Static analyzers like Astrée are incomplete, hence, may produce false alarms. We propose a framework for the investigation of the alarms produced by Astrée, so as to help classifying them as true errors or false alarms that are due to the approximation inherent in the static analysis. Our approach is based on the computation of an approximation of a set of traces specified by an initial and a (...

Feasibility tests determine whether it is possible for a given real-time system to always meet all of its timing constraints on a specified processing platform. Current feasibility tests for the uniprocessor static-priority scheduling of sporadic task systems run in pseudo-polynomial time. We present a fully polynomial-time approximation scheme (FPTAS) for feasibility analysis in static-priorit...

%'e have applied the Schwinger multichannel formulation [K. Takatsuka and V. McKoy, Phys. Rev. A 24, 2473 (1981)]to the elastic scattering of low-energy (1—30-eV) electrons by silane. Our results, obtained within the fixed-nuclei, static-exchange approximation, are in generally good agreement with recent differential, integral, and momentum-transfer cross-section measurements between 5 and 30 e...

Jahn-Teller (JT) electron-phonon coupling effects in the colossal magnetoresistance perovskite compounds La1−xAxMnO3 are investigated. Electronelectron correlations between two degenerate Mn eg orbitals are studied in the Gutzwiller approximation. The static JT distortion and antiadiabatic polaron effects are studied in a modified Lang-Firsov approximation. We find that (i) the electron or hole...

This paper studies wavelength assignment algorithms on WDM all-optical trees of rings under different models: static, incremental and dynamic. It is shown that 5L/2 is the tight bound of the number of required wavelengths for static trees of rings with load L. This paper also proposes an O[log2(t+1)]-approximation and a  ∑ = ∈ h i R r r V i 1 | ) ( | log max   +h-approximation algorithm for ...

the present study is an attempt to investigate some features of radial basis functions (rbfs) approximation methods related to variational problems. thereby authors applied some properties of rbfs to develop a direct method which reduces constrained variational problem to a static optimization problem. to assess the applicability and effectiveness of the method, some examples are examined. dyna...

A new finite element method/boundary method (FEM/BEM) scheme is proposed for the solution of 2D magnetic static and quasi-static problems with unbounded domains. The novelty an original approach in treatment outer region. related domain integral eliminated at discrete level by using approximation fundamental solutions (Green’s functions) every node mesh. This “FEM-Green” replaces standard bound...

The tube wave, or low-frequency manifestation of the Stoneley wave, has been modeled previously using the quasi-static approximation; I extend this method to include the effect of the formation matrix compressibility, which tends to marginally increase the tube-wave attenuation. Using the Biot theory of poroelasticity, I develop a fully dynamic description of the Stoneley wave. The dispersion r...

Fuzzy control systems have been extensively used on industrial applications. In the recent years Fuzzy Modeling had become the center of attention for researchers in the area. The theory has been oriented mainly to static function approximation and classiication problems but very few publications have addressed the problem of dynamic function approximation. The problem of identiication using no...

A basic theory is presented for the photoexcitation of a core state of a Rydberg atom in any type of static field; in this situation, the core state is excited by the photon while the Rydberg electron is essentially a spectator. This simple picture is made interesting through the interaction of the Rydberg electron with the core which can cause a change in the Rydberg electron’s state and can c...