Influence Of Different Models Research Articles

Sensitivity of seismic hazard results to alternative seismic source and magnitude-recurrence models: a case study for Jordan

Influence of different models and assumptions with respect to seismic source modelling and magnitude distribution on seismic hazard results is examined, taking Jordan as a case study. Four alternative models, which are based on different combinations of seismic source models and magnitude-recurrence relationships, are considered. Seismic hazard curves obtained at four different sites in Jordan according to these four models are compared. In order to display the magnitude of spatial variation of peak ground acceleration (PGA) values obtained from these models, difference maps for return periods of 475 and 2475 years are constructed. Logic tree method is applied to aggregate the results calculated based on different models and assumptions. Then, best estimate seismic hazard maps for PGA and spectral acceleration at 0.2 and 1.0 s corresponding to return periods of 475 and 2475 years are plotted.

Research on Improving Take-Off Characteristics of Fly Wing with a New Constitution

The take-off control of UAV with fly wing layout is limited by its relatively lower pitch moment. This paper gained the state parameters of a few groups of taking off model by means of numerical simulation. The influence of different models on take-off distance, take-off angle of attack (AOA), take-off safe speed and c.g. location was then analyzed. Based on the analysis, a new fly wing constitution was designed and the corresponding take-off control scheme was suggested as well. Finally, the flight test results shows that this fly wing constitution can gain better take-off control characteristics.

Comparison of emitter saturation current densities determined by injection‐dependent lifetime spectroscopy in high and low injection regimes

ABSTRACTThe determination of the emitter saturation current density J0e of symmetrical test structures, analyzed by injection‐dependent lifetime spectroscopy (IDLS), in high as well as in low injection regimes is compared. A detailed investigation of the influence of different models for the Auger recombination on the evaluation of the measured minority carrier lifetime is performed. It can be concluded that a good agreement for the extraction of J0e under high and low injection conditions for lightly and highly doped emitters on textured and untextured surfaces was obtained if the Auger parameterization of Kerr et al. is applied. For deep‐diffused emitter profiles on textured surfaces a significant increase of J0e well above the geometrical surface area ratio of untextured and textured surfaces of 1.7 was observed. A verification of the experimentally determined values for J0e is performed by numerical device simulations. The simulated surface recombination velocity for the investigated emitter doping profiles is in good agreement to analytical calculations. Copyright © 2010 John Wiley & Sons, Ltd.

Influence of descriptions of shock absorbers on the nonlinear vertical vibrations of armored vehicle hull

Correlations which describe the gain-frequency characteristic of vertical vibrations of armoured vehicle hull are received in a parametrical form. Research of influence of different models of resistance forces of shock absorbers and resilient elements on the nonlinear hull vibrations is conducted.

Contact-layer method in adhesive mechanics: Adhesive strength during normal detachment

The contact-layer method is used to solve the problem of stressed-deformed state and strength in the adhesive attachment model, designed for normal detachment tests. The influence of different model and experimental parameters on the normal destructive stress measured in experiments is studied. It is shown that tangent stresses are distributed nonuniformly over the sticking area and that the strength in the model is determined by the competition of normal and maximum tangent stresses.

Making Civil Society Work: Models of Democracy and Their Impact on Civic Engagement

This article evaluates the influence of different models of democracy on individual volunteering in associations and organizations. More precisely, we investigate the extent to which the degree of liberal and participatory conceptions of democracy respectively shapes the conditions under which voluntary engagement thrives. We apply multilevel analysis—a method that corresponds well to the central hypothesis of institutional approaches and is most suitable for modeling the relationship between the democratic context and individual volunteering. We show that both a representative conception of democracy, as well as strong direct democracy, leads to advantageous conditions for civic engagement. In contrast, if the two models of democracy are combined, the two different logics of the democratic process disturb one another, resulting in less voluntary engagement.

Absolute measurements of electron-loss cross sections ofHe+andC3+with atomic hydrogen at intermediate velocities

Cross sections for electron loss of ${\mathrm{He}}^{+}$ and ${\mathrm{C}}^{3+}$ projectile ions on atomic and molecular hydrogen were measured in the $0.5\ensuremath{-}\mathrm{MeV}<~E<~3.5\ensuremath{-}\mathrm{MeV}$ energy range. The measurements of the ${\ensuremath{\sigma}}_{{\mathrm{H}}_{2}}/{\ensuremath{\sigma}}_{\mathrm{H}}$ cross section ratios were made by using an absolutely calibrated hydrogen furnace. The influence of different models describing the form factor of molecular hydrogen is examined by means of the ratio ${\ensuremath{\sigma}}_{{\mathrm{H}}_{2}}/{\ensuremath{\sigma}}_{\mathrm{H}},$ which is sensitive to the model adopted, particularly in the case of ${\mathrm{He}}^{+}$ projectiles. The general behavior of the measured data is analyzed within the independent electron approximation including the electron loss (screening and antiscreening contributions), electron capture, and target ionization channels. The connection between the antiscreening mode and the electron impact ionization of multicharged ions is explored.

The influence of different models in obtaining multiple solutions in distillation columns

AbstractThis paper is about the sensitivity of detection of multiple solutions to the structures or parameters incorporated in the equation system that represents a distillation column. The performance of different column simulation models, generally carried out in commercial simulators, is tested to detect multiplicity. The influence of the physicochemical estimating methods and the adopted numeric strategies to solve distillation problems is considered. Important behavioral differences have been found according to the model, the calculation method and the thermodynamic properties package used. Besides, the starting point is very important in the search of the hysteresis loop.

Energy-filtered transmission electron microscopy of Si mGe n superlattices and SiGe heterostructures I. Experimental results

Energy-filtered transmission electron microscopy has been applied to SiGe superlattices and layered heterostructures in order to explore detection and resolution limits of elemental distribution images obtained by electron spectroscopic imaging (ESI). A Zeiss EM 912 Omega transmission electron microscope with an integrated imaging Omega energy filter at 120 keV and the JEOL ARM equipped with a GATAN imaging filter at 1250 keV have been used. The filters selected inelastically scattered electrons corresponding to the inner-shell losses of the Si L edge. The three-window technique was applied to obtain Si distribution images. ESI was performed on cross-section TEM samples of short-period Si m Ge n superlattices ( m, n: number of monolayers in the layer sequence), ultra-thin individual layers, and Si 1 − y Ge y alloy buffer systems with composition gradient (0 < y < 0.4). Influences of different models for background subtraction and of correlation methods for specimen drift correction were investigated.

Some comparisons of orbit determination and parameter estimation based on LAGEOS 1 and LAGEOS 2 data

The modelling accuracy of the LAGEOS 1 orbit was continously improved since its launch in 1976. In spite of these experiences the modelling accuracy of LAGEOS 2 is still about 20 per cent worse. Considering e. g. only the influence of different gravity field models it has been shown that the orbital fits for arc lengths of one month is generally about 25 mm for LAGEOS 1 and more than 30 mm for LAGEOS 2. This is mainly due to the fact that LAGEOS 2 has not yet been used for the determination of most gravity field models. The influences of different model parameters on the estimation of station coordinates, Earth rotation parameters, the geogravitational coefficient, the radiation pressure coefficient, and the empirical acceleration has been studied. The differences and peculiarities of both satellites are discussed. Although the analysis of LAGEOS 2 data still does not reach the high level of LAGEOS 1 combination solutions using both satellites allow new insights, higher accuracies, and a higher time resolution for the parameters and phenomena investigated.

Wave Transmission and Energy Dissipation at Structural and Machine Joints

The dynamics of composed structures is influenced by the transfer behavior of interfaces of bolted, riveted, and compression joints. The measured nonlinear behavior of such joints is represented by equivalent linearized models and coupled with models of the members. Excitations by incident flexural waves, as well as longitudinal waves, are discussed. Characteristics of wave transmission, wave reflection, and energy dissipation of jointed beams are calculated. The influence of different models of joints is compared. A test setup for experimental vertification is proposed.