414 research outputs found

    A New Preconditioner on Gauss‐Seidel Method for H‐Matrices

    Get PDF
    In order to accelerate the convergency of Gauss‐Seidel method to solve systems of linear equations when the coefficient matrix is an H‐matrix, a new preconditioner is introduced. The convergency of the new preconditioned method is proved

    Signature of the maximally symmetric 2HDM via W±/Z -quadruplet productions at the LHC

    Get PDF
    We consider the maximally symmetric two-Higgs doublet model (MS-2HDM) in which the so-called Standard Model (SM) alignment can be achieved naturally by the virtue of an SO(5) symmetry imposed on the 2HDM. We investigate the signature of the MS-2HDM via → HX → VV ∗ X processes at the LHC for different values of tan β. We perform our calculations with next-to-leading-order (NLO) QCD accuracy, using the herwig7 multipurpose event generator at √s = 13 TeV center-of-mass energy. We show that the production of single SM-like Higgs bosons via W±/Z pairs is completely aligned with the SM. Interestingly, the presence of the heavy Higgs states significantly enhances the cross section for the W± /Z- quadruplet production channels in the low -p⊥ regions. These vital analyses may aid the future discovery of this minimal and very predictive extension of the SM and can be generalized to other realizations of the 2HDM

    Estimation of population dynamics parameters of Scomberomorus commerson using modal progression method in the Hormouzgan province waters

    Get PDF
    Scombermorus commerson is one of the most important commercial fish species in the Persian Gulf and Sea of Oman. To arrange for a sustainable fishing pattern, growth parameters, mortality and exploitation rates of the fish were estimated. Fish length data were collected from 4515 fishes, science April 2007 to March 2008 in three major artisanal fish-landing sites Bandar Lengeh, Bandar Abbas and Bandar Jask in Hormouzgan province waters. The Von Bertalanffy growth parameters (L∞ K and t _(0)) were estimated at 150.24 (cm), 0.66 year ^(-1) and -0.157 year, respectively. The results showed that S. commerson grows very fast in the first 2 years. The results indicated that S. commerson attains its fork length 80.3 cm at the end of first year. The fork length attained at the end of the second, third and fourth years were 114.1, 131.6 and 140.6 cm, respectively. Growth performance index (f) was calculated at 4.1 which were in agreement with the findings of the other studies in the Indian Ocean. Total, natural, fishing mortality and exploitation rate were estimated at 2.11, 0.67, 1.44 year ^(-1) and 0.64, respectively. Five cohorts were distinguished based on Bhattacharya's method

    Population dynamics of Sind Sardine, Sardinella sindensis, in coastal waters of Qeshm Island

    Get PDF
    Sardinella sindensis is economically the most important small pelagic fish species in the coastal area of Qeshm Island. Population dynamics of Sind sardinella from Qeshm Island coastal waters, during April 2005 to March 2006 were studied. The asymptotic length (Lx) and growth coefficient (K) were estimated at 178mm and 1.11yr ^(-1), respectively. The minimum and maximum T.L was recorded at 42 and 172mm respectively. The value of t0 was calculated at -0.17, and Tmax was estimated at 2.7 year. The Von Bertalanffy growth equation was obtained at L_(t) = 178^(1-exp(-1.1 l(t-(-0.17))) for this species. Total mortality (Z) rate was estimated to be 3.48yr ^(-1) (r ^(2) = 0.88) on length-converted catch curve method. The rates of natural mortality (M) based on Pauly's empirical equation, fishing mortality (F) and exploitation ratio were estimated at 1.13yr ^(-1), 2.35yr ^(-1) and 0.67, respectively. Four cohorts were distinguished annually based on Bhattacharya's method with mean length of 56, 89, 107 and 141mm. Maximum recruitment was in September at 18.62 percent. The length-weight relationship was determined as W= 0.000005 L ^(3.1399)

    Reproduction and feeding of Buccaneer anchovy (Encrasicholina punctifer) from coastal waters of Qeshm Island, the Persian Gulf

    Get PDF
    Encrasicholina punctifer is one of the dominant small pelagic and economically most important fishes of the Persian Gulf, especially in Qeshm Island's coastal waters. Specimens of the fish were collected monthly from the fishing area in the coastal waters of Qeshm Island by random sampling method. Investigation on biological parameters of E. punctifer continued from April 2005 to March 2006. E. punctifer is mainly caught by double-boat purse seine in this area. Reproductive studies showed that maturity season of the fish occur in August. The sex ratio fulfill the theoretical 1:1 (P>0.05). L sub(M50) was attained at a total length of 84 mm. The absolute fecundity was estimated at 1217 plus or minus 331. We showed that the species is planktonivore, its diet consisted of a board spectrum of food types, but crustaceans dominated the food with copepods and their eggs, naplius and semi digested copepods constituting 54% of the diet. The next major food groups found in the diet of the fish were Cyanophyceae 21%, Bacillariophyceae 11%, fish egg and scale 6%, Dinophyceae 4%, with Euglenahyceae, Chiorophyta, Dinoflagellates and others items consisting only 4% of the diet. Analysis of monthly variation in the stomach fullness indicated that feeding intensity fluctuated throughout the year, with the highest value in winter. Vacuity Index indicated this species was of semi-voracious appetite fishes
    corecore