In recent years, the energy efficiency improvement has become significant due to rapid consumption of world's energy resources. Particularly in manufacturing industry, hard turning process is one of the most fundamental metal removal processes that require huge power consumption and it could be improved in term of energy usage by many alternatives. At the same time, the improvement in term of machined surface quality is become a need since it would reflect appearance, performance and reliability of the products. As for example in the CNC machining field, one of the solution for this issue is by increasing the effectiveness of the existing lubrication systems as it could improve the machined surface quality, reduce the power required to overcome the friction component in batch production of machining process and reduce the oil consumption. The effectiveness of the lubrication system could be improved by introducing the nanobase lubrication system for much less power consumption as the rolling action of billions units of nanoparticle in the tool chip interface could reduce the cutting forces significantly. In this research work, the possibility of using SiO2 nanobase lubrication system is investigated to reduce the machining power consumption as well as improving surface quality in hard turning process of AISI4140.

Application of surface modification methods is expected to be a supreme solution to diminishing fretting damage. In this study, our aim was to improve the fretting fatigue life of Al7075-T6 alloy by covering it with a TiN thin film hard coating using the magnetron sputtering technique. Coated specimens with the best surface hardness, adhesion strength and roughness were tested with a rotating bending fatigue test machine. The fatigue results indicate that fretting was significantly detrimental and reduced the fatigue life of uncoated specimens, while a slighter decrease was observed for coated samples with high surface hardness and adhesion. The fretting fatigue lives of coated specimens with high surface hardness and adhesion strength improved 61% and 16% at high bending stress and 39% and 77% at low bending stress, respectively, in comparison to the uncoated specimens. In addition, the lowest surface roughness resulting from thin film TiN coating improved the fretting fatigue life of specimens by 18% at low cyclic fatigue, while at high cyclic fatigue the result was reversed.

The maximum a posterior (MAP) decoding scheme is presented here for cooperative communication networks that adopt the parity forwarding as a cooperation protocol. The MAP decoder is optimal in the sense that it minimises the error probability. The authors consider a wireless network that is composed of two sources: two relays and a single destination. A closed-form expression is derived for upper bound on the bit error probability. The complexity of derivation comes from the fact that although the source generates data with equal probability, the data received at the destination does not have the same a priori probability. That is because of the error that occurs in the source-to-relay link. Therefore, the MAP decoding rule cannot be simplified to the maximum likelihood decoding rule. The results show that the analytical upper bound is very tight and almost coincides with the exact error probability obtained from simulations at higher values of the signal-to-noise ratio. Accordingly, the closed-form expression of the upper bound can be used to fully study and understand the diversity performance of the system.

We consider a multiple access relay network where multiple sources send independent data to a single destination through multiple relays, which may inject falsified data into the network. To detect the malicious relays and discard (erase) data from them, tracing bits are embedded in the information data at each source node. In addition, parity bits are added to correct the errors caused by fading and noise. When the total amount of redundancy, tracing bits plus parity bits, is fixed, an increase in parity bits to increase the reliability requires a decrease in tracing bits, which leads to a less accurate detection of malicious behavior of relays, and vice versa. We investigate the tradeoff between the tracing bits and the parity bits in minimizing the probability of decoding error and maximizing the throughput in multisource, multirelay networks under falsified data injection attacks. The energy and throughput gains provided by the optimal allocation of redundancy and the tradeoff between reliability and security are analyzed.

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.

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.

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.

Modeling and simulation of production lines is considered to be important for designers who are interested in: Work-load Allocation Problem (WAP), Server Allocation Problem(SAP), and Buffer Allocation Problem (BAP). This paper studies and analyzes a real cement production line as a case study. A simulation model is developed by 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. Workstation failure data is collected along one year to obtain the machines failure behaviors. This paper searches for the optimum buffer sizes with the increase of the production rate. An actual cement production line is studied and analyzed by the simulation model from stem to stern. After a simulation replication time of 12 days,a simulation results show the line bottlenecks, workstations utilization, buffer capacities and the line production rate. To resolve the bottlenecks, a redesign of allocation of buffers which verify anoptimum size could be made and it might be taken into consideration when designers implement this line. Finally modified optimum workstations utilization, buffer capacities and the line production rate with an increase about more than 15% of the production rate and economizing of 34 % of buffer capacities. تعتبر النمذجة والمحاكاة لخطوط الإنتاج مهمة للمصممين المهتمين بمشكلة توزيع عبء العمل (WAP) ومشكلة تخصيص الخادم ((SAP ومشكلة تخصيص المخزن المؤقت (BAP). هذا البحث يدرس ويحلل خطاً موجوداً على أرض الواقع لإنتاج الأسمنت. ببناء نموذج محاكاة باستخدام أحد برامج المحاكاة (ARENA) يتم تحليل واختبار العديد من الاختناقات التي تتسبب في الازدحام الشديد في مناطق مختلفة على خط الإنتاج ويمكن حل جميع هذه الاختناقات. يتم جمع البيانات اللازمة للحصول على سلوك كل عطل من أعطال الماكينات على امتداد سنة كاملة. فى هذا البحث يتم الحصول على الأحجام المثلى للمخازن البينية مع زيادة معدل الإنتاج. بدراسة وتحليل خط الإنتاج من البداية للنهاية وتشغيل نموذج المحاكاة لمدة 12 يوماً تظهر نتائج محاكاة الاختناقات الموجودة بالخط وكذلك طبوغرافية محطات العمل وقدرات المخزن المؤقت ومعدل الإنتاج. يمكن أن يتم إعادة تصميم لحجم المخازن المؤقتة التي تحقق حجماً أمثل لحل الاختناقات، وقد تؤخذ هذه الاعتبارات عند مصممى مثل هذه الأنواع من الخطوط أو إجراء تعديلات على خط الإنتاج للاستفادة المثلى من محطات العمل وقدرات المخزن المؤقت. وأخيراً تم الحصول على زيادة فى الإنتاجية أكثر من 15% وترشيد 34 % من مساحة المخزن المؤقت.

Modeling and simulation of production lines is considered to be important for designers who are interested in: Work-load Allocation Problem (WAP), Server Allocation Problem(SAP), and Buffer Allocation Problem (BAP). This paper studies and analyzes a real cement production line as a case study. A simulation model is developed by 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. Workstation failure data is collected along one year to obtain the machines failure behaviors. This paper searches for the optimum buffer sizes with the increase of the production rate. An actual cement production line is studied and analyzed by the simulation model from stem to stern. After a simulation replication time of 12 days,a simulation results show the line bottlenecks, workstations utilization, buffer capacities and the line production rate. To resolve the bottlenecks, a redesign of allocation of buffers which verify anoptimum size could be made and it might be taken into consideration when designers implement this line. Finally modified optimum workstations utilization, buffer capacities and the line production rate with an increase about more than 15% of the production rate and economizing of 34 % of buffer capacities. تعتبر النمذجة والمحاكاة لخطوط الإنتاج مهمة للمصممين المهتمين بمشكلة توزيع عبء العمل (WAP) ومشكلة تخصيص الخادم ((SAP ومشكلة تخصيص المخزن المؤقت (BAP). هذا البحث يدرس ويحلل خطاً موجوداً على أرض الواقع لإنتاج الأسمنت. ببناء نموذج محاكاة باستخدام أحد برامج المحاكاة (ARENA) يتم تحليل واختبار العديد من الاختناقات التي تتسبب في الازدحام الشديد في مناطق مختلفة على خط الإنتاج ويمكن حل جميع هذه الاختناقات. يتم جمع البيانات اللازمة للحصول على سلوك كل عطل من أعطال الماكينات على امتداد سنة كاملة. فى هذا البحث يتم الحصول على الأحجام المثلى للمخازن البينية مع زيادة معدل الإنتاج. بدراسة وتحليل خط الإنتاج من البداية للنهاية وتشغيل نموذج المحاكاة لمدة 12 يوماً تظهر نتائج محاكاة الاختناقات الموجودة بالخط وكذلك طبوغرافية محطات العمل وقدرات المخزن المؤقت ومعدل الإنتاج. يمكن أن يتم إعادة تصميم لحجم المخازن المؤقتة التي تحقق حجماً أمثل لحل الاختناقات، وقد تؤخذ هذه الاعتبارات عند مصممى مثل هذه الأنواع من الخطوط أو إجراء تعديلات على خط الإنتاج للاستفادة المثلى من محطات العمل وقدرات المخزن المؤقت. وأخيراً تم الحصول على زيادة فى الإنتاجية أكثر من 15% وترشيد 34 % من مساحة المخزن المؤقت.

Modeling and simulation of production lines is considered to be important for designers who are interested in: Work-load Allocation Problem (WAP), Server Allocation Problem(SAP), and Buffer Allocation Problem (BAP). This paper studies and analyzes a real cement production line as a case study. A simulation model is developed by 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. Workstation failure data is collected along one year to obtain the machines failure behaviors. This paper searches for the optimum buffer sizes with the increase of the production rate. An actual cement production line is studied and analyzed by the simulation model from stem to stern. After a simulation replication time of 12 days,a simulation results show the line bottlenecks, workstations utilization, buffer capacities and the line production rate. To resolve the bottlenecks, a redesign of allocation of buffers which verify anoptimum size could be made and it might be taken into consideration when designers implement this line. Finally modified optimum workstations utilization, buffer capacities and the line production rate with an increase about more than 15% of the production rate and economizing of 34 % of buffer capacities. تعتبر النمذجة والمحاكاة لخطوط الإنتاج مهمة للمصممين المهتمين بمشكلة توزيع عبء العمل (WAP) ومشكلة تخصيص الخادم ((SAP ومشكلة تخصيص المخزن المؤقت (BAP). هذا البحث يدرس ويحلل خطاً موجوداً على أرض الواقع لإنتاج الأسمنت. ببناء نموذج محاكاة باستخدام أحد برامج المحاكاة (ARENA) يتم تحليل واختبار العديد من الاختناقات التي تتسبب في الازدحام الشديد في مناطق مختلفة على خط الإنتاج ويمكن حل جميع هذه الاختناقات. يتم جمع البيانات اللازمة للحصول على سلوك كل عطل من أعطال الماكينات على امتداد سنة كاملة. فى هذا البحث يتم الحصول على الأحجام المثلى للمخازن البينية مع زيادة معدل الإنتاج. بدراسة وتحليل خط الإنتاج من البداية للنهاية وتشغيل نموذج المحاكاة لمدة 12 يوماً تظهر نتائج محاكاة الاختناقات الموجودة بالخط وكذلك طبوغرافية محطات العمل وقدرات المخزن المؤقت ومعدل الإنتاج. يمكن أن يتم إعادة تصميم لحجم المخازن المؤقتة التي تحقق حجماً أمثل لحل الاختناقات، وقد تؤخذ هذه الاعتبارات عند مصممى مثل هذه الأنواع من الخطوط أو إجراء تعديلات على خط الإنتاج للاستفادة المثلى من محطات العمل وقدرات المخزن المؤقت. وأخيراً تم الحصول على زيادة فى الإنتاجية أكثر من 15% وترشيد 34 % من مساحة المخزن المؤقت.