Gutierrez and Meseguer show how to enforce consistency during distributed search in the BnB-ADOPT+ algorithm for distributed constraint optimization, but they consider only unconditional deletions. However, during search, more values can be pruned conditionally according to variable instantiations that define subproblems. Enforcing consistency in these subproblems can cause further search space reduction. Here we introduce methods to maintain soft arc consistencies in every subproblem during search. Difficulties lie in the asynchronicity of the algorithm and on the overheads induced by backtracking and undoing. After a careful implementation, experimental results show substantial benefits on several benchmarks.
Interoperability has been a challenging unsolved problem that relies on manual, error-prone solutions and costs billions of dollars annually geomintQ; geomintM . Semi-automated verification of interoperability can be achieved by a set of limited tools. However, there does not exist any automated tools for the verification and the validation of interoperability solutions. This work may enable the next generation of automatically composable and reconfigurable systems, and support formal verification of the currently used standards. In this article, we focus on the theoretical framework we built in on, and construct an algorithmic framework that can be used to apply the theory presented in on .
This note considers how to modify BnB-ADOPT, a well-known algorithm for optimally solving distributed constraint optimization problems, with a double aim: (i) to avoid sending most of the redundant messages and (ii) to handle cost functions of any arity. Some of the messages exchanged by BnB-ADOPT turned out to be redundant. Removing most of the redundant messages increases substantially communication efficiency: the number of exchanged messages is - in most cases - at least three times fewer (keeping the other measures almost unchanged), and termination and optimality are maintained. On the other hand, handling n-ary cost functions was addressed in the original work, but the presence of thresholds makes their practical usage more complex. Both issues - removing most of the redundant messages and efficiently handling n-ary cost functions - can be combined, producing the new version BnB-ADOPT+. Experimentally, we show the benefits of this version over the original one.
Eight countries have jointly proposed a set of "high-level principles" in the hope they can enable future mutual recognition and interoperability of digital identities. The countries came together to form the digital identity working group (DIWG) in 2020 to discuss how to make digital identity a key component of the global digital trade and travel ecosystem. The set of principles is the group's first set of publicly released work since inception. Chaired by Australia's Digital Transformation Agency, the working group's other members are from Canada, Finland, Israel, New Zealand, Singapore, the Netherlands, and the United Kingdom. There are 11 principles in total, all contained in a report [PDF] about digital identity in a COVID-19 environment, that the DIWG envisions would be used by all governments when building digital identity frameworks.