Manoj Kumar Mishra

Atmospheric Boundary Layer Characterization Using Multiyear Ground-Based Microwave Radiometric Observations Over a Tropical Coastal Station

The continuous ground-based microwave radiometer profiler (MRP) observations of lower atmospheric temperature and humidity profiles are used to investigate the diurnal evolution of atmospheric boundary layer height (BLH) over a tropical coastal station. The BLH estimated from the MRP observations is compared with concurrent and collocated measurements of mixing layer height using a Micropulse Lidar and the BLH derived from radiosonde ascends. The monthly mean diurnal variation of the BLH derived from the multiyear (2010–2013) MRP observations exhibits strong diurnal variation with the highest around the local afternoon (~12:00–15:00 IST) and the lowest during the nighttime (~100–200 m). The daytime convective BLH is maximum during the premonsoon season (March–May) with the peak value (~1300 m) occurring in April and minimum in the month of July (~600 m). This paper presents the potential of MRP observations to investigate the continuous diurnal evolution of the BLH over a tropical coastal region manifested by a thermal internal boundary layer (TIBL) at much better time resolution, which is essential for understanding the rapid growth of the boundary layer and the TIBL during the forenoon period.

Genetic Diversity Among Ethiopian Coffee (Coffea Arabica L.) Collections Available In Indian Gene Bank Using Sequence Related Amplified Polymorphism Markers

Abstract The South-Western highlands of Ethiopia are considered to be the centre of origin and diversity of the arabica coffee, Coffea arabica. More than 80 accessions of arabica coffee collected from Ethiopia are available in Indian gene bank. However, the genetic diversity of these accessions is not studied in detail. In the present study, genetic diversity analysis of 48 accessions collected from eight provinces of Ethiopia was carried out using Sequence-related amplified Polymorphism (SRAP) marker. Among the thirty two SRAP primer combinations tested, 14 primer pairs were polymorphic and generated 203 distinct fragments. The number of fragments ranged from 7 to 21 with a mean of 14.5 fragments per primer combination. Of the total 203 amplified fragments, 182 (89.65%) were polymorphic and the percent of polymorphism ranged from 53.84% to a maximum of 100% using different primers. The average resolving power (Rp) and average polymorphism information content (PIC) of the 14 SRAP primer combinations was 14.31 and 0.648 respectively. A total of 13 rare alleles were obtained from SRAP assays, of which six rare alleles were obtained from the accessions collected from Shoa province. The UPGMA clustering algorithm from SRAP analysis grouped the 48 coffee accessions into two major clusters. The accessions collected from particular province clustered together which could be attributed to the substantial gene flow between adjacent population and the influence of geographical origin on genetic diversity. The study demonstrated the existence of substantial genetic variation in Ethiopian germplasm which could be utilized in coffee germplasm conservation and improvement program.

An ANN based Two Pass-Two Phase Adaptive Filtering of a Digital Image Corrupted by SPN

Images get contaminated due to different noises at various stages of processing and Salt and Pepper is one such noise. The noise removal approach used for filtering mainly differs in their basic methodologies, but the purpose is to suppress different types and percentage of noise. Some of the filtering schemes replace those corrupted pixels by indentifying the positions of the corrupted pixels in the observed noisy image, with the help of a noise detector, whereas others remove all the pixels irrespective of corruption. This paper investigates the former method in denoising a digital image through incorporation of an adaptive threshold into the noise detection process. The adaptive threshold value thus obtained is based on the noisy image characteristics and their statistics using LeNN (Legendre Neural Network) and the patterns of input image are taken to train FLANN (Functional Link Artificial Neural Network) corrupted by SPN(Salt & Pepper noise). Comparative analysis on standard images at different noise percentage shows that the proposed scheme outperforms the existing schemes in terms of PSNR (peak signal to noise ratio). Thus, the proposed method named as “Two passTwo phase adaptive filtering mechanism” is feasible and also makes it an efficient filter to restore the gray image fairly well preserving the quality of the filtered image, and also provides a better visual perception. General Terms Neural network, Image, Noise

Geomagnetic Storms Associated with Higher Peak Value of IMFBz And Their Relation with Coronal Mass Ejections And Solar Wind Parameters

An investigation of geomagnetic storms associated interplanetary magnetic field of higher peak values with observed between 1997 and 2010 with coronal mass ejections (CMEs) X-ray solar flares and solar wind plasma parameters was carried out. We found that majority 31(67.39%) of the geomagnetic storms are intense. Further it is found that 79.54% geomagnetic storms are associated with halo and partial halo coronal mass ejections. The association rates of halo and partial halo coronal mass ejections were found to be 85.71 and 14.28% respectively. It is also inferred that most of geomagnetic storms (79.82%) are associated with X-ray solar flares of different categories. The association rates of class X, class M, class C and class B X-ray solar flares are 13.33, 40.00, 28.88 and 20.00% respectively. Furthermore, it is concluded that these geomagnetic storms are closely related to disturbances in solar wind plasma parameters. Positive correlation with correlation coefficient 0.81and 0.79 has been found between magnitude of geomagnetic storms and maximum (peak) value and jump magnitude of average interplanetary magnetic field. The correlation coefficient of 0.83 and 0.60 between magnitude of geomagnetic storms and peak value and jump magnitude of associated jump in interplanetary magnetic field (JIMFBz ) events has been obtained. Positive correlation with correlation coefficient 0.56 and0.50 is also found between magnitude of geomagnetic storms and peak value and jump solar wind plasma velocity. The correlation coefficient of 0.45 and 0.36 between magnitude of geomagnetic storms and peak value and jump magnitude of solar wind plasma pressure is also obtained.

E-CAP: An Extended Capability Based Mechanism to Limit Distributed Denial of Service Attacks

Traffic Validation Architecture (TVA) is a capability based network architecture that tries to limit Distributed Denial of Service Attacks (DDoS). It considers only the victimpsilas approval in the capability granting process. We propose an extension to the approach by involving two new parameters, the bottleneck linkpsilas status and message type, in the capability granting mechanism. Both these parameters are considered at the router after the destination has granted capability to send, to the source. Source is allowed to send the data only if the reply to its request containing capability information is bypassed by the router. The inclusion of parameters at the router helps in removing congestion at the bottleneck link and reduces the effect of colluders. The proposed mechanism utilizes the TVA Architecture