We consider the time optimal control problem, with a point target, for a class of infinite dimensional systems with a dynamics governed by an abstract Schrödinger type equation. The main results establish a Pontryagyn type maximum principle and give sufficient conditions for the bangbang property of optimal controls. The results are then applied to some systems governed by partial differential ...

A summability theorem of Landau, which classically is a simple consequence of the uniform boundedness theorem, is examined within Bishop-style constructive mathematics. It is shown that the original theorem is nonconstructive, and that a natural weakening of the theorem is constructively equivalent to Ishihara’s principle BD-N. The paper ends with a number of results that, while not as strong a...

A complete solution is obtained for nonaxisymmetric resonant vibrations of a free cylinder or disk involving infinite sums. For axisymmetric longitudinal vibrations an alternative to previous solutions is included. In principle, the solutions satisfy exactly the stress-free boundary conditions, in contrast to the approximate bending-mode solutions due to Pickett or approximate solutions based o...

This paper sets out to clarify the complex issues of risk perception and management in connection with biotechnology and Third World development. It summarises the main threats and promises associated with the technology before explaining why traditional approaches to risk are flawed from both a scientific and an ethical standpoint. It ends by making suggestions about how the precautionary prin...

The fast transformation of technologies into new products or processes is one of the core challenges for any technology-based enterprise. Within the innovation process, we believe, the early phases (“fuzzy front end”) to have the highest impact on the whole process and the result (Input-Output Process), since it will influence the design and total costs of the innovation extremely. However the ...

applying two definitions of the union of if-events, p. grzegorzewski gave two generalizations of the inclusion-exclusion principle for if-events.in this paper we prove an inclusion-exclusion principle for if-states based on a method which can also be used to prove grzegorzewski's inclusion-exclusion principle for probabilities on if-events.finally, we give some applications of this principle by...

This paper sets out to clarify the complex issues of risk perception and management in connection with biotechnology and Third World development. It summarises the main threats and promises associated with the technology before explaining why traditional approaches to risk are flawed from both a scientific and an ethical standpoint. It ends by making suggestions about how the precautionary prin...

We review the progress in the field of front propagation in recent years. We survey many physical, biophysical and crossdisciplinary applications, including reduced-variable models of combustion flames, Reid’s paradox of rapid forest range expansions, the European colonization of North America during the XIX century, the Neolithic transition in Europe from 13,000 to 5,000 years before present, ...

occurred recency principle and recency proving   saber khalilnejad kiasari [1]   abstract: this article is to investigate one of the practical principles of methodology and jurisprudence as well as occurred recency principle. this principle is at work to clarify many issues concerned with the priority and recency of two carrying judicial and legal effects. here, through explaining the purpose o...