The authors develop two-dimensional and three-dimensional simulation codes of the transient response of the temperature distribution in the lithium ion secondary battery during a discharge cycle. At ...first, a two-dimensional simulation code for a cylindrical battery is developed, and the simulation results for a commercially available small size battery are compared with the corresponding experimental results. The simulation results of the transient temperature and voltage variations coincide very well with the experimental results. The simulation result of the temperature difference between the center of the battery body and the center of the battery side is also in reasonable agreement with the experimental result. Next, the authors develop a three-dimensional simulation code and perform numerical simulations for three large size prismatic batteries with the same capacity and different cross sectional shapes. It is made clear that selecting the battery with the laminated cross section has a remarkable effect on the suppression of the temperature rise in comparison with the battery with square cross section, whereas the effect of the lamination on the suppression of the temperature unevenness is unexpectedly small. These results indicate the accuracy and usefulness of the developed simulation codes.
Tobacco is a valuable model system for investigating the origin of mitochondrial DNA (mtDNA) in amphidiploid plants and studying the genetic interaction between mitochondria and chloroplasts in the ...various functions of the plant cell. As a first step, we have determined the complete mtDNA sequence of Nicotiana tabacum. The mtDNA of N. tabacum can be assumed to be a master circle (MC) of 430,597 bp. Sequence comparison of a large number of clones revealed that there are four classes of boundaries derived from homologous recombination, which leads to a multipartite organization with two MCs and six subgenomic circles. The mtDNA of N. tabacum contains 36 protein-coding genes, three ribosomal RNA genes and 21 tRNA genes. Among the first class, we identified the genes rps1 and psirps14, which had previously been thought to be absent in tobacco mtDNA on the basis of Southern analysis. Tobacco mtDNA was compared with those of Arabidopsis thaliana, Beta vulgaris, Oryza sativa and Brassica napus. Since repeated sequences show no homology to each other among the five angiosperms, it can be supposed that these were independently acquired by each species during the evolution of angiosperms. The gene order and the sequences of intergenic spacers in mtDNA also differ widely among the five angiosperms, indicating multiple reorganizations of genome structure during the evolution of higher plants. Among the conserved genes, the same potential conserved nonanucleotide-motif-type promoter could only be postulated for rrn18-rrn5 in four of the dicotyledonous plants, suggesting that a coding sequence does not necessarily move with the promoter upon reorganization of the mitochondrial genome.
We describe observations carried out by the MOA group of the Galactic bulge during 2000 that were designed to detect efficiently gravitational microlensing of faint stars in which the magnification ...is high and/or of short duration. These events are particularly useful for studies of extrasolar planets and faint stars. Approximately 17 deg2 were monitored at a sampling rate of up to six times per night. The images were analysed in real time using a difference imaging technique. 20 microlensing candidates were detected, of which eight were alerted to the microlensing community whilst in progress. Approximately half of the candidates had high magnifications (≳10), at least one had very high magnification (≳50), and one exhibited a clear parallax effect. The details of these events are reported here, together with details of the on-line difference imaging technique. Some nova-like events were also observed and these are described, together with one asteroid.
In order to help a rapid development of Grid/Cloud aware applications, we have developed API to abstract the distributed computing infrastructures based on SAGA (A Simple API for Grid Applications). ...SAGA, which is standardized in the OGF (Open Grid Forum), defines API specifications to access distributed computing infrastructures, such as Grid, Cloud and local computing resources. The Universal Grid API (UGAPI), which is a set of command line interfaces (CLI) and APIs, aims to offer simpler API to combine several SAGA interfaces with richer functionalities. These CLIs of the UGAPI offer typical functionalities required by end users for job management and file access to the different distributed computing infrastructures as well as local computing resources. We have also built a web interface for the particle therapy simulation and demonstrated the large scale calculation using the different infrastructures at the same time. In this paper, we would like to present how the web interface based on UGAPI and SAGA achieve more efficient utilization of computing resources over the different infrastructures with technical details and practical experiences.
While Monte Carlo (MC) simulation is believed to be the most reliable method of dose calculation in particle therapy, the simulation time is critical in attaining sufficient statistical accuracy for ...clinical applications. Therefore, parallelization of simulations is essential. This paper describes a common platform of MC dose calculation in grid-distributed computing environments. The platform is flexible and effective for dose calculation in both clinical and research applications for particle therapy. The platform consists of the universal grid interface (UGI) and the Geant4-based particle therapy simulation framework (PTSIM). The UGI, written in Python, provides a command-line interface for job submission, file manipulation, and monitoring in multiple-grid middleware environments. The PTSIM is a single software application for modeling a treatment port with patient data obtained from CT images. The common platform was constructed in grid computing environments using the computing resources in five institutions. The platform utilized these resources through the NAREGI grid middleware under UGI to provide stable computing resources and a common environment for MC dose calculation in particle therapy.
A search for extrasolar planets was carried out in three gravitational microlensing events of high magnification, MACHO 98–BLG–35, MACHO 99–LMC–2 and OGLE 00–BUL–12. Photometry was derived from ...observational images by the MOA and OGLE groups using an image subtraction technique. For MACHO 98–BLG–35, additional photometry derived from the MPS and PLANET groups was included. Planetary modelling of the three events was carried out in a supercluster computing environment. The estimated probability for explaining the data on MACHO 98–BLG–35 without a planet is <1 per cent. The best planetary model has a planet of mass ~(0.4–1.5)×MEarth at a projected radius of either ~1.5 or ~2.3 au. We show how multiplanet models can be applied to the data. We calculate exclusion regions for the three events and find that Jupiter-mass planets can be excluded with projected radii from as wide as about 30 au to as close as around 0.5 au for MACHO 98–BLG–35 and OGLE 00–BUL–12. For MACHO 99–LMC–2, the exclusion region extends out to around 10 au and constitutes the first limit placed on a planetary companion to an extragalactic star. We derive a particularly high peak magnification of ~160 for OGLE 00–BUL–12. We discuss the detectability of planets with masses as low as Mercury in this and similar events.
Particle therapy system simulation framework, PTSIM, is a simulation framework based on Geant4 Monte Carlo simulation. It has been developed in the project, "Development of simulation framework for ...advanced radiotherapy", funded by the Japan Science and Technology Agency (JST) in the program of Core Research for Evolutional Research and Technology (CREST), from 2003 to 2010. The PTSIM has provided a common platform to model proton and ion therapy facilities, allowing users who are not Geant4 experts to accurately and efficiently run Geant4 simulations with the pre-build configurations. Efforts on further development of PTSIM are still under way to include more functionality and improve the performance. The PTSIM has been upgraded with the extensions in the DICOM-RT interface to coordinate with hospital information system, the Web interface with universal grid environment, etc. In this paper, we report on our activities about these updates and plan for extending the PTSIM functionality with new requirements from users.
The Belle II experiment is expected to produce 50 times more data than the existing Belle experiment. Such huge data production requires not only scalability with respect to the storage service but ...also scalability regarding the metadata service. There has already been a metadata service at the Belle experiment, but it is not proper for the Belle II experiment because it has scalability problems and it is not intended to be used in a distributed grid environment. To deal with these issues, we designed an advanced metadata service system based on AMGA, which provides efficient and scalable metadata searching. We have built testbed sites to test the correctness, performance and scalability of the advanced metadata service system, and it has been proved to be able to provide efficient metadata searching for the Belle II experiment. The Belle II experiment is expected to produce 50 times more data than the existing Belle experiment. Such huge data production requires not only scalability with respect to the storage service but also scalability regarding the metadata service. There has already been a metadata service at the Belle experiment, but it is not proper for the Belle II experiment because it has scalability problems and it is not intended to be used in a distributed grid environment. To deal with these issues, we designed an advanced metadata service system based on AMGA, which provides efficient and scalable metadata searching. We have built testbed sites to test the correctness, performance and scalability of the advanced metadata service system, and it has been proved to be able to provide efficient metadata searching for the Belle II experiment. KCI Citation Count: 2
In order to search for new physics beyond the standard model, the next generation of B-factory experiment, Belle II will collect a huge data sample that is a challenge for computing systems. The ...Belle II experiment, which should commence data collection in 2015, expects data rates 50 times greater than that of Belle. In order to handle this amount of data, we need a new data handling system based on a new computing model, which is a distributed computing model including grid farms as opposed to the central computing model using clusters at the Belle experiment. We have constructed a metadata system and embedded the system in the grid farms of the Belle II experiment. We have tested the system using grid farms. Results show good performance in handling such a huge amount of data. KCI Citation Count: 0
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