Our work is in the area of automated verification of software properties in modern programing languages. We present three papers related to various aspects of our research field: a modular pointer and effect analysis for object oriented programs, a precise and efficient typestate analysis, and a precise, parametric array content analysis. We discuss their contributions as well as their shortcom...

Let K be a totally real number field with Galois closure L. We prove that if f ∈ Q[x1, . . . , xn] is a sum of m squares in K[x1, . . . , xn], then f is a sum of 4m · 2[L:Q]+1 ([L : Q] + 1 2 ) squares in Q[x1, . . . , xn]. Moreover, our argument is constructive and generalizes to the case of commutative K-algebras. This result gives a partial resolution to a question of Sturmfels on the algebra...

Recent studies in maritime shipping have concentrated on environmental and economic impacts of ships. In this regard, fuel is considered as one of the important factors for such impacts. In particular, the sailing speed of the vessels affects the fuel consumption directly. In this study, we consider a speed optimization problem in liner shipping, which is characterized by stochastic port times ...