2760 research outputs found
Sort by
علاقة التمكين الإداري بالأداء الوظيفي
No full textص. 287-209أثرت البيئة الإقتصادية على إدارة الأعمال مما أدى الى تزايد أهمية العاملين في المؤسسات، وبالتالي برزت فكرة التمكين الذي يتضمن نقل السلطات الكافية للعاملين ليتمكنوا من أداء مهامهم دون تدخل مباشر من الإدارة، وذلك مع دعم قدراتهم ومهاراتهم، ومن ثم قياس أدائهم الوظيفي بناء على أهداف واضح
Efficient genetic algorithm for multi-objective robust optimization of machining parameters with taking into account uncertainties
No full textThe respect of the machined piece quality and productivity is closely related to the mastery of uncertain factors. Indeed, the efficient solutions obtained from the machining parameter optimization based on classical methods are assigned of uncertain deviations which affect the cutting process. In the present paper, we propose multi- and mono-objective optimization approach of parameter turning with taking into account both production constraints related to piece quality, to machine power, or to tool life, than uncertainty factors related to the tool wear and to piece geometry defaults. To this end, we developed and implemented an efficient genetic algorithm, based on an evaluation mechanism of “objective” functions, which integrate the Monte Carlo simulations to calculate the robustness of objective function and different constraints. Our approach has been validated by two applications implemented with Matlab™ for the minimization of cost and machining time, which has allowed obtaining simultaneously efficient and robust results and offering the possibility to choose beforehand a compromise between efficiency and robustness of solution
Crack growth estimation using model reduction and genetic algorithm
No full textIn this study we use the material elastic properties as a base, a tow dimensional cracked plate under traction is modelled by finite element method (FEM) than a reduced model is built using the proper orthogonal decomposition method (POD), the crack length is estimated as an inverse identification problem, basing on the deformation obtained from the boundary nodes of the structure considered as sensor points. A genetic algorithm (GA) is used for the minimization of the error function which is expressed as the difference between displacement field of the boundaries caused by the crack size proposed randomly by GA and the field measured at the actual identity. The approach presented accurate results and could guess the real crack size in a precession less that 10-6 of the cost function, proving its effectiveness even with a very low number of 4 sensors, and shows that the boundary displacement measurements are practical. The use of the reduced model provides tangible benefits mainly the very low computational cos
Optimization of maintenance intervals preventive and repair of gas turbines. Case of Algerian gas pipelines
No full textA new method based on fast kurtogram for the identification of pitting fault versus crack fault in gearbox systems
No full textExperimental study of sandwich multilayer reinforced by glass fibre and agglomerated cork
Get PDFThis paper presents an experimental study which is determined the mechanical properties of a composite material sandwich multilayer developed in the laboratory of mechanics of materials and composites, Materials Research Unit, process and en¬vironment. This type of sandwich is composed of four layers laminated based on an epoxy resin reinforced by woven glass fibres and mast between which three plates of agglomerated cork with stacked alternately laminated layers. Specimens for bending tests three and four points were prepared from the multilayer sandwich panels. A first series of static three-point bending tests shows a clear difference in the fracture behaviour for materials, laminate and cork. These materials have undergone a large plastic deformation without rupture achieve full sandwich, with the onset of delamination between layers laminated material and cork. In order to determine the bending stiffness modules D, the shear modulus and flexural N and the shear modulus of the soul Ga, we conducted a second test campaign four points bending. As a result, we can develop a variety of white cork produced in Algeria in order to use it in the construction and automotive industrie
التمكين الإداري وأثره على الأداء الوظيفي : دراسة حالة مؤسسة MGB ROYAL (الرغاية)
No full textأثرت البيئة الإقتصادية على إدارة الأعمال مما أدى إلى تزايد أهمية العاملين في المؤسسات ، و بالتالي برزت فكرة التمكين هو نقل السلطات الكافية للعاملين ليتمكنوا من أداء مهامهم دون تدخل مباشر من الإدارة ،مع دعم قدراتهم ومهاراتهم ، وقياس أدائهم الوظيفي بناء على أهداف واضحة ؛ مما يجعلهم مسؤولين عن النتائج بدافع الشراكة في الرؤية ،القيادة و الأهداف ، وبالتالي تحسين الأداء؛ وقد حاولت من خلال هذه الدراسة خوض غمار التمكين و أثره على الأداء الوظيفي ، مع إسقاط ذلك على إحدى المؤسسات الجزائرية ؛ إذ تم تفريغ و تحليل البيانات المحصل عليها من أفراد عينة الدراسة باستخدام برنامج الحزم الإحصائية للعلوم الاجتماعية (SPSS ) ، وتبين من خلال النتائج وجود أثر مرتفع للتمكين الإداري على الأداء الوظيفي . وهذا ما توافق مع نتائج الجانب النظري للدراس
Experimental results of sensorless rotor field oriented control using MRAS
Get PDFThis work deals with design and implementation
of sensorless rotor field oriented control using model reference
adaptive system (MRAS) of induction motor (IM) drives.
SVPWM, using an injected Zero-Sequence Signal (ZSS), is used
for controlling the motor. Proportional Integral Controllers
with antiwindup are designed. A 3Kw, 3-phase, 50Hz, 1420rpm,
induction motor and a dSPACE DS1104 hardware/software are
used to carry out the control application. The experimental
results show the effectiveness and the limitation of the control
metho
Numerical modeling of transients in gas pipeline
Get PDFA set of equations governing an isothermal compressible fluid flow is analytically and numerically analyzed. The obtained equations are written in characteristic from and resolved by a predictorcorrector lambda sceme for the interior mesh points. The method of characteristics (MOC) is used for the boundaries. Advantages of explicit form of these schemes and the flexibility of the MOC are used for an isothermal fast transient gas flow in short pipeline. The results, obtained for a simple practical application agree with those of other method
أثر الإدارة الإلكترونية في تفعيل الخدمة العمومية في الجزائر : دراسة نموذج مؤسسة بريد الجزائر
No full textص. 94- 114إن تطبيق الإدارة الإلكترونية كألية لتفعيل الخدمة العمومية يمثل استراتيجية محورية يمكنها إضفاء نتائج ايجابية على عمل الأجهزة الإدارية الحكومية، ويحقق مقدار من المصداقية في عمل مؤسسات الخدمة العمومية، فالتوجه نحو نشر المعلومات الضرورية أمام طالبي الخدمات، عن طريق خلق مؤسسات عمومية تتصف بالفعالية والكفاءة وتستجيب لإحتياجات المواطني