Preferred Language
Articles
/
bhZMGocBVTCNdQwCGzf_
Reliability Analysis of an Uncertain Single Degree of Freedom System Under Random Excitation
...Show More Authors

In practical engineering problems, uncertainty exists not only in external excitations but also in structural parameters. This study investigates the influence of structural geometry, elastic modulus, mass density, and section dimension uncertainty on the stochastic earthquake response of portal frames subjected to random ground motions. The North-South component of the El Centro earthquake in 1940 in California is selected as the ground excitation. Using the power spectral density function, the two-dimensional finite element model of the portal frame’s base motion is modified to account for random ground motions. A probabilistic study of the portal frame structure using stochastic finite elements utilizing Monte Carlo simulation is presented using the finite element program ABAQUS. The dynamic reliability and probability of failure of stochastic and deterministic structures based on the first-passage failure were examined and evaluated. The results revealed that the probability of failure increases due to the randomness of stiffness and mass of the structure. The influence of uncertain parameters on reliability analysis depends on the extent of variance in structural parameters.

Scopus Crossref
View Publication
Publication Date
Tue Sep 01 2015
Journal Name
Journal Of Engineering
Performance Enhancement of a Piezoelectric Harvester Included into an Autonomous System
...Show More Authors

Autonomous systems are these systems which power themselves from the available ambient energies in addition to their duties. In the next few years, autonomous systems will pervade society and they will find their ways into different applications related to health, security, comfort and entertainment. Piezoelectric harvesters are possible energy converters which can be used to convert the available ambient vibration energy into electrical energy. In this contribution, an energy harvesting cantilever array with magnetic tuning including three piezoelectric bimorphs is investigated theoretically and experimentally. Other than harvester designs proposed before, this array is easy to manufacture and insensitive to manufacturi

... Show More
View Publication Preview PDF
Publication Date
Sun Jul 01 1990
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
AQUATIC INVERTEBRATE FAUNA OF AN UPLAND RESERVOIR SYSTEM, CO-WICKLOW, IRELAND
...Show More Authors

Littoral and benthic invertebrates from Roundwood Reservoir System were sampled. Oligochaetes and molluscs were the dominant organisms in the littoral and benthic areas Trichopterans and chironomids were the most abundant insect groups. Scuba diving samples reinforced that view. Other groups of macroinvertebrates were poorly represented. Vertical and horizontal hauls of zooplankton revealed that there were twelve species of zooplankton present. Daphnia hyalina Leydig and Bosmina coregoni Baird were the two dominant species.

View Publication Preview PDF
Publication Date
Mon Nov 11 2019
Journal Name
Spe
Modeling Rate of Penetration using Artificial Intelligent System and Multiple Regression Analysis
...Show More Authors
Abstract<p>Over the years, the prediction of penetration rate (ROP) has played a key rule for drilling engineers due it is effect on the optimization of various parameters that related to substantial cost saving. Many researchers have continually worked to optimize penetration rate. A major issue with most published studies is that there is no simple model currently available to guarantee the ROP prediction.</p><p>The main objective of this study is to further improve ROP prediction using two predictive methods, multiple regression analysis (MRA) and artificial neural networks (ANNs). A field case in SE Iraq was conducted to predict the ROP from a large number of parame</p> ... Show More
View Publication Preview PDF
Crossref (5)
Crossref
Publication Date
Mon Nov 01 2021
Journal Name
Chaos, Solitons &amp; Fractals
Dynamic analysis of a harvested fractional-order biological system with its discretization
...Show More Authors

View Publication
Scopus (19)
Crossref (15)
Scopus Clarivate Crossref
Publication Date
Mon Jun 19 2023
Journal Name
Journal Of Engineering
REVIEW THE ASSESSMENT OF EFFECTS OF LOST TIME INJURIES IN AN INDUSTRIAL SYSTEM BY USING AN EXPLANATORY PROGRAM
...Show More Authors

Health and safety problem can be described by statistics it can only be understood by knowing and feeling the pain, suffering, and depression. Health and safety has a legal responsibility to protect it for everyone who can affect in the workplace. This includes manufacturers, suppliers, designers and controllers of work places and employees. Work injury is one of the major problems in manufacturing and production systems industries; it is reduced production efficiency and affects the cost. To gain flexibility from a traditional manufacturing system and production efficiency, this paper is about the application of estimating technology to preview and synthesis of Lost Time of Work Injuries in industry systems aims to provide a safe workin

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Jun 06 2010
Journal Name
Baghdad Science Journal
Stochastic Non-Linear Pseudo-Random Sequence Generator
...Show More Authors

Many of the key stream generators which are used in practice are LFSR-based in the sense that they produce the key stream according to a rule y = C(L(x)), where L(x) denotes an internal linear bit stream, produced by small number of parallel linear feedback shift registers (LFSRs), and C denotes some nonlinear compression function. In this paper we combine between the output sequences from the linear feedback shift registers with the sequences out from non linear key generator to get the final very strong key sequence

View Publication Preview PDF
Crossref
Publication Date
Thu Jun 01 2017
Journal Name
International Journal Of Science And Research
Precise Solutions of a Viscoelastic Fluid Flow in an Annular Pipe under an Impulsive Pressure with the Fractional Generalized Burgers' Model
...Show More Authors

This paper deals with an analytical study of the flow of an incompressible generalized Burgers’ fluid (GBF) in an annular pipe. We discussed in this problem the flow induced by an impulsive pressure gradient and compare the results with flow due to a constant pressure gradient. Analytic solutions for velocity is earned by using discrete Laplace transform (DLT) of the sequential fractional derivatives (FD) and finite Hankel transform (FHT). The influences of different parameters are analyzed on a velocity distribution characteristics and a comparison between two cases is also presented, and discussed in details. Eventually, the figures are plotted to exhibit these effects.

View Publication
Publication Date
Sun Jul 01 2007
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Chronic diarrhea in under 2 year aged children, a ten year retrospective analysis
...Show More Authors

Background: Diarrheal diseases are still a major public health problem especially in developing countries, due to their high morbidity & mortality rates, moreover the lagest
number of deaths with diarrheal diseases are due to persistent diarrheal states.We attemted to evaluate the size of the problem in our infants, and assess risk factors & outcome.
Methods: A retrospective study was performed in Al-Kadhemya teaching hospital, to evaluate diarrheal cases in under 2 years of age children , admitted to hospital during the period (Dec. 1991- Dec. 2001), from a total of 863, chronic diarrheal cases formed 286 (33.14%) that were evaluated for certain variables; epidemiology & risk factors etiology ,

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Dec 22 2020
Journal Name
Lecture Notes In Civil Engineering
Geometric Nonlinear Synthetic Earthquake Analysis of Base Isolated Tall Steel Buildings Under Site-Specific Seismic Loading
...Show More Authors

View Publication
Scopus (1)
Crossref (1)
Scopus Crossref
Publication Date
Sun Dec 01 2019
Journal Name
Al-khwarizmi Engineering Journal
Free Vibration Analysis of Laminated Composite Plates with General Boundary Elastic Supports Under Initial Thermal Load
...Show More Authors

Free vibration behavior was developed under the ratio of critical buckling temperature of laminated composite thin plates with the general elastic boundary condition. The equations of motion were found based on classical laminated plate theory (CLPT) while the solution functions consists of trigonometric function and a continuous function that is added to guarantee the sufficient smoother of the so-named remaining displacement function at the boundaries, in this research, a modified Fourier series were used, a generalized procedure solution was developed using Ritz method combined with the imaginary spring technique. The influences of many design parameters such as angles of layers, aspect ratio, thickness ratio, and ratio of initial in-

... Show More
View Publication Preview PDF
Crossref