Cardiff University

About: Cardiff University is a education organization based out in Cardiff, United Kingdom. It is known for research contribution in the topics: Population & Context (language use). The organization has 34188 authors who have published 82643 publications receiving 3046531 citations. The organization is also known as: University of Cardiff & University College of South Wales and Monmouthshire.

Simulation of Land Development through the Integration of Cellular Automata and Multicriteria Evaluation

Abstract: Cellular automata (CA) simulation has become a popular method of exploring the behaviour of all kinds of self-organising systems. The city may clearly be viewed as such a system but one with a particularly complex set of transition rules. Many natural processes such as the spread of fire or vegetation can be modelled by a simple set of local rules. Insofar as the development of a piece of land depends on the neighbourhood situation as well as on the characteristics of a site, urban evolution can be treated in much the same way, with transition rules translating the evaluation of the location into a land conversion outcome. If this modelling paradigm is to be used to gain insight into real-world urban development processes, there is a need to discover ways of capturing the richness of land conversion behaviour in the simplifying mechanisms of CA. Our paper contributes to this research agenda by integrating multicriteria evaluation (MCE) into a CA simulation in order to define nondeterministic, multidimensional, and multilevel transition rules. An analytical hierarchy process is used to implement MCE-derived transition rules. The integrated MCE - CA model may be used in a gaming mode to explore how urban form evolves under different development regimes caricatured by the set of multicriteria weights. We use it to test loosely hypotheses about the nature of the regimes that have governed the expansion of a fast-growing southern Chinese city.

Planck 2013 results. XXIV. Constraints on primordial non-Gaussianity

Abstract: The Planck nominal mission cosmic microwave background (CMB) maps yield unprecedented constraints on primordial non-Gaussianity (NG). Using three optimal bispectrum estimators, separable template-fitting (KSW), binned, and modal, we obtain consistent values for the primordial local, equilateral, and orthogonal bispectrum amplitudes, quoting as our final result fNLlocal = 2.7 ± 5.8, fNLequil = -42 ± 75, and fNLorth = -25 ± 39 (68% CL statistical). Non-Gaussianity is detected in the data; using skew-Cl statistics we find a nonzero bispectrum from residual point sources, and the integrated-Sachs-Wolfe-lensing bispectrum at a level expected in the ΛCDM scenario. The results are based on comprehensive cross-validation of these estimators on Gaussian and non-Gaussian simulations, are stable across component separation techniques, pass an extensive suite of tests, and are confirmed by skew-Cl, wavelet bispectrum and Minkowski functional estimators. Beyond estimates of individual shape amplitudes, we present model-independent, three-dimensional reconstructions of the Planck CMB bispectrum and thus derive constraints on early-Universe scenarios that generate primordial NG, including general single-field models of inflation, excited initial states (non-Bunch-Davies vacua), and directionally-dependent vector models. We provide an initial survey of scale-dependent feature and resonance models. These results bound both general single-field and multi-field model parameter ranges, such as the speed of sound, cs ≥ 0.02 (95% CL), in an effective field theory parametrization, and the curvaton decay fraction rD ≥ 0.15 (95% CL). The Planck data significantly limit the viable parameter space of the ekpyrotic/cyclic scenarios. The amplitude of the four-point function in the local model τNL< 2800 (95% CL). Taken together, these constraints represent the highest precision tests to date of physical mechanisms for the origin of cosmic structure.

Theories in sustainable supply chain management: a structured literature review

Abstract: Purpose – The purpose of this paper is to investigate theoretical perspectives in sustainable supply chain management (SSCM) and contributes to understanding the current state of research in the field and its future development. Design/methodology/approach – This paper conducts a structured literature review and aims at mapping the use of theories in the field. The authors assess the current state of research, looking in more details at popular theories, and propose possible future avenues for the field to develop. Findings – Theory-building efforts in SSCM remain scarce, with the predominance of a few popular imported macro theories (resource-based view (RBV), stakeholder theory and institutional theory) having implications on the conceptualisation of SSCM and the topics researched to date. More theoretical contributions can potentially emerge from the adoption of original methodologies, the investigation of under-explored aspects of SSCM and the testing of recently developed frameworks. Research limitations/implications – Drawing on the analysis the authors propose an overarching map of popular theories in SSCM and define potential avenues towards the maturation of the discipline. A number of propositions are offered to guide future research. This study constitutes a first step towards understanding how theories in SSCM are developing and how SSCM has been conceptualised. Originality/value – The originality of this paper lies in its analytical focus on theories in SSCM, which have not been mapped to date.

Regional Development in the Knowledge-Based Economy: The Construction of Advantage

Abstract: In this introduction the editors showcase the papers by way of a structured project and seek to clarify the two key concepts cited in the title. We consider the history of the idea that knowledge is an economic factor, and discuss the question of whether regions provide the relevant system of reference for knowledge-based economic development. Current transformations in university-industry-government relations at various levels can be considered as a metamorphosis in industry organization. The concept of constructed advantage will be elaborated. The various papers arising from a conference on this subject hosted by Memorial University, Newfoundland, Canada are approached from this perspective.