Thursday, March 29, 2007

Digital photography

Digital photography, as opposite to film photography, uses an electronic sensor to record the image as a portion of electronic data rather than as chemical change on film. Digital cameras now sell more than film cameras and include features not found in film cameras such as the ability to shoot video and record audio. Some other devices, such as mobile phones, now consist of digital photography features.

charge-coupled machine (CCD)
CMOS semiconductor
There are also two main types of antenna mechanisms:

Area array
Linear array :An area array sensor reads the entire image plane at once, whereas a linear collection antenna works more like a flatbed scanner. Since this machinery predates area arrays, it was accessible earlier, in professionally-priced cameras. With the initiation of area array sensors, consumer digital cameras became available for noticeably lower prices.

Multifunctionality and connectivityExcept for some linear array type at the highest-end and simple web cams at the lowest-end, a digital memory device is usually used for store images, which may then be transfer to a computer later.

Friday, March 23, 2007

Aircraft carrier

An aircraft carrier is a warship whose main role is to deploy and recover aircraft—in effect acting as a sea-going airbase. Aircraft carriers thuo depend on local bases for land-based aircraft. Modern navies, who work such ships, treat aircraft carriers as the centerpiece of the fleet, a role before played by the battleship. The change, part of the growth of air power as a significant part of warfare, took place during World War II. Unescorted carriers are careful vulnerable to attack by other ships, aircraft, submarines or missiles and so travel as part of a carrier battle group.
Flight deck configuration
Aircraft carriers have a flat-top deck, the flight deck that serves as a take-off and landing area for aircraft. Aircraft take off to the front, into the wind, and land from the rear. The carrier steams at up to 35 knots (65 km/h) straight into the wind throughout take-off in order to increase the apparent wind speed, thereby reducing the necessary speed of the aircraft relative to the ship. A steam-powered catapult is used to propel the aircraft forward assisting the power of its engines and allowing it to take off in a shorter distance than would otherwise be necessary, even with the headwind effect of the ship's course. on the other hand, when landing on a carrier, aircraft rely upon a tailhook that catches on arrestor wires stretched across the deck to bring them to a stop in a shorter distance than normal. Since the end of WWII it has been ordinary to direct the landing recovery area off to port at an angle to the line of the ship. This allows launching of aircraft at the same time as others land.
The above deck areas of the warship are intense to the starboard side of the deck in a comparatively small area called an "island". Only a very few carriers have ever been intended or built without an island and such a configuration has not been seen in a fleet sized carrier.
A more recent configuration, used by the Royal Navy, has a 'ski-jump' ramp at the front end of the flat deck. This was developed to help launch VTOL (or STOVL) aircraft (aircraft that are able to take off and land with little or no forward movement) such as the Sea Harrier. Though the aircraft are capable of flying vertically off the deck, using the ramp is more fuel efficient. As catapults and arrestor cables are unnecessary, carriers with this arrangement reduce weight, complexity, and space wanted for equipment.

Monday, March 19, 2007

White flight

White flight is a colloquial term for the demographic tendency of upper and middle class white people moving away from (predominantly non-white) inner cities, finding new homes in nearby suburbs or even moving to new locales completely, e.g. from the Rust Belt to the Sun Belt. In some of the United States' largest cities, the trend reversed itself in the 1990s
White flight in the United States
White flight has been taking place in many American cities and regions, particularly in the Northeastern, Midwestern, and Western sections of the United States since the 1950s.
The effects of white flight have been important for the cities that have been hit by this phenomenon, in particular Detroit, Michigan and St. Louis, Missouri, which lost more than half of their peak populations mainly due to white flight. In New York City many whites have moved from parts of the Bronx and Brooklyn to Staten Island, suburban Long Island, and suburban New Jersey. Other U.S. cities that have been obviously affected by white flight include Philadelphia, Pennsylvania, Cleveland, Ohio, the West and South Sides of Chicago, Illinois, the Greater Los Angeles Area, Baltimore, Maryland, Newark, New Jersey, and numerous smaller cities.

Tuesday, March 13, 2007

Quinzhee

A quinzhee, or quinzee, is a kind of snow shelter made by making a pile of snow, waiting for it to settle together, then hollowing out the inside. In difference, an igloo is made by carefully stacking cut blocks of snow.
It is not easy to make a quinzhee, although it will be warmer and stronger if certain techniques are carefully followed. For strength, the quinzhee needs to be a dome and the lower walls must not support too much weight. The walls should be very thick at the base and get slightly thinner towards to the top of the dome.
For warmth, the entrance of the quinzhee should be a tunnel with an upward sloping floor such that the floor is somewhat higher than the top of the entrance.
Caution: Care must be taken when camping conditions are marginal, such as at temperatures near freezing, or when it is raining. Under these conditions the ceiling of the quinzhee may collapse gradually because the snow is soft. Moreover, the entrance tunnel may become too narrow to permit escape. Hence, under these conditions it is unsafe to spend too much time inside the structure because you may become trapped.

Thursday, March 08, 2007

Graphic design

Graphic design is a type of communicating visually using text and/or images to present information, or promote a message. The art of graphic design embraces a range of cognitive skills and crafts with typography, image development and page layout. Graphic design is applied in communication design and fine art. Like other forms of communication, graphic design often refers to both the process (designing) by which the communication is created, and the products (designs) such as creative solutions, imagery and multimedia compositions. Graphic design is usually applied to static media, such as books, magazines and brochures. Additionally, since the arrival of computers, graphic design is utilized in electronic media - often referred to as interactive design, or multimedia design.
There are varying degrees of graphic design. Graphic designer participation may range from verbally communicated ideas, to visual rough drafts, to final production. In commercial art, client edits, technical preparation and mass production are generally required, but regularly not considered to be within the scope of graphic design unless the client is also a graphic designer.

Sunday, March 04, 2007

Tourism in New York City

40 million foreign and American tourists visit New York City each year.Major destinations comprise of the Empire State Building, the Statue of Liberty, Broadway productions, scores of museums from the El Museo del Barrio to the Intrepid Sea-Air-Space Museum (closed until 2008 for repairs), Washington Square Park, the Bronx Zoo and New York Botanical Garden, luxury shopping along Fifth and Madison Avenues, and events such as the Halloween Parade in Greenwich Village, the Tribeca Film Festival, and free performances in Central Park at Summer stage. Many of the city's ethnic enclaves, such as Jackson Heights, Flushing, and Brighton Beach are major shopping destinations for first and second generation Americans up and down the East Coast.
New York City has 28,000 acres (113 km²) of parkland and 14 miles (22 km) of public beaches. Manhattan's Central Park, intended by Frederick Law Olmsted and Calvert Vaux, is the most visited city park in the United States.Prospect Park in Brooklyn, also planned by Olmsted and Vaux, has a 90 acre (36 Hectare) meadow. Flushing Meadows Park in Queens, the city's third largest, was the setting for the 1939 World's Fair and 1964 World's Fair.
New York's food culture, influenced by the city's immigrants and large number of dining patrons, is diverse. Jewish and Italian immigrants made the city famous for bagels and New York style pizza. Some 4,000 mobile food vendors approved by the city, many immigrant-owned, have made Middle Eastern foods such as falafels and kebabs standbys of contemporary New York street food.The city is also home to many of the finest haute cuisine restaurants in the United States.