Participatory budgeting enables the allocation of public funds by collecting and aggregating individual preferences; it has already had a sizable real-world impact. But making the most of this new paradigm requires a rethinking of some of the basics of computational social choice, including the very way in which individuals express their preferences. We analytically compare four preference elicitation methods -- knapsack votes, rankings by value or value for money, and threshold approval votes -- through the lens of implicit utilitarian voting, and find that threshold approval votes are qualitatively superior. This conclusion is supported by experiments using data from real participatory budgeting elections.

In the Colonel Blotto game, which was initially introduced by Borel in 1921, two colonels simultaneously distribute their troops across different battlefields.The winner of each battlefield is determined independently by a winner-take-all rule. The ultimate payoff of each colonel is the number of battlefields he wins. This game is commonly used for analyzing a wide range of applications such as the U.S presidential election, innovative technology competitions, advertisements, etc. There have been persistent efforts for finding the optimal strategies for the Colonel Blotto game. After almost a century Ahmadinejad, Dehghani, Hajiaghayi, Lucier, Mahini, and Seddighin provided a poly-time algorithm for finding the optimal strategies. They first model the problem by a Linear Program (LP) with exponential number of constraints and use Ellipsoid method to solve it. However, despite the theoretical importance of their algorithm, it ishighly impractical. In general, even Simplex method (despite its exponential running-time) performs better than Ellipsoid method in practice. In this paper, we provide the first polynomial-size LP formulation of the optimal strategies for the Colonel Blotto game. We use linear extension techniques. Roughly speaking, we project the strategy space polytope to a higher dimensional space, which results in a lower number of facets for the polytope.We use this polynomial-size LP to provide a novel, simpler and significantly faster algorithm for finding the optimal strategies for the Colonel Blotto game. We further show this representation is asymptotically tight in terms of the number of constraints. We also extend our approach to multi-dimensional Colonel Blotto games, and implement our algorithm to observe interesting properties of Colonel Blotto; for example, we observe the behavior of players in the discrete model is very similar to the previously studied continuous model.

We introduce a new class of mechanisms, robust mechanisms, that is an intermediary between ex-post mechanisms and Bayesian mechanisms. This new class of mechanisms allows the mechanism designer to incorporate imprecise estimates of the distribution over bidder valuations in a way that provides strong guarantees that the mechanism will perform at least as well as ex-post mechanisms, while in many cases performing better. We further extend this class to mechanisms that are with high probability incentive compatible and individually rational, ε-robust mechanisms. Using techniques from automated mechanism design and robust optimization, we provide an algorithm polynomial in the number of bidder types to design robust and ε-robust mechanisms. We show experimentally that this new class of mechanisms can significantly outperform traditional mechanism design techniques when the mechanism designer has an estimate of the distribution and the bidder’s valuation is correlated with an externally verifiable signal.

Fact checking is an essential part of any investigative work. For linguistic, psychological and social reasons, it is an inherently human task. Yet, modern media make it increasingly difficult for experts to keep up with the pace at which information is produced. Hence, we believe there is value in tools to assist them in this process. Much of the effort on Web data research has been focused on coping with incompleteness and uncertainty. Comparatively, dealing with context has received less attention, although it is crucial in judging the validity of a claim. For instance, what holds true in a US state, might not in its neighbors, e.g., due to obsolete or superseded laws. In this work, we address the problem of checking the validity of claims in multiple contexts. We define a language to represent and query facts across different dimensions. The approach is non-intrusive and allows relatively easy modeling, while capturing incompleteness and uncertainty. We describe the syntax and semantics of the language. We present algorithms to demonstrate its feasibility, and we illustrate its usefulness through examples.

Public opinion polling is usually done by random sampling from the entire population, treating individual opinions as independent. In the real world, individuals' opinions are often correlated, e.g., among friends in a social network. In this paper, we explore the idea of partitioned sampling, which partitions individuals with high opinion similarities into groups and then samples every group separately to obtain an accurate estimate of the population opinion. We rigorously formulate the above idea as an optimization problem. We then show that the simple partitions which contain only one sample in each group are always better, and reduce finding the optimal simple partition to a well-studied Min-r-Partition problem. We adapt an approximation algorithm and a heuristic algorithm to solve the optimization problem. Moreover, to obtain opinion similarity efficiently, we adapt a well-known opinion evolution model to characterize social interactions, and provide an exact computation of opinion similarities based on the model. We use both synthetic and real-world datasets to demonstrate that the partitioned sampling method results in significant improvement in sampling quality and it is robust when some opinion similarities are inaccurate or even missing.

MOSCOW/UNITED NATIONS – Russia released drone footage Monday showing new destruction in Syria's historic town of Palmyra, which was recently recaptured by the Islamic State group, and warned that the militants could be planning the further demolition of antiquities. The Russian Defense Ministry says Syrian government forces are advancing toward the town as another battle for the ancient site looms. The video showed that the militants have badly damaged the facade of the Roman-era amphitheater and the Tetrapylon -- a set of four monuments with four columns each at the center of the colonnaded road leading to the theater. The video appears to show that only two of the 16 columns remain standing. IS militants have destroyed ancient sites across their self-styled Islamic caliphate in Syria and Iraq, perceiving them as monuments to idolatry.

It has animal hairs coated with ionic liquid gel to pollinate a flower like a bee. They may be small, but bees and other insects play a critical role in pollination and maintaining a natural balance in our environment. On February 10, 2017, the U.S. Fish and Wildlife Service listed the rusty-patched bumblebee as an endangered species, now found in only 13 states. Bumblebees and other pollinating insects help pollinate 75 percent of the fruits, nuts, and vegetables we eat and removing them from the equation could trigger a global food crisis according to the United States Department of Agriculture (USDA). The short term solution could lie with drones.

That's the size of the workforce dedicated to a business that's thrived for the past three decades on a growth model of labour arbitrage. In the process, it's matured into a industry worth almost $150 billion. The multi-billion dollar question today is, where does it go from here, as it comes head to head with a series of challenges. Consider: New Bills being introduced by the Trump administration in the US Congress seek to make outsourcing not only tougher but more expensive. This comes at a time when protectionist sentiments that call for onsite hiring of locals are spreading globally. All this, even as traditional IT services are moving towards the digital economy.

In this week's This Feels A Little Like Skynet: IBM built a new voice assistant using artificial intelligence called Hayvn, focused on cybersecurity. Think of it as Amazon Alexa, but instead of ordering soap, it's helping you manage threats. Sure, this might sound like it's ripped straight out of the plot for Terminator 3: Rise of the Machines, in which the military unleashes a new AI called Skynet to fight a virus that's been disrupting worldwide networks. And yes, that AI then becomes sentient, launches nukes and begins "Judgement Day." Here in the real world, IBM said Hayvn is being used to help cybersecurity pros comb through the hundreds of alerts they receive each day.

Two senators said Monday that they're launching a bipartisan effort to help to speed up the deployment of self-driving cars on the nation's roads. It's the first major congressional attempt to address the advent of the vehicles. Sens. John Thune (R-S.D.), the chairman of the Senate Commerce, Science and Transportation Committee, and Gary Peters (D-Mich.) said they're exploring legislation that "clears hurdles and advances innovation in self-driving vehicle technology." The senators' counterparts in the House are also gearing up to address the new technology, with a hearing scheduled for Tuesday. Automakers cite federal requirements that all vehicles must have steering wheels and brake pedals as examples of regulations that presume there will be a human driver and might inhibit the introduction of self-driving cars.