9,403 research outputs found
Digital Ecosystems: Ecosystem-Oriented Architectures
We view Digital Ecosystems to be the digital counterparts of biological
ecosystems. Here, we are concerned with the creation of these Digital
Ecosystems, exploiting the self-organising properties of biological ecosystems
to evolve high-level software applications. Therefore, we created the Digital
Ecosystem, a novel optimisation technique inspired by biological ecosystems,
where the optimisation works at two levels: a first optimisation, migration of
agents which are distributed in a decentralised peer-to-peer network, operating
continuously in time; this process feeds a second optimisation based on
evolutionary computing that operates locally on single peers and is aimed at
finding solutions to satisfy locally relevant constraints. The Digital
Ecosystem was then measured experimentally through simulations, with measures
originating from theoretical ecology, evaluating its likeness to biological
ecosystems. This included its responsiveness to requests for applications from
the user base, as a measure of the ecological succession (ecosystem maturity).
Overall, we have advanced the understanding of Digital Ecosystems, creating
Ecosystem-Oriented Architectures where the word ecosystem is more than just a
metaphor.Comment: 39 pages, 26 figures, journa
New Electricity Technologies for a Sustainable Future
There is a growing concern over our reliance on conventional electricity sources and their long-term environmental, climate change, and security of supply implications, and much hope is vested in the ability of future technological progress to tackle these issues. However, informed academic analysis and policy debates on the future of electricity systems must be based on the current state, and prospects of, technological options. This paper is the introductory chapter in the forthcoming book Future Electricity Technologies and Systems. The book comprises contributions from leading experts in their respective technology areas. The chapters present state of the art and likely progress paths of conventional and new electricity generation, networks, storage, and end-use technologies. In this paper we review the growth trend in electricity demand and carbon emissions. We then present a concise overview of the chapters. Finally, we discuss the main contextual factors that influence long-term technological progress
Realizing stock market crashes: stochastic cusp catastrophe model of returns under the time-varying volatility
This paper develops a two-step estimation methodology, which allows us to
apply catastrophe theory to stock market returns with time-varying volatility
and model stock market crashes. Utilizing high frequency data, we estimate the
daily realized volatility from the returns in the first step and use stochastic
cusp catastrophe on data normalized by the estimated volatility in the second
step to study possible discontinuities in markets. We support our methodology
by simulations where we also discuss the importance of stochastic noise and
volatility in deterministic cusp catastrophe model. The methodology is
empirically tested on almost 27 years of U.S. stock market evolution covering
several important recessions and crisis periods. Due to the very long sample
period we also develop a rolling estimation approach and we find that while in
the first half of the period stock markets showed marks of bifurcations, in the
second half catastrophe theory was not able to confirm this behavior. Results
suggest that the proposed methodology provides an important shift in
application of catastrophe theory to stock markets
Computational entrepreneurship: from economic complexities to interdisciplinary research
The development of technology is unbelievably rapid. From limited local networks to high speed Internet, from crude computing machines to powerful semi-conductors, the world had changed drastically compared to just a few decades ago. In the constantly renewing process of adapting to such an unnaturally high-entropy setting, innovations as well as entirely new concepts, were often born. In the business world, one such phenomenon was the creation of a new type of entrepreneurship. This paper proposes a new academic discipline of computational entrepreneurship, which centers on: (i) an exponentially growing (and less expensive) computing power, to the extent that almost everybody in a modern society can own and use that; (ii) omnipresent high-speed Internet connectivity, wired or wireless, representing our modern day’s economic connectomics; (iii) growing concern of exploiting “serendipity” for a strategic commercial advantage; and (iv) growing capabilities of lay people in performing calculations for their informed decisions in taking fast-moving entrepreneurial opportunities. Computational entrepreneurship has slowly become a new mode of operation for business ventures and will likely bring the academic discipline of entrepreneurship back to mainstream economics
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