人群疏散中"非适应性"行为的研究

本文从人与人的相互作用和社会学、心理学的角度,对人群疏散中“非适应性”行为的理论、计算机模型、模拟原理等进行了较为深入的研究,并以具体实例说明了Building Exodus软件在人群疏散模拟分析中的具体应用,为完善该研究方向的计算机模型和促进软件的开发提供理论和方法的指导.文章得出的结论是：“非适应”人群行为的研究需要从心理学和社会学的角度建立人群中个人行为与社会行为的理论框架.“非适应”人群行为的研究方法必须与紧急情况相结合,而紧急情况是一个由多个人员组成的复杂系统,大量人群环境的模拟需要涉及到人与人之间,人与环境之间的相互作用.     

MULTIPURPOSE OPERATION STUDIES OF A CANAL-LAKE-RIVER SYSTEM-OSWEGO RIVER SYSTEM,NEW YORK1

Use of systems analysis techniques for setting up flow regulation rules for the Oswego River System, a canal-river system with eight lakes, was examined. Two sets of lake regulation rules were proposed: the rule curve for each lake, and the lake-use priority curves for all the lakes. The former specifies balanced allocation of the storage in lakes to conservation pools and flood control pools and, the latter determines lakes releases depending upon the type of operation, the time of the year, and systems objectives. A generalized mathematical representation of the complex, multipurpose, multilake river systems operation is described. With appropriate measures of effectiveness and details of analysis, the problem was then solved with simulation and optimization. Use of the results in assisting basin plan formulation is also discussed.     

Dynamic Modeling of Ground‐Water Quality Using Bayesian Techniques1

Abstract: Water industry experts have been arguing that the traditional techniques are not an accurate means of measuring water contamination. This is mainly because these techniques emphasize neither the stochastic nature of the water contamination process nor the precision and the accuracy of the tested methods used by environmental laboratories. In this work, we describe the development and application of prototype Dynamic Bayesian Networks (DBNs) that model ground‐water quality to determine the impact of chemical contaminants on ground‐water quality in the Salalah area, which is allocated to the south of Oman. We also present a new technique for data pre‐processing because it is needed for the treatment of ground‐water datasets that are used as the data source to learn the probabilities for dynamic decision models. Among more than 20 wells in area, only four wells were selected to be analyzed and the results show that we achieved an acceptable level of efficiency.     

Invasion of Gleditsia triacanthos in Lithraea ternifolia Montane Forests of Central Argentina

Gleditsia triacanthos and the native dominant Lithraea ternifolia in montane forests of central Argentina, considering life history and demographic traits of both the alien and the native species and different site conditions for population growth (good and bad sites). Matrix models are applied to project the consequences of differences in vital rates for population growth. Analyzing these models helps identify which life cycle transitions contributed most to population growth. Obtained population growth rates are considered to assess predicted rates of spread using the reaction-diffusion (R-D) model. G. triacanthos presents many of the life history traits that confer plants high potential for invasiveness: fast growth, clonal and sexual reproduction, short juvenile period, high seed production, and high seed germinability. These traits would ensure G. triacanthos invasive success and the displacement of the slow-growing, relatively less fecund native L. ternifolia. However, since disturbance and environmental heterogeneity complicate the invasibility pattern of G. triacanthos in these montane forests, the outcome of the invasion process is not straightforward as could be if only life history traits were considered. Great variation in demographic parameters was observed between populations of each species at good and bad sites. Though both good and bad sites signified increasing or at least stable populations for G. triacanthos, for L. ternifolia bad sites represented local extinction. Analyzing the results of matrices models helps design the optimal management for the conservation of L. ternifolia populations while preventing the invasion by G. triacanthos. The predicted asymptotic rate of spread for G. triacanthos at the good site was fourfold greater than the predicted one for L. ternifolia, although the difference was much smaller considering the bad site. The usefulness of the R-D model to study this invasion system is discussed.     

Evaluation of a conceptual model for the subsurface transport of plutonium involving surface mediated reduction of PuV to PuIV

A conceptual model is proposed to explain the transport behavior of plutonium in laboratory columns packed with a sandy coastal soil from the U.S. Department of Energy (DOE)'s Savannah River Site. The column transport experiments involved the introduction of a finite step input of plutonium, predominately in the +5 oxidation state, into the columns followed by elution with a low-carbonate solution of 0.02 M NaClO4 at pH 3, 5, and 8. Total plutonium concentrations were measured in the effluent as a function of time. These elution profiles suggest at least two distinct physical/chemical forms of plutonium, each with a different mobility. To explain the observed behavior, the following conceptual model was evaluated: [1] equilibrium partitioning of plutonium (V) and plutonium (IV) between the aqueous and sorbed phases as defined by pH-dependent, oxidation-state specific distribution coefficients and [2] kinetic reduction of plutonium (V) to plutonium (IV) in the sorbed phase. The conceptual model was applied to the column experiments through a one-dimensional advective/dispersive mathematical model, and predictions of the mathematical model were compared with the experimental data. Overall, the model was successful in predicting some of the major features observed in the experiments. It also yielded quantitative estimates of the rate constant for surface mediated reduction of plutonium (V) to plutonium (IV) that were of the same order (10(-4) to 10(-5) s(-1)) as those calculated from batch data both for this soil and for goethite.     

Optimization of the Resources Management in Fighting Wildfires

Wildfires lead to important economic, social, and environmental losses, especially in areas of Mediterranean climate where they are of a high intensity and frequency. Over the past 30 years there has been a dramatic surge in the development and use of fire spread models. However, given the chaotic nature of environmental systems, it is very difficult to develop real-time fire-extinguishing models. This article proposes a method of optimizing the performance of wildfire fighting resources such that losses are kept to a minimum. The optimization procedure includes discrete simulation algorithms and Bayesian optimization methods for discrete and continuous problems (simulated annealing and Bayesian global optimization). Fast calculus algorithms are applied to provide optimization outcomes in short periods of time such that the predictions of the model and the real behavior of the fire, combat resources, and meteorological conditions are similar. In addition, adaptive algorithms take into account the chaotic behavior of wildfire so that the system can be updated with data corresponding to the real situation to obtain a new optimum solution. The application of this method to the Northwest Forest of Madrid (Spain) is also described. This application allowed us to check that it is a helpful tool in the decision-making process.     

Urban waste recycling behavior: antecedents of participation in a selective collection program

ABSTRACT/ The aim of this study is to analyze the antecedents of urban waste recycling behavior. To achieve this goal, a concrete urban waste management program was chosen. The study focuses on the Selective Collection Program (SCP) in Zaragoza, a medium-sized city in northeastern Spain. The research starts with a conceptual model in which the variables that potentially affect recycling behavior can be classified into two groups: incentives and barriers. Moreover, the sociodemographic characteristics of the individuals are included in our study. Given that the proposed model requires specification of latent variables or constructs, the analysis is based on the Structural Equation Models (SEM) methodology. The results revealed that environmental awareness, knowledge of the environmental impact of urban waste, and the positive perception of management by local government exercise a positive effect on individual recycling behavior, while perceived personal difficulties (space and time availability) and distance to and from the container have a negative effect. As regards sociodemographic variables, this study found that annual family income sustains a negative relationship with recycling behavior, while age maintains a positive one. The results obtained clearly show the important role that the public authorities play, especially municipal governments, in achieving the waste recycling objectives established in accordance with international legislation.     

An assessment methodology for successional systems. II. Statistical tests and specific examples

This paper presents a dynamic framework for environmental assessment when the system under study is undergoing successional change. Successional differences between sites for which one wishes to detect a difference because of a treatment are essentially confounding factors. We show how successional changes over the study period or resulting from differences in study site plot ages can be factored out by developing a null model of expected behavior over time. The null model for change in state with time is characterized in terms of a stochastic envelope around a nominal trajectory. Specific tests for the detection of trends associated with succession are described and illustrated on example data. It is concluded that the methods developed work particularly well for laboratory microcosm data.     

THRESHOLD TIME SERIES MODELING OF TWO ICELANDIC RIVERFLOW SYSTEMS1

ABSTRACT: This paper reports our experience in building time series models which connect the flows in two Icelandic rivers with the meteorological variables of precipitation and temperature. Two rivers with different hydrological characteristics were studied. In areas where precipitation may be either in the form of rain or snow linear models are inadequate to describe the relationship between the river and the meteorological variables. The methodology of threshold models recently developed seems to be well suited for taking into account the sharp difference in the relationship according to whether it is freezing or not. The possibility of identifying an alternative threshold variable is also explored.     

A PHOSPHORUS MANAGEMENT LP MODEL CASE STUDY1

ABSTRACT A linear programming model to assess the cost-effectiveness of appropriate point and nonpoint phosphorus control measures was constructed for Carnegie Lake, an eutrophic lake located in Mercer County, New Jersey. The resultant model was tested for present and future conditions. Feasible solutions were obtained only after significant relaxation of receiving water quality standards. The high levels of point source treatment required to meet the in-stream water quality standards and the mesotrophic loading conditions suggest that a source control solution may not be feasible.