O

O is for Object

OAG (Open Applications Group): The Open Applications Group is a non-profit consortium focusing on best practices and processes based on XML content for eBusiness and Application Integration. The OAG comprises many of the most prominent stakeholders in the business software interoperability industry throughout the world. It was formed in February of 1995 as a nonprofit consortium of leading enterprise application software developers, making it one of the earliest post-EDI organizations. Since that time, the organization has embraced customers, systems integrators, and integration enabling software vendors to work with the application software vendors to ensure that all of the stakeholders that are required to achieve it's goals are welcome and part of the solution. They build industry consensus for business software application interoperability and have developed a repeatable process for quickly developing high quality business content and XML representations of that content.

OASIS (Open Access Same-Time Information System): a system mandated by FERC for the use of Market Participants to buy and sell power system transmission products, such as Available Transmission Capacity (ATC). Transmission Customers can access it via the Internet.

OASIS (Organization for the Advancement of Structured Information Standards), is a non-profit, 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. Web site.

Object: An object is a "black box" which receives and sends messages. The black box contains code (sequences of computer instructions) and data (information which the instructions operates on). A primary rule of object-oriented programming is as the user of an object, one should never need to peek inside the box. Instead all communication to an object is done via messages. This concept is referred to as information hiding or encapsulation. An object is defined via its class, which determines everything about an object. Objects are individual instances of a class.

Object Model: An object model is a specialized grouping of associated "black boxes", which models actual field devices, functions, or applications. It is usually used interchangeably with the phrase Data Model or, for utilities, Device Model. An object model is a model of a device function or application that receives control commands, setting changes, and indication data from other objects.  The object model maintains relevant data, such as configuration parameters, settings, and indication data.  It also outputs control commands and indication data. Object models are the result of the process of data modeling.

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).  

OC (Optical Carrier): A SONET rate of n times 51.84 Mbps.

OC-12: SONET rate of 622.080 Mbps.

OC-192: SONET rate of 9953.280 Mbps.

OC-3: SONET rate of 155.520 Mbps.

OC-48: SONET rate of 2488.320 Mbps.

Octet: In packet-switched networks, a grouping of 8 bits. 

ODBC (Open DataBase Connectivity): is an application programming interface (API) for database access. It is based on the Call-Level Interface (CLI) specifications from X/Open and ISO/IEC for database APIs and uses SQL as its database access language. Microsoft developed standard.

ODP (Open Distributed Processing): The Reference Model for Open Distributed Processing (RM-ODP) was standardized by the ISO/IEC in the 1995/1996 timeframe. International Standard ISO/IEC 10746-1 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 33, Distributed application services, in collaboration with ITU-T. The identical text is published as ITU-T Recommendation X.901. The objective of ODP standardization is the development of standards that allow the benefits of distribution of information processing services to be realized in an environment of heterogeneous IT resources and multiple organizational domains. This comprises the provision of infrastructure components and functions that accommodate difficulties inherent in the design and programming of distributed systems.

Off-line: Not connected to a network such as the corporate LAN or the Internet.

OLE (Object Linking and Embedding): A set of APIs to create and display a (compound) document. OLE is Microsoft's framework for a compound document technology. Briefly, a compound document is something like a display desktop that can contain visual and information objects of all kinds: text, calendars, animations, sound, motion video, 3-D, continually updated news, controls, and so forth. Each desktop object is an independent program entity that can interact with a user and also communicate with other objects on the desktop. Part of Microsoft's ActiveX technologies, OLE takes advantage and is part of a larger, more general concept, the COM and its distributed version, DCOM. An OLE object is necessarily also a component (or COM object).

OMG (The Object Management Group): was founded in April 1989 by eleven companies, including 3Com, American Airlines, Canon, Data General, Hewlett-Packard, Philips Telecommunications, Sun Microsystems and Unisys Corporation. In October 1989, the OMG began independent operations as a not-for-profit corporation. Today the consortium includes about 800 members. The OMG is moving forward in establishing CORBA as the "Middleware that's Everywhere" through its worldwide standard specifications. http://www.omg.org.

OMS (Outage Management System): supports the detection and management of outages affecting the distribution system.

One-Banana Problem: A measure of difficulty of a problem. A one-banana problem is simple, whereas a three-banana problem is fairly difficult. This term derives from large computer organizations where the programmers & engineers claim that the computer operators could be monkeys.

Online: Being actively connected to a network such as the Internet.

Online Certificate Status Protocol (OCSP): OCSP is one of two common schemes for maintaining the security of a server and other network resources. The other, older method, which OCSP has
superseded in some scenarios, is known as Certificate Revocation List (CRL). OCSP overcomes the chief limitation of CRL: the fact that updates must be frequently dowloaded to keep the list current at the client end. When a user attempts to access a server, OCSP sends a request for certificate status information. The server sends back a response of "current", "expired," or "unknown." The protocol specifies the syntax for communication between the server (which contains the certificate status) and the client application (which is informed of that status). OCSP allows users with expired certificates a grace period, so they can access servers for a limited time before renewing.

Online Services: A dial-up service that provides news, information, and discussion forums for users with modem-equipped PCs and the access software provided by the service. Online services may provide a gateway to the Internet but their services are not normally available to anyone that does not subscribe to their service, making it proprietary.

Ontology: In its general meaning, ontology is the study or concern about what kinds of things exist - what entities there are in the universe. It derives from the Greek onto (being) and logia (written or spoken discourse). It is a branch of metaphysics, the study of first principles or the essence of things. In information technology, an ontology is the working model of entities and interactions in some particular domain of knowledge or practices, such as electronic commerce or "the activity of planning."  In this usage, an ontology is a set of concepts - such as things, events, and relations - that are specified in some way (such as specific natural language or an object modeling language) in order to create an agreed-upon vocabulary for exchanging information.  [WhatIs.com] The Common Information Model (CIM) is an ontology of the entities and interactions within the electric power system domain.

OPC Foundation: The OPC Foundation has developed the OPC Specification, which is a non-proprietary technical specification that defines a set of standard interfaces based upon Microsoft’s OLE/COM technology. The application of the OPC standard interface makes possible interoperability between automation/control applications, field systems/devices and business/office applications. See OPC Foundation.

Open Access: A regulatory mandate to allow others to use a utility's transmission and distribution facilities to move bulk power from one point to another on a nondiscriminatory basis for a cost-based fee.  [DOE Glossary of Electricity Terms]

Open System: A model that allows two different systems to communicate regardless of their underlying architecture.

Open Systems Interconnection--Reference Model (OSI--RM): An abstract description of the digital communications between application processes running in distinct systems. The model employs a hierarchical structure of seven layers. Each layer performs value-added service at the request of the adjacent higher layer and, in turn, requests more basic services from the adjacent lower layer:

• Physical Layer: Layer 1. The lowest of seven hierarchical layers. The Physical layer performs services requested by the Data Link Layer. The major functions and services performed by the physical layer are: (a) establishment and termination of a connection to a communications medium; (b) participation in the process whereby the communication resources are effectively shared among multiple users, e.g., contention resolution and flow control; and, (c) conversion between the representation of digital data in user equipment and the corresponding signals transmitted over a communications channel.

• Data Link Layer: Layer 2. This layer responds to service requests from the Network Layer and issues service requests to the Physical Layer. The Data Link Layer provides the functional and procedural means to transfer data between network entities and to detect and possibly correct errors that may occur in the Physical Layer. Note: Examples of data link protocols are HDLC and ADCCP for point-to-point or packet-switched networks and LLC for local area networks.

• Network Layer: Layer 3. This layer responds to service requests from the Transport Layer and issues service requests to the Data Link Layer. The Network Layer provides the functional and procedural means of transferring variable length data sequences from a source to a destination via one or more networks while maintaining the quality of service requested by the Transport Layer. The Network Layer performs network routing, flow control, segmentation/desegmentation, and error control functions.

• Transport Layer: Layer 4. This layer responds to service requests from the Session Layer and issues service requests to the Network Layer. The purpose of the Transport Layer is to provide transparent transfer of data between end users, thus relieving the upper layers from any concern with providing reliable and cost-effective data transfer.

• Session Layer: Layer 5. This layer responds to service requests from the Presentation Layer and issues service requests to the Transport Layer. The Session Layer provides the mechanism for managing the dialogue between end-user application processes. It provides for either duplex or half-duplex operation and establishes checkpointing, adjournment, termination, and restart procedures.

• Presentation Layer: Layer 6. This layer responds to service requests from the Application Layer and issues service requests to the Session Layer. The Presentation Layer relieves the Application Layer of concern regarding syntactical differences in data representation within the end-user systems. Note: An example of a presentation service would be the conversion of an EBCDIC-coded text file to an ASCII-coded file.

• Application Layer: Layer 7, the highest layer. This layer interfaces directly to and performs common application services for the application processes; it also issues requests to the Presentation Layer. The common application services provide semantic conversion between associated application processes. Note: Examples of common application services of general interest include the virtual file, virtual terminal, and job transfer and manipulation protocols.

 [T1 Glossary 2000: Glossary of Telecommunications Terms] 

Operating Day - A period from 00:00 hrs. to 24:00 hrs. when the schedules of operation of the grid and the generating units are implemented.

Operating Reserve: additional output from power stations or the reduction in demand, which must be realisable in real-time operation to respond in order to contribute to containing and correcting any system frequency fall to an acceptable level in the event of a loss of generation or a loss of import from an external interconnection or mismatch between generation and demand.  [IEC_Glossary_1929b.pdf]

Operating System (OS): The foundation software of a machine. The software that schedules tasks, allocates memory, disk storage, and presents an interface to the user. See Windows and UNIX.

OS: see Operating System.

OSI Reference Model (Open Systems Interconnection Reference Model): A seven-layer model for data communication defined by the ISO. The Open Systems Interconnection (OSI) is a standard reference model for communication between two end users in a network. It is used in developing products and understanding networks. The OSI reference model was developed by the ISO in 1984, and it is now considered the primary architectural model for inter-computer communications. The OSI Reference Model consists of seven layers. The top three layers (session, presentation, and application) are primarily of concern when building distributed applications programs using the services provided by the network. They are generally implemented only in software. The data transport aspects are covered with the protocols operating at the bottom four layers (physical, data link, network, and transport) in the OSI reference model. Information being transferred from a software application in one computer system to a software application in another must pass through each of the OSI layers. 

Open Systems Interconnection--Reference Model (OSI--RM): An abstract description of the digital communications between application processes running in distinct systems. The model employs a hierarchical structure of seven layers. Each layer performs value-added service at the request of the adjacent higher layer and, in turn, requests more basic services from the adjacent lower layer. The layers can be summarized as follows:

• Physical Layer: Layer 1. The lowest of seven hierarchical layers. The Physical layer performs services requested by the Data Link Layer. The major functions and services performed by the physical layer are: (a) establishment and termination of a connection to a communications medium; (b) participation in the process whereby the communication resources are effectively shared among multiple users, e.g., contention resolution and flow control; and, (c) conversion between the representation of digital data in user equipment and the corresponding signals transmitted over a communications channel.

• Data Link Layer: Layer 2. This layer responds to service requests from the Network Layer and issues service requests to the Physical Layer. The Data Link Layer provides the functional and procedural means to transfer data between network entities and to detect and possibly correct errors that may occur in the Physical Layer. Note: Examples of data link protocols are HDLC and ADCCP for point-to-point or packet-switched networks and LLC for local area networks.

• Network Layer: Layer 3. This layer responds to service requests from the Transport Layer and issues service requests to the Data Link Layer. The Network Layer provides the functional and procedural means of transferring variable length data sequences from a source to a destination via one or more networks while maintaining the quality of service requested by the Transport Layer. The Network Layer performs network routing, flow control, segmentation/desegmentation, and error control functions.

• Transport Layer: Layer 4. This layer responds to service requests from the Session Layer and issues service requests to the Network Layer. The purpose of the Transport Layer is to provide transparent transfer of data between end users, thus relieving the upper layers from any concern with providing reliable and cost-effective data transfer.

• Session Layer: Layer 5. This layer responds to service requests from the Presentation Layer and issues service requests to the Transport Layer. The Session Layer provides the mechanism for managing the dialogue between end-user application processes. It provides for either duplex or half-duplex operation and establishes checkpointing, adjournment, termination, and restart procedures.

• Presentation Layer: Layer 6. This layer responds to service requests from the Application Layer and issues service requests to the Session Layer. The Presentation Layer relieves the Application Layer of concern regarding syntactical differences in data representation within the end-user systems. Note: An example of a presentation service would be the conversion of an EBCDIC-coded text file to an ASCII-coded file.

• Application Layer: Layer 7, the highest layer. This layer interfaces directly to and performs common application services for the application processes; it also issues requests to the Presentation Layer. The common application services provide semantic conversion between associated application processes. Note: Examples of common application services of general interest include the virtual file, virtual terminal, and job transfer and manipulation protocols

 [T1 Glossary 2000: Glossary of Telecommunications Terms] 

OSPF (Open Shortest Path First): OSPF is a link-state routing protocol. It is designed to be run internal to a single Autonomous System. Compare RIP and BGP.

Outage: The period during which a generating unit, transmission line, or other facility is out of service.  [DOE Glossary of Electricity Terms]

Outbox: The place where outgoing mail is put prior to being sent on to the mail server. The outbox can also be configured in many e-mail clients to save a copy of all outgoing e-mail for future reference.

Overhead: In communications, all information, such as control, routing, and error-checking characters, that is in addition to user-transmitted data; includes information that carries network status or operational instructions, network routing information, and retransmissions of user data messages that are received in error.