Proposals
Below are some proposals for talks from the past (and current). By clicking on the ID number, more details are shown. By default, these are sorted chronologically (recent first) and by then by last name. The data can be sorted by alternate means by using the links at the top right, each allowing ascending or descending orders.
Displaying 461-471 of 471 results.
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ID:
314
Year: 2011
Name: Bill Wood
Institution: University of Northern Iowa
Subject area(s): calculus
Title of Talk: Squigonometry: Developing non-euclidean trigonometry with elementary calculus
Abstract: Differential equations offers one approach to defining the classical trigonometric functions sine and cosine that parameterize the unit circle. We adapt this approach to develop analogous functions that parameterize the unit "squircle" defined by $x^4+y^4=1$. As we develop our new theory of "squigonometry" using only elementary calculus, we will catch glimpses of some very interesting and deep ideas in elliptic integrals, non-euclidean geometry, number theory, and complex analysis.
Year: 2011
Name: Bill Wood
Institution: University of Northern Iowa
Subject area(s): calculus
Title of Talk: Squigonometry: Developing non-euclidean trigonometry with elementary calculus
Abstract: Differential equations offers one approach to defining the classical trigonometric functions sine and cosine that parameterize the unit circle. We adapt this approach to develop analogous functions that parameterize the unit "squircle" defined by $x^4+y^4=1$. As we develop our new theory of "squigonometry" using only elementary calculus, we will catch glimpses of some very interesting and deep ideas in elliptic integrals, non-euclidean geometry, number theory, and complex analysis.
ID:
133
Year: 2005
Name: Phil Wood
Institution:
Subject area(s): Calculus
Title of Talk: Simple Teaching of Differential Calculus
Abstract: Calculus may be taught more understandably by first describing its practical uses and then presenting it as simple algebra and geometry. In doing this all mention of infinitesimals, increments, theory of limits and formal proofs has been eliminated.
Year: 2005
Name: Phil Wood
Institution:
Subject area(s): Calculus
Title of Talk: Simple Teaching of Differential Calculus
Abstract: Calculus may be taught more understandably by first describing its practical uses and then presenting it as simple algebra and geometry. In doing this all mention of infinitesimals, increments, theory of limits and formal proofs has been eliminated.
ID:
147
Year: 2006
Name: Scott Wood
Institution: University of Iowa
Subject area(s): Bayesian statistics, spatial statistics, medical geography
Title of Talk: Model Fitting and Selection for County-Level Depression Hospitalization Rates Using Bayesian Statistical Methods
Abstract: Researchers in the health sciences are interested in identifying and modeling the risk factors that are associated with high rates of hospitalization for depression. Being able to identify U.S. counties with high standardized hospitalization rates (SHR) would be useful in allocating federal resources. This project analyzes and critiques three potential Bayesian statistical models that can be implemented using WinBUGS software. Ordinary least squares, Poisson regression, and Bayesian conditional autoregressive (CAR) models are considered in detail. Though each has its advantages and disadvantages, qualitative and quantitative evidence suggest that the Bayesian CAR model is the optimal choice for this data. While a Bayesian CAR model will be shown to account for spatial autocorrelation and Poisson response variables, it was not as reliable as hoped for making accurate predictions at the county level.
Year: 2006
Name: Scott Wood
Institution: University of Iowa
Subject area(s): Bayesian statistics, spatial statistics, medical geography
Title of Talk: Model Fitting and Selection for County-Level Depression Hospitalization Rates Using Bayesian Statistical Methods
Abstract: Researchers in the health sciences are interested in identifying and modeling the risk factors that are associated with high rates of hospitalization for depression. Being able to identify U.S. counties with high standardized hospitalization rates (SHR) would be useful in allocating federal resources. This project analyzes and critiques three potential Bayesian statistical models that can be implemented using WinBUGS software. Ordinary least squares, Poisson regression, and Bayesian conditional autoregressive (CAR) models are considered in detail. Though each has its advantages and disadvantages, qualitative and quantitative evidence suggest that the Bayesian CAR model is the optimal choice for this data. While a Bayesian CAR model will be shown to account for spatial autocorrelation and Poisson response variables, it was not as reliable as hoped for making accurate predictions at the county level.
ID:
336
Year: 2012
Name: Kelly Woodard
Institution: Simpson College
Subject area(s): Combinatorics
Title of Talk: Beggar Your Neighbor, The Search for an Infinite Game
Abstract: In this talk we will present the work completed in the summer of 2012 during the Dr. Albert H. and Greta A. Bryan Summer Research Program at Simpson College. We furthered the analysis of the card game Beggar-My-Neighbor specifically with the intent of discovering a deal that leads to an infinite game in a 52-card deck. We used combinatorics and programs written in Mathematica to examine and refine the large number of possible deals based on structures that lead to cyclic behavior.
Year: 2012
Name: Kelly Woodard
Institution: Simpson College
Subject area(s): Combinatorics
Title of Talk: Beggar Your Neighbor, The Search for an Infinite Game
Abstract: In this talk we will present the work completed in the summer of 2012 during the Dr. Albert H. and Greta A. Bryan Summer Research Program at Simpson College. We furthered the analysis of the card game Beggar-My-Neighbor specifically with the intent of discovering a deal that leads to an infinite game in a 52-card deck. We used combinatorics and programs written in Mathematica to examine and refine the large number of possible deals based on structures that lead to cyclic behavior.
ID:
155
Year: 2006
Name: Di Wu
Institution: Iowa State University
Subject area(s): Computational Biology and Applied Mathematics
Title of Talk: Protein Structure Determination: A Rigid Geometric Build-up Algorithm for Solving a Distance Geometry Problem with Sparse Exact Distance Data
Abstract: Protein Structure Determination: A Rigid Geometric Build-up Algorithm for Solving a Distance Geometry Problem with Sparse Exact Distance Data Di Wu and Zhijun Wu Program on Bioinformatics and Computational Biology Department of Mathematics Iowa State University Ames, Iowa 50011 Abstract. Given a set of distances for certain pairs of atoms in a protein, the coordinates of the atoms and hence the protein structure can then be determined through solving a so-called distance geometry problem. However, it has been proved to be a NP hard problem when only a set of partial distances given. Previously, we used a so-called geometric build-up approach to develop several algorithms for solving the distance geometry problem with a set of sparse distance data. In this method, the coordinates of the atoms in a protein are determined as one atom at a time, with the distances from four base atoms to the atom to be determined. However, the requirement for four base atoms for the unique determination of each atom is sufficient, but unnecessary and even redundant for rigid structural determination. Here we investigate a rigid geometric build-up algorithm, which requires three base atoms instead of four base atoms for the determination of each atom. It could generate rigid structures, even a unique structure for very sparse distance data of a protein eventually. Due to the reflection in the determination for some atoms, this algorithm may also produce multiple structures satisfying given distances. We present the results obtained by using the algorithm for the determination of the structures, which suggests the potential of applying the algorithm to the distance based protein structural modeling.
Year: 2006
Name: Di Wu
Institution: Iowa State University
Subject area(s): Computational Biology and Applied Mathematics
Title of Talk: Protein Structure Determination: A Rigid Geometric Build-up Algorithm for Solving a Distance Geometry Problem with Sparse Exact Distance Data
Abstract: Protein Structure Determination: A Rigid Geometric Build-up Algorithm for Solving a Distance Geometry Problem with Sparse Exact Distance Data Di Wu and Zhijun Wu Program on Bioinformatics and Computational Biology Department of Mathematics Iowa State University Ames, Iowa 50011 Abstract. Given a set of distances for certain pairs of atoms in a protein, the coordinates of the atoms and hence the protein structure can then be determined through solving a so-called distance geometry problem. However, it has been proved to be a NP hard problem when only a set of partial distances given. Previously, we used a so-called geometric build-up approach to develop several algorithms for solving the distance geometry problem with a set of sparse distance data. In this method, the coordinates of the atoms in a protein are determined as one atom at a time, with the distances from four base atoms to the atom to be determined. However, the requirement for four base atoms for the unique determination of each atom is sufficient, but unnecessary and even redundant for rigid structural determination. Here we investigate a rigid geometric build-up algorithm, which requires three base atoms instead of four base atoms for the determination of each atom. It could generate rigid structures, even a unique structure for very sparse distance data of a protein eventually. Due to the reflection in the determination for some atoms, this algorithm may also produce multiple structures satisfying given distances. We present the results obtained by using the algorithm for the determination of the structures, which suggests the potential of applying the algorithm to the distance based protein structural modeling.
ID:
462
Year: 2016
Name: ypmvqq ypmvqq
Institution: raCweZrhMNjKxbics
Subject area(s): UvVwwTilpXhZkD
Title of Talk: VgMIpGhcdwlkdWXBUw
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Year: 2016
Name: ypmvqq ypmvqq
Institution: raCweZrhMNjKxbics
Subject area(s): UvVwwTilpXhZkD
Title of Talk: VgMIpGhcdwlkdWXBUw
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ID:
506
Year: 2018
Name: Joshua Zelinsky
Institution: ISU
Subject area(s): Number theory
Title of Talk: Lower and upper bounds in integer complexity.
Abstract: Define ||n|| to be the complexity of n, the smallest number of 1's needed to write n using an arbitrary combination of addition and multiplication. John Selfridge showed that ||n|| is at least 3log3n for all n, and this lower bound is obtained exactly when n is a power of 3. Richard Guy noted the trivial upper bound of 3log_2 n for all n bigger than 1, by writing n in base 2. This talk will discuss work improving the upper bound, as well as work leading to a complete classification of numbers whose complexity is close to the lower bound. Along the way, we'll develop connections to both ordinal numbers and the p-adics.
Year: 2018
Name: Joshua Zelinsky
Institution: ISU
Subject area(s): Number theory
Title of Talk: Lower and upper bounds in integer complexity.
Abstract: Define ||n|| to be the complexity of n, the smallest number of 1's needed to write n using an arbitrary combination of addition and multiplication. John Selfridge showed that ||n|| is at least 3log3n for all n, and this lower bound is obtained exactly when n is a power of 3. Richard Guy noted the trivial upper bound of 3log_2 n for all n bigger than 1, by writing n in base 2. This talk will discuss work improving the upper bound, as well as work leading to a complete classification of numbers whose complexity is close to the lower bound. Along the way, we'll develop connections to both ordinal numbers and the p-adics.
ID:
527
Year: 2019
Name: Hongyuan Zhang
Institution: Grinnell College
Subject area(s): applied topology
Title of Talk: Artworks and Articles Meet Mapper and Persistent Homology
Abstract: Since its recent birth, topological data analysis (TDA) has proven to be a very useful tool when studying large and high-dimensional data sets. We will talk about the application of two TDA tools, persistent homology and the Mapper algorithm, to the Metropolitan Museum of Art (MET) artwork data set and two scholarly literature databases: arXiv and Google Scholar. For the MET data, we use the Mapper Algorithm to guide feature selection in building a logistic regression model for classifying certain artworks. Then we use persistent homology to help differentiate between two subsets of artwork. For the arXiv data, we use persistent homology to derive a general sense of the shape of the data. With help of the Mapper Algorithm, we further explore the point cloud by analyzing trends and features in visualizations. For the Google Scholar data, we find that there are interesting correlations between academic category of the paper and number of pages, number of references, and published date.
Year: 2019
Name: Hongyuan Zhang
Institution: Grinnell College
Subject area(s): applied topology
Title of Talk: Artworks and Articles Meet Mapper and Persistent Homology
Abstract: Since its recent birth, topological data analysis (TDA) has proven to be a very useful tool when studying large and high-dimensional data sets. We will talk about the application of two TDA tools, persistent homology and the Mapper algorithm, to the Metropolitan Museum of Art (MET) artwork data set and two scholarly literature databases: arXiv and Google Scholar. For the MET data, we use the Mapper Algorithm to guide feature selection in building a logistic regression model for classifying certain artworks. Then we use persistent homology to help differentiate between two subsets of artwork. For the arXiv data, we use persistent homology to derive a general sense of the shape of the data. With help of the Mapper Algorithm, we further explore the point cloud by analyzing trends and features in visualizations. For the Google Scholar data, we find that there are interesting correlations between academic category of the paper and number of pages, number of references, and published date.
ID:
159
Year: 2006
Name: WEN ZHOU
Institution: Iowa State University
Subject area(s):
Title of Talk: Chemotactic Collapse in Keller-Segel Equation
Abstract: Chemotaxis phenomenon is one of the most fundamental phenomenons in the biology field. In 1970s, Keller and Segel characterize this phenomenon with two coupled equations. Study on the blow up of the solutions of the this equation is one of the key part of the research on this equation. This short talk will briefly introduce some recent results of the study on this equation, including Nagai, Velazquez, Stevens, Levine, and Hortsman's work, etc.
Year: 2006
Name: WEN ZHOU
Institution: Iowa State University
Subject area(s):
Title of Talk: Chemotactic Collapse in Keller-Segel Equation
Abstract: Chemotaxis phenomenon is one of the most fundamental phenomenons in the biology field. In 1970s, Keller and Segel characterize this phenomenon with two coupled equations. Study on the blow up of the solutions of the this equation is one of the key part of the research on this equation. This short talk will briefly introduce some recent results of the study on this equation, including Nagai, Velazquez, Stevens, Levine, and Hortsman's work, etc.
ID:
543
Year: 2019
Name: Valorie Zonnefeld
Institution: Dordt University
Subject area(s): Pedagogy of Mathematics
Title of Talk: Classroom Environments that Nurture a Growth Mindset
Abstract: Carol Dweck and Jo Boaler's landmark research regarding the importance of a growth mindset for learning and specifically mathematics is a game changer for professors and teachers. Learn what a growth mindset is and how to foster it in your classroom.
Year: 2019
Name: Valorie Zonnefeld
Institution: Dordt University
Subject area(s): Pedagogy of Mathematics
Title of Talk: Classroom Environments that Nurture a Growth Mindset
Abstract: Carol Dweck and Jo Boaler's landmark research regarding the importance of a growth mindset for learning and specifically mathematics is a game changer for professors and teachers. Learn what a growth mindset is and how to foster it in your classroom.
ID:
566
Year: 2021
Name: Zonghao Zou
Institution: Santa Clara University
Subject area(s):
Title of Talk: Helical trajectories of swimming cells with a flexible flagellar hook
Abstract: The flexibility of the bacterial flagellar hook is believed to have substantial consequences for microorganism locomotion. Using a simplified model of a rigid flagellum and a flexible hook, we show that the paths of axisymmetric cell bodies driven by a single flagellum in Stokes flow are generically helical. Phase-averaged resistance and mobility tensors are produced to describe the flagellar hydrodynamics, and a helical rod model which retains a coupling between translation and rotation is identified as a distinguished asymptotic limit. A supercritical Hopf bifurcation in the flagellar orientation beyond a critical ratio of flagellar motor torque to hook bending stiffness, which is set by the spontaneous curvature of the flexible hook, the shape of the cell body, and the flagellum geometry, can have a dramatic effect on the cell's trajectory through the fluid. Although the equilibrium hook angle can result in a wide variance in the trajectory's helical pitch, we find a very consistent prediction for the trajectory's helical amplitude using parameters relevant to swimming P. aeruginosa cells.
Year: 2021
Name: Zonghao Zou
Institution: Santa Clara University
Subject area(s):
Title of Talk: Helical trajectories of swimming cells with a flexible flagellar hook
Abstract: The flexibility of the bacterial flagellar hook is believed to have substantial consequences for microorganism locomotion. Using a simplified model of a rigid flagellum and a flexible hook, we show that the paths of axisymmetric cell bodies driven by a single flagellum in Stokes flow are generically helical. Phase-averaged resistance and mobility tensors are produced to describe the flagellar hydrodynamics, and a helical rod model which retains a coupling between translation and rotation is identified as a distinguished asymptotic limit. A supercritical Hopf bifurcation in the flagellar orientation beyond a critical ratio of flagellar motor torque to hook bending stiffness, which is set by the spontaneous curvature of the flexible hook, the shape of the cell body, and the flagellum geometry, can have a dramatic effect on the cell's trajectory through the fluid. Although the equilibrium hook angle can result in a wide variance in the trajectory's helical pitch, we find a very consistent prediction for the trajectory's helical amplitude using parameters relevant to swimming P. aeruginosa cells.