Monday, March 17, 2008
Features of Mobile phone
Monday, March 10, 2008
Uses & Design of Supercomputer
Supercomputers are used for extremely calculation-intensive tasks such as weather forecasting, climate research (including research into global warming), molecular modeling (computing the structures and properties of chemical compounds, biological macromolecules, polymers, and crystals), physical simulations (such as simulation of airplanes in wind tunnels, simulation of the detonation of nuclear weapons, and research into nuclear fusion), cryptanalysis, and the like. Military and scientific agencies are important users.
Design
Supercomputers traditionally gained their speed over conventional computers through the use of inventive designs that allow them to perform many tasks in parallel, as well as complex detail engineering. They tend to be specialized for certain types of computation, generally numerical calculations, and perform poorly at more general computing tasks. Their memory hierarchy is very carefully designed to make certain the processor is kept fed with data and instructions at all times—in fact, much of the performance difference between slower computers and supercomputers is due to the memory hierarchy design and componentry. Their I/O systems have a propensity to be designed to support high bandwidth, with latency less of an issue, because supercomputers are not used for transaction processing.
As with all highly parallel systems, Amdahl's law applies, and supercomputer designs devote huge effort to eliminating software serialization, and using hardware to accelerate the remaining bottlenecks.
Tuesday, March 4, 2008
Earth science in Natural Science
Although mining and precious stones have been human interests right through the history of civilization, their development into the sciences of economic geology and mineralogy did not occur until the 18th century. The learning of the earth, particularly palaeontology, blossomed in the 19th century and the growth of other disciplines like geophysics in the 20th century led to the development of the theory of plate tectonics in the 1960s, which has had a similar impact on the Earth sciences as the theory of evolution had on biology. Earth sciences nowadays are closely linked to climate research and the petroleum and mineral exploration industries.
Monday, February 25, 2008
Paper Density
* Expressed in grams per square metre (g/m²), paper density is also called as grammage. This is the evaluate used in most parts of the world.
* Expressed in conditions of the mass (in pounds) of a ream of 500 (or in some cases 1000) sheets of a specified (raw, still uncut) basis size, paper density is called as basis weight. The base size and area used here based on the product type. This convention is used in the
Tuesday, February 19, 2008
Photographic Printing
The procedure consists of three major steps, performed in a photographic darkroom or within an automated photo printing machine:
1. Exposure of the picture onto the sensitized paper using a contact printer or enlarger.
2. Processing of the latent image through a more than one step chemical immersion process.
1. Development of the uncovered image.
2. Optionally Stopping improvement by neutralizing, diluting or removing developing agent.
3. Fixing the final print by dissolving remaining unexposed/undeveloped light-sensitive liquid.
4. Washing thoroughly to eliminate chemicals used in processing, protecting the finished print from fading and decay.
3. If finished on glossy paper, ferrotyping to enhance the reflective gloss.
4. Optional Toning of the print through extra chemical processes.
5. Texturing and drying of the finishing print.
Monday, February 11, 2008
Inkless Printers
Wednesday, February 6, 2008
Modchip
Almost all modern console gaming systems have hardware-based schemes which ensure that only formally sanctioned games may be used with the system and implement regional lockout similar to the scheme used in DVD movies. The particular technical nature of these DRM systems varies by system, and may include cryptographic signing (Xbox), intentionally unreadable sectors (PlayStation, Sega Saturn), custom optical media (Dreamcast), or some combination thereof. Modchips are available also for some DVD players, to defeat region code enforcement and user operation prohibitions.
Modchips in general require some level of technical ability to install. Most commonly, modchips must be soldered on to a console's motherboard, although there are no-solder install kits (which instead rely on the precise positioning of electrical contacts within the case) which work with some revisions of the PlayStation 2 and Xbox hardware.