Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Physical Sciences and Mathematics (41159)
- Civil and Environmental Engineering (40074)
- Electrical and Computer Engineering (37046)
- Mechanical Engineering (30225)
- Computer Engineering (25759)
-
- Computer Sciences (17438)
- Materials Science and Engineering (16789)
- Chemical Engineering (14252)
- Operations Research, Systems Engineering and Industrial Engineering (13938)
- Civil Engineering (11835)
- Biomedical Engineering and Bioengineering (11545)
- Aerospace Engineering (11185)
- Education (8229)
- Social and Behavioral Sciences (8050)
- Environmental Sciences (7002)
- Life Sciences (6354)
- Arts and Humanities (6254)
- Environmental Engineering (6147)
- Transportation Engineering (5938)
- Engineering Science and Materials (5755)
- Electrical and Electronics (5735)
- Energy Systems (5665)
- Artificial Intelligence and Robotics (5473)
- Other Mechanical Engineering (5100)
- Medicine and Health Sciences (4770)
- Geotechnical Engineering (4597)
- Mining Engineering (4588)
- Construction Engineering and Management (4480)
- Business (4378)
- Institution
-
- Missouri University of Science and Technology (21775)
- University of Nebraska - Lincoln (11227)
- California Polytechnic State University, San Luis Obispo (7989)
- University of Kentucky (6355)
- Purdue University (6334)
-
- Air Force Institute of Technology (5735)
- Utah State University (5449)
- Brigham Young University (4860)
- Old Dominion University (4741)
- University of Central Florida (4619)
- Technological University Dublin (4618)
- New Jersey Institute of Technology (4336)
- China Simulation Federation (3924)
- Chulalongkorn University (3655)
- Wright State University (3445)
- Embry-Riddle Aeronautical University (3311)
- University of Texas at Arlington (3184)
- TÜBİTAK (3106)
- Engineering Conferences International (2957)
- University of Arkansas, Fayetteville (2898)
- Louisiana State University (2841)
- Portland State University (2810)
- Michigan Technological University (2631)
- Clemson University (2609)
- University of South Carolina (2387)
- University of Texas at El Paso (2169)
- Marquette University (2098)
- Chinese Chemical Society | Xiamen University (2032)
- University of New Mexico (1830)
- Washington University in St. Louis (1830)
- Keyword
-
- Engineering (2868)
- Machine learning (1454)
- Optimization (1221)
- Simulation (1173)
- Applied sciences (1099)
-
- Construction (907)
- Sustainability (878)
- Design (877)
- Machine Learning (841)
- Deep learning (817)
- Modeling (749)
- Additive manufacturing (581)
- Concrete (555)
- Safety (539)
- Computer Science (535)
- Architecture (525)
- Artificial intelligence (513)
- Building (499)
- Nanoparticles (481)
- Robotics (477)
- Education (466)
- CFD (452)
- Energy (444)
- UAV (444)
- Corrosion (443)
- Engineering education (426)
- Conference (411)
- ASME (401)
- Proceedings (401)
- Mechanical Engineering (391)
- Publication Year
-
- 2026 (6002)
- 2025 (8744)
- 2024 (9335)
- 2023 (9836)
- 2022 (9398)
-
- 2021 (10038)
- 2020 (10664)
- 2019 (10525)
- 2018 (8968)
- 2017 (8369)
- 2016 (9657)
- 2015 (7568)
- 2014 (7310)
- 2013 (7343)
- 2012 (6367)
- 2011 (5885)
- 2010 (5446)
- 2009 (4191)
- 2008 (4205)
- 2007 (3835)
- 2006 (3387)
- 2005 (3064)
- 2004 (2779)
- 2003 (2069)
- 2002 (1794)
- 2001 (1791)
- 1999 (1304)
- 1998 (1355)
- 1993 (1342)
- 1991 (1362)
- Publication
-
- Theses and Dissertations (11554)
- Electronic Theses and Dissertations (4149)
- Masters Theses (3933)
- Journal of System Simulation (3924)
- Theses (3510)
-
- Electrical and Computer Engineering Faculty Research & Creative Works (3455)
- Nebraska Tractor Tests (3402)
- Faculty Publications (3279)
- Turkish Journal of Electrical Engineering and Computer Sciences (3106)
- Chulalongkorn University Theses and Dissertations (Chula ETD) (2554)
- International Conference on Case Histories in Geotechnical Engineering (2055)
- Journal of Electrochemistry (2032)
- Master's Theses (2028)
- Dissertations (1901)
- Kentucky Transportation Center Research Report (1824)
- Coal Geology & Exploration (1822)
- Doctoral Dissertations (1811)
- International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics (1566)
- USF Tampa Graduate Theses and Dissertations (1499)
- Articles (1408)
- Browse all Theses and Dissertations (1369)
- Open Access Theses & Dissertations (1323)
- Computer Science & Engineering Syllabi (1312)
- LSU Master's Theses (1312)
- Journal of Marine Science and Technology–Taiwan (1299)
- Mechanical and Aerospace Engineering Faculty Research & Creative Works (1278)
- Civil, Architectural and Environmental Engineering Faculty Research & Creative Works (1267)
- Publications (1260)
- All Theses (1247)
- Graduate Theses and Dissertations (1238)
- Publication Type
Articles 90121 - 90150 of 198163
Full-Text Articles in Engineering
3d Body Tracking Using Deep Learning, Qingguo Xu
3d Body Tracking Using Deep Learning, Qingguo Xu
Theses and Dissertations--Computer Science
This thesis introduces a 3D body tracking system based on neutral networks and 3D geometry, which can robustly estimate body poses and accurate body joints. This system takes RGB-D data as input. Body poses and joints are firstly extracted from color image using deep learning approach. The estimated joints and skeletons are further translated to 3D space by using camera calibration information. This system is running at the rate of 3 4 frames per second. It can be used to any RGB-D sensors, such as Kinect, Intel RealSense [14] or any customized system with color depth calibrated. Comparing to the …
Tunable Nanocomposite Membranes For Water Remediation And Separations, Sebastián Hernández Sierra
Tunable Nanocomposite Membranes For Water Remediation And Separations, Sebastián Hernández Sierra
Theses and Dissertations--Chemical and Materials Engineering
Nano-structured material fabrication using functionalized membranes with polyelectrolytes is a promising research field for water pollution, catalytic and mining applications. These responsive polymers react to external stimuli like temperature, pH, radiation, ionic strength or chemical composition. Such nanomaterials provide novel hybrid properties and can also be self-supported in addition to the membranes.
Polyelectrolytes (as hydrogels) have pH responsiveness. The hydrogel moieties gain or lose protons based on the pH, displaying swelling properties. These responsive materials can be exploited to synthesize metal nanoparticles in situ using their functional groups, or to immobilize other polyelectrolytes and biomolecules. Due to their properties, these …
Impact Of Climate Change On Extreme Hydrological Events In The Kentucky River Basin, Somsubhra Chattopadhyay
Impact Of Climate Change On Extreme Hydrological Events In The Kentucky River Basin, Somsubhra Chattopadhyay
Theses and Dissertations--Biosystems and Agricultural Engineering
Anthropogenic activities including urbanization, rapid industrialization, deforestation and burning of fossil fuels are broadly agreed on as primary causes for ongoing climate change. Scientists agree that climate change over the next century will continue to impact water resources with serious implications including storm surge flooding and a sea level rise projected for North America. To date, the majority of climate change studies conducted across the globe have been for large-sized watersheds; more attention is required to assess the impact of climate change on smaller watersheds, which can help to better frame sustainable water management strategies.
In the first of three …
A Portable Sensor For Measuring Gas Emissions From Dairy Compost Bedded Pack Barns, Katharine Wolf
A Portable Sensor For Measuring Gas Emissions From Dairy Compost Bedded Pack Barns, Katharine Wolf
Theses and Dissertations--Biosystems and Agricultural Engineering
The objective of this study was to develop a gas measurement chamber for the comparison of emissions from different dairy manure storage facilities. Compost bedded pack (CBP) barns are a loose housing system in which cows rest on an intensely managed compost pack. Sawdust is the primary material added to the system, along with manure and urine inputs from the cows, and the pack is stirred one to two times daily. Maintaining a high level of aerobic microbial activity in the pack is critical for cow health. Previous dairy emissions work has not included compost bedded pack barns; it was …
Fractionation And Characterization Of Lignin Streams From Genetically Engineered Switchgrass, Enshi Liu
Fractionation And Characterization Of Lignin Streams From Genetically Engineered Switchgrass, Enshi Liu
Theses and Dissertations--Biosystems and Agricultural Engineering
Development of biomass feedstocks with desirable traits for cost-effective conversion is one of the main focus areas in biofuels research. As suggested by techno-economic analyses, the success of a lignocellulose-based biorefinery largely relies on the utilization of lignin to generate value-added products, i.e. fuels and chemicals. The fate of lignin and its structural/compositional changes during pretreatment have received increasing attention; however, the effect of genetic modification on the fractionation, depolymerization and catalytic upgrading of lignin from genetically engineered plants is not well understood. This study aims to fractionate and characterize the lignin streams from a wild-type and two genetically engineered …
Relative Cross Track Error Calculations In Asabe/Iso 12188-2:2012 And Power/Energy Analysis Using A 20 Hp Tractor On A Fully Electric Drivetrain, Joseph D. Rounsaville
Relative Cross Track Error Calculations In Asabe/Iso 12188-2:2012 And Power/Energy Analysis Using A 20 Hp Tractor On A Fully Electric Drivetrain, Joseph D. Rounsaville
Theses and Dissertations--Biosystems and Agricultural Engineering
ASABE/ISO Standard 12188-2 provides test procedures for positioning and guidance systems in agricultural vehicles during straight and level travel. The standard provides excellent descriptions of test procedures, however it does not provide detail on methods to carry out the calculations necessary to calculate relative cross-track error (XTE), which is the primary measurement used to judge accuracy of the system. The standard was used to estimate the guidance accuracy of a relatively low-accuracy vehicle at 1.25 and 0.5 m s-1. At 1.25 m s-1, a nearest point calculation overestimated mean XTE by 0.8 cm, or 8.2%. The …
Using The Vehicle Routing Problem (Vrp) To Provide Logistics Solutions In Agriculture, Hasan Seyyedhasani
Using The Vehicle Routing Problem (Vrp) To Provide Logistics Solutions In Agriculture, Hasan Seyyedhasani
Theses and Dissertations--Biosystems and Agricultural Engineering
Agricultural producers consider utilizing multiple machines to reduce field completion times for improving effective field capacity. Using a number of smaller machines rather than a single big machine also has benefits such as sustainability via less compaction risk, redundancy in the event of an equipment failure, and more flexibility in machinery management. However, machinery management is complicated due to logistics issues.
In this work, the allocation and ordering of field paths among a number of available machines have been transformed into a solvable Vehicle Routing Problem (VRP). A basic heuristic algorithm (a modified form of the Clarke-Wright algorithm) and a …
Assessment Of Potential Impacts To Subsurface Bodies Of Water Due To Underground Coal Mining, Gabriel Bode-Jimenez
Assessment Of Potential Impacts To Subsurface Bodies Of Water Due To Underground Coal Mining, Gabriel Bode-Jimenez
Theses and Dissertations--Mining Engineering
Underground coal mining operations induce ground movements, which may impact overlying hydrogeologic systems. Potential impacts mainly include changes in the hydraulic conductivity of overlying strata, decreasing of the hydraulic head and changes in water flow. The present research quantifies potential hydrogeologic impacts caused by underground mining through modeling of pre- and post-mining hydrogeologic systems.
Three-dimensional conceptual hydrogeologic models were constructed with the Processing Modflow for Windows software package (PMWiN). The models are based on an actual case study, but were simplified in terms of geometry and material properties. Water flow was simulated under changing hydrogeologic properties. A number of scenarios …
Surface Chemisty Study Of Monazite Flotation In Coal Refuse Systems, Wencai Zhang
Surface Chemisty Study Of Monazite Flotation In Coal Refuse Systems, Wencai Zhang
Theses and Dissertations--Mining Engineering
Rare earth mineral recovery from alternative resources such as coal and coal byproducts is increasingly important to provide an opportunity for economic recovery from U.S. sources. Currently, China produces the majority of the 149,000 tons of rare earth elements used annually worldwide of which the U.S. imports 11% or around 16,000 tons. There are no significant mining operations producing rare earth elements in the U.S. However, there are many U.S. sources containing rare earth minerals such as monazite including heavy mineral sand and phosphate operations. Monazite mineral particles of a few microns have also been detected in Fire Clay seam …
Calculation Of The Edge Effect Offset For High Extraction Coal Panels, Joshua Hescock
Calculation Of The Edge Effect Offset For High Extraction Coal Panels, Joshua Hescock
Theses and Dissertations--Mining Engineering
The Surface Deformation Prediction System (SDPS) program has been developed as an engineering tool for the prediction of subsidence deformation indices through the implementation of an influence function. SDPS provides reliable predictions of mining induced surface displacements, strains, and tilt for varying surface topography. One of the key aspects in obtaining reliable ground deformation prediction is the determination of the edge effect offset. The value assigned to the edge effect corresponds to a virtual offsetting of boundary lines delineating the extracted panel to allow for roof cantilevering over the mined out area.
The objective of this thesis is to describe …
Fundamental Improvement In The Tribocharging Separation Process For Upgrading Coal, Jinxiang Chen
Fundamental Improvement In The Tribocharging Separation Process For Upgrading Coal, Jinxiang Chen
Theses and Dissertations--Mining Engineering
Triboelectrostatic separation is a physical separation technique that is based on surface electronic property differences among minerals to achieve a separation. Minerals have different surface conductivities and electron affinities. They are charged differently in quantity and/or polarity after a tribocharging process. Particles with different surface charges move discretely under external electric field produce a separation. Electrostatic separation is a dry mineral processing method that does not require any water or chemical reagents. It can greatly simplify the processing circuit and reduce operating cost. Additionally, problems caused by water in conventional wet mineral processing such as water freezing, dewatering, water pollution …
Target Read Operation Of Passive Ultra High Frequency Rfid Tag In A Multiple Tags Environment, Zi Qin Phua
Target Read Operation Of Passive Ultra High Frequency Rfid Tag In A Multiple Tags Environment, Zi Qin Phua
Theses and Dissertations--Mechanical and Aerospace Engineering
Passive ultra-high frequency (UHF) radio frequency Identification (RFID) has emerged as a promising solution for many industrial applications. Passive UHF systems are relatively inexpensive to implement and monitor, as no line of sight is required for the communication. There are several advantages to using a passive RFID system. For example, no internal power source is required to activate the tags, and lower labor costs and efficient multitasking operations are expected in a long term scenario. However, due to factors such as tag-to-tag interference and inaccurate localization, RFID tags that are closely spaced together are difficult to detect and program accurately …
Effect Of Interlayers On Mechanical Properties And Interfacial Stress Transfer Of 2d Layered Graphene-Polymer Nanocompsites, Colton C. Roach
Effect Of Interlayers On Mechanical Properties And Interfacial Stress Transfer Of 2d Layered Graphene-Polymer Nanocompsites, Colton C. Roach
Theses and Dissertations--Mechanical and Aerospace Engineering
Graphene, a monolayer of sp2-hybridized carbon atoms arranged in a two-dimensional (2D) lattice, is one of the most important 2D nanomaterials and has attracted tremendous attentions due to its unique geometric characteristics and exceptional mechanical properties. One of the most promising applications of this 2D nanomaterial is in polymer nanocomposites, in which the ultra-stiff, ultra-thin graphene layers function as reinforcement fillers. However, two significant questions remain to be answered: (1) whether the mechanical behaviors of 2D graphene reinforced nanocomposites can be analyzed by the convention composite theory, which is developed primarily for one-dimensional (1D) fiber-type of fillers, and …
A Physics-Based Approach To Modeling Wildland Fire Spread Through Porous Fuel Beds, Tingting Tang
A Physics-Based Approach To Modeling Wildland Fire Spread Through Porous Fuel Beds, Tingting Tang
Theses and Dissertations--Mechanical and Aerospace Engineering
Wildfires are becoming increasingly erratic nowadays at least in part because of climate change. CFD (computational fluid dynamics)-based models with the potential of simulating extreme behaviors are gaining increasing attention as a means to predict such behavior in order to aid firefighting efforts. This dissertation describes a wildfire model based on the current understanding of wildfire physics. The model includes physics of turbulence, inhomogeneous porous fuel beds, heat release, ignition, and firebrands. A discrete dynamical system for flow in porous media is derived and incorporated into the subgrid-scale model for synthetic-velocity large-eddy simulation (LES), and a general porosity-permeability model is …
Experimental Investigation Of Reading Passive Uhf Tags In A Multi-Tag Environment, Yi Zhou
Experimental Investigation Of Reading Passive Uhf Tags In A Multi-Tag Environment, Yi Zhou
Theses and Dissertations--Mechanical and Aerospace Engineering
Recently, the Internet of things (IoT) has emerged as a promising solution for several industrial applications. One of the key components in IoT is passive radio frequency identification (RFID) tags which do not require a power source for operations. Specifically, ultra-high frequency (UHF) tags are studied in this paper. However, due to factors such as tag-to-tag interference and inaccurate localization, RFID tags that are closely spaced together are difficult to detect and program accurately with unique identifiers. This thesis investigates several factors that affect the ability to encode a specific tag with unique information in the presence of other tags, …
Adaptive Scheduling For Operating Room Management, Honghan Ye
Adaptive Scheduling For Operating Room Management, Honghan Ye
Theses and Dissertations--Mechanical and Aerospace Engineering
The perioperative process in hospitals can be modelled as a 3-stage no-wait flow shop. The utilization of OR units and the average waiting time of patients are related to makespan and total completion time, respectively. However, minimizations of makespan and total completion time are NP-hard and NP-complete. Consequently, achieving good effectiveness and efficiency is a challenge in no-wait flow shop scheduling. The average idle time (AIT) and current and future idle time (CFI) heuristics are proposed to minimize makespan and total completion time, respectively. To improve effectiveness, current idle times and future idle times are taken into consideration …
The Limits & Effects Of Draw On Properties And Morphology Of Pan-Based Precursor And The Resultant Carbon Fibers, Sarah Edrington
The Limits & Effects Of Draw On Properties And Morphology Of Pan-Based Precursor And The Resultant Carbon Fibers, Sarah Edrington
Theses and Dissertations--Mechanical and Aerospace Engineering
The process, structure, and property relationship of PAN fiber as a precursor to carbon fiber was studied. The limitations of stable spinning and property improvement associated with hot draw in solution spinning were found and quantified. Conditions were varied to generated precursor fiber up to the limit of draw, from which actual samples were collected for thermal conversion to carbon fiber. Samples of PAN and subsequent carbon fiber were characterized using tensile testing and x-ray analysis. The effects of draw on modulus and break stress, as well as the orientation of the crystalline structure of both parent precursor and resultant …
Forecasting The Workload With A Hybrid Model To Reduce The Inefficiency Cost, Xinwei Pan
Forecasting The Workload With A Hybrid Model To Reduce The Inefficiency Cost, Xinwei Pan
Theses and Dissertations--Mechanical and Aerospace Engineering
Time series forecasting and modeling are challenging problems during the past decades, because of its plenty of properties and underlying correlated relationships. As a result, researchers proposed a lot of models to deal with the time series. However, the proposed models such as Autoregressive integrated moving average (ARIMA) and artificial neural networks (ANNs) only describe part of the properties of time series. In this thesis, we introduce a new hybrid model integrated filter structure to improve the prediction accuracy. Case studies with real data from University of Kentucky HealthCare are carried out to examine the superiority of our model. Also, …
Shape Memory Behavior Of Dense And Porous Niti Alloys Fabricated By Selective Laser Melting, Soheil Saedi
Shape Memory Behavior Of Dense And Porous Niti Alloys Fabricated By Selective Laser Melting, Soheil Saedi
Theses and Dissertations--Mechanical and Aerospace Engineering
Selective Laser Melting (SLM) of Additive Manufacturing is an attractive fabrication method that employs CAD data to selectively melt the metal powder layer by layer via a laser beam and produce a 3D part. This method not only opens a new window in overcoming traditional NiTi fabrication problems but also for producing porous or complex shaped structures. The combination of SLM fabrication advantages with the unique properties of NiTi alloys, such as shape memory effect, superelasticity, high ductility, work output, corrosion, biocompatibility, etc. makes SLM NiTi alloys extremely promising for numerous applications.
The SLM process parameters such as laser power, …
Computational Investigation Of Transmural Differences In Left Ventricular Contractility And Hydrogel Injection Treatment For Myocardial Infarction, Hua Wang
Theses and Dissertations--Mechanical and Aerospace Engineering
Heart failure (HF) is one of the leading causes of death and impacts millions of people throughout the world. Recently, injectable hydrogels have been developed as a potential new therapy to treat myocardium infarction (MI). This dissertation is focused on two main topics: 1) to gain a better understanding the transmural contractility in the healthy left ventricle (LV) wall and 2) investigate the efficacy of the hydrogel injection treatment on LV wall stress and function. The results indicate that a non-uniform distribution of myocardial contractility in the LV wall provide a better representation of normal LV function. The other important …
Data-Driven Adaptive Reynolds-Averaged Navier-Stokes K - Ω Models For Turbulent Flow-Field Simulations, Zhiyong Li
Data-Driven Adaptive Reynolds-Averaged Navier-Stokes K - Ω Models For Turbulent Flow-Field Simulations, Zhiyong Li
Theses and Dissertations--Mechanical and Aerospace Engineering
The data-driven adaptive algorithms are explored as a means of increasing the accuracy of Reynolds-averaged turbulence models. This dissertation presents two new data-driven adaptive computational models for simulating turbulent flow, where partial-but-incomplete measurement data is available. These models automatically adjust (i.e., adapts) the closure coefficients of the Reynolds-averaged Navier-Stokes (RANS) k-ω turbulence equations to improve agreement between the simulated flow and a set of prescribed measurement data.
The first approach is the data-driven adaptive RANS k-ω (D-DARK) model. It is validated with three canonical flow geometries: pipe flow, the backward-facing step, and flow around an airfoil. For all 3 test …
Torque Response Of Thin-Film Ferromagnetic Prisms In Uniform Magnetic Fields At Macro And Micro Scales, Soroosh Torabi
Torque Response Of Thin-Film Ferromagnetic Prisms In Uniform Magnetic Fields At Macro And Micro Scales, Soroosh Torabi
Theses and Dissertations--Mechanical and Aerospace Engineering
The non-contact nature of magnetic actuation makes it useful in a variety of microscale applications, from microfluidics and lab-on-a-chip devices to classical MEMS or even microrobotics. Ferromagnetic materials like nickel are particularly attractive, because they can be easily deposited and patterned using traditional lithography-based microscale fabrication methods. However, the response of ferromagnetic materials in a magnetic field can be difficult to predict. When placed in a magnetic field, high magnetization is induced in these ferromagnetic materials, which in turn generates force and/or torque on the ferromagnetic bodies. The magnitude and direction of these forces are highly dependent on the type …
Effects Of Temperature, Orientation, Load Level And Indenter Shape On The Indentation Response Of Niti-Based Shape Memory Alloys, Peizhen Li
Theses and Dissertations--Mechanical and Aerospace Engineering
Owing the capability of recovering large deformations through reversible phase transformation, shape memory alloys (SMAs) are well-known for their unique behaviors such as shape memory effect (SME) and superelasticity (SE), which can also be characterized by instrumented indentation techniques. Nickel titanium (NiTi) SMAs have been extensively used for nano/micro-indentation studies and widely applied to biomedical and other elaborate medical devices.
In this study, indentation responses of NiTi, NiTiHf, NiTiHfPd and NiTiHfCu alloys were investigated using spherical and Berkovich indenters at room temperature. Spherical and Berkovich indentation hardness, modulus, and work/depth recoverable ratio of these NiTi-based alloys were revealed as a …
Analytical And Boundary Element Solutions Of Bulk Reacting Lined Ducts And Parallel-Baffle Silencers, Jundong Li
Analytical And Boundary Element Solutions Of Bulk Reacting Lined Ducts And Parallel-Baffle Silencers, Jundong Li
Theses and Dissertations--Mechanical and Aerospace Engineering
Lined silencers of various configurations are used to attenuate the noise from building HVAC equipment, gas turbines, and other machinery. First-mode analytical solutions are presented for sound attenuation along rectangular lined ducts, parallel-baffle silencers, and circular lined ducts. The sound absorptive lining is treated using a bulk property model. The analytical solutions entail solving a nonlinear characteristic equation in the transverse direction after the rigid-wall boundary condition is applied. The solution is compared to the boundary element solution and a local impedance analytical solution for several test cases.
A Framework And Metrics For Sustainable Manufacturing Performance Evaluation At The Production Line, Plant And Enterprise Levels, Aihua Huang
Theses and Dissertations--Mechanical and Aerospace Engineering
Sustainable manufacturing is becoming increasingly important due to scarcity of natural resources, stricter regulations and increasing customer demand for sustainable products. Sustainable manufacturing involves the use of sustainable processes and systems to produce more sustainable products. In order to meet these demands for sustainable products, manufacturing companies have to adopt numerous strategies to achieve sustainable manufacturing. The approach for evaluating sustainable products and processes have been investigated in previous work where product/process sustainability indices were proposed. However, no comprehensive methods are available for sustainable manufacturing performance evaluation at the system level. This work aims to develop two alternate methods for …
Simulation Of Horse-Fence Contact And Interaction Affecting Rotational Falls In The Sport Of Eventing, Gregorio Robles Vega
Simulation Of Horse-Fence Contact And Interaction Affecting Rotational Falls In The Sport Of Eventing, Gregorio Robles Vega
Theses and Dissertations--Mechanical and Aerospace Engineering
Rotational falls, or somersault falls, have led to serious and fatal injuries during the cross-country phase of Eventing competitions. Research to improve the safety of the sport began in 2000 after five fatal injuries occurred in the 1999 Eventing season. These efforts led to safety devices such as air jackets, improved helmets, and frangible/deformable fences. The focus of this thesis is to develop a more complete understanding of the horse-fence interaction as the approach motion transitions to a rotational fall. To achieve this, a large distribution of inertial properties was compiled through the development of a cylinder-based inertia approximation and …
Advances In Multi-Agent Flocking: Continuous-Time And Discrete-Time Algorithms, Brandon Wellman
Advances In Multi-Agent Flocking: Continuous-Time And Discrete-Time Algorithms, Brandon Wellman
Theses and Dissertations--Mechanical and Aerospace Engineering
We present multi-agent control methods that address flocking in continuous-time and discrete-time settings. The method is decentralized, that is, each agents controller relies on local sensing to determine the relative positions and velocities of nearby agents. In the continuous-time setting, each agent has double-integrator dynamics. In the discrete-time setting, each agent has the discrete-time double-integrator dynamics obtained by sampling the continuous-time double integrator and applying a zero-order hold on the control input. We demonstrate using analysis, numerical simulations, and experimental demonstrations that agents using the flocking methods converge to flocking formations and follow the centralized leader (if applicable).
Investigation Of An Axial Flow Rotary Valve Seal, Joseph K. Stieha
Investigation Of An Axial Flow Rotary Valve Seal, Joseph K. Stieha
Theses and Dissertations--Mechanical and Aerospace Engineering
This thesis investigates potential materials to be used in the rotary sealing industry that provide low power loss and minimize cost. The studied rotary valve utilizes slots that act as timing valves to allow for flow axially, through the seal face, at particular times within a heat pump cycle. This investigation examines various combinations of multiple PTFE materials, plastics, and soft metals that have been proven to provide low friction coefficients. Leakage and wear requirements are stated for the future use of the rotary valve and are used to determine the effectiveness of sealing the fluid while examining the power …
Development Of A Supplier Segmentation Method For Increased Resilience And Robustness: A Study Using Agent Based Modeling And Simulation, Adam J. Brown
Theses and Dissertations--Mechanical and Aerospace Engineering
Supply chain management is a complex process requiring the coordination of numerous decisions in the attempt to balance often-conflicting objectives such as quality, cost, and on-time delivery. To meet these and other objectives, a focal company must develop organized systems for establishing and managing its supplier relationships. A reliable, decision-support tool is needed for selecting the best procurement strategy for each supplier, given knowledge of the existing sourcing environment. Supplier segmentation is a well-established and resource-efficient tool used to identify procurement strategies for groups of suppliers with similar characteristics. However, the existing methods of segmentation generally select strategies that optimize …
Impedance-To-Scattering Matrix Method For Large Silencer Analysis, Peng Wang
Impedance-To-Scattering Matrix Method For Large Silencer Analysis, Peng Wang
Theses and Dissertations--Mechanical and Aerospace Engineering
Large silencers used in the power generation industry usually have a very large cross section at the inlet and outlet. Higher-order modes will populate the inlet and outlet even at very low frequencies. Although the silencer itself is often modeled by a three-dimensional analysis tool such as the boundary element method (BEM) or finite element method (FEM), a direct computation of the transmission loss (TL) from the BEM or FEM model can be challenging without incorporating certain forms of modal expansion.
A so-called “impedance-to-scattering matrix method” is proposed to extract the modes at the inlet and outlet from the BEM …