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Spectral Absorption Coefficient Of Additive Manufacturing Materials, Nicholas J. Wallace, Matthew R. Jones, Nathan B. Crane
Spectral Absorption Coefficient Of Additive Manufacturing Materials, Nicholas J. Wallace, Matthew R. Jones, Nathan B. Crane
Faculty Publications
Active thermography techniques are of interest for quality assurance of additive manufacturing processes. However, accurate measurements of thermophysical properties of materials are required to successfully implement active thermography. In particular, the spectral absorption coefficient of materials commonly used in additive manufacturing must be known to accurately predict the spatial distribution of thermal energy generated from absorption of power emitted by a laser or pulsed flash lamp. Accurate measurements of these optical properties are also needed to develop greater understanding of additive manufacturing processes that rely on radiative heat transfer to fuse powders. This paper presents spectral absorption coefficient measurements and …
Comparing Greedy Constructive Heuristic Subtour Elimination Methods For The Traveling Salesman Problem, Petar Jackovich, Bruce A. Cox, Raymond R. Hill
Comparing Greedy Constructive Heuristic Subtour Elimination Methods For The Traveling Salesman Problem, Petar Jackovich, Bruce A. Cox, Raymond R. Hill
Faculty Publications
Purpose — This paper aims to define the class of fragment constructive heuristics used to compute feasible solutions for the traveling salesman problem (TSP) into edge-greedy and vertex-greedy subclasses. As these subclasses of heuristics can create subtours, two known methodologies for subtour elimination on symmetric instances are reviewed and are expanded to cover asymmetric problem instances. This paper introduces a third novel subtour elimination methodology, the greedy tracker (GT), and compares it to both known methodologies. Design/methodology/approach — Computational results for all three subtour elimination methodologies are generated across 17 symmetric instances ranging in size from 29 vertices to 5,934 …
Modified C-17 Taxi Procedures: A Fuel Cost Savings Exploration, Michael Wells, Michael Krester, Benjamin Hazen, Jeffrey Weir
Modified C-17 Taxi Procedures: A Fuel Cost Savings Exploration, Michael Wells, Michael Krester, Benjamin Hazen, Jeffrey Weir
Faculty Publications
Purpose — This study aims to explore the viability of using C-17 reduced-engine taxi procedures from a cost savings and capability perspective. Design/methodology/approach — This study model expected engine fuel flow based on the number of operational engines, aircraft gross weight (GW) and average aircraft groundspeed. Using this model, the research executes a cost savings simulation estimating the expected annual savings produced by the proposed taxi methodology. Operational and safety risks are also considered. Findings — The results indicate that significant fuel and costs savings are available via the employment of reduced-engine taxi procedures. On an annual basis, the mobility …
A Survey On Subsurface Signal Propagation, Usman Raza, Abdul Salam
A Survey On Subsurface Signal Propagation, Usman Raza, Abdul Salam
Faculty Publications
Wireless Underground Communication (WUC) is an emerging field that is being developed continuously. It provides secure mechanism of deploying nodes underground which shields them from any outside temperament or harsh weather conditions. This paper works towards introducing WUC and give a detail overview of WUC. It discusses system architecture of WUC along with the anatomy of the underground sensor motes deployed in WUC systems. It also compares Over-the-Air and Underground and highlights the major differences between the both type of channels. Since, UG communication is an evolving field, this paper also presents the evolution of the field along with the …
A Computational Investigation Of The Interstitial Oxidation Thermodynamics Of A Mo-Nb-Ta-W High Entropy Alloy Beyond The Dilute Regime, Adib J. Samin
A Computational Investigation Of The Interstitial Oxidation Thermodynamics Of A Mo-Nb-Ta-W High Entropy Alloy Beyond The Dilute Regime, Adib J. Samin
Faculty Publications
High entropy alloys (HEAs) are promising candidates for high-temperature structural material applications. Oxidation is a major factor that must be accounted for when designing such materials and it is thus important to study the oxidation behavior of HEAs to enable the optimum design of next generation materials. In this study, the thermodynamic behavior of interstitial oxygen in a Mo-Nb-Ta-W high entropy alloy was explored beyond the dilute limit. This was accomplished by sampling configurations of the HEA and HEA-oxygen systems from an isothermal–isobaric ensemble using a series of first-principle-based Monte Carlo simulations. It was found that the interstitial oxygen had …
Improving Tolerance Control On Modular Construction Project With 3d Laser Scanning And Bim: A Case Study Of Removable Floodwall Project, Huimin Li, Chengyi Zhang, Siyuan Song, Sevilay Demirkesen, Ruidong Chang
Improving Tolerance Control On Modular Construction Project With 3d Laser Scanning And Bim: A Case Study Of Removable Floodwall Project, Huimin Li, Chengyi Zhang, Siyuan Song, Sevilay Demirkesen, Ruidong Chang
Faculty Publications
Quality control is essential to a successful modular construction project and should be enhanced throughout the project from design to construction and installation. The current methods for analyzing the assembly quality of a removable floodwall heavily rely on manual inspection and contact-type measurements, which are time-consuming and costly. This study presents a systematic and practical approach to improve quality control of the prefabricated modular construction projects by integrating building information modeling (BIM) with three-dimensional (3D) laser scanning technology. The study starts with a thorough literature review of current quality control methods in modular construction. Firstly, the critical quality control procedure …
Noise And Detectivity Limits In Organic Shortwave Infrared Photodiodes With Low Disorder, Zhenghui Wu, Ning Li, Naresh Eedugurala, Jason D. Azoulay, Dong Seok Leem, Tse Nga Ng
Noise And Detectivity Limits In Organic Shortwave Infrared Photodiodes With Low Disorder, Zhenghui Wu, Ning Li, Naresh Eedugurala, Jason D. Azoulay, Dong Seok Leem, Tse Nga Ng
Faculty Publications
© 2020, The Author(s). To achieve high detectivity in infrared detectors, it is critical to reduce the device noise. However, for non-crystalline semiconductors, an essential framework is missing to understand and predict the effects of disorder on the dark current. This report presents experimental and modeling studies on the noise current in exemplar organic bulk heterojunction photodiodes, with 10 donor–acceptor combinations spanning wavelength between 800 and 1600 nm. A significant reduction of the noise and higher detectivity were found in devices using non-fullerene acceptors (NFAs) in comparison to those using fullerene derivatives. The low noise in NFA blends was attributed …
3-D Fabry–Pérot Cavities Sculpted On Fiber Tips Using A Multiphoton Polymerization Process, Jonathan W. Smith, Jeremiah C. Williams, Joseph S. Suelzer, Nicholas G. Usechak, Hengky Chandrahalim
3-D Fabry–Pérot Cavities Sculpted On Fiber Tips Using A Multiphoton Polymerization Process, Jonathan W. Smith, Jeremiah C. Williams, Joseph S. Suelzer, Nicholas G. Usechak, Hengky Chandrahalim
Faculty Publications
This paper presents 3-D Fabry–Pérot (FP) cavities fabricated directly onto cleaved ends of low-loss optical fibers by a two-photon polymerization (2PP) process. This fabrication technique is quick, simple, and inexpensive compared to planar microfabrication processes, which enables rapid prototyping and the ability to adapt to new requirements. These devices also utilize true 3-D design freedom, facilitating the realization of microscale optical elements with challenging geometries. Three different device types were fabricated and evaluated: an unreleased single-cavity device, a released dual-cavity device, and a released hemispherical mirror dual-cavity device. Each iteration improved the quality of the FP cavity's reflection spectrum. The …
Swarm-Based Design Of Proportional Integral And Derivative Controllers Using A Compromise Cost Function: An Arduino Temperature Laboratory Case Study, Paulo De Moura Oliveira, John Hedengren, Eduardo Solteiro Pires
Swarm-Based Design Of Proportional Integral And Derivative Controllers Using A Compromise Cost Function: An Arduino Temperature Laboratory Case Study, Paulo De Moura Oliveira, John Hedengren, Eduardo Solteiro Pires
Faculty Publications
Simple and easy to use methods are of great practical demand in the design of Proportional, Integral, and Derivative (PID) controllers. Controller design criteria are to achieve a good set-point tracking and disturbance rejection with minimal actuator variation. Achieving satisfactory trade-offs between these performance criteria is not easily accomplished with classical tuning methods. A particle swarm optimization technique is proposed to design PID controllers. The design method minimizes a compromise cost function based on both the integral absolute error and control signal total variation criteria. The proposed technique is tested on an Arduino-based Temperature Control Laboratory (TCLab) and compared with …
Writing Standards-Based Lesson Plans To Standards For Technological And Engineering Literacy, Scott Bartholomew, Thomas Loveland, Vanessa Santana
Writing Standards-Based Lesson Plans To Standards For Technological And Engineering Literacy, Scott Bartholomew, Thomas Loveland, Vanessa Santana
Faculty Publications
While written lesson plans may seem like a lot of work, with little purpose or benefit to new teachers, a well-written lesson plan is quite valuable for many reasons. The process of writing lesson plans at the beginning of one’s teaching career can be very time-consuming (Arnett-Hartwick and Cannon, 2019); however, the development of sequenced lessons that result in effective learning must be organized and articulate, not done haphazardly. Designing a lesson through a written document can help a teacher see the pattern, flow, and implications of a lesson and how it will help all students; this can be especially …
Mechanisms Of Asymmetric Membrane Formation In Nonsolvent-Induced Phase Separation, Jan Ulric Garcia, Tatsuhiro Iwama, Eva Y. Chan, Douglas R. Tree, Kris T. Delaney, Glenn H. Fredrickson
Mechanisms Of Asymmetric Membrane Formation In Nonsolvent-Induced Phase Separation, Jan Ulric Garcia, Tatsuhiro Iwama, Eva Y. Chan, Douglas R. Tree, Kris T. Delaney, Glenn H. Fredrickson
Faculty Publications
We report the first simulations of nonsolvent-induced phase separation (NIPS) that predict membrane microstructures with graded asymmetric pore size distribution. In NIPS, a polymer solution film is immersed in a nonsolvent bath, enriching the film in nonsolvent, and leading to phase separation that forms a solid polymer-rich membrane matrix and polymer-poor membrane pores. We demonstrate how mass-transfer-induced spinodal decomposition, thermal fluctuations, and glass-transition dynamics—implemented with mobility contrast between the polymer-rich and polymer-poor phases—are essential to the formation of asymmetric membrane microstructures. Specifically, we show that the competition between the propagation of the phase-separation and glass-transition fronts determines the degree of …
Cost Estimating Using A New Learning Curve Theory For Non-Constant Production Rates, Dakotah Hogan, John J. Elshaw, Clay M. Koschnick, Jonathan D. Ritschel, Adedeji B. Badiru, Shawn M. Valentine
Cost Estimating Using A New Learning Curve Theory For Non-Constant Production Rates, Dakotah Hogan, John J. Elshaw, Clay M. Koschnick, Jonathan D. Ritschel, Adedeji B. Badiru, Shawn M. Valentine
Faculty Publications
Traditional learning curve theory assumes a constant learning rate regardless of the number of units produced. However, a collection of theoretical and empirical evidence indicates that learning rates decrease as more units are produced in some cases. These diminishing learning rates cause traditional learning curves to underestimate required resources, potentially resulting in cost overruns. A diminishing learning rate model, namely Boone’s learning curve, was recently developed to model this phenomenon. This research confirms that Boone’s learning curve systematically reduced error in modeling observed learning curves using production data from 169 Department of Defense end-items. However, high amounts of variability in …
Analytical And Experimental Study Of Fatigue-Crack-Growth Ae Signals In Thin Sheet Metals, Roshan Joseph, Victor Giurgiutiu
Analytical And Experimental Study Of Fatigue-Crack-Growth Ae Signals In Thin Sheet Metals, Roshan Joseph, Victor Giurgiutiu
Faculty Publications
The acoustic emission (AE) method is a very popular and well-developed method for passive structural health monitoring of metallic and composite structures. AE method has been efficiently used for damage source detection and damage characterization in a large variety of structures over the years, such as thin sheet metals. Piezoelectric wafer active sensors (PWASs) are lightweight and inexpensive transducers, which recently drew the attention of the AE research community for AE sensing. The focus of this paper is on understanding the fatigue crack growth AE signals in thin sheet metals recorded using PWAS sensors on the basis of the Lamb …
Impact Of Sintering Time And Temperature On Mechanical Properties In Projection Sintering Of Polyamide-12, Justin Nussbaum, Taranjot Kaur, Julie Harmon, Nathan B. Crane
Impact Of Sintering Time And Temperature On Mechanical Properties In Projection Sintering Of Polyamide-12, Justin Nussbaum, Taranjot Kaur, Julie Harmon, Nathan B. Crane
Faculty Publications
In powder bed fusion additive manufacturing (AM), the fusing process is temperature and time dependent. However, little work has been done to understand how different processing temperatures and times might impact the mechanical properties at longer sintering times than are typical in laser sintering (LS) systems. Prior results with projection sintering have shown that heating for longer times (>1s) improves part toughness compared to laser sintering. In this work, Large Area Projection Sintering (LAPS) is used to sinter entire layers of material simultaneously over the course of a few seconds with spatial control of layer temperature. This work evaluates …
Secure High Der Penetration Power Distribution Via Autonomously Coordinated Volt/Var Control, Anto Joseph, Keyue Smedley, Shahab Mehraeen
Secure High Der Penetration Power Distribution Via Autonomously Coordinated Volt/Var Control, Anto Joseph, Keyue Smedley, Shahab Mehraeen
Faculty Publications
Traditionally voltage control in distribution power system (DPS) is performed through voltage regulating devices (VRDs) including on load tap changers (OLTCs), step voltage regulators (SVRs), and switched capacitor banks (SCBs). The recent IEEE 1547-2018 from March 2018 requires inverter fed distributed energy resources (DERs) to contribute reactive power to support the grid voltage. To accommodate VAR from DERs, well-organized control algorithm is required to use in this mode to avoid grid oscillations and unintended switching operations of VRDs. This paper presents two voltage control strategies (i) static voltage control considering voltage-reactive power mode (IEEE 1547-2018), (ii) dynamic and extensive voltage …
On The Recovery And Fatigue Life Extension Of Stainless Steel 316 Metals By Means Of Recovery Heat Treatment, Ali Haghshenas, M. M. Khonsari
On The Recovery And Fatigue Life Extension Of Stainless Steel 316 Metals By Means Of Recovery Heat Treatment, Ali Haghshenas, M. M. Khonsari
Faculty Publications
In this paper, we propose a methodology for enhancing the fatigue life of SS316 by performing intermittent recovery heat-treatment (RHT) in the Argon environment at different temperatures. To this end, fully-reversed fatigue bending tests are conducted on the heat-treated SS316 specimens. Damping values are obtained using the impact excitation technique to assess the damage remaining in the material after each RHT and the corresponding fatigue life. Damping is also used to distinguish the three stages of the fatigue phenomenon and the onset of crack initiation. The results show that by performing intermittent RHTs, the density of dislocation is decreased substantially …
Multihazard Hurricane Fragility Model For Wood Structure Homes Considering Hazard Parameters And Building Attributes Interaction, Carol C. Massarra, Carol J. Friedland, Brian D. Marx, J. Casey Dietrich
Multihazard Hurricane Fragility Model For Wood Structure Homes Considering Hazard Parameters And Building Attributes Interaction, Carol C. Massarra, Carol J. Friedland, Brian D. Marx, J. Casey Dietrich
Faculty Publications
Predicting building damage as a function of hurricane hazards, building attributes, and the interaction between hazard and building attributes is a key to understanding how significant interaction reflects variation hazard intensity effect on damage based on building attribute levels. This paper develops multihazard hurricane fragility models for wood structure homes considering interaction between hazard and building attributes. Fragility models are developed for ordered categorical damage states (DS) and binary collapse/no collapse. Exterior physical damage and building attributes from rapid assessment in coastal Mississippi following Hurricane Katrina (2005), high-resolution numerical hindcast hazard intensities from the Simulating WAves Nearshore and ADvanced CIRCulation …
Machine Intelligence For Nerve Conduit Design And Production, Caleb E. Stewart, Chin Fung Kelvin Kan, Brody R. Stewart, Henry W. Sanicola Iii, Jangwook P. Jung, Olawale A. R. Sulaiman, Dadong Wang
Machine Intelligence For Nerve Conduit Design And Production, Caleb E. Stewart, Chin Fung Kelvin Kan, Brody R. Stewart, Henry W. Sanicola Iii, Jangwook P. Jung, Olawale A. R. Sulaiman, Dadong Wang
Faculty Publications
Nerve guidance conduits (NGCs) have emerged from recent advances within tissue engineering as a promising alternative to autografts for peripheral nerve repair. NGCs are tubular structures with engineered biomaterials, which guide axonal regeneration from the injured proximal nerve to the distal stump. NGC design can synergistically combine multiple properties to enhance proliferation of stem and neuronal cells, improve nerve migration, attenuate inflammation and reduce scar tissue formation. The aim of most laboratories fabricating NGCs is the development of an automated process that incorporates patient-specific features and complex tissue blueprints (e.g. neurovascular conduit) that serve as the basis for more complicated …
A Statistical Impulse Response Model Based On Empirical Characterization Of Wireless Underground Channel, Abdul Salam, Mehmet C. Vuran, Suat Irmak
A Statistical Impulse Response Model Based On Empirical Characterization Of Wireless Underground Channel, Abdul Salam, Mehmet C. Vuran, Suat Irmak
Faculty Publications
Wireless underground sensor networks (WUSNs) are becoming ubiquitous in many areas. The design of robust systems requires extensive understanding of the underground (UG) channel characteristics. In this paper, an UG channel impulse response is modeled and validated via extensive experiments in indoor and field testbed settings. The three distinct types of soils are selected with sand and clay contents ranging from $13\%$ to $86\%$ and $3\%$ to $32\%$, respectively. The impacts of changes in soil texture and soil moisture are investigated with more than $1,200$ measurements in a novel UG testbed that allows flexibility in soil moisture control. Moreover, the …
Developing An Open-Source Lightweight Game Engine With Dnn Support, Haechan Park, Nakhoon Baek
Developing An Open-Source Lightweight Game Engine With Dnn Support, Haechan Park, Nakhoon Baek
Faculty Publications
With the growth of artificial intelligence and deep learning technology, we have many active research works to apply the related techniques in various fields. To test and apply the latest machine learning techniques in gaming, it will be very useful to have a light-weight game engine for quick prototyping. Our game engine is implemented in a cost-effective way, in comparison to well-known commercial proprietary game engines, by utilizing open source products. Due to its simple internal architecture, our game engine is especially beneficial for modifying and reviewing the new functions through quick and repetitive tests. In addition, the game engine …
Strategic Decision Facilitation: Supporting Critical Assumptions Of The Human In Empirical Modeling Of Pairwise Value Comparisons, Joseph P. Kristbaum, Frank W. Ciarallo
Strategic Decision Facilitation: Supporting Critical Assumptions Of The Human In Empirical Modeling Of Pairwise Value Comparisons, Joseph P. Kristbaum, Frank W. Ciarallo
Faculty Publications
Modeling human decision-making is difficult. Decision-makers are typically primed with unique biases that widen the confidence interval of judgment. Therefore, it is important that the human process in the system being modeled is designed to alleviate damaging biases and assumptions in an effort to increase process consistency between decision-makers. In this experiment, it is hypothesized that coupling specific decision-facilitation methods with a specific scale range will affect the consistency between decision-makers. This article presents a multiphase experiment that examines a varying presentation mode as well as scale range to determine how value is determined in subsequent pairwise comparisons of alternatives …
Gradient-Based Optimization Of Solar-Regenerative High-Altitude Long-Endurance Aircraft, Taylor Mcdonnell, Andrew Ning
Gradient-Based Optimization Of Solar-Regenerative High-Altitude Long-Endurance Aircraft, Taylor Mcdonnell, Andrew Ning
Faculty Publications
This paper uses gradient-based optimization to minimize the mass of a solar-regenerative high-altitude long-endurance (SR-HALE) flying-wing aircraft while accounting for nonlinear aeroelastic effects. The aircraft is designed to fly year round at 35° latitude at 18 km above sea level and subjected to energy capture, energy storage, material failure, local buckling, stall, longitudinal stability, and coupled flight and aeroelastic stability constraints. The optimized aircraft has an aspect ratio of 54.52, a surface area of 73.56 m2 , a mass of 349.5 kg, exhibits little aeroelastic deflection at the design airspeed, and is primarily stability constrained. Several parameter sweeps are performed …
Challenges To Levulinic Acid And Humins Valuation In The Sugarcane Bagasse Biorefinery Concept, Emília Savioli Lopes, Jean Felipe Leal Silva, Elmer Ccopa Rivera, Alana Petrina Gomes, Melina Savioli Lopes, Rubens Maciel Filho, Laura Plazas Tovar
Challenges To Levulinic Acid And Humins Valuation In The Sugarcane Bagasse Biorefinery Concept, Emília Savioli Lopes, Jean Felipe Leal Silva, Elmer Ccopa Rivera, Alana Petrina Gomes, Melina Savioli Lopes, Rubens Maciel Filho, Laura Plazas Tovar
Faculty Publications
© 2020, Springer Science+Business Media, LLC, part of Springer Nature. Levulinic acid (LA) is currently one of the most promising chemicals derived from biomass. However, its large-scale production is hampered by the challenges in biomass hydrolysis and the poor selectivity due to the formation of humins (HUs). This study addresses these challenges using the biorefinery concept of biomass fractionation. A three-step process (pretreatment, delignification, and acid-catalyzed conversion) was optimized to produce LA from SCB considering the yield (YLA), efficiency (ELA), and concentration of LA (CLA) as functions of temperature, reaction time, acid concentration, and solids loading. By means of a …
Nonlinear Optical Measurements Of Cdsip2 At Near And Mid-Infrared Wavelengths, Manuel R. Ferdinandus, Jamie J. Gengler, Kent L. Averett, Kevin T. Zawilski, Peter G. Schunemann, Carl M. Liebig
Nonlinear Optical Measurements Of Cdsip2 At Near And Mid-Infrared Wavelengths, Manuel R. Ferdinandus, Jamie J. Gengler, Kent L. Averett, Kevin T. Zawilski, Peter G. Schunemann, Carl M. Liebig
Faculty Publications
We measure the birefringence of the nonlinear optical (NLO) properties of cadmium silicon phosphide via the Z-scan technique at near and mid-infrared wavelengths. We discuss the implications of the NLO properties on optical parametric amplifier performance. We find that the nonlinear absorption does reduce the conversion efficiency, while the nonlinear refraction has a negligible effect.
Large-Scale Flow In Micro Electrokinetic Turbulent Mixer, Keyi Nan, Zhongyan Hu, Wei Zhao, Kaige Wang, Jintao Bai, Guiren Wang
Large-Scale Flow In Micro Electrokinetic Turbulent Mixer, Keyi Nan, Zhongyan Hu, Wei Zhao, Kaige Wang, Jintao Bai, Guiren Wang
Faculty Publications
In the present work, we studied the three-dimensional (3D) mean flow field in a micro electrokinetic (μEK) turbulence based micromixer by micro particle imaging velocimetry (μPIV) with stereoscopic method. A large-scale solenoid-type 3D mean flow field has been observed. The extraordinarily fast mixing process of the μEK turbulent mixer can be primarily attributed to two steps. First, under the strong velocity fluctuations generated by μEK mechanism, the two fluids with different conductivity are highly mixed near the entrance, primarily at the low electric conductivity sides and bias to the bottom wall. Then, the well-mixed fluid in the local region convects …
Decision Agriculture, Abdul Salam, Usman Raza
Decision Agriculture, Abdul Salam, Usman Raza
Faculty Publications
In this chapter, the latest developments in the field of decision agriculture are discussed. The practice of management zones in digital agriculture is described for efficient and smart faming. Accordingly, the methodology for delineating management zones is presented. Modeling of decision support systems is explained along with discussion of the issues and challenges in this area. Moreover, the precision agriculture technology is also considered. Moreover, the chapter surveys the state of the decision agriculture technologies in the countries such as Bulgaria, Denmark, France, Israel, Malaysia, Pakistan, United Kingdom, Ukraine, and Sweden. Finally, different field factors such as GPS accuracy and …
Electromagnetic Characteristics Of The Soil, Abdul Salam, Usman Raza
Electromagnetic Characteristics Of The Soil, Abdul Salam, Usman Raza
Faculty Publications
The electromagnetic characteristics of the soil are discussed in this chapter. The characteristics of porous bedrock, soil medium, and impacts of rain attenuations are also presented. The models of dielectric soil properties are studied with a rigorous focus on the constitutive parameters of subsurface soil medium. Moreover, the permittivity and wavenumber in soil are explained. In addition, the frequency-dependent dielectric properties such as dispersion in soil, absorption characteristic, and penetration depth versus frequency are reviewed. Furthermore, the effective permittivity of soil–water mixture for through-the soil-propagation mechanism is analyzed thoroughly.
Underground Phased Arrays And Beamforming Applications, Abdul Salam, Usman Raza
Underground Phased Arrays And Beamforming Applications, Abdul Salam, Usman Raza
Faculty Publications
This chapter presents a framework for adaptive beamforming in underground communication. The wireless propagation is thoroughly analyzed to develop a model using the soil moisture as an input parameter to provide feedback mechanism while enhancing the system performance. The working of array element in the soil is analyzed. Moreover, the effect of soil texture and soil moisture on the resonant frequency and return loss is studied in detail. The wave refraction from the soil–air interface highly degrades the performance of the system. Furthermore, to beam steering is done to achieve high gain for lateral component improving the UG communication. The …
Signals In The Soil: An Introduction To Wireless Underground Communications, Abdul Salam, Usman Raza
Signals In The Soil: An Introduction To Wireless Underground Communications, Abdul Salam, Usman Raza
Faculty Publications
In this chapter, wireless underground (UG) communications are introduced. A detailed overview of WUC is given. A comprehensive review of research challenges in WUC is presented. The evolution of underground wireless is also discussed. Moreover, different component of UG communications is wireless. The WUC system architecture is explained with a detailed discussion of the anatomy of an underground mote. The examples of UG wireless communication systems are explored. Furthermore, the differences of UG wireless and over-the-air wireless are debated. Different types of wireless underground channel (e.g., In-Soil, Soil-to-Air, and Air-to-Soil) are reported as well.
Modulation Schemes And Connectivity In Wireless Underground Channel, Abdul Salam, Usman Raza
Modulation Schemes And Connectivity In Wireless Underground Channel, Abdul Salam, Usman Raza
Faculty Publications
In this chapter, a thorough treatment of the modulation schemes for UG Wireless is presented. The effects of soil texture and water content on the capacity of multi-carrier modulation in WUC are discussed. The multi-carrier capacity model results are analyzed. Moreover, the underground MIMO design for underground communications is explained thoroughly. An analysis of medium access in wireless underground is done as well. Furthermore, the soil properties are considered for cross-layer communications of UG wireless. The performance analysis of traditional modulation schemes is also considered. The soil moisture-based modulation approach is also explored in this chapter. The connectivity and diversity …