Search

Using direct access computer files of bibliographic information, an attempt is made to overcome one of the problems often associated with information retrieval, namely, the maintenance and use of large dictionaries, the greater part of which is used only infrequently. A novel method is presented, which maps the hyperbolic frequency distribution of text characteristics onto a rectangular distribution. This is more suited to implementation on storage devices. This method treats text as a string of characters rather than words bounded by spaces, and chooses subsets of strings such that their frequencies of occurrence are more even than those of word types. The members of this subset are then used as index keys for retrieval. The rectangular distribution of key frequencies results in a much simplified file organization and promises considerable cost advantages. [ABSTRACT FROM AUTHOR]

Develops a heuristic algorithm that converts a limited entry decision table to a tree structured computer program with near minimum average processing time. Use of the information theory; Advantages over previous similar algorithms; Applicability for manual conversion of decision tables to flowcharts.

This paper modifies an earlier algorithm for converting decision tables into flowcharts which minimize subsequent execution time when compiled into a computer program. The algorithms considered in this paper perform limited search and, accordingly, do not necessarily result in globally optimal solutions. However, the greater search effort needed to obtain a globally optimal solution for complex decision tables is usually not justified by sufficient savings in execution time. There is an analogy between the problem of converting decision tables into efficient flowcharts and the well-understood problem in information theory of noiseless coding. The results of the noiseless coding literature are used to explore the limitations of algorithms used to solve the decision table problem. The analogy between the two problems is also used to develop improvements to the information algorithm in extending the depth of search under certain conditions and in proposing additional conditions to be added to the decision table. Finally, the information algorithm is compared with an algorithm proposed in a recent paper by Verhelst. [ABSTRACT FROM AUTHOR]

Following the fixpoint theory of Scott, the semantics of computer programs are defined in terms of the least fixpoints of recursive programs. This allows not only the justification of all existing verification techniques, but also their extension to the handling, in a uniform manner of various properties of computer programs, including correctness, termination, and equivalence. [ABSTRACT FROM AUTHOR]

It is often desirable to convert verbal responses to multidigit codes. This conversion is generally accomplished by clerk-coders. A study was conducted to test the feasibility of translating verbal descriptions to numerical codes in a computer program. Primary emphasis was placed on computerized construction of a reference file of verbal descriptions for use by the program. The results of the study clearly show that such procedures are feasible. [ABSTRACT FROM AUTHOR]

Pollack has proposed on algorithm for converting decision tables into flowcharts which minimize subsequent execution time when compiled into a computer program. Two modifications a this algorithm are proposed. The first relies on Shannon's noiseless coding theorem and the communications concept of entropy but does not completely test the ELSE Rule. The second modification completely tests the ELSE Rule but results in more executions than the first modification. Both modifications result in lower execution time than Pollack's algorithm. However, neither modification guarantees a globally optimal solution. [ABSTRACT FROM AUTHOR]

Although automatic syntactic and semantic analysis is not yet possible for all of an unrestricted natural language text, some applications, of which content analysis is one, do not have such a stringent coverage requirement. Preliminary studies show that the Harvard Syntactic Analyzer can produce correct and unambiguous identification of the subject and object of certain verbs for approximately half of the relevant occurrences. This provides a degree of coverage for content analysis variables which compares favorably to manual methods, in which only a sample of the total available text is normally processed. [ABSTRACT FROM AUTHOR]

Focuses on proposed American Standard Code for Information Interchange that provides coded representations for a set of graphic and control characters having general utility in information interchange. Inclusion of several special characters intended to facilitate the representation of additional symbols or functions, a process known as code extension; Minimization of the risk of conflict between systems required to interoperate, and the possibility of including advance provision for code extension in the design of general purpose data handling systems; Establishment of a set of procedures for the representation of graphic symbols or control functions.

This paper describes how some of the semantics of ALGOL 60 can be formalized by establishing a correspondence between expressions of ALGOL 60 and expressions in a modified form of Church's λ-notation. First a model for computer languages and computer behavior is described, based on the notions of functional application and functional abstraction, but also having analogues for imperative language features. Then this model is used as an "abstract object language" into which ALGOL 60 is mapped. Many of ALGOL 60's features emerge as particular arrangements of a small number of structural rules, suggesting new classifications and generalizations. The correspondence is first described informally, mainly by illustrations. The second part of the paper gives a formal description, i.e. an "abstract compiler" into the "abstract object language." This is itself presented in a "purely functional" notation, that is one using only application and abstraction. [ABSTRACT FROM AUTHOR]

The article discusses an algorithm for Hu-Tucker minimum redundancy alphabetic coding method. This algorithm implements the Hu-Tucker method of variable length minimum redundancy alphabetic binary encoding. The symbols of the alphabet are considered to be an ordered forest of n terminal nodes. Two nodes in an ordered forest are said to be tentative-connecting if the sequence of nodes between the two given nodes is either empty or consists entirely of nonterminal nodes. An interval of nodes each pair of which is a tentative-connecting pair is called a tentative-connecting string. The original forest will, after a finite number of steps, be connected into a single tree. This tree will not, in general, satisfy the order-preserving requirement. However, it is shown the path lengths are feasible for the construction of a tree which does satisfy this requirement and is, moreover, minimal in cost. The present procedure finds a minimal cost tree whose longest path length and total path length are minimal.

This article presents information on the forthcoming events related to the computing machinery. The 1967 International Symposium on Information Theory," is going to be held from September 6-8 in Athens, Greece. The 22nd Annual Instrument Society of America (ISA) Conference and Exhibit is going to be held September 11-14 in Chicago, Illinois. The Symposium on Computer Control of Natural Resources and Public Utilities is going to be held from September 11-14 in Israel. The 5th International Cybernetics Congress is going to be held from September 11-15 in Belgium. The Joint Conference of Univac Users Association and Univac Scientific Exchange is going to be held from September 19-22 in Minneapolis.

The article presents a report by the National Academy of Sciences that examines machine translation against the light of human translation, which has disturbed many research administrators in the government. So much bad publicity has been engendered by this report that the future of machine translation is uncertain, even though the technology is a scant twelve years old. The report, titled "Language and Machines," recommends that the government withdraw its support of machine translation in favor of more theoretical areas, such as computational linguistics. "Languages and Machines" was written after a two-year study by the Automatic Language Processing Advisory Committee. Much bitter debate followed its public release in November 1966. On January 24, two months after the report was released a group of research administrators met in Washington to compare notes on the effects of the report. The administration argues that machine translation is going on in five facilities around the world. On the basis of studies it has been concluded that the post-edited machine translations of FTD were slow, expensive, of poor graphic arts quality, and not very good translation.

The article offers information on the ECMA standard in representation of the Standard ECMA 7-Bit Code in Punched Cards. The relative advantages and disadvantages of employing a decimal or binary code representation are also discussed. Most of the binary coded decimal punched cards are incompatible with the standards of the ECMA 6 and 7-Bit codes in punched cards. On the other hand, decimal system representation was found to be in consonance with the desired results and closer to the minimum ECMA standards for punched cards. The structure of both the systems and its application have been discussed as well as graphically represented.

The article focuses on developments related to data transmission systems in Great Britain. British communications services are intended to remain under the firm control of GPO, the Great Britain Post Office. GPO control of data transmission has raised the fear that a nationwide network will not materialize if data transmission services continue to be provided at the present slow rate. Underlying much of the GPO's need for gradualism is the limited capacity of the national telephone network. This network, which is used by at least two thirds of installed terminals, was originally designed to accommodate vocal messages averaging three minutes in length. This time period has served as a standard in determining future investments in equipment. However, the average duration of a single computer/teletype interexchange is 25 minutes. Thus, the operation of a single computer linked to 80 terminals going through the same switchboard would be the equivalent of 600 to 700 voice communications. The British telephone network's capabilities are being increased to serve the expansion of data traffic.

The article focuses on the formation of the Association for Computing Machinery's (ACM) Special Interest Committee on Language Analysis and Studies in the Humanities (SICLASH). In recognition of the need for closer rapport among scholars and scientists engaged in computer-aided language analysis, computer-aided humanistic studies, and the development of software and hardware for such research, the Association for Computing Machinery has chartered the SICLASH. The goals of the Committee are to provide a focus within the ACM for a broad spectrum of computer-aided language studies. Various professional organizations have relevant interests in particular aspects of such research, but there is no single organization permitting people from disparate applications groups to share information and research on common problems in computer-based language analysis. It also provides a focus within the ACM for those humanists within the fine arts, such as music and graphic arts, who have need of computer technology, as well as for the majority of Humanists concerned with the written and spoken language.