Japan Automobile Research Institute

Ibaraki, Japan

Japan Automobile Research Institute

Ibaraki, Japan
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Kurokawa J.,Asia Center for Air Pollution Research | Kurokawa J.,Japan National Institute of Environmental Studies | Ohara T.,Japan National Institute of Environmental Studies | Morikawa T.,Japan Automobile Research Institute | And 6 more authors.
Atmospheric Chemistry and Physics | Year: 2013

We have updated the Regional Emission inventory in ASia (REAS) as version 2.1. REAS 2.1 includes most major air pollutants and greenhouse gases from each year during 2000 and 2008 and following areas of Asia: East, Southeast, South, and Central Asia and the Asian part of Russia. Emissions are estimated for each country and region using updated activity data and parameters. Monthly gridded data with a 0.25 × 0.25 resolution are also provided. Asian emissions for each species in 2008 are as follows (with their growth rate from 2000 to 2008): 56.9 Tg (+34%) for SO2, 53.9 Tg (+54%) for NOx, 359.5 Tg (+34%) for CO, 68.5 Tg (+46%) for non-methane volatile organic compounds, 32.8 Tg (+17%) for NH3, 36.4 Tg (+45%) for PM10, 24.7 Tg (+42%) for PM 2.5, 3.03 Tg (+35%) for black carbon, 7.72 Tg (+21%) for organic carbon, 182.2 Tg (+32%) for CH4, 5.80 Tg (+18%) for N2O, and 16.0 Pg (+57%) for CO2. By country, China and India were respectively the largest and second largest contributors to Asian emissions. Both countries also had higher growth rates in emissions than others because of their continuous increases in energy consumption, industrial activities, and infrastructure development. In China, emission mitigation measures have been implemented gradually. Emissions of SO2 in China increased from 2000 to 2006 and then began to decrease as flue-gas desulphurization was installed to large power plants. On the other hand, emissions of air pollutants in total East Asia except for China decreased from 2000 to 2008 owing to lower economic growth rates and more effective emission regulations in Japan, South Korea, and Taiwan. Emissions from other regions generally increased from 2000 to 2008, although their relative shares of total Asian emissions are smaller than those of China and India. Tables of annual emissions by country and region broken down by sub-sector and fuel type, and monthly gridded emission data with a resolution of 0.25 × 0.25 for the major sectors are available from the following URL: http://www.nies.go.jp/REAS/. © 2013 Author(s).

Ito D.,Japan Automobile Research Institute | Tanaka E.,Nagoya University | Yamamoto S.,Shibaura Institute of Technology
Journal of the Mechanical Behavior of Biomedical Materials | Year: 2010

The purpose of this study is to develop a constitutive model of skeletal muscle that describes material anisotropy, viscoelasticity and damage of muscle tissue. A free energy function is described as the sum of volumetric elastic, isochoric elastic and isochoric viscoelastic parts. The isochoric elastic part is divided into two types of shear response and the response in the fiber direction. To represent the dependence of the mechanical properties on muscle activity, we incorporate a contractile element into the model. The viscoelasticity of muscle is modeled as a three-dimensional model constructed by extending the one-dimensional generalized Maxwell model. Based on the framework of continuum damage mechanics, the anisotropic damage of muscle tissue is expressed by a second-order damage tensor. The evolution of the damage is assumed to depend on the current strain and damage. The evolution equation is formulated using the representation theorem of tensor functions. The proposed model is applied to the experimental data on tensile mechanical properties in the fiber direction and the compression properties in the fiber and cross-fiber directions in literature. The model can predict non-linear mechanical properties and breaking points. © 2009 Elsevier Ltd. All rights reserved.

Torii R.,Imperial College London | Oshima M.,University of Tokyo | Kobayashi T.,Japan Automobile Research Institute | Takagi K.,University of Tokyo | And 2 more authors.
Computational Mechanics | Year: 2010

Patient-specific simulations based on medical images such as CT and MRI offer information on the hemodynamic and wall tissue stress in patient-specific aneurysm configurations. These are considered important in predicting the rupture risk for individual aneurysms but are not possible to measure directly. In this paper, fluid-structure interaction (FSI) analyses of a cerebral aneurysm at the middle cerebral artery (MCA) bifurcation are presented. A 0D structural recursive tree model of the peripheral vasculature is incorporated and its impedance is coupled with the 3D FSI model to compute the outflow through the two branches accurately. The results are compared with FSI simulation with prescribed pressure variation at the outlets. The comparison shows that the pressure at the two outlets are nearly identical even with the peripheral vasculature model and the flow division to the two branches is nearly the same as what we see in the simulation without the peripheral vasculature model. This suggests that the role of the peripheral vasculature in FSI modeling of the MCA aneurysm is not significant. © 2009 Springer-Verlag.

Yokoya Y.,Japan Automobile Research Institute
Physica D: Nonlinear Phenomena | Year: 2010

We studied the nature of fluctuations around the phase transition of vehicular traffic by analyzing a time series of successive variations of velocity, obtained from single-vehicle data measured by an onboard apparatus. We found that the probability density function calculated from the time series of variation of velocity is transformed irreversibly in the critical region, where a Gaussian distribution changes into a Lévy stable symmetrical distribution. The power-law tail in the Lévy distribution indicated that the time series of velocity variation exhibits the nature of the critical fluctuations generally observed in phase transitions driven far from equilibrium. Furthermore, single-vehicle data enabled us to calculate the time evolution of the local flux-density relation, which suggested that the vehicular traffic system spontaneously approaches a delicate balance between metastable states and congested-flow states. The nature of fluctuations enables us to understand mechanisms behind the spontaneous decay of the metastable branch at the phase transition. The power-law tail in the probability density function suggests that dynamical processes of vehicular traffic in the critical region are related to a time-discrete stochastic process driven by random amplification with additive external noise. © 2009 Elsevier B.V. All rights reserved.

Kitamura T.,Japan Automobile Research Institute | Ito T.,Japan Automobile Research Institute
SAE International Journal of Engines | Year: 2010

This paper proposes a new mixing-controlled, low temperature combustion (LTC) approach for high-speed direct injection (HSDI) diesel engines. The purpose of this approach is to avoid the excessively high pressure-rise rate (PRR) of premixed, kinetics-controlled LTC and to enable the low nitrogen oxides (NOx) combustion to operate over the wide speed and load range of the engine. To address the soot/noise trade-off at high load LTC operating conditions, the pressure modulated multiple-injection coupled with swirl control was applied. This injection strategy enables the injection of high pressure (HP) main spray into the local high temperature region of the already burning low pressure (LP) pilot spray injected from the neighboring injection hole. By employing this injection strategy, the equivalence ratio (φ) distribution of mixture is drastically varied during main combustion processes. The experimental results showed that by combining LP close-pilot injection, HP main injection near top dead center (TDC), and moderate swirl, the mixing-controlled LTC successfully achieve low engine-out NOx and soot emissions even at 13.7 bar IMEP while retaining high efficiency and low PRR. Furthermore, the 3D-CFD analysis clarified that the rich mixture of broadband φ distribution is formed at the beginning of main combustion followed by rapid homogenization of the mixture occurring as combustion progresses. © 2010 SAE International.

Hashimasa Y.,Japan Automobile Research Institute | Numata T.,Japan Automobile Research Institute | Yoshimura N.,Japan Automobile Research Institute
Journal of Power Sources | Year: 2014

Structural changes in a polymer electrolyte membrane (PEM) and a membrane electrode assembly (MEA) of different catalyst thickness under humidity cycle tests were investigated. Nafion211 membrane was used in this study. The catalyst layer thickness of MEAs was set to 2-10 μm using catalyst paste of the same composition. Dimensional changes in the PEM and MEA due to swelling were measured, and dynamic mechanical analysis (DMA) of the membrane and MEA were carried out. Moreover, humidity cycle tests for the MEA were carried out according to the conditions specified in the FCCJ protocol, and structural changes in the MEA after the tests were examined. It was shown that the membranous structural change under humidity cycle tests tends to become small when the thickness of the catalyst layer is large. © 2014 Elsevier B.V. All rights reserved.

Kanari S.,Japan Automobile Research Institute
Lecture Notes in Electrical Engineering | Year: 2013

The authors developed long-term scenarios for reducing CO2 emissions by using CEAMAT. CEAMAT is an energy analysis model for considering long-term effects of future automotive technologies in the Japanese automotive sector. At first, future automotive data and demand of the automotive sector of the IEEJ2050 model were entered into CEAMAT, then open literature was reviewed, and interviews were conducted with relevant organizations. Secondly, the authors developed long-term scenarios for the Japanese automotive sector using CEAMAT. According to these scenarios, by the year 2050 the share of next-generation vehicles in use will increase by 43 % for passenger cars and 48 % for medium-sized and large trucks, and CO2 emissions will be reduced by 47 % compared to the year 2005. Finally, calculations were made of the potential for integrated approaches of eco-driving and improving traffic flow to reduce CO2 emissions. CEAMAT indicated that the integrated approaches could help reduce CO2 emissions by 55 % compared to the year 2005. © 2013 Springer-Verlag.

Abe G.,Japan Automobile Research Institute
Nihon Kikai Gakkai Ronbunshu, C Hen/Transactions of the Japan Society of Mechanical Engineers, Part C | Year: 2010

In order to investigate effects of driving conditions and traffic environments on visual behaviour, a driving simulator experiment was conducted. Specifically it was considered how a visual field was influenced as a function of cognitive distraction, possibly resulting in a situation of look-but-did-not see, and crowdedness of other vehicles and pedestrians. Cognitive distraction was simulated by a experimental secondary task which was relevant to mental calculations. It was found that driver's reaction time to a target mark was increased resulting from cognitive distraction. This result may be explained from a driver's visual field point of view. That is a visual field for recognising a target mark got small when drivers was distracted with particularly driving on non-crowded road, compared with crowded road. Potential application of this research will be discussed.

Japan Automobile Research Institute and HORIBA Ltd. | Date: 2012-09-05

This invention intends to provide a vehicle-mounted driving recorder (1) that can facilitate an after-the-fact analysis on not only situation data at a time of an accident but also situation data at a time of a hiyari hatto (risk incident) and that can contribute accident prevention. The vehicle-mounted driving recorder (1) comprises a data receiving section that receives situation data indicating behavior, a surrounding situation, and an operating situation of a vehicle and a data administration section (804) that classifies the situation data into one of predetermined multiple categories based on contents of the received situation data and stores the classified situation data in a situation data storage section (803) specified in a predetermined area of a memory.

Japan Automobile Research Institute | Date: 2013-10-29

A risky situation is reproduced in a direct visual field of a driver driving a vehicle with a high sense of reality. A vehicle position and attitude calculation unit calculates a present position and a traveling direction of the vehicle, a driving action detector detects an action performed by the driver driving the vehicle and the condition of the vehicle, a scenario generator generates a content, position, and timing of the risky situation occurring while the driver drives the vehicle, a virtual information generator generates visual virtual information indicating the risky situation, and a superimposing unit superimposes the generated virtual information on the image of the traveling direction of the vehicle shot by an imaging unit Then, an image display unit indicates the image on which the virtual information is superimposed in the direct visual field of the driver.

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