Musa I.A.,Duhok University
Structural Engineering and Mechanics | Year: 2016
Consistent finite strain Plate constitutive relations are derived based on a hyperelastic formulation for an isotropic material. Plate equilibrium equations under finite strain are derived following a static kinematic approach. Three Euler angles and four shear angles, based on Timoshenko beam theory, represent the kinematics of the deformations in the plate cross section. The Green deformation tensor has been expressed in term of a deformation tensor associated with the deformation and stretches of an embedded plate element. Buckling formulation includes the in-plane axial deformation prior to buckling and transverse as well as in-plane shear deformations. Numerical results for a simply supported thick plate under uni-axial compression force are presented. Copyright © 2016 Techno-Press, Ltd.
Eesa A.S.,University of Zakho |
Orman Z.,Istanbul University |
Brifcani A.M.A.,Duhok University
Expert Systems with Applications | Year: 2015
This paper presents a new feature-selection approach based on the cuttlefish optimization algorithm which is used for intrusion detection systems (IDSs). Because IDSs deal with a large amount of data, one of the crucial tasks of IDSs is to keep the best quality of features that represent the whole data and remove the redundant and irrelevant features. The proposed model uses the cuttlefish algorithm (CFA) as a search strategy to ascertain the optimal subset of features and the decision tree (DT) classifier as a judgement on the selected features that are produced by the CFA. The KDD Cup 99 dataset is used to evaluate the proposed model. The results show that the feature subset obtained by using CFA gives a higher detection rate and accuracy rate with a lower false alarm rate, when compared with the obtained results using all features. © 2014 Elsevier Ltd.
Hassan L.H.,Duhok University |
Moghavvemi M.,University of Malaya |
Almurib H.A.F.,University of Nottingham Malaysia Campus |
Muttaqi K.M.,University of Wollongong |
Ganapathy V.G.,University of Malaya
International Journal of Electrical Power and Energy Systems | Year: 2014
This paper describes a method to determine the optimal location and the number of multi-machine power system stabilizers (PSSs) using participation factor (PF) and genetic algorithm (GA). The PF method is primarily used for number estimation and to identify the location of the PSSs, while the GA is applied to further reduce the number of PSSs, resulting in the optimization of their parameters and locations under different operating conditions. The problem is presented as a multi-objective optimization problem; maximizing the damping ratio of the electromechanical modes using different numbers of PSSs. The approach is successfully tested on the New England-New York interconnected system (16-machine and 68-bus), and its effectiveness in damping of local and inter-area modes of oscillations was proven. It is also compared to two other methods, which use only GA, in terms of damping ratio and computation time. In addition, the proposed approach demonstrates better performance compared to a fuzzy-based PSS when applied to the Iraqi National Super Grid System (INSGS). © 2013 Elsevier Ltd. All rights reserved.
Mizzouri N.S.,University of Malaya |
Mizzouri N.S.,Duhok University |
Shaaban M.G.,University of Malaya
Journal of Hazardous Materials | Year: 2013
This study analyzes the effects of toxic, hydraulic, and organic shocks on the performance of a lab-scale sequencing batch reactor (SBR) with a capacity of 5. L. Petroleum refinery wastewater (PRWW) was treated with an organic loading rate (OLR) of approximately 0.3. kg chemical oxygen demand (COD)/kg MLSS. d at 12.8. h hydraulic retention time (HRT). A considerable variation in the COD was observed for organic, toxic, hydraulic, and combined shocks, and the worst values observed were 68.9, 77.1, 70.2, and 57.8%, respectively. Improved control of toxic shock loads of 10 and 20. mg/L of chromium (VI) was identified. The system was adversely affected by the organic shock when a shock load thrice the normal value was used, and this behavior was repeated when the hydraulic shock was 4.8. h HRT. The empirical recovery period was greater than the theoretical period because of the inhibitory effects of phenols, sulfides, high oil, and grease in the PRWW. The system recovery rates from the shocks were in the following order: toxic, organic, hydraulic, and combined shocks. System failure occurred when the combined shocks of organic and hydraulic were applied. The system was resumed by replacing the PRWW with glucose, and the OLR was reduced to half its initial value. © 2013 Elsevier B.V.
Ibrahim H.H.,Duhok University
European Surgery - Acta Chirurgica Austriaca | Year: 2016
Summary: Background: Hepatic hydatid cystic disease continues to be a serious health problem and is endemic in Iraq. There are of two types of cysts: noncomplicated and complicated cysts. Open surgery is widely practiced for both types. The aim of this study was to evaluate the clinical features, management, and outcome of surgical treatment in both types of cyst. Summary: Methods: The study included 150 patients operated on between 1996 and 2014. The patients’ demographic data, location, number, size, type of cysts, surgical procedure performed, morbidity, recurrences, and duration of hospital stay were recorded. Summary: Results: There were 102 female and 48 male patients with an age range of 4–70 years. There were more patients with noncomplicated cysts than complicated cysts – 94 and 56 patients, respectively. The complicated disease group had significantly more pronounced clinical presentations (p < 0.001) and higher postoperative morbidity (p < 0.001), and without significant change in recurrence rate (p = 0.059). Mean postoperative hospitalization time for noncomplicated cysts was 3.2 days, and for complicated cysts 5.6 days (p < 0.001). Summary: Conclusion: The most common type of hydatid cyst is the noncomplicated type, which has lower complication rates and shorter hospital stay regardless of the management technique of the cyst cavity. Therefore, complicated and noncomplicated cysts should be considered as different forms of the disease entity with different outcomes. © 2016 Springer-Verlag Wien