The travelling thief problem (TTP) is a combination of two interdependent NP-hard components: travelling salesman problem (TSP) and knapsack problem (KP). Existing approaches for TTP typically solve the TSP and KP components in an interleaved fashion, where the solution to one component is held fixed while the other component is changed. This indicates poor coordination between solving the two components and may lead to poor quality TTP solutions. For solving the TSP component, the 2-OPT segment reversing heuristic is often used for modifying the tour. We propose an extended and modified form of the reversing heuristic in order to concurrently consider both the TSP and KP components. Items deemed as less profitable and picked in cities earlier in the reversed segment are replaced by items that tend to be equally or more profitable and not picked in the later cities. Comparative evaluations on a broad range of benchmark TTP instances indicate that the proposed approach outperforms existing state-of-the-art TTP solvers.

The travelling thief problem (TTP) is a multi-component optimisation problem involving two interdependent NP-hard components: the travelling salesman problem (TSP) and the knapsack problem (KP). Recent state-of-the-art TTP solvers modify the underlying TSP and KP solutions in an iterative and interleaved fashion. The TSP solution (cyclic tour) is typically changed in a deterministic way, while changes to the KP solution typically involve a random search, effectively resulting in a quasi-meandering exploration of the TTP solution space. Once a plateau is reached, the iterative search of the TTP solution space is restarted by using a new initial TSP tour. We propose to make the search more efficient though an adaptive surrogate model (based on a customised form of Support Vector Regression) that learns the characteristics of initial TSP tours that lead to good TTP solutions.

Although investors scrambled--and shelled out up to $185,000 a pop--for the chance to snatch up the new domains and profit as gatekeepers, uptake among end-users has been underwhelming. More than three years after the program's launch, roughly 26 million new generic top-level domains have been registered, compared with the 164 million registered "legacy" top-level domains. Cyrus Namazi, the vice president of domain-name services and industry engagement at ICANN, acknowledged that demand for new top-level domains won't eclipse that for legacies "any time soon." Yet Namazi believes registrations for the new extensions will continue to grow. "We are in the embryonic stages of the expansion," he said.

DUBAI, United Arab Emirates – Hard-liners in Iran have released a video showing a detained Iranian-American businessman for the first time since his arrest last October. The minute-long video, posted Monday by Iran's judiciary news agency, shows Siamak Namazi amid a montage of clips, including an Iranian drone flying over a U.S. aircraft carrier and American sailors on their knees being detained in January. The video has no audio other than what sounds like a dramatic film score. It shows Namazi's U.S. passport, a United Arab Emirates ID card and a clip of him in a conference room, his arms raised at his sides. Namazi is a son of Baquer Namazi, a former UNICEF representative who once served as governor of Iran's oil-rich Khuzestan province under the U.S.-backed shah.