Tristan B. Smith

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Seasonal fluctuations in resource abundance often cause primates to change their feeding behavior and ecology. The objective of this study was to examine the response of a largely frugivorous monkey, the grey-cheeked mangabey (Lophocebus albigena), to seasonal variations in fruit abundance. We used 15-min scan sampling to quantify feeding, activity, and(More)
Considerable progress has been made over the last 15 years on building adaptive control systems to assist pilots in flying damaged aircraft. Once a pilot has regained control of a damaged aircraft, the next problem is to determine the best site for an emergency landing. In general, the decision depends on many factors including the actual control envelope(More)
The resource-constrained project scheduling problem with time windows (RCPSP/max) is an important generalization of a number of well studied scheduling problems. In this paper, we present a new heuristic algorithm that combines the benefits of squeaky wheel optimization with an effective conflict resolution mechanism, called bulldozing, to address RCPSP/max(More)
PURPOSE Failed crowns and failure load data were studied to gain insights into the fracture behavior of prostheses under incisal-directed, load-to-failure testing. MATERIALS AND METHODS Incisor crowns (n = 68) were fabricated: two all-ceramic groups (feldspathic veneer on high-strength core), differing in core design, and two metal-ceramic groups,(More)
In previous work, we described an Emergency Landing Planner (ELP) designed to assist pilots in choosing the best emergency landing site when damage or failures occur in an aircraft. In this paper, we briefly describe the system, but focus on the integration of this system into the cockpit of a 6 DOF full-motion simulator and a study designed to evaluate the(More)
ATHLETE is a large six-legged tele-operated robot. Each foot is a wheel; travel can be achieved by walking, rolling, or some combination of the two. Operators control ATHLETE by selecting parameterized commands from a command dictionary. While rolling can be done efficiently with a single command, any motion involving steps is cumbersome walking a few(More)
A mixed-initiative approach to activity planning for space mission operations was introduced in the Mars Exploration Rover mission, and has been extended and adapted to other missions. The approach involves a collaboration between a human planner and automated tools that reason about activities and constraints. One important class of constraints arises from(More)
SimYard is a stochastic shipyard simulation tool designed to evaluate the labor costs of executing different schedules in a shipyard production environment. SimYard simulates common production problems such as task delays and labor shortages. A simulated floor manager reacts to problems as they arise. Repeatedly simulating multiple schedules allows the user(More)
This paper describes an approach to the problem of optimal motion planning with uncertain dynamics. This problem can occur whenever a vehicle suffers damage or when the environment makes the effect of motion actions unpredictable and potentially risky. We address in particular the case of aircraft with structural and/or control surface damage. The goal in(More)
A principal obstacle to fielding automated planning systems is the difficulty of modeling. Physical systems are modeled conventionally based on specification documents and the modeler’s understanding of the system. Thus, the model is developed in a way that is disconnected from the system’s actual behavior and is vulnerable to manual error. Another obstacle(More)