Christopher P. Diehl

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Many datasets of interest today are best described as a linked collection of interrelated objects. These may represent homogeneous networks, in which there is a single-object type and link type, or richer, heterogeneous networks, in which there may be multiple object and link types (and possibly other semantic information). Examples of homogeneous networks(More)
Remote identification of people is an important capability for security systems. Automatically controlling a pan-tilt-zoom camera is an effective way to collect high resolution video or images of people in an unconstrained environment. Often there will be more people in an area than cameras available. The cameras must then divide their time among the people(More)
In recent years, informal, online communication has transformed the ways in which we connect and collaborate with friends and colleagues. With millions of individuals communicating online each day, we have a unique opportunity to observe the formation and evolution of roles and relationships in networked groups and organizations. Yet a number of challenges(More)
To conduct real-time video surveillance using low-cost commercial off-the-shelf hardware, system designers typically define the classifiers prior to the deployment of the system so that the performance of the system can be optimized for a particular mission. This implies the system is restricted to interpreting activity in the environment in terms of the(More)
Online communications provide a rich resource for understanding social networks. Information about the actors, and their dynamic roles and relationships, can be inferred from both the communication content and traffic structure. A key component in the analysis of online communications such as email is the resolution of name references within the body of the(More)
We begin by considering current shortfalls with conventional surveillance systems and discuss the potential advantages of distributed, collaborative surveillance systems. Distributed surveillance systems o er the capability to monitor activity from multiple locations over time thereby increasing the likelihood of obtaining discriminating data necessary for(More)
The objective of the CyberScout project is to develop an autonomous surveillance and reconnaissance system using a network of all-terrain vehicles. In this paper, we focus on two facets of this system: 1) vision for surveillance and 2) autonomous navigation and dynamic path planning. In the area of vision-based surveillance, we have developed robust,(More)
There is increasing interest in the storage, retrieval, and analysis of email communications. One active area of research focuses on the inference of properties of the underlying social network giving rise to the email communications[1, 2]. Email communication between individuals implies some type of relationship, whether it is formal, such as a(More)
PURPOSE To evaluate contrast threshold and contrast gain in patients with optic neuritis under conditions designed to favor mediation by either the inferred magnocellular (MC) or parvocellular (PC) pathway. METHODS Achromatic and chromatic contrast discrimination was measured in 11 patients with unilateral or bilateral optic neuritis and in 18 age-matched(More)