This paper describes a new algorithm for computing Min-kowski sums of set-theoretic geometric models. The algorithm uses a variation on Woodwark's method for feature recognition. At the end of the paper we present results from an implementation of the algorithm running on two-dimensional data, and from a more experimental version ray-tracing into three-dimensional Minkowski sums to render a pic...

The popularity of digital devices has greatly increased the chance of manipulating images on computers. In general, image data can be largely divided into raster format and function format. A raster image is composed by a group of pixels arranged in a square tessellation, with each having a certain value or label denoting the color information. This format is suitable for representing images on...

We present a novel 3D curvilinear skeletonization algorithm which produces filtered skeletons without needing any user input, thanks to a new parallel algorithm based on the cubical complex framework. These skeletons are used in a modified path tracing algorithm in order to produce less noisy images in less time than the classical approach.

In this work, the Discrete, Environment-Driven Ray Launching (DED-RL) algorithm, which makes use of parallelization on Graphic Processing Units, fully described in a previous paper, has been validated versus large set measurements to evaluate its performance terms both computational efficiency and accuracy. Three major urban areas have considered, including very challenging scenario central San...

As “smart” devices such as smart phone and smart TVs become widely distributed, various studies on location-based services have been conducted. Such location-based services are useless, however, unless the user’s location is known. A number of researchers have examined methods to trace and determine indoor locations for indoor location-based services. In particular, WALN has been examined in va...

In a Ciphertext-Policy Attribute-Based Encryption (CP-ABE) system, decryption privileges are defined over attributes that could be shared by multiple users. If some of the users leak their decryption privileges to the public or to some third party, say for profit gain, a conventional CP-ABE has no tracing mechanism for finding these malicious users out. There are two levels of traceability for ...

Christian Lauterbach: Interactive Ray Tracing of Massive and Deformable Models. (Under the direction of Dinesh Manocha.) Ray tracing is a fundamental algorithm used for many applications such as computer graphics, geometric simulation, collision detection and line-of-sight computation. Even though the performance of ray tracing algorithms scales with the model complexity, the high memory requir...

We present a fast view-dependent algorithm for ray tracing bended surfaces deened by triangular F-patches. We give up the notion of uniqueness for the surfaces, i.e., a plane containing the ray innuences the shape of the surface. However, the resulting surfaces appear smooth and continuous to the observer. F-patches can be joined G 1-continuous. The method both has low memory consumption and fa...