Now showing items 1-20 of 51
Next Page| Abstract: | The present work is an attempt to explain particle production in the early univese. We argue that nonzero values of the stress-energy tensor evaluated in squeezed vacuum state can be due to particle production and this supports the concept of particle production from zero-point quantum fluctuations. In the present calculation we use the squeezed coherent state introduced by Fan and Xiao [7]. The vacuum expectation values of stressenergy tensor defined prior to any dynamics in the background gravitational field give all information about particle production. Squeezing of the vacuum is achieved by means of the background gravitational field, which plays the role of a parametric amplifier [8]. The present calculation shows that the vacuum expectation value of the energy density and pressure contain terms in addition to the classical zero-point energy terms. The calculation of the particle production probability shows that the probability increases as the squeezing parameter increases, reaches a maximum value, and then decreases. |
| Description: | International Journal of Theoretical Physics, Vol. 39, No. 2, 2000 |
| URI: | http://dyuthi.cusat.ac.in/purl/4173 |
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| Squeezed Cohere ... n in the EarlyUniverse.pdf | (75.28Kb) |
| Abstract: | The present work is an attempt to explain particle production in the early univese. We argue that nonzero values of the stress-energy tensor evaluated in squeezed vacuum state can be due to particle production and this supports the concept of particle production from zero-point quantum fluctuations. In the present calculation we use the squeezed coherent state introduced by Fan and Xiao [7]. The vacuum expectation values of stressenergy tensor defined prior to any dynamics in the background gravitational field give all information about particle production. Squeezing of the vacuum is achieved by means of the background gravitational field, which plays the role of a parametric amplifier [8]. The present calculation shows that the vacuum expectation value of the energy density and pressure contain terms in addition to the classical zero-point energy terms. The calculation of the particle production probability shows that the probability increases as the squeezing parameter increases, reaches a maximum value, and then decreases. |
| Description: | International Journal of Theoretical Physics, Vol. 39, No. 2, 2000 |
| URI: | http://dyuthi.cusat.ac.in/purl/4148 |
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| Squeezed Cohere ... in the Early Universe.pdf | (75.28Kb) |
| 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 forfor sensor networks since most sensors are equipped with non-rechargeable batteries that have limited lifetime. |
| Description: | Ad Hoc and Ubiquitous Computing, 2006. ISAUHC'06. International Symposium on |
| URI: | http://dyuthi.cusat.ac.in/purl/4145 |
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| Evaluation of the Power Consumption of.pdf | (906.1Kb) |
| Abstract: | Wireless sensor networks monitor their surrounding environment for the occurrence of some anticipated phenomenon. Most of the research related to sensor networks considers the static deployment of sensor nodes. Mobility of sensor node can be considered as an extra dimension of complexity, which poses interesting and challenging problems. Node mobility is a very important aspect in the design of effective routing algorithm for mobile wireless networks. In this work we intent to present the impact of different mobility models on the performance of the wireless sensor networks. Routing characteristics of various routing protocols for ad-hoc network were studied considering different mobility models. Performance metrics such as end-to-end delay, throughput and routing load were considered and their variations in the case of mobility models like Freeway, RPGM were studied. This work will be useful to figure out the characteristics of routing protocols depending on the mobility patterns of sensors |
| Description: | International Conference on Sensors and Related Networks (SENNET’07), VIT University, Vellore, India. Dec. 12-14, 2007. pp.480-485. |
| URI: | http://dyuthi.cusat.ac.in/purl/4176 |
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| Impact of Node ... reless Sensor Networks.pdf | (147.2Kb) |
| Abstract: | In this paper, we have evolved a generic software architecture for a domain specific distributed embedded system. The system under consideration belongs to the Command, Control and Communication systems domain. The systems in such domain have very long operational lifetime. The quality attributes of these systems are equally important as the functional requirements. The main guiding principle followed in this paper for evolving the software architecture has been functional independence of the modules. The quality attributes considered most important for the system are maintainability and modifiability. Architectural styles best suited for the functionally independent modules are proposed with focus on these quality attributes. The software architecture for the system is envisioned as a collection of architecture styles of the functionally independent modules identified |
| Description: | 2007 international conference on software emgineering theory and practice(SETP-07) |
| URI: | http://dyuthi.cusat.ac.in/purl/4177 |
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| A Generic Softw ... ibuted Embedded System.pdf | (473.8Kb) |
| Abstract: | This paper presents methods for moving object detection in airborne video surveillance. The motion segmentation in the above scenario is usually difficult because of small size of the object, motion of camera, and inconsistency in detected object shape etc. Here we present a motion segmentation system for moving camera video, based on background subtraction. An adaptive background building is used to take advantage of creation of background based on most recent frame. Our proposed system suggests CPU efficient alternative for conventional batch processing based background subtraction systems. We further refine the segmented motion by meanshift based mode association. |
| Description: | IADIS International Conference Computer Graphics and Visualization 2008 |
| URI: | http://dyuthi.cusat.ac.in/purl/4174 |
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| Motion Segmenta ... ent For Airborne Video.pdf | (234.0Kb) |
| Abstract: | Cluster based protocols like LEACH were found best suited for routing in wireless sensor networks. In mobility centric environments some improvements were suggested in the basic scheme. LEACH-Mobile is one such protocol. The basic LEACH protocol is improved in the mobile scenario by ensuring whether a sensor node is able to communicate with its cluster head. Since all the nodes, including cluster head is moving it will be better to elect a node as cluster head which is having less mobility related to its neighbours. In this paper, LEACH-Mobile protocol has been enhanced based on a mobility metric “remoteness” for cluster head election. This ensures high success rate in data transfer between the cluster head and the collector nodes even though nodes are moving. We have simulated and compared our LEACH-Mobile-Enhanced protocol with LEACHMobile. Results show that inclusion of neighbouring node information improves the routing protocol. |
| Description: | Advanced Computing and Communications, 2008. ADCOM 2008. 16th International Conference on |
| URI: | http://dyuthi.cusat.ac.in/purl/4135 |
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| Mobility Metric based LEACH-Mobile Protocol.pdf | (272.3Kb) |
| Abstract: | In wireless sensor networks, the routing algorithms currently available assume that the sensor nodes are stationary. Therefore when mobility modulation is applied to the wireless sensor networks, most of the current routing algorithms suffer from performance degradation. The path breaks in mobile wireless networks are due to the movement of mobile nodes, node failure, channel fading and shadowing. It is desirable to deal with dynamic topology changes with optimal effort in terms of resource and channel utilization. As the nodes in wireless sensor medium make use of wireless broadcast to communicate, it is possible to make use of neighboring node information to recover from path failure. Cooperation among the neighboring nodes plays an important role in the context of routing among the mobile nodes. This paper proposes an enhancement to an existing protocol for accommodating node mobility through neighboring node information while keeping the utilization of resources to a minimum. |
| Description: | TENCON 2008-2008 IEEE Region 10 Conference |
| URI: | http://dyuthi.cusat.ac.in/purl/4136 |
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| Routing Protoco ... reless Sensor Networks.pdf | (245.2Kb) |
| Abstract: | In Safety critical software failure can have a high price. Such software should be free of errors before it is put into operation. Application of formal methods in the Software Development Life Cycle helps to ensure that the software for safety critical missions are ultra reliable. PVS theorem prover, a formal method tool, can be used for the formal verification of software in ADA Language for Flight Software Application (ALFA.). This paper describes the modeling of ALFA programs for PVS theorem prover. An ALFA2PVS translator is developed which automatically converts the software in ALFA to PVS specification. By this approach the software can be verified formally with respect to underflow/overflow errors and divide by zero conditions without the actual execution of the code |
| Description: | 2009 International Conference on Advances in Recent Technologies in Communication and Computing |
| URI: | http://dyuthi.cusat.ac.in/purl/4179 |
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| Modeling of ALF ... ing PVS Theorem Prover.pdf | (395.1Kb) |
| Abstract: | Suffix separation plays a vital role in improving the quality of training in the Statistical Machine Translation from English into Malayalam. The morphological richness and the agglutinative nature of Malayalam make it necessary to retrieve the root word from its inflected form in the training process. The suffix separation process accomplishes this task by scrutinizing the Malayalam words and by applying sandhi rules. In this paper, various handcrafted rules designed for the suffix separation process in the English Malayalam SMT are presented. A classification of these rules is done based on the Malayalam syllable preceding the suffix in the inflected form of the word (check_letter). The suffixes beginning with the vowel sounds like ആല, ഉെെ, ഇല etc are mainly considered in this process. By examining the check_letter in a word, the suffix separation rules can be directly applied to extract the root words. The quick look up table provided in this paper can be used as a guideline in implementing suffix separation in Malayalam language |
| URI: | http://dyuthi.cusat.ac.in/purl/4185 |
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| A Classificatio ... eparation in Malayalam.pdf | (420.0Kb) |
| Abstract: | In Safety critical software failure can have a high price. Such software should be free of errors before it is put into operation. Application of formal methods in the Software Development Life Cycle helps to ensure that the software for safety critical missions are ultra reliable. PVS theorem prover, a formal method tool, can be used for the formal verification of software in ADA Language for Flight Software Application (ALFA.). This paper describes the modeling of ALFA programs for PVS theorem prover. An ALFA2PVS translator is developed which automatically converts the software in ALFA to PVS specification. By this approach the software can be verified formally with respect to underflow/overflow errors and divide by zero conditions without the actual execution of the code. |
| Description: | 2009 International Conference on Advances in Recent Technologies in Communication and Computing |
| URI: | http://dyuthi.cusat.ac.in/purl/4147 |
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| Modeling of ALF ... ing PVS Theorem Prover.pdf | (395.4Kb) |
| Abstract: | In this paper we address the problem of face detection and recognition of grey scale frontal view images. We propose a face recognition system based on probabilistic neural networks (PNN) architecture. The system is implemented using voronoi/ delaunay tessellations and template matching. Images are segmented successfully into homogeneous regions by virtue of voronoi diagram properties. Face verification is achieved using matching scores computed by correlating edge gradients of reference images. The advantage of classification using PNN models is its short training time. The correlation based template matching guarantees good classification results |
| Description: | Nature & Biologically Inspired Computing, 2009. NaBIC 2009. World Congress on |
| URI: | http://dyuthi.cusat.ac.in/purl/4142 |
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| Face Recognitio ... listic Neural Networks.pdf | (216.3Kb) |
| Abstract: | Embedded systems, especially Wireless Sensor Nodes are highly prone to Type Safety and Memory Safety issues. Contiki, a prominent Operating System in the domain is even more affected by the problem since it makes extensive use of Type casts and Pointers. The work is an attempt to nullify the possibility of Safety violations in Contiki. We use a powerful, still efficient tool called Deputy to achieve this. We also try to automate the process |
| Description: | 2009 International Conference on Advances in Recent Technologies in Communication and Computing |
| URI: | http://dyuthi.cusat.ac.in/purl/4144 |
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| Safe Contiki OS ... Safety for Contiki OS.pdf | (360.9Kb) |
| Abstract: | n this paper we address the problem of face detection and recognition of grey scale frontal view images. We propose a face recognition system based on probabilistic neural networks (PNN) architecture. The system is implemented using voronoi/ delaunay tessellations and template matching. Images are segmented successfully into homogeneous regions by virtue of voronoi diagram properties. Face verification is achieved using matching scores computed by correlating edge gradients of reference images. The advantage of classification using PNN models is its short training time. The correlation based template matching guarantees good classification results. |
| URI: | http://dyuthi.cusat.ac.in/purl/4183 |
| Files | Size |
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| Face Recognitio ... listic Neural Networks.pdf | (218.8Kb) |
| Abstract: | Embedded systems, especially Wireless Sensor Nodes are highly prone to Type Safety and Memory Safety issues. Contiki, a prominent Operating System in the domain is even more affected by the problem since it makes extensive use of Type casts and Pointers. The work is an attempt to nullify the possibility of Safety violations in Contiki. We use a powerful, still efficient tool called Deputy to achieve this. We also try to automate the process |
| Description: | 2009 International Conference on Advances in Recent Technologies in Communication and Computing |
| URI: | http://dyuthi.cusat.ac.in/purl/4180 |
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| Safe Contiki OS ... Safety for Contiki OS.pdf | (361.1Kb) |
| Abstract: | In this paper we describe the methodology and the structural design of a system that translates English into Malayalam using statistical models. A monolingual Malayalam corpus and a bilingual English/Malayalam corpus are the main resource in building this Statistical Machine Translator. Training strategy adopted has been enhanced by PoS tagging which helps to get rid of the insignificant alignments. Moreover, incorporating units like suffix separator and the stop word eliminator has proven to be effective in bringing about better training results. In the decoder, order conversion rules are applied to reduce the structural difference between the language pair. The quality of statistical outcome of the decoder is further improved by applying mending rules. Experiments conducted on a sample corpus have generated reasonably good Malayalam translations and the results are verified with F measure, BLEU and WER evaluation metrics |
| Description: | Proceedings of Fourth International Conference on Information Processing, Bangalore, India |
| URI: | http://dyuthi.cusat.ac.in/purl/4138 |
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| A Framework of ... m English to Malayalam.pdf | (363.2Kb) |
| Abstract: | In Statistical Machine Translation from English to Malayalam, an unseen English sentence is translated into its equivalent Malayalam translation using statistical models like translation model, language model and a decoder. A parallel corpus of English-Malayalam is used in the training phase. Word to word alignments has to be set up among the sentence pairs of the source and target language before subjecting them for training. This paper is deals with the techniques which can be adopted for improving the alignment model of SMT. Incorporating the parts of speech information into the bilingual corpus has eliminated many of the insignificant alignments. Also identifying the name entities and cognates present in the sentence pairs has proved to be advantageous while setting up the alignments. Moreover, reduction of the unwanted alignments has brought in better training results. Experiments conducted on a sample corpus have generated reasonably good Malayalam translations and the results are verified with F measure, BLEU and WER evaluation metrics |
| URI: | http://dyuthi.cusat.ac.in/purl/4187 |
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| Techniques to I ... m English to Malayalam.pdf | (368.5Kb) |
| Abstract: | DNA sequence representation methods are used to denote a gene structure effectively and help in similarities/dissimilarities analysis of coding sequences. Many different kinds of representations have been proposed in the literature. They can be broadly classified into Numerical, Graphical, Geometrical and Hybrid representation methods. DNA structure and function analysis are made easy with graphical and geometrical representation methods since it gives visual representation of a DNA structure. In numerical method, numerical values are assigned to a sequence and digital signal processing methods are used to analyze the sequence. Hybrid approaches are also reported in the literature to analyze DNA sequences. This paper reviews the latest developments in DNA Sequence representation methods. We also present a taxonomy of various methods. A comparison of these methods where ever possible is also done |
| Description: | Proceedings of the International Symposium on Biocomputing |
| URI: | http://dyuthi.cusat.ac.in/purl/4182 |
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| DNA Sequence Representation methods.pdf | (223.4Kb) |
| Description: | Current Trends in Wireless Networking. DigitalLibrary@CUSAT. ... |
| URI: | http://dyuthi.cusat.ac.in/purl/4181 |
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| Current Trends in WirelessNetworking.pdf | (7.463Mb) |
| Abstract: | In wireless sensor networks, the routing algorithms currently available assume that the sensor nodes are stationary. Therefore when mobility modulation is applied to the wireless sensor networks, most of the current routing algorithms suffer from performance degradation. The path breaks in mobile wireless networks are due to the movement of mobile nodes, node failure, channel fading and shadowing. It is desirable to deal with dynamic topology changes with optimal effort in terms of resource and channel utilization. As the nodes in wireless sensor medium make use of wireless broadcast to communicate, it is possible to make use of neighboring node information to recover from path failure. Cooperation among the neighboring nodes plays an important role in the context of routing among the mobile nodes. This paper proposes an enhancement to an existing protocol for accommodating node mobility through neighboring node information while keeping the utilization of resources to a minimum. |
| URI: | http://dyuthi.cusat.ac.in/purl/4175 |
| Files | Size |
|---|---|
| Routing Protoco ... reless Sensor Networks.pdf | (246.2Kb) |
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