Encyclopedia of Computer Science and Technology

356 optical computingA more generalized method uses structural features(such as “all t’s have a single vertical line and a shortercrossbar line”) to classify characters. To analyze a character,the different types of individual features are identified andthen compared to a set of rules to determine the charactercorresponding to that particular combination of features.Sometimes thresholds or “fuzzy logic” are used to decidethe probable identity of a character.OCR systems have improved considerably, the processalso being speeded up by today’s faster processors. Mostscanners are sold with OCR software that is perhaps 95percent accurate, with higher end systems being more accuratestill. This is certainly good enough for many purposes,although material that is to be published or used in legaldocuments should still be proofread by human beings.Further ReadingMore, Shunji, Hirobumi Nishida, and Hiromitsu Yamada, eds.Optical Character Recognition. New York: Wiley, 1999.Rice, S. V., G. Nagy and T. A. Nartker. Optical Character Recognition:An Illustrated Guide to the Frontier. Boston: Kluwer,1999.optical computingLight is the fastest thing in the universe, and the scienceand technology of optics have developed greatly since theinvention of the laser in the 1960s. It is not surprising,therefore, that computer designers have explored the possibilityof using optics rather than electronics for computationand data storage.An early idea was to use a grid of laser beams to createlogical circuits, exploiting the ability of one laser to be usedto “quench” or switch off another one. However, creating alarge number of tiny laser beams proved impracticable, asdid managing the heat created by the process. However, bythe 1980s, experimenters were interacting “microlasers” withsemiconductors, exploiting quantum effects. This broughtthe energy (and heat) problem under control while vastlyincreasing the potential density of the optical circuitry.The incredible rate at which conventional silicon-basedelectronic circuitry continued to increase in density andcapacity has limited the incentive to invest in the largescaleresearch and development that would be needed todevelop a complete optical computer with processor and acorresponding optical memory technology.Instead, current research is exploring the possibility ofcombining the best features of the optical and electronicsystem. Silicon chips have a limited surface for connectingdata inputs, while light can carry many more channels ofdata through micro-optics. It may be possible to couple amicro-optic array to the surface of the silicon chip in sucha way that the chip could have the equivalent of thousandsof connecting pins to transmit data. In March 2007 IBMunveiled a prototype hybrid chip that combines optical andsemiconductor technology to achieve eight times the datatransfer rate of conventional technologies.The value of optics is more conclusively demonstratedin data transmission and storage technology. Fiber opticcables are being used in many cases to carry large quantitiesof data with very high capacity (see fiber optics) andmay gradually supplant conventional network cable in moreapplications. The use of lasers to store and read informationis seen in CD-ROM and DVD-ROM technology, whichhas replaced the floppy disk as the ubiquitous carrier ofsoftware and handy backup medium (see cd-Rom andDVD-ROM).Further ReadingGoswami, Debabrata. “Optical Computing.” Resonance, June2003. Available online. URL: http://www.ias.ac.in/resonance/June2003/pdf/June2003p56-71.pdf. Accessed August 16, 2007.Knight, Will. “Laser Chips Could Power Petaflop Computers.”New Scientist.com. March 21, 2006. Available online. URL:http://www.newscientist.com/article.ns?id=dn8876. AccessedAugust 16, 2007.“Now, Just a Blinkin’ Picosecond!: NASA Scientists Are Workingto Solve the Need for Computer Speed Using Light Itself toAccelerate Calculations and Increase Data Bandwidth.” Science& NASA. Available online. URL: http://science.nasa.gov/headlines/y2000/ast28apr_1m.htm. Accessed August 16,2007.Saleh, Bahaa E. A., and Malvin Carl Teich. Fundamentals of Photonics.2nd ed. New York: Wiley Interscience, 2007.Oracle CorporationFounded in 1977, Oracle Corporation (NASDAQ symbol:ORCL) is a leading developer of business database software(see database management system) as well as systemsfor other enterprise operations (see customer relationshipmanagement and supply chain management). Thesefunctions are integrated through a structure called OracleInformation Architecture that can coordinate the operationsof servers and storage systems (see grid computing).Besides selling software, a major part of Oracle’s businessis providing consulting and support for fitting the softwareto the needs of corporate customers, as well as training(through Oracle University) and distributed application services(Oracle on Demand). In 2007 Oracle had $18 billionin sales, netting $4.74 billion in profit. The company hadover 73,000 employees.Since its founding, Oracle’s CEO has been the dynamicthough often controversial Larry Ellison, who recognizedthe importance of relational databases (with their ability toconnect information from many sources) as a way to meetthe growing information needs of modern business. In the1970s IBM was the dominant leader in relational databasesfor mainframe computers, but when personal computersrunning Windows became prevalent around 1990, IBM wasslow to enter the new market. Ellison and competitors suchas Sybase and Informix were able to carve out strong niches,with Oracle coming out on top by the end of the decade.(However, by the 2000s IBM’s DB2 for UNIX/Linux andWindows and Microsoft SQL Server [for Windows only]were strong competitors, with open-source products MySQLand PostgreSQL also gaining attention—see SQL.)In recent years Oracle has also expanded through acquisition,picking up other software companies, including PeopleSoft;Retek, Inc.; and Siebel Systems, for a combined totalof over $16 billion. In 2007 Oracle filed a lawsuit against its