Detailed analysis of distraction induced by in-vehicle verbal interactions on visual search performance

We examined the negative effect of in-vehicle verbal interaction on visual search performance. Twenty participants performed a primary visual search task and a secondary verbal interaction task concurrently. We found that visual search performance deteriorated when the secondary task involving memory retrieval and speech production was performed concurrently. Moreover, a detailed analysis of the reaction time as a function of set size revealed that the increased reaction time was attributed not to the slowing of inspecting each item but to the increased processing time other than the inspection of each visual item, possibly due to task switching between the primary visual search task and the secondary verbal task. These findings have implications for providing information from in-vehicle information devices while reducing the risk of driver distraction.     

Erratum to: Development of a Theory of Constraints Based Scheduling System for Ship Piping Production

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A methodology to increase driver trust in rear-obstacle warning systems with imperfect sensing results — Proposal for a warning system using sensor reliability information

Driver's workload tends to be increased during driving under complicated traffic environments like lane-changing operation. In such cases, rear collision warning is effective for reduction of cognitive workload. On the other hand, it is pointed out that false alarm or missing alarm caused by sensor errors leads to decrease of driver trust in the warning system and it can result in low efficiency of the system. Suppose that sensor reliability information is provided in real-time. In this paper, we propose a novel warning method to increase driver trust in the system even with low sensor reliability by utilizing sensor reliability information. We investigate the effectiveness of the warning methods in high and low workload situations by driving simulator experiments.     

Fracture control of extremely thick welded steel plates applied to the deck structure of large container ships

The rapid enlargement of the size of container ships has led to the application of extremely thick plate in the deck structures, which may grow concerns about the fracture toughness at the butt-weld with large amount of heat input, and the arrest toughness of brittle crack propagation in the base metal of such thick plates. Also, slam-induced whipping stresses might affect the fatigue crack propagation and the initiation of a brittle crack in a container ship. In order to prevent the catastrophic failure of deck structures by brittle fracture, national joint research projects, which focused on the safety-related issues of extremely thick steel plate applied to hull of large container ships, were formed from April 2007 to March 2011 organized by the Japan Ship Technology Research Association (JSTRA) supported by the Japanese Government in collaboration with universities, national research institute, classification societies and relevant industries including shipbuilding, steel manufacturing and shipping companies. The joint research projects have carried out the investigations on crack initiation toughness of the weld, fatigue crack propagation under seaway loading, the potential of defect detection by ultrasonic testing, and the crack-arrest methods after brittle crack propagation. Practical recommendations to prevent brittle fracture of large container ships were proposed based on these comprehensive investigations. The essential parts of the above research activities are presented in this paper.     

Evaluation of Dynamic Soil-Structure Interaction and Dynamic Seismic Soil Pressures Acting on It Subjected to Strong Earthquake Motions

Introduction A detailed reconnaissance survey was conduct-ed at the underground structures such as subwaystructures, mountain tunnels, multipurpose under-ground ducts and other underground structures,around the Hanshin District caused by the 1995Hyogoken-Nanbu Earthquake[1,2]. Among thesestructures, the Daikai Subway Station is the firstsubway structure that completely collapsed due tothe earthquake[3]. In order to clarify the dynamicbehaviors and the damage mechanism of the DaikaiSubway S…     

High-resolution synthetic monitoring by a 4-dimensional variational data assimilation system in the northwestern North Pacific

A data assimilation system is applied to the integrated monitoring of oceanic states in the northwestern North Pacific by combining a high resolution ocean general circulation model with an adjoint method. A comparison of assimilation results with observations shows that the system is better able to represent synoptic features of ocean circulation than do models or data alone. Furthermore, meso-scale features associated with frontal structures and eddies, which are often seen in the Kuroshio and Oyashio extension regions and the Sea of Japan, are better defined in the assimilation results. These features suggest that our 4D-VAR high-resolution data assimilation system is capable of providing time series data which satisfy the model physics and fit the observations, and hence the ocean state derived from our system has greater information content than that obtained from earlier methods.     

Development of a theory of constraints based scheduling system for ship piping production

Manufacturing of ship piping system is one of the major production activities in shipbuilding. The schedule of pipe production has an important impact on master schedule of shipbuilding. In this research, the theory of constraints (TOC) concept is introduced to solve the scheduling problems of piping factory, and an intelligent scheduling system is developed. The system integrates a product model, an operation model, a factory model and a knowledge database of piping production and can make the process planning and production scheduling automatically. In the paper, details of above points are discussed. Moreover, an application of the system in a piping factory, which achieves a higher level of performance as measured by tardiness, lead time and inventory, is demonstrated at the end of the paper.     

止裂韧度值Kca的实尺模型试验研究

对船用钢进行长裂纹止裂特性研究表明:它们的脆性裂纹止裂能力不够。TMCP钢有足够的脆性裂纹止裂能力。对船用钢进行了两种实尺(actual-scale)模型试验,明确了脆性裂纹扩展的条件。根据试验结果提出了止裂韧度值Kca,已经归纳在"脆性裂纹止裂设计指导性文件"中。