By utilizing a new network protocol, Locator/Identifier Separation Protocol (LISP), a global IP multicasting system can be achieved without modifying protocol stacks of routers on the Internet. A mapping system which ...
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ISBN:
(纸本)9781457720710
By utilizing a new network protocol, Locator/Identifier Separation Protocol (LISP), a global IP multicasting system can be achieved without modifying protocol stacks of routers on the Internet. A mapping system which manages relationship between each multicast group and the group members is a core component of the system, but the centralized system requires costly resources for handling a large-scale network. In this study, a new decentralized mapping system for LISP-based information multicasting system is proposed. The proposed system utilizes a structured P2P network consisting of LISP routers to manage the membership information of multicast groups, and collaborates with two proximity-aware methods in order to shorten the start-up time needed for newly-arrived multicast members to start communicating with other members. The first method enables LISP routers to connect to lower-latency neighbors, and the second one replicates the membership information on a router which is close to all group members. This paper considers the performance of the proposed system by using a large-scale computer simulation and clarifies that the proposed mapping system with both methods can halve the start-up time compared with the simple P2P-based system.
This paper considers the input-erasure Gaussian channel. In contrast to the output-erasure channel where erasures are applied to the output of a linear time-invariant (LTI) system, here erasures, known to the receiver...
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This paper considers the input-erasure Gaussian channel. In contrast to the output-erasure channel where erasures are applied to the output of a linear time-invariant (LTI) system, here erasures, known to the receiver, are applied to the inputs of the LTI system. Focusing on the case where the input symbols are independent and identically distributed (i.i.d)., it is shown that the two channels (input- and output-erasure) are equivalent. Furthermore, assuming that the LTI system consists of a two-tap finite impulse response (FIR) filter, and using simple properties of tri-diagonal matrices, an achievable rate expression is presented in the form of an infinite sum. The results are then used to study the benefits of joint multicell processing (MCP) over single-cell processing (SCP) in a simple linear cellular uplink, where each mobile terminal is received by only the two nearby base-stations (BSs). Specifically, the analysis accounts for ergodic shadowing that simultaneously blocks the mobile terminal (MT) signal from being received by the two BS. It is shown that the resulting ergodic per-cell capacity with optimal MCP is equivalent to that of the two-tap input-erasure channel. Finally, the same cellular uplink is addressed by accounting for dynamic user activity, which is modelled by assuming that each MT is randomly selected to be active or to remain silent throughout the whole transmission block. For this alternative model, a similar equivalence results to the input-erasure channel are reported.
The concept of a low-cost talking book is under development by the authors who are motivated by their concern for current reading and teaching methods both with and without the aid of the personal computer. While many...
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The concept of a low-cost talking book is under development by the authors who are motivated by their concern for current reading and teaching methods both with and without the aid of the personal computer. While many children are electronic game and television literate, and interactive learning systems, particularly multimedia ones, can be very effective, there are still barriers to the general acceptability of computer-based reading aids. These barriers are largely to do with: high cost, the user-interface, and the lack of personal contact and sharing, all of which are currently better handled with paper-based documents. For example books are cheap, and there is a close one-to-one contact with the teacher during reading practice. The talking book is designed to provide the feedback that would occur between teacher and child during normal reading and are invoked by the child selecting letter, words, sentences and pictures with a stylus. Details of the letter, word, and sentence selection algorithms are given together with digital speech algorithms that enable the speech to be intelligible and acceptable.
Functional Near Infrared Spectroscopy (fNIRS) is a non invasive functional neuroimaging method used for studying brain activity using blood oxygen level dependent (BOLD) signal. We use phase synchronization between fN...
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ISBN:
(纸本)9781424441198
Functional Near Infrared Spectroscopy (fNIRS) is a non invasive functional neuroimaging method used for studying brain activity using blood oxygen level dependent (BOLD) signal. We use phase synchronization between fNIRS channels to detect functional connections between brain regions in a speech study. Data is collected from 22 neonates whose brain activity was monitored by fNIRS while being exposed to two different types of auditory stimuli. The wavelet based phase locking analysis reveals functional connections between temporal regions and most other regions in general and frontal areas in particular.
The ability to predict slant path rain-induced attenuation is an essential tool for system design. While a number of prediction methodologies from which it is possible to characterize the entire European region have b...
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The ability to predict slant path rain-induced attenuation is an essential tool for system design. While a number of prediction methodologies from which it is possible to characterize the entire European region have been developed, the validity of such models can only be checked by direct measurement of experimental satellite beacons. This paper considers the selection criteria for beacon receiver sites. Rain models predict attenuation. This paper describes an investigation in which attenuation predictions have been calculated using a number of models at each of 1700 points in Europe. From these computations, contour maps have been prepared indicating, for different frequencies and polarizations, the extent to which site-related parameters cause disagreement between the various attenuation prediction methods at locations throughout Europe.
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