A computer is a program machine that receives input, stores and manipulates data, and provides output in a useful format.
Computer may also refer to:
The term "computer", in use from the early 17th century (the first known written reference dates from 1613), meant "one who computes": a person performing mathematical calculations, before electronic computers became commercially available. "The human computer is supposed to be following fixed rules; he has no authority to deviate from them in any detail." (Turing, 1950) Teams of people were frequently used to undertake long and often tedious calculations; the work was divided so that this could be done in parallel.
The first time the term "Computer" appeared in The New York Times was February 3, 1853; an obituary stated:
Since the end of the 20th century, the term "human computer" has also been applied to individuals with prodigious powers of mental arithmetic, also known as mental calculators.
The approach was taken for astronomical and other complex calculations. Perhaps the first example of organized human computing was by the Frenchman Alexis Claude Clairaut (1713–1765), when he divided the computation to determine timing of the return of Halley's Comet with two colleagues, Joseph Lalande and Nicole-Reine Lepaute.
Computer is an IEEE Computer Society practitioner-oriented magazine issued to all members of the society. It contains peer-reviewed articles, regular columns and interviews on current computing-related issues. The magazine can be categorized somewhere between a trade magazine and a research journal, drawing on elements of both. Computer provides information regarding current research developments, trends, best practices, and changes in the computing profession. Subscriptions of the magazine are provided free of cost to IEEE Computer Society members.
Computer covers all aspects of computer science. Since 2009, it has a digital edition too. The current editor is Sumi Helal of the University of Florida. Impact factor for 2013 was 1.438/
A chemical bond is a lasting attraction between atoms that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between atoms with opposite charges, or through the sharing of electrons as in the covalent bonds. The strength of chemical bonds varies considerably; there are "strong bonds" such as covalent or ionic bonds and "weak bonds" such as Dipole-dipole interaction, the London dispersion force and hydrogen bonding.
Since opposite charges attract via a simple electromagnetic force, the negatively charged electrons that are orbiting the nucleus and the positively charged protons in the nucleus attract each other. An electron positioned between two nuclei will be attracted to both of them, and the nuclei will be attracted toward electrons in this position. This attraction constitutes the chemical bond. Due to the matter wave nature of electrons and their smaller mass, they must occupy a much larger amount of volume compared with the nuclei, and this volume occupied by the electrons keeps the atomic nuclei relatively far apart, as compared with the size of the nuclei themselves. This phenomenon limits the distance between nuclei and atoms in a bond.
Bond (first name and dates unknown) was an English first-class cricketer associated with Marylebone Cricket Club (MCC) who was active in the 1800s. He is recorded in one match, totalling 8 runs with a highest score of 8 not out.
In finance, a bond is an instrument of indebtedness of the bond issuer to the holders. It is a debt security, under which the issuer owes the holders a debt and, depending on the terms of the bond, is obliged to pay them interest (the coupon) and/or to repay the principal at a later date, termed the maturity date. Interest is usually payable at fixed intervals (semiannual, annual, sometimes monthly). Very often the bond is negotiable, i.e. the ownership of the instrument can be transferred in the secondary market. This means that once the transfer agents at the bank medallion stamp the bond, it is highly liquid on the second market.
Thus a bond is a form of loan or IOU: the holder of the bond is the lender (creditor), the issuer of the bond is the borrower (debtor), and the coupon is the interest. Bonds provide the borrower with external funds to finance long-term investments, or, in the case of government bonds, to finance current expenditure. Certificates of deposit (CDs) or short term commercial paper are considered to be money market instruments and not bonds: the main difference is in the length of the term of the instrument.