Cultural heritage interactive 3D models on the web: An approach using open source and free software

Cultural heritage sites and artefacts get a significant added value from high-resolution 3D models. These models are increasingly available due to improvements in technology and to higher integration of survey techniques such as laser scanning and photogrammetry. In this paper we present a case study on the development of a web-based application for user access and interactive exploration of three-dimensional models by providing integrated geometrical and non-geometrical information into an intuitive interface. The main feature of this interactive system is to provide the user with a completely new visit experience based on a free interactive exploration interface of the object (i.e., not constrained by any predefined pathway) and on the opportunity to get more detailed information on specific parts of interest. A parallel aim achieved was to use, in data processing and in the architecture, open source tools and free software, thus providing full transparency on adopted methodology and data processing methods, and a cost effective solution both for server and client. Furthermore, the aspect of data size has been considered using a segmentation and simplification scheme and server-side data management to keep transmission size to a minimum, thus improving access speed.     

公元439年:河陇地域学术发展的转捩点

永嘉之乱中原流民迁入河陇及北魏太延五年河西士族东迁平城,这两次移民事件,对河陇学术的影响截然不同,这种不同不仅仅局限在人口的迁出与迁入这一层面上。以移民迁入河陇来说,学者们所热衷于讨论的永嘉移民使中原学术转移保存于河陇说,实际上是对陈寅恪学术观点的误读。陈寅恪先生所论是指文化重心转移而非移民所带来的文化之转移。而河西士人东迁平城后,又因他们的境遇很差,对北魏的贡献也大打折扣。相反的,河西士族被竭泽式的迁出,对于河陇,特别是对河西学术的影响却是灾难性的,河陇地域学术五百多年以来所形成的士族模式和地域格局因之发生了转折。     

Lime render layers: An overview of their properties

Lime renders are of great importance not only to enhance the appearance of the buildings, but also to protect and preserve old masonries. They constitute a specialized system, composed of several layers, in which each of them depends on the others and carries out some specific functions in order to assure a suitable performance of the whole. Knowledge of the traditional materials and techniques, as well as the know-how, is one of the key points in the maintenance and conservation of lime renders and, by extension, of our Heritage. However, the promotion of the use of cement and the industrialization process, which in the case of Spain took place about the 1960's, caused lime mortars to fall into disuse. In this article, classical treatises as well as the state-of-the-art researches were analysed to compile the properties of lime render layers, on the whole. The knowledge of these characteristics is essential to maintain and repair the existing renders as well as to formulate new compatible ones, while assuring their durability and appropriate performance. Lime is the selected binder for these recommendations because it was widely used as drawn from the literature.     

Historical coastal urban landscapes digital documentation and temporal study with 2D/3D modeling functionality: The case of Thessaloniki,Greece

The study refers to the visual representation of the coastal front of the historical center of Thessaloniki in northern Greece and its changes that have occurred through the years. Most of the old town was destroyed by fire on August 18, 1917. A few years later, the French architect and archeologist Ernest Hébrard proposed the reconstruction of the city centre, but his plans were never fully implemented. Since then, a series of interventions changed the form of the old town and consequently the coastal cityscape. The research was initially based on the photogrammetric processing of archive aerial images (1938) of Thessaloniki's city centre. Besides the vertical images, high oblique aerial images dated back to 1932, proved to be a significant source of information. A rich archive of old photographic material, sketches, drawings and gravures of the coastal forehead of the city was also used. Ortho-images of the coastal front, derived from laser scanning (2010), and a 3D model of the historical city center, derived from the stereo photogrammetric process of aerial images (1990), contributed decisively at the multi temporal study of the city front. The main outcomes of the present documentation study are the 3D representation (at scale of 1:200, accuracy 5 cm) of temporal changes of a part of the coastal front of the historical center of Thessaloniki and the 2D representation (at scale 1:100, accuracy 1–2 cm) of these changes with respect to variations on skyline, lacunas, interventions in old buildings, etc.     

Investment in early American art: the impact of transaction costs and no-sales on returns

Art, along with other “treasure assets,” has become a central object for investment opportunities. Investment return studies using hedonic and resale price regressions on different artistic periods and styles produce estimates of varying rates of return, predominately low rates with high standard deviations. The present study employs a new sample of American art sold at auction between 1987 and 2011—art created before 1950 by 33 artists born prior to 1900. Our study, unlike those that preceded it, considers works that are no-sales (those “bought-in” for failing to sell at auction at or above a predetermined and negotiated minimum price), in addition to full transaction costs—buyers and sellers premia on hammer prices. We conclude that investment return calculations are biased upward and may be negative when these factors are considered and that the “consumption utility” of art may be higher than previously thought. However, using a variant of the capital asset pricing model, we find that investment in early American art may still be desirable in a diversified portfolio of assets for when the price of stock assets falls, the price of art does not fall in the same proportion.     

快文化《杰克逊传》成功内幕

2009年6月26日,美国摇滚巨星迈克尔·杰克逊突然去世。 当天下午,现代出版社总编辑臧永清和编辑们确定迈克尔·杰克逊传记的图书选题;30日,责任编辑拿到了《杰克逊传一天堂里的太空步》样书;从7月1日起,这本新书就在网上预售;7月3日,该书在北京王府井新华书店上架。