Analyzing Temperature Effects on Mortality Within the R Environment: The Constrained Segmented Distributed Lag Parameterization

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.

Design and Fabrication of Components with Optimized Lattice Microstructures

The design and fabrication of components with optimized lattice microstructures is a new approach to creating lightweight high-performance objects. This paper introduces a unique and complete integration of design and fabrication leading to the creation of structural components with complex composite microstructures. Rather than a solid cast component with optimized outer shape this new approach leads to a component with an inner skeleton or microstructure maximizing one or more properties such as the stiffness-to-weight ratio. Three dimensional gradient materials are a natural outcome of this approach. An introduction to the design optimization and hybrid fabrication approach will be provided in addition to research progress and challenges through Spring 2004.Mechanical Engineerin

Geometry and Procedure for Benchmarking SFF and Hybrid Fabrication Process Resolution

Since the advent of SFF and RP a number of SFF benchmarking geometries and methodologies have been developed and employed with some similarities but limited standardization. Minimal information has been published in regard to a standard method of measuring the resolution limits or capabilities of SFF and SFF-based hybrid processes. In an effort to benchmark resolution limits of SFF and Hybrid Fabrication processes, several benchmarking geometries were developed to capture the resolution capabilities, specifically hole size and rod size range, of multiple hybrid fabrication path steps and a hybrid path as a whole. These useful geometries are shared with the SFF community and procedures for their use are described in this paper.Mechanical Engineerin

Statistical Process Control For Solid Freeform Fabrication Processes

Statistical prpcess control (SPC) has not been widely used for solid freeform fabrication (SFF) pr~cesses, primarily due to the wide diversity ofgeometries in builds. In addition, typical parts created on SFF platforms are not ofsimple, nor easy-to- measure geometries, which fVrther complicates the application ofSPC. A study is currently in progress to establisq a method to apply SPC to SFF. Three SPC test parts were studied to determine the addedIbuild cost and accuracy improvement when SPC is applied to stereolithography. In this study, SPC was applied to X & Y shrinkage, and line-widthcompensation facto~s over a period oftime. IfSPC can be effectively applied, it will alert the operator to othe~seunnoticed system changes before valuable build-time is lost.Mechanical Engineerin

Vulnerability and Protection of Critical Infrastructures

Critical infrastructure networks are a key ingredient of modern society. We discuss a general method to spot the critical components of a critical infrastructure network, i.e. the nodes and the links fundamental to the perfect functioning of the network. Such nodes, and not the most connected ones, are the targets to protect from terrorist attacks. The method, used as an improvement analysis, can also help to better shape a planned expansion of the network.Comment: 4 pages, 1 figure, 3 table

Analyzing Temperature Effects on Mortality Within the R Environment: The Constrained Segmented Distributed Lag Parameterization

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

Entropy Rate of Diffusion Processes on Complex Networks

The concept of entropy rate for a dynamical process on a graph is introduced. We study diffusion processes where the node degrees are used as a local information by the random walkers. We describe analitically and numerically how the degree heterogeneity and correlations affect the diffusion entropy rate. In addition, the entropy rate is used to characterize complex networks from the real world. Our results point out how to design optimal diffusion processes that maximize the entropy for a given network structure, providing a new theoretical tool with applications to social, technological and communication networks.Comment: 4 pages (APS format), 3 figures, 1 tabl

Dynamical organization towards consensus in the Axelrod model on complex networks

We analyze the dynamics toward cultural consensus in the Axelrod model on scale-free networks. By looking at the microscopic dynamics of the model, we are able to show how culture traits spread across different cultural features. We compare the diffusion at the level of cultural features to the growth of cultural consensus at the global level, finding important differences between these two processes. In particular, we show that even when most of the cultural features have reached macroscopic consensus, there are still no signals of globalization. Finally, we analyze the topology of consensus clusters both for global culture and at the feature level of representation.Comment: 8 pages, 7 figures. Final version published in Physical Review