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Articles 751 - 780 of 302419

Full-Text Articles in Physical Sciences and Mathematics

Approximation Algorithms For High Multiplicity Strip Packing, Thief Orienteering, And K-Median, Andrew Bloch-Hansen Aug 2024

Approximation Algorithms For High Multiplicity Strip Packing, Thief Orienteering, And K-Median, Andrew Bloch-Hansen

Electronic Thesis and Dissertation Repository

This thesis investigates three research objectives on three different problems: (1) algorithm design for problems in which the input can be grouped into a small number of classes, demonstrated on the high multiplicity strip packing problem; (2) algorithm design for problems with multiple interdependent sub-problems, demonstrated on the thief orienteering problem; and (3) algorithm design using neural networks with few layers, demonstrated on the k-median problem.

(1) The two-dimensional strip packing problem consists of packing in a rectangular strip of width $1$ and minimum height a set of $n$ rectangles, where each rectangle has width $0 < w \leq 1$ and height $0 < h \leq h_{max}$. We consider the high-multiplicity version of the problem in which there are only $K$ different types of rectangles. For the case when $K = 3$, we give an algorithm that produces solutions requiring at most height $\frac{3}{2}h_{max} + \epsilon$ plus the height of an optimal solution, where $\epsilon$ is any positive constant. For the case when $K = 4$, we give an algorithm yielding solutions of height at most $\frac{7}{3}h_{max} + \epsilon$ plus the height of an optimal solution. For the case when $K > 3$, we give an …


A Sensitivity Equation Framework For Parameter Estimation In Dynamical Systems, Joshua Newey Aug 2024

A Sensitivity Equation Framework For Parameter Estimation In Dynamical Systems, Joshua Newey

Theses and Dissertations

We present a new framework for understanding parameter estimation in dynamical systems. The approach is developed within the modeling approach of continuous data assimilation. We outline the basic assumptions that lead to our derivation. Under these assumptions we show that the parameter estimation turns into a finite dimensional nonlinear optimization problem. We show that our derivation reproduces and extends the algorithm originally developed in [9]. We then implement these methods in three example systems: the Lorenz '63 model, the two-layer Lorenz '96 model, and the Kuramoto Sivashinsky equation. So as to remain sufficiently general, our derivations are largely formal; we …


An Introduction To Category Theory, Joseph Kopp Aug 2024

An Introduction To Category Theory, Joseph Kopp

Electronic Proceedings of Undergraduate Mathematics Day

Category theory is a relatively new field of mathematics that has grown much in popularity in recent years. It is a general theory of mathematical structure that lends itself to making overarching, yet deep, connections between many branches of mathematics. This power to make such wide-reaching statements is what has drawn many to study it. However, category theory has also been criticized for being "abstract nonsense," in that some believe the theory to be too abstract to carry meaning, much less be applied to the real world. The goal of this paper is to introduce the main ideas of category …


Derivation Of The Sliding Catenary Curve Via Calculus Of Variations, Ethan Shade Aug 2024

Derivation Of The Sliding Catenary Curve Via Calculus Of Variations, Ethan Shade

Electronic Proceedings of Undergraduate Mathematics Day

Using the calculus of variations this paper derives the general equation for the "sliding catenary curve" — a hanging chain with terminal links free to slide along two poles, one tilted and one vertical. By applying physical assumptions along with the Euler-Lagrange equation, the Beltrami identity, the Legendre-Clebsch condition, the transversality condition, Lagrange multipliers, and the isoperimetric constraint, we derive the general equation for the sliding catenary curve through a functional that measures the potential energy of the hanging chain. This general equation is then compared to a real-life construction of a sliding catenary curve. Additionally the paper explores a …


Mathematical Modeling, Analysis, And Simulation Of Patient Addiction Journey, Adan Baca, Diego Gonzalez, Alonso G. Ogueda, Holly C. Matto, Padmanabhan Seshaiyer Aug 2024

Mathematical Modeling, Analysis, And Simulation Of Patient Addiction Journey, Adan Baca, Diego Gonzalez, Alonso G. Ogueda, Holly C. Matto, Padmanabhan Seshaiyer

CODEE Journal

This paper aims to develop a mathematical model to study the dynamics of addiction as individuals go through their detox journey. The motivation for this work is three fold. First, there has been a significant increase in drug overdose and drug addiction following the COVID-19 pandemic, and addiction may be interpreted as a infectious disease. Secondly, the dynamics of infectious disease could be modeled via compartmental models described by differential equations and one can therefore leverage the existing analytical and numerical methods to model addiction as a disease. Finally, the work helps to inform how mathematical models governed by differential …


Re: Butte Priority Soils Operable Unit (Bpsou) Revised Draft Final Insufficiently Reclaimed Sites Field Sampling Plans (Fsps) And Responses To Agency Comments, Mike Mcanulty Aug 2024

Re: Butte Priority Soils Operable Unit (Bpsou) Revised Draft Final Insufficiently Reclaimed Sites Field Sampling Plans (Fsps) And Responses To Agency Comments, Mike Mcanulty

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Re: Butte Priority Soils Operable Unit (Bpsou) Revised Draft Final Insufficiently Reclaimed Sites Field Sampling Plans (Fsps) And Responses To Agency Comments, Mike Mcanulty Aug 2024

Re: Butte Priority Soils Operable Unit (Bpsou) Revised Draft Final Insufficiently Reclaimed Sites Field Sampling Plans (Fsps) And Responses To Agency Comments, Mike Mcanulty

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Final Insufficiently Reclaimed Sites Quality Assurance Project Plan (Qapp), Pioneer Technical Services, Inc. Aug 2024

Final Insufficiently Reclaimed Sites Quality Assurance Project Plan (Qapp), Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Re: Butte Priority Soils Operable Unit (Bpsou) Revised Draft Final Insufficiently Reclaimed Sites Field Sampling Plans (Fsps) And Responses To Agency Comments, Mike Mcanulty Aug 2024

Re: Butte Priority Soils Operable Unit (Bpsou) Revised Draft Final Insufficiently Reclaimed Sites Field Sampling Plans (Fsps) And Responses To Agency Comments, Mike Mcanulty

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Northern Fur Ssal Vibrissae Organochlorine Contaminant Concentrations, Dimitri Giarikos, Amy Hirons, Courtney White Aug 2024

Northern Fur Ssal Vibrissae Organochlorine Contaminant Concentrations, Dimitri Giarikos, Amy Hirons, Courtney White

SECLER Data

The eastern Pacific stock of northern fur seals (Callorhinus ursinus) on the Pribilof Islands has experienced population declines since 1980. The decline may be due to anthropogenic persistent organic pollutants (POPs) which bioaccumulate, are toxic, and persistent. This study conducted a comparison of 21 organochlorine (OC) and 39 polybrominated diphenyl ether (PBDE) analyte concentrations utilizing archived vibrissae (whiskers) from individual fur seals sampled in 1993 (n=30) and 2013 (n=41). The PBDEs had values five times greater than the legacy status OCs. There were no significant mean concentration differences between 1993 and 2013 for total organochlorines (ΣOCs), or total …


Northern Fur Seal Vibrissae Polybrominateddiphenylether Concentrations, Dimitri Giarikos, Amy Hirons, Courtney White Aug 2024

Northern Fur Seal Vibrissae Polybrominateddiphenylether Concentrations, Dimitri Giarikos, Amy Hirons, Courtney White

SECLER Data

The eastern Pacific stock of northern fur seals (Callorhinus ursinus) on the Pribilof Islands has experienced population declines since 1980. The decline may be due to anthropogenic persistent organic pollutants (POPs) which bioaccumulate, are toxic, and persistent. This study conducted a comparison of 21 organochlorine (OC) and 39 polybrominated diphenyl ether (PBDE) analyte concentrations utilizing archived vibrissae (whiskers) from individual fur seals sampled in 1993 (n=30) and 2013 (n=41). The PBDEs had values five times greater than the legacy status OCs. There were no significant mean concentration differences between 1993 and 2013 for total organochlorines (ΣOCs), or total …


The Fundamental Groupoid In Discrete Homotopy Theory, Udit Ajit Mavinkurve Aug 2024

The Fundamental Groupoid In Discrete Homotopy Theory, Udit Ajit Mavinkurve

Electronic Thesis and Dissertation Repository

Discrete homotopy theory is a homotopy theory designed for studying graphs and for detecting combinatorial, rather than topological, “holes”. Central to this theory are the discrete homotopy groups, defined using maps out of grids of suitable dimensions. Of these, the discrete fundamental group in particular has found applications in various areas of mathematics, including matroid theory, subspace arrangements, and topological data analysis.

In this thesis, we introduce the discrete fundamental groupoid, a multi-object generalization of the discrete fundamental group, and use it as a starting point to develop some robust computational techniques. A new notion of covering graphs allows us …


Bernoulli Convolution Of The Depth Of Nodes In Recursive Trees With General Affinities, Toshio Nakata, Hosam Mahmoud Aug 2024

Bernoulli Convolution Of The Depth Of Nodes In Recursive Trees With General Affinities, Toshio Nakata, Hosam Mahmoud

Journal of Stochastic Analysis

No abstract provided.


The Bioremediation Effect Of Microalgae On Wastewater: A Green Technology Approach, Mohamed Ahmed Reda Hamed Dr, Marwa Abdelfattah Abdallah Dr Aug 2024

The Bioremediation Effect Of Microalgae On Wastewater: A Green Technology Approach, Mohamed Ahmed Reda Hamed Dr, Marwa Abdelfattah Abdallah Dr

Journal of Engineering Research

The present study lays an emphasis on the microalgae-based for simultaneous wastewater bioremediation using Chlorella vulgaris and Micrococcus luteus mixed algal cultures to remove its constituent pollutants, amazing green technology guarantees benefits with the decrease in the formation of dangerous solid sludge. Ten days of fully monitoring laboratory experimental program were performed in batch cultures to investigate the effect of various dominant mixing ratios for attaining wastewater concentrations and different governing temperature ranges on the performance of microalgae treatment. The results revealed that there is a significant impact of both wastewater concentrations and temperature treatment conditions on the capability of …


Unlocking The Potential Of Rooftop Sustainable Systems: Understanding Barriers And Facilitators, Mahmoud Desouki, Taghreed A. El-Haddad Aug 2024

Unlocking The Potential Of Rooftop Sustainable Systems: Understanding Barriers And Facilitators, Mahmoud Desouki, Taghreed A. El-Haddad

Journal of Engineering Research

Urbanization is reducing green spaces in old cities globally, including Egypt, adversely impacting air quality, climate, and psychological well-being. The rooftop has the potential to offer viable alternatives that provide multiple benefits. They can host sustainable systems, and foster social activities. Despite these advantages, their adoption in cities like Tanta the Egyptian city, one of the world's most densely populated cities with a shrinking per capita green space, remains limited. Most rooftops are often serving as dumping grounds for trash and unused items. This study aims to explore the reasons behind this underutilization to find ways to encourage the use …


Indicators And Evidence Of Environmental Sustainability For Pedestrian In Public Parks (Towards An Approach For Formulating A Guideline Evaluation Model), Nashwa Youssif Aug 2024

Indicators And Evidence Of Environmental Sustainability For Pedestrian In Public Parks (Towards An Approach For Formulating A Guideline Evaluation Model), Nashwa Youssif

Journal of Engineering Research

يتناول البحث أحد المجالات التي فرضت تواجدها في الأونة الأخيرة علي الساحة العلمية والبحثية التي تتعلق بالعلاقة التبادلية التأثير بين الإنسان والفراغ العمراني حيث يتنامي الإهتمام بالخصائص الإنسانيه و مدي توافقها مع هذا الفراغ العمراني.

وتعد مسارات المشاة من أهم الحيزات العمرانية التى تشكل النسيج العمراني وأحد أهم وسائل التواصل الإجتماعي والثقافي والوظيفي نظرآ لإرتباطها بالغالبية العظمي من أفراد المجتمع، ومساعدتها على جذب العديـد من الأنشطة داخل الحدائق العامة. مما يشير إلي ضرورة الإهتمام بتحسين بيئة حركة المشاه كمدخل للتواصل والإستدامة.

ومن هنا تتمثل مشكلة البحث في نقص الدراسات حول تقييم العلاقة بين معايير الاستدامة التصميمية والنظم البيئية لمسارات المشاة …


Groundwater Modeling Of The Ogallala Aquifer: Use Of Machine Learning For Model Parameterization And Sustainability Assessment, Tewodros Aboret Tilahun Aug 2024

Groundwater Modeling Of The Ogallala Aquifer: Use Of Machine Learning For Model Parameterization And Sustainability Assessment, Tewodros Aboret Tilahun

Dissertations and Doctoral Documents from University of Nebraska-Lincoln, 2023–

Addressing groundwater depletion problems in heterogeneous aquifer systems is a challenge. The heterogeneous Ogallala Aquifer, a critical source of groundwater in the central United States, has undergone decades of decline in water levels due to pumping. This project aims to build a robust groundwater model to evaluate optimal scenarios for sustainable use of the groundwater resource within a section of the Ogallala aquifer located in the Middle Republican Natural Resources District (MRNRD). This study follows a comprehensive approach involving parameterization, construction, and optimization. The model is parametrized using hydraulic conductivity and recharge values obtained from a random forest-based machine learning …


Re: Comment Letter For The Butte Priority Soils Operable Unit (Bpsou) Draft Final 2023 Bpsou Subdrain Data Summary Report (Dated May 1, 2024), Emma Rott Aug 2024

Re: Comment Letter For The Butte Priority Soils Operable Unit (Bpsou) Draft Final 2023 Bpsou Subdrain Data Summary Report (Dated May 1, 2024), Emma Rott

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Re: Comment Letter For The Butte Priority Soils Operable Unit (Bpsou) Silver Bow Creek Conservation Area (Sbcca) Technical Specifications 60 Percent Submittal (Dated April 24, 2024), Emma Rott Aug 2024

Re: Comment Letter For The Butte Priority Soils Operable Unit (Bpsou) Silver Bow Creek Conservation Area (Sbcca) Technical Specifications 60 Percent Submittal (Dated April 24, 2024), Emma Rott

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Pretty Good State Transfer And Fractional Revival In Double Extended Star Graphs, Kellon G. Sandall Aug 2024

Pretty Good State Transfer And Fractional Revival In Double Extended Star Graphs, Kellon G. Sandall

Theses and Dissertations

Much research has been done in the realm of quantum walks over networks of qubits. We primarily study a type of graph consisting of a path with two stars connected to the leaves which we call a Double Extended Star. We find that Pretty Good State Transfer can occur in many ways in a Double Extended Star and that Fractional Revival cannot occur in Double Extended Stars except when the length of the path within is one.


Waves In Cosmological Background With Static Schwarzschild Radius In The Expanding Universe, Karen Yagdjian Aug 2024

Waves In Cosmological Background With Static Schwarzschild Radius In The Expanding Universe, Karen Yagdjian

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

In this paper, we prove the existence of global in time small data solutions of semilinear Klein–Gordon equations in space-time with a static Schwarzschild radius in the expanding universe.


On Magnetic Moments Of Up And Down Quarks And Electron Neutrino Structures Composed Of Fractional Charges, Polievkt Perov Aug 2024

On Magnetic Moments Of Up And Down Quarks And Electron Neutrino Structures Composed Of Fractional Charges, Polievkt Perov

College of Arts & Sciences Faculty Works

Abstract

Using our models of elementary particles as spinning structures composed of fractional +-e/3 charges, we suggest a possible mechanism of the inverse-b reaction as the transfer of one +e/3 charge from its axial position in the antineutrino to the axial position in an up-quark of a proton. Such a transfer converts that up-quark into a positron, and the antineutrino becomes a down-quark after one of the antineutrino’s axial positive charges is removed from it. We will consider that a positron is a tetrahedral-like structure with three positive basic charges revolve about the axis passing through the fourth positive …


Chinese Tallow Long-Term Impact On Stand Dynamics In A Bottomland Hardwood Forest Following Vegetation Management, Nicklaus R. Langlois Aug 2024

Chinese Tallow Long-Term Impact On Stand Dynamics In A Bottomland Hardwood Forest Following Vegetation Management, Nicklaus R. Langlois

Electronic Theses and Dissertations

Chinese tallow (Triadica sebifera (L.) Small) is an invasive tree known to have negative impacts on bottomland hardwood forests. Chinese tallow is proficient in reproducing and surviving in bottomland hardwood forests because it is more flood and shade tolerant than most native trees. The long-term effectiveness of Chinese tallow control is an important topic to research as only a few long-term studies of Chinese tallow control have been conducted. A 10-year re-measurement of 22 paired plots installed in 2012 on the Pineywoods Mitigation Bank near Diboll, Texas following herbicide treatments examined Chinese tallow and native tree stand structure. Each …


Assimilating Satellite-Derived Snow Cover And Albedo Data To Improve 3-D Weather And Photochemical Models, Colleen Jones, Huy Tran, Trang Tran, Seth Lyman Aug 2024

Assimilating Satellite-Derived Snow Cover And Albedo Data To Improve 3-D Weather And Photochemical Models, Colleen Jones, Huy Tran, Trang Tran, Seth Lyman

Chemistry and Biochemistry Faculty Publications

During wintertime temperature inversion episodes, ozone in the Uinta Basin sometimes exceeds the standard of 70 ppb set by the US Environmental Protection Agency. Since ozone formation depends on sunlight, and less sunlight is available during winter, wintertime ozone can only form if snow cover and albedo are high. Researchers have encountered difficulties replicating high albedo values in 3-D weather and photochemical transport model simulations for winter episodes. In this study, a process to assimilate MODIS satellite data into WRF and CAMx models was developed, streamlined, and tested to demonstrate the impacts of data assimilation on the models’ performance. Improvements …


Structural Characterization Of The Puma Diapir, Gulf Of Mexico Basin, Rodrigo Velasquez Aug 2024

Structural Characterization Of The Puma Diapir, Gulf Of Mexico Basin, Rodrigo Velasquez

Electronic Theses and Dissertations

The Gulf of Mexico (GOM) Basin has been a significant target for oil and gas since the 1990s and continues today as a leading exploration target. This super basin is home to an estimated 200 BBOE (Billon barrels of oil equivalent), with current production totaling 60 BBOE for both USA and Mexico. Even though the overall depositional evolution of the GOM has allowed for the key elements for petroleum accumulations to be met, a complex structural framework is present. This framework results from the asymmetric spreading of the North American Plate from the Yucatan block crating the GOM basin we …


The Feasibility Of Utilizing The Open Dynamic Interaction Network (Odin) App To Assess Rema Data Across 30 Days Among Those Recovering From Alcoholism, Dennis E. Mcchargue, Bilal Khan, Jesscia Phelps, Patrick Duryea, Kimberly A. Tyler, Arthur Andrews, Ellie Reznicek, Lucy Napper, Mohamed Saad, Hsuan-Wee Lee Aug 2024

The Feasibility Of Utilizing The Open Dynamic Interaction Network (Odin) App To Assess Rema Data Across 30 Days Among Those Recovering From Alcoholism, Dennis E. Mcchargue, Bilal Khan, Jesscia Phelps, Patrick Duryea, Kimberly A. Tyler, Arthur Andrews, Ellie Reznicek, Lucy Napper, Mohamed Saad, Hsuan-Wee Lee

Department of Psychology: Faculty Publications

About ~4 million people with an alcohol use disorder receive treatment annually, and frequent relapse has produced a rapid revolving door between recovery and use. This paper presents preliminary data from a prospective micro-longitudinal study (30 days) that examines co-evolution of relapse risk processes of people with alcohol use disorders who entered a short-term residential substance use treatment. The primary goal of the current data was to assess the feasibility of using the open dynamic interaction network (ODIN) responsive ecological momentary assessment (rEMA). rEMA collected daily estimates on affect, urges, sober-support engagement, and use. The ODIN app administered twelve questions …


Making And Breaking Bonds: Studying Intrinsic Chemistry In The Gas-Phase, Luke Metzler Aug 2024

Making And Breaking Bonds: Studying Intrinsic Chemistry In The Gas-Phase, Luke Metzler

Electronic Theses and Dissertations

The nature of chemical interactions can be difficult to ascertain in the condensed phase; chemistry can be observed, but with the plethora of variables such as solvation, mixes of counter-ions, and complex equilibria, the true intrinsic chemical properties of a given chemical species may be obfuscated. By conducting research in the gas-phase, many of these variables can be reduced, if not eliminated entirely, which can allow for the careful observation of the true physical phenomena driving chemical reactivity.

The research presented herein focuses on the use of ion-trapping (specifically in a linear ion trap) as a method for unveiling the …


Open-Source Forensics Tools Are Great Tools For Critical Used Machines, Erik Herrera Aug 2024

Open-Source Forensics Tools Are Great Tools For Critical Used Machines, Erik Herrera

Electronic Theses and Dissertations

Open-Source software exists on everything from operating systems to daily productivity applications. In digital forensics, a very popular tool that is used to learn on and expand is Autopsy. Autopsy is known in the digital world due to its potential and wide usage. It is in many built packages of software inside the open-source world of applications. It is built into premade operating systems that are involved in Digital Forensics and Penetration Testing. Prebuilt OS includes Kali Linux and Computer Aided Investigative Environment (CAINE).

In the application to defend Open-Source software being just as good as closed-source software, I will …


Aquatics As A Therapeutic Intervention And Its Effects On The Quality Of Life Of People Diagnosed With Amyotrophic Lateral Sclerosis, Brianna Barcelo, Lakesia Boykin, Helen Carey Aug 2024

Aquatics As A Therapeutic Intervention And Its Effects On The Quality Of Life Of People Diagnosed With Amyotrophic Lateral Sclerosis, Brianna Barcelo, Lakesia Boykin, Helen Carey

Summer 2024 OTD Capstone Symposium

: Interventions in the form of aquatics have been utilized with the profession of occupational therapy as the aquatic environment is a model setting for addressing occupational therapy interests (Becker, 2009). Although aquatic interventions are utilized within profession, there is limited research discussing how aquatics as a therapeutic intervention effects the quality of life (QoL) of people diagnosed with ALS. Therefore, the purpose of the research project was to explore the effects of aquatics as a therapeutic intervention on the QoL of those diagnosed with ALS.


Examining The Lived Experiences Of Educators Using Different Levels Of Support For Teaching Math To Students With Learning Disabilities In Math Computation And Problem-Solving For Teachers At Public Cyber Charter High Schools In The Northeastern United States: A Transcendental Phenomenological Study, Leeann E. Mccullough Aug 2024

Examining The Lived Experiences Of Educators Using Different Levels Of Support For Teaching Math To Students With Learning Disabilities In Math Computation And Problem-Solving For Teachers At Public Cyber Charter High Schools In The Northeastern United States: A Transcendental Phenomenological Study, Leeann E. Mccullough

Doctoral Dissertations and Projects

The purpose of this transcendental phenomenological study was to describe the lived experiences of educators using different levels of support for teaching math to students with learning disabilities in math computation and problem-solving for teachers at public cyber charter high schools in the Northeastern United States. The theory guiding this study was Sweller’s cognitive load theory, as it explained the learning process of students with learning disabilities and how educators developed instructional methods that complement the learner’s needs. The central research question was, “What is the lived experience of 9-12th-grade mathematics teachers in supporting students with differing learning abilities in …