The syntax of the DO-WHILE is revised so as to distinguish the semantics of logical control of iteration from those of site of test within the scope of the DO. The corresponding control graph (flowchart subdiagram) is shown to be a combination of previously used alternative forms. An indentation scheme is proposed in which the indentation rules are identical for both iterative and conditional statements. Furthermore the rules as given are identical for any programming language, whether it is a lower level language which requires hand coded book-keeping statements or some ideal language in which all loop control is provided for in the syntactic forms. The minimal sufficient set of program control structures is augmented with forms for the convenience of human program writers and readers. These forms all share common indentation rules corresponding to those used for the DO-WHILE and IF-THEN-ELSE. Last a form is provided for handling error conditions, POSIT-QUIT-ADMIT in which multiple QUITs are permitted. The indentation rules are compatible with the preceding rules.
{"title":"On program control structure","authors":"P. M. Neely","doi":"10.1145/800192.805692","DOIUrl":"https://doi.org/10.1145/800192.805692","url":null,"abstract":"The syntax of the DO-WHILE is revised so as to distinguish the semantics of logical control of iteration from those of site of test within the scope of the DO. The corresponding control graph (flowchart subdiagram) is shown to be a combination of previously used alternative forms. An indentation scheme is proposed in which the indentation rules are identical for both iterative and conditional statements. Furthermore the rules as given are identical for any programming language, whether it is a lower level language which requires hand coded book-keeping statements or some ideal language in which all loop control is provided for in the syntactic forms.\u0000 The minimal sufficient set of program control structures is augmented with forms for the convenience of human program writers and readers. These forms all share common indentation rules corresponding to those used for the DO-WHILE and IF-THEN-ELSE. Last a form is provided for handling error conditions, POSIT-QUIT-ADMIT in which multiple QUITs are permitted. The indentation rules are compatible with the preceding rules.","PeriodicalId":72321,"journal":{"name":"ASSETS. Annual ACM Conference on Assistive Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1973-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77667268","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 tool, called LOCALIZER, which improves the locality of programs for multiprogrammed virtual-memory computer systems, is described. The method of critical working sets, which is the basis of the tool, is presented. This method is especially suitable for those systems where primary memory is managed according to the working set strategy. The various modules of the tool are briefly described after a discussion of the general restructuring procedure. (This research was supported in part by the Advanced Research Projects Agency, under Contract No. DACH15 70C 0274.)
{"title":"A tool for automatic program restructuring","authors":"D. Ferrari","doi":"10.1145/800192.805709","DOIUrl":"https://doi.org/10.1145/800192.805709","url":null,"abstract":"A tool, called LOCALIZER, which improves the locality of programs for multiprogrammed virtual-memory computer systems, is described. The method of critical working sets, which is the basis of the tool, is presented. This method is especially suitable for those systems where primary memory is managed according to the working set strategy. The various modules of the tool are briefly described after a discussion of the general restructuring procedure.\u0000 (This research was supported in part by the Advanced Research Projects Agency, under Contract No. DACH15 70C 0274.)","PeriodicalId":72321,"journal":{"name":"ASSETS. Annual ACM Conference on Assistive Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1973-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77675773","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}
This report describes a course entitled “Perspectives on computers and society” and presents findings from student assessments of course impact and attitude change. Almost all of the class members were computer science majors and they entered with rather favorable attitudes toward computerization. By the end of the quarter they were slightly less favorable toward the computer because of its perceived social impact. The desirability of this more balanced perspective is discussed.
{"title":"The impact of a computers and society course on student perspectives","authors":"P. Nicholson, W. Franta, Ronald E. Anderson","doi":"10.1145/800192.805685","DOIUrl":"https://doi.org/10.1145/800192.805685","url":null,"abstract":"This report describes a course entitled “Perspectives on computers and society” and presents findings from student assessments of course impact and attitude change. Almost all of the class members were computer science majors and they entered with rather favorable attitudes toward computerization. By the end of the quarter they were slightly less favorable toward the computer because of its perceived social impact. The desirability of this more balanced perspective is discussed.","PeriodicalId":72321,"journal":{"name":"ASSETS. Annual ACM Conference on Assistive Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1973-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76545294","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}
In this paper we describe an APL package developed for building statistical models interactively. The package consists of seven functional units with four major functions DATA, MODEL, REGRESSION and RESIDUAL, each of which is controlled by a set of commands. Several auxiliary functions are also available. The use of the package is illustrated through a numerical example.
{"title":"An interactive statistical modelling package in APL","authors":"Yuan Liu, A. Goel","doi":"10.1145/800192.805702","DOIUrl":"https://doi.org/10.1145/800192.805702","url":null,"abstract":"In this paper we describe an APL package developed for building statistical models interactively. The package consists of seven functional units with four major functions DATA, MODEL, REGRESSION and RESIDUAL, each of which is controlled by a set of commands. Several auxiliary functions are also available. The use of the package is illustrated through a numerical example.","PeriodicalId":72321,"journal":{"name":"ASSETS. Annual ACM Conference on Assistive Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1973-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76730587","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}
In this paper, a syntax-oriented formal system, called a metaprocess, is proposed for defining (and perhaps implementing) processes. The metaprocess functions as a kind of generalized metacompiler, in that it occupies the same relationship to a process as a metacompiler does to a compiler. The notion of an interpreter is developed to model the operation of each process and a metalanguage provides the vehicle for designating the actions performed by an interpreter. A combined syntactic-semantic specification of a process' input stream is used to drive the associated interpreter. The syntactic portion of this specification is in BNF while its semantic counterpart is in an Algol-like language. From this viewpoint, the inputs to the process serve as a sequence of directives to its interpreter.
{"title":"A syntax-oriented formal system for defining processes","authors":"C. R. Hollander","doi":"10.1145/800192.805720","DOIUrl":"https://doi.org/10.1145/800192.805720","url":null,"abstract":"In this paper, a syntax-oriented formal system, called a metaprocess, is proposed for defining (and perhaps implementing) processes. The metaprocess functions as a kind of generalized metacompiler, in that it occupies the same relationship to a process as a metacompiler does to a compiler. The notion of an interpreter is developed to model the operation of each process and a metalanguage provides the vehicle for designating the actions performed by an interpreter. A combined syntactic-semantic specification of a process' input stream is used to drive the associated interpreter. The syntactic portion of this specification is in BNF while its semantic counterpart is in an Algol-like language. From this viewpoint, the inputs to the process serve as a sequence of directives to its interpreter.","PeriodicalId":72321,"journal":{"name":"ASSETS. Annual ACM Conference on Assistive Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1973-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84673738","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}
Presented is a unified, systematic view of integrity/recovery as it relates to a data-processing system—whether man, machine, or both. The concept, sphere of control (SOC), as a bound around a process, is developed to permit describing and solving many of the rather aggravating problems of auditability, repeatability, reproducibility, scheduling, consistency, recovery and general integrity. Identified are the relationships among resources and SOCs, the types of resource status which must be maintained, and the effects that dependency versus commitment has on process scheduling and recovery strategy. Virtually ignored are the problems of lost storage for which redundancy is a solution, mainly because information already exists in this realm.
{"title":"Recovery semantics for a DB/DC system","authors":"Charles T. Davies","doi":"10.1145/800192.805694","DOIUrl":"https://doi.org/10.1145/800192.805694","url":null,"abstract":"Presented is a unified, systematic view of integrity/recovery as it relates to a data-processing system—whether man, machine, or both.\u0000 The concept, sphere of control (SOC), as a bound around a process, is developed to permit describing and solving many of the rather aggravating problems of auditability, repeatability, reproducibility, scheduling, consistency, recovery and general integrity.\u0000 Identified are the relationships among resources and SOCs, the types of resource status which must be maintained, and the effects that dependency versus commitment has on process scheduling and recovery strategy.\u0000 Virtually ignored are the problems of lost storage for which redundancy is a solution, mainly because information already exists in this realm.","PeriodicalId":72321,"journal":{"name":"ASSETS. Annual ACM Conference on Assistive Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1973-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87895106","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 number of approaches have been developed to modularize parts of multiuser computer systems so that access to each part can be controlled. The devices of rings and capabilities are two examples. However, today's systems are notably incomplete and subject to defeat by determined and clever users. A point of view is presented here which allows proving that a logical design of an access control system is correct relative to a designer-specified set of criteria. Implementation questions are also discussed.
{"title":"Correctness in access control","authors":"G. Popek","doi":"10.1145/800192.805711","DOIUrl":"https://doi.org/10.1145/800192.805711","url":null,"abstract":"A number of approaches have been developed to modularize parts of multiuser computer systems so that access to each part can be controlled. The devices of rings and capabilities are two examples. However, today's systems are notably incomplete and subject to defeat by determined and clever users. A point of view is presented here which allows proving that a logical design of an access control system is correct relative to a designer-specified set of criteria. Implementation questions are also discussed.","PeriodicalId":72321,"journal":{"name":"ASSETS. Annual ACM Conference on Assistive Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1973-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85463846","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}
Recently much interest has been expressed in the idea that future improvements in computer speed will be due primarily to architectural innovations as opposed to improvement in the characteristics of components (i.e., logic circuits, delays, memories, cycle times, etc.). In view of this it is not surprising that the current generation of “super computers” (i.e., the ILLIAC IV, the STAR 100, and the ASC) all exemplify the use of new architectures to achieve great increases in computing speeds. In this paper yet another new architecture is proposed - the inner product computer4. Like the ILLIAC IV it is a “special purpose” processor which is intended to be used in conjunction with a general purpose (i.e., host) computer.
最近，有一种观点引起了人们的极大兴趣，即未来计算机速度的提高将主要归功于架构的创新，而不是组件特性(即逻辑电路、延迟、存储器、循环时间等)的改进。鉴于此，当前一代的“超级计算机”(即ILLIAC IV, STAR 100和ASC)都是使用新架构来实现计算速度大幅提高的例证，这并不奇怪。本文提出了另一种新的结构——内积计算机。像ILLIAC IV一样，它是一个“特殊用途”处理器，旨在与通用计算机(即主机)一起使用。
{"title":"Applications of the inner product computer","authors":"E. Swartzlander","doi":"10.1145/800192.805688","DOIUrl":"https://doi.org/10.1145/800192.805688","url":null,"abstract":"Recently much interest has been expressed in the idea that future improvements in computer speed will be due primarily to architectural innovations as opposed to improvement in the characteristics of components (i.e., logic circuits, delays, memories, cycle times, etc.). In view of this it is not surprising that the current generation of “super computers” (i.e., the ILLIAC IV, the STAR 100, and the ASC) all exemplify the use of new architectures to achieve great increases in computing speeds.\u0000 In this paper yet another new architecture is proposed - the inner product computer4. Like the ILLIAC IV it is a “special purpose” processor which is intended to be used in conjunction with a general purpose (i.e., host) computer.","PeriodicalId":72321,"journal":{"name":"ASSETS. Annual ACM Conference on Assistive Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1973-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82394430","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}
In this paper, the shortcomings of Backus Naur specification of the syntactic properties of programming languages are investigated and a method for the specification of context-sensitive properties is suggested. Based on the notation of the tree structures of the Vienna Definition Language [Lu 1], samples of descriptions of context-sensitive grammars are presented as sets of conditionals which operate over the derivation trees of context-free specifications in BNF grammars to eliminate the extra-lingual features. The method is also extended to provide a syntactic specification of the default attributes of a language by the description of modifications which are to be made to the parsed form (syntactic tree) of instances of the language. For the purposes of example, a mini-language (ML 5/2) is presented. This paper exemplifies the problems of parameter passing and provides examples of the context-sensitive conditions of matching procedure calls and their declarations as well as matching parameters and their corresponding arguments.
{"title":"Conditional syntactic specification","authors":"John A. N. Lee, J. Dorocak","doi":"10.1145/800192.805689","DOIUrl":"https://doi.org/10.1145/800192.805689","url":null,"abstract":"In this paper, the shortcomings of Backus Naur specification of the syntactic properties of programming languages are investigated and a method for the specification of context-sensitive properties is suggested. Based on the notation of the tree structures of the Vienna Definition Language [Lu 1], samples of descriptions of context-sensitive grammars are presented as sets of conditionals which operate over the derivation trees of context-free specifications in BNF grammars to eliminate the extra-lingual features. The method is also extended to provide a syntactic specification of the default attributes of a language by the description of modifications which are to be made to the parsed form (syntactic tree) of instances of the language. For the purposes of example, a mini-language (ML 5/2) is presented. This paper exemplifies the problems of parameter passing and provides examples of the context-sensitive conditions of matching procedure calls and their declarations as well as matching parameters and their corresponding arguments.","PeriodicalId":72321,"journal":{"name":"ASSETS. Annual ACM Conference on Assistive Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1973-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89520897","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}
Variational methods of approximation have become very popular in recent years among engineers and numerical analysts. In particular, the finite element method has established itself as one of the most powerful techniques available for the approximate solution of boundary-value problems. In the present paper, we outline a number of mathematical properties of the method which are partially responsible for its success; we discuss certain error estimates and convergence results, and we describe some results obtained in applications of the method to a class of nonlinear problems in elastodynamics.
{"title":"Some distributional and convergence properties of the finite element method, with applications in nonlinear elastodynamics","authors":"J. Oden","doi":"10.1145/800192.805746","DOIUrl":"https://doi.org/10.1145/800192.805746","url":null,"abstract":"Variational methods of approximation have become very popular in recent years among engineers and numerical analysts. In particular, the finite element method has established itself as one of the most powerful techniques available for the approximate solution of boundary-value problems. In the present paper, we outline a number of mathematical properties of the method which are partially responsible for its success; we discuss certain error estimates and convergence results, and we describe some results obtained in applications of the method to a class of nonlinear problems in elastodynamics.","PeriodicalId":72321,"journal":{"name":"ASSETS. Annual ACM Conference on Assistive Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1973-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81078262","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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