Cmr Institute Of Technology

Bangalore, India

Cmr Institute Of Technology

Bangalore, India
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Reddy J.,Rashtreeya Vidyalaya College of Engineering | Kishore M.J.,CMR Institute of Technology
International Journal of Electrical Power and Energy Systems | Year: 2011

This paper presents the simulation and the experimental validation of the designed robust power system stabilizer (RPSS) to stabilize a linearized uncertain power system using Glover-McFarlane's H∞ loop shaping design procedure. Guidance for setting the feedback configuration for loop shaping, weighing functions selection and synthesis are also presented. The efficiency of the designed controller is simulated using Matlab/Simulink and tested by implementing on real time environment using dSPACE work stations DS1005 and DS1104. The real time experimental results of RPSS are compared with that of the conventional power system stabilizer (CPSS) for a three phase fault. Also, the real time simulation results of RPSS are compared with the off-line simulation results of RPSS, thus validating the simulation results with the experimental results. Justification of robustness is also presented by considering three different operating points. The proposed method presented in this paper shows the effectiveness of the RPSS in damping the power system oscillations. © 2011 Elsevier Ltd. All rights reserved.


Sreekanth V.,CMR Institute of Technology
Science of the Total Environment | Year: 2013

Long-term (8. years), simultaneous data on aerosol optical properties from MODIS and OMI satellite sensors are analyzed to study their temporal characteristics and to infer on the major aerosol types present over the study location, Bangalore situated in south central peninsular India. Investigations are carried out on Aerosol Optical Depths (AODs), Angstrom exponent (α) and Aerosol Index (AI) for the purpose. Aerosol parameters exhibited significant seasonal variations: AODs peaking during monsoon, α during post-monsoon and AI during summer. Seasonal air mass back trajectories are computed to infer on the transport component over the study region. By assigning proper thresholds (depending on the nature of the location and transport pathways) on AOD and α values, aerosols are discriminated into their major types viz., marine influenced, desert dust, urban/industrialized and mixed types. Further sub-categorization of the aerosols has been done on an annual scale taking into account of their absorptance information in terms of the OMI-AI values. Mixed type aerosols contributed the most during all the seasons. Next to mixed type aerosols, marine influenced aerosols dominated during winter, desert dust during monsoon and summer, urban/industrialized aerosols during post-monsoon. Considering the urban nature of the study location, urban/industrialized/carbonaceous type aerosols have been significantly underestimated in these methodologies. Finally, discussion has been made on the consistency of the results obtained from the methodologies (i) based on AODs and α; (ii) based on AODs, α and AI. © 2013 Elsevier B.V.


Sreekanth V.,CMR Institute of Technology
Atmospheric Environment | Year: 2014

In this paper, a simple methodology for deducing a proxy index inferring on the dust aerosol layer height (in the atmosphere) has been presented by exploiting the dependence of the relationship between Aerosol Index (AI) and aerosol optical thickness (AOT) on the aerosol altitude. For the purpose, OMI-AI and GOCART model simulated dust AOT values over northern Arabian Sea are used. Northern Arabian Sea has been chosen as the study grid due its frequent vulnerability to the Arabian dust storms. Temporal variations in the dust AOT and AI values over the study region are discussed. Linear regression to the scatter plots between the dust AOT and AI values revealed the qualitative information on the dust layer altitudes. Results indicated that dust aerosols over the study region attain their highest altitude during July, August months. CALIOP aerosol sub-type measurements are examined in order to support the results obtained. Expansion of the present technique on inferring the spatio-temporal variability in the aerosol altitude over dust storms prone regions can be highly advantageous in fine tuning the regional dust aerosol radiative forcing calculations. © 2014 Elsevier Ltd.


Jhansi Rani P.,CMR Institute of Technology
ACM International Conference Proceeding Series | Year: 2016

We propose pseudo random bit generator(PRBG) by con-structing an ergodic orbit of logistic map generated using in-termittent perturbation and sampling the orbit using Bernoulli shift map. The pseudo randomness of the key streams is tested with the standard NIST statistical test suite. The key streams generated by the proposed PRBG pass all the tests of the test suite. As an application of PRBG we propose chaotic stream ciphers. Goodness-of-Fit tests are conducted for these ciphers. Stream ciphers generated using PRBG are shown to generate ciphers in which the distribution of the characters show significant correlation to the uniform distribution. It is also shown that the ciphers exhibit good avalanche effect when the initial seed is varied infinitesimally and we can also clearly observe the avalanche effect at dif-ferent points within the ciphertext as the ciphertext is being generated. Also we show that the proposed PRBG is on par with conventional PRBG RC4. This indeed vindicates our hypothesis that stream of bits obtained from orbits of logis-tic map using perturbation and Bernoulli shift map exhibits randomness. © 2016 ACM.


Jhansi Rani P.,CMR Institute of Technology
ACM International Conference Proceeding Series | Year: 2016

Hashing is used as part of IPSec protocol to ensure that the data being sent has not been tampered or corrupted over the virtual private network(VPN). This can be done using SHA1 or MD5. First 96-bits of the message digest of SHA1 or MD5 are used as an authentication field. This paper shows that the Bernoulli keyed hash function can be used to authenticate the data. Longer length message digest is more resistant to collisions. Here even after truncating the 128-bits of the message digest to extract 96-bits, the Bernoulli keyed hash function is shown be resistant to collisions and possessing strong confusion and diffusion capabilities. © 2016 ACM.


Sreekanth V.,CMR Institute of Technology
Advances in Space Research | Year: 2016

Spatial and seasonal variations in the linear long-term trend estimates of aerosol and cloud properties over Indian subcontinent and the surrounding oceanic regions of Bay of Bengal (BoB) and Arabian Sea (AS) are studied and discussed utilizing 12 complete years (2003-2014) of Moderate Resolution Imaging Spectroradiometer (MODIS) derived Aerosol and cloud products. Annual Aerosol Optical Depth (AOD) trends (in terms of AOD/year) are found to be positive (upward) over most of the study region with a spatial mean (median) value of ∼0.0065 (0.0064) and exhibited significant spatial and seasonal heterogeneity. Over Indian landmass AOD trends and their statistical significance decreased towards north along the Indo-Gangetic plains (IGP), for which the probable causes are discussed. Same kind of pattern in AOD trends has been observed as we move deeper into the oceanic regions of BoB and AS, away from Indian subcontinent. Observed trend patterns are discussed in light of the possible increase in emissions (over Indian landmass) and transported aerosol component, co-variation with trends in meteorological parameters and their possible feedbacks. Trend maps in seasonal AOD are shown to understand the aerosol build up over the study region under varying meteorological conditions. Seasonal AOD trend patterns resembled the synoptic scale wind circulation over the study region revealing that the upward trend in aerosol abundance over the adjoining oceanic regions of India is a result of effective transport of increasing emissions over India on to them. No significant trends in cloud properties (over the whole study region) are depicted in concert with that of aerosols, except over few pockets. The study also highlighted the role of large scale atmospheric processes in modulating the shape of the AOD time series over the regions with significant abundance of natural aerosol component (dust). © 2016 COSPAR.


Sreekanth V.,CMR Institute of Technology
Advances in Space Research | Year: 2013

Climatological aerosol optical depths (AOD) over Bangalore, India have been examined to bring out the temporal heterogeneity in columnar aerosol characteristics. AOD values at 550 nm derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor onboard NASA's Terra and Aqua satellites, for the period of 2002-2011 have been analyzed (independently) for the purpose. Frequency distributions of the AOD values are examined to infer the monthly mean values. Monthly and seasonal variations of AOD are investigated in the light of regional synoptic meteorology. Climatological monthly and seasonal mean Terra and Aqua AOD values exhibited similar temporal variation patterns. Monthly mean AOD values increased from January, peaks during May and thereafter (except for a secondary peak during July) fall off to reach a minimum during December. Monsoon season recorded the highest climatological seasonal mean AOD, while winter season recorded the lowest. AOD values show an overall increasing trend on a yearly basis, which was found mainly due to sustained increase in the seasonal averaged AOD during summer. The results obtained in the present study are compared with that of the earlier studies over the same location and also with AOD over various other Indian locations. Finally, the radiative and climatic impacts are discussed. © 2013 COSPAR. Published by Elsevier Ltd. All rights reserved.


Sreekanth V.,CMR Institute of Technology | Kulkarni P.,CMR Institute of Technology
Atmospheric Environment | Year: 2013

Multiyear all-season characterization of the columnar optical properties of aerosols over Bay of Bengal (BoB) has been carried out using simultaneous data from MODIS and TOMS satellite sensors. Significant spatio-temporal heterogeneity has been observed in the columnar aerosol optical properties over BoB. Latitudinally, MODIS derived Aerosol optical depths (AOD), its Small mode fraction (SMF, except pre-monsoon) has shown increasing trends towards northern latitudes of BoB. A pocket of high Aerosol Index (AI) values has been observed over the north-western part of BoB during pre-monsoon. Longitudinally, the variations in the aerosol properties are subdued comparatively. SMF values tend to increase weakly towards eastern longitudes during all the seasons. Variations in the aerosol properties are parameterised using best fit analytical functions. By simultaneous examination of AI, AOD and SMF, it has been inferred that the aerosol load responsible for the higher values of AI over BoB during pre-monsoon is dominated by the transported UV-absorbing dust. © 2013 Elsevier Ltd.


Kumar N.,CMR Institute of Technology
2013 IEEE International Conference on "Smart Structures and Systems", ICSSS 2013 | Year: 2013

The activities and researches in conceptualizing smart infrastructures around us are growing. Advancement in information and communication technology (ICT) in fact enables an entity or a system smart and intelligent. This paper discusses a concept towards developing a smart city using intelligent energy efficient public illumination system which would also offer ubiquitous communication. It discusses the usage of energy efficient intelligent illumination which can automatically adjust the intensity of lights depending on surrounding environment that are continuously monitored using sensor networks. The system is based on semiconductor light emitting diodes (LEDs) which are efficiently and effectively controlled. Furthermore, its inherent characteristic of high rate switching can be used for data communication enabling simultaneous use of illumination and communication. A case scenario of road illumination is also discussed and through simulation studies, it is reported that data communication at high rate is possible using the lighting infrastructures. © 2013 IEEE.


Anand D.,CMR Institute of Technology | Mampilli B.S.,Bangalore University
Expert Systems with Applications | Year: 2014

Genre is a major factor influencing user decisions to peruse an item in domains such as movies, books etc. Recommender systems, generally have, at their disposal, information regarding genres/categories that a movie/book belongs to. However, the degree of membership of the objects in these categories is typically unavailable. Such information, if available, would provide a better description of items and consequently lead to quality recommendations. In this paper, we propose an approach to infer the degree of genre presence in a movie by examining the various tags conferred on them by various users. Tags are user-defined metadata for items and embed abundant information about various facets of user likes, their opinion on the quality and the type of object tagged. Leveraging on tags to guide the genre degree determination exploits crowd sourcing to enrich item content description. Fuzzy logic naturally models human logic allowing for the nuanced representation of features of objects and thus is utilized to derive such gradual representation as well as for modeling user profiles. To the best of our knowledge ours is one of the first approaches to utilize such folksonomy information to infer genre degrees subsequently used for recommendations. The proposed method has the twin advantages of utilizing enriched content information for recommendation as well as squeezing the information from the user-item-tag and user-item ratings spaces and condensing them into fuzzy user profiles. The fuzzy user and object representations are leveraged both for the design of content-based as well as collaborative recommender systems. Experimental evaluations establish the effectiveness of the proposed approaches as compared to other baselines. © 2013 Elsevier Ltd. All rights reserved.

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