What are the factors for a home theater

There are two things that people usually care for when it comes to quality in a Desktop with noticeable qualities. They are the video and audio. Apart from the computing capacities of a PC, these two factors stand out to provide exterior view to a system. In the video part it is the graphics card and display devices with some drivers take their part. While in the audio part it is the speaker basically.
Setting up a home theater needs some basic reasons for which it is going to be installed and it also have factors that determine its quality and effectiveness? Some of the reasons why a proper speaker system is needed are maybe for gaming or digital home theater. For either of these reasons the factors are same but have varying values for each. The factors are frequency, area of coverage, power, and control provided. The amount of quality of a product also depends on the prize to be rendered for it.

Biometrics..

It can be defined as the technique of studying the physical characteristics of humans to establish identity.

The increased need for security, and it is also convenient to simply place finger on to a scanner instead of remembering a complex password.

The concept is simple. Pre-stored database is used to compare your finger impression with a record already in database. When a match is found, access is granted. A fingerprint is like waves with ridges and valleys, they are scanned to verify the authenticity.

An optical (CCD) scanner similar to the ones used in digital cameras is used for scanning. It is an array of light sensitive diodes .When they come in contact with light, they generate an electrical signal.An ADC system that converts electrical signal into digital. The scanner will also have a light source to illuminate the finger.

But before checking with the database, it checks for contrast, sharpness and sheer quality of the image captured. If the image quality seems correct enough, the scanner compares the captured fingerprint with those in the database to find any match.

Scanning and matching the entire finger surely consumes a lot of processing. Instead, the scanners could compare specific features of the fingerprint, called as minutiae. They are points where ridge lines end or bifurcation occurs.

A specific number of minutiae is matched for the print to be accepted. But it is being proved that it is possible to fool by using fake prints.

Speakers Uncovered

Speakers, are devices technically called transducers, which transform one form of energy into another. i.e Speaker are devices that converts electrical energy into sound energy(acoustic).

Basically in a speaker, a paper diaphragm vibrates in accordance with the electrical signal fed into it. Flashing some light on its components shows a powerful ring magnet, a voice coil that is wound around a paper cylinder.

Moving to its functionality, the principle behind is electromagnetism. The interaction between the electromagnetic coil and permanent magnet drives the speaker to produce sound.

Diaphragm,sound source for a speaker. The voice coil is attached to the centre of the paper diaphragm at one side, which compresses and rarefies the particles around, thus producing sound.

Other than this sound enclosures play a vital role in audio experience. The air flow through the enclosure affects the bass sounds through undesirable harmonics. Its dimensions have an effect on the wave resonance.

Deep into the technicals, considering an amplifier.It has two signals the input and the output signal. Naturally for high gain, input impedance(resistance) should be as high as possible and output impedance should be as low as possible.

Finally, speaking about multiple speakers, positioning the speakers is very important.Because reflections cause the sound to be heard across all areas of a room or hall.Consider as if fitting light for your room or hall while for speakers as both are waves,this would produce great results as well.

Blind catalogue for mobile phone features.

Brand ----------------- Model(s)----------------- Range---------- Feature-My rating

Sony Ericsson---------W200i,W610i,W810i------ <10k>15k--------------- Music-5*

-----------------------K550i,K750i------------------------------------ cybershot-4

-----------------------K810i,K790i---------------- 15&11k------------ camera(3.2 Mp)-5

-----------------------K850i ------------------------------------------ camera-5*


Nokia -----------------N73,Xpress Music ----------10-15k------------Music-4.5
-----------------------5160 and 5130 ---------------------------------camera-5

------------------------N95------------------------ >15k-------------- Music-5*
-------------------------------------------------------------------------camera(5mp)-5*

------------------------N70 ------------------------------------------- camera-4


Apple ------------------Iphone---------------------->15k -------------Music-5

File systems

Files are nothing but a sequence of bytes on memory blocks called sectors. There are some file systems which have journaling and versioning.

The properties for Journaling file system is taking log for changes made to files and for versioning file systemis taking periodic backup also allowing several versions of same file.File systems based on Operating Systems can be organized as follows:

Windows:
New Technology File System (NTFS),
File Allocation Table (FAT).

Linux:
ext, ext2, ext2fs, NSS, ReiserFS

Mac OS X:
Hierarchical filesystem (HFS),
Macintosh filesystem (MFS),
Xsan Disk-based filesystems ,(Solid-state media file systems)

Flash Memory

Flash memory is nothing but the most popularly called USB drive. At the most basic level, flash memory is composed of array of gate transistors called cells.

These cells has two types of gates: NAND and NOR . They are also classified in two ways depending on how they store data, they are single level cells and multi level cells

SLC can store only one bit at a time, while MLC store more than one bit per cell,just by varying the electrical charges. Thus MLC devices will be able to store more data than the SLC devices.

These devices are already in the market, though they cost more than SLC ones.

Multi-level cells are created by stacking cells of the same size, i.e doubling the capacity. This is the type of memory used in iPods. Though, it doubles the capacity, access speeds is reduced.

Now at present flash technology has developed which inserts silicon columns between layers without stacking multiple layers.

Digital Camera

So how each snap that you click turns out into a good quality digital image and got stored in the memory card of your digital camera?

Firstly, the outer light get passed through the lens and directed to the CCD(charge coupled device).

Then, the image is been focused on the CCD.

After which, an ADC (analogue-to-digital converter) converts the CCD grabbed image into digital signals.

This data was sent to the DSP(Digital Signal Processor) which creates the original image and also compresses it.

Finally, the image is stored on the inbuilt memory or in the memory stick.

Web getting updated.

For the cause of being able to adapted to the new technology that evolve each day,Every software is being updated, while every hardware is being upgraded.

The same now goes to internet, Web 2.0 in the verge of updating our current internet.It aims in providing the end user with what he actually needs?

This system will be able to direct the user to appropriate website by optimized search using user feedback(input). So there wont be a need to open several search result pages.

This is not the only thing as to highlight, there is a whole lot of features to add, I hope presenting them in another post very soon, after I get a detail knowledge about them.