This paper introduces two algorithms (both actually are variants of a single algorithm)—the First price Upper Bound, FUB, and Second price Lower Bound, SeLB, algorithms—aimed at serving as subroutines in computationally efficient algorithms for combinatorial auctions. The type of combinatorial auctions treated in the paper are the once where bids are placed on one unit of one or more items at a...

The United States, uniquely among all countries, elects its head of state using a two-tiered system called the Electoral College. If we view the states that make up the Electoral College as voters and make some simplifying assumptions, it is possible to use the theory of voting and voting power to measure the power of the individual states in a presidential election. Modeling the Electoral Coll...

The POSSIBLE WINNER problem asks, given an election where the voters’ preferences over the candidates are specified only partially, whether a designated candidate can become a winner by suitably extending all the votes. Betzler and Dorn [1] proved a result that is only one step away from a full dichotomy of this problem for the important class of pure scoring rules in the case of unweighted vot...

Prior work on the complexity of bribery assumes that happens simultaneously, and briber has full knowledge all votes. However, in many real-world settings votes come sequentially, may have a use-it-or-lose-it moment to decide whether alter given vote, when making decision not know what remaining voters will cast. We introduce model for, initiate study of, such an online, sequential setting. sho...

Multi-item, multi-unit negotiations in industrial procurement pose serious challenges to buying agents when trying to determine the best set of providering agents’ offers. Typically, a buying agent’s decision involves a large variety of constraints that may involve attributes of separate items as well as attributes of different, multiple items. In this paper we present Ibundler, an agent-based ...

The "kill the winner" hypothesis is an attempt to address the problem of diversity in biology. It argues that host-specific predators control the population of each prey, preventing a winner from emerging and thus maintaining the coexistence of all species in the system. We develop a stochastic model for the kill the winner paradigm and show that the stable coexistence state of the deterministi...

Combinatorial auctions address the fundamental problem of allocating multiple items in the presence of complex bidder preferences including complements or substitutes. They have found application in public and private sector auctions. Many real-world markets involve the sale of a large number of items, limiting the direct application of combinatorial auctions due to both computational intractab...

Schulze’s rule is used in the elections of a large number of organizations including Wikimedia and Debian. Part of the reason for its popularity is the large number of axiomatic properties, like monotonicity and Condorcet consistency, which it satisfies. We identify a potential shortcoming of Schulze’s rule: it is computationally vulnerable to manipulation. In particular, we prove that computin...

Maximum weight clique and maximum weight independent set solvers are often benchmarked using maximum clique problem instances, with weights allocated to vertices by taking the vertex number mod 200 plus 1. For constraint programming approaches, this rule has clear implications, favouring weight-based rather than degree-based heuristics. We show that similar implications hold for dedicated algor...

While voting systems were originally used in political science, they are now also of central importance in various areas of computer science, such as artificial intelligence (in particular within multiagent systems). Brams and Sanver [BS06] introduced sincere-strategy preference-based approval voting (SP-AV) and fallback voting (FV), two election systems which combine the preference rankings of...