Research Relating to Long-Range Supersonic Cruising Aircraft

1968 ◽  
Vol 72 (690) ◽  
pp. 481-489
Author(s):  
Laurence K. Loftin
Keyword(s):  
Control Systems ◽  
Linear Theory ◽  
Traffic Control ◽  
Research Programme ◽  
Aircraft Design ◽  
Wind Tunnels ◽  
Simulation Methods ◽  
Supersonic Aircraft ◽  
Langley Research Center ◽  
The Relationship

The NASA Langley Research Center has conducted an intensive and broad research programme on supersonic cruising aircraft for some 10 to 12 years. During the course of this effort to advance the state of technology of supersonic flight, a number of interesting research or design techniques and approaches have evolved. Several of these which have application to present and future aircraft design are discussed. The use of highspeed computing equipment in the application of linear theory to the problems of optimising supersonic cruising efficiency is treated. Experimental techniques employed in the study of drag at transonic speeds in wind tunnels are described. In the area of aircraft operations, attention is directed toward unique simulation methods employed in studying the relationship between air traffic control systems and supersonic aircraft.

QUANTIFICATION OF TUNA FISH TARGET STRENGTH USING QUANTITATIVE ECHO SOUNDER

2009 ◽  
Vol 1 (1) ◽  
Author(s):  
Henry M. Manik
Keyword(s):  
Wave Reflection ◽  
Fork Length ◽  
Research Programme ◽  
Yellowfin Tuna ◽  
Target Strength ◽  
Bigeye Tuna ◽  
Tuna Fish ◽  
Thunnus Obesus ◽  
The Relationship ◽  
Echo Sounder

A preliminary research programme was carried out in order to study the acoustic wave reflection or target strength (TS) of tuna fish using a quantitative echo sounder (QES). The relationships between TS to fork length (FL) and swimbladder volume, for bigeye tuna (Thunnus obesus) and yellowfin tuna (T. albacares) are investigated. The TS of bigeye tuna was about 3 dB higher than yellowfin tuna when comparing species at the same size. The result can be correlated to the swimbladder volume differencebetween species. The relationship between TS and swimbladder volume was quantified for both species.Keywords: tuna fish, target strength, quantitative echo sounder

Control Theory and Decision Making in Organisations A Reconnaissance

1970 ◽  
Vol 3 (3) ◽  
pp. T46-T48 ◽  
Author(s):  
G. L. Mallen
Keyword(s):  
Control Theory ◽  
Control Systems ◽  
Decision Process ◽  
Transfer Functions ◽  
Social Systems ◽  
Simulation Methods ◽  
Industrial Dynamics ◽  
Simulation Approach ◽  
Decision Systems ◽  
Classical Control

Differences between the domains of application of classical control theory and applied cybernetics are examined. It is suggested that a unifying concept for the understanding of both simple mechanical control systems and complex social systems is that of the decision process. Simple decision systems are equated to those for which transfer functions can be specified. Complex systems demand a simulation approach. No prescriptive organisational control theory based on simulation methods yet exists but one is required and is seen to be emerging from such diverse fields as artificial intelligence and Industrial Dynamics.

Interpretation of shadowgraph patterns in Rayleigh-Bénard convection

1988 ◽  
Vol 190 ◽  
pp. 451-469 ◽  
Author(s):  
D. R. Jenkins
Keyword(s):  
Rayleigh Number ◽  
Linear Theory ◽  
Vertical Component ◽  
Fluid Flows ◽  
Bénard Convection ◽  
Benard Convection ◽  
Higher Order Terms ◽  
The Relationship ◽  
Rayleigh Benard Convection ◽  
Rayleigh Benard

The relationship between observations of cellular Rayleigh-Bénard convection using shadowgraphs and theoretical expressions for convection planforms is considered. We determine the shadowgraphs that ought to be observed if the convection is as given by theoretical expressions for roll, square or hexagonal planforms and compare them with actual experiments. Expressions for the planforms derived from linear theory, valid for low supercritical Rayleigh number, produce unambiguous shadowgraphs consisting of cells bounded by bright lines, which correspond to surfaces through which no fluid flows and on which the vertical component of velocity is directed downwards. Dark spots at the centre of cells, indicating regions of hot, rising fluid, are not accounted for by linear theory, but can be produced by adding higher-order terms, predominantly due to the temperature dependence of a material property of the fluid, such as its viscosity.

Co-operation as a Conditional Strategy among Peers: Influence of Social Ecology and Kin Relations

1996 ◽  
Vol 19 (1) ◽  
pp. 39-52 ◽  
Author(s):  
Peter J. LaFreniere
Keyword(s):  
Peer Relations ◽  
Research Programme ◽  
Conditional Strategy ◽  
Social Unit ◽  
Kin Relations ◽  
Sources Of Variation ◽  
The Individual ◽  
Developmental Significance ◽  
The Relationship

The goal of this study is to analyse sources of variation, residing within the individual or within the relationship, in the ability to balance co-operative and competitive behaviours in a dyadic context. The ability to balance these two tendencies can be considered fundamental to successful adaptation within a social unit because co-operation may be essential in raising offspring, competing with other groups or in generating resources, whereas egoistic behaviour may protect the individual from exploitation or otherwise enhance reproductive success. Research is reviewed on the influence of social structures and relationships on co-operation in peer groups, and the origin and developmental significance of individual differences in co-operative abilities. Finally, a research programme investigating the conjunction of kin and peer relations is described, emphasising the role of affective synchrony, behavioural contingency, and reciprocity in shaping and sustaining co-operative behaviour as a conditional strategy.

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