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🔗 Computing 🔗 Computing/Software 🔗 Computing/Free and open-source software

BRL-CAD is a constructive solid geometry (CSG) solid modeling computer-aided design (CAD) system. It includes an interactive geometry editor, ray tracing support for graphics rendering and geometric analysis, computer network distributed framebuffer support, scripting, image-processing and signal-processing tools. The entire package is distributed in source code and binary form.

Although BRL-CAD can be used for a variety of engineering and graphics applications, the package's primary purpose continues to be the support of ballistic and electromagnetic analyses. In keeping with the Unix philosophy of developing independent tools to perform single, specific tasks and then linking the tools together in a package, BRL-CAD is basically a collection of libraries, tools, and utilities that work together to create, raytrace, and interrogate geometry and manipulate files and data. In contrast to many other 3D modelling applications, BRL-CAD primarily uses CSG rather than boundary representation. This means BRL-CAD can "study physical phenomena such as ballistic penetration and thermal, radiative, neutron, and other types of transport". It does also support boundary representation.

The BRL-CAD libraries are designed primarily for the geometric modeler who also wants to tinker with software and design custom tools. Each library is designed for a specific purpose: creating, editing, and ray tracing geometry, and image handling. The application side of BRL-CAD also offers a number of tools and utilities that are primarily concerned with geometric conversion, interrogation, image format conversion, and command-line-oriented image manipulation.

🔗 Philately 🔗 Netherlands

A postzegelcode is a hand-written method of franking in the Netherlands. It consists of a code containing nine numbers and letters that customers can purchase online from PostNL and write directly on their piece of mail within five days as proof-of-payment in place of a postage stamp.

For mail within the Netherlands the nine letters and numbers are written as a grid of 3x3. For international mail there is fourth additional row that contains P, N, L.

The system was started in 2013. Initially the postzegelcode was more expensive than a stamp because additional handling systems were required. Then for a while the postzegelcode was cheaper. Eventually the tariffs were set to the same price.

In December 2020, 590,000 people sent cards with postzegelcodes.

🔗 Amateur radio

Olivia MFSK is an amateur radioteletype protocol, using multiple frequency-shift keying (MFSK) and designed to work in difficult (low signal-to-noise ratio plus multipath propagation) conditions on shortwave bands. The signal can be accurately received even if the surrounding noise is 10 dB stronger. It is commonly used by amateur radio operators to reliably transmit ASCII characters over noisy channels using the high frequency (3–30 MHz) spectrum. The effective data rate of the Olivia MFSK protocol is 150 characters/minute.

Olivia modes are commonly referred to as Olivia X / Y (or, alternatively, Olivia Y / X ), where X refers to the number of different audio tones transmitted and Y refers to the bandwidth in hertz over which these signals are spread. Examples of common Olivia modes are 16/500, 32/1000 and 8/250.

🔗 Computing

Seed7 is an extensible general-purpose programming language designed by Thomas Mertes. It is syntactically similar to Pascal and Ada. Along with many other features, it provides an extension mechanism. Seed7 supports introducing new syntax elements and their semantics into the language, and allows new language constructs to be defined and written in Seed7. For example, programmers can introduce syntax and semantics of new statements and user defined operator symbols. The implementation of Seed7 differs significantly from that of languages with hard-coded syntax and semantics.

🔗 United States 🔗 Politics 🔗 Women's History 🔗 United States/U.S. presidential elections 🔗 United States/District of Columbia 🔗 Current events 🔗 Joe Biden 🔗 Women in Red

The inauguration of Joe Biden as the 46th President of the United States took place on January 20, 2021, before noon (EST), marking the commencement of the four-year term of Joe Biden as president and Kamala Harris as vice president. The inaugural ceremony took place on the West Front of the United States Capitol in Washington, D.C. and was the 59th presidential inauguration. Biden took the presidential oath of office, before which Harris took the vice presidential oath of office.

The inauguration took place amidst extraordinary political, public health, economic, and national security crises, including outgoing President Donald Trump's attempts to overturn the 2020 United States presidential election, which incited a storming of the Capitol, Trump's unprecedented second impeachment, and a threat of widespread civil unrest, which stimulated a nationwide law enforcement response. Festivities were sharply curtailed by efforts to prevent the spread of COVID-19 and mitigate the potential for violence near the Capitol. The live audience was limited to members of the 117th United States Congress and, for each, one guest of their choosing, resembling a State of the Union address. Public health measures such as mandatory face coverings, testing, temperature checks, and social distancing were used to protect participants in the ceremony.

"America United" and "Our Determined Democracy: Forging a More Perfect Union"—a reference to the Preamble to the United States Constitution—served as the inaugural themes.

🔗 Writing systems 🔗 Japan 🔗 Japan/History 🔗 Japan/Ainu

The Hokkaido characters (北海道異体文字, hokkaidō itai moji), also known as Aino characters (アイノモジ, aino moji) or Ainu characters (アイヌ文字, ainu moji), are a set of characters discovered around 1886 on the Japanese island of Hokkaido. At the time of their discovery, they were believed to be a genuine script, but this view is not generally supported today.

🔗 Olympics 🔗 Athletics

The men's marathon at the 1904 Summer Olympics in St. Louis, United States, took place on August 30 of that year, over a distance of 24.85 miles (40 km).

The race was run during the hottest part of the day on dusty country roads with minimal water supply; while thirty-two athletes representing four nations competed, only 14 managed to complete the race, which was a bizarre affair due to poor organization and officiating. While Fred Lorz was greeted as the apparent winner, he was later disqualified as he had hitched a ride in a car for part of the race. The actual winner, Thomas Hicks, was near collapse and hallucinating by the end of the race, a side effect of being administered brandy, raw eggs, and strychnine by his trainers. The fourth-place finisher, Andarín Carvajal, took a nap during the race after eating spoiled apples.

🔗 Philosophy 🔗 Philosophy/Logic 🔗 Philosophy/Philosophy of mind

Bonini's paradox, named after Stanford business professor Charles Bonini, explains the difficulty in constructing models or simulations that fully capture the workings of complex systems (such as the human brain).

🔗 Human rights 🔗 Military history 🔗 Death 🔗 Iran 🔗 Assyria 🔗 Military history/World War I 🔗 Iraq 🔗 Turkey 🔗 Former countries 🔗 Former countries/Ottoman Empire 🔗 Military history/Ottoman military history

The Sayfo or the Seyfo (lit. 'sword'; see below), also known as the Assyrian genocide, was the mass slaughter and deportation of Assyrian/Syriac Christians in southeastern Anatolia and Persia's Azerbaijan province by Ottoman forces and some Kurdish tribes during World War I.

The Assyrians were divided into mutually antagonistic churches, including the Syriac Orthodox Church, the Church of the East, and the Chaldean Catholic Church. Before World War I, they lived in mountainous and remote areas of the Ottoman Empire (some of which were effectively stateless). The empire's nineteenth-century centralization efforts led to increased violence and danger for the Assyrians.

Mass killing of Assyrian civilians began during the Ottoman occupation of Azerbaijan from January to May 1915, during which massacres were committed by Ottoman forces and pro-Ottoman Kurds. In Bitlis province, Ottoman troops returning from Persia joined local Kurdish tribes to massacre the local Christian population (including Assyrians). Ottoman forces and Kurds attacked the Assyrian tribes of Hakkari in mid-1915, driving them out by September despite the tribes mounting a coordinated military defense. Governor Mehmed Reshid initiated a genocide of all of the Christian communities in Diyarbekir province, including Syriac Christians, facing only sporadic armed resistance in some parts of Tur Abdin. Ottoman Assyrians living farther south, in present-day Iraq and Syria, were not targeted in the genocide.

The Sayfo occurred concurrently with and was closely related to the Armenian genocide, although the Sayfo is considered to have been less systematic. Local actors played a larger role than the Ottoman government, but the latter also ordered attacks on certain Assyrians. Motives for killing included a perceived lack of loyalty among some Assyrian communities to the Ottoman Empire and the desire to appropriate their land. At the 1919 Paris Peace Conference, the Assyro-Chaldean delegation said that its losses were 250,000 (about half the prewar population); the accuracy of this figure is unknown. They later revised their estimate to 275,000 dead at the Lausanne Conference in 1923. The Sayfo is less studied than the Armenian genocide. Efforts to have it recognized as a genocide began during the 1990s, spearheaded by the Assyrian diaspora. Although several countries acknowledge that Assyrians in the Ottoman Empire were victims of a genocide, this assertion is rejected by the Turkish government.

🔗 Biography 🔗 United Kingdom 🔗 Ships

The rescue of Roger Mallinson and Roger Chapman occurred between 29 August and 1 September 1973 after their Vickers Oceanics small submersible Pisces III was trapped on the seabed at a depth of 1,575 ft (480 m), 150 mi (240 km) off Ireland in the Celtic Sea. The 76-hour multinational rescue effort resulted in the deepest sub rescue in history.