Physical Sciences and Mathematics Commons^™

Two Approximate Minkowski Sum Algorithms, Victor Milenkovic, Elisha P. Sacks

Department of Computer Science Faculty Publications

We present two approximate Minkowski sum algorithms for planar regions bounded by line and circle segments. Both algorithms form a convolution curve, construct its arrangement, and use winding numbers to identify sum cells. The first uses the kinetic convolution and the second uses our monotonic convolution. The asymptotic running times of the exact algorithms are increased by kmlogm with m the number of segments in the convolution and with k the number of segment triples that are in cyclic vertical order due to approximate segment intersection. The approximate Minkowski sum is close to the exact sum of perturbation regions that …

Comparison Of Clustered Rdf Data Stores, Venkata Patchigolla

Purdue Polytechnic Masters Theses

Storing data in RDF format helps in simpler data interchange among different researchers compared to present approaches. There has been tremendous increase in the applications that use RDF data. The nature of RDF data is such that it tends to increase explosively. This makes it necessary to consider the time for retrieval and scalability of data while selecting a suitable RDF data store for developing applications. The research concentrates on comparing BigOWLIM. Bigdata, 4store and Virtuoso RDF stores on basis of their scalability and performance of storing and retrieving cancer proteomics and mass spectrometry data using SPARQL queries. In this …

A Cost-Benefit Analysis Of A Campus Computing Grid, Preston M. Smith

Purdue Polytechnic Masters Theses

Any major research institution has a substantial number of computer systems on its campus, often in the scale of tens of thousands. Given that a large amount of scientific computing is appropriate for execution in an opportunistic environment, a campus grid is an inexpensive way to build a powerful computational resource. What is missing, though, is a model for making an informed decision on the cost-effectives of a campus grid. In this thesis, the author describes a model for measuring the costs and benefits of building a campus computing resource based on the institution’s existing investment in computing hardware.

For …

Controlled Linear Perturbation, Elisha P. Sacks, Victor Milenkovic, Min-Ho Kyung

Department of Computer Science Faculty Publications

We present an algorithmic solution to the robustness problem in computational geometry, called controlled linear perturbation, and demonstrate it on Minkowski sums of polyhedra. The robustness problem is how to implement real RAM algorithms accurately and efficiently using computer arithmetic. Approximate computation in floating point arithmetic is efficient but can assign incorrect signs to geometric predicates, which can cause combinatorial errors in the algorithm output. We make approximate computation accurate by performing small input perturbations, which we compute using differential calculus. This strategy supports fast, accurate Minkowski sum computation. The only prior robust implementation uses a less efficient algorithm, requires …

Visual Learning Styles Among Digital Natives, Eric Palmer

Department of Computer Graphics Technology Degree Theses

This study explored the concept of digital nativity and its educational implications, including application of the learning styles hypothesis. The concept of digital natives, first put forth by Marc Prensky, introduced the notion that individuals raised in a technological environment have developed in such a way as to utilize information differently than the non-native generations before them. This study examined the possibility that these differences may include an increased efficiency in the utilization of narrative imagery versus textual information. The potential benefit of utilizing narrative imagery as an instructional tool is discussed. An experimental test application was developed for the …