高光谱图像系统应用于模糊印章的提取研究

传统书画作品中存在有大量模糊不清的印章,对此类印章尚没有很好的手段进行提取和鉴别。为解决这一问题,本工作采用一种用高光谱图像系统采集书画中模糊印章的光谱-图像信息,采用最小噪声分离变换(MNF)处理光谱图像数据,提升了模糊印章的可辨识度。结果表明,采用该方法能够有效的将模糊印章的信息提取出来,有利于印章的鉴别和研究,为书画的文物价值和真伪鉴别的研究提供了科学有效的手段。     

Bruit aérien et équité environnementale dans les quatre plus grandes métropoles canadiennes

Previous environmental equity studies have examined the spatial distribution of aircraft noise across cities. Their findings show that, in several cities, visible minorities and low-income populations are most affected by aircraft noise. In contrast, one study concludes that well-off populations are the most affected. These contradictory findings support the use of a comparative approach for several cities. The aim of this study is twofold. First, we want to identify if there are groups in the population that are in a situation of inequity to aircraft noise exposure in Toronto, Montréal, Vancouver, and Calgary. Then, we want to check if the exposure to the aircraft noise of the different groups varies significantly from one metropolis to another. We use the recommended noise exposure contour maps in Canada: the Noise Exposure Forecasts. Next, four variables are extracted from the 2016 Statistics Canada census at a fine-scale level (dissemination areas): that is, the percentages of low-income, visible minorities, 0- to 15-year-old, and 65-year-old and over populations. The results of a mixed effects logistic regression model show that environmental inequities in terms of exposure to aircraft noise for the four population groups are not consistent from city to city.     

EMPIRICAL EVALUATION OF SITE EFFECTS BY MEANS OF H/V SPECTRAL RATIOS AT THE LOCATIONS OF STRONG MOTION ACCELEROMETERS IN ISRAEL

Acceleration data from local and regional earthquakes is of prime importance in evaluating the seismic hazard. Consequently, strong motion accelerometers are currently installed at more than 60 locations in Israel. We have explored the possibility of site amplification effects at 10 sites where local earthquakes triggered strong motion accelerometers by integrating empirical and analytical estimations. Implementing H/V spectral ratio techniques using 15 accelerograms from nine earthquakes, 105 seismograms shear-wave records of 35 local and regional earthquakes and seismograms of microtremors were used in the empirical evaluations. The subsurface models were constructed by integrating available geological and geophysical information at the analysed site with empirically evaluated site response functions. Amplification effects of factor 3-6 are observed at various frequencies in the 0.8-6.0 Hz band. Through the analysis process it became evident that the instant availability of many useful time windows of microtremors provides systematic estimations of the fundamental resonance frequency of each site and their associated amplification levels, which are similar to those obtained from H/V spectral ratios of seismograms and accelerograms and to those inferred from the subsurface geology. Analytical transfer functions should be reviewed with respect to empirical site response evaluations. Estimations that are based on only one approach may be totally misleading.     

Structural Identification of a Masonry Tower Based on Operational Modal Analysis

A wide program of structural assessment has been carried out by Politecnico di Milano on the historic bell tower of the church Chiesa Collegiata in Arcisate (Varese, northern Italy). Within this context, the first part of the article summarizes the results obtained from the application of the stochastic subspace identification method to ambient response data collected in two dynamic tests, carried out in June 2007 and June 2008. Next presented is the vibration-based methodology developed for the calibration of a three-dimensional finite element model of the tower, consisting in the successive application of systematic manual tuning, sensitivity analysis, and simple system identification algorithm.     

最小噪声分离变换与Haar小波变换结合的壁画线状特征增强方法

在壁画的保护与修复中,线状特征具有重要的意义。然而由于自然环境等因素的影响,壁画经常出现褪色残缺等病害,导致其线状特征难以辨认。因此,利用高光谱成像与Haar小波变换结合,提出了一种壁画线状特征增强方法。首先,对高光谱影像进行最小噪声分离(MNF)变换,选取前10波段进行MNF逆变换进行重构,实现高光谱影像的降噪处理。其次,对重构后的影像选择真彩色波段变换为灰度图像,对灰度图像进行Haar小波分解。然后,对最小噪声分离变换后的影像,利用最大平均梯度法进行最优波段选择,将最优波段利用Haar小波进行变换,利用其分解后的低频信号与灰度图像分解后的低频信号相融合,高频信号使用MNF逆变换重构后的灰度图像。最后,对优化组合的低频和高频信号进行Haar小波逆变换得到结果图像,达到增强线状特征的目的。经过与原始灰度影像、主成分分析线状特征增强方法对比,验证了线状特征增强方法的有效性。研究结果可为壁画的保护修复提供更丰富、更直观的参考信息。     

‘Lend me your ears’: social policy and the hearing body

Recent developments in music regulation policy in some European countries show a recognition of changes in the built environment, contemporary demographics and the sonic profile of popular music. These initiatives have not been echoed in Australian music policy, where the primary focus is on the cultural and economic conditions of production and consumption, with little interest in the mechanics and biology of sound production and circulation, and their social welfare implications. Within the general category of noise pollution, it appears that the proliferation of low-frequency noise (LFN) is the fastest growing problem, in which contemporary popular music is increasingly implicated. This paper explores why LFN should suddenly become so pervasive that it has begun to attract specific social policy and legislative measures, its own scientific journals, and attempts to establish standards of its measurement specific to a profile that evades traditional sound pollution analysis.     

Evaluating background noise: Assessing off-site data from field surveys around the Italic sanctuary of S. Giovanni in Galdo,Molise, Italy

Abstract

This study demonstrates the potential of intensive sampling and off-site analyses to identify evidence of human activity in the past using the off-site data collected around the Italic sanctuary of S. Giovanni in Galdo, Molise, Italy. Rather than employing general and monocausal explanatory models—e.g., large-scale erosion or ancient manuring—to account for off-site material, this study examines ceramic ware variability from surface collections within the local context. It reveals that the ceramic ware variability in samples from low density areas with low visibility can be an important indicator of past human activity. The results of this examination of background noise—or unexplained variability in off-site material—from the Sacred Landscape Project increase the number and types of sites recognized in the surface collections. Furthermore, the analysis reduces the amount of surface material that can be regarded as off-site material and thus changes its composition. The overall results shed new light on the origins of off-site material and whether it should be interpreted as evidence of human activity in historical landscapes.     

Amplifying Environmental Politics: Ocean Noise

Scientific evidence suggests that rising levels of anthropogenic underwater sound (“ocean noise”) produced by industrial activities are causing a range of injuries to marine animals—in particular, whales. These developments have forced states and development proponents into acknowledging ocean noise as a threat to marine economic activity. This paper delivers a Gramsci‐inspired critique of the modernizations of ocean noise regulation being wrought by science, state and politics. Gramsci was acutely interested in the dynamic and social nature of scientific research, and his writings affirm science's powers and ambitions. At the same time, he was keen to observe how science participates in the process he called hegemony. Using examples drawn from Canada's West Coast, I suggest that capital is engaging ocean noise not only as a regulatory problem issuing from legal duties and legitimacy concerns, but opportunities linked to the commercialization of ocean science.     

White noise: sound,materiality and the crowd in contemporary heritage practice

Sounds of our Shores was a joint venture between the National Trust and the British Library that employed a crowdsourcing methodology to create a permanent archive of British coastal sounds. In this paper I pursue a critical analysis of that project in order to problematise the recent emergence of practices aimed at capturing and preserving everyday sounds as ‘sonic heritage’. More broadly, I use the case study to think through two trends in contemporary heritage practice. These are, first, a turn towards crowdsourcing as a means of democratising representation, and, second, a current trend towards the accumulation and preservation of an ever-broader range and mass of materials as heritage. The framework for my analysis is provided by a dual reading of the term ‘white noise’. Thus, for my purposes, ‘white noise’ describes both an acoustic phenomenon (the product of every possible frequency sounding simultaneously; a sonic expression of perfect equality and perfect chaos), and a particular mode of racialised sound production and audition, modulated and constrained by whiteness. White noise displaces and silences its Others. The white ‘listening ear’, to borrow Jennifer Stoever-Ackerman's terminology, is either deaf to, or appalled by, the sounds those Others make.     

最小噪声分离(MNF)变换应用于模糊印章提取的研究

为了提高印章的可辨识度,尝试解决印章与画意重合的问题,应用高光谱图像系统,采集了上海博物馆馆藏"清明上河图"作品的高光谱图像信息,对其中三枚可辨识度不高,与画意重合严重的印章进行了提取。通过最小噪声分离(Minimum Noise Fraction,缩写为MNF)解决了其中一枚印章可识别度不高的问题;对与画意高度重合的两枚印章,通过波段裁剪结合最小噪声分离处理,有效地将印章与画意分离开,取得了令人满意的效果。结果表明,最小噪声分离可以有效地提高模糊印章的可辨识度,结合相应的波段裁剪处理,也可以有效地将印章与画意分离开。