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Data Degradation
Data degradation is the gradual Data corruption, corruption of Data (computing), computer data due to an accumulation of non-critical failures in a data storage device. It is also referred to as data decay, data rot or bit rot. This results in a decline in data quality over time, even when the data is not being utilized. The concept of data degradation involves progressively minimizing data in interconnected processes, where data is used for multiple purposes at different levels of detail. At specific points in the process chain, data is irreversibly reduced to a level that remains sufficient for the successful completion of the following steps Manifestations Primary storages Data degradation in dynamic random-access memory (DRAM) can occur when the electric charge of a bit in DRAM disperses, possibly altering program code or stored data. DRAM may be altered by cosmic rays or other high-energy particles. Such data degradation is known as a soft error. ECC memory can be used to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Corruption
Data corruption refers to errors in computer data that occur during writing, reading, storage, transmission, or processing, which introduce unintended changes to the original data. Computer, transmission, and storage systems use a number of measures to provide end-to-end data integrity, or lack of errors. In general, when data corruption occurs, a Computer file, file containing that data will produce unexpected results when accessed by the system or the related application. Results could range from a minor loss of data to a system crash. For example, if a Document file format, document file is corrupted, when a person tries to open that file with a document editor they may get an error message, thus the file might not be opened or might open with some of the data corrupted (or in some cases, completely corrupted, leaving the document unintelligible). The adjacent image is a corrupted image file in which most of the information has been lost. Some types of malware may intentional ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Floppy Disk
A floppy disk or floppy diskette (casually referred to as a floppy, a diskette, or a disk) is a type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined with a fabric that removes dust particles from the spinning disk. The three most popular (and commercially available) floppy disks are the 8-inch, 5¼-inch, and 3½-inch floppy disks. Floppy disks store digital data which can be read and written when the disk is inserted into a floppy disk drive (FDD) connected to or inside a computer or other device. The first floppy disks, invented and made by IBM in 1971, had a disk diameter of . Subsequently, the 5¼-inch (133.35 mm) and then the 3½-inch (88.9 mm) became a ubiquitous form of data storage and transfer into the first years of the 21st century. 3½-inch floppy disks can still be used with an external USB floppy disk drive. USB drives for 5¼-inch, 8-inch, and other-size floppy disks are rare ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Punched Cards
A punched card (also punch card or punched-card) is a stiff paper-based medium used to store digital information via the presence or absence of holes in predefined positions. Developed over the 18th to 20th centuries, punched cards were widely used for data processing, the control of automated machines, and computing. Early applications included controlling weaving looms and recording census data. Punched cards were widely used in the 20th century, where unit record machines, organized into data processing systems, used punched cards for data input, data output, and data storage. The IBM 12-row/80-column punched card format came to dominate the industry. Many early digital computers used punched cards as the primary medium for input of both computer programs and data. Punched cards were used for decades before being replaced by magnetic storage and terminals. Their influence persists in cultural references, standardized data layouts, and computing conventions such as 80-c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paper Data Storage
Paper data storage refers to the use of paper as a data storage device. This includes writing, illustrating, and the use of data that can be interpreted by a machine or is the result of the functioning of a machine. A defining feature of paper data storage is the ability of humans to produce it with only simple tools and interpret it visually. Though now mostly obsolete, paper was once an important form of computer data storage as both paper tape and punch cards were a common staple of working with computers before the 1980s. History Before paper was used for storing data, it had been used in several applications for storing instructions to specify a machine's operation. The earliest use of paper to store instructions for a machine was the work of Basile Bouchon who, in 1725, used punched paper rolls to control textile looms. This technology was later developed into the wildly successful Jacquard loom. The 19th century saw several other uses of paper for controlling machines. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Disc
An optical disc is a flat, usuallyNon-circular optical discs exist for fashion purposes; see shaped compact disc. disc-shaped object that stores information in the form of physical variations on its surface that can be read with the aid of a beam of light. Optical discs can be reflective, where the light source and detector are on the same side of the disc, or transmissive, where light shines through the disc to be detected on the other side. Optical discs can store analog information (e.g. LaserDisc), digital information (e.g. DVD), or store on the same disc (e.g. CD Video). Their main uses are the distribution of media and data, and long-term archival. Design and technology The encoding material sits atop a thicker substrate (usually polycarbonate) that makes up the bulk of the disc and forms a dust defocusing layer. The encoding pattern follows a continuous, spiral path covering the entire disc surface and extending from the innermost track to the outermost track ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disc Rot
Disc rot is the tendency of CD, DVD, or other optical discs to become unreadable because of chemical deterioration. The causes include oxidation of the reflective layer, reactions with contaminants, ultra-violet light damage, and de-bonding of the adhesive used to adhere the layers of the disc together. Causes In CDs, the reflective layer is immediately beneath a thin protective layer of lacquer, and is also exposed at the edge of the disc. The lacquer protecting the edge of an optical disc can usually be seen without magnification. It is rarely uniformly thick; thickness variations are usually visible. The reflective layer is typically aluminium, which reacts easily with several commonly encountered chemicals such as oxygen, sulfur, and certain ions carried by liquid water. In ordinary use, a surface layer of aluminium oxide is formed quickly when an aluminium surface is exposed to the atmosphere; it serves as passivation for the bulk aluminium with regard to many, but not all, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BD-R
Blu-ray Disc Recordable (BD-R) and Blu-ray Disc Recordable Erasable (BD-RE) refer to two direct-to-disk recording, direct to disc optical disc recording technologies that can be recorded on to a Blu-ray-based optical disc with an optical disc recorder. BD-R discs can only be Write once read many, written to once, whereas BD-RE discs can be erased and re-recorded multiple times, similar to CD-R and CD-RW for a compact disc (CD). #Capacity, Disc capacities are 25 gigabyte, GB for single-layer discs, 50 GB for double-layer discs, 100 GB ("BDXL") for triple-layer, and 128 GB ("BDXL") for quadruple-layer (in BD-R only). The minimum speed at which a Blu-ray Disc can be written is 36 megabits (4.5 megabytes) per second. As of 2024, one of the primary pioneers of the Blu-ray disc, Sony, is winding down production of recordable Blu-ray discs in its plant in Tagajō, Japan. Sony plans to gradually cease its manufacturing of optical media, including recordable Blu-ray disc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DVD-R
DVD recordable and DVD rewritable are a collection of optical disc formats that can be written to by a DVD recorder and by computers using a DVD writer. The "recordable" discs are write-once read-many (WORM) media, where as "rewritable" discs are able to be erased and rewritten. Data is written (" burned") to the disc by a laser, rather than the data being "pressed" onto the disc during manufacture, like a DVD-ROM. Pressing is used in mass production, primarily for the distribution of home video. DVD±R (also DVD+/-R, or "DVD plus/dash R") is a shorthand term for both DVD+R and DVD-R formats. Likewise, the term DVD±RW refers to both rewritable disc types, the DVD+RW and the DVD-RW. DVD±R/W (also written as, DVD±R/RW, DVD±R/±RW, DVD+/-RW, DVD±R(W) and other arbitrary ways) handles all common writable disc types, but not DVD-RAM. A drive that supports writing to all these disc types including DVD-RAM (but not necessarily including cartridges or 8cm diameter discs) is ref ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD-R
CD-R (Compact disc-recordable) is a digital media, digital optical disc data storage device, storage format. A CD-R disc is a compact disc that can only be Write once read many, written once and read arbitrarily many times. CD-R discs (CD-Rs) are readable by most CD readers manufactured prior to the introduction of CD-R, unlike CD-RW discs. History Originally named CD Write once read many, Write-Once (WO), the CD-R specification was first published in 1988 by Philips and Sony in the Rainbow Books, Orange Book, which consists of several parts that provide details of the CD-WO, CD-MO (Magneto-Optic), and later CD-RW (Re Writable). The latest editions have abandoned the use of the term ''CD-WO'' in favor of ''CD-R'', while ''CD-MO'' was rarely used. Written CD-Rs and CD-RWs are, in the aspect of low-level encoding and data format, fully compatible with the audio CD (''Red Book'' CD-DA) and data CD (''Yellow Book'' CD-ROM) standards. The Yellow Book standard for CD-ROM only speci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Storage
Optical storage refers to a class of data storage systems that use light to read or write data to an underlying optical media. Although a number of optical formats have been used over time, the most common examples are optical disks like the compact disc (CD) and digital versatile disc (DVD). Reading and writing methods have also varied over time, but most modern systems use lasers as the light source and use it both for reading and writing to the discs. '' Britannica'' notes that it "uses low-power laser beams to record and retrieve digital (binary) data." Overview Optical storage is the storage of data on an optically readable medium. Data is recorded by making marks in a pattern that can be read back with the aid of light, usually a beam of laser light precisely focused on a spinning optical disc. An older example of optical storage that does not require the use of computers, is microform. There are other means of optically storing data and new methods are in developmen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decomposition
Decomposition is the process by which dead organic substances are broken down into simpler organic or inorganic matter such as carbon dioxide, water, simple sugars and mineral salts. The process is a part of the nutrient cycle and is essential for recycling the finite matter that occupies physical space in the biosphere. Bodies of living organisms begin to decompose shortly after death. Although no two organisms decompose in the same way, they all undergo the same sequential stages of decomposition. Decomposition can be a gradual process for organisms that have extended periods of dormancy. One can differentiate ''abiotic'' decomposition from ''biotic'' decomposition ( biodegradation); the former means "the degradation of a substance by chemical or physical processes", e.g., hydrolysis; the latter means "the metabolic breakdown of materials into simpler components by living organisms", typically by microorganisms. Animals, such as earthworms, also help decompose the organ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
