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Articles 1291 - 1320 of 3859

Full-Text Articles in Physical Sciences and Mathematics

The Importance Of Traditional Ecological Knowledge In Agroecological Systems In Peru, Christina R. Saylor, Kamal Alsharif, Hannah Torres Jan 2017

The Importance Of Traditional Ecological Knowledge In Agroecological Systems In Peru, Christina R. Saylor, Kamal Alsharif, Hannah Torres

School of Geosciences Faculty and Staff Publications

This study argues that a critical element in the success of an ecosystem service (ES) approach at any level is the higher qualitative valuation of local traditional ecological knowledge (TEK). As such, the objectives of this research were to illustrate the role of TEK in agroecological systems in Peru and to develop recommendations about this type of knowledge acquisition. The data were gathered using interviews and focus groups with subsistence farmers along with key informant interviews to elicit TEK at local and regional scales in five provinces in the Lake Titicaca region of Puno, Peru. Qualitative analysis revealed dominant themes …


High Speed Imaging, Lightning Mapping Arrays And Thermal Imaging: A Synergy For The Monitoring Of Electrical Discharges At The Onset Of Volcanic Explosions, Damien Gaudin, Corrado Cimarelli, Sonja A. Behnke, Valeria Cigala, Harald E. Edens, Stephen R. Mcnutt, Cassandra M. Smith, Ronald J. Thomas, Alexa R. Van Eaton Jan 2017

High Speed Imaging, Lightning Mapping Arrays And Thermal Imaging: A Synergy For The Monitoring Of Electrical Discharges At The Onset Of Volcanic Explosions, Damien Gaudin, Corrado Cimarelli, Sonja A. Behnke, Valeria Cigala, Harald E. Edens, Stephen R. Mcnutt, Cassandra M. Smith, Ronald J. Thomas, Alexa R. Van Eaton

School of Geosciences Faculty and Staff Publications

Volcanic lightning is being increasingly studied, due to its great potential for the detection and monitoring of ash plumes. Indeed, it is observed in a large number of ash-rich volcanic eruptions and it produces electromagnetic waves that can be detected remotely in all weather conditions. Electrical discharges in volcanic plume can also significantly change the structural, chemical and reactivity properties of the erupted material. Although electrical discharges are detected in various regions of the plume, those happening at the onset of an explosion are of particular relevance for the early warning and the study of volcanic jet dynamics. In order …


Danger Of Snow In The Sunshine State, Dmitrii Karpenko Jan 2017

Danger Of Snow In The Sunshine State, Dmitrii Karpenko

Undergraduate Journal of Mathematical Modeling: One + Two

The main purpose of the project is to investigate the maximum deflection of a rectangular 16 x 8 inches beam, supported on both ends under uniform loading stress under snow pressure in the event that Tampa experiences snowfall. The required information for the project is the material of the beam and its dimensions, measurement of the area of the roof that would accumulate snow, and calculations of the Moment of Inertia and Uniform Distributed Load for the beam. The maximum deflection of the beam can be calculated using the information above.

The outcome of the research shows that the roof …


Efficacy Of Acute Normovolemic Hemodilution In The Setting Of Chronic Anemia, Andrew Vieira Jan 2017

Efficacy Of Acute Normovolemic Hemodilution In The Setting Of Chronic Anemia, Andrew Vieira

Undergraduate Journal of Mathematical Modeling: One + Two

A theoretical model for calculating hematocrit as it relates to blood volume loss was used to test the theoretical impact of acute normovolemic hemodilution prior to surgery in a chronically anemic patient. The technique of hemodilution is intended to decrease red blood cell loss that occurs as the result of surgical intervention, however its impact may be decreased in an anemic patient. An equation to find change in hematocrit resulting from blood volume loss was elucidated via integration. This equation was then applied to a theoretical patient with 5 L of blood and a hematocrit of 32 percent which revealed …


Analysis Of Rainfall In Tampa, Amy Polen Jan 2017

Analysis Of Rainfall In Tampa, Amy Polen

Undergraduate Journal of Mathematical Modeling: One + Two

Rainfall for a region is very important to define, because it affects an ecosystem health, wildlife, and even human behavior. Using data obtained from National Oceanographic and Atmospheric Administration (NOAA) at the Tampa Bay International Airport and graphing it, the total rainfall for a year was estimated by both a rough trapezoidal Riemann’s sum approximation and a definite integral generated by polynomial regression. It was determined that both approximations gave an underestimate of the total rainfall that was measured, but the polynomial integral gave a reasonable estimate with a small percent error. It was seen through the graphical representation of …


Evidence Of Long-Term Nao Influence On East-Central Europe Winter Precipitation From A Guano-Derived Δ15N Record, Daniel M. Cleary, Jonathan G. Wynn, Monica Ionita, Ferenc L. Forray, Bogdan P. Onac Jan 2017

Evidence Of Long-Term Nao Influence On East-Central Europe Winter Precipitation From A Guano-Derived Δ15N Record, Daniel M. Cleary, Jonathan G. Wynn, Monica Ionita, Ferenc L. Forray, Bogdan P. Onac

School of Geosciences Faculty and Staff Publications

Currently there is a scarcity of paleo-records related to the North Atlantic Oscillation (NAO), particularly in East-Central Europe (ECE). Here we report δ15N analysis of guano from a cave in NW Romania with the intent of reconstructing past variation in ECE hydroclimate and examine NAO impacts on winter precipitation. We argue that the δ15N values of guano indicate that the nitrogen cycle is hydrologically controlled and the δ15N values likely reflect winter precipitation related to nitrogen mineralization prior to the growing season. Drier conditions indicated by δ15N values at AD 1848–1852 and …


Writing In Geology To Reduce Math Anxiety, Victor Ricchezza, H. L. Vacher Jan 2017

Writing In Geology To Reduce Math Anxiety, Victor Ricchezza, H. L. Vacher

School of Geosciences Faculty and Staff Publications

Students in GLY 4866: Computational Geology at the University of South Florida learn to solve mathematical problems in a geologic context. Quantitative literacy – a fundamental set of skills and habits of mind – is essential to geologists in any of a variety of occupations, and this course helps prepare students for those careers.

Based on suggestions from prior interviews with alumni, we introduced a detailed reading and writing assignment into the course for fall 2016. Students submitted a general written statement about how the felt about math, and then read The Math Instinct: Why you're a Mathematical Genius (along …


The Acceleration Of Dissolved Cobalt's Ecological Stoichiometry Due To Biological Uptake, Remineralization, And Scavenging In The Atlantic Ocean, Mak A. Saito, Abagail E. Noble, Nicholas Hawco, Benjamin S. Twining, Daniel C. Ohnemus, Seth G. John, Phoebe Lam, Tim M. Conway, Rod Johnson, Dawn Moran, Matthew Mcilvin Jan 2017

The Acceleration Of Dissolved Cobalt's Ecological Stoichiometry Due To Biological Uptake, Remineralization, And Scavenging In The Atlantic Ocean, Mak A. Saito, Abagail E. Noble, Nicholas Hawco, Benjamin S. Twining, Daniel C. Ohnemus, Seth G. John, Phoebe Lam, Tim M. Conway, Rod Johnson, Dawn Moran, Matthew Mcilvin

School of Geosciences Faculty and Staff Publications

The stoichiometry of biological components and their influence on dissolved distributions have long been of interest in the study of the oceans. Cobalt has the smallest oceanic inventory of inorganic micronutrients and hence is particularly vulnerable to influence by internal oceanic processes including euphotic zone uptake, remineralization, and scavenging. Here we observe not only large variations in dCo:P stoichiometry but also the acceleration of those dCo:P ratios in the upper water column in response to several environmental processes. The ecological stoichiometry of total dissolved cobalt (dCo) was examined using data from a US North Atlantic GEOTRACES transect and from a …


Alternative Typing Learning Curves, Marcel Kreuzer Jan 2017

Alternative Typing Learning Curves, Marcel Kreuzer

Undergraduate Journal of Mathematical Modeling: One + Two

Typing is a part of everyday life for many people. However some people have difficulty in doing it. For example, for people who are blind and those who have carpal tunnel or cerebral palsy, a standard keyboard would not be effective to type. Alternative options include voice recognition and keyless keyboards. We focus on orbiTouch keyboard which has no keys, only two knobs which allow a person to type. Which alternative way of typing would be most effective given a person’s condition is discussed.


Application Of Simple Harmonics Modeling A Shock, Kai Raymond Jan 2017

Application Of Simple Harmonics Modeling A Shock, Kai Raymond

Undergraduate Journal of Mathematical Modeling: One + Two

This project entails modeling a spring-shock absorber system in order to evaluate the position of a mass when this system is acted upon by outside forces. We will restrict our attention to the linear case where it is assumed that Hooke’s law gives the force exerted by the spring, and the resistance of the system will be proportional to the velocity of the mass. We analyze the time and frequency domain of the absorber system and compute its impulse response.


Optimization Of A Fuel Cell, Eduardo Gines Jan 2017

Optimization Of A Fuel Cell, Eduardo Gines

Undergraduate Journal of Mathematical Modeling: One + Two

Fuel cells are devices that generate energy from a chemical reaction that takes place inside the cell. The main parts of these devices are two electrodes and an electrolyte solution. The project consists of determining the area of the electrodes for the fuel cell at which the cell produces its maximum amount of power. This was done with the performance curve of the fuel cell which was in terms of voltage vs current density. The performance curve was turned into terms of power density vs current density, and through this curve the maximum power was determined by identifying the maximum …


Approximating Surface Area Of Fluctuating Lipid Leaflets Using Weighted Grid Tessellation, Ahnaf Siddiqui Jan 2017

Approximating Surface Area Of Fluctuating Lipid Leaflets Using Weighted Grid Tessellation, Ahnaf Siddiqui

Undergraduate Journal of Mathematical Modeling: One + Two

The surface area per lipid is an important quantity useful in characterizing lipid bilayer structure and dynamics. However, simply dividing the flat surface area covered by the number of lipids does not give a sufficient characterization of surface dynamics in cases where parts of the lipid leaflets have curvaceous trajectories in three dimensions. An algorithm is proposed for modeling surface area per lipid using a three-dimensional tessellated grid. In this way both the vertical, as well as the more commonly considered the horizontal, fluctuations of lipids are used to accurately determine the area covered. This algorithm can reveal differences in …


The Solow Model And Standard Of Living, Eric Frey Jan 2017

The Solow Model And Standard Of Living, Eric Frey

Undergraduate Journal of Mathematical Modeling: One + Two

All across the world, living standards vary significantly. The Solow growth model, developed by Nobel Prize winning economist Robert Solow in 1956, is still one of the most commonly used models in economics to explain economic growth. This paper will outline the Solow growth model, and its assertion that increases in total factor productivity (TFP) can lead to limitless increases in the standard of living in a country. Much of the mathematical notation and explanation has been derived from Stephen Williamson of Washington University. Additionally, it will provide empirical examples illustrating the model’s ability to match real-world data.


The Forces Affecting A Sailboat, Kelly Stukbauer Jan 2017

The Forces Affecting A Sailboat, Kelly Stukbauer

Undergraduate Journal of Mathematical Modeling: One + Two

The objective of this project is to determine the specific effects of the various forces acting on a sailboat. Through this project, a greater understanding of both the physics behind sailing, and the calculus behind that physics, shall be gained.


Rudimentary Model Of Glucose Response To Stress, Nasha Rios-Guzman Jan 2017

Rudimentary Model Of Glucose Response To Stress, Nasha Rios-Guzman

Undergraduate Journal of Mathematical Modeling: One + Two

A simplistic multifactorial model was crafted to represent change in plasma glucose concentrations after increases in stress hormones above baseline. A sample application of the predictive use of this model was demonstrated, and a reflection on possible models in diabetic populations was described. The potential for use of this model in conjunction with current models is discussed, as well as the issues pertinent to such a basic model.


A Sustainability Index For Small Island Developing States., Philip Van Beynen, Fenda A. Akiwumi, Kaya Van Beynen Jan 2017

A Sustainability Index For Small Island Developing States., Philip Van Beynen, Fenda A. Akiwumi, Kaya Van Beynen

USF St. Petersburg campus Faculty Publications

This paper proposes a novel approach to measuring the progress of Small Island Developing States (SIDS) towards sustainable development (SD) as set by the UN Sustainable Development Goals 2030. Currently, these goals do not provide adequate guidance on how countries might measure their progress towards sustainability. We use these goals and a subset of their targets to develop an index with concrete targets, through the use of pertinent sustainability indicators, that SIDS should aim to achieve a sustainable society. In addition to the three categorical pillars of sustainable development (social, economic, and environmental), we included the category Climate Change and …


Light-Induced Protein Nitration And Degradation With Hono Emission, Hannah Meusel, Yasin Elshorbany, Uwe Kuhn, Thorsten Bartels-Rausch, Kathrin Reinmuth, Christopher J. Kampf, Yafang Cheng Jan 2017

Light-Induced Protein Nitration And Degradation With Hono Emission, Hannah Meusel, Yasin Elshorbany, Uwe Kuhn, Thorsten Bartels-Rausch, Kathrin Reinmuth, Christopher J. Kampf, Yafang Cheng

USF St. Petersburg campus Faculty Publications

Proteins can be nitrated by air pollutants (NO2), enhancing their allergenic potential. This work provides insight into protein nitration and subsequent decomposition in the presence of solar radiation. We also investigated light-induced formation of nitrous acid (HONO) from protein surfaces that were nitrated either online with instantaneous gas-phase exposure to NO2 or offline by an efficient nitration agent (tetranitromethane, TNM). Bovine serum albumin (BSA) and ovalbumin (OVA) were used as model substances for proteins. Nitration degrees of about 1% were derived applying NO2 concentrations of 100 ppb under VIS=UV illuminated conditions, while simultaneous decomposition of (nitrated) proteins was also found …


Silicate-Promoted Phosphorylation Of Glycerol In Non-Aqueous Solvents: A Prebiotically Plausible Route To Organophosphates, Maheen Gull, Brian J. Cafferty, Nicholas V. Hud, Matthew A. Pasek Jan 2017

Silicate-Promoted Phosphorylation Of Glycerol In Non-Aqueous Solvents: A Prebiotically Plausible Route To Organophosphates, Maheen Gull, Brian J. Cafferty, Nicholas V. Hud, Matthew A. Pasek

School of Geosciences Faculty and Staff Publications

Phosphorylation reactions of glycerol were studied using different inorganic phosphates such as sodium phosphate, trimetaphosphate (a condensed phosphate), and struvite. The reactions were carried out in two non-aqueous solvents: formamide and a eutectic solvent consisting of choline-chloride and glycerol in a ratio of 1:2.5. The glycerol reacted in formamide and in the eutectic solvent with phosphate to yield its phosphorylated derivatives in the presence of silicates such as quartz sand and kaolinite clay. The reactions were carried out by heating glycerol with a phosphate source at 85 °C for one week and were analyzed by 31P-nuclear magnetic resonance (NMR) spectroscopy …


A Special Issue Of Geosciences: Mapping And Assessing Natural Disasters Using Geospatial Technologies, Ruiliang Pu Jan 2017

A Special Issue Of Geosciences: Mapping And Assessing Natural Disasters Using Geospatial Technologies, Ruiliang Pu

School of Geosciences Faculty and Staff Publications

No abstract provided.


Inter-Calibration Of A Proposed New Primary Reference Standard Aa-Eth Zn For Zinc Isotopic Analysis, Corey Archer, Morten B. Anderson, Christophe Cloquet, Tim M. Conway, Shoufei Dong, Michael Ellwood, Rebekah Moore, Joey Nelson, Mark Rehkamper Jan 2017

Inter-Calibration Of A Proposed New Primary Reference Standard Aa-Eth Zn For Zinc Isotopic Analysis, Corey Archer, Morten B. Anderson, Christophe Cloquet, Tim M. Conway, Shoufei Dong, Michael Ellwood, Rebekah Moore, Joey Nelson, Mark Rehkamper

School of Geosciences Faculty and Staff Publications

We have prepared a large volume of pure, concentrated and homogenous zinc standard solution. This new standard solution is intended to be used as a primary reference standard for the zinc isotope community, and to serve as a replacement for the nearly exhausted current reference standard, the so-called JMC-Lyon Zn. The isotopic composition of this new zinc standard (AA-ETH Zn) has been determined through an inter-laboratory calibration exercise, calibrated against the existing JMC-Lyon standard, as well as the certified Zn reference standard IRMM-3702. The data show that the new standard is isotopically indistinguishable from the IRMM-3702 zinc standard, with a …


Water In Melt Inclusions From Phenocrysts Of Dacite Pumice Of The Vetrovoy Isthmus (Iturup Island, Southern Kuriles), A. A. Kotov, S. Z. Smirnov, I. A. Maksimovich, P. Y. Plechov, N. V. Chertkova, Aleksei I. Befus Jan 2017

Water In Melt Inclusions From Phenocrysts Of Dacite Pumice Of The Vetrovoy Isthmus (Iturup Island, Southern Kuriles), A. A. Kotov, S. Z. Smirnov, I. A. Maksimovich, P. Y. Plechov, N. V. Chertkova, Aleksei I. Befus

School of Geosciences Faculty and Staff Publications

This work is devoted to the study of one of the largest caldera eruptions of the Kurile-Kamchatka island-arc system that occurred on the island of Iturup. The object of investigation of this work are phenocrysts of quartz and plagioclase from dacite pumice of the Isthmus of the Isthmus, which is located on the island of Iturup. The purpose of this work is to determine the water content in the melts that participated in the caldera eruption of the Vetrovoy Isthmus and the patterns of their changes during the crystallization of magma. In the course of the work, the following were …


The Ribbed Drapery Of The Puerto Princesa Underground River (Palawan, Philippines): Morphology And Genesis, Paolo Forti, Giovanni Badino, Jose Maria Calaforra, Jo De Waele Dec 2016

The Ribbed Drapery Of The Puerto Princesa Underground River (Palawan, Philippines): Morphology And Genesis, Paolo Forti, Giovanni Badino, Jose Maria Calaforra, Jo De Waele

International Journal of Speleology

During the 2011 speleological expedition to the Puerto Princesa Underground River (Palawan, Philippines) a drapery characterized by several close-to-horizontal ribs has been noticed. Even without sampling and analyzing its internal growth layers, a detailed morphological study allowed to present a possible genetic model. The presented model helps to explain its evolution, which is mainly controlled by variation in water flow as a consequence of the Palawan climate. When validated by further analyses, the same genetic mechanism could define also the evolution of the very common but still unexplained complex flowstones, which exhibit several close-to-horizontal steps, widenings and narrowings along their …


Evaluating Machine Learning Classifiers For Defensive Cyber Operations, Michael D. Rich, Robert F. Mills, Thomas E. Dube, Steven K. Rogers Dec 2016

Evaluating Machine Learning Classifiers For Defensive Cyber Operations, Michael D. Rich, Robert F. Mills, Thomas E. Dube, Steven K. Rogers

Military Cyber Affairs

Today’s defensive cyber sensors are dominated by signature-based analytical methods that require continuous maintenance and lack the ability to detect unknown threats. Anomaly detection offers the ability to detect unknown threats, but despite over 15 years of active research, the operationalization of anomaly detection and machine learning for Defensive Cyber Operations (DCO) is lagging. This article provides an introduction to machine learning concepts with a focus on the unique challenges to using machine learning for DCO. Traditional machine learning evaluation methods are challenged in favor of a value-focused evaluation method that incorporates evaluator-specific weights for classifier and sensitivity threshold selection …


Military Cyber Professionals Have An Important Part To Play In The Obama-Trump Transition, Michael V. Hayden Dec 2016

Military Cyber Professionals Have An Important Part To Play In The Obama-Trump Transition, Michael V. Hayden

Military Cyber Affairs

Over the course of decades in service, I have experienced multiple presidential transitions. Each new Commander in Chief updates policies, personnel, and priorities…especially when the transition involves a new political party. In this respect, the current transition from the Obama to the Trump administration is no different. While this periodic exercise of our democracy may seem disruptive to some, it is a true opportunity for military cyber professionals to help shape our future national security posture.


Anomaly Detection From Hyperspectral Remote Sensing Imagery, Qiandong Guo, Ruiliang Pu, Jun Cheng Dec 2016

Anomaly Detection From Hyperspectral Remote Sensing Imagery, Qiandong Guo, Ruiliang Pu, Jun Cheng

School of Geosciences Faculty and Staff Publications

Hyperspectral remote sensing imagery contains much more information in the spectral domain than does multispectral imagery. The consecutive and abundant spectral signals provide a great potential for classification and anomaly detection. In this study, two real hyperspectral data sets were used for anomaly detection. One data set was an Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data covering the post-attack World Trade Center (WTC) and anomalies are fire spots. The other data set called SpecTIR contained fabric panels as anomalies compared to their background. Existing anomaly detection algorithms including the Reed–Xiaoli detector (RXD), the blocked adaptive computation efficient outlier nominator (BACON), the …


Lilliput Effect Dynamics Across The Cretaceous-Paleogene Mass Extinction: Approaches, Prevalence, And Mechanisms, Matthew Brett Jarrett Dec 2016

Lilliput Effect Dynamics Across The Cretaceous-Paleogene Mass Extinction: Approaches, Prevalence, And Mechanisms, Matthew Brett Jarrett

USF Tampa Graduate Theses and Dissertations

An organism's body size entails both physiological and ecological costs. Furthermore, as a parameter in analyzing organisms, it represents a fundamental and essential morphometric character. Reductions in size following mass extinction is a commonly observed phenomenon in the fossil record. This study examines the evolutionary significance of this phenomenon termed the: 'Lilliput Effect' by proposing that it represents a rapid evolutionary response to altered selection pressures during a mass extinction. This primary hypothesis is evaluated against two additional hypotheses of size reduction: 1) stunted growth as a response to stressed ecosystems, and/or 2) mass extinctions are size selective.

These hypotheses …


Recurring Patterns Among Scrambled Genes In The Encrypted Genome Of The Ciliate Oxytricha Trifallax, Jonathan Burns, Denys Kukushkin, Xiao Chen, Laura F Landweber, Masahico Saito, Nataša Jonoska Dec 2016

Recurring Patterns Among Scrambled Genes In The Encrypted Genome Of The Ciliate Oxytricha Trifallax, Jonathan Burns, Denys Kukushkin, Xiao Chen, Laura F Landweber, Masahico Saito, Nataša Jonoska

Mathematics and Statistics Faculty Publications

Some genera of ciliates, such as Oxytricha and Stylonychia, undergo massive genome reorganization during development and provide model organisms to study DNA rearrangement. A common feature of these ciliates is the presence of two types of nuclei: a germline micronucleus and a transcriptionally-active somatic macronucleus containing over 16,000 gene sized "nano-chromosomes". During conjugation the old parental macronucleus disintegrates and a new macronucleus forms from a copy of the zygotic micronucleus. During this process, macronuclear chromosomes assemble through DNA processing events that delete 90-98% of the DNA content of the micronucleus. This includes the deletion of noncoding DNA segments that interrupt …


Secondary Structure Adopted By The Gly-Gly-X Repetitive Regions Of Dragline Spider Silk, Geoffrey M Gray, Arjan Van Der Vaart, Chengchen Guo, Justin Jones, David Onofrei, Brian R Cherry, Randolph V Lewis, Jeffery L Yarger, Gregory P Holland Dec 2016

Secondary Structure Adopted By The Gly-Gly-X Repetitive Regions Of Dragline Spider Silk, Geoffrey M Gray, Arjan Van Der Vaart, Chengchen Guo, Justin Jones, David Onofrei, Brian R Cherry, Randolph V Lewis, Jeffery L Yarger, Gregory P Holland

Chemistry Faculty Publications

Solid-state NMR and molecular dynamics (MD) simulations are presented to help elucidate the molecular secondary structure of poly(Gly-Gly-X), which is one of the most common structural repetitive motifs found in orb-weaving dragline spider silk proteins. The combination of NMR and computational experiments provides insight into the molecular secondary structure of poly(Gly-Gly-X) segments and provides further support that these regions are disordered and primarily non-β-sheet. Furthermore, the combination of NMR and MD simulations illustrate the possibility for several secondary structural elements in the poly(Gly-Gly-X) regions of dragline silks, including β-turns, 3


Applying Ahp And Clustering Approaches For Public Transportation Decisionmaking: A Case Study Of Isfahan City, Alireza Salavati, Hossein Haghshenas, Bahador Ghadirifaraz, Jamshid Laghaei, Ghodrat Eftekhari Dec 2016

Applying Ahp And Clustering Approaches For Public Transportation Decisionmaking: A Case Study Of Isfahan City, Alireza Salavati, Hossein Haghshenas, Bahador Ghadirifaraz, Jamshid Laghaei, Ghodrat Eftekhari

Journal of Public Transportation

The main purpose of this paper is to define appropriate criteria for the systematic approach to evaluate and prioritize multiple candidate corridors for public transport investment simultaneously to serve travel demand, regarding supply of current public transportation system and road network conditions of Isfahan, Iran. To optimize resource allocation, policymakers need to identify proper corridors to implement a public transportation system. In fact, the main question is to adopt the best public transportation system for each main corridor of Isfahan. In this regard, 137 questionnaires were completed by experts, directors, and policymakers of Isfahan to identify goals and objectives in …


Random Walks In A Sparse Random Environment, Anastasios Matzavinos, Alexander Roitershtein, Youngsoo Seol Dec 2016

Random Walks In A Sparse Random Environment, Anastasios Matzavinos, Alexander Roitershtein, Youngsoo Seol

Mathematics and Statistics Faculty Publications

We introduce random walks in a sparse random environment on ℤ and investigate basic asymptotic properties of this model, such as recurrence-transience, asymptotic speed, and limit theorems in both the transient and recurrent regimes. The new model combines features of several existing models of random motion in random media and admits a transparent physical interpretation. More specifically, a random walk in a sparse random environment can be characterized as a “locally strong” perturbation of a simple random walk by a random potential induced by “rare impurities,” which are randomly distributed over the integer lattice. Interestingly, in the critical (recurrent) regime, …