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361.
Hans-Rolf Gregorius 《Ecological modelling》2012,224(1):1-10
Particularly in ecological and evolutionary genetics, methods of discerning complex traits are improving at a considerable rate. As a consequence, the resolution of intrinsically qualitative traits such as species affiliation or genetic type is increasing to degrees that blur their distinction from continuously varying characteristics. The common notion of diversity, however, relies on distinct features such as the states of qualitative traits, and it aims to assess variation as a counting of these features or types. This situation brings up the question of whether and how the diversity perspective of variation can be broadened to cover higher levels of complexity without sacrificing its concept. The present paper suggests two approaches that refer to established criteria for measures of diversity and that complement each other. The partitions approach treats complexity through general measures of difference between trait states, and the relations approach rests on general binary relations that capture structural aspects of diversity. Both approaches are shown to consistently imply effective numbers of types even in cases where distinct types are not explicitly specified. Practically all of the common methods of measuring diversity can be classified into either of the two approaches, and new opportunities for analyses of the diversity of complex traits are provided. The latter analyses include those of diversity in subdivided collections. Other perspectives of variation (such as dispersion, variances, etc.) are discussed and analyzed for their distinction from the diversity perspective. In many cases, the distinction can be made apparent with the help of diversity portraits. 相似文献
362.
Since gas plants are progressively increasing near urban areas, a comprehensive tool to plan maintenance and reduce the risk arising from their operations is required. To this end, a comparison of three Risk-Based Maintenance methodologies able to point out maintenance priorities for the most critical components, is presented in this paper. Moreover, while the literature is mostly focused on probabilistic analysis, a particular attention is directed towards consequence analysis throughout this study. The first developed technique is characterized by a Hierarchical Bayesian Network to perform the occurrence analysis and a Failure Modes, Effects and Criticality Analysis to assess the magnitude of the adverse outcomes. The second approach is a Quantitative Risk Analysis carried out via a software named Safeti. Finally, another software called Synergi Plant is adopted for the third methodology, which provides a Risk-Based Inspection plan, through a semiquantitative risk analysis. The proposed study can assist asset manager in adopting the most appropriate methodology to their context, while highlighting priority components. To demonstrate the applicability of the approaches and compare their rankings, a Natural Gas Regulating and Measuring Station is considered as case study. The results showed that the most suited method strongly depends on the available data. 相似文献
363.
364.
Tatiana M. Tsagaraki George PetihakisKostas Tsiaras George TriantafyllouManolis Tsapakis Gerasimos KorresGeorge Kakagiannis Constantin FrangoulisIoannis Karakassis 《Ecological modelling》2011,222(14):2512-2523
An ecosystem modelling approach was used in two areas of the Eastern Mediterranean in order to examine the effects of aquaculture on the ecology of the water column. Aquaculture expansion to meet demands of a growing population is followed by concerns about keeping impacts within socially acceptable limits. Primarily the study aimed at investigating the fate of nutrients from finfish culture and evaluating changes in chemical and biological characteristics of the water body. The model used, Aquaculture Integrated Model (AIM), is based on a complex generic biogeochemical model coupled to a 3D hydrodynamic model. Selected areas included a finfish farm in the Northern Aegean, Greece and an aquaculture development area in Vassiliko, Cyprus. Ecosystem effects were evaluated on the basis of scale and importance. Scenarios under different production levels and hydrodynamic conditions were explored at the sites. Model results showed that farm discharges are rapidly dispersed from their point source in addition to a tendency for effluents to accumulate at distances not normally associated directly with farming activity. The wide range of parameters available in the model helped identify parameters more likely to be affected by the farming activities. There was a satisfactory correlation between observed and predicted model outputs. This study demonstrates the importance of approaching aquaculture impacts at an ecosystem level and the utility of a modelling tool to this end. 相似文献
365.
366.
黄耀杰 《中国安全生产科学技术》2011,7(12):197-202
职业健康安全管理体系在煤炭行业获得了广泛认可和应用,对提高煤炭行业的职业健康安全管理水平起到了较大的促进作用.OSAS18001、ISO9001与ISO14001等管理体系标准均推荐采用过程方法,但煤炭行业鲜有应用.为了更好地在煤炭行业职业健康安全管理体系中贯彻过程管理模式,本文从TS煤矿职业健康安全管理体系的建立与运行、过程分析以及审核方法等方面入手,结合TS煤矿的实际,介绍了过程方法在煤矿职业健康安全管理体系中的应用. 相似文献
367.
宋传平 《中国安全生产科学技术》2011,7(4):156-159
实践表明,在投送的过程中谁能有效地对交通线进行控制与使用,谁的胜数就大,反之就会陷入被动的局面。袭击、封锁和破坏我方交通运输是客观存在的。而适时展开整体防卫,统一使用军地防空力量实行一体化区域防空,加强电磁频谱装备建设和技术安全保障,加强主要投送装备的自卫火力和电子对抗系统,就能使投送力量具有一定的防护能力,从而提高投送装备安全保障的水平。 相似文献
368.
Although the application of complex integrated models to wastewater systems is useful, it is often difficult to implement and not always suitable for the design of new systems or for their rehabilitation. Integrated simple approaches that allow assessing the environmental performance of urban wastewater systems may be advantageous, especially during the initial phases of the system planning process. This paper presents an original, straightforward approach that can be used for planning, design and operation of urban wastewater systems. The INtegrated Simplified Approach (INSA) combines the concepts of performance indicators with mass balances and can be applied to wastewater systems as a management support tool, particularly in situations where there is lack of data, economic limitations or time constraints. The INSA was applied to the Algés-Alcantara wastewater system to evaluate its environmental performance and to simulate the individual or combined impact of the rehabilitation measures proposed, thus defining their priority. The results clearly indicate that, despite the investment already made upgrading the wastewater treatment plant (WWTP), the proposed interventions must be implemented to ensure an acceptable environmental performance of the system. In addition, the results demonstrate the significant pollution loads present in stormwater, frequently higher than the pollution loads discharged into receiving waters during dry weather. 相似文献
369.
Many countries in sub‐Saharan Africa have adopted similar approaches to tackle the challenges of rural water supply, including community‐based management, community participation and the demand‐responsive approach. These are often combined with nationwide programmes of capacity‐building and decentralization. This paper first shows how Uganda has adopted these approaches in its rural water supply programme. Based on Government documents, we construct an organizational framework that illustrates the overall programme and outlines the roles and responsibilities which actors are expected to fulfil. Second, based on interviews with sector staff and a review of Government documents, the paper examines challenges to successfully “walk the talk”; that is, it provides insight into challenges affecting programme implementation. Among numerous difficulties, two key issues are highlighted: local political interference and the weak capacity of local governments. Concerning local political interference, local planning processes need to be reformed so that local politicians commit more strongly to improving water supply. Regarding local government capacity, the Government department responsible for the programme has established eight regional units that provide support to local governments. This promising strategy, combined with more appropriate engagement and the commitment of local politicians, should help to improve the implementation of the rural water supply programme in Uganda. 相似文献
370.
The policy instruments that provide information on a firm’s or facility’s environmental performance, such as the U.S. Toxic Release Inventory (TRI) and the Pollutant Release and Transfer Register system (PRTRs) used in some European countries and Japan, play an important role in encouraging firms or facilities to improve their environmental performance, if investors, consumers and residents recognize their environmental performance. This study uses a hedonic approach to explore how the Japanese rental housing market responds to carcinogenic risk arising from releases and transfers of chemical substances produced and used at close facilities. We found that residents do not perceive carcinogenic risk generated more than 1.0 km away from their residence and that they seem to recognize the increased carcinogenic risk at distances from 0.5 km to 1.0 km away; a 1% increase in carcinogenic risk reduces the average rent by 0.0007%. The distance at which residents perceive the risk arising from such facilities is less than in previous studies. This suggests that the risk perception recognized in previous studies may capture the other externalities in addition to the chemical risk because the risk is measured by the distance. 相似文献