Yuanji Cheng

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On infinitesimally short time intervals various processes contributing to population change tend to operate independently so that we can simply add their contributions (Metz and Diekmann, The dynamics of physiologically structured populations, 1986, p. 3). This is one of the cornerstones for differential equations modeling in general. Complicated models for(More)
The Rosenzweig-MacArthur (1963) criterion is a graphical criterion that has been widely used for elucidating the local stability properties of the Gause (1934) type predator-prey systems. It has not been stated whether a similar criterion holds for models with explicit resource dynamics (Kooi et al. (1998)), like the chemostat model. In this paper we use(More)
In this paper we present a model for describing the position distribution of the endocardium in the two-chamber apical long-axis view of the heart in clinical B-mode ultrasound cycles. We propose a novel Bayesian formulation, including priors for spatial and temporal smoothness, and preferred shapes and position. The shape model takes into account both(More)
In this paper we study the generalized Fucik type eigenvalue for the boundary value problem of one dimensional p−Laplace type differential equations −(ϕ(u)) = ψ(u), −T < x < T ; u(−T) = 0, u(T) = 0 (*) where ϕ(s) = αs p−1 + − βs p−1 − , ψ(s) = λs p−1 + − µs p−1 − , p > 1. We obtain a explicit characterization of Fucik spectrum (α, β, λ, µ), i.e., for which(More)
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