerosis (ALS), or stroke, is the result of severed communication between the brain and the motor periphery. Brain computer interfaces (BCIs) are neuroprosthetic devices that create novel communication pathways by measuring and transforming neural activity into operational commands. State of the art BCI systems measure brain activity using penetrating electrode arrays able to record from hundreds of individual cortical neurons simultaneously. Unfortunately, these systems are highly susceptible to signal degradation which limits their efficacy to 1-2 years. However, electrocorticography (ECoG) signals recorded from the surface of the brain deliver a more competitive …

Efficiently And Transparently Maintaining High Simd Occupancy In The Presence Of Wavefront Irregularity, Stephen V. Cole

McKelvey School of Engineering Graduate Student Theses & Dissertations

Demand is increasing for high throughput processing of irregular streaming applications; examples of such applications from scientific and engineering domains include biological sequence alignment, network packet filtering, automated face detection, and big graph algorithms. With wide SIMD, lightweight threads, and low-cost thread-context switching, wide-SIMD architectures such as GPUs allow considerable flexibility in the way application work is assigned to threads. However, irregular applications are challenging to map efficiently onto wide SIMD because data-dependent filtering or replication of items creates an unpredictable data wavefront of items ready for further processing. Straightforward implementations of irregular applications on a wide-SIMD architecture are prone …

Parallel Real-Time Scheduling For Latency-Critical Applications, Jing Li

McKelvey School of Engineering Graduate Student Theses & Dissertations

In order to provide safety guarantees or quality of service guarantees, many of today's systems consist of latency-critical applications, e.g. applications with timing constraints. The problem of scheduling multiple latency-critical jobs on a multiprocessor or multicore machine has been extensively studied for sequential (non-parallizable) jobs and different system models and different objectives have been considered. However, the computational requirement of a single job is still limited by the capacity of a single core. To provide increasingly complex functionalities of applications and to complete their higher computational demands within the same or even more stringent timing constraints, we must exploit the …