Showing papers on "String (computer science) published in 1969"

Integer Programming and the Theory of Grouping

Abstract: This paper is written with three objectives in mind. First, to point out that the problem of grouping, where a larger number of elements n are combined into m mutually exclusive groups (m < n) should be recognized as a problem in Integer Programming, and that such recognition can help us in avoiding complete enumeration of stages in grouping from n to n — 1 … to m, and of alternative possibilities in each stage. Second, to formulate mathematically some simple versions of the relevant Integer Programming Problem, so that the available computer codes can solve it. When the grouping attempts to minimize the within groups sums of squares, the so-called string property is proved to be necessary for the minimum (Lemma 1). It is shown that the string property can be exploited to write the non-linear within group sums of squares as a linear function (Lemma 2). An attempt is made to generalize the string property for the higher dimensional case. Third, to give some numerical examples to clarify the mathem...

Probabilistic representation of formal languages

Abstract: The problem of assigning a probability to each string of a language L(G) generated by a grammar G is considered Two methods are considered One method assigns a probability to each production associated with G and the other assigns the probabilities on the basis of particular features of the language Several necessary conditions that must be satisfied by these probability assignment techniques if they are to be consistant are presented The problem of recognizing languages is also considered It is shown that under some conditions it is possible to recognize a non finitestate language with a finite state acceptor if one is willing to accept a small probability of making an error

Well tool for use in a tubular string

Abstract: A WELL TOOL INCORPORATING A REINFORCED INFLATABLE ELEMENT WHICH IS CARRIED BY THE DRILL STRING IN THE WELL BORE AND REMAINS DEFLATED DURING ROTARY DRILLING OPERATIONS WHICH CAN BE INFLATED TO SEAL OFF THE WELL BORE TO ENABLE VARIOUS OPERATIONS TO BE PERFORMED IN THE WELL BORE AND THE ELEMENT THEREAFTER DEFLATED AND ROTARY DRILLING OPERATIONS RESUMED. THIS OPERATION MAY BE REPEATED AS OFTEN AS DESIRED.

A companded one-bit coder for television transmission

Abstract: We compand a one-bit coder by increasing its step size when a string of equal bits is detected in the transmitted code. To code and decode each string we use a weight sequence 1, 1, 2, 3, 5… 5, the weight returns to unity when the string ends. Stability considerations restrict the choice of weights but those proposed give adequate stability as well as improve the signal-to-noise ratio about 5 dB. The weighted coder has a wide tolerance to changes of input, so that a ±3 dB change from the design value is hardly visible to most observers. Matching weights at the transmitter and receiver is uncritical because mismatches appear as small changes of contrast rather than as noise. The circuit is easily implemented because it is tolerant to changes of component values. There is a description of an experimental coder and decoder, together with subjective and objective measures of performance. Signal-to-noise ratios of 50 dB are reported.

Data compression and decompression system

Abstract: A high speed, multistage, compressor-decompressor system for processing arbitrary bit strings by reversibly removing redundant information. Alphanumeric information is processed by Type 1 compression which involves removing patterns of contiguous bytes and replacing each removed pattern by decompression information which takes considerably less storage space, and Type 2 compression which involves removing individual redundant bytes and constructing a bit map identifying the location of the removed bytes. Numerical information is processed by a compression technique involving truncation, recursive differencing, sequence removal, packing, and then utilizing the Type 1 and Type 2 compression which are used in conjunction with alphanumeric information. The information which is to be compressed is arranged in strings of bytes and any information defining removal of redundant information from a string is kept together with the string. As a result, each string is selfdefined in the sense that it contains all information needed to decompress that string.

Anchor assembly for well tools such as packers and the like

Abstract: An anchor assembly for anchoring well tools such as packers and the like, inside a pipe string adapted particularly for running on a wore line tool string. The assembly includes safety latch means arranged to provide assurance against premature or accidental release of the assembly from the running string while being run but which is readily releasable upon actuation of the anchor elements.

Tuning mechanism for a stringed musical instrument

Abstract: A musical instrument having multiple vibrating string segments, each segment forming a part of a continuous string assembly whereby the tension of each vibrating string segment can be adjusted for tuning purposes with a single tension adjustment of the complete assembly, wherein the string segments are in a state of stress with the magnitudes of the stresses being mutually related to each other with a predetermined ratio.

Recognition of handwritten numerals using decision graph

Abstract: An optical character reader capable of reading handwritten numerical characters has been developed and applied to mail automation. The recognition of characters is performed by extracting geometrical features out of horizontally divided zones together with their mutual connective relation. The topological structure of character strokes is analyzed by a sequential machine with an input string of stroke segments combined with information on the connective relation. The extracted features are sequentially matched with standard references. A new decision method called decision graph matching is fully utilized. The decision graph consists of a set of decision transition diagrams to be compared with the string of extracted features and a penalty count system to detect the optimum match. High flexibility against unlimited variability of handwritten character shapes is achieved by means of a stored logic system using rewritable magnetic core memory.

The description of data structures for statistical computing

Abstract: Publisher Summary A major part of most large-scale analyses of data on a computer is concerned with: (1) specifying the external arrangement of the data with their associated labels and headings, (2) specifying the internal core storage for the same data, and (3) describing how one arrangement is to be mapped into the other. By contrast, the internal manipulation of data is often much simpler. Some of the difficulties arise because the core store is essentially a one-dimensional string of locations, whereas data on paper are displayed in two dimensions and the effects of this persist even when the data are punched on paper tape, line by line. Other difficulties arise because efficient processing demands internal storage in vectors of homogeneous mode, for example, all of whose components are integer, or all real, whereas for display purposes, it is convenient to intersperse data values with labels, and sub-headings, so that consecutive items have different modes.

Variable topology random access memory organizations

Abstract: One of the most basic of all computer operations is the actual or virtual construction of a data sequence to be used either as the operand for a simple data transfer, or as the argument of a functional transformation. In a significant number of practical situations, the data from which the string is to be constructed are physically scattered prior to the proposed operation or must be scattered after the operation due to physical space limitations or for reasons dictated by the logical structuring requirements of the application.

Pattern recognition using an associative store

Abstract: Graphical patterns, such as characters, are represented by sets of binary symmetric numbers (1, - 1). An associative store holds a first table of numbers (1, 0, - 1) organized into words representing the coefficients of hyperplanes for dividing a pattern space into volumes such that points in the same volume belong to the same pattern class. Each hyperplane representation is contained in a pair of words holding respectively the true and complemented forms of the hyperplane coefficients. A first associative table look-up determines which word of each pair more closely matches a particular pattern number set, by using the number set as a search argument. The resulting binary number string, indicative of a particular volume in the pattern space, is then used as a search argument for a second table in the store. The second table is organized into words representing each individual volume and the name of the pattern associated with that volume. An exact match on the second table look-up thus produces an output indicative of the name of the pattern to be recognized.

The Classification of Constrained Data

Abstract: The effects of constraints-external conditions imposed on but not inherent in the dataare subtle, and they are as yet insufficiently understood. In line constraint arises when the character states of each Operational Taxonomical Unit are made to add up to some constant, as might be the case with percentage data. A simple transform is indicated. Cross constraint on a classification of OTUs would arise as a result of operations like row standardization. It shows up as a tendency for correlations to go negative, and such standardizations are best avoided if possible. Numerical taxonomic techniques seem to be engaged not in classifying things, but in analysing strings of numbers, and in a certain sense are numerical models of the things. To make inferences, about the things from analysis of the numbers, we must be sure then that our model is both sufficient, at least for the purposes we have set our classification, and also either undistorted, or, at least, distorted in a way we understand. Types of distortion introduced into the model by the process of measurement, or in the preparation of the data, but at any rate external to the thing, may be called constraints. Two types are examined in this paper, and both are named according to, their relation to, the data strings: In-line constraint arises when the elements of each string are forced to add up to some constant value. Cross constraint obtains when the sum of corresponding elements from each string is required to be a constant. Ordinarily, in numerical taxonomy, each Operational Taxonomical Unit (OTU) is modelled by a string of numbers arranged in a column, each character by a row. If the characters have been standardized, row sums are constant, and this is cross constraint on the relation between OTUs. But if R-type analysis of the relations between rows was of interest, the data strings would be the rows, each of which would be in-line constrained after row standardization. A chemical analysis represents a case of constraint which is inherent in the data. The sum of constituents in each sample must be 100%, so that samples are in-line constrained, and the relation between constituents is cross constrained. Other types of distortion, for example the partial logical correlations of Sokal and Sneath (1963), may also exist in the model, and may for taxonomic work be more important. But in two cases that drew my attention to constraints, namely the problem of discriminating explosions from earthquakes biy multivariate analysis of the information on the seismogram, and the problem of classifying rock samples by their chemical constitution, the effects of constraint have proved to be both subtle and far reaching. They should always be considered in assessing the reliability of a classification, and because constraint enters at the earliest stage, the effects will be felt in every method of multivariate analysis. IN-LINE CONSTRAINT AND THE

An Embodiment of Some Vertebrate Command and Control Principles

Abstract: Reticular formation of central nervous system in vertebrates described as behavior controlling circuit of interconnected modules, proposing hybrid computer method for operational scheme

Methods and apparatus for securing together sticks in bundles

Abstract: A method and an apparatus by which sticks are secured together in bundles with the aid of a string which is placed in a recess formed in the stick ends. After the string has been placed in the recess the stick ends are deformed adjacent the recess to anchor the string therein. A continuous string can be used, whereby the bundles are mutually connected to each other.