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Title: Control Using Sliding Mode Of the Magnetic Suspension System
Author(s): Yousfi Khemissi
Pages: 1-5 Paper ID: 102603-7373-IJECS-IJENS Published: June, 2010
Abstract: This paper presents a proposition of sliding mode position controller of the magnetic suspension ball system . The magnetic suspension system (MSS) is a mechatronic system already acknowledged and accepted by the field experts. The design of a controller keeping a steel ball suspended in the air. In the ideal situation, the magnetic force produced by current from an electromagnet will counteract the weight of the steel ball. Nevertheless, the fixed electromagnetic force is very sensitive, and there is noise that creates acceleration forces on the steel ball, causing the ball to move into the unbalanced region. The main function of the sliding mode control (SMC) Controller is to maintain the balance between the magnetic force and the ball's weight. The proposed controller guarantee the asymptotic regulation of the states of the system to their desired values. Complete mathematical models of the electrical, mechanical and magnetic suspension system are also developed. The design and simulations are performed under a Matlab/Simulink models computer package, allows us to examine the performance of this technique: improvement of the stability and the dynamic response.
Keywords: Magnetic suspension system - Sliding Mode Control – Stability and performance - simulation.
Full Text (.pdf)  International Journals Of Engineering and Science | 644 KB
Title: Optimal Reactor Length of an Auto-Thermal Ammonia Synthesis Reactor
Author(s): M. S. M. Ksasy, F. Areed, S. Saraya, Mostafa A. khalik
Pages: 6-11 Paper ID: 101903-2828-IJECS-IJENS Published: June, 2010
Abstract: This paper presents the simulation of auto-thermal ammonia synthesis reactor. Our target here is to estimate the optimal reactor length which will give the maximum profit from the ammonia reactor. There are many literatures which are interested in ammonia simulation in the past but all need some corrections due to either uncorrected model used or uncorrected algorithm. We used here the ODE45 solver of MatLab from Mathworks, along with real-coded genetic algorithm GA and solve for every 0.0001 m from the reactor length. It is found that no spikes, no reverse reaction can take place even at higher top temperature of 800 K. the maximum value of ammonia objective is 5.6635e+006 at optimal reactor length of 6.4253.
Keywords: Ammonia synthesis reactor, Dynamic Mutation, Elitism, Optimization, Real-coded GA.
Full Text (.pdf)  International Journals Of Engineering and Science | 453 KB
Title: Incremental View Maintenance: An Algorithmic Approach
Author(s): Abdulaziz S. Almazyad, Mohammad Khubeb Siddiqui
Pages: 12-17 Paper ID: 101403-5858-IJECS-IJENS Published: June, 2010
Abstract: To maintain the materialized view is one of the crucial tasks in a warehousing environment. The results of incremental computation are affected by interfering updates and compensation is required. The conventional approaches used incremental algorithm causes some anomalies. To solve such anomalies we proposed the novel approach an incremental view maintenance approach by using some existing approach with the use of Version Store and Transaction ID. The information stored in the warehouse is in the form of materialized views. Materialized views are the derived relation, which are stored as the relation in the database, when some updates occur in the parent relation all its child relations also get updated by viewing to maintain the consistency and convergence of the database. In this paper we proposed an algorithm for incremental view maintenance with the inclusion of some existing approaches. We utilized the concept of version store for older versions of tables that have been updated at the source and we are also able to detect the update notification messages that are lost during updating the view. Through the concept of Version store we can retrieve the correct data of corresponding state.
Keywords: Data Warehouse Materialized View, Version Store, Transaction ID, View Manager and View Maintenance.
Full Text (.pdf)  International Journals Of Engineering and Science | 286 KB
Title: Complementary Pass Transistor Control Unit Design for Subthreshold Current Management in Digital Portable Systems
Author(s): R. Sulaiman
Pages: 18-23 Paper ID: 106803-9797-IJECS-IJENS Published: June, 2010
Abstract: Design techniques for low Power dissipation in modern microprocessors, especially in the design of digital portable, notebook, and handheld computers are becoming increasingly important. As technology moves into deep submicron feature sizes, the static or leakage power is expected to increase because of the exponential increase in leakage currents with technology scaling. Within die-process variation is increasing in nanometer technologies, it is observe that leakage power will become comparable to dynamic or total power dissipation in the next generation processors in the next few years. Therefore, it is important for system designers to get an early estimate of leakage power to meet the challenging and methodologies for power dissipation reduction. This paper presents a hardware design and implementation of the complementary pass transistor control unit for microprocessors subthreshold leakage current/power reduction based on dual supply voltage VddL-VddH scaling, and it can be considered as an effective mechanism for reducing processors power and energy while preserving performance by scaling the supply voltage at runtime depending on the workload variation. H-Leakage simulation program is used to verify the theoretical idea and confirm the hardware operations.
Keywords: Complementary pass transistor, Subthreshold leakage current, Dual supply voltage scaling.
Full Text (.pdf)  International Journals Of Engineering and Science | 286 KB
Title: Block Transmission versus Uninterrupted Transmission over Wireless Fading Channels
Author(s): Farid Ghani, Fellow IET, Fellow IETE, Fellow NTF, C. Eng
Pages: 24-28 Paper ID: 103403-5858-IJECS-IJENS Published: June, 2010
Abstract: The paper compares the performance of the Block Linear Equalizer used with the Block Data Transmission System with that of the conventional Linear Transversal Equalizer that is used with an Uninterrupted Continuous System. The result of the comparison show that the Block Data Transmission System has some useful advantages over the Continuous System like exact channel equalization is achieved in all cases and the system is free from error extension effects. The disadvantage of the block Data Transmission System is that for a given information rate the bandwidth required is larger as compared to the continuous systems. This reduces the tolerance to noise of the former systems and partially offsets the advantages gained by the system. However, it is seen that when the number of signals in a group is large as compared to the number of symbols set to zero, the performance of the Block Linear Equalizer is similar to that of the Transversal Equalizer.
Keywords: Linear Transversal Equalizer, Block Detection, Wireless Channel, Inter-symbol Interference.
Full Text (.pdf)  International Journals Of Engineering and Science | 301 KB
Title: Computer Viruses as a Threat to Home Users
Author(s): Waqar Ahmad
Pages: 29-34 Paper ID: 100403-5959-IJECS-IJENS Published: June, 2010
Abstract: The Computer virus threat is growing and home users are threatened by them, especially with the increasing dependence on computers to accomplish the vast verity of tasks in our modern lives. The popularity of internet aggravates the threat and gives the virus writers the ideal environment to distribute their viruses, since computer viruses can spread through the universe in a few hours causing distractions to hundreds of thousands of computers around the globe. An abbreviated idea about computer viruses nature, history and development, the damage caused by some well known viruses and the different types of computer viruses is explained, also virus writers types, motivations, their point of view towards ethical and legal issues, and the effect of legal penalties on their practice is explained .The threat of computer viruses towards home users is proved, some solutions to eliminate the threat of computer viruses is highlighted. Home users can protect their systems based on their understanding of the foregoing.
Keywords: Computer Viruses, Virus Structure
Full Text (.pdf)  International Journals Of Engineering and Science | 149 KB
Title: Traffic Engineering with MPLS for QoS Improvement
Author(s): Adeel Akram, Adeel Ahmed
Pages: 35-38 Paper ID: 102803-5656-IJECS-IJENS Published: June, 2010
Abstract: There can be a lot of QoS parameters that can improved in IP MPLS network Backbone such as bandwidth, CPU utilization, memory requirement, resources distribution and database optimization of each router in the backbone. In this paper, we have optimized database of each router by involving DR/BDR election on each interface so that all involved routers use that elected DR router as to communicate hello packets instead of communicating with all routers and hence database size of each router will remain small and require less memory and CPU utilization over MPLS backbone. Simulation results have been verified using MRTG, Olive/Vmware using conventional IP, MPLS without TE and MPLS using TE capability.
Full Text (.pdf)  International Journals Of Engineering and Science | 371 KB