3,409 research outputs found
The ALOHA SYSTEM
The report provides a status report and description of THE ALOHA SYSTEM research project at the University of Hawaii. THE ALOHA SYSTEM involves the analysis and construction of advanced methods of random access communications in large computer-communication systems. The existing ALOHA SYSTEM computer-communication network uses two 24,000 baud channels in the UHF band. The system employs message switching techniques similar to those of the ARPANET, in conjunction with a novel form of random access radio channel multiplexing. By means of these techniques the system has the capacity to accommodate several hundred active users of alphanumeric consoles on the two channels available. Each of these users can transmit and receive at a peak data rate of 24,000 baud although the average data rate of the users must of course be considerably less
Refracting profiles and generalized holodiagrams
The recently developed concept of refracting profiles and that of refraction
holodiagrams are combined so that the classical Abramson holodiagrams can be
generalized taking into account a wider class of wave fronts and refraction at
an interface, whenever regions of caustics are avoided. These holodiagrams are
obtained as envelopes of specific families of Cartesian Ovals with an
appropriate parametrization. Classical and reflecting holodiagrams are
particular cases of this class. Several of the properties of the classical
holodiagrams are shared by their richer generalized versionsComment: 12 pages, 7 figure
Further studies of liquid sloshing in rocket propellant tanks Final report, 25 Mar. 1961 - 31 Dec. 1965
Liquid sloshing and dynamics in rocket propellant tanks annotated bibliography with abstract
A random walk model to study the cycles emerging from the exploration-exploitation trade-off
We present a model for a random walk with memory, phenomenologically inspired
in a biological system. The walker has the capacity to remember the time of the
last visit to each site and the step taken from there. This memory affects the
behavior of the walker each time it reaches an already visited site modulating
the probability of repeating previous moves. This probability increases with
the time elapsed from the last visit. A biological analog of the walker is a
frugivore, with the lattice sites representing plants. The memory effect can be
associated with the time needed by plants to recover its fruit load. We propose
two different strategies, conservative and explorative, as well as intermediate
cases, leading to non intuitive interesting results, such as the emergence of
cycles.Comment: To appear in Phys. Rev.
MEASUREMENTS OF LIQUID DAMPING PROVIDED BY RING BAFFLES IN CYLINDRICAL TANKS
Damping effect of flat ring baffles on liquid sloshing in partially filled cylindrical tank
Longitudinal vibration of ring stiffened cylindrical shells containing liquids Technical report no. 7
Longitudinal vibration of ring stiffened cylindrical shells containing liquids for application to liquid fueled space vehicle booster
Associative memory on a small-world neural network
We study a model of associative memory based on a neural network with
small-world structure. The efficacy of the network to retrieve one of the
stored patterns exhibits a phase transition at a finite value of the disorder.
The more ordered networks are unable to recover the patterns, and are always
attracted to mixture states. Besides, for a range of the number of stored
patterns, the efficacy has a maximum at an intermediate value of the disorder.
We also give a statistical characterization of the attractors for all values of
the disorder of the network.Comment: 5 pages, 4 figures (eps
Research in the Aloha system
The Aloha system was studied and developed and extended to advanced forms of computer communications networks. Theoretical and simulation studies of Aloha type radio channels for use in packet switched communications networks were performed. Improved versions of the Aloha communications techniques and their extensions were tested experimentally. A packet radio repeater suitable for use with the Aloha system operational network was developed. General studies of the organization of multiprocessor systems centered on the development of the BCC 500 computer were concluded
Some Notes on Liquid Sloshing in Compartmented Cylindrical Tanks Technical Report No. 1
Frequencies and total force response in rigid cylindrical tanks comparted into sectors by vertical walls and excited in translation to study liquid sloshin
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