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Web-based programming exercises are a useful way for students to practice and master essential concepts and techniques presented in introductory programming courses. Although these systems are used fairly widely, we have a limited understanding of how students use these systems, and what can be learned from the data collected by these systems.In this paper, we perform a preliminary exploratory analysis of data collected by the CloudCoder programming exercise system from five introductory courses taught in two programming languages across three colleges and universities. We explore a number of interesting correlations in the data that confirm existing hypotheses. Finally, and perhaps most importantly, we demonstrate the effectiveness and future potential of systems like CloudCoder to help us study novice programmers.

A biological organism's ability to sense and adapt to its environment is essential to its survival. Likewise, environmentally aware computing systems avail themselves to a longer operational life and a wider range of applications than traditional systems. In this paper, we propose a novel circuit design methodology that allows parameterizable hardware to self-regulate its temperature. We apply this methodology to an image recognition system on an Xilinx Virtex 4 FX100 field programmable gate array (FPGA). The image recognition system sustains a safe operational temperature by automatically adjusting its frequency and output quality. The circuit sacrifices output performance and quality to lower its internal temperature as the ambient temperature increases, and can leverage cooler temperatures by increasing output performance and quality. Furthermore, the circuit will shutdown if the ambient temperature becomes too hot for the device to function properly. A performance evaluation of our adaptive circuit under various thermal conditions shows up to a 4x factor increase in performance and a 2x factor increase in quality over a system without dynamic thermal control.

Abstract. Today's crucial information networks are vulnerable to fastmoving attacks by Internet worms and computer viruses. These attacks have the potential to cripple the Internet and compromise the integrity of the data on the end-user machines. Without new types of protection, the Internet remains susceptible to the assault of increasingly aggressive attacks. A platform has been implemented that actively detects and blocks worms and viruses at multi-Gigabit/second rates. It uses the Field-programmable Port Extender (FPX) to scan for signatures of malicious software (malware) carried in packet payloads. Dynamically reconfigurable Field Programmable Gate Array (FPGA) logic tracks the state of Internet flows and searches for regular expressions and fixedstrings that appear in the content of packets. Protection is achieved by the incremental deployment of systems throughout the Internet.