935 research outputs found
Networking - A Statistical Physics Perspective
Efficient networking has a substantial economic and societal impact in a
broad range of areas including transportation systems, wired and wireless
communications and a range of Internet applications. As transportation and
communication networks become increasingly more complex, the ever increasing
demand for congestion control, higher traffic capacity, quality of service,
robustness and reduced energy consumption require new tools and methods to meet
these conflicting requirements. The new methodology should serve for gaining
better understanding of the properties of networking systems at the macroscopic
level, as well as for the development of new principled optimization and
management algorithms at the microscopic level. Methods of statistical physics
seem best placed to provide new approaches as they have been developed
specifically to deal with non-linear large scale systems. This paper aims at
presenting an overview of tools and methods that have been developed within the
statistical physics community and that can be readily applied to address the
emerging problems in networking. These include diffusion processes, methods
from disordered systems and polymer physics, probabilistic inference, which
have direct relevance to network routing, file and frequency distribution, the
exploration of network structures and vulnerability, and various other
practical networking applications.Comment: (Review article) 71 pages, 14 figure
Analysing the visual dynamics of spatial morphology
Recently there has been a revival of interest in visibility analysis of architectural configurations. The new analyses rely heavily on computing power and statistical analysis, two factors which, according to the postpositivist school of geography, should immediately cause us to be wary. Thedanger, they would suggest, is in the application of a reductionist formal mathematical description in order to `explain' multilayered sociospatial phenomena. The author presents an attempt to rationalise how we can use visibility analysis to explore architecture in this multilayered context by considering the dynamics that lead to the visual experience. In particular, it is recommended that we assess the visualprocess of inhabitation, rather than assess the visibility in vacuo. In order to investigate the possibilities and limitations of the methodology, an urban environment is analysed by means of an agent-based model of visual actors within the configuration. The results obtained from the model are compared with actual pedestrian movement and other analytic measurements of the area: the agents correlate well both with human movement patterns and with configurational relationship as analysed by space-syntax methods. The application of both methods in combination improves on the correlation with observed movement of either, which in turn implies that an understanding of both the process of inhabitation and the principles of configuration may play a crucial role in determining the social usage of space
Application-based COVID-19 micro-mobility solution for safe and smart navigation in pandemics
Short distance travel and commute being inevitable, safe route planning in pandemics for micro-mobility, i.e., cycling and walking, is extremely important for the safety of oneself and others. Hence, we propose an application-based solution using COVID-19 occurrence data and a multi-criteria route planning technique for cyclists and pedestrians. This study aims at objectively determining the routes based on various criteria on COVID-19 safety of a given route while keeping the user away from potential COVID-19 transmission spots. The vulnerable spots include places such as a hospital or medical zones, contained residential areas, and roads with a high connectivity and influx of people. The proposed algorithm returns a multi-criteria route modeled on COVID-19-modified parameters of micro-mobility and betweenness centrality considering COVID-19 avoidance as well as the shortest available safe route for user ease and shortened time of outside environment exposure. We verified our routing algorithm in a part of Delhi, India, by visualizing containment zones and medical establishments. The results with COVID-19 data analysis and route planning suggest a safer route in the context of the coronavirus outbreak as compared to normal navigation and on average route extension is within 8%â12%. Moreover, for further advancement and post-COVID-19 era, we discuss the need for adding open data policy and the spatial system architecture for data usage, as a part of a pandemic strategy. The study contributes new micro-mobility parameters adapted for COVID-19 and policy guidelines based on aggregated contact tracing data analysis maintaining privacy, security, and anonymity
Research and Education in Computational Science and Engineering
Over the past two decades the field of computational science and engineering
(CSE) has penetrated both basic and applied research in academia, industry, and
laboratories to advance discovery, optimize systems, support decision-makers,
and educate the scientific and engineering workforce. Informed by centuries of
theory and experiment, CSE performs computational experiments to answer
questions that neither theory nor experiment alone is equipped to answer. CSE
provides scientists and engineers of all persuasions with algorithmic
inventions and software systems that transcend disciplines and scales. Carried
on a wave of digital technology, CSE brings the power of parallelism to bear on
troves of data. Mathematics-based advanced computing has become a prevalent
means of discovery and innovation in essentially all areas of science,
engineering, technology, and society; and the CSE community is at the core of
this transformation. However, a combination of disruptive
developments---including the architectural complexity of extreme-scale
computing, the data revolution that engulfs the planet, and the specialization
required to follow the applications to new frontiers---is redefining the scope
and reach of the CSE endeavor. This report describes the rapid expansion of CSE
and the challenges to sustaining its bold advances. The report also presents
strategies and directions for CSE research and education for the next decade.Comment: Major revision, to appear in SIAM Revie
The Law of Blockchain
Blockchain technology is a new general-purpose technology that poses significant challenges to the existing state of law, economy, and society. Blockchain has one feature that makes it even more distinctive than other disruptive technologies: it is, by nature and design, global and transnational. Moreover, blockchain operates based on its own rules and principles that have a law-like quality. What may be called the lex cryptographia of blockchain has been designed based on a rational choice vision of human behavior. Blockchain adopts a framing derived from neoclassical economics, and instantiates it in a new machinery that implements rational choice paradigms using blockchain in a semi-automatic way, across all spheres of life, and without regard to borders. Accordingly, a global law and crypto-economics movement is now emerging owing to the spread of blockchain.
This Article suggests that such a rational choice paradigm is an insufficient foundation for the future development of blockchain. It seeks to develop a new understanding of blockchain and its regulation through code according to the emerging âlaw and political economyâ framework. Blockchain is much more than a machine that enables the automation of transactions according to a rational choice framework. Blockchain should instead be understood as a technological infrastructure. Acknowledging the infrastructural dimension of blockchain technology may help identify a new role for the law in its interaction with blockchain, as well as for government in its interaction with the new technology. More precisely, identifying blockchain as an âinfrastructural commonsâ helps us recognize that law and regulation should not be relegated to the role of merely facilitating the operation of the invisible hand of the market by and within blockchain, but should rather acquire more active roles, such as safeguarding access on non-discriminatory terms to users, on a model with net neutrality and other public utility safeguards. The Article closes by proposing a âlaw and political economyâ framework for blockchain that is based on principles of publicness, trust, and interoperability
The Digital Spatial Fix
This article brings distinct strands of the political economy of communication and economic geography together in order to theorise the role digital technologies play in Marxian crisis theory. Capitalist advances into digital spaces do not make the law of value obsolete, but these spaces do offer new methods for displacing overaccumulated capital, increasing consumption, or accumulating new, cheaper labour. We build on David Harveyâs theory of the spatial fix to describe three digital spatial fixes, fixed capital projects that use the specific properties of digital spaces to increase the rate of profit, before themselves becoming obstacles to the addictive cycle of accumulation: the primitive accumulation of time in the social Web, the annihilation of time by space in high-frequency trading, and affect rent in virtual worlds. We conclude by reflecting on how these digital spatial fixes also fix the tempo of accumulation and adjust the time-scale of Marxian crisis theory
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