Fisheries in Iwaki after the Fukushima Dai'ichi Nuclear Accident: Lessons for Coastal Management under Conditions of High Uncertainty?

This article evaluates factors driving perception of risk and uncertainty in fisheries in Iwaki City, Fukushima Prefecture, Japan, following the Fukushima Dai'ichi nuclear accident. Particular attention is paid to lessons that may be learned for managing uncertainties and risks in coastal management more generally. The 2011 accident has had profound effects on Fukushima fisheries. Commercial coastal fisheries have been stopped since, and efforts to understand and monitor the effects of marine radioactive contamination on produce from the sea continue. Small-scale trial fisheries have, however, re-commenced with a view to gradually re-starting Fukushima fisheries over time. Drawing on in-depth interviews, discussion groups, and field observations from Iwaki and Fukushima Prefecture more widely, three factors are discussed: the role of trusted local-level points of contact; the value of transparent monitoring and screening that acknowledges remaining limitations and uncertainties; and the importance of taking seriously the cultural dimensions of rapid and potentially irreversible environmental change.     

A Sliding Mode Controller for Wheel Slip Ratio Control System

A sliding mode controller has been developed for a wheel slip ratio control system for commercial vehicles with sluggish braking actuators to replace conventional if-then rule-like ABS control laws. New techniques overcome the tendency of sliding mode controllers to chatter. Computer simulation (hardware-in-the-loop simulation) and actual vehicle tests verified the effectiveness of this method to suppress chattering and keep the wheel slip ratio in a desirable range during braking on low-friction road surfaces.     

International Learning Pathways for Coastal Professionals: A Japan–UK Example

This article reports on the Learning Exchange Programme (LEP) model of capacity building for Integrated Coastal Management (ICM) professionals. The LEP model of capacity building involves international group-based exchange visits during which a structured program of experiential learning events is undertaken to meet specific capacity gaps. An application of the LEP model in Japan and the United Kingdom is presented and evaluated, which shows that while refinements could be identified, a group-based, tailored exchange model focused on filling specific capacity gaps is an effective model of capacity building for ICM.     

Contribution of supposed wave condition on the long-term distribution of a wave-induced load

This report is concerned with the statistical analysis of the long-term distribution of a wave-induced load, and examines which factors influence the long-term distribution of the load level, e.g., the significant wave height, the mean wave period of the supposed wave condition, and the relative angle between the ship's course and the wave direction. The long-term distribution is broken down into these factors, and a contribution rate analysis method for each factor in each load level in the long-term distribution is introduced. Based on the method used, the contribution rate of a specific mean wave period and a wave angle encountered is clarified, when the long-term distribution is larger than other wave periods and wave angles. The specific mean wave period and wave angle encountered are defined as the wave condition which governs the long-term distribution. The maximum wave-induced load in the vicinity of a probability of exceedance of around 10⁻⁸ in the long-term distribution is decided by the most severe short-term wave condition which has the largest significant wave height with a specific mean wave period. Based on S–N curves and Miner's rule, the relation between the fatigue damage and the supposed wave condition is examined. The contribution rate analysis method for fatigue damage is introduced. The governing wave condition and the most severe short-term wave condition also have an important effect on the fatigue damage. A simple estimation method for the long-term distribution, described by the Weibull distribution from the statistical properties of the most severe short-term wave condition, is introduced. Several examples show the applicability of the estimation method. Received: November 22, 2001 / Accepted: January 9, 2002