Engineering Commons^™

Knowledge Integration In Domain-Informed Machine Learning And Multi-Scale Modeling Of Nonlinear Dynamics In Complex Systems, Phat K. Huynh

USF Tampa Graduate Theses and Dissertations

Nonlinear dynamical systems have been extensively used to model various phenomena in the changing world around us, especially in science and engineering fields. Thanks to breakthrough advancements in sensing technologies, an increasingly high volume of multi-modal sensor data has been collected, which enables us gain better insights into complex systems dynamics and build sophisticated data-driven machine-learning-based dynamic models without having the access to the underlying governing equations. However, integrating domain-specific knowledge in machine learning algorithms remains pivotal for various reasons: it promises enhanced predictive accuracy, better model interpretability, and increased generalizability. This dissertation delves into three core research questions, each …

Analyzing Multi-Robot Leader-Follower Formations In Obstacle-Laden Environments, Zachary J. Hinnen

USF Tampa Graduate Theses and Dissertations

Observations in biological formation from nature likes flocks of birds, herds of mammals and packs of wolves have inspired the innovation of robotic architectures. This thesis presents an approach that aims to use robotic systems to mimic leader-follower behaviors in the navigation and formation of sparse and dense environments. The goal of this work is to extend and further analyze the original work of Weitzenfeld et al [3] to evaluate new swarm and pack based multi-robot architectures with the inclusion of obstacle avoidance and variations in group formations. The multiple robot architecture is based off a wolf pack with a …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Augmenting External Surface Pressures’ Predictions On Isolated Low-Rise Buildings Using Cfd Simulations, Md Faiaz Khaled, Aly Mousaad Aly

Faculty Publications

The aim of this paper is to enhance the accuracy of predicting time-averaged external surface pressures on low-rise buildings by utilizing Computational Fluid Dynamics (CFD) simulations. To achieve this, benchmark studies of the Silsoe cube and the Texas Tech University (TTU) experimental building are employed for comparison with simulation results. The paper is structured into three main sections. In the initial part, an appropriate domain size is selected based on the precision of mean pressure coefficients on the windward face of the cube, utilizing Reynolds Averaged Navier-Stokes (RANS) turbulence models. Subsequently, recommendations regarding the optimal computational domain size for an …

Gas Expansion Energy Of Coals With Different Metamorphic Degrees: Evolutionary Characteristics And Their Implications For The Outburst Prediction, Liu Gaofeng, Li Baolin, Zhang Zhen, Liu Huan, Guan Wenbo, Si Nian

Coal Geology & Exploration

To achieve an elevated accuracy in the prediction of coal and gas outbursts, this study conducted mercury injection capillary pressure (MICP) tests and isotherm adsorption experiments on selected six coal samples with different metamorphic degrees. Furthermore, it calculated the gas expansion energy of coals and analyzed the evolutionary characteristics of the gas expansion energy of coals with different metamorphic degrees, as well as their relationships with the prediction indices of coal and gas outbursts. The results of this study are as follows: (1) The differences in the pore structures and adsorptivity of coals with different metamorphic degrees led to different …

A Method For Identifying Faults Within Mining Faces Based On Spatial Statistics, Feng Yajie, Wen Guangchao, Wu Bingjie, Hu Zudong

Coal Geology & Exploration

Minor faults within mining faces of coal mines severely affect gas drainage and coal seam mining. Accurately identifying parameters such as positions, throws, and attitudes of these faults is of great significance for the safe production of coal mines. To effectively reduce gas emissions, prevent gas explosions, and exploit and utilize gas resources, many gas drainage holes have been drilled during the construction of coal mines, providing favorable engineering conditions for identifying minor faults within coal seams. Compared with the conventional fault identification methods, which rely on the expertise of geologists, the identification model based on mathematical statistics and space …

An Improved Automated Testing Model For Maceral Groups In Coals Based On Deeplabv3+, Hu Jinwei, Xi Zhenghao, Xu Guozhong, Li Zhongfeng, Liu Xiang

Coal Geology & Exploration

The identification of maceral groups in coals plays a critical role in analyzing the chemical properties of coals. However, manual identification is laborious and requires high expertise. Existing computer-assisted identification methods, mostly adopting deep learning-based semantic segmentation models, fail to accurately identify maceral groups in coals due to complex compositions of microscopic coal images and the presence of transitional components. Therefore, this study proposed an improved DeeplabV3+ semantic segmentation model integrating the Swin Transformer backbone network and the SkNet. First, to deal with the challenge of feature extraction caused by the intertwined maceral groups and the presence of transitional components …

Discovery And Generation Mechanisms Of Epigenetic Biogenic H2S From Coal Seams In The Fukang Block, Southern Junggar Basin, China, Yan Peipei, Su Xianbo, Zou Chenglong, Zhao Weizhong, Wang Lufei, Fu Haijiao

Coal Geology & Exploration

In the Fukang block located in the eastern part of the southern Junggar Basin, coalbed methane (CBM) from CBM wells exhibits a gradually increasing H₂S concentration in the process of CBM production via water drainage, severely threatening production safety. Based on the CBM exploration and extraction data, as well as the anaerobic fermentation experiments, this study preliminarily investigated the causes of abnormal H₂S concentrations during the CBM production in the Fukang block. As indicated by the gas content test in the CBM exploration stage, the original CBM showed a low H₂S concentration of only …

Water-Blocking Performance Of Laterite In Weak Deposition Areas Of Neogene Baode Formation And Its Significance Of Resource Exploitation, Zeng Yifan, Bao Han, Wu Qiang, Meng Shihao, Hua Zhaolai, Miao Yanping, Zhang Ye, Bu Wenyang

Coal Geology & Exploration

The in-depth study on the water-blocking performance of laterite in the weak deposition areas of the key aquiclude is of significant importance for mine production safety and ecological water resource protection. Specifically, the borehole data were re-optimized based on the regional sedimentary characteristics, the thickness distribution pattern of laterite deposit in Yushen mining area was studied, and the micro-engineering characteristics and control factors related to the water-blocking performance of laterite were explored. The results show that the deposition thickness of laterite gradually increases from northwest to southeast, the distribution of laterite becomes extremely uneven with the evolution of rivers, and …

Prediction Of Rockburst Intensity Grade Based On Convolutional Neural Network, Li Kangnan, Wu Yaqin, Du Feng, Zhang Xiang, Wang Yiqiao

Coal Geology & Exploration

Rockburst is one of the urgent problems to be addressed in the process of deep resource extraction. In order to predict the rockburst disasters safely and efficiently, a rockburst intensity grade prediction model (MICE-CNN) based on the Multiple Imputation by Chained Equations (MICE) and Convolutional Neural Network (CNN) was proposed. Specifically, a predictive indicator system was established based on the main influencing factors and the acquisition conditions of rockburst. A total of 120 sets of raw data from rockburst cases were collected, with the outliers processed by pauta criterion. Then, the missing data were interpolated with the four interpolation models …

Numerical Model Of Two-Region Flow By Constant-Head Pumping In An Unconfined Aquifer, Shi Pengyu, Zong Yijie, Teng Kaiqing, Liu Jianjun, Xiao Liang

Coal Geology & Exploration

In order to reveal the mechanism of two-region Darcian and non-Darcian flow induced by constant-head pumping tests in unconfined aquifers, a numerical model of well flow by constant-head pumping underground based on finite difference solution was proposed. In the model, it is assumed that the aquifer is divided into two regions according to the pumping flow characteristics: the finite non-Darcian flow region near the pumping well and the semi-infinite Darcian flow region far away from the pumping well. Specifically, the flow regime in the non-Darcian flow region was simulated by the Izbash’s equation, and the reliability of the proposed solution …

Status And Development Of Intelligent Drilling Tools For Coal Mine, Gao Xiaoliang

Coal Geology & Exploration

As an important part of intelligent drilling, the intelligence of drilling tool system plays a crucial role in the intelligent development of coal mine underground drilling. In order to deeply explore the development direction of intelligent drilling tools, the research results and technical characteristics of intelligent drilling tools in coal mines were systematically sorted out from the aspects of directional drilling tools, measurement while drilling (MWD) system, intelligent drilling pipes and drill bits with reference to the experience in development of oil and gas industry, and the existing shortcomings were also summarized. It is pointed out that screw motor is …

Breakdown Of The Drift-Diffusion Model For Transverse Spin Transport In A Disordered Pt Film, Kirill D. Belashchenko, Giovanni G. Baez Flores, Wuzhang Fang, Alexey Kovalev, Mark Van Schilfgaarde, Paul M. Haney, Mark D. Stiles

Department of Physics and Astronomy: Faculty Publications

Spin-accumulation and spin-current profiles are calculated for a disordered Pt film subjected to an in-plane electric current within the nonequilibrium Green's function approach. In the bulklike region of the sample, this approach captures the intrinsic spin Hall effect found in other calculations. Near the surfaces, the results reveal qualitative differences with the results of the widely used spin-diffusion model, even when the boundary conditions are modified to try to account for them. One difference is that the effective spin-diffusion length for transverse spin transport is significantly different from its longitudinal counterpart and is instead similar to the mean-free path. This …

Evaluation Of Equivalent Thermal Conductivity For Carbon Fiber-Reinforced Bentonite Through Experimental And Numerical Analysis, Yuan Feng, Jongwan Eun, Seunghee Kim, Yong-Rak Kim

Department of Civil and Environmental Engineering: Faculty Publications

Bentonite is widely used as a water-proof material in engineering, and fibers are added to reduce the crack development of bentonite after drying. Carbon fiber can reinforce bentonite in heat-sensitive projects because of its high thermal conductivity and potential inhibition of bentonite cracking. Thus, it is important to determine the thermal conductivity of carbon fiber-reinforced bentonite. This study evaluated the thermal conductivity of carbon fiber-reinforced bentonite by analytical solution, experiment, and finite element method (FEM) simulation and discussed the effects of carbon fiber content, fiber length, fiber distribution, and the porosity of bentonite on the thermal conductivity of reinforced bentonite. …

Methods For Estimating Carbon Emissions From Coals In Underground Mines: A Case Study Of The Western Fukang Mining Area, Peng Rendong, Wei Bo, Li Xin, Zhang Ji, Zhang Zizhao, Wang Bo, Zhang Na, Cui Deguang

Coal Geology & Exploration

Carbon emissions have come into sharp focus of human society. The carbon emissions from coals rank as the most predominant part of China’s total carbon emissions. Presently, there is no available study on the accurate calculation of carbon emissions from coals in typical underground mines in Xinjiang, with the CH₄ emission even overlooked. This study centers on the carbon emissions from coals in underground mines in the western Fukang mining area. As per the occurrence laws of CH₄ and CO₂ in coal seams, as well as coal mining plans, this study classified the sources of carbon emissions …

A New Physics-Informed Method For The Fracability Evaluation Of Shale Oil Reservoirs, Li Yuwei, Li Zijian, Shao Lifei, Tian Fuchun, Tang Jizhou

Coal Geology & Exploration

The accurate evaluation of reservoir fracability is an essential prerequisite for the fracturing design and post-fracturing productivity evaluation of reservoirs. Rock mechanical parameters have been applied to the fracability evaluation of shales presently, exhibiting great field application performance. Accordingly, it is crucial to obtain accurate rock mechanical parameters. This study developed a physics-informed neural network (PINN) model. Driven by data and physical information, the PINN model can accurately predict rock mechanical parameters using only a small amount of data. To verify its performance, the PINN model was compared with the artificial neural network, random forest, and XGBoost models. The comparison …

Water Inrush Mechanism Of Coal Mine Shaft Fracture Under Fluid-Solid Coupling, Xue Weipei, Shen Lei, Yao Zhishu, Cheng Hua, Rong Chuanxin

Coal Geology & Exploration

The occurrence of coal mine shaft fractures and water inrush accidents is alarmingly frequent, endangering the lives of underground personnel and compromising mine safety. To comprehend the influence of confined groundwater in the process of shaft fracture and the formation mechanism of water inrush channels, a model test was devised using similarity theory and coupled fluid-solid numerical simulation technology. The findings reveal that direct contact between the shaft lining and pressurized water hinders the development of load-bearing and deformation capacities. This is specifically evidenced by the premature appearance of the yield point, a reduction in peak strength and strain, and …

Zoned Prediction Of Water Inflow After Dewatering Of Working Face Based On Waterrichness Zoning Of Aquifer, Yang Lei, Lei Fangchao, Hou Enke, Lu Bo, Feng Dong, Zhao Kaixing

Coal Geology & Exploration

As the weathered bedrock and burned rock aquifers seriously threaten the production safety of mines in the Jurassic coalfield of northern Shaanxi Province, accurate prediction of their waterrichness and water inflow at the working face is of great significance for water control in mines. Aiming at the weathered bedrock and burned rock aquifers with close hydraulic connection, the area where working face 15217 of Shaanxi Hongliulin Coal Mine is located was taken as the study area. Meanwhile, the aquifer thickness, lithological combination index, index of rock burning and weathering degree and core recovery was taken as the evaluation indexes. The …

Study On Mesoscopic Failure Characteristics Of Layered Red Shale, Ma Zhenqian, Zhou Lang, Zuo Yujun, Zhang Jimin, Zou Yihuai, Cao Yunqin

Coal Geology & Exploration

To study the mesoscopic failure characteristics of the layered red shale, uniaxial mechanical experiments were carried out by applying DSTD-1000 electro-hydraulic servo rigid pressure on the red shale with different bedding angles. Meanwhile, SEM and XRD experiments were implemented on debris to obtain its mechanical parameters, failure characteristics, microstructure, and relative content of components. Based on this, models of the red shale with different bedding angles were constructed using the discrete element PFC^3D for the uniaxial compression experiments to study the mesoscopic failure characteristics of red shale. The results show that: (1) When the bedding angle θ=30°, 45°, …

An Attention Mechanism-Based Cnn-Bilstm Real-Time Transient Electromagnetic Method, Gu Yao, Xie Haijun, Zhou Zipeng, Li Lu

Coal Geology & Exploration

The one-dimensional transient electromagnetic (TEM) method is time-consuming and suffers other drawbacks such as difficult parameter adjustment and heavy dependence on the initial model. Therefore, this study proposed a real-time TEM inversion method—the Attention mechanism-based convolutional neural network (CNN) - bidirectional Long Short-Term Memory (BiLSTM) (AC-BiLSTM). By fully utilizing the time difference, the AC-BiLSTM performed model training in non-observation time and the real-time inversion of the collected data in observation time. With the measured data mixed with a certain proportion of data obtained from forward modeling as the dataset, the sampling time and apparent resistivity as the input features in …

Numerical Simulations And Wavefield Analysis Of In-Seam Wave Advance Detection In Viscoelastic Media, He Dixiu, Ji Guangzhong, Jiao Wenjie, Zhang Yawei, Yu Kun

Coal Geology & Exploration

In-seam waves are commonly applied to the advance detection of hidden faults in front of mining faces. However, coal seams, which have viscoelasticity actually, imposing absorptive and attenuation effects on in-seam waves. To investigate the wave field characteristics and propagation patterns of in-seam waves in viscoelastic coal seam media, this study built a three-dimensional geological model of coal measures with faults based on Kelvin-Voigt’s first-order velocity-stress equation. Using this equation, three-dimensional finite-difference numerical simulation was carried out. The results indicate that (1) for reflected in-seam waves in viscoelastic media, which exhibit high energy attenuation, their propagation and attenuation characteristics are …

Manipulator Trajectory Planning Method Of Anchor Drilling Robot, Lei Mengyu, Zhang Xuhui, Yang Wenjuan, Dong Zheng, Wan Jicheng, Zhang Chao, Du Yuyang

Coal Geology & Exploration

In order to improve the support efficiency of coal mine roadway and the automation intelligence of heading face, an anchor drilling robot integrating the cantilever roadheader and the six-degree-of-freedom manipulator was designed, and studied on the anchor drilling sequence planning strategy and the drilling boom trajectory planning method. Firstly, the kinematics model of the manipulator structure was established based on the improved DH method. On this basis, the forward and inverse kinematics solutions were analyzed, and the spatial position and the corresponding joint variable values of the drilling rig were calculated. Secondly, the manipulator space was analyzed based on Monte …

Characterization Of Environmental Levels Of Pesticide Residues In Household Air And Dust Samples Near A Bioenergy Plant Using Treated Seed As Feedstock, Jabeen Taiba, Eleanor G. Rogan, Daniel D. Snow, Chandran Achutan, Muhammad Zahid

Nebraska Water Center: Faculty Publications

Exposure to neonicotinoid insecticides is associated with adverse human health outcomes. There is environmental contamination in Saunders County, Nebraska, due to the accumulation of fungicides and insecticides from a now-closed ethanol plant using seed corn as stock. A pilot study quantified environmental contamination in nearby houses from residual pesticides by measuring dust and air (indoor/outdoor) concentrations of neonicotinoids and fungicides at the study site (households within two miles of the plant) and control towns (20–30 miles away). Air (SASS^® 2300 Wetted-Wall Air Sampler) and surface dust (GHOST wipes with 4 × 4-inch template) samples were collected from eleven study …

Novel Fpga Speed Grade Authentication Method For Counterfeit Identification, Ana Maria Camacho Negrete

USF Tampa Graduate Theses and Dissertations

Today's society runs on modern microelectronics. Whether it is our computers, smartphones and tablets, navigation systems, and even automobiles, the impact of inferior components on our society's functioning is a well-known and serious challenge.Inferior components, in this context, refer to non-specification compliant parts that are known to enter the global supply chain either due to manufacturing/quality control errors or intentional component counterfeiting by non-OEM (original equipment manufacturer) sources. This thesis discusses the latter, which is a well-documented and growing challenge that poses a serious risk to every sector of our society. This has been further exacerbated by the global pandemic-driven …

Structural Health Monitoring And Repair Of Welded Thermoplastic Composite Joints Using Embedded Multifunctional Films, Wencai Li

LSU Doctoral Dissertations

Thermoplastic composites (TPCs) have gained widespread use, particularly in large or integrated structural components, necessitating effective joining techniques. Fusion bonding (welding) has emerged as a suitable method for TPCs due to their ability to be reshaped through heating and cooling, eliminating the need for mechanical fasteners, long curing times, and extensive surface preparation. Among the welding techniques, ultrasonic welding (USW) stands out for its fast-cycling time and potential for automating large-scale structures, thereby reducing energy consumption. However, limited industrial applications of USW in this context require further knowledge to instill confidence in the process. Moreover, composite structures are susceptible to …

Majorana Bound States In A D-Wave Superconductor Planar Josephson Junction, Hamed Vakili, Moaz Ali, Mohamed Elekhtiar, Alexey Kovalev

Department of Physics and Astronomy: Faculty Publications

We study phase-controlled planar Josephson junctions comprising a two-dimensional electron gas with strong spin-orbit coupling and d-wave superconductors, which have an advantage of a high critical temperature. We show that a region between the two superconductors can be tuned into a topological state by the in-plane Zeeman field, and can host Majorana bound states. The phase diagram as a function of the Zeeman field, chemical potential, and the phase difference between superconductors exhibits the appearance of Majorana bound states for a wide range of parameters. We further investigate the behavior of the topological gap and its dependence on the …

An Autoencoder‑Based Snow Drought Index, Sinan Rasiya Koya, Kanak Kanti Kar, Shivendra Srivastava, Tsegaye Tadesse, Mark D. Svoboda, Tirthankar Roy

Department of Civil and Environmental Engineering: Faculty Publications

In several regions across the globe, snow has a significant impact on hydrology. The amounts of water that infiltrate the ground and flow as runoff are driven by the melting of snow. Therefore, it is crucial to study the magnitude and effect of snowmelt. Snow droughts, resulting from reduced snow storage, can drastically impact the water supplies in basins where snow predominates, such as in the western United States. Hence, it is important to detect the time and severity of snow droughts efficiently. We propose the Snow Drought Response Index or SnoDRI, a novel indicator that could be used to …

Steerable Acoustically Powered Starfish-Inspired Microrobot, Cornel Dillinger, Justin Knipper, Nitesh Nama, Daniel Ahmed

Department of Mechanical and Materials Engineering: Faculty Publications

Soft polymeric microrobots that can be loaded with nanocargoes and driven via external field stimuli can provide innovative solutions in various fields, including precise microscale assembly, targeted therapeutics, microsurgery, and the capture and degradation of unwanted wastewater fragments. However, in aquatic environments, it remains challenging to operate with microrobotic devices due to the predominant viscous resistances and the robots’ limited actuation and sensing capabilities attributed to their miniaturization. The miniature size prevents the incorporation of onboard batteries that can provide sufficient power for propulsion and navigation, necessitating a wireless power supply. Current research examines untethered microrobot manipulation using external magnetic, …

Quantifying The Effect Of Covid-19 On Port Congestion, Corey R. Mayeux

LSU Master's Theses

The Covid-19 pandemic caused unprecedented disruptions in global supply chains and port operations, leading to congestion, delays, and container shortages. Governments implemented containment measures, affecting social behavior and economic activity. Ports faced significant challenges due to shifts in demand, labor shortages, and supply chain bottlenecks. E-commerce surge and other disruptions intensified pressures on ports. The pandemic's impact exacerbated challenges for ports and supply chains, and triggered inflationary pressures. This research aims to investigate the impact of Covid-19 on port congestion and the global supply chain at the Port of Long Beach, Port of New York and New Jersey, Port of …

Effects Of Downdrag On Pile Performance, Ruthvik Pendyala

USF Tampa Graduate Theses and Dissertations

The behavior of piles under varying load conditions has sparked significant interest and research within the geotechnical engineering field. Specifically, in the context of MSE wall-type embankments, piles are installed before embankment construction commences. In these scenarios, soil settlement beneath the embankment initiates following pile installation, consequently generating downward lateral shear loads on the piles, known as downdrag.

Research pertaining to the downdrag phenomenon in cohesionless granular soils is limited. Hence, the primary focus of this study revolves around examining the impact of downdrag on pile performance in sandy soils using numerical modeling as the investigative approach. To accomplish this, …