Learn More
We consider the problem of implementing transactional memory in large-scale distributed networked systems. We present Spiral, a novel distributed directory-based protocol for transactional memory, and theoretically analyze and experimentally evaluate it for the performance boundaries of this approach from the worst-case perspective. Spiral is designed for(More)
Pipeline-based applications have become the indispensable part of life. Active monitoring and frequent inspections are critical to maintaining pipeline health. However, these tasks are highly expensive using the traditional maintenance systems, knowing that the pipeline systems can be largely deployed in an inaccessible and hazardous environment. In this(More)
We consider greedy contention managers for transactional memory for M × N excution windows of transactions with M threads and N transactions per thread. Assuming that each transaction conflicts with at most C other transactions inside the window, a trivial greedy contention manager can schedule them within CN time. In this paper, we show that there are much(More)
—Pipeline-based applications have become an integral part of life. However, knowing that the pipeline systems can be largely deployed in an inaccessible and hazardous environment, active monitoring and frequent inspection of the pipeline systems are highly expensive using the traditional maintenance systems. Robot agents have been considered as an(More)
We consider transactional memory contention management in the context of balanced workloads, where if a transaction is writing, the number of write operations it performs is a constant fraction of its total reads and writes. We explore the theoretical performance boundaries of contention management in balanced workloads from the worst-case perspective by(More)
We provide a novel analysis framework for distributed hierarchical directories for an arbitrary set of dynamic (online) requests. We first present a generic algorithm for implementing a distributed directory that can support dynamic requests and prove an upper bound on the competitive ratio for communication cost experienced by this algorithm using the(More)
—In this paper, we present the design concept and motion planning of a single-moduled fully autonomous mobile pipeline exploration robot that can be used for the inspection of Φ130∼150mm pipelines. In this robot, the four straight wall-press caterpillar wheels are fixed 90 degrees apart in its circumstance and each wheel is operated by two DC motors(More)
We consider the problem of repositioning N autonomous robots on a plane so that each robot is visible to all others (the Complete Visibility problem), a robot cannot see another robot if there is a third robot positioned between them on the straight line joining them. Robots communicate using collared lights. The computation is synchronous and each robot(More)