Cottonmouth (Agkistrodon piscivorus) spatial ecology.

Radio-telemetry was used to study spatial ecology of a Cottonmouth (Agkistrodon piscivorus) population in eastern Texas. I examined effects of sex, reproductive state, and body size on spatial use within a riparian habitat. Snakes inhabited a relatively linear environment, restricting movements to the vicinity of the stream. Males occupied larger home ranges than both gravid and non-gravid females. Gravid females exhibited marginally larger home ranges than non-gravid females, but any effects attributable to reproductive state were relatively small when compared to sex differences in spatial use. Body size was positively correlated with home range size but did not account for observed home range differences among population subunits

Effect of High In-Situ Stress on Braced Excavations

The two underground stations and portals of Metro Gold Line\u27s East Los Angeles extension were excavated in heavily over-consolidated alluvium. The excavations were supported with heavy soldier piles with pre-loaded steel-pipe struts. When measured strut loads increased to up to 3 times the design value, and strut-waler connections began to buckle, the contractor was directed to install additional struts. Maintaining that the problem had been caused by inadequate construction means and methods, the owner denied a change-order request for this work. This paper describes the contractor’s investigation into the cause of strut overloading in preparation for a formal hearing by a Dispute Resolution Board. The study concluded that the extremely high bracing loads were caused by high in-situ stresses in the region, which had not been accounted for in the shoring-pressure diagrams provided in the contract drawings

A distributed camera system for multi-resolution surveillance

We describe an architecture for a multi-camera, multi-resolution surveillance system. The aim is to support a set of distributed static and pan-tilt-zoom (PTZ) cameras and visual tracking algorithms, together with a central supervisor unit. Each camera (and possibly pan-tilt device) has a dedicated process and processor. Asynchronous interprocess communications and archiving of data are achieved in a simple and effective way via a central repository, implemented using an SQL database. Visual tracking data from static views are stored dynamically into tables in the database via client calls to the SQL server. A supervisor process running on the SQL server determines if active zoom cameras should be dispatched to observe a particular target, and this message is effected via writing demands into another database table. We show results from a real implementation of the system comprising one static camera overviewing the environment under consideration and a PTZ camera operating under closed-loop velocity control, which uses a fast and robust level-set-based region tracker. Experiments demonstrate the effectiveness of our approach and its feasibility to multi-camera systems for intelligent surveillance