Implicit Runge-Kutta algorithms, in contrast to the explicit algorithms, are easily derivable to any order. The primary disadvantage of the method is the often slow convergence of the interative procedures that are inherent to the implicit algorithms. Recent developments have alleviated this disadvantage. Furthermore, efficient algorithms have been developed that include a reliable automatic step size control. The coefficients for implicit Runge-Kutta algorithms are derived for systems of first and of second order ordinary differential equations. The strategy for the acceleration of the convergence of a step is developed, and the stepsize control and error control are developed. Numerical comparisons are made for a selection of test problems between the implicit Runge-Kutta methods and explicit Runge-Kutta, multistep, and extrapolation methods.
{"title":"Recent developments with implicit Runge-Kutta algorithms","authors":"D. G. Bettis","doi":"10.1145/1408800.1408919","DOIUrl":"https://doi.org/10.1145/1408800.1408919","url":null,"abstract":"Implicit Runge-Kutta algorithms, in contrast to the explicit algorithms, are easily derivable to any order. The primary disadvantage of the method is the often slow convergence of the interative procedures that are inherent to the implicit algorithms. Recent developments have alleviated this disadvantage. Furthermore, efficient algorithms have been developed that include a reliable automatic step size control.\u0000 The coefficients for implicit Runge-Kutta algorithms are derived for systems of first and of second order ordinary differential equations. The strategy for the acceleration of the convergence of a step is developed, and the stepsize control and error control are developed. Numerical comparisons are made for a selection of test problems between the implicit Runge-Kutta methods and explicit Runge-Kutta, multistep, and extrapolation methods.","PeriodicalId":204185,"journal":{"name":"ACM '74","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124106269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The major thrust toward providing secure computing facilities has gone into the design of, or models for, new operating systems. Work directed toward securing current systems has, for the most part, taken the form of penetration attempts. Penetration efforts have led several authors to identify generic weaknesses, but grouping by weakness has not led to formal methods. An approach showing greater promise in identifying trouble spots, as well as characterizing existing operating systems in a more general sense, lies in forming graph models in which nodes are program modules or data structures, and arcs are access or shared resource synchronization paths. A given system should be capable of reduction to a graph of this sort by appropriate analysis of its load modules.
{"title":"A model highlighting the security of operating systems","authors":"R. Conn, Richard H. Yamamoto","doi":"10.1145/800182.810399","DOIUrl":"https://doi.org/10.1145/800182.810399","url":null,"abstract":"The major thrust toward providing secure computing facilities has gone into the design of, or models for, new operating systems. Work directed toward securing current systems has, for the most part, taken the form of penetration attempts. Penetration efforts have led several authors to identify generic weaknesses, but grouping by weakness has not led to formal methods. An approach showing greater promise in identifying trouble spots, as well as characterizing existing operating systems in a more general sense, lies in forming graph models in which nodes are program modules or data structures, and arcs are access or shared resource synchronization paths. A given system should be capable of reduction to a graph of this sort by appropriate analysis of its load modules.","PeriodicalId":204185,"journal":{"name":"ACM '74","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126252513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Methods like the Runge-Kutta family for the solution of ordinary differential equations produce approximate solutions only at mesh points. The efficiency of such methods is greatly reduced if the user requests output too frequently. This paper justifies interpolating to resolve this difficulty. In addition the use of interpolation to approximate the derivatives of the solution is justified
{"title":"Interpolating numerical solutions of ordinary differential equations","authors":"M. Gordon, L. Shampine","doi":"10.1145/800182.810378","DOIUrl":"https://doi.org/10.1145/800182.810378","url":null,"abstract":"Methods like the Runge-Kutta family for the solution of ordinary differential equations produce approximate solutions only at mesh points. The efficiency of such methods is greatly reduced if the user requests output too frequently. This paper justifies interpolating to resolve this difficulty. In addition the use of interpolation to approximate the derivatives of the solution is justified","PeriodicalId":204185,"journal":{"name":"ACM '74","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126220257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Computerized symbolic integration is used in developing finite element programs. Several classes of integrals which arise in two-dimensional problems are examined to determine whether symbolic integration can compete with numerical quadrature. Group theoretic techniques are employed to reduce the amount of symbolic computation.
{"title":"Use of computerized symbolic integration in finite element development","authors":"C. Andersen","doi":"10.1145/1408800.1408851","DOIUrl":"https://doi.org/10.1145/1408800.1408851","url":null,"abstract":"Computerized symbolic integration is used in developing finite element programs. Several classes of integrals which arise in two-dimensional problems are examined to determine whether symbolic integration can compete with numerical quadrature. Group theoretic techniques are employed to reduce the amount of symbolic computation.","PeriodicalId":204185,"journal":{"name":"ACM '74","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131965029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The need for better understanding of human behavior in the Management Information Systems (MIS) environment has been recognized. One method of examining this behavior is to describe man as an information processor and focus on his ability to store, retrieve and utilize information. The use of design criteria which explicitly recognize man's limitations in these areas can enhance overall system performance. Consideration of several criteria to be used in the design of interactive languages is given. Finally, the hypothesis that with an interactive system “perceived&rdquo response time is more important than actual response time is presented. Results of preliminary experiments are included.
{"title":"Human factors design criteria in man-computer interaction","authors":"Charles J. Testa, Douglas B. Dearie","doi":"10.1145/800182.810380","DOIUrl":"https://doi.org/10.1145/800182.810380","url":null,"abstract":"The need for better understanding of human behavior in the Management Information Systems (MIS) environment has been recognized. One method of examining this behavior is to describe man as an information processor and focus on his ability to store, retrieve and utilize information. The use of design criteria which explicitly recognize man's limitations in these areas can enhance overall system performance. Consideration of several criteria to be used in the design of interactive languages is given. Finally, the hypothesis that with an interactive system “perceived&rdquo response time is more important than actual response time is presented. Results of preliminary experiments are included.","PeriodicalId":204185,"journal":{"name":"ACM '74","volume":"21 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132132001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
When one contrasts the keypunch with some of the devices being marketed today, the Virginia Slims commercial comes to mind. Indeed, we've "come a long way." The products now available are sophisticated and diverse elaborations of the basic data entry device. And yet, they constitute only new responses to a basic requirement for computer technology. Computers do not yet talk as men do and the data entry industry has evolved from the need to translate human-sensible information into machine-sensible data. Up to now the accent has been on making the man conform.
{"title":"Data entry, future tense","authors":"Evelyn McDonald","doi":"10.1145/1408800.1408895","DOIUrl":"https://doi.org/10.1145/1408800.1408895","url":null,"abstract":"When one contrasts the keypunch with some of the devices being marketed today, the Virginia Slims commercial comes to mind. Indeed, we've \"come a long way.\" The products now available are sophisticated and diverse elaborations of the basic data entry device. And yet, they constitute only new responses to a basic requirement for computer technology. Computers do not yet talk as men do and the data entry industry has evolved from the need to translate human-sensible information into machine-sensible data. Up to now the accent has been on making the man conform.","PeriodicalId":204185,"journal":{"name":"ACM '74","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131756904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A real-time, on-line information storage and retrieval system for telephone information service has been designed. The input and output of the system are processed in Chinese via a keyboard and a graphic display unit respectivey. Functions of the system include: sorting, merging, updating, displaying, and printing of data. In order to avoid a serial, exhaustive search, the file is subdivided into blocks of length x. The optimal size of each block is determined so that the average number of comparisons (file accesses) to locate a record is minimized versus some combined search methods. The system has been tested on a telephone office of medium capacity, roughly 8000 subscribers. The number of daily queries is about 1600 and the updating rate is approximately 50. By comparison of the slowest system's response time (0.24 sec.) with the quickest manual response time, the system is, at least , 130 times faster.
{"title":"An automatic telephone directory inquiry service system","authors":"Y. Chin, Jun-Wun Jou, W. Peng, C. Yang","doi":"10.1145/800182.810407","DOIUrl":"https://doi.org/10.1145/800182.810407","url":null,"abstract":"A real-time, on-line information storage and retrieval system for telephone information service has been designed. The input and output of the system are processed in Chinese via a keyboard and a graphic display unit respectivey. Functions of the system include: sorting, merging, updating, displaying, and printing of data.\u0000 In order to avoid a serial, exhaustive search, the file is subdivided into blocks of length x. The optimal size of each block is determined so that the average number of comparisons (file accesses) to locate a record is minimized versus some combined search methods.\u0000 The system has been tested on a telephone office of medium capacity, roughly 8000 subscribers. The number of daily queries is about 1600 and the updating rate is approximately 50. By comparison of the slowest system's response time (0.24 sec.) with the quickest manual response time, the system is, at least , 130 times faster.","PeriodicalId":204185,"journal":{"name":"ACM '74","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133512441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The global error at any point in the step by step numerical solution of an initial value problem is the sum of local errors introduced at every step, each multiplied by an amplification factor due to the stability or instability of the differential equation. If these factors were unity (as, for example, in a quadrature problem) it is possible to keep the global error e(t) over the interval [a, b] less than Δ by keeping the local error in a step of length h less than hΔ/(b-a). This is called error per unit step. Unfortunately, theory shows that the error strategy which minimizes the amount of work for a given global error Δ is to make the local error equal to g(Δ) where, for a pth order method, g(Δ) = q(t)Δ(p+1)/P+ higher terms, and q(t) depends on the differential equation. The talk will present experimental evidence of the increased efficiency of error per step versus the smoother dependence of the global error on the error control parameter for error per unit step. The existing theory will be summarized, and the question of how the local error estimate can be justified theoretically will be examined.
{"title":"Error estimation and control in O.D.E. integration","authors":"C. Gear","doi":"10.1145/1408800.1408920","DOIUrl":"https://doi.org/10.1145/1408800.1408920","url":null,"abstract":"The global error at any point in the step by step numerical solution of an initial value problem is the sum of local errors introduced at every step, each multiplied by an amplification factor due to the stability or instability of the differential equation. If these factors were unity (as, for example, in a quadrature problem) it is possible to keep the global error e(t) over the interval [a, b] less than Δ by keeping the local error in a step of length h less than hΔ/(b-a). This is called error per unit step. Unfortunately, theory shows that the error strategy which minimizes the amount of work for a given global error Δ is to make the local error equal to g(Δ) where, for a pth order method, g(Δ) = q(t)Δ(p+1)/P+ higher terms, and q(t) depends on the differential equation.\u0000 The talk will present experimental evidence of the increased efficiency of error per step versus the smoother dependence of the global error on the error control parameter for error per unit step. The existing theory will be summarized, and the question of how the local error estimate can be justified theoretically will be examined.","PeriodicalId":204185,"journal":{"name":"ACM '74","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133177907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A star-shaped network of mini-computers provides all remote computers access of commonly used peripherals and the University's CDC 6400. The key hardware feature, independent of computer type, is asynchronous serial communication at 153,000 baud with character rate dictated by the receiving computer. Interconnection hardware and software overhead is minimal. The key software feature is the loose connection of near homogeneous machines. Real-time constraints are satisfied by remote computers with idle machines potentially available as a distributed intelligence resource to support additional computer types. Minimal computers may be supported to run unmodified, paper-tape oriented programs using a transparent monitor. Computers with adequate memory may be supported to run mass memory operating systems using Network Central resources. The cost per computer is less than that for paper-tape equipment, while only under heavy load conditions does performance degrade to paper-tape speeds.
{"title":"A mini-computer network for support of real time research","authors":"W. Lennon","doi":"10.1145/1408800.1408861","DOIUrl":"https://doi.org/10.1145/1408800.1408861","url":null,"abstract":"A star-shaped network of mini-computers provides all remote computers access of commonly used peripherals and the University's CDC 6400. The key hardware feature, independent of computer type, is asynchronous serial communication at 153,000 baud with character rate dictated by the receiving computer. Interconnection hardware and software overhead is minimal. The key software feature is the loose connection of near homogeneous machines. Real-time constraints are satisfied by remote computers with idle machines potentially available as a distributed intelligence resource to support additional computer types. Minimal computers may be supported to run unmodified, paper-tape oriented programs using a transparent monitor. Computers with adequate memory may be supported to run mass memory operating systems using Network Central resources. The cost per computer is less than that for paper-tape equipment, while only under heavy load conditions does performance degrade to paper-tape speeds.","PeriodicalId":204185,"journal":{"name":"ACM '74","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123909176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The value of incremental information in an interactive group estimation task","authors":"N. Dalkey","doi":"10.1145/1408800.1408818","DOIUrl":"https://doi.org/10.1145/1408800.1408818","url":null,"abstract":"","PeriodicalId":204185,"journal":{"name":"ACM '74","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124270333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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