On planning dissaturation control signals for urban areas

The problem of the optimal control of an oversaturated intersection, originally proposed by Gazis and Potts (1965), is reviewed and a feedback solution is obtained for a multi-stream pattern under general assumptions on the variability of input flows and control constraints. The dissaturation control problem is solved in two steps: first, the least dissaturation time is evaluated by taking into account the green split constraints; then a minimum waiting time problem over the least dissaturation horizon is solved to select the optimal output rate pattern.     

Trends in vehicle motion control for automated driving on public roads

ABSTRACT

In this paper, we describe how vehicle systems and the vehicle motion control are affected by automated driving on public roads. We describe the redundancy needed for a road vehicle to meet certain safety goals. The concept of system safety as well as system solutions to fault tolerant actuation of steering and braking and the associated fault tolerant power supply is described. Notably restriction of the operational domain in case of reduced capability of the driving automation system is discussed. Further we consider path tracking, state estimation of vehicle motion control required for automated driving as well as an example of a minimum risk manoeuver and redundant steering by means of differential braking. The steering by differential braking could offer heterogeneous or dissimilar redundancy that complements the redundancy of described fault tolerant steering systems for driving automation equipped vehicles. Finally, the important topic of verification of driving automation systems is addressed.     

Market structures and competitive strategies: the carrier–stevedore arm-wrestling in northern European ports

Over the last few years, liner and stevedoring markets have been facing new challenges. The progressive concentration on the demand side (carriers) and the emergence of global alliances in the mid-1990s have triggered a similar process of consolidation on the supply side (stevedores). In turn, more recently, the strategic choices of pure terminal operators have led to the progressive involvement of carriers in port operations, both from a financial and a managerial point of view. This paper aims at analysing the current contest in northern Europe between customers and suppliers of port services. Substantial concentration in the stevedoring market and the emergence of dedicated facilities in that area, make this arm-wrestling stronger and stronger.

At present, the liner market is following a number of strategic directions including the pursuit of economies of scale (larger vessels) and the supply of services using faster vessels (deployment of ‘fewer’ assets) in order to offer either new services or additional loops (scope). By exploring the strategic behaviours of the top carriers (‘bigger’ or ‘more effective’), the paper attempts to outline the future evolution of the two industries in a 2015 vision, highlighting in particular scenarios for north European ports. Global alliances are weakening and a new era of M&As is probably approaching: how will the bargaining power change between port users and port customers? Which competitive paradigm will dominate?     

The seafaring labour market in Brazil

The most recent reports on the supply and demand for seafarers suggest that there is an increasing lack of officers for the expanding world's merchant fleet. With a focus on Brazil, this paper discusses a particular seafaring labour market highlighting specific challenges that need to be overcome. The paper looks into the current condition of the imbalance in Brazilian seafaring labour market as well as the prospects for merchant marine officers from the only two maritime schools in the country. Key issues on demand forecast and supply expectation, policy amendment, promoting maritime career, sea career commitment and maritime career empowerment are discussed to illustrate possible means to overcome the imbalance.     

Comparison of direct and indirect methods for minimum lap time optimal control problems

Minimum lap time simulations are especially important in the design, optimisation and setup of race vehicles. Such problems usually come in different flavours, e.g. quasi-steady state models vs. full dynamic models and pre-defined (fixed) trajectory problems vs. free trajectory problems. This work is focused on full dynamic models with free trajectory. Practical solution techniques include direct methods (i.e. solution of an nonlinear programming problem problem, widespread approach) and indirect method (i.e. based on Pontryagin's principle, less common, yet quite efficient in some cases). In this contribution the performance of the direct and indirect methods are compared in a number of vehicle-related problems.     

Spatial multi-criteria assessment of potential lead markets for electrified vehicles in Europe

This study presents a modeling approach that focuses on the identification of potential lead markets for electric-drive vehicles (EDVs) in Europe. It is based on a combination of several selected economic, social, environmental, and transport-related factors. The modeling approach is implemented in a GIS-based multi-criteria decision support process with fuzzy measures, enabling an assessment at different spatial and temporal scales under different EDV market penetration scenarios for Europe. The decision support system embeds a multi-criteria analysis based on selected expert-weighted market penetration drivers. The spatial scale chosen for the application of the decision support process are NUTS2 regions and cities within EU27 member states. Three scenarios are investigated, a business as usual, a moderate change, and an accelerated innovation scenario. Across the scenario horizon, it is shown how lead regions for EDVs will be changing in time between first early-adopter areas towards other long-term potential lead regions, depending on the evolution of the market drivers. The European regions and cities which will have a higher lead market potential score in 2020 and 2030 are identified. Our model solution suggests that with the business-as-usual scenario there will be a few insular lead market areas in 2020 and a relatively limited number of more connected lead regions in 2030. The other two scenarios explored suggest a more positive picture leading for the case of the 2030 accelerated scenario to a wide distribution of EDVs across most of Germany, the Netherlands, France, the UK, Ireland, and Italy. The cities of London, Madrid, Berlin and Rome would show high EDV sales under this scenario.     

Market structures and competitive strategies: the carrier-stevedore arm-wrestling in northern European ports

Over the last few years, liner and stevedoring markets have been facing new challenges. The progressive concentration on the demand side (carriers) and the emergence of global alliances in the mid-1990s have triggered a similar process of consolidation on the supply side (stevedores). In turn, more recently, the strategic choices of pure terminal operators have led to the progressive involvement of carriers in port operations, both from a financial and a managerial point of view. This paper aims at analysing the current contest in northern Europe between customers and suppliers of port services. Substantial concentration in the stevedoring market and the emergence of dedicated facilities in that area, make this arm-wrestling stronger and stronger.

At present, the liner market is following a number of strategic directions including the pursuit of economies of scale (larger vessels) and the supply of services using faster vessels (deployment of 'fewer' assets) in order to offer either new services or additional loops (scope). By exploring the strategic behaviours of the top carriers ('bigger' or 'more effective'), the paper attempts to outline the future evolution of the two industries in a 2015 vision, highlighting in particular scenarios for north European ports. Global alliances are weakening and a new era of M&As is probably approaching: how will the bargaining power change between port users and port customers? Which competitive paradigm will dominate?     

锰的发育毒性

机体过量的锰暴露会导致进行性、持久性和神经变性的损害,严重者出现帕金森氏病样症状。锰对体外培养的胚胎神经细胞分化有抑制作用;锰可通过动物胎盘屏障进入胎儿体内,透过血脑屏障沉积于脑,引起脑形态学、生物化学和微量元素分布异常,神经行为机能障碍;人群调查显示母亲职业性接触锰可能会对子女智力产生有害的影响。因此,深入探讨锰的发育毒性,对保护工人及其子女身心健康具有十分重要的意义。     

On the Experimental Analysis of Integral Sliding Modes for Yaw Rate and Sideslip Control of an Electric Vehicle with Multiple Motors

With the advent of electric vehicles with multiple motors, the steady-state and transient cornering responses can be designed and implemented through the continuous torque control of the individual wheels, i.e., torque-vectoring or direct yaw moment control. The literature includes several papers on sliding mode control theory for torque-vectoring, but the experimental investigation is so far limited. More importantly, to the knowledge of the authors, the experimental comparison of direct yaw moment control based on sliding modes and typical controllers used for stability control in production vehicles is missing. This paper aims to reduce this gap by presenting and analyzing an integral sliding mode controller for concurrent yaw rate and sideslip control. A new driving mode, the Enhanced Sport mode, is proposed, inducing sustained high values of sideslip angle, which can be limited to a specified threshold. The system is experimentally assessed on a four-wheel-drive electric vehicle. The performance of the integral sliding mode controller is compared with that of a linear quadratic regulator during step steer tests. The results show that the integral sliding mode controller significantly enhances the tracking performance and yaw damping compared to the more conventional linear quadratic regulator based on an augmented singletrack vehicle model formulation.