Engineering Commons^™

A Bayesian Network Based Adaptability Design Of Product Structures For Function Evolution, Shaobo Li, Yongming Wu, Yan-Xia Xu, Jie Hu, Jianjun Hu

Faculty Publications

Structure adaptability design is critical for function evolution in product families, in which many structural and functional design factors are intertwined together with manufacturing cost, customer satisfaction, and final market sales. How to achieve a delicate balance among all of these factors to maximize the market performance of the product is too complicated to address based on traditional domain experts’ knowledge or some ad hoc heuristics. Here, we propose a quantitative product evolution design model that is based on Bayesian networks to model the dynamic relationship between customer needs and product structure design. In our model, all of the structural …

Atomic Layer Deposition On Porous Materials: Problems With Conventional Approaches To Catalyst And Fuel Cell Electrode Preparation, Tzia Ming Onn, Rainer Küngas, Paolo Fornasiero, Kevin Huang, Raymond J. Gorte

Faculty Publications

Atomic layer deposition (ALD) offers exciting possibilities for controlling the structure and composition of surfaces on the atomic scale in heterogeneous catalysts and solid oxide fuel cell (SOFC) electrodes. However, while ALD procedures and equipment are well developed for applications involving flat surfaces, the conditions required for ALD in porous materials with a large surface area need to be very different. The materials (e.g., rare earths and other functional oxides) that are of interest for catalytic applications will also be different. For flat surfaces, rapid cycling, enabled by high carrier-gas flow rates, is necessary in order to rapidly grow thicker …

An Experimental Study On Static And Dynamic Strain Sensitivity Of Embeddable Smart Concrete Sensors Doped With Carbon Nanotubes For Shm Of Large Structures, Andrea Meoni, Antonella D'Alessandro, Austin Downey, Enrique García-Macías, Marco Rallini, A. Luigi Materazzi, Luigi Torre, Simon Laflamme, Rafael Castro-Triguero, Filippo Ubertini

Faculty Publications

The availability of new self-sensing cement-based strain sensors allows the development of dense sensor networks for Structural Health Monitoring (SHM) of reinforced concrete structures. These sensors are fabricated by doping cement-matrix mterials with conductive fillers, such as Multi Walled Carbon Nanotubes (MWCNTs), and can be embedded into structural elements made of reinforced concrete prior to casting. The strain sensing principle is based on the multifunctional composites outputting a measurable change in their electrical properties when subjected to a deformation. Previous work by the authors was devoted to material fabrication, modeling and applications in SHM. In this paper, we investigate the …

Aspie: A Framework For Active Sensing And Processing Of Complex Events In The Internet Of Manufacturing Things, Shaobo Li, Weixing Chen, Jie Hu, Jianjun Hu

Faculty Publications

Rapid perception and processing of critical monitoring events are essential to ensure healthy operation of Internet of Manufacturing Things (IoMT)-based manufacturing processes. In this paper, we proposed a framework (active sensing and processing architecture (ASPIE)) for active sensing and processing of critical events in IoMT-based manufacturing based on the characteristics of IoMT architecture as well as its perception model. A relation model of complex events in manufacturing processes, together with related operators and unified XML-based semantic definitions, are developed to effectively process the complex event big data. A template based processing method for complex events is further introduced to conduct …

A Novel Evolutionary Algorithm For Designing Robust Analog Filters, Shaobo Li, Wang Zou, Jianjun Hu

Faculty Publications

Designing robust circuits that withstand environmental perturbation and device degradation is critical for many applications. Traditional robust circuit design is mainly done by tuning parameters to improve system robustness. However, the topological structure of a system may set a limit on the robustness achievable through parameter tuning. This paper proposes a new evolutionary algorithm for robust design that exploits the open-ended topological search capability of genetic programming (GP) coupled with bond graph modeling. We applied our GP-based robust design (GPRD) algorithm to evolve robust lowpass and highpass analog filters. Compared with a traditional robust design approach based on a state-of-the-art …

Mechanical And Geometrical Determinants Of Wall Stress In Abdominal Aortic Aneurysms: A Computational Study, Dara Azar, Donya Ohadi, Alexander Rachev, John F. Eberth, Mark J. Uline, Tarek Shazly

Faculty Publications

An aortic aneurysm (AA) is a focal dilatation of the aortic wall. Occurrence of AA rupture is an all too common event that is associated with high levels of patient morbidity and mortality. The decision to surgically intervene prior to AA rupture is made with recognition of significant procedural risks, and is primarily based on the maximal diameter and/or growth rate of the AA. Despite established thresholds for intervention, rupture occurs in a notable subset of patients exhibiting sub-critical maximal diameters and/or growth rates. Therefore, a pressing need remains to identify better predictors of rupture risk and ultimately integrate their …

Patent Keyword Extraction Algorithm Based On Distributed Representation For Patent Classification, Jie Hu, Shaobo Li, Yong Yao, Liya Yu, Guanci Yang, Jianjun Hu

Faculty Publications

Many text mining tasks such as text retrieval, text summarization, and text comparisons depend on the extraction of representative keywords from the main text. Most existing keyword extraction algorithms are based on discrete bag-of-words type of word representation of the text. In this paper, we propose a patent keyword extraction algorithm (PKEA) based on the distributed Skip-gram model for patent classification. We also develop a set of quantitative performance measures for keyword extraction evaluation based on information gain and cross-validation, based on Support Vector Machine (SVM) classification, which are valuable when human-annotated keywords are not available. We used a standard …

Comparing Machine Learning And Decision Making Approaches To Forecast Long Lead Monthly Rainfall: The City Of Vancouver, Canada, Zahra Zahmatkesh, Erfan Goharian

Faculty Publications

Estimating maximum possible rainfall is of great value for flood prediction and protection, particularly for regions, such as Canada, where urban and fluvial floods from extreme rainfalls have been known to be a major concern. In this study, a methodology is proposed to forecast real-time rainfall (with one month lead time) using different number of spatial inputs with different orders of lags. For this purpose, two types of models are used. The first one is a machine learning data driven-based model, which uses a set of hydrologic variables as inputs, and the second one is an empirical-statistical model that employs …

Peri-Elastodynamic Simulations Of Guided Ultrasonic Lamb Waves In Smart Structure With Surface Mounted Pzt, Subir Patra, Hossain Ahmed, Sourav Banerjee

Faculty Publications

Peridynamic based elastodynamic computation tool named Peri-elastodynamics is proposed herein to simulate the three-dimensional (3D) Lamb wave modes in materials for the first time. Peri-elastodynamics is a nonlocal meshless approach which is a scale-independent generalized technique to visualize the acoustic and ultrasonic waves in plate-like structure, micro-electro-mechanical systems (MEMS) and nanodevices for their respective characterization. In this article, the characteristics of the fundamental Lamb wave modes are simulated in a sample plate-like structure. Lamb wave modes are generated using a surface mounted piezoelectric (PZT) transducer which is actuated from the top surface. The proposed generalized Peri-elastodynamics method is not only …

A Hierarchical Feature Extraction Model For Multi-Label Mechanical Patent Classification, Jie Hu, Shaobo Li, Jianjun Hu, Guanci Yang

Faculty Publications

Various studies have focused on feature extraction methods for automatic patent classification in recent years. However, most of these approaches are based on the knowledge from experts in related domains. Here we propose a hierarchical feature extraction model (HFEM) for multi-label mechanical patent classification, which is able to capture both local features of phrases as well as global and temporal semantics. First, a n-gram feature extractor based on convolutional neural networks (CNNs) is designed to extract salient local lexical-level features. Next, a long dependency feature extraction model based on the bidirectional long–short-term memory (BiLSTM) neural network model is proposed to …

Cenozoic Tectono-Stratigraphic Evolution And Petroleum System Of The Eastern Cordillera Foothills And Adjacent Basins (Colombia), Essam Saeid

Theses and Dissertations

New gravity, magnetic, well and 3D seismic data provides a better understanding of regional structures and tectonic movement affecting the petroleum system and sedimentary history of an important region of oil production in the Foothills of the Eastern Cordillera of Colombia. To the south the Garzón fault was previously interpreted as a right-lateral strikeslip fault. New seismic, well, and gravity data demonstrate that this fault is also a low-angle (12–17 degrees) Andean fault that thrusts PreCambrian basement 10 to 17 km northwestward over Miocene rocks of the Upper Magdalena Valley (UMV) in a prospective footwall anticline. New geophysical data as …

Regulation Of Pituitary Progenitor Differentiation By Β-Catenin, Julie Leann Youngblood

Theses and Dissertations

The pituitary gland is a critical organ that is necessary for many physiological processes, including growth, reproduction, and stress response. These vital processes are regulated through the secretion of pituitary hormones from specialized cell types. Pituitary hormone-producing cells arise from a common pool of pituitary progenitors in the developing Rathke’s pouch, and mutations that disrupt the formation and differentiation of pituitary progenitors often result in hypopituitarism, pituitary adenomas, or craniopharyngiomas. Thus, it is necessary to determine the mechanisms of pituitary development in order to understand the ways in which these congenital defects and tumors develop and disrupt pituitary function. Canonical …

Hydrothermal Carbonization: Modeling, Final Properties Design And Applications: A Review, Silvia Román, Judy Libra, Nicole Berge, Eduardo Sabio, Kyoung Ro, Liang Li, Beatriz Ledesma, Andrés Alvarez, Sunyoung Bae

Faculty Publications

Active research on biomass hydrothermal carbonization (HTC) continues to demonstrate its advantages over other thermochemical processes, in particular the interesting benefits that are associated with carbonaceous solid products, called hydrochar (HC). The areas of applications of HC range from biofuel to doped porous material for adsorption, energy storage, and catalysis. At the same time, intensive research has been aimed at better elucidating the process mechanisms and kinetics, and how the experimental variables (temperature, time, biomass load, feedstock composition, as well as their interactions) affect the distribution between phases and their composition. This review provides an analysis of the state of …

Novel Topologies Based Rf Filtering Components And Methodologies For Wireless Communication System, Wei Jiang

Theses and Dissertations

Driven by the rapid progress of wireless communication technology in the past several decades, multiple generations of cellular technologies have been developed, deployed, and adopted to provide more convenient communication services to users. Nowadays, the personal hand-held devices, supporting multiple wireless standards, have been a multimedia terminal encompassing elements and functions such as video callers, Internet connectivity, home appliances remote controller, GPS, TV reception, and beyond. In order to accommodate a variety of wireless standards in a single device without imposing a substantial increase in cost and size, current and future RF transceiver front-ends should be designed with more attention. …

On The Security And Quality Of Wireless Communications In Outdoor Mobile Environment, Sharaf J. Malebary

Theses and Dissertations

The rapid advancement in wireless technology along with their low cost and ease of deployment have been attracting researchers academically and commercially. Researchers from private and public sectors are investing into enhancing the reliability, robustness, and security of radio frequency (RF) communications to accommodate the demand and enhance lifestyle. RF base communications -by nature- are slower and more exposed to attacks than a wired base (LAN). Deploying such networks in various cutting-edge mobile platforms (e.g. VANET, IoT, Autonomous robots) adds new challenges that impact the quality directly. Moreover, adopting such networks in public outdoor areas make them vulnerable to various …

Fundamental Aspects Of A Novel Technology For Abatement Of Indoor Allergens, Odell Lendor Glenn Jr.

Theses and Dissertations

The overall goal of this research was to develop a novel approach to reduce the potency of certain asthma triggers, namely, proteins produced by pests or pets in indoor environments. The broad hypothesis of the research was that naturally occurring essential oils will demonstrate enhanced denaturing ability. In any indoor environment, allergens are bound to dry dust particles. In this work, the effectiveness of using dry ice and CO2 with potential for essential oils on dry allergenic proteins through CFD modeling and ELISA methods were evaluated.

There are three objectives central to this work. The first objective was to apply …

Bytecode-Based Multiple Condition Coverage: An Initial Investigation, Srujana Bollina

Theses and Dissertations

Masking occurs when one condition prevents another condition from influencing the output of a Boolean expression. Logic-based adequacy criteria such as Multiple Condition Coverage (MCC) are designed to overcome masking at the within-expression level, but can offer no guarantees about masking in subsequent expressions. As a result, a Boolean expression written as a single complex statement will yield test cases that are more likely to overcome masking than when the expression is written as series of simple statements. Many approaches to automated analysis and test case generation for Java systems operate not on the source code representation of code, but …

Nox Formation In Syngas/Air Combustion, Nazli Asgari

Theses and Dissertations

Syngas is a reliable energy source derived from the gasification of coal and other solid fuels. The feedstock type and the production process of syngas can affect the composition of syngas. Gas turbines utilizing high hydrogen content (HHC) fuels like syngas for power generation applications need to meet stringent pollutant emission standards, particularly with respect to nitrogen oxides (NOx). For gas turbine conditions, reliable experimental data, especially at high-pressure, is necessary for both generating accurate NOx prediction models and improving reaction pathways regarding the NOx chemistry. In this study, NOx formation in post-flame gases of syngas combustion at different conditions …

Hydrothermal Carbonization Of Food Waste For Nutrient Recovery And Reuse, Ifeolu M. Idowu

Theses and Dissertations

Food waste represents a rather large and currently underutilized source of potentially available and reusable nutrients. Laboratory-scale experiments evaluating the hydrothermal carbonization of food wastes collected from restaurants were conducted to understand how changes in feedstock composition and carbonization process conditions influence primary and secondary nutrient fate. Results from this work indicate that at all evaluated reaction times and temperatures, the majority of nitrogen, calcium, and magnesium remain integrated within the solid-phase, while the majority of potassium and sodium reside in the liquid-phase. The fate of phosphorus is dependent on reaction times and temperatures, with solid-phase integration increasing with higher …

Social Engineering Knowledge Measured As A Security Countermeasure, Christopher Artejus Sanders

Theses and Dissertations

Social Engineering has become a significant threat to the security of business, government, and academic institutions. As vulnerabilities to social engineering attacks increase, organizations must incorporate risk mitigation strategies to their portfolios of Information Systems Security Countermeasures (ISSC). The goal is to implement mitigation strategies that balance the cost of implementation, the privacy of employees, and the resulting expected costs of social engineering attacks. In this paper we develop an analytical model that calculates the total cost of protection, including the trade-off between the cost of implementing protection strategies and the resulting expected cost of social engineering attacks. We use …

Ontology-Guided Pre-Release Inference Disruption, Mark Stephen Daniels

Theses and Dissertations

We investigate privacy violations occurring when non-confidential patient data is combined with medical domain ontologies to disclose a patient’s protected health information (PHI). We propose a framework that detects privacy violations and eliminates undesired inferences. Our inference channel removal process is based on controlling the release of the data items that lead to undesired inferences. These data items are either blocked from release or generalized to eliminate the disclosure of the PHI. We show that our method is sound and complete. Soundness means the only inference paths generated logically follow from released data and corresponding domain knowledge. Completeness means we …

Development Of Bimetallic Catalysts For Dry Reforming Of Methane And Hydrogenation Of Succinic Acid, Jayson Michael Keels

Theses and Dissertations

Advances in natural gas recovery have greatly impacted the global economy; the abundant supply of gas has revealed new opportunities and challenges in a wide range of markets within the fuels and chemicals industries. One such opportunity exists with the overabundance of gas from remote wells that is flared or emitted because of the high costs associated with transportation of a chemical with such a high molar volume. A possible solution is an on-site process to convert gas to higher value chemicals that are liquid at standard conditions, and can more easily be transported. As a first step, CO2 from …

The Visual Ecology Of Speyeria Mormonia, Natalie Sanchez Gonzalez

Theses and Dissertations

Variations in environmental factors such as temperature, precipitation, and day length during larval development are known to affect morphological traits in butterflies related to their visual ecology, including eye size and wing color. These vision-related traits are important for the ability of diurnal butterfly species to detect mates, especially at long distances. Thus, changes in environmental conditions may result in phenotypic modifications to butterflies which may alter their visual ecology and subsequently, their reproductive fitness. To study the interaction of phenotypic plasticity and visual ecology in the Mormon Fritillary, Speyeria mormonia, I set up a natural-laboratory experiment at the Rocky …

High Resolution Radiation Detectors Based On 4h-Sic N-Type Epitaxial Layers And Pixilated Cdznte Single Crystal Devices, Cihan Oner

Theses and Dissertations

Silicon Carbide (SiC) is an indirect wide bandgap semiconductor with high thermal conductivity, high breakdown electric field, high carrier saturation drift velocity, and large displacement energy making it a suitable candidate for replacing conventional radiation detectors based on Si, Ge, CdTe, and CdZnTe (CZT). In this dissertation, fabrication and characterization of high-resolution Schottky barrier detectors for alpha particles using 20 µm thick n-type 4H-SiC epitaxial layers are reported. Schottky barriers were obtained by depositing circular nickel contacts of ~10 mm2 area.

Room temperature current-voltage (I-V) measurements revealed Schottky barrier heights of the order of 1.7 eV, ideality factor of ~1.1, …

Understanding Geopolymerization Process For Enhancement Of Mechanical Properties Of Fly Ash Based-Geopolymer Concrete, Lateef Najeh Assi

Theses and Dissertations

Concrete is a major construction material that is largely made up of cement. Unfortunately, the manufacturing process for the cement currently used to produce concrete releases a great deal of CO2, which endangers the environment. Hence, finding alternatives to ordinary Portland cement is of extreme importance. The intellectual contribution of this dissertation is the development of an improved understanding of the geopolymerization process so that the compressive strength of cement can be maximized while the need for external heating is minimized. The intent is to create a substance to replace commonly used cement without sacrificing other beneficial properties. The first …

The Design, Development, And Evaluation Of A Usable And Privacy-Enhanced Telepresence Interface For Older Adults, Xian Wu

Theses and Dissertations

Maintaining health and wellness while aging-in-place independently is crucial for older adults. Telepresence technology can be potentially beneficial for this target population to stay socially connected. However, this technology is not specifically designed for older adults. For this target population to adopt such technology successfully, it is important to ensure that they do not experience usability barriers. This research uses HCI/HRI concepts and technology design principles for older adults to design, develop and test telepresence user interfaces (UI). This addresses the following research questions: 1): What are the essential usability and privacy-enhanced features needed to inform the design and development …

Hydrodeoxygenation Of Acetic Acid Using Monometallic And Bimetallic Catalysts Supported On Carbon, José Luis Contreras Mora

Theses and Dissertations

Heterogeneous catalytic hydrodeoxygenation (HDO) of biomass-derived feeds is a deoxygenation process that is of highly interest. Carboxylic acids are one of the main components of bio-oils and acetic acid is one of the most abundant of these carboxylic acids. This acid is rich in oxygen, therefore a lot of research to produce fuel and other valuable chemicals such as ethanol is of interest.

This dissertation explores the gas-phase catalytic HDO of AA over catalysts supported on activated carbon (Cp-97). Temperature-dependent conversion and selectivity were studied at 1 atm from 200-400⁰C with an AA concentration of 1.1% and 20% …

Selective Deposition Of Platinum By Strong Electrostatic Adsorption Onto Cobalt- And Iron-Based Catalysts For Fischer-Tropsch Synthesis, Fahad A. Almalki

Theses and Dissertations

Cobalt and iron based catalysts are commercially predominant for Fischer-Tropsch synthesis, Co-based catalysts for their stability, activity, and inactivity for the water gas shift reaction and Fe-based catalysts for their cheap cost, high light-olefins and alcohols selectivity, and tolerance to H2/CO ratio. These catalysts are structure sensitive with lower activity at nanoparticle sizes smaller than 6-8 nm. Co-based catalysts exhibit high activity, low CH4 selectivity, and high C5+ selectivity, while Fe-based catalysts are more selective to low-molecular-weight hydrocarbons such as olefins and alcohols. The reducibility of cobalt and iron is another important factor which may be key for improving their …

Assessing Exposure To Occupants In An Indoor Space Due To Expirated Aerosols: Application Of Computational Fluid Dynamics, Firoza Binte Omar

Theses and Dissertations

Indoor environment is an important issue for the well-being of the society. In the United States more than 90% people spend their time indoor, indoor air pollution is more culpable than the pollution outside air. Two third of US businesses lose more than $100,000 per year due to workplace related illness. The trend of sharing the work space has an impact on total sick leaves in a company. Infectious particles released by a flu sufferer’s sneezing, coughing or even laughing can be a vital source. A thorough analysis on infectious particles’ transmission and air flow of the space can provide …

Probabilistic Multilevel Constitutive Model Of The Compressive Strength Of Hardened Cement Paste Reinforced With Mwcnts, Yohanna Mejia Cruz

Theses and Dissertations

Constitutive models available in the literature typically describe the compressive strength of ordinary Portland cement paste (OPC) in a deterministic fashion, in some cases as a function of variables such as W/C, porosity, and the clinker chemical composition. The significant effect of the proportion of W/C on the final strength, porosity and density have been reported in several works in material science. Some studies have shown that the addition of MWCNTs can also modify the microstructure of cement significantly, and improve compressive strength and other mechanical and physical properties. In principle, W/C, MWCNTs addition, porosity, density, and compressive strength are …