Physical Sciences and Mathematics Commons^™

Research On Key Construction Monitoring Technology Of Long-Span Skewed Arch And Curved Beam Bridge, Xu Yufeng, Zhang Zhantao, Xie Yunfei, Li Zihui

Journal of China & Foreign Highway

As a new structure with sloping arch ribs and curved main beams,a skewed arch and curved beam bridge markedly differs from the conventional bridge in construction monitoring technology due to its complex structure and prominent spatial effect.To investigate the key technology in construction monitoring,this study took a long-span skewed arch and curved beam bridge as the engineering background and discussed construction process simulation analysis,field monitoring,and parameter identification and adjustment of the bridge.The results show that the plate-shell unit model has higher calculation accuracy and can comprehensively show the stresses in all directions of the bridge compared with the beam element …

Study On Aerodynamic Optimization Of Π-Shaped Cable-Stayed Bridge With Vortex-Induced Vibration In Mountainous Areas, Zeng Min, Liu Hanyun, Mao Na, Chen Baixiang, Han Yan, Li Chunguang

Journal of China & Foreign Highway

Given vortex-induced vibrations of bridges caused by high wind attack angles in mountainous canyons,this study investigated the vortex-induced dynamic characteristics of a Π-shaped steel-concrete composite beam cable-stayed bridge in a mountainous canyon under high wind attack angles based on wind tunnel tests and examined aerodynamic measures for vortex suppression.Firstly,a finite element model of the bridge was established,and the dynamic characteristics of the bridge in both the completed and construction states were analyzed.Subsequently,a 1∶50 scale detailed segment model was designed based on similarity theory to analyze the vortex-induced vibration performance of the original main beam under conventional wind attack angles of …

Wind Tunnel Experiment On Wind-In Duced Vibration Performance Of Arch-Shaped Inclined Steel Bridge Tower In Construction Free-Standing State Using Ae Roelastic Model, Xu Peijun, Deng Fei Yun, Chen Shixuan, Zhang Jiren

Journal of China & Foreign Highway

This paper presented a wind tunnel experimental study on the wind-induced response characteristics of a rectangular-sectioned arch-shaped inclined steel bridge tower during the construction free-standing stage.A 1:50 scaled aeroelastic model was employed to conduct experiments at different wind yaw angles β (0°‒180°).The experimental results indicate:① under the uniform flow field,the tower in its free-standing state does not experience galloping when the bridge ’s wind speed reaches 60 m/s;② under the uniform flow field,the tower exhibits bending vortex-induced vibrations (VIVs ) along the bridge direction or transverse to the bridge direction.However,the amplitudes of the tower top displacements associated with these VIVs …

Analysis Of Mechanical Properti Es Of Integral Jacking Basket Arch Bridge During C Onstruction, Chen Tao, Qiu Jingkui, Wang Ji

Journal of China & Foreign Highway

Taking the Xindian Bridge in Ni ngbo as the background,this paper analyzed the mechanical properties of the integral jacking basket arch bridge during construction.Midas finite element software was used to establish the spatial model of the main bridge,and the deviation of the suspender force and support reaction force of the completed bridge from the design was 1.84% and 1.8%,respectively.The maximum deviation of the displacement calculation of the tie beam at the bridge completion stage was 22 mm,and the maximum deviation of the displacement of the arch rib at the same stage was ‒ 12 mm,which showed that the finite element …

Numerical Simulation Study On Scour Erosion Of Bridge Pile Foundations In Service, Wang Shang, Mi Jiangchuan, Chen Mingtao, Song Dan, Zhang Qiao, Zhang Yong, Wang Weixiao

Journal of China & Foreign Highway

Bridge pile foundations in servic e are subjected to long-term scour erosion caused by sediment-laden water flow,leading to a gradual expansion of the eroded and worn areas.This in turn results in varying degrees of damage to the pile foundation structure and reduces the durability and safety of the bridge.In order to study the impact of scour erosion on bridge pile foundations,this study took the Hanjiang No.1 Bridge in Ankang City as the research object.The ANSYS FLUENT software was used to conduct three-dimensional numerical simulations of the pile foundation and analyze the distribution characteristics and patterns of scour erosion under different …

Internal Force Optimization In Com Pleted Stage And Construction Alignment Control Of Super Long-Span Extradosed Cable-Stayed Bridge, Ba Wenpeng

Journal of China & Foreign Highway

This paper is based on a super long-span extradosed cable-stayed bridge with a main span of 400 m.In view of the technical challenges of high negative bending moment at the quarter point of the bridge and large deformation during the cantilever assembly process in the non-cable area,a systematic solution was proposed in combination with the entire construction process.This paper proposed three schemes:permanent cable over-tensioning,temporary cable setting,and large segment closure.The bending moment ratio (λM) and structural deformation were used as quantitative indicators,and a finite element model was established to compare the three schemes.The results show that all three schemes can improve …

Research On Influence Of Shield Synchronous Grouting Parameters On Surface Deformation, Luo Xu, Zhang Zhaofeng, Fu Helin, Cao Guiqian, Zhao Chuanming

Journal of China & Foreign Highway

In order to determine reasonable grouting parameters,control surface settlement,and reduce the risk of excessive surface settlement caused by irrational synchronous grouting parameters,this study studied the shield tunnel project between maglev T 2 station and maglev T 3 station.A numerical simulation method was adopted to study the influence of grouting pressure,grouting volume,and the elastic modulus of slurry on surface deformation.The results show that the tunnel synchronous grouting has a significant effect on surface settlement control.A greater grouting pressure,equivalent grouting layer thickness,and elastic modulus of slurry mean a smaller surface settlement.As the three parameters increase,the variation range of surface settlement decreases and …

Field Test Research On Optimization Of Smooth Blasting Parameters Based On Drilling Speed, Wang Haitao, Lu Jianghua, Liu Yang, Huang Mingli, Wu Xuan

Journal of China & Foreign Highway

This study aims to address poor adaptability and timeliness in the design of smooth blasting hole parameters in t he past.With the drilling and blasting method-based construction of large cross-section tunnels in Botanggou and Tielugou along the Zunhua‒Qinhuangdao Expressway as the research background and Ⅲ and Ⅳ grade surrounding rocks of porphyritic granite as the research object,statistical regression analysis and theoretical derivation were conducted on the measured data during on-site drilling according to the rock solidity coefficient.Based on this,a simple parameter design method for a smooth blasting layer based on the drilling speed index of an air leg anchor rod …

Study On Reasonable Parameters Of Natural Smoke Exhaust Shafts In Tunnels With Different Longitudinal Slopes, Yang Tao, Zeng Yuekai, Li Peijun, Ren Rui, Deng Min, Zhang Aoyu

Journal of China & Foreign Highway

To obtain the reasonable parameters of a smoke exhaust shaft in a tunnel under different longitudinal slope conditions,the temperature,flow velocity,and smoke exhaust efficiency of the tunnel were taken as indexes,and the numerical model was established by using fire dynamics simulator (FDS ) software to study the influence of the longitudinal slope of the tunnel,shaft width,and shaft length on the ventilation and smoke exhaust in case of a fire.The results show that under the longitudinal slope conditions,with the increase in the shaft width and length,the maximum temperature in the tunnel decreases,and the smoke exhaust efficiency of the shaft increases.However,the influence of …

Intelligent Vehicle Path Tracking Control Integrating Road Adhesion Constraints, Zhang Zhiguo, Wang Pu, Zhang Xinglong, Wang Yan

Journal of China & Foreign Highway

In the field of fault-tolerant control for intelligent vehicle path tracking,the existing methods based on model predictive control (MPC ) have limitations.They often assume that the vehicle model parameters are fixed and ignore the impact of dynamic changes in model parameters,which are caused by factors such as vehicle load changes and external environmental interference,on the path tracking accuracy.When the steering system fails,the front wheel steering angle commands calculated by MPC cannot be directly executed and need to be converted into yaw moment control.Although the existing sliding mode yaw moment control methods have strong robustness,the chattering problem affects the stability and …

Research On Parametric Method Of Highway Bim Based On Digital Delivery, Li Jinlong, Wang Xinnan

Journal of China & Foreign Highway

By analyzing the application points and the current situation of digital delivery in each stage of highway engineering construction,this study found that the lack of parameter management and definition in the modification and refinement process of building information modeling (BIM ) source files at each stage led to difficulties in the splitting and refinement of BIM at each stage and even the need for reconstruction.To this end,a method for strengthening the overall planning of the whole life cycle was proposed.By clarifying the demand for model parameters according to the application points of each stage,a mechanism for parameter reservation and classification …

Reconstruction Plan Of Small-Spacing Interchange Connection Sections On Expressway : A Case Study Of Xinlong‒Gangkou Interchange On Zhongshan‒Jiangmen Expressway, Jie Qiang, Fu Xinsha

Journal of China & Foreign Highway

The plan design for the small-spacing interchange connection on the expressway directly affects operational efficiency and driving safety.To achieve the conversion of traffic flow between different expressways,this study explored the reconstruction plan of the connection section under the condition that the interchange spacing did not meet the Design Specification for Highway Alignment (JTG D20‒2017 ) and investigated two connection schemes,including auxiliary lane and collector-distributor lane by taking the Xinlong –Gangkou interchange of the Zhongshan‒Jiangmen Expressway reconstruction and expansion project as an example.The results show that the auxiliary lane is recommended in consideration of the long-term service level,speed coordination,operational efficiency,and engineering …

Research On Bridge Jacking Decision Based On Carbon Emission Analysis, Zhang Xinmin, Hu Chengze, Gao Hongbo, Yang Yunping, Sun Zhihong, Cao Hongyou

Journal of China & Foreign Highway

To lift the longitudinal section of existing bridges in highway reconstruction and expansion projects due to insufficient under-bridge clearance,this study took the reconstruction of a 32.5 m T-beam bridge in the reconstruction and expansion project of the Guangzhou‒Shenzhen Expressway as the research object.By using a carbon emission factor method,carbon emissions of three reconstruction schemes,including broken-column jacking,conversion of bearing pads into bridge piers,and demolition and reconstruction,were calculated under different lifting heights,and the corresponding construction and installation costs were compared.The results show that when the longitudinal section of the bridge is lifted to a certain height,the economic benefits of the broken-column jacking …

Comparative Study On Differences In Asphalt Pavement Design Between China And Southern Africa, Wang Qing, Lin Yangyang, Yan Hongxiang, Zhao Bin, Xia Moxuan, Li Ning, Si Wei

Journal of China & Foreign Highway

To facilitate the successful implementation of projects in the Southern Africa region and promote the application and internationalization of China ’s standards,this study compared the asphalt pavement design systems,construction materials,design parameters,and structural design methods of both regions based on the main asphalt pavement design specifications currently in use in China and Southern Africa.The results show that among Southern African countries,South Africa has a comprehensive and widely applied standard system,while other Southern African countries adopt more varied and less theoretical standards.In contrast,China ’s standard system is complete and highly practical.Due to differences in regional climates,the selection principles and mechanical requirements for …

Distribution Characteristics Of Internal Distress And Maintenance Decision-Making For Asphalt Pavement Based On Three-Dimensional Ground-Penetrating Radar, Li Xiaohua, Song Liang, Ye Wei, Xie Xiaodong, Yang Jiangang, Gao Jie

Journal of China & Foreign Highway

The distribution characteristics of internal distress in pavement structures and the corresponding maintenance decisions are crucial for improving road performance and extending service life.Based on three-dimensional ground-penetrating radar (3D GPR ) technology,this study investigated the internal distress of a 12-kilometer section of both driving and overtaking lanes of an expressway in Hubei Province.High-resolution images of internal pavement distress were obtained,and milling maintenance decisions were optimized by employing these images and a modular decision-making model.Through an efficient and non-destructive technique,the distribution characteristics of internal pavement distress were analyzed,and potential distress types were identified,providing a scientific basis for maintenance decision-making.Data analysis revealed …

Design Of Champlain Bridge In Canada, Xie Yaning, Zhou Yanfeng, Marwan Nader

Journal of China & Foreign Highway

The Champlain Bridge,an iconic gateway spanning the St.Lawrence River in Montreal,showcases not only the excellence of engineering but also becomes an integral part of the city ’s landscape.With a main span of 240 m,the bridge employs a unique single-pylon harp-shaped double-plane cable-stayed structure.The upper pylon is inspired by a tuning fork in its lateral design,while the upper crossbeam artfully mimics the shape of a bow tie,endowing the bridge with a visual beauty that harmoniously blends elegance and strength.The bridge deck,with a total width of 60 m,was the widest double-plane cable-stayed bridge in the world when it was completed.The typical spans …

Martingale Methods For Structural Change Detection And Feature Attribution In Dynamic Networks, Izhar Ali

Theses and Dissertations

Dynamic networks undergo structural changes when their generative process shifts at a change-point. We need to detect this change-point with minimal delay while identifying its underlying causes. This is an optimization problem of minimizing the expected detection delay while controlling the false alarm probability below a threshold---leading to three critical challenges: non-parametric detection without distributional assumptions, exact feature attribution, and early detection with rigorous false alarm control. We construct additive martingale statistics from multiple graph features using conformal prediction, providing false alarm guarantees via Ville's inequality. Our key theoretical contribution proves the Martingale-Shapley equivalence: each feature's martingale value equals its …

Hypertensive Disorders Of Pregnancy And Perinatal Outcomes: Two Prospective Cohort Studies Of Nulliparous Women In India And Tanzania, Andrea B. Pembe, Pratibha Dwarkanath, Amani Kikula, John Michael Raj, Nandita Perumal Phd, Heavenlight A. Paulo, Rajalakshmi M, Christopher P. Duggan, Honorati M. Masanja, Nandini Chopra, Mary M. Sando, Tinku Thomas, Cara A. Yelverton, Alfa Muhihi, Anura V. Kurpad, Wafaie E. Fawzi, Blair J. Wylie, Christopher R. Sudfeld

Faculty Publications

Introduction Hypertensive disorders of pregnancy (HDP) have been linked with increased risk for maternal and offspring complications in high-income settings. However, in resource-limited settings, studies with robust measurement of HDP, including severity and timing, and perinatal outcomes are limited.

Methods We analysed data from two prospective cohorts of nulliparous women in India (n=10 570 pregnancies) and Tanzania (n=10 299 pregnancies) who were enrolled in calcium supplementation trials and had blood pressure and proteinuria assessments throughout pregnancy and at the time of labour and delivery. Generalised estimating equations were used to assess the relationship between HDP severity categories (gestational hypertension, preeclampsia …

Low Surface Brightness Features Of Edge-On Galaxies In Deep Sky Surveys, Kyle R. Adams

Theses and Dissertations

In this thesis, we present a comprehensive visual analysis of low surface brightness (LSB) structures in edge-on galaxies using two statistically complete samples: 838 galaxies from the SDSS Stripe 82 region (ES82) and 5,745 galaxies from the Edge-on Galaxies in SDSS (EGIS) catalog, both containing galaxies with spectroscopic redshifts out to 𝑧 ∼ 0.2. Using deep imaging data from the SDSS, SDSS Stripe 82, DESI Legacy Imaging Surveys, and the HSC-SSP, we construct RGB and coadded images for comparison and to improve feature detection. Average limiting photometric depth for each survey in the 𝑟 band for the surveys analyzed in …

Technical Communication Instruction Partnership With Engineering Faculty, Ashley S. Mcguire, Michael M. Lipscomb

Libraries Professional Work

Graduate students in STEM fields are often expected to communicate – both in writing and orally – at a professional level by the time they submit their theses and dissertations. Unfortunately, many graduate students lack opportunities to learn how to do that in a STEM setting. An informal review of US programs revealed that many offer writing courses modeled on traditional composition courses, which are not necessarily directed to the needs of STEM students. Further, many of these courses provide a series of isolated learning modules with little continuity or encouragement to revise and in which technological writing assistance is …

Updated Take Estimates Of Marine Turtles In The Guajira Peninsula, Venezuela, Royner Carrasquero-Labarca, Matthew Ware, Jordano Palmar, Daniela Rojas-Cañizales, Héctor Barrios-Garrido

School of Earth, Environmental, & Marine Sciences Faculty Publications

The Guajira Peninsula is one of the most important foraging grounds areas for marine turtles in Venezuela. There, five species converging: the green turtle, hawksbill, loggerhead, leatherback, and olive ridley. The Wayuú indigenous people are inhabits of the Guajira Peninsula. They have a close relationship with these animals, and for generations, they have used these species as subsistence resources. Marine turtle take has always occurred in this area and has historically been high; it is still happening now, but the current extent is unknown. For that reason, we aimed to assess and update the estimate for marine turtles take in …

Applying The Learning Cycle To Introduce Research Practices In General Chemistry Lab, Teresa J. Bixby, Matthew Kubacki, Jasmine Casanova

Chemistry Department Faculty Conferences

CUREs are a great way to engage students in research practices but can be onerous for instructors and teaching assistants to administrate and facilitate. There is added challenge in providing research experiences to students at the introductory level when they have developed limited knowledge and skills. Here we describe a more structured approach that applies the learning cycle to a traditional experiment to allow students to explore the technique, “invent” the parameters for systematic analysis, and apply the technique to a researchable question of their own construction.

Confidence Intervals For The Difference And Ratio Of Two Means From Independent Beta Distribution, Albert Ashong

Electronic Theses and Dissertations

This thesis explores constructing and evaluating confidence intervals for the difference and ratio of means from two independent Beta distributions using Maximum Likelihood Estimation (MLE) and the Wald method. It addresses the limitations of traditional methods due to the unique properties of Beta distributions. Extensive simulation studies assess interval performance based on coverage probability and Average width. The study aims to provide robust tools for statistical analysis in fields where Beta distributions are common, enhancing understanding and application of these methods in various scientific domains. Additionally, these confidence intervals will be applied to real biological data from a Morris Water …

Multiscale Modeling Of Drug-Induced Liver Injury From Organ To Lobule, Alon Malka-Markovitz, Stelian Camara Dit Pinto, Mohammed Cherkaoui, Steven M Levine, Sharmila Anandasabapathy, Gagan K Sood, Sadhna Dhingra, Gao Yujia, John M Vierling, Nicolas R Gallo

Center for Medical Ethics and Health Policy Staff Publications

Drug-induced liver injury poses significant challenges in drug development and in clinical care. This study builds on prior work developing a Human Liver Virtual Twin by creating a Multiscale Computational Fluid Dynamics framework that integrates patient-specific anatomical data to predict acetaminophen-induced liver injury as a demonstration of its capability. The model bridges vascular, lobular, and cellular scales to simulate dynamic blood flow, drug transport, and injury mechanisms that accurately reflect clinically observed spatial heterogeneity. Results demonstrate accurate blood flow dynamics, predictions of hepatocellular damage, and a scalable framework for studying spatial heterogeneity applicable to other hepatic pathologies. This work establishes …

Yb:Ylf Optical Cryocoolers: Saturation Effects, Pump Management, Robust Thermometry, And Novel Architectures, Jackson Kock

Optical Science and Engineering ETDs

Solid-state optical refrigeration using anti-Stokes fluorescence offers a compact, vibration-free route to cryogenic cooling. This dissertation advances ytterbium-doped yttrium lithium fluoride (Yb:YLF) refrigerators, achieving a world record payload cooling temperature of 124 K by addressing key limitations due to absorption saturation. An expanded theoretical model incorporating saturation effects enables accurate predictions of cooling performance under high pump intensities. To improve pump control, a modeling framework for astigmatic Herriott cells was developed, revealing how beam clipping and intensity impact coupling efficiency. A novel fluorescence-based thermometry method was also established, providing accurate, orientation-independent temperature sensing by overcoming reabsorption and crystal orientation. Finally, …

First Insight On The Genesis Of Iron Oxide-Hydroxide Biospeleothems In Rancho Chico Lava Tube, Mexico, Rafael López-Martínez, Elizabeth Solleiro-Rebolledo, Rocio Alcántara-Hernández, Teresa Pi Puig, Sergey Sedov, Daisy Valera Fernández, M. Nayeli Luis-Vargas, Yasmany Lima Vera, Jesús Solé, Ramon Espinasa-Pereña

International Journal of Speleology

Iron is a common element in lava tube systems, typically observed as thin crusts or inferred from the reddish coloration of secondary mineral deposits. In this study, we describe iron oxide-hydroxide biospeleothems discovered in the Rancho Chico Lava Tube, located within the Xalapa Monogenetic Volcanic Field in Mexico. We adopt an integrative approach combining petrography, soil micromorphology, scanning electron microscopy, mineralogy, and 16S rRNA gene metabarcoding. DNA sequencing reveals the presence of microorganisms such as Acidithiobacillus, Gallionella, and members of the Leptospirillaceae family, which may be involved in the oxidation of Fe²⁺ within the lava tube. The source …

A Modern Approach To Classifying Medieval Latin Scripts, Robert L. Lane Jr, Rafia Mirza, Robert Slater

SMU Data Science Review

Paleography, the study of historical handwriting, is essential for preserving societal understanding of cultural, social, and legal frameworks from the past. Medieval manuscripts, often exhibiting refined craftsmanship, present unique challenges to modern readers due to differences in handwriting conventions and the absence of standardized punctuation and spaces. These texts hold valuable insights into the evolution of written communication, literacy, and language development. However, interpreting them requires specialized knowledge and technological solutions. Convolutional Neural Networks (CNNs) can be leveraged to classify scripts, an important step in Historical Document analysis. These models extract and analyze hierarchical features from images, addressing inconsistencies in …

Enhancing News Article Generation With Ai Tools, Adam Ercanbrack, Christopher Johnson, Max Pagan, Nibhrat Lohia

SMU Data Science Review

Abstract. This paper aims to present a comparative analysis of a custom-built AI Journalist Assistant and ChatGPT 4.0 for news article generation. The goal is to evaluate the performance of each model based on accuracy, speed, ethical safeguards, and relevance, particularly in the context of journalism. While ChatGPT is widely used for general-purpose content creation, its reliance on older data and potential for plagiarism presents challenges in the fast-paced, high-stakes world of news reporting. To address these issues, we will design and implement an AI Assistant using Retrieval-Augmented Generation (RAG) techniques, focusing on real-time data access, bias reduction, and plagiarism …

Predictive Modeling Of Colorectal Cancer Risk: Leveraging Health, Demographic, And Socioeconomic Factors For Targeted Screening, Anish Bhandari, Shawn Deng, Michael Olheiser, Robert Slater

SMU Data Science Review

Colorectal cancer (CRC) remains a significant public health concern, affecting millions in the United States and worldwide. This study investigates the risk factors associated with CRC using data from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial and aims to develop predictive models to identify high-risk individuals for targeted screening and increased awareness. The dataset integrates CRC incidence data from the National Cancer Institute with socioeconomic indicators from U.S. Census Bureau, linked by zip code. We employ Logistic Regression and Neural Network models to predict CRC risk, incorporating health, demographic, and socio-economic features. While the results suggest that …

Context-Switch Attacks: Understanding And Mitigating The Threat To Llm Applications, Sydney Holder, Bivin Sadler

SMU Data Science Review

Large Language Models (LLMs) are transforming conversational AI, yet their dependence on prompt-supplied context exposes them to context-switch attacks that covertly steer dialogue toward sensitive or malicious ends. A 70 one-sided conversation transcript evaluation set was constructed spanning various fraudulent scenarios. Each transcript embeds adversarial patterns drawn while preserving natural conversational flow. We introduce a hybrid defense that pairs a BERT-based semantic-drift detector (cosine-similarity threshold = 0.70) with a curated keyword and hack-phrase scanner to counter these threats. In aggregate, the system delivered 100 % recall, intercepting every simulated phishing or data-harvesting attempt. The keyword layer achieved perfect precision, generating …