Estimating original flake mass from 3D scans of platform area

This study confirms the increased capacity to predict flake mass that arises from more accurately measuring surface area in three dimensions using a digital scanner. We also reveal the existence of significantly different relationships between platform area and flake mass for flakes with different platform types and ventral and dorsal morphologies. These different relationships between platform surface area and mass have not been previously identified, and reveal the complexity of platform/mass relationships. Using multivariate regression of 3D platform surface area and external platform angle we improve the accuracy of predictions of original flake mass. We propose a method for studying reduction intensity on retouched flakes, based on comparing predictions of the initial mass of the flake with measurements of the mass following retouching to estimate the amount of mass removed through retouching. We name this approach the Initial-/Terminal-Mass Comparison, or ITMC. Our experiments demonstrate that the capacity of the 3D platform scans to predict flake mass, and by implication the capacity of the ITMC to estimate mass loss, rivals or exceeds the capacity demonstrated for existing reduction measures.     

The Oxus Temple: Localization of the Avestan Vahvi Dāityā

The article describes an attempt to determine the localization of the Avestan river Vahvi Dāityā using archaeological materials from the Oxus Temple (southern Tajikistan). A comparative analysis of archaeological materials and written sources makes it possible to identify the Amu Darya River with the Avestan Vahvi Dāityā.     

Numerical Evaluation of Topographic Effects at the Nicastro Ridge in Southern Italy

Numerical site response analyses were carried out on the Nicastro ridge in Southern Italy in order to investigate topographic effects. First, the analyses were carried out on a simplified model by employing simple artificial signals, in order to get preliminary physical insights into the two-dimensional phenomena involved. Then, numerical analyses were carried out on a more realistic heterogeneous subsoil model developed on the basis of geotechnical and geophysical investigations. Real accelerograms were selected for these analyses. Particular attention was devoted to separating topographic from stratigraphic amplification. Finally, the topographic amplification factors were compared with literature data and Eurocode 8 recommendations.     

基于视觉的明清古家具数字文化档案高精度三维重建

文物是人类在社会活动中遗留的具有历史、艺术、科学价值的遗物和遗迹。优秀物质文化遗产的体系庞大、内容繁杂,数字化三维重建是保存、管理文物的一种切实可行的方案,对文化传承意义深远。相比于三维激光扫描、结构光技术等在成本和效率方面都有待改进的现有方法,数字近景摄影测量在确保低成本、高效率的同时,还能够满足数据的精度要求和详细程度。如何应用摄影测量技术对文物进行高效三维重建,实现纹理、部件、结构的精细化描述,并综合管理文物以便线上欣赏、未来修复与辅助断代,对优秀物质文化遗产的保护与传承至关重要。 本研究提出了基于视觉的三维建模方案,分为明清家具分层管理体系构建、高效率数据采集与精细化三维重建、高精度三维数字文化档案建设三步。首先针对明清家具的文化特点,从类别、纹饰、部件出发进行分层分类管理,构建独特编码体系;其次基于数字近景摄影测量技术,提出了对明清家具进行非接触数据采集的低成本高效率方法,进行高精度三维重建;再次从三维信息中提取家具纹饰、部件、结构特征,以编码为依据建立索引,为三维数字文化档案的建设提供信息基础;最后设计分层索引结构,建设高精度数字文化档案,搭建互联网共享平台进行展示。 以100套明清古家具袖珍模型为实例进行精细化数字建模,基于数字近景摄影测量技术,将模型精度控制在毫米级别,完成了文物要素提取、分类体系搭建、属性信息管理与索引结构设计,构建了历史文化和三维模型融合的数字文化档案。研究结果表明,基于视觉的非接触视觉处理算法能够实现高精度三维重建,提出的技术方案能够保留模型的细节程度,并且降低了成本、提升了效率,对文物类别、部件、纹饰的属性管理与索引架构能有效管理文化信息,数字文化档案兼具科技、人文与传统美学,满足文物保护需求。明清家具三维数字文化档案可用于古家具的研究,有利于中国古代家具工艺的传承,而其中对于家具的历史年代的介绍鉴别能够辅助断代。下一步将考虑运用人工智能对家具纹饰和部件进行元素组合,生成个性化定制家具。同时将完善技术方案,应用范围拓展至小型文物,支撑数字博物馆建设。     

The 4th-century B.C. shipwreck at Mazotos,Cyprus: New techniques and methodologies in the 3D mapping of shipwreck excavations

Abstract

Well preserved ancient shipwrecks are rare in the archaeological record, but when discovered, they can provide valuable information on a wide range of research issues if analyzed and documented properly. In this paper we discuss the significance, potential, and constraints of mapping methods applied during the underwater excavation of shipwreck sites with special emphasis on stratigraphy, documentation of finds, and reconstruction of site formation processes. As a case study, we present the digital photogrammetry and computer vision software programs used in the excavation of the 4th-century b.c. shipwreck at Mazotos, Cyprus. Our goal is to develop a targeted documentation and mapping method of ongoing shipwreck excavations so that others can address complex research questions concerning this unique discipline of archaeology.     

The Tel Akko Total Archaeology Project (Akko,Israel): Assessing the suitability of multi-scale 3D field recording in archaeology

Abstract

Archaeology is a destructive discipline, and, unfortunately, the majority of methods employed by archaeologists to record and preserve the archaeological record consist of two-dimensional representations of three-dimensional (3D) subjects. Recent breakthroughs in 3D technology, however, have the potential to revolutionize the discipline. In recent years, multiple software suites capable of generating spatially accurate, photorealistic 3D models with a series of digital photographs have become available. Following a successful season of field testing in 2011, the Tel Akko Total Archaeology Project (Akko, Israel) expanded the use of Agisoft’s PhotoScan Pro—one of the commercially available software suites—to test the accuracy and suitability of the program for archaeological applications at multiple scales. After two years of field testing, it is clear that the implementation of PhotoScan Pro in archaeology facilitates unprecedented accuracy in field recording and digital heritage management, and provides a new outlet for the dissemination of archaeological data.     

Measuring core reduction using 3D flake scar density: a test case of changing core reduction at Klasies River Mouth,South Africa

A new core reduction index is presented, calculated as the ratio of flake scar number to 3D surface area (SDI). The index is tested experimentally on five types of core (blade, discoid, Levallois, biface and multiplatform cores) and then applied to the core assemblages from five sub-stages of the Middle Stone Age at Klasies River Mouth, South Africa. Preliminary results indicate that the SDI possesses the desirable attributes of a successful reduction index and is a significant improvement on traditional proxy measures of core reduction. The results of the archaeological case study confirm previous untested observations that cores from the Howiesons Poort and MSAIII sub-stages are more heavily reduced than preceding and following stages, and that local and exotic raw materials as well as different types of cores are all more heavily reduced during these periods. The SDI fills a significant lacuna in available core reduction measures.     

On Theme and Variation

Abstract

The ways in which the author, the sculptor Peter Randall-Page, has made use of the ideas of D’Arcy Thompson are described. How Thompson showed that commonalities of form and pattern exist across the biological and abiotic realms is described, and the implications that physical constraints limit and sometimes dominate the capabilities of evolutionary natural selection are explored. Since we evolved in a world shaped in this manner, the likelihood that this palette of forms is one that carries strong psychological meanings and associations is examined, and the ways in which these forms are a rich source of inspiration and allusion for visual artists are discussed, hinting at the play of opposing tendencies, the dance between order and randomness, and the ways in which nature can derive variations on a theme.     

Identifying of buried archaeological remains with ground penetrating radar,polarized microscope and confocal Raman spectroscopy methods in ancient city of Nysa,Aydin – Turkey

The aim of this study was to image buried remains and appoint buried Hellenistic street system, and identify minerals and rock types of the ancient city of Nysa, one of the most important historical sites of Turkey. This study used polarized microscope and confocal Raman spectroscopy (CRS) ground penetrating radar (GPR) method, to identify the buried remains, rock types and minerals.     

3D Digital Documentation,Assessment, and Damage Quantifi cation of the Al-Deir Monument in the Ancient City of Petra,Jordan

Abstract

The rock-cut monuments in the ancient city of Petra in Jordan form an outstanding tangible heritage site. Unfortunately, this important part of the world's cultural heritage is gradually being diminished due to weathering and erosion problems. In this research, an approach combining in situ surveying and laboratory analysis is applied in order to provide sufficient and comprehensive data regarding the documentation and evaluation of the status of the Al-Deir monument in Petra. The purpose was not only to quantify the damage, but also to make a first step towards creating a 3D monitoring programme of the deterioration rate. The approach presents a correlation study between the environmental condition and the surface weathering damage, using 2D mapping of the weathering form and accurate 3D realistic modelling from laser scanning and digital photogrammetry. The 2D mapping provides detailed weathering damage information for the entire stone surface of the monument, whereas the 3D modelling provides information on the spatial distribution and texture of the damage. Additionally, the 3D digital model can provide reference data as an exact guide to the restoration needed. In order to support the visual presentation of 3D surface details, a hybrid approach combining data from laser scanning and digital imagery was developed.

Studies of stone texture and spatial distribution of soluble salts were carried out at the monument in order to explain the mechanism of the weathering problem. Relative humidity, temperature, and wind are the main factors in the salt damage process. In order to study the effect of these conditions in the salt crystallization process a series of fieldwork investigations and laboratory work were undertaken. The results show that visible zoning of weathering damage is correlated to different salt concentrations.