An initial-boundary value problem of subdiffusion type is considered; the temporal component differential operator has form $$\sum _{i=1}^{\ell }q_i(t)\, D _t ^{\alpha _i} u(x,t)$$ , where $$q_i$$ are continuous functions, each $$D _i}$$ a Caputo derivative, and $$\alpha _i$$ lie in (0, 1]. Maximum/comparison principles for this proved under weak hypotheses. A new positivity result multinomial ...

We consider a new type of value chain that includes both production and service capabilities for existing product lines and that incorporates new product and service development. In this paper we model this value chain using system dynamics. The essential variables and causal relationships, which are expressed as linear differential equations among these variables, are also presented. We discus...

Direct simulation Monte Carlo (DSMC) of shock interaction in hypersonic low density flow is developed. Three collision molecular models, including hard sphere (HS), variable hard sphere (VHS), and variable soft sphere (VSS), are employed in the DSMC study. The simulations of double-cone and Edney's type IV hypersonic shock interactions in low density flow are performed. Comparisons between DSMC...

This paper proposes a design method of separable denominator 2-D variable digital filters with high frequency tuning accuracy. In the proposed method, a parallel allpass structure with complex coefficients is used as a prototype structure of the 2-D variable digital filters. The proposed 2-D variable digital filters are composed of first-order complex allpass sections. To improve the frequency ...