The opportunity costs of commuting: the value of a commuting satellite account framework with an example from Lisbon Metropolitan Area*

Commuting affects regional and urban economies. It shapes urban areas, defines their relationships with neighboring regions, intensifies economic flows and exacerbates energy consumption and greenhouse gas emissions. This paper sets out a proposal for an innovative commuting satellite account (CSA), integrated in a multi-regional input–output model. This framework combines commuting activities with regional distribution of income, distinct household consumption structures, real estate renting activities and the energy consumption and environmental flows incorporated in the different industries. To assess the opportunity costs of commuting, the CSA framework is applied to the Lisbon Metropolitan Area. The socio-economic-environmental impacts of a scenario in which commuters become non-commuters by moving their residence to the municipality in which they work are estimated. The analysis indicates that: commuting, in general, induces significant economic and environmental opportunity costs. Finally, the adoption of policy-oriented recommendations contributing to limit sprawling in metropolitan regions is discussed.     

The estimation of a state space model by estimating functions with an application

Conventionally the parameters of a linear state space model are estimated by maximizing a Gaussian likelihood function, even when the input errors are not Gaussian. In this paper we propose estimation by estimating functions fulfilling Godambe's optimality criterion. We discuss the issue of an unknown starting state vector, and we also develop recursive relations for the third- and fourth-order moments of the state predictors required for the calculations. We conclude with a simulation study demonstrating the proposed procedure on the estimation of the stochastic volatility model. The results suggest that the new estimators outperform the Gaussian likelihood.     

The structure of ARMA solutions to a general linear model with rational expectations

A parameterc characterization is provided for the complete class of stationary and non-stationary ARMA solutions, generated by the fundamental exogenous innovation, to a general linear univariate model with rational expectations. The dimension of the solution space of ARMA parameters is given and shown to be generically equal to the maximum period forward over which expectations are formed. The validity of deleting common factors in non-stationary ARMA processes is discussed, and specific solution choices often recommended are shown to be ‘common factor’ solutions.     

借鸡生蛋建造希尔顿大饭店

唐拉德·希尔顿出生于1887年美中新墨西哥圣安东尼奥的一个小贩家里,他后来成为世界上赫赫有名的旅店大王。在他成功之路上有许多令人难忘的趣事,其中借鸡生蛋建造希尔顿大饭店最富有戏剧性。     

The applicability of the Tampa Scale of Kinesiophobia for patients with sub-acute neck pain: a qualitative study

The purpose of this study was to qualitatively evaluate patients understanding and interpretation of the wording used in test items of the Tampa Scale of Kinesiophobia (TSK). The TSK was developed to measure fear of movement in patients suffering from low back pain. The TSK is being increasingly used for other pain conditions. Patients with sub-acute neck pain experience problems while completing this questionnaire. The aim of this study was to elicit these problems. The study was conducted within the framework of a randomised controlled trial. The Three-Step Test Interview (TSTI) was used to collect data on the thoughts or considerations of respondents while completing the TSK. In the analysis, each transcribed interview was divided into three segments. The thoughts and considerations were then analysed and categorised per item. During the TSTI two problems were identified. One concerned the meaning of specific words used, like “dangerous” and “injury”. The other problem was that several implicit assumptions within some items make it difficult for respondents to answer these items. It was concluded that in the development and validation of questionnaires like the TSK, not only quantitative psychometric properties are important, but also qualitative research has an important contribution to enhance applicability.     

以TK404井为例浅析注气提高采收率在塔河4区的应用

塔河油田4区奥陶系油藏单井单元经过历年多轮次注水替油,油水界面不断抬升,多数已进入失效阶段,剩余油在构造高部位聚集,形成所谓的"阁楼油"。在注气驱替"阁楼油"的理论基础上,为进一步提高塔河4区采收率,选择具有独立缝洞结构,前期注水替油效果较好且目前已失效的单井单元,进行注氮气开发。目前注气采油在塔河4区仍处于实验阶段,仅选取TK404、T415CH、T416及TK489井小范围试注,以TK404井为例,通过对注气量、闷井时间、注气采油方式、注气速度进行优化,总结出合理的注气方法;通过对注气后生产动态变化情况的分析,得出注气提高采收率在塔河4区切实可行的结论。     

The predictive power of fund ratings with a novel approach using uncertainty measures to analyzing risk

Using two approaches to panel data, Granger causality analysis with semi-asymptotic tests, and a structural approach based on entropies measured on sequences of multiperiod ratings and returns, we specify the relationship between a fund’s performance and both Morningstar and Europerformance ratings. We conclude on the Europerformance agency’s forecasting ability for the Luxembourg funds, and the Morningstar agency for the French funds. Indeed, we find two groups of funds depending on their domiciliation and appropriated rating. The results of this paper have implications for the management of fund portfolios, and the structural approach, more robust to our data, must be a first process for forecast models on the basis of similar funds, minor uncertainty or risk measure, and appropriated rating.     

新形势下科技期刊编辑应具备的素质

在新形势下,科技期刊工作对编辑人员提出了更高的要求.文章从政治素质、科学素质、业务素质及创新素质等方面对新形势下科技期刊编辑应具备的素质进行了探讨.     

新形势下科技期刊编辑应具备的素质

在新形势下,科技期刊工作对编辑人员提出了更高的要求。文章从政治素质、科学素质、业务素质及创新素质等方面对新形势下科技期刊编辑应具备的素质进行了探讨。