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Interleaving
Interleaving may refer to: * Interleaving, a technique for making forward error correction more robust with respect to burst errors * An optical interleaver, a fiber-optic device to combine two sets of dense wavelength-division multiplexing (DWDM) signals * Interleaved memory, a technique for improving the speed of access to memory * Interleaving (data), the interspersing of fields or channels of different meaning sequentially * Interleaving (disk storage), a technique for improving the speed of access to blocks on disk storage * Interleaved posting, an e-mail posting style * Interleaving (bitmaps), a technique for encoding bitmapped images * Interleaving the bits of the binary representation of coordinate values to produce a Z-order (curve) for points * Interleave sequence In mathematics, an interleave sequence is obtained by merging two sequences via an in shuffle. Let S be a set, and let (x_i) and (y_i), i=0,1,2,\ldots, be two sequences in S. The interleave sequence is de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interleaved Memory
In computing, interleaved memory is a design which compensates for the relatively slow speed of dynamic random-access memory (DRAM) or core memory, by spreading memory addresses evenly across memory banks. That way, contiguous memory reads and writes use each memory bank in turn, resulting in higher memory throughput due to reduced waiting for memory banks to become ready for the operations. It is different from multi-channel memory architectures, primarily as interleaved memory does not add more channels between the main memory and the memory controller. However, channel interleaving is also possible, for example in freescale i.MX6 processors, which allow interleaving to be done between two channels. Overview With interleaved memory, memory addresses are allocated to each memory bank in turn. For example, in an interleaved system with two memory banks (assuming word-addressable memory), if logical address 32 belongs to bank 0, then logical address 33 would belong to bank 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burst Error-correcting Code
In coding theory, burst error-correcting codes employ methods of correcting burst errors, which are errors that occur in many consecutive bits rather than occurring in bits independently of each other. Many codes have been designed to correct random errors. Sometimes, however, channels may introduce errors which are localized in a short interval. Such errors occur in a burst (called burst errors) because they occur in many consecutive bits. Examples of burst errors can be found extensively in storage mediums. These errors may be due to physical damage such as scratch on a disc or a stroke of lightning in case of wireless channels. They are not independent; they tend to be spatially concentrated. If one bit has an error, it is likely that the adjacent bits could also be corrupted. The methods used to correct random errors are inefficient to correct burst errors. Definitions A burst of length Coding Bounds for Multiple Phased-Burst Correction and Single Burst Correction Codes Say ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interleaving (data)
In computing, interleaving of data refers to the interspersing of fields or channels of different meaning sequentially in memory, in processor registers, or in file formats. For example, for coordinate data, :x0 y0 z0 w0 x1 y1 z1 w1 x2 y2 z2 w2 :x0 x1 x2 x3 y0 y1 y2 y3 z0 z1 z2 z3 w0 w1 w2 w3 the former is interleaved while the latter is not. A processor may support permute instructions, or strided load and store instructions, for moving between interleaved and non-interleaved representations. Interleaving has performance implications for cache coherency, ease of leveraging SIMD hardware, and leveraging a computer's addressing modes. (e.g. - interleaved data may require one address to be calculated, from which individual fields may then be accessed via immediate offsets; conversely if only one field is required by index, de-interleaved data may leverage scaled index addressing). See also * AOS vs SOA * Data-oriented design * Locality of reference * Parallel arrays * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Posting Style
When a message is replied to in e-mail, Internet forums, or Usenet, the original can often be included, or "quoted", in a variety of different posting styles. The main options are interleaved posting (also called inline replying, in which the different parts of the reply follow the relevant parts of the original post), bottom-posting (in which the reply follows the quote) or top-posting (in which the reply precedes the quoted original message). For each of those options, there is also the issue of whether trimming of the original text is allowed, required, or preferred. For a long time the traditional style was to post the answer below as much of the quoted original as was necessary to understand the reply (bottom or inline). Many years later, when email became widespread in business communication, it became a widespread practice to reply above the entire original and leave it (supposedly untouched) below the reply. While each online community differs on which styles are appropr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interleaving (disk Storage)
In block storage devices such as hard disk drives, interleaving is a technique used to improve slow system performance by putting data accessed sequentially into non-sequential blocks, typically sectors. The number of physical sectors between consecutive logical sectors is called the interleave skip factor or skip factor. Historically, interleaving was used in *Minimizing missed rotations between instructions on computers storing instructions on a drum memory *Ordering block storage on storage devices such as drums, floppy disk drives and hard disk drives. The purpose of interleaving was to adjust the time difference between when the program was ready to transfer data, and when those data were actually arriving at the drive head to be read. Interleaving was common prior to the 1990s, but faded from use as processing speeds increased. Modern disk storage is not interleaved. Modern operating systems do not use interleaving for, e.g., paging files. Interleaving was used to arrange ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Z-order (curve)
In mathematical analysis and computer science, functions which are Z-order, Lebesgue curve, Morton space-filling curve, Morton order or Morton code map multidimensional data to one dimension while preserving locality of the data points. It is named in France after Henri Lebesgue, who studied it in 1904, and named in US after Guy Macdonald Morton, who first applied the order to file sequencing in 1966. The z-value of a point in multidimensions is simply calculated by interleaving the binary representations of its coordinate values. Once the data are sorted into this ordering, any one-dimensional data structure can be used such as binary search trees, B-trees, skip lists or (with low significant bits truncated) hash tables. The resulting ordering can equivalently be described as the order one would get from a depth-first traversal of a quadtree or octree. Coordinate values The figure below shows the Z-values for the two dimensional case with integer coordinates 0 ≤&nb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Interleaver
{{Unreferenced, date=June 2019, bot=noref (GreenC bot) An optical interleaver is a 3-port passive fiber-optic device that is used to combine (Mux) two sets of dense wavelength-division multiplexing (DWDM) channels (''odd'' and ''even'' channels) into a composite signal stream in an interleaving way. For example, optical interleaver takes two multiplexed signals with 100 GHz spacing and interleaves them, creating a denser DWDM signal with channels spaced 50 GHz apart. The process can be repeated, creating even denser composite signals with 25 GHz or 12.5 GHz spacing. The device can be used in a reverse direction, forming an optical deinterleaver that separates a ''denser'' DWDM signal into ''odd'' channels and ''even'' channels. See schematic diagram. For example, in most DWDM equipment, the standard channel spacing is 100 GHz. But spacing the signal-carrying frequencies every 50 or even 25 GHz can double or even quadruple the number of channels per fiber. Thu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interleaving (bitmaps)
In computing, interlacing (also known as interleaving) is a method of encoding a bitmap image such that a person who has partially received it sees a degraded copy of the entire image. When communicating over a slow communications link, this is often preferable to seeing a perfectly clear copy of one part of the image, as it helps the viewer decide more quickly whether to abort or continue the transmission. Interlacing is supported by the following formats, where it is optional: * GIF interlacing stores the lines in the order 0,8,16,\dots,(8n),\ 4, 12, \dots, (8n+4),\ 2,6,10,14,\dots,(4n+2),\ 1,3,5,7,9,\dots,(2n+1). * PNG uses the Adam7 algorithm, which interlaces in both the vertical and horizontal direction. * TGA uses two optional interlacing algorithms: **Two-way: 0,2,4,\dots,(2n),\ 1,3,\dots,(2n+1), **And four-way: 0,4,8,\dots,(4n),\ 1,5,\dots,(4n+1),\ 2,6,\dots,\ (4n+2),3,7,\dots,(4n+3). * JPEG, JPEG 2000, and JPEG XR (actually using a frequency decomposition hierarchy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
