Physical Sciences and Mathematics Commons^™

Resizable, Scalable, Concurrent Hash Tables, Josh Triplett, Paul E. Mckenney, Jonathan Walpole

Computer Science Faculty Publications and Presentations

We present algorithms for shrinking and expanding a hash table while allowing concurrent, wait-free, linearly scalable lookups. These resize algorithms allow the hash table to maintain constant-time performance as the number of entries grows, and reclaim memory as the number of entries decreases, without delaying or disrupting readers.

We implemented our algorithms in the Linux kernel, to test their performance and scalability. Benchmarks show lookup scalability improved 125x over readerwriter locking, and 56% over the current state-of-the-art for Linux, with no performance degradation for lookups during a resize.

To achieve this performance, this hash table implementation uses a new concurrent …

Hardware Acceleration Of Inference Computing: The Numenta Htm Algorithm, Dan Hammerstrom

Systems Science Friday Noon Seminar Series

In this presentation I will describe the latest version of the Numenta HTM Cortical Learning Algorithm and why it is interesting for doing research into radical new computer architectures. Then I will discuss the hardware acceleration research we are doing, and briefly look at some preliminary applications development.

Developing A Remote Sensing Algorithm For Deriving Soil Moisture From Spectral Reflectance, Santosh Rijal

Theses and Dissertations

Wet weather cycle since 1993 has brought ground water level closer to the surface of the soil in many areas in the Red River Valley (RRV) of the North basin. Many farmers have to delay spring plantation or autumn harvest due to excessive moisture in', their farmland. In such case, it becomes increasingly important to have timely and accurate information on the soil moisture conditions. Conventional soil moisture measurement techniques are point-based that results in poor spatial representation of soil moisture. Remote sensing techniques offer many potential advantages over traditional means such as repetitive coverage and areal representation. The objective …