Approximation Algorithms for Survivable Multicommodity Flow Problems with Applications to Network Design

Multicommodity flow (MF) problems have a wide variety of applications in areas such as VLSI circuit design, network design, etc., and are therefore very well studied. The fractional MF problems are polynomial time solvable while integer versions are NP-complete. However, exact algorithms to solve the fractional MF problems have high computational complexity. Therefore approximation algorithms to solve the fractional MF problems have been explored in the literature to reduce their computational complexity. Using these approximation algorithms and the randomized rounding technique, polynomial time approximation algorithms have been explored in the literature. In the design of high-speed networks, such as optical wavelength division multiplexing (WDM) networks, providing survivability carries great significance. Survivability is the ability of the network to recover from failures. It further increases the complexity of network design and presents network designers with more formidable challenges. In this work we formulate the survivable versions of the MF problems. We build approximation algorithms for the survivable multicommodity flow (SMF) problems based on the framework of the approximation algorithms for the MF problems presented in [1] and [2]. We discuss applications of the SMF problems to solve survivable routing in capacitated networks.

The Use of Digital Motion-Sensor Cameras to Capture Coyote Presence in Western Georgia

Because of their learned avoidance of humans and the dense cover provided by forested areas, observation of coyote activity is often very limited in the Southeast. In this study we used digital motion-sensor cameras to detect activity among coyote populations in various urban and rural habitats. Camera stations were placed adjacent to regenerating clear cuts, forest trails and roads, agriculture fields, residential areas, and within city parks to determine activity and presence of coyotes in these various areas. Cameras were successful in detecting coyotes in all study sites throughout the year. Coyotes appear to show no avoidance of camera stations. Cameras may be helpful in gathering general biological and activity information on coyote populations in an area.

Using Three Dimensional Motion Capture Technology to Describe and Assess Piano Technique: A Case Study

The purpose of the study was to examine any differences that exist in the quality of motions employed by pianists when they are sight-reading versus performing repertoire. A secondary question of interest was whether or not an improvement in the efficiency of motion could be observed between two sight-reading trials of the same musical excerpt. While data analysis for the full study is ongoing, the following results from a case study are illustrative.