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.

Growing string method with interpolation and optimization in internal coordinates: Method and examples

Abstract: The growing string method (GSM) has proven especially useful for locating chemical reaction paths at low computational cost. While many string methods use Cartesian coordinates, these methods can be substantially improved by changes in the coordinate system used for interpolation and optimization steps. The quality of the interpolation scheme is especially important because it determines how close the initial path is to the optimized reaction path, and this strongly affects the rate of convergence. In this article, a detailed description of the generation of internal coordinates (ICs) suitable for use in GSM as reactive tangents and in string optimization is given. Convergence of reaction paths is smooth because the IC tangent and orthogonal directions are better representations of chemical bonding compared to Cartesian coordinates. This is not only important quantitatively for reducing computational cost but also allows reaction paths to be described with smoothly varying chemically relevant coordinates. Benchmark computations with challenging reactions are compared to previous versions of GSM and show significant speedups. Finally, a climbing image scheme is included to improve the quality of the transition state approximation, ensuring high reliability of the method.

Imitation without intentionality. Using string parsing to copy the organization of behaviour

Abstract: A theory of imitation is proposed, string parsing, which separates the copying of behavioural organization by observation from an understanding of the cause of its effectiveness. In string parsing, recurring patterns in the visible stream of behaviour are detected and used to build a statistical sketch of the underlying hierarchical structure. This statistical sketch may in turn aid the subsequent comprehension of cause and effect. Three cases of social learning of relatively complex skills are examined, as potential cases of imitation by string parsing. Understanding the basic requirements for successful string parsing helps to resolve the conflict between mainly negative reports of imitation in experiments and more positive evidence from natural conditions. Since string parsing does not depend on comprehension of the intentions of other agents or the everyday physics of objects, separate tests of these abilities are needed even in animals shown to learn by imitation.

A Simple and Systematic Approach to Assigning Denavit–Hartenberg Parameters

Abstract: This paper presents a simple and intuitive approach to determining the kinematic parameters of a serial-link robot in Denavit-Hartenberg (DH) notation Once a manipulator's kinematics is parameterized in this form, a large body of standard algorithms and code implementations for kinematics, dynamics, motion planning, and simulation are available The proposed method has two parts The first is the ldquowalk through,rdquo a simple procedure that creates a string of elementary translations and rotations, from the user-defined base coordinate to the end-effector The second step is an algebraic procedure to manipulate this string into a form that can be factorized as link transforms, which can be represented in standard or modified DH notation The method allows for an arbitrary base and end-effector coordinate system as well as an arbitrary zero joint angle pose The algebraic procedure is amenable to computer algebra manipulation and a Java program is available as supplementary downloadable material

System and technique for monitoring and managing the deployment of subsea equipment

Abstract: A system that is usable in a subsea well includes a tubular string that extends from a surface platform toward the sea floor. The string has an upper end and a lower remote end that is located closer to the sea floor than to the platform. At least one sensor of the system is located near the remote end of the string to monitor deployment of subsea equipment.