Semantic URL

Semantic URLs, also sometimes referred to as clean URLs, RESTful URLs, user-friendly URLs, or search engine-friendly URLs, are Uniform Resource Locators (URLs) intended to improve the usability and accessibility of a website or web service by being immediately and intuitively meaningful to non-expert users. Such URL schemes tend to reflect the conceptual structure of a collection of information and decouple the user interface from a server's internal representation of information. Other reasons for using clean URLs include search engine optimization (SEO), conforming to the representational state transfer (REST) style of software architecture, and ensuring that individual web resources remain consistently at the same URL. This makes the World Wide Web a more stable and useful system, and allows more durable and reliable bookmarking of web resources.

Semantic URLs also do not contain implementation details of the underlying web application. This carries the benefit of reducing the difficulty of changing the implementation of the resource at a later date. For example, many non-semantic URLs include the filename of a server-side script, such as example.php, example.asp or cgi-bin. If the underlying implementation of a resource is changed, such URLs would need to change along with it. Likewise, when URLs are non-semantic, if the site database is moved or restructured it has the potential to cause broken links, both internally and from external sites, the latter of which can lead to removal from search engine listings. The use of semantic URLs presents a consistent location for resources to user-agents regardless of internal structure. A further potential benefit to the use of semantic URLs is that the concealment of internal server or application information can improve the security of a system.

Loading... please wait...

This page contains text from Wikipedia, the Free Encyclopedia - https://wn.com/Semantic_URL

Slug (projectile)

A slug is a term used for a solid ballistic projectile. It is "solid" in the sense of being composed of one piece; the shape can vary widely, including partially hollowed shapes. The term is occasionally applied to bullets (just the projectile, never the cartridge as a whole), but is most commonly applied to shotgun projectiles, to differentiate them from shotshells containing shot. Slugs are commonly fired from smoothbored barrels that are unable to impart the gyroscopic spin required for in-flight stability.

A water-slug refers to operating a submarine's torpedo tube that has been filled with water rather than a torpedo, thus shooting a "slug of water.".

Slug (disambiguation)

A slug is a gastropod mollusk without a shell or with a very small internal shell.

Slug or slugs may also refer to:

Objects

Slug (projectile), a solid ballistic projectile

Slug (coin), a counterfeit coin

Slug or blank, a piece of bar stock ready to be machined into a finished part

Slug (railroad), an accessory to a diesel-electric locomotive

Science and technology

Slug (mass), a unit of mass in the Imperial system

Grex (biology), an aggregation of amoebae

Slug, a nickname for the Linksys NSLU2

Slugs (autopilot system), an open-source autopilot system oriented toward inexpensive autonomous aircraft

Publishing

Slug (publishing), a short name given in newspaper editing to articles that are in production

Slug (typesetting), a piece of spacing material used in typesetting to space paragraphs

Slug (web publishing) a user- and SEO-friendly short text used in a URL to identify and describe

SLUG Magazine, Salt Lake Under Ground magazinea resource

Entertainment and sports

Music

Slug (rapper), an underground rapper best known as a member of the hip-hop group Atmosphere

This page contains text from Wikipedia, the Free Encyclopedia - https://wn.com/Slug_(disambiguation)

Collapsing manifold

In Riemannian geometry, a collapsing or collapsed manifold is an n-dimensional manifold M that admits a sequence of Riemannian metrics g_i, such that as i goes to infinity the manifold is close to a k-dimensional space, where k < n, in the Gromov–Hausdorff distance sense. Generally there are some restrictions on the sectional curvatures of (M, g_i). The simplest example is a flat manifold, whose metric can be rescaled by 1/i, so that the manifold is close to a point, but its curvature remains 0 for all i.

Examples

Generally speaking there are two types of collapsing:

(1) The first type is a collapse while keeping the curvature uniformly bounded, say $|\sec(M_i)|\le 1$ .

Let $M_i$ be a sequence of $n$ dimensional Riemannian manifolds, where $\sec(M_i)$ denotes the sectional curvature of the ith manifold. There is a theorem proved by Jeff Cheeger, Kenji Fukaya and Mikhail Gromov, which states that: There exists a constant $\varepsilon(n)$ such that if $|\sec(M_i)|\le 1$ and ${\rm Inj}(M_i)<\varepsilon(n)$ , then $M_i$ admits an N-structure, with ${\rm Inj}(M)$ denoting the injectivity radius of the manifold M. Roughly speaking the N-structure is a locally action of a nilmanifold, which is a generalization of an F-structure, introduced by Cheeger and Gromov. This theorem generalized previous theorems of Cheeger-Gromov and Fukaya where they only deal with the torus action and bounded diameter cases respectively.

This page contains text from Wikipedia, the Free Encyclopedia - https://wn.com/Collapsing_manifold

Collapse (medical)

Collapse is a sudden and often unannounced loss of postural tone (going weak), often but not necessarily accompanied by loss of consciousness.

If the episode was accompanied by a loss of consciousness, the term syncope is used. The main causes are cardiac (e.g. due to irregular heart beat, low blood pressure), seizures or a psychological cause. The main tool in distinguishing the causes is careful history on the events before, during and after the collapse, from the patient as well as from any possible witnesses. Other investigations may be performed to further strengthen the diagnosis, but many of these have a low yield.

References

1 2 Petkar S, Cooper P, Fitzpatrick AP (October 2006). "How to avoid a misdiagnosis in patients presenting with transient loss of consciousness". Postgrad Med J 82 (972): 630–41. doi:10.1136/pgmj.2006.046565. PMC 2653900. PMID 17068273.

This page contains text from Wikipedia, the Free Encyclopedia - https://wn.com/Collapse_(medical)

location on Google Map

Collapse of the World Trade Center

Coordinates: 40°42′41.12″N 74°00′44.00″W / 40.7114222°N 74.0122222°W / 40.7114222; -74.0122222

The Twin Towers of the World Trade Center collapsed on September 11, 2001, as a result of being struck by two jet airliners hijacked by 10 terrorists affiliated with al-Qaeda during the September 11 attacks. Two of the four hijacked airliners crashed into the Twin Towers, one into the North Tower (1 World Trade Center) and the other into the South Tower (2 World Trade Center). The collapse of the Twin Towers destroyed the rest of the complex, and debris from the collapsing towers severely damaged or destroyed more than a dozen other adjacent and nearby structures. The South Tower collapsed at 9:59 am, less than an hour after being hit by the second hijacked airliner, and at 10:28 am the North Tower collapsed. Later that day, 7 World Trade Center collapsed at 5:21 pm from fires that had started when the North Tower collapsed. As a result of the attacks to the towers, a total of 2,763 people died. Of the people who died in and within the vicinity of the towers, 2,192 were civilians, 343 were firefighters, and 71 law enforcement officers. Aboard the two airplanes, 147 civilians and 10 hijackers also died.