Exploratory Models in a time of Big Data

This paper aims to trigger discourse about the emergence of a new type of social scientific model — Exploratory Models — which draw on Big Data, computer modeling and interdisciplinary research to tackle complex social scientific processes. First, we define Exploratory Models referring to Batty and Morgan and Morrison. We then present changes to the traditional modeling paradigm. We show how Exploratory Models circumvent challenges related to the idiosyncracy, self-reflexivity and acceleration of social phenomena, which limit predictive effectiveness of traditional models. We show that Exploratory Models are better equipped to tackle complex problems due to their capacity to process heterogeneous datasets. Having established that Exploratory Models are predominantly problem- and data-driven, we emphasize that scientific theory is indispensable to their progress. Finally, the development of an integrative platform is suggested as a way of maximizing the benefits of this approach. Discussion concludes by flagging areas for further research.     

Urban size and KIBS vertical disintegration: the case of Milan

The literature shows that market size favours firms’ vertical disintegration because it reduces transaction and knowledge coordination costs. The existing evidence is based primarily on cross-sectional data and on the manufacturing sector, with little or no attention is given to longitudinal data and services. This paper estimates the effect of urban size on the purchase of service inputs by knowledge-intensive business service firms located in the metropolitan region of Milan. Relying on a rich panel dataset, and adopting different econometric techniques to overcome endogeneity, we find a positive and statistically significant effect of increased urban population on the degree of KIBS vertical disintegration only when urban size is measured at the province level. We also find that this effect holds particularly in the case of traditional professional- rather than technology-related activities.     

3D Digital Survey of Iron Tie-Rods in Masonry Buildings: Cross-Sections Analysis and Error Estimation

Ancient iron tie-rods are handcrafted elements with large geometric irregularities, due to production techniques (they are shaped by hammering and linked by hot-forging) and corrosion processes. In common practice, their cross section (that is one of the main parameter to assess their strength) is manually measured on site with a manual caliber. By analyzing a set of detailed three-dimensional (3D) digital surveys of real ancient tie-rods, this study provide an evaluation of the errors made by in-situ manual geometric measurements. In particular, it shows that, in some cases, manual on-site survey is sufficiently reliable and has errors that fall below 10%. Moreover, it shows that when tie-rods have high corrosion levels in hidden zones (typically those close or within the retaining walls) the on-site survey of visible parts only may produce far greater errors that exceed 100%, leading to a strong overestimation of the cross-section of the tie. The ongoing study is a first step toward the definition of correction coefficients to be applied to the on-site manual measurements of ancient tie-rods, with the final aim to improve the reliability of structural analyses.     

Justification for reassessing elemental analysis data of ceramics,sediments and lithics using rare earth element concentrations and ratios

The mensuration of multi‐elemental concentrations from assorted archaeological materials has always required great care and attention to detail to ensure good‐quality data and their ensuing interpretations. Although most suspect data were generated before the wide use of computers, error‐free data are not still a certainty. This paper presents the geochemical rationale for a proposed chemical data‐assessment process, using a globally dispersed collection of ceramic, sediment and lithic data. It is argued that this process can allow archaeologists and archaeometrists to investigate systematically older and current data sets and, if need be, alter them to the reliable values they were originally intended to include.     

Lichenometric constraints on the age of the Huashan Grottoes, East China

Lichenometry is a method of dating that has been widely used in glaciated areas for determining the minimum age of exposure of a geomorphic landform during the late Holocene. This paper presents a regional calibration data set of lichen thallus sizes versus rock surface ages for the Huashan area, East China, based on measurements of yellow-green Rhizocarpon lichens on the known-age substrates at eight sites. An empirical relationship between thallus sizes and rock surface ages was established using both the traditional regression and the Bayesian approaches. Using the Bayesian calibration, the minimum age of the Huashan Grottoes was dated from 450 ± 60 to 330 ± 60 years ago, corresponding to the late Ming Dynasty (AD 1477–1632). These dates are generally consistent with those predicted from the regression-based linear growth curve. Our results suggest that applications of this technique can be safely extended to the non-glaciated areas.     

The canopic jars of Rameses II: real use revealed by molecular study of organic residues

Four blue-glazed faience jars, on exhibition in the Louvre Museum, are referred to as the canopic jars of Rameses II. Their recent typological re-examination rendered this original assignment questionable. In order to clearly determine their use, a study of two successive organic residues from the canopic jars, using molecular biomarkers analysed by GC-MS and LC-MS and absolute dating by ¹⁴C, was initiated. The results revealed that these two materials were not contemporary to the reign of Rameses II. The first one, scraped from the interior face of one jar, was identified as an unguent made of coniferous oil and animal fat and dated from the Third Intermediate Period. The second one, originally stored with glued linen inside one jar, is likely an embalming substance, made of pure vegetable resin (Pistacia) and dated from the Ptolemaic Period. These results clarify a controversy which has been lasting over a century. The famous blue-glazed faience jars are not the canopic jars of Rameses II but are confirmed as situlae which were reused at least two times: first to store unguents during the Intermediate Period and later to store embalming packages of an unknown person during the Ptolemaic period.     

大数据背景下国内人文地理研究进展与方法审视

通过梳理人文地理领域杂志近年大数据文章解释其与大数据应用的关系，强调其应用给人文地理学研究带来机遇和挑战：①大数据作为研究方法，不能代替传统人文地理研究范式，而是对现研究方法的补充。大数据和小数据需对话交流；②大数据本身是一种话语权，嵌入人文地理研究系统。保证人文地理学多样性，避免过度依赖大数据，需在批判角度审视和运用；③需关注大数据对于人文地理学研究方法和思想的影响；④运用大数据解读地理和空间过程复杂性的同时，应看到大数据应用对公共服务的潜力，思考其结果如何更好的服务社会。     

Platform Capitalism’s Hidden Abode: Producing Data Assets in the Gig Economy

In this article, we argue that the governance of gig work under conditions of financialised platform capitalism is characterised by a process that we call “dual value production”: the monetary value produced by the service provided is augmented by the use and speculative value of the data produced before, during, and after service provision. App-governed gig workers hence function as pivotal conduits in software systems that produce digital data as a particular asset class. We reflect on the production of data assets and the unequal distribution of opportunities for their valorisation, after which we survey a number of strategies seeking data-centric worker empowerment. These strategies, we argue, are crucial attempts to push back against platform capitalism’s domination, bankrolled by what we term “meta-platforms”. Ultimately, it is the massive wealth and synergetic capacities of meta-platforms that constitute the most formidable obstacle to worker power and social justice in increasingly data-driven societies.     

考古地层的三维建模方法在秦始皇帝陵考古勘探中应用尝试

为了更清楚地展示秦始皇帝陵地区考古地层的三维空间关系,并为后期考古工作中空间数据挖掘做准备,借鉴三维地质建模技术,提出了考古地层三维建模方法。基于探孔数据构建了考古地层三维模型。该模型清楚地展示了秦始皇帝陵地区考古地层的三维空间关系,为田野考古数字化工作提供一种新思路、新方法。     

基于海量点云数据的大雁塔三维重建

古建筑三维重建已成为历史遗迹保护与修复的重要内容。为了探讨三维激光扫描数据的获取流程、数据处理方法,以三维激光扫描获取的大雁塔海量点云数据为例,研究了古建筑三维重建中点云数据获取与处理的详细过程。联合Cyclone、AutoCAD和3D-Max软件的优点构建了大雁塔真实的横面、剖面、立面模型,其中重点研究了海量点云数据在Cyclone软件中分块建模的方法。结果表明:将拼接好的大雁塔海量点云数据分块建模,不仅加快了数据处理的速度,而且符合精度要求。在点云数据拼接时采用标靶拼接和同名点拼接相结合及测站间两两拼接之后再整体拟合平差的方法,减少了拼接中的误差,使每站拼接误差都不超过3cm。在建模过程中的墙体拟合是上万个点云经过平差计算得到,精度高达2mm。最后在3D-Max软件中组合、渲染和贴图,真实地构建了大雁塔三维立体模型。为古建筑数字化存档和后期的修缮工作提供了重要的依据。