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Go to Editorial ManagerData sets of highest monthly rainfall for the period (1887-1958) are used for evaluating the proper theoretical statistical distribution of extreme monthly rainfall in Baghdad city. The frequency analyses and most statistical test were done using a commercial version of HYFRAN. Five distributions are used in this research, which are: - Normal, Pearson Type III, Lognormal, 3-parameter lognormal and Gumbel. Estimation of theoretical distribution is achieved by using maximum likelihood method and adequacy test is carried out using chi-square test. Lognormal, 3-parameter lognormal, and Gumbel distributions seem to be suitable for representing of maximum monthly rainfall in the study area.
In the realm of cryptography, the Substitution-box (S-box) is a critical component for enhancing the security of encryption algorithms. The inherent characteristics of Chaos, such as sensitivity to beginning conditions and unpredictability, make it a highly suitable choice for encryption applications. In this paper, proposed a method for generating S-Boxes using 3D chaotic maps algorithms including (Cat map, Henon map, Sine map, and Cosine map). The primary focus is on enhancing the security and efficiency of cryptographic systems by leveraging the inherent complexity and unpredictability of chaotic maps. The design methodology focuses on achieving high non-linearity, optimal avalanche effect, and Strict Avalanche Criterion ( SAC ), ensuring that minor changes in plaintext result in significant alterations in the ciphertext. Our study presents a detailed analysis of the generated S-Boxes, demonstrating their robustness against common cryptographic attacks. Key findings include significant improvements in nonlinearity, differential uniformity, and bijectivity compared to traditional methods. The test findings and performance analysis indicate that our proposed S-Box exhibits much lower values of Linear Probability ( LP ) and Differential Probability ( DP ), while maintaining a suitable average value of nonlinearity. Additionally, discussed the broader implications of our findings, emphasizing how the proposed method can be employed to produce high-quality analytical results that enhance the security measures of cryptographic applications. This work adds valuable context to existing research and highlights the potential for our model to outperform conventional S-Box generation techniques.
This paper presents the effect of fiber orientation angle on the stress intensity factor SIF for carbon epoxy composite plates with single-edge, center, and inclined cracks of varying lengths under tensile load. The stress intensity factor and shape factor were calculated individually for each case, with nine different fiber orientation angles computed using the extended finite element method XFEM concepts. It is found the stress intensity factor increases with increasing crack lengths while the shape factor decreases. In the case of single edge cracks, the SIF increases in the average value reached (173 %) for composite plates with different fiber orientation angles, while in the case of the center crack, the average value of SIF reaches (81 %). It was observed in this study that the increases in stress intensity factor and the decreases in the shape factor with different crack lengths were more stable in the composite plate with a fiber orientation angle of 75°. The higher values of SIF at an angle of 75° are because of the high probability of fiber slippage at 75° due to induced shear stresses in addition to the tensile stresses at the fiber-matrix interface. As a result, the crack tip has a high-stress intensity factor.
In this paper, the Weibull uni-axial and multi-axial distribution function for polyethylene pips under pressure loading were developed and analyzed taking account of residual stress. Tensile test was achieved to determine mechanical properties and the Weibull parameters. Experimental method using the hole- drilling strain-gage method was used to measure the residual stresses in PE pipe and compare with that obtained from numerical finite element method (FEM). The obtained results show that there is a convergence between uni-axial and multi-axial distribution function, but multi-axial distribution function give large values compared to uni-axial distribution function. It was observed that the residual stresses have influence on failure assessment diagram and causes translation from elastic-plastic failure to brittle failure.
Time series analysis for hydrological phenomena has an important role in water resources engineering. In this study, seven models of ARIMA family are tested for forecasting the monthly discharge at Hit station on Euphrates river in Iraq. The statistical analyses were done for models with help of IBM SPSS statistics 21 software, The number of observations used is equal to 480 reading, start from October 1932 and end at September 1972, this period represents the near-natural stream flow of the river before the construction of dams in Syria and Turkey. Statistical tests such as T-test and F-test were used to detect any change in Mean and Variance at 95% significant probability level. Results showed that the best model is (2,0,1)×(0,1,1) 12 which gives minimum error and good agreement between observed and forecast discharge.
The influence of time delay on the statistical behavior of the first-order phase-locked-loop is investigated in VHF and UHF synchronous communication systems. The Fokker-Plank equation has been proposed to estimate the probability density function (pdf) of phase fluctuations as well as the average time to loss lock in the presence of noise. The result reveal that the degradation in the loop performance occurs under various conditions of detuning when the inherent time delay is present
Smart prostheses hands have seen vast advancement in recent years. Amputees with upper hand loss have better access to intelligent prostheses that help them with their daily life activities. Smart prostheses however are still in development and have a few disadvantages, such as being expensive, complex, require training and being error prone in some cases. In this paper a simple, cost effective, practical upper limb prosthetic device is proposed that uses pressure sensors to acquire the action intent from the amputees. The pressure sensor serves as input signal to the Control Unit (CU). Using a selector keyboard, the amputee can choose between five predefined movements. The advantages of the proposed system compared to other prostheses using EMG, EEG, Voice is design simplicity and cost. The approximate cost of the proposed prosthetic hand is less than 200$. In addition, some of the complexities and error prone properties of the other alternatives are avoided and less probability of use fatigue is achieved.