Deca

Deca or DECA may refer to:

See also

Deca-

Deca- or deka- (symbol da) is a decimal unit prefix in the metric system, denoting a factor of ten. The term is derived from the Greek deka (δέκα), meaning "ten".

The prefix was a part of the original metric system in 1795. It is not in very common usage, although the decapascal is occasionally used by audiologists. The decanewton is also encountered occasionally, probably because it is an SI approximation of the kilogram-force. Its use is more common in Central Europe. In German, Polish (deka, deko), Czech, Slovak and Hungarian, deca is common (and used a word on its own always means decagram). A runway number typically indicates its heading in decadegrees.

Before the symbol as an SI prefix was standardized as "da" with the introduction of the International System of Units in 1960, various other symbols were more common, such as "dk" (f.e. in the UK and Austria), "D" (f.e. in Germany), and "Da". For syntactical reasons, the HP 48, 49, 50 series as well as the HP 39gII and Prime calculators use the unit prefix "D".

Deca (journalism collective)

Deca is a cooperative of magazine writers co-owned and managed by its members. Their cooperative model is based on photo agencies like Magnum and NOOR. Each journalist reports and writes independently but stories are edited and promoted collectively. Their writers are based all over the world, including Rome, London, Shanghai, Barcelona, Beirut, Abu Dhabi, Los Angeles, New York, Seattle, and Washington, D.C. Collectively, they have reported from more than 90 countries and every continent but Antarctica. Deca's tagline is "The world, firsthand." They offer a subscription service to their stories as well as an iOS app, with an Android app in development. Readers can also purchase the stories for download as Kindle singles on Amazon.com.

History

Deca launched in June 2014 with the story "And The City Swallowed Them" by Mara Hvistendahl and a Kickstarter campaign that raised $32,627.

And The City Swallowed Them

"And The City Swallowed Them" is Deca's debut story, written by Mara Hvistendahl, published in June, 2014. It is a true crime nonfiction story about the murder of 22-year-old model Diana O'brien in Shanghai on July 6, 2008 based on dozens of interviews with investigators, models, and both the victim's and the convicted murderer's families. The short book touches on issues of urbanization, migration and underground economies, anchored by the narrative of the lives of the Diana O'Brien and her murderer. The Wall Street Journal, China Real Time blog wrote about the book: "And The City Swallowed Them looks at the world that brought two different kinds of newcomers together—foreigners, including young models fighting for emerging opportunities in high fashion, and China’s own migrants, including those traveling from poor villages who were willing to go to desperate measures to scrape together their own living.” Hvistendahl is the author of Unnatural Selection: Choosing Boys Over Girls, and the Consequences of a World Full of Men.

Analog (program)

Analog is a free web log analysis computer program that runs under Windows, Mac OS, Linux, and most Unix-like operating systems. It was first released on June 21, 1995, by Stephen Turner as generic freeware; the license was changed to the GNU General Public License in November 2004. The software can be downloaded for several computing platforms, or the source code can be downloaded and compiled if desired.

Analog has support for 35 languages, and provides the ability to do reverse DNS lookups on log files, to indicate where web site hits originate. It can analyze several different types of web server logs, including Apache, IIS, and iPlanet. It has over 200 configuration options and can generate 32 reports. It also supports log files for multiple virtual hosts.

The program is comparable to Webalizer or AWStats, though it does not use as many images, preferring to stick with simple bar charts and lists to communicate similar information. Analog can export reports in a number of formats including HTML, XHTML, XML, Latex and a delimited output mode (for example CSV) for importing into other programs. Delimited or "computer" output from Analog is often used to generate more structured and graphically rich reports using the third party Report Magic program.

Analog signal

An analog or analogue signal is any continuous signal for which the time varying feature (variable) of the signal is a representation of some other time varying quantity, i.e., analogous to another time varying signal. For example, in an analog audio signal, the instantaneous voltage of the signal varies continuously with the pressure of the sound waves. It differs from a digital signal, in which the continuous quantity is a representation of a sequence of discrete values which can only take on one of a finite number of values. The term analog signal usually refers to electrical signals; however, mechanical, pneumatic, hydraulic, human speech, and other systems may also convey or be considered analog signals.

An analog signal uses some property of the medium to convey the signal's information. For example, an aneroid barometer uses rotary position as the signal to convey pressure information. In an electrical signal, the voltage, current, or frequency of the signal may be varied to represent the information.

Structural analog

Structural analogs (structural analogue or simply analog) are models or representations that keep each other certain "structural similarity". It is used in engineering, chemistry, mathematics and other fields.

Despite the field diversity, all structural analog analysis use some level of abstraction to transform models in mathematical graphs, and detected structural analogies by algorithms. Example: for molecular structure comparison and classification operations, the compared compounds are modeled as a mathematical graph. Formally, when structures are represented by graphs, the concept of analog is related to a graph isomorphism.

Systems engineering

Analogical models are used in a method of representing a ‘target system’ by another, more understandable or analysable system.

Two systems have analog structures (see illustration) if they are isomorphic graphs and have equivalent (mapped) lumped elements. In Electronics, methods based on fault models of structural analogs gain some acceptance in industry.