Economic Analysis of Using Renewable Wind Power System at a Signalized Intersection

The transportation industry consumes about 28% of the total energy consumed by all sectors in the United States. This paper proposes a renewable wind power system (RWPS) as an alternative power source for signalized traffic intersections. The proposed system can be mounted onto the existing transportation infrastructure to provide reliable green electricity. Large-scale implementation of such a system has the potential to dramatically change the role of the public right-of-way system from an energy consumer to an energy producer, which will reduce the transportation system operating costs and promote the development of greener roadways. This paper provides a framework to investigate the physical and economic feasibility of installing the proposed RWPS. Methodologies to conduct structural analysis, site selection, and economic analysis are developed and presented. A test intersection in Lincoln, Nebraska, is used to demonstrate the application of evaluation procedures. The proposed RWPS has two benefits: i) the power generated by the system can support the existing traffic signals and any excess power produced can be sold back to the power grid, and ii) it also provides a source of backup power in case of grid failures, increasing the reliability of traffic operations. The paper presents the methodology to ascertain the economic benefits of an RWPS for both the cases described above. The costs and benefits of providing a RWPS are stated in terms of dollar values. The decision to install a RWPS at a specific site can thus be made using a benefit-to-cost ratio. The case study shows the RWPS is economically feasible at the subject intersection in Lincoln, Nebraska. The results also show that installing an RWPS at intersections with frequent power supply failures would result in higher benefit-to-cost ratios. In the event of budget constraints, the methodology developed in this paper can be used to prioritize the investments based on the benefit-to-cost ratios for the prospective sites

Limited risks of major congenital anomalies in children of mothers with coeliac disease: a population-based cohort study

Objective: To examine major congenital anomaly (CA) risks in children of mothers with coeliac disease (CD) compared with mothers without CD. Design: Population-based cohort study. Setting: Linked maternal–child medical records from a large primary care database from the UK. Population: A total of 562 332 live singletons of mothers with and without CD in 1990–2013. Methods: We calculated the absolute major CA risks in children whose mothers had CD, and whether this was diagnosed or undiagnosed before childbirth. Logistic regression with a generalised estimating equation was used to estimate adjusted odds ratios (aORs) with 95% confidence intervals (95% CIs) for CAs associated with CD. Main outcome measures: Fourteen system-specific major CA groups classified according to the European Surveillance of Congenital Anomalies and neural tube defects (NTDs). Results: Major CA risk in 1880 children of mothers with CD was 293 per 10 000 liveborn singletons, similar to the risk in those without CD (282; aOR 0.98, 95% CI 0.74–1.30). The risk was slightly higher in 971 children, whose mothers were undiagnosed (350; aOR 1.14, 95% CI 0.79–1.64), than in 909 children whose mothers were diagnosed (231; aOR 0.80, 95% CI 0.52–1.24). There was a three-fold increase in nervous system anomalies in the children of mothers with undiagnosed CD (aOR 2.98, 95% CI 1.06–8.33, based on five exposed cases and one had an NTD), and these women were all diagnosed with CD at least 4 years after their children were born. Conclusions: There was no statistically significant increase in risk of major CAs in children of mothers with coeliac disease overall, compared with the general population

Testing the predictability and efficiency of securitized real estate markets

This paper conducts tests of the random walk hypothesis and market efficiency for 14 national public real estate markets. Random walk properties of equity prices influence the return dynamics and determine the trading strategies of investors. To examine the stochastic properties of local real estate index returns and to test the hypothesis that public real estate stock prices follow a random walk, the single variance ratio tests of Lo and MacKinlay (1988) as well as the multiple variance ratio test of Chow and Denning (1993) are employed. Weak-form market efficiency is tested directly using non-parametric runs tests. Empirical evidence shows that weekly stock prices in major securitized real estate markets do not follow a random walk. The empirical findings of return predictability suggest that investors might be able to develop trading strategies allowing them to earn excess returns compared to a buy-and-hold strategy

Further evidence on the (in-) efficiency of the U.S. housing market

Extending the controversial findings from relevant literature on testing the efficient market hypothesis for the U.S. housing market, the results from the monthly and quarterly transaction-based Case-Shiller indices from 1987 to 2009 provide further empirical evidence on the rejection of the weak-form version of efficiency in the U.S. housing market. In addition to conducting parametric and non-parametric tests, we apply technical trading strategies to test whether or not the inefficiencies can be exploited by investors earning excess returns. The empirical findings suggest that investors might be able to obtain excess returns from both autocorrelation- and moving average-based trading strategies compared to a buy-and-hold strategy

Assessment of skill and portability in regional marine biogeochemical models: Role of multiple planktonic groups

Application of biogeochemical models to the study of marine ecosystems is pervasive, yet objective quantification of these models' performance is rare. Here, 12 lower trophic level models of varying complexity are objectively assessed in two distinct regions (equatorial Pacific and Arabian Sea). Each model was run within an identical one-dimensional physical framework. A consistent variational adjoint implementation assimilating chlorophyll-a, nitrate, export, and primary productivity was applied and the same metrics were used to assess model skill. Experiments were performed in which data were assimilated from each site individually and from both sites simultaneously. A cross-validation experiment was also conducted whereby data were assimilated from one site and the resulting optimal parameters were used to generate a simulation for the second site. When a single pelagic regime is considered, the simplest models fit the data as well as those with multiple phytoplankton functional groups. However, those with multiple phytoplankton functional groups produced lower misfits when the models are required to simulate both regimes using identical parameter values. The cross-validation experiments revealed that as long as only a few key biogeochemical parameters were optimized, the models with greater phytoplankton complexity were generally more portable. Furthermore, models with multiple zooplankton compartments did not necessarily outperform models with single zooplankton compartments, even when zooplankton biomass data are assimilated. Finally, even when different models produced similar least squares model-data misfits, they often did so via very different element flow pathways, highlighting the need for more comprehensive data sets that uniquely constrain these pathways

Self-love and sociability: the ‘rudiments of commerce’ in the state of nature

Istvan Hont’s classic work on the theoretical links between the seventeenth-century natural jurists Hugo Grotius and Samuel Pufendorf and the eighteenth-century Scottish political economists remains a popular trope among intellectual and economic historians of various stamps. Despite this, a common criticism levelled at Hont remains his relative lack of engagement with the relationship between religion and economics in the early modern period. This paper challenges this aspect of Hont’s narrative by drawing attention to an alternative, albeit complementary, assessment of the natural jurisprudential heritage of eighteenth-century British political economy. Specifically, the article attempts to map on to Hont’s thesis the Christian Stoic interpretation of Grotius and Pufendorf which has gained greater currency in recent years. In doing so, the paper argues that Grotius and Pufendorf’s contributions to the ‘unsocial sociability’ debate do not necessarily lead directly to the Scottish school of political economists, as is commonly assumed. Instead, it contends that a reconsideration of Grotius and Pufendorf as neo-Stoic theorists, particularly via scrutiny of their respective adaptations of the traditional Stoic theory of oikeiosis, steers us towards the heart of the early English ‘clerical’ Enlightenment