Household consumption of electricity in Brazil between 1985 and 2013

This article describes the electricity consumption in Brazilian residences between 1985 and 2013 through linear regressions. The explanatory variables considered were the number of households, effective consumption of families as a proxy for family income, and electricity tariff for households. To deal with the power generation crisis of 2001 we have introduced a dummy variable in the form of a step function. With such explanatory variables, we were able to account for the reduction of household electricity consumption caused by the policies conducted in 2001 and their permanent consequences. The regression presented coefficient of determination of 0.9892, and the several statistic tests conducted assured the existence of long-term relation between the electricity consumption in residences and the explanatory variables. The obtained elasticities for the household consumption of electricity with respect to number of residences, family income and residential tariff of electricity were 1.534±0.095, 0.189±0.049, and −0.230±0.060, respectively. These results allowed understanding the evolution over time of the household consumption of electricity in Brazil. They suggest that the electric sector in Brazil should pursue an active policy to manage demand of residential electricity using tariffs as a means to control it.     

可转让农用水权分配的农民收入研究——以塔里木河流域为例

农民收益补偿是保障农用水权转让分配的重要手段。为此，在可转让农用水权分配研究的基础上，进一步构建了可转让农用水权分配的农民收入模型，并将该模型用于对2015~2030年的塔里木河流域可转让农用水权分配的农民收入进行计算。主要研究结果为：① 塔里木河流域可转让农用水权分配能使农民收入得到不断增加，而且以增加的农民直接收入为主；其中，源流增加的农民收入高于干流的。但是，农民直接收入占比降低，农民间接收入的占比得以增长。② 塔里木河流域可转让农用水权分配的农民直接收入主要由节省水费构成，农民的间接收入则主要由节水增产收入构成；但是，节省水费和节水经济补偿的农民直接收入的占比增长了，节水增产的农民间接收入占比降低了，节省种植成本的农民间接收入占比增加了，这也成为了塔里木河流域可转让农用水权分配的重要保障。     

A side-sensitive synthetic coefficient of variation chart

Control charts for monitoring the coefficient of variation (γ) are useful for processes with an inconsistent mean (μ) and a standard deviation (σ) which changes with μ, by monitoring the consistency in the ratio σ over μ. The synthetic-γ chart is one of the charts proposed to monitor γ, and its attractiveness lie in waiting until a second point to fall outside the control limits before a decision is made. However, existing synthetic-γ charts do not differentiate between the points falling outside the upper control limit (UCL) and lower control limit (LCL). Hence, this paper proposes a side-sensitive synthetic-γ chart, where successive nonconforming samples must either fall above the UCL or below the LCL. Formulae to compute the average run length (ARL), the standard deviation of the run length (SDRL) and expected average run length (EARL) are derived using the Markov chain approach, and the algorithms to obtain the optimal charting parameters are proposed. Subsequently, the optimal charting parameters, ARL, SDRL and EARL values for various numerical examples are shown. Comparisons show that the side-sensitive synthetic-γ chart consistently outperforms the existing synthetic-γ chart, especially for small shifts. The proposed chart also consistently outperforms the Shewhart-γ chart, while showing comparable or better performance than the Exponentially Weighted Moving Average (EWMA) chart for most shift sizes, except for very small shifts. Finally, this paper shows the implementation of the proposed chart on an industrial example.     

A review of root,tuber and banana crops in developing countries: past,present and future

For many of the developing world's poorest farmers and food-insecure people, roots, tubers, bananas and plantain crops (RTBs) serve as a critical source of food, nutrition and cash income. RTBs have been particularly important in areas where local agri-food systems are under stress. Under such circumstances, growers, processors and traders often see opportunities to improve food security or increase their incomes with those crops due to shifting tastes and preferences for food and non-food products. Since the early 1990s, cassava output surged in sub-Saharan Africa, while potato production expanded rapidly in Asia. RTBs are consumed by over three billion people in developing countries with a market value of US$ 339 billion. This paper analyses the major changes in production, utilisation and trade of RTBs over the last six decades, assesses estimates of their future trajectory and offers recommendations so that they might achieve their full potential.     

whittle软件境界优化设计的理念与技术方法

介绍了国外设计咨询公司处理矿石损失贫化及构建采矿模型的理念与方法,并对whittle软件优化境界的概念及技术进行了详细论证。     

Self‐employment and local economic performance: Evidence from US counties*

This study explores the relationship between self‐employment and income growth, employment growth, and change in poverty in metro and non‐metro areas in the United States using county‐level panel data. We investigate the impact of the relative size of the self‐employment sector measured by the share of non‐farm proprietorships (NFPs) in total full and part‐time employment on three key economic performance indicators. We first estimate an income growth model to analyse the effects of self‐employment on income growth. Then we investigate the independent effects of self‐employment on employment growth and changes in family poverty rates. Our results indicate that higher self‐employment rates are associated with statistically significant increases over time in income and employment growth, and reductions in poverty rates in non‐metro counties. We find similar effects on metro county income and employment, but not on poverty dynamics.     

TARGET LEVELS IN TRAFFIC SAFETY ANALYSIS

The concept of target based traffic safety investment is discussed. A procedure is developed to establish the optimum target level [reduction in accident frequency, rate, or risk] that can be achieved when the expected cost of the countermeasure(s) and the expected cost of accidents is considered. Expected level of safety without countermea-sure and effectiveness of countermeasure are both treated as random variables, and it is shown that the optimum target is dependent on the form of the probability distribution, its parameters, and the ratio of accident cost to countermeasure cost. Application of the procedure to routine safety analysis and management is demonstrated using simple numerical examples.     

一种改进的K-Modes聚类算法

传统的K-Modes算法采用0-1简单匹配方法计算对象与类中心(Modes)之间的距离,并将每个对象分配到离它最近的类中去。采用基于频率方法重新计算各类的类中心(Modes)、定义目标函数,然而,对象的归类方法和目标函数的定义没有充分考虑分类数据的特点。对此,提出一种改进的K-Modes算法,采用期望熵最小的衡量方法进行归类,并且采用期望熵作为新的目标函数。通过实验将该算法与传统的K-Modes算法进行比较,表明该算法是更有效的。     

Polluting facilities and environmental justice – a study

The environmental justice movement attempts to examine the disproportionate exposure of environmental pollution on minority and low‐income people, understand the patterns of such disproportionate exposures and develop strategies to reduce and eliminate such exposures. Unlike several environmental justice studies that include all fifty states of the United States, this study examines the locations of manufacturing facilities that pollute in states with predominantly high African‐American populations. Our analysis indicates that polluting facilities tend to choose counties with higher proportion of nonwhite populations. Per capita incomes of people living within 5‐miles of the facilities are lower than per capita incomes of people living in the host counties Contrary to the conventional wisdom, population density per square mile both within 1 mile and 5 miles of the facility are much higher than the state population densities.     

Corrosion initiation time updating by epistemic uncertainty as an alternative to schedule the first inspection time of pre-stressed concrete vehicular bridge beams

As traffic demands grow constantly and some vehicle bridges deteriorate because of corrosion issues, bridge agencies require non-expensive procedures to support decisions about cost-effective maintenance schedules. In this article, a reliability-based formulation is proposed for the prediction of the optimal first inspection time including both the corrosion deterioration and the epistemic uncertainty on the corrosion initiation time. For the identification of the bridge integrity state, where little or no follow-up has been previously developed, the prediction of a damage state implies a great deal of epistemic uncertainty. The impact of this kind of uncertainty on the corrosion initiation time prediction is appraised in order to include the conservative estimations of such a time, according to the bridge revenues/cost ratio of further and more detailed studies. The time-varying bridge reliability is calculated in terms of the bridge corrosion deterioration, which induces a moment capacity reduction of the bridge beams. Epistemic uncertainty is introduced in the corrosion initiation time, and the optimal first inspection time is obtained as a probability distribution. Consequently, a procedure to calculate the first time for inspection on girder bridges has been proposed, based on updating a known distribution after considering the effect of epistemic uncertainty, using a lognormal distributed factor as ‘evidence’, by means of the Markov chain Monte Carlo technique.