Computer Science (UGC/NET)

The graph isomorphism problem is suspected to be neither in P nor NP-complete, though it is in NP. This is an example of a problem that is thought to be hard, but is not thought to be NP-complete.

FOAF (an acronym of Friend of a friend) is a machine-readable ontology describing persons, their activities and their relations to other people and objects. Anyone can use FOAF to describe him- or herself. FOAF allows groups of people to describe social networks without the need for a centralised database.

In computer science, a loop is a programming language statement that allows code to be repeatedly executed; an invariant of a loop is a property that holds before (and after) each repetition. It is a logical assertion, sometimes programmed as an assertion. Knowing its invariant(s) is essential for understanding the effect of a loop.

Insertion sort provides several advantages such as simple implementation, efficient for (quite) small data sets, more efficient in practice than most other simple quadratic (i.e., O(n2)) algorithms such as selection sort or bubble sort, adaptive, i.e., efficient for data sets that are already substantially sorted: the time complexity is O(nk) when each element in the input is no more than k places away from its sorted position, stable; i.e. does not change the relative order of elements with equal keys, in-place; i.e., only requires a constant amount O(1) of additional memory space,online; i.e., can sort a list as it receives it.

A splay tree is a self-adjusting binary search tree with the additional property that recently accessed elements are quick to access again. It performs basic operations such as insertion, look-up and removal in O(log n) amortized time.

Remote Initial Program Load (RIPL or RPL) is a protocol for starting a computer and loading its operating system from server via a network. Such a server runs a network operating system such as LAN Manager, LAN Server, Windows NT Server, Novell NetWare, Solaris or Linux.

Red–black trees, like all binary search trees, allow efficient in-order traversal (that is: in the order Left–Root–Right) of their elements. The search-time results from the traversal from root to leaf, and therefore a balanced tree of n nodes, having the least possible tree height, results in O(log n) search time.

Reification is the process by which an abstract idea about a computer program is turned into an explicit data model or other object created in a programming language. A computable/addressable object — a resource — is created in a system as a proxy for a non computable/addressable object. By means of reification, something that was previously implicit, unexpressed, and possibly inexpressible is explicitly formulated and made available to conceptual (logical or computational) manipulation. Informally, reification is often referred to as making something a first-class citizen within the scope of a particular system. Some aspect of a system can be reified at language design time, which is related to reflection in programming languages. It can be applied as a stepwise refinement at system design time. Reification is one of the most frequently used techniques of conceptual analysis and knowledge representation.

The Bootstrap Protocol (BOOTP) is a computer networking protocol used in Internet Protocol networks to automatically assign an IP address to network devices from a configuration server.

Semantic P2P networks are a new type of P2P network. It combines the advantages of unstructured P2P networks and structural P2P networks and avoids their disadvantages.In semantic P2P networks, nodes are classified as DNS-like domain names with semantic meanings such as Alice @Brittney.popular.music. Semantic P2P networks contains prerequisite virtual tree topology and net-like topology formed by cached nodes.

A factless fact table is fact table that does not contain fact.They contain only dimesional keys and it captures events that happen only at information level but not included in the calculations level.just an information about an event that happen over a period.

A dereferenceable Uniform Resource Identifier or dereferenceable URI is a resource retrieval mechanism that uses any of the internet protocols (e.g. HTTP) to obtain a copy or representation of the resource it identifies.

Automatic Repeat reQuest (ARQ), also known as Automatic Repeat Query, is an error-control method for data transmission that uses acknowledgements (messages sent by the receiver indicating that it has correctly received a data frame or packet) and timeouts (specified periods of time allowed to elapse before an acknowledgment is to be received) to achieve reliable data transmission over an unreliable service. If the sender does not receive an acknowledgment before the timeout, it usually re-transmits the frame/packet until the sender receives an acknowledgment or exceeds a predefined number of re-transmissions.ARQ protocols reside in the Data Link or Transport Layers of the OSI model.

IEEE 1394 is an interface standard for a serial bus for high-speed communications and isochronous real-time data transfer. It was developed in the late 1980s and early 1990s by Apple, that called it FireWire.

Satellite data refers to any payload data which you want to store in your data structure and which is not part of the structure of the data structure. It can be anything you want. It can be a single value, a large collection of values or a pointer to some other location that holds the value.