An Intelligent Approach To Discrete Sampling Of Parametric Curves

In graphics and animation applications, two of the problems are: (1) representation of an analytic curve by a discrete set of sampled points and (2) determining the similarity between two parametric curves. It is necessary to measure the accuracy of approximation and to have a metric to calculate the disparity between two parametric curves. Both of these problems have been associated with the reparameterization of the curves with respect to arc length. One of the methods uses Gaussian Quadrature to determine the arc length parameterization [Guenter and Parent 1990], while another interesting technique is a simple approximation method [Fritsch and Nielson 1990]. There are various ways to compute the similarity between two curves. For 2D Cartesian curves, max norm yields a satisfactory distance metric. For parametric curves, Euclidean norm is frequently used. Arc length is reasonable parameterization, but explicit arc length parameterization is not easy to compute for arbitrary parametric curves. We give a new technique for discretizing parametric curves. These sampled points can be used to approximate curves, determine arc length parameterization, and similarity between them. This technique is accurate, robust and simpler to implement. Comparisons of the previous methods with the new one is presented

Blended Root Finding Algorithm Outperforms Bisection and Regula Falsi Algorithms

Finding the roots of an equation is a fundamental problem in various fields, including numerical computing, social and physical sciences. Numerical techniques are used when an analytic solution is not available. There is not a single algorithm that works best for every function. We designed and implemented a new algorithm that is a dynamic blend of the bisection and regula falsi algorithms. The implementation results validate that the new algorithm outperforms both bisection and regula falsi algorithms. It is also observed that the new algorithm outperforms the secant algorithm and the Newton-Raphson algorithm because the new algorithm requires fewer computational iterations and is guaranteed to find a root. The theoretical and empirical evidence shows that the average computational complexity of the new algorithm is considerably less than that of the classical algorithms

Java, Java, Java

Everyone is talking about Java. The driving force for this chatter is Java\u27\u27s simplicity and potential power. Java is programming language, and a language for the intranet and the World Wide Web (WWW). Java is a Write On one platform and Run on Many platforms (WORM) language. For network-friendly, platform-independent applications, Java (originally Oak) is an object oriented programming language. Java source code is compiled into a virtual machine code or bytecode. This makes the Java platform independent. It can be placed on a Web site, and executed on the client side on a PC-Intel, Mac, Motorola or UNIX-Solaris machine without recompiling. Sun Microsystems formally announced Java in May 1995. Java is the first language that has built-in capabilities for networking applications, in particular, creating dynamic Web pages. Java programs that run on the Internet Web pages are called applets. These applets are easily incorporated into Web pages. These applets are executed from homepages on remote Web sites. Java programs run interpretively on the client side. Java reduces development costs and speeds up the learning curve. Traditional client server development tools-such as Delphi, Power-Builder and Visual Basic-are losing ground to Java as a result. By the year-end of 1996, Java had moved ahead in use of both C and C++ and these application development tool

Tracking the 6-DOF Flight Trajectory of Windborne Debris using Stereophotogrammetry

Numerous post-windstorm investigations have reported that windborne debris can cause costly damage to the envelope of buildings in urban areas under strong winds (e.g., during hurricanes or tornados). Thus, understanding the physics of debris flight is of critical importance. Previously developed numerical models describing debris flight physics have not been validated for the complex urban flow environment; such a validation requires experimentally measuring the debris flight trajectory in wind tunnel tests. In this context, this paper proposes a debris measurement algorithm using stereophotogrammetry. This algorithm aims to determine the six-degree-of-freedom (6-DOF) trajectory and velocity of flying debris, addressing the research gap, i.e., the lack of an algorithm/software for measuring three-rotational-DOF using stereophotogrammetry. This is a civil engineering problem, but computer graphics is the foundation to solve it. This paper focuses on the theoretical development of the algorithm. The developed algorithm can be readily implemented in modern wind tunnel experiments

Performance Evaluation of Hybrid Coding of Images Using Wavelet Transform and Predictive Coding

Image compression techniques are necessary for the storage of huge amounts of digital images using reasonable amounts of space, and for their transmission with limited bandwidth. Several techniques such as predictive coding, transform coding, subband coding, wavelet coding, and vector quantization have been used in image coding. While each technique has some advantages, most practical systems use hybrid techniques which incorporate more than one scheme. They combine the advantages of the individual schemes and enhance the coding effectiveness. This paper proposes and evaluates a hybrid coding scheme for images using wavelet transforms and predictive coding. The performance evaluation is done using a variety of different parameters such as kinds of wavelets, decomposition levels, types of quantizers, predictor coefficients, and quantization levels. The results of evaluation are presented

Computational Intelligence In CAD/CAM Applications

This paper presents a fundamental, direct, and powerful approach to the surface/surface intersection problem in CAD/CAM applications. The algorithm is designed and implemented in three steps: a) Preprocessing- locate the potentially intersecting sections of the surfaces and decompose the surfaces into surface elements within specified flatness tolerance; b) Intersection- decompose the possibly intersecting pairs of surface elements into continuous surface triangulations to find the approximate intersections between the pairs of surface elements; c) Postprocessing-assemble the intersection primitives into curves of intersection, refine the accuracy of computed intersection points, and compact the intersection curves. This surface/surface intersection algorithm is applicable to the widest class, C°, of parametric surfaces, an enhancement over the existing algorithms applicable to only Ck, k≥ 1, surfaces. This implementation, based on computational intelligence, requires no human interaction for intersection curve pattern recognition

Interactive DNA Sequence and Structure Design for DNA Nanotechnology and DNA Computation

DNA sequence and structure design are very important for DNA nanotechnology and DNA computation. A computer aided design tool is needed for exploring DNA sequence and structure of interests before experimental synthesis, which is a very time and labor consuming process. In this paper, an interactive DNA sequence and structure design software tool called DNA shop is proposed and implemented

Interactive DNA Sequence and Structure Design for DNA Nanoapplications

DNA sequence and structure design is very important for DNA nanoapplications. A computer-aided design tool is needed for exploring DNA sequence and structure of interests before experimental synthesis, which is a time- and labor-consuming process. In this paper, an interactive DNA sequence and structure design software tool called DNA shop is proposed and implemented. The visualization tool can generate DNA structures by specifying, selecting, and moving DNA sequences around and display corresponding structures. Using the tool, DNA sequence and structure can be visually inspected in three-dimensional space before experimental studies

VisCFSM: Visual, Constraint-Based, Frequent Subgraph Mining

Abstract-Graphs long have been valued as a pictorial way of representing relationships between entities. Contemporary applications use graphs to model social networks, protein interactions, chemical structures, and a variety of other systems. In many cases, it is useful to detect patterns within graphs. For example, one could be interested in identifying frequently occurring subgraphs, which is known as the frequent subgraph mining problem. A complete solution to this problem can result in numerous subgraphs and can be time-consuming to compute. An approximate solution is faster, but is subject to static heuristics that are beyond the control of the user. Herein we present VisCFSM, a visual, constraint-based, frequent subgraph mining system which allows the user to dynamically specify a variety of constraints on the subgraphs to be found while the mining algorithm is running. The constraint specification interactions are performed through a visual user interface, thereby facilitating a form of visual algorithm steering. This approach can be integrated with any frequent subgraph mining algorithm. Most importantly, this approach has the potential for the user to better, and more quickly, find the information that is of most interest to him/her in a graph