Modular program with a small main program and several specialized subroutines provides a general purpose computer program to simulate the design, test and analysis phases of sensitivity experiments. This program allows a wide range of design-response function combinations and the addition, deletion, or modification of subroutines

Alexander, M. J.

Rothman, D.

Zimmerman, J. M.

English

NASA Technical Reports Server

April 1967	 Brief 67-10077 
NASA TECH BRIEF 
NASA Tech Briefs are issued to summarize specific innovations derived from the U.S. space program, 
to encourage their commercial application. Copies are available to the public at 15 cents each 
from the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia 22151. 
Computer Program Simulates Design, Test, and Analysis

Phases of Sensitivity Experiments 
I	 Read Control Variables and Initialize 	 I 
I	 Call EXPDES to generate S IN), the sirens 
I	 Leriel for the Upcoming Test 
Call MEANR to Generate BETA, a Response

Function Value Corresponding to SIN) 
Generate ALPHA. a Random Number

If	 PHA BETA- 
Testis Recorded	 Test is Recorded 
asa Success,	 as a Failure. 
G(N) = 1.0	 GIN) 0.0 
Update Vectors in Which Sirens Levels

and Results are Summarized
)l'	 Call ANALYZ to 
Update N An Perform Analysis 
the Tea of Tent Data 
)No) 
Jj m NoI Ha vI liRlir 
ReqE
..,.
 
Been Com ompleted
	
This 
Sim 
(Yes) 
Simulation Simulation ntout of 
0=t .4 -
case has Analysis Results
Call PLOT 
for CRT 
The problem: 
To devise a general purpose computer program for 
the simulation of the design, test and analysis phases 
of sensitivity experiments. Such simulation is cur-
rently accomplished with special purpose computer 
programs. These programs generally do not provide a 
wide range of design-response function combinations
and do not readily allow addition, deletion, or modifi-
cation of subroutines to implement different types of 
designs. 
The. solution: 
A modular program consisting of a relatively small 
main program and a number of specialized subrou-
tines. Three of the subroutines are essentially buffer 
)continued overleaf) 
This document was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States 
Government nor any person acting on behalf of the United States
Government assumes any liability resulting from the use of the 
information contained in Ihis document, or warrants that such use 
will be free from privately owned rights. 
https://ntrs.nasa.gov/search.jsp?R=19670000077 2020-03-11T20:44:03+00:00Z
routines used to call the specific routine required to 
implement the particular experimental design, 
response function, and analysis desired. Two utility 
subroutines handle the program output. 
How it's done: 
The desired experimental design, response function, 
and analysis procedures are specified by means of 
input control variables. The design routine is used to 
furnish a stress level for the first test and the corre-
sponding response value is computed by the response 
function routine. 
To introduce the randomness which characterized 
certain aspects of all tests, the response value is com-
pared to a random number, uniformly distributed in 
[0, 11 and generated within the program. If the ran-
dom number is greater than the response value, the 
test is recorded as a success. If, however, the random 
number is less than the response value, the test is a 
failure. 
The stress value, the response, and whether the test 
was a success or a failure are stored in the core 
memory. Then the test number is updated and a new 
stress value is determined from the design function. 
The above cycle is then repeated and the information 
stored. This loop recurs until all the desired tests in 
the first simulation are performed. Then a second 
simulation is begun with the test number reset to one. 
A maximum of 100 simulations, each consisting of 
up to 1024 tests, may be processed as a single data 
case. When these are completed, the results are all 
available in core storage. Then, for each simulation, 
estimates of the desired parameters are computed. 
Various characteristics of the response function can 
also be estimated, e.g., the stimulus levels correspond-
ing to the 1% and 0.1% response levels or the mean 
and standard deviation of the distribution.
From these estimates the program then computes, 
over all simulations, the mean, median, standard 
error, maximum, and minimum values of each param-
eter estimate. These are then printed out in the anal-
ysis summary along with the true values of each pa-
rameter. When there are two parameters, their sample 
covariance matrix is also provided. 
Notes: 
1. This is a Fortran II program, coded for the IBM 
7094. 
2. This program has been used to simulate the Bart-
lett, run-down, 20 ZIL, block sequential, Alex-
ander, and Rothman designs. Response functions 
which have been used in conjunction with these 
designs include the cumulative normal and cumula-
tive uniform, those of Odell, and several special 
functions. 
3. Maximum-likelihood estimation, predicted on the 
normal response function, and the method of re-
versals are the techniques of analysis which have 
received the most extensive use with this program. 
4. Inquiries concerning this innovation may be di-
rected to:	 COSMIC 
Computer Center 
University of Georgia 
Athens, Georgia 30601 
Reference: B67-10077 
Patent status: 
No patent action is contemplated by NASA. 
Source: D. Rothman, M. J. Alexander, 
and J. M. Zimmerman 
of North American Aviation, Inc. 
under contract to 
Marshall Space Flight Center 
(M-FS- 1496) 
Brief 67-10077	 .	 .	 Category 01


Computer program simulates design, test, and analysis phases of sensitivity experiments

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