An elementary proof of a basic uncertainty principle concerning pairs of representations of ℜ N vectors in different orthonormal bases is provided. The result, slightly stronger than stated before, has a direct impact on the uniqueness property of the sparse representation of such vectors using

Variable selection plays an important role in high dimensional statistical modeling which nowa-days appears in many areas and is key to various scientific discoveries. For problems of large scale or dimensionality p, estimation accuracy and computational cost are two top concerns. In a recent paper

principle, and as a proof principle for such structures. But there are also important dual "coalgebraic" structures, which do not come equipped with constructor operations but with what are sometimes called "destructor" operations (also called observers, accessors, transition maps

to particular programs of the family by the end-user through parametrization. This is applied to the proof of soundness of data manipulation operations at the machine level for periodic synchronous safety critical embedded software. The main novelties are the design principle of static analyzers by refinement

of faults that can be tolerated is examined. The proofs expose general heuristic principles that explain why consensus is possible in certain models but not possible in others.

This paper describes an application of Pipe Transportation Simulator (PTS) in oil refinery supply chain modelling. We develop the simulator in Witness simulation software environment using MS Excel for input data loading and outputs upgrading. PTS is particularly suitable for “what-if ” analysis in the crude oil, fuels or gas supply chains where the products are transported among warehouses and refineries through the pipe lines. To discuss the basic functionality of proposed simulator we employ PTS to simulate a real oil refinery supply chain consisting of 16 warehouses and 3 refineries placed in the Czech Republic and Slovakia. The refineries and warehouses are connected together with 21 pipe lines. PTS is used to verify a plan of fuels movements among warehouses and refineries as well as a plan of repairs of certain pipe lines in the selected time period of the length of 30 days.

This paper presents a new password authentication and key-exchange protocol suitable for authenticating users and exchanging keys over an untrusted network. The new protocol resists dictionary attacks mounted by either passive or active network intruders, allowing, in principle, even weak

dimensions under weak requirements on the switching and failing communication topology. The correctness proof relies on proximity graphs and their properties and on a LaSalle Invariance Principle for nondeterministic discrete-time systems.

. Rev. Lett. 78, 5022 (1997)] conjectured an explicit formula for the entanglement of formation of a pair of binary quantum objects (qubits) as a function of their density matrix, and proved the formula to be true for a special class of mixed states. The present paper extends the proof to arbitrary

are interpreted in an intuitionistic metatheory then the induced modal logics no longer satisfy certain intuitionistically invalid principles. This thesis investigates the intuitionistic modal logics that arise in this way. Natural deduction systems for various intuitionistic modal logics are presented. From one