The problem of eliminating the effects of critical races on asynchronous machines is considered in a control theoretic context. State feedback controllers that eliminate the effects of critical races are developed. The results include necessary and sufficient conditions for the existence of such controllers and algorithms for their design. When the controllers exist, they eliminate the race effects and control the machine to match a given race-free model.

Reducing the carbon footprint of data centers is becoming a primary goal of large IT companies. Unlike traditional energy sources, renewable energy sources are usually intermittent and unpredictable. How to better utilize the green energy from these renewable sources in data centers is a challenging problem. In this paper, we exploit the opportunities offered by geographical load balancing, opportunistic scheduling of delay-tolerant workloads, and thermal storage management in data centers to facilitate green energy integration and reduce the cost of brown energy usage. Moreover, bandwidth cost variations between users and data centers are considered. Specifically, this problem is first formulated as a stochastic program, and then, an online control algorithm based on the Lyapunov optimization technique, called Stochastic Cost Minimization Algorithm (SCMA), is proposed to solve it. The algorithm can enable an explicit trade-off between cost saving and workload delay. Numerical results based on real-world traces illustrate the effectiveness of SCMA in practice.

Abstract-Transmission power control (TPC) has been extensively used not only to save energy, but also to improve the network throughput in wireless ad hoc networks. Among the existing throughput-oriented TPC protocols, many can achieve significant throughput improvement but have to use multiple channels and/or multiple transceivers, and others just require a single channel and a single transceiver but can only have limited throughput enhancement. In this paper, we propose a new adaptive transmission power control protocol, ATPMAC, which can improve the network throughput significantly using a single channel and a single transceiver. Specifically, by controlling the transmission power, ATPMAC can enable several concurrent transmissions without interfering with each other. Moreover, ATPMAC does not introduce any additional signalling overhead. We show by simulations that ATPMAC can improve the network throughput by up to 136% compared to IEEE 802.11 in a random topology.Index Terms-Wireless ad hoc networks; MAC protocol; transmission power control.

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Engineering education needs to focus on equipping students with foundational math, science, and engineering skills, with development of critical and higher-order thinking so they can address novel and complex problems and challenges. Learning through a medium that combines course materials with game characteristics can be a powerful tool for engineering education. Games need to be designed for higher order engagement with students, which go beyond remembering, understanding and applying of engineering concepts. In this paper, we present design, development, implementation, and evaluation of a game for engineers. The developed game is founded on experiential learning theory and uses enhanced game characteristics. The racecar game has been designed to facilitate higher-order learning of geometric tolerancing concepts. The course module has been developed and implemented, with assessment of outcomes. The results show that students using the game module, when compared with the control group (lecture-based instruction), had significant improvements when addressing questions that involved higher-order cognition. Survey results also indicate positive student attitudes towards the learning experience with game modules.