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🔗 Psychology 🔗 Sociology

The Ringelmann effect is the tendency for individual members of a group to become increasingly less productive as the size of their group increases. This effect, discovered by French agricultural engineer Maximilien Ringelmann (1861–1931), illustrates the inverse relationship that exists between the size of a group and the magnitude of group members’ individual contribution to the completion of a task. While studying the relationship between process loss (i.e., reductions in performance effectiveness or efficiency) and group productivity, Ringelmann (1913) found that having group members work together on a task (e.g., pulling a rope) actually results in significantly less effort than when individual members are acting alone. Ringelmann discovered that as more and more people are added to a group, the group often becomes increasingly inefficient, ultimately violating the notion that group effort and team participation reliably leads to increased effort on behalf of the members.

🔗 Computing 🔗 Computer science

In computer science, the five-minute rule is a rule of thumb for deciding whether a data item should be kept in memory, or stored on disk and read back into memory when required. It was first formulated by Jim Gray and Gianfranco Putzolu in 1985, and then subsequently revised in 1997 and 2007 to reflect changes in the relative cost and performance of memory and persistent storage.

The rule is as follows:

The 5-minute random rule: cache randomly accessed disk pages that are re-used every 5 minutes or less.

Gray also issued a counterpart one-minute rule for sequential access:

The 1-minute rule: cache sequentially accessed disk pages that are re-used every 1 minute or less.

Although the 5-minute rule was invented in the realm of databases, it has also been applied elsewhere, for example, in Network File System cache capacity planning.

The original 5-minute rule was derived from the following cost-benefit computation:

BreakEvenIntervalinSeconds = (PagesPerMBofRAM / AccessesPerSecondPerDisk) × (PricePerDiskDrive / PricePerMBofRAM)

Applying it to 2007 data yields approximately a 90-minutes interval for magnetic-disk-to-DRAM caching, 15 minutes for SSD-to-DRAM caching and 2​¹⁄₄ hours for disk-to-SSD caching. The disk-to-DRAM interval was thus a bit short of what Gray and Putzolu anticipated in 1987 as the "five-hour rule" was going to be in 2007 for RAM and disks.

According to calculations by NetApp engineer David Dale as reported in The Register, the figures for disc-to-DRAM caching in 2008 were as follows: "The 50KB page break-even was five minutes, the 4KB one was one hour and the 1KB one was five hours. There needed to be a 50-fold increase in page size to cache for break-even at five minutes." Regarding disk-to-SSD caching in 2010, the same source reported that "A 250KB page break even with SLC was five minutes, but five hours with a 4KB page size. It was five minutes with a 625KB page size with MLC flash and 13 hours with a 4KB MLC page size."

In 2000, Gray and Shenoy applied a similar calculation for web page caching and concluded that a browser should "cache web pages if there is any chance they will be re-referenced within their lifetime."

🔗 Chess

The mutilated chessboard problem is a tiling puzzle proposed by philosopher Max Black in his book Critical Thinking (1946). It was later discussed by Solomon W. Golomb (1954), Gamow & Stern (1958) and by Martin Gardner in his Scientific American column "Mathematical Games". The problem is as follows:

Suppose a standard 8×8 chessboard has two diagonally opposite corners removed, leaving 62 squares. Is it possible to place 31 dominoes of size 2×1 so as to cover all of these squares?

Most considerations of this problem in literature provide solutions "in the conceptual sense" without proofs. John McCarthy proposed it as a hard problem for automated proof systems. In fact, its solution using the resolution system of inference is exponentially hard.

🔗 Geography 🔗 New York (state) 🔗 New York (state)/Hudson Valley

Agloe is a fictional hamlet in Colchester, Delaware County, New York, that became an actual landmark after mapmakers made up the community as a phantom settlement, an example of a "copyright trap" and similar to a trap street. Agloe was put onto the map in order to catch plagiarism as it appears only on their map and not on any others. Soon, using fictional "copyright traps" became a typical strategy in mapmaker design to thwart plagiarism. Agloe was known as a "paper town" because of this.

🔗 Finance & Investment

Peer-to-peer insurance is a reciprocity insurance contract through the Collaborative consumption concept.

🔗 Aviation 🔗 Military history 🔗 Military history/Military aviation 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Aviation/Aviation accident 🔗 Aviation/aircraft 🔗 Military history/Cold War 🔗 Greenland

The Kee Bird was a United States Army Air Forces Boeing B-29 Superfortress, serial 45-21768, of the 46th Reconnaissance Squadron, that became marooned after making an emergency landing in northwest Greenland during a secret Cold War spying mission on 21 February 1947. While the entire crew was safely evacuated after spending three days in the isolated Arctic tundra, the aircraft itself was left at the landing site. It lay there undisturbed until 1994, when a privately funded mission was launched to repair and return it. During the attempted recovery, a fire broke out, resulting in the destruction and loss of the airframe on the ground.

🔗 Video games 🔗 Board and table games 🔗 Role-playing games

In game design, balance is the concept and the practice of tuning a game's rules, usually with the goal of preventing any of its component systems from being ineffective or otherwise undesirable when compared to their peers. An unbalanced system represents wasted development resources at the very least, and at worst can undermine the game's entire ruleset by making important roles or tasks impossible to perform.

🔗 Board and table games

Uckers is a two- or four-player board game traditionally played in the Royal Navy and has spread to many of the other arms of the UK Armed Forces as well as to, mainly Commonwealth Forces. It can now be found also in the Royal Marines, Army Air Corps, Royal Canadian Navy, Royal New Zealand Navy, Royal Australian Navy, Royal Australian Air Force (RAAF), Royal Dutch Navy, and the Royal Air Force (RAF). It is believed to originate in the 18th/19th centuries from the Indian game Pachisi, although the first reference to it in print does not appear until 1946. It is mentioned in a diary by EJF Records (served 1928-1950) in 1937 as Huckers. Uckers is generally played using the rules stated below, but these will vary from one branch of the Royal Navy to another, most famously with the WAFU Rules of the Fleet Air Arm. Where those branches of the RN have worked with the other Armed Forces usually has dictated what rules the new playing Service use; why fellow aviators tend to play under WAFU Rules for example.

It is also played in units of the Army Air Corps (United Kingdom) where it was introduced by aircraft technicians on loan from the Fleet Air Arm in the late 1950s/early 1960s. Uckers boards can now also be found in most RAF Squadron crewroom, where the game has caught on, especially with the Aircraft Technicians. Most RAAF crew rooms feature uckers boards also. In addition to the units services, units mentioned, uckers was also played by units in the Royal Artillery, particularly meteorologists and LifeFlight Toowoomba Rescue Helicopter crews aka Rescue 588. The current and now 7-time world champion is Queenslander Mark Arthur. In the UK the Pusser's Rum World 'Uckers championships have been played for the last 5 years at various ROYAL NAVAL MUSEUMS, the most being notable being 2017 when the final was played on Nelson's Flagship HMS VICTORY and was won by the'timber shifters' Wally Blagden and David Clark both ex RN. The next Pusser's Rum WORLD 'uckers' championships are being played in the Explosion Museum Gosport 26 October 2019. Wally andDavid are also current HMS GANGES Champions won in April 2019 Update Wally Blagden and Dave Clark the 'Timbershifters' have won the 2019 Championships. Knock knock. The chicken

It is similar to the board game Ludo and is based on the same principles; getting four player pieces around the board before the opposition. The whole point of Uckers is to get all player pieces home before the opponent does. However, greater glory is attached to achieving all pieces home without the opponent getting any home at all—this is known as an 8 piecer. The ultimate win is when the player gets all their pieces home and the opponent has all their pieces still in the base—this is called an 8 piece in harbour, or an eight-piece dicking and merits the unfortunate player's name to be recorded on the reverse of the board.

🔗 Lists 🔗 Songs 🔗 Albums

This list consists of albums or songs that have been considered the worst music ever made by various combinations of music critics, television broadcasters (such as MTV), radio stations, composers, and public polls.

Individual tastes can vary widely such that very little consensus can be achieved. For example, the winning song in a CNN email poll received less than 5 percent of the total votes cast.

🔗 Biography 🔗 Computing

Francesco Vianello (30 August 1952 – 3 May 2009), better known by his nickname Fravia (sometimes +Fravia or Fravia+), was a software reverse engineer, and hacker, known for his web archive of reverse engineering techniques and papers. He is also known for his work on steganography. He had taught on subjects such as data mining, anonymity, stalking, klebing, advertisement reversing and ad-busting.

Fravia spoke six languages (including Latin) and had a degree in the history of the early Middle Ages. He was an expert in linguistics-related informatics. For five years he made available a large quantity of material related to reverse engineering through his website, which also hosted the advice of reverse engineering experts, known as reversers, who provided tutorials and essays on how to hack software code as well as advice related to the assembly and disassembly of applications, and software protection reversing.

Fravia was a professor at the High Cracking University (+HCU), founded by Old Red Cracker (+ORC), a legendary figure in reverse engineering, to conduct research into Reverse Code Engineering. The addition of the "+" sign in front of the nickname of a reverser signified membership in the +HCU. His website was known as "+Fravia's Pages of Reverse Engineering" and he used it to challenge programmers as well as the wider society to "reverse engineer" the "brainwashing of a corrupt and rampant materialism". In its heyday, his website was receiving millions of visitors per year and its influence was "widespread".

His web presence dates from 1995 when he first got involved in research related to reverse code engineering (RCE). In 2000 he changed his focus and concentrated on advanced internet search methods and the reverse engineering of search engine code.

His websites "www.fravia.com" and "www.searchlores.org" contained a large amount of specialised information related to data mining. His website "www.searchlores.org" has been called a "very useful instrument for searching the web", and his "www.fravia.com" site has been described as "required reading for any spy wanting to go beyond simple Google searches."