ACM '58最新文献

{"title":"Second order formulas for Fourier coefficients","authors":"H. F. Hunter","doi":"10.1145/610937.610982","DOIUrl":"https://doi.org/10.1145/610937.610982","url":null,"abstract":"This paper presents formulas for Fourier coefficients which are exact for parabolic polygons determined by triples of points at unequal intervals. Thus points may be chosen quite far apart in the ,nearly linear portion of a curve to be analyzed. This will usually reduce by a factor of two the number of points required for a given accuracy.","PeriodicalId":174899,"journal":{"name":"ACM '58","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1958-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114752121","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":"A command language for handling strings of symbols","authors":"A. Perlis, J. Smith","doi":"10.1145/610937.610965","DOIUrl":"https://doi.org/10.1145/610937.610965","url":null,"abstract":"In the past few years , a great deal of creat ive programming effort has been spent in the cons t ruct ion of automatic coding s y s t e m s \" in te rpre te r s\" , \" a s semble r s \" , \"compi lers\" . Two fac to rs , both basic to the design and construct ion of such sys tems , have been the cause of much of the t ime and eIfort expended; indeed, these sys tems have been constructed without actually resolving these two diff iculties. F i rs t , the only languages available for describing the efforts (and the sys tems themselves) are:","PeriodicalId":174899,"journal":{"name":"ACM '58","volume":"142 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1958-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126125660","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":"On initial estimates for computing a1/p by Newton's method","authors":"J. Derr","doi":"10.1145/610937.610980","DOIUrl":"https://doi.org/10.1145/610937.610980","url":null,"abstract":"Consider the problem of the numerical evaluation of a I/p by Newton's method on the interval ]O, , where p is an integer greater than one. If a is fixed but arbitrary in IJ, the natural approach is to pick an initial estimate x O and then starting with x O to obtain by Newton's method a sequence (Xl,X2,... , XN)such that /x N al/P/ ~ ~ , where ~ is a preassigned positive number. For such sequences Ix~ we shall say that (x~r converges to a I/p and that N iterations are required for convergence. If, in addition, x O ~ a I/p, the convergence of (Xn~ to a I/p is monotone. Since monotone convergence is very convenient for digital computers we shall require x O ~ a I/p. We now consider some expressions for x O as a function of a and p which satisfy either or both of the properties that (i) x O shall be simple to compute and (ii) the number N of iterations required for the convergence of","PeriodicalId":174899,"journal":{"name":"ACM '58","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1958-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128045546","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":"An alternating direction method for solving the biharmonic equation","authors":"S. D. Conte, R. T. Dames","doi":"10.1145/610937.610943","DOIUrl":"https://doi.org/10.1145/610937.610943","url":null,"abstract":"The purpose of this paper is to present an alternating direction implicit iterative method for solving the biharmonic equation which appears to be more efficient than any of the known relaxation methods. The procedure is an extension of a method developed by Douglas and Rachford [1] for solving diffusion equations in two or more space variables.","PeriodicalId":174899,"journal":{"name":"ACM '58","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1958-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131987291","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":"Automatic propagated and round-off error analysis","authors":"P. C. Fischer","doi":"10.1145/610937.610971","DOIUrl":"https://doi.org/10.1145/610937.610971","url":null,"abstract":"The routine described below is a modification of the Carnegie Tech (IT) Compiler system for the IBM-650, which will provide automatic empirical analysis of propagated and round-off errors in computation. In the modified system, three kinds of variables are admissable: fixed-point integers called I-variables; floating-point numbers called C-variables, which are considered to be exact values; and 2-word variables called Y-variables, in which one word is a floating-point number which represents the value of the variable and the other word represents a bound upon the propagated and round-off error present in that value. Statements written in the IT language may refer to any or all of these classes of variables. During the execution phase of a program, computation proceeds in typical fashion, except that each time a Y-variable is operated upon by the program, its error term is modified so as to represent a valid bound upon propagated and round-off error in the variable.","PeriodicalId":174899,"journal":{"name":"ACM '58","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1958-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127481174","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":"Nonlinear programming computations","authors":"P. Wolfe","doi":"10.1145/610937.610958","DOIUrl":"https://doi.org/10.1145/610937.610958","url":null,"abstract":"This paper is concerned with two recently developed computational algorithms for the solution of particular classes of nonlinear programming problems.","PeriodicalId":174899,"journal":{"name":"ACM '58","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1958-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114060766","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":"Programming and modification in the SHARE 709 system","authors":"Irwin D. Greenwald, M. Kane","doi":"10.1145/610937.610952","DOIUrl":"https://doi.org/10.1145/610937.610952","url":null,"abstract":"Abstract : The SHARE 709 system permits the programmer to communicate with the machine and with itself entirely in a symbolic language. The compiler specifications including instruction format, pseudo operations, program library, and system and programmer-macro operation generators are described. The methods for handling symbolic input/output, symbolic debugging, and symbolic modification of a compiled program are discussed. (Author)","PeriodicalId":174899,"journal":{"name":"ACM '58","volume":"96 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1958-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114566613","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":"SHARE 709 system: a cooperative effort","authors":"D. Shell","doi":"10.1145/610937.610951","DOIUrl":"https://doi.org/10.1145/610937.610951","url":null,"abstract":"SHAP~E was created in August 1955. From the beginning its aim has been to reduce redundant effort among various users of the IBM 704, insofar as the preparation of commonly used routines is concerned. The organization has operated on a cooperative basis-establishing a standard language of communication and exchanging a large number of programs which form the tools for effectively using the computer. This standard language of communication is that used in the SHARE Assembly Program, which was developed by United Aircraft Corporation and patterned after the first such program for the 704 which was developed under my direction by the General Electric Company. At the SHARE meeting held in December 1956, the organization anticipated the forthcoming IBM 709 which was similar in a great many respects to the machine around which the organization was originally built. In order to have a set of programs available for use upon delivery of the new machine, the organization established a 709 System Committee which was given the task of preparing a \"system\" for using the machine. I was made Chairman of this C ommitte e. Various installations volunteered individuals for service on this committee on a \"full time basis\". The authors of the papers being presented in this session were selected by the Committee Chairman and the SHARE Executive Board for participation on the committee. The initial problem facing the committee was to define what was meant by a system. The scope of the anticipated system varied greatly in the minds of the various members of the committee. After due consideration, it was decided to specify ~ complete installation operational system with all the fundamental necessities for effective machine utilization supplied. The committee would use the best experience available and advance the art of machine usage, if possible. However, it would not attempt any features of such novelty as to endanger completion of the system in the time available. Some of the objectives to be sought were simplicity, non-stop machine operation, card-tape input interchangeability, minimum programmer constraints, automatic error detection , and the ability to handle the SHARE 704 language wherever possible. The most important advance made in the system over previous developments is in the area of program debugging. It was felt by the committee that if any true advancement were to be made in this direction, especially in higher language coding situations, it was going to be necessary to make …","PeriodicalId":174899,"journal":{"name":"ACM '58","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1958-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122628815","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":"Efficient method for solving atomic Schroedinger's equation","authors":"S. Skillman","doi":"10.1145/610937.610940","DOIUrl":"https://doi.org/10.1145/610937.610940","url":null,"abstract":"The determination of the eigenvalue satisfying the boundary conditions of Schroedinger's wave equation requires an efficient computational procedure. The method described here, starting with a reasonable trial eigenvalue, will converge to the eigenvalue accurate to five significant figures in four or five iterations. The Schroedinger's equation in atomic units (I~ in Bohr radii, E in Rydbergs) is given by d2p(*)) d~ 2 = q(~)P(~), for O-~J~-~-~x~, where q(@) = V(~)-E + ~(i~l) In this equation P(.~) is the radial wave function, V(~) is the potential energy, and E is the desired eigenvalue satisfying the conditions P(O) = O and P(~) = O. These numerical values ore are sometimes designated as s, p, d, etc. For each ~ , there is a set of eigenvalues satisfying the boundary values which are labeled by an integer n. The lowest state for each value of ~ is taken as n = ~ + 1 and for each n, the principal quantum number, there is a distinct energy value E. Thus the various radial wave functions and associated eigenvalues can be specified using the subscript n~. The Noumerov I method is used for integrating Shcroedinger's equation. This method is considered the most practical one for this linear second-order equation. It is approximately four times faster than the Runge-Kutta-Gill procedure and the truncation error is proportional to h 6. The integration mesh is made a function of the atomic structure by defining the integration variable x = .~ UA~. In this equation~ = 377/4(677Z) I/3 where Z is the atomic number. The initial integration step is made equal to h = ~ x = 2.5\" 10-3 and is automatically doubled every forty mesh points. When the equation is integrated outward from .~ = O toward J~ = ~ it is found that the values I~(~) in the outer damped region are extremely sensitive to the choice of E. Correspondingly if the equation is integrated inward from J~ = CQ towardJ~ = O, the values P(.z l) in the inner traveling-wave region are extremely sensitive to the choice of E. In order to get rid of this over-sensitivity the equation is integrated outward from the origin to x = R 1 and then integrated inward from 1.","PeriodicalId":174899,"journal":{"name":"ACM '58","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1958-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125288951","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":"Computer transcription of manual morse","authors":"C. R. Blair","doi":"10.1145/610937.610974","DOIUrl":"https://doi.org/10.1145/610937.610974","url":null,"abstract":"A radio telegrapher can, by operating a key, turn a transmitter on or off for any desired period. Morse code is predicated on controlling these parameters of key position a2id the duration ol the signal. A message is converted into a sequence of five elementary symbols: the dora dash, intra~ character space, inter-character space and inter-word space. In terms of an arbitrary unit of time, determined by the sender, a dot results from closing the key for one time-unit and a dash for three time-units. An intra-character space results from opening the key for one time-unit, an inter-character space for three time-units, and an inter-word space for seven time-units. All letters, numbers, punctuation marks and several brevity codes are represented by sequences of dots, dashes and intra-charaeter spaces. (These code symbols are separated in a message by inter-character or inter-word spaces). Thus any message that can be transmitted by a sequence of characters can be broken down into a sequence of the five primary elements for transmission by radio-telegraph.","PeriodicalId":174899,"journal":{"name":"ACM '58","volume":"609 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1958-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125147078","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}