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🔗 Rongorongo
Rongorongo (; Rapa Nui: [ˈɾoŋoˈɾoŋo]) is a system of glyphs discovered in the 19th century on Easter Island that appears to be writing or proto-writing. Numerous attempts at decipherment have been made, none successfully. Although some calendrical and what might prove to be genealogical information has been identified, none of these glyphs can actually be read. If rongorongo does prove to be writing and proves to be an independent invention, it would be one of very few independent inventions of writing in human history.
Two dozen wooden objects bearing rongorongo inscriptions, some heavily weathered, burned, or otherwise damaged, were collected in the late 19th century and are now scattered in museums and private collections. None remain on Easter Island. The objects are mostly tablets shaped from irregular pieces of wood, sometimes driftwood, but include a chieftain's staff, a bird-man statuette, and two reimiro ornaments. There are also a few petroglyphs which may include short rongorongo inscriptions. Oral history suggests that only a small elite was ever literate and that the tablets were sacred.
Authentic rongorongo texts are written in alternating directions, a system called reverse boustrophedon. In a third of the tablets, the lines of text are inscribed in shallow fluting carved into the wood. The glyphs themselves are outlines of human, animal, plant, artifact and geometric forms. Many of the human and animal figures, such as glyphs 200 and 280 , have characteristic protuberances on each side of the head, possibly representing eyes.
Individual texts are conventionally known by a single uppercase letter and a name, such as Tablet C, the Mamari Tablet. The somewhat variable names may be descriptive or indicate where the object is kept, as in the Oar, the Snuffbox, the Small Santiago Tablet, and the Santiago Staff.
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- "Rongorongo" | 2020-02-08 | 80 Upvotes 17 Comments
🔗 BitTorrent's DHT
Mainline DHT is the name given to the Kademlia-based Distributed Hash Table (DHT) used by BitTorrent clients to find peers via the BitTorrent protocol. The idea of utilizing a DHT for distributed tracking was first implemented in Azureus 2.3.0.0 (now known as Vuze) in May 2005, from which it gained significant popularity. Unrelated but similarly timed BitTorrent, Inc. released their own similar DHT into their client, called Mainline DHT and thus popularized the use of distributed tracking in the BitTorrent Protocol. Measurement shows by 2013 users of Mainline DHT is from 10 million to 25 million, with a daily churn of at least 10 million.
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- "BitTorrent's DHT" | 2015-10-29 | 97 Upvotes 33 Comments
🔗 Non-compete clause
In contract law, a non-compete clause (often NCC), or covenant not to compete (CNC), is a clause under which one party (usually an employee) agrees not to enter into or start a similar profession or trade in competition against another party (usually the employer). Some courts refer to these as "restrictive covenants". As a contract provision, a CNC is bound by traditional contract requirements including the consideration doctrine.
The use of such clauses is premised on the possibility that upon their termination or resignation, an employee might begin working for a competitor or start a business, and gain competitive advantage by exploiting confidential information about their former employer's operations or trade secrets, or sensitive information such as customer/client lists, business practices, upcoming products, and marketing plans.
However, an over-broad CNC may prevent an employee from working elsewhere at all. English common law originally held any such constraint to be unenforceable under the public policy doctrine. Contemporary case law permits exceptions, but generally will only enforce CNCs to the extent necessary to protect the employer. Most jurisdictions in which such contracts have been examined by the courts have deemed CNCs to be legally binding so long as the clause contains reasonable limitations as to the geographical area and time period in which an employee of a company may not compete.
The extent to which non-compete clauses are legally allowed varies per jurisdiction. For example, the state of California in the United States invalidates non-compete-clauses for all but equity stakeholders in the sale of business interests.
Discussed on
- "Non-compete clause" | 2019-06-27 | 32 Upvotes 6 Comments
🔗 MU puzzle
The MU puzzle is a puzzle stated by Douglas Hofstadter and found in Gödel, Escher, Bach involving a simple formal system called "MIU". Hofstadter's motivation is to contrast reasoning within a formal system (ie., deriving theorems) against reasoning about the formal system itself. MIU is an example of a Post canonical system and can be reformulated as a string rewriting system.
Discussed on
- "MU puzzle" | 2018-12-15 | 83 Upvotes 45 Comments
🔗 Cyclorotor
A cyclorotor, cycloidal rotor, cycloidal propeller or cyclogiro, is a fluid propulsion device that converts shaft power into the acceleration of a fluid using a rotating axis perpendicular to the direction of fluid motion. It uses several blades with a spanwise axis parallel to the axis of rotation and perpendicular to the direction of fluid motion. These blades are cyclically pitched twice per revolution to produce force (thrust or lift) in any direction normal to the axis of rotation. Cyclorotors are used for propulsion, lift, and control on air and water vehicles. An aircraft using cyclorotors as the primary source of lift, propulsion, and control is known as a cyclogyro or cyclocopter. A unique aspect is that it can change the magnitude and direction of thrust without the need of tilting any aircraft structures. The patented application, used on ships with particular actuation mechanisms both mechanical or hydraulic, is named after German company Voith Turbo.
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- "Cyclorotor" | 2023-07-02 | 26 Upvotes 1 Comments
🔗 .test
.test is a reserved top-level domain intended for usage in software testing. It is guaranteed to never be registered into the Internet.
Along with .test, there are 11 other reserved test domains: .测试, .परीक्षा, .испытание, .테스트, .טעסט, .測試, .آزمایشی, .பரிட்சை, .δοκιμή, .إختبار, and .テスト.
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- ".test" | 2024-04-27 | 40 Upvotes 4 Comments
🔗 Cold Boot Attack
In computer security, a cold boot attack (or to a lesser extent, a platform reset attack) is a type of side channel attack in which an attacker with physical access to a computer performs a memory dump of a computer's random access memory by performing a hard reset of the target machine. Typically, cold boot attacks are used to retrieve encryption keys from a running operating system for malicious or criminal investigative reasons. The attack relies on the data remanence property of DRAM and SRAM to retrieve memory contents that remain readable in the seconds to minutes after power has been removed.
An attacker with physical access to a running computer typically executes a cold boot attack by cold-booting the machine and booting a lightweight operating system from a removable disk to dump the contents of pre-boot physical memory to a file. An attacker is then free to analyze the data dumped from memory to find sensitive data, such as the keys, using various forms of key finding attacks. Since cold boot attacks target random access memory, full disk encryption schemes, even with a trusted platform module installed are ineffective against this kind of attack. This is because the problem is fundamentally a hardware (insecure memory) and not a software issue. However, malicious access can be prevented by limiting physical access and using modern techniques to avoid storing sensitive data in random access memory.
Discussed on
- "Cold Boot Attack" | 2013-09-27 | 33 Upvotes 9 Comments
🔗 Circular Reporting
Circular reporting, or false confirmation, is a situation in source criticism where a piece of information appears to come from multiple independent sources, but in reality comes from only one source. In many cases, the problem happens mistakenly through sloppy reporting or intelligence-gathering. However, the situation can also be intentionally contrived by the source or reporter as a way of reinforcing the widespread belief in its information.
This problem occurs in a variety of fields, including intelligence gathering, journalism, and scholarly research. It is of particular concern in military intelligence because the original source has a higher likelihood of wanting to pass on misinformation, and because the chain of reporting is more prone to being obscured. It is also a problem in journalism and the development of conspiracy theories, in which the primary goal of a source spreading unlikely or hard-to-believe information is to make it appear to be widely known.
The case of the 2002 Niger uranium forgeries was a classic instance of circular reporting by intelligence agencies.
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- "Circular Reporting" | 2022-10-25 | 10 Upvotes 3 Comments
🔗 Desiderata
"Desiderata" (Latin: "things desired") is an early 1920s prose poem by the American writer Max Ehrmann. Although he copyrighted it in 1927, he distributed copies of it without a required copyright notice during 1933 and c. 1942, thereby forfeiting his US copyright. Largely unknown in the author's lifetime, its use in devotional and spoken word recordings in 1960 and 1971 called it to the attention of the world.
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- "Desiderata by Max Ehrmann" | 2022-08-19 | 60 Upvotes 36 Comments
- "Desiderata" | 2013-02-06 | 148 Upvotes 39 Comments
🔗 Eastgate Centre, Harare
The Eastgate Centre is a shopping centre and office block in central Harare, Zimbabwe whose architect is Mick Pearce. Designed to be ventilated and cooled by entirely natural means, it was probably the first building in the world to use natural cooling to this level of sophistication. It opened in 1996 on Robert Mugabe Avenue and Second Street, and provides 5,600 m² of retail space, 26,000 m² of office space and parking for 450 cars.
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- "Eastgate Centre, Harare" | 2019-07-13 | 201 Upvotes 61 Comments