Good deposits are not enough: Mining labor productivity analysis in the copper industry in Chile and Peru 1992–2009

Chile and Peru produce almost 45% of world’s mine copper output. This situation reflects their natural endowment and mining tradition, but is also the result of development processes undertaken over the last decades. As a result, both countries multiplied its mine copper production in more than 3 times in the last 20 years. Mining labor productivity played a central role achieving these amazing growth rates. Although there is a consensus about the relevance of this variable for the mining industry, the specific factors behind labor productivity changes are not completely understood.     

Recreation demand analysis under truncation, overdispersion, and endogenous stratification: an application to Gros Morne National Park

Using on-site survey data from Gros Morne National Park in Newfoundland, this paper estimates and compares several truncated count data models of recreation demand. The selected model accounts not only for the truncated and overdispersed nature of the data but also for endogenous stratification due to the oversampling of avid users. Moreover, the model that allows for a flexible specification of the overdispersion parameter dominates on the basis of goodness of fit. The results are used to estimate the users' value of access to the park.     

Data integration across borders: a case study of the Abbotsford‐Sumas aquifer (British Columbia/Washington State)1

Abstract: Integrating spatial datasets from diverse sources is essential for cross‐border environmental investigations and decision‐making. This is a little investigated topic that has profound implications for the availability and reliability of spatial data. At present, ground‐water hydrostratigraphic models exist for both the Canadian or for the United States (U.S.) portion of the aquifer but few are integrated across the border. In this paper, we describe the challenges of integrating multiple source, large datasets for development of a ground‐water hydrostratigraphic model for the Abbotsford‐Sumas Aquifer. Growing concerns in Canada regarding excessive withdrawal south of the border and in the U.S. regarding nitrate contamination originating north of the border make this particular aquifer one of international interest. While much emphasis in GIScience is on theoretical solutions to data integration, such as current ontology research, this study addresses pragmatic ways of integrating data across borders. Numerous interoperability challenges including the availability of data, metadata, data formats and quality, database structure, semantics, policies, and cooperation are identified as inhibitors of data integration for cross‐border studies. The final section of the paper outlines two possible solutions for standardizing classification schemes for ground‐water models – once data heterogeneity has been addressed.     

Revealing source signatures in ambient BTEX concentrations

Management of ambient concentrations of Volatile Organic Compounds (VOCs) is essential for maintaining low ozone levels in urban areas where its formation is under a VOC-limited regime. The significant decrease in traffic-induced VOC emissions in many developed countries resulted in relatively comparable shares of traffic and non-traffic VOC emissions in urban airsheds. A key step for urban air quality management is allocating ambient VOC concentrations to their pertinent sources. This study presents an approach that can aid in identifying sources that contribute to observed BTEX concentrations in areas characterized by low BTEX concentrations, where traditional source apportionment techniques are not useful. Analysis of seasonal and diurnal variations of ambient BTEX concentrations from two monitoring stations located in distinct areas reveal the possibility to identify source categories. Specifically, the varying oxidation rates of airborne BTEX compounds are used to allocate contributions of traffic emissions and evaporative sources to observed BTEX concentrations.     

一种基于混沌和魔方的数字图像置乱算法

在现有数字图像置乱算法的基础上,分别分析了这些算法存在的不足,详细介绍了混沌序列及其优点。在介绍魔方玩法的基础上,指出可以把对魔方的初始置乱理解成加密过程,并分析魔方的加密原理在数字图像置乱中应用的可能性。并设计了一种结合混沌和魔方优点的数字图像置乱算法。该方法将图像的行列和对角线定义成魔方变换的旋转面,将对魔方的旋转定义成旋转面的循环移动。置乱过程先根据密钥产生混沌序列,再由混沌序列控制魔方变换进行图像置乱。通过与其他算法的实验对比,表明该算法有较好的图像置乱效果,达到了对图像进行置乱的目的。分析表明,该算法的时间复杂度较低,安全性较高,满足实际的应用需要。     

重大危险源安全监管基础数据标准化研究

重大危险源安全监管必须依靠信息化技术,但我国缺乏相关的标准规范,各级安全监管信息系统互不兼容,形成信息孤岛。本文研究了重大危险源安全监管信息系统标准化建设的内容和需求,提出目前最急迫的是数据标准类规范。通过对安全监管政务的工作流程和内容的分析,应用全程一体化精细建模方法基于重大危险源政务模型提取了基础数据元,并研究了基础数据元与基于XML的数据交换规范的编制。     

Case study: examining the contribution of historical sources of lead in urban soils in Portland,Maine, USA

While the presence of lead in urban soils from residential lead paint and leaded gasoline is well documented, the relative contribution of lead from area historical industrial activities is not. This study examined the connection between historical industrial sources of lead in Portland, Maine, USA from 1860 to 1970 to current, spatial distributions of soil lead. Collecting 1859 surface and 122 sub-surface soil samples in accordance with USEPA's Lead Safe Yard Protocols, lead concentrations varied from 9 mg/kg to >100,000 mg/kg with most of the samples greater than USEPA's critical value for lead (400 mg/kg). Using historical documents, probable sources of lead were mapped. In comparing two datasets, no clear relationship emerged. Findings were hampered by inability to sample under large areas of impervious surfaces and private properties. Because of lead's immobility in soil, one would expect decreasing concentration with depth, but lead concentrations varied with depth and location. The haphazard dumping of lead-contaminated industrial waste and the relocation of contaminated fill are likely factors. These findings suggest that in urban areas where multiple historical sources of lead existed, surface sampling to determine presence of lead may not be sufficient to protect public health.     

面向国土空间规划实施监督的监测评估预警模型体系研究

国土空间规划监测评估预警是监督规划实施管理、保障规划实施成效的重要手段,也是实现“可感知、能学习、善治理、自适应”智慧规划转型的关键支撑。针对当前国土空间规划监测评估预警研究重机制、轻理论,以及缺乏一套科学可用的监测评估预警技术方法支撑的不足,在系统分析国土空间规划监测评估预警目标与内涵的基础上,构建以人工智能（Artificial Intelligence）、大数据（Big Data）、云计算（Cloud Computing）等新型信息技术(“ABC”技术）为支撑,覆盖国土空间规划“监测—评估—预警”业务全生命周期的应用模型体系,并结合信息系统建设案例,介绍了基于“ABC”技术的国土空间规划监测评估预警模型体系对实现各地国土空间规划“动态监测、精准评估、及时预警”的重要支撑作用。     

新疆空气质量日报网站数据传输管理系统的设计与实现

利用ASP.NET和ADO.NET技术开发的新疆空气质量日报网站数据传输管理系统,实现了网站空气质量日报的动态管理,同时依托该网站将沙尘暴天气应急监测数据传输系统作为其组成部分,使对新疆境内的区域大气质量监测数据的管理更加及时、高效,提高了工作效率,新疆的城市空气质量日报工作达到全国领先水平.本文对本系统的开发原理、系统的功能特点和设计方案进行了介绍.     

环境空气质量自动监测系统质量保证工作的探索

根据全国多个省市的环境空气自动监测质量保证工作的经验和做法,结合乌鲁木齐市环境空气自动监测质量保证工作实际情况,对点位设置要求、制度体系建立、仪器质量控制难点、数据审核与研判等环境空气自动监测质量保证工作的关键环节进行探索,为加强环境空气自动监测质量保证体系提供参考依据.