Search results for "Tribute"
showing 10 items of 1455 documents
A service-oriented routing scheme with load balancing in wireless mesh networks
2008
Wireless mesh networks will play an important role in the next-generation wireless communication systems as it can provide wide coverage and scalable broadband Internet access services. However, congestion in such networks may lead to throughput degradation, packet loss and longer transmission delay. Therefore, routing and traffic forwarding schemes which are aware of the congestion status of a wireless network can efficiently improve network performance. In this paper, we propose a new congestion-aware routing scheme which may direct different paths for different services types, according to network congestion status. The goal of this routing scheme is to use traffic load metric for choosi…
An Efficient Implementation of Distributed Routing Algorithms for NoCs
2008
The design of NoCs for multi-core chips introduces new design constraints like power consumption, area, and ultra low latencies. Although 2D meshes are preferred, heterogeneous blocks, fabrication faults, reliability issues, and chip virtualization may lead to the need of irregular topologies or regions. In this situation, efficient routing becomes a challenge. Although the use of routing tables at switches is flexible, it does not scale in terms of latency and area due to its memory requirements. LBDR (logic-based distributed routing) is proposed as a new routing method that removes the need of using routing tables at all. LBDR enables the implementation of many routing algorithms on most …
Applications of the vehicle routing problem with trailers and transshipments
2013
Abstract The vehicle routing problem with trailers and transshipments (VRPTT) is a recent and challenging extension of the well-known vehicle routing problem. The VRPTT constitutes an archetypal representative of the class of vehicle routing problems with multiple synchronization constraints (VRPMSs). In addition to the usual task covering constraints, VRPMSs require further synchronization between vehicles, concerning spatial, temporal, and load aspects. VRPMSs possess considerable practical relevance, but limited coverage in the scientific literature. The purpose of the present paper is to describe how several important types of VRPMSs, such as multi-echelon location-routing problems and …
Circuit-Elimination based Link-State Routing in Mobile Ad-hoc Networks
2007
Circuit-elimination based connected dominating set formation is an efficient technique for reducing routing overhead in mobile ad hoc networks. In this paper, we propose a new message dissemination algorithm which utilizes such techniques to reduce the number of nodes that generate or forward link state advertisements in link state routing protocols. Simulation results with both static and dynamic network topologies demonstrate the potential of the proposed algorithm to reduce routing overhead, compared with a benchmark link state routing protocol, OLSR.
A Unified Approach to Likelihood Inference on Stochastic Orderings in a Nonparametric Context
1998
Abstract For data in a two-way contingency table with ordered margins, we consider various hypotheses of stochastic orders among the conditional distributions considered by rows and show that each is equivalent to requiring that an invertible transformation of the vectors of conditional row probabilities satisfies an appropriate set of linear inequalities. This leads to the construction of a general algorithm for maximum likelihood estimation under multinomial sampling and provides a simple framework for deriving the asymptotic distribution of log-likelihood ratio tests. The usual stochastic ordering and the so called uniform and likelihood ratio orderings are considered as special cases. I…
The History of ViSta: The Visual Statistics System
2012
ViSta is a project that focuses on dynamic and interactive graphics for statistics and was initiated by the late Forrest W. Young at the beginning of the 1990s. For over approximately 20 years, Forrest and other collaborators, including the authors of this article, have used ViSta for experimenting with these kinds of graphics in different settings, applying them to different scenarios of data and statistical analysis, searching to develop the right combination of features most appropriate in each case. In this time, ViSta evolved quite considerably, going through what we reckon were three different stages, namely: the initial one setting forth the foundations of ViSta; the second period wh…
Modeling temperature effects on mortality: multiple segmented relationships with common break points.
2008
We present a model for estimation of temperature effects on mortality that is able to capture jointly the typical features of every temperature-death relationship, that is, nonlinearity and delayed effect of cold and heat over a few days. Using a segmented approximation along with a doubly penalized spline-based distributed lag parameterization, estimates and relevant standard errors of the cold- and heat-related risks and the heat tolerance are provided. The model is applied to data from Milano, Italy.
Analyzing Temperature Effects on Mortality Within theREnvironment: The Constrained Segmented Distributed Lag Parameterization
2010
Here we present and discuss the R package modTempEff including a set of functions aimed at modelling temperature effects on mortality with time series data. The functions fit a particular log linear model which allows to capture the two main features of mortality- temperature relationships: nonlinearity and distributed lag effect. Penalized splines and segmented regression constitute the core of the modelling framework. We briefly review the model and illustrate the functions throughout a simulated dataset.
A heuristic method for estimating attribute importance by measuring choice time in a ranking task
2012
The evaluation of a product or service in terms of its attributes has been broadly studied in marketing, management and decision sciences. However, methods for finding important attributes have theoretical and practical limitations. The former are related to the selection of the most appropriate model; the latter are due to large number of variables that affect the specific experimental context. This study aims to present a new methodology that captures attribute preferences from a respondent and in particular, by using the choice time in a ranking task, it allows to indirectly obtain the importance weights for several tested attributes through a simple, fast and inexpensive procedure. More…
Modeling and predicting the Spanish Bachillerato academic results over the next few years using a random network model
2016
[EN] Academic performance is a concern of paramount importance in Spain, where around of 30% of the students in the last two courses in high school, before to access to the labor market or to the university, do not achieve the minimum knowledge required according to the Spanish educational law in force. In order to analyze this problem, we propose a random network model to study the dynamics of the academic performance in Spain. Our approach is based on the idea that both, good and bad study habits, are a mixture of personal decisions and influence of classmates. Moreover, in order to consider the uncertainty in the estimation of model parameters, we perform a lot of simulations taking as t…