Selecting sustainable electric bus powertrains using multipreference evolutionary algorithms

Constant improvement of vehicle technologies towards more efficient powertrains and reduced pollutant emissions, frequently leads to the increase of the vehicle or fuel costs, compromising its viability. Multi-objective optimization methods are commonly used to solve such problems, finding optimal trade-off solutions relatively conflicting objectives. Nevertheless, vehicle driving performance, is often disregarded from the optimization process or considered only as a fixed constraint. This may raise some issues, which are discussed in this paper: (a) vehicle dynamics are not improved, (b) trade-off optimal solutions are not distinguishable, (c) interesting solutions near constraints limits won´t be considered if constraints are not marginally relaxed.

This paper proposes a method to optimize three electric-drive vehicle options for an urban bus, a battery electric (BEV), a fuel cell hybrid (FC-HEV) and a plug-in hybrid (FC-PHEV), aiming minimum carbon footprint, maximum financial indicator and simultaneously improved driving performance (speed, acceleration, and electric range). The carbon footprint is assessed by a life cycle (LC) approach, considering the impact of the fuel production and use, and vehicle embodied materials; while the financial assessment considers the vehicle and fuel costs. The spherical pruning multi-objective differential evolution algorithm (spMODE-II) is used in the optimization, considering different preference regions within the problem constraints and objectives. The vehicle solutions optimality and suitability are compared with other multi-objective algorithm, NSGA-II.

The FC-HEV achieved the lowest LC emissions (547 g/km), and the FC-PHEV the maximum financial gain (0.19 $/km), while the BEV achieved the best trade-off of solutions.     

Users' satisfaction evolution of a metropolitan transit system in a context of economic downturn

As the worldwide financial crisis is directly connected to the transport sector, public transport systems become a central player to support economic recovery. Transit services are facing a number of challenges as a consequence of this severe crisis. However, each attribute characterizing transit services has evolved in a different manner, thereby raising some chances and opportunities at some specific areas. This study investigates the evolution of service quality on a metropolitan transit system under economic crisis conditions. We used data from three customer satisfaction surveys (2008, 2011, and 2014) conducted at the bus transit service of the metropolitan area of Granada (Spain). Principal component analysis (PCA) and structural equation modeling (SEM) approaches were applied. PCA results show that the attributes describing the service were grouped into two levels of dimensions according to their impact on users' overall satisfaction (Transport Service Factors and Comfort and Convenience Factors). Subsequently, following a competing model strategy, the existing relationships between users' satisfaction and perception of service quality dimensions were ascertained. Finally, three SEMs were calibrated, one for each year under study, and were subjected to a multigroup analysis to test for equivalence among the three models. The outcomes show that fare of the ticket has lost importance as the financial crisis has become more noticeable and that Transport Service Factors had lower influence and users' satisfaction in 2011, when downturn was more intense.     

Fragmentation and Market Quality: The Case of European Markets

This paper questions whether the proliferation of alternative trading venues in Western Europe after MiFID implementation in 2007 affected market quality. By means of a difference-in-differences analysis, we evaluate changes in market quality of stocks that initiated trading in Multilateral Trading Facilities (MTF) in relation to matched samples. Our analysis provides evidence that the overall liquidity (measured by transaction costs and price impact) and trading activity increased in the short term with trade initiation in MTF. Notably, we show that fragmentation did not cause lower price precision or informativeness, but some tests suggest that fragmentation correlates positively with volatility. The results of this study are stronger for stocks with greater propensity for MTF trade initiation, i.e. stocks with greater size and liquidity prior to that event. Interestingly, the impact on liquidity and trading activity varied across stock exchanges and timing of MTF trade initiation. As for long run effects, our results suggest an improvement of overall liquidity and a neutral effect on the trading activity of traditional exchanges.     

Impact of the stock market capitalization and the banking spread in growth and development in Latin American: A panel data estimation with System GMM

This research is aimed at assessing the impact of the stock market capitalization and the banking spread in per capita economic growth (as a proxy of economic development) in the major Latin American economies during period 1994–2012. To do this, a panel data model is estimated with both system and difference Generalized Method of Moments. The main empirical findings are that economic growth in the countries under study is positively impacted by the stock market capitalization and negatively by the banking spread. Typical problems of multicollinearity and autocorrelation appearing in panel data analysis are corrected under the proposed methodology.     

Entry and Bidding in Common and Private Value Auctions with an Unknown Number of Rivals

In many procurement auctions bidders do not know how many rivals they face at the time that they incur the cost of preparing their bids. We show in a theoretical model that regardless of whether the procurement is characterized by private or by common values an increase in the potential number of bidders may lead to higher procurement costs. This raises potential policy questions of whether and how entry should be encouraged or limited in public procurement auctions. We use evidence from auctions of construction contracts to estimate the effect of an increase in the pool of potential bidders on entry and auction prices when entry and bidding decisions are made sequentially with no knowledge of the number or identity of the actual competitors.     

Taking operations strategy into practice: Developing a process for defining priorities and performance measures

Enterprises’ operations systems and environments, characterized by their complexity and dynamics, are challenging operations strategic management models. The study presented in this paper develops a process to integrate operations strategy content to operations performance measurement system design. Essentially, the developed methodology is based on Process Approach (Cambridge Approach) technique that systematizes procedures for generating a performance measures set coherent to operations strategy objectives and also produces a consistent strategy implementation process. To illustrate the development and the application of the proposed design methodology, findings of two case studies related to telecom engineering services companies are used. Results are discussed focusing on testing the proposed methodology in terms of its feasibility, usability, and utility. A refined process, organized in phases, steps, and procedures, is the final result of the presented study.     

Debt crisis and 10-year sovereign yields in Ireland and in Portugal

We assess the determinants of the 10-year sovereign yield for the period 2000–2015, in Portugal and in Ireland. Results show that the long-term Portuguese sovereign yield increased with the rise of the 10-year Bund yield and during the Securities Markets Programme, but decreased due to financial integration. Additionally, during the period of the economic and financial adjustment programme, there was evidence of additional rises (decreases) due to increases (decreases) in the 3-month Euribor rate, and the level of public debt. EU/IMF funding reduced sovereign yield.     

Some unpleasant currency-devaluation arithmetic in a post Keynesian macromodel

The conventional view argues that devaluation increases the price competitiveness of domestic goods, thus allowing the economy to achieve a higher level of economic activity. However, these theoretical treatments largely neglect two important effects following devaluation: (1) the inflationary impact on the price of imported intermediate inputs, which raises the prime costs of firms and deteriorates partially or totally their price competitiveness; and (2) the redistribution of income from wages to profits, which ambiguously affects the aggregate demand as workers and capitalists have different propensities to save. New structuralist economists have explored these stylized facts neglected by the orthodox literature and, by and large, conclude that devaluation has contractionary effects on growth and positive effects on the external balance. Given that empirical evidence on the correlation between devaluation and growth is quite mixed, we develop a more general Keynesian–Kaleckian model that takes into account both opposing views in order to analyze the net impact of currency depreciation on the short-run growth rate and the current account. We demonstrate that this impact can go either way, depending on several conditions such as the type of growth regime, that is, wage-led or profit-led, and the degree of international price competitiveness of domestic goods.     

Interregional redistribution as a cure to the soft budget syndrome in federations

The soft budget syndrome is ubiquitous in federations. It emerges whenever a high tier in a fiscal system provides extra resources to a lower tier to prevent the latter from failing to reach a mutually agreeable predetermined target. Interregional income redistribution is also an endemic feature of most federations. We show that the center’s ability of making interregional transfers ex-ante and ex-post cures the soft budget syndrome whenever the center is perfectly informed ex post. Under these circumstances, the interregional transfer scheme makes it a dominant strategy for each regional government to truthfully reveal its privately held information ex-ante.