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971.
Valery F. Venda Svyatoslav A. Chachko 《International journal of occupational safety and ergonomics》2013,19(2):93-108
Based on ergodynamics and the hybrid intelligence theory, an analysis of the nuclear power plant operator’s performance is given at the levels of strategies, tactics, and actions. Special attention is paid to the strategies used in the course of severe accidents at nuclear power plants. Data from Ukrainian and Russian power plants and training centres and from accidents around the world were collected and processed. It is shown that in an emergency it is essential for the human operator to be flexible. This flexibility includes two main training and personal factors: a large set of strategies and tactics the operator manages to use, and quick transformations between the strategies (tactics). It was also found that some emergency tasks are too complicated: They require simultaneous use of different strategies, with time strictly limited by nuclear power plant dynamics. Those tasks cannot be successfully solved by any individual operator. Hybrid intelligence systems involving different specialists should be used in those cases in order to avoid failures in emergency problem solving. 相似文献
972.
LEONARD EVANS 《Traffic injury prevention》2013,14(1):5-23
While antilock braking systems (ABS) have been convincingly demonstrated to enhance test track braking performance, their effect on crash risk in actual driving remains less clear. This paper examines how ABS influences crash risk using mainly two published studies which used police-reported crashes. The published findings are augmented by including new data and additional results. All the work is based on seven General Motors (GM) passenger vehicles having ABS as standard equipment for 1992 models but not available for 1991 models. The ratio of crashes under an adverse condition (say, when the pavement is wet) to under a normal condition (say, when the pavement is dry) is compared for ABS and non-ABS vehicles. After correcting for such factors as model year effects not linked to ABS, the following associations between ABS and crash risk were found by averaging data from the five states Texas, Missouri, North Carolina, Pennsylvania and Indiana (the errors are one standard error): a (10 ± 3)% relative lower crash risk on wet roads compared to the corresponding comparison on dry roads; a (22 ± 11)% lower risk of a pedestrian crash compared to the risk of a non-pedestrian crash; a (39 ± 16)% increase in rollover crash risk compared to the risk of a non-rollover crash. Data from the same Ave states were used to examine two-vehicle rear-end collisions. Using the assumption that side-impact crashes estimate exposure, it was found that for wet roads ABS reduces the risk of crashing into a lead vehicle by (32 ± 8)%, but increases the risk of being struck in the rear by (30 ± 14)%. The results from this study and from all available reported studies are summarized in tabular form. 相似文献
973.
Integrated smelter-refineries play an important role in the recovery of multiple metals from complex primary and secondary materials, and hence in closing metals cycles. Processes in these facilities are strongly interconnected, dynamic, and multifunctional, which challenges a typical representation in life cycle assessment (LCA). This is especially true when LCA is applied to calculate the environmental profile of single metals products.This study examines methodological requirements for assessing complex co-product systems using attributional LCA through a static, gate-to-gate inventory model that quantifies the environmental impacts of each of the metal products of an integrated precious metals smelter-refinery. The model is based on a large number of subprocesses and is formulated using detailed industry data, which allows quantification of the sensitivity of the results with respect to allocation rationales and the data collection period.The results within one impact category vary strongly among metals (up to four orders of magnitude for copper compared to rhodium). Moving from mass- to value-based allocation changes the result for a given metal by up to two orders of magnitude. If value-based allocation is used, the selected reference year for metals prices influences the results by up to a factor of two.Allocation rationales are critically analyzed, and it is shown that none reflect the business model or other system drivers. While the model is focused on quantifying environmental impacts of metal outputs, the actual process is economically driven to efficiently treat a continuously changing feed mix. The complexity of a smelter-refinery cannot be captured by static, attributional inventory models, which is why the choice of allocation rationale remains arbitrary. Instead, marginal, parameterized models are needed; however, such models are substantially more time and data intensive and require disclosure of more detailed, process specific data. 相似文献
974.
Stephanie L. Johnson David R. Maidment Mary J. Kirisits 《Journal of the American Water Resources Association》2013,49(4):838-850
Bacterial contamination accounts for more than 60% of the impairments included on the 2008 Texas 303(d) List. Many of these bacterial impairments are along the Texas Gulf Coast because coastal waters often are regulated for oyster harvesting, which have strict water quality standards. Under the Clean Water Act, each one of these impaired waterbodies requires a total maximum daily load (TMDL) study to be performed. A recent, statewide study recommended the development and application of simple modeling approaches to address the majority of Texas's bacteria TMDLs, including “… simple load duration curve, GIS [geographic information systems], and/or mass balance models.” We developed the TMDL Balance model in response to this recommendation. TMDL Balance is a steady state, mass balance, GIS‐based model for simulating pollutant loads and concentrations in coastal systems. The model uses plug‐flow reactor and continuously‐stirred tank reactor equations to route spatially distributed point and nonpoint source loads through a watershed via overland flow, non‐tidal flow, and tidal flow, decaying the loads via first‐order kinetics. In this paper, we explain the development of the watershed loading portion of the TMDL Balance model, demonstrating the methodology through a case study: computing bacterial loads in the Copano Bay watershed of southeast Texas. The application highlights an example of distributing bacterial sources spatially based on land use data. 相似文献
975.
MacMynowski DP 《Environmental management》2007,39(6):831-842
The conceptual rubric of ecosystem management has been widely discussed and deliberated in conservation biology, environmental
policy, and land/resource management. In this paper, I argue that two critical aspects of the ecosystem management concept
require greater attention in policy and practice. First, although emphasis has been placed on the “space” of systems, the
“time”—or rates of change—associated with biophysical and social systems has received much less consideration. Second, discussions
of ecosystem management have often neglected the temporal disconnects between changes in biophysical systems and the response
of social systems to management issues and challenges. The empirical basis of these points is a case study of the “Crown of
the Continent Ecosystem,” an international transboundary area of the Rocky Mountains that surrounds Glacier National Park
(USA) and Waterton Lakes National Park (Canada). This project assessed the experiences and perspectives of 1) middle- and
upper-level government managers responsible for interjurisdictional cooperation, and 2) environmental nongovernment organizations
with an international focus. I identify and describe 10 key challenges to increasing the extent and intensity of transboundary
cooperation in land/resource management policy and practice. These issues are discussed in terms of their political, institutional,
cultural, information-based, and perceptual elements. Analytic techniques include a combination of environmental history,
semistructured interviews with 48 actors, and text analysis in a systematic qualitative framework. The central conclusion
of this work is that the rates of response of human social systems must be better integrated with the rates of ecological change. This challenge is equal
to or greater than the well-recognized need to adapt the spatial scale of human institutions to large-scale ecosystem processes and transboundary wildlife. 相似文献
976.
Use of GIS in siting stabilization pond facilities for domestic wastewater treatment 总被引:1,自引:0,他引:1
Gemitzi A Tsihrintzis VA Christou O Petalas C 《Journal of environmental management》2007,82(2):155-166
Geographic information systems (GIS) use is presented in the problem of sitting areas for construction of natural systems such as stabilization ponds (SPs) for domestic wastewater treatment. For this purpose, several variables, such as topography, land use, type of geological formation, distance to major rivers or lakes, distance to existing cities and villages, existence of environmentally protected areas, mean minimum monthly temperatures and required wastewater effluent characteristics were analyzed with the GIS, in order to accept or reject a particular area within a region. The method is applied in the region of Thrace (Northeast Greece) at the municipal level. The required area for SP systems was calculated in each of the 36 municipalities of Thrace (including two islands, Thassos and Samothraki) as a function of the population of each municipality, temperature and local wastewater effluent discharge criteria. Based on the GIS analysis, suitable locations were identified in each municipality first, and then the total required surface area of these systems was compared to the available surface area of each municipality, in order to decide whether SP systems could be a viable solution to the wastewater management problem in the particular region. In that way the present methodology offers a fast and simple method to check the suitability of new areas for construction of such systems. 相似文献
977.
978.
李竞 《中国安全生产科学技术》2012,8(4):81-86
首先介绍了公共报警通知系统的背景知识和重要意义.以发达国家和我国建设的一些公共报警通知系统为例,对公共报警通知系统的发展现状进行概述,并分析了现有技术方案的一些不足之处.在介绍了分址调频广播技术的基础上,对分布式广播报警通知控制软件的设计与实现进行了详细说明.该软件通过互斥量的方法解决了硬件资源和广播资源的访问冲突问题;通过超时重发指令的方式解决了网络通信中可能存在的指令数据包丢失问题;通过设置超时时间,自动识别发生网络故障或者设备故障的发射塔;在无需人工干预的情况下,自动重新控制恢复正常功能的发射塔.该软件实现了多个客户端对多个广播报警发射基站的高效、正确、和分布式控制,极大的发挥了基于分布式分址调频广播技术的公共报警通知系统的优点.该软件系统与配套的分布式分址调频广播硬件系统一起,形成了一种覆盖范围广、环境适应性强、分区报警控制灵活的公共报警通知系统,技术路线成熟,推广前景广阔. 相似文献
979.
980.
Sherman Lewis 《国际发展与全球生态学杂志》2018,25(2):152-165
At high densities, land uses get close enough to each other to support walk, bike, and transit modes above 60% of total trips. The San Francisco Bay Area census was used to define five density levels: rural, exurban, suburban, central city, and urban core. The urban core definition, over 50 persons per neighborhood acre, is much denser than in other research. The California Household Transportation Survey supplied new data on block group area, population, trip stages, trip distances, trip time, and travel mode by density. The National Household Transportation Survey supplied block group population, density, travel mode, and income data. Both sources show a strong nonlinear relationship going from rural to urban core: auto miles and trips decrease as walk and transit miles and trips increase. With density, people travel fewer miles and spend less time traveling. High-income households in dense areas travel far fewer miles than those living at higher densities. With sufficient density, complementary features play a role in furthering mode shift. For planning purposes, the need for parking greatly declines. The findings are a basis for similar research elsewhere on high densities and complementary features. 相似文献