4 ms·

That’s the principal behind Fortescue’s infinity train: https://newatlas.com/transport/fortescue-wae-infinity-train-electric/ https://newatlas.com/transport/fo

• westurner 3y ago
  Regenerative braking in trains: https://www.google.com/search?q=regenerative+braking+trains https://www.google.com/search?q=regenerative+braking+trains Regenerative braking: https://en.wikipedia.org/wiki/Regenerative_braking https://en.wikipedia.org/wiki/Regenerative_braking From https://news.ycombinator.com/item?id=27579732 https://news.ycombinator.com/item?id=27579732 : > In Scandinavia the Kiruna to Narvik electrified railway [...] The regenerated energy is sufficient to power the empty trains back up to the national border Is re-planning routes for regenerative braking solvable with the Modified Snow Plow Problem (variation on TSP Traveling Salesman Problem), on a QC Quantum Computer; with Quantum Algorithmic advantage due to the complexity of the problem? From "Snow plow routing problem": https://en.wikipedia.org/wiki/Snow_plow_routing_problem https://en.wikipedia.org/wiki/Snow_plow_routing_problem : > The snow plow routing problem is an application of the structure of Arc Routing Problems (ARPs) and Vehicle Routing Problems (VRPs) to snow removal that considers roads as edges of a graph. > The problem is a simple routing problem when the arrival times are not specified.[1] Snow plow problems consider constraints such as the cost of plowing downhill compared to plowing uphill.[2] The Mixed Chinese Postman Problem is applicable to snow routes where directed edges represent one-way streets and undirected edges represent two-way streets. [3] Arc routing > Algorithms: https://en.wikipedia.org/wiki/Arc_routing#Algorithms https://en.wikipedia.org/wiki/Arc_routing#Algorithms : > Finding an efficient solution with large amounts data to the Chinese Postman Problem (CPP), the Windy Postman Problem (WPP), the Rural Postman Problem (RPP), the k-Chinese postman problem (KCPP), the mixed Chinese postman problem (MCPP), the Directed Chinese Postman Problem (DCPP),[8] the Downhill Plowing Problem (DPP), the Plowing with Precedence Problem (PPP), the Windy Rural Postman Problem (WRPP) and the Windy General Routing Problem (WGRP) requires using thoughtful mathematical concepts, including heuristic optimization methods, branch-and-bound methods, integer linear programming, and applications of traveling salesman problem algorithms such as the Held–Karp algorithm makes an improvement from O(n!) to O(2^{n}n^{2}).[9] In addition to these algorithms, these classes of problems can also be solved with the cutting plane algorithm, convex optimization, convex hulls, Lagrange multipliers and other dynamic programming methods. In cases where it is not feasible to run the Held–Karp algorithm because of its high computational complexity, algorithms like this can be used to approximate the solution in a reasonable amount of time.[10] QC algos for TSP and similar: - QISkit tutorials > Max-Cut and Traveling Salesman Problem: docs/tutorials/06_examples_max_cut_and_tsp.ipynb: https://qiskit.org/ecosystem/optimization/tutorials/06_examples_max_cut_and_tsp.html https://qiskit.org/ecosystem/optimization/tutorials/06_examp...