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2019

Wilfrid Laurier University

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Articles 1 - 23 of 23

Full-Text Articles in Physical Sciences and Mathematics

Solution Of Simultaneous Chemical Equilibria In Heterogeneous Systems: Implementation In Matlab, D. Scott Smith Sep 2019

Solution Of Simultaneous Chemical Equilibria In Heterogeneous Systems: Implementation In Matlab, D. Scott Smith

Chemistry Faculty Publications

A Matlab script to solve simultaneous equilibria in solution, including precipitation/dissolution equilibria is described.


Shale Play: Poems And Photographs From The Fracking Fields By Julia Spicher Kasdorf And Steven Rubin, Kelly Shepherd Jun 2019

Shale Play: Poems And Photographs From The Fracking Fields By Julia Spicher Kasdorf And Steven Rubin, Kelly Shepherd

The Goose

Review of Julia Spicher Kasdorf and Steven Rubin's Shale Play: Poems and Photographs from the Fracking Fields


Rationality In Bargaining By Finite Automata, Jim Bell Jan 2019

Rationality In Bargaining By Finite Automata, Jim Bell

Theses and Dissertations (Comprehensive)

Aspects of behavioral decision-making can be integrated into game-theoretic models of two-player bargaining using finite automata which can represent bargaining strategies in combination with various behavioral traits. The automata are used as bargaining agents who must jointly agree upon a fixed allocation of transferable utility in an infinite-horizon Rubinstein bargaining game. At each turn, the automata are given the opportunity to accept a proposed portion of the transferable utility, or to reject the proposal and make a counter-offer of their own. A round-robin tournament and ecological simulations were run to explore strategic dominance under different conditions. Principles of bargaining strategy …


High Resolution Spatial Variability In Spring Snowmelt For An Arctic Shrub-Tundra Watershed, Branden J. Walker, Philip Marsh Dr Jan 2019

High Resolution Spatial Variability In Spring Snowmelt For An Arctic Shrub-Tundra Watershed, Branden J. Walker, Philip Marsh Dr

Theses and Dissertations (Comprehensive)

Arctic tundra environments are characterized by spatially heterogeneous end-of-winter snow cover because of high winds that erode, transport and deposit snow over the winter. This spatially variable end-of-winter snow cover subsequently influences the spatial and temporal variability of snowmelt and results in a patchy snowcover over the melt period. Documenting changes in both snow cover area (SCA) and snow water equivalent (SWE) during the spring melt is essential for understanding hydrological systems, but the lack of high-resolution SCA and SWE datasets that accurately capture micro-scale changes are not commonly available, and do not exist for the Canadian Arctic. This study …


Toward Using High-Frequency Coastal Radars For Calibration Of S-Ais Based Ocean Vessel Tracking Models, Ben Freidrich Jan 2019

Toward Using High-Frequency Coastal Radars For Calibration Of S-Ais Based Ocean Vessel Tracking Models, Ben Freidrich

Theses and Dissertations (Comprehensive)

Most of the world relies on ships for transportation, shipping, and tourism. Automatic Identification System messages are transmitted from ships and provide a wealth of positional data on these open ocean vessels. This data is being utilized to determine the optimal path for ships, as well as predicting where a ship may be going in the near future. It has only been in the past decade that Automatic Identification Systems (AIS) signals have been easily received with satellites (S-AIS) so there have been few studies that look at using available information and pairing it with the new abundance of ship …


Separability And Vertex Ordering Of Graphs, Elizabeth Gorbonos Jan 2019

Separability And Vertex Ordering Of Graphs, Elizabeth Gorbonos

Theses and Dissertations (Comprehensive)

Many graph optimization problems, such as finding an optimal coloring, or a largest clique, can be solved by a divide-and-conquer approach. One such well-known technique is decomposition by clique separators where a graph is decomposed into special induced subgraphs along their clique separators. While the most common practice of this method employs minimal clique separators, in this work we study other variations as well. We strive to characterize their structure and in particular the bound on the number of atoms. In fact, we strengthen the known bounds for the general clique cutset decomposition and the minimal clique separator decomposition. Graph …


Multiscale Mathematical Modelling Of Nonlinear Nanowire Resonators For Biological Applications, Rosa Fallahpourghadikolaei Jan 2019

Multiscale Mathematical Modelling Of Nonlinear Nanowire Resonators For Biological Applications, Rosa Fallahpourghadikolaei

Theses and Dissertations (Comprehensive)

Nanoscale systems fabricated with low-dimensional nanostructures such as carbon nanotubes, nanowires, quantum dots, and more recently graphene sheets, have fascinated researchers from different fields due to their extraordinary and unique physical properties. For example, the remarkable mechanical properties of nanoresonators empower them to have a very high resonant frequency up to the order of giga to terahertz. The ultra-high frequency of these systems attracted the attention of researchers in the area of bio-sensing with the idea to implement them for detection of tiny bio-objects. In this thesis, we originally propose and analyze a mathematical model for nonlinear vibrations of nanowire …


Explainable Neural Attention Recommender Systems, Omer Tal Jan 2019

Explainable Neural Attention Recommender Systems, Omer Tal

Theses and Dissertations (Comprehensive)

Recommender systems, predictive models that provide lists of personalized suggestions, have become increasingly popular in many web-based businesses. By presenting potential items that may interest a user, these systems are able to better monetize and improve users’ satisfaction. In recent years, the most successful approaches rely on capturing what best define users and items in the form of latent vectors, a numeric representation that assumes all instances can be described by their respective affiliation towards a set of hidden features. However, recommendation methods based on latent features still face some realworld limitations. The data sparsity problem originates from the unprecedented …


Development And Application Of Hydrological And Limnological Monitoring In Lake-Rich Landscapes Of Canada’S Subarctic National Parks, Hilary Emma White Jan 2019

Development And Application Of Hydrological And Limnological Monitoring In Lake-Rich Landscapes Of Canada’S Subarctic National Parks, Hilary Emma White

Theses and Dissertations (Comprehensive)

Arctic and subarctic environments are being adversely influenced by human-caused climate change across our entire planet. Canada’s northern freshwater ecosystems are influenced by a variety of environmental stressors and are particularly sensitive to climate change, since small shifts in climate have the potential to substantially alter their hydrological, limnological, and biogeochemical conditions. Some other indirect effects on northern freshwater landscapes are the expansion of vegetation as well as changes in wildlife and waterfowl populations and distribution. It is, therefore, critical to understand the observed and predicted influences of climate change and other environmental stressors on these northern freshwater environments dominant …


Nanoscale Building Blocks: Bridging The Gap Between Potential And Realized Applications, Nicole Ritter Jan 2019

Nanoscale Building Blocks: Bridging The Gap Between Potential And Realized Applications, Nicole Ritter

Theses and Dissertations (Comprehensive)

The vast potential of nanoparticles and nanotechnology remains largely untapped; the crucial bottleneck being the knowledge gap between making and using nanoparticles (NPs). This PhD work bridges this gap by focusing on synthesizing nanoparticles with applications at the forefront. Four peer-reviewed publications are presented in Chapters 3-6, a safety and toxicological perspective is given in Chapter 7, and current work and future progress are summarized in Appendix 1. Bimorphic silver nanoparticles were prepared, presenting an innovative method to synthesize diverse nanostructures using polymeric surface blocking to break symmetry in seeded regrowth (Chapter 3).1 Silver stars with D5h symmetry …


Influence Of Ligand Complexation On Nickel Toxicity, Speciation And Bioavailability In Marine Waters, Samantha Sherman Jan 2019

Influence Of Ligand Complexation On Nickel Toxicity, Speciation And Bioavailability In Marine Waters, Samantha Sherman

Theses and Dissertations (Comprehensive)

Currently there are no site-specific bioavailability-based prediction models for assessing the impacts of nickel (Ni) in marine environments although there are indications that these may be warranted. The aim of this research was to characterize the complexation of Ni in relation to toxicity and speciation. Various complexing ligands were used, and it was predicted that the binding affinity (logKf) of ligands would be inversely correlated to toxicity based on dissolved Ni concentrations ([NiD]) but that on a free ion concentration ([Ni2+]) basis, toxicity would not vary. A two-phased approach was used; the first was a proof of principle where synthetic …


Generative Adversarial Networks For Online Visual Object Tracking Systems, Ghsoun Zin Jan 2019

Generative Adversarial Networks For Online Visual Object Tracking Systems, Ghsoun Zin

Theses and Dissertations (Comprehensive)

Object Tracking is one of the essential tasks in computer vision domain as it has numerous applications in various fields, such as human-computer interaction, video surveillance, augmented reality, and robotics. Object Tracking refers to the process of detecting and locating the target object in a series of frames in a video. The state-of-the-art for tracking-by-detection framework is typically made up of two steps to track the target object. The first step is drawing multiple samples near the target region of the previous frame. The second step is classifying each sample as either the target object or the background. Visual object …


Analysis Of Clmr Trees For European And Asian Option Pricing Under Regime-Switching Jump-Diffusion Models, Yaode Sui Jan 2019

Analysis Of Clmr Trees For European And Asian Option Pricing Under Regime-Switching Jump-Diffusion Models, Yaode Sui

Theses and Dissertations (Comprehensive)

In this paper, we study the convergence rates of the multinomial trees constructed by [Costabile, Leccadito, Massabo and Russo, Journal of Computational and Applied Mathematics, 256 (2014), 152 - 167] for European option pricing under the regime-switching jump-diffusion model, which is named as CLMR tree. We also extend the CLMR tree to the pricing of Asian options under the models. Numerical examples are carried out to confirm the theoretical results and the accuracy of computation.


Using Paleolimnology To Establish Baseline Conditions For Metal Contaminants In Advance Of Proposed Mining To Inform A Northern Community-Led Aquatic Monitoring Program, Tłı̨Chǫ Lands, Northwest Territories, Canada., James Telford Jan 2019

Using Paleolimnology To Establish Baseline Conditions For Metal Contaminants In Advance Of Proposed Mining To Inform A Northern Community-Led Aquatic Monitoring Program, Tłı̨Chǫ Lands, Northwest Territories, Canada., James Telford

Theses and Dissertations (Comprehensive)

The Marian Watershed Stewardship Program (MWSP), a community-driven aquatic ecosystem monitoring program, was developed by the Tłı̨chǫ Government to address concerns regarding the cumulative impacts of multiple potential stressors. In particular, the MWSP aims to develop methods that will be effective for detecting potential pollution from the proposed cobalt-gold-copper-bismuth NICO mine within Tłı̨chǫ Lands. In collaboration with the MWSP, paleolimnological methods and geochemical normalization are used to establish pre-mine baselines of lake sediment metals concentrations in the Marian River watershed prior to mine development. This baseline framework can be used to assess for pollution from surficial sediment once the mine …


Estimation Of Multivariate Asset Models With Jumps, Angela Loregian, Laura Ballotta, Gianluca Gianluca Fusai, Marcos Fabricio Perez Jan 2019

Estimation Of Multivariate Asset Models With Jumps, Angela Loregian, Laura Ballotta, Gianluca Gianluca Fusai, Marcos Fabricio Perez

Business Faculty Publications

We propose a consistent and computationally efficient two-step methodology for the estimation of multidimensional non-Gaussian asset models built using Levy processes. The proposed framework allows for dependence between assets and different tail behaviors and jump structures for each asset. Our procedure can be applied to portfolios with a large number of assets as it is immune to estimation dimensionality problems. Simulations show good finite sample properties and significant efficiency gains. This method is especially relevant for risk management purposes such as, for example, the computation of portfolio Value at Risk and intra-horizon Value at Risk, as we show in detail …


Biogeochemical And Hydrological Impacts Of A Low-Severity Wildfire In The Wetland-Dominated Zone Of Discontinuous Permafrost, Caren J. Ackley Jan 2019

Biogeochemical And Hydrological Impacts Of A Low-Severity Wildfire In The Wetland-Dominated Zone Of Discontinuous Permafrost, Caren J. Ackley

Theses and Dissertations (Comprehensive)

Northern regions are experiencing rapid climate warming. As these regions warm, the occurrences of naturally ignited wildfires are increasing in frequency, severity and area burned, calling for a more thorough understanding of post-fire eco-hydrological impacts. Changes in runoff chemistry, and soil moisture and thermal regimes, have been attributed to the significant loss of organic matter (OM) and exposure of deeper soils, leading to enhanced permafrost degradation, ground surface subsidence and the conversion of peat landscapes from long-term C sinks to sources. However, low-severity wildfires often result in minor OM loss. Due to the significant and immediate threats posed to the …


Towards Secure And Fair Iiot-Enabled Supply Chain Management Via Blockchain-Based Smart Contracts, Amal Eid Alahmadi Jan 2019

Towards Secure And Fair Iiot-Enabled Supply Chain Management Via Blockchain-Based Smart Contracts, Amal Eid Alahmadi

Theses and Dissertations (Comprehensive)

Integrating the Industrial Internet of Things (IIoT) into supply chain management enables flexible and efficient on-demand exchange of goods between merchants and suppliers. However, realizing a fair and transparent supply chain system remains a very challenging issue due to the lack of mutual trust among the suppliers and merchants. Furthermore, the current system often lacks the ability to transmit trade information to all participants in a timely manner, which is the most important element in supply chain management for the effective supply of goods between suppliers and the merchants. This thesis presents a blockchain-based supply chain management system in the …


Characterization Of The Microbial Phosphonate-Activating Pntc Enzymes, Kyle Rice Jan 2019

Characterization Of The Microbial Phosphonate-Activating Pntc Enzymes, Kyle Rice

Theses and Dissertations (Comprehensive)

New strategies are urgently needed to combat infectious diseases in an era of rising antibiotic resistance. Furthermore, an emerging appreciation for the human microbiome’s role in maintaining health motivates discovery of species-specific antibiotics that minimally disrupt our native bacterial communities. Small molecule modifications to bacterial cell surfaces represent a potentially rich source of new targets for next generation antibiotics, as these molecules mediate virulence and evasion of the host immune response. Phosphocholine (PCho) is a rare cell surface modification that contributes to virulence, and modifications with phosphonates like 2-aminoethylphosphonate (AEP) are even more unusual and therefore provide opportunities for species- …


Potential Impact Of Northern Resource Development On Aquatic Biota: Toxicity Of Chromium And Rare Earth Element Processing Reagent, So Yeon Choi Jan 2019

Potential Impact Of Northern Resource Development On Aquatic Biota: Toxicity Of Chromium And Rare Earth Element Processing Reagent, So Yeon Choi

Theses and Dissertations (Comprehensive)

Chromite and rare earth element development was identified in the 2015 Canadian Federal budget as a significant opportunity, however, key data gaps exist regarding the environmental concerns related to these resource developments. Chromium is essential in the production of stainless steel, and no suitable substitute is known. Rare earth elements (REEs) are a series of metals that are composed of 15 lanthanides, as well as scandium and yttrium. Uses for REEs range from electronic devices (i.e. cell phones, computers, televisions) to magnets and controlling nuclear reactors. While commercial production of REEs signify a great economic opportunity for Canada, key data …


Vertex Coloring With Forbidden Subgraphs, Yingjun Dai Jan 2019

Vertex Coloring With Forbidden Subgraphs, Yingjun Dai

Theses and Dissertations (Comprehensive)

Given a set $L$ of graphs, a graph $G$ is $L$-free if $G$ does not contain any graph in $L$ as induced subgraph. A $hole$ is an induced cycle of length at least $4$. A $hole$-$twin$ is a graph obtained by adding a vertex adjacent to three consecutive vertices in a $hole$. Hole-twins are closely related to the characterization of the line graphs in terms of forbidden subgraphs.

By using {\it clique-width} and {\it perfect graphs} theory, we show that ($claw$,$4K_1$,$hole$-$twin$)-free graphs and ($4K_1$,$hole$-$twin$,$5$-$wheel$)-free graphs are either perfect or have bounded clique-width. And thus the coloring of them can be …


Use Of Pre-Industrial Baselines To Assess Sources And Pathways Of Metals In Surface Sediment Of Floodplain Lakes In The Peace-Athabasca Delta (Alberta, Canada), Tanner Owca Jan 2019

Use Of Pre-Industrial Baselines To Assess Sources And Pathways Of Metals In Surface Sediment Of Floodplain Lakes In The Peace-Athabasca Delta (Alberta, Canada), Tanner Owca

Theses and Dissertations (Comprehensive)

The effects of natural resources exploitation in northern Canada on downstream aquatic ecosystems is a concern. Assessing these effects requires comprehensive monitoring practices to better inform stakeholders and environmental stewardship decisions. Here, a monitoring approach is developed and applied to assess metals concentrations in lake surface sediments of the Peace-Athabasca Delta (PAD), northern Alberta, Canada. Since the ecological integrity of the PAD is strongly tied to river floodwaters that are critical for replenishing the delta, and the PAD is located downstream of the Alberta oil sands, concerns have been raised over the potential transport of metal contaminants to the PAD …


Temperature-Dependent Kinetic Studies Of Arsenicals Adsorption From Solution To Hematite Nanoparticles, Sara Soldoozy Jan 2019

Temperature-Dependent Kinetic Studies Of Arsenicals Adsorption From Solution To Hematite Nanoparticles, Sara Soldoozy

Theses and Dissertations (Comprehensive)

Surface chemistry is the study of the chemical and physical phenomena that transpire at interfaces such as liquid-solid, solid-gas, liquid-gas, and liquid-liquid. To study the reactions occurred at the surfaces, surface sensitive techniques come to play. Adsorption of arsenical compounds (liquid adsorbate), particularly arsenate (iAs) and dimethylarsinic acid (DMA), to the surface of iron bearing materials (solid adsorbent) that frequently are found in geosorbents such as hematite (Fe2O3) has been studied in this thesis. Arsenical compounds can pollute the environment through natural sources and anthropogenic activities, and ultimately contaminate water. Absorbing these pollutants to a material …


Cosmic Ray Sensors For The Continuous Measurement Of Arctic Snow Accumulation And Melt, Anton Jitnikovitch Jan 2019

Cosmic Ray Sensors For The Continuous Measurement Of Arctic Snow Accumulation And Melt, Anton Jitnikovitch

Theses and Dissertations (Comprehensive)

In the Arctic, winter persists for much of the year, resulting in a hydrological system that is primarily regulated by snow and snowmelt runoff, and has important implications on vegetation, animals, and on the thermal regime of the active layer and permafrost. Snow water equivalent (SWE) measurements such as remote sensing techniques provide coarse resolution data, while snow surveys and snow-pits are labour intensive, have limited spatial coverage and do not provide a continuous reading. Over the last few decades, cosmic ray sensors (CRS) have been proposed as a way to provide much improved snow data, but few studies have …