39,493 research outputs found

    A Generic Model of Contracts for Embedded Systems

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    We present the mathematical foundations of the contract-based model developed in the framework of the SPEEDS project. SPEEDS aims at developing methods and tools to support "speculative design", a design methodology in which distributed designers develop different aspects of the overall system, in a concurrent but controlled way. Our generic mathematical model of contract supports this style of development. This is achieved by focusing on behaviors, by supporting the notion of "rich component" where diverse (functional and non-functional) aspects of the system can be considered and combined, by representing rich components via their set of associated contracts, and by formalizing the whole process of component composition

    Contract Aware Components, 10 years after

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    The notion of contract aware components has been published roughly ten years ago and is now becoming mainstream in several fields where the usage of software components is seen as critical. The goal of this paper is to survey domains such as Embedded Systems or Service Oriented Architecture where the notion of contract aware components has been influential. For each of these domains we briefly describe what has been done with this idea and we discuss the remaining challenges.Comment: In Proceedings WCSI 2010, arXiv:1010.233

    Do capital flows respond to risk and return?

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    This paper explores empirically the role of risk and return in the observed evolution of net foreign asset positions of industrial and developing economies. The paper adopts a dynamic approach in which investors'portfolios adjust gradually to their long-run equilibrium, defined by a standard Tobin-Markowitz framework. The parameters characterizing the long-run equilibrium are estimated using data on foreign assets and liabilities of a large number of industrial and developing countries spanning the period from 1965 to 1997. The paper employs a dynamic panel estimation procedure allowing for unrestricted short-run heterogeneity across countries, using the pooled mean group estimator recently developed by Pesaran, Shin, and Smith (1999). The empirical results lend considerable support to the model when applied to countries with low capital controls and/or high and upper-middle income. The results for countries with either high capital controls or low per capita income are less supportive of the stock equilibrium model for net foreign asset positions.Economic Theory&Research,Payment Systems&Infrastructure,International Terrorism&Counterterrorism,Fiscal&Monetary Policy,Environmental Economics&Policies,Economic Theory&Research,International Terrorism&Counterterrorism,Environmental Economics&Policies,Health Economics&Finance,Banks&Banking Reform

    Controllability of structural brain networks.

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    Cognitive function is driven by dynamic interactions between large-scale neural circuits or networks, enabling behaviour. However, fundamental principles constraining these dynamic network processes have remained elusive. Here we use tools from control and network theories to offer a mechanistic explanation for how the brain moves between cognitive states drawn from the network organization of white matter microstructure. Our results suggest that densely connected areas, particularly in the default mode system, facilitate the movement of the brain to many easily reachable states. Weakly connected areas, particularly in cognitive control systems, facilitate the movement of the brain to difficult-to-reach states. Areas located on the boundary between network communities, particularly in attentional control systems, facilitate the integration or segregation of diverse cognitive systems. Our results suggest that structural network differences between cognitive circuits dictate their distinct roles in controlling trajectories of brain network function

    Internet of things

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    Manual of Digital Earth / Editors: Huadong Guo, Michael F. Goodchild, Alessandro Annoni .- Springer, 2020 .- ISBN: 978-981-32-9915-3Digital Earth was born with the aim of replicating the real world within the digital world. Many efforts have been made to observe and sense the Earth, both from space (remote sensing) and by using in situ sensors. Focusing on the latter, advances in Digital Earth have established vital bridges to exploit these sensors and their networks by taking location as a key element. The current era of connectivity envisions that everything is connected to everything. The concept of the Internet of Things(IoT)emergedasaholisticproposaltoenableanecosystemofvaried,heterogeneous networked objects and devices to speak to and interact with each other. To make the IoT ecosystem a reality, it is necessary to understand the electronic components, communication protocols, real-time analysis techniques, and the location of the objects and devices. The IoT ecosystem and the Digital Earth (DE) jointly form interrelated infrastructures for addressing today’s pressing issues and complex challenges. In this chapter, we explore the synergies and frictions in establishing an efficient and permanent collaboration between the two infrastructures, in order to adequately address multidisciplinary and increasingly complex real-world problems. Although there are still some pending issues, the identified synergies generate optimism for a true collaboration between the Internet of Things and the Digital Earth

    Does wage rank affect employees' well-being?

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    How do workers make wage comparisons? Both an experimental study and an analysis of 16,000 British employees are reported. Satisfaction and well-being levels are shown to depend on more than simple relative pay. They depend upon the ordinal rank of an individual's wage within a comparison group. “Rank” itself thus seems to matter to human beings. Moreover, consistent with psychological theory, quits in a workplace are correlated with pay distribution skewness

    Spatial Economic Analysis in Data-Rich Environments

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    Controlling for spatial effects in micro-economic studies of consumer and producer behavior necessitates a range of analytical modifications ranging from modest changes in data collection and the definition of variables to dramatic changes in the modeling of consumer and producer decision-making. This paper discusses conceptual, empirical, and data issues involved in modeling the spatial aspects of economic behavior in data rich environments. Attention is given to established and emerging agricultural economic applications of spatial data and spatial econometric methods at the micro-scale. Recent applications of individual and household data are featured, including models of land-use change at the urban-rural interface, agricultural land values, and technological change and technology adoption.Research Methods/ Statistical Methods, C21, Q10, Q12, Q15, Q56,

    Aquaculture systems modeling: an introduction with emphasis on warmwater aquaculture

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    An introduction to modeling is presented. The basic concepts of systems and models and various types of models and their use in research and in management are described. Guidelines for modeling aquaculture systems are presented: empirical models for the analysis of multivariate datasets and theoretical models based on knowledge of the various processes underlying a system. Examples of two modeling approaches to the production of Nile tilapia (Oreochromis niloticus) in ricefields are given in an appendix.Aquaculture systems, Warm-water aquaculture, Modelling
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