注水过滤器滤芯主体质量可靠性试验与改进

结合采油现场实际，通过综合分析滤芯失效的表现形式，将滤芯材质、主体管壁厚度、过水孔密度作为影响滤芯主体现场使用寿命的三个可靠性主导影响因素，合理确定位极，科学设计试验方案；通过对过滤器滤芯主体的筛选试验，确定了经济合理、满足现场需要的滤芯主体。采用新型滤芯主体实现了在保持注水流量的同时，提高了滤芯的承压强度，可靠性增强。新型滤芯主体在正常工作压力环境中，使用时间平均为30天，是改进前的3倍。采用可拆洗式滤网结构,更换滤网方便快捷,减少了工人的劳动强度，可有效节约滤芯的成本投入,推广应用前景广阔。     

Has the ‘franc fort’ exchange rate policy affected the inflationary dynamics? Theory and new evidence

Abstract

This paper examines the impact of the ‘franc fort’ policy implemented in France from 1983 on the inflationary dynamics by means of a square root Kalman filter approach. An interesting aspect of the analysis is the evidence that the ‘franc fort’ exchange rate policy had a significant impact on the inflationary dynamics in France through its credibility effects. These results confirm the imported credibility hypothesis according to which the French authorities accelerated the disinflation process by importing the German monetary policy credibility through the ‘hard peg’ of the franc–DM exchange rate. These findings show that inflation dynamics in France began to converge significantly to that in Germany after the implementation of the ‘franc fort’ policy, making more credible the plan for the final transition to the euro. Moreover, this analysis may also reveal much about the nature of potential success of the current initiative of the new member countries now in the process of joining the EU and looking eventually to adopt the euro.     

Varying the VaR for unconditional and conditional environments

Accurate forecasting of risk is the key to successful risk management techniques. Using the largest stock index futures from 12 European bourses, this paper presents VaR measures based on their unconditional and conditional distributions for single and multi-period settings. These measures underpinned by extreme value theory are statistically robust explicitly allowing for fat-tailed densities. Conditional tail estimates accounting for volatility clustering are obtained by adjusting the unconditional extreme value procedure with GARCH filtered returns. The conditional modelling results in iid returns allowing for the use of a simple and efficient multi-period extreme value scaling law. The paper examines the properties of these distinct conditional and unconditional trading models. The paper finds that the biases inherent in unconditional single and multi-period estimates assuming normality extend to the conditional setting.     

Brand effect on extended warranty valuation: Subjective value versus popularity

In five experiments, we explore the effect of brands on warranty valuation and the conditions under which two mechanisms – liking based and availability based – determine the effect. We explore the moderating role of focused deliberation, which accentuates the brand effect under availability mechanism but reduces the effect under subjective value-based mechanism. In Experiment 1, we consider brands that vary in terms of both subjective value and popularity. When a brand is better in both subjective value and popularity, it commands higher warranty WTP. Focused deliberation moderates this effect of brand on warranty valuation. In Experiment 2, we consider brands that vary only in terms of subjective values (but not popularity). While the warranty valuation of the two brands does not differ under no deliberation, deliberation decreases WTP for brands with higher subjective value. In Experiment 3, we consider brands that differ only in terms of popularity (and not subjective value). In this context, deliberation increases warranty WTP for the more popular brand. Experiments 2A and 3A use warranty choice as the dependent variable and conceptually replicate the effects obtained in experiments 2 and 3, respectively.     

浅层地下水监测井快速成井工艺试验

地下水监测井是进行地下水各项参数监测的重要途径。随着监测技术的发展,对于成井井管直径的要求越来越小,但是受常规成井工艺的制约。为保障填砾止水工序顺利实施,井管与井壁之间间隙需求较大,使得监测井井径依然较大,而且常规成井工艺工序烦琐、效率低,对地下水填砾止水分层的精细化、准确度较差。依据地下水监测井的目的和特点,通过试验与分析对常规成井工艺进行优化,采用预制滤水管体和止水管体替代填入砾料和止水材料的流程,简化成井工艺,同时满足小口径成井需求,可有效提高钻进效率,降低施工成本,精细准确地进行滤水段和止水段分层,并分析了优化后成井工艺的可靠性,为优质高效地建设浅层地下水监测井提供技术支撑。     

The consequence of possessions: Self-identity,extended self,psychological ownership and probabilities of purchase for pet’s fashion clothing

This research attempts to exemplify whether pets ascribed as possessions can be regarded, as part of our selves, i.e., a metaphoric relationship with pets, by examining the dynamic relationship between beliefs, extended self, self-identity concerning possessions, and psychological ownership.This study extends the literature by developing a conceptual model asserting that probabilities of purchase for pets, in particular, are contingent on possessions and the extended self. A sample of 326 pet owners was selected, and by using SEM, the direct and indirect relationships were explored. Self-identity and beliefs were significantly associated with psychological control and the extended self, however, beliefs were negatively related to the probabilities of purchase. The extended self and the psychological ownership demonstrated mediating relationships. The study contributes to an understanding of the theoretical relationship between the role of possessions and provides scholars and retail practitioners with an understanding of probabilities of purchase for pet fashions.     

Nowcasting China’s GDP Using a Bayesian Approach

Real time nowcasting is an assessment of current-quarter GDP from timely released economic and financial series before the GDP figure is disseminated. Providing a reliable current quarter nowcast in real time based on the most recently released economic and financial monthly data is crucial for central banks to make policy decisions and longer-term forecasting exercises. In this study, we use dynamic factor models to bridge monthly information with quarterly GDP and achieve reduction in the dimensionality of the monthly data. We develop a Bayesian approach to provide a way to deal with the unbalanced features of the dataset and to estimate latent common factors. We demonstrate the validity of our approach through simulation studies, and explore the applicability of our approach through an empirical study in nowcasting the China’s GDP using 117 monthly data series of several categories in the Chinese market. The simulation studies and empirical study indicate that our Bayesian approach may be a viable option for nowcasting the China’s GDP.     

Labor productivity forecasts based on a Beveridge–Nelson filter: Is there statistical evidence for a slowdown?

In this paper, I assess the evidence for a structural break in labor productivity growth in the years before the Great Recession with the use of out-of-sample forecasting exercises for the years 2010 to 2019 and the recently developed Beveridge–Nelson filter. Models based on a Beveridge–Nelson filter with no structural breaks outperform those allowing for a structural break, and there is statistically significant evidence that they outperform the random walk, though all models were too optimistic about labor productivity growth. Recently developed statistical tests do point to the presence of a structural break before the Great Recession, but uncertainty about the data-generating process for labor productivity growth or the timing and magnitude of the break may be too great to be helpful in forecast preparation.     

Analyzing tactical control strategies for aircraft arrivals at an airport using a queuing model

This paper proposes to analyze control strategies for arrival air traffic at an airport using a classical queuing model. The parameters of our model are estimated by means of a data-driven analysis of two years of radar tracks and flight plans for arrival flights at Tokyo International Airport from 2016 to 2017. Our results show that increasing the capacity with one or two more aircraft in the airspace up to 60 NM around the airport significantly mitigates arrival delays, even when assuming future, increased arrival traffic volumes. The outcomes of this study provide insights into the effectiveness of arrival control strategies and are seen as a means to recommend scenarios to be further analyzed with human-in-the-loop simulations.     

Strategic take-back programs when consumers have heterogeneous environmental preferences

We look at the strategic introduction of take-back programs (TBPs) which offer consumers a discount on their next purchase (reward) when they drop off previous purchases. In a Hotelling duopoly, consumers are heterogeneous not only in terms of their location on the Hotelling line but also in terms of their recycling preferences. Firms introduce TBPs to obtain a market share advantage (reward effect) and/or to recover the intrinsic value of the recycled units (recycling effect); their choice of the optimal reward balances these two effects: for instance, a firm might be willing to introduce a TBP, even if this means losing money on each recycled unit, in order to prevent the competitor from gaining a too large market share advantage. Comparing the level of TBP uptake at the market equilibrium to the one that maximizes social welfare, we show that a lower or higher TBP uptake can be socially desirable, depending, among other, on the weight that is given to the environmental benefits of TBPs. Several extended producer responsibility policies are discussed in terms of their potential to encourage TBP uptake and their overall impact on social welfare.