Target Costing application in Egypt an institutional Perspective

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On the Selection of Simulation Software for Manufacturing Application

The growing complexity of manufacturing along with the need for higher efficiency, greater flexibility, better product quality and lower cost urged the use of simulation in manufacturing systems. The number and variety of simulation software packages on the market increased as well. Consequently, the varieties of these packages led to some bewilderment on the part of potential users when faced the selection process. The present article addresses an overview of material addressed in journals, conferences, and textbooks on the selection of appropriate simulation software. It also suggests a classification of main criteria to be considered in evaluating simulation software packages. Moreover, a checklist of simulation software features with five levels of indication will be included. A proposed methodology has been employed in interpreting the checklist. Finally, future trends towards the provision of more effective selection tools will be discussed

Real Time Optimal Tuning of Quadcopter Attitude Controller Using Particle Swarm Optimization

A real-time novel algorithm for proportional, integral and derivative (PID) controller tuning for quadcopters is introduced. The particle swarm optimization (PSO) method is utilized to search the quadcopter solution space to find the best PID controller parameters. A fuzzy logic (FL) controller is used to provide proper velocity reference signals to serve as tracking set points to be achieved by the PID controller. This nested loop design is proposed for stabilizing the quadcopter, where the fuzzy logic controller (FL) is used in the stable loop (i.e. outer loop) to control the desired angle, while the PID controller is used for the rate loop (i.e. inner loop). Finally, the optimum generated PID parameters were achieved in real time using the PSO search algorithm. The generated parameters were tested successfully using an experimental quadcopter setup at the University of Jordan

Multi-beam fibre-optic laser scanning system for surface defect recognition

Multi-beam scanning systems are being used in automated industrial manufacturing environments to determine surface defects. Recent methods of surface defect detection involve the use of fibre-optic light emitting and detection assemblies. This paper deals with the design and development of a new high-speed photo-electronic system. A line of five emitting diodes and five receiving photodiodes were used as light sources and detectors respectively. These arrays of emitting diodes and photo-detectors were positioned opposite each other. Data capture was controlled and analysed by PC using LabView software. A newly developed technique of using an angled array of fibres allows an adjustable resolution to be obtained with the system, with a maximum system resolution of approximately 100 m (the diameter of the collecting fibre core). This system was successfully used to measure various materials surface profile, surface roughness, thickness, and reflectivity. The advantages of this new system may be seen as lower cost, less bulky, greater resolution and flexibility

Flow Shop Scheduling Problem: a Computational Study

A computational study has been developed to obtain optimal / near optimal solution for the flow shop scheduling problem with make-span minimization as the primary criterion and the minimization of either the mean completion time, total waiting time or total idle time as the secondary criterion. The objective is to determine a sequence of operations in which to process ‘n’ jobs on ‘m’ machines in same order (flow shop environment) where skipping is allowed. The Simulation approach for deterministic and stochastic flow shop scheduling has been developed. It reads and manipulates data for 500 jobs on 500 machines. Different factorial experiments present a comparative study on the performance of different dispatching rules, such as FCFS, SPT, LPT, SRPT and LRPT with respect to the objectives of minimizing makespan, mean flow time, waiting time of jobs, and idle time of machines. The proposed model is evaluated and found to be relatively more effective in finding optimal/ near optimal solutions in many cases. The influence of the problem size in computational time for this model is discussed and recommendations for further research are presented

Job Shop Scheduling Problem: an Overview

The Job-shop scheduling is one of the most important industrial activities, especially in manufacturing planning. The problem complexity has increased along with the increase in the complexity of operations and product-mix. To solve this problem, numerous approaches have been developed incorporating discrete event simulation methodology. The scope and the purpose of this paper is to present a survey which covers most of the solving techniques of Job Shop Scheduling (JSS) problem. A classification of these techniques has been proposed: Traditional Techniques and Advanced Techniques. The traditional techniques to solve JSS could not fully satisfy the global competition and rapidly changing in customer requirements. Simulation and Artificial Intelligence (AI) have proven to be excellent strategic tool for scheduling problems in general and JSS in particular. The paper defined some AI techniques used by manufacturing systems. Finally, the future trends are proposed briefly

Democracy in the Eye of the Beholder: A Cross-National Study Examining the Influence of Individualism on Perceptions of Democratic Ideals

Although research shows widespread global support for democracy, research suggests that there are different national perceptions of democracy based on exposure to democracy, political regimes, and national income. However, the research on how national culture affects perceptions and definitions of democracy is limited. A well-studied and defined cultural divide is between collectivist and individualist cultures. Consequently, there is research that explores the differences in how democracy develops and manifests in collectivist and individualist cultures, as well as the correlation between the level of individualism in a country and its national wealth. However, there is a gap in the research on how a culture of individualism in a country affects how its population defines democracy. In this study, I measure the relationship between individualism level in a country and the average response on the essentialness of various attributes of democracy. I find some substantial evidence that countries with higher national individualism scores perceive characteristics of democracy as essential differently than other countries. These results could potentially indicate that culture may play a significant role in formulating ideals and standards in a country that affects definitions and perception of democracy.Bachelor of Art

Dibromido(2,3,9,10-tetra­methyl-1,4,8,11-tetra­azacyclo­tetra­deca-1,3,8,10-tetra­ene)cobalt(III) bromide

In the title compound, [CoBr2(C14H24N4)]·Br, the CoIII ion is located on an inversion centre and possesses a distorted octa­hedral coordination geometry in which four nitro­gen donors of the ligand mol­ecule are in the equatorial plane and two Br− ions occupy both the axial sites to give a trans isomer. The Br- counter- anion is also located on an inversion centre

4-[(3-Formyl-4-hydroxy­phen­yl)diazen­yl]-N-(pyrimidin-2-yl)benzene­sulfonamide

The title mol­ecule, C17H13N5O4S, has a trans configuration with respect to the diazenyl (azo) group. The pyrimidine ring and the terminal benzene ring are inclined at angles of 89.38 (4) and 1.6 (6)°, respectively, with respect to the central benzene ring. The conformation of the mol­ecule is in part stabilized by an intra­molecular O—H⋯O hydrogen bond. In the crystal structure, mol­ecules related through inversion centers form hydrogen-bonded dimers involving the sulfon­amide N—H group and the N atom of the pyrimidine ring

Corrosion Control of Mg-Zn Implant Alloys in Simulated Body Fluid

Magnesium alloys have recently attracted the attention as a new biodegradable material.  In this study, Mg-Zn alloys (1-4wt.% Zn) were fabricated with high purity raw materials using a clean melting process (fluxless method) and a protective atmosphere of CO2 + 0.4 SF6. The as-cast microstructures of the investigated alloys were characterized by optical and scanning electron microscopes, EDS and XRD. Corrosion properties of the prepared alloys were examined in simulated body fluid (SBF) by electrochemical techniques and immersion test (hydrogen evolution method).  Surface modification of the prepared alloys was performed using micro arc oxidation (MAO) treatment and hydroxiapatite (HA) coating. The results of the as-cast microstructure showed that Zn up to 2 wt% was completely dissolved in a-Mg matrix. On increasing Zn content (> 2wt%) the grain size decreased and a second MgZn2 phase was observed. Corrosion testing results revealed that Mg-1,2,3 wt% Zn have almost the same corrosion rates (0.025 mm/y) whereas Mg-4Zn has the highest degradation rate. Hydroxiapatite (HA) coating on micro-arc oxidation (MAO) treated magnesium alloys formed a dense and compact layer on the surface of magnesium alloys which had greatly improved surface properties and enhanced corrosion resistance of the prepared alloys. Keywords: Mg alloys, implants, biodegradable, corrosion, surface modificatio