Showing papers on "Node (networking) published in 1972"

Improvements in the design and performance of the ARPA network

Abstract: In late 1968 the Advanced Research Projects Agency of the Department of Defense (ARPA) embarked on the implementation of a new type of computer network which would interconnect, via common-carrier circuits, a number of dissimilar computers at widely separated, ARPA-sponsored research centers. The primary purpose of this interconnection was resource sharing, whereby persons and programs at one research center might access data and interactively use programs that exist and run in other computers of the network. The interconnection was to be realized using wideband leased lines and the technique of message switching, wherein a dedicated path is not set up between computers desiring to communicate, but instead the communication takes place through a sequence of messages each of which carries an address. A message generally traverses several network nodes in going from source to destination, and at each node a copy of the message is stored until it is safely received at the following node.

Finding the Lengths of All Shortest paths in N -Node Nonnegative-Distance Complete Networks Using ½N3 Additions and N3 Comparisons

Abstract: A (computer programming) algorithm is presented which is based on Dijkstra 's principle for finding the lengths of all shortest paths from either a fixed node or from all nodes in N-node nonnegative-distance complete networks. This algorithm is more efficient than other available (computer programming) algorithms known to the author for solving the above two problems. An empirical study on a computer has confirmed its superiority.

The multicommodity network flow model revised to include vehicle per time period and node constraints

Abstract: THE MINIMUM-COST FORMULATION OF THE PROBLEM OF DETERMINING MULTICOMMODITY FLOWS OVER A CAPACITATED NETWORK SUBJECT TO RESOURCE CONSTRAINTS HAS BEEN TREATED IN PREVIOUS PAPERS. IN THOSE TREATMENTS ONLY CAPACITATED ARCS WERE ASSUMED, AND A UNIFORM UNIT OF MEASURE LIKE SHORT TONS WAS USED FOR ALL COMMODITIES. THIS PAPER TREATS THE EFFECT OF CONSTRAINTS ON THE NODES OF THE NETWORK, ALLOWS THE COMMODITIES TO BE MEASUREED IN THEIR "NATURAL" UNITS, AND ALLOWS THE NETWORK CAPACITIES TO BE EXPRESSED IN VEHICLES PER TIME PERIOD - IN SOME CASES GIVING A MORE ACCURATE REPRESENTATION OF THE CAPACITIES OF THE NETWORK. THIS PAPER DESCRIBES THE SOLUTION PROCEDURE WHICH USES THE COLUMN GENERATION TECHNIQUE; IT ALSO DISCUSSES COMPUTATIONAL EXPERIENCE. /AUTHOR/

Data processing apparatus

Abstract: Data processing apparatus arranged to perform a method for the search, simultaneously in several networks, for a set of optimum component trajectories respecting constraints of inter-dependence of these networks, these trajectories connecting in each network a starting point node and a target point node ; this method is carried out by performing a series of retrograde investigations from a final situation to an initial situation and thus determining step by step the desired set of optimum component trajectories ; the apparatus may include : centers for simulating each network, centers of association of nodes or links of different networks for simulating the inter-dependence constraints of the networks, posting members for target and starting points nodes, a center of coordination for coordinating the transmission of signals to a number of lines which connect said different centers with the aid of temporary memories.

Parametric Network Flows

Abstract: This paper considers a directed capacitated network in which the supply at each source node and the demand at each sink node is a linear function of a parameter t. It presents two algorithms that determine the range of values for the parameter t; they correspond to the primal and dual linear-programming algorithms that solve this problem. The dual algorithm appears to have a simpler structure.

A note on the optimality of some all-shortest-path algorithms

Abstract: It is proved that any algorithm that determines the shortest distances between all node pairs in a network by repeated applications of the so-called triple-operations should contain at least n(n-1)(n-2) such operations, where n is the number of nodes in the network. Hence, FIoyd's algorithm [2J, as well as Dantzig's [lJ and Katayama and Watanabe's [5J, has been shown to be optimal.

Delay distributions in message-switching networks

Abstract: Waiting-time probability distributions P(>t) are given for a message-switching network optimized according to either of the following criteria: minimize the average network delay, or minimize the maximum of all link or node delays, respectively. The results show that the difference in distributions is small.