22 research outputs found

    Energy Aware Scheduler of Single/Multi-Node Jobs Considering CPU Node Heterogeneity

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    2022 IEEE 13th International Green and Sustainable Computing Conference (IGSC), 24-25 October 2022, Pittsburgh, PA, USAModern CPUs suffer from power efficiency heterogeneity, which can result in additional energy cost or performance loss. On the other hand, future supercomputers are expected to be power constrained. This paper focuses on energy aware scheduling algorithms targeted on two situations considering this node heterogeneity. In single-node situation, workload consists of various single-node jobs, Combinatorial Optimization Algorithm saves energy by calculating a local optimal power efficiency node allocation plan from KM (Kuhn-Munkres) algorithm. In multi-node situation, power cap causes load unbalancing in multi-node jobs due to the node heterogeneity. Sliding Window Algorithm targets on reducing such unbalancing by sliding window. Proposed algorithms are evaluated in the simulation and real supercomputer environment. In single-node situation, Combinatorial Optimization Algorithm achieved up to 2.92% saving. For the multi-node situation, workload is designed based on real historic workload, and up to 5.36% saving was achieved by Sliding Window Algorithm

    Validity of reduced radiation dose for localized diffuse large B-cell lymphoma showing a good response to chemotherapy

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    To evaluate the validity of a decrease in the radiation dose for patients who were good responders to chemotherapy for localized diffuse large B-cell lymphoma (DLBCL), 91 patients with localized DLBCL who underwent radiotherapy after multi-agent chemotherapy from 1988-2008 were reviewed. Exclusion criteria were as follows: central nervous system or nasal cavity primary site, or Stage II with bulky tumor (>= 10 cm). Of these patients, 62 were identified as good responders to chemotherapy. They were divided into two groups receiving either a higher or a lower radiation dose (32-50.4 Gy or 15-30.6 Gy, respectively). There were no statistically significant differences between the lower and higher dose groups in progression-free survival, locoregional progression-free survival or overall survival. Adaptation of decreased radiation dose may be valid for localized DLBCL patients who show a good response to chemotherapy.ArticleJOURNAL OF RADIATION RESEARCH. 55(2):359-363 (2014)journal articl

    Impact of upgraded radiotherapy system on outcomes in postoperative head and neck squamous cell carcinoma patients

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    Background: This study was performed to evaluate the impact of upgrade of radiotherapy system, including launch of intensity-modulated radiation therapy (IMRT), on the therapeutic outcomes. Materials and methods: Patients with head and neck (H&N) squamous cell carcinoma (SCC) who underwent postoperative radiotherapy at our hospital between June 2009 and July 2019 were retrospectively reviewed. In July 2014, we converted the radiotherapy technique for these patients from a 3-dimensional conformal radiotherapy (3D-CRT) to IMRT, along with the adoption of a meticulous planning policy and a few advanced procedures, including online imaging guidance. Results: A total of 136 patients (57 treated with the previous system and 79 treated with the upgraded system) were reviewed. There were significantly more patients with extracapsular extension in the upgraded-system group than the previous-system group (p = 0.0021). There were significantly fewer patients with ≥ Grade 2 acute and late adverse events in the upgraded-system group than the previous-system group. The differences in progression-free survival (PFS), distant metastasis-free survival (DFFS), locoregional progression-free survival (LRPFS), and overall survival (OS) between the two groups were not statistically significant (p = 0.8962, 0.9926, 0.6244, and 0.4827, respectively). Multivariate analysis revealed that the upgrade had neither positive nor negative impact on survival outcomes. Extracapsular extension was independently associated with decreased LRPFS and OS (p = 0.0499 and 0.0392, respectively). Conclusions: The IMRT-centered upgrade was beneficial for the postoperative patients with H&N SCC, because survival outcomes were sustained with less toxicities.

    A high-resolution global Vlasov simulation of a small dielectric body with a weak intrinsic magnetic field on the K computer

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    The interaction between the solar wind and solar system bodies, such as planets, satellites, and asteroids, is one of the fundamental global-scale phenomena in space plasma physics. In the present study, the electromagnetic environment around a small dielectric body with a weak intrinsic magnetic field is studied by means of a first-principle kinetic plasma simulation, which is a challenging task in space plasma physics as well as high-performance computing. Due to several computational limitations, five-dimensional full electromagnetic Vlasov simulations with two configuration space and three velocity space coordinates are performed with two different spatial resolutions. The Debye-scale charge separation is not solved correctly in the simulation run with a low spatial resolution, while all the physical processes in collisionless plasma are included in the simulation run with a high spatial resolution. The direction comparison of electromagnetic fields between the two runs shows that there is small difference in the structure of magnetic field lines. On the other hand, small-scale fine structures of electrostatic fields are enhanced by the electric charge separation and the charge accumulation on the surface of the body in the high-resolution run, while these structures are absent in the low-resolution runs. These results are consistent with the conventional understanding of plasma physics that the structure and dynamics of global magnetic fields, which are generally described by the magneto-hydro-dynamics (MHD) equations, are not affected by electron-scale microphysics

    Acceleration of PIC Simulation with GPU * )

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    Particle-in-cell (PIC) is a simulation technique for plasma physics. The large number of particles in highresolution plasma simulation increases the volume computation required, making it vital to increase computation speed. In this study, we attempt to accelerate computation speed on graphics processing units (GPUs) using KEMPO, a PIC simulation code package [H. Matsumoto and Y. Omura, Computer Space Plasma Physics, pp.21-65 (1985)]. We perform two tests for benchmarking, with small and large grid sizes. In these tests, we run KEMPO1 code using a CPU only, both a CPU and a GPU, and a GPU only. The results showed that performance using only a GPU was twice that of using a CPU alone. While, execution time for using both a CPU and GPU is comparable to the tests with a CPU alone, because of the significant bottleneck in communication between the CPU and GPU
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