The Pay As You Save program in rural Arkansas: An opportunity for rural distribution cooperative profits

This case study highlights the success of the Ouachita Electric Cooperative’s Pay As You Save program in Camden, Ark., in bringing both electricity bill savings to customers and benefits to implementing utilities, especially in rural areas. It is not specifically a low-income energy assistance program, but does benefit customers with high energy burdens. Through its on-bill tariff design, PAYS overcomes many barriers, such as the split incentive challenge and the need for upfront outlays.     

跨地区电力交易输电服务价格机制

合理的输电服务价格机制是促进和引导跨地区电力交易的关键问题。文中针对跨地区电力交易,对比分析了多级电网叠加定价与全网统一定价2种定价模式的适应性,结合中国跨地区输电网网架和资产结构特点,以及跨地区电力交易特点,提出了跨地区电力交易全网统一输电定价的基本思想和方法,并建立了综合输电费用分摊及输电收益分配的输电定价机制。首先,考虑各地区电网的运行基态,计算跨地区输电网中每个节点的边际成本,并基于节点边际成本计算每笔跨地区电力交易的电网使用费;然后,考虑各级电网的线路长度和交易电量因素,将输电收益在各电网运营商之间进行再分配。IEEE 30节点算例表明,所提出的综合输电费用分摊及输电收益分配的跨地区输电价格机制新颖有效,各笔跨地区电力交易的电网使用费计算合理,能够起到有效促进和引导跨地区电力交易的作用。     

基于异构磁盘阵列的数据备份/恢复技术研究

随着网络技术的快速发展与网络资源的日益丰富。数据的存储量级急速增长,数据保护的重要性显得尤为重要,如何快速有效地对数据进行备份/恢复成为数据保护领域亟待解决的关键问题之一。通过对异构磁盘阵列的数据分配方法进行优化,使不同磁盘阵列间进行数据备份/恢复速率提升。提出划分异构磁盘I/O带宽方式提高磁盘数据读取速度的可行性方案,与传统的数据备份/恢复相比,在时间利用率和备份性能上都得到了很大的提高。     

DPU-30型机车底架裂纹和改进的分析研究

对大连机车车辆有限公司出口巴基斯坦的DPU-30型机车底架主梁出现的局部裂纹进行了大量的现场调查,同时对出现裂纹的原因和机理进行了理论分析,在此基础上对裂纹部位提出了改进方案以及在巴基斯坦铁路现场的修复措施。为了验证改进方案的有效性,对改进方案进行了有限元计算分析,并在巴基斯坦对修复后投入运用的机车底架的动应力进行了测试,所有这些研究均证明了改进方案的可靠性。     

Evaluating the effect of ration composition on income over feed cost and milk yield

Feed is generally the greatest expense for milk production. With volatility in feed and milk markets, income over feed cost (IOFC) is a more advantageous measure of profit than simply feed cost per cow. The objective of this study was to evaluate the effects of ration cost and ingredient composition on IOFC and milk yield. The Pennsylvania State Extension Dairy Team IOFC tool (http://extension.psu.edu/animals/dairy/business-management/financial-tools/income-over-feed-cost/introduction-to-iofc) was used to collect data from 95 Pennsylvania lactating dairy cow herds from 2009 to 2012 and to determine the IOFC per cow per day. The data collected included average milk yield, milk income, purchased feed cost, ration ingredients, ingredient cost per ton, and amount of each ingredient fed. Feed costs for home-raised feeds for each ration were based on market values rather than on-farm cost. Actual costs were used for purchased feed for each ration. Mean lactating herd size was 170 ± 10.5 and daily milk yield per cow was 31.7 ± 0.19 kg. The mean IOFC was $7.71 ± $1.01 cost per cow, ranging from −$0.33 in March 2009 to $16.60 in September 2011. Data were analyzed using a one-way ANOVA in SPSS (IBM Corp., Armonk, NY). Values were grouped by quartiles and analyzed with all years combined as well as by individual year. Purchased feed cost per cow per day averaged $3.16 ± $1.07 for 2009 to 2012. For 2009 to 2012 combined, milk yield and IOFC did not differ with purchased feed cost. Intermediate levels (quartiles 2 and 3) of forage cost per cow per day between $1.45 and $1.97 per cow per day resulted in the greatest average IOFC of $8.19 and the greatest average milk yield of 32.3 kg. Total feed costs in the fourth quartile ($6.27 or more per cow per day) resulted in the highest IOFC. Thus, minimizing feed cost per cow per day did not maximize IOFC. In 2010, the IOFC was highest at $8.09 for dairies that fed 1 or more commodity by-products. Results of the study indicated that intermediate levels of forage cost and higher levels of total feed cost per cow per day resulted in both higher milk yield and higher IOFC. This suggests that optimal ration formulation rather than least cost strategies may be key to increasing milk yield and IOFC, and that profit margin may be affected more by quality of the feed rather than the cost.     

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 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.