A5018976216- COVID-19 epidemiological studies
- Herpesvirus Infections and Treatments
- Mosquito-borne diseases and control
- Stochastic processes and statistical mechanics
- Hepatitis Viruses Studies and Epidemiology
- Malaria Research and Control
- Tribology and Wear Analysis
- Viral Infections and Outbreaks Research
- Advanced Harmonic Analysis Research
- Data-Driven Disease Surveillance
- Aluminum Alloys Composites Properties
- Animal Virus Infections Studies
- Markov Chains and Monte Carlo Methods
- HIV/AIDS Research and Interventions
- Census and Population Estimation
- Advanced Theoretical and Applied Studies in Material Sciences and Geometry
- Virology and Viral Diseases
- Fractional Differential Equations Solutions
- Holomorphic and Operator Theory
- Polymer Nanocomposite Synthesis and Irradiation
- Polymer Nanocomposites and Properties
- Freshwater macroinvertebrate diversity and ecology
- HIV, Drug Use, Sexual Risk
- Probability and Risk Models
- Magnesium Alloys: Properties and Applications
Columbia University
2024-2025
Yonsei University
2013-2024
Grand Valley State University
2010-2021
Severance Hospital
2021
Materials Science & Engineering
2015
University of Illinois System
2006
Purdue University West Lafayette
2004-2006
The 2019 emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its rapid spread created a public health emergency international concern. However, the impact pandemic in Sub-Saharan Africa, as documented cases, hospitalizations deaths, appears far lower than Americas, Europe Asia. Characterization transmission dynamics is critical for understanding how SARS-CoV-2 spreads true scale pandemic. Here, to better understand two southern African countries, Mozambique...
Understanding the dynamics of infectious disease spread and predicting clinical outcomes are critical for managing large-scale epidemics pandemics, such as COVID-19. Effective modeling transmission in interconnected populations helps inform public health responses interventions across regions. We developed a novel metapopulation model simulating respiratory virus North America region, specifically 96 states, provinces, territories Canada, Mexico, United States. The is informed by COVID-19...
If $(d_{n})_{n\geq 0}$ is a martingale difference sequence, $(\varepsilon _{n})_{n\geq sequence of numbers in $\{ 1,-1\}$, and $n$ positive integer, then \[ P(\max _{0\leq m\leq n}\vert \sum _{k=0}^{m} \varepsilon _{k}d_{k}\vert \geq 1) \leq \alpha _{p}\Vert _{k=0}^{n} d_{k}\Vert _{p}^{p}. \] Here $\alpha _{p}$ denotes the best constant. $1\leq p\leq 2$, _{p}= 2/\Gamma (p+1)$ as was shown by Burkholder. We show here that _p=p^{p-1}/2$ for case $p > $p^{p-1}/2$ also constant analogous...
In South Korea, despite the implementation of a universal single-dose vaccination program for children aged 12–15 months in 2005, varicella incidence rate remains significant. Prior case-control studies have reported that currently used vaccines are extremely inefficacious. We estimated vaccine effectiveness (VE) by fitting dynamic transmission model to age-specific data from 2007 2015 and available coverage data. The initial efficacy primary failure rates were be 61.1% 38.9%, respectively....
Background Rapid diagnostic tests (RDTs) are widely used for diagnosing Plasmodium vivax malaria, especially in resource-limited countries. However, the impact of RDTs on P. malaria incidence and national medical costs has not been evaluated. We assessed RDT implementation overall expenditures South Korea performed a cost–benefit analysis from payer’s perspective. Methods developed dynamic compartmental model transmission using delay differential equations. Long latency seasonality were...
The 2019 emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its rapid spread created a public health emergency international concern. However, the impact pandemic in Sub-Saharan Africa, as documented cases, hospitalizations deaths, appears far lower than Americas, Europe, Asia. Characterization transmission dynamics is critical for understanding how SARS-CoV-2 true scale pandemic. Here, to better understand two southern African countries, Mozambique Zimbabwe, we...
In February 2018, the Ministry of Food and Drug Safety in Korea approved tenofovir disoproxil fumarate emtricitabine (TDF/FTC) co-formulate for use pre-exposure prophylaxis (PrEP) prevention human immunodeficiency virus (HIV) infection. This study aimed to estimate cost-effectiveness PrEP men who have sex with (MSM), a major risk group emerging Korea. A dynamic compartmental model was developed HIV transmission progression MSM aged 15-64 years. With combined including economic analysis, we...
Varicella, which is caused by the varicella zoster virus (VZV), a common infectious disease affecting children. Varicella vaccines have been used for decades; however, vaccination policies vary across countries because of differences in VZV epidemiology. The basic reproductive number R0 transmissibility measure parameter, also differs from country to country. In this study was estimated South Korea using contact rate matrix derived averaged POLYMOD data, Korean population, and...
Abstract Explaining spatiotemporal variability in metacommunities is challenging because conducting empirical studies that link mechanisms across scales difficult. We developed a stochastic model of epilithic algal succession streams to better understand the underlying interactions drive patch dynamics at three levels spatial hierarchy: patch, channel habitat, and reach. The state an specified by one nine community types, which are defined growth form. Ninety‐two data sets were used estimate...
Background: Plasmodium vivax malaria has a persistent liver stage that causes relapse, and introducing tafenoquine to suppress relapse could aid in disease eradication.Therefore, we assessed the impact of introduction on P. incidence performed cost-benefit analysis from payer's perspective.Methods: We expanded previously developed dynamic transmission model calibrated it weekly civilian incidences 2014-2018.Primaquine scenarios were considered by assuming different probabilities, total cases...
We consider a multivariate Langevin equation in discrete time, driven by force induced certain Gibbs’states. The main goal of the paper is to study asymptotic behavior random walk with stationary increments (which are interpreted as discrete-time speed terms) satisfying equation. observe that (stable) functional limit theorems and laws iterated logarithm for regular walks i.i.d. heavy-tailed can be carried over motion particle.
Abstract In early 2020, South Korea experienced a large coronavirus disease 2019 (COVID-19) outbreak. However, despite its proximity to China, where the virus had emerged, and high population density of Seoul metropolitan area, major international hub, effectively contained spread COVID-19 using non-pharmaceutical interventions until vaccine distribution in 2021. Here, we built metapopulation model with susceptible-exposed-infectious-quarantined-recovered (SEIQR) structure combined it...
Background Plasmodium vivax malaria has been one of the most troublesome diseases in Democratic People’s Republic Korea (DPRK). Given that a majority cases are concentrated near demilitarized zone, concerted elimination efforts from both (ROK) and DPRK essential for malaria-free Korean Peninsula. This study assessed impact rapid diagnostic tests (RDTs) tafenoquine on incidence DPRK. Methods We patterned current model structure previously developed dynamic transmission ROK. Model parameters...
Summary Background Metapopulation models provide platforms for understanding infectious disease dynamics and predicting clinical outcomes across interconnected populations, particularly large epidemics pandemics like COVID-19. Methods We developed a novel metapopulation model simulating respiratory virus transmission in the North America region, specifically 96 states, provinces, territories of Canada, Mexico United States. The is informed by COVID-19 case data, which are assimilated using...
For the enhancement of high temperature performance Mg-Zn based alloys, Sn element has been alloyed. However, effect on thermal conductivity alloys barely studied. In this study, pure Mg and Mg-5Zn are alloyed with a 1, 3, 5 mass% Sn, respectively, heat capacity, diffusivity then evaluated in range 298 to 573 K. Mg-Sn binary capacity gradually decrease increasing volume fraction Mg2Sn phase. Mg-Zn-Sn (ZT alloy), since adding is mostly located at MgZn2 phases, not affected an increment...
The 2-sample mark-recapture method with Chapman’s estimator is often used by inland fishery managers to estimate the reach-scale abundance of stream fish. An important assumption this that no dispersal into or out study reach occurs between two samples. Violations are probably common in practice, but their effect on bias (systematic error) estimates poorly understood, especially small populations. Estimation methods permitting exist but, for logistical reasons, infeasible routine assessments...
For $0< p <\infty$, put \[ Y_t(c,p)=Y= B_t^{*(p-2)} [ B_t^2 -t ]+c B_t^{*p},\quad t>0, \] where $B_t$ is a Brownian Motion and $B_t^*=\max_{0 \leq s t} |B_s|$. Then for 2$, $Y$ submartingale if only $c \geq \frac{2-p}{p}$, while $2 < \infty$, supermartingale $c\leq \frac{2-p}{p}$. This extends results of Burkholder. The first these assertions implies strong version some the Burkholder-Gundy inequalities.