This paper concerns the attainment of QoS on a network and focuses on the management of two resources on routers: the link bandwidth and the CPU for achieving fair share resource management. A comparative analysis of ...
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ISBN:
(纸本)9781622763504
This paper concerns the attainment of QoS on a network and focuses on the management of two resources on routers: the link bandwidth and the CPU for achieving fair share resource management. A comparative analysis of four different schedulers is performed. In addition to CPU scheduling, this paper also investigates three different packet-dropping policies. Based on measurements made on a performance prototype of routers, insights into system behaviour and performance are presented.
Chipless RFID readers widely use two antennas for the interrogation of the tag and reception of the response, making them heavy and bulky. Also, the strong self-jamming leakage signal degrades the sensitivity of the r...
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Density evolution is often used to determine the performance of an ensemble of low-density parity-check (LDPC) codes under iterative message-passing algorithms. Conventional density evolution techniques over memoryles...
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ISBN:
(纸本)9781424463725
Density evolution is often used to determine the performance of an ensemble of low-density parity-check (LDPC) codes under iterative message-passing algorithms. Conventional density evolution techniques over memoryless channels are based on the independence assumption amongst all the processed messages in variable and check nodes. This assumption is valid for many algorithms such as standard belief propagation (BP) and min-sum (MS) algorithms. However, there are other important iterative algorithms such as successive relaxation (SR) versions of BP and MS, and differential decoding with binary message passing (DD-BMP) algorithm of Mobini et. al., for which this assumption is not valid. The dependence created among messages for these algorithms is due to the introduction of memory in the iterative algorithm. In this work, we propose a model for iterative decoding algorithms with memory which covers SR and DD-BMP algorithms as special cases. Based on this model, we derive a Bayesian network for iterative algorithms with memory over memoryless channels and use this representation to analyze the algorithms using density evolution. The density evolution technique is developed based on truncating the memory of the decoding process and approximating it with a finite order Markov process, and can be implemented efficiently. As an example, we apply our technique to analyze the performance of DD-BMP on regular LDPC code ensembles, and make a number of interesting observations with regard to the performance/complexity trade off of DD-BMP in comparison with BP and MS algorithms.
Random wandering is among the most frequently implemented mobile robotic behaviours. This paper presents a bio-inspired controller for mobile robots that generates deterministic wandering behaviour. Some results from ...
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ISBN:
(纸本)9783902661876
Random wandering is among the most frequently implemented mobile robotic behaviours. This paper presents a bio-inspired controller for mobile robots that generates deterministic wandering behaviour. Some results from the controller are derived theoretically and tested through simulations for symmetric cases, when analytic solutions are available. A technique to deal with non closed form wandering trajectories is also presented in a simple case study application.
We propose steering behavior model to simulate virtual characters (NPC) which walk around in virtual exhibition environment and see exhibits one by one just like humans do. Steering behavior model of such environment ...
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Animals show a great ability to move on real world. Taxis is a motion control technique used by simple animals. In this paper mathematical equations are derived from a taxis model for non-holonomous vehicles. A qualit...
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ISBN:
(纸本)9783902661654
Animals show a great ability to move on real world. Taxis is a motion control technique used by simple animals. In this paper mathematical equations are derived from a taxis model for non-holonomous vehicles. A qualitative technique is applied to analyse the solutions of the nonlinear derived motion equations. To validate the model and qualitative analysis several simulations are performed.
Quality of service requirements are normally given in terms of soft deadlines, such as "90% of responses should complete within one second". To estimate the probability of meeting the target delay, one must ...
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ISBN:
(纸本)1595930876
Quality of service requirements are normally given in terms of soft deadlines, such as "90% of responses should complete within one second". To estimate the probability of meeting the target delay, one must estimate the distribution of response time, or at least its tail. Exact analytic methods based on state-space analysis suffer from state explosion, and simulation, which is also feasible, is very time consuming. Rapid approximate estimation would be valuable, especially for those cases which do not demand great precision, and which require the exploration of many alternative models. This work adapts layered queueing analysis, which is highly scalable and provides variance estimates as well as mean values, to estimate soft deadline success rates. It evaluates the use of an approximate Gamma distribution fitted to the mean and variance, and its application to examples of software systems. The evaluation finds that, for a definable set of situations, the tail probabilities over 90% are estimated well within a margin of 1% accuracy, which is useful for practical purposes. Copyright 2005 ACM.
We present an automated solution for rapid diagnosis of both known and unknown 'soft-failures' in network User Devices (UDs). A multiclass classifier is first trained with the known faults and during diagnosis...
Recently, different research teams used Cellular models for the analysis of environmental systems using Cellular models. Some of these techniques are based on Cellular Automata, which have some problems constraining i...
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ISBN:
(纸本)1424308526
Recently, different research teams used Cellular models for the analysis of environmental systems using Cellular models. Some of these techniques are based on Cellular Automata, which have some problems constraining its power, usability and feasibility for studying large complex systems. In other cases, the Cellular Automata have been combined with the DEVS (Discrete-Event systems Specifications) formalism, which requires expertise in advanced programming techniques, visualization, distributed computing, etc. Instead, the Cell-DEVS formalism and the CD++ toolkit Cell-DEVS simplify the construction of complex cellular models by allowing simple and more intuitive model specification. We present the definition of different models, focusing on how to define such applications using Cell-DEVS methodology.
Rendezvous is an initial and vital process for establishing data communications between devices in cognitive radio networks. Channel hopping (CH) provides an effective method for achieving rendezvous without relying o...
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