Analysis of social networks,social interactions,and out-of-home leisure activity generation: Evidence from Japan

Transportation - This article analyses the connection between social networks, social interactions and out-of-home leisure activity generation in the context of Japanese society. A multilevel...     

制动系统的技术课题与发展动向

介绍了日本制动系统的技术发展现状、主要成果,以及待解决的课题,展望了将来的技术动向,也对合成闸瓦及新一代制动技术的开发动向进行了阐述。     

Adaptive Yaw Rate Feedback 4WS with Tire/Road Friction Coefficient Estimator

This paper proposes an adaptive yaw rate feedback control system for a four-wheel-steering (4WS) vehicle which involves a tire/road friction coefficient estimator. The adaptive 4WS system has been developed so that the vehicle possesses desirable lateral characteristics even on slippery roads and in critical driving situations. The friction coefficient is estimated on real time from the yaw rate response of the controlled vehicle with the least squares. The control system adopts a two degree of freedom structure which consists of a feedforward compensator and a feedback control subsystem. The feedforward compensator is determined with the estimated friction coefficient to minimize the steady-state and transient vehicle slip angle in spite of changes in tire/road conditions. The feedback subsystem adopts the Internal Model Control (IMC) structure in order to compensate for nonlinearities and to realize robustness against modelling and estimation errors.     

Time-domain strip method with memory-effect function considering the body nonlinearity of ships in large waves

A time-domain strip method with memory-effect function considering body nonlinearity is presented. In small waves, results from conventional linear strip theory and the present method for a modified Wigley model were compared with the results of linear theories and with experiments, and they were found to be in good agreement. In large waves, a 716 TEU containership was used to compare time histories of motions and vertical bending moments calculated using the present method with experimental results. The time histories of motion were not strongly distorted, but those of the vertical bending moments were extremely distorted, especially for the fore part, and were far from sinusoidal signals. The time histories of the calculations and the experimental results were found to be, qualitatively and quantitatively, in good agreement. A post-Panamax containership was also used as an example of an up-to-date large bow-flare ship, and the calculated results were also found to be in good agreement with the experimental results.     

Study of fatigue crack nucleation processes by crystalline FE analysis

 In order to accumulate knowledge about how material compositions and manufacturing methods affect fatigue strength, this paper investigates the relationship between the swiftness of the changes in the macroscopic indices of the crack initiation process and the hardening properties of a material. This is done by calculating the cyclic deformation behavior of a f.c.c. single crystal. The relationship between the swiftness of the changes and the crystal geometries is also examined by calculating the deformation behavior of a f.c.c. crystal with a high Schmid factor buried in a large crystal with a low Schmid factor. In addition, a multiscale hardening rule based on forest theory is developed in order to examine the microscopic mechanisms of fatigue slip band (persistent slip bands, PSBs) formation. The validity of the theories presented is examined by comparing the changing nature of the measured and calculated hysteresis loop shapes of f.c.c. single crystals. Inhomogenous slip deformation through the crystal is also investigated, and inferences are then drawn about the microscopic mechanisms of cyclic hardening and PSB formation. Received: August 5, 2002 / Accepted: December 18, 2002 Address correspondence to: N. Osawa (osawa@naoe.eng.osaka-u.ac.jp) Updated from the Japanese original, which won the 2002 SNAJ prize (J Soc Nav Archit Jpn 1998;184:351–363, 1999;185:283–292 and 186:535–544, 2001;190:539–551)     

Egocentric social networks and social interactions in the Greater Tokyo Area

Transportation - This article presents the results of a survey on egocentric social networks in the Greater Tokyo Area. This is, together with our preliminary study, the first study on egocentric...     

The Trends and Tasks of Modeling and Simulation for Reduction of Heat Treatment Distortion

IntroductionTherearemanyfacorswhichinfluencethedistortonofworkpieceandeveryheattreatInentengineerssWandtrytofindordevelopmodelsandsimulationmethodstoestimateandreducedistortonorwarpage.VariousmodelshavebeenandbeinginvestigatOdtoestimatetheinduenceoffacorsontfansformahonkinetics,hardness,residualstressanddistOrtionarerCPortCdatmanyconferences,.HowevefHEARTS[l]andafewofothermodelshavebeendeveloPedandcontrthutingtounderstandandPredicttheialluenceofrelatngfacors[2-1o].EVenstillmanyhazardous…