39781945
Spectral decomposition approach for transient analysis of multi-server discrete-time queues
Previous work by the authors (See Proceedings Conf. on Information Sciences and Systems, Baltimore, USA, 1990) where the spectral decomposition method was used for the transient analysis of a single-server queue is generalized. For the arrival process a general discrete-time Markovian batch arrival process is assumed, where the batch size distribution of the arrivals in successive slots is governed by a N-state discrete-time Markov chain. It is shown that once the N eigenvalues of the probability generating matrix of the arrival process are obtained, the complete solution in the transform domain may be given. Using the complex analysis technique and Cauchy's integral formula, an efficient numerical method is presented for the calculation of a few performance measures. The numerical method is generalized to the situations where the superpositions of a number of independent arrival sources are fed to the queue. It is shown that the numerical complexity are fed to the queue. It is shown that the numerical complexity of obtaining the transient solution in this case can be substantially reduced by using an approach based on the Kronecker product.<<ETX>>
19257985
Proactive care-of address test for route optimization in FMIPv6
This paper proposes a practical scheme to run the care-of address test (part of the Return Routability test for Mobile IPv6 route optimization) in a proactive way in the context of the Fast Handovers for Mobile IPv6 (FMIPv6) protocol, so that the latency (normally one round-trip time between a mobile node and its correspondent node) caused by the care-of address test after movements can be removed or reduced. Proactive care-of address test can make the Return Rroutability protocol more suitable for delay sensitive applications especially when it is applied in conjunction with other Return Routability optimization schemes.
20173388
Spectral Decomposition Approach for Transient Analysis of Multi-Server Discrete-Time Queues
Abstract Discrete time queueing systems are extensively used in modeling the ATM environment at the cell level. This paper examines the transient behavior of a discrete time FCFS multiple server queue. For the arrival process we assume a general discrete time Markovian batch arrival process, where the batch size distribution of the arrivals in successive slots is governed by a finite state discrete time Markov chain. We show that once the spectral decomposition of the “probability generating matrix” of the arrival process is obtained, the complete solution in the transform domain may be given. Using the complex analysis technique and Cauchy's integral formula, we present an efficient numerical method for the numerical calculation of a few performance measures of interest, namely transient probability of queue being empty, and the mean of the queue length distribution. We also generalize our numerical method in the situations where the superposition of a number of independent arrival sources are fed to the queue. It is shown that the numerical complexity of obtaining the transient solution in this case can be substantially reduced by using the approach based on the Kronecker product. The finite buffer case is also analyzed.
24760638
Performance study of Markov modulated fluid flow models with priority traffic
The steady-state performance of generic high-speed queuing system with priority traffic is studied, using the Markov modulated fluid models. the focus is on systems with traffic partitioned into two priorities according to a splitting factor alpha , so that low priority traffic can be discarded when congestion occurs. The results are used to further study issues of congestion control with priority traffic. In particular, the expected values, waiting times, variances of the buffer contents, and tail distributions are evaluated. It is found that the waiting time is more sensitive to changes of alpha than the buffer contents. This shows that for time-constrained traffic, the priority assignment is important for properly balancing the tradeoff between packet loss and delays. This model can be considered as a direct extension of the fluid-flow model to include priorities.<<ETX>>
42486395
On a class of Banyan networks and tandem Banyan switching fabrics
The operating characteristics of a class of tandem banyan switching fabrics (TBSFs) built using bi-delta networks are examined. Functional equivalence between bi-delta networks induces an equivalence between TBSFs as well. A weaker form of equivalence guaranteeing identical performance under the conditions of symmetric traffic is studied, and sufficient conditions for weak equivalent between functionally distinct TBSFs is established. These results hold for a variety of conflict resolution policies (CRPs). Simulations indicate that a TBSF constructed by cascading omega networks (or in fact any other TBSF in its weak equivalence class) performs better than the two TBSFs studied by F.A. Tobagi et al. (1991) and converges rapidly to a theoretical lower bound on the loss rate in the region of interest.<<ETX>>
5054397
The transient solution of time-dependent M/M/1 queues
The transient behavior of time-dependent M/M/1 queues is studied. The boundary probability function pi /sub 0/(t), which is the probability that the queue is empty at time t, is shown with analyticity arguments to satisfy a Volterra-type integral equation. The boundary integral equation is derived, and a numerical algorithm is used to solve the integral equation and to find the expected queue size from pi /sub 0/(t). The approach can be applied to many other types of time-dependent queues. Examples are given. >
31337744
Information Strategies to Support Full Information Product Pricing: the Role of Trust
In this paper, we report the importance of trust in the development and operation of distribution networks that attach non-price information to products to mitigate market dynamics introduced by information asymmetries. Often this non-price information is transmitted from producers to consumers through trusting networks or under certifiable labels such as Organic or Fair Trade. We are calling such networks Full Information Product Pricing (FIPP) Networks. This study is part of a larger project aimed at understanding the characteristics of FIPP networks. This initial exploration on four cases in Canada and Latin America indicated that trust, in the forms of institutional trust, calculative trust, and relational trust, plays key roles in FIPP operations and expansion. It is critical for building collaboration, coordinating network activities, and mitigating the risks associated with information asymmetry.
18289279
A Simplified Learning Algorithm of Incremental Bayesian
A proportion factor is constructed though the Maximum Aposteriori Probability of examples in test data to select the training examples in incremental learning process. Instead of complex normal classify loss expression, the proportion factor λ is used to estimate the classify loss to improve classification efficiency. The final experiment shows that this algorithm is feasible, and more accurate than simple Bayesian classifier. The computing time is highly reduced on the optimal selection of examples in incremental learning process.
25041891
An Advanced Scheme For Wireless Network Authentication System
In this paper we use the independent component analysis (ICA) and Factorial Face Code as an additional user identity checking method to strengthen the solidity of the wireless application system authentication security. The basic theory of ICA and factorial face code are presented firstly and then the main works of this method are detailed. After that an experiment based on this method is given. According to this experiment, we know that this method can confirm user’s identity and can be an additional method to check wireless application system user identity. In order to improve the affectivity of this method, we should increase the mount of image data in the face database, getting more ICs and enlarging the size of the basic images set. All this will increase the length of the factorial face code, and subsequently will differentiate one person from another more easily.
18478421
An Efficient Approach for Service Process Reconfiguration in SOA with End-to-End QoS Constraints
Using SOA, service processes can be composed statically or dynamically using services provided by different service providers. Some services may become faulty at runtime and cause the service process to violate the end-to-end quality of service (QoS) constraint. We propose an efficient approach for replacing faulty services to ensure that the reconfigured service process still meets the original end-to-end QoS constraint. We use an iterative algorithm to identify reconfiguration regions that have a small number of services, some faulty and some healthy, in order to have more service selection options. By reconfiguring services in these selected regions rather than the whole service process, the computational complexity is significantly reduced. Simulation study has shown that our approach is efficient as most service processes can be repaired by replacing only a small number of services.
46405724
A Novel Approach Using PCA and SVM for Face Detection
Nowadays, face detection and recognition have gained importance in security and information access. In this paper, an efficient method of face detection based on principal components analysis (PCA) and support vector machine (SVM) is proposed. It firsly filter the face potential area using statistical feature which is generated by analyzing local histogram distribution. And then, SVM classifier is used to detect face feature in the test image, SVM has great performance in classification task. PCA is used to reduce dimension of sample data. After PCA transform, the feature vectors, which are used for training SVM classifier, are generated. Our tests in this paper are based on CMU face database. The experimental results demonstrate that the proposed method is encouraging with a successful detection rate.