Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Hemodynamics (3)
- Cerebral aneurysm (2)
- Dynamical systems (2)
- Morphology (2)
- Prediction (2)
-
- Rupture (2)
- 62G10 (1)
- 62J10 (1)
- Accelerometer (1)
- Agent-based model (1)
- Aneurysm (1)
- Big data (1)
- Bit error ratios (1)
- Borrowing capacity (1)
- Challenge (1)
- Computational fluid dynamics (1)
- Contagion (1)
- Epidemiology (1)
- Escape (1)
- Extinction (1)
- Fiducial distribution (1)
- Financial instability (1)
- Financial stability (1)
- Generalized pivotal quantity (1)
- Generalized test variable (1)
- Intracranial aneurysm (1)
- Large deviation theory (1)
- Mean exit time (1)
- Mode-locked lasers (1)
- Noise-induced transitions (1)
- Publication
- Publication Type
Articles 1 - 18 of 18
Full-Text Articles in Physical Sciences and Mathematics
Multiple Aneurysms Anatomy Challenge 2018 (Match): Phase I: Segmentation, Philipp Berg, Samuel Voß, Sylvia Saalfeld, Gábor Janiga, Aslak W. Bergersen, Kristian Valen-Sendstad, Jan Bruening, Leonid Goubergrits, Andreas Spuler, Nicole M. Cancelliere, David A. Steinman, Vitor M. Pereira, Tin Lok Chiu, Anderson Chun On Tsang, Bong Jae Chung, Juan R. Cebral, Salvatore Cito, Jordi Pallarès, Gabriele Copelli, Benjamin Csippa, György Paál, Soichiro Fujimura, Hiroyuki Takao, Simona Hodis, Georg Hille, Christof Karmonik, Saba Elias, Kerstin Kellermann, Muhammad Owais Khan, Alison L. Marsden
Multiple Aneurysms Anatomy Challenge 2018 (Match): Phase I: Segmentation, Philipp Berg, Samuel Voß, Sylvia Saalfeld, Gábor Janiga, Aslak W. Bergersen, Kristian Valen-Sendstad, Jan Bruening, Leonid Goubergrits, Andreas Spuler, Nicole M. Cancelliere, David A. Steinman, Vitor M. Pereira, Tin Lok Chiu, Anderson Chun On Tsang, Bong Jae Chung, Juan R. Cebral, Salvatore Cito, Jordi Pallarès, Gabriele Copelli, Benjamin Csippa, György Paál, Soichiro Fujimura, Hiroyuki Takao, Simona Hodis, Georg Hille, Christof Karmonik, Saba Elias, Kerstin Kellermann, Muhammad Owais Khan, Alison L. Marsden
Department of Applied Mathematics and Statistics Faculty Scholarship and Creative Works
Purpose: Advanced morphology analysis and image-based hemodynamic simulations are increasingly used to assess the rupture risk of intracranial aneurysms (IAs). However, the accuracy of those results strongly depends on the quality of the vessel wall segmentation. Methods: To evaluate state-of-the-art segmentation approaches, the Multiple Aneurysms AnaTomy CHallenge (MATCH) was announced. Participants carried out segmentation in three anonymized 3D DSA datasets (left and right anterior, posterior circulation) of a patient harboring five IAs. Qualitative and quantitative inter-group comparisons were carried out with respect to aneurysm volumes and ostia. Further, over- and undersegmentation were evaluated based on highly resolved 2D images. Finally, …
Development And Internal Validation Of An Aneurysm Rupture Probability Model Based On Patient Characteristics And Aneurysm Location, Morphology, And Hemodynamics, Felicitas J. Detmer, Bong Jae Chung, Fernando Mut, Martin Slawski, Farid Hamzei-Sichani, Christopher Putman, Carlos Jiménez, Juan R. Cebral
Development And Internal Validation Of An Aneurysm Rupture Probability Model Based On Patient Characteristics And Aneurysm Location, Morphology, And Hemodynamics, Felicitas J. Detmer, Bong Jae Chung, Fernando Mut, Martin Slawski, Farid Hamzei-Sichani, Christopher Putman, Carlos Jiménez, Juan R. Cebral
Department of Applied Mathematics and Statistics Faculty Scholarship and Creative Works
Purpose: Unruptured cerebral aneurysms pose a dilemma for physicians who need to weigh the risk of a devastating subarachnoid hemorrhage against the risk of surgery or endovascular treatment and their complications when deciding on a treatment strategy. A prediction model could potentially support such treatment decisions. The aim of this study was to develop and internally validate a model for aneurysm rupture based on hemodynamic and geometric parameters, aneurysm location, and patient gender and age. Methods: Cross-sectional data from 1061 patients were used for image-based computational fluid dynamics and shape characterization of 1631 aneurysms for training an aneurysm rupture probability …
Hemodynamic Characteristics Of Stable And Unstable Vertebrobasilar Dolichoectatic And Fusiform Aneurysms, Waleed Brinjikji, Bong Jae Chung, Ding Yong-Hong, John T. Wald, Fernando Mut, Ramanathan Kadirvel, David F. Kallmes, Aymeric Rouchaud, Giuseppe Lanzino, Juan R. Cebral
Hemodynamic Characteristics Of Stable And Unstable Vertebrobasilar Dolichoectatic And Fusiform Aneurysms, Waleed Brinjikji, Bong Jae Chung, Ding Yong-Hong, John T. Wald, Fernando Mut, Ramanathan Kadirvel, David F. Kallmes, Aymeric Rouchaud, Giuseppe Lanzino, Juan R. Cebral
Department of Applied Mathematics and Statistics Faculty Scholarship and Creative Works
Background and purpose Vertebrobasilar dolichoectatic and fusiform aneurysms (VBDAs) are known to have a poor natural history, with high rates of growth, rupture, and stroke. The purpose of this study was to identify hemodynamic characteristics that differ between VBDAs associated with growth, rupture, and stroke. Materials and methods VBDAs with CT angiography or MR angiography followed longitudinally without treatment were studied. Unstable aneurysms were defined as those that grew or ruptured during follow-up. Aneurysms associated with stroke were defined as those associated with posterior circulation infarct at follow-up. Baseline data, including demographics, comorbidities, and aneurysm morphology and size were collected. …
Identification Of Hostile Hemodynamics And Geometries Of Cerebral Aneurysms: A Case-Control Study, Bong Jae Chung, F. Mut, C. M. Putman, F. Hamzei-Sichani, W. Brinjikji, D. Kallmes, C. M. Jimenez, Juan R. Cebral
Identification Of Hostile Hemodynamics And Geometries Of Cerebral Aneurysms: A Case-Control Study, Bong Jae Chung, F. Mut, C. M. Putman, F. Hamzei-Sichani, W. Brinjikji, D. Kallmes, C. M. Jimenez, Juan R. Cebral
Department of Applied Mathematics and Statistics Faculty Scholarship and Creative Works
BACKGROUND AND PURPOSE: Hostile hemodynamic conditions and geometries are thought to predispose aneurysms for instability and rupture. This study compares stable, unstable, and ruptured aneurysms while controlling for location and patient characteristics. MATERIALS AND METHODS: The hemodynamics and geometries of 165 stable, 65 unstable, and 554 ruptured aneurysms were compared. Hemodynamics was modeled using image-based computational fluid dynamics. Case-control pairs were selected matching aneurysm location, patient age, and sex. Paired Wilcoxon tests were used to compare hemodynamic and geometric variables among different aneurysm groups. The pairing was repeated 100 times, and the combined P values were calculated and adjusted for …
Masked Instability: Within-Sector Financial Risk In The Presence Of Wealth Inequality, Youngna Choi
Masked Instability: Within-Sector Financial Risk In The Presence Of Wealth Inequality, Youngna Choi
Department of Applied Mathematics and Statistics Faculty Scholarship and Creative Works
We investigate masked financial instability caused by wealth inequality. When an economic sector is decomposed into two subsectors that possess a severe wealth inequality, the sector in entirety can look financially stable while the two subsectors possess extreme financially instabilities of opposite nature, one from excessive equity, the other from lack thereof. The unstable subsector can result in further financial distress and even trigger a financial crisis. The market instability indicator, an early warning system derived from dynamical systems applied to agent-based models, is used to analyze the subsectoral financial instabilities. Detailed mathematical analysis is provided to explain what financial …
Understanding The Flow Structure Of Low Reynolds Number Flows, Albert Jarvis
Understanding The Flow Structure Of Low Reynolds Number Flows, Albert Jarvis
Theses, Dissertations and Culminating Projects
Ocean flows and the mechanisms by which their contents are organized has been a longstanding area of interest in applied mathematics. In recent years, a new theory has been developed to identify the structures responsible for the organization of fluid particles within complex geophysical flows. This theory is known as the theory of Lagrangian Coherent Structures (LCS) and details which structures are responsible for the organization of the flow and how to identify them. Being able to identify these LCS in real time has far reaching implications ranging from developing strategies for search and rescue missions to identifying the best …
Development Of A Statistical Model For Discrimination Of Rupture Status In Posterior Communicating Artery Aneurysms, Felicitas J. Detmer, Bong Jae Chung, Fernando Mut, Michael Pritz, Martin Slawski, Farid Hamzei-Sichani, David Kallmes, Christopher Putman, Carlos Jimenez, Juan R. Cebral
Development Of A Statistical Model For Discrimination Of Rupture Status In Posterior Communicating Artery Aneurysms, Felicitas J. Detmer, Bong Jae Chung, Fernando Mut, Michael Pritz, Martin Slawski, Farid Hamzei-Sichani, David Kallmes, Christopher Putman, Carlos Jimenez, Juan R. Cebral
Department of Applied Mathematics and Statistics Faculty Scholarship and Creative Works
Background: Intracranial aneurysms at the posterior communicating artery (PCOM) are known to have high rupture rates compared to other locations. We developed and internally validated a statistical model discriminating between ruptured and unruptured PCOM aneurysms based on hemodynamic and geometric parameters, angio-architectures, and patient age with the objective of its future use for aneurysm risk assessment. Methods: A total of 289 PCOM aneurysms in 272 patients modeled with image-based computational fluid dynamics (CFD) were used to construct statistical models using logistic group lasso regression. These models were evaluated with respect to discrimination power and goodness of fit using tenfold nested …
Dynamics Of Coupled Particles In A Time-Dependent, Double-Gyre Flow, Manuel Albrizzio
Dynamics Of Coupled Particles In A Time-Dependent, Double-Gyre Flow, Manuel Albrizzio
Theses, Dissertations and Culminating Projects
We consider a time-dependent, wind-driven, stochastic double-gyre flow, and investigate the interaction between the flow and coupled particles operating within the flow. It is known that noise can cause individual particles to escape from one gyre to another gyre. By computing the Lagrangian coherent structures (LCS) of the system, one can determine low and high probability regions of particle escape. We adjust the coupling between two particles, and study the effect on particle escape for a variety of initial conditions and noise intensities.
Fiducial Generalized P-Values For Testing Zero-Variance Components In Linear Mixed-Effects Models, Xinmin Li, Haiyan Su, Hua Liang
Fiducial Generalized P-Values For Testing Zero-Variance Components In Linear Mixed-Effects Models, Xinmin Li, Haiyan Su, Hua Liang
Department of Applied Mathematics and Statistics Faculty Scholarship and Creative Works
Linear mixed-effects models are widely used in analysis of longitudinal data. However, testing for zero-variance components of random effects has not been well resolved in statistical literature, although some likelihood-based procedures have been proposed and studied. In this article, we propose a generalized p-value based method in coupling with fiducial inference to tackle this problem. The proposed method is also applied to test linearity of the nonparametric functions in additive models. We provide theoretical justifications and develop an implementation algorithm for the proposed method. We evaluate its finite-sample performance and compare it with that of the restricted likelihood ratio test …
Masked Instability: Within-Sector Financial Risk In The Presence Of Wealth Inequality, Youngna Choi
Masked Instability: Within-Sector Financial Risk In The Presence Of Wealth Inequality, Youngna Choi
Department of Applied Mathematics and Statistics Faculty Scholarship and Creative Works
We investigate masked financial instability caused by wealth inequality. When an economic sector is decomposed into two subsectors that possess a severe wealth inequality, the sector in entirety can look financially stable while the two subsectors possess extreme financially instabilities of opposite nature, one from excessive equity, the other from lack thereof. The unstable subsector can result in further financial distress and even trigger a financial crisis. The market instability indicator, an early warning system derived from dynamical systems applied to agent-based models, is used to analyze the subsectoral financial instabilities. Detailed mathematical analysis is provided to explain what financial …
Analysis Of Daily Precipitation Data From Selected Sites In The United States, Sahar Ahmed
Analysis Of Daily Precipitation Data From Selected Sites In The United States, Sahar Ahmed
Theses, Dissertations and Culminating Projects
Global warming is a contentious topic since modern climate records only exist for the last 100 years in contrast to ice-core analysis that establishes ice ages tens of thousands of years ago. Nevertheless, patterns associated with events such as El Niño Southern Oscillation (ENSO), precipitation, tornadoes, and snowfall amounts over the last century can provide a useful and objective indicator of climate “change”. This project focuses on daily precipitation totals for the state of New Jersey over the last 100 to 150 years from nineteen meteorological recording stations and involves large data sets with a million observations. This research utilizes …
Inertial Particle Transport By Lagrangian Coherent Structures In Geophysical Flows, Alexa Aucoin
Inertial Particle Transport By Lagrangian Coherent Structures In Geophysical Flows, Alexa Aucoin
Theses, Dissertations and Culminating Projects
Lagrangian Coherent Structures (LCS) provide a skeleton for the underlying structures in geophysical flows. It is known that LCS govern the movement of fluid particles within a flow, but it is not well understood how these same LCS influence the movement of inertial particles within a fluid flow. In this thesis, we consider two geophysical flows, the double-gyre model, and a single-layer quasi-geostrophic PDE model. In particular, we use finite-time Lyapunov exponents (FTLE) to characterize the attracting and repelling LCS for these models and show how inertial particles aggregate with respect to LCS. We numerically investigate the dynamics of inertial …
Seasonal Switching Affects Bacterial-Fungal Dominance In An Ecological System, Kristin Carfora
Seasonal Switching Affects Bacterial-Fungal Dominance In An Ecological System, Kristin Carfora
Theses, Dissertations and Culminating Projects
We consider a model inspired by producer-herbivore-decomposer soil food webs and determine the effect of ecological parameters on the decomposer pool. In particular, we observe how seasonal changes in the stoichiometric quality of the producer coupled with the efficiency of herbivory over the calendar year can induce a shift in the composition of the decomposer pool. Decomposers have a significant effect on the movement of essential nutrients throughout an ecosystem; we further determine how this shift between a bacterially dominated decomposer pool and a fungally dominated pool affects primary production and relative distribution of biomass of the other compartments.
A Practical Guide To Big Data, Ekaterina Smirnova, Andrada Ivanescu, Jiawei Bai, Ciprian M. Crainiceanu
A Practical Guide To Big Data, Ekaterina Smirnova, Andrada Ivanescu, Jiawei Bai, Ciprian M. Crainiceanu
Department of Applied Mathematics and Statistics Faculty Scholarship and Creative Works
Big Data is increasingly prevalent in science and data analysis. We provide a short tutorial for adapting to these changes and making the necessary adjustments to the academic culture to keep Biostatistics truly impactful in scientific research.
Simplicity And Sustainability: Pointers From Ethics And Science, Mehrdad Massoudi, Ashwin Vaidya
Simplicity And Sustainability: Pointers From Ethics And Science, Mehrdad Massoudi, Ashwin Vaidya
Department of Mathematics Facuty Scholarship and Creative Works
In this paper, we explore the notion of simplicity. We use definitions of simplicity proposed by philosophers, scientists, and economists. In an age when the rapidly growing human population faces an equally rapidly declining energy/material resources, there is an urgent need to consider various notions of simplicity, collective and individual, which we believe to be a sensible path to restore our planet to a reasonable state of health. Following the logic of mathematicians and physicists, we suggest that simplicity can be related to sustainability. Our efforts must therefore not be spent so much in pursuit of growth but in achieving …
The Mechanics And Thermodynamics Of Amyloid Beta Protein Aggregation In Competing Pathways, Edward Steen
The Mechanics And Thermodynamics Of Amyloid Beta Protein Aggregation In Competing Pathways, Edward Steen
Theses, Dissertations and Culminating Projects
The primary purpose of this paper is to investigate the mechanics of Aβ protein aggregation within the brain through mathematical modeling and simulation. Aggregation of Aβ is the cause of plaques within the brain of Alzheimer’s Disease sufferers. Because the pathways of aggregation from monomer to oligomer to polymer are numerous and complex, we have had to simplify our model to a limited number of species. Of great concern, too, is the process by which Aβ can form as “off-pathway” species, which is when Aβ reacts with fatty acid micelles. It is this species of Aβ, which due to its …
Borrowing Capacity, Financial Instability, And Contagion: Case Study Of The U.S. Subprime Mortgage Crisis, Youngna Choi
Borrowing Capacity, Financial Instability, And Contagion: Case Study Of The U.S. Subprime Mortgage Crisis, Youngna Choi
Department of Applied Mathematics and Statistics Faculty Scholarship and Creative Works
In this paper we study an agent-based model of economy to investigate the impact of borrowing capacity on financial instability and contagion. We divide an economy into agents that interact via flow of funds and express the financial instability level of each agent as a function of the time derivatives of its wealth, cash inflows, and borrowing capacity. We show that among these factors the borrowing capacity, which itself is determined by other economic constraints, aects the most the financial instability, and it can even cause contagion through feedback loop formed by flow of funds. We use historical time series …
A Primer On Noise-Induced Transitions In Applied Dynamical Systems, Eric Forgoston, Richard O. Moore
A Primer On Noise-Induced Transitions In Applied Dynamical Systems, Eric Forgoston, Richard O. Moore
Department of Applied Mathematics and Statistics Faculty Scholarship and Creative Works
Noise plays a fundamental role in a wide variety of physical and biological dynamical systems. It can arise from an external forcing or due to random dynamics internal to the system. It is well established that even weak noise can result in large behavioral changes such as transitions between or escapes from quasi-stable states. These transitions can correspond to critical events such as failures or extinctions that make them essential phenomena to understand and quantify, despite the fact that their occurrence is rare. This article will provide an overview of the theory underlying the dynamics of rare events for stochastic …