Fault-tolerant software for the FIMP

The work reported here provides protection against software failures in the task dispatcher of the FTMP, a particularly critical portion of the system software. Faults in other system modules and application programs can be handled by similar techniques but are not covered in this effort. Goals of the work reported here are: (1) to develop provisions in the software design that will detect and mitigate software failures in the dispatcher portion of the FTMP Executive and, (2) to propose the implementation of specific software reliability measures in other parts of the system. Beyond the specific support to the FTMP project, the work reported here represents a considerable advance in the practical application of the recovery block methodology for fault tolerant software design

Fault tolerant software modules for SIFT

The implementation of software fault tolerance is investigated for critical modules of the Software Implemented Fault Tolerance (SIFT) operating system to support the computational and reliability requirements of advanced fly by wire transport aircraft. Fault tolerant designs generated for the error reported and global executive are examined. A description of the alternate routines, implementation requirements, and software validation are included

Isomorphic chain complexes of Hamiltonian dynamics on tori

In this work we construct for a given smooth, generic Hamiltonian $H : \mathbb{S}^1\times\mathbb{T}^n \longrightarrow \mathbb{R}$ on the torus a chain isomorphism $\Phi_* : \big(C_*(H),\partial^M_*\big) \longrightarrow \big(C_*(H),\partial^F_*\big)$ between the Morse complex of the Hamiltonian action $A_H$ on the free loop space of the torus $\Lambda_0(\mathbb{T}^n)$ and the Floer complex. Though both complexes are generated by the critical points of $A_H$, their boundary operators differ. Therefore the construction of $\Phi$ is based on counting the moduli spaces of hybrid type solutions which involves stating a new non-Lagrangian boundary value problem for Cauchy-Riemann type operators not yet studied in Floer theory

Towards general purpose LES model of injection and atomization

Conferencia plenaria por invitaciónInjection and atomization of liquid is widely used in many industrial and domestic applications such as, fuel injection in engines or burners, spray painting, medical sprays, spray drying, etc. Various approaches are used to simulate two-phase flows. Usually, interface tracking methods are used to simulate the primary atomization while a dispersed method such as the Lagrangian particle-tracking approach may be used to model the final spray. Despite progresses in numerical methods and computer performance, complete simulation of atomization and spray remains inaccessible for many applications. A possibility consists to extend the ELSA approach to the well-established LES framework combined with an interface density equation for subgrid scales. A postulated transport equation of the interface density is used to describe the subgrid spray formation ranging from interface wrinkling, ligaments, and sheets up to the droplets. The objective of our work is to extend the LES ELSA method developed by Chesnel et al. into a general purpose solver OpenFOAM . The method has been adapted for unstructured mesh to address applications. The interface capturing method is based on the transport of a liquid volume fraction, αl. To sustain the sharp gradient of αl an additional compressive term is added to the equation. LES formulation induced a subgrid term SGSαl that is not compatible with numerical procedure used to capture the interface. The advantage of the compressive method is the possibility to switch it off when SGSαl become important, i.e. when the interface fluctuations become important at subgrid scale. In order to improve ELSA method a coupling with Lagrangian particle will be initialized. Lagrangian particle are create when liquid structure become droplet. The diameter and the number of particle are determined via the liquid volume fraction and via the interface density. The Eulerian equations have to be linked to the Lagrangian phase, this is achieved through the liquid turbulent diffusion flux closure. The aim of my work is to study the LES atomization method and make comparison of the liquid dispersion around the axes with a reference DNS.Universidad de Málaga. Campus de Excelencia Internacional Andalucia Tech. Conferencias del plan propio de la UM

Exact Localisations of Feedback Sets

The feedback arc (vertex) set problem, shortened FASP (FVSP), is to transform a given multi digraph $G=(V,E)$ into an acyclic graph by deleting as few arcs (vertices) as possible. Due to the results of Richard M. Karp in 1972 it is one of the classic NP-complete problems. An important contribution of this paper is that the subgraphs $G_{\mathrm{el}}(e)$, $G_{\mathrm{si}}(e)$ of all elementary cycles or simple cycles running through some arc $e \in E$, can be computed in $\mathcal{O}\big(|E|^2\big)$ and $\mathcal{O}(|E|^4)$, respectively. We use this fact and introduce the notion of the essential minor and isolated cycles, which yield a priori problem size reductions and in the special case of so called resolvable graphs an exact solution in $\mathcal{O}(|V||E|^3)$. We show that weighted versions of the FASP and FVSP possess a Bellman decomposition, which yields exact solutions using a dynamic programming technique in times $\mathcal{O}\big(2^{m}|E|^4\log(|V|)\big)$ and $\mathcal{O}\big(2^{n}\Delta(G)^4|V|^4\log(|E|)\big)$, where $m \leq |E|-|V| +1$, $n \leq (\Delta(G)-1)|V|-|E| +1$, respectively. The parameters $m,n$ can be computed in $\mathcal{O}(|E|^3)$, $\mathcal{O}(\Delta(G)^3|V|^3)$, respectively and denote the maximal dimension of the cycle space of all appearing meta graphs, decoding the intersection behavior of the cycles. Consequently, $m,n$ equal zero if all meta graphs are trees. Moreover, we deliver several heuristics and discuss how to control their variation from the optimum. Summarizing, the presented results allow us to suggest a strategy for an implementation of a fast and accurate FASP/FVSP-SOLVER

Investigations of chlorophyll interactions in Water Soluble Chlorophyll Binding Protein

Line narrowing spectroscopy was applied to water soluble chlorophyll binding protein (WSCP) containing only 2 chlorophylls. It was compared to natural occurring 4 chlorophyll WSCP. No significant difference were found