Dynamic analysis of energy storage unit of the hydraulic hybrid vehicle

A new configuration of hydraulic hybrid vehicle (HHV) was presented, which mainly consists of an engine, high-pressure accumulator, lower-pressure reservoir and hydraulic transformer (HT) connected to common pressure rail (CPR), and the working principle of hydraulic hybrid vehicle has been described to extend its energy-regenerated potential. Moreover, the mathematical models of the instantaneous pressure ratio of HT and the characteristic parameters of parallel and series accumulator (i.e. effective volume, specific energy, and charge-discharge efficiency) based on lumped parameters method were built, respectively. The simulation and experimental tests of dynamic characteristics of HT and accumulator were done, the result shows that the theoretical analysis was the same as the experimental results by comparing them in the curve trend, and the series accumulator was much superior to parallel accumulator in terms of pulsation damping of hydraulic transformer, that is the simulation results reasonably and appropriately.     

Real-time catenary models for the hardware-in-the-loop simulation of the pantograph–catenary interaction

Hardware-in-the-loop (HIL) simulation is a promising technique to study the pantograph–catenary interaction problems by realising the interaction of a physical pantograph with a mathematical model of the overhead equipment (catenary). However, the computing power presently available on real-time CPUs only allows to run simplified models of the overhead equipment. Therefore, it is important to define catenary models that are suitable for real-time simulation and at the same time capable of accurately representing the dynamic behaviour of the catenary. In this paper, the use of a catenary model based on modal superposition is considered, and the effect of changing the number of modelled spans and the number of modal components allocated to the contact and messenger wires is investigated in view of finding the best model compatible with real-time simulation. Comparisons between HIL simulation results and line measurements are presented, to quantify the accuracy of the hybrid simulation method developed.     

Intelligent speed adaptation: Preliminary results of on-road study in Penang,Malaysia

The first field experiment with intelligent speed adaptation (ISA) in Malaysia was held in December 2010 in the State of Penang. Eleven private cars were instrumented with an advisory system. The system used in the present study included a vocal warning message and a visual text message that is activated when the driver attempts to exceed the speed limit. When the driver decreases the speed, the warning stops; otherwise it is continuously repeated. The test drivers drove the vehicles for three months with the installed system, and the speed was continuously logged in all vehicles. The warning was however only activated in the second month of the three month period. The present study aimed to evaluate the effects of an advisory ISA on driving speed, traffic safety, and drivers' attitude, behavior, and acceptance of the system. To examine these effects, both the survey and the logged speed data were analyzed and explored. The results show a significant reduction in the mean, maximum and 85th percentile speed due to the use of the system. However, there was no long-lasting effect on the speed when the system was deactivated. In the post-trial survey, drivers declared that the system helped them well in following the speed limits and that it assisted them in driving more comfortably. Furthermore, the warning method was more accepted compared to a supportive system, such as active accelerator pedal (AAP). After the trial, most drivers were willing to keep an ISA system.     

Some properties of international maritime statistics

This paper tests two fundamental hypotheses concerning international maritime statistics. The first one deals with the question of stationary of the maritime market statistics. The second hypothesis tested is the assumption that the international maritime statistical time series are not distributed according to a normal of Guassian probability law, but rather belong to the same family of distributions with distinctly different critical parameters. Through well documented statistical methods, the paper concludes that the international freight rates observed on a day to day basis are generated by a random walk process. The paper finds that the shipping industry's conventioal wisdom is essentially correct. ‘Last done’ is as good a forecast of tomorrow's freight rate as any other generated by more sophisticated forecasting methods. Furthermore, freight rates and secondhand tonnage prices fluctuate closely together. The freight rates are generated by stochastic processes fully described by the Paretian family of distributions. The critical parameters of these distribution, the characteristic exponents, are such that the risk conscious ship operator can indeed reduce his exposure to risk by securing a correct set of freight rate contracts.     

Maritime economics in a Post-Expansion Panama Canal Era

Government recently introduced the Transport Law Reform Bill, which if passed by Parliament, will allow foreign vessels to uplift and discharge cargoes and passengers along the coast of New Zealand. Coastal shipping is part of the domestic transport industry, which has benefitted from deregulation and considerable restructuring over the last decade. This paper provides a brief review of the coastal shipping industry in New Zealand and an overview of international cabotage laws. An alternative open coast shipping policy proposed by the New Zealand Shipping Federation, which is based on ‘level playing fields’ principles, is presented. The scope of cost benefit analysis is outlined and the potential costs and the potential costs and benefits of the Government's open coast shipping policy are summarized. Despite the potential costs to New Zealand of an open coast policy appearing to be considerably greater than the potential benefits. Government officials have not undertaken an empirical cost benefit analysis. The paperr concludes that hte clauses of the Transport Law Reform Bill relating to an open coast policy should be withdrawn and a full empirical cost benefit analysis should be undertaken to determine the best coastal shipping policy for New Zealand.     

Accommodating perceptual conditioning in the valuation of expected travel time savings for cars and public transport

Travel time variability (i.e., random variations in travel time) leads to a travel time distribution for a repeated trip from a fixed origin to destination (e.g., from home to work). To represent travel time variability, a series of possible travel times per alternative (departure time, route or mode) are often used in stated choice experiments. In the traditional models, the probabilities associated with different travel scenarios (e.g., arriving early, on time and late) shown in the experiments are directly used as weights. However, evidence from psychology suggests that the shown probabilities may be transformed (underweighted or overweighted) by respondents. To account for this transformation of probabilities, this study incorporates perceptual conditioning through a non-linear probability weighting function into a utility maximisation framework, within which the empirical estimate of the value of expected travel time savings is estimated. The key advantage of this framework is that the estimated willingness to pay value can be directly linked to the source of utility (i.e., the probability distribution of travel time), while taking into account the perceptual transformation of probabilities.     

Catalyzing Coastal Management in Kenya and Zanzibar: Building Capacity and Commitment

Site-based projects were initiated in Chawka Bay-Paje, Zanzibar, and Nyali-Bamburi-Shanzu, Kenya, to demonstrate the benefits of an integrated coastal management (ICM) approach for addressing coastal issues such as tourism development and enhancement of resource-dependent village economies in eastern Africa. A two-year, multidonor project used three primary strategies to make rapid, but sustainable, progress toward ICM. These included using interagency government teams for ICM planning, adopting an internationally recognized framework for ICM as a project ''road map,'' and explicitly incorporating capacity-building strategies into all aspects of the project. Within two years, integrated ICM action strategies, prepared through participatory processes, were being implemented at both sites, and both teams were working to expand the scale and scope of ICM in their nation. More importantly, the project helped create committed, capable, interagency groups that continue to work together to address urgent ICM issues.     

Coastal Resources as an Engine of Economic Growth and Reduction of Poverty in West Africa: Policy Considerations

This article synthesizes lessons and outcomes from the second international Coastal Zone Asia-Pacific conference (CZAP) on “Improving the Quality of Life in Coastal Areas,” held in Brisbane in September 2004. The conference theme was chosen as a follow-up from the first CZAP that identified priority actions in response to the increasing recognition of social issues in coastal management, particularly those aiming to improve the state of the coastal areas in the Asia-Pacific region. The second CZAP explored the “quality of life” theme by placing emphasis on rectifying coastal poverty, sustaining livelihoods, and protecting cultural heritage. Mechanisms to address these issues were explored through international agreements, participatory research, capacity building, and education, as well as the continuing need for integrated planning, environmental management, and effective monitoring and evaluation. A post-conference survey showed that the second CZAP resulted in 122 initiatives (82 underway and another 40 planned) to progress the improvement of quality of life in coastal areas. These initiatives ranged from the establishment of a unit that is responsible for river basin and coastal zone management by the Thua Thien Hue provincial government in Vietnam, to a collaborative on-ground livelihoods project between NGOs, government, and financial institutions on coastal zone management facilitated by the Asian Development Bank. However, the authors argue that two key challenges for ICM in the Asia-Pacific region remain. These challenges relate to the effective monitoring and evaluation of ICM initiatives, as well as matching future ICM initiatives to emergent priority areas.     

An Assessment of Coastal Development and Land Use Change Using the DPSIR Framework: Case Studies from the Eastern Cape,South Africa

Coastal areas are experiencing high levels of development, largely driven by a number of aesthetic and recreational factors, increased mobility, availability of disposable income for middle and upper income groups and the promise of job opportunities and improved economic well-being for lower income groups. As existing coastal urban nodes expand development “shifts” to less developed areas and places increasing pressure on the surrounding natural environment. This article considers the coastal zone of two municipalities in the Eastern Cape, South Africa, with similar environmental characteristics but disparate socioeconomic and governance histories. It identifies and integrates the drivers of development and land use change in the coastal zone of these municipalities by means of an adapted Driver-Pressure-State-Impact-Response (DPSIR) Framework. Development and land use change are driven by a combination of social, economic, and legislative factors that need to be considered for future management and planning in this unique dynamic system.     

Spatial and Temporal Modeling of Beach Use: A Case Study of East Anglia,UK

As tourists are sensitive to weather conditions and changes to the environments they visit, it is likely that climate change will affect coastal recreation in the future. To understand these impacts, it is first important to quantify how visitor numbers are associated with beach characteristics and weather patterns. Using the East Anglian coastline, UK, as a case study, information on the spatial distribution of visitors recorded from aircraft flights is combined with beach characteristic data in a Geographical Information System. In addition, surveys are undertaken at two beaches to assess temporal variations in visitation. The study finds a diverse range of characteristics are associated with visitor numbers. These findings are evaluated alongside the anticipated effects of climate change and management policies. Although it is predicted that warmer weather will increase visitor numbers overall, sea-level rise may reduce numbers at wide sandy beaches, which are currently most preferred by tourists.