Compressing Optimal Paths with Run Length Encoding

Authors: Ben Strasser, Adi Botea, Daniel Harabor

JAIR 2015 | Venue PDF | Archive PDF | Plain Text | LLM Run Details

Reproducibility Variable Result LLM Response
Research Type Experimental Our algorithm achieves query running times on the 100 nanosecond scale, being significantly faster than state-of-the-art first-move oracles from the literature. Space consumption is competitive, due to a compression approach that rearranges rows and columns in a first-move matrix and then performs run length encoding (RLE) on the contents of the matrix. [...] We undertake a detailed empirical analysis including comparisons of our techniques with state-of-the-art variants of CPDs (Botea, 2012), and Hub-Labeling (Delling, Goldberg, Pajor, & Werneck, 2014).
Researcher Affiliation Collaboration Ben Strasser EMAIL Karlsruhe Institute of Technology Karlsruhe, Germany Adi Botea EMAIL IBM Research Dublin, Ireland Daniel Harabor EMAIL NICTA Sydney, Australia
Pseudocode No The paper describes algorithmic steps in paragraph text within Section 9.3 'Compressing Rows with Run Length Encoding' but does not present them in a structured pseudocode block or explicitly labeled algorithm figure.
Open Source Code No The paper mentions using the original C++ implementations of third-party algorithms (Copa-G, Copa-R) in Section 11.3, but it does not provide any explicit statement or link for the source code of the authors' own methodology (SRC and MRC).
Open Datasets Yes The first two sets of benchmark instances have appeared in the 2012 Grid-Based Path Planning Competition. The third benchmark set consists of two worst case maps... available as part of Nathan Sturtevant’s extended problem repository at http://movingai.com/benchmarks/. [...] In the case of road graphs we have chosen several smaller benchmarks made available during the 9th DIMACS challenge (Demetrescu et al., 2009).
Dataset Splits Yes To measure the query performance we run 10^8 random queries with source and target nodes picked uniformly at random and average their running times.
Hardware Specification Yes Our experiments were performed on a quad core i7-3770 CPU @ 3.40GHz with 8MB of combined cache, 8GB of RAM running Ubuntu 13.10. All algorithms were compiled using g++ 4.8.1 with -O3. All reported query times use a single core. [...] These experiments were carried out on a Xeon E5-2690 @ 2.90 GHz. [...] The ost100d and The Frozen Sea preprocessing experiments were run on an AMD Opteron 6172 with 48 cores @ 2.1 GHz to accelerate the APSP computation.
Software Dependencies Yes All algorithms were compiled using g++ 4.8.1 with -O3.
Experiment Setup Yes To measure the query performance we run 10^8 random queries with source and target nodes picked uniformly at random and average their running times. [...] We required node IDs to be encodable in 28 bits and out-edge IDs in 4 bits. We encode each run’s start in the upper 28 bits of a 32-bit machine word and its value in the lower 4 bits.