Airworthiness considerations

Guidance is provided for the airworthiness approval of both annunciation only and annunciation with guidance airborne windshear warning systems. Characteristics of a comprehensive certification plan, the criticality of certain system failure cases for windshear warning with and without escape guidance, software based systems, and probability analysis are among the topics covered

Approaching the Ground State of a Quantum Spin Glass using a Zero-Temperature Quantum Monte Carlo

Here we discuss the annealing behavior of an infinite-range $\pm J$ Ising spin glass in presence of a transverse field using a zero-temperature quantum Monte Carlo. Within the simulation scheme, we demonstrate that quantum annealing not only helps finding the ground state of a classical spin glass, but can also help simulating the ground state of a quantum spin glass, in particularly, when the transverse field is low, much more efficiently.Comment: 8 pages, 6 fig

The April revolution and the contribution of education to changing 'Portuguese realities'

The subject of this thesis is educational mobilization in Portugal during the decade of the seventies. Rather than present an exhaustive account of the educational events that took place during the decade, the thesis attempts, firstly, to disentangle the complex web of occurrences in the field of education, and,secondly, ·to present an interpretation of three major educational events and their relationship to the changing nature of the Portuguese state.Inevitably the crowning event of the decade of the seventies,the April revolution of 1974, comes under considerable scrutiny. This brought to an end the Salazarist regime, which was incapable of coming to terms with the, eventually overwhelming, problem of decolonization. It also marked the beginning of a serious attempt to extend and deepen the effects of the (1971-3) Veiga Sima reform in education, which, in acting as a pivot for debates on the development and modernization of the country, found itself mediating the demands for chance emerging from civil society. This is described in Chapter 2.Chapters 3 and 4 describe how the April revolution stimulated very far reaching processes of democratization in education, both within the realm of relations of management within the school and in terms of what actually counted as education (that is, its redefinition in the light of the 'rediscovery' of 'Portuguese realities'). The fading of the project that was 'Portugal in transition to socialism', embodied in the process of 'normalization' which characterized the latter years of the decade of the seventies, is approached and assessed, in Chapter 5, through a study of the intervention of the World Bank in Portuguese higher education

Central Path Dynamics and a Model of Competition, II

Growth -- the change in number or size -- and adaptation -- the change in quality or structure -- are key attributes of global processes in natural communities, society and economics (see, e.g. Hofbauer and Sigmund, 1988; Freedman, 1991; Young, 1993). In this paper we describe a model with explicit growth-adaptation feedbacks. We treat it in the form of an economic model of competition of two firms (with several departments) on the market. Their size is measured by their capital, and their quality by their productive power (production complexity). It is assumed that the production complexity of a department or firm is a simple function (that is more general than the one considered in Krazhimskii and Stoer, 1999) of its capital. The model works on both the firm level (competition among the departments) and the market level (competition among the firms). The model shows some empirically observable phenomena. Typically, one of the firms will finally cover the market. The winner is not necessarily the firm with the potentially higher maximum productivity. A long-term coexistence of firms may arise in exceptional situations occurring only when the maximum potential productivities (not the actual productivities) are equal. The analysis is also based on the concept of central paths from the interior point optimization theory (see Sonnevend, 1985; and e.g., Ye, 1997)

A simple min cut algorithm

We present an algorithm for finding the minimum cut of an edge-weighted graph. It is simple in every respect. It has a short and compact description, is easy to implement and has a surprisingly simple proof of correctness. Its runtime matches that of the fastest algorithm known. The runtime analysis is straightforward. In contrast to nearly all approaches so far, the algorithm uses no flow techniques. Roughly spoken the algorithm consists of about |V| nearly identical phases each of which is formally similar to Prim's minimum spanning tree algorithm

Non-iterative and exact method for constraining particles in a linear geometry

We present a practical numerical method for evaluating the Lagrange multipliers necessary for maintaining a constrained linear geometry of particles in dynamical simulations. The method involves no iterations, and is limited in accuracy only by the numerical methods for solving small systems of linear equations. As a result of the non-iterative and exact (within numerical accuracy) nature of the procedure there is no drift in the constrained geometry, and the method is therefore readily applied to molecular dynamics simulations of, e.g., rigid linear molecules or materials of non-spherical grains. We illustrate the approach through implementation in the commonly used second-order velocity explicit Verlet method.Comment: 12 pages, 2 figure

Thermoconvection in magnetized ferrofluids: the influence of boundaries with finite heat conductivity

Realistic boundaries of finite heat conductivity Realistic boundaries of finite heat conductivity for thermoconvection in a Rayleigh-B\'enard setup with magnetized ferrofluids are investigated. A linear stability analysis of the conductive state is performed with a shooting method. It shows that the critical wave number is for any magnetic field stronly influenced by the conductivity of the boundaries. Linear as well as nonlinear coefficients of a Ginzburg Landau amplitude equation for convection shortly above the onset are evaluated as functions of the magnetic Rayleigh number, the boundary conductivities, and the fluid Prandtl number.Comment: 10 pages, 9figure

Exact Diagonalization Dynamical Mean Field Theory for Multi-Band Materials: Effect of Coulomb correlations on the Fermi surface of Na_0.3CoO_2

Dynamical mean field theory combined with finite-temperature exact diagonalization is shown to be a suitable method to study local Coulomb correlations in realistic multi-band materials. By making use of the sparseness of the impurity Hamiltonian, exact eigenstates can be evaluated for significantly larger clusters than in schemes based on full diagonalization. Since finite-size effects are greatly reduced this approach allows the study of three-band systems down to very low temperatures, for strong local Coulomb interactions and full Hund exchange. It is also shown that exact diagonalization yields smooth subband quasi-particle spectra and self-energies at real frequencies. As a first application the correlation induced charge transfer between t2g bands in Na_0.3CoO_2 is investigated. For both Hund and Ising exchange the small eg' Fermi surface hole pockets are found to be slightly enlarged compared to the non-interacting limit, in agreement with previous Quantum Monte Carlo dynamical mean field calculations for Ising exchange, but in conflict with photoemission data.Comment: 9 pages, 7 figure