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Differential Measurement Error In House Price Indices, Darren Hayunga, R. Kelley Pace, Shuang Zhu, Raffaella Calabrese Jan 2024

Differential Measurement Error In House Price Indices, Darren Hayunga, R. Kelley Pace, Shuang Zhu, Raffaella Calabrese

Faculty Publications

This article investigates measurement errors when using indices to model house prices over time. Our analysis, comparing index prices to actual transaction values, reveals that in many cases, widely-used indices display measurement errors correlated with the index values. Measurement error correlated with predictors constitutes “differential measurement error” at the level of the data generating process (DGP). We further explore the presence of differential measurement error within the context of mortgage lending. Our findings uncover substantial measurement errors in mortgage data, which not only diminish the predictive accuracy of models but also introduce notable biases in the coefficient estimates of variables.


The Incompatibility Of The Commons And The Public, Roy L. Heidelberg Jan 2024

The Incompatibility Of The Commons And The Public, Roy L. Heidelberg

Faculty Publications

In this essay I consider the conceptual conflict between the public as a modern political category and the idea of the commons. By linking the idea of the public to an early exposition that explicitly sought a distinction between the commons and the public, I show how the generalization inherent in the public contravenes the particularity of the commons. This poses important political problems for how a modern commons or a modern notion of the commons is conceived and also allows for a nuanced understanding of the political challenge posed against the commons itself.


The Aftermath Of The 2019 Pulwama Terror Attack–Religion, Nationalism And Exclusion In Online News Comment Sections, Nihar Sreepada, Ioana Coman Jan 2024

The Aftermath Of The 2019 Pulwama Terror Attack–Religion, Nationalism And Exclusion In Online News Comment Sections, Nihar Sreepada, Ioana Coman

Faculty Publications

This study analyses the Indian and Pakistani publics reactions of the extensive coverage of the Pulwama terror attack, through an analysis of the online comments appearing at the end of the news stories covering the attack from the two leading English newspapers: Times of India (TOI) (India), and Dawn (D) (Pakistan). A qualitative content analysis is performed to compare and examine this dialogue emerging in the news comments sections. Findings are explored and discussed through conceptualizations of religion, nationalism, and a social psychological perspective towards exclusion of out-groups.


A Sociolinguistic Study Of Pronominal Expression In Cali, Rafael Orozco, Margareth Marmolejo, Róbinson Grajales Jan 2024

A Sociolinguistic Study Of Pronominal Expression In Cali, Rafael Orozco, Margareth Marmolejo, Róbinson Grajales

Faculty Publications

This sociolinguistic investigation analyzes variable subject pronoun expression in the PRESEEA-Cali corpus, which is socially stratified in terms of speaker’s gender, age and educational level. We explored 6409 tokens seeking to determine the effects of six predictors: 3 internal and 3 external. Results uncover the highest pronominal rate (28,6%) found to date in a continental Andean highland speech community. The linguistic conditioning shows the strongest effect of grammatical person and number of the subject; specifically, uno is the pronoun that most strongly favors overt subjects. The social conditioning reveals a strong effect of speaker’s age with the youngest speakers disfavoring …


Subject Pronoun Expression In Andean Colombian Spanish: The Preseea-Cali Corpus, Rafael Orozco, Margareth Marmolejo Caicedo, Róbinson Grajales Jan 2024

Subject Pronoun Expression In Andean Colombian Spanish: The Preseea-Cali Corpus, Rafael Orozco, Margareth Marmolejo Caicedo, Róbinson Grajales

Faculty Publications

This preliminary investigation explores subject pronoun expression in the PRESEEA-Cali corpus. We explore the effects of five predictor variables (2 social 3 linguistic) on 4425 tokens. Findings reveal the highest pronominal rate (29.7%) found in a continental Latin American speech community. The linguistic conditioning uncovers that grammatical person and number of the subject exerts the strongest conditioning force among all the predictor variables explored. Specifically, uno constitutes the pronoun that most strongly favors overt subjects. The social conditioning reveals that women promote overt subjects, as occurs in the Caribbean region, but contrary to findings in Medellín. Moreover, the effects of …


De Francisco Sales A Ilan Stavans: Apuntes Sobre Mediación Y Cultura En La Adaptación Y Traducción De Don Quijote En Los Estados Unidos De América, Carmela V. Mattza Jan 2024

De Francisco Sales A Ilan Stavans: Apuntes Sobre Mediación Y Cultura En La Adaptación Y Traducción De Don Quijote En Los Estados Unidos De América, Carmela V. Mattza

Faculty Publications

This communication examines the translation and adaptation of Don Quixote in the United States, focusing on editions in Spanish, English, and Spanglish. It highlights Ilan Stavans’ two graphic novels (2018), analyzing them in relation to the annotated edition by Francisco Sales (1836), a professor at Harvard College at the time, recognized as the first Spanish edition of Don Quixote published in the United States.


Negotiating Quotidian Justice In The Science Classroom, Christopher Irwin, Joshua Ellis Jan 2024

Negotiating Quotidian Justice In The Science Classroom, Christopher Irwin, Joshua Ellis

Faculty Publications

In this conceptual paper, we explore how science teachers might enact social justice through their everyday science instruction. Drawing on empirical literature and our own K-12 teaching experience, we develop a heuristic for mapping classroom discourses to engage in action and reflection to change both the world of the classroom community, and the world beyond the school. We suggest how this heuristic can be used for justice-oriented science teaching independently of (or as a supplement to) any existing frameworks for science teaching to promote social justice. Our proposed model for social justice through disciplinary science teaching frames justice not as …


Mcmurdo Dry Valley Lake Edge 'Moats': The Ecological Intersection Between Terrestrial And Aquatic Polar Desert Habitats, Michael S. Stone, Shawn P. Devlin, Ian Hawes, Kathleen A. Welch, Michael N. Gooseff, Cristina Takacs-Vesbach, Rachael Morgan-Kiss, Byron J. Adams, J. E. Barrett, John C. Priscu, Peter T. Doran Jan 2024

Mcmurdo Dry Valley Lake Edge 'Moats': The Ecological Intersection Between Terrestrial And Aquatic Polar Desert Habitats, Michael S. Stone, Shawn P. Devlin, Ian Hawes, Kathleen A. Welch, Michael N. Gooseff, Cristina Takacs-Vesbach, Rachael Morgan-Kiss, Byron J. Adams, J. E. Barrett, John C. Priscu, Peter T. Doran

Faculty Publications

Aquatic ecosystems - lakes, ponds and streams - are hotspots of biodiversity in the cold and arid environment of Continental Antarctica. Environmental change is expected to increasingly alter Antarctic aquatic ecosystems and modify the physical characteristics and interactions within the habitats that they support. Here, we describe physical and biological features of the peripheral 'moat' of a closed-basin Antarctic lake. These moats mediate connectivity amongst streams, lake and soils. We highlight the cyclical moat transition from a frozen winter state to an active open-water summer system, through refreeze as winter returns. Summer melting begins at the lakebed, initially creating an …


Measuring And Modelling Functional Moat Area In Perennially Ice-Covered Lake Fryxell, Antarctica, Michael S. Stone, Mark R. Salvatore, Hilary A. Dugan, Madeline E. Myers, Peter T. Doran Jan 2024

Measuring And Modelling Functional Moat Area In Perennially Ice-Covered Lake Fryxell, Antarctica, Michael S. Stone, Mark R. Salvatore, Hilary A. Dugan, Madeline E. Myers, Peter T. Doran

Faculty Publications

The perennially ice-covered lakes of the McMurdo Dry Valleys (MDVs), Antarctica, are an important reservoir of liquid water in an arid and largely frozen environment. During the austral summer, the margins of these ice covers melt, forming a “moat” of liquid water and thin ice, allowing exchange between lake waters and the atmosphere to occur and serving as an interface between lake, soil, and stream ecosystems. The size of these moats varies from year to year. Here, we have established the first published record of moat area changes at MDVs’ Lake Fryxell through time using manual traces of the moat …


Summer-Wet Hydrologic Cycle During The Middle Miocene Of The United States: New Evidence From Fossil Fungi, Jennifer M.K. O’Keefe, Matthew J. Pound, Ingrid C. Romero, Noelia B. Nuñez Otaño, Martha E. Gibson, Jessica Mccoy, Margaret E. Alden, C. Jolene Fairchild, Julia Fitzpatrick, Emily Hodgson, Taylor Horsfall, Savannah Jones, June E. Lennex-Stone, Christopher A. Marsh, Alyssa A. Patel, Tyler M. Spears, Laikin Tarlton, Liberty F. Smallwood, O. L. Vanderespt, Jeremyah R. Cabrera, Cortland F. Eble, William C. Rember, James E. Starnes, Mac H. Alford, Alyson Brink, Sophie Warny Jan 2024

Summer-Wet Hydrologic Cycle During The Middle Miocene Of The United States: New Evidence From Fossil Fungi, Jennifer M.K. O’Keefe, Matthew J. Pound, Ingrid C. Romero, Noelia B. Nuñez Otaño, Martha E. Gibson, Jessica Mccoy, Margaret E. Alden, C. Jolene Fairchild, Julia Fitzpatrick, Emily Hodgson, Taylor Horsfall, Savannah Jones, June E. Lennex-Stone, Christopher A. Marsh, Alyssa A. Patel, Tyler M. Spears, Laikin Tarlton, Liberty F. Smallwood, O. L. Vanderespt, Jeremyah R. Cabrera, Cortland F. Eble, William C. Rember, James E. Starnes, Mac H. Alford, Alyson Brink, Sophie Warny

Faculty Publications

Hydrologic reconstructions from North America are largely unknown for the Middle Miocene. Examination of fungal palynomorph assemblages coupled with traditional plant-based palynology permits delineation of local, as opposed to regional, climate signals and provides a baseline for study of ancient fungas. Here, the Fungi in a Warmer World project presents paleoecology and paleoclimatology of 351 fungal morphotypes from 3 sites in the United States: the Clarkia Konservat-Lagerstätte site (Idaho), the Alum Bluff site (Florida), and the Bouie River site (Mississippi). Of these, 83 fungi are identified as extant taxa and 41 are newly reported from the Miocene. Combining new plant-based …


Holocene Hydroclimate Stability In Three Lake Sediment Records From The Southeastern United States, Aubrey L. Hillman, Sumar B. Hart, Vann Smith, Sophie Warny Jan 2024

Holocene Hydroclimate Stability In Three Lake Sediment Records From The Southeastern United States, Aubrey L. Hillman, Sumar B. Hart, Vann Smith, Sophie Warny

Faculty Publications

Many Holocene paleoclimate records from the southeastern United States (SE US) have limited chronological constraints and/or low sedimentation rates and consequently low resolution; this presents challenges in discerning the relative importance of synoptic–scale drivers of past hydroclimate. In this study we summarize three lake sediment records that are uniquely located to test hypotheses regarding the importance of the Pacific North American (PNA) pattern and the North Atlantic Oscillation (NAO) over the last 5000 years. At Pigeon Marsh, Buck Pond, and Halls Pond, we used sedimentological (radiocarbon dating of transect cores), physical (grain size), geochemical (carbon and nitrogen ratios and isotopes), …


Migration And Erosion In Tidal And River Channels In Bangladesh, Katharine M. Donato, Leslie Valentine, Amanda Carrico, Carol A. Wilson, Kimberly G. Rogers, Timo Tonassi Jan 2024

Migration And Erosion In Tidal And River Channels In Bangladesh, Katharine M. Donato, Leslie Valentine, Amanda Carrico, Carol A. Wilson, Kimberly G. Rogers, Timo Tonassi

Faculty Publications

Environmental stressors and natural disasters are changing the physical landscapes in many countries worldwide. In this paper, we ask whether and how erosion affects internal and international migration in Bangladesh. Building on prior studies, we use data from 3, 600 households in 18 research sites to investigate how erosion in tidal and river channels is related to the risk of making a first internal or international trip, net of extreme weather conditions and other relevant attributes. Findings reveal that the relationship between erosion and the likelihood of making a first domestic or international trip is moderated by livelihood type and …


Contribution Of Campaign Gnss Toward Parsing Subsidence Rates By Time And Depth In Coastal Bangladesh, Michael S. Steckler, Md Hasnat Jaman, Céline Jo Grall, Steven L. Goodbred, Carol A. Wilson, Bar Oryan Jan 2024

Contribution Of Campaign Gnss Toward Parsing Subsidence Rates By Time And Depth In Coastal Bangladesh, Michael S. Steckler, Md Hasnat Jaman, Céline Jo Grall, Steven L. Goodbred, Carol A. Wilson, Bar Oryan

Faculty Publications

Coastal regions are vulnerable to rising seas, increasing storm magnitude, and decimation of ecologically-fragile areas. Deltas are particularly sensitive to the balance between sea-level rise, land subsidence and sedimentation that determine relative elevation. Bangladesh has been highlighted as being at risk from sea-level rise. Integrating measurements from different methods can approach a more complete understanding of factors controlling areally and temporally varying subsidence rates. To augment our compilation of rates from stratigraphic wells, historic buildings, vertical strainmeters, RSET-MH, and continuous Global Navigation Satellite System, we resurveyed 48 geodetic monuments in coastal Bangladesh ∼18 years after the monuments were installed. A …


Accelerating L-Shaped Two-Stage Stochastic Scuc With Learning Integrated Benders Decomposition, Fouad Hasan, Amin Kargarian Jan 2024

Accelerating L-Shaped Two-Stage Stochastic Scuc With Learning Integrated Benders Decomposition, Fouad Hasan, Amin Kargarian

Faculty Publications

Benders decomposition is widely used to solve large mixed-integer problems. This article takes advantage of machine learning and proposes a variant of Benders decomposition to tackle two-stage stochastic security-constrained unit commitment (SCUC). The problem is decomposed into a master problem (MP) and subproblems (SPs) corresponding to individual load scenarios. The primary objective is to mitigate computational expenses and memory consumption associated with Benders decomposition by generating tighter cuts and reducing the MP's dimensions. A regressor reads load profile scenarios and predicts objective function proxy values for the SPs, enabling the creation of tighter cuts for the MP. The numerical difference …


Optimizing Privacy And Utility Tradeoffs For Group Interests Through Harmonization, Bishwas Mandal, George Amariucai, Shuangqing Wei Jan 2024

Optimizing Privacy And Utility Tradeoffs For Group Interests Through Harmonization, Bishwas Mandal, George Amariucai, Shuangqing Wei

Faculty Publications

We propose a novel problem formulation to address the privacy-utility tradeoff, specifically when dealing with two distinct user groups characterized by unique sets of private and utility attributes. Unlike previous studies that primarily focus on scenarios where all users share identical private and utility attributes and often rely on auxiliary datasets or manual annotations, we introduce a collaborative data-sharing mechanism between two user groups through a trusted third party. This third party uses adversarial privacy techniques with our proposed data-sharing mechanism to internally sanitize data for both groups and eliminates the need for manual annotation or auxiliary datasets. Our methodology …


Communication-Efficient Admm Using Quantization-Aware Gaussian Process Regression, Aldo Duarte, Truong X. Nghiem, Shuangqing Wei Jan 2024

Communication-Efficient Admm Using Quantization-Aware Gaussian Process Regression, Aldo Duarte, Truong X. Nghiem, Shuangqing Wei

Faculty Publications

In networks consisting of agents communicating with a central coordinator and working together to solve a global optimization problem in a distributed manner, the agents are often required to solve private proximal minimization subproblems. Such a setting often requires a decomposition method to solve the global distributed problem, resulting in extensive communication overhead. In networks where communication is expensive, it is crucial to reduce the communication overhead of the distributed optimization scheme. Gaussian processes (GPs) are effective at learning the agents' local proximal operators, thereby reducing the communication between the agents and the coordinator. We propose combining this learning method …


Initial Exploration Of Zero-Shot Privacy Utility Tradeoffs In Tabular Data Using Gpt-4, Bishwas Mandal, George Amariucai, Shuangqing Wei Jan 2024

Initial Exploration Of Zero-Shot Privacy Utility Tradeoffs In Tabular Data Using Gpt-4, Bishwas Mandal, George Amariucai, Shuangqing Wei

Faculty Publications

We investigate the application of large language models (LLMs), specifically GPT-4, to scenarios involving the tradeoff between privacy and utility in tabular data. Our approach entails prompting GPT-4 by transforming tabular data points into textual format, followed by the inclusion of precise sanitization instructions in a zero-shot manner. The primary objective is to sanitize the tabular data in such a way that it hinders existing machine learning models from accurately inferring private features while allowing models to accurately infer utility-related attributes. We explore various sanitization instructions. Notably, we discover that this relatively simple approach yields performance comparable to more complex …


The Economics Of Privacy And Utility: Investment Strategies, Chandra Sharma, George Amariucai, Shuangqing Wei Jan 2024

The Economics Of Privacy And Utility: Investment Strategies, Chandra Sharma, George Amariucai, Shuangqing Wei

Faculty Publications

The inevitable leakage of privacy as a result of unrestrained disclosure of personal information has motivated extensive research on robust privacy-preserving mechanisms. However, existing research is mostly limited to solving the problem in a static setting with disregard for the privacy leakage over time. Unfortunately, this treatment of privacy is insufficient in practical settings where users continuously disclose their personal information over time resulting in an accumulated leakage of the users' sensitive information. In this paper, we consider privacy leakage over a finite time horizon and investigate optimal strategies to maximize the utility of the disclosed data while limiting the …


Performance Optimization Of Software-Defined Industrial Internet-Of-Things (Sd-Iiot), Jehad Ali, Celestine Iwendi, Gaoyang Shan, Hsiao Chun Wu, Mohammed J.F. Alenazi, Zaid Bin Faheem, Cresantus N. Biamba Jan 2024

Performance Optimization Of Software-Defined Industrial Internet-Of-Things (Sd-Iiot), Jehad Ali, Celestine Iwendi, Gaoyang Shan, Hsiao Chun Wu, Mohammed J.F. Alenazi, Zaid Bin Faheem, Cresantus N. Biamba

Faculty Publications

Software-Defined Networking (SDN) offers a centralized network management approach that can effectively address the complex and varied traffic demands characteristic of Industrial Internet of Things (IIoT) environments by decoupling the control plane from the data plane. The centralized control architecture of SDN necessitates the performance optimization of controllers to manage diverse traffic efficiently within IIoT applications. This paper explores the criteria for selecting controllers in SDN-enabled IIoT (SD-IIoT) environments, utilizing the Less Complex Analytic Network Process (LC-ANP) to establish their prioritization. A ranking system for SD-IIoT controllers is formulated using LC-ANP, and experimental validation of this method underscores its effectiveness …


Tensor Z -Transform, Shih Yu Chang, Hsiao Chun Wu Jan 2024

Tensor Z -Transform, Shih Yu Chang, Hsiao Chun Wu

Faculty Publications

The multi-input multioutput (MIMO) systems involving multirelational signals generated from distributed sources have been emerging as the most generalized model in practice. The existing work for characterizing such a MIMO system is to build a corresponding transform tensor, each of whose entries turns out to be the individual z-transform of a discrete-time impulse response sequence. However, when a MIMO system has a global feedback mechanism, which also involves multirelational signals, the aforementioned individual z-transforms of the overall transfer tensor are quite difficult to formulate. Therefore, a new mathematical framework to govern both feedforward and feedback MIMO systems is in crucial …


Fractal Surface Recovery And Self-Healing Contributed To Sustainable Superhydrophobicity: A Review, Yunfei Peng, Zhihang Ma, Xiao Wang, Junru Li, Xinlin Li, Chuanwei Zhang, Tian He, Guoqiang Li, Pengfei Zhang Jan 2024

Fractal Surface Recovery And Self-Healing Contributed To Sustainable Superhydrophobicity: A Review, Yunfei Peng, Zhihang Ma, Xiao Wang, Junru Li, Xinlin Li, Chuanwei Zhang, Tian He, Guoqiang Li, Pengfei Zhang

Faculty Publications

The concept of superhydrophobicity has been widely used after years of theoretical and experimental exploration. Researchers have obtained materials with excellent surface superhydrophobicity for numerous areas (e.g. textiles, paints, and coatings industries), through different design and synthesis methods using low surface energy components (LSECs) and micro/nanohierarchy composite structures. However, the durability of superhydrophobic material surfaces has gradually become a prominent obstacle to restricting applications. In this paper, advances in improving the durability of superhydrophobic surfaces in the past decade are reviewed, covering different schemes for recovering fractal surfaces based on the LSECs and micro/nanocomposite structures. It also presents a balanced …


Electrical Energy Harvesting By Connected Form Stable Phase Change Material Composites, Chengbin Yu, Guoqiang Li Jan 2024

Electrical Energy Harvesting By Connected Form Stable Phase Change Material Composites, Chengbin Yu, Guoqiang Li

Faculty Publications

Over the years, thermoelectric energy harvesting has been becoming a topic of intensive research and thermoelectric power generator has been utilized in various energy harvesting applications. However, a thermoelectric device is required to harvest energy, which has relatively low efficiency and high cost. To overcome such a common problem, the objective of this study is to generate electrical energy without using thermoelectric devices. To this end, an advanced energy harvester composed of two different phase change material composites was explored. It was hypothesized that based on the well-known Seebeck effect, stable electrical energy output would be feasible without a thermoelectric …


Fracture Conductivity Management To Improve Heat Extraction In Enhanced Geothermal Systems, Qitao Zhang, Arash Dahi Taleghani, Guoqiang Li Jan 2024

Fracture Conductivity Management To Improve Heat Extraction In Enhanced Geothermal Systems, Qitao Zhang, Arash Dahi Taleghani, Guoqiang Li

Faculty Publications

The efficiency of an enhanced geothermal reservoir (EGS) depends on the effective circulation of the working fluid through the geothermal formation. To remove the thermal shortcut that leads to thermal short-circuiting in the EGS, we present a method of fracture hydraulic conductivity management and present some practical ways to implement it in the field. The core idea is to correlate the flow resistance in different flow channels with temperature, in order to make uniform heat extraction through each flow path. The presented technique is an adaptive and reversible system and is trying to engineer the fracture system for effective delay …


Subcooled Pool Boiling On Hierarchical Micro- And Nanostructure-Modified Copper Surfaces In Hfe-7100 Dielectric Liquid, Shayan Davani, Bin Zhang, Brendon Doran, Luke Hansen, Mohammad Khan, Mahdi Roodbari, Wen Jin Meng, Arden L. Moore Jan 2024

Subcooled Pool Boiling On Hierarchical Micro- And Nanostructure-Modified Copper Surfaces In Hfe-7100 Dielectric Liquid, Shayan Davani, Bin Zhang, Brendon Doran, Luke Hansen, Mohammad Khan, Mahdi Roodbari, Wen Jin Meng, Arden L. Moore

Faculty Publications

Hierarchical surfaces comprised both microscale and nanoscale structures have been previously studied as a means of targeting multiple length scales to achieve superior pool boiling performance. However, preceding studies have focused almost exclusively on high surface tension working fluids, while technologically important low surface tension fluids have remained largely unexplored. Due to their significantly lower surface tension these liquids tend to push out the air trapped in surface cavities of the heating surface, resulting in fewer nucleation sites compared to the same surface in water at low to moderate superheats. Thus, developing effective surface modification techniques for pool boiling in …


Biomarkers In Cancer Detection, Diagnosis, And Prognosis, Sreyashi Das, Mohan Kumar Dey, Ram Devireddy, Manas Ranjan Gartia Jan 2024

Biomarkers In Cancer Detection, Diagnosis, And Prognosis, Sreyashi Das, Mohan Kumar Dey, Ram Devireddy, Manas Ranjan Gartia

Faculty Publications

Biomarkers are vital in healthcare as they provide valuable insights into disease diagnosis, prognosis, treatment response, and personalized medicine. They serve as objective indicators, enabling early detection and intervention, leading to improved patient outcomes and reduced costs. Biomarkers also guide treatment decisions by predicting disease outcomes and facilitating individualized treatment plans. They play a role in monitoring disease progression, adjusting treatments, and detecting early signs of recurrence. Furthermore, biomarkers enhance drug development and clinical trials by identifying suitable patients and accelerating the approval process. In this review paper, we described a variety of biomarkers applicable for cancer detection and diagnosis, …


The Effects Of Layer Thickness On The Mechanical Properties Of Additive Friction Stir Deposition-Fabricated Aluminum Alloy 6061 Parts, Hamed Ghadimi, Mojtaba Talachian, Huan Ding, Selami Emanet, Shengmin Guo Jan 2024

The Effects Of Layer Thickness On The Mechanical Properties Of Additive Friction Stir Deposition-Fabricated Aluminum Alloy 6061 Parts, Hamed Ghadimi, Mojtaba Talachian, Huan Ding, Selami Emanet, Shengmin Guo

Faculty Publications

Solid-state additive friction stir deposition (AFSD) is a thermomechanical-based additive manufacturing technique. For this study, AFSD was utilized to produce aluminum alloy 6061 (AA6061) blocks with varying layer thicknesses (1 mm, 2 mm, and 3 mm). The mechanical properties were assessed through uniaxial tensile tests and Vickers microhardness measurement, and statistical analysis was employed to investigate differences among data groups. The results revealed that the deposition layer thickness influences tensile properties in the building (Z) direction, while the properties in the X and Y directions showed minor differences across the three AFSD blocks. Furthermore, variations in tensile properties were observed …


Review Of Artificial Neural Networks For Wind Turbine Fatigue Prediction, Alshannaq, Aly Mousaad Aly Jan 2024

Review Of Artificial Neural Networks For Wind Turbine Fatigue Prediction, Alshannaq, Aly Mousaad Aly

Faculty Publications

Wind turbines have emerged as a prominent renewable energy source globally. Efficient monitoring and detection methods are crucial to enhance their operational effectiveness, particularly in identifying fatigue-related issues. This review focuses on leveraging artificial neural networks (ANNs) for wind turbine monitoring and fatigue detection, aiming to provide a valuable reference for researchers in this domain and related areas. Employing various ANN techniques, including General Regression Neural Network (GRNN), Support Vector Machine (SVM), Cuckoo Search Neural Network (CSNN), Backpropagation Neural Network (BPNN), Particle Swarm Optimization Artificial Neural Network (PSO-ANN), Convolutional Neural Network (CNN), and nonlinear autoregressive networks with exogenous inputs (NARX), …


Reliability Analysis Of End Cracking In Continuous Prestressed Concrete Girders, A. M. Okeil, S. Ghimire Jan 2024

Reliability Analysis Of End Cracking In Continuous Prestressed Concrete Girders, A. M. Okeil, S. Ghimire

Faculty Publications

Constructing bridges using precast prestressed concrete girders is extremely popular because of their durability and ease of construction. Establishing continuity between precast girders has its advantages and has been employed in many projects. It causes the development of positive restraint moments at intermediate supports as a result of long-term effects such as creep, shrinkage and thermal gradients. Prestressed concrete girder end cracking occurs if the positive restraint moments exceed the girder’s cracking moment. In this study, the probability of girder end cracking in continuous prestressed concrete bridges is assessed using structural reliability concepts. This study focuses on two bridge configurations …


Field Monitoring Of Bridge Link Slab Performance Under Long-Term And Live Load Effects, A. M. Okeil, M. Canales Jan 2024

Field Monitoring Of Bridge Link Slab Performance Under Long-Term And Live Load Effects, A. M. Okeil, M. Canales

Faculty Publications

Several details to eliminate bridge expansion joints have been proposed, and employed, in bridge construction. Expansion joints are known to require regular maintenance and are the cause of a host of problems including damage to girder ends and substructure components in the vicinity of the joints. The link slab detail is one of these alternatives that eliminates bridge expansion joints without introducing full bridge girder continuity. It has been gaining wide acceptance in North America and is becoming a standard construction detail. A bridge over the Ouachita River in Louisiana, US, employed the link slab detail to connect prestressed concrete …


Instrumentation And Strain Monitoring Of Bfrp Bars In Pedestrian Bridge Deck Link Slab, A. Elsafty, A. Okeil, J. Fletcher, T. Fowler, D. Jones, S. Nolan Jan 2024

Instrumentation And Strain Monitoring Of Bfrp Bars In Pedestrian Bridge Deck Link Slab, A. Elsafty, A. Okeil, J. Fletcher, T. Fowler, D. Jones, S. Nolan

Faculty Publications

Eliminating bridge deck expansion joints is considered a feasible alternative for addressing problems associated with deck joints, which results in reduced maintenance and improved bridge-deck design life. Link slabs introduce partially continuity for bridge girders and improve the seismic performance, wind and storm wave loads resistance. It also leads to lower cost, improved riding quality, and improved structural integrity, and may lead to longer spans. The goal of this study is to monitor the performance of a link slab employed in a pedestrian bridge where Basalt Fiber Reinforced Polymer (BFRP) bars were used for its reinforcement. The pedestrian bridge was …