59 research outputs found
Resource-oriented middleware abstractions for pervasive computing
No full textThe pervasive computing vision of the future communication and computational infrastructure is that we will be everywhere virtually connected with invisible computers, embedded in the environment. In this context, the challenge is to provide a middleware support that allows applications to have minimal assumptions about the environment while being able to dynamically adapt to the surrounding context. Specifically, the middleware should (i) deal with the run-time growth of the application in terms of involved resources (flexibility), (ii) accommodate heterogeneous and unforeseen functionalities into the running application (genericity), and (iii) discover new functionality at run time and rearrange the application accordingly (dynamism). To this extent, we devised the P-REST (Pervasive REST) architectural style and built the P RIME (P-rest Runtime) middleware to support it. PRIME allows a quick and effective development and execution P-REST applications by leveraging functional programming and code mobility.</p
PACE: A data-flow coordination language for asynchronous network-based applications
No full textNetwork-based applications usually rely on the explicit distribution of components, which interact by means of message passing. Assembling components into a workflow is challenging due to the asynchronism inherent to the underlying message-passing communication model. This paper presents the PaCE language, which aims at coordinating asynchronous network-based components by exploiting the data-flow execution model. Specifically, PaCE has been designed for dealing with components compliant with the P-REST architectural style for pervasive adaptive systems. Moreover PaCE provides reflective features enabling run-time adaptation and evolution of workflows.</p
Light and Matter, Two Sides of the Same Coin
No full textWith an opinionated and irreverent tone, the author debunks most of the current theories in the field of modern physics, appealing to the scientific method and common sense. At the same time, in strict compliance with the already known experimental evidence, he proposes his own version of the facts, aimed at rationalizing and unifying the various aspects in which the nature that surrounds us manifests itself. The result is a possible model of the universe where events are all connected by a common thread, even if distributed on different scales, ranging from the subatomic to that of galaxies. In this perspective, in the middle, the living cell profits from a substrate and a habitat that have favoured its very existence. Reading of this book does not require any advanced scientific knowledge and is therefore accessible to non-experts, provided they are equipped with the necessary dose of eccentricity that allows them to appreciate these provocative pages
RESTful service architectures for pervasive networking environments
No full textComputing facilities are an essential part of the fabric of our society, and an ever-increasing number of computing devices is deployed within the environment in which we live. The vision of pervasive computing is becoming real. To exploit the opportunities offered by pervasiveness, we need to revisit the classic software development methods to meet new requirements: (1) pervasive applications should be able to dynamically configure themselves, also benefiting from third-party functionalities discovered at run time and (2) pervasive applications should be aware of, and resilient to, environmental changes. In this chapter we focus on the software architecture, with the goal of facilitating both the development and the run-time adaptation of pervasive applications. More specifically we investigate the adoption of the REST architectural style to deal with pervasive environment issues. Indeed, we believe that, although REST has been introduced by observing and analyzing the structure of the Internet, its field of applicability is not restricted to it. The chapter also illustrates a proof-of-concept example, and then discusses the advantages of choosing REST over other styles in pervasive environments.</p
A decision-making machine learning approach in Hermite spectral approximations of partial differential equations
No full textThe accuracy and effectiveness of Hermite spectral methods for the numerical discretization of partial differential equations on unbounded domains are strongly affected by the amplitude of the Gaussian weight function employed to describe the approximation space. This is particularly true if the problem is under-resolved, i.e., there are no enough degrees of freedom. The issue becomes even more crucial when the equation under study is time-dependent, forcing in this way the choice of Hermite functions where the corresponding weight depends on time. In order to adapt dynamically the approximation space, it is here proposed an automatic decision-making process that relies on machine learning techniques, such as deep neural networks and support vector machines. The algorithm is numerically tested with success on a simple 1D problem, but the main goal is its exportability in the context of more serious applications. As a matter of fact we also show at the end an application in the framework of plasma physics
Architectural Issues of Adaptive Pervasive Systems
No full textPervasive systems are often made out of distributed software components that run on different computational units (appliances, sensing and actuating devices, computers). Such components are often developed, maintained, and even operated by different parties. Applications are increasingly built by dynamically discovering and composing such components in a situation-aware manner. By this we mean that applications follow some strategies to self-organize themselves to adapt their behavior depending on the changing situation in which they operate, for example the physical environment. They may also evolve autonomously in response to changing requirements. Software architectures are considered a well-suited abstraction to achieve situational adaptation. In this paper, we review some existing architectural approaches to self-adaptation and propose a high-level meta-model for architectures that supports dynamic adaptation. The meta-model is then instantiated in a specific ambient computing case study, which is used to illustrate its applicability.</p
Individual cell-based model for in-vitro mesothelial invasion of ovarian cancer
No full textIn vitro transmesothelial migration assays of ovarian cancer cells, isolated or
aggregated in multicellular spheroids, are reproduced deducing suitable Cellular Potts
Models (CPM). We show that the simulations are in good agreement with the experimental
evidence and that the overall process is regulated by the activity of matrix
metalloproteinases (MMPs) and by the interplay of the adhesive properties of the cells
with the extracellular matrix and between cells, both of the same type and of different
types. In particular, the process depends on the ability of the cell to induce the
loosening of cadherin-mediated junctions. Coherently with experiments, it is found that
single cell invasion is more conservative with a crucial role played by MMPs. A similar
important role is played in cell spheroid invasion, which in comparison is more
disruptive. It achieves monofocal or multifocal characteristics according to the relative
adhesion affinity among cells or between them and the mesothelial layer
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