Assessing the efficiency of Chilean water and sewerage companies accounting for uncertainty

Efficiency assessment of water and sewerage companies (WaSCs) has attracted considerable attention both for water company managers and water regulators. Within the methodological approaches that can be applied to estimate efficiency scores, data envelopment analysis (DEA) is the most widely applied technique. In spite of the positive features of DEA, it presents a major drawback which is its deterministic nature. In other words, conventional DEA models do not account for uncertainty in the data. To overcome this limitation, we assess, for the first time, the efficiency of a sample of Chilean WaSCs by using a DEA model with statistical tolerance in the data. Hence, 81 efficiency scores are estimated for each WaSC rather than a single score as with conventional DEA models. The results illustrate that outputs exhibit larger uncertainty than inputs. Moreover, WaSCs efficiency scores change significantly under the best-case and worst-case scenarios. The ranking of the WaSCs allows for the identification of which of them has the highest performance based on their efficiency scores. This information is essential to enhance efficiency and innovation in the water industry. Moreover, the introduction of uncertainty in the efficiency assessment allows for the prediction and ranking of future performance of WaSCs.     

Referee analyses: A better approach than data validation

Data validation, as prescribed in guidance documents provided by the United States Environmental Protection Agency (EPA), yields legal evidence that an analytical laboratory has performed analyses according to predetermined specifications. This validation process, because it involves only the checking of procedural documentation, provides minimal information concerning the technical validity of the data. Unfortunately, in the minds of many, the performance of such a data validation has become synonymous with technical validity. A better approach is to implement a routine program of referee analyses. That is, submit a predetermined number of samples from the project to a second laboratory. A routine program of this type provides a self-checking and self-correcting mechanism for determining whether data are technically valid. Publication No. 3874, Environmental Sciences Division, ORNL. Managed by Martin-Marietta Energy Systems, Inc. for the US Department of Energy under Contract No. DE-AC05-840R21400.     

城市地铁安全施工第三方监测的研究与实施

实施城市地铁施工第三方监测是保证施工安全和工程质量十分重要的举措 ,有效地避免了施工过程中可能发生的事故。笔者以深圳地铁一期工程为例 ,详细阐述该工程中实施第三方监测的内容、第三方监测分析管理信息系统的研究和开发 ,包括地铁施工过程中对线路及沿线两侧建筑物倾斜和沉降、道路及各种管线沉降、土体位移、水位变化、桥梁墩台位移、隧道收敛及拱顶下沉等进行及时的监测、分析和信息反馈 ,从地铁工程第三方监测分析管理信息系统的内容、主要功能、系统结构等方面论述该系统的设计及开发。第三方监测及其管理的信息化 ,对全国其他城市的地铁施工安全 ,具有借鉴作用。     

新型机车监控系统的研究

设计了一种基于GSM的机车监控系统。用无线电手机传输监控装置产生的原始数据至PC机 ,来达到实时监控机车运行状况的目的。实践表明 ,该系统简单灵活 ,传输可靠 ,具有良好的稳定性和可靠性。与现行车载监控装置相比 ,新型机车监控系统具有提高数据的实时性、减轻工作人员的劳动强度等优点     

A Profile and Management of the US Army's underground storage tanks

The US Army owns more than 10,000 underground storage tanks (USTs), many of which are old and may be leaking. The Resource Conservation and Recovery Act of 1976 required tank owners to collect and report data on them by May 1986. In order to manage the large amounts of information on its USTs, the Army developed a microcomputer-based data base system. The data base system is user friendly and allows the user to store, organize, and manipulate the UST data. A leak potential index (LPI) was also developed and calculated for each of the Army's USTs. The LPI is used to prioritize USTs so that those with higher LPIs can be monitored closely. A characteristic profile of Army USTs according to construction material, capacity, age, content, and LPI is presented in this paper.The opinions expressed in this paper are those of the authors and do not necessarily reflect the views of the US Department of the Army, nor does the mention of trade names or commercial products constitute endorsement or recommendation for use.     

Estimation of Emissions of γ-Hexachlorcyclohexane from the Great Lakes–St. Lawrence Ecosystem Using a Coupled Efficient Kalman Filter–Atmospheric Transport–Soil Model

An efficient linear Kalman filter has been combined with a coupled atmospheric transport and soil–air exchange model to determine organochlorine pesticides emissions on the regional scale. In this study, results of -HCH emissions from the Great Lakes–St. Lawrence ecosystem, estimated from the coupled model, are presented and discussed. A source receptor technique is used to identify a priori the locations of emission sources of -HCH, the emissions are then updated through a Kalman filtering procedure which minimizes the weighted difference between the predicted mixing ratios from the coupled model and the measured concentrations over the Great Lakes–St. Lawrence river region. Two experiments using the inverse algorithm are carried out. In the first experiment, the coupled atmospheric transport and soil–air exchange model is implemented to predict -HCH air and soil concentrations. Emissions are then updated every 12 days using the updated soil concentrations and emission factors. However, the updated emissions are not input into the coupled atmospheric transport and soil–air exchange model. On the other hand, in the second experiment the updated emissions are fed back to the coupled model, so that the model is reinitialized in each 12 days. The results from the inverse technique for the year 1995 have been compared with grided -HCH emission inventory in Canada, generated by emission factors. It is shown that the estimated emissions of -HCH are consistent with the measured emissions. It is found that the St. Lawrence valley has larger emissions of -HCH than the Great Lakes region, indicating an opposite distribution to the emission usage inventory, but in agreement with the measured -HCH concentration.     

持续提升环境社会检测数据质量工作探讨

分析了我国社会环境检测机构发展现状,指出由于政府监管体系尚不完善、环境监测服务市场低价竞争、社会环境检测机构缺乏社会责任意识以及环境监测专业技术人员缺乏等因素,环境社会检测数据质量无法得到保证。提出,进一步完善政府监督管理制度、健全环境监测行业自律约束机制、提升环境监测人员能力水平、规范信息公开范围4方面的社会环境检测机构监管工作建议,从而持续提升环境社会检测数据质量。     

环境监测自动监测系统信息共享技术研究

针对我国环境监测现状,分析了当前各地监测系统存在的环境监测信息综合处理困难及信息交换障碍等问题,结合国家不同层次对环境监测数据的需求及侧重点,分析了实现环境监测数据共享存在的问题,给出了信息共享元数据内容,介绍了科技部项目主要功能和设计方法及思路。最后对环境监测信息共享技术发展提出了自已的观点。     

多参数环境自动监测数据采集传输装置研究

为加强环境自动监测系统的建设,提供了一个支持多种类型现场信息宽接入的信息采集、支持有线和无线信息传输的开放式在线数据采集传输装置.装置用标准化的工控机作为控制核心,具备模拟信号、LonWorks信号、视频信号、RS-485信号输入接口,网络通信和GPRS远程通信方式,采用Windows操作系统和数据库技术,应用方便灵活,有助于提供有效、客观的现场环境信息,实现环境自动监测与管理.     

江苏省环境空气质量自动监测数采平台的集成方案

对江苏省环境空气质量自动监测的数采平台现状进行了分析，并就省控中心统一软件采集中心站数据平台，省控中心统一软件采集子站数据平台，以及省控中心统一子站数采软、硬件平台方案进行了比较，指出为实现对全省各子站数据的有效质量管理，省环境空气质量自动监测平台的集成必须实现从子站直接采集原始分析数据，而要实现真正意义上的空气监测子站广域网连接，应由目前的省控中心统一软件采集子站数据的平台向省控制中心统一子站数采软、硬件平台过渡。