Saving babies? Revisiting the effect of very low birth weight classification

We reconsider the effect of very low birth weight classification on infant mortality. We demonstrate that the estimates are highly sensitive to the exclusion of observations in the immediate vicinity of the 1,500-g threshold, weakening the confidence in the results originally reported in Almond, Doyle, Kowalski, and Williams (2010).     

The recession's effect on hospital registered nurse employment growth

Recessions are not uncommon in the United States, but the most recent recession is arguably the most severe economic downturn since the Great Depression of the 1930s. Although recessions result in increases in national unemployment in most sectors of the economy, they have resulted in increases in registered nurse (RN) employment as many non-working married RNs re-enter the workforce when their spouses lose their jobs. Over the past decade, hospital RN employment increased by more than 400,000 with virtually all of this growth associated with the two recessions that occurred during this period. The most recent recession led to an increase in hospital RN employment that was not only unprecedented in size, estimated at nearly 250,000, but was marked by the employment of large numbers of RNs over 50 years of age. While national unemployment rates remain high, hospitals should prepare for an eventual jobs recovery when many RNs are likely to leave the workforce.     

新环境下投资思维的转变

随着QE2的推出,欧债危机的进一步扩散,中东地区的不稳定事件,以及我国面临经济转型,国际国内形势更加错综复杂。2010年上证指数的萎靡而中小创业板的活跃,使多数投资者转变为概念炒作。追涨杀跌。2011年,权重股的价值回归而中小创业板的一路下跌,使多数投资者的收益大幅缩水。在这新环境下,通过分析各因素对我国A股市场的影响,得出结论：投资者应适时转变投资思维,采取价值投资并结合技术分析进一步扩大收益。     

The impact of the amount of available information on decision delay: The role of common features

In two studies, we show that features shared by products (common features) do not cancel out during the decision-making process but in fact are consequential as they decrease desire for delay in decision making. In study 1, we show that as the amount of available information about product features increases, decision delay decreases in spite of the additional information being identical across the products. Further, we also find that this effect is partially mediated by information adequacy. In study 2, we show that despite the overall difficulty of making decisions under avoidance?Cavoidance versus approach?Capproach conflict, an increase in common features decreases decision delay under both conflict conditions.     

Empirical and Heuristic-Based Evaluation of Collaborative Modeling Systems: An Evaluation Framework

Within the field of groupware systems, collaborative modeling systems play an important role. They are useful and promising tools for many fields of application. In this paper we begin with the evaluation of the usefulness of one of these tools, SPACE-DESIGN, by applying it to a specific domain and by comparing it to a single-user tool which is shared by means of a shared window system. We have performed a study in two phases in order to evaluate usability aspects and the awareness support of both software tools. The first phase is an empirical study with users who have worked with both software tools, whilst the second is a heuristic study with some heuristic models that are well known in the context of the research work. Taking into account this study, we propose a complete evaluation framework, to be used as a theoretical lab which could be used to evaluate interactive and usability aspects of any collaborative modeling tool. This is based on a comparison strategy and proposes a specific sequence of phases: selection of collaborative modeling tools, empirical evaluation, heuristic evaluation, analysis of results, and obtaining of conclusions.     

The joint replenishment and freight consolidation of a warehouse in a supply chain

We have developed joint replenishment and consolidated freight delivery policies for a third party warehouse that handles multiple items, which have deterministic demand rates in a supply chain. Two policies are proposed and mathematical models are developed to obtain the optimal parameters for the proposed policies. Four efficient algorithms are presented to solve the mathematical models for the two policies. The performances of the two policies with the parameters obtained from the proposed algorithms are then compared with the common cycle approach for 1600 randomly generated problems. The results show the robust performance of the proposed algorithm for both policies.     

Simultaneous control of production, repair/replacement and preventive maintenance of deteriorating manufacturing systems

This paper presents a method to find the optimal production, repair/replacement and preventive maintenance policies for a degraded manufacturing system. The system is subject to random machine failures and repairs. The status of the system is deemed to degrade with repair activities. When a failure occurs, the machine is either repaired or replaced, and a replacement action renews the machine, while a repair action brings it to a degraded operational state, with the next repair time increasing as the number of repairs increases as well. A preventive maintenance action is considered in order to improve the reliability of the machine, thereby reducing the amount of disruptions caused by machine failures. The decision variables are the production rate, the preventive maintenance rate and the repair/replacement switching policy upon machine failure. The objective of the study is to find the decision variables that minimize the overall cost, including repair, replacement, preventive maintenance, inventory holding and backlog costs over an infinite planning horizon. The proposed model is based on a semi-Markov decision process, and the stochastic dynamic programming method is used to obtain the optimality conditions. A numerical example is given to illustrate the proposed model, and a sensitivity analysis is considered in order to confirm the structure of the control policy and to illustrate the usefulness of the proposed approach.     

Methods and tools contributing to FTA: A knowledge-based perspective

Future oriented technology analysis (FTA) applied to innovation policy and practice often goes well beyond the narrow domain of technology forecasting. It is oriented to supporting the functioning and development of innovation systems, and involves mutual learning processes, involving stakeholders and experts of many kinds. Such FTA calls for crossing the boundaries of disciplines, research traditions, and professional activities FTA then necessarily involves knowledge management (whether this be formal or implicit); and this knowledge management has to confront the challenges created by FTA's call for engagement across different - and across potentially competing - corporate, sectoral, and public interests. This paper explores the consequences of this view of FTA and how the roles of various FTA methods and tools are seen in terms of knowledge management. It goes on to discuss the implications that follow for FTA design, and the methodological challenges, and requirements for development of tools, techniques and principles, for FTA. The challenges of participatory knowledge management are seen to be particularly important ones to tackle.     

Decision aid reliance: Modeling the effects of decision aid reliability and pressures to perform on reliance behavior

We investigate the effects of decision aid reliability and pressure to perform on decision aid reliance. A total of 403 students took part in a four (pressures to perform: one through four) by five (decision aid reliability: 50%, 60%, 70%, 80% and 90%) between-participants experiment. We test two competing models of decision aid reliance behavior: pressure-induced rationality and pressure arousal theory. Additionally, we introduce a general model of reliance on a decision aid. We find that pressure arousal theory predominantly explains decision aid reliance behavior at all but the highest level of decision aid reliability tested in this study (90%). Our results indicate that there are reliance peaks across the reliability levels as more pressure to perform is applied, and that continually increasing pressures can eventually lead to decreased, rather than increased, reliance.     

The land cost of agrarian sustainability. An assessment

Improving the sustainability of farms often incurs additional costs for farmers. These costs come from allocating land to the maintenance of the ecological processes (energy and material flows, natural population regulation) required for the agroecosystem to function. Since these costs are not recovered on the markets, farmers see a fall in profits, the financial viability of their farms is compromised, and they suffer the consequences of the environmental services they are providing. All this makes it essential to implement government policies designed to compensate farmers for their efforts. The issue of how to assess sustainability has generated widespread debate within ecological economics, specifically as to whether it is possible to place a monetary value on it and if so, how this should be done. In a previous article we showed that agrarian sustainability involves a land cost, therefore this cost can be translated into monetary values. The purpose of this study is to develop this concept in practical terms by applying it to organic farming. We calculated the land cost of agrarian sustainability (LACAS) in order to compare organic versus conventional management in olive farming, as this crop is grown extensively in Spain and other Mediterranean countries. The results show that the agro-environmental subsidy is not enough to encourage olive growers to make the conversion from conventional to organic methods, because the land cost of sustainability is not adequately offset. They also show that improving agroecosystems can allow the land to take on more functions without increasing the land cost. In our case, encouraging the multifunctionality of the land has permitted a reduction in this cost. The LACAS could be a useful tool, not only for drawing up government policies designed to support organic farming, but also for improving the sustainability of the agrarian sector.