Volume 4, Number 1, 2007
Special Issue on Virtual Systems and Multimedia (pp.1-37)
The purpose of this research is a quantitative analysis of movement patterns of dance,which cannot be analyzed with a motion capture system alone,using simultaneous measurement of body motion and biophysical information.In this research,two kinds of same leg movement are captured by simultaneous measurement;one is a leg movement with given strength,the other is a leg movement without strength on condition of basic experiment using optical motion capture and electromyography (EMG) equipment in order to quantitatively analyze characteristics of leg movement.Also,we measured the motion of the traditional Japanese dance using the constructed system.We can visualize leg movement of Japanese dance by displaying a 3D CG character animation with motion data and EMG data.In addition,we expect that our research will help dancers and researchers on dance through giving new information on dance movement which cannot be analyzed with only motion capture.
We present a new algorithm to compute a geodesic path over a triangle mesh.Based on Novotnis propagating wavefront method which is similar to the well known Dijkstra algorithm,we made some improvements which Novotni had missed and we also gave the method to find out the geodesic path which Novotni had not.It can handle both convex and non-convex surfaces or even with boundaries.Experiment results show that our method works very well both in efficiency and precision.
A large number of 3D models are created on computers and available for networks.Some content-based retrieval technologies are indispensable to find out particular data from such anonymous datasets.Though several shape retrieval technologies have been developed,little attention has been given to the points on humans sense and impression (as known as Kansei) in the conventional techniques.In this paper,the authors propose a novel method of shape retrieval based on shape impression of humans Kansei.The key to the method is the Gaussian curvature distribution from 3D models as features for shape retrieval.Then it classifies the 3D models by extracted feature and measures similarity among models in storage.
In this paper we introduce an image-based virtual exhibition system especially for clothing product.It can provide a powerful material substitution function,which is very useful for customization clothing-built.A novel color substitution algorithm and two texture morphing methods are designed to ensure realistic substitution result.To extend it to 3D,we need to do the model reconstruction based on photos.Thus we present an improved method for modeling human body.It deforms a generic model with shape details extracted from pictures to generate a new model.Our method begins with model image generation followed by silhouette extraction and segmentation.Then it builds a mapping between pixeis inside every pair of silhouette segments in the model image and in the picture.Our mapping algorithm is based on a slice space representation that conforms to the natural features of human body.
In this paper,we present a framework for the generation and control of an Internet-based 3-dimensionai game virtual environment that allows a character to navigate through the environment.Our framework includes 3-dimensional terrain mesh data processing,a map editor,scene processing,collision processing,and waikthrough control.We also define an environment-specific semantic information editor,which can be applied using specific location obtained from the real world.Users can insert text information related to the characters real position in the real world during navigation in the game virtual environment.
The emergence of high performance 3D graphics cards has opened the way to PC clusters for high performance multi- display environment.In order to exploit the rendering ability of PC clusters,we should design appropriate parallel rendering algorithms and parallel graphics library interfaces.Due to the rapid development of Direct3D,we bring forward DPGL,the Direct3D9-based parallel graphics library in D3DPR parallel rendering system,which implements Direct3D9 interfaces to support existing Direct3D9 application parallelization with no modification.Based on the parallelism analysis of Direct3D9 rendering pipeline,we briefly introduce D3DPR parallel rendering system.DPGL is the fundamental component of D3DPR.After presenting DPGL three layers architecture, we discuss the rendering resource interception and management.Finally,we describe the design and implementation of DPGL in detail, including rendering command interception layer,rendering command interpretation layer and rendering resource parallelization layer.
Segmentation of moving objects in a video sequence is a basic task for application of computer vision.However,shadows extracted along with the objects can result in large errors in object localization and recognition.In this paper,we propose a method of moving shadow detection based on edge information,which can effectively detect the cast shadow of a moving vehicle in a traffic scene.Having confirmed shadows existing in a figure,we execute the shadow removal algorithm proposed in this paper to segment the shadow from the foreground.The shadow eliminating algorithm removes the boundary of the cast shadow and preserves object edges firstly;secondly,it reconstructs coarse object shapes based on the edge information of objects;and finally,it extracts the cast shadow by subtracting the moving object from the change detection mask and performs further processing.The proposed method has been further tested on images taken under different shadow orientations,vehicle colors and vehicle sizes,and the results have revealed that shadows can be successfully eliminated and thus good video segmentation can be obtained.
A blind adaptive scheme is proposed for joint maximum likelihood (ML) channel estimation and data detection of single- input multiple-output (SIMO) systems.The joint ML optimisation over channel and data is decomposed into an iterative optimisation loop.An efficient global optimisation algorithm called the repeated weighted boosting search is employed at the upper level to optimally identify the unknown SIMO channel model,and the Viterbi algorithm is used at the lower level to produce the maximum likelihood sequence estimation of the unknown data sequence.A simulation example is used to demonstrate the effectiveness of this joint ML optimisation scheme for blind adaptive SIMO systems.
Accurate measurement of transit time for acoustic wave between two sensors installed on two sides of a furnace is a key to implementing the temperature field measurement technique based on acoustical method.A new method for measuring transit time of acoustic wave based on active acoustic source signal is proposed in this paper,which includes the followings:the time when the acoustic source signal arrives at the two sensors is measured first;then,the difference of two arriving time arguments is computed,thereby we get the transit time of the acoustic wave between two sensors installed on the two sides of the furnace.Avoiding the restriction on acoustic source signal and background noise,the new method can get the transit time of acoustic wave with higher precision and stronger ability of resisting noise interference.
Engineers often need to look for the right pieces of information by sifting through long engineering documents.It is a very tiring and time-consuming job.To address this issue,researchers are increasingly devoting their attention to new ways to help information users,including engineers,to access and retrieve document content.The research reported in this paper explores how to use the key technologies of document decomposition (study of document structure),document mark-up (with EXtensible Mark- up Language (XML),HyperText Mark-up Language (HTML),and Scalable Vector Graphics (SVG)),and a facetted classification mechanism.Document content extraction is implemented via computer programming (with Java).An Engineering Document Content Management System (EDCMS) developed in this research demonstrates that as information providers we can make document content in a more accessible manner for information users including engineers. The main features of the EDCMS system are: 1) EDCMS is a system that enables users,especially engineers,to access and retrieve information at content rather than document level.In other words,it provides the right pieces of information that answer specific questions so that engineers dont need to waste time sifting through the whole document to obtain the required piece of information. 2) Users can use the EDCMS via both the data and metadata of a document to access engineering document content. 3) Users can use the EDCMS to access and retrieve content objects,i.e.text,images and graphics (including engineering drawings) via multiple views and at different granularities based on decomposition schemes. Experiments with the EDCMS have been conducted on semi-structured documents,a textbook of CADCAM,and a set of project posters in the Engineering Design domain.Experimental results show that the system provides information users with a powerful solution to access document content.
This paper presents a flight control design for an unmanned aerial vehicle (UAV) using a nonlinear autoregressive moving average (NARMA-L2) neural network based feedback linearization and output redefinition technique.The UAV investigated is non- minimum phase.The output redefinition technique is used in such a way that the resulting system to be inverted is a minimum phase system.The NARMA-L2 neural network is trained off-line for forward dynamics of the UAV model with redefined output and is then inverted to force the real output to approximately track a command input.Simulation results show that the proposed approaches have good performance.
Procurement planning with discrete time varying demand is an important problem in Enterprise Resource Planning (ERP).It can be described using the non-analytic mathematical programming model proposed in this paper.To solve the model we propose to use a fuzzy decision embedded genetic algorithm.The algorithm adopts an order strategy selection to simplify the original real optimization problem into binary ones.Then,a fuzzy decision quantification method is used to quantify experience from planning experts.Thus,decision rules can easily be embedded in the computation of genetic operations.This approach is applied to purchase planning problem in a practical machine tool works,where satisfactory results have been achieved.
LDL-factorization is an efficient way of solving Ax=b for a large symmetric positive definite sparse matrix A.This paper presents a new method that further improves the efficiency of LDL-factorization.It is based on the theory of elimination trees for the factorization factor.It breaks the computations involved in LDL-factorization down into two stages:1) the pattern of nonzero entries of the factor is predicted,and 2) the numerical values of the nonzero entries of the factor are computed.The factor is stored using the form of an elimination tree so as to reduce memory usage and avoid unnecessary numerical operations.The calculation results for some typical numerical examples demonstrate that this method provides a significantly higher calculation efficiency for the one-to-one marketing optimization algorithm.
Several LMI representations for delay-independence stability are proposed by applying Projection Lemma and the so- calledSmall Scalar Method.These criteria realize the elimination of the products coupling the system matrices and Lyapunov matrices by introducing some additional matrices.When they are applied to robust stability analysis for polytopic uncertain systems, the vertex-dependent Lyapunov functions are allowed,so less conservative results can be obtained.A numerical example is employed to illustrate the effect of these proposed criteria.
Tracking images using shape descriptor can be more accurate than using other existing methods and it is most useful when the environment is complex.However the existing methods with shape descriptor get more labeled parts to compare and detect the object in an image,which makes the computation more complicated.Thus,we need a trade-off between the accuracy and efficiency requirements.This paper aims to bridge this gap between the accuracy and efficiency requirements by using morphology method. To improve the original monochromatic object detecting system,we propose a new color descriptor to preprocess the image with polychromatic object.Experiments have been conducted and shown the proposed method has made a great improvement in the time complexity minimization comparing with the performances of the original detection algorithm.