Direct yaw moment control and power consumption of in-wheel motor vehicle in steady-state turning

Driving force distribution control is one of the characteristic performance aspects of in-wheel motor vehicles and various methods have been developed to control direct yaw moment while turning. However, while these controls significantly enhance vehicle dynamic performance, the additional power required to control vehicle motion still remains to be clarified. This paper constructed new formulae of the mechanism by which direct yaw moment alters the cornering resistance and mechanical power of all wheels based on a simple bicycle model, including the electric loss of the motors and the inverters. These formulation results were validated by an actual test vehicle equipped with in-wheel motors in steady-state turning. The validated theory was also applied to a comparison of several different driving force distribution mechanisms from the standpoint of innate mechanical power.     

Parametric rolling prediction in irregular seas using combination of deterministic ship dynamics and probabilistic wave theory

In recent years there have been reports of serious accidents of parametric rolling for modern container ships and car carriers. For avoiding such accidents, a prediction method of parametric rolling in irregular seas is required. Since parametric rolling is practically non-ergodic, repetitions of numerical simulations or experiments could be not feasible to ascertain the behaviour. Therefore, in this paper, a method combining a stochastic approach with a deterministic approach in order to estimate the probabilistic index without such simple repetitions is developed. The ship's response in regular seas is estimated by solving an averaged system of the original 1-DoF roll model, and random waves necessary for occurrence of parametric rolling is achieved by using Longuet-Higgins’s or Kimura’s wave group theory. As a result, a fast and robust computation method of the probabilistic index is established. Finally, it is concluded that the proposed method is considered to be one of the useful tools for discussing the new IMO Intact Stability Code.     

The role of children’s independent mobility and social media use for face-to-face social interaction with friends

Transportation - Social interaction with friends is an important contributor to children’s well-being, but how transport affects this is rarely studied. For two or more children (not of the...     

Persuasive communication aimed at public transportation-oriented residential choice and the promotion of public transport

In this study, we developed a persuasive communication program to induce public-transport-oriented residential (PTOR) choice. We implemented an experiment that targeted students from the University of Tsukuba, Japan, who were in the process of changing their residential location. These students were randomly assigned to four groups: the first group was a control group; the second group received an information brochure about apartment flats typically used by students in Tsukuba city; the third group received a brochure identical to the one given to the second group, except that it also included information about the level of bus service for every flat; and the fourth group was provided with a leaflet that provided motivation for PTOR choice, in addition to the brochure used for the third group. The residential locations were investigated 5 months after the intervention. There was a significant difference between the control group and the third and fourth groups. The ratio of PTOR choice in the group with the information was twice as high as that for the control group. Furthermore, the persuasive message also increased PTOR choice. Additionally, the target groups’ frequency of bus use from home or the university was significantly high compared with the control group.     

Limits to resources, economic growth and happiness

Terrible scenario for the future aspect of our society was issued by “The Limits to Growth”. Basic problems that we confront are the restricted natural resources and the environment. Regarding the resources, the overall average of the reserve/production ratio is predicted to fall below 10 years by 2040. Aggressive developments of mines based on the sense of urgency for metal resources cause strong confliction with the environment and the people living there. Resultantly, urban mine becomes more realistic than before. From the view point of ecological foot print, 5.3 globes are needed if all the people living in the world attain the affluent life same as USA. On the other hand, it is clear that we can get larger utility by smaller goods if our scale of satisfaction is reduced. We have to notice that happiness is our ultimate purpose, economy and industry are intermediate, and natural resources support the all from the basis.     

Assessment of ship evacuations in response to pending tsunamis

Earthquakes occur due to friction between two geological plates. Historically, numerous earthquakes have occurred in the southern Sea of Japan. As of January 2008, the estimated probability of occurrence of the next Nankai or Tonankai earthquake within the next 30 years has been set at 50 or 60–70%, respectively. Should either of these earthquakes occur, a tsunami resulting in great horizontal movement and force could also result, setting numerous vessels adrift inside ports, causing destruction to port facilities, and endangering human life inside the vessels. Thus, appropriate countermeasures are required for ships because they may be forced to change locations unexpectedly. To minimize the probability of disaster should a tsunami forecast be issued, all vessels in Osaka Bay will need to evacuate immediately and proceed to safe anchorage areas before the tsunami arrives. However, the orderly evacuation of ships to safe anchorage areas would face difficulties due to traffic density within the Osaka Port area, and so appropriate improvements to ship traffic management are required. In this paper, several vessel-related issues, such as inter-ship distances, evacuation order procedures prior to the arrival of the first tsunami, and the first peak tsunami arrival time, are evaluated using general discrete event simulation.     

Case study on health assessments related to a modal shift in transportation

Historically, the emphasis on environmental problems has been on visible pollution. However, as a result of the reduction in visible pollution in recent years, many people have become anxious about invisible dangers. The method for objectively evaluating these invisible dangers is risk assessment. Therefore, in the present study we propose and discuss a method for evaluating the influence of a modal shift in transportation on cancer risk using the technique of risk assessment. First, two representative transportation routes were selected for analysis. Subsequently, the level of airborne carcinogens from the exhaust of ships and trucks was determined. Next, the concentration of each carcinogen in locations across Japan was calculated. Finally, the number of people in Japan who will suffer from cancer related to these emissions was derived and the effects of the modal shift on health are discussed.     

Development of ship sinking frequency model over Subsea Pipeline for Madura Strait using AIS data

It is important to study the risk posed by heavy shipping traffic to a subsea pipeline located near an industrial port area. In this context, it is essential to estimate the accident frequency in an attempt to eliminate subjectivity in the analysis process. This study proposes a model for estimating the ship sinking frequency over the subsea pipeline in the Madura Strait area. The Madura Strait is one of the busiest shipping lanes in Indonesia. Many ships pass through the fairway in the strait, and many industrial ports have been built in this area. The proposed model is developed based on Fujii’s Model, and it uses Automatic Identification System (AIS) data as a ship traffic survey. Ship sinking accidents are considered based on ship–ship collisions over the critical subsea pipeline area. The ship–ship collision locations around the subsea pipeline and the ship traffic distribution models are estimated using AIS data. The causation probability Pc is determined based on a synthetics approach using a Bayesian network modified from Det Norske Veritas’ and Hänninen’s models. The causation probability is estimated by considering factors such as human performance, weather, technical problems, and support. The proposed model is validated by comparing its result with actual accident records for the Madura Strait area. The ratio value of 0.33 is considered to be reasonably agreement (ratio value ≥0.2).     

Promoting Public Transport Using Marketing Techniques in Mobility Management and Verifying their Quantitative Effects

Mobility management (MM) is a transportation management policy that uses “soft” measures to attempt to reduce car use and promote sustainable transportation modes such as public transport, bicycles, and walking. Using communication and other means, MM induces voluntarily change towards more sustainable transportation modes. We implemented MM marketing to promote an experimental community bus service. This project had two components: a questionnaire conducted in the service area and a monthly newsletter. The questionnaire was more than a survey; it also communicated information about the bus and helped promote bus use. One month after the survey, we implemented a follow-up survey targeting the initial survey respondents. Results suggest that the MM program produced a general increase in bus use, as well as mouth-to-mouth advertising, that helped promote bus use.