In the current paper, the effect of fear in three species Beddington–DeAngelis food chain model is investigated. A three species food chain model incorporating Beddington-DeAngelis functional response is proposed, where the growth rate in the first and second level decreases due to existence of predator in the upper level. The existence, uniqueness and boundedness of the solution of the model are studied. All the possible equilibrium points are determined. The local as well as global stability of the system are investigated. The persistence conditions of the system are established. The local bifurcation analysis of the system is carried out. Finally, numerical simulations are used to investigate the existence of chaos and understand the effect of varying the system parameters. It is observed that the existence of fear up to a critical value has a stabilizing effect on the system; otherwise it works as an extinction factor in the system.
In this research, the nonparametric technique has been presented to estimate the time-varying coefficients functions for the longitudinal balanced data that characterized by observations obtained through (n) from the independent subjects, each one of them is measured repeatedly by group of specific time points (m). Although the measurements are independent among the different subjects; they are mostly connected within each subject and the applied techniques is the Local Linear kernel LLPK technique. To avoid the problems of dimensionality, and thick computation, the two-steps method has been used to estimate the coefficients functions by using the two former technique. Since, the two-
... Show MoreA seemingly uncorrelated regression (SUR) model is a special case of multivariate models, in which the error terms in these equations are contemporaneously related. The method estimator (GLS) is efficient because it takes into account the covariance structure of errors, but it is also very sensitive to outliers. The robust SUR estimator can dealing outliers. We propose two robust methods for calculating the estimator, which are (S-Estimations, and FastSUR). We find that it significantly improved the quality of SUR model estimates. In addition, the results gave the FastSUR method superiority over the S method in dealing with outliers contained in the data set, as it has lower (MSE and RMSE) and higher (R-Squared and R-Square Adjus
... Show MoreThe variety of ideas and freedom of expression among the authors who are looking for everything new that serves the goals of musical and aesthetic expression, which calls for the use of traditional musical instruments with the great composition of musical instruments known as the orchestra represents a great challenge in several aspects. The incompetence of some of these instruments or limited capabilities or its costly method of performance sometimes forbids its use permanently in this great composition. It was necessary to have some problems facing the composer and the player on the one hand and the recipient on the other hand, who must be looking for perfection. Among those instruments that are used regularly in the works of the orche
... Show MoreThis study aimed at evaluating the torsional capacity of reinforced concrete (RC) beams externally wrapped with fiber reinforced polymer (FRP) materials. An analytical model was described and used as a new computational procedure based on the softened truss model (STM) to predict the torsional behavior of RC beams strengthened with FRP. The proposed analytical model was validated with the existing experimental data for rectangular sections strengthened with FRP materials and considering torque-twist relationship and crack pattern at failure. The confined concrete behavior, in the case of FRP wrapping, was considered in the constitutive laws of concrete in the model. Then, an efficient algorithm was developed in MATLAB environment t
... Show MoreThe researchers seek to shed light on the importance of accounting disclosure on social responsibility, and the research aims to provide a theoretical approach to social accounting and its disclosure, identify the concept of sustainable development, highlight the theoretical foundations of sustainable development and employ disclosure of social responsibility towards achieving the goals of sustainable development, and identify the impact of The accounting disclosure on social responsibility in achieving sustainable development goals, and the research problem can be reviewed by asking the following question (Does the accounting disclosure of the social responsibility of economic units contribute to achieving sustainable developmen
... Show MoreA total number of 33 isolates of Pseudomoans aeruginosa were collected from different clinical samples, such as: burn, wound and urine from patients attending Al-Yarmouk teaching hospital and some private clinical laboratories in Baghdad city through the period from October to December 2016. On the other hand, 21 isolates of P. aeruginosa were collected from 38 different food samples; such as: vegetables and fruits, from different local markets in Baghdad city during the period from November to December 2016. All isolates were identified by using different bacteriological and biochemical assays and confirmed by Vitek-2 identification system. The antimicrobial susceptibility test for clinical and food isolates towards 17 antimicrobial a
... Show MoreThe aim of this essay is to use a single-index model in developing and adjusting Fama-MacBeth. Penalized smoothing spline regression technique (SIMPLS) foresaw this adjustment. Two generalized cross-validation techniques, Generalized Cross Validation Grid (GGCV) and Generalized Cross Validation Fast (FGCV), anticipated the regular value of smoothing covered under this technique. Due to the two-steps nature of the Fama-MacBeth model, this estimation generated four estimates: SIMPLS(FGCV) - SIMPLS(FGCV), SIMPLS(FGCV) - SIM PLS(GGCV), SIMPLS(GGCV) - SIMPLS(FGCV), SIM PLS(GGCV) - SIM PLS(GGCV). Three-factor Fama-French model—market risk premium, size factor, value factor, and their implication for excess stock returns and portfolio return
... Show MoreThis study was carried out in the bee laboratory in the Faculty of Agriculture –University of Kufa in September 2021 to evaluate some protein sources and hive products against the oriental hornet Vespa orientalis Linnaeus 1771 (Hymenoptera: Vespidae). The food sources included: beef meat, gut fish, beef lung, honeybee, wax, propolis, pollen, bee worker, and water, in addition to control which was an empty petri dish. The number of visits and their duration were calculated. The results showed that the wasps preferred bee honey and wax significantly higher than the rest of the stimuli.