Continuous‐Time Modeling with Spatial Dependence

(Spatial) panel data are routinely modeled in discrete time (DT). However, compelling arguments exist for continuous‐time (CT) modeling of (spatial) panel data. Particularly, most social processes evolve in CT, so that statistical analysis in DT is an oversimplification, gives an incomplete representation of reality, and may lead to misinterpretation of estimation results. The most compelling reason for a CT approach is that, in contrast to DT modeling, it allows adequate modeling of dynamic adjustment processes. This article introduces spatial dependence in a CT modeling framework. We propose a nonlinear structural equation model (SEM) with latent variables for estimation of the exact discrete model (EDM), which links CT model parameters to DT observations. The use of a SEM with latent variables enables a specification that accounts for measurement errors in the variables, leading to a reduction of attenuation bias (i.e., disattenuation). The SEM‐CT model with spatial dependence developed here is the first dynamic SEM with spatial dependence. A simple regional labor market model for Germany, comprising changes in unemployment and population as endogenous state variables, and changes in regional average wages and in the structure of the manufacturing sector as exogenous input variables, illustrates this spatial econometric SEM‐CT framework. El modelamiento de datos panel espaciales se realiza habitualmente utilizando una conceptualización del tiempo discreto (TD). Sin embargo, existen argumentos de peso para conceptualizar el tiempo de manera continua (TC). En concreto, la mayoría de procesos sociales se desarrolla en TC, por lo que el análisis estadístico en DT trae como consecuencia una simplificación excesiva de los procesos, da una representación incompleta de la realidad, y puede conducir a una interpretación errónea de los resultados de la estimación. La razón más convincente para el uso de un enfoque CT es que a diferencia de modelos DT, una conceptualización CT permite el modelado adecuado de los procesos de ajuste dinámico (dynamic adjustment). Este artículo incorpora la dependencia espacial en un marco de modelamiento con CT. Los autores proponen un modelo de ecuaciones estructurales no lineal (nonlinear structural equation model ‐SEM) con variables latentes para la estimación del modelo discreto exacto (exact discrete model‐EDM), que vincula los parámetros del modelo CT a las observaciones de DT. El uso de un SEM con variables latentes permite una especificación que da cuenta de los errores de medición en las variables, dando lugar a una reducción del sesgo de atenuación (es decir, “desatenuacion”). El modelo SEM‐CT con dependencia espacial desarrollado en el presente estudio es el primer SEM dinámico con dependencia espacial. Para ilustrar el marco conceptual SEM‐CT los autores presentan un modelo simple del mercado laboral regional de Alemania. El modelo está compuesto por los cambios en el desempleo y la población como variables endógenas de estado, y los cambios en los salarios regionales promedio y en la estructura del sector manufacturero como variables de entrada exógenas. （空间）面板数据通常基于离散时间（DT）进行建模。然而更令人信服的观点是基于连续时间（CT）进行（空间）面板数据建模。特别是多数社会过程均在连续时间中演化,基于离散时间的统计分析可能过度简化,使得对现实状况的表达不完备,并可能导致对估计结果的错误解释。相比于离散时间（DT）建模,连续时间（CT）建模最具说服力的原因在于在建模过程中允许足够多的动态调整。本文介绍了CT模型框架中的空间依赖性。把CT模型参数链接到DT观察值中,我们提出了用于估计精确离散模型（EDM）的包含潜变量的非线性结构方程模型（SEM）。包含潜在变量的SEM提供了变量测量误差的计算方案,使得衰减偏差（如反衰减性）减小。本文了提出的空间相关SEM‐CT模型是第一个动态空间相关的SEM模型,并以德国一个简单的区域劳动力市场模型为例,以失业和人口构成变化为内生状态变量,以区域平均工资和制造业结构部门变化为外生输入变量,阐述了该空间计量SEM‐ CT模型的框架。     

Explorers’ Bodies in Arctic Mediascapes: Celebrating the Return of the Austro-Hungarian Polar Expedition in 1874

Abstract

This article investigates the welcoming receptions held on the return of the Austro-Hungarian Polar Expedition (1872–1874) as part of a Scandinavian and Central European discourse of the Arctic and of Arctic exploration. Also called the Payer–Weyprecht or Tegetthoff Expedition, it was subjected to a long series of such public celebrations on its way home to Austria–Hungary via Norway, Sweden and Germany. While our access to these celebrations is through written sources such as newspaper reports, the celebrations themselves are here seen as constituting a discourse primarily made up of performative and material elements. This discourse is formed by values such as heroism, national identities, local identities, class and gender, and is regulated by the mediascape of the time, which gives a central role to the explorers’ bodies. The article focuses on welcoming receptions in Bergen and in Vienna. Differences between dominant topoi such as those of science and gendered attraction in Bergen and those of spectacular simulacra and exhaustion in Vienna can be ascribed to a combination of factors, but especially to the differences in the development of mass culture in the two contexts.     

Consuming campus: geographies of encounter at a British university

In this paper, we extend recent discussions on the geographies of encounter to examine how students and staff narrate their experiences of cross-cultural contact on a British university campus. In theory, the campus environment offers opportunities for more intense and prolonged forms of contact than the ephemeral micro-scale forms of interaction that have dominated much of the literature on encounters. In practice, however, our interviews suggest that many respondents tend to self-segregate, or in some instances are prevented from mixing with ‘others’ through institutional arrangements. As we also illustrate, the pressures posed by commercial forces on campus orientate certain students towards lifestyle choices and expectations which exclude others.     

Radiocarbon dating of the bronze age bone pins from Eurasian steppe

Bone catapult and hammer-headed pins played one of very specific roles in funerary offerings in the Bronze Age graves uncovered in the Eurasian Steppes and the North Caucasus. Scholars used different types of pins as key grave offerings for numerous chronological models. For the first time eight pins have been radiocarbon dated. ¹⁴C dating of bone pins identified the catapult type pin as the earliest one. They marked the period of the Yamnaya culture formation. Then Yamnaya population produced hammer-headed pins which became very popular in other cultural environments and spread very quickly across the Steppe and the Caucasus during 2900–2650 cal BC. But according to radiocarbon dating bone pins almost disappeared after 2600 cal BC.     

The use of stereoscopic images taken from a microdrone for the documentation of heritage – An example from the Tuekta burial mounds in the Russian Altay

To analyse, interpret and manage our cultural heritage it is important to have an accurate and realistic representation of it. Documenting this heritage involves geographic techniques such as photogrammetry, for which a lot of rather expensive and extensive platforms are already in use. However, a microdrone, a recently developed unmanned aerial vehicle platform is a cheaper and easy to handle tool. To test the very limits of the microdrone and its accompanying data-acquisition and data-processing software, we collected data from a remote area in Tuekta, in the Russian Altay Mountains. This paper presents the challenges faced during the whole photogrammetric procedure from planning the flights to producing the final deliverables.     

Artificial Intelligence, 3D Documentation,and Rock Art—Approaching and Reflecting on the Automation of Identification and Classification of Rock Art Images

Journal of Archaeological Method and Theory - Rock art carvings, which are best described as petroglyphs, were produced by removing parts of the rock surface to create a negative relief. This...     

Ammonite dating of latest Cretaceous mosasaurid reptiles (Squamata,Mosasauroidea) from Jordan—preliminary observations

Jagt, J.W.M., Jagt-Yazykova, E.A., Kaddumi, H.F. & Lindgren, J., April 2017. Ammonite dating of latest Cretaceous mosasaurid reptiles (Squamata, Mosasauroidea) from Jordan—preliminary observations. Alcheringa 42, 587-596. ISSN 0311-5518

Newly collected ammonoid material from the uppermost Cretaceous portion of the Muwaqqar Chalk Marl Formation exposed some 30 km southeast of the Qasr Al’Harrana area (east-central Jordan) includes medium-sized baculitids (Baculites ovatus auctorum, non Say), the sphenodiscid Libycoceras acutodorsatus (Noetling) and the pachydiscids Menuites fresvillensis (Seunes) and Pachydiscus (Pachydiscus) dossantosi (Maury). Of the two last named taxa, the former is a good marker species for the upper Maastrichtian, with records from Europe, central Chile, South India, Baluchistan (Pakistan), Australia, Madagascar and South Africa. The latter is known from the United Arab Emirates/Oman border area, from strata of (late) early to early late Maastrichtian age, as well as from more poorly constrained Maastrichtian levels in Brazil and Nigeria. A comparison with ammonoid assemblages from the Maastrichtian type area (southeast Netherlands/northeast Belgium) suggests correlation of the Muwaqqar Chalk Marl Formation with the middle/upper Maastricht Formation (Emael and Nekum members, ca 66.5–66.1 Ma) and the upper part of the coeval Kunrade Formation. However, associated ‘tegulated’ inoceramids of the Tenuipteria argentea group from the Muwaqqar Chalk Marl Formation favour equivalence with a higher level of the Maastrichtian type area, i.e., the Meerssen Member. From the upper Maastricht Formation and the equivalent upper part of the Kunrade Formation, the following mosasaur genera are currently known: Mosasaurus, Prognathodon, Plioplatecarpus and Carinodens. Interestingly, coeval strata of the Muwaqqar Chalk Marl Formation in east-central Jordan have yielded remains of a largely comparable suite comprising Prognathodon, Mosasaurus, Carinodens and an unnamed, highly derived plioplatecarpine.

John W.M. Jagt* [john.jagt@maastricht.nl], Natuurhistorisch Museum Maastricht, de Bosquetplein 6–7, 6211 kJ Maastricht, the Netherlands; Elena A. Jagt-Yazykova [eyazykova@uni.opole.pl], Opole University, Department of Biosystematics, Oleska 22, 45-052 Opole, Poland; Hani F. Kaddumi [blossom_trail@yahoo.com], Eternal River Museum of Natural History, Maroof Al’Rusafi Street, PO Box 11395, Amman 11123, Jordan; Johan Lindgren [johan.lindgren@geol.lu.se], Lund University, Department of Geology, Sölvegatan 12, 223 62 Lund, Sweden.