Constructing an appropriate model is crucial in reasoning successfully about the behavior of a physical situation to answer a query. In compositional modeling, a system is provided with a library of composible pieces of knowledge about the physical world called model fragments. Its task is to select appropriate model fragments to describe the situation, either for static analysis of a single state, or for the more complicated case simulation of dynamic behavior over a sequence of states. In previous work we showed how the model construction problem in general can advantageously be formulated as a problem of reasoning about relevance. This paper presents an actual algorithm, based on relevance reasoning, for selecting model fragments efficiently for the case of simulation. We show that the algorithm produces an adequate model for a given query and moreover, it is the simplest one given the constraints in the query.
In this digital era, data breaches can come at any time and from any direction. The all too often result is an organization and its crisis team struggling to coordinate ongoing speedy and effective responses. Take the Target data breach of a few years ago, for example. After Target's IT systems had been hacked, exposing the personal data of up to 110 million customers, Target issued a statement the following day and posted a video with more details on its website. The company apologized, explained how the hack had happened, and offered free credit monitoring for affected customers.
The EU will "not be intimidated" by threats about the UK leaving with no deal, Donald Tusk has said. He said suggestions the UK would be better off leaving with no deal, rather than with a bad deal, "increasingly take the form of a threat". The European Council president told the European Parliament that in the Brexit talks "a no deal scenario would be bad for everyone but above all for the UK". He said the "goal is a smooth divorce" with the UK and EU as "good friends". Mr Tusk made the remarks at the last meeting of the European Parliament before the UK triggers Article 50, which kick-starts Britain's withdrawal from the EU and is expected to happen later this month.
Most of the current internet infrastructure in the U.S. was built in the 1990s and 2000s to serve major population centers on the coasts. As new connections were built, companies built them alongside roads and railroads, which often hug coastlines. Recent mapping of the physical internet by computer scientists Paul Barford and Ram Durairajan identified exactly how many key network locations are close to the shore. Building on that work, I joined them to study the risk to the internet from rising oceans. The basic approach was simple: Take the map of internet hardware and line it up with a map of projected sea-level rise to see where network infrastructure may be underwater in the coming years.