Energy is increasingly a first-order concern in computer systems. Exploiting energy-accuracy trade-offs is an attractive choice in applications that can tolerate inaccuracies. A key challenge, though, is how to isolate parts of the program that must be precise from those that can be approximated so that a program functions correctly even as quality of service degrades. Addressing that challenge leads to opportunities for approximate computing across the entire system stack.
Software obfuscation aims to make the code of a computer program "unintelligible'' while preserving its functionality. This problem was first posed by Diffie and Hellman in 1976, and so far, most cryptographers believed that realizing obfuscation was impossible.
My research provides the first secure solution to this problem. Consequently several other long-standing open problems have been resolved. In this talk, I will describe these new developments and their implications.
By 2020, there will be billions of devices connecting to the Internet. These devices will be ubiquitous and will generate large amounts of sensing and monitoring data that will enable a multitude of applications to improve human life. The key enabler of this vision is the underlying wireless communication technology. However, current wireless networks are notoriously interference-limited. With the number of devices increasing to the billions in the future, current solutions will be crippled to support the amount of data that needs to be communicated.
Computer systems have faced significant power challenges at many points in their history, but over the past 20 years, these challenges have shifted from mainly being addressed at the devices and circuits level, to their current position as first-order constraints for architects and software developers. With power concerns creeping up the implementation layers, while application-level changes alter the nature of computation being performed, the natural approaches and opportunities for power mitigation require constant innovation.
I will discuss new methods and studies that aim to improve eyes-free data entry for blind mobile device users. Currently, mobile devices are generally accessible to blind people, but text entry is almost prohibitively slow. Studies show that blind people enter text on an iPhone at a rate of just 4 words per minute. I will present Perkinput, a chording text entry method where users touch the screen with one to three fingers at a time in patterns based on Braille. Instead of soft keys, Perkinput uses concepts from signal detection theory to determine the user’s input.