The resource discovery problem arises in the context of peer to peer (P2P) networks, where at any point of time a peer may be placed at or removed from any location over a general purpose network (e.g., an Internet si...
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The resource discovery problem arises in the context of peer to peer (P2P) networks, where at any point of time a peer may be placed at or removed from any location over a general purpose network (e.g., an Internet site). A vertex (peer) can communicate with another vertex directly if and only if it knows a certain routing information to that other vertex. Hence, it is critical for peers to convey this routing information to each other. The problem was formalized by Harchol-Balter et al. (1999). The routing information needed for a vertex to reach another peer is that peer's identifier (e.g., IP address). A logical directed edge represents the fact that the peer at the tail of the edge knows the IP address of the one at its head. A number of algorithms were developed by Harchol-Balter et al. for this problem in the model of a synchronous network over a weakly connected directed graph. The best of these algorithms was randomized. Subsequently, a deterministic algorithm for the problem on synchronous networks with improved complexity was presented by Kutten et al. (2001). The current paper extends this deterministic algorithm to the environment of asynchronous networks, maintaining similar complexities (translated to the asynchronous model). These are lower than the complexities that would be needed to synchronize the system. The main technical difficulty in a directed, weakly connected system is to ensure that vertices take consistent steps, even if their knowledge about each other is not symmetric, and even if there is no timeout mechanism (which does exist in synchronous systems) to assist in that.
We present a combinatorial theorem which generalizes an identity of Feller and applies it to the study of returns to the origin for the symmetric random walk on ℤ.
We present a combinatorial theorem which generalizes an identity of Feller and applies it to the study of returns to the origin for the symmetric random walk on ℤ.
In comparison to PI and PID controllers, a higher order “advanced” controller is shown to improve the performance of an experimental robot for speed and position control applications. The advanced controller attains...
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In comparison to PI and PID controllers, a higher order “advanced” controller is shown to improve the performance of an experimental robot for speed and position control applications. The advanced controller attains a higher bandwidth, lower settling time and better disturbance rejection, while the increased performance costs little in sensor noise amplification.
On the basis of Ref.\, the M x/G(M/G)/1 repairable queueing system with single delay vacation is discussed again. The following reliability problems of the service station are studied: (a) The probability that it fai...
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On the basis of Ref.\, the M x/G(M/G)/1 repairable queueing system with single delay vacation is discussed again. The following reliability problems of the service station are studied: (a) The probability that it fails at time t , i.e. its unavailability; (b) The expected failure number during the time interval (0,t\];; (c) The expected failure number during the ″server busy period″; (d) The expected downtime during the time interval (0,t\]. Some reliability results of the service station are obtained. These results would be interest to reliability analysts.
In this paper we show that any two-party functionality canbe securely computed in a constant number of rounds, where security isobtained against malicious adversaries that may arbitrarily deviate fromthe protocol spec...
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We present session-key generation protocols in a model where the legitimate parties share only a human-memorizable password. The security guarantee holds with respect to probabilistic polynomial-time adversaries that ...
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The biological function of proteins is dependent, to a large extent, on their native three dimensional conformation. Thus, it is important to know the structure of as many proteins as possible. Since experimental meth...
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The biological function of proteins is dependent, to a large extent, on their native three dimensional conformation. Thus, it is important to know the structure of as many proteins as possible. Since experimental methods for structure determination are very tedious, there is a significant effort to calculate the structure of a protein from its linear sequence. Direct methods of calculating structure from sequence are not available yet. Thus, an indirect approach to predict the conformation of protein, called threading, is discussed. In this approach, known structures are used as constraints, to restrict the search for the native conformation. Threading requires finding good alignments between a sequence and a structure, which is a major computational challenge and a practical bottleneck in applying threading procedures. The Genetic Algorithm paradigm, an efficient search method that is based on evolutionary ideas, is used to perform sequence to structure alignments. A proper representation is discussed in which genetic operators can be effectively implemented. The algorithm performance is tested for a set of six sequence/structure pairs. The effects of changing operators and parameters are explored and analyzed.
A parallel computation model that takes advantage of a networking infrastructure that enables server-free resource sharing based on the Jini approach is described. The network is a connected network of nodes that dire...
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ISBN:
(纸本)1581134282
A parallel computation model that takes advantage of a networking infrastructure that enables server-free resource sharing based on the Jini approach is described. The network is a connected network of nodes that directly know their neighborhood but can access the entire network. The constructed network infrastructure of handheld machines tolerates the dynamic nature of a mobile ad hoc network and provides the foundation for applications to take advantage of this type of computing network.
In order to model the behaviour of open concurrent systems by means of Petri nets, we introduce open Petri nets, a generalization of the ordinary model where some places, designated as open, represent an interface of ...
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Industrial-size specifications/models (whose state space is often infinite) can not be model checked in a direct way - A verification model of a system is model checked instead. Program transformation is a way to buil...
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