OASIS
OASIS (Organization for Structured Information Standards) is a nonprofit, international consortium whose goal is to promote the adoption of product-independent standards for information formats such as Standard Generalized Markup Language (SGML), Extensible Markup Language (XML), and Hypertext Markup Language (HTML). Currently, OASIS (formerly known as SGML Open) is working to bring together competitors and industry standards groups with conflicting perspectives to discuss using XML as a common Web language that can be shared across applications and platforms.
OASIS sponsors XML.org, a non-profit XML Web portal. The goal of OASIS is not to create structured information standards for XML, but to provide a forum for discussion, to promote the adoption of interoperability standards, and to recommend ways members can provide better interoperability for their users. OASIS has worked with the United Nations to sponsor ebXML, a global initiative for electronic business data exchange. EbXML, whose goal is to make it easier for companies of all sizes and locations to conduct business on the Internet, is currently focusing on the specific needs of business-to-business (B2B) and Internet security as it relates to XML.
object
In object-oriented programming (OOP), objects are the things you think about first in designing a program and they are also the units of code that are eventually derived from the process. In between, each object is made into a generic class of object and even more generic classes are defined so that objects can share models and reuse the class definitions in their code. Each object is an instance of a particular class or subclass with the class’s own methods or procedures and data variables. An object is what actually runs in the computer.
object code
Source code and object code refer to the ”before” and ”after” versions of a computer program that is compiled (see compiler) before it is ready to run in a computer. The source code consists of the programming statements that are created by a programmer with a text editor or a visual programming tool and then saved in a file. For example, a programmer using the C language types in a desired sequence of C language statements using a text editor and then saves them as a named file. This file is said to contain the source code. It is now ready to be compiled with a C compiler and the resulting output, the compiled file, is often referred to as object code. The object code file contains a sequence of instructions that the processor can understand but that is difficult for a human to read or modify. For this reason and because even debugged programs often need some later enhancement, the source code is the most permanent form of the program.
When you purchase or receive operating system or application software, it is usually in the form of compiled object code and the source code is not included. Proprietary software vendors usually don’t want you to try to improve their code since this may create additional service costs for them. Lately, there is a movement to develop software (Linux is an example) that is open to further improvement by anyone who wants to improve it, and here the source code is provided.
In large program development environments, there are often management systems that help programmers separate and keep track of different states and levels of code files. For script (noncompiled or interpreted) program languages, such as JavaScript, the terms source code and object code do not apply since there is only one form of the code.
Object Management Group
The OMG (Object Management Group) was formed in 1989 by a group of vendors for the purpose of creating a standard architecture for distributed objects (also known as ”components”) in networks. The architecture that resulted is the Common Object Request Broker Architecture (CORBA). A central element in CORBA is the Object Request Broker (ORB). An ORB makes it possible for a client object to make a server request without having to know where in a network the server object or component is located and exactly what its interfaces are.
A number of middleware products have begun to use CORBA and it appears to be the strategic architecture for distributed objects. The OMG now boasts of over 500 member companies.
Object Request Broker
Also see ORBS, a term easily confused with ORB.
In Common Object Request Broker Architecture (CORBA), an Object Request Broker (ORB) is the programming that acts as a ”broker” between a client request for a service from a distributed object or component and the completion of that request. Having ORB support in a network means that a client program can request a service without having to understand where the server is in a distributed network or exactly what the interface to the server program looks like. Components can find out about each other and exchange interface information as they are running.
CORBA’s ORB may be thought of as strategic middleware that is more sophisticated conceptually and in its capabilities than earlier middleware, including Remote Procedure Calls (RPCs), message-oriented middleware, database stored procedures, and peer-to-peer services.
An ORB uses the CORBA Interface Repository to find out how to locate and communicate with a requested component. When creating a component, a programmer uses either CORBA’s Interface Definition Language (IDL) to declare its public interfaces or the compiler of the programming language translates the language statements into appropriate IDL statements. These statements are stored in the Interface Repository as metadata or definitions of how a component’s interface works.
In brokering a client request, an ORB may provide all of these services:
• Life cycle services, which define how to create, copy, move, and delete a component.
• Persistence service, which provide the ability to store data on object database, and plain files.
• Naming service, which allows a component to find another component by name and also supports existing naming systems or directories, including DCE, and Sun’s NIS (Network Information System).
• Event service, which lets components specify events that they want to be notified of.
• Concurrency control service, which allows an ORB to manage locks to data that transactions or threads may compete for.
• Transaction service, which ensures that when a transaction is completed, changes are committed, or that, if not, database changes are restored to their pre-transaction state.
• Relationship service, which creates dynamic associations between components that haven’t "met" before and for keeping track of these associations.
• Externalization service, which provides a way to get data to and from a component in a "stream."
• Query service, which allows a component to query a database. This service is based on the SQL3 specification and the Object Database Management Group’s (ODMG) Object Query Language (OQL).
• Licensing service, which allows the use of a component to be measured for purposes of compensation for use. Charging can be done by session, by node, by instance creation, and by site.
• Properties service, which lets a component contain a self-description that other components can use.
In addition, an ORB also can provide security and time services. Additional services for trading, collections, and change management are also planned. The requests and replies that originate in ORBs are expressed through the Internet Inter-ORB Protocol (IIOP) or other transport layer protocols.
object-oriented database management system
An object-oriented database management system (OODBMS), sometimes shortened to ODBMS for object database management system), is a database management system (DBMS) that supports the modelling and creation of data as objects. This includes some kind of support for classes of objects and the inheritance of class properties and methods by subclasses and their objects. There is currently no widely agreed-upon standard for what constitutes an OODBMS, and OODBMS products are considered to be still in their infancy. In the meantime, the object-relational database management system (ORDBMS), the idea that object-oriented database concepts can be superimposed on relational databases, is more commonly encountered in available products. An object-oriented database interface standard is being developed by an industry group, the Object Data Management Group (ODMG). The Object Management Group (OMG) has already standardized an object-oriented data brokering interface between systems in a network.
In their influential paper, The Object-Oriented Database Manifesto, Malcolm Atkinson and others define an OODBMS as follows:
An object-oriented database system must satisfy two criteria: it should be a DBMS, and it should be an object-oriented system, i.e., to the extent possible, it should be consistent with the current crop of object-oriented programming languages. The first criterion translates into five features: persistence, secondary storage management, concurrency, recovery and an ad hoc query facility. The second one translates into eight features: complex objects, object identity, encapsulation, types or classes, inheritance, overriding combined with late binding, extensibility and computational completeness. Their paper describes each of these features in detail.
object-oriented programming
A revolutionary concept that changed the rules in computer program development, object-oriented programming (OOP) is organized around "objects" rather than "actions," data rather than logic. Historically, a program has been viewed as a logical procedure that takes input data, processes it, and produces output data. The programming challenge was seen as how to write the logic, not how to define the data. Object-oriented programming takes the view that what we really care about are the objects we want to manipulate rather than the logic required to manipulate them. Examples of objects range from human beings (described by name, address, and so forth) to buildings and floors (whose properties can be described and managed) down to the little widgets on your computer desktop (such as buttons and scroll bars).
The first step in OOP is to identify all the objects you want to manipulate and how they relate to each other, an exercise often known as data modeling. Once you’ve identified an object, you generalize it as a class of objects (think of Plato’s concept of the "ideal" chair that stands for all chairs) and define the kind of data it contains and any logic sequences that can manipulate it. Each distinct logic sequence is known as a method. A real instance of a class is called (no surprise here) an "object" or, in some environments, an "instance of a class." The object or class instance is what you run in the computer. Its methods provide computer instructions and the class object characteristics provide relevant data. You communicate with objects—and they communicate with each other—with well-defined interfaces called messages.
The concepts and rules used in object-oriented programming provide these important benefits:
• The concept of a data class makes it possible to define subclasses of data objects that share some or all of the main class characteristics. Called inheritance, this property of OOP forces a more thorough data analysis, reduces development time, and ensures more accurate coding.
• Since a class defines only the data it needs to be concerned with, when an instance of that class (an object) is run, the code will not be able to accidentally access other program data. This characteristic of data hiding provides greater system security and avoids unintended data corruption.
• The definition of a class is reuseable not only by the program for which it is initially created but also by other object-oriented programs (and, for this reason, can be more easily distributed for use in networks).
• The concept of data classes allows a programmer to create any new data type that is not already defined in the language itself.
One of the first object-oriented computer languages was called Smalltalk. C++ and Java are the most popular object-oriented languages today. The Java programming language is designed especially for use in distributed applications on corporate networks and the Internet.
OC-768
OC-768 is currently the fastest synchronous optical network (SONET) standard rate for data transmission on optical fiber as part of the broadband ISDN (BISDN). OC stands for optical carrier and the number affixed is the multiple of the base rate bandwidth of 51.85 Mbps. OC-768 supports rates of 40 gigabits per second (Gbps) on a fiber optic carrier, a rate that translates to the equivalent of seven CD-ROM’s worth of data in one second. Developed to meet evergrowing demands for bandwidth, OC-768 uses dense wavelength division multiplexing (DWDM) to carry multiple channels of data on a single optic fiber. New DWDM systems are now in development to run at at 10 trillion bits per second (10 Tbps) per fiber. This translates into the theoretical capability of one fiber to support, simultaneously, an active Internet connection to every household in the U.S.
Enkido was the first company to offer OC-768 service, which they currently provide for a number of clients including Deutsche Telecom.
Ockham’s razor
Ockham’s razor (also spelled Occam’s razor, pronounced AHK-uhmz RAY-zuhr) is the idea that, in trying to understand something, getting unnecessary information out of the way is the fastest way to the truth or to the best explanation. William of Ockham (1285-1349), English theologian and philosopher, spent his life developing a philosophy that reconciled religious belief with demonstratable, generally experienced truth, mainly by separating the two. Where earlier philosophers attempted to justify God’s existence with rational proof, Ockham declared religious belief to be incapable of such proof and a matter of faith. He rejected the notions preserved from Classical times of the independent existence of qualities such as truth, hardness, and durability and said these ideas had value only as descriptions of particular objects and were really characteristics of human cognition. Ockham was noted for his insistence on paying close attention to language as a tool for thinking and on observation as a tool for testing reality. His thinking and writing is considered to have laid the groundwork for modern scientific inquiry. Ockham’s insistence on the use of parsimony (we might call it minimalism) in thought resulted in some later writer’s invention of the term, Ockham’s razor. Among his statements (translated from his Latin) are: ”Plurality is not to be assumed without necessity” and ”What can be done with fewer [assumptions] is done in vain with more.” One consequence of this methodology is the idea that the simplest or most obvious explanation of several competing ones is the one that should be preferred until it is proven wrong.
OCR
OCR (optical character recognition) is the recognition of printed or written text characters by a computer. This involves photoscanning of the text character-by-character, analysis of the scanned-in image, and then translation of the character image into character codes, such as ASCII, commonly used in data processing.
In OCR processing, the scanned-in image or bitmap is analyzed for light and dark areas in order to identify each alphabetic letter or numeric digit. When a character is recognized, it is converted into an ASCII code. Special circuit boards and computer chips designed expressly for OCR are used to speed up the recognition process. OCR is being used by libraries to digitize and preserve their holdings. OCR is also used to process checks and credit card slips and sort the mail. Billions of magazines and letters are sorted every day by OCR machines, considerably speeding up mail delivery.
octal
Octal (pronounced AHK-tuhl, from Latin octo or ”eight”) is a term that describes a base-8 number system. An octal number system consists of eight single-digit numbers: 0,1, 2, 3,4,5, 6, and 7. The number after 7 is 10. The number after 17 is 20 and so forth.
In computer programming, the octal equivalent of a binary number is sometimes used to represent it because it is shorter.
octet
In computers, an octet (from the Latin octo or ”eight”) is a sequence of eight bits. An octet is thus an eight-bit byte. Since a byte is not eight bits in all computer systems, octet provides a nonambiguous term.
This term should not be confused with octal, a term that describes a base-8 number system.
OCX
An OCX is an Object Linking and Embedding (OLE) custom control, a special-purpose program that can be created for use by applications running on Microsoft’s Windows systems. OCXs provide such functions as handling scroll bar movement and window resizing. If you have a Windows system, you’ll find a number of files in your Windows directory with the OCX file name suffix.
Object Linking and Embedding was designed to support compound documents (which contain multiple information types, such as text, graphic images, sound, motion video). The Windows desktop is an example of a compound document and Microsoft used OLE to build it. OLE and the Component Object Model (COM), a more general concept that succeeded OLE, support the development of ”plug-and-play” programs that can be written in any language and used dynamically by any application in the system. These programs are known as components and the application in which they are run is known as a container. This component-based approach to application development reduces development time and improves the program capability and quality. Windows application development programs such as PowerBuilder and Microsoft Access take advantage of OCXs.
Microsoft now calls an OCX an ActiveX control, the component object under Microsoft’s set of ActiveX technologies, of which the fundamental concept is the Component Object Model (COM) and, in a network, the Distributed Component Object Model (DCOM).
An OCX or ActiveX control is actually implemented as a dynamic link library DLL module. (You can think of a DLL program as a ”subprogram” that can be used by any number of application programs, each of which is a ”container” for the DLL or OCX/ActiveX control ”object.”) Visual Basic and C++ are commonly used to write OCX or ActiveX controls.
ODL
1) Open and Distance Learning (ODL) is a general term for the use of telecommunication to provide or enhance learning. Around the world, the academic community is discovering and exploring the Internet, teleconferencing, and related means to achieve an extended classroom or learning experience. Students in Russia are earning degrees from a university in Australia. Primary and secondary-grade students are exchanging e-mail across continents as a supplement to their formal studies. Students and teachers at all levels are taking part in teleconferences and forming associations that would have been unlikely five years ago. A number of world conferences have been held on ODL and many experimental projects are underway.
The United States Distance Learning Association has its own formal definition of ”distance learning”:
The acquisition of knowledge and skills through mediated information and instruction, encompassing all technologies and other forms of learning at a distance.
A few of the many educational organizations involved with ODL include:
• The University of Bergen in Bergen, Norway, which offers its own ODL Resource Page
• The Open University at the Institute for Educational Technology in the United Kingdom
• The Virtual Classroom at the New Jersey Institute of Technology
2) Object Description Language (ODL) is a simple language for defining data structures that is used in the United States by the National Aeronautics and Space Adinistration (NASA).
Several somewhat similar languages have been created by other organizations for defining program or data objects. These include an Object Design Language and an Object Definition Language.
ODMA
ODMA (Open Document Management API or Application Program Interface) is an industry standard interface for managing documents that allows users to store, retrieve, and share them with security and version control. For example, you can collaborate with someone in another city on a book in which each of you write separate topics and occasionally work on the same topic . Using a document management system (DMS), you can create a topic using your favorite word processor and store it in the document management system in the ”first draft library.” Later, you can retrieve it from the ”first draft library,” edit it, and put it back. Your collaborator can also retrieve your topic to either look at it or make further changes to it, depending on how you wish to work together. The document management system manages who has read-only or update access to the topic, who has it ”checked out,” and what draft level of the book it is stored in. The Open Document Management API provides vendors of DMS products and products such as word processors with a consistent interface. A word processor can integrate DMS support so that you can create, edit, and manage your documents through the word processor.
DMS is also sometimes called EDMS (Electronic Document Management System).
offline
Offline is the condition of being currently disconnected from a computer or a telecommunications system. The term is frequently used to describe someone who has the ability to be connected to the Internet but who is not currently connected to it.
Deprecated spellings are off-line and off line. The opposite term is online.
Ohm
The ohm is the standard unit of electrical resistance in the International System of Units (SI). Ohms are also used, when multiplied by imaginary numbers, to denote reactance in alternating-current (AC) and radio-frequency (RF) applications. Reduced to base SI units, one ohm is the equivalent of one kilogram meter squared per second cubed per ampere squared (1 kg times m2 • s-3 • A-2). The ohm is also the equivalent of a volt per ampere (V/A).
In a direct-current (DC) circuit, a component has a resistance of one ohm when a potential difference of one volt produces a current of one ampere through the component. In AC and RF circuits, resistive ohms behave the same as they do in DC circuits, provided the root-mean-square (rms) AC voltage is specified. In AC and RF circuits, reactance exists only when there is a net capacitance or inductance. Capacitive reactances have negative imaginary ohmic values; inductive reactances have positive imaginary ohmic values. The reactance of a particular capacitor or inductor depends on the frequency.
Resistances and reactances are sometimes expressed in units representing power-of-10 multiples of one ohm. A kilohm is equal to one thousand (103) ohms. A megohm is equal to one million (106) ohms. Fractional prefix multipliers are seldom used for resistance or reactances; rarely will you hear or read about a milliohm or a microhm. Extremely small resistances and reactances are usually referred to in terms of conductance.
Also see conductance, Ohm’s Law, prefix multipliers, resistance, reactance, siemens, and International System of Units (SI).
