In reinforcement learning, continuous time is often discretized by a time scale δ, to which the resulting performance is known to be highly sensitive. In this work, we seek tofind aδ-invariantalgorithm for policygradient (PG) methods, which performs well regardless of the value ofδ. We first identify the underlying reasons that cause PG methods to fail asδ 0, proving that the variance of the PG estimator can diverge to infinity in stochastic environments under a certain assumption of stochasticity. While durative actions or action repetition can be employed to haveδ-invariance, previous action repetition methods cannot immediately react to unexpected situations in stochastic environments. We thus propose a novelδ-invariant method namedSafe Action Repetition (SAR) applicable to any existing PG algorithm. SAR can handle the stochasticity of environments byadaptivelyreacting tochanges instates during action repetition.

Graphs are the most popular mathematical abstractions for relational data structures.

By exploiting smoothness of the expected losses, these bounds replace dependence onthemaximum gradient length bythevariance of the gradients, which was previously known only for linear losses. In addition, theyweakenthei.i.d.assumptionbyallowing,forexample,adversariallypoisoned rounds, which were previously considered in the expert and bandit setting.

Some AI-generated content is easy to spot as fake and is marked as such, but others are convincing enough that anyone scrolling through social media could easily be misled. Two leaders of a fledgling Japanese political party unveil a red logo reminiscent of Chinese Communist Party imagery. Grannies vent in public about what they see as political nonsense. Whatever the outcome of Sunday's Lower House election, the race will be remembered not least for having witnessed the full-blown debut of AI slop in Japanese politics. As more voters in Japan turn to social media for political updates and policy debates, the internet is increasingly looking like a dumping site for fake and dubious news and content. In a time of both misinformation and too much information, quality journalism is more crucial than ever.

What are Russia's gains from the Iran war? 'We are not losers; we are winners' Fierce fighting continues on the front line between Russian and Ukrainian forces despite the frigid winter temperatures, said Ukraine's Commander in Chief Oleksandr Syrskii, who stated the front line now stretches about 1,200km (750 miles) in length along eastern and southern parts of Ukraine. Increasing technological improvements in drone warfare on both sides of the conflict mean that the so-called "kill zone" - where troops are in greatest danger on the front line - is now up to 20km (12 miles) deep, Syrskii told reporters. Russia launched 328 drones and seven missiles at Ukraine overnight and into the early morning on Friday, Ukraine's air force said, claiming that air defences had shot down 297 drones. One person was killed and two others were injured in an overnight Russian attack using drones and powerful glide bombs on the central Dnipropetrovsk region, according to the head of the regional military administration, Oleksandr Hanzha. A Russian aerial attack on the southern Zaporizhia region during early daylight hours injured eight people and damaged 18 apartment blocks, according to regional military administration head Ivan Fedorov.

Joy Reid said the GOP is using Nicki Minaj to put "blackface on MAGA" during appearance on Don Lemon show, launching racially-charged criticism of the rapper's Trump alignment.

First introduced during the 1960, the invasive reptiles were'cold-stunned' during a record-breaking cold snap. Breakthroughs, discoveries, and DIY tips sent six days a week. To state the obvious, it's been a particularly frigid winter across most of the eastern United States. Winter's icy grip has not even spared the Sunshine State, where a total of 5,195 frozen green iguanas --an invasive species--have been removed from the ecosystem and euthanized. Green iguanas () are considered an invasive species in Florida.