Sparse Representation Learning For Temporal Networks, Maxwell Mcneil

Electronic Theses & Dissertations (2024 - present)

Temporal networks arise in many domains including activity of social network users, sensor network readings over time, and time course gene expression within the interaction network of a model organism. Data of this type contains a wealth of prior information such as the connectivity among nodes (e.g., a friendship graph), and prior knowledge of expected temporal patterns (e.g., periodicity). Modeling these temporal and network patterns jointly is essential for state-of-the-art performance in temporal network data analysis and mining. Sparse dictionary encoding is one modeling approach for such underlying patterns. However, most classical approaches consider only one dimension of the data …

Disentangling Cyclic Causality: An Instance-Based Framework For Causal Discovery, Chase A. Yakaboski

Dartmouth College Ph.D Dissertations

Correlation does not imply causation" is one of the fundamental principles taught in science, emphasizing that associations between variables do not necessarily indicate causality. Yet, over the past three decades, extensive research has begun to challenge this perspective by developing sophisticated methods to differentiate causal from correlative relationships. This research suggests that correlations often involve a blend of confounded and causal interactions, which, given certain assumptions, can be disentangled to uncover actionable insights and deepen our understanding of physical, biological, and societal systems.

Accurately discovering causal relationships from data amidst cyclic dynamics remains a challenging open problem in causality research. …

Development Of Probabilistic Dynamic Model Building And Bayesian Machine Learning Approaches, Samuel Oladayo Adeyemo

Graduate Theses, Dissertations, and Problem Reports (ETD)

Abstract

Development of Probabilistic Dynamic Model Building and Bayesian Machine Learning Approaches

Samuel Adeyemo

The recent years have seen a tremendous increase in the use of artificial intelligence (AI) and machine learning (ML) for the development of data-driven mathematical models needed for performing real-time optimization, model-based control, performance optimization, dynamic data reconciliation, and process performance monitoring. However, the development of data-driven models is faced with some challenges including lack of model interpretability, sensitivity of algorithm to noise in training data, limited extrapolation capabilities and violation of conservation laws. Drawing motivation from these existing gaps, this work aims to develop robust …

Investigation Of Space Charge Effects On Co2 Electrocatalytic Reduction On Gd-Doped Ceria Via Scanning Kelvin Probe And Model-Based Bayesian Analysis, Alejandro Mejia

Graduate Theses, Dissertations, and Problem Reports (ETD)

In studying novel energy conversion and storage systems, such as high-temperature electrolysis, numerous underlying fundamental physical processes remain unclear or inadequately understood. Among these, the modeling and comprehension of surface reaction mechanisms, coupled with the intricate effects of space‑charge interfaces, remains an unclear and challenging area of research.

The work of this dissertation involves the development of a 2D finite element analysis model, leveraging the robust MOOSE framework from INL. This model, featuring inhomogeneous defect thermodynamics for near-surface chemistry, formulated through Poisson‑Cahn variational theory, has been exploited for studying the electrocatalytic reduction of CO₂ on gadolinia doped ceria. The …

Data-Driven Modeling Of Oxygen Kinetics In La0.6sr0.4co0.2fe0.8o3−Δ (Lscf) For High-Temperature Reduction Of Co2 In An Electrolysis Cell, Ferron Campbell

Graduate Theses, Dissertations, and Problem Reports (ETD)

Electrolysis systems are critical to several societal applications, particularly energy storage and conversion. Developing these systems requires a detailed knowledge of the chemistry and thermodynamics of the materials used in the electrolysis cell. This work focuses on using embedded scientific machine learning as an efficient way to build an interpretable model for the reaction and transport kinetics in the LSCF electrode, whose performance directly influences the electrolysis system’s performance. The models developed in this study are trained using the publicly available machine learning package, FoKL-GP. This package incorporates a robust Gibbs sampler that employs a forward variable selection process to …

Reducing Food Scarcity: The Benefits Of Urban Farming, S.A. Claudell, Emilio Mejia

Journal of Nonprofit Innovation

Urban farming can enhance the lives of communities and help reduce food scarcity. This paper presents a conceptual prototype of an efficient urban farming community that can be scaled for a single apartment building or an entire community across all global geoeconomics regions, including densely populated cities and rural, developing towns and communities. When deployed in coordination with smart crop choices, local farm support, and efficient transportation then the result isn’t just sustainability, but also increasing fresh produce accessibility, optimizing nutritional value, eliminating the use of ‘forever chemicals’, reducing transportation costs, and fostering global environmental benefits.

Imagine Doris, who is …

Microplate-Like Metal Pyrophosphate Engineered On Ni-Foam Towards Multifunctional Electrode Material For Energy Conversion And Storage, Rishabh Srivastava

Electronic Theses & Dissertations

High clean energy demand, dire need for sustainable development, and low carbon footprints are the few intuitive challenges, leading researchers to aim for research and development for high-performance energy devices. The development of materials used in energy devices is currently focused on enhancing the performance, electronic properties, and durability of devices. Tunning the attributes of transition metals using pyrophosphate (P₂O₇) ligand moieties can be a promising approach to meet the requirements of energy devices such as water electrolyzers and supercapacitors, although such a material’s configuration is rarely exposed for this purpose of study.

Herein, we grow …

Climate Change Impact On Bridge Scour Risk In Ny State: A Gis-Based Risk Analysis Model, Muhammad Hassan Butt

Publications and Research

Bridge scour, the primary cause of bridge failure in the United States, escalates post-severe storms, necessitating effective mitigation. This study employs a GIS-based risk analysis model to assess climate change's impact on bridge scour and associated risks in New York State. Data from the National Bridge Inventory, climate hazard maps, and geospatial data are integrated.

Radiation Exposure Calibration Of The Al2o3:C With Radium-226 And Cesium-137 Using The Osl Method, Selma Tepeli Aydin

All Theses

Optically stimulated luminescence (OSL) dosimetry was utilized to calibrate Al₂O₃:C powder dosimeters, available commercially as the nanoDot® from Landauer Inc., and compare the dosimeter response to radium-226 (²²⁶Ra) and cesium-137 (¹³⁷Cs). The signal from the OSL was quantified using a microSTARii^® OSL reader also produced by Landauer Inc. Dose-response curves were developed for ²²⁶Ra and ¹³⁷Cs experiments (5 dosimeters each) at thirteen absorbed doses. Individual dosimeter response was tracked by serial number. Linear regression analysis was performed to determine if there were significant differences between the intercepts of the …

The Private Pilot Check Ride: Applying The Spacing Effect Theory To Predict Time To Proficiency For The Practical Test, Michael Scott Harwin

Theses and Dissertations

This study examined the relationship between a set of targeted factors and the total flight time students needed to become ready to take the private pilot check ride. The study was grounded in Ebbinghaus’s (1885/1913/2013) forgetting curve theory and spacing effect, and Ausubel’s (1963) theory of meaningful learning. The research factors included (a) training time to proficiency, which represented the number of training days needed to become check-ride ready; (b) flight training program (Part 61 vs. Part 141); (c) organization offering the training program (2- or 4-year college/university vs. FBO); (d) scheduling policy (mandated vs. student-driven); and demographical variables, which …

A Bayesian Network-Based Methodology For Improved Bridge Load Rating And Asset Management, Jeffery Mark Roberts

Dissertations and Theses

From the day a new structure is made available for use, to the day that the structure is no longer able to fulfill an intended purpose, structural safety is a vital interest. Managing a portfolio of structures can be a difficult undertaking for an asset manager, particularly if different types of structures are being maintained. The goal is to manage assets in the most efficient manner which can be influenced by, at a minimum, safety and financial concerns.

A potential tool for an asset manager or owner is the use of Bayesian Networks (BNs). When a BN is used to …

Statistical And Machine Learning Approaches To Describe Factors Affecting Preweaning Mortality Of Piglets, Md Towfiqur Rahman, Tami M. Brown-Brandl, Gary A. Rohrer, Sudhendu R. Sharma, Vamsi Manthena, Yeyin Shi

Department of Agricultural and Biological Systems Engineering: Faculty Publications

High preweaning mortality (PWM) rates for piglets are a significant concern for the worldwide pork industries, causing economic loss and well-being issues. This study focused on identifying the factors affecting PWM, overlays, and predicting PWM using historical production data with statistical and machine learning models. Data were collected from 1,982 litters from the United States Meat Animal Research Center, Nebraska, over the years 2016 to 2021. Sows were housed in a farrowing building with three rooms, each with 20 farrowing crates, and taken care of by well-trained animal caretakers. A generalized linear model was used to analyze the various sow, …

Reducing Uncertainty In Sea-Level Rise Prediction: A Spatial-Variability-Aware Approach, Subhankar Ghosh, Shuai An, Arun Sharma, Jayant Gupta, Shashi Shekhar, Aneesh Subramanian

I-GUIDE Forum

Given multi-model ensemble climate projections, the goal is to accurately and reliably predict future sea-level rise while lowering the uncertainty. This problem is important because sea-level rise affects millions of people in coastal communities and beyond due to climate change's impacts on polar ice sheets and the ocean. This problem is challenging due to spatial variability and unknowns such as possible tipping points (e.g., collapse of Greenland or West Antarctic ice-shelf), climate feedback loops (e.g., clouds, permafrost thawing), future policy decisions, and human actions. Most existing climate modeling approaches use the same set of weights globally, during either regression or …

Feasibility Study Of Pavement Rutting Evaluation Method Based On Driving Vibration, Zhang Jinxi, Wang Peirong, Cao Dandan, Ceng Jingxiang

Journal of China & Foreign Highway

To explore the intelligent detection and monitoring methods of pavement performance, this paper utilized the self-developed driving data collection app to collect vibration acceleration and other data of the pavement during driving, and carried out the feasibility study of evaluating the pavement rutting by driving vibration. Firstly, the collected vibration acceleration data was processed for noise reduction, and the driving vibration characteristics in different working conditions were analyzed. Secondly, seven time domain indicators with high correlation between vibration acceleration and the rutting were extracted as the initial set of indicators, and the seven indicators were downscaled into two independent principal …

Influence Of Shear Deformation On Manufacturing And Erection Alignment, Wang Jin, Chen Changsong

Journal of China & Foreign Highway

This paper aims to study the effect of shear deformation on the manufacturing and erection alignment of main girders of free cantilever erection steel box girder bridges and better design the state of bridge formation state. To this end, it calculated the shear stress coefficient of uniformity of the steel box girder’s cross-section by adopting the finite element method and conducted comparison with the solid model of the plate and shell units of the steel box girder. The results show that the shear stress coefficient of uniformity calculated by finite element software is accurate and reliable. Additionally, simple modeling indicates …

Study On Temperature Gradient Of Long-Span Single-Box Double-Chamber Box Girder Bridge, Yang Wenbin

Journal of China & Foreign Highway

In view of the complex temperature effect of the single-box double-chamber box girders, this paper aimed to carry out the temperature gradient study of box girder cross-sections by employing a short-tower single-box double-chamber cable-stayed bridge with span arrangement of (120+120) m. 21 temperature sensors were installed at the cross-sections of large-mileage closure sections, with the set collection frequency of one time per hour and a wireless collection module for data collection. Meanwhile, temperature observation was carried out for a period of 171 d to obtain the distribution law of the temperature gradient in cross-sections of the closure sections. The study …

Experimental Study On The Influence Of Cantilevered Sidewalk On The Wind Resistance Of A Cable-Stayed Bridge With Pk Girder, Yu Zhenghua

Journal of China & Foreign Highway

Bilateral box steel main girders are widely employed in large-span double-plane cable-stayed bridges. These bridges are characterized by low frequency, small damping, and relatively light mass, and their wind resistance stability is a key problem to be solved in bridge construction. By taking the Pingnan super major cable-stayed bridge with a main span of 636 m on Pingrong Expressway under construction as the research project, this paper built a finite element spatial model of the bridge and analyzed the structural modal characteristics. Meanwhile, it carried out the main girder segmental model of elastically suspended vortex vibration and chatter vibration wind …

Orthogonal Analysis Of Influential Factors In Construction Of Portal Pier Foundations Adjacent To Existing Railway, Li Minghua, Feng Jiahui, Han Wenjing

Journal of China & Foreign Highway

To study the influencing factors of portal pier foundation construction adjacent to existing railway, this paper adopted the orthogonal test method based on numerical simulation to study the influence of five factors on the existing railway, including the length of bored piles, construction sequence of bored piles, excavation depth of foundation pits of the bearing platform, length of steel sheet piles, and number of steel sheet piles. The results show that during the bored pile construction stage, the most important factor is the construction sequence of bored piles. Meanwhile, during the stage of foundation pit excavation and substructure construction, the …

Optimization Design Of Highway Tunnel Inner Contour Based On Simu Lated Annealing Algorithm, Zhang Qingwei

Journal of China & Foreign Highway

To optimize the inner contour design of road tunnels, this paper regarded the inner contour design of a road tunnel as an optimization problem in certain conditions. By taking the area optimization as the objective, it introduced the simulated annealing algorithm to solve the problem based on the calculation model building of the inner contour of a single-centered circle with an inverted arch, with a program written for verification and analysis. The results show that the optimization design scheme is feasible and can provide an idea way for the inner contour design of road tunnels.

Comparison Of Specifications For Highway Safety Audi Ts Of China ， The United States ， And Australia, Li Jie, Han Huanhuan, Li Jia, Ren Yabo, Gong Ruiming

Journal of China & Foreign Highway

Traffic safety is one of the three major problems of transportation. To build a transportation power, China has proposed the call of “facilitating the transportation development from pursuing the speed and scale to paying more attention to quality and safety”, and improving the audit specifications of road safety is an important basis for increasing the transportation safety level. This paper firstly introduced the background where China, the United States and Australia issued the audit specifications of road safety, and then compared the differences between the three countries in the aspects of the audit process for road safety, audit indexes and …

Research On A Hub Interchange Scheme Under Special Terrain Conditions, Wang Jie, He Yajun

Journal of China & Foreign Highway

By combining the study process and conclusion of the interchange scheme of the Lugao hub as an important node of G4216 Jinyang-Ningnan Expressway Project, this paper discussed the ideas and methods of selecting the hub interchange shape under complex terrains and high functional requirements. It aimed to provide certain references for the design of hub interchange schemes in special Y-shaped terrain conditions. The Lugao hub interchange location is deeply cut by the Jinsha River and its branches, with narrow valley bottoms, extremely steep cross slopes, and harsh engineering construction conditions. Meanwhile, in the limited space, the specific requirements of the …

Structure Design Of Platform For Construction Of Inclined Pile Foundation On The Water Under Complex Hydrogeology Conditions, Cheng Tao, Fu Su, Deng Songtao

Journal of China & Foreign Highway

Based on the design of the pile foundation construction platform for the Yushan water intake in Daishan Port, this paper introduced the adoption of the support system combining the steel pile casing and steel pipe piles in complex hydrogeological conditions. Most of the pile foundations feature small embedded length and are inclined piles with weak lateral rigidity, and they cannot resist the horizontal loads such as wind-wave-current during the typhoon period. Therefore, this paper introduced several measures taken to improve the overall lateral stability of the platform. The first measure is to improve the boundary conditions of pile foundations by …

Study On Stability Analysis And Treatment Of A Expressway Landslide, Huang Hongchao

Journal of China & Foreign Highway

In highway construction of mountainous areas, landslides are easily triggered due to the complex geological conditions, thereby causing serious economic loss and even casualties. Therefore, the study of landslide treatment schemes has caught increasingly more attention from scholars. By taking the giant landslide treatment on a highway of southeastern Yunnan as an example, this paper analyzed the process and cause of giant landslide formation, and then conducted inverse calculations to determine the stability analysis parameters of landslides via combining the topography and geology and slope state before and after slope excavation. Finally, according to the calculation results of the residual …

Discussion On Treatment Scheme Of Soft Foundation Based On Cooperative Deformation Of Roadbed And Frame Structure, Liu Jizhong, Chen Kai, Yang Fengyu

Journal of China & Foreign Highway

In view of insufficient consideration of cooperative roadbed and structure deformation, by taking the soft foundation with frame structures in the fill roadbed as the research object, this paper adopted Midas GTS NX finite element analysis software to simulate the pavement settlement and plastic zone distribution of the soft foundation treated by cast-in-place piles. Considering that the stiffness difference between the roadbed and the frame structure can easily result in pavement cracking, a variable stiffness composite foundation treatment optimization scheme was proposed. This scheme coordinated the cooperative settlement and deformation of the roadbed and frame structure, and prevented the development …

Research On Effect Of Structural System On Static And Dyn Amic Stiffness Of Large-Span And Narrow Suspension Bridges, Song Songke, He Jiayong, Chen Qian, Du Taoming, Li Yongle, Yu Chuanjin

Journal of China & Foreign Highway

Large-span and narrow suspension bridges featuring flexible structures and low overall stiffness have prominent wind resistance problems. Structural static and dynamic stiffness is the basic parameter for wind resistance of long-span bridges. By taking a large-span and narrow suspension bridge as the research project, this paper comparatively analyzed the effects of parameters such as stiffened girder stiffness, main cable span ratio, main cable spacing, and lifting point width on the static and dynamic stiffness based on the theory of spatial cable segmental suspension lines and three-dimensional finite element models of bridges under multi-working condition systems. The results show that the …

Risk Assessment Calculation Of Layered Surrounding Rock Tunnel Based On Combination Weight-Eahp-Ncm Model Theory, Yang Yongbin, Wang Qing, Wang Yijun, Gao Weizheng, Li Yongliang

Journal of China & Foreign Highway

To accurately assess and calculate the structural stability of layered surrounding rock tunnels during construction, this paper firstly constructed a risk assessment index system for layered surrounding rock tunnels based on the consideration of factors of hydrogeology, structural surfaces, engineering, external forces, and topography and geomorphology. Based on the Delphi method (DELPHI) and entropy weight method (EWM), the combination of indicators was assigned. Based on the typical event samples and the mining of classical domains-joint domains of the assessment system, the extension analytic hierarchy process calculation model (EAHP) and normal cloud computing model (NCM) were built to assess the stability …

Study On Low Temperature Performance Of Asphalt Mixture Under Salt Freezing Condition, Song Yunlian, Gao Pan, Jiang Yu

Journal of China & Foreign Highway

To investigate the ice-melting ability of snow-melting agents and the effect of different salt freezing conditions on low temperature performance of asphalt mixtures, this paper carried out the ice-melting ability test, beam bending test and beam bending creep test. The results show that under the temperature of -20℃ and concentration 30% or more of the snow-melting agent, the ice can be melted. However, the melting ice quality is small. In terms of melting ice quality, the melting ability of the P-type snow-melting agent is better than that of the H-type snow-melting agent. Under the temperature of -10‒0℃, the recommended concentration …

Analysis Of Light Reflection And Automobile Exhaust Degradation Effect Of Asphalt Pavement Coating, Shang Wenyong, Zhou Zheng, Chen Jun

Journal of China & Foreign Highway

To compare the light reflection and exhaust degradation effect of common road coating fillers, this paper prepared three kinds of road surface coatings with Nano-TiO2, Nano-ZnO, and Micro-TiO2 as fillers respectively. Meanwhile, the reflectivity tests of the coatings with different mixing contents of fillers were conducted by adopting a self-developed light reflectivity tester to determine the optimal mixing content of fillers. Under the optimal mixing content of fillers, the reflectivity of three kinds of coating asphalt mixtures was tested to compare the light reflectivity effect of Nano-TiO2, Nano-ZnO and Micro-TiO2. Additionally, a self-developed exhaust concentration analyzer was utilized to test …

Study On Effect Of Nanomodified Additives On Properties Of Concrete Mixtures During Winter Season, Li Yulin, Liang Hongjie, Liang Junlin, Rong Hongliu, Yang Xiaolong

Journal of China & Foreign Highway

To solve the difficult placement of small structures on highways caused by the decreasing workability of cement concrete construction in winter seasons, this paper developed a nanomodified additive to investigate its effect on the performance of cement concrete. Sulfonate naphthaleneformaldehyde (SNF), nanoSiO2, rosin soap (WSR) and sodium nitrate (NaNO3) were formulated into a variety of additives in different ratios and mixing contents to prepare cement concrete, with the fluidity, segregation and compressive strength studied. The results show that the optimal ratio (mass) of nanomodified additives is SNF:0.4%, nanoSiO2:0.1%, WSR:0.05%, and NaNO3:4.0%. The fluidity, segregation and compressive strength of the concrete …

Study On Theoretical Relationship Between Acceleration Of Vehicle Suspension And International Roughness Index, Lv Wenjiang, Zhang Zhen

Journal of China & Foreign Highway

The international roughness index (IIRI) has become one of the most widely employed indexes to characterize the surface roughness. However, there are still some problems in the current research on the calculation of this index by adopting vertical acceleration data of vehicles. For example, the influence of vehicle suspension parameters on the test results is not sufficiently taken into account, and the applicability of regression analysis equations between vehicle acceleration and this index is low. This paper studied a method of determining this road surface roughness index with the suspension parameters of the test vehicle considered. The actual road tests …