隧道含水构造直流电阻率法超前探测研究

含导水构造和岩溶裂隙水的探查是亟需研究和解决的关键问题。直流电阻率法以其对低阻体反映敏感、分辨率高等优点被引入到隧道掌子面前方含水构造的预报工作中。首先,推导出了无限全空间中球体含水构造直流电法超前探测的解析解公式,并在利用有限元数值方法进行正演分析的基础上,借助“比较法”将含隧道腔体的三维空间中超前探测视电阻率数据转换为无限全空间中的数据,并探讨了由MN电极附近电阻率不均匀所造成的干扰以及识别和去除这种干扰的方法。然后,设计了基于全空间球体含水构造超前探测解析公式的阻尼最小二乘反演方法,对隧道中多组球体含水构造模型进行了较为成功的反演。另外,探讨了其他形状的有限体积的含水构造超前探测异常规律,提出了“等效球体”的概念,亦在全空间球体含水构造超前探测解析公式的基础上设计了快速反演方法。最后,利用物理模型试验验证了有限元数值正演方法和阻尼最小二乘反演技术的可行性和有效性,为实际工程中含水构造的直流电法超前预报奠定了基础。     

基于SVM回归模型的SAR图像有效波高估测

A new method for estimating significant wave height(SWH) from advanced synthetic aperture radar(ASAR) wave mode data based on a support vector machine(SVM) regression model is presented. The model is established based on a nonlinear relationship between σ0, the variance of the normalized SAR image, SAR image spectrum spectral decomposition parameters and ocean wave SWH. The feature parameters of the SAR images are the input parameters of the SVM regression model, and the SWH provided by the European Centre for Medium-range Weather Forecasts(ECMWF) is the output parameter. On the basis of ASAR matching data set, a particle swarm optimization(PSO) algorithm is used to optimize the input kernel parameters of the SVM regression model and to establish the SVM model. The SWH estimation results yielded by this model are compared with the ECMWF reanalysis data and the buoy data. The RMSE values of the SWH are 0.34 and 0.48 m, and the correlation coefficient is 0.94 and 0.81, respectively. The results show that the SVM regression model is an effective method for estimating the SWH from the SAR data. The advantage of this model is that SAR data may serve as an independent data source for retrieving the SWH, which can avoid the complicated solution process associated with wave spectra.     

The role of social norms on conservation programmes in shellfish fisheries

Ostrom (1990) has argued that in collective action problems, social factors are crucial in order to promote conservation. A survey instrument among shellfish gatherers has been used to analyse their preferences with respect to a proposed conservation management programme, assessing the effect of co-management initiatives and the impact of social norms on extraction. Results show that shellfish gatherers working in a Marine Protected Area (MPA) behave more conservatively with respect to their counterparts in terms of their current extraction patterns, promoting species conservation. With regards to social norms, expected believes about the fulfilment of the current extraction regulation in their network, allow for the acceptance of restrictions imposed by the conservation management plan without decreasing the shellfish gatherers’ utility in any significant way.     

测绘产品三维可视化系统的研发与应用

根据测绘产品的现状和实际迫切需求,结合多年的案例经验,对测绘产品的三维可视化系统所需的硬件和软件系统进行了研究和开发。详细分析了系统的技术和市场。笔者经过多年的开发和实施了多个成功案例,实践证明测绘产品的三维可视化系统得到了用户和市场的认可,产生了客观的经济效益。     

A new mapping of the world for the new millennium

A new mapping of the world derived from connections between cities is presented as a complement to the traditional world map of countries. Under conditions of contemporary globalization world cities have emerged as global service centres. These have been created by the location strategies of leading corporate service firms (e.g. in accountancy) in setting up their global office networks. Data on the offices of 46 global service firms in 55 world cities are used to define service connections between cities. Connections are converted into measures of network proximity and a multidimensional scaling is applied to these 'distances' to create a 'global service space' of cities. This new mapping of the world shows a distinctive centric structure with the major world cities (e.g. London) at the core. Investigation of this general structure reveals more subtle patterns of interacting regional and hierarchical tendencies.     

nhanced Destriping of Satellite Data of Ice Surface in Antarctica

This paper briefly reviews the cause of the striping and then develops a tapered (Chebwin & Kaiser) window finite impulse response (FIR) filter and a constrained least squares FIR filter by reason of the striping of ASTER satellite data . Both filters minimize the stripes in the visible data and simultaneously minimize any distortion in the filtered data. Finally, the results obtained by using these new filtering methods are quantitatively compared with those produced by other destriping methods.     

Measurement and interpretation of connectivity of Chinese cities in world city network, 2010

This is an empirical paper that measures and interprets the position of Chinese cities in the world city network in 2010. Building on a specification of the world city network as a′interlocking network′in which business services firms play the crucial role in city network formation, information is gathered about the presence of global service firms in cities. This information is converted into data to provide the′service value′of a city for a firm′s provision of corporate services in a 526(cities)×175(firms) matrix. These data are then used as the input to the interlocking network model in order to measure cities′connectivity and its predominant geographical orientation. Here we focus on the position of some key Chinese cities in this regard, and discuss and interpret results in the context of the urban dimensions of the′opening up′of the Chinese economy.     

Advances in active fire detection using a multi-temporal method for next-generation geostationary satellite data

ABSTRACT

A vital component of fire detection from remote sensors is the accurate estimation of the background temperature of an area in fire's absence, assisting in identification and attribution of fire activity. New geostationary sensors increase the data available to describe background temperature in the temporal domain. Broad area methods to extract the expected diurnal cycle of a pixel using this temporally rich data have shown potential for use in fire detection. This paper describes an application of a method for priming diurnal temperature fitting of imagery from the Advanced Himawari Imager. The BAT method is used to provide training data for temperature fitting of target pixels, to which thresholds are applied to detect thermal anomalies in 4?μm imagery over part of Australia. Results show the method detects positive thermal anomalies with respect to the diurnal model in up to 99% of cases where fires are also detected by Low Earth Orbiting (LEO) satellite active fire products. In absence of LEO active fire detection, but where a burned area product recorded fire-induced change, this method also detected anomalous activity in up to 75% of cases. Potential improvements in detection time of up to 6?h over LEO products are also demonstrated.     

地质资料图文光盘存储检索系统简介

有史以来,地质资料以纸质载体存储,以原始手工操作检索。为改变这一现状,地矿部推广的“地质资料图文光盘存储检索系统”,可实现地质资料管理现代化     

An Advanced Probabilistic Neural Network for the Design of Breakwater Armor Blocks

In this study,an advanced probabilistic neural network(APNN)method is proposed to reflect the global probability density function(PDF)by summing up the heterogeneous local PDF which is automatically determined in the individual standard deviation of variables.The APNN is applied to predict the stability number of armor blocks of breakwaters using the experimental data of van der Meer,and the estimated results of the APNN are compared with those of an empirical formula and a previous artificial neural network(ANN)model.The APNN shows better results in predicting the stability number of armor blocks of breakwater and it provided the promising probabilistic viewpoints by using the individual standard deviation in a variable.