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Distributed Artificial Intelligence is concerned with problem solving in which groups solve tasks. In this paper we describe strategies of cooperation that groups require to solve shared tasks effectively. We discuss such strategies in the context of a specific group problem solving application: collision avoidance in air traffic control. Experimental(More)
PARAMICS is a <i>PARA</i>llel <i>MIC</i>roscopic Traffic Simulator which is, to our knowledge, the most powerful of its type in the world. The simulator can model around 200,000 vehicles on around 7,000 roads (taken from real road traffic network data) at faster than 'real-time' rates, making use of 16K processor TMC Connection Machine CM-200 for the(More)
Experimental traumatic brain injury studies have shown that cerebral hyperglycolysis is a pathophysiological response to injury-induced ionic and neurochemical cascades. This finding has important implications regarding cellular viability, vulnerability to secondary insults, and the functional capability of affected regions. Prior to this study,(More)
Utilizing [18F]fluorodeoxyglucose positron emission tomography (FDG-PET), we studied the correlation between CMRglc and the level of consciousness within the first month following human traumatic brain injury. Forty-three FDG-PET scans obtained on 42 mild to severely head-injured patients were quantitatively analyzed for the determination of regional(More)
Brain trauma is accompanied by regional alterations of brain metabolism, reduction in metabolic rates and possible energy crisis. We hypothesize that microdialysis markers of energy crisis are present during the critical period of intensive care despite the absence of brain ischemia. In all, 19 brain injury patients (mean GCS 6) underwent combined positron(More)
OBJECT Progressive intracranial hemorrhage after head injury is often observed on serial computerized tomography (CT) scans but its significance is uncertain. In this study, patients in whom two CT scans were obtained within 24 hours of injury were analyzed to determine the incidence, risk factors, and clinical significance of progressive hemorrhagic injury(More)
UNLABELLED The purpose of this study was to determine if the relationship between abnormalities in glucose, lactate, and oxygen metabolism were predictive of neurologic outcome after moderate or severe head injury, relative to other known prognostic factors. Serial assessments of the cerebral metabolic rates for glucose, lactate, and oxygen were performed(More)
UNLABELLED After traumatic brain injury (TBI), subcortical white matter damage may induce a functional disconnection leading to a dissociation of regional cerebral metabolic rate of glucose (CMRglc) between the cerebral cortex and deeper brain regions. Therefore, thalamic and brain stem CMRglc may have a closer correlation than does the cerebral cortex with(More)
OBJECT The purpose of this prospective study was to evaluate the cumulative incidence, duration, and time course of cerebral vasospasm after traumatic brain injury (TBI) in a cohort of 299 patients. METHODS Transcranial Doppler (TCD) ultrasonography studies of blood flow velocity in the middle cerebral and basilar arteries (VMCA and VBA, respectively)(More)
Following traumatic brain injury (TBI), patients often report memory difficulties, as well as reduced information processing speed. However, it remains unclear the extent to which these deficits contribute to functional impairment. In the present study, we compared the relative contribution of verbal memory and information processing speed to functional(More)