Monte Carlo simulation on a system of hard cylinders at a very high packing fraction

ABSTRACTThe inherent complexity of defect processes in III-V's and the consequent difficulties with ab initio and semi-empirical methods are recalled. A potential solution using massive Monte Carlo simulation on microcomputers is suggested. Evidence for the validity of the Ballistic Model, BM, of atomic diffusion in III-V's is noted. According to the BM the effect of strain (in the absence of any electrostatic, population, or recombination effect) is to increase the rate at which a given mobile atom hops where the sample is compressed. For the case of misfit strain at a (100) junction, we note that the anisotropy of the elastic constants implies that some planes running into the bulk will be compressed whichever the sign of the misfit. This implies that misfit strain of either sign should increase the observed rate of interdiffusion, in the absence of other effects. We also recall the importance (demonstrated at low T) of recombination enhancement of atomic diffusion, RED. Devices are processed at temperatures where the thermal rate of recombination is very high and often operated at high levels of injection. The interaction of strain with RED is clearly important and complicated. III-V crystals have the further complication of being piezoelectric. The active piezoelectric axes are <111>, so a pure <100> strain does not produce a field. However, the accommodation a device makes to misfit at (100) junctions can generate a strong field, which may fluctuate with bias voltage.

Download Full-text

A very high speed Monte Carlo simulation on DAP

Computer Physics Communications ◽

10.1016/0010-4655(85)90172-9 ◽

1985 ◽

Vol 37 (1-3) ◽

pp. 351-356 ◽

Cited By ~ 24

Author(s):

S.F. Reddaway ◽

D.M. Scott ◽

K.A. Smith

Keyword(s):

Monte Carlo Simulation ◽

Monte Carlo ◽

High Speed ◽

Very High

Download Full-text

Fraud Detection in Financial Statements Applying Benford's Law with Monte Carlo Simulation

Acta Oeconomica ◽

10.1556/032.2019.69.2.4 ◽

2019 ◽

Vol 69 (2) ◽

pp. 217-239

Author(s):

Vladan Pavlović ◽

Goranka Knežević ◽

Marijana Joksimović ◽

Dušan Joksimović

Keyword(s):

Monte Carlo Simulation ◽

Monte Carlo ◽

Frequency Distribution ◽

High Probability ◽

Financial Statements ◽

Financial Statement ◽

Benford’S Law ◽

Financial Reports ◽

Benford's Law ◽

Very High

Benford's Law is a useful tool for detecting fraud in financial statements. In this paper we test the financial item named ‘Work performed by the undertaking for its own purpose and capitalised’ applying this tool. The data are taken from the financial reports of all companies submitted to the Serbian Business Register Agency for the period of 2008–2013. Our conclusion shows that there is a very high probability that the frequency distribution of the second digit does not satisfy Benford's Law. In other words, it implies that certain manipulations have been usually done with the second digit of the aforementioned item in the financial statement. This research confirms our hypothesis that financial statement frauds are usually conducted using the second digit.

Download Full-text

Hadronic flares and associated neutrinos for Markarian 421

Proceedings of the International Astronomical Union ◽

10.1017/s174392131500215x ◽

2014 ◽

Vol 10 (S313) ◽

pp. 177-178 ◽

Cited By ~ 1

Author(s):

Antonio Marinelli ◽

Barbara Patricelli ◽

Nissim Fraija

Keyword(s):

Monte Carlo Simulation ◽

Monte Carlo ◽

Neutrino Flux ◽

High Energy ◽

Neutrino Telescope ◽

Bl Lac Objects ◽

Markarian 421 ◽

Bl Lac ◽

Very High Energy ◽

Very High

AbstractMarkarian 421 (Mrk 421) is one of the brightest, fastest and closest BL Lac objects known. Its very high energy (VHE) spectrum has been successfully modeled with both leptonic and hadronic models and no conclusive results have been achieved yet about the origin of its VHE emission. Here we investigate the possibility that a fraction of the VHE flares of Mrk 421 are due to hadronic processes and calculate the expected associated neutrino flux. We introduce the obtained neutrino flux in a Monte Carlo simulation to see the expectation for a km3 Cherenkov neutrino telescope.

Download Full-text

Monte Carlo Simulation in Discharge at Very High E/n Condition

IEEJ Transactions on Fundamentals and Materials ◽

10.1541/ieejfms1990.116.5_406 ◽

1996 ◽

Vol 116 (5) ◽

pp. 406-411

Author(s):

Yuichiro Shimizu ◽

Motoshige Yumoto ◽

Takao Sakai

Keyword(s):

Monte Carlo Simulation ◽

Monte Carlo ◽

Very High

Download Full-text

Monte Carlo Algorithms for Moments of Transition Arrays

International Astronomical Union Colloquium ◽

10.1017/s0252921100107468 ◽

1988 ◽

Vol 102 ◽

pp. 79-81

Author(s):

A. Goldberg ◽

S.D. Bloom

Keyword(s):

Monte Carlo ◽

State Vector ◽

Basis Vector ◽

Collective State ◽

Dispersion Characteristics ◽

Dipole Strength ◽

The Third ◽

Monte Carlo Algorithms ◽

Third Moment ◽

Very High

AbstractClosed expressions for the first, second, and (in some cases) the third moment of atomic transition arrays now exist. Recently a method has been developed for getting to very high moments (up to the 12th and beyond) in cases where a “collective” state-vector (i.e. a state-vector containing the entire electric dipole strength) can be created from each eigenstate in the parent configuration. Both of these approaches give exact results. Herein we describe astatistical(or Monte Carlo) approach which requires onlyonerepresentative state-vector |RV> for the entire parent manifold to get estimates of transition moments of high order. The representation is achieved through the random amplitudes associated with each basis vector making up |RV>. This also gives rise to the dispersion characterizing the method, which has been applied to a system (in the M shell) with≈250,000 lines where we have calculated up to the 5th moment. It turns out that the dispersion in the moments decreases with the size of the manifold, making its application to very big systems statistically advantageous. A discussion of the method and these dispersion characteristics will be presented.

Download Full-text

Electron Scattering in Solids

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100133618 ◽

1990 ◽

Vol 48 (2) ◽

pp. 4-5

Author(s):

Ryuichi Shimizu ◽

Ze-Jun Ding

Keyword(s):

Monte Carlo Simulation ◽

Monte Carlo ◽

Angular Distribution ◽

Elastic Scattering ◽

Electron Scattering ◽

Cross Sections ◽

Expansion Method ◽

Electron Excitation ◽

Partial Wave Expansion ◽

Backscattered Electrons

Monte Carlo simulation has been becoming most powerful tool to describe the electron scattering in solids, leading to more comprehensive understanding of the complicated mechanism of generation of various types of signals for microbeam analysis.The present paper proposes a practical model for the Monte Carlo simulation of scattering processes of a penetrating electron and the generation of the slow secondaries in solids. The model is based on the combined use of Gryzinski’s inner-shell electron excitation function and the dielectric function for taking into account the valence electron contribution in inelastic scattering processes, while the cross-sections derived by partial wave expansion method are used for describing elastic scattering processes. An improvement of the use of this elastic scattering cross-section can be seen in the success to describe the anisotropy of angular distribution of elastically backscattered electrons from Au in low energy region, shown in Fig.l. Fig.l(a) shows the elastic cross-sections of 600 eV electron for single Au-atom, clearly indicating that the angular distribution is no more smooth as expected from Rutherford scattering formula, but has the socalled lobes appearing at the large scattering angle.

Download Full-text

Determination of Stoichiometry of GaAs Component in (Gaas)Ge Epitaxially Grown Thin Films by Electron Microprobe X-Ray Analysis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100134922 ◽

1990 ◽

Vol 48 (2) ◽

pp. 264-265

Author(s):

D. R. Liu ◽

S. S. Shinozaki ◽

R. J. Baird

Keyword(s):

Thin Film ◽

Thin Films ◽

Monte Carlo Simulation ◽

Monte Carlo ◽

Compound Semiconductors ◽

Energy Dispersive Analysis ◽

X Ray ◽

Metastable Alloys ◽

Lower Voltage

The epitaxially grown (GaAs)Ge thin film has been arousing much interest because it is one of metastable alloys of III-V compound semiconductors with germanium and a possible candidate in optoelectronic applications. It is important to be able to accurately determine the composition of the film, particularly whether or not the GaAs component is in stoichiometry, but x-ray energy dispersive analysis (EDS) cannot meet this need. The thickness of the film is usually about 0.5-1.5 μm. If Kα peaks are used for quantification, the accelerating voltage must be more than 10 kV in order for these peaks to be excited. Under this voltage, the generation depth of x-ray photons approaches 1 μm, as evidenced by a Monte Carlo simulation and actual x-ray intensity measurement as discussed below. If a lower voltage is used to reduce the generation depth, their L peaks have to be used. But these L peaks actually are merged as one big hump simply because the atomic numbers of these three elements are relatively small and close together, and the EDS energy resolution is limited.

Download Full-text