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Hazama, Osamu; Nakajima, Norihiro; Post, P.*; Wolf, K.*
Proceedings of 8th US National Congress on Computational Mechanics (USNCCM-8) (CD-ROM), 1 Pages, 2005/07
Computational science has always played an import role in nuclear engineering because it is quite difficult, if not impossible, to carry out experiments on the actual full-scale reactors in operation. We have been developing a numerical simulation infrastructure for carrying out numerical experiments on the virtual reactors constructed within computers. In order to understand the physical behavior of a reactor, interactions among various physial phenomena must be considered and understood. Therefore, a generic coupler has been developed to connect various software and hardware for the purposes of coupled simulations. Since this type of simulation requires large amount of computational resources, the coupler development is carried out on the ITBL GRID infrastructure. The development of this coupler and its applications to parallel and distributed coupled simulations with future development plans are reported.
Hazama, Osamu; Nakajima, Norihiro
Keisan Kogaku Koenkai Rombunshu, 10(1), p.259 - 260, 2005/05
It is impossible to carry out a controlled laboratory experiments on an operational full-scale power plant. Therefore, construction of a testbed to assess the safety of such systems by numerical means is believed to be meaningful. At CCSE/JAERI, a project to develop a numerical testbed to assess the safety of nuclear reactors have been begun. Simulations of such complex systems will inevitably require tremendous amount of computational resources. Therefore, the numerical testbed is constructed on the ITBL Grid middleware. A prototype of a generic software coupling interface was developed to couple various simulation software within the ITBL Grid environment to execute large-scale multi-disciplinary simulations on the testbed. This coupler and its application to some fluid-structure problems will be illustrated.
Hazama, Osamu; Nakajima, Norihiro
Proceedings of 6th MpCCI User Forum, p.76 - 77, 2005/05
In order to accurately solve complex physical phenomena, interactions of various phenomena must be considered, which makes simulations multi-disciplinary. We have been developing a virtual nuclear reactor simulator on the ITBL Grid infrastructure in order to assess the safety of the nuclear reactors. This simulator system allows for numerical experiments on the full-scale and fully operational virtual nuclear reactors which is not possible in real-life experiments. In order to clarify various complex physical phenomena within the reactors, multi-disciplinary simulations, which are computationally demanding, are required. We have been developing a software to allow concurrent use of arbitrary combination of hardware and software to realize a multi-disciplinary simulation system on the ITBL. We have used STAMPI, developed by CCSE/JAERI, and MpCCI, developed by Fraunhofer SCAI, to construct the system. The system is now functional on the ITBL and will be introduced.
Hazama, Osamu; Guo, Z.*
Keisan Kogaku Koenkai Rombunshu, 9(2), p.617 - 620, 2004/05
Although multi-disciplinary coupled simulations are considered important and necessary by many to reflect reality into the numerical simulations, there still exist many obstacles which inhibit such numerical simulations. There still exist very few software packages in the market which satisfy user needs in such numerical simulations. In many instances, self-development of software packages which allow for such coupled simulations will also be quite burdensome simply because considering multi-physics require more knowledge, experience, time 
. Parallel processing of the simulations will definitely be required to aquire meaningful coupled solutions within a given practical time. Under the international collaborative efforts between CCSE/JAERI and Fraunhofer SCAI, a generic code coupling mechanism and implementation are developed for multi-disciplinary simulation of continua in a meta-computing environment. Two libraries, STAMPI, by CCSE/JAERI, and MpCCI, by Fraunhofer SCAI, will be implemented together to allow such simulations.
Nagai, Haruyasu
JAERI-Data/Code 2003-021, 36 Pages, 2003/12
JAERI-Data-Code-2003-021.pdf:1.73MB
A new method to couple atmosphere and land-surface models using the massage passing interface (MPI) was proposed to develop a atmosphere-land model for studies on heat, water, and material exchanges at around the land surface. A non-hydrostatic atmospheric dynamic model of Pennsylvania State University and National Center for Atmospheric Research (PUS/NCAR-MM5) and a detailed land surface model (SOLVEG) including the surface-layer atmosphere, soil, and vegetation developed at Japan Atomic Energy Research Institute (JAERI) are used as the atmosphere and land-surface models, respectively. Concerning the MPI, a message passing library named Stampi developed at JAERI that can be used between different parallel computers is used. The models are coupled by exchanging calculation results by using MPI on their independent parallel calculations.
Hazama, Osamu; Guo, Z.
Proceedings of International Conference on Supercomputing in Nuclear Applications (SNA 2003) (CD-ROM), p.119 - 120, 2003/09
In order for the numerical simulations to reflect textquotedblleft real-worldtextquotedblright phenomena and occurrences, incorporation of multidisciplinary and multi-physics simulations considering various physical models and factors are becoming essential. However, there still exist many obstacles which inhibit such numerical simulations. For example, it is still difficult in many instances to develop satisfactory software packages which allow for such coupled simulations and such simulations will require more computational resources. A precise multi-physics simulation today will require parallel processing which again makes it a complicated process. Under the international cooperative efforts between CCSE/JAERI and Fraunhofer SCAI, a German institute, a library called the MpCCI, or Mesh-based Parallel Code Coupling Interface, has been implemented together with a library called STAMPI to couple two existing codes to develop an textquotedblleft integrated numerical simulation systemtextquotedblright intended for meta-computing environments.
Guo, Z.; Hazama, Osamu; Yamagiwa, Mitsuru; Hirayama, Toshio; Matsuzawa, Teruo*
Advances in computational & experimental engineering & sciences (CD-ROM), 6 Pages, 2003/07
no abstracts in English
Hazama, Osamu; Guo, Z.
Keisan Kogaku Koenkai Rombunshu, 8(2), p.759 - 760, 2003/05
no abstracts in English
Tsujita, Yuichi; Yamagishi, Nobuhiro*; Kimura, Kazuyuki*; Otani, Takayuki; Tsuruoka, Nobuhiko*; Fujita, Naoyuki*
Joho Shori Gakkai Kenkyu Hokoku 2002-HPC-92, p.7 - 12, 2002/10
SCore system has been developed to provide flat computing infrastructure for parallel computing without awareness of each compute host in a PC cluster system. An SCore cluster system can be handled as a single computer. MPICH-SCore, which is an MPI library in SCore, is not available across multiple SCore cluster systems as well as multiple platforms. We have implemented an MPI communication library, Stampi in SCore cluster system to enable MPI communication between SCore cluster systems and measured communication performance of the library using SCore cluster systems.
Tsujita, Yuichi; Imamura, Toshiyuki; Takemiya, Hiroshi*; Yamagishi, Nobuhiro*
Keisan Kogaku Koenkai Rombunshu, 7(1), p.159 - 162, 2002/05
no abstracts in English
Tsujita, Yuichi; Imamura, Toshiyuki; Takemiya, Hiroshi*; Yamagishi, Nobuhiro*
Recent Advances in Parallel Virtual Machine and Message Passing Interface, p.288 - 295, 2002/00
An MPI-2 based parallel-I/O library, Stampi-I/O, has been developed using flexible communication infrastructure. In Stampi-I/O almost all MPI-I/O functions have been implemented. We can execute these functions using both local and remote I/O operations with the same application program interface (API) based on MPI-2. In I/O operations using Stampi-I/O, users need not handle any differences in the communication mechanism of computers. We have evaluated performance for primitive functions in Stampi-I/O. Through this test, sufficient performance has been achieved and effectiveness of our flexible implementation has been confirmed.
Tsujita, Yuichi; Imamura, Toshiyuki; Takemiya, Hiroshi*; Yamagishi, Nobuhiro*
Proceedings of 5th World Multiconference on Systemics, Cybernetics and Informatics (SCI 2001), p.402 - 407, 2001/07
An MPI-2 based distributed parallel-I/O library called Stampi-I/O has been developed using communication infrastructure of Stampi. Stampi is a communication library based on MPI and MPI-2. It has been developed for heterogeneous computing environment as infrastructure of metacomputing. As many applications in computational science handle huge amount of data which one parallel computer can not handle, distributed parallel-I/O libraries have been required for effective handling of such huge data on heterogeneous computing environment. Considering this situation, Stampi-I/O has been designed and developed. In this paper, motivations, architecture and preliminary results of performance measurement of Stampi-I/O are described.
Mochizuki, Yuji*; Koide, Hiroshi; Imamura, Toshiyuki; Takemiya, Hiroshi*
Journal of Synchrotron Radiation, 8(Part.2), p.1003 - 1005, 2001/03
no abstracts in English
Tsujita, Yuichi; Imamura, Toshiyuki; Takemiya, Hiroshi*; Yamagishi, Nobuhiro*
Joho Shori Gakkai Kenkyu Hokoku 2000-HPC-84, p.43 - 48, 2000/12
no abstracts in English
Furuno, Akiko; Yamazawa, Hiromi; Lee, S.; Tsujita, Yuichi; Takemiya, Hiroshi*; Chino, Masamichi
Proceedings of 4th International Conference on Supercomputing in Nuclear Applications (SNA 2000) (CD-ROM), 7 Pages, 2000/09
no abstracts in English
Lee, S.; Chino, Masamichi
Proceedings of 4th International Conference on Supercomputing in Nuclear Applications (SNA 2000) (CD-ROM), 9 Pages, 2000/09
no abstracts in English
Lee, S.; Chino, Masamichi
Keisan Kogaku Koenkai Rombunshu, 5(1), p.373 - 376, 2000/05
no abstracts in English
Imamura, Toshiyuki; Koide, Hiroshi; Tokuda, Shinji; Takemiya, Hiroshi
Keisan Kogaku Koenkai Rombunshu, 4(1), p.313 - 316, 1999/05
no abstracts in English
; Hirayama, Toshio; *; Hayashi, Takuya*; Kasahara, Hironori*
Int. Conf. on Supercomputing,Workshop 1;Scheduling Algorithms for Parallel-Distributed Computing, p.63 - 69, 1999/00
no abstracts in English
; Imamura, Toshiyuki; *; *; Takemiya, Hiroshi*; Higuchi, Kenji; Kasahara, Hironori*;
Keisan Kogaku Koenkai Rombunshu, 3(1), p.81 - 84, 1998/05
no abstracts in English