Pareto efficient allocation of an in-motion wireless charging infrastructure for electric vehicles in a multipath network

Electric vehicles (EV) use an eco-friendly technology that limits the greenhouse gas emissions of the transport sector, but the limited battery capacity and the density of the battery are the major barriers to the widespread adoption of EV. To mitigate this, a good method seems to be the innovative wireless charging technology called ‘On-Line EV (OLEV)’, which is a contactless electric power transfer technology. This EV technology has the potential to charge the vehicle’s battery dynamically while the vehicle is in motion. This system helps to reduce not only the size of the battery but also its cost, and it also contributes to extending the driving range before the EV has to stop. The high cost of this technology requires an optimal location of the infrastructure along the route. For this reason, the objective of this paper is to study the problem of the location of the wireless charging infrastructure in a transport network composed of multiple routes between the origin and the destination. To find a strategic solution to this problem, we first and foremost propose a nonlinear integer programming solution to reach a compromise between the cost of the battery, which is related to its capacity, and the cost of installing the power transmitters, while maintaining the quality of the vehicle’s routing. Second, we adapt the multi-objective particle swarm optimization (MPSO) approach to our problem, as the particles were robust in solving nonlinear optimization problems. Since we have a multi-objective problem with two binary variables, we combine the binary and discrete versions of the particle swarm optimization approach with the multi-objective one. The port of Le Havre is presented as a case study to illustrate the proposed methodology. The results are analyzed and discussed in order to point out the efficiency of our resolution method.     

Government spending multipliers in contraction and expansion

This paper investigates the impact of government spending on output and the size of the spending multiplier during periods of output contraction and expansion. It also investigates the impact of spending when the economy hits the nominal zero lower bound. It uses a panel of 21 advanced countries over the period of 1979–2011, applying a TSLS estimation technique. We find a spending multiplier of close to 1 during expansion and values of up to 3 during contractions. However, our results do not indicate a difference in the impact of spending during nominal zero lower bound periods.     

Diversified behavioral portfolio as an alternative to Modern Portfolio Theory

The traditional mean–variance approach has been complemented by alternative theories that use risk measures different from standard deviation of returns or involve additional distributional features of returns like skewness and kurtosis. We propose a portfolio choice model that combines different distributional characteristics of the returns in the decision-making making process, considering preferences of investors which are modeled as non-statistical uncertainties of investors using fuzzy theory. We use 20 stocks of the S&P500 from January 2013 to December 2017. We assess the obtained portfolios’ performance, and the diversified behavioral portfolios outperform than the mean–variance portfolio. This methodological proposal can be seen as a strong managerial tool to make investment portfolio decisions.     

REGIME DEPENDENT EFFECT OF OUTPUT GROWTH ON OUTPUT GROWTH UNCERTAINTY: EVIDENCE FROM OECD COUNTRIES

This paper studies the impact of output growth on output growth uncertainty by considering two important issues hitherto not properly and adequately addressed to in the existing empirical studies specifying this relationship. These are: (i) the possible existence of a threshold level of output growth, and the consequent identification of two regimes characterized by high and low output growth, and (ii) whether or not the coefficient capturing the causal link is different in these two output growth states. This paper proposes a regime switching model to study this asymmetric effect for 16 OECD countries. Based on monthly time‐series observations, our results strongly support that the impact varies significantly between the two output growth regimes with the coefficient in the high growth regime being negative for majority of the countries.     

Appropriate assumption on cross-hauling national input–output table regionalization

Input–output tables are useful for regional economic analyses. Although scholars often regionalize national input–output tables, cost-related issues make surveying regional trade flow difficult; hence, non-survey approaches are implemented instead. While location quotient (LQ) approaches have been used widely, they ignore cross-hauling in interregional trade. Therefore, alternative non-survey approaches with different assumptions on cross-hauling are used, such as cross-hauling depends on regional size and cross-hauling is proportional to its potential determined by output or demand. This study concludes that the most appropriate assumption, as per the relative performance of non-survey approaches, is that cross-hauling is in proportion to trade volume.     

集装箱船初稳性高度优化模型的建立

为解决目前集装箱配积载中尚需结合人工经验来进行箱位选配的问题,通过研究集装箱船配积载前重心距基线高,运用集装箱船初稳性高度计算原理,结合集装箱船的结构特点,建立集装箱船初稳性高度优化模型。运用交互式的线性和通用优化求解器编写程序,其研究成果将为实现集装箱船自动化配积载目标提供理论基础。     

Stochastic regularization for the mean-variance allocation scheme

Despite being based on sound principles, the original Markovitz portfolio allocation theory cannot produce sound allocations, and restrictions or modifications need to be imposed from outside the theory in order to obtain meaningful portfolios. This is unsatisfactory, and the reasons for this failure are discussed, in particular, the unavoidable small eigenvalues of the covariance. Within the original principles of risk minimization and return maximization, several modifications of the original theory are introduced. First, the strategic and tactical time horizons are separated. A base long-term allocation is chosen at the strategic time horizon, while the portfolio is optimized at the tactical time horizon using information from the price histories. Second, the tactical portfolio is financed by the strategic one, and a funding operator is introduced. The corresponding optimal allocation (without constraints) has one free parameter fixing the leverage. Third, the transaction costs are taken into account. This includes the current re-allocation cost, but crucially the expected costs of the next reallocation. This last term depends on the sensitivity of the allocation with respect to the covariance, and the expectation introduces another dependency on the (inverse) covariance. The new term regularizes the original minimization problem by modifying the lower part of the spectrum of the covariance, leading to meaningful portfolios. Without constraints, the final Lagrangian can be minimized analytically, with a solution that has a structure similar to the original Markovitz solution, but with the inverse covariance regularized by the expected transaction costs.     

湘桂铁路下穿全兴高速公路设计方案优化

新建湘桂铁路于DK233+503处下穿全兴高速公路,原设计采用顶进框架桥方案。通过对安全质量的可控性、经济、工期等方面进行综合比选,取消顶进框架桥,变更为公路箱梁桥上跨铁路方案,采用分幅封道、分幅施工,既安全快速地穿过全兴高速公路,又创造了良好的经济效益和社会效益,为类似的工程提供了一定的参考价值。     

山区高速公路施工成本控制——优化大临工程及设计方案节约施工成本

本文以承秦高速三标为背景,通过优化施工便道、临时电力、弃土场、拌和站、梁场等大临工程施工方案,优化隧道、桥梁设计方案,有效降低了施工成本,取得了较好的经济效益,对山区高速公路施工成本管理有一定的借鉴意义。     

如何进一步优化“哑铃式”生产工艺

煤炭科研院所转制后的企业大多采用"哑铃式"生产模式,即设计、组装(生产的两头)由自身控制,中间加工环节放在各外委厂家加工,以避免科研院所自身加工生产条件不足的缺陷,在转制起始阶段能迅速组织生产,形成较为快速的经济增长。但随着产品品种逐渐增多、产品生产数量日益增加,采用本模式的生产工艺逐步暴露出一定的缺陷,如:产品质量的不稳定、产品库存的积压、产品成本的增加等等一系列问题。因此本文将通过对多种新产生问题的分析,提出进一步优化"哑铃式"生产工艺的方法。