Yet Another Graph Partitioning Problem is NP-Hard

Recently a large number of graph separator problems have been proven to be \textsc{NP-Hard}. Amazingly we have found that $\alpha$-Subgraph-Balanced-Vertex-Separator, an important variant, has been overlooked. In this work ``Yet Another Graph Partitioning Problem is NP-Hard" we present the surprising result that $\alpha$-Subgraph-Balanced-Vertex-Separator is $NP$-Hard. This is despite the fact that the constraints of our new problem are harder to satisfy than the original problem

Tourism curriculum in the University Sector: Does it meet future requirements? Evidence from Australia

In the contemporary competitive and globally connected marketplace, factors that guaranteed business success in the past may be of limited relevance in the future. Within the paradigms of today’s business, many successful operators continually introduce new products and services to maintain their market leadership position. Whilst firms in the tourism industry seek to maintain competitive position through policy planning, strategic marketing, budgeting and R&D, tourism education providers occupy a key position by seeking to enhance the skill levels of management and employees, both present and future. This paper reviews some Australian tourism and hospitality education programmes and course curriculum and briefly compares them with some trends in other English-speaking countries. The research explores tourism industry demand, trainees’ expectations and additionally identifies gaps and opportunities for the future curriculum content. The findings may, therefore, assist tourism programme providers with a broader perspective with which to shape future tourism courses

Diffusion Approximations for Demographic Inference: DaDi

Models of demographic history (population sizes, migration rates, and divergence times) inferred from genetic data complement archeology and serve as null models in genome scans for selection. Most current inference methods are computationally limited to considering simple models or non-recombining data. We introduce a method based on a diffusion approximation to the joint frequency spectrum of genetic variation between populations. Our implementation, DaDi, can model up to three interacting populations and scales well to genome-wide data. We have applied DaDi to human data from Africa, Europe, and East Asia, building the most complex statistically well-characterized model of human migration out of Africa to date

Element-specific modal formulations for large-displacement multibody dynamics

Large dispacement assumed-mode modeling techniques are examined in the context of multibody elastodynamics. The range of both general and element-specific approaches are studied with the aid of examples involving beams, plates, and shells. For systems undergoing primarily structural bending and twisting with little or no membrane distortion, it is found that fully-linear, element-specific, modal formulations provide the most accurate time history solutions at the least expense. When membrane effects become dominant in structural problems due to loading and boundary conditions, one must naturally resort to a formulation involving a nonlinear stress-strain relationship in addition to nonlinear terms associated with large overall system motion. Such nonlinear models were investigated using assumed modes and found to lead to modal convergence difficulties when standard free-free structural modes are employed. A constrained mode formulation aimed at addressing the convergence problem is proposed