Although HTN planning is in general undecidable, there are many syntactically identifiable sub-classes of HTN problems that can be decided. For these sub-classes, the decision procedures provide upper complexity bounds. Lower bounds were often not investigated in more detail, however. We generalize a propositional HTN formalization to one that is based upon a function-free first-order logic and...

Although task reduction (HTN) planning historically preceded partial order (PO) planning, and is understood to be more general than the latter, very little analysis has been done regarding its performance. Part of the reason for this has been the lack of systematic understanding of the functionalities provided by HTN planning over and above that of partial order planning. HTN planning has been ...

Causal reasoning under ambiguity requires subjects to estimate and evaluate ambiguous observations. This paper proposes a hierarchical model that accounts for the uncertainty of both the distribution of the functional form selection and distribution of the ambiguity treatment selection. The posterior distribution of the causal estimates is determined by both the functional form and the ambiguit...

In this research, a hierarchical location-allocation problem is modeled in a queue framework. The queue model is considered as M/M/1/k, in which system capacity is finite, equals to k. This is the main contribution of the current research. Customer's enters to the system in order to find the service according to a Poisson. In this problem, the hierarchical location-allocation model is considere...

An efficient technique for the analysis of scattering by uniaxial anisotropic objects is presented. The technique is based on the method of higher order MoM of the surface integral equations. This higher order MoM solution uses the higher order hierarchical basis functions which are based on the modified Legendre polynomials. Numerical results are given to demonstrate that the higher order hier...

The hierarchical reconstruction [11] is applied to discontinuous Galerkin method on the two-dimensional unstructured grids. We explore a variety of limiter functions used in the construction of piecewise linear polynomials. We show that due to the abrupt shift of stencils, the use of center biased limiter functions is essential in order to recover the desired order of accuracy. Furthermore, we ...