| Abstract: | Data caching is an important technique in mobile computing environments for improving data availability and access latencies particularly because these computing environments are characterized by narrow bandwidth wireless links and frequent disconnections. Cache replacement policy plays a vital role to improve the performance in a cached mobile environment, since the amount of data stored in a client cache is small. In this paper we reviewed some of the well known cache replacement policies proposed for mobile data caches. We made a comparison between these policies after classifying them based on the criteria used for evicting documents. In addition, this paper suggests some alternative techniques for cache replacement |
| Description: | International Journal of Ad hoc, Sensor & Ubiquitous Computing (IJASUC) Vol.3, No.4, August 2012 |
| URI: | http://dyuthi.cusat.ac.in/purl/3870 |
| Files | Size |
|---|---|
| CACHE REPLACEMENT STRATEGIES FOR MOBILE.pdf | (112.5Kb) |
| Abstract: | This paper proposes a content based image retrieval (CBIR) system using the local colour and texture features of selected image sub-blocks and global colour and shape features of the image. The image sub-blocks are roughly identified by segmenting the image into partitions of different configuration, finding the edge density in each partition using edge thresholding, morphological dilation and finding the corner density in each partition. The colour and texture features of the identified regions are computed from the histograms of the quantized HSV colour space and Gray Level Co- occurrence Matrix (GLCM) respectively. A combined colour and texture feature vector is computed for each region. The shape features are computed from the Edge Histogram Descriptor (EHD). Euclidean distance measure is used for computing the distance between the features of the query and target image. Experimental results show that the proposed method provides better retrieving result than retrieval using some of the existing methods |
| Description: | International Journal of Advanced Science and Technology Vol. 48, November, 2012 |
| URI: | http://dyuthi.cusat.ac.in/purl/3877 |
| Files | Size |
|---|---|
| CBIR Using Loca ... es of Image Sub-blocks.pdf | (786.3Kb) |
| Abstract: | In Wireless Sensor Networks (WSN), neglecting the effects of varying channel quality can lead to an unnecessary wastage of precious battery resources and in turn can result in the rapid depletion of sensor energy and the partitioning of the network. Fairness is a critical issue when accessing a shared wireless channel and fair scheduling must be employed to provide the proper flow of information in a WSN. In this paper, we develop a channel adaptive MAC protocol with a traffic-aware dynamic power management algorithm for efficient packet scheduling and queuing in a sensor network, with time varying characteristics of the wireless channel also taken into consideration. The proposed protocol calculates a combined weight value based on the channel state and link quality. Then transmission is allowed only for those nodes with weights greater than a minimum quality threshold and nodes attempting to access the wireless medium with a low weight will be allowed to transmit only when their weight becomes high. This results in many poor quality nodes being deprived of transmission for a considerable amount of time. To avoid the buffer overflow and to achieve fairness for the poor quality nodes, we design a Load prediction algorithm. We also design a traffic aware dynamic power management scheme to minimize the energy consumption by continuously turning off the radio interface of all the unnecessary nodes that are not included in the routing path. By Simulation results, we show that our proposed protocol achieves a higher throughput and fairness besides reducing the delay |
| Description: | IJCSNS International Journal of Computer Science and Network Security, VOL.10 No.7, July 2010 |
| URI: | http://dyuthi.cusat.ac.in/purl/3907 |
| Files | Size |
|---|---|
| Channel Adaptiv ... ome Performance Issues.pdf | (281.1Kb) |
| Abstract: | Code clones are portions of source code which are similar to the original program code. The presence of code clones is considered as a bad feature of software as the maintenance of software becomes difficult due to the presence of code clones. Methods for code clone detection have gained immense significance in the last few years as they play a significant role in engineering applications such as analysis of program code, program understanding, plagiarism detection, error detection, code compaction and many more similar tasks. Despite of all these facts, several features of code clones if properly utilized can make software development process easier. In this work, we have pointed out such a feature of code clones which highlight the relevance of code clones in test sequence identification. Here program slicing is used in code clone detection. In addition, a classification of code clones is presented and the benefit of using program slicing in code clone detection is also mentioned in this work. |
| Description: | Information and Communication Technologies (WICT), 2011 World Congress on |
| URI: | http://dyuthi.cusat.ac.in/purl/3889 |
| Files | Size |
|---|---|
| Code clones in ... equence identification.pdf | (346.2Kb) |
| Abstract: | Speech processing and consequent recognition are important areas of Digital Signal Processing since speech allows people to communicate more natu-rally and efficiently. In this work, a speech recognition system is developed for re-cognizing digits in Malayalam. For recognizing speech, features are to be ex-tracted from speech and hence feature extraction method plays an important role in speech recognition. Here, front end processing for extracting the features is per-formed using two wavelet based methods namely Discrete Wavelet Transforms (DWT) and Wavelet Packet Decomposition (WPD). Naive Bayes classifier is used for classification purpose. After classification using Naive Bayes classifier, DWT produced a recognition accuracy of 83.5% and WPD produced an accuracy of 80.7%. This paper is intended to devise a new feature extraction method which produces improvements in the recognition accuracy. So, a new method called Dis-crete Wavelet Packet Decomposition (DWPD) is introduced which utilizes the hy-brid features of both DWT and WPD. The performance of this new approach is evaluated and it produced an improved recognition accuracy of 86.2% along with Naive Bayes classifier. |
| Description: | Computer Science & Information Technology (CS & IT) |
| URI: | http://dyuthi.cusat.ac.in/purl/3905 |
| Files | Size |
|---|---|
| COMBINED FEATUR ... FOR SPEECH RECOGNITION.pdf | (190.6Kb) |
| Abstract: | Speech is a natural mode of communication for people and speech recognition is an intensive area of research due to its versatile applications. This paper presents a comparative study of various feature extraction methods based on wavelets for recognizing isolated spoken words. Isolated words from Malayalam, one of the four major Dravidian languages of southern India are chosen for recognition. This work includes two speech recognition methods. First one is a hybrid approach with Discrete Wavelet Transforms and Artificial Neural Networks and the second method uses a combination of Wavelet Packet Decomposition and Artificial Neural Networks. Features are extracted by using Discrete Wavelet Transforms (DWT) and Wavelet Packet Decomposition (WPD). Training, testing and pattern recognition are performed using Artificial Neural Networks (ANN). The proposed method is implemented for 50 speakers uttering 20 isolated words each. The experimental results obtained show the efficiency of these techniques in recognizing speech |
| URI: | http://dyuthi.cusat.ac.in/purl/3912 |
| Files | Size |
|---|---|
| A Comparative S ... Isolated Spoken Words.pdf | (342.6Kb) |
| Abstract: | This paper proposes a region based image retrieval system using the local colour and texture features of image sub regions. The regions of interest (ROI) are roughly identified by segmenting the image into fixed partitions, finding the edge map and applying morphological dilation. The colour and texture features of the ROIs are computed from the histograms of the quantized HSV colour space and Gray Level co- occurrence matrix (GLCM) respectively. Each ROI of the query image is compared with same number of ROIs of the target image that are arranged in the descending order of white pixel density in the regions, using Euclidean distance measure for similarity computation. Preliminary experimental results show that the proposed method provides better retrieving result than retrieval using some of the existing methods. |
| Description: | Journal of Image and Graphics, Volume 1, No.1, March, 2013 |
| URI: | http://dyuthi.cusat.ac.in/purl/3884 |
| Files | Size |
|---|---|
| Content Based I ... ed Regions of Interest.pdf | (1.651Mb) |
| Abstract: | Due to the advancement in mobile devices and wireless networks mobile cloud computing, which combines mobile computing and cloud computing has gained momentum since 2009. The characteristics of mobile devices and wireless network makes the implementation of mobile cloud computing more complicated than for fixed clouds. This section lists some of the major issues in Mobile Cloud Computing. One of the key issues in mobile cloud computing is the end to end delay in servicing a request. Data caching is one of the techniques widely used in wired and wireless networks to improve data access efficiency. In this paper we explore the possibility of a cooperative caching approach to enhance data access efficiency in mobile cloud computing. The proposed approach is based on cloudlets, one of the architecture designed for mobile cloud computing. |
| Description: | Global Journal of Computer Science and Technology Network, Web & Security Volume 13 Issue 8 Version 1.0 Year 2013 |
| URI: | http://dyuthi.cusat.ac.in/purl/3899 |
| Files | Size |
|---|---|
| Cooperative Cac ... Mobile Cloud Computing.pdf | (650.6Kb) |
| Abstract: | Data caching can remarkably improve the efficiency of information access in a wireless ad hoc network by reducing the access latency and bandwidth usage. The cache placement problem minimizes total data access cost in ad hoc networks with multiple data items. The ad hoc networks are multi hop networks without a central base station and are resource constrained in terms of channel bandwidth and battery power. By data caching the communication cost can be reduced in terms of bandwidth as well as battery energy. As the network node has limited memory the problem of cache placement is a vital issue. This paper attempts to study the existing cooperative caching techniques and their suitability in mobile ad hoc networks. |
| Description: | Data Science & Engineering (ICDSE), 2012 International Conference on |
| URI: | http://dyuthi.cusat.ac.in/purl/3871 |
| Files | Size |
|---|---|
| Cooperative Caching Techniques for Mobile.pdf | (146.8Kb) |
| Abstract: | Decimal multiplication is an integral part offinancial, commercial, and internet-based computations. The basic building block of a decimal multiplier is a single digit multiplier. It accepts two Binary Coded Decimal (BCD) inputs and gives a product in the range [0, 81] represented by two BCD digits. A novel design for single digit decimal multiplication that reduces the critical path delay and area is proposed in this research. Out of the possible 256 combinations for the 8-bit input, only hundred combinations are valid BCD inputs. In the hundred valid combinations only four combinations require 4 x 4 multiplication, combinations need x multiplication, and the remaining combinations use either x or x 3 multiplication. The proposed design makes use of this property. This design leads to more regular VLSI implementation, and does not require special registers for storing easy multiples. This is a fully parallel multiplier utilizing only combinational logic, and is extended to a Hex/Decimal multiplier that gives either a decimal output or a binary output. The accumulation ofpartial products generated using single digit multipliers is done by an array of multi-operand BCD adders for an (n-digit x n-digit) multiplication. |
| Description: | Electronic Design, 2008. ICED 2008. International Conference on |
| URI: | http://dyuthi.cusat.ac.in/purl/3860 |
| Files | Size |
|---|---|
| Decimal Multipl ... compact BCD Multiplier.pdf | (1.493Mb) |
| Abstract: | The demand for new telecommunication services requiring higher capacities, data rates and different operating modes have motivated the development of new generation multi-standard wireless transceivers. A multi-standard design often involves extensive system level analysis and architectural partitioning, typically requiring extensive calculations. In this research, a decimation filter design tool for wireless communication standards consisting of GSM, WCDMA, WLANa, WLANb, WLANg and WiMAX is developed in MATLAB® using GUIDE environment for visual analysis. The user can select a required wireless communication standard, and obtain the corresponding multistage decimation filter implementation using this toolbox. The toolbox helps the user or design engineer to perform a quick design and analysis of decimation filter for multiple standards without doing extensive calculation of the underlying methods. |
| Description: | World Academy of Science, Engineering and Technology Vol:3 2009-11-22 |
| URI: | http://dyuthi.cusat.ac.in/purl/3890 |
| Files | Size |
|---|---|
| Decimation Filt ... nsceivers using MATLAB.pdf | (488.1Kb) |
| Abstract: | The evolution of wireless sensor network technology has enabled us to develop advanced systems for real time monitoring. In the present scenario wireless sensor networks are increasingly being used for precision agriculture. The advantages of using wireless sensor networks in agriculture are distributed data collection and monitoring, monitor and control of climate, irrigation and nutrient supply. Hence decreasing the cost of production and increasing the efficiency of production. This paper describes the development and deployment of wireless sensor network for crop monitoring in the paddy fields of Kuttanad, a region of Kerala, the southern state of India. |
| Description: | International Journal of Engineering and Innovative Technology (IJEIT) Volume 2, Issue 1, July 2012 |
| URI: | http://dyuthi.cusat.ac.in/purl/3908 |
| Files | Size |
|---|---|
| Development and ... ddy Fields of Kuttanad.pdf | (428.7Kb) |
| Abstract: | The recent trends envisage multi-standard architectures as a promising solution for the future wireless transceivers. The computationally intensive decimation filter plays an important role in channel selection for multi-mode systems. An efficient reconfigurable implementation is a key to achieve low power consumption. To this end, this paper presents a dual-mode Residue Number System (RNS) based decimation filter which can be programmed for WCDMA and 802.11a standards. Decimation is done using multistage, multirate finite impulse response (FIR) filters. These FIR filters implemented in RNS domain offers high speed because of its carry free operation on smaller residues in parallel channels. Also, the FIR filters exhibit programmability to a selected standard by reconfiguring the hardware architecture. The total area is increased only by 33% to include WLANa compared to a single mode WCDMA transceiver. In each mode, the unused parts of the overall architecture is powered down and bypassed to attain power saving. The performance of the proposed decimation filter in terms of critical path delay and area are tabulated |
| Description: | Circuits and Systems, 2008. ISCAS 2008. IEEE International Symposium on Pages 952-955 |
| URI: | http://dyuthi.cusat.ac.in/purl/3875 |
| Files | Size |
|---|---|
| Dual-Mode RNS based Programmable Decimation.pdf | (177.9Kb) |
| Abstract: | Iris Recognition is a highly efficient biometric identification system with great possibilities for future in the security systems area.Its robustness and unobtrusiveness, as opposed tomost of the currently deployed systems, make it a good candidate to replace most of thesecurity systems around. By making use of the distinctiveness of iris patterns, iris recognition systems obtain a unique mapping for each person. Identification of this person is possible by applying appropriate matching algorithm.In this paper, Daugman’s Rubber Sheet model is employed for irisnormalization and unwrapping, descriptive statistical analysis of different feature detection operators is performed, features extracted is encoded using Haar wavelets and for classification hammingdistance as a matching algorithm is used. The system was tested on the UBIRIS database. The edge detection algorithm, Canny, is found to be the best one to extract most of the iris texture. The success rate of feature detection using canny is 81%, False Accept Rate is 9% and False Reject Rate is 10%. |
| Description: | International Journal of Network Security & Its Applications (IJNSA), Vol.5, No.5, September 2013 |
| URI: | http://dyuthi.cusat.ac.in/purl/3904 |
| Files | Size |
|---|---|
| EFFECTIVENESS O ... RIC RECOGNITION SYSTEM.pdf | (672.7Kb) |
| Abstract: | With the increasing popularity of wireless network and its application, mobile ad-hoc networks (MANETS) emerged recently. MANET topology is highly dynamic in nature and nodes are highly mobile so that the rate of link failure is more in MANET. There is no central control over the nodes and the control is distributed among nodes and they can act as either router or source. MANTEs have been considered as isolated stand-alone network. Node can add or remove at any time and it is not infrastructure dependent. So at any time at any where the network can setup and a trouble free communication is possible. Due to more chances of link failures, collisions and transmission errors in MANET, the maintenance of network became costly. As per the study more frequent link failures became an important aspect of diminishing the performance of the network and also it is not predictable. The main objective of this paper is to study the route instability in AODV protocol and suggest a solution for improvement. This paper proposes a new approach to reduce the route failure by storing the alternate route in the intermediate nodes. In this algorithm intermediate nodes are also involved in the route discovery process. This reduces the route establishment overhead as well as the time to find the reroute when a link failure occurs. |
| Description: | International Journal of Advanced Research in Computer and Communication Engineering Vol. 2, Issue 6, June 2013 |
| URI: | http://dyuthi.cusat.ac.in/purl/3913 |
| Files | Size |
|---|---|
| An Effective Pa ... ute Stability in MANET.pdf | (513.4Kb) |
| Abstract: | Data caching is an attractive solution for reducing bandwidth demands and network latency in mobile ad hoc networks. Deploying caches in mobile nodes can reduce the overall traf c considerably. Cache hits eliminate the need to contact the data source frequently, which avoids additional network overhead. In this paper we propose a data discovery and cache management policy for cooperative caching, which reduces the power usage, caching overhead and delay by reducing the number of control messages flooded into the network .A cache discovery process based on position cordinates of neighboring nodes is developed for this .The stimulstion results gives a promising result based on the metrics of the studies. |
| Description: | Elsevier publications 2013 |
| URI: | http://dyuthi.cusat.ac.in/purl/3910 |
| Files | Size |
|---|---|
| Energy Efficien ... Mobile Ad oc Networks.pdf | (267.4Kb) |
| Abstract: | The evolution of wireless sensor network technology has enabled us to develop advanced systems for real time monitoring. In the present scenario wireless sensor networks are increasingly being used for precision agriculture. The advantages of using wireless sensor networks in agriculture are distributed data collection and monitoring, monitor and control of climate, irrigation and nutrient supply. Hence decreasing the cost of production and increasing the efficiency of production. This paper describes the security issues related to wireless sensor networks and suggests some techniques for achieving system security. This paper also discusses a protocol that can be adopted for increasing the security of the transmitted data |
| Description: | International Journal of Engineering and Innovative Technology (IJEIT) Volume 3, Issue 4, October 2013 |
| URI: | http://dyuthi.cusat.ac.in/purl/3911 |
| Files | Size |
|---|---|
| Energy Optimize ... reless Sensor Networks.pdf | (384.0Kb) |
| Abstract: | Sensor networks are one of the fastest growing areas in broad of a packet is in transit at any one time. In GBR, each node in the network can look at itsneighbors wireless ad hoc networking (? Eld. A sensor node, typically'hop count (depth) and use this to decide which node to forward contains signal-processing circuits, micro-controllers and a the packet on to. If the nodes' power level drops below a wireless transmitter/receiver antenna. Energy saving is one certain level it will increase the depth to discourage trafiE of the critical issue for sensor networks since most sensors are equipped with non-rechargeable batteries that have limitedlifetime. Routing schemes are used to transfer data collectedby sensor nodes to base stations. In the literature many routing protocols for wireless sensor networks are suggested. In this work, four routing protocols for wireless sensor networks viz Flooding, Gossiping, GBR and LEACH have been simulated using TinyOS and their power consumption is studied using PowerTOSSIM. A realization of these protocols has beencarried out using Mica2 Motes. |
| Description: | Ad Hoc and Ubiquitous Computing, 2006. ISAUHC'06. International Symposium on |
| URI: | http://dyuthi.cusat.ac.in/purl/3882 |
| Files | Size |
|---|---|
| Evaluation of t ... reless Sensor Networks.pdf | (906.1Kb) |
| Abstract: | In recent years, reversible logic has emerged as one of the most important approaches for power optimization with its application in low power CMOS, quantum computing and nanotechnology. Low power circuits implemented using reversible logic that provides single error correction – double error detection (SEC-DED) is proposed in this paper. The design is done using a new 4 x 4 reversible gate called ‘HCG’ for implementing hamming error coding and detection circuits. A parity preserving HCG (PPHCG) that preserves the input parity at the output bits is used for achieving fault tolerance for the hamming error coding and detection circuits. |
| Description: | TENCON 2007-2007 IEEE Region 10 Conference |
| URI: | http://dyuthi.cusat.ac.in/purl/3859 |
| Files | Size |
|---|---|
| Fault Tolerant ... ng and Detection using.pdf | (168.5Kb) |
| Abstract: | Speech signals are one of the most important means of communication among the human beings. In this paper, a comparative study of two feature extraction techniques are carried out for recognizing speaker independent spoken isolated words. First one is a hybrid approach with Linear Predictive Coding (LPC) and Artificial Neural Networks (ANN) and the second method uses a combination of Wavelet Packet Decomposition (WPD) and Artificial Neural Networks. Voice signals are sampled directly from the microphone and then they are processed using these two techniques for extracting the features. Words from Malayalam, one of the four major Dravidian languages of southern India are chosen for recognition. Training, testing and pattern recognition are performed using Artificial Neural Networks. Back propagation method is used to train the ANN. The proposed method is implemented for 50 speakers uttering 20 isolated words each. Both the methods produce good recognition accuracy. But Wavelet Packet Decomposition is found to be more suitable for recognizing speech because of its multi-resolution characteristics and efficient time frequency localizations |
| Description: | Advances in Computing and Communications (ICACC), 2012 International Conference on |
| URI: | http://dyuthi.cusat.ac.in/purl/3888 |
| Files | Size |
|---|---|
| Feature Extract ... ken Words in Malayalam.pdf | (261.9Kb) |
Dyuthi Digital Repository Copyright © 2007-2011 Cochin University of Science and Technology. Items in Dyuthi are protected by copyright, with all rights reserved, unless otherwise indicated.