Guidance and control of aircraft in the landing phase imposes extra pilot work loads, hence application of automatic landing control systems is of great importance. In this study automatic landing control systems are introduced and an optimal landing control system is designed. The control system performance criteria are based on minimum control effort. The designed system is simulated for a tr...

Perturbative gravity in global de Sitter space is subject to so-called linearization stability constraints: If they are to couple consistently to the gravitational field, quantum states must be invariant under the de Sitter isometries. While standard Fock spaces contain no de Sitter-invariant states apart from (possibly) the vacuum, a full Hilbert space of de Sitter-invariant quantum states can...

We propose that the state represented by the Nariai black hole inside de Sitter space is the ground state of the de Sitter gravity, while the pure de Sitter space is the maximal energy state. With this point of view, we investigate thermodynamics of de Sitter space, we find that if there is a dual field theory, this theory can not be a CFT in a fixed dimension. Near the Nariai limit, we conject...

Quasinormal mode spectra for gravitational perturbations of black holes in four dimensional de Sitter and anti-de Sitter space are investigated. The de Sitter case lends itself to approximation by a Pöshl-Teller potential. The anti-de Sitter case is relevant to the ADS-CFT correspondence in superstring theory. The ADS-CFT correspondence suggests a prefered set of boundary conditions. Pacs numbe...

Purpose Unlike conventional aircraft, birds can glide without a vertical tail. The purpose of this paper is to analyse the influence dihedral angle spanwise distribution on lateral-directional dynamic stability by simulation, calculation in development bird-inspired aircraft and flight testing. Design/methodology/approach gliding magnificent frigatebird ( Fregata magnificens ) was selected as s...

We propose a novel prescription for computing the boundary stress tensor and charges of asymptotically de Sitter (dS) spacetimes from data at early or late time infinity. If there is a holographic dual to dS spaces, defined analogously to the AdS/CFT correspondence, our methods compute the (Euclidean) stress tensor of the dual. We compute the masses of Schwarzschild-de Sitter black holes in fou...

Three-dimensional warped anti-de Sitter space in topologically massive gravity with a negative cosmological constant has been proposed to be holographically dual to a two-dimensional conformal field theory. We extend this proposal to both positive and vanishing values of the cosmological constant where stretched warped anti-de Sitter space is found to be a solution. For positive cosmological co...

guidance and control of aircraft in the landing phase imposes extra pilot work loads, hence application of automatic landing control systems is of great importance. in this study automatic landing control systems are introduced and an optimal landing control system is designed. the control system performance criteria are based on minimum control effort. the designed system is simulated for a tr...