Daniel W. Williams

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One of the most common forms of security attacks involves exploiting a vulnerability to inject malicious code into an executing application and then cause the injected code to be executed. A theoretically strong approach to defending against any type of code-injection attack is to create and use a process-specific instruction set that is created by a(More)
Software Dynamic Translation (SDT) is used for instrumentation, optimization, security, and many other uses. A major source of SDT overhead is the execution of code to translate an indirect branch's target address into the translated destination block's address. This article discusses sources of Indirect Branch (IB) overhead in SDT systems and evaluates(More)
We report CT findings in seven patients with diffuse cerebral edema and increased attenuation in the basilar cisterns resembling subarachnoid hemorrhage. On the basis of autopsy (three cases) and lumbar puncture (four cases) findings, true subarachnoid hemorrhage was reasonably excluded. Pathophysiologic changes that occur with diffuse cerebral edema are(More)
Software Dynamic Translation (SDT) systems have been used for program instrumentation, dynamic optimization, security policy enforcement, intrusion detection, and many other uses. To be widely applicable, the overhead (runtime, memory usage, and power consumption) should be as low as possible. For instance, if an SDT system is protecting a web server(More)
The authors report three cases of penetrating craniocervical injury by wooden foreign bodies, which were initially hypodense on CT and thought to be air. When these structures were scrutinized with higher window settings, they had a higher attenuation and a unique striated internal architecture which the authors propose may be specific to wood.
Processor performance continues to out pace memory performance by a large margin. The growing popularity of mul-ticore and manycore architectures further exacerbates this problem. The challenge of keeping the processor(s) fed with data becomes more difficult. One approach for mitigating this gap is to employ software-based speculative prefetch-ing. Software(More)
This report describes the intracranial CT and MR findings in two cases of Klippel-Trenaunay-Weber Syndrome. The findings are 1) markedly enhancing choroid plexuses, 2) severe cerebral atrophy, 3) cerebral calcifications, and 4) angiomatous leptomeningeal enhancement. The findings may resemble those seen in cases of bilateral Sturge-Weber syndrome. The two(More)
Humans and mice detect pain, itch, temperature, pressure, stretch and limb position via signaling from peripheral sensory neurons. These neurons are divided into three functional classes (nociceptors/pruritoceptors, mechanoreceptors and proprioceptors) that are distinguished by their selective expression of TrkA, TrkB or TrkC receptors, respectively. We(More)