We study the computational complexity of the N-representability problem in quantum chemistry. We show that this problem is quantum Merlin-Arthur complete, which is the quantum generalization of nondeterministic polynomial time complete. Our proof uses a simple mapping from spin systems to fermionic systems, as well as a convex optimization technique that reduces the problem of finding ground st...

Petroleum hydrocarbon contamination of ground water is a significant and often complex problem. The complexity results from the fact that ground-water contamination is a product of soil contamination. Especially with older spills, significant amounts of hydrocarbons can be trapped below the water table. Traditional pump and treat is ineffective because of the low solubility of trapped oily phas...

A logic program with function symbols is called finitely ground if there is a finite propositional logic program whose stable models are exactly the same as the stable models of this program. Finite groundability is an important property for logic programs with function symbols because it makes feasible to compute such program’s stable models using traditional ASP solvers. In this paper, we int...

earthquake ground-motions show significant variability in both spectral and temporal characteristics. procedures to generalize and predict strong ground motions may be generally divided into three main disciplines: numerical techniques based on a kinematic source description, empirical attenuation models, and semi-empirical stochastic models. numerous studies have shown that, in the near-fault ...

Following the establishment of point measurements of ground-level ozone concentrations have been attempts by many researchers to develop ozone surfaces. This paper offers a critique of ozone-mapping endeavors, while also empirically exploring the operational scale of ground-level ozone. The following issues are discussed: aspects of spatial scale; the spatial complexity of ground-level ozone co...

As society becomes more complex, complexity becomes part of our education. Education nowadays witnesses complex problem solving tasks and multidisciplinary teamwork. Although multidisciplinarity is a prerequisite for the knowledge construction imposed by these tasks, it is in no way a guarantee. Multidisciplinary teams need common ground to enable the knowledge construction needed for complex p...

A method is presented to estimate the accuracy of an automated classification system based only on expert ratings on test cases, where the system may be substantially more accurate than the raters. In this method an estimate of overall rater accuracy is derived from the level of inter-rater agreement, Bayesian updating based on estimated rater accuracy is applied to estimate a ground truth prob...

due to the particular importance of projects in human life and in organizations, proper project management has been always regarded highly by researchers and practitioners. recent advances in technology and fundamental changes in most scientific areas have affected projects and made their nature and environmental circumstances much more complex than in the past. fortunately, in recent years, ma...

We study the dynamics of public opinion in a model where agents change their opinions as a result of random binary encounters if the opinion difference is below their individual thresholds that evolve over time.We ground these thresholds in a simple individual cost-benefit analysis with linear benefits of diversity and quadratic communication costs. We clarify and deepen the results of earlier ...