64 citations · 111 across the 26 of their papers we have counts for
37 papers
Population size in stochastic multi-patch ecological models
Alexandru Hening, Siddharth Sabharwal
We look at the interaction of dispersal and environmental stochasticity in -patch models. We are able to prove persistence and extinction results even in the setting when the di…
Dynamics of stochastic microorganism flocculation models
Alexandru Hening, Nguyen T. Hieu, Dang H. Nguyen +1
In this paper we study the dynamics of stochastic microorganism flocculation models. Given the strong influence of environmental and seasonal fluctuations that are present in these…
Population dynamics under random switching
Alexandru Hening, Siddharth Sabharwal
Populations interact non-linearly and are influenced by environmental fluctuations. In order to have realistic mathematical models, one needs to take into account that the environm…
Population size in stochastic discrete-time ecological dynamics
Alexandru Hening, Siddharth Sabharwal
We study how environmental stochasticity influences the long-term population size in certain one- and two-species models. The difficulty is that even when one can prove that there…
Long-term behavior of stochastic SIQRS epidemic models
Alexandru Hening, Dang H. Nguyen, Tran Ta +1
In this paper we analyze and classify the dynamics of SIQRS epidemiological models with susceptible, infected, quarantined, and recovered classes, where the recovered individuals c…
Stability and Fluctuations in Complex Ecological Systems
Eric Forgoston, Sarah Day, Peter C. de Ruiter +24
From 08-12 August, 2022, 32 individuals participated in a workshop, Stability and Fluctuations in Complex Ecological Systems, at the Lorentz Center, located in Leiden, The Netherla…
Stochastic nutrient-plankton models
Alexandru Hening, Nguyen Trong Hieu, Dang Hai Nguyen +1
We analyze plankton-nutrient food chain models composed of phytoplankton, herbivorous zooplankton and a limiting nutrient. These models have played a key role in understanding the…
Population dynamics under demographic and environmental stochasticity
Alexandru Hening, Weiwei Qi, Zhongwei Shen +1
The present paper is devoted to the study of the long term dynamics of diffusion processes modelling a single species that experiences both demographic and environmental stochastic…
Stochastic epidemic SIR models with hidden states
Nguyen Du, Alexandru Hening, Nhu Nguyen +1
This paper focuses on and analyzes realistic SIR models that take stochasticity into account. The proposed systems are applicable to most incidence rates that are used in the liter…
Random switching in an ecosystem with two prey and one predator
Alexandru Hening, Dang Nguyen, Nhu Nguyen +1
In this paper we study the long term dynamics of two prey species and one predator species. In the deterministic setting, if we assume the interactions are of Lotka-Volterra type (…
The effects of random and seasonal environmental fluctuations on optimal harvesting and stocking
Alexandru Hening, Ky Q. Tran, Sergiu C. Ungureanu
We analyze the harvesting and stocking of a population that is affected by random and seasonal environmental fluctuations. The main novelty comes from having three layers of enviro…
Optimal ergodic harvesting under ambiguity
Asaf Cohen, Alexandru Hening, Chuhao Sun
We consider an ergodic harvesting problem with model ambiguity that arises from biology. To account for the ambiguity, the problem is constructed as a stochastic game with two play…
Quasi-stationary distributions of multi-dimensional diffusion processes
Alexandru Hening, Weiwei Qi, Zhongwei Shen +1
The present paper is devoted to the investigation of the long term behavior of a class of singular multi-dimensional diffusion processes that get absorbed in finite time with proba…
A general theory of coexistence and extinction for stochastic ecological communities
Alexandru Hening, Dang H. Nguyen, Peter Chesson
We analyze a general theory for coexistence and extinction of ecological communities that are influenced by stochastic temporal environmental fluctuations. The results apply to dis…
A classification of the dynamics of three-dimensional stochastic ecological systems
Alexandru Hening, Dang H. Nguyen, Sebastian J. Schreiber
The classification of the long-term behavior of dynamical systems is a fundamental problem in mathematics. For both deterministic and stochastic dynamics specific classes of models…
Stationary distributions of persistent ecological systems
Alexandru Hening, Yao Li
We analyze ecological systems that are influenced by random environmental fluctuations. We first provide general conditions which ensure that the species coexist and the system con…
Coexistence, extinction, and optimal harvesting in discrete-time stochastic population models
Alexandru Hening
We analyze the long term behavior of interacting populations which can be controlled through harvesting. The dynamics is assumed to be discrete in time and stochastic due to the ef…
Harvesting and seeding of stochastic populations: analysis and numerical approximation
Alexandru Hening, Ky Tran
It is well known that excessive harvesting or hunting has driven species to extinction both on local and global scales. This leads to one of the fundamental problems of conservatio…
Dynamical systems with fast switching and slow diffusion: Hyperbolic equilibria and stable limit cycles
Nguyen H. Du, Alexandru Hening, Dang H. Nguyen +1
We study the long-term qualitative behavior of randomly perturbed dynamical systems. More specifically, we look at limit cycles of stochastic differential equations (SDE) with Mark…
Harvesting of interacting stochastic populations
Alexandru Hening, Ky Quan Tran, Tien Trong Phan +1
We analyze the optimal harvesting problem for an ecosystem of species that experience environmental stochasticity. Our work generalizes the current literature significantly by taki…
The competitive exclusion principle in stochastic environments
Alexandru Hening, Dang H. Nguyen
In its simplest form, the competitive exclusion principle states that a number of species competing for a smaller number of resources cannot coexist. However, it has been observed…
Optimal sustainable harvesting of populations in random environments
Luis H. R. Alvarez E., Alexandru Hening
We study the optimal sustainable harvesting of a population that lives in a random environment. The novelty of our setting is that we maximize the asymptotic harvesting yield, both…
The Inverse First Passage Time Problem for killed Brownian motion
Boris Ettinger, Alexandru Hening, Tak Kwong Wong
The classical inverse first passage time problem asks whether, for a Brownian motion and a positive random variable , there exists a barrier $b:\mathbb{R}_+\to…
Asymptotic harvesting of populations in random environments
Alexandru Hening, Dang H. Nguyen, Sergiu C. Ungureanu +1
We consider the harvesting of a population in a stochastic environment whose dynamics in the absence of harvesting is described by a one dimensional diffusion. Using ergodic optima…