scholarly journals Bringing Multi-agent Path Finding Closer to Reality

Author(s):  
Jiří Švancara

Multi-agent path finding is the problem of navigating multiple agents from their current locations to their goal locations in such a way that there are no collisions between the agents. The classical definition of the problem assumes that the set of agents is unchangeable, and that the distances in the graph are homogeneous. We propose to add to the problem specification a set of new attributes to bring it closer to the real world. These attributes include varying distances, number of agents that can occupy an edge or node, and dynamic appearance of new agents.

10.29007/cnzw ◽  
2019 ◽  
Author(s):  
Aysu Bogatarkan ◽  
Volkan Patoglu ◽  
Esra Erdem

The multi-agent path finding (MAPF) problem is a combinatorial search problem that aims at finding paths for multiple agents such that no two agents collide with each other. We study a dynamic variant of MAPF, called D-MAPF, which allows changes in the environment (e.g., some existing obstacles may be removed from the environment or moved to some other location, or new obstacles may be included in the environment), and/or changes in the team (e.g., some existing agents may leave and some new agents may join the team) at different times. We introduce a new method to solve D-MAPF, using answer set programming.


2020 ◽  
pp. 95-98
Author(s):  
Philippe Rochat

Humans can’t help but generalize in ways that are rarely, if ever, dictated by reason and prudence. We jump quickly to confirmatory and reassuring conclusions with a propensity to invent things in reference to worlds that only exist in our minds. Rather than being just games of the imagination, these inventions actually influence, often unbeknownst to us (subliminally), our attitudes and actions in the real world, in particular our discriminatory attitudes and actions toward people. Our innate propensity to chunk, cluster, and categorize things corresponds with our propensity to reproduce patterns of reality that are constructed based on ready-made or default implicit beliefs (i.e., stereotyping). Furthermore, the built-in default assumption that things and people have essential, nonobvious characteristics (definition of essentialism) allows for the immediate experience of favorable or unfavorable feelings toward people or things prior to, or not based on, actual experience (i.e. the definition of prejudice).


Author(s):  
Y. Yongling

Geographical information system (GIS) is one kind of information system that handles spatial data. It is difficult to give one definitive definition about GIS (Heywood, Cornelius, & Carver, 2002; Maguire, Goodchild, & Rhind, 2001). This variety of definitions can be explained by the fact that any definition of GIS will depend on who is giving it, and their background and viewpoint (Pinkles, 2002). The complete definition of GIS is selected here as: “a set of tools for collecting, storing, retrieving at will, transforming, and displaying spatial data from the real world for a particular set of purposes”(Burrough, 1986, p. 6). As an important part of e-government, is that it has functions of cartography, manages spatial data and spatial analysis.


Aerospace ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 48
Author(s):  
Konstantine Fines ◽  
Alexei Sharpanskykh ◽  
Matthieu Vert

Airport surface movement operations are complex processes with many types of adverse events which require resilient, safe, and efficient responses. One regularly occurring adverse event is that of runway reconfiguration. Agent-based distributed planning and coordination has shown promising results in controlling operations in complex systems, especially during disturbances. In contrast to the centralised approaches, distributed planning is performed by several agents, which coordinate plans with each other. This research evaluates the contribution of agent-based distributed planning and coordination to the resilience of airport surface movement operations when runway reconfigurations occur. An autonomous Multi-Agent System (MAS) model was created based on the layout and airport surface movement operations of Schiphol Airport in the Netherlands. Within the MAS model, three distributed planning and coordination mechanisms were incorporated, based on the Conflict-Based Search (CBS) Multi-Agent Path Finding (MAPF) algorithm and adaptive highways. MAS simulations were run based on eight days of real-world operational data from Schiphol Airport and the results of the autonomous MAS simulations were compared to the performance of the real-world human operated system. The MAS results show that the distributed planning and coordination mechanisms were effective in contributing to the resilient behaviour of the airport surface movement operations, closely following the real-world behaviour, and sometimes even surpassing it. In particular, the mechanisms were found to contribute to more resilient behaviour than the real-world when considering the taxi time after runway reconfiguration events. Finally, the highway included distributed planning and coordination mechanisms contributed to the most resilient behaviour of the airport surface movement operations.


Author(s):  
Rajiv T. Maheswaran ◽  
Craig M. Rogers ◽  
Romeo Sanchez ◽  
Pedro Szekely ◽  
Robert Neches

2019 ◽  
Vol 3 (1) ◽  
pp. 13-22
Author(s):  
Bijan Bidabad ◽  
Behrouz Bidabad

This note discusses the existence of "complex probability" in the real world sensible problems. By defining a measure more general than the conventional definition of probability, the transition probability matrix of discrete Markov chain is broken to the periods shorter than a complete step of the transition. In this regard, the complex probability is implied.


Author(s):  
Matteo Casu ◽  
Luca Albergante

The notion of identity has been discussed extensively in the past. Leibniz was the first to present this notion in a logically coherent way, using a formulation generally recognized as “Leibniz's Law”. Although some authors criticized this formulation, Leibniz's Law is generally accepted as the definition of identity. This work interprets Leibniz's Law as a limit notion: perfectly reasonable in a <i>God's eye</i> view of reality, but very difficult to use in the real world because of the limitedness of finite agents. To illustrate our approach we use “description logics” to describe the properties of objects, and present an approach to relativize Leibniz's Law. This relativization is further developed in a semantic web context, where the utility of our approach is suggested.


Author(s):  
Jiaoyang Li ◽  
Pavel Surynek ◽  
Ariel Felner ◽  
Hang Ma ◽  
T. K. Satish Kumar ◽  
...  

Multi-Agent Path Finding (MAPF) has been widely studied in the AI community. For example, Conflict-Based Search (CBS) is a state-of-the-art MAPF algorithm based on a twolevel tree-search. However, previous MAPF algorithms assume that an agent occupies only a single location at any given time, e.g., a single cell in a grid. This limits their applicability in many real-world domains that have geometric agents in lieu of point agents. Geometric agents are referred to as “large” agents because they can occupy multiple points at the same time. In this paper, we formalize and study LAMAPF, i.e., MAPF for large agents. We first show how CBS can be adapted to solve LA-MAPF. We then present a generalized version of CBS, called Multi-Constraint CBS (MCCBS), that adds multiple constraints (instead of one constraint) for an agent when it generates a high-level search node. We introduce three different approaches to choose such constraints as well as an approach to compute admissible heuristics for the high-level search. Experimental results show that all MC-CBS variants outperform CBS by up to three orders of magnitude in terms of runtime. The best variant also outperforms EPEA* (a state-of-the-art A*-based MAPF solver) in all cases and MDD-SAT (a state-of-the-art reduction-based MAPF solver) in some cases.


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