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2019

Theses/Dissertations

Iowa State University

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Articles 1 - 30 of 103

Full-Text Articles in Engineering

Graphene Humidity Sensor With Gold Nanoparticles, Jiawei Bao Jan 2019

Graphene Humidity Sensor With Gold Nanoparticles, Jiawei Bao

Graduate Theses and Dissertations

Humidity sensors can be used to monitor body sweat. Here, we studied a humidity sensor that comprised of a graphene layer between two electrodes. The operating principle is that the humidity sensor will respond when vapor reaches the graphene layer from the top. Based on the humidity diffusion, the sensor measures the relative humidity (RH) with different response times. Graphene is a material with high diffusivity and small thickness that can increase the sensitivity of a sensor. Based on the Micro Electro Mechanical Systems (MEMS) method, we modeled the humidity sensor using COMSOL Multiphysics transport of diluted species software. Finally ...


Interdisciplinary Research Into Architecture And Music: An Evaluation Of Acoustic Performance Of A Selection Of Spaces And Of Materials, Boram Kim Jan 2019

Interdisciplinary Research Into Architecture And Music: An Evaluation Of Acoustic Performance Of A Selection Of Spaces And Of Materials, Boram Kim

Graduate Theses and Dissertations

This research examines the acoustic comforts of different occupational building types and investigates the combination of building elements, especially focusing on building layout and materials that are considered significant sources of unwanted sound. A major part of the thesis relies on a series of sound pressure (decibel) measurements in three distinctive occupational types: residential, educational, and theater buildings on the Iowa State University campus, and evaluates them with the current standard of allowable sound levels. In addition, this thesis analyzes the existing spatial and material strategies of the three types. The selected materials and their acoustic qualities will be investigated ...


Electrical Sensor Development For The Dielectric Properties Measurement And Moisture Content Estimation Of Switchgrass And Corn Stover, Augusto Cesar Magalhaes De Souza Jan 2019

Electrical Sensor Development For The Dielectric Properties Measurement And Moisture Content Estimation Of Switchgrass And Corn Stover, Augusto Cesar Magalhaes De Souza

Graduate Theses and Dissertations

The dielectric properties of material play a relevant role when developing moisture content sensors of agricultural products. However, little is known about the permittivity of switchgrass and corn stover in a wider frequency band. Thus, this research goal was to determine their dielectric constant and loss factor at different moisture contents and frequency range of 5 Hz to 13 MHz. Also, an electrical sensor system was developed to predict the amount of water in agricultural products with the material static and in movement.

The dielectric properties of switchgrass and corn stover were calculated by measuring their admittance using an impedance ...


Nanostructured Surfaces Fabricated By Modified Interference Lithographic Technique For Modulation Of Interfacial Processes, Russell Mahmood Jan 2019

Nanostructured Surfaces Fabricated By Modified Interference Lithographic Technique For Modulation Of Interfacial Processes, Russell Mahmood

Graduate Theses and Dissertations

The focus of this dissertation is two-pronged: 1. Extending the capability of laser interference lithographic technique to fabricate novel nanostructured surfaces and 2. Application of the fabricated nanostructured surfaces to modulate interfacial processes, e.g. coupling of light with metallic nanostructures to excite surface plasmon resonance (SPR) and directing self-assembly of colloidal crystals.

The first part of the dissertation focuses on modifying the laser interference lithography (LIL) technique. The traditional LIL is limited to fabrication of only single-pitch linear gratings. We mitigated this drawback by incorporating non-planar Lloyds mirror to the LIL technique. The proposed modified LIL technique has the ...


Evaluating Boom Height Control Performance With Variable Boom Roll Damping In A Suspended Boom System On Self-Propelled Sprayers, Evan Mellott Jan 2019

Evaluating Boom Height Control Performance With Variable Boom Roll Damping In A Suspended Boom System On Self-Propelled Sprayers, Evan Mellott

Graduate Theses and Dissertations

In this research, a method for improving spray boom height stability was developed and tested. Self-propelled sprayers played a critical role in agriculture by applying chemicals to crops to control the presence of weeds and pests. The spraying process needed to be controlled in a manner such that the spray boom maintained the necessary target height for uniform coverage. Deviation from target height allowed outside factors such as wind to become more prevalent during chemical application which generated opportunities for spray drift to occur and potentially harm neighboring crops and environment.

On a suspended spray boom system, terrain influences on ...


Provable Algorithms For Nonlinear Models In Machine Learning And Signal Processing, Mohammadreza Soltani Jan 2019

Provable Algorithms For Nonlinear Models In Machine Learning And Signal Processing, Mohammadreza Soltani

Graduate Theses and Dissertations

In numerous signal processing and machine learning applications, the problem of signal recovery from a limited number of nonlinear observations is of special interest.

These problems also called inverse problem have recently received attention in signal processing, machine learning, and high-dimensional statistics. In high-dimensional setting, the inverse problems are inherently ill-posed as the number of measurements is typically less than the number of dimensions. As a result, one needs to assume some structures on the underlying signal such as sparsity, structured sparsity, low-rank and so on. In addition, having a nonlinear map from the signal space to the measurement space ...


Portable Water Filled Barrier With Internal Honeycomb Cells, Zhe Wang Jan 2019

Portable Water Filled Barrier With Internal Honeycomb Cells, Zhe Wang

Graduate Theses and Dissertations

Longitudinal traffic barriers are widely used as road safety features in the

United States to keep vehicles within the roadway and prevent them from colliding

with dangerous obstacles. Portable water-filled barriers (PWFBs) are one type of

temporary longitudinal traffic barriers, commonly used in speed limit zones and,

roadside working zones. Current market PWFBs are cost-effective and exhibiting

high efficiency while resisting vehicle impact at low speed. However, high-level

impact severity results in structural failure and extensive lateral deflection. Based on

evaluation criteria from Manual of Assessing Safety Hardware (MASH), some

PWFBs are inefficient to meet the requirements from newly published ...


Asymptotic Analysis Of Hypersonic Boundary Layers Over An Adiabatic Wall With Deformations, Sampson Davis Jan 2019

Asymptotic Analysis Of Hypersonic Boundary Layers Over An Adiabatic Wall With Deformations, Sampson Davis

Graduate Theses and Dissertations

Following the achievement of a man made vehicle attaining hypersonic speeds in the late 1940's, hypersonic flow quickly became a field great interest. Early on, in the 50's and 60's, analytic methods for hypersonic flow were developed by early pioneers of the field, but by the late 60's and into the 70's these methods began to be overshadowed by CFD methods. By this time CFD had become sufficiently powerful and commercially available such that they became the more attractive option and have since become the dominate method of study for high mach flows. Though the ...


Hirepro: Aiding “Aging In Place” Via Connecting Caregiver To Older Adults Through Web Application, Vikas Jyoty Jan 2019

Hirepro: Aiding “Aging In Place” Via Connecting Caregiver To Older Adults Through Web Application, Vikas Jyoty

Creative Components

Our innovation addresses three main problems. First, our innovation is addressing the concept of “aging in place”, or older adults living independently in their own home. Our innovation is focusing on this problem so that older adults will be able to live independently in their homes for a longer period and maintain autonomy, while ensuring a safe environment. Second, this product addresses the issues that service providers face in delivering high quality services and care to older adults, such as staffing and identifying care recipients in need. Third, family members often provide informal care for older adults. However, due to ...


Simulating Severe Supply Chain Disruptions With Multiple Suppliers And Firms, Kevin Korniejczuk Jan 2019

Simulating Severe Supply Chain Disruptions With Multiple Suppliers And Firms, Kevin Korniejczuk

Creative Components

Global supply chains are susceptible to disruptions. Disruptions in one part of the world can lead to supply chain problems for companies around the world. This creative component analyzes a model of severe supply chain disruptions where several suppliers encounter inoperable facilities, resulting in potential shortages for firms which purchase from those suppliers. All entities within the model are able to choose strategic initiatives to maintain operations. If an entity’s facility is closed because of a disruptive event, the entity can choose to move production to an alternate facility. If an entity’s facility is undamaged, the entity can ...


Evaluation Of Earthquake Hazard Of Hongshanzhuang Bridge In Jinghu High-Speed Railway, Chao Ma Jan 2019

Evaluation Of Earthquake Hazard Of Hongshanzhuang Bridge In Jinghu High-Speed Railway, Chao Ma

Creative Components

No abstract provided.


Upgrades To Iseflow: Offloading Arp And Supporting Ipv6, Joel May Jan 2019

Upgrades To Iseflow: Offloading Arp And Supporting Ipv6, Joel May

Creative Components

No abstract provided.


Suppression Of Wingtip Vortices Using Plasma Flow Control, Eric Harper Jan 2019

Suppression Of Wingtip Vortices Using Plasma Flow Control, Eric Harper

Creative Components

An attempt to use Alternating Current Dielectric-Barrier-Discharge actuators to suppress wingtip vortex of a finite wing. A NACA 0012 wing with AC-DBD actuators embedded at the wingtip was used at a Reynolds number of approximately 150,000. A stereoscopic PIV system measured the wake at multiple distances behind the trailing edge. A JR3 multi-axis load cell was used to simultaneously measure the forces on the wing. The angle between the AC-DBD actuators and U changed to determine any impact on the wingtip vortex. Repeated efforts lead to the conclusion that the AC-DBD actuators were too weak to have an observable ...


Assessing Coexistence Of Ieee 802.15.4 Networks And Ieee 802.11b/G/N Networks - A Study Of Interference Effects, Resy Verma Jan 2019

Assessing Coexistence Of Ieee 802.15.4 Networks And Ieee 802.11b/G/N Networks - A Study Of Interference Effects, Resy Verma

Creative Components

The study of the coexistence capabilities of networks based on the IEEE 802.11 and IEEE 802.15.4 standards has long been of interest to researchers owing to the individual success of these two technologies in various applications of Internet of Things (IoT). Operating in the same Industrial-Scientific-Medical (ISM) band, their coexistence does not always yield satisfactory results. The performance of a network based on IEEE 802.15.4 standard has been shown to be significantly lowered in the presence of a strong IEEE 802.11 based network (Wireless LAN) to the extent that communication based on the IEEE ...


Subspace Tracking From Missing And Corrupted Data Using Norst And Its Heuristic Extensions, Vahid Daneshpajooh Jan 2019

Subspace Tracking From Missing And Corrupted Data Using Norst And Its Heuristic Extensions, Vahid Daneshpajooh

Creative Components

We study the problem of subspace tracking (ST) in the presence of missing and corrupted data. We are able to show that, under assumptions on only the algorithm inputs (input data and/or initialization), the output subspace estimates are close to the true data subspaces at all times. The guarantees hold under mild and easily interpretable assumptions and handle time-varying subspaces. We also show that our algorithm and its extensions are fast and have competitive experimental performance when compared with existing methods. Finally, this solution can be interpreted as a provably correct mini-batch and memory-efficient solution to low rank Matrix ...


Evaluation Of Cnn Models With Fashion Mnist Data, Yue Zhang Jan 2019

Evaluation Of Cnn Models With Fashion Mnist Data, Yue Zhang

Creative Components

The work seeks to evaluate the performance of four CNNs with respect to Fashion MNIST data set. Fashion MNIST is a dataset of images consisting of 70000 28*28 grayscale images, associated with a label from 10 classes. In this report, the accuracy of four popular CNN models that are LeNet-5, AlexNet, VGG-16 and ResNet for classifying MNIST-fashion data revealed that ResNet was the best suited for the selected dataset. The training process has been coded with Tensorflow. After the result accuracy improving, we could use the new model to the fashion company that can help the fashion company more ...


Impact Of Soybean Derived Chemical Additive On The Morphology Of Asphaltenes Extracted From Virgin Asphalt, Polymer Modified Asphalt And Recycled Asphalt Pavement Extracted Binder Through Small-Angle X-Ray Scattering By Solids And Solids In Solution, Barrie Yung Ming Saw, Joseph H. Podolsky, Zahra Sotoodeh Nia, Nacu Hernandez, Benjamin Empric, Michael Forrester, Fang-Yi Lin, Eric W. Cochran, R. Christopher Williams Jan 2019

Impact Of Soybean Derived Chemical Additive On The Morphology Of Asphaltenes Extracted From Virgin Asphalt, Polymer Modified Asphalt And Recycled Asphalt Pavement Extracted Binder Through Small-Angle X-Ray Scattering By Solids And Solids In Solution, Barrie Yung Ming Saw, Joseph H. Podolsky, Zahra Sotoodeh Nia, Nacu Hernandez, Benjamin Empric, Michael Forrester, Fang-Yi Lin, Eric W. Cochran, R. Christopher Williams

Creative Components

Recent work has shown that epoxidized plant oil materials work well as rejuvenators in recycled asphalt pavement (RAP). At the end of the 2017 construction season, a field trial mix with 30% RAP (total recycled binder content of 30.3%) was produced and placed in Northwest Iowa on US-18, east of Sheldon, Iowa. The rejuvenator (SR) was used at a rate of 0.125% by total mix weight. The mix design for the control section used a PG 58-34H. Due to Iowa DOT specification (recycled binder content greater than 20%) a grade bump was needed for the binder in the ...


Ads Searching Service, Ming Wu Jan 2019

Ads Searching Service, Ming Wu

Creative Components

No abstract provided.


Evaluation Of Antenna Design And Energy Harvesting System Of Passive Tag In Uhf Rfid Applications, Chengrui Yang Jan 2019

Evaluation Of Antenna Design And Energy Harvesting System Of Passive Tag In Uhf Rfid Applications, Chengrui Yang

Creative Components

Backscattering communication-based Radio Frequency Identification (RFID) has been essential to the rapid advancement of IoT devices. However, most RFID applications only utilize relatively simple antenna designs. This work contributes in two ways: we investigate the impact of different antenna configurations on a passive network using backscattering technology. In addition, we evaluate the designs of power harvesting technologies valid for Ultra-High-Frequency (UHF) RFID applications. Our evaluations demonstrate that tailored antenna designs can more efficiently achieve application requirements when compared to a simple universal antenna. In addition, we give recommendations on energy harvesters for applications operating in different scenarios.


Deep Learning For Image Classification On Very Small Datasets Using Transfer Learning, Mengying Shu Jan 2019

Deep Learning For Image Classification On Very Small Datasets Using Transfer Learning, Mengying Shu

Creative Components

Since the ImageNet Large Scale Visual Recognition Challenge has been run annually from 2010 to present, researchers have designed lots of brilliant deep convolutional neural networks(D-CNNs). However, most of the existing deep convolutional neural networks are trained with large datasets. It is rare for small datasets to take advantage of deep convolutional neural networks because of overfitting when implementing those models. In this report, I propose a modified deep neural network and use this model to fit a small size dataset. The goal of my work is to show that a proper modified very deep model pre-trained on ImageNet ...


A Brief Literature Review On Recent Progress In Nanopore Thin Film-Based Optical Sensors, Guantong Zhou Jan 2019

A Brief Literature Review On Recent Progress In Nanopore Thin Film-Based Optical Sensors, Guantong Zhou

Creative Components

Anodic aluminum oxide (AAO) material is broadly used in biomedical and biosensing applications nowadays. Most of the AAO nanopore thin film sensors are usually fabricated on a glass substrate. By bonding the AAO nanopore thin film sensors to a layer of transparent polymer thin film (pTF) made with polydimethylsiloxane (PDMS), a new type of flexible nanopore sensors has been developed. The AAO thin film based flexible sensing platform has been used for pressure sensing, temperature sensing, angular sensing, and for disease biomarker detection. This short review will summarize some recent progress using the AAO nanopore thin film as the drug ...


Feature-Rich Models And Feature Reduction For Malicious Urls Classification And Prediction, Shivika Garg Jan 2019

Feature-Rich Models And Feature Reduction For Malicious Urls Classification And Prediction, Shivika Garg

Creative Components

Malicious web site is a foundation of criminal activities on Internet. This links enables partial or full machine control to the attackers. This results in victim systems, which get easily infected allowing attackers to utilize systems for quite a number of cyber-crimes such as stealing credentials, spamming, phishing, denial-of-service and many extra such attacks. Therefore, the methodology and technique to detect such crimes should be fast and precise with the additional capability to detect new malicious websites or content. This paper introduces an automatic tool to extract 110 significant features for a URL. Additionally, this paper also propose various aspects ...


Multimodality Assistive Technology For Users With Dyslexia, Shira Gordon Jan 2019

Multimodality Assistive Technology For Users With Dyslexia, Shira Gordon

Creative Components

To assist dyslexic users with reading and writing, several approaches have been explored to convey text to users using text-to-speech technology (TTS), and to transcribe what the user dictates using speech-to-text technology (STT). The currently available assistive technologies suffer from limitations around compatibility with digital-only formats, and the necessity for speaking out loud to use speech synthesis, and dictation out loud, thus creating social stigmas. If we think beyond singular modal solutions and expand the possibilities to include solutions that are multimodal and multisensory, it opens up the door for creative ways to help people with dyslexia. An alternate approach ...


Implementation Of Image Quality Assessment Algorithms For Descriptive Statistics And Deep Learning On Stegoappdb, Venkata Bhanu Chowdary Allada Jan 2019

Implementation Of Image Quality Assessment Algorithms For Descriptive Statistics And Deep Learning On Stegoappdb, Venkata Bhanu Chowdary Allada

Creative Components

No abstract provided.


Self-Configured Elastic Database With Deep Q-Learning Approach, Yifu Zhou Jan 2019

Self-Configured Elastic Database With Deep Q-Learning Approach, Yifu Zhou

Creative Components

Elastic databases have grown in popularity over conventional databases in recent years due to their ability to be allocated with sufficient capacity for peak load. Especially with the support of the cloud platform, which provides flexible resources and low cost, elastic databases on the cloud show their excellent potential in scalability, flexibility, and accessibility. However, the interaction between the cloud layers of virtual machines (VMs) and databases further complicates the issue of cloud configuration to adapt to dynamic workloads. In this paper, I explore a framework for a self-configured elastic database that can optimize the cloud configuration and adaptively allocate ...


Persitent Memory Test Framework, Caleb Toney Jan 2019

Persitent Memory Test Framework, Caleb Toney

Creative Components

This creative component introduces a trace based testing framework for persistent memory programs. Using a number of tools and techniques, the framework checks for expected output, hangs, and errors. The framework builds on the ideas put forth in previous persistent memory testing frameworks and could be the base of a full featured test framework in the future. The framework introduces a trace generator, memory map generator, and bug checker in conjunction with a program that recovers from power failures by accessing persistent memory. We show that the framework is able to detect synthetic hangs and recovery code errors.


Security Analysis Of Vehicle To Vehicle Arada Locomate On Board Unit, Ramanni J Veeraraghava Jan 2019

Security Analysis Of Vehicle To Vehicle Arada Locomate On Board Unit, Ramanni J Veeraraghava

Creative Components

Arada Locomate On-Board Unit is a vehicle-to-vehicle communication device that supports the WAVE protocol, which is the standard for vehicle to vehicle communication. Successful attacks on the device could be used to control the behavior of the connected vehicle. This creative component assesses the security of the device and discusses the vulnerabilities of the applications installed on the device. It reports about our results to exploit the known vulnerabilities of Dropbear ssh, Busybox telnet, and the Linux kernel, which are installed on the device and discusses how to obtain the private keys of the device to use them for attacks ...


Android Third-Party Library Detection, Brody Concannon Jan 2019

Android Third-Party Library Detection, Brody Concannon

Creative Components

Third-party library analysis research is important to many research fields like program analysis, clone-detection, security and privacy. There are many considerations taken when developing a third-party library analysis approach. The approach must be resilient to common obfuscation techniques and be able to determine similarity between two libraries with a high level of confidence. This paper explores this research and the problems that have been solved and reviews the improvements and shortcomings within the third-party library analysis field.


A Configurable General Purpose Graphics Processing Unit For Power, Performance, And Area Analysis, Garrett Lies Jan 2019

A Configurable General Purpose Graphics Processing Unit For Power, Performance, And Area Analysis, Garrett Lies

Creative Components

No abstract provided.


Abnormality Management In Spatial Crowdsourcing For Multi-Skilled Workers Assignment, Srinandan Kota Jan 2019

Abnormality Management In Spatial Crowdsourcing For Multi-Skilled Workers Assignment, Srinandan Kota

Creative Components

Crowdsourcing is dependent on a number of skilled workers who are needed to accomplish spatial tasks. This has been an active area of research and is gaining wide popularity now. Most of these tasks can be completed online due to convenience, but this method fails when there is a need of completing a task at actual physical locations. This has led to a new area called Spatial crowd sourcing that consists of location-specific tasks that require people who can accomplish them to physically arrive at specific locations. The tasks which require specific skillsets, completion times or other constraints are matched ...