Built-in Error Research Articles

On the computational aspects of Rosenbrock procedures with built-in error estimates for stiff systems

A third orderA-stable Rosenbrock method with built-in error estimate is developed by modifying an idea of J. R. Cash. Comparative tests are presented.

A computer feedback system for clinical research

This paper presents a computerized data base management and information retrieval system for a heroin addiction research clinic, which has potential application for any type of clinical research. It describes data input checking programs, file structures, and output programs. The system contains several interesting features: built-in feedback error detection and correction; patient month matrix formatting and data compression; and a virtual blocking system to reduce the size of the files.

Generating Bessel functions in Mie scattering calculations using continued fractions

A new method of generating the Bessel functions and ratios of Bessel functions necessary for Mie calculations is presented. Accuracy is improved while eliminating the need for extended precision word lengths or large storage capability. The algorithm uses a new technique of evaluating continued fractions that starts at the beginning rather than the tail and has a built-in error check. The continued fraction representations for both spherical Bessel functions and ratios of Bessel functions of consecutive order are presented.

Age distribution, education and societal structure

Age distribution, educational distribution and societal structure are interrelated parameters that, in the past, were adjusted to each other in an equilibrium that was only perturbed by rather small and slow changes. Built-in trial and error control mechanisms were evidently capable of containing these minor perturbations without excessive instabilities. Recently, major and fast changes have been occurring in the age distribution through the substantial extension of human life expectancy, and in the educational distribution through the wide availability of educational opportunities. The existing trial and error control mechanisms seem to be inadequate for such major perturbations, and new controls will have to be introduced in order to avoid serious instability and disruption. While the age distribution cannot be controlled through morally acceptable means, ways must be found to control the educational distribution, and to match it to existing societal needs.

A computer process for substructure searches on compound structures ciphered in the IUPAC notation

Computer programs have been written which enable substructure searches to be carried out on a file of compounds ciphered using a modified version of the IUPAC (Dyson) notation. Search input is in the form of from one to three special data cards, the preparation of which does not necessarily require a detailed knowledge of the notation. Substructure searches are divided into four categories, depending on the complexity of the request and the suitability of the notation for handling it. These are: (a) Those involving direct matches against strings of characters present in the cipher. (b) Those in which a specified group has a number of stated substituents, (c) Searches as in (b) in which the relative locations of the substituent are to be considered. (d) Searches best carried out by using an atom-connection process. Searches of the first two types account for the majority of requests received, and these can often be dealt with immediately. Preparation of input data takes only a few minutes and computer time used (Univac 9300) to search a file of 50,000 compounds is normally 15–20 min, although some searches have to be divided into two or more separate runs. Output is at present as compound reference number, cipher and comments, but a structural formula output for about half the file is available via the chemical structure typewriter. The search procedures are constantly being improved on the basis of feedback obtained from actual substructure searches, and erroneous ciphers can be detected by built-in error detection routines. These routines also list certain complex types of compound which as yet cannot adequately be dealt with by the existing search procedures. The search system outlined is to be linked with one which uses input from the chemical structure typewriter. A computer program converting ciphers into atom-connection tables has been developed for this purpose.

Political Parties in Mainland Malaya

Whatever impact the formation of Malaysia had on the areas involved, the merger, in 1963, of mainland Malaya with Singapore, Sarawak, and Sabah (North Borneo) — and the separation of Singapore in 1965 — has been a complication in the life of the political analyst in the midst of efforts to formulate generalizations about the country's political life. Obviously adjustments are being made in the whole range of political affairs as the various components of the enlarged federation are in the course of integration into a single operating political system. Yet, differences remain, and there is still much to be learned by considering the component parts as separate entities. Distortions will result from such a procedure, but as long as the researcher and his audience are alerted to the distortions, and no claim of completeness made, the built-in error need not be too misleading.