Search results for "general [Ray burst]"
showing 10 items of 6429 documents
Remembering an Era: Roger Penrose’s Paper on “Gravitational Collapse: The Role of General Relativity”
2018
Back in the 1960s, Einstein’s theory of general relativity re-emerged as a field of important research activity. Much of the impetus behind this resurgence came from powerful new mathematical ideas that Roger Penrose and Stephen Hawking applied to prove general singularity theorems for global space-time structures. Their results stirred the imaginations of astrophysicists and gave relativistic cosmology an entirely new research agenda. A decade later, black holes and the big hang model were on the tongues of nearly everyone who followed recent trends in science. As popular expositions dealing with quasars, pulsars, and the geometry of black holes began to appear in magazines and textbooks, …
Noether’s International School in Modern Algebra
2020
Pavel Alexandrov and Heinz Hopf met for the first time in Gottingen in the spring of 1926, soon after Alexandrov departed from Blaricum. Hopf had recently taken his doctorate in Berlin under Ludwig Bieberbach and Erhard Schmidt, and his research interests differed sharply from Alexandrov’s work in general topology.
Anomaly-free scale symmetry and gravity
2023
In this Letter, we address the question of whether the conformal invariance can be considered as a global symmetry of a theory of fundamental interactions. To describe Nature, this theory must contain a mechanism of spontaneous breaking of the scale symmetry. Besides that, the fundamental theory must include gravity, whereas all known extensions of the conformal invariance to the curved space-time suffer from the Weyl anomaly. We show that conformal symmetry can be made free from the quantum anomaly only in the flat space. The presence of gravity would reduce the global symmetry group of the fundamental theory to the scale invariance only. We discuss how the effective Lagrangian respecting …
Chromosome Painting in Cercopithecus petaurista (Schreber, 1774) Compared to Other Monkeys of the Cercopithecini Tribe (Catarrhini, Primates)
2023
The Cercopithecini tribe includes terrestrial and arboreal clades whose relationships are controversial, with a high level of chromosome rearrangements. In order to provide new insights on the tribe’s phylogeny, chromosome painting, using the complete set of human syntenic probes, was performed in Cercopithecus petaurista, a representative species of the Cercopithecini tribe. The results show C. petaurista with a highly rearranged karyotype characterized by the fission of human chromosomes 1, 2, 3, 5, 6, 8, 11, and 12. These results compared with the literature data permit us to confirm the monophyly of the Cercopithecini tribe (fissions of chromosomes 5 and 6), as previously proposed by ch…
Crowdsourcing as a mode of open innovation: Exploring drivers of success of a multisided platform through system dynamics modelling
2020
This article aims to explore drivers of success of a crowdsourcing platform. The study conceptualizes crowdsourcing as a mode of open innovation and places such a concept within the context of the sharing economy. Upon this framework, the paper analyses the case of InnoCentive, a successful crowdsourcing platform where innovation-driven organizations search for solutions to their R&D tasks. The system dynamics model frames main InnoCentive business processes and offers a causal perspective on the relationships between platform performance—in terms of users base—and resources structure. The discussion on simulation outputs is carried out through a dynamic performance management view of p…
Business model scaling and growth hacking in digital entrepreneurship
2023
Creating an innovative product and validating an innovative business model may not be enough for digital startups to be competitive. To grow fast and expand globally, digital startups need to innovate their business model during the scaling phase. A pragmatic approach has recently been proposed to support digital entrepreneurs engaging in business-model innovation during the scaling phase (i.e., business-model scaling), a strategy known as growth hacking. However, we know little about its theoretical grounding and how effective growth hacking is, as businesses lack methodologies to assess its effectiveness before committing resources and investments. To fill this gap, we developed a method …
The Quest for Underpinning Theory of Enterprise Architecture - General Systems Theory
2017
Enterprise architecture originates from the 1980’s. It emerged among ICT practitioners to solve complex problems related to information systems. Currently EA is also utilised to solve business problems, although the focus is still in ICT and its alignment with business. EA can be defined as a description of the current and future states of the enterprise, and as a change between these states to meet stakeholder’s goals. Despite its popularity and 30 years of age, the literature review conducted on top information and management science journals revealed that EA is still lacking the sound theoretical foundation. In this conceptual paper, we propose General Systems Theory (GST) for underpinni…
A posteriori error estimates for time-dependent reaction-diffusion problems based on the Payne-Weinberger inequality
2015
We consider evolutionary reaction-diffusion problem with mixed Dirichlet--Robin boundary conditions. For this class of problems, we derive two-sided estimates of the distance between any function in the admissible energy space and exact solution of the problem. The estimates (majorants and minorants) are explicitly computable and do not contain unknown functions or constants. Moreover, it is proved that the estimates are equivalent to the energy norm of the deviation from the exact solution.
Estimating Regional Input Coefficients and Multipliers: The Use of FLQ is Not a Gamble
2014
Flegg A. T. and Tohmo T. Estimating regional input coefficients and multipliers: the use of FLQ is not a gamble, Regional Studies. This paper re-examines the Finnish evidence presented by Lehtonen and Tykkylainen on the use of location quotients (LQs) in estimating regional input coefficients and multipliers. They argue that the choice of an LQ-based method is a gamble and that there is no single method that can be recommended for general use. It is contended here that this evidence is erroneous and that the FLQ (Flegg's location quotient) yields results far superior to those from competing formulae, so it should provide a satisfactory way of generating an initial set of input coefficients.…
Accelerating the Americanization of Management Education
2015
The Journal of Management Inquiry astutely predicted in 2004 that the Americanization of business education would not just continue but increase. Ten years later, it is arguable that the acceleration of the Americanization of management education has exceeded all expectations. To theoretically build toward understanding how and why the American business education model has been adopted to different extents, this comparative study builds on the institutional logics perspective, arguing that different institutional logics can potentially explain the various forms and patterns of Americanization and how they are manifested in the world’s business schools.