19,778 research outputs found
Asynchronous approach in the plane: A deterministic polynomial algorithm
In this paper we study the task of approach of two mobile agents having the
same limited range of vision and moving asynchronously in the plane. This task
consists in getting them in finite time within each other's range of vision.
The agents execute the same deterministic algorithm and are assumed to have a
compass showing the cardinal directions as well as a unit measure. On the other
hand, they do not share any global coordinates system (like GPS), cannot
communicate and have distinct labels. Each agent knows its label but does not
know the label of the other agent or the initial position of the other agent
relative to its own. The route of an agent is a sequence of segments that are
subsequently traversed in order to achieve approach. For each agent, the
computation of its route depends only on its algorithm and its label. An
adversary chooses the initial positions of both agents in the plane and
controls the way each of them moves along every segment of the routes, in
particular by arbitrarily varying the speeds of the agents. A deterministic
approach algorithm is a deterministic algorithm that always allows two agents
with any distinct labels to solve the task of approach regardless of the
choices and the behavior of the adversary. The cost of a complete execution of
an approach algorithm is the length of both parts of route travelled by the
agents until approach is completed. Let and be the initial
distance separating the agents and the length of the shortest label,
respectively. Assuming that and are unknown to both agents, does
there exist a deterministic approach algorithm always working at a cost that is
polynomial in and ? In this paper, we provide a positive answer to
the above question by designing such an algorithm
Learning Interpretable Spatial Operations in a Rich 3D Blocks World
In this paper, we study the problem of mapping natural language instructions
to complex spatial actions in a 3D blocks world. We first introduce a new
dataset that pairs complex 3D spatial operations to rich natural language
descriptions that require complex spatial and pragmatic interpretations such as
"mirroring", "twisting", and "balancing". This dataset, built on the simulation
environment of Bisk, Yuret, and Marcu (2016), attains language that is
significantly richer and more complex, while also doubling the size of the
original dataset in the 2D environment with 100 new world configurations and
250,000 tokens. In addition, we propose a new neural architecture that achieves
competitive results while automatically discovering an inventory of
interpretable spatial operations (Figure 5)Comment: AAAI 201
Navigating Your Way! Increasing the Freedom of Choice During Wayfinding
Using navigation assistance systems has become widespread and scholars have tried to mitigate potentially adverse effects on spatial cognition these systems may have due to the division of attention they require. In order to nudge the user to engage more with the environment, we propose a novel navigation paradigm called Free Choice Navigation balancing the number of free choices, route length and number of instructions given. We test the viability of this approach by means of an agent-based simulation for three different cities. Environmental spatial abilities and spatial confidence are the two most important modeled features of our agents. Our results are very promising: Agents could decide freely at more than 50% of all junctions. More than 90% of the agents reached their destination within an average distance of about 125% shortest path length
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