Search results for "Abstraction"

First-Order Calculus on Metric Measure Spaces

2020

In this chapter we develop a first-order differential structure on general metric measure spaces. First of all, the key notion of cotangent module is obtained by combining the Sobolev calculus (discussed in Chap. 2) with the theory of normed modules (described in Chap. 3). The elements of the cotangent module L2(T∗X), which are defined and studied in Sect. 4.1, provide a convenient abstraction of the concept of ‘1-form on a Riemannian manifold’.

1976

tert-Butoxy radicals were generated by decomposing di-tert-butyl hyponitrite. The relative reactivities of substrates were measured from the ratio of tert-butanol and acetone formed. Polystyrene was found to be less reactive than model compounds. Activation parameters for the hydrogen abstraction reaction for cumene, 3-phenylpentane, and 2,4-diphenylpentane are reported and show small differences for the enthalpy of activation; large negative values for the entropy of activation demonstrate the importance of steric hindrance in the hydrogen abstracting step. 2,3-Diphenylbutane as model compound for head to head links in polystyrene exhibits low reactivity, whereas 2,5-diphenylhexane, a mode…

What Is Synthetic Biology?

2014

Synthetic biology aims at the design and construction of biological devices and systems for useful purposes. From an ideal engineering perspective synthetic biology works from rational design made through a few conceptual pillars, namely abstraction, standardization and modularity. Nevertheless, the combination of our still fragmentary biological knowledge and the messy nature of biological devices are major challenges for engineering life in a predictive manner. It is urgent to build bridges between different disciplines, from biology to engineer and back, to pursue this extraordinary goal of making life.

Pitfalls in the Development of Agent-Based Models in Social Sciences: Avoiding Them and Learning from Them

2019

The references on the principles and methodology for developing agent-based models of social phenomena usually describe general principles and illustrate the process using worked examples, but seldom focus on the pitfalls and errors that make practical model building a tortuous and difficult task. This chapter contains a discussion of the positive and negative aspects of my personal experience in a PhD work on simulation of large scale social conflict. The purpose will be to describe the process from the initial plan to the final dissertation, analyze the pitfalls and their overcoming in terms of principles of model development, and summarize the ideas that I found useful for practical deve…

Abstraction in Motion

2015

Folding Pattern is an art project developed by the team of artists, Cristina Ghetti and Emanuele Mazza. The work starts from the idea of proposing a revision of the foundations of perceptual abstraction, that had in it's derivations, one of the art movements more connected with the use of new technologies and one of the art tendencies with more powerful and interesting arguments. We are interested in exploring the developments of abstraction in the digital era, incorporating new media tools, and analyzing how contemporary art is developing the ideas of modernist abstraction introducing the utilization of new technologies, in a context where the influence of science, and of new ways of produ…

A Lightweight Network Discovery Algorithm for Resource-constrained IoT Devices

2019

Although quite simple, existing protocols for the IoT suffer from the inflexibility of centralized infrastructures and require several configuration stages. The implementation of these protocols is often prohibitive on resource-constrained devices. In this work, we propose a distributed lightweight implementation of network discovery for simple IoT devices. Our approach is based on the exchange of symbolic executable code among nodes. Based on this abstraction, we propose an algorithm that makes even IoT resource-constrained nodes able to construct the network topology graph incrementally and without any a priori information about device positioning and presence. The minimal set of executab…

A Models-to-Program Information Systems Engineering Method

2021

The Model-Driven Development paradigm aims to represent all the information system features through models. Conceptual-Model Programming offers a similar approach, but with a focus on automatic code generation. Both approaches consider modeling and traceability of different abstraction levels, where each level can be tackled with different modeling methods. This heterogeneity introduces a challenge for the quality of the traceability and transformations among models, especially when aiming for automatic code generation. In this paper, we introduce a holistic conceptual-model programming method to generate code from different abstraction levels (from the problem space to the solution space),…

Photo Induced Radical Reactions

2012

This article discusses a number of reactions of potential synthetic interest occurring through photochemically generated organic radicals. Emphasis is placed on the nature of the resulting photoproducts, whose formation is discussed on a mechanistic basis. If available, experimental evidence (obtained by laser flash photolysis or related time-resolved techniques) is provided. The material is organized according to the reaction types, for instance, homolytic cleavage, mesolytic cleavage, radical addition, and oxidative or reductive electron transfer. In addition to the classical carboncarbon or carbonhydrogen bond breaking processes, such as the Norrish type I reaction, the hydrogen abstract…

Have Fun with Math and Music!

2019

If abstraction makes mathematics strong, it often makes it also hard to learn, if not discouraging. If math pedagogy suffers from the lack of engaging strategies, the pedagogy of mathematical music theory must deal with the additional difficulty of double fields and double vocabulary. However, games and interdisciplinary references in a STEAM framework can help the learner break down complex concepts into essential ideas, and gain interest and motivation to approach advanced topics. Here we present some general considerations, followed by two examples which may be applied in a high-school or early college level course. The first is a musical application of a Rubik’s cube, the CubeHarmonic, …

So the Horizon Line Vanishes': Landscape and Abstraction in England from the 1930s to the 1950s

2010

This paper explores the tension between abstraction and figuration in English landscape painting from the 1930s to the 1950s, a transitional period marked by opposition between these two semiotic systems. The tension between tradition and new departure runs through the paintings and texts by John Piper and Peter Lanyon.