Plans to pursue space expeditionary missions beyond Earth orbit have occasioned renewed concern that crew behavioral health and performance effectiveness, along with spacecraft habitability, will present major challenges to the success of spaceflight initiatives involving unprecedented increases in time and distance on interplanetary voyages. A programmed environment methodological approach tha...

In this chapter we show how algebraic geometry can be used to define and then analyse the properties of certain important classes of discrete probability models described through probability trees. Our aim is to show how much wider classes of discrete statistical models than have been considered previously have a useful algebraic formulation and unlike its competitors this class is closed under...

A new statistical confidence measure, Context ConstrainedGeneralized Posterior probability (CC-GPP), is proposed for verifying phone transcriptions in speech databases. Different from generalized posterior probability (GPP), CC-GPP is computed by considering string hypotheses that bear a focused phone with partially matched left and right contexts. Parameters used for CC-GPP include context win...

Two open questions of inductive reasoning are solved: (1) does the principle of maximum entropy (PME) give a solution to the obverse Majerník problem; and (2) is Wagner correct when he claims that Jeffrey’s updating principle (JUP) contradicts PME? Majerník shows that PME provides unique and plausible marginal probabilities, given conditional probabilities. The obverse problem posed here is whe...

Differential drag is a technique for altering the semimajor axis, velocity, and alongtrack position of a spacecraft in low Earth orbit. It involves varying the spacecraft’s cross-sectional area relative to its velocity direction by temporarily changing attitude and solar array angles, thus varying the amount of atmospheric drag on the spacecraft. The technique has recently been proposed and use...

This paper presents the complete analytical solution of several fundamental problems in orbital correction. The initial orbit is represented by a given point in the phase space, while the final orbit is constrained to stay in a given curve which can be bounded, unbounded, or composed of a finite number of segments of different curves. The inclusion of atmospheric maneuver as part of the optimum...

We study how the number c(X) of components of a graph X can be expressed through the number and properties of the components of a quotient graph X/∼ . We partially rely on classic qualifications of graph homomorphisms such as locally constrained homomorphisms and on the concept of equitable partition and orbit partition. We introduce the new definitions of pseudo-covering homomorphism and of co...

By phenomenologically assuming a slow temporal variation of the percent acceleration rate S̈S−1 of the cosmic scale factor S(t), it is shown that the orbit of a local binary undergoes a secular expansion. To first order in the power expansion of S̈S−1 around the present epoch t0, a non-vanishing shift per orbit ⟨∆r⟩ of the two-body relative distance r occurs for eccentric trajectories. A general ...

An analytical framework for the efficient evaluation of the performance of complete sharing (CS) and complete partitioning (CP) resource sharing policies under a newly proposed general channel management strategy for multi-class traffic in Low Earth Orbit-Mobile Satellite Systems (LEO-MSS) is presented. This strategy gives a higher priority to handover calls over new calls by combine the guard ...

AbstmctThe geographical connection admission control (GCAC) algorithm is introduced for low earth orbit LEO) satellite networks. The GCAC scheme estimates the L u r e handover blocking probability of a new call attempt based on the user location database, in order to decrease the handover blocking. By simulation, it is shown that the proposed GCAC scheme guarantees the handover blocking probabi...