Showing papers on "Concatenation published in 1983"

Concatenation hierarchies decidability results and problems

Abstract: Let A be a finite alphabet. The well-known Kleene's theorem states that a language L of A* is rational iff its syntactic monoid is finite. Schutzenberger's theorem states that a language L is star-free iff its syntactic monoid is group-free. It turns out that many subfamilies of the rational languages can be characterized in this way by properties of their syntactic monoids or semigroups. This paper gives a survey of the various hierarchies of star-free languages, their descriptions in terms of semigroups, and the related decidability results and problems.

An Algorithmic Interpretation of the GKS TEXT Primitive

Abstract: The specification of text output is one of the most complex parts of the GKS standard [1]. The text “geometry” is determined by a wide variety of factors: some, such as character height, are specified directly by the user; others, such as the aspect ratio of a character in a given font, are characteristic of a particular implementation. The GKS document gives a detailed, but informal, description of the way in which these various factors combine to determine the text size and position. The purpose of this paper is to put forward a more formal description of the GKS text geometry: an algorithm is presented that calculates the size and positions of individual character bodies for any text string, under any setting of text attributes, together with the text extent rectangle and concatenation point; a realization of the algorithm as a FORTRAN 77 subroutine is also given. It is hoped that the algorithm will help implementos to interpret the GKS standard more easily.

Japanese syllabary to chinese character conversion system using probability matrix

Abstract: PURPOSE:To express information of word-to-word concatenation in details and to perform high-level KANA(Japanese syllabary)-KANJI(Chinese character) conversion, by providing a probability information holding means for indicating the probability of concatenation between words and extracting a specific word on the basis of the probability of the concatenation between words obtained from said means. CONSTITUTION:A possible word extracting device 6 extracts words, one by one, from a possible word stack 5 and sets them in a possible word extraction buffer 7. Consequently, a possibility retrieving device 8 accesses a concatenation possibility matrix 9 on the basis of the part of speech of a word set in a last-word buffer 2 and that in said buffer 7 to set the concatenation possibility in a possibility buffer 10. An evaluated-value arithmetic device 11, on the other hand, sets the evaluated value of the word in an evaluated-value buffer 12 on the basis of data set in the possible-word extraction buffer 7. A multiplication part 13 multiplies the value set in the possibility buffer 10 by that in the evaluated- value buffer 12 and sets the product in a priority buffer 14.

Erroneous character detection and correction backing device

Abstract: PURPOSE:To automatically execute the work for detecting and correcting an error, and to elevate the efficiency of a device, by detecting an example of an erroneous character from whether characters of a character string of a Japanese sentence can be connected or not, and outputting a character which can be connected to the previous or the following character of that which is similar to said example, as an example of a corrected character. CONSTITUTION:In a character string of a Japanese sentence from an input part 1, 2 or more characters which are connected to each other are stored temporarily in a register 2, and the 2 character portion stored in the register 2 is stored in a buffer 3a of a control part 3. Also, in a character concatenation dictionary 5, contents as to whether 2 characters connected to each other, of a Japanese sentence can be concatenated or not are stored, the contents of the buffer 3a are collated with the contents of the dictionary 5 by a collating circuit 4, and they are provided to the control part 3. By a result of this collation, an erroneous code generating circuit 7-1, an example start code generating circuit 7-2 and an example end code generating circuit 7-3, of a code generating circuit 7 are driven. Subsequently, a character which can be connected to the previous or the following character of that which is similar to the erroneous character example is outputted as a corrected character to an output part 6, the work for detecting and correcting an error is executed automatically, and the effect of a device is elevated.

Concatenation Phenomena in Multimode Fibers

Abstract: Many experimental results have shown that the behavior of a link, which consists of a sequence of multimode fibers, can not be calculated in a straightforward deterministic way from the knowledge of the so-called base-band power transfer function of the individual fibers.

Noise elimination system of character reader

Abstract: PURPOSE:To discriminate between an entered noise and an effective stroke accurately by a simple procedure by deciding on the significance of an objective stroke which crosses a side of an observation frame and does not reach a noise depth decision frame on the basis of the inclination of the objective stroke. CONSTITUTION:A character pattern is stored in a figure memory 3, and concatenation components of the read character are extracted on the basis of the stored information in the figure memory 3 through the operation of a concatenation component extracting circuit 4 and a central processor 5 and stored in a concatenation component memory 7. The central processor 5 reads coordinate information on black bit constituting one concatenation component out of the concatenation component table in the memory 7 to discriminate whether the stroke contacts one side of the observation frame. Namely, the observation frame of the character to be read and the noise depth decision frame provided inside of the observation frame are used to decide on the significance of the objective stroke.

Algebraic Codes Achieving the Capacity of the Binary Symmetric Channel

Abstract: Based on Justesen's idea of variable concatenation, an algebraic construction is given of a family of easily decodable binary linear codes achieving the capacity of the binary symmetric channel. The probability of erroneous decoding is shown to tend exponentially to zero when the block length tends to infinity, for any encoding rate less than the capacity.