Digital Commons Network^™

Chaos Game Optimization Method For Weight Minimization Of Steel Truss Structure, Eain Kyi Thar

Chulalongkorn University Theses and Dissertations (Chula ETD)

The research proposes the so-called chaos game optimization (CGO) method to perform the optimal sizing design of steel truss structures under applied loading regimes. The optimization problem aims at the minimization of the total weight (directly related to the cost function) of the designed structure subjected to the constraints describing the intrinsic structural responses complying with limit-state specifications. The CGO approach is based on the underlying chaos theory that establishes the primary patterns as fractals in responses to the systems representing them as self-organized dynamical systems. The fractal is generated as an initial Sierpinski triangle (i.e., search space of solution …

A Study Of Geographic Information System-Based Watershed Processing For Hydrologic Analysis Of Ungauged Watersheds, Philip Adanbe Adalikwu

Electronic Theses and Dissertations

The increasing application of geographic information system (GIS) technology in watershed modeling makes is necessary to further evaluate its impacts on runoff characteristics as a basis for improved hydrologic analysis in ungauged watersheds. Experts in the field of water resources and hydrology have recommended the practice of subdivision when modeling a watershed, and the use of observed data from hydrologically similar watershed to calibrate and validate an ungauged watershed’s model. However, previous studies have failed to adequately address the issues of watershed heterogeneity, spatial and temporal variability in physical parameters, GIS data resolution issues, including artifacts in automated extraction of …

Laboratory Measurements Of Bed Shear Stress In Open Channel Flow And Soil Erosion Rate In Cohesive Soils, Gunnar Schurmann Kern

Electronic Theses and Dissertations

The relationship between soil erosion rate and bed shear stress is an important problem in sediment transport and scour. However, reliable measurements of the soil erosion function are challenging, both in the field and in the laboratory. The objective of this study is to investigate an experimental setup for conducting bed shear stress and soil erosion rate measurements using an open channel flume with a rough bed. These experiments were performed in an A-8 Hydraulic Channel with a fixed gravel bed. The flow discharge was kept constant at 0.158 ft.3/s, and bed shear stress was varied by changing the channel …

An Exploration Of The Application Of Spatial Network Screening Methods On Iowa Rural Road Crashes, Rosanna Maria Novellino Suarez

Electronic Theses and Dissertations

Safety on the roadway system is important due to its usage on mobility and accessibility, especially on rural roads in the state of Iowa. Single vehicle run off road crashes have been increasing in the United States and studies and research has increased due to the concern with those. For this effort, a spatial-temporal method of traffic safety network screening is utilized in order to evaluate the concerning type of crashes in particular locations. The study of single vehicle run off road crashes using the proposed method is important since distributions and clusters of crashes along roadways can be observed …

A Hydrologic Climate Study For An Arid Region, Ali Alsubeai

Electronic Theses and Dissertations

Water is the most precious natural resource in arid regions due to the limitation of water resources, expanding population, and increasing volumes of industrial and domestic waste. The purpose of this research was to evaluate methods to estimate water quantity in an arid region. The research consisted of three separate studies. In the first study, hydrologic models used to estimate water quantity were evaluated for suitability of use in arid regions. Most hydrologic models that have been used in arid regions were originally developed for humid regions. Rainfall events in arid regions can be characterized as short-term, high intense rainstorms …

Ground Movements And Vibrations Caused By Impact Pile Driving Of Prestressed Concrete Piles In Central Florida, Jorge Enrique Orozco Herrera

Electronic Theses and Dissertations, 2020-2023

The process of pile driving has been a commonly used method for the installation of deep foundations in Central Florida due to the soil conditions that consist mainly of medium-dense silty sands. Pile driving can generate large vibration levels that might potentially trigger ground deformations in the surrounding soils and cause damage on nearby structures. Currently, design and construction standards provide guidance in terms of ground vibration levels expected during pile driving and establish vibration thresholds to avoid damage on important infrastructure. However, little insight has been given into the amount of ground deformations that soils experience due to pile …

Modeling Of Crash Risk For Realistic Artificial Data Generation: Application To Naturalistic Driving Study Data, Lauren Hoover

Electronic Theses and Dissertations, 2020-2023

Most safety performance analysis employs cross-sectional and time-series datasets, posing an important challenge to safety performance and crash modification analysis. The traditional safety model analysis paradigm relying on observed data only allows relative comparisons between analysis methods and is unable to establish how well the methods mimic the true underlying crash generation process. Assumptions are made about the data, but whether the assumptions truly characterize the safety data generation in the real world remains unknown. To address this issue, this thesis proposes the generation of realistic artificial data (RAD). In developing a prototype RAD generator for crash data, we mimic …

Combining Multivariate Statistical And Numerical Modeling For Coastal Hazards Analysis, Victor Malagon Santos

Electronic Theses and Dissertations, 2020-2023

Increased population density along the world's coastlines is driven by the wide range of services provided by costal systems, such as transportation, fisheries, trade, and tourism. Despite offering fundamental services, coastal systems are exposed to a range of natural hazards such as riverine and/or coastal flooding, and erosion, thus robust risk analyses are needed to protect coastal ecosystems, infrastructure, and people dwelling in proximity to the shoreline. Numerical and multivariate statistical models have become crucial tools in coastal risk management to support robust risk analyses, and their combined use provides many benefits in the analysis of coastal hazards. This dissertation …

Ground Movements And Nonlinear-Inelastic Response Of Buildings Induced By Excavations In Glacial Clay Deposits, A. Felipe Uribe-Henao

Electronic Theses and Dissertations, 2020-2023

The analysis of ground movements and nonlinear response of buildings induced by excavations in glacial clay deposits is conducted using finite element models built in PLAXIS2D and OpenSees. PLAXIS2D was used to simulate the performance of an urban cofferdam excavation braced with a concrete bracing system. Measured ground movements were compared with the computed response, and the influence of the temperature, installation, and curing effects on the concrete bracing is evaluated. Concrete time-dependent effects contributed to 32% of the maximum lateral wall movements. The numerical studies are expanded in a second finite element analysis to characterize the coupled fluid-solid response …

Safety And Operations Of Urban Arterials Incorporating The Context Classification System, Nada Mahmoud

Electronic Theses and Dissertations, 2020-2023

Urban arterials connect multiple areas in the city and encourage non-motorist activities. Hence, the safety and operations on urban arterials is vital as they improve the mobility of daily commuters and road users. This research aims to facilitate traffic operations on urban arterials by proposing multiple mythological approaches to estimate and predict turning movement counts at signalized intersections using traffic data from adjacent intersections. Further, it aims to improve the safety by developing crash prediction models, identifying the hotspots for multiple crash types, and indicating the factors contributing to operating speed as well as non-motorist crashes. The analyses included tuning, …

Exposure Assessment Of Emerging Contaminants: Rapid Screening And Modeling Of Plant Uptake, Majid Bagheri

Doctoral Dissertations

"With the advent of new chemicals and their increasing uses in every aspect of our life, considerable number of emerging contaminants are introduced to environment yearly. Emerging contaminants in forms of pharmaceuticals, detergents, biosolids, and reclaimed wastewater can cross plant roots and translocate to various parts of the plants. Long-term human exposure to emerging contaminants through food consumption is assumed to be a pathway of interest. Thus, uptake and translocation of emerging contaminants in plants are important for the assessment of health risks associated with human exposure to emerging contaminants. To have a better understanding over fate of emerging contaminants …

Innovative Modeling And Management Of Infrastructure Systems, Engineering And Construction Operations, And Offsite Construction Technology Using Computational Data Analytics, Rayan Hassane Assaad

Doctoral Dissertations

“The construction industry has been facing considerable challenges due to the inadequacy of the traditional methods in executing, managing, and modeling infrastructure and construction projects. While many techniques have been developed to improve the decision-making process in the industry, there is no evidence of sufficient and continuous improvements in the industry’s adoption and implementation of innovative techniques such as new management approaches, modern modeling methods, and emerging computational data analytics. To this end, the goal of this research is to address some of the recent challenges faced in the industry with a focus on infrastructure asset management, construction engineering and …

Model And Data, Equilibrium Of Self-Formed, Single-Thread, Sand-Bed Rivers, Enrica Viparelli, Esther C. Eke

Faculty Publications

This submission contains the following files, also uploaded as Supplementary Information for the manuscript Equilibrium of self-formed, single-thread, sand-bed rivers submitted after major revisions to the AGU journal Geophysical Research Letters.

Excel file with embedded macro Equilibrium_calculator.xlxm, contains the solver of the analytical model presented in the manuscript.

Excel file Equilibrium_results.xlxs contains model data used to generate the plots.

Effectiveness Of Seismic Bearings On A Typical Isolated Two-Column Rc Bridge Pier Located In North Mississippi, Hemant Raj Joshi

Electronic Theses and Dissertations

The 2020 ASCE infrastructure report card has assigned a letter grade of D- for bridges in Mississippi based on poor to fair condition ratings with many approaching the end of their useful service lives. Bridges in northern Mississippi lie up to 100 miles from the New Madrid Fault and fall into the Region 3 Seismic Performance Category defined by AASHTO. The primary objective of this study is to evaluate the performance of commercially available bridge bearings on a common bridge pier type used in northern MS under the combined action of superstructure gravity and lateral seismic loads. The use of …

Quantification Of Climate Variability And Extreme Events In The Great Plains, Angelinah Ntsieng Rasoeu

Electronic Theses and Dissertations

Climate variability and extreme events continue to worsen resulting in significant impacts to society and the environment. Quantifying precipitation variability, streamflow, and extreme events at local scale is crucial for local planning and management due to spatial and temporal precipitation variability which influences streamflow and thus, water resources. This study uses statistical tools to analyze 1895-2019 (125 years) of historical precipitation data to examine how long-term precipitation varies annually, seasonally, and monthly, and create climate classifications. The results show that annual precipitation is increasing linearly over time ranging from 13.2 in (1976) to 43.1 in (2010) and 5 climate classes …

A Speciation Modeling Study Of Heavy Metal Adsorption To Plastic In Municipal Wastewater Treatment Plant Units, Kaitlyn Hague

Electronic Theses and Dissertations

Microplastics are an emerging concern due to their harmful effect to organisms and their ability to facilitate transport of contaminants including heavy metals. Microplastics can enter the environment through wastewater treatment plants, landfill leachate, and littering. Once in the environment microplastics can be distributed throughout rivers, the ocean, and lakes. In order to understand the adsorption of heavy metals to microplastics a geochemical modeling study was completed using Visual Minteq. Lab tests were completed to better understand what constituents are available in wastewater at four different locations: influent, clarifiers, digesters, and effluent. These constituents were then used to observe how …

Intercomparisons Of Three Global Bottom-Up Anthropogenic Emission Inventories: Implications For Air Quality, Halima Salah

Wayne State University Theses

Air pollution from human activities plays an important role in affecting ambient air quality, climate change and human health. To provide changes in global environmental policies to reduce air pollution, emission inventories are critical as they aide in the understanding of air quality impacts across multiple scales. The state-of-the-science global bottom-up anthropogenic emission inventories are the Evaluating the Climate and Air Quality Impacts of Short-Lived Pollutants version 6b (ECLIPSEv6b) for emissions from 1990-2050, Emission Database for Global Atmospheric Research version 5.0 (EDGARv5) for emissions from 1970-2015, and the Community Emissions Data System that was released in April 2021 (CEDS) for …

Editorial: Integrated Water Management For Enhanced Water Quality And Reuse To Create A Sustainable Future, Eldon R. Rene, Veeriah Jegatheesan, Li Shu

Research outputs 2014 to 2021

Safe drinking water and sanitation are very important for the survival of human life. With the rapid proliferation of industries, growth in population and different forms of pollution, i.e. in water, air, soil and sediments, the living environment and the ecosystem is constantly polluted. In this context, integrating different water resources for enhanced water quality and reuse is important to solve the persisting problems and challenges in developing and the developed nations. Integrated water management offers environmental, economic and social benefits because it aims at maximizing the existing resources and prevents further depletion of the ecosystem.

Prediction Of Mean Wave Overtopping At Simple Sloped Breakwaters Using Kernel-Based Methods, Shabnam Hosseinzadeh, Amir Etemad-Shahidi, Ali Koosheh

Research outputs 2014 to 2021

The accurate prediction of the mean wave overtopping rate at breakwaters is vital for a safe design. Hence, providing a robust tool as a preliminary estimator can be useful for practitioners. Recently, soft computing tools such as artificial neural networks (ANN) have been developed as alternatives to traditional overtopping formulae. The goal of this paper is to assess the capabilities of two kernel-based methods, namely Gaussian process regression (GPR) and support vector regression for the prediction of mean wave overtopping rate at sloped breakwaters. An extensive dataset taken from the EurOtop database, including rubble mound structures with permeable core, straight …

Smart Parking Systems: Reviewing The Literature, Architecture And Ways Forward, Can Biyik, Zaheer Allam, Gabriele Pieri, Davide Moroni, Muftah O' Fraifer, Eoin O' Connell, Stephan Olariu, Muhammad Khalid

Computer Science Faculty Publications

The Internet of Things (IoT) has come of age, and complex solutions can now be implemented seamlessly within urban governance and management frameworks and processes. For cities, growing rates of car ownership are rendering parking availability a challenge and lowering the quality of life through increased carbon emissions. The development of smart parking solutions is thus necessary to reduce the time spent looking for parking and to reduce greenhouse gas emissions. The principal role of this research paper is to analyze smart parking solutions from a technical perspective, underlining the systems and sensors that are available, as documented in the …

See-Trend: Secure Traffic-Related Event Detection In Smart Communities, Stephan Olariu, Dimitrie C. Popescu

Computer Science Faculty Publications

It has been widely recognized that one of the critical services provided by Smart Cities and Smart Communities is Smart Mobility. This paper lays the theoretical foundations of SEE-TREND, a system for Secure Early Traffic-Related EveNt Detection in Smart Cities and Smart Communities. SEE-TREND promotes Smart Mobility by implementing an anonymous, probabilistic collection of traffic-related data from passing vehicles. The collected data are then aggregated and used by its inference engine to build beliefs about the state of the traffic, to detect traffic trends, and to disseminate relevant traffic-related information along the roadway to help the driving public make informed …

Pesticide Occurrence And Persistence Entering Recreational Lakes In Watersheds Of Varying Land Uses, Jessica Satiroff, Tiffany Messer, Aaron R. Mittelstet, Daniel D. Snow

Nebraska Water Center: Faculty Publications

Currently little is known of newer pesticide classes and their occurrence and persistence in recreational lakes. Therefore, the objectives of this study were to (1) assess average pesticide concentrations and loadings entering recreational lakes in three mixed land use watersheds throughout the growing season, (2) evaluate pesticide persistence longitudinally within the lakes, and (3) perform an ecotoxicity assessment. Six sampling campaigns were conducted at three lakes from April through October 2018 to measure the occurrence and persistence during pre, middle, and post growing season. Polar organic chemical integrative samplers (POCIS) were placed in streams near lake inlets and monthly samples …

Occurrence Of Arsenite In Surface And Groundwater Associated With A Perennial Stream Located In Western Nebraska, Usa, Arindam Malakar, Rajesh Singh, Jeffrey Westrop, Karrie A. Weber, Christopher N. Elofson, Manish Kumar, Daniel D. Snow

Nebraska Water Center: Faculty Publications

Dissolved arsenic typically results from chemical weathering of arsenic rich sediments and is most often found in oxidized forms in surface water. The mobility of arsenic is controlled by its valence state and also by its association with iron oxides minerals, the forms of which are both influenced by abiotic and biotic processes in aqueous environment. In this study, speciation methods were used to measure and confirm the presence of reduced arsenic species in the surface water of Frenchman creek, a gaining stream that crosses the Colorado- Nebraska border. Selective extraction analysis of aquifer and stream bed sediments shows that …

Optimal Multi-Reservoir System Operations Under Inflow Scenarios In Nam Ngum River Basin, Lao Pdr, Bounhome Kimmany

Chulalongkorn University Theses and Dissertations (Chula ETD)

The Nam Ngum River is one of the main rivers in Lao PDR. Many hydropower projects are currently operated, under construction, and in the planning stage within the Nam Ngum River Basin (NNRB). These hydropower projects are managed by different organizations which could lead to conflict in operation and hinder the achievement of national developments. The main objective of this research is therefore to develop an optimization model for maximizing hydropower production in the NNRB through optimal reservoir operation under the impact of climate change. The potential consequence of maximizing hydropower production that could lead to flooding was also considered …

Crash Analysis And Development Of Safety Performance Functions For Florida Roads In The Framework Of The Context Classification System, Ma'en Al-Omari

Electronic Theses and Dissertations, 2020-2023

Nowadays, technology is employed in many safety applications and countermeasures that would enhance traffic safety by influencing some crash-related factors. Therefore, crash-related factors must be determined for every roadway element by the development of safety performance functions. Safety performance functions (SPF) are employed to predict crash counts at the different roadway elements. Several SPFs have been developed for the various roadway elements based on different classifications such as functional classification and area type. Since a more detailed classification of roadway elements leads to more accurate crash predictions, multiple states have developed new system to categorize roads based on a comprehensive …

The Use Of Physically Based Models And Ensemble Forecasting For Storm Surge Risk Assessment In A Changing Climate, Jeane Camelo

Electronic Theses and Dissertations, 2020-2023

Storm surge has been the deadliest and costliest hurricane induced hazard in the coastal United States. In order to save property and lives, emergency managers must issue advisories guided by numerical models in a timely manner. However, these surge models are highly dependent on weather forecasts which contain uncertainties themselves as hurricanes traverse through the waters before making landfall. This dissertation aims to understand the contribution of uncertainties in hurricane properties, particularly the wind intensity which can contribute to uncertainties in storm surge models. Investigating these properties through numerical modeling is both computationally and time intensive. However by developing a …

Early Wildfire Detection By Air Quality Sensors On Unmanned Aerial Vehicles: Optimization And Feasibility, Doaa Rjoub

Masters Theses

“Millions of acres of forests are destroyed by wildfires every year, causing ecological, environmental, and economical losses. The recent wildfires in Australia and the Western U.S. smothered multiple states with more than fifty million acres charred by the blazes. The warmer and drier climate makes scientists expect increases in the severity and frequency of wildfires and the associated risks in the future. These inescapable crises highlight the urgent need for early detection and prevention of wildfires. This work proposed an energy management framework that integrated unmanned aerial vehicle (UAV) with air quality sensors for early wildfire detection and forest monitoring. …

Collaborative Planning In The Construction Industry: A Holistic Framework For Assessing Collaborative Planning Practices And Predicting Project Performance, Amr Elsayegh

Doctoral Dissertations

"The fragmentation of the construction industry prompted developing novel methods such as collaborative planning, lean construction, advancements in technology, integrated project delivery, and relational contracting. Current research focused on specific facets of collaborative planning without presenting a comprehensive analysis of its factors. As such, the goal of this research is to develop a holistic framework that studies and evaluates collaborative planning practices in construction projects. This research offers significant addition to the body of knowledge through various theoretical and practical contributions. In relation to that, this research developed a comprehensive framework by (1) identifying a comprehensive list of factors influencing …

ระเบียบวิธีการเรียนรู้กลุ่มอนุภาคสำหรับการกำหนดตำแหน่งข้อต่อที่น้อยที่สุด ในการออกแบบบ้านโมดูลาร์สำเร็จรูป, ธมลวรรณ สุวรรณศรี

Chulalongkorn University Theses and Dissertations (Chula ETD)

ที่อยู่อาศัยโมดูลาร์สำเร็จรูปได้รับความนิยมมากขึ้นในหลายประเทศด้วยการก่อสร้างที่รวดเร็วและประหยัดพื้นที่ที่ใช้สำหรับเตรียมการก่อสร้าง เทคโนโลยีการก่อสร้างสำเร็จรูปนี้มีข้อได้เปรียบในด้านความสามารถในการจัดเก็บและสามารถขนส่งไปยังสถานที่ต่างๆ ได้ง่าย ด้วยความหลากหลายของโครงสร้างโครงข้อแข็งทั่วไป ที่อยู่อาศัยโมดูลาร์สำเร็จรูปจะประกอบด้วยชุดแผงเหล็กสำเร็จรูปน้ำหนักเบาที่มีการออกแบบการเชื่อมต่ออย่างแม่นยำ (น็อตและสลักเกลียว และ/หรือ การเชื่อม) ต้นทุนการก่อสร้างและระยะเวลาที่ใช้ในการประกอบติดตั้งมีความสัมพันธ์กับจำนวนของการเชื่อมต่อที่มีการออกแบบไว้ ในงานวิจัยนี้นำเสนอระเบียบวิธีการเรียนรู้กลุ่มอนุภาคอย่างครอบคลุม (Comprehensive Learning Particle Swarm Optimization: CLPSO) ในการหาตำแหน่งข้อต่อที่น้อยที่สุดที่จำเป็นต่อการประกอบที่อยู่อาศัยโมดูลาร์แบบกึ่งแยกส่วนภายใต้แรงกระทำที่กำหนดและข้อกำหนดตามมาตรฐานการออกแบบ AISC-LRFD การเชื่อมต่อต่างๆ ใช้การผสมผสานรูปแบบการเชื่อมต่อที่ถูกออกแบบไว้ห้ารูปแบบโดยกำหนดตำแหน่งที่เป็นไปได้ไว้ล่วงหน้า พฤติกรรมของโครงสร้างจะถูกอธิบายด้วยเงื่อนไขความสอดคล้องของระยะกระจัดที่เปลี่ยนไปของแต่ละองศาเสรี (ในระบบสามมิติ) ที่เชื่อมระหว่างจุดที่เชื่อมต่อแต่ละแผงเหล็ก ระเบียบวิธี CLPSO จะกำหนดตัวแปรเงื่อนไขของการเชื่อมต่อที่จุดต่างๆ ทั้งหมด และทำการหาคำตอบการวางตำแหน่งของการเชื่อมต่อในตำแหน่งต่างๆ ที่เหมาะสมอย่างมีประสิทธิภาพ ทั้งนี้เพื่อนำไปสู่ต้นทุนการก่อสร้างที่ต่ำที่สุด การประยุกต์ใช้ CLPSO ดังกล่าวจะนำเสนอผ่านแบบบ้านพักอาศัยของการเคหะแห่งชาติ

Effects Of Configuration And Operating Conditions On Turbidity Removal Of Jet Clarifier, Ploypailin Romphophak

Chulalongkorn University Theses and Dissertations (Chula ETD)

In water treatment, flocculation creates large and weighty flocs enough to be removed by the downstream processes of sedimentation and filtration. Among the various existing technologies, the jet clarifier is considered as an effective and compact system as it couples flocculation and clarification in a single unit. For the design of jet mixing, much experimental work has been done and many correlations have been proposed. However, these correlations are case specifics, and, to date, there is no comprehensive view for the flocculation aspect. In order to evaluate the performance of the jet clarifier for turbidity removal and understand hydrodynamics to …