According to Clark's seminal work on common ground and grounding, participants collaborating in a joint activity rely on their shared information, known as common ground, to perform that activity successfully, and continually align and augment this information during their collaboration. Similarly, teams of human and artificial agents require common ground to successfully participate in joint activities. Indeed, without appropriate information being shared, using agent autonomy to reduce the workload on humans may actually increase workload as the humans seek to understand why the agents are behaving as they are. While many researchers have identified the importance of common ground in artificial intelligence, there is no precise definition of common ground on which to build the foundational aspects of multi-agent collaboration. In this paper, building on previously-defined modal logics of belief, we present logic definitions for four different types of common ground. We define modal logics for three existing notions of common ground and introduce a new notion of common ground, called salient common ground. Salient common ground captures the common ground of a group participating in an activity and is based on the common ground that arises from that activity as well as on the common ground they shared prior to the activity. We show that the four definitions share some properties, and our analysis suggests possible refinements of the existing informal and semi-formal definitions.

A pilot prepares to launch an unmanned aerial vehicle from a ground control station earlier this year. The Air Force is moving to treat psychological stress faced by remote pilots and analysts a little more like the effects of traditional warfare. A pilot prepares to launch an unmanned aerial vehicle from a ground control station earlier this year. The Air Force is moving to treat psychological stress faced by remote pilots and analysts a little more like the effects of traditional warfare. Kimi wanted to go to art school, but she didn't have the money.

Though still in its infancy, artificial intelligence already is changing the world. However, it's not just about what the technology itself can do, but what it enables people to do -- what new doors it can open. AI presents government agencies with new opportunities to innovate that previously may have been impossible. AI is an umbrella term that encompasses a variety of capabilities that allow computer systems to perform tasks normally done by humans. Many people also are familiar with the term "cognitive computing." Cognitive leverages several AI components, such as machine learning, to understand, reason, learn and interact with humans naturally.

The UK government has revealed that it will invest a further £38m in driverless cars, as part of a £1bn investment in'cutting-edge' technologies - all announced in the same week that the government declared a general election for June. Business secretary Greg Clark announced that the Industrial Strategy Challenge Fund (ISCF) would commit more than £1bn in taxpayers' money over the next four years to six key areas: Three of the areas - healthcare, energy, and robotics and AI, were announced in the 2017 Spring Budget - but Clark has now confirmed the total investment in each field, subject to business case approval. Robotics and AI will receive an investment of £93m. The government claimed that this would help "make industry and public services more productive by developing AI and robotics systems that can be deployed in extreme environments which occur in off-shore energy, nuclear energy, space and deep mining". Healthcare will get £197m to develop what the government called "first of a kind technologies for the manufacture of medicines that will speed up patient access to new drugs and treatments", while £246m will be spent on developing clean and flexible energy.

Apple has hired three engineers who previously worked at NASA's Jet Propulsion Laboratory and an engineer who worked on the space agency's autonomous vehicle for exploration on Jupiter's moon. The engineers reportedly will work on the company's self-driving venture, said the Wall Street Journal, which obtained documents related to the company's autonmous vehicle plan. The NASA engineers, who will test Apple's self-driving car software, have previously worked on detection of 3D objects and motion planning algorithms. Read: Are Self-Driving Cars Safe? One In Four Cars On U.S. Roads In 2035 Will Be Self-Driven, Study Says One of the engineers Apple hired had previously worked with German company Bosch during the firm's efforts to make a self-driving car and making autonomous wheelchairs travel more smoothly.

A.I. takes our Starbucks orders, drives Uber cars, curates our Facebook newsfeeds and pilots unmanned military drones. This year A.I. will write more than half of financial and sports stories. It already writes computer code and has the capability to learn. Would you trust robots to make life and death decisions? How fast will intelligent machines replace people?

Over the years, I've been asked what I like best about my job. Since I spent the majority of my career in the public sector, one top answer is that I love the challenge of helping organizations with security solutions and enabling new technologies to help the business of government. I also enjoy learning and sharing what works and doesn't work in different contexts. This sharing works out in press interviews or speeches on cyberthreats, I really enjoy moderating panels and leading executive roundtables with public- and private-sector leaders at security and technology events. I often get asked to be a moderator for a few sessions at SecureWorld Expo events, InfraGard Conferences and regional technology forums, such as the upcoming MidWest Technology Leaders event. During these panel sessions, the participants typically talk about a range of (hopefully intriguing) topics that include top cybercrime trends, cyberthreat intelligence, attracting and retaining cybertalent, big industry security breaches, internal security incidents or the always interesting (but overused question) "what's keeping you up at night?" Inevitably, security and technology topics include well known themes that I have written about such as ransomware, IoT botnets, cloud computing, smart cities, smartphone security, government CISO plans, securing the smart grid, end-user training, etc. Hopefully, we get beyond the problems and spend a few minutes on solutions.

Instead of new bank holidays for each of the nations of the UK to coincide with saints' days (as proposed by Labour), why not make national elections a public holiday as in many other countries? This would help to make it as easy for many people in employment to vote, as it is for people who are retired or not in work. Alternatively, voting should take place at weekends, thereby avoiding disruption to schools. Improving turnout and making the voting process just as convenient for everyone would be a step towards a healthier democracy. At what point in this progress towards robots taking over everyone's job and leaving them without employment or, more crucially, income is someone going to notice that demand is falling off so precipitously for the goods and services that the robots have been producing (because not enough people can afford them any more) that the robots themselves are becoming redundant?

When an Icelander arrives at an office building and sees'Solarfri' posted, they need no further explanation for the empty premises: The word means'when staff get an unexpected afternoon off to enjoy good weather.' The people of this rugged North Atlantic island settled by Norsemen some 1,100 years ago have a unique dialect of Old Norse that has adapted to life at the edge of the Artic. Hundslappadrifa, for example, means'heavy snowfall with large flakes occurring in calm wind.' Linguistics experts wonder if this is the beginning of the end for the Icelandic tongue. Salome Sigurjonsdottir, 10, tests a voice-controlled television in an electronics store in Reykjavik. Linguistics experts, studying the future of a language spoken by fewer than 400,000 people in an increasingly globalized world, wonder if this is the beginning of the end for the Icelandic tongue.

Sitting in the Oval Office Monday, President Trump spoke with two American astronauts currently living aboard the International Space Station. Trump, flanked by astronaut Kate Rubens and daughter Ivanka Trump, did a brief Q&A with NASA's Peggy Whitson, who just broke the record for the American who has spent the most days in space, and Jack Fischer, a new arrival to the space station. 'Better you than me,' Trump told the astronauts, when they talked about some of the things they have to do to live in space, such as turning their own urine into drinking water. The president, who signed a NASA bill last month with the aim of sending people to Mars, asked the astronauts when the trip was planned. 'I think, as your bill directed, it will be in the 2030s,' Whitson said.