Component Approach (component + approach)

Distribution by Scientific Domains


Selected Abstracts


The CCA core specification in a distributed memory SPMD framework

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 5 2002
Benjamin A. Allan
Abstract We present an overview of the Common Component Architecture (CCA) core specification and CCAFFEINE, a Sandia National Laboratories framework implementation compliant with the draft specification. CCAFFEINE stands for CCA Fast Framework Example In Need of Everything; that is, CCAFFEINE is fast, lightweight, and it aims to provide every framework service by using external, portable components instead of integrating all services into a single, heavy framework core. By fast, we mean that the CCAFFEINE glue does not get between components in a way that slows down their interactions. We present the CCAFFEINE solutions to several fundamental problems in the application of component software approaches to the construction of single program multiple data (SPMD) applications. We demonstrate the integration of components from three organizations, two within Sandia and one at Oak Ridge National Laboratory. We outline some requirements for key enabling facilities needed for a successful component approach to SPMD application building. Copyright © 2002 John Wiley & Sons, Ltd. [source]


Students' experience of component versus integrated virtual learning environments

JOURNAL OF COMPUTER ASSISTED LEARNING, Issue 4 2005
M. Weller
Abstract The use of virtual learning environments (VLEs) has become increasingly common in most higher education (HE) institutions. Recent developments have proposed the interoperability of software systems and content, to create component VLEs in contrast with the integrated, monolithic ones that are currently prevalent. This paper examines the student experience of two VLEs, one integrated approach and the other component. In general, students preferred the component system, although this may have been influenced by other factors such as performance. Although the study is limited to one cohort of student it makes a number of suggestions relevant to anyone deploying a VLE. These are that the component approach is a viable one from a student perspective, the broader context in which the VLE operates is important in student perception and that poor system performance may have unpredictable consequences for the learning experience. [source]


Generation and forward displacement analysis of two new classes of analytic 6-SPS parallel manipulators

JOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 6 2001
Xianwen Kong
Analytic manipulators are manipulators with a characteristic polynomial of fourth degree or lower. Using the component approach to generate analytic 6-SPS parallel manipulators (PMs), the generation process is reduced to the generation of analytic components for 6-SPS PMs. Two new classes of analytic components for 6-SPS PMs are generated at first. Then, two new classes, IX and X, of analytic 6-SPS PMs are generated. The forward displacement analysis (FDA) of the new analytic 6-SPS PMs is also performed. The FDA of the 6-SPS PMs of class IX is reduced to the solution of one univariate cubic equation and two univariate quadratic equations, in sequence, while that of the 6-SPS PMs of class X is reduced to the solution of three univariate quadratic equations in sequence. Both of the new analytic 6-SPS PMs have at most eight assembly modes. © 2001 John Wiley & Sons, Inc. [source]


An efficient co-rotational formulation for curved triangular shell element

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 9 2007
Zhongxue Li
Abstract A 6-node curved triangular shell element formulation based on a co-rotational framework is proposed to solve large-displacement and large-rotation problems, in which part of the rigid-body translations and all rigid-body rotations in the global co-ordinate system are excluded in calculating the element strain energy. Thus, an element-independent formulation is achieved. Besides three translational displacement variables, two components of the mid-surface normal vector at each node are defined as vectorial rotational variables; these two additional variables render all nodal variables additive in an incremental solution procedure. To alleviate the membrane and shear locking phenomena, the membrane strains and the out-of-plane shear strains are replaced with assumed strains in calculating the element strain energy. The strategy used in the mixed interpolation of tensorial components approach is employed in defining the assumed strains. The internal force vector and the element tangent stiffness matrix are obtained from calculating directly the first derivative and second derivative of the element strain energy with respect to the nodal variables, respectively. Different from most other existing co-rotational element formulations, all nodal variables in the present curved triangular shell formulation are commutative in calculating the second derivative of the strain energy; as a result, the element tangent stiffness matrix is symmetric and is updated by using the total values of the nodal variables in an incremental solution procedure. Such update procedure is advantageous in solving dynamic problems. Finally, several elastic plate and shell problems are solved to demonstrate the reliability, efficiency, and convergence of the present formulation. Copyright © 2007 John Wiley & Sons, Ltd. [source]