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排序方式: 共有140条查询结果,搜索用时 62 毫秒
31.
分析了广州港西基污水处理厂的污水处理系统的结构和存在的问题,提出了基于集散控制系统的解决方案。  相似文献   
32.
通过2013年1月1日~2017年7月31日兰州市呼吸系统疾病逐日就诊资料和气象资料,采用分布滞后非线性模型(DLNM)方法,分析0~30d滞后影响,研究极端低温对不同年龄(<15岁、16~45岁、46~60岁、>60岁)和性别人群呼吸系统疾病就诊人次的影响.结果发现:日均最低温度对相对危险度(RR)的最大RR变化范围为0.89~1.41,变化趋势整体呈现出V字型,在低温附近,温度越低,RR越高;滞后0~4d,极端低温代表的冷效应影响最为显著;滞后5~19d,在日均最低温度0℃附近,出现新的峰值,冷效应对RR的贡献有所下降,热效应对RR的贡献完全消失;滞后20~30d,日均最低温度为-10℃时,出现RR最小值,0℃温度点附近维持RR峰值;滞后22d时,滞后影响完全消失.在极端低温条件下,呼吸系统疾病对低龄人群表现出长期滞后性和高发性,对高龄人群表现出短期滞后性.男性比女性患病的滞后效应更长,患病风险更大.  相似文献   
33.
为克服用于火情探测的传统中心化系统网络负载高、灵活性差、推理效率低等问题,提出了一种无线传感网络环境下基于分布式推理的火情探测系统。该系统依托局部模糊逻辑和知识驱动聚类技术,能够融合当前环境信息、被预测的环境信息(短期知识)和偏差环境信息(长期知识),进而生成针对火情的更加复杂和精细的推理结果。该系统采用Ⅱ型模糊逻辑模型,避免了Ⅰ型模糊逻辑模型在建模非确定性局部知识和动态环境时准确率较低的问题;此外,该系统采用知识驱动节点自动聚类策略,并引入选择概率机制,有效降低了网络负载并提升了对非确定性的建模能力。对真实数据集进行试验,与多款基于无线传感网络的火情探测系统的试验结果对比表明,该系统能够生成针对火情的更加复杂和精细的知识推理结果,而且显著减少了无线传感网环境承载的消息数量,提高了知识推理的即时性和准确性。  相似文献   
34.
We analyze a transboundary pollution differential game where pollution control is spatially distributed among a number of agents with predetermined spatial relationships. The analysis emphasizes, first, the effects of the different geographical relationships among decision makers; and second, the strategic behaviour of the agents. The dynamic game considers a pollution stock (the state variable) distributed among one large region divided in subregions which control their own emissions of pollutants. The emissions are also represented as distributed variables. The dynamics of the pollution stock is defined by a parabolic partial differential equation. We numerically characterize the feedback Nash equilibrium of a discrete-space model that still captures the spatial interactions among agents. We evaluate the impact of the strategic and spatially dynamic behaviour of the agents on the design of equilibrium environmental policies.  相似文献   
35.
ABSTRACT: In this study, remotely sensed data and geographic information system (GIS) tools were used to estimate storm runoff response for Simms Creek watershed in the Etonia basin in northeast Florida. Land cover information from digital orthophoto quarter quadrangles (DOQQ), and enhanced thematic mapper plus (ETM+) were analyzed for the years 1990, 1995, and 2000. The corresponding infiltration excess runoff response of the study area was estimated using the U.S. Department of Agriculture (USDA), Natural Resources Conservation Service Curve Number (NRCS‐CN) method. A digital elevation model (DEM)/GIS technique was developed to predict stream response to runoff events based on the travel time from each grid cell to the watershed outlet. A comparison of predicted to observed stream response shows that the model predicts the total runoff volume with an efficiency of 0.98, the peak flow rate at an efficiency of 0.85, and the full direct runoff hydrograph with an average efficiency of 0.65. The DEM/GIS travel time model can be used to predict the runoff response of ungaged watersheds and is useful for predicting runoff hydrographs resulting from proposed large scale changes in the land use.  相似文献   
36.
ABSTRACT: A significant portion of all pollutants entering surface waters (streams, lakes, estuaries, and wetlands) derives from non-point source (NPS) pollution and, in particular, agricultural activities. The first step in restoring a water resource is to focus on the primary water quality problem in the watershed. The most appropriate NPS control measures, which include best management practices (BMPs) and landscape features, such as wetlands and riparian areas, can then be selected and positioned to minimize or mitigate the identified pollutant(s). A computer-based decision sup. port and educational software system, WATERSHEDSS (WATER, Soil, and Hydro-Environmental Decision Support System), has been developed to aid managers in defining their water quality problems and selecting appropriate NPS control measures. The three primary objectives of WATERSHEDSS are (1) to transfer water quality and land treatment information to watershed managers in order to assist them with appropriate land management/land treatment decisions; (2) to assess NPS pollution in a watershed based on user-supplied information and decisions; and (3) to evaluate, through geographical information systems-assisted modeling, the water quality effects of alternative land treatment scenarios. WATERSHEDSS is available on the World Wide Web (Web) at http://h2osparc.wq.ncsu.edu .  相似文献   
37.
An improved implementation of distributed multiplier/fictitious domain method is presented for the direct numerical simulation of particulate flow. The key improvement is to replace a finite-element triangulation for the velocity and a “twice-coarser“ triangulation for the pressure with a rectangular discretization for the velocity and pressure. For code validation, the sedimentation of a single particle in a twodimensional channel was simulated. The results showed that the simulation is independent of the mesh size as well as the time step. The comparison between experimental data and this simulation showed that our code can give a more accurate simulation on the motion of particlesthan previous DLM code. The code was then applied to simulate the sedimentation of 600 particles in a rectangular box. The falling course ispresented and discussed. At the same time, this simulation also demonstrates that the method presented in this paper can be used for solving the initial problems involving a lager number of particles exaclly with computing durations kept at acceptable levels.  相似文献   
38.
介绍了因特摩实时智能监控及事故预报防范系统.该系统是基于因特网的实时集成分布式智能系统,能对生产过程和设备进行智能监控及对事故进行预报和防范.其超媒体显示空间分别用"公有知识显示窗口"、"私有知识显示窗口"和"实时反向推理启示窗口"为生产人员提供及时有效的操作指导.因特摩系统将人类智慧与机器智慧相集成,将私有知识和公有知识相集成,把知识集成系统(KIS)和信息处理自动化系统(如MIS和ERP系统)以及数据处理自动化系统(如DCS、PLC和SCADA系统)相集成,体现了诸多的新方法和新功能,在安全生产中发挥出了作用,实现了"信息化带动工业化,知识化推动信息化".  相似文献   
39.
Abstract

Makerspaces – open access design and fabrication workshops – provide new contexts for design practice through ‘distributed production’. The global community of makerspaces has evolved quickly and in turn, substantial hype is attributed to its potential for radical sustainable innovation. In this article, we explore this potential in the context of the new ‘circular economy’ agenda. We focus the research on the critical role of makerspace managers/founders who are recognised as gatekeepers to circular practices. The research method is action-led including expert interviews (academics and founders/managers) as well as two generative context-mapping workshops, run at selected makerspaces in collaboration with their founders/managers. We unearth everyday ‘how-to’ guidance to interweave circular practices within makerspaces from the outset by: fostering an enabling culture; building local connections; nurturing individual/community capacities; and stimulating practical know-how. However, while the research reveals immense opportunities to cultivate circular literacy from within makerspaces, the prospects to ask more profound questions about our economy, through makerspace practices, are found to be compromised by day-to-day concerns. The insights from this research can act as a starting point for future work in this emerging research area.  相似文献   
40.
吉林省松花江中下游污染物排放总量控制   总被引:1,自引:0,他引:1  
分析了实施总量控制的理论依据 ;并以此研究吉林省松花江中下游污染物总量控制以及吉林市控制单元的总量控制方案 ;最后探讨了总量控制措施。  相似文献   
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