For compression ratio in data compression data compression ratio Refimprove date May 2009 The compression ... Compression ratio url http www.britannica.com EBchecked topic 130313 compression ratio accessdate 2009 ... the head or combustion chamber has been reduced to 100 cc, then the compression ratio would be proportionally described as 1000 100, or with fractional reduction, a 10 1 compression ratio. A high compression ratio is desirable because it allows an engine to extract more mechanical energy from ... of thermal efficiency, it is because greater compression increases the internal energy ... of the compression. date April 2011 High ratios place the available oxygen and fuel molecules into a reduced space along with the adiabatic heat of compression causing better mixing and evaporation of the fuel droplets. Citation needed reason you should not say adiabatic heat of compression ... usually refers to a process. You should say along with the adiabatic tendancies of the compression process or along with the fact that the compression process is adiabatic. Also it does not really ..., as opposed to energy which is a physical property. date April 2011 Higher compression ratios will however ... of compression ignition, so that a fuel which resists autoignition will cause late ignition which ... of the compression stroke, i.e. when the piston reaches top dead center TDC . Because of the complex shape of this space, it is usually measured directly rather than calculated. Typical compression ratios Petrol gasoline engine Due to engine knocking pinging detonation , the compression ratio ... automotive engines built for high performance from 1955 1972 had compression ratios as high ... to adopt a very fast circular rotation in the cylinder during compression that provides quicker ... to delay ignition timing, it is possible to manufacture gasoline engines with compression ratios of over ..., Jaguar released a cylinder head that allowed up to 14 1 compression but settled for 12.5 1 in production ... more details
Image Lepakshi2.jpg thumb right 150px Columns A compression member is a general class of structural elements of which a column is the most common specific example. Description For a compression member, such as a column, the principal stress comes mainly from axis of rotation axial forces, that is forces that fall along one line, usually the centerline. ref name efunda cite web url http www.efunda.com formulae solid mechanics columns intro.cfm title Compression member publisher accessdate 2007 01 08 ref The loading capacity of a short column is determined by strength limit of the material. The strength of a column of intermediate size is limited by its degree of inelasticity. A long column is constrained by the elastic limit that is by amount of buckling . ref name efunda See also Arch Brown truss List of structural elements Truss Strut Notes references External links http www.digitalengineeringlibrary.com dxreader opendxreader.asp?chapterid p2000a1fb9970525001 Columns and other compression members http www.sandsmachine.com ac comp.htm Bicycle compression members http pubsindex.trb.org document view default.asp?lbid 731981 Numerical load numbers for reinforced concrete compression members Category Columns and entablature element arch stub cs Podp rn l nek ... more details
merge Compression garment discuss Talk Compression sportswear Merger proposal date February 2012 Compression sportswear is clothing usually worn by athletes. They may be shorts, tights or underwear. They are form fitting garment s and when worn cover the athlete s waist to mid or lower thigh. These garments are often made from a spandex type material. The main benefits of compression sportswear is that it keeps the muscles warm to prevent muscle strain and fatigue, and wick sweat away from the body to prevent chafing and rashes. In addition, there is some evidence that compression shorts may enhance athletic performance. ref cite journal doi 10.1080 0264041031000101971 author Doan BK, Kwon YH, Newton RU, et al. title Evaluation of a lower body compression garment journal J Sports Sci volume 21 issue 8 pages 601 10 year 2003 month Aug pmid 12875311 ref Compression sportswear also helps to keep undergarments in place, and for certain sports, like baseball and softball , come with padding at the hips to protect players from injuries due to sliding. There are many types of compression garments that serve a similar function, such as compression t shirts, socks, sleeves, and tights . Common ..., and garments such as compression shorts have seen an increase in popularity, arguably because of their comparable ... title Where have all the jockstraps gone? work Slate Magazine 2005 07 22 ref Compression shorts .... In those situations, athletes wear compression shorts under the skirt so if they fall over and their skirts ..., compression shorts are often referred to as spandex shorts, the material with which they are often manufactured. Benefits The alleged benefits of wearing compression tights are Improving athletic ... last8 Volek last9 Putukian title Influence of compression therapy on symptoms following soft tissue ... JS first9 M ref Reducing muscle soreness during post workout recovery As an alternative to compression ... and intensity of training and competition. See also Compression shorts Rugby shorts Sports clothing ... more details
In computing , solid compression refers to a method for data compression of multiple files, wherein all the compressed files are concatenated and treated as a single data block. Such an archive is called a solid archive. It is used natively in the 7z ref cite web url https www.edenwaith.com support guitar help man 7za.html title 7za man page accessdate 2010 01 24 quote ms on solid archive on ref and RAR ref cite web title RAR Frequently Asked Questions FAQ url http pot pourri.fltr.ucl.ac.be files ARCH RAR FAQ.TXT accessdate 2010 01 24 ref formats, as well as indirectly in Tar file format tar based formats such as code .tar. gzip gz code and code .tar. bzip2 bz2 . code By contrast, the ZIP file format ZIP format is not solid because it stores separate compressed files even though solid compression can be portably ZIP file format Advantages and disadvantages emulated . The term is ostensibly because the data is compressed as a single solid block, rather than as individual files. Explanation Compressed file formats often feature both compression storing the data in a small space and file archiver archiving storing multiple files and metadata in a single file . One can combine these in two natural ways compress the individual files, and then archive into a single file archive into a single data block, and then compress. The order matters these operations do not Commutativity commute , and this latter is solid compression. In Unix, compression and archiving are traditionally separate operations, which allows one to understand this distinction compressing individual files and then archiving ... compression. Rationale Benefits Solid compression allows for much better compression rates when ... sometimes even all data after the damaged part can be unusable depending on the compression and archiving ... files can usually still be extracted. References references DEFAULTSORT Solid Compression Category Data compression de Progressive Kompression fr Compression compacte it Compressione solida ru ... more details
Unreferenced date October 2008 Image Compression fitting isolating valve 15mm screwdriver turn.jpg thumb A compression fitting 15 mm isolating valve compression physical Compression Piping and plumbing fittings fitting s are used in plumbing and electrical conduit systems to join two tubing material ... be made of one or more compatible materials appropriate for the connection. Compression fittings for attaching tubing piping commonly have ferrule s or olives in the UK in them. Compression fittings are also used extensively for hot and cold water faucets taps and toilet stop valve s compression fittings ... copper pipe would be difficult to solder without creating a fire hazard. Compression fittings are the industry ... can be remade. How they work The compression fitting is composed of an outer compression nut and an inner compression ring or ferrule that is usually made of brass or copper. Ferrules vary in shape and material ... for use on compression fitting threads, as it is not the thread that seals the joint, but the compression of the ferrule. Sealants may prevent a uniform compression and so weaken the joint. It is important to the integrity of a compression fitting that excessive force be avoided when tightening the nut .... Indeed, over tightening is the most common cause of leaks in compression fittings. A good rule of thumb ..., the fitting is slowly tightened until the weeping stops. The most important component in a compression ... until new parts can be procured. Types of fittings There are two common types of compression fitting ... used to slide the nut and ferrule off the tube. Advantages Compression fittings are popular because ... no special tools or skills to operate. They work at higher pressures and with toxic gases. Compression ... torch, is prohibited. Disadvantages Compression fittings are not as robust as soldered fittings. They should ... and bending such as when pipes knock or shake from sudden pressure changes . Compression fittings are much ... Tips Jointing compression.pdf Jointing Copper Tubes Compression Joints , UK Copper Board Category ... more details
TWCleanup Orphan date February 2009 A compression pump is a machine used to keep blood and lymph flowing by pushing air through bands or sleeves that are placed on the arm s or human leg legs . References reflist External links http www.cancer.gov Templates db alpha.aspx?CdrID 476470 Compression pump entry in the public domain NCI Dictionary of Cancer Terms NCI cancer dict Category Medical pumps med stub ... more details
In telecommunication , the term bandwidth compression has the following meanings The reduction of the Bandwidth computing bandwidth needed to transmit a given amount of data in a given time . The reduction of the time needed to transmit a given amount of data in a given bandwidth. Note Bandwidth compression implies a reduction in normal bandwidth of an information carrying signal information theory signal without reducing the information content of the signal. This can be accomplished with data compression techniques. Source from Federal Standard 1037C and from MIL STD 188 See also Modem Increasing speeds telecomm term stub Category Telecommunications terms ... more details
Gravitational compression is a phenomenon in which gravity , acting on the mass of an object, compresses it, reducing its size and increasing the object s density . File Stellar core.gif thumb In the Solar core core of a star such as the Sun , gravitational pressure is balanced by the outward thermal pressure from Nuclear fusion fusion reactions , temporarily halting gravitational compression. At the center of a planet or star , gravitational compression produces heat by the Kelvin Helmholtz mechanism . This is the mechanism that explains how Jupiter continues to radiation radiate heat produced by its gravitational compression. ref name SRI1 cite web url http www.iki.rssi.ru nineplanets jupiter.html title Jupiter publisher Space Research Institute,Russian Academy of Sciences accessdate 2009 11 05 ref The most common reference to gravitational compression is with respect to stellar evolution . The Sun and other main sequence main sequence stars are produced by the initial gravitational collapse of a giant molecular cloud . Assuming the mass of the material is large enough, gravitational compression reduces the size of the core, increasing its temperature until hydrogen fusion can begin. This hydrogen to helium fusion reaction releases energy which balances the inward gravitational pressure and the star becomes stable for millions of years. No further gravitational compression occurs until the hydrogen is nearly used up, reducing the thermal pressure of the fusion reaction. ref cite web url http www.space.com scienceastronomy astronomy star formation 010116.html title How a Star ... ref At the end of the Sun s life, gravitational compression will turn it into a white dwarf . ref Cite ... compression will produce either a neutron star ref Cite web author M. Coleman Miller title Introduction ... when the compression physical compression due to gravity is balanced by a pressure gradient in the opposite direction due to the strength of the material, at which point gravitational compression ... more details
A compression driver is a type of loudspeaker driver which uses the technique of compression to achieve high efficiencies. In this context compression refers to the fact that the area of the loudspeaker diaphragm is significantly larger than the aperture through which the sound is radiated. Compression Drivers are most commonly used in high sound pressure level applications. They are normally used in conjunction with Horn acoustic acoustical horns . Horn loaded Compression Drivers can achieve extremely high efficiencies compared to direct radiating loudspeakers. The efficiency can even pass 100 ... for much better energy transfer. In the Hanna and Slepian proposal the compression cavity is directly ... ref They devised a plug placed in front of a radiating diaphragm to control the transition from compression ... in compression cavity is reduced. The paper described the first generation compression driver ... ref The first commercial compression driver was introduced 1933 when Bell Labs added a Western Electric No. 555 compression driver as a mid range driver to their the two way divided range loudspeaker ... contribution to modern phase plug, and hence compression driver design, with his paper published ... Smith analyzed the acoustical resonances occurring in the compression cavity and devised a design ... volume preprint 1384 ref . Today the majority of compression drivers, either by inheritance or design ... A New Methodology for the Acoustic Design of Compression Driver Phase Plugs with Concentric Annular ... 7258 ref using a more accurate analytical acoustical model of the compression driver geometry. From ... of acoustical resonance in the compression cavity. Interestingly, in this work Smiths derivation is confirmed using Finite Element Analysis, a luxury that was unavailable to Smith. Compression driver ... the power available to the compression driver. ref http www.audioxpress.com magsdirx voxcoil addenda ... speakers DEFAULTSORT Compression Driver Category Loudspeaker technology ... more details
Compression Systems formerly Cooper Compression Cooper Energy Services Cooper Turbocompressor Cooper , one of three organizational groups within Cameron International Corporation , is a provider of Reciprocating compressor reciprocating and Centrifugal compressor centrifugal Gas compressor compression equipment and aftermarket parts and services. Reciprocating compression equipment is used throughout the energy industry by gas transmission companies, compression leasing companies, oil and gas producers and independent power producers. Integrally geared centrifugal compressors are used by customers around the world in a variety of industries such as air separation, auto making, glass blowing, PET, petrochemical and chemical. History Compression Systems began in 1833 when Charles and Elias Cooper established a foundry in Mount Vernon, Ohio Mt. Vernon , Ohio . Cooper , as it was known, was licensed to produce the Corliss steam engine in 1869 and entered the production of natural gas internal combustion engine s in 1900. In 1929, Cooper merged with Bessemer Gas Engine Company, which was founded in Grove City, Pennsylvania Grove City , Pennsylvania in 1899. In 1958, Cooper diversified into the controls industry with the establishment of the En Tronic Controls Group. Five years later, the company acquired the Ajax Engine Company, founded in 1877, and the Pennsylvania Process, founded to manufacture compressors in 1920. ref name cooper cite book author Keller, David N. title Cooper Industries 1833 1983 edition publisher Ohio University Press year 1983 isbn 0 8214 0751 1 ref In 1965 ... as part of Cooper Compression. One year later, Cooper acquired Enterprise Engine after market ... to form Cooper Compression, which was later named Compression Systems in 2005. ref name history Compression System Brands Reciprocating Compressors Ajax Engines Cooper Bessemer Integral Engines Superior Engines & Compressors Turbine Specialties Engine Turbochargers TSI Compression Specialties CSI ... more details
A disk compression utility software software utility increases the amount of information that can be stored on a hard disk drive of given size. Unlike a file compression utility which compresses only specified ... compression utility works automatically and the user doesn t need to be aware of its existence. When information needs to be stored to the hard disk, the utility will data compression compress the information. When information needs to be read, the utility will decompress the information. A disk compression ... software application s access the hard disk using these routines, they continue to work after disk compression has been installed. Disk compression utilities were popular especially in the early 1990s ... compression applications, the software proved to be in the short term a more economic means of acquiring more disk space as opposed to replacing their current drive with a larger one. A good disk compression utility could, on average, double the available space with negligible speed loss. Disk compression ... to increased capacities and lower prices. Note While the most familiar disk compression utilities ... , for example, worked on the Apple Macintosh platform. Common disk compression utilities Standalone utilities The initial compression utilities were sold independently. A user had to specifically choose ... from Salient Software Bundled utilities The idea of Bundling marketing bundling disk compression ... 6.22 , from Microsoft, included DriveSpace , which was DoubleSpace with a different compression algorithm ... disk compression works Disk compression usually creates a single large file, which becomes a Storage ... of MS DOS IO.SYS and begins Config.Sys processing Compression device driver is loaded. Compressed ... Impacts On systems with slower hard drives, disk compression could actually increase system ... the system significantly. Compression and decompression of the data will increase the CPU utilization. If the system was already CPU bound , disk compression will decrease overall performance. Drawbacks ... more details
In natural language processing , semantic compression is a process of compacting a lexicon used to build a textual document or a set of documents by reducing language heterogeneity, while maintaing text semantics . As a result, the same ideas can be represented using smaller set of words. Semantic compression is a lossy compression , that is some data is being discarded, and an original document cannot be reconstructed in a reverse process. Semantic compression by generalization Semantic compression is basically achieved in two steps, using frequency list frequency dictionaries and semantic network determining cumulated term frequencies to identify target lexicon, replacing less frequent terms with their hypernyms generalization from target lexicon. ref http dx.doi.org 10.1007 978 3 642 12090 9 10 D. Ceglarek, K. Haniewicz, W. Rutkowski, Semantic Compression for Specialised Information Retrieval Systems , Advances in Intelligent Information and Database Systems, vol. 283, p. 111 121, 2010 ref Step 1 requires assembling word frequencies and information on semantic relationships, specifically hyponymy . Moving upwards in word hierarchy, a cumulative concept frequency is calculating by adding ... cumulated frequencies are chosen to build a targed lexicon. In the second step, compression mapping ... compression. Words in bold have been replaced by their hypernyms. blockquote They are both ... they divvy up the work of affirming a biological group . blockquote Implicit semantic compression ... semantic compression, by omitting unmeaningful words or redundant meaningful words especially ... compression of text , COLING 82 Proceedings of the 9th Conference on Computational Linguistics ... complexity and a positive influence on efficiency. Semantic compression is advantageous in information ... compression in classification Proceedings of the 2nd International Conference on Computational ... semantic compression.php Semantic compression on Project SENECA Semantic Networks and Categorization ... more details
Parallel compression , also known as New York compression , is a dynamic range compression technique used in Sound recording and reproduction sound recording and Audio mixing recorded music mixing . Parallel compression, a form of upward compression, is achieved by mixing an unprocessed dry , or lightly ... in 1965, contained parallel buses with heavy compression on one of them, the two mixed in a flexible ... name Izhaki Bevelle called it side chain compression, though that term made for confusion with the Dynamic range compression Side chaining side chain compression technique which uses an external key or side chain signal to determine compression on a target signal. Bevelle s article, entitled Compressors ... PA138 ref Bob Katz coined the term parallel compression , ref name Izhaki and has described it as an implementation of upward compression , the increase in audibility of softer passages. ref name Katz2002 ... up the name New York compression . ref name Izhaki Use The human ear is sensitive to loud sounds being suddenly reduced in volume, but less so to soft sounds being increased in volume parallel compression ... compression, fast Transient acoustics transients in music are retained in parallel compression ... Izhaki In an audio mix using an analog mixing console and analog compressors, parallel compression ... pathways must both have the same number of processing stages the straight pathway is assigned a compression ... through compression stages, and both pathways are delayed the same amount of time, but one is set to do no dynamic range compression, or to do very little, and the other is set for high amounts of gain ... . ref cite journal last Senior first Mike month April year 2009 title Cubase Advanced Vocal Compression ... uses parallel compression applied conservatively across the entire mix, especially in dance oriented ... compression is widely utilized in electronic dance music, side chain compression is the technique ... Parallel Compression in Pro Tools 8 DEFAULTSORT Parallel Compression Category Audio engineering Category ... more details
Fractal compression is a lossy compression method for digital image s, based on fractal s. The method ... to do this efficiently. A simple approach ref cite news last Fischer first Y. title Fractal Image Compression ... based image representations. Features With fractal compression, encoding is extremely computationally ... for distribution from disk storage or file downloads fractal compression becomes more competitive. ref http www.cas.sc.edu geog rslab Rscc mod2 2 4 2 4.html Image Compression Alternatives and Media Storage Considerations Georgia Institute of Technology reference to compression decompression ... At common compression ratios, up to about 50 1, Fractal compression provides similar results to Discrete ... coauthors title Introduction to Data Compression, Third Edition publisher Morgan Kaufmann year 2005 location pages 560 569 url doi id isbn 012620862X ref At high compression ratios fractal compression ... Sensing Symposium paper Achieving high data compression of self similar satellite images using fractal. ref have been achieved with acceptable results. Fractal video compression ratios of 25 1 244 1 have been achieved in reasonable compression times 2.4 to 66 sec frame . ref http cat.inist.fr ?aModele afficheN&cpsidt 1572685 Fractal encoding of video sequences ref Compression efficiency increases ... and fractal scaling An inherent feature of fractal compression is that images become resolution ... on fractal compression resolution independence ref after being converted to fractal code. This is because ... codes via fractal compression, and subsequently decompressed at a higher resolution. The result ... Interpolation decoding method with variable parameters for fractal image compression ... University, Faculty of Engineering ref History Michael Barnsley led development of fractal compression ... fractal compression algorithm was invented by Barnsley and Alan Sloan. Barnsley s graduate student ..., Inc. in 2003 ref in 1987 which was granted over 20 additional patents related to fractal compression ... more details
thumb Compression stockings Compression stockings and socks are specialised hosiery items designed ... and thrombosis . Unlike traditional dress or athletic stockings and socks, compression stockings use stronger elastics to create significant pressure on the legs, ankles and feet. Compression ... blood to return to the heart and less blood to pool in the feet. There are two types of compression stockings Gradient and Anti embolism . br Gradient compression stockings These stockings are designed ... in such a way that the compression level is highest around the ankle and lessens towards the top ... peripheral venous insufficiency , caused by incompetent perforator veins. Low pressure compression ... before using compression stocking br A patient s ABI Ankle Brachial Index must be 1.0 per leg to wear compression stockings, otherwise the stockings may obstruct the patient s arterial flow. The ABI ... measure and calculate a patient s ABI. br It is crucial that compression stockings are properly sized. The compression should gradually reduce from the highest compression at the smallest part of the ankle ... cross sectional profile. br Self prescription is reasonably safe assuming that the compression ... current research reports mixed results of compression socks on athletic performance ref cite paper ... title Lower Leg Compression Sleeves Influence on Running Mechanics and Economy in Highly Trained Distance ... of compression stockings on running performance in men runners journal Journal of strength and conditioning ... embolism compression stockings These stockings are commonly referred to as T.E.D. hose, which is a registered ... drainage of the leg. ref cite journal author Bl ttler W, Zimmet SE title Compression therapy ... pmid 18806201 ref br Like gradient compression stockings, anti embolism stockings deliver a distributed amount of compression at the ankle and up the leg. This compression, when combined ... in non ambulatory patients . Compression wear has also been adopted by the sports science industry ... more details
JPEG compression A compression artifact or artefact is a noticeable distortion of media including images , Sound recording audio , and video caused by the application of lossy data compression . Lossy data compression involves discarding some of the media s data so that it becomes simplified enough ..., the compression algorithm may not be intelligent enough to discriminate between distortions of little subjective importance and those which may be objectionable to the viewer. Compression artifacts ... compression losslessly compressed media such as FLAC or Portable Network Graphics PNG do not suffer from compression artifacts. The minimization of perceivable artifacts is a key goal in implementing a lossy compression algorithm. However, artifacts are occasionally intentionally produced for artistic ... date 2011 07 29 accessdate 2011 12 23 ref Technically speaking, a compression artifact is a particular ... in lossy data compression. Where transform coding is used, they typically assume the form of one ... of the effect of JPEG compression on a slightly noisy image with a mixture of text and whitespace ... have been proposed to reduce the effects of image compression, but in order to utilize standardized compression decompression techniques and to retain the benefits of the compression for instance ... prediction is used, as in MPEG 1 , MPEG 2 or MPEG 4 , compression artifacts tend to remain on several ... swarming mosquitoes. Video compression artifacts include cumulative results of compression of the comprising ... Patry. http www.videsignline.com howto 180207350 Video compression artifacts and MPEG noise ... 96 Principles of a reference impairment system for video ref Audio Lossy audio compression typically ... tone. A lossy compression technique might identify this quiet tone and attempt to remove it. Also, quantization noise can be hidden where they would be masked by more prominent sounds. With low compression ..., when the transform block size is restrained, or when aggressive compression is used, this may ... more details
Unreferenced date December 2009 In computational complexity theory the compression theorem is an important theorem about the complexity of computable function s. The theorem states that there exists no largest complexity class , with computable boundary, which contains all computable function s. Compression theorem Given a G del numbering math varphi math of the computable functions and a Blum complexity measure math Phi math where a complexity class for a boundary function math f math is defined as math mathrm C f varphi i in mathbf R 1 forall infty x , Phi i x leq f x . math Then there exists a total computable function math f math so that for all math i math math mathrm Dom varphi i mathrm Dom varphi f i math and math mathrm C varphi i subsetneq mathrm C varphi f i . math DEFAULTSORT Compression Theorem Category Computational complexity theory Category Structural complexity theory Category Theorems in the foundations of mathematics ... more details
Ischemic compression is a therapy technique used in physical therapy , where Ischemia blockage of blood in an area of the body is deliberately made, so that a resurgence of local blood flow will occur upon release. ref Montanez Aguilera FJ Valtuena Gimeno N Pecos Martin D Arnau Masanet R Barrios Pitarque C Bosch Morell F 2010 . Changes in a patient with neck pain after application of ischemic compression as a trigger point therapy. Journal of Back & Musculoskeletal Rehabilitation, 23 2 , 101 104. doi 10.3233 BMR 2010 0255 ref Ischemic compression is commonly applied to trigger point s, in what is known as trigger point therapy , where enough sustained pressure is applied to a trigger point with a tolerable amount of pain, and as discomfort is reduced, additional pressure is gradually given. References reflist See also Myofascial release alt med stub Category Physical therapy Category Alternative medicine ... more details
unreferenced date March 2010 Unreferenced stub auto yes date December 2009 Infobox Album See Wikipedia WikiProject Albums Name Natural Compression Type EP Artist Weta band Weta Cover Natural Compression.png Released 8 August 1999 Recorded Sing Sing Studios Genre Rock Label Warner Music Producer Steve James Reviews This album Natural Compression br 1999 Next album Geographica album Geographica br 2000 Natural Compression was the first release by defunct New Zealand rock band Weta band Weta , being released in 1999. The EP received radio attention in New Zealand with the title track Let It Go Weta song Let It Go becoming a staple of student and rock radio. Both Let It Go Weta song Let It Go and Got The Ju would appear on the bands sole album Geographica album Geographica in revised forms. Track listing Let It Go Weta song Let It Go Got the Ju Where Have You Been? Updown DEFAULTSORT Natural Compression EP Category 1999 EPs Category Weta albums 1990s rock album stub ... more details
Infobox disease Name Compression fracture Image L4 compressionFracture2008.jpg Caption Compression fracture of the fourth lumbar vertebra post falling from a height. ICD10 ICD9 ICD9 733.13 or 805x and 806x,if traumatic Image Compressionfracture.jpg thumb X ray of the lumbar spine with a compression fracture of the third lumbar vertebra. A compression fracture is a collapse of a vertebra . It may be due to trauma or due to a weakening of the vertebra. This weakening is seen in patients with osteoporosis or osteogenesis imperfecta , lytic lesions from metastatic or primary tumors, ref http www.hopkins arthritis.org physician corner cme rheumatology rounds metastatic bone disease rheumrounds2.html Rounds 2 Treatment of Metastic Bone Disease. A CME approved training from Johns Hopkins Arthritis Center. ref or infection ref http www.nlm.nih.gov medlineplus boneinfections.html NIH summary of osteomyelitis for patients ref . In healthy patients it is most often seen in individuals suffering extreme vertical shocks, such as ejecting from an ejection seat . Seen in lateral views in plain x ray films, compression fractures of the spine characteristically appear as wedge deformities , with greater loss of height anteriorly than posteriorly and intact pedicle of vertebral arch pedicles in the anteroposterior view. ref cite journal author Brant W, Helms C title Fundamentals of Diagnostic Radiology journal volume issue Third Edition pages 302 year pmid doi ref Treatment Conservative treatment ... BH title Calcitonin for treating acute pain of osteoporotic vertebral compression fractures a systematic ... RJ, Fritzell P title Balloon kyphoplasty and vertebroplasty for vertebral compression fractures a comparative ... in the management of vertebral compression fractures an updated systematic review and meta ... compression fractures and sometimes other forms of fracture, such as a fracture caused by certain ... vertebral compression fracture article em.htm Vertebral Compression Fracture information on eMedicineHealth ... more details
Image FossilFernLeavesPennsylvanianOhio.jpg thumb Fossil seed fern leaves from the Late Carboniferous of northeastern Ohio . A compression fossil is a fossil preserved in sedimentary rock that has undergone compression physical physical compression . While it is uncommon to find animal s preserved as good compression fossils, it is very common to find plant s preserved this way. The reason for this is that physical compression of the rock often leads to distortion of the fossil. The best fossils of leaf leaves are found preserved in fine layers of sediment that have been compressed in a direction perpendicular to the plane of the deposited sediment. ref name Arnold 1947 Since leaves are basically flat, the resulting distortion is minimal. Plant stem s and other three dimensional plant structures do not preserve as well under compression. Typically, only the basic outline and surface features are preserved in compression fossils internal anatomy is not preserved. These fossils may be studied while still partially entombed in the sedimentary rock matrix where they are preserved, or once lifted out of the matrix by a peel or transfer technique. ref name Stewart 1993 Compression fossils are formed most commonly in ecosystem environment s where fine sediment is deposited, such as in river delta s, lagoon s, along river s, and in pond s. The best rocks in which to find these fossils preserved are clay and shale , although volcanic ash may sometimes preserve plant fossils as well. ref name Taylor & Taylor 1993 References Reflist 2 refs ref name Arnold 1947 cite book last Arnold first Chester A. year 1947 title An Introduction to Paleobotany edition 1st location New York & London publisher McGraw Hill Book Company pages 14 40 ref ref name Stewart 1993 cite book last1 Stewart first1 Wilson N. last2 Rothwell first2 Gar W. year 1993 title Paleobotany and the Evolution of Plants edition 2nd location Cambridge publisher Cambridge University Press isbn 0 521 38294 7 pages 7 22 re ... more details
Compression virus is an example of a benevolent Computer virus invented by Fred Cohen . It searches for an uninfected executable file, compresses the file and prepends itself to it. The virus can be described in pseudo code ref http all.net books virus index.html 1984, Computer Viruses Theory and Experiments ref pre program compression virus 01234567 subroutine infect executable loop file get random executable file if first line of file 01234567 then goto loop compress file prepend compression virus to file main program if ask permission then infect executable uncompress the rest of this file into tmpfile run tmpfile pre The 01234567 is the Computer Virus Self modification virus signature , and is used to make sure if first line of file 01234567 the file is not already infected. The virus then asks for permission ask permission to infect a random executable get random executable file . If permission granted, it Data compression compresses the executable infect executable , prepends itself to it prepend , uncompresses the current executable file uncompress the rest of this file into a temporary file tmpfile and runs it run tmpfile . Cruncher is an example of a compression virus ref Mark A. Ludwig 1995, Giant Black Book of Computer Viruses p.10 ref , a strain of which Cruncher.2092 ref http vil.nai.com vil content v 318.htm McAfee article on Cruncher.2092, read Characteristics ref is described by McAfee as Terminate and Stay Resident memory resident virus that infects all but small COM file com files, making them smaller. The reason for excluding small programs is that their infected versions will be bigger than their originals. References references Category Computer viruses ... more details
The Quantum compression format is a little known data compression method created by David Stafford of Cinematronics, LLC . It was licensed to Borland , Microsoft and Novell ref cite web last Stafford first David title About David Stafford url https plus.google.com 106801081939432843780 about work Google publisher Google inc accessdate 12 December 2011 ref . Quantum is one of the possible compression methods in a Microsoft Windows Cabinet file format CAB archive ref http www.cabextract.org.uk History of CAB files format ref . Quantum uses an extended Abraham Lempel LZ compression algorithm. Quantum archive files are named with the filename extension .Q by convention. Quantum archiver PAQ.EXE is the Quantum compressor for MS DOS and UNPAQ.EXE is the decompressor. These are 32 bit applications using a DOS extender from Borland. There is no Quantum compressor for Microsoft Windows. QWIN.EXE is the Quantum decompressor for 16 bit Windows. It is much faster than the MS DOS decompressor and has more features such as selective decompression. All the Quantum compressors and decompressors require at least a Intel 80386 386 Central Processing Unit CPU in order to run. The last known version is 0.97 . Quantum archive file structure File header class wikitable Bytes Description 2 Quantum signature 0x44 0x53 1 Quantum major version number 1 Quantum minor version number 2 number of files within this archive 1 table size required for decompression 1 compression flags This is immediately followed by the list of files class wikitable Bytes Description variable length of file name, see below variable file name, variable length string, not zero terminated variable length of comment field, see below variable comment field, variable length string, not zero terminated 4 fully expanded file size ... reflist cite book last Salomon first David title Data compression the complete reference publisher ... quantumcomp.html ftp ftp.sac.sk pub sac pack quant097.zip Category Data compression software computer ... more details
Image Rubber boots.jpg thumb right Compression molded rubber boots before the Flash manufacturing flashes are removed. Compression molding is a method of molding process molding in which the molding material, generally preheated, is first placed in an open, heated mold cavity. The mold is closed with a top force or plug member, pressure is applied to force the material into contact with all mold areas, while heat and pressure are maintained until the molding material has cured. The process employs ..., or preforms. Compression molding is a high volume, high pressure method suitable for molding complex, high strength fiberglass reinforcements. Advanced composite thermoplastic s can also be compression .... The advantage of compression molding is its ability to mold large, fairly intricate parts. Also, it is one ... with expensive compounds. However, compression molding often provides poor product consistency and difficulty ... to injection molding. Compression molding is also suitable for ultra large basic shape production ... through compression molding include Polyester fiberglass resin systems SMC BMC , Torlon , Vespel , Poly p phenylene sulfide PPS , and many grades of PEEK . Compression molding was first developed to manufacture composite parts for metal replacement applications, compression molding is typically used ... during the compression stage. Thermoplastic matrices are commonplace in mass production industries ... LFT and Glass fiber Mat reinforced Thermoplastics GMT . In compression molding there are six important ... Compression molding is a forming process in which a plastic material is placed directly into a heated ... cycle moulding times are widely used and examples are shown in Ref 3. Process schematic The compression ... in Ref 3. Setup and equipment Compression mold presses are manufactured in a wide variety of sizes ... on page 219 220. Further reading Compression Molding, ASM Handbook 2001, volume 21 Composites, Peterson ... http www.ticona.com home tech processing compression molding.htm Category Plastics industry de Formpressen ... more details
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