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Articles 6451 - 6480 of 30002
Full-Text Articles in Mechanical Engineering
Integrating Temperature Dependence Into A Microstructure-Sensitive Fatigue Model For Titanium Alloys, Jared Michael Darius
Integrating Temperature Dependence Into A Microstructure-Sensitive Fatigue Model For Titanium Alloys, Jared Michael Darius
Masters Theses
This work seeks to integrate temperature dependence into a microstructure-sensitive fatigue model for titanium alloys produced by both extrusion and electron beam melting (EBM) additive manufacturing, revising and enhancing the MultiStage Fatigue (MSF) model as the foundational model framework. Traditional fatigue modeling has required design engineers to conservatively use a lower-bound estimate of fatigue life predictions given a statistically significant spread of experimental data that can span up to two or sometimes three orders of magnitude for a given test condition. This variation in fatigue data has since been accounted for with the advent of the MSF model, linking individual …
Skeletal Modeling Parameters And Clinical Factors Related To Injury Risk In Baseball Pitchers, Aaron Trunt
Skeletal Modeling Parameters And Clinical Factors Related To Injury Risk In Baseball Pitchers, Aaron Trunt
Dissertations and Theses
ABSTRACT Baseball pitching is a well-studied area of biomechanics partially due to high injury rates in the upper extremity. While current known injury risk factors for pitchers include limited shoulder range of motion (ROM), increased ball velocity, and limited shoulder strength, there has been a lack of scientific evidence linking increased joint kinetics to injury risk. The aims of this research were to (1) explore relationships between known risk factors for injury and joint kinetics, (2) establish more specific biomechanical models of pitchers to calculate joint kinetics with greater precision, and (3) deploy these models prospectively to determine how model …
A Non-Reacting Passive Scalar Comparison Of Starccm And Openfoam In A Supersonic Cavity Flame Holder, Thomas Nuese
A Non-Reacting Passive Scalar Comparison Of Starccm And Openfoam In A Supersonic Cavity Flame Holder, Thomas Nuese
Electronic Theses and Dissertations
The scramjet engine equipped with a modern-day airliner would allow for very quick travel across the United States. The major problem is that designing such an engine and testing it to make sure it is safe would cost millions if not billions of dollars. Computational fluid dynamics allows for complex designs to be tested but can still take many days, weeks, or even months to complete. With the use of computational fluid dynamics (CFD), the scramjet engine can be analyzed to determine a quicker way to test and develop a reliable configuration in addition to analyzing the effects of different …
Transdisciplinarity In Experience Design: A Global Survey Of Higher Ed Programs In Exd/Xd, Yvonne Houy
Transdisciplinarity In Experience Design: A Global Survey Of Higher Ed Programs In Exd/Xd, Yvonne Houy
Creative Collaborations
In our age of ubiquitous devices and digital media it is the perceived value of the end-to-end experience that brings people to a place. Designing inspiring and emotionally engaging end-to-end experiences requires experts in a wide range of disciplines committed to an interdisciplinary collaboration that can arrive at transdisciplinary design - the sum becomes greater than its parts.
Civil engineering, hospitality, business, psychology, digital User Experience (UX) design, and experience data analysis need to be seamless integrated with the fine and performing arts and design fields:
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Architecture, interior, landscape and sound design actively engage the senses.
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Graphic and fine arts …
Development Of Methane Emissions Model To Assess Fuel Recovery Potential At Gas Well Sites Using On Site Compression, Nicholas G. Lindenfeldar
Development Of Methane Emissions Model To Assess Fuel Recovery Potential At Gas Well Sites Using On Site Compression, Nicholas G. Lindenfeldar
Graduate Theses, Dissertations, and Problem Reports (ETD)
The US natural gas production and consumption has increased 85.5% since 2005 primarily due to the unconventional production methods of horizontal drilling and hydraulic fracturing. Natural gas used as a fuel has a lower greenhouse gas (GHG) footprint than coal and petroleum due to lower Carbon Dioxide (CO2) emissions when combusted. However, the “greener” benefit to natural gas may be consumed by leaks in production and transmission systems. Methane (CH4), the primary hydrocarbon in natural gas, has an estimated Global Warming Potential (GWP) of 28-36 over 100 years, meaning it can absorb 28-36 more energy than …
Development Of Machine Learning Algorithm To Identify High-Emitters From On-Road Data For Heavy-Duty (Hd) Vehicles, Filiz Kazan
Development Of Machine Learning Algorithm To Identify High-Emitters From On-Road Data For Heavy-Duty (Hd) Vehicles, Filiz Kazan
Graduate Theses, Dissertations, and Problem Reports (ETD)
The process of on-road, heavy-duty engine family certification is regulated by the United States Environmental Protection Agency (US EPA). Currently, the US EPA 2010 emissions standards require the threshold from the Federal Testing Procedure (FTP) engine dynamometer cycle to be at or below a brake-specific NOx (bs-NOx) value of 0.20 g/bhp-hr for heavy-duty (HD) engines. The engine manufacturers are also required to conduct in-use portable emission measurement system (PEMS) testing to prove their products' compliance. The selected vehicles are required to satisfy not-to-exceed (NTE) analysis under normal driving conditions in the heavy-duty in-use testing (HDIUT) program. California …
Computational Analysis Of The Stability Limits Of Premixed Methane-Air Combustion In Micro-Channels, Almoutazbellah Adnan Kutkut
Computational Analysis Of The Stability Limits Of Premixed Methane-Air Combustion In Micro-Channels, Almoutazbellah Adnan Kutkut
Graduate Theses, Dissertations, and Problem Reports (ETD)
Technological progress in the last decades facilitated the development of integrated microsystem devices, including electrical and mechanical components for micro-electro-mechanical systems (MEMS). Such systems necessitate an external power supply, but typical batteries yet have some unavoidable limitations. To address this problem, numerous studies have been conducted to develop alternatives powered by micro combustion – in order to effectively utilize the high-density energy of hydrocarbon fuels. Such a global need has resulted in much more attention devoted to the combustion-based micro-power generation systems. However, to better understand the typical combustion characteristics in such microscale systems, design and performance restrictions need to …
Development Of A Thermal Desalination System Using Low Quality Thermal Energy, Takudzwa C. Chipunza
Development Of A Thermal Desalination System Using Low Quality Thermal Energy, Takudzwa C. Chipunza
Graduate Theses, Dissertations, and Problem Reports (ETD)
Abstract
Development of a Thermal Desalination System Using Low Quality Thermal Energy
Takudzwa Chipunza
The blowdown water from the cooling tower of the power plant and the produced water from shale gas industry cannot be disposed directly to the environment as they may contain dissolved solids that are harmful to the environment. A detailed physical and chemical process to remove the mineral and organic solids has been developed in West Virginia University. Such a process includes running the blowdown and produced water through a softening tank, activated carbon tank, and a reverse osmosis (RO) system. The RO reject contains a …
Development Of A Machine Learning Model To Characterize The Performance Of A Selective Catalytic Reduction On Filter After-Treatment System For A Heavy-Duty Diesel Engine, Samuel A. Okeleye
Development Of A Machine Learning Model To Characterize The Performance Of A Selective Catalytic Reduction On Filter After-Treatment System For A Heavy-Duty Diesel Engine, Samuel A. Okeleye
Graduate Theses, Dissertations, and Problem Reports (ETD)
Particulate matter (PM) and Oxides of Nitrogen (NOx) are the major pollutants in diesel engines, an attempt to control one leads to an increase in the other, a phenomenon known as PM-NOx trade-off in diesel engine emission control. Currently, these two pollutants are controlled by the Diesel Particulate Filter (DPF) and the Selective Catalytic Reduction (SCR) after-treatment system respectively, in addition to the Diesel Oxidation Catalyst (DOC) which helps to provide 1:1 split of NO/NO2 and helps with raising exhaust gas temperatures. Today, heavy-duty diesel engines feature a DPF, a primary SCR and a secondary SCR. Despite this complex …
Morphologic Clustering Of Earcanals Using Deep Learning Algorithm To Design Artificial Ears Dedicated To Earplugs Attenuation Measurement, Bastien Poissenot-Arrigoni, Chun Hong Law, Djamal Berbiche, Franck Sgard, Olivier Doutres
Morphologic Clustering Of Earcanals Using Deep Learning Algorithm To Design Artificial Ears Dedicated To Earplugs Attenuation Measurement, Bastien Poissenot-Arrigoni, Chun Hong Law, Djamal Berbiche, Franck Sgard, Olivier Doutres
Études primaires
Designing earplugs adapted for the widest number of earcanals requires acoustical test fixtures (ATFs) geometrically representative of the population. Most existing ATFs are equipped with unique sized straight cylindrical earcanals, considered representative of average human morphology, and are therefore unable to assess how earplugs can fit different earcanal morphologies. In this study, a methodology to cluster earcanals as a function of their morphologies with the objective of designing artificial ears dedicated to sound attenuation measurement is developed and applied to a sample of Canadian workers’ earcanals. The earcanal morphologic indicators that correlate with the attenuations of six models of commercial …
Precise Landing Of Vtol Uavs Using A Tether, Jeremy W. Rathjen
Precise Landing Of Vtol Uavs Using A Tether, Jeremy W. Rathjen
Graduate Theses, Dissertations, and Problem Reports (ETD)
Unmanned Aerial Vehicles (UAVs), also known as drones, are often considered the solution to complex robotics problems. The significant freedom to explore an environment is a major reason why UAVs are a popular choice for automated solutions. UAVs, however, have a very limited flight time due to the low capacity and weight ratio of current batteries. One way to extend the vehicles' flight time is to use a tether to provide power from external batteries, generators on the ground, or another vehicle. Attaching a tether to a vehicle may constrain its navigation but it may also create some opportunities for …
Controlling The Thermal And Electrical Properties Of Camno3-Δ Based Perovskite Ceramics, Sergio Andres Paredes Navia
Controlling The Thermal And Electrical Properties Of Camno3-Δ Based Perovskite Ceramics, Sergio Andres Paredes Navia
Graduate Theses, Dissertations, and Problem Reports (ETD)
Most of the energy lost during the conversion process comes in the form of waste heat. The world's energy consumption loses over 60% of its energy after conversion. In order to increase the efficiency of the conversion process, it is essential to harness waste heat and reutilize this energy resource. Heat recovery technology as thermoelectric (TE) technology is one of the growing alternatives to harvest excessive amounts of energy lost as waste heat for a more efficient, safe, and sustainable future. Due to the Seebeck effect, TE materials have the potential to convert waste heat directly into electricity, improving efficiency …
Top-Down & Bottom-Up Approaches To Robot Design, Dylan Michael Covell
Top-Down & Bottom-Up Approaches To Robot Design, Dylan Michael Covell
Graduate Theses, Dissertations, and Problem Reports (ETD)
This thesis presents a study of different engineering design methodologies and demonstrates their effectiveness and limitations in actual robot designs. Some of these methods were blended together with focus on providing an easily interpreted project design flow while implementing more bottom-up, or feedback, elements into the design methodology. Typically design methods are learned through experience, and design taught in academia aims to shape and formalize previous experience. Usually, inexperienced engineers are taught approaches resembling the Verein Deutscher Ingenieure (VDI) 2221 process. This method presented by the Association of German Engineers in 2006 is regarded as the general system design process. …
Me-Em Enewsbrief, December 2021, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University
Me-Em Enewsbrief, December 2021, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University
Department of Mechanical and Aerospace Engineering eNewsBrief
No abstract provided.
Calorimetric Measurements Of Lunar Regolith Simulant And Water. An Experimental Study Correlating Weight Percent Water And Temperature Change Through Periods Of Phase Change., George B. Johnson
Dissertations, Master's Theses and Master's Reports
Permanently Shaded Regions (PSRs) are cold traps located around the lunar south pole that have been confirmed to contain possible interesting quantities or volatiles such as H2O, CO2, SO2, CH4, and others. [1] The identification of these volatiles on the lunar surface was a critical step in the development of NASA’s strategic goals for scientific discoveries, sustained space travel and exploration, and re-establishing a human presence on the moon. These volatiles are vital to the future of operating in and exploring space. The LCROSS impact revealed the existence of these resources in PSRs but more information is needed about the …
A Coupled Viscoplastic-Damage Constitutive Model For Semicrystalline Polymers, Jeffrey Wiersma
A Coupled Viscoplastic-Damage Constitutive Model For Semicrystalline Polymers, Jeffrey Wiersma
Dissertations, Master's Theses and Master's Reports
The ease of processing, recyclability, and ideal cost to weight ratio makes the semi-crystalline polymers attractive in the aerospace, automotive, and defense industries. Use of semicrystalline polymers for engineering design requires a thorough understanding of their response to mechanical deformation, rate of loading, temperature, and failure mechanisms. However, there lacks a generally agreed upon constitutive model to capture the large deformation elastic-viscoplastic response of semicrystalline polymers while incorporating the strain-rate dependence and damage behavior. To address this aspect, the objective of this dissertation is to develop an elastic-viscoplastic constitutive model to predict the rate dependent, large deformation response of semicrystalline …
Stress Analysis On Walls In Complex Fluids With Fluid-Solid Interaction, Dehong Fang
Stress Analysis On Walls In Complex Fluids With Fluid-Solid Interaction, Dehong Fang
Graduate Research Theses & Dissertations
The wall shear stress (WSS) in blood vessels influences many biological processes, such as atherosclerosis, clot growth, angiogenesis, aneurysm rupture, and blood cell transport and adhesion. The deformable red blood cells (RBCs) in blood flow make the WSS even more complex. To analyze the WSS in complex fluids with cell suspensions, numerical simulations of blood flows in simple straight channels were conducted, where the fluid-solid interactions were simulated by immersed boundary-lattice Boltzmann method. The spatiotemporal dynamics of WSS were analyzed using dynamic mode decomposition (DMD), which is a technique that can extract the low-rank spatiotemporal features from complex fluids. The …
A New Boundary Interlock Geometry Design Method For Fdm Multi-Material Part Strengthening, Shivaram Sree Venkata Shanmukha Kakaraparthi
A New Boundary Interlock Geometry Design Method For Fdm Multi-Material Part Strengthening, Shivaram Sree Venkata Shanmukha Kakaraparthi
Graduate Research Theses & Dissertations
Multi-material Fused Deposition Modelling (FDM) enables the cost-effective realization of designs in complex geometries built with multiple materials. However, achieving an adequate level of bonding strength between different materials remains a significant challenge. Besides the traditional way of addressing this challenge by strengthening material bonding at the molecular scale by optimizing the printing parameters, introducing a new design methodology that creates stronger multi-material interface geometry could also offer effective solutions. This work studied the mechanical properties of multi-material printed objects, with a particular focus on the interface zone formed between different materials at their geometrical boundaries. A new mathematical simulation …
A Parametric Study Of Thermochemical Energy Storage Using Chemical Looping For Concentrated Solar Power (Csp) Plants, Imran Anees Mohammed
A Parametric Study Of Thermochemical Energy Storage Using Chemical Looping For Concentrated Solar Power (Csp) Plants, Imran Anees Mohammed
Graduate Research Theses & Dissertations
The use of conventional fossil fuels to generate power has caused great harm to the environment. These fossil fuels, when burnt, release copious amounts of CO_2, causing global warming. Therefore, it is imperative that current energy sources are substituted with renewable energy sources. However, the critical obstacle with renewable energy sources is their intermittency. Solar energy is being captured through photovoltaic plants and concentrated solar power plants. Photovoltaic plants use batteries, which makes the storage of energy limited. Furthermore, an alternative downside is that the constant use of many batteries will considerably increaseincrease the project’s cost. Concentrated solar power plants …
Warm Unit Stand Analysis For Proton Improvement Project Ii, Michael William Pavlick
Warm Unit Stand Analysis For Proton Improvement Project Ii, Michael William Pavlick
Graduate Research Theses & Dissertations
The Proton Improvement Project II, commonly referred to as PIP II, is a linear accelerator overhaul at Fermilab to eventually double the output of its existing proton beam to continue to be the leading force in high energy physics. The proton beam is created through a series of high frequency cryomodules that must be connected utilizing a combination of magnets and vacuum pumps to ensure the beam is properly aligned. A housing mechanism for the magnets and vacuum pumps (Warm Units) will be placed between the cryomodules for realignment and require multiple stages of 6 degree-of-freedom adjustment options, to ensure …
Design And Fabrication Of A Small-Sized Omni-Directional Spherical Robot, Aayush P. Patel
Design And Fabrication Of A Small-Sized Omni-Directional Spherical Robot, Aayush P. Patel
Graduate Research Theses & Dissertations
As we have witnessed through an unprecedented pandemic crisis, a lack of or decreased level of social interactions could have a negative impact on people's mental health. Ample evidence indicates that similar phenomena take place in rodents as socially isolated rodents display a high level of stress and cognitive declination. While spherical robots have recently drawn significant interest in many areas such as education, entertainment, and surveillance due to their ability to move instantaneously in any direction, the objective of this thesis is to design and fabricate a small-sized, self-locomotive omnidirectional robot to provide those animals with physical interactions as …
Development Of Phase Change Thermal Storage Medium: Cooking With More Power And Versatility, Martin Osei
Development Of Phase Change Thermal Storage Medium: Cooking With More Power And Versatility, Martin Osei
Masters Theses
With an Insulated Solar Electric Cooker (ISEC), a 100 W solar panel directly cooks food while providing 5W off-grid electricity access; but it cooks slowly. Storing the day’s energy with phase change thermal storage allows ISEC to cook more rapidly as well as cook after sunset. The ISEC is made by sticking a 3ohm resistive to an aluminum pot (inner phase change assembly PCA) where another cooking pot fits. The resistive heater is surrounded by a bigger pot (outer PCA) that contains the PCM and is tightly sealed. The solar panel is connected to the resistive heater with a thermal …
Temperature Analysis Of A Square Lid-Driven Cavity With Particle Suspensions, Justin Kortge
Temperature Analysis Of A Square Lid-Driven Cavity With Particle Suspensions, Justin Kortge
Graduate Research Theses & Dissertations
Computational fluid dynamics (CFD) and discrete element method (DEM) are powerful tools for simulating systems that contain fluids and particles. Studies of particle fluid systems greatly vary in their applications and complexity, and yet there is a scarcity of studies focused on the thermal characteristics of the fluid. A computational analysis is conducted on two-dimensional flow in a square thermal lid-driven cavity to assess the effect of particle suspensions on the thermal characteristics of the cavity. Most studies analyzing the effect of suspensions in a thermal lid-driven cavity treat the medium as a single homogeneous nanofluid. Those that do treat …
Study Protocol To Analyze The Effects Of Posture And Exoskeleton On Human Exposure To Hand-Transmitted Vibration, Parisa Torkinejad Ziarati
Study Protocol To Analyze The Effects Of Posture And Exoskeleton On Human Exposure To Hand-Transmitted Vibration, Parisa Torkinejad Ziarati
Graduate Research Theses & Dissertations
Exposure to power hand tool-generated vibrations may lead to several health disorders collectively known as hand-arm vibration (HAV) syndromes. Power hand tools are often used in overhead postures in the manufacturing and construction industries. However, HAV risks are examined in the front-of-body posture in the existing safety standards and guidelines. Therefore, it is important to understand the effects of overhead working posture on vibration transmissibility (VT) in the upper extremities (UEs) and the spine. Secondly, there is a rising trend of using occupational exoskeletons (Exos) in the manufacturing and construction industries, especially involving overhead work with power hand tools. However, …
High Energy And Power Density Peptidoglycan Musclesthrough Super-Viscous Nanoconfined Water, Haozhen Wang, Zhi-Lun Liu, Jianpei Lao, Sheng Zhang, Rinat Abzalimov, Tong Wang, Xi Chen
High Energy And Power Density Peptidoglycan Musclesthrough Super-Viscous Nanoconfined Water, Haozhen Wang, Zhi-Lun Liu, Jianpei Lao, Sheng Zhang, Rinat Abzalimov, Tong Wang, Xi Chen
Advanced Science Research Center
Water-responsive (WR) materials that reversibly deform in response to humidity changes show great potential for developing muscle-like actuators for miniature and biomimetic robotics. Here, it is presented that Bacillus (B.) subtilis’ peptidoglycan (PG) exhibits WR actuation energy and power densities reaching 72.6 MJ m−3 and 9.1 MW m−3, respectively, orders of magnitude higher than those of frequently used actuators, such as piezoelectric actuators and dielectric elastomers. PG can deform as much as 27.2% within 110 ms, and its actuation pressure reaches ≈354.6 MPa. Surprisingly, PG exhibits an energy conversion efficiency of ≈66.8%, which can be attributed to its super-viscous nanoconfined …
Combustion Feature Characterization Using Computer Vision Diagnostics Within Rotating Detonation Combustors, Kristyn B. Johnson May
Combustion Feature Characterization Using Computer Vision Diagnostics Within Rotating Detonation Combustors, Kristyn B. Johnson May
Graduate Theses, Dissertations, and Problem Reports (ETD)
In recent years, the possibilities of higher thermodynamic efficiency and power output have led to increasing interest in the field of pressure gain combustion (PGC). Currently, a majority of PGC research is concerned with rotating detonation engines (RDEs), devices which may theoretically achieve pressure gain across the combustor. Within the RDE, detonation waves propagate continuously around a cylindrical annulus, consuming fresh fuel mixtures supplied from the base of the RDE annulus. Through constant-volume heat addition, pressure gain combustion devices theoretically achieve lower entropy generation compared to Brayton cycle combustors. RDEs are being studied for future implementation in gas turbines, where …
Development Of Oxide Dispersion Strengthening (Ods) Alloys Powder For Additive Manufacturing, Changyu Ma
Development Of Oxide Dispersion Strengthening (Ods) Alloys Powder For Additive Manufacturing, Changyu Ma
Graduate Theses, Dissertations, and Problem Reports (ETD)
Additive manufacturing (AM) fabricated oxide dispersion strengthened (ODS) alloys are given high expectations for critical structural components such as the first stage turbine blade for their excellent creep strength and oxidation resistance compared to superalloys. However, the powder feedstock processing is still an open question since current state-of-the-art processes are not capable of achieving ultrafine strengthening elements such as Y2O3 in powder which leads to agglomeration issues in as-consolidated alloys. In this research, the oxidation behavior and stability of ultrafine oxide in AM-printed alloys using mechanically alloyed powders were evaluated at 1100 oC. In addition, a …
Analysis Of Emissions Profiles Of Hydraulic Fracturing Engine Technologies, Nicholas Joseph Wells
Analysis Of Emissions Profiles Of Hydraulic Fracturing Engine Technologies, Nicholas Joseph Wells
Graduate Theses, Dissertations, and Problem Reports (ETD)
In the past twenty years natural gas production in the United States has significantly increased. This is largely due to technological advancements in unconventional methods of horizontal drilling and hydraulic fracturing. With these new and improved technologies, the United States has been able to increase its natural gas dry production per year by 14.5 trillion cubic feet per year from 2001-2021, a 74.1% increase. Horizontal drilling allows the wellbore to have more contact with the source rock, thus allowing more hydrocarbons to be extracted. Hydraulic fracturing allows oil and gas companies to have access to low permeable source rock, previously …
Development And Testing Of A Biochar Combustor For A Stirling Engine, Kyle Bryant Vickery
Development And Testing Of A Biochar Combustor For A Stirling Engine, Kyle Bryant Vickery
Graduate Theses, Dissertations, and Problem Reports (ETD)
Nonrenewable resources persist as a necessity for perpetuating the current technology and standards of living maintained throughout the world. Biochar is an alternative and renewable fuel source that constitutes the potential to provide energy comparable to coal. Designing and fabricating components that can efficiently harness biochar’s energy to power machinery would demonstrate a successful renewable energy source. The scope of this research is to explain the feasible design, fabrication, and results of technology involving the burning of biochar and transference of hot combustion products for the purpose of powering a Stirling Engine. This design consists of a solid fuel burner, …
Post-Processing Precise Point Positioning Solutions With Parameter Optimization, Maria A. Gonzalez Castaneda
Post-Processing Precise Point Positioning Solutions With Parameter Optimization, Maria A. Gonzalez Castaneda
Graduate Theses, Dissertations, and Problem Reports (ETD)
Precise Point Positioning (PPP) technique can offer position solutions with centimeter-level accuracy by fusing precise satellite orbits and clocks with un-differenced, dual-frequency, pseudo-range, and carrier-phase observables. PPP presents a compelling alternative to Differential Global Positioning Systems, with the benefit that it only requires a single receiver and does not require simultaneous observations from many stations, making it appealing for ongoing research on hydro-graphic survey applications. The National Oceanic and Atmospheric Administration has been working on a buoy system tracked with a Global Positioning Systems receiver and Inertial Measurement Unit sensor using the PPP technique. In the interest of obtaining accurate …