The dispersion problem has received much attention recently in the distributed computing literature. In this problem, $k\leq n$ agents placed initially arbitrarily on the nodes of an $n$-node, $m$-edge anonymous graph of maximum degree $\Delta$ have to reposition autonomously to reach a configuration in which each agent is on a distinct node of the graph. Dispersion is interesting as well as important due to its connections to many fundamental coordination problems by mobile agents on graphs, such as exploration, scattering, load balancing, relocation of self-driven electric cars (robots) to recharge stations (nodes), etc. The objective has been to provide a solution that optimizes simultaneously time and memory complexities. There exist graphs for which the lower bound on time complexity is $\Omega(k)$. Memory complexity is $\Omega(\log k)$ per agent independent of graph topology. The state-of-the-art algorithms have (i) time complexity $O(k\log^2k)$ and memory complexity $O(\log(k+\Delta))$ under the synchronous setting [DISC'24] and (ii) time complexity $O(\min\{m,k\Delta\})$ and memory complexity $O(\log(k+\Delta))$ under the asynchronous setting [OPODIS'21]. In this paper, we improve substantially on this state-of-the-art. Under the synchronous setting as in [DISC'24], we present the first optimal $O(k)$ time algorithm keeping memory complexity $O(\log (k+\Delta))$. Under the asynchronous setting as in [OPODIS'21], we present the first algorithm with time complexity $O(k\log k)$ keeping memory complexity $O(\log (k+\Delta))$, which is time-optimal within an $O(\log k)$ factor despite asynchrony. Both results were obtained through novel techniques to quickly find empty nodes to settle agents, which may be of independent interest.

In the real world, knowledge is constantly evolving, which can render existing knowledge-based datasets outdated. This unreliability highlights the critical need for continuous updates to ensure both accuracy and relevance in knowledge-intensive tasks. To address this, we propose GrowOVER-QA and GrowOVER-Dialogue, dynamic open-domain QA and dialogue benchmarks that undergo a continuous cycle of updates, keeping pace with the rapid evolution of knowledge. Our research indicates that retrieval-augmented language models (RaLMs) struggle with knowledge that has not been trained on or recently updated. Consequently, we introduce a novel retrieval-interactive language model framework, where the language model evaluates and reflects on its answers for further re-retrieval. Our exhaustive experiments demonstrate that our training-free framework significantly improves upon existing methods, performing comparably to or even surpassing continuously trained language models.

Consider that there are $k\le n$ agents in a simple, connected, and undirected graph $G=(V,E)$ with $n$ nodes and $m$ edges. The goal of the dispersion problem is to move these $k$ agents to distinct nodes. Agents can communicate only when they are at the same node, and no other means of communication such as whiteboards are available. We assume that the agents operate synchronously. We consider two scenarios: when all agents are initially located at any single node (rooted setting) and when they are initially distributed over any one or more nodes (general setting). Kshemkalyani and Sharma presented a dispersion algorithm for the general setting, which uses $O(m_k)$ time and $\log(k+\delta)$ bits of memory per agent [OPODIS 2021]. Here, $m_k$ is the maximum number of edges in any induced subgraph of $G$ with $k$ nodes, and $\delta$ is the maximum degree of $G$. This algorithm is the fastest in the literature, as no algorithm with $o(m_k)$ time has been discovered even for the rooted setting. In this paper, we present faster algorithms for both the rooted and general settings. First, we present an algorithm for the rooted setting that solves the dispersion problem in $O(k\log \min(k,\delta))=O(k\log k)$ time using $O(\log \delta)$ bits of memory per agent. Next, we propose an algorithm for the general setting that achieves dispersion in $O(k (\log k)\cdot (\log \min(k,\delta))=O(k \log^2 k)$ time using $O(\log (k+\delta))$ bits. Finally, for the rooted setting, we give a time-optimal, i.e.,$O(k)$-time, algorithm with $O(\delta)$ bits of space per agent.

It is easy to get distracted by US officials pledging to rally support for a "humanitarian pause" and reducing the number of civilian casualties in Israel's bombardment of Gaza. But what matters is the actions of the Biden administration, not empty platitudes. In early November, the US State Department approved a $320m sale of guided bomb kits, reportedly assisting Israel to more precisely hit targets in Gaza. According to The New York Times, "Modern militaries generally add the guidance systems on their bombs with the goal of minimizing civilian casualties, although the damage can still be devastating, especially in urban areas." The United Nations and every major human rights group in the world have routinely condemned Israeli actions in Gaza, along with the Hamas barbarism on October 7, and accused the Israeli army of potentially committing war crimes. Human Rights Watch has rightly called for a suspension of all weapons transfers to Israel and Hamas.

This story originally appeared in New York Focus, a nonprofit news publication investigating power in New York. Vigilante violence is at an all-time high in the occupied West Bank. Emboldened by the war in the Gaza Strip and backed by the military, Israeli settlers aiming to annex more and more of the Palestinian territory have launched hundreds of attacks, displacing people from at least 17 communities over the past month while soldiers and settlers have killed nearly 200. And at least three New York nonprofit organizations are calling on donors to help outfit those settlers with combat gear, in a fundraising blitz funneling millions of tax-deductible dollars to the West Bank aggression. By chipping into a "thermal drone matching campaign," donors can help the Long Island–based One Israel Fund buy remote-controlled aerial vehicles for settler militias.

Bad news for those who struggle with anxiety, get too competitive, or simply choke under pressure: new research suggests that you may have to stay at home on Earth while other, more laid back and'agreeable' types colonize Mars. The new study, which is still undergoing peer review, ran computer simulations tracking the progress of human settlements on the Red Planet through their first 28 years of virtual operation. 'Agreeable personality types were assessed to be the most enduring for the long term,' the researchers found, across all four of the personality types used in their simulations, 'whereas neurotics showed least adaptation capacity.' The researchers also discovered that the minimum number of settlers needed to successfully operate a human colony on Mars was much lower than previously expected: just 22 people. 'Contrary to other literature,' they wrote of their simulated Martian colonies, 'the minimum number of people with all personality types that can lead to a sustainable settlement is in the tens and not hundreds.'

Israeli settlers rampage through Palestinian villages, Syria's president is getting friendly with several Arab states, and attacks against African migrants in Tunisia. Here's your round up of our coverage, written by Abubakr Al-Shamahi, Al Jazeera Digital's Middle East and North Africa editor. With the backing of the United States, Israeli and Palestinian officials met at a Jordanian resort on Sunday in an attempt to reach a deal to end more than a year of intense violence. By the end of it, the two sides said they had agreed to work closely together, to bring about a "de-escalation on the ground". And, according to a joint statement, Israel even said it would suspend the building of any new settlement units in the occupied West Bank.

Quite how Halo hasn't made it to the screen, small or big, before this is an enigma almost as nebulous as the long-running first person shooter video game's crowded mythos. Luminaries such as Steven Spielberg, Peter Jackson and District 9's Neill Blomkamp have all been involved in trying to get a film based on the explosive exploits of Masterchief across the line for the best part of two decades, yet to no avail. Even this big-budget – it reputedly cost more than $200m and looks like gold – TV series starring Pablo Schreiber as the genetically engineered soldier-hero of the United Nations Space Command (UNSC) has been held up for two years by Covid. Never mind, it's here now, and fans of the games who just want to see their nightly battles with giant space monsters played out on the TV screen will no doubt be more than content with Kyle Killen and Steven Kane's adventurous if somewhat insipid reimagining. Unfortunately, those of us who don't recognise every re-enacted power-up bleep and helmet-cam vision of destruction will probably find ourselves wondering, much of the time, quite what is going on.

The belief that AI dominance is imperative for economic development, military control, and strategic competitiveness has accelerated AI development initiatives across countries. The release of national strategic plans has been accompanied by billions of dollars in investment as well as concrete policies to attract relevant talent and technology. In our previous post "How different countries view artificial intelligence", we presented a snapshot of governments' planning for AI, based on our analysis of 34 national strategic AI plans. Our post covered the description of AI plans and categorized countries based on their coverage of various related concepts. In this post, we extend details about what accounts for the variation in countries' AI plans.

Last year, about a month into the pandemic, I reached for something comforting: the 1992 science-fiction novel "Red Mars," by Kim Stanley Robinson. I'd first read it as a teen-ager, and had reread it a handful of times by my early twenties. Along with its two sequels, "Green Mars" and "Blue Mars," the novel follows the first settlers to reach the red planet. They establish cities, break away from Earth's control, and transform the arid surface into a garden oasis, setting up a new society in the course of a couple hundred years. On the cover of my well-worn copy, Arthur C. Clarke declared it "the best novel on the colonization of Mars that has ever been written."