Engineering Commons^™

Modeling Overdraft-Driven Nitrate Transport In Shallow Wells For Mitigation And Scenario Planning, Jonathan Cronk

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

In Nebraska, average nitrate concentrations in groundwater have doubled since 1974, making water quality management more important than ever. As droughts, heat waves, and floods become more common climate events, understanding their impacts will be necessary to make informed management decisions. Emerging literature describes that drought correlates to an increase in the concentration of nitrate-N at domestic and irrigation wells, however the relative contributions of the mechanisms thought to be responsible is currently unknown.

This research assessed the impact of recharge and pumping rate changes as two mechanisms affecting nitrate-N concentration during drought, assessed the relationship between well depth and …

On The Use Of High-Frequency Surface Wave Oceanographic Research Radars As Bistatic Single-Frequency Oblique Ionospheric Sounders, Stephen R. Kaeppler, Ethan S. Miller, Daniel Cole, Teresa Updyke

CCPO Publications

We demonstrate that bistatic reception of high-frequency oceanographic radars can be used as single-frequency oblique ionospheric sounders. We develop methods that are agnostic of the software-defined radio system to estimate the group range from the bistatic observations. The group range observations are used to estimate the virtual height and equivalent vertical frequency at the midpoint of the oblique propagation path. Uncertainty estimates of the virtual height and equivalent vertical frequency are presented. We apply this analysis to observations collected from two experiments run at two locations in different years, but utilizing similar software-defined radio data collection systems. In the first …

Raising Dielectric Permittivity Mitigates Dopant-Induced Disorder In Conjugated Polymers, Meenakshi Upadhyaya, Michael Lu-Díaz, Subhayan Samanta, Muhammad Abdullah, Keith Dusoe, Kevin R. Kittilstved, Dhandapani Venkataraman, Zlatan Akšamija

Electrical and Computer Engineering Faculty Publication Series

Conjugated polymers need to be doped to increase charge carrier density and reach the electrical conductivity necessary for electronic and energy applications. While doping increases carrier density, Coulomb interactions between the dopant molecules and the localized carriers are poorly screened, causing broadening and a heavy tail in the electronic density-of-states (DOS). The authors examine the effects of dopant-induced disorder on two complimentary charge transport properties of semiconducting polymers, the Seebeck coefficient and electrical conductivity, and demonstrate a way to mitigate them. Their simulations, based on a modified Gaussian disorder model with Miller-Abrahams hopping rates, show that dopant-induced broadening of the …

A Novel Path Loss Forecast Model To Support Digital Twins For High Frequency Communications Networks, James Marvin Taylor Jr

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

The need for long-distance High Frequency (HF) communications in the 3-30 MHz frequency range seemed to diminish at the end of the 20th century with the advent of space-based communications and the spread of fiber optic-connected digital networks. Renewed interest in HF has emerged as an enabler for operations in austere locations and for its ability to serve as a redundant link when space-based and terrestrial communication channels fail. Communications system designers can create a “digital twin” system to explore the operational advantages and constraints of the new capability. Existing wireless channel models can adequately simulate communication channel conditions with …

Using A Balloon-Launched Unmanned Glider To Validate Real-Time Wrf Modeling, Travis J. Schuyler, S. M. Iman Gohari, Gary Pundsack, Donald Berchoff, Marcelo I. Guzman

Chemistry Faculty Publications

The use of small unmanned aerial systems (sUAS) for meteorological measurements has expanded significantly in recent years. SUAS are efficient platforms for collecting data with high resolution in both space and time, providing opportunities for enhanced atmospheric sampling. Furthermore, advances in mesoscale weather research and forecasting (WRF) modeling and graphical processing unit (GPU) computing have enabled high resolution weather modeling. In this manuscript, a balloon-launched unmanned glider, complete with a suite of sensors to measure atmospheric temperature, pressure, and relative humidity, is deployed for validation of real-time weather models. This work demonstrates the usefulness of sUAS for validating and improving …

A Self-Organized Learning Model For Anomalies Detection: Application To Elderly People, Nicolas R. Verstaevel, Jean-Pierre George, Carole Bernon, Marie-Pierre Gleizes

SMART Infrastructure Facility - Papers

In a context of a rapidly growing population of elderly people, this paper introduces a novel method for behavioural anomaly detection relying on a self-organized learning process. This method first models the Circadian Activity Rhythm of a set of sensors and compares it to a nominal profile to determine variations in patients' activities. The anomalies are detected by a multi-agent system as a linear relation of those variations, weighted by influence parameters. The problem of adaptation to a particular patient then becomes the problem of learning the adequate influence parameters. Those influence parameters are self-adjusted, using feedback provided at any …

A Dynamic Behavioural Traffic Assignment Model With Strategic Agents, Johan Barthelemy, Timoteo Carletti

SMART Infrastructure Facility - Papers

Foresee traffic conditions and demand is a major issue nowadays that is very often approached using simulation tools. The aim of this work is to propose an innovative strategy to tackle such problem, relying on the presentation and analysis of a behavioural dynamic traffic assignment. The proposal relies on the assumption that travellers take routing policies rather than paths, leading us to introduce the possibility for each simulated agent to apply, in real time, a strategy allowing him to possibly re-route his path depending on the perceived local traffic conditions, jam and/or time already spent in his journey. The re-routing …

Railnet: A Simulation Model For Operational Planning Of Rail Freight, Guillaume Michal, Nam N. Huynh, Nagesh Shukla, Albert Munoz, Johan Barthelemy

SMART Infrastructure Facility - Papers

In many rail networks, infrastructure constraints force the shared usage of lines between passenger and freight movements. Scheduling additional freight movements around existing passenger services and peak traffic based curfews presents significant challenges to commodity industries eager to increase export volumes. This paper addresses the problem of inserting additional freight movements in a constrained railway network. To this end, a railway operations planning model was developed to simulate and insert feasible rail movements in a non-periodic timetable. The simulation modelling platform developed in this paper is called RailNet, which simulates the existing railway network constraints and is capable of adding …

Individual-Level Simulation Model For Cost Benefit Analysis In Healthcare, Nagesh Shukla, Vu Lam Cao, Van Hoang Phuong, Marian D. Shanahan, Alison Ritter, Pascal Perez

SMART Infrastructure Facility - Papers

Illicit drug use creates significant burden at societal, family and personal levels. Every year substantial resources are allocated for treatment and the consequences of illicit drug use in Australia and around the world. Heroin is one of the major forms of illicit drugs. Several independent heroin treatment strategies or interventions exist and state-of-the art research demonstrates their efficacy and relative costeffectiveness. However, assessing total potential gains and burden from providing all treatment interventions or varying the mix of heroin treatments has never been attempted. This paper proposed an individual-level simulation model (ISM) which addresses net social benefit over a lifetime …

Case Study: A Model Based Systems Engineering (Mbse) Framework For Characterising Transportation Systems Over The Full Life Cycle, William R. Scott, Richard Fullalove, Gary Arabian, Allan P. Campbell

SMART Infrastructure Facility - Papers

Development of transport infrastructure has significant challenges including acquisition lag, phased evolution, multiple disparate stakeholders and environment-specific issues. The Asset Standards Authority (ASA) at TfNSW is introducing MBSE to address these challenges. Instrumental to the introduction is the development of a framework that structures the available data and provides guidance and traceability between the data sets. This framework combines the enterprise-level drivers with the lower level drivers such as standards to outline a generic conceptual design for a transport system. This conceptual design is then used to guide future system development. The outcome is future project information based on greater, …

A Stochastic And Flexible Activity Based Model For Large Population Application To Belgium, Johan Barthelemy, Philippe L. Toint

SMART Infrastructure Facility - Papers

The VirtualBelgium project aims at developing an understanding of the evolution of the Belgian population using agent-based simulations and considering various aspects of this evolution such as demographics, residential choices, activity patterns, mobility, etc. This simulation is based on a validated synthetic population consisting of approximately 10,000,000 individuals and 4,350,000 households located in the 589 municipalities of Belgium. The work presented in this paper focuses only on the mobility behaviour of such large populations and this is simulated using an activity-based approach in which the travel demand is derived from the activities performed by the individuals. The proposed model is …

Microscopic Model For Exchange Bias From Grain-Boundary Disorder In A Ferromagnet/Antiferromagnet Thin Film With A Nanocrystalline Microstructure, David L. Cortie, A G. Biternas, R W. Chantrell, Xiaolin Wang, Frank Klose

Australian Institute for Innovative Materials - Papers

Monte Carlo spin simulations were coupled to a Voronoi microstructure-generator to predict the magnitude and behavior of exchange bias in a ferromagnet/antiferromagnet (AF) thin film bilayer with a nanocrystalline microstructure. Our model accounts for the effects of irregular grain-shapes, finite-sized particles, and the possible presence of local random-fields originating from the antiferromagnet's grain-boundary regions. As the grain-boundary represents a crystal-structure distortion, we model the local effect on the exchange constants in the Gaussian approximation which can cause regions resembling a spin glass confined to an unusual 2D topology. Although an ensemble of completely disconnected AF grains isolated by non-magnetic barriers …

Modelling The Rejection Of N-Nitrosamines By A Spiral-Wound Reverse Osmosis System: Mathematical Model Development And Validation, Takahiro Fujioka, Stuart J. Khan, James A. Mcdonald, Annalie Roux, Yvan Poussade, Jorg E. Drewes, Long D. Nghiem

SMART Infrastructure Facility - Papers

A mathematical model was developed based on the irreversible thermodynamic principle and hydro- dynamic calculation to predict the rejection of N-nitrosamines by spiral-wound reverse osmosis (RO) membrane systems. The developed model is able to accurately describe the rejection of N-nitrosamines under a range of permeate flux and system recovery conditions. The modelled N-nitrosamine rejections were in good agreement with values obtained experimentally using a pilot-scale RO filtration system. Simulation from the model revealed that an increase in permeate flux from10 to 30L/m2h led to an increase in the rejection of low molecular weight N-nitrosamines such as N-nitrosodimethylamine (NDMA) (from31% to …

A Model Based Study Of Concept Development For Hospital Wayfinding To Improve Operational Efficiency, Peter Peter Campbell, William R. Scott

SMART Infrastructure Facility - Papers

No abstract provided.

Sensor Selection And Integration To Improve Video Segmentation In Complex Environments, Adam R. Reckley, Wei-Wem Hsu, Chung-Hao Chen, Gangfeng Ma, E-Wen Huang

Civil & Environmental Engineering Faculty Publications

Background subtraction is often considered to be a required stage of any video surveillance system being used to detect objects in a single frame and/or track objects across multiple frames in a video sequence. Most current state-of-the-art techniques for object detection and tracking utilize some form of background subtraction that involves developing a model of the background at a pixel, region, or frame level and designating any elements that deviate from the background model as foreground. However, most existing approaches are capable of segmenting a number of distinct components but unable to distinguish between the desired object of interest and …

Sector Expansion And Elliptical Modeling Of Blue-Gray Ovoids For Basal Cell Carcinoma Discrimination In Dermoscopy Images, Pelin Guvenc, Robert W. Leander, Serkan Kefel, William V. Stoecker, Ryan K. Rader, Kristen A. Hinton, Sherea Monica Stricklin, Harold S. Rabinovitz, Margaret C. Oliviero, Randy Hays Moss

Chemistry Faculty Research & Creative Works

Background: Blue-gray ovoids (B-GOs), a critical dermoscopic structure for basal cell carcinoma (BCC), offer an opportunity for automatic detection of BCC. Due to variation in size and color, B-GOs can be easily mistaken for similar structures in benign lesions. Analysis of these structures could afford accurate characterization and automatic recognition of B-GOs, furthering the goal of automatic BCC detection. This study utilizes a novel segmentation method to discriminate B-GOs from their benign mimics.

Methods: Contact dermoscopy images of 68 confirmed BCCs with B-GOs were obtained. Another set of 131 contact dermoscopic images of benign lesions possessing B-GO mimics provided a …

Levetiracetam-Loaded Biodegradable Polymer Implants In The Tetanus Toxin Model Of Temporal Lobe Epilepsy In Rats, Amy J. Halliday, Toni E. Campbell, Timothy S. Nelson, Karen J. Mclean, Gordon G. Wallace, Mark J. Cook

Australian Institute for Innovative Materials - Papers

Approximately one-third of people with epilepsy receive insufficient benefit from currently available anticonvulsant medication, and some evidence suggests that this may be due to a lack of effective penetration into brain parenchyma. The current study investigated the ability of biodegradable polymer implants loaded with levetiracetam to ameliorate seizures following implantation above the motor cortex in the tetanus toxin model of temporal lobe epilepsy in rats. The implants led to significantly shorter seizures and a trend towards fewer seizures for up to 1 week. The results of this study indicate that drug-eluting polymer implants represent a promising evolving treatment option for …

Departure Time Choice Analysis Using Ordered Response Probit Model: Journey To Work Trip In Dhaka City Of Bangladesh, Ahm Mehbub Anwar

SMART Infrastructure Facility - Papers

No abstract provided.

A Financial Impact Assessment Of Ld 1725: Stream Crossings, New England Environmental Finance Center, Muskie School Of Public Service

Water

This report looks at the potential financial impact of LD 1725 on the estimated 30,000 stream crossings in the State of Maine that would be affected by the law. Our research for this report included the analysis of nearly 2000 stream crossings and the data collection necessary for the development of extensive stream crossing replacement cost models. We found that the 1.2 bankfull requirements in LD 1725 would result in a 75% ‐ 250% increase in structure widths for stream crossing projects across the state. An upsize of this magnitude would increase the cost of replacing stream crossings statewide by …

A Financial Impact Assessment Of Ld 1725: Stream Crossings (Presentation), New England Environmental Finance Center, Muskie School Of Public Service

Water

This report looks at the potential financial impact of LD 1725 on the estimated 30,000 stream crossings in the State of Maine that would be affected by the law. Our research for this report included the analysis of nearly 2000 stream crossings and the data collection necessary for the development of extensive stream crossing replacement cost models. We found that the 1.2 bankfull requirements in LD 1725 would result in a 75% ‐ 250% increase in structure widths for stream crossing projects across the state. An upsize of this magnitude would increase the cost of replacing stream crossings statewide by …

Culvert Material Cost Comparison, New England Environmental Finance Center

Water

The following tables provide a detailed look at the role that culvert material and culvert diameter play in the overall cost of a culvert replacement project.

Construction Cost Models, Barry Dikeman

Economics and Finance

The following are a series of cost estimate models similar in format to a typical engineer’s estimate that were developed in support of our financial impact assessment report for LD 1725. The models us current material costs, labor costs, and equipment costs for the region to provide a comparative cost analysis of seven culvert replacement scenarios. The models provide information about what the cost impact of LD 1725 would be for typical culvert replacements in Maine. However, due to the inherent restrictions of the cost modeling framework we were not able to include the abundance of variables that would be …

A Spatial Agent-Based Model To Explore Scenarios Of Adaptation To Climate Change In An Alpine Tourism Destination, Stefano Balbi, Pascal Perez, Carlo Giupponi

SMART Infrastructure Facility - Papers

A vast body of literature suggests that the European Alpine region may be one of the most sensitive to climate change impacts. Adaptation to climate change of Alpine socioecosystems is increasingly becoming an issue of interest for the scientific community while the people of the Alps are often unaware of or simply ignore the problem. ClimAlpTour is a European research project of the Alpine Space Programme, bringing together institutions and scholars from all countries of the Alpine arch, in view of dealing with the expected decrease in snow and ice cover, which may lead to a rethinking of tourism development …

Intelligent Negotiation Behaviour Model For An Open Railway Access Market, S K. Wong, T K. Ho

SMART Infrastructure Facility - Papers

In an open railway access market, the provisions of railway infrastructures and train services are separated and independent. Negotiations between the track owner and train service providers are thus required for the allocation of the track capacity and the formulation of the services timetables, in which each party, i.e. a stakeholder, exhibits intelligence from the previous negotiation experience to obtain the favourable terms and conditions for the track access. In order to analyse the realistic interacting behaviour among the stakeholders in the open railway access market schedule negotiations, intelligent learning capability should be included in the behaviour modelling. This paper …

An Ontology-Based Simulation Model Exploring The Social Contexts Of Psychostimulant Use Among Young Australians, Pascal Perez, Anne Dray, Paul Dietze, David Moore, Rebecca Jenkinson, Christine Siokou, Rachael Green, Susan L. Hudson, Lisa Maher, Gabriele Bammer

SMART Infrastructure Facility - Papers

The principal anthropogenic factors driving reef degradation have been known for years, if not decades. Overfishing, sedimentation and nutrient loads are just some of the key impacts of human activities in and around reef communities. Therefore, the future of reefs does not rely on generating new knowledge, but rather on implementing and integrating the knowledge we already have. This will require creating effective links between researchers, managers and communities to promote mutual learning, negotiation and collaborative action for reef management. Combining agent-based models and role-play games, through a technique known as Companion Modelling (ComMod), creates a dynamic and interactive setting …

A Task Model Of Software Intensive Acquisitions: An Integrated Tactical Avionics System Case Study, Ricardo Peculis, Derek Rogers, Peter Campbell

SMART Infrastructure Facility - Papers

The acquisition of complex software intensive systems is fraught with significant risks and often incurs schedule delays, cost overruns and reduced functionality when the product is finally delivered. This paper presents a model to assess the effectiveness of software intensive acquisitions, founded on the premise that the solution depends on a series of transformations that transform input products in one domain into output products in another domain. Transformations are performed by people, and require knowledge and skills pertinent to both input and output domains. Ideally, products should be transformed without distortions resulting into the desirable solution. In reality, distortions occur …

Towards An Integrated Model Of Enterprise Systems, Grace A. Kennedy, C E. Siemieniuch, M A. Sinclair

SMART Infrastructure Facility - Papers

An enterprise system consists of a number of components or building blocks. It is common to use views or models of the enterprise that contain a selection of these components (dependent on the intended usage of the model). The premise is that if these views are considered systems in their own right then the total enterprise system is actually a system‐of‐systems. Difficulty arises however when the boundaries between the systems overlap ‐ it is therefore necessary to have an integrated model of the total enterprise that can cope with these overlaps and hence interactions between the systems. Within this paper …

Model State Land Use Legislation For New England, New England Environmental Finance Center, Muskie School Of Public Service

Legislation

Sprawl is neither the ordained nor the inevitable outcome upon the New England landscape. A coordinated response to sprawl by the public and private sectors is possible, and could dramatically improve land use patterns and reduce the cost of local government. For the New England states, such a response would include, among other elements, legislation to eliminate existing gaps in the land use laws of each state – gaps that presently encourage or sanction sprawling development. It would also include incentives for municipalities to think beyond their borders and to act with greater efficiency and effect. It is the purpose …

The Development Of Relationships Between Constituent Concentrations And Generic Hydrological Variables, Carmen T. Agouridis, Dwayne R. Edwards

Biosystems and Agricultural Engineering Faculty Publications

The collection and analysis of samples from storm events constitutes a large portion of the effort associated with water quality research. Estimating concentrations or loads from these events is often difficult. The equipment necessary to analyze the samples and the required laboratory resources are typically significant expenses incurred by the researcher. One potential method to reduce these costs is through the development of generic relationships between concentrations and easily measured variables such as dimensionless flow rate or time. The benefits recognized from such an effort include a reduction in the number of required samples, resulting in a reduction in cost. …

Creep And Creep-Recovery Models For Wood Under High Stress Levels, Zhiyong Cai, Kenneth J. Fridley, Michael O. Hunt, David V. Rosowsky

Civil and Environmental Engineering and Construction Faculty Research

Forty small clear southern pine specimens were loaded under third-point bending to examine creep and creep-recovery behavior for wood under high stress levels. Stress levels of between 69% and 91% of the predicted static strength were applied for 23 h with 1 h allowed for recovery, and the resulting deflection vs. time behavior was studied. The experimental creep and creep-recovery behavior was modeled using modified power law functions. The results indicate that these functions provide the best fit to both primary and secondary experimental data. The empirical models can be used to simulate the viscoelastic behavior of wood under high …