K.Kartheek Kumar Naidu, G.Krishna Deekshit |
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| Design and Implementation of New Full-Bridge Single-Stage Converter Topology | ||||||||||||
This paper presents a single-stage circuit topology consisting of the association of a full-bridge isolated dc–dc converter and two input inductors and two input diodes connected to the mains network, in order to obtain an isolated ac/dc switch mode power supply, with sinusoidal input current. The proposed topology does not use an input bridge rectifier, common in similar applications. The current in the two input inductors can therefore, flow in both directions. Consequently, the proposed topology equally distributes the current by the four-bridge transistors that provide four input parallel boost power factor correctors (PFCs). The use of the four-bridge permitting the accurate simultaneous regulation of output voltage and input current is hereby described. The inter-dependency between these two conversion processes is completely analysed, allowing for useful design rules. Simulation results of conventional and proposed single stage converter topology are obtained. A maximum efficiency of 94% was obtained transistors to obtain the PFC function and regulate the output voltage with galvanic isolation is a new technique that makes this topology unique, which also contributes to improve the converter efficiency. Full-bridge converters, input current shaping, low-distortion input current, single-stage power factor correctors (PFCs).
B. Singh, B. N. Singh, A. Chandra, K. Al-Haddad, A. Pandey, and D. P. Kothari, ―A review of single-phase improved power quality AC–DC converters,‖ IEEE Trans. Ind. Electron., vol. 50, no.5, pp. 962–981, Oct. 2003. [2] E. H. Ismail, A. J. Sabzali, and M. A. Al-Saffar, ―Buck-boost-type unity power factor rectifier with extended voltage conversion ratio,‖ IEEE Trans. Power Electron., vol. 55, no. 3, pp. 1123–1132, Mar.2008. [3] M. M. Jovanovi´ and Y. Jang, ―State-of-the-art, single-phase, active power-factor-correction techniques for high-power applications—An overview,‖ IEEE Trans. Ind. Electron., vol. 52, no. 3, pp. 701–708, Jun. 2005. [4] L. Huber, Y. Jang, and M. M. Jovanovic, ―Performance evaluation of bridgeless PFC Boost rectifiers,‖ IEEE Trans. Power Electron., vol. 23,no. 3, pp. 1381–1390, May 2008. [5] Y. Jang and M. M. Jovanovi´, ―A bridgeless PFC boost rectifier with optimized magnetic utilization,‖ IEEE Trans. Power Electron., vol. 24, no. 1, pp. 85–93, Jan. 2009....
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Shamoo K. AL-Hakary, Ahmed Fata Abdurrahman Amedi, Luqman M.S. Dosky |
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Theoretical and Experimental Invistigation of Hollow Cathode Nitrogen Glow Discharge Plasma |
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An experimental investigation of a d.c hollow cathode nitrogen glow discharge has been done at different gas pressure ranged from ( 0.075 to 0.75 ) torr and different radial positions of discharge . Plasma properties were inferred from the current – voltage characteristics of the double probes positioned at different radial space of The discharge, moreover a computer program proposed to determine plasma parameters from the probe characteristics. Furthermore these parameters were calculated using the relation that electron temperature can be written as an explicit function of gas pressure and radius discharge at the Schottky limit. The result exhibits that the measured and calculated electron temperature varies nearly a decreasing exponential with gas pressure as a results of fitting , as well as the variations of both floating and plasma potentials close to the same behavior. On the other hand there is a good agreement between measured and calculated results, these in turn compared with reported works in previous studies and there is a satisfactory agreement.
Hollow Cathode, Glow Discharge Pressure, Plasma Parameters
[1] J. Chen , S .Park , Z. Fan, J.G , Eden and Chang Liu (2002 ) " Development and characteristics of micro machined hollow cathode plasma display devices ", Vol. 11,No. 5 , 536 – 543 .
[2] V.V .Budilov , R.D. Agzamov and K.N. Ramazanov (2007), " ion nitriding in glow discharge with hollow cathode effect ", Metal Science and Heat Treatment , Vol. 49 , No. 7 , 358 – 361 . [3] D. Maric, N. Skoro , G. Malovic, ZLJ. Petrvic,V. Mihailov and R. Djulgerova ( 2009), " Hollow Cathode Discharge : Volt – Amper Characteristics and Space – Time Resolved Structure of Discharge . J. pf Phys :Conference Science 162.1.012007. [4] G.J.M Hagelear , D.B.Mihailova, and J. Van Dijk ( 2010 ) " Analytical Model of a longitudinal Hollow Cathode Discharge ", J.of Phys .D.App,Phys, Vol. 43 , No. 46, 465204.. [5] Eizaldeen F .Kotp and Ashwaq A.Al – Ojeery (2012 )" Studies the Effect of Magnetic Field on Argon Plasma Characteristics", Australian Journal of Basic and Applied Science , 6(3), 817 – 825 .....
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A.Kumar, Dr.G.R.Gurumurthy |
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| Influence of Switching Elements on Harmonics and Power Factor Improvement | ||||||||||||
Increasing demand for electrical energy by utilities has necessitated efficient utilization of available power. Most of the loads in the industry and domestic applications are inductive in nature causing a lagging power factor. This causes a reduction in the utilization of the power input. For the same power input the utilization can be improved by improving the power factor. Further the presence of harmonics results in poor quality of the power leading to losses. . In present days, solid state electronics control electric motors are frequently used for drive control (speed and torque). This can introduce harmonics in current and voltages. The general opinion among technologists is that improvement in power factor reduces losses in an electrical system. Although this is true in a general way, it is not so in systems which use switched electronic devices that can introduce large amount of harmonics [1]. The present work is aimed to study the effect of power factor correction on circuits consisting of power semiconductor switching. Boost convertor supplied from an unregulated supply was considered for the analysis of a static loading. The work also involved study of power factor improvement(PFI) for dynamic load. An automatic power factor controller was designed and implemented induction motor load. The controller was designed to sense the various parameters of the power and calculate the power factor. A rule-based table has been developed based on the power factor input. The controller can sense this power factor and automatically switch ON/OFF appropriate KVAR as per the programmed requirement. The results obtained are comparable with that reported in several previous work done.[1-6] Power factor improvement, Harmonics, THD, APFC, Filters
[1] Francis.M.Fernandez, P.S.Chandramohanan Nair, "Influence of power factor compensating capacitor on estimation of harmonic distortion", 9th International conference on Electrical power quality and utilization" Barcelona, 9-11 October 2007. [5] Fatih Basçiftçi and Ömer Faruk Hatay, "Microcontroller-controlled reactive power measurement and saving circuit design for residences and small scale enterprises", Scientific research and essays Vol 5(16), pp 2312 – 2317, 18-Aug-2010....
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Diji, C.J; Ekpo, D.D; Adadu, C.A |
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| Exergoenvironmental Evaluation of a Cement Manufacturing Process in Nigeria | ||||||||||||
The Cement manufacturing process is an energy intensive and environmentally impacting process. In this study, an exergoenvironmental evaluation is conducted on a wet process, gas – fired 1.3 million tonne capacity cement plant in Nigeria, to assess the ecological impact of its production process by revealing the extent to which each major component of the production process is responsible for the overall environmental impact and identify the sources of the impact. Exergoenvironmental evaluation consists of three major steps. The first step involves a detailed exergy analysis of the production system under consideration using the input – output energy analysis method; in the second step, the required values of the environmental impact are determined by applying the ECO – 99 life cycle assessment method. In the third step the environmental impacts are assigned to the exergy streams in the process. Subsequently, exergoenvironmental variables are calculated and the exergoenvironmental evaluation is carried out. Based on a 70% utilization capacity, embodied energy intensity of 7.07GJ/t and overall exergic efficiency of 0.55; the exergoenvironmental evaluation shows that the major process components impacting the environment were the kiln and limestone extraction processes. The study also showed that exergy destruction occasioned by process and combustion emissions in the kiln is the major source of environmental hazards in the process.With an overall environmental factor of 20.3% for the plant, the study concludes that the environmental hazards are mainly due to system irreversibilities in the process and not the related components environmental factor.
Exergoenvironmental analysis, Cement Manufacturing, Nigeria
[1] Bejan, A; Tsatsaronis, G; Moran, M (1996), Thermal Design and Optimization,Wiley, New York.
[2] Buchgeister, J. (2010) Exergoenvironmental Analysis - A new approach to support [3] Design for environment of chemical processes. Chemical Engineering & Technology, Vol. 33, No. 4, pp. 593-602. [4] Buchgeister, J. (2010) Comparison of Exergoenvironmental Analysis using three Different environmental impact assessment methods in a case of a processof [5] Electricity production. In Proceedings Conference ECOS 2010 as DVD,Lausanne, Switzerland....
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Pavan Kunchur, Prasad Kulkarni, Veeranna Kotagi, |
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| Intelligent Routing and Bandwidth Allocation in Wireless Networks | ||||||||||||
Sensor networks and satellite constellations face a number of challenges for reliable and robust communications. Increasingly heterogeneous nodes and a multitude of new emerging Earth science applications put additional restrictions on throughput and delay requirements. These problems are further aggravated by energy and bandwidth constraints on the network nodes. Quality of service and performance of such wireless networks, in the presence of such issues, are greatly affected by network routing and bandwidth allocation. We propose a new class of routing algorithms based on principles of biological swarms, which have the potential to address these problems in an autonomous and intelligent fashion. Such swarm-based algorithms adapt well to dynamic topologies, and, compared to the current state-of-the-art, have been shown to result in the highest throughput and lowest delays in internet-style networks. Swarm-based routing algorithms boast a number of attractive features, including autonomy, robustness and fault-tolerance. They rely on the interaction of autonomous agents who communicate with each other through the environment (a phenomenon known as stigmergy). Current swarm based routing algorithms focus on wired circuit or packet switched networks. We propose new swarm routing algorithms suitable for wireless sensor or satellite networks. Control for optimizing the transmitter power and data rate for network communication is also considered. Biologically inspired methodologies such as evolutionary computing and particle swarm optimization can be used for concurrent maximization of the data rate and minimization of transmitter power, subject to constraints on the bit error rate (BER) at the receiver.
Intelligent Routing and Bandwidth Allocation in Wireless Networks.
[1] E. Bonabeau, M. Dorigo, and G. Théraulaz, Swarm intelligence: from natural to artificial systems, Oxford University Press, 1999.
[2] M. Dorigo, V. Maniezzo, and A. Colorni, "The ant system: optimization by a colony of cooperating agents," IEEE Transactions on Systems, Man, and Cybernetics, part B, vol. 26, no. 1, pp. 29-41, 1996. [3] R. Schoonderwoerd, O. Holland, J. Bruten and L. Rothkrantz. "Ant-based Load Balancing in Telecommunication Networks," Adaptive Behavior, vol. 5, pp. 169-207, 1996. [4] S. Guerin, "Optimisation multi-agents en environnement dynamique [5] application au routage dans les reseaux de telecommunications," DEA Dissertation, University of Rennes I, France, 1997....
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Dr.Sanjar Salajegheh, Nasrin Pirmoradi |
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| Social Capital of the Organization | ||||||||||||
Social capital is a new concept playing a more important role in organizations and societies than human and physical capital. Nowadays, this concept is being used extensively in sociology and economics, and even recently in management and organization. The concept of social capital indicates linkage and communication between members of a network and causes the goals of the members to be met, creating norms and mutual trust. Social capital is considered as a new concept which, as compared with the human or physical capitals, is of more significance within different organizations. On the other hand the social capital is one of the new concepts which is playing more important role in every organization or society as compared with the human and physical capitals. Today, in the fields of sociology and economy and recently the organizational management concept of the social capital is widely utilized. The concept of the social capital in fact refers to the bindings and relationships between members of a network as a valuable source which by creating norms and mutual trust will prepare the ground for achievements of all objectives desired by the members of every organization. In absence of the social capital other capitals will lose their effectiveness and the march towards development and cultural and economic evolution becomes more difficult and risky. The social capital, can give us a new impression of the socio-economic systems assisting the managers in better management of their systems and organizations whether at macro management level or within small organizations and corporations.
social capital, organizational social capital, Management, Organization, Performance
[1] Ancona, Deborah G. and David F. Caldwell. (1992). ―Bridging the Boundary: External Activity and Performance in Organizational Teams‖, Administrative Science Quarterly, 37: 634-665.
[2] Amirkhani, T., &Poorezzat, A.A. (2009). Reflection on development of social capital in the light of organizational justice.Journal of Public Administration, 1(1), 20. [In Persian]. [3] Adler, Paul S, and Seok-Woo Kwon. (2002). ―Social Capital: Prospects for a New Concept.‖ Academy of Management. The Academy of Management Review 27: 17-40. [4] 4-Adler, P., & Kwon, S. (2000). Social capital: The good, the bad and the ugly. In E. Lesser (Ed.). Knowledge and Social Capital: Foundations and Applications. Butterworth-Heinemann. [5] Adam, Frane, and BorutRoncevic. (2003). ‗Social Capital: Recent Debates and Research Trends.' Social Science Information 42: 155-183.....
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Japneet Kaur, Ramanpreet Kaur |
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| Optimal Palette Generation Using Trained Neural Network Approach (TNN) | ||||||||||||
Color is the most important properties for object discrimination. It is an object component that adds a new dimension to the machine vision. The color images on low devices are displayed having limited number of colors called as color palette reduction to cut down the storage requirements. In this paper we investigate the problem of averaging aggregation functions to select the appropriate function using neural network to reduce the color of an image. The neural network represents the large set of input features with a smaller set of rules to predict the exact penalty of the aggregation function to have good approximation. Then train the neural network with the image samples so that it creates the set of rules to predict the color values using aggregation functions as the features and it comes to an end with some experimental results and conclusions.
color reduction, color palette, neural networks, neural network learning, network training
[1] Nikos Papamarkos, Antonis E. Atsalakis and Charalampos P. Strouthopoulos ―Adaptive Color Reduction‖ 2002 IEEE
[2] Guojian Cheng, Jinquan Yang, Kuisheng Wang, Xiaoxiao Wang ―Image Color Reduction based on Self-organizing Maps and Growing Self-Organizing Neural Networks‖ 2006 IEEE [3] Max Mignotte ―A Bicriteria-Optimization-Approach-Based Dimensionality-Reduction Model for the Color Display of Hyperspectral Images‖ 2012 IEEE [4] Feng Xiao , Mingquan Zhou , Guohua Geng ―Detail Enhancement and Noise Reduction with True Color Image Edge Detection‖ 2011 IEEE [5] Gleb Beliakov, Humbeto Bustince and Daniel Paternain ―Image Reduction Using Means on Discrete Product Lattices‖2011 IEEE....
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