ACM-SE 28最新文献

{"title":"The design and implementation of the network backup control language","authors":"John C. Orthoefer","doi":"10.1145/98949.99158","DOIUrl":"https://doi.org/10.1145/98949.99158","url":null,"abstract":"Dumper is the implementation of a language to sim­ plify the process of doing backups on a networked com­ puter system. The language, called Network Backup Con­ trol Language (NBCL), permits the user to relate UNIXt mount points to backup devices, on a single TCP/IP net­ work, and executes these relations on specified days. With backup schedules put forth in a formal language, regular backups can be done efficiently and completely.","PeriodicalId":409883,"journal":{"name":"ACM-SE 28","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133615251","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":"Investigation of a gambling approach to the subjective entropy test","authors":"Joel B. Davis","doi":"10.1145/98949.99133","DOIUrl":"https://doi.org/10.1145/98949.99133","url":null,"abstract":"Researchers currently arc investigating a number of possible practical solutions for the problem of measuring program comprehension on a pragmatic level. Two well known tests arc the comprehension test and the Cloze lest [1], Perhaps less well known is the Subjective Entropy Test (SET) proposed by Zunde [2], This paper describes an investigation into a new version of SET called SETBET. We wished lo determine whether adding a betting scheme to the SET would change its performance. The conventional comprehension lest is probably the most intuitive of the tests. Such tests generally ask the subject to \"play computer\". For example, he is given a program and asked to determine what it does, or he is given a program containing a bug and asked to correct it. However, the problems with the comprehension test are that it is very time consuming lo prepare and that it re­ quires subjective grading. Because of these problems, other tests, such as the Cloze test, have been investigated. The Cloze lest consists of filling in missing parts in a program for which the respondent has to supply the correct word. One advantage of the Cloze lest over the comprchensi n type test is that the Cloze tests are simpler lo pre­ pare. Another advantage is grading, which can be totally objective if exact answers are required, or it can be some­ what more subjective if elements such as variable names can be changed. A problem with the Cloze test is that it is sensitive to bias and to the stimulus materials [3] and |1], Problems associated with this test motivated more re­ search. One result of the new research by Zunde [2] is a lest called SET.","PeriodicalId":409883,"journal":{"name":"ACM-SE 28","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127241870","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 science: a philosophical primer","authors":"G. J. Johnson","doi":"10.1145/98949.98985","DOIUrl":"https://doi.org/10.1145/98949.98985","url":null,"abstract":"Since 1982 I have been an instructor of computer science at the undergraduate and graduate levels. My academic background outside of computer science includes graduate degrees in literary studies, as well as an undergraduate degree in philosophy. I bring to computer science the perspective of one who is practiced in the analysis of writing styles and thought patterns. From iny first exposure to computers I was fascinated by the way computer professionals write and talk, enthralled by the concepts they use, intrigued by the cosmos that they fabricate and inhabit. Although I am now an insider, I continue to be an observer, a philosopher of computer science.","PeriodicalId":409883,"journal":{"name":"ACM-SE 28","volume":"5 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117036719","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":"Improving the Smalltalk Browser: a case study in Smalltalk development","authors":"Jeffrey L. Hieb","doi":"10.1145/98949.99129","DOIUrl":"https://doi.org/10.1145/98949.99129","url":null,"abstract":"With the advancements being made in computers today, object oriented language environments are fast becoming a reality for more and more people. One of the more widely accepted and used object oriented environments is Smalltalk. This system was used along with C and Ada for a study of possible ways to introduce students to object oriented programming. After developing several implementations in Smalltalk, its advantages become quite clear. However the point here is not to discuss the advantages of Smalltalk, but to talk about some areas of improvement, which were discovered while using the system. However as with any new system there are always areas for improvement, and that is what we wish to discuss here. There are many areas for improvement, but the area of our chief concern is the Browser, or the Class Hierarchy Browser. As a result of other research I was inspired to attempt to improve the Browser, and at least point out its deficiency. Since the main goal of the research was introduction to object oriented programming, this paper discussing the development of the new Browser will serve not only as documentation but also as an example of implementations in Smalltalk. The first part discusses some of the observations and deficiencies that were observed when using the Smalltalk system. Later sections document and discuss the improvements that were implemented. This paper assumes that the reader has seen some Smalltalk previously; however, if the reader has not seen any Smalltalk, many of the general concepts will be accessible. Two points are important: first, Smalltalk is written almost entirely in Smalltalk.; second, any \"programs\" or code which aré written using Smalltalk modify the system itself. Therefore, no two systems are the same, except when they are first installed. If this seems difficult, consider some more common languages such as C and Pascal. These systems compile the program or code. Then die source code and the object code are set aside, separate from the language or compiler. But in Smalltalk everything you do is part of the system. So if you write a new \"program\" it becomes part of the system, that is its “code” is available to any other elements of the system.","PeriodicalId":409883,"journal":{"name":"ACM-SE 28","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131307015","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 languages, OOP, and C++","authors":"Roger E. Lessman","doi":"10.1145/98949.98981","DOIUrl":"https://doi.org/10.1145/98949.98981","url":null,"abstract":"The traditional core course entitled Programming Lan­ guage» is a nnturnl setting for the study of the currentlypopular programming paradigms. Within this course, it is also necessary and convenient to introduce stu­ dents to the design, specification, and implementation of programming languages and to emphasise the run-time features of high-level languages. A project is outlined which utilises the procedural/imperative paradigm to implement an interpreter for a small block-structured language. The project is enhanced to utilise data ab­ straction and object-oriented programming in C ++ to provide a contemporary implementation of the original interpreter. I n t r o d u c t i o n In Curriculum '78, Austing, el al., describe the core course CS8 Organization of Programming Languages. Objectives of CSS are 1. to introduce the formal study of programming lan­ guage specification and analysis; 2. to develop an understanding of the organisation of programming languages, especially the run-lime behavior; and 3. to continue the development of problem solution and programming skills [1], In an effort to meet the first two objectives, instruc­ tors of CSS have historically presented exposition on • formal language specification and its applications; • interpretation vs. compilation; Permission to copy without fee all or pari of this material is granted provided that lire copies are not made or distributed for direct com­ mercial advantage, the ACM copyright notice and the title of the publication and its date appear, and notice is given that copying is by permission of the Association for Computing Machinery. To copy otherwise, or to republish, requires a fee and/or specific per­ mission. © 1990 ACM 0-89791-356-6/90/0400/0063 $1.50 • the run-time aspects of data types, data objects, and control structures; and • lexical analysis and parsing. Traditional texts have approached the third objective with an intensive study of language features as imple­ mented in several procedural and block-structured lan­ guages and in a functional programming language such as LISP [2J. In the Partial Draft Report of the ACM/IEEE Joint Curriculum Task Force, Tucker, et. al., itemise a num­ ber of PL modules which contain material covered in the traditional course for CSS [3]. In addition to the top­ ics listed earlier, these modules emphasise the following contemporary programming paradigms:","PeriodicalId":409883,"journal":{"name":"ACM-SE 28","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127012193","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 mirage problem in digital halftone resolution","authors":"V. E. Rao","doi":"10.1145/98949.99115","DOIUrl":"https://doi.org/10.1145/98949.99115","url":null,"abstract":"Generating realistic images is a challenging problem in computer graphics. The last stage of many graphic tasks is the production of a continuous tone picture often on a bilevel display. As a result, an algorithm to map continuous tone intensity data to bilevel data is required. This paper examines the ordered dither and Knuth's dot diffusion algorithms and constructs a mi­ rage for both these techniques, that is, an image which is recognizable under a special display technique but which vanishes completely when displayed using either ordered dither or dot diffusion. Finally, we conclude that there is still more work that could be done in the field of reproducing halftone images.","PeriodicalId":409883,"journal":{"name":"ACM-SE 28","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125019877","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 context sensitive tabular parsing algorithm","authors":"F. Hadlock","doi":"10.1145/98949.99012","DOIUrl":"https://doi.org/10.1145/98949.99012","url":null,"abstract":"Tlie parsing algorithm due to Younger is applica­ ble to any context free language but requires that the grammar be in Chomsky normal form. Resides es­ tablishing an 0 (n'*) upper bound to time complex­ ity needed to parse context free languages, Younger’s algorithm has the advantages that it docs not re­ quire the grammar to be unambiguous and that it degrades gracefully while parsing \"ungrammatical” strings. These are advantages desirable in processing nnlurnl language, if not coupled with the restriction that the grammar be in Chomsky normal form. In this article, a general tabular algorithm is de­ veloped which uses the tabular structure employed by Younger’s algorithm. Instead of nonterminal charac­ ters (or syntactic types) as table entries, a construct is used which is similar to the LR(0) items employed by Knulh’s LR(k) parsing algorithm, and by the Gra­ ham, Harrison, R u e e o algorithm. Graham, Harrison and Russo use these items as table entries, obviating the need to employ Chomsky normal form. The algo­ rithm presented in this article employs such items for not only the replacement phrase, but also the left and right context strings in context sensitive rules. The resulting algorithm is applicable to context sensitive grammars without erasure rules and is suitable as a platform for semantic case frame analysis of natural","PeriodicalId":409883,"journal":{"name":"ACM-SE 28","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125349257","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":"Some suggestions for implementing closed laboratories in CS1","authors":"Ken R. Little","doi":"10.1145/98949.98993","DOIUrl":"https://doi.org/10.1145/98949.98993","url":null,"abstract":"The ACM Task Force on the Core of Computer Science has recently proposed a computer science teaching paradigm conforming to traditional scientific standards. Such a paradigm implies that an undergraduate curriculum in computing should ideally be composed of an integrated program of lectures and laboratory experiences. There arc two distinct types of computing laboratory experiences -often referred to as open and closed laboratories. In this paper, some general suggestions and guidelines concerning the construction of coupled elosed/open laboratories for the CS1 course arc given. An outline of a coupled elosed/open laboratory designed using the suggested guidelines is presented.","PeriodicalId":409883,"journal":{"name":"ACM-SE 28","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125405216","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 limited survey of the effects of single parametric variation on the GENEtic search implementation system (GENESIS) package","authors":"C. N. Lapena, W. Potter","doi":"10.1145/98949.99037","DOIUrl":"https://doi.org/10.1145/98949.99037","url":null,"abstract":"The genetic algorithm is a heuristic that can be used effectively in the optimization of functions. Briefly, the algorithm selects good solutions out of a set as determined by an objective function. This set of solutions tends towards the optimal value of the objective functionmuch like natural selection where a population of strong animals lend to survive more than a population of weak animals. GENESIS is a public domain package authored by John Grefenstetle and released by the Navy Center for Research in Applied Artificial Intelligence. In this paper, we implement this package on the maximization of a function similar to that defined in Peng & Reggia 1987 (I and II) for optimal covering of symptom-diagnosis sets. We vary some chosen parameters of GENESIS one-at-a-lime to get a feel for the parameter's effect on the overall performance of the algorithm on this problem. Although this survey is by no means complete, we feel that this information may be useful in serving as guidelines, for anyone who wishes to implement the genetic algorithm on any problem. The parameters that we vary are: number of trials, population size, crossover rale, mutation probability, and the seed that is used by the random number generator. We present about 70 variations in these parameters for each of our 9 different experiments. Our control data were derived from an exhaustive search of the solution space. In our first set of variations, we attempted to find the relationship between the variation of each parameter and optimality in relatively small steps. Our second set of variations found the behavior of the data when these parameters were varied greatly. Through about 600 variation experiments (each containing 1024 solutions), we have found that the most influencial parameter for our problem, when varied singly, is the mutation rate. Through our wide-variation experiments we have also found the approximate settings where these parameters, when varied singly, will show decline in performance for our problem.","PeriodicalId":409883,"journal":{"name":"ACM-SE 28","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129066570","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":"Improving workplace literacy in Alabama—proposal for a telecommunications network","authors":"C. Sankar, Charles Snyder, Paramjit S. Kahai","doi":"10.1145/98949.98987","DOIUrl":"https://doi.org/10.1145/98949.98987","url":null,"abstract":"PROBLEM Thirteen percent of the population in the United States is functionally illiterate and many businesses are not able to operate successfully due to a lack of literate workers. In comparison to other regions of the country, the South has the highest proportion of functional illiterates and traditional educational schemes do not seem to improve the situation. A low level of literacy has been identified as a particular problem in the fields of banking, data processing, and telecommunications industry. OBJECTIVE OF PROPOSAL The objective of the proposed network is to improve the literacy rate/level of the workers in Alabama using computer and telecommunications technology. In particular, for the state of Alabama, we recommend developing application systems running on an ALabama Literacy TElecommunicetions Network (ALLTEN), that can connect workplaces having concentrations of semi-literate and illiterate workers to regional and central nodes (Universities). Using this network, knowledge transfer (via voice, data, and video) can take place between Universities and businesses with subject workers.----------------------------------Permission to copy without fee all or part of this material is granted provided that the copie« are not made or distributed for direct com­ mercial advantage, the ACM copyright notice and tire title of the publication and its date appear, and notice Is given that copying is by permission of tlte Association for Computing Machinery. To copy otherwise, or to republish, requires a fee and/or specific per­ mission. © 1990 ACM 0-P979I-356-G/90AV400/OIR1 $1.50 APPLICATIONS The application programs that are provided using this network are expected to help' workers learn survival skills, improve problem solving skills, improve organizational skills, and learn technical vocabulary. These important skills are needed by many adult workers in their Job environment. But, traditional adult educational programs are structured similar to elementary school programs, and do not address these needs. ALLTEN is expected to fill this gap since the applications supported by ALLTEN can be changed quickly depending on the response of the workers. The application programs of ALLTEN would be based on the software and workstations developed in programs such as ICON (developed by UNISYS) and PALS (developed by IBM). These vendor systems are being evaluated to identify the benefits they can provide to these students. New software may be developed during the project to fulfill the obj ectives. The ALLTEN network would be built using existing and new networks. New networks would be designed and leased to connect the central to the regional nodes. No longer should relative isolation from urban centers be an obstacle to obtaining needed help for these workers. Telecommunications could be used to overcome this isolation and thus, this project could significantly impact the standard of living and economic development of Alabama.","PeriodicalId":409883,"journal":{"name":"ACM-SE 28","volume":"112 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122155083","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}