Vehicle Localization Service

An evaluation system and related processes are provided for evaluating computing systems associated with vehicle mapping, navigation, and/or control. An evaluation system can include ground truth data generated based on sensor data from an evaluation sensor system as an evaluation vehicle traverses a travelway. A trial system can be evaluated by comparing one or more outputs of the trial system with the ground truth data at the evaluation system. The ground truth data can be projected onto a map associated with a trial vehicle position as it maneuvers along a travelway. Simulated output data of the trial system can be generated based on the projected ground truth data. The simulated output data can then be compared with an actual output of the trial system. Data indicative of the performance of the trial system can be generated based on the comparison between the trial system output and the ground truth data

Duplicate Data Elimination in a SAN File System

Duplicate Data Elimination (DDE) is our method for identifying and coalescing identical data blocks in Storage Tank, a SAN file system. On-line file systems pose a unique set of performance and implementation challenges for this feature. Existing techniques, which are used to improve both storage and network utilization, do not satisfy these constraints. Our design employs a combination of content hashing, copy-on-write, and lazy updates to achieve its functional and performance goals. DDE executes primarily as a background process. The design also builds on Storage Tank’s FlashCopy function to ease implementation.1 We include an analysis of selected real-world data sets that is aimed at demonstrating the space-saving potential of coalescing duplicate data. Our results show that DDE can reduce storage consumption by up to 80% in some application environments. The analysis explores several additional features, such as the impact of varying file block size and the contribution of whole file duplication to the net savings