Webtagr - Technology News Summarizer

Locating RFI Sources Using Near-Field Corrections: A Study for 21cm Cosmology During the Epoch of Reionization

2025-02-27

Researchers have developed a novel method to locate radio frequency interference (RFI) sources, particularly those from near-field objects like airplanes, using near-field corrections. This method combines far-field phasing, near-field corrections, and beamforming to precisely pinpoint the 3D location of RFI emitters by maximizing the coherence of curved near-field signals. This is more efficient than traditional flagging, preserving more usable data and enhancing the chances of detecting the 21cm signal during the Epoch of Reionization. Results demonstrate effective altitude estimation of RFI emitters, revealing performance differences under varying observational conditions, laying the groundwork for more precise RFI removal in the future.

(www.cambridge.org)

Tech Radio Frequency Interference 21cm Cosmology Epoch of Reionization

Correcting Bird's Proof of the Sieve of Eratosthenes: A Proof about Infinite Lists

2025-02-08

This paper corrects an erroneous proof by Richard Bird in his book *Thinking Functionally with Haskell* concerning the Sieve of Eratosthenes. Bird presents a circular, list-based implementation, but his proof hint is flawed. The authors provide a complete correctness proof by introducing new lemmas and appealing to a weakening of Bertrand's Postulate. The connection between this algorithm and David Turner's vision of "Total Functional Programming" is also explored.

(www.cambridge.org)

Development sieve of eratosthenes algorithm proof

Deconstructing Fenwick Trees with Functional Programming

2025-01-25

This paper delves into the implementation of Fenwick trees (also known as binary indexed trees). Starting with the more readily understandable segment tree, the author uses functional programming and equational reasoning to derive the implementation of Fenwick trees, revealing the logic behind their seemingly mysterious bitwise operations. By cleverly using a Haskell EDSL to operate on infinite two's complement binary numbers, the paper ultimately explains the secret of Fenwick trees' efficient implementation and proves the logarithmic time complexity of its update and range query operations.

(www.cambridge.org)

Development Fenwick tree segment tree

UK Adults with ADHD Experience 6-9 Year Life Expectancy Reduction

2025-01-24

A matched cohort study using UK primary care data reveals a significant life expectancy deficit for adults diagnosed with ADHD. Analyzing data from over 9.5 million individuals across 792 general practices between 2000 and 2019, researchers found a reduction of 6.78 years for men and 8.64 years for women compared to the general population. This shortened lifespan is likely attributed to modifiable risk factors and unmet support needs for both ADHD and co-occurring mental and physical health conditions. The findings highlight a critical unmet need for improved support and treatment for adults with ADHD.

(www.cambridge.org)

Tech Life Expectancy Mortality

Spectral Cavalcade: Early Iron Age Horse Sacrifice Unearthed in Southern Siberia

2025-01-15

Excavations at the late 9th-century BC Tunnug 1 tomb in Tuva, Southern Siberia, revealed the remains of at least 18 horses and one human, arranged in a manner reminiscent of the sacrificial ‘spectral riders’ described by Herodotus in 5th-century BC Scythian funerary rituals. The discovery of horse tack further links the find to early Mongolian horse cultures. Radiocarbon dating confirms the tomb's age, placing these rituals at the dawn of the Scythian period. This challenges previous understandings of Scythian origins and highlights early cultural exchange across the Eurasian steppe.

(www.cambridge.org)

Tech Scythian culture Horse sacrifice

Early Bronze Age Massacre Unearthed in Somerset, UK

2024-12-18

Excavations at Charterhouse Warren in Somerset, UK, have revealed a shocking Early Bronze Age massacre. At least 37 men, women, and children were brutally killed and butchered, their dismembered remains discarded in a 15-meter-deep natural shaft. Cut marks and blunt force trauma on the bones indicate a deliberate act of extreme violence, possibly including cannibalism. This discovery offers a unique insight into prehistoric violence in Britain, challenging previous understandings of social stability during this period and prompting further investigation into the motivations and social context of the event.

(www.cambridge.org)

Misc Early Bronze Age Massacre Cannibalism