BUS610: Business Intelligence and Analytics

Characteristics

Optical Disc

An optical disc is a flat, circular disc that stores data and is made out of a very strong plastic called polycarbonate substrate. This helps to protect the disc with many layers of coating. Data on these discs are read optically, which means that they store data using laser beams. Data can be stored on one or both sides of the disc. The track, which is a single spiral around the disc, spins from inside the center track (or groove) to the outermost track for the data to be read. Most people today have already switched from VHS movies to DVD movies, and now to Blu-ray DVDs. The advancement in technology has made viewing and burning capabilities for DVDs and CDs much more beneficial. These optical discs do not degrade, like VHS and magnetic media do. Optical discs are used in our every day lives for storage, backing up, photos, movies, music, and much more.

Read only discs are molded and stamped to show the data so that it can only be read (and not over written). This happens with most CDs for music and software, and DVDs for movies. A recordable or rewritable optical disc with a CD or DVD uses a laser to represent the data. An example of this would be burning a CD for music, or an iMovie project to a DVD. There is a complex process that takes place when writing the data on the optical disc. To mold or stamp the discs, bumps (called pits) are formed on the disc's surface. The places that are not changed on the optical discs are called lands. Switching from a pit to a land represents a 1 (like discussed in the system unit). CD discs use infrared lasers, DVDs use red lasers, and Blu-ray discs use blue-violet lasers. These different types of lasers are used to store different amounts of data at a more compact size.

Optical drives are the machines that read the discs of CDs, DVDs, and BD drives. Many households have switched to Blu-ray DVD players. However, users are upset because only BD discs can be played on BD drives which is considered a hassle to some. These drives are also used to burn data on the discs.

History

Gnome-dev-removable

Optical disks were invented in 1958 by David Paul Gregg, he patented them. James T. Russell was then the first person to have made a recording audio digitally to an optical disk. Later Sony and Phillips research physicists made the CD's we know today that can store large amounts of data. For this first generation of CD's they could hold up to 75 minutes of audio with 650Mb of storage. The purpose of the first generation was only for audio and computer software. They were capable of making a CD video but the VHS cassette was more popular at the time and it cost too much to produce them. These CD's were read with an infrared laser. Later the second generation could store even more data and was used for video. They were read with a visible laser light which allowed the lands a pits to be smaller thus creating more space to for more data. They allowed 4.7 GB of storage on a standard single disc. The third generations are being developed to create even more storage available, like a Blu-ray disc. The Blu-ray disc use blue-violet lasers. There is even a fourth generation to be discovered that could hold up to one terabyte of storage.

CDs, DVDs, and BDs

Recordable CDs

Read-only optical discs include CD-ROM, DVD-ROM, and BD-ROM discs. These are CDs or DVDs that come with something already prerecorded on them and they cannot be cleared. This is because the pits that are molded into the surface of the disc are permanent. There are also read-only discs for video games and different software.

Recordable optical discs are also sometimes referred to as write-once discs. This means that these can be written to but the discs cannot be reused or erased. These include CD-R, DVD-R, DVD+R, and BD-R discs. The difference between the DVD-R and the DVD+R is the standard being used. There is also a DVD-R DL and a DVD+R DL, which indicates whether or not it is dual layer. Using DVD+R will allow you to instantly eject the DVD without having to wait for the finalized version. It also allows you to record some of the DVD on a personal computer and some of it on the TV. Another feature is that is it 100% compatible with all DVD players. Recordable CDs are often used for backing up files, making music CDs, or sending large files to other people. BD-R discs are used for even larger back ups that need even more storage and they are used for high-definition multimedia files.

Rewritable optical discs include CD-RW, DVD-RW, DVD+RW, and BD-RE discs. These can be written on and then erased and rewritten on. To rewrite on these types of discs they use phase change technology. So basically the rewriteable disc is coated with a metal alloy compound. They then use heating and cooling to write on the disc without making it permanent. These are used for backing up files but they are more convenient than recordable optical discs because they can be used multiple times.

Details about CDs

Small cdisk ubt

Compact Disc (CD) is used to store video, audio, and data in different formats classified in the Rainbow Books. It includes formats like CD-ROM (Compact Disc Read-Only Memory), CD-R (Compact Disc- Recordable), CD-RW (Compact Disc-ReWritable), VCD (Video Compact Disc), photo CD, and Enhanced Music CD. Compact Disc comes in standard 12 cm (120mm) or 8 cm (80mm) in diameter. The most popular is the 12 cm type with a 74- or 80-minute audio capacity and a 650 or 700 MB (737,280,000 bytes) data capacity. The 8 cm type is used in electronic devices like portable compressed digital audio players or data storage products like miniature CD recorders. CD-Rs were invented by Philips and Sony and together with CD-ROM there were about 30 billion CDs sold worldwide in 2004. The high-capacity recordable CDs can hold 90 or 99 min of audio on a 12 cm disc and 30 minutes of audio on a smaller disc (8 cm). The ability to write beyond the manufacturer's declared capacity on a CD-R or CD-RW disc is called oversizing or overburning. However, Overburning might affect product warranties and result in lost data so it is not recommended. However, it might affect product warranties and result in lost data so it is not recommended. These days, more and more compact discs are being replaced by flash drives or downloading.

Details about BDs

Blu-ray disc (BD-RE)

The newest form of optical disk is the Blu-ray disk (BD), which was officially announced on February 19, 2002, and was first available to consumers on April 10, 2003. Blu-ray gets its name from the blue laser that reads it (as opposed to the red laser that reads DVDs). BDs have more storage capability than its predecessor and also has a variety of new functions that DVDs did not have, such as the following: record high-definition television without losing quality, record one program while watching another at the same time, automatically search for an empty space on the disc to avoid recording over a program, and access the Web to download subtitles and other features. The way BDs achieve this is by having smaller pits, so more data can be stored, and having a laser with a shorter wavelength, a blue laser, that can read more precisely. DVDs could not fit more information because a red laser is not precise enough to read pits that are packed together as close as the pits on a BD. Pits on a DVD could be a minimum of 0.4 microns, while BDs pit minimum is 0.15 microns. Also, the track pitch on BDs has been reduced from 0.74 microns to 0.32 microns. Because of all these improvements, a BD can hold more than 25 GB of information, which is five times the amount that a DVD can hold.

How to Repair a Scratched CD or DVD

Xbox360 scratch

Compact Discs (CDs) and Digital Video Discs (DVDs) both store their data externally on a disk. Unfortunately, as we all have experienced, these disks often times get scratched, making the CD or DVD skip, or sometimes not work at all. Depending on where the scratch is located, the disc may or may not be able to be repaired. It seems scratches on the top, shiny part of the disc are harder to repair than if the scratch is on the lower plastic part of the disc. Although some companies are developing scratch resistant discs, their efforts may be in vain due to technology moving fast past these forms of storage. For those people still utilizing CDs and DVDs, scratches on them can be annoying and frustrating. There are a few simple remedies consumers can try to repair their discs and attempt to get more life out of them. The first step is to clean the disc with a mild soap and water. This can help by removing any finger prints that may be hindering the disks' functionality. Users then want to dry the disc with lint free cloth, as even the smallest fibers can scratch and damage the disc further. After the disc is dry, the user can then apply toothpaste to it, smoothing it out in a straight direction from the disc's center. After this, the disc should be rewashed to remove any excess paste. If this procedure is successful, the toothpaste will fill in the scratches so the disc can again be played with little or no skipping. Often times, scratches to these discs are too severe for this method to help. If that is the case, companies advise consumers to discard the disc altogether. Luckily, as technology continues to advance, the reliance on these forms of storage is decreasing, and with it, the annoyance and frustration that comes from their malfunctioning.

Are Optical Discs Becoming Obsolete?

You don't need this anymore

While Optical Discs may be excellent media of storage, their necessity has now come into question with the ever advancing of technology. Floppy disks used to be what everyone used to store information and that soon became obsolete. As the cycle of technology inevitably catches up to optical discs, they may no longer be as useful as before. First, there's the rise of technologies that no longer make use of optical discs because of the size. Most tablets and laptops no longer having optical drives because they take up space and may make the device less portable. Next is the fact that there are many more storage options that have become available that are much more convenient. Cloud storage has been on the rise as well as regular flash drives have had an increase in storage capacity as compared to optical discs. Then there's the fact that many media companies have moved to a disc free environment. Streaming services have made renting CDs and DVDs obsolete. Gamers no longer buy physical discs but rather just download a digital copy. Even music has moved to a streaming service that makes buying physical albums and LPs more of a novelty. Finally, there is the fact that consumers want what's convenient and optical discs are no longer as convenient as they used to be. However which way you look at it, the advancement of technology will eventually make anything obsolete. The future holds many possibilities for other forms of storage and that too will eventually become obsolete.

Smart Cards

Back of a smart card

A smart card is a credit card-sized piece of plastic that contains computer circuitry, like a processor, memory, and storage. Smart cards can only store low amounts of data, around 8 kilobytes of RAM or 346 kilobytes of ROM. The processor is actually a microprocessor, and it is situated under a gold contact pad on one side of the card. The processor in the card has the capability to encrypt the data so that only authorized access is allowed. The purpose of a smart card is to store sensitive data securely, usually identification or digital cash. Unlike a credit card where all of the information on it can be read easily and identity theft is more common, the smart card cannot be physically read and it puts up a difficult fight against a hacker trying to access the data. To make it even more secure, some smart cards actually store biometric data to even further ensure that only the correct user can use it. A smart card is used by sliding it through, placing it in, or placing it in front of a smart card reader. This allows for the smart card reader to interact with the smart card by transferring the data on the card. An example of this is having a smart card reader on a locked door. The authorized user, a government official, places their smart card in front of the smart card reader on the door and the data on the card would be read by the reader. Once the reader acknowledges that the government official is allowed in, the reader would unlock the door and the official could walk in. All in all, the smart card is a great new technology that is making transactions and equipment safer.

Large Computer Storage Systems

The original storage system for major company Walmart

Major companies and organizations require large computer systems that can store their massive amounts of data. The amount of data that the world needs to store is growing at a phenomenal rate, predicted to increase by half in 2014 alone. Regulations have been put in place by the government to make companies keep data and information about clients and customers. This information is stored in the same types of hardware that everyday consumers would use but on a much larger scale. Many hard drives are connected and used together to increase the amount of data that can be saved. A leader in the industry, IBM, is currently at work on the largest storage server ever with an incredible 120 petabytes of space. This server is going to be comprised of over 200,000 standard hard drives connected in a large warehouse. Some companies may also use a system called RAID, or redundant arrays of independent disks. This method uses two or more hard drives which contain redundant copies of the same data in order to process and access it faster. This can be done one of two ways. The first method, disk striping, actually separates and spreads the files out over multiple hard drives while the second method, disk mirroring, has an exact duplicate of the information on the first.