equally spaced record intervals and transcribed onto punch cards. This 

 information is then sent to the Applied Mathematics Laboratory where it 

 is transferred to a digital tape for input to the general purpose digital 

 computer. In addition to being time consuming, errors occur in reading, 

 card punching, and computation which are often not discovered until the 

 results are returned to the project manager. Furthermore, there is often 

 a delay of several days in gaining access to the computer. Data preparation 

 may be streamlined by analog to digital converters (if the original data 

 is on analog tape) , but this is an expensive undertaking and does not solve 

 all the problems mentioned. 



A more serious deficiency of the general purpose computer is that 

 it is physically remote from the project manager. This eliminates all 

 subjectivity in analysis. The project manager must decide, a priori, 

 how the analysis will be made, i.e., resolution and confidence. There is 

 no opportunity to "play" with the analyzer, to learn whether certain 

 information (such as the occurrence of slamming) , which can only be 

 extracted from the data by changing the analysis constants during the 

 analysis, really exists. A more direct example of the disadvantage of 

 physical apartness of the computer and the project manager can be seen 

 in the seakeeping facility. Model test programs often require alter- 

 ation; that is, results may indicate that data are over-abundant in 

 some areas and sparse in others. Test programs can be altered profitably, 

 only if the results are available while the experiment is being conducted, 

 not the next week or even the next day. 



In certain operational problems, a knowledge of past history of ship 



2 



