Interval-parameter Fuzzy-stochastic Semi-infinite Mixed-integer Linear Programming for Waste Management under Uncertainty

An interval-parameter fuzzy-stochastic semi-infinite mixed-integer linear programming (IFSSIP) method is developed for waste management under uncertainties. The IFSSIP method integrates the fuzzy programming, chance-constrained programming, integer programming and interval semi-infinite programming within a general optimization framework. The model is applied to a waste management system with three disposal facilities, three municipalities, and three periods. Compared with the previous methods, IFSSIP have two major advantages. One is that it can help generate solutions for the stable ranges of the decision variables and objective function value under fuzzy satisfaction degree and different levels of probability of violating constraints, which are informative and flexible for solution users to interpret/justify. The other is that IFSSIP can not only handle uncertainties through constructing fuzzy and random parameter, but also reflect dynamic features of the system conditions through interval function of time over the planning horizon. By comparing IFSSIP with interval-parameter mixed-integer linear semi-infinite programming and parametric programming, the IFSSIP method is more reasonable than others.     

辽东湾北部双台子河口的斑海豹

2003年3月至4月及2004年3月至5月。对辽东湾北部双台子河口附近的斑海豹栖息地及斑海豹资源进行了调查。斑海豹数量和行为的观察采用海上目视直接观察及照相计数方法;栖息地的环境调查为现场结合社会调查。结果发现：斑海豹的栖息地十年来位置未改变,仍在距人海口10km处的一段河岸,但其生态环境正遭到破坏。斑海豹在该栖息地的分布时间从3月初辽东湾冰融起至5月中旬;高峰期在3月底至4月中旬之间;4月中旬斑海豹开始离开,比十年前提早半个月左右;5月中旬以后。斑海豹基本上全部离开此处。另外,斑海豹的个体数：2003年为105头。而2004年则为40头。其数量年变化较大。     

Prediction Intervals for Estimates of Site Index Based on Ecosystem Type

/ British Columbia has an ecosystem classification system that classifies sites into site series. Foresters commonly measure the productivity of these sites by their site index. In British Columbia, site index is defined as the height of a stand at breast height age 50 and is usually estimated from height-age models. Biogeoclimatic site series/site index relationships are an increasingly popular method of estimating site index in British Columbia for stands where site index cannot be reliably estimated with height-age models. The precision of the predicted site index from these relationships can be evaluated with prediction intervals. This is done for the predicted site index of a single site, a group of sites, or the areally weighted site index of a group of sites. The methodology is also useful in determining the number of sites required to meet a specified precision. These prediction intervals will assist foresters in making sound forest management decisions.KEY WORDS: Biogeoclimatic Ecosystem Classification; Precision; Prediction interval; Site index; Site series     

Satellite-Derived Mean Fire Return Intervals As Indicators Of Change In Siberia (1995–2002)

Under current climate change scenarios, temperatures in Siberia are expected to increase, and consequently, fire is also expected to increase. Potential climate-induced change is difficult to assess in Siberia because ground-based fire data are not complete. This investigation introduces a method by which potential climate-induced change can be remotely evaluated. Mean fire return intervals are established for 58 ecosystems across Siberia using eight years of satellite-based area burned data (1995 to 2002). Mean fire return intervals should decrease under current climate change scenarios, however the results do not currently demonstrate consistent evidence of fire-induced change. The overall boreal forest mean fire return interval is lower than the published mean, inferring increased fire. Most notably, using satellite data to calculate mean fire return intervals in individual ecosystems for the entire population of fire is shown to be a viable method by which potential climate-induced land cover change can be evaluated.     

时数分离残差模型及在尾矿坝渗流预测中的应用

对于非等时序列的时数分离可以建立模型，但这种模型误差分析较困难。本文在残差GM(1，1)模型的基础上，建立了时数分离残差模型，对误差进行修正。应用这种模型分析了德兴铜矿1#尾矿坝的渗流趋势，结果表明，模型能够大大提高预测精度，满足工程预测的需要。     

大气环境质量综合评价的多目标决策-理想区间法

对多目标决策 理想点法进行了分析 ,由于环境质量评价标准是区间概念而非点的概念 ,因而传统的多目标决策 理想点法把评价标准处理成理想点存在一定缺陷。为了克服这种缺陷 ,提出了一种多目标决策 理想区间法(MODIIM)。介绍了MODIIM的原理 ,给出了它的构成方法 ,并把它应用到大气环境质量综合评价中。与多目标决策 理想点法相比 ,MODIIM具有更大的适用性。MODIIM可广泛应用于各种环境质量综合评价问题中     

Adaptive two-stage one-per-stratum sampling

We briefly describe adaptive cluster sampling designs in which the initial sample is taken according to a Markov chain one-per-stratum design (Breidt, 1995) and one or more secondary samples are taken within strata if units in the initial sample satisfy a given condition C. An empirical study of the behavior of the estimation procedure is conducted for three small artificial populations for which adaptive sampling is appropriate. The specific sampling strategy used in the empirical study was a single random-start systematic sample with predefined systematic samples within strata when the initially sampled unit in that stratum satisfies C. The bias of the Horvitz-Thompson estimator for this design is usually very small when adaptive sampling is conducted in a population for which it is suited. In addition, we compare the behavior of several alternative estimators of the standard error of the Horvitz-Thompson estimator of the population total. The best estimator of the standard error is population-dependent but it is not unreasonable to use the Horvitz-Thompson estimator of the variance. Unfortunately, the distribution of the estimator is highly skewed hence the usual approach of constructing confidence intervals assuming normality cannot be used here.     

Probationary and non-probationary drivers' nighttime crashes in Western Australia, 1996-2000

INTRODUCTION: This study was designed to explore the temporal aspects of crashes for probationary and non-probationary drivers. METHODS: Data from the West Australian Road Injury Database from 1996-2000 were used to calculate age-sex-specific crash rates per 100,000 person-days and to plot proportions of fatal and hospital crashes by time for probationary and non-probationary drivers. The population attributable risk was used to estimate the potential number of lives saved by nighttime driving restriction in the probationary period. RESULTS: Probationary drivers were seven times more likely to crash than non-probationary drivers. While the highest number of crashes was in the daytime, probationary drivers had a higher proportion of fatal or hospitalization crashes at night than non-probationary drivers. CONCLUSION: Restrictions on driving at night could form part of graduated driver training. Even if some probationary drivers disobeyed the restriction, a substantial reduction in car occupant fatalities and hospitalizations could result.     

Sample size requirements for multiple regression interval estimation

Sample size planning is one of the most important issues in the design of a study. Simple and accurate sample size formulas for a desired confidence interval width have been developed for many statistical procedures, but a simple and accurate sample size formula for the squared multiple correlation has been a notable exception. Several rule‐of‐thumb sample size recommendations for a multiple regression analysis have been proposed over the years but none are satisfactory. Other approaches have focused on the construction of elaborate tables of sample size requirements, but these tables are both unwieldy and inadequate. We present a simple, accurate, and general method of approximating the sample size requirement for obtaining a squared multiple correlation confidence interval with desired precision. We also present a simple method for approximating the sample size needed to estimate unstandardized regression coefficients with desired precision. Copyright © 2010 John Wiley & Sons, Ltd.     

Quantitative Relationships between Predatory and Nonpredatory Animals in Freshwater Ecosystems

The ratios between the sizes of predators and prey have been estimated. On average, the linear sizes and body weights of aquatic predatory animals are approximately three and nine times greater, respectively, than those of nonpredatory animals. The biomass of predators in waters with different productivity levels is, on average, about 20% of the biomass of nonpredatory animals. However, the ratio between the biomasses of predatory and nonpredatory animals in the same water body may vary seasonally and annually and differ in different parts of this water body. The average numbers of predatory fish in ichthyocenoses are no more than 3% of the numbers of nonpredatory fish. The living space (individual range) of predatory fish is about 40 times larger than that of their prey. The relatively low numbers of predators in water bodies may be accounted for by the lower number of predatory species and their higher mortality at early developmental stages, compared to nonpredatory species.