119 results found
Gheorghiade P, Vasiliauskaite V, Diachenko A, et al., 2023, Entropology: an Information-Theoretic Approach to Understanding Archaeological Data, Journal of Archaeological Method and Theory, Vol: 30, Pages: 1109-1141, ISSN: 1072-5369
The main objective of this paper is to develop quantitative measures for describing the diversity, homogeneity, and similarity of archaeological data. It presents new approaches to characterize the relationship between archaeological assemblages by utilizing entropy and its related attributes, primarily diversity, and by drawing inspiration from ecology. Our starting premise is that diachronic changes in our data provide a distorted reflection of social processes and that spatial differences in data indicate cultural distancing. To investigate this premise, we adopt a parsimonious approach for comparing assemblage profiles employing and comparing a range of (Hill) diversities, which enable us to exploit different aspects of the data. The modelling is tested on two seemingly large datasets: a Late Bronze Age Cretan dataset with circa 13,700 entries (compiled by PG); and a 4th millennium Western Tripolye dataset with circa 25,000 entries (compiled by AD). The contrast between the strongly geographically and culturally heterogeneous Bronze Age Crete and the strongly homogeneous Western Tripolye culture in the Southern Bug and Dnieper interfluve show the successes and limitations of our approach. Despite the seemingly large size of our datasets, these data highlight limitations that confine their utility to non-semantic analysis. This requires us to consider different ways of treating and aggregating assemblages, either as censuses or samples, contingent upon the degree of representativeness of the data. While our premise, that changes in data reflect societal changes, is supported, it is not definitively confirmed. Consequently, this paper also exemplifies the limitations of large archaeological datasets for such analyses.
Diachenko A, Rivers RJ, Sobkowiak-Tabaka I, 2023, Convergent Evolution of Prehistoric Technologies: the Entropy and Diversity of Limited Solutions, Journal of Archaeological Method and Theory, Vol: 30, Pages: 1168-1199, ISSN: 1072-5369
<jats:title>Abstract</jats:title><jats:p>Linking the likelihood of convergent evolution to the technologies’ complexity, this paper identifies the scales of technological diffusion and convergence, <jats:italic>i.e.</jats:italic>, the evolving of structures that are similar, but not related to a common “ancestor.” Our study provides quantitative measures for understanding complexity and connectivity in technologies. The utility of our approach is exemplified through the case study of Cucuteni-Tripolye pottery kilns in Chalcolithic Southeastern Europe. The analysis shows that technological evolution has to be scaled to the “technologically important” (in quantitative terms) component parts, whose introduction shapes a ground for extinction and self-evolvement caused by the cascade effects along technological design structure. Similar technological solutions to the technological design structure engender the spread of similar devices in various locations. Surprisingly, such a broad distribution may be the result of relatively low internal diversity, rather than arising from higher efficiency. This gives some reasons for the underestimation of convergence as a mechanism for evolution of technology in current prehistoric archaeology.</jats:p>
Rivers R, Paliou E, Evans T, 2023, Gravity and Maximum Entropy Models, The Oxford Handbook of Archaeological Network Research, Editors: Brughmans, Mills, Munson, Peeples, Publisher: Oxford University Press, Pages: 186-199, ISBN: 9780198854265
Gravity models are a class of quantitative models that can be used for describing the spatial characteristics of social interactions, providing a realization of Tobler’s “law” of geography that “near things are more related than distant things.” In archaeology, they are particularly suited for describing historic and prehistoric “exchange” and “settlement formation.” Although, quantitatively, they were originally little more than mimicry of Newtonian gravitation, they arise naturally in some forms of economic modeling and as the “most likely” outcomes (MaxEnt) from limited knowledge. We discuss several of their key applications to archaeological data.
Rivers R, Evans T, 2020, How do we avoid imposing the present on the past when modelling spatial interactions?, Documenta Praehistorica, Vol: 47, Pages: 462-475, ISSN: 1318-6701
Theoretical archaeological modelling for describing spatial interactions often adopts contemporary socioeconomic ideas whose C20th language gets translated into historical behaviour with the simplest of lexicons. This can lead to the impression that the past is like the present. Our intention in this paper is that, when this happens, to strip out as much of the contemporary context as we can, to bring modelling back to basic epistemic propositions. We suggest that although the underlying ontology may be specific to contemporary society the epistemology has much greater generality, leading to essentially the same conclusions without the carapace of intricate economics.
Lee D-S, Lin C-Y, Rivers RJ, 2020, Large phonon time-of-flight fluctuations in expanding flat condensates of cold Fermi gases, JOURNAL OF PHYSICS-CONDENSED MATTER, Vol: 32, ISSN: 0953-8984
Rivers R, Knitter D, Bilger M, et al., 2018, CRC1266-A2/moin: Release after Moin Summer School
This release contains all the code created during the moin Summer School, jointly organized by CRC1266 project A2 and ISAAKiel.It is a major refactoring of all previous code of moin. However, concept and general wording remains the same.Please note that the different new methods implemented needs proper testing! This release is intended to be the starting point of all these tests and corresponding code changes.
Rivers RJ, Steer DA, Lin C-Y, et al., 2018, When are two fermions a simple boson? New Gross-Pitaevskii actions for cold Fermi condensates, ANNALS OF PHYSICS, Vol: 396, Pages: 495-516, ISSN: 0003-4916
Evans TS, Rivers RJ, 2017, Was Thebes necessary? Contingency in spatial modeling, Frontiers in Digital Humanities, Vol: 4, ISSN: 2297-2668
When data are poor, we resort to theory modeling. This is a two-step process. We have first to identify the appropriate type of model for the system under consideration and then to tailor it to the specifics of the case. To understand settlement formation, which is the concern of this article, this involves choosing not only input parameter values such as site separations but also input functions that characterizes the ease of travel between sites. Although the generic behavior of the model is understood, the details are not. Different choices will necessarily lead to different outputs (for identical inputs). We can only proceed if choices that are “close” give outcomes that are similar. Where there are local differences, it suggests that there was no compelling reason for one outcome rather than the other. If these differences are important for the historic record, we may interpret this as sensitivity to contingency. We re-examine the rise of Greek city-states as first formulated by Rihll and Wilson in 1979, initially using the same “retail” gravity model. We suggest that, although cities like Athens owe their position to a combination of geography and proximity to other sites, the rise of Thebes is the most contingent, whose success reflects social forces outside the grasp of simple network modeling.
Hsiang J-T, Lee D-S, Lin C-Y, et al., 2015, Quantum sound-cone fluctuations in cold Fermi gases: Phonon propagation, PHYSICAL REVIEW A, Vol: 91, ISSN: 1050-2947
Rivers R, Evans T, Knappett C, 2015, From oar to sail: The role of technology and geography in the evolution of Bronze Age Mediterranean networks, Maritime Networks: Spatial structures and time dynamics, Pages: 63-76, ISBN: 9781138911253
Throughout port and maritime studies, the link between flows and the socio-economic characteristics of localities has been investigated mostly qualitatively. While systematic international quantitative investigations remain scarce and dispersed, their reliance upon port tonnage statistics tends to ignore maritime linkages. In the maritime network, the so-called industrial centres as well as the agri-bulk hubs are essential for feeding the more urbanized port regions concentrating populations and services along the main trunk line. This chapter provides an analysis of the Pacific Rim area based on the comparison of vessel movement data and regional socio-economic data collected at the level of subnational entities or port regions. The analysis of the socio-economic determinants of port and maritime traffic across the Pacific Rim region is fruitful in many ways. Even though the analysis only focuses on the Pacific Rim area, California stands out as the largest traffic region to which multiple commodity flows of various natures converge, mostly containers.
Evans TS, Rivers RJ, 2014, New approaches to Archaic Greek Settlement Structure, Les Nouvelles de l'archéologie, Vol: 135, Pages: 21-27, ISSN: 0242-7702
Recent developments in network theory have led to the creation of new Spatial Interaction Models (SIMs) and a reappraisal of existing models. Although not directed at the archaeology community, these models generalise the familiar gravitational models and Proximal Point Analysis (PPA) used by archaeologists for many years to help explain the archaeological record. However, a problem arises in archaeology that, with the increasing suite of plausible models that now exist, it is unclear how to choose one model over another. This can lead to the criticism that, if we hunt hard enough, we may be doing no more than finding a model which can be manipulated to conform to our preconceptions. In recent articles we have begun to address this criticism (Evans 2014, in press) with particular reference to the maritime networks of the MBA Aegean (Rivers 2014, in press). Different historical periods require different approaches and in this paper we continue this analysis by re-examining the onset of centralisation in mainland Greek city states of the 9th and 8th centuries BCE. Pioneering work on this archaic settlement structure was performed in 1987 by Rihll and Wilson (Rihll & Wilson 1987, 2: 5-32; 1991: 59-95), adapting a 'retail' model devised originally for urban planning. One alternative approach is given by a recent cost-benefit model termed ariadne, developed by ourselves (Evans, Knappett & Rivers 2009, 7: 451-79; Knappett, Evans & Rivers 2008, 82: 1009-84; 2011, 85: 1008-23), initially designed for Bronze Age maritime networks. A comparison of these models and other simpler SIMs for archaic settlements highlights the problems of modelling archaeological data. In particular we examine what constitutes model 'robustness' and the way in which different models handle 'contingency' when handling periods of rapid change.
Weir DJ, Monaco R, Koshelets VP, et al., 2013, Gaussianity revisited: exploring the Kibble-Zurek mechanism with superconducting rings, JOURNAL OF PHYSICS-CONDENSED MATTER, Vol: 25, ISSN: 0953-8984
Hsiang J-T, Lin C-Y, Lee D-S, et al., 2013, The role of causality in tunable Fermi gas condensates, JOURNAL OF PHYSICS-CONDENSED MATTER, Vol: 25, ISSN: 0953-8984
Weir DJ, Monaco R, Rivers RJ, 2013, Defect Formation in Superconducting Rings: External Fields and Finite-Size Effects, JOURNAL OF LOW TEMPERATURE PHYSICS, Vol: 171, Pages: 788-796, ISSN: 0022-2291
Rivers R, Knappett C, Evans T, 2013, Network Models and Archaeological Spaces, Computational Approaches to Archaeological Spaces, Editors: Bevan, Lake, Publisher: Left Coast Press, ISBN: 978-1-61132-346-7
Rivers R, Knappett C, Evans T, 2013, What makes a site important? Centrality, gateways and gravity, Network Analysis in Archaeology: New Approaches to Regional Interaction, Editors: Knappett, Publisher: OUP, Pages: 125-150
Lin C-Y, Lee D-S, Rivers RJ, 2012, Nonequilibrium damping of the collective motion of homogeneous cold Fermi condensates with Feshbach resonances, PHYSICAL REVIEW A, Vol: 85, ISSN: 1050-2947
Collisionless damping of a condensate of cold Fermi atoms, whose scattering is controlled by a Feshbach resonance, is explored throughout the BCS and Bose-Einstein condensate (BEC) regimes when small perturbations on its phase and amplitude modes are turned on to drive the system slightly out of equilibrium. Using a one-loop effective action, we first recreate the known result that for a broad resonance the amplitude of the condensate decays as t(-1/2) at late times in the BCS regime, whereas it decays as t(-3/2) in the BEC regime. We then examine the case of an idealized narrow resonance, and find that this collective mode decays as t(-3/2) throughout both the BCS and BEC regimes. Although this seems to contradict earlier results that damping is identical for both broad and narrow resonances, the breakdown of the narrow resonance limit restores this universal behavior. More measurably, the phase perturbation may give a shift on the saturated value to which the collective amplitude mode decays, which vanishes only in the deep BCS regime when the phase and amplitude modes are decoupled.
Evans TS, Rivers RJ, Knappett C, 2012, INTERACTIONS IN SPACE FOR ARCHAEOLOGICAL MODELS, ADVANCES IN COMPLEX SYSTEMS, Vol: 15, ISSN: 0219-5259
Evans TS, Rivers RJ, 2012, Interactions in Space for Archaeological Models, Advances in Complex Systems, Vol: 15
In this article we examine a variety of quantitative models for describingarchaeological networks, with particular emphasis on the maritime networksof the Aegean Middle Bronze Age. In particular, we discriminate betweenthose gravitational networks that are most likely (maximum entropy) andmost efficient (best cost/benefit outcomes).
Knappett C, Rivers R, Evans T, 2011, The Theran eruption and Minoan palatial collapse: new interpretations gained from modelling the maritime network, ANTIQUITY, Vol: 85, Pages: 1008-1023, ISSN: 0003-598X
Rivers RJ, Evans TS, Knappett C, 2011, Modelling maritime interaction in the Aegean Bronze Age, II. The Theran eruption and Minoan palatial collapse, Antiquity: a quarterly review of archaeology, Vol: 85, Pages: 1008-1023
What was the effect on Late Minoan civilisation of the catastrophic destruction of Akrotiri on Thera (Santorini) by volcanic eruption? Not much, according to the evidence for continuing prosperity on Crete. But the authors mobilise their ingenious mathematical model (published in Antiquity 82: 1009–1024), this time to show that the effects of removing a major port of call could have impacted after an interval, as increased costs of transport gradually led to ever fewer routes and eventual economic collapse.
Lin C-Y, Lee D-S, Rivers RJ, 2011, Spontaneous vortex production in driven condensates with narrow Feshbach resonances, PHYSICAL REVIEW A, Vol: 84, ISSN: 1050-2947
Rivers RJ, 2011, PATH INTEGRALS FOR QUASI-HERMITIAN HAMILTONIANS, INTERNATIONAL JOURNAL OF MODERN PHYSICS D, Vol: 20, Pages: 919-932, ISSN: 0218-2718
Rivers RJ, 2011, Path Integrals for Pseudo-Hermitian Hamiltonians, International Conference on Pseudo-Hermitian Hamiltonians in Quantum Physics, Publisher: SPRINGER/PLENUM PUBLISHERS, Pages: 1081-1096, ISSN: 0020-7748
Rivers RJ, 2011, Path Integrals for (Complex) Classical andQuantum Mechanics, AAMP7, Pages: 83-89
An analysis of classical mechanics in a complex extension of phase space shows thata particle in such a space can behave in a way redolant of quantum mechanics; addi-tional degrees of freedom permit 'tunnelling' without recourse to instantons and lead totime/energy uncertainty. In practice, 'classical' particle trajectories with additional de-grees of freedom have arisen in several di®erent formulations of quantum mechanics. Inthis talk we compare the extended phase space of the closed time-path formalism withthat of complex classical mechanics, to suggest that ~ has a role in our understanding ofthe latter. However, di®erences in the way that trajectories are used make a deeper com-parison problematical. We conclude with some thoughts on quantisation as dimensionalreduction.
Weir DJ, Rivers RJ, 2011, Fluxoid formation: size effects and non-equilibrium universality, Conference on Condensed Matter and Materials Physics (CMMP10), Publisher: IOP PUBLISHING LTD, ISSN: 1742-6588
Monaco R, Mygind J, Rivers RJ, et al., 2009, Spontaneous fluxoid formation in superconducting loops, PHYSICAL REVIEW B, Vol: 80, ISSN: 2469-9950
Lin C-Y, Lee D-S, Rivers RJ, 2009, Nonuniversal behavior of cold Fermi condensates with narrow Feshbach resonances, PHYSICAL REVIEW A, Vol: 80, ISSN: 1050-2947
Jones HF, Rivers RJ, 2009, Which Green functions does the path integral for quasi-Hermitian Hamiltonians represent?, PHYSICS LETTERS A, Vol: 373, Pages: 3304-3308, ISSN: 0375-9601
Evans TS, Knappett C, Rivers RJ, 2009, Using Statistical Physics To Understand Relational Space: A Case Study From Mediterranean Prehistory, Complexity Perspectives on Innovation and Social Change, Editors: Lane, Pumain, Leeuw, West, Lane, Pumain, Leeuw, West, Publisher: Springer Science + Business Media, Pages: 451-479, ISBN: 9781402096624
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