双基球扁药工艺优化仿真研究

目的优化双基球扁药成球工艺参数,解决由于目前双基球扁药理论研究不充分、控制模型不明确、生产工艺参数调控依靠人工经验所导致的药品成球后直径、弧厚偏差大的问题。方法利用BP神经网络在处理复杂非线性映射问题上的强大的能力,对成球关键工艺参数与成球质量指标进行建模,并应用成球工艺过程仿真数据对其进行训练,将训练得到的BP神经网络模型用于优化成球工艺参数。同时利用仿真数据进行检验模型的可靠性。结果训练后BP神经网络均方误差为0.001,成球直径误差率为1.27%,成球弧厚误差率为2.08%,成球质量参数误差均很小,可以满足工艺要求。结论该BP神经网络模型具有较高精度,适用于含能材料工艺优化,提出的成球工艺优化方法能有效降低成球试制成本,缩短生产周期。     

Phased sampling for soil remediation

In phased sampling, data obtained in one phase is used to design the sampling network for the next phase. GivenN total observations, 1, ...,N phases are possible. Experiments were conducted with one-phase, two-phase, andN-phase design algorithms on surrogate models of sites with contaminated soils. The sampling objective was to identify through interpolation, subunits of the site that required remediation. The cost-effectiveness of alternate methods was compared by using a loss function. More phases are better, but in economic terms, the improvement is marginal. The optimal total number of samples is essentially independent of the number of phases. For two phase designs, 75% of samples in the first phase is near optimal; 20% or less is actually counterproductive.The U.S. Environmental Protection Agency (EPA) through its Office of Research and Development (ORD), partially funded and collaborated in the research described here. It has been subjected to the Agency's peer review and has been approved as an EPA publication. The U.S. Government has a non-exclusive, royalty-free licence in and to any copyright covering this article.     

广东省跨市河流边界水质控制断面方案讨论

在对广东省主要跨市河流进行详细调查的基础上，分析现有跨市河流边界水质控制断面的存在问题；综合考虑跨市河段的地理位置、水体现状功能及水环境敏感性等因素，并兼顾上、下游地区社会经济发展现状及趋势，建议在新丰江、增江、韩江、灞江、绥江、西南涌、西江干流、榕江、枫江等河道新设边界水质控制断面13个，在全省共布设38个断面，构成广东省跨市河流边界水质达标管理的监测体系。文章还建议，要尽快制定广东省跨市河流边界水质保护条例，为加强广东跨市河流边界水质的达标管理，解决上下游地区之问的污染纠纷提供法律依据。     

Objectives for Multiple-Species Conservation Planning

Abstract:  The first step in conservation planning is to identify objectives. Most stated objectives for conservation, such as to maximize biodiversity outcomes, are too vague to be useful within a decision-making framework. One way to clarify the issue is to define objectives in terms of the risk of extinction for multiple species. Although the assessment of extinction risk for single species is common, few researchers have formulated an objective function that combines the extinction risks of multiple species. We sought to translate the broad goal of maximizing the viability of species into explicit objectives for use in a decision-theoretic approach to conservation planning. We formulated several objective functions based on extinction risk across many species and illustrated the differences between these objectives with simple examples. Each objective function was the mathematical representation of an approach to conservation and emphasized different levels of threat. Our objectives included minimizing the joint probability of one or more extinctions, minimizing the expected number of extinctions, and minimizing the increase in risk of extinction from the best-case scenario. With objective functions based on joint probabilities of extinction across species, any correlations in extinction probabilities had to be known or the resultant decisions were potentially misleading. Additive objectives, such as the expected number of extinctions, did not produce the same anomalies. We demonstrated that the choice of objective function is central to the decision-making process because alternative objective functions can lead to a different ranking of management options. Therefore, decision makers need to think carefully in selecting and defining their conservation goals.     

简化活性污泥数学模型的优化

为了从控制运行的角度促进简化数学模型的应用，必须借助其它优化手段进一步提高预测精度。本文主要介绍了应用于简化数学模型的扩展卡尔曼滤波、神经网络和误差反馈系统三种优化方法以及优化后的验证结果。从验证结果来看，优化的ROM模型与ASMl模型的定性变化行为相似，基于神经网络的复合模型对PO4^3-和NOx^-的预测结果非常准确，误差反馈的优化系统模拟性能良好。     

The SITES reserve selection system: A critical review

Numerous models have been put forth to help with the growing demand for the establishment of biodiversity reserves. One site selection model that has been used in several recent studies is SITES [S.J. Andelman, I. Ball, F.W. Davis and D.M. Stoms, SITES V 1.0: an analytical toolbox for designing ecoregional conservation portfolios, Unpublished manual prepared for the nature conservancy, 1999, 1–43. (available at )]. SITES includes two heuristic solvers: based on Greedy and Simulated Annealing. We discuss the formulation of the SITES model, present a new formulation for that problem, and solve a number of test problems optimally using off-the-shelf software. We compared our optimal results with the SITES Simulated Annealing heuristic and found that SITES frequently returns significantly suboptimal solutions. Our results add further support to the argument, started by Underhill [L.G. Underhill, Optimal and suboptimal reserve selection algorithms, Biol. Conserv. 70 (1994) 85–87], continuing through Rodrigues and Gaston [A.S.L. Rodrigues and K.J. Gaston, Optimization in reserve selection procedures – why not?, Biol. Conserv. 107 (2002) 123–129], for greater integration of optimal methods in the reserve design/selection literature.     

Analyzing the factors affecting environmental risks of projects using a hybrid approach of DEMATEL‐ANP,artificial neural network: A case study

The increasing growth of the economy in each country necessitates a great amount of investment in infrastructure. The belief that projects involve various uncertainties, such as technical skills, management quality, and the like, indicates that most projects fail to achieve their aims, interests, costs, as well as their timeframes and space requirements. As the environment can pose significant uncertainty to any project, environmental risks should be deeply studied by project management departments. This study intends to analyze as a case the environmental risk management system within a consulting firm. From this analysis, each aspect of a project's environmental risk management is ranked using a fuzzy analytical network process (ANP), a neural network algorithm, and a decision‐making trial and evaluation laboratory (DEMATEL) methodology. From the organizational aspect, budget risk is the most significant. From the technical aspect, the risk of regulations is the most important one. Finally, the risk of project failure from poor communication is another identified main risk in this research. By studying high‐ranking items in this hierarchy, it can be understood that these criteria exist in different aspects; therefore, all aspects of the risk should be taken into account to cover and assess risk. A neural network algorithm for validating and reassessment of ranking is employed. Results of this application showed that, based on Spearman's rank correlation method, two different approaches resulted in similar rankings. Finally, some practical implications for responding to the most highly ranked risks are proposed.     

Social consequences associated with the use of various optimization methods in the protection of air quality

The fundamental tactics employed by the EU against air contamination, which are intended to maintain concentrations at a level that does not exceed the permissible values, usually entail considerable expense. To reduce this to a minimum, the procedure of economic optimization of air quality can be applied. When performed for a heavily polluted industrial city, it shows that it is possible to maintain concentrations below the threshold of air quality standards with relatively moderate expenditure. These evaluations also reveal that variations in population density distribution call into question the conventional wisdom that uniform air quality standards provide the best protection against air contamination for a whole region. On the contrary, an optimization that forces a drop in concentration to be evenly spread over the population, without reference to air quality standards, may lead to more efficient protection of human health and make no difference to overall expenditure.