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πŸ”— Tymnet

πŸ”— California πŸ”— Computing πŸ”— Computing/Networking

Tymnet was an international data communications network headquartered in Cupertino, California that used virtual call packet-switched technology and X.25, SNA/SDLC, BSC and Async interfaces to connect host computers (servers) at thousands of large companies, educational institutions, and government agencies. Users typically connected via dial-up connections or dedicated asynchronous connections.

The business consisted of a large public network that supported dial-up users and a private network that allowed government agencies and large companies (mostly banks and airlines) to build their own dedicated networks. The private networks were often connected via gateways to the public network to reach locations not on the private network. Tymnet was also connected to dozens of other public networks in the United States and internationally via X.25/X.75 gateways.

As the Internet grew and became almost universally accessible in the late 1990s, the need for services such as Tymnet migrated to the Internet style connections, but still had some value in the Third World and for specific legacy roles. However the value of these links continued to decrease, and Tymnet shut down in 2004.

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πŸ”— Type A and Type B personality theory

πŸ”— Medicine πŸ”— Psychology

Type A and Type B personality hypothesis describes two contrasting personality types. In this hypothesis, personalities that are more competitive, highly organized, ambitious, impatient, highly aware of time management and/or aggressive are labeled Type A, while more relaxed, less 'neurotic', 'frantic', 'explainable', personalities are labeled Type B.

The two cardiologists who developed this theory came to believe that Type A personalities had a greater chance of developing coronary heart disease. Following the results of further studies and considerable controversy about the role of the tobacco industry funding of early research in this area, some reject, either partially or completely, the link between Type A personality and coronary disease. Nevertheless, this research had a significant effect on the development of the health psychology field, in which psychologists look at how an individual's mental state affects physical health.

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πŸ”— List of Helicopter Prison Escapes

πŸ”— Aviation πŸ”— Crime πŸ”— Lists πŸ”— Novels πŸ”— Correction and Detention Facilities πŸ”— Popular Culture πŸ”— Novels/Crime

A helicopter prison escape is made when an inmate escapes from a prison by means of a helicopter. This list includes prisoner escapes where a helicopter was used in an attempt to free prisoners from a place of internment, a prison or correctional facility.

One of the earliest instances of using a helicopter to escape a prison was the escape of Joel David Kaplan, nicknamed "Man Fan", on August 19, 1971 from the Santa Martha Acatitla in Mexico. Kaplan was a New York businessman who not only escaped the prison but eventually got out of Mexico and went on to write a book about his experience, The 10-Second Jailbreak.

France has had more recorded helicopter escape attempts than any other country, with at least 11. One of the most notable French jail breaks occurred in 1986, when the wife of bank robber Michel Vaujour studied for months to learn how to fly a helicopter. Using her newly acquired skills, she rented a white helicopter and flew low over Paris to pluck her husband off the roof of his fortress prison. Vaujour was later seriously wounded in a shootout with police, and his pilot wife was arrested.

The record for most helicopter escapes goes to convicted murderer Pascal Payet, who has used helicopters to escape from prisons in 2001, 2003, and most recently 2007.

Another multiple helicopter escapee is Vasilis Paleokostas who on February 22, 2009 escaped for the second time from the same prison. Because of this, many prisons have taken applicable precautions, such as nets or cables strung over open prison courtyards.

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πŸ”— Coley's Toxins

πŸ”— Medicine πŸ”— Skepticism πŸ”— Alternative medicine

Coley's toxins (also called Coley's toxin, Coley's vaccine, Coley vaccine, Coley's fluid or mixed bacterial vaccine) is a mixture consisting of killed bacteria of species Streptococcus pyogenes and Serratia marcescens, named after William Coley, a surgical oncologist at the Hospital for Special Surgery who developed the mixture in the late 19th century as a treatment for cancer.

There is no evidence that Coley's toxins have any effectiveness in treating cancer, and use of them risks causing serious harm.

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πŸ”— The Price of Anarchy

πŸ”— Game theory

The Price of Anarchy (PoA) is a concept in economics and game theory that measures how the efficiency of a system degrades due to selfish behavior of its agents. It is a general notion that can be extended to diverse systems and notions of efficiency. For example, consider the system of transportation of a city and many agents trying to go from some initial location to a destination. Let efficiency in this case mean the average time for an agent to reach the destination. In the 'centralized' solution, a central authority can tell each agent which path to take in order to minimize the average travel time. In the 'decentralized' version, each agent chooses its own path. The Price of Anarchy measures the ratio between average travel time in the two cases.

Usually the system is modeled as a game and the efficiency is some function of the outcomes (e.g. maximum delay in a network, congestion in a transportation system, social welfare in an auction, ...). Different concepts of equilibrium can be used to model the selfish behavior of the agents, among which the most common is the Nash equilibrium. Different flavors of Nash equilibrium lead to variations of the notion of Price of Anarchy as Pure Price of Anarchy (for deterministic equilibria), Mixed Price of Anarchy (for randomized equilibria), and Bayes–Nash Price of Anarchy (for games with incomplete information). Solution concepts other than Nash equilibrium lead to variations such as the Price of Sinking.

The term Price of Anarchy was first used by Elias Koutsoupias and Christos Papadimitriou, but the idea of measuring inefficiency of equilibrium is older. The concept in its current form was designed to be the analogue of the 'approximation ratio' in an approximation algorithm or the 'competitive ratio' in an online algorithm. This is in the context of the current trend of analyzing games using algorithmic lenses (algorithmic game theory).

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πŸ”— Literature-Based Discovery

πŸ”— Science

Literature-based discovery is a form of knowledge extraction and automated hypothesis generation that uses papers and other academic publications (the "literature") to find new relationships between existing knowledge (the "discovery"). The technique was pioneered by Don R. Swanson in the 1980s and has since seen widespread use.

Literature-based discovery does not generate new knowledge through laboratory experiments, as is customary for empirical sciences. Instead it seeks to connect existing knowledge from empirical results by bringing to light relationships that are implicated and "neglected". It is marked by empiricism and rationalism in concert or consilience.

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πŸ”— Yuan Longping has died

πŸ”— Biography πŸ”— China πŸ”— Biography/science and academia

Yuan Longping (Chinese: θ’ιš†εΉ³; September 7, 1930 – May 22, 2021) was a Chinese agronomist, member of the Chinese Academy of Engineering, known for developing the first hybrid rice varieties in the 1970s.

Hybrid rice has since been grown in dozens of countries in Africa, America, and Asiaβ€”providing a robust food source in areas with a high risk of famine. For his contributions, Yuan is always called the "Father of Hybrid Rice" by the Chinese media. On May 22, 2021, Yuan Longping died of multiple organ failure at the age of 90.

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πŸ”— Mode 2

πŸ”— History of Science

A knowledge production mode is a term from the sociology of science which refers to the way (scientific) knowledge is produced. So far, three modes have been conceptualized. Mode 1 production of knowledge is knowledge production motivated by scientific knowledge alone (basic research) which is not primarily concerned by the applicability of its findings. Mode 1 is founded on a conceptualization of science as separated into discrete disciplines (e.g., a biologist does not bother about chemistry). Mode 2 was coined in 1994 in juxtaposition to Mode 1 by Michael Gibbons, Camille Limoges, Helga Nowotny, Simon Schwartzman, Peter Scott and Martin Trow. In Mode 2, multidisciplinary teams are brought together for short periods of time to work on specific problems in the real world for knowledge production (applied research) in the knowledge society. Mode 2 can be explained by the way research funds are distributed among scientists and how scientists focus on obtaining these funds in terms of five basic features: 1) knowledge produced in the context of application; (2) transdisciplinarity; (3) heterogeneity and organizational diversity; (4) social accountability and reflexivity; (5) and quality control. Subsequently, Carayannis and Campbell described a Mode 3 knowledge in 2006.

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πŸ”— Personal Knowledge Management

πŸ”— Computing

Personal knowledge management (PKM) is a process of collecting information that a person uses to gather, classify, store, search, retrieve and share knowledge in their daily activities (Grundspenkis 2007) and the way in which these processes support work activities (Wright 2005). It is a response to the idea that knowledge workers need to be responsible for their own growth and learning (Smedley 2009). It is a bottom-up approach to knowledge management (KM) (Pollard 2008).

πŸ”— Charlieplexing

πŸ”— Computing πŸ”— Electronics πŸ”— Electrical engineering

Charlieplexing (also known as tristate multiplexing, reduced pin-count LED multiplexing, complementary LED drive and crossplexing) is a technique for accessing a large number of LEDs, switches, micro-capacitors or other I/O entities, using very few tri-state logic wires from a microcontroller, these entities being wired as discrete components, x/y arrays, or woven in a diagonally intersecting pattern to form diagonal arrays.

The method uses the tri-state logic capabilities of microcontrollers in order to gain efficiency over traditional multiplexing, each I/O pin being capable, when required, of rapidly changing between the three states, logical 1, logical 0, and high impedance.

This enables these I/O entities (LEDs, switches etc.) to be connected between any two microcontroller I/Os - e.g. with 4 I/Os, each I/O can pair with 3 other I/Os, resulting in 6 unique pairings (1/2, 1/3, 1/4, 2/3, 2/4, 3/4). Only 4 pairings are possible with standard x/y multiplexing (1/3, 1/4, 2/3, 2/4). Also, due to the microcontroller's ability to reverse the polarity of the 6 I/O pairs, the number of LEDS (or diodes) that are uniquely addressable, can be doubled to 12 - adding LEDS 2/1, 3/1, 4/1, 3/2, 4/2 and 4/3.

Although it is more efficient in its use of I/O, a small amount of address manipulation is required when trying to fit Charlieplexing into a standard x/y array.

Other issues that affect standard multiplexing but are exacerbated by Charlieplexing are:

  • consideration of current requirements and the forward voltages of the LEDs.
  • a requirement to cycle through the in-use LEDs rapidly so that the persistence of the human eye perceives the display to be lit as a whole. Multiplexing can generally be seen by a strobing effect and skewing if the eye's focal point is moved past the display rapidly.


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