PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 8028959

[Parallel processing of dose calculation for external photon beam therapy].

E Kunieda·Y Ando·N Tsukamoto·H Ito·A Kubo
View original source ↗Export metadata ↓

Abstract

We implemented external photon beam dose calculation programs into a parallel processor system consisting of Transputers, 32-bit processors especially suitable for multi-processor configuration. Two network conformations, binary-tree and pipeline, were evaluated for rectangular and irregular field dose calculation algorithms. Although computation speed increased in proportion to the number of CPU, substantial overhead caused by inter-processor communication occurred when a smaller computation load was delivered to each processor. On the other hand, for irregular field calculation, which requires more computation capability for each calculation point, the communication overhead was still less even when more than 50 processors were involved. Real-time responses could be expected for more complex algorithms by increasing the number of processors.

Explore related subjects

Mathematical ComputingModels, StructuralPhotonsRadiotherapy Planning, Computer-AssistedSoftwareEnglish AbstractJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

E Kunieda, Y Ando, N Tsukamoto, H Ito, A Kubo. 1994-05-25. [Parallel processing of dose calculation for external photon beam therapy].. https://pubmed.ncbi.nlm.nih.gov/8028959/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2006

Exactly solvable models of adaptive networks.

A satisfiability-unsatisfiability (SAT-UNSAT) transition takes place for many optimization problems when the number of constraints, graphically represented by links between variables nodes, is brought above some threshold. If the network of constraints is allowed to adapt by redistributing its links, the SAT-UNSAT transition may be delayed and preceded by an intermediate phase where the structure self-organizes to satisfy the constraints. We present an analytic approach, based on the recently introduced cavity method for large deviations, which exactly describes the two phase transitions delimiting this adaptive intermediate phase. We give explicit results for random bond models subject to the connectivity or rigidity percolation transitions, and compare them with numerical simulations.

Mathematical Computing↗
PubMed2006

Surface-enhanced Raman spectroscopy and density functional theory study on 4,4'-bipyridine molecule.

The molecular geometry and vibrational frequencies of 4,4'-bipyridine (BPE) in the ground state were calculated using density functional theory (DFT) methods (B3LYP) with 6-31++G(d,p) basis set. The optimized geometric bond lengths and bond angles are obtained by DFT employing the hybrid of Beckes non-local three parameter exchange and correlation functional and Lee-Yang-Parr correlation functional. Fourier transform infrared (FT-IR), Fourier transform Raman (FT-Raman) and near-infrared surface-enhanced Raman scattering (NIR-SERS) spectra of BPE on the silver foil substrate have been recorded. All FT-IR, FT-Raman and NIR-SERS band were assigned on the basis of the B3LYP/6-31++G(d,p) method. The vibrational frequencies obtained by DFT(3LYP) are in good agreement with observed results. The NIR-SERS of BPE excited by 1064nm laser line is little difference with that excited by visible laser line. This phenomenon is result to the increase of the contribution of CHEM enhancement effect. Surface selection rules derived from the electromagnetic enhancement model were employed to infer the orientations of BPE on the silver foil substrate surface. Some vibrational frequency which are sensitive to the planar or non-planar structure of BPE, and to the dihedral angle were concluded.

Mathematical Computing↗