Volume 4, Issue 2, February 2013
Simple Adaptive Control for a Flywheel Zero-Bias AMB System
Yong He, Kenzo Nonami and Zengyi Zhang
Chiba University, Chiba, Japan
Department of Electronics and Mechanical Engineering, Chiba University, Chiba, Japan
The active magnetic bearing (AMB)-flywheel system is used as a storage device for electrical energy, it is desirable to minimize the energy required for its stabilization control. We apply an almost strictly positive real (ASPR)-based simple adaptive control (SAC) scheme to an AMB-flywheel energy storage system using the zero-bias current method. Since most practical systems do not satisfy the ASPR condition, the ASPR conditions are the fundamental restrictions for practical applications of the SAC control. The AMB-flywheel is a multiple-input multiple-output (MIMO) system with five degrees of freedom (DOF). We propose a design method for performing ASPR-augmented control for a MIMO AMB-flywheel system with five degrees of freedom; the method uses a parallel feed forward compensator for MIMO SAC. The SAC controller was proposed for application to an AMB-flywheel system and control performance was improved by combining SAC with a D controller. The SAC-D controller is evaluated via simulations and experiments. We present the analysis of the influence of external disturbances from the EV driving on the road about the AMB-flywheel system. The results demonstrate that the SAC controller can stabilize levitation of the AMB system under real disturbance without any touchdown.
— AMB-Flywheel, Simple Adaptive Control (SAC), Magnetic Levitation and Almost Strictly Positive Realness
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Design and Performance Analysis of a 1550nm Al0.09Ga0.38In0.53As/InP MQW VCSEL by Varying Injection Current
Tamal Roy, Avijit Das, Sujan Howlader, Md. Ronok Hasan Rubel and Rinku Basak
American International University-Bangladesh (AIUB), Banani, Dhaka-1213, Bangladesh
The Vertical-Cavity Surface-Emitting Laser (VCSEL) is becoming a key device in high-speed optical local-area networks (LANs) and even wide-area networks (WANs). This device is also enabling ultra parallel data transfer in equipment and computer systems. In this work, the performance characteristics of a designed AlGaInAs/InP based 1550nm multiple quantum well (MQW) VCSEL have been obtained through computations. The obtained characteristics have been analyzed for obtaining better performance. For achieving a superior performance, the concentrations of AlGaInAs QW material have been chosen using the results of other research works. The material gain of a compressive strained Al0.09Ga0.38In0.53As/InP MQW VCSEL has been theoretically computed. Using the peak material gain obtained from this computation the performance characteristics of the designed VCSEL have been obtained. At 300K, the threshold current of the VCSEL has been obtained as 0.61mA. A maximum output power of 2.24mW has been obtained for this designed VCSEL at 6.1mA injection current. Corresponding to the frequency modulation, the maximum resonance frequency has been obtained as 7.7GHz at 6.1mA injection current which indicates high speed performance of the designed VCSEL. By varying injection current the characteristics of designed VCSEL have also been obtained.
— Laser Diode, VCSEL and MQW
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Chatter Stability Boundary Frequencies of a Three Tooth End Milling Process
Ozoegwu C. G., and Omenyi S. N.
Department of Mechanical Engineering, Nnamdi Azikiwe University, PMB 5025, Awka, Nigeria
Stability chart of a three tooth milling process was generated using the Fargue type approximation method and numerically shown to permit only two types of loss of stability which are the secondary Hopf and flip bifurcations. This result is in conformity with theoretical result that has also been validated experimentally thus validating the generated chart. Another contribution of this work is that stability the condition of periodic retarded dynamical systems is established through the use of similarity transformation of second rank tensors. The expressions ‘stability boundary frequencies’ and ‘chatter frequencies’ are used synonymously.
— Stability, Frequencies, Transformation and Three Tooth Milling Process
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Taxonomic Revision of Fumaria Indica (Fumariaceae) from Pakistan
Jehanzeb Khan and Rizwana Aleem Qureshi
Department of Botany Government College Kakki Bannu, Khyber Pakhtunkhwa
Department of Plant Sciences, Quaid-i-Azam University, Islamabad, Pakistan
The available record of the species Fumaria indica
for Pakistan has been revised and updated. The revision has been done in case of nomenclature, local names, specimens examined, flowering and fruiting times, medicinal importance and their geographical distribution.
— Taxonomic Revision, Fumaria, Medicinal Importance and Fumariaceae
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Time Series and Statistical Analysis of Plastic Yield: A Case Study of Finoplastika Industries Ltd, Nigeria
Onyechi Pious Chukwukelue, Ezeliora Chukwuemeka Daniel, Chinwuko Emmanuel Chuka and Aguh Patrick Sunday
Department of Industrial and Production Engineering, Nnamdi Azikiwe University Awka, Anambra State, Nigeria
This work was used to address the problem of time series and statistical analysis of plastic yield on there monthly production in Finoplastika manufacturing industry. Data on production yield were collected from the industry covering a period of three years. Time series technique and statistical tool (method) were applied to precisely determine optimum production yield in the industry. A normality test was used to confirm the adequacy of the models developed. The model was therefore used to suggest optimum monthly production output for different product types investigated. This will prevent the incident of under producing or over producing as identified.
— Forecasting, Time-series, Statistics, Plastic Pipes, 3-D Homogeneity Plot, Normal Probability Plot and Histogram Plot
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Effects of Variation of Quantum Well Number on the Performance of a Designed 635nm Ga0.5In0.5P/(Al0.7Ga0.3)0.5In0.5P Multiple Quantum Well Red Laser
Tawsif Ibne Alam, Md. Abdur Rahim and Rinku Basak
Department of EEE, Faculty of Engineering, American International University-Bangladesh (AIUB), Banani, Dhaka-1213, Bangladesh
In this work, the effects of variation of the number of quantum well on the performance characteristics of a GaInP - based 635nm multiple quantum well (MQW) separate confinement heterostructure (SCH) Red laser have been obtained through computations. The peak material gain of Ga0.5In0.5P/(Al0.5Ga0.5)0.5In0.5P MQW edge emitting laser obtained from the analysis has been used for analyzing the performance characteristics of the designed laser. The number of QW is optimized as 3 for obtaining better performance characteristics where the threshold current of the designed device is 6.7 mA. A maximum output power of 71.18 mW , a maximum resonance frequency of 8.6 GHz and a maximum modulation bandwidth of 13.85 GHz have been obtained for this designed laser at 64 mA injection current at 300K temperature having a 3QW structure.
— Laser Diode, Double-Heterostructure, EEL, QW and Red Laser
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Internet Banking Adoption: An Empirical Study
Ali Saleh Al-Ajam and Khalil Md Nor
Department of Business Administration, Universiti Teknologi Malaysia, Johor, Malaysia
Rejection of Internet banking is one of the most important problems that faces banks in developing countries. So far, very few academic studies have been conducted on internet banking adoption in Arab countries. Hence, this research aims to investigate factors that influence the behavioral intention to use Internet banking in Yemen. Cross-sectional data were collected from 1286 respondents through a survey. Data were then analyzed by structural equation modeling. The findings verified the research hypotheses and confirmed that perceived relative advantages and perceived ease of use, all impact attitude toward the intention of adopting Internet banking. This paper makes a contribution to Internet banking literature by providing insights on the factors that affect Internet banking adoption. The results hint that information about Internet banking services, and its benefits is a critical factor influencing the adoption of Internet banking service. The findings made a contribution in terms of understanding the factors that can contribute to the adoption of Internet banking by Yemeni consumers.
— Internet Banking, Technology Acceptance Model Structural Equation Modeling
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The Introduction of a Covert Channel in Hidden Transportation for Integrity Protocol in Wireless Sensor Networks
Riaz ullah Khan
University of Sunderland, United Kingdom
At the end of 20th century and at the beginning of 21st century Wireless Sensor Networks are widely exercise for the military purposes, industrial purposes as well as for educational purposes. Still Sensors are not yet exercised according to its potential. In these situations the network operator will observe Integrity of the network components, and as a result the problem of trusting the whole system will arise, weather to trust the entire system or not .The issue is that we require a safe, Secure and protected channel among the devices and components for every Integrity protocol. As a result we will propose a Covert channel for hidden transportation of Integrity monitoring messages and this Covert channel will make us able to hide Integrity check messages entrenched within the normal traffic without offering to a malicious node a chance to exercised an Integrity protocol.
— Wireless Sensor Networks, Integrity Protocol and Covert Channel
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Optimization of Process Variables for the Biodephosphorization of Iron ore using Leptospirillum Ferrooxidans
T. O. Chime
An attempt has been made in this study to optimize the processing parameters for the biodephosphorization and bio beneficiation using leptospirillum ferrooxidans. Standard central composite design with 22
full fractional was used to develop the models. The models were optimized using matlab. The surface response of the plots shows that microbial population and leaching time interacted effectively to enhance the degree of biodephosphorization and biobeneficiation. The results show that 92.21% of biodephosphorization was obtained at optimum values of 67 days and 108
microbial population while optimum values of 108
microbial population and 71 days were obtained for 50.98% degree of biobeneficiation.
— Biodephosphorization, Biobeneficiation, Leptospirillum Ferrooxidans and Surface Response
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Moving Average Analysis of Plastic Production Yield in a Manufacturing Industry
Ezeliora Chukwuemeka Daniel, Onyechi Pious Chukwukelue, Chinwuko Emmanuel Chuka and Chukwumuanya Emmanuel Okeychukwu
Department of Industrial and Production Engineering, Nnamdi Azikiwe University Awka, Anambra State, Nigeria
This research work was used to address the problem of Analysis of the forecasting of plastic yield in Finoplastika manufacturing industry. Data on production yield were collected from the industry covering a period of three years. Forecasting based time series technique was applied to determine the optimum production yield in the industry and the behavior of the production system. Hence the model is fit for predicting the product total, since the coefficient of determination shows a strong relationship. The model was therefore used to suggest optimum monthly production output for different product types investigated. This will prevent the incident of under producing or over producing as identified.
— Forecasting, Moving Average and Time-Series
Download full paper PDF format (Page: 65-73)