An approach to market analysis for lighter than air transportation of freight

An approach is presented to marketing analysis for lighter than air vehicles in a commercial freight market. After a discussion of key characteristics of supply and demand factors, a three-phase approach to marketing analysis is described. The existing transportation systems are quantitatively defined and possible roles for lighter than air vehicles within this framework are postulated. The marketing analysis views the situation from the perspective of both the shipper and the carrier. A demand for freight service is assumed and the resulting supply characteristics are determined. Then, these supply characteristics are used to establish the demand for competing modes. The process is then iterated to arrive at the market solution

Stability of Noisy Metropolis-Hastings

Pseudo-marginal Markov chain Monte Carlo methods for sampling from intractable distributions have gained recent interest and have been theoretically studied in considerable depth. Their main appeal is that they are exact, in the sense that they target marginally the correct invariant distribution. However, the pseudo-marginal Markov chain can exhibit poor mixing and slow convergence towards its target. As an alternative, a subtly different Markov chain can be simulated, where better mixing is possible but the exactness property is sacrificed. This is the noisy algorithm, initially conceptualised as Monte Carlo within Metropolis (MCWM), which has also been studied but to a lesser extent. The present article provides a further characterisation of the noisy algorithm, with a focus on fundamental stability properties like positive recurrence and geometric ergodicity. Sufficient conditions for inheriting geometric ergodicity from a standard Metropolis-Hastings chain are given, as well as convergence of the invariant distribution towards the true target distribution

When All the World\u27s a Stage: The Impact of Events on News Coverage of South Africa, 1979-1985

A time series analysis was used to investigate: (1) whether a significant increase in news coverage of South Africa occurred during the critical years of 1979-1985 ; (2) whether the geographic origin and/or sociopolitical impact of events, rather than deaths per se, caused the increase; and (3) the manner in which the increase occurred. Results indicated that two symbolic events (i.e., a series of riots in twenty-one South African townships, internal to South Africa; and the awarding of the Nobel Prize to Bishop Desmond Tutu, external to South Africa) cumulatively were responsible for a significant rise in news coverage of South Africa. The relationship of these symbolic sociopolitical events to the forces that shape short-term news headlines and long-term social change in general, including the imminent demise of apartheid in particular is discussed

Overlap Dirac operator at nonzero chemical potential and random matrix theory

We show how to introduce a quark chemical potential in the overlap Dirac operator. The resulting operator satisfies a Ginsparg-Wilson relation and has exact zero modes. It is no longer gamma_5-hermitian, but its nonreal eigenvalues still occur in pairs. We compute the spectral density of the operator on the lattice and show that, for small eigenvalues, the data agree with analytical predictions of nonhermitian chiral random matrix theory for both trivial and nontrivial topology.Comment: 4 pages, 2 figure

A STUDY OF CRYOPUMP CONFIGURATIONS IN FREE MOLECULAR FLOW REGIONS

Monte carlo computer technique applied to focusing of cryopump configurations in free molecular flow regio

MEXIT: Maximal un-coupling times for stochastic processes

Classical coupling constructions arrange for copies of the \emph{same} Markov process started at two \emph{different} initial states to become equal as soon as possible. In this paper, we consider an alternative coupling framework in which one seeks to arrange for two \emph{different} Markov (or other stochastic) processes to remain equal for as long as possible, when started in the \emph{same} state. We refer to this "un-coupling" or "maximal agreement" construction as \emph{MEXIT}, standing for "maximal exit". After highlighting the importance of un-coupling arguments in a few key statistical and probabilistic settings, we develop an explicit \MEXIT construction for stochastic processes in discrete time with countable state-space. This construction is generalized to random processes on general state-space running in continuous time, and then exemplified by discussion of \MEXIT for Brownian motions with two different constant drifts.Comment: 28 page

Kinematic dynamo action in a sphere. I. Effects of differential rotation and meridional circulation on solutions with axial dipole symmetry

A sphere containing electrically conducting fluid can generate a magnetic field by dynamo action, provided the flow is sufficiently complicated and vigorous. The dynamo mechanism is thought to sustain magnetic fields in planets and stars. The kinematic dynamo problem tests steady flows for magnetic instability, but rather few dynamos have been found so far because of severe numerical difficulties. Dynamo action might, therefore, be quite unusual, at least for large-scale steady flows. We address this question by testing a two-parameter class of flows for dynamo generation of magnetic fields containing an axial dipole. The class of flows includes two completely different types of known dynamos, one dominated by differential rotation (D) and one with none. We find that 36% of the flows in seven distinct zones in parameter space act as dynamos, while the remaining 64% either fail to generate this type of magnetic field or generate fields that are too small in scale to be resolved by our numerical method. The two previously known dynamo types lie in the same zone, and it is therefore possible to change the flow continuously from one to the other without losing dynamo action. Differential rotation is found to promote large-scale axisymmetric toroidal magnetic fields, while meridional circulation (M) promotes large-scale axisymmetric poloidal fields concentrated at high latitudes near the axis. Magnetic fields resembling that of the Earth are generated by D > 0, corresponding to westward flow at the surface, and M of either sign but not zero. Very few oscillatory solutions are found

Genetic mapping, synteny, and physical location of two loci for Fusarium oxysporum f. sp. tracheiphilum race 4 resistance in cowpea [Vignaunguiculata (L.) Walp].

Fusarium wilt is a vascular disease caused by the fungus Fusariumoxysporum f.sp. tracheiphilum (Fot) in cowpea [Vignaunguiculata (L.) Walp]. In this study, we mapped loci conferring resistance to Fot race 4 in three cowpea RIL populations: IT93K-503-1 × CB46, CB27 × 24-125B-1, and CB27 × IT82E-18/Big Buff. Two independent loci which confer resistance to Fot race 4 were identified, Fot4-1 and Fot4-2. Fot4-1 was identified in the IT93K-503-1 (resistant) × CB46 (susceptible) population and was positioned on the cowpea consensus genetic map, spanning 21.57-29.40 cM on linkage group 5. The Fot4-2 locus was validated by identifying it in both the CB27 (resistant) × 24-125B-1 (susceptible) and CB27 (resistant) × IT82E-18/Big Buff (susceptible) populations. Fot4-2 was positioned on the cowpea consensus genetic map on linkage group 3; the minimum distance spanned 71.52-71.75 cM whereas the maximum distance spanned 64.44-80.23 cM. These genomic locations of Fot4-1 and Fot4-2 on the cowpea consensus genetic map, relative to Fot3-1 which was previously identified as the locus conferring resistance to Fot race 3, established that all three loci were independent. The Fot4-1 and Fot4-2 syntenic loci were examined in Glycine max, where several disease-resistance candidate genes were identified for both loci. In addition, Fot4-1 and Fot4-2 were coarsely positioned on the cowpea physical map. Fot4-1 and Fot4-2 will contribute to molecular marker development for future use in marker-assisted selection, thereby expediting introgression of Fot race 4 resistance into future cowpea cultivars

The Emmaus Road: A Cantata

Cantata based on the twenty-fourth chapter of Luke.https://digitalcommons.georgefox.edu/arthur_roberts/1003/thumbnail.jp