河长制的得失、争议与完善

河长制从地方性实验到获得全国推广并正式写入法律,不过短短十年时间。河长制的成功之处在于解决了河湖管理保护"多龙治水"的困局,并调动了地方政府治水的积极性。但河长制也面临着高度依赖河长个人与考核制度的隐忧,其发展过程始终伴随着人治与法治之争、应急机制与长效机制之辩,以及重奖励轻惩罚、强化权力集中弱化公众参与的评价。提升与完善河长制可以从制度内与制度外两个方面着手:制度内的提升是指河长制内部机制的改良,包括考核制度的完善、公众参与水平的提高;制度外的提升是指与河长制配套的制度环境建设,包括环保行政队伍与行政执法力度的加强,以及与水环境治理相关的市场工具、政策工具与法律工具的综合 运用。     

A web-based Decision Support System for the optimal management of construction and demolition waste

Wastes from construction activities constitute nowadays the largest by quantity fraction of solid wastes in urban areas. In addition, it is widely accepted that the particular waste stream contains hazardous materials, such as insulating materials, plastic frames of doors, windows, etc. Their uncontrolled disposal result to long-term pollution costs, resource overuse and wasted energy. Within the framework of the DEWAM project, a web-based Decision Support System (DSS) application - namely DeconRCM - has been developed, aiming towards the identification of the optimal construction and demolition waste (CDW) management strategy that minimises end-of-life costs and maximises the recovery of salvaged building materials. This paper addresses both technical and functional structure of the developed web-based application. The web-based DSS provides an accurate estimation of the generated CDW quantities of twenty-one different waste streams (e.g. concrete, bricks, glass, etc.) for four different types of buildings (residential, office, commercial and industrial). With the use of mathematical programming, the DeconRCM provides also the user with the optimal end-of-life management alternative, taking into consideration both economic and environmental criteria. The DSS's capabilities are illustrated through a real world case study of a typical five floor apartment building in Thessaloniki, Greece.     

苏州地区雷电分布规律及对农村安全的影响

利用苏州地区2002年到2007年闪电定位系统监测资料,分析了该地区地闪空间和时间分布特征。结果表明,苏州市区、北部张家港地区是闪电频发的中心地带,太湖流域和苏州市区是强雷电流多发区。而就雷电的时间分布规律而言,苏州地区平均雷暴日的年变化基本上呈正态分布,在夏季达到峰值。闪击次数日变化呈双峰分布,上午10时左右是闪电最少时段,峰值出现在凌晨2时和下午19时,其中19时为日均最高值。夏季19时左右是该地区强对流天气最易发展成熟的时段。同时,还分析了苏州地区农村防雷的现状,发现造成目前雷灾频发的原因既有自然地理位置的因素,也有人为方面的原因,并针对农村安全提出了合理选择防雷设计参数和加强雷电预警预报工作两点建议.     

铁路行车事故预测方法分析与比较

对铁路行车事故的特点和类型进行分析;根据美国铁路2005年安全年报提供的数据,运用灰色系统理论和BP神经网络方法建立铁路行车事故的预测模型;利用MATLAB软件进行预测仿真,比较和分析两种预测方法的精度及特点。结果表明:灰色系统理论预测结果固定,短期效果比较好;BP神经网络预测具有适应性和灵活性,适用于长期预测。采用灰色系统理论和BP神经网络进行铁路行车事故的预测,克服了传统数学统计预测方法中建立复杂的数学模型,预测准确性低的缺点,对预防和控制铁路事故的发生,降低事故损失具有现实意义。     

2007年湖北省梅雨期可降水量的GPS观测和分析

介绍了湖北省2006年建成的GPS(全球定位系统)气象探测网对2007年梅雨期可降水量的探测,指出GPS探测的可降水量(〖WTBX〗PWV)〖WTBZ〗与探空资料所计算的可降水量具有高度的一致性。通过对多站GPS资料时间序列的分析,揭示了在梅雨期过程中〖WTBX〗PWV的3个阶段的变化特征：在梅雨期来临前PWV都有一个急升的过程,PWV的急升时间长短、升幅、量值大小反映了水汽累积情况,它与梅雨期降水过程有较好的对应关系;梅雨过程中PWV急升达到峰值的过程伴随着明显的降水,进入高值波动阶段后,降水继续维持,PWV下降的过程中,降水逐步减小,直至停止,在这一阶段中PWV时间序列的波动和空间分布特征与梅雨期降水的短时变化有较好的对应关系;PWV〖WTBZ〗的变化幅度和平均量值的平稳减小则反映梅雨期即将结束.     

Does projection into use improve trust and exploration? An example with a cruise control system

We know that the systems which are trusted by the users are more often used, especially in a risky situation where they need to delegate control, but we still ignore largely the factors which improve trust in the systems. Our issue here was to explore whether the way we present the system to the users will have an effect on their confidence in it.In this study, we had nine subjects using for the first time a cruise control system on open road; before, we present the system to them in three different ways: (i) a function-oriented written presentation (G1), (ii) a use-oriented written presentation, “augmented” with difficult situations (G2) and (iii) a use-oriented film presentation (3). They evaluate their trust in the system on scales before the whole experiment, after the presentation and after the real use. At the end, they also have self-confrontation interviews, where they see the video of their driving and describe their activity, strategies and feelings. We then develop quantitative and qualitative analysis of trust, linked with specific situations of action.Our results indicate that the presentation of instructions lowers the evaluation of trust (and of efficiency) that conductors have a priori; they had constructed an a priori representation of a CCS that is rather idealistic, and realised, after reading the instructions, and above all after having watched a film, that its use is not so obvious as they had previously thought There is thenceforth a drop in trust that nevertheless goes up again after use of the system during driving We remark, from qualitative analyses of use experience of the regulator in real driving conditions, that this drop in trust in the system does not inhibit subjects in their use, and in particular, for subjects who have watched a film of projection into use They know more of the functions of the system in driving conditions, they produce less distorted reconstruction of the functioning, and they have a deeper level of understanding of the system.     

水资源项目治理的社会网络动态分析

水资源项目治理中的利益相关方之间相互作用而形成关系网络,这种网络结构会随着项目生命周期发生变化,目前基于单阶段静态网络的研究难以满足这种动态治理角色网络分析的需要。科学合理的分析项目治理社会网络的动态变化,引导其健康发展对提高利益相关方之间的合作水平,进而提高项目成功率意义重大。本文以某大型水资源信息系统项目为例,综合应用社会网络分析与系统动力学方法,分析水资源项目治理社会网络的动态变化过程,构建系统动力学模型,对大型水资源项目系统结构进行仿真模拟,通过敏感性分析,探索控制项目治理风险的有效途径。     

地铁列车运行引起的环境振动评价

随着城市地铁建设的快速发展,地铁运行引起的环境振动问题引起了社会的广泛关注。以软件ABAQUS为计算平台,给出了模拟地铁列车振动荷载的表达式;采用修正Martin-Seed-Davidenkov动粘弹塑性本构模型描述土的动力特性;分析了地铁列车运行引起的地表振动特性;以地表振动加速度振级表征地表振动强度,对地表振动强度进行了分析和评价,为地铁线路选线和地铁沿线邻近建(构)筑物的减隔振设计提供一定的依据。     

Characterizing the Relative Contributions of Large Vessels to Total Ocean Noise Fields: A Case Study Using the Gerry E. Studds Stellwagen Bank National Marine Sanctuary

In 2006, we used the U.S. Coast Guard’s Automatic Identification System (AIS) to describe patterns of large commercial ship traffic within a U.S. National Marine Sanctuary located off the coast of Massachusetts. We found that 541 large commercial vessels transited the greater sanctuary 3413 times during the year. Cargo ships, tankers, and tug/tows constituted 78% of the vessels and 82% of the total transits. Cargo ships, tankers, and cruise ships predominantly used the designated Boston Traffic Separation Scheme, while tug/tow traffic was concentrated in the western and northern portions of the sanctuary. We combined AIS data with low-frequency acoustic data from an array of nine autonomous recording units analyzed for 2 months in 2006. Analysis of received sound levels (10–1000 Hz, root-mean-square pressure re 1 μPa ± SE) averaged 119.5 ± 0.3 dB at high-traffic locations. High-traffic locations experienced double the acoustic power of less trafficked locations for the majority of the time period analyzed. Average source level estimates (71–141 Hz, root-mean-square pressure re 1 μPa ± SE) for individual vessels ranged from 158 ± 2 dB (research vessel) to 186 ± 2 dB (oil tanker). Tankers were estimated to contribute 2 times more acoustic power to the region than cargo ships, and more than 100 times more than research vessels. Our results indicate that noise produced by large commercial vessels was at levels and within frequencies that warrant concern among managers regarding the ability of endangered whales to maintain acoustic contact within greater sanctuary waters. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.