String (computer science)

About: String (computer science) is a research topic. Over the lifetime, 19430 publications have been published within this topic receiving 333247 citations. The topic is also known as: str & s.

Experiments in text file compression

Abstract: A system for the compression of data files, viewed as strings of characters, is presented. The method is general, and applies equally well to English, to PL/I, or to digital data. The system consists of an encoder, an analysis program, and a decoder. Two algorithms for encoding a string differ slightly from earlier proposals. The analysis program attempts to find an optimal set of codes for representing substrings of the file. Four new algorithms for this operation are described and compared. Various parameters in the algorithms are optimized to obtain a high degree of compression for sample texts.

Online handwriting recognition for Tamil

Abstract: A system for online recognition of handwritten Tamil characters is presented. A handwritten character is constructed by executing a sequence of strokes. A structure- or shape-based representation of a stroke is used in which a stroke is represented as a string of shape features. Using this string representation, an unknown stroke is identified by comparing it with a database of strokes using a flexible string matching procedure. A full character is recognized by identifying all the component strokes. Character termination, is determined using a finite state automaton. Development of similar systems for other Indian scripts is outlined.

Underbalanced drill string deployment valve method and apparatus

Abstract: Apparatus and methods for a deployment valve used with an underbalanced drilling system to enhance the advantages of underbalanced drilling. The underbalanced drilling system may typically comprise elements such as a rotating blow out preventer and drilling recovery system. The deployment valve is positioned in a tubular string, such as casing, at a well bore depth at or preferably substantially below the string light point of the drilling string. When the drilling string is above the string light point then the upwardly acting forces on the drilling string become greater than downwardly acting forces such that the drilling string begins to accelerate upwardly. The deployment valve has a bore sufficiently large to allow passage of the drill bit therethrough in the open position. The deployment valve may be closed when the drill string is pulled within the casing as may be necessary to service the drill string after drilling into a reservoir having a reservoir pressure. To allow the drill string to be removed from the casing, the pressure produced by the formation can be bled off and the drill string removed for servicing. The drill string can then be reinserted, the pressure in the casing above the deployment valve applied to preferably equalize pressure above and below the valve and the drill string run into the hole for further drilling.

Search‐based software test data generation for string data using program‐specific search operators

Abstract: This paper presents a novel approach to automatic software test data generation, where the test data is intended to cover program branches which depend on string predicates such as string equality, string ordering and regular expression matching. A search-based approach is assumed and some potential search operators and corresponding evaluation functions are assembled. Their performance is assessed empirically by using them to generate test data for a number of test programs. A novel approach of using search operators based on programming language string operators and parameterized by string literals from the program under test is introduced. These operators are also assessed empirically in generating test data for the test programs and are shown to provide a significant increase in performance. Copyright © 2006 John Wiley & Sons, Ltd.