			Home About us Contact

Direct Mapping (direct + mapping)

Distribution by Scientific Domains

Information Science and Computing	50%

Selected Abstracts

Wind projection basis for real-time animation of trees

COMPUTER GRAPHICS FORUM, Issue 2 2009
Julien Diener
This paper presents a real-time method to animate complex scenes of thousands of trees under a user-controllable wind load. Firstly, modal analysis is applied to extract the main modes of deformation from the mechanical model of a 3D tree. The novelty of our contribution is to precompute a new basis of the modal stress of the tree under wind load. At runtime, this basis allows to replace the modal projection of the external forces by a direct mapping for any directional wind. We show that this approach can be efficiently implemented on graphics hardware. This modal animation can be simulated at low computation cost even for large scenes containing thousands of trees. [source]

A semantic entropy metric

JOURNAL OF SOFTWARE MAINTENANCE AND EVOLUTION: RESEARCH AND PRACTICE, Issue 4 2002
Letha H. Etzkorn
Abstract This paper presents a new semantically-based metric for object-oriented systems, called the Semantic Class Definition Entropy (SCDE) metric, which examines the implementation domain content of a class to measure class complexity. The domain content is determined using a knowledge-based program understanding system. The metric's examination of the domain content of a class provides a more direct mapping between the metric and common human complexity analysis than is possible with traditional complexity measures based on syntactic aspects (software aspects related to the format of the code). Additionally, this metric represents a true design metric that can measure complexity early in the life cycles of software maintenance and software development. The SCDE metric is correlated with analyses from a human expert team, and is also compared to syntactic complexity measures. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Toward direct mapping of neuronal activity: MRI detection of ultraweak, transient magnetic field changes,

MAGNETIC RESONANCE IN MEDICINE, Issue 6 2002
Jerzy Bodurka
Abstract A novel method based on selective detection of rapidly changing ,B0 magnetic fields and suppression of slowly changing ,B0 fields is presented. The ultimate goal of this work is to present a method that may allow detection of transient and subtle changes in B0 in cortical tissue associated with electrical currents produced by neuronal activity. The method involves the detection of NMR phase changes that occur during a single-shot spin-echo (SE) echo-planar sequence (EPI) echo time. SE EPI effectively rephases all changes in B0 that occur on a time scale longer than the echo time (TE) and amplifies all ,B0 changes that occur during TE/2. The method was tested on a phantom that contains wires in which current can be modulated. The sensitivity and flexibility of the technique was demonstrated by modulation of the temporal position and duration of the stimuli-evoked transient magnetic field relative to the 180 RF pulse in the imaging sequence,requiring precise stimulus timing. Currently, with this method magnetic field changes as small as 2 × 10,10 T (200 pT) and lasting for 40 msec can be detected. Implications for direct mapping of brain neuronal activity with MRI are discussed. Magn Reson Med 47:1052,1058, 2002. Published 2002 Wiley-Liss, Inc. [source]