Engineering Commons^™

Higher-Level Consistencies: Where, When, And How Much, Robert J. Woodward

School of Computing: Dissertations, Theses, and Student Research

Determining whether or not a Constraint Satisfaction Problem (CSP) has a solution is NP-complete. CSPs are solved by inference (i.e., enforcing consistency), conditioning (i.e., doing search), or, more commonly, by interleaving the two mechanisms. The most common consistency property enforced during search is Generalized Arc Consistency (GAC). In recent years, new algorithms that enforce consistency properties stronger than GAC have been proposed and shown to be necessary to solve difficult problem instances.

We frame the question of balancing the cost and the pruning effectiveness of consistency algorithms as the question of determining where, when, and how much of a higher-level …

Two Channel Sdm Communication System Simultaneously Operating At 10gb/S Using C-Band Transceivers, Han Wang

Theses and Dissertations

Increasing the bandwidth of optical fiber communications to cope with high-speed network traffic is an important goal for the communications industry. Therefore, optical communication is growing at a very rapid pace, including the multiplexing technology. Spatial domain multiplexing (SDM), also known as Space division multiplexing, is a Multi-Input Multi-Output (MIMO) architecture that can increase the data carrying capacity of optical fibers by multiple folds. SDM allows multiple channels of same wavelength to be transmitted in parallel over standard multi-mode fibers, where each SDM channel follows a different helical trajectory while traversing the length of the fiber that lead to unique …

Improving The Capacity Factor And Stability Of Multi-Mw Grid Connected Pv Systems With Results From A 1mw/2mwh Battery Demonstrator, Oluwaseun M. Akeyo, Vandana Rallabandi, Nicholas Jewell, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

Conventional PV systems integrated with a battery connect the array and the energy storage unit to a dc-link through individual dc-dc converters for maximum power point tracking (MPPT) and battery charge control. This paper proposes a new system configuration, which connects the PV array and battery unit to the dc-link of the system inverter via a single dc-dc converter capable of simultaneously operating as a charge controller and MPPT device. This dc-dc converter is controlled such that it charges/discharges the battery with the amount of power required to maintain the PV array at its MPPT reference voltage. The proposed system …

Treatment Of Acid Orange 74 Wastewater And Sugar Wastewater By Low Cost Adsorbents, S. H. Madiraju, Yung-Tse Hung, Howard H. Paul

Civil and Environmental Engineering Faculty Publications

This study shows the treatment of combined binary mixture of Acid Orange 74 and sugar wastewater with peanut hull and orange peel as low-cost adsorbents. The performance of a combined adsorption-microfiltration process for the color removal is measured and compared using transmittance and absorbance indices at mechanical shaker mix level. This selected treatment procedure is among one of the most economical treatment alternatives to all technologies present now. The parameters studied during this research are analyzed using Langmuir and Freundlich isotherm models on low cost adsorbents. Conclusive results after the treatment are indicated in this paper at their optimum dosages …

Boron-Implanted Silicon Substrates For Physical Adsorption Of Dna Origami, Sadao Takabayashi, Shohei Kotani, Juan Flores-Estrada, Elijah Spears, Jennifer E. Padilla, Lizandra C. Godwin, Elton Graugnard, Wan Kuang, William L. Hughes

Materials Science and Engineering Faculty Publications and Presentations

DNA nanostructures routinely self-assemble with sub-10 nm feature sizes. This capability has created industry interest in using DNA as a lithographic mask, yet with few exceptions, solution-based deposition of DNA nanostructures has remained primarily academic to date. En route to controlled adsorption of DNA patterns onto manufactured substrates, deposition and placement of DNA origami has been demonstrated on chemically functionalized silicon substrates. While compelling, chemical functionalization adds fabrication complexity that limits mask efficiency and hence industry adoption. As an alternative, we developed an ion implantation process that tailors the surface potential of silicon substrates to facilitate adsorption of DNA nanostructures …

Engineered Nanoparticles Interact With Nutrients To Intensify Eutrophication In A Wetland Ecosystem Experiment, Marie Simonin, Benjamin P. Colman, Steven M. Anderson, Ryan S. King, Matthew T. Ruis, Astrid Avellan, Christina M. Bergemann, Brittany G. Perrotta, Nicholas K. Geitner, Mengchi Ho, Belen De La Barrera, Jason M. Unrine, Gregory V. Lowry, Curtis J. Richardson, Mark R. Wiesner, Emily S. Bernhardt

Plant and Soil Sciences Faculty Publications

Despite the rapid rise in diversity and quantities of engineered nanomaterials produced, the impacts of these emerging contaminants on the structure and function of ecosystems have received little attention from ecologists. Moreover, little is known about how manufactured nanomaterials may interact with nutrient pollution in altering ecosystem productivity, despite the recognition that eutrophication is the primary water quality issue in freshwater ecosystems worldwide. In this study, we asked two main questions: (1) To what extent do manufactured nanoparticles affect the biomass and productivity of primary producers in wetland ecosystems? (2) How are these impacts mediated by nutrient pollution? To address …

Executive Summary_Governance For A Changing Climate: Adapting Boston’S Built Environment For Increased Flooding, Stephanie Kruel, Rebecca Herst, David Cash

Sustainable Solutions Lab

As the impacts of climate change intensify, coastal cities like Boston face increasing threats from sea level rise, extreme precipitation, and storm surges. This report, produced by the Sustainable Solutions Lab at the University of Massachusetts Boston, examines the role of governance in preparing Boston’s built environment for these evolving risks. Building upon the foundational work of the Climate Ready Boston initiative, the report outlines critical governance functions necessary for climate adaptation, including institutional coordination, regulatory reform, community engagement, and data-driven decision-making. Emphasizing a multiscalar governance approach, it analyzes the tools available at local, regional, state, and federal levels and …

Shape-Based Separation Of Micro-/Nanoparticles In Liquid Phases, Behrouz Behdani, Saman Monjezi, Mason J. Carey, Curtis G. Weldon, Jie Zhang, Cheng Wang, Joontaek Park

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The production of particles with shape-specific properties is reliant upon the separation of micro-/nanoparticles of particular shapes from particle mixtures of similar volumes. However, compared to a large number of size-based particle separation methods, shape-based separation methods have not been adequately explored. We review various up-to-date approaches to shape-based separation of rigid micro-/nanoparticles in liquid phases including size exclusion chromatography, field flow fractionation, deterministic lateral displacement, inertial focusing, electrophoresis, magnetophoresis, self-assembly precipitation, and centrifugation. We discuss separation mechanisms by classifying them as either changes in surface interactions or extensions of size-based separation. The latter includes geometric restrictions and shape-dependent transport …

Governance For A Changing Climate: Adapting Boston’S Built Environment For Increased Flooding, Stephanie Kruel, Rebecca Herst, David Cash

Sustainable Solutions Lab

As the impacts of climate change intensify, coastal cities like Boston face increasing threats from sea level rise, extreme precipitation, and storm surges. This report, produced by the Sustainable Solutions Lab at the University of Massachusetts Boston, examines the role of governance in preparing Boston’s built environment for these evolving risks. Building upon the foundational work of the Climate Ready Boston initiative, the report outlines critical governance functions necessary for climate adaptation, including institutional coordination, regulatory reform, community engagement, and data-driven decision-making. Emphasizing a multiscalar governance approach, it analyzes the tools available at local, regional, state, and federal levels and …

Concrete Pavement Blowup Considering Generalized Boundary Conditions, Jaime Hernandez, Imad L. Al-Qadi

Civil and Environmental Engineering Faculty Research and Publications

An analytical expression for static stability of a rectangular slab with two simply supported and two elastically restrained edges is presented. The linear elastic isotropic slab can represent a rigid pavement resting on an elastic foundation and loaded by a uniform in-plane axial load per unit length along the edges. The partially restrained edges are connected to the ground by translational and rotational elastic springs; an appropriate magnitude of the springs can capture classical boundary conditions such as free, simply supported, and clamped edges. Results from classical boundary conditions and a finite-element model were used to validate the proposed stability …

A Comparison Of Special Category Light-Sport And Corresponding Type-Certificated Aircraft Safety, Carolina Anderson, Alan Stolzer, Douglas D. Boyd

Publications

The special category light sport airplane (light sport) sector of general aviation has grown 10-fold in as many years with solo operations requiring only a sports pilot's certificate. With little research on light sport airplane safety, the study objective was to compare light sport and type-certificated airplane accident rates.

Accidents were identified from the National Transportation Safety Board database. Statistics employed Poisson distribution/proportion analyses/Mann–Whitney U-tests.

For the 2009–2015 period, the light sport airplane accident rate (fatal/non-fatal combined) was > 15-fold higher than comparable type-certificated aircraft, undiminished over time. The excessive light sport airplane accident rate was associated with inferior airman experience …

Application Of Dupont’S Dirty Dozen Framework To Commercial Aviation Maintenance Incidents, Greg M. Mellema

Doctoral Dissertations and Master's Theses

This study examined the 12 preconditions for maintenance errors commonly known as the Dirty Dozen and applied them to actual incident and accident data provided by a participating airline (PA). The data provided by the PA consisted of Maintenance Event Reports (MERs) (reactive), Maintenance Operations Safety Assessment (MOSA) reports (proactive), and the results of the 2017 Maintenance Climate Awareness Survey (MCAS) (subjective). The MER and MOSA reports were coded by aviation maintenance subject matter experts (SMEs) using the 12 Dirty Dozen categories as the coding scheme, while the MCAS responses were parsed according to the precondition category they best represented. …

Microfluidic Electrical Impedance Spectroscopy, John J. Foley

Master's Theses

The goal of this study is to design and manufacture a microfluidic device capable of measuring changes in impedance valuesof microfluidic cell cultures. Tocharacterize this, an interdigitated array of electrodes was patterned over glass, where it was then bonded to a series of fluidic networks created in PDMS via soft lithography. The device measured ethanol impedance initially to show that values remain consistent over time. Impedance values of water and 1% wt. saltwater were compared to show that the device is able to detect changes in impedance, with up to a 60% reduction in electrical impedance in saltwater. Cells were …

An Overview Of Direct Current Distribution System Architectures & Benefits, Venkata Anand Prabhala, Bhanu Prashant Baddipadiga, Poria Fajri, Mehdi Ferdowsi

Electrical and Computer Engineering Faculty Research & Creative Works

This paper examines existing and future direct current (DC) distribution systems with a wide range of applications in data centers, telecommunication systems, commercial buildings, residential homes, electric vehicles, spacecraft, and aircrafts. DC distribution systems have many advantages and disadvantages over their alternating current (AC) counterparts. There are a few surviving examples of DC distribution systems; among them are the telecommunication systems and data centers that use the low-voltage 48 Vdc systems. However, recently, there has been a move towards higher DC bus voltages. In this paper, a comparative study of different DC distribution architectures and bus structures is presented and …

Analysing Online User Activity To Implicitly Infer The Mental Workload Of Web-Based Tasks Using Defeasible Reasoning, Paul Mara

Dissertations

Mental workload can be considered the amount of cognitive load or effort used over time to complete a task in a complex system. Determining the limits of mental workload can assist in optimising designs and identify if user performance is affected by that design. Mental workload has also been presented as a defeasible concept, where one reason can defeat another and a 5-layer schema to represent domain knowledge to infer mental workload using defeasible reasoning has compared favourably to state-of-the-art inference techniques. Other previous work investigated using records of user activity for measuring mental workload at scale using web-based tasks …

Bs News September/October

Building Services Engineering

No abstract provided.

The Study Of Reconfigurable Antennas And Associated Circuitry, Kansheng Yang

Doctoral

This research focuses on the design of pattern reconfigurable antennas and the associated circuitry. The proposed pattern reconfigurable antenna designs benefit from advantages such as maximum pattern diversity and optimum switching circuits to realise 5G reconfigurable antennas. Whereas MIMO based solutions can provide increased channel capacity, they demand high computational capability and power consumption due to multiple channel processing. This prevents their use in many applications most notably in the Internet of Things where power consumption is of key importance. A switched-beam diversity allows an energy-efficient solution improving the link budget even for small low-cost battery operated IoT/sensor network applications. …

Accurate Flexible Refinement Of Atomic Models Against Medium-Resolution Cryo-Em Maps Using Damped Dynamics, Julio A. Kovacs, Vitold E. Galkin, Willy Wriggers

Mechanical & Aerospace Engineering Faculty Publications

Background: Dramatic progress has recently been made in cryo-electron microscopy technologies, which now make possible the reconstruction of a growing number of biomolecular structures to near-atomic resolution. However, the need persists for fitting and refinement approaches that address those cases that require modeling assistance.

Methods: In this paper, we describe algorithms to optimize the performance of such medium-resolution refinement methods. These algorithms aim to automatically optimize the parameters that define the density shape of the flexibly fitted model, as well as the time-dependent damper cutoff distance. Atomic distance constraints can be prescribed for cases where extra containment of parts of …

Assessing The Relationship Between Groundwater Nitrate Concentrations And Environmental Variables Through Repeat Sampling And Statistical Machine Learning: Dutch Flats, Nebraska, Martin Wells

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

Nitrate-contaminated aquifers are common in landscapes dominated by agricultural land use. Health concerns related to consuming nitrate-contaminated groundwater are well documented and continued research aimed at decreasing concentrations is critical. A 1990s U.S. Geological Survey (USGS) study focused on groundwater characteristics in the Dutch Flats area of western Nebraska. Agricultural-related practices were determined to largely influence groundwater recharge and nitrate concentrations ([NO₃^-]). Since the conclusion of the USGS study, a transition to more efficient irrigation technology has been observed in this region. The emphasis of this 2016 study was to resample several well nests examined in 1998 …

The Design, Test And Evaluation Of A Sensing System For Process Analytical Technology (Pat), Trevor Murphy

Theses

Increased globalisation and competitiveness has given rise to a more dynamic and diverse global market that has begun to place incredible strain on manufacturing supply chains. Conventional manufacturing methods such as the batch manufacturing methods employed largely by the materials processing industries i.e. pharmaceuticals, polymers and magnesium processing plants are ill-suited to cope with the demands of today. As products evolve with technological advancements they become more complex to produce and require alternative approaches to manufacturing to ensure product quality while reducing costs and increasing manufacturing efficiencies.

A potential solution to the growing demands on today’s supply chain is process …

Design Of Wind Turbine Tower Height And Blade Length: An Optimization Approach, Ryan Wass

Mechanical Engineering Undergraduate Honors Theses

The wind industry is a fast growing market and is quickly becoming competitive with traditional non-renewable energy resources. As with any developing industry, research must continually be redefined as more complex understandings of design variables are learned. Optimization studies are common ways to quickly refine design variable selections. Historical wind turbine data shows that the tower hub height to rotor diameter ratio scales almost linearly. However there is no specific rule that dictates the optimum hub height for a given diameter. This study addresses this question by using an Excel based optimization program to determine the height to diameter ratio …

Modeling Vocal Fold Intravascular Flow With Synthetic Replicas, Aaron David Terry

Theses and Dissertations

Communication by voice is foundational in our society and many rely on their voices for their occupations. Voice disorders affect a significant number of individuals each year, and diagnosis and treatment improvements are therefore sought via advancements in voice research. Contained in this thesis is a description of work intended to contribute to vocal fold research by using synthetic, self-oscillating vocal fold replicas to study the impact of replica vibration on perfusion fluid flow through the replica. Methods for manufacturing vocal fold replicas containing imbedded channels allowing for fluid perfusion are discussed. Experimental procedures developed for delivering perfusion fluid to …

Visual Servoing For Precision Shipboard Landing Of An Autonomous Multirotor Aircraft System, Jesse Stewart Wynn

Theses and Dissertations

Precision landing capability is a necessary development that must take place before unmanned aircraft systems (UAS) can realize their full potential in today's modern society. Current multirotor UAS are heavily reliant on GPS data to provide positioning information for landing. While generally accurate to within several meters, much higher levels of accuracy are needed to ensure safe and trouble-free operations in several UAS applications that are currently being pursued. Examples of these applications include package delivery, automatic docking and recharging, and landing on moving vehicles. The specific problem we consider is that of precision landing of a multirotor unmanned aircraft …

A Spatio-Temporal Model Reveals Self-Limiting Fcɛri Cross-Linking By Multivalent Antigens, Md Shahinuzzaman, Jawahar Khetan, Dipak Barua

Chemical and Biochemical Engineering Faculty Research & Creative Works

Aggregation of cell surface receptor proteins by multivalent antigens is an essential early step for immune cell signalling. A number of experimental and modelling studies in the past have investigated multivalent ligand-mediated aggregation of IgE receptors (FcɛRI) in the plasma membrane of mast cells. However, understanding of the mechanisms of FcɛRI aggregation remains incomplete. Experimental reports indicate that FcɛRI forms relatively small and finite-sized clusters when stimulated by a multivalent ligand. By contrast, modelling studies have shown that receptor cross-linking by a trivalent ligand may lead to the formation of large receptor superaggregates that …

Early Term Effects Of Rhbmp-2 On Pedicle Screw Fixation In A Sheep Model: Histomorphometric And Biomechanical Analyses, Jeffrey M. Toth, Mei Wang, Chetan Patel, Akshi Arora

Biomedical Engineering Faculty Research and Publications

Background: The effects of recombinant human bone morphogenetic protein-2 (rhBMP-2) on pedicle screw pullout force and its potential to improve spinal fixation have not previously been investigated. rhBMP-2 on an absorbable collagen sponge (ACS) carrier was delivered in and around cannulated and fenestrated pedicle screws in a sheep lumbar spine instability model. Two control groups (empty screw and ACS with buffer) were also evaluated. We hypothesized that rhBMP-2 could stimulate bone growth in and around the cannulated and fenestrated pedicle screws to improve early bone purchase.

Methods: Eight skeletally mature sheep underwent destabilizing laminectomies at L2–L3 and L4–L5 followed by …

Technical Note: Enhancing Soft Tissue Contrast And Radiation‐Induced Image Changes With Dual‐Energy Ct For Radiation Therapy, George Noid, An Tai, Diane Schott, Nilesh Mistry, Yu Liu, Taly Gilat Schmidt, Jared R. Robbins, X. Allen Li

Biomedical Engineering Faculty Research and Publications

Purpose

The purpose of this work is to investigate the use of low‐energy monoenergetic decompositions obtained from dual‐energy CT (DECT) to enhance image contrast and the detection of radiation‐induced changes of CT textures in pancreatic cancer.

Methods

The DECT data acquired for 10 consecutive pancreatic cancer patients during routine nongated CT‐guided radiation therapy (RT) using an in‐room CT (Definition AS Open, Siemens Healthcare, Malvern, PA) were analyzed. With a sequential DE protocol, the scanner rapidly performs two helical acquisitions, the first at a tube voltage of 80 kVp and the second at a tube voltage of 140 kVp. Virtual monoenergetic …

Cooperative Interference Control In Neighboring Passive Scattering Antennas, Shadi Ebrahimi-Asl, Mohammad Tayeb Ahmad Ghasr, Maciej Zawodniok

Electrical and Computer Engineering Faculty Research & Creative Works

Passive backscattering links in scattering sensor arrays suffer from mutual coupling among closely spaced neighbor antennas. This effect results in an unmatched circuitry at input ports of antennas causing poor power harvesting, weak backscattering, overall low read rates. In this paper, a model for mutual coupling in a $N$ by $N$ scattering antenna arrays is discussed. We show by simulations and measurements that in a two-scatterer system (one target and one neighbor antennas) the mutual coupling effect from the neighbor to the target varies depending on its load and also its location with respect to the target and the incident …

Enhancing 3d Visual Odometry With Single-Camera Stereo Omnidirectional Systems, Carlos A. Jaramillo

Dissertations, Theses, and Capstone Projects

We explore low-cost solutions for efficiently improving the 3D pose estimation problem of a single camera moving in an unfamiliar environment. The visual odometry (VO) task -- as it is called when using computer vision to estimate egomotion -- is of particular interest to mobile robots as well as humans with visual impairments. The payload capacity of small robots like micro-aerial vehicles (drones) requires the use of portable perception equipment, which is constrained by size, weight, energy consumption, and processing power. Using a single camera as the passive sensor for the VO task satisfies these requirements, and it motivates the …

Blockchain Based Efficient And Robust Fair Payment For Outsourcing Services In Cloud Computing, Yinghui Zhang, Robert H. Deng, Ximeng Liu, Dong Zheng

Research Collection School Of Computing and Information Systems

As an attractive business model of cloud computing, outsourcing services usually involve online payment and security issues. The mutual distrust between users and outsourcing service providers may severely impede the wide adoption of cloud computing. Nevertheless, most existing payment solutions only consider a specific type of outsourcing service and rely on a trusted third-party to realize fairness. In this paper, in order to realize secure and fair payment of outsourcing services in general without relying on any third-party, trusted or not, we introduce BCPay, a blockchain based fair payment framework for outsourcing services in cloud computing. We first present the …

Multi-Level Multi-Objective Programming And Optimization For Integrated Air Defense System Disruption, Aaron M. Lessin

Theses and Dissertations

The U.S. military's ability to project military force is being challenged. This research develops and demonstrates the application of three respective sensor location, relocation, and network intrusion models to provide the mathematical basis for the strategic engagement of emerging technologically advanced, highly-mobile, Integrated Air Defense Systems. First, we propose a bilevel mathematical programming model for locating a heterogeneous set of sensors to maximize the minimum exposure of an intruder's penetration path through a defended region. Next, we formulate a multi-objective, bilevel optimization model to relocate surviving sensors to maximize an intruder's minimal expected exposure to traverse a defended border region, …