Combinatorial worlds can be used to give an account of necessity and possibility. Both accessibility and similarity between worlds can be deened. In this paper, we claim that combinatorial worlds can form a knowledge representation framework, and provide an interesting approach to nonmonotonic reasoning and belief revision. We investigate such aspects of the combinatorial worlds framework as co...

The Resource Public Key Infrastructure (RPKI) has been introduced as a way of authorizing Border Gateway Protocol (BGP) route announcements. The highly centralized structure of the RPKI provides security guarantees against external threats, e.g. prefix hijacking, but allows for the unilateral revocation of allocated resources. Recent efforts propose changes to the RPKI to create accountability ...

A "Schrodinger cat"-like state of matter was generated at the single atom level. A trapped 9Be+ ion was laser-cooled to the zero-point energy and then prepared in a superposition of spatially separated coherent harmonic oscillator states. This state was created by application of a sequence of laser pulses, which entangles internal (electronic) and external (motional) states of the ion. The Schr...

In this paper, we describe an approach to artificial life, which uses Qualitative Reasoning for the simulation of life within a 3D virtual environment. This system uses qualitative formalisms to describe both the physiology of a virtual creature and its environment. This approach has two main advantages: the possibility of representing integrated physiological functions at various levels of abs...

New Worlds Observer is an external starshade mission designed to observe Earth-like planets around nearby stars. A telescope spacecraft operates in the “shadow” cast by a starshade spacecraft, located tens of thousands of kilometers away. We explore the requirements that these two free-flying spacecraft place on the orbital, propulsion, control, and communication systems and some baseline solut...

The realistic animation of animal behavior by autonomous animate agents requires that the agents able to perceive their virtual worlds. We have created a virtual marine world inhabited by artiicial shes which can swim hydrody-namically in simulated water through the motor control of internal muscles. Artiicial shes exploit a rudimentary model of sh perception. Complex individual and group behav...

Real-time video games are a unique domain for pathfinding and search. Traditional approaches to search have usually assumed static worlds with a single agent. But, in real-time video games there are multiple cooperative and adversarial agents. While the search space in most games is relatively small, algorithms are expected to plan in mere milliseconds. Thus, techniques such as abstraction are ...

est of the reader, he or she should consult the outside texts provided at the end of each chapter for more detailed information. With the arrival of the third edition comes the addition of current issues facing gender equality activists. The reader may find many of these fiercely debated topics familiar, thus establishing a connection between current events and the underlying theory discussed i...