Have a deep view into what people are curious about.

🔗 Poetry 🔗 Songs

"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.

🔗 Statistics

Extreme learning machines are feedforward neural networks for classification, regression, clustering, sparse approximation, compression and feature learning with a single layer or multiple layers of hidden nodes, where the parameters of hidden nodes (not just the weights connecting inputs to hidden nodes) need not be tuned. These hidden nodes can be randomly assigned and never updated (i.e. they are random projection but with nonlinear transforms), or can be inherited from their ancestors without being changed. In most cases, the output weights of hidden nodes are usually learned in a single step, which essentially amounts to learning a linear model. The name "extreme learning machine" (ELM) was given to such models by its main inventor Guang-Bin Huang.

According to their creators, these models are able to produce good generalization performance and learn thousands of times faster than networks trained using backpropagation. In literature, it also shows that these models can outperform support vector machines (SVM) and SVM provides suboptimal solutions in both classification and regression applications.

🔗 Architecture 🔗 National Register of Historic Places 🔗 Architecture/Historic houses

The White House Reconstruction, also known as the Truman Reconstruction, was a comprehensive dismantling and rebuilding of the interior of the White House from 1949 to 1952. A century and a half of wartime destruction and rebuilding, hurried renovations, additions of new services, technologies, the added third floor and inadequate foundations brought the Executive Residence portion of the White House Complex to near-imminent collapse.

In 1948, architectural and engineering investigations deemed it unsafe for occupancy. President Harry S. Truman, his family, and the entire residence staff were relocated across the street to Blair House. For over three years, the White House was gutted, expanded, and rebuilt.

🔗 Technology

A Tesla valve, called by Tesla a valvular conduit, is a fixed-geometry passive check valve. It allows a fluid to flow preferentially in one direction, without moving parts. The device is named after Nikola Tesla, who was awarded U.S. Patent 1,329,559 in 1920 for its invention. The patent application describes the invention as follows:

The interior of the conduit is provided with enlargements, recesses, projections, baffles, or buckets which, while offering virtually no resistance to the passage of the fluid in one direction, other than surface friction, constitute an almost impassable barrier to its flow in the opposite direction.

Tesla illustrates this with the drawing, showing one possible construction with a series of eleven flow-control segments, although any other number of such segments could be used as desired to increase or decrease the flow regulation effect.

One computational fluid dynamics simulation of Tesla valves with two and four segments showed that the flow resistance in the blocking (or reverse) direction was about 15 and 40 times greater, respectively, than the unimpeded (or forward) direction. This lends support to Tesla's patent assertion that in the valvular conduit in his diagram, a pressure ratio "approximating 200 can be obtained so that the device acts as a slightly leaking valve".

The Tesla valve is used in microfluidic applications and offers advantages such as scalability, durability, and ease of fabrication in a variety of materials.

🔗 Computing 🔗 Computing/Computer science

The Zero one infinity (ZOI) rule is a rule of thumb in software design proposed by early computing pioneer Willem van der Poel. It argues that arbitrary limits on the number of instances of a particular type of data or structure should not be allowed. Instead, an entity should either be forbidden entirely, only one should be allowed, or any number of them should be allowed. Although various factors outside that particular software could limit this number in practice, it should not be the software itself that puts a hard limit on the number of instances of the entity.

Examples of this rule may be found in the structure of many file systems' directories (also known as folders):

• 0 – The topmost directory has zero parent directories; that is, there is no directory that contains the topmost directory.
• 1 – Each subdirectory has exactly one parent directory (not including shortcuts to the directory's location; while such files may have similar icons to the icons of the destination directories, they are not directories at all).
• Infinity – Each directory, whether the topmost directory or any of its subdirectories, according to the file system's rules, may contain any number of files or subdirectories. Practical limits to this number are caused by other factors, such as space available on storage media and how well the computer's operating system is maintained.

In real-world software design, violations of this rule of thumb are common. For example, the FAT16 file system imposes a limit of 65,536 files to a directory.

🔗 Mathematics 🔗 Books

Proofs from THE BOOK is a book of mathematical proofs by Martin Aigner and Günter M. Ziegler. The book is dedicated to the mathematician Paul Erdős, who often referred to "The Book" in which God keeps the most elegant proof of each mathematical theorem. During a lecture in 1985, Erdős said, "You don't have to believe in God, but you should believe in The Book."

🔗 Food and drink 🔗 Turkey

Bulgur (from Arabic: برغل‎ bourghoul, "groats") is a cereal food made from the cracked parboiled groats of several different wheat species, most often from durum wheat. It originates in Middle Eastern cuisine.

🔗 Measurement

In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they are pure numbers with no associated units of measurement. Commonly used are parts-per-million (ppm, 10⁻⁶), parts-per-billion (ppb, 10⁻⁹), parts-per-trillion (ppt, 10⁻¹²) and parts-per-quadrillion (ppq, 10⁻¹⁵). This notation is not part of the International System of Units (SI) system and its meaning is ambiguous.

🔗 Human rights 🔗 Mass surveillance 🔗 Espionage 🔗 Technology 🔗 Lists 🔗 Politics

This is a list of government surveillance projects and related databases throughout the world.