Learning Multirobot Hose Transportation and Deployment by Distributed Round-Robin Q-Learning

Multi-Agent Reinforcement Learning (MARL) algorithms face two main difficulties: the curse of dimensionality, and environment non-stationarity due to the independent learning processes carried out by the agents concurrently. In this paper we formalize and prove the convergence of a Distributed Round Robin Q-learning (D-RR-QL) algorithm for cooperative systems. The computational complexity of this algorithm increases linearly with the number of agents. Moreover, it eliminates environment non sta tionarity by carrying a round-robin scheduling of the action selection and execution. That this learning scheme allows the implementation of Modular State-Action Vetoes (MSAV) in cooperative multi-agent systems, which speeds up learning convergence in over-constrained systems by vetoing state-action pairs which lead to undesired termination states (UTS) in the relevant state-action subspace. Each agent's local state-action value function learning is an independent process, including the MSAV policies. Coordination of locally optimal policies to obtain the global optimal joint policy is achieved by a greedy selection procedure using message passing. We show that D-RR-QL improves over state-of-the-art approaches, such as Distributed Q-Learning, Team Q-Learning and Coordinated Reinforcement Learning in a paradigmatic Linked Multi-Component Robotic System (L-MCRS) control problem: the hose transportation task. L-MCRS are over-constrained systems with many UTS induced by the interaction of the passive linking element and the active mobile robots.

Constitution and By-Laws of the Citizens' Hose Company

Constitution and By-laws of the Citizens’ Hose Company is a 12 page 14 cm. x 9 ½ cm. booklet. The booklet is slightly discoloured and has had some water damage. This does not affect the text, Aug. 1, 1871.

Roll Call for Fires and Alarms for Citizens' Hose Company No. 1

Roll call for fires and alarms for Citizens’ Hose Company No. 1. (1 double sided printed page). H.K. Woodruff is listed as a member, 1883.

Model to design drip hose lateral line using two spacing between emitters

The use of non-pressure compensating drip hose in horticultural and annual cycle fruits is growing in Brazil. In this case, the challenge for designers is getting longer lateral lines with high values of uniformity. The objective of this study was to develop a model to design longer lateral lines using non-pressure compensating drip hose. Using the developed model, the hypotheses to be evaluated were: a) the use of two different spacing between emitters in the same lateral line allows longer length; b) it is possible to get longer lateral lines using high values of pressure variation in the lateral lines since the distribution uniformity stays below allowable limits. A computer program was developed in Delphi based on the model developed and it is able to design lateral lines in level using non-pressure compensating drip hose. The input data are: desired distribution uniformity (DU); initial and final pressure in the lateral line; coefficients of relationship between emitter discharge and pressure head; hose internal diameter; pipe cross-sectional area with the dripper; and roughness coefficient for the Hazen-Williams equation. The program allows calculate the lateral line length with three possibilities: selecting two spacing between emitters and defining the exchange point; using two pre-established spacing between emitters and calculating the length of each section with different spacing; using one emitter spacing. Results showed that the use of two sections with different spacing between drippers in the lateral line didn't allow longer length but got better uniformity when compared with lateral line with one spacing between emitters. The adoption of two spacing increased the flow rate per meter in the final section which represented approximately 80% of the lateral line total length and this justifies their use. The software allowed DU above 90% with pressure head variation of 40% and the use of two spacing between emitters. The developed model/software showed to be accurate, easy to handle and useful for lateral line design using non-pressure compensating drip hose.

Lynch law in Georgia : a six-weeks' record in the center of southern civilization, as faithfully chronicled by the Atlanta Journal and the Atlanta Constitution : also the full report of Louis P. Le Vin, the Chicago detective sent to investigate the burning of Samuel Hose, the torture and hanging of Elijah Strickland, the colored preacher, and the lynching of nine men for alleged arson /

"June 20, 1899"--P. [1].

Evaluation of hose-end sprayers used for applying liquid pesticides /

Mode of access: Internet.

United States government master specification for hose, oil suction and discharge.

At head of title: Department of Commerce. Bureau of Standards.

Die Hose, ein bürgerliches Lustspiel.

Mode of access: Internet.

Hydraulic experiments with valves, orifices, hose, nozzles, and orifice buckets.

Mode of access: Internet.