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Coimbatore, India

Karpagam M.,SKCET | Nagarajan N.,CIET
Journal of Theoretical and Applied Information Technology | Year: 2014

In this paper, we propose a novel bandwidth allocation scheme that will guarantee quality-of-service (QoS) support in the downlink (DL) of a LTE-A system. The proposed scheme is developed based on a queuing model that links important performance metrics of DL service flows of LTE-A systems to a set of tunable parameters. Based on the outcome of the results of the queuing model, the performance metrics are set. The bandwidth allocation scheme then uses the pre-determined performance parameters in making the scheduling decisions. In order to achieve the best results from the proposed scheme, the scheme is integrated with the slot allocation process that is carried out in the physical layer. LTE-A systems uses orthogonal frequency-division multiple access (OFDMA) slot allocation mechanism that adapts to channel conditions at the destination mobile stations (MSs). The proposed scheme performs better than the conventional approach in terms of system throughput, delay and packet dropping ratio, thereby, improving the QoS of the overall system. Further the proposed system is simple in design and its cross-layer approach guarantees improved resource utilization especially in the presence of link adaptations and channel fading. Simulation results have demonstrated that the proposed scheme provides better QoS support for both real-time and non-real-time applications in LTE-A systems. © 2005 - 2014 JATIT & LLS. All rights reserved.

Kousalya G.,SKCET | Palanikkumar D.,Anna University | Piriyankaa P.R.,Anna University
Proceedings - 9th IEEE International Symposium on Parallel and Distributed Processing with Applications Workshops, ISPAW 2011 - ICASE 2011, SGH 2011, GSDP 2011 | Year: 2011

Web services have received much interest to support business-to-business or enterprise application integration but how to combine these services optimally in a continually growing search space is always a challenge. When there are a large number of Web services available, it is not easy to find an execution path of Web services composition that can satisfy the given request, since the search space for such a composition problem is in general exponentially increasing. In this paper, we design a Multi-objective Bees algorithm to solve this optimal service selection optimization problem. Bees algorithm helps to navigate through the whole search space. Web service data can be queried and a new subspace is built for each loop from which feasible solution can be calculated. Though global optimization cannot be guaranteed, an optimal solution can be obtained as a result. © 2011 IEEE.

Karpagam M.,SKCET | Nagarajan N.,CIET | Abiramiathavi J.,SKCET
Journal of Theoretical and Applied Information Technology | Year: 2014

This paper proposes an enhanced error node regaining algorithm to prolong the lifespan of a wireless sensor network when some of the sensor nodes power down. This algorithm is mainly based on the genetic algorithm. The efficiency of the energy can be enhanced by the sparse or compressive sensing feature. Our results show that compact sensing prolongs the network lifespan and is more useful for wireless sensor networks with a smaller coverage area. © 2005 - 2014 JATIT & LLS. All rights reserved.

Dharmalingam S.,Bharat Heavy Electricals Ltd. | Sivakumar L.,SKCET | Umapathy M.,National Institute of Technology Tiruchirappalli
54th ISA POWID Symposium 2011 | Year: 2011

The design and operation of the steam generators supplied to Thermal Power Plants are greatly influenced by the properties of the coal burnt. Unlike other fuels, all coals are not the same and their differences can have significant impacts on a plant's operation. Due to change in the heating value of coal supplied to a steam generator, pressure and temperature of the main steam produced changes. This variation in main steam pressure and temperature can be adjusted to its set value, by the respective control systems. The variation in heating value of coal is random in nature (stochastic). The details on the variation of heating values of coal from all possible mines in India are available. From this, the parameters like mean and standard deviation have been worked out and random numbers representing heating values of coal have been generated. A validated mathematical model for a typical 500 MW unit is initially used for simulation of open loop response with small step change in heating value of coal and the variations in the critical process parameters like main steam pressure and temperature have been evaluated. Then the same model has been applied to evaluate the change in the main steam flow, pressure and temperature for the random variation of the heating values of coal obtained. Subsequently, simulation was done for step variation in heating value of coal by automatically modifying the gains of all controllers based on the correction factor obtained from an embedded controller. This paper discusses on the improved method of ensuring optimum boiler performance during coal fuel switching. Copyright 2011 ISA. All Rights Reserved.

Karpagam M.,SKCET | Nagarajan N.,CIET | Vijaipriya K.,SKCET
Journal of Theoretical and Applied Information Technology | Year: 2014

One of the main challenges of wireless sensor network is maximization of the lifetime of the sensor node since the energy efficiency determines the lifetime of a sensor node, power consumption of the sensing device should be minimized. To conserve power, sensor node should shut off the power supply when not in use. In this paper, we present some energy efficient algorithms to enhance the network lifetime. By introducing sink mobility into wireless sensor networks, the network performance including lifetime, energy efficiency and end-to-end delay can be enhanced. Further, by increasing the number of sleep nodes using smack sets, the network performance can be greatly improved. The Energy-efficient Fixed-sink Clustering Algorithm (EFCA) and Energy-efficient Mobile-sink Clustering Algorithm (EMCA) have been simulated in the NS-2.32 surroundings. © 2005 - 2014 JATIT & LLS. All rights reserved.

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