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— Cardiac catheterization with ultrasound (US) imaging catheters provides real time US imaging from within the heart, but manually navigating a four degree of freedom (DOF) imaging catheter is difficult and requires extensive training. Existing work has demonstrated robotic catheter steering in constrained bench top environments. Closed-loop control in an unconstrained setting, such as patient vasculature, remains a significant challenge due to friction, backlash, and physiological disturbances. In this paper we present a new method for closed-loop control of the catheter tip that can accurately and robustly steer 4-DOF cardiac catheters and other flexible manipulators despite these effects. The performance of the system is demonstrated in a vasculature phantom and an in vivo porcine animal model. During bench top studies the robotic system converged to the desired US imager pose with submillimeter and sub-degree-level accuracy. During animal trials the system achieved 2.0 mm and 0.65° accuracy. Accurate and robust robotic navigation of flexible manipulators will enable enhanced visualization and treatment during procedures., Engineering and Applied Sciences

Chemical vapor deposition (CVD) of copper and manganese can produce interconnects scaled down to below 10 nm, while enhancing their conductivity and lifetime. CVD using similar super-conformal processes can enable very narrow through-silicon-vias, as well as tiny and robust flexible wires between chips. Silica insulating layers can be made by a super-conformal and rapid atomic layer deposition (ALD) process., Chemistry and Chemical Biology, Engineering and Applied Sciences

— The price of electricity in the Mid-Atlantic (PJM) region of the United States increased during the “Polar Vortex” at the beginning of 2014. Transmission lines were congested because of high demand during the extreme cold weather. The natural gas price for electricity generation increased more than 35% at the end of 2013. Energy Storage Systems (ESS) would period. Other opportunities in energy arbitrage define the greatest scale for storage applications. Real-time and Day-ahead markets in PJM provide alternative arbitrage opportunities. Considering the prices in 2014 for 7,395 locations in PJM, results show the potential revenue for ESS for normal arbitrage and for extreme cold weather events., Engineering and Applied Sciences

We present LLAMA, a graph storage and analysis system that supports mutability and out-of-memory execution. LLAMA performs comparably to immutable main-memory analysis systems for graphs that fit in memory and significantly outperforms existing out-of-memory analysis systems for graphs that exceed main memory. LLAMA bases its implementation on the compressed sparse row (CSR) representation, which is a read-only representation commonly used for graph analytics. We augment this representation to support mutability and persistence using a novel implementation of multi-versioned array snapshots, making it ideal for applications that receive a steady stream of new data, but need to perform whole-graph analysis on consistent views of the data. We compare LLAMA to state-of-the-art systems on representative graph analysis workloads, showing that LLAMA scales well both out-of-memory and across parallel cores. Our evaluation shows that LLAMA's mutability introduces modest overheads of 3-18% relative to immutable CSR for in-memory execution and that it outperforms state-of-the-art out-of-memory systems in most cases, with a best case improvement of 5x on breadth-first-search., Engineering and Applied Sciences

There is a clear, outstanding need for new security mechanisms that allow data to be managed and controlled within the cloud-enabled Internet of Things. Towards this, we propose an approach based on Information Flow Control (IFC) that allows: (1) the continuous, end-to-end enforcement of data flow policy, and (2) the generation of provenance-like audit logs to demon- strate policy adherence and contractual/regulatory compliance. Further, we discuss the role of Trusted Platform Modules (TPMs) in supporting such a system, by providing hardware roots of trust. TPMs can be leveraged to validate software configurations, including the IFC enforcement mechanism, both in the cloud and externally via remote attestation., Engineering and Applied Sciences