29 research outputs found

    Stability analysis of a parametric family of seventh-order iterative methods for solving nonlinear systems

    Full text link
    [EN] In this paper, a parametric family of seventh-order of iterative method to solve systems of nonlinear equations is presented. Its local convergence is studied and quadratic polynomials are used to investigate its dynamical behavior. The study of the fixed and critical points of the rational function associated to this class allows us to obtain regions of the complex plane where the method is stable. By depicting parameter planes and dynamical planes we obtain complementary information of the analytical results. These results are used to solve some nonlinear problems. (C) 2017 Elsevier Inc. All rights reserved.This research was partially supported by Ministerio de Economia y Competitividad MTM2014-52016-C2-2-P and by Generalitat Valenciana PROMETEO/2016/089.Amiri, A.; Cordero Barbero, A.; Darvishi, M.; Torregrosa Sánchez, JR. (2018). Stability analysis of a parametric family of seventh-order iterative methods for solving nonlinear systems. Applied Mathematics and Computation. 323:43-57. https://doi.org/10.1016/j.amc.2017.11.040S435732

    Preserving the order of convergence: Low-complexity Jacobian-free iterative schemes for solving nonlinear systems

    Full text link
    [EN] In this paper, a new technique to construct a family of divided differences for designing derivative-free iterative methods for solving nonlinear systems is proposed. By using these divided differences any kind of iterative methods containing a Jacobian matrix in its iterative expression can be transformed into a "Jacobian-free" scheme preserving the order of convergence. This procedure is applied on different schemes, showing theoretically their order and error equation. Numerical experiments confirm the theoretical results and show the efficiency and performance of the new Jacobian-free schemes. (C) 2018 Published by Elsevier B.V.This research was partially supported by Ministerio de Economia y Competitividad MTM2014-52016-C2-2-P, MTM2015-64013-P and Generalitat Valenciana PROMETEO/2016/089.Amiri, A.; Cordero Barbero, A.; Darvishi, M.; Torregrosa Sánchez, JR. (2018). Preserving the order of convergence: Low-complexity Jacobian-free iterative schemes for solving nonlinear systems. Journal of Computational and Applied Mathematics. 337:87-97. https://doi.org/10.1016/j.cam.2018.01.004S879733

    A fast algorithm to solve systems of nonlinear equations

    Full text link
    [EN] A new HSS-based algorithm for solving systems of nonlinear equations is presented and its semilocal convergence is proved. Spectral properties of the new method are investigated. Performance profile for the new scheme is computed and compared with HSS algorithm. Besides, by a numerical example in which a two-dimensional nonlinear convection diffusion equation is solved, we compare the new method and the Newton-HSS method. Numerical results show that the new scheme solves the problem faster than the NewtonHSS scheme in terms of CPU -time and number of iterations. Moreover, the application of the new method is found to be fast, reliable, flexible, accurate, and has small CPU time.This research was partially supported by Ministerio de Economia y Competitividad, Spain under grants MTM2014-52016-C2-2-P and Generalitat Valenciana, Spain PROMETEO/2016/089.Amiri, A.; Cordero Barbero, A.; Darvishi, M.; Torregrosa Sánchez, JR. (2019). A fast algorithm to solve systems of nonlinear equations. Journal of Computational and Applied Mathematics. 354:242-258. https://doi.org/10.1016/j.cam.2018.03.048S24225835

    Biomass estimation of demersal resources in the Persian Gulf and Oman Sea by Swept Area Method

    Get PDF
    Regarding to monitor of demersal resources in the Persian Gulf and Oman Sea, and also biomass and CPUA estimation of them, a series of research cruises (5 cruises per year) were carried out by R/V Ferdows-1covering the area from 49 00 E in the west (Khoozestan provice) to 61 25 E in the east (Gwater) in a 5 years program form 2004 up to 2008 (no cruise in 2006). The study area was stratified into 17 strata (A to Q) of which 10 starta (A to J) were in the Persian Gulf and 7 strata (K to Q) were in the Oman Sea, covering the depths of 10-50m in the Persian Gulf and 10-100m in the Oman Sea. A total of 316 stations were randomly selected. The biomass and CPUA were estimated by Swept Area method. The comparison between two regions indicated that the percentage of density of demersal fishes in the Persian Gulf during years 2004, 2005, 2007 and 2008 were 3.3, 3.9, 2.3 and 2.4 times more than the Oman Sea and totally 70-80% of total biomass was calculated for the Persian Gulf. Also a comparison among 17 starta, the highest biomass was found for starta C & D in the Bushehr province waters. The amount of CPUA for both regions of the Persian Gulf and Oman Sea was compared and it was concluded that in years 2004 and 2005, the mean CPUA in the Persian Gulf was partially higher than the Oman Sea with 1.06 & 1.20 times more; and on the contrary for the next two years this value was higher in the Oman Sea with 1.3 times more. The highest CPUA of demersal resources for the Oman Sea belonged to the strata K & O for years 2004, 2007 and 2008 and for year 2005 was for L and strata. It can be concluded that the north-west of Oman Sea has the best condition of biomass of commercial and non-commercial species and the O stratum will be in the second ranking. With review the mean CPUA in different depth-layers for years 2004, 2005, 2007 and 2008, it was concluded that with increasing the depth, the mean CPUA is decreased in which the CPUA values in depth-layer 10-20m for these years were 8.3, 3.0, 2.1 & 1.6 times more than depth-layer 50-100m. The comparison of mean CPUA for 10 strata of the Persian Gulf showed that in years 2004 and 2005, the mean CPUA of demersal fishes in the Hormuzgan province waters was higher than in Bushehr province waters (1.2 times more). In total, the highest maen CPUA belonged to F (Naiband to Mogham) and G (Mogham to Farour) in Hormuzgan waters. On the contrary, in years 2007 and 2008 this value in Bushehr waters was 1.3 times higher than western part of Hormuzgan waters with the highest value in D stratum(Boordekhoon to Dayyer). Also the comparison of mean CPUA for different depth-layers, it was found that the mean CPUA has ascending trend with increasing the depth, with the highest value in depth-laer of 30-50m in which contains the 55-68% of total biomass. The lowest biomass is found in depth-layers of 10-30m. Totally, the minimum CPUA and biomass for both commercial and non-commercial species belonged to a stratum located in Khouzestan province waters and it was shown the over-exploitation of resources in this area. The comparison between commercial and non-commercial groups in both ecosystems , it was concluded that the density of commercial species was higher than non-commercial ones , and in all years the Persian Gulf indicated higher values than the Oman Sea

    The forward physics facility at the high-luminosity LHC

    Get PDF
    High energy collisions at the High-Luminosity Large Hadron Collider (LHC) produce a large number of particles along the beam collision axis, outside of the acceptance of existing LHC experiments. The proposed Forward Physics Facility (FPF), to be located several hundred meters from the ATLAS interaction point and shielded by concrete and rock, will host a suite of experiments to probe standard model (SM) processes and search for physics beyond the standard model (BSM). In this report, we review the status of the civil engineering plans and the experiments to explore the diverse physics signals that can be uniquely probed in the forward region. FPF experiments will be sensitive to a broad range of BSM physics through searches for new particle scattering or decay signatures and deviations from SM expectations in high statistics analyses with TeV neutrinos in this low-background environment. High statistics neutrino detection will also provide valuable data for fundamental topics in perturbative and non-perturbative QCD and in weak interactions. Experiments at the FPF will enable synergies between forward particle production at the LHC and astroparticle physics to be exploited. We report here on these physics topics, on infrastructure, detector, and simulation studies, and on future directions to realize the FPF's physics potential

    The global burden of cancer attributable to risk factors, 2010–19: a systematic analysis for the Global Burden of Disease Study 2019

    Get PDF
    BACKGROUND: Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. METHODS: The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk–outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. FINDINGS: Globally, in 2019, the risk factors included in this analysis accounted for 4·45 million (95% uncertainty interval 4·01–4·94) deaths and 105 million (95·0–116) DALYs for both sexes combined, representing 44·4% (41·3–48·4) of all cancer deaths and 42·0% (39·1–45·6) of all DALYs. There were 2·88 million (2·60–3·18) risk-attributable cancer deaths in males (50·6% [47·8–54·1] of all male cancer deaths) and 1·58 million (1·36–1·84) risk-attributable cancer deaths in females (36·3% [32·5–41·3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20·4% (12·6–28·4) and DALYs by 16·8% (8·8–25·0), with the greatest percentage increase in metabolic risks (34·7% [27·9–42·8] and 33·3% [25·8–42·0]). INTERPRETATION: The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden

    Numerical investigation for a hyperbolic annular fin with temperature dependent thermal conductivity

    Get PDF
    An annular fin of hyperbolic profile with temperature dependent thermal conductivity is studied by pseudospectral method. Graphs illustrating the effect of fin dimensions, surface convection characteristics and the thermal conductivity parameter on the thermal performance of the fin are presented and discussed. A comparison of the obtained numerical results is made with the closed form analytical solution available in the literature for the case of constant thermal conductivity. This comparison confirms the high accuracy of numerical results. When the thermal conductivity increases with temperature, the effect is to elevate both the temperature distribution in the fin and the fin efficiency. The converse is true when the thermal conductivity decreases with temperature

    Some exact and new solutions of the Nizhnik–Novikov–Vesselov equation using the Exp-function method

    Get PDF
    AbstractIn this paper, using the Exp-function method, we give some explicit formulas of exact traveling wave solutions for the Nizhnik–Novikov–Vesselov equation
    corecore