Telcordia Technologies

About: Telcordia Technologies is a based out in . It is known for research contribution in the topics: Network packet & Node (networking). The organization has 3097 authors who have published 4737 publications receiving 237882 citations.

Positive Hall coefficient observed in single-crystal Nd 2 − x Ce x CuO 4 − δ at low temperatures

Abstract: The Hall coefficient ${\mathit{R}}_{\mathit{H}}$ has been measured in superconducting single crystals of ${\mathrm{Nd}}_{2\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Ce}}_{\mathit{x}}$${\mathrm{CuO}}_{4\mathrm{\ensuremath{-}}\mathrm{\ensuremath{\delta}}}$(x\ensuremath{\sim}015) Although ${\mathit{R}}_{\mathit{H}}$ is sample dependent in sign above \ensuremath{\sim}100 K, it increases steeply to positive values in all crystals studied below \ensuremath{\sim}80 K ${\mathit{R}}_{\mathit{H}}$ remains T (temperature) dependent at 2 K, in contrast to the resistivity ${\mathrm{\ensuremath{\rho}}}_{\mathit{a}}$ which saturates to a constant below 30 K Using a two-band model, we account for the observed profiles of ${\mathit{R}}_{\mathit{H}}$ vs T and ${\mathrm{\ensuremath{\rho}}}_{\mathit{a}}$ vs T The analysis reveals that the scattering processes for the electronlike and holelike bands have vastly different temperature scales The hole-scattering rate remains T dependent to 2 K The question whether the hole or the electron quasiparticles are responsible for the superconductivity in ${\mathrm{Nd}}_{2\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Ce}}_{\mathit{x}}$${\mathrm{CuO}}_{4\mathrm{\ensuremath{-}}\mathrm{\ensuremath{\delta}}}$ is discussed

Locating program features using execution slices

Abstract: An important step towards effective software maintenance is to locate the code relevant to a particular feature. We report a study applying an execution slice-based technique to a reliability and performance evaluator to identify the code which is unique to a feature, or is common to a group of features. Supported by tools called ATAC and /spl chi/Vue, the program features in the source code can be tracked down to files, functions, lines of code, decisions, and then c- or p-uses. Our study suggests that the technique can provide software programmers and maintainers with a good starting point for quick program understanding.

Multicast routing algorithm

Abstract: A method for routing data packets correctly and efficiently among a plurality of hosts in a multicast is disclosed. The hosts are connected to a packet switching network comprising a plurality of packet switches interconnected by trunks. A memory associated with the route controller in each switch maintains a table whose entries are tuples of the form . In the case of multicast routing, the address is a multicast address. The trunk identification number is a number which uniquely identifies each of the trunks connected to the switch. Time is a timing parameter which is initially set to a certain predetermined value (designated Maxtime herein) and decremented periodically. When time reaches zero, the associated table entry is cleared. When a host wishes to join a multicast conversation (even if it is the first participant), it simply transmits a packet from itself to the multicast adddress. This packet will be broadcast over the entire spanning tree network. The host then continues to send packets to the multicast address, with a maximum interpacket time interval, smaller than Maxtime, to insure that at least one of the relevant table entries is not cleared.

Apparatus and methods for highly available directory services in the distributed computing environment

Abstract: In the Distributed Computing Environment (DCE) standard, availability of directory services is increased by apparatus and methods using agents inserted between requesting clients and servers. By using agents, additional functions are carried out which are not performed in a typical DCE environment. Each agent (68) inserts itself between the requesters (78) and servers (60) by writing over the pointer to the server (60) with information pointing to the agent (68), thus redirecting requests to themselves. The agent (68) then receives incoming requests and forwards them on to its associated server (62) and other agents (76). The agent (68) handling requests for the master server (60) is called the 'master' agent and the agents handling requests for replica servers are 'replica' agents. The agents make sure requests are performed before replying to the original requester. Agents also monitor themselves. If a master agent (68) crashes, the remaining agents (76) elect a new master agent. If a replica agent (76) crashes, the master agent excludes the agent (76) from further communications. The apparatus and methods provide a highly available and robust directory server.

Learning to use a text editor: some learner characteristics that predict success

Abstract: Why do some people have much more difficulty than others in learning a computer-based skill? To answer this question, we observed first-time users of computers as they learned to use a computer text editor. In two experiments, older people had more trouble than younger people and those who scored low on a standard test of spatial memory had greater diffkulty than high scorers. These correlations were stable over several hours of practice and did not vary as a function of the type of terminal used or specific editing problems attempted. Correlations involving age and spatial memory could not be explained by other characteristics such as amount of education, reasoning ability, or associative memory ability. Results like these that relate learning diffkulty to specific characteristics of people ultimately may suggest ways to change computer interface design or training to accommodate a wider range of users.