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🔗 Korea 🔗 Buddhism

Wang ocheonchukguk jeon (Korean pronunciation: [waːŋotɕʰʌntɕʰukk͈uktɕ͈ʌn]; pinyin: wǎng wǔ tiānzhú guó zhuàn; "An account of travel to the five Indian kingdoms") is a travelogue by Buddhist monk Hyecho, who traveled from Korea to India, in the years 723 - 727/728 CE.

🔗 Electronics

The two capacitor paradox or capacitor paradox is a paradox, or counterintuitive thought experiment, in electric circuit theory. The thought experiment is usually described as follows: Two identical capacitors are connected in parallel with an open switch between them. One of the capacitors is charged with a voltage of ${\displaystyle V_{i}}$, the other is uncharged. When the switch is closed, some of the charge ${\displaystyle Q=CV_{i}}$ on the first capacitor flows into the second, reducing the voltage on the first and increasing the voltage on the second. When a steady state is reached and the current goes to zero, the voltage on the two capacitors must be equal since they are connected together. Since they both have the same capacitance ${\displaystyle C}$ the charge will be divided equally between the capacitors so each capacitor will have a charge of ${\displaystyle {Q \over 2}}$ and a voltage of ${\displaystyle V_{f}={Q \over 2C}={V_{i} \over 2}}$. At the beginning of the experiment the total initial energy ${\displaystyle W_{i}}$ in the circuit is the energy stored in the charged capacitor:

${\displaystyle W_{i}={1 \over 2}CV_{i}^{2}}$.

At the end of the experiment the final energy ${\displaystyle W_{f}}$ is equal to the sum of the energy in the two capacitors

${\displaystyle W_{f}={1 \over 2}CV_{f}^{2}+{1 \over 2}CV_{f}^{2}=CV_{f}^{2}=C({V_{i} \over 2})^{2}={1 \over 4}CV_{i}^{2}={1 \over 2}W_{i}}$

Thus the final energy ${\displaystyle W_{f}}$ is equal to half of the initial energy ${\displaystyle W_{i}}$. Where did the other half of the initial energy go?

🔗 Energy 🔗 Engineering

A heat pipe is a heat-transfer device that employs phase transition to transfer heat between two solid interfaces.

At the hot interface of a heat pipe, a volatile liquid in contact with a thermally conductive solid surface turns into a vapor by absorbing heat from that surface. The vapor then travels along the heat pipe to the cold interface and condenses back into a liquid, releasing the latent heat. The liquid then returns to the hot interface through capillary action, centrifugal force, or gravity and the cycle repeats.

Due to the very high heat transfer coefficients for boiling and condensation, heat pipes are highly effective thermal conductors. The effective thermal conductivity varies with heat pipe length and can approach 100 kW/(m⋅K) for long heat pipes, in comparison with approximately 0.4 kW/(m⋅K) for copper.

Modern CPU heat pipes are typically made of copper and use water as the working fluid. They are common in many consumer electronics like desktops, laptops, tablets, and high-end smartphones.

🔗 Computing 🔗 Computer science 🔗 Mathematics 🔗 Computing/Software 🔗 Computing/Computer science

In programming language theory and proof theory, the Curry–Howard correspondence (also known as the Curry–Howard isomorphism or equivalence, or the proofs-as-programs and propositions- or formulae-as-types interpretation) is the direct relationship between computer programs and mathematical proofs.

It is a generalization of a syntactic analogy between systems of formal logic and computational calculi that was first discovered by the American mathematician Haskell Curry and logician William Alvin Howard. It is the link between logic and computation that is usually attributed to Curry and Howard, although the idea is related to the operational interpretation of intuitionistic logic given in various formulations by L. E. J. Brouwer, Arend Heyting and Andrey Kolmogorov (see Brouwer–Heyting–Kolmogorov interpretation) and Stephen Kleene (see Realizability). The relationship has been extended to include category theory as the three-way Curry–Howard–Lambek correspondence.

🔗 United States 🔗 Human rights 🔗 History 🔗 Politics 🔗 Politics/American politics 🔗 African diaspora 🔗 United States History 🔗 United States/FBI 🔗 Civil Rights Movement 🔗 United States/U.S. history

COINTELPRO (syllabic abbreviation derived from COunter INTELligence PROgram) (1956–1971) was a series of covert and, at times, illegal projects conducted by the United States Federal Bureau of Investigation (FBI) aimed at surveilling, infiltrating, discrediting, and disrupting American political organizations. FBI records show that COINTELPRO resources targeted groups and individuals that the FBI deemed subversive, including feminist organizations, the Communist Party USA, anti–Vietnam War organizers, activists of the civil rights movement or Black Power movement (e.g. Martin Luther King Jr., the Nation of Islam, and the Black Panther Party), environmentalist and animal rights organizations, the American Indian Movement (AIM), independence movements (such as Puerto Rican independence groups like the Young Lords), and a variety of organizations that were part of the broader New Left. The program also targeted the Ku Klux Klan in 1964.

In another instance in San Diego, the FBI financed, armed, and controlled an extreme right-wing group of former members of the Minutemen anti-communist para-military organization, transforming it into a group called the Secret Army Organization that targeted groups, activists, and leaders involved in the Anti-War Movement, using both intimidation and violent acts.

The FBI has used covert operations against domestic political groups since its inception; however, covert operations under the official COINTELPRO label took place between 1956 and 1971. COINTELPRO tactics are still used to this day and have been alleged to include discrediting targets through psychological warfare; smearing individuals and groups using forged documents and by planting false reports in the media; harassment; wrongful imprisonment; and illegal violence, including assassination. The FBI's stated motivation was "protecting national security, preventing violence, and maintaining the existing social and political order".

Beginning in 1969, leaders of the Black Panther Party were targeted by the COINTELPRO and "neutralized" by being assassinated, imprisoned, publicly humiliated or falsely charged with crimes. Some of the Black Panthers affected included Fred Hampton, Mark Clark, Zayd Shakur, Geronimo Pratt, Mumia Abu-Jamal, and Marshall Conway. Common tactics used by COINTELPRO were perjury, witness harassment, witness intimidation, and withholding of evidence.

FBI Director J. Edgar Hoover issued directives governing COINTELPRO, ordering FBI agents to "expose, disrupt, misdirect, discredit, or otherwise neutralize" the activities of these movements and especially their leaders. Under Hoover, the agent in charge of COINTELPRO was William C. Sullivan. Attorney General Robert F. Kennedy personally authorized some of the programs. Although Kennedy only gave written approval for limited wiretapping of Martin Luther King's phones "on a trial basis, for a month or so", Hoover extended the clearance so his men were "unshackled" to look for evidence in any areas of King's life they deemed worthy.

🔗 Mathematics 🔗 Statistics

Anscombe's quartet comprises four data sets that have nearly identical simple descriptive statistics, yet have very different distributions and appear very different when graphed. Each dataset consists of eleven (x,y) points. They were constructed in 1973 by the statistician Francis Anscombe to demonstrate both the importance of graphing data when analyzing it, and the effect of outliers and other influential observations on statistical properties. He described the article as being intended to counter the impression among statisticians that "numerical calculations are exact, but graphs are rough."

🔗 Solar System/Mars 🔗 Solar System

The Mars monolith is a rectangular object (possibly a boulder) discovered on the surface of Mars. It is located near the bottom of a cliff, from which it likely fell. The Mars Reconnaissance Orbiter took pictures of it from orbit, roughly 180 miles (300 km) away.

Around the same time, the Phobos monolith made international news.

🔗 California 🔗 California/San Francisco Bay Area 🔗 Computing 🔗 Computing/Computer hardware

The traitorous eight was a group of eight employees who left Shockley Semiconductor Laboratory in 1957 to found Fairchild Semiconductor. William Shockley had in 1956 recruited a group of young PhD graduates with the goal to develop and produce new semiconductor devices. While Shockley had received a Nobel Prize in Physics and was an experienced researcher and teacher, his management of the group was authoritarian and unpopular. This was accentuated by Shockley's research focus not proving fruitful. After the demand for Shockley to be replaced was rebuffed, the eight left to form their own company.

Shockley described their leaving as a "betrayal". The eight who left Shockley Semiconductor were Julius Blank, Victor Grinich, Jean Hoerni, Eugene Kleiner, Jay Last, Gordon Moore, Robert Noyce, and Sheldon Roberts. In August 1957, they reached an agreement with Sherman Fairchild, and on September 18, 1957, they formed Fairchild Semiconductor. The newly founded Fairchild Semiconductor soon grew into a leader of the semiconductor industry. In 1960, it became an incubator of Silicon Valley and was directly or indirectly involved in the creation of dozens of corporations, including Intel and AMD. These many spin-off companies came to be known as "Fairchildren".

🔗 Religion 🔗 Visual arts 🔗 Buddhism 🔗 Asia

The Greco-Buddhist art or Gandhara art is the artistic manifestation of Greco-Buddhism, a cultural syncretism between Ancient Greek art and Buddhism. It had mainly evolved in the ancient region of Gandhara, located in the northwestern fringe of the Indian subcontinent.

The series of interactions leading to Gandhara art occurred over time, beginning with Alexander the Great's brief incursion into the area, followed by the Mauryan Emperor Ashoka converting the region to Buddhism. Buddhism became the prominent religion in the Indo-Greek Kingdoms. However, Greco-Buddhist art truly flowered and spread under the Kushan Empire, when the first surviving devotional images of the Buddha were created during the 1st-3rd centuries CE. Gandhara art reached its zenith from the 3rd-5th century CE, when most surviving motifs and artworks were produced.

Gandhara art is characterized by Buddhist subject matter, sometimes adapting Greco-Roman elements, rendered in a style and forms that are heavily influenced by Greco-Roman art. It has the strong idealistic realism and sensuous description of Hellenistic art, and it is believed to have produced the first representations of Gautama Buddha in human form, ending the early period of aniconism in Buddhism.

The representation of the human form in large sculpture had a considerable influence, both to the south in the rest of India, and to the east, where the spread of Buddhism carried its influence as far as Japan.

🔗 Computing

Reservoir computing is a framework for computation that may be viewed as an extension of neural networks. Typically an input signal is fed into a fixed (random) dynamical system called a reservoir and the dynamics of the reservoir map the input to a higher dimension. Then a simple readout mechanism is trained to read the state of the reservoir and map it to the desired output. The main benefit is that training is performed only at the readout stage and the reservoir is fixed. Liquid-state machines and echo state networks are two major types of reservoir computing. One important feature of this system is that it can use the computational power of naturally available systems which is different from the neural networks and it reduces the computational cost.