A linear model of atmospheric circulation

Linear model of atmospheric circulation used for atmosphere of Venu

Computation of three-dimensional supersonic flows with shock waves

Computation of three dimensional supersonic flows with shock wave

A direct method for calculation of the flow about an axisymmetric blunt body at angle of attack

Direct calculation method for supersonic inviscid flow around axisymmetric blunt body with conically reentrant afterbody flying at large angle of attac

Supersonic flow over convex and concave shapes with radiation and ablation effects

Numerical method of unsteady adjustment for calculating inviscid flow fields about convex and concave shapes on atmospheric entry with ablatio

A method for determining catalytic efficiency of surfaces

Catalytic efficiency calculations for surface heat flux and heat transfer during atmospheric reentr

General circulation in the atmosphere of Venus driven by polar and diurnal variations of surface temperature

Mathematical model for Venus atmosphere circulation pattern determined by polar and diurnal temperature variation

Development of an autonomous design program

Presented is a general approach to the development of an ''intelligent'' computer program that designs technical devices and systematically improves its capability without human intervention. The methodology is based on the recognition that effective use of computers requires employment of clearly defined concepts and precise language, therefore, significant effort is devoted to the formulation of the design problem in mathematical terms. This formulation is based on the introduction of metrizable performance and configuration spaces and on the representation of the design process as a mapping from the performance into the configuration space; the inverse of this mapping represents the design evaluation. An essential part of the design mapping, as we define it, is design optimization. For that purpose we developed a generalized simulated annealing method capable of locating global extrema of multidimensional functions that have numerous local extreme and may not be differentiable. The optimization method is interesting in its own right, for its applicability transcends the original intent. The exploitation of the concept of the design mapping and the optimization algorithm are illustrated with an application to the design of optical lenses. This application was chosen because it offers the possibility to evaluate each design solely by computation and thus validate the program's capability without the need for a physical realization

A simulated annealing methodology for clusterwise linear regression

In many regression applications, users are often faced with difficulties due to nonlinear relationships, heterogeneous subjects, or time series which are best represented by splines. In such applications, two or more regression functions are often necessary to best summarize the underlying structure of the data. Unfortunately, in most cases, it is not known a priori which subset of observations should be approximated with which specific regression function. This paper presents a methodology which simultaneously clusters observations into a preset number of groups and estimates the corresponding regression functions' coefficients, all to optimize a common objective function. We describe the problem and discuss related procedures. A new simulated annealing-based methodology is described as well as program options to accommodate overlapping or nonoverlapping clustering, replications per subject, univariate or multivariate dependent variables, and constraints imposed on cluster membership. Extensive Monte Carlo analyses are reported which investigate the overall performance of the methodology. A consumer psychology application is provided concerning a conjoint analysis investigation of consumer satisfaction determinants. Finally, other applications and extensions of the methodology are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45745/1/11336_2005_Article_BF02296405.pd

Pulsed hydrojet propulsion

The pulsed hydrojet is a device in which the water ingested from the free stream is accelerated out of the exhaust pipe to produce thrust. In this report we describe and analyze a way of accelerating the stream of water with pockets of high pressure steam and gas generated inside the stream by an exothermal reaction of suitable propellant injected and dispersed in the water. The velocity increment that must be imparted to the water to produce a substantial thrust need not be very large because the density of the water is comparable to the average density of the accelerated body. Results of the numerical modeling of the proposed jet acceleration mechanism indicate that the hydrojet propulsion device is potentially capable of propelling underwater projectiles at speeds three to five times greater than those currently attainable. Several promising applications of the hydrojet thruster are discussed and evaluated