Random Articles (Page 2)
Have a deep view into what people are curious about.
π Tupolev Tu-144
The Tupolev Tu-144 (Russian: TyΠΏΠΎΠ»Π΅Π² Π’Ρ-144; NATO reporting name: Charger) is a retired jet airliner and commercial supersonic transport aircraft (SST). It was the world's first commercial SST (maiden flight β 31 December 1968), the second being the Anglo-French Concorde (maiden flight β 2 March 1969). The design was a product of the Tupolev design bureau, headed by Alexei Tupolev, of the Soviet Union and manufactured by the Voronezh Aircraft Production Association in Voronezh, Russia. It conducted 102 commercial flights, of which only 55 carried passengers, at an average service altitude of 16,000 metres (52,000Β ft) and cruised at a speed of around 2,000 kilometres per hour (1,200Β mph) (Mach 1.6).
The prototype's first flight was made on 31 December 1968, near Moscow from Zhukovsky Airport, two months before the first flight of Concorde. The Tu-144 first went supersonic on 5 June 1969 (Concorde first went supersonic on 1 October 1969), and on 26 May 1970 became the world's first commercial transport to exceed Mach 2. The aircraft used a new construction technique which resulted in large unexpected cracks, which resulted in several crashes. A Tu-144 crashed in 1973 at the Paris Air Show, delaying its further development. The aircraft was introduced into commercial service on 26 December 1975. In May 1978, another Tu-144 (an improved version, the Tu-144D) crashed on a test flight while being delivered. The aircraft remained in use as a cargo aircraft until 1983, when the Tu-144 commercial fleet was grounded. The Tu-144 was later used by the Soviet space program to train pilots of the Buran spacecraft, and by NASA for supersonic research until 1999, when the Tu-144 made its last flight (26 June 1999).
Discussed on
- "Tupolev Tu-144" | 2013-10-20 | 39 Upvotes 18 Comments
π Bank of North Dakota
The Bank of North Dakota (BND) is a state-owned, state-run financial institution based in Bismarck, North Dakota. It is the only government-owned general-service bank in the United States. It is the legal depository for all state funds in North Dakota, and uses these deposits to fund development, agriculture, and small businesses.
The bank was established in the early 20th century to promote agriculture, commerce, and industry in the state. It has received praise and media attention in the wake of the financial crisis of 2007β2008. and for their actions during the COVID-19 pandemic.
According to available data, the bank has turned a profit every year since its founding. The BND has a favorable reputation among North Dakotans. Other states have tried to replicate the BND elsewhere, but have been limited by political gridlock and the power dynamics in banking.
Discussed on
- "Bank of North Dakota" | 2024-12-18 | 63 Upvotes 35 Comments
π Agglutinative Language
An agglutinative language is a type of synthetic language with morphology that primarily uses agglutination. Words may contain different morphemes to determine their meanings, but all of these morphemes (including stems and affixes) remain, in every aspect, unchanged after their unions. This results in generally more easily deducible word meanings if compared to fusional languages, which allow modifications in either or both the phonetics or spelling of one or more morphemes within a word. This usually results in a shortening of the word, or it provides easier pronunciation.
Agglutinative languages have generally one grammatical category per affix while fusional languages have multiple. The term was introduced by Wilhelm von Humboldt to classify languages from a morphological point of view. It is derived from the Latin verb agglutinare, which means "to glue together".
Non-agglutinative synthetic languages are fusional languages; morphologically, they combine affixes by "squeezing" them together, drastically changing them in the process, and joining several meanings in a single affix (for example, in the Spanish word comΓ "I ate", the suffix -Γ carries the meanings of first person, singular number, past tense, perfective aspect, indicative mood, active voice.) The term agglutinative is sometimes incorrectly used as a synonym for synthetic. Used in this way, the term embraces both fusional languages and inflected languages. The agglutinative and fusional languages are two ends of a continuum, with various languages falling more toward one or the other end. For example, Japanese is generally agglutinative, but displays fusion in otΕto (εΌ, younger brother), from oto+hito (originally woto+pito), and in its non-affixing verb conjugations. A synthetic language may use morphological agglutination combined with partial usage of fusional features, for example in its case system (e.g., German, Dutch, and Persian).
Agglutinative languages tend to have a high rate of affixes or morphemes per word, and to be very regular, in particular with very few irregular verbs. For example, Japanese has very few irregular verbs β only two are significantly irregular, and there are only about a dozen others with only minor irregularity; Ganda has only one (or two, depending on how "irregular" is defined); while in the Quechua languages, all the ordinary verbs are regular. Korean has only ten irregular forms of conjugation except for the passive and causative conjugations. Georgian is an exception; it is highly agglutinative (with up to eight morphemes per word), but it has a significant number of irregular verbs with varying degrees of irregularity.
Discussed on
- "Agglutinative Language" | 2019-11-19 | 59 Upvotes 29 Comments
π Non-blocking synchronization
In computer science, an algorithm is called non-blocking if failure or suspension of any thread cannot cause failure or suspension of another thread; for some operations, these algorithms provide a useful alternative to traditional blocking implementations. A non-blocking algorithm is lock-free if there is guaranteed system-wide progress, and wait-free if there is also guaranteed per-thread progress.
The word "non-blocking" was traditionally used to describe telecommunications networks that could route a connection through a set of relays "without having to re-arrange existing calls", see Clos network. Also, if the telephone exchange "is not defective, it can always make the connection", see nonblocking minimal spanning switch.
Discussed on
- "Non-blocking synchronization" | 2010-02-03 | 21 Upvotes 8 Comments
π Dagen H β the day Sweden switched to driving on the right
Dagen H (H day), today usually called "HΓΆgertrafikomlΓ€ggningen" ("The right-hand traffic diversion"), was the day on 3 September 1967, in which the traffic in Sweden switched from driving on the left-hand side of the road to the right. The "H" stands for "HΓΆgertrafik", the Swedish word for "right traffic". It was by far the largest logistical event in Sweden's history.
Discussed on
- "HΓΆgertrafikomlΓ€ggningen" | 2024-06-09 | 175 Upvotes 185 Comments
- "Dagen H β the day Sweden switched to driving on the right" | 2013-05-17 | 13 Upvotes 1 Comments
- "Dagen H: The day Sweden switched to the right hand side of the road" | 2010-07-19 | 50 Upvotes 19 Comments
π Culture-Bound Syndrome
In medicine and medical anthropology, a culture-bound syndrome, culture-specific syndrome, or folk illness is a combination of psychiatric and somatic symptoms that are considered to be a recognizable disease only within a specific society or culture. There are no objective biochemical or structural alterations of body organs or functions, and the disease is not recognized in other cultures. The term culture-bound syndrome was included in the fourth version of the Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 1994) which also includes a list of the most common culture-bound conditions (DSM-IV: Appendix I). Counterpart within the framework of ICD-10 (Chapter V) are the culture-specific disorders defined in Annex 2 of the Diagnostic criteria for research.
More broadly, an endemic that can be attributed to certain behavior patterns within a specific culture by suggestion may be referred to as a potential behavioral epidemic. As in the cases of drug use, or alcohol and smoking abuses, transmission can be determined by communal reinforcement and person-to-person interactions. On etiological grounds, it can be difficult to distinguish the causal contribution of culture upon disease from other environmental factors such as toxicity.
π ZMODEM
ZMODEM is a file transfer protocol developed by Chuck Forsberg in 1986, in a project funded by Telenet in order to improve file transfers on their X.25 network. In addition to dramatically improved performance compared to older protocols, ZMODEM also offered restartable transfers, auto-start by the sender, an expanded 32-bit CRC, and control character quoting supporting 8-bit clean transfers, allowing it to be used on networks that would not pass control characters.
In contrast to most transfer protocols developed for bulletin board systems (BBSs), ZMODEM was not directly based on, nor compatible with, the seminal XMODEM. Many variants of XMODEM had been developed in order to address one or more of its shortcomings, and most remained backward compatible and would successfully complete transfers with "classic" XMODEM implementations.
ZMODEM eschewed backward compatibility in favor of producing a radically improved protocol. It performed as well or better than any of the high-performance varieties of XMODEM, did so over links that previously didn't work at all, like X.25, or had poor performance, like Telebit modems, and included useful features found in few or no other protocols. ZMODEM became extremely popular on bulletin board systems (BBS) in the early 1990s, becoming a standard as widespread as XMODEM had been before it.
Discussed on
- "ZMODEM" | 2016-10-22 | 132 Upvotes 99 Comments
π K-anonymity
k-anonymity is a property possessed by certain anonymized data. The concept of k-anonymity was first introduced by Latanya Sweeney and Pierangela Samarati in a paper published in 1998 as an attempt to solve the problem: "Given person-specific field-structured data, produce a release of the data with scientific guarantees that the individuals who are the subjects of the data cannot be re-identified while the data remain practically useful." A release of data is said to have the k-anonymity property if the information for each person contained in the release cannot be distinguished from at least individuals whose information also appear in the release.
K-anonymity received widespread media coverage in 2018 when British computer scientist Junade Ali used the property alongside cryptographic hashing to create a communication protocol to anonymously verify if a password was leaked without disclosing the searched password. This protocol was implemented as a public API in Troy Hunt's Have I Been Pwned? service and is consumed by multiple services including password managers and browser extensions. This approach was later replicated by Google's Password Checkup feature.
Discussed on
- "K-Anonymity" | 2021-04-06 | 32 Upvotes 1 Comments
- "K-anonymity" | 2018-08-10 | 136 Upvotes 11 Comments
π Xsnow
Xsnow is a software application that was originally created as a virtual greeting card for Macintosh systems in 1984. In 1993, the concept was ported to the X Window System as Xsnow, and was included on a number of Linux distributions in the late 1990s.
Discussed on
- "Xsnow" | 2021-12-08 | 155 Upvotes 97 Comments
π Seed7 programming language
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.
Discussed on
- "Seed7 programming language" | 2015-11-11 | 21 Upvotes 3 Comments