Housing hardship and energy insecurity among native-born and immigrant low-income families with children in the United States

The costs for rent and utilities account for the largest share of living expenses, yet these two critical dimensions of material hardship have seldom been examined concurrently in population-based studies. This paper employs multivariate statistical analysis using American Community Survey data to demonstrate the relative risk ratio of low-income renter-occupied households with children experiencing ‘rent burden', ‘energy insecurity', or a ‘double burden’ as opposed to no burden. Findings suggest that low-income households are more likely to experience these economic hardships in general but that specific groups are disproportionately burdened in different ways. For instance, whereas immigrants are more likely to experience rental burden, they are less likely to experience energy insecurity and are also spared from the double burden. In contrast, native-born African Americans are more likely than all other groups to experience the double burden. These results may be driven by the housing stock available to certain groups due to racial residential segregation, decisions regarding the quality of housing low-income householders are able to afford, as well as home-country values, such as modest living and energy conservation practices, among immigrant families. This paper also points to important policy gaps in safety net benefits related to housing and energy targeting low-income households.     

我国企业品牌定位的五层次研究

近年来中国企业的品牌建设取得了可喜的成绩,出现了许多优秀品牌,这些品牌凭借独特、合适的定位取得了成功。但企业在品牌定位方面存在许多误区,如把品牌定位看作产品定位、品牌定位模糊,缺乏差异性和明确的核心价值、品牌盲目延伸导致定位混淆等问题。因此,产品品牌定位必须树立正确的定位理念,应用正确的品牌定位方法。正确的品牌定位方法可分为产品特征定位、物质利益定位、情感利益定位、个性定位以及价值观定位共五个层次。     

An evaluation of the tandem configuration automated guided vehicle system

The performance of a tandem automated guided vehicle (AGV) system is compared with that of conventional AGV track systems. In the tandem system the track is divided into non-overlapping, single-vehicle closed loops. Using simulation it is shown that, because of trips requiring delivery across loops, the tandem system has a higher expected travel time per load and thus a greater average time in system. When the loads are delivered within the original loop only, the tandem system has a lower average time in system than in conventional systems, although the difference is modest. Track layout appears to influence the average time in system much more than docs the dispatching rule invoked. The success of the tandem system is highly dependent on approximately even AGV utilization, which may be difficult to obtain in practice.     

指导学生参加英语口语比赛的实践和启示

介绍了广东省高职院校英语口语比赛的内容和方式,结合自身教学和指导比赛的实践,由此对现用教材、现有课程活动设置、学生的英语习惯思维以及师资引发了思考,在对先用教材和比赛用书进行比对的基础上,提出了相关对策建议。     

大学教学价值取向:历史与现实

从影响当前大学教学方方面面的价值取向看,大学教学要坚守古代的"理智培育"价值取向,这是大学教学永葆魅力的根源所在.同时,大学教学要张扬现代的"技术获取"价值取向,这是作为生活世界现象的大学教学的重要使命之一.第三,大学教学要倡导后现代的"欲望释放"价值取向,这是大学教学充满生机与活力的保证.因此,大学教学价值取向并非还原为欲、技、道中的某一维,而是这三者的有机统一.     

信念愿望意图逻辑探析

在理性主体寻求达成其目的的过程中,信念、愿望和意图起着重要的作用。由 Rao 和Georgeff 提出的信念愿望意图逻辑是建立在分支时间可能世界模型的基础之上的。说明了该逻辑框架对意图的重要成分（比如：信念、愿望、意图和承诺）是如何进行形式化的。另外,不同类型的理性主体可以通过添加特定的条件来进行建模。     

生命周期评价与环境伦理

评价材料与环境协调性的生命周期评价方法有环境伦理的哲学基础,是环境伦理的核心观点的科学体现。然而,从科学角度来看的生命周期评价方法的局限性则未必真是它的局限性,在对其作出环境伦理学的说明之后,有些局限性不过是哲学与科学的内在矛盾的体现,是科学自身的局限性的折射而已。     

MRP理论与方法的研究

对物料需求计划的理论和方法进行研究,并对物料需求计划系统进行逻辑计划。     

考虑时效与公平性的震后应急物资动态配送优化研究

大规模地震后应急物资的高效保障是应急救援有效开展的必要前提。震后应急物资运输与配送包括从区域储备仓库和外围物资集散地运输到区域应急配送中心、由区域应急配送中心配送到各个受灾点两个阶段。应急物资保障具有持续时间长、需求紧迫性强和物资相对短缺等特点。本文以应急物资保障时效性与分配公平性为目标,建立了考虑多种运输方式、多时段动态的应急物资配送中心选址与运输配送路径优化的多目标规划模型,并基于此模型设计了一种带精英策略的非支配排序的遗传算法,以九寨沟地区地震灾难情景对模型进行实证研究,验证了模型和算法的有效性,以期为震后应急物资保障提供理论指导与决策支持。     

连续物料订单分拣完全-并行限定(k=1)轮询控制机理

中国是粮食生产大国和人口大国,粮食问题对于我国经济社会的发展具有举足轻重的影响。现有粮食供应链"层层批发"的流通体制不能满足消费者个性化需求。所以,本文基于客户的个性化需求,应用轮询系统理论来研究面粉、大米等粮食连续物料的订单分拣自动化控制机理。本文根据实际业务需求设定普通订单、优先订单,对优先订单的分拣实行完全服务控制策略,对普通订单分拣实行限定（k=1）服务控制策略,建立完全-并行限定（k=1）的二级优先级订单分拣轮询控制系统模型,确保优先业务订单顾客得到更优质服务,同时保证订单分拣系统的公平性。采用嵌入式Markov链、多维概率母函数和拉式变换求解理论模型,并通过数值计算分析,精确求解其一阶系统特性、二阶系统特性等关键性能参数,从而深入研究连续物料订单分拣的控制机理。