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SIMULATION MODELING OF AUTOMATIC PRODUCTION LINES WITH INTERMEDIATE BUFFERS

Research Abstract
A production line is an important class of manufacturing system when large quantities of identical or similar products are to be produced. The performance of a production line is highly influenced by machine failures. When a machine fails, it is then be unavailable during a certain amount of time required to repair it. Analysis of production lines divides into three types: analytical, approximation and simulation models. The analytical and approximation models have assumptions, which make these models unrealistic such as reliable workstations, certain processing distribution, the first workstation cannot be starved and the last workstation cannot be blocked. The main problems in production lines treatment are the calculation of throughput and average levels of buffers because of the great size of state space. An analytical model is reviewed to clarify the limitations to use such treatment in real production lines. Simulation modeling of production lines is considered very important for designers interested in: Workload Allocation Problem (WAP), Server Allocation Problem (SAP), and Buffer Allocation Problem (BAP). This paper studies and analyzes the performance keys, which effect on production lines. A simulation model is developed by using ARENA software and used to analyze and test several bottlenecks that are causing severe congestions in different areas on the production line and could resolve all of these bottlenecks. In this paper, an actual cement production line is used as a case study. After a simulation time of 13 days, a simulation results show the line bottlenecks, workstations utilization, buffer capacities and the line production rate. The outputs clarify redesign of allocation of buffers, which verify an optimum size could be made; it might be taken into consideration when designers implement such lines. Finally modified better workstations utilization, buffer capacities and the line production rate with an increase about 15% of the production rate and economizing of 37 % from buffer capacities.
Research Authors
M. Heshmat, Mahmoud A. El-Sharief and M. G. El-Sebaie
Research Journal
Journal of Engineering Sciences, Assiut University, Faculty of Engineering
Research Pages
2175 -2189
Research Rank
2
Research Vol
41-6
Research Year
2013

SIMULATION MODELING OF AUTOMATIC PRODUCTION LINES WITH INTERMEDIATE BUFFERS

Research Abstract
A production line is an important class of manufacturing system when large quantities of identical or similar products are to be produced. The performance of a production line is highly influenced by machine failures. When a machine fails, it is then be unavailable during a certain amount of time required to repair it. Analysis of production lines divides into three types: analytical, approximation and simulation models. The analytical and approximation models have assumptions, which make these models unrealistic such as reliable workstations, certain processing distribution, the first workstation cannot be starved and the last workstation cannot be blocked. The main problems in production lines treatment are the calculation of throughput and average levels of buffers because of the great size of state space. An analytical model is reviewed to clarify the limitations to use such treatment in real production lines. Simulation modeling of production lines is considered very important for designers interested in: Workload Allocation Problem (WAP), Server Allocation Problem (SAP), and Buffer Allocation Problem (BAP). This paper studies and analyzes the performance keys, which effect on production lines. A simulation model is developed by using ARENA software and used to analyze and test several bottlenecks that are causing severe congestions in different areas on the production line and could resolve all of these bottlenecks. In this paper, an actual cement production line is used as a case study. After a simulation time of 13 days, a simulation results show the line bottlenecks, workstations utilization, buffer capacities and the line production rate. The outputs clarify redesign of allocation of buffers, which verify an optimum size could be made; it might be taken into consideration when designers implement such lines. Finally modified better workstations utilization, buffer capacities and the line production rate with an increase about 15% of the production rate and economizing of 37 % from buffer capacities.
Research Authors
M. Heshmat, Mahmoud A. El-Sharief and M. G. El-Sebaie
Research Journal
Journal of Engineering Sciences, Assiut University, Faculty of Engineering
Research Pages
2175 -2189
Research Rank
2
Research Vol
41-6
Research Year
2013

NATURAL CONVECTION HEAT TRANSFER INSIDE VERTICAL AND
INCLINED OPEN ENDED EQUILATERAL TRIANGULAR CHANNELS

Research Abstract
Experimental study of natural convection heat transfer inside smooth and rough surfaces of vertical and inclined equilateral triangular channels of different inclination angles with a uniformly heated surface are performed. The inclination angle is changed from 15º to 90º. Smooth and rough surface of average roughness (0.02mm) are used and their effect on the heat transfer characteristics are studied. The local and average heat transfer coefficients and Nusselt number are obtained for smooth and rough channels at different heat flux values, different inclination angles and different Rayleigh numbers (Ra) 6.48 × 105 ≤ Ra ≤ 4.78 × 106 . The results show that the local Nusselt number decreases with increase of axial distance from the lower end of the triangular channel to a point near the upper end of channel, and then, it slightly increases. Higher values of local Nusselt number for rough channel along the axial distance compared with the smooth channel. The average Nusselt number of rough channel is higher than that of smooth channel by about 8.1% for inclined case at θ = 45o and 10% for vertical case. The results obtained are correlated using dimensionless groups for both rough and smooth surfaces of the inclined and vertical triangular channels.
Research Authors
Mahmoud S. Ahmed, Hany A. Mohamed, Mohamed A. Omara, and Mohamed F. Abdeen
Research Journal
Journal of Engineering Sciences, Assiut University, Faculty of Engineering
Research Pages
2160 - 2174
Research Rank
2
Research Vol
41-6
Research Year
2013

DESIGN AND SIMULATION OF SHUNT ACTIVE POWER FILTER FOR ASSIUT CEMENT COMPANY DC MOTOR DRIVE

Research Abstract
This paper introduces a design and simulation of an adaptive shunt active power filter (APF) for harmonic mitigation and power factor (PF) correction of 630 kW DC motor (DCM) drive (called By Pass Motor Fan in production line # 2 in Assiut cement company). Due to the presence of power thyristor converters, a very bad PF and different harmonic components exist in the system, especially in the input current to the DCM drive. All measurements needed for complete analysis at the Medium Voltage (MV) supply source side and at Low Voltage (LV) motor drive side are performed using professional power quality (PQ) analysers and their associated software programs. The studied system is modelled and simulated using MATLAB Simulink software. The instantaneous active and reactive current components id and iq control method is used in this study to drive the shunt active filter. Therefore the harmonic contents at MV supply source and at point of common coupling (PCC) with the DCM drive are reduced to the standard values. Both digital simulation and practical measurements are presented and consistent. The results show that a good dynamic and steady-state performance of the system is achieved
Research Authors
Gaber EL-Saady, EL-Noby A. Ibrahim and Mohamed Amin
Research Department
Research Journal
Journal of Engineering Sciences, Assiut University, Faculty of Engineering
Research Pages
2244 - 2259
Research Rank
2
Research Vol
41-6
Research Year
2013

DESIGN AND SIMULATION OF SHUNT ACTIVE POWER FILTER FOR ASSIUT CEMENT COMPANY DC MOTOR DRIVE

Research Abstract
This paper introduces a design and simulation of an adaptive shunt active power filter (APF) for harmonic mitigation and power factor (PF) correction of 630 kW DC motor (DCM) drive (called By Pass Motor Fan in production line # 2 in Assiut cement company). Due to the presence of power thyristor converters, a very bad PF and different harmonic components exist in the system, especially in the input current to the DCM drive. All measurements needed for complete analysis at the Medium Voltage (MV) supply source side and at Low Voltage (LV) motor drive side are performed using professional power quality (PQ) analysers and their associated software programs. The studied system is modelled and simulated using MATLAB Simulink software. The instantaneous active and reactive current components id and iq control method is used in this study to drive the shunt active filter. Therefore the harmonic contents at MV supply source and at point of common coupling (PCC) with the DCM drive are reduced to the standard values. Both digital simulation and practical measurements are presented and consistent. The results show that a good dynamic and steady-state performance of the system is achieved
Research Authors
Gaber EL-Saady, EL-Noby A. Ibrahim and Mohamed Amin
Research Department
Research Journal
Journal of Engineering Sciences, Assiut University, Faculty of Engineering
Research Pages
2244 - 2259
Research Rank
2
Research Vol
41-6
Research Year
2013

DESIGN AND SIMULATION OF SHUNT ACTIVE POWER FILTER FOR ASSIUT CEMENT COMPANY DC MOTOR DRIVE

Research Abstract
This paper introduces a design and simulation of an adaptive shunt active power filter (APF) for harmonic mitigation and power factor (PF) correction of 630 kW DC motor (DCM) drive (called By Pass Motor Fan in production line # 2 in Assiut cement company). Due to the presence of power thyristor converters, a very bad PF and different harmonic components exist in the system, especially in the input current to the DCM drive. All measurements needed for complete analysis at the Medium Voltage (MV) supply source side and at Low Voltage (LV) motor drive side are performed using professional power quality (PQ) analysers and their associated software programs. The studied system is modelled and simulated using MATLAB Simulink software. The instantaneous active and reactive current components id and iq control method is used in this study to drive the shunt active filter. Therefore the harmonic contents at MV supply source and at point of common coupling (PCC) with the DCM drive are reduced to the standard values. Both digital simulation and practical measurements are presented and consistent. The results show that a good dynamic and steady-state performance of the system is achieved
Research Authors
Gaber EL-Saady, EL-Noby A. Ibrahim and Mohamed Amin
Research Department
Research Journal
Journal of Engineering Sciences, Assiut University, Faculty of Engineering
Research Member
Research Pages
2244 - 2259
Research Rank
2
Research Vol
41-6
Research Year
2013

A New ECG Compression Algorithm Based On Wavelet Foveation And Huffman Coding Techniques

Research Abstract
This paper introduces a new ECG signal compression algorithm based on modulating the ECG signal DWT coefficients with a proper mask constructed using the foveation principle. The constructed mask is a selective mask that gives a high resolution at a certain point (fovea) and falls down away from this point. The wavelet foveation of the ECG signal leads to decreasing the amount of information contained in the signal. So, the value of the foveated ECG signal Entropy will be decreased which by turn will increase the Compression Ratio (CR).The ECG signal after wavelet foveation is coded using Huffman codes; namely optimal selective Huffman coding, adaptive Huffman coding and modified adaptive Huffman coding. The performance of each coding technique is measured based on the CR, time cost and computational complexity.
Research Authors
Mohammed Abo-Zahhad, Sabah M. Ahmed and Ahmed Zakaria
Research Department
Research Journal
Journal of Engineering Sciences, Assiut University, Faculty of Engineering
Research Member
Research Pages
2213 - 2230
Research Rank
2
Research Vol
41-6
Research Year
2013

A New ECG Compression Algorithm Based On Wavelet Foveation And Huffman Coding Techniques

Research Abstract
This paper introduces a new ECG signal compression algorithm based on modulating the ECG signal DWT coefficients with a proper mask constructed using the foveation principle. The constructed mask is a selective mask that gives a high resolution at a certain point (fovea) and falls down away from this point. The wavelet foveation of the ECG signal leads to decreasing the amount of information contained in the signal. So, the value of the foveated ECG signal Entropy will be decreased which by turn will increase the Compression Ratio (CR).The ECG signal after wavelet foveation is coded using Huffman codes; namely optimal selective Huffman coding, adaptive Huffman coding and modified adaptive Huffman coding. The performance of each coding technique is measured based on the CR, time cost and computational complexity.
Research Authors
Mohammed Abo-Zahhad, Sabah M. Ahmed and Ahmed Zakaria
Research Department
Research Journal
Journal of Engineering Sciences, Assiut University, Faculty of Engineering
Research Member
Mohammed Abo Zahhad
Research Pages
2213 - 2230
Research Rank
2
Research Vol
41-6
Research Year
2013

THE OPTIMUM AIRPORT RUNWAY ORIENTATIONFOR DIFFERENT REGIONS IN EGYPT

Research Abstract
This study investigates wind analysis which is conducted by manual analysis and computer analysis for airports outside population settlements. The accuracy of used software in computer analysis was checked by comparing their results with the manual procedure. The manual analysis represented by windrose type II while the computer analysis represented by two software the Federal Aviation Administration (FAA) Airport design and windrose PRO. Wind patterns of twenty regions in Egypt are examined by WORPLOT View and FAA Airport Design program to estimate the best runway orientation. These twenty regions have thirteen regions with existing airports and seven regions of bearable airports. After examining Egyptian surface wind pattern found that the optimum solution for the most of Egypt regions is one direction while there are two directions for Mersa Matruh and Port Said. The existing runways in Assiut airport and Port Said airport have not fulfill standard requirement which were taken in this study (wind coverage and cross wind rules) throughout the year. Runway orientation was found for previousexamined airports. Three runway orientations had been studied with more details, Aswan, Marsa Alam and Al Nozha airports.There is one proposed runway in Al Nozha airport, which have fulfilled standard requirement throughout the year instead of the existing runways. Aswan and Marsa Alam existing runways were accepted.
Research Authors
El-Sayed Mohamed Abdalla1, Mahmoud Enieb Osman and Ramy Nasr Abd El-monem Mohamed3
Research Department
Research Journal
Journal of Engineering Sciences, Assiut University, Faculty of Engineering
Research Pages
2126 - 2139
Research Rank
2
Research Vol
41-6
Research Year
2013

EFFECT OF FIBERS TYPE ON FLEXURAL BEHAVIOR OF HIGH
PERFORMANCE CONCRETE BEAMS UNDER REPEATED LOAD

Research Abstract
The need of high performance concrete HPC is increasing in the recent years. This material becomes necessary, but it is brittle. So, fibers are used to enhance mechanical properties of HPC. The enhanced properties include tensile strength, compressive strength, elastic modulus, crack resistance, crack control, durability, fatigue life, resistance to impact and abrasion, shrinkage, expansion, thermal characteristic, and fire resistance of concrete. The main objective of this research is to study the effect of using Harex, polypropylene and glass fibers on flexural behavior of High performance concrete beams under static and repeated loads.
Research Authors
Aly Abdel Zaher Elsayed, Mohamed M. Rashwan, Hesham Mohamed Diab, Ali Mohamed Abdallah and Abeer Mohamed Nageeb Mohamed
Research Department
Research Journal
Journal of Engineering Sciences, Assiut University, Faculty of Engineering
Research Member
Research Pages
2103 - 2125
Research Rank
2
Research Vol
41-6
Research Year
2013
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